Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1144 insertions, 0 deletions

diff --git a/third_party/libwebrtc/rtc_base/socket_unittest.cc b/third_party/libwebrtc/rtc_base/socket_unittest.cc
new file mode 100644
index 0000000000..0a41a776ac
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/socket_unittest.cc
@@ -0,0 +1,1144 @@
+/*
+ *  Copyright 2007 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.
+ */
+
+#include "rtc_base/socket.h"
+
+#include <errno.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+
+#include "absl/memory/memory.h"
+#include "absl/strings/string_view.h"
+#include "rtc_base/arraysize.h"
+#include "rtc_base/async_packet_socket.h"
+#include "rtc_base/async_udp_socket.h"
+#include "rtc_base/buffer.h"
+#include "rtc_base/gunit.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/net_helpers.h"
+#include "rtc_base/net_test_helpers.h"
+#include "rtc_base/socket_address.h"
+#include "rtc_base/socket_server.h"
+#include "rtc_base/socket_unittest.h"
+#include "rtc_base/test_client.h"
+#include "rtc_base/test_utils.h"
+#include "rtc_base/third_party/sigslot/sigslot.h"
+#include "rtc_base/thread.h"
+#include "rtc_base/time_utils.h"
+
+namespace rtc {
+
+using webrtc::testing::SSE_CLOSE;
+using webrtc::testing::SSE_ERROR;
+using webrtc::testing::SSE_OPEN;
+using webrtc::testing::SSE_READ;
+using webrtc::testing::SSE_WRITE;
+using webrtc::testing::StreamSink;
+
+#define MAYBE_SKIP_IPV6                        \
+  if (!HasIPv6Enabled()) {                     \
+    RTC_LOG(LS_INFO) << "No IPv6... skipping"; \
+    return;                                    \
+  }
+
+// Data size to be used in TcpInternal tests.
+static const size_t kTcpInternalDataSize = 1024 * 1024;  // bytes
+
+void SocketTest::TestConnectIPv4() {
+  ConnectInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestConnectIPv6() {
+  MAYBE_SKIP_IPV6;
+  ConnectInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestConnectWithDnsLookupIPv4() {
+  ConnectWithDnsLookupInternal(kIPv4Loopback, "localhost");
+}
+
+void SocketTest::TestConnectWithDnsLookupIPv6() {
+  // TODO: Enable this when DNS resolution supports IPv6.
+  RTC_LOG(LS_INFO) << "Skipping IPv6 DNS test";
+  // ConnectWithDnsLookupInternal(kIPv6Loopback, "localhost6");
+}
+
+void SocketTest::TestConnectFailIPv4() {
+  ConnectFailInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestConnectFailIPv6() {
+  MAYBE_SKIP_IPV6;
+  ConnectFailInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestConnectWithDnsLookupFailIPv4() {
+  ConnectWithDnsLookupFailInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestConnectWithDnsLookupFailIPv6() {
+  MAYBE_SKIP_IPV6;
+  ConnectWithDnsLookupFailInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestConnectWithClosedSocketIPv4() {
+  ConnectWithClosedSocketInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestConnectWithClosedSocketIPv6() {
+  MAYBE_SKIP_IPV6;
+  ConnectWithClosedSocketInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestConnectWhileNotClosedIPv4() {
+  ConnectWhileNotClosedInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestConnectWhileNotClosedIPv6() {
+  MAYBE_SKIP_IPV6;
+  ConnectWhileNotClosedInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestServerCloseDuringConnectIPv4() {
+  ServerCloseDuringConnectInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestServerCloseDuringConnectIPv6() {
+  MAYBE_SKIP_IPV6;
+  ServerCloseDuringConnectInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestClientCloseDuringConnectIPv4() {
+  ClientCloseDuringConnectInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestClientCloseDuringConnectIPv6() {
+  MAYBE_SKIP_IPV6;
+  ClientCloseDuringConnectInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestServerCloseIPv4() {
+  ServerCloseInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestServerCloseIPv6() {
+  MAYBE_SKIP_IPV6;
+  ServerCloseInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestCloseInClosedCallbackIPv4() {
+  CloseInClosedCallbackInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestCloseInClosedCallbackIPv6() {
+  MAYBE_SKIP_IPV6;
+  CloseInClosedCallbackInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestDeleteInReadCallbackIPv4() {
+  DeleteInReadCallbackInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestDeleteInReadCallbackIPv6() {
+  MAYBE_SKIP_IPV6;
+  DeleteInReadCallbackInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestSocketServerWaitIPv4() {
+  SocketServerWaitInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestSocketServerWaitIPv6() {
+  MAYBE_SKIP_IPV6;
+  SocketServerWaitInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestTcpIPv4() {
+  TcpInternal(kIPv4Loopback, kTcpInternalDataSize, -1);
+}
+
+void SocketTest::TestTcpIPv6() {
+  MAYBE_SKIP_IPV6;
+  TcpInternal(kIPv6Loopback, kTcpInternalDataSize, -1);
+}
+
+void SocketTest::TestSingleFlowControlCallbackIPv4() {
+  SingleFlowControlCallbackInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestSingleFlowControlCallbackIPv6() {
+  MAYBE_SKIP_IPV6;
+  SingleFlowControlCallbackInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestUdpIPv4() {
+  UdpInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestUdpIPv6() {
+  MAYBE_SKIP_IPV6;
+  UdpInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestUdpReadyToSendIPv4() {
+#if !defined(WEBRTC_MAC)
+  // TODO(ronghuawu): Enable this test on mac/ios.
+  UdpReadyToSend(kIPv4Loopback);
+#endif
+}
+
+void SocketTest::TestUdpReadyToSendIPv6() {
+#if defined(WEBRTC_WIN)
+  // TODO(ronghuawu): Enable this test (currently flakey) on mac and linux.
+  MAYBE_SKIP_IPV6;
+  UdpReadyToSend(kIPv6Loopback);
+#endif
+}
+
+void SocketTest::TestGetSetOptionsIPv4() {
+  GetSetOptionsInternal(kIPv4Loopback);
+}
+
+void SocketTest::TestGetSetOptionsIPv6() {
+  MAYBE_SKIP_IPV6;
+  GetSetOptionsInternal(kIPv6Loopback);
+}
+
+void SocketTest::TestSocketRecvTimestampIPv4() {
+  SocketRecvTimestamp(kIPv4Loopback);
+}
+
+void SocketTest::TestSocketRecvTimestampIPv6() {
+  MAYBE_SKIP_IPV6;
+  SocketRecvTimestamp(kIPv6Loopback);
+}
+
+void SocketTest::TestUdpSocketRecvTimestampUseRtcEpochIPv4() {
+  UdpSocketRecvTimestampUseRtcEpoch(kIPv4Loopback);
+}
+
+void SocketTest::TestUdpSocketRecvTimestampUseRtcEpochIPv6() {
+  MAYBE_SKIP_IPV6;
+  UdpSocketRecvTimestampUseRtcEpoch(kIPv6Loopback);
+}
+
+// For unbound sockets, GetLocalAddress / GetRemoteAddress return AF_UNSPEC
+// values on Windows, but an empty address of the same family on Linux/MacOS X.
+bool IsUnspecOrEmptyIP(const IPAddress& address) {
+#if !defined(WEBRTC_WIN)
+  return IPIsAny(address);
+#else
+  return address.family() == AF_UNSPEC;
+#endif
+}
+
+void SocketTest::ConnectInternal(const IPAddress& loopback) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+  EXPECT_EQ(Socket::CS_CLOSED, client->GetState());
+  EXPECT_TRUE(IsUnspecOrEmptyIP(client->GetLocalAddress().ipaddr()));
+
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+  EXPECT_EQ(Socket::CS_CONNECTING, server->GetState());
+
+  // Ensure no pending server connections, since we haven't done anything yet.
+  EXPECT_FALSE(sink.Check(server.get(), SSE_READ));
+  EXPECT_TRUE(nullptr == server->Accept(&accept_addr));
+  EXPECT_TRUE(accept_addr.IsNil());
+
+  // Attempt connect to listening socket.
+  EXPECT_EQ(0, client->Connect(server->GetLocalAddress()));
+  EXPECT_FALSE(client->GetLocalAddress().IsNil());
+  EXPECT_NE(server->GetLocalAddress(), client->GetLocalAddress());
+
+  // Client is connecting, outcome not yet determined.
+  EXPECT_EQ(Socket::CS_CONNECTING, client->GetState());
+  EXPECT_FALSE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+
+  // Server has pending connection, accept it.
+  EXPECT_TRUE_WAIT((sink.Check(server.get(), SSE_READ)), kTimeout);
+  std::unique_ptr<Socket> accepted(server->Accept(&accept_addr));
+  ASSERT_TRUE(accepted);
+  EXPECT_FALSE(accept_addr.IsNil());
+  EXPECT_EQ(accepted->GetRemoteAddress(), accept_addr);
+
+  // Connected from server perspective, check the addresses are correct.
+  EXPECT_EQ(Socket::CS_CONNECTED, accepted->GetState());
+  EXPECT_EQ(server->GetLocalAddress(), accepted->GetLocalAddress());
+  EXPECT_EQ(client->GetLocalAddress(), accepted->GetRemoteAddress());
+
+  // Connected from client perspective, check the addresses are correct.
+  EXPECT_EQ_WAIT(Socket::CS_CONNECTED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+  EXPECT_EQ(client->GetRemoteAddress(), server->GetLocalAddress());
+  EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
+}
+
+void SocketTest::ConnectWithDnsLookupInternal(const IPAddress& loopback,
+                                              absl::string_view host) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  // Attempt connect to listening socket.
+  SocketAddress dns_addr(server->GetLocalAddress());
+  dns_addr.SetIP(host);
+  EXPECT_EQ(0, client->Connect(dns_addr));
+  // TODO: Bind when doing DNS lookup.
+  // EXPECT_NE(kEmptyAddr, client->GetLocalAddress());  // Implicit Bind
+
+  // Client is connecting, outcome not yet determined.
+  EXPECT_EQ(Socket::CS_CONNECTING, client->GetState());
+  EXPECT_FALSE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+
+  // Server has pending connection, accept it.
+  EXPECT_TRUE_WAIT((sink.Check(server.get(), SSE_READ)), kTimeout);
+  std::unique_ptr<Socket> accepted(server->Accept(&accept_addr));
+  ASSERT_TRUE(accepted);
+  EXPECT_FALSE(accept_addr.IsNil());
+  EXPECT_EQ(accepted->GetRemoteAddress(), accept_addr);
+
+  // Connected from server perspective, check the addresses are correct.
+  EXPECT_EQ(Socket::CS_CONNECTED, accepted->GetState());
+  EXPECT_EQ(server->GetLocalAddress(), accepted->GetLocalAddress());
+  EXPECT_EQ(client->GetLocalAddress(), accepted->GetRemoteAddress());
+
+  // Connected from client perspective, check the addresses are correct.
+  EXPECT_EQ_WAIT(Socket::CS_CONNECTED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+  EXPECT_EQ(client->GetRemoteAddress(), server->GetLocalAddress());
+  EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
+}
+
+void SocketTest::ConnectFailInternal(const IPAddress& loopback) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+
+  // Create server, but don't listen yet.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+
+  // Attempt connect to a non-existent socket.
+  // We don't connect to the server socket created above, since on
+  // MacOS it takes about 75 seconds to get back an error!
+  SocketAddress bogus_addr(loopback, 65535);
+  EXPECT_EQ(0, client->Connect(bogus_addr));
+
+  // Wait for connection to fail (ECONNREFUSED).
+  EXPECT_EQ_WAIT(Socket::CS_CLOSED, client->GetState(), kTimeout);
+  EXPECT_FALSE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_TRUE(sink.Check(client.get(), SSE_ERROR));
+  EXPECT_TRUE(client->GetRemoteAddress().IsNil());
+
+  // Should be no pending server connections.
+  EXPECT_FALSE(sink.Check(server.get(), SSE_READ));
+  EXPECT_TRUE(nullptr == server->Accept(&accept_addr));
+  EXPECT_EQ(IPAddress(), accept_addr.ipaddr());
+}
+
+void SocketTest::ConnectWithDnsLookupFailInternal(const IPAddress& loopback) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+
+  // Create server, but don't listen yet.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+
+  // Attempt connect to a non-existent host.
+  // We don't connect to the server socket created above, since on
+  // MacOS it takes about 75 seconds to get back an error!
+  SocketAddress bogus_dns_addr("not-a-real-hostname", 65535);
+  EXPECT_EQ(0, client->Connect(bogus_dns_addr));
+
+  // Wait for connection to fail (EHOSTNOTFOUND).
+  bool dns_lookup_finished = false;
+  WAIT_(client->GetState() == Socket::CS_CLOSED, kTimeout, dns_lookup_finished);
+  if (!dns_lookup_finished) {
+    RTC_LOG(LS_WARNING) << "Skipping test; DNS resolution took longer than 5 "
+                           "seconds.";
+    return;
+  }
+
+  EXPECT_EQ_WAIT(Socket::CS_CLOSED, client->GetState(), kTimeout);
+  EXPECT_FALSE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_TRUE(sink.Check(client.get(), SSE_ERROR));
+  EXPECT_TRUE(client->GetRemoteAddress().IsNil());
+  // Should be no pending server connections.
+  EXPECT_FALSE(sink.Check(server.get(), SSE_READ));
+  EXPECT_TRUE(nullptr == server->Accept(&accept_addr));
+  EXPECT_TRUE(accept_addr.IsNil());
+}
+
+void SocketTest::ConnectWithClosedSocketInternal(const IPAddress& loopback) {
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  // Create a client and put in to CS_CLOSED state.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  EXPECT_EQ(0, client->Close());
+  EXPECT_EQ(Socket::CS_CLOSED, client->GetState());
+
+  // Connect() should reinitialize the socket, and put it in to CS_CONNECTING.
+  EXPECT_EQ(0, client->Connect(SocketAddress(server->GetLocalAddress())));
+  EXPECT_EQ(Socket::CS_CONNECTING, client->GetState());
+}
+
+void SocketTest::ConnectWhileNotClosedInternal(const IPAddress& loopback) {
+  // Create server and listen.
+  StreamSink sink;
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+  // Create client, connect.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  EXPECT_EQ(0, client->Connect(SocketAddress(server->GetLocalAddress())));
+  EXPECT_EQ(Socket::CS_CONNECTING, client->GetState());
+  // Try to connect again. Should fail, but not interfere with original attempt.
+  EXPECT_EQ(SOCKET_ERROR,
+            client->Connect(SocketAddress(server->GetLocalAddress())));
+
+  // Accept the original connection.
+  SocketAddress accept_addr;
+  EXPECT_TRUE_WAIT((sink.Check(server.get(), SSE_READ)), kTimeout);
+  std::unique_ptr<Socket> accepted(server->Accept(&accept_addr));
+  ASSERT_TRUE(accepted);
+  EXPECT_FALSE(accept_addr.IsNil());
+
+  // Check the states and addresses.
+  EXPECT_EQ(Socket::CS_CONNECTED, accepted->GetState());
+  EXPECT_EQ(server->GetLocalAddress(), accepted->GetLocalAddress());
+  EXPECT_EQ(client->GetLocalAddress(), accepted->GetRemoteAddress());
+  EXPECT_EQ_WAIT(Socket::CS_CONNECTED, client->GetState(), kTimeout);
+  EXPECT_EQ(client->GetRemoteAddress(), server->GetLocalAddress());
+  EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
+
+  // Try to connect again, to an unresolved hostname.
+  // Shouldn't break anything.
+  EXPECT_EQ(SOCKET_ERROR, client->Connect(SocketAddress(
+                              "localhost", server->GetLocalAddress().port())));
+  EXPECT_EQ(Socket::CS_CONNECTED, accepted->GetState());
+  EXPECT_EQ(Socket::CS_CONNECTED, client->GetState());
+  EXPECT_EQ(client->GetRemoteAddress(), server->GetLocalAddress());
+  EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
+}
+
+void SocketTest::ServerCloseDuringConnectInternal(const IPAddress& loopback) {
+  StreamSink sink;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  // Attempt connect to listening socket.
+  EXPECT_EQ(0, client->Connect(server->GetLocalAddress()));
+
+  // Close down the server while the socket is in the accept queue.
+  EXPECT_TRUE_WAIT(sink.Check(server.get(), SSE_READ), kTimeout);
+  server->Close();
+
+  // This should fail the connection for the client. Clean up.
+  EXPECT_EQ_WAIT(Socket::CS_CLOSED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_ERROR));
+  client->Close();
+}
+
+void SocketTest::ClientCloseDuringConnectInternal(const IPAddress& loopback) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  // Attempt connect to listening socket.
+  EXPECT_EQ(0, client->Connect(server->GetLocalAddress()));
+
+  // Close down the client while the socket is in the accept queue.
+  EXPECT_TRUE_WAIT(sink.Check(server.get(), SSE_READ), kTimeout);
+  client->Close();
+
+  // The connection should still be able to be accepted.
+  std::unique_ptr<Socket> accepted(server->Accept(&accept_addr));
+  ASSERT_TRUE(accepted);
+  sink.Monitor(accepted.get());
+  EXPECT_EQ(Socket::CS_CONNECTED, accepted->GetState());
+
+  // The accepted socket should then close (possibly with err, timing-related)
+  EXPECT_EQ_WAIT(Socket::CS_CLOSED, accepted->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(accepted.get(), SSE_CLOSE) ||
+              sink.Check(accepted.get(), SSE_ERROR));
+
+  // The client should not get a close event.
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+}
+
+void SocketTest::ServerCloseInternal(const IPAddress& loopback) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  // Attempt connection.
+  EXPECT_EQ(0, client->Connect(server->GetLocalAddress()));
+
+  // Accept connection.
+  EXPECT_TRUE_WAIT((sink.Check(server.get(), SSE_READ)), kTimeout);
+  std::unique_ptr<Socket> accepted(server->Accept(&accept_addr));
+  ASSERT_TRUE(accepted);
+  sink.Monitor(accepted.get());
+
+  // Both sides are now connected.
+  EXPECT_EQ_WAIT(Socket::CS_CONNECTED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
+  EXPECT_EQ(accepted->GetRemoteAddress(), client->GetLocalAddress());
+
+  // Send data to the client, and then close the connection.
+  EXPECT_EQ(1, accepted->Send("a", 1));
+  accepted->Close();
+  EXPECT_EQ(Socket::CS_CLOSED, accepted->GetState());
+
+  // Expect that the client is notified, and has not yet closed.
+  EXPECT_TRUE_WAIT(sink.Check(client.get(), SSE_READ), kTimeout);
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+  EXPECT_EQ(Socket::CS_CONNECTED, client->GetState());
+
+  // Ensure the data can be read.
+  char buffer[10];
+  EXPECT_EQ(1, client->Recv(buffer, sizeof(buffer), nullptr));
+  EXPECT_EQ('a', buffer[0]);
+
+  // Now we should close, but the remote address will remain.
+  EXPECT_EQ_WAIT(Socket::CS_CLOSED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_CLOSE));
+  EXPECT_FALSE(client->GetRemoteAddress().IsAnyIP());
+
+  // The closer should not get a close signal.
+  EXPECT_FALSE(sink.Check(accepted.get(), SSE_CLOSE));
+  EXPECT_TRUE(accepted->GetRemoteAddress().IsNil());
+
+  // And the closee should only get a single signal.
+  Thread::Current()->ProcessMessages(0);
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+
+  // Close down the client and ensure all is good.
+  client->Close();
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+  EXPECT_TRUE(client->GetRemoteAddress().IsNil());
+}
+
+class SocketCloser : public sigslot::has_slots<> {
+ public:
+  void OnClose(Socket* socket, int error) {
+    socket->Close();  // Deleting here would blow up the vector of handlers
+                      // for the socket's signal.
+  }
+};
+
+void SocketTest::CloseInClosedCallbackInternal(const IPAddress& loopback) {
+  StreamSink sink;
+  SocketCloser closer;
+  SocketAddress accept_addr;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+  client->SignalCloseEvent.connect(&closer, &SocketCloser::OnClose);
+
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  // Attempt connection.
+  EXPECT_EQ(0, client->Connect(server->GetLocalAddress()));
+
+  // Accept connection.
+  EXPECT_TRUE_WAIT((sink.Check(server.get(), SSE_READ)), kTimeout);
+  std::unique_ptr<Socket> accepted(server->Accept(&accept_addr));
+  ASSERT_TRUE(accepted);
+  sink.Monitor(accepted.get());
+
+  // Both sides are now connected.
+  EXPECT_EQ_WAIT(Socket::CS_CONNECTED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
+  EXPECT_EQ(accepted->GetRemoteAddress(), client->GetLocalAddress());
+
+  // Send data to the client, and then close the connection.
+  accepted->Close();
+  EXPECT_EQ(Socket::CS_CLOSED, accepted->GetState());
+
+  // Expect that the client is notified, and has not yet closed.
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+  EXPECT_EQ(Socket::CS_CONNECTED, client->GetState());
+
+  // Now we should be closed and invalidated
+  EXPECT_EQ_WAIT(Socket::CS_CLOSED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_CLOSE));
+  EXPECT_TRUE(Socket::CS_CLOSED == client->GetState());
+}
+
+// Helper class specifically for the test below.
+class SocketDeleter : public sigslot::has_slots<> {
+ public:
+  explicit SocketDeleter(std::unique_ptr<Socket> socket)
+      : socket_(std::move(socket)) {}
+
+  void Delete(Socket* other) { socket_.reset(); }
+
+  bool deleted() const { return socket_ == nullptr; }
+
+ private:
+  std::unique_ptr<Socket> socket_;
+};
+
+// Tested deleting a socket within another socket's read callback. A previous
+// iteration of the select loop failed in this situation, if both sockets
+// became readable at the same time.
+void SocketTest::DeleteInReadCallbackInternal(const IPAddress& loopback) {
+  std::unique_ptr<Socket> socket1(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_DGRAM));
+  std::unique_ptr<Socket> socket2(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_DGRAM));
+  EXPECT_EQ(0, socket1->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, socket2->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(3, socket1->SendTo("foo", 3, socket1->GetLocalAddress()));
+  EXPECT_EQ(3, socket2->SendTo("bar", 3, socket1->GetLocalAddress()));
+  // Sleep a while to ensure sends are both completed at the same time.
+  Thread::SleepMs(1000);
+
+  // Configure the helper class to delete socket 2 when socket 1 has a read
+  // event.
+  SocketDeleter deleter(std::move(socket2));
+  socket1->SignalReadEvent.connect(&deleter, &SocketDeleter::Delete);
+  EXPECT_TRUE_WAIT(deleter.deleted(), kTimeout);
+}
+
+void SocketTest::SocketServerWaitInternal(const IPAddress& loopback) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create & connect server and client sockets.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  EXPECT_EQ(0, client->Connect(server->GetLocalAddress()));
+  EXPECT_TRUE_WAIT((sink.Check(server.get(), SSE_READ)), kTimeout);
+
+  std::unique_ptr<Socket> accepted(server->Accept(&accept_addr));
+  ASSERT_TRUE(accepted);
+  sink.Monitor(accepted.get());
+  EXPECT_EQ(Socket::CS_CONNECTED, accepted->GetState());
+  EXPECT_EQ(server->GetLocalAddress(), accepted->GetLocalAddress());
+  EXPECT_EQ(client->GetLocalAddress(), accepted->GetRemoteAddress());
+
+  EXPECT_EQ_WAIT(Socket::CS_CONNECTED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_FALSE(sink.Check(client.get(), SSE_CLOSE));
+  EXPECT_EQ(client->GetRemoteAddress(), server->GetLocalAddress());
+  EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
+
+  // Do an i/o operation, triggering an eventual callback.
+  EXPECT_FALSE(sink.Check(accepted.get(), SSE_READ));
+  char buf[1024] = {0};
+
+  EXPECT_EQ(1024, client->Send(buf, 1024));
+  EXPECT_FALSE(sink.Check(accepted.get(), SSE_READ));
+
+  // Shouldn't signal when blocked in a thread Send, where process_io is false.
+  std::unique_ptr<Thread> thread(Thread::CreateWithSocketServer());
+  thread->Start();
+  thread->BlockingCall([] { Thread::SleepMs(500); });
+  EXPECT_FALSE(sink.Check(accepted.get(), SSE_READ));
+
+  // But should signal when process_io is true.
+  EXPECT_TRUE_WAIT((sink.Check(accepted.get(), SSE_READ)), kTimeout);
+  EXPECT_LT(0, accepted->Recv(buf, 1024, nullptr));
+}
+
+void SocketTest::TcpInternal(const IPAddress& loopback,
+                             size_t data_size,
+                             ptrdiff_t max_send_size) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create receiving client.
+  std::unique_ptr<Socket> receiver(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(receiver.get());
+
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  // Attempt connection.
+  EXPECT_EQ(0, receiver->Connect(server->GetLocalAddress()));
+
+  // Accept connection which will be used for sending.
+  EXPECT_TRUE_WAIT((sink.Check(server.get(), SSE_READ)), kTimeout);
+  std::unique_ptr<Socket> sender(server->Accept(&accept_addr));
+  ASSERT_TRUE(sender);
+  sink.Monitor(sender.get());
+
+  // Both sides are now connected.
+  EXPECT_EQ_WAIT(Socket::CS_CONNECTED, receiver->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(receiver.get(), SSE_OPEN));
+  EXPECT_EQ(receiver->GetRemoteAddress(), sender->GetLocalAddress());
+  EXPECT_EQ(sender->GetRemoteAddress(), receiver->GetLocalAddress());
+
+  // Create test data.
+  rtc::Buffer send_buffer(0, data_size);
+  rtc::Buffer recv_buffer(0, data_size);
+  for (size_t i = 0; i < data_size; ++i) {
+    char ch = static_cast<char>(i % 256);
+    send_buffer.AppendData(&ch, sizeof(ch));
+  }
+  rtc::Buffer recved_data(0, data_size);
+
+  // Send and receive a bunch of data.
+  size_t sent_size = 0;
+  bool writable = true;
+  bool send_called = false;
+  bool readable = false;
+  bool recv_called = false;
+  while (recv_buffer.size() < send_buffer.size()) {
+    // Send as much as we can while we're cleared to send.
+    while (writable && sent_size < send_buffer.size()) {
+      int unsent_size = static_cast<int>(send_buffer.size() - sent_size);
+      int sent = sender->Send(send_buffer.data() + sent_size, unsent_size);
+      if (!send_called) {
+        // The first Send() after connecting or getting writability should
+        // succeed and send some data.
+        EXPECT_GT(sent, 0);
+        send_called = true;
+      }
+      if (sent >= 0) {
+        EXPECT_LE(sent, unsent_size);
+        sent_size += sent;
+        if (max_send_size >= 0) {
+          EXPECT_LE(static_cast<ptrdiff_t>(sent), max_send_size);
+          if (sent < unsent_size) {
+            // If max_send_size is limiting the amount to send per call such
+            // that the sent amount is less than the unsent amount, we simulate
+            // that the socket is no longer writable.
+            writable = false;
+          }
+        }
+      } else {
+        ASSERT_TRUE(sender->IsBlocking());
+        writable = false;
+      }
+    }
+
+    // Read all the sent data.
+    while (recv_buffer.size() < sent_size) {
+      if (!readable) {
+        // Wait until data is available.
+        EXPECT_TRUE_WAIT(sink.Check(receiver.get(), SSE_READ), kTimeout);
+        readable = true;
+        recv_called = false;
+      }
+
+      // Receive as much as we can get in a single recv call.
+      int recved_size = receiver->Recv(recved_data.data(), data_size, nullptr);
+
+      if (!recv_called) {
+        // The first Recv() after getting readability should succeed and receive
+        // some data.
+        // TODO: The following line is disabled due to flakey pulse
+        //     builds.  Re-enable if/when possible.
+        // EXPECT_GT(recved_size, 0);
+        recv_called = true;
+      }
+      if (recved_size >= 0) {
+        EXPECT_LE(static_cast<size_t>(recved_size),
+                  sent_size - recv_buffer.size());
+        recv_buffer.AppendData(recved_data.data(), recved_size);
+      } else {
+        ASSERT_TRUE(receiver->IsBlocking());
+        readable = false;
+      }
+    }
+
+    // Once all that we've sent has been received, expect to be able to send
+    // again.
+    if (!writable) {
+      ASSERT_TRUE_WAIT(sink.Check(sender.get(), SSE_WRITE), kTimeout);
+      writable = true;
+      send_called = false;
+    }
+  }
+
+  // The received data matches the sent data.
+  EXPECT_EQ(data_size, sent_size);
+  EXPECT_EQ(data_size, recv_buffer.size());
+  EXPECT_EQ(recv_buffer, send_buffer);
+
+  // Close down.
+  sender->Close();
+  EXPECT_EQ_WAIT(Socket::CS_CLOSED, receiver->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(receiver.get(), SSE_CLOSE));
+  receiver->Close();
+}
+
+void SocketTest::SingleFlowControlCallbackInternal(const IPAddress& loopback) {
+  StreamSink sink;
+  SocketAddress accept_addr;
+
+  // Create client.
+  std::unique_ptr<Socket> client(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(client.get());
+
+  // Create server and listen.
+  std::unique_ptr<Socket> server(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_STREAM));
+  sink.Monitor(server.get());
+  EXPECT_EQ(0, server->Bind(SocketAddress(loopback, 0)));
+  EXPECT_EQ(0, server->Listen(5));
+
+  // Attempt connection.
+  EXPECT_EQ(0, client->Connect(server->GetLocalAddress()));
+
+  // Accept connection.
+  EXPECT_TRUE_WAIT((sink.Check(server.get(), SSE_READ)), kTimeout);
+  std::unique_ptr<Socket> accepted(server->Accept(&accept_addr));
+  ASSERT_TRUE(accepted);
+  sink.Monitor(accepted.get());
+
+  // Both sides are now connected.
+  EXPECT_EQ_WAIT(Socket::CS_CONNECTED, client->GetState(), kTimeout);
+  EXPECT_TRUE(sink.Check(client.get(), SSE_OPEN));
+  EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
+  EXPECT_EQ(accepted->GetRemoteAddress(), client->GetLocalAddress());
+
+  // Expect a writable callback from the connect.
+  EXPECT_TRUE_WAIT(sink.Check(accepted.get(), SSE_WRITE), kTimeout);
+
+  // Fill the socket buffer.
+  char buf[1024 * 16] = {0};
+  int sends = 0;
+  while (++sends && accepted->Send(&buf, arraysize(buf)) != -1) {
+  }
+  EXPECT_TRUE(accepted->IsBlocking());
+
+  // Wait until data is available.
+  EXPECT_TRUE_WAIT(sink.Check(client.get(), SSE_READ), kTimeout);
+
+  // Pull data.
+  for (int i = 0; i < sends; ++i) {
+    client->Recv(buf, arraysize(buf), nullptr);
+  }
+
+  // Expect at least one additional writable callback.
+  EXPECT_TRUE_WAIT(sink.Check(accepted.get(), SSE_WRITE), kTimeout);
+
+  // Adding data in response to the writeable callback shouldn't cause infinite
+  // callbacks.
+  int extras = 0;
+  for (int i = 0; i < 100; ++i) {
+    accepted->Send(&buf, arraysize(buf));
+    rtc::Thread::Current()->ProcessMessages(1);
+    if (sink.Check(accepted.get(), SSE_WRITE)) {
+      extras++;
+    }
+  }
+  EXPECT_LT(extras, 2);
+
+  // Close down.
+  accepted->Close();
+  client->Close();
+}
+
+void SocketTest::UdpInternal(const IPAddress& loopback) {
+  SocketAddress empty = EmptySocketAddressWithFamily(loopback.family());
+  // Test basic bind and connect behavior.
+  Socket* socket = socket_factory_->CreateSocket(loopback.family(), SOCK_DGRAM);
+  EXPECT_EQ(Socket::CS_CLOSED, socket->GetState());
+  EXPECT_EQ(0, socket->Bind(SocketAddress(loopback, 0)));
+  SocketAddress addr1 = socket->GetLocalAddress();
+  EXPECT_EQ(0, socket->Connect(addr1));
+  EXPECT_EQ(Socket::CS_CONNECTED, socket->GetState());
+  socket->Close();
+  EXPECT_EQ(Socket::CS_CLOSED, socket->GetState());
+  delete socket;
+
+  // Test send/receive behavior.
+  auto client1 = std::make_unique<TestClient>(
+      absl::WrapUnique(AsyncUDPSocket::Create(socket_factory_, addr1)));
+  auto client2 = std::make_unique<TestClient>(
+      absl::WrapUnique(AsyncUDPSocket::Create(socket_factory_, empty)));
+
+  SocketAddress addr2;
+  EXPECT_EQ(3, client2->SendTo("foo", 3, addr1));
+  EXPECT_TRUE(client1->CheckNextPacket("foo", 3, &addr2));
+
+  SocketAddress addr3;
+  EXPECT_EQ(6, client1->SendTo("bizbaz", 6, addr2));
+  EXPECT_TRUE(client2->CheckNextPacket("bizbaz", 6, &addr3));
+  EXPECT_EQ(addr3, addr1);
+  // TODO: figure out what the intent is here
+  for (int i = 0; i < 10; ++i) {
+    client2 = std::make_unique<TestClient>(
+        absl::WrapUnique(AsyncUDPSocket::Create(socket_factory_, empty)));
+
+    SocketAddress addr4;
+    EXPECT_EQ(3, client2->SendTo("foo", 3, addr1));
+    EXPECT_TRUE(client1->CheckNextPacket("foo", 3, &addr4));
+    EXPECT_EQ(addr4.ipaddr(), addr2.ipaddr());
+
+    SocketAddress addr5;
+    EXPECT_EQ(6, client1->SendTo("bizbaz", 6, addr4));
+    EXPECT_TRUE(client2->CheckNextPacket("bizbaz", 6, &addr5));
+    EXPECT_EQ(addr5, addr1);
+
+    addr2 = addr4;
+  }
+}
+
+void SocketTest::UdpReadyToSend(const IPAddress& loopback) {
+  SocketAddress empty = EmptySocketAddressWithFamily(loopback.family());
+  // RFC 5737 - The blocks 192.0.2.0/24 (TEST-NET-1) ... are provided for use in
+  // documentation.
+  // RFC 3849 - 2001:DB8::/32 as a documentation-only prefix.
+  std::string dest =
+      (loopback.family() == AF_INET6) ? "2001:db8::1" : "192.0.2.0";
+  SocketAddress test_addr(dest, 2345);
+
+  // Test send
+  auto client = std::make_unique<TestClient>(
+      absl::WrapUnique(AsyncUDPSocket::Create(socket_factory_, empty)));
+  int test_packet_size = 1200;
+  std::unique_ptr<char[]> test_packet(new char[test_packet_size]);
+  // Init the test packet just to avoid memcheck warning.
+  memset(test_packet.get(), 0, test_packet_size);
+  // Set the send buffer size to the same size as the test packet to have a
+  // better chance to get EWOULDBLOCK.
+  int send_buffer_size = test_packet_size;
+#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
+  send_buffer_size /= 2;
+#endif
+  client->SetOption(rtc::Socket::OPT_SNDBUF, send_buffer_size);
+
+  int error = 0;
+  uint32_t start_ms = Time();
+  int sent_packet_num = 0;
+  int expected_error = EWOULDBLOCK;
+  while (start_ms + kTimeout > Time()) {
+    int ret = client->SendTo(test_packet.get(), test_packet_size, test_addr);
+    ++sent_packet_num;
+    if (ret != test_packet_size) {
+      error = client->GetError();
+      if (error == expected_error) {
+        RTC_LOG(LS_INFO) << "Got expected error code after sending "
+                         << sent_packet_num << " packets.";
+        break;
+      }
+    }
+  }
+  EXPECT_EQ(expected_error, error);
+  EXPECT_FALSE(client->ready_to_send());
+  EXPECT_TRUE_WAIT(client->ready_to_send(), kTimeout);
+  RTC_LOG(LS_INFO) << "Got SignalReadyToSend";
+}
+
+void SocketTest::GetSetOptionsInternal(const IPAddress& loopback) {
+  std::unique_ptr<Socket> socket(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_DGRAM));
+  socket->Bind(SocketAddress(loopback, 0));
+
+  // Check SNDBUF/RCVBUF.
+  const int desired_size = 12345;
+#if defined(WEBRTC_LINUX)
+  // Yes, really.  It's in the kernel source.
+  const int expected_size = desired_size * 2;
+#else   // !WEBRTC_LINUX
+  const int expected_size = desired_size;
+#endif  // !WEBRTC_LINUX
+  int recv_size = 0;
+  int send_size = 0;
+  // get the initial sizes
+  ASSERT_NE(-1, socket->GetOption(Socket::OPT_RCVBUF, &recv_size));
+  ASSERT_NE(-1, socket->GetOption(Socket::OPT_SNDBUF, &send_size));
+  // set our desired sizes
+  ASSERT_NE(-1, socket->SetOption(Socket::OPT_RCVBUF, desired_size));
+  ASSERT_NE(-1, socket->SetOption(Socket::OPT_SNDBUF, desired_size));
+  // get the sizes again
+  ASSERT_NE(-1, socket->GetOption(Socket::OPT_RCVBUF, &recv_size));
+  ASSERT_NE(-1, socket->GetOption(Socket::OPT_SNDBUF, &send_size));
+  // make sure they are right
+  ASSERT_EQ(expected_size, recv_size);
+  ASSERT_EQ(expected_size, send_size);
+
+  // Check that we can't set NODELAY on a UDP socket.
+  int current_nd, desired_nd = 1;
+  ASSERT_EQ(-1, socket->GetOption(Socket::OPT_NODELAY, &current_nd));
+  ASSERT_EQ(-1, socket->SetOption(Socket::OPT_NODELAY, desired_nd));
+
+#if defined(WEBRTC_POSIX)
+  // Check DSCP.
+  int current_dscp, desired_dscp = 1;
+  ASSERT_NE(-1, socket->GetOption(Socket::OPT_DSCP, &current_dscp));
+  ASSERT_NE(-1, socket->SetOption(Socket::OPT_DSCP, desired_dscp));
+  ASSERT_NE(-1, socket->GetOption(Socket::OPT_DSCP, &current_dscp));
+  ASSERT_EQ(desired_dscp, current_dscp);
+#endif
+}
+
+void SocketTest::SocketRecvTimestamp(const IPAddress& loopback) {
+  StreamSink sink;
+  std::unique_ptr<Socket> socket(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_DGRAM));
+  EXPECT_EQ(0, socket->Bind(SocketAddress(loopback, 0)));
+  SocketAddress address = socket->GetLocalAddress();
+  sink.Monitor(socket.get());
+
+  int64_t send_time_1 = TimeMicros();
+  socket->SendTo("foo", 3, address);
+
+  int64_t recv_timestamp_1;
+  // Wait until data is available.
+  EXPECT_TRUE_WAIT(sink.Check(socket.get(), SSE_READ), kTimeout);
+  char buffer[3];
+  ASSERT_GT(socket->RecvFrom(buffer, 3, nullptr, &recv_timestamp_1), 0);
+
+  const int64_t kTimeBetweenPacketsMs = 100;
+  Thread::SleepMs(kTimeBetweenPacketsMs);
+
+  int64_t send_time_2 = TimeMicros();
+  socket->SendTo("bar", 3, address);
+  // Wait until data is available.
+  EXPECT_TRUE_WAIT(sink.Check(socket.get(), SSE_READ), kTimeout);
+  int64_t recv_timestamp_2;
+  ASSERT_GT(socket->RecvFrom(buffer, 3, nullptr, &recv_timestamp_2), 0);
+
+  int64_t system_time_diff = send_time_2 - send_time_1;
+  int64_t recv_timestamp_diff = recv_timestamp_2 - recv_timestamp_1;
+  // Compare against the system time at the point of sending, because
+  // SleepMs may not sleep for exactly the requested time.
+  EXPECT_NEAR(system_time_diff, recv_timestamp_diff, 10000);
+}
+
+void SocketTest::UdpSocketRecvTimestampUseRtcEpoch(const IPAddress& loopback) {
+  SocketAddress empty = EmptySocketAddressWithFamily(loopback.family());
+  std::unique_ptr<Socket> socket(
+      socket_factory_->CreateSocket(loopback.family(), SOCK_DGRAM));
+  ASSERT_EQ(socket->Bind(SocketAddress(loopback, 0)), 0);
+  SocketAddress address = socket->GetLocalAddress();
+  socket = nullptr;
+
+  auto client1 = std::make_unique<TestClient>(
+      absl::WrapUnique(AsyncUDPSocket::Create(socket_factory_, address)));
+  auto client2 = std::make_unique<TestClient>(
+      absl::WrapUnique(AsyncUDPSocket::Create(socket_factory_, empty)));
+
+  SocketAddress addr2;
+  client2->SendTo("foo", 3, address);
+  std::unique_ptr<TestClient::Packet> packet_1 = client1->NextPacket(10000);
+  ASSERT_TRUE(packet_1 != nullptr);
+  EXPECT_NEAR(packet_1->packet_time_us, rtc::TimeMicros(), 1000'000);
+
+  Thread::SleepMs(100);
+  client2->SendTo("bar", 3, address);
+  std::unique_ptr<TestClient::Packet> packet_2 = client1->NextPacket(10000);
+  ASSERT_TRUE(packet_2 != nullptr);
+  EXPECT_GT(packet_2->packet_time_us, packet_1->packet_time_us);
+  EXPECT_NEAR(packet_2->packet_time_us, rtc::TimeMicros(), 1000'000);
+}
+}  // namespace rtc