/* * 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. */ #ifndef lint static const char 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"; static const char rcsid[] = "@(#) $Header: /cvs/OpenBSD/src/usr.sbin/tcpdump/tcpdump.c,v 1.16 2000/03/26 05:24:25 ericj Exp $ (LBL)"; #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 #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 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 Xflag; /* print packet in emacs-hexl style */ 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; }; /* XXX needed if using old bpf.h */ #ifndef DLT_ATM_RFC1483 #define DLT_ATM_RFC1483 11 #endif 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 }, { fddi_if_print, DLT_FDDI }, { null_if_print, DLT_NULL }, { raw_if_print, DLT_RAW }, { atm_if_print, DLT_ATM_RFC1483 }, { null_if_print, DLT_LOOP }, { enc_if_print, DLT_ENC }, { 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:xXY")) != -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 if (strcasecmp(optarg, "cnfp") == 0) packettype = PT_CNFP; else if (strcasecmp(optarg, "sack") == 0) snaplen = SACK_SNAPLEN; 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; case 'X': ++Xflag; if (xflag == 0) ++xflag; break; default: usage(); /* NOTREACHED */ } 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) { warning("%s", ebuf); localnet = 0; netmask = 0; } /* * 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); } /* dump the buffer in `emacs-hexl' style */ void default_print_hexl(const u_char *cp, unsigned int length, unsigned int offset) { unsigned int i, j, jm; int c; char ln[128]; printf("\n"); for (i = 0; i < length; i += 0x10) { snprintf(ln, sizeof(ln), " %04x: ", (unsigned int)(i + offset)); jm = length - i; jm = jm > 16 ? 16 : jm; for (j = 0; j < jm; j++) { if ((j % 2) == 1) snprintf(ln + strlen(ln), sizeof(ln) - strlen(ln), "%02x ", (unsigned int)cp[i+j]); else snprintf(ln + strlen(ln), sizeof(ln) - strlen(ln), "%02x", (unsigned int)cp[i+j]); } for (; j < 16; j++) { if ((j % 2) == 1) snprintf(ln + strlen(ln), sizeof(ln) - strlen(ln), " "); else snprintf(ln + strlen(ln), sizeof(ln) - strlen(ln), " "); } snprintf(ln + strlen(ln), sizeof(ln) - strlen(ln), " "); for (j = 0; j < jm; j++) { c = cp[i+j]; c = isprint(c) ? c : '.'; snprintf(ln + strlen(ln), sizeof(ln) - strlen(ln), "%c", c); } printf("%s\n", ln); } } /* 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) { /* dump the buffer in `emacs-hexl' style */ default_print_hexl(cp, length, 0); } else { /* dump the buffer in old tcpdump style */ 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); } } } 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 (Xflag) { /* dump the buffer in `emacs-hexl' style */ default_print_hexl(bp, length, 0); } else { /* dump the buffer in old tcpdump style */ 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 [-adeflnNOpqStvxX] [-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); }