session: support half-close connection
Some app(e.g. Envoy) may call shutdown() instead of close() when
draining connection.
Type: improvement
Signed-off-by: liuyacan <liuyacan@corp.netease.com>
Change-Id: I9543b9ca3caa87b10b134fd1fc4019124e41e4d2
diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index 1fac5ed..eba9f64 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -97,9 +97,10 @@
int
session_send_ctrl_evt_to_thread (session_t * s, session_evt_type_t evt_type)
{
- /* only events supported are disconnect and reset */
- ASSERT (evt_type == SESSION_CTRL_EVT_CLOSE
- || evt_type == SESSION_CTRL_EVT_RESET);
+ /* only events supported are disconnect, shutdown and reset */
+ ASSERT (evt_type == SESSION_CTRL_EVT_CLOSE ||
+ evt_type == SESSION_CTRL_EVT_HALF_CLOSE ||
+ evt_type == SESSION_CTRL_EVT_RESET);
return session_send_evt_to_thread (s, 0, s->thread_index, evt_type);
}
@@ -1087,7 +1088,9 @@
return;
/* Transport thinks that app requested close but it actually didn't.
- * Can happen for tcp if fin and rst are received in close succession. */
+ * Can happen for tcp:
+ * 1)if fin and rst are received in close succession.
+ * 2)if app shutdown the connection. */
if (s->session_state == SESSION_STATE_READY)
{
session_transport_closing_notify (tc);
@@ -1399,6 +1402,20 @@
}
/**
+ * Initialize session half-closing procedure.
+ *
+ * Note that half-closing will not change the state of the session.
+ */
+void
+session_half_close (session_t *s)
+{
+ if (!s)
+ return;
+
+ session_program_transport_ctrl_evt (s, SESSION_CTRL_EVT_HALF_CLOSE);
+}
+
+/**
* Initialize session closing procedure.
*
* Request is always sent to session node to ensure that all outstanding
@@ -1439,6 +1456,24 @@
}
/**
+ * Notify transport the session can be half-disconnected.
+ *
+ * Must be called from the session's thread.
+ */
+void
+session_transport_half_close (session_t *s)
+{
+ /* Only READY session can be half-closed */
+ if (s->session_state != SESSION_STATE_READY)
+ {
+ return;
+ }
+
+ transport_half_close (session_get_transport_proto (s), s->connection_index,
+ s->thread_index);
+}
+
+/**
* Notify transport the session can be disconnected. This should eventually
* result in a delete notification that allows us to cleanup session state.
* Called for both active/passive disconnects.