libzmq/src/tcp_listener.cpp
Martin Hurton afe9afa2a5 Set socket buffers before establishing TCP connection
The window scale option carried in SYN segment is computed from socket's
receive buffer size. So we need to set this buffer size before calling
connect or bind.
2013-06-30 07:30:51 +02:00

305 lines
8.3 KiB
C++

/*
Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file
This file is part of 0MQ.
0MQ is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
0MQ is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <new>
#include <string>
#include "platform.hpp"
#include "tcp_listener.hpp"
#include "stream_engine.hpp"
#include "io_thread.hpp"
#include "session_base.hpp"
#include "config.hpp"
#include "err.hpp"
#include "ip.hpp"
#include "tcp.hpp"
#include "socket_base.hpp"
#ifdef ZMQ_HAVE_WINDOWS
#include "windows.hpp"
#else
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/tcp.h>
#include <netinet/in.h>
#include <netdb.h>
#include <fcntl.h>
#endif
#ifdef ZMQ_HAVE_OPENVMS
#include <ioctl.h>
#endif
zmq::tcp_listener_t::tcp_listener_t (io_thread_t *io_thread_,
socket_base_t *socket_, const options_t &options_) :
own_t (io_thread_, options_),
io_object_t (io_thread_),
s (retired_fd),
socket (socket_)
{
}
zmq::tcp_listener_t::~tcp_listener_t ()
{
zmq_assert (s == retired_fd);
}
void zmq::tcp_listener_t::process_plug ()
{
// Start polling for incoming connections.
handle = add_fd (s);
set_pollin (handle);
}
void zmq::tcp_listener_t::process_term (int linger_)
{
rm_fd (handle);
close ();
own_t::process_term (linger_);
}
void zmq::tcp_listener_t::in_event ()
{
fd_t fd = accept ();
// If connection was reset by the peer in the meantime, just ignore it.
// TODO: Handle specific errors like ENFILE/EMFILE etc.
if (fd == retired_fd) {
socket->event_accept_failed (endpoint, zmq_errno());
return;
}
tune_tcp_socket (fd);
tune_tcp_keepalives (fd, options.tcp_keepalive, options.tcp_keepalive_cnt, options.tcp_keepalive_idle, options.tcp_keepalive_intvl);
// Create the engine object for this connection.
stream_engine_t *engine = new (std::nothrow)
stream_engine_t (fd, options, endpoint);
alloc_assert (engine);
// Choose I/O thread to run connecter in. Given that we are already
// running in an I/O thread, there must be at least one available.
io_thread_t *io_thread = choose_io_thread (options.affinity);
zmq_assert (io_thread);
// Create and launch a session object.
session_base_t *session = session_base_t::create (io_thread, false, socket,
options, NULL);
errno_assert (session);
session->inc_seqnum ();
launch_child (session);
send_attach (session, engine, false);
socket->event_accepted (endpoint, fd);
}
void zmq::tcp_listener_t::close ()
{
zmq_assert (s != retired_fd);
#ifdef ZMQ_HAVE_WINDOWS
int rc = closesocket (s);
wsa_assert (rc != SOCKET_ERROR);
#else
int rc = ::close (s);
errno_assert (rc == 0);
#endif
socket->event_closed (endpoint, s);
s = retired_fd;
}
int zmq::tcp_listener_t::get_address (std::string &addr_)
{
// Get the details of the TCP socket
struct sockaddr_storage ss;
#ifdef ZMQ_HAVE_HPUX
int sl = sizeof (ss);
#else
socklen_t sl = sizeof (ss);
#endif
int rc = getsockname (s, (struct sockaddr *) &ss, &sl);
if (rc != 0) {
addr_.clear ();
return rc;
}
tcp_address_t addr ((struct sockaddr *) &ss, sl);
return addr.to_string (addr_);
}
int zmq::tcp_listener_t::set_address (const char *addr_)
{
// Convert the textual address into address structure.
int rc = address.resolve (addr_, true, options.ipv6);
if (rc != 0)
return -1;
// Create a listening socket.
s = open_socket (address.family (), SOCK_STREAM, IPPROTO_TCP);
#ifdef ZMQ_HAVE_WINDOWS
if (s == INVALID_SOCKET)
errno = wsa_error_to_errno (WSAGetLastError ());
#endif
// IPv6 address family not supported, try automatic downgrade to IPv4.
if (address.family () == AF_INET6
&& errno == EAFNOSUPPORT
&& options.ipv6) {
rc = address.resolve (addr_, true, true);
if (rc != 0)
return rc;
s = ::socket (address.family (), SOCK_STREAM, IPPROTO_TCP);
}
#ifdef ZMQ_HAVE_WINDOWS
if (s == INVALID_SOCKET) {
errno = wsa_error_to_errno (WSAGetLastError ());
return -1;
}
#if !defined _WIN32_WCE
// On Windows, preventing sockets to be inherited by child processes.
BOOL brc = SetHandleInformation ((HANDLE) s, HANDLE_FLAG_INHERIT, 0);
win_assert (brc);
#endif
#else
if (s == -1)
return -1;
#endif
// On some systems, IPv4 mapping in IPv6 sockets is disabled by default.
// Switch it on in such cases.
if (address.family () == AF_INET6)
enable_ipv4_mapping (s);
// Set the socket buffer limits for the underlying socket.
if (options.sndbuf != 0)
set_tcp_send_buffer (s, options.sndbuf);
if (options.rcvbuf != 0)
set_tcp_receive_buffer (s, options.rcvbuf);
// Allow reusing of the address.
int flag = 1;
#ifdef ZMQ_HAVE_WINDOWS
rc = setsockopt (s, SOL_SOCKET, SO_EXCLUSIVEADDRUSE,
(const char*) &flag, sizeof (int));
wsa_assert (rc != SOCKET_ERROR);
#else
rc = setsockopt (s, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof (int));
errno_assert (rc == 0);
#endif
address.to_string (endpoint);
// Bind the socket to the network interface and port.
rc = bind (s, address.addr (), address.addrlen ());
#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 incomming 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
socket->event_listening (endpoint, s);
return 0;
error:
int err = errno;
close ();
errno = err;
return -1;
}
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));
#ifdef ZMQ_HAVE_HPUX
int ss_len = sizeof (ss);
#else
socklen_t ss_len = sizeof (ss);
#endif
fd_t sock = ::accept (s, (struct sockaddr *) &ss, &ss_len);
#ifdef ZMQ_HAVE_WINDOWS
if (sock == INVALID_SOCKET) {
wsa_assert (WSAGetLastError () == WSAEWOULDBLOCK ||
WSAGetLastError () == WSAECONNRESET ||
WSAGetLastError () == WSAEMFILE ||
WSAGetLastError () == WSAENOBUFS);
return retired_fd;
}
#if !defined _WIN32_WCE
// On Windows, preventing sockets to be inherited by child processes.
BOOL brc = SetHandleInformation ((HANDLE) sock, HANDLE_FLAG_INHERIT, 0);
win_assert (brc);
#endif
#else
if (sock == -1) {
errno_assert (errno == EAGAIN || errno == EWOULDBLOCK ||
errno == EINTR || errno == ECONNABORTED || errno == EPROTO ||
errno == ENOBUFS || errno == ENOMEM || errno == EMFILE ||
errno == ENFILE);
return retired_fd;
}
#endif
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 ((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;
}
}
return sock;
}