X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/3566552dfece671eb6ac8e6db268af0e12a655bf..1afd3f308e25f7bf070f3932a28ed6b2be8173f6:/tcpdump.c

diff --git a/tcpdump.c b/tcpdump.c
index 5f3bde56..c43ab854 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -589,6 +589,8 @@ static void
 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 {
         char *filename = malloc(NAME_MAX + 1);
+        if (filename == NULL)
+            error("Makefilename: malloc);
 
         /* Process with strftime if Gflag is set. */
         if (Gflag != 0) {
@@ -630,6 +632,40 @@ static int tcpdump_printf(netdissect_options *ndo _U_,
   return ret;
 }
 
+struct print_info get_print_info(int type) {
+	struct print_info printinfo;
+
+	printinfo.ndo_type = 1;
+	printinfo.ndo = gndo;
+	printinfo.p.ndo_printer = lookup_ndo_printer(type);
+	if (printinfo.p.ndo_printer == NULL) {
+		printinfo.p.printer = lookup_printer(type);
+		printinfo.ndo_type = 0;
+		if (printinfo.p.printer == NULL) {
+			gndo->ndo_dltname = pcap_datalink_val_to_name(type);
+			if (gndo->ndo_dltname != NULL)
+				error("packet printing is not supported for link type %s: use -w",
+				      gndo->ndo_dltname);
+			else
+				error("packet printing is not supported for link type %d: use -w", type);
+		}
+	}
+	return (printinfo);
+}
+
+char *get_next_file(FILE *VFile, char *ptr) {
+	char *ret;
+
+	ret = fgets(ptr, NAME_MAX, VFile);
+	if (!ret)
+		return NULL;
+
+	if (ptr[strlen(ptr) - 1] == '\n')
+		ptr[strlen(ptr) - 1] = '\0';
+
+	return ret;
+}
+
 int
 main(int argc, char **argv)
 {
@@ -639,6 +675,7 @@ main(int argc, char **argv)
 	pcap_handler callback;
 	int type;
 	int dlt;
+	int new_dlt;
 	const char *dlt_name;
 	struct bpf_program fcode;
 #ifndef WIN32
@@ -1116,19 +1153,16 @@ main(int argc, char **argv)
 #endif /* WIN32 */
 		if (VFileName != NULL) {
 			if (VFileName[0] == '-' && VFileName[1] == '\0')
-				VFile = fopen("/dev/stdin", "r");
+				VFile = stdin;
 			else
 				VFile = fopen(VFileName, "r");
 
 			if (VFile == NULL)
 				error("Unable to open file: %s\n", strerror(errno));
 
-			ret = fgets(VFileLine, NAME_MAX, VFile);
+			ret = get_next_file(VFile, VFileLine);
 			if (!ret)
-				error("Nothing in %s\n", VFile);
-
-			if (VFileLine[strlen(VFileLine) - 1] == '\n')
-				VFileLine[strlen(VFileLine) - 1] = '\0';
+				error("Nothing in %s\n", VFileName);
 			RFileName = VFileLine;
 		}
 
@@ -1413,21 +1447,7 @@ main(int argc, char **argv)
 #endif
 	} else {
 		type = pcap_datalink(pd);
-                printinfo.ndo_type = 1;
-                printinfo.ndo = gndo;
-		printinfo.p.ndo_printer = lookup_ndo_printer(type);
-                if (printinfo.p.ndo_printer == NULL) {
-                        printinfo.p.printer = lookup_printer(type);
-                        printinfo.ndo_type = 0;
-                        if (printinfo.p.printer == NULL) {
-                                gndo->ndo_dltname = pcap_datalink_val_to_name(type);
-                                if (gndo->ndo_dltname != NULL)
-                                        error("packet printing is not supported for link type %s: use -w",
-                                              gndo->ndo_dltname);
-                                else
-                                        error("packet printing is not supported for link type %d: use -w", type);
-                        }
-                }
+		printinfo = get_print_info(type);
 		callback = print_packet;
 		pcap_userdata = (u_char *)&printinfo;
 	}
@@ -1511,24 +1531,25 @@ main(int argc, char **argv)
 		}
 		pcap_close(pd);
 		if (VFileName != NULL) {
-			ret = fgets(VFileLine, NAME_MAX, VFile);
+			ret = get_next_file(VFile, VFileLine);
 			if (ret) {
-				if (VFileLine[strlen(VFileLine) - 1] == '\n')
-					VFileLine[strlen(VFileLine) - 1] = '\0';
 				RFileName = VFileLine;
 				pd = pcap_open_offline(RFileName, ebuf);
 				if (pd == NULL)
 					error("%s", ebuf);
-				dlt = pcap_datalink(pd);
-				dlt_name = pcap_datalink_val_to_name(dlt);
+				new_dlt = pcap_datalink(pd);
+				if (WFileName && new_dlt != dlt)
+					error("%s: new dlt does not match original", RFileName);
+				printinfo = get_print_info(new_dlt);
+				dlt_name = pcap_datalink_val_to_name(new_dlt);
 				if (dlt_name == NULL) {
 					fprintf(stderr, "reading from file %s, link-type %u\n",
-					RFileName, dlt);
+					RFileName, new_dlt);
 				} else {
 					fprintf(stderr,
 					"reading from file %s, link-type %s (%s)\n",
 					RFileName, dlt_name,
-					pcap_datalink_val_to_description(dlt));
+					pcap_datalink_val_to_description(new_dlt));
 				}
 				if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 					error("%s", pcap_geterr(pd));