NetBSD/usr.sbin/tcpdump/print-tcp.c

556 lines
12 KiB
C

/* $NetBSD: print-tcp.c,v 1.15 1999/09/30 14:49:13 sjg Exp $ */
/*
* 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.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static const char rcsid[] =
"@(#) Header: print-tcp.c,v 1.55 97/06/15 13:20:28 leres Exp (LBL)";
#else
__RCSID("$NetBSD: print-tcp.c,v 1.15 1999/09/30 14:49:13 sjg Exp $");
#endif
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>
#include <rpc/rpc.h>
#ifdef HAVE_MEMORY_H
#include <memory.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef INET6
#include <netinet/ip6.h>
#endif
#include "interface.h"
#include "addrtoname.h"
#include "extract.h"
#include "nfs.h"
#ifndef TCPOPT_WSCALE
#define TCPOPT_WSCALE 3 /* window scale factor (rfc1072) */
#endif
#ifndef TCPOPT_SACKOK
#define TCPOPT_SACKOK 4 /* selective ack ok (rfc1072) */
#endif
#ifndef TCPOPT_SACK
#define TCPOPT_SACK 5 /* selective ack (rfc1072) */
#endif
#ifndef TCPOPT_ECHO
#define TCPOPT_ECHO 6 /* echo (rfc1072) */
#endif
#ifndef TCPOPT_ECHOREPLY
#define TCPOPT_ECHOREPLY 7 /* echo (rfc1072) */
#endif
#ifndef TCPOPT_TIMESTAMP
#define TCPOPT_TIMESTAMP 8 /* timestamps (rfc1323) */
#endif
#ifndef TCPOPT_CC
#define TCPOPT_CC 11 /* T/TCP CC options (rfc1644) */
#endif
#ifndef TCPOPT_CCNEW
#define TCPOPT_CCNEW 12 /* T/TCP CC options (rfc1644) */
#endif
#ifndef TCPOPT_CCECHO
#define TCPOPT_CCECHO 13 /* T/TCP CC options (rfc1644) */
#endif
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];
static int tcp_cksum(register const struct ip *ip,
register const struct tcphdr *tp,
register int len)
{
int i, tlen;
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;
register const u_int16_t *sp;
u_int32_t sum;
tlen = ntohs(ip->ip_len) - ((const char *)tp-(const char*)ip);
/* pseudo-header.. */
phu.ph.len = htons(tlen);
phu.ph.mbz = 0;
phu.ph.proto = ip->ip_p;
memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
sp = &phu.pa[0];
sum = sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5];
sp = (const u_int16_t *)tp;
for (i=0; i<(tlen&~1); i+= 2)
sum += *sp++;
if (tlen & 1) {
sum += htons( (*(const char *)sp) << 8);
}
while (sum > 0xffff)
sum = (sum & 0xffff) + (sum >> 16);
sum = ~sum & 0xffff;
return (sum);
}
void
tcp_print(register const u_char *bp, register u_int length,
register const u_char *bp2)
{
register const struct tcphdr *tp;
register const struct ip *ip;
register u_char flags;
register int hlen;
register char ch;
u_int16_t sport, dport, win, urp;
tcp_seq seq, ack;
#ifdef INET6
register const struct ip6_hdr *ip6;
#endif
tp = (struct tcphdr *)bp;
ip = (struct ip *)bp2;
#ifdef INET6
if (ip->ip_v == 6)
ip6 = (struct ip6_hdr *)bp2;
else
ip6 = NULL;
#endif /*INET6*/
ch = '\0';
TCHECK(*tp);
if (length < sizeof(*tp)) {
(void)printf("truncated-tcp %d", length);
return;
}
sport = ntohs(tp->th_sport);
dport = ntohs(tp->th_dport);
seq = ntohl(tp->th_seq);
ack = ntohl(tp->th_ack);
win = ntohs(tp->th_win);
urp = ntohs(tp->th_urp);
hlen = tp->th_off * 4;
/*
* If data present and NFS port used, assume NFS.
* Pass offset of data plus 4 bytes for RPC TCP msg length
* to NFS print routines.
*/
if (!qflag) {
u_int len = length - hlen;
if ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
dport == NFS_PORT) {
nfsreq_print((u_char *)tp + hlen + 4, len,
(u_char *)ip);
return;
}
else if ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
sport == NFS_PORT) {
nfsreply_print((u_char *)tp + hlen + 4, len,
(u_char *)ip);
return;
}
}
#ifdef INET6
if (ip6) {
if (bp == (u_char *)(ip6 + 1)) {
(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 (bp == (u_char *)(ip + 1)) {
(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 (qflag) {
(void)printf("tcp %d", length - tp->th_off * 4);
return;
}
#ifdef TH_ECN
if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|TH_ECN))
#else
if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH))
#endif
{
if (flags & TH_SYN)
putchar('S');
if (flags & TH_FIN)
putchar('F');
if (flags & TH_RST)
putchar('R');
if (flags & TH_PUSH)
putchar('P');
#ifdef TH_ECN
if (flags & TH_ECN)
putchar('C');
#endif
} else
putchar('.');
if (!Sflag && (flags & TH_ACK)) {
register struct tcp_seq_hash *th;
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
bzero(&tha, sizeof(tha));
rev = 0;
if (ip6) {
if (sport > dport) {
rev = 1;
} else if (sport == dport) {
int i;
for (i = 0; i < 4; i++) {
if (((u_int32_t *)(&ip6->ip6_src))[i] >
((u_int32_t *)(&ip6->ip6_dst))[i]) {
rev = 1;
break;
}
}
}
if (rev) {
tha.src = ip6->ip6_dst;
tha.dst = ip6->ip6_src;
tha.port = dport << 16 | sport;
} else {
tha.dst = ip6->ip6_dst;
tha.src = ip6->ip6_src;
tha.port = sport << 16 | dport;
}
} else {
if (sport > dport ||
(sport == dport &&
ip->ip_src.s_addr > ip->ip_dst.s_addr)) {
rev = 1;
}
if (rev) {
*(struct in_addr *)&tha.src = ip->ip_dst;
*(struct in_addr *)&tha.dst = ip->ip_src;
tha.port = dport << 16 | sport;
} else {
*(struct in_addr *)&tha.dst = ip->ip_dst;
*(struct in_addr *)&tha.src = ip->ip_src;
tha.port = sport << 16 | dport;
}
}
#else
if (sport < dport ||
(sport == dport &&
ip->ip_src.s_addr < ip->ip_dst.s_addr)) {
tha.src = ip->ip_src, tha.dst = ip->ip_dst;
tha.port = sport << 16 | dport;
rev = 0;
} else {
tha.src = ip->ip_dst, tha.dst = ip->ip_src;
tha.port = dport << 16 | sport;
rev = 1;
}
#endif
for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];
th->nxt; th = th->nxt)
if (!memcmp((char *)&tha, (char *)&th->addr,
sizeof(th->addr)))
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;
}
}
hlen = tp->th_off * 4;
if (hlen > length) {
(void)printf(" [bad hdr length]");
return;
}
if (ip->ip_v == 4 && vflag) {
int sum;
if (TTEST2(tp->th_sport, length)) {
sum = tcp_cksum(ip, tp, length);
if (sum != 0)
(void)printf(" [bad tcp cksum %x!]", sum);
else
(void)printf(" [tcp sum ok]");
}
}
length -= hlen;
if (length > 0 || flags & (TH_SYN | TH_FIN | TH_RST))
(void)printf(" %lu:%lu(%d)", (long) seq, (long) (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)) > 0) {
register const u_char *cp;
register int i, opt, len, datalen;
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:
(void)printf("sack");
datalen = len - 2;
for (i = 0; i < datalen; i += 4) {
LENCHECK(i + 4);
/* block-size@relative-origin */
(void)printf(" %u@%u",
EXTRACT_16BITS(cp + i + 2),
EXTRACT_16BITS(cp + i));
}
if (datalen % 4)
(void)printf("[len %d]", len);
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;
default:
(void)printf("opt-%d:", 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('>');
}
#ifndef TELNET_PORT
# define TELNET_PORT 23
#endif
if (!qflag && vflag && length > 0
&& (dport == TELNET_PORT || sport == TELNET_PORT)) {
hlen = tp->th_off * 4; /* restore it */
telnet_print((u_char *)tp + hlen, length);
}
return;
bad:
fputs("[bad opt]", stdout);
if (ch != '\0')
putchar('>');
return;
trunc:
fputs("[|tcp]", stdout);
if (ch != '\0')
putchar('>');
}