add support for further dissection of the IPCP Compression Option

diff --git a/print-ppp.c b/print-ppp.c
index f4ca3a82051910dac07a297735b3605c4033aec4..708e934fd82906294427df3ba90ef967ab4674f6 100644 (file)
--- a/print-ppp.c
+++ b/print-ppp.c
@@ -31,7 +31,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-ppp.c,v 1.113 2005-11-03 07:30:25 hannes Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-ppp.c,v 1.114 2005-12-05 11:35:58 hannes Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -296,6 +296,20 @@ struct tok ipcpopt_values[] = {
        { 0,              NULL }
 };
 
+#define IPCPOPT_IPCOMP_HDRCOMP 0x61  /* rfc3544 */
+#define IPCPOPT_IPCOMP_MINLEN    14
+
+struct tok ipcpopt_compproto_values[] = {
+        { PPP_VJC, "VJ-Comp" },
+        { IPCPOPT_IPCOMP_HDRCOMP, "IP Header Compression" },
+       { 0,              NULL }
+};
+
+struct tok ipcpopt_compproto_subopt_values[] = {
+        { 1, "RTP-Compression" },
+        { 2, "Enhanced RTP-Compression" },
+       { 0,              NULL }
+};
 
 /* IP6CP Config Options */
 #define IP6CP_IFID      1
@@ -965,6 +979,7 @@ static int
 print_ipcp_config_options(const u_char *p, int length)
 {
        int len, opt;
+        u_int compproto, ipcomp_subopttotallen, ipcomp_subopt, ipcomp_suboptlen;
 
        if (length < 2)
                return 0;
@@ -999,11 +1014,62 @@ print_ipcp_config_options(const u_char *p, int length)
                if (len < 4)
                        goto invlen;
                TCHECK2(*(p + 2), 2);
-               if (EXTRACT_16BITS(p + 2) == PPP_VJC) {
-                       printf("VJ-Comp");
+                compproto = EXTRACT_16BITS(p+2);
+
+                printf("%s (0x%02x):",
+                       tok2str(ipcpopt_compproto_values,"Unknown",compproto),
+                       compproto);
+
+               switch (compproto) {
+                case PPP_VJC:
                        /* XXX: VJ-Comp parameters should be decoded */
-               } else
-                       printf("unknown-comp-proto %04x", EXTRACT_16BITS(p + 2));
+                        break;
+                case IPCPOPT_IPCOMP_HDRCOMP:
+                        if (len < IPCPOPT_IPCOMP_MINLEN)
+                                goto invlen;
+
+                        TCHECK2(*(p + 2), IPCPOPT_IPCOMP_MINLEN);
+                        printf("\n\t    TCP Space %u, non-TCP Space %u" \
+                               ", maxPeriod %u, maxTime %u, maxHdr %u",
+                               EXTRACT_16BITS(p+4),
+                               EXTRACT_16BITS(p+6),
+                               EXTRACT_16BITS(p+8),
+                               EXTRACT_16BITS(p+10),
+                               EXTRACT_16BITS(p+12));
+
+                        /* suboptions present ? */
+                        if (len > IPCPOPT_IPCOMP_MINLEN) {
+                                ipcomp_subopttotallen = len - IPCPOPT_IPCOMP_MINLEN;
+                                p += IPCPOPT_IPCOMP_MINLEN;
+                                
+                                printf("\n\t      Suboptions, length %u", ipcomp_subopttotallen);
+
+                                while (ipcomp_subopttotallen >= 2) {
+                                        TCHECK2(*p, 2);
+                                        ipcomp_subopt = *p;
+                                        ipcomp_suboptlen = *(p+1);
+                                        
+                                        /* sanity check */
+                                        if (ipcomp_subopt == 0 ||
+                                            ipcomp_suboptlen == 0 )
+                                                break;
+
+                                        /* XXX: just display the suboptions for now */
+                                        printf("\n\t\t%s Suboption #%u, length %u",
+                                               tok2str(ipcpopt_compproto_subopt_values,
+                                                       "Unknown",
+                                                       ipcomp_subopt),
+                                               ipcomp_subopt,
+                                               ipcomp_suboptlen);
+
+                                        ipcomp_subopttotallen -= ipcomp_suboptlen;
+                                        p += ipcomp_suboptlen;
+                                }
+                        }
+                        break;
+                default:
+                        break;
+               }
                break;
 
        case IPCPOPT_ADDR:     /* those options share the same format - fall through */