Instead of statically increasing link-mtu by +3, keep the old value for
OCC compatibility with old servers/clients, and only increase link-mtu
if peer-id option is enabled (right now: is pushed by server).
If link-mtu has been set in the config, keep configured value, and log
warning (because the extra overhead has to decrease tun-mtu).
Reserve extra +3 bytes in frame->extra_buffer.
This reverts commit f95010ad247a8998e0c39e394236251fca316849.
Signed-off-by: Gert Doering <g...@greenie.muc.de>
---
src/openvpn/init.c | 19 +++++++++++++++++++
src/openvpn/ssl.c | 10 ++++++----
2 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/src/openvpn/init.c b/src/openvpn/init.c
index 706d07c..a4ef84b 100644
--- a/src/openvpn/init.c
+++ b/src/openvpn/init.c
@@ -1794,6 +1794,19 @@ do_deferred_options (struct context *c, const unsigned
int found)
msg (D_PUSH, "OPTIONS IMPORT: peer-id set");
c->c2.tls_multi->use_peer_id = true;
c->c2.tls_multi->peer_id = c->options.peer_id;
+ frame_add_to_extra_frame(&c->c2.frame, +3); /* peer-id overhead */
+ if ( !c->options.ce.link_mtu_defined )
+ {
+ c->c2.frame.link_mtu += 3;
+ msg (D_PUSH, "OPTIONS IMPORT: adjusting link_mtu to %d",
+ EXPANDED_SIZE(&c->c2.frame));
+ }
+ else
+ {
+ msg (M_WARN, "OPTIONS IMPORT: WARNING: peer-id set, but link-mtu"
+ " fixed by config - reducing tun-mtu to %d, expect"
+ " MTU problems", TUN_MTU_SIZE(&c->c2.frame) );
+ }
}
#endif
}
@@ -2403,6 +2416,12 @@ do_init_frame (struct context *c)
#endif
#endif /* USE_COMP */
+ /* packets with peer-id (P_DATA_V2) need 3 extra bytes in frame.
+ * reserve in f->extra_buffer, adjust f->extra_frame when peer-id option
+ * is push-received (where it's too late to change BUF_SIZE(f) allocations)
+ */
+ frame_add_to_extra_buffer(&c->c2.frame, 3);
+
#ifdef ENABLE_FRAGMENT
/*
* Set frame parameter for fragment code. This is necessary because
diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c
index 80293ef..0bca28d 100644
--- a/src/openvpn/ssl.c
+++ b/src/openvpn/ssl.c
@@ -264,14 +264,16 @@ tls_get_cipher_name_pair (const char * cipher_name,
size_t len) {
return NULL;
}
-/**
- * Max number of bytes we will add for data structures common to both data and
- * control channel packets (1 byte opcode + 3 bytes peer-id).
+/*
+ * Max number of bytes we will add
+ * for data structures common to both
+ * data and control channel packets.
+ * (opcode only).
*/
void
tls_adjust_frame_parameters(struct frame *frame)
{
- frame_add_to_extra_frame (frame, 1 + 3); /* space for opcode + peer-id */
+ frame_add_to_extra_frame (frame, 1); /* space for opcode */
}
/*
--
2.1.2
