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
--- a/net/netfilter/ipset/ip_set_bitmap_gen.h
+++ b/net/netfilter/ipset/ip_set_bitmap_gen.h
@@ -144,10 +144,12 @@
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 @@
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 @@
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 @@
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 @@
/* 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 @@
/* 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 @@
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
--- a/net/netfilter/ipset/ip_set_bitmap_ip.c
+++ b/net/netfilter/ipset/ip_set_bitmap_ip.c
@@ -81,7 +81,7 @@
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 @@
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
--- a/net/netfilter/ipset/ip_set_bitmap_ipmac.c
+++ b/net/netfilter/ipset/ip_set_bitmap_ipmac.c
@@ -147,15 +147,23 @@
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 @@
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
--- a/net/netfilter/ipset/ip_set_bitmap_port.c
+++ b/net/netfilter/ipset/ip_set_bitmap_port.c
@@ -73,7 +73,7 @@
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 @@
static void __exit
bitmap_port_fini(void)
{
+ rcu_barrier();
ip_set_type_unregister(&bitmap_port_type);
}