/*
* 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.
*/
#pragma once
#include <folly/Optional.h>
#include <folly/SocketAddress.h>
#include <folly/detail/SocketFastOpen.h>
#include <folly/io/IOBuf.h>
#include <folly/io/ShutdownSocketSet.h>
#include <folly/io/SocketOptionMap.h>
#include <folly/io/async/AsyncSocketException.h>
#include <folly/io/async/AsyncTimeout.h>
#include <folly/io/async/AsyncTransport.h>
#include <folly/io/async/DelayedDestruction.h>
#include <folly/io/async/EventHandler.h>
#include <folly/portability/Sockets.h>
#include <sys/types.h>
#include <chrono>
#include <map>
#include <memory>
namespace folly {
/**
* A class for performing asynchronous I/O on a socket.
*
* AsyncSocket allows users to asynchronously wait for data on a socket, and
* to asynchronously send data.
*
* The APIs for reading and writing are intentionally asymmetric. Waiting for
* data to read is a persistent API: a callback is installed, and is notified
* whenever new data is available. It continues to be notified of new events
* until it is uninstalled.
*
* AsyncSocket does not provide read timeout functionality, because it
* typically cannot determine when the timeout should be active. Generally, a
* timeout should only be enabled when processing is blocked waiting on data
* from the remote endpoint. For server sockets, the timeout should not be
* active if the server is currently processing one or more outstanding
* requests for this socket. For client sockets, the timeout should not be
* active if there are no requests pending on the socket. Additionally, if a
* client has multiple pending requests, it will ususally want a separate
* timeout for each request, rather than a single read timeout.
*
* The write API is fairly intuitive: a user can request to send a block of
* data, and a callback will be informed once the entire block has been
* transferred to the kernel, or on error. AsyncSocket does provide a send
* timeout, since most callers want to give up if the remote end stops
* responding and no further progress can be made sending the data.
*/
#if defined __linux__ && !defined SO_NO_TRANSPARENT_TLS
#define SO_NO_TRANSPARENT_TLS 200
#endif
#if defined __linux__ && !defined SO_NO_TSOCKS
#define SO_NO_TSOCKS 201
#endif
#ifdef _MSC_VER
// We do a dynamic_cast on this, in
// AsyncTransportWrapper::getUnderlyingTransport so be safe and
// force displacements for it. See:
// https://msdn.microsoft.com/en-us/library/7sf3txa8.aspx
#pragma vtordisp(push, 2)
#endif
class AsyncSocket : virtual public AsyncTransportWrapper {
public:
using UniquePtr = std::unique_ptr<AsyncSocket, Destructor>;
class ConnectCallback {
public:
virtual ~ConnectCallback() = default;
/**
* connectSuccess() will be invoked when the connection has been
* successfully established.
*/
virtual void connectSuccess() noexcept = 0;
/**
* connectErr() will be invoked if the connection attempt fails.
*
* @param ex An exception describing the error that occurred.
*/
virtual void connectErr(const AsyncSocketException& ex) noexcept = 0;
/**
* preConnect() will be invoked just before the actual connect happens,
* default is no-ops.
*
* @param fd An underneath created socket, use for connection.
*
*/
virtual void preConnect(NetworkSocket /*fd*/) {}
};
class EvbChangeCallback {
public:
virtual ~EvbChangeCallback() = default;
// Called when the socket has been attached to a new EVB
// and is called from within that EVB thread
virtual void evbAttached(AsyncSocket* socket) = 0;
// Called when the socket is detached from an EVB and
// is called from the EVB thread being detached
virtual void evbDetached(AsyncSocket* socket) = 0;
};
/**
* This interface is implemented only for platforms supporting
* per-socket error queues.
*/
class ErrMessageCallback {
public:
virtual ~ErrMessageCallback() = default;
/**
* errMessage() will be invoked when kernel puts a message to
* the error queue associated with the socket.
*
* @param cmsg Reference to cmsghdr structure describing
* a message read from error queue associated
* with the socket.
*/
virtual void errMessage(const cmsghdr& cmsg) noexcept = 0;
/**
* errMessageError() will be invoked if an error occurs reading a message
* from the socket error stream.
*
* @param ex An exception describing the error that occurred.
*/
virtual void errMessageError(const AsyncSocketException& ex) noexcept = 0;
};
class SendMsgParamsCallback {
public:
virtual ~SendMsgParamsCallback() = default;
/**
* getFlags() will be invoked to retrieve the desired flags to be passed
* to ::sendmsg() system call. It is responsible for converting flags set in
* the passed folly::WriteFlags enum into a integer flag bitmask that can be
* passed to ::sendmsg. Some flags in folly::WriteFlags do not correspond to
* flags that can be passed to ::sendmsg and may instead be handled via
* getAncillaryData.
*
* This method was intentionally declared non-virtual, so there is no way to
* override it. Instead feel free to override getFlagsImpl(...) instead, and
* enjoy the convenience of defaultFlags passed there.
*
* @param flags Write flags requested for the given write operation
*/
int getFlags(folly::WriteFlags flags, bool zeroCopyEnabled) noexcept {
return getFlagsImpl(flags, getDefaultFlags(flags, zeroCopyEnabled));
}
/**
* getAncillaryData() will be invoked to initialize ancillary data
* buffer referred by "msg_control" field of msghdr structure passed to
* ::sendmsg() system call based on the flags set in the passed
* folly::WriteFlags enum. Some flags in folly::WriteFlags are not relevant
* during this process. The function assumes that the size of buffer
* is not smaller than the value returned by getAncillaryDataSize() method
* for the same combination of flags.
*
* @param flags Write flags requested for the given write operation
* @param data Pointer to ancillary data buffer to initialize.
*/
virtual void getAncillaryData(
folly::WriteFlags /*flags*/,
void* /*data*/) noexcept {}
/**
* getAncillaryDataSize() will be invoked to retrieve the size of
* ancillary data buffer which should be passed to ::sendmsg() system call
*
* @param flags Write flags requested for the given write operation
*/
virtual uint32_t getAncillaryDataSize(
folly::WriteFlags /*flags*/) noexcept {
return 0;
}
static const size_t maxAncillaryDataSize{0x5000};
private:
/**
* getFlagsImpl() will be invoked by getFlags(folly::WriteFlags flags)
* method to retrieve the flags to be passed to ::sendmsg() system call.
* SendMsgParamsCallback::getFlags() is calling this method, and returns
* its results directly to the caller in AsyncSocket.
* Classes inheriting from SendMsgParamsCallback are welcome to override
* this method to force SendMsgParamsCallback to return its own set
* of flags.
*
* @param flags Write flags requested for the given write operation
* @param defaultflags A set of message flags returned by getDefaultFlags()
* method for the given "flags" mask.
*/
virtual int getFlagsImpl(folly::WriteFlags /*flags*/, int defaultFlags) {
return defaultFlags;
}
/**
* getDefaultFlags() will be invoked by getFlags(folly::WriteFlags flags)
* to retrieve the default set of flags, and pass them to getFlagsImpl(...)
*
* @param flags Write flags requested for the given write operation
*/
int getDefaultFlags(folly::WriteFlags flags, bool zeroCopyEnabled) noexcept;
};
explicit AsyncSocket();
/**
* Create a new unconnected AsyncSocket.
*
* connect() must later be called on this socket to establish a connection.
*/
explicit AsyncSocket(EventBase* evb);
void setShutdownSocketSet(const std::weak_ptr<ShutdownSocketSet>& wSS);
/**
* Create a new AsyncSocket and begin the connection process.
*
* @param evb EventBase that will manage this socket.
* @param address The address to connect to.
* @param connectTimeout Optional timeout in milliseconds for the connection
* attempt.
* @param useZeroCopy Optional zerocopy socket mode
*/
AsyncSocket(
EventBase* evb,
const folly::SocketAddress& address,
uint32_t connectTimeout = 0,
bool useZeroCopy = false);
/**
* Create a new AsyncSocket and begin the connection process.
*
* @param evb EventBase that will manage this socket.
* @param ip IP address to connect to (dotted-quad).
* @param port Destination port in host byte order.
* @param connectTimeout Optional timeout in milliseconds for the connection
* attempt.
* @param useZeroCopy Optional zerocopy socket mode
*/
AsyncSocket(
EventBase* evb,
const std::string& ip,
uint16_t port,
uint32_t connectTimeout = 0,
bool useZeroCopy = false);
/**
* Create a AsyncSocket from an already connected socket file descriptor.
*
* Note that while AsyncSocket enables TCP_NODELAY for sockets it creates
* when connecting, it does not change the socket options when given an
* existing file descriptor. If callers want TCP_NODELAY enabled when using
* this version of the constructor, they need to explicitly call
* setNoDelay(true) after the constructor returns.
*
* @param evb EventBase that will manage this socket.
* @param fd File descriptor to take over (should be a connected socket).
* @param zeroCopyBufId Zerocopy buf id to start with.
*/
AsyncSocket(EventBase* evb, NetworkSocket fd, uint32_t zeroCopyBufId = 0);
/**
* Create an AsyncSocket from a different, already connected AsyncSocket.
*
* Similar to AsyncSocket(evb, fd) when fd was previously owned by an
* AsyncSocket.
*/
explicit AsyncSocket(AsyncSocket::UniquePtr);
/**
* Helper function to create a shared_ptr<AsyncSocket>.
*
* This passes in the correct destructor object, since AsyncSocket's
* destructor is protected and cannot be invoked directly.
*/
static std::shared_ptr<AsyncSocket> newSocket(EventBase* evb) {
return std::shared_ptr<AsyncSocket>(new AsyncSocket(evb), Destructor());
}
/**
* Helper function to create a shared_ptr<AsyncSocket>.
*/
static std::shared_ptr<AsyncSocket> newSocket(
EventBase* evb,
const folly::SocketAddress& address,
uint32_t connectTimeout = 0,
bool useZeroCopy = false) {
return std::shared_ptr<AsyncSocket>(
new AsyncSocket(evb, address, connectTimeout, useZeroCopy),
Destructor());
}
/**
* Helper function to create a shared_ptr<AsyncSocket>.
*/
static std::shared_ptr<AsyncSocket> newSocket(
EventBase* evb,
const std::string& ip,
uint16_t port,
uint32_t connectTimeout = 0,
bool useZeroCopy = false) {
return std::shared_ptr<AsyncSocket>(
new AsyncSocket(evb, ip, port, connectTimeout, useZeroCopy),
Destructor());
}
/**
* Helper function to create a shared_ptr<AsyncSocket>.
*/
static std::shared_ptr<AsyncSocket> newSocket(
EventBase* evb,
NetworkSocket fd) {
return std::shared_ptr<AsyncSocket>(new AsyncSocket(evb, fd), Destructor());
}
/**
* Destroy the socket.
*
* AsyncSocket::destroy() must be called to destroy the socket.
* The normal destructor is private, and should not be invoked directly.
* This prevents callers from deleting a AsyncSocket while it is invoking a
* callback.
*/
void destroy() override;
/**
* Get the EventBase used by this socket.
*/
EventBase* getEventBase() const override {
return eventBase_;
}
/**
* Get the network socket used by the AsyncSocket.
*/
virtual NetworkSocket getNetworkSocket() const {
return fd_;
}
/**
* Extract the file descriptor from the AsyncSocket.
*
* This will immediately cause any installed callbacks to be invoked with an
* error. The AsyncSocket may no longer be used after the file descriptor
* has been extracted.
*
* This method should be used with care as the resulting fd is not guaranteed
* to perfectly reflect the state of the AsyncSocket (security state,
* pre-received data, etc.).
*
* Returns the file descriptor. The caller assumes ownership of the
* descriptor, and it will not be closed when the AsyncSocket is destroyed.
*/
virtual NetworkSocket detachNetworkSocket();
static const folly::SocketAddress& anyAddress();
/**
* Initiate a connection.
*
* @param callback The callback to inform when the connection attempt
* completes.
* @param address The address to connect to.
* @param timeout A timeout value, in milliseconds. If the connection
* does not succeed within this period,
* callback->connectError() will be invoked.
*/
virtual void connect(
ConnectCallback* callback,
const folly::SocketAddress& address,
int timeout = 0,
const SocketOptionMap& options = emptySocketOptionMap,
const folly::SocketAddress& bindAddr = anyAddress()) noexcept;
void connect(
ConnectCallback* callback,
const std::string& ip,
uint16_t port,
int timeout = 0,
const SocketOptionMap& options = emptySocketOptionMap) noexcept;
/**
* If a connect request is in-flight, cancels it and closes the socket
* immediately. Otherwise, this is a no-op.
*
* This does not invoke any connection related callbacks. Call this to
* prevent any connect callback while cleaning up, etc.
*/
virtual void cancelConnect();
/**
* Set the send timeout.
*
* If write requests do not make any progress for more than the specified
* number of milliseconds, fail all pending writes and close the socket.
*
* If write requests are currently pending when setSendTimeout() is called,
* the timeout interval is immediately restarted using the new value.
*
* (See the comments for AsyncSocket for an explanation of why AsyncSocket
* provides setSendTimeout() but not setRecvTimeout().)
*
* @param milliseconds The timeout duration, in milliseconds. If 0, no
* timeout will be used.
*/
void setSendTimeout(uint32_t milliseconds) override;
/**
* Get the send timeout.
*
* @return Returns the current send timeout, in milliseconds. A return value
* of 0 indicates that no timeout is set.
*/
uint32_t getSendTimeout() const override {
return sendTimeout_;
}
/**
* Set the maximum number of reads to execute from the underlying
* socket each time the EventBase detects that new ingress data is
* available. The default is unlimited, but callers can use this method
* to limit the amount of data read from the socket per event loop
* iteration.
*
* @param maxReads Maximum number of reads per data-available event;
* a value of zero means unlimited.
*/
void setMaxReadsPerEvent(uint16_t maxReads) {
maxReadsPerEvent_ = maxReads;
}
/**
* Get the maximum number of reads this object will execute from
* the underlying socket each time the EventBase detects that new
* ingress data is available.
*
* @returns Maximum number of reads per data-available event; a value
* of zero means unlimited.
*/
uint16_t getMaxReadsPerEvent() const {
return maxReadsPerEvent_;
}
/**
* Set a pointer to ErrMessageCallback implementation which will be
* receiving notifications for messages posted to the error queue
* associated with the socket.
* ErrMessageCallback is implemented only for platforms with
* per-socket error message queus support (recvmsg() system call must
* )
*
*/
virtual void setErrMessageCB(ErrMessageCallback* callback);
/**
* Get a pointer to ErrMessageCallback implementation currently
* registered with this socket.
*
*/
virtual ErrMessageCallback* getErrMessageCallback() const;
/**
* Set a pointer to SendMsgParamsCallback implementation which
* will be used to form ::sendmsg() system call parameters
*
*/
virtual void setSendMsgParamCB(SendMsgParamsCallback* callback);
/**
* Get a pointer to SendMsgParamsCallback implementation currently
* registered with this socket.
*
*/
virtual SendMsgParamsCallback* getSendMsgParamsCB() const;
// Read and write methods
void setReadCB(ReadCallback* callback) override;
ReadCallback* getReadCallback() const override;
bool setZeroCopy(bool enable) override;
bool getZeroCopy() const override {
return zeroCopyEnabled_;
}
uint32_t getZeroCopyBufId() const {
return zeroCopyBufId_;
}
size_t getZeroCopyReenableThreshold() const {
return zeroCopyReenableThreshold_;
}
void setZeroCopyEnableFunc(AsyncWriter::ZeroCopyEnableFunc func) override;
void setZeroCopyReenableThreshold(size_t threshold);
void write(
WriteCallback* callback,
const void* buf,
size_t bytes,
WriteFlags flags = WriteFlags::NONE) override;
void writev(
WriteCallback* callback,
const iovec* vec,
size_t count,
WriteFlags flags = WriteFlags::NONE) override;
void writeChain(
WriteCallback* callback,
std::unique_ptr<folly::IOBuf>&& buf,
WriteFlags flags = WriteFlags::NONE) override;
class WriteRequest;
virtual void writeRequest(WriteRequest* req);
void writeRequestReady() {
handleWrite();
}
// Methods inherited from AsyncTransport
void close() override;
void closeNow() override;
void closeWithReset() override;
void shutdownWrite() override;
void shutdownWriteNow() override;
bool readable() const override;
bool writable() const override;
bool isPending() const override;
virtual bool hangup() const;
bool good() const override;
bool error() const override;
void attachEventBase(EventBase* eventBase) override;
void detachEventBase() override;
bool isDetachable() const override;
void getLocalAddress(folly::SocketAddress* address) const override;
void getPeerAddress(folly::SocketAddress* address) const override;
bool isEorTrackingEnabled() const override {
return trackEor_;
}
void setEorTracking(bool track) override {
trackEor_ = track;
}
bool connecting() const override {
return (state_ == StateEnum::CONNECTING);
}
virtual bool isClosedByPeer() const {
return (
state_ == StateEnum::CLOSED &&
(readErr_ == READ_EOF || readErr_ == READ_ERROR));
}
virtual bool isClosedBySelf() const {
return (
state_ == StateEnum::CLOSED &&
(readErr_ != READ_EOF && readErr_ != READ_ERROR));
}
size_t getAppBytesWritten() const override {
return appBytesWritten_;
}
size_t getRawBytesWritten() const override {
return getAppBytesWritten();
}
size_t getAppBytesReceived() const override {
return appBytesReceived_;
}
size_t getRawBytesReceived() const override {
return getAppBytesReceived();
}
size_t getAppBytesBuffered() const override {
return totalAppBytesScheduledForWrite_ - appBytesWritten_;
}
size_t getRawBytesBuffered() const override {
return getAppBytesBuffered();
}
std::chrono::nanoseconds getConnectTime() const {
return connectEndTime_ - connectStartTime_;
}
std::chrono::milliseconds getConnectTimeout() const {
return connectTimeout_;
}
std::chrono::steady_clock::time_point getConnectStartTime() const {
return connectStartTime_;
}
std::chrono::steady_clock::time_point getConnectEndTime() const {
return connectEndTime_;
}
bool getTFOAttempted() const {
return tfoAttempted_;
}
/**
* Returns whether or not the attempt to use TFO
* finished successfully. This does not necessarily
* mean TFO worked, just that trying to use TFO
* succeeded.
*/
bool getTFOFinished() const {
return tfoFinished_;
}
/**
* Returns whether or not TFO attempt succeded on this
* connection.
* For servers this is pretty straightforward API and can
* be invoked right after the connection is accepted. This API
* will perform one syscall.
* This API is a bit tricky to use for clients, since clients
* only know this for sure after the SYN-ACK is returned. So it's
* appropriate to call this only after the first application
* data is read from the socket when the caller knows that
* the SYN has been ACKed by the server.
*/
bool getTFOSucceded() const;
// Methods controlling socket options
/**
* Force writes to be transmitted immediately.
*
* This controls the TCP_NODELAY socket option. When enabled, TCP segments
* are sent as soon as possible, even if it is not a full frame of data.
* When disabled, the data may be buffered briefly to try and wait for a full
* frame of data.
*
* By default, TCP_NODELAY is enabled for AsyncSocket objects.
*
* This method will fail if the socket is not currently open.
*
* @return Returns 0 if the TCP_NODELAY flag was successfully updated,
* or a non-zero errno value on error.
*/
int setNoDelay(bool noDelay);
/**
* Set the FD_CLOEXEC flag so that the socket will be closed if the program
* later forks and execs.
*/
void setCloseOnExec();
/*
* Set the Flavor of Congestion Control to be used for this Socket
* Please check '/lib/modules/<kernel>/kernel/net/ipv4' for tcp_*.ko
* first to make sure the module is available for plugging in
* Alternatively you can choose from net.ipv4.tcp_allowed_congestion_control
*/
int setCongestionFlavor(const std::string& cname);
/*
* Forces ACKs to be sent immediately
*
* @return Returns 0 if the TCP_QUICKACK flag was successfully updated,
* or a non-zero errno value on error.
*/
int setQuickAck(bool quickack);
/**
* Set the send bufsize
*/
int setSendBufSize(size_t bufsize);
/**
* Set the recv bufsize
*/
int setRecvBufSize(size_t bufsize);
#if defined(__linux__)
/**
* @brief This method is used to get the number of bytes that are currently
* stored in the TCP send/tx buffer
*
* @return the number of bytes in the send/tx buffer or folly::none if there
* was a problem
*/
size_t getSendBufInUse() const;
/**
* @brief This method is used to get the number of bytes that are currently
* stored in the TCP receive/rx buffer
*
* @return the number of bytes in the receive/rx buffer or folly::none if
* there was a problem
*/
size_t getRecvBufInUse() const;
#endif
/**
* Sets a specific tcp personality
* Available only on kernels 3.2 and greater
*/
#define SO_SET_NAMESPACE 41
int setTCPProfile(int profd);
/**
* Generic API for reading a socket option.
*
* @param level same as the "level" parameter in getsockopt().
* @param optname same as the "optname" parameter in getsockopt().
* @param optval pointer to the variable in which the option value should
* be returned.
* @param optlen value-result argument, initially containing the size of
* the buffer pointed to by optval, and modified on return
* to indicate the actual size of the value returned.
* @return same as the return value of getsockopt().
*/
template <typename T>
int getSockOpt(int level, int optname, T* optval, socklen_t* optlen) {
return netops::getsockopt(fd_, level, optname, (void*)optval, optlen);
}
/**
* Generic API for setting a socket option.
*
* @param level same as the "level" parameter in getsockopt().
* @param optname same as the "optname" parameter in getsockopt().
* @param optval the option value to set.
* @return same as the return value of setsockopt().
*/
template <typename T>
int setSockOpt(int level, int optname, const T* optval) {
return netops::setsockopt(fd_, level, optname, optval, sizeof(T));
}
/**
* Virtual method for reading a socket option returning integer
* value, which is the most typical case. Convenient for overriding
* and mocking.
*
* @param level same as the "level" parameter in getsockopt().
* @param optname same as the "optname" parameter in getsockopt().
* @param optval same as "optval" parameter in getsockopt().
* @param optlen same as "optlen" parameter in getsockopt().
* @return same as the return value of getsockopt().
*/
virtual int
getSockOptVirtual(int level, int optname, void* optval, socklen_t* optlen) {
return netops::getsockopt(fd_, level, optname, optval, optlen);
}
/**
* Virtual method for setting a socket option accepting integer
* value, which is the most typical case. Convenient for overriding
* and mocking.
*
* @param level same as the "level" parameter in setsockopt().
* @param optname same as the "optname" parameter in setsockopt().
* @param optval same as "optval" parameter in setsockopt().
* @param optlen same as "optlen" parameter in setsockopt().
* @return same as the return value of setsockopt().
*/
virtual int setSockOptVirtual(
int level,
int optname,
void const* optval,
socklen_t optlen) {
return netops::setsockopt(fd_, level, optname, optval, optlen);
}
/**
* Set pre-received data, to be returned to read callback before any data
* from the socket.
*/
virtual void setPreReceivedData(std::unique_ptr<IOBuf> data) {
if (preReceivedData_) {
preReceivedData_->prependChain(std::move(data));
} else {
preReceivedData_ = std::move(data);
}
}
/**
* Enables TFO behavior on the AsyncSocket if FOLLY_ALLOW_TFO
* is set.
*/
void enableTFO() {
// No-op if folly does not allow tfo
#if FOLLY_ALLOW_TFO
tfoEnabled_ = true;
#endif
}
void disableTransparentTls() {
noTransparentTls_ = true;
}
void disableTSocks() {
noTSocks_ = true;
}
enum class StateEnum : uint8_t {
UNINIT,
CONNECTING,
ESTABLISHED,
CLOSED,
ERROR,
FAST_OPEN,
};
void setBufferCallback(BufferCallback* cb);
// Callers should set this prior to connecting the socket for the safest
// behavior.
void setEvbChangedCallback(std::unique_ptr<EvbChangeCallback> cb) {
evbChangeCb_ = std::move(cb);
}
/**
* Attempt to cache the current local and peer addresses (if not already
* cached) so that they are available from getPeerAddress() and
* getLocalAddress() even after the socket is closed.
*/
void cacheAddresses();
/**
* Returns true if there is any zero copy write in progress
* Needs to be called from within the socket's EVB thread
*/
bool isZeroCopyWriteInProgress() const noexcept;
/**
* Tries to process the msg error queue
* And returns true if there are no more zero copy writes in progress
*/
bool processZeroCopyWriteInProgress() noexcept;
void setPeerCertificate(
std::unique_ptr<const AsyncTransportCertificate> cert) {
peerCertData_ = std::move(cert);
}
const AsyncTransportCertificate* getPeerCertificate() const override {
return peerCertData_.get();
}
void setSelfCertificate(
std::unique_ptr<const AsyncTransportCertificate> cert) {
selfCertData_ = std::move(cert);
}
const AsyncTransportCertificate* getSelfCertificate() const override {
return selfCertData_.get();
}
/**
* Whether socket should be closed on write failure (true by default).
*/
void setCloseOnFailedWrite(bool closeOnFailedWrite) {
closeOnFailedWrite_ = closeOnFailedWrite;
}
/**
* writeReturn is the total number of bytes written, or WRITE_ERROR on error.
* If no data has been written, 0 is returned.
* exception is a more specific exception that cause a write error.
* Not all writes have exceptions associated with them thus writeReturn
* should be checked to determine whether the operation resulted in an error.
*/
struct WriteResult {
explicit WriteResult(ssize_t ret) : writeReturn(ret) {}
WriteResult(ssize_t ret, std::unique_ptr<const AsyncSocketException> e)
: writeReturn(ret), exception(std::move(e)) {}
ssize_t writeReturn;
std::unique_ptr<const AsyncSocketException> exception;
};
/**
* readReturn is the number of bytes read, or READ_EOF on EOF, or
* READ_ERROR on error, or READ_BLOCKING if the operation will
* block.
* exception is a more specific exception that may have caused a read error.
* Not all read errors have exceptions associated with them thus readReturn
* should be checked to determine whether the operation resulted in an error.
*/
struct ReadResult {
explicit ReadResult(ssize_t ret) : readReturn(ret) {}
ReadResult(ssize_t ret, std::unique_ptr<const AsyncSocketException> e)
: readReturn(ret), exception(std::move(e)) {}
ssize_t readReturn;
std::unique_ptr<const AsyncSocketException> exception;
};
/**
* A WriteRequest object tracks information about a pending write operation.
*/
class WriteRequest {
public:
WriteRequest(AsyncSocket* socket, WriteCallback* callback)
: socket_(socket), callback_(callback) {}
virtual void start() {}
virtual void destroy() = 0;
virtual WriteResult performWrite() = 0;
virtual void consume() = 0;
virtual bool isComplete() = 0;
WriteRequest* getNext() const {
return next_;
}
WriteCallback* getCallback() const {
return callback_;
}
uint32_t getTotalBytesWritten() const {
return totalBytesWritten_;
}
void append(WriteRequest* next) {
assert(next_ == nullptr);
next_ = next;
}
void fail(const char* fn, const AsyncSocketException& ex) {
socket_->failWrite(fn, ex);
}
void bytesWritten(size_t count) {
totalBytesWritten_ += uint32_t(count);
socket_->appBytesWritten_ += count;
}
protected:
// protected destructor, to ensure callers use destroy()
virtual ~WriteRequest() {}
AsyncSocket* socket_; ///< parent socket
WriteRequest* next_{nullptr}; ///< pointer to next WriteRequest
WriteCallback* callback_; ///< completion callback
uint32_t totalBytesWritten_{0}; ///< total bytes written
};
protected:
enum ReadResultEnum {
READ_EOF = 0,
READ_ERROR = -1,
READ_BLOCKING = -2,
READ_NO_ERROR = -3,
};
enum WriteResultEnum {
WRITE_ERROR = -1,
};
/**
* Protected destructor.
*
* Users of AsyncSocket must never delete it directly. Instead, invoke
* destroy() instead. (See the documentation in DelayedDestruction.h for
* more details.)
*/
~AsyncSocket() override;
friend std::ostream& operator<<(std::ostream& os, const StateEnum& state);
enum ShutdownFlags {
/// shutdownWrite() called, but we are still waiting on writes to drain
SHUT_WRITE_PENDING = 0x01,
/// writes have been completely shut down
SHUT_WRITE = 0x02,
/**
* Reads have been shutdown.
*
* At the moment we don't distinguish between remote read shutdown
* (received EOF from the remote end) and local read shutdown. We can
* only receive EOF when a read callback is set, and we immediately inform
* it of the EOF. Therefore there doesn't seem to be any reason to have a
* separate state of "received EOF but the local side may still want to
* read".
*
* We also don't currently provide any API for only shutting down the read
* side of a socket. (This is a no-op as far as TCP is concerned, anyway.)
*/
SHUT_READ = 0x04,
};
class BytesWriteRequest;
class WriteTimeout : public AsyncTimeout {
public:
WriteTimeout(AsyncSocket* socket, EventBase* eventBase)
: AsyncTimeout(eventBase), socket_(socket) {}
void timeoutExpired() noexcept override {
socket_->timeoutExpired();
}
private:
AsyncSocket* socket_;
};
class IoHandler : public EventHandler {
public:
IoHandler(AsyncSocket* socket, EventBase* eventBase)
: EventHandler(eventBase, NetworkSocket()), socket_(socket) {}
IoHandler(AsyncSocket* socket, EventBase* eventBase, NetworkSocket fd)
: EventHandler(eventBase, fd), socket_(socket) {}
void handlerReady(uint16_t events) noexcept override {
socket_->ioReady(events);
}
private:
AsyncSocket* socket_;
};
void init();
class ImmediateReadCB : public folly::EventBase::LoopCallback {
public:
explicit ImmediateReadCB(AsyncSocket* socket) : socket_(socket) {}
void runLoopCallback() noexcept override {
DestructorGuard dg(socket_);
socket_->checkForImmediateRead();
}
private:
AsyncSocket* socket_;
};
/**
* Schedule checkForImmediateRead to be executed in the next loop
* iteration.
*/
void scheduleImmediateRead() noexcept {
if (good()) {
eventBase_->runInLoop(&immediateReadHandler_);
}
}
/**
* Schedule handleInitalReadWrite to run in the next iteration.
*/
void scheduleInitialReadWrite() noexcept {
if (good()) {
DestructorGuard dg(this);
eventBase_->runInLoop([this, dg] {
if (good()) {
handleInitialReadWrite();
}
});
}
}
// event notification methods
void ioReady(uint16_t events) noexcept;
virtual void checkForImmediateRead() noexcept;
virtual void handleInitialReadWrite() noexcept;
virtual void prepareReadBuffer(void** buf, size_t* buflen);
virtual size_t handleErrMessages() noexcept;
virtual void handleRead() noexcept;
virtual void handleWrite() noexcept;
virtual void handleConnect() noexcept;
void timeoutExpired() noexcept;
/**
* Attempt to read from the socket.
*
* @param buf The buffer to read data into.
* @param buflen The length of the buffer.
*
* @return Returns a read result. See read result for details.
*/
virtual ReadResult performRead(void** buf, size_t* buflen, size_t* offset);
/**
* Populate an iovec array from an IOBuf and attempt to write it.
*
* @param callback Write completion/error callback.
* @param vec Target iovec array; caller retains ownership.
* @param count Number of IOBufs to write, beginning at start of buf.
* @param buf Chain of iovecs.
* @param flags set of flags for the underlying write calls, like cork
*/
void writeChainImpl(
WriteCallback* callback,
iovec* vec,
size_t count,
std::unique_ptr<folly::IOBuf>&& buf,
WriteFlags flags);
/**
* Write as much data as possible to the socket without blocking,
* and queue up any leftover data to send when the socket can
* handle writes again.
*
* @param callback The callback to invoke when the write is completed.
* @param vec Array of buffers to write; this method will make a
* copy of the vector (but not the buffers themselves)
* if the write has to be completed asynchronously.
* @param count Number of elements in vec.
* @param buf The IOBuf that manages the buffers referenced by
* vec, or a pointer to nullptr if the buffers are not
* associated with an IOBuf. Note that ownership of
* the IOBuf is transferred here; upon completion of
* the write, the AsyncSocket deletes the IOBuf.
* @param totalBytes The total number of bytes to be written.
* @param flags Set of write flags.
*/
void writeImpl(
WriteCallback* callback,
const iovec* vec,
size_t count,
std::unique_ptr<folly::IOBuf>&& buf,
size_t totalBytes,
WriteFlags flags = WriteFlags::NONE);
/**
* Attempt to write to the socket.
*
* @param vec The iovec array pointing to the buffers to write.
* @param count The length of the iovec array.
* @param flags Set of write flags.
* @param countWritten On return, the value pointed to by this parameter
* will contain the number of iovec entries that were
* fully written.
* @param partialWritten On return, the value pointed to by this parameter
* will contain the number of bytes written in the
* partially written iovec entry.
*
* @return Returns a WriteResult. See WriteResult for more details.
*/
virtual WriteResult performWrite(
const iovec* vec,
uint32_t count,
WriteFlags flags,
uint32_t* countWritten,
uint32_t* partialWritten);
/**
* Sends the message over the socket using sendmsg
*
* @param msg Message to send
* @param msg_flags Flags to pass to sendmsg
*/
AsyncSocket::WriteResult
sendSocketMessage(NetworkSocket fd, struct msghdr* msg, int msg_flags);
virtual ssize_t
tfoSendMsg(NetworkSocket fd, struct msghdr* msg, int msg_flags);
int socketConnect(const struct sockaddr* addr, socklen_t len);
virtual void scheduleConnectTimeout();
void registerForConnectEvents();
bool updateEventRegistration();
/**
* Update event registration.
*
* @param enable Flags of events to enable. Set it to 0 if no events
* need to be enabled in this call.
* @param disable Flags of events
* to disable. Set it to 0 if no events need to be disabled in this
* call.
*
* @return true iff the update is successful.
*/
bool updateEventRegistration(uint16_t enable, uint16_t disable);
// Actually close the file descriptor and set it to -1 so we don't
// accidentally close it again.
void doClose();
// error handling methods
void startFail();
void finishFail();
void finishFail(const AsyncSocketException& ex);
void invokeAllErrors(const AsyncSocketException& ex);
void fail(const char* fn, const AsyncSocketException& ex);
void failConnect(const char* fn, const AsyncSocketException& ex);
void failRead(const char* fn, const AsyncSocketException& ex);
void failErrMessageRead(const char* fn, const AsyncSocketException& ex);
void failWrite(
const char* fn,
WriteCallback* callback,
size_t bytesWritten,
const AsyncSocketException& ex);
void failWrite(const char* fn, const AsyncSocketException& ex);
void failAllWrites(const AsyncSocketException& ex);
virtual void invokeConnectErr(const AsyncSocketException& ex);
virtual void invokeConnectSuccess();
void invalidState(ConnectCallback* callback);
void invalidState(ErrMessageCallback* callback);
void invalidState(ReadCallback* callback);
void invalidState(WriteCallback* callback);
std::string withAddr(folly::StringPiece s);
void cacheLocalAddress() const;
void cachePeerAddress() const;
void applyOptions(
const SocketOptionMap& options,
SocketOptionKey::ApplyPos pos);
bool isZeroCopyRequest(WriteFlags flags);
bool isZeroCopyMsg(const cmsghdr& cmsg) const;
void processZeroCopyMsg(const cmsghdr& cmsg);
uint32_t getNextZeroCopyBufId() {
return zeroCopyBufId_++;
}
void adjustZeroCopyFlags(folly::WriteFlags& flags);
void addZeroCopyBuf(std::unique_ptr<folly::IOBuf>&& buf);
void addZeroCopyBuf(folly::IOBuf* ptr);
void setZeroCopyBuf(std::unique_ptr<folly::IOBuf>&& buf);
bool containsZeroCopyBuf(folly::IOBuf* ptr);
void releaseZeroCopyBuf(uint32_t id);
AsyncWriter::ZeroCopyEnableFunc zeroCopyEnableFunc_;
// a folly::IOBuf can be used in multiple partial requests
// there is a that maps a buffer id to a raw folly::IOBuf ptr
// and another one that adds a ref count for a folly::IOBuf that is either
// the original ptr or nullptr
uint32_t zeroCopyBufId_{0};
struct IOBufInfo {
uint32_t count_{0};
std::unique_ptr<folly::IOBuf> buf_;
};
std::unordered_map<uint32_t, folly::IOBuf*> idZeroCopyBufPtrMap_;
std::unordered_map<folly::IOBuf*, IOBufInfo> idZeroCopyBufInfoMap_;
StateEnum state_; ///< StateEnum describing current state
uint8_t shutdownFlags_; ///< Shutdown state (ShutdownFlags)
uint16_t eventFlags_; ///< EventBase::HandlerFlags settings
NetworkSocket fd_; ///< The socket file descriptor
mutable folly::SocketAddress addr_; ///< The address we tried to connect to
mutable folly::SocketAddress localAddr_;
///< The address we are connecting from
uint32_t sendTimeout_; ///< The send timeout, in milliseconds
uint16_t maxReadsPerEvent_; ///< Max reads per event loop iteration
int8_t readErr_{READ_NO_ERROR}; ///< The read error encountered, if any
EventBase* eventBase_; ///< The EventBase
WriteTimeout writeTimeout_; ///< A timeout for connect and write
IoHandler ioHandler_; ///< A EventHandler to monitor the fd
ImmediateReadCB immediateReadHandler_; ///< LoopCallback for checking read
ConnectCallback* connectCallback_; ///< ConnectCallback
ErrMessageCallback* errMessageCallback_; ///< TimestampCallback
SendMsgParamsCallback* ///< Callback for retrieving
sendMsgParamCallback_; ///< ::sendmsg() parameters
ReadCallback* readCallback_; ///< ReadCallback
WriteRequest* writeReqHead_; ///< Chain of WriteRequests
WriteRequest* writeReqTail_; ///< End of WriteRequest chain
std::weak_ptr<ShutdownSocketSet> wShutdownSocketSet_;
size_t appBytesReceived_; ///< Num of bytes received from socket
size_t appBytesWritten_; ///< Num of bytes written to socket
// The total num of bytes passed to AsyncSocket's write functions. It doesn't
// include failed writes, but it does include buffered writes.
size_t totalAppBytesScheduledForWrite_;
// Pre-received data, to be returned to read callback before any data from the
// socket.
std::unique_ptr<IOBuf> preReceivedData_;
std::chrono::steady_clock::time_point connectStartTime_;
std::chrono::steady_clock::time_point connectEndTime_;
std::chrono::milliseconds connectTimeout_{0};
std::unique_ptr<EvbChangeCallback> evbChangeCb_{nullptr};
BufferCallback* bufferCallback_{nullptr};
bool tfoEnabled_{false};
bool tfoAttempted_{false};
bool tfoFinished_{false};
bool noTransparentTls_{false};
bool noTSocks_{false};
// Whether to track EOR or not.
bool trackEor_{false};
bool zeroCopyEnabled_{false};
bool zeroCopyVal_{false};
// zerocopy re-enable logic
size_t zeroCopyReenableThreshold_{0};
size_t zeroCopyReenableCounter_{0};
// subclasses may cache these on first call to get
mutable std::unique_ptr<const AsyncTransportCertificate> peerCertData_{
nullptr};
mutable std::unique_ptr<const AsyncTransportCertificate> selfCertData_{
nullptr};
bool closeOnFailedWrite_{true};
};
#ifdef _MSC_VER
#pragma vtordisp(pop)
#endif
} // namespace folly