From db767e93a313902cfbdfd33a6f9b3e4054bcf1f0 Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Fri, 17 Jul 2009 14:14:18 +0200
Subject: [PATCH] src/oping.c: Added -D <interface name> command line option.

This option sets the outgoing network device to use.

I decided not to reuse the -I command line option for that purpose (which is
what GNU ping is doing), for the following reasons:

 * In theory, an interface name could be confused with a host name.
 * Imho, it's better to specify things explicitly.
 * This approach is more flexible.
---
 src/mans/oping.pod |  9 +++++++--
 src/oping.c        | 17 ++++++++++++++++-
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/mans/oping.pod b/src/mans/oping.pod
index 29784a8..8a3cb58 100644
--- a/src/mans/oping.pod
+++ b/src/mans/oping.pod
@@ -45,8 +45,13 @@ including) 1E<nbsp>andE<nbsp>255. If omitted, the value B<64> is used.
 
 =item B<-I> I<address>
 
-Set the source address to use. You B<cannot> pass the interface name, as you
-can with GNU's L<ping(8)>.
+Set the source address to use. You may either specify an IP number or a
+hostname. You B<cannot> pass the interface name, as you can with GNU's
+L<ping(8)> - use the B<-D> option for that purpose.
+
+=item B<-D> I<interface name>
+
+Set the outgoing network device to use.
 
 =item B<-f> I<filename>
 
diff --git a/src/oping.c b/src/oping.c
index a1dbade..fc4cb5f 100644
--- a/src/oping.c
+++ b/src/oping.c
@@ -73,6 +73,7 @@ typedef struct ping_context
 static double  opt_interval   = 1.0;
 static int     opt_addrfamily = PING_DEF_AF;
 static char   *opt_srcaddr    = NULL;
+static char   *opt_device     = NULL;
 static char   *opt_filename   = NULL;
 static int     opt_count      = -1;
 static int     opt_send_ttl   = 64;
@@ -122,6 +123,7 @@ static void usage_exit (const char *name, int status)
 			"  -i interval  interval with which to send ICMP packets\n"
 			"  -t ttl       time to live for each ICMP packet\n"
 			"  -I srcaddr   source address\n"
+			"  -D device    outgoing interface name\n"
 			"  -f filename  filename to read hosts from\n"
 
 			"\noping "PACKAGE_VERSION", http://verplant.org/liboping/\n"
@@ -137,7 +139,7 @@ static int read_options (int argc, char **argv)
 
 	while (1)
 	{
-		optchar = getopt (argc, argv, "46c:hi:I:t:f:");
+		optchar = getopt (argc, argv, "46c:hi:I:t:f:D:");
 
 		if (optchar == -1)
 			break;
@@ -188,6 +190,10 @@ static int read_options (int argc, char **argv)
 				}
 				break;
 
+			case 'D':
+				opt_device = optarg;
+				break;
+
 			case 't':
 			{
 				int new_send_ttl;
@@ -375,6 +381,15 @@ int main (int argc, char **argv)
 		}
 	}
 
+	if (opt_device != NULL)
+	{
+		if (ping_setopt (ping, PING_OPT_DEVICE, (void *) opt_device) != 0)
+		{
+			fprintf (stderr, "Setting device failed: %s\n",
+					ping_get_error (ping));
+		}
+	}
+
 	if (opt_filename != NULL)
 	{
 		FILE *infile;
-- 
2.11.0