]> The Tcpdump Group git mirrors - tcpdump/blobdiff - tcpdump.c
CMake: Fix the comment about versions. [skip ci]
[tcpdump] / tcpdump.c
index c256098cef417418b0c7cac9afcd855ffaeb986c..9bab8d87850044e0bb1051346bd77642c556901b 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
  */
 
-#ifdef HAVE_CONFIG_H
 #include <config.h>
-#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().
@@ -63,9 +61,7 @@ The Regents of the University of California.  All rights reserved.\n";
 
 #include <sys/stat.h>
 
-#ifdef HAVE_FCNTL_H
 #include <fcntl.h>
-#endif
 
 #ifdef HAVE_LIBCRYPTO
 #include <openssl/crypto.h>
@@ -74,14 +70,16 @@ The Regents of the University of California.  All rights reserved.\n";
 #ifdef HAVE_GETOPT_LONG
 #include <getopt.h>
 #else
-#include "getopt_long.h"
+#include "missing/getopt_long.h"
 #endif
 /* Capsicum-specific code requires macros from <net/bpf.h>, which will fail
  * to compile if <pcap.h> 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 <pcap/pcap.h> declares bpf_dump() instead of <net/bpf.h>. Thus
+ * interface.h takes care of it later to avoid a compiler warning.
  */
 #ifdef HAVE_CAPSICUM
-#include <sys/capability.h>
+#include <sys/capsicum.h>
 #include <sys/ioccom.h>
 #include <net/bpf.h>
 #include <libgen.h>
@@ -92,6 +90,19 @@ The Regents of the University of California.  All rights reserved.\n";
 #endif /* HAVE_CASPER */
 #endif /* HAVE_CAPSICUM */
 #ifdef HAVE_PCAP_OPEN
+/*
+ * We found pcap_open() in the capture library, so we'll be using
+ * the remote capture APIs; define PCAP_REMOTE before we include pcap.h,
+ * so we get those APIs declared, and the types and #defines that they
+ * use defined.
+ *
+ * WinPcap's headers require that PCAP_REMOTE be defined in order to get
+ * remote-capture APIs declared and types and #defines that they use
+ * defined.
+ *
+ * (Versions of libpcap with those APIs, and thus Npcap, which is based on
+ * those versions of libpcap, don't require it.)
+ */
 #define HAVE_REMOTE
 #endif
 #include <pcap.h>
@@ -111,6 +122,16 @@ 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.
@@ -128,16 +149,20 @@ 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"
 #include "machdep.h"
-#include "gmt2local.h"
 #include "pcap-missing.h"
 #include "ascii_strcasecmp.h"
 
 #include "print.h"
 
+#include "diag-control.h"
+
+#include "fptype.h"
+
 #ifndef PATH_MAX
 #define PATH_MAX 1024
 #endif
@@ -152,7 +177,9 @@ The Regents of the University of California.  All rights reserved.\n";
 #define SIGNAL_FLUSH_PCAP SIGUSR2
 #endif
 
+#if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
 static int Bflag;                      /* buffer size */
+#endif
 #ifdef HAVE_PCAP_DUMP_FTELL64
 static int64_t Cflag;                  /* rotate dump files after this many bytes */
 #else
@@ -178,6 +205,7 @@ static char *remote_interfaces_source;      /* list available devices from this sourc
  * dflag but, instead, *if* built with optimizer debugging code,
  * *export* a routine to set that flag.
  */
+extern int dflag;
 int dflag;                             /* print filter code */
 static int Gflag;                      /* rotate dump files after this many seconds */
 static int Gflag_count;                        /* number of files created with Gflag rotation */
@@ -186,29 +214,30 @@ static int Lflag;                 /* list available data link types and exit */
 static int Iflag;                      /* rfmon (monitor) mode */
 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 static int Jflag;                      /* list available time stamp types */
-#endif
 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 */
 #endif
+#ifdef HAVE_PCAP_DUMP_FLUSH
 static int Uflag;                      /* "unbuffered" output of dump files */
+#endif
 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;
 
 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);
@@ -216,9 +245,11 @@ 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
 static NORETURN void show_dlts_and_exit(pcap_t *, const char *device);
 #ifdef HAVE_PCAP_FINDALLDEVS
 static NORETURN void show_devices_and_exit(void);
@@ -398,15 +429,15 @@ 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);
@@ -435,28 +466,30 @@ 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]);
                }
        }
@@ -619,6 +652,10 @@ show_remote_devices_and_exit(void)
 #define J_FLAG
 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 
+#ifdef USE_LIBSMI
+#define m_FLAG_USAGE "[ -m module ] ..."
+#endif
+
 #ifdef HAVE_PCAP_SETDIRECTION
 #define Q_FLAG "Q:"
 #define Q_FLAG_USAGE " [ -Q in|out|inout ]"
@@ -660,6 +697,11 @@ show_remote_devices_and_exit(void)
 #define OPTION_IMMEDIATE_MODE          130
 #define OPTION_PRINT                   131
 #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
+#define OPTION_TIME_T_SIZE             139
 
 static const struct option longopts[] = {
 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
@@ -679,6 +721,8 @@ static const struct option longopts[] = {
        { "list-time-stamp-types", no_argument, NULL, 'J' },
 #endif
 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
+       { "micro", no_argument, NULL, OPTION_TSTAMP_MICRO},
+       { "nano", no_argument, NULL, OPTION_TSTAMP_NANO},
        { "time-stamp-precision", required_argument, NULL, OPTION_TSTAMP_PRECISION},
 #endif
        { "dont-verify-checksums", no_argument, NULL, 'K' },
@@ -701,14 +745,17 @@ 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 },
+       { "time-t-size", no_argument, NULL, OPTION_TIME_T_SIZE },
        { "version", no_argument, NULL, OPTION_VERSION },
        { NULL, 0, NULL, 0 }
 };
 
 #ifdef HAVE_PCAP_FINDALLDEVS_EX
-#define LIST_REMOTE_INTERFACES_USAGE "[ --list-remote-interfaces remote-source  ]"
+#define LIST_REMOTE_INTERFACES_USAGE "[ --list-remote-interfaces remote-source ]"
 #else
 #define LIST_REMOTE_INTERFACES_USAGE
 #endif
@@ -719,12 +766,6 @@ static const struct option longopts[] = {
 #define IMMEDIATE_MODE_USAGE ""
 #endif
 
-#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
-#define TIME_STAMP_PRECISION_USAGE " [ --time-stamp-precision precision ]"
-#else
-#define TIME_STAMP_PRECISION_USAGE
-#endif
-
 #ifndef _WIN32
 /* Drop root privileges and chroot if necessary */
 static void
@@ -745,11 +786,10 @@ droproot(const char *username, const char *chroot_dir)
 #ifdef HAVE_LIBCAP_NG
                {
                        int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
-                       if (ret < 0) {
-                               fprintf(stderr, "error : ret %d\n", ret);
-                       } else {
+                       if (ret < 0)
+                               error("capng_change_id(): return %d\n", ret);
+                       else
                                fprintf(stderr, "dropped privs to %s\n", username);
-                       }
                }
 #else
                if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
@@ -766,8 +806,8 @@ 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,
@@ -775,7 +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 */
 
@@ -802,7 +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) {
@@ -810,13 +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);
         }
@@ -824,7 +882,7 @@ MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
        if (cnt == 0 && max_chars == 0)
                strncpy(buffer, filename, PATH_MAX + 1);
        else
-               if (nd_snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
+               if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
                   /* Report an error if the filename is too large */
                   error("too many output files or filename is too long (> %d)", PATH_MAX);
         free(filename);
@@ -834,13 +892,15 @@ static char *
 get_next_file(FILE *VFile, char *ptr)
 {
        char *ret;
+       size_t len;
 
        ret = fgets(ptr, PATH_MAX, VFile);
        if (!ret)
                return NULL;
 
-       if (ptr[strlen(ptr) - 1] == '\n')
-               ptr[strlen(ptr) - 1] = '\0';
+       len = strlen (ptr);
+       if (len > 0 && ptr[len - 1] == '\n')
+               ptr[len - 1] = '\0';
 
        return ret;
 }
@@ -910,14 +970,14 @@ 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
  * 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
@@ -981,7 +1041,7 @@ static char *
 copy_argv(char **argv)
 {
        char **p;
-       u_int len = 0;
+       size_t len = 0;
        char *buf;
        char *src, *dst;
 
@@ -994,7 +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;
@@ -1021,17 +1081,25 @@ copy_argv(char **argv)
 static char *
 read_infile(char *fname)
 {
-       int i, fd, cc;
+       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,
@@ -1040,7 +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 (%d != %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 */
@@ -1095,7 +1164,7 @@ parse_interface_number(const char *device)
                        /*
                         * No, it's not an ordinal.
                         */
-                       error("Invalid adapter index");
+                       error("Invalid adapter index %s", device);
                }
                return (devnum);
        } else {
@@ -1152,6 +1221,9 @@ _U_
                 */
                endp++; /* Include the trailing / in the URL; pcap_findalldevs_ex() requires it */
                host_url = malloc(endp - url + 1);
+               if (host_url == NULL && (endp - url + 1) > 0)
+                       error("Invalid allocation for host");
+
                memcpy(host_url, url, endp - url);
                host_url[endp - url] = '\0';
                status = pcap_findalldevs_ex(host_url, NULL, &devlist, ebuf);
@@ -1167,8 +1239,11 @@ _U_
        for (i = 0, dev = devlist; i < devnum-1 && dev != NULL;
            i++, dev = dev->next)
                ;
-       if (dev == NULL)
-               error("Invalid adapter index");
+       if (dev == NULL) {
+               pcap_freealldevs(devlist);
+               error("Invalid adapter index %ld: only %ld interfaces found",
+                   devnum, i);
+       }
        device = strdup(dev->name);
        pcap_freealldevs(devlist);
        return (device);
@@ -1177,9 +1252,10 @@ _U_
 
 #ifdef HAVE_PCAP_OPEN
 /*
- * Prefix for rpcap URLs.
+ * Prefixes for rpcap URLs.
  */
 static char rpcap_prefix[] = "rpcap://";
+static char rpcap_ssl_prefix[] = "rpcaps://";
 #endif
 
 static pcap_t *
@@ -1195,13 +1271,14 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
        /*
         * Is this an rpcap URL?
         */
-       if (strncmp(device, rpcap_prefix, sizeof(rpcap_prefix) - 1) == 0) {
+       if (strncmp(device, rpcap_prefix, sizeof(rpcap_prefix) - 1) == 0 ||
+           strncmp(device, rpcap_ssl_prefix, sizeof(rpcap_ssl_prefix) - 1) == 0) {
                /*
                 * Yes.  Open it with pcap_open().
                 */
                *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) {
                        /*
@@ -1243,9 +1320,9 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
        status = pcap_set_tstamp_precision(pc, ndo->ndo_tstamp_precision);
        if (status != 0)
                error("%s: Can't set %ssecond time stamp precision: %s",
-                       device,
-                       tstamp_precision_to_string(ndo->ndo_tstamp_precision),
-                       pcap_statustostr(status));
+                   device,
+                   tstamp_precision_to_string(ndo->ndo_tstamp_precision),
+                   pcap_statustostr(status));
 #endif
 
 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
@@ -1253,8 +1330,7 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                status = pcap_set_immediate_mode(pc, 1);
                if (status != 0)
                        error("%s: Can't set immediate mode: %s",
-                       device,
-                       pcap_statustostr(status));
+                           device, pcap_statustostr(status));
        }
 #endif
        /*
@@ -1284,7 +1360,7 @@ 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));
@@ -1299,7 +1375,11 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                status = pcap_set_tstamp_type(pc, jflag);
                if (status < 0)
                        error("%s: Can't set time stamp type: %s",
-                             device, pcap_statustostr(status));
+                           device, pcap_statustostr(status));
+               else if (status > 0)
+                       warning("When trying to set timestamp type '%s' on %s: %s",
+                           pcap_tstamp_type_val_to_name(jflag), device,
+                           pcap_statustostr(status));
        }
 #endif
        status = pcap_activate(pc);
@@ -1314,10 +1394,8 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                        /*
                         * Return an error for our caller to handle.
                         */
-                       nd_snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
+                       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);
@@ -1328,7 +1406,7 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
                        char sysctl[32];
                        size_t s = sizeof(parent);
 
-                       nd_snprintf(sysctl, sizeof(sysctl),
+                       snprintf(sysctl, sizeof(sysctl),
                            "net.wlan.%d.%%parent", atoi(device + 4));
                        sysctlbyname(sysctl, parent, &s, NULL, 0);
                        strlcpy(newdev, device, sizeof(newdev));
@@ -1348,6 +1426,8 @@ 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
@@ -1379,8 +1459,8 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
         * specified, default to 256KB.
         */
        if (ndo->ndo_snaplen == 0)
-               ndo->ndo_snaplen = 262144;
-       pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, 1000, ebuf);
+               ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
+       pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, timeout, ebuf);
        if (pc == NULL) {
                /*
                 * If this failed with "No such device", that means
@@ -1404,7 +1484,6 @@ main(int argc, char **argv)
 {
        int cnt, op, i;
        bpf_u_int32 localnet = 0, netmask = 0;
-       int timezone_offset = 0;
        char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
        char *endp;
        pcap_handler callback;
@@ -1418,8 +1497,10 @@ main(int argc, char **argv)
        u_char *pcap_userdata;
        char ebuf[PCAP_ERRBUF_SIZE];
        char VFileLine[PATH_MAX + 1];
-       char *username = NULL;
-       char *chroot_dir = NULL;
+       const char *username = NULL;
+#ifndef _WIN32
+       const char *chroot_dir = NULL;
+#endif
        char *ret = NULL;
        char *end;
 #ifdef HAVE_PCAP_FINDALLDEVS
@@ -1440,6 +1521,157 @@ main(int argc, char **argv)
        netdissect_options Ndo;
        netdissect_options *ndo = &Ndo;
 
+#ifdef _WIN32
+       /*
+        * We need to look for wpcap.dll in \Windows\System32\Npcap first,
+        * as either:
+        *
+        *  1) WinPcap isn't installed and Npcap isn't installed in "WinPcap
+        *     API-compatible Mode", so there's no wpcap.dll in
+        *     \Windows\System32, only in \Windows\System32\Npcap;
+        *
+        *  2) WinPcap is installed and Npcap isn't installed in "WinPcap
+        *     API-compatible Mode", so the wpcap.dll in \Windows\System32
+        *     is a WinPcap DLL, but we'd prefer an Npcap DLL (we should
+        *     work with either one if we're configured against WinPcap,
+        *     and we'll probably require Npcap if we're configured againt
+        *     it), and that's in \Windows\System32\Npcap;
+        *
+        *  3) Npcap is installed in "WinPcap API-compatible Mode", so both
+        *     \Windows\System32 and \Windows\System32\Npcap have an Npcap
+        *     wpcap.dll.
+        *
+        * Unfortunately, Windows has no notion of an rpath, so we can't
+        * set the rpath to include \Windows\System32\Npcap at link time;
+        * what we need to do is to link wpcap as a delay-load DLL and
+        * add \Windows\System32\Npcap to the DLL search path early in
+        * main() with a call to SetDllDirectory().
+        *
+        * The same applies to packet.dll.
+        *
+        * We add \Windows\System32\Npcap here.
+        *
+        * See https://npcap.com/guide/npcap-devguide.html#npcap-feature-native-dll-implicitly
+        */
+       WCHAR *dll_directory = NULL;
+       size_t dll_directory_buf_len = 0;       /* units of bytes */
+       UINT system_directory_buf_len = 0;      /* units of WCHARs */
+       UINT system_directory_len;              /* units of WCHARs */
+       static const WCHAR npcap[] = L"\\Npcap";
+
+       /*
+        * Get the system directory path, in UTF-16, into a buffer that's
+        * large enough for that directory path plus "\Npcap".
+        *
+        * String manipulation in C, plus fetching a variable-length
+        * string into a buffer whose size is fixed at the time of
+        * the call, with an oddball return value (see below), is just
+        * a huge bag of fun.
+        *
+        * And it's even more fun when dealing with UTF-16, so that the
+        * buffer sizes used in GetSystemDirectoryW() are in different
+        * units from the buffer sizes used in realloc()!   We maintain
+        * all sizes/length in units of bytes, not WCHARs, so that our
+        * heads don't explode.
+        */
+       for (;;) {
+               /*
+                * Try to fetch the system directory.
+                *
+                * GetSystemDirectoryW() expects a buffer size in units
+                * of WCHARs, not bytes, and returns a directory path
+                * length in units of WCHARs, not bytes.
+                *
+                * For extra fun, if GetSystemDirectoryW() succeeds,
+                * the return value is the length of the directory
+                * path in units of WCHARs, *not* including the
+                * terminating '\0', but if it fails because the
+                * path string wouldn't fit, the return value is
+                * the length of the directory path in units of WCHARs,
+                * *including* the terminating '\0'.
+                */
+               system_directory_len = GetSystemDirectoryW(dll_directory,
+                   system_directory_buf_len);
+               if (system_directory_len == 0)
+                       error("GetSystemDirectoryW() failed");
+
+               /*
+                * Did the directory path fit in the buffer?
+                *
+                * As per the above, this means that the return value
+                * *plus 1*, so that the terminating '\0' is counted,
+                * is <= the buffer size.
+                *
+                * (If the directory path, complete with the terminating
+                * '\0', fits *exactly*, the return value would be the
+                * size of the buffer minus 1, as it doesn't count the
+                * terminating '\0', so the test below would succeed.
+                *
+                * If everything *but* the terminating '\0' fits,
+                * the return value would be the size of the buffer + 1,
+                * i.e., the size that the string in question would
+                * have required.
+                *
+                * The astute reader will note that returning the
+                * size of the buffer is not one of the two cases
+                * above, and should never happen.)
+                */
+               if ((system_directory_len + 1) <= system_directory_buf_len) {
+                       /*
+                        * No.  We have a buffer that's large enough
+                        * for our purposes.
+                        */
+                       break;
+               }
+
+               /*
+                * Yes.  Grow the buffer.
+                *
+                * The space we'll need in the buffer for the system
+                * directory, in units of WCHARs, is system_directory_len,
+                * as that's the length of the system directory path
+                * including the terminating '\0'.
+                */
+               system_directory_buf_len = system_directory_len;
+
+               /*
+                * The size of the DLL directory buffer, in *bytes*, must
+                * be the number of WCHARs taken by the system directory,
+                * *minus* the terminating '\0' (as we'll overwrite that
+                * with the "\" of the "\Npcap" string), multiplied by
+                * sizeof(WCHAR) to convert it to the number of bytes,
+                * plus the size of the "\Npcap" string, in bytes (which
+                * will include the terminating '\0', as that will become
+                * the DLL path's terminating '\0').
+                */
+               dll_directory_buf_len =
+                   ((system_directory_len - 1)*sizeof(WCHAR)) + sizeof npcap;
+               dll_directory = realloc(dll_directory, dll_directory_buf_len);
+               if (dll_directory == NULL)
+                       error("Can't allocate string for Npcap directory");
+       }
+
+       /*
+        * OK, that worked.
+        *
+        * Now append \Npcap.  We add the length of the system directory path,
+        * in WCHARs, *not* including the terminating '\0' (which, since
+        * GetSystemDirectoryW() succeeded, is the return value of
+        * GetSystemDirectoryW(), as per the above), to the pointer to the
+        * beginning of the path, to go past the end of the system directory
+        * to point to the terminating '\0'.
+        */
+       memcpy(dll_directory + system_directory_len, npcap, sizeof npcap);
+
+       /*
+        * Now add that as a system DLL directory.
+        */
+       if (!SetDllDirectoryW(dll_directory))
+               error("SetDllDirectory failed");
+
+       free(dll_directory);
+#endif
+
        /*
         * Initialize the netdissect code.
         */
@@ -1457,7 +1689,7 @@ 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];
@@ -1480,6 +1712,13 @@ 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) {
@@ -1581,13 +1820,13 @@ 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;
 
@@ -1636,6 +1875,7 @@ main(int argc, char **argv)
                        setvbuf(stdout, NULL, _IOLBF, 0);
 #endif
 #endif /* _WIN32 */
+                       lflag = 1;
                        break;
 
                case 'K':
@@ -1647,7 +1887,7 @@ 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");
                        }
@@ -1691,7 +1931,7 @@ 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 */
 
@@ -1700,10 +1940,11 @@ main(int argc, char **argv)
                        break;
 
                case 's':
-                       ndo->ndo_snaplen = strtol(optarg, &end, 0);
+                       ndo->ndo_snaplen = (int)strtol(optarg, &end, 0);
                        if (optarg == end || *end != '\0'
                            || ndo->ndo_snaplen < 0 || ndo->ndo_snaplen > MAXIMUM_SNAPLEN)
-                               error("invalid snaplen %s", optarg);
+                               error("invalid snaplen %s (must be >= 0 and <= %d)",
+                                     optarg, MAXIMUM_SNAPLEN);
                        break;
 
                case 'S':
@@ -1749,8 +1990,14 @@ main(int argc, char **argv)
                                ndo->ndo_packettype = PT_LMP;
                        else if (ascii_strcasecmp(optarg, "resp") == 0)
                                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);
+                               error("unknown packet type '%s'", optarg);
                        break;
 
                case 'u':
@@ -1820,8 +2067,12 @@ main(int argc, char **argv)
                        ndo->ndo_packet_number = 1;
                        break;
 
+               case OPTION_TIME_T_SIZE:
+                       printf("%zu\n", sizeof(time_t) * 8);
+                       return 0;
+
                case OPTION_VERSION:
-                       print_version();
+                       print_version(stdout);
                        exit_tcpdump(S_SUCCESS);
                        break;
 
@@ -1843,12 +2094,44 @@ main(int argc, char **argv)
                        print = 1;
                        break;
 
+#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
+               case OPTION_TSTAMP_MICRO:
+                       ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
+                       break;
+
+               case OPTION_TSTAMP_NANO:
+                       ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_NANO;
+                       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 */
                }
 
+       if (ndo->ndo_Aflag && ndo->ndo_xflag)
+               warning("-A and -x[x] are mutually exclusive. -A ignored.");
+       if (ndo->ndo_Aflag && ndo->ndo_Xflag)
+               warning("-A and -X[X] are mutually exclusive. -A ignored.");
+       if (ndo->ndo_xflag && ndo->ndo_Xflag)
+               warning("-x[x] and -X[X] are mutually exclusive. -x[x] ignored.");
+
 #ifdef HAVE_PCAP_FINDALLDEVS
        if (Dflag)
                show_devices_and_exit();
@@ -1861,14 +2144,11 @@ main(int argc, char **argv)
        switch (ndo->ndo_tflag) {
 
        case 0: /* Default */
-       case 4: /* Default + Date*/
-               timezone_offset = 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 */
+       case 3: /* Microseconds/nanoseconds since previous packet */
+       case 4: /* Date + Default */
+       case 5: /* Microseconds/nanoseconds since first packet */
                break;
 
        default: /* Not supported */
@@ -1882,19 +2162,18 @@ 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 */
@@ -1911,6 +2190,8 @@ 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
 
@@ -1970,15 +2251,41 @@ main(int argc, char **argv)
 #endif
                dlt = pcap_datalink(pd);
                dlt_name = pcap_datalink_val_to_name(dlt);
+               fprintf(stderr, "reading from file %s", RFileName);
                if (dlt_name == NULL) {
-                       fprintf(stderr, "reading from file %s, link-type %u\n",
-                           RFileName, dlt);
+                       fprintf(stderr, ", link-type %u", dlt);
                } else {
-                       fprintf(stderr,
-                           "reading from file %s, link-type %s (%s)\n",
-                           RFileName, dlt_name,
-                           pcap_datalink_val_to_description(dlt));
+                       fprintf(stderr, ", link-type %s (%s)", dlt_name,
+                               pcap_datalink_val_to_description(dlt));
                }
+               fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
+#ifdef DLT_LINUX_SLL2
+               if (dlt == DLT_LINUX_SLL2)
+                       fprintf(stderr, "Warning: interface names might be incorrect\n");
+#endif
+       } else if (dflag && !device) {
+               int dump_dlt = DLT_EN10MB;
+               /*
+                * We're dumping the compiled code without an explicit
+                * device specification.  (If a device is specified, we
+                * definitely want to open it to use the DLT of that device.)
+                * Either default to DLT_EN10MB with a warning, or use
+                * the user-specified value if supplied.
+                */
+               /*
+                * If no snapshot length was specified, or a length of 0 was
+                * specified, default to 256KB.
+                */
+               if (ndo->ndo_snaplen == 0)
+                       ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
+               /*
+                * If a DLT was specified with the -y flag, use that instead.
+                */
+               if (yflag_dlt != -1)
+                       dump_dlt = yflag_dlt;
+               else
+                       fprintf(stderr, "Warning: assuming Ethernet\n");
+               pd = pcap_open_dead(dump_dlt, ndo->ndo_snaplen);
        } else {
                /*
                 * We're doing a live capture.
@@ -2084,9 +2391,28 @@ 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);
                }
+#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)
@@ -2126,7 +2452,7 @@ main(int argc, char **argv)
                capdns = capdns_setup();
 #endif /* HAVE_CASPER */
 
-       init_print(ndo, localnet, netmask, timezone_offset);
+       init_print(ndo, localnet, netmask);
 
 #ifndef _WIN32
        (void)setsignal(SIGPIPE, cleanup);
@@ -2138,7 +2464,21 @@ main(int argc, char **argv)
 #endif
        /* Cooperate with nohup(1) */
 #ifndef _WIN32
+       /*
+        * In illumos /usr/include/sys/iso/signal_iso.h causes Clang to
+        * generate a -Wstrict-prototypes warning here, see [1].  The
+        * __illumos__ macro is available since at least GCC 11 and Clang 13,
+        * see [2].
+        * 1: https://www.illumos.org/issues/16344
+        * 2: https://www.illumos.org/issues/13726
+        */
+#ifdef __illumos__
+       DIAG_OFF_STRICT_PROTOTYPES
+#endif /* __illumos__ */
        if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
+#ifdef __illumos__
+       DIAG_ON_STRICT_PROTOTYPES
+#endif /* __illumos__ */
                (void)setsignal(SIGHUP, oldhandler);
 #endif /* _WIN32 */
 
@@ -2166,33 +2506,33 @@ 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 */
@@ -2254,21 +2594,48 @@ DIAG_ON_CLANG(assign-enum)
                if (pdd == NULL)
                        error("%s", pcap_geterr(pd));
 #ifdef HAVE_CAPSICUM
-               set_dumper_capsicum_rights(p);
+               set_dumper_capsicum_rights(pdd);
 #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 &&
@@ -2295,7 +2662,7 @@ 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;
@@ -2306,7 +2673,7 @@ 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;
        }
@@ -2323,11 +2690,14 @@ 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
                /*
@@ -2365,20 +2735,20 @@ 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);
                dlt = pcap_datalink(pd);
                dlt_name = pcap_datalink_val_to_name(dlt);
+               (void)fprintf(stderr, "listening on %s", device);
                if (dlt_name == NULL) {
-                       (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
-                           device, dlt, ndo->ndo_snaplen);
+                       (void)fprintf(stderr, ", link-type %u", dlt);
                } 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), ndo->ndo_snaplen);
+                       (void)fprintf(stderr, ", link-type %s (%s)", dlt_name,
+                                     pcap_datalink_val_to_description(dlt));
                }
+               (void)fprintf(stderr, ", snapshot length %d bytes\n", ndo->ndo_snaplen);
                (void)fflush(stderr);
        }
 
@@ -2389,6 +2759,9 @@ 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 */
@@ -2479,7 +2852,9 @@ 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);
+                                       /* Free the old filter */
+                                       pcap_freecode(&fcode);
                                        if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
                                                error("%s", pcap_geterr(pd));
                                }
@@ -2494,23 +2869,27 @@ DIAG_ON_CLANG(assign-enum)
                                 * Report the new file.
                                 */
                                dlt_name = pcap_datalink_val_to_name(dlt);
+                               fprintf(stderr, "reading from file %s", RFileName);
                                if (dlt_name == NULL) {
-                                       fprintf(stderr, "reading from file %s, link-type %u\n",
-                                           RFileName, dlt);
+                                       fprintf(stderr, ", link-type %u", dlt);
                                } else {
-                                       fprintf(stderr,
-                                       "reading from file %s, link-type %s (%s)\n",
-                                           RFileName, dlt_name,
-                                           pcap_datalink_val_to_description(dlt));
+                                       fprintf(stderr, ", link-type %s (%s)",
+                                               dlt_name,
+                                               pcap_datalink_val_to_description(dlt));
                                }
+                               fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
                        }
                }
        }
        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);
+       exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS);
 }
 
 /*
@@ -2526,10 +2905,24 @@ 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)
+               /* The same workaround as for SIG_DFL above. */
+#ifdef __illumos__
+               DIAG_OFF_STRICT_PROTOTYPES
+#endif /* __illumos__ */
                return (SIG_ERR);
+#ifdef __illumos__
+               DIAG_ON_STRICT_PROTOTYPES
+#endif /* __illumos__ */
        return (old.sa_handler);
 #endif
 }
@@ -2591,7 +2984,7 @@ cleanup(int signo _U_)
 static void
 child_cleanup(int signo _U_)
 {
-  wait(NULL);
+  while (waitpid(-1, NULL, WNOHANG) >= 0);
 }
 #endif /* HAVE_FORK && HAVE_VFORK */
 
@@ -2718,8 +3111,8 @@ 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));
                }
 
 
@@ -2860,7 +3253,7 @@ 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);
@@ -2940,7 +3333,8 @@ 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)
@@ -2995,9 +3389,9 @@ 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
@@ -3008,56 +3402,63 @@ 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);
-#ifdef HAVE_DNET_HTOA
-       (void)fprintf(stderr, "libdnet unknown version\n");
-#endif
+               (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 */
+       (void)fprintf (f, "%zu-bit build, %zu-bit time_t\n",
+                      sizeof(void *) * 8, sizeof(time_t) * 8);
 }
-USES_APPLE_RST
+DIAG_ON_DEPRECATION
 
 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
-       (void)fprintf(stderr,
+#ifdef USE_LIBSMI
+       (void)fprintf(f,
+"\t\t" m_FLAG_USAGE "\n");
+#endif
+       (void)fprintf(f,
 "\t\t[ -M secret ] [ --number ] [ --print ]" Q_FLAG_USAGE "\n");
-       (void)fprintf(stderr,
-"\t\t[ -r file ] [ -s snaplen ]" TIME_STAMP_PRECISION_USAGE "\n");
-       (void)fprintf(stderr,
-"\t\t[ -T type ] [ --version ] [ -V file ] [ -w file ]\n");
-       (void)fprintf(stderr,
-"\t\t[ -W filecount ] [ -y datalinktype ]\n");
-       (void)fprintf(stderr,
+       (void)fprintf(f,
+"\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ --version ]\n");
+       (void)fprintf(f,
+"\t\t[ -V file ] [ -w file ] [ -W filecount ] [ -y datalinktype ]\n");
+#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
+       (void)fprintf(f,
+"\t\t[ --time-stamp-precision precision ] [ --micro ] [ --nano ]\n");
+#endif
+       (void)fprintf(f,
 "\t\t[ -z postrotate-command ] [ -Z user ] [ expression ]\n");
 }