From e1e977f3cc52e230031f8770b0a9c977eab7db69 Mon Sep 17 00:00:00 2001
From: james <james@e7ae566f-a301-0410-adde-c780ea21d3b5>
Date: Mon, 28 Sep 2009 07:27:22 +0000
Subject: Added --server-poll-timeout option : when polling possible remote
 servers to connect to in a round-robin fashion, spend no more than n seconds
 waiting for a response before trying the next server.

git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@5010 e7ae566f-a301-0410-adde-c780ea21d3b5
---
 forward-inline.h | 11 +++++++++++
 forward.c        | 17 +++++++++++++++++
 init.c           | 10 ++++++++++
 openvpn.8        |  7 +++++++
 openvpn.h        |  2 ++
 options.c        | 15 +++++++++++++++
 options.h        |  2 ++
 ssl.h            |  6 ++++++
 8 files changed, 70 insertions(+)

diff --git a/forward-inline.h b/forward-inline.h
index c87996d..bb8f542 100644
--- a/forward-inline.h
+++ b/forward-inline.h
@@ -119,6 +119,17 @@ check_inactivity_timeout (struct context *c)
 }
 
 #if P2MP
+
+static inline void
+check_server_poll_timeout (struct context *c)
+{
+  void check_server_poll_timeout_dowork (struct context *c);
+
+  if (c->options.server_poll_timeout
+      && event_timeout_trigger (&c->c2.server_poll_interval, &c->c2.timeval, ETT_DEFAULT))
+    check_server_poll_timeout_dowork (c);
+}
+
 /*
  * Scheduled exit?
  */
diff --git a/forward.c b/forward.c
index 2205054..87f3350 100644
--- a/forward.c
+++ b/forward.c
@@ -314,6 +314,19 @@ check_inactivity_timeout_dowork (struct context *c)
 
 #if P2MP
 
+void
+check_server_poll_timeout_dowork (struct context *c)
+{
+  event_timeout_reset (&c->c2.server_poll_interval);
+  if (!tls_initial_packet_received (c->c2.tls_multi))
+    {
+      msg (M_INFO, "Server poll timeout, restarting");
+      c->sig->signal_received = SIGUSR1;
+      c->sig->signal_text = "server_poll";
+      c->persist.restart_sleep_seconds = -1;
+    }
+}
+
 /*
  * Schedule a SIGTERM n_seconds from now.
  */
@@ -516,6 +529,10 @@ process_coarse_timers (struct context *c)
     return;
 
 #if P2MP
+  check_server_poll_timeout (c);
+  if (c->sig->signal_received)
+    return;
+
   check_scheduled_exit (c);
   if (c->sig->signal_received)
     return;
diff --git a/init.c b/init.c
index 9d29af7..20ca0a5 100644
--- a/init.c
+++ b/init.c
@@ -792,6 +792,11 @@ do_init_timers (struct context *c, bool deferred)
   if (c->options.ping_rec_timeout)
     event_timeout_init (&c->c2.ping_rec_interval, c->options.ping_rec_timeout, now);
 
+#if P2MP
+  if (c->options.server_poll_timeout)
+    event_timeout_init (&c->c2.server_poll_interval, c->options.server_poll_timeout, now);
+#endif
+
   if (!deferred)
     {
       /* initialize connection establishment timer */
@@ -1444,10 +1449,15 @@ socket_restart_pause (struct context *c)
 #if P2MP
   if (auth_retry_get () == AR_NOINTERACT)
     sec = 10;
+
+  if (c->options.server_poll_timeout && sec > 1)
+    sec = 1;
 #endif
 
   if (c->persist.restart_sleep_seconds > 0 && c->persist.restart_sleep_seconds > sec)
     sec = c->persist.restart_sleep_seconds;
+  else if (c->persist.restart_sleep_seconds == -1)
+    sec = 0;
   c->persist.restart_sleep_seconds = 0;
 
   /* do managment hold on context restart, i.e. second, third, fourth, etc. initialization */
diff --git a/openvpn.8 b/openvpn.8
index e9bc113..6f6138b 100644
--- a/openvpn.8
+++ b/openvpn.8
@@ -3279,6 +3279,13 @@ Note that while this option cannot be pushed, it can be controlled
 from the management interface.
 .\"*********************************************************
 .TP
+.B --server-poll-timeout n
+when polling possible remote servers to connect to
+in a round-robin fashion, spend no more than
+.B n
+seconds waiting for a response before trying the next server.
+.\"*********************************************************
+.TP
 .B --explicit-exit-notify [n]
 In UDP client mode or point-to-point mode, send server/peer an exit notification
 if tunnel is restarted or OpenVPN process is exited.  In client mode, on
diff --git a/openvpn.h b/openvpn.h
index b850fd0..70df9e0 100644
--- a/openvpn.h
+++ b/openvpn.h
@@ -433,6 +433,8 @@ struct context_2
   struct md5_state pulled_options_state;
   struct md5_digest pulled_options_digest;
 
+  struct event_timeout server_poll_interval;
+
   struct event_timeout scheduled_exit;
 #endif
 
diff --git a/options.c b/options.c
index ce16b56..afd804f 100644
--- a/options.c
+++ b/options.c
@@ -432,6 +432,9 @@ static const char usage_message[] =
   "                  when connecting to a '--mode server' remote host.\n"
   "--auth-retry t  : How to handle auth failures.  Set t to\n"
   "                  none (default), interact, or nointeract.\n"
+  "--server-poll-timeout n : when polling possible remote servers to connect to\n"
+  "                  in a round-robin fashion, spend no more than n seconds\n"
+  "                  waiting for a response before trying the next server.\n"
 #endif
 #ifdef ENABLE_OCC
   "--explicit-exit-notify [n] : On exit/restart, send exit signal to\n"
@@ -726,6 +729,7 @@ init_options (struct options *o, const bool init_gc)
 #endif
 #if P2MP
   o->scheduled_exit_interval = 5;
+  o->server_poll_timeout = 0;
 #endif
 #ifdef USE_CRYPTO
   o->ciphername = "BF-CBC";
@@ -4464,6 +4468,12 @@ add_option (struct options *options,
 	{
 	  options->sockflags |= SF_HOST_RANDOMIZE;
 	}
+#if P2MP
+      else if (streq (p[1], "SERVER_POLL_TIMEOUT") && p[2])
+	{
+	  options->server_poll_timeout = positive_atoi(p[2]);
+	}
+#endif
       else
 	{
 	  if (streq (p[1], "FORWARD_COMPATIBLE") && p[2] && streq (p[2], "1"))
@@ -4887,6 +4897,11 @@ add_option (struct options *options,
       VERIFY_PERMISSION (OPT_P_PULL_MODE);
       options->push_continuation = atoi(p[1]);
     }
+  else if (streq (p[0], "server-poll-timeout") && p[1])
+    {
+      VERIFY_PERMISSION (OPT_P_GENERAL);
+      options->server_poll_timeout = positive_atoi(p[1]);
+    }
   else if (streq (p[0], "auth-user-pass"))
     {
       VERIFY_PERMISSION (OPT_P_GENERAL);
diff --git a/options.h b/options.h
index fbf0e3c..740e18e 100644
--- a/options.h
+++ b/options.h
@@ -399,6 +399,8 @@ struct options
   const char *auth_user_pass_file;
   struct options_pre_pull *pre_pull;
 
+  int server_poll_timeout;
+
   int scheduled_exit_interval;
 
 #endif
diff --git a/ssl.h b/ssl.h
index 910c77c..e7ccb42 100644
--- a/ssl.h
+++ b/ssl.h
@@ -702,6 +702,12 @@ bool tls_authenticate_key (struct tls_multi *multi, const unsigned int mda_key_i
  * inline functions
  */
 
+static inline bool
+tls_initial_packet_received (const struct tls_multi *multi)
+{
+  return multi->n_sessions > 0;
+}
+
 static inline bool
 tls_test_auth_deferred_interval (const struct tls_multi *multi)
 {
-- 
cgit