UDP sockets implementation for windows.

net/udp/udp_socket_win.cc

+// Copyright (c) 2011 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_win.h"
+
+#include <mstcpip.h>
+
+#include "base/eintr_wrapper.h"
+#include "base/logging.h"
+#include "base/message_loop.h"
+#include "base/memory_debug.h"
+#include "base/metrics/stats_counters.h"
+#include "net/base/io_buffer.h"
+#include "net/base/ip_endpoint.h"
+#include "net/base/net_errors.h"
+#include "net/base/net_log.h"
+#include "net/base/net_util.h"
+#include "net/base/winsock_init.h"
+#include "net/base/winsock_util.h"
+
+namespace net {
+
+void UDPSocketWin::ReadDelegate::OnObjectSignaled(HANDLE object) {
+  DCHECK_EQ(object, socket_->read_overlapped_.hEvent);
+  socket_->DidCompleteRead();
+}
+
+void UDPSocketWin::WriteDelegate::OnObjectSignaled(HANDLE object) {
+  DCHECK_EQ(object, socket_->write_overlapped_.hEvent);
+  socket_->DidCompleteWrite();
+}
+
+UDPSocketWin::UDPSocketWin(net::NetLog* net_log,
+                           const net::NetLog::Source& source)
+    : socket_(INVALID_SOCKET),
+      ALLOW_THIS_IN_INITIALIZER_LIST(read_delegate_(this)),
+      ALLOW_THIS_IN_INITIALIZER_LIST(write_delegate_(this)),
+      recv_from_address_(NULL),
+      read_callback_(NULL),
+      write_callback_(NULL),
+      net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_SOCKET)) {
+  EnsureWinsockInit();
+  scoped_refptr<NetLog::EventParameters> params;
+  if (source.is_valid())
+    params = new NetLogSourceParameter("source_dependency", source);
+  net_log_.BeginEvent(NetLog::TYPE_SOCKET_ALIVE, params);
+  memset(&read_overlapped_, 0, sizeof(read_overlapped_));
+  read_overlapped_.hEvent = WSACreateEvent();
+  memset(&write_overlapped_, 0, sizeof(write_overlapped_));
+  write_overlapped_.hEvent = WSACreateEvent();
+}
+
+UDPSocketWin::~UDPSocketWin() {
+  Close();
+  net_log_.EndEvent(NetLog::TYPE_SOCKET_ALIVE, NULL);
+}
+
+void UDPSocketWin::Close() {
+  DCHECK(CalledOnValidThread());
+
+  if (!is_connected())
+    return;
+
+  if (read_callback_)
+    DoReadCallback(ERR_ABORTED);
+  if (write_callback_)
+    DoReadCallback(ERR_ABORTED);
+
+  read_watcher_.StopWatching();
+  write_watcher_.StopWatching();
+
+  closesocket(socket_);
+  socket_ = INVALID_SOCKET;
+}
+
+int UDPSocketWin::GetPeerAddress(IPEndPoint* address) const {
+  DCHECK(CalledOnValidThread());
+  DCHECK(address);
+  if (!is_connected())
+    return ERR_SOCKET_NOT_CONNECTED;
+
+  if (!remote_address_.get()) {
+    struct sockaddr_storage addr_storage;
+    int addr_len = sizeof(addr_storage);
+    struct sockaddr* addr = reinterpret_cast<struct sockaddr*>(&addr_storage);
+    if (getpeername(socket_, addr, &addr_len))
+      return MapWinsockError(WSAGetLastError());
+    scoped_ptr<IPEndPoint> address(new IPEndPoint());
+    if (!address->FromSockAddr(addr, addr_len))
+      return ERR_FAILED;
+    remote_address_.reset(address.release());
+  }
+
+  *address = *remote_address_;
+  return OK;
+}
+
+int UDPSocketWin::GetLocalAddress(IPEndPoint* address) const {
+  DCHECK(CalledOnValidThread());
+  DCHECK(address);
+  if (!is_connected())
+    return ERR_SOCKET_NOT_CONNECTED;
+
+  if (!local_address_.get()) {
+    struct sockaddr_storage addr_storage;
+    socklen_t addr_len = sizeof(addr_storage);
+    struct sockaddr* addr = reinterpret_cast<struct sockaddr*>(&addr_storage);
+    if (getsockname(socket_, addr, &addr_len))
+      return MapWinsockError(WSAGetLastError());
+    scoped_ptr<IPEndPoint> address(new IPEndPoint());
+    if (!address->FromSockAddr(addr, addr_len))
+      return ERR_FAILED;
+    local_address_.reset(address.release());
+  }
+
+  *address = *local_address_;
+  return OK;
+}
+
+int UDPSocketWin::RecvFrom(IOBuffer* buf,
+                           int buf_len,
+                           IPEndPoint* address,
+                           CompletionCallback* callback) {
+  DCHECK(!recv_from_address_);
+  recv_from_address_ = address;
+  return Read(buf, buf_len, callback);
+}
+
+int UDPSocketWin::Read(IOBuffer* buf,
+                       int buf_len,
+                       CompletionCallback* callback) {
+  DCHECK(CalledOnValidThread());
+  DCHECK_NE(INVALID_SOCKET, socket_);
+  DCHECK(!read_callback_);
+  DCHECK(callback);  // Synchronous operation not supported.
+  DCHECK_GT(buf_len, 0);
+
+  int nread = InternalRead(buf, buf_len);
+  if (nread != ERR_IO_PENDING)
+    return nread;
+
+  read_iobuffer_ = buf;
+  read_callback_ = callback;
+  return ERR_IO_PENDING;
+}
+
+int UDPSocketWin::SendTo(IOBuffer* buf,
+                         int buf_len,
+                         const IPEndPoint& address,
+                         CompletionCallback* callback) {
+  send_to_address_.reset(new IPEndPoint(address));
+  return Write(buf, buf_len, callback);
+}
+
+int UDPSocketWin::Write(IOBuffer* buf,
+                        int buf_len,
+                        CompletionCallback* callback) {
+  DCHECK(CalledOnValidThread());
+  DCHECK_NE(INVALID_SOCKET, socket_);
+  DCHECK(!write_callback_);
+  DCHECK(callback);  // Synchronous operation not supported.
+  DCHECK_GT(buf_len, 0);
+
+  int nwrite = InternalWrite(buf, buf_len);
+  if (nwrite != ERR_IO_PENDING)
+    return nwrite;
+
+  write_iobuffer_ = buf;
+  write_callback_ = callback;
+  return ERR_IO_PENDING;
+}
+
+int UDPSocketWin::Connect(const IPEndPoint& address) {
+  DCHECK(!is_connected());
+  DCHECK(!remote_address_.get());
+  int rv = CreateSocket(address);
+  if (rv < 0)
+    return rv;
+
+  struct sockaddr_storage addr_storage;
+  size_t addr_len = sizeof(addr_storage);
+  struct sockaddr* addr = reinterpret_cast<struct sockaddr*>(&addr_storage);
+  if (!address.ToSockAddr(addr, &addr_len))
+    return ERR_FAILED;
+
+  rv = connect(socket_, addr, addr_len);
+  if (rv < 0)
+    return MapWinsockError(WSAGetLastError());
+
+  remote_address_.reset(new IPEndPoint(address));
+  return rv;
+}
+
+int UDPSocketWin::Bind(const IPEndPoint& address) {
+  DCHECK(!is_connected());
+  DCHECK(!local_address_.get());
+  int rv = CreateSocket(address);
+  if (rv < 0)
+    return rv;
+
+  struct sockaddr_storage addr_storage;
+  size_t addr_len = sizeof(addr_storage);
+  struct sockaddr* addr = reinterpret_cast<struct sockaddr*>(&addr_storage);
+  if (!address.ToSockAddr(addr, &addr_len))
+    return ERR_FAILED;
+
+  rv = bind(socket_, addr, addr_len);
+  if (rv < 0)
+    return MapWinsockError(WSAGetLastError());
+
+  local_address_.reset(new IPEndPoint(address));
+  return rv;
+}
+
+int UDPSocketWin::CreateSocket(const IPEndPoint& address) {
+  socket_ = WSASocket(address.GetFamily(), SOCK_DGRAM, IPPROTO_UDP, NULL, 0,
+                      WSA_FLAG_OVERLAPPED);
+  if (socket_ == INVALID_SOCKET)
+    return MapWinsockError(WSAGetLastError());
+  return OK;
+}
+
+void UDPSocketWin::DoReadCallback(int rv) {
+  DCHECK_NE(rv, ERR_IO_PENDING);
+  DCHECK(read_callback_);
+
+  // since Run may result in Read being called, clear read_callback_ up front.
+  CompletionCallback* c = read_callback_;
+  read_callback_ = NULL;
+  recv_from_address_ = NULL;
+  c->Run(rv);
+}
+
+void UDPSocketWin::DoWriteCallback(int rv) {
+  DCHECK_NE(rv, ERR_IO_PENDING);
+  DCHECK(write_callback_);
+
+  // since Run may result in Write being called, clear write_callback_ up front.
+  CompletionCallback* c = write_callback_;
+  write_callback_ = NULL;
+  send_to_address_.reset();
+  c->Run(rv);
+}
+
+void UDPSocketWin::DidCompleteRead() {
+  DWORD num_bytes, flags;
+  BOOL ok = WSAGetOverlappedResult(socket_, &read_overlapped_,
+                                   &num_bytes, FALSE, &flags);
+  WSAResetEvent(read_overlapped_.hEvent);
+  int result = ok ? num_bytes : MapWinsockError(WSAGetLastError());
+  if (ok) {
+    if (!ProcessSuccessfulRead(num_bytes))
+      result = ERR_FAILED;
+  }
+  read_iobuffer_ = NULL;
+  DoReadCallback(result);
+}
+
+bool UDPSocketWin::ProcessSuccessfulRead(int num_bytes) {
+  static base::StatsCounter read_bytes("udp.read_bytes");
+  read_bytes.Add(num_bytes);
+
+  // Convert address.
+  if (recv_from_address_) {
+    struct sockaddr* addr =
+        reinterpret_cast<struct sockaddr*>(&recv_addr_storage_);
+    if (!recv_from_address_->FromSockAddr(addr, recv_addr_len_))
+      return false;
+  }
+
+  return true;
+}
+
+void UDPSocketWin::DidCompleteWrite() {
+  DWORD num_bytes, flags;
+  BOOL ok = WSAGetOverlappedResult(socket_, &write_overlapped_,
+                                   &num_bytes, FALSE, &flags);
+  WSAResetEvent(write_overlapped_.hEvent);
+  int result = ok ? num_bytes : MapWinsockError(WSAGetLastError());
+  if (ok)
+    ProcessSuccessfulWrite(num_bytes);
+  write_iobuffer_ = NULL;
+  DoWriteCallback(result);
+}
+
+void UDPSocketWin::ProcessSuccessfulWrite(int num_bytes) {
+  static base::StatsCounter write_bytes("udp.write_bytes");
+  write_bytes.Add(num_bytes);
+}
+
+int UDPSocketWin::InternalRead(IOBuffer* buf, int buf_len) {
+  recv_addr_len_ = sizeof(recv_addr_storage_);
+  struct sockaddr* addr =
+      reinterpret_cast<struct sockaddr*>(&recv_addr_storage_);
+
+  WSABUF read_buffer;
+  read_buffer.buf = buf->data();
+  read_buffer.len = buf_len;

[Mike Belshe, 2011/03/11 14:31:28]

Ah - this is even better.  Great.

+
+  DWORD flags = 0;
+  DWORD num;
+  AssertEventNotSignaled(read_overlapped_.hEvent);
+  int rv = WSARecvFrom(socket_, &read_buffer, 1, &num, &flags, addr,
+                       &recv_addr_len_, &read_overlapped_, NULL);
+  if (rv == 0) {
+    if (ResetEventIfSignaled(read_overlapped_.hEvent)) {
+      // Because of how WSARecv fills memory when used asynchronously, Purify
+      // isn't able to detect that it's been initialized, so it scans for 0xcd
+      // in the buffer and reports UMRs (uninitialized memory reads) for those
+      // individual bytes. We override that in PURIFY builds to avoid the
+      // false error reports.
+      // See bug 5297.
+      base::MemoryDebug::MarkAsInitialized(read_buffer.buf, num);
+      if (!ProcessSuccessfulRead(num))
+        return ERR_FAILED;
+      return static_cast<int>(num);
+    }
+  } else {
+    int os_error = WSAGetLastError();
+    if (os_error != WSA_IO_PENDING)
+      return MapWinsockError(os_error);
+  }
+  read_watcher_.StartWatching(read_overlapped_.hEvent, &read_delegate_);
+  return ERR_IO_PENDING;
+}
+
+int UDPSocketWin::InternalWrite(IOBuffer* buf, int buf_len) {
+  struct sockaddr_storage addr_storage;
+  size_t addr_len = sizeof(addr_storage);
+  struct sockaddr* addr = reinterpret_cast<struct sockaddr*>(&addr_storage);
+
+  // Convert address.
+  if (!send_to_address_.get()) {
+    addr = NULL;
+    addr_len = 0;
+  } else {
+    if (!send_to_address_->ToSockAddr(addr, &addr_len))
+      return ERR_FAILED;
+  }
+
+  WSABUF write_buffer;
+  write_buffer.buf = buf->data();
+  write_buffer.len = buf_len;
+
+  DWORD flags = 0;
+  DWORD num;
+  AssertEventNotSignaled(write_overlapped_.hEvent);
+  int rv = WSASendTo(socket_, &write_buffer, 1, &num, flags,
+                     addr, addr_len, &write_overlapped_, NULL);
+  if (rv == 0) {
+    if (ResetEventIfSignaled(write_overlapped_.hEvent)) {
+      ProcessSuccessfulWrite(num);
+      return static_cast<int>(num);
+    }
+  } else {
+    int os_error = WSAGetLastError();
+    if (os_error != WSA_IO_PENDING)
+      return MapWinsockError(os_error);
+  }
+
+  write_watcher_.StartWatching(write_overlapped_.hEvent, &write_delegate_);
+  return ERR_IO_PENDING;
+}
+
+}  // namespace net