6f8f50af89
- Enable WARNS?=6. - Include missing headers. - Mark prog and pidfile as static. Remove unneeded initializer. - Use ANSI prototypes. - Remove unneeded fp variable. - snprintf() guarantees the buffer to be null terminated. Remove unneeded - 1 and bzero call. - Remove unneeded casting. Submitted by: Pawel Worach, Christoph Mallon
304 lines
6.6 KiB
C
304 lines
6.6 KiB
C
/*
|
|
* copy diverted (or tee'd) packets to a file in 'tcpdump' format
|
|
* (ie. this uses the '-lpcap' routines).
|
|
*
|
|
* example usage:
|
|
* # ipfwpcap -r 8091 divt.log &
|
|
* # ipfw add 2864 divert 8091 ip from 128.432.53.82 to any
|
|
* # ipfw add 2864 divert 8091 ip from any to 128.432.53.82
|
|
*
|
|
* the resulting dump file can be read with ...
|
|
* # tcpdump -nX -r divt.log
|
|
*/
|
|
/*
|
|
* Written by P Kern { pkern [AT] cns.utoronto.ca }
|
|
*
|
|
* Copyright (c) 2004 University of Toronto. All rights reserved.
|
|
* Anyone may use or copy this software except that this copyright
|
|
* notice remain intact and that credit is given where it is due.
|
|
* The University of Toronto and the author make no warranty and
|
|
* accept no liability for this software.
|
|
*
|
|
* From: Header: /local/src/local.lib/SRC/ipfwpcap/RCS/ipfwpcap.c,v 1.4 2004/01/15 16:19:07 pkern Exp
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
#include <paths.h>
|
|
#include <fcntl.h>
|
|
#include <signal.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/types.h>
|
|
#include <sys/time.h>
|
|
#include <sys/param.h> /* for MAXPATHLEN */
|
|
#include <sys/socket.h>
|
|
#include <netinet/in.h>
|
|
|
|
#include <netinet/in_systm.h> /* for IP_MAXPACKET */
|
|
#include <netinet/ip.h> /* for IP_MAXPACKET */
|
|
|
|
/* XXX normally defined in config.h */
|
|
#define HAVE_STRLCPY 1
|
|
#define HAVE_SNPRINTF 1
|
|
#define HAVE_VSNPRINTF 1
|
|
#include <pcap-int.h> /* see pcap(3) and /usr/src/contrib/libpcap/. */
|
|
|
|
#ifdef IP_MAXPACKET
|
|
#define BUFMAX IP_MAXPACKET
|
|
#else
|
|
#define BUFMAX 65535
|
|
#endif
|
|
|
|
#ifndef MAXPATHLEN
|
|
#define MAXPATHLEN 1024
|
|
#endif
|
|
|
|
static int debug = 0;
|
|
static int reflect = 0; /* 1 == write packet back to socket. */
|
|
|
|
static ssize_t totbytes = 0, maxbytes = 0;
|
|
static ssize_t totpkts = 0, maxpkts = 0;
|
|
|
|
static char *prog = NULL;
|
|
static char pidfile[MAXPATHLEN];
|
|
|
|
/*
|
|
* tidy up.
|
|
*/
|
|
static void
|
|
quit(int sig)
|
|
{
|
|
(void) unlink(pidfile);
|
|
exit(sig);
|
|
}
|
|
|
|
/*
|
|
* do the "paper work"
|
|
* - save my own pid in /var/run/$0.{port#}.pid
|
|
*/
|
|
static void
|
|
okay(int pn)
|
|
{
|
|
int fd;
|
|
char *p, numbuf[80];
|
|
|
|
if (pidfile[0] == '\0') {
|
|
p = rindex(prog, '/');
|
|
p = (p == NULL) ? prog : p + 1;
|
|
|
|
snprintf(pidfile, sizeof pidfile,
|
|
"%s%s.%d.pid", _PATH_VARRUN, p, pn);
|
|
}
|
|
|
|
fd = open(pidfile, O_WRONLY|O_CREAT|O_EXCL, 0644);
|
|
if (fd < 0) {
|
|
perror(pidfile);
|
|
exit(21);
|
|
}
|
|
|
|
siginterrupt(SIGTERM, 1);
|
|
siginterrupt(SIGHUP, 1);
|
|
signal(SIGTERM, quit);
|
|
signal(SIGHUP, quit);
|
|
signal(SIGINT, quit);
|
|
|
|
snprintf(numbuf, sizeof numbuf, "%d\n", getpid());
|
|
if (write(fd, numbuf, strlen(numbuf)) < 0) {
|
|
perror(pidfile);
|
|
quit(23);
|
|
}
|
|
(void) close(fd);
|
|
}
|
|
|
|
static void
|
|
usage(void)
|
|
{
|
|
fprintf(stderr,
|
|
"\n"
|
|
"usage:\n"
|
|
" %s [-dr] [-b maxbytes] [-p maxpkts] [-P pidfile] portnum dumpfile\n"
|
|
"\n"
|
|
"where:\n"
|
|
" '-d' = enable debugging messages.\n"
|
|
" '-r' = reflect. write packets back to the divert socket.\n"
|
|
" (ie. simulate the original intent of \"ipfw tee\").\n"
|
|
" '-rr' = indicate that it is okay to quit if packet-count or\n"
|
|
" byte-count limits are reached (see the NOTE below\n"
|
|
" about what this implies).\n"
|
|
" '-b bytcnt' = stop dumping after {bytcnt} bytes.\n"
|
|
" '-p pktcnt' = stop dumping after {pktcnt} packets.\n"
|
|
" '-P pidfile' = alternate file to store the PID\n"
|
|
" (default: /var/run/%s.{portnum}.pid).\n"
|
|
"\n"
|
|
" portnum = divert(4) socket port number.\n"
|
|
" dumpfile = file to write captured packets (tcpdump format).\n"
|
|
" (specify '-' to write packets to stdout).\n"
|
|
"\n"
|
|
"The '-r' option should not be necessary, but because \"ipfw tee\" is broken\n"
|
|
"(see BUGS in ipfw(8) for details) this feature can be used along with\n"
|
|
"an \"ipfw divert\" rule to simulate the original intent of \"ipfw tee\".\n"
|
|
"\n"
|
|
"NOTE: With an \"ipfw divert\" rule, diverted packets will silently\n"
|
|
" disappear if there is nothing listening to the divert socket.\n"
|
|
"\n", prog, prog);
|
|
exit(1);
|
|
}
|
|
|
|
int
|
|
main(int ac, char *av[])
|
|
{
|
|
int r, sd, portnum, l;
|
|
struct sockaddr_in sin;
|
|
int errflg = 0;
|
|
|
|
int nfd;
|
|
fd_set rds;
|
|
|
|
ssize_t nr;
|
|
|
|
char *dumpf, buf[BUFMAX];
|
|
|
|
pcap_t *p;
|
|
pcap_dumper_t *dp;
|
|
struct pcap_pkthdr phd;
|
|
|
|
prog = av[0];
|
|
|
|
while ((r = getopt(ac, av, "drb:p:P:")) != -1) {
|
|
switch (r) {
|
|
case 'd':
|
|
debug++;
|
|
break;
|
|
case 'r':
|
|
reflect++;
|
|
break;
|
|
case 'b':
|
|
maxbytes = (ssize_t) atol(optarg);
|
|
break;
|
|
case 'p':
|
|
maxpkts = (ssize_t) atoi(optarg);
|
|
break;
|
|
case 'P':
|
|
strcpy(pidfile, optarg);
|
|
break;
|
|
case '?':
|
|
default:
|
|
errflg++;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if ((ac - optind) != 2 || errflg)
|
|
usage();
|
|
|
|
portnum = atoi(av[optind++]);
|
|
dumpf = av[optind];
|
|
|
|
if (debug) fprintf(stderr, "bind to %d.\ndump to '%s'.\n", portnum, dumpf);
|
|
|
|
if ((r = socket(PF_INET, SOCK_RAW, IPPROTO_DIVERT)) == -1) {
|
|
perror("socket(DIVERT)");
|
|
exit(2);
|
|
}
|
|
sd = r;
|
|
|
|
sin.sin_port = htons(portnum);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_addr.s_addr = INADDR_ANY;
|
|
|
|
if (bind(sd, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
|
|
perror("bind(divert)");
|
|
exit(3);
|
|
}
|
|
|
|
p = pcap_open_dead(DLT_RAW, BUFMAX);
|
|
dp = pcap_dump_open(p, dumpf);
|
|
if (dp == NULL) {
|
|
pcap_perror(p, dumpf);
|
|
exit(4);
|
|
}
|
|
|
|
okay(portnum);
|
|
|
|
nfd = sd + 1;
|
|
for (;;) {
|
|
FD_ZERO(&rds);
|
|
FD_SET(sd, &rds);
|
|
|
|
r = select(nfd, &rds, NULL, NULL, NULL);
|
|
if (r == -1) {
|
|
if (errno == EINTR) continue;
|
|
perror("select");
|
|
quit(11);
|
|
}
|
|
|
|
if (!FD_ISSET(sd, &rds))
|
|
/* hmm. no work. */
|
|
continue;
|
|
|
|
/*
|
|
* use recvfrom(3 and sendto(3) as in natd(8).
|
|
* see /usr/src/sbin/natd/natd.c
|
|
* see ipfw(8) about using 'divert' and 'tee'.
|
|
*/
|
|
|
|
/*
|
|
* read packet.
|
|
*/
|
|
l = sizeof(sin);
|
|
nr = recvfrom(sd, buf, sizeof(buf), 0, (struct sockaddr *)&sin, &l);
|
|
if (debug) fprintf(stderr, "recvfrom(%d) = %zd (%d)\n", sd, nr, l);
|
|
if (nr < 0 && errno != EINTR) {
|
|
perror("recvfrom(sd)");
|
|
quit(12);
|
|
}
|
|
if (nr <= 0) continue;
|
|
|
|
if (reflect) {
|
|
/*
|
|
* write packet back so it can continue
|
|
* being processed by any further IPFW rules.
|
|
*/
|
|
l = sizeof(sin);
|
|
r = sendto(sd, buf, nr, 0, (struct sockaddr *)&sin, l);
|
|
if (debug) fprintf(stderr, " sendto(%d) = %d\n", sd, r);
|
|
if (r < 0) { perror("sendto(sd)"); quit(13); }
|
|
}
|
|
|
|
/*
|
|
* check maximums, if any.
|
|
* but don't quit if must continue reflecting packets.
|
|
*/
|
|
if (maxpkts) {
|
|
totpkts++;
|
|
if (totpkts > maxpkts) {
|
|
if (reflect == 1) continue;
|
|
quit(0);
|
|
}
|
|
}
|
|
if (maxbytes) {
|
|
totbytes += nr;
|
|
if (totbytes > maxbytes) {
|
|
if (reflect == 1) continue;
|
|
quit(0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* save packet in tcpdump(1) format. see pcap(3).
|
|
* divert packets are fully assembled. see ipfw(8).
|
|
*/
|
|
(void) gettimeofday(&(phd.ts), NULL);
|
|
phd.caplen = phd.len = nr;
|
|
pcap_dump((u_char *)dp, &phd, buf);
|
|
if (ferror((FILE *)dp)) { perror(dumpf); quit(14); }
|
|
(void) fflush((FILE *)dp);
|
|
}
|
|
|
|
quit(0);
|
|
}
|