X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/12857bf113ae8409fbdf994ca9c6a5977dd77856..refs/heads/tcpdump-4.9:/tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index ff8d8e8c..8f27ba2a 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -108,6 +108,7 @@ The Regents of the University of California.  All rights reserved.\n";
 #endif /* HAVE_CAP_NG_H */
 #endif /* HAVE_LIBCAP_NG */
 
+#include "netdissect-stdinc.h"
 #include "netdissect.h"
 #include "interface.h"
 #include "addrtoname.h"
@@ -130,7 +131,7 @@ The Regents of the University of California.  All rights reserved.\n";
 #endif
 
 static int Bflag;			/* buffer size */
-static int Cflag;			/* rotate dump files after this many bytes */
+static long Cflag;			/* rotate dump files after this many bytes */
 static int Cflag_count;			/* Keep track of which file number we're writing */
 static int Dflag;			/* list available devices and exit */
 /*
@@ -157,7 +158,7 @@ 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 */
@@ -171,24 +172,18 @@ static int infoprint;
 char *program_name;
 
 /* Forwards */
-static void error(const char *, ...)
-     __attribute__((noreturn))
-#ifdef __ATTRIBUTE___FORMAT_OK
-     __attribute__((format (printf, 1, 2)))
-#endif /* __ATTRIBUTE___FORMAT_OK */
-     ;
-static void warning(const char *, ...)
-#ifdef __ATTRIBUTE___FORMAT_OK
-     __attribute__((format (printf, 1, 2)))
-#endif /* __ATTRIBUTE___FORMAT_OK */
-     ;
-static void exit_tcpdump(int) __attribute__((noreturn));
+static void error(FORMAT_STRING(const char *), ...) NORETURN PRINTFLIKE(1, 2);
+static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
+static void exit_tcpdump(int) NORETURN;
 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) NORETURN;
+static void show_dlts_and_exit(pcap_t *, const char *device) NORETURN;
+#ifdef HAVE_PCAP_FINDALLDEVS
+static void show_devices_and_exit (void) 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 +332,16 @@ 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 +365,15 @@ 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 +450,7 @@ 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
@@ -613,11 +608,10 @@ droproot(const char *username, const char *chroot_dir)
 #ifdef HAVE_LIBCAP_NG
 		{
 			int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
-			if (ret < 0) {
-				fprintf(stderr, "error : ret %d\n", ret);
-			} else {
+			if (ret < 0)
+				error("capng_change_id(): return %d\n", ret);
+			else
 				fprintf(stderr, "dropped privs to %s\n", username);
-			}
 		}
 #else
 		if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
@@ -640,12 +634,13 @@ 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 */
@@ -705,13 +700,15 @@ static char *
 get_next_file(FILE *VFile, char *ptr)
 {
 	char *ret;
+	size_t len;
 
 	ret = fgets(ptr, PATH_MAX, VFile);
 	if (!ret)
 		return NULL;
 
-	if (ptr[strlen(ptr) - 1] == '\n')
-		ptr[strlen(ptr) - 1] = '\0';
+	len = strlen (ptr);
+	if (len > 0 && ptr[len - 1] == '\n')
+		ptr[len - 1] = '\0';
 
 	return ret;
 }
@@ -865,15 +862,22 @@ read_infile(char *fname)
 {
 	register int i, fd, cc;
 	register char *cp;
-	struct stat buf;
+	our_statb buf;
 
 	fd = open(fname, O_RDONLY|O_BINARY);
 	if (fd < 0)
 		error("can't open %s: %s", fname, pcap_strerror(errno));
 
-	if (fstat(fd, &buf) < 0)
+	if (our_fstat(fd, &buf) < 0)
 		error("can't stat %s: %s", fname, pcap_strerror(errno));
 
+	/*
+	 * Reject files whose size doesn't fit into an int; a filter
+	 * *that* large will probably be too big.
+	 */
+	if (buf.st_size > INT_MAX)
+		error("%s is too large", fname);
+
 	cp = malloc((u_int)buf.st_size + 1);
 	if (cp == NULL)
 		error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
@@ -882,7 +886,8 @@ read_infile(char *fname)
 	if (cc < 0)
 		error("read %s: %s", fname, pcap_strerror(errno));
 	if (cc != buf.st_size)
-		error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
+		error("short read %s (%d != %d)", fname, (int) cc,
+		    (int)buf.st_size);
 
 	close(fd);
 	/* replace "# comment" with spaces */
@@ -971,7 +976,7 @@ open_interface(const char *device, netdissect_options *ndo, char *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);
@@ -1028,6 +1033,10 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
 		if (status < 0)
 			error("%s: Can't set time stamp type: %s",
 		              device, pcap_statustostr(status));
+		else if (status > 0)
+			warning("When trying to set timestamp type '%s' on %s: %s",
+				pcap_tstamp_type_val_to_name(jflag), device,
+				pcap_statustostr(status));
 	}
 #endif
 	status = pcap_activate(pc);
@@ -1042,9 +1051,9 @@ open_interface(const char *device, netdissect_options *ndo, char *ebuf)
 			/*
 			 * Return an error for our caller to handle.
 			 */
-			pcap_close(pc);
 			snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
 			    device, pcap_statustostr(status), cp);
+			pcap_close(pc);
 			return (NULL);
 		} else if (status == PCAP_ERROR_PERM_DENIED && *cp != '\0')
 			error("%s: %s\n(%s)", device,
@@ -1726,7 +1735,7 @@ 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)
@@ -1822,6 +1831,13 @@ 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(
@@ -1844,7 +1860,12 @@ main(int argc, char **argv)
 	if (RFileName == NULL && VFileName == NULL) {
 		static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
 
-		cap_rights_init(&rights, CAP_IOCTL, CAP_READ);
+		/*
+		 * The various libpcap devices use a combination of
+		 * read (bpf), ioctl (bpf, netmap), poll (netmap)
+		 * so we add the relevant access rights.
+		 */
+		cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
 		if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
 		    errno != ENOSYS) {
 			error("unable to limit pcap descriptor");
@@ -2319,6 +2340,7 @@ 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 */
 			}
@@ -2587,6 +2609,14 @@ print_version(void)
 	smi_version_string = nd_smi_version_string();
 	if (smi_version_string != NULL)
 		(void)fprintf (stderr, "SMI-library: %s\n", smi_version_string);
+
+#if defined(__SANITIZE_ADDRESS__)
+	(void)fprintf (stderr, "Compiled with AddressSanitizer/GCC.\n");
+#elif defined(__has_feature)
+#  if __has_feature(address_sanitizer)
+	(void)fprintf (stderr, "Compiled with AddressSanitizer/CLang.\n");
+#  endif
+#endif /* __SANITIZE_ADDRESS__ or __has_feature */
 }
 USES_APPLE_RST