Imported Upstream version 2.3_rc1

1 files changed, 582 insertions, 0 deletions

diff --git a/src/openvpn/multi.h b/src/openvpn/multi.h
new file mode 100644
index 0000000..2bc0c8a
--- /dev/null
+++ b/src/openvpn/multi.h
@@ -0,0 +1,582 @@
+/*
+ *  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
+ */
+
+/**
+ * @file Header file for server-mode related structures and functions.
+ */
+
+#ifndef MULTI_H
+#define MULTI_H
+
+#if P2MP_SERVER
+
+#include "init.h"
+#include "forward.h"
+#include "mroute.h"
+#include "mbuf.h"
+#include "list.h"
+#include "schedule.h"
+#include "pool.h"
+#include "mudp.h"
+#include "mtcp.h"
+#include "perf.h"
+
+/*
+ * Walk (don't run) through the routing table,
+ * deleting old entries, and possibly multi_instance
+ * structs as well which have been marked for deletion.
+ */
+struct multi_reap
+{
+  int bucket_base;
+  int buckets_per_pass;
+  time_t last_call;
+};
+
+
+/**
+ * Server-mode state structure for one single VPN tunnel.
+ *
+ * This structure is used by OpenVPN processes running in server-mode to
+ * store state information related to one single VPN tunnel.
+ *
+ * The @ref tunnel_state "Structure of VPN tunnel state storage" related
+ * page describes the role the structure plays when OpenVPN is running in
+ * server-mode.
+ */
+struct multi_instance {
+  struct schedule_entry se;    /* this must be the first element of the structure */
+  struct gc_arena gc;
+  bool defined;
+  bool halt;
+  int refcount;
+  int route_count;             /* number of routes (including cached routes) owned by this instance */
+  time_t created;               /**< Time at which a VPN tunnel instance
+                                 *   was created.  This parameter is set
+                                 *   by the \c multi_create_instance()
+                                 *   function. */
+  struct timeval wakeup;       /* absolute time */
+  struct mroute_addr real;      /**< External network address of the
+                                 *   remote peer. */
+  ifconfig_pool_handle vaddr_handle;
+  const char *msg_prefix;
+
+  /* queued outgoing data in Server/TCP mode */
+  unsigned int tcp_rwflags;
+  struct mbuf_set *tcp_link_out_deferred;
+  bool socket_set_called;
+
+  in_addr_t reporting_addr;       /* IP address shown in status listing */
+
+  bool did_open_context;
+  bool did_real_hash;
+  bool did_iter;
+#ifdef MANAGEMENT_DEF_AUTH
+  bool did_cid_hash;
+  struct buffer_list *cc_config;
+#endif
+  bool connection_established_flag;
+  bool did_iroutes;
+  int n_clients_delta; /* added to multi_context.n_clients when instance is closed */
+
+  struct context context;       /**< The context structure storing state
+                                 *   for this VPN tunnel. */
+};
+
+
+/**
+ * Main OpenVPN server state structure.
+ *
+ * This structure is used by OpenVPN processes running in server-mode to
+ * store all the VPN tunnel and process-wide state.
+ *
+ * The @ref tunnel_state "Structure of VPN tunnel state storage" related
+ * page describes the role the structure plays when OpenVPN is running in
+ * server-mode.
+ */
+struct multi_context {
+# define MC_UNDEF                      0
+# define MC_SINGLE_THREADED            (1<<0)
+# define MC_MULTI_THREADED_MASTER      (1<<1)
+# define MC_MULTI_THREADED_WORKER      (1<<2)
+# define MC_MULTI_THREADED_SCHEDULER   (1<<3)
+# define MC_WORK_THREAD                (MC_MULTI_THREADED_WORKER|MC_MULTI_THREADED_SCHEDULER)
+  int thread_mode;
+
+  struct hash *hash;            /**< VPN tunnel instances indexed by real
+                                 *   address of the remote peer. */
+  struct hash *vhash;           /**< VPN tunnel instances indexed by
+                                 *   virtual address of remote hosts. */
+  struct hash *iter;            /**< VPN tunnel instances indexed by real
+                                 *   address of the remote peer, optimized
+                                 *   for iteration. */
+  struct schedule *schedule;
+  struct mbuf_set *mbuf;        /**< Set of buffers for passing data
+                                 *   channel packets between VPN tunnel
+                                 *   instances. */
+  struct multi_tcp *mtcp;       /**< State specific to OpenVPN using TCP
+                                 *   as external transport. */
+  struct ifconfig_pool *ifconfig_pool;
+  struct frequency_limit *new_connection_limiter;
+  struct mroute_helper *route_helper;
+  struct multi_reap *reaper;
+  struct mroute_addr local;
+  bool enable_c2c;
+  int max_clients;
+  int tcp_queue_limit;
+  int status_file_version;
+  int n_clients; /* current number of authenticated clients */
+
+#ifdef MANAGEMENT_DEF_AUTH
+  struct hash *cid_hash;
+  unsigned long cid_counter;
+#endif
+
+  struct multi_instance *pending;
+  struct multi_instance *earliest_wakeup;
+  struct multi_instance **mpp_touched;
+  struct context_buffers *context_buffers;
+  time_t per_second_trigger;
+
+  struct context top;           /**< Storage structure for process-wide
+                                 *   configuration. */
+
+  /*
+   * Timer object for stale route check
+   */
+  struct event_timeout stale_routes_check_et;
+};
+
+/*
+ * Host route
+ */
+struct multi_route
+{
+  struct mroute_addr addr;
+  struct multi_instance *instance;
+
+# define MULTI_ROUTE_CACHE   (1<<0)
+# define MULTI_ROUTE_AGEABLE (1<<1)
+  unsigned int flags;
+
+  unsigned int cache_generation;
+  time_t last_reference;
+};
+
+
+/**************************************************************************/
+/**
+ * Main event loop for OpenVPN in server mode.
+ * @ingroup eventloop
+ *
+ * This function calls the appropriate main event loop function depending
+ * on the transport protocol used:
+ *  - \c tunnel_server_udp()
+ *  - \c tunnel_server_tcp()
+ *
+ * @param top          - Top-level context structure.
+ */
+void tunnel_server (struct context *top);
+
+
+const char *multi_instance_string (const struct multi_instance *mi, bool null, struct gc_arena *gc);
+
+/*
+ * Called by mtcp.c, mudp.c, or other (to be written) protocol drivers
+ */
+
+void multi_init (struct multi_context *m, struct context *t, bool tcp_mode, int thread_mode);
+void multi_uninit (struct multi_context *m);
+
+void multi_top_init (struct multi_context *m, const struct context *top, const bool alloc_buffers);
+void multi_top_free (struct multi_context *m);
+
+struct multi_instance *multi_create_instance (struct multi_context *m, const struct mroute_addr *real);
+void multi_close_instance (struct multi_context *m, struct multi_instance *mi, bool shutdown);
+
+bool multi_process_timeout (struct multi_context *m, const unsigned int mpp_flags);
+
+#define MPP_PRE_SELECT             (1<<0)
+#define MPP_CONDITIONAL_PRE_SELECT (1<<1)
+#define MPP_CLOSE_ON_SIGNAL        (1<<2)
+#define MPP_RECORD_TOUCH           (1<<3)
+
+
+/**************************************************************************/
+/**
+ * Perform postprocessing of a VPN tunnel instance.
+ *
+ * After some VPN tunnel activity has taken place, the VPN tunnel's state
+ * may need updating and some follow-up action may be required.  This
+ * function controls the necessary postprocessing.  It is called by many
+ * other functions that handle VPN tunnel related activity, such as \c
+ * multi_process_incoming_link(), \c multi_process_outgoing_link(), \c
+ * multi_process_incoming_tun(), \c multi_process_outgoing_tun(), and \c
+ * multi_process_timeout(), among others.
+ *
+ * @param m            - The single \c multi_context structure.
+ * @param mi           - The \c multi_instance of the VPN tunnel to be
+ *                       postprocessed.
+ * @param flags        - Fast I/O optimization flags.
+ *
+ * @return
+ *  - True, if the VPN tunnel instance \a mi was not closed due to a
+ *    signal during processing.
+ *  - False, if the VPN tunnel instance \a mi was closed.
+ */
+bool multi_process_post (struct multi_context *m, struct multi_instance *mi, const unsigned int flags);
+
+
+/**************************************************************************/
+/**
+ * Demultiplex and process a packet received over the external network
+ * interface.
+ * @ingroup external_multiplexer
+ *
+ * This function determines which VPN tunnel instance the incoming packet
+ * is associated with, and then calls \c process_incoming_link() to handle
+ * it.  Afterwards, if the packet is destined for a broadcast/multicast
+ * address or a remote host reachable through a different VPN tunnel, this
+ * function takes care of sending it they are.
+ *
+ * @note This function is only used by OpenVPN processes which are running
+ *     in server mode, and can therefore sustain multiple active VPN
+ *     tunnels.
+ *
+ * @param m            - The single \c multi_context structure.
+ * @param instance     - The VPN tunnel state structure associated with
+ *                       the incoming packet, if known, as is the case
+ *                       when using TCP transport. Otherwise NULL, as is
+ *                       the case when using UDP transport.
+ * @param mpp_flags    - Fast I/O optimization flags.
+ */
+bool multi_process_incoming_link (struct multi_context *m, struct multi_instance *instance, const unsigned int mpp_flags);
+
+
+/**
+ * Determine the destination VPN tunnel of a packet received over the
+ * virtual tun/tap network interface and then process it accordingly.
+ * @ingroup internal_multiplexer
+ *
+ * This function determines which VPN tunnel instance the packet is
+ * destined for, and then calls \c process_outgoing_tun() to handle it.
+ *
+ * @note This function is only used by OpenVPN processes which are running
+ *     in server mode, and can therefore sustain multiple active VPN
+ *     tunnels.
+ *
+ * @param m            - The single \c multi_context structure.
+ * @param mpp_flags    - Fast I/O optimization flags.
+ */
+bool multi_process_incoming_tun (struct multi_context *m, const unsigned int mpp_flags);
+
+
+void multi_process_drop_outgoing_tun (struct multi_context *m, const unsigned int mpp_flags);
+
+void multi_print_status (struct multi_context *m, struct status_output *so, const int version);
+
+struct multi_instance *multi_get_queue (struct mbuf_set *ms);
+
+void multi_add_mbuf (struct multi_context *m,
+		     struct multi_instance *mi,
+		     struct mbuf_buffer *mb);
+
+void multi_ifconfig_pool_persist (struct multi_context *m, bool force);
+
+bool multi_process_signal (struct multi_context *m);
+
+void multi_close_instance_on_signal (struct multi_context *m, struct multi_instance *mi);
+
+void init_management_callback_multi (struct multi_context *m);
+void uninit_management_callback_multi (struct multi_context *m);
+
+/*
+ * Return true if our output queue is not full
+ */
+static inline bool
+multi_output_queue_ready (const struct multi_context *m,
+			  const struct multi_instance *mi)
+{
+  if (mi->tcp_link_out_deferred)
+    return mbuf_len (mi->tcp_link_out_deferred) <= m->tcp_queue_limit;
+  else
+    return true;
+}
+
+/*
+ * Determine which instance has pending output
+ * and prepare the output for sending in
+ * the to_link buffer.
+ */
+static inline struct multi_instance *
+multi_process_outgoing_link_pre (struct multi_context *m)
+{
+  struct multi_instance *mi = NULL;
+
+  if (m->pending)
+    mi = m->pending;
+  else if (mbuf_defined (m->mbuf))
+    mi = multi_get_queue (m->mbuf);
+  return mi;
+}
+
+/*
+ * Per-client route quota management
+ */
+
+void route_quota_exceeded (const struct multi_context *m, const struct multi_instance *mi);
+
+static inline void
+route_quota_inc (struct multi_instance *mi)
+{
+  ++mi->route_count;
+}
+
+static inline void
+route_quota_dec (struct multi_instance *mi)
+{
+  --mi->route_count;
+}
+
+/* can we add a new route? */
+static inline bool
+route_quota_test (const struct multi_context *m, const struct multi_instance *mi)
+{
+  if (mi->route_count >= mi->context.options.max_routes_per_client)
+    {
+      route_quota_exceeded (m, mi);
+      return false;
+    }
+  else
+    return true;
+}
+
+/*
+ * Instance reference counting
+ */
+
+static inline void
+multi_instance_inc_refcount (struct multi_instance *mi)
+{
+  ++mi->refcount;
+}
+
+static inline void
+multi_instance_dec_refcount (struct multi_instance *mi)
+{
+  if (--mi->refcount <= 0)
+    {
+      gc_free (&mi->gc);
+      free (mi);
+    }
+}
+
+static inline void
+multi_route_del (struct multi_route *route)
+{
+  struct multi_instance *mi = route->instance;
+  route_quota_dec (mi);
+  multi_instance_dec_refcount (mi);
+  free (route);
+}
+
+static inline bool
+multi_route_defined (const struct multi_context *m,
+		     const struct multi_route *r)
+{
+  if (r->instance->halt)
+    return false;
+  else if ((r->flags & MULTI_ROUTE_CACHE)
+	   && r->cache_generation != m->route_helper->cache_generation)
+    return false;
+  else if ((r->flags & MULTI_ROUTE_AGEABLE)
+	   && r->last_reference + m->route_helper->ageable_ttl_secs < now)
+    return false;
+  else
+    return true;
+}
+
+/*
+ * Set a msg() function prefix with our current client instance ID.
+ */
+
+static inline void
+set_prefix (struct multi_instance *mi)
+{
+#ifdef MULTI_DEBUG_EVENT_LOOP
+  if (mi->msg_prefix)
+    printf ("[%s]\n", mi->msg_prefix);
+#endif
+  msg_set_prefix (mi->msg_prefix);
+}
+
+static inline void
+clear_prefix (void)
+{
+#ifdef MULTI_DEBUG_EVENT_LOOP
+  printf ("[NULL]\n");
+#endif
+  msg_set_prefix (NULL);
+}
+
+/*
+ * Instance Reaper
+ *
+ * Reaper constants.  The reaper is the process where the virtual address
+ * and virtual route hash table is scanned for dead entries which are
+ * then removed.  The hash table could potentially be quite large, so we
+ * don't want to reap in a single pass.
+ */
+
+#define REAP_MAX_WAKEUP   10  /* Do reap pass at least once per n seconds */
+#define REAP_DIVISOR     256  /* How many passes to cover whole hash table */
+#define REAP_MIN          16  /* Minimum number of buckets per pass */
+#define REAP_MAX        1024  /* Maximum number of buckets per pass */
+
+/*
+ * Mark a cached host route for deletion after this
+ * many seconds without any references.
+ */
+#define MULTI_CACHE_ROUTE_TTL 60
+
+static inline void
+multi_reap_process (const struct multi_context *m)
+{
+  void multi_reap_process_dowork (const struct multi_context *m);
+  if (m->reaper->last_call != now)
+    multi_reap_process_dowork (m);
+}
+
+static inline void
+multi_process_per_second_timers (struct multi_context *m)
+{
+  if (m->per_second_trigger != now)
+    {
+      void multi_process_per_second_timers_dowork (struct multi_context *m);
+      multi_process_per_second_timers_dowork (m);
+      m->per_second_trigger = now;
+    }
+}
+
+/*
+ * Compute earliest timeout expiry from the set of
+ * all instances.  Output:
+ *
+ * m->earliest_wakeup : instance needing the earliest service.
+ * dest               : earliest timeout as a delta in relation
+ *                      to current time.
+ */
+static inline void
+multi_get_timeout (struct multi_context *m, struct timeval *dest)
+{
+  struct timeval tv, current;
+
+  CLEAR (tv);
+  m->earliest_wakeup = (struct multi_instance *) schedule_get_earliest_wakeup (m->schedule, &tv);
+  if (m->earliest_wakeup)
+    {
+      ASSERT (!openvpn_gettimeofday (&current, NULL));
+      tv_delta (dest, &current, &tv);
+      if (dest->tv_sec >= REAP_MAX_WAKEUP)
+	{
+	  m->earliest_wakeup = NULL;
+	  dest->tv_sec = REAP_MAX_WAKEUP;
+	  dest->tv_usec = 0;
+	}
+    }
+  else
+    {
+      dest->tv_sec = REAP_MAX_WAKEUP;
+      dest->tv_usec = 0;
+    }
+}
+
+
+/**
+ * Send a packet over the virtual tun/tap network interface to its locally
+ * reachable destination.
+ * @ingroup internal_multiplexer
+ *
+ * This function calls \c process_outgoing_tun() to perform the actual
+ * sending of the packet.  Afterwards, it calls \c multi_process_post() to
+ * perform server-mode postprocessing.
+ *
+ * @param m            - The single \c multi_context structure.
+ * @param mpp_flags    - Fast I/O optimization flags.
+ *
+ * @return
+ *  - True, if the \c multi_instance associated with the packet sent was
+ *    not closed due to a signal during processing.
+ *  - Falls, if the \c multi_instance was closed.
+ */
+static inline bool
+multi_process_outgoing_tun (struct multi_context *m, const unsigned int mpp_flags)
+{
+  struct multi_instance *mi = m->pending;
+  bool ret = true;
+
+  ASSERT (mi);
+#ifdef MULTI_DEBUG_EVENT_LOOP
+  printf ("%s -> TUN len=%d\n",
+	  id(mi),
+	  mi->context.c2.to_tun.len);
+#endif
+  set_prefix (mi);
+  process_outgoing_tun (&mi->context);
+  ret = multi_process_post (m, mi, mpp_flags);
+  clear_prefix ();
+  return ret;
+}
+
+
+
+static inline bool
+multi_process_outgoing_link_dowork (struct multi_context *m, struct multi_instance *mi, const unsigned int mpp_flags)
+{
+  bool ret = true;
+  set_prefix (mi);
+  process_outgoing_link (&mi->context);
+  ret = multi_process_post (m, mi, mpp_flags);
+  clear_prefix ();
+  return ret;
+}
+
+/*
+ * Check for signals.
+ */
+#define MULTI_CHECK_SIG(m) EVENT_LOOP_CHECK_SIGNAL (&(m)->top, multi_process_signal, (m))
+
+static inline void
+multi_set_pending (struct multi_context *m, struct multi_instance *mi)
+{
+  m->pending = mi;
+}
+
+static inline void
+multi_release_io_lock (struct multi_context *m)
+{
+}
+
+#endif /* P2MP_SERVER */
+#endif /* MULTI_H */