/* * 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 */ #ifndef lint static const char copyright[] _U_ = "@(#) 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[] _U_ = "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.283 2008-09-25 21:45:50 guy 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #ifdef WIN32 #include "getopt.h" #include "w32_fzs.h" extern int strcasecmp (const char *__s1, const char *__s2); extern int SIZE_BUF; #define off_t long #define uint UINT #endif /* WIN32 */ #ifdef HAVE_SMI_H #include #endif #include #include #include #include #include #include #ifndef WIN32 #include #include #include #include #include #endif /* WIN32 */ #include "netdissect.h" #include "interface.h" #include "addrtoname.h" #include "machdep.h" #include "setsignal.h" #include "gmt2local.h" #include "pcap-missing.h" #ifndef NAME_MAX #define NAME_MAX 255 #endif netdissect_options Gndo; netdissect_options *gndo = &Gndo; int dflag; /* print filter code */ int Lflag; /* list available data link types and exit */ char *zflag = NULL; /* compress each savefile using a specified command (like gzip or bzip2) */ static int infodelay; static int infoprint; char *program_name; int32_t thiszone; /* seconds offset from gmt to local time */ /* Forwards */ static RETSIGTYPE cleanup(int); static RETSIGTYPE child_cleanup(int); static void usage(void) __attribute__((noreturn)); static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn)); static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *); static void ndo_default_print(netdissect_options *, const u_char *, u_int); 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 *); static void droproot(const char *, const char *); static void ndo_error(netdissect_options *ndo, const char *fmt, ...); static void ndo_warning(netdissect_options *ndo, const char *fmt, ...); #ifdef SIGINFO RETSIGTYPE requestinfo(int); #endif #if defined(USE_WIN32_MM_TIMER) #include static UINT timer_id; static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR); #elif defined(HAVE_ALARM) static void verbose_stats_dump(int sig); #endif static void info(int); static u_int packets_captured; typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *); typedef u_int (*if_ndo_printer)(struct netdissect_options *ndo, const struct pcap_pkthdr *, const u_char *); struct printer { if_printer f; int type; }; struct ndo_printer { if_ndo_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 { 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 }, #ifdef DLT_SLIP_BSDOS { sl_bsdos_if_print, DLT_SLIP_BSDOS }, #endif { ppp_if_print, DLT_PPP }, #ifdef DLT_PPP_WITHDIRECTION { ppp_if_print, DLT_PPP_WITHDIRECTION }, #endif #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 { 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 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H) { pflog_if_print, DLT_PFLOG }, #endif #ifdef DLT_FR { fr_if_print, DLT_FR }, #endif #ifdef DLT_FRELAY { fr_if_print, DLT_FRELAY }, #endif #ifdef DLT_SUNATM { sunatm_if_print, DLT_SUNATM }, #endif #ifdef DLT_IP_OVER_FC { ipfc_if_print, DLT_IP_OVER_FC }, #endif #ifdef DLT_PRISM_HEADER { prism_if_print, DLT_PRISM_HEADER }, #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 #ifdef DLT_SYMANTEC_FIREWALL { symantec_if_print, DLT_SYMANTEC_FIREWALL }, #endif #ifdef DLT_APPLE_IP_OVER_IEEE1394 { ap1394_if_print, DLT_APPLE_IP_OVER_IEEE1394 }, #endif #ifdef DLT_IEEE802_11_RADIO_AVS { ieee802_11_radio_avs_if_print, DLT_IEEE802_11_RADIO_AVS }, #endif #ifdef DLT_JUNIPER_ATM1 { juniper_atm1_print, DLT_JUNIPER_ATM1 }, #endif #ifdef DLT_JUNIPER_ATM2 { juniper_atm2_print, DLT_JUNIPER_ATM2 }, #endif #ifdef DLT_JUNIPER_MFR { juniper_mfr_print, DLT_JUNIPER_MFR }, #endif #ifdef DLT_JUNIPER_MLFR { juniper_mlfr_print, DLT_JUNIPER_MLFR }, #endif #ifdef DLT_JUNIPER_MLPPP { juniper_mlppp_print, DLT_JUNIPER_MLPPP }, #endif #ifdef DLT_JUNIPER_PPPOE { juniper_pppoe_print, DLT_JUNIPER_PPPOE }, #endif #ifdef DLT_JUNIPER_PPPOE_ATM { juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM }, #endif #ifdef DLT_JUNIPER_GGSN { juniper_ggsn_print, DLT_JUNIPER_GGSN }, #endif #ifdef DLT_JUNIPER_ES { juniper_es_print, DLT_JUNIPER_ES }, #endif #ifdef DLT_JUNIPER_MONITOR { juniper_monitor_print, DLT_JUNIPER_MONITOR }, #endif #ifdef DLT_JUNIPER_SERVICES { juniper_services_print, DLT_JUNIPER_SERVICES }, #endif #ifdef DLT_JUNIPER_ETHER { juniper_ether_print, DLT_JUNIPER_ETHER }, #endif #ifdef DLT_JUNIPER_PPP { juniper_ppp_print, DLT_JUNIPER_PPP }, #endif #ifdef DLT_JUNIPER_FRELAY { juniper_frelay_print, DLT_JUNIPER_FRELAY }, #endif #ifdef DLT_JUNIPER_CHDLC { juniper_chdlc_print, DLT_JUNIPER_CHDLC }, #endif #ifdef DLT_MFR { mfr_if_print, DLT_MFR }, #endif #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H) { bt_if_print, DLT_BLUETOOTH_HCI_H4_WITH_PHDR}, #endif #ifdef HAVE_PCAP_USB_H #ifdef DLT_USB_LINUX { usb_linux_48_byte_print, DLT_USB_LINUX}, #endif /* DLT_USB_LINUX */ #ifdef DLT_USB_LINUX_MMAPPED { usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED}, #endif /* DLT_USB_LINUX_MMAPPED */ #endif /* HAVE_PCAP_USB_H */ #ifdef DLT_IPV4 { raw_if_print, DLT_IPV4 }, #endif #ifdef DLT_IPV6 { raw_if_print, DLT_IPV6 }, #endif { NULL, 0 }, }; static struct ndo_printer ndo_printers[] = { #ifdef DLT_IPNET { ipnet_if_print, DLT_IPNET }, #endif { NULL, 0 }, }; static if_printer lookup_printer(int type) { struct printer *p; for (p = printers; p->f; ++p) if (type == p->type) return p->f; return NULL; /* NOTREACHED */ } static if_ndo_printer lookup_ndo_printer(int type) { struct ndo_printer *p; for (p = ndo_printers; p->f; ++p) if (type == p->type) return p->f; return NULL; /* NOTREACHED */ } static pcap_t *pd; static int supports_monitor_mode; extern int optind; extern int opterr; extern char *optarg; struct print_info { netdissect_options *ndo; union { if_printer printer; if_ndo_printer ndo_printer; } p; int ndo_type; }; struct dump_info { char *WFileName; char *CurrentFileName; pcap_t *pd; pcap_dumper_t *p; }; static void show_dlts_and_exit(const char *device, 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."); /* * If the interface is known to support monitor mode, indicate * whether these are the data link types available when not in * monitor mode, if -I wasn't specified, or when in monitor mode, * when -I was specified (the link-layer types available in * monitor mode might be different from the ones available when * not in monitor mode). */ if (supports_monitor_mode) (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n", device, Iflag ? "when in monitor mode" : "when not in monitor mode"); else (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n", device); while (--n_dlts >= 0) { dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]); if (dlt_name != NULL) { (void) fprintf(stderr, " %s (%s)", dlt_name, pcap_datalink_val_to_description(dlts[n_dlts])); /* * OK, does tcpdump handle that type? */ if (lookup_printer(dlts[n_dlts]) == NULL && lookup_ndo_printer(dlts[n_dlts]) == NULL) (void) fprintf(stderr, " (printing not supported)"); putchar('\n'); } else { (void) fprintf(stderr, " DLT %d (printing 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. */ #if defined(HAVE_PCAP_CREATE) || defined(WIN32) #define B_FLAG "B:" #define B_FLAG_USAGE " [ -B size ]" #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */ #define B_FLAG #define B_FLAG_USAGE #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */ #ifdef HAVE_PCAP_CREATE #define I_FLAG "I" #else /* HAVE_PCAP_CREATE */ #define I_FLAG #endif /* HAVE_PCAP_CREATE */ #ifdef HAVE_PCAP_FINDALLDEVS #ifndef HAVE_PCAP_IF_T #undef HAVE_PCAP_FINDALLDEVS #endif #endif #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 #ifndef WIN32 /* Drop root privileges and chroot if necessary */ static void droproot(const char *username, const char *chroot_dir) { struct passwd *pw = NULL; if (chroot_dir && !username) { fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n"); exit(1); } pw = getpwnam(username); if (pw) { if (chroot_dir) { if (chroot(chroot_dir) != 0 || chdir ("/") != 0) { fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n", chroot_dir, pcap_strerror(errno)); exit(1); } } if (initgroups(pw->pw_name, pw->pw_gid) != 0 || setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) { fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n", username, (unsigned long)pw->pw_uid, (unsigned long)pw->pw_gid, pcap_strerror(errno)); exit(1); } } else { fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n", username); exit(1); } } #endif /* WIN32 */ static int getWflagChars(int x) { int c = 0; x -= 1; while (x > 0) { c += 1; x /= 10; } return c; } static void MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars) { char *filename = malloc(NAME_MAX + 1); /* Process with strftime if Gflag is set. */ if (Gflag != 0) { struct tm *local_tm; /* Convert Gflag_time to a usable format */ if ((local_tm = localtime(&Gflag_time)) == NULL) { error("MakeTimedFilename: localtime"); } /* There's no good way to detect an error in strftime since a return * value of 0 isn't necessarily failure. */ strftime(filename, NAME_MAX, orig_name, local_tm); } else { strncpy(filename, orig_name, NAME_MAX); } if (cnt == 0 && max_chars == 0) strncpy(buffer, filename, NAME_MAX + 1); else if (snprintf(buffer, NAME_MAX + 1, "%s%0*d", filename, max_chars, cnt) > NAME_MAX) /* Report an error if the filename is too large */ error("too many output files or filename is too long (> %d)", NAME_MAX); free(filename); } static int tcpdump_printf(netdissect_options *ndo _U_, const char *fmt, ...) { va_list args; int ret; va_start(args, fmt); ret=vfprintf(stdout, fmt, args); va_end(args); return ret; } 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 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]; char *username = NULL; char *chroot_dir = NULL; #ifdef HAVE_PCAP_FINDALLDEVS pcap_if_t *devpointer; int devnum; #endif int status; #ifdef WIN32 if(wsockinit() != 0) return 1; #endif /* WIN32 */ gndo->ndo_Oflag=1; gndo->ndo_Rflag=1; gndo->ndo_dlt=-1; gndo->ndo_default_print=ndo_default_print; gndo->ndo_printf=tcpdump_printf; gndo->ndo_error=ndo_error; gndo->ndo_warning=ndo_warning; gndo->ndo_snaplen = DEFAULT_SNAPLEN; 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, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:G:i:" I_FLAG "KlLm:M:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:Yz:Z:")) != -1) switch (op) { case 'a': /* compatibility for old -a */ break; case 'A': ++Aflag; break; case 'b': ++bflag; break; #if defined(HAVE_PCAP_CREATE) || defined(WIN32) case 'B': Bflag = atoi(optarg)*1024; if (Bflag <= 0) error("invalid packet buffer size %s", optarg); break; #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */ 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; #ifdef HAVE_PCAP_FINDALLDEVS case 'D': if (pcap_findalldevs(&devpointer, ebuf) < 0) error("%s", ebuf); else { for (i = 0; devpointer != 0; i++) { printf("%d.%s", i+1, devpointer->name); if (devpointer->description != NULL) printf(" (%s)", devpointer->description); printf("\n"); devpointer = devpointer->next; } } return 0; #endif /* HAVE_PCAP_FINDALLDEVS */ case 'L': Lflag++; break; case 'e': ++eflag; break; case 'E': #ifndef HAVE_LIBCRYPTO warning("crypto code not compiled in"); #endif gndo->ndo_espsecret = optarg; break; case 'f': ++fflag; break; case 'F': infile = optarg; break; case 'G': Gflag = atoi(optarg); if (Gflag < 0) error("invalid number of seconds %s", optarg); /* We will create one file initially. */ Gflag_count = 0; /* Grab the current time for rotation use. */ if ((Gflag_time = time(NULL)) == (time_t)-1) { error("main: can't get current time: %s", pcap_strerror(errno)); } break; case 'i': if (optarg[0] == '0' && optarg[1] == 0) error("Invalid adapter index"); #ifdef HAVE_PCAP_FINDALLDEVS /* * If the argument is a number, treat it as * an index into the list of adapters, as * printed by "tcpdump -D". * * This should be OK on UNIX systems, as interfaces * shouldn't have names that begin with digits. * It can be useful on Windows, where more than * one interface can have the same name. */ if ((devnum = atoi(optarg)) != 0) { if (devnum < 0) error("Invalid adapter index"); if (pcap_findalldevs(&devpointer, ebuf) < 0) error("%s", ebuf); else { /* * Look for the devnum-th entry * in the list of devices * (1-based). */ for (i = 0; i < devnum-1 && devpointer != NULL; i++, devpointer = devpointer->next) ; if (devpointer == NULL) error("Invalid adapter index"); } device = devpointer->name; break; } #endif /* HAVE_PCAP_FINDALLDEVS */ device = optarg; break; #ifdef HAVE_PCAP_CREATE case 'I': ++Iflag; break; #endif /* HAVE_PCAP_CREATE */ case 'l': #ifdef WIN32 /* * _IOLBF is the same as _IOFBF in Microsoft's C * libraries; the only alternative they offer * is _IONBF. * * XXX - this should really be checking for MSVC++, * not WIN32, if, for example, MinGW has its own * C library that is more UNIX-compatible. */ setvbuf(stdout, NULL, _IONBF, 0); #else /* WIN32 */ #ifdef HAVE_SETLINEBUF setlinebuf(stdout); #else setvbuf(stdout, NULL, _IOLBF, 0); #endif #endif /* WIN32 */ break; case 'K': ++Kflag; 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 break; case 'M': /* TCP-MD5 shared secret */ #ifndef HAVE_LIBCRYPTO warning("crypto code not compiled in"); #endif sigsecret = optarg; break; case 'n': ++nflag; break; case 'N': ++Nflag; break; case 'O': Oflag = 0; break; case 'p': ++pflag; break; case 'q': ++qflag; ++suppress_default_print; 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 > MAXIMUM_SNAPLEN) error("invalid snaplen %s", optarg); else if (snaplen == 0) snaplen = MAXIMUM_SNAPLEN; 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 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; case 'u': ++uflag; break; #ifdef HAVE_PCAP_DUMP_FLUSH case 'U': ++Uflag; break; #endif case 'v': ++vflag; break; case 'w': WFileName = optarg; break; case 'W': Wflag = atoi(optarg); if (Wflag < 0) error("invalid number of output files %s", optarg); WflagChars = getWflagChars(Wflag); break; case 'x': ++xflag; ++suppress_default_print; break; case 'X': ++Xflag; ++suppress_default_print; break; case 'y': gndo->ndo_dltname = optarg; gndo->ndo_dlt = pcap_datalink_name_to_val(gndo->ndo_dltname); if (gndo->ndo_dlt < 0) error("invalid data link type %s", gndo->ndo_dltname); break; #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG) case 'Y': { /* Undocumented flag */ #ifdef HAVE_PCAP_DEBUG extern int pcap_debug; pcap_debug = 1; #else extern int yydebug; yydebug = 1; #endif } break; #endif case 'z': if (optarg) { zflag = strdup(optarg); } else { usage(); /* NOTREACHED */ } break; case 'Z': if (optarg) { username = strdup(optarg); } else { usage(); /* NOTREACHED */ } break; default: usage(); /* NOTREACHED */ } switch (tflag) { case 0: /* Default */ case 4: /* Default + Date*/ thiszone = gmt2local(0); break; case 1: /* No time stamp */ case 2: /* Unix timeval style */ case 3: /* Microseconds since previous packet */ case 5: /* Microseconds since first packet */ break; default: /* Not supported */ error("only -t, -tt, -ttt, -tttt and -ttttt are supported"); break; } #ifdef WITH_CHROOT /* if run as root, prepare for chrooting */ if (getuid() == 0 || geteuid() == 0) { /* future extensibility for cmd-line arguments */ if (!chroot_dir) chroot_dir = WITH_CHROOT; } #endif #ifdef WITH_USER /* if run as root, prepare for dropping root privileges */ if (getuid() == 0 || geteuid() == 0) { /* Run with '-Z root' to restore old behaviour */ if (!username) username = WITH_USER; } #endif if (RFileName != NULL) { int dlt; const char *dlt_name; #ifndef WIN32 /* * 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). */ if (setgid(getgid()) != 0 || setuid(getuid()) != 0 ) fprintf(stderr, "Warning: setgid/setuid failed !\n"); #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) { fprintf(stderr, "reading from file %s, link-type %u\n", RFileName, dlt); } else { fprintf(stderr, "reading from file %s, link-type %s (%s)\n", RFileName, dlt_name, pcap_datalink_val_to_description(dlt)); } 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); } #ifdef WIN32 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char { //a Unicode string has a \0 as second byte (so strlen() is 1) 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 */ #ifdef HAVE_PCAP_CREATE pd = pcap_create(device, ebuf); if (pd == NULL) error("%s", ebuf); /* * Is this an interface that supports monitor mode? */ if (pcap_can_set_rfmon(pd) == 1) supports_monitor_mode = 1; else supports_monitor_mode = 0; status = pcap_set_snaplen(pd, snaplen); if (status != 0) error("%s: pcap_set_snaplen failed: %s", device, pcap_statustostr(status)); status = pcap_set_promisc(pd, !pflag); if (status != 0) error("%s: pcap_set_promisc failed: %s", device, pcap_statustostr(status)); if (Iflag) { status = pcap_set_rfmon(pd, 1); if (status != 0) error("%s: pcap_set_rfmon failed: %s", device, pcap_statustostr(status)); } status = pcap_set_timeout(pd, 1000); if (status != 0) error("%s: pcap_set_timeout failed: %s", device, pcap_statustostr(status)); if (Bflag != 0) { status = pcap_set_buffer_size(pd, Bflag); if (status != 0) error("%s: pcap_set_buffer_size failed: %s", device, pcap_statustostr(status)); } status = pcap_activate(pd); if (status < 0) { /* * pcap_activate() failed. */ cp = pcap_geterr(pd); if (status == PCAP_ERROR) error("%s", cp); else if ((status == PCAP_ERROR_NO_SUCH_DEVICE || status == PCAP_ERROR_PERM_DENIED) && *cp != '\0') error("%s: %s\n(%s)", device, pcap_statustostr(status), cp); else error("%s: %s", device, pcap_statustostr(status)); } else if (status > 0) { /* * pcap_activate() succeeded, but it's warning us * of a problem it had. */ cp = pcap_geterr(pd); if (status == PCAP_WARNING) warning("%s", cp); else if (status == PCAP_WARNING_PROMISC_NOTSUP && *cp != '\0') warning("%s: %s\n(%s)", device, pcap_statustostr(status), cp); else warning("%s: %s", device, pcap_statustostr(status)); } #else *ebuf = '\0'; pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf); if (pd == NULL) error("%s", ebuf); else if (*ebuf) warning("%s", ebuf); #endif /* HAVE_PCAP_CREATE */ /* * Let user own process after socket has been opened. */ #ifndef WIN32 if (setgid(getgid()) != 0 || setuid(getuid()) != 0) fprintf(stderr, "Warning: setgid/setuid failed !\n"); #endif /* WIN32 */ #if !defined(HAVE_PCAP_CREATE) && defined(WIN32) if(Bflag != 0) if(pcap_setbuff(pd, Bflag)==-1){ error("%s", pcap_geterr(pd)); } #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */ if (Lflag) show_dlts_and_exit(device, pd); if (gndo->ndo_dlt >= 0) { #ifdef HAVE_PCAP_SET_DATALINK if (pcap_set_datalink(pd, gndo->ndo_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 (gndo->ndo_dlt != pcap_datalink(pd)) { error("%s is not one of the DLTs supported by this device\n", gndo->ndo_dltname); } #endif (void)fprintf(stderr, "%s: data link type %s\n", program_name, gndo->ndo_dltname); (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); } } 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)); free(cmdbuf); if (dflag) { bpf_dump(&fcode, dflag); pcap_close(pd); exit(0); } init_addrtoname(localnet, netmask); init_checksum(); #ifndef WIN32 (void)setsignal(SIGPIPE, cleanup); (void)setsignal(SIGTERM, cleanup); (void)setsignal(SIGINT, cleanup); (void)setsignal(SIGCHLD, child_cleanup); #endif /* WIN32 */ /* Cooperate with nohup(1) */ #ifndef WIN32 if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL) (void)setsignal(SIGHUP, oldhandler); #endif /* WIN32 */ if (pcap_setfilter(pd, &fcode) < 0) error("%s", pcap_geterr(pd)); if (WFileName) { pcap_dumper_t *p; /* Do not exceed the default NAME_MAX for files. */ dumpinfo.CurrentFileName = (char *)malloc(NAME_MAX + 1); if (dumpinfo.CurrentFileName == NULL) error("malloc of dumpinfo.CurrentFileName"); /* We do not need numbering for dumpfiles if Cflag isn't set. */ if (Cflag != 0) MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars); else MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0); p = pcap_dump_open(pd, dumpinfo.CurrentFileName); if (p == NULL) error("%s", pcap_geterr(pd)); if (Cflag != 0 || Gflag != 0) { callback = dump_packet_and_trunc; dumpinfo.WFileName = WFileName; dumpinfo.pd = pd; dumpinfo.p = p; pcap_userdata = (u_char *)&dumpinfo; } else { callback = dump_packet; pcap_userdata = (u_char *)p; } } else { type = pcap_datalink(pd); printinfo.ndo_type = 1; printinfo.ndo = gndo; printinfo.p.ndo_printer = lookup_ndo_printer(type); if (printinfo.p.ndo_printer == NULL) { printinfo.p.printer = lookup_printer(type); printinfo.ndo_type = 0; if (printinfo.p.printer == NULL) { gndo->ndo_dltname = pcap_datalink_val_to_name(type); if (gndo->ndo_dltname != NULL) error("packet printing is not supported for link type %s: use -w", gndo->ndo_dltname); else error("packet printing is not supported for link type %d: use -w", type); } } callback = print_packet; pcap_userdata = (u_char *)&printinfo; } #ifndef WIN32 /* * We cannot do this earlier, because we want to be able to open * the file (if done) for writing before giving up permissions. */ if (getuid() == 0 || geteuid() == 0) { if (username || chroot_dir) droproot(username, chroot_dir); } #endif /* WIN32 */ #ifdef SIGINFO /* * We can't get statistics when reading from a file rather * than capturing from a device. */ if (RFileName == NULL) (void)setsignal(SIGINFO, requestinfo); #endif if (vflag > 0 && WFileName) { /* * When capturing to a file, "-v" means tcpdump should, * every 10 secodns, "v"erbosely report the number of * packets captured. */ #ifdef USE_WIN32_MM_TIMER /* call verbose_stats_dump() each 1000 +/-100msec */ timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC); setvbuf(stderr, NULL, _IONBF, 0); #elif defined(HAVE_ALARM) (void)setsignal(SIGALRM, verbose_stats_dump); alarm(1); #endif } #ifndef WIN32 if (RFileName == NULL) { 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) { (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n", device, dlt, snaplen); } else { (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n", device, dlt_name, pcap_datalink_val_to_description(dlt), snaplen); } (void)fflush(stderr); } #endif /* WIN32 */ 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)); } if (RFileName == NULL) { /* * We're doing a live capture. Report the capture * statistics. */ info(1); } pcap_close(pd); exit(status == -1 ? 1 : 0); } /* make a clean exit on interrupts */ static RETSIGTYPE cleanup(int signo _U_) { #ifdef USE_WIN32_MM_TIMER if (timer_id) timeKillEvent(timer_id); timer_id = 0; #elif defined(HAVE_ALARM) alarm(0); #endif #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); info(1); } exit(0); #endif } /* On windows, we do not use a fork, so we do not care less about waiting a child processes to die */ #ifndef WIN32 static RETSIGTYPE child_cleanup(int signo _U_) { wait(NULL); } #endif /* WIN32 */ static void info(register int verbose) { struct pcap_stat stat; /* * Older versions of libpcap didn't set ps_ifdrop on some * platforms; initialize it to 0 to handle that. */ stat.ps_ifdrop = 0; if (pcap_stats(pd, &stat) < 0) { (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd)); infoprint = 0; return; } 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, "%u packets received by filter", stat.ps_recv); if (!verbose) fputs(", ", stderr); else putc('\n', stderr); (void)fprintf(stderr, "%u packets dropped by kernel", stat.ps_drop); if (stat.ps_ifdrop != 0) { if (!verbose) fputs(", ", stderr); else putc('\n', stderr); (void)fprintf(stderr, "%u packets dropped by interface\n", stat.ps_ifdrop); } else putc('\n', stderr); infoprint = 0; } #ifndef WIN32 static void compress_savefile(const char *filename) { if (fork()) return; /* * Set to lowest priority so that this doesn't disturb the capture */ #ifdef NZERO setpriority(PRIO_PROCESS, 0, NZERO - 1); #else setpriority(PRIO_PROCESS, 0, 19); #endif if (execlp(zflag, zflag, filename, (char *)NULL) == -1) fprintf(stderr, "compress_savefile:execlp(%s, %s): %s\n", zflag, filename, strerror(errno)); } #else /* WIN32 */ static void compress_savefile(const char *filename) { fprintf(stderr, "compress_savefile failed. Functionality not implemented under windows\n"); } #endif /* WIN32 */ static void dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp) { struct dump_info *dump_info; ++packets_captured; ++infodelay; dump_info = (struct dump_info *)user; /* * XXX - this won't force the file to rotate on the specified time * boundary, but it will rotate on the first packet received after the * specified Gflag number of seconds. Note: if a Gflag time boundary * and a Cflag size boundary coincide, the time rotation will occur * first thereby cancelling the Cflag boundary (since the file should * be 0). */ if (Gflag != 0) { /* Check if it is time to rotate */ time_t t; /* Get the current time */ if ((t = time(NULL)) == (time_t)-1) { error("dump_and_trunc_packet: can't get current_time: %s", pcap_strerror(errno)); } /* If the time is greater than the specified window, rotate */ if (t - Gflag_time >= Gflag) { /* Update the Gflag_time */ Gflag_time = t; /* Update Gflag_count */ Gflag_count++; /* * Close the current file and open a new one. */ pcap_dump_close(dump_info->p); /* * Compress the file we just closed, if the user asked for it */ if (zflag != NULL) compress_savefile(dump_info->CurrentFileName); /* * Check to see if we've exceeded the Wflag (when * not using Cflag). */ if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) { (void)fprintf(stderr, "Maximum file limit reached: %d\n", Wflag); exit(0); /* NOTREACHED */ } if (dump_info->CurrentFileName != NULL) free(dump_info->CurrentFileName); /* Allocate space for max filename + \0. */ dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1); if (dump_info->CurrentFileName == NULL) error("dump_packet_and_trunc: malloc"); /* * This is always the first file in the Cflag * rotation: e.g. 0 * We also don't need numbering if Cflag is not set. */ if (Cflag != 0) MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, WflagChars); else MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0); dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName); if (dump_info->p == NULL) error("%s", pcap_geterr(pd)); } } /* * 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 (Cflag != 0 && pcap_dump_ftell(dump_info->p) > Cflag) { /* * Close the current file and open a new one. */ pcap_dump_close(dump_info->p); /* * Compress the file we just closed, if the user asked for it */ if (zflag != NULL) compress_savefile(dump_info->CurrentFileName); Cflag_count++; if (Wflag > 0) { if (Cflag_count >= Wflag) Cflag_count = 0; } if (dump_info->CurrentFileName != NULL) free(dump_info->CurrentFileName); dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1); if (dump_info->CurrentFileName == NULL) error("dump_packet_and_trunc: malloc"); MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars); dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName); if (dump_info->p == NULL) error("%s", pcap_geterr(pd)); } 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) info(0); } 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; if(print_info->ndo_type) { hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp); } else { hdrlen = (*print_info->p.printer)(h, sp); } if (Xflag) { /* * Print the raw packet data in hex and ASCII. */ if (Xflag > 1) { /* * Include the link-layer header. */ hex_and_ascii_print("\n\t", 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) hex_and_ascii_print("\n\t", sp + hdrlen, h->caplen - hdrlen); } } else if (xflag) { /* * Print the raw packet data in hex. */ if (xflag > 1) { /* * Include the link-layer header. */ hex_print("\n\t", 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) hex_print("\n\t", sp + hdrlen, h->caplen - hdrlen); } } else if (Aflag) { /* * Print the raw packet data in ASCII. */ if (Aflag > 1) { /* * Include the link-layer header. */ ascii_print(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) ascii_print(sp + hdrlen, h->caplen - hdrlen); } } putchar('\n'); --infodelay; if (infoprint) info(0); } #ifdef WIN32 /* * XXX - there should really be libpcap calls to get the version * number as a string (the string would be generated from #defines * at run time, so that it's not generated from string constants * in the library, as, on many UNIX systems, those constants would * be statically linked into the application executable image, and * would thus reflect the version of libpcap on the system on * which the application was *linked*, not the system on which it's * *running*. * * That routine should be documented, unlike the "version[]" * string, so that UNIX vendors providing their own libpcaps * don't omit it (as a couple of vendors have...). * * Packet.dll should perhaps also export a routine to return the * version number of the Packet.dll code, to supply the * "Wpcap_version" information on Windows. */ char WDversion[]="current-cvs.tcpdump.org"; #if !defined(HAVE_GENERATED_VERSION) char version[]="current-cvs.tcpdump.org"; #endif char pcap_version[]="current-cvs.tcpdump.org"; char Wpcap_version[]="3.1"; #endif /* * By default, print the specified data out in hex and ASCII. */ static void ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length) { hex_and_ascii_print("\n\t", bp, length); /* pass on lf and identation string */ } void default_print(const u_char *bp, u_int length) { ndo_default_print(gndo, bp, length); } #ifdef SIGINFO RETSIGTYPE requestinfo(int signo _U_) { if (infodelay) ++infoprint; else info(0); } #endif /* * Called once each second in verbose mode while dumping to file */ #ifdef USE_WIN32_MM_TIMER void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_, DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_) { struct pcap_stat stat; if (infodelay == 0 && pcap_stats(pd, &stat) >= 0) fprintf(stderr, "Got %u\r", packets_captured); } #elif defined(HAVE_ALARM) static void verbose_stats_dump(int sig _U_) { struct pcap_stat stat; if (infodelay == 0 && pcap_stats(pd, &stat) >= 0) fprintf(stderr, "Got %u\r", packets_captured); alarm(1); } #endif static void usage(void) { extern char version[]; #ifndef HAVE_PCAP_LIB_VERSION #if defined(WIN32) || defined(HAVE_PCAP_VERSION) extern char pcap_version[]; #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */ static char pcap_version[] = "unknown"; #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */ #endif /* HAVE_PCAP_LIB_VERSION */ #ifdef HAVE_PCAP_LIB_VERSION #ifdef WIN32 (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version); #else /* WIN32 */ (void)fprintf(stderr, "%s version %s\n", program_name, version); #endif /* WIN32 */ (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 /* 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, "Usage: %s [-aAd" D_FLAG "ef" I_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name); (void)fprintf(stderr, "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n"); (void)fprintf(stderr, "\t\t[ -i interface ] [ -M secret ] [ -r file ]\n"); (void)fprintf(stderr, "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ]\n"); (void)fprintf(stderr, "\t\t[ -y datalinktype ] [ -z command ] [ -Z user ]\n"); (void)fprintf(stderr, "\t\t[ expression ]\n"); exit(1); } /* VARARGS */ static void ndo_error(netdissect_options *ndo _U_, const char *fmt, ...) { va_list ap; (void)fprintf(stderr, "%s: ", program_name); va_start(ap, fmt); (void)vfprintf(stderr, fmt, ap); va_end(ap); if (*fmt) { fmt += strlen(fmt); if (fmt[-1] != '\n') (void)fputc('\n', stderr); } exit(1); /* NOTREACHED */ } /* VARARGS */ static void ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...) { va_list ap; (void)fprintf(stderr, "%s: WARNING: ", program_name); va_start(ap, fmt); (void)vfprintf(stderr, fmt, ap); va_end(ap); if (*fmt) { fmt += strlen(fmt); if (fmt[-1] != '\n') (void)fputc('\n', stderr); } }