net/x25: fix restart request/confirm handling

We have to take the actual link state into account to handle
restart requests/confirms well.

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/x25/x25_link.c b/net/x25/x25_link.c
index 11e868aa625d68d0f7c7e0415b5569671f126ea0..f92073f3cb11e21c11b69bf2d4478cf51943e60c 100644 (file)
--- a/net/x25/x25_link.c
+++ b/net/x25/x25_link.c
@@ -74,16 +74,43 @@ void x25_link_control(struct sk_buff *skb, struct x25_neigh *nb,
 
        switch (frametype) {
        case X25_RESTART_REQUEST:
-               confirm = !x25_t20timer_pending(nb);
-               x25_stop_t20timer(nb);
-               nb->state = X25_LINK_STATE_3;
-               if (confirm)
+               switch (nb->state) {
+               case X25_LINK_STATE_2:
+                       confirm = !x25_t20timer_pending(nb);
+                       x25_stop_t20timer(nb);
+                       nb->state = X25_LINK_STATE_3;
+                       if (confirm)
+                               x25_transmit_restart_confirmation(nb);
+                       break;
+               case X25_LINK_STATE_3:
+                       /* clear existing virtual calls */
+                       x25_kill_by_neigh(nb);
+
                        x25_transmit_restart_confirmation(nb);
+                       break;
+               }
                break;
 
        case X25_RESTART_CONFIRMATION:
-               x25_stop_t20timer(nb);
-               nb->state = X25_LINK_STATE_3;
+               switch (nb->state) {
+               case X25_LINK_STATE_2:
+                       if (x25_t20timer_pending(nb)) {
+                               x25_stop_t20timer(nb);
+                               nb->state = X25_LINK_STATE_3;
+                       } else {
+                               x25_transmit_restart_request(nb);
+                               x25_start_t20timer(nb);
+                       }
+                       break;
+               case X25_LINK_STATE_3:
+                       /* clear existing virtual calls */
+                       x25_kill_by_neigh(nb);
+
+                       x25_transmit_restart_request(nb);
+                       nb->state = X25_LINK_STATE_2;
+                       x25_start_t20timer(nb);
+                       break;
+               }
                break;
 
        case X25_DIAGNOSTIC:
@@ -214,8 +241,6 @@ void x25_link_established(struct x25_neigh *nb)
 {
        switch (nb->state) {
        case X25_LINK_STATE_0:
-               nb->state = X25_LINK_STATE_2;
-               break;
        case X25_LINK_STATE_1:
                x25_transmit_restart_request(nb);
                nb->state = X25_LINK_STATE_2;