NetBSD/usr.sbin/tcpdump/tcpdump.c

459 lines
10 KiB
C

/* $NetBSD: tcpdump.c,v 1.7 1997/10/17 13:50:26 lukem 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: tcpdump.c,v 1.129 97/06/13 13:10:11 leres Exp (LBL)";
#else
__COPYRIGHT("@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997\n\
The Regents of the University of California. All rights reserved.\n");
__RCSID("$NetBSD: tcpdump.c,v 1.7 1997/10/17 13:50:26 lukem Exp $");
#endif
#endif
/*
* tcpdump - monitor tcp/ip traffic on an ethernet.
*
* First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
* Mercilessly hacked and occasionally improved since then via the
* combined efforts of Van, Steve McCanne and Craig Leres of LBL.
*/
#include <sys/types.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <pcap.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "interface.h"
#include "addrtoname.h"
#include "machdep.h"
#include "setsignal.h"
#include "gmt2local.h"
int aflag; /* translate network and broadcast addresses */
int dflag; /* print filter code */
int eflag; /* print ethernet header */
int fflag; /* don't translate "foreign" IP address */
int nflag; /* leave addresses as numbers */
int Nflag; /* remove domains from printed host names */
int Oflag = 1; /* run filter code optimizer */
int pflag; /* don't go promiscuous */
int qflag; /* quick (shorter) output */
int Sflag; /* print raw TCP sequence numbers */
int tflag = 1; /* print packet arrival time */
int vflag; /* verbose */
int xflag; /* print packet in hex */
int packettype;
char *program_name;
int32_t thiszone; /* seconds offset from gmt to local time */
/* Externs */
extern void bpf_dump(struct bpf_program *, int);
/* Forwards */
RETSIGTYPE cleanup(int);
extern __dead void usage(void) __attribute__((volatile));
/* Length of saved portion of packet. */
int snaplen = DEFAULT_SNAPLEN;
struct printer {
pcap_handler f;
int type;
};
static struct printer printers[] = {
{ ether_if_print, DLT_EN10MB },
{ ether_if_print, DLT_IEEE802 },
{ sl_if_print, DLT_SLIP },
{ sl_bsdos_if_print, DLT_SLIP_BSDOS },
{ ppp_if_print, DLT_PPP },
{ ppp_bsdos_if_print, DLT_PPP_BSDOS },
{ fddi_if_print, DLT_FDDI },
{ null_if_print, DLT_NULL },
{ raw_if_print, DLT_RAW },
{ atm_if_print, DLT_ATM_RFC1483 },
{ NULL, 0 },
};
static pcap_handler
lookup_printer(int type)
{
struct printer *p;
for (p = printers; p->f; ++p)
if (type == p->type)
return p->f;
error("unknown data link type 0x%x", type);
/* NOTREACHED */
}
static pcap_t *pd;
extern int optind;
extern int opterr;
extern char *optarg;
int
main(int argc, char **argv)
{
register int cnt, op, i;
bpf_u_int32 localnet, netmask;
register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
pcap_handler printer;
struct bpf_program fcode;
RETSIGTYPE (*oldhandler)(int);
u_char *pcap_userdata;
char ebuf[PCAP_ERRBUF_SIZE];
cnt = -1;
device = NULL;
infile = NULL;
RFileName = NULL;
WFileName = NULL;
if ((cp = strrchr(argv[0], '/')) != NULL)
program_name = cp + 1;
else
program_name = argv[0];
if (abort_on_misalignment(ebuf) < 0)
error("%s", ebuf);
opterr = 0;
while (
(op = getopt(argc, argv, "ac:defF:i:lnNOpqr:s:StT:vw:xY")) != -1)
switch (op) {
case 'a':
++aflag;
break;
case 'c':
cnt = atoi(optarg);
if (cnt <= 0)
error("invalid packet count %s", optarg);
break;
case 'd':
++dflag;
break;
case 'e':
++eflag;
break;
case 'f':
++fflag;
break;
case 'F':
infile = optarg;
break;
case 'i':
device = optarg;
break;
case 'l':
#ifdef HAVE_SETLINEBUF
setlinebuf(stdout);
#else
setvbuf(stdout, NULL, _IOLBF, 0);
#endif
break;
case 'n':
++nflag;
break;
case 'N':
++Nflag;
break;
case 'O':
Oflag = 0;
break;
case 'p':
++pflag;
break;
case 'q':
++qflag;
break;
case 'r':
RFileName = optarg;
break;
case 's':
snaplen = atoi(optarg);
if (snaplen <= 0)
error("invalid snaplen %s", optarg);
break;
case 'S':
++Sflag;
break;
case 't':
--tflag;
break;
case 'T':
if (strcasecmp(optarg, "vat") == 0)
packettype = PT_VAT;
else if (strcasecmp(optarg, "wb") == 0)
packettype = PT_WB;
else if (strcasecmp(optarg, "rpc") == 0)
packettype = PT_RPC;
else if (strcasecmp(optarg, "rtp") == 0)
packettype = PT_RTP;
else if (strcasecmp(optarg, "rtcp") == 0)
packettype = PT_RTCP;
else
error("unknown packet type `%s'", optarg);
break;
case 'v':
++vflag;
break;
case 'w':
WFileName = optarg;
break;
#ifdef YYDEBUG
case 'Y':
{
/* Undocumented flag */
extern int yydebug;
yydebug = 1;
}
break;
#endif
case 'x':
++xflag;
break;
default:
usage();
/* NOTREACHED */
}
if (aflag && nflag)
error("-a and -n options are incompatible");
if (tflag > 0)
thiszone = gmt2local(0);
if (RFileName != NULL) {
/*
* We don't need network access, so set it back to the user id.
* Also, this prevents the user from reading anyone's
* trace file.
*/
setuid(getuid());
pd = pcap_open_offline(RFileName, ebuf);
if (pd == NULL)
error("%s", ebuf);
localnet = 0;
netmask = 0;
if (fflag != 0)
error("-f and -r options are incompatible");
} else {
if (device == NULL) {
device = pcap_lookupdev(ebuf);
if (device == NULL)
error("%s", ebuf);
}
pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
if (pd == NULL)
error("%s", ebuf);
i = pcap_snapshot(pd);
if (snaplen < i) {
warning("snaplen raised from %d to %d", snaplen, i);
snaplen = i;
}
if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
localnet = 0;
netmask = 0;
warning("%s", ebuf);
}
/*
* Let user own process after socket has been opened.
*/
setuid(getuid());
}
if (infile)
cmdbuf = read_infile(infile);
else
cmdbuf = copy_argv(&argv[optind]);
if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
error("%s", pcap_geterr(pd));
if (dflag) {
bpf_dump(&fcode, dflag);
exit(0);
}
init_addrtoname(localnet, netmask);
(void)setsignal(SIGTERM, cleanup);
(void)setsignal(SIGINT, cleanup);
/* Cooperate with nohup(1) */
if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
(void)setsignal(SIGHUP, oldhandler);
if (pcap_setfilter(pd, &fcode) < 0)
error("%s", pcap_geterr(pd));
if (WFileName) {
pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
if (p == NULL)
error("%s", pcap_geterr(pd));
printer = pcap_dump;
pcap_userdata = (u_char *)p;
} else {
printer = lookup_printer(pcap_datalink(pd));
pcap_userdata = 0;
}
if (RFileName == NULL) {
(void)fprintf(stderr, "%s: listening on %s\n",
program_name, device);
(void)fflush(stderr);
}
if (pcap_loop(pd, cnt, printer, pcap_userdata) < 0) {
(void)fprintf(stderr, "%s: pcap_loop: %s\n",
program_name, pcap_geterr(pd));
exit(1);
}
pcap_close(pd);
exit(0);
}
/* make a clean exit on interrupts */
RETSIGTYPE
cleanup(int signo)
{
struct pcap_stat stat;
/* Can't print the summary if reading from a savefile */
if (pd != NULL && pcap_file(pd) == NULL) {
(void)fflush(stdout);
putc('\n', stderr);
if (pcap_stats(pd, &stat) < 0)
(void)fprintf(stderr, "pcap_stats: %s\n",
pcap_geterr(pd));
else {
(void)fprintf(stderr, "%d packets received by filter\n",
stat.ps_recv);
(void)fprintf(stderr, "%d packets dropped by kernel\n",
stat.ps_drop);
}
}
exit(0);
}
/* Like default_print() but data need not be aligned */
void
default_print_unaligned(register const u_char *cp, register u_int length)
{
register u_int i, s;
register int nshorts;
nshorts = (u_int) length / sizeof(u_short);
i = 0;
while (--nshorts >= 0) {
if ((i++ % 8) == 0)
(void)printf("\n\t\t\t");
s = *cp++;
(void)printf(" %02x%02x", s, *cp++);
}
if (length & 1) {
if ((i % 8) == 0)
(void)printf("\n\t\t\t");
(void)printf(" %02x", *cp);
}
}
/*
* By default, print the packet out in hex.
*
* (BTW, please don't send us patches to print the packet out in ascii)
*/
void
default_print(register const u_char *bp, register u_int length)
{
register const u_short *sp;
register u_int i;
register int nshorts;
if ((long)bp & 1) {
default_print_unaligned(bp, length);
return;
}
sp = (u_short *)bp;
nshorts = (u_int) length / sizeof(u_short);
i = 0;
while (--nshorts >= 0) {
if ((i++ % 8) == 0)
(void)printf("\n\t\t\t");
(void)printf(" %04x", ntohs(*sp++));
}
if (length & 1) {
if ((i % 8) == 0)
(void)printf("\n\t\t\t");
(void)printf(" %02x", *(u_char *)sp);
}
}
__dead void
usage(void)
{
extern char version[];
extern char pcap_version[];
(void)fprintf(stderr, "%s version %s\n", program_name, version);
(void)fprintf(stderr, "libpcap version %s\n", pcap_version);
(void)fprintf(stderr,
"Usage: %s [-adeflnNOpqStvx] [-c count] [ -F file ]\n", program_name);
(void)fprintf(stderr,
"\t\t[ -i interface ] [ -r file ] [ -s snaplen ]\n");
(void)fprintf(stderr,
"\t\t[ -T type ] [ -w file ] [ expression ]\n");
exit(-1);
}