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tcpdump/print-icmp.c
Guy Harris 0a515812de Don't set ndo_snaplen, either. 
It's *not* the length of the captured data in the packet, it's the
snapshot length for the live capture or the savefile - the length of the
captured data in the packet could be less.
2017-06-02 20:10:49 -07:00

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/*
* 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.
*/
/* \summary: Internet Control Message Protocol (ICMP) printer */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <netdissect-stdinc.h>
#include <stdio.h>
#include <string.h>
#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 {
uint8_t icmp_type; /* type of message, see below */
uint8_t icmp_code; /* type sub code */
uint16_t icmp_cksum; /* ones complement cksum of struct */
union {
uint8_t ih_pptr; /* ICMP_PARAMPROB */
struct in_addr ih_gwaddr; /* ICMP_REDIRECT */
struct ih_idseq {
uint16_t icd_id;
uint16_t icd_seq;
} ih_idseq;
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 {
uint32_t its_otime;
uint32_t its_rtime;
uint32_t its_ttime;
} id_ts;
struct id_ip {
struct ip idi_ip;
/* options and then 64 bits of data */
} id_ip;
uint32_t id_mask;
uint8_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 (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_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 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 }
};
/* Formats for most of the ICMP_UNREACH codes */
static const 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 const 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 {
uint16_t unused;
uint16_t nexthopmtu;
};
/* rfc1256 */
struct ih_rdiscovery {
uint8_t ird_addrnum;
uint8_t ird_addrsiz;
uint16_t ird_lifetime;
};
struct id_rdiscovery {
uint32_t ird_addr;
uint32_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 {
uint8_t icmp_type;
uint8_t icmp_code;
uint8_t icmp_checksum[2];
uint8_t icmp_reserved;
uint8_t icmp_length;
uint8_t icmp_reserved2[2];
uint8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
uint8_t icmp_ext_version_res[2];
uint8_t icmp_ext_checksum[2];
uint8_t icmp_ext_data[1];
};
struct icmp_mpls_ext_object_header_t {
uint8_t length[2];
uint8_t class_num;
uint8_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(netdissect_options *ndo, 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 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, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
char buf[MAXHOSTNAMELEN + 100];
struct cksum_vec vec[1];
dp = (const struct icmp *)bp;
ext_dp = (const struct icmp_ext_t *)bp;
ip = (const struct ip *)bp2;
str = buf;
ND_TCHECK(dp->icmp_code);
switch (dp->icmp_type) {
case ICMP_ECHO:
case ICMP_ECHOREPLY:
ND_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:
ND_TCHECK(dp->icmp_ip.ip_dst);
switch (dp->icmp_code) {
case ICMP_UNREACH_PROTOCOL:
ND_TCHECK(dp->icmp_ip.ip_p);
(void)snprintf(buf, sizeof(buf),
"%s protocol %d unreachable",
ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
dp->icmp_ip.ip_p);
break;
case ICMP_UNREACH_PORT:
ND_TCHECK(dp->icmp_ip.ip_p);
oip = &dp->icmp_ip;
hlen = IP_HL(oip) * 4;
ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
ND_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(ndo, &oip->ip_dst),
tcpport_string(ndo, dport));
break;
case IPPROTO_UDP:
(void)snprintf(buf, sizeof(buf),
"%s udp port %s unreachable",
ipaddr_string(ndo, &oip->ip_dst),
udpport_string(ndo, dport));
break;
default:
(void)snprintf(buf, sizeof(buf),
"%s protocol %d port %d unreachable",
ipaddr_string(ndo, &oip->ip_dst),
oip->ip_p, dport);
break;
}
break;
case ICMP_UNREACH_NEEDFRAG:
{
register const struct mtu_discovery *mp;
mp = (const struct mtu_discovery *)(const 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(ndo, &dp->icmp_ip.ip_dst), mtu);
} else {
(void)snprintf(buf, sizeof(buf),
"%s unreachable - need to frag",
ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
}
}
break;
default:
fmt = tok2str(unreach2str, "#%d %%s unreachable",
dp->icmp_code);
(void)snprintf(buf, sizeof(buf), fmt,
ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
break;
}
break;
case ICMP_REDIRECT:
ND_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(ndo, &dp->icmp_ip.ip_dst),
ipaddr_string(ndo, &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 = (const struct ih_rdiscovery *)&dp->icmp_void;
ND_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 = (const struct id_rdiscovery *)&dp->icmp_data;
while (num-- > 0) {
ND_TCHECK(*idp);
(void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
ipaddr_string(ndo, &idp->ird_addr),
EXTRACT_32BITS(&idp->ird_pref));
cp = buf + strlen(buf);
++idp;
}
}
break;
case ICMP_TIMXCEED:
ND_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 {
ND_TCHECK(dp->icmp_pptr);
(void)snprintf(buf, sizeof(buf),
"parameter problem - octet %d", dp->icmp_pptr);
}
break;
case ICMP_MASKREPLY:
ND_TCHECK(dp->icmp_mask);
(void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
EXTRACT_32BITS(&dp->icmp_mask));
break;
case ICMP_TSTAMP:
ND_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:
ND_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;
}
ND_PRINT((ndo, "ICMP %s, length %u", str, plen));
if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
uint16_t sum, icmp_sum;
if (ND_TTEST2(*bp, plen)) {
vec[0].ptr = (const uint8_t *)(const void *)dp;
vec[0].len = plen;
sum = in_cksum(vec, 1);
if (sum != 0) {
icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
ND_PRINT((ndo, " (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 (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(dp->icmp_type)) {
bp += 8;
ND_PRINT((ndo, "\n\t"));
ip = (const struct ip *)bp;
snapend_save = ndo->ndo_snapend;
ip_print(ndo, bp, EXTRACT_16BITS(&ip->ip_len));
ndo->ndo_snapend = snapend_save;
}
/*
* Attempt to decode the MPLS extensions only for some ICMP types.
*/
if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) {
ND_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 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((ndo, "\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) {
ND_PRINT((ndo, " packet not supported"));
return;
}
hlen = plen - ICMP_EXTD_MINLEN;
vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
vec[0].len = hlen;
ND_PRINT((ndo, ", 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 = (const uint8_t *)ext_dp->icmp_ext_data;
while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
icmp_mpls_ext_object_header = (const struct icmp_mpls_ext_object_header_t *)obj_tptr;
ND_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);
ND_PRINT((ndo, "\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:
ND_TCHECK2(*obj_tptr, 4);
raw_label = EXTRACT_32BITS(obj_tptr);
ND_PRINT((ndo, "\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)));
if (MPLS_STACK(raw_label))
ND_PRINT((ndo, ", [S]"));
ND_PRINT((ndo, ", ttl %u", MPLS_TTL(raw_label)));
break;
default:
print_unknown_data(ndo, 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(ndo, obj_tptr, "\n\t ", obj_tlen);
break;
}
if (hlen < obj_tlen)
break;
hlen -= obj_tlen;
obj_tptr += obj_tlen;
}
}
return;
trunc:
ND_PRINT((ndo, "[|icmp]"));
}
/*
* Local Variables:
* c-style: whitesmith
* c-basic-offset: 8
* End:
*/
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