per suggestion from Paolo Lucente <[email protected]>:

  centralize the MPLS check into gen_linktype() and backout the
  specific checks in gen_proto_abrev(), gen_proto(), gen_host()

  this adds as a by-product support for IPv6

diff --git a/gencode.c b/gencode.c
index 4bd3c7d7c42becd1ec01805171510ca983ef19ba..e0ef7a7a6c997aaee9c3446366e56d6dbecf264f 100644 (file)
--- a/gencode.c
+++ b/gencode.c
@@ -21,7 +21,7 @@
  */
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.26 2005-07-11 13:58:52 hannes Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.27 2005-07-14 16:01:46 hannes Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -1853,6 +1853,23 @@ gen_linktype(proto)
 {
        struct block *b0, *b1, *b2;
 
+        /* has the linktype been poisoned by MPLS expression ? */
+        if (off_linktype == (u_int)-1) {
+                switch(proto) {
+                    /* FIXME add other L3 proto IDs */
+                case ETHERTYPE_IP:
+                case PPP_IP:
+                        return gen_null(Q_IP); 
+                    /* FIXME add other L3 proto IDs */
+                case ETHERTYPE_IPV6:
+                case PPP_IPV6:
+                        return gen_null(Q_IPV6); 
+                default:
+                    bpf_error("unsupported protocol over mpls");
+                    /* NOTREACHED */
+            }
+        }
+
        switch (linktype) {
 
        case DLT_EN10MB:
@@ -2450,10 +2467,7 @@ gen_hostop(addr, mask, dir, proto, src_off, dst_off)
        default:
                abort();
        }
-        if (off_linktype != (u_int)-1)
-            b0 = gen_linktype(proto);
-        else
-            b0 = gen_null(Q_IP);
+        b0 = gen_linktype(proto);
        b1 = gen_mcmp(OR_NET, offset, BPF_W, (bpf_int32)addr, mask);
        gen_and(b0, b1);
        return b1;
@@ -3438,10 +3452,7 @@ gen_proto_abbrev(proto)
                break;
 
        case Q_IP:
-                if (off_linktype != (u_int)-1)
-                    b1 = gen_linktype(ETHERTYPE_IP);
-                else
-                    b1 = gen_null(Q_IP); 
+                b1 = gen_linktype(ETHERTYPE_IP);
                break;
 
        case Q_ARP:
@@ -4434,10 +4445,7 @@ gen_proto(v, proto, dir)
                 * So we always check for ETHERTYPE_IP.
                 */
 
-                if (off_linktype != (u_int)-1)
-                    b0 = gen_linktype(ETHERTYPE_IP);
-                else
-                    b0 = gen_null(Q_IP); 
+                b0 = gen_linktype(ETHERTYPE_IP);
 #ifndef CHASE_CHAIN
                b1 = gen_cmp(OR_NET, 9, BPF_B, (bpf_int32)v);
 #else