/* * 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. */ #ifndef lint static const char rcsid[] _U_ = "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.79 2004-06-15 07:43:03 hannes Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include "interface.h" #include "addrtoname.h" #include "extract.h" /* must come after interface.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 { u_int8_t icmp_type; /* type of message, see below */ u_int8_t icmp_code; /* type sub code */ u_int16_t icmp_cksum; /* ones complement cksum of struct */ union { u_int8_t ih_pptr; /* ICMP_PARAMPROB */ struct in_addr ih_gwaddr; /* ICMP_REDIRECT */ struct ih_idseq { u_int16_t icd_id; u_int16_t icd_seq; } ih_idseq; u_int32_t ih_void; /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */ struct ih_pmtu { u_int16_t ipm_void; u_int16_t ipm_nextmtu; } ih_pmtu; } 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 #define icmp_pmvoid icmp_hun.ih_pmtu.ipm_void #define icmp_nextmtu icmp_hun.ih_pmtu.ipm_nextmtu union { struct id_ts { u_int32_t its_otime; u_int32_t its_rtime; u_int32_t its_ttime; } id_ts; struct id_ip { struct ip idi_ip; /* options and then 64 bits of data */ } id_ip; struct mpls_ext { u_int8_t legacy_header[128]; /* extension header starts 128 bytes after ICMP header */ u_int8_t version_res[2]; u_int8_t checksum[2]; u_int8_t data[1]; } mpls_ext; u_int32_t id_mask; u_int8_t 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 #define icmp_mpls_ext_version icmp_dun.mpls_ext.version_res #define icmp_mpls_ext_checksum icmp_dun.mpls_ext.checksum #define icmp_mpls_ext_data icmp_dun.mpls_ext.data }; #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) #define ICMP_MPLS_EXT_VERSION 2 /* * 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. * 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-icmp-mpls-02 */ #define ICMP_TSLEN (8 + 3 * sizeof (u_int32_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_INFOTYPE(type) \ ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \ (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \ (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \ (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \ (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY) #define ICMP_MPLS_EXT_TYPE(type) \ ((type) == ICMP_UNREACH || (type) == ICMP_TIMXCEED) /* 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 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 } }; /* Formats for most of the ICMP_UNREACH codes */ static struct tok unreach2str[] = { { ICMP_UNREACH_NET, "net %s unreachable" }, { ICMP_UNREACH_HOST, "host %s unreachable" }, { ICMP_UNREACH_SRCFAIL, "%s unreachable - source route failed" }, { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" }, { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" }, { ICMP_UNREACH_ISOLATED, "%s unreachable - source host isolated" }, { ICMP_UNREACH_NET_PROHIB, "net %s unreachable - admin prohibited" }, { ICMP_UNREACH_HOST_PROHIB, "host %s unreachable - admin prohibited" }, { ICMP_UNREACH_TOSNET, "net %s unreachable - tos prohibited" }, { ICMP_UNREACH_TOSHOST, "host %s unreachable - tos prohibited" }, { ICMP_UNREACH_FILTER_PROHIB, "host %s unreachable - admin prohibited filter" }, { ICMP_UNREACH_HOST_PRECEDENCE, "host %s unreachable - host precedence violation" }, { ICMP_UNREACH_PRECEDENCE_CUTOFF, "host %s unreachable - precedence cutoff" }, { 0, NULL } }; /* Formats for the ICMP_REDIRECT codes */ static struct tok type2str[] = { { ICMP_REDIRECT_NET, "redirect %s to net %s" }, { ICMP_REDIRECT_HOST, "redirect %s to host %s" }, { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" }, { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" }, { 0, NULL } }; /* rfc1191 */ struct mtu_discovery { u_int16_t unused; u_int16_t nexthopmtu; }; /* rfc1256 */ struct ih_rdiscovery { u_int8_t ird_addrnum; u_int8_t ird_addrsiz; u_int16_t ird_lifetime; }; struct id_rdiscovery { u_int32_t ird_addr; u_int32_t ird_pref; }; /* draft-bonica-icmp-mpls-02 */ struct icmp_mpls_ext_object_header_t { u_int8_t length[2]; u_int8_t class_num; u_int8_t ctype; }; static const struct tok icmp_mpls_ext_obj_values[] = { { 1, "MPLS Stack Entry" }, { 2, "Extended Payload" }, { 0, NULL} }; void icmp_print(const u_char *bp, u_int plen, const u_char *bp2, int fragmented) { char *cp; const struct icmp *dp; const struct ip *ip; const char *str, *fmt; const struct ip *oip; const struct udphdr *ouh; const u_int8_t *obj_tptr; u_int32_t raw_label; const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header; u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype; char buf[MAXHOSTNAMELEN + 100]; dp = (struct icmp *)bp; ip = (struct ip *)bp2; str = buf; TCHECK(dp->icmp_code); switch (dp->icmp_type) { case ICMP_ECHO: case ICMP_ECHOREPLY: TCHECK(dp->icmp_seq); (void)snprintf(buf, sizeof(buf), "echo %s seq %u", dp->icmp_type == ICMP_ECHO ? "request" : "reply", EXTRACT_16BITS(&dp->icmp_seq)); break; case ICMP_UNREACH: TCHECK(dp->icmp_ip.ip_dst); switch (dp->icmp_code) { case ICMP_UNREACH_PROTOCOL: TCHECK(dp->icmp_ip.ip_p); (void)snprintf(buf, sizeof(buf), "%s protocol %d unreachable", ipaddr_string(&dp->icmp_ip.ip_dst), dp->icmp_ip.ip_p); break; case ICMP_UNREACH_PORT: TCHECK(dp->icmp_ip.ip_p); oip = &dp->icmp_ip; hlen = IP_HL(oip) * 4; ouh = (struct udphdr *)(((u_char *)oip) + hlen); TCHECK(ouh->uh_dport); dport = EXTRACT_16BITS(&ouh->uh_dport); switch (oip->ip_p) { case IPPROTO_TCP: (void)snprintf(buf, sizeof(buf), "%s tcp port %s unreachable", ipaddr_string(&oip->ip_dst), tcpport_string(dport)); break; case IPPROTO_UDP: (void)snprintf(buf, sizeof(buf), "%s udp port %s unreachable", ipaddr_string(&oip->ip_dst), udpport_string(dport)); break; default: (void)snprintf(buf, sizeof(buf), "%s protocol %d port %d unreachable", ipaddr_string(&oip->ip_dst), oip->ip_p, dport); break; } break; case ICMP_UNREACH_NEEDFRAG: { register const struct mtu_discovery *mp; mp = (struct mtu_discovery *)&dp->icmp_void; mtu = EXTRACT_16BITS(&mp->nexthopmtu); if (mtu) { (void)snprintf(buf, sizeof(buf), "%s unreachable - need to frag (mtu %d)", ipaddr_string(&dp->icmp_ip.ip_dst), mtu); } else { (void)snprintf(buf, sizeof(buf), "%s unreachable - need to frag", ipaddr_string(&dp->icmp_ip.ip_dst)); } } break; default: fmt = tok2str(unreach2str, "#%d %%s unreachable", dp->icmp_code); (void)snprintf(buf, sizeof(buf), fmt, ipaddr_string(&dp->icmp_ip.ip_dst)); break; } break; case ICMP_REDIRECT: TCHECK(dp->icmp_ip.ip_dst); fmt = tok2str(type2str, "redirect-#%d %%s to net %%s", dp->icmp_code); (void)snprintf(buf, sizeof(buf), fmt, ipaddr_string(&dp->icmp_ip.ip_dst), ipaddr_string(&dp->icmp_gwaddr)); break; case ICMP_ROUTERADVERT: { register const struct ih_rdiscovery *ihp; register const struct id_rdiscovery *idp; u_int lifetime, num, size; (void)snprintf(buf, sizeof(buf), "router advertisement"); cp = buf + strlen(buf); ihp = (struct ih_rdiscovery *)&dp->icmp_void; TCHECK(*ihp); (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); cp = buf + strlen(buf); lifetime = EXTRACT_16BITS(&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 = ihp->ird_addrnum; (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num); cp = buf + strlen(buf); size = ihp->ird_addrsiz; if (size != 2) { (void)snprintf(cp, sizeof(buf) - (cp - buf), " [size %d]", size); break; } idp = (struct id_rdiscovery *)&dp->icmp_data; while (num-- > 0) { TCHECK(*idp); (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}", ipaddr_string(&idp->ird_addr), EXTRACT_32BITS(&idp->ird_pref)); cp = buf + strlen(buf); ++idp; } } break; case ICMP_TIMXCEED: TCHECK(dp->icmp_ip.ip_dst); switch (dp->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-#%d", dp->icmp_code); break; } break; case ICMP_PARAMPROB: if (dp->icmp_code) (void)snprintf(buf, sizeof(buf), "parameter problem - code %d", dp->icmp_code); else { TCHECK(dp->icmp_pptr); (void)snprintf(buf, sizeof(buf), "parameter problem - octet %d", dp->icmp_pptr); } break; case ICMP_MASKREPLY: TCHECK(dp->icmp_mask); (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x", EXTRACT_32BITS(&dp->icmp_mask)); break; case ICMP_TSTAMP: TCHECK(dp->icmp_seq); (void)snprintf(buf, sizeof(buf), "time stamp query id %u seq %u", EXTRACT_16BITS(&dp->icmp_id), EXTRACT_16BITS(&dp->icmp_seq)); break; case ICMP_TSTAMPREPLY: TCHECK(dp->icmp_ttime); (void)snprintf(buf, sizeof(buf), "time stamp reply id %u seq %u : org 0x%x recv 0x%x xmit 0x%x", EXTRACT_16BITS(&dp->icmp_id), EXTRACT_16BITS(&dp->icmp_seq), EXTRACT_32BITS(&dp->icmp_otime), EXTRACT_32BITS(&dp->icmp_rtime), EXTRACT_32BITS(&dp->icmp_ttime)); break; default: str = tok2str(icmp2str, "type-#%d", dp->icmp_type); break; } (void)printf("ICMP %s, length %u", str, plen); if (vflag && !fragmented) { /* don't attempt checksumming if this is a frag */ u_int16_t sum, icmp_sum; if (TTEST2(*bp, plen)) { sum = in_cksum((u_short*)dp, plen, 0); if (sum != 0) { icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum); (void)printf(" (wrong icmp cksum %x (->%x)!)", icmp_sum, in_cksum_shouldbe(icmp_sum, sum)); } } } if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) { bp += 8; (void)printf("\n\t"); ip = (struct ip *)bp; snaplen = snapend - bp; ip_print(bp, EXTRACT_16BITS(&ip->ip_len)); } if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) { printf("\n\tMPLS extension v%u",ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version))); /* * Sanity checking of the header. */ if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version)) != ICMP_MPLS_EXT_VERSION) { printf(" packet not supported"); return; } hlen = plen - ICMP_EXTD_MINLEN; printf(", checksum 0x%04x (unverified), length %u", /* FIXME */ EXTRACT_16BITS(dp->icmp_mpls_ext_checksum), hlen); hlen -= 4; /* subtract common header size */ obj_tptr = (u_int8_t *)dp->icmp_mpls_ext_data; while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) { icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr; obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length); obj_class_num = icmp_mpls_ext_object_header->class_num; obj_ctype = icmp_mpls_ext_object_header->ctype; obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t); printf("\n\t %s Object (%u), Class-Type: %u, length %u", tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num), obj_class_num, obj_ctype, obj_tlen); hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */ obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t); switch (obj_class_num) { case 1: switch(obj_ctype) { case 1: raw_label = EXTRACT_32BITS(obj_tptr); printf("\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)); if (MPLS_STACK(raw_label)) printf(", [S]"); printf(", ttl %u", MPLS_TTL(raw_label)); break; default: print_unknown_data(obj_tptr, "\n\t ", obj_tlen); } break; /* * FIXME those are the defined objects that lack a decoder * you are welcome to contribute code ;-) */ case 2: default: print_unknown_data(obj_tptr, "\n\t ", obj_tlen); break; } hlen -= obj_tlen; obj_tptr += obj_tlen; } } return; trunc: fputs("[|icmp]", stdout); }