808 lines
19 KiB
C
808 lines
19 KiB
C
/*
|
|
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Copyright (c) 1999-2004 The tcpdump.org project
|
|
*
|
|
* 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-tcp.c,v 1.120.2.2 2005/04/21 06:36:05 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 "interface.h"
|
|
#include "addrtoname.h"
|
|
#include "extract.h"
|
|
|
|
#include "tcp.h"
|
|
|
|
#include "ip.h"
|
|
#ifdef INET6
|
|
#include "ip6.h"
|
|
#endif
|
|
#include "ipproto.h"
|
|
#include "rpc_auth.h"
|
|
#include "rpc_msg.h"
|
|
|
|
#include "nameser.h"
|
|
|
|
#ifdef HAVE_LIBCRYPTO
|
|
#include <openssl/md5.h>
|
|
|
|
#define SIGNATURE_VALID 0
|
|
#define SIGNATURE_INVALID 1
|
|
#define CANT_CHECK_SIGNATURE 2
|
|
|
|
static int tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
|
|
const u_char *data, int length, const u_char *rcvsig);
|
|
#endif
|
|
|
|
static void print_tcp_rst_data(register const u_char *sp, u_int length);
|
|
|
|
#define MAX_RST_DATA_LEN 30
|
|
|
|
|
|
struct tha {
|
|
#ifndef INET6
|
|
struct in_addr src;
|
|
struct in_addr dst;
|
|
#else
|
|
struct in6_addr src;
|
|
struct in6_addr dst;
|
|
#endif /*INET6*/
|
|
u_int port;
|
|
};
|
|
|
|
struct tcp_seq_hash {
|
|
struct tcp_seq_hash *nxt;
|
|
struct tha addr;
|
|
tcp_seq seq;
|
|
tcp_seq ack;
|
|
};
|
|
|
|
#define TSEQ_HASHSIZE 919
|
|
|
|
/* These tcp optinos do not have the size octet */
|
|
#define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)
|
|
|
|
static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE];
|
|
|
|
|
|
#ifndef TELNET_PORT
|
|
#define TELNET_PORT 23
|
|
#endif
|
|
#ifndef BGP_PORT
|
|
#define BGP_PORT 179
|
|
#endif
|
|
#define NETBIOS_SSN_PORT 139
|
|
#ifndef PPTP_PORT
|
|
#define PPTP_PORT 1723
|
|
#endif
|
|
#define BEEP_PORT 10288
|
|
#ifndef NFS_PORT
|
|
#define NFS_PORT 2049
|
|
#endif
|
|
#define MSDP_PORT 639
|
|
#define LDP_PORT 646
|
|
|
|
static int tcp_cksum(register const struct ip *ip,
|
|
register const struct tcphdr *tp,
|
|
register u_int len)
|
|
{
|
|
union phu {
|
|
struct phdr {
|
|
u_int32_t src;
|
|
u_int32_t dst;
|
|
u_char mbz;
|
|
u_char proto;
|
|
u_int16_t len;
|
|
} ph;
|
|
u_int16_t pa[6];
|
|
} phu;
|
|
const u_int16_t *sp;
|
|
|
|
/* pseudo-header.. */
|
|
phu.ph.len = htons((u_int16_t)len);
|
|
phu.ph.mbz = 0;
|
|
phu.ph.proto = IPPROTO_TCP;
|
|
memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
|
|
if (IP_HL(ip) == 5)
|
|
memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
|
|
else
|
|
phu.ph.dst = ip_finddst(ip);
|
|
|
|
sp = &phu.pa[0];
|
|
return in_cksum((u_short *)tp, len,
|
|
sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]);
|
|
}
|
|
|
|
#ifdef INET6
|
|
static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp,
|
|
u_int len)
|
|
{
|
|
size_t i;
|
|
register const u_int16_t *sp;
|
|
u_int32_t sum;
|
|
union {
|
|
struct {
|
|
struct in6_addr ph_src;
|
|
struct in6_addr ph_dst;
|
|
u_int32_t ph_len;
|
|
u_int8_t ph_zero[3];
|
|
u_int8_t ph_nxt;
|
|
} ph;
|
|
u_int16_t pa[20];
|
|
} phu;
|
|
|
|
/* pseudo-header */
|
|
memset(&phu, 0, sizeof(phu));
|
|
phu.ph.ph_src = ip6->ip6_src;
|
|
phu.ph.ph_dst = ip6->ip6_dst;
|
|
phu.ph.ph_len = htonl(len);
|
|
phu.ph.ph_nxt = IPPROTO_TCP;
|
|
|
|
sum = 0;
|
|
for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
|
|
sum += phu.pa[i];
|
|
|
|
sp = (const u_int16_t *)tp;
|
|
|
|
for (i = 0; i < (len & ~1); i += 2)
|
|
sum += *sp++;
|
|
|
|
if (len & 1)
|
|
sum += htons((*(const u_int8_t *)sp) << 8);
|
|
|
|
while (sum > 0xffff)
|
|
sum = (sum & 0xffff) + (sum >> 16);
|
|
sum = ~sum & 0xffff;
|
|
|
|
return (sum);
|
|
}
|
|
#endif
|
|
|
|
void
|
|
tcp_print(register const u_char *bp, register u_int length,
|
|
register const u_char *bp2, int fragmented)
|
|
{
|
|
register const struct tcphdr *tp;
|
|
register const struct ip *ip;
|
|
register u_char flags;
|
|
register u_int hlen;
|
|
register char ch;
|
|
u_int16_t sport, dport, win, urp;
|
|
u_int32_t seq, ack, thseq, thack;
|
|
int threv;
|
|
#ifdef INET6
|
|
register const struct ip6_hdr *ip6;
|
|
#endif
|
|
|
|
tp = (struct tcphdr *)bp;
|
|
ip = (struct ip *)bp2;
|
|
#ifdef INET6
|
|
if (IP_V(ip) == 6)
|
|
ip6 = (struct ip6_hdr *)bp2;
|
|
else
|
|
ip6 = NULL;
|
|
#endif /*INET6*/
|
|
ch = '\0';
|
|
if (!TTEST(tp->th_dport)) {
|
|
(void)printf("%s > %s: [|tcp]",
|
|
ipaddr_string(&ip->ip_src),
|
|
ipaddr_string(&ip->ip_dst));
|
|
return;
|
|
}
|
|
|
|
sport = EXTRACT_16BITS(&tp->th_sport);
|
|
dport = EXTRACT_16BITS(&tp->th_dport);
|
|
|
|
hlen = TH_OFF(tp) * 4;
|
|
|
|
/*
|
|
* If data present, header length valid, and NFS port used,
|
|
* assume NFS.
|
|
* Pass offset of data plus 4 bytes for RPC TCP msg length
|
|
* to NFS print routines.
|
|
*/
|
|
if (!qflag && hlen >= sizeof(*tp) && hlen <= length) {
|
|
if ((u_char *)tp + 4 + sizeof(struct sunrpc_msg) <= snapend &&
|
|
dport == NFS_PORT) {
|
|
nfsreq_print((u_char *)tp + hlen + 4, length - hlen,
|
|
(u_char *)ip);
|
|
return;
|
|
} else if ((u_char *)tp + 4 + sizeof(struct sunrpc_msg)
|
|
<= snapend &&
|
|
sport == NFS_PORT) {
|
|
nfsreply_print((u_char *)tp + hlen + 4, length - hlen,
|
|
(u_char *)ip);
|
|
return;
|
|
}
|
|
}
|
|
#ifdef INET6
|
|
if (ip6) {
|
|
if (ip6->ip6_nxt == IPPROTO_TCP) {
|
|
(void)printf("%s.%s > %s.%s: ",
|
|
ip6addr_string(&ip6->ip6_src),
|
|
tcpport_string(sport),
|
|
ip6addr_string(&ip6->ip6_dst),
|
|
tcpport_string(dport));
|
|
} else {
|
|
(void)printf("%s > %s: ",
|
|
tcpport_string(sport), tcpport_string(dport));
|
|
}
|
|
} else
|
|
#endif /*INET6*/
|
|
{
|
|
if (ip->ip_p == IPPROTO_TCP) {
|
|
(void)printf("%s.%s > %s.%s: ",
|
|
ipaddr_string(&ip->ip_src),
|
|
tcpport_string(sport),
|
|
ipaddr_string(&ip->ip_dst),
|
|
tcpport_string(dport));
|
|
} else {
|
|
(void)printf("%s > %s: ",
|
|
tcpport_string(sport), tcpport_string(dport));
|
|
}
|
|
}
|
|
|
|
if (hlen < sizeof(*tp)) {
|
|
(void)printf(" tcp %d [bad hdr length %u - too short, < %lu]",
|
|
length - hlen, hlen, (unsigned long)sizeof(*tp));
|
|
return;
|
|
}
|
|
|
|
TCHECK(*tp);
|
|
|
|
seq = EXTRACT_32BITS(&tp->th_seq);
|
|
ack = EXTRACT_32BITS(&tp->th_ack);
|
|
win = EXTRACT_16BITS(&tp->th_win);
|
|
urp = EXTRACT_16BITS(&tp->th_urp);
|
|
|
|
if (qflag) {
|
|
(void)printf("tcp %d", length - hlen);
|
|
if (hlen > length) {
|
|
(void)printf(" [bad hdr length %u - too long, > %u]",
|
|
hlen, length);
|
|
}
|
|
return;
|
|
}
|
|
if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|
|
|
TH_ECNECHO|TH_CWR)) {
|
|
if (flags & TH_SYN)
|
|
putchar('S');
|
|
if (flags & TH_FIN)
|
|
putchar('F');
|
|
if (flags & TH_RST)
|
|
putchar('R');
|
|
if (flags & TH_PUSH)
|
|
putchar('P');
|
|
if (flags & TH_CWR)
|
|
putchar('W'); /* congestion _W_indow reduced (ECN) */
|
|
if (flags & TH_ECNECHO)
|
|
putchar('E'); /* ecn _E_cho sent (ECN) */
|
|
} else
|
|
putchar('.');
|
|
|
|
if (!Sflag && (flags & TH_ACK)) {
|
|
register struct tcp_seq_hash *th;
|
|
const void *src, *dst;
|
|
register int rev;
|
|
struct tha tha;
|
|
/*
|
|
* Find (or record) the initial sequence numbers for
|
|
* this conversation. (we pick an arbitrary
|
|
* collating order so there's only one entry for
|
|
* both directions).
|
|
*/
|
|
#ifdef INET6
|
|
memset(&tha, 0, sizeof(tha));
|
|
rev = 0;
|
|
if (ip6) {
|
|
src = &ip6->ip6_src;
|
|
dst = &ip6->ip6_dst;
|
|
if (sport > dport)
|
|
rev = 1;
|
|
else if (sport == dport) {
|
|
if (memcmp(src, dst, sizeof ip6->ip6_dst) > 0)
|
|
rev = 1;
|
|
}
|
|
if (rev) {
|
|
memcpy(&tha.src, dst, sizeof ip6->ip6_dst);
|
|
memcpy(&tha.dst, src, sizeof ip6->ip6_src);
|
|
tha.port = dport << 16 | sport;
|
|
} else {
|
|
memcpy(&tha.dst, dst, sizeof ip6->ip6_dst);
|
|
memcpy(&tha.src, src, sizeof ip6->ip6_src);
|
|
tha.port = sport << 16 | dport;
|
|
}
|
|
} else {
|
|
src = &ip->ip_src;
|
|
dst = &ip->ip_dst;
|
|
if (sport > dport)
|
|
rev = 1;
|
|
else if (sport == dport) {
|
|
if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
|
|
rev = 1;
|
|
}
|
|
if (rev) {
|
|
memcpy(&tha.src, dst, sizeof ip->ip_dst);
|
|
memcpy(&tha.dst, src, sizeof ip->ip_src);
|
|
tha.port = dport << 16 | sport;
|
|
} else {
|
|
memcpy(&tha.dst, dst, sizeof ip->ip_dst);
|
|
memcpy(&tha.src, src, sizeof ip->ip_src);
|
|
tha.port = sport << 16 | dport;
|
|
}
|
|
}
|
|
#else
|
|
rev = 0;
|
|
src = &ip->ip_src;
|
|
dst = &ip->ip_dst;
|
|
if (sport > dport)
|
|
rev = 1;
|
|
else if (sport == dport) {
|
|
if (memcmp(src, dst, sizeof ip->ip_dst) > 0)
|
|
rev = 1;
|
|
}
|
|
if (rev) {
|
|
memcpy(&tha.src, dst, sizeof ip->ip_dst);
|
|
memcpy(&tha.dst, src, sizeof ip->ip_src);
|
|
tha.port = dport << 16 | sport;
|
|
} else {
|
|
memcpy(&tha.dst, dst, sizeof ip->ip_dst);
|
|
memcpy(&tha.src, src, sizeof ip->ip_src);
|
|
tha.port = sport << 16 | dport;
|
|
}
|
|
#endif
|
|
|
|
threv = rev;
|
|
for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
|
|
th->nxt; th = th->nxt)
|
|
if (memcmp((char *)&tha, (char *)&th->addr,
|
|
sizeof(th->addr)) == 0)
|
|
break;
|
|
|
|
if (!th->nxt || (flags & TH_SYN)) {
|
|
/* didn't find it or new conversation */
|
|
if (th->nxt == NULL) {
|
|
th->nxt = (struct tcp_seq_hash *)
|
|
calloc(1, sizeof(*th));
|
|
if (th->nxt == NULL)
|
|
error("tcp_print: calloc");
|
|
}
|
|
th->addr = tha;
|
|
if (rev)
|
|
th->ack = seq, th->seq = ack - 1;
|
|
else
|
|
th->seq = seq, th->ack = ack - 1;
|
|
} else {
|
|
if (rev)
|
|
seq -= th->ack, ack -= th->seq;
|
|
else
|
|
seq -= th->seq, ack -= th->ack;
|
|
}
|
|
|
|
thseq = th->seq;
|
|
thack = th->ack;
|
|
} else {
|
|
/*fool gcc*/
|
|
thseq = thack = threv = 0;
|
|
}
|
|
if (hlen > length) {
|
|
(void)printf(" [bad hdr length %u - too long, > %u]",
|
|
hlen, length);
|
|
return;
|
|
}
|
|
|
|
if (IP_V(ip) == 4 && vflag && !fragmented) {
|
|
u_int16_t sum, tcp_sum;
|
|
if (TTEST2(tp->th_sport, length)) {
|
|
sum = tcp_cksum(ip, tp, length);
|
|
|
|
(void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum));
|
|
if (sum != 0) {
|
|
tcp_sum = EXTRACT_16BITS(&tp->th_sum);
|
|
(void)printf(" (incorrect (-> 0x%04x),",in_cksum_shouldbe(tcp_sum, sum));
|
|
} else
|
|
(void)printf(" (correct),");
|
|
}
|
|
}
|
|
#ifdef INET6
|
|
if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !fragmented) {
|
|
u_int16_t sum,tcp_sum;
|
|
if (TTEST2(tp->th_sport, length)) {
|
|
sum = tcp6_cksum(ip6, tp, length);
|
|
(void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum));
|
|
if (sum != 0) {
|
|
tcp_sum = EXTRACT_16BITS(&tp->th_sum);
|
|
(void)printf(" (incorrect (-> 0x%04x),",in_cksum_shouldbe(tcp_sum, sum));
|
|
} else
|
|
(void)printf(" (correct),");
|
|
|
|
}
|
|
}
|
|
#endif
|
|
|
|
length -= hlen;
|
|
if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST))
|
|
(void)printf(" %u:%u(%u)", seq, seq + length, length);
|
|
if (flags & TH_ACK)
|
|
(void)printf(" ack %u", ack);
|
|
|
|
(void)printf(" win %d", win);
|
|
|
|
if (flags & TH_URG)
|
|
(void)printf(" urg %d", urp);
|
|
/*
|
|
* Handle any options.
|
|
*/
|
|
if (hlen > sizeof(*tp)) {
|
|
register const u_char *cp;
|
|
register u_int i, opt, datalen;
|
|
register u_int len;
|
|
|
|
hlen -= sizeof(*tp);
|
|
cp = (const u_char *)tp + sizeof(*tp);
|
|
putchar(' ');
|
|
ch = '<';
|
|
while (hlen > 0) {
|
|
putchar(ch);
|
|
TCHECK(*cp);
|
|
opt = *cp++;
|
|
if (ZEROLENOPT(opt))
|
|
len = 1;
|
|
else {
|
|
TCHECK(*cp);
|
|
len = *cp++; /* total including type, len */
|
|
if (len < 2 || len > hlen)
|
|
goto bad;
|
|
--hlen; /* account for length byte */
|
|
}
|
|
--hlen; /* account for type byte */
|
|
datalen = 0;
|
|
|
|
/* Bail if "l" bytes of data are not left or were not captured */
|
|
#define LENCHECK(l) { if ((l) > hlen) goto bad; TCHECK2(*cp, l); }
|
|
|
|
switch (opt) {
|
|
|
|
case TCPOPT_MAXSEG:
|
|
(void)printf("mss");
|
|
datalen = 2;
|
|
LENCHECK(datalen);
|
|
(void)printf(" %u", EXTRACT_16BITS(cp));
|
|
|
|
break;
|
|
|
|
case TCPOPT_EOL:
|
|
(void)printf("eol");
|
|
break;
|
|
|
|
case TCPOPT_NOP:
|
|
(void)printf("nop");
|
|
break;
|
|
|
|
case TCPOPT_WSCALE:
|
|
(void)printf("wscale");
|
|
datalen = 1;
|
|
LENCHECK(datalen);
|
|
(void)printf(" %u", *cp);
|
|
break;
|
|
|
|
case TCPOPT_SACKOK:
|
|
(void)printf("sackOK");
|
|
break;
|
|
|
|
case TCPOPT_SACK:
|
|
datalen = len - 2;
|
|
if (datalen % 8 != 0) {
|
|
(void)printf("malformed sack");
|
|
} else {
|
|
u_int32_t s, e;
|
|
|
|
(void)printf("sack %d ", datalen / 8);
|
|
for (i = 0; i < datalen; i += 8) {
|
|
LENCHECK(i + 4);
|
|
s = EXTRACT_32BITS(cp + i);
|
|
LENCHECK(i + 8);
|
|
e = EXTRACT_32BITS(cp + i + 4);
|
|
if (threv) {
|
|
s -= thseq;
|
|
e -= thseq;
|
|
} else {
|
|
s -= thack;
|
|
e -= thack;
|
|
}
|
|
(void)printf("{%u:%u}", s, e);
|
|
}
|
|
}
|
|
break;
|
|
|
|
case TCPOPT_ECHO:
|
|
(void)printf("echo");
|
|
datalen = 4;
|
|
LENCHECK(datalen);
|
|
(void)printf(" %u", EXTRACT_32BITS(cp));
|
|
break;
|
|
|
|
case TCPOPT_ECHOREPLY:
|
|
(void)printf("echoreply");
|
|
datalen = 4;
|
|
LENCHECK(datalen);
|
|
(void)printf(" %u", EXTRACT_32BITS(cp));
|
|
break;
|
|
|
|
case TCPOPT_TIMESTAMP:
|
|
(void)printf("timestamp");
|
|
datalen = 8;
|
|
LENCHECK(4);
|
|
(void)printf(" %u", EXTRACT_32BITS(cp));
|
|
LENCHECK(datalen);
|
|
(void)printf(" %u", EXTRACT_32BITS(cp + 4));
|
|
break;
|
|
|
|
case TCPOPT_CC:
|
|
(void)printf("cc");
|
|
datalen = 4;
|
|
LENCHECK(datalen);
|
|
(void)printf(" %u", EXTRACT_32BITS(cp));
|
|
break;
|
|
|
|
case TCPOPT_CCNEW:
|
|
(void)printf("ccnew");
|
|
datalen = 4;
|
|
LENCHECK(datalen);
|
|
(void)printf(" %u", EXTRACT_32BITS(cp));
|
|
break;
|
|
|
|
case TCPOPT_CCECHO:
|
|
(void)printf("ccecho");
|
|
datalen = 4;
|
|
LENCHECK(datalen);
|
|
(void)printf(" %u", EXTRACT_32BITS(cp));
|
|
break;
|
|
|
|
case TCPOPT_SIGNATURE:
|
|
(void)printf("md5:");
|
|
datalen = TCP_SIGLEN;
|
|
LENCHECK(datalen);
|
|
#ifdef HAVE_LIBCRYPTO
|
|
switch (tcp_verify_signature(ip, tp,
|
|
bp + TH_OFF(tp) * 4, length, cp)) {
|
|
|
|
case SIGNATURE_VALID:
|
|
(void)printf("valid");
|
|
break;
|
|
|
|
case SIGNATURE_INVALID:
|
|
(void)printf("invalid");
|
|
break;
|
|
|
|
case CANT_CHECK_SIGNATURE:
|
|
(void)printf("can't check - ");
|
|
for (i = 0; i < TCP_SIGLEN; ++i)
|
|
(void)printf("%02x", cp[i]);
|
|
break;
|
|
}
|
|
#else
|
|
for (i = 0; i < TCP_SIGLEN; ++i)
|
|
(void)printf("%02x", cp[i]);
|
|
#endif
|
|
break;
|
|
|
|
default:
|
|
(void)printf("opt-%u:", opt);
|
|
datalen = len - 2;
|
|
for (i = 0; i < datalen; ++i) {
|
|
LENCHECK(i);
|
|
(void)printf("%02x", cp[i]);
|
|
}
|
|
break;
|
|
}
|
|
|
|
/* Account for data printed */
|
|
cp += datalen;
|
|
hlen -= datalen;
|
|
|
|
/* Check specification against observed length */
|
|
++datalen; /* option octet */
|
|
if (!ZEROLENOPT(opt))
|
|
++datalen; /* size octet */
|
|
if (datalen != len)
|
|
(void)printf("[len %d]", len);
|
|
ch = ',';
|
|
if (opt == TCPOPT_EOL)
|
|
break;
|
|
}
|
|
putchar('>');
|
|
}
|
|
|
|
if (length <= 0)
|
|
return;
|
|
|
|
/*
|
|
* Decode payload if necessary.
|
|
*/
|
|
bp += TH_OFF(tp) * 4;
|
|
if (flags & TH_RST) {
|
|
if (vflag)
|
|
print_tcp_rst_data(bp, length);
|
|
} else {
|
|
if (sport == TELNET_PORT || dport == TELNET_PORT) {
|
|
if (!qflag && vflag)
|
|
telnet_print(bp, length);
|
|
} else if (sport == BGP_PORT || dport == BGP_PORT)
|
|
bgp_print(bp, length);
|
|
else if (sport == PPTP_PORT || dport == PPTP_PORT)
|
|
pptp_print(bp);
|
|
#ifdef TCPDUMP_DO_SMB
|
|
else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
|
|
nbt_tcp_print(bp, length);
|
|
#endif
|
|
else if (sport == BEEP_PORT || dport == BEEP_PORT)
|
|
beep_print(bp, length);
|
|
else if (length > 2 &&
|
|
(sport == NAMESERVER_PORT || dport == NAMESERVER_PORT ||
|
|
sport == MULTICASTDNS_PORT || dport == MULTICASTDNS_PORT)) {
|
|
/*
|
|
* TCP DNS query has 2byte length at the head.
|
|
* XXX packet could be unaligned, it can go strange
|
|
*/
|
|
ns_print(bp + 2, length - 2, 0);
|
|
} else if (sport == MSDP_PORT || dport == MSDP_PORT) {
|
|
msdp_print(bp, length);
|
|
}
|
|
else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) {
|
|
ldp_print(bp, length);
|
|
}
|
|
}
|
|
return;
|
|
bad:
|
|
fputs("[bad opt]", stdout);
|
|
if (ch != '\0')
|
|
putchar('>');
|
|
return;
|
|
trunc:
|
|
fputs("[|tcp]", stdout);
|
|
if (ch != '\0')
|
|
putchar('>');
|
|
}
|
|
|
|
/*
|
|
* RFC1122 says the following on data in RST segments:
|
|
*
|
|
* 4.2.2.12 RST Segment: RFC-793 Section 3.4
|
|
*
|
|
* A TCP SHOULD allow a received RST segment to include data.
|
|
*
|
|
* DISCUSSION
|
|
* It has been suggested that a RST segment could contain
|
|
* ASCII text that encoded and explained the cause of the
|
|
* RST. No standard has yet been established for such
|
|
* data.
|
|
*
|
|
*/
|
|
|
|
static void
|
|
print_tcp_rst_data(register const u_char *sp, u_int length)
|
|
{
|
|
int c;
|
|
|
|
if (TTEST2(*sp, length))
|
|
printf(" [RST");
|
|
else
|
|
printf(" [!RST");
|
|
if (length > MAX_RST_DATA_LEN) {
|
|
length = MAX_RST_DATA_LEN; /* can use -X for longer */
|
|
putchar('+'); /* indicate we truncate */
|
|
}
|
|
putchar(' ');
|
|
while (length-- && sp <= snapend) {
|
|
c = *sp++;
|
|
safeputchar(c);
|
|
}
|
|
putchar(']');
|
|
}
|
|
|
|
#ifdef HAVE_LIBCRYPTO
|
|
static int
|
|
tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp,
|
|
const u_char *data, int length, const u_char *rcvsig)
|
|
{
|
|
struct tcphdr tp1;
|
|
u_char sig[TCP_SIGLEN];
|
|
char zero_proto = 0;
|
|
MD5_CTX ctx;
|
|
u_int16_t savecsum, tlen;
|
|
#ifdef INET6
|
|
struct ip6_hdr *ip6;
|
|
#endif
|
|
u_int32_t len32;
|
|
u_int8_t nxt;
|
|
|
|
tp1 = *tp;
|
|
|
|
if (tcpmd5secret == NULL)
|
|
return (CANT_CHECK_SIGNATURE);
|
|
|
|
MD5_Init(&ctx);
|
|
/*
|
|
* Step 1: Update MD5 hash with IP pseudo-header.
|
|
*/
|
|
if (IP_V(ip) == 4) {
|
|
MD5_Update(&ctx, (char *)&ip->ip_src, sizeof(ip->ip_src));
|
|
MD5_Update(&ctx, (char *)&ip->ip_dst, sizeof(ip->ip_dst));
|
|
MD5_Update(&ctx, (char *)&zero_proto, sizeof(zero_proto));
|
|
MD5_Update(&ctx, (char *)&ip->ip_p, sizeof(ip->ip_p));
|
|
tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4;
|
|
tlen = htons(tlen);
|
|
MD5_Update(&ctx, (char *)&tlen, sizeof(tlen));
|
|
#ifdef INET6
|
|
} else if (IP_V(ip) == 6) {
|
|
ip6 = (struct ip6_hdr *)ip;
|
|
MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src));
|
|
MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));
|
|
len32 = htonl(ntohs(ip6->ip6_plen));
|
|
MD5_Update(&ctx, (char *)&len32, sizeof(len32));
|
|
nxt = 0;
|
|
MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
|
|
MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
|
|
MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
|
|
nxt = IPPROTO_TCP;
|
|
MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));
|
|
#endif
|
|
} else
|
|
return (CANT_CHECK_SIGNATURE);
|
|
|
|
/*
|
|
* Step 2: Update MD5 hash with TCP header, excluding options.
|
|
* The TCP checksum must be set to zero.
|
|
*/
|
|
savecsum = tp1.th_sum;
|
|
tp1.th_sum = 0;
|
|
MD5_Update(&ctx, (char *)&tp1, sizeof(struct tcphdr));
|
|
tp1.th_sum = savecsum;
|
|
/*
|
|
* Step 3: Update MD5 hash with TCP segment data, if present.
|
|
*/
|
|
if (length > 0)
|
|
MD5_Update(&ctx, data, length);
|
|
/*
|
|
* Step 4: Update MD5 hash with shared secret.
|
|
*/
|
|
MD5_Update(&ctx, tcpmd5secret, strlen(tcpmd5secret));
|
|
MD5_Final(sig, &ctx);
|
|
|
|
if (memcmp(rcvsig, sig, 16) == 0)
|
|
return (SIGNATURE_VALID);
|
|
else
|
|
return (SIGNATURE_INVALID);
|
|
}
|
|
#endif /* HAVE_LIBCRYPTO */
|