diff options
Diffstat (limited to 'mtcp.c')
| -rw-r--r-- | mtcp.c | 718 |
1 files changed, 0 insertions, 718 deletions
@@ -1,718 +0,0 @@ -/* - * 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" - -/* - * TCP States - */ -#define TA_UNDEF 0 -#define TA_SOCKET_READ 1 -#define TA_SOCKET_READ_RESIDUAL 2 -#define TA_SOCKET_WRITE 3 -#define TA_SOCKET_WRITE_READY 4 -#define TA_SOCKET_WRITE_DEFERRED 5 -#define TA_TUN_READ 6 -#define TA_TUN_WRITE 7 -#define TA_INITIAL 8 -#define TA_TIMEOUT 9 -#define TA_TUN_WRITE_TIMEOUT 10 - -/* - * Special tags passed to event.[ch] functions - */ -#define MTCP_SOCKET ((void*)1) -#define MTCP_TUN ((void*)2) -#define MTCP_SIG ((void*)3) /* Only on Windows */ -#ifdef ENABLE_MANAGEMENT -# define MTCP_MANAGEMENT ((void*)4) -#endif - -#define MTCP_N ((void*)16) /* upper bound on MTCP_x */ - -struct ta_iow_flags -{ - unsigned int flags; - unsigned int ret; - unsigned int tun; - unsigned int sock; -}; - -static const char * -pract (int action) -{ - switch (action) - { - case TA_UNDEF: - return "TA_UNDEF"; - case TA_SOCKET_READ: - return "TA_SOCKET_READ"; - case TA_SOCKET_READ_RESIDUAL: - return "TA_SOCKET_READ_RESIDUAL"; - case TA_SOCKET_WRITE: - return "TA_SOCKET_WRITE"; - case TA_SOCKET_WRITE_READY: - return "TA_SOCKET_WRITE_READY"; - case TA_SOCKET_WRITE_DEFERRED: - return "TA_SOCKET_WRITE_DEFERRED"; - case TA_TUN_READ: - return "TA_TUN_READ"; - case TA_TUN_WRITE: - return "TA_TUN_WRITE"; - case TA_INITIAL: - return "TA_INITIAL"; - case TA_TIMEOUT: - return "TA_TIMEOUT"; - case TA_TUN_WRITE_TIMEOUT: - return "TA_TUN_WRITE_TIMEOUT"; - default: - return "?"; - } -} - -static struct multi_instance * -multi_create_instance_tcp (struct multi_context *m) -{ - struct gc_arena gc = gc_new (); - struct multi_instance *mi = NULL; - struct hash *hash = m->hash; - - mi = multi_create_instance (m, NULL); - if (mi) - { - struct hash_element *he; - const uint32_t hv = hash_value (hash, &mi->real); - struct hash_bucket *bucket = hash_bucket (hash, hv); - - he = hash_lookup_fast (hash, bucket, &mi->real, hv); - - if (he) - { - struct multi_instance *oldmi = (struct multi_instance *) he->value; - msg (D_MULTI_LOW, "MULTI TCP: new incoming client address matches existing client address -- new client takes precedence"); - oldmi->did_real_hash = false; - multi_close_instance (m, oldmi, false); - he->key = &mi->real; - he->value = mi; - } - else - hash_add_fast (hash, bucket, &mi->real, hv, mi); - - mi->did_real_hash = true; - } - -#ifdef ENABLE_DEBUG - if (mi) - dmsg (D_MULTI_DEBUG, "MULTI TCP: instance added: %s", mroute_addr_print (&mi->real, &gc)); - else - dmsg (D_MULTI_DEBUG, "MULTI TCP: new client instance failed"); -#endif - - gc_free (&gc); - ASSERT (!(mi && mi->halt)); - return mi; -} - -bool -multi_tcp_instance_specific_init (struct multi_context *m, struct multi_instance *mi) -{ - /* buffer for queued TCP socket output packets */ - mi->tcp_link_out_deferred = mbuf_init (m->top.options.n_bcast_buf); - - ASSERT (mi->context.c2.link_socket); - ASSERT (mi->context.c2.link_socket->info.lsa); - ASSERT (mi->context.c2.link_socket->mode == LS_MODE_TCP_ACCEPT_FROM); - if (!mroute_extract_openvpn_sockaddr (&mi->real, &mi->context.c2.link_socket->info.lsa->actual.dest, true)) - { - msg (D_MULTI_ERRORS, "MULTI TCP: TCP client address is undefined"); - return false; - } - return true; -} - -void -multi_tcp_instance_specific_free (struct multi_instance *mi) -{ - mbuf_free (mi->tcp_link_out_deferred); -} - -struct multi_tcp * -multi_tcp_init (int maxevents, int *maxclients) -{ - struct multi_tcp *mtcp; - const int extra_events = BASE_N_EVENTS; - - ASSERT (maxevents >= 1); - ASSERT (maxclients); - - ALLOC_OBJ_CLEAR (mtcp, struct multi_tcp); - mtcp->maxevents = maxevents + extra_events; - mtcp->es = event_set_init (&mtcp->maxevents, 0); - wait_signal (mtcp->es, MTCP_SIG); - ALLOC_ARRAY (mtcp->esr, struct event_set_return, mtcp->maxevents); - *maxclients = max_int (min_int (mtcp->maxevents - extra_events, *maxclients), 1); - msg (D_MULTI_LOW, "MULTI: TCP INIT maxclients=%d maxevents=%d", *maxclients, mtcp->maxevents); - return mtcp; -} - -void -multi_tcp_delete_event (struct multi_tcp *mtcp, event_t event) -{ - if (mtcp && mtcp->es) - event_del (mtcp->es, event); -} - -void -multi_tcp_free (struct multi_tcp *mtcp) -{ - if (mtcp) - { - event_free (mtcp->es); - if (mtcp->esr) - free (mtcp->esr); - free (mtcp); - } -} - -void -multi_tcp_dereference_instance (struct multi_tcp *mtcp, struct multi_instance *mi) -{ - struct link_socket *ls = mi->context.c2.link_socket; - if (ls && mi->socket_set_called) - event_del (mtcp->es, socket_event_handle (ls)); - mtcp->n_esr = 0; -} - -static inline void -multi_tcp_set_global_rw_flags (struct multi_context *m, struct multi_instance *mi) -{ - if (mi) - { - mi->socket_set_called = true; - socket_set (mi->context.c2.link_socket, - m->mtcp->es, - mbuf_defined (mi->tcp_link_out_deferred) ? EVENT_WRITE : EVENT_READ, - mi, - &mi->tcp_rwflags); - } -} - -static inline int -multi_tcp_wait (const struct context *c, - struct multi_tcp *mtcp) -{ - int status; - socket_set_listen_persistent (c->c2.link_socket, mtcp->es, MTCP_SOCKET); - tun_set (c->c1.tuntap, mtcp->es, EVENT_READ, MTCP_TUN, &mtcp->tun_rwflags); -#ifdef ENABLE_MANAGEMENT - if (management) - management_socket_set (management, mtcp->es, MTCP_MANAGEMENT, &mtcp->management_persist_flags); -#endif - status = event_wait (mtcp->es, &c->c2.timeval, mtcp->esr, mtcp->maxevents); - update_time (); - mtcp->n_esr = 0; - if (status > 0) - mtcp->n_esr = status; - return status; -} - -static inline struct context * -multi_tcp_context (struct multi_context *m, struct multi_instance *mi) -{ - if (mi) - return &mi->context; - else - return &m->top; -} - -static bool -multi_tcp_process_outgoing_link_ready (struct multi_context *m, struct multi_instance *mi, const unsigned int mpp_flags) -{ - struct mbuf_item item; - bool ret = true; - ASSERT (mi); - - /* extract from queue */ - if (mbuf_extract_item (mi->tcp_link_out_deferred, &item)) /* ciphertext IP packet */ - { - dmsg (D_MULTI_TCP, "MULTI TCP: transmitting previously deferred packet"); - - ASSERT (mi == item.instance); - mi->context.c2.to_link = item.buffer->buf; - ret = multi_process_outgoing_link_dowork (m, mi, mpp_flags); - if (!ret) - mi = NULL; - mbuf_free_buf (item.buffer); - } - return ret; -} - -static bool -multi_tcp_process_outgoing_link (struct multi_context *m, bool defer, const unsigned int mpp_flags) -{ - struct multi_instance *mi = multi_process_outgoing_link_pre (m); - bool ret = true; - - if (mi) - { - if (defer || mbuf_defined (mi->tcp_link_out_deferred)) - { - /* save to queue */ - struct buffer *buf = &mi->context.c2.to_link; - if (BLEN (buf) > 0) - { - struct mbuf_buffer *mb = mbuf_alloc_buf (buf); - struct mbuf_item item; - - set_prefix (mi); - dmsg (D_MULTI_TCP, "MULTI TCP: queuing deferred packet"); - item.buffer = mb; - item.instance = mi; - mbuf_add_item (mi->tcp_link_out_deferred, &item); - mbuf_free_buf (mb); - buf_reset (buf); - ret = multi_process_post (m, mi, mpp_flags); - if (!ret) - mi = NULL; - clear_prefix (); - } - } - else - { - ret = multi_process_outgoing_link_dowork (m, mi, mpp_flags); - if (!ret) - mi = NULL; - } - } - return ret; -} - -static int -multi_tcp_wait_lite (struct multi_context *m, struct multi_instance *mi, const int action, bool *tun_input_pending) -{ - struct context *c = multi_tcp_context (m, mi); - unsigned int looking_for = 0; - - dmsg (D_MULTI_DEBUG, "MULTI TCP: multi_tcp_wait_lite a=%s mi=" ptr_format, - pract(action), - (ptr_type)mi); - - tv_clear (&c->c2.timeval); /* ZERO-TIMEOUT */ - - switch (action) - { - case TA_TUN_READ: - looking_for = TUN_READ; - tun_input_pending = NULL; - io_wait (c, IOW_READ_TUN); - break; - case TA_SOCKET_READ: - looking_for = SOCKET_READ; - tun_input_pending = NULL; - io_wait (c, IOW_READ_LINK); - break; - case TA_TUN_WRITE: - looking_for = TUN_WRITE; - tun_input_pending = NULL; - c->c2.timeval.tv_sec = 1; /* For some reason, the Linux 2.2 TUN/TAP driver hits this timeout */ - perf_push (PERF_PROC_OUT_TUN_MTCP); - io_wait (c, IOW_TO_TUN); - perf_pop (); - break; - case TA_SOCKET_WRITE: - looking_for = SOCKET_WRITE; - io_wait (c, IOW_TO_LINK|IOW_READ_TUN_FORCE); - break; - default: - msg (M_FATAL, "MULTI TCP: multi_tcp_wait_lite, unhandled action=%d", action); - } - - if (tun_input_pending && (c->c2.event_set_status & TUN_READ)) - *tun_input_pending = true; - - if (c->c2.event_set_status & looking_for) - { - return action; - } - else - { - switch (action) - { - /* TCP socket output buffer is full */ - case TA_SOCKET_WRITE: - return TA_SOCKET_WRITE_DEFERRED; - - /* TUN device timed out on accepting write */ - case TA_TUN_WRITE: - return TA_TUN_WRITE_TIMEOUT; - } - - return TA_UNDEF; - } -} - -static struct multi_instance * -multi_tcp_dispatch (struct multi_context *m, struct multi_instance *mi, const int action) -{ - const unsigned int mpp_flags = MPP_PRE_SELECT|MPP_RECORD_TOUCH; - struct multi_instance *touched = mi; - m->mpp_touched = &touched; - - dmsg (D_MULTI_DEBUG, "MULTI TCP: multi_tcp_dispatch a=%s mi=" ptr_format, - pract(action), - (ptr_type)mi); - - switch (action) - { - case TA_TUN_READ: - read_incoming_tun (&m->top); - if (!IS_SIG (&m->top)) - multi_process_incoming_tun (m, mpp_flags); - break; - case TA_SOCKET_READ: - case TA_SOCKET_READ_RESIDUAL: - ASSERT (mi); - ASSERT (mi->context.c2.link_socket); - set_prefix (mi); - read_incoming_link (&mi->context); - clear_prefix (); - if (!IS_SIG (&mi->context)) - { - multi_process_incoming_link (m, mi, mpp_flags); - if (!IS_SIG (&mi->context)) - stream_buf_read_setup (mi->context.c2.link_socket); - } - break; - case TA_TIMEOUT: - multi_process_timeout (m, mpp_flags); - break; - case TA_TUN_WRITE: - multi_process_outgoing_tun (m, mpp_flags); - break; - case TA_TUN_WRITE_TIMEOUT: - multi_process_drop_outgoing_tun (m, mpp_flags); - break; - case TA_SOCKET_WRITE_READY: - ASSERT (mi); - multi_tcp_process_outgoing_link_ready (m, mi, mpp_flags); - break; - case TA_SOCKET_WRITE: - multi_tcp_process_outgoing_link (m, false, mpp_flags); - break; - case TA_SOCKET_WRITE_DEFERRED: - multi_tcp_process_outgoing_link (m, true, mpp_flags); - break; - case TA_INITIAL: - ASSERT (mi); - multi_tcp_set_global_rw_flags (m, mi); - multi_process_post (m, mi, mpp_flags); - break; - default: - msg (M_FATAL, "MULTI TCP: multi_tcp_dispatch, unhandled action=%d", action); - } - - m->mpp_touched = NULL; - return touched; -} - -int -multi_tcp_post (struct multi_context *m, struct multi_instance *mi, const int action) -{ - struct context *c = multi_tcp_context (m, mi); - int newaction = TA_UNDEF; - -# define MTP_NONE 0 -# define MTP_TUN_OUT (1<<0) -# define MTP_LINK_OUT (1<<1) - unsigned int flags = MTP_NONE; - - if (TUN_OUT(c)) - flags |= MTP_TUN_OUT; - if (LINK_OUT(c)) - flags |= MTP_LINK_OUT; - - switch (flags) - { - case MTP_TUN_OUT|MTP_LINK_OUT: - case MTP_TUN_OUT: - newaction = TA_TUN_WRITE; - break; - case MTP_LINK_OUT: - newaction = TA_SOCKET_WRITE; - break; - case MTP_NONE: - if (mi && socket_read_residual (c->c2.link_socket)) - newaction = TA_SOCKET_READ_RESIDUAL; - else - multi_tcp_set_global_rw_flags (m, mi); - break; - default: - { - struct gc_arena gc = gc_new (); - msg (M_FATAL, "MULTI TCP: multi_tcp_post bad state, mi=%s flags=%d", - multi_instance_string (mi, false, &gc), - flags); - gc_free (&gc); - break; - } - } - - dmsg (D_MULTI_DEBUG, "MULTI TCP: multi_tcp_post %s -> %s", - pract(action), - pract(newaction)); - - return newaction; -} - -static void -multi_tcp_action (struct multi_context *m, struct multi_instance *mi, int action, bool poll) -{ - bool tun_input_pending = false; - - do { - dmsg (D_MULTI_DEBUG, "MULTI TCP: multi_tcp_action a=%s p=%d", - pract(action), - poll); - - /* - * If TA_SOCKET_READ_RESIDUAL, it means we still have pending - * input packets which were read by a prior TCP recv. - * - * Otherwise do a "lite" wait, which means we wait with 0 timeout - * on I/O events only related to the current instance, not - * the big list of events. - * - * On our first pass, poll will be false because we already know - * that input is available, and to call io_wait would be redundant. - */ - if (poll && action != TA_SOCKET_READ_RESIDUAL) - { - const int orig_action = action; - action = multi_tcp_wait_lite (m, mi, action, &tun_input_pending); - if (action == TA_UNDEF) - msg (M_FATAL, "MULTI TCP: I/O wait required blocking in multi_tcp_action, action=%d", orig_action); - } - - /* - * Dispatch the action - */ - { - struct multi_instance *touched = multi_tcp_dispatch (m, mi, action); - - /* - * Signal received or TCP connection - * reset by peer? - */ - if (touched && IS_SIG (&touched->context)) - { - if (mi == touched) - mi = NULL; - multi_close_instance_on_signal (m, touched); - } - } - - /* - * If dispatch produced any pending output - * for a particular instance, point to - * that instance. - */ - if (m->pending) - mi = m->pending; - - /* - * Based on the effects of the action, - * such as generating pending output, - * possibly transition to a new action state. - */ - action = multi_tcp_post (m, mi, action); - - /* - * If we are finished processing the original action, - * check if we have any TUN input. If so, transition - * our action state to processing this input. - */ - if (tun_input_pending && action == TA_UNDEF) - { - action = TA_TUN_READ; - mi = NULL; - tun_input_pending = false; - poll = false; - } - else - poll = true; - - } while (action != TA_UNDEF); -} - -static void -multi_tcp_process_io (struct multi_context *m) -{ - struct multi_tcp *mtcp = m->mtcp; - int i; - - for (i = 0; i < mtcp->n_esr; ++i) - { - struct event_set_return *e = &mtcp->esr[i]; - - /* incoming data for instance? */ - if (e->arg >= MTCP_N) - { - struct multi_instance *mi = (struct multi_instance *) e->arg; - if (mi) - { - if (e->rwflags & EVENT_WRITE) - multi_tcp_action (m, mi, TA_SOCKET_WRITE_READY, false); - else if (e->rwflags & EVENT_READ) - multi_tcp_action (m, mi, TA_SOCKET_READ, false); - } - } - else - { -#ifdef ENABLE_MANAGEMENT - if (e->arg == MTCP_MANAGEMENT) - { - ASSERT (management); - management_io (management); - } - else -#endif - /* incoming data on TUN? */ - if (e->arg == MTCP_TUN) - { - if (e->rwflags & EVENT_WRITE) - multi_tcp_action (m, NULL, TA_TUN_WRITE, false); - else if (e->rwflags & EVENT_READ) - multi_tcp_action (m, NULL, TA_TUN_READ, false); - } - /* new incoming TCP client attempting to connect? */ - else if (e->arg == MTCP_SOCKET) - { - struct multi_instance *mi; - ASSERT (m->top.c2.link_socket); - socket_reset_listen_persistent (m->top.c2.link_socket); - mi = multi_create_instance_tcp (m); - if (mi) - multi_tcp_action (m, mi, TA_INITIAL, false); - } - /* signal received? */ - else if (e->arg == MTCP_SIG) - { - get_signal (&m->top.sig->signal_received); - } - } - if (IS_SIG (&m->top)) - break; - } - mtcp->n_esr = 0; - - /* - * Process queued mbuf packets destined for TCP socket - */ - { - struct multi_instance *mi; - while (!IS_SIG (&m->top) && (mi = mbuf_peek (m->mbuf)) != NULL) - { - multi_tcp_action (m, mi, TA_SOCKET_WRITE, true); - } - } -} - -/* - * Top level event loop for single-threaded operation. - * TCP mode. - */ -void -tunnel_server_tcp (struct context *top) -{ - struct multi_context multi; - int status; - - 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, true, 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 tcp-server */ - - /* per-packet event loop */ - while (true) - { - perf_push (PERF_EVENT_LOOP); - - /* wait on tun/socket list */ - multi_get_timeout (&multi, &multi.top.c2.timeval); - status = multi_tcp_wait (&multi.top, multi.mtcp); - MULTI_CHECK_SIG (&multi); - - /* check on status of coarse timers */ - multi_process_per_second_timers (&multi); - - /* timeout? */ - if (status > 0) - { - /* process the I/O which triggered select */ - multi_tcp_process_io (&multi); - MULTI_CHECK_SIG (&multi); - } - else if (status == 0) - { - multi_tcp_action (&multi, NULL, TA_TIMEOUT, false); - } - - 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); -} - -#endif |