*/
#ifndef lint
static const char rcsid[] _U_ =
- "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.33 2005-08-31 06:50:02 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
static jmp_buf top_ctx;
static pcap_t *bpf_pcap;
-/* Hack for updating VLAN, MPLS offsets. */
+/* Hack for updating VLAN, MPLS, and PPPoE offsets. */
static u_int orig_linktype = -1U, orig_nl = -1U, label_stack_depth = -1U;
/* XXX */
static struct block *gen_ipfchostop(const u_char *, int);
static struct block *gen_dnhostop(bpf_u_int32, int);
static struct block *gen_mpls_linktype(int);
-static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int);
+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 int reg_ll_size;
/*
- * This is the offset of the beginning of the link-layer header.
+ * 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.
*
/*
* 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:
*
* the Prism header is fixed-length.
*/
off_ll = 144;
- 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_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:
* 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_ll = 64;
- 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_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:
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;
* 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);
sappend(s, s2);
} else {
s = new_stmt(BPF_LD|BPF_ABS|size);
- s->s.k = offset;
+ s->s.k = offset + off_ll;
}
return s;
}
switch (offrel) {
case OR_PACKET:
- s = gen_load_llrel(offset, size);
+ s = new_stmt(BPF_LD|BPF_ABS|size);
+ s->s.k = offset;
break;
case OR_LINK:
- s = gen_load_llrel(off_ll + offset, size);
+ s = gen_load_llrel(offset, size);
break;
case OR_NET:
}
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);
+ 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);
+ b1 = gen_host(addr, mask, Q_ARP, dir, type);
gen_or(b0, b1);
- b0 = gen_host(addr, mask, Q_RARP, dir);
+ 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_ATALK:
bpf_error("ATALK host filtering not implemented");
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 host");
+ 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_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");
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 host");
+ bpf_error("'radio' modifier applied to %s", typestr);
default:
abort();
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 ||
- linktype == DLT_IEEE802_11_RADIO_AVS ||
- linktype == DLT_IEEE802_11_RADIO ||
- linktype == DLT_PRISM_HEADER)
- 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
*/
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;
}
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:
* 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);
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;
}
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)
sin6 = (struct sockaddr_in6 *)
res->ai_addr;
tmp = gen_host6(&sin6->sin6_addr,
- &mask128, tproto6, dir);
+ &mask128, tproto6, dir, q.addr);
break;
default:
continue;
/* 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");
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:
/* 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;
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 ||
- linktype == DLT_IEEE802_11_RADIO_AVS ||
- linktype == DLT_IEEE802_11_RADIO ||
- linktype == DLT_PRISM_HEADER)
- 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
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 */
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 ||
- linktype == DLT_IEEE802_11_RADIO_AVS ||
- linktype == DLT_IEEE802_11_RADIO ||
- linktype == DLT_PRISM_HEADER)
- 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
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:
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 ||
- linktype == DLT_IEEE802_11_RADIO_AVS ||
- linktype == DLT_IEEE802_11_RADIO ||
- linktype == 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;
- }
-
- 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
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);
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;
projects / libpcap / blobdiff