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webrtc / src / 5d9b964705ab1aaa45c12f93977bb19d0df9c5a6 / . / rtc_base / physical_socket_server.cc
blob: bd6a324ca931a36a9f32a470a35e6366ba6dbc87 [file] [log] [blame]
/*
* 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.
*/
#include "rtc_base/physical_socket_server.h"
#if defined(_MSC_VER) && _MSC_VER < 1300
#pragma warning(disable : 4786)
#endif
#ifdef MEMORY_SANITIZER
#include <sanitizer/msan_interface.h>
#endif
#if defined(WEBRTC_POSIX)
#include <fcntl.h>
#include <string.h>
#if defined(WEBRTC_USE_EPOLL)
// "poll" will be used to wait for the signal dispatcher.
#include <poll.h>
#endif
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/time.h>
#include <unistd.h>
#endif
#if defined(WEBRTC_WIN)
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#undef SetPort
#endif
#include <errno.h>
#include <algorithm>
#include <map>
#include "rtc_base/arraysize.h"
#include "rtc_base/byte_order.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/network_monitor.h"
#include "rtc_base/null_socket_server.h"
#include "rtc_base/time_utils.h"
#if defined(WEBRTC_LINUX)
#include <linux/sockios.h>
#endif
#if defined(WEBRTC_WIN)
#define LAST_SYSTEM_ERROR (::GetLastError())
#elif defined(__native_client__) && __native_client__
#define LAST_SYSTEM_ERROR (0)
#elif defined(WEBRTC_POSIX)
#define LAST_SYSTEM_ERROR (errno)
#endif // WEBRTC_WIN
#if defined(WEBRTC_POSIX)
#include <netinet/tcp.h> // for TCP_NODELAY
#define IP_MTU 14 // Until this is integrated from linux/in.h to netinet/in.h
typedef void* SockOptArg;
#endif // WEBRTC_POSIX
#if defined(WEBRTC_POSIX) && !defined(WEBRTC_MAC) && !defined(__native_client__)
int64_t GetSocketRecvTimestamp(int socket) {
struct timeval tv_ioctl;
int ret = ioctl(socket, SIOCGSTAMP, &tv_ioctl);
if (ret != 0)
return -1;
int64_t timestamp =
rtc::kNumMicrosecsPerSec * static_cast<int64_t>(tv_ioctl.tv_sec) +
static_cast<int64_t>(tv_ioctl.tv_usec);
return timestamp;
}
#else
int64_t GetSocketRecvTimestamp(int socket) {
return -1;
}
#endif
#if defined(WEBRTC_WIN)
typedef char* SockOptArg;
#endif
#if defined(WEBRTC_USE_EPOLL)
// POLLRDHUP / EPOLLRDHUP are only defined starting with Linux 2.6.17.
#if !defined(POLLRDHUP)
#define POLLRDHUP 0x2000
#endif
#if !defined(EPOLLRDHUP)
#define EPOLLRDHUP 0x2000
#endif
#endif
namespace rtc {
std::unique_ptr<SocketServer> SocketServer::CreateDefault() {
#if defined(__native_client__)
return std::unique_ptr<SocketServer>(new rtc::NullSocketServer);
#else
return std::unique_ptr<SocketServer>(new rtc::PhysicalSocketServer);
#endif
}
PhysicalSocket::PhysicalSocket(PhysicalSocketServer* ss, SOCKET s)
: ss_(ss),
s_(s),
error_(0),
state_((s == INVALID_SOCKET) ? CS_CLOSED : CS_CONNECTED),
resolver_(nullptr) {
if (s_ != INVALID_SOCKET) {
SetEnabledEvents(DE_READ | DE_WRITE);
int type = SOCK_STREAM;
socklen_t len = sizeof(type);
const int res =
getsockopt(s_, SOL_SOCKET, SO_TYPE, (SockOptArg)&type, &len);
RTC_DCHECK_EQ(0, res);
udp_ = (SOCK_DGRAM == type);
}
}
PhysicalSocket::~PhysicalSocket() {
Close();
}
bool PhysicalSocket::Create(int family, int type) {
Close();
s_ = ::socket(family, type, 0);
udp_ = (SOCK_DGRAM == type);
UpdateLastError();
if (udp_) {
SetEnabledEvents(DE_READ | DE_WRITE);
}
return s_ != INVALID_SOCKET;
}
SocketAddress PhysicalSocket::GetLocalAddress() const {
sockaddr_storage addr_storage = {};
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 {
RTC_LOG(LS_WARNING) << "GetLocalAddress: unable to get local addr, socket="
<< s_;
}
return address;
}
SocketAddress PhysicalSocket::GetRemoteAddress() const {
sockaddr_storage addr_storage = {};
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 {
RTC_LOG(LS_WARNING)
<< "GetRemoteAddress: unable to get remote addr, socket=" << s_;
}
return address;
}
int PhysicalSocket::Bind(const SocketAddress& bind_addr) {
SocketAddress copied_bind_addr = bind_addr;
// If a network binder is available, use it to bind a socket to an interface
// instead of bind(), since this is more reliable on an OS with a weak host
// model.
if (ss_->network_binder() && !bind_addr.IsAnyIP()) {
NetworkBindingResult result =
ss_->network_binder()->BindSocketToNetwork(s_, bind_addr.ipaddr());
if (result == NetworkBindingResult::SUCCESS) {
// Since the network binder handled binding the socket to the desired
// network interface, we don't need to (and shouldn't) include an IP in
// the bind() call; bind() just needs to assign a port.
copied_bind_addr.SetIP(GetAnyIP(copied_bind_addr.ipaddr().family()));
} else if (result == NetworkBindingResult::NOT_IMPLEMENTED) {
RTC_LOG(LS_INFO) << "Can't bind socket to network because "
"network binding is not implemented for this OS.";
} else {
if (bind_addr.IsLoopbackIP()) {
// If we couldn't bind to a loopback IP (which should only happen in
// test scenarios), continue on. This may be expected behavior.
RTC_LOG(LS_VERBOSE) << "Binding socket to loopback address "
<< bind_addr.ipaddr().ToString()
<< " failed; result: " << static_cast<int>(result);
} else {
RTC_LOG(LS_WARNING) << "Binding socket to network address "
<< bind_addr.ipaddr().ToString()
<< " failed; result: " << static_cast<int>(result);
// If a network binding was attempted and failed, we should stop here
// and not try to use the socket. Otherwise, we may end up sending
// packets with an invalid source address.
// See: https://bugs.chromium.org/p/webrtc/issues/detail?id=7026
return -1;
}
}
}
sockaddr_storage addr_storage;
size_t len = copied_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 PhysicalSocket::Connect(const SocketAddress& addr) {
// TODO(pthatcher): 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()) {
RTC_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();
uint8_t events = DE_READ | DE_WRITE;
if (err == 0) {
state_ = CS_CONNECTED;
} else if (IsBlockingError(GetError())) {
state_ = CS_CONNECTING;
events |= DE_CONNECT;
} else {
return SOCKET_ERROR;
}
EnableEvents(events);
return 0;
}
int PhysicalSocket::GetError() const {
CritScope cs(&crit_);
return error_;
}
void PhysicalSocket::SetError(int error) {
CritScope cs(&crit_);
error_ = error;
}
AsyncSocket::ConnState PhysicalSocket::GetState() const {
return state_;
}
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 = DoSend(
s_, reinterpret_cast<const char*>(pv), static_cast<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.
RTC_DCHECK(sent <= static_cast<int>(cb));
if ((sent > 0 && sent < static_cast<int>(cb)) ||
(sent < 0 && IsBlockingError(GetError()))) {
EnableEvents(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 =
DoSendTo(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.
RTC_DCHECK(sent <= static_cast<int>(length));
if ((sent > 0 && sent < static_cast<int>(length)) ||
(sent < 0 && IsBlockingError(GetError()))) {
EnableEvents(DE_WRITE);
}
return sent;
}
int PhysicalSocket::Recv(void* buffer, size_t length, int64_t* timestamp) {
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.
RTC_LOG(LS_WARNING) << "EOF from socket; deferring close event";
// Must turn this back on so that the select() loop will notice the close
// event.
EnableEvents(DE_READ);
SetError(EWOULDBLOCK);
return SOCKET_ERROR;
}
if (timestamp) {
*timestamp = GetSocketRecvTimestamp(s_);
}
UpdateLastError();
int error = GetError();
bool success = (received >= 0) || IsBlockingError(error);
if (udp_ || success) {
EnableEvents(DE_READ);
}
if (!success) {
RTC_LOG_F(LS_VERBOSE) << "Error = " << error;
}
return received;
}
int PhysicalSocket::RecvFrom(void* buffer,
size_t length,
SocketAddress* out_addr,
int64_t* timestamp) {
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);
if (timestamp) {
*timestamp = GetSocketRecvTimestamp(s_);
}
UpdateLastError();
if ((received >= 0) && (out_addr != nullptr))
SocketAddressFromSockAddrStorage(addr_storage, out_addr);
int error = GetError();
bool success = (received >= 0) || IsBlockingError(error);
if (udp_ || success) {
EnableEvents(DE_READ);
}
if (!success) {
RTC_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;
EnableEvents(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.
EnableEvents(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;
SetEnabledEvents(0);
if (resolver_) {
resolver_->Destroy(false);
resolver_ = nullptr;
}
return err;
}
SOCKET PhysicalSocket::DoAccept(SOCKET socket,
sockaddr* addr,
socklen_t* addrlen) {
return ::accept(socket, addr, addrlen);
}
int PhysicalSocket::DoSend(SOCKET socket, const char* buf, int len, int flags) {
return ::send(socket, buf, len, flags);
}
int PhysicalSocket::DoSendTo(SOCKET socket,
const char* buf,
int len,
int flags,
const struct sockaddr* dest_addr,
socklen_t addrlen) {
return ::sendto(socket, buf, len, flags, dest_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
}
void PhysicalSocket::SetEnabledEvents(uint8_t events) {
enabled_events_ = events;
}
void PhysicalSocket::EnableEvents(uint8_t events) {
enabled_events_ |= events;
}
void PhysicalSocket::DisableEvents(uint8_t events) {
enabled_events_ &= ~events;
}
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__)
RTC_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:
RTC_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:
RTC_NOTREACHED();
return -1;
}
return 0;
}
SocketDispatcher::SocketDispatcher(PhysicalSocketServer* ss)
#if defined(WEBRTC_WIN)
: PhysicalSocket(ss),
id_(0),
signal_close_(false)
#else
: PhysicalSocket(ss)
#endif
{
}
SocketDispatcher::SocketDispatcher(SOCKET s, PhysicalSocketServer* ss)
#if defined(WEBRTC_WIN)
: PhysicalSocket(ss, s),
id_(0),
signal_close_(false)
#else
: PhysicalSocket(ss, s)
#endif
{
}
SocketDispatcher::~SocketDispatcher() {
Close();
}
bool SocketDispatcher::Initialize() {
RTC_DCHECK(s_ != INVALID_SOCKET);
// Must be a non-blocking
#if defined(WEBRTC_WIN)
u_long argp = 1;
ioctlsocket(s_, FIONBIO, &argp);
#elif defined(WEBRTC_POSIX)
fcntl(s_, F_SETFL, fcntl(s_, F_GETFL, 0) | O_NONBLOCK);
#endif
#if defined(WEBRTC_IOS)
// iOS may kill sockets when the app is moved to the background
// (specifically, if the app doesn't use the "voip" UIBackgroundMode). When
// we attempt to write to such a socket, SIGPIPE will be raised, which by
// default will terminate the process, which we don't want. By specifying
// this socket option, SIGPIPE will be disabled for the socket.
int value = 1;
::setsockopt(s_, SOL_SOCKET, SO_NOSIGPIPE, &value, sizeof(value));
#endif
ss_->Add(this);
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;
if (!Initialize())
return false;
#if defined(WEBRTC_WIN)
do {
id_ = ++next_id_;
} while (id_ == 0);
#endif
return true;
}
#if defined(WEBRTC_WIN)
WSAEVENT SocketDispatcher::GetWSAEvent() {
return WSA_INVALID_EVENT;
}
SOCKET SocketDispatcher::GetSocket() {
return s_;
}
bool SocketDispatcher::CheckSignalClose() {
if (!signal_close_)
return false;
char ch;
if (recv(s_, &ch, 1, MSG_PEEK) > 0)
return false;
state_ = CS_CLOSED;
signal_close_ = false;
SignalCloseEvent(this, signal_err_);
return true;
}
int SocketDispatcher::next_id_ = 0;
#elif defined(WEBRTC_POSIX)
int SocketDispatcher::GetDescriptor() {
return s_;
}
bool SocketDispatcher::IsDescriptorClosed() {
if (udp_) {
// The MSG_PEEK trick doesn't work for UDP, since (at least in some
// circumstances) it requires reading an entire UDP packet, which would be
// bad for performance here. So, just check whether |s_| has been closed,
// which should be sufficient.
return s_ == INVALID_SOCKET;
}
// 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;
// The normal blocking error; don't log anything.
case EWOULDBLOCK:
// Interrupted system call.
case EINTR:
return false;
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.
RTC_LOG_ERR(LS_WARNING) << "Assuming benign blocking error";
return false;
}
}
}
#endif // WEBRTC_POSIX
uint32_t SocketDispatcher::GetRequestedEvents() {
return enabled_events();
}
void SocketDispatcher::OnPreEvent(uint32_t ff) {
if ((ff & DE_CONNECT) != 0)
state_ = CS_CONNECTED;
#if defined(WEBRTC_WIN)
// We set CS_CLOSED from CheckSignalClose.
#elif defined(WEBRTC_POSIX)
if ((ff & DE_CLOSE) != 0)
state_ = CS_CLOSED;
#endif
}
#if defined(WEBRTC_WIN)
void SocketDispatcher::OnEvent(uint32_t ff, int err) {
int cache_id = id_;
// 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) && (id_ == cache_id)) {
if (ff != DE_CONNECT)
RTC_LOG(LS_VERBOSE) << "Signalled with DE_CONNECT: " << ff;
DisableEvents(DE_CONNECT);
#if !defined(NDEBUG)
dbg_addr_ = "Connected @ ";
dbg_addr_.append(GetRemoteAddress().ToString());
#endif
SignalConnectEvent(this);
}
if (((ff & DE_ACCEPT) != 0) && (id_ == cache_id)) {
DisableEvents(DE_ACCEPT);
SignalReadEvent(this);
}
if ((ff & DE_READ) != 0) {
DisableEvents(DE_READ);
SignalReadEvent(this);
}
if (((ff & DE_WRITE) != 0) && (id_ == cache_id)) {
DisableEvents(DE_WRITE);
SignalWriteEvent(this);
}
if (((ff & DE_CLOSE) != 0) && (id_ == cache_id)) {
signal_close_ = true;
signal_err_ = err;
}
}
#elif defined(WEBRTC_POSIX)
void SocketDispatcher::OnEvent(uint32_t ff, int err) {
#if defined(WEBRTC_USE_EPOLL)
// Remember currently enabled events so we can combine multiple changes
// into one update call later.
// The signal handlers might re-enable events disabled here, so we can't
// keep a list of events to disable at the end of the method. This list
// would not be updated with the events enabled by the signal handlers.
StartBatchedEventUpdates();
#endif
// 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) {
DisableEvents(DE_CONNECT);
SignalConnectEvent(this);
}
if ((ff & DE_ACCEPT) != 0) {
DisableEvents(DE_ACCEPT);
SignalReadEvent(this);
}
if ((ff & DE_READ) != 0) {
DisableEvents(DE_READ);
SignalReadEvent(this);
}
if ((ff & DE_WRITE) != 0) {
DisableEvents(DE_WRITE);
SignalWriteEvent(this);
}
if ((ff & DE_CLOSE) != 0) {
// The socket is now dead to us, so stop checking it.
SetEnabledEvents(0);
SignalCloseEvent(this, err);
}
#if defined(WEBRTC_USE_EPOLL)
FinishBatchedEventUpdates();
#endif
}
#endif // WEBRTC_POSIX
#if defined(WEBRTC_USE_EPOLL)
static int GetEpollEvents(uint32_t ff) {
int events = 0;
if (ff & (DE_READ | DE_ACCEPT)) {
events |= EPOLLIN;
}
if (ff & (DE_WRITE | DE_CONNECT)) {
events |= EPOLLOUT;
}
return events;
}
void SocketDispatcher::StartBatchedEventUpdates() {
RTC_DCHECK_EQ(saved_enabled_events_, -1);
saved_enabled_events_ = enabled_events();
}
void SocketDispatcher::FinishBatchedEventUpdates() {
RTC_DCHECK_NE(saved_enabled_events_, -1);
uint8_t old_events = static_cast<uint8_t>(saved_enabled_events_);
saved_enabled_events_ = -1;
MaybeUpdateDispatcher(old_events);
}
void SocketDispatcher::MaybeUpdateDispatcher(uint8_t old_events) {
if (GetEpollEvents(enabled_events()) != GetEpollEvents(old_events) &&
saved_enabled_events_ == -1) {
ss_->Update(this);
}
}
void SocketDispatcher::SetEnabledEvents(uint8_t events) {
uint8_t old_events = enabled_events();
PhysicalSocket::SetEnabledEvents(events);
MaybeUpdateDispatcher(old_events);
}
void SocketDispatcher::EnableEvents(uint8_t events) {
uint8_t old_events = enabled_events();
PhysicalSocket::EnableEvents(events);
MaybeUpdateDispatcher(old_events);
}
void SocketDispatcher::DisableEvents(uint8_t events) {
uint8_t old_events = enabled_events();
PhysicalSocket::DisableEvents(events);
MaybeUpdateDispatcher(old_events);
}
#endif // WEBRTC_USE_EPOLL
int SocketDispatcher::Close() {
if (s_ == INVALID_SOCKET)
return 0;
#if defined(WEBRTC_WIN)
id_ = 0;
signal_close_ = false;
#endif
ss_->Remove(this);
return PhysicalSocket::Close();
}
#if defined(WEBRTC_POSIX)
class EventDispatcher : public Dispatcher {
public:
EventDispatcher(PhysicalSocketServer* ss) : ss_(ss), fSignaled_(false) {
if (pipe(afd_) < 0)
RTC_LOG(LERROR) << "pipe failed";
ss_->Add(this);
}
~EventDispatcher() override {
ss_->Remove(this);
close(afd_[0]);
close(afd_[1]);
}
virtual void Signal() {
CritScope cs(&crit_);
if (!fSignaled_) {
const uint8_t b[1] = {0};
const ssize_t res = write(afd_[1], b, sizeof(b));
RTC_DCHECK_EQ(1, res);
fSignaled_ = true;
}
}
uint32_t GetRequestedEvents() override { return DE_READ; }
void OnPreEvent(uint32_t ff) override {
// It is not possible to perfectly emulate an auto-resetting event with
// pipes. This simulates it by resetting before the event is handled.
CritScope cs(&crit_);
if (fSignaled_) {
uint8_t b[4]; // Allow for reading more than 1 byte, but expect 1.
const ssize_t res = read(afd_[0], b, sizeof(b));
RTC_DCHECK_EQ(1, res);
fSignaled_ = false;
}
}
void OnEvent(uint32_t ff, int err) override { RTC_NOTREACHED(); }
int GetDescriptor() override { return afd_[0]; }
bool IsDescriptorClosed() override { return false; }
private:
PhysicalSocketServer* ss_;
int afd_[2];
bool fSignaled_;
CriticalSection crit_;
};
// These two classes use the self-pipe trick to deliver POSIX signals to our
// select loop. This is the only safe, reliable, cross-platform way to do
// non-trivial things with a POSIX signal in an event-driven program (until
// proper pselect() implementations become ubiquitous).
class PosixSignalHandler {
public:
// POSIX only specifies 32 signals, but in principle the system might have
// more and the programmer might choose to use them, so we size our array
// for 128.
static const int kNumPosixSignals = 128;
// There is just a single global instance. (Signal handlers do not get any
// sort of user-defined void * parameter, so they can't access anything that
// isn't global.)
static PosixSignalHandler* Instance() {
static PosixSignalHandler* const instance = new PosixSignalHandler();
return instance;
}
// Returns true if the given signal number is set.
bool IsSignalSet(int signum) const {
RTC_DCHECK(signum < static_cast<int>(arraysize(received_signal_)));
if (signum < static_cast<int>(arraysize(received_signal_))) {
return received_signal_[signum];
} else {
return false;
}
}
// Clears the given signal number.
void ClearSignal(int signum) {
RTC_DCHECK(signum < static_cast<int>(arraysize(received_signal_)));
if (signum < static_cast<int>(arraysize(received_signal_))) {
received_signal_[signum] = false;
}
}
// Returns the file descriptor to monitor for signal events.
int GetDescriptor() const { return afd_[0]; }
// This is called directly from our real signal handler, so it must be
// signal-handler-safe. That means it cannot assume anything about the
// user-level state of the process, since the handler could be executed at any
// time on any thread.
void OnPosixSignalReceived(int signum) {
if (signum >= static_cast<int>(arraysize(received_signal_))) {
// We don't have space in our array for this.
return;
}
// Set a flag saying we've seen this signal.
received_signal_[signum] = true;
// Notify application code that we got a signal.
const uint8_t b[1] = {0};
if (-1 == write(afd_[1], b, sizeof(b))) {
// Nothing we can do here. If there's an error somehow then there's
// nothing we can safely do from a signal handler.
// No, we can't even safely log it.
// But, we still have to check the return value here. Otherwise,
// GCC 4.4.1 complains ignoring return value. Even (void) doesn't help.
return;
}
}
private:
PosixSignalHandler() {
if (pipe(afd_) < 0) {
RTC_LOG_ERR(LS_ERROR) << "pipe failed";
return;
}
if (fcntl(afd_[0], F_SETFL, O_NONBLOCK) < 0) {
RTC_LOG_ERR(LS_WARNING) << "fcntl #1 failed";
}
if (fcntl(afd_[1], F_SETFL, O_NONBLOCK) < 0) {
RTC_LOG_ERR(LS_WARNING) << "fcntl #2 failed";
}
memset(const_cast<void*>(static_cast<volatile void*>(received_signal_)), 0,
sizeof(received_signal_));
}
~PosixSignalHandler() {
int fd1 = afd_[0];
int fd2 = afd_[1];
// We clobber the stored file descriptor numbers here or else in principle
// a signal that happens to be delivered during application termination
// could erroneously write a zero byte to an unrelated file handle in
// OnPosixSignalReceived() if some other file happens to be opened later
// during shutdown and happens to be given the same file descriptor number
// as our pipe had. Unfortunately even with this precaution there is still a
// race where that could occur if said signal happens to be handled
// concurrently with this code and happens to have already read the value of
// afd_[1] from memory before we clobber it, but that's unlikely.
afd_[0] = -1;
afd_[1] = -1;
close(fd1);
close(fd2);
}
int afd_[2];
// These are boolean flags that will be set in our signal handler and read
// and cleared from Wait(). There is a race involved in this, but it is
// benign. The signal handler sets the flag before signaling the pipe, so
// we'll never end up blocking in select() while a flag is still true.
// However, if two of the same signal arrive close to each other then it's
// possible that the second time the handler may set the flag while it's still
// true, meaning that signal will be missed. But the first occurrence of it
// will still be handled, so this isn't a problem.
// Volatile is not necessary here for correctness, but this data _is_ volatile
// so I've marked it as such.
volatile uint8_t received_signal_[kNumPosixSignals];
};
class PosixSignalDispatcher : public Dispatcher {
public:
PosixSignalDispatcher(PhysicalSocketServer* owner) : owner_(owner) {
owner_->Add(this);
}
~PosixSignalDispatcher() override { owner_->Remove(this); }
uint32_t GetRequestedEvents() override { return DE_READ; }
void OnPreEvent(uint32_t ff) override {
// Events might get grouped if signals come very fast, so we read out up to
// 16 bytes to make sure we keep the pipe empty.
uint8_t b[16];
ssize_t ret = read(GetDescriptor(), b, sizeof(b));
if (ret < 0) {
RTC_LOG_ERR(LS_WARNING) << "Error in read()";
} else if (ret == 0) {
RTC_LOG(LS_WARNING) << "Should have read at least one byte";
}
}
void OnEvent(uint32_t ff, int err) override {
for (int signum = 0; signum < PosixSignalHandler::kNumPosixSignals;
++signum) {
if (PosixSignalHandler::Instance()->IsSignalSet(signum)) {
PosixSignalHandler::Instance()->ClearSignal(signum);
HandlerMap::iterator i = handlers_.find(signum);
if (i == handlers_.end()) {
// This can happen if a signal is delivered to our process at around
// the same time as we unset our handler for it. It is not an error
// condition, but it's unusual enough to be worth logging.
RTC_LOG(LS_INFO) << "Received signal with no handler: " << signum;
} else {
// Otherwise, execute our handler.
(*i->second)(signum);
}
}
}
}
int GetDescriptor() override {
return PosixSignalHandler::Instance()->GetDescriptor();
}
bool IsDescriptorClosed() override { return false; }
void SetHandler(int signum, void (*handler)(int)) {
handlers_[signum] = handler;
}
void ClearHandler(int signum) { handlers_.erase(signum); }
bool HasHandlers() { return !handlers_.empty(); }
private:
typedef std::map<int, void (*)(int)> HandlerMap;
HandlerMap handlers_;
// Our owner.
PhysicalSocketServer* owner_;
};
#endif // WEBRTC_POSIX
#if defined(WEBRTC_WIN)
static uint32_t FlagsToEvents(uint32_t events) {
uint32_t ffFD = FD_CLOSE;
if (events & DE_READ)
ffFD |= FD_READ;
if (events & DE_WRITE)
ffFD |= FD_WRITE;
if (events & DE_CONNECT)
ffFD |= FD_CONNECT;
if (events & DE_ACCEPT)
ffFD |= FD_ACCEPT;
return ffFD;
}
class EventDispatcher : public Dispatcher {
public:
EventDispatcher(PhysicalSocketServer* ss) : ss_(ss) {
hev_ = WSACreateEvent();
if (hev_) {
ss_->Add(this);
}
}
~EventDispatcher() override {
if (hev_ != nullptr) {
ss_->Remove(this);
WSACloseEvent(hev_);
hev_ = nullptr;
}
}
virtual void Signal() {
if (hev_ != nullptr)
WSASetEvent(hev_);
}
uint32_t GetRequestedEvents() override { return 0; }
void OnPreEvent(uint32_t ff) override { WSAResetEvent(hev_); }
void OnEvent(uint32_t ff, int err) override {}
WSAEVENT GetWSAEvent() override { return hev_; }
SOCKET GetSocket() override { return INVALID_SOCKET; }
bool CheckSignalClose() override { return false; }
private:
PhysicalSocketServer* ss_;
WSAEVENT hev_;
};
#endif // WEBRTC_WIN
// Sets the value of a boolean value to false when signaled.
class Signaler : public EventDispatcher {
public:
Signaler(PhysicalSocketServer* ss, bool* pf) : EventDispatcher(ss), pf_(pf) {}
~Signaler() override {}
void OnEvent(uint32_t ff, int err) override {
if (pf_)
*pf_ = false;
}
private:
bool* pf_;
};
PhysicalSocketServer::PhysicalSocketServer() : fWait_(false) {
#if defined(WEBRTC_USE_EPOLL)
// Since Linux 2.6.8, the size argument is ignored, but must be greater than
// zero. Before that the size served as hint to the kernel for the amount of
// space to initially allocate in internal data structures.
epoll_fd_ = epoll_create(FD_SETSIZE);
if (epoll_fd_ == -1) {
// Not an error, will fall back to "select" below.
RTC_LOG_E(LS_WARNING, EN, errno) << "epoll_create";
epoll_fd_ = INVALID_SOCKET;
}
#endif
signal_wakeup_ = new Signaler(this, &fWait_);
#if defined(WEBRTC_WIN)
socket_ev_ = WSACreateEvent();
#endif
}
PhysicalSocketServer::~PhysicalSocketServer() {
#if defined(WEBRTC_WIN)
WSACloseEvent(socket_ev_);
#endif
#if defined(WEBRTC_POSIX)
signal_dispatcher_.reset();
#endif
delete signal_wakeup_;
#if defined(WEBRTC_USE_EPOLL)
if (epoll_fd_ != INVALID_SOCKET) {
close(epoll_fd_);
}
#endif
RTC_DCHECK(dispatchers_.empty());
}
void PhysicalSocketServer::WakeUp() {
signal_wakeup_->Signal();
}
Socket* PhysicalSocketServer::CreateSocket(int family, int type) {
PhysicalSocket* socket = new PhysicalSocket(this);
if (socket->Create(family, type)) {
return socket;
} else {
delete socket;
return nullptr;
}
}
AsyncSocket* PhysicalSocketServer::CreateAsyncSocket(int family, int type) {
SocketDispatcher* dispatcher = new SocketDispatcher(this);
if (dispatcher->Create(family, type)) {
return dispatcher;
} else {
delete dispatcher;
return nullptr;
}
}
AsyncSocket* PhysicalSocketServer::WrapSocket(SOCKET s) {
SocketDispatcher* dispatcher = new SocketDispatcher(s, this);
if (dispatcher->Initialize()) {
return dispatcher;
} else {
delete dispatcher;
return nullptr;
}
}
void PhysicalSocketServer::Add(Dispatcher* pdispatcher) {
CritScope cs(&crit_);
if (processing_dispatchers_) {
// A dispatcher is being added while a "Wait" call is processing the
// list of socket events.
// Defer adding to "dispatchers_" set until processing is done to avoid
// invalidating the iterator in "Wait".
pending_remove_dispatchers_.erase(pdispatcher);
pending_add_dispatchers_.insert(pdispatcher);
} else {
dispatchers_.insert(pdispatcher);
}
#if defined(WEBRTC_USE_EPOLL)
if (epoll_fd_ != INVALID_SOCKET) {
AddEpoll(pdispatcher);
}
#endif // WEBRTC_USE_EPOLL
}
void PhysicalSocketServer::Remove(Dispatcher* pdispatcher) {
CritScope cs(&crit_);
if (processing_dispatchers_) {
// A dispatcher is being removed while a "Wait" call is processing the
// list of socket events.
// Defer removal from "dispatchers_" set until processing is done to avoid
// invalidating the iterator in "Wait".
if (!pending_add_dispatchers_.erase(pdispatcher) &&
dispatchers_.find(pdispatcher) == dispatchers_.end()) {
RTC_LOG(LS_WARNING) << "PhysicalSocketServer asked to remove a unknown "
"dispatcher, potentially from a duplicate call to "
"Add.";
return;
}
pending_remove_dispatchers_.insert(pdispatcher);
} else if (!dispatchers_.erase(pdispatcher)) {
RTC_LOG(LS_WARNING)
<< "PhysicalSocketServer asked to remove a unknown "
"dispatcher, potentially from a duplicate call to Add.";
return;
}
#if defined(WEBRTC_USE_EPOLL)
if (epoll_fd_ != INVALID_SOCKET) {
RemoveEpoll(pdispatcher);
}
#endif // WEBRTC_USE_EPOLL
}
void PhysicalSocketServer::Update(Dispatcher* pdispatcher) {
#if defined(WEBRTC_USE_EPOLL)
if (epoll_fd_ == INVALID_SOCKET) {
return;
}
CritScope cs(&crit_);
if (dispatchers_.find(pdispatcher) == dispatchers_.end()) {
return;
}
UpdateEpoll(pdispatcher);
#endif
}
void PhysicalSocketServer::AddRemovePendingDispatchers() {
if (!pending_add_dispatchers_.empty()) {
for (Dispatcher* pdispatcher : pending_add_dispatchers_) {
dispatchers_.insert(pdispatcher);
}
pending_add_dispatchers_.clear();
}
if (!pending_remove_dispatchers_.empty()) {
for (Dispatcher* pdispatcher : pending_remove_dispatchers_) {
dispatchers_.erase(pdispatcher);
}
pending_remove_dispatchers_.clear();
}
}
#if defined(WEBRTC_POSIX)
bool PhysicalSocketServer::Wait(int cmsWait, bool process_io) {
#if defined(WEBRTC_USE_EPOLL)
// We don't keep a dedicated "epoll" descriptor containing only the non-IO
// (i.e. signaling) dispatcher, so "poll" will be used instead of the default
// "select" to support sockets larger than FD_SETSIZE.
if (!process_io) {
return WaitPoll(cmsWait, signal_wakeup_);
} else if (epoll_fd_ != INVALID_SOCKET) {
return WaitEpoll(cmsWait);
}
#endif
return WaitSelect(cmsWait, process_io);
}
static void ProcessEvents(Dispatcher* dispatcher,
bool readable,
bool writable,
bool check_error) {
int errcode = 0;
// TODO(pthatcher): Should we set errcode if getsockopt fails?
if (check_error) {
socklen_t len = sizeof(errcode);
::getsockopt(dispatcher->GetDescriptor(), SOL_SOCKET, SO_ERROR, &errcode,
&len);
}
uint32_t ff = 0;
// Check readable descriptors. If we're waiting on an accept, signal
// that. Otherwise we're waiting for data, check to see if we're
// readable or really closed.
// TODO(pthatcher): Only peek at TCP descriptors.
if (readable) {
if (dispatcher->GetRequestedEvents() & DE_ACCEPT) {
ff |= DE_ACCEPT;
} else if (errcode || dispatcher->IsDescriptorClosed()) {
ff |= DE_CLOSE;
} else {
ff |= DE_READ;
}
}
// Check writable descriptors. If we're waiting on a connect, detect
// success versus failure by the reaped error code.
if (writable) {
if (dispatcher->GetRequestedEvents() & DE_CONNECT) {
if (!errcode) {
ff |= DE_CONNECT;
} else {
ff |= DE_CLOSE;
}
} else {
ff |= DE_WRITE;
}
}
// Tell the descriptor about the event.
if (ff != 0) {
dispatcher->OnPreEvent(ff);
dispatcher->OnEvent(ff, errcode);
}
}
bool PhysicalSocketServer::WaitSelect(int cmsWait, bool process_io) {
// Calculate timing information
struct timeval* ptvWait = nullptr;
struct timeval tvWait;
int64_t stop_us;
if (cmsWait != kForever) {
// Calculate wait timeval
tvWait.tv_sec = cmsWait / 1000;
tvWait.tv_usec = (cmsWait % 1000) * 1000;
ptvWait = &tvWait;
// Calculate when to return
stop_us = rtc::TimeMicros() + cmsWait * 1000;
}
// Zero all fd_sets. Don't need to do this inside the loop since
// select() zeros the descriptors not signaled
fd_set fdsRead;
FD_ZERO(&fdsRead);
fd_set fdsWrite;
FD_ZERO(&fdsWrite);
// Explicitly unpoison these FDs on MemorySanitizer which doesn't handle the
// inline assembly in FD_ZERO.
// http://crbug.com/344505
#ifdef MEMORY_SANITIZER
__msan_unpoison(&fdsRead, sizeof(fdsRead));
__msan_unpoison(&fdsWrite, sizeof(fdsWrite));
#endif
fWait_ = true;
while (fWait_) {
int fdmax = -1;
{
CritScope cr(&crit_);
// TODO(jbauch): Support re-entrant waiting.
RTC_DCHECK(!processing_dispatchers_);
for (Dispatcher* pdispatcher : dispatchers_) {
// Query dispatchers for read and write wait state
RTC_DCHECK(pdispatcher);
if (!process_io && (pdispatcher != signal_wakeup_))
continue;
int fd = pdispatcher->GetDescriptor();
// "select"ing a file descriptor that is equal to or larger than
// FD_SETSIZE will result in undefined behavior.
RTC_DCHECK_LT(fd, FD_SETSIZE);
if (fd > fdmax)
fdmax = fd;
uint32_t ff = pdispatcher->GetRequestedEvents();
if (ff & (DE_READ | DE_ACCEPT))
FD_SET(fd, &fdsRead);
if (ff & (DE_WRITE | DE_CONNECT))
FD_SET(fd, &fdsWrite);
}
}
// Wait then call handlers as appropriate
// < 0 means error
// 0 means timeout
// > 0 means count of descriptors ready
int n = select(fdmax + 1, &fdsRead, &fdsWrite, nullptr, ptvWait);
// If error, return error.
if (n < 0) {
if (errno != EINTR) {
RTC_LOG_E(LS_ERROR, EN, errno) << "select";
return false;
}
// Else ignore the error and keep going. If this EINTR was for one of the
// signals managed by this PhysicalSocketServer, the
// PosixSignalDeliveryDispatcher will be in the signaled state in the next
// iteration.
} else if (n == 0) {
// If timeout, return success
return true;
} else {
// We have signaled descriptors
CritScope cr(&crit_);
processing_dispatchers_ = true;
for (Dispatcher* pdispatcher : dispatchers_) {
int fd = pdispatcher->GetDescriptor();
bool readable = FD_ISSET(fd, &fdsRead);
if (readable) {
FD_CLR(fd, &fdsRead);
}
bool writable = FD_ISSET(fd, &fdsWrite);
if (writable) {
FD_CLR(fd, &fdsWrite);
}
// The error code can be signaled through reads or writes.
ProcessEvents(pdispatcher, readable, writable, readable || writable);
}
processing_dispatchers_ = false;
// Process deferred dispatchers that have been added/removed while the
// events were handled above.
AddRemovePendingDispatchers();
}
// Recalc the time remaining to wait. Doing it here means it doesn't get
// calced twice the first time through the loop
if (ptvWait) {
ptvWait->tv_sec = 0;
ptvWait->tv_usec = 0;
int64_t time_left_us = stop_us - rtc::TimeMicros();
if (time_left_us > 0) {
ptvWait->tv_sec = time_left_us / rtc::kNumMicrosecsPerSec;
ptvWait->tv_usec = time_left_us % rtc::kNumMicrosecsPerSec;
}
}
}
return true;
}
#if defined(WEBRTC_USE_EPOLL)
// Initial number of events to process with one call to "epoll_wait".
static const size_t kInitialEpollEvents = 128;
// Maximum number of events to process with one call to "epoll_wait".
static const size_t kMaxEpollEvents = 8192;
void PhysicalSocketServer::AddEpoll(Dispatcher* pdispatcher) {
RTC_DCHECK(epoll_fd_ != INVALID_SOCKET);
int fd = pdispatcher->GetDescriptor();
RTC_DCHECK(fd != INVALID_SOCKET);
if (fd == INVALID_SOCKET) {
return;
}
struct epoll_event event = {0};
event.events = GetEpollEvents(pdispatcher->GetRequestedEvents());
event.data.ptr = pdispatcher;
int err = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, fd, &event);
RTC_DCHECK_EQ(err, 0);
if (err == -1) {
RTC_LOG_E(LS_ERROR, EN, errno) << "epoll_ctl EPOLL_CTL_ADD";
}
}
void PhysicalSocketServer::RemoveEpoll(Dispatcher* pdispatcher) {
RTC_DCHECK(epoll_fd_ != INVALID_SOCKET);
int fd = pdispatcher->GetDescriptor();
RTC_DCHECK(fd != INVALID_SOCKET);
if (fd == INVALID_SOCKET) {
return;
}
struct epoll_event event = {0};
int err = epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, fd, &event);
RTC_DCHECK(err == 0 || errno == ENOENT);
if (err == -1) {
if (errno == ENOENT) {
// Socket has already been closed.
RTC_LOG_E(LS_VERBOSE, EN, errno) << "epoll_ctl EPOLL_CTL_DEL";
} else {
RTC_LOG_E(LS_ERROR, EN, errno) << "epoll_ctl EPOLL_CTL_DEL";
}
}
}
void PhysicalSocketServer::UpdateEpoll(Dispatcher* pdispatcher) {
RTC_DCHECK(epoll_fd_ != INVALID_SOCKET);
int fd = pdispatcher->GetDescriptor();
RTC_DCHECK(fd != INVALID_SOCKET);
if (fd == INVALID_SOCKET) {
return;
}
struct epoll_event event = {0};
event.events = GetEpollEvents(pdispatcher->GetRequestedEvents());
event.data.ptr = pdispatcher;
int err = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, fd, &event);
RTC_DCHECK_EQ(err, 0);
if (err == -1) {
RTC_LOG_E(LS_ERROR, EN, errno) << "epoll_ctl EPOLL_CTL_MOD";
}
}
bool PhysicalSocketServer::WaitEpoll(int cmsWait) {
RTC_DCHECK(epoll_fd_ != INVALID_SOCKET);
int64_t tvWait = -1;
int64_t tvStop = -1;
if (cmsWait != kForever) {
tvWait = cmsWait;
tvStop = TimeAfter(cmsWait);
}
if (epoll_events_.empty()) {
// The initial space to receive events is created only if epoll is used.
epoll_events_.resize(kInitialEpollEvents);
}
fWait_ = true;
while (fWait_) {
// Wait then call handlers as appropriate
// < 0 means error
// 0 means timeout
// > 0 means count of descriptors ready
int n = epoll_wait(epoll_fd_, &epoll_events_[0],
static_cast<int>(epoll_events_.size()),
static_cast<int>(tvWait));
if (n < 0) {
if (errno != EINTR) {
RTC_LOG_E(LS_ERROR, EN, errno) << "epoll";
return false;
}
// Else ignore the error and keep going. If this EINTR was for one of the
// signals managed by this PhysicalSocketServer, the
// PosixSignalDeliveryDispatcher will be in the signaled state in the next
// iteration.
} else if (n == 0) {
// If timeout, return success
return true;
} else {
// We have signaled descriptors
CritScope cr(&crit_);
for (int i = 0; i < n; ++i) {
const epoll_event& event = epoll_events_[i];
Dispatcher* pdispatcher = static_cast<Dispatcher*>(event.data.ptr);
if (dispatchers_.find(pdispatcher) == dispatchers_.end()) {
// The dispatcher for this socket no longer exists.
continue;
}
bool readable = (event.events & (EPOLLIN | EPOLLPRI));
bool writable = (event.events & EPOLLOUT);
bool check_error = (event.events & (EPOLLRDHUP | EPOLLERR | EPOLLHUP));
ProcessEvents(pdispatcher, readable, writable, check_error);
}
}
if (static_cast<size_t>(n) == epoll_events_.size() &&
epoll_events_.size() < kMaxEpollEvents) {
// We used the complete space to receive events, increase size for future
// iterations.
epoll_events_.resize(std::max(epoll_events_.size() * 2, kMaxEpollEvents));
}
if (cmsWait != kForever) {
tvWait = TimeDiff(tvStop, TimeMillis());
if (tvWait < 0) {
// Return success on timeout.
return true;
}
}
}
return true;
}
bool PhysicalSocketServer::WaitPoll(int cmsWait, Dispatcher* dispatcher) {
RTC_DCHECK(dispatcher);
int64_t tvWait = -1;
int64_t tvStop = -1;
if (cmsWait != kForever) {
tvWait = cmsWait;
tvStop = TimeAfter(cmsWait);
}
fWait_ = true;
struct pollfd fds = {0};
int fd = dispatcher->GetDescriptor();
fds.fd = fd;
while (fWait_) {
uint32_t ff = dispatcher->GetRequestedEvents();
fds.events = 0;
if (ff & (DE_READ | DE_ACCEPT)) {
fds.events |= POLLIN;
}
if (ff & (DE_WRITE | DE_CONNECT)) {
fds.events |= POLLOUT;
}
fds.revents = 0;
// Wait then call handlers as appropriate
// < 0 means error
// 0 means timeout
// > 0 means count of descriptors ready
int n = poll(&fds, 1, static_cast<int>(tvWait));
if (n < 0) {
if (errno != EINTR) {
RTC_LOG_E(LS_ERROR, EN, errno) << "poll";
return false;
}
// Else ignore the error and keep going. If this EINTR was for one of the
// signals managed by this PhysicalSocketServer, the
// PosixSignalDeliveryDispatcher will be in the signaled state in the next
// iteration.
} else if (n == 0) {
// If timeout, return success
return true;
} else {
// We have signaled descriptors (should only be the passed dispatcher).
RTC_DCHECK_EQ(n, 1);
RTC_DCHECK_EQ(fds.fd, fd);
bool readable = (fds.revents & (POLLIN | POLLPRI));
bool writable = (fds.revents & POLLOUT);
bool check_error = (fds.revents & (POLLRDHUP | POLLERR | POLLHUP));
ProcessEvents(dispatcher, readable, writable, check_error);
}
if (cmsWait != kForever) {
tvWait = TimeDiff(tvStop, TimeMillis());
if (tvWait < 0) {
// Return success on timeout.
return true;
}
}
}
return true;
}
#endif // WEBRTC_USE_EPOLL
static void GlobalSignalHandler(int signum) {
PosixSignalHandler::Instance()->OnPosixSignalReceived(signum);
}
bool PhysicalSocketServer::SetPosixSignalHandler(int signum,
void (*handler)(int)) {
// If handler is SIG_IGN or SIG_DFL then clear our user-level handler,
// otherwise set one.
if (handler == SIG_IGN || handler == SIG_DFL) {
if (!InstallSignal(signum, handler)) {
return false;
}
if (signal_dispatcher_) {
signal_dispatcher_->ClearHandler(signum);
if (!signal_dispatcher_->HasHandlers()) {
signal_dispatcher_.reset();
}
}
} else {
if (!signal_dispatcher_) {
signal_dispatcher_.reset(new PosixSignalDispatcher(this));
}
signal_dispatcher_->SetHandler(signum, handler);
if (!InstallSignal(signum, &GlobalSignalHandler)) {
return false;
}
}
return true;
}
Dispatcher* PhysicalSocketServer::signal_dispatcher() {
return signal_dispatcher_.get();
}
bool PhysicalSocketServer::InstallSignal(int signum, void (*handler)(int)) {
struct sigaction act;
// It doesn't really matter what we set this mask to.
if (sigemptyset(&act.sa_mask) != 0) {
RTC_LOG_ERR(LS_ERROR) << "Couldn't set mask";
return false;
}
act.sa_handler = handler;
#if !defined(__native_client__)
// Use SA_RESTART so that our syscalls don't get EINTR, since we don't need it
// and it's a nuisance. Though some syscalls still return EINTR and there's no
// real standard for which ones. :(
act.sa_flags = SA_RESTART;
#else
act.sa_flags = 0;
#endif
if (sigaction(signum, &act, nullptr) != 0) {
RTC_LOG_ERR(LS_ERROR) << "Couldn't set sigaction";
return false;
}
return true;
}
#endif // WEBRTC_POSIX
#if defined(WEBRTC_WIN)
bool PhysicalSocketServer::Wait(int cmsWait, bool process_io) {
int64_t cmsTotal = cmsWait;
int64_t cmsElapsed = 0;
int64_t msStart = Time();
fWait_ = true;
while (fWait_) {
std::vector<WSAEVENT> events;
std::vector<Dispatcher*> event_owners;
events.push_back(socket_ev_);
{
CritScope cr(&crit_);
// TODO(jbauch): Support re-entrant waiting.
RTC_DCHECK(!processing_dispatchers_);
// Calling "CheckSignalClose" might remove a closed dispatcher from the
// set. This must be deferred to prevent invalidating the iterator.
processing_dispatchers_ = true;
for (Dispatcher* disp : dispatchers_) {
if (!process_io && (disp != signal_wakeup_))
continue;
SOCKET s = disp->GetSocket();
if (disp->CheckSignalClose()) {
// We just signalled close, don't poll this socket
} else if (s != INVALID_SOCKET) {
WSAEventSelect(s, events[0],
FlagsToEvents(disp->GetRequestedEvents()));
} else {
events.push_back(disp->GetWSAEvent());
event_owners.push_back(disp);
}
}
processing_dispatchers_ = false;
// Process deferred dispatchers that have been added/removed while the
// events were handled above.
AddRemovePendingDispatchers();
}
// Which is shorter, the delay wait or the asked wait?
int64_t cmsNext;
if (cmsWait == kForever) {
cmsNext = cmsWait;
} else {
cmsNext = std::max<int64_t>(0, cmsTotal - cmsElapsed);
}
// Wait for one of the events to signal
DWORD dw =
WSAWaitForMultipleEvents(static_cast<DWORD>(events.size()), &events[0],
false, static_cast<DWORD>(cmsNext), false);
if (dw == WSA_WAIT_FAILED) {
// Failed?
// TODO(pthatcher): need a better strategy than this!
WSAGetLastError();
RTC_NOTREACHED();
return false;
} else if (dw == WSA_WAIT_TIMEOUT) {
// Timeout?
return true;
} else {
// Figure out which one it is and call it
CritScope cr(&crit_);
int index = dw - WSA_WAIT_EVENT_0;
if (index > 0) {
--index; // The first event is the socket event
Dispatcher* disp = event_owners[index];
// The dispatcher could have been removed while waiting for events.
if (dispatchers_.find(disp) != dispatchers_.end()) {
disp->OnPreEvent(0);
disp->OnEvent(0, 0);
}
} else if (process_io) {
processing_dispatchers_ = true;
for (Dispatcher* disp : dispatchers_) {
SOCKET s = disp->GetSocket();
if (s == INVALID_SOCKET)
continue;
WSANETWORKEVENTS wsaEvents;
int err = WSAEnumNetworkEvents(s, events[0], &wsaEvents);
if (err == 0) {
{
if ((wsaEvents.lNetworkEvents & FD_READ) &&
wsaEvents.iErrorCode[FD_READ_BIT] != 0) {
RTC_LOG(WARNING)
<< "PhysicalSocketServer got FD_READ_BIT error "
<< wsaEvents.iErrorCode[FD_READ_BIT];
}
if ((wsaEvents.lNetworkEvents & FD_WRITE) &&
wsaEvents.iErrorCode[FD_WRITE_BIT] != 0) {
RTC_LOG(WARNING)
<< "PhysicalSocketServer got FD_WRITE_BIT error "
<< wsaEvents.iErrorCode[FD_WRITE_BIT];
}
if ((wsaEvents.lNetworkEvents & FD_CONNECT) &&
wsaEvents.iErrorCode[FD_CONNECT_BIT] != 0) {
RTC_LOG(WARNING)
<< "PhysicalSocketServer got FD_CONNECT_BIT error "
<< wsaEvents.iErrorCode[FD_CONNECT_BIT];
}
if ((wsaEvents.lNetworkEvents & FD_ACCEPT) &&
wsaEvents.iErrorCode[FD_ACCEPT_BIT] != 0) {
RTC_LOG(WARNING)
<< "PhysicalSocketServer got FD_ACCEPT_BIT error "
<< wsaEvents.iErrorCode[FD_ACCEPT_BIT];
}
if ((wsaEvents.lNetworkEvents & FD_CLOSE) &&
wsaEvents.iErrorCode[FD_CLOSE_BIT] != 0) {
RTC_LOG(WARNING)
<< "PhysicalSocketServer got FD_CLOSE_BIT error "
<< wsaEvents.iErrorCode[FD_CLOSE_BIT];
}
}
uint32_t ff = 0;
int errcode = 0;
if (wsaEvents.lNetworkEvents & FD_READ)
ff |= DE_READ;
if (wsaEvents.lNetworkEvents & FD_WRITE)
ff |= DE_WRITE;
if (wsaEvents.lNetworkEvents & FD_CONNECT) {
if (wsaEvents.iErrorCode[FD_CONNECT_BIT] == 0) {
ff |= DE_CONNECT;
} else {
ff |= DE_CLOSE;
errcode = wsaEvents.iErrorCode[FD_CONNECT_BIT];
}
}
if (wsaEvents.lNetworkEvents & FD_ACCEPT)
ff |= DE_ACCEPT;
if (wsaEvents.lNetworkEvents & FD_CLOSE) {
ff |= DE_CLOSE;
errcode = wsaEvents.iErrorCode[FD_CLOSE_BIT];
}
if (ff != 0) {
disp->OnPreEvent(ff);
disp->OnEvent(ff, errcode);
}
}
}
processing_dispatchers_ = false;
// Process deferred dispatchers that have been added/removed while the
// events were handled above.
AddRemovePendingDispatchers();
}
// Reset the network event until new activity occurs
WSAResetEvent(socket_ev_);
}
// Break?
if (!fWait_)
break;
cmsElapsed = TimeSince(msStart);
if ((cmsWait != kForever) && (cmsElapsed >= cmsWait)) {
break;
}
}
// Done
return true;
}
#endif // WEBRTC_WIN
} // namespace rtc