2 * Copyright 2017 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 #include <folly/Optional.h>
20 #include <folly/SocketAddress.h>
21 #include <folly/detail/SocketFastOpen.h>
22 #include <folly/io/IOBuf.h>
23 #include <folly/io/ShutdownSocketSet.h>
24 #include <folly/io/async/AsyncSocketException.h>
25 #include <folly/io/async/AsyncTimeout.h>
26 #include <folly/io/async/AsyncTransport.h>
27 #include <folly/io/async/DelayedDestruction.h>
28 #include <folly/io/async/EventHandler.h>
29 #include <folly/portability/Sockets.h>
31 #include <sys/types.h>
40 * A class for performing asynchronous I/O on a socket.
42 * AsyncSocket allows users to asynchronously wait for data on a socket, and
43 * to asynchronously send data.
45 * The APIs for reading and writing are intentionally asymmetric. Waiting for
46 * data to read is a persistent API: a callback is installed, and is notified
47 * whenever new data is available. It continues to be notified of new events
48 * until it is uninstalled.
50 * AsyncSocket does not provide read timeout functionality, because it
51 * typically cannot determine when the timeout should be active. Generally, a
52 * timeout should only be enabled when processing is blocked waiting on data
53 * from the remote endpoint. For server sockets, the timeout should not be
54 * active if the server is currently processing one or more outstanding
55 * requests for this socket. For client sockets, the timeout should not be
56 * active if there are no requests pending on the socket. Additionally, if a
57 * client has multiple pending requests, it will ususally want a separate
58 * timeout for each request, rather than a single read timeout.
60 * The write API is fairly intuitive: a user can request to send a block of
61 * data, and a callback will be informed once the entire block has been
62 * transferred to the kernel, or on error. AsyncSocket does provide a send
63 * timeout, since most callers want to give up if the remote end stops
64 * responding and no further progress can be made sending the data.
67 #if defined __linux__ && !defined SO_NO_TRANSPARENT_TLS
68 #define SO_NO_TRANSPARENT_TLS 200
71 #if defined __linux__ && !defined SO_NO_TSOCKS
72 #define SO_NO_TSOCKS 201
76 // We do a dynamic_cast on this, in
77 // AsyncTransportWrapper::getUnderlyingTransport so be safe and
78 // force displacements for it. See:
79 // https://msdn.microsoft.com/en-us/library/7sf3txa8.aspx
80 #pragma vtordisp(push, 2)
82 class AsyncSocket : virtual public AsyncTransportWrapper {
84 typedef std::unique_ptr<AsyncSocket, Destructor> UniquePtr;
86 class ConnectCallback {
88 virtual ~ConnectCallback() = default;
91 * connectSuccess() will be invoked when the connection has been
92 * successfully established.
94 virtual void connectSuccess() noexcept = 0;
97 * connectErr() will be invoked if the connection attempt fails.
99 * @param ex An exception describing the error that occurred.
101 virtual void connectErr(const AsyncSocketException& ex)
105 class EvbChangeCallback {
107 virtual ~EvbChangeCallback() = default;
109 // Called when the socket has been attached to a new EVB
110 // and is called from within that EVB thread
111 virtual void evbAttached(AsyncSocket* socket) = 0;
113 // Called when the socket is detached from an EVB and
114 // is called from the EVB thread being detached
115 virtual void evbDetached(AsyncSocket* socket) = 0;
119 * This interface is implemented only for platforms supporting
120 * per-socket error queues.
122 class ErrMessageCallback {
124 virtual ~ErrMessageCallback() = default;
127 * errMessage() will be invoked when kernel puts a message to
128 * the error queue associated with the socket.
130 * @param cmsg Reference to cmsghdr structure describing
131 * a message read from error queue associated
135 errMessage(const cmsghdr& cmsg) noexcept = 0;
138 * errMessageError() will be invoked if an error occurs reading a message
139 * from the socket error stream.
141 * @param ex An exception describing the error that occurred.
143 virtual void errMessageError(const AsyncSocketException& ex) noexcept = 0;
146 class SendMsgParamsCallback {
148 virtual ~SendMsgParamsCallback() = default;
151 * getFlags() will be invoked to retrieve the desired flags to be passed
152 * to ::sendmsg() system call. This method was intentionally declared
153 * non-virtual, so there is no way to override it. Instead feel free to
154 * override getFlagsImpl(flags, defaultFlags) method instead, and enjoy
155 * the convenience of defaultFlags passed there.
157 * @param flags Write flags requested for the given write operation
159 int getFlags(folly::WriteFlags flags) noexcept {
160 return getFlagsImpl(flags, getDefaultFlags(flags));
164 * getAncillaryData() will be invoked to initialize ancillary data
165 * buffer referred by "msg_control" field of msghdr structure passed to
166 * ::sendmsg() system call. The function assumes that the size of buffer
167 * is not smaller than the value returned by getAncillaryDataSize() method
168 * for the same combination of flags.
170 * @param flags Write flags requested for the given write operation
171 * @param data Pointer to ancillary data buffer to initialize.
173 virtual void getAncillaryData(
174 folly::WriteFlags /*flags*/,
175 void* /*data*/) noexcept {}
178 * getAncillaryDataSize() will be invoked to retrieve the size of
179 * ancillary data buffer which should be passed to ::sendmsg() system call
181 * @param flags Write flags requested for the given write operation
183 virtual uint32_t getAncillaryDataSize(folly::WriteFlags /*flags*/)
188 static const size_t maxAncillaryDataSize{0x5000};
192 * getFlagsImpl() will be invoked by getFlags(folly::WriteFlags flags)
193 * method to retrieve the flags to be passed to ::sendmsg() system call.
194 * SendMsgParamsCallback::getFlags() is calling this method, and returns
195 * its results directly to the caller in AsyncSocket.
196 * Classes inheriting from SendMsgParamsCallback are welcome to override
197 * this method to force SendMsgParamsCallback to return its own set
200 * @param flags Write flags requested for the given write operation
201 * @param defaultflags A set of message flags returned by getDefaultFlags()
202 * method for the given "flags" mask.
204 virtual int getFlagsImpl(folly::WriteFlags /*flags*/, int defaultFlags) {
209 * getDefaultFlags() will be invoked by getFlags(folly::WriteFlags flags)
210 * to retrieve the default set of flags, and pass them to getFlagsImpl(...)
212 * @param flags Write flags requested for the given write operation
214 int getDefaultFlags(folly::WriteFlags flags) noexcept;
217 explicit AsyncSocket();
219 * Create a new unconnected AsyncSocket.
221 * connect() must later be called on this socket to establish a connection.
223 explicit AsyncSocket(EventBase* evb);
225 void setShutdownSocketSet(ShutdownSocketSet* ss);
228 * Create a new AsyncSocket and begin the connection process.
230 * @param evb EventBase that will manage this socket.
231 * @param address The address to connect to.
232 * @param connectTimeout Optional timeout in milliseconds for the connection
235 AsyncSocket(EventBase* evb,
236 const folly::SocketAddress& address,
237 uint32_t connectTimeout = 0);
240 * Create a new AsyncSocket and begin the connection process.
242 * @param evb EventBase that will manage this socket.
243 * @param ip IP address to connect to (dotted-quad).
244 * @param port Destination port in host byte order.
245 * @param connectTimeout Optional timeout in milliseconds for the connection
248 AsyncSocket(EventBase* evb,
249 const std::string& ip,
251 uint32_t connectTimeout = 0);
254 * Create a AsyncSocket from an already connected socket file descriptor.
256 * Note that while AsyncSocket enables TCP_NODELAY for sockets it creates
257 * when connecting, it does not change the socket options when given an
258 * existing file descriptor. If callers want TCP_NODELAY enabled when using
259 * this version of the constructor, they need to explicitly call
260 * setNoDelay(true) after the constructor returns.
262 * @param evb EventBase that will manage this socket.
263 * @param fd File descriptor to take over (should be a connected socket).
265 AsyncSocket(EventBase* evb, int fd);
268 * Create an AsyncSocket from a different, already connected AsyncSocket.
270 * Similar to AsyncSocket(evb, fd) when fd was previously owned by an
273 explicit AsyncSocket(AsyncSocket::UniquePtr);
276 * Helper function to create a shared_ptr<AsyncSocket>.
278 * This passes in the correct destructor object, since AsyncSocket's
279 * destructor is protected and cannot be invoked directly.
281 static std::shared_ptr<AsyncSocket> newSocket(EventBase* evb) {
282 return std::shared_ptr<AsyncSocket>(new AsyncSocket(evb),
287 * Helper function to create a shared_ptr<AsyncSocket>.
289 static std::shared_ptr<AsyncSocket> newSocket(
291 const folly::SocketAddress& address,
292 uint32_t connectTimeout = 0) {
293 return std::shared_ptr<AsyncSocket>(
294 new AsyncSocket(evb, address, connectTimeout),
299 * Helper function to create a shared_ptr<AsyncSocket>.
301 static std::shared_ptr<AsyncSocket> newSocket(
303 const std::string& ip,
305 uint32_t connectTimeout = 0) {
306 return std::shared_ptr<AsyncSocket>(
307 new AsyncSocket(evb, ip, port, connectTimeout),
312 * Helper function to create a shared_ptr<AsyncSocket>.
314 static std::shared_ptr<AsyncSocket> newSocket(EventBase* evb, int fd) {
315 return std::shared_ptr<AsyncSocket>(new AsyncSocket(evb, fd),
320 * Destroy the socket.
322 * AsyncSocket::destroy() must be called to destroy the socket.
323 * The normal destructor is private, and should not be invoked directly.
324 * This prevents callers from deleting a AsyncSocket while it is invoking a
327 void destroy() override;
330 * Get the EventBase used by this socket.
332 EventBase* getEventBase() const override {
337 * Get the file descriptor used by the AsyncSocket.
339 virtual int getFd() const {
344 * Extract the file descriptor from the AsyncSocket.
346 * This will immediately cause any installed callbacks to be invoked with an
347 * error. The AsyncSocket may no longer be used after the file descriptor
348 * has been extracted.
350 * This method should be used with care as the resulting fd is not guaranteed
351 * to perfectly reflect the state of the AsyncSocket (security state,
352 * pre-received data, etc.).
354 * Returns the file descriptor. The caller assumes ownership of the
355 * descriptor, and it will not be closed when the AsyncSocket is destroyed.
357 virtual int detachFd();
360 * Uniquely identifies a handle to a socket option value. Each
361 * combination of level and option name corresponds to one socket
366 bool operator<(const OptionKey& other) const {
367 if (level == other.level) {
368 return optname < other.optname;
370 return level < other.level;
372 int apply(int fd, int val) const {
373 return setsockopt(fd, level, optname, &val, sizeof(val));
379 // Maps from a socket option key to its value
380 typedef std::map<OptionKey, int> OptionMap;
382 static const OptionMap emptyOptionMap;
383 static const folly::SocketAddress& anyAddress();
386 * Initiate a connection.
388 * @param callback The callback to inform when the connection attempt
390 * @param address The address to connect to.
391 * @param timeout A timeout value, in milliseconds. If the connection
392 * does not succeed within this period,
393 * callback->connectError() will be invoked.
395 virtual void connect(
396 ConnectCallback* callback,
397 const folly::SocketAddress& address,
399 const OptionMap& options = emptyOptionMap,
400 const folly::SocketAddress& bindAddr = anyAddress()) noexcept;
403 ConnectCallback* callback,
404 const std::string& ip,
407 const OptionMap& options = emptyOptionMap) noexcept;
410 * If a connect request is in-flight, cancels it and closes the socket
411 * immediately. Otherwise, this is a no-op.
413 * This does not invoke any connection related callbacks. Call this to
414 * prevent any connect callback while cleaning up, etc.
416 void cancelConnect();
419 * Set the send timeout.
421 * If write requests do not make any progress for more than the specified
422 * number of milliseconds, fail all pending writes and close the socket.
424 * If write requests are currently pending when setSendTimeout() is called,
425 * the timeout interval is immediately restarted using the new value.
427 * (See the comments for AsyncSocket for an explanation of why AsyncSocket
428 * provides setSendTimeout() but not setRecvTimeout().)
430 * @param milliseconds The timeout duration, in milliseconds. If 0, no
431 * timeout will be used.
433 void setSendTimeout(uint32_t milliseconds) override;
436 * Get the send timeout.
438 * @return Returns the current send timeout, in milliseconds. A return value
439 * of 0 indicates that no timeout is set.
441 uint32_t getSendTimeout() const override {
446 * Set the maximum number of reads to execute from the underlying
447 * socket each time the EventBase detects that new ingress data is
448 * available. The default is unlimited, but callers can use this method
449 * to limit the amount of data read from the socket per event loop
452 * @param maxReads Maximum number of reads per data-available event;
453 * a value of zero means unlimited.
455 void setMaxReadsPerEvent(uint16_t maxReads) {
456 maxReadsPerEvent_ = maxReads;
460 * Get the maximum number of reads this object will execute from
461 * the underlying socket each time the EventBase detects that new
462 * ingress data is available.
464 * @returns Maximum number of reads per data-available event; a value
465 * of zero means unlimited.
467 uint16_t getMaxReadsPerEvent() const {
468 return maxReadsPerEvent_;
472 * Set a pointer to ErrMessageCallback implementation which will be
473 * receiving notifications for messages posted to the error queue
474 * associated with the socket.
475 * ErrMessageCallback is implemented only for platforms with
476 * per-socket error message queus support (recvmsg() system call must
480 virtual void setErrMessageCB(ErrMessageCallback* callback);
483 * Get a pointer to ErrMessageCallback implementation currently
484 * registered with this socket.
487 virtual ErrMessageCallback* getErrMessageCallback() const;
490 * Set a pointer to SendMsgParamsCallback implementation which
491 * will be used to form ::sendmsg() system call parameters
494 virtual void setSendMsgParamCB(SendMsgParamsCallback* callback);
497 * Get a pointer to SendMsgParamsCallback implementation currently
498 * registered with this socket.
501 virtual SendMsgParamsCallback* getSendMsgParamsCB() const;
503 // Read and write methods
504 void setReadCB(ReadCallback* callback) override;
505 ReadCallback* getReadCallback() const override;
507 void write(WriteCallback* callback, const void* buf, size_t bytes,
508 WriteFlags flags = WriteFlags::NONE) override;
509 void writev(WriteCallback* callback, const iovec* vec, size_t count,
510 WriteFlags flags = WriteFlags::NONE) override;
511 void writeChain(WriteCallback* callback,
512 std::unique_ptr<folly::IOBuf>&& buf,
513 WriteFlags flags = WriteFlags::NONE) override;
516 virtual void writeRequest(WriteRequest* req);
517 void writeRequestReady() {
521 // Methods inherited from AsyncTransport
522 void close() override;
523 void closeNow() override;
524 void closeWithReset() override;
525 void shutdownWrite() override;
526 void shutdownWriteNow() override;
528 bool readable() const override;
529 bool writable() const override;
530 bool isPending() const override;
531 virtual bool hangup() const;
532 bool good() const override;
533 bool error() const override;
534 void attachEventBase(EventBase* eventBase) override;
535 void detachEventBase() override;
536 bool isDetachable() const override;
538 void getLocalAddress(
539 folly::SocketAddress* address) const override;
541 folly::SocketAddress* address) const override;
543 bool isEorTrackingEnabled() const override {
547 void setEorTracking(bool track) override {
551 bool connecting() const override {
552 return (state_ == StateEnum::CONNECTING);
555 virtual bool isClosedByPeer() const {
556 return (state_ == StateEnum::CLOSED &&
557 (readErr_ == READ_EOF || readErr_ == READ_ERROR));
560 virtual bool isClosedBySelf() const {
561 return (state_ == StateEnum::CLOSED &&
562 (readErr_ != READ_EOF && readErr_ != READ_ERROR));
565 size_t getAppBytesWritten() const override {
566 return appBytesWritten_;
569 size_t getRawBytesWritten() const override {
570 return getAppBytesWritten();
573 size_t getAppBytesReceived() const override {
574 return appBytesReceived_;
577 size_t getRawBytesReceived() const override {
578 return getAppBytesReceived();
581 std::chrono::nanoseconds getConnectTime() const {
582 return connectEndTime_ - connectStartTime_;
585 std::chrono::milliseconds getConnectTimeout() const {
586 return connectTimeout_;
589 bool getTFOAttempted() const {
590 return tfoAttempted_;
594 * Returns whether or not the attempt to use TFO
595 * finished successfully. This does not necessarily
596 * mean TFO worked, just that trying to use TFO
599 bool getTFOFinished() const {
604 * Returns whether or not TFO attempt succeded on this
606 * For servers this is pretty straightforward API and can
607 * be invoked right after the connection is accepted. This API
608 * will perform one syscall.
609 * This API is a bit tricky to use for clients, since clients
610 * only know this for sure after the SYN-ACK is returned. So it's
611 * appropriate to call this only after the first application
612 * data is read from the socket when the caller knows that
613 * the SYN has been ACKed by the server.
615 bool getTFOSucceded() const;
617 // Methods controlling socket options
620 * Force writes to be transmitted immediately.
622 * This controls the TCP_NODELAY socket option. When enabled, TCP segments
623 * are sent as soon as possible, even if it is not a full frame of data.
624 * When disabled, the data may be buffered briefly to try and wait for a full
627 * By default, TCP_NODELAY is enabled for AsyncSocket objects.
629 * This method will fail if the socket is not currently open.
631 * @return Returns 0 if the TCP_NODELAY flag was successfully updated,
632 * or a non-zero errno value on error.
634 int setNoDelay(bool noDelay);
638 * Set the FD_CLOEXEC flag so that the socket will be closed if the program
639 * later forks and execs.
641 void setCloseOnExec();
644 * Set the Flavor of Congestion Control to be used for this Socket
645 * Please check '/lib/modules/<kernel>/kernel/net/ipv4' for tcp_*.ko
646 * first to make sure the module is available for plugging in
647 * Alternatively you can choose from net.ipv4.tcp_allowed_congestion_control
649 int setCongestionFlavor(const std::string &cname);
652 * Forces ACKs to be sent immediately
654 * @return Returns 0 if the TCP_QUICKACK flag was successfully updated,
655 * or a non-zero errno value on error.
657 int setQuickAck(bool quickack);
660 * Set the send bufsize
662 int setSendBufSize(size_t bufsize);
665 * Set the recv bufsize
667 int setRecvBufSize(size_t bufsize);
670 * Sets a specific tcp personality
671 * Available only on kernels 3.2 and greater
673 #define SO_SET_NAMESPACE 41
674 int setTCPProfile(int profd);
677 * Generic API for reading a socket option.
679 * @param level same as the "level" parameter in getsockopt().
680 * @param optname same as the "optname" parameter in getsockopt().
681 * @param optval pointer to the variable in which the option value should
683 * @param optlen value-result argument, initially containing the size of
684 * the buffer pointed to by optval, and modified on return
685 * to indicate the actual size of the value returned.
686 * @return same as the return value of getsockopt().
688 template <typename T>
689 int getSockOpt(int level, int optname, T* optval, socklen_t* optlen) {
690 return getsockopt(fd_, level, optname, (void*) optval, optlen);
694 * Generic API for setting a socket option.
696 * @param level same as the "level" parameter in getsockopt().
697 * @param optname same as the "optname" parameter in getsockopt().
698 * @param optval the option value to set.
699 * @return same as the return value of setsockopt().
701 template <typename T>
702 int setSockOpt(int level, int optname, const T *optval) {
703 return setsockopt(fd_, level, optname, optval, sizeof(T));
707 * Virtual method for reading a socket option returning integer
708 * value, which is the most typical case. Convenient for overriding
711 * @param level same as the "level" parameter in getsockopt().
712 * @param optname same as the "optname" parameter in getsockopt().
713 * @param optval same as "optval" parameter in getsockopt().
714 * @param optlen same as "optlen" parameter in getsockopt().
715 * @return same as the return value of getsockopt().
718 getSockOptVirtual(int level, int optname, void* optval, socklen_t* optlen) {
719 return getsockopt(fd_, level, optname, optval, optlen);
723 * Virtual method for setting a socket option accepting integer
724 * value, which is the most typical case. Convenient for overriding
727 * @param level same as the "level" parameter in setsockopt().
728 * @param optname same as the "optname" parameter in setsockopt().
729 * @param optval same as "optval" parameter in setsockopt().
730 * @param optlen same as "optlen" parameter in setsockopt().
731 * @return same as the return value of setsockopt().
733 virtual int setSockOptVirtual(
738 return setsockopt(fd_, level, optname, optval, optlen);
742 * Set pre-received data, to be returned to read callback before any data
745 virtual void setPreReceivedData(std::unique_ptr<IOBuf> data) {
746 if (preReceivedData_) {
747 preReceivedData_->prependChain(std::move(data));
749 preReceivedData_ = std::move(data);
754 * Enables TFO behavior on the AsyncSocket if FOLLY_ALLOW_TFO
758 // No-op if folly does not allow tfo
764 void disableTransparentTls() {
765 noTransparentTls_ = true;
768 void disableTSocks() {
772 enum class StateEnum : uint8_t {
781 void setBufferCallback(BufferCallback* cb);
783 // Callers should set this prior to connecting the socket for the safest
785 void setEvbChangedCallback(std::unique_ptr<EvbChangeCallback> cb) {
786 evbChangeCb_ = std::move(cb);
790 * Attempt to cache the current local and peer addresses (if not already
791 * cached) so that they are available from getPeerAddress() and
792 * getLocalAddress() even after the socket is closed.
794 void cacheAddresses();
797 * writeReturn is the total number of bytes written, or WRITE_ERROR on error.
798 * If no data has been written, 0 is returned.
799 * exception is a more specific exception that cause a write error.
800 * Not all writes have exceptions associated with them thus writeReturn
801 * should be checked to determine whether the operation resulted in an error.
804 explicit WriteResult(ssize_t ret) : writeReturn(ret) {}
806 WriteResult(ssize_t ret, std::unique_ptr<const AsyncSocketException> e)
807 : writeReturn(ret), exception(std::move(e)) {}
810 std::unique_ptr<const AsyncSocketException> exception;
814 * readReturn is the number of bytes read, or READ_EOF on EOF, or
815 * READ_ERROR on error, or READ_BLOCKING if the operation will
817 * exception is a more specific exception that may have caused a read error.
818 * Not all read errors have exceptions associated with them thus readReturn
819 * should be checked to determine whether the operation resulted in an error.
822 explicit ReadResult(ssize_t ret) : readReturn(ret) {}
824 ReadResult(ssize_t ret, std::unique_ptr<const AsyncSocketException> e)
825 : readReturn(ret), exception(std::move(e)) {}
828 std::unique_ptr<const AsyncSocketException> exception;
832 * A WriteRequest object tracks information about a pending write operation.
836 WriteRequest(AsyncSocket* socket, WriteCallback* callback) :
837 socket_(socket), callback_(callback) {}
839 virtual void start() {}
841 virtual void destroy() = 0;
843 virtual WriteResult performWrite() = 0;
845 virtual void consume() = 0;
847 virtual bool isComplete() = 0;
849 WriteRequest* getNext() const {
853 WriteCallback* getCallback() const {
857 uint32_t getTotalBytesWritten() const {
858 return totalBytesWritten_;
861 void append(WriteRequest* next) {
862 assert(next_ == nullptr);
866 void fail(const char* fn, const AsyncSocketException& ex) {
867 socket_->failWrite(fn, ex);
870 void bytesWritten(size_t count) {
871 totalBytesWritten_ += uint32_t(count);
872 socket_->appBytesWritten_ += count;
876 // protected destructor, to ensure callers use destroy()
877 virtual ~WriteRequest() {}
879 AsyncSocket* socket_; ///< parent socket
880 WriteRequest* next_{nullptr}; ///< pointer to next WriteRequest
881 WriteCallback* callback_; ///< completion callback
882 uint32_t totalBytesWritten_{0}; ///< total bytes written
886 enum ReadResultEnum {
893 enum WriteResultEnum {
898 * Protected destructor.
900 * Users of AsyncSocket must never delete it directly. Instead, invoke
901 * destroy() instead. (See the documentation in DelayedDestruction.h for
904 ~AsyncSocket() override;
906 friend std::ostream& operator << (std::ostream& os, const StateEnum& state);
909 /// shutdownWrite() called, but we are still waiting on writes to drain
910 SHUT_WRITE_PENDING = 0x01,
911 /// writes have been completely shut down
914 * Reads have been shutdown.
916 * At the moment we don't distinguish between remote read shutdown
917 * (received EOF from the remote end) and local read shutdown. We can
918 * only receive EOF when a read callback is set, and we immediately inform
919 * it of the EOF. Therefore there doesn't seem to be any reason to have a
920 * separate state of "received EOF but the local side may still want to
923 * We also don't currently provide any API for only shutting down the read
924 * side of a socket. (This is a no-op as far as TCP is concerned, anyway.)
929 class BytesWriteRequest;
931 class WriteTimeout : public AsyncTimeout {
933 WriteTimeout(AsyncSocket* socket, EventBase* eventBase)
934 : AsyncTimeout(eventBase)
937 void timeoutExpired() noexcept override {
938 socket_->timeoutExpired();
942 AsyncSocket* socket_;
945 class IoHandler : public EventHandler {
947 IoHandler(AsyncSocket* socket, EventBase* eventBase)
948 : EventHandler(eventBase, -1)
950 IoHandler(AsyncSocket* socket, EventBase* eventBase, int fd)
951 : EventHandler(eventBase, fd)
954 void handlerReady(uint16_t events) noexcept override {
955 socket_->ioReady(events);
959 AsyncSocket* socket_;
964 class ImmediateReadCB : public folly::EventBase::LoopCallback {
966 explicit ImmediateReadCB(AsyncSocket* socket) : socket_(socket) {}
967 void runLoopCallback() noexcept override {
968 DestructorGuard dg(socket_);
969 socket_->checkForImmediateRead();
972 AsyncSocket* socket_;
976 * Schedule checkForImmediateRead to be executed in the next loop
979 void scheduleImmediateRead() noexcept {
981 eventBase_->runInLoop(&immediateReadHandler_);
986 * Schedule handleInitalReadWrite to run in the next iteration.
988 void scheduleInitialReadWrite() noexcept {
990 DestructorGuard dg(this);
991 eventBase_->runInLoop([this, dg] {
993 handleInitialReadWrite();
999 // event notification methods
1000 void ioReady(uint16_t events) noexcept;
1001 virtual void checkForImmediateRead() noexcept;
1002 virtual void handleInitialReadWrite() noexcept;
1003 virtual void prepareReadBuffer(void** buf, size_t* buflen);
1004 virtual void handleErrMessages() noexcept;
1005 virtual void handleRead() noexcept;
1006 virtual void handleWrite() noexcept;
1007 virtual void handleConnect() noexcept;
1008 void timeoutExpired() noexcept;
1011 * Attempt to read from the socket.
1013 * @param buf The buffer to read data into.
1014 * @param buflen The length of the buffer.
1016 * @return Returns a read result. See read result for details.
1018 virtual ReadResult performRead(void** buf, size_t* buflen, size_t* offset);
1021 * Populate an iovec array from an IOBuf and attempt to write it.
1023 * @param callback Write completion/error callback.
1024 * @param vec Target iovec array; caller retains ownership.
1025 * @param count Number of IOBufs to write, beginning at start of buf.
1026 * @param buf Chain of iovecs.
1027 * @param flags set of flags for the underlying write calls, like cork
1029 void writeChainImpl(WriteCallback* callback, iovec* vec,
1030 size_t count, std::unique_ptr<folly::IOBuf>&& buf,
1034 * Write as much data as possible to the socket without blocking,
1035 * and queue up any leftover data to send when the socket can
1036 * handle writes again.
1038 * @param callback The callback to invoke when the write is completed.
1039 * @param vec Array of buffers to write; this method will make a
1040 * copy of the vector (but not the buffers themselves)
1041 * if the write has to be completed asynchronously.
1042 * @param count Number of elements in vec.
1043 * @param buf The IOBuf that manages the buffers referenced by
1044 * vec, or a pointer to nullptr if the buffers are not
1045 * associated with an IOBuf. Note that ownership of
1046 * the IOBuf is transferred here; upon completion of
1047 * the write, the AsyncSocket deletes the IOBuf.
1048 * @param flags Set of write flags.
1050 void writeImpl(WriteCallback* callback, const iovec* vec, size_t count,
1051 std::unique_ptr<folly::IOBuf>&& buf,
1052 WriteFlags flags = WriteFlags::NONE);
1055 * Attempt to write to the socket.
1057 * @param vec The iovec array pointing to the buffers to write.
1058 * @param count The length of the iovec array.
1059 * @param flags Set of write flags.
1060 * @param countWritten On return, the value pointed to by this parameter
1061 * will contain the number of iovec entries that were
1063 * @param partialWritten On return, the value pointed to by this parameter
1064 * will contain the number of bytes written in the
1065 * partially written iovec entry.
1067 * @return Returns a WriteResult. See WriteResult for more details.
1069 virtual WriteResult performWrite(
1073 uint32_t* countWritten,
1074 uint32_t* partialWritten);
1077 * Sends the message over the socket using sendmsg
1079 * @param msg Message to send
1080 * @param msg_flags Flags to pass to sendmsg
1082 AsyncSocket::WriteResult
1083 sendSocketMessage(int fd, struct msghdr* msg, int msg_flags);
1085 virtual ssize_t tfoSendMsg(int fd, struct msghdr* msg, int msg_flags);
1087 int socketConnect(const struct sockaddr* addr, socklen_t len);
1089 virtual void scheduleConnectTimeout();
1090 void registerForConnectEvents();
1092 bool updateEventRegistration();
1095 * Update event registration.
1097 * @param enable Flags of events to enable. Set it to 0 if no events
1098 * need to be enabled in this call.
1099 * @param disable Flags of events
1100 * to disable. Set it to 0 if no events need to be disabled in this
1103 * @return true iff the update is successful.
1105 bool updateEventRegistration(uint16_t enable, uint16_t disable);
1107 // Actually close the file descriptor and set it to -1 so we don't
1108 // accidentally close it again.
1111 // error handling methods
1114 void finishFail(const AsyncSocketException& ex);
1115 void invokeAllErrors(const AsyncSocketException& ex);
1116 void fail(const char* fn, const AsyncSocketException& ex);
1117 void failConnect(const char* fn, const AsyncSocketException& ex);
1118 void failRead(const char* fn, const AsyncSocketException& ex);
1119 void failErrMessageRead(const char* fn, const AsyncSocketException& ex);
1120 void failWrite(const char* fn, WriteCallback* callback, size_t bytesWritten,
1121 const AsyncSocketException& ex);
1122 void failWrite(const char* fn, const AsyncSocketException& ex);
1123 void failAllWrites(const AsyncSocketException& ex);
1124 virtual void invokeConnectErr(const AsyncSocketException& ex);
1125 virtual void invokeConnectSuccess();
1126 void invalidState(ConnectCallback* callback);
1127 void invalidState(ErrMessageCallback* callback);
1128 void invalidState(ReadCallback* callback);
1129 void invalidState(WriteCallback* callback);
1131 std::string withAddr(const std::string& s);
1133 void cacheLocalAddress() const;
1134 void cachePeerAddress() const;
1136 StateEnum state_; ///< StateEnum describing current state
1137 uint8_t shutdownFlags_; ///< Shutdown state (ShutdownFlags)
1138 uint16_t eventFlags_; ///< EventBase::HandlerFlags settings
1139 int fd_; ///< The socket file descriptor
1140 mutable folly::SocketAddress addr_; ///< The address we tried to connect to
1141 mutable folly::SocketAddress localAddr_;
1142 ///< The address we are connecting from
1143 uint32_t sendTimeout_; ///< The send timeout, in milliseconds
1144 uint16_t maxReadsPerEvent_; ///< Max reads per event loop iteration
1145 EventBase* eventBase_; ///< The EventBase
1146 WriteTimeout writeTimeout_; ///< A timeout for connect and write
1147 IoHandler ioHandler_; ///< A EventHandler to monitor the fd
1148 ImmediateReadCB immediateReadHandler_; ///< LoopCallback for checking read
1150 ConnectCallback* connectCallback_; ///< ConnectCallback
1151 ErrMessageCallback* errMessageCallback_; ///< TimestampCallback
1152 SendMsgParamsCallback* ///< Callback for retreaving
1153 sendMsgParamCallback_; ///< ::sendmsg() parameters
1154 ReadCallback* readCallback_; ///< ReadCallback
1155 WriteRequest* writeReqHead_; ///< Chain of WriteRequests
1156 WriteRequest* writeReqTail_; ///< End of WriteRequest chain
1157 ShutdownSocketSet* shutdownSocketSet_;
1158 size_t appBytesReceived_; ///< Num of bytes received from socket
1159 size_t appBytesWritten_; ///< Num of bytes written to socket
1160 bool isBufferMovable_{false};
1162 // Pre-received data, to be returned to read callback before any data from the
1164 std::unique_ptr<IOBuf> preReceivedData_;
1166 int8_t readErr_{READ_NO_ERROR}; ///< The read error encountered, if any
1168 std::chrono::steady_clock::time_point connectStartTime_;
1169 std::chrono::steady_clock::time_point connectEndTime_;
1171 std::chrono::milliseconds connectTimeout_{0};
1173 BufferCallback* bufferCallback_{nullptr};
1174 bool tfoEnabled_{false};
1175 bool tfoAttempted_{false};
1176 bool tfoFinished_{false};
1177 bool noTransparentTls_{false};
1178 bool noTSocks_{false};
1179 // Whether to track EOR or not.
1180 bool trackEor_{false};
1182 std::unique_ptr<EvbChangeCallback> evbChangeCb_{nullptr};
1185 #pragma vtordisp(pop)