Allows to specify a capture file at command line

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>

2 files changed, 8 insertions, 1 deletions

diff --git a/README.md b/README.md
index 0cf8c94..b1f98d4 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,8 @@ Currently requires root privileges as use tun/tap.
   * `--port` *port*:
     specify the port to use for client/server.
     The default is `61234`.
+  * `--cap-file` *filename*:
+    specify a file name to write captured packets (in tcpdump/pcap format).
   * `--help`:
     show usage help.
 
diff --git a/latency.c b/latency.c
index c74388f..eacf349 100644
--- a/latency.c
+++ b/latency.c
@@ -66,6 +66,7 @@ usage(bool error)
 		"Options:\n"
 		"  -h, --help      Show this help\n"
 		"  --port <PORT>   Specify port to use (default 61234)\n"
+		"  --cap-file <FN> Specify a capture file\n"
 		);
 	exit(error ? EXIT_FAILURE : EXIT_SUCCESS);
 }
@@ -116,11 +117,12 @@ main(int argc, char **argv)
 	}
 
 	enum { MODE_local, MODE_server, MODE_client } mode = MODE_local;
-	enum { ARG_port = 256, ARG_client, ARG_server };
+	enum { ARG_port = 256, ARG_client, ARG_server, ARG_capfile };
 	static struct option long_options[] = {
 		{"client",  required_argument, 0,  ARG_client },
 		{"server",  no_argument,       0,  ARG_server },
 		{"port",    required_argument, 0,  ARG_port },
+		{"cap-file",required_argument, 0,  ARG_capfile },
 		{"help",    no_argument,       0,  'h' },
 		{0,         0,                 0,  0 }
 	};
@@ -146,6 +148,9 @@ main(int argc, char **argv)
 		case ARG_port:
 			str_port = optarg;
 			break;
+		case ARG_capfile:
+			tun_log_filename = optarg;
+			break;
 		default:
 			usage(true);
 		}