]> The Tcpdump Group git mirrors - tcpdump/blobdiff - tcpdump.c
Improve the handling of size suffixes for -C.
[tcpdump] / tcpdump.c
index a44baa29ccadd709ff3e4960779e133f9a14dfbc..95162ecc18165f9a4518354684698e783b94ebfd 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -124,6 +124,16 @@ The Regents of the University of California.  All rights reserved.\n";
 #include <grp.h>
 #endif /* _WIN32 */
 
+/*
+ * Pathname separator.
+ * Use this in pathnames, but do *not* use it in URLs.
+ */
+#ifdef _WIN32
+#define PATH_SEPARATOR '\\'
+#else
+#define PATH_SEPARATOR '/'
+#endif
+
 /* capabilities convenience library */
 /* If a code depends on HAVE_LIBCAP_NG, it depends also on HAVE_CAP_NG_H.
  * If HAVE_CAP_NG_H is not defined, undefine HAVE_LIBCAP_NG.
@@ -141,6 +151,7 @@ The Regents of the University of California.  All rights reserved.\n";
 #include <sys/sysctl.h>
 #endif /* __FreeBSD__ */
 
+#include "netdissect-stdinc.h"
 #include "netdissect.h"
 #include "interface.h"
 #include "addrtoname.h"
@@ -150,6 +161,8 @@ The Regents of the University of California.  All rights reserved.\n";
 
 #include "print.h"
 
+#include "fptype.h"
+
 #ifndef PATH_MAX
 #define PATH_MAX 1024
 #endif
@@ -203,6 +216,7 @@ static int Iflag;                   /* rfmon (monitor) mode */
 static int Jflag;                      /* list available time stamp types */
 static int jflag = -1;                 /* packet time stamp source */
 #endif
+static int lflag;                      /* line-buffered output */
 static int pflag;                      /* don't go promiscuous */
 #ifdef HAVE_PCAP_SETDIRECTION
 static int Qflag = -1;                 /* restrict captured packet by send/receive direction */
@@ -213,9 +227,11 @@ static int Uflag;                  /* "unbuffered" output of dump files */
 static int Wflag;                      /* recycle output files after this number of files */
 static int WflagChars;
 static char *zflag = NULL;             /* compress each savefile using a specified command (like gzip or bzip2) */
+static int timeout = 1000;             /* default timeout = 1000 ms = 1 s */
 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
 static int immediate_mode;
 #endif
+static int count_mode;
 
 static int infodelay;
 static int infoprint;
@@ -227,29 +243,15 @@ 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);
-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);
-#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
-static NORETURN void show_tstamp_types_and_exit(pcap_t *, const char *device);
-#endif
-static NORETURN void show_dlts_and_exit(pcap_t *, const char *device);
-#ifdef HAVE_PCAP_FINDALLDEVS
-static NORETURN void show_devices_and_exit(void);
-#endif
-#ifdef HAVE_PCAP_FINDALLDEVS_EX
-static NORETURN void show_remote_devices_and_exit(void);
-#endif
+static void print_version(FILE *);
+static void print_usage(FILE *);
 
 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 *);
-static void droproot(const char *, const char *);
 
 #ifdef SIGNAL_REQ_INFO
 static void requestinfo(int);
@@ -356,9 +358,16 @@ extern
 void pcap_set_optimizer_debug(int);
 #endif
 
+static void NORETURN
+exit_tcpdump(const int status)
+{
+       nd_cleanup();
+       exit(status);
+}
+
 /* VARARGS */
-static void
-error(const char *fmt, ...)
+static void NORETURN PRINTFLIKE(1, 2)
+error(FORMAT_STRING(const char *fmt), ...)
 {
        va_list ap;
 
@@ -376,8 +385,8 @@ error(const char *fmt, ...)
 }
 
 /* VARARGS */
-static void
-warning(const char *fmt, ...)
+static void PRINTFLIKE(1, 2)
+warning(FORMAT_STRING(const char *fmt), ...)
 {
        va_list ap;
 
@@ -392,15 +401,8 @@ warning(const char *fmt, ...)
        }
 }
 
-static void
-exit_tcpdump(int status)
-{
-       nd_cleanup();
-       exit(status);
-}
-
 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
-static void
+static void NORETURN
 show_tstamp_types_and_exit(pcap_t *pc, const char *device)
 {
        int n_tstamp_types;
@@ -417,15 +419,15 @@ 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);
@@ -433,7 +435,7 @@ show_tstamp_types_and_exit(pcap_t *pc, const char *device)
 }
 #endif
 
-static void
+static void NORETURN
 show_dlts_and_exit(pcap_t *pc, const char *device)
 {
        int n_dlts, i;
@@ -454,28 +456,30 @@ 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]);
                }
        }
@@ -486,7 +490,7 @@ show_dlts_and_exit(pcap_t *pc, const char *device)
 }
 
 #ifdef HAVE_PCAP_FINDALLDEVS
-static void
+static void NORETURN
 show_devices_and_exit(void)
 {
        pcap_if_t *dev, *devlist;
@@ -551,7 +555,7 @@ show_devices_and_exit(void)
 #endif /* HAVE_PCAP_FINDALLDEVS */
 
 #ifdef HAVE_PCAP_FINDALLDEVS_EX
-static void
+static void NORETURN
 show_remote_devices_and_exit(void)
 {
        pcap_if_t *dev, *devlist;
@@ -685,6 +689,8 @@ show_remote_devices_and_exit(void)
 #define OPTION_LIST_REMOTE_INTERFACES  132
 #define OPTION_TSTAMP_MICRO            133
 #define OPTION_TSTAMP_NANO             134
+#define OPTION_FP_TYPE                 135
+#define OPTION_COUNT                   136
 
 static const struct option longopts[] = {
 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
@@ -728,6 +734,8 @@ static const struct option longopts[] = {
        { "debug-filter-parser", no_argument, NULL, 'Y' },
 #endif
        { "relinquish-privileges", required_argument, NULL, 'Z' },
+       { "count", no_argument, NULL, OPTION_COUNT },
+       { "fp-type", no_argument, NULL, OPTION_FP_TYPE },
        { "number", no_argument, NULL, '#' },
        { "print", no_argument, NULL, OPTION_PRINT },
        { "version", no_argument, NULL, OPTION_VERSION },
@@ -822,7 +830,7 @@ 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__);
 
         /* Process with strftime if Gflag is set. */
         if (Gflag != 0) {
@@ -830,7 +838,7 @@ 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
@@ -932,7 +940,7 @@ tstamp_precision_to_string(int precision)
  * necessary to make the standard I/O library work with an fdopen()ed
  * FILE * from that descriptor.
  *
- * A long time ago, in a galaxy far far away, AT&T decided that, instead
+ * A long time ago in a galaxy far, far away, AT&T decided that, instead
  * of providing separate APIs for getting and setting the FD_ flags on a
  * descriptor, getting and setting the O_ flags on a descriptor, and
  * locking files, they'd throw them all into a kitchen-sink fcntl() call
@@ -1016,7 +1024,7 @@ copy_argv(char **argv)
 
        buf = (char *)malloc(len);
        if (buf == NULL)
-               error("copy_argv: malloc");
+               error("%s: malloc", __func__);
 
        p = argv;
        dst = buf;
@@ -1046,15 +1054,22 @@ 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,
@@ -1063,7 +1078,8 @@ 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 */
@@ -1229,7 +1245,7 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                 */
                *ebuf = '\0';
                pc = pcap_open(device, ndo->ndo_snaplen,
-                   pflag ? 0 : PCAP_OPENFLAG_PROMISCUOUS, 1000, NULL,
+                   pflag ? 0 : PCAP_OPENFLAG_PROMISCUOUS, timeout, NULL,
                    ebuf);
                if (pc == NULL) {
                        /*
@@ -1311,7 +1327,7 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                        error("%s: Can't set monitor mode: %s",
                            device, pcap_statustostr(status));
        }
-       status = pcap_set_timeout(pc, 1000);
+       status = pcap_set_timeout(pc, timeout);
        if (status != 0)
                error("%s: pcap_set_timeout failed: %s",
                    device, pcap_statustostr(status));
@@ -1347,8 +1363,6 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                         */
                        snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
                            device, pcap_statustostr(status), cp);
-                       pcap_close(pc);
-                       return (NULL);
                } else if (status == PCAP_ERROR_PERM_DENIED && *cp != '\0')
                        error("%s: %s\n(%s)", device,
                            pcap_statustostr(status), cp);
@@ -1379,6 +1393,8 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                else
                        error("%s: %s", device,
                            pcap_statustostr(status));
+               pcap_close(pc);
+               return (NULL);
        } else if (status > 0) {
                /*
                 * pcap_activate() succeeded, but it's warning us
@@ -1411,7 +1427,7 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
         */
        if (ndo->ndo_snaplen == 0)
                ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
-       pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, 1000, ebuf);
+       pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, timeout, ebuf);
        if (pc == NULL) {
                /*
                 * If this failed with "No such device", that means
@@ -1468,6 +1484,7 @@ main(int argc, char **argv)
        int yflag_dlt = -1;
        const char *yflag_dlt_name = NULL;
        int print = 0;
+       long Cflagmult;
 
        netdissect_options Ndo;
        netdissect_options *ndo = &Ndo;
@@ -1489,7 +1506,7 @@ main(int argc, char **argv)
        VFile = NULL;
        WFileName = NULL;
        dlt = -1;
-       if ((cp = strrchr(argv[0], '/')) != NULL)
+       if ((cp = strrchr(argv[0], PATH_SEPARATOR)) != NULL)
                ndo->program_name = program_name = cp + 1;
        else
                ndo->program_name = program_name = argv[0];
@@ -1549,19 +1566,77 @@ main(int argc, char **argv)
 #else
                        Cflag = strtol(optarg, &endp, 10);
 #endif
-                       if (endp == optarg || *endp != '\0' || errno != 0
-                           || Cflag <= 0)
+                       if (endp == optarg || errno != 0 || Cflag <= 0)
                                error("invalid file size %s", optarg);
+
+                       if (*endp == '\0') {
+                               /*
+                                * There's nothing after the file size,
+                                * so the size is in units of 1 MB
+                                * (1,000,000 bytes).
+                                */
+                               Cflagmult = 1000000;
+                       } else {
+                               /*
+                                * There's something after the file
+                                * size.
+                                *
+                                * If it's a single letter, then:
+                                *
+                                *   if the letter is k or K, the size
+                                *   is in units of 1 KiB (1024 bytes);
+                                *
+                                *   if the letter is m or M, the size
+                                *   is in units of 1 MiB (1,048,576 bytes);
+                                *
+                                *   if the letter is g or G, the size
+                                *   is in units of 1 GiB (1,073,741,824 bytes).
+                                *
+                                * Otherwise, it's an error.
+                                */
+                               switch (*endp) {
+
+                               case 'k':
+                               case 'K':
+                                       Cflagmult = 1024;
+                                       break;
+
+                               case 'm':
+                               case 'M':
+                                       Cflagmult = 1024*1024;
+                                       break;
+
+                               case 'g':
+                               case 'G':
+                                       Cflagmult = 1024*1024*1024;
+                                       break;
+
+                               default:
+                                       error("invalid file size %s", optarg);
+                               }
+
+                               /*
+                                * OK, there was a letter that we treat
+                                * as a units indication; was there
+                                * anything after it?
+                                */
+                               endp++;
+                               if (*endp != '\0') {
+                                       /* Yes - error */
+                                       error("invalid file size %s", optarg);
+                               }
+                       }
+
                        /*
-                        * Will multiplying it by 1000000 overflow?
+                        * Will multiplying it by multiplier overflow?
                         */
 #ifdef HAVE_PCAP_DUMP_FTELL64
-                       if (Cflag > INT64_T_CONSTANT(0x7fffffffffffffff) / 1000000)
+                       if (Cflag > INT64_T_CONSTANT(0x7fffffffffffffff) / Cflagmult)
 #else
-                       if (Cflag > LONG_MAX / 1000000)
+                       if (Cflag > LONG_MAX / Cflagmult)
 #endif
                                error("file size %s is too large", optarg);
-                       Cflag *= 1000000;
+                       Cflag *= Cflagmult;
                        break;
 
                case 'd':
@@ -1613,13 +1688,13 @@ 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;
 
@@ -1668,6 +1743,7 @@ main(int argc, char **argv)
                        setvbuf(stdout, NULL, _IOLBF, 0);
 #endif
 #endif /* _WIN32 */
+                       lflag = 1;
                        break;
 
                case 'K':
@@ -1784,6 +1860,10 @@ main(int argc, char **argv)
                                ndo->ndo_packettype = PT_RESP;
                        else if (ascii_strcasecmp(optarg, "ptp") == 0)
                                ndo->ndo_packettype = PT_PTP;
+                       else if (ascii_strcasecmp(optarg, "someip") == 0)
+                               ndo->ndo_packettype = PT_SOMEIP;
+                       else if (ascii_strcasecmp(optarg, "domain") == 0)
+                               ndo->ndo_packettype = PT_DOMAIN;
                        else
                                error("unknown packet type `%s'", optarg);
                        break;
@@ -1856,7 +1936,7 @@ main(int argc, char **argv)
                        break;
 
                case OPTION_VERSION:
-                       print_version();
+                       print_version(stdout);
                        exit_tcpdump(S_SUCCESS);
                        break;
 
@@ -1888,8 +1968,23 @@ main(int argc, char **argv)
                        break;
 #endif
 
+               case OPTION_FP_TYPE:
+                       /*
+                        * Print out the type of floating-point arithmetic
+                        * we're doing; it's probably IEEE, unless somebody
+                        * tries to run this on a VAX, but the precision
+                        * may differ (e.g., it might be 32-bit, 64-bit,
+                        * or 80-bit).
+                        */
+                       float_type_check(0x4e93312d);
+                       return 0;
+
+               case OPTION_COUNT:
+                       count_mode = 1;
+                       break;
+
                default:
-                       print_usage();
+                       print_usage(stderr);
                        exit_tcpdump(S_ERR_HOST_PROGRAM);
                        /* NOTREACHED */
                }
@@ -1903,6 +1998,14 @@ 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 */
@@ -1924,19 +2027,18 @@ main(int argc, char **argv)
        if (VFileName != NULL && RFileName != NULL)
                error("-V and -r are mutually exclusive.");
 
-#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
        /*
-        * If we're printing dissected packets to the standard output
-        * and the standard output is a terminal, use immediate mode,
-        * as the user's probably expecting to see packets pop up
-        * immediately.
+        * If we're printing dissected packets to the standard output,
+        * and either the standard output is a terminal or we're doing
+        * "line" buffering, set the capture timeout to .1 second rather
+        * than 1 second, as the user's probably expecting to see packets
+        * pop up immediately shortly after they arrive.
         *
-        * XXX - set the timeout to a lower value, instead?  If so,
-        * what value would be appropriate?
+        * XXX - would there be some value appropriate for all cases,
+        * based on, say, the buffer size and packet input rate?
         */
-       if ((WFileName == NULL || print) && isatty(1))
-               immediate_mode = 1;
-#endif
+       if ((WFileName == NULL || print) && (isatty(1) || lflag))
+               timeout = 100;
 
 #ifdef WITH_CHROOT
        /* if run as root, prepare for chrooting */
@@ -2152,7 +2254,8 @@ main(int argc, char **argv)
                        }
 #endif
                        (void)fprintf(stderr, "%s: data link type %s\n",
-                                     program_name, yflag_dlt_name);
+                                     program_name,
+                                     pcap_datalink_val_to_name(yflag_dlt));
                        (void)fflush(stderr);
                }
                i = pcap_snapshot(pd);
@@ -2363,7 +2466,7 @@ DIAG_ON_CLANG(assign-enum)
                }
                if (print) {
                        dlt = pcap_datalink(pd);
-                       ndo->ndo_if_printer = get_if_printer(ndo, dlt);
+                       ndo->ndo_if_printer = get_if_printer(dlt);
                        dumpinfo.ndo = ndo;
                } else
                        dumpinfo.ndo = NULL;
@@ -2374,7 +2477,7 @@ DIAG_ON_CLANG(assign-enum)
 #endif
        } else {
                dlt = pcap_datalink(pd);
-               ndo->ndo_if_printer = get_if_printer(ndo, dlt);
+               ndo->ndo_if_printer = get_if_printer(dlt);
                callback = print_packet;
                pcap_userdata = (u_char *)ndo;
        }
@@ -2391,11 +2494,14 @@ 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
                /*
@@ -2433,7 +2539,7 @@ DIAG_ON_CLANG(assign-enum)
                 */
                if (!ndo->ndo_vflag && !WFileName) {
                        (void)fprintf(stderr,
-                           "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
+                           "%s: verbose output suppressed, use -v[v]... for full protocol decode\n",
                            program_name);
                } else
                        (void)fprintf(stderr, "%s: ", program_name);
@@ -2547,7 +2653,7 @@ DIAG_ON_CLANG(assign-enum)
                                         * the new DLT.
                                         */
                                        dlt = new_dlt;
-                                       ndo->ndo_if_printer = get_if_printer(ndo, dlt);
+                                       ndo->ndo_if_printer = get_if_printer(dlt);
                                        if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
                                                error("%s", pcap_geterr(pd));
                                }
@@ -2576,6 +2682,10 @@ DIAG_ON_CLANG(assign-enum)
        }
        while (ret != NULL);
 
+       if (count_mode && RFileName != NULL)
+               fprintf(stdout, "%u packet%s\n", packets_captured,
+                       PLURAL_SUFFIX(packets_captured));
+
        free(cmdbuf);
        pcap_freecode(&fcode);
        exit_tcpdump(status == -1 ? 1 : 0);
@@ -2786,8 +2896,8 @@ 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));
                }
 
 
@@ -2928,7 +3038,7 @@ 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);
@@ -3008,7 +3118,8 @@ print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 
        ++infodelay;
 
-       pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
+       if (!count_mode)
+               pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
 
        --infodelay;
        if (infoprint)
@@ -3065,7 +3176,7 @@ static void verbose_stats_dump(int sig _U_)
 
 USES_APPLE_DEPRECATED_API
 static void
-print_version(void)
+print_version(FILE *f)
 {
 #ifndef HAVE_PCAP_LIB_VERSION
   #ifdef HAVE_PCAP_VERSION
@@ -3076,59 +3187,61 @@ 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 (f, "Compiled with MemorySanitizer/Clang.\n");
 #  endif
 #endif /* __SANITIZE_ADDRESS__ or __has_feature */
 }
 USES_APPLE_RST
 
 static void
-print_usage(void)
+print_usage(FILE *f)
 {
-       print_version();
-       (void)fprintf(stderr,
-"Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ]\n", program_name);
-       (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(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");
 }