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libzmq/src/tcp_connecter.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

325 lines
8.5 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 "tcp_connecter.hpp"
#include "stream_engine.hpp"
#include "io_thread.hpp"
#include "platform.hpp"
#include "random.hpp"
#include "err.hpp"
#include "ip.hpp"
#include "tcp.hpp"
#include "address.hpp"
#include "tcp_address.hpp"
#include "session_base.hpp"
#if defined ZMQ_HAVE_WINDOWS
#include "windows.hpp"
#else
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/tcp.h>
#include <netinet/in.h>
#include <netdb.h>
#include <fcntl.h>
#ifdef ZMQ_HAVE_OPENVMS
#include <ioctl.h>
#endif
#endif
zmq::tcp_connecter_t::tcp_connecter_t (class io_thread_t *io_thread_,
class session_base_t *session_, const options_t &options_,
const address_t *addr_, bool delayed_start_) :
own_t (io_thread_, options_),
io_object_t (io_thread_),
addr (addr_),
s (retired_fd),
handle_valid (false),
delayed_start (delayed_start_),
timer_started (false),
session (session_),
current_reconnect_ivl(options.reconnect_ivl)
{
zmq_assert (addr);
zmq_assert (addr->protocol == "tcp");
addr->to_string (endpoint);
socket = session-> get_socket();
}
zmq::tcp_connecter_t::~tcp_connecter_t ()
{
zmq_assert (!timer_started);
zmq_assert (!handle_valid);
zmq_assert (s == retired_fd);
}
void zmq::tcp_connecter_t::process_plug ()
{
if (delayed_start)
add_reconnect_timer ();
else
start_connecting ();
}
void zmq::tcp_connecter_t::process_term (int linger_)
{
if (timer_started) {
cancel_timer (reconnect_timer_id);
timer_started = false;
}
if (handle_valid) {
rm_fd (handle);
handle_valid = false;
}
if (s != retired_fd)
close ();
own_t::process_term (linger_);
}
void zmq::tcp_connecter_t::in_event ()
{
// We are not polling for incoming data, so we are actually called
// because of error here. However, we can get error on out event as well
// on some platforms, so we'll simply handle both events in the same way.
out_event ();
}
void zmq::tcp_connecter_t::out_event ()
{
fd_t fd = connect ();
rm_fd (handle);
handle_valid = false;
// Handle the error condition by attempt to reconnect.
if (fd == retired_fd) {
close ();
add_reconnect_timer();
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);
// Attach the engine to the corresponding session object.
send_attach (session, engine);
// Shut the connecter down.
terminate ();
socket->event_connected (endpoint, fd);
}
void zmq::tcp_connecter_t::timer_event (int id_)
{
zmq_assert (id_ == reconnect_timer_id);
timer_started = false;
start_connecting ();
}
void zmq::tcp_connecter_t::start_connecting ()
{
// Open the connecting socket.
int rc = open ();
// Connect may succeed in synchronous manner.
if (rc == 0) {
handle = add_fd (s);
handle_valid = true;
out_event ();
}
// Connection establishment may be delayed. Poll for its completion.
else
if (rc == -1 && errno == EINPROGRESS) {
handle = add_fd (s);
handle_valid = true;
set_pollout (handle);
socket->event_connect_delayed (endpoint, zmq_errno());
}
// Handle any other error condition by eventual reconnect.
else {
if (s != retired_fd)
close ();
add_reconnect_timer ();
}
}
void zmq::tcp_connecter_t::add_reconnect_timer()
{
int rc_ivl = get_new_reconnect_ivl();
add_timer (rc_ivl, reconnect_timer_id);
socket->event_connect_retried (endpoint, rc_ivl);
timer_started = true;
}
int zmq::tcp_connecter_t::get_new_reconnect_ivl ()
{
// The new interval is the current interval + random value.
int this_interval = current_reconnect_ivl +
(generate_random () % options.reconnect_ivl);
// Only change the current reconnect interval if the maximum reconnect
// interval was set and if it's larger than the reconnect interval.
if (options.reconnect_ivl_max > 0 &&
options.reconnect_ivl_max > options.reconnect_ivl) {
// Calculate the next interval
current_reconnect_ivl = current_reconnect_ivl * 2;
if(current_reconnect_ivl >= options.reconnect_ivl_max) {
current_reconnect_ivl = options.reconnect_ivl_max;
}
}
return this_interval;
}
int zmq::tcp_connecter_t::open ()
{
zmq_assert (s == retired_fd);
// Create the socket.
s = open_socket (addr->resolved.tcp_addr->family (), SOCK_STREAM, IPPROTO_TCP);
#ifdef ZMQ_HAVE_WINDOWS
if (s == INVALID_SOCKET) {
errno = wsa_error_to_errno (WSAGetLastError ());
return -1;
}
#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 (addr->resolved.tcp_addr->family () == AF_INET6)
enable_ipv4_mapping (s);
// Set the socket to non-blocking mode so that we get async connect().
unblock_socket (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);
// Connect to the remote peer.
int rc = ::connect (
s, addr->resolved.tcp_addr->addr (),
addr->resolved.tcp_addr->addrlen ());
// Connect was successfull immediately.
if (rc == 0)
return 0;
// Translate error codes indicating asynchronous connect has been
// launched to a uniform EINPROGRESS.
#ifdef ZMQ_HAVE_WINDOWS
const int error_code = WSAGetLastError ();
if (error_code == WSAEINPROGRESS || error_code == WSAEWOULDBLOCK)
errno = EINPROGRESS;
else
errno = wsa_error_to_errno (error_code);
#else
if (errno == EINTR)
errno = EINPROGRESS;
#endif
return -1;
}
zmq::fd_t zmq::tcp_connecter_t::connect ()
{
// Async connect has finished. Check whether an error occurred
int err = 0;
#if defined ZMQ_HAVE_HPUX
int len = sizeof (err);
#else
socklen_t len = sizeof (err);
#endif
int rc = getsockopt (s, SOL_SOCKET, SO_ERROR, (char*) &err, &len);
// Assert if the error was caused by 0MQ bug.
// Networking problems are OK. No need to assert.
#ifdef ZMQ_HAVE_WINDOWS
zmq_assert (rc == 0);
if (err != 0) {
if (err == WSAECONNREFUSED ||
err == WSAETIMEDOUT ||
err == WSAECONNABORTED ||
err == WSAEHOSTUNREACH ||
err == WSAENETUNREACH ||
err == WSAENETDOWN ||
err == WSAEINVAL)
return retired_fd;
wsa_assert_no (err);
}
#else
// Following code should handle both Berkeley-derived socket
// implementations and Solaris.
if (rc == -1)
err = errno;
if (err != 0) {
errno = err;
errno_assert (
errno == ECONNREFUSED ||
errno == ECONNRESET ||
errno == ETIMEDOUT ||
errno == EHOSTUNREACH ||
errno == ENETUNREACH ||
errno == ENETDOWN ||
errno == EINVAL);
return retired_fd;
}
#endif
// Return the newly connected socket.
fd_t result = s;
s = retired_fd;
return result;
}
void zmq::tcp_connecter_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;
}