[PATCH pve-http-server v2 1/1] fix unexpected EOF for client when closing TLS session

[Rob Rozestraten]

When pve-http-server initiates the closure of a TLS session, it does not
send a TLS close notify, resulting in an unexpected EOF error on systems
with recent crypto policies. This can break functionality with other
applications, such as Foreman[0].

This behavior can be observed in the following cases:

 * client uses HTTP/1.0 (no keepalive; server closes connection)
 * client sends no data for 5 sec (timeout; server closes connection)
 * server responds with 400 (no keepalive; server closes connection)

This patch sends the TLS close notify prior to socket teardown,
resulting in clean closure of TLS connections and no client error.

It also moves shutdown() to after the clearing of handlers. The reason
for this is stoptls() must come before shutdown(), but it also triggers
on_drain(), which calls client_do_disconnect() again. The extra call to
client_do_disconnect() is avoided inside accept_connections() by commit
f737984, but perhaps clearing the handlers prior to shutdown() will
avoid it in all cases.

[0]: https://github.com/theforeman/foreman_fog_proxmox/issues/325

Signed-off-by: Rob Rozestraten <admin at truthsolo.net>
---

 changes since v1:
 * move stoptls() after clearing of handlers
 * move shutdown() after clearing of handlers

 src/PVE/APIServer/AnyEvent.pm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/PVE/APIServer/AnyEvent.pm b/src/PVE/APIServer/AnyEvent.pm
index 8a52836..e6d1028 100644
--- a/src/PVE/APIServer/AnyEvent.pm
+++ b/src/PVE/APIServer/AnyEvent.pm
@@ -141,11 +141,13 @@ sub client_do_disconnect {
     my $shutdown_hdl = sub {
 	my $hdl = shift;
 
-	shutdown($hdl->{fh}, 1);
 	# clear all handlers
 	$hdl->on_drain(undef);
 	$hdl->on_read(undef);
 	$hdl->on_eof(undef);
+
+	$hdl->stoptls();
+	shutdown($hdl->{fh}, 1);
     };
 
     if (my $proxyhdl = delete $reqstate->{proxyhdl}) {
-- 
2.48.1