cregit-Linux how code gets into the kernel

Release 4.10 net/ipv4/netfilter/nf_defrag_ipv4.c

Directory: net/ipv4/netfilter
/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/types.h>
#include <linux/ip.h>
#include <linux/netfilter.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <net/netns/generic.h>
#include <net/route.h>
#include <net/ip.h>

#include <linux/netfilter_bridge.h>
#include <linux/netfilter_ipv4.h>
#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
#include <net/netfilter/nf_conntrack.h>
#endif
#include <net/netfilter/nf_conntrack_zones.h>

static DEFINE_MUTEX(defrag4_mutex);




static int nf_ct_ipv4_gather_frags(struct net *net, struct sk_buff *skb,
				   u_int32_t user)
{
	int err;

	local_bh_disable();
	err = ip_defrag(net, skb, user);
	local_bh_enable();

	if (!err)
		skb->ignore_df = 1;

	return err;
}


Contributors
PersonTokensPropCommitsCommitProp
kovacs krisztiankovacs krisztian4075.47%125.00%


eric w. biedermaneric w. biederman713.21%125.00%


florian westphalflorian westphal59.43%125.00%


americo wangamerico wang11.89%125.00%


Total53100.00%4100.00%






static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
					      struct sk_buff *skb)
{
	u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
	if (skb->nfct) {
		enum ip_conntrack_info ctinfo;
		const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);

		zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo));
	}
#endif
	if (nf_bridge_in_prerouting(skb))
		return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id;

	if (hooknum == NF_INET_PRE_ROUTING)
		return IP_DEFRAG_CONNTRACK_IN + zone_id;
	else
		return IP_DEFRAG_CONNTRACK_OUT + zone_id;
}


Contributors
PersonTokensPropCommitsCommitProp
patrick mchardypatrick mchardy6060.61%342.86%


daniel borkmanndaniel borkmann3535.35%228.57%


florian westphalflorian westphal33.03%114.29%


duan jiongduan jiong11.01%114.29%


Total99100.00%7100.00%






static unsigned int ipv4_conntrack_defrag(void *priv,
					  struct sk_buff *skb,
					  const struct nf_hook_state *state)
{
	struct sock *sk = skb->sk;

	if (sk && sk_fullsock(sk) && (sk->sk_family == PF_INET) &&
	    inet_sk(sk)->nodefrag)
		return NF_ACCEPT;

#if IS_ENABLED(CONFIG_NF_CONNTRACK)
#if !IS_ENABLED(CONFIG_NF_NAT)
	/* Previously seen (loopback)?  Ignore.  Do this before
           fragment check. */
	if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
		return NF_ACCEPT;
#endif
#endif
	/* Gather fragments. */
	if (ip_is_fragment(ip_hdr(skb))) {
		enum ip_defrag_users user =
			nf_ct_defrag_user(state->hook, skb);

		if (nf_ct_ipv4_gather_frags(state->net, skb, user))
			return NF_STOLEN;
	}
	return NF_ACCEPT;
}


Contributors
PersonTokensPropCommitsCommitProp
kovacs krisztiankovacs krisztian5941.26%17.14%


patrick mchardypatrick mchardy3423.78%428.57%


jiri olsajiri olsa2718.88%214.29%


eric dumazeteric dumazet96.29%17.14%


eric w. biedermaneric w. biederman85.59%321.43%


david s. millerdavid s. miller21.40%17.14%


paul gortmakerpaul gortmaker21.40%17.14%


duan jiongduan jiong21.40%17.14%


Total143100.00%14100.00%




static struct nf_hook_ops ipv4_defrag_ops[] = {
	{
		.hook		= ipv4_conntrack_defrag,
		.pf		= NFPROTO_IPV4,
		.hooknum	= NF_INET_PRE_ROUTING,
		.priority	= NF_IP_PRI_CONNTRACK_DEFRAG,
        },
	{
		.hook           = ipv4_conntrack_defrag,
		.pf             = NFPROTO_IPV4,
		.hooknum        = NF_INET_LOCAL_OUT,
		.priority       = NF_IP_PRI_CONNTRACK_DEFRAG,
        },
};




static void __net_exit defrag4_net_exit(struct net *net)
{
	if (net->nf.defrag_ipv4) {
		nf_unregister_net_hooks(net, ipv4_defrag_ops,
					ARRAY_SIZE(ipv4_defrag_ops));
		net->nf.defrag_ipv4 = false;
	}
}


Contributors
PersonTokensPropCommitsCommitProp
florian westphalflorian westphal3071.43%150.00%


kovacs krisztiankovacs krisztian1228.57%150.00%


Total42100.00%2100.00%




static struct pernet_operations defrag4_net_ops = {
	.exit = defrag4_net_exit,
};




static int __init nf_defrag_init(void)
{
	return register_pernet_subsys(&defrag4_net_ops);
}


Contributors
PersonTokensPropCommitsCommitProp
florian westphalflorian westphal1487.50%150.00%


kovacs krisztiankovacs krisztian212.50%150.00%


Total16100.00%2100.00%






static void __exit nf_defrag_fini(void)
{
	unregister_pernet_subsys(&defrag4_net_ops);
}


Contributors
PersonTokensPropCommitsCommitProp
kovacs krisztiankovacs krisztian1280.00%150.00%


florian westphalflorian westphal320.00%150.00%


Total15100.00%2100.00%






int nf_defrag_ipv4_enable(struct net *net)
{
	int err = 0;

	might_sleep();

	if (net->nf.defrag_ipv4)
		return 0;

	mutex_lock(&defrag4_mutex);
	if (net->nf.defrag_ipv4)
		goto out_unlock;

	err = nf_register_net_hooks(net, ipv4_defrag_ops,
				    ARRAY_SIZE(ipv4_defrag_ops));
	if (err == 0)
		net->nf.defrag_ipv4 = true;

 out_unlock:
	mutex_unlock(&defrag4_mutex);
	return err;
}

Contributors
PersonTokensPropCommitsCommitProp
florian westphalflorian westphal8296.47%150.00%


kovacs krisztiankovacs krisztian33.53%150.00%


Total85100.00%2100.00%




EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);


module_init(nf_defrag_init);

module_exit(nf_defrag_fini);

MODULE_LICENSE("GPL");

Overall Contributors
PersonTokensPropCommitsCommitProp
kovacs krisztiankovacs krisztian22538.07%14.17%


florian westphalflorian westphal16027.07%416.67%


patrick mchardypatrick mchardy10918.44%625.00%


daniel borkmanndaniel borkmann355.92%28.33%


jiri olsajiri olsa274.57%28.33%


eric w. biedermaneric w. biederman152.54%312.50%


eric dumazeteric dumazet91.52%14.17%


duan jiongduan jiong40.68%14.17%


alban crequyalban crequy20.34%14.17%


david s. millerdavid s. miller20.34%14.17%


paul gortmakerpaul gortmaker20.34%14.17%


americo wangamerico wang10.17%14.17%


Total591100.00%24100.00%


Directory: net/ipv4/netfilter



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