// Copyright (c) 2010 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/socket/tcp_client_socket.h"
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#if defined(OS_POSIX)
#include <netinet/in.h>
#endif
#include "base/eintr_wrapper.h"
#include "base/logging.h"
#include "base/message_loop.h"
#include "base/metrics/stats_counters.h"
#include "base/string_util.h"
#include "net/base/address_list_net_log_param.h"
#include "net/base/connection_type_histograms.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/network_change_notifier.h"
#if defined(USE_SYSTEM_LIBEVENT)
#include <event.h>
#else
#include "third_party/libevent/event.h"
#endif
#ifdef ANDROID
#include <cutils/qtaguid.h>
#endif
namespace net {
namespace {
const int kInvalidSocket = -1;
// DisableNagle turns off buffering in the kernel. By default, TCP sockets will
// wait up to 200ms for more data to complete a packet before transmitting.
// After calling this function, the kernel will not wait. See TCP_NODELAY in
// `man 7 tcp`.
int DisableNagle(int fd) {
int on = 1;
return setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on));
}
// SetTCPKeepAlive sets SO_KEEPALIVE.
void SetTCPKeepAlive(int fd) {
int optval = 1;
socklen_t optlen = sizeof(optval);
if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &optval, optlen)) {
PLOG(ERROR) << "Failed to set SO_KEEPALIVE on fd: " << fd;
return;
}
#if defined(OS_LINUX)
// Set seconds until first TCP keep alive.
#ifdef ANDROID
optval = 25;
#else
optval = 45;
#endif
if (setsockopt(fd, SOL_TCP, TCP_KEEPIDLE, &optval, optlen)) {
PLOG(ERROR) << "Failed to set TCP_KEEPIDLE on fd: " << fd;
return;
}
// Set seconds between TCP keep alives.
if (setsockopt(fd, SOL_TCP, TCP_KEEPINTVL, &optval, optlen)) {
PLOG(ERROR) << "Failed to set TCP_KEEPINTVL on fd: " << fd;
return;
}
#endif
}
int MapConnectError(int os_error) {
switch (os_error) {
case EACCES:
return ERR_NETWORK_ACCESS_DENIED;
case ETIMEDOUT:
return ERR_CONNECTION_TIMED_OUT;
default: {
int net_error = MapSystemError(os_error);
if (net_error == ERR_FAILED)
return ERR_CONNECTION_FAILED; // More specific than ERR_FAILED.
// Give a more specific error when the user is offline.
if (net_error == ERR_ADDRESS_UNREACHABLE &&
NetworkChangeNotifier::IsOffline()) {
return ERR_INTERNET_DISCONNECTED;
}
return net_error;
}
}
}
} // namespace
//-----------------------------------------------------------------------------
TCPClientSocketLibevent::TCPClientSocketLibevent(
const AddressList& addresses,
net::NetLog* net_log,
const net::NetLog::Source& source)
: socket_(kInvalidSocket),
addresses_(addresses),
current_ai_(NULL),
read_watcher_(this),
write_watcher_(this),
read_callback_(NULL),
write_callback_(NULL),
next_connect_state_(CONNECT_STATE_NONE),
connect_os_error_(0),
net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_SOCKET)),
previously_disconnected_(false),
use_tcp_fastopen_(false),
tcp_fastopen_connected_(false)
#ifdef ANDROID
, wait_for_connect_(false)
, valid_uid_(false)
, calling_uid_(0)
#endif
{
scoped_refptr<NetLog::EventParameters> params;
if (source.is_valid())
params = new NetLogSourceParameter("source_dependency", source);
net_log_.BeginEvent(NetLog::TYPE_SOCKET_ALIVE, params);
if (is_tcp_fastopen_enabled())
use_tcp_fastopen_ = true;
}
TCPClientSocketLibevent::~TCPClientSocketLibevent() {
Disconnect();
net_log_.EndEvent(NetLog::TYPE_SOCKET_ALIVE, NULL);
}
void TCPClientSocketLibevent::AdoptSocket(int socket) {
DCHECK_EQ(socket_, kInvalidSocket);
socket_ = socket;
int error = SetupSocket();
DCHECK_EQ(0, error);
// This is to make GetPeerAddress work. It's up to the test that is calling
// this function to ensure that address_ contains a reasonable address for
// this socket. (i.e. at least match IPv4 vs IPv6!).
current_ai_ = addresses_.head();
use_history_.set_was_ever_connected();
}
int TCPClientSocketLibevent::Connect(CompletionCallback* callback
#ifdef ANDROID
, bool wait_for_connect
, bool valid_uid
, uid_t calling_uid
#endif
) {
#ifdef ANDROID
wait_for_connect_ = wait_for_connect;
valid_uid_ = valid_uid;
calling_uid_ = calling_uid;
#endif
DCHECK(CalledOnValidThread());
// If already connected, then just return OK.
if (socket_ != kInvalidSocket)
return OK;
base::StatsCounter connects("tcp.connect");
connects.Increment();
DCHECK(!waiting_connect());
net_log_.BeginEvent(
NetLog::TYPE_TCP_CONNECT,
make_scoped_refptr(new AddressListNetLogParam(addresses_)));
// We will try to connect to each address in addresses_. Start with the
// first one in the list.
next_connect_state_ = CONNECT_STATE_CONNECT;
current_ai_ = addresses_.head();
int rv = DoConnectLoop(OK);
if (rv == ERR_IO_PENDING) {
// Synchronous operation not supported.
DCHECK(callback);
write_callback_ = callback;
} else {
LogConnectCompletion(rv);
}
return rv;
}
int TCPClientSocketLibevent::DoConnectLoop(int result) {
DCHECK_NE(next_connect_state_, CONNECT_STATE_NONE);
int rv = result;
do {
ConnectState state = next_connect_state_;
next_connect_state_ = CONNECT_STATE_NONE;
switch (state) {
case CONNECT_STATE_CONNECT:
DCHECK_EQ(OK, rv);
rv = DoConnect();
break;
case CONNECT_STATE_CONNECT_COMPLETE:
rv = DoConnectComplete(rv);
break;
default:
LOG(DFATAL) << "bad state";
rv = ERR_UNEXPECTED;
break;
}
} while (rv != ERR_IO_PENDING && next_connect_state_ != CONNECT_STATE_NONE);
return rv;
}
int TCPClientSocketLibevent::DoConnect() {
DCHECK(current_ai_);
DCHECK_EQ(0, connect_os_error_);
if (previously_disconnected_) {
use_history_.Reset();
previously_disconnected_ = false;
}
net_log_.BeginEvent(NetLog::TYPE_TCP_CONNECT_ATTEMPT,
make_scoped_refptr(new NetLogStringParameter(
"address", NetAddressToStringWithPort(current_ai_))));
next_connect_state_ = CONNECT_STATE_CONNECT_COMPLETE;
// Create a non-blocking socket.
connect_os_error_ = CreateSocket(current_ai_);
if (connect_os_error_)
return MapSystemError(connect_os_error_);
// Connect the socket.
if (!use_tcp_fastopen_) {
if (!HANDLE_EINTR(connect(socket_, current_ai_->ai_addr,
static_cast<int>(current_ai_->ai_addrlen)))) {
// Connected without waiting!
return OK;
#ifdef ANDROID
} else if (errno == EINPROGRESS && wait_for_connect_) {
fd_set writeset;
FD_ZERO(&writeset);
FD_SET(socket_, &writeset);
timeval tv;
tv.tv_sec = 20;
tv.tv_usec = 0;
int res = HANDLE_EINTR(select(socket_ + 1, 0, &writeset, 0, &tv));
if (res > 0)
return OK;
return MapConnectError(ETIMEDOUT);
#endif
}
} else {
// With TCP FastOpen, we pretend that the socket is connected.
DCHECK(!tcp_fastopen_connected_);
return OK;
}
// Check if the connect() failed synchronously.
connect_os_error_ = errno;
if (connect_os_error_ != EINPROGRESS)
return MapConnectError(connect_os_error_);
// Otherwise the connect() is going to complete asynchronously, so watch
// for its completion.
if (!MessageLoopForIO::current()->WatchFileDescriptor(
socket_, true, MessageLoopForIO::WATCH_WRITE, &write_socket_watcher_,
&write_watcher_)) {
connect_os_error_ = errno;
DVLOG(1) << "WatchFileDescriptor failed: " << connect_os_error_;
return MapSystemError(connect_os_error_);
}
return ERR_IO_PENDING;
}
int TCPClientSocketLibevent::DoConnectComplete(int result) {
// Log the end of this attempt (and any OS error it threw).
int os_error = connect_os_error_;
connect_os_error_ = 0;
scoped_refptr<NetLog::EventParameters> params;
if (result != OK)
params = new NetLogIntegerParameter("os_error", os_error);
net_log_.EndEvent(NetLog::TYPE_TCP_CONNECT_ATTEMPT, params);
write_socket_watcher_.StopWatchingFileDescriptor();
if (result == OK) {
use_history_.set_was_ever_connected();
return OK; // Done!
}
// Close whatever partially connected socket we currently have.
DoDisconnect();
// Try to fall back to the next address in the list.
if (current_ai_->ai_next) {
next_connect_state_ = CONNECT_STATE_CONNECT;
current_ai_ = current_ai_->ai_next;
return OK;
}
// Otherwise there is nothing to fall back to, so give up.
return result;
}
void TCPClientSocketLibevent::Disconnect() {
DCHECK(CalledOnValidThread());
DoDisconnect();
current_ai_ = NULL;
}
void TCPClientSocketLibevent::DoDisconnect() {
if (socket_ == kInvalidSocket)
return;
bool ok = read_socket_watcher_.StopWatchingFileDescriptor();
DCHECK(ok);
ok = write_socket_watcher_.StopWatchingFileDescriptor();
DCHECK(ok);
#ifdef ANDROID
if (valid_uid_)
qtaguid_untagSocket(socket_);
#endif
if (HANDLE_EINTR(close(socket_)) < 0)
PLOG(ERROR) << "close";
socket_ = kInvalidSocket;
previously_disconnected_ = true;
}
bool TCPClientSocketLibevent::IsConnected() const {
DCHECK(CalledOnValidThread());
if (socket_ == kInvalidSocket || waiting_connect())
return false;
// Check if connection is alive.
char c;
int rv = HANDLE_EINTR(recv(socket_, &c, 1, MSG_PEEK));
if (rv == 0)
return false;
if (rv == -1 && errno != EAGAIN && errno != EWOULDBLOCK)
return false;
return true;
}
bool TCPClientSocketLibevent::IsConnectedAndIdle() const {
DCHECK(CalledOnValidThread());
if (socket_ == kInvalidSocket || waiting_connect())
return false;
// Check if connection is alive and we haven't received any data
// unexpectedly.
char c;
int rv = HANDLE_EINTR(recv(socket_, &c, 1, MSG_PEEK));
if (rv >= 0)
return false;
if (errno != EAGAIN && errno != EWOULDBLOCK)
return false;
return true;
}
int TCPClientSocketLibevent::Read(IOBuffer* buf,
int buf_len,
CompletionCallback* callback) {
DCHECK(CalledOnValidThread());
DCHECK_NE(kInvalidSocket, socket_);
DCHECK(!waiting_connect());
DCHECK(!read_callback_);
// Synchronous operation not supported
DCHECK(callback);
DCHECK_GT(buf_len, 0);
int nread = HANDLE_EINTR(read(socket_, buf->data(), buf_len));
if (nread >= 0) {
base::StatsCounter read_bytes("tcp.read_bytes");
read_bytes.Add(nread);
if (nread > 0)
use_history_.set_was_used_to_convey_data();
LogByteTransfer(
net_log_, NetLog::TYPE_SOCKET_BYTES_RECEIVED, nread, buf->data());
return nread;
}
if (errno != EAGAIN && errno != EWOULDBLOCK) {
DVLOG(1) << "read failed, errno " << errno;
return MapSystemError(errno);
}
if (!MessageLoopForIO::current()->WatchFileDescriptor(
socket_, true, MessageLoopForIO::WATCH_READ,
&read_socket_watcher_, &read_watcher_)) {
DVLOG(1) << "WatchFileDescriptor failed on read, errno " << errno;
return MapSystemError(errno);
}
read_buf_ = buf;
read_buf_len_ = buf_len;
read_callback_ = callback;
return ERR_IO_PENDING;
}
int TCPClientSocketLibevent::Write(IOBuffer* buf,
int buf_len,
CompletionCallback* callback) {
DCHECK(CalledOnValidThread());
DCHECK_NE(kInvalidSocket, socket_);
DCHECK(!waiting_connect());
DCHECK(!write_callback_);
// Synchronous operation not supported
DCHECK(callback);
DCHECK_GT(buf_len, 0);
int nwrite = InternalWrite(buf, buf_len);
if (nwrite >= 0) {
base::StatsCounter write_bytes("tcp.write_bytes");
write_bytes.Add(nwrite);
if (nwrite > 0)
use_history_.set_was_used_to_convey_data();
LogByteTransfer(
net_log_, NetLog::TYPE_SOCKET_BYTES_SENT, nwrite, buf->data());
return nwrite;
}
if (errno != EAGAIN && errno != EWOULDBLOCK)
return MapSystemError(errno);
if (!MessageLoopForIO::current()->WatchFileDescriptor(
socket_, true, MessageLoopForIO::WATCH_WRITE,
&write_socket_watcher_, &write_watcher_)) {
DVLOG(1) << "WatchFileDescriptor failed on write, errno " << errno;
return MapSystemError(errno);
}
write_buf_ = buf;
write_buf_len_ = buf_len;
write_callback_ = callback;
return ERR_IO_PENDING;
}
int TCPClientSocketLibevent::InternalWrite(IOBuffer* buf, int buf_len) {
int nwrite;
if (use_tcp_fastopen_ && !tcp_fastopen_connected_) {
// We have a limited amount of data to send in the SYN packet.
int kMaxFastOpenSendLength = 1420;
buf_len = std::min(kMaxFastOpenSendLength, buf_len);
int flags = 0x20000000; // Magic flag to enable TCP_FASTOPEN
nwrite = HANDLE_EINTR(sendto(socket_,
buf->data(),
buf_len,
flags,
current_ai_->ai_addr,
static_cast<int>(current_ai_->ai_addrlen)));
tcp_fastopen_connected_ = true;
if (nwrite < 0) {
// Non-blocking mode is returning EINPROGRESS rather than EAGAIN.
if (errno == EINPROGRESS)
errno = EAGAIN;
// Unlike "normal" nonblocking sockets, the data is already queued,
// so tell the app that we've consumed it.
return buf_len;
}
} else {
nwrite = HANDLE_EINTR(write(socket_, buf->data(), buf_len));
}
return nwrite;
}
bool TCPClientSocketLibevent::SetReceiveBufferSize(int32 size) {
DCHECK(CalledOnValidThread());
int rv = setsockopt(socket_, SOL_SOCKET, SO_RCVBUF,
reinterpret_cast<const char*>(&size),
sizeof(size));
DCHECK(!rv) << "Could not set socket receive buffer size: " << errno;
return rv == 0;
}
bool TCPClientSocketLibevent::SetSendBufferSize(int32 size) {
DCHECK(CalledOnValidThread());
int rv = setsockopt(socket_, SOL_SOCKET, SO_SNDBUF,
reinterpret_cast<const char*>(&size),
sizeof(size));
DCHECK(!rv) << "Could not set socket send buffer size: " << errno;
return rv == 0;
}
int TCPClientSocketLibevent::CreateSocket(const addrinfo* ai) {
socket_ = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (socket_ == kInvalidSocket)
return errno;
return SetupSocket();
}
int TCPClientSocketLibevent::SetupSocket() {
if (SetNonBlocking(socket_)) {
const int err = errno;
#ifdef ANDROID
if (valid_uid_)
qtaguid_untagSocket(socket_);
#endif
close(socket_);
socket_ = kInvalidSocket;
return err;
}
// This mirrors the behaviour on Windows. See the comment in
// tcp_client_socket_win.cc after searching for "NODELAY".
DisableNagle(socket_); // If DisableNagle fails, we don't care.
// ANDROID: Disable TCP keep-alive for bug 5226268
// [Browser] http keep-alive packets are sent too frequently to network
#ifndef ANDROID
SetTCPKeepAlive(socket_);
#endif
#ifdef ANDROID
if (valid_uid_)
qtaguid_tagSocket(socket_, geteuid(), calling_uid_);
#endif
return 0;
}
void TCPClientSocketLibevent::LogConnectCompletion(int net_error) {
if (net_error == OK)
UpdateConnectionTypeHistograms(CONNECTION_ANY);
if (net_error != OK) {
net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_CONNECT, net_error);
return;
}
struct sockaddr_storage source_address;
socklen_t addrlen = sizeof(source_address);
int rv = getsockname(
socket_, reinterpret_cast<struct sockaddr*>(&source_address), &addrlen);
if (rv != 0) {
PLOG(ERROR) << "getsockname() [rv: " << rv << "] error: ";
NOTREACHED();
net_log_.EndEventWithNetErrorCode(NetLog::TYPE_TCP_CONNECT, rv);
return;
}
const std::string source_address_str =
NetAddressToStringWithPort(
reinterpret_cast<const struct sockaddr*>(&source_address),
sizeof(source_address));
net_log_.EndEvent(NetLog::TYPE_TCP_CONNECT,
make_scoped_refptr(new NetLogStringParameter(
"source address",
source_address_str)));
}
void TCPClientSocketLibevent::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;
c->Run(rv);
}
void TCPClientSocketLibevent::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;
c->Run(rv);
}
void TCPClientSocketLibevent::DidCompleteConnect() {
DCHECK_EQ(next_connect_state_, CONNECT_STATE_CONNECT_COMPLETE);
// Get the error that connect() completed with.
int os_error = 0;
socklen_t len = sizeof(os_error);
if (getsockopt(socket_, SOL_SOCKET, SO_ERROR, &os_error, &len) < 0)
os_error = errno;
// TODO(eroman): Is this check really necessary?
if (os_error == EINPROGRESS || os_error == EALREADY) {
NOTREACHED(); // This indicates a bug in libevent or our code.
return;
}
connect_os_error_ = os_error;
int rv = DoConnectLoop(MapConnectError(os_error));
if (rv != ERR_IO_PENDING) {
LogConnectCompletion(rv);
DoWriteCallback(rv);
}
}
void TCPClientSocketLibevent::DidCompleteRead() {
int bytes_transferred;
bytes_transferred = HANDLE_EINTR(read(socket_, read_buf_->data(),
read_buf_len_));
int result;
if (bytes_transferred >= 0) {
result = bytes_transferred;
base::StatsCounter read_bytes("tcp.read_bytes");
read_bytes.Add(bytes_transferred);
if (bytes_transferred > 0)
use_history_.set_was_used_to_convey_data();
LogByteTransfer(net_log_, NetLog::TYPE_SOCKET_BYTES_RECEIVED, result,
read_buf_->data());
} else {
result = MapSystemError(errno);
}
if (result != ERR_IO_PENDING) {
read_buf_ = NULL;
read_buf_len_ = 0;
bool ok = read_socket_watcher_.StopWatchingFileDescriptor();
DCHECK(ok);
DoReadCallback(result);
}
}
void TCPClientSocketLibevent::DidCompleteWrite() {
int bytes_transferred;
bytes_transferred = HANDLE_EINTR(write(socket_, write_buf_->data(),
write_buf_len_));
int result;
if (bytes_transferred >= 0) {
result = bytes_transferred;
base::StatsCounter write_bytes("tcp.write_bytes");
write_bytes.Add(bytes_transferred);
if (bytes_transferred > 0)
use_history_.set_was_used_to_convey_data();
LogByteTransfer(net_log_, NetLog::TYPE_SOCKET_BYTES_SENT, result,
write_buf_->data());
} else {
result = MapSystemError(errno);
}
if (result != ERR_IO_PENDING) {
write_buf_ = NULL;
write_buf_len_ = 0;
write_socket_watcher_.StopWatchingFileDescriptor();
DoWriteCallback(result);
}
}
int TCPClientSocketLibevent::GetPeerAddress(AddressList* address) const {
DCHECK(CalledOnValidThread());
DCHECK(address);
if (!IsConnected())
return ERR_SOCKET_NOT_CONNECTED;
address->Copy(current_ai_, false);
return OK;
}
int TCPClientSocketLibevent::GetLocalAddress(IPEndPoint* address) const {
DCHECK(CalledOnValidThread());
DCHECK(address);
if (!IsConnected())
return ERR_SOCKET_NOT_CONNECTED;
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 MapSystemError(errno);
if (!address->FromSockAddr(addr, addr_len))
return ERR_FAILED;
return OK;
}
const BoundNetLog& TCPClientSocketLibevent::NetLog() const {
return net_log_;
}
void TCPClientSocketLibevent::SetSubresourceSpeculation() {
use_history_.set_subresource_speculation();
}
void TCPClientSocketLibevent::SetOmniboxSpeculation() {
use_history_.set_omnibox_speculation();
}
bool TCPClientSocketLibevent::WasEverUsed() const {
return use_history_.was_used_to_convey_data();
}
bool TCPClientSocketLibevent::UsingTCPFastOpen() const {
return use_tcp_fastopen_;
}
} // namespace net