]> The Tcpdump Group git mirrors - tcpdump/blobdiff - tcpdump.c
IP: Enable TSO (TCP Segmentation Offload) support
[tcpdump] / tcpdump.c
index 16b7962bfc797e0ec457b53f0784297b813e34dd..e8c6b816281b63df089014c67f62af51ba097355 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -78,7 +78,9 @@ The Regents of the University of California.  All rights reserved.\n";
 #endif
 /* Capsicum-specific code requires macros from <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/capsicum.h>
@@ -161,6 +163,8 @@ The Regents of the University of California.  All rights reserved.\n";
 
 #include "print.h"
 
+#include "diag-control.h"
+
 #include "fptype.h"
 
 #ifndef PATH_MAX
@@ -238,10 +242,6 @@ static int infoprint;
 
 char *program_name;
 
-#ifdef HAVE_CASPER
-cap_channel_t *capdns;
-#endif
-
 /* Forwards */
 static NORETURN void error(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
 static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
@@ -433,15 +433,15 @@ show_tstamp_types_and_exit(pcap_t *pc, const char *device)
                    device);
                exit_tcpdump(S_SUCCESS);
        }
-       fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
+       fprintf(stdout, "Time stamp types for %s (use option -j to set):\n",
            device);
        for (i = 0; i < n_tstamp_types; i++) {
                tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
                if (tstamp_type_name != NULL) {
-                       (void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
+                       (void) fprintf(stdout, "  %s (%s)\n", tstamp_type_name,
                            pcap_tstamp_type_val_to_description(tstamp_types[i]));
                } else {
-                       (void) fprintf(stderr, "  %d\n", tstamp_types[i]);
+                       (void) fprintf(stdout, "  %d\n", tstamp_types[i]);
                }
        }
        pcap_free_tstamp_types(tstamp_types);
@@ -470,28 +470,30 @@ show_dlts_and_exit(pcap_t *pc, const char *device)
         * monitor mode might be different from the ones available when
         * not in monitor mode).
         */
+       (void) fprintf(stdout, "Data link types for ");
        if (supports_monitor_mode)
-               (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
+               (void) fprintf(stdout, "%s %s",
                    device,
                    Iflag ? "when in monitor mode" : "when not in monitor mode");
        else
-               (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
+               (void) fprintf(stdout, "%s",
                    device);
+       (void) fprintf(stdout, " (use option -y to set):\n");
 
        for (i = 0; i < n_dlts; i++) {
                dlt_name = pcap_datalink_val_to_name(dlts[i]);
                if (dlt_name != NULL) {
-                       (void) fprintf(stderr, "  %s (%s)", dlt_name,
+                       (void) fprintf(stdout, "  %s (%s)", dlt_name,
                            pcap_datalink_val_to_description(dlts[i]));
 
                        /*
                         * OK, does tcpdump handle that type?
                         */
                        if (!has_printer(dlts[i]))
-                               (void) fprintf(stderr, " (printing not supported)");
-                       fprintf(stderr, "\n");
+                               (void) fprintf(stdout, " (printing not supported)");
+                       fprintf(stdout, "\n");
                } else {
-                       (void) fprintf(stderr, "  DLT %d (printing not supported)\n",
+                       (void) fprintf(stdout, "  DLT %d (printing not supported)\n",
                            dlts[i]);
                }
        }
@@ -806,8 +808,8 @@ droproot(const char *username, const char *chroot_dir)
        } else
                error("Couldn't find user '%.32s'", username);
 #ifdef HAVE_LIBCAP_NG
-       /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */
-DIAG_OFF_CLANG(assign-enum)
+       /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT anymore. */
+DIAG_OFF_ASSIGN_ENUM
        capng_updatev(
                CAPNG_DROP,
                CAPNG_EFFECTIVE | CAPNG_PERMITTED,
@@ -815,7 +817,7 @@ DIAG_OFF_CLANG(assign-enum)
                CAP_SETGID,
                CAP_SYS_CHROOT,
                -1);
-DIAG_ON_CLANG(assign-enum)
+DIAG_ON_ASSIGN_ENUM
        capng_apply(CAPNG_SELECT_BOTH);
 #endif /* HAVE_LIBCAP_NG */
 
@@ -842,7 +844,9 @@ 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) {
@@ -850,13 +854,29 @@ 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);
         }
@@ -959,7 +979,7 @@ tstamp_precision_to_string(int precision)
  * along the lines of ioctl(), the fact that ioctl() operations are
  * largely specific to particular character devices but fcntl() operations
  * are either generic to all descriptors or generic to all descriptors for
- * regular files nonwithstanding.
+ * regular files notwithstanding.
  *
  * The Capsicum people decided that fine-grained control of descriptor
  * operations was required, so that you need to grant permission for
@@ -1036,7 +1056,7 @@ copy_argv(char **argv)
 
        buf = (char *)malloc(len);
        if (buf == NULL)
-               error("copy_argv: malloc");
+               error("%s: malloc", __func__);
 
        p = argv;
        dst = buf;
@@ -1641,8 +1661,8 @@ 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;
 
@@ -1951,14 +1971,6 @@ main(int argc, char **argv)
                show_remote_devices_and_exit();
 #endif
 
-#if defined(DLT_LINUX_SLL2) && defined(HAVE_PCAP_SET_DATALINK)
-/* Set default linktype DLT_LINUX_SLL2 when capturing on the "any" device */
-               if (device != NULL &&
-                   strncmp (device, "any", strlen("any")) == 0
-                   && yflag_dlt == -1)
-                       yflag_dlt = DLT_LINUX_SLL2;
-#endif
-
        switch (ndo->ndo_tflag) {
 
        case 0: /* Default */
@@ -2008,6 +2020,8 @@ main(int argc, char **argv)
                /* Run with '-Z root' to restore old behaviour */
                if (!username)
                        username = WITH_USER;
+               else if (strcmp(username, "root") == 0)
+                       username = NULL;
        }
 #endif
 
@@ -2211,6 +2225,21 @@ main(int argc, char **argv)
                                      pcap_datalink_val_to_name(yflag_dlt));
                        (void)fflush(stderr);
                }
+#if defined(DLT_LINUX_SLL2) && defined(HAVE_PCAP_SET_DATALINK)
+               else {
+                       /*
+                        * Attempt to set default linktype to
+                        * DLT_LINUX_SLL2 when capturing on the
+                        * "any" device.
+                        *
+                        * If the attempt fails, just quietly drive
+                        * on; this may be a non-Linux "any" device
+                        * that doesn't support DLT_LINUX_SLL2.
+                        */
+                       if (strcmp(device, "any") == 0)
+                               (void) pcap_set_datalink(pd, DLT_LINUX_SLL2);
+               }
+#endif
                i = pcap_snapshot(pd);
                if (ndo->ndo_snaplen < i) {
                        if (ndo->ndo_snaplen != 0)
@@ -2290,33 +2319,33 @@ main(int argc, char **argv)
                /* Initialize capng */
                capng_clear(CAPNG_SELECT_BOTH);
                if (username) {
-DIAG_OFF_CLANG(assign-enum)
+DIAG_OFF_ASSIGN_ENUM
                        capng_updatev(
                                CAPNG_ADD,
                                CAPNG_PERMITTED | CAPNG_EFFECTIVE,
                                CAP_SETUID,
                                CAP_SETGID,
                                -1);
-DIAG_ON_CLANG(assign-enum)
+DIAG_ON_ASSIGN_ENUM
                }
                if (chroot_dir) {
-DIAG_OFF_CLANG(assign-enum)
+DIAG_OFF_ASSIGN_ENUM
                        capng_update(
                                CAPNG_ADD,
                                CAPNG_PERMITTED | CAPNG_EFFECTIVE,
                                CAP_SYS_CHROOT
                                );
-DIAG_ON_CLANG(assign-enum)
+DIAG_ON_ASSIGN_ENUM
                }
 
                if (WFileName) {
-DIAG_OFF_CLANG(assign-enum)
+DIAG_OFF_ASSIGN_ENUM
                        capng_update(
                                CAPNG_ADD,
                                CAPNG_PERMITTED | CAPNG_EFFECTIVE,
                                CAP_DAC_OVERRIDE
                                );
-DIAG_ON_CLANG(assign-enum)
+DIAG_ON_ASSIGN_ENUM
                }
                capng_apply(CAPNG_SELECT_BOTH);
 #endif /* HAVE_LIBCAP_NG */
@@ -2382,17 +2411,44 @@ DIAG_ON_CLANG(assign-enum)
 #endif
                if (Cflag != 0 || Gflag != 0) {
 #ifdef HAVE_CAPSICUM
-                       dumpinfo.WFileName = strdup(basename(WFileName));
+                       /*
+                        * basename() and dirname() may modify their input buffer
+                        * and they do since FreeBSD 12.0, but they didn't before.
+                        * Hence use the return value only, but always assume the
+                        * input buffer has been modified and would need to be
+                        * reset before the next use.
+                        */
+                       char *WFileName_copy;
+
+                       if ((WFileName_copy = strdup(WFileName)) == NULL) {
+                               error("Unable to allocate memory for file %s",
+                                   WFileName);
+                       }
+                       DIAG_OFF_C11_EXTENSIONS
+                       dumpinfo.WFileName = strdup(basename(WFileName_copy));
+                       DIAG_ON_C11_EXTENSIONS
                        if (dumpinfo.WFileName == NULL) {
                                error("Unable to allocate memory for file %s",
                                    WFileName);
                        }
-                       dumpinfo.dirfd = open(dirname(WFileName),
+                       free(WFileName_copy);
+
+                       if ((WFileName_copy = strdup(WFileName)) == NULL) {
+                               error("Unable to allocate memory for file %s",
+                                   WFileName);
+                       }
+                       DIAG_OFF_C11_EXTENSIONS
+                       char *WFileName_dirname = dirname(WFileName_copy);
+                       DIAG_ON_C11_EXTENSIONS
+                       dumpinfo.dirfd = open(WFileName_dirname,
                            O_DIRECTORY | O_RDONLY);
                        if (dumpinfo.dirfd < 0) {
                                error("unable to open directory %s",
-                                   dirname(WFileName));
+                                   WFileName_dirname);
                        }
+                       free(WFileName_dirname);
+                       free(WFileName_copy);
+
                        cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
                            CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
                        if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
@@ -2516,6 +2572,9 @@ DIAG_ON_CLANG(assign-enum)
 #else
        cansandbox = (cansandbox && ndo->ndo_nflag);
 #endif /* HAVE_CASPER */
+       cansandbox = (cansandbox && (pcap_fileno(pd) != -1 ||
+           RFileName != NULL));
+
        if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
                error("unable to enter the capability mode");
 #endif /* HAVE_CAPSICUM */
@@ -2607,6 +2666,8 @@ DIAG_ON_CLANG(assign-enum)
                                         */
                                        dlt = new_dlt;
                                        ndo->ndo_if_printer = get_if_printer(dlt);
+                                       /* Free the old filter */
+                                       pcap_freecode(&fcode);
                                        if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
                                                error("%s", pcap_geterr(pd));
                                }
@@ -2636,12 +2697,12 @@ DIAG_ON_CLANG(assign-enum)
        while (ret != NULL);
 
        if (count_mode && RFileName != NULL)
-               fprintf(stderr, "%u packet%s\n", packets_captured,
+               fprintf(stdout, "%u packet%s\n", packets_captured,
                        PLURAL_SUFFIX(packets_captured));
 
        free(cmdbuf);
        pcap_freecode(&fcode);
-       exit_tcpdump(status == -1 ? 1 : 0);
+       exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS);
 }
 
 /*
@@ -2657,7 +2718,14 @@ static void
 
        memset(&new, 0, sizeof(new));
        new.sa_handler = func;
-       if (sig == SIGCHLD)
+       if ((sig == SIGCHLD)
+# ifdef SIGNAL_REQ_INFO
+               || (sig == SIGNAL_REQ_INFO)
+# endif
+# ifdef SIGNAL_FLUSH_PCAP
+               || (sig == SIGNAL_FLUSH_PCAP)
+# endif
+               )
                new.sa_flags = SA_RESTART;
        if (sigaction(sig, &new, &old) < 0)
                return (SIG_ERR);
@@ -2722,7 +2790,7 @@ cleanup(int signo _U_)
 static void
 child_cleanup(int signo _U_)
 {
-  wait(NULL);
+  while (waitpid(-1, NULL, WNOHANG) >= 0);
 }
 #endif /* HAVE_FORK && HAVE_VFORK */
 
@@ -2849,8 +2917,8 @@ 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));
                }
 
 
@@ -2991,7 +3059,7 @@ 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);
@@ -3127,7 +3195,7 @@ static void verbose_stats_dump(int sig _U_)
 }
 #endif /* _WIN32 */
 
-USES_APPLE_DEPRECATED_API
+DIAG_OFF_DEPRECATION
 static void
 print_version(FILE *f)
 {
@@ -3165,7 +3233,7 @@ print_version(FILE *f)
 #  endif
 #endif /* __SANITIZE_ADDRESS__ or __has_feature */
 }
-USES_APPLE_RST
+DIAG_ON_DEPRECATION
 
 static void
 print_usage(FILE *f)