1 /* $OpenBSD: pflogd.c,v 1.45 2007/06/06 14:11:26 henning Exp $ */
4 * Copyright (c) 2001 Theo de Raadt
5 * Copyright (c) 2001 Can Erkin Acar
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * - Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * - Redistributions in binary form must reproduce the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer in the documentation and/or other materials provided
17 * with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
23 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
25 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
27 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
29 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
33 #include <sys/types.h>
34 #include <sys/ioctl.h>
37 #include <sys/socket.h>
61 static int snaplen = DEF_SNAPLEN;
62 static int cur_snaplen = DEF_SNAPLEN;
64 volatile sig_atomic_t gotsig_close, gotsig_alrm, gotsig_hup, gotsig_usr1;
66 const char *filename = PFLOGD_LOG_FILE;
67 const char *interface = PFLOGD_DEFAULT_IF;
70 char errbuf[PCAP_ERRBUF_SIZE];
73 unsigned int delay = FLUSH_DELAY;
75 char *copy_argv(char * const *);
76 void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
77 void dump_packet_nobuf(u_char *, const struct pcap_pkthdr *, const u_char *);
78 void log_pcap_stats(void);
79 int flush_buffer(FILE *);
80 int if_exists(char *);
82 void purge_buffer(void);
84 int scan_dump(FILE *, off_t);
86 void set_suspended(int);
91 void usage(void) __dead2;
93 static int try_reset_dump(int);
95 /* buffer must always be greater than snaplen */
96 static int bufpkt = 0; /* number of packets in buffer */
97 static size_t buflen = 0; /* allocated size of buffer */
98 static char *buffer = NULL; /* packet buffer */
99 static char *bufpos = NULL; /* position in buffer */
100 static size_t bufleft = 0; /* bytes left in buffer */
102 /* if error, stop logging but count dropped packets */
103 static int suspended = -1;
104 static long packets_dropped = 0;
113 setproctitle("[%s] -s %d -i %s -f %s",
114 suspended ? "suspended" : "running",
115 cur_snaplen, interface, filename);
119 copy_argv(char * const *argv)
127 for (n = 0; argv[n]; n++)
128 len += strlen(argv[n])+1;
136 strlcpy(buf, argv[0], len);
137 for (n = 1; argv[n]; n++) {
138 strlcat(buf, " ", len);
139 strlcat(buf, argv[n], len);
145 logmsg(int pri, const char *message, ...)
148 va_start(ap, message);
151 vfprintf(stderr, message, ap);
152 fprintf(stderr, "\n");
154 vsyslog(pri, message, ap);
161 fprintf(stderr, "usage: pflogd [-Dx] [-d delay] [-f filename]");
162 fprintf(stderr, " [-i interface] [-p pidfile]\n");
163 fprintf(stderr, " [-s snaplen] [expression]\n");
168 sig_close(int sig __unused)
174 sig_hup(int sig __unused)
180 sig_alrm(int sig __unused)
186 sig_usr1(int sig __unused)
192 set_pcap_filter(void)
194 struct bpf_program bprog;
196 if (pcap_compile(hpcap, &bprog, filter, PCAP_OPT_FIL, 0) < 0)
197 logmsg(LOG_WARNING, "%s", pcap_geterr(hpcap));
199 if (pcap_setfilter(hpcap, &bprog) < 0)
200 logmsg(LOG_WARNING, "%s", pcap_geterr(hpcap));
201 pcap_freecode(&bprog);
206 if_exists(char *ifname)
210 struct if_data ifrdat;
212 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
214 bzero(&ifr, sizeof(ifr));
215 if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >=
216 sizeof(ifr.ifr_name))
217 errx(1, "main ifr_name: strlcpy");
218 ifr.ifr_data = (caddr_t)&ifrdat;
219 if (ioctl(s, SIOCGIFDATA, (caddr_t)&ifr) == -1)
230 hpcap = pcap_open_live(interface, snaplen, 1, PCAP_TO_MS, errbuf);
232 logmsg(LOG_ERR, "Failed to initialize: %s", errbuf);
236 if (pcap_datalink(hpcap) != DLT_PFLOG) {
237 logmsg(LOG_ERR, "Invalid datalink type");
245 cur_snaplen = snaplen = pcap_snapshot(hpcap);
247 /* From contrib/pf/pflogd.c 1.5 FreeBSD: BPF locking is not
250 #ifndef __DragonFly__
252 if (ioctl(pcap_fileno(hpcap), BIOCLOCK) < 0) {
253 logmsg(LOG_ERR, "BIOCLOCK: %s", strerror(errno));
262 set_snaplen(int snap)
264 if (priv_set_snaplen(snap))
267 if (cur_snaplen > snap)
276 reset_dump(int nomove)
281 ret = try_reset_dump(nomove);
290 * tries to (re)open log file, nomove flag is used with -x switch
291 * returns 0: success, 1: retry (log moved), -1: error
294 try_reset_dump(int nomove)
296 struct pcap_file_header hdr;
311 * Basically reimplement pcap_dump_open() because it truncates
312 * files and duplicates headers and such.
314 fd = priv_open_log();
318 fp = fdopen(fd, "a+");
321 logmsg(LOG_ERR, "Error: %s: %s", filename, strerror(errno));
325 if (fstat(fileno(fp), &st) == -1) {
326 logmsg(LOG_ERR, "Error: %s: %s", filename, strerror(errno));
331 /* set FILE unbuffered, we do our own buffering */
332 if (setvbuf(fp, NULL, _IONBF, 0)) {
333 logmsg(LOG_ERR, "Failed to set output buffers");
338 #define TCPDUMP_MAGIC 0xa1b2c3d4
340 if (st.st_size == 0) {
341 if (snaplen != cur_snaplen) {
342 logmsg(LOG_NOTICE, "Using snaplen %d", snaplen);
343 if (set_snaplen(snaplen))
345 "Failed, using old settings");
347 hdr.magic = TCPDUMP_MAGIC;
348 hdr.version_major = PCAP_VERSION_MAJOR;
349 hdr.version_minor = PCAP_VERSION_MINOR;
350 hdr.thiszone = hpcap->tzoff;
351 hdr.snaplen = hpcap->snapshot;
353 hdr.linktype = hpcap->linktype;
355 if (fwrite((char *)&hdr, sizeof(hdr), 1, fp) != 1) {
359 } else if (scan_dump(fp, st.st_size)) {
361 if (nomove || priv_move_log()) {
363 "Invalid/incompatible log file, move it away");
378 scan_dump(FILE *fp, off_t size)
380 struct pcap_file_header hdr;
381 struct pcap_sf_pkthdr ph;
385 * Must read the file, compare the header against our new
386 * options (in particular, snaplen) and adjust our options so
387 * that we generate a correct file. Furthermore, check the file
388 * for consistency so that we can append safely.
390 * XXX this may take a long time for large logs.
392 fseek(fp, 0L, SEEK_SET);
394 if (fread((char *)&hdr, sizeof(hdr), 1, fp) != 1) {
395 logmsg(LOG_ERR, "Short file header");
399 if (hdr.magic != TCPDUMP_MAGIC ||
400 hdr.version_major != PCAP_VERSION_MAJOR ||
401 hdr.version_minor != PCAP_VERSION_MINOR ||
402 (int)hdr.linktype != hpcap->linktype ||
403 hdr.snaplen > PFLOGD_MAXSNAPLEN) {
410 off_t len = fread((char *)&ph, 1, sizeof(ph), fp);
414 if (len != sizeof(ph))
416 if (ph.caplen > hdr.snaplen || ph.caplen > PFLOGD_MAXSNAPLEN)
418 pos += sizeof(ph) + ph.caplen;
421 fseek(fp, ph.caplen, SEEK_CUR);
427 if ((int)hdr.snaplen != cur_snaplen) {
429 "Existing file has different snaplen %u, using it",
431 if (set_snaplen(hdr.snaplen)) {
433 "Failed, using old settings, offset %llu",
434 (unsigned long long) size);
441 logmsg(LOG_ERR, "Corrupted log file.");
445 /* dump a packet directly to the stream, which is unbuffered */
447 dump_packet_nobuf(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
449 FILE *f = (FILE *)user;
450 struct pcap_sf_pkthdr sh;
457 sh.ts.tv_sec = (bpf_int32)h->ts.tv_sec;
458 sh.ts.tv_usec = (bpf_int32)h->ts.tv_usec;
459 sh.caplen = h->caplen;
462 if (fwrite((char *)&sh, sizeof(sh), 1, f) != 1) {
463 off_t pos = ftello(f);
465 /* try to undo header to prevent corruption */
466 if ((size_t)pos < sizeof(sh) ||
467 ftruncate(fileno(f), pos - sizeof(sh))) {
468 logmsg(LOG_ERR, "Write failed, corrupted logfile!");
476 if (fwrite(sp, h->caplen, 1, f) != 1)
484 logmsg(LOG_ERR, "Logging suspended: fwrite: %s", strerror(errno));
488 flush_buffer(FILE *f)
491 int len = bufpos - buffer;
497 if (offset == (off_t)-1) {
499 logmsg(LOG_ERR, "Logging suspended: ftello: %s",
504 if (fwrite(buffer, len, 1, f) != 1) {
506 logmsg(LOG_ERR, "Logging suspended: fwrite: %s",
508 ftruncate(fileno(f), offset);
523 packets_dropped += bufpkt;
531 /* append packet to the buffer, flushing if necessary */
533 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
535 FILE *f = (FILE *)user;
536 struct pcap_sf_pkthdr sh;
537 size_t len = sizeof(sh) + h->caplen;
539 if (len < sizeof(*h) || h->caplen > (size_t)cur_snaplen) {
540 logmsg(LOG_NOTICE, "invalid size %zd (%u/%u), packet dropped",
541 len, cur_snaplen, snaplen);
554 if (flush_buffer(f)) {
560 dump_packet_nobuf(user, h, sp);
565 sh.ts.tv_sec = (bpf_int32)h->ts.tv_sec;
566 sh.ts.tv_usec = (bpf_int32)h->ts.tv_usec;
567 sh.caplen = h->caplen;
570 memcpy(bufpos, &sh, sizeof(sh));
571 memcpy(bufpos + sizeof(sh), sp, h->caplen);
583 struct pcap_stat pstat;
584 if (pcap_stats(hpcap, &pstat) < 0)
585 logmsg(LOG_WARNING, "Reading stats: %s", pcap_geterr(hpcap));
588 "%u packets received, %u/%ld dropped (kernel/pflogd)",
589 pstat.ps_recv, pstat.ps_drop, packets_dropped);
593 main(int argc, char **argv)
595 int ch, np, ret, Xflag = 0;
596 pcap_handler phandler = dump_packet;
597 const char *errstr = NULL;
598 struct pidfh *pfh = NULL;
603 /* Neither FreeBSD nor DFly have this; Max seems to think this may
604 * be a paranoid check. Comment it out:
605 closefrom(STDERR_FILENO + 1);
608 while ((ch = getopt(argc, argv, "Dxd:f:i:p:s:")) != -1) {
614 delay = strtonum(optarg, 5, 60*60, &errstr);
628 snaplen = strtonum(optarg, 0, PFLOGD_MAXSNAPLEN,
631 snaplen = DEF_SNAPLEN;
633 snaplen = PFLOGD_MAXSNAPLEN;
648 /* does interface exist */
649 if (!if_exists(__DECONST(char *, interface))) {
650 warn("Failed to initialize: %s", interface);
651 logmsg(LOG_ERR, "Failed to initialize: %s", interface);
652 logmsg(LOG_ERR, "Exiting, init failure");
657 openlog("pflogd", LOG_PID | LOG_CONS, LOG_DAEMON);
658 pfh = pidfile_open(pidf, 0600, NULL);
660 logmsg(LOG_WARNING, "Failed to become daemon: %s",
667 umask(S_IRWXG | S_IRWXO);
669 /* filter will be used by the privileged process */
671 filter = copy_argv(argv);
673 logmsg(LOG_NOTICE, "Failed to form filter expression");
676 /* initialize pcap before dropping privileges */
678 logmsg(LOG_ERR, "Exiting, init failure");
682 /* Privilege separation begins here */
684 logmsg(LOG_ERR, "unable to privsep");
688 setproctitle("[initializing]");
689 /* Process is now unprivileged and inside a chroot */
690 signal(SIGTERM, sig_close);
691 signal(SIGINT, sig_close);
692 signal(SIGQUIT, sig_close);
693 signal(SIGALRM, sig_alrm);
694 signal(SIGUSR1, sig_usr1);
695 signal(SIGHUP, sig_hup);
698 buffer = malloc(PFLOGD_BUFSIZE);
700 if (buffer == NULL) {
701 logmsg(LOG_WARNING, "Failed to allocate output buffer");
702 phandler = dump_packet_nobuf;
704 bufleft = buflen = PFLOGD_BUFSIZE;
709 if (reset_dump(Xflag) < 0) {
713 logmsg(LOG_ERR, "Logging suspended: open error");
719 np = pcap_dispatch(hpcap, PCAP_NUM_PKTS,
720 phandler, (u_char *)dpcap);
722 if (!if_exists(__DECONST(char *, interface))) {
723 logmsg(LOG_NOTICE, "interface %s went away",
728 logmsg(LOG_NOTICE, "%s", pcap_geterr(hpcap));
736 "Logging suspended: open error");
757 logmsg(LOG_NOTICE, "Exiting");