From: Richard Kettlewell <rjk@greenend.org.uk>
Date: Wed, 28 Nov 2007 20:41:54 +0000 (+0000)
Subject: multicast_loop option
X-Git-Tag: 1.5.99+dev10~47
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/commitdiff_plain/61941295f0eb457edc89f0337f732ff071838b6a

multicast_loop option
---

diff --git a/doc/disorder_config.5.in b/doc/disorder_config.5.in
index badedeb..2b57c79 100644
--- a/doc/disorder_config.5.in
+++ b/doc/disorder_config.5.in
@@ -157,6 +157,8 @@ for more details.
 .B broadcast \fIADDRESS\fR \fIPORT\fR
 Transmit sound data to \fIADDRESS\fR using UDP port \fIPORT\fR.  This implies
 \fBspeaker_backend network\fR.
+.IP
+See also \fBmulticast_loop\fR and \fBmulticast_ttl\fR.
 .TP
 .B broadcast_from \fIADDRESS\fR \fIPORT\fR
 Sets the (local) source address used by \fBbroadcast\fR.
@@ -224,8 +226,14 @@ Determines whether the server locks against concurrent operation.  Default is
 The path to the mixer device, if you want access to the volume control,
 e.g. \fB/dev/mixer\fR.
 .TP
+.B multicast_loop yes\fR|\fBno
+Determines whether multicast packets are loop backed to the sending host.  The
+default is \fByes\fR.  This only applies if
+\fBspeaker_backend\fR is set to \fBnetwork\fR and \fBbroadcast\fR is actually a
+multicast address.
+.TP
 .B multicast_ttl \fIHOPS\fR
-Set the maximum number of hops to send multicast packets.  This only applies is
+Set the maximum number of hops to send multicast packets.  This only applies if
 \fBspeaker_backend\fR is set to \fBnetwork\fR and \fBbroadcast\fR is actually a
 multicast address.
 .TP
diff --git a/lib/configuration.c b/lib/configuration.c
index d758751..90ff371 100644
--- a/lib/configuration.c
+++ b/lib/configuration.c
@@ -900,6 +900,7 @@ static const struct conf conf[] = {
   { C(listen),           &type_stringlist,       validate_port },
   { C(lock),             &type_boolean,          validate_any },
   { C(mixer),            &type_string,           validate_ischr },
+  { C(multicast_loop),   &type_boolean,          validate_any },
   { C(multicast_ttl),    &type_integer,          validate_non_negative },
   { C(namepart),         &type_namepart,         validate_any },
   { C2(nice, nice_rescan), &type_integer,        validate_non_negative },
@@ -1043,6 +1044,7 @@ static struct config *config_default(void) {
   c->queue_pad = 10;
   c->speaker_backend = -1;
   c->multicast_ttl = 1;
+  c->multicast_loop = 1;
   c->authorization_algorithm = xstrdup("sha1");
   c->noticed_history = 31;
   c->short_display = 32;
diff --git a/lib/configuration.h b/lib/configuration.h
index a4ffa63..6618e1a 100644
--- a/lib/configuration.h
+++ b/lib/configuration.h
@@ -243,6 +243,9 @@ struct config {
   /** @brief TTL for multicast packets */
   long multicast_ttl;
 
+  /** @brief Whether to loop back multicast packets */
+  int multicast_loop;
+  
   /* derived values: */
   int nparts;				/* number of distinct name parts */
   char **parts;				/* name part list  */
diff --git a/server/speaker-network.c b/server/speaker-network.c
index 40abca5..150fea6 100644
--- a/server/speaker-network.c
+++ b/server/speaker-network.c
@@ -125,6 +125,9 @@ static void network_init(void) {
       const int mttl = config->multicast_ttl;
       if(setsockopt(bfd, IPPROTO_IP, IP_MULTICAST_TTL, &mttl, sizeof mttl) < 0)
         fatal(errno, "error setting IP_MULTICAST_TTL on multicast socket");
+      if(setsockopt(bfd, IPPROTO_IP, IP_MULTICAST_LOOP,
+                    &config->multicast_loop, sizeof one) < 0)
+        fatal(errno, "error setting IP_MULTICAST_LOOP on multicast socket");
       break;
     }
     case PF_INET6: {
@@ -132,6 +135,9 @@ static void network_init(void) {
       if(setsockopt(bfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
                     &mttl, sizeof mttl) < 0)
         fatal(errno, "error setting IPV6_MULTICAST_HOPS on multicast socket");
+      if(setsockopt(bfd, IPPROTO_IP, IPV6_MULTICAST_LOOP,
+                    &config->multicast_loop, sizeof (int)) < 0)
+        fatal(errno, "error setting IPV6_MULTICAST_LOOP on multicast socket");
       break;
     }
     default: