/* $NetBSD: tcpdump.c,v 1.6 2002/09/22 16:59:16 thorpej Exp $ */ /* * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000 * 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. * * Support for splitting captures into multiple files with a maximum * file size: * * Copyright (c) 2001 * Seth Webster */ #include #ifndef lint #if 0 static const char copyright[] = "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\ The Regents of the University of California. All rights reserved.\n"; static const char rcsid[] = "@(#) Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.176 2002/05/16 10:25:58 guy Exp (LBL)"; #else __RCSID("$NetBSD: tcpdump.c,v 1.6 2002/09/22 16:59:16 thorpej 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #include #include #include #include #include #include #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 Lflag; /* list available data link types and exit */ 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 Rflag = 1; /* print sequence # field in AH/ESP*/ int sflag = 0; /* use the libsmi to translate OIDs */ int Sflag; /* print raw TCP sequence numbers */ int tflag = 1; /* print packet arrival time */ int uflag = 0; /* Print undecoded NFS handles */ int vflag; /* verbose */ int xflag; /* print packet in hex */ int Xflag; /* print packet in ascii as well as hex */ off_t Cflag = 0; /* rotate dump files after this many bytes */ int Aflag = 0; /* print packet only in ascii observing LF, CR, TAB, SPACE */ int dlt = -1; /* if != -1, ask libpcap for the DLT it names */ const char *dlt_name = NULL; char *espsecret = NULL; /* ESP secret key */ int packettype; int infodelay; int infoprint; char *program_name; int32_t thiszone; /* seconds offset from gmt to local time */ /* Forwards */ static RETSIGTYPE cleanup(int); static void usage(void) __attribute__((noreturn)); static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn)); static void dump_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *); #ifdef SIGINFO RETSIGTYPE requestinfo(int); #endif /* Length of saved portion of packet. */ int snaplen = DEFAULT_SNAPLEN; struct printer { pcap_handler f; int type; }; static struct printer printers[] = { { arcnet_if_print, DLT_ARCNET }, { ether_if_print, DLT_EN10MB }, { token_if_print, DLT_IEEE802 }, #ifdef DLT_LANE8023 { lane_if_print, DLT_LANE8023 }, #endif #ifdef DLT_CIP { cip_if_print, DLT_CIP }, #endif #ifdef DLT_ATM_CLIP { cip_if_print, DLT_ATM_CLIP }, #endif { 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 }, #ifdef DLT_LOOP { null_if_print, DLT_LOOP }, #endif { raw_if_print, DLT_RAW }, { atm_if_print, DLT_ATM_RFC1483 }, #ifdef DLT_C_HDLC { chdlc_if_print, DLT_C_HDLC }, #endif #ifdef DLT_HDLC { chdlc_if_print, DLT_HDLC }, #endif #ifdef DLT_PPP_SERIAL { ppp_hdlc_if_print, DLT_PPP_SERIAL }, #endif #ifdef DLT_PPP_ETHER { pppoe_if_print, DLT_PPP_ETHER }, #endif #ifdef DLT_LINUX_SLL { sll_if_print, DLT_LINUX_SLL }, #endif #ifdef DLT_IEEE802_11 { ieee802_11_if_print, DLT_IEEE802_11}, #endif #ifdef DLT_LTALK { ltalk_if_print, DLT_LTALK }, #endif #ifdef DLT_PFLOG { pflog_if_print, DLT_PFLOG }, #endif { 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 %d", type); /* NOTREACHED */ } static pcap_t *pd; extern int optind; extern int opterr; extern char *optarg; struct dump_info { char *WFileName; pcap_t *pd; pcap_dumper_t *p; }; struct dlt_choice { const char* name; int dlt; }; #define DLT_CHOICE(code) { #code, code } #define DLT_CHOICE_SENTINEL { NULL, 0 } struct dlt_choice dlt_choices[] = { DLT_CHOICE(DLT_ARCNET), DLT_CHOICE(DLT_EN10MB), DLT_CHOICE(DLT_IEEE802), #ifdef DLT_LANE8023 DLT_CHOICE(DLT_LANE8023), #endif #ifdef DLT_CIP DLT_CHOICE(DLT_CIP), #endif #ifdef DLT_ATM_CLIP DLT_CHOICE(DLT_ATM_CLIP), #endif DLT_CHOICE(DLT_SLIP), DLT_CHOICE(DLT_SLIP_BSDOS), DLT_CHOICE(DLT_PPP), DLT_CHOICE(DLT_PPP_BSDOS), DLT_CHOICE(DLT_FDDI), DLT_CHOICE(DLT_NULL), #ifdef DLT_LOOP DLT_CHOICE(DLT_LOOP), #endif DLT_CHOICE(DLT_RAW), DLT_CHOICE(DLT_ATM_RFC1483), #ifdef DLT_C_HDLC DLT_CHOICE(DLT_C_HDLC), #endif #ifdef DLT_HDLC DLT_CHOICE(DLT_HDLC), #endif #ifdef DLT_PPP_SERIAL DLT_CHOICE(DLT_PPP_SERIAL), #endif #ifdef DLT_PPP_ETHER DLT_CHOICE(DLT_PPP_ETHER), #endif #ifdef DLT_LINUX_SLL DLT_CHOICE(DLT_LINUX_SLL), #endif #ifdef DLT_IEEE802_11 DLT_CHOICE(DLT_IEEE802_11), #endif #ifdef DLT_LTALK DLT_CHOICE(DLT_LTALK), #endif #ifdef DLT_PFLOG DLT_CHOICE(DLT_PFLOG), #endif DLT_CHOICE_SENTINEL }; static void show_dlts_and_exit(pcap_t *pd) { int i, n_dlts; int *dlts = 0; n_dlts = pcap_list_datalinks(pd, &dlts); if (n_dlts < 0) error("%s", pcap_geterr(pd)); else if (n_dlts == 0 || !dlts) error("No data link types."); (void) fprintf(stderr, "Data link types (use option -D):\n"); while (--n_dlts >= 0) { for (i = 0; dlt_choices[i].name; i++) { if (dlt_choices[i].dlt != dlts[n_dlts]) { continue; } (void) fprintf(stderr, " %s\n", dlt_choices[i].name + sizeof("DLT_") - 1); break; } if (!dlt_choices[i].name) fprintf(stderr, " %d (not supported)\n", dlts[n_dlts]); } free(dlts); exit(0); } 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); struct dump_info dumpinfo; 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, sizeof(ebuf)) < 0) error("%s", ebuf); #ifdef LIBSMI smiInit("tcpdump"); #endif opterr = 0; while ( (op = getopt(argc, argv, "aAc:C:dD:eE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXY")) != -1) switch (op) { case 'a': ++aflag; break; case 'A': ++xflag; ++Xflag; ++Aflag; break; case 'c': cnt = atoi(optarg); if (cnt <= 0) error("invalid packet count %s", optarg); break; case 'C': Cflag = atoi(optarg) * 1000000; if (Cflag < 0) error("invalid file size %s", optarg); break; case 'd': ++dflag; break; case 'D': for (i = 0; dlt_choices[i].name; i++) { if (!strcasecmp(dlt_choices[i].name + sizeof("DLT_") - 1, optarg)) { dlt = dlt_choices[i].dlt; dlt_name = dlt_choices[i].name; break; } } if (dlt < 0) { error("invalid data link type %s", optarg); } break; case 'L': Lflag++; break; case 'e': ++eflag; break; case 'E': #ifndef HAVE_LIBCRYPTO warning("crypto code not compiled in"); #endif espsecret = optarg; 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 'm': #ifdef LIBSMI if (smiLoadModule(optarg) == 0) { error("could not load MIB module %s", optarg); } sflag = 1; #else (void)fprintf(stderr, "%s: ignoring option `-m %s' ", program_name, optarg); (void)fprintf(stderr, "(no libsmi support)\n"); #endif case 'O': Oflag = 0; break; case 'p': ++pflag; break; case 'q': ++qflag; break; case 'r': RFileName = optarg; break; case 'R': Rflag = 0; break; case 's': { char *end; snaplen = strtol(optarg, &end, 0); if (optarg == end || *end != '\0' || snaplen < 0 || snaplen > 65535) error("invalid snaplen %s", optarg); else if (snaplen == 0) snaplen = 65535; 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 if (strcasecmp(optarg, "snmp") == 0) packettype = PT_SNMP; else if (strcasecmp(optarg, "cnfp") == 0) packettype = PT_CNFP; else error("unknown packet type `%s'", optarg); break; case 'u': ++uflag; break; case 'v': ++vflag; break; case 'w': WFileName = optarg; break; case 'x': ++xflag; break; case 'X': ++xflag; ++Xflag; break; #ifdef YYDEBUG case 'Y': { /* Undocumented flag */ extern int yydebug; yydebug = 1; } break; #endif 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); } *ebuf = '\0'; pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf); if (pd == NULL) error("%s", ebuf); else if (*ebuf) warning("%s", ebuf); if (Lflag) { show_dlts_and_exit(pd); } if (dlt >= 0) { if (pcap_set_datalink(pd, dlt) < 0) error("%s", pcap_geterr(pd)); (void)fprintf(stderr, "%s: data link type %s\n", program_name, dlt_name); (void)fflush(stderr); } 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)); if (Cflag != 0) { printer = dump_and_trunc; dumpinfo.WFileName = WFileName; dumpinfo.pd = pd; dumpinfo.p = p; pcap_userdata = (u_char *)&dumpinfo; } else { printer = pcap_dump; pcap_userdata = (u_char *)p; } } else { printer = lookup_printer(pcap_datalink(pd)); pcap_userdata = 0; #ifdef SIGINFO (void)setsignal(SIGINFO, requestinfo); #endif } 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)); cleanup(0); pcap_close(pd); exit(1); } if (RFileName == NULL) info(1); pcap_close(pd); exit(0); } /* make a clean exit on interrupts */ static RETSIGTYPE cleanup(int signo) { /* Can't print the summary if reading from a savefile */ if (pd != NULL && pcap_file(pd) == NULL) { (void)fflush(stdout); putc('\n', stderr); info(1); } if (signo) exit(0); } void info(register int verbose) { struct pcap_stat stat; if (pcap_stats(pd, &stat) < 0) { (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd)); return; } if (!verbose) fprintf(stderr, "%s: ", program_name); (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv); if (!verbose) fputs(", ", stderr); else putc('\n', stderr); (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop); infoprint = 0; } static void reverse(char *s) { int i, j, c; for (i = 0, j = strlen(s) - 1; i < j; i++, j--) { c = s[i]; s[i] = s[j]; s[j] = c; } } static void swebitoa(unsigned int n, char *s) { unsigned int i; i = 0; do { s[i++] = n % 10 + '0'; } while ((n /= 10) > 0); s[i] = '\0'; reverse(s); } static void dump_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp) { struct dump_info *info; static uint cnt = 2; char *name; info = (struct dump_info *)user; /* * XXX - this won't prevent capture files from getting * larger than Cflag - the last packet written to the * file could put it over Cflag. */ if (ftell((FILE *)info->p) > Cflag) { name = (char *) malloc(strlen(info->WFileName) + 4); if (name == NULL) error("dump_and_trunc: malloc"); strcpy(name, info->WFileName); swebitoa(cnt, name + strlen(info->WFileName)); cnt++; pcap_dump_close(info->p); info->p = pcap_dump_open(info->pd, name); free(name); if (info->p == NULL) error("%s", pcap_geterr(pd)); } pcap_dump((u_char *)info->p, h, sp); } /* 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; if (Xflag) { ascii_print(cp, length); return; } 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. */ void default_print(register const u_char *bp, register u_int length) { default_print_unaligned(bp, length); } #ifdef SIGINFO RETSIGTYPE requestinfo(int signo) { if (infodelay) ++infoprint; else info(0); } #endif static 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 [-aAdeflLnNOpqRStuvxX] [ -D datalinktype ] [ -c count ] [ -C file_size ]\n", program_name); (void)fprintf(stderr, "\t\t[ -F file ] [ -i interface ] [ -r file ] [ -s snaplen ]\n"); (void)fprintf(stderr, "\t\t[ -T type ] [ -w file ] [ -E algo:secret ] [ expression ]\n"); exit(1); }