X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/2a5873120688f77c2a544b45b6c340324283d46b..fc9abd5810adaa5ec755662dc98e472c797c47cb:/tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index e028d2e7..b0d3aa5b 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -38,7 +38,7 @@
 #endif
 
 /*
- * Some older versions of Mac OS X may ship pcap.h from libpcap 0.6 with a
+ * Some older versions of Mac OS X ship pcap.h from libpcap 0.6 with a
  * libpcap based on 0.8.  That means it has pcap_findalldevs() but the
  * header doesn't define pcap_if_t, meaning that we can't actually *use*
  * pcap_findalldevs().
@@ -833,6 +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) {
@@ -844,9 +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);
         }
@@ -898,6 +916,7 @@ capdns_setup(void)
 	if (cap_dns_type_limit(capdnsloc, types, 1) < 0)
 		error("unable to limit access to system.dns service");
 	families[0] = AF_INET;
+	/* Casper is a feature of FreeBSD, which defines AF_INET6. */
 	families[1] = AF_INET6;
 	if (cap_dns_family_limit(capdnsloc, families, 2) < 0)
 		error("unable to limit access to system.dns service");
@@ -2693,6 +2712,8 @@ DIAG_ON_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));
 				}
@@ -2743,7 +2764,14 @@ 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);
@@ -2808,7 +2836,7 @@ cleanup(int signo _U_)
 static void
 child_cleanup(int signo _U_)
 {
-  wait(NULL);
+  while (waitpid(-1, NULL, WNOHANG) >= 0);
 }
 #endif /* HAVE_FORK && HAVE_VFORK */