#include "nf_internals.h"
-/*
+/*
* A queue handler may be registered for each protocol. Each is protected by
* long term mutex. The handler must provide an an outfn() to accept packets
* for queueing and must reinject all packets it receives, no matter what.
*/
static struct nf_queue_handler *queue_handler[NPROTO];
-static DEFINE_RWLOCK(queue_handler_lock);
+static DEFINE_MUTEX(queue_handler_mutex);
/* return EBUSY when somebody else is registered, return EEXIST if the
* same handler is registered, return 0 in case of success. */
int nf_register_queue_handler(int pf, struct nf_queue_handler *qh)
-{
+{
int ret;
if (pf >= NPROTO)
return -EINVAL;
- write_lock_bh(&queue_handler_lock);
+ mutex_lock(&queue_handler_mutex);
if (queue_handler[pf] == qh)
ret = -EEXIST;
else if (queue_handler[pf])
ret = -EBUSY;
else {
- queue_handler[pf] = qh;
+ rcu_assign_pointer(queue_handler[pf], qh);
ret = 0;
}
- write_unlock_bh(&queue_handler_lock);
+ mutex_unlock(&queue_handler_mutex);
return ret;
}
EXPORT_SYMBOL(nf_register_queue_handler);
/* The caller must flush their queue before this */
-int nf_unregister_queue_handler(int pf)
+int nf_unregister_queue_handler(int pf, struct nf_queue_handler *qh)
{
if (pf >= NPROTO)
return -EINVAL;
- write_lock_bh(&queue_handler_lock);
- queue_handler[pf] = NULL;
- write_unlock_bh(&queue_handler_lock);
-
+ mutex_lock(&queue_handler_mutex);
+ if (queue_handler[pf] != qh) {
+ mutex_unlock(&queue_handler_mutex);
+ return -EINVAL;
+ }
+
+ rcu_assign_pointer(queue_handler[pf], NULL);
+ mutex_unlock(&queue_handler_mutex);
+
+ synchronize_rcu();
+
return 0;
}
EXPORT_SYMBOL(nf_unregister_queue_handler);
{
int pf;
- write_lock_bh(&queue_handler_lock);
+ mutex_lock(&queue_handler_mutex);
for (pf = 0; pf < NPROTO; pf++) {
if (queue_handler[pf] == qh)
- queue_handler[pf] = NULL;
+ rcu_assign_pointer(queue_handler[pf], NULL);
}
- write_unlock_bh(&queue_handler_lock);
+ mutex_unlock(&queue_handler_mutex);
+
+ synchronize_rcu();
}
EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
-/*
- * Any packet that leaves via this function must come back
+/*
+ * Any packet that leaves via this function must come back
* through nf_reinject().
*/
static int __nf_queue(struct sk_buff *skb,
struct net_device *physoutdev = NULL;
#endif
struct nf_afinfo *afinfo;
+ struct nf_queue_handler *qh;
/* QUEUE == DROP if noone is waiting, to be safe. */
- read_lock(&queue_handler_lock);
- if (!queue_handler[pf]) {
- read_unlock(&queue_handler_lock);
+ rcu_read_lock();
+
+ qh = rcu_dereference(queue_handler[pf]);
+ if (!qh) {
+ rcu_read_unlock();
kfree_skb(skb);
return 1;
}
afinfo = nf_get_afinfo(pf);
if (!afinfo) {
- read_unlock(&queue_handler_lock);
+ rcu_read_unlock();
kfree_skb(skb);
return 1;
}
if (net_ratelimit())
printk(KERN_ERR "OOM queueing packet %p\n",
skb);
- read_unlock(&queue_handler_lock);
+ rcu_read_unlock();
kfree_skb(skb);
return 1;
}
- *info = (struct nf_info) {
+ *info = (struct nf_info) {
(struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn };
/* If it's going away, ignore hook. */
if (!try_module_get(info->elem->owner)) {
- read_unlock(&queue_handler_lock);
+ rcu_read_unlock();
kfree(info);
return 0;
}
}
#endif
afinfo->saveroute(skb, info);
- status = queue_handler[pf]->outfn(skb, info, queuenum,
- queue_handler[pf]->data);
+ status = qh->outfn(skb, info, queuenum, qh->data);
- read_unlock(&queue_handler_lock);
+ rcu_read_unlock();
if (status < 0) {
/* James M doesn't say fuck enough. */
module_put(info->elem->owner);
list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) {
- if (i == elem)
- break;
- }
-
+ if (i == elem)
+ break;
+ }
+
if (i == &nf_hooks[info->pf][info->hook]) {
/* The module which sent it to userspace is gone. */
NFDEBUG("%s: module disappeared, dropping packet.\n",
if (verdict == NF_ACCEPT) {
next_hook:
verdict = nf_iterate(&nf_hooks[info->pf][info->hook],
- &skb, info->hook,
+ &skb, info->hook,
info->indev, info->outdev, &elem,
info->okfn, INT_MIN);
}
loff_t *pos = v;
struct nf_queue_handler *qh;
- read_lock_bh(&queue_handler_lock);
- qh = queue_handler[*pos];
+ rcu_read_lock();
+ qh = rcu_dereference(queue_handler[*pos]);
if (!qh)
ret = seq_printf(s, "%2lld NONE\n", *pos);
else
ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
- read_unlock_bh(&queue_handler_lock);
+ rcu_read_unlock();
return ret;
}
-static struct seq_operations nfqueue_seq_ops = {
+static const struct seq_operations nfqueue_seq_ops = {
.start = seq_start,
.next = seq_next,
.stop = seq_stop,
return seq_open(file, &nfqueue_seq_ops);
}
-static struct file_operations nfqueue_file_ops = {
+static const struct file_operations nfqueue_file_ops = {
.owner = THIS_MODULE,
.open = nfqueue_open,
.read = seq_read,