cregit-Linux how code gets into the kernel

Release 4.8 net/netfilter/nf_queue.c

Directory: net/netfilter
/*
 * Rusty Russell (C)2000 -- This code is GPL.
 * Patrick McHardy (c) 2006-2012
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#include <linux/netfilter_bridge.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
#include <net/protocol.h>
#include <net/netfilter/nf_queue.h>
#include <net/dst.h>

#include "nf_internals.h"

/*
 * Hook for nfnetlink_queue to register its queue handler.
 * We do this so that most of the NFQUEUE code can be modular.
 *
 * Once the queue is registered it must reinject all packets it
 * receives, no matter what.
 */

/* return EBUSY when somebody else is registered, return EEXIST if the
 * same handler is registered, return 0 in case of success. */



void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh)
{
	/* should never happen, we only have one queueing backend in kernel */
	WARN_ON(rcu_access_pointer(net->nf.queue_handler));
	rcu_assign_pointer(net->nf.queue_handler, qh);
}

Contributors
PersonTokensPropCommitsCommitProp
harald welteharald welte1435.00%225.00%


eric w. biedermaneric w. biederman1332.50%112.50%


eric dumazeteric dumazet512.50%225.00%


florian westphalflorian westphal410.00%112.50%


yasuyuki kozakaiyasuyuki kozakai37.50%112.50%


patrick mchardypatrick mchardy12.50%112.50%


Total40100.00%8100.00%




EXPORT_SYMBOL(nf_register_queue_handler);

/* The caller must flush their queue before this */



void nf_unregister_queue_handler(struct net *net)
{
	RCU_INIT_POINTER(net->nf.queue_handler, NULL);
}

Contributors
PersonTokensPropCommitsCommitProp
harald welteharald welte838.10%120.00%


eric w. biedermaneric w. biederman838.10%120.00%


yasuyuki kozakaiyasuyuki kozakai314.29%120.00%


stephen hemmingerstephen hemminger14.76%120.00%


florian westphalflorian westphal14.76%120.00%


Total21100.00%5100.00%




EXPORT_SYMBOL(nf_unregister_queue_handler);




void nf_queue_entry_release_refs(struct nf_queue_entry *entry)
{
	struct nf_hook_state *state = &entry->state;

	/* Release those devices we held, or Alexey will kill me. */
	if (state->in)
		dev_put(state->in);
	if (state->out)
		dev_put(state->out);
	if (state->sk)
		sock_put(state->sk);
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
	if (entry->skb->nf_bridge) {
		struct net_device *physdev;

		physdev = nf_bridge_get_physindev(entry->skb);
		if (physdev)
			dev_put(physdev);
		physdev = nf_bridge_get_physoutdev(entry->skb);
		if (physdev)
			dev_put(physdev);
	}
#endif
}

Contributors
PersonTokensPropCommitsCommitProp
patrick mchardypatrick mchardy6453.78%120.00%


david s. millerdavid s. miller2924.37%240.00%


florian westphalflorian westphal2117.65%120.00%


pablo neira ayusopablo neira ayuso54.20%120.00%


Total119100.00%5100.00%




EXPORT_SYMBOL_GPL(nf_queue_entry_release_refs);

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



void nf_queue_entry_get_refs(struct nf_queue_entry *entry)
{
	struct nf_hook_state *state = &entry->state;

	if (state->in)
		dev_hold(state->in);
	if (state->out)
		dev_hold(state->out);
	if (state->sk)
		sock_hold(state->sk);
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
	if (entry->skb->nf_bridge) {
		struct net_device *physdev;

		physdev = nf_bridge_get_physindev(entry->skb);
		if (physdev)
			dev_hold(physdev);
		physdev = nf_bridge_get_physoutdev(entry->skb);
		if (physdev)
			dev_hold(physdev);
	}
#endif
}

Contributors
PersonTokensPropCommitsCommitProp
florian westphalflorian westphal8471.19%350.00%


david s. millerdavid s. miller2924.58%233.33%


pablo neira ayusopablo neira ayuso54.24%116.67%


Total118100.00%6100.00%




EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs);




void nf_queue_nf_hook_drop(struct net *net, struct nf_hook_ops *ops)
{
	const struct nf_queue_handler *qh;

	rcu_read_lock();
	qh = rcu_dereference(net->nf.queue_handler);
	if (qh)
		qh->nf_hook_drop(net, ops);
	rcu_read_unlock();
}


Contributors
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eric w. biedermaneric w. biederman4690.20%266.67%


pablo neira ayusopablo neira ayuso59.80%133.33%


Total51100.00%3100.00%



/*
 * Any packet that leaves via this function must come back
 * through nf_reinject().
 */



int nf_queue(struct sk_buff *skb,
	     struct nf_hook_ops *elem,
	     struct nf_hook_state *state,
	     unsigned int queuenum)
{
	int status = -ENOENT;
	struct nf_queue_entry *entry = NULL;
	const struct nf_afinfo *afinfo;
	const struct nf_queue_handler *qh;
	struct net *net = state->net;

	/* QUEUE == DROP if no one is waiting, to be safe. */
	qh = rcu_dereference(net->nf.queue_handler);
	if (!qh) {
		status = -ESRCH;
		goto err;
	}

	afinfo = nf_get_afinfo(state->pf);
	if (!afinfo)
		goto err;

	entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC);
	if (!entry) {
		status = -ENOMEM;
		goto err;
	}

	*entry = (struct nf_queue_entry) {
		.skb	= skb,
		.elem	= elem,
		.state	= *state,
		.size	= sizeof(*entry) + afinfo->route_key_size,
        };

	nf_queue_entry_get_refs(entry);
	skb_dst_force(skb);
	afinfo->saveroute(skb, entry);
	status = qh->outfn(entry, queuenum);

	if (status < 0) {
		nf_queue_entry_release_refs(entry);
		goto err;
	}

	return 0;

err:
	kfree(entry);
	return status;
}


Contributors
PersonTokensPropCommitsCommitProp
harald welteharald welte8938.53%29.09%


patrick mchardypatrick mchardy6628.57%731.82%


florian westphalflorian westphal3816.45%627.27%


eric w. biedermaneric w. biederman135.63%14.55%


yasuyuki kozakaiyasuyuki kozakai114.76%14.55%


david s. millerdavid s. miller73.03%29.09%


eric dumazeteric dumazet52.16%14.55%


lucas de marchilucas de marchi10.43%14.55%


michael wangmichael wang10.43%14.55%


Total231100.00%22100.00%






void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
{
	struct sk_buff *skb = entry->skb;
	struct nf_hook_ops *elem = entry->elem;
	const struct nf_afinfo *afinfo;
	int err;

	nf_queue_entry_release_refs(entry);

	/* Continue traversal iff userspace said ok... */
	if (verdict == NF_REPEAT)
		verdict = elem->hook(elem->priv, skb, &entry->state);

	if (verdict == NF_ACCEPT) {
		afinfo = nf_get_afinfo(entry->state.pf);
		if (!afinfo || afinfo->reroute(entry->state.net, skb, entry) < 0)
			verdict = NF_DROP;
	}

	entry->state.thresh = INT_MIN;

	if (verdict == NF_ACCEPT) {
	next_hook:
		verdict = nf_iterate(entry->state.hook_list,
				     skb, &entry->state, &elem);
	}

	switch (verdict & NF_VERDICT_MASK) {
	case NF_ACCEPT:
	case NF_STOP:
		local_bh_disable();
		entry->state.okfn(entry->state.net, entry->state.sk, skb);
		local_bh_enable();
		break;
	case NF_QUEUE:
		err = nf_queue(skb, elem, &entry->state,
			       verdict >> NF_VERDICT_QBITS);
		if (err < 0) {
			if (err == -ESRCH &&
			   (verdict & NF_VERDICT_FLAG_QUEUE_BYPASS))
				goto next_hook;
			kfree_skb(skb);
		}
		break;
	case NF_STOLEN:
		break;
	default:
		kfree_skb(skb);
	}

	kfree(entry);
}

Contributors
PersonTokensPropCommitsCommitProp
harald welteharald welte9837.26%14.35%


patrick mchardypatrick mchardy7227.38%730.43%


florian westphalflorian westphal4717.87%626.09%


david s. millerdavid s. miller249.13%313.04%


eric w. biedermaneric w. biederman134.94%313.04%


michael wangmichael wang51.90%14.35%


eric dumazeteric dumazet31.14%14.35%


julian anastasovjulian anastasov10.38%14.35%


Total263100.00%23100.00%




EXPORT_SYMBOL(nf_reinject);

Overall Contributors
PersonTokensPropCommitsCommitProp
harald welteharald welte25327.62%36.25%


florian westphalflorian westphal21022.93%1122.92%


patrick mchardypatrick mchardy21022.93%1122.92%


eric w. biedermaneric w. biederman9310.15%510.42%


david s. millerdavid s. miller899.72%48.33%


yasuyuki kozakaiyasuyuki kozakai171.86%12.08%


eric dumazeteric dumazet161.75%48.33%


pablo neira ayusopablo neira ayuso151.64%24.17%


michael wangmichael wang60.66%24.17%


tejun heotejun heo30.33%12.08%


hideaki yoshifujihideaki yoshifuji10.11%12.08%


stephen hemmingerstephen hemminger10.11%12.08%


julian anastasovjulian anastasov10.11%12.08%


lucas de marchilucas de marchi10.11%12.08%


Total916100.00%48100.00%

  
Directory: net/netfilter



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