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Commit f1585086 authored by Florian Westphal's avatar Florian Westphal Committed by Patrick McHardy
Browse files

netfilter: nfnetlink_queue: return error number to caller 



instead of returning -1 on error, return an error number to allow the
caller to handle some errors differently.

ECANCELED is used to indicate that the hook is going away and should be
ignored.

A followup patch will introduce more 'ignore this hook' conditions,
(depending on queue settings) and will move kfree_skb responsibility
to the caller.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 5f2cafe7

net/netfilter/core.c

+4 −2
Original line number Diff line number Diff line
@@ -179,9 +179,11 @@ next_hook: 
		if (ret == 0)

			ret = -EPERM;

	} else if ((verdict & NF_VERDICT_MASK) == NF_QUEUE) {

		if (!nf_queue(skb, elem, pf, hook, indev, outdev, okfn,

			      verdict >> NF_VERDICT_BITS))

		ret = nf_queue(skb, elem, pf, hook, indev, outdev, okfn,

			       verdict >> NF_VERDICT_BITS);

		if (ret == -ECANCELED)

			goto next_hook;

		ret = 0;

	}

	rcu_read_unlock();

	return ret;

net/netfilter/nf_queue.c

+31 −13
Original line number Diff line number Diff line
@@ -125,7 +125,7 @@ static int __nf_queue(struct sk_buff *skb, 
		      int (*okfn)(struct sk_buff *),

		      unsigned int queuenum)

{

	int status;

	int status = -ENOENT;

	struct nf_queue_entry *entry = NULL;

#ifdef CONFIG_BRIDGE_NETFILTER

	struct net_device *physindev;
@@ -146,8 +146,10 @@ static int __nf_queue(struct sk_buff *skb, 
		goto err_unlock;



	entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC);

	if (!entry)

	if (!entry) {

		status = -ENOMEM;

		goto err_unlock;

	}



	*entry = (struct nf_queue_entry) {

		.skb	= skb,
@@ -163,9 +165,8 @@ static int __nf_queue(struct sk_buff *skb, 
	if (!try_module_get(entry->elem->owner)) {

		rcu_read_unlock();

		kfree(entry);

		return 0;

		return -ECANCELED;

	}



	/* Bump dev refs so they don't vanish while packet is out */

	if (indev)

		dev_hold(indev);
@@ -192,14 +193,14 @@ static int __nf_queue(struct sk_buff *skb, 
		goto err;

	}



	return 1;

	return 0;



err_unlock:

	rcu_read_unlock();

err:

	kfree_skb(skb);

	kfree(entry);

	return 1;

	return status;

}



int nf_queue(struct sk_buff *skb,
@@ -211,6 +212,8 @@ int nf_queue(struct sk_buff *skb, 
	     unsigned int queuenum)

{

	struct sk_buff *segs;

	int err;

	unsigned int queued;



	if (!skb_is_gso(skb))

		return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
@@ -227,19 +230,32 @@ int nf_queue(struct sk_buff *skb, 


	segs = skb_gso_segment(skb, 0);

	kfree_skb(skb);

	/* Does not use PTR_ERR to limit the number of error codes that can be

	 * returned by nf_queue.  For instance, callers rely on -ECANCELED to mean

	 * 'ignore this hook'.

	 */

	if (IS_ERR(segs))

		return 1;

		return -EINVAL;



	queued = 0;

	err = 0;

	do {

		struct sk_buff *nskb = segs->next;



		segs->next = NULL;

		if (!__nf_queue(segs, elem, pf, hook, indev, outdev, okfn,

				queuenum))

		if (err == 0)

			err = __nf_queue(segs, elem, pf, hook, indev,

					   outdev, okfn, queuenum);

		if (err == 0)

			queued++;

		else

			kfree_skb(segs);

		segs = nskb;

	} while (segs);

	return 1;



	if (unlikely(err && queued))

		err = 0;

	return err;

}



void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
@@ -247,6 +263,7 @@ void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) 
	struct sk_buff *skb = entry->skb;

	struct list_head *elem = &entry->elem->list;

	const struct nf_afinfo *afinfo;

	int err;



	rcu_read_lock();
@@ -280,9 +297,10 @@ void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) 
		local_bh_enable();

		break;

	case NF_QUEUE:

		if (!__nf_queue(skb, elem, entry->pf, entry->hook,

		err = __nf_queue(skb, elem, entry->pf, entry->hook,

				 entry->indev, entry->outdev, entry->okfn,

				verdict >> NF_VERDICT_BITS))

				 verdict >> NF_VERDICT_BITS);

		if (err == -ECANCELED)

			goto next_hook;

		break;

	case NF_STOLEN:

net/netfilter/nfnetlink_queue.c

+14 −8
Original line number Diff line number Diff line
@@ -387,25 +387,31 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum) 
{

	struct sk_buff *nskb;

	struct nfqnl_instance *queue;

	int err;

	int err = -ENOBUFS;



	/* rcu_read_lock()ed by nf_hook_slow() */

	queue = instance_lookup(queuenum);

	if (!queue)

	if (!queue) {

		err = -ESRCH;

		goto err_out;

	}



	if (queue->copy_mode == NFQNL_COPY_NONE)

	if (queue->copy_mode == NFQNL_COPY_NONE) {

		err = -EINVAL;

		goto err_out;

	}



	nskb = nfqnl_build_packet_message(queue, entry);

	if (nskb == NULL)

	if (nskb == NULL) {

		err = -ENOMEM;

		goto err_out;



	}

	spin_lock_bh(&queue->lock);



	if (!queue->peer_pid)

	if (!queue->peer_pid) {

		err = -EINVAL;

		goto err_out_free_nskb;



	}

	if (queue->queue_total >= queue->queue_maxlen) {

		queue->queue_dropped++;

		if (net_ratelimit())
@@ -432,7 +438,7 @@ err_out_free_nskb: 
err_out_unlock:

	spin_unlock_bh(&queue->lock);

err_out:

	return -1;

	return err;

}



static int