Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[pandora-kernel.git] / net / sctp / protocol.c
index 34bab36..3d036cd 100644 (file)
@@ -153,6 +153,9 @@ static void sctp_v4_copy_addrlist(struct list_head *addrlist,
                        addr->a.v4.sin_family = AF_INET;
                        addr->a.v4.sin_port = 0;
                        addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
+                       addr->valid = 1;
+                       INIT_LIST_HEAD(&addr->list);
+                       INIT_RCU_HEAD(&addr->rcu);
                        list_add_tail(&addr->list, addrlist);
                }
        }
@@ -192,16 +195,24 @@ static void sctp_free_local_addr_list(void)
        }
 }
 
+void sctp_local_addr_free(struct rcu_head *head)
+{
+       struct sctp_sockaddr_entry *e = container_of(head,
+                               struct sctp_sockaddr_entry, rcu);
+       kfree(e);
+}
+
 /* 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, *temp;
 
-       list_for_each_safe(pos, temp, &sctp_local_addr_list) {
-               addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+       rcu_read_lock();
+       list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
+               if (!addr->valid)
+                       continue;
                if (sctp_in_scope(&addr->a, scope)) {
                        /* Now that the address is in scope, check to see if
                         * the address type is really supported by the local
@@ -213,7 +224,7 @@ int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
                              (copy_flags & SCTP_ADDR6_ALLOWED) &&
                              (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
                                error = sctp_add_bind_addr(bp, &addr->a, 1,
-                                                          GFP_ATOMIC);
+                                                   GFP_ATOMIC);
                                if (error)
                                        goto end_copy;
                        }
@@ -221,6 +232,7 @@ int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
        }
 
 end_copy:
+       rcu_read_unlock();
        return error;
 }
 
@@ -416,9 +428,7 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
        struct rtable *rt;
        struct flowi fl;
        struct sctp_bind_addr *bp;
-       rwlock_t *addr_lock;
        struct sctp_sockaddr_entry *laddr;
-       struct list_head *pos;
        struct dst_entry *dst = NULL;
        union sctp_addr dst_saddr;
 
@@ -447,23 +457,20 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
                goto out;
 
        bp = &asoc->base.bind_addr;
-       addr_lock = &asoc->base.addr_lock;
 
        if (dst) {
                /* Walk through the bind address list and look for a bind
                 * address that matches the source address of the returned dst.
                 */
-               sctp_read_lock(addr_lock);
-               list_for_each(pos, &bp->address_list) {
-                       laddr = list_entry(pos, struct sctp_sockaddr_entry,
-                                          list);
-                       if (!laddr->use_as_src)
+               rcu_read_lock();
+               list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+                       if (!laddr->valid || !laddr->use_as_src)
                                continue;
                        sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port));
                        if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
                                goto out_unlock;
                }
-               sctp_read_unlock(addr_lock);
+               rcu_read_unlock();
 
                /* None of the bound addresses match the source address of the
                 * dst. So release it.
@@ -475,10 +482,10 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
        /* Walk through the bind address list and try to get a dst that
         * matches a bind address as the source address.
         */
-       sctp_read_lock(addr_lock);
-       list_for_each(pos, &bp->address_list) {
-               laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
-
+       rcu_read_lock();
+       list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+               if (!laddr->valid)
+                       continue;
                if ((laddr->use_as_src) &&
                    (AF_INET == laddr->a.sa.sa_family)) {
                        fl.fl4_src = laddr->a.v4.sin_addr.s_addr;
@@ -490,7 +497,7 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
        }
 
 out_unlock:
-       sctp_read_unlock(addr_lock);
+       rcu_read_unlock();
 out:
        if (dst)
                SCTP_DEBUG_PRINTK("rt_dst:%u.%u.%u.%u, rt_src:%u.%u.%u.%u\n",
@@ -600,13 +607,18 @@ static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
        seq_printf(seq, "%d.%d.%d.%d ", NIPQUAD(addr->v4.sin_addr));
 }
 
-/* Event handler for inet address addition/deletion events.  */
+/* Event handler for inet address addition/deletion events.
+ * The sctp_local_addr_list needs to be protocted by a spin lock since
+ * multiple notifiers (say IPv4 and IPv6) may be running at the same
+ * time and thus corrupt the list.
+ * The reader side is protected with RCU.
+ */
 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
                               void *ptr)
 {
        struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
-       struct sctp_sockaddr_entry *addr;
-       struct list_head *pos, *temp;
+       struct sctp_sockaddr_entry *addr = NULL;
+       struct sctp_sockaddr_entry *temp;
 
        switch (ev) {
        case NETDEV_UP:
@@ -615,19 +627,25 @@ static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
                        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);
+                       addr->valid = 1;
+                       spin_lock_bh(&sctp_local_addr_lock);
+                       list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
+                       spin_unlock_bh(&sctp_local_addr_lock);
                }
                break;
        case NETDEV_DOWN:
-               list_for_each_safe(pos, temp, &sctp_local_addr_list) {
-                       addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+               spin_lock_bh(&sctp_local_addr_lock);
+               list_for_each_entry_safe(addr, temp,
+                                       &sctp_local_addr_list, list) {
                        if (addr->a.v4.sin_addr.s_addr == ifa->ifa_local) {
-                               list_del(pos);
-                               kfree(addr);
+                               addr->valid = 0;
+                               list_del_rcu(&addr->list);
                                break;
                        }
                }
-
+               spin_unlock_bh(&sctp_local_addr_lock);
+               if (addr && !addr->valid)
+                       call_rcu(&addr->rcu, sctp_local_addr_free);
                break;
        }
 
@@ -980,14 +998,14 @@ SCTP_STATIC __init int sctp_init(void)
        sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
                                               sizeof(struct sctp_bind_bucket),
                                               0, SLAB_HWCACHE_ALIGN,
-                                              NULL, NULL);
+                                              NULL);
        if (!sctp_bucket_cachep)
                goto out;
 
        sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
                                               sizeof(struct sctp_chunk),
                                               0, SLAB_HWCACHE_ALIGN,
-                                              NULL, NULL);
+                                              NULL);
        if (!sctp_chunk_cachep)
                goto err_chunk_cachep;
 
@@ -1160,6 +1178,7 @@ SCTP_STATIC __init int sctp_init(void)
 
        /* 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. */
@@ -1227,6 +1246,9 @@ SCTP_STATIC __exit void sctp_exit(void)
        sctp_v6_del_protocol();
        inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
 
+       /* Unregister notifier for inet address additions/deletions. */
+       unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
+
        /* Free the local address list.  */
        sctp_free_local_addr_list();
 
@@ -1240,9 +1262,6 @@ SCTP_STATIC __exit void sctp_exit(void)
        inet_unregister_protosw(&sctp_stream_protosw);
        inet_unregister_protosw(&sctp_seqpacket_protosw);
 
-       /* Unregister notifier for inet address additions/deletions. */
-       unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
-
        sctp_sysctl_unregister();
        list_del(&sctp_ipv4_specific.list);