vn-verdnaturachat/ios/Pods/Flipper-Folly/folly/io/async/AsyncSocket.cpp

2936 lines
92 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <folly/io/async/AsyncSocket.h>
#include <folly/ExceptionWrapper.h>
#include <folly/Format.h>
#include <folly/Portability.h>
#include <folly/SocketAddress.h>
#include <folly/String.h>
#include <folly/io/Cursor.h>
#include <folly/io/IOBuf.h>
#include <folly/io/IOBufQueue.h>
#include <folly/io/SocketOptionMap.h>
#include <folly/portability/Fcntl.h>
#include <folly/portability/Sockets.h>
#include <folly/portability/SysUio.h>
#include <folly/portability/Unistd.h>
#include <boost/preprocessor/control/if.hpp>
#include <sys/types.h>
#include <cerrno>
#include <climits>
#include <sstream>
#include <thread>
#if defined(__linux__)
#include <linux/sockios.h>
#include <sys/ioctl.h>
#endif
#if FOLLY_HAVE_VLA
#define FOLLY_HAVE_VLA_01 1
#else
#define FOLLY_HAVE_VLA_01 0
#endif
using std::string;
using std::unique_ptr;
namespace fsp = folly::portability::sockets;
namespace folly {
static constexpr bool msgErrQueueSupported =
#ifdef FOLLY_HAVE_MSG_ERRQUEUE
true;
#else
false;
#endif // FOLLY_HAVE_MSG_ERRQUEUE
const AsyncSocketException socketClosedLocallyEx(
AsyncSocketException::END_OF_FILE,
"socket closed locally");
const AsyncSocketException socketShutdownForWritesEx(
AsyncSocketException::END_OF_FILE,
"socket shutdown for writes");
// TODO: It might help performance to provide a version of BytesWriteRequest
// that users could derive from, so we can avoid the extra allocation for each
// call to write()/writev().
//
// We would need the version for external users where they provide the iovec
// storage space, and only our internal version would allocate it at the end of
// the WriteRequest.
/* The default WriteRequest implementation, used for write(), writev() and
* writeChain()
*
* A new BytesWriteRequest operation is allocated on the heap for all write
* operations that cannot be completed immediately.
*/
class AsyncSocket::BytesWriteRequest : public AsyncSocket::WriteRequest {
public:
static BytesWriteRequest* newRequest(
AsyncSocket* socket,
WriteCallback* callback,
const iovec* ops,
uint32_t opCount,
uint32_t partialWritten,
uint32_t bytesWritten,
unique_ptr<IOBuf>&& ioBuf,
WriteFlags flags) {
assert(opCount > 0);
// Since we put a variable size iovec array at the end
// of each BytesWriteRequest, we have to manually allocate the memory.
void* buf =
malloc(sizeof(BytesWriteRequest) + (opCount * sizeof(struct iovec)));
if (buf == nullptr) {
throw std::bad_alloc();
}
return new (buf) BytesWriteRequest(
socket,
callback,
ops,
opCount,
partialWritten,
bytesWritten,
std::move(ioBuf),
flags);
}
void destroy() override {
this->~BytesWriteRequest();
free(this);
}
WriteResult performWrite() override {
WriteFlags writeFlags = flags_;
if (getNext() != nullptr) {
writeFlags |= WriteFlags::CORK;
}
socket_->adjustZeroCopyFlags(writeFlags);
auto writeResult = socket_->performWrite(
getOps(), getOpCount(), writeFlags, &opsWritten_, &partialBytes_);
bytesWritten_ = writeResult.writeReturn > 0 ? writeResult.writeReturn : 0;
if (bytesWritten_) {
if (socket_->isZeroCopyRequest(writeFlags)) {
if (isComplete()) {
socket_->addZeroCopyBuf(std::move(ioBuf_));
} else {
socket_->addZeroCopyBuf(ioBuf_.get());
}
} else {
// this happens if at least one of the prev requests were sent
// with zero copy but not the last one
if (isComplete() && socket_->getZeroCopy() &&
socket_->containsZeroCopyBuf(ioBuf_.get())) {
socket_->setZeroCopyBuf(std::move(ioBuf_));
}
}
}
return writeResult;
}
bool isComplete() override {
return opsWritten_ == getOpCount();
}
void consume() override {
// Advance opIndex_ forward by opsWritten_
opIndex_ += opsWritten_;
assert(opIndex_ < opCount_);
if (!socket_->isZeroCopyRequest(flags_)) {
// If we've finished writing any IOBufs, release them
if (ioBuf_) {
for (uint32_t i = opsWritten_; i != 0; --i) {
assert(ioBuf_);
ioBuf_ = ioBuf_->pop();
}
}
}
// Move partialBytes_ forward into the current iovec buffer
struct iovec* currentOp = writeOps_ + opIndex_;
assert((partialBytes_ < currentOp->iov_len) || (currentOp->iov_len == 0));
currentOp->iov_base =
reinterpret_cast<uint8_t*>(currentOp->iov_base) + partialBytes_;
currentOp->iov_len -= partialBytes_;
// Increment the totalBytesWritten_ count by bytesWritten_;
assert(bytesWritten_ >= 0);
totalBytesWritten_ += uint32_t(bytesWritten_);
}
private:
BytesWriteRequest(
AsyncSocket* socket,
WriteCallback* callback,
const struct iovec* ops,
uint32_t opCount,
uint32_t partialBytes,
uint32_t bytesWritten,
unique_ptr<IOBuf>&& ioBuf,
WriteFlags flags)
: AsyncSocket::WriteRequest(socket, callback),
opCount_(opCount),
opIndex_(0),
flags_(flags),
ioBuf_(std::move(ioBuf)),
opsWritten_(0),
partialBytes_(partialBytes),
bytesWritten_(bytesWritten) {
memcpy(writeOps_, ops, sizeof(*ops) * opCount_);
}
// private destructor, to ensure callers use destroy()
~BytesWriteRequest() override = default;
const struct iovec* getOps() const {
assert(opCount_ > opIndex_);
return writeOps_ + opIndex_;
}
uint32_t getOpCount() const {
assert(opCount_ > opIndex_);
return opCount_ - opIndex_;
}
uint32_t opCount_; ///< number of entries in writeOps_
uint32_t opIndex_; ///< current index into writeOps_
WriteFlags flags_; ///< set for WriteFlags
unique_ptr<IOBuf> ioBuf_; ///< underlying IOBuf, or nullptr if N/A
// for consume(), how much we wrote on the last write
uint32_t opsWritten_; ///< complete ops written
uint32_t partialBytes_; ///< partial bytes of incomplete op written
ssize_t bytesWritten_; ///< bytes written altogether
struct iovec writeOps_[]; ///< write operation(s) list
};
int AsyncSocket::SendMsgParamsCallback::getDefaultFlags(
folly::WriteFlags flags,
bool zeroCopyEnabled) noexcept {
int msg_flags = MSG_DONTWAIT;
#ifdef MSG_NOSIGNAL // Linux-only
msg_flags |= MSG_NOSIGNAL;
#ifdef MSG_MORE
if (isSet(flags, WriteFlags::CORK)) {
// MSG_MORE tells the kernel we have more data to send, so wait for us to
// give it the rest of the data rather than immediately sending a partial
// frame, even when TCP_NODELAY is enabled.
msg_flags |= MSG_MORE;
}
#endif // MSG_MORE
#endif // MSG_NOSIGNAL
if (isSet(flags, WriteFlags::EOR)) {
// marks that this is the last byte of a record (response)
msg_flags |= MSG_EOR;
}
if (zeroCopyEnabled && isSet(flags, WriteFlags::WRITE_MSG_ZEROCOPY)) {
msg_flags |= MSG_ZEROCOPY;
}
return msg_flags;
}
namespace {
AsyncSocket::SendMsgParamsCallback defaultSendMsgParamsCallback;
// Based on flags, signal the transparent handler to disable certain functions
void disableTransparentFunctions(
NetworkSocket fd,
bool noTransparentTls,
bool noTSocks) {
(void)fd;
(void)noTransparentTls;
(void)noTSocks;
#if defined(__linux__)
if (noTransparentTls) {
// Ignore return value, errors are ok
VLOG(5) << "Disabling TTLS for fd " << fd;
netops::setsockopt(fd, SOL_SOCKET, SO_NO_TRANSPARENT_TLS, nullptr, 0);
}
if (noTSocks) {
VLOG(5) << "Disabling TSOCKS for fd " << fd;
// Ignore return value, errors are ok
netops::setsockopt(fd, SOL_SOCKET, SO_NO_TSOCKS, nullptr, 0);
}
#endif
}
} // namespace
AsyncSocket::AsyncSocket()
: eventBase_(nullptr),
writeTimeout_(this, nullptr),
ioHandler_(this, nullptr),
immediateReadHandler_(this) {
VLOG(5) << "new AsyncSocket()";
init();
}
AsyncSocket::AsyncSocket(EventBase* evb)
: eventBase_(evb),
writeTimeout_(this, evb),
ioHandler_(this, evb),
immediateReadHandler_(this) {
VLOG(5) << "new AsyncSocket(" << this << ", evb=" << evb << ")";
init();
}
AsyncSocket::AsyncSocket(
EventBase* evb,
const folly::SocketAddress& address,
uint32_t connectTimeout,
bool useZeroCopy)
: AsyncSocket(evb) {
setZeroCopy(useZeroCopy);
connect(nullptr, address, connectTimeout);
}
AsyncSocket::AsyncSocket(
EventBase* evb,
const std::string& ip,
uint16_t port,
uint32_t connectTimeout,
bool useZeroCopy)
: AsyncSocket(evb) {
setZeroCopy(useZeroCopy);
connect(nullptr, ip, port, connectTimeout);
}
AsyncSocket::AsyncSocket(
EventBase* evb,
NetworkSocket fd,
uint32_t zeroCopyBufId)
: zeroCopyBufId_(zeroCopyBufId),
eventBase_(evb),
writeTimeout_(this, evb),
ioHandler_(this, evb, fd),
immediateReadHandler_(this) {
VLOG(5) << "new AsyncSocket(" << this << ", evb=" << evb << ", fd=" << fd
<< ", zeroCopyBufId=" << zeroCopyBufId << ")";
init();
fd_ = fd;
disableTransparentFunctions(fd_, noTransparentTls_, noTSocks_);
setCloseOnExec();
state_ = StateEnum::ESTABLISHED;
}
AsyncSocket::AsyncSocket(AsyncSocket::UniquePtr oldAsyncSocket)
: AsyncSocket(
oldAsyncSocket->getEventBase(),
oldAsyncSocket->detachNetworkSocket(),
oldAsyncSocket->getZeroCopyBufId()) {
preReceivedData_ = std::move(oldAsyncSocket->preReceivedData_);
}
// init() method, since constructor forwarding isn't supported in most
// compilers yet.
void AsyncSocket::init() {
if (eventBase_) {
eventBase_->dcheckIsInEventBaseThread();
}
shutdownFlags_ = 0;
state_ = StateEnum::UNINIT;
eventFlags_ = EventHandler::NONE;
fd_ = NetworkSocket();
sendTimeout_ = 0;
maxReadsPerEvent_ = 16;
connectCallback_ = nullptr;
errMessageCallback_ = nullptr;
readCallback_ = nullptr;
writeReqHead_ = nullptr;
writeReqTail_ = nullptr;
wShutdownSocketSet_.reset();
appBytesWritten_ = 0;
appBytesReceived_ = 0;
totalAppBytesScheduledForWrite_ = 0;
sendMsgParamCallback_ = &defaultSendMsgParamsCallback;
}
AsyncSocket::~AsyncSocket() {
VLOG(7) << "actual destruction of AsyncSocket(this=" << this
<< ", evb=" << eventBase_ << ", fd=" << fd_ << ", state=" << state_
<< ")";
}
void AsyncSocket::destroy() {
VLOG(5) << "AsyncSocket::destroy(this=" << this << ", evb=" << eventBase_
<< ", fd=" << fd_ << ", state=" << state_;
// When destroy is called, close the socket immediately
closeNow();
// Then call DelayedDestruction::destroy() to take care of
// whether or not we need immediate or delayed destruction
DelayedDestruction::destroy();
}
NetworkSocket AsyncSocket::detachNetworkSocket() {
VLOG(6) << "AsyncSocket::detachFd(this=" << this << ", fd=" << fd_
<< ", evb=" << eventBase_ << ", state=" << state_
<< ", events=" << std::hex << eventFlags_ << ")";
// Extract the fd, and set fd_ to -1 first, so closeNow() won't
// actually close the descriptor.
if (const auto socketSet = wShutdownSocketSet_.lock()) {
socketSet->remove(fd_);
}
auto fd = fd_;
fd_ = NetworkSocket();
// Call closeNow() to invoke all pending callbacks with an error.
closeNow();
// Update the EventHandler to stop using this fd.
// This can only be done after closeNow() unregisters the handler.
ioHandler_.changeHandlerFD(NetworkSocket());
return fd;
}
const folly::SocketAddress& AsyncSocket::anyAddress() {
static const folly::SocketAddress anyAddress =
folly::SocketAddress("0.0.0.0", 0);
return anyAddress;
}
void AsyncSocket::setShutdownSocketSet(
const std::weak_ptr<ShutdownSocketSet>& wNewSS) {
const auto newSS = wNewSS.lock();
const auto shutdownSocketSet = wShutdownSocketSet_.lock();
if (newSS == shutdownSocketSet) {
return;
}
if (shutdownSocketSet && fd_ != NetworkSocket()) {
shutdownSocketSet->remove(fd_);
}
if (newSS && fd_ != NetworkSocket()) {
newSS->add(fd_);
}
wShutdownSocketSet_ = wNewSS;
}
void AsyncSocket::setCloseOnExec() {
int rv = netops::set_socket_close_on_exec(fd_);
if (rv != 0) {
auto errnoCopy = errno;
throw AsyncSocketException(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to set close-on-exec flag"),
errnoCopy);
}
}
void AsyncSocket::connect(
ConnectCallback* callback,
const folly::SocketAddress& address,
int timeout,
const SocketOptionMap& options,
const folly::SocketAddress& bindAddr) noexcept {
DestructorGuard dg(this);
eventBase_->dcheckIsInEventBaseThread();
addr_ = address;
// Make sure we're in the uninitialized state
if (state_ != StateEnum::UNINIT) {
return invalidState(callback);
}
connectTimeout_ = std::chrono::milliseconds(timeout);
connectStartTime_ = std::chrono::steady_clock::now();
// Make connect end time at least >= connectStartTime.
connectEndTime_ = connectStartTime_;
assert(fd_ == NetworkSocket());
state_ = StateEnum::CONNECTING;
connectCallback_ = callback;
sockaddr_storage addrStorage;
auto saddr = reinterpret_cast<sockaddr*>(&addrStorage);
try {
// Create the socket
// Technically the first parameter should actually be a protocol family
// constant (PF_xxx) rather than an address family (AF_xxx), but the
// distinction is mainly just historical. In pretty much all
// implementations the PF_foo and AF_foo constants are identical.
fd_ = netops::socket(address.getFamily(), SOCK_STREAM, 0);
if (fd_ == NetworkSocket()) {
auto errnoCopy = errno;
throw AsyncSocketException(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to create socket"),
errnoCopy);
}
disableTransparentFunctions(fd_, noTransparentTls_, noTSocks_);
if (const auto shutdownSocketSet = wShutdownSocketSet_.lock()) {
shutdownSocketSet->add(fd_);
}
ioHandler_.changeHandlerFD(fd_);
setCloseOnExec();
// Put the socket in non-blocking mode
int rv = netops::set_socket_non_blocking(fd_);
if (rv == -1) {
auto errnoCopy = errno;
throw AsyncSocketException(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to put socket in non-blocking mode"),
errnoCopy);
}
#if !defined(MSG_NOSIGNAL) && defined(F_SETNOSIGPIPE)
// iOS and OS X don't support MSG_NOSIGNAL; set F_SETNOSIGPIPE instead
rv = fcntl(fd_.toFd(), F_SETNOSIGPIPE, 1);
if (rv == -1) {
auto errnoCopy = errno;
throw AsyncSocketException(
AsyncSocketException::INTERNAL_ERROR,
"failed to enable F_SETNOSIGPIPE on socket",
errnoCopy);
}
#endif
// By default, turn on TCP_NODELAY
// If setNoDelay() fails, we continue anyway; this isn't a fatal error.
// setNoDelay() will log an error message if it fails.
// Also set the cached zeroCopyVal_ since it cannot be set earlier if the fd
// is not created
if (address.getFamily() != AF_UNIX) {
(void)setNoDelay(true);
setZeroCopy(zeroCopyVal_);
}
// Apply the additional PRE_BIND options if any.
applyOptions(options, SocketOptionKey::ApplyPos::PRE_BIND);
VLOG(5) << "AsyncSocket::connect(this=" << this << ", evb=" << eventBase_
<< ", fd=" << fd_ << ", host=" << address.describe().c_str();
// bind the socket
if (bindAddr != anyAddress()) {
int one = 1;
if (netops::setsockopt(
fd_, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one))) {
auto errnoCopy = errno;
doClose();
throw AsyncSocketException(
AsyncSocketException::NOT_OPEN,
"failed to setsockopt prior to bind on " + bindAddr.describe(),
errnoCopy);
}
bindAddr.getAddress(&addrStorage);
if (netops::bind(fd_, saddr, bindAddr.getActualSize()) != 0) {
auto errnoCopy = errno;
doClose();
throw AsyncSocketException(
AsyncSocketException::NOT_OPEN,
"failed to bind to async socket: " + bindAddr.describe(),
errnoCopy);
}
}
// Apply the additional POST_BIND options if any.
applyOptions(options, SocketOptionKey::ApplyPos::POST_BIND);
// Call preConnect hook if any.
if (connectCallback_) {
connectCallback_->preConnect(fd_);
}
// Perform the connect()
address.getAddress(&addrStorage);
if (tfoEnabled_) {
state_ = StateEnum::FAST_OPEN;
tfoAttempted_ = true;
} else {
if (socketConnect(saddr, addr_.getActualSize()) < 0) {
return;
}
}
// If we're still here the connect() succeeded immediately.
// Fall through to call the callback outside of this try...catch block
} catch (const AsyncSocketException& ex) {
return failConnect(__func__, ex);
} catch (const std::exception& ex) {
// shouldn't happen, but handle it just in case
VLOG(4) << "AsyncSocket::connect(this=" << this << ", fd=" << fd_
<< "): unexpected " << typeid(ex).name()
<< " exception: " << ex.what();
AsyncSocketException tex(
AsyncSocketException::INTERNAL_ERROR,
withAddr(string("unexpected exception: ") + ex.what()));
return failConnect(__func__, tex);
}
// The connection succeeded immediately
// The read callback may not have been set yet, and no writes may be pending
// yet, so we don't have to register for any events at the moment.
VLOG(8) << "AsyncSocket::connect succeeded immediately; this=" << this;
assert(errMessageCallback_ == nullptr);
assert(readCallback_ == nullptr);
assert(writeReqHead_ == nullptr);
if (state_ != StateEnum::FAST_OPEN) {
state_ = StateEnum::ESTABLISHED;
}
invokeConnectSuccess();
}
int AsyncSocket::socketConnect(const struct sockaddr* saddr, socklen_t len) {
int rv = netops::connect(fd_, saddr, len);
if (rv < 0) {
auto errnoCopy = errno;
if (errnoCopy == EINPROGRESS) {
scheduleConnectTimeout();
registerForConnectEvents();
} else {
throw AsyncSocketException(
AsyncSocketException::NOT_OPEN,
"connect failed (immediately)",
errnoCopy);
}
}
return rv;
}
void AsyncSocket::scheduleConnectTimeout() {
// Connection in progress.
auto timeout = connectTimeout_.count();
if (timeout > 0) {
// Start a timer in case the connection takes too long.
if (!writeTimeout_.scheduleTimeout(uint32_t(timeout))) {
throw AsyncSocketException(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to schedule AsyncSocket connect timeout"));
}
}
}
void AsyncSocket::registerForConnectEvents() {
// Register for write events, so we'll
// be notified when the connection finishes/fails.
// Note that we don't register for a persistent event here.
assert(eventFlags_ == EventHandler::NONE);
eventFlags_ = EventHandler::WRITE;
if (!ioHandler_.registerHandler(eventFlags_)) {
throw AsyncSocketException(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to register AsyncSocket connect handler"));
}
}
void AsyncSocket::connect(
ConnectCallback* callback,
const string& ip,
uint16_t port,
int timeout,
const SocketOptionMap& options) noexcept {
DestructorGuard dg(this);
try {
connectCallback_ = callback;
connect(callback, folly::SocketAddress(ip, port), timeout, options);
} catch (const std::exception& ex) {
AsyncSocketException tex(AsyncSocketException::INTERNAL_ERROR, ex.what());
return failConnect(__func__, tex);
}
}
void AsyncSocket::cancelConnect() {
connectCallback_ = nullptr;
if (state_ == StateEnum::CONNECTING || state_ == StateEnum::FAST_OPEN) {
closeNow();
}
}
void AsyncSocket::setSendTimeout(uint32_t milliseconds) {
sendTimeout_ = milliseconds;
if (eventBase_) {
eventBase_->dcheckIsInEventBaseThread();
}
// If we are currently pending on write requests, immediately update
// writeTimeout_ with the new value.
if ((eventFlags_ & EventHandler::WRITE) &&
(state_ != StateEnum::CONNECTING && state_ != StateEnum::FAST_OPEN)) {
assert(state_ == StateEnum::ESTABLISHED);
assert((shutdownFlags_ & SHUT_WRITE) == 0);
if (sendTimeout_ > 0) {
if (!writeTimeout_.scheduleTimeout(sendTimeout_)) {
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to reschedule send timeout in setSendTimeout"));
return failWrite(__func__, ex);
}
} else {
writeTimeout_.cancelTimeout();
}
}
}
void AsyncSocket::setErrMessageCB(ErrMessageCallback* callback) {
VLOG(6) << "AsyncSocket::setErrMessageCB() this=" << this << ", fd=" << fd_
<< ", callback=" << callback << ", state=" << state_;
// In the latest stable kernel 4.14.3 as of 2017-12-04, unix domain
// socket does not support MSG_ERRQUEUE. So recvmsg(MSG_ERRQUEUE)
// will read application data from unix doamin socket as error
// message, which breaks the message flow in application. Feel free
// to remove the next code block if MSG_ERRQUEUE is added for unix
// domain socket in the future.
if (callback != nullptr) {
cacheLocalAddress();
if (localAddr_.getFamily() == AF_UNIX) {
LOG(ERROR) << "Failed to set ErrMessageCallback=" << callback
<< " for Unix Doamin Socket where MSG_ERRQUEUE is unsupported,"
<< " fd=" << fd_;
return;
}
}
// Short circuit if callback is the same as the existing errMessageCallback_.
if (callback == errMessageCallback_) {
return;
}
if (!msgErrQueueSupported) {
// Per-socket error message queue is not supported on this platform.
return invalidState(callback);
}
DestructorGuard dg(this);
eventBase_->dcheckIsInEventBaseThread();
if (callback == nullptr) {
// We should be able to reset the callback regardless of the
// socket state. It's important to have a reliable callback
// cancellation mechanism.
errMessageCallback_ = callback;
return;
}
switch ((StateEnum)state_) {
case StateEnum::CONNECTING:
case StateEnum::FAST_OPEN:
case StateEnum::ESTABLISHED: {
errMessageCallback_ = callback;
return;
}
case StateEnum::CLOSED:
case StateEnum::ERROR:
// We should never reach here. SHUT_READ should always be set
// if we are in STATE_CLOSED or STATE_ERROR.
assert(false);
return invalidState(callback);
case StateEnum::UNINIT:
// We do not allow setReadCallback() to be called before we start
// connecting.
return invalidState(callback);
}
// We don't put a default case in the switch statement, so that the compiler
// will warn us to update the switch statement if a new state is added.
return invalidState(callback);
}
AsyncSocket::ErrMessageCallback* AsyncSocket::getErrMessageCallback() const {
return errMessageCallback_;
}
void AsyncSocket::setSendMsgParamCB(SendMsgParamsCallback* callback) {
sendMsgParamCallback_ = callback;
}
AsyncSocket::SendMsgParamsCallback* AsyncSocket::getSendMsgParamsCB() const {
return sendMsgParamCallback_;
}
void AsyncSocket::setReadCB(ReadCallback* callback) {
VLOG(6) << "AsyncSocket::setReadCallback() this=" << this << ", fd=" << fd_
<< ", callback=" << callback << ", state=" << state_;
// Short circuit if callback is the same as the existing readCallback_.
//
// Note that this is needed for proper functioning during some cleanup cases.
// During cleanup we allow setReadCallback(nullptr) to be called even if the
// read callback is already unset and we have been detached from an event
// base. This check prevents us from asserting
// eventBase_->isInEventBaseThread() when eventBase_ is nullptr.
if (callback == readCallback_) {
return;
}
/* We are removing a read callback */
if (callback == nullptr && immediateReadHandler_.isLoopCallbackScheduled()) {
immediateReadHandler_.cancelLoopCallback();
}
if (shutdownFlags_ & SHUT_READ) {
// Reads have already been shut down on this socket.
//
// Allow setReadCallback(nullptr) to be called in this case, but don't
// allow a new callback to be set.
//
// For example, setReadCallback(nullptr) can happen after an error if we
// invoke some other error callback before invoking readError(). The other
// error callback that is invoked first may go ahead and clear the read
// callback before we get a chance to invoke readError().
if (callback != nullptr) {
return invalidState(callback);
}
assert((eventFlags_ & EventHandler::READ) == 0);
readCallback_ = nullptr;
return;
}
DestructorGuard dg(this);
eventBase_->dcheckIsInEventBaseThread();
switch ((StateEnum)state_) {
case StateEnum::CONNECTING:
case StateEnum::FAST_OPEN:
// For convenience, we allow the read callback to be set while we are
// still connecting. We just store the callback for now. Once the
// connection completes we'll register for read events.
readCallback_ = callback;
return;
case StateEnum::ESTABLISHED: {
readCallback_ = callback;
uint16_t oldFlags = eventFlags_;
if (readCallback_) {
eventFlags_ |= EventHandler::READ;
} else {
eventFlags_ &= ~EventHandler::READ;
}
// Update our registration if our flags have changed
if (eventFlags_ != oldFlags) {
// We intentionally ignore the return value here.
// updateEventRegistration() will move us into the error state if it
// fails, and we don't need to do anything else here afterwards.
(void)updateEventRegistration();
}
if (readCallback_) {
checkForImmediateRead();
}
return;
}
case StateEnum::CLOSED:
case StateEnum::ERROR:
// We should never reach here. SHUT_READ should always be set
// if we are in STATE_CLOSED or STATE_ERROR.
assert(false);
return invalidState(callback);
case StateEnum::UNINIT:
// We do not allow setReadCallback() to be called before we start
// connecting.
return invalidState(callback);
}
// We don't put a default case in the switch statement, so that the compiler
// will warn us to update the switch statement if a new state is added.
return invalidState(callback);
}
AsyncSocket::ReadCallback* AsyncSocket::getReadCallback() const {
return readCallback_;
}
bool AsyncSocket::setZeroCopy(bool enable) {
if (msgErrQueueSupported) {
zeroCopyVal_ = enable;
if (fd_ == NetworkSocket()) {
return false;
}
int val = enable ? 1 : 0;
int ret =
netops::setsockopt(fd_, SOL_SOCKET, SO_ZEROCOPY, &val, sizeof(val));
// if enable == false, set zeroCopyEnabled_ = false regardless
// if SO_ZEROCOPY is set or not
if (!enable) {
zeroCopyEnabled_ = enable;
return true;
}
/* if the setsockopt failed, try to see if the socket inherited the flag
* since we cannot set SO_ZEROCOPY on a socket s = accept
*/
if (ret) {
val = 0;
socklen_t optlen = sizeof(val);
ret = netops::getsockopt(fd_, SOL_SOCKET, SO_ZEROCOPY, &val, &optlen);
if (!ret) {
enable = val != 0;
}
}
if (!ret) {
zeroCopyEnabled_ = enable;
return true;
}
}
return false;
}
void AsyncSocket::setZeroCopyEnableFunc(AsyncWriter::ZeroCopyEnableFunc func) {
zeroCopyEnableFunc_ = func;
}
void AsyncSocket::setZeroCopyReenableThreshold(size_t threshold) {
zeroCopyReenableThreshold_ = threshold;
}
bool AsyncSocket::isZeroCopyRequest(WriteFlags flags) {
return (zeroCopyEnabled_ && isSet(flags, WriteFlags::WRITE_MSG_ZEROCOPY));
}
void AsyncSocket::adjustZeroCopyFlags(folly::WriteFlags& flags) {
if (!zeroCopyEnabled_) {
// if the zeroCopyReenableCounter_ is > 0
// we try to dec and if we reach 0
// we set zeroCopyEnabled_ to true
if (zeroCopyReenableCounter_) {
if (0 == --zeroCopyReenableCounter_) {
zeroCopyEnabled_ = true;
return;
}
}
flags = unSet(flags, folly::WriteFlags::WRITE_MSG_ZEROCOPY);
}
}
void AsyncSocket::addZeroCopyBuf(std::unique_ptr<folly::IOBuf>&& buf) {
uint32_t id = getNextZeroCopyBufId();
folly::IOBuf* ptr = buf.get();
idZeroCopyBufPtrMap_[id] = ptr;
auto& p = idZeroCopyBufInfoMap_[ptr];
p.count_++;
CHECK(p.buf_.get() == nullptr);
p.buf_ = std::move(buf);
}
void AsyncSocket::addZeroCopyBuf(folly::IOBuf* ptr) {
uint32_t id = getNextZeroCopyBufId();
idZeroCopyBufPtrMap_[id] = ptr;
idZeroCopyBufInfoMap_[ptr].count_++;
}
void AsyncSocket::releaseZeroCopyBuf(uint32_t id) {
auto iter = idZeroCopyBufPtrMap_.find(id);
CHECK(iter != idZeroCopyBufPtrMap_.end());
auto ptr = iter->second;
auto iter1 = idZeroCopyBufInfoMap_.find(ptr);
CHECK(iter1 != idZeroCopyBufInfoMap_.end());
if (0 == --iter1->second.count_) {
idZeroCopyBufInfoMap_.erase(iter1);
}
idZeroCopyBufPtrMap_.erase(iter);
}
void AsyncSocket::setZeroCopyBuf(std::unique_ptr<folly::IOBuf>&& buf) {
folly::IOBuf* ptr = buf.get();
auto& p = idZeroCopyBufInfoMap_[ptr];
CHECK(p.buf_.get() == nullptr);
p.buf_ = std::move(buf);
}
bool AsyncSocket::containsZeroCopyBuf(folly::IOBuf* ptr) {
return (idZeroCopyBufInfoMap_.find(ptr) != idZeroCopyBufInfoMap_.end());
}
bool AsyncSocket::isZeroCopyMsg(const cmsghdr& cmsg) const {
#ifdef FOLLY_HAVE_MSG_ERRQUEUE
if ((cmsg.cmsg_level == SOL_IP && cmsg.cmsg_type == IP_RECVERR) ||
(cmsg.cmsg_level == SOL_IPV6 && cmsg.cmsg_type == IPV6_RECVERR)) {
auto serr =
reinterpret_cast<const struct sock_extended_err*>(CMSG_DATA(&cmsg));
return (
(serr->ee_errno == 0) && (serr->ee_origin == SO_EE_ORIGIN_ZEROCOPY));
}
#endif
(void)cmsg;
return false;
}
void AsyncSocket::processZeroCopyMsg(const cmsghdr& cmsg) {
#ifdef FOLLY_HAVE_MSG_ERRQUEUE
auto serr =
reinterpret_cast<const struct sock_extended_err*>(CMSG_DATA(&cmsg));
uint32_t hi = serr->ee_data;
uint32_t lo = serr->ee_info;
// disable zero copy if the buffer was actually copied
if ((serr->ee_code & SO_EE_CODE_ZEROCOPY_COPIED) && zeroCopyEnabled_) {
VLOG(2) << "AsyncSocket::processZeroCopyMsg(): setting "
<< "zeroCopyEnabled_ = false due to SO_EE_CODE_ZEROCOPY_COPIED "
<< "on " << fd_;
zeroCopyEnabled_ = false;
}
for (uint32_t i = lo; i <= hi; i++) {
releaseZeroCopyBuf(i);
}
#else
(void)cmsg;
#endif
}
void AsyncSocket::write(
WriteCallback* callback,
const void* buf,
size_t bytes,
WriteFlags flags) {
iovec op;
op.iov_base = const_cast<void*>(buf);
op.iov_len = bytes;
writeImpl(callback, &op, 1, unique_ptr<IOBuf>(), bytes, flags);
}
void AsyncSocket::writev(
WriteCallback* callback,
const iovec* vec,
size_t count,
WriteFlags flags) {
size_t totalBytes = 0;
for (size_t i = 0; i < count; ++i) {
totalBytes += vec[i].iov_len;
}
writeImpl(callback, vec, count, unique_ptr<IOBuf>(), totalBytes, flags);
}
void AsyncSocket::writeChain(
WriteCallback* callback,
unique_ptr<IOBuf>&& buf,
WriteFlags flags) {
adjustZeroCopyFlags(flags);
// adjustZeroCopyFlags can set zeroCopyEnabled_ to true
if (zeroCopyEnabled_ && !isSet(flags, WriteFlags::WRITE_MSG_ZEROCOPY) &&
zeroCopyEnableFunc_ && zeroCopyEnableFunc_(buf)) {
flags |= WriteFlags::WRITE_MSG_ZEROCOPY;
}
constexpr size_t kSmallSizeMax = 64;
size_t count = buf->countChainElements();
if (count <= kSmallSizeMax) {
// suppress "warning: variable length array 'vec' is used [-Wvla]"
FOLLY_PUSH_WARNING
FOLLY_GNU_DISABLE_WARNING("-Wvla")
iovec vec[BOOST_PP_IF(FOLLY_HAVE_VLA_01, count, kSmallSizeMax)];
FOLLY_POP_WARNING
writeChainImpl(callback, vec, count, std::move(buf), flags);
} else {
std::unique_ptr<iovec[]> vec(new iovec[count]);
writeChainImpl(callback, vec.get(), count, std::move(buf), flags);
}
}
void AsyncSocket::writeChainImpl(
WriteCallback* callback,
iovec* vec,
size_t count,
unique_ptr<IOBuf>&& buf,
WriteFlags flags) {
auto res = buf->fillIov(vec, count);
writeImpl(
callback, vec, res.numIovecs, std::move(buf), res.totalLength, flags);
}
void AsyncSocket::writeImpl(
WriteCallback* callback,
const iovec* vec,
size_t count,
unique_ptr<IOBuf>&& buf,
size_t totalBytes,
WriteFlags flags) {
VLOG(6) << "AsyncSocket::writev() this=" << this << ", fd=" << fd_
<< ", callback=" << callback << ", count=" << count
<< ", state=" << state_;
DestructorGuard dg(this);
unique_ptr<IOBuf> ioBuf(std::move(buf));
eventBase_->dcheckIsInEventBaseThread();
totalAppBytesScheduledForWrite_ += totalBytes;
if (shutdownFlags_ & (SHUT_WRITE | SHUT_WRITE_PENDING)) {
// No new writes may be performed after the write side of the socket has
// been shutdown.
//
// We could just call callback->writeError() here to fail just this write.
// However, fail hard and use invalidState() to fail all outstanding
// callbacks and move the socket into the error state. There's most likely
// a bug in the caller's code, so we abort everything rather than trying to
// proceed as best we can.
return invalidState(callback);
}
uint32_t countWritten = 0;
uint32_t partialWritten = 0;
ssize_t bytesWritten = 0;
bool mustRegister = false;
if ((state_ == StateEnum::ESTABLISHED || state_ == StateEnum::FAST_OPEN) &&
!connecting()) {
if (writeReqHead_ == nullptr) {
// If we are established and there are no other writes pending,
// we can attempt to perform the write immediately.
assert(writeReqTail_ == nullptr);
assert((eventFlags_ & EventHandler::WRITE) == 0);
auto writeResult = performWrite(
vec, uint32_t(count), flags, &countWritten, &partialWritten);
bytesWritten = writeResult.writeReturn;
if (bytesWritten < 0) {
auto errnoCopy = errno;
if (writeResult.exception) {
return failWrite(__func__, callback, 0, *writeResult.exception);
}
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("writev failed"),
errnoCopy);
return failWrite(__func__, callback, 0, ex);
} else if (countWritten == count) {
// done, add the whole buffer
if (countWritten && isZeroCopyRequest(flags)) {
addZeroCopyBuf(std::move(ioBuf));
}
// We successfully wrote everything.
// Invoke the callback and return.
if (callback) {
callback->writeSuccess();
}
return;
} else { // continue writing the next writeReq
// add just the ptr
if (bytesWritten && isZeroCopyRequest(flags)) {
addZeroCopyBuf(ioBuf.get());
}
}
if (!connecting()) {
// Writes might put the socket back into connecting state
// if TFO is enabled, and using TFO fails.
// This means that write timeouts would not be active, however
// connect timeouts would affect this stage.
mustRegister = true;
}
}
} else if (!connecting()) {
// Invalid state for writing
return invalidState(callback);
}
// Create a new WriteRequest to add to the queue
WriteRequest* req;
try {
req = BytesWriteRequest::newRequest(
this,
callback,
vec + countWritten,
uint32_t(count - countWritten),
partialWritten,
uint32_t(bytesWritten),
std::move(ioBuf),
flags);
} catch (const std::exception& ex) {
// we mainly expect to catch std::bad_alloc here
AsyncSocketException tex(
AsyncSocketException::INTERNAL_ERROR,
withAddr(string("failed to append new WriteRequest: ") + ex.what()));
return failWrite(__func__, callback, size_t(bytesWritten), tex);
}
req->consume();
if (writeReqTail_ == nullptr) {
assert(writeReqHead_ == nullptr);
writeReqHead_ = writeReqTail_ = req;
} else {
writeReqTail_->append(req);
writeReqTail_ = req;
}
if (bufferCallback_) {
bufferCallback_->onEgressBuffered();
}
// Register for write events if are established and not currently
// waiting on write events
if (mustRegister) {
assert(state_ == StateEnum::ESTABLISHED);
assert((eventFlags_ & EventHandler::WRITE) == 0);
if (!updateEventRegistration(EventHandler::WRITE, 0)) {
assert(state_ == StateEnum::ERROR);
return;
}
if (sendTimeout_ > 0) {
// Schedule a timeout to fire if the write takes too long.
if (!writeTimeout_.scheduleTimeout(sendTimeout_)) {
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to schedule send timeout"));
return failWrite(__func__, ex);
}
}
}
}
void AsyncSocket::writeRequest(WriteRequest* req) {
if (writeReqTail_ == nullptr) {
assert(writeReqHead_ == nullptr);
writeReqHead_ = writeReqTail_ = req;
req->start();
} else {
writeReqTail_->append(req);
writeReqTail_ = req;
}
}
void AsyncSocket::close() {
VLOG(5) << "AsyncSocket::close(): this=" << this << ", fd_=" << fd_
<< ", state=" << state_ << ", shutdownFlags=" << std::hex
<< (int)shutdownFlags_;
// close() is only different from closeNow() when there are pending writes
// that need to drain before we can close. In all other cases, just call
// closeNow().
//
// Note that writeReqHead_ can be non-nullptr even in STATE_CLOSED or
// STATE_ERROR if close() is invoked while a previous closeNow() or failure
// is still running. (e.g., If there are multiple pending writes, and we
// call writeError() on the first one, it may call close(). In this case we
// will already be in STATE_CLOSED or STATE_ERROR, but the remaining pending
// writes will still be in the queue.)
//
// We only need to drain pending writes if we are still in STATE_CONNECTING
// or STATE_ESTABLISHED
if ((writeReqHead_ == nullptr) ||
!(state_ == StateEnum::CONNECTING || state_ == StateEnum::ESTABLISHED)) {
closeNow();
return;
}
// Declare a DestructorGuard to ensure that the AsyncSocket cannot be
// destroyed until close() returns.
DestructorGuard dg(this);
eventBase_->dcheckIsInEventBaseThread();
// Since there are write requests pending, we have to set the
// SHUT_WRITE_PENDING flag, and wait to perform the real close until the
// connect finishes and we finish writing these requests.
//
// Set SHUT_READ to indicate that reads are shut down, and set the
// SHUT_WRITE_PENDING flag to mark that we want to shutdown once the
// pending writes complete.
shutdownFlags_ |= (SHUT_READ | SHUT_WRITE_PENDING);
// If a read callback is set, invoke readEOF() immediately to inform it that
// the socket has been closed and no more data can be read.
if (readCallback_) {
// Disable reads if they are enabled
if (!updateEventRegistration(0, EventHandler::READ)) {
// We're now in the error state; callbacks have been cleaned up
assert(state_ == StateEnum::ERROR);
assert(readCallback_ == nullptr);
} else {
ReadCallback* callback = readCallback_;
readCallback_ = nullptr;
callback->readEOF();
}
}
}
void AsyncSocket::closeNow() {
VLOG(5) << "AsyncSocket::closeNow(): this=" << this << ", fd_=" << fd_
<< ", state=" << state_ << ", shutdownFlags=" << std::hex
<< (int)shutdownFlags_;
DestructorGuard dg(this);
if (eventBase_) {
eventBase_->dcheckIsInEventBaseThread();
}
switch (state_) {
case StateEnum::ESTABLISHED:
case StateEnum::CONNECTING:
case StateEnum::FAST_OPEN: {
shutdownFlags_ |= (SHUT_READ | SHUT_WRITE);
state_ = StateEnum::CLOSED;
// If the write timeout was set, cancel it.
writeTimeout_.cancelTimeout();
// If we are registered for I/O events, unregister.
if (eventFlags_ != EventHandler::NONE) {
eventFlags_ = EventHandler::NONE;
if (!updateEventRegistration()) {
// We will have been moved into the error state.
assert(state_ == StateEnum::ERROR);
return;
}
}
if (immediateReadHandler_.isLoopCallbackScheduled()) {
immediateReadHandler_.cancelLoopCallback();
}
if (fd_ != NetworkSocket()) {
ioHandler_.changeHandlerFD(NetworkSocket());
doClose();
}
invokeConnectErr(socketClosedLocallyEx);
failAllWrites(socketClosedLocallyEx);
if (readCallback_) {
ReadCallback* callback = readCallback_;
readCallback_ = nullptr;
callback->readEOF();
}
return;
}
case StateEnum::CLOSED:
// Do nothing. It's possible that we are being called recursively
// from inside a callback that we invoked inside another call to close()
// that is still running.
return;
case StateEnum::ERROR:
// Do nothing. The error handling code has performed (or is performing)
// cleanup.
return;
case StateEnum::UNINIT:
assert(eventFlags_ == EventHandler::NONE);
assert(connectCallback_ == nullptr);
assert(readCallback_ == nullptr);
assert(writeReqHead_ == nullptr);
shutdownFlags_ |= (SHUT_READ | SHUT_WRITE);
state_ = StateEnum::CLOSED;
return;
}
LOG(DFATAL) << "AsyncSocket::closeNow() (this=" << this << ", fd=" << fd_
<< ") called in unknown state " << state_;
}
void AsyncSocket::closeWithReset() {
// Enable SO_LINGER, with the linger timeout set to 0.
// This will trigger a TCP reset when we close the socket.
if (fd_ != NetworkSocket()) {
struct linger optLinger = {1, 0};
if (setSockOpt(SOL_SOCKET, SO_LINGER, &optLinger) != 0) {
VLOG(2) << "AsyncSocket::closeWithReset(): error setting SO_LINGER "
<< "on " << fd_ << ": errno=" << errno;
}
}
// Then let closeNow() take care of the rest
closeNow();
}
void AsyncSocket::shutdownWrite() {
VLOG(5) << "AsyncSocket::shutdownWrite(): this=" << this << ", fd=" << fd_
<< ", state=" << state_ << ", shutdownFlags=" << std::hex
<< (int)shutdownFlags_;
// If there are no pending writes, shutdownWrite() is identical to
// shutdownWriteNow().
if (writeReqHead_ == nullptr) {
shutdownWriteNow();
return;
}
eventBase_->dcheckIsInEventBaseThread();
// There are pending writes. Set SHUT_WRITE_PENDING so that the actual
// shutdown will be performed once all writes complete.
shutdownFlags_ |= SHUT_WRITE_PENDING;
}
void AsyncSocket::shutdownWriteNow() {
VLOG(5) << "AsyncSocket::shutdownWriteNow(): this=" << this << ", fd=" << fd_
<< ", state=" << state_ << ", shutdownFlags=" << std::hex
<< (int)shutdownFlags_;
if (shutdownFlags_ & SHUT_WRITE) {
// Writes are already shutdown; nothing else to do.
return;
}
// If SHUT_READ is already set, just call closeNow() to completely
// close the socket. This can happen if close() was called with writes
// pending, and then shutdownWriteNow() is called before all pending writes
// complete.
if (shutdownFlags_ & SHUT_READ) {
closeNow();
return;
}
DestructorGuard dg(this);
if (eventBase_) {
eventBase_->dcheckIsInEventBaseThread();
}
switch (static_cast<StateEnum>(state_)) {
case StateEnum::ESTABLISHED: {
shutdownFlags_ |= SHUT_WRITE;
// If the write timeout was set, cancel it.
writeTimeout_.cancelTimeout();
// If we are registered for write events, unregister.
if (!updateEventRegistration(0, EventHandler::WRITE)) {
// We will have been moved into the error state.
assert(state_ == StateEnum::ERROR);
return;
}
// Shutdown writes on the file descriptor
netops::shutdown(fd_, SHUT_WR);
// Immediately fail all write requests
failAllWrites(socketShutdownForWritesEx);
return;
}
case StateEnum::CONNECTING: {
// Set the SHUT_WRITE_PENDING flag.
// When the connection completes, it will check this flag,
// shutdown the write half of the socket, and then set SHUT_WRITE.
shutdownFlags_ |= SHUT_WRITE_PENDING;
// Immediately fail all write requests
failAllWrites(socketShutdownForWritesEx);
return;
}
case StateEnum::UNINIT:
// Callers normally shouldn't call shutdownWriteNow() before the socket
// even starts connecting. Nonetheless, go ahead and set
// SHUT_WRITE_PENDING. Once the socket eventually connects it will
// immediately shut down the write side of the socket.
shutdownFlags_ |= SHUT_WRITE_PENDING;
return;
case StateEnum::FAST_OPEN:
// In fast open state we haven't call connected yet, and if we shutdown
// the writes, we will never try to call connect, so shut everything down
shutdownFlags_ |= SHUT_WRITE;
// Immediately fail all write requests
failAllWrites(socketShutdownForWritesEx);
return;
case StateEnum::CLOSED:
case StateEnum::ERROR:
// We should never get here. SHUT_WRITE should always be set
// in STATE_CLOSED and STATE_ERROR.
VLOG(4) << "AsyncSocket::shutdownWriteNow() (this=" << this
<< ", fd=" << fd_ << ") in unexpected state " << state_
<< " with SHUT_WRITE not set (" << std::hex << (int)shutdownFlags_
<< ")";
assert(false);
return;
}
LOG(DFATAL) << "AsyncSocket::shutdownWriteNow() (this=" << this
<< ", fd=" << fd_ << ") called in unknown state " << state_;
}
bool AsyncSocket::readable() const {
if (fd_ == NetworkSocket()) {
return false;
}
netops::PollDescriptor fds[1];
fds[0].fd = fd_;
fds[0].events = POLLIN;
fds[0].revents = 0;
int rc = netops::poll(fds, 1, 0);
return rc == 1;
}
bool AsyncSocket::writable() const {
if (fd_ == NetworkSocket()) {
return false;
}
netops::PollDescriptor fds[1];
fds[0].fd = fd_;
fds[0].events = POLLOUT;
fds[0].revents = 0;
int rc = netops::poll(fds, 1, 0);
return rc == 1;
}
bool AsyncSocket::isPending() const {
return ioHandler_.isPending();
}
bool AsyncSocket::hangup() const {
if (fd_ == NetworkSocket()) {
// sanity check, no one should ask for hangup if we are not connected.
assert(false);
return false;
}
#ifdef POLLRDHUP // Linux-only
netops::PollDescriptor fds[1];
fds[0].fd = fd_;
fds[0].events = POLLRDHUP | POLLHUP;
fds[0].revents = 0;
netops::poll(fds, 1, 0);
return (fds[0].revents & (POLLRDHUP | POLLHUP)) != 0;
#else
return false;
#endif
}
bool AsyncSocket::good() const {
return (
(state_ == StateEnum::CONNECTING || state_ == StateEnum::FAST_OPEN ||
state_ == StateEnum::ESTABLISHED) &&
(shutdownFlags_ == 0) && (eventBase_ != nullptr));
}
bool AsyncSocket::error() const {
return (state_ == StateEnum::ERROR);
}
void AsyncSocket::attachEventBase(EventBase* eventBase) {
VLOG(5) << "AsyncSocket::attachEventBase(this=" << this << ", fd=" << fd_
<< ", old evb=" << eventBase_ << ", new evb=" << eventBase
<< ", state=" << state_ << ", events=" << std::hex << eventFlags_
<< ")";
assert(eventBase_ == nullptr);
eventBase->dcheckIsInEventBaseThread();
eventBase_ = eventBase;
ioHandler_.attachEventBase(eventBase);
updateEventRegistration();
writeTimeout_.attachEventBase(eventBase);
if (evbChangeCb_) {
evbChangeCb_->evbAttached(this);
}
}
void AsyncSocket::detachEventBase() {
VLOG(5) << "AsyncSocket::detachEventBase(this=" << this << ", fd=" << fd_
<< ", old evb=" << eventBase_ << ", state=" << state_
<< ", events=" << std::hex << eventFlags_ << ")";
assert(eventBase_ != nullptr);
eventBase_->dcheckIsInEventBaseThread();
eventBase_ = nullptr;
ioHandler_.unregisterHandler();
ioHandler_.detachEventBase();
writeTimeout_.detachEventBase();
if (evbChangeCb_) {
evbChangeCb_->evbDetached(this);
}
}
bool AsyncSocket::isDetachable() const {
DCHECK(eventBase_ != nullptr);
eventBase_->dcheckIsInEventBaseThread();
return !writeTimeout_.isScheduled();
}
void AsyncSocket::cacheAddresses() {
if (fd_ != NetworkSocket()) {
try {
cacheLocalAddress();
cachePeerAddress();
} catch (const std::system_error& e) {
if (e.code() != std::error_code(ENOTCONN, std::system_category())) {
VLOG(2) << "Error caching addresses: " << e.code().value() << ", "
<< e.code().message();
}
}
}
}
void AsyncSocket::cacheLocalAddress() const {
if (!localAddr_.isInitialized()) {
localAddr_.setFromLocalAddress(fd_);
}
}
void AsyncSocket::cachePeerAddress() const {
if (!addr_.isInitialized()) {
addr_.setFromPeerAddress(fd_);
}
}
void AsyncSocket::applyOptions(
const SocketOptionMap& options,
SocketOptionKey::ApplyPos pos) {
auto result = applySocketOptions(fd_, options, pos);
if (result != 0) {
throw AsyncSocketException(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to set socket option"),
result);
}
}
bool AsyncSocket::isZeroCopyWriteInProgress() const noexcept {
eventBase_->dcheckIsInEventBaseThread();
return (!idZeroCopyBufPtrMap_.empty());
}
void AsyncSocket::getLocalAddress(folly::SocketAddress* address) const {
cacheLocalAddress();
*address = localAddr_;
}
void AsyncSocket::getPeerAddress(folly::SocketAddress* address) const {
cachePeerAddress();
*address = addr_;
}
bool AsyncSocket::getTFOSucceded() const {
return detail::tfo_succeeded(fd_);
}
int AsyncSocket::setNoDelay(bool noDelay) {
if (fd_ == NetworkSocket()) {
VLOG(4) << "AsyncSocket::setNoDelay() called on non-open socket " << this
<< "(state=" << state_ << ")";
return EINVAL;
}
int value = noDelay ? 1 : 0;
if (netops::setsockopt(
fd_, IPPROTO_TCP, TCP_NODELAY, &value, sizeof(value)) != 0) {
int errnoCopy = errno;
VLOG(2) << "failed to update TCP_NODELAY option on AsyncSocket " << this
<< " (fd=" << fd_ << ", state=" << state_
<< "): " << errnoStr(errnoCopy);
return errnoCopy;
}
return 0;
}
int AsyncSocket::setCongestionFlavor(const std::string& cname) {
#ifndef TCP_CONGESTION
#define TCP_CONGESTION 13
#endif
if (fd_ == NetworkSocket()) {
VLOG(4) << "AsyncSocket::setCongestionFlavor() called on non-open "
<< "socket " << this << "(state=" << state_ << ")";
return EINVAL;
}
if (netops::setsockopt(
fd_,
IPPROTO_TCP,
TCP_CONGESTION,
cname.c_str(),
socklen_t(cname.length() + 1)) != 0) {
int errnoCopy = errno;
VLOG(2) << "failed to update TCP_CONGESTION option on AsyncSocket " << this
<< "(fd=" << fd_ << ", state=" << state_
<< "): " << errnoStr(errnoCopy);
return errnoCopy;
}
return 0;
}
int AsyncSocket::setQuickAck(bool quickack) {
(void)quickack;
if (fd_ == NetworkSocket()) {
VLOG(4) << "AsyncSocket::setQuickAck() called on non-open socket " << this
<< "(state=" << state_ << ")";
return EINVAL;
}
#ifdef TCP_QUICKACK // Linux-only
int value = quickack ? 1 : 0;
if (netops::setsockopt(
fd_, IPPROTO_TCP, TCP_QUICKACK, &value, sizeof(value)) != 0) {
int errnoCopy = errno;
VLOG(2) << "failed to update TCP_QUICKACK option on AsyncSocket" << this
<< "(fd=" << fd_ << ", state=" << state_
<< "): " << errnoStr(errnoCopy);
return errnoCopy;
}
return 0;
#else
return ENOSYS;
#endif
}
int AsyncSocket::setSendBufSize(size_t bufsize) {
if (fd_ == NetworkSocket()) {
VLOG(4) << "AsyncSocket::setSendBufSize() called on non-open socket "
<< this << "(state=" << state_ << ")";
return EINVAL;
}
if (netops::setsockopt(
fd_, SOL_SOCKET, SO_SNDBUF, &bufsize, sizeof(bufsize)) != 0) {
int errnoCopy = errno;
VLOG(2) << "failed to update SO_SNDBUF option on AsyncSocket" << this
<< "(fd=" << fd_ << ", state=" << state_
<< "): " << errnoStr(errnoCopy);
return errnoCopy;
}
return 0;
}
int AsyncSocket::setRecvBufSize(size_t bufsize) {
if (fd_ == NetworkSocket()) {
VLOG(4) << "AsyncSocket::setRecvBufSize() called on non-open socket "
<< this << "(state=" << state_ << ")";
return EINVAL;
}
if (netops::setsockopt(
fd_, SOL_SOCKET, SO_RCVBUF, &bufsize, sizeof(bufsize)) != 0) {
int errnoCopy = errno;
VLOG(2) << "failed to update SO_RCVBUF option on AsyncSocket" << this
<< "(fd=" << fd_ << ", state=" << state_
<< "): " << errnoStr(errnoCopy);
return errnoCopy;
}
return 0;
}
#if defined(__linux__)
size_t AsyncSocket::getSendBufInUse() const {
if (fd_ == NetworkSocket()) {
std::stringstream issueString;
issueString << "AsyncSocket::getSendBufInUse() called on non-open socket "
<< this << "(state=" << state_ << ")";
VLOG(4) << issueString.str();
throw std::logic_error(issueString.str());
}
size_t returnValue = 0;
if (-1 == ::ioctl(fd_.toFd(), SIOCOUTQ, &returnValue)) {
int errnoCopy = errno;
std::stringstream issueString;
issueString << "Failed to get the tx used bytes on Socket: " << this
<< "(fd=" << fd_ << ", state=" << state_
<< "): " << errnoStr(errnoCopy);
VLOG(2) << issueString.str();
throw std::logic_error(issueString.str());
}
return returnValue;
}
size_t AsyncSocket::getRecvBufInUse() const {
if (fd_ == NetworkSocket()) {
std::stringstream issueString;
issueString << "AsyncSocket::getRecvBufInUse() called on non-open socket "
<< this << "(state=" << state_ << ")";
VLOG(4) << issueString.str();
throw std::logic_error(issueString.str());
}
size_t returnValue = 0;
if (-1 == ::ioctl(fd_.toFd(), SIOCINQ, &returnValue)) {
std::stringstream issueString;
int errnoCopy = errno;
issueString << "Failed to get the rx used bytes on Socket: " << this
<< "(fd=" << fd_ << ", state=" << state_
<< "): " << errnoStr(errnoCopy);
VLOG(2) << issueString.str();
throw std::logic_error(issueString.str());
}
return returnValue;
}
#endif
int AsyncSocket::setTCPProfile(int profd) {
if (fd_ == NetworkSocket()) {
VLOG(4) << "AsyncSocket::setTCPProfile() called on non-open socket " << this
<< "(state=" << state_ << ")";
return EINVAL;
}
if (netops::setsockopt(
fd_, SOL_SOCKET, SO_SET_NAMESPACE, &profd, sizeof(int)) != 0) {
int errnoCopy = errno;
VLOG(2) << "failed to set socket namespace option on AsyncSocket" << this
<< "(fd=" << fd_ << ", state=" << state_
<< "): " << errnoStr(errnoCopy);
return errnoCopy;
}
return 0;
}
void AsyncSocket::ioReady(uint16_t events) noexcept {
VLOG(7) << "AsyncSocket::ioRead() this=" << this << ", fd=" << fd_
<< ", events=" << std::hex << events << ", state=" << state_;
DestructorGuard dg(this);
assert(events & EventHandler::READ_WRITE);
eventBase_->dcheckIsInEventBaseThread();
auto relevantEvents = uint16_t(events & EventHandler::READ_WRITE);
EventBase* originalEventBase = eventBase_;
// If we got there it means that either EventHandler::READ or
// EventHandler::WRITE is set. Any of these flags can
// indicate that there are messages available in the socket
// error message queue.
// Return if we handle any error messages - this is to avoid
// unnecessary read/write calls
if (handleErrMessages()) {
return;
}
// Return now if handleErrMessages() detached us from our EventBase
if (eventBase_ != originalEventBase) {
return;
}
if (relevantEvents == EventHandler::READ) {
handleRead();
} else if (relevantEvents == EventHandler::WRITE) {
handleWrite();
} else if (relevantEvents == EventHandler::READ_WRITE) {
// If both read and write events are ready, process writes first.
handleWrite();
// Return now if handleWrite() detached us from our EventBase
if (eventBase_ != originalEventBase) {
return;
}
// Only call handleRead() if a read callback is still installed.
// (It's possible that the read callback was uninstalled during
// handleWrite().)
if (readCallback_) {
handleRead();
}
} else {
VLOG(4) << "AsyncSocket::ioRead() called with unexpected events "
<< std::hex << events << "(this=" << this << ")";
abort();
}
}
AsyncSocket::ReadResult
AsyncSocket::performRead(void** buf, size_t* buflen, size_t* /* offset */) {
VLOG(5) << "AsyncSocket::performRead() this=" << this << ", buf=" << *buf
<< ", buflen=" << *buflen;
if (preReceivedData_ && !preReceivedData_->empty()) {
VLOG(5) << "AsyncSocket::performRead() this=" << this
<< ", reading pre-received data";
io::Cursor cursor(preReceivedData_.get());
auto len = cursor.pullAtMost(*buf, *buflen);
IOBufQueue queue;
queue.append(std::move(preReceivedData_));
queue.trimStart(len);
preReceivedData_ = queue.move();
appBytesReceived_ += len;
return ReadResult(len);
}
ssize_t bytes = netops::recv(fd_, *buf, *buflen, MSG_DONTWAIT);
if (bytes < 0) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
// No more data to read right now.
return ReadResult(READ_BLOCKING);
} else {
return ReadResult(READ_ERROR);
}
} else {
appBytesReceived_ += bytes;
return ReadResult(bytes);
}
}
void AsyncSocket::prepareReadBuffer(void** buf, size_t* buflen) {
// no matter what, buffer should be preapared for non-ssl socket
CHECK(readCallback_);
readCallback_->getReadBuffer(buf, buflen);
}
size_t AsyncSocket::handleErrMessages() noexcept {
// This method has non-empty implementation only for platforms
// supporting per-socket error queues.
VLOG(5) << "AsyncSocket::handleErrMessages() this=" << this << ", fd=" << fd_
<< ", state=" << state_;
if (errMessageCallback_ == nullptr && idZeroCopyBufPtrMap_.empty()) {
VLOG(7) << "AsyncSocket::handleErrMessages(): "
<< "no callback installed - exiting.";
return 0;
}
#ifdef FOLLY_HAVE_MSG_ERRQUEUE
uint8_t ctrl[1024];
unsigned char data;
struct msghdr msg;
iovec entry;
entry.iov_base = &data;
entry.iov_len = sizeof(data);
msg.msg_iov = &entry;
msg.msg_iovlen = 1;
msg.msg_name = nullptr;
msg.msg_namelen = 0;
msg.msg_control = ctrl;
msg.msg_controllen = sizeof(ctrl);
msg.msg_flags = 0;
int ret;
size_t num = 0;
// the socket may be closed by errMessage callback, so check on each iteration
while (fd_ != NetworkSocket()) {
ret = netops::recvmsg(fd_, &msg, MSG_ERRQUEUE);
VLOG(5) << "AsyncSocket::handleErrMessages(): recvmsg returned " << ret;
if (ret < 0) {
if (errno != EAGAIN) {
auto errnoCopy = errno;
LOG(ERROR) << "::recvmsg exited with code " << ret
<< ", errno: " << errnoCopy << ", fd: " << fd_;
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("recvmsg() failed"),
errnoCopy);
failErrMessageRead(__func__, ex);
}
return num;
}
for (struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg);
cmsg != nullptr && cmsg->cmsg_len != 0;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
++num;
if (isZeroCopyMsg(*cmsg)) {
processZeroCopyMsg(*cmsg);
} else {
if (errMessageCallback_) {
errMessageCallback_->errMessage(*cmsg);
}
}
}
}
return num;
#else
return 0;
#endif // FOLLY_HAVE_MSG_ERRQUEUE
}
bool AsyncSocket::processZeroCopyWriteInProgress() noexcept {
eventBase_->dcheckIsInEventBaseThread();
if (idZeroCopyBufPtrMap_.empty()) {
return true;
}
handleErrMessages();
return idZeroCopyBufPtrMap_.empty();
}
void AsyncSocket::handleRead() noexcept {
VLOG(5) << "AsyncSocket::handleRead() this=" << this << ", fd=" << fd_
<< ", state=" << state_;
assert(state_ == StateEnum::ESTABLISHED);
assert((shutdownFlags_ & SHUT_READ) == 0);
assert(readCallback_ != nullptr);
assert(eventFlags_ & EventHandler::READ);
// Loop until:
// - a read attempt would block
// - readCallback_ is uninstalled
// - the number of loop iterations exceeds the optional maximum
// - this AsyncSocket is moved to another EventBase
//
// When we invoke readDataAvailable() it may uninstall the readCallback_,
// which is why need to check for it here.
//
// The last bullet point is slightly subtle. readDataAvailable() may also
// detach this socket from this EventBase. However, before
// readDataAvailable() returns another thread may pick it up, attach it to
// a different EventBase, and install another readCallback_. We need to
// exit immediately after readDataAvailable() returns if the eventBase_ has
// changed. (The caller must perform some sort of locking to transfer the
// AsyncSocket between threads properly. This will be sufficient to ensure
// that this thread sees the updated eventBase_ variable after
// readDataAvailable() returns.)
uint16_t numReads = 0;
EventBase* originalEventBase = eventBase_;
while (readCallback_ && eventBase_ == originalEventBase) {
// Get the buffer to read into.
void* buf = nullptr;
size_t buflen = 0, offset = 0;
try {
prepareReadBuffer(&buf, &buflen);
VLOG(5) << "prepareReadBuffer() buf=" << buf << ", buflen=" << buflen;
} catch (const AsyncSocketException& ex) {
return failRead(__func__, ex);
} catch (const std::exception& ex) {
AsyncSocketException tex(
AsyncSocketException::BAD_ARGS,
string("ReadCallback::getReadBuffer() "
"threw exception: ") +
ex.what());
return failRead(__func__, tex);
} catch (...) {
AsyncSocketException ex(
AsyncSocketException::BAD_ARGS,
"ReadCallback::getReadBuffer() threw "
"non-exception type");
return failRead(__func__, ex);
}
if (buf == nullptr || buflen == 0) {
AsyncSocketException ex(
AsyncSocketException::BAD_ARGS,
"ReadCallback::getReadBuffer() returned "
"empty buffer");
return failRead(__func__, ex);
}
// Perform the read
auto readResult = performRead(&buf, &buflen, &offset);
auto bytesRead = readResult.readReturn;
VLOG(4) << "this=" << this << ", AsyncSocket::handleRead() got "
<< bytesRead << " bytes";
if (bytesRead > 0) {
readCallback_->readDataAvailable(size_t(bytesRead));
// Fall through and continue around the loop if the read
// completely filled the available buffer.
// Note that readCallback_ may have been uninstalled or changed inside
// readDataAvailable().
if (size_t(bytesRead) < buflen) {
return;
}
} else if (bytesRead == READ_BLOCKING) {
// No more data to read right now.
return;
} else if (bytesRead == READ_ERROR) {
readErr_ = READ_ERROR;
if (readResult.exception) {
return failRead(__func__, *readResult.exception);
}
auto errnoCopy = errno;
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("recv() failed"),
errnoCopy);
return failRead(__func__, ex);
} else {
assert(bytesRead == READ_EOF);
readErr_ = READ_EOF;
// EOF
shutdownFlags_ |= SHUT_READ;
if (!updateEventRegistration(0, EventHandler::READ)) {
// we've already been moved into STATE_ERROR
assert(state_ == StateEnum::ERROR);
assert(readCallback_ == nullptr);
return;
}
ReadCallback* callback = readCallback_;
readCallback_ = nullptr;
callback->readEOF();
return;
}
if (maxReadsPerEvent_ && (++numReads >= maxReadsPerEvent_)) {
if (readCallback_ != nullptr) {
// We might still have data in the socket.
// (e.g. see comment in AsyncSSLSocket::checkForImmediateRead)
scheduleImmediateRead();
}
return;
}
}
}
/**
* This function attempts to write as much data as possible, until no more data
* can be written.
*
* - If it sends all available data, it unregisters for write events, and stops
* the writeTimeout_.
*
* - If not all of the data can be sent immediately, it reschedules
* writeTimeout_ (if a non-zero timeout is set), and ensures the handler is
* registered for write events.
*/
void AsyncSocket::handleWrite() noexcept {
VLOG(5) << "AsyncSocket::handleWrite() this=" << this << ", fd=" << fd_
<< ", state=" << state_;
DestructorGuard dg(this);
if (state_ == StateEnum::CONNECTING) {
handleConnect();
return;
}
// Normal write
assert(state_ == StateEnum::ESTABLISHED);
assert((shutdownFlags_ & SHUT_WRITE) == 0);
assert(writeReqHead_ != nullptr);
// Loop until we run out of write requests,
// or until this socket is moved to another EventBase.
// (See the comment in handleRead() explaining how this can happen.)
EventBase* originalEventBase = eventBase_;
while (writeReqHead_ != nullptr && eventBase_ == originalEventBase) {
auto writeResult = writeReqHead_->performWrite();
if (writeResult.writeReturn < 0) {
if (writeResult.exception) {
return failWrite(__func__, *writeResult.exception);
}
auto errnoCopy = errno;
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("writev() failed"),
errnoCopy);
return failWrite(__func__, ex);
} else if (writeReqHead_->isComplete()) {
// We finished this request
WriteRequest* req = writeReqHead_;
writeReqHead_ = req->getNext();
if (writeReqHead_ == nullptr) {
writeReqTail_ = nullptr;
// This is the last write request.
// Unregister for write events and cancel the send timer
// before we invoke the callback. We have to update the state properly
// before calling the callback, since it may want to detach us from
// the EventBase.
if (eventFlags_ & EventHandler::WRITE) {
if (!updateEventRegistration(0, EventHandler::WRITE)) {
assert(state_ == StateEnum::ERROR);
return;
}
// Stop the send timeout
writeTimeout_.cancelTimeout();
}
assert(!writeTimeout_.isScheduled());
// If SHUT_WRITE_PENDING is set, we should shutdown the socket after
// we finish sending the last write request.
//
// We have to do this before invoking writeSuccess(), since
// writeSuccess() may detach us from our EventBase.
if (shutdownFlags_ & SHUT_WRITE_PENDING) {
assert(connectCallback_ == nullptr);
shutdownFlags_ |= SHUT_WRITE;
if (shutdownFlags_ & SHUT_READ) {
// Reads have already been shutdown. Fully close the socket and
// move to STATE_CLOSED.
//
// Note: This code currently moves us to STATE_CLOSED even if
// close() hasn't ever been called. This can occur if we have
// received EOF from the peer and shutdownWrite() has been called
// locally. Should we bother staying in STATE_ESTABLISHED in this
// case, until close() is actually called? I can't think of a
// reason why we would need to do so. No other operations besides
// calling close() or destroying the socket can be performed at
// this point.
assert(readCallback_ == nullptr);
state_ = StateEnum::CLOSED;
if (fd_ != NetworkSocket()) {
ioHandler_.changeHandlerFD(NetworkSocket());
doClose();
}
} else {
// Reads are still enabled, so we are only doing a half-shutdown
netops::shutdown(fd_, SHUT_WR);
}
}
}
// Invoke the callback
WriteCallback* callback = req->getCallback();
req->destroy();
if (callback) {
callback->writeSuccess();
}
// We'll continue around the loop, trying to write another request
} else {
// Partial write.
writeReqHead_->consume();
if (bufferCallback_) {
bufferCallback_->onEgressBuffered();
}
// Stop after a partial write; it's highly likely that a subsequent write
// attempt will just return EAGAIN.
//
// Ensure that we are registered for write events.
if ((eventFlags_ & EventHandler::WRITE) == 0) {
if (!updateEventRegistration(EventHandler::WRITE, 0)) {
assert(state_ == StateEnum::ERROR);
return;
}
}
// Reschedule the send timeout, since we have made some write progress.
if (sendTimeout_ > 0) {
if (!writeTimeout_.scheduleTimeout(sendTimeout_)) {
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to reschedule write timeout"));
return failWrite(__func__, ex);
}
}
return;
}
}
if (!writeReqHead_ && bufferCallback_) {
bufferCallback_->onEgressBufferCleared();
}
}
void AsyncSocket::checkForImmediateRead() noexcept {
// We currently don't attempt to perform optimistic reads in AsyncSocket.
// (However, note that some subclasses do override this method.)
//
// Simply calling handleRead() here would be bad, as this would call
// readCallback_->getReadBuffer(), forcing the callback to allocate a read
// buffer even though no data may be available. This would waste lots of
// memory, since the buffer will sit around unused until the socket actually
// becomes readable.
//
// Checking if the socket is readable now also seems like it would probably
// be a pessimism. In most cases it probably wouldn't be readable, and we
// would just waste an extra system call. Even if it is readable, waiting to
// find out from libevent on the next event loop doesn't seem that bad.
//
// The exception to this is if we have pre-received data. In that case there
// is definitely data available immediately.
if (preReceivedData_ && !preReceivedData_->empty()) {
handleRead();
}
}
void AsyncSocket::handleInitialReadWrite() noexcept {
// Our callers should already be holding a DestructorGuard, but grab
// one here just to make sure, in case one of our calling code paths ever
// changes.
DestructorGuard dg(this);
// If we have a readCallback_, make sure we enable read events. We
// may already be registered for reads if connectSuccess() set
// the read calback.
if (readCallback_ && !(eventFlags_ & EventHandler::READ)) {
assert(state_ == StateEnum::ESTABLISHED);
assert((shutdownFlags_ & SHUT_READ) == 0);
if (!updateEventRegistration(EventHandler::READ, 0)) {
assert(state_ == StateEnum::ERROR);
return;
}
checkForImmediateRead();
} else if (readCallback_ == nullptr) {
// Unregister for read events.
updateEventRegistration(0, EventHandler::READ);
}
// If we have write requests pending, try to send them immediately.
// Since we just finished accepting, there is a very good chance that we can
// write without blocking.
//
// However, we only process them if EventHandler::WRITE is not already set,
// which means that we're already blocked on a write attempt. (This can
// happen if connectSuccess() called write() before returning.)
if (writeReqHead_ && !(eventFlags_ & EventHandler::WRITE)) {
// Call handleWrite() to perform write processing.
handleWrite();
} else if (writeReqHead_ == nullptr) {
// Unregister for write event.
updateEventRegistration(0, EventHandler::WRITE);
}
}
void AsyncSocket::handleConnect() noexcept {
VLOG(5) << "AsyncSocket::handleConnect() this=" << this << ", fd=" << fd_
<< ", state=" << state_;
assert(state_ == StateEnum::CONNECTING);
// SHUT_WRITE can never be set while we are still connecting;
// SHUT_WRITE_PENDING may be set, be we only set SHUT_WRITE once the connect
// finishes
assert((shutdownFlags_ & SHUT_WRITE) == 0);
// In case we had a connect timeout, cancel the timeout
writeTimeout_.cancelTimeout();
// We don't use a persistent registration when waiting on a connect event,
// so we have been automatically unregistered now. Update eventFlags_ to
// reflect reality.
assert(eventFlags_ == EventHandler::WRITE);
eventFlags_ = EventHandler::NONE;
// Call getsockopt() to check if the connect succeeded
int error;
socklen_t len = sizeof(error);
int rv = netops::getsockopt(fd_, SOL_SOCKET, SO_ERROR, &error, &len);
if (rv != 0) {
auto errnoCopy = errno;
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("error calling getsockopt() after connect"),
errnoCopy);
VLOG(4) << "AsyncSocket::handleConnect(this=" << this << ", fd=" << fd_
<< " host=" << addr_.describe() << ") exception:" << ex.what();
return failConnect(__func__, ex);
}
if (error != 0) {
AsyncSocketException ex(
AsyncSocketException::NOT_OPEN, "connect failed", error);
VLOG(2) << "AsyncSocket::handleConnect(this=" << this << ", fd=" << fd_
<< " host=" << addr_.describe() << ") exception: " << ex.what();
return failConnect(__func__, ex);
}
// Move into STATE_ESTABLISHED
state_ = StateEnum::ESTABLISHED;
// If SHUT_WRITE_PENDING is set and we don't have any write requests to
// perform, immediately shutdown the write half of the socket.
if ((shutdownFlags_ & SHUT_WRITE_PENDING) && writeReqHead_ == nullptr) {
// SHUT_READ shouldn't be set. If close() is called on the socket while we
// are still connecting we just abort the connect rather than waiting for
// it to complete.
assert((shutdownFlags_ & SHUT_READ) == 0);
netops::shutdown(fd_, SHUT_WR);
shutdownFlags_ |= SHUT_WRITE;
}
VLOG(7) << "AsyncSocket " << this << ": fd " << fd_
<< "successfully connected; state=" << state_;
// Remember the EventBase we are attached to, before we start invoking any
// callbacks (since the callbacks may call detachEventBase()).
EventBase* originalEventBase = eventBase_;
invokeConnectSuccess();
// Note that the connect callback may have changed our state.
// (set or unset the read callback, called write(), closed the socket, etc.)
// The following code needs to handle these situations correctly.
//
// If the socket has been closed, readCallback_ and writeReqHead_ will
// always be nullptr, so that will prevent us from trying to read or write.
//
// The main thing to check for is if eventBase_ is still originalEventBase.
// If not, we have been detached from this event base, so we shouldn't
// perform any more operations.
if (eventBase_ != originalEventBase) {
return;
}
handleInitialReadWrite();
}
void AsyncSocket::timeoutExpired() noexcept {
VLOG(7) << "AsyncSocket " << this << ", fd " << fd_ << ": timeout expired: "
<< "state=" << state_ << ", events=" << std::hex << eventFlags_;
DestructorGuard dg(this);
eventBase_->dcheckIsInEventBaseThread();
if (state_ == StateEnum::CONNECTING) {
// connect() timed out
// Unregister for I/O events.
if (connectCallback_) {
AsyncSocketException ex(
AsyncSocketException::TIMED_OUT,
folly::sformat(
"connect timed out after {}ms", connectTimeout_.count()));
failConnect(__func__, ex);
} else {
// we faced a connect error without a connect callback, which could
// happen due to TFO.
AsyncSocketException ex(
AsyncSocketException::TIMED_OUT, "write timed out during connection");
failWrite(__func__, ex);
}
} else {
// a normal write operation timed out
AsyncSocketException ex(
AsyncSocketException::TIMED_OUT,
folly::sformat("write timed out after {}ms", sendTimeout_));
failWrite(__func__, ex);
}
}
ssize_t
AsyncSocket::tfoSendMsg(NetworkSocket fd, struct msghdr* msg, int msg_flags) {
return detail::tfo_sendmsg(fd, msg, msg_flags);
}
AsyncSocket::WriteResult AsyncSocket::sendSocketMessage(
NetworkSocket fd,
struct msghdr* msg,
int msg_flags) {
ssize_t totalWritten = 0;
if (state_ == StateEnum::FAST_OPEN) {
sockaddr_storage addr;
auto len = addr_.getAddress(&addr);
msg->msg_name = &addr;
msg->msg_namelen = len;
totalWritten = tfoSendMsg(fd_, msg, msg_flags);
if (totalWritten >= 0) {
tfoFinished_ = true;
state_ = StateEnum::ESTABLISHED;
// We schedule this asynchrously so that we don't end up
// invoking initial read or write while a write is in progress.
scheduleInitialReadWrite();
} else if (errno == EINPROGRESS) {
VLOG(4) << "TFO falling back to connecting";
// A normal sendmsg doesn't return EINPROGRESS, however
// TFO might fallback to connecting if there is no
// cookie.
state_ = StateEnum::CONNECTING;
try {
scheduleConnectTimeout();
registerForConnectEvents();
} catch (const AsyncSocketException& ex) {
return WriteResult(
WRITE_ERROR, std::make_unique<AsyncSocketException>(ex));
}
// Let's fake it that no bytes were written and return an errno.
errno = EAGAIN;
totalWritten = -1;
} else if (errno == EOPNOTSUPP) {
// Try falling back to connecting.
VLOG(4) << "TFO not supported";
state_ = StateEnum::CONNECTING;
try {
int ret = socketConnect((const sockaddr*)&addr, len);
if (ret == 0) {
// connect succeeded immediately
// Treat this like no data was written.
state_ = StateEnum::ESTABLISHED;
scheduleInitialReadWrite();
}
// If there was no exception during connections,
// we would return that no bytes were written.
errno = EAGAIN;
totalWritten = -1;
} catch (const AsyncSocketException& ex) {
return WriteResult(
WRITE_ERROR, std::make_unique<AsyncSocketException>(ex));
}
} else if (errno == EAGAIN) {
// Normally sendmsg would indicate that the write would block.
// However in the fast open case, it would indicate that sendmsg
// fell back to a connect. This is a return code from connect()
// instead, and is an error condition indicating no fds available.
return WriteResult(
WRITE_ERROR,
std::make_unique<AsyncSocketException>(
AsyncSocketException::UNKNOWN, "No more free local ports"));
}
} else {
totalWritten = netops::sendmsg(fd, msg, msg_flags);
}
return WriteResult(totalWritten);
}
AsyncSocket::WriteResult AsyncSocket::performWrite(
const iovec* vec,
uint32_t count,
WriteFlags flags,
uint32_t* countWritten,
uint32_t* partialWritten) {
// We use sendmsg() instead of writev() so that we can pass in MSG_NOSIGNAL
// We correctly handle EPIPE errors, so we never want to receive SIGPIPE
// (since it may terminate the program if the main program doesn't explicitly
// ignore it).
struct msghdr msg;
msg.msg_name = nullptr;
msg.msg_namelen = 0;
msg.msg_iov = const_cast<iovec*>(vec);
msg.msg_iovlen = std::min<size_t>(count, kIovMax);
msg.msg_flags = 0;
msg.msg_controllen = sendMsgParamCallback_->getAncillaryDataSize(flags);
CHECK_GE(
AsyncSocket::SendMsgParamsCallback::maxAncillaryDataSize,
msg.msg_controllen);
if (msg.msg_controllen != 0) {
msg.msg_control = reinterpret_cast<char*>(alloca(msg.msg_controllen));
sendMsgParamCallback_->getAncillaryData(flags, msg.msg_control);
} else {
msg.msg_control = nullptr;
}
int msg_flags = sendMsgParamCallback_->getFlags(flags, zeroCopyEnabled_);
auto writeResult = sendSocketMessage(fd_, &msg, msg_flags);
auto totalWritten = writeResult.writeReturn;
if (totalWritten < 0 && zeroCopyEnabled_ && errno == ENOBUFS) {
// workaround for running with zerocopy enabled but without a big enough
// memlock value - see ulimit -l
zeroCopyEnabled_ = false;
zeroCopyReenableCounter_ = zeroCopyReenableThreshold_;
msg_flags = sendMsgParamCallback_->getFlags(flags, zeroCopyEnabled_);
writeResult = sendSocketMessage(fd_, &msg, msg_flags);
totalWritten = writeResult.writeReturn;
}
if (totalWritten < 0) {
bool tryAgain = (errno == EAGAIN);
#ifdef __APPLE__
// Apple has a bug where doing a second write on a socket which we
// have opened with TFO causes an ENOTCONN to be thrown. However the
// socket is really connected, so treat ENOTCONN as a EAGAIN until
// this bug is fixed.
tryAgain |= (errno == ENOTCONN);
#endif
if (!writeResult.exception && tryAgain) {
// TCP buffer is full; we can't write any more data right now.
*countWritten = 0;
*partialWritten = 0;
return WriteResult(0);
}
// error
*countWritten = 0;
*partialWritten = 0;
return writeResult;
}
appBytesWritten_ += totalWritten;
uint32_t bytesWritten;
uint32_t n;
for (bytesWritten = uint32_t(totalWritten), n = 0; n < count; ++n) {
const iovec* v = vec + n;
if (v->iov_len > bytesWritten) {
// Partial write finished in the middle of this iovec
*countWritten = n;
*partialWritten = bytesWritten;
return WriteResult(totalWritten);
}
bytesWritten -= uint32_t(v->iov_len);
}
assert(bytesWritten == 0);
*countWritten = n;
*partialWritten = 0;
return WriteResult(totalWritten);
}
/**
* Re-register the EventHandler after eventFlags_ has changed.
*
* If an error occurs, fail() is called to move the socket into the error state
* and call all currently installed callbacks. After an error, the
* AsyncSocket is completely unregistered.
*
* @return Returns true on success, or false on error.
*/
bool AsyncSocket::updateEventRegistration() {
VLOG(5) << "AsyncSocket::updateEventRegistration(this=" << this
<< ", fd=" << fd_ << ", evb=" << eventBase_ << ", state=" << state_
<< ", events=" << std::hex << eventFlags_;
if (eventFlags_ == EventHandler::NONE) {
if (ioHandler_.isHandlerRegistered()) {
DCHECK(eventBase_ != nullptr);
eventBase_->dcheckIsInEventBaseThread();
}
ioHandler_.unregisterHandler();
return true;
}
eventBase_->dcheckIsInEventBaseThread();
// Always register for persistent events, so we don't have to re-register
// after being called back.
if (!ioHandler_.registerHandler(
uint16_t(eventFlags_ | EventHandler::PERSIST))) {
eventFlags_ = EventHandler::NONE; // we're not registered after error
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("failed to update AsyncSocket event registration"));
fail("updateEventRegistration", ex);
return false;
}
return true;
}
bool AsyncSocket::updateEventRegistration(uint16_t enable, uint16_t disable) {
uint16_t oldFlags = eventFlags_;
eventFlags_ |= enable;
eventFlags_ &= ~disable;
if (eventFlags_ == oldFlags) {
return true;
} else {
return updateEventRegistration();
}
}
void AsyncSocket::startFail() {
// startFail() should only be called once
assert(state_ != StateEnum::ERROR);
assert(getDestructorGuardCount() > 0);
state_ = StateEnum::ERROR;
// Ensure that SHUT_READ and SHUT_WRITE are set,
// so all future attempts to read or write will be rejected
shutdownFlags_ |= (SHUT_READ | SHUT_WRITE);
// Cancel any scheduled immediate read.
if (immediateReadHandler_.isLoopCallbackScheduled()) {
immediateReadHandler_.cancelLoopCallback();
}
if (eventFlags_ != EventHandler::NONE) {
eventFlags_ = EventHandler::NONE;
ioHandler_.unregisterHandler();
}
writeTimeout_.cancelTimeout();
if (fd_ != NetworkSocket()) {
ioHandler_.changeHandlerFD(NetworkSocket());
doClose();
}
}
void AsyncSocket::invokeAllErrors(const AsyncSocketException& ex) {
invokeConnectErr(ex);
failAllWrites(ex);
if (readCallback_) {
ReadCallback* callback = readCallback_;
readCallback_ = nullptr;
callback->readErr(ex);
}
}
void AsyncSocket::finishFail() {
assert(state_ == StateEnum::ERROR);
assert(getDestructorGuardCount() > 0);
AsyncSocketException ex(
AsyncSocketException::INTERNAL_ERROR,
withAddr("socket closing after error"));
invokeAllErrors(ex);
}
void AsyncSocket::finishFail(const AsyncSocketException& ex) {
assert(state_ == StateEnum::ERROR);
assert(getDestructorGuardCount() > 0);
invokeAllErrors(ex);
}
void AsyncSocket::fail(const char* fn, const AsyncSocketException& ex) {
VLOG(4) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< ", state=" << state_ << " host=" << addr_.describe()
<< "): failed in " << fn << "(): " << ex.what();
startFail();
finishFail();
}
void AsyncSocket::failConnect(const char* fn, const AsyncSocketException& ex) {
VLOG(5) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< ", state=" << state_ << " host=" << addr_.describe()
<< "): failed while connecting in " << fn << "(): " << ex.what();
startFail();
invokeConnectErr(ex);
finishFail(ex);
}
void AsyncSocket::failRead(const char* fn, const AsyncSocketException& ex) {
VLOG(5) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< ", state=" << state_ << " host=" << addr_.describe()
<< "): failed while reading in " << fn << "(): " << ex.what();
startFail();
if (readCallback_ != nullptr) {
ReadCallback* callback = readCallback_;
readCallback_ = nullptr;
callback->readErr(ex);
}
finishFail();
}
void AsyncSocket::failErrMessageRead(
const char* fn,
const AsyncSocketException& ex) {
VLOG(5) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< ", state=" << state_ << " host=" << addr_.describe()
<< "): failed while reading message in " << fn << "(): " << ex.what();
startFail();
if (errMessageCallback_ != nullptr) {
ErrMessageCallback* callback = errMessageCallback_;
errMessageCallback_ = nullptr;
callback->errMessageError(ex);
}
finishFail();
}
void AsyncSocket::failWrite(const char* fn, const AsyncSocketException& ex) {
VLOG(5) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< ", state=" << state_ << " host=" << addr_.describe()
<< "): failed while writing in " << fn << "(): " << ex.what();
startFail();
// Only invoke the first write callback, since the error occurred while
// writing this request. Let any other pending write callbacks be invoked in
// finishFail().
if (writeReqHead_ != nullptr) {
WriteRequest* req = writeReqHead_;
writeReqHead_ = req->getNext();
WriteCallback* callback = req->getCallback();
uint32_t bytesWritten = req->getTotalBytesWritten();
req->destroy();
if (callback) {
callback->writeErr(bytesWritten, ex);
}
}
finishFail();
}
void AsyncSocket::failWrite(
const char* fn,
WriteCallback* callback,
size_t bytesWritten,
const AsyncSocketException& ex) {
// This version of failWrite() is used when the failure occurs before
// we've added the callback to writeReqHead_.
VLOG(4) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< ", state=" << state_ << " host=" << addr_.describe()
<< "): failed while writing in " << fn << "(): " << ex.what();
if (closeOnFailedWrite_) {
startFail();
}
if (callback != nullptr) {
callback->writeErr(bytesWritten, ex);
}
if (closeOnFailedWrite_) {
finishFail();
}
}
void AsyncSocket::failAllWrites(const AsyncSocketException& ex) {
// Invoke writeError() on all write callbacks.
// This is used when writes are forcibly shutdown with write requests
// pending, or when an error occurs with writes pending.
while (writeReqHead_ != nullptr) {
WriteRequest* req = writeReqHead_;
writeReqHead_ = req->getNext();
WriteCallback* callback = req->getCallback();
if (callback) {
callback->writeErr(req->getTotalBytesWritten(), ex);
}
req->destroy();
}
// All pending writes have failed - reset totalAppBytesScheduledForWrite_
totalAppBytesScheduledForWrite_ = appBytesWritten_;
}
void AsyncSocket::invalidState(ConnectCallback* callback) {
VLOG(5) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< "): connect() called in invalid state " << state_;
/*
* The invalidState() methods don't use the normal failure mechanisms,
* since we don't know what state we are in. We don't want to call
* startFail()/finishFail() recursively if we are already in the middle of
* cleaning up.
*/
AsyncSocketException ex(
AsyncSocketException::ALREADY_OPEN,
"connect() called with socket in invalid state");
connectEndTime_ = std::chrono::steady_clock::now();
if (state_ == StateEnum::CLOSED || state_ == StateEnum::ERROR) {
if (callback) {
callback->connectErr(ex);
}
} else {
// We can't use failConnect() here since connectCallback_
// may already be set to another callback. Invoke this ConnectCallback
// here; any other connectCallback_ will be invoked in finishFail()
startFail();
if (callback) {
callback->connectErr(ex);
}
finishFail();
}
}
void AsyncSocket::invalidState(ErrMessageCallback* callback) {
VLOG(4) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< "): setErrMessageCB(" << callback << ") called in invalid state "
<< state_;
AsyncSocketException ex(
AsyncSocketException::NOT_OPEN,
msgErrQueueSupported
? "setErrMessageCB() called with socket in invalid state"
: "This platform does not support socket error message notifications");
if (state_ == StateEnum::CLOSED || state_ == StateEnum::ERROR) {
if (callback) {
callback->errMessageError(ex);
}
} else {
startFail();
if (callback) {
callback->errMessageError(ex);
}
finishFail();
}
}
void AsyncSocket::invokeConnectErr(const AsyncSocketException& ex) {
connectEndTime_ = std::chrono::steady_clock::now();
if (connectCallback_) {
ConnectCallback* callback = connectCallback_;
connectCallback_ = nullptr;
callback->connectErr(ex);
}
}
void AsyncSocket::invokeConnectSuccess() {
connectEndTime_ = std::chrono::steady_clock::now();
if (connectCallback_) {
ConnectCallback* callback = connectCallback_;
connectCallback_ = nullptr;
callback->connectSuccess();
}
}
void AsyncSocket::invalidState(ReadCallback* callback) {
VLOG(4) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< "): setReadCallback(" << callback << ") called in invalid state "
<< state_;
AsyncSocketException ex(
AsyncSocketException::NOT_OPEN,
"setReadCallback() called with socket in "
"invalid state");
if (state_ == StateEnum::CLOSED || state_ == StateEnum::ERROR) {
if (callback) {
callback->readErr(ex);
}
} else {
startFail();
if (callback) {
callback->readErr(ex);
}
finishFail();
}
}
void AsyncSocket::invalidState(WriteCallback* callback) {
VLOG(4) << "AsyncSocket(this=" << this << ", fd=" << fd_
<< "): write() called in invalid state " << state_;
AsyncSocketException ex(
AsyncSocketException::NOT_OPEN,
withAddr("write() called with socket in invalid state"));
if (state_ == StateEnum::CLOSED || state_ == StateEnum::ERROR) {
if (callback) {
callback->writeErr(0, ex);
}
} else {
startFail();
if (callback) {
callback->writeErr(0, ex);
}
finishFail();
}
}
void AsyncSocket::doClose() {
if (fd_ == NetworkSocket()) {
return;
}
if (const auto shutdownSocketSet = wShutdownSocketSet_.lock()) {
shutdownSocketSet->close(fd_);
} else {
netops::close(fd_);
}
fd_ = NetworkSocket();
// we also want to clear the zerocopy maps
// if the fd has been closed
idZeroCopyBufPtrMap_.clear();
idZeroCopyBufInfoMap_.clear();
}
std::ostream& operator<<(
std::ostream& os,
const AsyncSocket::StateEnum& state) {
os << static_cast<int>(state);
return os;
}
std::string AsyncSocket::withAddr(folly::StringPiece s) {
// Don't use addr_ directly because it may not be initialized
// e.g. if constructed from fd
folly::SocketAddress peer, local;
try {
getLocalAddress(&local);
} catch (...) {
// ignore
}
try {
getPeerAddress(&peer);
} catch (...) {
// ignore
}
return folly::to<std::string>(
s, " (peer=", peer.describe(), ", local=", local.describe(), ")");
}
void AsyncSocket::setBufferCallback(BufferCallback* cb) {
bufferCallback_ = cb;
}
} // namespace folly