From 7eed751b3b2a6949932a6a59fa2792c584641618 Mon Sep 17 00:00:00 2001 From: Martin Schiller Date: Thu, 26 Nov 2020 07:35:53 +0100 Subject: net/x25: handle additional netdev events 1. Add / remove x25_link_device by NETDEV_REGISTER/UNREGISTER and also by NETDEV_POST_TYPE_CHANGE/NETDEV_PRE_TYPE_CHANGE. This change is needed so that the x25_neigh struct for an interface is already created when it shows up and is kept independently if the interface goes UP or DOWN. This is used in an upcomming commit, where x25 params of an neighbour will get configurable through ioctls. 2. NETDEV_CHANGE event makes it possible to handle carrier loss and detection. If carrier is lost, clean up everything related to this neighbour by calling x25_link_terminated(). 3. Also call x25_link_terminated() for NETDEV_DOWN events and remove the call to x25_clear_forward_by_dev() in x25_route_device_down(), as this is already called by x25_kill_by_neigh() which gets called by x25_link_terminated(). 4. Do nothing for NETDEV_UP and NETDEV_GOING_DOWN events, as these will be handled in layer 2 (LAPB) and layer3 (X.25) will be informed by layer2 when layer2 link is established and layer3 link should be initiated. Signed-off-by: Martin Schiller Signed-off-by: Jakub Kicinski --- net/x25/af_x25.c | 22 ++++++++++++++++------ net/x25/x25_link.c | 6 +++--- net/x25/x25_route.c | 3 --- 3 files changed, 19 insertions(+), 12 deletions(-) diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index a10487e7574c..210829dbda62 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -233,21 +233,31 @@ static int x25_device_event(struct notifier_block *this, unsigned long event, #endif ) { switch (event) { - case NETDEV_UP: + case NETDEV_REGISTER: + case NETDEV_POST_TYPE_CHANGE: x25_link_device_up(dev); break; - case NETDEV_GOING_DOWN: + case NETDEV_DOWN: nb = x25_get_neigh(dev); if (nb) { - x25_terminate_link(nb); + x25_link_terminated(nb); x25_neigh_put(nb); } - break; - case NETDEV_DOWN: - x25_kill_by_device(dev); x25_route_device_down(dev); + break; + case NETDEV_PRE_TYPE_CHANGE: + case NETDEV_UNREGISTER: x25_link_device_down(dev); break; + case NETDEV_CHANGE: + if (!netif_carrier_ok(dev)) { + nb = x25_get_neigh(dev); + if (nb) { + x25_link_terminated(nb); + x25_neigh_put(nb); + } + } + break; } } diff --git a/net/x25/x25_link.c b/net/x25/x25_link.c index fdae054b7dc1..11e868aa625d 100644 --- a/net/x25/x25_link.c +++ b/net/x25/x25_link.c @@ -232,6 +232,9 @@ void x25_link_established(struct x25_neigh *nb) void x25_link_terminated(struct x25_neigh *nb) { nb->state = X25_LINK_STATE_0; + skb_queue_purge(&nb->queue); + x25_stop_t20timer(nb); + /* Out of order: clear existing virtual calls (X.25 03/93 4.6.3) */ x25_kill_by_neigh(nb); } @@ -277,9 +280,6 @@ void x25_link_device_up(struct net_device *dev) */ static void __x25_remove_neigh(struct x25_neigh *nb) { - skb_queue_purge(&nb->queue); - x25_stop_t20timer(nb); - if (nb->node.next) { list_del(&nb->node); x25_neigh_put(nb); diff --git a/net/x25/x25_route.c b/net/x25/x25_route.c index 00e46c9a5280..ec2a39e9b3e6 100644 --- a/net/x25/x25_route.c +++ b/net/x25/x25_route.c @@ -115,9 +115,6 @@ void x25_route_device_down(struct net_device *dev) __x25_remove_route(rt); } write_unlock_bh(&x25_route_list_lock); - - /* Remove any related forwarding */ - x25_clear_forward_by_dev(dev); } /* -- cgit v1.2.3 From a4989fa91110508b64eea7ccde63d062113988ff Mon Sep 17 00:00:00 2001 From: Martin Schiller Date: Thu, 26 Nov 2020 07:35:54 +0100 Subject: net/lapb: support netdev events This patch allows layer2 (LAPB) to react to netdev events itself and avoids the detour via layer3 (X.25). 1. Establish layer2 on NETDEV_UP events, if the carrier is already up. 2. Call lapb_disconnect_request() on NETDEV_GOING_DOWN events to signal the peer that the connection will go down. (Only when the carrier is up.) 3. When a NETDEV_DOWN event occur, clear all queues, enter state LAPB_STATE_0 and stop all timers. 4. The NETDEV_CHANGE event makes it possible to handle carrier loss and detection. In case of Carrier Loss, clear all queues, enter state LAPB_STATE_0 and stop all timers. In case of Carrier Detection, we start timer t1 on a DCE interface, and on a DTE interface we change to state LAPB_STATE_1 and start sending SABM(E). Signed-off-by: Martin Schiller Acked-by: Xie He Signed-off-by: Jakub Kicinski --- net/lapb/lapb_iface.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 81 insertions(+), 1 deletion(-) diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c index 3c03f6512c5f..213ea7abc9ab 100644 --- a/net/lapb/lapb_iface.c +++ b/net/lapb/lapb_iface.c @@ -418,14 +418,94 @@ int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb) return used; } +/* Handle device status changes. */ +static int lapb_device_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct lapb_cb *lapb; + + if (!net_eq(dev_net(dev), &init_net)) + return NOTIFY_DONE; + + if (dev->type != ARPHRD_X25) + return NOTIFY_DONE; + + lapb = lapb_devtostruct(dev); + if (!lapb) + return NOTIFY_DONE; + + switch (event) { + case NETDEV_UP: + lapb_dbg(0, "(%p) Interface up: %s\n", dev, dev->name); + + if (netif_carrier_ok(dev)) { + lapb_dbg(0, "(%p): Carrier is already up: %s\n", dev, + dev->name); + if (lapb->mode & LAPB_DCE) { + lapb_start_t1timer(lapb); + } else { + if (lapb->state == LAPB_STATE_0) { + lapb->state = LAPB_STATE_1; + lapb_establish_data_link(lapb); + } + } + } + break; + case NETDEV_GOING_DOWN: + if (netif_carrier_ok(dev)) + lapb_disconnect_request(dev); + break; + case NETDEV_DOWN: + lapb_dbg(0, "(%p) Interface down: %s\n", dev, dev->name); + lapb_dbg(0, "(%p) S%d -> S0\n", dev, lapb->state); + lapb_clear_queues(lapb); + lapb->state = LAPB_STATE_0; + lapb->n2count = 0; + lapb_stop_t1timer(lapb); + lapb_stop_t2timer(lapb); + break; + case NETDEV_CHANGE: + if (netif_carrier_ok(dev)) { + lapb_dbg(0, "(%p): Carrier detected: %s\n", dev, + dev->name); + if (lapb->mode & LAPB_DCE) { + lapb_start_t1timer(lapb); + } else { + if (lapb->state == LAPB_STATE_0) { + lapb->state = LAPB_STATE_1; + lapb_establish_data_link(lapb); + } + } + } else { + lapb_dbg(0, "(%p) Carrier lost: %s\n", dev, dev->name); + lapb_dbg(0, "(%p) S%d -> S0\n", dev, lapb->state); + lapb_clear_queues(lapb); + lapb->state = LAPB_STATE_0; + lapb->n2count = 0; + lapb_stop_t1timer(lapb); + lapb_stop_t2timer(lapb); + } + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block lapb_dev_notifier = { + .notifier_call = lapb_device_event, +}; + static int __init lapb_init(void) { - return 0; + return register_netdevice_notifier(&lapb_dev_notifier); } static void __exit lapb_exit(void) { WARN_ON(!list_empty(&lapb_list)); + + unregister_netdevice_notifier(&lapb_dev_notifier); } MODULE_AUTHOR("Jonathan Naylor "); -- cgit v1.2.3 From 62480b992ba3fb1d7260b11293aed9d6557831c7 Mon Sep 17 00:00:00 2001 From: Martin Schiller Date: Thu, 26 Nov 2020 07:35:55 +0100 Subject: net/lapb: fix t1 timer handling for LAPB_STATE_0 1. DTE interface changes immediately to LAPB_STATE_1 and start sending SABM(E). 2. DCE interface sends N2-times DM and changes to LAPB_STATE_1 afterwards if there is no response in the meantime. Signed-off-by: Martin Schiller Signed-off-by: Jakub Kicinski --- net/lapb/lapb_timer.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/net/lapb/lapb_timer.c b/net/lapb/lapb_timer.c index 8f5b17001a07..baa247fe4ed0 100644 --- a/net/lapb/lapb_timer.c +++ b/net/lapb/lapb_timer.c @@ -85,11 +85,18 @@ static void lapb_t1timer_expiry(struct timer_list *t) switch (lapb->state) { /* - * If we are a DCE, keep going DM .. DM .. DM + * If we are a DCE, send DM up to N2 times, then switch to + * STATE_1 and send SABM(E). */ case LAPB_STATE_0: - if (lapb->mode & LAPB_DCE) + if (lapb->mode & LAPB_DCE && + lapb->n2count != lapb->n2) { + lapb->n2count++; lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE); + } else { + lapb->state = LAPB_STATE_1; + lapb_establish_data_link(lapb); + } break; /* -- cgit v1.2.3 From d023b2b9ccc2e7ec14b83aec634b5b51f621ef3a Mon Sep 17 00:00:00 2001 From: Martin Schiller Date: Thu, 26 Nov 2020 07:35:56 +0100 Subject: 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 Signed-off-by: Jakub Kicinski --- net/x25/x25_link.c | 41 +++++++++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/net/x25/x25_link.c b/net/x25/x25_link.c index 11e868aa625d..f92073f3cb11 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, 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; -- cgit v1.2.3 From 139d6eb149de0cb8726d0d8e722ab8d4ddcc60bb Mon Sep 17 00:00:00 2001 From: Martin Schiller Date: Thu, 26 Nov 2020 07:35:57 +0100 Subject: net/x25: remove x25_kill_by_device() Remove obsolete function x25_kill_by_device(). It's not used any more. Signed-off-by: Martin Schiller Signed-off-by: Jakub Kicinski --- net/x25/af_x25.c | 16 ---------------- 1 file changed, 16 deletions(-) diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 210829dbda62..9232cdb42ad9 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -199,22 +199,6 @@ static void x25_remove_socket(struct sock *sk) write_unlock_bh(&x25_list_lock); } -/* - * Kill all bound sockets on a dropped device. - */ -static void x25_kill_by_device(struct net_device *dev) -{ - struct sock *s; - - write_lock_bh(&x25_list_lock); - - sk_for_each(s, &x25_list) - if (x25_sk(s)->neighbour && x25_sk(s)->neighbour->dev == dev) - x25_disconnect(s, ENETUNREACH, 0, 0); - - write_unlock_bh(&x25_list_lock); -} - /* * Handle device status changes. */ -- cgit v1.2.3