RDMA: Delete keepalive timer on closing (#1237)

Typically, RDMA connection gets closed by client side, the server side
handles diconnected CM event, and delete keepalive timer correctly.
However, the server side may close connection voluntarily, for example
the maxium connections exceed. Handle this case to avoid invalid memory
access.

Signed-off-by: zhenwei pi <[email protected]>

src/rdma.c

@@ -451,13 +451,22 @@ static int rdmaHandleEstablished(struct rdma_cm_event *ev) {
     return C_OK;
 }
 
+static inline void rdmaDelKeepalive(aeEventLoop *el, RdmaContext *ctx) {
+    if (ctx->keepalive_te == AE_ERR) {
+        return;
+    }
+
+    aeDeleteTimeEvent(el, ctx->keepalive_te);
+    ctx->keepalive_te = AE_ERR;
+}
+
 static int rdmaHandleDisconnect(aeEventLoop *el, struct rdma_cm_event *ev) {
     struct rdma_cm_id *cm_id = ev->id;
     RdmaContext *ctx = cm_id->context;
     connection *conn = ctx->conn;
     rdma_connection *rdma_conn = (rdma_connection *)conn;
 
-    aeDeleteTimeEvent(el, ctx->keepalive_te);
+    rdmaDelKeepalive(el, ctx);
     conn->state = CONN_STATE_CLOSED;
 
     /* we can't close connection now, let's mark this connection as closed state */
@@ -1173,6 +1182,7 @@ static void connRdmaClose(connection *conn) {
     }
 
     ctx = cm_id->context;
+    rdmaDelKeepalive(server.el, ctx);
     rdma_disconnect(cm_id);
 
     /* poll all CQ before close */