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.

diff --git a/src/mans/oping.pod b/src/mans/oping.pod
index 29784a8..8a3cb58 100644 (file)
--- 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 (file)
--- 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;