]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-icmp.c
ZEP: Add a bounds check
[tcpdump] / print-icmp.c
index c83c809d93cff867a418005e961c6ac426438fe2..b0e13f4c8239be1d410ae62be726c9804954f24b 100644 (file)
@@ -92,7 +92,7 @@ struct icmp {
 /*
  * Lower bounds on packet lengths for various types.
  * For the error advice packets must first insure that the
- * packet is large enought to contain the returned ip header.
+ * packet is large enough to contain the returned ip header.
  * Only then can we do the check to see if 64 bits of packet
  * data have been returned, since we need to check the returned
  * ip header length.
@@ -226,7 +226,7 @@ struct id_rdiscovery {
  * The Destination Unreachable, Time Exceeded
  * and Parameter Problem messages are slightly changed as per
  * the above draft. A new Length field gets added to give
- * the caller an idea about the length of the piggypacked
+ * the caller an idea about the length of the piggybacked
  * IP packet before the MPLS extension header starts.
  *
  * The Length field represents length of the padded "original datagram"
@@ -286,7 +286,7 @@ icmp_tstamp_print(u_int tstamp)
     sec = tstamp / 1000;
     min = sec / 60; sec -= min * 60;
     hrs = min / 60; min -= hrs * 60;
-    nd_snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
+    snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
     return buf;
 }
 
@@ -305,7 +305,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
        const struct udphdr *ouh;
         const uint8_t *obj_tptr;
         uint32_t raw_label;
-        const u_char *snapend_save;
        const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
        u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype;
        uint16_t dport;
@@ -318,15 +317,13 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
        ip = (const struct ip *)bp2;
        str = buf;
 
-       ND_TCHECK_1(dp->icmp_code);
        icmp_type = GET_U_1(dp->icmp_type);
        icmp_code = GET_U_1(dp->icmp_code);
        switch (icmp_type) {
 
        case ICMP_ECHO:
        case ICMP_ECHOREPLY:
-               ND_TCHECK_2(dp->icmp_seq);
-               (void)nd_snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
+               (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
                                icmp_type == ICMP_ECHO ?
                                "request" : "reply",
                                GET_BE_U_2(dp->icmp_id),
@@ -334,26 +331,24 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                break;
 
        case ICMP_UNREACH:
-               ND_TCHECK_4(dp->icmp_ip.ip_dst);
                switch (icmp_code) {
 
                case ICMP_UNREACH_NET:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "net %s unreachable",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_HOST:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "host %s unreachable",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_PROTOCOL:
-                       ND_TCHECK_1(dp->icmp_ip.ip_p);
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "%s protocol %u unreachable",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst),
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
                            GET_U_1(dp->icmp_ip.ip_p));
                        break;
 
@@ -362,29 +357,28 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                        oip = &dp->icmp_ip;
                        hlen = IP_HL(oip) * 4;
                        ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
-                       ND_TCHECK_2(ouh->uh_dport);
                        dport = GET_BE_U_2(ouh->uh_dport);
                        ip_proto = GET_U_1(oip->ip_p);
                        switch (ip_proto) {
 
                        case IPPROTO_TCP:
-                               (void)nd_snprintf(buf, sizeof(buf),
+                               (void)snprintf(buf, sizeof(buf),
                                        "%s tcp port %s unreachable",
-                                       ipaddr_string(ndo, oip->ip_dst),
+                                       GET_IPADDR_STRING(oip->ip_dst),
                                        tcpport_string(ndo, dport));
                                break;
 
                        case IPPROTO_UDP:
-                               (void)nd_snprintf(buf, sizeof(buf),
+                               (void)snprintf(buf, sizeof(buf),
                                        "%s udp port %s unreachable",
-                                       ipaddr_string(ndo, oip->ip_dst),
+                                       GET_IPADDR_STRING(oip->ip_dst),
                                        udpport_string(ndo, dport));
                                break;
 
                        default:
-                               (void)nd_snprintf(buf, sizeof(buf),
+                               (void)snprintf(buf, sizeof(buf),
                                        "%s protocol %u port %u unreachable",
-                                       ipaddr_string(ndo, oip->ip_dst),
+                                       GET_IPADDR_STRING(oip->ip_dst),
                                        ip_proto, dport);
                                break;
                        }
@@ -396,129 +390,128 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                        mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void;
                        mtu = GET_BE_U_2(mp->nexthopmtu);
                        if (mtu) {
-                               (void)nd_snprintf(buf, sizeof(buf),
+                               (void)snprintf(buf, sizeof(buf),
                                    "%s unreachable - need to frag (mtu %u)",
-                                   ipaddr_string(ndo, dp->icmp_ip.ip_dst), mtu);
+                                   GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu);
                        } else {
-                               (void)nd_snprintf(buf, sizeof(buf),
+                               (void)snprintf(buf, sizeof(buf),
                                    "%s unreachable - need to frag",
-                                   ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                                   GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        }
                    }
                        break;
 
                case ICMP_UNREACH_SRCFAIL:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "%s unreachable - source route failed",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_NET_UNKNOWN:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "net %s unreachable - unknown",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_HOST_UNKNOWN:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "host %s unreachable - unknown",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_ISOLATED:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "%s unreachable - source host isolated",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_NET_PROHIB:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "net %s unreachable - admin prohibited",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_HOST_PROHIB:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "host %s unreachable - admin prohibited",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_TOSNET:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "net %s unreachable - tos prohibited",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_TOSHOST:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "host %s unreachable - tos prohibited",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_FILTER_PROHIB:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "host %s unreachable - admin prohibited filter",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_HOST_PRECEDENCE:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "host %s unreachable - host precedence violation",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                case ICMP_UNREACH_PRECEDENCE_CUTOFF:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "host %s unreachable - precedence cutoff",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
                        break;
 
                default:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "%s unreachable - #%u",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst),
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
                            icmp_code);
                        break;
                }
                break;
 
        case ICMP_REDIRECT:
-               ND_TCHECK_4(dp->icmp_ip.ip_dst);
                switch (icmp_code) {
 
                case ICMP_REDIRECT_NET:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "redirect %s to net %s",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst),
-                           ipaddr_string(ndo, dp->icmp_gwaddr));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+                           GET_IPADDR_STRING(dp->icmp_gwaddr));
                        break;
 
                case ICMP_REDIRECT_HOST:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "redirect %s to host %s",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst),
-                           ipaddr_string(ndo, dp->icmp_gwaddr));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+                           GET_IPADDR_STRING(dp->icmp_gwaddr));
                        break;
 
                case ICMP_REDIRECT_TOSNET:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "redirect-tos %s to net %s",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst),
-                           ipaddr_string(ndo, dp->icmp_gwaddr));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+                           GET_IPADDR_STRING(dp->icmp_gwaddr));
                        break;
 
                case ICMP_REDIRECT_TOSHOST:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "redirect-tos %s to host %s",
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst),
-                           ipaddr_string(ndo, dp->icmp_gwaddr));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+                           GET_IPADDR_STRING(dp->icmp_gwaddr));
                        break;
 
                default:
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "redirect-#%u %s to %s", icmp_code,
-                           ipaddr_string(ndo, dp->icmp_ip.ip_dst),
-                           ipaddr_string(ndo, dp->icmp_gwaddr));
+                           GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+                           GET_IPADDR_STRING(dp->icmp_gwaddr));
                        break;
                }
                break;
@@ -529,7 +522,7 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                const struct id_rdiscovery *idp;
                u_int lifetime, num, size;
 
-               (void)nd_snprintf(buf, sizeof(buf), "router advertisement");
+               (void)snprintf(buf, sizeof(buf), "router advertisement");
                cp = buf + strlen(buf);
 
                ihp = (const struct ih_rdiscovery *)&dp->icmp_void;
@@ -538,13 +531,13 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                cp = buf + strlen(buf);
                lifetime = GET_BE_U_2(ihp->ird_lifetime);
                if (lifetime < 60) {
-                       (void)nd_snprintf(cp, sizeof(buf) - (cp - buf), "%u",
+                       (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
                            lifetime);
                } else if (lifetime < 60 * 60) {
-                       (void)nd_snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
+                       (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
                            lifetime / 60, lifetime % 60);
                } else {
-                       (void)nd_snprintf(cp, sizeof(buf) - (cp - buf),
+                       (void)snprintf(cp, sizeof(buf) - (cp - buf),
                            "%u:%02u:%02u",
                            lifetime / 3600,
                            (lifetime % 3600) / 60,
@@ -553,20 +546,20 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                cp = buf + strlen(buf);
 
                num = GET_U_1(ihp->ird_addrnum);
-               (void)nd_snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num);
+               (void)snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num);
                cp = buf + strlen(buf);
 
                size = GET_U_1(ihp->ird_addrsiz);
                if (size != 2) {
-                       (void)nd_snprintf(cp, sizeof(buf) - (cp - buf),
+                       (void)snprintf(cp, sizeof(buf) - (cp - buf),
                            " [size %u]", size);
                        break;
                }
                idp = (const struct id_rdiscovery *)&dp->icmp_data;
                while (num > 0) {
                        ND_TCHECK_SIZE(idp);
-                       (void)nd_snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
-                           ipaddr_string(ndo, idp->ird_addr),
+                       (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
+                           GET_IPADDR_STRING(idp->ird_addr),
                            GET_BE_U_4(idp->ird_pref));
                        cp = buf + strlen(buf);
                        ++idp;
@@ -588,7 +581,7 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                        break;
 
                default:
-                       (void)nd_snprintf(buf, sizeof(buf), "time exceeded-#%u",
+                       (void)snprintf(buf, sizeof(buf), "time exceeded-#%u",
                            icmp_code);
                        break;
                }
@@ -596,25 +589,22 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
 
        case ICMP_PARAMPROB:
                if (icmp_code)
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "parameter problem - code %u", icmp_code);
                else {
-                       ND_TCHECK_1(dp->icmp_pptr);
-                       (void)nd_snprintf(buf, sizeof(buf),
+                       (void)snprintf(buf, sizeof(buf),
                            "parameter problem - octet %u",
                            GET_U_1(dp->icmp_pptr));
                }
                break;
 
        case ICMP_MASKREPLY:
-               ND_TCHECK_4(dp->icmp_mask);
-               (void)nd_snprintf(buf, sizeof(buf), "address mask is 0x%08x",
+               (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
                    GET_BE_U_4(dp->icmp_mask));
                break;
 
        case ICMP_TSTAMP:
-               ND_TCHECK_2(dp->icmp_seq);
-               (void)nd_snprintf(buf, sizeof(buf),
+               (void)snprintf(buf, sizeof(buf),
                    "time stamp query id %u seq %u",
                    GET_BE_U_2(dp->icmp_id),
                    GET_BE_U_2(dp->icmp_seq));
@@ -622,15 +612,15 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
 
        case ICMP_TSTAMPREPLY:
                ND_TCHECK_4(dp->icmp_ttime);
-               (void)nd_snprintf(buf, sizeof(buf),
+               (void)snprintf(buf, sizeof(buf),
                    "time stamp reply id %u seq %u: org %s",
                                GET_BE_U_2(dp->icmp_id),
                                GET_BE_U_2(dp->icmp_seq),
                                icmp_tstamp_print(GET_BE_U_4(dp->icmp_otime)));
 
-                (void)nd_snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
+                (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
                          icmp_tstamp_print(GET_BE_U_4(dp->icmp_rtime)));
-                (void)nd_snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
+                (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
                          icmp_tstamp_print(GET_BE_U_4(dp->icmp_ttime)));
                 break;
 
@@ -657,16 +647,28 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
 
         /*
          * print the remnants of the IP packet.
-         * save the snaplength as this may get overidden in the IP printer.
+         * save the snaplength as this may get overridden in the IP printer.
          */
        if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {
+               const u_char *snapend_save;
+
                bp += 8;
                ND_PRINT("\n\t");
                ip = (const struct ip *)bp;
-                snapend_save = ndo->ndo_snapend;
-               ND_TCHECK_2(ip->ip_len);
+               snapend_save = ndo->ndo_snapend;
+               /*
+                * Update the snapend because extensions (MPLS, ...) may be
+                * present after the IP packet. In this case the current
+                * (outer) packet's snapend is not what ip_print() needs to
+                * decode an IP packet nested in the middle of an ICMP payload.
+                *
+                * This prevents that, in ip_print(), for the nested IP packet,
+                * the remaining length < remaining caplen.
+                */
+               ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len),
+                                         ndo->ndo_snapend);
                ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));
-                ndo->ndo_snapend = snapend_save;
+               ndo->ndo_snapend = snapend_save;
        }
 
        /* ndo_protocol reassignment after ip_print() call */
@@ -747,9 +749,8 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                 case 1:
                     switch(obj_ctype) {
                     case 1:
-                        ND_TCHECK_4(obj_tptr);
                         raw_label = GET_BE_U_4(obj_tptr);
-                        ND_PRINT("\n\t    label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label));
+                        ND_PRINT("\n\t    label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label));
                         if (MPLS_STACK(raw_label))
                             ND_PRINT(", [S]");
                         ND_PRINT(", ttl %u", MPLS_TTL(raw_label));