X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/1b15fedd1cb65a9d00c1d03bf7652e197006d19d..56a6db2e51fbfc67c77962d2e336f58e704a3f01:/tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index 4e524082..587ed321 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -87,6 +87,12 @@ extern int SIZE_BUF;
 #define NAME_MAX 255
 #endif
 
+#ifdef SIGINFO
+#define SIGNAL_REQ_INFO SIGINFO
+#elif SIGUSR1
+#define SIGNAL_REQ_INFO SIGUSR1
+#endif
+
 netdissect_options Gndo;
 netdissect_options *gndo = &Gndo;
 
@@ -115,10 +121,11 @@ static void ndo_default_print(netdissect_options *, const u_char *, u_int);
 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 static void droproot(const char *, const char *);
-static void ndo_error(netdissect_options *ndo, const char *fmt, ...);
+static void ndo_error(netdissect_options *ndo, const char *fmt, ...)
+     __attribute__ ((noreturn, format (printf, 2, 3)));
 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 
-#ifdef SIGINFO
+#ifdef SIGNAL_REQ_INFO
 RETSIGTYPE requestinfo(int);
 #endif
 
@@ -133,10 +140,6 @@ RETSIGTYPE requestinfo(int);
 static void info(int);
 static u_int packets_captured;
 
-typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
-typedef u_int (*if_ndo_printer)(struct netdissect_options *ndo,
-                                const struct pcap_pkthdr *, const u_char *);
-
 struct printer {
         if_printer f;
 	int type;
@@ -154,7 +157,6 @@ static struct printer printers[] = {
 #ifdef DLT_ARCNET_LINUX
 	{ arcnet_linux_if_print, DLT_ARCNET_LINUX },
 #endif
-	{ ether_if_print,	DLT_EN10MB },
 	{ token_if_print,	DLT_IEEE802 },
 #ifdef DLT_LANE8023
 	{ lane_if_print,        DLT_LANE8023 },
@@ -306,6 +308,7 @@ static struct printer printers[] = {
 };
 
 static struct ndo_printer ndo_printers[] = {
+	{ ether_if_print,	DLT_EN10MB },
 #ifdef DLT_IPNET
 	{ ipnet_if_print,	DLT_IPNET },
 #endif
@@ -314,11 +317,20 @@ static struct ndo_printer ndo_printers[] = {
 #endif
 #ifdef DLT_IEEE802_15_4_NOFCS
 	{ ieee802_15_4_if_print, DLT_IEEE802_15_4_NOFCS },
+#endif
+#ifdef DLT_PPI
+	{ ppi_if_print,		DLT_PPI },
+#endif
+#ifdef DLT_NETANALYZER
+	{ netanalyzer_if_print, DLT_NETANALYZER },
+#endif
+#ifdef DLT_NETANALYZER_TRANSPARENT
+	{ netanalyzer_transparent_if_print, DLT_NETANALYZER_TRANSPARENT },
 #endif
 	{ NULL,			0 },
 };
 
-static if_printer
+if_printer
 lookup_printer(int type)
 {
 	struct printer *p;
@@ -331,7 +343,7 @@ lookup_printer(int type)
 	/* NOTREACHED */
 }
 
-static if_ndo_printer
+if_ndo_printer
 lookup_ndo_printer(int type)
 {
 	struct ndo_printer *p;
@@ -652,9 +664,8 @@ main(int argc, char **argv)
 	smiInit("tcpdump");
 #endif
 
-	opterr = 0;
 	while (
-	    (op = getopt(argc, argv, "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:Yz:Z:")) != -1)
+	    (op = getopt(argc, argv, "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:Yz:Z:")) != -1)
 		switch (op) {
 
 		case 'a':
@@ -748,7 +759,11 @@ main(int argc, char **argv)
 			break;
 
 		case 'h':
-			++hflag;
+			usage();
+			break;
+
+		case 'H':
+			++Hflag;
 			break;
 
 		case 'i':
@@ -924,6 +939,8 @@ main(int argc, char **argv)
 				packettype = PT_TFTP;
 			else if (strcasecmp(optarg, "aodv") == 0)
 				packettype = PT_AODV;
+			else if (strcasecmp(optarg, "carp") == 0)
+				packettype = PT_CARP;
 			else
 				error("unknown packet type `%s'", optarg);
 			break;
@@ -1250,14 +1267,40 @@ 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)
 		(void)setsignal(SIGHUP, oldhandler);
 #endif /* WIN32 */
 
+#ifndef WIN32
+	/*
+	 * If a user name was specified with "-Z", attempt to switch to
+	 * that user's UID.  This would probably be used with sudo,
+	 * to allow tcpdump to be run in a special restricted
+	 * account (if you just want to allow users to open capture
+	 * devices, and can't just give users that permission,
+	 * you'd make tcpdump set-UID or set-GID).
+	 *
+	 * Tcpdump doesn't necessarily write only to one savefile;
+	 * the general only way to allow a -Z instance to write to
+	 * savefiles as the user under whose UID it's run, rather
+	 * than as the user specified with -Z, would thus be to switch
+	 * to the original user ID before opening a capture file and
+	 * then switch back to the -Z user ID after opening the savefile.
+	 * Switching to the -Z user ID only after opening the first
+	 * savefile doesn't handle the general case.
+	 */
+	if (getuid() == 0 || geteuid() == 0) {
+		if (username || chroot_dir)
+			droproot(username, chroot_dir);
+	}
+#endif /* WIN32 */
+
 	if (pcap_setfilter(pd, &fcode) < 0)
 		error("%s", pcap_geterr(pd));
 	if (WFileName) {
@@ -1311,23 +1354,14 @@ main(int argc, char **argv)
 		callback = print_packet;
 		pcap_userdata = (u_char *)&printinfo;
 	}
-#ifndef WIN32
-	/*
-	 * We cannot do this earlier, because we want to be able to open
-	 * the file (if done) for writing before giving up permissions.
-	 */
-	if (getuid() == 0 || geteuid() == 0) {
-		if (username || chroot_dir)
-			droproot(username, chroot_dir);
-	}
-#endif /* WIN32 */
-#ifdef SIGINFO
+
+#ifdef SIGNAL_REQ_INFO
 	/*
 	 * We can't get statistics when reading from a file rather
 	 * than capturing from a device.
 	 */
 	if (RFileName == NULL)
-		(void)setsignal(SIGINFO, requestinfo);
+		(void)setsignal(SIGNAL_REQ_INFO, requestinfo);
 #endif
 
 	if (vflag > 0 && WFileName) {
@@ -1449,13 +1483,13 @@ 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)
@@ -1476,34 +1510,41 @@ 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
@@ -1519,15 +1560,20 @@ 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)
@@ -1804,7 +1850,7 @@ default_print(const u_char *bp, u_int length)
 	ndo_default_print(gndo, bp, length);
 }
 
-#ifdef SIGINFO
+#ifdef SIGNAL_REQ_INFO
 RETSIGTYPE requestinfo(int signo _U_)
 {
 	if (infodelay)
@@ -1866,7 +1912,7 @@ usage(void)
 #endif /* WIN32 */
 #endif /* HAVE_PCAP_LIB_VERSION */
 	(void)fprintf(stderr,
-"Usage: %s [-aAbd" D_FLAG "ef" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
+"Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
 	(void)fprintf(stderr,
 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
 	(void)fprintf(stderr,