X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/759f3de8db3ec94bbbd1ba6038763279536ff735..817aadf8bb2f67efced4c26f7335db0f64d67783:/tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index 4f42f4b2..e0237061 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -130,7 +130,19 @@ The Regents of the University of California.  All rights reserved.\n";
 static int 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 */
-static int dflag;			/* print filter code */
+/*
+ * This is exported because, in some versions of libpcap, if libpcap
+ * is built with optimizer debugging code (which is *NOT* the default
+ * configuration!), the library *imports*(!) a variable named dflag,
+ * under the expectation that tcpdump is exporting it, to govern
+ * how much debugging information to print when optimizing
+ * the generated BPF code.
+ *
+ * This is a horrible hack; newer versions of libpcap don't import
+ * dflag but, instead, *if* built with optimizer debugging code,
+ * *export* a routine to set that flag.
+ */
+int dflag;				/* print filter code */
 static int Gflag;			/* rotate dump files after this many seconds */
 static int Gflag_count;			/* number of files created with Gflag rotation */
 static time_t Gflag_time;		/* The last time_t the dump file was rotated. */
@@ -209,6 +221,57 @@ struct dump_info {
 #endif
 };
 
+#if defined(HAVE_PCAP_SET_PARSER_DEBUG)
+/*
+ * We have pcap_set_parser_debug() in libpcap; declare it (it's not declared
+ * by any libpcap header, because it's a special hack, only available if
+ * libpcap was configured to include it, and only intended for use by
+ * libpcap developers trying to debug the parser for filter expressions).
+ */
+#ifdef _WIN32
+__declspec(dllimport)
+#else /* _WIN32 */
+extern
+#endif /* _WIN32 */
+void pcap_set_parser_debug(int);
+#elif defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
+/*
+ * We don't have pcap_set_parser_debug() in libpcap, but we do have
+ * pcap_debug or yydebug.  Make a local version of pcap_set_parser_debug()
+ * to set the flag, and define HAVE_PCAP_SET_PARSER_DEBUG.
+ */
+static void
+pcap_set_parser_debug(int value)
+{
+#ifdef HAVE_PCAP_DEBUG
+	extern int pcap_debug;
+
+	pcap_debug = value;
+#else /* HAVE_PCAP_DEBUG */
+	extern int yydebug;
+
+	yydebug = value;
+#endif /* HAVE_PCAP_DEBUG */
+}
+
+#define HAVE_PCAP_SET_PARSER_DEBUG
+#endif
+
+#if defined(HAVE_PCAP_SET_OPTIMIZER_DEBUG)
+/*
+ * We have pcap_set_optimizer_debug() in libpcap; declare it (it's not declared
+ * by any libpcap header, because it's a special hack, only available if
+ * libpcap was configured to include it, and only intended for use by
+ * libpcap developers trying to debug the optimizer for filter expressions).
+ */
+#ifdef _WIN32
+__declspec(dllimport)
+#else /* _WIN32 */
+extern
+#endif /* _WIN32 */
+void pcap_set_optimizer_debug(int);
+#endif
+
 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 static void
 show_tstamp_types_and_exit(const char *device)
@@ -453,7 +516,7 @@ static const struct option longopts[] = {
 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
 	{ "immediate-mode", no_argument, NULL, OPTION_IMMEDIATE_MODE },
 #endif
-#if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
+#ifdef HAVE_PCAP_SET_PARSER_DEBUG
 	{ "debug-filter-parser", no_argument, NULL, 'Y' },
 #endif
 	{ "relinquish-privileges", required_argument, NULL, 'Z' },
@@ -1104,30 +1167,20 @@ main(int argc, char **argv)
 				error("invalid data link type %s", yflag_dlt_name);
 			break;
 
-#if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
+#ifdef HAVE_PCAP_SET_PARSER_DEBUG
 		case 'Y':
 			{
 			/* Undocumented flag */
-#ifdef HAVE_PCAP_DEBUG
-			extern int pcap_debug;
-			pcap_debug = 1;
-#else
-			extern int yydebug;
-			yydebug = 1;
-#endif
+			pcap_set_parser_debug(1);
 			}
 			break;
 #endif
 		case 'z':
-			zflag = strdup(optarg);
-			if (zflag == NULL)
-				error("Unable to allocate memory for -z argument");
+			zflag = optarg;
 			break;
 
 		case 'Z':
-			username = strdup(optarg);
-			if (username == NULL)
-				error("Unable to allocate memory for -Z argument");
+			username = optarg;
 			break;
 
 		case '#':
@@ -1480,12 +1533,16 @@ main(int argc, char **argv)
 	else
 		cmdbuf = copy_argv(&argv[optind]);
 
+#ifdef HAVE_PCAP_SET_OPTIMIZER_DEBUG
+	pcap_set_optimizer_debug(dflag);
+#endif
 	if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 		error("%s", pcap_geterr(pd));
 	if (dflag) {
 		bpf_dump(&fcode, dflag);
 		pcap_close(pd);
 		free(cmdbuf);
+		pcap_freecode(&fcode);
 		exit(0);
 	}
 	init_print(ndo, localnet, netmask, timezone_offset);
@@ -1782,6 +1839,7 @@ main(int argc, char **argv)
 	while (ret != NULL);
 
 	free(cmdbuf);
+	pcap_freecode(&fcode);
 	exit(status == -1 ? 1 : 0);
 }
 
@@ -1884,18 +1942,31 @@ info(register int verbose)
 }
 
 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
+#ifdef HAVE_FORK
+#define fork_subprocess() fork()
+#else
+#define fork_subprocess() vfork()
+#endif
 static void
 compress_savefile(const char *filename)
 {
-# ifdef HAVE_FORK
-	#define test_fork fork()
-# else
-	#define test_fork vfork()
-# endif
-	if(test_fork)
+	pid_t child;
+
+	child = fork_subprocess();
+	if (child == -1) {
+		fprintf(stderr,
+			"compress_savefile: fork failed: %s\n",
+			pcap_strerror(errno));
+		return;
+	}
+	if (child != 0) {
+		/* Parent process. */
 		return;
+	}
+
 	/*
-	 * Set to lowest priority so that this doesn't disturb the capture
+	 * Child process.
+	 * Set to lowest priority so that this doesn't disturb the capture.
 	 */
 #ifdef NZERO
 	setpriority(PRIO_PROCESS, 0, NZERO - 1);
@@ -1904,15 +1975,15 @@ compress_savefile(const char *filename)
 #endif
 	if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
 		fprintf(stderr,
-			"compress_savefile:execlp(%s, %s): %s\n",
+			"compress_savefile: execlp(%s, %s) failed: %s\n",
 			zflag,
 			filename,
 			pcap_strerror(errno));
-# ifdef HAVE_FORK
+#ifdef HAVE_FORK
 	exit(1);
-# else
+#else
 	_exit(1);
-# endif
+#endif
 }
 #else  /* HAVE_FORK && HAVE_VFORK */
 static void