[deliverable/linux.git] / net / ipv4 / netfilter / arptable_filter.c

/*
 * Filtering ARP tables module.
 *
 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
 *
 */

#include <linux/module.h>
#include <linux/netfilter_arp/arp_tables.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
MODULE_DESCRIPTION("arptables filter table");

#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \
			   (1 << NF_ARP_FORWARD))

/* Standard entry. */
struct arpt_standard
{
	struct arpt_entry entry;
	struct arpt_standard_target target;
};

struct arpt_error_target
{
	struct arpt_entry_target target;
	char errorname[ARPT_FUNCTION_MAXNAMELEN];
};

struct arpt_error
{
	struct arpt_entry entry;
	struct arpt_error_target target;
};

static struct
{
	struct arpt_replace repl;
	struct arpt_standard entries[3];
	struct arpt_error term;
} initial_table __initdata
= { { "filter", FILTER_VALID_HOOKS, 4,
      sizeof(struct arpt_standard) * 3 + sizeof(struct arpt_error),
      { [NF_ARP_IN] = 0,
	[NF_ARP_OUT] = sizeof(struct arpt_standard),
	[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), },
      { [NF_ARP_IN] = 0,
	[NF_ARP_OUT] = sizeof(struct arpt_standard),
	[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), },
      0, NULL, { } },
    {
	    /* ARP_IN */
	    {
		    {
			    {
				    { 0 }, { 0 }, { 0 }, { 0 },
				    0, 0,
				    { { 0, }, { 0, } },
				    { { 0, }, { 0, } },
				    0, 0,
				    0, 0,
				    0, 0,
				    "", "", { 0 }, { 0 },
				    0, 0
			    },
			    sizeof(struct arpt_entry),
			    sizeof(struct arpt_standard),
			    0,
			    { 0, 0 }, { } },
		    { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
		      -NF_ACCEPT - 1 }
	    },
	    /* ARP_OUT */
	    {
		    {
			    {
				    { 0 }, { 0 }, { 0 }, { 0 },
				    0, 0,
				    { { 0, }, { 0, } },
				    { { 0, }, { 0, } },
				    0, 0,
				    0, 0,
				    0, 0,
				    "", "", { 0 }, { 0 },
				    0, 0
			    },
			    sizeof(struct arpt_entry),
			    sizeof(struct arpt_standard),
			    0,
			    { 0, 0 }, { } },
		    { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
		      -NF_ACCEPT - 1 }
	    },
	    /* ARP_FORWARD */
	    {
		    {
			    {
				    { 0 }, { 0 }, { 0 }, { 0 },
				    0, 0,
				    { { 0, }, { 0, } },
				    { { 0, }, { 0, } },
				    0, 0,
				    0, 0,
				    0, 0,
				    "", "", { 0 }, { 0 },
				    0, 0
			    },
			    sizeof(struct arpt_entry),
			    sizeof(struct arpt_standard),
			    0,
			    { 0, 0 }, { } },
		    { { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
		      -NF_ACCEPT - 1 }
	    }
    },
    /* ERROR */
    {
	    {
		    {
			    { 0 }, { 0 }, { 0 }, { 0 },
			    0, 0,
			    { { 0, }, { 0, } },
			    { { 0, }, { 0, } },
			    0, 0,
			    0, 0,
			    0, 0,
			    "", "", { 0 }, { 0 },
			    0, 0
		    },
		    sizeof(struct arpt_entry),
		    sizeof(struct arpt_error),
		    0,
		    { 0, 0 }, { } },
	    { { { { ARPT_ALIGN(sizeof(struct arpt_error_target)), ARPT_ERROR_TARGET } },
		{ } },
	      "ERROR"
	    }
    }
};

static struct arpt_table packet_filter = {
	.name		= "filter",
	.valid_hooks	= FILTER_VALID_HOOKS,
	.lock		= RW_LOCK_UNLOCKED,
	.private	= NULL,
	.me		= THIS_MODULE,
	.af		= NF_ARP,
};

/* The work comes in here from netfilter.c */
static unsigned int arpt_hook(unsigned int hook,
			      struct sk_buff **pskb,
			      const struct net_device *in,
			      const struct net_device *out,
			      int (*okfn)(struct sk_buff *))
{
	return arpt_do_table(pskb, hook, in, out, &packet_filter, NULL);
}

static struct nf_hook_ops arpt_ops[] = {
	{
		.hook		= arpt_hook,
		.owner		= THIS_MODULE,
		.pf		= NF_ARP,
		.hooknum	= NF_ARP_IN,
	},
	{
		.hook		= arpt_hook,
		.owner		= THIS_MODULE,
		.pf		= NF_ARP,
		.hooknum	= NF_ARP_OUT,
	},
	{
		.hook		= arpt_hook,
		.owner		= THIS_MODULE,
		.pf		= NF_ARP,
		.hooknum	= NF_ARP_FORWARD,
	},
};

static int __init arptable_filter_init(void)
{
	int ret, i;

	/* Register table */
	ret = arpt_register_table(&packet_filter, &initial_table.repl);
	if (ret < 0)
		return ret;

	for (i = 0; i < ARRAY_SIZE(arpt_ops); i++)
		if ((ret = nf_register_hook(&arpt_ops[i])) < 0)
			goto cleanup_hooks;
	return ret;

cleanup_hooks:
	while (--i >= 0)
		nf_unregister_hook(&arpt_ops[i]);

	arpt_unregister_table(&packet_filter);
	return ret;
}

static void __exit arptable_filter_fini(void)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(arpt_ops); i++)
		nf_unregister_hook(&arpt_ops[i]);

	arpt_unregister_table(&packet_filter);
}

module_init(arptable_filter_init);
module_exit(arptable_filter_fini);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Filtering ARP tables module.
	3	*
	4	* Copyright (C) 2002 David S. Miller (davem@redhat.com)
	5	*
	6	*/
	7
	8	#include <linux/module.h>
	9	#include <linux/netfilter_arp/arp_tables.h>
	10
	11	MODULE_LICENSE("GPL");
	12	MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
	13	MODULE_DESCRIPTION("arptables filter table");
	14
	15	#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) \| (1 << NF_ARP_OUT) \| \
	16	(1 << NF_ARP_FORWARD))
	17
	18	/* Standard entry. */
	19	struct arpt_standard
	20	{
	21	struct arpt_entry entry;
	22	struct arpt_standard_target target;
	23	};
	24
	25	struct arpt_error_target
	26	{
	27	struct arpt_entry_target target;
	28	char errorname[ARPT_FUNCTION_MAXNAMELEN];
	29	};
	30
	31	struct arpt_error
	32	{
	33	struct arpt_entry entry;
	34	struct arpt_error_target target;
	35	};
	36
	37	static struct
	38	{
	39	struct arpt_replace repl;
	40	struct arpt_standard entries[3];
	41	struct arpt_error term;
	42	} initial_table __initdata
	43	= { { "filter", FILTER_VALID_HOOKS, 4,
	44	sizeof(struct arpt_standard) * 3 + sizeof(struct arpt_error),
	45	{ [NF_ARP_IN] = 0,
	46	[NF_ARP_OUT] = sizeof(struct arpt_standard),
	47	[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), },
	48	{ [NF_ARP_IN] = 0,
	49	[NF_ARP_OUT] = sizeof(struct arpt_standard),
	50	[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard), },
	51	0, NULL, { } },
	52	{
	53	/* ARP_IN */
	54	{
	55	{
	56	{
	57	{ 0 }, { 0 }, { 0 }, { 0 },
	58	0, 0,
	59	{ { 0, }, { 0, } },
	60	{ { 0, }, { 0, } },
	61	0, 0,
	62	0, 0,
	63	0, 0,
	64	"", "", { 0 }, { 0 },
65	0, 0
66	},
67	sizeof(struct arpt_entry),
68	sizeof(struct arpt_standard),
69	0,
70	{ 0, 0 }, { } },
71	{ { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
72	-NF_ACCEPT - 1 }
73	},
74	/* ARP_OUT */
75	{
76	{
77	{
78	{ 0 }, { 0 }, { 0 }, { 0 },
79	0, 0,
80	{ { 0, }, { 0, } },
81	{ { 0, }, { 0, } },
82	0, 0,
83	0, 0,
84	0, 0,
85	"", "", { 0 }, { 0 },
86	0, 0
87	},
88	sizeof(struct arpt_entry),
89	sizeof(struct arpt_standard),
90	0,
91	{ 0, 0 }, { } },
92	{ { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
93	-NF_ACCEPT - 1 }
94	},
95	/* ARP_FORWARD */
96	{
97	{
98	{
99	{ 0 }, { 0 }, { 0 }, { 0 },
100	0, 0,
101	{ { 0, }, { 0, } },
102	{ { 0, }, { 0, } },
103	0, 0,
104	0, 0,
105	0, 0,
106	"", "", { 0 }, { 0 },
107	0, 0
108	},
109	sizeof(struct arpt_entry),
110	sizeof(struct arpt_standard),
111	0,
112	{ 0, 0 }, { } },
113	{ { { { ARPT_ALIGN(sizeof(struct arpt_standard_target)), "" } }, { } },
114	-NF_ACCEPT - 1 }
115	}
116	},
117	/* ERROR */
118	{
119	{
120	{
121	{ 0 }, { 0 }, { 0 }, { 0 },
122	0, 0,
123	{ { 0, }, { 0, } },
124	{ { 0, }, { 0, } },
125	0, 0,
126	0, 0,
127	0, 0,
128	"", "", { 0 }, { 0 },
129	0, 0
130	},
131	sizeof(struct arpt_entry),
132	sizeof(struct arpt_error),
133	0,
134	{ 0, 0 }, { } },
135	{ { { { ARPT_ALIGN(sizeof(struct arpt_error_target)), ARPT_ERROR_TARGET } },
136	{ } },
137	"ERROR"
138	}
139	}
140	};
141
142	static struct arpt_table packet_filter = {
143	.name = "filter",
144	.valid_hooks = FILTER_VALID_HOOKS,
145	.lock = RW_LOCK_UNLOCKED,
146	.private = NULL,
147	.me = THIS_MODULE,
2e4e6a17	148	.af = NF_ARP,
1da177e4 LT	149	};
	150
	151	/* The work comes in here from netfilter.c */
	152	static unsigned int arpt_hook(unsigned int hook,
	153	struct sk_buff **pskb,
	154	const struct net_device *in,
	155	const struct net_device *out,
	156	int (okfn)(struct sk_buff ))
	157	{
	158	return arpt_do_table(pskb, hook, in, out, &packet_filter, NULL);
	159	}
	160
	161	static struct nf_hook_ops arpt_ops[] = {
	162	{
	163	.hook = arpt_hook,
	164	.owner = THIS_MODULE,
	165	.pf = NF_ARP,
	166	.hooknum = NF_ARP_IN,
	167	},
	168	{
	169	.hook = arpt_hook,
	170	.owner = THIS_MODULE,
	171	.pf = NF_ARP,
	172	.hooknum = NF_ARP_OUT,
	173	},
	174	{
	175	.hook = arpt_hook,
	176	.owner = THIS_MODULE,
	177	.pf = NF_ARP,
	178	.hooknum = NF_ARP_FORWARD,
	179	},
	180	};
	181
65b4b4e8	182	static int __init arptable_filter_init(void)
1da177e4 LT	183	{
	184	int ret, i;
	185
	186	/* Register table */
	187	ret = arpt_register_table(&packet_filter, &initial_table.repl);
	188	if (ret < 0)
	189	return ret;
	190
	191	for (i = 0; i < ARRAY_SIZE(arpt_ops); i++)
	192	if ((ret = nf_register_hook(&arpt_ops[i])) < 0)
	193	goto cleanup_hooks;
	194	return ret;
	195
	196	cleanup_hooks:
	197	while (--i >= 0)
	198	nf_unregister_hook(&arpt_ops[i]);
	199
	200	arpt_unregister_table(&packet_filter);
	201	return ret;
	202	}
	203
65b4b4e8	204	static void __exit arptable_filter_fini(void)
1da177e4 LT	205	{
	206	unsigned int i;
	207
	208	for (i = 0; i < ARRAY_SIZE(arpt_ops); i++)
	209	nf_unregister_hook(&arpt_ops[i]);
	210
	211	arpt_unregister_table(&packet_filter);
	212	}
	213
65b4b4e8 AM	214	module_init(arptable_filter_init);
65b4b4e8 AM	215	module_exit(arptable_filter_fini);