Multicast socket API

net/udp/udp_socket_libevent.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/udp/udp_socket_libevent.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <netdb.h>
 #include <sys/socket.h>
@@ skipping 23 matching lines @@
 }  // namespace net
 
 namespace net {
 
 UDPSocketLibevent::UDPSocketLibevent(
     DatagramSocket::BindType bind_type,
     const RandIntCallback& rand_int_cb,
     net::NetLog* net_log,
     const net::NetLog::Source& source)
         : socket_(kInvalidSocket),
-          socket_options_(0),
+          addr_family_(0),
+          socket_options_(SOCKET_OPTION_MULTICAST_LOOP),
+          multicast_time_to_live_(1),
           bind_type_(bind_type),
           rand_int_cb_(rand_int_cb),
           read_watcher_(this),
           write_watcher_(this),
           read_buf_len_(0),
           recv_from_address_(NULL),
           write_buf_len_(0),
           net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_UDP_SOCKET)) {
   net_log_.BeginEvent(NetLog::TYPE_SOCKET_ALIVE,
                       source.ToEventParametersCallback());
@@ skipping 301 matching lines @@
         CreateNetLogUDPDataTranferCallback(
             result, bytes,
             is_address_valid ? &address : NULL));
   }
 
   base::StatsCounter read_bytes("udp.read_bytes");
   read_bytes.Add(result);
 }
 
 int UDPSocketLibevent::CreateSocket(const IPEndPoint& address) {
-  socket_ = socket(address.GetSockAddrFamily(), SOCK_DGRAM, 0);
+  addr_family_ = address.GetSockAddrFamily();
+  socket_ = socket(addr_family_, SOCK_DGRAM, 0);
   if (socket_ == kInvalidSocket)
     return MapSystemError(errno);
   if (SetNonBlocking(socket_)) {
     const int err = MapSystemError(errno);
     Close();
     return err;
   }
   return OK;
 }
 
@@ skipping 92 matching lines @@
       return MapSystemError(errno);
   }
   if (socket_options_ & SOCKET_OPTION_BROADCAST) {
     int rv;
 #if defined(OS_MACOSX)
     // SO_REUSEPORT on OSX permits multiple processes to each receive
     // UDP multicast or broadcast datagrams destined for the bound
     // port.
     rv = setsockopt(socket_, SOL_SOCKET, SO_REUSEPORT, &true_value,
                     sizeof(true_value));
-    if (rv < 0)
-      return MapSystemError(errno);
-#endif  // defined(OS_MACOSX)
+#else
     rv = setsockopt(socket_, SOL_SOCKET, SO_BROADCAST, &true_value,
                     sizeof(true_value));
+#endif  // defined(OS_MACOSX)
     if (rv < 0)
       return MapSystemError(errno);
   }
+
+  if (!(socket_options_ & SOCKET_OPTION_MULTICAST_LOOP)) {
+    int rv;
+    if (addr_family_ == AF_INET) {
+      u_char loop = 0;
+      rv = setsockopt(socket_, IPPROTO_IP, IP_MULTICAST_LOOP,
+                      &loop, sizeof(loop));
+    } else {
+      u_int loop = 0;
+      rv = setsockopt(socket_, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
+                      &loop, sizeof(loop));
+    }
+    if (rv < 0)
+      return MapSystemError(errno);
+  }
+  if (multicast_time_to_live_ != IP_DEFAULT_MULTICAST_TTL) {
+    int rv;
+    if (addr_family_ == AF_INET) {
+      u_char ttl = multicast_time_to_live_;
+      rv = setsockopt(socket_, IPPROTO_IP, IP_MULTICAST_TTL,
+                      &ttl, sizeof(ttl));
+    } else {
+      // Signed interger. -1 to use route default.
+      int ttl = multicast_time_to_live_;
+      rv = setsockopt(socket_, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
+                      &ttl, sizeof(ttl));
+    }
+    if (rv < 0)
+      return MapSystemError(errno);
+  }
   return OK;
 }
 
 int UDPSocketLibevent::DoBind(const IPEndPoint& address) {
   SockaddrStorage storage;
   if (!address.ToSockAddr(storage.addr, &storage.addr_len))
     return ERR_UNEXPECTED;
   int rv = bind(socket_, storage.addr, storage.addr_len);
   return rv < 0 ? MapSystemError(errno) : rv;
 }
 
 int UDPSocketLibevent::RandomBind(const IPEndPoint& address) {
   DCHECK(bind_type_ == DatagramSocket::RANDOM_BIND && !rand_int_cb_.is_null());
 
   // Construct IPAddressNumber of appropriate size (IPv4 or IPv6) of 0s.
   IPAddressNumber ip(address.address().size());
 
   for (int i = 0; i < kBindRetries; ++i) {
     int rv = DoBind(IPEndPoint(ip, rand_int_cb_.Run(kPortStart, kPortEnd)));
     if (rv == OK || rv != ERR_ADDRESS_IN_USE)
       return rv;
   }
   return DoBind(IPEndPoint(ip, 0));
 }
 
+int UDPSocketLibevent::JoinGroup(const IPAddressNumber& group_address) const {
+  DCHECK(CalledOnValidThread());
+  if(!is_connected())

[wtc, 2013/04/23 22:15:26]

Add a space between "if" and the opening parenthesis "(".
This is recommended by the Style Guide.

Make the same change to the other three if statements you
added, and also to udp_socket_win.cc.

[Bei Zhang, 2013/04/24 16:50:50]

Done.

+    return ERR_SOCKET_NOT_CONNECTED;
+
+  switch (group_address.size()) {
+    case kIPv4AddressSize: {
+      if (addr_family_ != AF_INET)
+        return ERR_ADDRESS_INVALID;
+      ip_mreq mreq;
+      mreq.imr_interface.s_addr = INADDR_ANY;
+      memcpy(&mreq.imr_multiaddr, &group_address[0], kIPv4AddressSize);
+      int rv = setsockopt(socket_, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+                          &mreq, sizeof(mreq));
+      if (rv < 0)
+        return MapSystemError(errno);
+      return OK;
+    }
+    case kIPv6AddressSize: {
+      if (addr_family_ != AF_INET6)
+        return ERR_ADDRESS_INVALID;
+      ipv6_mreq mreq;
+      mreq.ipv6mr_interface = 0;  // 0 indicates default multicast interface.
+      memcpy(&mreq.ipv6mr_multiaddr, &group_address[0], kIPv6AddressSize);
+      int rv = setsockopt(socket_, IPPROTO_IPV6, IPV6_JOIN_GROUP,
+                          &mreq, sizeof(mreq));
+      if (rv < 0)
+        return MapSystemError(errno);
+      return OK;
+    }
+    default:
+      NOTREACHED() << "Invalid address family";
+      return ERR_ADDRESS_INVALID;
+  }
+}
+
+int UDPSocketLibevent::LeaveGroup(const IPAddressNumber& group_address) const {
+  DCHECK(CalledOnValidThread());
+
+  if(!is_connected())
+    return ERR_SOCKET_NOT_CONNECTED;
+
+  switch (group_address.size()) {
+    case kIPv4AddressSize: {
+      if (addr_family_ != AF_INET)
+        return ERR_ADDRESS_INVALID;
+      ip_mreq mreq;
+      mreq.imr_interface.s_addr = INADDR_ANY;
+      memcpy(&mreq.imr_multiaddr, &group_address[0], kIPv4AddressSize);
+      int rv = setsockopt(socket_, IPPROTO_IP, IP_DROP_MEMBERSHIP,
+                          &mreq, sizeof(mreq));
+      if (rv < 0)
+        return MapSystemError(errno);
+      return OK;
+    }
+    case kIPv6AddressSize: {
+      if (addr_family_ != AF_INET6)
+        return ERR_ADDRESS_INVALID;
+      ipv6_mreq mreq;
+      mreq.ipv6mr_interface = 0;  // 0 indicates default multicast interface.
+      memcpy(&mreq.ipv6mr_multiaddr, &group_address[0], kIPv6AddressSize);
+      int rv = setsockopt(socket_, IPPROTO_IPV6, IPV6_LEAVE_GROUP,
+                          &mreq, sizeof(mreq));
+      if (rv < 0)
+        return MapSystemError(errno);
+      return OK;
+    }
+    default:
+      NOTREACHED() << "Invalid address family";
+      return ERR_ADDRESS_INVALID;
+  }
+}
+
+int UDPSocketLibevent::SetMulticastTimeToLive(int time_to_live) {
+  DCHECK(CalledOnValidThread());
+  if(is_connected())
+    return ERR_UNEXPECTED;

[wtc, 2013/04/23 22:15:26]

We should add a new error code ERR_SOCKET_IS_CONNECTED.
Let's do that in a separate CL.

[Bei Zhang, 2013/04/24 16:50:50]

Created a bug at http://crbug.com/235066 .

On 2013/04/23 22:15:26, wtc wrote:

+
+  if (time_to_live < 0 || time_to_live > 255)
+    return ERR_INVALID_ARGUMENT;
+  multicast_time_to_live_ = time_to_live;
+  return OK;
+}
+
+int UDPSocketLibevent::SetMulticastLoopbackMode(bool loopback) {
+  DCHECK(CalledOnValidThread());
+  if(is_connected())
+    return ERR_UNEXPECTED;
+
+  if (loopback)
+    socket_options_ |= SOCKET_OPTION_MULTICAST_LOOP;
+  else
+    socket_options_ &= ~SOCKET_OPTION_MULTICAST_LOOP;
+  return OK;
+}
 }  // namespace net