nexmon – Rev 1
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/*
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
* 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.
*/
#define NETDISSECT_REWORKED
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include <string.h>
#include "interface.h"
#include "addrtoname.h"
#include "extract.h" /* must come after interface.h */
#include "ip.h"
#include "ipproto.h"
static const char tstr[] = "[|ip]";
static const struct tok ip_option_values[] = {
{ IPOPT_EOL, "EOL" },
{ IPOPT_NOP, "NOP" },
{ IPOPT_TS, "timestamp" },
{ IPOPT_SECURITY, "security" },
{ IPOPT_RR, "RR" },
{ IPOPT_SSRR, "SSRR" },
{ IPOPT_LSRR, "LSRR" },
{ IPOPT_RA, "RA" },
{ IPOPT_RFC1393, "traceroute" },
{ 0, NULL }
};
/*
* print the recorded route in an IP RR, LSRR or SSRR option.
*/
static void
ip_printroute(netdissect_options *ndo,
register const u_char *cp, u_int length)
{
register u_int ptr;
register u_int len;
if (length < 3) {
ND_PRINT((ndo, " [bad length %u]", length));
return;
}
if ((length + 1) & 3)
ND_PRINT((ndo, " [bad length %u]", length));
ptr = cp[2] - 1;
if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
ND_PRINT((ndo, " [bad ptr %u]", cp[2]));
for (len = 3; len < length; len += 4) {
ND_PRINT((ndo, " %s", ipaddr_string(ndo, &cp[len])));
if (ptr > len)
ND_PRINT((ndo, ","));
}
}
/*
* If source-routing is present and valid, return the final destination.
* Otherwise, return IP destination.
*
* This is used for UDP and TCP pseudo-header in the checksum
* calculation.
*/
static uint32_t
ip_finddst(netdissect_options *ndo,
const struct ip *ip)
{
int length;
int len;
const u_char *cp;
uint32_t retval;
cp = (const u_char *)(ip + 1);
length = (IP_HL(ip) << 2) - sizeof(struct ip);
for (; length > 0; cp += len, length -= len) {
int tt;
ND_TCHECK(*cp);
tt = *cp;
if (tt == IPOPT_EOL)
break;
else if (tt == IPOPT_NOP)
len = 1;
else {
ND_TCHECK(cp[1]);
len = cp[1];
if (len < 2)
break;
}
ND_TCHECK2(*cp, len);
switch (tt) {
case IPOPT_SSRR:
case IPOPT_LSRR:
if (len < 7)
break;
UNALIGNED_MEMCPY(&retval, cp + len - 4, 4);
return retval;
}
}
trunc:
UNALIGNED_MEMCPY(&retval, &ip->ip_dst.s_addr, sizeof(uint32_t));
return retval;
}
/*
* Compute a V4-style checksum by building a pseudoheader.
*/
int
nextproto4_cksum(netdissect_options *ndo,
const struct ip *ip, const uint8_t *data,
u_int len, u_int covlen, u_int next_proto)
{
struct phdr {
uint32_t src;
uint32_t dst;
u_char mbz;
u_char proto;
uint16_t len;
} ph;
struct cksum_vec vec[2];
/* pseudo-header.. */
ph.len = htons((uint16_t)len);
ph.mbz = 0;
ph.proto = next_proto;
UNALIGNED_MEMCPY(&ph.src, &ip->ip_src.s_addr, sizeof(uint32_t));
if (IP_HL(ip) == 5)
UNALIGNED_MEMCPY(&ph.dst, &ip->ip_dst.s_addr, sizeof(uint32_t));
else
ph.dst = ip_finddst(ndo, ip);
vec[0].ptr = (const uint8_t *)(void *)&ph;
vec[0].len = sizeof(ph);
vec[1].ptr = data;
vec[1].len = covlen;
return (in_cksum(vec, 2));
}
static void
ip_printts(netdissect_options *ndo,
register const u_char *cp, u_int length)
{
register u_int ptr;
register u_int len;
int hoplen;
const char *type;
if (length < 4) {
ND_PRINT((ndo, "[bad length %u]", length));
return;
}
ND_PRINT((ndo, " TS{"));
hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
if ((length - 4) & (hoplen-1))
ND_PRINT((ndo, "[bad length %u]", length));
ptr = cp[2] - 1;
len = 0;
if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
ND_PRINT((ndo, "[bad ptr %u]", cp[2]));
switch (cp[3]&0xF) {
case IPOPT_TS_TSONLY:
ND_PRINT((ndo, "TSONLY"));
break;
case IPOPT_TS_TSANDADDR:
ND_PRINT((ndo, "TS+ADDR"));
break;
/*
* prespecified should really be 3, but some ones might send 2
* instead, and the IPOPT_TS_PRESPEC constant can apparently
* have both values, so we have to hard-code it here.
*/
case 2:
ND_PRINT((ndo, "PRESPEC2.0"));
break;
case 3: /* IPOPT_TS_PRESPEC */
ND_PRINT((ndo, "PRESPEC"));
break;
default:
ND_PRINT((ndo, "[bad ts type %d]", cp[3]&0xF));
goto done;
}
type = " ";
for (len = 4; len < length; len += hoplen) {
if (ptr == len)
type = " ^ ";
ND_PRINT((ndo, "%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
hoplen!=8 ? "" : ipaddr_string(ndo, &cp[len])));
type = " ";
}
done:
ND_PRINT((ndo, "%s", ptr == len ? " ^ " : ""));
if (cp[3]>>4)
ND_PRINT((ndo, " [%d hops not recorded]} ", cp[3]>>4));
else
ND_PRINT((ndo, "}"));
}
/*
* print IP options.
*/
static void
ip_optprint(netdissect_options *ndo,
register const u_char *cp, u_int length)
{
register u_int option_len;
const char *sep = "";
for (; length > 0; cp += option_len, length -= option_len) {
u_int option_code;
ND_PRINT((ndo, "%s", sep));
sep = ",";
ND_TCHECK(*cp);
option_code = *cp;
ND_PRINT((ndo, "%s",
tok2str(ip_option_values,"unknown %u",option_code)));
if (option_code == IPOPT_NOP ||
option_code == IPOPT_EOL)
option_len = 1;
else {
ND_TCHECK(cp[1]);
option_len = cp[1];
if (option_len < 2) {
ND_PRINT((ndo, " [bad length %u]", option_len));
return;
}
}
if (option_len > length) {
ND_PRINT((ndo, " [bad length %u]", option_len));
return;
}
ND_TCHECK2(*cp, option_len);
switch (option_code) {
case IPOPT_EOL:
return;
case IPOPT_TS:
ip_printts(ndo, cp, option_len);
break;
case IPOPT_RR: /* fall through */
case IPOPT_SSRR:
case IPOPT_LSRR:
ip_printroute(ndo, cp, option_len);
break;
case IPOPT_RA:
if (option_len < 4) {
ND_PRINT((ndo, " [bad length %u]", option_len));
break;
}
ND_TCHECK(cp[3]);
if (EXTRACT_16BITS(&cp[2]) != 0)
ND_PRINT((ndo, " value %u", EXTRACT_16BITS(&cp[2])));
break;
case IPOPT_NOP: /* nothing to print - fall through */
case IPOPT_SECURITY:
default:
break;
}
}
return;
trunc:
ND_PRINT((ndo, "%s", tstr));
}
#define IP_RES 0x8000
static const struct tok ip_frag_values[] = {
{ IP_MF, "+" },
{ IP_DF, "DF" },
{ IP_RES, "rsvd" }, /* The RFC3514 evil ;-) bit */
{ 0, NULL }
};
struct ip_print_demux_state {
const struct ip *ip;
const u_char *cp;
u_int len, off;
u_char nh;
int advance;
};
static void
ip_print_demux(netdissect_options *ndo,
struct ip_print_demux_state *ipds)
{
struct protoent *proto;
struct cksum_vec vec[1];
again:
switch (ipds->nh) {
case IPPROTO_AH:
ipds->nh = *ipds->cp;
ipds->advance = ah_print(ndo, ipds->cp);
if (ipds->advance <= 0)
break;
ipds->cp += ipds->advance;
ipds->len -= ipds->advance;
goto again;
case IPPROTO_ESP:
{
int enh, padlen;
ipds->advance = esp_print(ndo, ipds->cp, ipds->len,
(const u_char *)ipds->ip,
&enh, &padlen);
if (ipds->advance <= 0)
break;
ipds->cp += ipds->advance;
ipds->len -= ipds->advance + padlen;
ipds->nh = enh & 0xff;
goto again;
}
case IPPROTO_IPCOMP:
{
int enh;
ipds->advance = ipcomp_print(ndo, ipds->cp, &enh);
if (ipds->advance <= 0)
break;
ipds->cp += ipds->advance;
ipds->len -= ipds->advance;
ipds->nh = enh & 0xff;
goto again;
}
case IPPROTO_SCTP:
sctp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
break;
case IPPROTO_DCCP:
dccp_print(ndo, ipds->cp, (const u_char *)ipds->ip, ipds->len);
break;
case IPPROTO_TCP:
/* pass on the MF bit plus the offset to detect fragments */
tcp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
ipds->off & (IP_MF|IP_OFFMASK));
break;
case IPPROTO_UDP:
/* pass on the MF bit plus the offset to detect fragments */
udp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
ipds->off & (IP_MF|IP_OFFMASK));
break;
case IPPROTO_ICMP:
/* pass on the MF bit plus the offset to detect fragments */
icmp_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip,
ipds->off & (IP_MF|IP_OFFMASK));
break;
case IPPROTO_PIGP:
/*
* XXX - the current IANA protocol number assignments
* page lists 9 as "any private interior gateway
* (used by Cisco for their IGRP)" and 88 as
* "EIGRP" from Cisco.
*
* Recent BSD <netinet/in.h> headers define
* IP_PROTO_PIGP as 9 and IP_PROTO_IGRP as 88.
* We define IP_PROTO_PIGP as 9 and
* IP_PROTO_EIGRP as 88; those names better
* match was the current protocol number
* assignments say.
*/
igrp_print(ndo, ipds->cp, ipds->len);
break;
case IPPROTO_EIGRP:
eigrp_print(ndo, ipds->cp, ipds->len);
break;
case IPPROTO_ND:
ND_PRINT((ndo, " nd %d", ipds->len));
break;
case IPPROTO_EGP:
egp_print(ndo, ipds->cp, ipds->len);
break;
case IPPROTO_OSPF:
ospf_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
break;
case IPPROTO_IGMP:
igmp_print(ndo, ipds->cp, ipds->len);
break;
case IPPROTO_IPV4:
/* DVMRP multicast tunnel (ip-in-ip encapsulation) */
ip_print(ndo, ipds->cp, ipds->len);
if (! ndo->ndo_vflag) {
ND_PRINT((ndo, " (ipip-proto-4)"));
return;
}
break;
case IPPROTO_IPV6:
/* ip6-in-ip encapsulation */
ip6_print(ndo, ipds->cp, ipds->len);
break;
case IPPROTO_RSVP:
rsvp_print(ndo, ipds->cp, ipds->len);
break;
case IPPROTO_GRE:
/* do it */
gre_print(ndo, ipds->cp, ipds->len);
break;
case IPPROTO_MOBILE:
mobile_print(ndo, ipds->cp, ipds->len);
break;
case IPPROTO_PIM:
vec[0].ptr = ipds->cp;
vec[0].len = ipds->len;
pim_print(ndo, ipds->cp, ipds->len, in_cksum(vec, 1));
break;
case IPPROTO_VRRP:
if (ndo->ndo_packettype == PT_CARP) {
if (ndo->ndo_vflag)
ND_PRINT((ndo, "carp %s > %s: ",
ipaddr_string(ndo, &ipds->ip->ip_src),
ipaddr_string(ndo, &ipds->ip->ip_dst)));
carp_print(ndo, ipds->cp, ipds->len, ipds->ip->ip_ttl);
} else {
if (ndo->ndo_vflag)
ND_PRINT((ndo, "vrrp %s > %s: ",
ipaddr_string(ndo, &ipds->ip->ip_src),
ipaddr_string(ndo, &ipds->ip->ip_dst)));
vrrp_print(ndo, ipds->cp, ipds->len,
(const u_char *)ipds->ip, ipds->ip->ip_ttl);
}
break;
case IPPROTO_PGM:
pgm_print(ndo, ipds->cp, ipds->len, (const u_char *)ipds->ip);
break;
default:
if (ndo->ndo_nflag==0 && (proto = getprotobynumber(ipds->nh)) != NULL)
ND_PRINT((ndo, " %s", proto->p_name));
else
ND_PRINT((ndo, " ip-proto-%d", ipds->nh));
ND_PRINT((ndo, " %d", ipds->len));
break;
}
}
void
ip_print_inner(netdissect_options *ndo,
const u_char *bp,
u_int length, u_int nh,
const u_char *bp2)
{
struct ip_print_demux_state ipd;
ipd.ip = (const struct ip *)bp2;
ipd.cp = bp;
ipd.len = length;
ipd.off = 0;
ipd.nh = nh;
ipd.advance = 0;
ip_print_demux(ndo, &ipd);
}
/*
* print an IP datagram.
*/
void
ip_print(netdissect_options *ndo,
const u_char *bp,
u_int length)
{
struct ip_print_demux_state ipd;
struct ip_print_demux_state *ipds=&ipd;
const u_char *ipend;
u_int hlen;
struct cksum_vec vec[1];
uint16_t sum, ip_sum;
struct protoent *proto;
ipds->ip = (const struct ip *)bp;
ND_TCHECK(ipds->ip->ip_vhl);
if (IP_V(ipds->ip) != 4) { /* print version if != 4 */
if (IP_V(ipds->ip) == 6)
ND_PRINT((ndo, "IP6, wrong link-layer encapsulation "));
else
ND_PRINT((ndo, "IP%u ", IP_V(ipds->ip)));
}
else if (!ndo->ndo_eflag)
ND_PRINT((ndo, "IP "));
ND_TCHECK(*ipds->ip);
if (length < sizeof (struct ip)) {
ND_PRINT((ndo, "truncated-ip %u", length));
return;
}
hlen = IP_HL(ipds->ip) * 4;
if (hlen < sizeof (struct ip)) {
ND_PRINT((ndo, "bad-hlen %u", hlen));
return;
}
ipds->len = EXTRACT_16BITS(&ipds->ip->ip_len);
if (length < ipds->len)
ND_PRINT((ndo, "truncated-ip - %u bytes missing! ",
ipds->len - length));
if (ipds->len < hlen) {
#ifdef GUESS_TSO
if (ipds->len) {
ND_PRINT((ndo, "bad-len %u", ipds->len));
return;
}
else {
/* we guess that it is a TSO send */
ipds->len = length;
}
#else
ND_PRINT((ndo, "bad-len %u", ipds->len));
return;
#endif /* GUESS_TSO */
}
/*
* Cut off the snapshot length to the end of the IP payload.
*/
ipend = bp + ipds->len;
if (ipend < ndo->ndo_snapend)
ndo->ndo_snapend = ipend;
ipds->len -= hlen;
ipds->off = EXTRACT_16BITS(&ipds->ip->ip_off);
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "(tos 0x%x", (int)ipds->ip->ip_tos));
/* ECN bits */
if (ipds->ip->ip_tos & 0x03) {
switch (ipds->ip->ip_tos & 0x03) {
case 1:
ND_PRINT((ndo, ",ECT(1)"));
break;
case 2:
ND_PRINT((ndo, ",ECT(0)"));
break;
case 3:
ND_PRINT((ndo, ",CE"));
}
}
if (ipds->ip->ip_ttl >= 1)
ND_PRINT((ndo, ", ttl %u", ipds->ip->ip_ttl));
/*
* for the firewall guys, print id, offset.
* On all but the last stick a "+" in the flags portion.
* For unfragmented datagrams, note the don't fragment flag.
*/
ND_PRINT((ndo, ", id %u, offset %u, flags [%s], proto %s (%u)",
EXTRACT_16BITS(&ipds->ip->ip_id),
(ipds->off & 0x1fff) * 8,
bittok2str(ip_frag_values, "none", ipds->off&0xe000),
tok2str(ipproto_values,"unknown",ipds->ip->ip_p),
ipds->ip->ip_p));
ND_PRINT((ndo, ", length %u", EXTRACT_16BITS(&ipds->ip->ip_len)));
if ((hlen - sizeof(struct ip)) > 0) {
ND_PRINT((ndo, ", options ("));
ip_optprint(ndo, (u_char *)(ipds->ip + 1), hlen - sizeof(struct ip));
ND_PRINT((ndo, ")"));
}
if (!ndo->ndo_Kflag && (u_char *)ipds->ip + hlen <= ndo->ndo_snapend) {
vec[0].ptr = (const uint8_t *)(void *)ipds->ip;
vec[0].len = hlen;
sum = in_cksum(vec, 1);
if (sum != 0) {
ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum);
ND_PRINT((ndo, ", bad cksum %x (->%x)!", ip_sum,
in_cksum_shouldbe(ip_sum, sum)));
}
}
ND_PRINT((ndo, ")\n "));
}
/*
* If this is fragment zero, hand it to the next higher
* level protocol.
*/
if ((ipds->off & 0x1fff) == 0) {
ipds->cp = (const u_char *)ipds->ip + hlen;
ipds->nh = ipds->ip->ip_p;
if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP &&
ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) {
ND_PRINT((ndo, "%s > %s: ",
ipaddr_string(ndo, &ipds->ip->ip_src),
ipaddr_string(ndo, &ipds->ip->ip_dst)));
}
ip_print_demux(ndo, ipds);
} else {
/* Ultra quiet now means that all this stuff should be suppressed */
if (ndo->ndo_qflag > 1) return;
/*
* if this isn't the first frag, we're missing the
* next level protocol header. print the ip addr
* and the protocol.
*/
if (ipds->off & 0x1fff) {
ND_PRINT((ndo, "%s > %s:", ipaddr_string(ndo, &ipds->ip->ip_src),
ipaddr_string(ndo, &ipds->ip->ip_dst)));
if (!ndo->ndo_nflag && (proto = getprotobynumber(ipds->ip->ip_p)) != NULL)
ND_PRINT((ndo, " %s", proto->p_name));
else
ND_PRINT((ndo, " ip-proto-%d", ipds->ip->ip_p));
}
}
return;
trunc:
ND_PRINT((ndo, "%s", tstr));
return;
}
void
ipN_print(netdissect_options *ndo, register const u_char *bp, register u_int length)
{
struct ip hdr;
if (length < 4) {
ND_PRINT((ndo, "truncated-ip %d", length));
return;
}
memcpy (&hdr, bp, 4);
switch (IP_V(&hdr)) {
case 4:
ip_print (ndo, bp, length);
return;
case 6:
ip6_print (ndo, bp, length);
return;
default:
ND_PRINT((ndo, "unknown ip %d", IP_V(&hdr)));
return;
}
}
/*
* Local Variables:
* c-style: whitesmith
* c-basic-offset: 8
* End:
*/