C compilers can, and some do, optimize away pointer underflow checks.

[tcpdump] / tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index a347bc2cc87ffaacdbf5847f3f92714f1c938956..88295d84c69e94efc64f8f9cab1f562e71d03fbf 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -1244,8 +1244,10 @@ main(int argc, char **argv)
        (void)setsignal(SIGPIPE, cleanup);
        (void)setsignal(SIGTERM, cleanup);
        (void)setsignal(SIGINT, cleanup);
-       (void)setsignal(SIGCHLD, child_cleanup);
 #endif /* WIN32 */
+#if defined(HAVE_FORK) || defined(HAVE_VFORK)
+       (void)setsignal(SIGCHLD, child_cleanup);
+#endif
        /* Cooperate with nohup(1) */
 #ifndef WIN32  
        if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
@@ -1458,13 +1460,13 @@ cleanup(int signo _U_)
   On windows, we do not use a fork, so we do not care less about
   waiting a child processes to die
  */
-#ifndef WIN32
+#if defined(HAVE_FORK) || defined(HAVE_VFORK)
 static RETSIGTYPE
 child_cleanup(int signo _U_)
 {
   wait(NULL);
 }
-#endif /* WIN32 */
+#endif /* HAVE_FORK && HAVE_VFORK */
 
 static void
 info(register int verbose)
@@ -1485,34 +1487,41 @@ info(register int verbose)
        if (!verbose)
                fprintf(stderr, "%s: ", program_name);
 
-       (void)fprintf(stderr, "%u packets captured", packets_captured);
+       (void)fprintf(stderr, "%u packet%s captured", packets_captured,
+           PLURAL_SUFFIX(packets_captured));
        if (!verbose)
                fputs(", ", stderr);
        else
                putc('\n', stderr);
-       (void)fprintf(stderr, "%u packets received by filter", stat.ps_recv);
+       (void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
+           PLURAL_SUFFIX(stat.ps_recv));
        if (!verbose)
                fputs(", ", stderr);
        else
                putc('\n', stderr);
-       (void)fprintf(stderr, "%u packets dropped by kernel", stat.ps_drop);
+       (void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
+           PLURAL_SUFFIX(stat.ps_drop));
        if (stat.ps_ifdrop != 0) {
                if (!verbose)
                        fputs(", ", stderr);
                else
                        putc('\n', stderr);
-               (void)fprintf(stderr, "%u packets dropped by interface\n",
-                   stat.ps_ifdrop);
+               (void)fprintf(stderr, "%u packet%s dropped by interface\n",
+                   stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
        } else
                putc('\n', stderr);
        infoprint = 0;
 }
 
-#ifndef WIN32
+#if defined(HAVE_FORK) || defined(HAVE_VFORK)
 static void
 compress_savefile(const char *filename)
 {
+# ifdef HAVE_FORK
        if (fork())
+# else
+       if (vfork())
+# endif
                return;
        /*
         * Set to lowest priority so that this doesn't disturb the capture
@@ -1528,15 +1537,20 @@ compress_savefile(const char *filename)
                        zflag,
                        filename,
                        strerror(errno));
+# ifdef HAVE_FORK
+       exit(1);
+# else
+       _exit(1);
+# endif
 }
-#else  /* WIN32 */
+#else  /* HAVE_FORK && HAVE_VFORK */
 static void
 compress_savefile(const char *filename)
 {
        fprintf(stderr,
-               "compress_savefile failed. Functionality not implemented under windows\n");
+               "compress_savefile failed. Functionality not implemented under your system\n");
 }
-#endif /* WIN32 */
+#endif /* HAVE_FORK && HAVE_VFORK */
 
 static void
 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
@@ -1706,6 +1720,11 @@ print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
                 hdrlen = (*print_info->p.printer)(h, sp);
         }
                 
+       /*
+        * Restore the original snapend, as a printer might have
+        * changed it.
+        */
+       snapend = sp + h->caplen;
        if (Xflag) {
                /*
                 * Print the raw packet data in hex and ASCII.