X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/a0e19c0caef95fdcbace674de91e7c181d3bc866..1f563c19e77e7be5e1a2e3b6336d0475d7530f61:/tcpdump.c diff --git a/tcpdump.c b/tcpdump.c index 6476a3d4..c657707f 100644 --- a/tcpdump.c +++ b/tcpdump.c @@ -38,7 +38,7 @@ #endif /* - * Some older versions of Mac OS X may ship pcap.h from libpcap 0.6 with a + * Some older versions of Mac OS X ship pcap.h from libpcap 0.6 with a * libpcap based on 0.8. That means it has pcap_findalldevs() but the * header doesn't define pcap_if_t, meaning that we can't actually *use* * pcap_findalldevs(). @@ -78,7 +78,9 @@ The Regents of the University of California. All rights reserved.\n"; #endif /* Capsicum-specific code requires macros from , which will fail * to compile if has already been included; including the headers - * in the opposite order works fine. + * in the opposite order works fine. For the most part anyway, because in + * FreeBSD declares bpf_dump() instead of . Thus + * interface.h takes care of it later to avoid a compiler warning. */ #ifdef HAVE_CAPSICUM #include @@ -161,6 +163,8 @@ The Regents of the University of California. All rights reserved.\n"; #include "print.h" +#include "diag-control.h" + #include "fptype.h" #ifndef PATH_MAX @@ -238,10 +242,6 @@ static int infoprint; char *program_name; -#ifdef HAVE_CASPER -cap_channel_t *capdns; -#endif - /* Forwards */ static NORETURN void error(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2); static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2); @@ -433,15 +433,15 @@ show_tstamp_types_and_exit(pcap_t *pc, const char *device) device); exit_tcpdump(S_SUCCESS); } - fprintf(stderr, "Time stamp types for %s (use option -j to set):\n", + fprintf(stdout, "Time stamp types for %s (use option -j to set):\n", device); for (i = 0; i < n_tstamp_types; i++) { tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]); if (tstamp_type_name != NULL) { - (void) fprintf(stderr, " %s (%s)\n", tstamp_type_name, + (void) fprintf(stdout, " %s (%s)\n", tstamp_type_name, pcap_tstamp_type_val_to_description(tstamp_types[i])); } else { - (void) fprintf(stderr, " %d\n", tstamp_types[i]); + (void) fprintf(stdout, " %d\n", tstamp_types[i]); } } pcap_free_tstamp_types(tstamp_types); @@ -470,28 +470,30 @@ show_dlts_and_exit(pcap_t *pc, const char *device) * monitor mode might be different from the ones available when * not in monitor mode). */ + (void) fprintf(stdout, "Data link types for "); if (supports_monitor_mode) - (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n", + (void) fprintf(stdout, "%s %s", 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", + (void) fprintf(stdout, "%s", device); + (void) fprintf(stdout, " (use option -y to set):\n"); for (i = 0; i < n_dlts; i++) { dlt_name = pcap_datalink_val_to_name(dlts[i]); if (dlt_name != NULL) { - (void) fprintf(stderr, " %s (%s)", dlt_name, + (void) fprintf(stdout, " %s (%s)", dlt_name, pcap_datalink_val_to_description(dlts[i])); /* * OK, does tcpdump handle that type? */ if (!has_printer(dlts[i])) - (void) fprintf(stderr, " (printing not supported)"); - fprintf(stderr, "\n"); + (void) fprintf(stdout, " (printing not supported)"); + fprintf(stdout, "\n"); } else { - (void) fprintf(stderr, " DLT %d (printing not supported)\n", + (void) fprintf(stdout, " DLT %d (printing not supported)\n", dlts[i]); } } @@ -806,8 +808,8 @@ droproot(const char *username, const char *chroot_dir) } else error("Couldn't find user '%.32s'", username); #ifdef HAVE_LIBCAP_NG - /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */ -DIAG_OFF_CLANG(assign-enum) + /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT anymore. */ +DIAG_OFF_ASSIGN_ENUM capng_updatev( CAPNG_DROP, CAPNG_EFFECTIVE | CAPNG_PERMITTED, @@ -815,7 +817,7 @@ DIAG_OFF_CLANG(assign-enum) CAP_SETGID, CAP_SYS_CHROOT, -1); -DIAG_ON_CLANG(assign-enum) +DIAG_ON_ASSIGN_ENUM capng_apply(CAPNG_SELECT_BOTH); #endif /* HAVE_LIBCAP_NG */ @@ -843,6 +845,8 @@ MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars) char *filename = malloc(PATH_MAX + 1); if (filename == NULL) error("%s: malloc", __func__); + if (strlen(orig_name) == 0) + error("an empty string is not a valid file name"); /* Process with strftime if Gflag is set. */ if (Gflag != 0) { @@ -854,9 +858,25 @@ MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars) } /* There's no good way to detect an error in strftime since a return - * value of 0 isn't necessarily failure. + * value of 0 isn't necessarily failure; if orig_name is an empty + * string, the formatted string will be empty. + * + * However, the C90 standard says that, if there *is* a + * buffer overflow, the content of the buffer is undefined, + * so we must check for a buffer overflow. + * + * So we check above for an empty orig_name, and only call + * strftime() if it's non-empty, in which case the return + * value will only be 0 if the formatted date doesn't fit + * in the buffer. + * + * (We check above because, even if we don't use -G, we + * want a better error message than "tcpdump: : No such + * file or directory" for this case.) */ - strftime(filename, PATH_MAX, orig_name, local_tm); + if (strftime(filename, PATH_MAX, orig_name, local_tm) == 0) { + error("%s: strftime", __func__); + } } else { strncpy(filename, orig_name, PATH_MAX); } @@ -959,7 +979,7 @@ tstamp_precision_to_string(int precision) * along the lines of ioctl(), the fact that ioctl() operations are * largely specific to particular character devices but fcntl() operations * are either generic to all descriptors or generic to all descriptors for - * regular files nonwithstanding. + * regular files notwithstanding. * * The Capsicum people decided that fine-grained control of descriptor * operations was required, so that you need to grant permission for @@ -1540,6 +1560,13 @@ main(int argc, char **argv) if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0) error("%s", ebuf); + /* + * An explicit tzset() call is usually not needed as it happens + * implicitly the first time we call localtime() or mktime(), + * but in some cases (sandboxing, chroot) this may be too late. + */ + tzset(); + while ( (op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1) switch (op) { @@ -1708,7 +1735,7 @@ main(int argc, char **argv) if (nd_load_smi_module(optarg, ebuf, sizeof(ebuf)) == -1) error("%s", ebuf); } else { - (void)fprintf(stderr, "%s: ignoring option `-m %s' ", + (void)fprintf(stderr, "%s: ignoring option '-m %s' ", program_name, optarg); (void)fprintf(stderr, "(no libsmi support)\n"); } @@ -1752,7 +1779,7 @@ main(int argc, char **argv) else if (ascii_strcasecmp(optarg, "inout") == 0) Qflag = PCAP_D_INOUT; else - error("unknown capture direction `%s'", optarg); + error("unknown capture direction '%s'", optarg); break; #endif /* HAVE_PCAP_SETDIRECTION */ @@ -1818,7 +1845,7 @@ main(int argc, char **argv) else if (ascii_strcasecmp(optarg, "domain") == 0) ndo->ndo_packettype = PT_DOMAIN; else - error("unknown packet type `%s'", optarg); + error("unknown packet type '%s'", optarg); break; case 'u': @@ -1951,14 +1978,6 @@ main(int argc, char **argv) show_remote_devices_and_exit(); #endif -#if defined(DLT_LINUX_SLL2) && defined(HAVE_PCAP_SET_DATALINK) -/* Set default linktype DLT_LINUX_SLL2 when capturing on the "any" device */ - if (device != NULL && - strncmp (device, "any", strlen("any")) == 0 - && yflag_dlt == -1) - yflag_dlt = DLT_LINUX_SLL2; -#endif - switch (ndo->ndo_tflag) { case 0: /* Default */ @@ -2008,6 +2027,8 @@ main(int argc, char **argv) /* Run with '-Z root' to restore old behaviour */ if (!username) username = WITH_USER; + else if (strcmp(username, "root") == 0) + username = NULL; } #endif @@ -2211,6 +2232,24 @@ main(int argc, char **argv) pcap_datalink_val_to_name(yflag_dlt)); (void)fflush(stderr); } +#if defined(DLT_LINUX_SLL2) && defined(HAVE_PCAP_SET_DATALINK) + else { + /* + * Attempt to set default linktype to + * DLT_LINUX_SLL2 when capturing on the + * "any" device. + * + * If the attempt fails, just quietly drive + * on; this may be a non-Linux "any" device + * that doesn't support DLT_LINUX_SLL2. + */ + if (strcmp(device, "any") == 0) { +DIAG_OFF_WARN_UNUSED_RESULT + (void) pcap_set_datalink(pd, DLT_LINUX_SLL2); +DIAG_ON_WARN_UNUSED_RESULT + } + } +#endif i = pcap_snapshot(pd); if (ndo->ndo_snaplen < i) { if (ndo->ndo_snaplen != 0) @@ -2290,33 +2329,33 @@ main(int argc, char **argv) /* Initialize capng */ capng_clear(CAPNG_SELECT_BOTH); if (username) { -DIAG_OFF_CLANG(assign-enum) +DIAG_OFF_ASSIGN_ENUM capng_updatev( CAPNG_ADD, CAPNG_PERMITTED | CAPNG_EFFECTIVE, CAP_SETUID, CAP_SETGID, -1); -DIAG_ON_CLANG(assign-enum) +DIAG_ON_ASSIGN_ENUM } if (chroot_dir) { -DIAG_OFF_CLANG(assign-enum) +DIAG_OFF_ASSIGN_ENUM capng_update( CAPNG_ADD, CAPNG_PERMITTED | CAPNG_EFFECTIVE, CAP_SYS_CHROOT ); -DIAG_ON_CLANG(assign-enum) +DIAG_ON_ASSIGN_ENUM } if (WFileName) { -DIAG_OFF_CLANG(assign-enum) +DIAG_OFF_ASSIGN_ENUM capng_update( CAPNG_ADD, CAPNG_PERMITTED | CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE ); -DIAG_ON_CLANG(assign-enum) +DIAG_ON_ASSIGN_ENUM } capng_apply(CAPNG_SELECT_BOTH); #endif /* HAVE_LIBCAP_NG */ @@ -2382,17 +2421,44 @@ DIAG_ON_CLANG(assign-enum) #endif if (Cflag != 0 || Gflag != 0) { #ifdef HAVE_CAPSICUM - dumpinfo.WFileName = strdup(basename(WFileName)); + /* + * basename() and dirname() may modify their input buffer + * and they do since FreeBSD 12.0, but they didn't before. + * Hence use the return value only, but always assume the + * input buffer has been modified and would need to be + * reset before the next use. + */ + char *WFileName_copy; + + if ((WFileName_copy = strdup(WFileName)) == NULL) { + error("Unable to allocate memory for file %s", + WFileName); + } + DIAG_OFF_C11_EXTENSIONS + dumpinfo.WFileName = strdup(basename(WFileName_copy)); + DIAG_ON_C11_EXTENSIONS if (dumpinfo.WFileName == NULL) { error("Unable to allocate memory for file %s", WFileName); } - dumpinfo.dirfd = open(dirname(WFileName), + free(WFileName_copy); + + if ((WFileName_copy = strdup(WFileName)) == NULL) { + error("Unable to allocate memory for file %s", + WFileName); + } + DIAG_OFF_C11_EXTENSIONS + char *WFileName_dirname = dirname(WFileName_copy); + DIAG_ON_C11_EXTENSIONS + dumpinfo.dirfd = open(WFileName_dirname, O_DIRECTORY | O_RDONLY); if (dumpinfo.dirfd < 0) { error("unable to open directory %s", - dirname(WFileName)); + WFileName_dirname); } + free(WFileName_dirname); + free(WFileName_copy); + cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL, CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE); if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 && @@ -2516,6 +2582,9 @@ DIAG_ON_CLANG(assign-enum) #else cansandbox = (cansandbox && ndo->ndo_nflag); #endif /* HAVE_CASPER */ + cansandbox = (cansandbox && (pcap_fileno(pd) != -1 || + RFileName != NULL)); + if (cansandbox && cap_enter() < 0 && errno != ENOSYS) error("unable to enter the capability mode"); #endif /* HAVE_CAPSICUM */ @@ -2607,6 +2676,8 @@ DIAG_ON_CLANG(assign-enum) */ dlt = new_dlt; ndo->ndo_if_printer = get_if_printer(dlt); + /* Free the old filter */ + pcap_freecode(&fcode); if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0) error("%s", pcap_geterr(pd)); } @@ -2641,7 +2712,7 @@ DIAG_ON_CLANG(assign-enum) free(cmdbuf); pcap_freecode(&fcode); - exit_tcpdump(status == -1 ? 1 : 0); + exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS); } /* @@ -2657,7 +2728,14 @@ static void memset(&new, 0, sizeof(new)); new.sa_handler = func; - if (sig == SIGCHLD) + if ((sig == SIGCHLD) +# ifdef SIGNAL_REQ_INFO + || (sig == SIGNAL_REQ_INFO) +# endif +# ifdef SIGNAL_FLUSH_PCAP + || (sig == SIGNAL_FLUSH_PCAP) +# endif + ) new.sa_flags = SA_RESTART; if (sigaction(sig, &new, &old) < 0) return (SIG_ERR); @@ -2722,7 +2800,7 @@ cleanup(int signo _U_) static void child_cleanup(int signo _U_) { - wait(NULL); + while (waitpid(-1, NULL, WNOHANG) >= 0); } #endif /* HAVE_FORK && HAVE_VFORK */ @@ -3127,7 +3205,7 @@ static void verbose_stats_dump(int sig _U_) } #endif /* _WIN32 */ -USES_APPLE_DEPRECATED_API +DIAG_OFF_DEPRECATION static void print_version(FILE *f) { @@ -3165,7 +3243,7 @@ print_version(FILE *f) # endif #endif /* __SANITIZE_ADDRESS__ or __has_feature */ } -USES_APPLE_RST +DIAG_ON_DEPRECATION static void print_usage(FILE *f)