+/*#define CHASE_CHAIN*/
/*
* Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
* The Regents of the University of California. All rights reserved.
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
-static const char rcsid[] =
- "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.94.1.1 1999-10-07 23:46:40 mcr Exp $ (LBL)";
+static const char rcsid[] _U_ =
+ "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.290.2.19 2008-12-23 20:14:12 guy Exp $ (LBL)";
#endif
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef WIN32
+#include <pcap-stdinc.h>
+#else /* WIN32 */
#include <sys/types.h>
#include <sys/socket.h>
-#include <sys/time.h>
+#endif /* WIN32 */
-#if __STDC__
-struct mbuf;
-struct rtentry;
+/*
+ * XXX - why was this included even on UNIX?
+ */
+#ifdef __MINGW32__
+#include "IP6_misc.h"
#endif
-#include <net/if.h>
+#ifndef WIN32
+
+#ifdef __NetBSD__
+#include <sys/param.h>
+#endif
#include <netinet/in.h>
-#include <netinet/if_ether.h>
+
+#endif /* WIN32 */
#include <stdlib.h>
+#include <string.h>
#include <memory.h>
#include <setjmp.h>
-#if __STDC__
#include <stdarg.h>
-#else
-#include <varargs.h>
+
+#ifdef MSDOS
+#include "pcap-dos.h"
#endif
#include "pcap-int.h"
#include "ethertype.h"
+#include "nlpid.h"
+#include "llc.h"
#include "gencode.h"
+#include "ieee80211.h"
+#include "atmuni31.h"
+#include "sunatmpos.h"
#include "ppp.h"
-#include <pcap-namedb.h>
+#include "pcap/sll.h"
+#include "arcnet.h"
+#ifdef HAVE_NET_PFVAR_H
+#include <sys/socket.h>
+#include <net/if.h>
+#include <net/pfvar.h>
+#include <net/if_pflog.h>
+#endif
+#ifndef offsetof
+#define offsetof(s, e) ((size_t)&((s *)0)->e)
+#endif
+#ifdef INET6
+#ifndef WIN32
+#include <netdb.h> /* for "struct addrinfo" */
+#endif /* WIN32 */
+#endif /*INET6*/
+#include <pcap/namedb.h>
+
+#define ETHERMTU 1500
+
+#ifndef IPPROTO_SCTP
+#define IPPROTO_SCTP 132
+#endif
-#include "gnuc.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
static jmp_buf top_ctx;
static pcap_t *bpf_pcap;
+/* Hack for updating VLAN, MPLS, and PPPoE offsets. */
+#ifdef WIN32
+static u_int orig_linktype = (u_int)-1, orig_nl = (u_int)-1, label_stack_depth = (u_int)-1;
+#else
+static u_int orig_linktype = -1U, orig_nl = -1U, label_stack_depth = -1U;
+#endif
+
/* XXX */
#ifdef PCAP_FDDIPAD
-int pcap_fddipad = PCAP_FDDIPAD;
-#else
-int pcap_fddipad;
+static int pcap_fddipad;
#endif
/* VARARGS */
-__dead void
-#if __STDC__
+void
bpf_error(const char *fmt, ...)
-#else
-bpf_error(fmt, va_alist)
- const char *fmt;
- va_dcl
-#endif
{
va_list ap;
-#if __STDC__
va_start(ap, fmt);
-#else
- va_start(ap);
-#endif
if (bpf_pcap != NULL)
- (void)vsprintf(pcap_geterr(bpf_pcap), fmt, ap);
+ (void)vsnprintf(pcap_geterr(bpf_pcap), PCAP_ERRBUF_SIZE,
+ fmt, ap);
va_end(ap);
longjmp(top_ctx, 1);
/* NOTREACHED */
}
-static void init_linktype(int);
+static void init_linktype(pcap_t *);
+static void init_regs(void);
static int alloc_reg(void);
static void free_reg(int);
static struct block *root;
+/*
+ * Value passed to gen_load_a() to indicate what the offset argument
+ * is relative to.
+ */
+enum e_offrel {
+ OR_PACKET, /* relative to the beginning of the packet */
+ OR_LINK, /* relative to the beginning of the link-layer header */
+ OR_MACPL, /* relative to the end of the MAC-layer header */
+ OR_NET, /* relative to the network-layer header */
+ OR_NET_NOSNAP, /* relative to the network-layer header, with no SNAP header at the link layer */
+ OR_TRAN_IPV4, /* relative to the transport-layer header, with IPv4 network layer */
+ OR_TRAN_IPV6 /* relative to the transport-layer header, with IPv6 network layer */
+};
+
/*
* We divy out chunks of memory rather than call malloc each time so
* we don't have to worry about leaking memory. It's probably
- * not a big deal if all this memory was wasted but it this ever
+ * not a big deal if all this memory was wasted but if this ever
* goes into a library that would probably not be a good idea.
+ *
+ * XXX - this *is* in a library....
*/
#define NCHUNKS 16
#define CHUNK0SIZE 1024
static void backpatch(struct block *, struct block *);
static void merge(struct block *, struct block *);
-static struct block *gen_cmp(u_int, u_int, bpf_int32);
-static struct block *gen_mcmp(u_int, u_int, bpf_int32, bpf_u_int32);
-static struct block *gen_bcmp(u_int, u_int, const u_char *);
+static struct block *gen_cmp(enum e_offrel, u_int, u_int, bpf_int32);
+static struct block *gen_cmp_gt(enum e_offrel, u_int, u_int, bpf_int32);
+static struct block *gen_cmp_ge(enum e_offrel, u_int, u_int, bpf_int32);
+static struct block *gen_cmp_lt(enum e_offrel, u_int, u_int, bpf_int32);
+static struct block *gen_cmp_le(enum e_offrel, u_int, u_int, bpf_int32);
+static struct block *gen_mcmp(enum e_offrel, u_int, u_int, bpf_int32,
+ bpf_u_int32);
+static struct block *gen_bcmp(enum e_offrel, u_int, u_int, const u_char *);
+static struct block *gen_ncmp(enum e_offrel, bpf_u_int32, bpf_u_int32,
+ bpf_u_int32, bpf_u_int32, int, bpf_int32);
+static struct slist *gen_load_llrel(u_int, u_int);
+static struct slist *gen_load_macplrel(u_int, u_int);
+static struct slist *gen_load_a(enum e_offrel, u_int, u_int);
+static struct slist *gen_loadx_iphdrlen(void);
static struct block *gen_uncond(int);
static inline struct block *gen_true(void);
static inline struct block *gen_false(void);
+static struct block *gen_ether_linktype(int);
+static struct block *gen_linux_sll_linktype(int);
+static struct slist *gen_load_prism_llprefixlen(void);
+static struct slist *gen_load_avs_llprefixlen(void);
+static struct slist *gen_load_radiotap_llprefixlen(void);
+static struct slist *gen_load_ppi_llprefixlen(void);
+static void insert_compute_vloffsets(struct block *);
+static struct slist *gen_llprefixlen(void);
+static struct slist *gen_off_macpl(void);
+static int ethertype_to_ppptype(int);
static struct block *gen_linktype(int);
+static struct block *gen_snap(bpf_u_int32, bpf_u_int32);
+static struct block *gen_llc_linktype(int);
static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int);
+#ifdef INET6
+static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int);
+#endif
+static struct block *gen_ahostop(const u_char *, int);
static struct block *gen_ehostop(const u_char *, int);
static struct block *gen_fhostop(const u_char *, int);
-static struct block *gen_dnhostop(bpf_u_int32, int, u_int);
-static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int);
+static struct block *gen_thostop(const u_char *, int);
+static struct block *gen_wlanhostop(const u_char *, int);
+static struct block *gen_ipfchostop(const u_char *, int);
+static struct block *gen_dnhostop(bpf_u_int32, int);
+static struct block *gen_mpls_linktype(int);
+static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int, int);
+#ifdef INET6
+static struct block *gen_host6(struct in6_addr *, struct in6_addr *, int, int, int);
+#endif
+#ifndef INET6
static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int);
+#endif
static struct block *gen_ipfrag(void);
static struct block *gen_portatom(int, bpf_int32);
+static struct block *gen_portrangeatom(int, bpf_int32, bpf_int32);
+#ifdef INET6
+static struct block *gen_portatom6(int, bpf_int32);
+static struct block *gen_portrangeatom6(int, bpf_int32, bpf_int32);
+#endif
struct block *gen_portop(int, int, int);
static struct block *gen_port(int, int, int);
+struct block *gen_portrangeop(int, int, int, int);
+static struct block *gen_portrange(int, int, int, int);
+#ifdef INET6
+struct block *gen_portop6(int, int, int);
+static struct block *gen_port6(int, int, int);
+struct block *gen_portrangeop6(int, int, int, int);
+static struct block *gen_portrange6(int, int, int, int);
+#endif
static int lookup_proto(const char *, int);
+static struct block *gen_protochain(int, int, int);
static struct block *gen_proto(int, int, int);
static struct slist *xfer_to_x(struct arth *);
static struct slist *xfer_to_a(struct arth *);
+static struct block *gen_mac_multicast(int);
static struct block *gen_len(int, int);
+static struct block *gen_check_802_11_data_frame(void);
+
+static struct block *gen_ppi_dlt_check(void);
+static struct block *gen_msg_abbrev(int type);
static void *
newchunk(n)
u_int n;
{
struct chunk *cp;
- int k, size;
+ int k;
+ size_t size;
+#ifndef __NetBSD__
/* XXX Round up to nearest long. */
n = (n + sizeof(long) - 1) & ~(sizeof(long) - 1);
+#else
+ /* XXX Round up to structure boundary. */
+ n = ALIGN(n);
+#endif
cp = &chunks[cur_chunk];
if (n > cp->n_left) {
bpf_error("out of memory");
size = CHUNK0SIZE << k;
cp->m = (void *)malloc(size);
+ if (cp->m == NULL)
+ bpf_error("out of memory");
memset((char *)cp->m, 0, size);
cp->n_left = size;
if (n > size)
int n = strlen(s) + 1;
char *cp = newchunk(n);
- strcpy(cp, s);
+ strlcpy(cp, s, n);
return (cp);
}
static bpf_u_int32 netmask;
static int snaplen;
+int no_optimize;
int
pcap_compile(pcap_t *p, struct bpf_program *program,
- char *buf, int optimize, bpf_u_int32 mask)
+ const char *buf, int optimize, bpf_u_int32 mask)
{
extern int n_errors;
+ const char * volatile xbuf = buf;
int len;
+ no_optimize = 0;
n_errors = 0;
root = NULL;
bpf_pcap = p;
+ init_regs();
if (setjmp(top_ctx)) {
+ lex_cleanup();
freechunks();
return (-1);
}
netmask = mask;
+
snaplen = pcap_snapshot(p);
+ if (snaplen == 0) {
+ snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
+ "snaplen of 0 rejects all packets");
+ return -1;
+ }
- lex_init(buf ? buf : "");
- init_linktype(pcap_datalink(p));
+ lex_init(xbuf ? xbuf : "");
+ init_linktype(p);
(void)pcap_parse();
if (n_errors)
if (root == NULL)
root = gen_retblk(snaplen);
- if (optimize) {
+ if (optimize && !no_optimize) {
bpf_optimize(&root);
if (root == NULL ||
(root->s.code == (BPF_RET|BPF_K) && root->s.k == 0))
program->bf_insns = icode_to_fcode(root, &len);
program->bf_len = len;
+ lex_cleanup();
freechunks();
return (0);
}
+/*
+ * entry point for using the compiler with no pcap open
+ * pass in all the stuff that is needed explicitly instead.
+ */
+int
+pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
+ struct bpf_program *program,
+ const char *buf, int optimize, bpf_u_int32 mask)
+{
+ pcap_t *p;
+ int ret;
+
+ p = pcap_open_dead(linktype_arg, snaplen_arg);
+ if (p == NULL)
+ return (-1);
+ ret = pcap_compile(p, program, buf, optimize, mask);
+ pcap_close(p);
+ return (ret);
+}
+
+/*
+ * Clean up a "struct bpf_program" by freeing all the memory allocated
+ * in it.
+ */
+void
+pcap_freecode(struct bpf_program *program)
+{
+ program->bf_len = 0;
+ if (program->bf_insns != NULL) {
+ free((char *)program->bf_insns);
+ program->bf_insns = NULL;
+ }
+}
+
/*
* Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates
* which of the jt and jf fields has been resolved and which is a pointer
finish_parse(p)
struct block *p;
{
+ struct block *ppi_dlt_check;
+
+ /*
+ * Insert before the statements of the first (root) block any
+ * statements needed to load the lengths of any variable-length
+ * headers into registers.
+ *
+ * XXX - a fancier strategy would be to insert those before the
+ * statements of all blocks that use those lengths and that
+ * have no predecessors that use them, so that we only compute
+ * the lengths if we need them. There might be even better
+ * approaches than that.
+ *
+ * However, those strategies would be more complicated, and
+ * as we don't generate code to compute a length if the
+ * program has no tests that use the length, and as most
+ * tests will probably use those lengths, we would just
+ * postpone computing the lengths so that it's not done
+ * for tests that fail early, and it's not clear that's
+ * worth the effort.
+ */
+ insert_compute_vloffsets(p->head);
+
+ /*
+ * For DLT_PPI captures, generate a check of the per-packet
+ * DLT value to make sure it's DLT_IEEE802_11.
+ */
+ ppi_dlt_check = gen_ppi_dlt_check();
+ if (ppi_dlt_check != NULL)
+ gen_and(ppi_dlt_check, p);
+
backpatch(p, gen_retblk(snaplen));
p->sense = !p->sense;
backpatch(p, gen_retblk(0));
}
static struct block *
-gen_cmp(offset, size, v)
+gen_cmp(offrel, offset, size, v)
+ enum e_offrel offrel;
u_int offset, size;
bpf_int32 v;
{
- struct slist *s;
- struct block *b;
+ return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JEQ, 0, v);
+}
- s = new_stmt(BPF_LD|BPF_ABS|size);
- s->s.k = offset;
+static struct block *
+gen_cmp_gt(offrel, offset, size, v)
+ enum e_offrel offrel;
+ u_int offset, size;
+ bpf_int32 v;
+{
+ return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGT, 0, v);
+}
- b = new_block(JMP(BPF_JEQ));
- b->stmts = s;
- b->s.k = v;
+static struct block *
+gen_cmp_ge(offrel, offset, size, v)
+ enum e_offrel offrel;
+ u_int offset, size;
+ bpf_int32 v;
+{
+ return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGE, 0, v);
+}
- return b;
+static struct block *
+gen_cmp_lt(offrel, offset, size, v)
+ enum e_offrel offrel;
+ u_int offset, size;
+ bpf_int32 v;
+{
+ return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGE, 1, v);
}
static struct block *
-gen_mcmp(offset, size, v, mask)
+gen_cmp_le(offrel, offset, size, v)
+ enum e_offrel offrel;
u_int offset, size;
bpf_int32 v;
- bpf_u_int32 mask;
{
- struct block *b = gen_cmp(offset, size, v);
- struct slist *s;
+ return gen_ncmp(offrel, offset, size, 0xffffffff, BPF_JGT, 1, v);
+}
- if (mask != 0xffffffff) {
- s = new_stmt(BPF_ALU|BPF_AND|BPF_K);
- s->s.k = mask;
- b->stmts->next = s;
- }
- return b;
+static struct block *
+gen_mcmp(offrel, offset, size, v, mask)
+ enum e_offrel offrel;
+ u_int offset, size;
+ bpf_int32 v;
+ bpf_u_int32 mask;
+{
+ return gen_ncmp(offrel, offset, size, mask, BPF_JEQ, 0, v);
}
static struct block *
-gen_bcmp(offset, size, v)
+gen_bcmp(offrel, offset, size, v)
+ enum e_offrel offrel;
register u_int offset, size;
register const u_char *v;
{
bpf_int32 w = ((bpf_int32)p[0] << 24) |
((bpf_int32)p[1] << 16) | ((bpf_int32)p[2] << 8) | p[3];
- tmp = gen_cmp(offset + size - 4, BPF_W, w);
+ tmp = gen_cmp(offrel, offset + size - 4, BPF_W, w);
if (b != NULL)
gen_and(b, tmp);
b = tmp;
register const u_char *p = &v[size - 2];
bpf_int32 w = ((bpf_int32)p[0] << 8) | p[1];
- tmp = gen_cmp(offset + size - 2, BPF_H, w);
+ tmp = gen_cmp(offrel, offset + size - 2, BPF_H, w);
if (b != NULL)
gen_and(b, tmp);
b = tmp;
size -= 2;
}
if (size > 0) {
- tmp = gen_cmp(offset, BPF_B, (bpf_int32)v[0]);
+ tmp = gen_cmp(offrel, offset, BPF_B, (bpf_int32)v[0]);
if (b != NULL)
gen_and(b, tmp);
b = tmp;
return b;
}
+/*
+ * AND the field of size "size" at offset "offset" relative to the header
+ * specified by "offrel" with "mask", and compare it with the value "v"
+ * with the test specified by "jtype"; if "reverse" is true, the test
+ * should test the opposite of "jtype".
+ */
+static struct block *
+gen_ncmp(offrel, offset, size, mask, jtype, reverse, v)
+ enum e_offrel offrel;
+ bpf_int32 v;
+ bpf_u_int32 offset, size, mask, jtype;
+ int reverse;
+{
+ struct slist *s, *s2;
+ struct block *b;
+
+ s = gen_load_a(offrel, offset, size);
+
+ if (mask != 0xffffffff) {
+ s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K);
+ s2->s.k = mask;
+ sappend(s, s2);
+ }
+
+ b = new_block(JMP(jtype));
+ b->stmts = s;
+ b->s.k = v;
+ if (reverse && (jtype == BPF_JGT || jtype == BPF_JGE))
+ gen_not(b);
+ return b;
+}
+
/*
* Various code constructs need to know the layout of the data link
- * layer. These variables give the necessary offsets. off_linktype
- * is set to -1 for no encapsulation, in which case, IP is assumed.
+ * layer. These variables give the necessary offsets from the beginning
+ * of the packet data.
+ */
+
+/*
+ * This is the offset of the beginning of the link-layer header from
+ * the beginning of the raw packet data.
+ *
+ * It's usually 0, except for 802.11 with a fixed-length radio header.
+ * (For 802.11 with a variable-length radio header, we have to generate
+ * code to compute that offset; off_ll is 0 in that case.)
+ */
+static u_int off_ll;
+
+/*
+ * If there's a variable-length header preceding the link-layer header,
+ * "reg_off_ll" is the register number for a register containing the
+ * length of that header, and therefore the offset of the link-layer
+ * header from the beginning of the raw packet data. Otherwise,
+ * "reg_off_ll" is -1.
+ */
+static int reg_off_ll;
+
+/*
+ * This is the offset of the beginning of the MAC-layer header from
+ * the beginning of the link-layer header.
+ * It's usually 0, except for ATM LANE, where it's the offset, relative
+ * to the beginning of the raw packet data, of the Ethernet header.
+ */
+static u_int off_mac;
+
+/*
+ * This is the offset of the beginning of the MAC-layer payload,
+ * from the beginning of the raw packet data.
+ *
+ * I.e., it's the sum of the length of the link-layer header (without,
+ * for example, any 802.2 LLC header, so it's the MAC-layer
+ * portion of that header), plus any prefix preceding the
+ * link-layer header.
+ */
+static u_int off_macpl;
+
+/*
+ * This is 1 if the offset of the beginning of the MAC-layer payload
+ * from the beginning of the link-layer header is variable-length.
+ */
+static int off_macpl_is_variable;
+
+/*
+ * If the link layer has variable_length headers, "reg_off_macpl"
+ * is the register number for a register containing the length of the
+ * link-layer header plus the length of any variable-length header
+ * preceding the link-layer header. Otherwise, "reg_off_macpl"
+ * is -1.
+ */
+static int reg_off_macpl;
+
+/*
+ * "off_linktype" is the offset to information in the link-layer header
+ * giving the packet type. This offset is relative to the beginning
+ * of the link-layer header (i.e., it doesn't include off_ll).
+ *
+ * For Ethernet, it's the offset of the Ethernet type field.
+ *
+ * For link-layer types that always use 802.2 headers, it's the
+ * offset of the LLC header.
+ *
+ * For PPP, it's the offset of the PPP type field.
+ *
+ * For Cisco HDLC, it's the offset of the CHDLC type field.
+ *
+ * For BSD loopback, it's the offset of the AF_ value.
+ *
+ * For Linux cooked sockets, it's the offset of the type field.
+ *
+ * It's set to -1 for no encapsulation, in which case, IP is assumed.
*/
static u_int off_linktype;
+
+/*
+ * TRUE if "pppoes" appeared in the filter; it causes link-layer type
+ * checks to check the PPP header, assumed to follow a LAN-style link-
+ * layer header and a PPPoE session header.
+ */
+static int is_pppoes = 0;
+
+/*
+ * TRUE if the link layer includes an ATM pseudo-header.
+ */
+static int is_atm = 0;
+
+/*
+ * TRUE if "lane" appeared in the filter; it causes us to generate
+ * code that assumes LANE rather than LLC-encapsulated traffic in SunATM.
+ */
+static int is_lane = 0;
+
+/*
+ * These are offsets for the ATM pseudo-header.
+ */
+static u_int off_vpi;
+static u_int off_vci;
+static u_int off_proto;
+
+/*
+ * These are offsets for the MTP2 fields.
+ */
+static u_int off_li;
+
+/*
+ * These are offsets for the MTP3 fields.
+ */
+static u_int off_sio;
+static u_int off_opc;
+static u_int off_dpc;
+static u_int off_sls;
+
+/*
+ * This is the offset of the first byte after the ATM pseudo_header,
+ * or -1 if there is no ATM pseudo-header.
+ */
+static u_int off_payload;
+
+/*
+ * These are offsets to the beginning of the network-layer header.
+ * They are relative to the beginning of the MAC-layer payload (i.e.,
+ * they don't include off_ll or off_macpl).
+ *
+ * If the link layer never uses 802.2 LLC:
+ *
+ * "off_nl" and "off_nl_nosnap" are the same.
+ *
+ * If the link layer always uses 802.2 LLC:
+ *
+ * "off_nl" is the offset if there's a SNAP header following
+ * the 802.2 header;
+ *
+ * "off_nl_nosnap" is the offset if there's no SNAP header.
+ *
+ * If the link layer is Ethernet:
+ *
+ * "off_nl" is the offset if the packet is an Ethernet II packet
+ * (we assume no 802.3+802.2+SNAP);
+ *
+ * "off_nl_nosnap" is the offset if the packet is an 802.3 packet
+ * with an 802.2 header following it.
+ */
static u_int off_nl;
+static u_int off_nl_nosnap;
+
static int linktype;
static void
-init_linktype(type)
- int type;
+init_linktype(p)
+ pcap_t *p;
{
- linktype = type;
+ linktype = pcap_datalink(p);
+#ifdef PCAP_FDDIPAD
+ pcap_fddipad = p->fddipad;
+#endif
- switch (type) {
+ /*
+ * Assume it's not raw ATM with a pseudo-header, for now.
+ */
+ off_mac = 0;
+ is_atm = 0;
+ is_lane = 0;
+ off_vpi = -1;
+ off_vci = -1;
+ off_proto = -1;
+ off_payload = -1;
+
+ /*
+ * And that we're not doing PPPoE.
+ */
+ is_pppoes = 0;
+
+ /*
+ * And assume we're not doing SS7.
+ */
+ off_li = -1;
+ off_sio = -1;
+ off_opc = -1;
+ off_dpc = -1;
+ off_sls = -1;
+
+ /*
+ * Also assume it's not 802.11.
+ */
+ off_ll = 0;
+ off_macpl = 0;
+ off_macpl_is_variable = 0;
+
+ orig_linktype = -1;
+ orig_nl = -1;
+ label_stack_depth = 0;
+
+ reg_off_ll = -1;
+ reg_off_macpl = -1;
+
+ switch (linktype) {
+
+ case DLT_ARCNET:
+ off_linktype = 2;
+ off_macpl = 6;
+ off_nl = 0; /* XXX in reality, variable! */
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
+
+ case DLT_ARCNET_LINUX:
+ off_linktype = 4;
+ off_macpl = 8;
+ off_nl = 0; /* XXX in reality, variable! */
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
case DLT_EN10MB:
off_linktype = 12;
- off_nl = 14;
+ off_macpl = 14; /* Ethernet header length */
+ off_nl = 0; /* Ethernet II */
+ off_nl_nosnap = 3; /* 802.3+802.2 */
return;
case DLT_SLIP:
* header is hacked into our SLIP driver.
*/
off_linktype = -1;
- off_nl = 16;
+ off_macpl = 16;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
return;
case DLT_SLIP_BSDOS:
/* XXX this may be the same as the DLT_PPP_BSDOS case */
off_linktype = -1;
/* XXX end */
- off_nl = 24;
+ off_macpl = 24;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
return;
case DLT_NULL:
+ case DLT_LOOP:
off_linktype = 0;
- off_nl = 4;
+ off_macpl = 4;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
+
+ case DLT_ENC:
+ off_linktype = 0;
+ off_macpl = 12;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
return;
case DLT_PPP:
+ case DLT_PPP_PPPD:
+ case DLT_C_HDLC: /* BSD/OS Cisco HDLC */
+ case DLT_PPP_SERIAL: /* NetBSD sync/async serial PPP */
off_linktype = 2;
- off_nl = 4;
+ off_macpl = 4;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
+
+ case DLT_PPP_ETHER:
+ /*
+ * This does no include the Ethernet header, and
+ * only covers session state.
+ */
+ off_linktype = 6;
+ off_macpl = 8;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
return;
case DLT_PPP_BSDOS:
off_linktype = 5;
- off_nl = 24;
+ off_macpl = 24;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
return;
case DLT_FDDI:
/*
* FDDI doesn't really have a link-level type field.
- * We assume that SSAP = SNAP is being used and pick
- * out the encapsulated Ethernet type.
+ * We set "off_linktype" to the offset of the LLC header.
+ *
+ * To check for Ethernet types, we assume that SSAP = SNAP
+ * is being used and pick out the encapsulated Ethernet type.
+ * XXX - should we generate code to check for SNAP?
*/
- off_linktype = 19;
+ off_linktype = 13;
#ifdef PCAP_FDDIPAD
off_linktype += pcap_fddipad;
#endif
- off_nl = 21;
+ off_macpl = 13; /* FDDI MAC header length */
#ifdef PCAP_FDDIPAD
- off_nl += pcap_fddipad;
+ off_macpl += pcap_fddipad;
#endif
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
return;
case DLT_IEEE802:
- off_linktype = 20;
- off_nl = 22;
+ /*
+ * Token Ring doesn't really have a link-level type field.
+ * We set "off_linktype" to the offset of the LLC header.
+ *
+ * To check for Ethernet types, we assume that SSAP = SNAP
+ * is being used and pick out the encapsulated Ethernet type.
+ * XXX - should we generate code to check for SNAP?
+ *
+ * XXX - the header is actually variable-length.
+ * Some various Linux patched versions gave 38
+ * as "off_linktype" and 40 as "off_nl"; however,
+ * if a token ring packet has *no* routing
+ * information, i.e. is not source-routed, the correct
+ * values are 20 and 22, as they are in the vanilla code.
+ *
+ * A packet is source-routed iff the uppermost bit
+ * of the first byte of the source address, at an
+ * offset of 8, has the uppermost bit set. If the
+ * packet is source-routed, the total number of bytes
+ * of routing information is 2 plus bits 0x1F00 of
+ * the 16-bit value at an offset of 14 (shifted right
+ * 8 - figure out which byte that is).
+ */
+ off_linktype = 14;
+ off_macpl = 14; /* Token Ring MAC header length */
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ return;
+
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ /*
+ * 802.11 doesn't really have a link-level type field.
+ * We set "off_linktype" to the offset of the LLC header.
+ *
+ * To check for Ethernet types, we assume that SSAP = SNAP
+ * is being used and pick out the encapsulated Ethernet type.
+ * XXX - should we generate code to check for SNAP?
+ *
+ * We also handle variable-length radio headers here.
+ * The Prism header is in theory variable-length, but in
+ * practice it's always 144 bytes long. However, some
+ * drivers on Linux use ARPHRD_IEEE80211_PRISM, but
+ * sometimes or always supply an AVS header, so we
+ * have to check whether the radio header is a Prism
+ * header or an AVS header, so, in practice, it's
+ * variable-length.
+ */
+ off_linktype = 24;
+ off_macpl = 0; /* link-layer header is variable-length */
+ off_macpl_is_variable = 1;
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ return;
+
+ case DLT_PPI:
+ /*
+ * At the moment we treat PPI the same way that we treat
+ * normal Radiotap encoded packets. The difference is in
+ * the function that generates the code at the beginning
+ * to compute the header length. Since this code generator
+ * of PPI supports bare 802.11 encapsulation only (i.e.
+ * the encapsulated DLT should be DLT_IEEE802_11) we
+ * generate code to check for this too.
+ */
+ off_linktype = 24;
+ off_macpl = 0; /* link-layer header is variable-length */
+ off_macpl_is_variable = 1;
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
return;
case DLT_ATM_RFC1483:
+ case DLT_ATM_CLIP: /* Linux ATM defines this */
/*
* assume routed, non-ISO PDUs
* (i.e., LLC = 0xAA-AA-03, OUT = 0x00-00-00)
+ *
+ * XXX - what about ISO PDUs, e.g. CLNP, ISIS, ESIS,
+ * or PPP with the PPP NLPID (e.g., PPPoA)? The
+ * latter would presumably be treated the way PPPoE
+ * should be, so you can do "pppoe and udp port 2049"
+ * or "pppoa and tcp port 80" and have it check for
+ * PPPo{A,E} and a PPP protocol of IP and....
*/
- off_linktype = 6;
- off_nl = 8;
+ off_linktype = 0;
+ off_macpl = 0; /* packet begins with LLC header */
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ return;
+
+ case DLT_SUNATM:
+ /*
+ * Full Frontal ATM; you get AALn PDUs with an ATM
+ * pseudo-header.
+ */
+ is_atm = 1;
+ off_vpi = SUNATM_VPI_POS;
+ off_vci = SUNATM_VCI_POS;
+ off_proto = PROTO_POS;
+ off_mac = -1; /* assume LLC-encapsulated, so no MAC-layer header */
+ off_payload = SUNATM_PKT_BEGIN_POS;
+ off_linktype = off_payload;
+ off_macpl = off_payload; /* if LLC-encapsulated */
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
return;
case DLT_RAW:
off_linktype = -1;
+ off_macpl = 0;
off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
return;
- }
- bpf_error("unknown data link type 0x%x", linktype);
- /* NOTREACHED */
-}
-
-static struct block *
-gen_uncond(rsense)
- int rsense;
-{
- struct block *b;
- struct slist *s;
- s = new_stmt(BPF_LD|BPF_IMM);
- s->s.k = !rsense;
- b = new_block(JMP(BPF_JEQ));
- b->stmts = s;
+ case DLT_LINUX_SLL: /* fake header for Linux cooked socket */
+ off_linktype = 14;
+ off_macpl = 16;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
- return b;
-}
+ case DLT_LTALK:
+ /*
+ * LocalTalk does have a 1-byte type field in the LLAP header,
+ * but really it just indicates whether there is a "short" or
+ * "long" DDP packet following.
+ */
+ off_linktype = -1;
+ off_macpl = 0;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
-static inline struct block *
-gen_true()
+ case DLT_IP_OVER_FC:
+ /*
+ * RFC 2625 IP-over-Fibre-Channel doesn't really have a
+ * link-level type field. We set "off_linktype" to the
+ * offset of the LLC header.
+ *
+ * To check for Ethernet types, we assume that SSAP = SNAP
+ * is being used and pick out the encapsulated Ethernet type.
+ * XXX - should we generate code to check for SNAP? RFC
+ * 2625 says SNAP should be used.
+ */
+ off_linktype = 16;
+ off_macpl = 16;
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ return;
+
+ case DLT_FRELAY:
+ /*
+ * XXX - we should set this to handle SNAP-encapsulated
+ * frames (NLPID of 0x80).
+ */
+ off_linktype = -1;
+ off_macpl = 0;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
+
+ /*
+ * the only BPF-interesting FRF.16 frames are non-control frames;
+ * Frame Relay has a variable length link-layer
+ * so lets start with offset 4 for now and increments later on (FIXME);
+ */
+ case DLT_MFR:
+ off_linktype = -1;
+ off_macpl = 0;
+ off_nl = 4;
+ off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */
+ return;
+
+ case DLT_APPLE_IP_OVER_IEEE1394:
+ off_linktype = 16;
+ off_macpl = 18;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
+
+ case DLT_LINUX_IRDA:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_DOCSIS:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_SYMANTEC_FIREWALL:
+ off_linktype = 6;
+ off_macpl = 44;
+ off_nl = 0; /* Ethernet II */
+ off_nl_nosnap = 0; /* XXX - what does it do with 802.3 packets? */
+ return;
+
+#ifdef HAVE_NET_PFVAR_H
+ case DLT_PFLOG:
+ off_linktype = 0;
+ off_macpl = PFLOG_HDRLEN;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ return;
+#endif
+
+ case DLT_JUNIPER_MFR:
+ case DLT_JUNIPER_MLFR:
+ case DLT_JUNIPER_MLPPP:
+ case DLT_JUNIPER_PPP:
+ case DLT_JUNIPER_CHDLC:
+ case DLT_JUNIPER_FRELAY:
+ off_linktype = 4;
+ off_macpl = 4;
+ off_nl = 0;
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ return;
+
+ case DLT_JUNIPER_ATM1:
+ off_linktype = 4; /* in reality variable between 4-8 */
+ off_macpl = 4; /* in reality variable between 4-8 */
+ off_nl = 0;
+ off_nl_nosnap = 10;
+ return;
+
+ case DLT_JUNIPER_ATM2:
+ off_linktype = 8; /* in reality variable between 8-12 */
+ off_macpl = 8; /* in reality variable between 8-12 */
+ off_nl = 0;
+ off_nl_nosnap = 10;
+ return;
+
+ /* frames captured on a Juniper PPPoE service PIC
+ * contain raw ethernet frames */
+ case DLT_JUNIPER_PPPOE:
+ case DLT_JUNIPER_ETHER:
+ off_macpl = 14;
+ off_linktype = 16;
+ off_nl = 18; /* Ethernet II */
+ off_nl_nosnap = 21; /* 802.3+802.2 */
+ return;
+
+ case DLT_JUNIPER_PPPOE_ATM:
+ off_linktype = 4;
+ off_macpl = 6;
+ off_nl = 0;
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ return;
+
+ case DLT_JUNIPER_GGSN:
+ off_linktype = 6;
+ off_macpl = 12;
+ off_nl = 0;
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ return;
+
+ case DLT_JUNIPER_ES:
+ off_linktype = 6;
+ off_macpl = -1; /* not really a network layer but raw IP addresses */
+ off_nl = -1; /* not really a network layer but raw IP addresses */
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ return;
+
+ case DLT_JUNIPER_MONITOR:
+ off_linktype = 12;
+ off_macpl = 12;
+ off_nl = 0; /* raw IP/IP6 header */
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ return;
+
+ case DLT_JUNIPER_SERVICES:
+ off_linktype = 12;
+ off_macpl = -1; /* L3 proto location dep. on cookie type */
+ off_nl = -1; /* L3 proto location dep. on cookie type */
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ return;
+
+ case DLT_JUNIPER_VP:
+ off_linktype = 18;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_JUNIPER_ST:
+ off_linktype = 18;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_JUNIPER_ISM:
+ off_linktype = 8;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_MTP2:
+ off_li = 2;
+ off_sio = 3;
+ off_opc = 4;
+ off_dpc = 4;
+ off_sls = 7;
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_MTP2_WITH_PHDR:
+ off_li = 6;
+ off_sio = 7;
+ off_opc = 8;
+ off_dpc = 8;
+ off_sls = 11;
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_ERF:
+ off_li = 22;
+ off_sio = 23;
+ off_opc = 24;
+ off_dpc = 24;
+ off_sls = 27;
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+#ifdef DLT_PFSYNC
+ case DLT_PFSYNC:
+ off_linktype = -1;
+ off_macpl = 4;
+ off_nl = 0;
+ off_nl_nosnap = 0;
+ return;
+#endif
+
+ case DLT_LINUX_LAPD:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_USB:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_BLUETOOTH_HCI_H4:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_USB_LINUX:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_CAN20B:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_IEEE802_15_4_LINUX:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_IEEE802_16_MAC_CPS_RADIO:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_IEEE802_15_4:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_SITA:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_RAIF1:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_IPMB:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_BLUETOOTH_HCI_H4_WITH_PHDR:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_AX25_KISS:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1; /* variable, min 15, max 71 steps of 7 */
+ off_macpl = -1;
+ off_nl = -1; /* variable, min 16, max 71 steps of 7 */
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ off_mac = 1; /* step over the kiss length byte */
+ return;
+
+ case DLT_IEEE802_15_4_NONASK_PHY:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_MPLS:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+
+ case DLT_USB_LINUX_MMAPPED:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype = -1;
+ off_macpl = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ return;
+ }
+ bpf_error("unknown data link type %d", linktype);
+ /* NOTREACHED */
+}
+
+/*
+ * Load a value relative to the beginning of the link-layer header.
+ * The link-layer header doesn't necessarily begin at the beginning
+ * of the packet data; there might be a variable-length prefix containing
+ * radio information.
+ */
+static struct slist *
+gen_load_llrel(offset, size)
+ u_int offset, size;
{
- return gen_uncond(1);
+ struct slist *s, *s2;
+
+ s = gen_llprefixlen();
+
+ /*
+ * If "s" is non-null, it has code to arrange that the X register
+ * contains the length of the prefix preceding the link-layer
+ * header.
+ *
+ * Otherwise, the length of the prefix preceding the link-layer
+ * header is "off_ll".
+ */
+ if (s != NULL) {
+ /*
+ * There's a variable-length prefix preceding the
+ * link-layer header. "s" points to a list of statements
+ * that put the length of that prefix into the X register.
+ * do an indirect load, to use the X register as an offset.
+ */
+ s2 = new_stmt(BPF_LD|BPF_IND|size);
+ s2->s.k = offset;
+ sappend(s, s2);
+ } else {
+ /*
+ * There is no variable-length header preceding the
+ * link-layer header; add in off_ll, which, if there's
+ * a fixed-length header preceding the link-layer header,
+ * is the length of that header.
+ */
+ s = new_stmt(BPF_LD|BPF_ABS|size);
+ s->s.k = offset + off_ll;
+ }
+ return s;
}
-static inline struct block *
-gen_false()
+/*
+ * Load a value relative to the beginning of the MAC-layer payload.
+ */
+static struct slist *
+gen_load_macplrel(offset, size)
+ u_int offset, size;
{
- return gen_uncond(0);
+ struct slist *s, *s2;
+
+ s = gen_off_macpl();
+
+ /*
+ * If s is non-null, the offset of the MAC-layer payload is
+ * variable, and s points to a list of instructions that
+ * arrange that the X register contains that offset.
+ *
+ * Otherwise, the offset of the MAC-layer payload is constant,
+ * and is in off_macpl.
+ */
+ if (s != NULL) {
+ /*
+ * The offset of the MAC-layer payload is in the X
+ * register. Do an indirect load, to use the X register
+ * as an offset.
+ */
+ s2 = new_stmt(BPF_LD|BPF_IND|size);
+ s2->s.k = offset;
+ sappend(s, s2);
+ } else {
+ /*
+ * The offset of the MAC-layer payload is constant,
+ * and is in off_macpl; load the value at that offset
+ * plus the specified offset.
+ */
+ s = new_stmt(BPF_LD|BPF_ABS|size);
+ s->s.k = off_macpl + offset;
+ }
+ return s;
}
-static struct block *
-gen_linktype(proto)
- register int proto;
+/*
+ * Load a value relative to the beginning of the specified header.
+ */
+static struct slist *
+gen_load_a(offrel, offset, size)
+ enum e_offrel offrel;
+ u_int offset, size;
{
- struct block *b0, *b1;
+ struct slist *s, *s2;
- /* If we're not using encapsulation and checking for IP, we're done */
- if (off_linktype == -1 && proto == ETHERTYPE_IP)
- return gen_true();
+ switch (offrel) {
- switch (linktype) {
+ case OR_PACKET:
+ s = new_stmt(BPF_LD|BPF_ABS|size);
+ s->s.k = offset;
+ break;
- case DLT_SLIP:
- return gen_false();
+ case OR_LINK:
+ s = gen_load_llrel(offset, size);
+ break;
- case DLT_PPP:
- if (proto == ETHERTYPE_IP)
- proto = PPP_IP; /* XXX was 0x21 */
+ case OR_MACPL:
+ s = gen_load_macplrel(offset, size);
break;
- case DLT_PPP_BSDOS:
- switch (proto) {
+ case OR_NET:
+ s = gen_load_macplrel(off_nl + offset, size);
+ break;
- case ETHERTYPE_IP:
- b0 = gen_cmp(off_linktype, BPF_H, PPP_IP);
- b1 = gen_cmp(off_linktype, BPF_H, PPP_VJC);
- gen_or(b0, b1);
- b0 = gen_cmp(off_linktype, BPF_H, PPP_VJNC);
- gen_or(b1, b0);
- return b0;
+ case OR_NET_NOSNAP:
+ s = gen_load_macplrel(off_nl_nosnap + offset, size);
+ break;
- case ETHERTYPE_DN:
- proto = PPP_DECNET;
- break;
+ case OR_TRAN_IPV4:
+ /*
+ * Load the X register with the length of the IPv4 header
+ * (plus the offset of the link-layer header, if it's
+ * preceded by a variable-length header such as a radio
+ * header), in bytes.
+ */
+ s = gen_loadx_iphdrlen();
+
+ /*
+ * Load the item at {offset of the MAC-layer payload} +
+ * {offset, relative to the start of the MAC-layer
+ * paylod, of the IPv4 header} + {length of the IPv4 header} +
+ * {specified offset}.
+ *
+ * (If the offset of the MAC-layer payload is variable,
+ * it's included in the value in the X register, and
+ * off_macpl is 0.)
+ */
+ s2 = new_stmt(BPF_LD|BPF_IND|size);
+ s2->s.k = off_macpl + off_nl + offset;
+ sappend(s, s2);
+ break;
+
+ case OR_TRAN_IPV6:
+ s = gen_load_macplrel(off_nl + 40 + offset, size);
+ break;
+
+ default:
+ abort();
+ return NULL;
+ }
+ return s;
+}
+
+/*
+ * Generate code to load into the X register the sum of the length of
+ * the IPv4 header and any variable-length header preceding the link-layer
+ * header.
+ */
+static struct slist *
+gen_loadx_iphdrlen()
+{
+ struct slist *s, *s2;
+
+ s = gen_off_macpl();
+ if (s != NULL) {
+ /*
+ * There's a variable-length prefix preceding the
+ * link-layer header, or the link-layer header is itself
+ * variable-length. "s" points to a list of statements
+ * that put the offset of the MAC-layer payload into
+ * the X register.
+ *
+ * The 4*([k]&0xf) addressing mode can't be used, as we
+ * don't have a constant offset, so we have to load the
+ * value in question into the A register and add to it
+ * the value from the X register.
+ */
+ s2 = new_stmt(BPF_LD|BPF_IND|BPF_B);
+ s2->s.k = off_nl;
+ sappend(s, s2);
+ s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K);
+ s2->s.k = 0xf;
+ sappend(s, s2);
+ s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
+ s2->s.k = 2;
+ sappend(s, s2);
+
+ /*
+ * The A register now contains the length of the
+ * IP header. We need to add to it the offset of
+ * the MAC-layer payload, which is still in the X
+ * register, and move the result into the X register.
+ */
+ sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
+ sappend(s, new_stmt(BPF_MISC|BPF_TAX));
+ } else {
+ /*
+ * There is no variable-length header preceding the
+ * link-layer header, and the link-layer header is
+ * fixed-length; load the length of the IPv4 header,
+ * which is at an offset of off_nl from the beginning
+ * of the MAC-layer payload, and thus at an offset
+ * of off_mac_pl + off_nl from the beginning of the
+ * raw packet data.
+ */
+ s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
+ s->s.k = off_macpl + off_nl;
+ }
+ return s;
+}
+
+static struct block *
+gen_uncond(rsense)
+ int rsense;
+{
+ struct block *b;
+ struct slist *s;
+
+ s = new_stmt(BPF_LD|BPF_IMM);
+ s->s.k = !rsense;
+ b = new_block(JMP(BPF_JEQ));
+ b->stmts = s;
+
+ return b;
+}
+
+static inline struct block *
+gen_true()
+{
+ return gen_uncond(1);
+}
+
+static inline struct block *
+gen_false()
+{
+ return gen_uncond(0);
+}
+
+/*
+ * Byte-swap a 32-bit number.
+ * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
+ * big-endian platforms.)
+ */
+#define SWAPLONG(y) \
+((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
+
+/*
+ * Generate code to match a particular packet type.
+ *
+ * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
+ * value, if <= ETHERMTU. We use that to determine whether to
+ * match the type/length field or to check the type/length field for
+ * a value <= ETHERMTU to see whether it's a type field and then do
+ * the appropriate test.
+ */
+static struct block *
+gen_ether_linktype(proto)
+ register int proto;
+{
+ struct block *b0, *b1;
+
+ switch (proto) {
+
+ case LLCSAP_ISONS:
+ case LLCSAP_IP:
+ case LLCSAP_NETBEUI:
+ /*
+ * OSI protocols and NetBEUI always use 802.2 encapsulation,
+ * so we check the DSAP and SSAP.
+ *
+ * LLCSAP_IP checks for IP-over-802.2, rather
+ * than IP-over-Ethernet or IP-over-SNAP.
+ *
+ * XXX - should we check both the DSAP and the
+ * SSAP, like this, or should we check just the
+ * DSAP, as we do for other types <= ETHERMTU
+ * (i.e., other SAP values)?
+ */
+ b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
+ gen_not(b0);
+ b1 = gen_cmp(OR_MACPL, 0, BPF_H, (bpf_int32)
+ ((proto << 8) | proto));
+ gen_and(b0, b1);
+ return b1;
+
+ case LLCSAP_IPX:
+ /*
+ * Check for;
+ *
+ * Ethernet_II frames, which are Ethernet
+ * frames with a frame type of ETHERTYPE_IPX;
+ *
+ * Ethernet_802.3 frames, which are 802.3
+ * frames (i.e., the type/length field is
+ * a length field, <= ETHERMTU, rather than
+ * a type field) with the first two bytes
+ * after the Ethernet/802.3 header being
+ * 0xFFFF;
+ *
+ * Ethernet_802.2 frames, which are 802.3
+ * frames with an 802.2 LLC header and
+ * with the IPX LSAP as the DSAP in the LLC
+ * header;
+ *
+ * Ethernet_SNAP frames, which are 802.3
+ * frames with an LLC header and a SNAP
+ * header and with an OUI of 0x000000
+ * (encapsulated Ethernet) and a protocol
+ * ID of ETHERTYPE_IPX in the SNAP header.
+ *
+ * XXX - should we generate the same code both
+ * for tests for LLCSAP_IPX and for ETHERTYPE_IPX?
+ */
+
+ /*
+ * This generates code to check both for the
+ * IPX LSAP (Ethernet_802.2) and for Ethernet_802.3.
+ */
+ b0 = gen_cmp(OR_MACPL, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
+ b1 = gen_cmp(OR_MACPL, 0, BPF_H, (bpf_int32)0xFFFF);
+ gen_or(b0, b1);
+
+ /*
+ * Now we add code to check for SNAP frames with
+ * ETHERTYPE_IPX, i.e. Ethernet_SNAP.
+ */
+ b0 = gen_snap(0x000000, ETHERTYPE_IPX);
+ gen_or(b0, b1);
+
+ /*
+ * Now we generate code to check for 802.3
+ * frames in general.
+ */
+ b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
+ gen_not(b0);
+
+ /*
+ * Now add the check for 802.3 frames before the
+ * check for Ethernet_802.2 and Ethernet_802.3,
+ * as those checks should only be done on 802.3
+ * frames, not on Ethernet frames.
+ */
+ gen_and(b0, b1);
+
+ /*
+ * Now add the check for Ethernet_II frames, and
+ * do that before checking for the other frame
+ * types.
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
+ (bpf_int32)ETHERTYPE_IPX);
+ gen_or(b0, b1);
+ return b1;
+
+ case ETHERTYPE_ATALK:
+ case ETHERTYPE_AARP:
+ /*
+ * EtherTalk (AppleTalk protocols on Ethernet link
+ * layer) may use 802.2 encapsulation.
+ */
+
+ /*
+ * Check for 802.2 encapsulation (EtherTalk phase 2?);
+ * we check for an Ethernet type field less than
+ * 1500, which means it's an 802.3 length field.
+ */
+ b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
+ gen_not(b0);
+
+ /*
+ * 802.2-encapsulated ETHERTYPE_ATALK packets are
+ * SNAP packets with an organization code of
+ * 0x080007 (Apple, for Appletalk) and a protocol
+ * type of ETHERTYPE_ATALK (Appletalk).
+ *
+ * 802.2-encapsulated ETHERTYPE_AARP packets are
+ * SNAP packets with an organization code of
+ * 0x000000 (encapsulated Ethernet) and a protocol
+ * type of ETHERTYPE_AARP (Appletalk ARP).
+ */
+ if (proto == ETHERTYPE_ATALK)
+ b1 = gen_snap(0x080007, ETHERTYPE_ATALK);
+ else /* proto == ETHERTYPE_AARP */
+ b1 = gen_snap(0x000000, ETHERTYPE_AARP);
+ gen_and(b0, b1);
+
+ /*
+ * Check for Ethernet encapsulation (Ethertalk
+ * phase 1?); we just check for the Ethernet
+ * protocol type.
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
+
+ gen_or(b0, b1);
+ return b1;
+
+ default:
+ if (proto <= ETHERMTU) {
+ /*
+ * This is an LLC SAP value, so the frames
+ * that match would be 802.2 frames.
+ * Check that the frame is an 802.2 frame
+ * (i.e., that the length/type field is
+ * a length field, <= ETHERMTU) and
+ * then check the DSAP.
+ */
+ b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
+ gen_not(b0);
+ b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
+ (bpf_int32)proto);
+ gen_and(b0, b1);
+ return b1;
+ } else {
+ /*
+ * This is an Ethernet type, so compare
+ * the length/type field with it (if
+ * the frame is an 802.2 frame, the length
+ * field will be <= ETHERMTU, and, as
+ * "proto" is > ETHERMTU, this test
+ * will fail and the frame won't match,
+ * which is what we want).
+ */
+ return gen_cmp(OR_LINK, off_linktype, BPF_H,
+ (bpf_int32)proto);
+ }
+ }
+}
+
+/*
+ * Generate code to match a particular packet type.
+ *
+ * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
+ * value, if <= ETHERMTU. We use that to determine whether to
+ * match the type field or to check the type field for the special
+ * LINUX_SLL_P_802_2 value and then do the appropriate test.
+ */
+static struct block *
+gen_linux_sll_linktype(proto)
+ register int proto;
+{
+ struct block *b0, *b1;
+
+ switch (proto) {
+
+ case LLCSAP_ISONS:
+ case LLCSAP_IP:
+ case LLCSAP_NETBEUI:
+ /*
+ * OSI protocols and NetBEUI always use 802.2 encapsulation,
+ * so we check the DSAP and SSAP.
+ *
+ * LLCSAP_IP checks for IP-over-802.2, rather
+ * than IP-over-Ethernet or IP-over-SNAP.
+ *
+ * XXX - should we check both the DSAP and the
+ * SSAP, like this, or should we check just the
+ * DSAP, as we do for other types <= ETHERMTU
+ * (i.e., other SAP values)?
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
+ b1 = gen_cmp(OR_MACPL, 0, BPF_H, (bpf_int32)
+ ((proto << 8) | proto));
+ gen_and(b0, b1);
+ return b1;
+
+ case LLCSAP_IPX:
+ /*
+ * Ethernet_II frames, which are Ethernet
+ * frames with a frame type of ETHERTYPE_IPX;
+ *
+ * Ethernet_802.3 frames, which have a frame
+ * type of LINUX_SLL_P_802_3;
+ *
+ * Ethernet_802.2 frames, which are 802.3
+ * frames with an 802.2 LLC header (i.e, have
+ * a frame type of LINUX_SLL_P_802_2) and
+ * with the IPX LSAP as the DSAP in the LLC
+ * header;
+ *
+ * Ethernet_SNAP frames, which are 802.3
+ * frames with an LLC header and a SNAP
+ * header and with an OUI of 0x000000
+ * (encapsulated Ethernet) and a protocol
+ * ID of ETHERTYPE_IPX in the SNAP header.
+ *
+ * First, do the checks on LINUX_SLL_P_802_2
+ * frames; generate the check for either
+ * Ethernet_802.2 or Ethernet_SNAP frames, and
+ * then put a check for LINUX_SLL_P_802_2 frames
+ * before it.
+ */
+ b0 = gen_cmp(OR_MACPL, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
+ b1 = gen_snap(0x000000, ETHERTYPE_IPX);
+ gen_or(b0, b1);
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
+ gen_and(b0, b1);
+
+ /*
+ * Now check for 802.3 frames and OR that with
+ * the previous test.
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_3);
+ gen_or(b0, b1);
+
+ /*
+ * Now add the check for Ethernet_II frames, and
+ * do that before checking for the other frame
+ * types.
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
+ (bpf_int32)ETHERTYPE_IPX);
+ gen_or(b0, b1);
+ return b1;
+
+ case ETHERTYPE_ATALK:
+ case ETHERTYPE_AARP:
+ /*
+ * EtherTalk (AppleTalk protocols on Ethernet link
+ * layer) may use 802.2 encapsulation.
+ */
+
+ /*
+ * Check for 802.2 encapsulation (EtherTalk phase 2?);
+ * we check for the 802.2 protocol type in the
+ * "Ethernet type" field.
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, LINUX_SLL_P_802_2);
+
+ /*
+ * 802.2-encapsulated ETHERTYPE_ATALK packets are
+ * SNAP packets with an organization code of
+ * 0x080007 (Apple, for Appletalk) and a protocol
+ * type of ETHERTYPE_ATALK (Appletalk).
+ *
+ * 802.2-encapsulated ETHERTYPE_AARP packets are
+ * SNAP packets with an organization code of
+ * 0x000000 (encapsulated Ethernet) and a protocol
+ * type of ETHERTYPE_AARP (Appletalk ARP).
+ */
+ if (proto == ETHERTYPE_ATALK)
+ b1 = gen_snap(0x080007, ETHERTYPE_ATALK);
+ else /* proto == ETHERTYPE_AARP */
+ b1 = gen_snap(0x000000, ETHERTYPE_AARP);
+ gen_and(b0, b1);
+
+ /*
+ * Check for Ethernet encapsulation (Ethertalk
+ * phase 1?); we just check for the Ethernet
+ * protocol type.
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
+
+ gen_or(b0, b1);
+ return b1;
+
+ default:
+ if (proto <= ETHERMTU) {
+ /*
+ * This is an LLC SAP value, so the frames
+ * that match would be 802.2 frames.
+ * Check for the 802.2 protocol type
+ * in the "Ethernet type" field, and
+ * then check the DSAP.
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
+ LINUX_SLL_P_802_2);
+ b1 = gen_cmp(OR_LINK, off_macpl, BPF_B,
+ (bpf_int32)proto);
+ gen_and(b0, b1);
+ return b1;
+ } else {
+ /*
+ * This is an Ethernet type, so compare
+ * the length/type field with it (if
+ * the frame is an 802.2 frame, the length
+ * field will be <= ETHERMTU, and, as
+ * "proto" is > ETHERMTU, this test
+ * will fail and the frame won't match,
+ * which is what we want).
+ */
+ return gen_cmp(OR_LINK, off_linktype, BPF_H,
+ (bpf_int32)proto);
+ }
+ }
+}
+
+static struct slist *
+gen_load_prism_llprefixlen()
+{
+ struct slist *s1, *s2;
+ struct slist *sjeq_avs_cookie;
+ struct slist *sjcommon;
+
+ /*
+ * This code is not compatible with the optimizer, as
+ * we are generating jmp instructions within a normal
+ * slist of instructions
+ */
+ no_optimize = 1;
+
+ /*
+ * Generate code to load the length of the radio header into
+ * the register assigned to hold that length, if one has been
+ * assigned. (If one hasn't been assigned, no code we've
+ * generated uses that prefix, so we don't need to generate any
+ * code to load it.)
+ *
+ * Some Linux drivers use ARPHRD_IEEE80211_PRISM but sometimes
+ * or always use the AVS header rather than the Prism header.
+ * We load a 4-byte big-endian value at the beginning of the
+ * raw packet data, and see whether, when masked with 0xFFFFF000,
+ * it's equal to 0x80211000. If so, that indicates that it's
+ * an AVS header (the masked-out bits are the version number).
+ * Otherwise, it's a Prism header.
+ *
+ * XXX - the Prism header is also, in theory, variable-length,
+ * but no known software generates headers that aren't 144
+ * bytes long.
+ */
+ if (reg_off_ll != -1) {
+ /*
+ * Load the cookie.
+ */
+ s1 = new_stmt(BPF_LD|BPF_W|BPF_ABS);
+ s1->s.k = 0;
+
+ /*
+ * AND it with 0xFFFFF000.
+ */
+ s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K);
+ s2->s.k = 0xFFFFF000;
+ sappend(s1, s2);
+
+ /*
+ * Compare with 0x80211000.
+ */
+ sjeq_avs_cookie = new_stmt(JMP(BPF_JEQ));
+ sjeq_avs_cookie->s.k = 0x80211000;
+ sappend(s1, sjeq_avs_cookie);
+
+ /*
+ * If it's AVS:
+ *
+ * The 4 bytes at an offset of 4 from the beginning of
+ * the AVS header are the length of the AVS header.
+ * That field is big-endian.
+ */
+ s2 = new_stmt(BPF_LD|BPF_W|BPF_ABS);
+ s2->s.k = 4;
+ sappend(s1, s2);
+ sjeq_avs_cookie->s.jt = s2;
+
+ /*
+ * Now jump to the code to allocate a register
+ * into which to save the header length and
+ * store the length there. (The "jump always"
+ * instruction needs to have the k field set;
+ * it's added to the PC, so, as we're jumping
+ * over a single instruction, it should be 1.)
+ */
+ sjcommon = new_stmt(JMP(BPF_JA));
+ sjcommon->s.k = 1;
+ sappend(s1, sjcommon);
+
+ /*
+ * Now for the code that handles the Prism header.
+ * Just load the length of the Prism header (144)
+ * into the A register. Have the test for an AVS
+ * header branch here if we don't have an AVS header.
+ */
+ s2 = new_stmt(BPF_LD|BPF_W|BPF_IMM);
+ s2->s.k = 144;
+ sappend(s1, s2);
+ sjeq_avs_cookie->s.jf = s2;
+
+ /*
+ * Now allocate a register to hold that value and store
+ * it. The code for the AVS header will jump here after
+ * loading the length of the AVS header.
+ */
+ s2 = new_stmt(BPF_ST);
+ s2->s.k = reg_off_ll;
+ sappend(s1, s2);
+ sjcommon->s.jf = s2;
+
+ /*
+ * Now move it into the X register.
+ */
+ s2 = new_stmt(BPF_MISC|BPF_TAX);
+ sappend(s1, s2);
+
+ return (s1);
+ } else
+ return (NULL);
+}
+
+static struct slist *
+gen_load_avs_llprefixlen()
+{
+ struct slist *s1, *s2;
+
+ /*
+ * Generate code to load the length of the AVS header into
+ * the register assigned to hold that length, if one has been
+ * assigned. (If one hasn't been assigned, no code we've
+ * generated uses that prefix, so we don't need to generate any
+ * code to load it.)
+ */
+ if (reg_off_ll != -1) {
+ /*
+ * The 4 bytes at an offset of 4 from the beginning of
+ * the AVS header are the length of the AVS header.
+ * That field is big-endian.
+ */
+ s1 = new_stmt(BPF_LD|BPF_W|BPF_ABS);
+ s1->s.k = 4;
+
+ /*
+ * Now allocate a register to hold that value and store
+ * it.
+ */
+ s2 = new_stmt(BPF_ST);
+ s2->s.k = reg_off_ll;
+ sappend(s1, s2);
+
+ /*
+ * Now move it into the X register.
+ */
+ s2 = new_stmt(BPF_MISC|BPF_TAX);
+ sappend(s1, s2);
+
+ return (s1);
+ } else
+ return (NULL);
+}
+
+static struct slist *
+gen_load_radiotap_llprefixlen()
+{
+ struct slist *s1, *s2;
+
+ /*
+ * Generate code to load the length of the radiotap header into
+ * the register assigned to hold that length, if one has been
+ * assigned. (If one hasn't been assigned, no code we've
+ * generated uses that prefix, so we don't need to generate any
+ * code to load it.)
+ */
+ if (reg_off_ll != -1) {
+ /*
+ * The 2 bytes at offsets of 2 and 3 from the beginning
+ * of the radiotap header are the length of the radiotap
+ * header; unfortunately, it's little-endian, so we have
+ * to load it a byte at a time and construct the value.
+ */
+
+ /*
+ * Load the high-order byte, at an offset of 3, shift it
+ * left a byte, and put the result in the X register.
+ */
+ s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
+ s1->s.k = 3;
+ s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
+ sappend(s1, s2);
+ s2->s.k = 8;
+ s2 = new_stmt(BPF_MISC|BPF_TAX);
+ sappend(s1, s2);
+
+ /*
+ * Load the next byte, at an offset of 2, and OR the
+ * value from the X register into it.
+ */
+ s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
+ sappend(s1, s2);
+ s2->s.k = 2;
+ s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X);
+ sappend(s1, s2);
+
+ /*
+ * Now allocate a register to hold that value and store
+ * it.
+ */
+ s2 = new_stmt(BPF_ST);
+ s2->s.k = reg_off_ll;
+ sappend(s1, s2);
+
+ /*
+ * Now move it into the X register.
+ */
+ s2 = new_stmt(BPF_MISC|BPF_TAX);
+ sappend(s1, s2);
+
+ return (s1);
+ } else
+ return (NULL);
+}
+
+/*
+ * At the moment we treat PPI as normal Radiotap encoded
+ * packets. The difference is in the function that generates
+ * the code at the beginning to compute the header length.
+ * Since this code generator of PPI supports bare 802.11
+ * encapsulation only (i.e. the encapsulated DLT should be
+ * DLT_IEEE802_11) we generate code to check for this too;
+ * that's done in finish_parse().
+ */
+static struct slist *
+gen_load_ppi_llprefixlen()
+{
+ struct slist *s1, *s2;
+
+ /*
+ * Generate code to load the length of the radiotap header
+ * into the register assigned to hold that length, if one has
+ * been assigned.
+ */
+ if (reg_off_ll != -1) {
+ /*
+ * The 2 bytes at offsets of 2 and 3 from the beginning
+ * of the radiotap header are the length of the radiotap
+ * header; unfortunately, it's little-endian, so we have
+ * to load it a byte at a time and construct the value.
+ */
+
+ /*
+ * Load the high-order byte, at an offset of 3, shift it
+ * left a byte, and put the result in the X register.
+ */
+ s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
+ s1->s.k = 3;
+ s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K);
+ sappend(s1, s2);
+ s2->s.k = 8;
+ s2 = new_stmt(BPF_MISC|BPF_TAX);
+ sappend(s1, s2);
+
+ /*
+ * Load the next byte, at an offset of 2, and OR the
+ * value from the X register into it.
+ */
+ s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
+ sappend(s1, s2);
+ s2->s.k = 2;
+ s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X);
+ sappend(s1, s2);
+
+ /*
+ * Now allocate a register to hold that value and store
+ * it.
+ */
+ s2 = new_stmt(BPF_ST);
+ s2->s.k = reg_off_ll;
+ sappend(s1, s2);
+
+ /*
+ * Now move it into the X register.
+ */
+ s2 = new_stmt(BPF_MISC|BPF_TAX);
+ sappend(s1, s2);
+
+ return (s1);
+ } else
+ return (NULL);
+}
+
+/*
+ * Load a value relative to the beginning of the link-layer header after the 802.11
+ * header, i.e. LLC_SNAP.
+ * The link-layer header doesn't necessarily begin at the beginning
+ * of the packet data; there might be a variable-length prefix containing
+ * radio information.
+ */
+static struct slist *
+gen_load_802_11_header_len(struct slist *s, struct slist *snext)
+{
+ struct slist *s2;
+ struct slist *sjset_data_frame_1;
+ struct slist *sjset_data_frame_2;
+ struct slist *sjset_qos;
+ struct slist *sjset_radiotap_flags;
+ struct slist *sjset_radiotap_tsft;
+ struct slist *sjset_tsft_datapad, *sjset_notsft_datapad;
+ struct slist *s_roundup;
+
+ if (reg_off_macpl == -1) {
+ /*
+ * No register has been assigned to the offset of
+ * the MAC-layer payload, which means nobody needs
+ * it; don't bother computing it - just return
+ * what we already have.
+ */
+ return (s);
+ }
+
+ /*
+ * This code is not compatible with the optimizer, as
+ * we are generating jmp instructions within a normal
+ * slist of instructions
+ */
+ no_optimize = 1;
+
+ /*
+ * If "s" is non-null, it has code to arrange that the X register
+ * contains the length of the prefix preceding the link-layer
+ * header.
+ *
+ * Otherwise, the length of the prefix preceding the link-layer
+ * header is "off_ll".
+ */
+ if (s == NULL) {
+ /*
+ * There is no variable-length header preceding the
+ * link-layer header.
+ *
+ * Load the length of the fixed-length prefix preceding
+ * the link-layer header (if any) into the X register,
+ * and store it in the reg_off_macpl register.
+ * That length is off_ll.
+ */
+ s = new_stmt(BPF_LDX|BPF_IMM);
+ s->s.k = off_ll;
+ }
+
+ /*
+ * The X register contains the offset of the beginning of the
+ * link-layer header; add 24, which is the minimum length
+ * of the MAC header for a data frame, to that, and store it
+ * in reg_off_macpl, and then load the Frame Control field,
+ * which is at the offset in the X register, with an indexed load.
+ */
+ s2 = new_stmt(BPF_MISC|BPF_TXA);
+ sappend(s, s2);
+ s2 = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
+ s2->s.k = 24;
+ sappend(s, s2);
+ s2 = new_stmt(BPF_ST);
+ s2->s.k = reg_off_macpl;
+ sappend(s, s2);
+
+ s2 = new_stmt(BPF_LD|BPF_IND|BPF_B);
+ s2->s.k = 0;
+ sappend(s, s2);
+
+ /*
+ * Check the Frame Control field to see if this is a data frame;
+ * a data frame has the 0x08 bit (b3) in that field set and the
+ * 0x04 bit (b2) clear.
+ */
+ sjset_data_frame_1 = new_stmt(JMP(BPF_JSET));
+ sjset_data_frame_1->s.k = 0x08;
+ sappend(s, sjset_data_frame_1);
+
+ /*
+ * If b3 is set, test b2, otherwise go to the first statement of
+ * the rest of the program.
+ */
+ sjset_data_frame_1->s.jt = sjset_data_frame_2 = new_stmt(JMP(BPF_JSET));
+ sjset_data_frame_2->s.k = 0x04;
+ sappend(s, sjset_data_frame_2);
+ sjset_data_frame_1->s.jf = snext;
+
+ /*
+ * If b2 is not set, this is a data frame; test the QoS bit.
+ * Otherwise, go to the first statement of the rest of the
+ * program.
+ */
+ sjset_data_frame_2->s.jt = snext;
+ sjset_data_frame_2->s.jf = sjset_qos = new_stmt(JMP(BPF_JSET));
+ sjset_qos->s.k = 0x80; /* QoS bit */
+ sappend(s, sjset_qos);
+
+ /*
+ * If it's set, add 2 to reg_off_macpl, to skip the QoS
+ * field.
+ * Otherwise, go to the first statement of the rest of the
+ * program.
+ */
+ sjset_qos->s.jt = s2 = new_stmt(BPF_LD|BPF_MEM);
+ s2->s.k = reg_off_macpl;
+ sappend(s, s2);
+ s2 = new_stmt(BPF_ALU|BPF_ADD|BPF_IMM);
+ s2->s.k = 2;
+ sappend(s, s2);
+ s2 = new_stmt(BPF_ST);
+ s2->s.k = reg_off_macpl;
+ sappend(s, s2);
+
+ /*
+ * If we have a radiotap header, look at it to see whether
+ * there's Atheros padding between the MAC-layer header
+ * and the payload.
+ *
+ * Note: all of the fields in the radiotap header are
+ * little-endian, so we byte-swap all of the values
+ * we test against, as they will be loaded as big-endian
+ * values.
+ */
+ if (linktype == DLT_IEEE802_11_RADIO) {
+ /*
+ * Is the IEEE80211_RADIOTAP_FLAGS bit (0x0000002) set
+ * in the presence flag?
+ */
+ sjset_qos->s.jf = s2 = new_stmt(BPF_LD|BPF_ABS|BPF_W);
+ s2->s.k = 4;
+ sappend(s, s2);
+
+ sjset_radiotap_flags = new_stmt(JMP(BPF_JSET));
+ sjset_radiotap_flags->s.k = SWAPLONG(0x00000002);
+ sappend(s, sjset_radiotap_flags);
+
+ /*
+ * If not, skip all of this.
+ */
+ sjset_radiotap_flags->s.jf = snext;
+
+ /*
+ * Otherwise, is the IEEE80211_RADIOTAP_TSFT bit set?
+ */
+ sjset_radiotap_tsft = sjset_radiotap_flags->s.jt =
+ new_stmt(JMP(BPF_JSET));
+ sjset_radiotap_tsft->s.k = SWAPLONG(0x00000001);
+ sappend(s, sjset_radiotap_tsft);
+
+ /*
+ * If IEEE80211_RADIOTAP_TSFT is set, the flags field is
+ * at an offset of 16 from the beginning of the raw packet
+ * data (8 bytes for the radiotap header and 8 bytes for
+ * the TSFT field).
+ *
+ * Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20)
+ * is set.
+ */
+ sjset_radiotap_tsft->s.jt = s2 = new_stmt(BPF_LD|BPF_ABS|BPF_B);
+ s2->s.k = 16;
+ sappend(s, s2);
+
+ sjset_tsft_datapad = new_stmt(JMP(BPF_JSET));
+ sjset_tsft_datapad->s.k = 0x20;
+ sappend(s, sjset_tsft_datapad);
+
+ /*
+ * If IEEE80211_RADIOTAP_TSFT is not set, the flags field is
+ * at an offset of 8 from the beginning of the raw packet
+ * data (8 bytes for the radiotap header).
+ *
+ * Test whether the IEEE80211_RADIOTAP_F_DATAPAD bit (0x20)
+ * is set.
+ */
+ sjset_radiotap_tsft->s.jf = s2 = new_stmt(BPF_LD|BPF_ABS|BPF_B);
+ s2->s.k = 8;
+ sappend(s, s2);
+
+ sjset_notsft_datapad = new_stmt(JMP(BPF_JSET));
+ sjset_notsft_datapad->s.k = 0x20;
+ sappend(s, sjset_notsft_datapad);
+
+ /*
+ * In either case, if IEEE80211_RADIOTAP_F_DATAPAD is
+ * set, round the length of the 802.11 header to
+ * a multiple of 4. Do that by adding 3 and then
+ * dividing by and multiplying by 4, which we do by
+ * ANDing with ~3.
+ */
+ s_roundup = new_stmt(BPF_LD|BPF_MEM);
+ s_roundup->s.k = reg_off_macpl;
+ sappend(s, s_roundup);
+ s2 = new_stmt(BPF_ALU|BPF_ADD|BPF_IMM);
+ s2->s.k = 3;
+ sappend(s, s2);
+ s2 = new_stmt(BPF_ALU|BPF_AND|BPF_IMM);
+ s2->s.k = ~3;
+ sappend(s, s2);
+ s2 = new_stmt(BPF_ST);
+ s2->s.k = reg_off_macpl;
+ sappend(s, s2);
+
+ sjset_tsft_datapad->s.jt = s_roundup;
+ sjset_tsft_datapad->s.jf = snext;
+ sjset_notsft_datapad->s.jt = s_roundup;
+ sjset_notsft_datapad->s.jf = snext;
+ } else
+ sjset_qos->s.jf = snext;
+
+ return s;
+}
+
+static void
+insert_compute_vloffsets(b)
+ struct block *b;
+{
+ struct slist *s;
+
+ /*
+ * For link-layer types that have a variable-length header
+ * preceding the link-layer header, generate code to load
+ * the offset of the link-layer header into the register
+ * assigned to that offset, if any.
+ */
+ switch (linktype) {
+
+ case DLT_PRISM_HEADER:
+ s = gen_load_prism_llprefixlen();
+ break;
+
+ case DLT_IEEE802_11_RADIO_AVS:
+ s = gen_load_avs_llprefixlen();
+ break;
+
+ case DLT_IEEE802_11_RADIO:
+ s = gen_load_radiotap_llprefixlen();
+ break;
+
+ case DLT_PPI:
+ s = gen_load_ppi_llprefixlen();
+ break;
+
+ default:
+ s = NULL;
+ break;
+ }
+
+ /*
+ * For link-layer types that have a variable-length link-layer
+ * header, generate code to load the offset of the MAC-layer
+ * payload into the register assigned to that offset, if any.
+ */
+ switch (linktype) {
+
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
+ s = gen_load_802_11_header_len(s, b->stmts);
+ break;
+ }
+
+ /*
+ * If we have any offset-loading code, append all the
+ * existing statements in the block to those statements,
+ * and make the resulting list the list of statements
+ * for the block.
+ */
+ if (s != NULL) {
+ sappend(s, b->stmts);
+ b->stmts = s;
+ }
+}
+
+static struct block *
+gen_ppi_dlt_check(void)
+{
+ struct slist *s_load_dlt;
+ struct block *b;
+
+ if (linktype == DLT_PPI)
+ {
+ /* Create the statements that check for the DLT
+ */
+ s_load_dlt = new_stmt(BPF_LD|BPF_W|BPF_ABS);
+ s_load_dlt->s.k = 4;
+
+ b = new_block(JMP(BPF_JEQ));
+
+ b->stmts = s_load_dlt;
+ b->s.k = SWAPLONG(DLT_IEEE802_11);
+ }
+ else
+ {
+ b = NULL;
+ }
+
+ return b;
+}
+
+static struct slist *
+gen_prism_llprefixlen(void)
+{
+ struct slist *s;
+
+ if (reg_off_ll == -1) {
+ /*
+ * We haven't yet assigned a register for the length
+ * of the radio header; allocate one.
+ */
+ reg_off_ll = alloc_reg();
+ }
+
+ /*
+ * Load the register containing the radio length
+ * into the X register.
+ */
+ s = new_stmt(BPF_LDX|BPF_MEM);
+ s->s.k = reg_off_ll;
+ return s;
+}
+
+static struct slist *
+gen_avs_llprefixlen(void)
+{
+ struct slist *s;
+
+ if (reg_off_ll == -1) {
+ /*
+ * We haven't yet assigned a register for the length
+ * of the AVS header; allocate one.
+ */
+ reg_off_ll = alloc_reg();
+ }
+
+ /*
+ * Load the register containing the AVS length
+ * into the X register.
+ */
+ s = new_stmt(BPF_LDX|BPF_MEM);
+ s->s.k = reg_off_ll;
+ return s;
+}
+
+static struct slist *
+gen_radiotap_llprefixlen(void)
+{
+ struct slist *s;
+
+ if (reg_off_ll == -1) {
+ /*
+ * We haven't yet assigned a register for the length
+ * of the radiotap header; allocate one.
+ */
+ reg_off_ll = alloc_reg();
+ }
+
+ /*
+ * Load the register containing the radiotap length
+ * into the X register.
+ */
+ s = new_stmt(BPF_LDX|BPF_MEM);
+ s->s.k = reg_off_ll;
+ return s;
+}
+
+/*
+ * At the moment we treat PPI as normal Radiotap encoded
+ * packets. The difference is in the function that generates
+ * the code at the beginning to compute the header length.
+ * Since this code generator of PPI supports bare 802.11
+ * encapsulation only (i.e. the encapsulated DLT should be
+ * DLT_IEEE802_11) we generate code to check for this too.
+ */
+static struct slist *
+gen_ppi_llprefixlen(void)
+{
+ struct slist *s;
+
+ if (reg_off_ll == -1) {
+ /*
+ * We haven't yet assigned a register for the length
+ * of the radiotap header; allocate one.
+ */
+ reg_off_ll = alloc_reg();
+ }
+
+ /*
+ * Load the register containing the PPI length
+ * into the X register.
+ */
+ s = new_stmt(BPF_LDX|BPF_MEM);
+ s->s.k = reg_off_ll;
+ return s;
+}
+
+/*
+ * Generate code to compute the link-layer header length, if necessary,
+ * putting it into the X register, and to return either a pointer to a
+ * "struct slist" for the list of statements in that code, or NULL if
+ * no code is necessary.
+ */
+static struct slist *
+gen_llprefixlen(void)
+{
+ switch (linktype) {
+
+ case DLT_PRISM_HEADER:
+ return gen_prism_llprefixlen();
+
+ case DLT_IEEE802_11_RADIO_AVS:
+ return gen_avs_llprefixlen();
+
+ case DLT_IEEE802_11_RADIO:
+ return gen_radiotap_llprefixlen();
+
+ case DLT_PPI:
+ return gen_ppi_llprefixlen();
+
+ default:
+ return NULL;
+ }
+}
+
+/*
+ * Generate code to load the register containing the offset of the
+ * MAC-layer payload into the X register; if no register for that offset
+ * has been allocated, allocate it first.
+ */
+static struct slist *
+gen_off_macpl(void)
+{
+ struct slist *s;
+
+ if (off_macpl_is_variable) {
+ if (reg_off_macpl == -1) {
+ /*
+ * We haven't yet assigned a register for the offset
+ * of the MAC-layer payload; allocate one.
+ */
+ reg_off_macpl = alloc_reg();
+ }
+
+ /*
+ * Load the register containing the offset of the MAC-layer
+ * payload into the X register.
+ */
+ s = new_stmt(BPF_LDX|BPF_MEM);
+ s->s.k = reg_off_macpl;
+ return s;
+ } else {
+ /*
+ * That offset isn't variable, so we don't need to
+ * generate any code.
+ */
+ return NULL;
+ }
+}
+
+/*
+ * Map an Ethernet type to the equivalent PPP type.
+ */
+static int
+ethertype_to_ppptype(proto)
+ int proto;
+{
+ switch (proto) {
+
+ case ETHERTYPE_IP:
+ proto = PPP_IP;
+ break;
+
+#ifdef INET6
+ case ETHERTYPE_IPV6:
+ proto = PPP_IPV6;
+ break;
+#endif
+
+ case ETHERTYPE_DN:
+ proto = PPP_DECNET;
+ break;
+
+ case ETHERTYPE_ATALK:
+ proto = PPP_APPLE;
+ break;
+
+ case ETHERTYPE_NS:
+ proto = PPP_NS;
+ break;
+
+ case LLCSAP_ISONS:
+ proto = PPP_OSI;
+ break;
+
+ case LLCSAP_8021D:
+ /*
+ * I'm assuming the "Bridging PDU"s that go
+ * over PPP are Spanning Tree Protocol
+ * Bridging PDUs.
+ */
+ proto = PPP_BRPDU;
+ break;
+
+ case LLCSAP_IPX:
+ proto = PPP_IPX;
+ break;
+ }
+ return (proto);
+}
+
+/*
+ * Generate code to match a particular packet type by matching the
+ * link-layer type field or fields in the 802.2 LLC header.
+ *
+ * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
+ * value, if <= ETHERMTU.
+ */
+static struct block *
+gen_linktype(proto)
+ register int proto;
+{
+ struct block *b0, *b1, *b2;
+
+ /* are we checking MPLS-encapsulated packets? */
+ if (label_stack_depth > 0) {
+ switch (proto) {
+ case ETHERTYPE_IP:
+ case PPP_IP:
+ /* FIXME add other L3 proto IDs */
+ return gen_mpls_linktype(Q_IP);
+
+ case ETHERTYPE_IPV6:
+ case PPP_IPV6:
+ /* FIXME add other L3 proto IDs */
+ return gen_mpls_linktype(Q_IPV6);
+
+ default:
+ bpf_error("unsupported protocol over mpls");
+ /* NOTREACHED */
+ }
+ }
+
+ /*
+ * Are we testing PPPoE packets?
+ */
+ if (is_pppoes) {
+ /*
+ * The PPPoE session header is part of the
+ * MAC-layer payload, so all references
+ * should be relative to the beginning of
+ * that payload.
+ */
+
+ /*
+ * We use Ethernet protocol types inside libpcap;
+ * map them to the corresponding PPP protocol types.
+ */
+ proto = ethertype_to_ppptype(proto);
+ return gen_cmp(OR_MACPL, off_linktype, BPF_H, (bpf_int32)proto);
+ }
+
+ switch (linktype) {
+
+ case DLT_EN10MB:
+ return gen_ether_linktype(proto);
+ /*NOTREACHED*/
+ break;
+
+ case DLT_C_HDLC:
+ switch (proto) {
+
+ case LLCSAP_ISONS:
+ proto = (proto << 8 | LLCSAP_ISONS);
+ /* fall through */
+
+ default:
+ return gen_cmp(OR_LINK, off_linktype, BPF_H,
+ (bpf_int32)proto);
+ /*NOTREACHED*/
+ break;
+ }
+ break;
+
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
+ /*
+ * Check that we have a data frame.
+ */
+ b0 = gen_check_802_11_data_frame();
+
+ /*
+ * Now check for the specified link-layer type.
+ */
+ b1 = gen_llc_linktype(proto);
+ gen_and(b0, b1);
+ return b1;
+ /*NOTREACHED*/
+ break;
+
+ case DLT_FDDI:
+ /*
+ * XXX - check for asynchronous frames, as per RFC 1103.
+ */
+ return gen_llc_linktype(proto);
+ /*NOTREACHED*/
+ break;
+
+ case DLT_IEEE802:
+ /*
+ * XXX - check for LLC PDUs, as per IEEE 802.5.
+ */
+ return gen_llc_linktype(proto);
+ /*NOTREACHED*/
+ break;
+
+ case DLT_ATM_RFC1483:
+ case DLT_ATM_CLIP:
+ case DLT_IP_OVER_FC:
+ return gen_llc_linktype(proto);
+ /*NOTREACHED*/
+ break;
+
+ case DLT_SUNATM:
+ /*
+ * If "is_lane" is set, check for a LANE-encapsulated
+ * version of this protocol, otherwise check for an
+ * LLC-encapsulated version of this protocol.
+ *
+ * We assume LANE means Ethernet, not Token Ring.
+ */
+ if (is_lane) {
+ /*
+ * Check that the packet doesn't begin with an
+ * LE Control marker. (We've already generated
+ * a test for LANE.)
+ */
+ b0 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
+ 0xFF00);
+ gen_not(b0);
+
+ /*
+ * Now generate an Ethernet test.
+ */
+ b1 = gen_ether_linktype(proto);
+ gen_and(b0, b1);
+ return b1;
+ } else {
+ /*
+ * Check for LLC encapsulation and then check the
+ * protocol.
+ */
+ b0 = gen_atmfield_code(A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
+ b1 = gen_llc_linktype(proto);
+ gen_and(b0, b1);
+ return b1;
+ }
+ /*NOTREACHED*/
+ break;
+
+ case DLT_LINUX_SLL:
+ return gen_linux_sll_linktype(proto);
+ /*NOTREACHED*/
+ break;
+
+ case DLT_SLIP:
+ case DLT_SLIP_BSDOS:
+ case DLT_RAW:
+ /*
+ * These types don't provide any type field; packets
+ * are always IPv4 or IPv6.
+ *
+ * XXX - for IPv4, check for a version number of 4, and,
+ * for IPv6, check for a version number of 6?
+ */
+ switch (proto) {
+
+ case ETHERTYPE_IP:
+ /* Check for a version number of 4. */
+ return gen_mcmp(OR_LINK, 0, BPF_B, 0x40, 0xF0);
+#ifdef INET6
+ case ETHERTYPE_IPV6:
+ /* Check for a version number of 6. */
+ return gen_mcmp(OR_LINK, 0, BPF_B, 0x60, 0xF0);
+#endif
+
+ default:
+ return gen_false(); /* always false */
+ }
+ /*NOTREACHED*/
+ break;
+
+ case DLT_PPP:
+ case DLT_PPP_PPPD:
+ case DLT_PPP_SERIAL:
+ case DLT_PPP_ETHER:
+ /*
+ * We use Ethernet protocol types inside libpcap;
+ * map them to the corresponding PPP protocol types.
+ */
+ proto = ethertype_to_ppptype(proto);
+ return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
+ /*NOTREACHED*/
+ break;
+
+ case DLT_PPP_BSDOS:
+ /*
+ * We use Ethernet protocol types inside libpcap;
+ * map them to the corresponding PPP protocol types.
+ */
+ switch (proto) {
+
+ case ETHERTYPE_IP:
+ /*
+ * Also check for Van Jacobson-compressed IP.
+ * XXX - do this for other forms of PPP?
+ */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_IP);
+ b1 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJC);
+ gen_or(b0, b1);
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJNC);
+ gen_or(b1, b0);
+ return b0;
+
+ default:
+ proto = ethertype_to_ppptype(proto);
+ return gen_cmp(OR_LINK, off_linktype, BPF_H,
+ (bpf_int32)proto);
+ }
+ /*NOTREACHED*/
+ break;
+
+ case DLT_NULL:
+ case DLT_LOOP:
+ case DLT_ENC:
+ /*
+ * For DLT_NULL, the link-layer header is a 32-bit
+ * word containing an AF_ value in *host* byte order,
+ * and for DLT_ENC, the link-layer header begins
+ * with a 32-bit work containing an AF_ value in
+ * host byte order.
+ *
+ * In addition, if we're reading a saved capture file,
+ * the host byte order in the capture may not be the
+ * same as the host byte order on this machine.
+ *
+ * For DLT_LOOP, the link-layer header is a 32-bit
+ * word containing an AF_ value in *network* byte order.
+ *
+ * XXX - AF_ values may, unfortunately, be platform-
+ * dependent; for example, FreeBSD's AF_INET6 is 24
+ * whilst NetBSD's and OpenBSD's is 26.
+ *
+ * This means that, when reading a capture file, just
+ * checking for our AF_INET6 value won't work if the
+ * capture file came from another OS.
+ */
+ switch (proto) {
+
+ case ETHERTYPE_IP:
+ proto = AF_INET;
+ break;
+
+#ifdef INET6
+ case ETHERTYPE_IPV6:
+ proto = AF_INET6;
+ break;
+#endif
+
+ default:
+ /*
+ * Not a type on which we support filtering.
+ * XXX - support those that have AF_ values
+ * #defined on this platform, at least?
+ */
+ return gen_false();
+ }
+
+ if (linktype == DLT_NULL || linktype == DLT_ENC) {
+ /*
+ * The AF_ value is in host byte order, but
+ * the BPF interpreter will convert it to
+ * network byte order.
+ *
+ * If this is a save file, and it's from a
+ * machine with the opposite byte order to
+ * ours, we byte-swap the AF_ value.
+ *
+ * Then we run it through "htonl()", and
+ * generate code to compare against the result.
+ */
+ if (bpf_pcap->sf.rfile != NULL &&
+ bpf_pcap->sf.swapped)
+ proto = SWAPLONG(proto);
+ proto = htonl(proto);
+ }
+ return (gen_cmp(OR_LINK, 0, BPF_W, (bpf_int32)proto));
+
+#ifdef HAVE_NET_PFVAR_H
+ case DLT_PFLOG:
+ /*
+ * af field is host byte order in contrast to the rest of
+ * the packet.
+ */
+ if (proto == ETHERTYPE_IP)
+ return (gen_cmp(OR_LINK, offsetof(struct pfloghdr, af),
+ BPF_B, (bpf_int32)AF_INET));
+#ifdef INET6
+ else if (proto == ETHERTYPE_IPV6)
+ return (gen_cmp(OR_LINK, offsetof(struct pfloghdr, af),
+ BPF_B, (bpf_int32)AF_INET6));
+#endif /* INET6 */
+ else
+ return gen_false();
+ /*NOTREACHED*/
+ break;
+#endif /* HAVE_NET_PFVAR_H */
+
+ case DLT_ARCNET:
+ case DLT_ARCNET_LINUX:
+ /*
+ * XXX should we check for first fragment if the protocol
+ * uses PHDS?
+ */
+ switch (proto) {
+
+ default:
+ return gen_false();
+
+#ifdef INET6
+ case ETHERTYPE_IPV6:
+ return (gen_cmp(OR_LINK, off_linktype, BPF_B,
+ (bpf_int32)ARCTYPE_INET6));
+#endif /* INET6 */
+
+ case ETHERTYPE_IP:
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_B,
+ (bpf_int32)ARCTYPE_IP);
+ b1 = gen_cmp(OR_LINK, off_linktype, BPF_B,
+ (bpf_int32)ARCTYPE_IP_OLD);
+ gen_or(b0, b1);
+ return (b1);
+
+ case ETHERTYPE_ARP:
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_B,
+ (bpf_int32)ARCTYPE_ARP);
+ b1 = gen_cmp(OR_LINK, off_linktype, BPF_B,
+ (bpf_int32)ARCTYPE_ARP_OLD);
+ gen_or(b0, b1);
+ return (b1);
+
+ case ETHERTYPE_REVARP:
+ return (gen_cmp(OR_LINK, off_linktype, BPF_B,
+ (bpf_int32)ARCTYPE_REVARP));
+
+ case ETHERTYPE_ATALK:
+ return (gen_cmp(OR_LINK, off_linktype, BPF_B,
+ (bpf_int32)ARCTYPE_ATALK));
+ }
+ /*NOTREACHED*/
+ break;
+
+ case DLT_LTALK:
+ switch (proto) {
+ case ETHERTYPE_ATALK:
+ return gen_true();
+ default:
+ return gen_false();
+ }
+ /*NOTREACHED*/
+ break;
+
+ case DLT_FRELAY:
+ /*
+ * XXX - assumes a 2-byte Frame Relay header with
+ * DLCI and flags. What if the address is longer?
+ */
+ switch (proto) {
+
+ case ETHERTYPE_IP:
+ /*
+ * Check for the special NLPID for IP.
+ */
+ return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0xcc);
+
+#ifdef INET6
+ case ETHERTYPE_IPV6:
+ /*
+ * Check for the special NLPID for IPv6.
+ */
+ return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0x8e);
+#endif
+
+ case LLCSAP_ISONS:
+ /*
+ * Check for several OSI protocols.
+ *
+ * Frame Relay packets typically have an OSI
+ * NLPID at the beginning; we check for each
+ * of them.
+ *
+ * What we check for is the NLPID and a frame
+ * control field of UI, i.e. 0x03 followed
+ * by the NLPID.
+ */
+ b0 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO8473_CLNP);
+ b1 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO9542_ESIS);
+ b2 = gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | ISO10589_ISIS);
+ gen_or(b1, b2);
+ gen_or(b0, b2);
+ return b2;
+
+ default:
+ return gen_false();
+ }
+ /*NOTREACHED*/
+ break;
+
+ case DLT_MFR:
+ bpf_error("Multi-link Frame Relay link-layer type filtering not implemented");
+
+ case DLT_JUNIPER_MFR:
+ case DLT_JUNIPER_MLFR:
+ case DLT_JUNIPER_MLPPP:
+ case DLT_JUNIPER_ATM1:
+ case DLT_JUNIPER_ATM2:
+ case DLT_JUNIPER_PPPOE:
+ case DLT_JUNIPER_PPPOE_ATM:
+ case DLT_JUNIPER_GGSN:
+ case DLT_JUNIPER_ES:
+ case DLT_JUNIPER_MONITOR:
+ case DLT_JUNIPER_SERVICES:
+ case DLT_JUNIPER_ETHER:
+ case DLT_JUNIPER_PPP:
+ case DLT_JUNIPER_FRELAY:
+ case DLT_JUNIPER_CHDLC:
+ case DLT_JUNIPER_VP:
+ case DLT_JUNIPER_ST:
+ case DLT_JUNIPER_ISM:
+ /* just lets verify the magic number for now -
+ * on ATM we may have up to 6 different encapsulations on the wire
+ * and need a lot of heuristics to figure out that the payload
+ * might be;
+ *
+ * FIXME encapsulation specific BPF_ filters
+ */
+ return gen_mcmp(OR_LINK, 0, BPF_W, 0x4d474300, 0xffffff00); /* compare the magic number */
+
+ case DLT_LINUX_IRDA:
+ bpf_error("IrDA link-layer type filtering not implemented");
+
+ case DLT_DOCSIS:
+ bpf_error("DOCSIS link-layer type filtering not implemented");
+
+ case DLT_MTP2:
+ case DLT_MTP2_WITH_PHDR:
+ bpf_error("MTP2 link-layer type filtering not implemented");
+
+ case DLT_ERF:
+ bpf_error("ERF link-layer type filtering not implemented");
+
+#ifdef DLT_PFSYNC
+ case DLT_PFSYNC:
+ bpf_error("PFSYNC link-layer type filtering not implemented");
+#endif
+
+ case DLT_LINUX_LAPD:
+ bpf_error("LAPD link-layer type filtering not implemented");
+
+ case DLT_USB:
+ case DLT_USB_LINUX:
+ case DLT_USB_LINUX_MMAPPED:
+ bpf_error("USB link-layer type filtering not implemented");
+
+ case DLT_BLUETOOTH_HCI_H4:
+ case DLT_BLUETOOTH_HCI_H4_WITH_PHDR:
+ bpf_error("Bluetooth link-layer type filtering not implemented");
+
+ case DLT_CAN20B:
+ bpf_error("CAN20B link-layer type filtering not implemented");
+
+ case DLT_IEEE802_15_4:
+ case DLT_IEEE802_15_4_LINUX:
+ case DLT_IEEE802_15_4_NONASK_PHY:
+ bpf_error("IEEE 802.15.4 link-layer type filtering not implemented");
+
+ case DLT_IEEE802_16_MAC_CPS_RADIO:
+ bpf_error("IEEE 802.16 link-layer type filtering not implemented");
+
+ case DLT_SITA:
+ bpf_error("SITA link-layer type filtering not implemented");
+
+ case DLT_RAIF1:
+ bpf_error("RAIF1 link-layer type filtering not implemented");
+
+ case DLT_IPMB:
+ bpf_error("IPMB link-layer type filtering not implemented");
+
+ case DLT_AX25_KISS:
+ bpf_error("AX.25 link-layer type filtering not implemented");
+ }
+
+ /*
+ * All the types that have no encapsulation should either be
+ * handled as DLT_SLIP, DLT_SLIP_BSDOS, and DLT_RAW are, if
+ * all packets are IP packets, or should be handled in some
+ * special case, if none of them are (if some are and some
+ * aren't, the lack of encapsulation is a problem, as we'd
+ * have to find some other way of determining the packet type).
+ *
+ * Therefore, if "off_linktype" is -1, there's an error.
+ */
+ if (off_linktype == (u_int)-1)
+ abort();
+
+ /*
+ * Any type not handled above should always have an Ethernet
+ * type at an offset of "off_linktype".
+ */
+ return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
+}
+
+/*
+ * Check for an LLC SNAP packet with a given organization code and
+ * protocol type; we check the entire contents of the 802.2 LLC and
+ * snap headers, checking for DSAP and SSAP of SNAP and a control
+ * field of 0x03 in the LLC header, and for the specified organization
+ * code and protocol type in the SNAP header.
+ */
+static struct block *
+gen_snap(orgcode, ptype)
+ bpf_u_int32 orgcode;
+ bpf_u_int32 ptype;
+{
+ u_char snapblock[8];
+
+ snapblock[0] = LLCSAP_SNAP; /* DSAP = SNAP */
+ snapblock[1] = LLCSAP_SNAP; /* SSAP = SNAP */
+ snapblock[2] = 0x03; /* control = UI */
+ snapblock[3] = (orgcode >> 16); /* upper 8 bits of organization code */
+ snapblock[4] = (orgcode >> 8); /* middle 8 bits of organization code */
+ snapblock[5] = (orgcode >> 0); /* lower 8 bits of organization code */
+ snapblock[6] = (ptype >> 8); /* upper 8 bits of protocol type */
+ snapblock[7] = (ptype >> 0); /* lower 8 bits of protocol type */
+ return gen_bcmp(OR_MACPL, 0, 8, snapblock);
+}
+
+/*
+ * Generate code to match a particular packet type, for link-layer types
+ * using 802.2 LLC headers.
+ *
+ * This is *NOT* used for Ethernet; "gen_ether_linktype()" is used
+ * for that - it handles the D/I/X Ethernet vs. 802.3+802.2 issues.
+ *
+ * "proto" is an Ethernet type value, if > ETHERMTU, or an LLC SAP
+ * value, if <= ETHERMTU. We use that to determine whether to
+ * match the DSAP or both DSAP and LSAP or to check the OUI and
+ * protocol ID in a SNAP header.
+ */
+static struct block *
+gen_llc_linktype(proto)
+ int proto;
+{
+ /*
+ * XXX - handle token-ring variable-length header.
+ */
+ switch (proto) {
+
+ case LLCSAP_IP:
+ case LLCSAP_ISONS:
+ case LLCSAP_NETBEUI:
+ /*
+ * XXX - should we check both the DSAP and the
+ * SSAP, like this, or should we check just the
+ * DSAP, as we do for other types <= ETHERMTU
+ * (i.e., other SAP values)?
+ */
+ return gen_cmp(OR_MACPL, 0, BPF_H, (bpf_u_int32)
+ ((proto << 8) | proto));
+
+ case LLCSAP_IPX:
+ /*
+ * XXX - are there ever SNAP frames for IPX on
+ * non-Ethernet 802.x networks?
+ */
+ return gen_cmp(OR_MACPL, 0, BPF_B,
+ (bpf_int32)LLCSAP_IPX);
+
+ case ETHERTYPE_ATALK:
+ /*
+ * 802.2-encapsulated ETHERTYPE_ATALK packets are
+ * SNAP packets with an organization code of
+ * 0x080007 (Apple, for Appletalk) and a protocol
+ * type of ETHERTYPE_ATALK (Appletalk).
+ *
+ * XXX - check for an organization code of
+ * encapsulated Ethernet as well?
+ */
+ return gen_snap(0x080007, ETHERTYPE_ATALK);
+
+ default:
+ /*
+ * XXX - we don't have to check for IPX 802.3
+ * here, but should we check for the IPX Ethertype?
+ */
+ if (proto <= ETHERMTU) {
+ /*
+ * This is an LLC SAP value, so check
+ * the DSAP.
+ */
+ return gen_cmp(OR_MACPL, 0, BPF_B, (bpf_int32)proto);
+ } else {
+ /*
+ * This is an Ethernet type; we assume that it's
+ * unlikely that it'll appear in the right place
+ * at random, and therefore check only the
+ * location that would hold the Ethernet type
+ * in a SNAP frame with an organization code of
+ * 0x000000 (encapsulated Ethernet).
+ *
+ * XXX - if we were to check for the SNAP DSAP and
+ * LSAP, as per XXX, and were also to check for an
+ * organization code of 0x000000 (encapsulated
+ * Ethernet), we'd do
+ *
+ * return gen_snap(0x000000, proto);
+ *
+ * here; for now, we don't, as per the above.
+ * I don't know whether it's worth the extra CPU
+ * time to do the right check or not.
+ */
+ return gen_cmp(OR_MACPL, 6, BPF_H, (bpf_int32)proto);
+ }
+ }
+}
+
+static struct block *
+gen_hostop(addr, mask, dir, proto, src_off, dst_off)
+ bpf_u_int32 addr;
+ bpf_u_int32 mask;
+ int dir, proto;
+ u_int src_off, dst_off;
+{
+ struct block *b0, *b1;
+ u_int offset;
+
+ switch (dir) {
+
+ case Q_SRC:
+ offset = src_off;
+ break;
+
+ case Q_DST:
+ offset = dst_off;
+ break;
+
+ case Q_AND:
+ b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
+ b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_OR:
+ case Q_DEFAULT:
+ b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
+ b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
+ gen_or(b0, b1);
+ return b1;
+
+ default:
+ abort();
+ }
+ b0 = gen_linktype(proto);
+ b1 = gen_mcmp(OR_NET, offset, BPF_W, (bpf_int32)addr, mask);
+ gen_and(b0, b1);
+ return b1;
+}
+
+#ifdef INET6
+static struct block *
+gen_hostop6(addr, mask, dir, proto, src_off, dst_off)
+ struct in6_addr *addr;
+ struct in6_addr *mask;
+ int dir, proto;
+ u_int src_off, dst_off;
+{
+ struct block *b0, *b1;
+ u_int offset;
+ u_int32_t *a, *m;
+
+ switch (dir) {
+
+ case Q_SRC:
+ offset = src_off;
+ break;
+
+ case Q_DST:
+ offset = dst_off;
+ break;
+
+ case Q_AND:
+ b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off);
+ b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_OR:
+ case Q_DEFAULT:
+ b0 = gen_hostop6(addr, mask, Q_SRC, proto, src_off, dst_off);
+ b1 = gen_hostop6(addr, mask, Q_DST, proto, src_off, dst_off);
+ gen_or(b0, b1);
+ return b1;
+
+ default:
+ abort();
+ }
+ /* this order is important */
+ a = (u_int32_t *)addr;
+ m = (u_int32_t *)mask;
+ b1 = gen_mcmp(OR_NET, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3]));
+ b0 = gen_mcmp(OR_NET, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2]));
+ gen_and(b0, b1);
+ b0 = gen_mcmp(OR_NET, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1]));
+ gen_and(b0, b1);
+ b0 = gen_mcmp(OR_NET, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0]));
+ gen_and(b0, b1);
+ b0 = gen_linktype(proto);
+ gen_and(b0, b1);
+ return b1;
+}
+#endif /*INET6*/
+
+static struct block *
+gen_ehostop(eaddr, dir)
+ register const u_char *eaddr;
+ register int dir;
+{
+ register struct block *b0, *b1;
+
+ switch (dir) {
+ case Q_SRC:
+ return gen_bcmp(OR_LINK, off_mac + 6, 6, eaddr);
+
+ case Q_DST:
+ return gen_bcmp(OR_LINK, off_mac + 0, 6, eaddr);
+
+ case Q_AND:
+ b0 = gen_ehostop(eaddr, Q_SRC);
+ b1 = gen_ehostop(eaddr, Q_DST);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_DEFAULT:
+ case Q_OR:
+ b0 = gen_ehostop(eaddr, Q_SRC);
+ b1 = gen_ehostop(eaddr, Q_DST);
+ gen_or(b0, b1);
+ return b1;
+ }
+ abort();
+ /* NOTREACHED */
+}
+
+/*
+ * Like gen_ehostop, but for DLT_FDDI
+ */
+static struct block *
+gen_fhostop(eaddr, dir)
+ register const u_char *eaddr;
+ register int dir;
+{
+ struct block *b0, *b1;
+
+ switch (dir) {
+ case Q_SRC:
+#ifdef PCAP_FDDIPAD
+ return gen_bcmp(OR_LINK, 6 + 1 + pcap_fddipad, 6, eaddr);
+#else
+ return gen_bcmp(OR_LINK, 6 + 1, 6, eaddr);
+#endif
+
+ case Q_DST:
+#ifdef PCAP_FDDIPAD
+ return gen_bcmp(OR_LINK, 0 + 1 + pcap_fddipad, 6, eaddr);
+#else
+ return gen_bcmp(OR_LINK, 0 + 1, 6, eaddr);
+#endif
+
+ case Q_AND:
+ b0 = gen_fhostop(eaddr, Q_SRC);
+ b1 = gen_fhostop(eaddr, Q_DST);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_DEFAULT:
+ case Q_OR:
+ b0 = gen_fhostop(eaddr, Q_SRC);
+ b1 = gen_fhostop(eaddr, Q_DST);
+ gen_or(b0, b1);
+ return b1;
+ }
+ abort();
+ /* NOTREACHED */
+}
+
+/*
+ * Like gen_ehostop, but for DLT_IEEE802 (Token Ring)
+ */
+static struct block *
+gen_thostop(eaddr, dir)
+ register const u_char *eaddr;
+ register int dir;
+{
+ register struct block *b0, *b1;
+
+ switch (dir) {
+ case Q_SRC:
+ return gen_bcmp(OR_LINK, 8, 6, eaddr);
+
+ case Q_DST:
+ return gen_bcmp(OR_LINK, 2, 6, eaddr);
+
+ case Q_AND:
+ b0 = gen_thostop(eaddr, Q_SRC);
+ b1 = gen_thostop(eaddr, Q_DST);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_DEFAULT:
+ case Q_OR:
+ b0 = gen_thostop(eaddr, Q_SRC);
+ b1 = gen_thostop(eaddr, Q_DST);
+ gen_or(b0, b1);
+ return b1;
+ }
+ abort();
+ /* NOTREACHED */
+}
+
+/*
+ * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN) and
+ * various 802.11 + radio headers.
+ */
+static struct block *
+gen_wlanhostop(eaddr, dir)
+ register const u_char *eaddr;
+ register int dir;
+{
+ register struct block *b0, *b1, *b2;
+ register struct slist *s;
+
+#ifdef ENABLE_WLAN_FILTERING_PATCH
+ /*
+ * TODO GV 20070613
+ * We need to disable the optimizer because the optimizer is buggy
+ * and wipes out some LD instructions generated by the below
+ * code to validate the Frame Control bits
+ */
+ no_optimize = 1;
+#endif /* ENABLE_WLAN_FILTERING_PATCH */
+
+ switch (dir) {
+ case Q_SRC:
+ /*
+ * Oh, yuk.
+ *
+ * For control frames, there is no SA.
+ *
+ * For management frames, SA is at an
+ * offset of 10 from the beginning of
+ * the packet.
+ *
+ * For data frames, SA is at an offset
+ * of 10 from the beginning of the packet
+ * if From DS is clear, at an offset of
+ * 16 from the beginning of the packet
+ * if From DS is set and To DS is clear,
+ * and an offset of 24 from the beginning
+ * of the packet if From DS is set and To DS
+ * is set.
+ */
+
+ /*
+ * Generate the tests to be done for data frames
+ * with From DS set.
+ *
+ * First, check for To DS set, i.e. check "link[1] & 0x01".
+ */
+ s = gen_load_a(OR_LINK, 1, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x01; /* To DS */
+ b1->stmts = s;
+
+ /*
+ * If To DS is set, the SA is at 24.
+ */
+ b0 = gen_bcmp(OR_LINK, 24, 6, eaddr);
+ gen_and(b1, b0);
+
+ /*
+ * Now, check for To DS not set, i.e. check
+ * "!(link[1] & 0x01)".
+ */
+ s = gen_load_a(OR_LINK, 1, BPF_B);
+ b2 = new_block(JMP(BPF_JSET));
+ b2->s.k = 0x01; /* To DS */
+ b2->stmts = s;
+ gen_not(b2);
+
+ /*
+ * If To DS is not set, the SA is at 16.
+ */
+ b1 = gen_bcmp(OR_LINK, 16, 6, eaddr);
+ gen_and(b2, b1);
+
+ /*
+ * Now OR together the last two checks. That gives
+ * the complete set of checks for data frames with
+ * From DS set.
+ */
+ gen_or(b1, b0);
+
+ /*
+ * Now check for From DS being set, and AND that with
+ * the ORed-together checks.
+ */
+ s = gen_load_a(OR_LINK, 1, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x02; /* From DS */
+ b1->stmts = s;
+ gen_and(b1, b0);
+
+ /*
+ * Now check for data frames with From DS not set.
+ */
+ s = gen_load_a(OR_LINK, 1, BPF_B);
+ b2 = new_block(JMP(BPF_JSET));
+ b2->s.k = 0x02; /* From DS */
+ b2->stmts = s;
+ gen_not(b2);
+
+ /*
+ * If From DS isn't set, the SA is at 10.
+ */
+ b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
+ gen_and(b2, b1);
+
+ /*
+ * Now OR together the checks for data frames with
+ * From DS not set and for data frames with From DS
+ * set; that gives the checks done for data frames.
+ */
+ gen_or(b1, b0);
+
+ /*
+ * Now check for a data frame.
+ * I.e, check "link[0] & 0x08".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x08;
+ b1->stmts = s;
+
+ /*
+ * AND that with the checks done for data frames.
+ */
+ gen_and(b1, b0);
+
+ /*
+ * If the high-order bit of the type value is 0, this
+ * is a management frame.
+ * I.e, check "!(link[0] & 0x08)".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b2 = new_block(JMP(BPF_JSET));
+ b2->s.k = 0x08;
+ b2->stmts = s;
+ gen_not(b2);
+
+ /*
+ * For management frames, the SA is at 10.
+ */
+ b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
+ gen_and(b2, b1);
+
+ /*
+ * OR that with the checks done for data frames.
+ * That gives the checks done for management and
+ * data frames.
+ */
+ gen_or(b1, b0);
+
+ /*
+ * If the low-order bit of the type value is 1,
+ * this is either a control frame or a frame
+ * with a reserved type, and thus not a
+ * frame with an SA.
+ *
+ * I.e., check "!(link[0] & 0x04)".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x04;
+ b1->stmts = s;
+ gen_not(b1);
+
+ /*
+ * AND that with the checks for data and management
+ * frames.
+ */
+ gen_and(b1, b0);
+ return b0;
+
+ case Q_DST:
+ /*
+ * Oh, yuk.
+ *
+ * For control frames, there is no DA.
+ *
+ * For management frames, DA is at an
+ * offset of 4 from the beginning of
+ * the packet.
+ *
+ * For data frames, DA is at an offset
+ * of 4 from the beginning of the packet
+ * if To DS is clear and at an offset of
+ * 16 from the beginning of the packet
+ * if To DS is set.
+ */
+
+ /*
+ * Generate the tests to be done for data frames.
+ *
+ * First, check for To DS set, i.e. "link[1] & 0x01".
+ */
+ s = gen_load_a(OR_LINK, 1, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x01; /* To DS */
+ b1->stmts = s;
+
+ /*
+ * If To DS is set, the DA is at 16.
+ */
+ b0 = gen_bcmp(OR_LINK, 16, 6, eaddr);
+ gen_and(b1, b0);
+
+ /*
+ * Now, check for To DS not set, i.e. check
+ * "!(link[1] & 0x01)".
+ */
+ s = gen_load_a(OR_LINK, 1, BPF_B);
+ b2 = new_block(JMP(BPF_JSET));
+ b2->s.k = 0x01; /* To DS */
+ b2->stmts = s;
+ gen_not(b2);
+
+ /*
+ * If To DS is not set, the DA is at 4.
+ */
+ b1 = gen_bcmp(OR_LINK, 4, 6, eaddr);
+ gen_and(b2, b1);
+
+ /*
+ * Now OR together the last two checks. That gives
+ * the complete set of checks for data frames.
+ */
+ gen_or(b1, b0);
+
+ /*
+ * Now check for a data frame.
+ * I.e, check "link[0] & 0x08".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x08;
+ b1->stmts = s;
+
+ /*
+ * AND that with the checks done for data frames.
+ */
+ gen_and(b1, b0);
+
+ /*
+ * If the high-order bit of the type value is 0, this
+ * is a management frame.
+ * I.e, check "!(link[0] & 0x08)".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b2 = new_block(JMP(BPF_JSET));
+ b2->s.k = 0x08;
+ b2->stmts = s;
+ gen_not(b2);
+
+ /*
+ * For management frames, the DA is at 4.
+ */
+ b1 = gen_bcmp(OR_LINK, 4, 6, eaddr);
+ gen_and(b2, b1);
+
+ /*
+ * OR that with the checks done for data frames.
+ * That gives the checks done for management and
+ * data frames.
+ */
+ gen_or(b1, b0);
+
+ /*
+ * If the low-order bit of the type value is 1,
+ * this is either a control frame or a frame
+ * with a reserved type, and thus not a
+ * frame with an SA.
+ *
+ * I.e., check "!(link[0] & 0x04)".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x04;
+ b1->stmts = s;
+ gen_not(b1);
+
+ /*
+ * AND that with the checks for data and management
+ * frames.
+ */
+ gen_and(b1, b0);
+ return b0;
+
+ /*
+ * XXX - add RA, TA, and BSSID keywords?
+ */
+ case Q_ADDR1:
+ return (gen_bcmp(OR_LINK, 4, 6, eaddr));
+
+ case Q_ADDR2:
+ /*
+ * Not present in CTS or ACK control frames.
+ */
+ b0 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
+ IEEE80211_FC0_TYPE_MASK);
+ gen_not(b0);
+ b1 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS,
+ IEEE80211_FC0_SUBTYPE_MASK);
+ gen_not(b1);
+ b2 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK,
+ IEEE80211_FC0_SUBTYPE_MASK);
+ gen_not(b2);
+ gen_and(b1, b2);
+ gen_or(b0, b2);
+ b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
+ gen_and(b2, b1);
+ return b1;
+
+ case Q_ADDR3:
+ /*
+ * Not present in control frames.
+ */
+ b0 = gen_mcmp(OR_LINK, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
+ IEEE80211_FC0_TYPE_MASK);
+ gen_not(b0);
+ b1 = gen_bcmp(OR_LINK, 16, 6, eaddr);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_ADDR4:
+ /*
+ * Present only if the direction mask has both "From DS"
+ * and "To DS" set. Neither control frames nor management
+ * frames should have both of those set, so we don't
+ * check the frame type.
+ */
+ b0 = gen_mcmp(OR_LINK, 1, BPF_B,
+ IEEE80211_FC1_DIR_DSTODS, IEEE80211_FC1_DIR_MASK);
+ b1 = gen_bcmp(OR_LINK, 24, 6, eaddr);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_AND:
+ b0 = gen_wlanhostop(eaddr, Q_SRC);
+ b1 = gen_wlanhostop(eaddr, Q_DST);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_DEFAULT:
+ case Q_OR:
+ b0 = gen_wlanhostop(eaddr, Q_SRC);
+ b1 = gen_wlanhostop(eaddr, Q_DST);
+ gen_or(b0, b1);
+ return b1;
+ }
+ abort();
+ /* NOTREACHED */
+}
+
+/*
+ * Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel.
+ * (We assume that the addresses are IEEE 48-bit MAC addresses,
+ * as the RFC states.)
+ */
+static struct block *
+gen_ipfchostop(eaddr, dir)
+ register const u_char *eaddr;
+ register int dir;
+{
+ register struct block *b0, *b1;
+
+ switch (dir) {
+ case Q_SRC:
+ return gen_bcmp(OR_LINK, 10, 6, eaddr);
+
+ case Q_DST:
+ return gen_bcmp(OR_LINK, 2, 6, eaddr);
+
+ case Q_AND:
+ b0 = gen_ipfchostop(eaddr, Q_SRC);
+ b1 = gen_ipfchostop(eaddr, Q_DST);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_DEFAULT:
+ case Q_OR:
+ b0 = gen_ipfchostop(eaddr, Q_SRC);
+ b1 = gen_ipfchostop(eaddr, Q_DST);
+ gen_or(b0, b1);
+ return b1;
+ }
+ abort();
+ /* NOTREACHED */
+}
+
+/*
+ * This is quite tricky because there may be pad bytes in front of the
+ * DECNET header, and then there are two possible data packet formats that
+ * carry both src and dst addresses, plus 5 packet types in a format that
+ * carries only the src node, plus 2 types that use a different format and
+ * also carry just the src node.
+ *
+ * Yuck.
+ *
+ * Instead of doing those all right, we just look for data packets with
+ * 0 or 1 bytes of padding. If you want to look at other packets, that
+ * will require a lot more hacking.
+ *
+ * To add support for filtering on DECNET "areas" (network numbers)
+ * one would want to add a "mask" argument to this routine. That would
+ * make the filter even more inefficient, although one could be clever
+ * and not generate masking instructions if the mask is 0xFFFF.
+ */
+static struct block *
+gen_dnhostop(addr, dir)
+ bpf_u_int32 addr;
+ int dir;
+{
+ struct block *b0, *b1, *b2, *tmp;
+ u_int offset_lh; /* offset if long header is received */
+ u_int offset_sh; /* offset if short header is received */
+
+ switch (dir) {
+
+ case Q_DST:
+ offset_sh = 1; /* follows flags */
+ offset_lh = 7; /* flgs,darea,dsubarea,HIORD */
+ break;
+
+ case Q_SRC:
+ offset_sh = 3; /* follows flags, dstnode */
+ offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */
+ break;
+
+ case Q_AND:
+ /* Inefficient because we do our Calvinball dance twice */
+ b0 = gen_dnhostop(addr, Q_SRC);
+ b1 = gen_dnhostop(addr, Q_DST);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_OR:
+ case Q_DEFAULT:
+ /* Inefficient because we do our Calvinball dance twice */
+ b0 = gen_dnhostop(addr, Q_SRC);
+ b1 = gen_dnhostop(addr, Q_DST);
+ gen_or(b0, b1);
+ return b1;
+
+ case Q_ISO:
+ bpf_error("ISO host filtering not implemented");
+
+ default:
+ abort();
+ }
+ b0 = gen_linktype(ETHERTYPE_DN);
+ /* Check for pad = 1, long header case */
+ tmp = gen_mcmp(OR_NET, 2, BPF_H,
+ (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF));
+ b1 = gen_cmp(OR_NET, 2 + 1 + offset_lh,
+ BPF_H, (bpf_int32)ntohs((u_short)addr));
+ gen_and(tmp, b1);
+ /* Check for pad = 0, long header case */
+ tmp = gen_mcmp(OR_NET, 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7);
+ b2 = gen_cmp(OR_NET, 2 + offset_lh, BPF_H, (bpf_int32)ntohs((u_short)addr));
+ gen_and(tmp, b2);
+ gen_or(b2, b1);
+ /* Check for pad = 1, short header case */
+ tmp = gen_mcmp(OR_NET, 2, BPF_H,
+ (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF));
+ b2 = gen_cmp(OR_NET, 2 + 1 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
+ gen_and(tmp, b2);
+ gen_or(b2, b1);
+ /* Check for pad = 0, short header case */
+ tmp = gen_mcmp(OR_NET, 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7);
+ b2 = gen_cmp(OR_NET, 2 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
+ gen_and(tmp, b2);
+ gen_or(b2, b1);
+
+ /* Combine with test for linktype */
+ gen_and(b0, b1);
+ return b1;
+}
+
+/*
+ * Generate a check for IPv4 or IPv6 for MPLS-encapsulated packets;
+ * test the bottom-of-stack bit, and then check the version number
+ * field in the IP header.
+ */
+static struct block *
+gen_mpls_linktype(proto)
+ int proto;
+{
+ struct block *b0, *b1;
+
+ switch (proto) {
+
+ case Q_IP:
+ /* match the bottom-of-stack bit */
+ b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01);
+ /* match the IPv4 version number */
+ b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x40, 0xf0);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_IPV6:
+ /* match the bottom-of-stack bit */
+ b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01);
+ /* match the IPv4 version number */
+ b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x60, 0xf0);
+ gen_and(b0, b1);
+ return b1;
+
+ default:
+ abort();
+ }
+}
+
+static struct block *
+gen_host(addr, mask, proto, dir, type)
+ bpf_u_int32 addr;
+ bpf_u_int32 mask;
+ int proto;
+ int dir;
+ int type;
+{
+ struct block *b0, *b1;
+ const char *typestr;
+
+ if (type == Q_NET)
+ typestr = "net";
+ else
+ typestr = "host";
+
+ switch (proto) {
+
+ case Q_DEFAULT:
+ b0 = gen_host(addr, mask, Q_IP, dir, type);
+ /*
+ * Only check for non-IPv4 addresses if we're not
+ * checking MPLS-encapsulated packets.
+ */
+ if (label_stack_depth == 0) {
+ b1 = gen_host(addr, mask, Q_ARP, dir, type);
+ gen_or(b0, b1);
+ b0 = gen_host(addr, mask, Q_RARP, dir, type);
+ gen_or(b1, b0);
+ }
+ return b0;
+
+ case Q_IP:
+ return gen_hostop(addr, mask, dir, ETHERTYPE_IP, 12, 16);
+
+ case Q_RARP:
+ return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP, 14, 24);
+
+ case Q_ARP:
+ return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 14, 24);
+
+ case Q_TCP:
+ bpf_error("'tcp' modifier applied to %s", typestr);
+
+ case Q_SCTP:
+ bpf_error("'sctp' modifier applied to %s", typestr);
+
+ case Q_UDP:
+ bpf_error("'udp' modifier applied to %s", typestr);
+
+ case Q_ICMP:
+ bpf_error("'icmp' modifier applied to %s", typestr);
+
+ case Q_IGMP:
+ bpf_error("'igmp' modifier applied to %s", typestr);
+
+ case Q_IGRP:
+ bpf_error("'igrp' modifier applied to %s", typestr);
+
+ case Q_PIM:
+ bpf_error("'pim' modifier applied to %s", typestr);
+
+ case Q_VRRP:
+ bpf_error("'vrrp' modifier applied to %s", typestr);
+
+ case Q_ATALK:
+ bpf_error("ATALK host filtering not implemented");
+
+ case Q_AARP:
+ bpf_error("AARP host filtering not implemented");
+
+ case Q_DECNET:
+ return gen_dnhostop(addr, dir);
+
+ case Q_SCA:
+ bpf_error("SCA host filtering not implemented");
+
+ case Q_LAT:
+ bpf_error("LAT host filtering not implemented");
+
+ case Q_MOPDL:
+ bpf_error("MOPDL host filtering not implemented");
+
+ case Q_MOPRC:
+ bpf_error("MOPRC host filtering not implemented");
+
+#ifdef INET6
+ case Q_IPV6:
+ bpf_error("'ip6' modifier applied to ip host");
+
+ case Q_ICMPV6:
+ bpf_error("'icmp6' modifier applied to %s", typestr);
+#endif /* INET6 */
+
+ case Q_AH:
+ bpf_error("'ah' modifier applied to %s", typestr);
+
+ case Q_ESP:
+ bpf_error("'esp' modifier applied to %s", typestr);
+
+ case Q_ISO:
+ bpf_error("ISO host filtering not implemented");
+
+ case Q_ESIS:
+ bpf_error("'esis' modifier applied to %s", typestr);
+
+ case Q_ISIS:
+ bpf_error("'isis' modifier applied to %s", typestr);
+
+ case Q_CLNP:
+ bpf_error("'clnp' modifier applied to %s", typestr);
+
+ case Q_STP:
+ bpf_error("'stp' modifier applied to %s", typestr);
+
+ case Q_IPX:
+ bpf_error("IPX host filtering not implemented");
+
+ case Q_NETBEUI:
+ bpf_error("'netbeui' modifier applied to %s", typestr);
+
+ case Q_RADIO:
+ bpf_error("'radio' modifier applied to %s", typestr);
+
+ default:
+ abort();
+ }
+ /* NOTREACHED */
+}
+
+#ifdef INET6
+static struct block *
+gen_host6(addr, mask, proto, dir, type)
+ struct in6_addr *addr;
+ struct in6_addr *mask;
+ int proto;
+ int dir;
+ int type;
+{
+ const char *typestr;
+
+ if (type == Q_NET)
+ typestr = "net";
+ else
+ typestr = "host";
+
+ switch (proto) {
+
+ case Q_DEFAULT:
+ return gen_host6(addr, mask, Q_IPV6, dir, type);
+
+ case Q_IP:
+ bpf_error("'ip' modifier applied to ip6 %s", typestr);
+
+ case Q_RARP:
+ bpf_error("'rarp' modifier applied to ip6 %s", typestr);
+
+ case Q_ARP:
+ bpf_error("'arp' modifier applied to ip6 %s", typestr);
+
+ case Q_SCTP:
+ bpf_error("'sctp' modifier applied to %s", typestr);
+
+ case Q_TCP:
+ bpf_error("'tcp' modifier applied to %s", typestr);
+
+ case Q_UDP:
+ bpf_error("'udp' modifier applied to %s", typestr);
+
+ case Q_ICMP:
+ bpf_error("'icmp' modifier applied to %s", typestr);
+
+ case Q_IGMP:
+ bpf_error("'igmp' modifier applied to %s", typestr);
+
+ case Q_IGRP:
+ bpf_error("'igrp' modifier applied to %s", typestr);
+
+ case Q_PIM:
+ bpf_error("'pim' modifier applied to %s", typestr);
+
+ case Q_VRRP:
+ bpf_error("'vrrp' modifier applied to %s", typestr);
+
+ case Q_ATALK:
+ bpf_error("ATALK host filtering not implemented");
+
+ case Q_AARP:
+ bpf_error("AARP host filtering not implemented");
+
+ case Q_DECNET:
+ bpf_error("'decnet' modifier applied to ip6 %s", typestr);
+
+ case Q_SCA:
+ bpf_error("SCA host filtering not implemented");
+
+ case Q_LAT:
+ bpf_error("LAT host filtering not implemented");
+
+ case Q_MOPDL:
+ bpf_error("MOPDL host filtering not implemented");
+
+ case Q_MOPRC:
+ bpf_error("MOPRC host filtering not implemented");
+
+ case Q_IPV6:
+ return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 8, 24);
+
+ case Q_ICMPV6:
+ bpf_error("'icmp6' modifier applied to %s", typestr);
+
+ case Q_AH:
+ bpf_error("'ah' modifier applied to %s", typestr);
+
+ case Q_ESP:
+ bpf_error("'esp' modifier applied to %s", typestr);
+
+ case Q_ISO:
+ bpf_error("ISO host filtering not implemented");
+
+ case Q_ESIS:
+ bpf_error("'esis' modifier applied to %s", typestr);
+
+ case Q_ISIS:
+ bpf_error("'isis' modifier applied to %s", typestr);
+
+ case Q_CLNP:
+ bpf_error("'clnp' modifier applied to %s", typestr);
+
+ case Q_STP:
+ bpf_error("'stp' modifier applied to %s", typestr);
+
+ case Q_IPX:
+ bpf_error("IPX host filtering not implemented");
+
+ case Q_NETBEUI:
+ bpf_error("'netbeui' modifier applied to %s", typestr);
+
+ case Q_RADIO:
+ bpf_error("'radio' modifier applied to %s", typestr);
+
+ default:
+ abort();
+ }
+ /* NOTREACHED */
+}
+#endif /*INET6*/
+
+#ifndef INET6
+static struct block *
+gen_gateway(eaddr, alist, proto, dir)
+ const u_char *eaddr;
+ bpf_u_int32 **alist;
+ int proto;
+ int dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ if (dir != 0)
+ bpf_error("direction applied to 'gateway'");
+
+ switch (proto) {
+ case Q_DEFAULT:
+ case Q_IP:
+ case Q_ARP:
+ case Q_RARP:
+ switch (linktype) {
+ case DLT_EN10MB:
+ b0 = gen_ehostop(eaddr, Q_OR);
+ break;
+ case DLT_FDDI:
+ b0 = gen_fhostop(eaddr, Q_OR);
+ break;
+ case DLT_IEEE802:
+ b0 = gen_thostop(eaddr, Q_OR);
+ break;
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
+ b0 = gen_wlanhostop(eaddr, Q_OR);
+ break;
+ case DLT_SUNATM:
+ if (is_lane) {
+ /*
+ * Check that the packet doesn't begin with an
+ * LE Control marker. (We've already generated
+ * a test for LANE.)
+ */
+ b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS,
+ BPF_H, 0xFF00);
+ gen_not(b1);
+
+ /*
+ * Now check the MAC address.
+ */
+ b0 = gen_ehostop(eaddr, Q_OR);
+ gen_and(b1, b0);
+ }
+ break;
+ case DLT_IP_OVER_FC:
+ b0 = gen_ipfchostop(eaddr, Q_OR);
+ break;
+ default:
+ bpf_error(
+ "'gateway' supported only on ethernet/FDDI/token ring/802.11/Fibre Channel");
+ }
+ b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR, Q_HOST);
+ while (*alist) {
+ tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR,
+ Q_HOST);
+ gen_or(b1, tmp);
+ b1 = tmp;
+ }
+ gen_not(b1);
+ gen_and(b0, b1);
+ return b1;
+ }
+ bpf_error("illegal modifier of 'gateway'");
+ /* NOTREACHED */
+}
+#endif
+
+struct block *
+gen_proto_abbrev(proto)
+ int proto;
+{
+ struct block *b0;
+ struct block *b1;
+
+ switch (proto) {
+
+ case Q_SCTP:
+ b1 = gen_proto(IPPROTO_SCTP, Q_IP, Q_DEFAULT);
+#ifdef INET6
+ b0 = gen_proto(IPPROTO_SCTP, Q_IPV6, Q_DEFAULT);
+ gen_or(b0, b1);
+#endif
+ break;
+
+ case Q_TCP:
+ b1 = gen_proto(IPPROTO_TCP, Q_IP, Q_DEFAULT);
+#ifdef INET6
+ b0 = gen_proto(IPPROTO_TCP, Q_IPV6, Q_DEFAULT);
+ gen_or(b0, b1);
+#endif
+ break;
+
+ case Q_UDP:
+ b1 = gen_proto(IPPROTO_UDP, Q_IP, Q_DEFAULT);
+#ifdef INET6
+ b0 = gen_proto(IPPROTO_UDP, Q_IPV6, Q_DEFAULT);
+ gen_or(b0, b1);
+#endif
+ break;
+
+ case Q_ICMP:
+ b1 = gen_proto(IPPROTO_ICMP, Q_IP, Q_DEFAULT);
+ break;
+
+#ifndef IPPROTO_IGMP
+#define IPPROTO_IGMP 2
+#endif
+
+ case Q_IGMP:
+ b1 = gen_proto(IPPROTO_IGMP, Q_IP, Q_DEFAULT);
+ break;
+
+#ifndef IPPROTO_IGRP
+#define IPPROTO_IGRP 9
+#endif
+ case Q_IGRP:
+ b1 = gen_proto(IPPROTO_IGRP, Q_IP, Q_DEFAULT);
+ break;
+
+#ifndef IPPROTO_PIM
+#define IPPROTO_PIM 103
+#endif
+
+ case Q_PIM:
+ b1 = gen_proto(IPPROTO_PIM, Q_IP, Q_DEFAULT);
+#ifdef INET6
+ b0 = gen_proto(IPPROTO_PIM, Q_IPV6, Q_DEFAULT);
+ gen_or(b0, b1);
+#endif
+ break;
+
+#ifndef IPPROTO_VRRP
+#define IPPROTO_VRRP 112
+#endif
+
+ case Q_VRRP:
+ b1 = gen_proto(IPPROTO_VRRP, Q_IP, Q_DEFAULT);
+ break;
+
+ case Q_IP:
+ b1 = gen_linktype(ETHERTYPE_IP);
+ break;
+
+ case Q_ARP:
+ b1 = gen_linktype(ETHERTYPE_ARP);
+ break;
+
+ case Q_RARP:
+ b1 = gen_linktype(ETHERTYPE_REVARP);
+ break;
+
+ case Q_LINK:
+ bpf_error("link layer applied in wrong context");
+
+ case Q_ATALK:
+ b1 = gen_linktype(ETHERTYPE_ATALK);
+ break;
+
+ case Q_AARP:
+ b1 = gen_linktype(ETHERTYPE_AARP);
+ break;
+
+ case Q_DECNET:
+ b1 = gen_linktype(ETHERTYPE_DN);
+ break;
+
+ case Q_SCA:
+ b1 = gen_linktype(ETHERTYPE_SCA);
+ break;
+
+ case Q_LAT:
+ b1 = gen_linktype(ETHERTYPE_LAT);
+ break;
+
+ case Q_MOPDL:
+ b1 = gen_linktype(ETHERTYPE_MOPDL);
+ break;
+
+ case Q_MOPRC:
+ b1 = gen_linktype(ETHERTYPE_MOPRC);
+ break;
+
+#ifdef INET6
+ case Q_IPV6:
+ b1 = gen_linktype(ETHERTYPE_IPV6);
+ break;
+
+#ifndef IPPROTO_ICMPV6
+#define IPPROTO_ICMPV6 58
+#endif
+ case Q_ICMPV6:
+ b1 = gen_proto(IPPROTO_ICMPV6, Q_IPV6, Q_DEFAULT);
+ break;
+#endif /* INET6 */
+
+#ifndef IPPROTO_AH
+#define IPPROTO_AH 51
+#endif
+ case Q_AH:
+ b1 = gen_proto(IPPROTO_AH, Q_IP, Q_DEFAULT);
+#ifdef INET6
+ b0 = gen_proto(IPPROTO_AH, Q_IPV6, Q_DEFAULT);
+ gen_or(b0, b1);
+#endif
+ break;
+
+#ifndef IPPROTO_ESP
+#define IPPROTO_ESP 50
+#endif
+ case Q_ESP:
+ b1 = gen_proto(IPPROTO_ESP, Q_IP, Q_DEFAULT);
+#ifdef INET6
+ b0 = gen_proto(IPPROTO_ESP, Q_IPV6, Q_DEFAULT);
+ gen_or(b0, b1);
+#endif
+ break;
+
+ case Q_ISO:
+ b1 = gen_linktype(LLCSAP_ISONS);
+ break;
+
+ case Q_ESIS:
+ b1 = gen_proto(ISO9542_ESIS, Q_ISO, Q_DEFAULT);
+ break;
+
+ case Q_ISIS:
+ b1 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT);
+ break;
+
+ case Q_ISIS_L1: /* all IS-IS Level1 PDU-Types */
+ b0 = gen_proto(ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
+ b1 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ break;
+
+ case Q_ISIS_L2: /* all IS-IS Level2 PDU-Types */
+ b0 = gen_proto(ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
+ b1 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT); /* FIXME extract the circuit-type bits */
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ break;
+
+ case Q_ISIS_IIH: /* all IS-IS Hello PDU-Types */
+ b0 = gen_proto(ISIS_L1_LAN_IIH, Q_ISIS, Q_DEFAULT);
+ b1 = gen_proto(ISIS_L2_LAN_IIH, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_PTP_IIH, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ break;
+
+ case Q_ISIS_LSP:
+ b0 = gen_proto(ISIS_L1_LSP, Q_ISIS, Q_DEFAULT);
+ b1 = gen_proto(ISIS_L2_LSP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ break;
+
+ case Q_ISIS_SNP:
+ b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
+ b1 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ b0 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ break;
+
+ case Q_ISIS_CSNP:
+ b0 = gen_proto(ISIS_L1_CSNP, Q_ISIS, Q_DEFAULT);
+ b1 = gen_proto(ISIS_L2_CSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ break;
+
+ case Q_ISIS_PSNP:
+ b0 = gen_proto(ISIS_L1_PSNP, Q_ISIS, Q_DEFAULT);
+ b1 = gen_proto(ISIS_L2_PSNP, Q_ISIS, Q_DEFAULT);
+ gen_or(b0, b1);
+ break;
+
+ case Q_CLNP:
+ b1 = gen_proto(ISO8473_CLNP, Q_ISO, Q_DEFAULT);
+ break;
+
+ case Q_STP:
+ b1 = gen_linktype(LLCSAP_8021D);
+ break;
+
+ case Q_IPX:
+ b1 = gen_linktype(LLCSAP_IPX);
+ break;
+
+ case Q_NETBEUI:
+ b1 = gen_linktype(LLCSAP_NETBEUI);
+ break;
+
+ case Q_RADIO:
+ bpf_error("'radio' is not a valid protocol type");
+
+ default:
+ abort();
+ }
+ return b1;
+}
+
+static struct block *
+gen_ipfrag()
+{
+ struct slist *s;
+ struct block *b;
+
+ /* not ip frag */
+ s = gen_load_a(OR_NET, 6, BPF_H);
+ b = new_block(JMP(BPF_JSET));
+ b->s.k = 0x1fff;
+ b->stmts = s;
+ gen_not(b);
+
+ return b;
+}
+
+/*
+ * Generate a comparison to a port value in the transport-layer header
+ * at the specified offset from the beginning of that header.
+ *
+ * XXX - this handles a variable-length prefix preceding the link-layer
+ * header, such as the radiotap or AVS radio prefix, but doesn't handle
+ * variable-length link-layer headers (such as Token Ring or 802.11
+ * headers).
+ */
+static struct block *
+gen_portatom(off, v)
+ int off;
+ bpf_int32 v;
+{
+ return gen_cmp(OR_TRAN_IPV4, off, BPF_H, v);
+}
+
+#ifdef INET6
+static struct block *
+gen_portatom6(off, v)
+ int off;
+ bpf_int32 v;
+{
+ return gen_cmp(OR_TRAN_IPV6, off, BPF_H, v);
+}
+#endif/*INET6*/
+
+struct block *
+gen_portop(port, proto, dir)
+ int port, proto, dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ /* ip proto 'proto' */
+ tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto);
+ b0 = gen_ipfrag();
+ gen_and(tmp, b0);
+
+ switch (dir) {
+ case Q_SRC:
+ b1 = gen_portatom(0, (bpf_int32)port);
+ break;
+
+ case Q_DST:
+ b1 = gen_portatom(2, (bpf_int32)port);
+ break;
+
+ case Q_OR:
+ case Q_DEFAULT:
+ tmp = gen_portatom(0, (bpf_int32)port);
+ b1 = gen_portatom(2, (bpf_int32)port);
+ gen_or(tmp, b1);
+ break;
+
+ case Q_AND:
+ tmp = gen_portatom(0, (bpf_int32)port);
+ b1 = gen_portatom(2, (bpf_int32)port);
+ gen_and(tmp, b1);
+ break;
+
+ default:
+ abort();
+ }
+ gen_and(b0, b1);
+
+ return b1;
+}
+
+static struct block *
+gen_port(port, ip_proto, dir)
+ int port;
+ int ip_proto;
+ int dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ /*
+ * ether proto ip
+ *
+ * For FDDI, RFC 1188 says that SNAP encapsulation is used,
+ * not LLC encapsulation with LLCSAP_IP.
+ *
+ * For IEEE 802 networks - which includes 802.5 token ring
+ * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
+ * says that SNAP encapsulation is used, not LLC encapsulation
+ * with LLCSAP_IP.
+ *
+ * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
+ * RFC 2225 say that SNAP encapsulation is used, not LLC
+ * encapsulation with LLCSAP_IP.
+ *
+ * So we always check for ETHERTYPE_IP.
+ */
+ b0 = gen_linktype(ETHERTYPE_IP);
+
+ switch (ip_proto) {
+ case IPPROTO_UDP:
+ case IPPROTO_TCP:
+ case IPPROTO_SCTP:
+ b1 = gen_portop(port, ip_proto, dir);
+ break;
+
+ case PROTO_UNDEF:
+ tmp = gen_portop(port, IPPROTO_TCP, dir);
+ b1 = gen_portop(port, IPPROTO_UDP, dir);
+ gen_or(tmp, b1);
+ tmp = gen_portop(port, IPPROTO_SCTP, dir);
+ gen_or(tmp, b1);
+ break;
+
+ default:
+ abort();
+ }
+ gen_and(b0, b1);
+ return b1;
+}
+
+#ifdef INET6
+struct block *
+gen_portop6(port, proto, dir)
+ int port, proto, dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ /* ip6 proto 'proto' */
+ b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto);
+
+ switch (dir) {
+ case Q_SRC:
+ b1 = gen_portatom6(0, (bpf_int32)port);
+ break;
+
+ case Q_DST:
+ b1 = gen_portatom6(2, (bpf_int32)port);
+ break;
+
+ case Q_OR:
+ case Q_DEFAULT:
+ tmp = gen_portatom6(0, (bpf_int32)port);
+ b1 = gen_portatom6(2, (bpf_int32)port);
+ gen_or(tmp, b1);
+ break;
+
+ case Q_AND:
+ tmp = gen_portatom6(0, (bpf_int32)port);
+ b1 = gen_portatom6(2, (bpf_int32)port);
+ gen_and(tmp, b1);
+ break;
+
+ default:
+ abort();
+ }
+ gen_and(b0, b1);
+
+ return b1;
+}
+
+static struct block *
+gen_port6(port, ip_proto, dir)
+ int port;
+ int ip_proto;
+ int dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ /* link proto ip6 */
+ b0 = gen_linktype(ETHERTYPE_IPV6);
+
+ switch (ip_proto) {
+ case IPPROTO_UDP:
+ case IPPROTO_TCP:
+ case IPPROTO_SCTP:
+ b1 = gen_portop6(port, ip_proto, dir);
+ break;
+
+ case PROTO_UNDEF:
+ tmp = gen_portop6(port, IPPROTO_TCP, dir);
+ b1 = gen_portop6(port, IPPROTO_UDP, dir);
+ gen_or(tmp, b1);
+ tmp = gen_portop6(port, IPPROTO_SCTP, dir);
+ gen_or(tmp, b1);
+ break;
+
+ default:
+ abort();
+ }
+ gen_and(b0, b1);
+ return b1;
+}
+#endif /* INET6 */
+
+/* gen_portrange code */
+static struct block *
+gen_portrangeatom(off, v1, v2)
+ int off;
+ bpf_int32 v1, v2;
+{
+ struct block *b1, *b2;
+
+ if (v1 > v2) {
+ /*
+ * Reverse the order of the ports, so v1 is the lower one.
+ */
+ bpf_int32 vtemp;
+
+ vtemp = v1;
+ v1 = v2;
+ v2 = vtemp;
+ }
+
+ b1 = gen_cmp_ge(OR_TRAN_IPV4, off, BPF_H, v1);
+ b2 = gen_cmp_le(OR_TRAN_IPV4, off, BPF_H, v2);
+
+ gen_and(b1, b2);
+
+ return b2;
+}
+
+struct block *
+gen_portrangeop(port1, port2, proto, dir)
+ int port1, port2;
+ int proto;
+ int dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ /* ip proto 'proto' */
+ tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto);
+ b0 = gen_ipfrag();
+ gen_and(tmp, b0);
+
+ switch (dir) {
+ case Q_SRC:
+ b1 = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
+ break;
+
+ case Q_DST:
+ b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
+ break;
+
+ case Q_OR:
+ case Q_DEFAULT:
+ tmp = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
+ b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
+ gen_or(tmp, b1);
+ break;
+
+ case Q_AND:
+ tmp = gen_portrangeatom(0, (bpf_int32)port1, (bpf_int32)port2);
+ b1 = gen_portrangeatom(2, (bpf_int32)port1, (bpf_int32)port2);
+ gen_and(tmp, b1);
+ break;
+
+ default:
+ abort();
+ }
+ gen_and(b0, b1);
+
+ return b1;
+}
+
+static struct block *
+gen_portrange(port1, port2, ip_proto, dir)
+ int port1, port2;
+ int ip_proto;
+ int dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ /* link proto ip */
+ b0 = gen_linktype(ETHERTYPE_IP);
+
+ switch (ip_proto) {
+ case IPPROTO_UDP:
+ case IPPROTO_TCP:
+ case IPPROTO_SCTP:
+ b1 = gen_portrangeop(port1, port2, ip_proto, dir);
+ break;
+
+ case PROTO_UNDEF:
+ tmp = gen_portrangeop(port1, port2, IPPROTO_TCP, dir);
+ b1 = gen_portrangeop(port1, port2, IPPROTO_UDP, dir);
+ gen_or(tmp, b1);
+ tmp = gen_portrangeop(port1, port2, IPPROTO_SCTP, dir);
+ gen_or(tmp, b1);
+ break;
+
+ default:
+ abort();
+ }
+ gen_and(b0, b1);
+ return b1;
+}
+
+#ifdef INET6
+static struct block *
+gen_portrangeatom6(off, v1, v2)
+ int off;
+ bpf_int32 v1, v2;
+{
+ struct block *b1, *b2;
+
+ if (v1 > v2) {
+ /*
+ * Reverse the order of the ports, so v1 is the lower one.
+ */
+ bpf_int32 vtemp;
+
+ vtemp = v1;
+ v1 = v2;
+ v2 = vtemp;
+ }
+
+ b1 = gen_cmp_ge(OR_TRAN_IPV6, off, BPF_H, v1);
+ b2 = gen_cmp_le(OR_TRAN_IPV6, off, BPF_H, v2);
+
+ gen_and(b1, b2);
+
+ return b2;
+}
+
+struct block *
+gen_portrangeop6(port1, port2, proto, dir)
+ int port1, port2;
+ int proto;
+ int dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ /* ip6 proto 'proto' */
+ b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto);
+
+ switch (dir) {
+ case Q_SRC:
+ b1 = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
+ break;
+
+ case Q_DST:
+ b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
+ break;
+
+ case Q_OR:
+ case Q_DEFAULT:
+ tmp = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
+ b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
+ gen_or(tmp, b1);
+ break;
+
+ case Q_AND:
+ tmp = gen_portrangeatom6(0, (bpf_int32)port1, (bpf_int32)port2);
+ b1 = gen_portrangeatom6(2, (bpf_int32)port1, (bpf_int32)port2);
+ gen_and(tmp, b1);
+ break;
+
+ default:
+ abort();
+ }
+ gen_and(b0, b1);
+
+ return b1;
+}
+
+static struct block *
+gen_portrange6(port1, port2, ip_proto, dir)
+ int port1, port2;
+ int ip_proto;
+ int dir;
+{
+ struct block *b0, *b1, *tmp;
+
+ /* link proto ip6 */
+ b0 = gen_linktype(ETHERTYPE_IPV6);
+
+ switch (ip_proto) {
+ case IPPROTO_UDP:
+ case IPPROTO_TCP:
+ case IPPROTO_SCTP:
+ b1 = gen_portrangeop6(port1, port2, ip_proto, dir);
+ break;
+
+ case PROTO_UNDEF:
+ tmp = gen_portrangeop6(port1, port2, IPPROTO_TCP, dir);
+ b1 = gen_portrangeop6(port1, port2, IPPROTO_UDP, dir);
+ gen_or(tmp, b1);
+ tmp = gen_portrangeop6(port1, port2, IPPROTO_SCTP, dir);
+ gen_or(tmp, b1);
+ break;
+
+ default:
+ abort();
+ }
+ gen_and(b0, b1);
+ return b1;
+}
+#endif /* INET6 */
+
+static int
+lookup_proto(name, proto)
+ register const char *name;
+ register int proto;
+{
+ register int v;
+
+ switch (proto) {
+
+ case Q_DEFAULT:
+ case Q_IP:
+ case Q_IPV6:
+ v = pcap_nametoproto(name);
+ if (v == PROTO_UNDEF)
+ bpf_error("unknown ip proto '%s'", name);
+ break;
+
+ case Q_LINK:
+ /* XXX should look up h/w protocol type based on linktype */
+ v = pcap_nametoeproto(name);
+ if (v == PROTO_UNDEF) {
+ v = pcap_nametollc(name);
+ if (v == PROTO_UNDEF)
+ bpf_error("unknown ether proto '%s'", name);
+ }
+ break;
+
+ case Q_ISO:
+ if (strcmp(name, "esis") == 0)
+ v = ISO9542_ESIS;
+ else if (strcmp(name, "isis") == 0)
+ v = ISO10589_ISIS;
+ else if (strcmp(name, "clnp") == 0)
+ v = ISO8473_CLNP;
+ else
+ bpf_error("unknown osi proto '%s'", name);
+ break;
+
+ default:
+ v = PROTO_UNDEF;
+ break;
+ }
+ return v;
+}
+
+#if 0
+struct stmt *
+gen_joinsp(s, n)
+ struct stmt **s;
+ int n;
+{
+ return NULL;
+}
+#endif
+
+static struct block *
+gen_protochain(v, proto, dir)
+ int v;
+ int proto;
+ int dir;
+{
+#ifdef NO_PROTOCHAIN
+ return gen_proto(v, proto, dir);
+#else
+ struct block *b0, *b;
+ struct slist *s[100];
+ int fix2, fix3, fix4, fix5;
+ int ahcheck, again, end;
+ int i, max;
+ int reg2 = alloc_reg();
+
+ memset(s, 0, sizeof(s));
+ fix2 = fix3 = fix4 = fix5 = 0;
+
+ switch (proto) {
+ case Q_IP:
+ case Q_IPV6:
+ break;
+ case Q_DEFAULT:
+ b0 = gen_protochain(v, Q_IP, dir);
+ b = gen_protochain(v, Q_IPV6, dir);
+ gen_or(b0, b);
+ return b;
+ default:
+ bpf_error("bad protocol applied for 'protochain'");
+ /*NOTREACHED*/
+ }
+
+ /*
+ * We don't handle variable-length prefixes before the link-layer
+ * header, or variable-length link-layer headers, here yet.
+ * We might want to add BPF instructions to do the protochain
+ * work, to simplify that and, on platforms that have a BPF
+ * interpreter with the new instructions, let the filtering
+ * be done in the kernel. (We already require a modified BPF
+ * engine to do the protochain stuff, to support backward
+ * branches, and backward branch support is unlikely to appear
+ * in kernel BPF engines.)
+ */
+ switch (linktype) {
+
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
+ bpf_error("'protochain' not supported with 802.11");
+ }
+
+ no_optimize = 1; /*this code is not compatible with optimzer yet */
+
+ /*
+ * s[0] is a dummy entry to protect other BPF insn from damage
+ * by s[fix] = foo with uninitialized variable "fix". It is somewhat
+ * hard to find interdependency made by jump table fixup.
+ */
+ i = 0;
+ s[i] = new_stmt(0); /*dummy*/
+ i++;
+
+ switch (proto) {
+ case Q_IP:
+ b0 = gen_linktype(ETHERTYPE_IP);
+
+ /* A = ip->ip_p */
+ s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B);
+ s[i]->s.k = off_macpl + off_nl + 9;
+ i++;
+ /* X = ip->ip_hl << 2 */
+ s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
+ s[i]->s.k = off_macpl + off_nl;
+ i++;
+ break;
+#ifdef INET6
+ case Q_IPV6:
+ b0 = gen_linktype(ETHERTYPE_IPV6);
+
+ /* A = ip6->ip_nxt */
+ s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B);
+ s[i]->s.k = off_macpl + off_nl + 6;
+ i++;
+ /* X = sizeof(struct ip6_hdr) */
+ s[i] = new_stmt(BPF_LDX|BPF_IMM);
+ s[i]->s.k = 40;
+ i++;
+ break;
+#endif
+ default:
+ bpf_error("unsupported proto to gen_protochain");
+ /*NOTREACHED*/
+ }
+
+ /* again: if (A == v) goto end; else fall through; */
+ again = i;
+ s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
+ s[i]->s.k = v;
+ s[i]->s.jt = NULL; /*later*/
+ s[i]->s.jf = NULL; /*update in next stmt*/
+ fix5 = i;
+ i++;
+
+#ifndef IPPROTO_NONE
+#define IPPROTO_NONE 59
+#endif
+ /* if (A == IPPROTO_NONE) goto end */
+ s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
+ s[i]->s.jt = NULL; /*later*/
+ s[i]->s.jf = NULL; /*update in next stmt*/
+ s[i]->s.k = IPPROTO_NONE;
+ s[fix5]->s.jf = s[i];
+ fix2 = i;
+ i++;
+
+#ifdef INET6
+ if (proto == Q_IPV6) {
+ int v6start, v6end, v6advance, j;
+
+ v6start = i;
+ /* if (A == IPPROTO_HOPOPTS) goto v6advance */
+ s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
+ s[i]->s.jt = NULL; /*later*/
+ s[i]->s.jf = NULL; /*update in next stmt*/
+ s[i]->s.k = IPPROTO_HOPOPTS;
+ s[fix2]->s.jf = s[i];
+ i++;
+ /* if (A == IPPROTO_DSTOPTS) goto v6advance */
+ s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
+ s[i]->s.jt = NULL; /*later*/
+ s[i]->s.jf = NULL; /*update in next stmt*/
+ s[i]->s.k = IPPROTO_DSTOPTS;
+ i++;
+ /* if (A == IPPROTO_ROUTING) goto v6advance */
+ s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
+ s[i]->s.jt = NULL; /*later*/
+ s[i]->s.jf = NULL; /*update in next stmt*/
+ s[i]->s.k = IPPROTO_ROUTING;
+ i++;
+ /* if (A == IPPROTO_FRAGMENT) goto v6advance; else goto ahcheck; */
+ s[i - 1]->s.jf = s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
+ s[i]->s.jt = NULL; /*later*/
+ s[i]->s.jf = NULL; /*later*/
+ s[i]->s.k = IPPROTO_FRAGMENT;
+ fix3 = i;
+ v6end = i;
+ i++;
+
+ /* v6advance: */
+ v6advance = i;
+
+ /*
+ * in short,
+ * A = P[X];
+ * X = X + (P[X + 1] + 1) * 8;
+ */
+ /* A = X */
+ s[i] = new_stmt(BPF_MISC|BPF_TXA);
+ i++;
+ /* A = P[X + packet head] */
+ s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
+ s[i]->s.k = off_macpl + off_nl;
+ i++;
+ /* MEM[reg2] = A */
+ s[i] = new_stmt(BPF_ST);
+ s[i]->s.k = reg2;
+ i++;
+ /* A = X */
+ s[i] = new_stmt(BPF_MISC|BPF_TXA);
+ i++;
+ /* A += 1 */
+ s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
+ s[i]->s.k = 1;
+ i++;
+ /* X = A */
+ s[i] = new_stmt(BPF_MISC|BPF_TAX);
+ i++;
+ /* A = P[X + packet head]; */
+ s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
+ s[i]->s.k = off_macpl + off_nl;
+ i++;
+ /* A += 1 */
+ s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
+ s[i]->s.k = 1;
+ i++;
+ /* A *= 8 */
+ s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K);
+ s[i]->s.k = 8;
+ i++;
+ /* X = A; */
+ s[i] = new_stmt(BPF_MISC|BPF_TAX);
+ i++;
+ /* A = MEM[reg2] */
+ s[i] = new_stmt(BPF_LD|BPF_MEM);
+ s[i]->s.k = reg2;
+ i++;
+
+ /* goto again; (must use BPF_JA for backward jump) */
+ s[i] = new_stmt(BPF_JMP|BPF_JA);
+ s[i]->s.k = again - i - 1;
+ s[i - 1]->s.jf = s[i];
+ i++;
+
+ /* fixup */
+ for (j = v6start; j <= v6end; j++)
+ s[j]->s.jt = s[v6advance];
+ } else
+#endif
+ {
+ /* nop */
+ s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
+ s[i]->s.k = 0;
+ s[fix2]->s.jf = s[i];
+ i++;
+ }
+
+ /* ahcheck: */
+ ahcheck = i;
+ /* if (A == IPPROTO_AH) then fall through; else goto end; */
+ s[i] = new_stmt(BPF_JMP|BPF_JEQ|BPF_K);
+ s[i]->s.jt = NULL; /*later*/
+ s[i]->s.jf = NULL; /*later*/
+ s[i]->s.k = IPPROTO_AH;
+ if (fix3)
+ s[fix3]->s.jf = s[ahcheck];
+ fix4 = i;
+ i++;
+
+ /*
+ * in short,
+ * A = P[X];
+ * X = X + (P[X + 1] + 2) * 4;
+ */
+ /* A = X */
+ s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA);
+ i++;
+ /* A = P[X + packet head]; */
+ s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
+ s[i]->s.k = off_macpl + off_nl;
+ i++;
+ /* MEM[reg2] = A */
+ s[i] = new_stmt(BPF_ST);
+ s[i]->s.k = reg2;
+ i++;
+ /* A = X */
+ s[i - 1]->s.jt = s[i] = new_stmt(BPF_MISC|BPF_TXA);
+ i++;
+ /* A += 1 */
+ s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
+ s[i]->s.k = 1;
+ i++;
+ /* X = A */
+ s[i] = new_stmt(BPF_MISC|BPF_TAX);
+ i++;
+ /* A = P[X + packet head] */
+ s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
+ s[i]->s.k = off_macpl + off_nl;
+ i++;
+ /* A += 2 */
+ s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
+ s[i]->s.k = 2;
+ i++;
+ /* A *= 4 */
+ s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K);
+ s[i]->s.k = 4;
+ i++;
+ /* X = A; */
+ s[i] = new_stmt(BPF_MISC|BPF_TAX);
+ i++;
+ /* A = MEM[reg2] */
+ s[i] = new_stmt(BPF_LD|BPF_MEM);
+ s[i]->s.k = reg2;
+ i++;
+
+ /* goto again; (must use BPF_JA for backward jump) */
+ s[i] = new_stmt(BPF_JMP|BPF_JA);
+ s[i]->s.k = again - i - 1;
+ i++;
+
+ /* end: nop */
+ end = i;
+ s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
+ s[i]->s.k = 0;
+ s[fix2]->s.jt = s[end];
+ s[fix4]->s.jf = s[end];
+ s[fix5]->s.jt = s[end];
+ i++;
+
+ /*
+ * make slist chain
+ */
+ max = i;
+ for (i = 0; i < max - 1; i++)
+ s[i]->next = s[i + 1];
+ s[max - 1]->next = NULL;
+
+ /*
+ * emit final check
+ */
+ b = new_block(JMP(BPF_JEQ));
+ b->stmts = s[1]; /*remember, s[0] is dummy*/
+ b->s.k = v;
+
+ free_reg(reg2);
+
+ gen_and(b0, b);
+ return b;
+#endif
+}
+
+static struct block *
+gen_check_802_11_data_frame()
+{
+ struct slist *s;
+ struct block *b0, *b1;
+
+ /*
+ * A data frame has the 0x08 bit (b3) in the frame control field set
+ * and the 0x04 bit (b2) clear.
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b0 = new_block(JMP(BPF_JSET));
+ b0->s.k = 0x08;
+ b0->stmts = s;
+
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x04;
+ b1->stmts = s;
+ gen_not(b1);
+
+ gen_and(b1, b0);
+
+ return b0;
+}
+
+/*
+ * Generate code that checks whether the packet is a packet for protocol
+ * <proto> and whether the type field in that protocol's header has
+ * the value <v>, e.g. if <proto> is Q_IP, it checks whether it's an
+ * IP packet and checks the protocol number in the IP header against <v>.
+ *
+ * If <proto> is Q_DEFAULT, i.e. just "proto" was specified, it checks
+ * against Q_IP and Q_IPV6.
+ */
+static struct block *
+gen_proto(v, proto, dir)
+ int v;
+ int proto;
+ int dir;
+{
+ struct block *b0, *b1;
+
+ if (dir != Q_DEFAULT)
+ bpf_error("direction applied to 'proto'");
+
+ switch (proto) {
+ case Q_DEFAULT:
+#ifdef INET6
+ b0 = gen_proto(v, Q_IP, dir);
+ b1 = gen_proto(v, Q_IPV6, dir);
+ gen_or(b0, b1);
+ return b1;
+#else
+ /*FALLTHROUGH*/
+#endif
+ case Q_IP:
+ /*
+ * For FDDI, RFC 1188 says that SNAP encapsulation is used,
+ * not LLC encapsulation with LLCSAP_IP.
+ *
+ * For IEEE 802 networks - which includes 802.5 token ring
+ * (which is what DLT_IEEE802 means) and 802.11 - RFC 1042
+ * says that SNAP encapsulation is used, not LLC encapsulation
+ * with LLCSAP_IP.
+ *
+ * For LLC-encapsulated ATM/"Classical IP", RFC 1483 and
+ * RFC 2225 say that SNAP encapsulation is used, not LLC
+ * encapsulation with LLCSAP_IP.
+ *
+ * So we always check for ETHERTYPE_IP.
+ */
+ b0 = gen_linktype(ETHERTYPE_IP);
+#ifndef CHASE_CHAIN
+ b1 = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)v);
+#else
+ b1 = gen_protochain(v, Q_IP);
+#endif
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_ISO:
+ switch (linktype) {
+
+ case DLT_FRELAY:
+ /*
+ * Frame Relay packets typically have an OSI
+ * NLPID at the beginning; "gen_linktype(LLCSAP_ISONS)"
+ * generates code to check for all the OSI
+ * NLPIDs, so calling it and then adding a check
+ * for the particular NLPID for which we're
+ * looking is bogus, as we can just check for
+ * the NLPID.
+ *
+ * What we check for is the NLPID and a frame
+ * control field value of UI, i.e. 0x03 followed
+ * by the NLPID.
+ *
+ * XXX - assumes a 2-byte Frame Relay header with
+ * DLCI and flags. What if the address is longer?
+ *
+ * XXX - what about SNAP-encapsulated frames?
+ */
+ return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | v);
+ /*NOTREACHED*/
+ break;
+
+ case DLT_C_HDLC:
+ /*
+ * Cisco uses an Ethertype lookalike - for OSI,
+ * it's 0xfefe.
+ */
+ b0 = gen_linktype(LLCSAP_ISONS<<8 | LLCSAP_ISONS);
+ /* OSI in C-HDLC is stuffed with a fudge byte */
+ b1 = gen_cmp(OR_NET_NOSNAP, 1, BPF_B, (long)v);
+ gen_and(b0, b1);
+ return b1;
+
+ default:
+ b0 = gen_linktype(LLCSAP_ISONS);
+ b1 = gen_cmp(OR_NET_NOSNAP, 0, BPF_B, (long)v);
+ gen_and(b0, b1);
+ return b1;
+ }
+
+ case Q_ISIS:
+ b0 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT);
+ /*
+ * 4 is the offset of the PDU type relative to the IS-IS
+ * header.
+ */
+ b1 = gen_cmp(OR_NET_NOSNAP, 4, BPF_B, (long)v);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_ARP:
+ bpf_error("arp does not encapsulate another protocol");
+ /* NOTREACHED */
+
+ case Q_RARP:
+ bpf_error("rarp does not encapsulate another protocol");
+ /* NOTREACHED */
+
+ case Q_ATALK:
+ bpf_error("atalk encapsulation is not specifiable");
+ /* NOTREACHED */
+
+ case Q_DECNET:
+ bpf_error("decnet encapsulation is not specifiable");
+ /* NOTREACHED */
+
+ case Q_SCA:
+ bpf_error("sca does not encapsulate another protocol");
+ /* NOTREACHED */
+
+ case Q_LAT:
+ bpf_error("lat does not encapsulate another protocol");
+ /* NOTREACHED */
+
+ case Q_MOPRC:
+ bpf_error("moprc does not encapsulate another protocol");
+ /* NOTREACHED */
+
+ case Q_MOPDL:
+ bpf_error("mopdl does not encapsulate another protocol");
+ /* NOTREACHED */
+
+ case Q_LINK:
+ return gen_linktype(v);
+
+ case Q_UDP:
+ bpf_error("'udp proto' is bogus");
+ /* NOTREACHED */
+
+ case Q_TCP:
+ bpf_error("'tcp proto' is bogus");
+ /* NOTREACHED */
+
+ case Q_SCTP:
+ bpf_error("'sctp proto' is bogus");
+ /* NOTREACHED */
+
+ case Q_ICMP:
+ bpf_error("'icmp proto' is bogus");
+ /* NOTREACHED */
+
+ case Q_IGMP:
+ bpf_error("'igmp proto' is bogus");
+ /* NOTREACHED */
+
+ case Q_IGRP:
+ bpf_error("'igrp proto' is bogus");
+ /* NOTREACHED */
+
+ case Q_PIM:
+ bpf_error("'pim proto' is bogus");
+ /* NOTREACHED */
+
+ case Q_VRRP:
+ bpf_error("'vrrp proto' is bogus");
+ /* NOTREACHED */
+
+#ifdef INET6
+ case Q_IPV6:
+ b0 = gen_linktype(ETHERTYPE_IPV6);
+#ifndef CHASE_CHAIN
+ b1 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)v);
+#else
+ b1 = gen_protochain(v, Q_IPV6);
+#endif
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_ICMPV6:
+ bpf_error("'icmp6 proto' is bogus");
+#endif /* INET6 */
+
+ case Q_AH:
+ bpf_error("'ah proto' is bogus");
+
+ case Q_ESP:
+ bpf_error("'ah proto' is bogus");
+
+ case Q_STP:
+ bpf_error("'stp proto' is bogus");
+
+ case Q_IPX:
+ bpf_error("'ipx proto' is bogus");
+
+ case Q_NETBEUI:
+ bpf_error("'netbeui proto' is bogus");
+
+ case Q_RADIO:
+ bpf_error("'radio proto' is bogus");
+
+ default:
+ abort();
+ /* NOTREACHED */
+ }
+ /* NOTREACHED */
+}
+
+struct block *
+gen_scode(name, q)
+ register const char *name;
+ struct qual q;
+{
+ int proto = q.proto;
+ int dir = q.dir;
+ int tproto;
+ u_char *eaddr;
+ bpf_u_int32 mask, addr;
+#ifndef INET6
+ bpf_u_int32 **alist;
+#else
+ int tproto6;
+ struct sockaddr_in *sin4;
+ struct sockaddr_in6 *sin6;
+ struct addrinfo *res, *res0;
+ struct in6_addr mask128;
+#endif /*INET6*/
+ struct block *b, *tmp;
+ int port, real_proto;
+ int port1, port2;
+
+ switch (q.addr) {
+
+ case Q_NET:
+ addr = pcap_nametonetaddr(name);
+ if (addr == 0)
+ bpf_error("unknown network '%s'", name);
+ /* Left justify network addr and calculate its network mask */
+ mask = 0xffffffff;
+ while (addr && (addr & 0xff000000) == 0) {
+ addr <<= 8;
+ mask <<= 8;
+ }
+ return gen_host(addr, mask, proto, dir, q.addr);
+
+ case Q_DEFAULT:
+ case Q_HOST:
+ if (proto == Q_LINK) {
+ switch (linktype) {
+
+ case DLT_EN10MB:
+ eaddr = pcap_ether_hostton(name);
+ if (eaddr == NULL)
+ bpf_error(
+ "unknown ether host '%s'", name);
+ b = gen_ehostop(eaddr, dir);
+ free(eaddr);
+ return b;
+
+ case DLT_FDDI:
+ eaddr = pcap_ether_hostton(name);
+ if (eaddr == NULL)
+ bpf_error(
+ "unknown FDDI host '%s'", name);
+ b = gen_fhostop(eaddr, dir);
+ free(eaddr);
+ return b;
+
+ case DLT_IEEE802:
+ eaddr = pcap_ether_hostton(name);
+ if (eaddr == NULL)
+ bpf_error(
+ "unknown token ring host '%s'", name);
+ b = gen_thostop(eaddr, dir);
+ free(eaddr);
+ return b;
+
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
+ eaddr = pcap_ether_hostton(name);
+ if (eaddr == NULL)
+ bpf_error(
+ "unknown 802.11 host '%s'", name);
+ b = gen_wlanhostop(eaddr, dir);
+ free(eaddr);
+ return b;
+
+ case DLT_IP_OVER_FC:
+ eaddr = pcap_ether_hostton(name);
+ if (eaddr == NULL)
+ bpf_error(
+ "unknown Fibre Channel host '%s'", name);
+ b = gen_ipfchostop(eaddr, dir);
+ free(eaddr);
+ return b;
+
+ case DLT_SUNATM:
+ if (!is_lane)
+ break;
+
+ /*
+ * Check that the packet doesn't begin
+ * with an LE Control marker. (We've
+ * already generated a test for LANE.)
+ */
+ tmp = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS,
+ BPF_H, 0xFF00);
+ gen_not(tmp);
+
+ eaddr = pcap_ether_hostton(name);
+ if (eaddr == NULL)
+ bpf_error(
+ "unknown ether host '%s'", name);
+ b = gen_ehostop(eaddr, dir);
+ gen_and(tmp, b);
+ free(eaddr);
+ return b;
+ }
+
+ bpf_error("only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name");
+ } else if (proto == Q_DECNET) {
+ unsigned short dn_addr = __pcap_nametodnaddr(name);
+ /*
+ * I don't think DECNET hosts can be multihomed, so
+ * there is no need to build up a list of addresses
+ */
+ return (gen_host(dn_addr, 0, proto, dir, q.addr));
+ } else {
+#ifndef INET6
+ alist = pcap_nametoaddr(name);
+ if (alist == NULL || *alist == NULL)
+ bpf_error("unknown host '%s'", name);
+ tproto = proto;
+ if (off_linktype == (u_int)-1 && tproto == Q_DEFAULT)
+ tproto = Q_IP;
+ b = gen_host(**alist++, 0xffffffff, tproto, dir, q.addr);
+ while (*alist) {
+ tmp = gen_host(**alist++, 0xffffffff,
+ tproto, dir, q.addr);
+ gen_or(b, tmp);
+ b = tmp;
+ }
+ return b;
+#else
+ memset(&mask128, 0xff, sizeof(mask128));
+ res0 = res = pcap_nametoaddrinfo(name);
+ if (res == NULL)
+ bpf_error("unknown host '%s'", name);
+ b = tmp = NULL;
+ tproto = tproto6 = proto;
+ if (off_linktype == -1 && tproto == Q_DEFAULT) {
+ tproto = Q_IP;
+ tproto6 = Q_IPV6;
+ }
+ for (res = res0; res; res = res->ai_next) {
+ switch (res->ai_family) {
+ case AF_INET:
+ if (tproto == Q_IPV6)
+ continue;
+
+ sin4 = (struct sockaddr_in *)
+ res->ai_addr;
+ tmp = gen_host(ntohl(sin4->sin_addr.s_addr),
+ 0xffffffff, tproto, dir, q.addr);
+ break;
+ case AF_INET6:
+ if (tproto6 == Q_IP)
+ continue;
+
+ sin6 = (struct sockaddr_in6 *)
+ res->ai_addr;
+ tmp = gen_host6(&sin6->sin6_addr,
+ &mask128, tproto6, dir, q.addr);
+ break;
+ default:
+ continue;
+ }
+ if (b)
+ gen_or(b, tmp);
+ b = tmp;
+ }
+ freeaddrinfo(res0);
+ if (b == NULL) {
+ bpf_error("unknown host '%s'%s", name,
+ (proto == Q_DEFAULT)
+ ? ""
+ : " for specified address family");
+ }
+ return b;
+#endif /*INET6*/
+ }
+
+ case Q_PORT:
+ if (proto != Q_DEFAULT &&
+ proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
+ bpf_error("illegal qualifier of 'port'");
+ if (pcap_nametoport(name, &port, &real_proto) == 0)
+ bpf_error("unknown port '%s'", name);
+ if (proto == Q_UDP) {
+ if (real_proto == IPPROTO_TCP)
+ bpf_error("port '%s' is tcp", name);
+ else if (real_proto == IPPROTO_SCTP)
+ bpf_error("port '%s' is sctp", name);
+ else
+ /* override PROTO_UNDEF */
+ real_proto = IPPROTO_UDP;
+ }
+ if (proto == Q_TCP) {
+ if (real_proto == IPPROTO_UDP)
+ bpf_error("port '%s' is udp", name);
+
+ else if (real_proto == IPPROTO_SCTP)
+ bpf_error("port '%s' is sctp", name);
+ else
+ /* override PROTO_UNDEF */
+ real_proto = IPPROTO_TCP;
+ }
+ if (proto == Q_SCTP) {
+ if (real_proto == IPPROTO_UDP)
+ bpf_error("port '%s' is udp", name);
+
+ else if (real_proto == IPPROTO_TCP)
+ bpf_error("port '%s' is tcp", name);
+ else
+ /* override PROTO_UNDEF */
+ real_proto = IPPROTO_SCTP;
+ }
+#ifndef INET6
+ return gen_port(port, real_proto, dir);
+#else
+ b = gen_port(port, real_proto, dir);
+ gen_or(gen_port6(port, real_proto, dir), b);
+ return b;
+#endif /* INET6 */
+
+ case Q_PORTRANGE:
+ if (proto != Q_DEFAULT &&
+ proto != Q_UDP && proto != Q_TCP && proto != Q_SCTP)
+ bpf_error("illegal qualifier of 'portrange'");
+ if (pcap_nametoportrange(name, &port1, &port2, &real_proto) == 0)
+ bpf_error("unknown port in range '%s'", name);
+ if (proto == Q_UDP) {
+ if (real_proto == IPPROTO_TCP)
+ bpf_error("port in range '%s' is tcp", name);
+ else if (real_proto == IPPROTO_SCTP)
+ bpf_error("port in range '%s' is sctp", name);
+ else
+ /* override PROTO_UNDEF */
+ real_proto = IPPROTO_UDP;
+ }
+ if (proto == Q_TCP) {
+ if (real_proto == IPPROTO_UDP)
+ bpf_error("port in range '%s' is udp", name);
+ else if (real_proto == IPPROTO_SCTP)
+ bpf_error("port in range '%s' is sctp", name);
+ else
+ /* override PROTO_UNDEF */
+ real_proto = IPPROTO_TCP;
+ }
+ if (proto == Q_SCTP) {
+ if (real_proto == IPPROTO_UDP)
+ bpf_error("port in range '%s' is udp", name);
+ else if (real_proto == IPPROTO_TCP)
+ bpf_error("port in range '%s' is tcp", name);
+ else
+ /* override PROTO_UNDEF */
+ real_proto = IPPROTO_SCTP;
+ }
+#ifndef INET6
+ return gen_portrange(port1, port2, real_proto, dir);
+#else
+ b = gen_portrange(port1, port2, real_proto, dir);
+ gen_or(gen_portrange6(port1, port2, real_proto, dir), b);
+ return b;
+#endif /* INET6 */
+
+ case Q_GATEWAY:
+#ifndef INET6
+ eaddr = pcap_ether_hostton(name);
+ if (eaddr == NULL)
+ bpf_error("unknown ether host: %s", name);
+
+ alist = pcap_nametoaddr(name);
+ if (alist == NULL || *alist == NULL)
+ bpf_error("unknown host '%s'", name);
+ b = gen_gateway(eaddr, alist, proto, dir);
+ free(eaddr);
+ return b;
+#else
+ bpf_error("'gateway' not supported in this configuration");
+#endif /*INET6*/
+
+ case Q_PROTO:
+ real_proto = lookup_proto(name, proto);
+ if (real_proto >= 0)
+ return gen_proto(real_proto, proto, dir);
+ else
+ bpf_error("unknown protocol: %s", name);
+
+ case Q_PROTOCHAIN:
+ real_proto = lookup_proto(name, proto);
+ if (real_proto >= 0)
+ return gen_protochain(real_proto, proto, dir);
+ else
+ bpf_error("unknown protocol: %s", name);
+
+ case Q_UNDEF:
+ syntax();
+ /* NOTREACHED */
+ }
+ abort();
+ /* NOTREACHED */
+}
+
+struct block *
+gen_mcode(s1, s2, masklen, q)
+ register const char *s1, *s2;
+ register int masklen;
+ struct qual q;
+{
+ register int nlen, mlen;
+ bpf_u_int32 n, m;
+
+ nlen = __pcap_atoin(s1, &n);
+ /* Promote short ipaddr */
+ n <<= 32 - nlen;
+
+ if (s2 != NULL) {
+ mlen = __pcap_atoin(s2, &m);
+ /* Promote short ipaddr */
+ m <<= 32 - mlen;
+ if ((n & ~m) != 0)
+ bpf_error("non-network bits set in \"%s mask %s\"",
+ s1, s2);
+ } else {
+ /* Convert mask len to mask */
+ if (masklen > 32)
+ bpf_error("mask length must be <= 32");
+ if (masklen == 0) {
+ /*
+ * X << 32 is not guaranteed by C to be 0; it's
+ * undefined.
+ */
+ m = 0;
+ } else
+ m = 0xffffffff << (32 - masklen);
+ if ((n & ~m) != 0)
+ bpf_error("non-network bits set in \"%s/%d\"",
+ s1, masklen);
+ }
+
+ switch (q.addr) {
+
+ case Q_NET:
+ return gen_host(n, m, q.proto, q.dir, q.addr);
+
+ default:
+ bpf_error("Mask syntax for networks only");
+ /* NOTREACHED */
+ }
+ /* NOTREACHED */
+ return NULL;
+}
+
+struct block *
+gen_ncode(s, v, q)
+ register const char *s;
+ bpf_u_int32 v;
+ struct qual q;
+{
+ bpf_u_int32 mask;
+ int proto = q.proto;
+ int dir = q.dir;
+ register int vlen;
+
+ if (s == NULL)
+ vlen = 32;
+ else if (q.proto == Q_DECNET)
+ vlen = __pcap_atodn(s, &v);
+ else
+ vlen = __pcap_atoin(s, &v);
+
+ switch (q.addr) {
+
+ case Q_DEFAULT:
+ case Q_HOST:
+ case Q_NET:
+ if (proto == Q_DECNET)
+ return gen_host(v, 0, proto, dir, q.addr);
+ else if (proto == Q_LINK) {
+ bpf_error("illegal link layer address");
+ } else {
+ mask = 0xffffffff;
+ if (s == NULL && q.addr == Q_NET) {
+ /* Promote short net number */
+ while (v && (v & 0xff000000) == 0) {
+ v <<= 8;
+ mask <<= 8;
+ }
+ } else {
+ /* Promote short ipaddr */
+ v <<= 32 - vlen;
+ mask <<= 32 - vlen;
+ }
+ return gen_host(v, mask, proto, dir, q.addr);
+ }
+
+ case Q_PORT:
+ if (proto == Q_UDP)
+ proto = IPPROTO_UDP;
+ else if (proto == Q_TCP)
+ proto = IPPROTO_TCP;
+ else if (proto == Q_SCTP)
+ proto = IPPROTO_SCTP;
+ else if (proto == Q_DEFAULT)
+ proto = PROTO_UNDEF;
+ else
+ bpf_error("illegal qualifier of 'port'");
+
+#ifndef INET6
+ return gen_port((int)v, proto, dir);
+#else
+ {
+ struct block *b;
+ b = gen_port((int)v, proto, dir);
+ gen_or(gen_port6((int)v, proto, dir), b);
+ return b;
+ }
+#endif /* INET6 */
+
+ case Q_PORTRANGE:
+ if (proto == Q_UDP)
+ proto = IPPROTO_UDP;
+ else if (proto == Q_TCP)
+ proto = IPPROTO_TCP;
+ else if (proto == Q_SCTP)
+ proto = IPPROTO_SCTP;
+ else if (proto == Q_DEFAULT)
+ proto = PROTO_UNDEF;
+ else
+ bpf_error("illegal qualifier of 'portrange'");
+
+#ifndef INET6
+ return gen_portrange((int)v, (int)v, proto, dir);
+#else
+ {
+ struct block *b;
+ b = gen_portrange((int)v, (int)v, proto, dir);
+ gen_or(gen_portrange6((int)v, (int)v, proto, dir), b);
+ return b;
+ }
+#endif /* INET6 */
+
+ case Q_GATEWAY:
+ bpf_error("'gateway' requires a name");
+ /* NOTREACHED */
+
+ case Q_PROTO:
+ return gen_proto((int)v, proto, dir);
- case ETHERTYPE_ATALK:
- proto = PPP_APPLE;
- break;
+ case Q_PROTOCHAIN:
+ return gen_protochain((int)v, proto, dir);
- case ETHERTYPE_NS:
- proto = PPP_NS;
- break;
- }
- break;
+ case Q_UNDEF:
+ syntax();
+ /* NOTREACHED */
- case DLT_NULL:
- /* XXX */
- if (proto == ETHERTYPE_IP)
- return (gen_cmp(0, BPF_W, (bpf_int32)htonl(AF_INET)));
- else
- return gen_false();
+ default:
+ abort();
+ /* NOTREACHED */
}
- return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto);
+ /* NOTREACHED */
}
-static struct block *
-gen_hostop(addr, mask, dir, proto, src_off, dst_off)
- bpf_u_int32 addr;
- bpf_u_int32 mask;
- int dir, proto;
- u_int src_off, dst_off;
+#ifdef INET6
+struct block *
+gen_mcode6(s1, s2, masklen, q)
+ register const char *s1, *s2;
+ register int masklen;
+ struct qual q;
{
- struct block *b0, *b1;
- u_int offset;
-
- switch (dir) {
-
- case Q_SRC:
- offset = src_off;
- break;
+ struct addrinfo *res;
+ struct in6_addr *addr;
+ struct in6_addr mask;
+ struct block *b;
+ u_int32_t *a, *m;
+
+ if (s2)
+ bpf_error("no mask %s supported", s2);
+
+ res = pcap_nametoaddrinfo(s1);
+ if (!res)
+ bpf_error("invalid ip6 address %s", s1);
+ if (res->ai_next)
+ bpf_error("%s resolved to multiple address", s1);
+ addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
+
+ if (sizeof(mask) * 8 < masklen)
+ bpf_error("mask length must be <= %u", (unsigned int)(sizeof(mask) * 8));
+ memset(&mask, 0, sizeof(mask));
+ memset(&mask, 0xff, masklen / 8);
+ if (masklen % 8) {
+ mask.s6_addr[masklen / 8] =
+ (0xff << (8 - masklen % 8)) & 0xff;
+ }
- case Q_DST:
- offset = dst_off;
- break;
+ a = (u_int32_t *)addr;
+ m = (u_int32_t *)&mask;
+ if ((a[0] & ~m[0]) || (a[1] & ~m[1])
+ || (a[2] & ~m[2]) || (a[3] & ~m[3])) {
+ bpf_error("non-network bits set in \"%s/%d\"", s1, masklen);
+ }
- case Q_AND:
- b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
- b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
- gen_and(b0, b1);
- return b1;
+ switch (q.addr) {
- case Q_OR:
case Q_DEFAULT:
- b0 = gen_hostop(addr, mask, Q_SRC, proto, src_off, dst_off);
- b1 = gen_hostop(addr, mask, Q_DST, proto, src_off, dst_off);
- gen_or(b0, b1);
- return b1;
+ case Q_HOST:
+ if (masklen != 128)
+ bpf_error("Mask syntax for networks only");
+ /* FALLTHROUGH */
+
+ case Q_NET:
+ b = gen_host6(addr, &mask, q.proto, q.dir, q.addr);
+ freeaddrinfo(res);
+ return b;
default:
- abort();
+ bpf_error("invalid qualifier against IPv6 address");
+ /* NOTREACHED */
}
- b0 = gen_linktype(proto);
- b1 = gen_mcmp(offset, BPF_W, (bpf_int32)addr, mask);
- gen_and(b0, b1);
- return b1;
+ return NULL;
}
+#endif /*INET6*/
-static struct block *
-gen_ehostop(eaddr, dir)
+struct block *
+gen_ecode(eaddr, q)
register const u_char *eaddr;
- register int dir;
+ struct qual q;
{
- register struct block *b0, *b1;
-
- switch (dir) {
- case Q_SRC:
- return gen_bcmp(6, 6, eaddr);
-
- case Q_DST:
- return gen_bcmp(0, 6, eaddr);
-
- case Q_AND:
- b0 = gen_ehostop(eaddr, Q_SRC);
- b1 = gen_ehostop(eaddr, Q_DST);
- gen_and(b0, b1);
- return b1;
+ struct block *b, *tmp;
- case Q_DEFAULT:
- case Q_OR:
- b0 = gen_ehostop(eaddr, Q_SRC);
- b1 = gen_ehostop(eaddr, Q_DST);
- gen_or(b0, b1);
- return b1;
+ if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
+ switch (linktype) {
+ case DLT_EN10MB:
+ return gen_ehostop(eaddr, (int)q.dir);
+ case DLT_FDDI:
+ return gen_fhostop(eaddr, (int)q.dir);
+ case DLT_IEEE802:
+ return gen_thostop(eaddr, (int)q.dir);
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
+ return gen_wlanhostop(eaddr, (int)q.dir);
+ case DLT_SUNATM:
+ if (is_lane) {
+ /*
+ * Check that the packet doesn't begin with an
+ * LE Control marker. (We've already generated
+ * a test for LANE.)
+ */
+ tmp = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS, BPF_H,
+ 0xFF00);
+ gen_not(tmp);
+
+ /*
+ * Now check the MAC address.
+ */
+ b = gen_ehostop(eaddr, (int)q.dir);
+ gen_and(tmp, b);
+ return b;
+ }
+ break;
+ case DLT_IP_OVER_FC:
+ return gen_ipfchostop(eaddr, (int)q.dir);
+ default:
+ bpf_error("ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
+ break;
+ }
}
- abort();
+ bpf_error("ethernet address used in non-ether expression");
/* NOTREACHED */
+ return NULL;
}
-/*
- * Like gen_ehostop, but for DLT_FDDI
- */
-static struct block *
-gen_fhostop(eaddr, dir)
- register const u_char *eaddr;
- register int dir;
+void
+sappend(s0, s1)
+ struct slist *s0, *s1;
{
- struct block *b0, *b1;
+ /*
+ * This is definitely not the best way to do this, but the
+ * lists will rarely get long.
+ */
+ while (s0->next)
+ s0 = s0->next;
+ s0->next = s1;
+}
- switch (dir) {
- case Q_SRC:
-#ifdef PCAP_FDDIPAD
- return gen_bcmp(6 + 1 + pcap_fddipad, 6, eaddr);
-#else
- return gen_bcmp(6 + 1, 6, eaddr);
-#endif
+static struct slist *
+xfer_to_x(a)
+ struct arth *a;
+{
+ struct slist *s;
- case Q_DST:
-#ifdef PCAP_FDDIPAD
- return gen_bcmp(0 + 1 + pcap_fddipad, 6, eaddr);
-#else
- return gen_bcmp(0 + 1, 6, eaddr);
-#endif
+ s = new_stmt(BPF_LDX|BPF_MEM);
+ s->s.k = a->regno;
+ return s;
+}
- case Q_AND:
- b0 = gen_fhostop(eaddr, Q_SRC);
- b1 = gen_fhostop(eaddr, Q_DST);
- gen_and(b0, b1);
- return b1;
+static struct slist *
+xfer_to_a(a)
+ struct arth *a;
+{
+ struct slist *s;
- case Q_DEFAULT:
- case Q_OR:
- b0 = gen_fhostop(eaddr, Q_SRC);
- b1 = gen_fhostop(eaddr, Q_DST);
- gen_or(b0, b1);
- return b1;
- }
- abort();
- /* NOTREACHED */
+ s = new_stmt(BPF_LD|BPF_MEM);
+ s->s.k = a->regno;
+ return s;
}
/*
- * This is quite tricky because there may be pad bytes in front of the
- * DECNET header, and then there are two possible data packet formats that
- * carry both src and dst addresses, plus 5 packet types in a format that
- * carries only the src node, plus 2 types that use a different format and
- * also carry just the src node.
- *
- * Yuck.
- *
- * Instead of doing those all right, we just look for data packets with
- * 0 or 1 bytes of padding. If you want to look at other packets, that
- * will require a lot more hacking.
- *
- * To add support for filtering on DECNET "areas" (network numbers)
- * one would want to add a "mask" argument to this routine. That would
- * make the filter even more inefficient, although one could be clever
- * and not generate masking instructions if the mask is 0xFFFF.
+ * Modify "index" to use the value stored into its register as an
+ * offset relative to the beginning of the header for the protocol
+ * "proto", and allocate a register and put an item "size" bytes long
+ * (1, 2, or 4) at that offset into that register, making it the register
+ * for "index".
*/
-static struct block *
-gen_dnhostop(addr, dir, base_off)
- bpf_u_int32 addr;
- int dir;
- u_int base_off;
+struct arth *
+gen_load(proto, inst, size)
+ int proto;
+ struct arth *inst;
+ int size;
{
- struct block *b0, *b1, *b2, *tmp;
- u_int offset_lh; /* offset if long header is received */
- u_int offset_sh; /* offset if short header is received */
+ struct slist *s, *tmp;
+ struct block *b;
+ int regno = alloc_reg();
- switch (dir) {
+ free_reg(inst->regno);
+ switch (size) {
- case Q_DST:
- offset_sh = 1; /* follows flags */
- offset_lh = 7; /* flgs,darea,dsubarea,HIORD */
+ default:
+ bpf_error("data size must be 1, 2, or 4");
+
+ case 1:
+ size = BPF_B;
break;
- case Q_SRC:
- offset_sh = 3; /* follows flags, dstnode */
- offset_lh = 15; /* flgs,darea,dsubarea,did,sarea,ssub,HIORD */
+ case 2:
+ size = BPF_H;
break;
- case Q_AND:
- /* Inefficient because we do our Calvinball dance twice */
- b0 = gen_dnhostop(addr, Q_SRC, base_off);
- b1 = gen_dnhostop(addr, Q_DST, base_off);
- gen_and(b0, b1);
- return b1;
+ case 4:
+ size = BPF_W;
+ break;
+ }
+ switch (proto) {
+ default:
+ bpf_error("unsupported index operation");
- case Q_OR:
- case Q_DEFAULT:
- /* Inefficient because we do our Calvinball dance twice */
- b0 = gen_dnhostop(addr, Q_SRC, base_off);
- b1 = gen_dnhostop(addr, Q_DST, base_off);
- gen_or(b0, b1);
- return b1;
+ case Q_RADIO:
+ /*
+ * The offset is relative to the beginning of the packet
+ * data, if we have a radio header. (If we don't, this
+ * is an error.)
+ */
+ if (linktype != DLT_IEEE802_11_RADIO_AVS &&
+ linktype != DLT_IEEE802_11_RADIO &&
+ linktype != DLT_PRISM_HEADER)
+ bpf_error("radio information not present in capture");
- default:
- abort();
- }
- b0 = gen_linktype(ETHERTYPE_DN);
- /* Check for pad = 1, long header case */
- tmp = gen_mcmp(base_off + 2, BPF_H,
- (bpf_int32)ntohs(0x0681), (bpf_int32)ntohs(0x07FF));
- b1 = gen_cmp(base_off + 2 + 1 + offset_lh,
- BPF_H, (bpf_int32)ntohs(addr));
- gen_and(tmp, b1);
- /* Check for pad = 0, long header case */
- tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7);
- b2 = gen_cmp(base_off + 2 + offset_lh, BPF_H, (bpf_int32)ntohs(addr));
- gen_and(tmp, b2);
- gen_or(b2, b1);
- /* Check for pad = 1, short header case */
- tmp = gen_mcmp(base_off + 2, BPF_H,
- (bpf_int32)ntohs(0x0281), (bpf_int32)ntohs(0x07FF));
- b2 = gen_cmp(base_off + 2 + 1 + offset_sh,
- BPF_H, (bpf_int32)ntohs(addr));
- gen_and(tmp, b2);
- gen_or(b2, b1);
- /* Check for pad = 0, short header case */
- tmp = gen_mcmp(base_off + 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7);
- b2 = gen_cmp(base_off + 2 + offset_sh, BPF_H, (bpf_int32)ntohs(addr));
- gen_and(tmp, b2);
- gen_or(b2, b1);
+ /*
+ * Load into the X register the offset computed into the
+ * register specifed by "index".
+ */
+ s = xfer_to_x(inst);
- /* Combine with test for linktype */
- gen_and(b0, b1);
- return b1;
-}
+ /*
+ * Load the item at that offset.
+ */
+ tmp = new_stmt(BPF_LD|BPF_IND|size);
+ sappend(s, tmp);
+ sappend(inst->s, s);
+ break;
-static struct block *
-gen_host(addr, mask, proto, dir)
- bpf_u_int32 addr;
- bpf_u_int32 mask;
- int proto;
- int dir;
-{
- struct block *b0, *b1;
+ case Q_LINK:
+ /*
+ * The offset is relative to the beginning of
+ * the link-layer header.
+ *
+ * XXX - what about ATM LANE? Should the index be
+ * relative to the beginning of the AAL5 frame, so
+ * that 0 refers to the beginning of the LE Control
+ * field, or relative to the beginning of the LAN
+ * frame, so that 0 refers, for Ethernet LANE, to
+ * the beginning of the destination address?
+ */
+ s = gen_llprefixlen();
- switch (proto) {
+ /*
+ * If "s" is non-null, it has code to arrange that the
+ * X register contains the length of the prefix preceding
+ * the link-layer header. Add to it the offset computed
+ * into the register specified by "index", and move that
+ * into the X register. Otherwise, just load into the X
+ * register the offset computed into the register specifed
+ * by "index".
+ */
+ if (s != NULL) {
+ sappend(s, xfer_to_a(inst));
+ sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
+ sappend(s, new_stmt(BPF_MISC|BPF_TAX));
+ } else
+ s = xfer_to_x(inst);
- case Q_DEFAULT:
- b0 = gen_host(addr, mask, Q_IP, dir);
- b1 = gen_host(addr, mask, Q_ARP, dir);
- gen_or(b0, b1);
- b0 = gen_host(addr, mask, Q_RARP, dir);
- gen_or(b1, b0);
- return b0;
+ /*
+ * Load the item at the sum of the offset we've put in the
+ * X register and the offset of the start of the link
+ * layer header (which is 0 if the radio header is
+ * variable-length; that header length is what we put
+ * into the X register and then added to the index).
+ */
+ tmp = new_stmt(BPF_LD|BPF_IND|size);
+ tmp->s.k = off_ll;
+ sappend(s, tmp);
+ sappend(inst->s, s);
+ break;
case Q_IP:
- return gen_hostop(addr, mask, dir, ETHERTYPE_IP,
- off_nl + 12, off_nl + 16);
-
+ case Q_ARP:
case Q_RARP:
- return gen_hostop(addr, mask, dir, ETHERTYPE_REVARP,
- off_nl + 14, off_nl + 24);
+ case Q_ATALK:
+ case Q_DECNET:
+ case Q_SCA:
+ case Q_LAT:
+ case Q_MOPRC:
+ case Q_MOPDL:
+#ifdef INET6
+ case Q_IPV6:
+#endif
+ /*
+ * The offset is relative to the beginning of
+ * the network-layer header.
+ * XXX - are there any cases where we want
+ * off_nl_nosnap?
+ */
+ s = gen_off_macpl();
- case Q_ARP:
- return gen_hostop(addr, mask, dir, ETHERTYPE_ARP,
- off_nl + 14, off_nl + 24);
+ /*
+ * If "s" is non-null, it has code to arrange that the
+ * X register contains the offset of the MAC-layer
+ * payload. Add to it the offset computed into the
+ * register specified by "index", and move that into
+ * the X register. Otherwise, just load into the X
+ * register the offset computed into the register specifed
+ * by "index".
+ */
+ if (s != NULL) {
+ sappend(s, xfer_to_a(inst));
+ sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
+ sappend(s, new_stmt(BPF_MISC|BPF_TAX));
+ } else
+ s = xfer_to_x(inst);
- case Q_TCP:
- bpf_error("'tcp' modifier applied to host");
+ /*
+ * Load the item at the sum of the offset we've put in the
+ * X register, the offset of the start of the network
+ * layer header from the beginning of the MAC-layer
+ * payload, and the purported offset of the start of the
+ * MAC-layer payload (which might be 0 if there's a
+ * variable-length prefix before the link-layer header
+ * or the link-layer header itself is variable-length;
+ * the variable-length offset of the start of the
+ * MAC-layer payload is what we put into the X register
+ * and then added to the index).
+ */
+ tmp = new_stmt(BPF_LD|BPF_IND|size);
+ tmp->s.k = off_macpl + off_nl;
+ sappend(s, tmp);
+ sappend(inst->s, s);
- case Q_UDP:
- bpf_error("'udp' modifier applied to host");
+ /*
+ * Do the computation only if the packet contains
+ * the protocol in question.
+ */
+ b = gen_proto_abbrev(proto);
+ if (inst->b)
+ gen_and(inst->b, b);
+ inst->b = b;
+ break;
+ case Q_SCTP:
+ case Q_TCP:
+ case Q_UDP:
case Q_ICMP:
- bpf_error("'icmp' modifier applied to host");
-
case Q_IGMP:
- bpf_error("'igmp' modifier applied to host");
-
case Q_IGRP:
- bpf_error("'igrp' modifier applied to host");
-
- case Q_ATALK:
- bpf_error("ATALK host filtering not implemented");
-
- case Q_DECNET:
- return gen_dnhostop(addr, dir, off_nl);
+ case Q_PIM:
+ case Q_VRRP:
+ /*
+ * The offset is relative to the beginning of
+ * the transport-layer header.
+ *
+ * Load the X register with the length of the IPv4 header
+ * (plus the offset of the link-layer header, if it's
+ * a variable-length header), in bytes.
+ *
+ * XXX - are there any cases where we want
+ * off_nl_nosnap?
+ * XXX - we should, if we're built with
+ * IPv6 support, generate code to load either
+ * IPv4, IPv6, or both, as appropriate.
+ */
+ s = gen_loadx_iphdrlen();
- case Q_SCA:
- bpf_error("SCA host filtering not implemented");
+ /*
+ * The X register now contains the sum of the length
+ * of any variable-length header preceding the link-layer
+ * header, any variable-length link-layer header, and the
+ * length of the network-layer header.
+ *
+ * Load into the A register the offset relative to
+ * the beginning of the transport layer header,
+ * add the X register to that, move that to the
+ * X register, and load with an offset from the
+ * X register equal to the offset of the network
+ * layer header relative to the beginning of
+ * the MAC-layer payload plus the fixed-length
+ * portion of the offset of the MAC-layer payload
+ * from the beginning of the raw packet data.
+ */
+ sappend(s, xfer_to_a(inst));
+ sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
+ sappend(s, new_stmt(BPF_MISC|BPF_TAX));
+ sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size));
+ tmp->s.k = off_macpl + off_nl;
+ sappend(inst->s, s);
- case Q_LAT:
- bpf_error("LAT host filtering not implemented");
+ /*
+ * Do the computation only if the packet contains
+ * the protocol in question - which is true only
+ * if this is an IP datagram and is the first or
+ * only fragment of that datagram.
+ */
+ gen_and(gen_proto_abbrev(proto), b = gen_ipfrag());
+ if (inst->b)
+ gen_and(inst->b, b);
+#ifdef INET6
+ gen_and(gen_proto_abbrev(Q_IP), b);
+#endif
+ inst->b = b;
+ break;
+#ifdef INET6
+ case Q_ICMPV6:
+ bpf_error("IPv6 upper-layer protocol is not supported by proto[x]");
+ /*NOTREACHED*/
+#endif
+ }
+ inst->regno = regno;
+ s = new_stmt(BPF_ST);
+ s->s.k = regno;
+ sappend(inst->s, s);
- case Q_MOPDL:
- bpf_error("MOPDL host filtering not implemented");
+ return inst;
+}
- case Q_MOPRC:
- bpf_error("MOPRC host filtering not implemented");
+struct block *
+gen_relation(code, a0, a1, reversed)
+ int code;
+ struct arth *a0, *a1;
+ int reversed;
+{
+ struct slist *s0, *s1, *s2;
+ struct block *b, *tmp;
- default:
- abort();
+ s0 = xfer_to_x(a1);
+ s1 = xfer_to_a(a0);
+ if (code == BPF_JEQ) {
+ s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X);
+ b = new_block(JMP(code));
+ sappend(s1, s2);
}
- /* NOTREACHED */
-}
+ else
+ b = new_block(BPF_JMP|code|BPF_X);
+ if (reversed)
+ gen_not(b);
-static struct block *
-gen_gateway(eaddr, alist, proto, dir)
- const u_char *eaddr;
- bpf_u_int32 **alist;
- int proto;
- int dir;
-{
- struct block *b0, *b1, *tmp;
+ sappend(s0, s1);
+ sappend(a1->s, s0);
+ sappend(a0->s, a1->s);
- if (dir != 0)
- bpf_error("direction applied to 'gateway'");
+ b->stmts = a0->s;
- switch (proto) {
- case Q_DEFAULT:
- case Q_IP:
- case Q_ARP:
- case Q_RARP:
- if (linktype == DLT_EN10MB)
- b0 = gen_ehostop(eaddr, Q_OR);
- else if (linktype == DLT_FDDI)
- b0 = gen_fhostop(eaddr, Q_OR);
- else
- bpf_error(
- "'gateway' supported only on ethernet or FDDI");
+ free_reg(a0->regno);
+ free_reg(a1->regno);
- b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR);
- while (*alist) {
- tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR);
- gen_or(b1, tmp);
- b1 = tmp;
+ /* 'and' together protocol checks */
+ if (a0->b) {
+ if (a1->b) {
+ gen_and(a0->b, tmp = a1->b);
}
- gen_not(b1);
- gen_and(b0, b1);
- return b1;
- }
- bpf_error("illegal modifier of 'gateway'");
- /* NOTREACHED */
+ else
+ tmp = a0->b;
+ } else
+ tmp = a1->b;
+
+ if (tmp)
+ gen_and(tmp, b);
+
+ return b;
}
-struct block *
-gen_proto_abbrev(proto)
- int proto;
+struct arth *
+gen_loadlen()
{
- struct block *b0, *b1;
+ int regno = alloc_reg();
+ struct arth *a = (struct arth *)newchunk(sizeof(*a));
+ struct slist *s;
- switch (proto) {
+ s = new_stmt(BPF_LD|BPF_LEN);
+ s->next = new_stmt(BPF_ST);
+ s->next->s.k = regno;
+ a->s = s;
+ a->regno = regno;
- case Q_TCP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)IPPROTO_TCP);
- gen_and(b0, b1);
- break;
+ return a;
+}
- case Q_UDP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)IPPROTO_UDP);
- gen_and(b0, b1);
- break;
+struct arth *
+gen_loadi(val)
+ int val;
+{
+ struct arth *a;
+ struct slist *s;
+ int reg;
- case Q_ICMP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)IPPROTO_ICMP);
- gen_and(b0, b1);
- break;
+ a = (struct arth *)newchunk(sizeof(*a));
- case Q_IGMP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)2);
- gen_and(b0, b1);
- break;
+ reg = alloc_reg();
-#ifndef IPPROTO_IGRP
-#define IPPROTO_IGRP 9
-#endif
- case Q_IGRP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (long)IPPROTO_IGRP);
- gen_and(b0, b1);
- break;
+ s = new_stmt(BPF_LD|BPF_IMM);
+ s->s.k = val;
+ s->next = new_stmt(BPF_ST);
+ s->next->s.k = reg;
+ a->s = s;
+ a->regno = reg;
- case Q_IP:
- b1 = gen_linktype(ETHERTYPE_IP);
- break;
+ return a;
+}
- case Q_ARP:
- b1 = gen_linktype(ETHERTYPE_ARP);
- break;
+struct arth *
+gen_neg(a)
+ struct arth *a;
+{
+ struct slist *s;
- case Q_RARP:
- b1 = gen_linktype(ETHERTYPE_REVARP);
- break;
+ s = xfer_to_a(a);
+ sappend(a->s, s);
+ s = new_stmt(BPF_ALU|BPF_NEG);
+ s->s.k = 0;
+ sappend(a->s, s);
+ s = new_stmt(BPF_ST);
+ s->s.k = a->regno;
+ sappend(a->s, s);
- case Q_LINK:
- bpf_error("link layer applied in wrong context");
+ return a;
+}
- case Q_ATALK:
- b1 = gen_linktype(ETHERTYPE_ATALK);
- break;
+struct arth *
+gen_arth(code, a0, a1)
+ int code;
+ struct arth *a0, *a1;
+{
+ struct slist *s0, *s1, *s2;
- case Q_DECNET:
- b1 = gen_linktype(ETHERTYPE_DN);
- break;
+ s0 = xfer_to_x(a1);
+ s1 = xfer_to_a(a0);
+ s2 = new_stmt(BPF_ALU|BPF_X|code);
- case Q_SCA:
- b1 = gen_linktype(ETHERTYPE_SCA);
- break;
+ sappend(s1, s2);
+ sappend(s0, s1);
+ sappend(a1->s, s0);
+ sappend(a0->s, a1->s);
- case Q_LAT:
- b1 = gen_linktype(ETHERTYPE_LAT);
- break;
+ free_reg(a0->regno);
+ free_reg(a1->regno);
- case Q_MOPDL:
- b1 = gen_linktype(ETHERTYPE_MOPDL);
- break;
+ s0 = new_stmt(BPF_ST);
+ a0->regno = s0->s.k = alloc_reg();
+ sappend(a0->s, s0);
- case Q_MOPRC:
- b1 = gen_linktype(ETHERTYPE_MOPRC);
- break;
+ return a0;
+}
+
+/*
+ * Here we handle simple allocation of the scratch registers.
+ * If too many registers are alloc'd, the allocator punts.
+ */
+static int regused[BPF_MEMWORDS];
+static int curreg;
- default:
- abort();
- }
- return b1;
+/*
+ * Initialize the table of used registers and the current register.
+ */
+static void
+init_regs()
+{
+ curreg = 0;
+ memset(regused, 0, sizeof regused);
}
-static struct block *
-gen_ipfrag()
+/*
+ * Return the next free register.
+ */
+static int
+alloc_reg()
{
- struct slist *s;
- struct block *b;
+ int n = BPF_MEMWORDS;
- /* not ip frag */
- s = new_stmt(BPF_LD|BPF_H|BPF_ABS);
- s->s.k = off_nl + 6;
- b = new_block(JMP(BPF_JSET));
- b->s.k = 0x1fff;
- b->stmts = s;
- gen_not(b);
+ while (--n >= 0) {
+ if (regused[curreg])
+ curreg = (curreg + 1) % BPF_MEMWORDS;
+ else {
+ regused[curreg] = 1;
+ return curreg;
+ }
+ }
+ bpf_error("too many registers needed to evaluate expression");
+ /* NOTREACHED */
+ return 0;
+}
- return b;
+/*
+ * Return a register to the table so it can
+ * be used later.
+ */
+static void
+free_reg(n)
+ int n;
+{
+ regused[n] = 0;
}
static struct block *
-gen_portatom(off, v)
- int off;
- bpf_int32 v;
+gen_len(jmp, n)
+ int jmp, n;
{
struct slist *s;
struct block *b;
- s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
- s->s.k = off_nl;
-
- s->next = new_stmt(BPF_LD|BPF_IND|BPF_H);
- s->next->s.k = off_nl + off;
-
- b = new_block(JMP(BPF_JEQ));
+ s = new_stmt(BPF_LD|BPF_LEN);
+ b = new_block(JMP(jmp));
b->stmts = s;
- b->s.k = v;
+ b->s.k = n;
return b;
}
struct block *
-gen_portop(port, proto, dir)
- int port, proto, dir;
+gen_greater(n)
+ int n;
{
- struct block *b0, *b1, *tmp;
-
- /* ip proto 'proto' */
- tmp = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)proto);
- b0 = gen_ipfrag();
- gen_and(tmp, b0);
+ return gen_len(BPF_JGE, n);
+}
- switch (dir) {
- case Q_SRC:
- b1 = gen_portatom(0, (bpf_int32)port);
- break;
+/*
+ * Actually, this is less than or equal.
+ */
+struct block *
+gen_less(n)
+ int n;
+{
+ struct block *b;
- case Q_DST:
- b1 = gen_portatom(2, (bpf_int32)port);
- break;
+ b = gen_len(BPF_JGT, n);
+ gen_not(b);
- case Q_OR:
- case Q_DEFAULT:
- tmp = gen_portatom(0, (bpf_int32)port);
- b1 = gen_portatom(2, (bpf_int32)port);
- gen_or(tmp, b1);
- break;
+ return b;
+}
- case Q_AND:
- tmp = gen_portatom(0, (bpf_int32)port);
- b1 = gen_portatom(2, (bpf_int32)port);
- gen_and(tmp, b1);
- break;
+/*
+ * This is for "byte {idx} {op} {val}"; "idx" is treated as relative to
+ * the beginning of the link-layer header.
+ * XXX - that means you can't test values in the radiotap header, but
+ * as that header is difficult if not impossible to parse generally
+ * without a loop, that might not be a severe problem. A new keyword
+ * "radio" could be added for that, although what you'd really want
+ * would be a way of testing particular radio header values, which
+ * would generate code appropriate to the radio header in question.
+ */
+struct block *
+gen_byteop(op, idx, val)
+ int op, idx, val;
+{
+ struct block *b;
+ struct slist *s;
+ switch (op) {
default:
abort();
- }
- gen_and(b0, b1);
- return b1;
-}
+ case '=':
+ return gen_cmp(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
-static struct block *
-gen_port(port, ip_proto, dir)
- int port;
- int ip_proto;
- int dir;
-{
- struct block *b0, *b1, *tmp;
+ case '<':
+ b = gen_cmp_lt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
+ return b;
- /* ether proto ip */
- b0 = gen_linktype(ETHERTYPE_IP);
+ case '>':
+ b = gen_cmp_gt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
+ return b;
- switch (ip_proto) {
- case IPPROTO_UDP:
- case IPPROTO_TCP:
- b1 = gen_portop(port, ip_proto, dir);
+ case '|':
+ s = new_stmt(BPF_ALU|BPF_OR|BPF_K);
break;
- case PROTO_UNDEF:
- tmp = gen_portop(port, IPPROTO_TCP, dir);
- b1 = gen_portop(port, IPPROTO_UDP, dir);
- gen_or(tmp, b1);
+ case '&':
+ s = new_stmt(BPF_ALU|BPF_AND|BPF_K);
break;
-
- default:
- abort();
}
- gen_and(b0, b1);
- return b1;
+ s->s.k = val;
+ b = new_block(JMP(BPF_JEQ));
+ b->stmts = s;
+ gen_not(b);
+
+ return b;
}
-static int
-lookup_proto(name, proto)
- register const char *name;
- register int proto;
+static u_char abroadcast[] = { 0x0 };
+
+struct block *
+gen_broadcast(proto)
+ int proto;
{
- register int v;
+ bpf_u_int32 hostmask;
+ struct block *b0, *b1, *b2;
+ static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
switch (proto) {
case Q_DEFAULT:
- case Q_IP:
- v = pcap_nametoproto(name);
- if (v == PROTO_UNDEF)
- bpf_error("unknown ip proto '%s'", name);
- break;
-
case Q_LINK:
- /* XXX should look up h/w protocol type based on linktype */
- v = pcap_nametoeproto(name);
- if (v == PROTO_UNDEF)
- bpf_error("unknown ether proto '%s'", name);
+ switch (linktype) {
+ case DLT_ARCNET:
+ case DLT_ARCNET_LINUX:
+ return gen_ahostop(abroadcast, Q_DST);
+ case DLT_EN10MB:
+ return gen_ehostop(ebroadcast, Q_DST);
+ case DLT_FDDI:
+ return gen_fhostop(ebroadcast, Q_DST);
+ case DLT_IEEE802:
+ return gen_thostop(ebroadcast, Q_DST);
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
+ return gen_wlanhostop(ebroadcast, Q_DST);
+ case DLT_IP_OVER_FC:
+ return gen_ipfchostop(ebroadcast, Q_DST);
+ case DLT_SUNATM:
+ if (is_lane) {
+ /*
+ * Check that the packet doesn't begin with an
+ * LE Control marker. (We've already generated
+ * a test for LANE.)
+ */
+ b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS,
+ BPF_H, 0xFF00);
+ gen_not(b1);
+
+ /*
+ * Now check the MAC address.
+ */
+ b0 = gen_ehostop(ebroadcast, Q_DST);
+ gen_and(b1, b0);
+ return b0;
+ }
+ break;
+ default:
+ bpf_error("not a broadcast link");
+ }
break;
- default:
- v = PROTO_UNDEF;
- break;
+ case Q_IP:
+ b0 = gen_linktype(ETHERTYPE_IP);
+ hostmask = ~netmask;
+ b1 = gen_mcmp(OR_NET, 16, BPF_W, (bpf_int32)0, hostmask);
+ b2 = gen_mcmp(OR_NET, 16, BPF_W,
+ (bpf_int32)(~0 & hostmask), hostmask);
+ gen_or(b1, b2);
+ gen_and(b0, b2);
+ return b2;
}
- return v;
+ bpf_error("only link-layer/IP broadcast filters supported");
+ /* NOTREACHED */
+ return NULL;
}
+/*
+ * Generate code to test the low-order bit of a MAC address (that's
+ * the bottom bit of the *first* byte).
+ */
static struct block *
-gen_proto(v, proto, dir)
- int v;
- int proto;
- int dir;
+gen_mac_multicast(offset)
+ int offset;
{
- struct block *b0, *b1;
+ register struct block *b0;
+ register struct slist *s;
- if (dir != Q_DEFAULT)
- bpf_error("direction applied to 'proto'");
+ /* link[offset] & 1 != 0 */
+ s = gen_load_a(OR_LINK, offset, BPF_B);
+ b0 = new_block(JMP(BPF_JSET));
+ b0->s.k = 1;
+ b0->stmts = s;
+ return b0;
+}
- switch (proto) {
- case Q_DEFAULT:
- case Q_IP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 9, BPF_B, (bpf_int32)v);
- gen_and(b0, b1);
- return b1;
+struct block *
+gen_multicast(proto)
+ int proto;
+{
+ register struct block *b0, *b1, *b2;
+ register struct slist *s;
- case Q_ARP:
- bpf_error("arp does not encapsulate another protocol");
- /* NOTREACHED */
+ switch (proto) {
- case Q_RARP:
- bpf_error("rarp does not encapsulate another protocol");
- /* NOTREACHED */
+ case Q_DEFAULT:
+ case Q_LINK:
+ switch (linktype) {
+ case DLT_ARCNET:
+ case DLT_ARCNET_LINUX:
+ /* all ARCnet multicasts use the same address */
+ return gen_ahostop(abroadcast, Q_DST);
+ case DLT_EN10MB:
+ /* ether[0] & 1 != 0 */
+ return gen_mac_multicast(0);
+ case DLT_FDDI:
+ /*
+ * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX
+ *
+ * XXX - was that referring to bit-order issues?
+ */
+ /* fddi[1] & 1 != 0 */
+ return gen_mac_multicast(1);
+ case DLT_IEEE802:
+ /* tr[2] & 1 != 0 */
+ return gen_mac_multicast(2);
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
+ /*
+ * Oh, yuk.
+ *
+ * For control frames, there is no DA.
+ *
+ * For management frames, DA is at an
+ * offset of 4 from the beginning of
+ * the packet.
+ *
+ * For data frames, DA is at an offset
+ * of 4 from the beginning of the packet
+ * if To DS is clear and at an offset of
+ * 16 from the beginning of the packet
+ * if To DS is set.
+ */
- case Q_ATALK:
- bpf_error("atalk encapsulation is not specifiable");
- /* NOTREACHED */
+ /*
+ * Generate the tests to be done for data frames.
+ *
+ * First, check for To DS set, i.e. "link[1] & 0x01".
+ */
+ s = gen_load_a(OR_LINK, 1, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x01; /* To DS */
+ b1->stmts = s;
- case Q_DECNET:
- bpf_error("decnet encapsulation is not specifiable");
- /* NOTREACHED */
+ /*
+ * If To DS is set, the DA is at 16.
+ */
+ b0 = gen_mac_multicast(16);
+ gen_and(b1, b0);
- case Q_SCA:
- bpf_error("sca does not encapsulate another protocol");
- /* NOTREACHED */
+ /*
+ * Now, check for To DS not set, i.e. check
+ * "!(link[1] & 0x01)".
+ */
+ s = gen_load_a(OR_LINK, 1, BPF_B);
+ b2 = new_block(JMP(BPF_JSET));
+ b2->s.k = 0x01; /* To DS */
+ b2->stmts = s;
+ gen_not(b2);
- case Q_LAT:
- bpf_error("lat does not encapsulate another protocol");
- /* NOTREACHED */
+ /*
+ * If To DS is not set, the DA is at 4.
+ */
+ b1 = gen_mac_multicast(4);
+ gen_and(b2, b1);
- case Q_MOPRC:
- bpf_error("moprc does not encapsulate another protocol");
- /* NOTREACHED */
+ /*
+ * Now OR together the last two checks. That gives
+ * the complete set of checks for data frames.
+ */
+ gen_or(b1, b0);
- case Q_MOPDL:
- bpf_error("mopdl does not encapsulate another protocol");
- /* NOTREACHED */
+ /*
+ * Now check for a data frame.
+ * I.e, check "link[0] & 0x08".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x08;
+ b1->stmts = s;
- case Q_LINK:
- return gen_linktype(v);
+ /*
+ * AND that with the checks done for data frames.
+ */
+ gen_and(b1, b0);
- case Q_UDP:
- bpf_error("'udp proto' is bogus");
- /* NOTREACHED */
+ /*
+ * If the high-order bit of the type value is 0, this
+ * is a management frame.
+ * I.e, check "!(link[0] & 0x08)".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b2 = new_block(JMP(BPF_JSET));
+ b2->s.k = 0x08;
+ b2->stmts = s;
+ gen_not(b2);
- case Q_TCP:
- bpf_error("'tcp proto' is bogus");
- /* NOTREACHED */
+ /*
+ * For management frames, the DA is at 4.
+ */
+ b1 = gen_mac_multicast(4);
+ gen_and(b2, b1);
- case Q_ICMP:
- bpf_error("'icmp proto' is bogus");
- /* NOTREACHED */
+ /*
+ * OR that with the checks done for data frames.
+ * That gives the checks done for management and
+ * data frames.
+ */
+ gen_or(b1, b0);
- case Q_IGMP:
- bpf_error("'igmp proto' is bogus");
- /* NOTREACHED */
+ /*
+ * If the low-order bit of the type value is 1,
+ * this is either a control frame or a frame
+ * with a reserved type, and thus not a
+ * frame with an SA.
+ *
+ * I.e., check "!(link[0] & 0x04)".
+ */
+ s = gen_load_a(OR_LINK, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x04;
+ b1->stmts = s;
+ gen_not(b1);
- case Q_IGRP:
- bpf_error("'igrp proto' is bogus");
- /* NOTREACHED */
+ /*
+ * AND that with the checks for data and management
+ * frames.
+ */
+ gen_and(b1, b0);
+ return b0;
+ case DLT_IP_OVER_FC:
+ b0 = gen_mac_multicast(2);
+ return b0;
+ case DLT_SUNATM:
+ if (is_lane) {
+ /*
+ * Check that the packet doesn't begin with an
+ * LE Control marker. (We've already generated
+ * a test for LANE.)
+ */
+ b1 = gen_cmp(OR_LINK, SUNATM_PKT_BEGIN_POS,
+ BPF_H, 0xFF00);
+ gen_not(b1);
+
+ /* ether[off_mac] & 1 != 0 */
+ b0 = gen_mac_multicast(off_mac);
+ gen_and(b1, b0);
+ return b0;
+ }
+ break;
+ default:
+ break;
+ }
+ /* Link not known to support multicasts */
+ break;
- default:
- abort();
- /* NOTREACHED */
+ case Q_IP:
+ b0 = gen_linktype(ETHERTYPE_IP);
+ b1 = gen_cmp_ge(OR_NET, 16, BPF_B, (bpf_int32)224);
+ gen_and(b0, b1);
+ return b1;
+
+#ifdef INET6
+ case Q_IPV6:
+ b0 = gen_linktype(ETHERTYPE_IPV6);
+ b1 = gen_cmp(OR_NET, 24, BPF_B, (bpf_int32)255);
+ gen_and(b0, b1);
+ return b1;
+#endif /* INET6 */
}
+ bpf_error("link-layer multicast filters supported only on ethernet/FDDI/token ring/ARCNET/802.11/ATM LANE/Fibre Channel");
/* NOTREACHED */
+ return NULL;
}
+/*
+ * generate command for inbound/outbound. It's here so we can
+ * make it link-type specific. 'dir' = 0 implies "inbound",
+ * = 1 implies "outbound".
+ */
struct block *
-gen_scode(name, q)
- register const char *name;
- struct qual q;
+gen_inbound(dir)
+ int dir;
{
- int proto = q.proto;
- int dir = q.dir;
- int tproto;
- u_char *eaddr;
- bpf_u_int32 mask, addr, **alist;
- struct block *b, *tmp;
- int port, real_proto;
-
- switch (q.addr) {
-
- case Q_NET:
- addr = pcap_nametonetaddr(name);
- if (addr == 0)
- bpf_error("unknown network '%s'", name);
- /* Left justify network addr and calculate its network mask */
- mask = 0xffffffff;
- while (addr && (addr & 0xff000000) == 0) {
- addr <<= 8;
- mask <<= 8;
- }
- return gen_host(addr, mask, proto, dir);
-
- case Q_DEFAULT:
- case Q_HOST:
- if (proto == Q_LINK) {
- switch (linktype) {
-
- case DLT_EN10MB:
- eaddr = pcap_ether_hostton(name);
- if (eaddr == NULL)
- bpf_error(
- "unknown ether host '%s'", name);
- return gen_ehostop(eaddr, dir);
+ register struct block *b0;
- case DLT_FDDI:
- eaddr = pcap_ether_hostton(name);
- if (eaddr == NULL)
- bpf_error(
- "unknown FDDI host '%s'", name);
- return gen_fhostop(eaddr, dir);
+ /*
+ * Only some data link types support inbound/outbound qualifiers.
+ */
+ switch (linktype) {
+ case DLT_SLIP:
+ b0 = gen_relation(BPF_JEQ,
+ gen_load(Q_LINK, gen_loadi(0), 1),
+ gen_loadi(0),
+ dir);
+ break;
- default:
- bpf_error(
- "only ethernet/FDDI supports link-level host name");
- break;
- }
- } else if (proto == Q_DECNET) {
- unsigned short dn_addr = __pcap_nametodnaddr(name);
+ case DLT_LINUX_SLL:
+ if (dir) {
/*
- * I don't think DECNET hosts can be multihomed, so
- * there is no need to build up a list of addresses
+ * Match packets sent by this machine.
*/
- return (gen_host(dn_addr, 0, proto, dir));
+ b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_OUTGOING);
} else {
- alist = pcap_nametoaddr(name);
- if (alist == NULL || *alist == NULL)
- bpf_error("unknown host '%s'", name);
- tproto = proto;
- if (off_linktype == -1 && tproto == Q_DEFAULT)
- tproto = Q_IP;
- b = gen_host(**alist++, 0xffffffff, tproto, dir);
- while (*alist) {
- tmp = gen_host(**alist++, 0xffffffff,
- tproto, dir);
- gen_or(b, tmp);
- b = tmp;
- }
- return b;
- }
-
- case Q_PORT:
- if (proto != Q_DEFAULT && proto != Q_UDP && proto != Q_TCP)
- bpf_error("illegal qualifier of 'port'");
- if (pcap_nametoport(name, &port, &real_proto) == 0)
- bpf_error("unknown port '%s'", name);
- if (proto == Q_UDP) {
- if (real_proto == IPPROTO_TCP)
- bpf_error("port '%s' is tcp", name);
- else
- /* override PROTO_UNDEF */
- real_proto = IPPROTO_UDP;
- }
- if (proto == Q_TCP) {
- if (real_proto == IPPROTO_UDP)
- bpf_error("port '%s' is udp", name);
- else
- /* override PROTO_UNDEF */
- real_proto = IPPROTO_TCP;
+ /*
+ * Match packets sent to this machine.
+ * (No broadcast or multicast packets, or
+ * packets sent to some other machine and
+ * received promiscuously.)
+ *
+ * XXX - packets sent to other machines probably
+ * shouldn't be matched, but what about broadcast
+ * or multicast packets we received?
+ */
+ b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_HOST);
}
- return gen_port(port, real_proto, dir);
+ break;
- case Q_GATEWAY:
- eaddr = pcap_ether_hostton(name);
- if (eaddr == NULL)
- bpf_error("unknown ether host: %s", name);
+#ifdef HAVE_NET_PFVAR_H
+ case DLT_PFLOG:
+ b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, dir), BPF_B,
+ (bpf_int32)((dir == 0) ? PF_IN : PF_OUT));
+ break;
+#endif
- alist = pcap_nametoaddr(name);
- if (alist == NULL || *alist == NULL)
- bpf_error("unknown host '%s'", name);
- return gen_gateway(eaddr, alist, proto, dir);
+ case DLT_PPP_PPPD:
+ if (dir) {
+ /* match outgoing packets */
+ b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_OUT);
+ } else {
+ /* match incoming packets */
+ b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_IN);
+ }
+ break;
- case Q_PROTO:
- real_proto = lookup_proto(name, proto);
- if (real_proto >= 0)
- return gen_proto(real_proto, proto, dir);
- else
- bpf_error("unknown protocol: %s", name);
+ case DLT_JUNIPER_MFR:
+ case DLT_JUNIPER_MLFR:
+ case DLT_JUNIPER_MLPPP:
+ case DLT_JUNIPER_ATM1:
+ case DLT_JUNIPER_ATM2:
+ case DLT_JUNIPER_PPPOE:
+ case DLT_JUNIPER_PPPOE_ATM:
+ case DLT_JUNIPER_GGSN:
+ case DLT_JUNIPER_ES:
+ case DLT_JUNIPER_MONITOR:
+ case DLT_JUNIPER_SERVICES:
+ case DLT_JUNIPER_ETHER:
+ case DLT_JUNIPER_PPP:
+ case DLT_JUNIPER_FRELAY:
+ case DLT_JUNIPER_CHDLC:
+ case DLT_JUNIPER_VP:
+ case DLT_JUNIPER_ST:
+ case DLT_JUNIPER_ISM:
+ /* juniper flags (including direction) are stored
+ * the byte after the 3-byte magic number */
+ if (dir) {
+ /* match outgoing packets */
+ b0 = gen_mcmp(OR_LINK, 3, BPF_B, 0, 0x01);
+ } else {
+ /* match incoming packets */
+ b0 = gen_mcmp(OR_LINK, 3, BPF_B, 1, 0x01);
+ }
+ break;
- case Q_UNDEF:
- syntax();
+ default:
+ bpf_error("inbound/outbound not supported on linktype %d",
+ linktype);
+ b0 = NULL;
/* NOTREACHED */
}
- abort();
- /* NOTREACHED */
+ return (b0);
}
+#ifdef HAVE_NET_PFVAR_H
+/* PF firewall log matched interface */
struct block *
-gen_mcode(s1, s2, masklen, q)
- register const char *s1, *s2;
- register int masklen;
- struct qual q;
+gen_pf_ifname(const char *ifname)
{
- register int nlen, mlen;
- bpf_u_int32 n, m;
-
- nlen = __pcap_atoin(s1, &n);
- /* Promote short ipaddr */
- n <<= 32 - nlen;
+ struct block *b0;
+ u_int len, off;
- if (s2 != NULL) {
- mlen = __pcap_atoin(s2, &m);
- /* Promote short ipaddr */
- m <<= 32 - mlen;
- if ((n & ~m) != 0)
- bpf_error("non-network bits set in \"%s mask %s\"",
- s1, s2);
- } else {
- /* Convert mask len to mask */
- if (masklen > 32)
- bpf_error("mask length must be <= 32");
- m = 0xffffffff << (32 - masklen);
- if ((n & ~m) != 0)
- bpf_error("non-network bits set in \"%s/%d\"",
- s1, masklen);
+ if (linktype != DLT_PFLOG) {
+ bpf_error("ifname supported only on PF linktype");
+ /* NOTREACHED */
+ }
+ len = sizeof(((struct pfloghdr *)0)->ifname);
+ off = offsetof(struct pfloghdr, ifname);
+ if (strlen(ifname) >= len) {
+ bpf_error("ifname interface names can only be %d characters",
+ len-1);
+ /* NOTREACHED */
}
+ b0 = gen_bcmp(OR_LINK, off, strlen(ifname), (const u_char *)ifname);
+ return (b0);
+}
- switch (q.addr) {
+/* PF firewall log ruleset name */
+struct block *
+gen_pf_ruleset(char *ruleset)
+{
+ struct block *b0;
- case Q_NET:
- return gen_host(n, m, q.proto, q.dir);
+ if (linktype != DLT_PFLOG) {
+ bpf_error("ruleset supported only on PF linktype");
+ /* NOTREACHED */
+ }
- default:
- bpf_error("Mask syntax for networks only");
+ if (strlen(ruleset) >= sizeof(((struct pfloghdr *)0)->ruleset)) {
+ bpf_error("ruleset names can only be %ld characters",
+ (long)(sizeof(((struct pfloghdr *)0)->ruleset) - 1));
/* NOTREACHED */
}
+
+ b0 = gen_bcmp(OR_LINK, offsetof(struct pfloghdr, ruleset),
+ strlen(ruleset), (const u_char *)ruleset);
+ return (b0);
}
+/* PF firewall log rule number */
struct block *
-gen_ncode(s, v, q)
- register const char *s;
- bpf_u_int32 v;
- struct qual q;
+gen_pf_rnr(int rnr)
{
- bpf_u_int32 mask;
- int proto = q.proto;
- int dir = q.dir;
- register int vlen;
-
- if (s == NULL)
- vlen = 32;
- else if (q.proto == Q_DECNET)
- vlen = __pcap_atodn(s, &v);
- else
- vlen = __pcap_atoin(s, &v);
-
- switch (q.addr) {
+ struct block *b0;
- case Q_DEFAULT:
- case Q_HOST:
- case Q_NET:
- if (proto == Q_DECNET)
- return gen_host(v, 0, proto, dir);
- else if (proto == Q_LINK) {
- bpf_error("illegal link layer address");
- } else {
- mask = 0xffffffff;
- if (s == NULL && q.addr == Q_NET) {
- /* Promote short net number */
- while (v && (v & 0xff000000) == 0) {
- v <<= 8;
- mask <<= 8;
- }
- } else {
- /* Promote short ipaddr */
- v <<= 32 - vlen;
- mask <<= 32 - vlen;
- }
- return gen_host(v, mask, proto, dir);
- }
+ if (linktype != DLT_PFLOG) {
+ bpf_error("rnr supported only on PF linktype");
+ /* NOTREACHED */
+ }
- case Q_PORT:
- if (proto == Q_UDP)
- proto = IPPROTO_UDP;
- else if (proto == Q_TCP)
- proto = IPPROTO_TCP;
- else if (proto == Q_DEFAULT)
- proto = PROTO_UNDEF;
- else
- bpf_error("illegal qualifier of 'port'");
+ b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, rulenr), BPF_W,
+ (bpf_int32)rnr);
+ return (b0);
+}
- return gen_port((int)v, proto, dir);
+/* PF firewall log sub-rule number */
+struct block *
+gen_pf_srnr(int srnr)
+{
+ struct block *b0;
- case Q_GATEWAY:
- bpf_error("'gateway' requires a name");
+ if (linktype != DLT_PFLOG) {
+ bpf_error("srnr supported only on PF linktype");
/* NOTREACHED */
+ }
- case Q_PROTO:
- return gen_proto((int)v, proto, dir);
+ b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, subrulenr), BPF_W,
+ (bpf_int32)srnr);
+ return (b0);
+}
- case Q_UNDEF:
- syntax();
- /* NOTREACHED */
+/* PF firewall log reason code */
+struct block *
+gen_pf_reason(int reason)
+{
+ struct block *b0;
- default:
- abort();
+ if (linktype != DLT_PFLOG) {
+ bpf_error("reason supported only on PF linktype");
/* NOTREACHED */
}
- /* NOTREACHED */
+
+ b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, reason), BPF_B,
+ (bpf_int32)reason);
+ return (b0);
}
+/* PF firewall log action */
struct block *
-gen_ecode(eaddr, q)
- register const u_char *eaddr;
- struct qual q;
+gen_pf_action(int action)
{
- if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
- if (linktype == DLT_EN10MB)
- return gen_ehostop(eaddr, (int)q.dir);
- if (linktype == DLT_FDDI)
- return gen_fhostop(eaddr, (int)q.dir);
+ struct block *b0;
+
+ if (linktype != DLT_PFLOG) {
+ bpf_error("action supported only on PF linktype");
+ /* NOTREACHED */
}
- bpf_error("ethernet address used in non-ether expression");
+
+ b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, action), BPF_B,
+ (bpf_int32)action);
+ return (b0);
+}
+#else /* !HAVE_NET_PFVAR_H */
+struct block *
+gen_pf_ifname(const char *ifname)
+{
+ bpf_error("libpcap was compiled without pf support");
/* NOTREACHED */
+ return (NULL);
}
-void
-sappend(s0, s1)
- struct slist *s0, *s1;
+struct block *
+gen_pf_ruleset(char *ruleset)
{
- /*
- * This is definitely not the best way to do this, but the
- * lists will rarely get long.
- */
- while (s0->next)
- s0 = s0->next;
- s0->next = s1;
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
}
-static struct slist *
-xfer_to_x(a)
- struct arth *a;
+struct block *
+gen_pf_rnr(int rnr)
{
- struct slist *s;
-
- s = new_stmt(BPF_LDX|BPF_MEM);
- s->s.k = a->regno;
- return s;
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
}
-static struct slist *
-xfer_to_a(a)
- struct arth *a;
+struct block *
+gen_pf_srnr(int srnr)
{
- struct slist *s;
-
- s = new_stmt(BPF_LD|BPF_MEM);
- s->s.k = a->regno;
- return s;
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
}
-struct arth *
-gen_load(proto, index, size)
- int proto;
- struct arth *index;
- int size;
+struct block *
+gen_pf_reason(int reason)
{
- struct slist *s, *tmp;
- struct block *b;
- int regno = alloc_reg();
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
+}
- free_reg(index->regno);
- switch (size) {
+struct block *
+gen_pf_action(int action)
+{
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
+}
+#endif /* HAVE_NET_PFVAR_H */
- default:
- bpf_error("data size must be 1, 2, or 4");
+/* IEEE 802.11 wireless header */
+struct block *
+gen_p80211_type(int type, int mask)
+{
+ struct block *b0;
- case 1:
- size = BPF_B;
- break;
+ switch (linktype) {
- case 2:
- size = BPF_H;
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ b0 = gen_mcmp(OR_LINK, 0, BPF_B, (bpf_int32)type,
+ (bpf_int32)mask);
break;
- case 4:
- size = BPF_W;
- break;
- }
- switch (proto) {
default:
- bpf_error("unsupported index operation");
-
- case Q_LINK:
- s = xfer_to_x(index);
- tmp = new_stmt(BPF_LD|BPF_IND|size);
- sappend(s, tmp);
- sappend(index->s, s);
- break;
-
- case Q_IP:
- case Q_ARP:
- case Q_RARP:
- case Q_ATALK:
- case Q_DECNET:
- case Q_SCA:
- case Q_LAT:
- case Q_MOPRC:
- case Q_MOPDL:
- /* XXX Note that we assume a fixed link link header here. */
- s = xfer_to_x(index);
- tmp = new_stmt(BPF_LD|BPF_IND|size);
- tmp->s.k = off_nl;
- sappend(s, tmp);
- sappend(index->s, s);
-
- b = gen_proto_abbrev(proto);
- if (index->b)
- gen_and(index->b, b);
- index->b = b;
- break;
-
- case Q_TCP:
- case Q_UDP:
- case Q_ICMP:
- case Q_IGMP:
- case Q_IGRP:
- s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
- s->s.k = off_nl;
- sappend(s, xfer_to_a(index));
- sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X));
- sappend(s, new_stmt(BPF_MISC|BPF_TAX));
- sappend(s, tmp = new_stmt(BPF_LD|BPF_IND|size));
- tmp->s.k = off_nl;
- sappend(index->s, s);
-
- gen_and(gen_proto_abbrev(proto), b = gen_ipfrag());
- if (index->b)
- gen_and(index->b, b);
- index->b = b;
- break;
+ bpf_error("802.11 link-layer types supported only on 802.11");
+ /* NOTREACHED */
}
- index->regno = regno;
- s = new_stmt(BPF_ST);
- s->s.k = regno;
- sappend(index->s, s);
- return index;
+ return (b0);
}
struct block *
-gen_relation(code, a0, a1, reversed)
- int code;
- struct arth *a0, *a1;
- int reversed;
+gen_p80211_fcdir(int fcdir)
{
- struct slist *s0, *s1, *s2;
- struct block *b, *tmp;
-
- s0 = xfer_to_x(a1);
- s1 = xfer_to_a(a0);
- s2 = new_stmt(BPF_ALU|BPF_SUB|BPF_X);
- b = new_block(JMP(code));
- if (code == BPF_JGT || code == BPF_JGE) {
- reversed = !reversed;
- b->s.k = 0x80000000;
- }
- if (reversed)
- gen_not(b);
-
- sappend(s1, s2);
- sappend(s0, s1);
- sappend(a1->s, s0);
- sappend(a0->s, a1->s);
+ struct block *b0;
- b->stmts = a0->s;
+ switch (linktype) {
- free_reg(a0->regno);
- free_reg(a1->regno);
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ break;
- /* 'and' together protocol checks */
- if (a0->b) {
- if (a1->b) {
- gen_and(a0->b, tmp = a1->b);
- }
- else
- tmp = a0->b;
- } else
- tmp = a1->b;
+ default:
+ bpf_error("frame direction supported only with 802.11 headers");
+ /* NOTREACHED */
+ }
- if (tmp)
- gen_and(tmp, b);
+ b0 = gen_mcmp(OR_LINK, 1, BPF_B, (bpf_int32)fcdir,
+ (bpf_u_int32)IEEE80211_FC1_DIR_MASK);
- return b;
+ return (b0);
}
-struct arth *
-gen_loadlen()
+struct block *
+gen_acode(eaddr, q)
+ register const u_char *eaddr;
+ struct qual q;
{
- int regno = alloc_reg();
- struct arth *a = (struct arth *)newchunk(sizeof(*a));
- struct slist *s;
+ switch (linktype) {
- s = new_stmt(BPF_LD|BPF_LEN);
- s->next = new_stmt(BPF_ST);
- s->next->s.k = regno;
- a->s = s;
- a->regno = regno;
+ case DLT_ARCNET:
+ case DLT_ARCNET_LINUX:
+ if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) &&
+ q.proto == Q_LINK)
+ return (gen_ahostop(eaddr, (int)q.dir));
+ else {
+ bpf_error("ARCnet address used in non-arc expression");
+ /* NOTREACHED */
+ }
+ break;
- return a;
+ default:
+ bpf_error("aid supported only on ARCnet");
+ /* NOTREACHED */
+ }
+ bpf_error("ARCnet address used in non-arc expression");
+ /* NOTREACHED */
+ return NULL;
}
-struct arth *
-gen_loadi(val)
- int val;
+static struct block *
+gen_ahostop(eaddr, dir)
+ register const u_char *eaddr;
+ register int dir;
{
- struct arth *a;
- struct slist *s;
- int reg;
+ register struct block *b0, *b1;
- a = (struct arth *)newchunk(sizeof(*a));
+ switch (dir) {
+ /* src comes first, different from Ethernet */
+ case Q_SRC:
+ return gen_bcmp(OR_LINK, 0, 1, eaddr);
- reg = alloc_reg();
+ case Q_DST:
+ return gen_bcmp(OR_LINK, 1, 1, eaddr);
- s = new_stmt(BPF_LD|BPF_IMM);
- s->s.k = val;
- s->next = new_stmt(BPF_ST);
- s->next->s.k = reg;
- a->s = s;
- a->regno = reg;
+ case Q_AND:
+ b0 = gen_ahostop(eaddr, Q_SRC);
+ b1 = gen_ahostop(eaddr, Q_DST);
+ gen_and(b0, b1);
+ return b1;
- return a;
+ case Q_DEFAULT:
+ case Q_OR:
+ b0 = gen_ahostop(eaddr, Q_SRC);
+ b1 = gen_ahostop(eaddr, Q_DST);
+ gen_or(b0, b1);
+ return b1;
+ }
+ abort();
+ /* NOTREACHED */
}
-struct arth *
-gen_neg(a)
- struct arth *a;
+/*
+ * support IEEE 802.1Q VLAN trunk over ethernet
+ */
+struct block *
+gen_vlan(vlan_num)
+ int vlan_num;
{
- struct slist *s;
-
- s = xfer_to_a(a);
- sappend(a->s, s);
- s = new_stmt(BPF_ALU|BPF_NEG);
- s->s.k = 0;
- sappend(a->s, s);
- s = new_stmt(BPF_ST);
- s->s.k = a->regno;
- sappend(a->s, s);
+ struct block *b0, *b1;
- return a;
-}
+ /* can't check for VLAN-encapsulated packets inside MPLS */
+ if (label_stack_depth > 0)
+ bpf_error("no VLAN match after MPLS");
-struct arth *
-gen_arth(code, a0, a1)
- int code;
- struct arth *a0, *a1;
-{
- struct slist *s0, *s1, *s2;
+ /*
+ * Check for a VLAN packet, and then change the offsets to point
+ * to the type and data fields within the VLAN packet. Just
+ * increment the offsets, so that we can support a hierarchy, e.g.
+ * "vlan 300 && vlan 200" to capture VLAN 200 encapsulated within
+ * VLAN 100.
+ *
+ * XXX - this is a bit of a kludge. If we were to split the
+ * compiler into a parser that parses an expression and
+ * generates an expression tree, and a code generator that
+ * takes an expression tree (which could come from our
+ * parser or from some other parser) and generates BPF code,
+ * we could perhaps make the offsets parameters of routines
+ * and, in the handler for an "AND" node, pass to subnodes
+ * other than the VLAN node the adjusted offsets.
+ *
+ * This would mean that "vlan" would, instead of changing the
+ * behavior of *all* tests after it, change only the behavior
+ * of tests ANDed with it. That would change the documented
+ * semantics of "vlan", which might break some expressions.
+ * However, it would mean that "(vlan and ip) or ip" would check
+ * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
+ * checking only for VLAN-encapsulated IP, so that could still
+ * be considered worth doing; it wouldn't break expressions
+ * that are of the form "vlan and ..." or "vlan N and ...",
+ * which I suspect are the most common expressions involving
+ * "vlan". "vlan or ..." doesn't necessarily do what the user
+ * would really want, now, as all the "or ..." tests would
+ * be done assuming a VLAN, even though the "or" could be viewed
+ * as meaning "or, if this isn't a VLAN packet...".
+ */
+ orig_nl = off_nl;
- s0 = xfer_to_x(a1);
- s1 = xfer_to_a(a0);
- s2 = new_stmt(BPF_ALU|BPF_X|code);
+ switch (linktype) {
- sappend(s1, s2);
- sappend(s0, s1);
- sappend(a1->s, s0);
- sappend(a0->s, a1->s);
+ case DLT_EN10MB:
+ /* check for VLAN */
+ b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
+ (bpf_int32)ETHERTYPE_8021Q);
+
+ /* If a specific VLAN is requested, check VLAN id */
+ if (vlan_num >= 0) {
+ b1 = gen_mcmp(OR_MACPL, 0, BPF_H,
+ (bpf_int32)vlan_num, 0x0fff);
+ gen_and(b0, b1);
+ b0 = b1;
+ }
- free_reg(a1->regno);
+ off_macpl += 4;
+ off_linktype += 4;
+#if 0
+ off_nl_nosnap += 4;
+ off_nl += 4;
+#endif
+ break;
- s0 = new_stmt(BPF_ST);
- a0->regno = s0->s.k = alloc_reg();
- sappend(a0->s, s0);
+ default:
+ bpf_error("no VLAN support for data link type %d",
+ linktype);
+ /*NOTREACHED*/
+ }
- return a0;
+ return (b0);
}
/*
- * Here we handle simple allocation of the scratch registers.
- * If too many registers are alloc'd, the allocator punts.
- */
-static int regused[BPF_MEMWORDS];
-static int curreg;
-
-/*
- * Return the next free register.
+ * support for MPLS
*/
-static int
-alloc_reg()
+struct block *
+gen_mpls(label_num)
+ int label_num;
{
- int n = BPF_MEMWORDS;
+ struct block *b0,*b1;
- while (--n >= 0) {
- if (regused[curreg])
- curreg = (curreg + 1) % BPF_MEMWORDS;
- else {
- regused[curreg] = 1;
- return curreg;
- }
+ /*
+ * Change the offsets to point to the type and data fields within
+ * the MPLS packet. Just increment the offsets, so that we
+ * can support a hierarchy, e.g. "mpls 100000 && mpls 1024" to
+ * capture packets with an outer label of 100000 and an inner
+ * label of 1024.
+ *
+ * XXX - this is a bit of a kludge. See comments in gen_vlan().
+ */
+ orig_nl = off_nl;
+
+ if (label_stack_depth > 0) {
+ /* just match the bottom-of-stack bit clear */
+ b0 = gen_mcmp(OR_MACPL, orig_nl-2, BPF_B, 0, 0x01);
+ } else {
+ /*
+ * Indicate that we're checking MPLS-encapsulated headers,
+ * to make sure higher level code generators don't try to
+ * match against IP-related protocols such as Q_ARP, Q_RARP
+ * etc.
+ */
+ switch (linktype) {
+
+ case DLT_C_HDLC: /* fall through */
+ case DLT_EN10MB:
+ b0 = gen_linktype(ETHERTYPE_MPLS);
+ break;
+
+ case DLT_PPP:
+ b0 = gen_linktype(PPP_MPLS_UCAST);
+ break;
+
+ /* FIXME add other DLT_s ...
+ * for Frame-Relay/and ATM this may get messy due to SNAP headers
+ * leave it for now */
+
+ default:
+ bpf_error("no MPLS support for data link type %d",
+ linktype);
+ b0 = NULL;
+ /*NOTREACHED*/
+ break;
+ }
+ }
+
+ /* If a specific MPLS label is requested, check it */
+ if (label_num >= 0) {
+ label_num = label_num << 12; /* label is shifted 12 bits on the wire */
+ b1 = gen_mcmp(OR_MACPL, orig_nl, BPF_W, (bpf_int32)label_num,
+ 0xfffff000); /* only compare the first 20 bits */
+ gen_and(b0, b1);
+ b0 = b1;
}
- bpf_error("too many registers needed to evaluate expression");
- /* NOTREACHED */
+
+ off_nl_nosnap += 4;
+ off_nl += 4;
+ label_stack_depth++;
+ return (b0);
}
/*
- * Return a register to the table so it can
- * be used later.
+ * Support PPPOE discovery and session.
*/
-static void
-free_reg(n)
- int n;
+struct block *
+gen_pppoed()
{
- regused[n] = 0;
+ /* check for PPPoE discovery */
+ return gen_linktype((bpf_int32)ETHERTYPE_PPPOED);
}
-static struct block *
-gen_len(jmp, n)
- int jmp, n;
+struct block *
+gen_pppoes()
{
- struct slist *s;
- struct block *b;
+ struct block *b0;
- s = new_stmt(BPF_LD|BPF_LEN);
- b = new_block(JMP(jmp));
- b->stmts = s;
- b->s.k = n;
+ /*
+ * Test against the PPPoE session link-layer type.
+ */
+ b0 = gen_linktype((bpf_int32)ETHERTYPE_PPPOES);
- return b;
-}
+ /*
+ * Change the offsets to point to the type and data fields within
+ * the PPP packet, and note that this is PPPoE rather than
+ * raw PPP.
+ *
+ * XXX - this is a bit of a kludge. If we were to split the
+ * compiler into a parser that parses an expression and
+ * generates an expression tree, and a code generator that
+ * takes an expression tree (which could come from our
+ * parser or from some other parser) and generates BPF code,
+ * we could perhaps make the offsets parameters of routines
+ * and, in the handler for an "AND" node, pass to subnodes
+ * other than the PPPoE node the adjusted offsets.
+ *
+ * This would mean that "pppoes" would, instead of changing the
+ * behavior of *all* tests after it, change only the behavior
+ * of tests ANDed with it. That would change the documented
+ * semantics of "pppoes", which might break some expressions.
+ * However, it would mean that "(pppoes and ip) or ip" would check
+ * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than
+ * checking only for VLAN-encapsulated IP, so that could still
+ * be considered worth doing; it wouldn't break expressions
+ * that are of the form "pppoes and ..." which I suspect are the
+ * most common expressions involving "pppoes". "pppoes or ..."
+ * doesn't necessarily do what the user would really want, now,
+ * as all the "or ..." tests would be done assuming PPPoE, even
+ * though the "or" could be viewed as meaning "or, if this isn't
+ * a PPPoE packet...".
+ */
+ orig_linktype = off_linktype; /* save original values */
+ orig_nl = off_nl;
+ is_pppoes = 1;
-struct block *
-gen_greater(n)
- int n;
-{
- return gen_len(BPF_JGE, n);
+ /*
+ * The "network-layer" protocol is PPPoE, which has a 6-byte
+ * PPPoE header, followed by a PPP packet.
+ *
+ * There is no HDLC encapsulation for the PPP packet (it's
+ * encapsulated in PPPoES instead), so the link-layer type
+ * starts at the first byte of the PPP packet. For PPPoE,
+ * that offset is relative to the beginning of the total
+ * link-layer payload, including any 802.2 LLC header, so
+ * it's 6 bytes past off_nl.
+ */
+ off_linktype = off_nl + 6;
+
+ /*
+ * The network-layer offsets are relative to the beginning
+ * of the MAC-layer payload; that's past the 6-byte
+ * PPPoE header and the 2-byte PPP header.
+ */
+ off_nl = 6+2;
+ off_nl_nosnap = 6+2;
+
+ return b0;
}
struct block *
-gen_less(n)
- int n;
+gen_atmfield_code(atmfield, jvalue, jtype, reverse)
+ int atmfield;
+ bpf_int32 jvalue;
+ bpf_u_int32 jtype;
+ int reverse;
{
- struct block *b;
+ struct block *b0;
- b = gen_len(BPF_JGT, n);
- gen_not(b);
+ switch (atmfield) {
- return b;
+ case A_VPI:
+ if (!is_atm)
+ bpf_error("'vpi' supported only on raw ATM");
+ if (off_vpi == (u_int)-1)
+ abort();
+ b0 = gen_ncmp(OR_LINK, off_vpi, BPF_B, 0xffffffff, jtype,
+ reverse, jvalue);
+ break;
+
+ case A_VCI:
+ if (!is_atm)
+ bpf_error("'vci' supported only on raw ATM");
+ if (off_vci == (u_int)-1)
+ abort();
+ b0 = gen_ncmp(OR_LINK, off_vci, BPF_H, 0xffffffff, jtype,
+ reverse, jvalue);
+ break;
+
+ case A_PROTOTYPE:
+ if (off_proto == (u_int)-1)
+ abort(); /* XXX - this isn't on FreeBSD */
+ b0 = gen_ncmp(OR_LINK, off_proto, BPF_B, 0x0f, jtype,
+ reverse, jvalue);
+ break;
+
+ case A_MSGTYPE:
+ if (off_payload == (u_int)-1)
+ abort();
+ b0 = gen_ncmp(OR_LINK, off_payload + MSG_TYPE_POS, BPF_B,
+ 0xffffffff, jtype, reverse, jvalue);
+ break;
+
+ case A_CALLREFTYPE:
+ if (!is_atm)
+ bpf_error("'callref' supported only on raw ATM");
+ if (off_proto == (u_int)-1)
+ abort();
+ b0 = gen_ncmp(OR_LINK, off_proto, BPF_B, 0xffffffff,
+ jtype, reverse, jvalue);
+ break;
+
+ default:
+ abort();
+ }
+ return b0;
}
struct block *
-gen_byteop(op, idx, val)
- int op, idx, val;
+gen_atmtype_abbrev(type)
+ int type;
{
- struct block *b;
- struct slist *s;
+ struct block *b0, *b1;
+
+ switch (type) {
+
+ case A_METAC:
+ /* Get all packets in Meta signalling Circuit */
+ if (!is_atm)
+ bpf_error("'metac' supported only on raw ATM");
+ b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
+ b1 = gen_atmfield_code(A_VCI, 1, BPF_JEQ, 0);
+ gen_and(b0, b1);
+ break;
+
+ case A_BCC:
+ /* Get all packets in Broadcast Circuit*/
+ if (!is_atm)
+ bpf_error("'bcc' supported only on raw ATM");
+ b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
+ b1 = gen_atmfield_code(A_VCI, 2, BPF_JEQ, 0);
+ gen_and(b0, b1);
+ break;
+
+ case A_OAMF4SC:
+ /* Get all cells in Segment OAM F4 circuit*/
+ if (!is_atm)
+ bpf_error("'oam4sc' supported only on raw ATM");
+ b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
+ b1 = gen_atmfield_code(A_VCI, 3, BPF_JEQ, 0);
+ gen_and(b0, b1);
+ break;
+
+ case A_OAMF4EC:
+ /* Get all cells in End-to-End OAM F4 Circuit*/
+ if (!is_atm)
+ bpf_error("'oam4ec' supported only on raw ATM");
+ b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
+ b1 = gen_atmfield_code(A_VCI, 4, BPF_JEQ, 0);
+ gen_and(b0, b1);
+ break;
+
+ case A_SC:
+ /* Get all packets in connection Signalling Circuit */
+ if (!is_atm)
+ bpf_error("'sc' supported only on raw ATM");
+ b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
+ b1 = gen_atmfield_code(A_VCI, 5, BPF_JEQ, 0);
+ gen_and(b0, b1);
+ break;
+
+ case A_ILMIC:
+ /* Get all packets in ILMI Circuit */
+ if (!is_atm)
+ bpf_error("'ilmic' supported only on raw ATM");
+ b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
+ b1 = gen_atmfield_code(A_VCI, 16, BPF_JEQ, 0);
+ gen_and(b0, b1);
+ break;
+
+ case A_LANE:
+ /* Get all LANE packets */
+ if (!is_atm)
+ bpf_error("'lane' supported only on raw ATM");
+ b1 = gen_atmfield_code(A_PROTOTYPE, PT_LANE, BPF_JEQ, 0);
+
+ /*
+ * Arrange that all subsequent tests assume LANE
+ * rather than LLC-encapsulated packets, and set
+ * the offsets appropriately for LANE-encapsulated
+ * Ethernet.
+ *
+ * "off_mac" is the offset of the Ethernet header,
+ * which is 2 bytes past the ATM pseudo-header
+ * (skipping the pseudo-header and 2-byte LE Client
+ * field). The other offsets are Ethernet offsets
+ * relative to "off_mac".
+ */
+ is_lane = 1;
+ off_mac = off_payload + 2; /* MAC header */
+ off_linktype = off_mac + 12;
+ off_macpl = off_mac + 14; /* Ethernet */
+ off_nl = 0; /* Ethernet II */
+ off_nl_nosnap = 3; /* 802.3+802.2 */
+ break;
+
+ case A_LLC:
+ /* Get all LLC-encapsulated packets */
+ if (!is_atm)
+ bpf_error("'llc' supported only on raw ATM");
+ b1 = gen_atmfield_code(A_PROTOTYPE, PT_LLC, BPF_JEQ, 0);
+ is_lane = 0;
+ break;
- switch (op) {
default:
abort();
+ }
+ return b1;
+}
- case '=':
- return gen_cmp((u_int)idx, BPF_B, (bpf_int32)val);
+/*
+ * Filtering for MTP2 messages based on li value
+ * FISU, length is null
+ * LSSU, length is 1 or 2
+ * MSU, length is 3 or more
+ */
+struct block *
+gen_mtp2type_abbrev(type)
+ int type;
+{
+ struct block *b0, *b1;
- case '<':
- b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val);
- b->s.code = JMP(BPF_JGE);
- gen_not(b);
- return b;
+ switch (type) {
- case '>':
- b = gen_cmp((u_int)idx, BPF_B, (bpf_int32)val);
- b->s.code = JMP(BPF_JGT);
- return b;
+ case M_FISU:
+ if ( (linktype != DLT_MTP2) &&
+ (linktype != DLT_ERF) &&
+ (linktype != DLT_MTP2_WITH_PHDR) )
+ bpf_error("'fisu' supported only on MTP2");
+ /* gen_ncmp(offrel, offset, size, mask, jtype, reverse, value) */
+ b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JEQ, 0, 0);
+ break;
- case '|':
- s = new_stmt(BPF_ALU|BPF_OR|BPF_K);
+ case M_LSSU:
+ if ( (linktype != DLT_MTP2) &&
+ (linktype != DLT_ERF) &&
+ (linktype != DLT_MTP2_WITH_PHDR) )
+ bpf_error("'lssu' supported only on MTP2");
+ b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 1, 2);
+ b1 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 0, 0);
+ gen_and(b1, b0);
break;
- case '&':
- s = new_stmt(BPF_ALU|BPF_AND|BPF_K);
+ case M_MSU:
+ if ( (linktype != DLT_MTP2) &&
+ (linktype != DLT_ERF) &&
+ (linktype != DLT_MTP2_WITH_PHDR) )
+ bpf_error("'msu' supported only on MTP2");
+ b0 = gen_ncmp(OR_PACKET, off_li, BPF_B, 0x3f, BPF_JGT, 0, 2);
break;
- }
- s->s.k = val;
- b = new_block(JMP(BPF_JEQ));
- b->stmts = s;
- gen_not(b);
- return b;
+ default:
+ abort();
+ }
+ return b0;
}
struct block *
-gen_broadcast(proto)
- int proto;
+gen_mtp3field_code(mtp3field, jvalue, jtype, reverse)
+ int mtp3field;
+ bpf_u_int32 jvalue;
+ bpf_u_int32 jtype;
+ int reverse;
{
- bpf_u_int32 hostmask;
- struct block *b0, *b1, *b2;
- static u_char ebroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+ struct block *b0;
+ bpf_u_int32 val1 , val2 , val3;
+
+ switch (mtp3field) {
+
+ case M_SIO:
+ if (off_sio == (u_int)-1)
+ bpf_error("'sio' supported only on SS7");
+ /* sio coded on 1 byte so max value 255 */
+ if(jvalue > 255)
+ bpf_error("sio value %u too big; max value = 255",
+ jvalue);
+ b0 = gen_ncmp(OR_PACKET, off_sio, BPF_B, 0xffffffff,
+ (u_int)jtype, reverse, (u_int)jvalue);
+ break;
- switch (proto) {
+ case M_OPC:
+ if (off_opc == (u_int)-1)
+ bpf_error("'opc' supported only on SS7");
+ /* opc coded on 14 bits so max value 16383 */
+ if (jvalue > 16383)
+ bpf_error("opc value %u too big; max value = 16383",
+ jvalue);
+ /* the following instructions are made to convert jvalue
+ * to the form used to write opc in an ss7 message*/
+ val1 = jvalue & 0x00003c00;
+ val1 = val1 >>10;
+ val2 = jvalue & 0x000003fc;
+ val2 = val2 <<6;
+ val3 = jvalue & 0x00000003;
+ val3 = val3 <<22;
+ jvalue = val1 + val2 + val3;
+ b0 = gen_ncmp(OR_PACKET, off_opc, BPF_W, 0x00c0ff0f,
+ (u_int)jtype, reverse, (u_int)jvalue);
+ break;
- case Q_DEFAULT:
- case Q_LINK:
- if (linktype == DLT_EN10MB)
- return gen_ehostop(ebroadcast, Q_DST);
- if (linktype == DLT_FDDI)
- return gen_fhostop(ebroadcast, Q_DST);
- bpf_error("not a broadcast link");
+ case M_DPC:
+ if (off_dpc == (u_int)-1)
+ bpf_error("'dpc' supported only on SS7");
+ /* dpc coded on 14 bits so max value 16383 */
+ if (jvalue > 16383)
+ bpf_error("dpc value %u too big; max value = 16383",
+ jvalue);
+ /* the following instructions are made to convert jvalue
+ * to the forme used to write dpc in an ss7 message*/
+ val1 = jvalue & 0x000000ff;
+ val1 = val1 << 24;
+ val2 = jvalue & 0x00003f00;
+ val2 = val2 << 8;
+ jvalue = val1 + val2;
+ b0 = gen_ncmp(OR_PACKET, off_dpc, BPF_W, 0xff3f0000,
+ (u_int)jtype, reverse, (u_int)jvalue);
break;
- case Q_IP:
- b0 = gen_linktype(ETHERTYPE_IP);
- hostmask = ~netmask;
- b1 = gen_mcmp(off_nl + 16, BPF_W, (bpf_int32)0, hostmask);
- b2 = gen_mcmp(off_nl + 16, BPF_W,
- (bpf_int32)(~0 & hostmask), hostmask);
- gen_or(b1, b2);
- gen_and(b0, b2);
- return b2;
+ case M_SLS:
+ if (off_sls == (u_int)-1)
+ bpf_error("'sls' supported only on SS7");
+ /* sls coded on 4 bits so max value 15 */
+ if (jvalue > 15)
+ bpf_error("sls value %u too big; max value = 15",
+ jvalue);
+ /* the following instruction is made to convert jvalue
+ * to the forme used to write sls in an ss7 message*/
+ jvalue = jvalue << 4;
+ b0 = gen_ncmp(OR_PACKET, off_sls, BPF_B, 0xf0,
+ (u_int)jtype,reverse, (u_int)jvalue);
+ break;
+
+ default:
+ abort();
}
- bpf_error("only ether/ip broadcast filters supported");
+ return b0;
}
-struct block *
-gen_multicast(proto)
- int proto;
+static struct block *
+gen_msg_abbrev(type)
+ int type;
{
- register struct block *b0, *b1;
- register struct slist *s;
+ struct block *b1;
- switch (proto) {
+ /*
+ * Q.2931 signalling protocol messages for handling virtual circuits
+ * establishment and teardown
+ */
+ switch (type) {
- case Q_DEFAULT:
- case Q_LINK:
- if (linktype == DLT_EN10MB) {
- /* ether[0] & 1 != 0 */
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
- b0 = new_block(JMP(BPF_JSET));
- b0->s.k = 1;
- b0->stmts = s;
- return b0;
- }
+ case A_SETUP:
+ b1 = gen_atmfield_code(A_MSGTYPE, SETUP, BPF_JEQ, 0);
+ break;
- if (linktype == DLT_FDDI) {
- /* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX */
- /* fddi[1] & 1 != 0 */
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
- b0 = new_block(JMP(BPF_JSET));
- b0->s.k = 1;
- b0->stmts = s;
- return b0;
- }
- /* Link not known to support multicasts */
+ case A_CALLPROCEED:
+ b1 = gen_atmfield_code(A_MSGTYPE, CALL_PROCEED, BPF_JEQ, 0);
break;
- case Q_IP:
- b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp(off_nl + 16, BPF_B, (bpf_int32)224);
- b1->s.code = JMP(BPF_JGE);
- gen_and(b0, b1);
- return b1;
+ case A_CONNECT:
+ b1 = gen_atmfield_code(A_MSGTYPE, CONNECT, BPF_JEQ, 0);
+ break;
+
+ case A_CONNECTACK:
+ b1 = gen_atmfield_code(A_MSGTYPE, CONNECT_ACK, BPF_JEQ, 0);
+ break;
+
+ case A_RELEASE:
+ b1 = gen_atmfield_code(A_MSGTYPE, RELEASE, BPF_JEQ, 0);
+ break;
+
+ case A_RELEASE_DONE:
+ b1 = gen_atmfield_code(A_MSGTYPE, RELEASE_DONE, BPF_JEQ, 0);
+ break;
+
+ default:
+ abort();
}
- bpf_error("only IP multicast filters supported on ethernet/FDDI");
+ return b1;
}
-/*
- * generate command for inbound/outbound. It's here so we can
- * make it link-type specific. 'dir' = 0 implies "inbound",
- * = 1 implies "outbound".
- */
struct block *
-gen_inbound(dir)
- int dir;
+gen_atmmulti_abbrev(type)
+ int type;
{
- register struct block *b0;
+ struct block *b0, *b1;
- b0 = gen_relation(BPF_JEQ,
- gen_load(Q_LINK, gen_loadi(0), 1),
- gen_loadi(0),
- dir);
- return (b0);
+ switch (type) {
+
+ case A_OAM:
+ if (!is_atm)
+ bpf_error("'oam' supported only on raw ATM");
+ b1 = gen_atmmulti_abbrev(A_OAMF4);
+ break;
+
+ case A_OAMF4:
+ if (!is_atm)
+ bpf_error("'oamf4' supported only on raw ATM");
+ /* OAM F4 type */
+ b0 = gen_atmfield_code(A_VCI, 3, BPF_JEQ, 0);
+ b1 = gen_atmfield_code(A_VCI, 4, BPF_JEQ, 0);
+ gen_or(b0, b1);
+ b0 = gen_atmfield_code(A_VPI, 0, BPF_JEQ, 0);
+ gen_and(b0, b1);
+ break;
+
+ case A_CONNECTMSG:
+ /*
+ * Get Q.2931 signalling messages for switched
+ * virtual connection
+ */
+ if (!is_atm)
+ bpf_error("'connectmsg' supported only on raw ATM");
+ b0 = gen_msg_abbrev(A_SETUP);
+ b1 = gen_msg_abbrev(A_CALLPROCEED);
+ gen_or(b0, b1);
+ b0 = gen_msg_abbrev(A_CONNECT);
+ gen_or(b0, b1);
+ b0 = gen_msg_abbrev(A_CONNECTACK);
+ gen_or(b0, b1);
+ b0 = gen_msg_abbrev(A_RELEASE);
+ gen_or(b0, b1);
+ b0 = gen_msg_abbrev(A_RELEASE_DONE);
+ gen_or(b0, b1);
+ b0 = gen_atmtype_abbrev(A_SC);
+ gen_and(b0, b1);
+ break;
+
+ case A_METACONNECT:
+ if (!is_atm)
+ bpf_error("'metaconnect' supported only on raw ATM");
+ b0 = gen_msg_abbrev(A_SETUP);
+ b1 = gen_msg_abbrev(A_CALLPROCEED);
+ gen_or(b0, b1);
+ b0 = gen_msg_abbrev(A_CONNECT);
+ gen_or(b0, b1);
+ b0 = gen_msg_abbrev(A_RELEASE);
+ gen_or(b0, b1);
+ b0 = gen_msg_abbrev(A_RELEASE_DONE);
+ gen_or(b0, b1);
+ b0 = gen_atmtype_abbrev(A_METAC);
+ gen_and(b0, b1);
+ break;
+
+ default:
+ abort();
+ }
+ return b1;
}
projects / libpcap / blobdiff