X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/98b22a19e0c3529cc10b0c613215acdb4d7471ac..bc6f4cb8a61b5c60a8027b34b5e680977ab6ac4a:/gencode.c diff --git a/gencode.c b/gencode.c index aa429072..81da02ef 100644 --- a/gencode.c +++ b/gencode.c @@ -21,7 +21,7 @@ */ #ifndef lint static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.13 2005-05-01 09:05:30 guy Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.41 2006-09-13 07:02:15 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H @@ -100,8 +100,8 @@ static const char rcsid[] _U_ = 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 updating VLAN, MPLS, and PPPoE offsets. */ +static u_int orig_linktype = -1U, orig_nl = -1U, label_stack_depth = -1U; /* XXX */ #ifdef PCAP_FDDIPAD @@ -135,6 +135,7 @@ static struct block *root; * is relative to. */ enum e_offrel { + OR_PACKET, /* relative to the beginning of the packet */ 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 */ @@ -179,6 +180,7 @@ static struct block *gen_mcmp(enum e_offrel, u_int, u_int, bpf_int32, static struct block *gen_bcmp(enum e_offrel, u_int, u_int, const u_char *); static struct block *gen_ncmp(enum e_offrel, bpf_u_int32, bpf_u_int32, bpf_u_int32, bpf_u_int32, int, bpf_int32); +static struct slist *gen_load_llrel(u_int, u_int); static struct slist *gen_load_a(enum e_offrel, u_int, u_int); static struct slist *gen_loadx_iphdrlen(void); static struct block *gen_uncond(int); @@ -186,6 +188,9 @@ static inline struct block *gen_true(void); static inline struct block *gen_false(void); static struct block *gen_ether_linktype(int); static struct block *gen_linux_sll_linktype(int); +static void insert_radiotap_load_llprefixlen(struct block *); +static void insert_load_llprefixlen(struct block *); +static struct slist *gen_llprefixlen(void); static struct block *gen_linktype(int); static struct block *gen_snap(bpf_u_int32, bpf_u_int32, u_int); static struct block *gen_llc_linktype(int); @@ -200,9 +205,10 @@ static struct block *gen_thostop(const u_char *, int); static struct block *gen_wlanhostop(const u_char *, int); static struct block *gen_ipfchostop(const u_char *, int); static struct block *gen_dnhostop(bpf_u_int32, int); -static struct block *gen_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); @@ -474,6 +480,23 @@ finish_parse(p) p->sense = !p->sense; backpatch(p, gen_retblk(0)); root = p->head; + + /* + * 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, as we're currently only + * handling variable-length radiotap headers, and as all + * filtering expressions other than raw link[M:N] tests + * require the length of that header, doing more for that + * header length isn't really worth the effort. + */ + insert_load_llprefixlen(root); } void @@ -634,18 +657,37 @@ gen_ncmp(offrel, offset, size, mask, jtype, reverse, v) /* * Various code constructs need to know the layout of the data link - * layer. These variables give the necessary offsets. + * layer. These variables give the necessary offsets from the beginning + * of the packet data. + * + * If the link layer has variable_length headers, the offsets are offsets + * from the end of the link-link-layer header, and "reg_ll_size" is + * the register number for a register containing the length of the + * link-layer header. Otherwise, "reg_ll_size" is -1. + */ +static int reg_ll_size; + +/* + * This is the offset of the beginning of the link-layer header from + * the beginning of the raw packet data. + * + * It's usually 0, except for 802.11 with a fixed-length radio header. + * (For 802.11 with a variable-length radio header, we have to generate + * code to compute that offset; off_ll is 0 in that case.) */ +static u_int off_ll; /* * This is the offset of the beginning of the MAC-layer header. - * It's usually 0, except for ATM LANE. + * It's usually 0, except for ATM LANE, where it's the offset, relative + * to the beginning of the raw packet data, of the Ethernet header. */ static u_int off_mac; /* * "off_linktype" is the offset to information in the link-layer header - * giving the packet type. + * giving the packet type. This offset is relative to the beginning + * of the link-layer header (i.e., it doesn't include off_ll). * * For Ethernet, it's the offset of the Ethernet type field. * @@ -682,6 +724,14 @@ static u_int off_vpi; static u_int off_vci; static u_int off_proto; +/* + * 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. @@ -690,6 +740,8 @@ static u_int off_payload; /* * These are offsets to the beginning of the network-layer header. + * They are relative to the beginning of the link-layer header (i.e., + * they don't include off_ll). * * If the link layer never uses 802.2 LLC: * @@ -735,8 +787,24 @@ init_linktype(p) off_proto = -1; off_payload = -1; + /* + * And assume we're not doing SS7. + */ + off_sio = -1; + off_opc = -1; + off_dpc = -1; + off_sls = -1; + + /* + * Also assume it's not 802.11 with a fixed-length radio header. + */ + off_ll = 0; + orig_linktype = -1; orig_nl = -1; + label_stack_depth = 0; + + reg_ll_size = -1; switch (linktype) { @@ -895,9 +963,10 @@ init_linktype(p) * 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 */ + off_ll = 144; + off_linktype = 24; + off_nl = 32; /* Prism+802.11+802.2+SNAP */ + off_nl_nosnap = 27; /* Prism+802.11+802.2 */ return; case DLT_IEEE802_11_RADIO_AVS: @@ -913,11 +982,23 @@ init_linktype(p) * 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. + * of the radio header. We should handle that the + * same way we handle the length at the beginning + * of the radiotap header. + * + * XXX - in Linux, do any drivers that supply an AVS + * header supply a link-layer type other than + * ARPHRD_IEEE80211_PRISM? If so, we should map that + * to DLT_IEEE802_11_RADIO_AVS; if not, or if there are + * any drivers that supply an AVS header but supply + * an ARPHRD value of ARPHRD_IEEE80211_PRISM, we'll + * have to check the header in the generated code to + * determine whether it's Prism or AVS. */ - off_linktype = 64+24; - off_nl = 64+32; /* Radio+802.11+802.2+SNAP */ - off_nl_nosnap = 64+27; /* Radio+802.11+802.2 */ + off_ll = 64; + off_linktype = 24; + off_nl = 32; /* Radio+802.11+802.2+SNAP */ + off_nl_nosnap = 27; /* Radio+802.11+802.2 */ return; case DLT_IEEE802_11_RADIO: @@ -926,21 +1007,14 @@ init_linktype(p) * 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. + * The radiotap header is variable length, and we + * generate code to compute its length and store it + * in a register. These offsets are relative to the + * beginning of the 802.11 header. */ - off_linktype = -1; - off_nl = -1; - off_nl_nosnap = -1; + off_linktype = 24; + off_nl = 32; /* 802.11+802.2+SNAP */ + off_nl_nosnap = 27; /* 802.11+802.2 */ return; case DLT_ATM_RFC1483: @@ -948,6 +1022,13 @@ init_linktype(p) /* * 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_nl = 8; /* 802.2+SNAP */ @@ -1019,6 +1100,17 @@ init_linktype(p) off_nl_nosnap = 0; /* no 802.2 LLC */ return; + /* + * the only BPF-interesting FRF.16 frames are non-control frames; + * Frame Relay has a variable length link-layer + * so lets start with offset 4 for now and increments later on (FIXME); + */ + case DLT_MFR: + off_linktype = -1; + off_nl = 4; + off_nl_nosnap = 0; /* XXX - for now -> no 802.2 LLC */ + return; + case DLT_APPLE_IP_OVER_IEEE1394: off_linktype = 16; off_nl = 18; @@ -1056,8 +1148,12 @@ init_linktype(p) off_nl_nosnap = PFLOG_HDRLEN; /* no 802.2 LLC */ return; + case DLT_JUNIPER_MFR: case DLT_JUNIPER_MLFR: case DLT_JUNIPER_MLPPP: + case DLT_JUNIPER_PPP: + case DLT_JUNIPER_CHDLC: + case DLT_JUNIPER_FRELAY: off_linktype = 4; off_nl = 4; off_nl_nosnap = -1; /* no 802.2 LLC */ @@ -1075,6 +1171,55 @@ init_linktype(p) off_nl_nosnap = 18; return; + /* frames captured on a Juniper PPPoE service PIC + * contain raw ethernet frames */ + case DLT_JUNIPER_PPPOE: + case DLT_JUNIPER_ETHER: + off_linktype = 16; + off_nl = 18; /* Ethernet II */ + off_nl_nosnap = 21; /* 802.3+802.2 */ + return; + + case DLT_JUNIPER_PPPOE_ATM: + off_linktype = 4; + off_nl = 6; + off_nl_nosnap = -1; /* no 802.2 LLC */ + return; + + case DLT_JUNIPER_GGSN: + off_linktype = 6; + off_nl = 12; + off_nl_nosnap = -1; /* no 802.2 LLC */ + return; + + case DLT_JUNIPER_ES: + off_linktype = 6; + off_nl = -1; /* not really a network layer but raw IP adresses */ + off_nl_nosnap = -1; /* no 802.2 LLC */ + return; + + case DLT_JUNIPER_MONITOR: + off_linktype = 12; + off_nl = 12; /* raw IP/IP6 header */ + off_nl_nosnap = -1; /* no 802.2 LLC */ + return; + + case DLT_JUNIPER_SERVICES: + off_linktype = 12; + off_nl = -1; /* L3 proto location dep. on cookie type */ + off_nl_nosnap = -1; /* no 802.2 LLC */ + return; + + case DLT_MTP2: + off_sio = 3; + off_opc = 4; + off_dpc = 4; + off_sls = 7; + off_linktype = -1; + off_nl = -1; + off_nl_nosnap = -1; + return; + #ifdef DLT_PFSYNC case DLT_PFSYNC: off_linktype = -1; @@ -1096,6 +1241,39 @@ init_linktype(p) /* NOTREACHED */ } +/* + * Load a value relative to the beginning of the link-layer header. + * The link-layer header doesn't necessarily begin at the beginning + * of the packet data; there might be a variable-length prefix containing + * radio information. + */ +static struct slist * +gen_load_llrel(offset, size) + u_int offset, size; +{ + struct slist *s, *s2; + + s = gen_llprefixlen(); + + /* + * If "s" is non-null, it has code to arrange that the X register + * contains the length of the prefix preceding the link-layer + * header. + * + * Otherwise, the length of the prefix preceding the link-layer + * header is "off_ll". + */ + if (s != NULL) { + s2 = new_stmt(BPF_LD|BPF_IND|size); + s2->s.k = offset; + sappend(s, s2); + } else { + s = new_stmt(BPF_LD|BPF_ABS|size); + s->s.k = offset + off_ll; + } + return s; +} + /* * Load a value relative to the beginning of the specified header. */ @@ -1104,23 +1282,25 @@ gen_load_a(offrel, offset, size) enum e_offrel offrel; u_int offset, size; { - struct slist *s; + struct slist *s, *s2; switch (offrel) { + case OR_PACKET: + s = new_stmt(BPF_LD|BPF_ABS|size); + s->s.k = offset; + break; + case OR_LINK: - s = new_stmt(BPF_LD|BPF_ABS|size); - s->s.k = offset; + s = gen_load_llrel(offset, size); break; case OR_NET: - s = new_stmt(BPF_LD|BPF_ABS|size); - s->s.k = off_nl + offset; + s = gen_load_llrel(off_nl + offset, size); break; case OR_NET_NOSNAP: - s = new_stmt(BPF_LD|BPF_ABS|size); - s->s.k = off_nl_nosnap + offset; + s = gen_load_llrel(off_nl_nosnap + offset, size); break; case OR_TRAN_IPV4: @@ -1128,20 +1308,19 @@ gen_load_a(offrel, offset, size) * Load the X register with the length of the IPv4 header, * in bytes. */ - s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); - s->s.k = off_nl; + s = gen_loadx_iphdrlen(); /* * Load the item at {length of the link-layer header} + * {length of the IPv4 header} + {specified offset}. */ - s->next = new_stmt(BPF_LD|BPF_IND|size); - s->next->s.k = off_nl + offset; + s2 = new_stmt(BPF_LD|BPF_IND|size); + s2->s.k = off_nl + offset; + sappend(s, s2); break; case OR_TRAN_IPV6: - s = new_stmt(BPF_LD|BPF_ABS|size); - s->s.k = off_nl + 40 + offset; + s = gen_load_llrel(off_nl + 40 + offset, size); break; default: @@ -1152,16 +1331,55 @@ gen_load_a(offrel, offset, size) } /* - * 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 any variable-length header preceding the link-layer + * header. */ static struct slist * gen_loadx_iphdrlen() { - struct slist *s; + struct slist *s, *s2; - s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); - s->s.k = off_nl; + s = gen_llprefixlen(); + if (s != NULL) { + /* + * There's a variable-length prefix preceding the + * link-layer header. "s" points to a list of statements + * that put the length of that prefix into the X register. + * The 4*([k]&0xf) addressing mode can't be used, as we + * don't have a constant offset, so we have to load the + * value in question into the A register and add to it + * the value from the X register. + */ + s2 = new_stmt(BPF_LD|BPF_IND|BPF_B); + s2->s.k = off_nl; + sappend(s, s2); + s2 = new_stmt(BPF_ALU|BPF_AND|BPF_K); + s2->s.k = 0xf; + sappend(s, s2); + s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K); + s2->s.k = 2; + sappend(s, s2); + + /* + * The A register now contains the length of the + * IP header. We need to add to it the length + * of the prefix preceding the link-layer + * header, which is still in the X register, and + * move the result into the X register. + */ + sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); + sappend(s, new_stmt(BPF_MISC|BPF_TAX)); + } else { + /* + * There is no variable-length header preceding the + * link-layer header; if there's a fixed-length + * header preceding it, its length is included in + * the off_ variables, so it doesn't need to be added. + */ + s = new_stmt(BPF_LDX|BPF_MSH|BPF_B); + s->s.k = off_nl; + } return s; } @@ -1546,6 +1764,124 @@ gen_linux_sll_linktype(proto) } } +static void +insert_radiotap_load_llprefixlen(b) + struct block *b; +{ + struct slist *s1, *s2; + + /* + * Prepend to the statements in this block code to load the + * length of the radiotap header into the register assigned + * to hold that length, if one has been assigned. + */ + if (reg_ll_size != -1) { + /* + * The 2 bytes at offsets of 2 and 3 from the beginning + * of the radiotap header are the length of the radiotap + * header; unfortunately, it's little-endian, so we have + * to load it a byte at a time and construct the value. + */ + + /* + * Load the high-order byte, at an offset of 3, shift it + * left a byte, and put the result in the X register. + */ + s1 = new_stmt(BPF_LD|BPF_B|BPF_ABS); + s1->s.k = 3; + s2 = new_stmt(BPF_ALU|BPF_LSH|BPF_K); + sappend(s1, s2); + s2->s.k = 8; + s2 = new_stmt(BPF_MISC|BPF_TAX); + sappend(s1, s2); + + /* + * Load the next byte, at an offset of 2, and OR the + * value from the X register into it. + */ + s2 = new_stmt(BPF_LD|BPF_B|BPF_ABS); + sappend(s1, s2); + s2->s.k = 2; + s2 = new_stmt(BPF_ALU|BPF_OR|BPF_X); + sappend(s1, s2); + + /* + * Now allocate a register to hold that value and store + * it. + */ + s2 = new_stmt(BPF_ST); + s2->s.k = reg_ll_size; + sappend(s1, s2); + + /* + * Now move it into the X register. + */ + s2 = new_stmt(BPF_MISC|BPF_TAX); + sappend(s1, s2); + + /* + * Now append all the existing statements in this + * block to these statements. + */ + sappend(s1, b->stmts); + b->stmts = s1; + } +} + + +static void +insert_load_llprefixlen(b) + struct block *b; +{ + switch (linktype) { + + case DLT_IEEE802_11_RADIO: + insert_radiotap_load_llprefixlen(b); + } +} + + +static struct slist * +gen_radiotap_llprefixlen(void) +{ + struct slist *s; + + if (reg_ll_size == -1) { + /* + * We haven't yet assigned a register for the length + * of the radiotap header; allocate one. + */ + reg_ll_size = alloc_reg(); + } + + /* + * Load the register containing the radiotap length + * into the X register. + */ + s = new_stmt(BPF_LDX|BPF_MEM); + s->s.k = reg_ll_size; + return s; +} + +/* + * Generate code to compute the link-layer header length, if necessary, + * putting it into the X register, and to return either a pointer to a + * "struct slist" for the list of statements in that code, or NULL if + * no code is necessary. + */ +static struct slist * +gen_llprefixlen(void) +{ + switch (linktype) { + + case DLT_IEEE802_11_RADIO: + return gen_radiotap_llprefixlen(); + + default: + return NULL; + } +} + /* * Generate code to match a particular packet type by matching the * link-layer type field or fields in the 802.2 LLC header. @@ -1559,6 +1895,25 @@ gen_linktype(proto) { struct block *b0, *b1, *b2; + /* are we checking MPLS-encapsulated packets? */ + if (label_stack_depth > 0) { + switch (proto) { + case ETHERTYPE_IP: + case PPP_IP: + /* FIXME add other L3 proto IDs */ + return gen_mpls_linktype(Q_IP); + + case ETHERTYPE_IPV6: + case PPP_IPV6: + /* FIXME add other L3 proto IDs */ + return gen_mpls_linktype(Q_IPV6); + + default: + bpf_error("unsupported protocol over mpls"); + /* NOTREACHED */ + } + } + switch (linktype) { case DLT_EN10MB: @@ -1581,11 +1936,12 @@ gen_linktype(proto) } break; - case DLT_IEEE802_11: - case DLT_PRISM_HEADER: - case DLT_IEEE802_11_RADIO: case DLT_FDDI: case DLT_IEEE802: + case DLT_IEEE802_11: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PRISM_HEADER: case DLT_ATM_RFC1483: case DLT_ATM_CLIP: case DLT_IP_OVER_FC: @@ -1947,10 +2303,21 @@ gen_linktype(proto) /*NOTREACHED*/ 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: /* 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 @@ -2735,24 +3102,69 @@ gen_dnhostop(addr, dir) 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_host(addr, mask, proto, dir) +gen_mpls_linktype(proto) + int proto; +{ + struct block *b0, *b1; + + switch (proto) { + + case Q_IP: + /* match the bottom-of-stack bit */ + b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01); + /* match the IPv4 version number */ + b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x40, 0xf0); + gen_and(b0, b1); + return b1; + + case Q_IPV6: + /* match the bottom-of-stack bit */ + b0 = gen_mcmp(OR_NET, -2, BPF_B, 0x01, 0x01); + /* match the IPv4 version number */ + b1 = gen_mcmp(OR_NET, 0, BPF_B, 0x60, 0xf0); + gen_and(b0, b1); + return b1; + + default: + abort(); + } +} + +static struct block * +gen_host(addr, mask, proto, dir, type) bpf_u_int32 addr; bpf_u_int32 mask; int proto; int dir; + int type; { struct block *b0, *b1; + const char *typestr; + + if (type == Q_NET) + typestr = "net"; + else + typestr = "host"; switch (proto) { case Q_DEFAULT: - b0 = gen_host(addr, mask, Q_IP, dir); - 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; @@ -2766,28 +3178,28 @@ gen_host(addr, mask, proto, dir) 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_ATALK: bpf_error("ATALK host filtering not implemented"); @@ -2815,35 +3227,38 @@ gen_host(addr, mask, proto, dir) bpf_error("'ip6' modifier applied to ip host"); case Q_ICMPV6: - bpf_error("'icmp6' modifier applied to host"); + bpf_error("'icmp6' modifier applied to %s", typestr); #endif /* INET6 */ 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(); @@ -2853,49 +3268,57 @@ gen_host(addr, mask, proto, dir) #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_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_ATALK: bpf_error("ATALK host filtering not implemented"); @@ -2904,7 +3327,7 @@ gen_host6(addr, mask, proto, dir) 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"); @@ -2922,34 +3345,37 @@ gen_host6(addr, mask, proto, dir) 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(); @@ -2976,15 +3402,24 @@ gen_gateway(eaddr, alist, proto, dir) case Q_IP: case Q_ARP: case Q_RARP: - if (linktype == DLT_EN10MB) - b0 = gen_ehostop(eaddr, Q_OR); - else if (linktype == DLT_FDDI) - b0 = gen_fhostop(eaddr, Q_OR); - else if (linktype == DLT_IEEE802) - b0 = gen_thostop(eaddr, Q_OR); - else if (linktype == DLT_IEEE802_11) - b0 = gen_wlanhostop(eaddr, Q_OR); - else if (linktype == DLT_SUNATM && is_lane) { + switch (linktype) { + case DLT_EN10MB: + b0 = gen_ehostop(eaddr, Q_OR); + break; + case DLT_FDDI: + b0 = gen_fhostop(eaddr, Q_OR); + break; + case DLT_IEEE802: + b0 = gen_thostop(eaddr, Q_OR); + break; + case DLT_IEEE802_11: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PRISM_HEADER: + b0 = gen_wlanhostop(eaddr, Q_OR); + break; + case DLT_SUNATM: + if (is_lane) { /* * Check that the packet doesn't begin with an * LE Control marker. (We've already generated @@ -2999,15 +3434,19 @@ gen_gateway(eaddr, alist, proto, dir) */ b0 = gen_ehostop(eaddr, Q_OR); gen_and(b1, b0); - } else if (linktype == DLT_IP_OVER_FC) - b0 = gen_ipfchostop(eaddr, Q_OR); - else - bpf_error( + } + break; + case DLT_IP_OVER_FC: + b0 = gen_ipfchostop(eaddr, Q_OR); + break; + default: + bpf_error( "'gateway' supported only on ethernet/FDDI/token ring/802.11/Fibre Channel"); - - b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR); + } + 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; } @@ -3258,6 +3697,9 @@ gen_proto_abbrev(proto) b1 = gen_linktype(LLCSAP_NETBEUI); break; + case Q_RADIO: + bpf_error("'radio' is not a valid protocol type"); + default: abort(); } @@ -3280,6 +3722,15 @@ gen_ipfrag() 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; @@ -3755,6 +4206,19 @@ gen_protochain(v, proto, dir) /*NOTREACHED*/ } + /* + * We don't handle variable-length radiotap here headers 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 (linktype == DLT_IEEE802_11_RADIO) + bpf_error("'protochain' not supported with radiotap headers"); + no_optimize = 1; /*this code is not compatible with optimzer yet */ /* @@ -4060,6 +4524,7 @@ gen_proto(v, proto, dir) * * So we always check for ETHERTYPE_IP. */ + b0 = gen_linktype(ETHERTYPE_IP); #ifndef CHASE_CHAIN b1 = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)v); @@ -4220,6 +4685,9 @@ gen_proto(v, proto, dir) case Q_NETBEUI: bpf_error("'netbeui proto' is bogus"); + case Q_RADIO: + bpf_error("'radio proto' is bogus"); + default: abort(); /* NOTREACHED */ @@ -4262,7 +4730,7 @@ gen_scode(name, q) 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: @@ -4297,6 +4765,9 @@ gen_scode(name, q) return b; case DLT_IEEE802_11: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PRISM_HEADER: eaddr = pcap_ether_hostton(name); if (eaddr == NULL) bpf_error( @@ -4344,7 +4815,7 @@ gen_scode(name, q) * 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); @@ -4353,10 +4824,10 @@ gen_scode(name, q) tproto = proto; if (off_linktype == (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; } @@ -4381,7 +4852,7 @@ gen_scode(name, q) sin = (struct sockaddr_in *) res->ai_addr; tmp = gen_host(ntohl(sin->sin_addr.s_addr), - 0xffffffff, tproto, dir); + 0xffffffff, tproto, dir, q.addr); break; case AF_INET6: if (tproto6 == Q_IP) @@ -4390,7 +4861,7 @@ gen_scode(name, q) sin6 = (struct sockaddr_in6 *) res->ai_addr; tmp = gen_host6(&sin6->sin6_addr, - &mask128, tproto6, dir); + &mask128, tproto6, dir, q.addr); break; default: continue; @@ -4563,7 +5034,14 @@ gen_mcode(s1, s2, masklen, q) /* 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); @@ -4572,7 +5050,7 @@ gen_mcode(s1, s2, masklen, q) 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"); @@ -4605,7 +5083,7 @@ gen_ncode(s, v, q) 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 { @@ -4621,7 +5099,7 @@ gen_ncode(s, v, q) 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: @@ -4739,7 +5217,7 @@ gen_mcode6(s1, s2, masklen, q) /* FALLTHROUGH */ case Q_NET: - b = gen_host6(addr, &mask, q.proto, q.dir); + b = gen_host6(addr, &mask, q.proto, q.dir, q.addr); freeaddrinfo(res); return b; @@ -4758,15 +5236,20 @@ gen_ecode(eaddr, q) 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) - return gen_fhostop(eaddr, (int)q.dir); - if (linktype == DLT_IEEE802) - return gen_thostop(eaddr, (int)q.dir); - if (linktype == DLT_IEEE802_11) - return gen_wlanhostop(eaddr, (int)q.dir); - if (linktype == DLT_SUNATM && is_lane) { + switch (linktype) { + case DLT_EN10MB: + return gen_ehostop(eaddr, (int)q.dir); + case DLT_FDDI: + return gen_fhostop(eaddr, (int)q.dir); + case DLT_IEEE802: + return gen_thostop(eaddr, (int)q.dir); + case DLT_IEEE802_11: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PRISM_HEADER: + return gen_wlanhostop(eaddr, (int)q.dir); + case DLT_SUNATM: + if (is_lane) { /* * Check that the packet doesn't begin with an * LE Control marker. (We've already generated @@ -4783,9 +5266,13 @@ gen_ecode(eaddr, q) gen_and(tmp, b); return b; } - if (linktype == DLT_IP_OVER_FC) - return gen_ipfchostop(eaddr, (int)q.dir); + break; + case DLT_IP_OVER_FC: + return gen_ipfchostop(eaddr, (int)q.dir); + default: bpf_error("ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel"); + break; + } } bpf_error("ethernet address used in non-ether expression"); /* NOTREACHED */ @@ -4826,6 +5313,13 @@ xfer_to_a(a) 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) int proto; @@ -4858,8 +5352,36 @@ gen_load(proto, index, size) 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 specifed by "index". + */ + s = xfer_to_x(index); + + /* + * Load the item at that offset. + */ + tmp = new_stmt(BPF_LD|BPF_IND|size); + sappend(s, tmp); + sappend(index->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 @@ -4867,8 +5389,33 @@ gen_load(proto, index, size) * frame, so that 0 refers, for Ethernet LANE, to * the beginning of the destination address? */ - s = xfer_to_x(index); + s = gen_llprefixlen(); + + /* + * If "s" is non-null, it has code to arrange that the + * X register contains the length of the prefix preceding + * the link-layer header. Add to it the offset computed + * into the register specified by "index", and move that + * into the X register. Otherwise, just load into the X + * register the offset computed into the register specifed + * by "index". + */ + if (s != NULL) { + sappend(s, xfer_to_a(index)); + sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); + sappend(s, new_stmt(BPF_MISC|BPF_TAX)); + } else + s = xfer_to_x(index); + + /* + * Load the item at the sum of the offset we've put in the + * X register and the offset of the start of the link + * layer header (which is 0 if the radio header is + * variable-length; that header length is what we put + * into the X register and then added to the index). + */ tmp = new_stmt(BPF_LD|BPF_IND|size); + tmp->s.k = off_ll; sappend(s, tmp); sappend(index->s, s); break; @@ -4885,13 +5432,44 @@ gen_load(proto, index, size) #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_llprefixlen(); + + /* + * If "s" is non-null, it has code to arrange that the + * X register contains the length of the prefix preceding + * the link-layer header. Add to it the offset computed + * into the register specified by "index", and move that + * into the X register. Otherwise, just load into the X + * register the offset computed into the register specifed + * by "index". + */ + if (s != NULL) { + sappend(s, xfer_to_a(index)); + sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); + sappend(s, new_stmt(BPF_MISC|BPF_TAX)); + } else + s = xfer_to_x(index); + + /* + * Load the item at the sum of the offset we've put in the + * X register and the offset of the start of the network + * layer header. + */ tmp = new_stmt(BPF_LD|BPF_IND|size); tmp->s.k = off_nl; sappend(s, tmp); sappend(index->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); @@ -4906,7 +5484,29 @@ gen_load(proto, index, size) case Q_IGRP: case Q_PIM: case Q_VRRP: + /* + * The offset is relative to the beginning of + * the transport-layer header. + * 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(); + + /* + * The X register now contains the sum of the offset + * of the beginning of the link-layer header and + * the length of the network-layer header. Load + * into the A register the offset relative to + * the beginning of the transport layer header, + * add the X register to that, move that to the + * X register, and load with an offset from the + * X register equal to the offset of the network + * layer header relative to the beginning of + * the link-layer header. + */ sappend(s, xfer_to_a(index)); sappend(s, new_stmt(BPF_ALU|BPF_ADD|BPF_X)); sappend(s, new_stmt(BPF_MISC|BPF_TAX)); @@ -4914,6 +5514,12 @@ gen_load(proto, index, size) tmp->s.k = off_nl; sappend(index->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); @@ -5139,6 +5745,16 @@ gen_less(n) 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; @@ -5191,19 +5807,25 @@ gen_broadcast(proto) case Q_DEFAULT: case Q_LINK: - if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX) - return gen_ahostop(abroadcast, Q_DST); - if (linktype == DLT_EN10MB) - return gen_ehostop(ebroadcast, Q_DST); - if (linktype == DLT_FDDI) - return gen_fhostop(ebroadcast, Q_DST); - if (linktype == DLT_IEEE802) - return gen_thostop(ebroadcast, Q_DST); - if (linktype == DLT_IEEE802_11) - return gen_wlanhostop(ebroadcast, Q_DST); - if (linktype == DLT_IP_OVER_FC) - return gen_ipfchostop(ebroadcast, Q_DST); - if (linktype == DLT_SUNATM && is_lane) { + switch (linktype) { + case DLT_ARCNET: + case DLT_ARCNET_LINUX: + return gen_ahostop(abroadcast, Q_DST); + case DLT_EN10MB: + return gen_ehostop(ebroadcast, Q_DST); + case DLT_FDDI: + return gen_fhostop(ebroadcast, Q_DST); + case DLT_IEEE802: + return gen_thostop(ebroadcast, Q_DST); + case DLT_IEEE802_11: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PRISM_HEADER: + return gen_wlanhostop(ebroadcast, Q_DST); + case DLT_IP_OVER_FC: + return gen_ipfchostop(ebroadcast, Q_DST); + case DLT_SUNATM: + if (is_lane) { /* * Check that the packet doesn't begin with an * LE Control marker. (We've already generated @@ -5219,8 +5841,11 @@ gen_broadcast(proto) b0 = gen_ehostop(ebroadcast, Q_DST); gen_and(b1, b0); return b0; - } - bpf_error("not a broadcast link"); + } + break; + default: + bpf_error("not a broadcast link"); + } break; case Q_IP: @@ -5267,151 +5892,146 @@ gen_multicast(proto) case Q_DEFAULT: case Q_LINK: - if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX) - /* all ARCnet multicasts use the same address */ - return gen_ahostop(abroadcast, Q_DST); - - if (linktype == DLT_EN10MB) { - /* ether[0] & 1 != 0 */ - return gen_mac_multicast(0); - } - - if (linktype == DLT_FDDI) { - /* - * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX - * - * XXX - was that referring to bit-order issues? - */ - /* fddi[1] & 1 != 0 */ - return gen_mac_multicast(1); - } - - if (linktype == DLT_IEEE802) { - /* tr[2] & 1 != 0 */ - return gen_mac_multicast(2); - } - - if (linktype == DLT_IEEE802_11) { - /* - * Oh, yuk. - * - * For control frames, there is no DA. - * - * For management frames, DA is at an - * offset of 4 from the beginning of - * the packet. - * - * For data frames, DA is at an offset - * of 4 from the beginning of the packet - * if To DS is clear and at an offset of - * 16 from the beginning of the packet - * if To DS is set. - */ - - /* - * Generate the tests to be done for data frames. - * - * First, check for To DS set, i.e. "link[1] & 0x01". - */ - s = gen_load_a(OR_LINK, 1, BPF_B); - b1 = new_block(JMP(BPF_JSET)); - b1->s.k = 0x01; /* To DS */ - b1->stmts = s; - - /* - * If To DS is set, the DA is at 16. - */ - b0 = gen_mac_multicast(16); - gen_and(b1, b0); - - /* - * Now, check for To DS not set, i.e. check - * "!(link[1] & 0x01)". - */ - s = gen_load_a(OR_LINK, 1, BPF_B); - b2 = new_block(JMP(BPF_JSET)); - b2->s.k = 0x01; /* To DS */ - b2->stmts = s; - gen_not(b2); - - /* - * If To DS is not set, the DA is at 4. - */ - b1 = gen_mac_multicast(4); - gen_and(b2, b1); - - /* - * Now OR together the last two checks. That gives - * the complete set of checks for data frames. - */ - gen_or(b1, b0); - - /* - * Now check for a data frame. - * I.e, check "link[0] & 0x08". - */ - s = gen_load_a(OR_LINK, 0, BPF_B); - b1 = new_block(JMP(BPF_JSET)); - b1->s.k = 0x08; - b1->stmts = s; - - /* - * AND that with the checks done for data frames. - */ - gen_and(b1, b0); - - /* - * If the high-order bit of the type value is 0, this - * is a management frame. - * I.e, check "!(link[0] & 0x08)". - */ - s = gen_load_a(OR_LINK, 0, BPF_B); - b2 = new_block(JMP(BPF_JSET)); - b2->s.k = 0x08; - b2->stmts = s; - gen_not(b2); - - /* - * For management frames, the DA is at 4. - */ - b1 = gen_mac_multicast(4); - gen_and(b2, b1); - - /* - * OR that with the checks done for data frames. - * That gives the checks done for management and - * data frames. - */ - gen_or(b1, b0); - - /* - * If the low-order bit of the type value is 1, - * this is either a control frame or a frame - * with a reserved type, and thus not a - * frame with an SA. - * - * I.e., check "!(link[0] & 0x04)". - */ - s = gen_load_a(OR_LINK, 0, BPF_B); - b1 = new_block(JMP(BPF_JSET)); - b1->s.k = 0x04; - b1->stmts = s; - gen_not(b1); - - /* - * AND that with the checks for data and management - * frames. - */ - gen_and(b1, b0); - return b0; - } - - if (linktype == DLT_IP_OVER_FC) { - b0 = gen_mac_multicast(2); - return b0; - } - - if (linktype == DLT_SUNATM && is_lane) { + switch (linktype) { + case DLT_ARCNET: + case DLT_ARCNET_LINUX: + /* all ARCnet multicasts use the same address */ + return gen_ahostop(abroadcast, Q_DST); + case DLT_EN10MB: + /* ether[0] & 1 != 0 */ + return gen_mac_multicast(0); + case DLT_FDDI: + /* + * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX + * + * XXX - was that referring to bit-order issues? + */ + /* fddi[1] & 1 != 0 */ + return gen_mac_multicast(1); + case DLT_IEEE802: + /* tr[2] & 1 != 0 */ + return gen_mac_multicast(2); + case DLT_IEEE802_11: + case DLT_IEEE802_11_RADIO_AVS: + case DLT_IEEE802_11_RADIO: + case DLT_PRISM_HEADER: + /* + * Oh, yuk. + * + * For control frames, there is no DA. + * + * For management frames, DA is at an + * offset of 4 from the beginning of + * the packet. + * + * For data frames, DA is at an offset + * of 4 from the beginning of the packet + * if To DS is clear and at an offset of + * 16 from the beginning of the packet + * if To DS is set. + */ + + /* + * Generate the tests to be done for data frames. + * + * First, check for To DS set, i.e. "link[1] & 0x01". + */ + s = gen_load_a(OR_LINK, 1, BPF_B); + b1 = new_block(JMP(BPF_JSET)); + b1->s.k = 0x01; /* To DS */ + b1->stmts = s; + + /* + * If To DS is set, the DA is at 16. + */ + b0 = gen_mac_multicast(16); + gen_and(b1, b0); + + /* + * Now, check for To DS not set, i.e. check + * "!(link[1] & 0x01)". + */ + s = gen_load_a(OR_LINK, 1, BPF_B); + b2 = new_block(JMP(BPF_JSET)); + b2->s.k = 0x01; /* To DS */ + b2->stmts = s; + gen_not(b2); + + /* + * If To DS is not set, the DA is at 4. + */ + b1 = gen_mac_multicast(4); + gen_and(b2, b1); + + /* + * Now OR together the last two checks. That gives + * the complete set of checks for data frames. + */ + gen_or(b1, b0); + + /* + * Now check for a data frame. + * I.e, check "link[0] & 0x08". + */ + s = gen_load_a(OR_LINK, 0, BPF_B); + b1 = new_block(JMP(BPF_JSET)); + b1->s.k = 0x08; + b1->stmts = s; + + /* + * AND that with the checks done for data frames. + */ + gen_and(b1, b0); + + /* + * If the high-order bit of the type value is 0, this + * is a management frame. + * I.e, check "!(link[0] & 0x08)". + */ + s = gen_load_a(OR_LINK, 0, BPF_B); + b2 = new_block(JMP(BPF_JSET)); + b2->s.k = 0x08; + b2->stmts = s; + gen_not(b2); + + /* + * For management frames, the DA is at 4. + */ + b1 = gen_mac_multicast(4); + gen_and(b2, b1); + + /* + * OR that with the checks done for data frames. + * That gives the checks done for management and + * data frames. + */ + gen_or(b1, b0); + + /* + * If the low-order bit of the type value is 1, + * this is either a control frame or a frame + * with a reserved type, and thus not a + * frame with an SA. + * + * I.e., check "!(link[0] & 0x04)". + */ + s = gen_load_a(OR_LINK, 0, BPF_B); + b1 = new_block(JMP(BPF_JSET)); + b1->s.k = 0x04; + b1->stmts = s; + gen_not(b1); + + /* + * AND that with the checks for data and management + * frames. + */ + gen_and(b1, b0); + return b0; + case DLT_IP_OVER_FC: + b0 = gen_mac_multicast(2); + return b0; + case DLT_SUNATM: + if (is_lane) { /* * Check that the packet doesn't begin with an * LE Control marker. (We've already generated @@ -5425,10 +6045,13 @@ gen_multicast(proto) b0 = gen_mac_multicast(off_mac); gen_and(b1, b0); return b0; - } - - /* Link not known to support multicasts */ - break; + } + break; + default: + break; + } + /* Link not known to support multicasts */ + break; case Q_IP: b0 = gen_linktype(ETHERTYPE_IP); @@ -5506,10 +6129,21 @@ gen_inbound(dir) } 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: /* juniper flags (including direction) are stored * the byte after the 3-byte magic number */ if (dir) { @@ -5553,7 +6187,7 @@ gen_pf_ifname(const char *ifname) return (b0); } -/* PF firewall log matched interface */ +/* PF firewall log ruleset name */ struct block * gen_pf_ruleset(char *ruleset) { @@ -5692,7 +6326,11 @@ struct block * gen_vlan(vlan_num) int vlan_num; { - struct block *b0; + struct block *b0, *b1; + + /* 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 @@ -5724,30 +6362,28 @@ gen_vlan(vlan_num) * 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; + 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; - break; + case DLT_EN10MB: + off_linktype += 4; + off_nl_nosnap += 4; + off_nl += 4; + break; - default: - bpf_error("no VLAN support for data link type %d", - linktype); - /*NOTREACHED*/ - } + 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; - b1 = gen_mcmp(OR_LINK, orig_nl, BPF_H, (bpf_int32)vlan_num, 0x0fff); gen_and(b0, b1); @@ -5764,7 +6400,7 @@ struct block * gen_mpls(label_num) int label_num; { - struct block *b0; + struct block *b0,*b1; /* * Change the offsets to point to the type and data fields within @@ -5775,46 +6411,46 @@ gen_mpls(label_num) * * 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", + if (label_stack_depth > 0) { + /* just match the bottom-of-stack bit clear */ + b0 = gen_mcmp(OR_LINK, orig_nl-2, BPF_B, 0, 0x01); + } else { + /* + * Indicate that we're checking MPLS-encapsulated headers, + * to make sure higher level code generators don't try to + * match against IP-related protocols such as Q_ARP, Q_RARP + * etc. + */ + switch (linktype) { + + case DLT_C_HDLC: /* fall through */ + case DLT_EN10MB: + b0 = gen_cmp(OR_LINK, off_linktype, BPF_H, + (bpf_int32)ETHERTYPE_MPLS); + break; + + case DLT_PPP: + b0 = gen_cmp(OR_LINK, off_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", 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, 0xfffff000); /* only compare the first 20 bits */ @@ -5822,9 +6458,84 @@ gen_mpls(label_num) b0 = b1; } + 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() +{ + struct block *b0; + + /* + * Test against the PPPoE session link-layer type. + */ + b0 = gen_linktype((bpf_int32)ETHERTYPE_PPPOES); + + /* + * Change the offsets to point to the type and data fields within + * the PPP packet. + * + * XXX - this is a bit of a kludge. If we were to split the + * compiler into a parser that parses an expression and + * generates an expression tree, and a code generator that + * takes an expression tree (which could come from our + * parser or from some other parser) and generates BPF code, + * we could perhaps make the offsets parameters of routines + * and, in the handler for an "AND" node, pass to subnodes + * other than the PPPoE node the adjusted offsets. + * + * This would mean that "pppoes" would, instead of changing the + * behavior of *all* tests after it, change only the behavior + * of tests ANDed with it. That would change the documented + * semantics of "pppoes", which might break some expressions. + * However, it would mean that "(pppoes and ip) or ip" would check + * both for VLAN-encapsulated IP and IP-over-Ethernet, rather than + * checking only for VLAN-encapsulated IP, so that could still + * be considered worth doing; it wouldn't break expressions + * that are of the form "pppoes and ..." which I suspect are the + * most common expressions involving "pppoes". "pppoes or ..." + * doesn't necessarily do what the user would really want, now, + * as all the "or ..." tests would be done assuming PPPoE, even + * though the "or" could be viewed as meaning "or, if this isn't + * a PPPoE packet...". + */ + orig_linktype = off_linktype; /* save original values */ + orig_nl = off_nl; + + /* + * The "network-layer" protocol is PPPoE, which has a 6-byte + * PPPoE header, followed by PPP payload, so we set the + * offsets to the network layer offset plus 6 bytes for + * the PPPoE header plus the values appropriate for PPP when + * encapsulated in Ethernet (which means there's no HDLC + * encapsulation). + */ + off_linktype = orig_nl + 6; + off_nl = orig_nl + 6 + 2; + off_nl_nosnap = orig_nl + 6 + 2; + + /* + * Set the link-layer type to PPP, as all subsequent tests will + * be on the encapsulated PPP header. + */ + linktype = DLT_PPP; + + return b0; +} + struct block * gen_atmfield_code(atmfield, jvalue, jtype, reverse) int atmfield; @@ -5984,6 +6695,86 @@ gen_atmtype_abbrev(type) return b1; } +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; + + switch (mtp3field) { + + case M_SIO: + if (off_sio == (u_int)-1) + bpf_error("'sio' supported only on SS7"); + /* sio coded on 1 byte so max value 255 */ + if(jvalue > 255) + bpf_error("sio value %u too big; max value = 255", + jvalue); + b0 = gen_ncmp(OR_PACKET, off_sio, BPF_B, 0xffffffff, + (u_int)jtype, reverse, (u_int)jvalue); + break; + + case M_OPC: + if (off_opc == (u_int)-1) + bpf_error("'opc' supported only on SS7"); + /* opc coded on 14 bits so max value 16383 */ + if (jvalue > 16383) + bpf_error("opc value %u too big; max value = 16383", + jvalue); + /* the following instructions are made to convert jvalue + * to the form used to write opc in an ss7 message*/ + val1 = jvalue & 0x00003c00; + val1 = val1 >>10; + val2 = jvalue & 0x000003fc; + val2 = val2 <<6; + val3 = jvalue & 0x00000003; + val3 = val3 <<22; + jvalue = val1 + val2 + val3; + b0 = gen_ncmp(OR_PACKET, off_opc, BPF_W, 0x00c0ff0f, + (u_int)jtype, reverse, (u_int)jvalue); + break; + + case M_DPC: + if (off_dpc == (u_int)-1) + bpf_error("'dpc' supported only on SS7"); + /* dpc coded on 14 bits so max value 16383 */ + if (jvalue > 16383) + bpf_error("dpc value %u too big; max value = 16383", + jvalue); + /* the following instructions are made to convert jvalue + * to the forme used to write dpc in an ss7 message*/ + val1 = jvalue & 0x000000ff; + val1 = val1 << 24; + val2 = jvalue & 0x00003f00; + val2 = val2 << 8; + jvalue = val1 + val2; + b0 = gen_ncmp(OR_PACKET, off_dpc, BPF_W, 0xff3f0000, + (u_int)jtype, reverse, (u_int)jvalue); + break; + + case M_SLS: + if (off_sls == (u_int)-1) + bpf_error("'sls' supported only on SS7"); + /* sls coded on 4 bits so max value 15 */ + if (jvalue > 15) + bpf_error("sls value %u too big; max value = 15", + jvalue); + /* the following instruction is made to convert jvalue + * to the forme used to write sls in an ss7 message*/ + jvalue = jvalue << 4; + b0 = gen_ncmp(OR_PACKET, off_sls, BPF_B, 0xf0, + (u_int)jtype,reverse, (u_int)jvalue); + break; + + default: + abort(); + } + return b0; +} static struct block * gen_msg_abbrev(type)