[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>

1 files changed, 37 insertions, 1 deletions

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 3c3e560087ca..d8d36dee5ab6 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -78,8 +78,44 @@
 
 #include <asm/uaccess.h>
 
+/* Event handler for inet6 address addition/deletion events.  */
+int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
+                        void *ptr)
+{
+        struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
+        struct sctp_sockaddr_entry *addr;
+        struct list_head *pos, *temp;
+
+        switch (ev) {
+        case NETDEV_UP:
+                addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
+                if (addr) {
+                        addr->a.v6.sin6_family = AF_INET6;
+                        addr->a.v6.sin6_port = 0;
+                        memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
+                                 sizeof(struct in6_addr));
+                        addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
+                        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 (ipv6_addr_equal(&addr->a.v6.sin6_addr, &ifa->addr)) {
+                                list_del(pos);
+                                kfree(addr);
+                                break;
+                        }
+                }
+
+                break;
+        }
+
+        return NOTIFY_DONE;
+}
+
 static struct notifier_block sctp_inet6addr_notifier = {
-        .notifier_call = sctp_inetaddr_event,
+        .notifier_call = sctp_inet6addr_event,
 };
 
 /* ICMP error handler. */