]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-ip6.c
gre: add support for MikroTik Ethernet-over-IP hack.
[tcpdump] / print-ip6.c
index 1e09274b74866bf2bdc80dda37341772e12498bc..2f1183c00699b577dc4d5723cc558899b74c085e 100644 (file)
@@ -77,7 +77,6 @@ ip6_finddst(netdissect_options *ndo, nd_ipv6 *dst,
                         * the header, in units of 8 octets, excluding
                         * the first 8 octets.
                         */
-                       ND_TCHECK_2(cp);
                        advance = (GET_U_1(cp + 1) + 1) << 3;
                        nh = GET_U_1(cp);
                        break;
@@ -88,7 +87,6 @@ ip6_finddst(netdissect_options *ndo, nd_ipv6 *dst,
                         * marked as reserved, and the header is always
                         * the same size.
                         */
-                       ND_TCHECK_1(cp);
                        advance = sizeof(struct ip6_frag);
                        nh = GET_U_1(cp);
                        break;
@@ -233,11 +231,12 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
        u_int total_advance;
        const u_char *cp;
        uint32_t payload_len;
-       uint8_t nh;
+       uint8_t ph, nh;
        int fragmented = 0;
        u_int flow;
        int found_extension_header;
        int found_jumbo;
+       int found_hbh;
 
        ndo->ndo_protocol = "ip6";
        ip6 = (const struct ip6_hdr *)bp;
@@ -248,12 +247,12 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
                return;
        }
 
-        if (!ndo->ndo_eflag)
-            ND_PRINT("IP6 ");
+       if (!ndo->ndo_eflag)
+           ND_PRINT("IP6 ");
 
        if (IP6_VERSION(ip6) != 6) {
-          ND_PRINT("version error: %u != 6", IP6_VERSION(ip6));
-          return;
+         ND_PRINT("version error: %u != 6", IP6_VERSION(ip6));
+         return;
        }
 
        payload_len = GET_BE_U_2(ip6->ip6_plen);
@@ -287,35 +286,31 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
        } else
                len = length + sizeof(struct ip6_hdr);
 
-        nh = GET_U_1(ip6->ip6_nxt);
-        if (ndo->ndo_vflag) {
-            flow = GET_BE_U_4(ip6->ip6_flow);
-            ND_PRINT("(");
-#if 0
-            /* rfc1883 */
-            if (flow & 0x0f000000)
-               ND_PRINT("pri 0x%02x, ", (flow & 0x0f000000) >> 24);
-            if (flow & 0x00ffffff)
-               ND_PRINT("flowlabel 0x%06x, ", flow & 0x00ffffff);
-#else
-            /* RFC 2460 */
-            if (flow & 0x0ff00000)
-               ND_PRINT("class 0x%02x, ", (flow & 0x0ff00000) >> 20);
-            if (flow & 0x000fffff)
-               ND_PRINT("flowlabel 0x%05x, ", flow & 0x000fffff);
-#endif
-
-            ND_PRINT("hlim %u, next-header %s (%u) payload length: %u) ",
-                         GET_U_1(ip6->ip6_hlim),
-                         tok2str(ipproto_values,"unknown",nh),
-                         nh,
-                         payload_len);
-        }
+       ph = 255;
+       nh = GET_U_1(ip6->ip6_nxt);
+       if (ndo->ndo_vflag) {
+           flow = GET_BE_U_4(ip6->ip6_flow);
+           ND_PRINT("(");
+           /* RFC 2460 */
+           if (flow & 0x0ff00000)
+               ND_PRINT("class 0x%02x, ", (flow & 0x0ff00000) >> 20);
+           if (flow & 0x000fffff)
+               ND_PRINT("flowlabel 0x%05x, ", flow & 0x000fffff);
+
+           ND_PRINT("hlim %u, next-header %s (%u) payload length: %u) ",
+                        GET_U_1(ip6->ip6_hlim),
+                        tok2str(ipproto_values,"unknown",nh),
+                        nh,
+                        payload_len);
+       }
 
        /*
         * Cut off the snapshot length to the end of the IP payload.
         */
-       nd_push_snapend(ndo, bp + len);
+       if (!nd_push_snaplen(ndo, bp, len)) {
+               (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+                       "%s: can't push snaplen on buffer stack", __func__);
+       }
 
        cp = (const u_char *)ip6;
        advance = sizeof(struct ip6_hdr);
@@ -323,6 +318,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
        /* Process extension headers */
        found_extension_header = 0;
        found_jumbo = 0;
+       found_hbh = 0;
        while (cp < ndo->ndo_snapend && advance > 0) {
                if (len < (u_int)advance)
                        goto trunc;
@@ -340,12 +336,32 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
                switch (nh) {
 
                case IPPROTO_HOPOPTS:
+                       /*
+                        * The Hop-by-Hop Options header, when present,
+                        * must immediately follow the IPv6 header (RFC 8200)
+                        */
+                       if (found_hbh == 1) {
+                               ND_PRINT("[The Hop-by-Hop Options header was already found]");
+                               nd_print_invalid(ndo);
+                               return;
+                       }
+                       if (ph != 255) {
+                               ND_PRINT("[The Hop-by-Hop Options header don't follow the IPv6 header]");
+                               nd_print_invalid(ndo);
+                               return;
+                       }
                        advance = hbhopt_process(ndo, cp, &found_jumbo, &payload_len);
+                       if (payload_len == 0 && found_jumbo == 0) {
+                               ND_PRINT("[No valid Jumbo Payload Hop-by-Hop option found]");
+                               nd_print_invalid(ndo);
+                               return;
+                       }
                        if (advance < 0) {
                                nd_pop_packet_info(ndo);
                                return;
                        }
                        found_extension_header = 1;
+                       found_hbh = 1;
                        nh = GET_U_1(cp);
                        break;
 
@@ -376,7 +392,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
                         * XXX - we don't use "advance"; RFC 3775 says that
                         * the next header field in a mobility header
                         * should be IPPROTO_NONE, but speaks of
-                        * the possiblity of a future extension in
+                        * the possibility of a future extension in
                         * which payload can be piggybacked atop a
                         * mobility header.
                         */
@@ -423,7 +439,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
                                if (length < len)
                                        ND_PRINT("truncated-ip6 - %u bytes missing!",
                                                len - length);
-                               nd_change_snapend(ndo, bp + len);
+                               nd_change_snaplen(ndo, bp, len);
 
                                /*
                                 * Now subtract the length of the IPv6
@@ -448,7 +464,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
                                                goto trunc;
 
                                        /*
-                                        * OK, we didn't see any extnesion
+                                        * OK, we didn't see any extension
                                         * header, but that means we have
                                         * no payload, so set the length
                                         * to the IPv6 header length,
@@ -456,7 +472,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
                                         * accordingly.
                                         */
                                        len = sizeof(struct ip6_hdr);
-                                       nd_change_snapend(ndo, bp + len);
+                                       nd_change_snaplen(ndo, bp, len);
 
                                        /*
                                         * Now subtract the length of
@@ -473,6 +489,7 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
                        nd_pop_packet_info(ndo);
                        return;
                }
+               ph = nh;
 
                /* ndo_protocol reassignment after xxx_print() calls */
                ndo->ndo_protocol = "ip6";