X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/b30f3843b93c11e897e6d8888a91abf709a716ae..03c037bbd75588beba3ee09f26d17783d21e30bc:/tcpdump.c diff --git a/tcpdump.c b/tcpdump.c index 939df0b4..0b654158 100644 --- a/tcpdump.c +++ b/tcpdump.c @@ -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 @@ -151,6 +153,7 @@ The Regents of the University of California. All rights reserved.\n"; #include #endif /* __FreeBSD__ */ +#include "netdissect-stdinc.h" #include "netdissect.h" #include "interface.h" #include "addrtoname.h" @@ -160,6 +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 @@ -237,10 +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); @@ -248,8 +249,8 @@ static NORETURN void exit_tcpdump(int); static void (*setsignal (int sig, void (*func)(int)))(int); static void cleanup(int); static void child_cleanup(int); -static void print_version(void); -static void print_usage(void); +static void print_version(FILE *); +static void print_usage(FILE *); #ifdef HAVE_PCAP_SET_TSTAMP_TYPE static NORETURN void show_tstamp_types_and_exit(pcap_t *, const char *device); #endif @@ -806,7 +807,7 @@ droproot(const char *username, const char *chroot_dir) 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) +DIAG_OFF_ASSIGN_ENUM capng_updatev( CAPNG_DROP, CAPNG_EFFECTIVE | CAPNG_PERMITTED, @@ -814,7 +815,7 @@ 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 */ @@ -841,7 +842,9 @@ MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars) { char *filename = malloc(PATH_MAX + 1); if (filename == NULL) - error("Makefilename: malloc"); + 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) { @@ -849,13 +852,29 @@ MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars) /* Convert Gflag_time to a usable format */ if ((local_tm = localtime(&Gflag_time)) == NULL) { - error("MakeTimedFilename: localtime"); + error("%s: localtime", __func__); } /* 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); } @@ -1035,7 +1054,7 @@ copy_argv(char **argv) buf = (char *)malloc(len); if (buf == NULL) - error("copy_argv: malloc"); + error("%s: malloc", __func__); p = argv; dst = buf; @@ -1065,15 +1084,22 @@ read_infile(char *fname) int i, fd; ssize_t cc; char *cp; - struct stat buf; + our_statb buf; fd = open(fname, O_RDONLY|O_BINARY); if (fd < 0) error("can't open %s: %s", fname, pcap_strerror(errno)); - if (fstat(fd, &buf) < 0) + if (our_fstat(fd, &buf) < 0) error("can't stat %s: %s", fname, pcap_strerror(errno)); + /* + * Reject files whose size doesn't fit into an int; a filter + * *that* large will probably be too big. + */ + if (buf.st_size > INT_MAX) + error("%s is too large", fname); + cp = malloc((u_int)buf.st_size + 1); if (cp == NULL) error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1, @@ -1082,7 +1108,8 @@ read_infile(char *fname) if (cc < 0) error("read %s: %s", fname, pcap_strerror(errno)); if (cc != buf.st_size) - error("short read %s (%zd != %d)", fname, cc, (int)buf.st_size); + error("short read %s (%d != %d)", fname, (int) cc, + (int)buf.st_size); close(fd); /* replace "# comment" with spaces */ @@ -1632,13 +1659,13 @@ main(int argc, char **argv) /* 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)); + error("%s: can't get current time: %s", + __func__, pcap_strerror(errno)); } break; case 'h': - print_usage(); + print_usage(stdout); exit_tcpdump(S_SUCCESS); break; @@ -1880,7 +1907,7 @@ main(int argc, char **argv) break; case OPTION_VERSION: - print_version(); + print_version(stdout); exit_tcpdump(S_SUCCESS); break; @@ -1928,7 +1955,7 @@ main(int argc, char **argv) break; default: - print_usage(); + print_usage(stderr); exit_tcpdump(S_ERR_HOST_PROGRAM); /* NOTREACHED */ } @@ -2281,33 +2308,33 @@ 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 */ @@ -2373,17 +2400,44 @@ 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 && @@ -2438,11 +2492,14 @@ DIAG_ON_CLANG(assign-enum) (void)setsignal(SIGNAL_FLUSH_PCAP, flushpcap); #endif - if (ndo->ndo_vflag > 0 && WFileName && !print) { + if (ndo->ndo_vflag > 0 && WFileName && RFileName == NULL && !print) { /* * When capturing to a file, if "--print" wasn't specified, *"-v" means tcpdump should, once per second, * "v"erbosely report the number of packets captured. + * Except when reading from a file, because -r, -w and -v + * together used to make a corner case, in which pcap_loop() + * errored due to EINTR (see GH #155 for details). */ #ifdef _WIN32 /* @@ -2624,12 +2681,12 @@ DIAG_ON_CLANG(assign-enum) while (ret != NULL); if (count_mode && RFileName != NULL) - fprintf(stderr, "%u packet%s\n", packets_captured, + fprintf(stdout, "%u packet%s\n", packets_captured, PLURAL_SUFFIX(packets_captured)); free(cmdbuf); pcap_freecode(&fcode); - exit_tcpdump(status == -1 ? 1 : 0); + exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS); } /* @@ -2645,7 +2702,14 @@ 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); @@ -2837,8 +2901,8 @@ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *s /* 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)); + error("%s: can't get current_time: %s", + __func__, pcap_strerror(errno)); } @@ -2979,7 +3043,7 @@ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *s free(dump_info->CurrentFileName); dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1); if (dump_info->CurrentFileName == NULL) - error("dump_packet_and_trunc: malloc"); + error("%s: malloc", __func__); MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars); #ifdef HAVE_LIBCAP_NG capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE); @@ -3115,9 +3179,9 @@ static void verbose_stats_dump(int sig _U_) } #endif /* _WIN32 */ -USES_APPLE_DEPRECATED_API +DIAG_OFF_DEPRECATION static void -print_version(void) +print_version(FILE *f) { #ifndef HAVE_PCAP_LIB_VERSION #ifdef HAVE_PCAP_VERSION @@ -3128,61 +3192,61 @@ print_version(void) #endif /* HAVE_PCAP_LIB_VERSION */ const char *smi_version_string; - (void)fprintf(stderr, "%s version " PACKAGE_VERSION "\n", program_name); + (void)fprintf(f, "%s version " PACKAGE_VERSION "\n", program_name); #ifdef HAVE_PCAP_LIB_VERSION - (void)fprintf(stderr, "%s\n", pcap_lib_version()); + (void)fprintf(f, "%s\n", pcap_lib_version()); #else /* HAVE_PCAP_LIB_VERSION */ - (void)fprintf(stderr, "libpcap version %s\n", pcap_version); + (void)fprintf(f, "libpcap version %s\n", pcap_version); #endif /* HAVE_PCAP_LIB_VERSION */ #if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION) - (void)fprintf (stderr, "%s\n", SSLeay_version(SSLEAY_VERSION)); + (void)fprintf (f, "%s\n", SSLeay_version(SSLEAY_VERSION)); #endif smi_version_string = nd_smi_version_string(); if (smi_version_string != NULL) - (void)fprintf (stderr, "SMI-library: %s\n", smi_version_string); + (void)fprintf (f, "SMI-library: %s\n", smi_version_string); #if defined(__SANITIZE_ADDRESS__) - (void)fprintf (stderr, "Compiled with AddressSanitizer/GCC.\n"); + (void)fprintf (f, "Compiled with AddressSanitizer/GCC.\n"); #elif defined(__has_feature) # if __has_feature(address_sanitizer) - (void)fprintf (stderr, "Compiled with AddressSanitizer/Clang.\n"); + (void)fprintf (f, "Compiled with AddressSanitizer/Clang.\n"); # elif __has_feature(memory_sanitizer) - (void)fprintf (stderr, "Compiled with MemorySanitizer/Clang.\n"); + (void)fprintf (f, "Compiled with MemorySanitizer/Clang.\n"); # endif #endif /* __SANITIZE_ADDRESS__ or __has_feature */ } -USES_APPLE_RST +DIAG_ON_DEPRECATION static void -print_usage(void) +print_usage(FILE *f) { - print_version(); - (void)fprintf(stderr, + print_version(f); + (void)fprintf(f, "Usage: %s [-Abd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ] [--count]\n", program_name); - (void)fprintf(stderr, + (void)fprintf(f, "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n"); - (void)fprintf(stderr, + (void)fprintf(f, "\t\t[ -i interface ]" IMMEDIATE_MODE_USAGE j_FLAG_USAGE "\n"); #ifdef HAVE_PCAP_FINDALLDEVS_EX - (void)fprintf(stderr, + (void)fprintf(f, "\t\t" LIST_REMOTE_INTERFACES_USAGE "\n"); #endif #ifdef USE_LIBSMI - (void)fprintf(stderr, + (void)fprintf(f, "\t\t" m_FLAG_USAGE "\n"); #endif - (void)fprintf(stderr, + (void)fprintf(f, "\t\t[ -M secret ] [ --number ] [ --print ]" Q_FLAG_USAGE "\n"); - (void)fprintf(stderr, + (void)fprintf(f, "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ --version ]\n"); - (void)fprintf(stderr, + (void)fprintf(f, "\t\t[ -V file ] [ -w file ] [ -W filecount ] [ -y datalinktype ]\n"); #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION - (void)fprintf(stderr, + (void)fprintf(f, "\t\t[ --time-stamp-precision precision ] [ --micro ] [ --nano ]\n"); #endif - (void)fprintf(stderr, + (void)fprintf(f, "\t\t[ -z postrotate-command ] [ -Z user ] [ expression ]\n"); }