Multi-networking with Android L.

webrtc/base/physicalsocketserver.cc

Index: webrtc/base/physicalsocketserver.cc
diff --git a/webrtc/base/physicalsocketserver.cc b/webrtc/base/physicalsocketserver.cc
index 4a4c0a36ba923323bcd21c57b24e9f3341ba591f..513110890844e697bd46d5e0a4834693ea375052 100644
--- a/webrtc/base/physicalsocketserver.cc
+++ b/webrtc/base/physicalsocketserver.cc
@@ -14,6 +14,8 @@
 
 #include <assert.h>
 
+#include <dlfcn.h>
+
 #ifdef MEMORY_SANITIZER
 #include <sanitizer/msan_interface.h>
 #endif
@@ -97,6 +99,11 @@ static const int ICMP_HEADER_SIZE = 8u;
 static const int ICMP_PING_TIMEOUT_MILLIS = 10000u;
 #endif
 
+static const int ERR_NOT_IMPLEMENTED = -11;
+static const int ERR_NETWORK_CHANGED = -21;
+static const int ERR_FAILED = -1;
+static const uint32_t INVALID_NETWORK_HANDLE = 0xFFFFFFFF;
+
 class PhysicalSocket : public AsyncSocket, public sigslot::has_slots<> {
  public:
   PhysicalSocket(PhysicalSocketServer* ss, SOCKET s = INVALID_SOCKET)
@@ -181,6 +188,54 @@ class PhysicalSocket : public AsyncSocket, public sigslot::has_slots<> {
     return err;
   }
 
+  int BindToNetwork(NetworkHandle network) override {
+    LOG(LS_INFO) << "Bind socket " << s_ << " to network " << network;
+    if (network == INVALID_NETWORK_HANDLE)
+      return -1;
+#if defined(ANDROID) && !defined(WEBRTC_CHROMIUM_BUILD)
+    // Android prior to Lollipop didn't have support for binding sockets to
+    // networks.
+    // if (base::android::BuildInfo::GetInstance()->sdk_int() <
+    //    base::android::SDK_VERSION_LOLLIPOP) {
+    //  return ERR_NOT_IMPLEMENTED;
+    //}
+
+    // NOTE: This does rely on Android implementation details, but
+    // these details are unlikely to change.
+    typedef int (*SetNetworkForSocket)(unsigned netId, int socketFd);
+    static SetNetworkForSocket setNetworkForSocket;
+    // This is racy, but all racers should come out with the same answer so it
+    // shouldn't matter.
+    if (setNetworkForSocket == nullptr) {
+      // Android's netd client library should always be loaded in our address
+      // space as it shims libc functions like connect().
+      const std::string net_library_path = "libnetd_client.so";
+      LOG(LS_ERROR) << "Load Library " << net_library_path;
+      void* lib = dlopen(net_library_path.c_str(), RTLD_LAZY);
+      if (lib == nullptr) {
+        LOG(LS_ERROR) << "Library " << net_library_path << " not found!";
+        return ERR_NOT_IMPLEMENTED;
+      }
+      setNetworkForSocket = reinterpret_cast<SetNetworkForSocket>(
+          dlsym(lib, "setNetworkForSocket"));
+    }
+    if (setNetworkForSocket == nullptr) {
+      LOG(LS_ERROR) << "symbole not found "; 
+      return ERR_NOT_IMPLEMENTED;
+    }
+    int rv = setNetworkForSocket(network, s_);
+    // If |network| has since disconnected, |rv| will be ENONET.  Surface this
+    // as
+    // ERR_NETWORK_CHANGED, rather than MapSystemError(ENONET) which gives back
+    // the less descriptive ERR_FAILED.
+    if (rv == ENONET)
+      return ERR_NETWORK_CHANGED;
+    return ERR_FAILED;
+#else
+    return ERR_NOT_IMPLEMENTED;
+#endif
+  }
+
   int Connect(const SocketAddress& addr) override {
     // TODO: Implicit creation is required to reconnect...
     // ...but should we make it more explicit?
@@ -1138,7 +1193,7 @@ class SocketDispatcher : public Dispatcher, public PhysicalSocket {
 
 int SocketDispatcher::next_id_ = 0;
 
-#endif  // WEBRTC_WIN 
+#endif  // WEBRTC_WIN
 
 // Sets the value of a boolean value to false when signaled.
 class Signaler : public EventDispatcher {
@@ -1632,6 +1687,6 @@ bool PhysicalSocketServer::Wait(int cmsWait, bool process_io) {
   // Done
   return true;
 }
-#endif  // WEBRTC_WIN 
+#endif  // WEBRTC_WIN
 
 }  // namespace rtc