From: Richard Kettlewell <rjk@greenend.org.uk>
Date: Fri, 13 Mar 2009 21:41:16 +0000 (+0000)
Subject: Split up the multicast and unicast cases in disorder-playrtp; the
X-Git-Tag: 5.0~178^2~2
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/commitdiff_plain/983c335710951dd573e653b4da2a7a5d71b0aa9b?ds=sidebyside

Split up the multicast and unicast cases in disorder-playrtp; the
apparent commonalities are not enough to be worth interleaving the two
cases.

In the multicast case, bind to the multicast address explicitly,
thereby allowing multiple processes on the same host to receive the
multicast packets.
---

diff --git a/clients/playrtp.c b/clients/playrtp.c
index 92cbb75..d97864b 100644
--- a/clients/playrtp.c
+++ b/clients/playrtp.c
@@ -580,6 +580,7 @@ int main(int argc, char **argv) {
   union any_sockaddr mgroup;
   const char *dumpfile = 0;
   pthread_t ltid;
+  static const int one = 1;
 
   static const struct addrinfo prefs = {
     .ai_flags = AI_PASSIVE,
@@ -651,8 +652,14 @@ int main(int argc, char **argv) {
                      res->ai_socktype,
                      res->ai_protocol)) < 0)
     fatal(errno, "error creating socket");
-  /* Stash the multicast group address */
-  if((is_multicast = multicast(res->ai_addr))) {
+  /* Allow multiple listeners */
+  xsetsockopt(rtpfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
+  is_multicast = multicast(res->ai_addr);
+  /* The multicast and unicast/broadcast cases are different enough that they
+   * are totally split.  Trying to find commonality between them causes more
+   * trouble that it's worth. */
+  if(is_multicast) {
+    /* Stash the multicast group address */
     memcpy(&mgroup, res->ai_addr, res->ai_addrlen);
     switch(res->ai_addr->sa_family) {
     case AF_INET:
@@ -661,24 +668,13 @@ int main(int argc, char **argv) {
     case AF_INET6:
       mgroup.in6.sin6_port = 0;
       break;
+    default:
+      fatal(0, "unsupported family %d", (int)res->ai_addr->sa_family);
     }
-  }
-  /* Bind to 0/port */
-  switch(res->ai_addr->sa_family) {
-  case AF_INET:
-    memset(&((struct sockaddr_in *)res->ai_addr)->sin_addr, 0,
-           sizeof (struct in_addr));
-    break;
-  case AF_INET6:
-    memset(&((struct sockaddr_in6 *)res->ai_addr)->sin6_addr, 0,
-           sizeof (struct in6_addr));
-    break;
-  default:
-    fatal(0, "unsupported family %d", (int)res->ai_addr->sa_family);
-  }
-  if(bind(rtpfd, res->ai_addr, res->ai_addrlen) < 0)
-    fatal(errno, "error binding socket to %s", sockname);
-  if(is_multicast) {
+    /* Bind to to the multicast group address */
+    if(bind(rtpfd, res->ai_addr, res->ai_addrlen) < 0)
+      fatal(errno, "error binding socket to %s", format_sockaddr(res->ai_addr));
+    /* Add multicast group membership */
     switch(mgroup.sa.sa_family) {
     case PF_INET:
       mreq.imr_multiaddr = mgroup.in.sin_addr;
@@ -697,10 +693,35 @@ int main(int argc, char **argv) {
     default:
       fatal(0, "unsupported address family %d", res->ai_family);
     }
+    /* Report what we did */
     info("listening on %s multicast group %s",
          format_sockaddr(res->ai_addr), format_sockaddr(&mgroup.sa));
-  } else
+  } else {
+    /* Bind to 0/port */
+    switch(res->ai_addr->sa_family) {
+    case AF_INET: {
+      struct sockaddr_in *in = (struct sockaddr_in *)res->ai_addr;
+      
+      memset(&in->sin_addr, 0, sizeof (struct in_addr));
+      if(bind(rtpfd, res->ai_addr, res->ai_addrlen) < 0)
+        fatal(errno, "error binding socket to 0.0.0.0 port %d",
+              ntohs(in->sin_port));
+      break;
+    }
+    case AF_INET6: {
+      struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)res->ai_addr;
+      
+      memset(&in6->sin6_addr, 0, sizeof (struct in6_addr));
+      break;
+    }
+    default:
+      fatal(0, "unsupported family %d", (int)res->ai_addr->sa_family);
+    }
+    if(bind(rtpfd, res->ai_addr, res->ai_addrlen) < 0)
+      fatal(errno, "error binding socket to %s", format_sockaddr(res->ai_addr));
+    /* Report what we did */
     info("listening on %s", format_sockaddr(res->ai_addr));
+  }
   len = sizeof rcvbuf;
   if(getsockopt(rtpfd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &len) < 0)
     fatal(errno, "error calling getsockopt SO_RCVBUF");