X-Git-Url: https://git.distorted.org.uk/~mdw/disorder/blobdiff_plain/803f6e5279ec2531f5073d351009f1e105420d25..01f871b46afe3cd78e311f0344d002d844baf2b9:/server/speaker-network.c

diff --git a/server/speaker-network.c b/server/speaker-network.c
index fab81a8..c81b7db 100644
--- a/server/speaker-network.c
+++ b/server/speaker-network.c
@@ -30,6 +30,8 @@
 #include <sys/socket.h>
 #include <sys/uio.h>
 #include <assert.h>
+#include <net/if.h>
+#include <ifaddrs.h>
 
 #include "configuration.h"
 #include "syscalls.h"
@@ -37,6 +39,7 @@
 #include "addr.h"
 #include "timeval.h"
 #include "rtp.h"
+#include "ifreq.h"
 #include "speaker-protocol.h"
 #include "speaker.h"
 
@@ -119,8 +122,51 @@ static void network_init(void) {
                    res->ai_socktype,
                    res->ai_protocol)) < 0)
     fatal(errno, "error creating broadcast socket");
-  if(setsockopt(bfd, SOL_SOCKET, SO_BROADCAST, &one, sizeof one) < 0)
-    fatal(errno, "error setting SO_BROADCAST on broadcast socket");
+  if((res->ai_family == PF_INET
+      && IN_MULTICAST(
+           ntohl(((struct sockaddr_in *)res->ai_addr)->sin_addr.s_addr)
+         ))
+     || (res->ai_family == PF_INET6
+         && IN6_IS_ADDR_MULTICAST(
+               &((struct sockaddr_in6 *)res->ai_addr)->sin6_addr
+            ))) {
+    /* Multicasting */
+    switch(res->ai_family) {
+    case PF_INET: {
+      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");
+      break;
+    }
+    case PF_INET6: {
+      const int mttl = config->multicast_ttl;
+      if(setsockopt(bfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
+                    &mttl, sizeof mttl) < 0)
+        fatal(errno, "error setting IPV6_MULTICAST_HOPS on multicast socket");
+      break;
+    }
+    default:
+      fatal(0, "unsupported address family %d", res->ai_family);
+    }
+    info("multicasting on %s", sockname);
+  } else {
+    struct ifaddrs *ifs;
+
+    if(getifaddrs(&ifs) < 0)
+      fatal(errno, "error calling getifaddrs");
+    while(ifs) {
+      if((ifs->ifa_flags & IFF_BROADCAST)
+         && sockaddr_equal(ifs->ifa_broadaddr, res->ai_addr))
+        break;
+      ifs = ifs->ifa_next;
+    }
+    if(ifs) {
+      if(setsockopt(bfd, SOL_SOCKET, SO_BROADCAST, &one, sizeof one) < 0)
+        fatal(errno, "error setting SO_BROADCAST on broadcast socket");
+      info("broadcasting on %s (%s)", sockname, ifs->ifa_name);
+    } else
+      info("unicasting on %s", sockname);
+  }
   len = sizeof sndbuf;
   if(getsockopt(bfd, SOL_SOCKET, SO_SNDBUF,
                 &sndbuf, &len) < 0)