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a032fcb7bc
openvpn/forward.c
james 838911cc42 Added optional minimum-number-of-bytes 
parameter to --inactive directive.


git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@1036 e7ae566f-a301-0410-adde-c780ea21d3b5
2006-06-11 04:22:11 +00:00

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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"
#include "forward.h"
#include "init.h"
#include "push.h"
#include "gremlin.h"
#include "mss.h"
#include "event.h"
#include "ps.h"
#include "memdbg.h"
#include "forward-inline.h"
#include "occ-inline.h"
#include "ping-inline.h"
/* show event wait debugging info */
#ifdef ENABLE_DEBUG
const char *
wait_status_string (struct context *c, struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (64, gc);
buf_printf (&out, "I/O WAIT %s|%s|%s|%s %s",
tun_stat (c->c1.tuntap, EVENT_READ, gc),
tun_stat (c->c1.tuntap, EVENT_WRITE, gc),
socket_stat (c->c2.link_socket, EVENT_READ, gc),
socket_stat (c->c2.link_socket, EVENT_WRITE, gc),
tv_string (&c->c2.timeval, gc));
return BSTR (&out);
}
void
show_wait_status (struct context *c)
{
struct gc_arena gc = gc_new ();
dmsg (D_EVENT_WAIT, "%s", wait_status_string (c, &gc));
gc_free (&gc);
}
#endif
/*
* In TLS mode, let TLS level respond to any control-channel
* packets which were received, or prepare any packets for
* transmission.
*
* tmp_int is purely an optimization that allows us to call
* tls_multi_process less frequently when there's not much
* traffic on the control-channel.
*
*/
#if defined(USE_CRYPTO) && defined(USE_SSL)
void
check_tls_dowork (struct context *c)
{
interval_t wakeup = BIG_TIMEOUT;
if (interval_test (&c->c2.tmp_int))
{
if (tls_multi_process
(c->c2.tls_multi, &c->c2.to_link, &c->c2.to_link_addr,
get_link_socket_info (c), &wakeup))
{
update_time ();
interval_action (&c->c2.tmp_int);
}
interval_future_trigger (&c->c2.tmp_int, wakeup);
}
interval_schedule_wakeup (&c->c2.tmp_int, &wakeup);
if (wakeup)
context_reschedule_sec (c, wakeup);
}
#endif
#if defined(USE_CRYPTO) && defined(USE_SSL)
void
check_tls_errors_co (struct context *c)
{
msg (D_STREAM_ERRORS, "Fatal TLS error (check_tls_errors_co), restarting");
c->sig->signal_received = c->c2.tls_exit_signal; /* SOFT-SIGUSR1 -- TLS error */
c->sig->signal_text = "tls-error";
}
void
check_tls_errors_nco (struct context *c)
{
c->sig->signal_received = c->c2.tls_exit_signal; /* SOFT-SIGUSR1 -- TLS error */
c->sig->signal_text = "tls-error";
}
#endif
#if P2MP
/*
* Handle incoming configuration
* messages on the control channel.
*/
void
check_incoming_control_channel_dowork (struct context *c)
{
const int len = tls_test_payload_len (c->c2.tls_multi);
if (len)
{
struct gc_arena gc = gc_new ();
struct buffer buf = alloc_buf_gc (len, &gc);
if (tls_rec_payload (c->c2.tls_multi, &buf))
{
/* force null termination of message */
buf_null_terminate (&buf);
/* enforce character class restrictions */
string_mod (BSTR (&buf), CC_PRINT, CC_CRLF, 0);
if (buf_string_match_head_str (&buf, "AUTH_FAILED"))
receive_auth_failed (c, &buf);
else if (buf_string_match_head_str (&buf, "PUSH_"))
incoming_push_message (c, &buf);
else
msg (D_PUSH_ERRORS, "WARNING: Received unknown control message: %s", BSTR (&buf));
}
else
{
msg (D_PUSH_ERRORS, "WARNING: Receive control message failed");
}
gc_free (&gc);
}
}
/*
* Periodically resend PUSH_REQUEST until PUSH message received
*/
void
check_push_request_dowork (struct context *c)
{
send_push_request (c);
}
#endif
/*
* Things that need to happen immediately after connection initiation should go here.
*/
void
check_connection_established_dowork (struct context *c)
{
if (event_timeout_trigger (&c->c2.wait_for_connect, &c->c2.timeval, ETT_DEFAULT))
{
if (CONNECTION_ESTABLISHED (c))
{
#if P2MP
/* if --pull was specified, send a push request to server */
if (c->c2.tls_multi && c->options.pull)
{
#ifdef ENABLE_MANAGEMENT
if (management)
{
management_set_state (management,
OPENVPN_STATE_GET_CONFIG,
NULL,
0,
0);
}
#endif
send_push_request (c);
/* if no reply, try again in 5 sec */
event_timeout_init (&c->c2.push_request_interval, 5, now);
reset_coarse_timers (c);
}
else
#endif
{
do_up (c, false, 0);
}
event_timeout_clear (&c->c2.wait_for_connect);
}
}
}
/*
* Send a string to remote over the TLS control channel.
* Used for push/pull messages, passing username/password,
* etc.
*/
bool
send_control_channel_string (struct context *c, const char *str, int msglevel)
{
#if defined(USE_CRYPTO) && defined(USE_SSL)
if (c->c2.tls_multi) {
bool stat;
/* buffered cleartext write onto TLS control channel */
stat = tls_send_payload (c->c2.tls_multi, (uint8_t*) str, strlen (str) + 1);
/* reschedule tls_multi_process */
interval_action (&c->c2.tmp_int);
context_immediate_reschedule (c); /* ZERO-TIMEOUT */
msg (msglevel, "SENT CONTROL [%s]: '%s' (status=%d)",
tls_common_name (c->c2.tls_multi, false),
str,
(int) stat);
return stat;
}
#endif
return true;
}
/*
* Add routes.
*/
static void
check_add_routes_action (struct context *c, const bool errors)
{
do_route (&c->options, c->c1.route_list, c->c1.tuntap, c->plugins, c->c2.es);
update_time ();
event_timeout_clear (&c->c2.route_wakeup);
event_timeout_clear (&c->c2.route_wakeup_expire);
initialization_sequence_completed (c, errors ? ISC_ERRORS : 0); /* client/p2p --route-delay was defined */
}
void
check_add_routes_dowork (struct context *c)
{
if (test_routes (c->c1.route_list, c->c1.tuntap))
{
check_add_routes_action (c, false);
}
else if (event_timeout_trigger (&c->c2.route_wakeup_expire, &c->c2.timeval, ETT_DEFAULT))
{
check_add_routes_action (c, true);
}
else
{
msg (D_ROUTE, "Route: Waiting for TUN/TAP interface to come up...");
if (c->c1.tuntap)
{
if (!tun_standby (c->c1.tuntap))
{
c->sig->signal_received = SIGHUP;
c->sig->signal_text = "ip-fail";
c->persist.restart_sleep_seconds = 10;
#ifdef WIN32
show_routes (M_INFO|M_NOPREFIX);
show_adapters (M_INFO|M_NOPREFIX);
#endif
}
}
update_time ();
if (c->c2.route_wakeup.n != 1)
event_timeout_init (&c->c2.route_wakeup, 1, now);
event_timeout_reset (&c->c2.ping_rec_interval);
}
}
/*
* Should we exit due to inactivity timeout?
*/
void
check_inactivity_timeout_dowork (struct context *c)
{
msg (M_INFO, "Inactivity timeout (--inactive), exiting");
c->sig->signal_received = SIGTERM;
c->sig->signal_text = "inactive";
}
#if P2MP
/*
* Schedule a SIGTERM n_seconds from now.
*/
void
schedule_exit (struct context *c, const int n_seconds)
{
tls_set_single_session (c->c2.tls_multi);
update_time ();
reset_coarse_timers (c);
event_timeout_init (&c->c2.scheduled_exit, n_seconds, now);
msg (D_SCHED_EXIT, "Delayed exit in %d seconds", n_seconds);
}
/*
* Scheduled exit?
*/
void
check_scheduled_exit_dowork (struct context *c)
{
c->sig->signal_received = SIGTERM;
c->sig->signal_text = "delayed-exit";
}
#endif
/*
* Should we write timer-triggered status file.
*/
void
check_status_file_dowork (struct context *c)
{
if (c->c1.status_output)
print_status (c, c->c1.status_output);
}
#ifdef ENABLE_FRAGMENT
/*
* Should we deliver a datagram fragment to remote?
*/
void
check_fragment_dowork (struct context *c)
{
struct link_socket_info *lsi = get_link_socket_info (c);
/* OS MTU Hint? */
if (lsi->mtu_changed && c->c2.ipv4_tun)
{
frame_adjust_path_mtu (&c->c2.frame_fragment, c->c2.link_socket->mtu,
c->options.proto);
lsi->mtu_changed = false;
}
if (fragment_outgoing_defined (c->c2.fragment))
{
if (!c->c2.to_link.len)
{
/* encrypt a fragment for output to TCP/UDP port */
ASSERT (fragment_ready_to_send (c->c2.fragment, &c->c2.buf, &c->c2.frame_fragment));
encrypt_sign (c, false);
}
}
fragment_housekeeping (c->c2.fragment, &c->c2.frame_fragment, &c->c2.timeval);
}
#endif
/*
* Buffer reallocation, for use with null encryption.
*/
static inline void
buffer_turnover (const uint8_t *orig_buf, struct buffer *dest_stub, struct buffer *src_stub, struct buffer *storage)
{
if (orig_buf == src_stub->data && src_stub->data != storage->data)
{
buf_assign (storage, src_stub);
*dest_stub = *storage;
}
else
{
*dest_stub = *src_stub;
}
}
/*
* Compress, fragment, encrypt and HMAC-sign an outgoing packet.
* Input: c->c2.buf
* Output: c->c2.to_link
*/
void
encrypt_sign (struct context *c, bool comp_frag)
{
struct context_buffers *b = c->c2.buffers;
const uint8_t *orig_buf = c->c2.buf.data;
#if P2MP_SERVER
/*
* Drop non-TLS outgoing packet if client-connect script/plugin
* has not yet succeeded.
*/
if (c->c2.context_auth != CAS_SUCCEEDED)
c->c2.buf.len = 0;
#endif
if (comp_frag)
{
#ifdef USE_LZO
/* Compress the packet. */
if (lzo_defined (&c->c2.lzo_compwork))
lzo_compress (&c->c2.buf, b->lzo_compress_buf, &c->c2.lzo_compwork, &c->c2.frame);
#endif
#ifdef ENABLE_FRAGMENT
if (c->c2.fragment)
fragment_outgoing (c->c2.fragment, &c->c2.buf, &c->c2.frame_fragment);
#endif
}
#ifdef USE_CRYPTO
#ifdef USE_SSL
/*
* If TLS mode, get the key we will use to encrypt
* the packet.
*/
if (c->c2.tls_multi)
{
/*tls_mutex_lock (c->c2.tls_multi);*/
tls_pre_encrypt (c->c2.tls_multi, &c->c2.buf, &c->c2.crypto_options);
}
#endif
/*
* Encrypt the packet and write an optional
* HMAC signature.
*/
openvpn_encrypt (&c->c2.buf, b->encrypt_buf, &c->c2.crypto_options, &c->c2.frame);
#endif
/*
* Get the address we will be sending the packet to.
*/
link_socket_get_outgoing_addr (&c->c2.buf, get_link_socket_info (c),
&c->c2.to_link_addr);
#ifdef USE_CRYPTO
#ifdef USE_SSL
/*
* In TLS mode, prepend the appropriate one-byte opcode
* to the packet which identifies it as a data channel
* packet and gives the low-permutation version of
* the key-id to the recipient so it knows which
* decrypt key to use.
*/
if (c->c2.tls_multi)
{
tls_post_encrypt (c->c2.tls_multi, &c->c2.buf);
/*tls_mutex_unlock (c->c2.tls_multi);*/
}
#endif
#endif
/* if null encryption, copy result to read_tun_buf */
buffer_turnover (orig_buf, &c->c2.to_link, &c->c2.buf, &b->read_tun_buf);
}
/*
* Coarse timers work to 1 second resolution.
*/
static void
process_coarse_timers (struct context *c)
{
#ifdef USE_CRYPTO
/* flush current packet-id to file once per 60
seconds if --replay-persist was specified */
check_packet_id_persist_flush (c);
#endif
/* should we update status file? */
check_status_file (c);
/* process connection establishment items */
check_connection_established (c);
#if P2MP
/* see if we should send a push_request in response to --pull */
check_push_request (c);
#endif
/* process --route options */
check_add_routes (c);
/* possibly exit due to --inactive */
check_inactivity_timeout (c);
if (c->sig->signal_received)
return;
/* restart if ping not received */
check_ping_restart (c);
if (c->sig->signal_received)
return;
#if P2MP
check_scheduled_exit (c);
if (c->sig->signal_received)
return;
#endif
#ifdef ENABLE_OCC
/* Should we send an OCC_REQUEST message? */
check_send_occ_req (c);
/* Should we send an MTU load test? */
check_send_occ_load_test (c);
/* Should we send an OCC_EXIT message to remote? */
if (c->c2.explicit_exit_notification_time_wait)
process_explicit_exit_notification_timer_wakeup (c);
#endif
/* Should we ping the remote? */
check_ping_send (c);
}
static void
check_coarse_timers_dowork (struct context *c)
{
const struct timeval save = c->c2.timeval;
c->c2.timeval.tv_sec = BIG_TIMEOUT;
c->c2.timeval.tv_usec = 0;
process_coarse_timers (c);
c->c2.coarse_timer_wakeup = now + c->c2.timeval.tv_sec;
dmsg (D_INTERVAL, "TIMER: coarse timer wakeup %d seconds", (int) c->c2.timeval.tv_sec);
/* Is the coarse timeout NOT the earliest one? */
if (c->c2.timeval.tv_sec > save.tv_sec)
c->c2.timeval = save;
}
static inline void
check_coarse_timers (struct context *c)
{
const time_t local_now = now;
if (local_now >= c->c2.coarse_timer_wakeup)
check_coarse_timers_dowork (c);
else
context_reschedule_sec (c, c->c2.coarse_timer_wakeup - local_now);
}
static void
check_timeout_random_component_dowork (struct context *c)
{
const int update_interval = 10; /* seconds */
c->c2.update_timeout_random_component = now + update_interval;
c->c2.timeout_random_component.tv_usec = (time_t) get_random () & 0x0003FFFF;
c->c2.timeout_random_component.tv_sec = 0;
dmsg (D_INTERVAL, "RANDOM USEC=%d", (int) c->c2.timeout_random_component.tv_usec);
}
static inline void
check_timeout_random_component (struct context *c)
{
if (now >= c->c2.update_timeout_random_component)
check_timeout_random_component_dowork (c);
if (c->c2.timeval.tv_sec >= 1)
tv_add (&c->c2.timeval, &c->c2.timeout_random_component);
}
#ifdef ENABLE_SOCKS
/*
* Handle addition and removal of the 10-byte Socks5 header
* in UDP packets.
*/
static inline void
socks_postprocess_incoming_link (struct context *c)
{
if (c->c2.link_socket->socks_proxy && c->c2.link_socket->info.proto == PROTO_UDPv4)
socks_process_incoming_udp (&c->c2.buf, &c->c2.from);
}
static inline void
socks_preprocess_outgoing_link (struct context *c,
struct link_socket_actual **to_addr,
int *size_delta)
{
if (c->c2.link_socket->socks_proxy && c->c2.link_socket->info.proto == PROTO_UDPv4)
{
*size_delta += socks_process_outgoing_udp (&c->c2.to_link, c->c2.to_link_addr);
*to_addr = &c->c2.link_socket->socks_relay;
}
}
/* undo effect of socks_preprocess_outgoing_link */
static inline void
link_socket_write_post_size_adjust (int *size,
int size_delta,
struct buffer *buf)
{
if (size_delta > 0 && *size > size_delta)
{
*size -= size_delta;
if (!buf_advance (buf, size_delta))
*size = 0;
}
}
#endif
/*
* Output: c->c2.buf
*/
void
read_incoming_link (struct context *c)
{
/*
* Set up for recvfrom call to read datagram
* sent to our TCP/UDP port.
*/
int status;
/*ASSERT (!c->c2.to_tun.len);*/
perf_push (PERF_READ_IN_LINK);
c->c2.buf = c->c2.buffers->read_link_buf;
ASSERT (buf_init (&c->c2.buf, FRAME_HEADROOM_ADJ (&c->c2.frame, FRAME_HEADROOM_MARKER_READ_LINK)));
status = link_socket_read (c->c2.link_socket,
&c->c2.buf,
MAX_RW_SIZE_LINK (&c->c2.frame),
&c->c2.from);
if (socket_connection_reset (c->c2.link_socket, status))
{
#if PORT_SHARE
if (port_share && socket_foreign_protocol_detected (c->c2.link_socket))
{
const struct buffer *fbuf = socket_foreign_protocol_head (c->c2.link_socket);
const int sd = socket_foreign_protocol_sd (c->c2.link_socket);
port_share_redirect (port_share, fbuf, sd);
c->sig->signal_received = SIGTERM;
c->sig->signal_text = "port-share-redirect";
}
else
#endif
{
/* received a disconnect from a connection-oriented protocol */
if (c->options.inetd)
{
c->sig->signal_received = SIGTERM;
msg (D_STREAM_ERRORS, "Connection reset, inetd/xinetd exit [%d]", status);
}
else
{
c->sig->signal_received = SIGUSR1; /* SOFT-SIGUSR1 -- TCP connection reset */
msg (D_STREAM_ERRORS, "Connection reset, restarting [%d]", status);
}
c->sig->signal_text = "connection-reset";
}
perf_pop ();
return;
}
/* check recvfrom status */
check_status (status, "read", c->c2.link_socket, NULL);
#ifdef ENABLE_SOCKS
/* Remove socks header if applicable */
socks_postprocess_incoming_link (c);
#endif
perf_pop ();
}
/*
* Input: c->c2.buf
* Output: c->c2.to_tun
*/
void
process_incoming_link (struct context *c)
{
struct gc_arena gc = gc_new ();
bool decrypt_status;
struct link_socket_info *lsi = get_link_socket_info (c);
const uint8_t *orig_buf = c->c2.buf.data;
perf_push (PERF_PROC_IN_LINK);
if (c->c2.buf.len > 0)
{
c->c2.link_read_bytes += c->c2.buf.len;
c->c2.original_recv_size = c->c2.buf.len;
#ifdef ENABLE_MANAGEMENT
if (management)
management_bytes_in (management, c->c2.buf.len);
#endif
}
else
c->c2.original_recv_size = 0;
#ifdef ENABLE_DEBUG
/* take action to corrupt packet if we are in gremlin test mode */
if (c->options.gremlin) {
if (!ask_gremlin (c->options.gremlin))
c->c2.buf.len = 0;
corrupt_gremlin (&c->c2.buf, c->options.gremlin);
}
#endif
/* log incoming packet */
#ifdef LOG_RW
if (c->c2.log_rw)
fprintf (stderr, "R");
#endif
msg (D_LINK_RW, "%s READ [%d] from %s: %s",
proto2ascii (lsi->proto, true),
BLEN (&c->c2.buf),
print_link_socket_actual (&c->c2.from, &gc),
PROTO_DUMP (&c->c2.buf, &gc));
/*
* Good, non-zero length packet received.
* Commence multi-stage processing of packet,
* such as authenticate, decrypt, decompress.
* If any stage fails, it sets buf.len to 0 or -1,
* telling downstream stages to ignore the packet.
*/
if (c->c2.buf.len > 0)
{
if (!link_socket_verify_incoming_addr (&c->c2.buf, lsi, &c->c2.from))
link_socket_bad_incoming_addr (&c->c2.buf, lsi, &c->c2.from);
#ifdef USE_CRYPTO
#ifdef USE_SSL
if (c->c2.tls_multi)
{
/*
* If tls_pre_decrypt returns true, it means the incoming
* packet was a good TLS control channel packet. If so, TLS code
* will deal with the packet and set buf.len to 0 so downstream
* stages ignore it.
*
* If the packet is a data channel packet, tls_pre_decrypt
* will load crypto_options with the correct encryption key
* and return false.
*/
/*tls_mutex_lock (c->c2.tls_multi);*/
if (tls_pre_decrypt (c->c2.tls_multi, &c->c2.from, &c->c2.buf, &c->c2.crypto_options))
{
interval_action (&c->c2.tmp_int);
/* reset packet received timer if TLS packet */
if (c->options.ping_rec_timeout)
event_timeout_reset (&c->c2.ping_rec_interval);
}
}
#if P2MP_SERVER
/*
* Drop non-TLS packet if client-connect script/plugin has not
* yet succeeded.
*/
if (c->c2.context_auth != CAS_SUCCEEDED)
c->c2.buf.len = 0;
#endif
#endif /* USE_SSL */
/* authenticate and decrypt the incoming packet */
decrypt_status = openvpn_decrypt (&c->c2.buf, c->c2.buffers->decrypt_buf, &c->c2.crypto_options, &c->c2.frame);
#ifdef USE_SSL
if (c->c2.tls_multi)
{
/*tls_mutex_unlock (c->c2.tls_multi);*/
}
#endif
if (!decrypt_status && link_socket_connection_oriented (c->c2.link_socket))
{
/* decryption errors are fatal in TCP mode */
c->sig->signal_received = SIGUSR1; /* SOFT-SIGUSR1 -- decryption error in TCP mode */
c->sig->signal_text = "decryption-error";
msg (D_STREAM_ERRORS, "Fatal decryption error (process_incoming_link), restarting");
goto done;
}
#endif /* USE_CRYPTO */
#ifdef ENABLE_FRAGMENT
if (c->c2.fragment)
fragment_incoming (c->c2.fragment, &c->c2.buf, &c->c2.frame_fragment);
#endif
#ifdef USE_LZO
/* decompress the incoming packet */
if (lzo_defined (&c->c2.lzo_compwork))
lzo_decompress (&c->c2.buf, c->c2.buffers->lzo_decompress_buf, &c->c2.lzo_compwork, &c->c2.frame);
#endif
#ifdef PACKET_TRUNCATION_CHECK
/* if (c->c2.buf.len > 1) --c->c2.buf.len; */
ipv4_packet_size_verify (BPTR (&c->c2.buf),
BLEN (&c->c2.buf),
TUNNEL_TYPE (c->c1.tuntap),
"POST_DECRYPT",
&c->c2.n_trunc_post_decrypt);
#endif
/*
* Set our "official" outgoing address, since
* if buf.len is non-zero, we know the packet
* authenticated. In TLS mode we do nothing
* because TLS mode takes care of source address
* authentication.
*
* Also, update the persisted version of our packet-id.
*/
if (!TLS_MODE (c))
link_socket_set_outgoing_addr (&c->c2.buf, lsi, &c->c2.from, NULL, c->c2.es);
/* reset packet received timer */
if (c->options.ping_rec_timeout && c->c2.buf.len > 0)
event_timeout_reset (&c->c2.ping_rec_interval);
/* increment authenticated receive byte count */
if (c->c2.buf.len > 0)
{
c->c2.link_read_bytes_auth += c->c2.buf.len;
c->c2.max_recv_size_local = max_int (c->c2.original_recv_size, c->c2.max_recv_size_local);
}
/* Did we just receive an openvpn ping packet? */
if (is_ping_msg (&c->c2.buf))
{
dmsg (D_PING, "RECEIVED PING PACKET");
c->c2.buf.len = 0; /* drop packet */
}
#ifdef ENABLE_OCC
/* Did we just receive an OCC packet? */
if (is_occ_msg (&c->c2.buf))
process_received_occ_msg (c);
#endif
buffer_turnover (orig_buf, &c->c2.to_tun, &c->c2.buf, &c->c2.buffers->read_link_buf);
/* to_tun defined + unopened tuntap can cause deadlock */
if (!tuntap_defined (c->c1.tuntap))
c->c2.to_tun.len = 0;
}
else
{
buf_reset (&c->c2.to_tun);
}
done:
perf_pop ();
gc_free (&gc);
}
/*
* Output: c->c2.buf
*/
void
read_incoming_tun (struct context *c)
{
/*
* Setup for read() call on TUN/TAP device.
*/
/*ASSERT (!c->c2.to_link.len);*/
perf_push (PERF_READ_IN_TUN);
c->c2.buf = c->c2.buffers->read_tun_buf;
#ifdef TUN_PASS_BUFFER
read_tun_buffered (c->c1.tuntap, &c->c2.buf, MAX_RW_SIZE_TUN (&c->c2.frame));
#else
ASSERT (buf_init (&c->c2.buf, FRAME_HEADROOM (&c->c2.frame)));
ASSERT (buf_safe (&c->c2.buf, MAX_RW_SIZE_TUN (&c->c2.frame)));
c->c2.buf.len = read_tun (c->c1.tuntap, BPTR (&c->c2.buf), MAX_RW_SIZE_TUN (&c->c2.frame));
#endif
#ifdef PACKET_TRUNCATION_CHECK
ipv4_packet_size_verify (BPTR (&c->c2.buf),
BLEN (&c->c2.buf),
TUNNEL_TYPE (c->c1.tuntap),
"READ_TUN",
&c->c2.n_trunc_tun_read);
#endif
/* Was TUN/TAP interface stopped? */
if (tuntap_stop (c->c2.buf.len))
{
c->sig->signal_received = SIGTERM;
c->sig->signal_text = "tun-stop";
msg (M_INFO, "TUN/TAP interface has been stopped, exiting");
perf_pop ();
return;
}
/* Check the status return from read() */
check_status (c->c2.buf.len, "read from TUN/TAP", NULL, c->c1.tuntap);
perf_pop ();
}
/*
* Input: c->c2.buf
* Output: c->c2.to_link
*/
void
process_incoming_tun (struct context *c)
{
struct gc_arena gc = gc_new ();
perf_push (PERF_PROC_IN_TUN);
if (c->c2.buf.len > 0)
c->c2.tun_read_bytes += c->c2.buf.len;
#ifdef LOG_RW
if (c->c2.log_rw)
fprintf (stderr, "r");
#endif
/* Show packet content */
dmsg (D_TUN_RW, "TUN READ [%d]", BLEN (&c->c2.buf));
if (c->c2.buf.len > 0)
{
/*
* The --passtos and --mssfix options require
* us to examine the IPv4 header.
*/
process_ipv4_header (c, PIPV4_PASSTOS|PIPV4_MSSFIX, &c->c2.buf);
#ifdef PACKET_TRUNCATION_CHECK
/* if (c->c2.buf.len > 1) --c->c2.buf.len; */
ipv4_packet_size_verify (BPTR (&c->c2.buf),
BLEN (&c->c2.buf),
TUNNEL_TYPE (c->c1.tuntap),
"PRE_ENCRYPT",
&c->c2.n_trunc_pre_encrypt);
#endif
encrypt_sign (c, true);
}
else
{
buf_reset (&c->c2.to_link);
}
perf_pop ();
gc_free (&gc);
}
void
process_ipv4_header (struct context *c, unsigned int flags, struct buffer *buf)
{
if (!c->options.mssfix)
flags &= ~PIPV4_MSSFIX;
#if PASSTOS_CAPABILITY
if (!c->options.passtos)
flags &= ~PIPV4_PASSTOS;
#endif
if (buf->len > 0)
{
/*
* The --passtos and --mssfix options require
* us to examine the IPv4 header.
*/
#if PASSTOS_CAPABILITY
if (flags & (PIPV4_PASSTOS|PIPV4_MSSFIX))
#else
if (flags & PIPV4_MSSFIX)
#endif
{
struct buffer ipbuf = *buf;
if (is_ipv4 (TUNNEL_TYPE (c->c1.tuntap), &ipbuf))
{
#if PASSTOS_CAPABILITY
/* extract TOS from IP header */
if (flags & PIPV4_PASSTOS)
link_socket_extract_tos (c->c2.link_socket, &ipbuf);
#endif
/* possibly alter the TCP MSS */
if (flags & PIPV4_MSSFIX)
mss_fixup (&ipbuf, MTU_TO_MSS (TUN_MTU_SIZE_DYNAMIC (&c->c2.frame)));
}
}
}
}
/*
* Input: c->c2.to_link
*/
void
process_outgoing_link (struct context *c)
{
struct gc_arena gc = gc_new ();
perf_push (PERF_PROC_OUT_LINK);
if (c->c2.to_link.len > 0 && c->c2.to_link.len <= EXPANDED_SIZE (&c->c2.frame))
{
/*
* Setup for call to send/sendto which will send
* packet to remote over the TCP/UDP port.
*/
int size = 0;
ASSERT (link_socket_actual_defined (c->c2.to_link_addr));
#ifdef ENABLE_DEBUG
/* In gremlin-test mode, we may choose to drop this packet */
if (!c->options.gremlin || ask_gremlin (c->options.gremlin))
#endif
{
/*
* Let the traffic shaper know how many bytes
* we wrote.
*/
#ifdef HAVE_GETTIMEOFDAY
if (c->options.shaper)
shaper_wrote_bytes (&c->c2.shaper, BLEN (&c->c2.to_link)
+ datagram_overhead (c->options.proto));
#endif
/*
* Let the pinger know that we sent a packet.
*/
if (c->options.ping_send_timeout)
event_timeout_reset (&c->c2.ping_send_interval);
#if PASSTOS_CAPABILITY
/* Set TOS */
link_socket_set_tos (c->c2.link_socket);
#endif
/* Log packet send */
#ifdef LOG_RW
if (c->c2.log_rw)
fprintf (stderr, "W");
#endif
msg (D_LINK_RW, "%s WRITE [%d] to %s: %s",
proto2ascii (c->c2.link_socket->info.proto, true),
BLEN (&c->c2.to_link),
print_link_socket_actual (c->c2.to_link_addr, &gc),
PROTO_DUMP (&c->c2.to_link, &gc));
/* Packet send complexified by possible Socks5 usage */
{
struct link_socket_actual *to_addr = c->c2.to_link_addr;
#ifdef ENABLE_SOCKS
int size_delta = 0;
#endif
#ifdef ENABLE_SOCKS
/* If Socks5 over UDP, prepend header */
socks_preprocess_outgoing_link (c, &to_addr, &size_delta);
#endif
/* Send packet */
size = link_socket_write (c->c2.link_socket,
&c->c2.to_link,
to_addr);
#ifdef ENABLE_SOCKS
/* Undo effect of prepend */
link_socket_write_post_size_adjust (&size, size_delta, &c->c2.to_link);
#endif
}
if (size > 0)
{
c->c2.max_send_size_local = max_int (size, c->c2.max_send_size_local);
c->c2.link_write_bytes += size;
#ifdef ENABLE_MANAGEMENT
if (management)
management_bytes_out (management, size);
#endif
}
}
/* Check return status */
check_status (size, "write", c->c2.link_socket, NULL);
if (size > 0)
{
/* Did we write a different size packet than we intended? */
if (size != BLEN (&c->c2.to_link))
msg (D_LINK_ERRORS,
"TCP/UDP packet was truncated/expanded on write to %s (tried=%d,actual=%d)",
print_link_socket_actual (c->c2.to_link_addr, &gc),
BLEN (&c->c2.to_link),
size);
}
/* indicate activity regarding --inactive parameter */
register_activity (c, size);
}
else
{
if (c->c2.to_link.len > 0)
msg (D_LINK_ERRORS, "TCP/UDP packet too large on write to %s (tried=%d,max=%d)",
print_link_socket_actual (c->c2.to_link_addr, &gc),
c->c2.to_link.len,
EXPANDED_SIZE (&c->c2.frame));
}
buf_reset (&c->c2.to_link);
perf_pop ();
gc_free (&gc);
}
/*
* Input: c->c2.to_tun
*/
void
process_outgoing_tun (struct context *c)
{
struct gc_arena gc = gc_new ();
/*
* Set up for write() call to TUN/TAP
* device.
*/
if (c->c2.to_tun.len <= 0)
return;
perf_push (PERF_PROC_OUT_TUN);
/*
* The --mssfix option requires
* us to examine the IPv4 header.
*/
process_ipv4_header (c, PIPV4_MSSFIX|PIPV4_OUTGOING, &c->c2.to_tun);
if (c->c2.to_tun.len <= MAX_RW_SIZE_TUN (&c->c2.frame))
{
/*
* Write to TUN/TAP device.
*/
int size;
#ifdef LOG_RW
if (c->c2.log_rw)
fprintf (stderr, "w");
#endif
dmsg (D_TUN_RW, "TUN WRITE [%d]", BLEN (&c->c2.to_tun));
#ifdef PACKET_TRUNCATION_CHECK
ipv4_packet_size_verify (BPTR (&c->c2.to_tun),
BLEN (&c->c2.to_tun),
TUNNEL_TYPE (c->c1.tuntap),
"WRITE_TUN",
&c->c2.n_trunc_tun_write);
#endif
#ifdef TUN_PASS_BUFFER
size = write_tun_buffered (c->c1.tuntap, &c->c2.to_tun);
#else
size = write_tun (c->c1.tuntap, BPTR (&c->c2.to_tun), BLEN (&c->c2.to_tun));
#endif
if (size > 0)
c->c2.tun_write_bytes += size;
check_status (size, "write to TUN/TAP", NULL, c->c1.tuntap);
/* check written packet size */
if (size > 0)
{
/* Did we write a different size packet than we intended? */
if (size != BLEN (&c->c2.to_tun))
msg (D_LINK_ERRORS,
"TUN/TAP packet was destructively fragmented on write to %s (tried=%d,actual=%d)",
c->c1.tuntap->actual_name,
BLEN (&c->c2.to_tun),
size);
/* indicate activity regarding --inactive parameter */
register_activity (c, size);
}
}
else
{
/*
* This should never happen, probably indicates some kind
* of MTU mismatch.
*/
msg (D_LINK_ERRORS, "tun packet too large on write (tried=%d,max=%d)",
c->c2.to_tun.len,
MAX_RW_SIZE_TUN (&c->c2.frame));
}
buf_reset (&c->c2.to_tun);
perf_pop ();
gc_free (&gc);
}
void
pre_select (struct context *c)
{
/* make sure current time (now) is updated on function entry */
/*
* Start with an effectively infinite timeout, then let it
* reduce to a timeout that reflects the component which
* needs the earliest service.
*/
c->c2.timeval.tv_sec = BIG_TIMEOUT;
c->c2.timeval.tv_usec = 0;
#if defined(WIN32)
if (check_debug_level (D_TAP_WIN32_DEBUG))
{
c->c2.timeval.tv_sec = 1;
if (tuntap_defined (c->c1.tuntap))
tun_show_debug (c->c1.tuntap);
}
#endif
/* check coarse timers? */
check_coarse_timers (c);
if (c->sig->signal_received)
return;
/* Does TLS need service? */
check_tls (c);
/* In certain cases, TLS errors will require a restart */
check_tls_errors (c);
if (c->sig->signal_received)
return;
/* check for incoming configuration info on the control channel */
check_incoming_control_channel (c);
#ifdef ENABLE_OCC
/* Should we send an OCC message? */
check_send_occ_msg (c);
#endif
#ifdef ENABLE_FRAGMENT
/* Should we deliver a datagram fragment to remote? */
check_fragment (c);
#endif
/* Update random component of timeout */
check_timeout_random_component (c);
}
/*
* Wait for I/O events. Used for both TCP & UDP sockets
* in point-to-point mode and for UDP sockets in
* point-to-multipoint mode.
*/
void
io_wait_dowork (struct context *c, const unsigned int flags)
{
unsigned int socket = 0;
unsigned int tuntap = 0;
struct event_set_return esr[4];
/* These shifts all depend on EVENT_READ and EVENT_WRITE */
static const int socket_shift = 0; /* depends on SOCKET_READ and SOCKET_WRITE */
static const int tun_shift = 2; /* depends on TUN_READ and TUN_WRITE */
static const int err_shift = 4; /* depends on ES_ERROR */
#ifdef ENABLE_MANAGEMENT
static const int management_shift = 6; /* depends on MANAGEMENT_READ and MANAGEMENT_WRITE */
#endif
/*
* Decide what kind of events we want to wait for.
*/
event_reset (c->c2.event_set);
/*
* On win32 we use the keyboard or an event object as a source
* of asynchronous signals.
*/
if (flags & IOW_WAIT_SIGNAL)
wait_signal (c->c2.event_set, (void*)&err_shift);
/*
* If outgoing data (for TCP/UDP port) pending, wait for ready-to-send
* status from TCP/UDP port. Otherwise, wait for incoming data on
* TUN/TAP device.
*/
if (flags & IOW_TO_LINK)
{
if (flags & IOW_SHAPER)
{
/*
* If sending this packet would put us over our traffic shaping
* quota, don't send -- instead compute the delay we must wait
* until it will be OK to send the packet.
*/
#ifdef HAVE_GETTIMEOFDAY
int delay = 0;
/* set traffic shaping delay in microseconds */
if (c->options.shaper)
delay = max_int (delay, shaper_delay (&c->c2.shaper));
if (delay < 1000)
{
socket |= EVENT_WRITE;
}
else
{
shaper_soonest_event (&c->c2.timeval, delay);
}
#else /* HAVE_GETTIMEOFDAY */
socket |= EVENT_WRITE;
#endif /* HAVE_GETTIMEOFDAY */
}
else
{
socket |= EVENT_WRITE;
}
}
else if (!((flags & IOW_FRAG) && TO_LINK_FRAG (c)))
{
if (flags & IOW_READ_TUN)
tuntap |= EVENT_READ;
}
/*
* If outgoing data (for TUN/TAP device) pending, wait for ready-to-send status
* from device. Otherwise, wait for incoming data on TCP/UDP port.
*/
if (flags & IOW_TO_TUN)
{
tuntap |= EVENT_WRITE;
}
else
{
if (flags & IOW_READ_LINK)
socket |= EVENT_READ;
}
/*
* outgoing bcast buffer waiting to be sent?
*/
if (flags & IOW_MBUF)
socket |= EVENT_WRITE;
/*
* Force wait on TUN input, even if also waiting on TCP/UDP output
*/
if (flags & IOW_READ_TUN_FORCE)
tuntap |= EVENT_READ;
/*
* Configure event wait based on socket, tuntap flags.
*/
socket_set (c->c2.link_socket, c->c2.event_set, socket, (void*)&socket_shift, NULL);
tun_set (c->c1.tuntap, c->c2.event_set, tuntap, (void*)&tun_shift, NULL);
#ifdef ENABLE_MANAGEMENT
if (management)
management_socket_set (management, c->c2.event_set, (void*)&management_shift, NULL);
#endif
/*
* Possible scenarios:
* (1) tcp/udp port has data available to read
* (2) tcp/udp port is ready to accept more data to write
* (3) tun dev has data available to read
* (4) tun dev is ready to accept more data to write
* (5) we received a signal (handler sets signal_received)
* (6) timeout (tv) expired
*/
c->c2.event_set_status = ES_ERROR;
if (!c->sig->signal_received)
{
if (!(flags & IOW_CHECK_RESIDUAL) || !socket_read_residual (c->c2.link_socket))
{
int status;
#ifdef ENABLE_DEBUG
if (check_debug_level (D_EVENT_WAIT))
show_wait_status (c);
#endif
/*
* Wait for something to happen.
*/
status = event_wait (c->c2.event_set, &c->c2.timeval, esr, SIZE(esr));
check_status (status, "event_wait", NULL, NULL);
if (status > 0)
{
int i;
c->c2.event_set_status = 0;
for (i = 0; i < status; ++i)
{
const struct event_set_return *e = &esr[i];
c->c2.event_set_status |= ((e->rwflags & 3) << *((int*)e->arg));
}
}
else if (status == 0)
{
c->c2.event_set_status = ES_TIMEOUT;
}
}
else
{
c->c2.event_set_status = SOCKET_READ;
}
}
/* 'now' should always be a reasonably up-to-date timestamp */
update_time ();
/* set signal_received if a signal was received */
if (c->c2.event_set_status & ES_ERROR)
get_signal (&c->sig->signal_received);
dmsg (D_EVENT_WAIT, "I/O WAIT status=0x%04x", c->c2.event_set_status);
}
void
process_io (struct context *c)
{
const unsigned int status = c->c2.event_set_status;
#ifdef ENABLE_MANAGEMENT
if (status & (MANAGEMENT_READ|MANAGEMENT_WRITE))
{
ASSERT (management);
management_io (management);
}
#endif
/* TCP/UDP port ready to accept write */
if (status & SOCKET_WRITE)
{
process_outgoing_link (c);
}
/* TUN device ready to accept write */
else if (status & TUN_WRITE)
{
process_outgoing_tun (c);
}
/* Incoming data on TCP/UDP port */
else if (status & SOCKET_READ)
{
read_incoming_link (c);
if (!IS_SIG (c))
process_incoming_link (c);
}
/* Incoming data on TUN device */
else if (status & TUN_READ)
{
read_incoming_tun (c);
if (!IS_SIG (c))
process_incoming_tun (c);
}
}
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