X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/2a13a72f0960bca64cd28bda9c6c2ee529736364..58b04f7f360c33a8058d0b9a2d1314e34dff8403:/tcpdump.c diff --git a/tcpdump.c b/tcpdump.c index 4fd5c6a7..be016431 100644 --- a/tcpdump.c +++ b/tcpdump.c @@ -30,7 +30,7 @@ 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 1.191 2002-12-19 05:44:47 guy Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.216 2003-11-04 07:29:16 guy Exp $ (LBL)"; #endif /* @@ -62,17 +62,17 @@ extern int SIZE_BUF; #include #include - #include "interface.h" #include "addrtoname.h" #include "machdep.h" #include "setsignal.h" #include "gmt2local.h" +#include "pcap-missing.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 */ @@ -82,19 +82,23 @@ 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; /* "unbuffered" output of dump files */ 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; +static int infodelay; +static int infoprint; char *program_name; @@ -103,7 +107,9 @@ 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 print_packet(u_char *, const struct pcap_pkthdr *, const u_char *); static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *); static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *); @@ -111,16 +117,24 @@ static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *); RETSIGTYPE requestinfo(int); #endif +static void info(int); +static u_int packets_captured; + /* Length of saved portion of packet. */ int snaplen = DEFAULT_SNAPLEN; +typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *); + struct printer { - pcap_handler f; + if_printer f; int type; }; static struct printer printers[] = { { arcnet_if_print, DLT_ARCNET }, +#ifdef DLT_ARCNET_LINUX + { arcnet_linux_if_print, DLT_ARCNET_LINUX }, +#endif { ether_if_print, DLT_EN10MB }, { token_if_print, DLT_IEEE802 }, #ifdef DLT_LANE8023 @@ -133,9 +147,13 @@ static struct printer printers[] = { { cip_if_print, DLT_ATM_CLIP }, #endif { sl_if_print, DLT_SLIP }, +#ifdef DLT_SLIP_BSDOS { sl_bsdos_if_print, DLT_SLIP_BSDOS }, +#endif { ppp_if_print, DLT_PPP }, +#ifdef DLT_PPP_BSDOS { ppp_bsdos_if_print, DLT_PPP_BSDOS }, +#endif { fddi_if_print, DLT_FDDI }, { null_if_print, DLT_NULL }, #ifdef DLT_LOOP @@ -184,11 +202,14 @@ static struct printer printers[] = { #endif #ifdef DLT_IEEE802_11_RADIO { ieee802_11_radio_if_print, DLT_IEEE802_11_RADIO }, +#endif +#ifdef DLT_ENC + { enc_if_print, DLT_ENC }, #endif { NULL, 0 }, }; -static pcap_handler +static if_printer lookup_printer(int type) { struct printer *p; @@ -197,7 +218,7 @@ lookup_printer(int type) if (type == p->type) return p->f; - error("unknown data link type %d", type); + return NULL; /* NOTREACHED */ } @@ -207,23 +228,88 @@ extern int optind; extern int opterr; extern char *optarg; +struct print_info { + if_printer printer; +}; + struct dump_info { char *WFileName; pcap_t *pd; pcap_dumper_t *p; }; +static void +show_dlts_and_exit(pcap_t *pd) +{ + int n_dlts; + int *dlts = 0; + const char *dlt_name; + + 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 -y to set):\n"); + + while (--n_dlts >= 0) { + dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]); + if (dlt_name != NULL) { + (void) fprintf(stderr, " %s", dlt_name); + + /* + * OK, does tcpdump handle that type? + */ + if (lookup_printer(dlts[n_dlts]) == NULL) + (void) fprintf(stderr, " (not supported)"); + putchar('\n'); + } else { + (void) fprintf(stderr, " DLT %d (not supported)\n", + dlts[n_dlts]); + } + } + free(dlts); + exit(0); +} + +/* + * Set up flags that might or might not be supported depending on the + * version of libpcap we're using. + */ +#ifdef WIN32 +#define B_FLAG "B:" +#define B_FLAG_USAGE " [ -B size ]" +#else /* WIN32 */ +#define B_FLAG +#define B_FLAG_USAGE +#endif /* WIN32 */ + +#ifdef HAVE_PCAP_FINDALLDEVS +#define D_FLAG "D" +#else +#define D_FLAG +#endif + +#ifdef HAVE_PCAP_DUMP_FLUSH +#define U_FLAG "U" +#else +#define U_FLAG +#endif + 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; + pcap_handler callback; + int type; struct bpf_program fcode; #ifndef WIN32 RETSIGTYPE (*oldhandler)(int); #endif + struct print_info printinfo; struct dump_info dumpinfo; u_char *pcap_userdata; char ebuf[PCAP_ERRBUF_SIZE]; @@ -231,16 +317,10 @@ main(int argc, char **argv) pcap_if_t *devpointer; int devnum; #endif + int status; #ifdef WIN32 - DWORD dwVersion; - DWORD dwWindowsMajorVersion; - u_int UserBufferSize=1000000; -#endif - -#ifdef WIN32 - dwVersion=GetVersion(); /* get the OS version */ - dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion))); - if(wsockinit()!=0) return 1; + u_int UserBufferSize = 1000000; + if(wsockinit() != 0) return 1; #endif /* WIN32 */ cnt = -1; @@ -262,26 +342,18 @@ main(int argc, char **argv) opterr = 0; while ( -#ifdef WIN32 - (op = getopt(argc, argv, "aAB:c:C:dDeE:fF:i:lm:nNOpqr:Rs:StT:uvw:xXY")) != -1) -#else /* WIN32 */ -#ifdef HAVE_PCAP_FINDALLDEVS - (op = getopt(argc, argv, "aAc:C:dDeE:fF:i:lm:nNOpqr:Rs:StT:uvw:xXY")) != -1) -#else /* HAVE_PCAP_FINDALLDEVS */ - (op = getopt(argc, argv, "aAc:C:deE:fF:i:lm:nNOpqr:Rs:StT:uvw:xXY")) != -1) -#endif /* HAVE_PCAP_FINDALLDEVS */ -#endif /* WIN32 */ + (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:nNOpqr:Rs:StT:u" U_FLAG "vw:xXy:Y")) != -1) switch (op) { case 'a': - ++aflag; + /* compatibility for old -a */ break; - case 'A': - ++xflag; - ++Xflag; - ++Aflag; - break; + case 'A': + ++xflag; + ++Xflag; + ++Aflag; + break; #ifdef WIN32 case 'B': @@ -323,6 +395,10 @@ main(int argc, char **argv) return 0; #endif /* HAVE_PCAP_FINDALLDEVS */ + case 'L': + Lflag++; + break; + case 'e': ++eflag; break; @@ -460,6 +536,10 @@ main(int argc, char **argv) packettype = PT_SNMP; else if (strcasecmp(optarg, "cnfp") == 0) packettype = PT_CNFP; + else if (strcasecmp(optarg, "tftp") == 0) + packettype = PT_TFTP; + else if (strcasecmp(optarg, "aodv") == 0) + packettype = PT_AODV; else error("unknown packet type `%s'", optarg); break; @@ -468,6 +548,12 @@ main(int argc, char **argv) ++uflag; break; +#ifdef HAVE_PCAP_DUMP_FLUSH + case 'U': + ++Uflag; + break; +#endif + case 'v': ++vflag; break; @@ -485,6 +571,13 @@ main(int argc, char **argv) ++Xflag; break; + case 'y': + dlt_name = optarg; + dlt = pcap_datalink_name_to_val(dlt_name); + if (dlt < 0) + error("invalid data link type %s", dlt_name); + break; + #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG) case 'Y': { @@ -504,25 +597,34 @@ main(int argc, char **argv) /* NOTREACHED */ } - if (aflag && nflag) - error("-a and -n options are incompatible"); - if (tflag > 0) thiszone = gmt2local(0); if (RFileName != NULL) { + int dlt; + const char *dlt_name; + +#ifndef WIN32 /* - * 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. + * We don't need network access, so relinquish any set-UID + * or set-GID privileges we have (if any). + * + * We do *not* want set-UID privileges when opening a + * trace file, as that might let the user read other + * people's trace files (especially if we're set-UID + * root). */ -#ifndef WIN32 setuid(getuid()); #endif /* WIN32 */ - pd = pcap_open_offline(RFileName, ebuf); if (pd == NULL) error("%s", ebuf); + dlt = pcap_datalink(pd); + dlt_name = pcap_datalink_val_to_name(dlt); + if (dlt_name == NULL) + dlt_name = "???"; + printf("reading from file %s, link-type %u (%s)\n", + RFileName, dlt, dlt_name); localnet = 0; netmask = 0; if (fflag != 0) @@ -534,10 +636,22 @@ main(int argc, char **argv) error("%s", ebuf); } #ifdef WIN32 - PrintCapBegins(program_name,device); + if(IsTextUnicode(device, + wcslen((short*)device), // Device always ends with a double \0, so this way to determine its + // length should be always valid + NULL)) + { + fprintf(stderr, "%s: listening on %ws\n", program_name, device); + } + else + { + fprintf(stderr, "%s: listening on %s\n", program_name, device); + } + + fflush(stderr); #endif /* WIN32 */ *ebuf = '\0'; - pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf); + pd = pcap_open_live(device, snaplen, !pflag, 10000, ebuf); if (pd == NULL) error("%s", ebuf); else if (*ebuf) @@ -548,6 +662,27 @@ main(int argc, char **argv) error("%s", pcap_geterr(pd)); } #endif /* WIN32 */ + if (Lflag) + show_dlts_and_exit(pd); + if (dlt >= 0) { +#ifdef HAVE_PCAP_SET_DATALINK + if (pcap_set_datalink(pd, dlt) < 0) + error("%s", pcap_geterr(pd)); +#else + /* + * We don't actually support changing the + * data link type, so we only let them + * set it to what it already is. + */ + if (dlt != pcap_datalink(pd)) { + error("%s is not one of the DLTs supported by this device\n", + dlt_name); + } +#endif + (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); @@ -579,6 +714,9 @@ main(int argc, char **argv) } init_addrtoname(localnet, netmask); +#ifndef WIN32 + (void)setsignal(SIGPIPE, cleanup); +#endif /* WIN32 */ (void)setsignal(SIGTERM, cleanup); (void)setsignal(SIGINT, cleanup); /* Cooperate with nohup(1) */ @@ -594,58 +732,119 @@ main(int argc, char **argv) if (p == NULL) error("%s", pcap_geterr(pd)); if (Cflag != 0) { - printer = dump_packet_and_trunc; + callback = dump_packet_and_trunc; dumpinfo.WFileName = WFileName; dumpinfo.pd = pd; dumpinfo.p = p; pcap_userdata = (u_char *)&dumpinfo; } else { - printer = dump_packet; + callback = dump_packet; pcap_userdata = (u_char *)p; } } else { - printer = lookup_printer(pcap_datalink(pd)); - pcap_userdata = 0; + type = pcap_datalink(pd); + printinfo.printer = lookup_printer(type); + if (printinfo.printer == NULL) { + dlt_name = pcap_datalink_val_to_name(type); + if (dlt_name != NULL) + error("unsupported data link type %s", dlt_name); + else + error("unsupported data link type %d", type); + } + callback = print_packet; + pcap_userdata = (u_char *)&printinfo; } #ifdef SIGINFO (void)setsignal(SIGINFO, requestinfo); #endif #ifndef WIN32 if (RFileName == NULL) { - (void)fprintf(stderr, "%s: listening on %s\n", - program_name, device); + int dlt; + const char *dlt_name; + + if (!vflag && !WFileName) { + (void)fprintf(stderr, + "%s: verbose output suppressed, use -v or -vv for full protocol decode\n", + program_name); + } else + (void)fprintf(stderr, "%s: ", program_name); + dlt = pcap_datalink(pd); + dlt_name = pcap_datalink_val_to_name(dlt); + if (dlt_name == NULL) + dlt_name = "???"; + (void)fprintf(stderr, "listening on %s, link-type %u (%s), capture size %u bytes\n", + device, dlt, dlt_name, snaplen); (void)fflush(stderr); } #endif /* WIN32 */ - if (pcap_loop(pd, cnt, printer, pcap_userdata) < 0) { + status = pcap_loop(pd, cnt, callback, pcap_userdata); + if (WFileName == NULL) { + /* + * We're printing packets. Flush the printed output, + * so it doesn't get intermingled with error output. + */ + if (status == -2) { + /* + * We got interrupted, so perhaps we didn't + * manage to finish a line we were printing. + * Print an extra newline, just in case. + */ + putchar('\n'); + } + (void)fflush(stdout); + } + if (status == -1) { + /* + * Error. Report it. + */ (void)fprintf(stderr, "%s: pcap_loop: %s\n", program_name, pcap_geterr(pd)); - cleanup(0); - pcap_close(pd); - exit(1); } - if (RFileName == NULL) + if (RFileName == NULL) { + /* + * We're doing a live capture. Report the capture + * statistics. + */ info(1); + } pcap_close(pd); - exit(0); + exit(status == -1 ? 1 : 0); } /* make a clean exit on interrupts */ static RETSIGTYPE -cleanup(int signo) +cleanup(int signo _U_) { - - /* Can't print the summary if reading from a savefile */ +#ifdef HAVE_PCAP_BREAKLOOP + /* + * We have "pcap_breakloop()"; use it, so that we do as little + * as possible in the signal handler (it's probably not safe + * to do anything with standard I/O streams in a signal handler - + * the ANSI C standard doesn't say it is). + */ + pcap_breakloop(pd); +#else + /* + * We don't have "pcap_breakloop()"; this isn't safe, but + * it's the best we can do. Print the summary if we're + * not reading from a savefile - i.e., if we're doing a + * live capture - and exit. + */ if (pd != NULL && pcap_file(pd) == NULL) { + /* + * We got interrupted, so perhaps we didn't + * manage to finish a line we were printing. + * Print an extra newline, just in case. + */ + putchar('\n'); (void)fflush(stdout); - putc('\n', stderr); info(1); } - if (signo) - exit(0); + exit(0); +#endif } -void +static void info(register int verbose) { struct pcap_stat stat; @@ -658,6 +857,11 @@ info(register int verbose) if (!verbose) fprintf(stderr, "%s: ", program_name); + (void)fprintf(stderr, "%u packets captured", packets_captured); + if (!verbose) + fputs(", ", stderr); + else + putc('\n', stderr); (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv); if (!verbose) fputs(", ", stderr); @@ -701,6 +905,8 @@ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *s static uint cnt = 2; char *name; + ++packets_captured; + ++infodelay; dump_info = (struct dump_info *)user; @@ -725,6 +931,10 @@ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *s } pcap_dump((u_char *)dump_info->p, h, sp); +#ifdef HAVE_PCAP_DUMP_FLUSH + if (Uflag) + pcap_dump_flush(dump_info->p); +#endif --infodelay; if (infoprint) @@ -734,9 +944,64 @@ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *s static void dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp) { + ++packets_captured; + ++infodelay; pcap_dump(user, h, sp); +#ifdef HAVE_PCAP_DUMP_FLUSH + if (Uflag) + pcap_dump_flush((pcap_dumper_t *)user); +#endif + + --infodelay; + if (infoprint) + info(0); +} + +static void +print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp) +{ + struct print_info *print_info; + u_int hdrlen; + + ++packets_captured; + + ++infodelay; + ts_print(&h->ts); + + print_info = (struct print_info *)user; + + /* + * Some printers want to check that they're not walking off the + * end of the packet. + * Rather than pass it all the way down, we set this global. + */ + snapend = sp + h->caplen; + + hdrlen = (*print_info->printer)(h, sp); + if (xflag) { + /* + * Print the raw packet data. + */ + if (xflag > 1) { + /* + * Include the link-layer header. + */ + default_print_unaligned(sp, h->caplen); + } else { + /* + * Don't include the link-layer header - and if + * we have nothing past the link-layer header, + * print nothing. + */ + if (h->caplen > hdrlen) + default_print_unaligned(sp + hdrlen, + h->caplen - hdrlen); + } + } + + putchar('\n'); --infodelay; if (infoprint) @@ -803,31 +1068,6 @@ default_print(register const u_char *bp, register u_int length) default_print_unaligned(bp, length); } -/* - * By default, print the packet out in hex; if eflag is set, print - * everything, otherwise print everything except for the link-layer - * header. - */ -void -default_print_packet(register const u_char *bp, register u_int length, - u_int hdr_length) -{ - if (xflag > 1) { - /* - * Include the link-layer header. - */ - default_print_unaligned(bp, length); - } else { - /* - * Don't include the link-layer header - and if we have - * nothing past the link-layer header, print nothing. - */ - if (length > hdr_length) - default_print_unaligned(bp + hdr_length, - length - hdr_length); - } -} - #ifdef SIGINFO RETSIGTYPE requestinfo(int signo _U_) { @@ -842,32 +1082,33 @@ static void usage(void) { extern char version[]; +#ifndef HAVE_PCAP_LIB_VERSION #if defined(WIN32) || defined(HAVE_PCAP_VERSION) extern char pcap_version[]; -#else +#else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */ static char pcap_version[] = "unknown"; -#endif +#endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */ +#endif /* HAVE_PCAP_LIB_VERSION */ +#ifdef HAVE_PCAP_LIB_VERSION + (void)fprintf(stderr, "%s version %s\n", program_name, version); + (void)fprintf(stderr, "%s\n", pcap_lib_version()); +#else /* HAVE_PCAP_LIB_VERSION */ #ifdef WIN32 (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version); (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version); -#else +#else /* WIN32 */ (void)fprintf(stderr, "%s version %s\n", program_name, version); (void)fprintf(stderr, "libpcap version %s\n", pcap_version); #endif /* WIN32 */ +#endif /* HAVE_PCAP_LIB_VERSION */ (void)fprintf(stderr, -#ifdef WIN32 -"Usage: %s [-aAdDeflnNOpqRStuvxX] [-B size] [-c count] [ -C file_size ]\n", program_name); -#else /* WIN32 */ -#ifdef HAVE_PCAP_FINDALLDEVS -"Usage: %s [-aAdDeflnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name); -#else /* HAVE_PCAP_FINDALLDEVS */ -"Usage: %s [-aAdeflnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name); -#endif /* HAVE_PCAP_FINDALLDEVS */ -#endif /* WIN32 */ +"Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name); + (void)fprintf(stderr, +"\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n"); (void)fprintf(stderr, -"\t\t[ -F file ] [ -i interface ] [ -r file ] [ -s snaplen ]\n"); +"\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ]\n"); (void)fprintf(stderr, -"\t\t[ -T type ] [ -w file ] [ -E algo:secret ] [ expression ]\n"); +"\t\t[ expression ]\n"); exit(1); }