zmq::fd_t zmq::open_socket (int domain_, int type_, int protocol_)
{
int rc;
// Setting this option result in sane behaviour when exec() functions
// are used. Old sockets are closed and don't block TCP ports etc.
#if defined ZMQ_HAVE_SOCK_CLOEXEC
type_ |= SOCK_CLOEXEC;
#endif
#if defined ZMQ_HAVE_WINDOWS && defined WSA_FLAG_NO_HANDLE_INHERIT
// if supported, create socket with WSA_FLAG_NO_HANDLE_INHERIT, such that
// the race condition in making it non-inheritable later is avoided
const fd_t s = WSASocket (domain_, type_, protocol_, NULL, 0,
WSA_FLAG_NO_HANDLE_INHERIT);
#else
const fd_t s = socket (domain_, type_, protocol_);
#endif
if (s == retired_fd) {
#ifdef ZMQ_HAVE_WINDOWS
errno = wsa_error_to_errno (WSAGetLastError ());
#endif
return retired_fd;
}
make_socket_noninheritable (s);
// Socket is not yet connected so EINVAL is not a valid networking error
rc = zmq::set_nosigpipe (s);
errno_assert (rc == 0);
return s;
}
zmq::fd_t zmq::tcp_listener_t::accept ()
{
// The situation where connection cannot be accepted due to insufficient
// resources is considered valid and treated by ignoring the connection.
// Accept one connection and deal with different failure modes.
zmq_assert (_s != retired_fd);
struct sockaddr_storage ss;
memset (&ss, 0, sizeof (ss));
#if defined ZMQ_HAVE_HPUX || defined ZMQ_HAVE_VXWORKS
int ss_len = sizeof (ss);
#else
socklen_t ss_len = sizeof (ss);
#endif
#if defined ZMQ_HAVE_SOCK_CLOEXEC && defined HAVE_ACCEPT4
fd_t sock = ::accept4 (_s, reinterpret_cast<struct sockaddr *> (&ss),
&ss_len, SOCK_CLOEXEC);
#else
fd_t sock =
::accept (_s, reinterpret_cast<struct sockaddr *> (&ss), &ss_len);
#endif
if (sock == retired_fd) {
#if defined ZMQ_HAVE_WINDOWS
const int last_error = WSAGetLastError ();
wsa_assert (last_error == WSAEWOULDBLOCK || last_error == WSAECONNRESET
|| last_error == WSAEMFILE || last_error == WSAENOBUFS);
#elif defined ZMQ_HAVE_ANDROID
errno_assert (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR
|| errno == ECONNABORTED || errno == EPROTO
|| errno == ENOBUFS || errno == ENOMEM || errno == EMFILE
|| errno == ENFILE || errno == EINVAL);
#else
errno_assert (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR
|| errno == ECONNABORTED || errno == EPROTO
|| errno == ENOBUFS || errno == ENOMEM || errno == EMFILE
|| errno == ENFILE);
#endif
return retired_fd;
}
make_socket_noninheritable (sock);
if (!options.tcp_accept_filters.empty ()) {
bool matched = false;
for (options_t::tcp_accept_filters_t::size_type i = 0;
i != options.tcp_accept_filters.size (); ++i) {
if (options.tcp_accept_filters[i].match_address (
reinterpret_cast<struct sockaddr *> (&ss), ss_len)) {
matched = true;
break;
}
}
if (!matched) {
#ifdef ZMQ_HAVE_WINDOWS
int rc = closesocket (sock);
wsa_assert (rc != SOCKET_ERROR);
#else
int rc = ::close (sock);
errno_assert (rc == 0);
#endif
return retired_fd;
}
}
if (zmq::set_nosigpipe (sock)) {
#ifdef ZMQ_HAVE_WINDOWS
int rc = closesocket (sock);
wsa_assert (rc != SOCKET_ERROR);
#else
int rc = ::close (sock);
errno_assert (rc == 0);
#endif
return retired_fd;
}
// Set the IP Type-Of-Service priority for this client socket
if (options.tos != 0)
set_ip_type_of_service (sock, options.tos);
return sock;
}
int zmq::tcp_listener_t::create_socket (const char *addr_)
{
_s = tcp_open_socket (addr_, options, true, true, &_address);
if (_s == retired_fd) {
return -1;
}
// TODO why is this only done for the listener?
make_socket_noninheritable (_s);
// Allow reusing of the address.
int flag = 1;
int rc;
#ifdef ZMQ_HAVE_WINDOWS
// TODO this was changed for Windows from SO_REUSEADDRE to
// SE_EXCLUSIVEADDRUSE by 0ab65324195ad70205514d465b03d851a6de051c,
// so the comment above is no longer correct; also, now the settings are
// different between listener and connecter with a src address.
// is this intentional?
rc = setsockopt (_s, SOL_SOCKET, SO_EXCLUSIVEADDRUSE,
reinterpret_cast<const char *> (&flag), sizeof (int));
wsa_assert (rc != SOCKET_ERROR);
#elif defined ZMQ_HAVE_VXWORKS
rc =
setsockopt (_s, SOL_SOCKET, SO_REUSEADDR, (char *) &flag, sizeof (int));
errno_assert (rc == 0);
#else
rc = setsockopt (_s, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof (int));
errno_assert (rc == 0);
#endif
// Bind the socket to the network interface and port.
#if defined ZMQ_HAVE_VXWORKS
rc = bind (_s, (sockaddr *) _address.addr (), _address.addrlen ());
#else
rc = bind (_s, _address.addr (), _address.addrlen ());
#endif
#ifdef ZMQ_HAVE_WINDOWS
if (rc == SOCKET_ERROR) {
errno = wsa_error_to_errno (WSAGetLastError ());
goto error;
}
#else
if (rc != 0)
goto error;
#endif
// Listen for incoming connections.
rc = listen (_s, options.backlog);
#ifdef ZMQ_HAVE_WINDOWS
if (rc == SOCKET_ERROR) {
errno = wsa_error_to_errno (WSAGetLastError ());
goto error;
}
#else
if (rc != 0)
goto error;
#endif
return 0;
error:
int err = errno;
close ();
errno = err;
return -1;
}
int zmq::make_fdpair (fd_t *r_, fd_t *w_)
{
#if defined ZMQ_HAVE_EVENTFD
int flags = 0;
#if defined ZMQ_HAVE_EVENTFD_CLOEXEC
// Setting this option result in sane behaviour when exec() functions
// are used. Old sockets are closed and don't block TCP ports, avoid
// leaks, etc.
flags |= EFD_CLOEXEC;
#endif
fd_t fd = eventfd (0, flags);
if (fd == -1) {
errno_assert (errno == ENFILE || errno == EMFILE);
*w_ = *r_ = -1;
return -1;
} else {
*w_ = *r_ = fd;
return 0;
}
#elif defined ZMQ_HAVE_WINDOWS
#if !defined _WIN32_WCE && !defined ZMQ_HAVE_WINDOWS_UWP
// Windows CE does not manage security attributes
SECURITY_DESCRIPTOR sd;
SECURITY_ATTRIBUTES sa;
memset (&sd, 0, sizeof sd);
memset (&sa, 0, sizeof sa);
InitializeSecurityDescriptor (&sd, SECURITY_DESCRIPTOR_REVISION);
SetSecurityDescriptorDacl (&sd, TRUE, 0, FALSE);
sa.nLength = sizeof (SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor = &sd;
#endif
// This function has to be in a system-wide critical section so that
// two instances of the library don't accidentally create signaler
// crossing the process boundary.
// We'll use named event object to implement the critical section.
// Note that if the event object already exists, the CreateEvent requests
// EVENT_ALL_ACCESS access right. If this fails, we try to open
// the event object asking for SYNCHRONIZE access only.
HANDLE sync = NULL;
// Create critical section only if using fixed signaler port
// Use problematic Event implementation for compatibility if using old port 5905.
// Otherwise use Mutex implementation.
int event_signaler_port = 5905;
if (signaler_port == event_signaler_port) {
#if !defined _WIN32_WCE && !defined ZMQ_HAVE_WINDOWS_UWP
sync =
CreateEventW (&sa, FALSE, TRUE, L"Global\\zmq-signaler-port-sync");
#else
sync =
CreateEventW (NULL, FALSE, TRUE, L"Global\\zmq-signaler-port-sync");
#endif
if (sync == NULL && GetLastError () == ERROR_ACCESS_DENIED)
sync = OpenEventW (SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE,
L"Global\\zmq-signaler-port-sync");
win_assert (sync != NULL);
} else if (signaler_port != 0) {
wchar_t mutex_name[MAX_PATH];
#ifdef __MINGW32__
_snwprintf (mutex_name, MAX_PATH, L"Global\\zmq-signaler-port-%d",
signaler_port);
#else
swprintf (mutex_name, MAX_PATH, L"Global\\zmq-signaler-port-%d",
signaler_port);
#endif
#if !defined _WIN32_WCE && !defined ZMQ_HAVE_WINDOWS_UWP
sync = CreateMutexW (&sa, FALSE, mutex_name);
#else
sync = CreateMutexW (NULL, FALSE, mutex_name);
#endif
if (sync == NULL && GetLastError () == ERROR_ACCESS_DENIED)
sync = OpenMutexW (SYNCHRONIZE, FALSE, mutex_name);
win_assert (sync != NULL);
}
// Windows has no 'socketpair' function. CreatePipe is no good as pipe
// handles cannot be polled on. Here we create the socketpair by hand.
*w_ = INVALID_SOCKET;
*r_ = INVALID_SOCKET;
// Create listening socket.
SOCKET listener;
listener = open_socket (AF_INET, SOCK_STREAM, 0);
wsa_assert (listener != INVALID_SOCKET);
// Set SO_REUSEADDR and TCP_NODELAY on listening socket.
BOOL so_reuseaddr = 1;
int rc = setsockopt (listener, SOL_SOCKET, SO_REUSEADDR,
reinterpret_cast<char *> (&so_reuseaddr),
sizeof so_reuseaddr);
wsa_assert (rc != SOCKET_ERROR);
tune_socket (listener);
// Init sockaddr to signaler port.
struct sockaddr_in addr;
memset (&addr, 0, sizeof addr);
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
addr.sin_port = htons (signaler_port);
// Create the writer socket.
*w_ = open_socket (AF_INET, SOCK_STREAM, 0);
wsa_assert (*w_ != INVALID_SOCKET);
// Set TCP_NODELAY on writer socket.
tune_socket (*w_);
if (sync != NULL) {
// Enter the critical section.
DWORD dwrc = WaitForSingleObject (sync, INFINITE);
zmq_assert (dwrc == WAIT_OBJECT_0 || dwrc == WAIT_ABANDONED);
}
// Bind listening socket to signaler port.
rc = bind (listener, reinterpret_cast<const struct sockaddr *> (&addr),
sizeof addr);
if (rc != SOCKET_ERROR && signaler_port == 0) {
// Retrieve ephemeral port number
int addrlen = sizeof addr;
rc = getsockname (listener, reinterpret_cast<struct sockaddr *> (&addr),
&addrlen);
}
// Listen for incoming connections.
if (rc != SOCKET_ERROR)
rc = listen (listener, 1);
// Connect writer to the listener.
if (rc != SOCKET_ERROR)
rc = connect (*w_, reinterpret_cast<struct sockaddr *> (&addr),
sizeof addr);
// Accept connection from writer.
if (rc != SOCKET_ERROR)
*r_ = accept (listener, NULL, NULL);
// Send/receive large chunk to work around TCP slow start
// This code is a workaround for #1608
if (*r_ != INVALID_SOCKET) {
size_t dummy_size =
1024 * 1024; // 1M to overload default receive buffer
unsigned char *dummy =
static_cast<unsigned char *> (malloc (dummy_size));
wsa_assert (dummy);
int still_to_send = static_cast<int> (dummy_size);
int still_to_recv = static_cast<int> (dummy_size);
while (still_to_send || still_to_recv) {
int nbytes;
if (still_to_send > 0) {
nbytes = ::send (
*w_,
reinterpret_cast<char *> (dummy + dummy_size - still_to_send),
still_to_send, 0);
wsa_assert (nbytes != SOCKET_ERROR);
still_to_send -= nbytes;
}
nbytes = ::recv (
*r_,
reinterpret_cast<char *> (dummy + dummy_size - still_to_recv),
still_to_recv, 0);
wsa_assert (nbytes != SOCKET_ERROR);
still_to_recv -= nbytes;
}
free (dummy);
}
// Save errno if error occurred in bind/listen/connect/accept.
int saved_errno = 0;
if (*r_ == INVALID_SOCKET)
saved_errno = WSAGetLastError ();
// We don't need the listening socket anymore. Close it.
rc = closesocket (listener);
wsa_assert (rc != SOCKET_ERROR);
if (sync != NULL) {
// Exit the critical section.
BOOL brc;
if (signaler_port == event_signaler_port)
brc = SetEvent (sync);
else
brc = ReleaseMutex (sync);
win_assert (brc != 0);
// Release the kernel object
brc = CloseHandle (sync);
win_assert (brc != 0);
}
if (*r_ != INVALID_SOCKET) {
make_socket_noninheritable (*r_);
return 0;
} else {
// Cleanup writer if connection failed
if (*w_ != INVALID_SOCKET) {
rc = closesocket (*w_);
wsa_assert (rc != SOCKET_ERROR);
*w_ = INVALID_SOCKET;
}
// Set errno from saved value
errno = wsa_error_to_errno (saved_errno);
return -1;
}
#elif defined ZMQ_HAVE_OPENVMS
// Whilst OpenVMS supports socketpair - it maps to AF_INET only. Further,
// it does not set the socket options TCP_NODELAY and TCP_NODELACK which
// can lead to performance problems.
//
// The bug will be fixed in V5.6 ECO4 and beyond. In the meantime, we'll
// create the socket pair manually.
struct sockaddr_in lcladdr;
memset (&lcladdr, 0, sizeof lcladdr);
lcladdr.sin_family = AF_INET;
lcladdr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
lcladdr.sin_port = 0;
int listener = open_socket (AF_INET, SOCK_STREAM, 0);
errno_assert (listener != -1);
int on = 1;
int rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on);
errno_assert (rc != -1);
rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELACK, &on, sizeof on);
errno_assert (rc != -1);
rc = bind (listener, (struct sockaddr *) &lcladdr, sizeof lcladdr);
errno_assert (rc != -1);
socklen_t lcladdr_len = sizeof lcladdr;
rc = getsockname (listener, (struct sockaddr *) &lcladdr, &lcladdr_len);
errno_assert (rc != -1);
rc = listen (listener, 1);
errno_assert (rc != -1);
*w_ = open_socket (AF_INET, SOCK_STREAM, 0);
errno_assert (*w_ != -1);
rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY, &on, sizeof on);
errno_assert (rc != -1);
rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELACK, &on, sizeof on);
errno_assert (rc != -1);
rc = connect (*w_, (struct sockaddr *) &lcladdr, sizeof lcladdr);
errno_assert (rc != -1);
*r_ = accept (listener, NULL, NULL);
errno_assert (*r_ != -1);
close (listener);
return 0;
#elif defined ZMQ_HAVE_VXWORKS
struct sockaddr_in lcladdr;
memset (&lcladdr, 0, sizeof lcladdr);
lcladdr.sin_family = AF_INET;
lcladdr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
lcladdr.sin_port = 0;
int listener = open_socket (AF_INET, SOCK_STREAM, 0);
errno_assert (listener != -1);
int on = 1;
int rc =
setsockopt (listener, IPPROTO_TCP, TCP_NODELAY, (char *) &on, sizeof on);
errno_assert (rc != -1);
rc = bind (listener, (struct sockaddr *) &lcladdr, sizeof lcladdr);
errno_assert (rc != -1);
socklen_t lcladdr_len = sizeof lcladdr;
rc = getsockname (listener, (struct sockaddr *) &lcladdr,
(int *) &lcladdr_len);
errno_assert (rc != -1);
rc = listen (listener, 1);
errno_assert (rc != -1);
*w_ = open_socket (AF_INET, SOCK_STREAM, 0);
errno_assert (*w_ != -1);
rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY, (char *) &on, sizeof on);
errno_assert (rc != -1);
rc = connect (*w_, (struct sockaddr *) &lcladdr, sizeof lcladdr);
errno_assert (rc != -1);
*r_ = accept (listener, NULL, NULL);
errno_assert (*r_ != -1);
close (listener);
return 0;
#else
// All other implementations support socketpair()
int sv[2];
int type = SOCK_STREAM;
// Setting this option result in sane behaviour when exec() functions
// are used. Old sockets are closed and don't block TCP ports, avoid
// leaks, etc.
#if defined ZMQ_HAVE_SOCK_CLOEXEC
type |= SOCK_CLOEXEC;
#endif
int rc = socketpair (AF_UNIX, type, 0, sv);
if (rc == -1) {
errno_assert (errno == ENFILE || errno == EMFILE);
*w_ = *r_ = -1;
return -1;
} else {
make_socket_noninheritable (sv[0]);
make_socket_noninheritable (sv[1]);
*w_ = sv[0];
*r_ = sv[1];
return 0;
}
#endif
}
