clients/playrtp.c: Replace the hairy interface-scanning heuristics.

When we apply these heuristics, we already /have/ a known, working,
connection to the server.  So we can just use the address that the
kernel gave us for our stream reception address.

Replace the old hairy heuristics, and delete their support functions.

diff --git a/clients/playrtp.c b/clients/playrtp.c
index 3a4757bf755d6c5b24f5913139325d08a42251a3..c22998b6f522465b0c03ce9c47630e7795e10e39 100644 (file)
--- a/clients/playrtp.c
+++ b/clients/playrtp.c
@@ -635,53 +635,6 @@ static size_t playrtp_callback(void *buffer,
   return samples;
 }
 
-static int compare_family(const struct ifaddrs *a,
-                          const struct ifaddrs *b,
-                          int family) {
-  int afamily = a->ifa_addr->sa_family;
-  int bfamily = b->ifa_addr->sa_family;
-  if(afamily != bfamily) {
-    /* Preferred family wins */
-    if(afamily == family) return 1;
-    if(bfamily == family) return -1;
-    /* Either there's no preference or it doesn't help.  Prefer IPv4 */
-    if(afamily == AF_INET) return 1;
-    if(bfamily == AF_INET) return -1;
-    /* Failing that prefer IPv6 */
-    if(afamily == AF_INET6) return 1;
-    if(bfamily == AF_INET6) return -1;
-  }
-  return 0;
-}
-
-static int compare_flags(const struct ifaddrs *a,
-                         const struct ifaddrs *b) {
-  unsigned aflags = a->ifa_flags, bflags = b->ifa_flags;
-  /* Up interfaces are better than down ones */
-  unsigned aup = aflags & IFF_UP, bup = bflags & IFF_UP;
-  if(aup != bup)
-    return aup > bup ? 1 : -1;
-#if IFF_DYNAMIC
-  /* Static addresses are better than dynamic */
-  unsigned adynamic = aflags & IFF_DYNAMIC, bdynamic = bflags & IFF_DYNAMIC;
-  if(adynamic != bdynamic)
-    return adynamic < bdynamic ? 1 : -1;
-#endif
-  unsigned aloopback = aflags & IFF_LOOPBACK, bloopback = bflags & IFF_LOOPBACK;
-  /* Static addresses are better than dynamic */
-  if(aloopback != bloopback)
-    return aloopback < bloopback ? 1 : -1;
-  return 0;
-}
-
-static int compare_interfaces(const struct ifaddrs *a,
-                              const struct ifaddrs *b,
-                              int family) {
-  int c;
-  if((c = compare_family(a, b, family))) return c;
-  return compare_flags(a, b);
-}
-
 int main(int argc, char **argv) {
   int n, err;
   struct addrinfo *res;
@@ -840,30 +793,22 @@ int main(int argc, char **argv) {
       if(!(c = disorder_new(1))) exit(EXIT_FAILURE);
       if(disorder_connect(c)) exit(EXIT_FAILURE);
     }
-    /* If no address was given, pick something sensible based on the known-
-     * working connectivity to the server */
+    /* If no address was given, we need to pick one.  But we already have a
+     * connection to the server, so we can probably use the address from that.
+     */
+    struct sockaddr_storage ss;
     if(!node) {
-      int family = config->rtp_request_address.af;
-      if(family == AF_UNSPEC) family = disorder_client_af(c);
-      /* Get a list of interfaces */
-      struct ifaddrs *ifa, *bestifa = NULL;
-      if(getifaddrs(&ifa) < 0)
-        disorder_fatal(errno, "error calling getifaddrs");
-      /* Try to pick a good one */
-      for(; ifa; ifa = ifa->ifa_next) {
-        if(!ifa->ifa_addr) continue;
-        if(bestifa == NULL
-           || compare_interfaces(ifa, bestifa, family) > 0)
-          bestifa = ifa;
-      }
-      if(!bestifa)
-        disorder_fatal(0, "failed to select a network interface");
-      sa = bestifa->ifa_addr;
-      switch(sa->sa_family) {
-        case AF_INET: ((struct sockaddr_in *)sa)->sin_port = 0; break;
-        case AF_INET6: ((struct sockaddr_in6 *)sa)->sin6_port = 0; break;
-        default: assert(!"unexpected address family");
+      addr_len = sizeof ss;
+      if(disorder_client_sockname(c, (struct sockaddr *)&ss, &addr_len))
+        exit(EXIT_FAILURE);
+      if(ss.ss_family != AF_INET && ss.ss_family != AF_INET6) {
+        /* We're using a Unix-domain socket, so use a loopback address.  I'm
+         * cowardly using IPv4 here. */
+        struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
+        sin->sin_family = AF_INET;
+        sin->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
       }
+      sa = (struct sockaddr *)&ss;
       prefs.ai_family = sa->sa_family;
     }
     /* If we have an address or port to resolve then do that now */