diff options
Diffstat (limited to 'freebsd/contrib/tcpdump/print-icmp.c')
| -rw-r--r-- | freebsd/contrib/tcpdump/print-icmp.c | 699 |
1 files changed, 699 insertions, 0 deletions
diff --git a/freebsd/contrib/tcpdump/print-icmp.c b/freebsd/contrib/tcpdump/print-icmp.c new file mode 100644 index 00000000..8cdc3651 --- /dev/null +++ b/freebsd/contrib/tcpdump/print-icmp.c @@ -0,0 +1,699 @@ +#include <machine/rtems-bsd-user-space.h> + +/* + * 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. + * + * $FreeBSD$ + */ + +#ifndef lint +static const char rcsid[] _U_ = + "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.87 2007-09-13 17:42:31 guy Exp $ (LBL)"; +#endif + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <tcpdump-stdinc.h> + +#include <stdio.h> +#include <string.h> + +#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_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 { + 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; + 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_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-internet-icmp-08 */ +#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 || \ + (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 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-internet-icmp-08 + * + * The Destination Unreachable, Time Exceeded + * and Parameter Problem messages are slighly changed as per + * the above draft. A new Length field gets added to give + * the caller an idea about the length of the piggypacked + * IP packet before the MPLS 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 { + u_int8_t icmp_type; + u_int8_t icmp_code; + u_int8_t icmp_checksum[2]; + u_int8_t icmp_reserved; + u_int8_t icmp_length; + u_int8_t icmp_reserved2[2]; + u_int8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */ + u_int8_t icmp_ext_version_res[2]; + u_int8_t icmp_ext_checksum[2]; + u_int8_t icmp_ext_data[1]; +}; + +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} +}; + +/* 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; +} + +void +icmp_print(const u_char *bp, u_int plen, const u_char *bp2, int fragmented) +{ + char *cp; + const struct icmp *dp; + const struct icmp_ext_t *ext_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 u_char *snapend_save; + 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]; + struct cksum_vec vec[1]; + + dp = (struct icmp *)bp; + ext_dp = (struct icmp_ext_t *)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, id %u, seq %u", + dp->icmp_type == ICMP_ECHO ? + "request" : "reply", + EXTRACT_16BITS(&dp->icmp_id), + 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 *)(u_char *)&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 %s", + EXTRACT_16BITS(&dp->icmp_id), + EXTRACT_16BITS(&dp->icmp_seq), + icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime))); + + (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s", + icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime))); + (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s", + icmp_tstamp_print(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; + struct cksum_vec vec[1]; + if (TTEST2(*bp, plen)) { + vec[0].ptr = (const u_int8_t *)(void *)dp; + vec[0].len = plen; + sum = in_cksum(vec, 1); + 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)); + } + } + } + + /* + * print the remnants of the IP packet. + * save the snaplength as this may get overidden in the IP printer. + */ + if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) { + bp += 8; + (void)printf("\n\t"); + ip = (struct ip *)bp; + snaplen = snapend - bp; + snapend_save = snapend; + ip_print(gndo, bp, EXTRACT_16BITS(&ip->ip_len)); + snapend = snapend_save; + } + + /* + * Attempt to decode the MPLS extensions only for some ICMP types. + */ + if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) { + + TCHECK(*ext_dp); + + /* + * Check first if the mpls 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 (!ext_dp->icmp_length) { + vec[0].ptr = (const u_int8_t *)(void *)&ext_dp->icmp_ext_version_res; + vec[0].len = plen - ICMP_EXTD_MINLEN; + if (in_cksum(vec, 1)) { + return; + } + } + + printf("\n\tMPLS extension v%u", + ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))); + + /* + * Sanity checking of the header. + */ + if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != + ICMP_MPLS_EXT_VERSION) { + printf(" packet not supported"); + return; + } + + hlen = plen - ICMP_EXTD_MINLEN; + vec[0].ptr = (const u_int8_t *)(void *)&ext_dp->icmp_ext_version_res; + vec[0].len = hlen; + printf(", checksum 0x%04x (%scorrect), length %u", + EXTRACT_16BITS(ext_dp->icmp_ext_checksum), + in_cksum(vec, 1) ? "in" : "", + hlen); + + hlen -= 4; /* subtract common header size */ + obj_tptr = (u_int8_t *)ext_dp->icmp_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; + TCHECK(*icmp_mpls_ext_object_header); + 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 */ + + /* infinite loop protection */ + if ((obj_class_num == 0) || + (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) { + return; + } + obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t); + + switch (obj_class_num) { + case 1: + switch(obj_ctype) { + case 1: + TCHECK2(*obj_tptr, 4); + 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; + } + if (hlen < obj_tlen) + break; + hlen -= obj_tlen; + obj_tptr += obj_tlen; + } + } + + return; +trunc: + fputs("[|icmp]", stdout); +} |