X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/0d1a405289e19c154d3b28d5c9e244fd13492810..6b8ed9649e08215cd2acf7702e178ce41b18d932:/tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index 52dbf7e5..73bf1387 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -157,7 +157,7 @@ static int Jflag;			/* list available time stamp types */
 static int jflag = -1;			/* packet time stamp source */
 static int pflag;			/* don't go promiscuous */
 #ifdef HAVE_PCAP_SETDIRECTION
-int Qflag = -1;				/* restrict captured packet by send/receive direction */
+static int Qflag = -1;			/* restrict captured packet by send/receive direction */
 #endif
 static int Uflag;			/* "unbuffered" output of dump files */
 static int Wflag;			/* recycle output files after this number of files */
@@ -187,8 +187,11 @@ static RETSIGTYPE cleanup(int);
 static RETSIGTYPE child_cleanup(int);
 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));
+static void show_tstamp_types_and_exit(pcap_t *, const char *device) __attribute__((noreturn));
+static void show_dlts_and_exit(pcap_t *, 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 *);
@@ -337,16 +340,16 @@ exit_tcpdump(int status)
 
 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 static void
-show_tstamp_types_and_exit(const char *device)
+show_tstamp_types_and_exit(pcap_t *pc, const char *device)
 {
 	int n_tstamp_types;
 	int *tstamp_types = 0;
 	const char *tstamp_type_name;
 	int i;
 
-	n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
+	n_tstamp_types = pcap_list_tstamp_types(pc, &tstamp_types);
 	if (n_tstamp_types < 0)
-		error("%s", pcap_geterr(pd));
+		error("%s", pcap_geterr(pc));
 
 	if (n_tstamp_types == 0) {
 		fprintf(stderr, "Time stamp type cannot be set for %s\n",
@@ -370,15 +373,15 @@ show_tstamp_types_and_exit(const char *device)
 #endif
 
 static void
-show_dlts_and_exit(const char *device)
+show_dlts_and_exit(pcap_t *pc, const char *device)
 {
 	int n_dlts, i;
 	int *dlts = 0;
 	const char *dlt_name;
 
-	n_dlts = pcap_list_datalinks(pd, &dlts);
+	n_dlts = pcap_list_datalinks(pc, &dlts);
 	if (n_dlts < 0)
-		error("%s", pcap_geterr(pd));
+		error("%s", pcap_geterr(pc));
 	else if (n_dlts == 0 || !dlts)
 		error("No data link types.");
 
@@ -455,7 +458,7 @@ show_devices_and_exit (void)
  * OS X tcpdump uses -g to force non--v output for IP to be on one
  * line, making it more "g"repable;
  *
- * OS X tcpdump uses -k tospecify that packet comments in pcap-ng files
+ * OS X tcpdump uses -k to specify that packet comments in pcap-ng files
  * should be printed;
  *
  * OpenBSD tcpdump uses -o to indicate that OS fingerprinting should be done
@@ -640,12 +643,13 @@ droproot(const char *username, const char *chroot_dir)
 		exit_tcpdump(1);
 	}
 #ifdef HAVE_LIBCAP_NG
-	/* We don't need CAP_SETUID and CAP_SETGID any more. */
+	/* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */
 	capng_updatev(
 		CAPNG_DROP,
 		CAPNG_EFFECTIVE | CAPNG_PERMITTED,
 		CAP_SETUID,
 		CAP_SETGID,
+		CAP_SYS_CHROOT,
 		-1);
 	capng_apply(CAPNG_SELECT_BOTH);
 #endif /* HAVE_LIBCAP_NG */
@@ -828,7 +832,7 @@ copy_argv(register char **argv)
 	char *src, *dst;
 
 	p = argv;
-	if (*p == 0)
+	if (*p == NULL)
 		return 0;
 
 	while (*p)
@@ -958,11 +962,20 @@ 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);
+		show_tstamp_types_and_exit(pc, device);
 #endif
 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
 	status = pcap_set_tstamp_precision(pc, ndo->ndo_tstamp_precision);
@@ -1070,9 +1083,18 @@ 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 */
 
@@ -1708,7 +1730,7 @@ main(int argc, char **argv)
 			}
 #endif /* !defined(HAVE_PCAP_CREATE) && defined(_WIN32) */
 		if (Lflag)
-			show_dlts_and_exit(device);
+			show_dlts_and_exit(pd, device);
 		if (yflag_dlt >= 0) {
 #ifdef HAVE_PCAP_SET_DATALINK
 			if (pcap_set_datalink(pd, yflag_dlt) < 0)
@@ -1804,6 +1826,13 @@ main(int argc, char **argv)
 				CAP_SETGID,
 				-1);
 		}
+		if (chroot_dir) {
+			capng_update(
+				CAPNG_ADD,
+				CAPNG_PERMITTED | CAPNG_EFFECTIVE,
+				CAP_SYS_CHROOT
+				);
+		}
 
 		if (WFileName) {
 			capng_update(
@@ -2301,6 +2330,7 @@ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *s
 			if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
 				(void)fprintf(stderr, "Maximum file limit reached: %d\n",
 				    Wflag);
+				info(1);
 				exit_tcpdump(0);
 				/* NOTREACHED */
 			}