/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single TCP/UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "syshead.h"
#if P2MP_SERVER
#include "multi.h"
#include "forward-inline.h"
#include "memdbg.h"
/*
* Get a client instance based on real address. If
* the instance doesn't exist, create it while
* maintaining real address hash table atomicity.
*/
struct multi_instance *
multi_get_create_instance_udp (struct multi_context *m)
{
struct gc_arena gc = gc_new ();
struct mroute_addr real;
struct multi_instance *mi = NULL;
struct hash *hash = m->hash;
if (mroute_extract_openvpn_sockaddr (&real, &m->top.c2.from.dest, true))
{
struct hash_element *he;
const uint32_t hv = hash_value (hash, &real);
struct hash_bucket *bucket = hash_bucket (hash, hv);
he = hash_lookup_fast (hash, bucket, &real, hv);
if (he)
{
mi = (struct multi_instance *) he->value;
}
else
{
if (!m->top.c2.tls_auth_standalone
|| tls_pre_decrypt_lite (m->top.c2.tls_auth_standalone, &m->top.c2.from, &m->top.c2.buf))
{
if (frequency_limit_event_allowed (m->new_connection_limiter))
{
mi = multi_create_instance (m, &real);
if (mi)
{
hash_add_fast (hash, bucket, &mi->real, hv, mi);
mi->did_real_hash = true;
}
}
else
{
msg (D_MULTI_ERRORS,
"MULTI: Connection from %s would exceed new connection frequency limit as controlled by --connect-freq",
mroute_addr_print (&real, &gc));
}
}
}
#ifdef ENABLE_DEBUG
if (check_debug_level (D_MULTI_DEBUG))
{
const char *status;
if (he && mi)
status = "[succeeded]";
else if (!he && mi)
status = "[created]";
else
status = "[failed]";
dmsg (D_MULTI_DEBUG, "GET INST BY REAL: %s %s",
mroute_addr_print (&real, &gc),
status);
}
#endif
}
gc_free (&gc);
ASSERT (!(mi && mi->halt));
return mi;
}
/*
* Send a packet to TCP/UDP socket.
*/
static inline void
multi_process_outgoing_link (struct multi_context *m, const unsigned int mpp_flags)
{
struct multi_instance *mi = multi_process_outgoing_link_pre (m);
if (mi)
multi_process_outgoing_link_dowork (m, mi, mpp_flags);
}
/*
* Process an I/O event.
*/
static void
multi_process_io_udp (struct multi_context *m)
{
const unsigned int status = m->top.c2.event_set_status;
const unsigned int mpp_flags = m->top.c2.fast_io
? (MPP_CONDITIONAL_PRE_SELECT | MPP_CLOSE_ON_SIGNAL)
: (MPP_PRE_SELECT | MPP_CLOSE_ON_SIGNAL);
#ifdef MULTI_DEBUG_EVENT_LOOP
char buf[16];
buf[0] = 0;
if (status & SOCKET_READ)
strcat (buf, "SR/");
else if (status & SOCKET_WRITE)
strcat (buf, "SW/");
else if (status & TUN_READ)
strcat (buf, "TR/");
else if (status & TUN_WRITE)
strcat (buf, "TW/");
printf ("IO %s\n", buf);
#endif
#ifdef ENABLE_MANAGEMENT
if (status & (MANAGEMENT_READ|MANAGEMENT_WRITE))
{
ASSERT (management);
management_io (management);
}
#endif
/* UDP port ready to accept write */
if (status & SOCKET_WRITE)
{
multi_process_outgoing_link (m, mpp_flags);
}
/* TUN device ready to accept write */
else if (status & TUN_WRITE)
{
multi_process_outgoing_tun (m, mpp_flags);
}
/* Incoming data on UDP port */
else if (status & SOCKET_READ)
{
read_incoming_link (&m->top);
multi_release_io_lock (m);
if (!IS_SIG (&m->top))
multi_process_incoming_link (m, NULL, mpp_flags);
}
/* Incoming data on TUN device */
else if (status & TUN_READ)
{
read_incoming_tun (&m->top);
multi_release_io_lock (m);
if (!IS_SIG (&m->top))
multi_process_incoming_tun (m, mpp_flags);
}
}
/*
* Return the io_wait() flags appropriate for
* a point-to-multipoint tunnel.
*/
static inline unsigned int
p2mp_iow_flags (const struct multi_context *m)
{
unsigned int flags = IOW_WAIT_SIGNAL;
if (m->pending)
{
if (TUN_OUT (&m->pending->context))
flags |= IOW_TO_TUN;
if (LINK_OUT (&m->pending->context))
flags |= IOW_TO_LINK;
}
else if (mbuf_defined (m->mbuf))
flags |= IOW_MBUF;
else
flags |= IOW_READ;
return flags;
}
/**************************************************************************/
/**
* Main event loop for OpenVPN in UDP server mode.
* @ingroup eventloop
*
* This function implements OpenVPN's main event loop for UDP server mode.
* At this time, OpenVPN does not yet support multithreading. This
* function's name is therefore slightly misleading.
*
* @param top - Top-level context structure.
*/
static void
tunnel_server_udp_single_threaded (struct context *top)
{
struct multi_context multi;
top->mode = CM_TOP;
context_clear_2 (top);
/* initialize top-tunnel instance */
init_instance_handle_signals (top, top->es, CC_HARD_USR1_TO_HUP);
if (IS_SIG (top))
return;
/* initialize global multi_context object */
multi_init (&multi, top, false, MC_SINGLE_THREADED);
/* initialize our cloned top object */
multi_top_init (&multi, top, true);
/* initialize management interface */
init_management_callback_multi (&multi);
/* finished with initialization */
initialization_sequence_completed (top, ISC_SERVER); /* --mode server --proto udp */
/* per-packet event loop */
while (true)
{
perf_push (PERF_EVENT_LOOP);
/* set up and do the io_wait() */
multi_get_timeout (&multi, &multi.top.c2.timeval);
io_wait (&multi.top, p2mp_iow_flags (&multi));
MULTI_CHECK_SIG (&multi);
/* check on status of coarse timers */
multi_process_per_second_timers (&multi);
/* timeout? */
if (multi.top.c2.event_set_status == ES_TIMEOUT)
{
multi_process_timeout (&multi, MPP_PRE_SELECT|MPP_CLOSE_ON_SIGNAL);
}
else
{
/* process I/O */
multi_process_io_udp (&multi);
MULTI_CHECK_SIG (&multi);
}
perf_pop ();
}
/* shut down management interface */
uninit_management_callback_multi (&multi);
/* save ifconfig-pool */
multi_ifconfig_pool_persist (&multi, true);
/* tear down tunnel instance (unless --persist-tun) */
multi_uninit (&multi);
multi_top_free (&multi);
close_instance (top);
}
void
tunnel_server_udp (struct context *top)
{
tunnel_server_udp_single_threaded (top);
}
#endif
