netfilter: ipset: Introduce RCU locking in bitmap:* types

There's nothing much required because the bitmap types use atomic
bit operations. However the logic of adding elements slightly changed:
first the MAC address updated (which is not atomic), then the element
activated (added). The extensions may call kfree_rcu() therefore we
call rcu_barrier() at module removal.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

diff --git a/net/netfilter/ipset/ip_set_bitmap_gen.h b/net/netfilter/ipset/ip_set_bitmap_gen.h
index 6f024a8..86429f3 100644 (file)
--- a/net/netfilter/ipset/ip_set_bitmap_gen.h
+++ b/net/netfilter/ipset/ip_set_bitmap_gen.h
@@ -144,10 +144,12 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
 
        if (ret == IPSET_ADD_FAILED) {
                if (SET_WITH_TIMEOUT(set) &&
-                   ip_set_timeout_expired(ext_timeout(x, set)))
+                   ip_set_timeout_expired(ext_timeout(x, set))) {
                        ret = 0;
-               else if (!(flags & IPSET_FLAG_EXIST))
+               } else if (!(flags & IPSET_FLAG_EXIST)) {
+                       set_bit(e->id, map->members);
                        return -IPSET_ERR_EXIST;
+               }
                /* Element is re-added, cleanup extensions */
                ip_set_ext_destroy(set, x);
        }
@@ -165,6 +167,10 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
                ip_set_init_comment(ext_comment(x, set), ext);
        if (SET_WITH_SKBINFO(set))
                ip_set_init_skbinfo(ext_skbinfo(x, set), ext);
+
+       /* Activate element */
+       set_bit(e->id, map->members);
+
        return 0;
 }
 
@@ -203,10 +209,13 @@ mtype_list(const struct ip_set *set,
        struct nlattr *adt, *nested;
        void *x;
        u32 id, first = cb->args[IPSET_CB_ARG0];
+       int ret = 0;
 
        adt = ipset_nest_start(skb, IPSET_ATTR_ADT);
        if (!adt)
                return -EMSGSIZE;
+       /* Extensions may be replaced */
+       rcu_read_lock();
        for (; cb->args[IPSET_CB_ARG0] < map->elements;
             cb->args[IPSET_CB_ARG0]++) {
                id = cb->args[IPSET_CB_ARG0];
@@ -222,9 +231,11 @@ mtype_list(const struct ip_set *set,
                if (!nested) {
                        if (id == first) {
                                nla_nest_cancel(skb, adt);
-                               return -EMSGSIZE;
-                       } else
-                               goto nla_put_failure;
+                               ret = -EMSGSIZE;
+                               goto out;
+                       }
+
+                       goto nla_put_failure;
                }
                if (mtype_do_list(skb, map, id, set->dsize))
                        goto nla_put_failure;
@@ -238,16 +249,18 @@ mtype_list(const struct ip_set *set,
        /* Set listing finished */
        cb->args[IPSET_CB_ARG0] = 0;
 
-       return 0;
+       goto out;
 
 nla_put_failure:
        nla_nest_cancel(skb, nested);
        if (unlikely(id == first)) {
                cb->args[IPSET_CB_ARG0] = 0;
-               return -EMSGSIZE;
+               ret = -EMSGSIZE;
        }
        ipset_nest_end(skb, adt);
-       return 0;
+out:
+       rcu_read_unlock();
+       return ret;
 }
 
 static void
@@ -260,7 +273,7 @@ mtype_gc(unsigned long ul_set)
 
        /* We run parallel with other readers (test element)
         * but adding/deleting new entries is locked out */
-       read_lock_bh(&set->lock);
+       spin_lock_bh(&set->lock);
        for (id = 0; id < map->elements; id++)
                if (mtype_gc_test(id, map, set->dsize)) {
                        x = get_ext(set, map, id);
@@ -269,7 +282,7 @@ mtype_gc(unsigned long ul_set)
                                ip_set_ext_destroy(set, x);
                        }
                }
-       read_unlock_bh(&set->lock);
+       spin_unlock_bh(&set->lock);
 
        map->gc.expires = jiffies + IPSET_GC_PERIOD(set->timeout) * HZ;
        add_timer(&map->gc);

diff --git a/net/netfilter/ipset/ip_set_bitmap_ip.c b/net/netfilter/ipset/ip_set_bitmap_ip.c
index 7af99c3..b8ce474 100644 (file)
--- a/net/netfilter/ipset/ip_set_bitmap_ip.c
+++ b/net/netfilter/ipset/ip_set_bitmap_ip.c
@@ -81,7 +81,7 @@ static inline int
 bitmap_ip_do_add(const struct bitmap_ip_adt_elem *e, struct bitmap_ip *map,
                 u32 flags, size_t dsize)
 {
-       return !!test_and_set_bit(e->id, map->members);
+       return !!test_bit(e->id, map->members);
 }
 
 static inline int
@@ -376,6 +376,7 @@ bitmap_ip_init(void)
 static void __exit
 bitmap_ip_fini(void)
 {
+       rcu_barrier();
        ip_set_type_unregister(&bitmap_ip_type);
 }
 

diff --git a/net/netfilter/ipset/ip_set_bitmap_ipmac.c b/net/netfilter/ipset/ip_set_bitmap_ipmac.c
index 7733422..fe00e87 100644 (file)
--- a/net/netfilter/ipset/ip_set_bitmap_ipmac.c
+++ b/net/netfilter/ipset/ip_set_bitmap_ipmac.c
@@ -147,15 +147,23 @@ bitmap_ipmac_do_add(const struct bitmap_ipmac_adt_elem *e,
        struct bitmap_ipmac_elem *elem;
 
        elem = get_elem(map->extensions, e->id, dsize);
-       if (test_and_set_bit(e->id, map->members)) {
+       if (test_bit(e->id, map->members)) {
                if (elem->filled == MAC_FILLED) {
-                       if (e->ether && (flags & IPSET_FLAG_EXIST))
+                       if (e->ether &&
+                           (flags & IPSET_FLAG_EXIST) &&
+                           !ether_addr_equal(e->ether, elem->ether)) {
+                               /* memcpy isn't atomic */
+                               clear_bit(e->id, map->members);
+                               smp_mb__after_atomic();
                                memcpy(elem->ether, e->ether, ETH_ALEN);
+                       }
                        return IPSET_ADD_FAILED;
                } else if (!e->ether)
                        /* Already added without ethernet address */
                        return IPSET_ADD_FAILED;
                /* Fill the MAC address and trigger the timer activation */
+               clear_bit(e->id, map->members);
+               smp_mb__after_atomic();
                memcpy(elem->ether, e->ether, ETH_ALEN);
                elem->filled = MAC_FILLED;
                return IPSET_ADD_START_STORED_TIMEOUT;
@@ -413,6 +421,7 @@ bitmap_ipmac_init(void)
 static void __exit
 bitmap_ipmac_fini(void)
 {
+       rcu_barrier();
        ip_set_type_unregister(&bitmap_ipmac_type);
 }
 

diff --git a/net/netfilter/ipset/ip_set_bitmap_port.c b/net/netfilter/ipset/ip_set_bitmap_port.c
index ec3bda1..2d360f9 100644 (file)
--- a/net/netfilter/ipset/ip_set_bitmap_port.c
+++ b/net/netfilter/ipset/ip_set_bitmap_port.c
@@ -73,7 +73,7 @@ static inline int
 bitmap_port_do_add(const struct bitmap_port_adt_elem *e,
                   struct bitmap_port *map, u32 flags, size_t dsize)
 {
-       return !!test_and_set_bit(e->id, map->members);
+       return !!test_bit(e->id, map->members);
 }
 
 static inline int
@@ -306,6 +306,7 @@ bitmap_port_init(void)
 static void __exit
 bitmap_port_fini(void)
 {
+       rcu_barrier();
        ip_set_type_unregister(&bitmap_port_type);
 }