Don't do IPv6 stuff if INET6 isn't defined.

[tcpdump] / print-pim.c

diff --git a/print-pim.c b/print-pim.c
index 72a6166db65936f221ffd1a6bc8cc727ee24cf92..788af2146902b48fc67f58d59d5f8c8a56a5920c 100644 (file)
--- a/print-pim.c
+++ b/print-pim.c
@@ -31,6 +31,7 @@
 #include "extract.h"
 
 #include "ip.h"
+#include "ip6.h"
 
 #define PIMV1_TYPE_QUERY           0
 #define PIMV1_TYPE_REGISTER        1
@@ -134,7 +135,7 @@ struct pim {
        u_short pim_cksum;      /* IP style check sum */
 };
 
-static void pimv2_print(netdissect_options *, register const u_char *bp, register u_int len, u_int cksum);
+static void pimv2_print(netdissect_options *, register const u_char *bp, register u_int len, const u_char *);
 
 static void
 pimv1_join_prune_print(netdissect_options *ndo,
@@ -415,7 +416,7 @@ trunc:
 
 void
 pim_print(netdissect_options *ndo,
-          register const u_char *bp, register u_int len, u_int cksum)
+          register const u_char *bp, register u_int len, const u_char *bp2)
 {
        register const u_char *ep;
        register struct pim *pim = (struct pim *)bp;
@@ -440,7 +441,7 @@ pim_print(netdissect_options *ndo,
                                  PIM_VER(pim->pim_typever),
                                  len,
                                  tok2str(pimv2_type_values,"Unknown Type",PIM_TYPE(pim->pim_typever))));
-                       pimv2_print(ndo, bp, len, cksum);
+                       pimv2_print(ndo, bp, len, bp2);
                }
                break;
        default:
@@ -620,13 +621,47 @@ trunc:
        return -1;
 }
 
+enum checksum_status {
+       CORRECT,
+       INCORRECT,
+       UNVERIFIED
+};
+
+static enum checksum_status
+pimv2_check_checksum(const u_char *bp, const u_char *bp2, u_int len)
+{
+       const struct ip *ip;
+       u_int cksum;
+
+       ip = (const struct ip *)bp2;
+       if (IP_V(ip) == 4) {
+               struct cksum_vec vec[1];
+
+               vec[0].ptr = bp;
+               vec[0].len = len;
+               cksum = in_cksum(vec, 1);
+               return (cksum ? INCORRECT : CORRECT);
+#ifdef INET6
+       } else if (IP_V(ip) == 6) {
+               const struct ip6_hdr *ip6;
+
+               ip6 = (const struct ip6_hdr *)bp2;
+               cksum = nextproto6_cksum(ip6, bp, len, len, IPPROTO_PIM);
+               return (cksum ? INCORRECT : CORRECT);
+#endif
+       } else {
+               return (UNVERIFIED);
+       }
+}
+
 static void
 pimv2_print(netdissect_options *ndo,
-            register const u_char *bp, register u_int len, u_int cksum)
+            register const u_char *bp, register u_int len, const u_char *bp2)
 {
        register const u_char *ep;
        register struct pim *pim = (struct pim *)bp;
        int advance;
+       enum checksum_status cksum_status;
 
        ep = (const u_char *)ndo->ndo_snapend;
        if (bp >= ep)
@@ -642,7 +677,41 @@ pimv2_print(netdissect_options *ndo,
        if (EXTRACT_16BITS(&pim->pim_cksum) == 0) {
                ND_PRINT((ndo, "(unverified)"));
        } else {
-               ND_PRINT((ndo, "(%scorrect)", ND_TTEST2(bp[0], len) && cksum ? "in" : "" ));
+               if (PIM_TYPE(pim->pim_typever) == PIMV2_TYPE_REGISTER) {
+                       /*
+                        * The checksum only covers the packet header,
+                        * not the encapsulated packet.
+                        */
+                       cksum_status = pimv2_check_checksum(bp, bp2, 8);
+                       if (cksum_status == INCORRECT) {
+                               /*
+                                * To quote RFC 4601, "For interoperability
+                                * reasons, a message carrying a checksum
+                                * calculated over the entire PIM Register
+                                * message should also be accepted."
+                                */
+                               cksum_status = pimv2_check_checksum(bp, bp2, len);
+                       }
+               } else {
+                       /*
+                        * The checksum covers the entire packet.
+                        */
+                       cksum_status = pimv2_check_checksum(bp, bp2, len);
+               }
+               switch (cksum_status) {
+
+               case CORRECT:
+                       ND_PRINT((ndo, "(correct)"));
+                       break;
+
+               case INCORRECT:
+                       ND_PRINT((ndo, "(incorrect)"));
+                       break;
+
+               case UNVERIFIED:
+                       ND_PRINT((ndo, "(unverified)"));
+                       break;
+               }
        }
 
        switch (PIM_TYPE(pim->pim_typever)) {
@@ -748,8 +817,7 @@ pimv2_print(netdissect_options *ndo,
        {
                struct ip *ip;
 
-               if (!ND_TTEST2(*(bp+4), PIMV2_REGISTER_FLAG_LEN))
-                       goto trunc;
+               ND_TCHECK2(*(bp + 4), PIMV2_REGISTER_FLAG_LEN);
 
                ND_PRINT((ndo, ", Flags [ %s ]\n\t",
                          tok2str(pimv2_register_flag_values,
@@ -769,11 +837,11 @@ pimv2_print(netdissect_options *ndo,
                case 4: /* IPv4 */
                        ip_print(ndo, bp, len);
                        break;
-#ifdef INET6
+
                case 6: /* IPv6 */
                        ip6_print(ndo, bp, len);
                        break;
-#endif
+
                default:
                        ND_PRINT((ndo, "IP ver %d", IP_V(ip)));
                        break;