X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/0d1a405289e19c154d3b28d5c9e244fd13492810..4a2fb51da7ada0cecf94a5a94c7146bc36dd72b0:/tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index 52dbf7e5..bde74864 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -189,6 +189,9 @@ static void print_version(void);
 static void print_usage(void);
 static void show_tstamp_types_and_exit(const char *device) __attribute__((noreturn));
 static void show_dlts_and_exit(const char *device) __attribute__((noreturn));
+#ifdef HAVE_PCAP_FINDALLDEVS
+static void show_devices_and_exit (void) __attribute__((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 *);
@@ -828,7 +831,7 @@ copy_argv(register char **argv)
 	char *src, *dst;
 
 	p = argv;
-	if (*p == 0)
+	if (*p == NULL)
 		return 0;
 
 	while (*p)
@@ -958,8 +961,17 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
 
 #ifdef HAVE_PCAP_CREATE
 	pc = pcap_create(device, ebuf);
-	if (pc == NULL)
+	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(device);
@@ -1070,9 +1082,18 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
 #else /* HAVE_PCAP_CREATE */
 	*ebuf = '\0';
 	pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, 1000, ebuf);
-	if (pc == NULL)
+	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);
-	else if (*ebuf)
+	}
+	if (*ebuf)
 		warning("%s", ebuf);
 #endif /* HAVE_PCAP_CREATE */