-add basic support for IP6CP

[tcpdump] / print-tcp.c

diff --git a/print-tcp.c b/print-tcp.c
index d3462063ab639b40023b84f21440fec2996f22f7..1ccebaae004bfa9bc59c1f850bd92628b1ad7953 100644 (file)
--- a/print-tcp.c
+++ b/print-tcp.c
@@ -21,7 +21,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.115 2004-05-27 21:20:50 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.117 2004-07-15 00:13:01 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -219,11 +219,12 @@ tcp_print(register const u_char *bp, register u_int length,
        hlen = TH_OFF(tp) * 4;
 
        /*
-        * If data present and NFS port used, assume NFS.
+        * If data present, header length valid, and NFS port used,
+        * assume NFS.
         * Pass offset of data plus 4 bytes for RPC TCP msg length
         * to NFS print routines.
         */
-       if (!qflag) {
+       if (!qflag && hlen >= sizeof(*tp) && hlen <= length) {
                if ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
                    dport == NFS_PORT) {
                        nfsreq_print((u_char *)tp + hlen + 4, length - hlen,
@@ -264,6 +265,12 @@ tcp_print(register const u_char *bp, register u_int length,
                }
        }
 
+       if (hlen < sizeof(*tp)) {
+               (void)printf(" tcp %d [bad hdr length %u - too short, < %lu]",
+                   length - hlen, hlen, (unsigned long)sizeof(*tp));
+               return;
+       }
+
        TCHECK(*tp);
 
        seq = EXTRACT_32BITS(&tp->th_seq);
@@ -272,7 +279,11 @@ tcp_print(register const u_char *bp, register u_int length,
        urp = EXTRACT_16BITS(&tp->th_urp);
 
        if (qflag) {
-               (void)printf("tcp %d", length - TH_OFF(tp) * 4);
+               (void)printf("tcp %d", length - hlen);
+               if (hlen > length) {
+                       (void)printf(" [bad hdr length %u - too long, > %u]",
+                           hlen, length);
+               }
                return;
        }
        if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|
@@ -398,7 +409,8 @@ tcp_print(register const u_char *bp, register u_int length,
                thseq = thack = threv = 0;
        }
        if (hlen > length) {
-               (void)printf(" [bad hdr length]");
+               (void)printf(" [bad hdr length %u - too long, > %u]",
+                   hlen, length);
                return;
        }