Release 4.11 net/ipv4/netfilter/iptable_mangle.c

/*
 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
 *
 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
 * Copyright (C) 2000-2004 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/module.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/route.h>
#include <linux/ip.h>
#include <net/ip.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("iptables mangle table");


#define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \
                            (1 << NF_INET_LOCAL_IN) | \
                            (1 << NF_INET_FORWARD) | \
                            (1 << NF_INET_LOCAL_OUT) | \
                            (1 << NF_INET_POST_ROUTING))

static int __net_init iptable_mangle_table_init(struct net *net);


static const struct xt_table packet_mangler = {
	.name		= "mangle",
	.valid_hooks	= MANGLE_VALID_HOOKS,
	.me		= THIS_MODULE,
	.af		= NFPROTO_IPV4,
	.priority	= NF_IP_PRI_MANGLE,
	.table_init	= iptable_mangle_table_init,
};


static unsigned int

ipt_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state)
{
	unsigned int ret;
	const struct iphdr *iph;
	u_int8_t tos;
	__be32 saddr, daddr;
	u_int32_t mark;
	int err;

	/* root is playing with raw sockets. */
	if (skb->len < sizeof(struct iphdr) ||
	    ip_hdrlen(skb) < sizeof(struct iphdr))
		return NF_ACCEPT;

	/* Save things which could affect route */
	mark = skb->mark;
	iph = ip_hdr(skb);
	saddr = iph->saddr;
	daddr = iph->daddr;
	tos = iph->tos;

	ret = ipt_do_table(skb, state, state->net->ipv4.iptable_mangle);
	/* Reroute for ANY change. */
	if (ret != NF_DROP && ret != NF_STOLEN) {
		iph = ip_hdr(skb);

		if (iph->saddr != saddr ||
		    iph->daddr != daddr ||
		    skb->mark != mark ||
		    iph->tos != tos) {
			err = ip_route_me_harder(state->net, skb, RTN_UNSPEC);
			if (err < 0)
				ret = NF_DROP_ERR(err);
		}
	}

	return ret;
}

Contributors
Person
Tokens
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Commits
CommitProp
Linus Torvalds (pre-git)
114
58.46%
2
12.50%
Arnaldo Carvalho de Melo
27
13.85%
2
12.50%
Patrick McHardy
17
8.72%
1
6.25%
Herbert Xu
9
4.62%
1
6.25%
Eric W. Biedermann
7
3.59%
2
12.50%
Thomas Graf
6
3.08%
1
6.25%
Simon Horman
5
2.56%
1
6.25%
Alexey Dobriyan
4
2.05%
2
12.50%
David S. Miller
4
2.05%
2
12.50%
Al Viro
1
0.51%
1
6.25%
Jan Engelhardt
1
0.51%
1
6.25%
Total
195
100.00%
16
100.00%

/* The work comes in here from netfilter.c. */

static unsigned int

iptable_mangle_hook(void *priv,
		     struct sk_buff *skb,
		     const struct nf_hook_state *state)
{
	if (state->hook == NF_INET_LOCAL_OUT)
		return ipt_mangle_out(skb, state);
	return ipt_do_table(skb, state, state->net->ipv4.iptable_mangle);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jan Engelhardt
41
75.93%
2
28.57%
David S. Miller
6
11.11%
1
14.29%
Eric W. Biedermann
5
9.26%
3
42.86%
Patrick McHardy
2
3.70%
1
14.29%
Total
54
100.00%
7
100.00%


static struct nf_hook_ops *mangle_ops __read_mostly;


static int __net_init iptable_mangle_table_init(struct net *net)
{
	struct ipt_replace *repl;
	int ret;

	if (net->ipv4.iptable_mangle)
		return 0;

	repl = ipt_alloc_initial_table(&packet_mangler);
	if (repl == NULL)
		return -ENOMEM;
	ret = ipt_register_table(net, &packet_mangler, repl, mangle_ops,
				 &net->ipv4.iptable_mangle);
	kfree(repl);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jan Engelhardt
28
35.90%
1
14.29%
Florian Westphal
26
33.33%
2
28.57%
Alexey Dobriyan
11
14.10%
2
28.57%
Linus Torvalds (pre-git)
11
14.10%
1
14.29%
Harald Welte
2
2.56%
1
14.29%
Total
78
100.00%
7
100.00%



static void __net_exit iptable_mangle_net_exit(struct net *net)
{
	if (!net->ipv4.iptable_mangle)
		return;
	ipt_unregister_table(net, net->ipv4.iptable_mangle, mangle_ops);
	net->ipv4.iptable_mangle = NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Alexey Dobriyan
23
53.49%
2
50.00%
Florian Westphal
20
46.51%
2
50.00%
Total
43
100.00%
4
100.00%


static struct pernet_operations iptable_mangle_net_ops = {
	.exit = iptable_mangle_net_exit,
};



static int __init iptable_mangle_init(void)
{
	int ret;

	mangle_ops = xt_hook_ops_alloc(&packet_mangler, iptable_mangle_hook);
	if (IS_ERR(mangle_ops)) {
		ret = PTR_ERR(mangle_ops);
		return ret;
	}

	ret = register_pernet_subsys(&iptable_mangle_net_ops);
	if (ret < 0) {
		kfree(mangle_ops);
		return ret;
	}

	ret = iptable_mangle_table_init(&init_net);
	if (ret) {
		unregister_pernet_subsys(&iptable_mangle_net_ops);
		kfree(mangle_ops);
	}

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Florian Westphal
45
48.39%
1
14.29%
Alexey Dobriyan
24
25.81%
2
28.57%
Linus Torvalds (pre-git)
10
10.75%
1
14.29%
Jan Engelhardt
9
9.68%
1
14.29%
Linus Torvalds
4
4.30%
1
14.29%
Jean Sacren
1
1.08%
1
14.29%
Total
93
100.00%
7
100.00%



static void __exit iptable_mangle_fini(void)
{
	unregister_pernet_subsys(&iptable_mangle_net_ops);
	kfree(mangle_ops);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
14
70.00%
1
25.00%
Florian Westphal
4
20.00%
1
25.00%
Jan Engelhardt
1
5.00%
1
25.00%
Andrew Morton
1
5.00%
1
25.00%
Total
20
100.00%
4
100.00%


module_init(iptable_mangle_init);

module_exit(iptable_mangle_fini);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
194
31.86%
2
4.88%
Florian Westphal
111
18.23%
2
4.88%
Jan Engelhardt
91
14.94%
7
17.07%
Alexey Dobriyan
75
12.32%
4
9.76%
Arnaldo Carvalho de Melo
30
4.93%
2
4.88%
Patrick McHardy
22
3.61%
5
12.20%
Harald Welte
21
3.45%
3
7.32%
Eric W. Biedermann
12
1.97%
4
9.76%
David S. Miller
10
1.64%
3
7.32%
Art Haas
10
1.64%
1
2.44%
Herbert Xu
9
1.48%
1
2.44%
Thomas Graf
6
0.99%
1
2.44%
Linus Torvalds
5
0.82%
1
2.44%
Simon Horman
5
0.82%
1
2.44%
Andrew Morton
3
0.49%
1
2.44%
Tejun Heo
3
0.49%
1
2.44%
Jean Sacren
1
0.16%
1
2.44%
Al Viro
1
0.16%
1
2.44%
Total
609
100.00%
41
100.00%
Directory: net/ipv4/netfilter

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