[SCTP]: Handle address add/delete events in a more efficient way.
Currently in SCTP, we maintain a local address list by rebuilding the whole
list from the device list whenever we get a address add/delete event.
This patch fixes it by only adding/deleting the address for which we
receive the event.
Also removed the sctp_local_addr_lock() which is no longer needed as we
now use list_for_each_safe() to traverse this list. This fixes the bugs
in sctp_copy_laddrs_xxx() routines where we do copy_to_user() while
holding this lock.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index f2ba861..b61f334 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -163,7 +163,7 @@
/* Extract our IP addresses from the system and stash them in the
* protocol structure.
*/
-static void __sctp_get_local_addr_list(void)
+static void sctp_get_local_addr_list(void)
{
struct net_device *dev;
struct list_head *pos;
@@ -179,17 +179,8 @@
read_unlock(&dev_base_lock);
}
-static void sctp_get_local_addr_list(void)
-{
- unsigned long flags;
-
- sctp_spin_lock_irqsave(&sctp_local_addr_lock, flags);
- __sctp_get_local_addr_list();
- sctp_spin_unlock_irqrestore(&sctp_local_addr_lock, flags);
-}
-
/* Free the existing local addresses. */
-static void __sctp_free_local_addr_list(void)
+static void sctp_free_local_addr_list(void)
{
struct sctp_sockaddr_entry *addr;
struct list_head *pos, *temp;
@@ -201,27 +192,15 @@
}
}
-/* Free the existing local addresses. */
-static void sctp_free_local_addr_list(void)
-{
- unsigned long flags;
-
- sctp_spin_lock_irqsave(&sctp_local_addr_lock, flags);
- __sctp_free_local_addr_list();
- sctp_spin_unlock_irqrestore(&sctp_local_addr_lock, flags);
-}
-
/* Copy the local addresses which are valid for 'scope' into 'bp'. */
int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
gfp_t gfp, int copy_flags)
{
struct sctp_sockaddr_entry *addr;
int error = 0;
- struct list_head *pos;
- unsigned long flags;
+ struct list_head *pos, *temp;
- sctp_spin_lock_irqsave(&sctp_local_addr_lock, flags);
- list_for_each(pos, &sctp_local_addr_list) {
+ list_for_each_safe(pos, temp, &sctp_local_addr_list) {
addr = list_entry(pos, struct sctp_sockaddr_entry, list);
if (sctp_in_scope(&addr->a, scope)) {
/* Now that the address is in scope, check to see if
@@ -242,7 +221,6 @@
}
end_copy:
- sctp_spin_unlock_irqrestore(&sctp_local_addr_lock, flags);
return error;
}
@@ -622,18 +600,36 @@
seq_printf(seq, "%d.%d.%d.%d ", NIPQUAD(addr->v4.sin_addr));
}
-/* Event handler for inet address addition/deletion events.
- * Basically, whenever there is an event, we re-build our local address list.
- */
+/* Event handler for inet address addition/deletion events. */
int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
void *ptr)
{
- unsigned long flags;
+ struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
+ struct sctp_sockaddr_entry *addr;
+ struct list_head *pos, *temp;
- sctp_spin_lock_irqsave(&sctp_local_addr_lock, flags);
- __sctp_free_local_addr_list();
- __sctp_get_local_addr_list();
- sctp_spin_unlock_irqrestore(&sctp_local_addr_lock, flags);
+ switch (ev) {
+ case NETDEV_UP:
+ addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
+ if (addr) {
+ addr->a.v4.sin_family = AF_INET;
+ addr->a.v4.sin_port = 0;
+ addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
+ list_add_tail(&addr->list, &sctp_local_addr_list);
+ }
+ break;
+ case NETDEV_DOWN:
+ list_for_each_safe(pos, temp, &sctp_local_addr_list) {
+ addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+ if (addr->a.v4.sin_addr.s_addr == ifa->ifa_local) {
+ list_del(pos);
+ kfree(addr);
+ break;
+ }
+ }
+
+ break;
+ }
return NOTIFY_DONE;
}
@@ -1172,13 +1168,12 @@
/* Initialize the local address list. */
INIT_LIST_HEAD(&sctp_local_addr_list);
- spin_lock_init(&sctp_local_addr_lock);
+
+ sctp_get_local_addr_list();
/* Register notifier for inet address additions/deletions. */
register_inetaddr_notifier(&sctp_inetaddr_notifier);
- sctp_get_local_addr_list();
-
__unsafe(THIS_MODULE);
status = 0;
out: