/* * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994, 1995, 1996 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that: (1) source code distributions * retain the above copyright notice and this paragraph in its entirety, (2) * distributions including binary code include the above copyright notice and * this paragraph in its entirety in the documentation or other materials * provided with the distribution, and (3) all advertising materials mentioning * features or use of this software display the following acknowledgement: * ``This product includes software developed by the University of California, * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of * the University nor the names of its contributors may be used to endorse * or promote products derived from this software without specific prior * written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #include #ifndef lint __RCSID("$NetBSD: print-icmp.c,v 1.14 2024/09/02 16:15:31 christos Exp $"); #endif /* \summary: Internet Control Message Protocol (ICMP) printer */ #include #include "netdissect-stdinc.h" #include #include #include "netdissect.h" #include "addrtoname.h" #include "extract.h" #include "ip.h" #include "udp.h" #include "ipproto.h" #include "mpls.h" /* * Interface Control Message Protocol Definitions. * Per RFC 792, September 1981. */ /* * Structure of an icmp header. */ struct icmp { nd_uint8_t icmp_type; /* type of message, see below */ nd_uint8_t icmp_code; /* type sub code */ nd_uint16_t icmp_cksum; /* ones complement cksum of struct */ union { nd_uint8_t ih_pptr; /* ICMP_PARAMPROB */ nd_ipv4 ih_gwaddr; /* ICMP_REDIRECT */ struct ih_idseq { nd_uint16_t icd_id; nd_uint16_t icd_seq; } ih_idseq; nd_uint32_t ih_void; } icmp_hun; #define icmp_pptr icmp_hun.ih_pptr #define icmp_gwaddr icmp_hun.ih_gwaddr #define icmp_id icmp_hun.ih_idseq.icd_id #define icmp_seq icmp_hun.ih_idseq.icd_seq #define icmp_void icmp_hun.ih_void union { struct id_ts { nd_uint32_t its_otime; nd_uint32_t its_rtime; nd_uint32_t its_ttime; } id_ts; struct id_ip { struct ip idi_ip; /* options and then 64 bits of data */ } id_ip; nd_uint32_t id_mask; nd_byte id_data[1]; } icmp_dun; #define icmp_otime icmp_dun.id_ts.its_otime #define icmp_rtime icmp_dun.id_ts.its_rtime #define icmp_ttime icmp_dun.id_ts.its_ttime #define icmp_ip icmp_dun.id_ip.idi_ip #define icmp_mask icmp_dun.id_mask #define icmp_data icmp_dun.id_data } UNALIGNED; /* * Lower bounds on packet lengths for various types. * For the error advice packets must first insure that the * 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. */ #define ICMP_MINLEN 8 /* abs minimum */ #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */ #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */ #define ICMP_MASKLEN 12 /* address mask */ #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */ #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8) /* N.B.: must separately check that ip_hl >= 5 */ /* * Definition of type and code field values. */ #define ICMP_ECHOREPLY 0 /* echo reply */ #define ICMP_UNREACH 3 /* dest unreachable, codes: */ #define ICMP_UNREACH_NET 0 /* bad net */ #define ICMP_UNREACH_HOST 1 /* bad host */ #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */ #define ICMP_UNREACH_PORT 3 /* bad port */ #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */ #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */ #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */ #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */ #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */ #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */ #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */ #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */ #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */ #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */ #define ICMP_REDIRECT 5 /* shorter route, codes: */ #define ICMP_REDIRECT_NET 0 /* for network */ #define ICMP_REDIRECT_HOST 1 /* for host */ #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */ #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */ #define ICMP_ECHO 8 /* echo service */ #define ICMP_ROUTERADVERT 9 /* router advertisement */ #define ICMP_ROUTERSOLICIT 10 /* router solicitation */ #define ICMP_TIMXCEED 11 /* time exceeded, code: */ #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */ #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */ #define ICMP_PARAMPROB 12 /* ip header bad */ #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */ #define ICMP_TSTAMP 13 /* timestamp request */ #define ICMP_TSTAMPREPLY 14 /* timestamp reply */ #define ICMP_IREQ 15 /* information request */ #define ICMP_IREQREPLY 16 /* information reply */ #define ICMP_MASKREQ 17 /* address mask request */ #define ICMP_MASKREPLY 18 /* address mask reply */ #define ICMP_MAXTYPE 18 #define ICMP_ERRTYPE(type) \ ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \ (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \ (type) == ICMP_PARAMPROB) #define ICMP_MULTIPART_EXT_TYPE(type) \ ((type) == ICMP_UNREACH || \ (type) == ICMP_TIMXCEED || \ (type) == ICMP_PARAMPROB) /* rfc1700 */ #ifndef ICMP_UNREACH_NET_UNKNOWN #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */ #endif #ifndef ICMP_UNREACH_HOST_UNKNOWN #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */ #endif #ifndef ICMP_UNREACH_ISOLATED #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */ #endif #ifndef ICMP_UNREACH_NET_PROHIB #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */ #endif #ifndef ICMP_UNREACH_HOST_PROHIB #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */ #endif #ifndef ICMP_UNREACH_TOSNET #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */ #endif #ifndef ICMP_UNREACH_TOSHOST #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */ #endif /* rfc1716 */ #ifndef ICMP_UNREACH_FILTER_PROHIB #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */ #endif #ifndef ICMP_UNREACH_HOST_PRECEDENCE #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */ #endif #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */ #endif /* Most of the icmp types */ static const struct tok icmp2str[] = { { ICMP_ECHOREPLY, "echo reply" }, { ICMP_SOURCEQUENCH, "source quench" }, { ICMP_ECHO, "echo request" }, { ICMP_ROUTERSOLICIT, "router solicitation" }, { ICMP_TSTAMP, "time stamp request" }, { ICMP_TSTAMPREPLY, "time stamp reply" }, { ICMP_IREQ, "information request" }, { ICMP_IREQREPLY, "information reply" }, { ICMP_MASKREQ, "address mask request" }, { 0, NULL } }; /* rfc1191 */ struct mtu_discovery { nd_uint16_t unused; nd_uint16_t nexthopmtu; }; /* rfc1256 */ struct ih_rdiscovery { nd_uint8_t ird_addrnum; nd_uint8_t ird_addrsiz; nd_uint16_t ird_lifetime; }; struct id_rdiscovery { nd_uint32_t ird_addr; nd_uint32_t ird_pref; }; /* * RFC 4884 - Extended ICMP to Support Multi-Part Messages * * This is a general extension mechanism, based on the mechanism * in draft-bonica-icmp-mpls-02 ICMP Extensions for MultiProtocol * Label Switching. * * The Destination Unreachable, Time Exceeded * and Parameter Problem messages are slightly changed as per * the above RFC. A new Length field gets added to give * the caller an idea about the length of the piggybacked * IP packet before the extension header starts. * * The Length field represents length of the padded "original datagram" * field measured in 32-bit words. * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Type | Code | Checksum | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | unused | Length | unused | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Internet Header + leading octets of original datagram | * | | * | // | * | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct icmp_ext_t { nd_uint8_t icmp_type; nd_uint8_t icmp_code; nd_uint16_t icmp_checksum; nd_byte icmp_reserved; nd_uint8_t icmp_length; nd_byte icmp_reserved2[2]; nd_byte icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */ nd_byte icmp_ext_version_res[2]; nd_uint16_t icmp_ext_checksum; nd_byte icmp_ext_data[1]; }; /* * Extract version from the first octet of icmp_ext_version_res. */ #define ICMP_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) /* * Current version. */ #define ICMP_EXT_VERSION 2 /* * Extension object class numbers. * * Class 1 dates back to draft-bonica-icmp-mpls-02. */ /* rfc4950 */ #define MPLS_STACK_ENTRY_OBJECT_CLASS 1 struct icmp_multipart_ext_object_header_t { nd_uint16_t length; nd_uint8_t class_num; nd_uint8_t ctype; }; static const struct tok icmp_multipart_ext_obj_values[] = { { 1, "MPLS Stack Entry" }, { 2, "Interface Identification" }, { 0, NULL} }; /* prototypes */ const char *icmp_tstamp_print(u_int); /* print the milliseconds since midnight UTC */ const char * icmp_tstamp_print(u_int tstamp) { u_int msec,sec,min,hrs; static char buf[64]; msec = tstamp % 1000; sec = tstamp / 1000; min = sec / 60; sec -= min * 60; hrs = min / 60; min -= hrs * 60; snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec); return buf; } UNALIGNED_OK void icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2, int fragmented) { char *cp; const struct icmp *dp; uint8_t icmp_type, icmp_code; const struct icmp_ext_t *ext_dp; const struct ip *ip; const char *str; const struct ip *oip; uint8_t ip_proto; const struct udphdr *ouh; const uint8_t *obj_tptr; uint32_t raw_label; const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header; u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype; uint16_t dport; char buf[MAXHOSTNAMELEN + 100]; struct cksum_vec vec[1]; ndo->ndo_protocol = "icmp"; dp = (const struct icmp *)bp; ext_dp = (const struct icmp_ext_t *)bp; ip = (const struct ip *)bp2; str = buf; 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: (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u", icmp_type == ICMP_ECHO ? "request" : "reply", GET_BE_U_2(dp->icmp_id), GET_BE_U_2(dp->icmp_seq)); break; case ICMP_UNREACH: switch (icmp_code) { case ICMP_UNREACH_NET: (void)snprintf(buf, sizeof(buf), "net %s unreachable", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_HOST: (void)snprintf(buf, sizeof(buf), "host %s unreachable", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_PROTOCOL: (void)snprintf(buf, sizeof(buf), "%s protocol %u unreachable", GET_IPADDR_STRING(dp->icmp_ip.ip_dst), GET_U_1(dp->icmp_ip.ip_p)); break; case ICMP_UNREACH_PORT: ND_TCHECK_1(dp->icmp_ip.ip_p); oip = &dp->icmp_ip; hlen = IP_HL(oip) * 4; ouh = (const struct udphdr *)(((const u_char *)oip) + hlen); dport = GET_BE_U_2(ouh->uh_dport); ip_proto = GET_U_1(oip->ip_p); switch (ip_proto) { case IPPROTO_TCP: (void)snprintf(buf, sizeof(buf), "%s tcp port %s unreachable", GET_IPADDR_STRING(oip->ip_dst), tcpport_string(ndo, dport)); break; case IPPROTO_UDP: (void)snprintf(buf, sizeof(buf), "%s udp port %s unreachable", GET_IPADDR_STRING(oip->ip_dst), udpport_string(ndo, dport)); break; default: (void)snprintf(buf, sizeof(buf), "%s protocol %u port %u unreachable", GET_IPADDR_STRING(oip->ip_dst), ip_proto, dport); break; } break; case ICMP_UNREACH_NEEDFRAG: { const struct mtu_discovery *mp; mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void; mtu = GET_BE_U_2(mp->nexthopmtu); if (mtu) { (void)snprintf(buf, sizeof(buf), "%s unreachable - need to frag (mtu %u)", GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu); } else { (void)snprintf(buf, sizeof(buf), "%s unreachable - need to frag", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); } } break; case ICMP_UNREACH_SRCFAIL: (void)snprintf(buf, sizeof(buf), "%s unreachable - source route failed", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_NET_UNKNOWN: (void)snprintf(buf, sizeof(buf), "net %s unreachable - unknown", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_HOST_UNKNOWN: (void)snprintf(buf, sizeof(buf), "host %s unreachable - unknown", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_ISOLATED: (void)snprintf(buf, sizeof(buf), "%s unreachable - source host isolated", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_NET_PROHIB: (void)snprintf(buf, sizeof(buf), "net %s unreachable - admin prohibited", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_HOST_PROHIB: (void)snprintf(buf, sizeof(buf), "host %s unreachable - admin prohibited", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_TOSNET: (void)snprintf(buf, sizeof(buf), "net %s unreachable - tos prohibited", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_TOSHOST: (void)snprintf(buf, sizeof(buf), "host %s unreachable - tos prohibited", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_FILTER_PROHIB: (void)snprintf(buf, sizeof(buf), "host %s unreachable - admin prohibited filter", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_HOST_PRECEDENCE: (void)snprintf(buf, sizeof(buf), "host %s unreachable - host precedence violation", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; case ICMP_UNREACH_PRECEDENCE_CUTOFF: (void)snprintf(buf, sizeof(buf), "host %s unreachable - precedence cutoff", GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); break; default: (void)snprintf(buf, sizeof(buf), "%s unreachable - #%u", GET_IPADDR_STRING(dp->icmp_ip.ip_dst), icmp_code); break; } break; case ICMP_REDIRECT: switch (icmp_code) { case ICMP_REDIRECT_NET: (void)snprintf(buf, sizeof(buf), "redirect %s to net %s", GET_IPADDR_STRING(dp->icmp_ip.ip_dst), GET_IPADDR_STRING(dp->icmp_gwaddr)); break; case ICMP_REDIRECT_HOST: (void)snprintf(buf, sizeof(buf), "redirect %s to host %s", GET_IPADDR_STRING(dp->icmp_ip.ip_dst), GET_IPADDR_STRING(dp->icmp_gwaddr)); break; case ICMP_REDIRECT_TOSNET: (void)snprintf(buf, sizeof(buf), "redirect-tos %s to net %s", GET_IPADDR_STRING(dp->icmp_ip.ip_dst), GET_IPADDR_STRING(dp->icmp_gwaddr)); break; case ICMP_REDIRECT_TOSHOST: (void)snprintf(buf, sizeof(buf), "redirect-tos %s to host %s", GET_IPADDR_STRING(dp->icmp_ip.ip_dst), GET_IPADDR_STRING(dp->icmp_gwaddr)); break; default: (void)snprintf(buf, sizeof(buf), "redirect-#%u %s to %s", icmp_code, GET_IPADDR_STRING(dp->icmp_ip.ip_dst), GET_IPADDR_STRING(dp->icmp_gwaddr)); break; } break; case ICMP_ROUTERADVERT: { const struct ih_rdiscovery *ihp; const struct id_rdiscovery *idp; u_int lifetime, num, size; (void)snprintf(buf, sizeof(buf), "router advertisement"); cp = buf + strlen(buf); ihp = (const struct ih_rdiscovery *)&dp->icmp_void; ND_TCHECK_SIZE(ihp); (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); cp = buf + strlen(buf); lifetime = GET_BE_U_2(ihp->ird_lifetime); if (lifetime < 60) { (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u", lifetime); } else if (lifetime < 60 * 60) { (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u", lifetime / 60, lifetime % 60); } else { (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u:%02u", lifetime / 3600, (lifetime % 3600) / 60, lifetime % 60); } cp = buf + strlen(buf); num = GET_U_1(ihp->ird_addrnum); (void)snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num); cp = buf + strlen(buf); size = GET_U_1(ihp->ird_addrsiz); if (size != 2) { (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)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; num--; } } break; case ICMP_TIMXCEED: ND_TCHECK_4(dp->icmp_ip.ip_dst); switch (icmp_code) { case ICMP_TIMXCEED_INTRANS: str = "time exceeded in-transit"; break; case ICMP_TIMXCEED_REASS: str = "ip reassembly time exceeded"; break; default: (void)snprintf(buf, sizeof(buf), "time exceeded-#%u", icmp_code); break; } break; case ICMP_PARAMPROB: if (icmp_code) (void)snprintf(buf, sizeof(buf), "parameter problem - code %u", icmp_code); else { (void)snprintf(buf, sizeof(buf), "parameter problem - octet %u", GET_U_1(dp->icmp_pptr)); } break; case ICMP_MASKREPLY: (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x", GET_BE_U_4(dp->icmp_mask)); break; case ICMP_TSTAMP: (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)); break; case ICMP_TSTAMPREPLY: ND_TCHECK_4(dp->icmp_ttime); (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)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s", icmp_tstamp_print(GET_BE_U_4(dp->icmp_rtime))); (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s", icmp_tstamp_print(GET_BE_U_4(dp->icmp_ttime))); break; default: str = tok2str(icmp2str, "type-#%u", icmp_type); break; } ND_PRINT("ICMP %s, length %u", str, plen); if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */ if (ND_TTEST_LEN(bp, plen)) { uint16_t sum; vec[0].ptr = (const uint8_t *)(const void *)dp; vec[0].len = plen; sum = in_cksum(vec, 1); if (sum != 0) { uint16_t icmp_sum = GET_BE_U_2(dp->icmp_cksum); ND_PRINT(" (wrong icmp cksum %x (->%x)!)", icmp_sum, in_cksum_shouldbe(icmp_sum, sum)); } } } /* * print the remnants of the IP packet. * 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; /* * 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_protocol reassignment after ip_print() call */ ndo->ndo_protocol = "icmp"; /* * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types. */ if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) { ND_TCHECK_SIZE(ext_dp); /* * Check first if the multi-part extension header shows a non-zero length. * If the length field is not set then silently verify the checksum * to check if an extension header is present. This is expedient, * however not all implementations set the length field proper. */ if (GET_U_1(ext_dp->icmp_length) == 0 && ND_TTEST_LEN(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) { vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res; vec[0].len = plen - ICMP_EXTD_MINLEN; if (in_cksum(vec, 1)) { return; } } ND_PRINT("\n\tICMP Multi-Part extension v%u", ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))); /* * Sanity checking of the header. */ if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != ICMP_EXT_VERSION) { ND_PRINT(" packet not supported"); return; } hlen = plen - ICMP_EXTD_MINLEN; if (ND_TTEST_LEN(ext_dp->icmp_ext_version_res, hlen)) { vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res; vec[0].len = hlen; ND_PRINT(", checksum 0x%04x (%scorrect), length %u", GET_BE_U_2(ext_dp->icmp_ext_checksum), in_cksum(vec, 1) ? "in" : "", hlen); } hlen -= 4; /* subtract common header size */ obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data; while (hlen > sizeof(struct icmp_multipart_ext_object_header_t)) { icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr; ND_TCHECK_SIZE(icmp_multipart_ext_object_header); obj_tlen = GET_BE_U_2(icmp_multipart_ext_object_header->length); obj_class_num = GET_U_1(icmp_multipart_ext_object_header->class_num); obj_ctype = GET_U_1(icmp_multipart_ext_object_header->ctype); obj_tptr += sizeof(struct icmp_multipart_ext_object_header_t); ND_PRINT("\n\t %s Object (%u), Class-Type: %u, length %u", tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num), obj_class_num, obj_ctype, obj_tlen); hlen-=sizeof(struct icmp_multipart_ext_object_header_t); /* length field includes tlv header */ /* infinite loop protection */ if ((obj_class_num == 0) || (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) { return; } obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t); switch (obj_class_num) { case MPLS_STACK_ENTRY_OBJECT_CLASS: switch(obj_ctype) { case 1: raw_label = GET_BE_U_4(obj_tptr); 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)); break; default: print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); } break; default: print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); break; } if (hlen < obj_tlen) break; hlen -= obj_tlen; obj_tptr += obj_tlen; } } return; trunc: nd_print_trunc(ndo); }