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gfiber / vendor / google / platform / 2306e158f30f5cf68f216fcaa1c287eec08a0a9f / . / base / physicalsocketserver.cc
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/*
* libjingle
* Copyright 2004--2005, Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#if defined(_MSC_VER) && _MSC_VER < 1300
#pragma warning(disable:4786)
#endif
#include <cassert>
#ifdef POSIX
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/time.h>
#include <unistd.h>
#include <signal.h>
#endif
#ifdef WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#undef SetPort
#endif
#include <algorithm>
#include <map>
#include "bruno/basictypes.h"
#include "bruno/byteorder.h"
#include "bruno/common.h"
#include "bruno/logging.h"
#include "bruno/nethelpers.h"
#include "bruno/physicalsocketserver.h"
#include "bruno/time.h"
#ifdef WIN32
#include "winping.h"
#include "win32socketinit.h"
#endif
// stm: this will tell us if we are on OSX
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef POSIX
#include <netinet/tcp.h> // for TCP_NODELAY
#define IP_MTU 14 // Until this is integrated from linux/in.h to netinet/in.h
typedef void* SockOptArg;
#endif // POSIX
#ifdef WIN32
typedef char* SockOptArg;
#endif
namespace bruno_base {
// Standard MTUs, from RFC 1191
const uint16 PACKET_MAXIMUMS[] = {
65535, // Theoretical maximum, Hyperchannel
32000, // Nothing
17914, // 16Mb IBM Token Ring
8166, // IEEE 802.4
//4464, // IEEE 802.5 (4Mb max)
4352, // FDDI
//2048, // Wideband Network
2002, // IEEE 802.5 (4Mb recommended)
//1536, // Expermental Ethernet Networks
//1500, // Ethernet, Point-to-Point (default)
1492, // IEEE 802.3
1006, // SLIP, ARPANET
//576, // X.25 Networks
//544, // DEC IP Portal
//512, // NETBIOS
508, // IEEE 802/Source-Rt Bridge, ARCNET
296, // Point-to-Point (low delay)
68, // Official minimum
0, // End of list marker
};
const uint32 IP_HEADER_SIZE = 20;
const uint32 ICMP_HEADER_SIZE = 8;
class PhysicalSocket : public AsyncSocket, public sigslot::has_slots<> {
public:
PhysicalSocket(PhysicalSocketServer* ss, SOCKET s = INVALID_SOCKET)
: ss_(ss), s_(s), enabled_events_(0), error_(0),
state_((s == INVALID_SOCKET) ? CS_CLOSED : CS_CONNECTED),
resolver_(NULL) {
#ifdef WIN32
// EnsureWinsockInit() ensures that winsock is initialized. The default
// version of this function doesn't do anything because winsock is
// initialized by constructor of a static object. If neccessary libjingle
// users can link it with a different version of this function by replacing
// win32socketinit.cc. See win32socketinit.cc for more details.
EnsureWinsockInit();
#endif
if (s_ != INVALID_SOCKET) {
enabled_events_ = DE_READ | DE_WRITE;
int type = SOCK_STREAM;
socklen_t len = sizeof(type);
VERIFY(0 == getsockopt(s_, SOL_SOCKET, SO_TYPE, (SockOptArg)&type, &len));
udp_ = (SOCK_DGRAM == type);
}
}
virtual ~PhysicalSocket() {
Close();
}
// Creates the underlying OS socket (same as the "socket" function).
virtual bool Create(int type) {
Close();
s_ = ::socket(AF_INET, type, 0);
udp_ = (SOCK_DGRAM == type);
UpdateLastError();
if (udp_)
enabled_events_ = DE_READ | DE_WRITE;
return s_ != INVALID_SOCKET;
}
SocketAddress GetLocalAddress() const {
sockaddr_in addr;
socklen_t addrlen = sizeof(addr);
int result = ::getsockname(s_, (sockaddr*)&addr, &addrlen);
SocketAddress address;
if (result >= 0) {
ASSERT(addrlen == sizeof(addr));
address.FromSockAddr(addr);
} else {
LOG(LS_WARNING) << "GetLocalAddress: unable to get local addr, socket="
<< s_;
}
return address;
}
SocketAddress GetRemoteAddress() const {
sockaddr_in addr;
socklen_t addrlen = sizeof(addr);
int result = ::getpeername(s_, (sockaddr*)&addr, &addrlen);
SocketAddress address;
if (result >= 0) {
ASSERT(addrlen == sizeof(addr));
address.FromSockAddr(addr);
} else {
LOG(LS_WARNING) << "GetRemoteAddress: unable to get remote addr, socket="
<< s_;
}
return address;
}
int Bind(const SocketAddress& addr) {
sockaddr_in saddr;
addr.ToSockAddr(&saddr);
int err = ::bind(s_, (sockaddr*)&saddr, sizeof(saddr));
UpdateLastError();
#ifdef _DEBUG
if (0 == err) {
dbg_addr_ = "Bound @ ";
dbg_addr_.append(GetLocalAddress().ToString());
}
#endif // _DEBUG
return err;
}
int Connect(const SocketAddress& addr) {
// TODO: Implicit creation is required to reconnect...
// ...but should we make it more explicit?
if ((s_ == INVALID_SOCKET) && !Create(SOCK_STREAM))
return SOCKET_ERROR;
if (addr.IsUnresolved()) {
if (state_ != CS_CLOSED) {
SetError(EALREADY);
return SOCKET_ERROR;
}
LOG(LS_VERBOSE) << "Resolving addr in PhysicalSocket::Connect";
resolver_ = new AsyncResolver();
resolver_->set_address(addr);
resolver_->SignalWorkDone.connect(this, &PhysicalSocket::OnResolveResult);
resolver_->Start();
state_ = CS_CONNECTING;
return 0;
}
return DoConnect(addr);
}
int DoConnect(const SocketAddress& addr) {
sockaddr_in saddr;
addr.ToSockAddr(&saddr);
int err = ::connect(s_, (sockaddr*)&saddr, sizeof(saddr));
UpdateLastError();
if (err == 0) {
state_ = CS_CONNECTED;
} else if (IsBlockingError(error_)) {
state_ = CS_CONNECTING;
enabled_events_ |= DE_CONNECT;
} else {
return SOCKET_ERROR;
}
enabled_events_ |= DE_READ | DE_WRITE;
return 0;
}
int GetError() const {
return error_;
}
void SetError(int error) {
error_ = error;
}
ConnState GetState() const {
return state_;
}
int GetOption(Option opt, int* value) {
int slevel;
int sopt;
if (TranslateOption(opt, &slevel, &sopt) == -1)
return -1;
socklen_t optlen = sizeof(*value);
int ret = ::getsockopt(s_, slevel, sopt, (SockOptArg)value, &optlen);
if (ret != -1 && opt == OPT_DONTFRAGMENT) {
#ifdef LINUX
*value = (*value != IP_PMTUDISC_DONT) ? 1 : 0;
#endif
}
return ret;
}
int SetOption(Option opt, int value) {
int slevel;
int sopt;
if (TranslateOption(opt, &slevel, &sopt) == -1)
return -1;
if (opt == OPT_DONTFRAGMENT) {
#ifdef LINUX
value = (value) ? IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
#endif
}
return ::setsockopt(s_, slevel, sopt, (SockOptArg)&value, sizeof(value));
}
int Send(const void *pv, size_t cb) {
int sent = ::send(s_, reinterpret_cast<const char *>(pv), (int)cb,
#ifdef LINUX
// Suppress SIGPIPE. Without this, attempting to send on a socket whose
// other end is closed will result in a SIGPIPE signal being raised to
// our process, which by default will terminate the process, which we
// don't want. By specifying this flag, we'll just get the error EPIPE
// instead and can handle the error gracefully.
MSG_NOSIGNAL
#else
0
#endif
);
UpdateLastError();
// We have seen minidumps where this may be false.
ASSERT(sent <= static_cast<int>(cb));
if ((sent < 0) && IsBlockingError(error_)) {
enabled_events_ |= DE_WRITE;
}
return sent;
}
int SendTo(const void *pv, size_t cb, const SocketAddress& addr) {
sockaddr_in saddr;
addr.ToSockAddr(&saddr);
int sent = ::sendto(
s_, (const char *)pv, (int)cb,
#ifdef LINUX
// Suppress SIGPIPE. See above for explanation.
MSG_NOSIGNAL,
#else
0,
#endif
(sockaddr*)&saddr, sizeof(saddr));
UpdateLastError();
// We have seen minidumps where this may be false.
ASSERT(sent <= static_cast<int>(cb));
if ((sent < 0) && IsBlockingError(error_)) {
enabled_events_ |= DE_WRITE;
}
return sent;
}
int Recv(void *pv, size_t cb) {
int received = ::recv(s_, (char *)pv, (int)cb, 0);
if ((received == 0) && (cb != 0)) {
// Note: on graceful shutdown, recv can return 0. In this case, we
// pretend it is blocking, and then signal close, so that simplifying
// assumptions can be made about Recv.
LOG(LS_WARNING) << "EOF from socket; deferring close event";
// Must turn this back on so that the select() loop will notice the close
// event.
enabled_events_ |= DE_READ;
error_ = EWOULDBLOCK;
return SOCKET_ERROR;
}
UpdateLastError();
bool success = (received >= 0) || IsBlockingError(error_);
if (udp_ || success) {
enabled_events_ |= DE_READ;
}
if (!success) {
LOG_F(LS_VERBOSE) << "Error = " << error_;
}
return received;
}
int RecvFrom(void *pv, size_t cb, SocketAddress *paddr) {
sockaddr_in saddr;
socklen_t cbAddr = sizeof(saddr);
int received = ::recvfrom(s_, (char *)pv, (int)cb, 0, (sockaddr*)&saddr,
&cbAddr);
UpdateLastError();
if ((received >= 0) && (paddr != NULL))
paddr->FromSockAddr(saddr);
bool success = (received >= 0) || IsBlockingError(error_);
if (udp_ || success) {
enabled_events_ |= DE_READ;
}
if (!success) {
LOG_F(LS_VERBOSE) << "Error = " << error_;
}
return received;
}
int Listen(int backlog) {
int err = ::listen(s_, backlog);
UpdateLastError();
if (err == 0) {
state_ = CS_CONNECTING;
enabled_events_ |= DE_ACCEPT;
#ifdef _DEBUG
dbg_addr_ = "Listening @ ";
dbg_addr_.append(GetLocalAddress().ToString());
#endif // _DEBUG
}
return err;
}
AsyncSocket* Accept(SocketAddress *paddr) {
sockaddr_in saddr;
socklen_t cbAddr = sizeof(saddr);
SOCKET s = ::accept(s_, (sockaddr*)&saddr, &cbAddr);
UpdateLastError();
if (s == INVALID_SOCKET)
return NULL;
enabled_events_ |= DE_ACCEPT;
if (paddr != NULL)
paddr->FromSockAddr(saddr);
return ss_->WrapSocket(s);
}
int Close() {
if (s_ == INVALID_SOCKET)
return 0;
int err = ::closesocket(s_);
UpdateLastError();
s_ = INVALID_SOCKET;
state_ = CS_CLOSED;
enabled_events_ = 0;
if (resolver_) {
resolver_->Destroy(false);
resolver_ = NULL;
}
return err;
}
int EstimateMTU(uint16* mtu) {
SocketAddress addr = GetRemoteAddress();
if (addr.IsAny()) {
error_ = ENOTCONN;
return -1;
}
#if defined(WIN32)
// Gets the interface MTU (TTL=1) for the interface used to reach |addr|.
WinPing ping;
if (!ping.IsValid()) {
error_ = EINVAL; // can't think of a better error ID
return -1;
}
for (int level = 0; PACKET_MAXIMUMS[level + 1] > 0; ++level) {
int32 size = PACKET_MAXIMUMS[level] - IP_HEADER_SIZE - ICMP_HEADER_SIZE;
WinPing::PingResult result = ping.Ping(addr.ip(), size, 0, 1, false);
if (result == WinPing::PING_FAIL) {
error_ = EINVAL; // can't think of a better error ID
return -1;
} else if (result != WinPing::PING_TOO_LARGE) {
*mtu = PACKET_MAXIMUMS[level];
return 0;
}
}
ASSERT(false);
return -1;
#elif defined(IOS) || defined(OSX)
// No simple way to do this on Mac OS X.
// SIOCGIFMTU would work if we knew which interface would be used, but
// figuring that out is pretty complicated. For now we'll return an error
// and let the caller pick a default MTU.
error_ = EINVAL;
return -1;
#elif defined(LINUX) || defined(ANDROID)
// Gets the path MTU.
int value;
socklen_t vlen = sizeof(value);
int err = getsockopt(s_, IPPROTO_IP, IP_MTU, &value, &vlen);
if (err < 0) {
UpdateLastError();
return err;
}
ASSERT((0 <= value) && (value <= 65536));
*mtu = value;
return 0;
#endif
}
SocketServer* socketserver() { return ss_; }
protected:
void OnResolveResult(SignalThread* thread) {
if (thread != resolver_) {
return;
}
int error = resolver_->error();
if (error == 0) {
error = DoConnect(resolver_->address());
} else {
Close();
}
if (error) {
error_ = error;
SignalCloseEvent(this, error_);
}
}
void UpdateLastError() {
error_ = LAST_SYSTEM_ERROR;
}
static int TranslateOption(Option opt, int* slevel, int* sopt) {
switch (opt) {
case OPT_DONTFRAGMENT:
#ifdef WIN32
*slevel = IPPROTO_IP;
*sopt = IP_DONTFRAGMENT;
break;
#elif defined(IOS) || defined(OSX) || defined(BSD)
LOG(LS_WARNING) << "Socket::OPT_DONTFRAGMENT not supported.";
return -1;
#elif defined(POSIX)
*slevel = IPPROTO_IP;
*sopt = IP_MTU_DISCOVER;
break;
#endif
case OPT_RCVBUF:
*slevel = SOL_SOCKET;
*sopt = SO_RCVBUF;
break;
case OPT_SNDBUF:
*slevel = SOL_SOCKET;
*sopt = SO_SNDBUF;
break;
case OPT_NODELAY:
*slevel = IPPROTO_TCP;
*sopt = TCP_NODELAY;
break;
default:
ASSERT(false);
return -1;
}
return 0;
}
PhysicalSocketServer* ss_;
SOCKET s_;
uint8 enabled_events_;
bool udp_;
int error_;
ConnState state_;
AsyncResolver* resolver_;
#ifdef _DEBUG
std::string dbg_addr_;
#endif // _DEBUG;
};
#ifdef POSIX
class EventDispatcher : public Dispatcher {
public:
EventDispatcher(PhysicalSocketServer* ss) : ss_(ss), fSignaled_(false) {
if (pipe(afd_) < 0)
LOG(LERROR) << "pipe failed";
ss_->Add(this);
}
virtual ~EventDispatcher() {
ss_->Remove(this);
close(afd_[0]);
close(afd_[1]);
}
virtual void Signal() {
CritScope cs(&crit_);
if (!fSignaled_) {
const uint8 b[1] = { 0 };
if (VERIFY(1 == write(afd_[1], b, sizeof(b)))) {
fSignaled_ = true;
}
}
}
virtual uint32 GetRequestedEvents() {
return DE_READ;
}
virtual void OnPreEvent(uint32 ff) {
// It is not possible to perfectly emulate an auto-resetting event with
// pipes. This simulates it by resetting before the event is handled.
CritScope cs(&crit_);
if (fSignaled_) {
uint8 b[4]; // Allow for reading more than 1 byte, but expect 1.
VERIFY(1 == read(afd_[0], b, sizeof(b)));
fSignaled_ = false;
}
}
virtual void OnEvent(uint32 ff, int err) {
ASSERT(false);
}
virtual int GetDescriptor() {
return afd_[0];
}
virtual bool IsDescriptorClosed() {
return false;
}
private:
PhysicalSocketServer *ss_;
int afd_[2];
bool fSignaled_;
CriticalSection crit_;
};
// These two classes use the self-pipe trick to deliver POSIX signals to our
// select loop. This is the only safe, reliable, cross-platform way to do
// non-trivial things with a POSIX signal in an event-driven program (until
// proper pselect() implementations become ubiquitous).
class PosixSignalHandler {
public:
// POSIX only specifies 32 signals, but in principle the system might have
// more and the programmer might choose to use them, so we size our array
// for 128.
static const int kNumPosixSignals = 128;
static PosixSignalHandler *Instance() { return &instance_; }
// Returns true if the given signal number is set.
bool IsSignalSet(int signum) const {
ASSERT(signum < ARRAY_SIZE(received_signal_));
if (signum < ARRAY_SIZE(received_signal_)) {
return received_signal_[signum];
} else {
return false;
}
}
// Clears the given signal number.
void ClearSignal(int signum) {
ASSERT(signum < ARRAY_SIZE(received_signal_));
if (signum < ARRAY_SIZE(received_signal_)) {
received_signal_[signum] = false;
}
}
// Returns the file descriptor to monitor for signal events.
int GetDescriptor() const {
return afd_[0];
}
// This is called directly from our real signal handler, so it must be
// signal-handler-safe. That means it cannot assume anything about the
// user-level state of the process, since the handler could be executed at any
// time on any thread.
void OnPosixSignalReceived(int signum) {
if (signum >= ARRAY_SIZE(received_signal_)) {
// We don't have space in our array for this.
return;
}
// Set a flag saying we've seen this signal.
received_signal_[signum] = true;
// Notify application code that we got a signal.
const uint8 b[1] = { 0 };
if (-1 == write(afd_[1], b, sizeof(b))) {
// Nothing we can do here. If there's an error somehow then there's
// nothing we can safely do from a signal handler.
// No, we can't even safely log it.
// But, we still have to check the return value here. Otherwise,
// GCC 4.4.1 complains ignoring return value. Even (void) doesn't help.
return;
}
}
private:
PosixSignalHandler() {
if (pipe(afd_) < 0) {
LOG_ERR(LS_ERROR) << "pipe failed";
return;
}
if (fcntl(afd_[0], F_SETFL, O_NONBLOCK) < 0) {
LOG_ERR(LS_WARNING) << "fcntl #1 failed";
}
if (fcntl(afd_[1], F_SETFL, O_NONBLOCK) < 0) {
LOG_ERR(LS_WARNING) << "fcntl #2 failed";
}
memset(const_cast<void *>(static_cast<volatile void *>(received_signal_)),
0,
sizeof(received_signal_));
}
~PosixSignalHandler() {
int fd1 = afd_[0];
int fd2 = afd_[1];
// We clobber the stored file descriptor numbers here or else in principle
// a signal that happens to be delivered during application termination
// could erroneously write a zero byte to an unrelated file handle in
// OnPosixSignalReceived() if some other file happens to be opened later
// during shutdown and happens to be given the same file descriptor number
// as our pipe had. Unfortunately even with this precaution there is still a
// race where that could occur if said signal happens to be handled
// concurrently with this code and happens to have already read the value of
// afd_[1] from memory before we clobber it, but that's unlikely.
afd_[0] = -1;
afd_[1] = -1;
close(fd1);
close(fd2);
}
// There is just a single global instance. (Signal handlers do not get any
// sort of user-defined void * parameter, so they can't access anything that
// isn't global.)
static PosixSignalHandler instance_;
int afd_[2];
// These are boolean flags that will be set in our signal handler and read
// and cleared from Wait(). There is a race involved in this, but it is
// benign. The signal handler sets the flag before signaling the pipe, so
// we'll never end up blocking in select() while a flag is still true.
// However, if two of the same signal arrive close to each other then it's
// possible that the second time the handler may set the flag while it's still
// true, meaning that signal will be missed. But the first occurrence of it
// will still be handled, so this isn't a problem.
// Volatile is not necessary here for correctness, but this data _is_ volatile
// so I've marked it as such.
volatile uint8 received_signal_[kNumPosixSignals];
};
PosixSignalHandler PosixSignalHandler::instance_;
class PosixSignalDispatcher : public Dispatcher {
public:
PosixSignalDispatcher(PhysicalSocketServer *owner) : owner_(owner) {
owner_->Add(this);
}
virtual ~PosixSignalDispatcher() {
owner_->Remove(this);
}
virtual uint32 GetRequestedEvents() {
return DE_READ;
}
virtual void OnPreEvent(uint32 ff) {
// Events might get grouped if signals come very fast, so we read out up to
// 16 bytes to make sure we keep the pipe empty.
uint8 b[16];
ssize_t ret = read(GetDescriptor(), b, sizeof(b));
if (ret < 0) {
LOG_ERR(LS_WARNING) << "Error in read()";
} else if (ret == 0) {
LOG(LS_WARNING) << "Should have read at least one byte";
}
}
virtual void OnEvent(uint32 ff, int err) {
for (int signum = 0; signum < PosixSignalHandler::kNumPosixSignals;
++signum) {
if (PosixSignalHandler::Instance()->IsSignalSet(signum)) {
PosixSignalHandler::Instance()->ClearSignal(signum);
HandlerMap::iterator i = handlers_.find(signum);
if (i == handlers_.end()) {
// This can happen if a signal is delivered to our process at around
// the same time as we unset our handler for it. It is not an error
// condition, but it's unusual enough to be worth logging.
LOG(LS_INFO) << "Received signal with no handler: " << signum;
} else {
// Otherwise, execute our handler.
(*i->second)(signum);
}
}
}
}
virtual int GetDescriptor() {
return PosixSignalHandler::Instance()->GetDescriptor();
}
virtual bool IsDescriptorClosed() {
return false;
}
void SetHandler(int signum, void (*handler)(int)) {
handlers_[signum] = handler;
}
void ClearHandler(int signum) {
handlers_.erase(signum);
}
bool HasHandlers() {
return !handlers_.empty();
}
private:
typedef std::map<int, void (*)(int)> HandlerMap;
HandlerMap handlers_;
// Our owner.
PhysicalSocketServer *owner_;
};
class SocketDispatcher : public Dispatcher, public PhysicalSocket {
public:
explicit SocketDispatcher(PhysicalSocketServer *ss) : PhysicalSocket(ss) {
}
SocketDispatcher(SOCKET s, PhysicalSocketServer *ss) : PhysicalSocket(ss, s) {
}
virtual ~SocketDispatcher() {
Close();
}
bool Initialize() {
ss_->Add(this);
fcntl(s_, F_SETFL, fcntl(s_, F_GETFL, 0) | O_NONBLOCK);
return true;
}
virtual bool Create(int type) {
// Change the socket to be non-blocking.
if (!PhysicalSocket::Create(type))
return false;
return Initialize();
}
virtual int GetDescriptor() {
return s_;
}
virtual bool IsDescriptorClosed() {
// We don't have a reliable way of distinguishing end-of-stream
// from readability. So test on each readable call. Is this
// inefficient? Probably.
char ch;
ssize_t res = ::recv(s_, &ch, 1, MSG_PEEK);
if (res > 0) {
// Data available, so not closed.
return false;
} else if (res == 0) {
// EOF, so closed.
return true;
} else { // error
switch (errno) {
// Returned if we've already closed s_.
case EBADF:
// Returned during ungraceful peer shutdown.
case ECONNRESET:
return true;
default:
// Assume that all other errors are just blocking errors, meaning the
// connection is still good but we just can't read from it right now.
// This should only happen when connecting (and at most once), because
// in all other cases this function is only called if the file
// descriptor is already known to be in the readable state. However,
// it's not necessary a problem if we spuriously interpret a
// "connection lost"-type error as a blocking error, because typically
// the next recv() will get EOF, so we'll still eventually notice that
// the socket is closed.
LOG_ERR(LS_WARNING) << "Assuming benign blocking error";
return false;
}
}
}
virtual uint32 GetRequestedEvents() {
return enabled_events_;
}
virtual void OnPreEvent(uint32 ff) {
if ((ff & DE_CONNECT) != 0)
state_ = CS_CONNECTED;
if ((ff & DE_CLOSE) != 0)
state_ = CS_CLOSED;
}
virtual void OnEvent(uint32 ff, int err) {
if ((ff & DE_READ) != 0) {
enabled_events_ &= ~DE_READ;
SignalReadEvent(this);
}
if ((ff & DE_WRITE) != 0) {
enabled_events_ &= ~DE_WRITE;
SignalWriteEvent(this);
}
if ((ff & DE_CONNECT) != 0) {
enabled_events_ &= ~DE_CONNECT;
SignalConnectEvent(this);
}
if ((ff & DE_ACCEPT) != 0) {
enabled_events_ &= ~DE_ACCEPT;
SignalReadEvent(this);
}
if ((ff & DE_CLOSE) != 0) {
// The socket is now dead to us, so stop checking it.
enabled_events_ = 0;
SignalCloseEvent(this, err);
}
}
virtual int Close() {
if (s_ == INVALID_SOCKET)
return 0;
ss_->Remove(this);
return PhysicalSocket::Close();
}
};
class FileDispatcher: public Dispatcher, public AsyncFile {
public:
FileDispatcher(int fd, PhysicalSocketServer *ss) : ss_(ss), fd_(fd) {
set_readable(true);
ss_->Add(this);
fcntl(fd_, F_SETFL, fcntl(fd_, F_GETFL, 0) | O_NONBLOCK);
}
virtual ~FileDispatcher() {
ss_->Remove(this);
}
SocketServer* socketserver() { return ss_; }
virtual int GetDescriptor() {
return fd_;
}
virtual bool IsDescriptorClosed() {
return false;
}
virtual uint32 GetRequestedEvents() {
return flags_;
}
virtual void OnPreEvent(uint32 ff) {
}
virtual void OnEvent(uint32 ff, int err) {
if ((ff & DE_READ) != 0)
SignalReadEvent(this);
if ((ff & DE_WRITE) != 0)
SignalWriteEvent(this);
if ((ff & DE_CLOSE) != 0)
SignalCloseEvent(this, err);
}
virtual bool readable() {
return (flags_ & DE_READ) != 0;
}
virtual void set_readable(bool value) {
flags_ = value ? (flags_ | DE_READ) : (flags_ & ~DE_READ);
}
virtual bool writable() {
return (flags_ & DE_WRITE) != 0;
}
virtual void set_writable(bool value) {
flags_ = value ? (flags_ | DE_WRITE) : (flags_ & ~DE_WRITE);
}
private:
PhysicalSocketServer* ss_;
int fd_;
int flags_;
};
AsyncFile* PhysicalSocketServer::CreateFile(int fd) {
return new FileDispatcher(fd, this);
}
#endif // POSIX
#ifdef WIN32
static uint32 FlagsToEvents(uint32 events) {
uint32 ffFD = FD_CLOSE;
if (events & DE_READ)
ffFD |= FD_READ;
if (events & DE_WRITE)
ffFD |= FD_WRITE;
if (events & DE_CONNECT)
ffFD |= FD_CONNECT;
if (events & DE_ACCEPT)
ffFD |= FD_ACCEPT;
return ffFD;
}
class EventDispatcher : public Dispatcher {
public:
EventDispatcher(PhysicalSocketServer *ss) : ss_(ss) {
hev_ = WSACreateEvent();
if (hev_) {
ss_->Add(this);
}
}
~EventDispatcher() {
if (hev_ != NULL) {
ss_->Remove(this);
WSACloseEvent(hev_);
hev_ = NULL;
}
}
virtual void Signal() {
if (hev_ != NULL)
WSASetEvent(hev_);
}
virtual uint32 GetRequestedEvents() {
return 0;
}
virtual void OnPreEvent(uint32 ff) {
WSAResetEvent(hev_);
}
virtual void OnEvent(uint32 ff, int err) {
}
virtual WSAEVENT GetWSAEvent() {
return hev_;
}
virtual SOCKET GetSocket() {
return INVALID_SOCKET;
}
virtual bool CheckSignalClose() { return false; }
private:
PhysicalSocketServer* ss_;
WSAEVENT hev_;
};
class SocketDispatcher : public Dispatcher, public PhysicalSocket {
public:
static int next_id_;
int id_;
bool signal_close_;
int signal_err_;
SocketDispatcher(PhysicalSocketServer* ss)
: PhysicalSocket(ss),
id_(0),
signal_close_(false) {
}
SocketDispatcher(SOCKET s, PhysicalSocketServer* ss)
: PhysicalSocket(ss, s),
id_(0),
signal_close_(false) {
}
virtual ~SocketDispatcher() {
Close();
}
bool Initialize() {
ASSERT(s_ != INVALID_SOCKET);
// Must be a non-blocking
u_long argp = 1;
ioctlsocket(s_, FIONBIO, &argp);
ss_->Add(this);
return true;
}
virtual bool Create(int type) {
// Create socket
if (!PhysicalSocket::Create(type))
return false;
if (!Initialize())
return false;
do { id_ = ++next_id_; } while (id_ == 0);
return true;
}
virtual int Close() {
if (s_ == INVALID_SOCKET)
return 0;
id_ = 0;
signal_close_ = false;
ss_->Remove(this);
return PhysicalSocket::Close();
}
virtual uint32 GetRequestedEvents() {
return enabled_events_;
}
virtual void OnPreEvent(uint32 ff) {
if ((ff & DE_CONNECT) != 0)
state_ = CS_CONNECTED;
// We set CS_CLOSED from CheckSignalClose.
}
virtual void OnEvent(uint32 ff, int err) {
int cache_id = id_;
if ((ff & DE_READ) != 0) {
enabled_events_ &= ~DE_READ;
SignalReadEvent(this);
}
if (((ff & DE_WRITE) != 0) && (id_ == cache_id)) {
enabled_events_ &= ~DE_WRITE;
SignalWriteEvent(this);
}
if (((ff & DE_CONNECT) != 0) && (id_ == cache_id)) {
if (ff != DE_CONNECT)
LOG(LS_VERBOSE) << "Signalled with DE_CONNECT: " << ff;
enabled_events_ &= ~DE_CONNECT;
#ifdef _DEBUG
dbg_addr_ = "Connected @ ";
dbg_addr_.append(GetRemoteAddress().ToString());
#endif // _DEBUG
SignalConnectEvent(this);
}
if (((ff & DE_ACCEPT) != 0) && (id_ == cache_id)) {
enabled_events_ &= ~DE_ACCEPT;
SignalReadEvent(this);
}
if (((ff & DE_CLOSE) != 0) && (id_ == cache_id)) {
signal_close_ = true;
signal_err_ = err;
}
}
virtual WSAEVENT GetWSAEvent() {
return WSA_INVALID_EVENT;
}
virtual SOCKET GetSocket() {
return s_;
}
virtual bool CheckSignalClose() {
if (!signal_close_)
return false;
char ch;
if (recv(s_, &ch, 1, MSG_PEEK) > 0)
return false;
state_ = CS_CLOSED;
signal_close_ = false;
SignalCloseEvent(this, signal_err_);
return true;
}
};
int SocketDispatcher::next_id_ = 0;
#endif // WIN32
// Sets the value of a boolean value to false when signaled.
class Signaler : public EventDispatcher {
public:
Signaler(PhysicalSocketServer* ss, bool* pf)
: EventDispatcher(ss), pf_(pf) {
}
virtual ~Signaler() { }
void OnEvent(uint32 ff, int err) {
if (pf_)
*pf_ = false;
}
private:
bool *pf_;
};
PhysicalSocketServer::PhysicalSocketServer()
: fWait_(false),
last_tick_tracked_(0),
last_tick_dispatch_count_(0) {
signal_wakeup_ = new Signaler(this, &fWait_);
#ifdef WIN32
socket_ev_ = WSACreateEvent();
#endif
}
PhysicalSocketServer::~PhysicalSocketServer() {
#ifdef WIN32
WSACloseEvent(socket_ev_);
#endif
#ifdef POSIX
signal_dispatcher_.reset();
#endif
delete signal_wakeup_;
ASSERT(dispatchers_.empty());
}
void PhysicalSocketServer::WakeUp() {
signal_wakeup_->Signal();
}
Socket* PhysicalSocketServer::CreateSocket(int type) {
PhysicalSocket* socket = new PhysicalSocket(this);
if (socket->Create(type)) {
return socket;
} else {
delete socket;
return 0;
}
}
AsyncSocket* PhysicalSocketServer::CreateAsyncSocket(int type) {
SocketDispatcher* dispatcher = new SocketDispatcher(this);
if (dispatcher->Create(type)) {
return dispatcher;
} else {
delete dispatcher;
return 0;
}
}
AsyncSocket* PhysicalSocketServer::WrapSocket(SOCKET s) {
SocketDispatcher* dispatcher = new SocketDispatcher(s, this);
if (dispatcher->Initialize()) {
return dispatcher;
} else {
delete dispatcher;
return 0;
}
}
void PhysicalSocketServer::Add(Dispatcher *pdispatcher) {
CritScope cs(&crit_);
// Prevent duplicates. This can cause dead dispatchers to stick around.
DispatcherList::iterator pos = std::find(dispatchers_.begin(),
dispatchers_.end(),
pdispatcher);
if (pos != dispatchers_.end())
return;
dispatchers_.push_back(pdispatcher);
}
void PhysicalSocketServer::Remove(Dispatcher *pdispatcher) {
CritScope cs(&crit_);
DispatcherList::iterator pos = std::find(dispatchers_.begin(),
dispatchers_.end(),
pdispatcher);
ASSERT(pos != dispatchers_.end());
size_t index = pos - dispatchers_.begin();
dispatchers_.erase(pos);
for (IteratorList::iterator it = iterators_.begin(); it != iterators_.end();
++it) {
if (index < **it) {
--**it;
}
}
}
#ifdef POSIX
bool PhysicalSocketServer::Wait(int cmsWait, bool process_io) {
// Calculate timing information
struct timeval *ptvWait = NULL;
struct timeval tvWait;
struct timeval tvStop;
if (cmsWait != kForever) {
// Calculate wait timeval
tvWait.tv_sec = cmsWait / 1000;
tvWait.tv_usec = (cmsWait % 1000) * 1000;
ptvWait = &tvWait;
// Calculate when to return in a timeval
gettimeofday(&tvStop, NULL);
tvStop.tv_sec += tvWait.tv_sec;
tvStop.tv_usec += tvWait.tv_usec;
if (tvStop.tv_usec >= 1000000) {
tvStop.tv_usec -= 1000000;
tvStop.tv_sec += 1;
}
}
// Zero all fd_sets. Don't need to do this inside the loop since
// select() zeros the descriptors not signaled
fd_set fdsRead;
FD_ZERO(&fdsRead);
fd_set fdsWrite;
FD_ZERO(&fdsWrite);
fWait_ = true;
while (fWait_) {
int fdmax = -1;
{
CritScope cr(&crit_);
for (size_t i = 0; i < dispatchers_.size(); ++i) {
// Query dispatchers for read and write wait state
Dispatcher *pdispatcher = dispatchers_[i];
ASSERT(pdispatcher);
if (!process_io && (pdispatcher != signal_wakeup_))
continue;
int fd = pdispatcher->GetDescriptor();
if (fd > fdmax)
fdmax = fd;
uint32 ff = pdispatcher->GetRequestedEvents();
if (ff & (DE_READ | DE_ACCEPT))
FD_SET(fd, &fdsRead);
if (ff & (DE_WRITE | DE_CONNECT))
FD_SET(fd, &fdsWrite);
}
}
// Wait then call handlers as appropriate
// < 0 means error
// 0 means timeout
// > 0 means count of descriptors ready
int n = select(fdmax + 1, &fdsRead, &fdsWrite, NULL, ptvWait);
// If error, return error.
if (n < 0) {
if (errno != EINTR) {
LOG_E(LS_ERROR, EN, errno) << "select";
return false;
}
// Else ignore the error and keep going. If this EINTR was for one of the
// signals managed by this PhysicalSocketServer, the
// PosixSignalDeliveryDispatcher will be in the signaled state in the next
// iteration.
} else if (n == 0) {
// If timeout, return success
return true;
} else {
// We have signaled descriptors
CritScope cr(&crit_);
for (size_t i = 0; i < dispatchers_.size(); ++i) {
Dispatcher *pdispatcher = dispatchers_[i];
int fd = pdispatcher->GetDescriptor();
uint32 ff = 0;
int errcode = 0;
// Reap any error code, which can be signaled through reads or writes.
// TODO: Should we set errcode if getsockopt fails?
if (FD_ISSET(fd, &fdsRead) || FD_ISSET(fd, &fdsWrite)) {
socklen_t len = sizeof(errcode);
::getsockopt(fd, SOL_SOCKET, SO_ERROR, &errcode, &len);
}
// Check readable descriptors. If we're waiting on an accept, signal
// that. Otherwise we're waiting for data, check to see if we're
// readable or really closed.
// TODO: Only peek at TCP descriptors.
if (FD_ISSET(fd, &fdsRead)) {
FD_CLR(fd, &fdsRead);
if (pdispatcher->GetRequestedEvents() & DE_ACCEPT) {
ff |= DE_ACCEPT;
} else if (errcode || pdispatcher->IsDescriptorClosed()) {
ff |= DE_CLOSE;
} else {
ff |= DE_READ;
}
}
// Check writable descriptors. If we're waiting on a connect, detect
// success versus failure by the reaped error code.
if (FD_ISSET(fd, &fdsWrite)) {
FD_CLR(fd, &fdsWrite);
if (pdispatcher->GetRequestedEvents() & DE_CONNECT) {
if (!errcode) {
ff |= DE_CONNECT;
} else {
ff |= DE_CLOSE;
}
} else {
ff |= DE_WRITE;
}
}
// Tell the descriptor about the event.
if (ff != 0) {
pdispatcher->OnPreEvent(ff);
pdispatcher->OnEvent(ff, errcode);
}
}
}
// Recalc the time remaining to wait. Doing it here means it doesn't get
// calced twice the first time through the loop
if (cmsWait != kForever) {
ptvWait->tv_sec = 0;
ptvWait->tv_usec = 0;
struct timeval tvT;
gettimeofday(&tvT, NULL);
if ((tvStop.tv_sec > tvT.tv_sec)
|| ((tvStop.tv_sec == tvT.tv_sec)
&& (tvStop.tv_usec > tvT.tv_usec))) {
ptvWait->tv_sec = tvStop.tv_sec - tvT.tv_sec;
ptvWait->tv_usec = tvStop.tv_usec - tvT.tv_usec;
if (ptvWait->tv_usec < 0) {
ASSERT(ptvWait->tv_sec > 0);
ptvWait->tv_usec += 1000000;
ptvWait->tv_sec -= 1;
}
}
}
}
return true;
}
static void GlobalSignalHandler(int signum) {
PosixSignalHandler::Instance()->OnPosixSignalReceived(signum);
}
bool PhysicalSocketServer::SetPosixSignalHandler(int signum,
void (*handler)(int)) {
// If handler is SIG_IGN or SIG_DFL then clear our user-level handler,
// otherwise set one.
if (handler == SIG_IGN || handler == SIG_DFL) {
if (!InstallSignal(signum, handler)) {
return false;
}
if (signal_dispatcher_.get()) {
signal_dispatcher_->ClearHandler(signum);
if (!signal_dispatcher_->HasHandlers()) {
signal_dispatcher_.reset();
}
}
} else {
if (!signal_dispatcher_.get()) {
signal_dispatcher_.reset(new PosixSignalDispatcher(this));
}
signal_dispatcher_->SetHandler(signum, handler);
if (!InstallSignal(signum, &GlobalSignalHandler)) {
return false;
}
}
return true;
}
bool PhysicalSocketServer::InstallSignal(int signum, void (*handler)(int)) {
struct sigaction act;
// It doesn't really matter what we set this mask to.
if (sigemptyset(&act.sa_mask) != 0) {
LOG_ERR(LS_ERROR) << "Couldn't set mask";
return false;
}
act.sa_handler = handler;
// Use SA_RESTART so that our syscalls don't get EINTR, since we don't need it
// and it's a nuisance. Though some syscalls still return EINTR and there's no
// real standard for which ones. :(
act.sa_flags = SA_RESTART;
if (sigaction(signum, &act, NULL) != 0) {
LOG_ERR(LS_ERROR) << "Couldn't set sigaction";
return false;
}
return true;
}
#endif // POSIX
#ifdef WIN32
bool PhysicalSocketServer::Wait(int cmsWait, bool process_io) {
int cmsTotal = cmsWait;
int cmsElapsed = 0;
uint32 msStart = Time();
#if LOGGING
if (last_tick_dispatch_count_ == 0) {
last_tick_tracked_ = msStart;
}
#endif
fWait_ = true;
while (fWait_) {
std::vector<WSAEVENT> events;
std::vector<Dispatcher *> event_owners;
events.push_back(socket_ev_);
{
CritScope cr(&crit_);
size_t i = 0;
iterators_.push_back(&i);
// Don't track dispatchers_.size(), because we want to pick up any new
// dispatchers that were added while processing the loop.
while (i < dispatchers_.size()) {
Dispatcher* disp = dispatchers_[i++];
if (!process_io && (disp != signal_wakeup_))
continue;
SOCKET s = disp->GetSocket();
if (disp->CheckSignalClose()) {
// We just signalled close, don't poll this socket
} else if (s != INVALID_SOCKET) {
WSAEventSelect(s,
events[0],
FlagsToEvents(disp->GetRequestedEvents()));
} else {
events.push_back(disp->GetWSAEvent());
event_owners.push_back(disp);
}
}
ASSERT(iterators_.back() == &i);
iterators_.pop_back();
}
// Which is shorter, the delay wait or the asked wait?
int cmsNext;
if (cmsWait == kForever) {
cmsNext = cmsWait;
} else {
cmsNext = _max(0, cmsTotal - cmsElapsed);
}
// Wait for one of the events to signal
DWORD dw = WSAWaitForMultipleEvents(static_cast<DWORD>(events.size()),
&events[0],
false,
cmsNext,
false);
#if 0 // LOGGING
// we track this information purely for logging purposes.
last_tick_dispatch_count_++;
if (last_tick_dispatch_count_ >= 1000) {
int32 elapsed = TimeSince(last_tick_tracked_);
LOG(INFO) << "PhysicalSocketServer took " << elapsed
<< "ms for 1000 events";
// If we get more than 1000 events in a second, we are spinning badly
// (normally it should take about 8-20 seconds).
ASSERT(elapsed > 1000);
last_tick_tracked_ = Time();
last_tick_dispatch_count_ = 0;
}
#endif
if (dw == WSA_WAIT_FAILED) {
// Failed?
// TODO: need a better strategy than this!
int error = WSAGetLastError();
ASSERT(false);
return false;
} else if (dw == WSA_WAIT_TIMEOUT) {
// Timeout?
return true;
} else {
// Figure out which one it is and call it
CritScope cr(&crit_);
int index = dw - WSA_WAIT_EVENT_0;
if (index > 0) {
--index; // The first event is the socket event
event_owners[index]->OnPreEvent(0);
event_owners[index]->OnEvent(0, 0);
} else if (process_io) {
size_t i = 0, end = dispatchers_.size();
iterators_.push_back(&i);
iterators_.push_back(&end); // Don't iterate over new dispatchers.
while (i < end) {
Dispatcher* disp = dispatchers_[i++];
SOCKET s = disp->GetSocket();
if (s == INVALID_SOCKET)
continue;
WSANETWORKEVENTS wsaEvents;
int err = WSAEnumNetworkEvents(s, events[0], &wsaEvents);
if (err == 0) {
#if LOGGING
{
if ((wsaEvents.lNetworkEvents & FD_READ) &&
wsaEvents.iErrorCode[FD_READ_BIT] != 0) {
LOG(WARNING) << "PhysicalSocketServer got FD_READ_BIT error "
<< wsaEvents.iErrorCode[FD_READ_BIT];
}
if ((wsaEvents.lNetworkEvents & FD_WRITE) &&
wsaEvents.iErrorCode[FD_WRITE_BIT] != 0) {
LOG(WARNING) << "PhysicalSocketServer got FD_WRITE_BIT error "
<< wsaEvents.iErrorCode[FD_WRITE_BIT];
}
if ((wsaEvents.lNetworkEvents & FD_CONNECT) &&
wsaEvents.iErrorCode[FD_CONNECT_BIT] != 0) {
LOG(WARNING) << "PhysicalSocketServer got FD_CONNECT_BIT error "
<< wsaEvents.iErrorCode[FD_CONNECT_BIT];
}
if ((wsaEvents.lNetworkEvents & FD_ACCEPT) &&
wsaEvents.iErrorCode[FD_ACCEPT_BIT] != 0) {
LOG(WARNING) << "PhysicalSocketServer got FD_ACCEPT_BIT error "
<< wsaEvents.iErrorCode[FD_ACCEPT_BIT];
}
if ((wsaEvents.lNetworkEvents & FD_CLOSE) &&
wsaEvents.iErrorCode[FD_CLOSE_BIT] != 0) {
LOG(WARNING) << "PhysicalSocketServer got FD_CLOSE_BIT error "
<< wsaEvents.iErrorCode[FD_CLOSE_BIT];
}
}
#endif
uint32 ff = 0;
int errcode = 0;
if (wsaEvents.lNetworkEvents & FD_READ)
ff |= DE_READ;
if (wsaEvents.lNetworkEvents & FD_WRITE)
ff |= DE_WRITE;
if (wsaEvents.lNetworkEvents & FD_CONNECT) {
if (wsaEvents.iErrorCode[FD_CONNECT_BIT] == 0) {
ff |= DE_CONNECT;
} else {
ff |= DE_CLOSE;
errcode = wsaEvents.iErrorCode[FD_CONNECT_BIT];
}
}
if (wsaEvents.lNetworkEvents & FD_ACCEPT)
ff |= DE_ACCEPT;
if (wsaEvents.lNetworkEvents & FD_CLOSE) {
ff |= DE_CLOSE;
errcode = wsaEvents.iErrorCode[FD_CLOSE_BIT];
}
if (ff != 0) {
disp->OnPreEvent(ff);
disp->OnEvent(ff, errcode);
}
}
}
ASSERT(iterators_.back() == &end);
iterators_.pop_back();
ASSERT(iterators_.back() == &i);
iterators_.pop_back();
}
// Reset the network event until new activity occurs
WSAResetEvent(socket_ev_);
}
// Break?
if (!fWait_)
break;
cmsElapsed = TimeSince(msStart);
if ((cmsWait != kForever) && (cmsElapsed >= cmsWait)) {
break;
}
}
// Done
return true;
}
#endif // WIN32
} // namespace bruno_base