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-rw-r--r--mudp.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/mudp.c b/mudp.c
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+++ b/mudp.c
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+/*
+ * 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) 2002-2005 OpenVPN Solutions LLC <info@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
+ */
+
+#ifdef WIN32
+#include "config-win32.h"
+#else
+#include "config.h"
+#endif
+
+#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_sockaddr_in (&real, &m->top.c2.from, true))
+ {
+ struct hash_element *he;
+ const uint32_t hv = hash_value (hash, &real);
+ struct hash_bucket *bucket = hash_bucket (hash, hv);
+
+ hash_bucket_lock (bucket);
+ 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));
+ }
+ }
+ }
+
+ hash_bucket_unlock (bucket);
+
+#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;
+}
+
+/*
+ * Top level event loop for single-threaded operation.
+ * UDP mode.
+ */
+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