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webrtc / src / 8f29b42670c88b3f0eda0f297ad254a0822ac860 / . / rtc_base / physical_socket_server.cc
blob: be7d9680e43da89f33f650e1ede4b3760e9d3a93 [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"
#include <cstdint>
#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>
#elif defined(WEBRTC_USE_POLL)
#include <poll.h>
#endif
#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/synchronization/mutex.h"
#include "rtc_base/time_utils.h"
#include "system_wrappers/include/field_trial.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 {
class ScopedSetTrue {
public:
ScopedSetTrue(bool* value) : value_(value) {
RTC_DCHECK(!*value_);
*value_ = true;
}
~ScopedSetTrue() { *value_ = false; }
private:
bool* value_;
};
// Returns true if the the client is in the experiment to get timestamps
// from the socket implementation.
bool IsScmTimeStampExperimentEnabled() {
return webrtc::field_trial::IsEnabled("WebRTC-SCM-Timestamp");
}
} // namespace
namespace rtc {
PhysicalSocket::PhysicalSocket(PhysicalSocketServer* ss, SOCKET s)
: ss_(ss),
s_(s),
error_(0),
state_((s == INVALID_SOCKET) ? CS_CLOSED : CS_CONNECTED),
resolver_(nullptr),
read_scm_timestamp_experiment_(IsScmTimeStampExperimentEnabled()) {
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);
family_ = family;
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"
<< " failed; result: " << static_cast<int>(result);
} else {
RTC_LOG(LS_WARNING) << "Binding socket to network address"
<< " 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 {
webrtc::MutexLock lock(&mutex_);
return error_;
}
void PhysicalSocket::SetError(int error) {
webrtc::MutexLock lock(&mutex_);
error_ = error;
}
Socket::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) {
return -1;
}
if (opt == OPT_DONTFRAGMENT) {
#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
*value = (*value != IP_PMTUDISC_DONT) ? 1 : 0;
#endif
} else if (opt == OPT_DSCP) {
#if defined(WEBRTC_POSIX)
// unshift DSCP value to get six most significant bits of IP DiffServ field
*value >>= 2;
#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
} else if (opt == OPT_DSCP) {
#if defined(WEBRTC_POSIX)
// shift DSCP value to fit six most significant bits of IP DiffServ field
value <<= 2;
#endif
}
#if defined(WEBRTC_POSIX)
if (sopt == IPV6_TCLASS) {
// Set the IPv4 option in all cases to support dual-stack sockets.
// Don't bother checking the return code, as this is expected to fail if
// it's not actually dual-stack.
::setsockopt(s_, IPPROTO_IP, IP_TOS, (SockOptArg)&value, sizeof(value));
}
#endif
int result =
::setsockopt(s_, slevel, sopt, (SockOptArg)&value, sizeof(value));
if (result != 0) {
UpdateLastError();
}
return result;
}
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 =
DoReadFromSocket(buffer, length, /*out_addr*/ nullptr, timestamp);
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;
}
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) {
int received = DoReadFromSocket(buffer, length, out_addr, timestamp);
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::DoReadFromSocket(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);
#if defined(WEBRTC_POSIX)
int received = 0;
if (read_scm_timestamp_experiment_) {
iovec iov = {.iov_base = buffer, .iov_len = length};
msghdr msg = {.msg_iov = &iov, .msg_iovlen = 1};
if (out_addr) {
out_addr->Clear();
msg.msg_name = addr;
msg.msg_namelen = addr_len;
}
char control[CMSG_SPACE(sizeof(struct timeval))] = {};
if (timestamp) {
*timestamp = -1;
msg.msg_control = &control;
msg.msg_controllen = sizeof(control);
}
received = ::recvmsg(s_, &msg, 0);
if (received <= 0) {
// An error occured or shut down.
return received;
}
if (timestamp) {
struct cmsghdr* cmsg;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level != SOL_SOCKET)
continue;
if (cmsg->cmsg_type == SCM_TIMESTAMP) {
timeval* ts = reinterpret_cast<timeval*>(CMSG_DATA(cmsg));
*timestamp =
rtc::kNumMicrosecsPerSec * static_cast<int64_t>(ts->tv_sec) +
static_cast<int64_t>(ts->tv_usec);
break;
}
}
}
if (out_addr) {
SocketAddressFromSockAddrStorage(addr_storage, out_addr);
}
} else { // !read_scm_timestamp_experiment_
if (out_addr) {
received = ::recvfrom(s_, static_cast<char*>(buffer),
static_cast<int>(length), 0, addr, &addr_len);
SocketAddressFromSockAddrStorage(addr_storage, out_addr);
} else {
received =
::recv(s_, static_cast<char*>(buffer), static_cast<int>(length), 0);
}
if (timestamp) {
*timestamp = GetSocketRecvTimestamp(s_);
}
}
return received;
#else
int received = 0;
if (out_addr) {
received = ::recvfrom(s_, static_cast<char*>(buffer),
static_cast<int>(length), 0, addr, &addr_len);
SocketAddressFromSockAddrStorage(addr_storage, out_addr);
} else {
received =
::recv(s_, static_cast<char*>(buffer), static_cast<int>(length), 0);
}
if (timestamp) {
*timestamp = -1;
}
return received;
#endif
}
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;
}
Socket* 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:
#if defined(WEBRTC_POSIX)
if (family_ == AF_INET6) {
*slevel = IPPROTO_IPV6;
*sopt = IPV6_TCLASS;
} else {
*slevel = IPPROTO_IP;
*sopt = IP_TOS;
}
break;
#else
RTC_LOG(LS_WARNING) << "Socket::OPT_DSCP not supported.";
return -1;
#endif
case OPT_RTP_SENDTIME_EXTN_ID:
return -1; // No logging is necessary as this not a OS socket option.
default:
RTC_DCHECK_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);
if (IsScmTimeStampExperimentEnabled()) {
int value = 1;
// Attempt to get receive packet timestamp from the socket.
if (::setsockopt(s_, SOL_SOCKET, SO_TIMESTAMP, &value, sizeof(value)) !=
0) {
RTC_DLOG(LS_ERROR) << "::setsockopt failed. errno: " << LAST_SYSTEM_ERROR;
}
}
#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;
if (::setsockopt(s_, SOL_SOCKET, SO_NOSIGPIPE, &value, sizeof(value)) != 0) {
RTC_DLOG(LS_ERROR) << "::setsockopt failed. errno: " << LAST_SYSTEM_ERROR;
}
#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;
// Retry if the system call was interrupted.
do {
res = ::recv(s_, &ch, 1, MSG_PEEK);
} while (res < 0 && errno == EINTR);
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:
// This is dangerous: if we keep attempting to access a FD after close,
// it could be reopened by something else making us think it's still
// open. Note that this is only a DCHECK.
RTC_DCHECK_NOTREACHED();
return true;
// Returned during ungraceful peer shutdown.
case ECONNRESET:
return true;
case ECONNABORTED:
return true;
case EPIPE:
return true;
// The normal blocking error; don't log anything.
case EWOULDBLOCK:
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();
}
#if defined(WEBRTC_WIN)
void SocketDispatcher::OnEvent(uint32_t ff, int err) {
if ((ff & DE_CONNECT) != 0)
state_ = CS_CONNECTED;
// We set CS_CLOSED from CheckSignalClose.
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 ((ff & DE_CONNECT) != 0)
state_ = CS_CONNECTED;
if ((ff & DE_CLOSE) != 0)
state_ = CS_CLOSED;
#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)
inline 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
#if defined(WEBRTC_USE_EPOLL)
// If we're batching events, the socket can be closed and reopened
// during the batch. Set saved_enabled_events_ to 0 here so the new
// socket, if any, has the correct old events bitfield
if (saved_enabled_events_ != -1) {
saved_enabled_events_ = 0;
}
#endif
ss_->Remove(this);
return PhysicalSocket::Close();
}
#if defined(WEBRTC_POSIX)
// Sets the value of a boolean value to false when signaled.
class Signaler : public Dispatcher {
public:
Signaler(PhysicalSocketServer* ss, bool& flag_to_clear)
: ss_(ss),
afd_([] {
std::array<int, 2> afd = {-1, -1};
if (pipe(afd.data()) < 0) {
RTC_LOG(LS_ERROR) << "pipe failed";
}
return afd;
}()),
fSignaled_(false),
flag_to_clear_(flag_to_clear) {
ss_->Add(this);
}
~Signaler() override {
ss_->Remove(this);
close(afd_[0]);
close(afd_[1]);
}
virtual void Signal() {
webrtc::MutexLock lock(&mutex_);
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 OnEvent(uint32_t ff, int err) override {
// It is not possible to perfectly emulate an auto-resetting event with
// pipes. This simulates it by resetting before the event is handled.
webrtc::MutexLock lock(&mutex_);
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;
}
flag_to_clear_ = false;
}
int GetDescriptor() override { return afd_[0]; }
bool IsDescriptorClosed() override { return false; }
private:
PhysicalSocketServer* const ss_;
const std::array<int, 2> afd_;
bool fSignaled_ RTC_GUARDED_BY(mutex_);
webrtc::Mutex mutex_;
bool& flag_to_clear_;
};
#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;
}
// Sets the value of a boolean value to false when signaled.
class Signaler : public Dispatcher {
public:
Signaler(PhysicalSocketServer* ss, bool& flag_to_clear)
: ss_(ss), flag_to_clear_(flag_to_clear) {
hev_ = WSACreateEvent();
if (hev_) {
ss_->Add(this);
}
}
~Signaler() 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 OnEvent(uint32_t ff, int err) override {
WSAResetEvent(hev_);
flag_to_clear_ = false;
}
WSAEVENT GetWSAEvent() override { return hev_; }
SOCKET GetSocket() override { return INVALID_SOCKET; }
bool CheckSignalClose() override { return false; }
private:
PhysicalSocketServer* ss_;
WSAEVENT hev_;
bool& flag_to_clear_;
};
#endif // WEBRTC_WIN
PhysicalSocketServer::PhysicalSocketServer()
:
#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)),
#endif
#if defined(WEBRTC_WIN)
socket_ev_(WSACreateEvent()),
#endif
fWait_(false) {
#if defined(WEBRTC_USE_EPOLL)
if (epoll_fd_ == -1) {
// Not an error, will fall back to "select" below.
RTC_LOG_E(LS_WARNING, EN, errno) << "epoll_create";
// Note that -1 == INVALID_SOCKET, the alias used by later checks.
}
#endif
// The `fWait_` flag to be cleared by the Signaler.
signal_wakeup_ = new Signaler(this, fWait_);
}
PhysicalSocketServer::~PhysicalSocketServer() {
#if defined(WEBRTC_WIN)
WSACloseEvent(socket_ev_);
#endif
delete signal_wakeup_;
#if defined(WEBRTC_USE_EPOLL)
if (epoll_fd_ != INVALID_SOCKET) {
close(epoll_fd_);
}
#endif
RTC_DCHECK(dispatcher_by_key_.empty());
RTC_DCHECK(key_by_dispatcher_.empty());
}
void PhysicalSocketServer::WakeUp() {
signal_wakeup_->Signal();
}
Socket* PhysicalSocketServer::CreateSocket(int family, int type) {
SocketDispatcher* dispatcher = new SocketDispatcher(this);
if (dispatcher->Create(family, type)) {
return dispatcher;
} else {
delete dispatcher;
return nullptr;
}
}
Socket* 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 (key_by_dispatcher_.count(pdispatcher)) {
RTC_LOG(LS_WARNING)
<< "PhysicalSocketServer asked to add a duplicate dispatcher.";
return;
}
uint64_t key = next_dispatcher_key_++;
dispatcher_by_key_.emplace(key, pdispatcher);
key_by_dispatcher_.emplace(pdispatcher, key);
#if defined(WEBRTC_USE_EPOLL)
if (epoll_fd_ != INVALID_SOCKET) {
AddEpoll(pdispatcher, key);
}
#endif // WEBRTC_USE_EPOLL
}
void PhysicalSocketServer::Remove(Dispatcher* pdispatcher) {
CritScope cs(&crit_);
if (!key_by_dispatcher_.count(pdispatcher)) {
RTC_LOG(LS_WARNING)
<< "PhysicalSocketServer asked to remove a unknown "
"dispatcher, potentially from a duplicate call to Add.";
return;
}
uint64_t key = key_by_dispatcher_.at(pdispatcher);
key_by_dispatcher_.erase(pdispatcher);
dispatcher_by_key_.erase(key);
#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;
}
// Don't update dispatchers that haven't yet been added.
CritScope cs(&crit_);
if (!key_by_dispatcher_.count(pdispatcher)) {
return;
}
UpdateEpoll(pdispatcher, key_by_dispatcher_.at(pdispatcher));
#endif
}
int PhysicalSocketServer::ToCmsWait(webrtc::TimeDelta max_wait_duration) {
return max_wait_duration == Event::kForever
? kForeverMs
: max_wait_duration.RoundUpTo(webrtc::TimeDelta::Millis(1)).ms();
}
#if defined(WEBRTC_POSIX)
bool PhysicalSocketServer::Wait(webrtc::TimeDelta max_wait_duration,
bool process_io) {
// We don't support reentrant waiting.
RTC_DCHECK(!waiting_);
ScopedSetTrue s(&waiting_);
const int cmsWait = ToCmsWait(max_wait_duration);
#if defined(WEBRTC_USE_POLL)
return WaitPoll(cmsWait, process_io);
#else
#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 WaitPollOneDispatcher(cmsWait, signal_wakeup_);
} else if (epoll_fd_ != INVALID_SOCKET) {
return WaitEpoll(cmsWait);
}
#endif
return WaitSelect(cmsWait, process_io);
#endif
}
// `error_event` is true if we are responding to an event where we know an
// error has occurred, which is possible with the poll/epoll implementations
// but not the select implementation.
//
// `check_error` is true if there is the possibility of an error.
static void ProcessEvents(Dispatcher* dispatcher,
bool readable,
bool writable,
bool error_event,
bool check_error) {
RTC_DCHECK(!(error_event && !check_error));
int errcode = 0;
if (check_error) {
socklen_t len = sizeof(errcode);
int res = ::getsockopt(dispatcher->GetDescriptor(), SOL_SOCKET, SO_ERROR,
&errcode, &len);
if (res < 0) {
// If we are sure an error has occurred, or if getsockopt failed for a
// socket descriptor, make sure we set the error code to a nonzero value.
if (error_event || errno != ENOTSOCK) {
errcode = EBADF;
}
}
}
// Most often the socket is writable or readable or both, so make a single
// virtual call to get requested events
const uint32_t requested_events = dispatcher->GetRequestedEvents();
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 (errcode || dispatcher->IsDescriptorClosed()) {
ff |= DE_CLOSE;
} else if (requested_events & DE_ACCEPT) {
ff |= DE_ACCEPT;
} 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 (requested_events & DE_CONNECT) {
if (!errcode) {
ff |= DE_CONNECT;
}
} else {
ff |= DE_WRITE;
}
}
// Make sure we report any errors regardless of whether readable or writable.
if (errcode) {
ff |= DE_CLOSE;
}
// Tell the descriptor about the event.
if (ff != 0) {
dispatcher->OnEvent(ff, errcode);
}
}
#if defined(WEBRTC_USE_POLL) || defined(WEBRTC_USE_EPOLL)
static void ProcessPollEvents(Dispatcher* dispatcher, const pollfd& pfd) {
bool readable = (pfd.revents & (POLLIN | POLLPRI));
bool writable = (pfd.revents & POLLOUT);
bool error = (pfd.revents & (POLLRDHUP | POLLERR | POLLHUP));
ProcessEvents(dispatcher, readable, writable, error, error);
}
static pollfd DispatcherToPollfd(Dispatcher* dispatcher) {
pollfd fd{
.fd = dispatcher->GetDescriptor(),
.events = 0,
.revents = 0,
};
uint32_t ff = dispatcher->GetRequestedEvents();
if (ff & (DE_READ | DE_ACCEPT)) {
fd.events |= POLLIN;
}
if (ff & (DE_WRITE | DE_CONNECT)) {
fd.events |= POLLOUT;
}
return fd;
}
#endif // WEBRTC_USE_POLL || WEBRTC_USE_EPOLL
bool PhysicalSocketServer::WaitSelect(int cmsWait, bool process_io) {
// Calculate timing information
struct timeval* ptvWait = nullptr;
struct timeval tvWait;
int64_t stop_us;
if (cmsWait != kForeverMs) {
// 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;
}
fd_set fdsRead;
fd_set 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_) {
// Zero all fd_sets. Although select() zeros the descriptors not signaled,
// we may need to do this for dispatchers that were deleted while
// iterating.
FD_ZERO(&fdsRead);
FD_ZERO(&fdsWrite);
int fdmax = -1;
{
CritScope cr(&crit_);
current_dispatcher_keys_.clear();
for (auto const& kv : dispatcher_by_key_) {
uint64_t key = kv.first;
Dispatcher* pdispatcher = kv.second;
if (!process_io && (pdispatcher != signal_wakeup_))
continue;
current_dispatcher_keys_.push_back(key);
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_);
// Iterate only on the dispatchers whose file descriptors were passed into
// select; this avoids the ABA problem (a socket being destroyed and a new
// one created with the same file descriptor).
for (uint64_t key : current_dispatcher_keys_) {
if (!dispatcher_by_key_.count(key))
continue;
Dispatcher* pdispatcher = dispatcher_by_key_.at(key);
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, /*error_event=*/false,
readable || writable);
}
}
// 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)
void PhysicalSocketServer::AddEpoll(Dispatcher* pdispatcher, uint64_t key) {
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());
if (event.events == 0u) {
// Don't add at all if we don't have any requested events. Could indicate a
// closed socket.
return;
}
event.data.u64 = key;
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);
// Ignore ENOENT, which could occur if this descriptor wasn't added due to
// having no requested events.
if (err == -1 && errno != ENOENT) {
RTC_LOG_E(LS_ERROR, EN, errno) << "epoll_ctl EPOLL_CTL_DEL";
}
}
void PhysicalSocketServer::UpdateEpoll(Dispatcher* pdispatcher, uint64_t key) {
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.u64 = key;
// Remove if we don't have any requested events. Could indicate a closed
// socket.
if (event.events == 0u) {
epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, fd, &event);
} else {
int err = epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, fd, &event);
RTC_DCHECK(err == 0 || errno == ENOENT);
if (err == -1) {
// Could have been removed earlier due to no requested events.
if (errno == ENOENT) {
err = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, fd, &event);
if (err == -1) {
RTC_LOG_E(LS_ERROR, EN, errno) << "epoll_ctl EPOLL_CTL_ADD";
}
} else {
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 msWait = -1;
int64_t msStop = -1;
if (cmsWait != kForeverMs) {
msWait = cmsWait;
msStop = TimeAfter(cmsWait);
}
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_.data(), epoll_events_.size(),
static_cast<int>(msWait));
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];
uint64_t key = event.data.u64;
if (!dispatcher_by_key_.count(key)) {
// The dispatcher for this socket no longer exists.
continue;
}
Dispatcher* pdispatcher = dispatcher_by_key_.at(key);
bool readable = (event.events & (EPOLLIN | EPOLLPRI));
bool writable = (event.events & EPOLLOUT);
bool error = (event.events & (EPOLLRDHUP | EPOLLERR | EPOLLHUP));
ProcessEvents(pdispatcher, readable, writable, error, error);
}
}
if (cmsWait != kForeverMs) {
msWait = TimeDiff(msStop, TimeMillis());
if (msWait <= 0) {
// Return success on timeout.
return true;
}
}
}
return true;
}
bool PhysicalSocketServer::WaitPollOneDispatcher(int cmsWait,
Dispatcher* dispatcher) {
RTC_DCHECK(dispatcher);
int64_t msWait = -1;
int64_t msStop = -1;
if (cmsWait != kForeverMs) {
msWait = cmsWait;
msStop = TimeAfter(cmsWait);
}
fWait_ = true;
const int fd = dispatcher->GetDescriptor();
while (fWait_) {
auto fds = DispatcherToPollfd(dispatcher);
// 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>(msWait));
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);
ProcessPollEvents(dispatcher, fds);
}
if (cmsWait != kForeverMs) {
msWait = TimeDiff(msStop, TimeMillis());
if (msWait < 0) {
// Return success on timeout.
return true;
}
}
}
return true;
}
#elif defined(WEBRTC_USE_POLL)
bool PhysicalSocketServer::WaitPoll(int cmsWait, bool process_io) {
int64_t msWait = -1;
int64_t msStop = -1;
if (cmsWait != kForeverMs) {
msWait = cmsWait;
msStop = TimeAfter(cmsWait);
}
std::vector<pollfd> pollfds;
fWait_ = true;
while (fWait_) {
{
CritScope cr(&crit_);
current_dispatcher_keys_.clear();
pollfds.clear();
pollfds.reserve(dispatcher_by_key_.size());
for (auto const& kv : dispatcher_by_key_) {
uint64_t key = kv.first;
Dispatcher* pdispatcher = kv.second;
if (!process_io && (pdispatcher != signal_wakeup_))
continue;
current_dispatcher_keys_.push_back(key);
pollfds.push_back(DispatcherToPollfd(pdispatcher));
}
}
// Wait then call handlers as appropriate
// < 0 means error
// 0 means timeout
// > 0 means count of descriptors ready
int n = poll(pollfds.data(), pollfds.size(), static_cast<int>(msWait));
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
CritScope cr(&crit_);
// Iterate only on the dispatchers whose file descriptors were passed into
// poll; this avoids the ABA problem (a socket being destroyed and a new
// one created with the same file descriptor).
for (size_t i = 0; i < current_dispatcher_keys_.size(); ++i) {
uint64_t key = current_dispatcher_keys_[i];
if (!dispatcher_by_key_.count(key))
continue;
ProcessPollEvents(dispatcher_by_key_.at(key), pollfds[i]);
}
}
if (cmsWait != kForeverMs) {
msWait = TimeDiff(msStop, TimeMillis());
if (msWait < 0) {
// Return success on timeout.
return true;
}
}
}
return true;
}
#endif // WEBRTC_USE_EPOLL, WEBRTC_USE_POLL
#endif // WEBRTC_POSIX
#if defined(WEBRTC_WIN)
bool PhysicalSocketServer::Wait(webrtc::TimeDelta max_wait_duration,
bool process_io) {
// We don't support reentrant waiting.
RTC_DCHECK(!waiting_);
ScopedSetTrue s(&waiting_);
int cmsWait = ToCmsWait(max_wait_duration);
int64_t cmsTotal = cmsWait;
int64_t cmsElapsed = 0;
int64_t msStart = Time();
fWait_ = true;
while (fWait_) {
std::vector<WSAEVENT> events;
std::vector<uint64_t> event_owners;
events.push_back(socket_ev_);
{
CritScope cr(&crit_);
// Get a snapshot of all current dispatchers; this is used to avoid the
// ABA problem (see later comment) and avoids the dispatcher_by_key_
// iterator being invalidated by calling CheckSignalClose, which may
// remove the dispatcher from the list.
current_dispatcher_keys_.clear();
for (auto const& kv : dispatcher_by_key_) {
current_dispatcher_keys_.push_back(kv.first);
}
for (uint64_t key : current_dispatcher_keys_) {
if (!dispatcher_by_key_.count(key)) {
continue;
}
Dispatcher* disp = dispatcher_by_key_.at(key);
if (!disp)
continue;
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(key);
}
}
}
// Which is shorter, the delay wait or the asked wait?
int64_t cmsNext;
if (cmsWait == kForeverMs) {
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_DCHECK_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
uint64_t key = event_owners[index];
if (!dispatcher_by_key_.count(key)) {
// The dispatcher could have been removed while waiting for events.
continue;
}
Dispatcher* disp = dispatcher_by_key_.at(key);
disp->OnEvent(0, 0);
} else if (process_io) {
// Iterate only on the dispatchers whose sockets were passed into
// WSAEventSelect; this avoids the ABA problem (a socket being
// destroyed and a new one created with the same SOCKET handle).
for (uint64_t key : current_dispatcher_keys_) {
if (!dispatcher_by_key_.count(key)) {
continue;
}
Dispatcher* disp = dispatcher_by_key_.at(key);
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(LS_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(LS_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(LS_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(LS_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(LS_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->OnEvent(ff, errcode);
}
}
}
}
// Reset the network event until new activity occurs
WSAResetEvent(socket_ev_);
}
// Break?
if (!fWait_)
break;
cmsElapsed = TimeSince(msStart);
if ((cmsWait != kForeverMs) && (cmsElapsed >= cmsWait)) {
break;
}
}
// Done
return true;
}
#endif // WEBRTC_WIN
} // namespace rtc