* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
-#ifndef lint
-static const char rcsid[] _U_ =
- "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.240 2005-05-01 09:17:45 guy Exp $ (LBL)";
-#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#ifdef WIN32
#include <pcap-stdinc.h>
#else /* WIN32 */
+#if HAVE_INTTYPES_H
+#include <inttypes.h>
+#elif HAVE_STDINT_H
+#include <stdint.h>
+#endif
+#ifdef HAVE_SYS_BITYPES_H
+#include <sys/bitypes.h>
+#endif
#include <sys/types.h>
#include <sys/socket.h>
#endif /* WIN32 */
* XXX - why was this included even on UNIX?
*/
#ifdef __MINGW32__
-#include "IP6_misc.h"
+#include "ip6_misc.h"
#endif
#ifndef WIN32
#endif
#include <netinet/in.h>
+#include <arpa/inet.h>
#endif /* WIN32 */
#include "nlpid.h"
#include "llc.h"
#include "gencode.h"
+#include "ieee80211.h"
#include "atmuni31.h"
#include "sunatmpos.h"
#include "ppp.h"
-#include "sll.h"
+#include "pcap/sll.h"
+#include "pcap/ipnet.h"
#include "arcnet.h"
-#include "pf.h"
+#if defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER)
+#include <linux/types.h>
+#include <linux/if_packet.h>
+#include <linux/filter.h>
+#endif
+#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
#include <netdb.h> /* for "struct addrinfo" */
#endif /* WIN32 */
#endif /*INET6*/
-#include <pcap-namedb.h>
+#include <pcap/namedb.h>
#define ETHERMTU 1500
+#ifndef IPPROTO_HOPOPTS
+#define IPPROTO_HOPOPTS 0
+#endif
+#ifndef IPPROTO_ROUTING
+#define IPPROTO_ROUTING 43
+#endif
+#ifndef IPPROTO_FRAGMENT
+#define IPPROTO_FRAGMENT 44
+#endif
+#ifndef IPPROTO_DSTOPTS
+#define IPPROTO_DSTOPTS 60
+#endif
#ifndef IPPROTO_SCTP
#define IPPROTO_SCTP 132
#endif
static jmp_buf top_ctx;
static pcap_t *bpf_pcap;
-/* Hack for updating VLAN, MPLS offsets. */
-static u_int orig_linktype = -1U, orig_nl = -1U;
+/* Hack for handling VLAN and MPLS stacks. */
+#ifdef WIN32
+static u_int label_stack_depth = (u_int)-1, vlan_stack_depth = (u_int)-1;
+#else
+static u_int label_stack_depth = -1U, vlan_stack_depth = -1U;
+#endif
/* XXX */
-#ifdef PCAP_FDDIPAD
static int pcap_fddipad;
-#endif
/* VARARGS */
void
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;
+/*
+ * Absolute offsets, which are offsets from the beginning of the raw
+ * packet data, are, in the general case, the sum of a variable value
+ * and a constant value; the variable value may be absent, in which
+ * case the offset is only the constant value, and the constant value
+ * may be zero, in which case the offset is only the variable value.
+ *
+ * bpf_abs_offset is a structure containing all that information:
+ *
+ * is_variable is 1 if there's a variable part.
+ *
+ * constant_part is the constant part of the value, possibly zero;
+ *
+ * if is_variable is 1, reg is the register number for a register
+ * containing the variable value if the register has been assigned,
+ * and -1 otherwise.
+ */
+typedef struct {
+ int is_variable;
+ u_int constant_part;
+ int reg;
+} bpf_abs_offset;
+
/*
* Value passed to gen_load_a() to indicate what the offset argument
- * is relative to.
+ * is relative to the beginning of.
*/
enum e_offrel {
- OR_LINK, /* relative to the link-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 */
+ OR_PACKET, /* full packet data */
+ OR_LINKHDR, /* link-layer header */
+ OR_PREVLINKHDR, /* previous link-layer header */
+ OR_LLC, /* 802.2 LLC header */
+ OR_PREVMPLSHDR, /* previous MPLS header */
+ OR_LINKTYPE, /* link-layer type */
+ OR_LINKPL, /* link-layer payload */
+ OR_LINKPL_NOSNAP, /* link-layer payload, with no SNAP header at the link layer */
+ OR_TRAN_IPV4, /* transport-layer header, with IPv4 network layer */
+ OR_TRAN_IPV6 /* transport-layer header, with IPv6 network layer */
};
+#ifdef INET6
+/*
+ * As errors are handled by a longjmp, anything allocated must be freed
+ * in the longjmp handler, so it must be reachable from that handler.
+ * One thing that's allocated is the result of pcap_nametoaddrinfo();
+ * it must be freed with freeaddrinfo(). This variable points to any
+ * addrinfo structure that would need to be freed.
+ */
+static struct addrinfo *ai;
+#endif
+
/*
* 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
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_absoffsetrel(bpf_abs_offset *, 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_ipnet_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_abs_offset_varpart(bpf_abs_offset *);
+static int ethertype_to_ppptype(int);
static struct block *gen_linktype(int);
-static struct block *gen_snap(bpf_u_int32, bpf_u_int32, u_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_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_host(bpf_u_int32, bpf_u_int32, int, 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);
+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);
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_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 *
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;
- int len;
+ const char * volatile xbuf = buf;
+ u_int len;
+ int rc;
+
+ /*
+ * XXX - single-thread this code path with pthread calls on
+ * UN*X, if the platform supports pthreads? If that requires
+ * a separate -lpthread, we might not want to do that.
+ */
+#ifdef WIN32
+ extern int wsockinit (void);
+ static int done = 0;
+
+ if (!done)
+ wsockinit();
+ done = 1;
+ EnterCriticalSection(&g_PcapCompileCriticalSection);
+#endif
+ /*
+ * If this pcap_t hasn't been activated, it doesn't have a
+ * link-layer type, so we can't use it.
+ */
+ if (!p->activated) {
+ snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
+ "not-yet-activated pcap_t passed to pcap_compile");
+ rc = -1;
+ goto quit;
+ }
no_optimize = 0;
n_errors = 0;
root = NULL;
bpf_pcap = p;
+ init_regs();
+
if (setjmp(top_ctx)) {
+#ifdef INET6
+ if (ai != NULL) {
+ freeaddrinfo(ai);
+ ai = NULL;
+ }
+#endif
lex_cleanup();
freechunks();
- return (-1);
+ rc = -1;
+ goto quit;
}
netmask = mask;
if (snaplen == 0) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"snaplen of 0 rejects all packets");
- return -1;
+ rc = -1;
+ goto quit;
}
- lex_init(buf ? buf : "");
+ lex_init(xbuf ? xbuf : "");
init_linktype(p);
(void)pcap_parse();
lex_cleanup();
freechunks();
- return (0);
+
+ rc = 0; /* We're all okay */
+
+quit:
+
+#ifdef WIN32
+ LeaveCriticalSection(&g_PcapCompileCriticalSection);
+#endif
+
+ return (rc);
}
/*
int
pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
struct bpf_program *program,
- char *buf, int optimize, bpf_u_int32 mask)
+ const char *buf, int optimize, bpf_u_int32 mask)
{
pcap_t *p;
int ret;
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));
}
/*
- * Various code constructs need to know the layout of the data link
- * layer. These variables give the necessary offsets.
+ * Various code constructs need to know the layout of the packet.
+ * These variables give the necessary offsets from the beginning
+ * of the packet data.
+ */
+
+/*
+ * Absolute offset of the beginning of the link-layer header.
+ */
+static bpf_abs_offset off_linkhdr;
+
+/*
+ * If we're checking a link-layer header for a packet encapsulated in
+ * another protocol layer, this is the equivalent information for the
+ * previous layers' link-layer header from the beginning of the raw
+ * packet data.
+ */
+static bpf_abs_offset off_prevlinkhdr;
+
+/*
+ * This is the equivalent information for the outermost layers' link-layer
+ * header.
+ */
+static bpf_abs_offset off_outermostlinkhdr;
+
+/*
+ * "Push" the current value of the link-layer header type and link-layer
+ * header offset onto a "stack", and set a new value. (It's not a
+ * full-blown stack; we keep only the top two items.)
*/
+#define PUSH_LINKHDR(new_linktype, new_is_variable, new_constant_part, new_reg) \
+{ \
+ prevlinktype = new_linktype; \
+ off_prevlinkhdr = off_linkhdr; \
+ linktype = new_linktype; \
+ off_linkhdr.is_variable = new_is_variable; \
+ off_linkhdr.constant_part = new_constant_part; \
+ off_linkhdr.reg = new_reg; \
+}
/*
- * This is the offset of the beginning of the MAC-layer header.
- * It's usually 0, except for ATM LANE.
+ * Absolute offset of the beginning of the link-layer payload.
*/
-static u_int off_mac;
+static bpf_abs_offset off_linkpl;
/*
* "off_linktype" is the offset to information in the link-layer header
- * giving the packet type.
+ * giving the packet type. This is an absolute offset from the beginning
+ * of the packet.
*
- * For Ethernet, it's the offset of the Ethernet type field.
+ * For Ethernet, it's the offset of the Ethernet type field; this
+ * means that it must have a value that skips VLAN tags.
*
* For link-layer types that always use 802.2 headers, it's the
- * offset of the LLC header.
+ * offset of the LLC header; this means that it must have a value
+ * that skips VLAN tags.
*
* For PPP, it's the offset of the PPP type field.
*
*
* 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.
+ * off_linktype.constant_part is set to -1 for no encapsulation,
+ * in which case, IP is assumed.
*/
-static u_int off_linktype;
+static bpf_abs_offset off_linktype;
/*
* 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_vci;
static u_int off_proto;
+/*
+ * These are offsets for the MTP2 fields.
+ */
+static u_int off_li;
+static u_int off_li_hsl;
+
+/*
+ * 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.
/*
* These are offsets to the beginning of the network-layer header.
+ * They are relative to the beginning of the link-layer payload (i.e.,
+ * they don't include off_linkhdr.constant_part or off_linkpl.constant_part).
*
* If the link layer never uses 802.2 LLC:
*
static u_int off_nl_nosnap;
static int linktype;
+static int prevlinktype;
+static int outermostlinktype;
static void
init_linktype(p)
pcap_t *p;
{
- linktype = pcap_datalink(p);
-#ifdef PCAP_FDDIPAD
pcap_fddipad = p->fddipad;
-#endif
+
+ /*
+ * We start out with only one link-layer header.
+ */
+ outermostlinktype = pcap_datalink(p);
+ off_outermostlinkhdr.constant_part = 0;
+ off_outermostlinkhdr.is_variable = 0;
+ off_outermostlinkhdr.reg = -1;
+
+ prevlinktype = outermostlinktype;
+ off_prevlinkhdr.constant_part = 0;
+ off_prevlinkhdr.is_variable = 0;
+ off_prevlinkhdr.reg = -1;
+
+ linktype = outermostlinktype;
+ off_linkhdr.constant_part = 0;
+ off_linkhdr.is_variable = 0;
+ off_linkhdr.reg = -1;
+
+ /*
+ * XXX
+ */
+ off_linkpl.constant_part = 0;
+ off_linkpl.is_variable = 0;
+ off_linkpl.reg = -1;
+
+ off_linktype.constant_part = 0;
+ off_linktype.is_variable = 0;
+ off_linktype.reg = -1;
/*
* 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;
- orig_linktype = -1;
- orig_nl = -1;
+ /*
+ * And assume we're not doing SS7.
+ */
+ off_li = -1;
+ off_li_hsl = -1;
+ off_sio = -1;
+ off_opc = -1;
+ off_dpc = -1;
+ off_sls = -1;
+
+ label_stack_depth = 0;
+ vlan_stack_depth = 0;
switch (linktype) {
case DLT_ARCNET:
- off_linktype = 2;
- off_nl = 6; /* XXX in reality, variable! */
- off_nl_nosnap = 6; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 2;
+ off_linkpl.constant_part = 6;
+ off_nl = 0; /* XXX in reality, variable! */
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_ARCNET_LINUX:
- off_linktype = 4;
- off_nl = 8; /* XXX in reality, variable! */
- off_nl_nosnap = 8; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 4;
+ off_linkpl.constant_part = 8;
+ off_nl = 0; /* XXX in reality, variable! */
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_EN10MB:
- off_linktype = 12;
- off_nl = 14; /* Ethernet II */
- off_nl_nosnap = 17; /* 802.3+802.2 */
- return;
+ off_linktype.constant_part = 12;
+ off_linkpl.constant_part = 14; /* Ethernet header length */
+ off_nl = 0; /* Ethernet II */
+ off_nl_nosnap = 3; /* 802.3+802.2 */
+ break;
case DLT_SLIP:
/*
* SLIP doesn't have a link level type. The 16 byte
* header is hacked into our SLIP driver.
*/
- off_linktype = -1;
- off_nl = 16;
- off_nl_nosnap = 16; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = 16;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_SLIP_BSDOS:
/* XXX this may be the same as the DLT_PPP_BSDOS case */
- off_linktype = -1;
+ off_linktype.constant_part = -1;
/* XXX end */
- off_nl = 24;
- off_nl_nosnap = 24; /* no 802.2 LLC */
- return;
+ off_linkpl.constant_part = 24;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_NULL:
case DLT_LOOP:
- off_linktype = 0;
- off_nl = 4;
- off_nl_nosnap = 4; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 0;
+ off_linkpl.constant_part = 4;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_ENC:
- off_linktype = 0;
- off_nl = 12;
- off_nl_nosnap = 12; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 0;
+ off_linkpl.constant_part = 12;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
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_nl_nosnap = 4; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 2; /* skip HDLC-like framing */
+ off_linkpl.constant_part = 4; /* skip HDLC-like framing and protocol field */
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_PPP_ETHER:
/*
* This does no include the Ethernet header, and
* only covers session state.
*/
- off_linktype = 6;
- off_nl = 8;
- off_nl_nosnap = 8; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 6;
+ off_linkpl.constant_part = 8;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_PPP_BSDOS:
- off_linktype = 5;
- off_nl = 24;
- off_nl_nosnap = 24; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 5;
+ off_linkpl.constant_part = 24;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_FDDI:
/*
* is being used and pick out the encapsulated Ethernet type.
* XXX - should we generate code to check for SNAP?
*/
- off_linktype = 13;
-#ifdef PCAP_FDDIPAD
- off_linktype += pcap_fddipad;
-#endif
- off_nl = 21; /* FDDI+802.2+SNAP */
- off_nl_nosnap = 16; /* FDDI+802.2 */
-#ifdef PCAP_FDDIPAD
- off_nl += pcap_fddipad;
- off_nl_nosnap += pcap_fddipad;
-#endif
- return;
+ off_linktype.constant_part = 13;
+ off_linktype.constant_part += pcap_fddipad;
+ off_linkpl.constant_part = 13; /* FDDI MAC header length */
+ off_linkpl.constant_part += pcap_fddipad;
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ break;
case DLT_IEEE802:
/*
* the 16-bit value at an offset of 14 (shifted right
* 8 - figure out which byte that is).
*/
- off_linktype = 14;
- off_nl = 22; /* Token Ring+802.2+SNAP */
- off_nl_nosnap = 17; /* Token Ring+802.2 */
- return;
+ off_linktype.constant_part = 14;
+ off_linkpl.constant_part = 14; /* Token Ring MAC header length */
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ break;
+
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ off_linkhdr.is_variable = 1;
+ /* Fall through, 802.11 doesn't have a variable link
+ * prefix but is otherwise the same. */
case DLT_IEEE802_11:
/*
* 802.11 doesn't really have a link-level type field.
- * We set "off_linktype" to the offset of the LLC header.
+ * We set "off_linktype.constant_part" 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. We
- * assume a 24-byte link-layer header, as appears in
- * data frames in networks with no bridges. If the
- * fromds and tods 802.11 header bits are both set,
- * it's actually supposed to be 30 bytes.
- */
- off_linktype = 24;
- off_nl = 32; /* 802.11+802.2+SNAP */
- off_nl_nosnap = 27; /* 802.11+802.2 */
- return;
-
- case DLT_PRISM_HEADER:
- /*
- * Same as 802.11, but with an additional header before
- * the 802.11 header, containing a bunch of additional
- * information including radio-level information.
- *
- * The header is 144 bytes long.
- *
- * XXX - same variable-length header problem; at least
- * the Prism header is fixed-length.
- */
- off_linktype = 144+24;
- off_nl = 144+32; /* Prism+802.11+802.2+SNAP */
- off_nl_nosnap = 144+27; /* Prism+802.11+802.2 */
- return;
-
- case DLT_IEEE802_11_RADIO_AVS:
- /*
- * Same as 802.11, but with an additional header before
- * the 802.11 header, containing a bunch of additional
- * information including radio-level information.
- *
- * The header is 64 bytes long, at least in its
- * current incarnation.
- *
- * XXX - same variable-length header problem, only
- * more so; this header is also variable-length,
- * with the length being the 32-bit big-endian
- * number at an offset of 4 from the beginning
- * of the radio header.
+ * 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 = 64+24;
- off_nl = 64+32; /* Radio+802.11+802.2+SNAP */
- off_nl_nosnap = 64+27; /* Radio+802.11+802.2 */
- return;
+ off_linktype.constant_part = 24;
+ off_linkpl.constant_part = 0; /* link-layer header is variable-length */
+ off_linkpl.is_variable = 1;
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ break;
- case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
/*
- * Same as 802.11, but with an additional header before
- * the 802.11 header, containing a bunch of additional
- * information including radio-level information.
- *
- * XXX - same variable-length header problem, only
- * even *more* so; this header is also variable-length,
- * with the length being the 16-bit number at an offset
- * of 2 from the beginning of the radio header, and it's
- * device-dependent (different devices might supply
- * different amounts of information), so we can't even
- * assume a fixed length for the current version of the
- * header.
- *
- * Therefore, currently, only raw "link[N:M]" filtering is
- * supported.
+ * 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 = -1;
- off_nl = -1;
- off_nl_nosnap = -1;
- return;
+ off_linktype.constant_part = 24;
+ off_linkpl.constant_part = 0; /* link-layer header is variable-length */
+ off_linkpl.is_variable = 1;
+ off_linkhdr.is_variable = 1;
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ break;
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 = 0;
+ off_linktype.constant_part = 0;
+ off_linkpl.constant_part = 0; /* packet begins with LLC header */
off_nl = 8; /* 802.2+SNAP */
off_nl_nosnap = 3; /* 802.2 */
- return;
+ break;
case DLT_SUNATM:
/*
off_vpi = SUNATM_VPI_POS;
off_vci = SUNATM_VCI_POS;
off_proto = PROTO_POS;
- off_mac = -1; /* LLC-encapsulated, so no MAC-layer header */
off_payload = SUNATM_PKT_BEGIN_POS;
- off_linktype = off_payload;
- off_nl = off_payload+8; /* 802.2+SNAP */
- off_nl_nosnap = off_payload+3; /* 802.2 */
- return;
+ off_linktype.constant_part = off_payload;
+ off_linkpl.constant_part = off_payload; /* if LLC-encapsulated */
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ break;
case DLT_RAW:
- off_linktype = -1;
+ case DLT_IPV4:
+ case DLT_IPV6:
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = 0;
off_nl = 0;
off_nl_nosnap = 0; /* no 802.2 LLC */
- return;
+ break;
case DLT_LINUX_SLL: /* fake header for Linux cooked socket */
- off_linktype = 14;
- off_nl = 16;
- off_nl_nosnap = 16; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 14;
+ off_linkpl.constant_part = 16;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_LTALK:
/*
* but really it just indicates whether there is a "short" or
* "long" DDP packet following.
*/
- off_linktype = -1;
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = 0;
off_nl = 0;
off_nl_nosnap = 0; /* no 802.2 LLC */
- return;
+ break;
case DLT_IP_OVER_FC:
/*
* XXX - should we generate code to check for SNAP? RFC
* 2625 says SNAP should be used.
*/
- off_linktype = 16;
- off_nl = 24; /* IPFC+802.2+SNAP */
- off_nl_nosnap = 19; /* IPFC+802.2 */
- return;
+ off_linktype.constant_part = 16;
+ off_linkpl.constant_part = 16;
+ off_nl = 8; /* 802.2+SNAP */
+ off_nl_nosnap = 3; /* 802.2 */
+ break;
case DLT_FRELAY:
/*
* XXX - we should set this to handle SNAP-encapsulated
* frames (NLPID of 0x80).
*/
- off_linktype = -1;
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = 0;
off_nl = 0;
off_nl_nosnap = 0; /* no 802.2 LLC */
- return;
-
- case DLT_APPLE_IP_OVER_IEEE1394:
- off_linktype = 16;
- off_nl = 18;
- off_nl_nosnap = 18; /* no 802.2 LLC */
- return;
+ break;
- case DLT_LINUX_IRDA:
- /*
- * Currently, only raw "link[N:M]" filtering is supported.
- */
- off_linktype = -1;
- off_nl = -1;
- off_nl_nosnap = -1;
- 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.constant_part = -1;
+ off_linkpl.constant_part = 0;
+ off_nl = 4;
+ off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */
+ break;
- case DLT_DOCSIS:
- /*
- * Currently, only raw "link[N:M]" filtering is supported.
- */
- off_linktype = -1;
- off_nl = -1;
- off_nl_nosnap = -1;
- return;
+ case DLT_APPLE_IP_OVER_IEEE1394:
+ off_linktype.constant_part = 16;
+ off_linkpl.constant_part = 18;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
case DLT_SYMANTEC_FIREWALL:
- off_linktype = 6;
- off_nl = 44; /* Ethernet II */
- off_nl_nosnap = 44; /* XXX - what does it do with 802.3 packets? */
- return;
+ off_linktype.constant_part = 6;
+ off_linkpl.constant_part = 44;
+ off_nl = 0; /* Ethernet II */
+ off_nl_nosnap = 0; /* XXX - what does it do with 802.3 packets? */
+ break;
+#ifdef HAVE_NET_PFVAR_H
case DLT_PFLOG:
- off_linktype = 0;
- /* XXX read this from pf.h? */
- off_nl = PFLOG_HDRLEN;
- off_nl_nosnap = PFLOG_HDRLEN; /* no 802.2 LLC */
- return;
+ off_linktype.constant_part = 0;
+ off_linkpl.constant_part = PFLOG_HDRLEN;
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+ break;
+#endif
+ case DLT_JUNIPER_MFR:
case DLT_JUNIPER_MLFR:
case DLT_JUNIPER_MLPPP:
- off_linktype = 4;
- off_nl = 4;
+ case DLT_JUNIPER_PPP:
+ case DLT_JUNIPER_CHDLC:
+ case DLT_JUNIPER_FRELAY:
+ off_linktype.constant_part = 4;
+ off_linkpl.constant_part = 4;
+ off_nl = 0;
off_nl_nosnap = -1; /* no 802.2 LLC */
- return;
+ break;
case DLT_JUNIPER_ATM1:
- off_linktype = 4; /* in reality variable between 4-8 */
- off_nl = 4;
- off_nl_nosnap = 14;
- return;
+ off_linktype.constant_part = 4; /* in reality variable between 4-8 */
+ off_linkpl.constant_part = 4; /* in reality variable between 4-8 */
+ off_nl = 0;
+ off_nl_nosnap = 10;
+ break;
case DLT_JUNIPER_ATM2:
- off_linktype = 8; /* in reality variable between 8-12 */
- off_nl = 8;
- off_nl_nosnap = 18;
- return;
-
-#ifdef DLT_PFSYNC
- case DLT_PFSYNC:
- off_linktype = -1;
- off_nl = 4;
- off_nl_nosnap = 4;
- return;
-#endif
-
- case DLT_LINUX_LAPD:
- /*
- * Currently, only raw "link[N:M]" filtering is supported.
- */
- off_linktype = -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 specified header.
- */
-static struct slist *
-gen_load_a(offrel, offset, size)
- enum e_offrel offrel;
- u_int offset, size;
-{
- struct slist *s, *s2;
+ off_linktype.constant_part = 8; /* in reality variable between 8-12 */
+ off_linkpl.constant_part = 8; /* in reality variable between 8-12 */
+ off_nl = 0;
+ off_nl_nosnap = 10;
+ break;
- switch (offrel) {
+ /* frames captured on a Juniper PPPoE service PIC
+ * contain raw ethernet frames */
+ case DLT_JUNIPER_PPPOE:
+ case DLT_JUNIPER_ETHER:
+ off_linkpl.constant_part = 14;
+ off_linktype.constant_part = 16;
+ off_nl = 18; /* Ethernet II */
+ off_nl_nosnap = 21; /* 802.3+802.2 */
+ break;
- case OR_LINK:
- s = new_stmt(BPF_LD|BPF_ABS|size);
- s->s.k = offset;
+ case DLT_JUNIPER_PPPOE_ATM:
+ off_linktype.constant_part = 4;
+ off_linkpl.constant_part = 6;
+ off_nl = 0;
+ off_nl_nosnap = -1; /* no 802.2 LLC */
break;
- case OR_NET:
- s = new_stmt(BPF_LD|BPF_ABS|size);
- s->s.k = off_nl + offset;
+ case DLT_JUNIPER_GGSN:
+ off_linktype.constant_part = 6;
+ off_linkpl.constant_part = 12;
+ off_nl = 0;
+ off_nl_nosnap = -1; /* no 802.2 LLC */
break;
- case OR_NET_NOSNAP:
- s = new_stmt(BPF_LD|BPF_ABS|size);
- s->s.k = off_nl_nosnap + offset;
+ case DLT_JUNIPER_ES:
+ off_linktype.constant_part = 6;
+ off_linkpl.constant_part = -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 */
break;
- case OR_TRAN_IPV4:
- /*
- * Load the X register with the length of the IPv4 header,
- * in bytes.
- */
- s = gen_loadx_iphdrlen();
+ case DLT_JUNIPER_MONITOR:
+ off_linktype.constant_part = 12;
+ off_linkpl.constant_part = 12;
+ off_nl = 0; /* raw IP/IP6 header */
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ break;
- /*
- * Load the item at {length of the link-layer header} +
- * {length of the IPv4 header} + {specified offset}.
- */
- s2 = new_stmt(BPF_LD|BPF_IND|size);
- s2->s.k = off_nl + offset;
- sappend(s, s2);
+ case DLT_BACNET_MS_TP:
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
break;
- case OR_TRAN_IPV6:
- s = new_stmt(BPF_LD|BPF_ABS|size);
- s->s.k = off_nl + 40 + offset;
+ case DLT_JUNIPER_SERVICES:
+ off_linktype.constant_part = 12;
+ off_linkpl.constant_part = -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 */
+ break;
+
+ case DLT_JUNIPER_VP:
+ off_linktype.constant_part = 18;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ break;
+
+ case DLT_JUNIPER_ST:
+ off_linktype.constant_part = 18;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ break;
+
+ case DLT_JUNIPER_ISM:
+ off_linktype.constant_part = 8;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ break;
+
+ case DLT_JUNIPER_VS:
+ case DLT_JUNIPER_SRX_E2E:
+ case DLT_JUNIPER_FIBRECHANNEL:
+ case DLT_JUNIPER_ATM_CEMIC:
+ off_linktype.constant_part = 8;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ break;
+
+ case DLT_MTP2:
+ off_li = 2;
+ off_li_hsl = 4;
+ off_sio = 3;
+ off_opc = 4;
+ off_dpc = 4;
+ off_sls = 7;
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ break;
+
+ case DLT_MTP2_WITH_PHDR:
+ off_li = 6;
+ off_li_hsl = 8;
+ off_sio = 7;
+ off_opc = 8;
+ off_dpc = 8;
+ off_sls = 11;
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ break;
+
+ case DLT_ERF:
+ off_li = 22;
+ off_li_hsl = 24;
+ off_sio = 23;
+ off_opc = 24;
+ off_dpc = 24;
+ off_sls = 27;
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ break;
+
+ case DLT_PFSYNC:
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = 4;
+ off_nl = 0;
+ off_nl_nosnap = 0;
+ break;
+
+ case DLT_AX25_KISS:
+ /*
+ * Currently, only raw "link[N:M]" filtering is supported.
+ */
+ off_linktype.constant_part = -1; /* variable, min 15, max 71 steps of 7 */
+ off_linkpl.constant_part = -1;
+ off_nl = -1; /* variable, min 16, max 71 steps of 7 */
+ off_nl_nosnap = -1; /* no 802.2 LLC */
+ break;
+
+ case DLT_IPNET:
+ off_linktype.constant_part = 1;
+ off_linkpl.constant_part = 24; /* ipnet header length */
+ off_nl = 0;
+ off_nl_nosnap = -1;
+ break;
+
+ case DLT_NETANALYZER:
+ off_linkhdr.constant_part = 4; /* Ethernet header is past 4-byte pseudo-header */
+ off_linktype.constant_part = off_linkhdr.constant_part + 12;
+ off_linkpl.constant_part = off_linkhdr.constant_part + 14; /* pseudo-header+Ethernet header length */
+ off_nl = 0; /* Ethernet II */
+ off_nl_nosnap = 3; /* 802.3+802.2 */
+ break;
+
+ case DLT_NETANALYZER_TRANSPARENT:
+ off_linkhdr.constant_part = 12; /* MAC header is past 4-byte pseudo-header, preamble, and SFD */
+ off_linktype.constant_part = off_linkhdr.constant_part + 12;
+ off_linkpl.constant_part = off_linkhdr.constant_part + 14; /* pseudo-header+preamble+SFD+Ethernet header length */
+ off_nl = 0; /* Ethernet II */
+ off_nl_nosnap = 3; /* 802.3+802.2 */
+ break;
+
+ default:
+ /*
+ * For values in the range in which we've assigned new
+ * DLT_ values, only raw "link[N:M]" filtering is supported.
+ */
+ if (linktype >= DLT_MATCHING_MIN &&
+ linktype <= DLT_MATCHING_MAX) {
+ off_linktype.constant_part = -1;
+ off_linkpl.constant_part = -1;
+ off_nl = -1;
+ off_nl_nosnap = -1;
+ } else {
+ bpf_error("unknown data link type %d", linktype);
+ }
+ break;
+ }
+
+ off_outermostlinkhdr = off_prevlinkhdr = off_linkhdr;
+}
+
+/*
+ * Load a value relative to the specified absolute offset.
+ */
+static struct slist *
+gen_load_absoffsetrel(bpf_abs_offset *abs_offset, u_int offset, u_int size)
+{
+ struct slist *s, *s2;
+
+ s = gen_abs_offset_varpart(abs_offset);
+
+ /*
+ * If "s" is non-null, it has code to arrange that the X register
+ * contains the variable part of the absolute offset, so we
+ * generate a load relative to that, with an offset of
+ * abs_offset->constant_part + offset.
+ *
+ * Otherwise, we can do an absolute load with an offset of
+ * abs_offset->constant_part + offset.
+ */
+ if (s != NULL) {
+ /*
+ * "s" points to a list of statements that puts the
+ * variable part of the absolute offset 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 = abs_offset->constant_part + offset;
+ sappend(s, s2);
+ } else {
+ /*
+ * There is no variable part of the absolute offset, so
+ * just do an absolute load.
+ */
+ s = new_stmt(BPF_LD|BPF_ABS|size);
+ s->s.k = abs_offset->constant_part + offset;
+ }
+ return s;
+}
+
+/*
+ * 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 slist *s, *s2;
+
+ switch (offrel) {
+
+ case OR_PACKET:
+ s = new_stmt(BPF_LD|BPF_ABS|size);
+ s->s.k = offset;
+ break;
+
+ case OR_LINKHDR:
+ s = gen_load_absoffsetrel(&off_linkhdr, offset, size);
+ break;
+
+ case OR_PREVLINKHDR:
+ s = gen_load_absoffsetrel(&off_prevlinkhdr, offset, size);
+ break;
+
+ case OR_LLC:
+ s = gen_load_absoffsetrel(&off_linkpl, offset, size);
+ break;
+
+ case OR_PREVMPLSHDR:
+ s = gen_load_absoffsetrel(&off_linkpl, off_nl - 4 + offset, size);
+ break;
+
+ case OR_LINKPL:
+ s = gen_load_absoffsetrel(&off_linkpl, off_nl + offset, size);
+ break;
+
+ case OR_LINKPL_NOSNAP:
+ s = gen_load_absoffsetrel(&off_linkpl, off_nl_nosnap + offset, size);
+ break;
+
+ case OR_LINKTYPE:
+ s = gen_load_absoffsetrel(&off_linktype, offset, size);
+ 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 link-layer payload} +
+ * {offset, relative to the start of the link-layer
+ * paylod, of the IPv4 header} + {length of the IPv4 header} +
+ * {specified offset}.
+ *
+ * If the offset of the link-layer payload is variable,
+ * the variable part of that offset is included in the
+ * value in the X register, and we include the constant
+ * part in the offset of the load.
+ */
+ s2 = new_stmt(BPF_LD|BPF_IND|size);
+ s2->s.k = off_linkpl.constant_part + off_nl + offset;
+ sappend(s, s2);
+ break;
+
+ case OR_TRAN_IPV6:
+ s = gen_load_absoffsetrel(&off_linkpl, off_nl + 40 + offset, size);
break;
default:
}
/*
- * Generate code to load into the X register the length of the IPv4
- * header in the packet.
+ * Generate code to load into the X register the sum of the length of
+ * the IPv4 header and the variable part of the offset of the link-layer
+ * payload.
*/
static struct slist *
gen_loadx_iphdrlen()
{
- struct slist *s;
+ struct slist *s, *s2;
+
+ s = gen_abs_offset_varpart(&off_linkpl);
+ if (s != NULL) {
+ /*
+ * The offset of the link-layer payload has a variable
+ * part. "s" points to a list of statements that put
+ * the variable part of that offset 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_linkpl.constant_part + 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);
- s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
- s->s.k = off_nl;
+ /*
+ * The A register now contains the length of the IP header.
+ * We need to add to it the variable part of the offset of
+ * the link-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 {
+ /*
+ * The offset of the link-layer payload is a constant,
+ * so no code was generated to load the (non-existent)
+ * variable part of that offset.
+ *
+ * This means we can use the 4*([k]&0xf) addressing
+ * mode. Load the length of the IPv4 header, which
+ * is at an offset of off_nl from the beginning of
+ * the link-layer payload, and thus at an offset of
+ * off_linkpl.constant_part + off_nl from the beginning
+ * of the raw packet data, using that addressing mode.
+ */
+ s = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
+ s->s.k = off_linkpl.constant_part + off_nl;
+ }
return s;
}
* DSAP, as we do for other types <= ETHERMTU
* (i.e., other SAP values)?
*/
- b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
+ b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
gen_not(b0);
- b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_H, (bpf_int32)
+ b1 = gen_cmp(OR_LLC, 0, BPF_H, (bpf_int32)
((proto << 8) | proto));
gen_and(b0, b1);
return b1;
* This generates code to check both for the
* IPX LSAP (Ethernet_802.2) and for Ethernet_802.3.
*/
- b0 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
- (bpf_int32)LLCSAP_IPX);
- b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_H,
- (bpf_int32)0xFFFF);
+ b0 = gen_cmp(OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
+ b1 = gen_cmp(OR_LLC, 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, 14);
+ 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);
+ b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
gen_not(b0);
/*
* do that before checking for the other frame
* types.
*/
- b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
- (bpf_int32)ETHERTYPE_IPX);
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX);
gen_or(b0, b1);
return b1;
* 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);
+ b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
gen_not(b0);
/*
* type of ETHERTYPE_AARP (Appletalk ARP).
*/
if (proto == ETHERTYPE_ATALK)
- b1 = gen_snap(0x080007, ETHERTYPE_ATALK, 14);
+ b1 = gen_snap(0x080007, ETHERTYPE_ATALK);
else /* proto == ETHERTYPE_AARP */
- b1 = gen_snap(0x000000, ETHERTYPE_AARP, 14);
+ b1 = gen_snap(0x000000, ETHERTYPE_AARP);
gen_and(b0, b1);
/*
* phase 1?); we just check for the Ethernet
* protocol type.
*/
- b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
gen_or(b0, b1);
return b1;
* a length field, <= ETHERMTU) and
* then check the DSAP.
*/
- b0 = gen_cmp_gt(OR_LINK, off_linktype, BPF_H, ETHERMTU);
+ b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
gen_not(b0);
- b1 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
- (bpf_int32)proto);
+ b1 = gen_cmp(OR_LINKTYPE, 2, BPF_B, (bpf_int32)proto);
gen_and(b0, b1);
return b1;
} else {
* will fail and the frame won't match,
* which is what we want).
*/
- return gen_cmp(OR_LINK, off_linktype, BPF_H,
+ return gen_cmp(OR_LINKTYPE, 0, BPF_H,
(bpf_int32)proto);
}
}
}
+/*
+ * "proto" is an Ethernet type value and for IPNET, if it is not IPv4
+ * or IPv6 then we have an error.
+ */
+static struct block *
+gen_ipnet_linktype(proto)
+ register int proto;
+{
+ switch (proto) {
+
+ case ETHERTYPE_IP:
+ return gen_cmp(OR_LINKTYPE, 0, BPF_B, (bpf_int32)IPH_AF_INET);
+ /* NOTREACHED */
+
+ case ETHERTYPE_IPV6:
+ return gen_cmp(OR_LINKTYPE, 0, BPF_B,
+ (bpf_int32)IPH_AF_INET6);
+ /* NOTREACHED */
+
+ default:
+ break;
+ }
+
+ return gen_false();
+}
+
/*
* Generate code to match a particular packet type.
*
* 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_LINK, off_linktype + 2, BPF_H, (bpf_int32)
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
+ b1 = gen_cmp(OR_LLC, 0, BPF_H, (bpf_int32)
((proto << 8) | proto));
gen_and(b0, b1);
return b1;
* then put a check for LINUX_SLL_P_802_2 frames
* before it.
*/
- b0 = gen_cmp(OR_LINK, off_linktype + 2, BPF_B,
- (bpf_int32)LLCSAP_IPX);
- b1 = gen_snap(0x000000, ETHERTYPE_IPX,
- off_linktype + 2);
+ b0 = gen_cmp(OR_LLC, 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);
+ b0 = gen_cmp(OR_LINKTYPE, 0, 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);
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_3);
gen_or(b0, b1);
/*
* do that before checking for the other frame
* types.
*/
- b0 = gen_cmp(OR_LINK, off_linktype, BPF_H,
- (bpf_int32)ETHERTYPE_IPX);
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX);
gen_or(b0, b1);
return b1;
* 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);
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
/*
* 802.2-encapsulated ETHERTYPE_ATALK packets are
* type of ETHERTYPE_AARP (Appletalk ARP).
*/
if (proto == ETHERTYPE_ATALK)
- b1 = gen_snap(0x080007, ETHERTYPE_ATALK,
- off_linktype + 2);
+ b1 = gen_snap(0x080007, ETHERTYPE_ATALK);
else /* proto == ETHERTYPE_AARP */
- b1 = gen_snap(0x000000, ETHERTYPE_AARP,
- off_linktype + 2);
+ b1 = gen_snap(0x000000, ETHERTYPE_AARP);
gen_and(b0, b1);
/*
* phase 1?); we just check for the Ethernet
* protocol type.
*/
- b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
gen_or(b0, b1);
return b1;
* 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_linktype + 2, BPF_B,
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
+ b1 = gen_cmp(OR_LINKHDR, off_linkpl.constant_part, BPF_B,
(bpf_int32)proto);
gen_and(b0, b1);
return b1;
* 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);
+ return gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)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;
+static struct slist *
+gen_load_prism_llprefixlen()
{
- struct block *b0, *b1, *b2;
-
- switch (linktype) {
-
- case DLT_EN10MB:
- return gen_ether_linktype(proto);
- /*NOTREACHED*/
- break;
+ struct slist *s1, *s2;
+ struct slist *sjeq_avs_cookie;
+ struct slist *sjcommon;
- case DLT_C_HDLC:
- switch (proto) {
+ /*
+ * This code is not compatible with the optimizer, as
+ * we are generating jmp instructions within a normal
+ * slist of instructions
+ */
+ no_optimize = 1;
- case LLCSAP_ISONS:
- proto = (proto << 8 | LLCSAP_ISONS);
- /* fall through */
+ /*
+ * 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 (off_linkhdr.reg != -1) {
+ /*
+ * Load the cookie.
+ */
+ s1 = new_stmt(BPF_LD|BPF_W|BPF_ABS);
+ s1->s.k = 0;
- default:
- return gen_cmp(OR_LINK, off_linktype, BPF_H,
- (bpf_int32)proto);
- /*NOTREACHED*/
- break;
- }
- break;
+ /*
+ * AND it with 0xFFFFF000.
+ */
+ s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K);
+ s2->s.k = 0xFFFFF000;
+ sappend(s1, s2);
- case DLT_IEEE802_11:
- case DLT_PRISM_HEADER:
- case DLT_IEEE802_11_RADIO:
- case DLT_FDDI:
- case DLT_IEEE802:
- case DLT_ATM_RFC1483:
- case DLT_ATM_CLIP:
- case DLT_IP_OVER_FC:
- return gen_llc_linktype(proto);
- /*NOTREACHED*/
- break;
+ /*
+ * Compare with 0x80211000.
+ */
+ sjeq_avs_cookie = new_stmt(JMP(BPF_JEQ));
+ sjeq_avs_cookie->s.k = 0x80211000;
+ sappend(s1, sjeq_avs_cookie);
- 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.
+ * If it's AVS:
*
- * We assume LANE means Ethernet, not Token Ring.
+ * 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.
*/
- 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);
+ s2 = new_stmt(BPF_LD|BPF_W|BPF_ABS);
+ s2->s.k = 4;
+ sappend(s1, s2);
+ sjeq_avs_cookie->s.jt = s2;
- /*
- * 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;
+ /*
+ * 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);
- case DLT_LINUX_SLL:
- return gen_linux_sll_linktype(proto);
- /*NOTREACHED*/
- break;
+ /*
+ * 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;
- case DLT_SLIP:
- case DLT_SLIP_BSDOS:
- case DLT_RAW:
/*
- * These types don't provide any type field; packets
- * are always IP.
- *
- * XXX - for IPv4, check for a version number of 4, and,
- * for IPv6, check for a version number of 6?
+ * 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.
*/
- switch (proto) {
+ s2 = new_stmt(BPF_ST);
+ s2->s.k = off_linkhdr.reg;
+ sappend(s1, s2);
+ sjcommon->s.jf = s2;
- case ETHERTYPE_IP:
-#ifdef INET6
- case ETHERTYPE_IPV6:
-#endif
- return gen_true(); /* always true */
+ /*
+ * 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 (off_linkhdr.reg != -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 = off_linkhdr.reg;
+ 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 (off_linkhdr.reg != -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 = off_linkhdr.reg;
+ 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 (off_linkhdr.reg != -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 = off_linkhdr.reg;
+ 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 (off_linkpl.reg == -1) {
+ /*
+ * No register has been assigned to the offset of
+ * the link-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_outermostlinkhdr.constant_part".
+ */
+ 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 off_linkpl.reg register.
+ * That length is off_outermostlinkhdr.constant_part.
+ */
+ s = new_stmt(BPF_LDX|BPF_IMM);
+ s->s.k = off_outermostlinkhdr.constant_part;
+ }
+
+ /*
+ * 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 off_linkpl.reg, 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 = off_linkpl.reg;
+ 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 off_linkpl.reg, 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 = off_linkpl.reg;
+ 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 = off_linkpl.reg;
+ 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 = off_linkpl.reg;
+ 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 = off_linkpl.reg;
+ 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;
+
+ /* There is an implicit dependency between the link
+ * payload and link header since the payload computation
+ * includes the variable part of the header. Therefore,
+ * if nobody else has allocated a register for the link
+ * header and we need it, do it now. */
+ if (off_linkpl.reg != -1 && off_linkhdr.is_variable &&
+ off_linkhdr.reg == -1)
+ off_linkhdr.reg = alloc_reg();
+
+ /*
+ * 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.
+ *
+ * XXX - this, and the next switch statement, won't handle
+ * encapsulation of 802.11 or 802.11+radio information in
+ * some other protocol stack. That's significantly more
+ * complicated.
+ */
+ switch (outermostlinktype) {
+
+ 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 link-layer
+ * payload into the register assigned to that offset, if any.
+ */
+ switch (outermostlinktype) {
+
+ 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;
+}
+
+/*
+ * Take an absolute offset, and:
+ *
+ * if it has no variable part, return NULL;
+ *
+ * if it has a variable part, generate code to load the register
+ * containing that variable part into the X register, returning
+ * a pointer to that code - if no register for that offset has
+ * been allocated, allocate it first.
+ *
+ * (The code to set that register will be generated later, but will
+ * be placed earlier in the code sequence.)
+ */
+static struct slist *
+gen_abs_offset_varpart(bpf_abs_offset *off)
+{
+ struct slist *s;
+
+ if (off->is_variable) {
+ if (off->reg == -1) {
+ /*
+ * We haven't yet assigned a register for the
+ * variable part of the offset of the link-layer
+ * header; allocate one.
+ */
+ off->reg = alloc_reg();
+ }
+
+ /*
+ * Load the register containing the variable part of the
+ * offset of the link-layer header into the X register.
+ */
+ s = new_stmt(BPF_LDX|BPF_MEM);
+ s->s.k = off->reg;
+ return s;
+ } else {
+ /*
+ * That offset isn't variable, there's no variable part,
+ * 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;
+
+ case ETHERTYPE_IPV6:
+ proto = PPP_IPV6;
+ break;
+
+ 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 any tests that, for encapsulation of a link-layer packet
+ * inside another protocol stack, need to be done to check for those
+ * link-layer packets (and that haven't already been done by a check
+ * for that encapsulation).
+ */
+static struct block *
+gen_prevlinkhdr_check(void)
+{
+ struct block *b0;
+
+ switch (prevlinktype) {
+
+ case DLT_SUNATM:
+ /*
+ * This is LANE-encapsulated Ethernet; check that the LANE
+ * packet doesn't begin with an LE Control marker, i.e.
+ * that it's data, not a control message.
+ *
+ * (We've already generated a test for LANE.)
+ */
+ b0 = gen_cmp(OR_PREVLINKHDR, SUNATM_PKT_BEGIN_POS, BPF_H, 0xFF00);
+ gen_not(b0);
+ return b0;
+
+ default:
+ /*
+ * No such tests are necessary.
+ */
+ return NULL;
+ }
+ /*NOTREACHED*/
+}
+
+/*
+ * 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;
+ const char *description;
+
+ /* 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 */
+ }
+ }
+
+ switch (linktype) {
+
+ case DLT_EN10MB:
+ case DLT_NETANALYZER:
+ case DLT_NETANALYZER_TRANSPARENT:
+ b0 = gen_prevlinkhdr_check();
+ b1 = gen_ether_linktype(proto);
+ if (b0 != NULL)
+ gen_and(b0, b1);
+ return b1;
+ /*NOTREACHED*/
+ break;
+
+ case DLT_C_HDLC:
+ switch (proto) {
+
+ case LLCSAP_ISONS:
+ proto = (proto << 8 | LLCSAP_ISONS);
+ /* fall through */
+
+ default:
+ return gen_cmp(OR_LINKTYPE, 0, 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 LLC frames.
+ */
+ 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;
- default:
- return gen_false(); /* always false */
- }
+ case DLT_ATM_RFC1483:
+ case DLT_ATM_CLIP:
+ case DLT_IP_OVER_FC:
+ return gen_llc_linktype(proto);
/*NOTREACHED*/
break;
- case DLT_PPP:
- case DLT_PPP_PPPD:
- case DLT_PPP_SERIAL:
- case DLT_PPP_ETHER:
+ case DLT_SUNATM:
/*
- * We use Ethernet protocol types inside libpcap;
- * map them to the corresponding PPP protocol types.
+ * Check for an LLC-encapsulated version of this protocol;
+ * if we were checking for LANE, linktype would no longer
+ * be DLT_SUNATM.
+ *
+ * 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:
- proto = PPP_IP;
- break;
+ /* Check for a version number of 4. */
+ return gen_mcmp(OR_LINKHDR, 0, BPF_B, 0x40, 0xF0);
-#ifdef INET6
case ETHERTYPE_IPV6:
- proto = PPP_IPV6;
- break;
-#endif
+ /* Check for a version number of 6. */
+ return gen_mcmp(OR_LINKHDR, 0, BPF_B, 0x60, 0xF0);
- case ETHERTYPE_DN:
- proto = PPP_DECNET;
- break;
+ default:
+ return gen_false(); /* always false */
+ }
+ /*NOTREACHED*/
+ break;
- case ETHERTYPE_ATALK:
- proto = PPP_APPLE;
- break;
+ case DLT_IPV4:
+ /*
+ * Raw IPv4, so no type field.
+ */
+ if (proto == ETHERTYPE_IP)
+ return gen_true(); /* always true */
- case ETHERTYPE_NS:
- proto = PPP_NS;
- break;
+ /* Checking for something other than IPv4; always false */
+ return gen_false();
+ /*NOTREACHED*/
+ break;
- case LLCSAP_ISONS:
- proto = PPP_OSI;
- break;
+ case DLT_IPV6:
+ /*
+ * Raw IPv6, so no type field.
+ */
+ if (proto == ETHERTYPE_IPV6)
+ return gen_true(); /* always true */
- case LLCSAP_8021D:
- /*
- * I'm assuming the "Bridging PDU"s that go
- * over PPP are Spanning Tree Protocol
- * Bridging PDUs.
- */
- proto = PPP_BRPDU;
- break;
+ /* Checking for something other than IPv6; always false */
+ return gen_false();
+ /*NOTREACHED*/
+ break;
- case LLCSAP_IPX:
- proto = PPP_IPX;
- 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_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
+ /*NOTREACHED*/
break;
case DLT_PPP_BSDOS:
switch (proto) {
case ETHERTYPE_IP:
- b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_IP);
- b1 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJC);
+ /*
+ * Also check for Van Jacobson-compressed IP.
+ * XXX - do this for other forms of PPP?
+ */
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, PPP_IP);
+ b1 = gen_cmp(OR_LINKTYPE, 0, BPF_H, PPP_VJC);
gen_or(b0, b1);
- b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, PPP_VJNC);
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, PPP_VJNC);
gen_or(b1, b0);
return b0;
-#ifdef INET6
- case ETHERTYPE_IPV6:
- proto = PPP_IPV6;
- /* more to go? */
- 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;
+ default:
+ proto = ethertype_to_ppptype(proto);
+ return gen_cmp(OR_LINKTYPE, 0, BPF_H,
+ (bpf_int32)proto);
}
+ /*NOTREACHED*/
break;
case DLT_NULL:
* Then we run it through "htonl()", and
* generate code to compare against the result.
*/
- if (bpf_pcap->sf.rfile != NULL &&
- bpf_pcap->sf.swapped)
+ if (bpf_pcap->rfile != NULL && bpf_pcap->swapped)
proto = SWAPLONG(proto);
proto = htonl(proto);
}
- return (gen_cmp(OR_LINK, 0, BPF_W, (bpf_int32)proto));
+ return (gen_cmp(OR_LINKHDR, 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),
+ return (gen_cmp(OR_LINKHDR, 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),
+ return (gen_cmp(OR_LINKHDR, 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:
default:
return gen_false();
-#ifdef INET6
case ETHERTYPE_IPV6:
- return (gen_cmp(OR_LINK, off_linktype, BPF_B,
+ return (gen_cmp(OR_LINKTYPE, 0, BPF_B,
(bpf_int32)ARCTYPE_INET6));
-#endif /* INET6 */
case ETHERTYPE_IP:
- b0 = gen_cmp(OR_LINK, off_linktype, BPF_B,
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_B,
(bpf_int32)ARCTYPE_IP);
- b1 = gen_cmp(OR_LINK, off_linktype, BPF_B,
+ b1 = gen_cmp(OR_LINKTYPE, 0, 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,
+ b0 = gen_cmp(OR_LINKTYPE, 0, BPF_B,
(bpf_int32)ARCTYPE_ARP);
- b1 = gen_cmp(OR_LINK, off_linktype, BPF_B,
+ b1 = gen_cmp(OR_LINKTYPE, 0, 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,
+ return (gen_cmp(OR_LINKTYPE, 0, BPF_B,
(bpf_int32)ARCTYPE_REVARP));
case ETHERTYPE_ATALK:
- return (gen_cmp(OR_LINK, off_linktype, BPF_B,
+ return (gen_cmp(OR_LINKTYPE, 0, BPF_B,
(bpf_int32)ARCTYPE_ATALK));
}
/*NOTREACHED*/
/*
* Check for the special NLPID for IP.
*/
- return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | 0xcc);
+ return gen_cmp(OR_LINKHDR, 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
+ return gen_cmp(OR_LINKHDR, 2, BPF_H, (0x03<<8) | 0x8e);
case LLCSAP_ISONS:
/*
* 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);
+ b0 = gen_cmp(OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO8473_CLNP);
+ b1 = gen_cmp(OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO9542_ESIS);
+ b2 = gen_cmp(OR_LINKHDR, 2, BPF_H, (0x03<<8) | ISO10589_ISIS);
gen_or(b1, b2);
gen_or(b0, b2);
return b2;
/*NOTREACHED*/
break;
- case DLT_JUNIPER_MLFR:
- case DLT_JUNIPER_MLPPP:
- case DLT_JUNIPER_ATM1:
- case DLT_JUNIPER_ATM2:
- /* 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_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:
+ case DLT_JUNIPER_VS:
+ case DLT_JUNIPER_SRX_E2E:
+ case DLT_JUNIPER_FIBRECHANNEL:
+ case DLT_JUNIPER_ATM_CEMIC:
+
+ /* 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_LINKHDR, 0, BPF_W, 0x4d474300, 0xffffff00); /* compare the magic number */
+
+ case DLT_BACNET_MS_TP:
+ return gen_mcmp(OR_LINKHDR, 0, BPF_W, 0x55FF0000, 0xffff0000);
+
+ case DLT_IPNET:
+ return gen_ipnet_linktype(proto);
+
+ 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");
+
+ case DLT_PFSYNC:
+ bpf_error("PFSYNC link-layer type filtering not implemented");
+
+ 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:
+ case DLT_CAN_SOCKETCAN:
+ bpf_error("CAN link-layer type filtering not implemented");
+
+ case DLT_IEEE802_15_4:
+ case DLT_IEEE802_15_4_LINUX:
+ case DLT_IEEE802_15_4_NONASK_PHY:
+ case DLT_IEEE802_15_4_NOFCS:
+ 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");
+
+ case DLT_NFLOG:
+ /* Using the fixed-size NFLOG header it is possible to tell only
+ * the address family of the packet, other meaningful data is
+ * either missing or behind TLVs.
+ */
+ bpf_error("NFLOG link-layer type filtering not implemented");
+
+ default:
+ /*
+ * Does this link-layer header type have a field
+ * indicating the type of the next protocol? If
+ * so, off_linktype.constant_part will be the offset of that
+ * field in the packet; if not, it will be -1.
+ */
+ if (off_linktype.constant_part != (u_int)-1) {
+ /*
+ * Yes; assume it's an Ethernet type. (If
+ * it's not, it needs to be handled specially
+ * above.)
+ */
+ return gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
+ } else {
+ /*
+ * No; report an error.
+ */
+ description = pcap_datalink_val_to_description(linktype);
+ if (description != NULL) {
+ bpf_error("%s link-layer type filtering not implemented",
+ description);
+ } else {
+ bpf_error("DLT %u link-layer type filtering not implemented",
+ linktype);
+ }
+ }
+ break;
+ }
+}
+
+/*
+ * 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_LLC, 0, 8, snapblock);
+}
+
+/*
+ * Generate code to match frames with an LLC header.
+ */
+struct block *
+gen_llc(void)
+{
+ struct block *b0, *b1;
+
+ switch (linktype) {
+
+ case DLT_EN10MB:
+ /*
+ * We check for an Ethernet type field less than
+ * 1500, which means it's an 802.3 length field.
+ */
+ b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
+ gen_not(b0);
+
+ /*
+ * Now check for the purported DSAP and SSAP not being
+ * 0xFF, to rule out NetWare-over-802.3.
+ */
+ b1 = gen_cmp(OR_LLC, 0, BPF_H, (bpf_int32)0xFFFF);
+ gen_not(b1);
+ gen_and(b0, b1);
+ return b1;
+
+ case DLT_SUNATM:
+ /*
+ * We check for LLC traffic.
+ */
+ b0 = gen_atmtype_abbrev(A_LLC);
+ return b0;
+
+ case DLT_IEEE802: /* Token Ring */
+ /*
+ * XXX - check for LLC frames.
+ */
+ return gen_true();
+
+ case DLT_FDDI:
+ /*
+ * XXX - check for LLC frames.
+ */
+ return gen_true();
+
+ case DLT_ATM_RFC1483:
+ /*
+ * For LLC encapsulation, these are defined to have an
+ * 802.2 LLC header.
+ *
+ * For VC encapsulation, they don't, but there's no
+ * way to check for that; the protocol used on the VC
+ * is negotiated out of band.
+ */
+ return gen_true();
+
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_PPI:
+ /*
+ * Check that we have a data frame.
+ */
+ b0 = gen_check_802_11_data_frame();
+ return b0;
+
+ default:
+ bpf_error("'llc' not supported for linktype %d", linktype);
+ /* NOTREACHED */
+ }
+}
+
+struct block *
+gen_llc_i(void)
+{
+ struct block *b0, *b1;
+ struct slist *s;
+
+ /*
+ * Check whether this is an LLC frame.
+ */
+ b0 = gen_llc();
+
+ /*
+ * Load the control byte and test the low-order bit; it must
+ * be clear for I frames.
+ */
+ s = gen_load_a(OR_LLC, 2, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x01;
+ b1->stmts = s;
+ gen_not(b1);
+ gen_and(b0, b1);
+ return b1;
+}
+
+struct block *
+gen_llc_s(void)
+{
+ struct block *b0, *b1;
+
+ /*
+ * Check whether this is an LLC frame.
+ */
+ b0 = gen_llc();
+
+ /*
+ * Now compare the low-order 2 bit of the control byte against
+ * the appropriate value for S frames.
+ */
+ b1 = gen_mcmp(OR_LLC, 2, BPF_B, LLC_S_FMT, 0x03);
+ gen_and(b0, b1);
+ return b1;
+}
+
+struct block *
+gen_llc_u(void)
+{
+ struct block *b0, *b1;
- case DLT_LINUX_IRDA:
- bpf_error("IrDA link-layer type filtering not implemented");
+ /*
+ * Check whether this is an LLC frame.
+ */
+ b0 = gen_llc();
- case DLT_DOCSIS:
- bpf_error("DOCSIS link-layer type filtering not implemented");
+ /*
+ * Now compare the low-order 2 bit of the control byte against
+ * the appropriate value for U frames.
+ */
+ b1 = gen_mcmp(OR_LLC, 2, BPF_B, LLC_U_FMT, 0x03);
+ gen_and(b0, b1);
+ return b1;
+}
- case DLT_LINUX_LAPD:
- bpf_error("LAPD link-layer type filtering not implemented");
- }
+struct block *
+gen_llc_s_subtype(bpf_u_int32 subtype)
+{
+ struct block *b0, *b1;
/*
- * 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.
+ * Check whether this is an LLC frame.
*/
- if (off_linktype == (u_int)-1)
- abort();
+ b0 = gen_llc();
/*
- * Any type not handled above should always have an Ethernet
- * type at an offset of "off_linktype". (PPP is partially
- * handled above - the protocol type is mapped from the
- * Ethernet and LLC types we use internally to the corresponding
- * PPP type - but the PPP type is always specified by a value
- * at "off_linktype", so we don't have to do the code generation
- * above.)
+ * Now check for an S frame with the appropriate type.
*/
- return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_int32)proto);
+ b1 = gen_mcmp(OR_LLC, 2, BPF_B, subtype, LLC_S_CMD_MASK);
+ gen_and(b0, b1);
+ return b1;
}
-/*
- * 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, offset)
- bpf_u_int32 orgcode;
- bpf_u_int32 ptype;
- u_int offset;
+struct block *
+gen_llc_u_subtype(bpf_u_int32 subtype)
{
- u_char snapblock[8];
+ struct block *b0, *b1;
- 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_LINK, offset, 8, snapblock);
+ /*
+ * Check whether this is an LLC frame.
+ */
+ b0 = gen_llc();
+
+ /*
+ * Now check for a U frame with the appropriate type.
+ */
+ b1 = gen_mcmp(OR_LLC, 2, BPF_B, subtype, LLC_U_CMD_MASK);
+ gen_and(b0, b1);
+ return b1;
}
/*
/*
* 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)?
+ * DSAP, as we do for other SAP values?
*/
- return gen_cmp(OR_LINK, off_linktype, BPF_H, (bpf_u_int32)
+ return gen_cmp(OR_LLC, 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_LINK, off_linktype, BPF_B,
+ return gen_cmp(OR_LLC, 0, BPF_B,
(bpf_int32)LLCSAP_IPX);
case ETHERTYPE_ATALK:
* XXX - check for an organization code of
* encapsulated Ethernet as well?
*/
- return gen_snap(0x080007, ETHERTYPE_ATALK, off_linktype);
+ return gen_snap(0x080007, ETHERTYPE_ATALK);
default:
/*
* This is an LLC SAP value, so check
* the DSAP.
*/
- return gen_cmp(OR_LINK, off_linktype, BPF_B,
- (bpf_int32)proto);
+ return gen_cmp(OR_LLC, 0, BPF_B, (bpf_int32)proto);
} else {
/*
* This is an Ethernet type; we assume that it's
* organization code of 0x000000 (encapsulated
* Ethernet), we'd do
*
- * return gen_snap(0x000000, proto,
- * off_linktype);
+ * 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_LINK, off_linktype+6, BPF_H,
- (bpf_int32)proto);
+ return gen_cmp(OR_LLC, 6, BPF_H, (bpf_int32)proto);
}
}
}
abort();
}
b0 = gen_linktype(proto);
- b1 = gen_mcmp(OR_NET, offset, BPF_W, (bpf_int32)addr, mask);
+ b1 = gen_mcmp(OR_LINKPL, offset, BPF_W, (bpf_int32)addr, mask);
gen_and(b0, b1);
return b1;
}
/* 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]));
+ b1 = gen_mcmp(OR_LINKPL, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3]));
+ b0 = gen_mcmp(OR_LINKPL, 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]));
+ b0 = gen_mcmp(OR_LINKPL, 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]));
+ b0 = gen_mcmp(OR_LINKPL, 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*/
+#endif
static struct block *
gen_ehostop(eaddr, dir)
switch (dir) {
case Q_SRC:
- return gen_bcmp(OR_LINK, off_mac + 6, 6, eaddr);
+ return gen_bcmp(OR_LINKHDR, 6, 6, eaddr);
case Q_DST:
- return gen_bcmp(OR_LINK, off_mac + 0, 6, eaddr);
+ return gen_bcmp(OR_LINKHDR, 0, 6, eaddr);
case Q_AND:
b0 = gen_ehostop(eaddr, Q_SRC);
b1 = gen_ehostop(eaddr, Q_DST);
gen_or(b0, b1);
return b1;
+
+ case Q_ADDR1:
+ bpf_error("'addr1' is only supported on 802.11 with 802.11 headers");
+ break;
+
+ case Q_ADDR2:
+ bpf_error("'addr2' is only supported on 802.11 with 802.11 headers");
+ break;
+
+ case Q_ADDR3:
+ bpf_error("'addr3' is only supported on 802.11 with 802.11 headers");
+ break;
+
+ case Q_ADDR4:
+ bpf_error("'addr4' is only supported on 802.11 with 802.11 headers");
+ break;
+
+ case Q_RA:
+ bpf_error("'ra' is only supported on 802.11 with 802.11 headers");
+ break;
+
+ case Q_TA:
+ bpf_error("'ta' is only supported on 802.11 with 802.11 headers");
+ break;
}
abort();
/* NOTREACHED */
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
+ return gen_bcmp(OR_LINKHDR, 6 + 1 + pcap_fddipad, 6, eaddr);
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
+ return gen_bcmp(OR_LINKHDR, 0 + 1 + pcap_fddipad, 6, eaddr);
case Q_AND:
b0 = gen_fhostop(eaddr, Q_SRC);
b1 = gen_fhostop(eaddr, Q_DST);
gen_or(b0, b1);
return b1;
+
+ case Q_ADDR1:
+ bpf_error("'addr1' is only supported on 802.11");
+ break;
+
+ case Q_ADDR2:
+ bpf_error("'addr2' is only supported on 802.11");
+ break;
+
+ case Q_ADDR3:
+ bpf_error("'addr3' is only supported on 802.11");
+ break;
+
+ case Q_ADDR4:
+ bpf_error("'addr4' is only supported on 802.11");
+ break;
+
+ case Q_RA:
+ bpf_error("'ra' is only supported on 802.11");
+ break;
+
+ case Q_TA:
+ bpf_error("'ta' is only supported on 802.11");
+ break;
}
abort();
/* NOTREACHED */
switch (dir) {
case Q_SRC:
- return gen_bcmp(OR_LINK, 8, 6, eaddr);
+ return gen_bcmp(OR_LINKHDR, 8, 6, eaddr);
case Q_DST:
- return gen_bcmp(OR_LINK, 2, 6, eaddr);
+ return gen_bcmp(OR_LINKHDR, 2, 6, eaddr);
case Q_AND:
b0 = gen_thostop(eaddr, Q_SRC);
b1 = gen_thostop(eaddr, Q_DST);
gen_or(b0, b1);
return b1;
+
+ case Q_ADDR1:
+ bpf_error("'addr1' is only supported on 802.11");
+ break;
+
+ case Q_ADDR2:
+ bpf_error("'addr2' is only supported on 802.11");
+ break;
+
+ case Q_ADDR3:
+ bpf_error("'addr3' is only supported on 802.11");
+ break;
+
+ case Q_ADDR4:
+ bpf_error("'addr4' is only supported on 802.11");
+ break;
+
+ case Q_RA:
+ bpf_error("'ra' is only supported on 802.11");
+ break;
+
+ case Q_TA:
+ bpf_error("'ta' is only supported on 802.11");
+ break;
}
abort();
/* NOTREACHED */
}
/*
- * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN)
+ * 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 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:
/*
*
* First, check for To DS set, i.e. check "link[1] & 0x01".
*/
- s = gen_load_a(OR_LINK, 1, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 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);
+ b0 = gen_bcmp(OR_LINKHDR, 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);
+ s = gen_load_a(OR_LINKHDR, 1, BPF_B);
b2 = new_block(JMP(BPF_JSET));
b2->s.k = 0x01; /* To DS */
b2->stmts = s;
/*
* If To DS is not set, the SA is at 16.
*/
- b1 = gen_bcmp(OR_LINK, 16, 6, eaddr);
+ b1 = gen_bcmp(OR_LINKHDR, 16, 6, eaddr);
gen_and(b2, b1);
/*
* Now check for From DS being set, and AND that with
* the ORed-together checks.
*/
- s = gen_load_a(OR_LINK, 1, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 1, BPF_B);
b1 = new_block(JMP(BPF_JSET));
b1->s.k = 0x02; /* From DS */
b1->stmts = s;
/*
* Now check for data frames with From DS not set.
*/
- s = gen_load_a(OR_LINK, 1, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 1, BPF_B);
b2 = new_block(JMP(BPF_JSET));
b2->s.k = 0x02; /* From DS */
b2->stmts = s;
/*
* If From DS isn't set, the SA is at 10.
*/
- b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
+ b1 = gen_bcmp(OR_LINKHDR, 10, 6, eaddr);
gen_and(b2, b1);
/*
* Now check for a data frame.
* I.e, check "link[0] & 0x08".
*/
- gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b1 = new_block(JMP(BPF_JSET));
b1->s.k = 0x08;
b1->stmts = s;
* is a management frame.
* I.e, check "!(link[0] & 0x08)".
*/
- s = gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b2 = new_block(JMP(BPF_JSET));
b2->s.k = 0x08;
b2->stmts = s;
/*
* For management frames, the SA is at 10.
*/
- b1 = gen_bcmp(OR_LINK, 10, 6, eaddr);
+ b1 = gen_bcmp(OR_LINKHDR, 10, 6, eaddr);
gen_and(b2, b1);
/*
*
* I.e., check "!(link[0] & 0x04)".
*/
- s = gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b1 = new_block(JMP(BPF_JSET));
b1->s.k = 0x04;
b1->stmts = s;
*
* First, check for To DS set, i.e. "link[1] & 0x01".
*/
- s = gen_load_a(OR_LINK, 1, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 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);
+ b0 = gen_bcmp(OR_LINKHDR, 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);
+ s = gen_load_a(OR_LINKHDR, 1, BPF_B);
b2 = new_block(JMP(BPF_JSET));
b2->s.k = 0x01; /* To DS */
b2->stmts = s;
/*
* If To DS is not set, the DA is at 4.
*/
- b1 = gen_bcmp(OR_LINK, 4, 6, eaddr);
+ b1 = gen_bcmp(OR_LINKHDR, 4, 6, eaddr);
gen_and(b2, b1);
/*
* Now check for a data frame.
* I.e, check "link[0] & 0x08".
*/
- s = gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b1 = new_block(JMP(BPF_JSET));
b1->s.k = 0x08;
b1->stmts = s;
* is a management frame.
* I.e, check "!(link[0] & 0x08)".
*/
- s = gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b2 = new_block(JMP(BPF_JSET));
b2->s.k = 0x08;
b2->stmts = s;
/*
* For management frames, the DA is at 4.
*/
- b1 = gen_bcmp(OR_LINK, 4, 6, eaddr);
+ b1 = gen_bcmp(OR_LINKHDR, 4, 6, eaddr);
gen_and(b2, b1);
/*
*
* I.e., check "!(link[0] & 0x04)".
*/
- s = gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b1 = new_block(JMP(BPF_JSET));
b1->s.k = 0x04;
b1->stmts = s;
gen_and(b1, b0);
return b0;
+ case Q_RA:
+ /*
+ * Not present in management frames; addr1 in other
+ * frames.
+ */
+
+ /*
+ * 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_LINKHDR, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x08;
+ b1->stmts = s;
+
+ /*
+ * Check addr1.
+ */
+ b0 = gen_bcmp(OR_LINKHDR, 4, 6, eaddr);
+
+ /*
+ * AND that with the check of addr1.
+ */
+ gen_and(b1, b0);
+ return (b0);
+
+ case Q_TA:
+ /*
+ * Not present in management frames; addr2, if present,
+ * in other frames.
+ */
+
+ /*
+ * Not present in CTS or ACK control frames.
+ */
+ b0 = gen_mcmp(OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
+ IEEE80211_FC0_TYPE_MASK);
+ gen_not(b0);
+ b1 = gen_mcmp(OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS,
+ IEEE80211_FC0_SUBTYPE_MASK);
+ gen_not(b1);
+ b2 = gen_mcmp(OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_ACK,
+ IEEE80211_FC0_SUBTYPE_MASK);
+ gen_not(b2);
+ gen_and(b1, b2);
+ gen_or(b0, b2);
+
+ /*
+ * 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_LINKHDR, 0, BPF_B);
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x08;
+ b1->stmts = s;
+
+ /*
+ * AND that with the check for frames other than
+ * CTS and ACK frames.
+ */
+ gen_and(b1, b2);
+
+ /*
+ * Check addr2.
+ */
+ b1 = gen_bcmp(OR_LINKHDR, 10, 6, eaddr);
+ gen_and(b2, b1);
+ return b1;
+
+ /*
+ * XXX - add BSSID keyword?
+ */
+ case Q_ADDR1:
+ return (gen_bcmp(OR_LINKHDR, 4, 6, eaddr));
+
+ case Q_ADDR2:
+ /*
+ * Not present in CTS or ACK control frames.
+ */
+ b0 = gen_mcmp(OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
+ IEEE80211_FC0_TYPE_MASK);
+ gen_not(b0);
+ b1 = gen_mcmp(OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_SUBTYPE_CTS,
+ IEEE80211_FC0_SUBTYPE_MASK);
+ gen_not(b1);
+ b2 = gen_mcmp(OR_LINKHDR, 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_LINKHDR, 10, 6, eaddr);
+ gen_and(b2, b1);
+ return b1;
+
+ case Q_ADDR3:
+ /*
+ * Not present in control frames.
+ */
+ b0 = gen_mcmp(OR_LINKHDR, 0, BPF_B, IEEE80211_FC0_TYPE_CTL,
+ IEEE80211_FC0_TYPE_MASK);
+ gen_not(b0);
+ b1 = gen_bcmp(OR_LINKHDR, 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_LINKHDR, 1, BPF_B,
+ IEEE80211_FC1_DIR_DSTODS, IEEE80211_FC1_DIR_MASK);
+ b1 = gen_bcmp(OR_LINKHDR, 24, 6, eaddr);
+ gen_and(b0, b1);
+ return b1;
+
case Q_AND:
b0 = gen_wlanhostop(eaddr, Q_SRC);
b1 = gen_wlanhostop(eaddr, Q_DST);
switch (dir) {
case Q_SRC:
- return gen_bcmp(OR_LINK, 10, 6, eaddr);
+ return gen_bcmp(OR_LINKHDR, 10, 6, eaddr);
case Q_DST:
- return gen_bcmp(OR_LINK, 2, 6, eaddr);
+ return gen_bcmp(OR_LINKHDR, 2, 6, eaddr);
case Q_AND:
b0 = gen_ipfchostop(eaddr, Q_SRC);
b1 = gen_ipfchostop(eaddr, Q_DST);
gen_or(b0, b1);
return b1;
+
+ case Q_ADDR1:
+ bpf_error("'addr1' is only supported on 802.11");
+ break;
+
+ case Q_ADDR2:
+ bpf_error("'addr2' is only supported on 802.11");
+ break;
+
+ case Q_ADDR3:
+ bpf_error("'addr3' is only supported on 802.11");
+ break;
+
+ case Q_ADDR4:
+ bpf_error("'addr4' is only supported on 802.11");
+ break;
+
+ case Q_RA:
+ bpf_error("'ra' is only supported on 802.11");
+ break;
+
+ case Q_TA:
+ bpf_error("'ta' is only supported on 802.11");
+ break;
}
abort();
/* NOTREACHED */
}
b0 = gen_linktype(ETHERTYPE_DN);
/* Check for pad = 1, long header case */
- tmp = gen_mcmp(OR_NET, 2, BPF_H,
+ tmp = gen_mcmp(OR_LINKPL, 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(addr));
+ b1 = gen_cmp(OR_LINKPL, 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(addr));
+ tmp = gen_mcmp(OR_LINKPL, 2, BPF_B, (bpf_int32)0x06, (bpf_int32)0x7);
+ b2 = gen_cmp(OR_LINKPL, 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,
+ tmp = gen_mcmp(OR_LINKPL, 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(addr));
+ b2 = gen_cmp(OR_LINKPL, 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(addr));
+ tmp = gen_mcmp(OR_LINKPL, 2, BPF_B, (bpf_int32)0x02, (bpf_int32)0x7);
+ b2 = gen_cmp(OR_LINKPL, 2 + offset_sh, BPF_H, (bpf_int32)ntohs((u_short)addr));
gen_and(tmp, b2);
gen_or(b2, 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_LINKPL, -2, BPF_B, 0x01, 0x01);
+ /* match the IPv4 version number */
+ b1 = gen_mcmp(OR_LINKPL, 0, BPF_B, 0x40, 0xf0);
+ gen_and(b0, b1);
+ return b1;
+
+ case Q_IPV6:
+ /* match the bottom-of-stack bit */
+ b0 = gen_mcmp(OR_LINKPL, -2, BPF_B, 0x01, 0x01);
+ /* match the IPv4 version number */
+ b1 = gen_mcmp(OR_LINKPL, 0, BPF_B, 0x60, 0xf0);
+ gen_and(b0, b1);
+ return b1;
+
+ default:
+ abort();
+ }
+}
+
static struct block *
-gen_host(addr, mask, proto, dir)
+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);
- if (off_linktype != (u_int)-1) {
- b1 = gen_host(addr, mask, Q_ARP, dir);
- gen_or(b0, b1);
- b0 = gen_host(addr, mask, Q_RARP, dir);
- gen_or(b1, b0);
+ 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;
return gen_hostop(addr, mask, dir, ETHERTYPE_ARP, 14, 24);
case Q_TCP:
- bpf_error("'tcp' modifier applied to host");
+ bpf_error("'tcp' modifier applied to %s", typestr);
case Q_SCTP:
- bpf_error("'sctp' modifier applied to host");
+ bpf_error("'sctp' modifier applied to %s", typestr);
case Q_UDP:
- bpf_error("'udp' modifier applied to host");
+ bpf_error("'udp' modifier applied to %s", typestr);
case Q_ICMP:
- bpf_error("'icmp' modifier applied to host");
+ bpf_error("'icmp' modifier applied to %s", typestr);
case Q_IGMP:
- bpf_error("'igmp' modifier applied to host");
+ bpf_error("'igmp' modifier applied to %s", typestr);
case Q_IGRP:
- bpf_error("'igrp' modifier applied to host");
+ bpf_error("'igrp' modifier applied to %s", typestr);
case Q_PIM:
- bpf_error("'pim' modifier applied to host");
+ bpf_error("'pim' modifier applied to %s", typestr);
case Q_VRRP:
- bpf_error("'vrrp' modifier applied to host");
+ bpf_error("'vrrp' modifier applied to %s", typestr);
+
+ case Q_CARP:
+ bpf_error("'carp' modifier applied to %s", typestr);
case Q_ATALK:
bpf_error("ATALK 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 host");
-#endif /* INET6 */
+ bpf_error("'icmp6' modifier applied to %s", typestr);
case Q_AH:
- bpf_error("'ah' modifier applied to host");
+ bpf_error("'ah' modifier applied to %s", typestr);
case Q_ESP:
- bpf_error("'esp' modifier applied to host");
+ 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 host");
+ bpf_error("'esis' modifier applied to %s", typestr);
case Q_ISIS:
- bpf_error("'isis' modifier applied to host");
+ bpf_error("'isis' modifier applied to %s", typestr);
case Q_CLNP:
- bpf_error("'clnp' modifier applied to host");
+ bpf_error("'clnp' modifier applied to %s", typestr);
case Q_STP:
- bpf_error("'stp' modifier applied to host");
+ 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 host");
+ bpf_error("'netbeui' modifier applied to %s", typestr);
+
+ case Q_RADIO:
+ bpf_error("'radio' modifier applied to %s", typestr);
default:
abort();
#ifdef INET6
static struct block *
-gen_host6(addr, mask, proto, dir)
+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);
+ return gen_host6(addr, mask, Q_IPV6, dir, type);
+
+ case Q_LINK:
+ bpf_error("link-layer modifier applied to ip6 %s", typestr);
case Q_IP:
- bpf_error("'ip' modifier applied to ip6 host");
+ bpf_error("'ip' modifier applied to ip6 %s", typestr);
case Q_RARP:
- bpf_error("'rarp' modifier applied to ip6 host");
+ bpf_error("'rarp' modifier applied to ip6 %s", typestr);
case Q_ARP:
- bpf_error("'arp' modifier applied to ip6 host");
+ bpf_error("'arp' modifier applied to ip6 %s", typestr);
case Q_SCTP:
- bpf_error("'sctp' modifier applied to host");
+ bpf_error("'sctp' modifier applied to %s", typestr);
case Q_TCP:
- bpf_error("'tcp' modifier applied to host");
+ bpf_error("'tcp' modifier applied to %s", typestr);
case Q_UDP:
- bpf_error("'udp' modifier applied to host");
+ bpf_error("'udp' modifier applied to %s", typestr);
case Q_ICMP:
- bpf_error("'icmp' modifier applied to host");
+ bpf_error("'icmp' modifier applied to %s", typestr);
case Q_IGMP:
- bpf_error("'igmp' modifier applied to host");
+ bpf_error("'igmp' modifier applied to %s", typestr);
case Q_IGRP:
- bpf_error("'igrp' modifier applied to host");
+ bpf_error("'igrp' modifier applied to %s", typestr);
case Q_PIM:
- bpf_error("'pim' modifier applied to host");
+ bpf_error("'pim' modifier applied to %s", typestr);
case Q_VRRP:
- bpf_error("'vrrp' modifier applied to host");
+ bpf_error("'vrrp' modifier applied to %s", typestr);
+
+ case Q_CARP:
+ bpf_error("'carp' modifier applied to %s", typestr);
case Q_ATALK:
bpf_error("ATALK host filtering not implemented");
bpf_error("AARP host filtering not implemented");
case Q_DECNET:
- bpf_error("'decnet' modifier applied to ip6 host");
+ bpf_error("'decnet' modifier applied to ip6 %s", typestr);
case Q_SCA:
bpf_error("SCA host filtering not implemented");
return gen_hostop6(addr, mask, dir, ETHERTYPE_IPV6, 8, 24);
case Q_ICMPV6:
- bpf_error("'icmp6' modifier applied to host");
+ bpf_error("'icmp6' modifier applied to %s", typestr);
case Q_AH:
- bpf_error("'ah' modifier applied to host");
+ bpf_error("'ah' modifier applied to %s", typestr);
case Q_ESP:
- bpf_error("'esp' modifier applied to host");
+ 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 host");
+ bpf_error("'esis' modifier applied to %s", typestr);
case Q_ISIS:
- bpf_error("'isis' modifier applied to host");
+ bpf_error("'isis' modifier applied to %s", typestr);
case Q_CLNP:
- bpf_error("'clnp' modifier applied to host");
+ bpf_error("'clnp' modifier applied to %s", typestr);
case Q_STP:
- bpf_error("'stp' modifier applied to host");
+ 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 host");
+ bpf_error("'netbeui' modifier applied to %s", typestr);
+
+ case Q_RADIO:
+ bpf_error("'radio' modifier applied to %s", typestr);
default:
abort();
}
/* NOTREACHED */
}
-#endif /*INET6*/
+#endif
#ifndef INET6
static struct block *
case Q_IP:
case Q_ARP:
case Q_RARP:
- if (linktype == DLT_EN10MB)
+ switch (linktype) {
+ case DLT_EN10MB:
+ case DLT_NETANALYZER:
+ case DLT_NETANALYZER_TRANSPARENT:
+ b1 = gen_prevlinkhdr_check();
b0 = gen_ehostop(eaddr, Q_OR);
- else if (linktype == DLT_FDDI)
+ if (b1 != NULL)
+ gen_and(b1, b0);
+ break;
+ case DLT_FDDI:
b0 = gen_fhostop(eaddr, Q_OR);
- else if (linktype == DLT_IEEE802)
+ break;
+ case DLT_IEEE802:
b0 = gen_thostop(eaddr, Q_OR);
- else if (linktype == DLT_IEEE802_11)
+ 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);
- else if (linktype == DLT_SUNATM && 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);
-
+ break;
+ case DLT_SUNATM:
/*
- * Now check the MAC address.
+ * This is LLC-multiplexed traffic; if it were
+ * LANE, linktype would have been set to
+ * DLT_EN10MB.
*/
- b0 = gen_ehostop(eaddr, Q_OR);
- gen_and(b1, b0);
- } else if (linktype == DLT_IP_OVER_FC)
+ bpf_error(
+ "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
+ break;
+ case DLT_IP_OVER_FC:
b0 = gen_ipfchostop(eaddr, Q_OR);
- else
+ break;
+ default:
bpf_error(
- "'gateway' supported only on ethernet/FDDI/token ring/802.11/Fibre Channel");
-
- b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR);
+ "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
+ }
+ b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR, Q_HOST);
while (*alist) {
- tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR);
+ tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR,
+ Q_HOST);
gen_or(b1, tmp);
b1 = tmp;
}
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:
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
b1 = gen_proto(IPPROTO_VRRP, Q_IP, Q_DEFAULT);
break;
+#ifndef IPPROTO_CARP
+#define IPPROTO_CARP 112
+#endif
+
+ case Q_CARP:
+ b1 = gen_proto(IPPROTO_CARP, Q_IP, Q_DEFAULT);
+ break;
+
case Q_IP:
b1 = gen_linktype(ETHERTYPE_IP);
break;
b1 = gen_linktype(ETHERTYPE_MOPRC);
break;
-#ifdef INET6
case Q_IPV6:
b1 = gen_linktype(ETHERTYPE_IPV6);
break;
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
#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_NETBEUI);
break;
+ case Q_RADIO:
+ bpf_error("'radio' is not a valid protocol type");
+
default:
abort();
}
struct slist *s;
struct block *b;
- /* not ip frag */
- s = gen_load_a(OR_NET, 6, BPF_H);
+ /* not IPv4 frag other than the first frag */
+ s = gen_load_a(OR_LINKPL, 6, BPF_H);
b = new_block(JMP(BPF_JSET));
b->s.k = 0x1fff;
b->stmts = s;
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;
return gen_cmp(OR_TRAN_IPV4, off, BPF_H, v);
}
-#ifdef INET6
static struct block *
gen_portatom6(off, v)
int off;
{
return gen_cmp(OR_TRAN_IPV6, off, BPF_H, v);
}
-#endif/*INET6*/
struct block *
gen_portop(port, proto, dir)
{
struct block *b0, *b1, *tmp;
- /* ip proto 'proto' */
- tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto);
+ /* ip proto 'proto' and not a fragment other than the first fragment */
+ tmp = gen_cmp(OR_LINKPL, 9, BPF_B, (bpf_int32)proto);
b0 = gen_ipfrag();
gen_and(tmp, b0);
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);
+ /* XXX - catch the first fragment of a fragmented packet? */
+ b0 = gen_cmp(OR_LINKPL, 6, BPF_B, (bpf_int32)proto);
switch (dir) {
case Q_SRC:
gen_and(b0, b1);
return b1;
}
-#endif /* INET6 */
/* gen_portrange code */
static struct block *
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);
+ gen_and(b1, b2);
return b2;
}
{
struct block *b0, *b1, *tmp;
- /* ip proto 'proto' */
- tmp = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)proto);
+ /* ip proto 'proto' and not a fragment other than the first fragment */
+ tmp = gen_cmp(OR_LINKPL, 9, BPF_B, (bpf_int32)proto);
b0 = gen_ipfrag();
gen_and(tmp, b0);
return b1;
}
-#ifdef INET6
static struct block *
gen_portrangeatom6(off, v1, v2)
int off;
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);
+ gen_and(b1, b2);
return b2;
}
struct block *b0, *b1, *tmp;
/* ip6 proto 'proto' */
- b0 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)proto);
+ /* XXX - catch the first fragment of a fragmented packet? */
+ b0 = gen_cmp(OR_LINKPL, 6, BPF_B, (bpf_int32)proto);
switch (dir) {
case Q_SRC:
gen_and(b0, b1);
return b1;
}
-#endif /* INET6 */
static int
lookup_proto(name, proto)
/*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.)
+ */
+ if (off_linkpl.is_variable)
+ bpf_error("'protochain' not supported with variable length headers");
+
no_optimize = 1; /*this code is not compatible with optimzer yet */
/*
/* A = ip->ip_p */
s[i] = new_stmt(BPF_LD|BPF_ABS|BPF_B);
- s[i]->s.k = off_nl + 9;
+ s[i]->s.k = off_linkpl.constant_part + off_nl + 9;
i++;
/* X = ip->ip_hl << 2 */
s[i] = new_stmt(BPF_LDX|BPF_MSH|BPF_B);
- s[i]->s.k = off_nl;
+ s[i]->s.k = off_linkpl.constant_part + 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_nl + 6;
+ s[i]->s.k = off_linkpl.constant_part + 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*/
fix2 = i;
i++;
-#ifdef INET6
if (proto == Q_IPV6) {
int v6start, v6end, v6advance, j;
/*
* in short,
- * A = P[X];
- * X = X + (P[X + 1] + 1) * 8;
+ * A = P[X + packet head];
+ * X = X + (P[X + packet head + 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_nl;
+ s[i]->s.k = off_linkpl.constant_part + 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]; */
+ /* A = P[X + packet head + 1]; */
s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
- s[i]->s.k = off_nl;
+ s[i]->s.k = off_linkpl.constant_part + off_nl + 1;
i++;
/* A += 1 */
s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
s[i] = new_stmt(BPF_ALU|BPF_MUL|BPF_K);
s[i]->s.k = 8;
i++;
+ /* A += X */
+ s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_X);
+ s[i]->s.k = 0;
+ i++;
/* X = A; */
s[i] = new_stmt(BPF_MISC|BPF_TAX);
i++;
/* fixup */
for (j = v6start; j <= v6end; j++)
s[j]->s.jt = s[v6advance];
- } else
-#endif
- {
+ } else {
/* nop */
s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
s[i]->s.k = 0;
i++;
/* A = P[X + packet head]; */
s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
- s[i]->s.k = off_nl;
+ s[i]->s.k = off_linkpl.constant_part + off_nl;
i++;
/* MEM[reg2] = A */
s[i] = new_stmt(BPF_ST);
i++;
/* A = P[X + packet head] */
s[i] = new_stmt(BPF_LD|BPF_IND|BPF_B);
- s[i]->s.k = off_nl;
+ s[i]->s.k = off_linkpl.constant_part + off_nl;
i++;
/* A += 2 */
s[i] = new_stmt(BPF_ALU|BPF_ADD|BPF_K);
#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_LINKHDR, 0, BPF_B);
+ b0 = new_block(JMP(BPF_JSET));
+ b0->s.k = 0x08;
+ b0->stmts = s;
+
+ s = gen_load_a(OR_LINKHDR, 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
int dir;
{
struct block *b0, *b1;
+#ifndef CHASE_CHAIN
+ struct block *b2;
+#endif
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,
*/
b0 = gen_linktype(ETHERTYPE_IP);
#ifndef CHASE_CHAIN
- b1 = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)v);
+ b1 = gen_cmp(OR_LINKPL, 9, BPF_B, (bpf_int32)v);
#else
b1 = gen_protochain(v, Q_IP);
#endif
*
* XXX - what about SNAP-encapsulated frames?
*/
- return gen_cmp(OR_LINK, 2, BPF_H, (0x03<<8) | v);
+ return gen_cmp(OR_LINKHDR, 2, BPF_H, (0x03<<8) | v);
/*NOTREACHED*/
break;
*/
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);
+ b1 = gen_cmp(OR_LINKPL_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);
+ b1 = gen_cmp(OR_LINKPL_NOSNAP, 0, BPF_B, (long)v);
gen_and(b0, b1);
return b1;
}
* 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);
+ b1 = gen_cmp(OR_LINKPL_NOSNAP, 4, BPF_B, (long)v);
gen_and(b0, b1);
return b1;
bpf_error("'vrrp proto' is bogus");
/* NOTREACHED */
-#ifdef INET6
+ case Q_CARP:
+ bpf_error("'carp proto' is bogus");
+ /* NOTREACHED */
+
case Q_IPV6:
b0 = gen_linktype(ETHERTYPE_IPV6);
#ifndef CHASE_CHAIN
- b1 = gen_cmp(OR_NET, 6, BPF_B, (bpf_int32)v);
+ /*
+ * Also check for a fragment header before the final
+ * header.
+ */
+ b2 = gen_cmp(OR_LINKPL, 6, BPF_B, IPPROTO_FRAGMENT);
+ b1 = gen_cmp(OR_LINKPL, 40, BPF_B, (bpf_int32)v);
+ gen_and(b2, b1);
+ b2 = gen_cmp(OR_LINKPL, 6, BPF_B, (bpf_int32)v);
+ gen_or(b2, b1);
#else
b1 = gen_protochain(v, Q_IPV6);
#endif
case Q_ICMPV6:
bpf_error("'icmp6 proto' is bogus");
-#endif /* INET6 */
case Q_AH:
bpf_error("'ah proto' is bogus");
case Q_NETBEUI:
bpf_error("'netbeui proto' is bogus");
+ case Q_RADIO:
+ bpf_error("'radio proto' is bogus");
+
default:
abort();
/* NOTREACHED */
bpf_u_int32 **alist;
#else
int tproto6;
- struct sockaddr_in *sin;
+ struct sockaddr_in *sin4;
struct sockaddr_in6 *sin6;
struct addrinfo *res, *res0;
struct in6_addr mask128;
addr <<= 8;
mask <<= 8;
}
- return gen_host(addr, mask, proto, dir);
+ return gen_host(addr, mask, proto, dir, q.addr);
case Q_DEFAULT:
case Q_HOST:
switch (linktype) {
case DLT_EN10MB:
+ case DLT_NETANALYZER:
+ case DLT_NETANALYZER_TRANSPARENT:
eaddr = pcap_ether_hostton(name);
if (eaddr == NULL)
bpf_error(
"unknown ether host '%s'", name);
+ tmp = gen_prevlinkhdr_check();
b = gen_ehostop(eaddr, dir);
+ if (tmp != NULL)
+ gen_and(tmp, b);
free(eaddr);
return b;
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(
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");
* 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));
+ 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)
+ if (off_linktype.constant_part == (u_int)-1 &&
+ tproto == Q_DEFAULT)
tproto = Q_IP;
- b = gen_host(**alist++, 0xffffffff, tproto, dir);
+ b = gen_host(**alist++, 0xffffffff, tproto, dir, q.addr);
while (*alist) {
tmp = gen_host(**alist++, 0xffffffff,
- tproto, dir);
+ tproto, dir, q.addr);
gen_or(b, tmp);
b = tmp;
}
res0 = res = pcap_nametoaddrinfo(name);
if (res == NULL)
bpf_error("unknown host '%s'", name);
+ ai = res;
b = tmp = NULL;
tproto = tproto6 = proto;
- if (off_linktype == -1 && tproto == Q_DEFAULT) {
+ if (off_linktype.constant_part == -1 &&
+ tproto == Q_DEFAULT) {
tproto = Q_IP;
tproto6 = Q_IPV6;
}
if (tproto == Q_IPV6)
continue;
- sin = (struct sockaddr_in *)
+ sin4 = (struct sockaddr_in *)
res->ai_addr;
- tmp = gen_host(ntohl(sin->sin_addr.s_addr),
- 0xffffffff, tproto, dir);
+ tmp = gen_host(ntohl(sin4->sin_addr.s_addr),
+ 0xffffffff, tproto, dir, q.addr);
break;
case AF_INET6:
if (tproto6 == Q_IP)
sin6 = (struct sockaddr_in6 *)
res->ai_addr;
tmp = gen_host6(&sin6->sin6_addr,
- &mask128, tproto6, dir);
+ &mask128, tproto6, dir, q.addr);
break;
default:
continue;
gen_or(b, tmp);
b = tmp;
}
+ ai = NULL;
freeaddrinfo(res0);
if (b == NULL) {
bpf_error("unknown host '%s'%s", name,
/* override PROTO_UNDEF */
real_proto = IPPROTO_SCTP;
}
-#ifndef INET6
- return gen_port(port, real_proto, dir);
-#else
- {
- struct block *b;
+ if (port < 0)
+ bpf_error("illegal port number %d < 0", port);
+ if (port > 65535)
+ bpf_error("illegal port number %d > 65535", port);
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)
+ 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
/* override PROTO_UNDEF */
- real_proto = IPPROTO_SCTP;
+ real_proto = IPPROTO_SCTP;
}
-#ifndef INET6
- return gen_portrange(port1, port2, real_proto, dir);
-#else
- {
- struct block *b;
+ if (port1 < 0)
+ bpf_error("illegal port number %d < 0", port1);
+ if (port1 > 65535)
+ bpf_error("illegal port number %d > 65535", port1);
+ if (port2 < 0)
+ bpf_error("illegal port number %d < 0", port2);
+ if (port2 > 65535)
+ bpf_error("illegal port number %d > 65535", port2);
+
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
else
bpf_error("unknown protocol: %s", name);
-
case Q_UNDEF:
syntax();
/* NOTREACHED */
struct block *
gen_mcode(s1, s2, masklen, q)
register const char *s1, *s2;
- register int masklen;
+ register unsigned int masklen;
struct qual q;
{
register int nlen, mlen;
/* Convert mask len to mask */
if (masklen > 32)
bpf_error("mask length must be <= 32");
- m = 0xffffffff << (32 - masklen);
+ 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);
+ 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 *
case Q_HOST:
case Q_NET:
if (proto == Q_DECNET)
- return gen_host(v, 0, proto, dir);
+ return gen_host(v, 0, proto, dir, q.addr);
else if (proto == Q_LINK) {
bpf_error("illegal link layer address");
} else {
v <<= 32 - vlen;
mask <<= 32 - vlen;
}
- return gen_host(v, mask, proto, dir);
+ return gen_host(v, mask, proto, dir, q.addr);
}
case Q_PORT:
else
bpf_error("illegal qualifier of 'port'");
-#ifndef INET6
- return gen_port((int)v, proto, dir);
-#else
+ if (v > 65535)
+ bpf_error("illegal port number %u > 65535", v);
+
{
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)
else
bpf_error("illegal qualifier of 'portrange'");
-#ifndef INET6
- return gen_portrange((int)v, (int)v, proto, dir);
-#else
+ if (v > 65535)
+ bpf_error("illegal port number %u > 65535", v);
+
{
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");
struct block *
gen_mcode6(s1, s2, masklen, q)
register const char *s1, *s2;
- register int masklen;
+ register unsigned int masklen;
struct qual q;
{
struct addrinfo *res;
res = pcap_nametoaddrinfo(s1);
if (!res)
bpf_error("invalid ip6 address %s", s1);
+ ai = res;
if (res->ai_next)
bpf_error("%s resolved to multiple address", s1);
addr = &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
/* FALLTHROUGH */
case Q_NET:
- b = gen_host6(addr, &mask, q.proto, q.dir);
+ b = gen_host6(addr, &mask, q.proto, q.dir, q.addr);
+ ai = NULL;
freeaddrinfo(res);
return b;
bpf_error("invalid qualifier against IPv6 address");
/* NOTREACHED */
}
+ return NULL;
}
#endif /*INET6*/
struct block *b, *tmp;
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)
+ switch (linktype) {
+ case DLT_EN10MB:
+ case DLT_NETANALYZER:
+ case DLT_NETANALYZER_TRANSPARENT:
+ tmp = gen_prevlinkhdr_check();
+ b = gen_ehostop(eaddr, (int)q.dir);
+ if (tmp != NULL)
+ gen_and(tmp, b);
+ return b;
+ case DLT_FDDI:
return gen_fhostop(eaddr, (int)q.dir);
- if (linktype == DLT_IEEE802)
+ case DLT_IEEE802:
return gen_thostop(eaddr, (int)q.dir);
- if (linktype == DLT_IEEE802_11)
+ 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);
- if (linktype == DLT_SUNATM && 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;
- }
- if (linktype == DLT_IP_OVER_FC)
+ case DLT_IP_OVER_FC:
return gen_ipfchostop(eaddr, (int)q.dir);
- bpf_error("ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
+ default:
+ bpf_error("ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
+ break;
+ }
}
bpf_error("ethernet address used in non-ether expression");
/* NOTREACHED */
+ return NULL;
}
void
return s;
}
+/*
+ * 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".
+ */
struct arth *
-gen_load(proto, index, size)
+gen_load(proto, inst, size)
int proto;
- struct arth *index;
+ struct arth *inst;
int size;
{
struct slist *s, *tmp;
struct block *b;
int regno = alloc_reg();
- free_reg(index->regno);
+ free_reg(inst->regno);
switch (size) {
default:
default:
bpf_error("unsupported index operation");
+ 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");
+
+ /*
+ * Load into the X register the offset computed into the
+ * register specified by "index".
+ */
+ s = xfer_to_x(inst);
+
+ /*
+ * Load the item at that offset.
+ */
+ tmp = new_stmt(BPF_LD|BPF_IND|size);
+ sappend(s, tmp);
+ sappend(inst->s, s);
+ break;
+
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
* frame, so that 0 refers, for Ethernet LANE, to
* the beginning of the destination address?
*/
- s = xfer_to_x(index);
+ s = gen_abs_offset_varpart(&off_linkhdr);
+
+ /*
+ * 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 specified
+ * 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);
+
+ /*
+ * 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_linkhdr.constant_part;
sappend(s, tmp);
- sappend(index->s, s);
+ sappend(inst->s, s);
break;
case Q_IP:
case Q_LAT:
case Q_MOPRC:
case Q_MOPDL:
-#ifdef INET6
case Q_IPV6:
-#endif
- /* XXX Note that we assume a fixed link header here. */
- s = xfer_to_x(index);
+ /*
+ * 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_abs_offset_varpart(&off_linkpl);
+
+ /*
+ * If "s" is non-null, it has code to arrange that the
+ * X register contains the variable part of the offset
+ * of the link-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 specified 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);
+
+ /*
+ * 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 link-layer
+ * payload, and the constant part of the offset of the
+ * start of the link-layer payload.
+ */
tmp = new_stmt(BPF_LD|BPF_IND|size);
- tmp->s.k = off_nl;
+ tmp->s.k = off_linkpl.constant_part + off_nl;
sappend(s, tmp);
- sappend(index->s, s);
+ sappend(inst->s, s);
+ /*
+ * Do the computation only if the packet contains
+ * the protocol in question.
+ */
b = gen_proto_abbrev(proto);
- if (index->b)
- gen_and(index->b, b);
- index->b = b;
+ if (inst->b)
+ gen_and(inst->b, b);
+ inst->b = b;
break;
case Q_SCTP:
case Q_IGRP:
case Q_PIM:
case Q_VRRP:
+ case Q_CARP:
+ /*
+ * 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();
- sappend(s, xfer_to_a(index));
+
+ /*
+ * The X register now contains the sum of the variable
+ * part of the offset of the link-layer payload 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 sum of the constant part of
+ * the offset of the link-layer payload and the offset,
+ * relative to the beginning of the link-layer payload,
+ * of the network-layer header.
+ */
+ 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_nl;
- sappend(index->s, s);
+ tmp->s.k = off_linkpl.constant_part + off_nl;
+ sappend(inst->s, s);
+ /*
+ * 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 (index->b)
- gen_and(index->b, b);
-#ifdef INET6
+ if (inst->b)
+ gen_and(inst->b, b);
gen_and(gen_proto_abbrev(Q_IP), b);
-#endif
- index->b = b;
+ inst->b = b;
break;
-#ifdef INET6
case Q_ICMPV6:
bpf_error("IPv6 upper-layer protocol is not supported by proto[x]");
/*NOTREACHED*/
-#endif
}
- index->regno = regno;
+ inst->regno = regno;
s = new_stmt(BPF_ST);
s->s.k = regno;
- sappend(index->s, s);
+ sappend(inst->s, s);
- return index;
+ return inst;
}
struct block *
static int regused[BPF_MEMWORDS];
static int curreg;
+/*
+ * Initialize the table of used registers and the current register.
+ */
+static void
+init_regs()
+{
+ curreg = 0;
+ memset(regused, 0, sizeof regused);
+}
+
/*
* Return the next free register.
*/
}
bpf_error("too many registers needed to evaluate expression");
/* NOTREACHED */
+ return 0;
}
/*
return b;
}
+/*
+ * 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;
abort();
case '=':
- return gen_cmp(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
+ return gen_cmp(OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
case '<':
- b = gen_cmp_lt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
+ b = gen_cmp_lt(OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
return b;
case '>':
- b = gen_cmp_gt(OR_LINK, (u_int)idx, BPF_B, (bpf_int32)val);
+ b = gen_cmp_gt(OR_LINKHDR, (u_int)idx, BPF_B, (bpf_int32)val);
return b;
case '|':
case Q_DEFAULT:
case Q_LINK:
- if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX)
+ switch (linktype) {
+ case DLT_ARCNET:
+ case DLT_ARCNET_LINUX:
return gen_ahostop(abroadcast, Q_DST);
- if (linktype == DLT_EN10MB)
- return gen_ehostop(ebroadcast, Q_DST);
- if (linktype == DLT_FDDI)
+ case DLT_EN10MB:
+ case DLT_NETANALYZER:
+ case DLT_NETANALYZER_TRANSPARENT:
+ b1 = gen_prevlinkhdr_check();
+ b0 = gen_ehostop(ebroadcast, Q_DST);
+ if (b1 != NULL)
+ gen_and(b1, b0);
+ return b0;
+ case DLT_FDDI:
return gen_fhostop(ebroadcast, Q_DST);
- if (linktype == DLT_IEEE802)
+ case DLT_IEEE802:
return gen_thostop(ebroadcast, Q_DST);
- if (linktype == DLT_IEEE802_11)
+ 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);
- if (linktype == DLT_IP_OVER_FC)
+ case DLT_IP_OVER_FC:
return gen_ipfchostop(ebroadcast, Q_DST);
- if (linktype == DLT_SUNATM && 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;
+ default:
+ bpf_error("not a broadcast link");
}
- bpf_error("not a broadcast link");
break;
case Q_IP:
+ /*
+ * We treat a netmask of PCAP_NETMASK_UNKNOWN (0xffffffff)
+ * as an indication that we don't know the netmask, and fail
+ * in that case.
+ */
+ if (netmask == PCAP_NETMASK_UNKNOWN)
+ bpf_error("netmask not known, so 'ip broadcast' not supported");
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,
+ b1 = gen_mcmp(OR_LINKPL, 16, BPF_W, (bpf_int32)0, hostmask);
+ b2 = gen_mcmp(OR_LINKPL, 16, BPF_W,
(bpf_int32)(~0 & hostmask), hostmask);
gen_or(b1, b2);
gen_and(b0, b2);
}
bpf_error("only link-layer/IP broadcast filters supported");
/* NOTREACHED */
+ return NULL;
}
/*
register struct slist *s;
/* link[offset] & 1 != 0 */
- s = gen_load_a(OR_LINK, offset, BPF_B);
+ s = gen_load_a(OR_LINKHDR, offset, BPF_B);
b0 = new_block(JMP(BPF_JSET));
b0->s.k = 1;
b0->stmts = s;
case Q_DEFAULT:
case Q_LINK:
- if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX)
+ switch (linktype) {
+ case DLT_ARCNET:
+ case DLT_ARCNET_LINUX:
/* all ARCnet multicasts use the same address */
return gen_ahostop(abroadcast, Q_DST);
-
- if (linktype == DLT_EN10MB) {
+ case DLT_EN10MB:
+ case DLT_NETANALYZER:
+ case DLT_NETANALYZER_TRANSPARENT:
+ b1 = gen_prevlinkhdr_check();
/* ether[0] & 1 != 0 */
- return gen_mac_multicast(0);
- }
-
- if (linktype == DLT_FDDI) {
+ b0 = gen_mac_multicast(0);
+ if (b1 != NULL)
+ gen_and(b1, b0);
+ return b0;
+ case DLT_FDDI:
/*
* XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX
*
*/
/* fddi[1] & 1 != 0 */
return gen_mac_multicast(1);
- }
-
- if (linktype == DLT_IEEE802) {
+ case DLT_IEEE802:
/* tr[2] & 1 != 0 */
return gen_mac_multicast(2);
- }
-
- if (linktype == DLT_IEEE802_11) {
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ case DLT_PPI:
/*
* Oh, yuk.
*
*
* First, check for To DS set, i.e. "link[1] & 0x01".
*/
- s = gen_load_a(OR_LINK, 1, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 1, BPF_B);
b1 = new_block(JMP(BPF_JSET));
b1->s.k = 0x01; /* To DS */
b1->stmts = s;
* Now, check for To DS not set, i.e. check
* "!(link[1] & 0x01)".
*/
- s = gen_load_a(OR_LINK, 1, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 1, BPF_B);
b2 = new_block(JMP(BPF_JSET));
b2->s.k = 0x01; /* To DS */
b2->stmts = s;
* Now check for a data frame.
* I.e, check "link[0] & 0x08".
*/
- s = gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b1 = new_block(JMP(BPF_JSET));
b1->s.k = 0x08;
b1->stmts = s;
* is a management frame.
* I.e, check "!(link[0] & 0x08)".
*/
- s = gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b2 = new_block(JMP(BPF_JSET));
b2->s.k = 0x08;
b2->stmts = s;
*
* I.e., check "!(link[0] & 0x04)".
*/
- s = gen_load_a(OR_LINK, 0, BPF_B);
+ s = gen_load_a(OR_LINKHDR, 0, BPF_B);
b1 = new_block(JMP(BPF_JSET));
b1->s.k = 0x04;
b1->stmts = s;
*/
gen_and(b1, b0);
return b0;
- }
-
- if (linktype == DLT_IP_OVER_FC) {
+ case DLT_IP_OVER_FC:
b0 = gen_mac_multicast(2);
return b0;
+ default:
+ break;
}
-
- if (linktype == DLT_SUNATM && 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;
- }
-
/* Link not known to support multicasts */
break;
case Q_IP:
b0 = gen_linktype(ETHERTYPE_IP);
- b1 = gen_cmp_ge(OR_NET, 16, BPF_B, (bpf_int32)224);
+ b1 = gen_cmp_ge(OR_LINKPL, 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);
+ b1 = gen_cmp(OR_LINKPL, 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".
+ * Filter on inbound (dir == 0) or outbound (dir == 1) traffic.
+ * Outbound traffic is sent by this machine, while inbound traffic is
+ * sent by a remote machine (and may include packets destined for a
+ * unicast or multicast link-layer address we are not subscribing to).
+ * These are the same definitions implemented by pcap_setdirection().
+ * Capturing only unicast traffic destined for this host is probably
+ * better accomplished using a higher-layer filter.
*/
struct block *
gen_inbound(dir)
dir);
break;
- case DLT_LINUX_SLL:
+ case DLT_IPNET:
if (dir) {
- /*
- * Match packets sent by this machine.
- */
- b0 = gen_cmp(OR_LINK, 0, BPF_H, LINUX_SLL_OUTGOING);
+ /* match outgoing packets */
+ b0 = gen_cmp(OR_LINKHDR, 2, BPF_H, IPNET_OUTBOUND);
} else {
- /*
- * 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);
+ /* match incoming packets */
+ b0 = gen_cmp(OR_LINKHDR, 2, BPF_H, IPNET_INBOUND);
+ }
+ break;
+
+ case DLT_LINUX_SLL:
+ /* match outgoing packets */
+ b0 = gen_cmp(OR_LINKHDR, 0, BPF_H, LINUX_SLL_OUTGOING);
+ if (!dir) {
+ /* to filter on inbound traffic, invert the match */
+ gen_not(b0);
}
break;
+#ifdef HAVE_NET_PFVAR_H
case DLT_PFLOG:
- b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, dir), BPF_B,
+ b0 = gen_cmp(OR_LINKHDR, offsetof(struct pfloghdr, dir), BPF_B,
(bpf_int32)((dir == 0) ? PF_IN : PF_OUT));
break;
+#endif
case DLT_PPP_PPPD:
if (dir) {
/* match outgoing packets */
- b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_OUT);
+ b0 = gen_cmp(OR_LINKHDR, 0, BPF_B, PPP_PPPD_OUT);
} else {
/* match incoming packets */
- b0 = gen_cmp(OR_LINK, 0, BPF_B, PPP_PPPD_IN);
+ b0 = gen_cmp(OR_LINKHDR, 0, BPF_B, PPP_PPPD_IN);
}
break;
+ 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:
+ case DLT_JUNIPER_VS:
+ case DLT_JUNIPER_SRX_E2E:
+ case DLT_JUNIPER_FIBRECHANNEL:
+ case DLT_JUNIPER_ATM_CEMIC:
+
/* 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);
+ b0 = gen_mcmp(OR_LINKHDR, 3, BPF_B, 0, 0x01);
} else {
/* match incoming packets */
- b0 = gen_mcmp(OR_LINK, 3, BPF_B, 1, 0x01);
+ b0 = gen_mcmp(OR_LINKHDR, 3, BPF_B, 1, 0x01);
}
- break;
+ break;
default:
+ /*
+ * If we have packet meta-data indicating a direction,
+ * check it, otherwise give up as this link-layer type
+ * has nothing in the packet data.
+ */
+#if defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER)
+ /*
+ * This is Linux with PF_PACKET support.
+ * If this is a *live* capture, we can look at
+ * special meta-data in the filter expression;
+ * if it's a savefile, we can't.
+ */
+ if (bpf_pcap->rfile != NULL) {
+ /* We have a FILE *, so this is a savefile */
+ bpf_error("inbound/outbound not supported on linktype %d when reading savefiles",
+ linktype);
+ b0 = NULL;
+ /* NOTREACHED */
+ }
+ /* match outgoing packets */
+ b0 = gen_cmp(OR_LINKHDR, SKF_AD_OFF + SKF_AD_PKTTYPE, BPF_H,
+ PACKET_OUTGOING);
+ if (!dir) {
+ /* to filter on inbound traffic, invert the match */
+ gen_not(b0);
+ }
+#else /* defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) */
bpf_error("inbound/outbound not supported on linktype %d",
linktype);
b0 = NULL;
/* NOTREACHED */
+#endif /* defined(linux) && defined(PF_PACKET) && defined(SO_ATTACH_FILTER) */
}
return (b0);
}
+#ifdef HAVE_NET_PFVAR_H
/* PF firewall log matched interface */
struct block *
gen_pf_ifname(const char *ifname)
struct block *b0;
u_int len, off;
- if (linktype == DLT_PFLOG) {
- len = sizeof(((struct pfloghdr *)0)->ifname);
- off = offsetof(struct pfloghdr, ifname);
- } else {
- bpf_error("ifname not supported on linktype 0x%x", linktype);
+ 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);
+ b0 = gen_bcmp(OR_LINKHDR, off, strlen(ifname), (const u_char *)ifname);
return (b0);
}
-/* PF firewall log matched interface */
+/* PF firewall log ruleset name */
struct block *
gen_pf_ruleset(char *ruleset)
{
struct block *b0;
if (linktype != DLT_PFLOG) {
- bpf_error("ruleset not supported on linktype 0x%x", linktype);
+ bpf_error("ruleset supported only on PF linktype");
/* NOTREACHED */
}
+
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);
+
+ b0 = gen_bcmp(OR_LINKHDR, offsetof(struct pfloghdr, ruleset),
+ strlen(ruleset), (const u_char *)ruleset);
+ return (b0);
+}
+
+/* PF firewall log rule number */
+struct block *
+gen_pf_rnr(int rnr)
+{
+ struct block *b0;
+
+ if (linktype != DLT_PFLOG) {
+ bpf_error("rnr supported only on PF linktype");
+ /* NOTREACHED */
+ }
+
+ b0 = gen_cmp(OR_LINKHDR, offsetof(struct pfloghdr, rulenr), BPF_W,
+ (bpf_int32)rnr);
+ return (b0);
+}
+
+/* PF firewall log sub-rule number */
+struct block *
+gen_pf_srnr(int srnr)
+{
+ struct block *b0;
+
+ if (linktype != DLT_PFLOG) {
+ bpf_error("srnr supported only on PF linktype");
+ /* NOTREACHED */
+ }
+
+ b0 = gen_cmp(OR_LINKHDR, offsetof(struct pfloghdr, subrulenr), BPF_W,
+ (bpf_int32)srnr);
return (b0);
}
-/* PF firewall log rule number */
+/* PF firewall log reason code */
struct block *
-gen_pf_rnr(int rnr)
+gen_pf_reason(int reason)
{
struct block *b0;
- if (linktype == DLT_PFLOG) {
- b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, rulenr), BPF_W,
- (bpf_int32)rnr);
- } else {
- bpf_error("rnr not supported on linktype 0x%x", linktype);
+ if (linktype != DLT_PFLOG) {
+ bpf_error("reason supported only on PF linktype");
/* NOTREACHED */
}
+ b0 = gen_cmp(OR_LINKHDR, offsetof(struct pfloghdr, reason), BPF_B,
+ (bpf_int32)reason);
return (b0);
}
-/* PF firewall log sub-rule number */
+/* PF firewall log action */
struct block *
-gen_pf_srnr(int srnr)
+gen_pf_action(int action)
{
struct block *b0;
if (linktype != DLT_PFLOG) {
- bpf_error("srnr not supported on linktype 0x%x", linktype);
+ bpf_error("action supported only on PF linktype");
/* NOTREACHED */
}
- b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, subrulenr), BPF_W,
- (bpf_int32)srnr);
+ b0 = gen_cmp(OR_LINKHDR, 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);
+}
+
+struct block *
+gen_pf_ruleset(char *ruleset)
+{
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
+}
+
+struct block *
+gen_pf_rnr(int rnr)
+{
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
+}
+
+struct block *
+gen_pf_srnr(int srnr)
+{
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
+}
-/* PF firewall log reason code */
struct block *
gen_pf_reason(int reason)
+{
+ bpf_error("libpcap was compiled on a machine without pf support");
+ /* NOTREACHED */
+ return (NULL);
+}
+
+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 */
+
+/* IEEE 802.11 wireless header */
+struct block *
+gen_p80211_type(int type, int mask)
{
struct block *b0;
- if (linktype == DLT_PFLOG) {
- b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, reason), BPF_B,
- (bpf_int32)reason);
- } else {
- bpf_error("reason not supported on linktype 0x%x", linktype);
+ switch (linktype) {
+
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ b0 = gen_mcmp(OR_LINKHDR, 0, BPF_B, (bpf_int32)type,
+ (bpf_int32)mask);
+ break;
+
+ default:
+ bpf_error("802.11 link-layer types supported only on 802.11");
/* NOTREACHED */
}
return (b0);
}
-/* PF firewall log action */
struct block *
-gen_pf_action(int action)
+gen_p80211_fcdir(int fcdir)
{
struct block *b0;
- if (linktype == DLT_PFLOG) {
- b0 = gen_cmp(OR_LINK, offsetof(struct pfloghdr, action), BPF_B,
- (bpf_int32)action);
- } else {
- bpf_error("action not supported on linktype 0x%x", linktype);
+ switch (linktype) {
+
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ break;
+
+ default:
+ bpf_error("frame direction supported only with 802.11 headers");
/* NOTREACHED */
}
+ b0 = gen_mcmp(OR_LINKHDR, 1, BPF_B, (bpf_int32)fcdir,
+ (bpf_u_int32)IEEE80211_FC1_DIR_MASK);
+
return (b0);
}
register const u_char *eaddr;
struct qual q;
{
- if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
- if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX)
- return gen_ahostop(eaddr, (int)q.dir);
+ switch (linktype) {
+
+ 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;
+
+ default:
+ bpf_error("aid supported only on ARCnet");
+ /* NOTREACHED */
}
bpf_error("ARCnet address used in non-arc expression");
/* NOTREACHED */
+ return NULL;
}
static struct block *
switch (dir) {
/* src comes first, different from Ethernet */
case Q_SRC:
- return gen_bcmp(OR_LINK, 0, 1, eaddr);
+ return gen_bcmp(OR_LINKHDR, 0, 1, eaddr);
case Q_DST:
- return gen_bcmp(OR_LINK, 1, 1, eaddr);
+ return gen_bcmp(OR_LINKHDR, 1, 1, eaddr);
case Q_AND:
b0 = gen_ahostop(eaddr, Q_SRC);
b1 = gen_ahostop(eaddr, Q_DST);
gen_or(b0, b1);
return b1;
+
+ case Q_ADDR1:
+ bpf_error("'addr1' is only supported on 802.11");
+ break;
+
+ case Q_ADDR2:
+ bpf_error("'addr2' is only supported on 802.11");
+ break;
+
+ case Q_ADDR3:
+ bpf_error("'addr3' is only supported on 802.11");
+ break;
+
+ case Q_ADDR4:
+ bpf_error("'addr4' is only supported on 802.11");
+ break;
+
+ case Q_RA:
+ bpf_error("'ra' is only supported on 802.11");
+ break;
+
+ case Q_TA:
+ bpf_error("'ta' is only supported on 802.11");
+ break;
}
abort();
/* NOTREACHED */
}
+#if defined(SKF_AD_VLAN_TAG) && defined(SKF_AD_VLAN_TAG_PRESENT)
+static struct block *
+gen_vlan_bpf_extensions(int vlan_num)
+{
+ struct block *b0, *b1;
+ struct slist *s;
+
+ /* generate new filter code based on extracting packet
+ * metadata */
+ s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
+ s->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT;
+
+ b0 = new_block(JMP(BPF_JEQ));
+ b0->stmts = s;
+ b0->s.k = 1;
+
+ if (vlan_num >= 0) {
+ s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
+ s->s.k = SKF_AD_OFF + SKF_AD_VLAN_TAG;
+
+ b1 = new_block(JMP(BPF_JEQ));
+ b1->stmts = s;
+ b1->s.k = (bpf_int32) vlan_num;
+
+ gen_and(b0,b1);
+ b0 = b1;
+ }
+
+ return b0;
+}
+#endif
+
+static struct block *
+gen_vlan_no_bpf_extensions(int vlan_num)
+{
+ struct block *b0, *b1;
+
+ /* check for VLAN, including QinQ */
+ b0 = gen_linktype(ETHERTYPE_8021Q);
+ b1 = gen_linktype(ETHERTYPE_8021QINQ);
+ gen_or(b0,b1);
+ b0 = b1;
+
+ /* If a specific VLAN is requested, check VLAN id */
+ if (vlan_num >= 0) {
+ b1 = gen_mcmp(OR_LINKPL, 0, BPF_H,
+ (bpf_int32)vlan_num, 0x0fff);
+ gen_and(b0, b1);
+ b0 = b1;
+ }
+
+ /*
+ * The payload follows the full header, including the
+ * VLAN tags, so skip past this VLAN tag.
+ */
+ off_linkpl.constant_part += 4;
+
+ /*
+ * The link-layer type information follows the VLAN tags, so
+ * skip past this VLAN tag.
+ */
+ off_linktype.constant_part += 4;
+
+ return b0;
+}
+
/*
* support IEEE 802.1Q VLAN trunk over ethernet
*/
{
struct block *b0;
+ /* can't check for VLAN-encapsulated packets inside MPLS */
+ if (label_stack_depth > 0)
+ bpf_error("no VLAN match after MPLS");
+
/*
- * 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.
+ * 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
* be done assuming a VLAN, even though the "or" could be viewed
* as meaning "or, if this isn't a VLAN packet...".
*/
- orig_linktype = off_linktype; /* save original values */
- orig_nl = off_nl;
-
- switch (linktype) {
+ switch (linktype) {
- case DLT_EN10MB:
- off_linktype += 4;
- off_nl_nosnap += 4;
- off_nl += 4;
+ case DLT_EN10MB:
+ case DLT_NETANALYZER:
+ case DLT_NETANALYZER_TRANSPARENT:
+#if defined(SKF_AD_VLAN_TAG) && defined(SKF_AD_VLAN_TAG_PRESENT)
+ /* Verify that this is the outer part of the packet and
+ * not encapsulated somehow. */
+ if (vlan_stack_depth == 0 && !off_linkhdr.is_variable &&
+ off_linkhdr.constant_part ==
+ off_outermostlinkhdr.constant_part) {
+ /*
+ * Do we need special VLAN handling?
+ */
+ if (bpf_pcap->bpf_codegen_flags & BPF_SPECIAL_VLAN_HANDLING)
+ b0 = gen_vlan_bpf_extensions(vlan_num);
+ else
+ b0 = gen_vlan_no_bpf_extensions(vlan_num);
+ } else
+#endif
+ b0 = gen_vlan_no_bpf_extensions(vlan_num);
break;
- default:
- bpf_error("no VLAN support for data link type %d",
- linktype);
- /*NOTREACHED*/
- }
-
- /* check for VLAN */
- b0 = gen_cmp(OR_LINK, orig_linktype, BPF_H, (bpf_int32)ETHERTYPE_8021Q);
-
- /* If a specific VLAN is requested, check VLAN id */
- if (vlan_num >= 0) {
- struct block *b1;
+ case DLT_IEEE802_11:
+ case DLT_PRISM_HEADER:
+ case DLT_IEEE802_11_RADIO_AVS:
+ case DLT_IEEE802_11_RADIO:
+ b0 = gen_vlan_no_bpf_extensions(vlan_num);
+ break;
- b1 = gen_mcmp(OR_LINK, orig_nl, BPF_H, (bpf_int32)vlan_num,
- 0x0fff);
- gen_and(b0, b1);
- b0 = b1;
+ default:
+ bpf_error("no VLAN support for data link type %d",
+ linktype);
+ /*NOTREACHED*/
}
+ vlan_stack_depth++;
+
return (b0);
}
gen_mpls(label_num)
int label_num;
{
- struct block *b0;
-
- /*
- * 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_linktype = off_linktype; /* save original values */
- orig_nl = off_nl;
-
- switch (linktype) {
-
- case DLT_C_HDLC: /* fall through */
- case DLT_EN10MB:
- off_linktype += 4;
- off_nl_nosnap += 4;
- off_nl += 4;
-
- b0 = gen_cmp(OR_LINK, orig_linktype, BPF_H,
- (bpf_int32)ETHERTYPE_MPLS);
- break;
-
- case DLT_PPP:
- off_linktype += 4;
- off_nl_nosnap += 4;
- off_nl += 4;
-
- b0 = gen_cmp(OR_LINK, orig_linktype, BPF_H,
- (bpf_int32)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",
+ struct block *b0, *b1;
+
+ if (label_stack_depth > 0) {
+ /* just match the bottom-of-stack bit clear */
+ b0 = gen_mcmp(OR_PREVMPLSHDR, 2, BPF_B, 0, 0x01);
+ } else {
+ /*
+ * We're not in an MPLS stack yet, so check the link-layer
+ * type against MPLS.
+ */
+ switch (linktype) {
+
+ case DLT_C_HDLC: /* fall through */
+ case DLT_EN10MB:
+ case DLT_NETANALYZER:
+ case DLT_NETANALYZER_TRANSPARENT:
+ 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;
+ b0 = NULL;
+ /*NOTREACHED*/
+ break;
+ }
}
/* If a specific MPLS label is requested, check it */
if (label_num >= 0) {
- struct block *b1;
-
label_num = label_num << 12; /* label is shifted 12 bits on the wire */
- b1 = gen_mcmp(OR_LINK, orig_nl, BPF_W, (bpf_int32)label_num,
+ b1 = gen_mcmp(OR_LINKPL, 0, BPF_W, (bpf_int32)label_num,
0xfffff000); /* only compare the first 20 bits */
gen_and(b0, b1);
b0 = b1;
}
+ /*
+ * 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.
+ *
+ * Increment the MPLS stack depth as well; this indicates 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.
+ *
+ * XXX - this is a bit of a kludge. See comments in gen_vlan().
+ */
+ off_nl_nosnap += 4;
+ off_nl += 4;
+ label_stack_depth++;
return (b0);
}
+/*
+ * Support PPPOE discovery and session.
+ */
+struct block *
+gen_pppoed()
+{
+ /* check for PPPoE discovery */
+ return gen_linktype((bpf_int32)ETHERTYPE_PPPOED);
+}
+
+struct block *
+gen_pppoes(sess_num)
+ int sess_num;
+{
+ struct block *b0, *b1;
+
+ /*
+ * Test against the PPPoE session link-layer type.
+ */
+ b0 = gen_linktype((bpf_int32)ETHERTYPE_PPPOES);
+
+ /* If a specific session is requested, check PPPoE session id */
+ if (sess_num >= 0) {
+ b1 = gen_mcmp(OR_LINKPL, 0, BPF_W,
+ (bpf_int32)sess_num, 0x0000ffff);
+ gen_and(b0, b1);
+ b0 = b1;
+ }
+
+ /*
+ * 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...".
+ *
+ * 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.
+ */
+ PUSH_LINKHDR(DLT_PPP, off_linkpl.is_variable,
+ off_linkpl.constant_part + off_nl + 6, /* 6 bytes past the PPPoE header */
+ off_linkpl.reg);
+
+ off_linktype = off_linkhdr;
+ off_linkpl.constant_part = off_linkhdr.constant_part + 2;
+
+ off_nl = 0;
+ off_nl_nosnap = 0; /* no 802.2 LLC */
+
+ return b0;
+}
+
struct block *
gen_atmfield_code(atmfield, jvalue, jtype, reverse)
int atmfield;
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,
+ b0 = gen_ncmp(OR_LINKHDR, off_vpi, BPF_B, 0xffffffff, jtype,
reverse, jvalue);
break;
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,
+ b0 = gen_ncmp(OR_LINKHDR, 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,
+ b0 = gen_ncmp(OR_LINKHDR, 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,
+ b0 = gen_ncmp(OR_LINKHDR, off_payload + MSG_TYPE_POS, BPF_B,
0xffffffff, jtype, reverse, jvalue);
break;
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,
+ b0 = gen_ncmp(OR_LINKHDR, off_proto, BPF_B, 0xffffffff,
jtype, reverse, jvalue);
break;
* 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".
+ * We assume LANE means Ethernet, not Token Ring.
*/
- is_lane = 1;
- off_mac = off_payload + 2; /* MAC header */
- off_linktype = off_mac + 12;
- off_nl = off_mac + 14; /* Ethernet II */
- off_nl_nosnap = off_mac + 17; /* 802.3+802.2 */
+ PUSH_LINKHDR(DLT_EN10MB, 0,
+ off_payload + 2, /* Ethernet header */
+ -1);
+ off_linktype.constant_part = off_linkhdr.constant_part + 12;
+ off_linkpl.constant_part = off_linkhdr.constant_part + 14; /* Ethernet */
+ off_nl = 0; /* Ethernet II */
+ off_nl_nosnap = 3; /* 802.3+802.2 */
break;
case A_LLC:
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;
+ linktype = prevlinktype;
break;
default:
return b1;
}
+/*
+ * Filtering for MTP2 messages based on li value
+ * FISU, length is null
+ * LSSU, length is 1 or 2
+ * MSU, length is 3 or more
+ * For MTP2_HSL, sequences are on 2 bytes, and length on 9 bits
+ */
+struct block *
+gen_mtp2type_abbrev(type)
+ int type;
+{
+ struct block *b0, *b1;
+
+ switch (type) {
+
+ 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 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 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;
+
+ case MH_FISU:
+ if ( (linktype != DLT_MTP2) &&
+ (linktype != DLT_ERF) &&
+ (linktype != DLT_MTP2_WITH_PHDR) )
+ bpf_error("'hfisu' supported only on MTP2_HSL");
+ /* gen_ncmp(offrel, offset, size, mask, jtype, reverse, value) */
+ b0 = gen_ncmp(OR_PACKET, off_li_hsl, BPF_H, 0xff80, BPF_JEQ, 0, 0);
+ break;
+
+ case MH_LSSU:
+ if ( (linktype != DLT_MTP2) &&
+ (linktype != DLT_ERF) &&
+ (linktype != DLT_MTP2_WITH_PHDR) )
+ bpf_error("'hlssu' supported only on MTP2_HSL");
+ b0 = gen_ncmp(OR_PACKET, off_li_hsl, BPF_H, 0xff80, BPF_JGT, 1, 0x0100);
+ b1 = gen_ncmp(OR_PACKET, off_li_hsl, BPF_H, 0xff80, BPF_JGT, 0, 0);
+ gen_and(b1, b0);
+ break;
+
+ case MH_MSU:
+ if ( (linktype != DLT_MTP2) &&
+ (linktype != DLT_ERF) &&
+ (linktype != DLT_MTP2_WITH_PHDR) )
+ bpf_error("'hmsu' supported only on MTP2_HSL");
+ b0 = gen_ncmp(OR_PACKET, off_li_hsl, BPF_H, 0xff80, BPF_JGT, 0, 0x0100);
+ break;
+
+ default:
+ abort();
+ }
+ return b0;
+}
+
+struct block *
+gen_mtp3field_code(mtp3field, jvalue, jtype, reverse)
+ int mtp3field;
+ bpf_u_int32 jvalue;
+ bpf_u_int32 jtype;
+ int reverse;
+{
+ struct block *b0;
+ bpf_u_int32 val1 , val2 , val3;
+ u_int newoff_sio=off_sio;
+ u_int newoff_opc=off_opc;
+ u_int newoff_dpc=off_dpc;
+ u_int newoff_sls=off_sls;
+
+ switch (mtp3field) {
+
+ case MH_SIO:
+ newoff_sio += 3; /* offset for MTP2_HSL */
+ /* FALLTHROUGH */
+
+ 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, newoff_sio, BPF_B, 0xffffffff,
+ (u_int)jtype, reverse, (u_int)jvalue);
+ break;
+
+ case MH_OPC:
+ newoff_opc+=3;
+ 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, newoff_opc, BPF_W, 0x00c0ff0f,
+ (u_int)jtype, reverse, (u_int)jvalue);
+ break;
+
+ case MH_DPC:
+ newoff_dpc += 3;
+ /* FALLTHROUGH */
+
+ 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, newoff_dpc, BPF_W, 0xff3f0000,
+ (u_int)jtype, reverse, (u_int)jvalue);
+ break;
+
+ case MH_SLS:
+ newoff_sls+=3;
+ 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, newoff_sls, BPF_B, 0xf0,
+ (u_int)jtype,reverse, (u_int)jvalue);
+ break;
+
+ default:
+ abort();
+ }
+ return b0;
+}
static struct block *
gen_msg_abbrev(type)
projects / libpcap / blobdiff