]> The Tcpdump Group git mirrors - tcpdump/blobdiff - tcpdump.c
tcpdump: plug a memory leak.
[tcpdump] / tcpdump.c
index 95162ecc18165f9a4518354684698e783b94ebfd..7538a49c3ca2944ccfcdaf9aa32fe221622a8946 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 void (*setsignal (int sig, void (*func)(int)))(int);
 static void cleanup(int);
@@ -691,6 +691,7 @@ show_remote_devices_and_exit(void)
 #define OPTION_TSTAMP_NANO             134
 #define OPTION_FP_TYPE                 135
 #define OPTION_COUNT                   136
+#define OPTION_PRINT_SAMPLING          137
 
 static const struct option longopts[] = {
 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
@@ -738,6 +739,7 @@ static const struct option longopts[] = {
        { "fp-type", no_argument, NULL, OPTION_FP_TYPE },
        { "number", no_argument, NULL, '#' },
        { "print", no_argument, NULL, OPTION_PRINT },
+       { "print-sampling", required_argument, NULL, OPTION_PRINT_SAMPLING },
        { "version", no_argument, NULL, OPTION_VERSION },
        { NULL, 0, NULL, 0 }
 };
@@ -795,7 +797,7 @@ droproot(const char *username, const char *chroot_dir)
                error("Couldn't find user '%.32s'", username);
 #ifdef HAVE_LIBCAP_NG
        /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */
-DIAG_OFF_CLANG(assign-enum)
+DIAG_OFF_ASSIGN_ENUM
        capng_updatev(
                CAPNG_DROP,
                CAPNG_EFFECTIVE | CAPNG_PERMITTED,
@@ -803,7 +805,7 @@ 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 */
 
@@ -831,6 +833,8 @@ MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
         char *filename = malloc(PATH_MAX + 1);
         if (filename == NULL)
             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) {
@@ -842,9 +846,25 @@ MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
           }
 
           /* 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);
         }
@@ -1864,6 +1884,8 @@ main(int argc, char **argv)
                                ndo->ndo_packettype = PT_SOMEIP;
                        else if (ascii_strcasecmp(optarg, "domain") == 0)
                                ndo->ndo_packettype = PT_DOMAIN;
+                       else if (ascii_strcasecmp(optarg, "quic") == 0)
+                               ndo->ndo_packettype = PT_QUIC;
                        else
                                error("unknown packet type `%s'", optarg);
                        break;
@@ -1958,6 +1980,14 @@ main(int argc, char **argv)
                        print = 1;
                        break;
 
+               case OPTION_PRINT_SAMPLING:
+                       print = 1;
+                       ++ndo->ndo_Sflag;
+                       ndo->ndo_print_sampling = atoi(optarg);
+                       if (ndo->ndo_print_sampling <= 0)
+                               error("invalid print sampling %s", optarg);
+                       break;
+
 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
                case OPTION_TSTAMP_MICRO:
                        ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
@@ -2337,33 +2367,33 @@ 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 */
@@ -2429,17 +2459,44 @@ 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 &&
@@ -2654,6 +2711,8 @@ 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));
                                }
@@ -2688,7 +2747,7 @@ DIAG_ON_CLANG(assign-enum)
 
        free(cmdbuf);
        pcap_freecode(&fcode);
-       exit_tcpdump(status == -1 ? 1 : 0);
+       exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS);
 }
 
 /*
@@ -2704,7 +2763,14 @@ 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);
@@ -3174,7 +3240,7 @@ static void verbose_stats_dump(int sig _U_)
 }
 #endif /* _WIN32 */
 
-USES_APPLE_DEPRECATED_API
+DIAG_OFF_DEPRECATION
 static void
 print_version(FILE *f)
 {
@@ -3212,7 +3278,7 @@ print_version(FILE *f)
 #  endif
 #endif /* __SANITIZE_ADDRESS__ or __has_feature */
 }
-USES_APPLE_RST
+DIAG_ON_DEPRECATION
 
 static void
 print_usage(FILE *f)
@@ -3233,9 +3299,11 @@ print_usage(FILE *f)
 "\t\t" m_FLAG_USAGE "\n");
 #endif
        (void)fprintf(f,
-"\t\t[ -M secret ] [ --number ] [ --print ]" Q_FLAG_USAGE "\n");
+"\t\t[ -M secret ] [ --number ] [ --print ]\n");
+       (void)fprintf(f,
+"\t\t[ --print-sampling nth ]" Q_FLAG_USAGE " [ -r file ]\n");
        (void)fprintf(f,
-"\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ --version ]\n");
+"\t\t[ -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