X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/64c7184aa634eaf11933c7c11acce258117885c9..af30d75a3ece28ef91c77bc1fc3ef658cb8aa69b:/gencode.c diff --git a/gencode.c b/gencode.c index 4b19e0e9..ea844903 100644 --- a/gencode.c +++ b/gencode.c @@ -21,7 +21,7 @@ */ #ifndef lint static const char rcsid[] = - "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.116 2000-08-06 01:22:39 torsten Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.129 2000-10-28 09:30:21 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H @@ -40,9 +40,9 @@ struct rtentry; #include #include -#include #include +#include #include #include #include @@ -50,6 +50,7 @@ struct rtentry; #include "pcap-int.h" #include "ethertype.h" +#include "nlpid.h" #include "gencode.h" #include "ppp.h" #include @@ -58,6 +59,10 @@ struct rtentry; #include #endif /*INET6*/ +#define LLC_ISO_LSAP 0xfe + +#define ETHERMTU 1500 + #ifdef HAVE_OS_PROTO_H #include "os-proto.h" #endif @@ -124,12 +129,14 @@ static inline void syntax(void); static void backpatch(struct block *, struct block *); static void merge(struct block *, struct block *); static struct block *gen_cmp(u_int, u_int, bpf_int32); +static struct block *gen_cmp_gt(u_int, u_int, bpf_int32); static struct block *gen_mcmp(u_int, u_int, bpf_int32, bpf_u_int32); static struct block *gen_bcmp(u_int, u_int, const u_char *); static struct block *gen_uncond(int); static inline struct block *gen_true(void); static inline struct block *gen_false(void); static struct block *gen_linktype(int); +static struct block *gen_snap(bpf_u_int32, bpf_u_int32, u_int); static struct block *gen_hostop(bpf_u_int32, bpf_u_int32, int, int, u_int, u_int); #ifdef INET6 static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int, u_int, u_int); @@ -157,6 +164,7 @@ struct block *gen_portop6(int, int, int); static struct block *gen_port6(int, int, int); #endif static int lookup_proto(const char *, int); +static struct block *gen_protochain(int, int, int); static struct block *gen_proto(int, int, int); static struct slist *xfer_to_x(struct arth *); static struct slist *xfer_to_a(struct arth *); @@ -318,6 +326,7 @@ pcap_compile(pcap_t *p, struct bpf_program *program, program->bf_insns = icode_to_fcode(root, &len); program->bf_len = len; + lex_cleanup(); freechunks(); return (0); } @@ -370,6 +379,20 @@ pcap_compile_nopcap(int snaplen_arg, int linktype_arg, return (0); } +/* + * Clean up a "struct bpf_program" by freeing all the memory allocated + * in it. + */ +void +pcap_freecode(struct bpf_program *program) +{ + program->bf_len = 0; + if (program->bf_insns != NULL) { + free((char *)program->bf_insns); + program->bf_insns = NULL; + } +} + /* * Backpatch the blocks in 'list' to 'target'. The 'sense' field indicates * which of the jt and jf fields has been resolved and which is a pointer @@ -470,6 +493,24 @@ gen_cmp(offset, size, v) return b; } +static struct block * +gen_cmp_gt(offset, size, v) + u_int offset, size; + bpf_int32 v; +{ + struct slist *s; + struct block *b; + + s = new_stmt(BPF_LD|BPF_ABS|size); + s->s.k = offset; + + b = new_block(JMP(BPF_JGT)); + b->stmts = s; + b->s.k = v; + + return b; +} + static struct block * gen_mcmp(offset, size, v, mask) u_int offset, size; @@ -569,7 +610,8 @@ init_linktype(type) return; case DLT_PPP: - case DLT_CHDLC: + case DLT_C_HDLC: + case DLT_PPP_SERIAL: off_linktype = 2; off_nl = 4; return; @@ -637,6 +679,11 @@ init_linktype(type) off_linktype = -1; off_nl = 0; return; + + case DLT_ATM_CLIP: /* Linux ATM defines this */ + off_linktype = 6; + off_nl = 8; + return; } bpf_error("unknown data link type 0x%x", linktype); /* NOTREACHED */ @@ -681,19 +728,108 @@ gen_linktype(proto) switch (linktype) { + case DLT_EN10MB: + /* + * XXX - handle other LLC-encapsulated protocols here + * (IPX, OSI)? + */ + switch (proto) { + + case LLC_ISO_LSAP: + /* + * OSI protocols always use 802.2 encapsulation. + */ + b0 = gen_cmp_gt(off_linktype, BPF_H, ETHERMTU); + gen_not(b0); + b1 = gen_cmp(off_linktype + 2, BPF_H, (long) + ((LLC_ISO_LSAP << 8) | LLC_ISO_LSAP)); + gen_and(b0, b1); + return b1; + + case ETHERTYPE_ATALK: + case ETHERTYPE_AARP: + /* + * EtherTalk (AppleTalk protocols on Ethernet link + * layer) may use 802.2 encapsulation. + */ + + /* + * Check for 802.2 encapsulation (EtherTalk phase 2?); + * we check for an Ethernet type field less than + * 1500, which means it's an 802.3 length field. + */ + b0 = gen_cmp_gt(off_linktype, BPF_H, ETHERMTU); + gen_not(b0); + + /* + * 802.2-encapsulated ETHERTYPE_ATALK packets are + * SNAP packets with an organization code of + * 0x080007 (Apple, for Appletalk) and a protocol + * type of ETHERTYPE_ATALK (Appletalk). + * + * 802.2-encapsulated ETHERTYPE_AARP packets are + * SNAP packets with an organization code of + * 0x000000 (encapsulated Ethernet) and a protocol + * type of ETHERTYPE_AARP (Appletalk ARP). + */ + if (proto == ETHERTYPE_ATALK) + b1 = gen_snap(0x080007, ETHERTYPE_ATALK, 14); + else /* proto == ETHERTYPE_AARP */ + b1 = gen_snap(0x000000, ETHERTYPE_AARP, 14); + gen_and(b0, b1); + + /* + * Check for Ethernet encapsulation (Ethertalk + * phase 1?); we just check for the Ethernet + * protocol type. + */ + b0 = gen_cmp(off_linktype, BPF_H, (bpf_int32)proto); + + gen_or(b0, b1); + return b1; + } + break; + case DLT_SLIP: return gen_false(); case DLT_PPP: - if (proto == ETHERTYPE_IP) + case DLT_PPP_SERIAL: + /* + * We use Ethernet protocol types inside libpcap; + * map them to the corresponding PPP protocol types. + */ + switch (proto) { + + case ETHERTYPE_IP: proto = PPP_IP; /* XXX was 0x21 */ + break; + #ifdef INET6 - else if (proto == ETHERTYPE_IPV6) + case ETHERTYPE_IPV6: proto = PPP_IPV6; + break; #endif + + case ETHERTYPE_DN: + proto = PPP_DECNET; + break; + + case ETHERTYPE_ATALK: + proto = PPP_APPLE; + break; + + case ETHERTYPE_NS: + proto = PPP_NS; + break; + } break; case DLT_PPP_BSDOS: + /* + * We use Ethernet protocol types inside libpcap; + * map them to the corresponding PPP protocol types. + */ switch (proto) { case ETHERTYPE_IP: @@ -739,6 +875,32 @@ gen_linktype(proto) return gen_cmp(off_linktype, BPF_H, (bpf_int32)proto); } +/* + * Check for an LLC SNAP packet with a given organization code and + * protocol type; we check the entire contents of the 802.2 LLC and + * snap headers, checking for a DSAP of 0xAA, an SSAP of 0xAA, 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; +{ + u_char snapblock[8]; + + snapblock[0] = 0xAA; /* DSAP = SNAP */ + snapblock[1] = 0xAA; /* 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(offset, 8, snapblock); +} + static struct block * gen_hostop(addr, mask, dir, proto, src_off, dst_off) bpf_u_int32 addr; @@ -997,6 +1159,9 @@ gen_dnhostop(addr, dir, base_off) gen_or(b0, b1); return b1; + case Q_ISO: + bpf_error("ISO host filtering not implemented"); + default: abort(); } @@ -1084,6 +1249,9 @@ gen_host(addr, mask, proto, dir) case Q_ATALK: bpf_error("ATALK host filtering not implemented"); + case Q_AARP: + bpf_error("AARP host filtering not implemented"); + case Q_DECNET: return gen_dnhostop(addr, dir, off_nl); @@ -1162,6 +1330,9 @@ gen_host6(addr, mask, proto, dir) case Q_ATALK: bpf_error("ATALK host filtering not implemented"); + case Q_AARP: + bpf_error("AARP host filtering not implemented"); + case Q_DECNET: bpf_error("'decnet' modifier applied to ip6 host"); @@ -1317,6 +1488,10 @@ gen_proto_abbrev(proto) b1 = gen_linktype(ETHERTYPE_ATALK); break; + case Q_AARP: + b1 = gen_linktype(ETHERTYPE_AARP); + break; + case Q_DECNET: b1 = gen_linktype(ETHERTYPE_DN); break; @@ -1372,6 +1547,18 @@ gen_proto_abbrev(proto) #endif break; + case Q_ISO: + b1 = gen_linktype(LLC_ISO_LSAP); + break; + + case Q_ESIS: + b1 = gen_proto(ISO9542_ESIS, Q_ISO, Q_DEFAULT); + break; + + case Q_ISIS: + b1 = gen_proto(ISO10589_ISIS, Q_ISO, Q_DEFAULT); + break; + default: abort(); } @@ -1608,7 +1795,7 @@ gen_joinsp(s, n) } #endif -struct block * +static struct block * gen_protochain(v, proto, dir) int v; int proto; @@ -1943,6 +2130,12 @@ gen_proto(v, proto, dir) gen_and(b0, b1); return b1; + case Q_ISO: + b0 = gen_linktype(LLC_ISO_LSAP); + b1 = gen_cmp(off_nl + 3, BPF_B, (long)v); + gen_and(b0, b1); + return b1; + case Q_ARP: bpf_error("arp does not encapsulate another protocol"); /* NOTREACHED */ @@ -2758,6 +2951,9 @@ gen_greater(n) return gen_len(BPF_JGE, n); } +/* + * Actually, this is less than or equal. + */ struct block * gen_less(n) int n; @@ -2918,3 +3114,50 @@ gen_inbound(dir) dir); return (b0); } + +/* + * support IEEE 802.1Q VLAN trunk over ethernet + */ +struct block * +gen_vlan(vlan_num) + int vlan_num; +{ + static u_int orig_linktype = -1, orig_nl = -1; + struct block *b0; + + /* + * Change the offsets to point to the type and data fields within + * the VLAN packet. This is somewhat of a kludge. + */ + if (orig_nl == (u_int)-1) { + orig_linktype = off_linktype; /* save original values */ + orig_nl = off_nl; + + switch (linktype) { + + case DLT_EN10MB: + off_linktype = 16; + off_nl = 18; + break; + + default: + bpf_error("no VLAN support for data link type %d", + linktype); + /*NOTREACHED*/ + } + } + + /* check for VLAN */ + b0 = gen_cmp(orig_linktype, BPF_H, (bpf_int32)ETHERTYPE_8021Q); + + /* If a specific VLAN is requested, check VLAN id */ + if (vlan_num >= 0) { + struct block *b1; + + b1 = gen_cmp(orig_nl, BPF_H, (bpf_int32)vlan_num); + gen_and(b0, b1); + b0 = b1; + } + + return (b0); +}