IGMP fixes:

- Identify IGMPv1 and IGMPv2 instead of "report" and "nreport".
- Don't use questionably-portable bitfields for packet formats.
- Don't try to check the IGMP checksum if the packet was not completely
  captured.

diff --git a/print-ip.c b/print-ip.c
index bc1677451976c1baf4c1f546a71a17ebfd7b6bea..34be5c82c85b90a28f1b85bb4c7c7c1f544b47f3 100644 (file)
--- a/print-ip.c
+++ b/print-ip.c
@@ -21,7 +21,7 @@
 
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.76 1999-11-22 07:25:27 fenner Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.77 1999-11-23 08:31:10 fenner Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -70,21 +70,11 @@ struct tr_query {
        u_int  tr_src;                  /* traceroute source */
        u_int  tr_dst;                  /* traceroute destination */
        u_int  tr_raddr;                /* traceroute response address */
-#if defined(WORDS_BIGENDIAN) || (defined(BYTE_ORDER) && (BYTE_ORDER == BIG_ENDIAN))
-       struct {
-               u_int   ttl : 8;        /* traceroute response ttl */
-               u_int   qid : 24;       /* traceroute query id */
-       } q;
-#else
-       struct {
-               u_int   qid : 24;       /* traceroute query id */
-               u_int   ttl : 8;        /* traceroute response ttl */
-       } q;
-#endif
+       u_int  tr_rttlqid;              /* response ttl and qid */
 };
 
-#define tr_rttl q.ttl
-#define tr_qid  q.qid
+#define TR_GETTTL(x)           (((x) >> 24) & 0xff)
+#define TR_GETQID(x)           ((x) & 0x00ffffff)
 
 /*
  * Traceroute response format.  A traceroute response has a tr_query at the
@@ -129,22 +119,24 @@ static void print_mtrace(register const u_char *bp, register u_int len)
 {
        register struct tr_query *tr = (struct tr_query *)(bp + 8);
 
-       printf("mtrace %d: %s to %s reply-to %s", tr->tr_qid,
+       printf("mtrace %d: %s to %s reply-to %s",
+               TR_GETQID(ntohl(tr->tr_rttlqid)),
                ipaddr_string(&tr->tr_src), ipaddr_string(&tr->tr_dst),
                ipaddr_string(&tr->tr_raddr));
        if (IN_CLASSD(ntohl(tr->tr_raddr)))
-               printf(" with-ttl %d", tr->tr_rttl);
+               printf(" with-ttl %d", TR_GETTTL(ntohl(tr->tr_rttlqid)));
 }
 
 static void print_mresp(register const u_char *bp, register u_int len)
 {
        register struct tr_query *tr = (struct tr_query *)(bp + 8);
 
-       printf("mresp %d: %s to %s reply-to %s", tr->tr_qid,
+       printf("mresp %d: %s to %s reply-to %s",
+               TR_GETQID(ntohl(tr->tr_rttlqid)),
                ipaddr_string(&tr->tr_src), ipaddr_string(&tr->tr_dst),
                ipaddr_string(&tr->tr_raddr));
        if (IN_CLASSD(ntohl(tr->tr_raddr)))
-               printf(" with-ttl %d", tr->tr_rttl);
+               printf(" with-ttl %d", TR_GETTTL(ntohl(tr->tr_rttlqid)));
 }
 
 static void
@@ -158,22 +150,27 @@ igmp_print(register const u_char *bp, register u_int len,
                ipaddr_string(&ip->ip_src),
                ipaddr_string(&ip->ip_dst));
 
+       if (qflag) {
+               (void)printf("igmp");
+               return;
+       }
+
        TCHECK2(bp[0], 8);
        switch (bp[0]) {
        case 0x11:
                (void)printf("igmp query");
-               if (*(int *)&bp[4])
+               if (EXTRACT_32BITS(&bp[4]))
                        (void)printf(" [gaddr %s]", ipaddr_string(&bp[4]));
                if (len != 8)
                        (void)printf(" [len %d]", len);
                break;
        case 0x12:
-               (void)printf("igmp report %s", ipaddr_string(&bp[4]));
+               (void)printf("igmp v1 report %s", ipaddr_string(&bp[4]));
                if (len != 8)
                        (void)printf(" [len %d]", len);
                break;
        case 0x16:
-               (void)printf("igmp nreport %s", ipaddr_string(&bp[4]));
+               (void)printf("igmp v2 report %s", ipaddr_string(&bp[4]));
                break;
        case 0x17:
                (void)printf("igmp leave %s", ipaddr_string(&bp[4]));
@@ -186,7 +183,7 @@ igmp_print(register const u_char *bp, register u_int len,
                        dvmrp_print(bp, len);
                break;
        case 0x14:
-               (void)printf("igmp pim");
+               (void)printf("igmp pimv1");
                pimv1_print(bp, len);
                break;
        case 0x1e:
@@ -196,14 +193,11 @@ igmp_print(register const u_char *bp, register u_int len,
                print_mtrace(bp, len);
                break;
        default:
-               (void)printf("igmp-%d", bp[0] & 0xf);
+               (void)printf("igmp-%d", bp[0]);
                break;
        }
-       if ((bp[0] >> 4) != 1)
-               (void)printf(" [v%d]", bp[0] >> 4);
 
-       TCHECK2(bp[0], len);
-       if (vflag) {
+       if (vflag && TTEST2(bp[0], len)) {
                /* Check the IGMP checksum */
                if (in_cksum((const u_short*)bp, len, 0))
                        printf(" bad igmp cksum %x!", EXTRACT_16BITS(&bp[2]));