UDP socket edits by Erik Zandvliet

lib/socket.cpp

@@ -971,12 +971,18 @@ int Socket::Server::getSocket() {
 /// If both fail, prints an DLVL_FAIL debug message.
 /// \param nonblock Whether the socket should be nonblocking.
 Socket::UDPConnection::UDPConnection(bool nonblock) {
+#ifdef __CYGWIN__
+#warning UDP over IPv6 is currently disabled on windows
+  isIPv6 = false;
+  sock = socket(AF_INET, SOCK_DGRAM, 0);
+#else
   isIPv6 = true;
   sock = socket(AF_INET6, SOCK_DGRAM, 0);
   if (sock == -1) {
     sock = socket(AF_INET, SOCK_DGRAM, 0);
     isIPv6 = false;
   }
+#endif
   if (sock == -1) {
     DEBUG_MSG(DLVL_FAIL, "Could not create UDP socket: %s", strerror(errno));
   }
@@ -995,18 +1001,18 @@ Socket::UDPConnection::UDPConnection(bool nonblock) {
 /// Copies a UDP socket, re-allocating local copies of any needed structures.
 /// The data/data_size/data_len variables are *not* copied over.
 Socket::UDPConnection::UDPConnection(const UDPConnection & o) {
+#ifdef __CYGWIN__
+#warning UDP over IPv6 is currently disabled on windows
+  isIPv6 = false;
+  sock = socket(AF_INET, SOCK_DGRAM, 0);
+#else
   isIPv6 = true;
   sock = socket(AF_INET6, SOCK_DGRAM, 0);
   if (sock == -1) {
     sock = socket(AF_INET, SOCK_DGRAM, 0);
     isIPv6 = false;
-  }else{
-#ifdef __CYGWIN__
-    // Under windows, turn IPv6-only mode off.
-    int on = 0;
-    setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
-#endif
   }
+#endif
   if (sock == -1) {
     DEBUG_MSG(DLVL_FAIL, "Could not create UDP socket: %s", strerror(errno));
   }
@@ -1144,7 +1150,8 @@ void Socket::UDPConnection::SendNow(const char * sdata, size_t len) {
 /// If that fails too, gives up and returns zero.
 /// Prints a debug message at DLVL_FAIL level if binding failed.
 /// \return Actually bound port number, or zero on error.
-int Socket::UDPConnection::bind(int port, std::string iface) {
+int Socket::UDPConnection::bind(int port, std::string iface, const std::string & multicastInterfaces) {
+  int result = 0;
   if (isIPv6) {
     struct sockaddr_in6 s6;
     memset(&s6, 0, sizeof(s6));
@@ -1157,32 +1164,60 @@ int Socket::UDPConnection::bind(int port, std::string iface) {
     s6.sin6_port = htons(port);
     int r = ::bind(sock, (sockaddr *)&s6, sizeof(s6));
     if (r == 0) {
-      return ntohs(s6.sin6_port);
+      result = ntohs(s6.sin6_port);
     }
   } else {
     struct sockaddr_in s4;
     memset(&s4, 0, sizeof(s4));
     s4.sin_family = AF_INET;
     if (iface == "0.0.0.0" || iface.length() == 0) {
-      s4.sin_addr.s_addr = INADDR_ANY;
+      s4.sin_addr.s_addr = htonl(INADDR_ANY);
     } else {
       inet_pton(AF_INET, iface.c_str(), &s4.sin_addr);
     }
     s4.sin_port = htons(port);
     int r = ::bind(sock, (sockaddr *)&s4, sizeof(s4));
     if (r == 0) {
-      return ntohs(s4.sin_port);
+      result = ntohs(s4.sin_port);
     }
   }
+  if (!result){
     DEBUG_MSG(DLVL_FAIL, "Could not bind %s UDP socket to port %d: %s", isIPv6 ? "IPv6" : "IPv4", port, strerror(errno));
     return 0;
   }
+  //Detect multicast
+  if (iface.length() && ((atoi(iface.c_str()) & 0xE0) == 0xE0)){
+    if (!multicastInterfaces.length()){
+      WARN_MSG("Multicast IP given without any defined interfaces");
+    }else{
+      struct ip_mreq group;
+      inet_pton(AF_INET, iface.c_str(), &group.imr_multiaddr.s_addr);
+      size_t loc = 0;
+      while (loc != std::string::npos){
+        size_t nxtPos = multicastInterfaces.find(',', loc);
+        std::string curIface = multicastInterfaces.substr(loc, (nxtPos == std::string::npos ? nxtPos : nxtPos - loc));
+        inet_pton(AF_INET, curIface.c_str(), &group.imr_interface.s_addr);
+        if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&group, sizeof(group)) < 0) {
+          WARN_MSG("Unable to register for multicast on interface %s: %s", curIface.c_str() , strerror(errno));
+        }
+        loc = (nxtPos == std::string::npos ? nxtPos : nxtPos + 1);
+      }
+    }
+  }
+  return result;
+}
 
 /// Attempt to receive a UDP packet.
 /// This will automatically allocate or resize the internal data buffer if needed.
 /// If a packet is received, it will be placed in the "data" member, with it's length in "data_len".
 /// \return True if a packet was received, false otherwise.
 bool Socket::UDPConnection::Receive() {
+#ifdef __CYGWIN__
+  if (data_size != SOCKETSIZE){
+    data = (char *)realloc(data, SOCKETSIZE);
+    data_size = SOCKETSIZE;
+  }
+#endif
   int r = recvfrom(sock, data, data_size, MSG_PEEK | MSG_TRUNC, 0, 0);
   if (r == -1) {
     if (errno != EAGAIN) {

lib/socket.h

@@ -137,7 +137,7 @@ namespace Socket {
       UDPConnection(bool nonblock = false);
       ~UDPConnection();
       int getSock();
-      int bind(int port, std::string iface = "");
+      int bind(int port, std::string iface = "", const std::string & multicastAddress = "");
       void setBlocking(bool blocking);
       void SetDestination(std::string hostname, uint32_t port);
       void GetDestination(std::string & hostname, uint32_t & port);