]> The Tcpdump Group git mirrors - tcpdump/blobdiff - tcpdump.c
Handle very large -f files by rejecting them.
[tcpdump] / tcpdump.c
index 13becf7ee69a9b31a5614c65b47da91f02a31011..8f27ba2a47fbbf80700df196f679449c10e84f28 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -32,7 +32,7 @@ The Regents of the University of California.  All rights reserved.\n";
 #endif
 
 /*
- * tcpdump - monitor tcp/ip traffic on an ethernet.
+ * tcpdump - dump traffic on a network
  *
  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
  * Mercilessly hacked and occasionally improved since then via the
@@ -54,17 +54,12 @@ The Regents of the University of California.  All rights reserved.\n";
 #endif
 #endif
 
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
 
-#ifdef WIN32
-#include "w32_fzs.h"
-extern int SIZE_BUF;
-#define off_t long
-#define uint UINT
-#endif /* WIN32 */
+#include <sys/stat.h>
 
-#ifdef USE_LIBSMI
-#include <smi.h>
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
 #endif
 
 #ifdef HAVE_LIBCRYPTO
@@ -84,21 +79,21 @@ extern int SIZE_BUF;
 #include <sys/capability.h>
 #include <sys/ioccom.h>
 #include <net/bpf.h>
-#include <fcntl.h>
 #include <libgen.h>
 #endif /* HAVE_CAPSICUM */
 #include <pcap.h>
 #include <signal.h>
 #include <stdio.h>
+#include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
 #include <limits.h>
-#ifndef WIN32
+#ifndef _WIN32
 #include <sys/wait.h>
 #include <sys/resource.h>
 #include <pwd.h>
 #include <grp.h>
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
 /* capabilities convenience library */
 /* If a code depends on HAVE_LIBCAP_NG, it depends also on HAVE_CAP_NG_H.
@@ -113,6 +108,7 @@ extern int SIZE_BUF;
 #endif /* HAVE_CAP_NG_H */
 #endif /* HAVE_LIBCAP_NG */
 
+#include "netdissect-stdinc.h"
 #include "netdissect.h"
 #include "interface.h"
 #include "addrtoname.h"
@@ -134,10 +130,23 @@ extern int SIZE_BUF;
 #define SIGNAL_REQ_INFO SIGUSR1
 #endif
 
-static int Cflag;                      /* rotate dump files after this many bytes */
+static int Bflag;                      /* buffer size */
+static long Cflag;                     /* rotate dump files after this many bytes */
 static int Cflag_count;                        /* Keep track of which file number we're writing */
 static int Dflag;                      /* list available devices and exit */
-static int dflag;                      /* print filter code */
+/*
+ * This is exported because, in some versions of libpcap, if libpcap
+ * is built with optimizer debugging code (which is *NOT* the default
+ * configuration!), the library *imports*(!) a variable named dflag,
+ * under the expectation that tcpdump is exporting it, to govern
+ * how much debugging information to print when optimizing
+ * the generated BPF code.
+ *
+ * This is a horrible hack; newer versions of libpcap don't import
+ * dflag but, instead, *if* built with optimizer debugging code,
+ * *export* a routine to set that flag.
+ */
+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 */
 static time_t Gflag_time;              /* The last time_t the dump file was rotated. */
@@ -146,13 +155,16 @@ 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 */
+static int pflag;                      /* don't go promiscuous */
 #ifdef HAVE_PCAP_SETDIRECTION
-int Qflag = -1;                                /* restrict captured packet by send/receive direction */
+static int Qflag = -1;                 /* restrict captured packet by send/receive direction */
 #endif
 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 immediate_mode;
 
 static int infodelay;
 static int infoprint;
@@ -160,11 +172,18 @@ static int infoprint;
 char *program_name;
 
 /* Forwards */
+static void error(FORMAT_STRING(const char *), ...) NORETURN PRINTFLIKE(1, 2);
+static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
+static void exit_tcpdump(int) NORETURN;
 static RETSIGTYPE cleanup(int);
 static RETSIGTYPE child_cleanup(int);
 static void print_version(void);
 static void print_usage(void);
-static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
+static void show_tstamp_types_and_exit(pcap_t *, const char *device) NORETURN;
+static void show_dlts_and_exit(pcap_t *, const char *device) NORETURN;
+#ifdef HAVE_PCAP_FINDALLDEVS
+static void show_devices_and_exit (void) NORETURN;
+#endif
 
 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 *);
@@ -186,6 +205,7 @@ RETSIGTYPE requestinfo(int);
 static void info(int);
 static u_int packets_captured;
 
+#ifdef HAVE_PCAP_FINDALLDEVS
 static const struct tok status_flags[] = {
 #ifdef PCAP_IF_UP
        { PCAP_IF_UP,       "Up"       },
@@ -196,6 +216,7 @@ static const struct tok status_flags[] = {
        { PCAP_IF_LOOPBACK, "Loopback" },
        { 0, NULL }
 };
+#endif
 
 static pcap_t *pd;
 
@@ -215,23 +236,117 @@ struct dump_info {
 #endif
 };
 
+#if defined(HAVE_PCAP_SET_PARSER_DEBUG)
+/*
+ * We have pcap_set_parser_debug() in libpcap; declare it (it's not declared
+ * by any libpcap header, because it's a special hack, only available if
+ * libpcap was configured to include it, and only intended for use by
+ * libpcap developers trying to debug the parser for filter expressions).
+ */
+#ifdef _WIN32
+__declspec(dllimport)
+#else /* _WIN32 */
+extern
+#endif /* _WIN32 */
+void pcap_set_parser_debug(int);
+#elif defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
+/*
+ * We don't have pcap_set_parser_debug() in libpcap, but we do have
+ * pcap_debug or yydebug.  Make a local version of pcap_set_parser_debug()
+ * to set the flag, and define HAVE_PCAP_SET_PARSER_DEBUG.
+ */
+static void
+pcap_set_parser_debug(int value)
+{
+#ifdef HAVE_PCAP_DEBUG
+       extern int pcap_debug;
+
+       pcap_debug = value;
+#else /* HAVE_PCAP_DEBUG */
+       extern int yydebug;
+
+       yydebug = value;
+#endif /* HAVE_PCAP_DEBUG */
+}
+
+#define HAVE_PCAP_SET_PARSER_DEBUG
+#endif
+
+#if defined(HAVE_PCAP_SET_OPTIMIZER_DEBUG)
+/*
+ * We have pcap_set_optimizer_debug() in libpcap; declare it (it's not declared
+ * by any libpcap header, because it's a special hack, only available if
+ * libpcap was configured to include it, and only intended for use by
+ * libpcap developers trying to debug the optimizer for filter expressions).
+ */
+#ifdef _WIN32
+__declspec(dllimport)
+#else /* _WIN32 */
+extern
+#endif /* _WIN32 */
+void pcap_set_optimizer_debug(int);
+#endif
+
+/* VARARGS */
+static void
+error(const char *fmt, ...)
+{
+       va_list ap;
+
+       (void)fprintf(stderr, "%s: ", program_name);
+       va_start(ap, fmt);
+       (void)vfprintf(stderr, fmt, ap);
+       va_end(ap);
+       if (*fmt) {
+               fmt += strlen(fmt);
+               if (fmt[-1] != '\n')
+                       (void)fputc('\n', stderr);
+       }
+       exit_tcpdump(1);
+       /* NOTREACHED */
+}
+
+/* VARARGS */
+static void
+warning(const char *fmt, ...)
+{
+       va_list ap;
+
+       (void)fprintf(stderr, "%s: WARNING: ", program_name);
+       va_start(ap, fmt);
+       (void)vfprintf(stderr, fmt, ap);
+       va_end(ap);
+       if (*fmt) {
+               fmt += strlen(fmt);
+               if (fmt[-1] != '\n')
+                       (void)fputc('\n', stderr);
+       }
+}
+
+static void
+exit_tcpdump(int status)
+{
+       nd_cleanup();
+       exit(status);
+}
+
 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 static void
-show_tstamp_types_and_exit(const char *device, pcap_t *pd)
+show_tstamp_types_and_exit(pcap_t *pc, const char *device)
 {
        int n_tstamp_types;
        int *tstamp_types = 0;
        const char *tstamp_type_name;
        int i;
 
-       n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
+       n_tstamp_types = pcap_list_tstamp_types(pc, &tstamp_types);
        if (n_tstamp_types < 0)
-               error("%s", pcap_geterr(pd));
+               error("%s", pcap_geterr(pc));
 
        if (n_tstamp_types == 0) {
                fprintf(stderr, "Time stamp type cannot be set for %s\n",
                    device);
-               exit(0);
+               exit_tcpdump(0);
        }
        fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
            device);
@@ -245,20 +360,20 @@ show_tstamp_types_and_exit(const char *device, pcap_t *pd)
                }
        }
        pcap_free_tstamp_types(tstamp_types);
-       exit(0);
+       exit_tcpdump(0);
 }
 #endif
 
 static void
-show_dlts_and_exit(const char *device, pcap_t *pd)
+show_dlts_and_exit(pcap_t *pc, const char *device)
 {
        int n_dlts, i;
        int *dlts = 0;
        const char *dlt_name;
 
-       n_dlts = pcap_list_datalinks(pd, &dlts);
+       n_dlts = pcap_list_datalinks(pc, &dlts);
        if (n_dlts < 0)
-               error("%s", pcap_geterr(pd));
+               error("%s", pcap_geterr(pc));
        else if (n_dlts == 0 || !dlts)
                error("No data link types.");
 
@@ -298,31 +413,29 @@ show_dlts_and_exit(const char *device, pcap_t *pd)
 #ifdef HAVE_PCAP_FREE_DATALINKS
        pcap_free_datalinks(dlts);
 #endif
-       exit(0);
+       exit_tcpdump(0);
 }
 
 #ifdef HAVE_PCAP_FINDALLDEVS
 static void
 show_devices_and_exit (void)
 {
-       pcap_if_t *devpointer;
+       pcap_if_t *dev, *devlist;
        char ebuf[PCAP_ERRBUF_SIZE];
        int i;
 
-       if (pcap_findalldevs(&devpointer, ebuf) < 0)
+       if (pcap_findalldevs(&devlist, ebuf) < 0)
                error("%s", ebuf);
-       else {
-               for (i = 0; devpointer != NULL; i++) {
-                       printf("%d.%s", i+1, devpointer->name);
-                       if (devpointer->description != NULL)
-                               printf(" (%s)", devpointer->description);
-                       if (devpointer->flags != 0)
-                               printf(" [%s]", bittok2str(status_flags, "none", devpointer->flags));
-                       printf("\n");
-                       devpointer = devpointer->next;
-               }
+       for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
+               printf("%d.%s", i+1, dev->name);
+               if (dev->description != NULL)
+                       printf(" (%s)", dev->description);
+               if (dev->flags != 0)
+                       printf(" [%s]", bittok2str(status_flags, "none", dev->flags));
+               printf("\n");
        }
-       exit(0);
+       pcap_freealldevs(devlist);
+       exit_tcpdump(0);
 }
 #endif /* HAVE_PCAP_FINDALLDEVS */
 
@@ -337,7 +450,7 @@ show_devices_and_exit (void)
  * OS X tcpdump uses -g to force non--v output for IP to be on one
  * line, making it more "g"repable;
  *
- * OS X tcpdump uses -k tospecify that packet comments in pcap-ng files
+ * OS X tcpdump uses -k to specify that packet comments in pcap-ng files
  * should be printed;
  *
  * OpenBSD tcpdump uses -o to indicate that OS fingerprinting should be done
@@ -360,13 +473,13 @@ show_devices_and_exit (void)
  * Set up flags that might or might not be supported depending on the
  * version of libpcap we're using.
  */
-#if defined(HAVE_PCAP_CREATE) || defined(WIN32)
+#if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
 #define B_FLAG         "B:"
 #define B_FLAG_USAGE   " [ -B size ]"
-#else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
+#else /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
 #define B_FLAG
 #define B_FLAG_USAGE
-#endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
+#endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
 
 #ifdef HAVE_PCAP_CREATE
 #define I_FLAG         "I"
@@ -402,7 +515,7 @@ show_devices_and_exit (void)
 #define Q_FLAG
 #endif
 
-#define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" Q_FLAG "r:Rs:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
+#define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" Q_FLAG "r:s:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
 
 /*
  * Long options.
@@ -429,7 +542,7 @@ show_devices_and_exit (void)
 #define OPTION_IMMEDIATE_MODE  130
 
 static const struct option longopts[] = {
-#if defined(HAVE_PCAP_CREATE) || defined(WIN32)
+#if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
        { "buffer-size", required_argument, NULL, 'B' },
 #endif
        { "list-interfaces", no_argument, NULL, 'D' },
@@ -461,7 +574,7 @@ static const struct option longopts[] = {
 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
        { "immediate-mode", no_argument, NULL, OPTION_IMMEDIATE_MODE },
 #endif
-#if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
+#ifdef HAVE_PCAP_SET_PARSER_DEBUG
        { "debug-filter-parser", no_argument, NULL, 'Y' },
 #endif
        { "relinquish-privileges", required_argument, NULL, 'Z' },
@@ -470,7 +583,7 @@ static const struct option longopts[] = {
        { NULL, 0, NULL, 0 }
 };
 
-#ifndef WIN32
+#ifndef _WIN32
 /* Drop root privileges and chroot if necessary */
 static void
 droproot(const char *username, const char *chroot_dir)
@@ -478,36 +591,37 @@ droproot(const char *username, const char *chroot_dir)
        struct passwd *pw = NULL;
 
        if (chroot_dir && !username) {
-               fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
-               exit(1);
+               fprintf(stderr, "%s: Chroot without dropping root is insecure\n",
+                       program_name);
+               exit_tcpdump(1);
        }
 
        pw = getpwnam(username);
        if (pw) {
                if (chroot_dir) {
                        if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
-                               fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
-                                   chroot_dir, pcap_strerror(errno));
-                               exit(1);
+                               fprintf(stderr, "%s: Couldn't chroot/chdir to '%.64s': %s\n",
+                                       program_name, chroot_dir, pcap_strerror(errno));
+                               exit_tcpdump(1);
                        }
                }
 #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 {
-                       fprintf(stderr, "dropped privs to %s\n", username);
+               {
+                       int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
+                       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 ||
                    setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
-                       fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
-                           username,
-                           (unsigned long)pw->pw_uid,
-                           (unsigned long)pw->pw_gid,
-                           pcap_strerror(errno));
-                       exit(1);
+                       fprintf(stderr, "%s: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
+                               program_name, username,
+                               (unsigned long)pw->pw_uid,
+                               (unsigned long)pw->pw_gid,
+                               pcap_strerror(errno));
+                       exit_tcpdump(1);
                }
                else {
                        fprintf(stderr, "dropped privs to %s\n", username);
@@ -515,23 +629,24 @@ droproot(const char *username, const char *chroot_dir)
 #endif /* HAVE_LIBCAP_NG */
        }
        else {
-               fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
-                   username);
-               exit(1);
+               fprintf(stderr, "%s: Couldn't find user '%.32s'\n",
+                       program_name, username);
+               exit_tcpdump(1);
        }
 #ifdef HAVE_LIBCAP_NG
-       /* We don't need CAP_SETUID and CAP_SETGID any more. */
+       /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */
        capng_updatev(
                CAPNG_DROP,
                CAPNG_EFFECTIVE | CAPNG_PERMITTED,
                CAP_SETUID,
                CAP_SETGID,
+               CAP_SYS_CHROOT,
                -1);
        capng_apply(CAPNG_SELECT_BOTH);
 #endif /* HAVE_LIBCAP_NG */
 
 }
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
 static int
 getWflagChars(int x)
@@ -585,13 +700,15 @@ 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;
 }
@@ -696,6 +813,299 @@ set_dumper_capsicum_rights(pcap_dumper_t *p)
 }
 #endif
 
+/*
+ * Copy arg vector into a new buffer, concatenating arguments with spaces.
+ */
+static char *
+copy_argv(register char **argv)
+{
+       register char **p;
+       register u_int len = 0;
+       char *buf;
+       char *src, *dst;
+
+       p = argv;
+       if (*p == NULL)
+               return 0;
+
+       while (*p)
+               len += strlen(*p++) + 1;
+
+       buf = (char *)malloc(len);
+       if (buf == NULL)
+               error("copy_argv: malloc");
+
+       p = argv;
+       dst = buf;
+       while ((src = *p++) != NULL) {
+               while ((*dst++ = *src++) != '\0')
+                       ;
+               dst[-1] = ' ';
+       }
+       dst[-1] = '\0';
+
+       return buf;
+}
+
+/*
+ * On Windows, we need to open the file in binary mode, so that
+ * we get all the bytes specified by the size we get from "fstat()".
+ * On UNIX, that's not necessary.  O_BINARY is defined on Windows;
+ * we define it as 0 if it's not defined, so it does nothing.
+ */
+#ifndef O_BINARY
+#define O_BINARY       0
+#endif
+
+static char *
+read_infile(char *fname)
+{
+       register int i, fd, cc;
+       register char *cp;
+       our_statb buf;
+
+       fd = open(fname, O_RDONLY|O_BINARY);
+       if (fd < 0)
+               error("can't open %s: %s", fname, pcap_strerror(errno));
+
+       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,
+                       fname, pcap_strerror(errno));
+       cc = read(fd, cp, (u_int)buf.st_size);
+       if (cc < 0)
+               error("read %s: %s", fname, pcap_strerror(errno));
+       if (cc != buf.st_size)
+               error("short read %s (%d != %d)", fname, (int) cc,
+                   (int)buf.st_size);
+
+       close(fd);
+       /* replace "# comment" with spaces */
+       for (i = 0; i < cc; i++) {
+               if (cp[i] == '#')
+                       while (i < cc && cp[i] != '\n')
+                               cp[i++] = ' ';
+       }
+       cp[cc] = '\0';
+       return (cp);
+}
+
+#ifdef HAVE_PCAP_FINDALLDEVS
+static long
+parse_interface_number(const char *device)
+{
+       long devnum;
+       char *end;
+
+       devnum = strtol(device, &end, 10);
+       if (device != end && *end == '\0') {
+               /*
+                * It's all-numeric, but is it a valid number?
+                */
+               if (devnum <= 0) {
+                       /*
+                        * No, it's not an ordinal.
+                        */
+                       error("Invalid adapter index");
+               }
+               return (devnum);
+       } else {
+               /*
+                * It's not all-numeric; return -1, so our caller
+                * knows that.
+                */
+               return (-1);
+       }
+}
+
+static char *
+find_interface_by_number(long devnum)
+{
+       pcap_if_t *dev, *devlist;
+       long i;
+       char ebuf[PCAP_ERRBUF_SIZE];
+       char *device;
+
+       if (pcap_findalldevs(&devlist, ebuf) < 0)
+               error("%s", ebuf);
+       /*
+        * Look for the devnum-th entry in the list of devices (1-based).
+        */
+       for (i = 0, dev = devlist; i < devnum-1 && dev != NULL;
+           i++, dev = dev->next)
+               ;
+       if (dev == NULL)
+               error("Invalid adapter index");
+       device = strdup(dev->name);
+       pcap_freealldevs(devlist);
+       return (device);
+}
+#endif
+
+static pcap_t *
+open_interface(const char *device, netdissect_options *ndo, char *ebuf)
+{
+       pcap_t *pc;
+#ifdef HAVE_PCAP_CREATE
+       int status;
+       char *cp;
+#endif
+
+#ifdef HAVE_PCAP_CREATE
+       pc = pcap_create(device, ebuf);
+       if (pc == NULL) {
+               /*
+                * If this failed with "No such device", that means
+                * the interface doesn't exist; return NULL, so that
+                * the caller can see whether the device name is
+                * actually an interface index.
+                */
+               if (strstr(ebuf, "No such device") != NULL)
+                       return (NULL);
+               error("%s", ebuf);
+       }
+#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
+       if (Jflag)
+               show_tstamp_types_and_exit(pc, device);
+#endif
+#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
+       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));
+#endif
+
+#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
+       if (immediate_mode) {
+               status = pcap_set_immediate_mode(pc, 1);
+               if (status != 0)
+                       error("%s: Can't set immediate mode: %s",
+                       device,
+                       pcap_statustostr(status));
+       }
+#endif
+       /*
+        * Is this an interface that supports monitor mode?
+        */
+       if (pcap_can_set_rfmon(pc) == 1)
+               supports_monitor_mode = 1;
+       else
+               supports_monitor_mode = 0;
+       status = pcap_set_snaplen(pc, ndo->ndo_snaplen);
+       if (status != 0)
+               error("%s: Can't set snapshot length: %s",
+                   device, pcap_statustostr(status));
+       status = pcap_set_promisc(pc, !pflag);
+       if (status != 0)
+               error("%s: Can't set promiscuous mode: %s",
+                   device, pcap_statustostr(status));
+       if (Iflag) {
+               status = pcap_set_rfmon(pc, 1);
+               if (status != 0)
+                       error("%s: Can't set monitor mode: %s",
+                           device, pcap_statustostr(status));
+       }
+       status = pcap_set_timeout(pc, 1000);
+       if (status != 0)
+               error("%s: pcap_set_timeout failed: %s",
+                   device, pcap_statustostr(status));
+       if (Bflag != 0) {
+               status = pcap_set_buffer_size(pc, Bflag);
+               if (status != 0)
+                       error("%s: Can't set buffer size: %s",
+                           device, pcap_statustostr(status));
+       }
+#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
+       if (jflag != -1) {
+               status = pcap_set_tstamp_type(pc, jflag);
+               if (status < 0)
+                       error("%s: Can't set time stamp type: %s",
+                             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);
+       if (status < 0) {
+               /*
+                * pcap_activate() failed.
+                */
+               cp = pcap_geterr(pc);
+               if (status == PCAP_ERROR)
+                       error("%s", cp);
+               else if (status == PCAP_ERROR_NO_SUCH_DEVICE) {
+                       /*
+                        * Return an error for our caller to handle.
+                        */
+                       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);
+               else
+                       error("%s: %s", device,
+                           pcap_statustostr(status));
+       } else if (status > 0) {
+               /*
+                * pcap_activate() succeeded, but it's warning us
+                * of a problem it had.
+                */
+               cp = pcap_geterr(pc);
+               if (status == PCAP_WARNING)
+                       warning("%s", cp);
+               else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
+                        *cp != '\0')
+                       warning("%s: %s\n(%s)", device,
+                           pcap_statustostr(status), cp);
+               else
+                       warning("%s: %s", device,
+                           pcap_statustostr(status));
+       }
+#ifdef HAVE_PCAP_SETDIRECTION
+       if (Qflag != -1) {
+               status = pcap_setdirection(pc, Qflag);
+               if (status != 0)
+                       error("%s: pcap_setdirection() failed: %s",
+                             device,  pcap_geterr(pc));
+               }
+#endif /* HAVE_PCAP_SETDIRECTION */
+#else /* HAVE_PCAP_CREATE */
+       *ebuf = '\0';
+       pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, 1000, ebuf);
+       if (pc == NULL) {
+               /*
+                * If this failed with "No such device", that means
+                * the interface doesn't exist; return NULL, so that
+                * the caller can see whether the device name is
+                * actually an interface index.
+                */
+               if (strstr(ebuf, "No such device") != NULL)
+                       return (NULL);
+               error("%s", ebuf);
+       }
+       if (*ebuf)
+               warning("%s", ebuf);
+#endif /* HAVE_PCAP_CREATE */
+
+       return (pc);
+}
+
 int
 main(int argc, char **argv)
 {
@@ -704,15 +1114,12 @@ main(int argc, char **argv)
        int timezone_offset = 0;
        register char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
        pcap_handler callback;
-       int type;
        int dlt;
-       int new_dlt;
        const char *dlt_name;
        struct bpf_program fcode;
-#ifndef WIN32
+#ifndef _WIN32
        RETSIGTYPE (*oldhandler)(int);
 #endif
-       struct print_info printinfo;
        struct dump_info dumpinfo;
        u_char *pcap_userdata;
        char ebuf[PCAP_ERRBUF_SIZE];
@@ -722,8 +1129,8 @@ main(int argc, char **argv)
        char *ret = NULL;
        char *end;
 #ifdef HAVE_PCAP_FINDALLDEVS
-       pcap_if_t *devpointer;
-       int devnum;
+       pcap_if_t *devlist;
+       long devnum;
 #endif
        int status;
        FILE *VFile;
@@ -731,23 +1138,22 @@ main(int argc, char **argv)
        cap_rights_t rights;
        int cansandbox;
 #endif /* HAVE_CAPSICUM */
-       int Bflag=0;                    /* buffer size */
-       int jflag=-1;                   /* packet time stamp source */
-       int Oflag=1;                    /* run filter code optimizer */
-       int pflag=0;                    /* don't go promiscuous */
+       int Oflag = 1;                  /* run filter code optimizer */
+       int yflag_dlt = -1;
+       const char *yflag_dlt_name = NULL;
+
        netdissect_options Ndo;
        netdissect_options *ndo = &Ndo;
 
-#ifdef WIN32
-       if(wsockinit() != 0) return 1;
-#endif /* WIN32 */
+       /*
+        * Initialize the netdissect code.
+        */
+       if (nd_init(ebuf, sizeof ebuf) == -1)
+               error("%s", ebuf);
 
        memset(ndo, 0, sizeof(*ndo));
-       ndo->ndo_Rflag=1;
-       ndo->ndo_dlt=-1;
        ndo_set_function_pointers(ndo);
        ndo->ndo_snaplen = DEFAULT_SNAPLEN;
-       ndo->ndo_immediate = 0;
 
        cnt = -1;
        device = NULL;
@@ -758,9 +1164,14 @@ main(int argc, char **argv)
        WFileName = NULL;
        dlt = -1;
        if ((cp = strrchr(argv[0], '/')) != NULL)
-               program_name = cp + 1;
+               ndo->program_name = program_name = cp + 1;
        else
-               program_name = argv[0];
+               ndo->program_name = program_name = argv[0];
+
+#ifdef _WIN32
+       if (pcap_wsockinit() != 0)
+               error("Attempting to initialize Winsock failed");
+#endif /* _WIN32 */
 
        /*
         * On platforms where the CPU doesn't support unaligned loads,
@@ -772,10 +1183,6 @@ main(int argc, char **argv)
        if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
                error("%s", ebuf);
 
-#ifdef USE_LIBSMI
-       smiInit("tcpdump");
-#endif
-
        while (
            (op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1)
                switch (op) {
@@ -792,13 +1199,13 @@ main(int argc, char **argv)
                        ++ndo->ndo_bflag;
                        break;
 
-#if defined(HAVE_PCAP_CREATE) || defined(WIN32)
+#if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
                case 'B':
                        Bflag = atoi(optarg)*1024;
                        if (Bflag <= 0)
                                error("invalid packet buffer size %s", optarg);
                        break;
-#endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
+#endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
 
                case 'c':
                        cnt = atoi(optarg);
@@ -808,7 +1215,7 @@ main(int argc, char **argv)
 
                case 'C':
                        Cflag = atoi(optarg) * 1000000;
-                       if (Cflag < 0)
+                       if (Cflag <= 0)
                                error("invalid file size %s", optarg);
                        break;
 
@@ -860,7 +1267,7 @@ main(int argc, char **argv)
 
                case 'h':
                        print_usage();
-                       exit(0);
+                       exit_tcpdump(0);
                        break;
 
                case 'H':
@@ -868,44 +1275,6 @@ main(int argc, char **argv)
                        break;
 
                case 'i':
-                       if (optarg[0] == '0' && optarg[1] == 0)
-                               error("Invalid adapter index");
-
-#ifdef HAVE_PCAP_FINDALLDEVS
-                       /*
-                        * If the argument is a number, treat it as
-                        * an index into the list of adapters, as
-                        * printed by "tcpdump -D".
-                        *
-                        * This should be OK on UNIX systems, as interfaces
-                        * shouldn't have names that begin with digits.
-                        * It can be useful on Windows, where more than
-                        * one interface can have the same name.
-                        */
-                       devnum = strtol(optarg, &end, 10);
-                       if (optarg != end && *end == '\0') {
-                               if (devnum < 0)
-                                       error("Invalid adapter index");
-
-                               if (pcap_findalldevs(&devpointer, ebuf) < 0)
-                                       error("%s", ebuf);
-                               else {
-                                       /*
-                                        * Look for the devnum-th entry
-                                        * in the list of devices
-                                        * (1-based).
-                                        */
-                                       for (i = 0;
-                                           i < devnum-1 && devpointer != NULL;
-                                           i++, devpointer = devpointer->next)
-                                               ;
-                                       if (devpointer == NULL)
-                                               error("Invalid adapter index");
-                               }
-                               device = devpointer->name;
-                               break;
-                       }
-#endif /* HAVE_PCAP_FINDALLDEVS */
                        device = optarg;
                        break;
 
@@ -928,24 +1297,24 @@ main(int argc, char **argv)
 #endif
 
                case 'l':
-#ifdef WIN32
+#ifdef _WIN32
                        /*
                         * _IOLBF is the same as _IOFBF in Microsoft's C
                         * libraries; the only alternative they offer
                         * is _IONBF.
                         *
                         * XXX - this should really be checking for MSVC++,
-                        * not WIN32, if, for example, MinGW has its own
+                        * not _WIN32, if, for example, MinGW has its own
                         * C library that is more UNIX-compatible.
                         */
                        setvbuf(stdout, NULL, _IONBF, 0);
-#else /* WIN32 */
+#else /* _WIN32 */
 #ifdef HAVE_SETLINEBUF
                        setlinebuf(stdout);
 #else
                        setvbuf(stdout, NULL, _IOLBF, 0);
 #endif
-#endif /* WIN32 */
+#endif /* _WIN32 */
                        break;
 
                case 'K':
@@ -953,16 +1322,14 @@ main(int argc, char **argv)
                        break;
 
                case 'm':
-#ifdef USE_LIBSMI
-                       if (smiLoadModule(optarg) == 0) {
-                               error("could not load MIB module %s", optarg);
+                       if (nd_have_smi_support()) {
+                               if (nd_load_smi_module(optarg, ebuf, sizeof ebuf) == -1)
+                                       error("%s", ebuf);
+                       } else {
+                               (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
+                                             program_name, optarg);
+                               (void)fprintf(stderr, "(no libsmi support)\n");
                        }
-                       ndo->ndo_sflag = 1;
-#else
-                       (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
-                                     program_name, optarg);
-                       (void)fprintf(stderr, "(no libsmi support)\n");
-#endif
                        break;
 
                case 'M':
@@ -1011,10 +1378,6 @@ main(int argc, char **argv)
                        RFileName = optarg;
                        break;
 
-               case 'R':
-                       ndo->ndo_Rflag = 0;
-                       break;
-
                case 's':
                        ndo->ndo_snaplen = strtol(optarg, &end, 0);
                        if (optarg == end || *end != '\0'
@@ -1065,6 +1428,8 @@ main(int argc, char **argv)
                                ndo->ndo_packettype = PT_PGM_ZMTP1;
                        else if (ascii_strcasecmp(optarg, "lmp") == 0)
                                ndo->ndo_packettype = PT_LMP;
+                       else if (ascii_strcasecmp(optarg, "resp") == 0)
+                               ndo->ndo_packettype = PT_RESP;
                        else
                                error("unknown packet type `%s'", optarg);
                        break;
@@ -1093,7 +1458,7 @@ main(int argc, char **argv)
 
                case 'W':
                        Wflag = atoi(optarg);
-                       if (Wflag < 0)
+                       if (Wflag <= 0)
                                error("invalid number of output files %s", optarg);
                        WflagChars = getWflagChars(Wflag);
                        break;
@@ -1109,33 +1474,27 @@ main(int argc, char **argv)
                        break;
 
                case 'y':
-                       ndo->ndo_dltname = optarg;
-                       ndo->ndo_dlt =
-                         pcap_datalink_name_to_val(ndo->ndo_dltname);
-                       if (ndo->ndo_dlt < 0)
-                               error("invalid data link type %s", ndo->ndo_dltname);
+                       yflag_dlt_name = optarg;
+                       yflag_dlt =
+                               pcap_datalink_name_to_val(yflag_dlt_name);
+                       if (yflag_dlt < 0)
+                               error("invalid data link type %s", yflag_dlt_name);
                        break;
 
-#if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
+#ifdef HAVE_PCAP_SET_PARSER_DEBUG
                case 'Y':
                        {
                        /* Undocumented flag */
-#ifdef HAVE_PCAP_DEBUG
-                       extern int pcap_debug;
-                       pcap_debug = 1;
-#else
-                       extern int yydebug;
-                       yydebug = 1;
-#endif
+                       pcap_set_parser_debug(1);
                        }
                        break;
 #endif
                case 'z':
-                       zflag = strdup(optarg);
+                       zflag = optarg;
                        break;
 
                case 'Z':
-                       username = strdup(optarg);
+                       username = optarg;
                        break;
 
                case '#':
@@ -1144,7 +1503,7 @@ main(int argc, char **argv)
 
                case OPTION_VERSION:
                        print_version();
-                       exit(0);
+                       exit_tcpdump(0);
                        break;
 
 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
@@ -1157,13 +1516,13 @@ main(int argc, char **argv)
 
 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
                case OPTION_IMMEDIATE_MODE:
-                       ndo->ndo_immediate = 1;
+                       immediate_mode = 1;
                        break;
 #endif
 
                default:
                        print_usage();
-                       exit(1);
+                       exit_tcpdump(1);
                        /* NOTREACHED */
                }
 
@@ -1204,7 +1563,7 @@ main(int argc, char **argv)
         * probably expecting to see packets pop up immediately.
         */
        if (WFileName == NULL && isatty(1))
-               ndo->ndo_immediate = 1;
+               immediate_mode = 1;
 #endif
 
 #ifdef WITH_CHROOT
@@ -1235,7 +1594,7 @@ main(int argc, char **argv)
                 * In either case, we're reading a savefile, not doing
                 * a live capture.
                 */
-#ifndef WIN32
+#ifndef _WIN32
                /*
                 * We don't need network access, so relinquish any set-UID
                 * or set-GID privileges we have (if any).
@@ -1247,7 +1606,7 @@ main(int argc, char **argv)
                 */
                if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
                        fprintf(stderr, "Warning: setgid/setuid failed !\n");
-#endif /* WIN32 */
+#endif /* _WIN32 */
                if (VFileName != NULL) {
                        if (VFileName[0] == '-' && VFileName[1] == '\0')
                                VFile = stdin;
@@ -1255,7 +1614,7 @@ main(int argc, char **argv)
                                VFile = fopen(VFileName, "r");
 
                        if (VFile == NULL)
-                               error("Unable to open file: %s\n", strerror(errno));
+                               error("Unable to open file: %s\n", pcap_strerror(errno));
 
                        ret = get_next_file(VFile, VFileLine);
                        if (!ret)
@@ -1295,157 +1654,91 @@ main(int argc, char **argv)
                 * We're doing a live capture.
                 */
                if (device == NULL) {
+                       /*
+                        * No interface was specified.  Pick one.
+                        */
+#ifdef HAVE_PCAP_FINDALLDEVS
+                       /*
+                        * Find the list of interfaces, and pick
+                        * the first interface.
+                        */
+                       if (pcap_findalldevs(&devlist, ebuf) >= 0 &&
+                           devlist != NULL) {
+                               device = strdup(devlist->name);
+                               pcap_freealldevs(devlist);
+                       }
+#else /* HAVE_PCAP_FINDALLDEVS */
+                       /*
+                        * Use whatever interface pcap_lookupdev()
+                        * chooses.
+                        */
                        device = pcap_lookupdev(ebuf);
+#endif
                        if (device == NULL)
                                error("%s", ebuf);
                }
-#ifdef WIN32
-               /*
-                * Print a message to the standard error on Windows.
-                * XXX - why do it here, with a different message?
-                */
-               if(strlen(device) == 1) /* we assume that an ASCII string is always longer than 1 char */
-               {                                               /* a Unicode string has a \0 as second byte (so strlen() is 1) */
-                       fprintf(stderr, "%s: listening on %ws\n", program_name, device);
-               }
-               else
-               {
-                       fprintf(stderr, "%s: listening on %s\n", program_name, device);
-               }
-
-               fflush(stderr);
-#endif /* WIN32 */
-#ifdef HAVE_PCAP_CREATE
-               pd = pcap_create(device, ebuf);
-               if (pd == NULL)
-                       error("%s", ebuf);
-#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
-               if (Jflag)
-                       show_tstamp_types_and_exit(device, pd);
-#endif
-#ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
-               status = pcap_set_tstamp_precision(pd, 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));
-#endif
 
-#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
-               if (ndo->ndo_immediate) {
-                       status = pcap_set_immediate_mode(pd, 1);
-                       if (status != 0)
-                               error("%s: Can't set immediate mode: %s",
-                               device,
-                               pcap_statustostr(status));
-               }
-#endif
                /*
-                * Is this an interface that supports monitor mode?
+                * Try to open the interface with the specified name.
                 */
-               if (pcap_can_set_rfmon(pd) == 1)
-                       supports_monitor_mode = 1;
-               else
-                       supports_monitor_mode = 0;
-               status = pcap_set_snaplen(pd, ndo->ndo_snaplen);
-               if (status != 0)
-                       error("%s: Can't set snapshot length: %s",
-                           device, pcap_statustostr(status));
-               status = pcap_set_promisc(pd, !pflag);
-               if (status != 0)
-                       error("%s: Can't set promiscuous mode: %s",
-                           device, pcap_statustostr(status));
-               if (Iflag) {
-                       status = pcap_set_rfmon(pd, 1);
-                       if (status != 0)
-                               error("%s: Can't set monitor mode: %s",
-                                   device, pcap_statustostr(status));
-               }
-               status = pcap_set_timeout(pd, 1000);
-               if (status != 0)
-                       error("%s: pcap_set_timeout failed: %s",
-                           device, pcap_statustostr(status));
-               if (Bflag != 0) {
-                       status = pcap_set_buffer_size(pd, Bflag);
-                       if (status != 0)
-                               error("%s: Can't set buffer size: %s",
-                                   device, pcap_statustostr(status));
-               }
-#ifdef HAVE_PCAP_SET_TSTAMP_TYPE
-                if (jflag != -1) {
-                       status = pcap_set_tstamp_type(pd, jflag);
-                       if (status < 0)
-                               error("%s: Can't set time stamp type: %s",
-                                     device, pcap_statustostr(status));
-               }
-#endif
-               status = pcap_activate(pd);
-               if (status < 0) {
+               pd = open_interface(device, ndo, ebuf);
+               if (pd == NULL) {
                        /*
-                        * pcap_activate() failed.
+                        * That failed.  If we can get a list of
+                        * interfaces, and the interface name
+                        * is purely numeric, try to use it as
+                        * a 1-based index in the list of
+                        * interfaces.
                         */
-                       cp = pcap_geterr(pd);
-                       if (status == PCAP_ERROR)
-                               error("%s", cp);
-                       else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
-                                 status == PCAP_ERROR_PERM_DENIED) &&
-                                *cp != '\0')
-                               error("%s: %s\n(%s)", device,
-                                   pcap_statustostr(status), cp);
-                       else
-                               error("%s: %s", device,
-                                   pcap_statustostr(status));
-               } else if (status > 0) {
+#ifdef HAVE_PCAP_FINDALLDEVS
+                       devnum = parse_interface_number(device);
+                       if (devnum == -1) {
+                               /*
+                                * It's not a number; just report
+                                * the open error and fail.
+                                */
+                               error("%s", ebuf);
+                       }
+
                        /*
-                        * pcap_activate() succeeded, but it's warning us
-                        * of a problem it had.
+                        * OK, it's a number; try to find the
+                        * interface with that index, and try
+                        * to open it.
+                        *
+                        * find_interface_by_number() exits if it
+                        * couldn't be found.
+                        */
+                       device = find_interface_by_number(devnum);
+                       pd = open_interface(device, ndo, ebuf);
+                       if (pd == NULL)
+                               error("%s", ebuf);
+#else /* HAVE_PCAP_FINDALLDEVS */
+                       /*
+                        * We can't get a list of interfaces; just
+                        * fail.
                         */
-                       cp = pcap_geterr(pd);
-                       if (status == PCAP_WARNING)
-                               warning("%s", cp);
-                       else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
-                                *cp != '\0')
-                               warning("%s: %s\n(%s)", device,
-                                   pcap_statustostr(status), cp);
-                       else
-                               warning("%s: %s", device,
-                                   pcap_statustostr(status));
-               }
-#ifdef HAVE_PCAP_SETDIRECTION
-               if (Qflag != -1) {
-                       status = pcap_setdirection(pd, Qflag);
-                       if (status != 0)
-                               error("%s: pcap_setdirection() failed: %s",
-                                     device,  pcap_geterr(pd));
-               }
-#endif /* HAVE_PCAP_SETDIRECTION */
-#else
-               *ebuf = '\0';
-               pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
-               if (pd == NULL)
                        error("%s", ebuf);
-               else if (*ebuf)
-                       warning("%s", ebuf);
-#endif /* HAVE_PCAP_CREATE */
+#endif /* HAVE_PCAP_FINDALLDEVS */
+               }
+
                /*
                 * Let user own process after socket has been opened.
                 */
-#ifndef WIN32
+#ifndef _WIN32
                if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
                        fprintf(stderr, "Warning: setgid/setuid failed !\n");
-#endif /* WIN32 */
-#if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
+#endif /* _WIN32 */
+#if !defined(HAVE_PCAP_CREATE) && defined(_WIN32)
                if(Bflag != 0)
                        if(pcap_setbuff(pd, Bflag)==-1){
                                error("%s", pcap_geterr(pd));
                        }
-#endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
+#endif /* !defined(HAVE_PCAP_CREATE) && defined(_WIN32) */
                if (Lflag)
-                       show_dlts_and_exit(device, pd);
-               if (ndo->ndo_dlt >= 0) {
+                       show_dlts_and_exit(pd, device);
+               if (yflag_dlt >= 0) {
 #ifdef HAVE_PCAP_SET_DATALINK
-                       if (pcap_set_datalink(pd, ndo->ndo_dlt) < 0)
+                       if (pcap_set_datalink(pd, yflag_dlt) < 0)
                                error("%s", pcap_geterr(pd));
 #else
                        /*
@@ -1453,13 +1746,13 @@ main(int argc, char **argv)
                         * data link type, so we only let them
                         * set it to what it already is.
                         */
-                       if (ndo->ndo_dlt != pcap_datalink(pd)) {
+                       if (yflag_dlt != pcap_datalink(pd)) {
                                error("%s is not one of the DLTs supported by this device\n",
-                                     ndo->ndo_dltname);
+                                     yflag_dlt_name);
                        }
 #endif
                        (void)fprintf(stderr, "%s: data link type %s\n",
-                                     program_name, ndo->ndo_dltname);
+                                     program_name, yflag_dlt_name);
                        (void)fflush(stderr);
                }
                i = pcap_snapshot(pd);
@@ -1479,31 +1772,35 @@ main(int argc, char **argv)
        else
                cmdbuf = copy_argv(&argv[optind]);
 
+#ifdef HAVE_PCAP_SET_OPTIMIZER_DEBUG
+       pcap_set_optimizer_debug(dflag);
+#endif
        if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
                error("%s", pcap_geterr(pd));
        if (dflag) {
                bpf_dump(&fcode, dflag);
                pcap_close(pd);
                free(cmdbuf);
-               exit(0);
+               pcap_freecode(&fcode);
+               exit_tcpdump(0);
        }
        init_print(ndo, localnet, netmask, timezone_offset);
 
-#ifndef WIN32
+#ifndef _WIN32
        (void)setsignal(SIGPIPE, cleanup);
        (void)setsignal(SIGTERM, cleanup);
        (void)setsignal(SIGINT, cleanup);
-#endif /* WIN32 */
+#endif /* _WIN32 */
 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
        (void)setsignal(SIGCHLD, child_cleanup);
 #endif
        /* Cooperate with nohup(1) */
-#ifndef WIN32
+#ifndef _WIN32
        if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
                (void)setsignal(SIGHUP, oldhandler);
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
-#ifndef WIN32
+#ifndef _WIN32
        /*
         * If a user name was specified with "-Z", attempt to switch to
         * that user's UID.  This would probably be used with sudo,
@@ -1534,6 +1831,13 @@ main(int argc, char **argv)
                                CAP_SETGID,
                                -1);
                }
+               if (chroot_dir) {
+                       capng_update(
+                               CAPNG_ADD,
+                               CAPNG_PERMITTED | CAPNG_EFFECTIVE,
+                               CAP_SYS_CHROOT
+                               );
+               }
 
                if (WFileName) {
                        capng_update(
@@ -1548,15 +1852,20 @@ main(int argc, char **argv)
                        droproot(username, chroot_dir);
 
        }
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
        if (pcap_setfilter(pd, &fcode) < 0)
                error("%s", pcap_geterr(pd));
 #ifdef HAVE_CAPSICUM
        if (RFileName == NULL && VFileName == NULL) {
-               static const unsigned long cmds[] = { BIOCGSTATS };
+               static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
 
-               cap_rights_init(&rights, CAP_IOCTL, CAP_READ);
+               /*
+                * The various libpcap devices use a combination of
+                * read (bpf), ioctl (bpf, netmap), poll (netmap)
+                * so we add the relevant access rights.
+                */
+               cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
                if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
                    errno != ENOSYS) {
                        error("unable to limit pcap descriptor");
@@ -1603,6 +1912,10 @@ main(int argc, char **argv)
                if (Cflag != 0 || Gflag != 0) {
 #ifdef HAVE_CAPSICUM
                        dumpinfo.WFileName = strdup(basename(WFileName));
+                       if (dumpinfo.WFileName == NULL) {
+                               error("Unable to allocate memory for file %s",
+                                   WFileName);
+                       }
                        dumpinfo.dirfd = open(dirname(WFileName),
                            O_DIRECTORY | O_RDONLY);
                        if (dumpinfo.dirfd < 0) {
@@ -1635,10 +1948,10 @@ main(int argc, char **argv)
                        pcap_dump_flush(p);
 #endif
        } else {
-               type = pcap_datalink(pd);
-               printinfo = get_print_info(ndo, type);
+               dlt = pcap_datalink(pd);
+               ndo->ndo_if_printer = get_if_printer(ndo, dlt);
                callback = print_packet;
-               pcap_userdata = (u_char *)&printinfo;
+               pcap_userdata = (u_char *)ndo;
        }
 
 #ifdef SIGNAL_REQ_INFO
@@ -1653,7 +1966,7 @@ main(int argc, char **argv)
        if (ndo->ndo_vflag > 0 && WFileName) {
                /*
                 * When capturing to a file, "-v" means tcpdump should,
-                * every 10 secodns, "v"erbosely report the number of
+                * every 10 seconds, "v"erbosely report the number of
                 * packets captured.
                 */
 #ifdef USE_WIN32_MM_TIMER
@@ -1666,7 +1979,6 @@ main(int argc, char **argv)
 #endif
        }
 
-#ifndef WIN32
        if (RFileName == NULL) {
                /*
                 * Live capture (if -V was specified, we set RFileName
@@ -1691,7 +2003,6 @@ main(int argc, char **argv)
                }
                (void)fflush(stderr);
        }
-#endif /* WIN32 */
 
 #ifdef HAVE_CAPSICUM
        cansandbox = (ndo->ndo_nflag && VFileName == NULL && zflag == NULL);
@@ -1742,6 +2053,8 @@ main(int argc, char **argv)
                if (VFileName != NULL) {
                        ret = get_next_file(VFile, VFileLine);
                        if (ret) {
+                               int new_dlt;
+
                                RFileName = VFileLine;
                                pd = pcap_open_offline(RFileName, ebuf);
                                if (pd == NULL)
@@ -1754,30 +2067,67 @@ main(int argc, char **argv)
                                }
 #endif
                                new_dlt = pcap_datalink(pd);
-                               if (WFileName && new_dlt != dlt)
-                                       error("%s: new dlt does not match original", RFileName);
-                               printinfo = get_print_info(ndo, new_dlt);
-                               dlt_name = pcap_datalink_val_to_name(new_dlt);
+                               if (new_dlt != dlt) {
+                                       /*
+                                        * The new file has a different
+                                        * link-layer header type from the
+                                        * previous one.
+                                        */
+                                       if (WFileName != NULL) {
+                                               /*
+                                                * We're writing raw packets
+                                                * that match the filter to
+                                                * a pcap file.  pcap files
+                                                * don't support multiple
+                                                * different link-layer
+                                                * header types, so we fail
+                                                * here.
+                                                */
+                                               error("%s: new dlt does not match original", RFileName);
+                                       }
+
+                                       /*
+                                        * We're printing the decoded packets;
+                                        * switch to the new DLT.
+                                        *
+                                        * To do that, we need to change
+                                        * the printer, change the DLT name,
+                                        * and recompile the filter with
+                                        * the new DLT.
+                                        */
+                                       dlt = new_dlt;
+                                       ndo->ndo_if_printer = get_if_printer(ndo, dlt);
+                                       if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
+                                               error("%s", pcap_geterr(pd));
+                               }
+
+                               /*
+                                * Set the filter on the new file.
+                                */
+                               if (pcap_setfilter(pd, &fcode) < 0)
+                                       error("%s", pcap_geterr(pd));
+
+                               /*
+                                * Report the new file.
+                                */
+                               dlt_name = pcap_datalink_val_to_name(dlt);
                                if (dlt_name == NULL) {
                                        fprintf(stderr, "reading from file %s, link-type %u\n",
-                                       RFileName, new_dlt);
+                                           RFileName, dlt);
                                } else {
                                        fprintf(stderr,
                                        "reading from file %s, link-type %s (%s)\n",
-                                       RFileName, dlt_name,
-                                       pcap_datalink_val_to_description(new_dlt));
+                                           RFileName, dlt_name,
+                                           pcap_datalink_val_to_description(dlt));
                                }
-                               if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
-                                       error("%s", pcap_geterr(pd));
-                               if (pcap_setfilter(pd, &fcode) < 0)
-                                       error("%s", pcap_geterr(pd));
                        }
                }
        }
        while (ret != NULL);
 
        free(cmdbuf);
-       exit(status == -1 ? 1 : 0);
+       pcap_freecode(&fcode);
+       exit_tcpdump(status == -1 ? 1 : 0);
 }
 
 /* make a clean exit on interrupts */
@@ -1817,7 +2167,7 @@ cleanup(int signo _U_)
                (void)fflush(stdout);
                info(1);
        }
-       exit(0);
+       exit_tcpdump(0);
 #endif
 }
 
@@ -1836,14 +2186,14 @@ child_cleanup(int signo _U_)
 static void
 info(register int verbose)
 {
-       struct pcap_stat stat;
+       struct pcap_stat stats;
 
        /*
         * Older versions of libpcap didn't set ps_ifdrop on some
         * platforms; initialize it to 0 to handle that.
         */
-       stat.ps_ifdrop = 0;
-       if (pcap_stats(pd, &stat) < 0) {
+       stats.ps_ifdrop = 0;
+       if (pcap_stats(pd, &stats) < 0) {
                (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
                infoprint = 0;
                return;
@@ -1858,38 +2208,52 @@ info(register int verbose)
                fputs(", ", stderr);
        else
                putc('\n', stderr);
-       (void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
-           PLURAL_SUFFIX(stat.ps_recv));
+       (void)fprintf(stderr, "%u packet%s received by filter", stats.ps_recv,
+           PLURAL_SUFFIX(stats.ps_recv));
        if (!verbose)
                fputs(", ", stderr);
        else
                putc('\n', stderr);
-       (void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
-           PLURAL_SUFFIX(stat.ps_drop));
-       if (stat.ps_ifdrop != 0) {
+       (void)fprintf(stderr, "%u packet%s dropped by kernel", stats.ps_drop,
+           PLURAL_SUFFIX(stats.ps_drop));
+       if (stats.ps_ifdrop != 0) {
                if (!verbose)
                        fputs(", ", stderr);
                else
                        putc('\n', stderr);
                (void)fprintf(stderr, "%u packet%s dropped by interface\n",
-                   stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
+                   stats.ps_ifdrop, PLURAL_SUFFIX(stats.ps_ifdrop));
        } else
                putc('\n', stderr);
        infoprint = 0;
 }
 
 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
+#ifdef HAVE_FORK
+#define fork_subprocess() fork()
+#else
+#define fork_subprocess() vfork()
+#endif
 static void
 compress_savefile(const char *filename)
 {
-# ifdef HAVE_FORK
-       if (fork())
-# else
-       if (vfork())
-# endif
+       pid_t child;
+
+       child = fork_subprocess();
+       if (child == -1) {
+               fprintf(stderr,
+                       "compress_savefile: fork failed: %s\n",
+                       pcap_strerror(errno));
                return;
+       }
+       if (child != 0) {
+               /* Parent process. */
+               return;
+       }
+
        /*
-        * Set to lowest priority so that this doesn't disturb the capture
+        * Child process.
+        * Set to lowest priority so that this doesn't disturb the capture.
         */
 #ifdef NZERO
        setpriority(PRIO_PROCESS, 0, NZERO - 1);
@@ -1898,15 +2262,15 @@ compress_savefile(const char *filename)
 #endif
        if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
                fprintf(stderr,
-                       "compress_savefile:execlp(%s, %s): %s\n",
+                       "compress_savefile: execlp(%s, %s) failed: %s\n",
                        zflag,
                        filename,
-                       strerror(errno));
-# ifdef HAVE_FORK
+                       pcap_strerror(errno));
+#ifdef HAVE_FORK
        exit(1);
-# else
+#else
        _exit(1);
-# endif
+#endif
 }
 #else  /* HAVE_FORK && HAVE_VFORK */
 static void
@@ -1976,7 +2340,8 @@ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *s
                        if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
                                (void)fprintf(stderr, "Maximum file limit reached: %d\n",
                                    Wflag);
-                               exit(0);
+                               info(1);
+                               exit_tcpdump(0);
                                /* NOTREACHED */
                        }
                        if (dump_info->CurrentFileName != NULL)
@@ -2139,22 +2504,18 @@ dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 static void
 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 {
-       struct print_info *print_info;
-
        ++packets_captured;
 
        ++infodelay;
 
-       print_info = (struct print_info *)user;
-
-       pretty_print_packet(print_info, h, sp, packets_captured);
+       pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
 
        --infodelay;
        if (infoprint)
                info(0);
 }
 
-#ifdef WIN32
+#ifdef _WIN32
        /*
         * XXX - there should really be libpcap calls to get the version
         * number as a string (the string would be generated from #defines
@@ -2198,17 +2559,13 @@ RETSIGTYPE requestinfo(int signo _U_)
 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
                                  DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
 {
-       struct pcap_stat stat;
-
-       if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
+       if (infodelay == 0)
                fprintf(stderr, "Got %u\r", packets_captured);
 }
 #elif defined(HAVE_ALARM)
 static void verbose_stats_dump(int sig _U_)
 {
-       struct pcap_stat stat;
-
-       if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
+       if (infodelay == 0)
                fprintf(stderr, "Got %u\r", packets_captured);
        alarm(1);
 }
@@ -2220,37 +2577,46 @@ print_version(void)
 {
        extern char version[];
 #ifndef HAVE_PCAP_LIB_VERSION
-#if defined(WIN32) || defined(HAVE_PCAP_VERSION)
+#if defined(_WIN32) || defined(HAVE_PCAP_VERSION)
        extern char pcap_version[];
-#else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
+#else /* defined(_WIN32) || defined(HAVE_PCAP_VERSION) */
        static char pcap_version[] = "unknown";
-#endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
+#endif /* defined(_WIN32) || defined(HAVE_PCAP_VERSION) */
 #endif /* HAVE_PCAP_LIB_VERSION */
+       const char *smi_version_string;
 
 #ifdef HAVE_PCAP_LIB_VERSION
-#ifdef WIN32
+#ifdef _WIN32
        (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
-#else /* WIN32 */
+#else /* _WIN32 */
        (void)fprintf(stderr, "%s version %s\n", program_name, version);
-#endif /* WIN32 */
+#endif /* _WIN32 */
        (void)fprintf(stderr, "%s\n",pcap_lib_version());
 #else /* HAVE_PCAP_LIB_VERSION */
-#ifdef WIN32
+#ifdef _WIN32
        (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
        (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
-#else /* WIN32 */
+#else /* _WIN32 */
        (void)fprintf(stderr, "%s version %s\n", program_name, version);
        (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
-#endif /* WIN32 */
+#endif /* _WIN32 */
 #endif /* HAVE_PCAP_LIB_VERSION */
 
 #if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION)
        (void)fprintf (stderr, "%s\n", SSLeay_version(SSLEAY_VERSION));
 #endif
 
-#ifdef USE_LIBSMI
-       (void)fprintf (stderr, "SMI-library: %s\n", smi_version_string);
-#endif
+       smi_version_string = nd_smi_version_string();
+       if (smi_version_string != NULL)
+               (void)fprintf (stderr, "SMI-library: %s\n", smi_version_string);
+
+#if defined(__SANITIZE_ADDRESS__)
+       (void)fprintf (stderr, "Compiled with AddressSanitizer/GCC.\n");
+#elif defined(__has_feature)
+#  if __has_feature(address_sanitizer)
+       (void)fprintf (stderr, "Compiled with AddressSanitizer/CLang.\n");
+#  endif
+#endif /* __SANITIZE_ADDRESS__ or __has_feature */
 }
 USES_APPLE_RST
 
@@ -2259,7 +2625,7 @@ print_usage(void)
 {
        print_version();
        (void)fprintf(stderr,
-"Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ]\n", program_name);
+"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,
 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
        (void)fprintf(stderr,
@@ -2280,7 +2646,7 @@ print_usage(void)
 #endif
        (void)fprintf(stderr, "[ -T type ] [ --version ] [ -V file ]\n");
        (void)fprintf(stderr,
-"\t\t[ -w file ] [ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
+"\t\t[ -w file ] [ -W filecount ] [ -y datalinktype ] [ -z postrotate-command ]\n");
        (void)fprintf(stderr,
 "\t\t[ -Z user ] [ expression ]\n");
 }