diff options
Diffstat (limited to 'net/llc/llc_input.c')
| -rw-r--r-- | net/llc/llc_input.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/net/llc/llc_input.c b/net/llc/llc_input.c index 058f1e9a912..dd3e83328ad 100644 --- a/net/llc/llc_input.c +++ b/net/llc/llc_input.c @@ -13,6 +13,7 @@ */ #include <linux/netdevice.h> #include <linux/slab.h> +#include <linux/export.h> #include <net/net_namespace.h> #include <net/llc.h> #include <net/llc_pdu.h> @@ -41,6 +42,7 @@ static void (*llc_type_handlers[2])(struct llc_sap *sap, void llc_add_pack(int type, void (*handler)(struct llc_sap *sap, struct sk_buff *skb)) { + smp_wmb(); /* ensure initialisation is complete before it's called */ if (type == LLC_DEST_SAP || type == LLC_DEST_CONN) llc_type_handlers[type - 1] = handler; } @@ -49,11 +51,19 @@ void llc_remove_pack(int type) { if (type == LLC_DEST_SAP || type == LLC_DEST_CONN) llc_type_handlers[type - 1] = NULL; + synchronize_net(); } void llc_set_station_handler(void (*handler)(struct sk_buff *skb)) { + /* Ensure initialisation is complete before it's called */ + if (handler) + smp_wmb(); + llc_station_handler = handler; + + if (!handler) + synchronize_net(); } /** @@ -121,8 +131,7 @@ static inline int llc_fixup_skb(struct sk_buff *skb) s32 data_size = ntohs(pdulen) - llc_len; if (data_size < 0 || - ((skb_tail_pointer(skb) - - (u8 *)pdu) - llc_len) < data_size) + !pskb_may_pull(skb, data_size)) return 0; if (unlikely(pskb_trim_rcsum(skb, data_size))) return 0; @@ -150,6 +159,8 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev, int dest; int (*rcv)(struct sk_buff *, struct net_device *, struct packet_type *, struct net_device *); + void (*sta_handler)(struct sk_buff *skb); + void (*sap_handler)(struct llc_sap *sap, struct sk_buff *skb); if (!net_eq(dev_net(dev), &init_net)) goto drop; @@ -182,7 +193,8 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev, */ rcv = rcu_dereference(sap->rcv_func); dest = llc_pdu_type(skb); - if (unlikely(!dest || !llc_type_handlers[dest - 1])) { + sap_handler = dest ? ACCESS_ONCE(llc_type_handlers[dest - 1]) : NULL; + if (unlikely(!sap_handler)) { if (rcv) rcv(skb, dev, pt, orig_dev); else @@ -193,7 +205,7 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev, if (cskb) rcv(cskb, dev, pt, orig_dev); } - llc_type_handlers[dest - 1](sap, skb); + sap_handler(sap, skb); } llc_sap_put(sap); out: @@ -202,9 +214,10 @@ drop: kfree_skb(skb); goto out; handle_station: - if (!llc_station_handler) + sta_handler = ACCESS_ONCE(llc_station_handler); + if (!sta_handler) goto drop; - llc_station_handler(skb); + sta_handler(skb); goto out; } |