WAN: protect Cisco HDLC state changes with a spinlock.

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/net/wan/hdlc_cisco.c b/drivers/net/wan/hdlc_cisco.c
index 7133c68..762d21c 100644 (file)
--- a/drivers/net/wan/hdlc_cisco.c
+++ b/drivers/net/wan/hdlc_cisco.c
@@ -56,6 +56,7 @@ struct cisco_state {
        cisco_proto settings;
 
        struct timer_list timer;
+       spinlock_t lock;
        unsigned long last_poll;
        int up;
        int request_sent;
@@ -158,6 +159,7 @@ static int cisco_rx(struct sk_buff *skb)
 {
        struct net_device *dev = skb->dev;
        hdlc_device *hdlc = dev_to_hdlc(dev);
+       struct cisco_state *st = state(hdlc);
        struct hdlc_header *data = (struct hdlc_header*)skb->data;
        struct cisco_packet *cisco_data;
        struct in_device *in_dev;
@@ -220,11 +222,12 @@ static int cisco_rx(struct sk_buff *skb)
                        goto rx_error;
 
                case CISCO_KEEPALIVE_REQ:
-                       state(hdlc)->rxseq = ntohl(cisco_data->par1);
-                       if (state(hdlc)->request_sent &&
-                           ntohl(cisco_data->par2) == state(hdlc)->txseq) {
-                               state(hdlc)->last_poll = jiffies;
-                               if (!state(hdlc)->up) {
+                       spin_lock(&st->lock);
+                       st->rxseq = ntohl(cisco_data->par1);
+                       if (st->request_sent &&
+                           ntohl(cisco_data->par2) == st->txseq) {
+                               st->last_poll = jiffies;
+                               if (!st->up) {
                                        u32 sec, min, hrs, days;
                                        sec = ntohl(cisco_data->time) / 1000;
                                        min = sec / 60; sec -= min * 60;
@@ -232,12 +235,12 @@ static int cisco_rx(struct sk_buff *skb)
                                        days = hrs / 24; hrs -= days * 24;
                                        printk(KERN_INFO "%s: Link up (peer "
                                               "uptime %ud%uh%um%us)\n",
-                                              dev->name, days, hrs,
-                                              min, sec);
+                                              dev->name, days, hrs, min, sec);
                                        netif_dormant_off(dev);
-                                       state(hdlc)->up = 1;
+                                       st->up = 1;
                                }
                        }
+                       spin_unlock(&st->lock);
 
                        dev_kfree_skb_any(skb);
                        return NET_RX_SUCCESS;
@@ -261,24 +264,25 @@ static void cisco_timer(unsigned long arg)
 {
        struct net_device *dev = (struct net_device *)arg;
        hdlc_device *hdlc = dev_to_hdlc(dev);
+       struct cisco_state *st = state(hdlc);
 
-       if (state(hdlc)->up &&
-           time_after(jiffies, state(hdlc)->last_poll +
-                      state(hdlc)->settings.timeout * HZ)) {
-               state(hdlc)->up = 0;
+       spin_lock(&st->lock);
+       if (st->up &&
+           time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
+               st->up = 0;
                printk(KERN_INFO "%s: Link down\n", dev->name);
                netif_dormant_on(dev);
        }
 
-       cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ,
-                            htonl(++state(hdlc)->txseq),
-                            htonl(state(hdlc)->rxseq));
-       state(hdlc)->request_sent = 1;
-       state(hdlc)->timer.expires = jiffies +
-               state(hdlc)->settings.interval * HZ;
-       state(hdlc)->timer.function = cisco_timer;
-       state(hdlc)->timer.data = arg;
-       add_timer(&state(hdlc)->timer);
+       cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
+                            htonl(st->rxseq));
+       st->request_sent = 1;
+       spin_unlock(&st->lock);
+
+       st->timer.expires = jiffies + st->settings.interval * HZ;
+       st->timer.function = cisco_timer;
+       st->timer.data = arg;
+       add_timer(&st->timer);
 }
 
 
@@ -286,15 +290,20 @@ static void cisco_timer(unsigned long arg)
 static void cisco_start(struct net_device *dev)
 {
        hdlc_device *hdlc = dev_to_hdlc(dev);
-       state(hdlc)->up = 0;
-       state(hdlc)->request_sent = 0;
-       state(hdlc)->txseq = state(hdlc)->rxseq = 0;
-
-       init_timer(&state(hdlc)->timer);
-       state(hdlc)->timer.expires = jiffies + HZ; /*First poll after 1s*/
-       state(hdlc)->timer.function = cisco_timer;
-       state(hdlc)->timer.data = (unsigned long)dev;
-       add_timer(&state(hdlc)->timer);
+       struct cisco_state *st = state(hdlc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&st->lock, flags);
+       st->up = 0;
+       st->request_sent = 0;
+       st->txseq = st->rxseq = 0;
+       spin_unlock_irqrestore(&st->lock, flags);
+
+       init_timer(&st->timer);
+       st->timer.expires = jiffies + HZ; /* First poll after 1 s */
+       st->timer.function = cisco_timer;
+       st->timer.data = (unsigned long)dev;
+       add_timer(&st->timer);
 }
 
 
@@ -302,10 +311,16 @@ static void cisco_start(struct net_device *dev)
 static void cisco_stop(struct net_device *dev)
 {
        hdlc_device *hdlc = dev_to_hdlc(dev);
-       del_timer_sync(&state(hdlc)->timer);
+       struct cisco_state *st = state(hdlc);
+       unsigned long flags;
+
+       del_timer_sync(&st->timer);
+
+       spin_lock_irqsave(&st->lock, flags);
        netif_dormant_on(dev);
-       state(hdlc)->up = 0;
-       state(hdlc)->request_sent = 0;
+       st->up = 0;
+       st->request_sent = 0;
+       spin_unlock_irqrestore(&st->lock, flags);
 }
 
 
@@ -367,6 +382,7 @@ static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
                        return result;
 
                memcpy(&state(hdlc)->settings, &new_settings, size);
+               spin_lock_init(&state(hdlc)->lock);
                dev->hard_start_xmit = hdlc->xmit;
                dev->header_ops = &cisco_header_ops;
                dev->type = ARPHRD_CISCO;