Token Ring support, from various patches. Also add "tr" as an alias for

[libpcap] / gencode.c

diff --git a/gencode.c b/gencode.c
index cf78df8ce2e5381c96963a700549958513ae9471..b36a416da377193f55acbad8a3f921b1310d4741 100644 (file)
--- a/gencode.c
+++ b/gencode.c
@@ -21,7 +21,7 @@
  */
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.114 2000-07-13 06:51:56 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.115 2000-07-25 05:50:08 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -136,6 +136,7 @@ static struct block *gen_hostop6(struct in6_addr *, struct in6_addr *, int, int,
 #endif
 static struct block *gen_ehostop(const u_char *, int);
 static struct block *gen_fhostop(const u_char *, int);
+static struct block *gen_thostop(const u_char *, int);
 static struct block *gen_dnhostop(bpf_u_int32, int, u_int);
 static struct block *gen_host(bpf_u_int32, bpf_u_int32, int, int);
 #ifdef INET6
@@ -574,6 +575,8 @@ init_linktype(type)
                 * FDDI doesn't really have a link-level type field.
                 * We assume that SSAP = SNAP is being used and pick
                 * out the encapsulated Ethernet type.
+                *
+                * XXX - should we generate code to check for SNAP?
                 */
                off_linktype = 19;
 #ifdef PCAP_FDDIPAD
@@ -586,6 +589,28 @@ init_linktype(type)
                return;
 
        case DLT_IEEE802:
+               /*
+                * Token Ring doesn't really have a link-level type field.
+                * We assume that SSAP = SNAP is being used and pick
+                * out the encapsulated Ethernet type.
+                *
+                * XXX - should we generate code to check for SNAP?
+                *
+                * XXX - the header is actually variable-length.
+                * Some various Linux patched versions gave 38
+                * as "off_linktype" and 40 as "off_nl"; however,
+                * if a token ring packet has *no* routing
+                * information, i.e. is not source-routed, the correct
+                * values are 20 and 22, as they are in the vanilla code.
+                *
+                * A packet is source-routed iff the uppermost bit
+                * of the first byte of the source address, at an
+                * offset of 8, has the uppermost bit set.  If the
+                * packet is source-routed, the total number of bytes
+                * of routing information is 2 plus bits 0x1F00 of
+                * the 16-bit value at an offset of 14 (shifted right
+                * 8 - figure out which byte that is).
+                */
                off_linktype = 20;
                off_nl = 22;
                return;
@@ -874,6 +899,40 @@ gen_fhostop(eaddr, dir)
        /* NOTREACHED */
 }
 
+/*
+ * Like gen_ehostop, but for DLT_IEEE802 (Token Ring)
+ */
+static struct block *
+gen_thostop(eaddr, dir)
+       register const u_char *eaddr;
+       register int dir;
+{
+       register struct block *b0, *b1;
+
+       switch (dir) {
+       case Q_SRC:
+               return gen_bcmp(8, 6, eaddr);
+
+       case Q_DST:
+               return gen_bcmp(2, 6, eaddr);
+
+       case Q_AND:
+               b0 = gen_thostop(eaddr, Q_SRC);
+               b1 = gen_thostop(eaddr, Q_DST);
+               gen_and(b0, b1);
+               return b1;
+
+       case Q_DEFAULT:
+       case Q_OR:
+               b0 = gen_thostop(eaddr, Q_SRC);
+               b1 = gen_thostop(eaddr, Q_DST);
+               gen_or(b0, b1);
+               return b1;
+       }
+       abort();
+       /* NOTREACHED */
+}
+
 /*
  * This is quite tricky because there may be pad bytes in front of the
  * DECNET header, and then there are two possible data packet formats that
@@ -1151,9 +1210,11 @@ gen_gateway(eaddr, alist, proto, dir)
                        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
                        bpf_error(
-                           "'gateway' supported only on ethernet or FDDI");
+                           "'gateway' supported only on ethernet, FDDI or token ring");
 
                b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR);
                while (*alist) {
@@ -2015,9 +2076,16 @@ gen_scode(name, q)
                                            "unknown FDDI host '%s'", name);
                                return gen_fhostop(eaddr, dir);
 
+                       case DLT_IEEE802:
+                               eaddr = pcap_ether_hostton(name);
+                               if (eaddr == NULL)
+                                       bpf_error(
+                                           "unknown token ring host '%s'", name);
+                               return gen_thostop(eaddr, dir);
+
                        default:
                                bpf_error(
-                       "only ethernet/FDDI supports link-level host name");
+                       "only ethernet/FDDI/token ring supports link-level host name");
                                break;
                        }
                } else if (proto == Q_DECNET) {
@@ -2351,6 +2419,8 @@ gen_ecode(eaddr, q)
                        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);
        }
        bpf_error("ethernet address used in non-ether expression");
        /* NOTREACHED */
@@ -2748,6 +2818,8 @@ gen_broadcast(proto)
                        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);
                bpf_error("not a broadcast link");
                break;
 
@@ -2795,6 +2867,10 @@ gen_multicast(proto)
                        b0->stmts = s;
                        return b0;
                }
+
+               /* TODO - check how token ring handles multicast */
+               /* if (linktype == DLT_IEEE802) ... */
+
                /* Link not known to support multicasts */
                break;