zmq: add support for TIPC transport

A ZeroMQ application can opt for TIPC based sockets
using the TIPC port name format:
zmq_bind(sb, "tipc://{type,lower,upper}");
zmq_connect(sc, "tipc://{type,inst}");

'type' is the service ID, and 'lower/upper' can be
used for service partitioning or basic load
balancing.

ZeroMQ TIPC transport requires a kernel >= 3.8
(nonblocking connect support for TIPC).

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>

src/tipc_connecter.cpp

@@ -0,0 +1,256 @@
+/*
+    Copyright (c) 2013 Ericsson AB
+
+    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 "tipc_connecter.hpp"
+
+#if defined ZMQ_HAVE_LINUX
+
+#include <new>
+#include <string>
+
+#include "stream_engine.hpp"
+#include "io_thread.hpp"
+#include "platform.hpp"
+#include "random.hpp"
+#include "err.hpp"
+#include "ip.hpp"
+#include "address.hpp"
+#include "tipc_address.hpp"
+#include "session_base.hpp"
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+zmq::tipc_connecter_t::tipc_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 == "tipc");
+    addr->to_string (endpoint);
+    socket = session-> get_socket();
+}
+
+zmq::tipc_connecter_t::~tipc_connecter_t ()
+{
+    zmq_assert (!timer_started);
+    zmq_assert (!handle_valid);
+    zmq_assert (s == retired_fd);
+}
+
+void zmq::tipc_connecter_t::process_plug ()
+{
+    if (delayed_start)
+        add_reconnect_timer ();
+    else
+        start_connecting ();
+}
+
+void zmq::tipc_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::tipc_connecter_t::in_event ()
+{
+    //  We are not polling for incomming 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::tipc_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;
+    }
+    //  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::tipc_connecter_t::timer_event (int id_)
+{
+    zmq_assert (id_ == reconnect_timer_id);
+    timer_started = false;
+    start_connecting ();
+}
+
+void zmq::tipc_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::tipc_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::tipc_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::tipc_connecter_t::open ()
+{
+    zmq_assert (s == retired_fd);
+
+    //  Create the socket.
+    s = open_socket (AF_TIPC, SOCK_STREAM, 0);
+    if (s == -1)
+        return -1;
+
+    //  Set the non-blocking flag.
+    unblock_socket (s);
+    //  Connect to the remote peer.
+    int rc = ::connect (
+      s, addr->resolved.tipc_addr->addr (),
+      addr->resolved.tipc_addr->addrlen ());
+
+    //  Connect was successfull immediately.
+    if (rc == 0)
+        return 0;
+
+    //  Translate other error codes indicating asynchronous connect has been
+    //  launched to a uniform EINPROGRESS.
+    if (rc == -1 && errno == EINTR) {
+        errno = EINPROGRESS;
+        return -1;
+    }
+    //  Forward the error.
+    return -1;
+}
+
+void zmq::tipc_connecter_t::close ()
+{
+    zmq_assert (s != retired_fd);
+    int rc = ::close (s);
+    errno_assert (rc == 0);
+    socket->event_closed (endpoint, s);
+    s = retired_fd;
+}
+
+zmq::fd_t zmq::tipc_connecter_t::connect ()
+{
+    //  Following code should handle both Berkeley-derived socket
+    //  implementations and Solaris.
+    int err = 0;
+    socklen_t len = sizeof (err);
+
+    int rc = getsockopt (s, SOL_SOCKET, SO_ERROR, (char*) &err, &len);
+    if (rc == -1)
+        err = errno;
+    if (err != 0) {
+
+        //  Assert if the error was caused by 0MQ bug.
+        //  Networking problems are OK. No need to assert.
+        errno = err;
+        errno_assert (errno == ECONNREFUSED || errno == ECONNRESET ||
+            errno == ETIMEDOUT || errno == EHOSTUNREACH ||
+            errno == ENETUNREACH || errno == ENETDOWN);
+
+        return retired_fd;
+    }
+    fd_t result = s;
+    s = retired_fd;
+    return result;
+}
+
+#endif
+