Hi,
this is simple patch implementing internal openvpn ping over OCC channel.
Important difference of OCC ping (OCC_PING) to existing one is that
this one is replied on the other side of the channel (with
OCC_PING_REPLY),
thus making it possible to configure clients and server ping and
ping-restart timeout differently.
This might be usefull if someone is trying to combine mobile and
non-mobile clients on one openvpn server. Non-mobile clients might
want to have
reliable link and ping more frequently compared to mobile clients
that might not want this (ie. to save battery on android ;-).
OCC ping replaces 'normal' ping if activated via occ-ping directive,
and thus fully integrates with all ping/ping-restart/... directives.
Additionaly I've implemented occ-ping-compat mode, that will send
OCC_REQUEST instread of OCC_PING. All OCC clients will then reply to
this
request with OCC_REPLY message - it might be usefull to enable this
on server, to stay backward compatible with older non occ-ping
clients.
Please review it ;)
Thanks.
Sam
diff -ur openvpn-2.2.2/occ.c openvpn-2.2.2-dev/occ.c
--- openvpn-2.2.2/occ.c 2011-12-13 17:58:56.000000000 +0100
+++ openvpn-2.2.2-dev/occ.c 2012-05-27 19:23:15.000000000 +0200
@@ -302,6 +302,29 @@
dmsg (D_PACKET_CONTENT, "SENT OCC_EXIT");
doit = true;
break;
+
+ case OCC_PING:
+ if (c->options.occ_ping_compat)
+ {
+ if (!buf_write_u8 (&c->c2.buf, OCC_REQUEST))
+ break;
+ dmsg (D_PACKET_CONTENT, "SENT OCC_REQUEST (compat OCC_PING)");
+ }
+ else
+ {
+ if (!buf_write_u8 (&c->c2.buf, OCC_PING))
+ break;
+ dmsg (D_PACKET_CONTENT, "SENT OCC_PING");
+ }
+ doit = true;
+ break;
+
+ case OCC_PING_REPLY:
+ if (!buf_write_u8 (&c->c2.buf, OCC_PING_REPLY))
+ break;
+ dmsg (D_PACKET_CONTENT, "SENT OCC_PING_REPLY");
+ doit = true;
+ break;
}
if (doit)
@@ -384,6 +407,14 @@
c->sig->signal_received = SIGTERM;
c->sig->signal_text = "remote-exit";
break;
+
+ case OCC_PING:
+ dmsg (D_PACKET_CONTENT, "RECEIVED OCC_PING");
+ c->c2.occ_op = OCC_PING_REPLY;
+ break;
+ case OCC_PING_REPLY:
+ dmsg (D_PACKET_CONTENT, "RECEIVED OCC_PING_REPLY");
+ break;
}
c->c2.buf.len = 0; /* don't pass packet on */
}
diff -ur openvpn-2.2.2/occ.h openvpn-2.2.2-dev/occ.h
--- openvpn-2.2.2/occ.h 2011-04-26 10:33:04.000000000 +0200
+++ openvpn-2.2.2-dev/occ.h 2012-05-25 23:07:18.000000000 +0200
@@ -70,6 +70,13 @@
#define OCC_EXIT 6
/*
+ * OCC based ping
+ */
+#define OCC_PING 7
+#define OCC_PING_REPLY 8
+
+
+/*
* Used to conduct a load test command sequence
* of UDP connection for empirical MTU measurement.
*/
diff -ur openvpn-2.2.2/options.c openvpn-2.2.2-dev/options.c
--- openvpn-2.2.2/options.c 2011-12-13 17:58:56.000000000 +0100
+++ openvpn-2.2.2-dev/options.c 2012-05-25 23:20:55.000000000 +0200
@@ -229,6 +229,11 @@
"--ping-timer-rem: Run the --ping-exit/--ping-restart timer only if
we have a\n"
" remote address.\n"
"--ping n : Ping remote once every n seconds over TCP/UDP port.\n"
+#ifdef ENABLE_OCC
+ "--occ-ping : Ping using internal OCC protocol.\n"
+ "--occ-ping-compat : Use backward compatible OCC ping.\n"
+ " Use for clients without occ-ping support.\n"
+#endif
#if ENABLE_IP_PKTINFO
"--multihome : Configure a multi-homed UDP server.\n"
#endif
@@ -1235,8 +1240,11 @@
SHOW_BOOL (ping_timer_remote);
SHOW_INT (remap_sigusr1);
#ifdef ENABLE_OCC
+ SHOW_BOOL (occ_ping);
+ SHOW_BOOL (occ_ping_compat);
SHOW_INT (explicit_exit_notification);
#endif
+
SHOW_BOOL (persist_tun);
SHOW_BOOL (persist_local_ip);
SHOW_BOOL (persist_remote_ip);
@@ -4529,6 +4537,16 @@
options->ping_timer_remote = true;
}
#ifdef ENABLE_OCC
+ else if (streq (p[0], "occ-ping"))
+ {
+ VERIFY_PERMISSION (OPT_P_TIMER);
+ options->occ_ping = true;
+ }
+ else if (streq (p[0], "occ-ping-compat"))
+ {
+ VERIFY_PERMISSION (OPT_P_TIMER);
+ options->occ_ping_compat = true;
+ }
else if (streq (p[0], "explicit-exit-notify"))
{
VERIFY_PERMISSION (OPT_P_EXPLICIT_NOTIFY);
diff -ur openvpn-2.2.2/options.h openvpn-2.2.2-dev/options.h
--- openvpn-2.2.2/options.h 2011-12-13 17:58:56.000000000 +0100
+++ openvpn-2.2.2-dev/options.h 2012-05-25 23:04:14.000000000 +0200
@@ -239,6 +239,11 @@
int ping_send_timeout; /* Send a TCP/UDP ping to remote
every n seconds */
int ping_rec_timeout; /* Expect a TCP/UDP ping from remote
at least once every n seconds */
bool ping_timer_remote; /* Run ping timer only if we have a
remote address */
+#ifdef ENABLE_OCC
+ bool occ_ping; /* Enable OCC ping */
+ bool occ_ping_compat; /* Enable OCC ping compatibility mode */
+#endif
+
bool tun_ipv6; /* Build tun dev that supports IPv6 */
# define PING_UNDEF 0
diff -ur openvpn-2.2.2/ping-inline.h openvpn-2.2.2-dev/ping-inline.h
--- openvpn-2.2.2/ping-inline.h 2011-04-26 10:33:04.000000000 +0200
+++ openvpn-2.2.2-dev/ping-inline.h 2012-05-27 18:50:40.000000000 +0200
@@ -53,7 +53,14 @@
&& event_timeout_trigger (&c->c2.ping_send_interval,
&c->c2.timeval,
!TO_LINK_DEF(c) ? ETT_DEFAULT : 1))
- check_ping_send_dowork (c);
+ {
+#ifdef ENABLE_OCC
+ if(c->options.occ_ping)
+ c->c2.occ_op = OCC_PING;
+ else
+#endif
+ check_ping_send_dowork (c);
+ }
}
#endif
