freebsd-dev/contrib/tcpdump/print-ip.c
Gleb Smirnoff ffe9c13e2a Provide ability for printing and decoding pfsync(4) traffic. This
doesn't mean supporting IFT_PFSYNC (which I hope will eventually
die). This means decoding packets with IP protocol of 240 caught
on any normal interface like Ethernet.

  The code is based on couple of files from OpenBSD, significantly
modified by myself.

  Parser differentiates for four levels of verbosity: no -v, -v,
-vv and -vvv.

  We don't yet forward this code upstream, because currently it
strongly relies on if_pfsync.h and even on pfvar.h. I hope that
this can be fixed in future.

Reviewed by:	gnn, delphij
2012-10-05 07:51:21 +00:00

712 lines
16 KiB
C

/*
* 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.
*
* $FreeBSD$
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.159 2007-09-14 01:29:28 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "addrtoname.h"
#include "interface.h"
#include "extract.h" /* must come after interface.h */
#include "ip.h"
#include "ipproto.h"
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(register const u_char *cp, u_int length)
{
register u_int ptr;
register u_int len;
if (length < 3) {
printf(" [bad length %u]", length);
return;
}
if ((length + 1) & 3)
printf(" [bad length %u]", length);
ptr = cp[2] - 1;
if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
printf(" [bad ptr %u]", cp[2]);
for (len = 3; len < length; len += 4) {
printf(" %s", ipaddr_string(&cp[len]));
if (ptr > len)
printf(",");
}
}
/*
* 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 u_int32_t
ip_finddst(const struct ip *ip)
{
int length;
int len;
const u_char *cp;
u_int32_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;
TCHECK(*cp);
tt = *cp;
if (tt == IPOPT_EOL)
break;
else if (tt == IPOPT_NOP)
len = 1;
else {
TCHECK(cp[1]);
len = cp[1];
if (len < 2)
break;
}
TCHECK2(*cp, len);
switch (tt) {
case IPOPT_SSRR:
case IPOPT_LSRR:
if (len < 7)
break;
memcpy(&retval, cp + len - 4, 4);
return retval;
}
}
trunc:
memcpy(&retval, &ip->ip_dst.s_addr, sizeof(u_int32_t));
return retval;
}
/*
* Compute a V4-style checksum by building a pseudoheader.
*/
int
nextproto4_cksum(const struct ip *ip, const u_int8_t *data,
u_int len, u_int next_proto)
{
struct phdr {
u_int32_t src;
u_int32_t dst;
u_char mbz;
u_char proto;
u_int16_t len;
} ph;
struct cksum_vec vec[2];
/* pseudo-header.. */
ph.len = htons((u_int16_t)len);
ph.mbz = 0;
ph.proto = next_proto;
memcpy(&ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
if (IP_HL(ip) == 5)
memcpy(&ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
else
ph.dst = ip_finddst(ip);
vec[0].ptr = (const u_int8_t *)(void *)&ph;
vec[0].len = sizeof(ph);
vec[1].ptr = data;
vec[1].len = len;
return (in_cksum(vec, 2));
}
static void
ip_printts(register const u_char *cp, u_int length)
{
register u_int ptr;
register u_int len;
int hoplen;
const char *type;
if (length < 4) {
printf("[bad length %u]", length);
return;
}
printf(" TS{");
hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
if ((length - 4) & (hoplen-1))
printf("[bad length %u]", length);
ptr = cp[2] - 1;
len = 0;
if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
printf("[bad ptr %u]", cp[2]);
switch (cp[3]&0xF) {
case IPOPT_TS_TSONLY:
printf("TSONLY");
break;
case IPOPT_TS_TSANDADDR:
printf("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:
printf("PRESPEC2.0");
break;
case 3: /* IPOPT_TS_PRESPEC */
printf("PRESPEC");
break;
default:
printf("[bad ts type %d]", cp[3]&0xF);
goto done;
}
type = " ";
for (len = 4; len < length; len += hoplen) {
if (ptr == len)
type = " ^ ";
printf("%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
hoplen!=8 ? "" : ipaddr_string(&cp[len]));
type = " ";
}
done:
printf("%s", ptr == len ? " ^ " : "");
if (cp[3]>>4)
printf(" [%d hops not recorded]} ", cp[3]>>4);
else
printf("}");
}
/*
* print IP options.
*/
static void
ip_optprint(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;
printf("%s", sep);
sep = ",";
TCHECK(*cp);
option_code = *cp;
printf("%s",
tok2str(ip_option_values,"unknown %u",option_code));
if (option_code == IPOPT_NOP ||
option_code == IPOPT_EOL)
option_len = 1;
else {
TCHECK(cp[1]);
option_len = cp[1];
if (option_len < 2) {
printf(" [bad length %u]", option_len);
return;
}
}
if (option_len > length) {
printf(" [bad length %u]", option_len);
return;
}
TCHECK2(*cp, option_len);
switch (option_code) {
case IPOPT_EOL:
return;
case IPOPT_TS:
ip_printts(cp, option_len);
break;
case IPOPT_RR: /* fall through */
case IPOPT_SSRR:
case IPOPT_LSRR:
ip_printroute(cp, option_len);
break;
case IPOPT_RA:
if (option_len < 4) {
printf(" [bad length %u]", option_len);
break;
}
TCHECK(cp[3]);
if (EXTRACT_16BITS(&cp[2]) != 0)
printf(" value %u", EXTRACT_16BITS(&cp[2]));
break;
case IPOPT_NOP: /* nothing to print - fall through */
case IPOPT_SECURITY:
default:
break;
}
}
return;
trunc:
printf("[|ip]");
}
#define IP_RES 0x8000
static 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(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(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(ipds->cp, (const u_char *)ipds->ip, ipds->len);
break;
case IPPROTO_DCCP:
dccp_print(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(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(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(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(ipds->cp, ipds->len, (const u_char *)ipds->ip);
break;
case IPPROTO_EIGRP:
eigrp_print(ipds->cp, ipds->len);
break;
case IPPROTO_ND:
ND_PRINT((ndo, " nd %d", ipds->len));
break;
case IPPROTO_EGP:
egp_print(ipds->cp, ipds->len);
break;
case IPPROTO_OSPF:
ospf_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
break;
case IPPROTO_IGMP:
igmp_print(ipds->cp, ipds->len);
break;
case IPPROTO_IPV4:
/* DVMRP multicast tunnel (ip-in-ip encapsulation) */
ip_print(ndo, ipds->cp, ipds->len);
if (! vflag) {
ND_PRINT((ndo, " (ipip-proto-4)"));
return;
}
break;
#ifdef INET6
case IPPROTO_IPV6:
/* ip6-in-ip encapsulation */
ip6_print(ndo, ipds->cp, ipds->len);
break;
#endif /*INET6*/
case IPPROTO_RSVP:
rsvp_print(ipds->cp, ipds->len);
break;
case IPPROTO_GRE:
/* do it */
gre_print(ipds->cp, ipds->len);
break;
case IPPROTO_MOBILE:
mobile_print(ipds->cp, ipds->len);
break;
case IPPROTO_PIM:
vec[0].ptr = ipds->cp;
vec[0].len = ipds->len;
pim_print(ipds->cp, ipds->len, in_cksum(vec, 1));
break;
case IPPROTO_VRRP:
if (packettype == PT_CARP) {
if (vflag)
(void)printf("carp %s > %s: ",
ipaddr_string(&ipds->ip->ip_src),
ipaddr_string(&ipds->ip->ip_dst));
carp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl);
} else {
if (vflag)
(void)printf("vrrp %s > %s: ",
ipaddr_string(&ipds->ip->ip_src),
ipaddr_string(&ipds->ip->ip_dst));
vrrp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl);
}
break;
case IPPROTO_PGM:
pgm_print(ipds->cp, ipds->len, (const u_char *)ipds->ip);
break;
case IPPROTO_PFSYNC:
pfsync_ip_print(ipds->cp, ipds->len);
break;
default:
if ((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];
u_int16_t sum, ip_sum;
struct protoent *proto;
ipds->ip = (const struct ip *)bp;
if (IP_V(ipds->ip) != 4) { /* print version if != 4 */
printf("IP%u ", IP_V(ipds->ip));
if (IP_V(ipds->ip) == 6)
printf(", wrong link-layer encapsulation");
}
else if (!eflag)
printf("IP ");
if ((u_char *)(ipds->ip + 1) > ndo->ndo_snapend) {
printf("[|ip]");
return;
}
if (length < sizeof (struct ip)) {
(void)printf("truncated-ip %u", length);
return;
}
hlen = IP_HL(ipds->ip) * 4;
if (hlen < sizeof (struct ip)) {
(void)printf("bad-hlen %u", hlen);
return;
}
ipds->len = EXTRACT_16BITS(&ipds->ip->ip_len);
if (length < ipds->len)
(void)printf("truncated-ip - %u bytes missing! ",
ipds->len - length);
if (ipds->len < hlen) {
#ifdef GUESS_TSO
if (ipds->len) {
(void)printf("bad-len %u", ipds->len);
return;
}
else {
/* we guess that it is a TSO send */
ipds->len = length;
}
#else
(void)printf("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 (vflag) {
(void)printf("(tos 0x%x", (int)ipds->ip->ip_tos);
/* ECN bits */
if (ipds->ip->ip_tos & 0x03) {
switch (ipds->ip->ip_tos & 0x03) {
case 1:
(void)printf(",ECT(1)");
break;
case 2:
(void)printf(",ECT(0)");
break;
case 3:
(void)printf(",CE");
}
}
if (ipds->ip->ip_ttl >= 1)
(void)printf(", 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.
*/
(void)printf(", 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);
(void)printf(", length %u", EXTRACT_16BITS(&ipds->ip->ip_len));
if ((hlen - sizeof(struct ip)) > 0) {
printf(", options (");
ip_optprint((u_char *)(ipds->ip + 1), hlen - sizeof(struct ip));
printf(")");
}
if (!Kflag && (u_char *)ipds->ip + hlen <= ndo->ndo_snapend) {
vec[0].ptr = (const u_int8_t *)(void *)ipds->ip;
vec[0].len = hlen;
sum = in_cksum(vec, 1);
if (sum != 0) {
ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum);
(void)printf(", bad cksum %x (->%x)!", ip_sum,
in_cksum_shouldbe(ip_sum, sum));
}
}
printf(")\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) {
(void)printf("%s > %s: ",
ipaddr_string(&ipds->ip->ip_src),
ipaddr_string(&ipds->ip->ip_dst));
}
ip_print_demux(ndo, ipds);
} else {
/* Ultra quiet now means that all this stuff should be suppressed */
if (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) {
(void)printf("%s > %s:", ipaddr_string(&ipds->ip->ip_src),
ipaddr_string(&ipds->ip->ip_dst));
if ((proto = getprotobynumber(ipds->ip->ip_p)) != NULL)
(void)printf(" %s", proto->p_name);
else
(void)printf(" ip-proto-%d", ipds->ip->ip_p);
}
}
}
void
ipN_print(register const u_char *bp, register u_int length)
{
struct ip *ip, hdr;
ip = (struct ip *)bp;
if (length < 4) {
(void)printf("truncated-ip %d", length);
return;
}
memcpy (&hdr, (char *)ip, 4);
switch (IP_V(&hdr)) {
case 4:
ip_print (gndo, bp, length);
return;
#ifdef INET6
case 6:
ip6_print (gndo, bp, length);
return;
#endif
default:
(void)printf("unknown ip %d", IP_V(&hdr));
return;
}
}
/*
* Local Variables:
* c-style: whitesmith
* c-basic-offset: 8
* End:
*/