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[NETFILTER]: nfnetlink_queue: deobfuscate entry lookups

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A queue entry lookup currently looks like this:

find_dequeue_entry -> __find_dequeue_entry ->
	__find_entry -> cmpfn -> id_cmp

Use simple open-coded list walking and kill the cmpfn for
find_dequeue_entry. Instead add it to nfqnl_flush (after
similar cleanups) and use nfqnl_flush for both complete
flushes and flushing entries related to a device.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2007-12-05 01:25:30 -08:00 committed by David S. Miller
parent 0ac41e8146
commit b43d8d8598
1 changed files with 31 additions and 69 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

100
net/netfilter/nfnetlink_queue.c
View file

@ -171,7 +171,8 @@ out_unlock:
return NULL;
}
static void nfqnl_flush(struct nfqnl_instance *queue, int verdict);
static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
unsigned long data);
static void
_instance_destroy2(struct nfqnl_instance *inst, int lock)
@ -188,7 +189,7 @@ _instance_destroy2(struct nfqnl_instance *inst, int lock)
write_unlock_bh(&instances_lock);
/* then flush all pending skbs from the queue */
nfqnl_flush(inst, NF_DROP);
nfqnl_flush(inst, NULL, 0);
/* and finally put the refcount */
instance_put(inst);
@ -235,54 +236,6 @@ __enqueue_entry(struct nfqnl_instance *queue,
queue->queue_total++;
}
/*
* Find and return a queued entry matched by cmpfn, or return the last
* entry if cmpfn is NULL.
*/
static inline struct nfqnl_queue_entry *
__find_entry(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
unsigned long data)
{
struct nfqnl_queue_entry *entry;
list_for_each_entry(entry, &queue->queue_list, list) {
if (!cmpfn || cmpfn(entry, data))
return entry;
}
return NULL;
}
static inline void
__dequeue_entry(struct nfqnl_instance *q, struct nfqnl_queue_entry *entry)
{
list_del(&entry->list);
q->queue_total--;
}
static inline struct nfqnl_queue_entry *
__find_dequeue_entry(struct nfqnl_instance *queue,
nfqnl_cmpfn cmpfn, unsigned long data)
{
struct nfqnl_queue_entry *entry;
entry = __find_entry(queue, cmpfn, data);
if (entry == NULL)
return NULL;
__dequeue_entry(queue, entry);
return entry;
}
static inline void
__nfqnl_flush(struct nfqnl_instance *queue, int verdict)
{
struct nfqnl_queue_entry *entry;
while ((entry = __find_dequeue_entry(queue, NULL, 0)))
issue_verdict(entry, verdict);
}
static inline int
__nfqnl_set_mode(struct nfqnl_instance *queue,
unsigned char mode, unsigned int range)
@ -313,23 +266,42 @@ __nfqnl_set_mode(struct nfqnl_instance *queue,
}
static struct nfqnl_queue_entry *
find_dequeue_entry(struct nfqnl_instance *queue,
nfqnl_cmpfn cmpfn, unsigned long data)
find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
{
struct nfqnl_queue_entry *entry;
struct nfqnl_queue_entry *entry = NULL, *i;
spin_lock_bh(&queue->lock);
entry = __find_dequeue_entry(queue, cmpfn, data);
list_for_each_entry(i, &queue->queue_list, list) {
if (i->id == id) {
entry = i;
break;
}
}
if (entry) {
list_del(&entry->list);
queue->queue_total--;
}
spin_unlock_bh(&queue->lock);
return entry;
}
static void
nfqnl_flush(struct nfqnl_instance *queue, int verdict)
nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
{
struct nfqnl_queue_entry *entry, *next;
spin_lock_bh(&queue->lock);
__nfqnl_flush(queue, verdict);
list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
if (!cmpfn || cmpfn(entry, data)) {
list_del(&entry->list);
queue->queue_total--;
issue_verdict(entry, NF_DROP);
}
}
spin_unlock_bh(&queue->lock);
}
@ -644,12 +616,6 @@ nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e)
return 0;
}
static inline int
id_cmp(struct nfqnl_queue_entry *e, unsigned long id)
{
return (id == e->id);
}
static int
nfqnl_set_mode(struct nfqnl_instance *queue,
unsigned char mode, unsigned int range)
@ -706,12 +672,8 @@ nfqnl_dev_drop(int ifindex)
struct nfqnl_instance *inst;
struct hlist_head *head = &instance_table[i];
hlist_for_each_entry(inst, tmp, head, hlist) {
struct nfqnl_queue_entry *entry;
while ((entry = find_dequeue_entry(inst, dev_cmp,
ifindex)) != NULL)
issue_verdict(entry, NF_DROP);
}
hlist_for_each_entry(inst, tmp, head, hlist)
nfqnl_flush(inst, dev_cmp, ifindex);
}
read_unlock_bh(&instances_lock);
@ -811,7 +773,7 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
goto err_out_put;
}
entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id));
entry = find_dequeue_entry(queue, ntohl(vhdr->id));
if (entry == NULL) {
err = -ENOENT;
goto err_out_put;