Keep listening if "accept" returns an invalid socket.

webrtc/base/physicalsocketserver.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 26 matching lines @@
 #endif
 
 #include <algorithm>
 #include <map>
 
 #include "webrtc/base/arraysize.h"
 #include "webrtc/base/basictypes.h"
 #include "webrtc/base/byteorder.h"
 #include "webrtc/base/common.h"
 #include "webrtc/base/logging.h"
-#include "webrtc/base/nethelpers.h"
 #include "webrtc/base/physicalsocketserver.h"
 #include "webrtc/base/timeutils.h"
 #include "webrtc/base/winping.h"
 #include "webrtc/base/win32socketinit.h"
 
 // stm: this will tell us if we are on OSX
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
@@ skipping 32 matching lines @@
     68,     // Official minimum
     0,      // End of list marker
 };
 
 static const int IP_HEADER_SIZE = 20u;
 static const int IPV6_HEADER_SIZE = 40u;
 static const int ICMP_HEADER_SIZE = 8u;
 static const int ICMP_PING_TIMEOUT_MILLIS = 10000u;
 #endif
 
-class PhysicalSocket : public AsyncSocket, public sigslot::has_slots<> {
- public:
-  PhysicalSocket(PhysicalSocketServer* ss, SOCKET s = INVALID_SOCKET)
-    : ss_(ss), s_(s), enabled_events_(0), error_(0),
-      state_((s == INVALID_SOCKET) ? CS_CLOSED : CS_CONNECTED),
-      resolver_(NULL) {
+PhysicalSocket::PhysicalSocket(PhysicalSocketServer* ss, SOCKET s)
+  : ss_(ss), s_(s), enabled_events_(0), error_(0),
+    state_((s == INVALID_SOCKET) ? CS_CLOSED : CS_CONNECTED),
+    resolver_(nullptr) {
 #if defined(WEBRTC_WIN)
-    // EnsureWinsockInit() ensures that winsock is initialized. The default
-    // version of this function doesn't do anything because winsock is
-    // initialized by constructor of a static object. If neccessary libjingle
-    // users can link it with a different version of this function by replacing
-    // win32socketinit.cc. See win32socketinit.cc for more details.
-    EnsureWinsockInit();
-#endif
-    if (s_ != INVALID_SOCKET) {
-      enabled_events_ = DE_READ | DE_WRITE;
-
-      int type = SOCK_STREAM;
-      socklen_t len = sizeof(type);
-      VERIFY(0 == getsockopt(s_, SOL_SOCKET, SO_TYPE, (SockOptArg)&type, &len));
-      udp_ = (SOCK_DGRAM == type);
-    }
-  }
-
-  ~PhysicalSocket() override {
-    Close();
-  }
-
-  // Creates the underlying OS socket (same as the "socket" function).
-  virtual bool Create(int family, int type) {
-    Close();
-    s_ = ::socket(family, type, 0);
+  // EnsureWinsockInit() ensures that winsock is initialized. The default
+  // version of this function doesn't do anything because winsock is
+  // initialized by constructor of a static object. If neccessary libjingle
+  // users can link it with a different version of this function by replacing
+  // win32socketinit.cc. See win32socketinit.cc for more details.
+  EnsureWinsockInit();
+#endif
+  if (s_ != INVALID_SOCKET) {
+    enabled_events_ = DE_READ | DE_WRITE;
+
+    int type = SOCK_STREAM;
+    socklen_t len = sizeof(type);
+    VERIFY(0 == getsockopt(s_, SOL_SOCKET, SO_TYPE, (SockOptArg)&type, &len));
     udp_ = (SOCK_DGRAM == type);
-    UpdateLastError();
-    if (udp_)
-      enabled_events_ = DE_READ | DE_WRITE;
-    return s_ != INVALID_SOCKET;
-  }
-
-  SocketAddress GetLocalAddress() const override {
-    sockaddr_storage addr_storage = {0};
-    socklen_t addrlen = sizeof(addr_storage);
-    sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
-    int result = ::getsockname(s_, addr, &addrlen);
-    SocketAddress address;
-    if (result >= 0) {
-      SocketAddressFromSockAddrStorage(addr_storage, &address);
-    } else {
-      LOG(LS_WARNING) << "GetLocalAddress: unable to get local addr, socket="
-                      << s_;
-    }
-    return address;
-  }
-
-  SocketAddress GetRemoteAddress() const override {
-    sockaddr_storage addr_storage = {0};
-    socklen_t addrlen = sizeof(addr_storage);
-    sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
-    int result = ::getpeername(s_, addr, &addrlen);
-    SocketAddress address;
-    if (result >= 0) {
-      SocketAddressFromSockAddrStorage(addr_storage, &address);
-    } else {
-      LOG(LS_WARNING) << "GetRemoteAddress: unable to get remote addr, socket="
-                      << s_;
-    }
-    return address;
-  }
-
-  int Bind(const SocketAddress& bind_addr) override {
-    sockaddr_storage addr_storage;
-    size_t len = bind_addr.ToSockAddrStorage(&addr_storage);
-    sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
-    int err = ::bind(s_, addr, static_cast<int>(len));
-    UpdateLastError();
+  }
+}
+
+PhysicalSocket::~PhysicalSocket() {
+  Close();
+}
+
+bool PhysicalSocket::Create(int family, int type) {
+  Close();
+  s_ = ::socket(family, type, 0);
+  udp_ = (SOCK_DGRAM == type);
+  UpdateLastError();
+  if (udp_)
+    enabled_events_ = DE_READ | DE_WRITE;
+  return s_ != INVALID_SOCKET;
+}
+
+SocketAddress PhysicalSocket::GetLocalAddress() const {
+  sockaddr_storage addr_storage = {0};
+  socklen_t addrlen = sizeof(addr_storage);
+  sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
+  int result = ::getsockname(s_, addr, &addrlen);
+  SocketAddress address;
+  if (result >= 0) {
+    SocketAddressFromSockAddrStorage(addr_storage, &address);
+  } else {
+    LOG(LS_WARNING) << "GetLocalAddress: unable to get local addr, socket="
+                    << s_;
+  }
+  return address;
+}
+
+SocketAddress PhysicalSocket::GetRemoteAddress() const {
+  sockaddr_storage addr_storage = {0};
+  socklen_t addrlen = sizeof(addr_storage);
+  sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
+  int result = ::getpeername(s_, addr, &addrlen);
+  SocketAddress address;
+  if (result >= 0) {
+    SocketAddressFromSockAddrStorage(addr_storage, &address);
+  } else {
+    LOG(LS_WARNING) << "GetRemoteAddress: unable to get remote addr, socket="
+                    << s_;
+  }
+  return address;
+}
+
+int PhysicalSocket::Bind(const SocketAddress& bind_addr) {
+  sockaddr_storage addr_storage;
+  size_t len = bind_addr.ToSockAddrStorage(&addr_storage);
+  sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
+  int err = ::bind(s_, addr, static_cast<int>(len));
+  UpdateLastError();
 #if !defined(NDEBUG)
-    if (0 == err) {
-      dbg_addr_ = "Bound @ ";
-      dbg_addr_.append(GetLocalAddress().ToString());
-    }
-#endif
-    return err;
-  }
-
-  int Connect(const SocketAddress& addr) override {
-    // TODO: Implicit creation is required to reconnect...
-    // ...but should we make it more explicit?
-    if (state_ != CS_CLOSED) {
-      SetError(EALREADY);
-      return SOCKET_ERROR;
-    }
-    if (addr.IsUnresolvedIP()) {
-      LOG(LS_VERBOSE) << "Resolving addr in PhysicalSocket::Connect";
-      resolver_ = new AsyncResolver();
-      resolver_->SignalDone.connect(this, &PhysicalSocket::OnResolveResult);
-      resolver_->Start(addr);
-      state_ = CS_CONNECTING;
+  if (0 == err) {
+    dbg_addr_ = "Bound @ ";
+    dbg_addr_.append(GetLocalAddress().ToString());
+  }
+#endif
+  return err;
+}
+
+int PhysicalSocket::Connect(const SocketAddress& addr) {
+  // TODO: Implicit creation is required to reconnect...
+  // ...but should we make it more explicit?
+  if (state_ != CS_CLOSED) {
+    SetError(EALREADY);
+    return SOCKET_ERROR;
+  }
+  if (addr.IsUnresolvedIP()) {
+    LOG(LS_VERBOSE) << "Resolving addr in PhysicalSocket::Connect";
+    resolver_ = new AsyncResolver();
+    resolver_->SignalDone.connect(this, &PhysicalSocket::OnResolveResult);
+    resolver_->Start(addr);
+    state_ = CS_CONNECTING;
+    return 0;
+  }
+
+  return DoConnect(addr);
+}
+
+int PhysicalSocket::DoConnect(const SocketAddress& connect_addr) {
+  if ((s_ == INVALID_SOCKET) &&
+      !Create(connect_addr.family(), SOCK_STREAM)) {
+    return SOCKET_ERROR;
+  }
+  sockaddr_storage addr_storage;
+  size_t len = connect_addr.ToSockAddrStorage(&addr_storage);
+  sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
+  int err = ::connect(s_, addr, static_cast<int>(len));
+  UpdateLastError();
+  if (err == 0) {
+    state_ = CS_CONNECTED;
+  } else if (IsBlockingError(GetError())) {
+    state_ = CS_CONNECTING;
+    enabled_events_ |= DE_CONNECT;
+  } else {
+    return SOCKET_ERROR;
+  }
+
+  enabled_events_ |= DE_READ | DE_WRITE;
+  return 0;
+}
+
+int PhysicalSocket::GetError() const {
+  CritScope cs(&crit_);
+  return error_;
+}
+
+void PhysicalSocket::SetError(int error) {
+  CritScope cs(&crit_);
+  error_ = error;
+}
+
+int PhysicalSocket::GetOption(Option opt, int* value) {
+  int slevel;
+  int sopt;
+  if (TranslateOption(opt, &slevel, &sopt) == -1)
+    return -1;
+  socklen_t optlen = sizeof(*value);
+  int ret = ::getsockopt(s_, slevel, sopt, (SockOptArg)value, &optlen);
+  if (ret != -1 && opt == OPT_DONTFRAGMENT) {
+#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
+    *value = (*value != IP_PMTUDISC_DONT) ? 1 : 0;
+#endif
+  }
+  return ret;
+}
+
+int PhysicalSocket::SetOption(Option opt, int value) {
+  int slevel;
+  int sopt;
+  if (TranslateOption(opt, &slevel, &sopt) == -1)
+    return -1;
+  if (opt == OPT_DONTFRAGMENT) {
+#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
+    value = (value) ? IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
+#endif
+  }
+  return ::setsockopt(s_, slevel, sopt, (SockOptArg)&value, sizeof(value));
+}
+
+int PhysicalSocket::Send(const void* pv, size_t cb) {
+  int sent = ::send(s_, reinterpret_cast<const char *>(pv), (int)cb,
+#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
+      // Suppress SIGPIPE. Without this, attempting to send on a socket whose
+      // other end is closed will result in a SIGPIPE signal being raised to
+      // our process, which by default will terminate the process, which we
+      // don't want. By specifying this flag, we'll just get the error EPIPE
+      // instead and can handle the error gracefully.
+      MSG_NOSIGNAL
+#else
+      0
+#endif
+      );
+  UpdateLastError();
+  MaybeRemapSendError();
+  // We have seen minidumps where this may be false.
+  ASSERT(sent <= static_cast<int>(cb));
+  if ((sent < 0) && IsBlockingError(GetError())) {
+    enabled_events_ |= DE_WRITE;
+  }
+  return sent;
+}
+
+int PhysicalSocket::SendTo(const void* buffer,
+                           size_t length,
+                           const SocketAddress& addr) {
+  sockaddr_storage saddr;
+  size_t len = addr.ToSockAddrStorage(&saddr);
+  int sent = ::sendto(
+      s_, static_cast<const char *>(buffer), static_cast<int>(length),
+#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
+      // Suppress SIGPIPE. See above for explanation.
+      MSG_NOSIGNAL,
+#else
+      0,
+#endif
+      reinterpret_cast<sockaddr*>(&saddr), static_cast<int>(len));
+  UpdateLastError();
+  MaybeRemapSendError();
+  // We have seen minidumps where this may be false.
+  ASSERT(sent <= static_cast<int>(length));
+  if ((sent < 0) && IsBlockingError(GetError())) {
+    enabled_events_ |= DE_WRITE;
+  }
+  return sent;
+}
+
+int PhysicalSocket::Recv(void* buffer, size_t length) {
+  int received = ::recv(s_, static_cast<char*>(buffer),
+                        static_cast<int>(length), 0);
+  if ((received == 0) && (length != 0)) {
+    // Note: on graceful shutdown, recv can return 0.  In this case, we
+    // pretend it is blocking, and then signal close, so that simplifying
+    // assumptions can be made about Recv.
+    LOG(LS_WARNING) << "EOF from socket; deferring close event";
+    // Must turn this back on so that the select() loop will notice the close
+    // event.
+    enabled_events_ |= DE_READ;
+    SetError(EWOULDBLOCK);
+    return SOCKET_ERROR;
+  }
+  UpdateLastError();
+  int error = GetError();
+  bool success = (received >= 0) || IsBlockingError(error);
+  if (udp_ || success) {
+    enabled_events_ |= DE_READ;
+  }
+  if (!success) {
+    LOG_F(LS_VERBOSE) << "Error = " << error;
+  }
+  return received;
+}
+
+int PhysicalSocket::RecvFrom(void* buffer,
+                             size_t length,
+                             SocketAddress* out_addr) {
+  sockaddr_storage addr_storage;
+  socklen_t addr_len = sizeof(addr_storage);
+  sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
+  int received = ::recvfrom(s_, static_cast<char*>(buffer),
+                            static_cast<int>(length), 0, addr, &addr_len);
+  UpdateLastError();
+  if ((received >= 0) && (out_addr != nullptr))
+    SocketAddressFromSockAddrStorage(addr_storage, out_addr);
+  int error = GetError();
+  bool success = (received >= 0) || IsBlockingError(error);
+  if (udp_ || success) {
+    enabled_events_ |= DE_READ;
+  }
+  if (!success) {
+    LOG_F(LS_VERBOSE) << "Error = " << error;
+  }
+  return received;
+}
+
+int PhysicalSocket::Listen(int backlog) {
+  int err = ::listen(s_, backlog);
+  UpdateLastError();
+  if (err == 0) {
+    state_ = CS_CONNECTING;
+    enabled_events_ |= DE_ACCEPT;
+#if !defined(NDEBUG)
+    dbg_addr_ = "Listening @ ";
+    dbg_addr_.append(GetLocalAddress().ToString());
+#endif
+  }
+  return err;
+}
+
+AsyncSocket* PhysicalSocket::Accept(SocketAddress* out_addr) {
+  // Always re-subscribe DE_ACCEPT to make sure new incoming connections will
+  // trigger an event even if DoAccept returns an error here.
+  enabled_events_ |= DE_ACCEPT;
+  sockaddr_storage addr_storage;
+  socklen_t addr_len = sizeof(addr_storage);
+  sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
+  SOCKET s = DoAccept(s_, addr, &addr_len);
+  UpdateLastError();
+  if (s == INVALID_SOCKET)
+    return nullptr;
+  if (out_addr != nullptr)
+    SocketAddressFromSockAddrStorage(addr_storage, out_addr);
+  return ss_->WrapSocket(s);
+}
+
+int PhysicalSocket::Close() {
+  if (s_ == INVALID_SOCKET)
+    return 0;
+  int err = ::closesocket(s_);
+  UpdateLastError();
+  s_ = INVALID_SOCKET;
+  state_ = CS_CLOSED;
+  enabled_events_ = 0;
+  if (resolver_) {
+    resolver_->Destroy(false);
+    resolver_ = nullptr;
+  }
+  return err;
+}
+
+int PhysicalSocket::EstimateMTU(uint16_t* mtu) {
+  SocketAddress addr = GetRemoteAddress();
+  if (addr.IsAnyIP()) {
+    SetError(ENOTCONN);
+    return -1;
+  }
+
+#if defined(WEBRTC_WIN)
+  // Gets the interface MTU (TTL=1) for the interface used to reach |addr|.
+  WinPing ping;
+  if (!ping.IsValid()) {
+    SetError(EINVAL);  // can't think of a better error ID
+    return -1;
+  }
+  int header_size = ICMP_HEADER_SIZE;
+  if (addr.family() == AF_INET6) {
+    header_size += IPV6_HEADER_SIZE;
+  } else if (addr.family() == AF_INET) {
+    header_size += IP_HEADER_SIZE;
+  }
+
+  for (int level = 0; PACKET_MAXIMUMS[level + 1] > 0; ++level) {
+    int32_t size = PACKET_MAXIMUMS[level] - header_size;
+    WinPing::PingResult result = ping.Ping(addr.ipaddr(), size,
+                                           ICMP_PING_TIMEOUT_MILLIS,
+                                           1, false);
+    if (result == WinPing::PING_FAIL) {
+      SetError(EINVAL);  // can't think of a better error ID
+      return -1;
+    } else if (result != WinPing::PING_TOO_LARGE) {
+      *mtu = PACKET_MAXIMUMS[level];
       return 0;
     }
-
-    return DoConnect(addr);
-  }
-
-  int DoConnect(const SocketAddress& connect_addr) {
-    if ((s_ == INVALID_SOCKET) &&
-        !Create(connect_addr.family(), SOCK_STREAM)) {
-      return SOCKET_ERROR;
-    }
-    sockaddr_storage addr_storage;
-    size_t len = connect_addr.ToSockAddrStorage(&addr_storage);
-    sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
-    int err = ::connect(s_, addr, static_cast<int>(len));
+  }
+
+  ASSERT(false);
+  return -1;
+#elif defined(WEBRTC_MAC)
+  // No simple way to do this on Mac OS X.
+  // SIOCGIFMTU would work if we knew which interface would be used, but
+  // figuring that out is pretty complicated. For now we'll return an error
+  // and let the caller pick a default MTU.
+  SetError(EINVAL);
+  return -1;
+#elif defined(WEBRTC_LINUX)
+  // Gets the path MTU.
+  int value;
+  socklen_t vlen = sizeof(value);
+  int err = getsockopt(s_, IPPROTO_IP, IP_MTU, &value, &vlen);
+  if (err < 0) {
     UpdateLastError();
-    if (err == 0) {
-      state_ = CS_CONNECTED;
-    } else if (IsBlockingError(GetError())) {
-      state_ = CS_CONNECTING;
-      enabled_events_ |= DE_CONNECT;
-    } else {
-      return SOCKET_ERROR;
-    }
-
-    enabled_events_ |= DE_READ | DE_WRITE;
-    return 0;
-  }
-
-  int GetError() const override {
-    CritScope cs(&crit_);
-    return error_;
-  }
-
-  void SetError(int error) override {
-    CritScope cs(&crit_);
-    error_ = error;
-  }
-
-  ConnState GetState() const override { return state_; }
-
-  int GetOption(Option opt, int* value) override {
-    int slevel;
-    int sopt;
-    if (TranslateOption(opt, &slevel, &sopt) == -1)
+    return err;
+  }
+
+  ASSERT((0 <= value) && (value <= 65536));
+  *mtu = value;
+  return 0;
+#elif defined(__native_client__)
+  // Most socket operations, including this, will fail in NaCl's sandbox.
+  error_ = EACCES;
+  return -1;
+#endif
+}
+
+
+SOCKET PhysicalSocket::DoAccept(SOCKET socket,
+                                sockaddr* addr,
+                                socklen_t* addrlen) {
+  return ::accept(socket, addr, addrlen);
+}
+
+void PhysicalSocket::OnResolveResult(AsyncResolverInterface* resolver) {
+  if (resolver != resolver_) {
+    return;
+  }
+
+  int error = resolver_->GetError();
+  if (error == 0) {
+    error = DoConnect(resolver_->address());
+  } else {
+    Close();
+  }
+
+  if (error) {
+    SetError(error);
+    SignalCloseEvent(this, error);
+  }
+}
+
+void PhysicalSocket::UpdateLastError() {
+  SetError(LAST_SYSTEM_ERROR);
+}
+
+void PhysicalSocket::MaybeRemapSendError() {
+#if defined(WEBRTC_MAC)
+  // https://developer.apple.com/library/mac/documentation/Darwin/
+  // Reference/ManPages/man2/sendto.2.html
+  // ENOBUFS - The output queue for a network interface is full.
+  // This generally indicates that the interface has stopped sending,
+  // but may be caused by transient congestion.
+  if (GetError() == ENOBUFS) {
+    SetError(EWOULDBLOCK);
+  }
+#endif
+}
+
+int PhysicalSocket::TranslateOption(Option opt, int* slevel, int* sopt) {
+  switch (opt) {
+    case OPT_DONTFRAGMENT:
+#if defined(WEBRTC_WIN)
+      *slevel = IPPROTO_IP;
+      *sopt = IP_DONTFRAGMENT;
+      break;
+#elif defined(WEBRTC_MAC) || defined(BSD) || defined(__native_client__)
+      LOG(LS_WARNING) << "Socket::OPT_DONTFRAGMENT not supported.";
       return -1;
-    socklen_t optlen = sizeof(*value);
-    int ret = ::getsockopt(s_, slevel, sopt, (SockOptArg)value, &optlen);
-    if (ret != -1 && opt == OPT_DONTFRAGMENT) {
-#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
-      *value = (*value != IP_PMTUDISC_DONT) ? 1 : 0;
-#endif
-    }
-    return ret;
-  }
-
-  int SetOption(Option opt, int value) override {
-    int slevel;
-    int sopt;
-    if (TranslateOption(opt, &slevel, &sopt) == -1)
+#elif defined(WEBRTC_POSIX)
+      *slevel = IPPROTO_IP;
+      *sopt = IP_MTU_DISCOVER;
+      break;
+#endif
+    case OPT_RCVBUF:
+      *slevel = SOL_SOCKET;
+      *sopt = SO_RCVBUF;
+      break;
+    case OPT_SNDBUF:
+      *slevel = SOL_SOCKET;
+      *sopt = SO_SNDBUF;
+      break;
+    case OPT_NODELAY:
+      *slevel = IPPROTO_TCP;
+      *sopt = TCP_NODELAY;
+      break;
+    case OPT_DSCP:
+      LOG(LS_WARNING) << "Socket::OPT_DSCP not supported.";
       return -1;
-    if (opt == OPT_DONTFRAGMENT) {
-#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
-      value = (value) ? IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
-#endif
-    }
-    return ::setsockopt(s_, slevel, sopt, (SockOptArg)&value, sizeof(value));
-  }
-
-  int Send(const void* pv, size_t cb) override {
-    int sent = ::send(s_, reinterpret_cast<const char *>(pv), (int)cb,
-#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
-        // Suppress SIGPIPE. Without this, attempting to send on a socket whose
-        // other end is closed will result in a SIGPIPE signal being raised to
-        // our process, which by default will terminate the process, which we
-        // don't want. By specifying this flag, we'll just get the error EPIPE
-        // instead and can handle the error gracefully.
-        MSG_NOSIGNAL
-#else
-        0
-#endif
-        );
-    UpdateLastError();
-    MaybeRemapSendError();
-    // We have seen minidumps where this may be false.
-    ASSERT(sent <= static_cast<int>(cb));
-    if ((sent < 0) && IsBlockingError(GetError())) {
-      enabled_events_ |= DE_WRITE;
-    }
-    return sent;
-  }
-
-  int SendTo(const void* buffer,
-             size_t length,
-             const SocketAddress& addr) override {
-    sockaddr_storage saddr;
-    size_t len = addr.ToSockAddrStorage(&saddr);
-    int sent = ::sendto(
-        s_, static_cast<const char *>(buffer), static_cast<int>(length),
-#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
-        // Suppress SIGPIPE. See above for explanation.
-        MSG_NOSIGNAL,
-#else
-        0,
-#endif
-        reinterpret_cast<sockaddr*>(&saddr), static_cast<int>(len));
-    UpdateLastError();
-    MaybeRemapSendError();
-    // We have seen minidumps where this may be false.
-    ASSERT(sent <= static_cast<int>(length));
-    if ((sent < 0) && IsBlockingError(GetError())) {
-      enabled_events_ |= DE_WRITE;
-    }
-    return sent;
-  }
-
-  int Recv(void* buffer, size_t length) override {
-    int received = ::recv(s_, static_cast<char*>(buffer),
-                          static_cast<int>(length), 0);
-    if ((received == 0) && (length != 0)) {
-      // Note: on graceful shutdown, recv can return 0.  In this case, we
-      // pretend it is blocking, and then signal close, so that simplifying
-      // assumptions can be made about Recv.
-      LOG(LS_WARNING) << "EOF from socket; deferring close event";
-      // Must turn this back on so that the select() loop will notice the close
-      // event.
-      enabled_events_ |= DE_READ;
-      SetError(EWOULDBLOCK);
-      return SOCKET_ERROR;
-    }
-    UpdateLastError();
-    int error = GetError();
-    bool success = (received >= 0) || IsBlockingError(error);
-    if (udp_ || success) {
-      enabled_events_ |= DE_READ;
-    }
-    if (!success) {
-      LOG_F(LS_VERBOSE) << "Error = " << error;
-    }
-    return received;
-  }
-
-  int RecvFrom(void* buffer, size_t length, SocketAddress* out_addr) override {
-    sockaddr_storage addr_storage;
-    socklen_t addr_len = sizeof(addr_storage);
-    sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
-    int received = ::recvfrom(s_, static_cast<char*>(buffer),
-                              static_cast<int>(length), 0, addr, &addr_len);
-    UpdateLastError();
-    if ((received >= 0) && (out_addr != NULL))
-      SocketAddressFromSockAddrStorage(addr_storage, out_addr);
-    int error = GetError();
-    bool success = (received >= 0) || IsBlockingError(error);
-    if (udp_ || success) {
-      enabled_events_ |= DE_READ;
-    }
-    if (!success) {
-      LOG_F(LS_VERBOSE) << "Error = " << error;
-    }
-    return received;
-  }
-
-  int Listen(int backlog) override {
-    int err = ::listen(s_, backlog);
-    UpdateLastError();
-    if (err == 0) {
-      state_ = CS_CONNECTING;
-      enabled_events_ |= DE_ACCEPT;
-#if !defined(NDEBUG)
-      dbg_addr_ = "Listening @ ";
-      dbg_addr_.append(GetLocalAddress().ToString());
-#endif
-    }
-    return err;
-  }
-
-  AsyncSocket* Accept(SocketAddress* out_addr) override {
-    sockaddr_storage addr_storage;
-    socklen_t addr_len = sizeof(addr_storage);
-    sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
-    SOCKET s = ::accept(s_, addr, &addr_len);
-    UpdateLastError();
-    if (s == INVALID_SOCKET)
-      return NULL;
-    enabled_events_ |= DE_ACCEPT;
-    if (out_addr != NULL)
-      SocketAddressFromSockAddrStorage(addr_storage, out_addr);
-    return ss_->WrapSocket(s);
-  }
-
-  int Close() override {
-    if (s_ == INVALID_SOCKET)
-      return 0;
-    int err = ::closesocket(s_);
-    UpdateLastError();
-    s_ = INVALID_SOCKET;
-    state_ = CS_CLOSED;
-    enabled_events_ = 0;
-    if (resolver_) {
-      resolver_->Destroy(false);
-      resolver_ = NULL;
-    }
-    return err;
-  }
-
-  int EstimateMTU(uint16_t* mtu) override {
-    SocketAddress addr = GetRemoteAddress();
-    if (addr.IsAnyIP()) {
-      SetError(ENOTCONN);
+    case OPT_RTP_SENDTIME_EXTN_ID:
+      return -1;  // No logging is necessary as this not a OS socket option.
+    default:
+      ASSERT(false);
       return -1;
-    }
-
-#if defined(WEBRTC_WIN)
-    // Gets the interface MTU (TTL=1) for the interface used to reach |addr|.
-    WinPing ping;
-    if (!ping.IsValid()) {
-      SetError(EINVAL);  // can't think of a better error ID
-      return -1;
-    }
-    int header_size = ICMP_HEADER_SIZE;
-    if (addr.family() == AF_INET6) {
-      header_size += IPV6_HEADER_SIZE;
-    } else if (addr.family() == AF_INET) {
-      header_size += IP_HEADER_SIZE;
-    }
-
-    for (int level = 0; PACKET_MAXIMUMS[level + 1] > 0; ++level) {
-      int32_t size = PACKET_MAXIMUMS[level] - header_size;
-      WinPing::PingResult result = ping.Ping(addr.ipaddr(), size,
-                                             ICMP_PING_TIMEOUT_MILLIS,
-                                             1, false);
-      if (result == WinPing::PING_FAIL) {
-        SetError(EINVAL);  // can't think of a better error ID
-        return -1;
-      } else if (result != WinPing::PING_TOO_LARGE) {
-        *mtu = PACKET_MAXIMUMS[level];
-        return 0;
-      }
-    }
-
-    ASSERT(false);
-    return -1;
-#elif defined(WEBRTC_MAC)
-    // No simple way to do this on Mac OS X.
-    // SIOCGIFMTU would work if we knew which interface would be used, but
-    // figuring that out is pretty complicated. For now we'll return an error
-    // and let the caller pick a default MTU.
-    SetError(EINVAL);
-    return -1;
-#elif defined(WEBRTC_LINUX)
-    // Gets the path MTU.
-    int value;
-    socklen_t vlen = sizeof(value);
-    int err = getsockopt(s_, IPPROTO_IP, IP_MTU, &value, &vlen);
-    if (err < 0) {
-      UpdateLastError();
-      return err;
-    }
-
-    ASSERT((0 <= value) && (value <= 65536));
-    *mtu = value;
-    return 0;
-#elif defined(__native_client__)
-    // Most socket operations, including this, will fail in NaCl's sandbox.
-    error_ = EACCES;
-    return -1;
-#endif
-  }
-
-  SocketServer* socketserver() { return ss_; }
-
- protected:
-  void OnResolveResult(AsyncResolverInterface* resolver) {
-    if (resolver != resolver_) {
-      return;
-    }
-
-    int error = resolver_->GetError();
-    if (error == 0) {
-      error = DoConnect(resolver_->address());
-    } else {
-      Close();
-    }
-
-    if (error) {
-      SetError(error);
-      SignalCloseEvent(this, error);
-    }
-  }
-
-  void UpdateLastError() {
-    SetError(LAST_SYSTEM_ERROR);
-  }
-
-  void MaybeRemapSendError() {
-#if defined(WEBRTC_MAC)
-    // https://developer.apple.com/library/mac/documentation/Darwin/
-    // Reference/ManPages/man2/sendto.2.html
-    // ENOBUFS - The output queue for a network interface is full.
-    // This generally indicates that the interface has stopped sending,
-    // but may be caused by transient congestion.
-    if (GetError() == ENOBUFS) {
-      SetError(EWOULDBLOCK);
-    }
-#endif
-  }
-
-  static int TranslateOption(Option opt, int* slevel, int* sopt) {
-    switch (opt) {
-      case OPT_DONTFRAGMENT:
-#if defined(WEBRTC_WIN)
-        *slevel = IPPROTO_IP;
-        *sopt = IP_DONTFRAGMENT;
-        break;
-#elif defined(WEBRTC_MAC) || defined(BSD) || defined(__native_client__)
-        LOG(LS_WARNING) << "Socket::OPT_DONTFRAGMENT not supported.";
-        return -1;
-#elif defined(WEBRTC_POSIX)
-        *slevel = IPPROTO_IP;
-        *sopt = IP_MTU_DISCOVER;
-        break;
-#endif
-      case OPT_RCVBUF:
-        *slevel = SOL_SOCKET;
-        *sopt = SO_RCVBUF;
-        break;
-      case OPT_SNDBUF:
-        *slevel = SOL_SOCKET;
-        *sopt = SO_SNDBUF;
-        break;
-      case OPT_NODELAY:
-        *slevel = IPPROTO_TCP;
-        *sopt = TCP_NODELAY;
-        break;
-      case OPT_DSCP:
-        LOG(LS_WARNING) << "Socket::OPT_DSCP not supported.";
-        return -1;
-      case OPT_RTP_SENDTIME_EXTN_ID:
-        return -1;  // No logging is necessary as this not a OS socket option.
-      default:
-        ASSERT(false);
-        return -1;
-    }
-    return 0;
-  }
-
-  PhysicalSocketServer* ss_;
-  SOCKET s_;
-  uint8_t enabled_events_;
-  bool udp_;
-  int error_;
-  // Protects |error_| that is accessed from different threads.
-  mutable CriticalSection crit_;
-  ConnState state_;
-  AsyncResolver* resolver_;
-
-#if !defined(NDEBUG)
-  std::string dbg_addr_;
-#endif
-};
+  }
+  return 0;
+}
 
 #if defined(WEBRTC_POSIX)
 class EventDispatcher : public Dispatcher {
  public:
   EventDispatcher(PhysicalSocketServer* ss) : ss_(ss), fSignaled_(false) {
     if (pipe(afd_) < 0)
       LOG(LERROR) << "pipe failed";
     ss_->Add(this);
   }
 
@@ skipping 217 matching lines @@
   }
 
  private:
   typedef std::map<int, void (*)(int)> HandlerMap;
 
   HandlerMap handlers_;
   // Our owner.
   PhysicalSocketServer *owner_;
 };
 
-class SocketDispatcher : public Dispatcher, public PhysicalSocket {
- public:
-  explicit SocketDispatcher(PhysicalSocketServer *ss) : PhysicalSocket(ss) {
-  }
-  SocketDispatcher(SOCKET s, PhysicalSocketServer *ss) : PhysicalSocket(ss, s) {
-  }
+SocketDispatcher::SocketDispatcher(PhysicalSocketServer *ss)
+  : PhysicalSocket(ss) {
+}
 
-  ~SocketDispatcher() override {
-    Close();
-  }
+SocketDispatcher::SocketDispatcher(SOCKET s, PhysicalSocketServer *ss)
+  : PhysicalSocket(ss, s) {
+}
 
-  bool Initialize() {
-    ss_->Add(this);
-    fcntl(s_, F_SETFL, fcntl(s_, F_GETFL, 0) | O_NONBLOCK);
+SocketDispatcher::~SocketDispatcher() {
+  Close();
+}
+
+bool SocketDispatcher::Initialize() {
+  ss_->Add(this);
+  fcntl(s_, F_SETFL, fcntl(s_, F_GETFL, 0) | O_NONBLOCK);
+  return true;
+}
+
+bool SocketDispatcher::Create(int type) {
+  return Create(AF_INET, type);
+}
+
+bool SocketDispatcher::Create(int family, int type) {
+  // Change the socket to be non-blocking.
+  if (!PhysicalSocket::Create(family, type))
+    return false;
+
+  return Initialize();
+}
+
+bool SocketDispatcher::IsDescriptorClosed() {
+  // We don't have a reliable way of distinguishing end-of-stream
+  // from readability.  So test on each readable call.  Is this
+  // inefficient?  Probably.
+  char ch;
+  ssize_t res = ::recv(s_, &ch, 1, MSG_PEEK);
+  if (res > 0) {
+    // Data available, so not closed.
+    return false;
+  } else if (res == 0) {
+    // EOF, so closed.
     return true;
-  }
-
-  virtual bool Create(int type) {
-    return Create(AF_INET, type);
-  }
-
-  bool Create(int family, int type) override {
-    // Change the socket to be non-blocking.
-    if (!PhysicalSocket::Create(family, type))
-      return false;
-
-    return Initialize();
-  }
-
-  int GetDescriptor() override { return s_; }
-
-  bool IsDescriptorClosed() override {
-    // We don't have a reliable way of distinguishing end-of-stream
-    // from readability.  So test on each readable call.  Is this
-    // inefficient?  Probably.
-    char ch;
-    ssize_t res = ::recv(s_, &ch, 1, MSG_PEEK);
-    if (res > 0) {
-      // Data available, so not closed.
-      return false;
-    } else if (res == 0) {
-      // EOF, so closed.
-      return true;
-    } else {  // error
-      switch (errno) {
-        // Returned if we've already closed s_.
-        case EBADF:
-        // Returned during ungraceful peer shutdown.
-        case ECONNRESET:
-          return true;
-        default:
-          // Assume that all other errors are just blocking errors, meaning the
-          // connection is still good but we just can't read from it right now.
-          // This should only happen when connecting (and at most once), because
-          // in all other cases this function is only called if the file
-          // descriptor is already known to be in the readable state. However,
-          // it's not necessary a problem if we spuriously interpret a
-          // "connection lost"-type error as a blocking error, because typically
-          // the next recv() will get EOF, so we'll still eventually notice that
-          // the socket is closed.
-          LOG_ERR(LS_WARNING) << "Assuming benign blocking error";
-          return false;
-      }
+  } else {  // error
+    switch (errno) {
+      // Returned if we've already closed s_.
+      case EBADF:
+      // Returned during ungraceful peer shutdown.
+      case ECONNRESET:
+        return true;
+      default:
+        // Assume that all other errors are just blocking errors, meaning the
+        // connection is still good but we just can't read from it right now.
+        // This should only happen when connecting (and at most once), because
+        // in all other cases this function is only called if the file
+        // descriptor is already known to be in the readable state. However,
+        // it's not necessary a problem if we spuriously interpret a
+        // "connection lost"-type error as a blocking error, because typically
+        // the next recv() will get EOF, so we'll still eventually notice that
+        // the socket is closed.
+        LOG_ERR(LS_WARNING) << "Assuming benign blocking error";
+        return false;
     }
   }
+}
 
-  uint32_t GetRequestedEvents() override { return enabled_events_; }
+void SocketDispatcher::OnPreEvent(uint32_t ff) {
+  if ((ff & DE_CONNECT) != 0)
+    state_ = CS_CONNECTED;
+  if ((ff & DE_CLOSE) != 0)
+    state_ = CS_CLOSED;
+}
 
-  void OnPreEvent(uint32_t ff) override {
-    if ((ff & DE_CONNECT) != 0)
-      state_ = CS_CONNECTED;
-    if ((ff & DE_CLOSE) != 0)
-      state_ = CS_CLOSED;
+void SocketDispatcher::OnEvent(uint32_t ff, int err) {
+  // Make sure we deliver connect/accept first. Otherwise, consumers may see
+  // something like a READ followed by a CONNECT, which would be odd.
+  if ((ff & DE_CONNECT) != 0) {
+    enabled_events_ &= ~DE_CONNECT;
+    SignalConnectEvent(this);
   }
+  if ((ff & DE_ACCEPT) != 0) {
+    enabled_events_ &= ~DE_ACCEPT;
+    SignalReadEvent(this);
+  }
+  if ((ff & DE_READ) != 0) {
+    enabled_events_ &= ~DE_READ;
+    SignalReadEvent(this);
+  }
+  if ((ff & DE_WRITE) != 0) {
+    enabled_events_ &= ~DE_WRITE;
+    SignalWriteEvent(this);
+  }
+  if ((ff & DE_CLOSE) != 0) {
+    // The socket is now dead to us, so stop checking it.
+    enabled_events_ = 0;
+    SignalCloseEvent(this, err);
+  }
+}
 
-  void OnEvent(uint32_t ff, int err) override {
-    // Make sure we deliver connect/accept first. Otherwise, consumers may see
-    // something like a READ followed by a CONNECT, which would be odd.
-    if ((ff & DE_CONNECT) != 0) {
-      enabled_events_ &= ~DE_CONNECT;
-      SignalConnectEvent(this);
-    }
-    if ((ff & DE_ACCEPT) != 0) {
-      enabled_events_ &= ~DE_ACCEPT;
-      SignalReadEvent(this);
-    }
-    if ((ff & DE_READ) != 0) {
-      enabled_events_ &= ~DE_READ;
-      SignalReadEvent(this);
-    }
-    if ((ff & DE_WRITE) != 0) {
-      enabled_events_ &= ~DE_WRITE;
-      SignalWriteEvent(this);
-    }
-    if ((ff & DE_CLOSE) != 0) {
-      // The socket is now dead to us, so stop checking it.
-      enabled_events_ = 0;
-      SignalCloseEvent(this, err);
-    }
-  }
+int SocketDispatcher::Close() {
+  if (s_ == INVALID_SOCKET)
+    return 0;
 
-  int Close() override {
-    if (s_ == INVALID_SOCKET)
-      return 0;
-
-    ss_->Remove(this);
-    return PhysicalSocket::Close();
-  }
-};
+  ss_->Remove(this);
+  return PhysicalSocket::Close();
+}
 
 class FileDispatcher: public Dispatcher, public AsyncFile {
  public:
   FileDispatcher(int fd, PhysicalSocketServer *ss) : ss_(ss), fd_(fd) {
     set_readable(true);
 
     ss_->Add(this);
 
     fcntl(fd_, F_SETFL, fcntl(fd_, F_GETFL, 0) | O_NONBLOCK);
   }
@@ skipping 270 matching lines @@
 Socket* PhysicalSocketServer::CreateSocket(int type) {
   return CreateSocket(AF_INET, type);
 }
 
 Socket* PhysicalSocketServer::CreateSocket(int family, int type) {
   PhysicalSocket* socket = new PhysicalSocket(this);
   if (socket->Create(family, type)) {
     return socket;
   } else {
     delete socket;
-    return 0;
+    return nullptr;
   }
 }
 
 AsyncSocket* PhysicalSocketServer::CreateAsyncSocket(int type) {
   return CreateAsyncSocket(AF_INET, type);
 }
 
 AsyncSocket* PhysicalSocketServer::CreateAsyncSocket(int family, int type) {
   SocketDispatcher* dispatcher = new SocketDispatcher(this);
   if (dispatcher->Create(family, type)) {
     return dispatcher;
   } else {
     delete dispatcher;
-    return 0;
+    return nullptr;
   }
 }
 
 AsyncSocket* PhysicalSocketServer::WrapSocket(SOCKET s) {
   SocketDispatcher* dispatcher = new SocketDispatcher(s, this);
   if (dispatcher->Initialize()) {
     return dispatcher;
   } else {
     delete dispatcher;
-    return 0;
+    return nullptr;
   }
 }
 
 void PhysicalSocketServer::Add(Dispatcher *pdispatcher) {
   CritScope cs(&crit_);
   // Prevent duplicates. This can cause dead dispatchers to stick around.
   DispatcherList::iterator pos = std::find(dispatchers_.begin(),
                                            dispatchers_.end(),
                                            pdispatcher);
   if (pos != dispatchers_.end())
@@ skipping 400 matching lines @@
        break;
     }
   }
 
   // Done
   return true;
 }
 #endif  // WEBRTC_WIN 
 
 }  // namespace rtc