Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Martin Schiller <ms@dev.tdt.de>
To:     andrew.hendry@gmail.com, davem@davemloft.net, kuba@kernel.org,
        xie.he.0141@gmail.com
Cc:     linux-x25@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, Martin Schiller <ms@dev.tdt.de>
Subject: [PATCH net-next v3 5/6] net/x25: fix restart request/confirm handling
Date:   Wed, 18 Nov 2020 14:59:18 +0100
Message-ID: <20201118135919.1447-6-ms@dev.tdt.de>
In-Reply-To: <20201118135919.1447-1-ms@dev.tdt.de>
References: <20201118135919.1447-1-ms@dev.tdt.de>
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We have to take the actual link state into account to handle
restart requests/confirms well.

Also, the T20 timer needs to be stopped, if the link is terminated.

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
---
 net/x25/x25_link.c | 45 +++++++++++++++++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 8 deletions(-)

diff --git a/net/x25/x25_link.c b/net/x25/x25_link.c
index 92828a8a4ada..40ffc10f7a96 100644
--- 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,
=20
 	switch (frametype) {
 	case X25_RESTART_REQUEST:
-		confirm =3D !x25_t20timer_pending(nb);
-		x25_stop_t20timer(nb);
-		nb->state =3D X25_LINK_STATE_3;
-		if (confirm)
+		switch (nb->state) {
+		case X25_LINK_STATE_2:
+			confirm =3D !x25_t20timer_pending(nb);
+			x25_stop_t20timer(nb);
+			nb->state =3D 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;
=20
 	case X25_RESTART_CONFIRMATION:
-		x25_stop_t20timer(nb);
-		nb->state =3D X25_LINK_STATE_3;
+		switch (nb->state) {
+		case X25_LINK_STATE_2:
+			if (x25_t20timer_pending(nb)) {
+				x25_stop_t20timer(nb);
+				nb->state =3D 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 =3D X25_LINK_STATE_2;
+			x25_start_t20timer(nb);
+			break;
+		}
 		break;
=20
 	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 =3D X25_LINK_STATE_2;
-		break;
 	case X25_LINK_STATE_1:
 		x25_transmit_restart_request(nb);
 		nb->state =3D X25_LINK_STATE_2;
@@ -232,6 +257,10 @@ void x25_link_established(struct x25_neigh *nb)
 void x25_link_terminated(struct x25_neigh *nb)
 {
 	nb->state =3D X25_LINK_STATE_0;
+
+	if (x25_t20timer_pending(nb))
+		x25_stop_t20timer(nb);
+
 	/* Out of order: clear existing virtual calls (X.25 03/93 4.6.3) */
 	x25_kill_by_neigh(nb);
 }
--=20
2.20.1