Add --time-t-size option to print the size of time_t in bits

Have tests/TESTrun run "./tcpdump --time-t-size and set HAVE_TIME_T_64
key based on that.

This will permit to run tests based on time_t size (32-bit or 64-bit).

Author: fxlb

tcpdump.c

@@ -641,6 +641,7 @@ show_remote_devices_and_exit(void)
 #define OPTION_COUNT			136
 #define OPTION_PRINT_SAMPLING		137
 #define OPTION_LENGTHS			138
+#define OPTION_TIME_T_SIZE		139
 
 static const struct option longopts[] = {
 	{ "buffer-size", required_argument, NULL, 'B' },
@@ -682,6 +683,7 @@ static const struct option longopts[] = {
 	{ "print", no_argument, NULL, OPTION_PRINT },
 	{ "print-sampling", required_argument, NULL, OPTION_PRINT_SAMPLING },
 	{ "lengths", no_argument, NULL, OPTION_LENGTHS },
+	{ "time-t-size", no_argument, NULL, OPTION_TIME_T_SIZE },
 	{ "version", no_argument, NULL, OPTION_VERSION },
 	{ NULL, 0, NULL, 0 }
 };
@@ -1870,6 +1872,10 @@ main(int argc, char **argv)
 			ndo->ndo_lengths = 1;
 			break;
 
+		case OPTION_TIME_T_SIZE:
+			printf("%zu\n", sizeof(time_t) * 8);
+			return 0;
+
 		case OPTION_VERSION:
 			print_version(stdout);
 			exit_tcpdump(S_SUCCESS);

tests/TESTrun

@@ -390,6 +390,17 @@ sub loadconfighash {
     printf "$TCPDUMP --fp-type => %s\n", $have_fptype;
     $main::confighhash->{$have_fptype} = 1;
 
+    # run tcpdump --time-t-size to get the size of size_t in bits
+    open(TIMETSIZE_PIPE, "$TCPDUMP --time-t-size |") or die("piping tcpdump --time-t-size failed\n");
+    my $time_t_size = <TIMETSIZE_PIPE>;
+    close(TIMETSIZE_PIPE);
+    my $have_time_t_64;
+    if($time_t_size == "64") {
+        $have_time_t_64 = "HAVE_TIME_T_64";
+    }
+    printf "$TCPDUMP --time-t-size => %s\n", $time_t_size;
+    $main::confighhash->{$have_time_t_64} = 1;
+
     # and check whether this is OpenBSD, as one test fails in OpenBSD
     # due to the sad hellscape of low-numbered DLT_ values, due to
     # 12 meaning "OpenBSD loopback" rather than "raw IP" on OpenBSD