[deliverable/linux.git] / net / ipv6 / netfilter / ip6t_esp.c

/* Kernel module to match ESP parameters. */
/* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
 *
 * 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/skbuff.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/types.h>
#include <net/checksum.h>
#include <net/ipv6.h>

#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter_ipv6/ip6t_esp.h>

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("IPv6 ESP match");
MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");

#if 0
#define DEBUGP printk
#else
#define DEBUGP(format, args...)
#endif

/* Returns 1 if the spi is matched by the range, 0 otherwise */
static inline int
spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, int invert)
{
	int r=0;
	DEBUGP("esp spi_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ',
	       min,spi,max);
	r=(spi >= min && spi <= max) ^ invert;
	DEBUGP(" result %s\n",r? "PASS\n" : "FAILED\n");
	return r;
}

static int
match(const struct sk_buff *skb,
      const struct net_device *in,
      const struct net_device *out,
      const struct xt_match *match,
      const void *matchinfo,
      int offset,
      unsigned int protoff,
      int *hotdrop)
{
	struct ip_esp_hdr _esp, *eh;
	const struct ip6t_esp *espinfo = matchinfo;
	unsigned int ptr;

	/* Make sure this isn't an evil packet */
	/*DEBUGP("ipv6_esp entered \n");*/

	if (ipv6_find_hdr(skb, &ptr, NEXTHDR_ESP, NULL) < 0)
		return 0;

	eh = skb_header_pointer(skb, ptr, sizeof(_esp), &_esp);
	if (eh == NULL) {
		*hotdrop = 1;
		return 0;
	}

	DEBUGP("IPv6 ESP SPI %u %08X\n", ntohl(eh->spi), ntohl(eh->spi));

	return (eh != NULL)
		&& spi_match(espinfo->spis[0], espinfo->spis[1],
			      ntohl(eh->spi),
			      !!(espinfo->invflags & IP6T_ESP_INV_SPI));
}

/* Called when user tries to insert an entry of this type. */
static int
checkentry(const char *tablename,
	   const void *ip,
	   const struct xt_match *match,
	   void *matchinfo,
	   unsigned int matchinfosize,
	   unsigned int hook_mask)
{
	const struct ip6t_esp *espinfo = matchinfo;

	if (espinfo->invflags & ~IP6T_ESP_INV_MASK) {
		DEBUGP("ip6t_esp: unknown flags %X\n",
			 espinfo->invflags);
		return 0;
	}
	return 1;
}

static struct ip6t_match esp_match = {
	.name		= "esp",
	.match		= match,
	.matchsize	= sizeof(struct ip6t_esp),
	.checkentry	= checkentry,
	.me		= THIS_MODULE,
};

static int __init ip6t_esp_init(void)
{
	return ip6t_register_match(&esp_match);
}

static void __exit ip6t_esp_fini(void)
{
	ip6t_unregister_match(&esp_match);
}

module_init(ip6t_esp_init);
module_exit(ip6t_esp_fini);
Commit	Line	Data
1da177e4 LT	1	/* Kernel module to match ESP parameters. */
	2	/* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9
	10	#include <linux/module.h>
	11	#include <linux/skbuff.h>
14c85021	12	#include <linux/ip.h>
1da177e4 LT	13	#include <linux/ipv6.h>
	14	#include <linux/types.h>
	15	#include <net/checksum.h>
	16	#include <net/ipv6.h>
	17
	18	#include <linux/netfilter_ipv6/ip6_tables.h>
	19	#include <linux/netfilter_ipv6/ip6t_esp.h>
	20
	21	MODULE_LICENSE("GPL");
	22	MODULE_DESCRIPTION("IPv6 ESP match");
	23	MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
	24
	25	#if 0
	26	#define DEBUGP printk
	27	#else
	28	#define DEBUGP(format, args...)
	29	#endif
	30
	31	/* Returns 1 if the spi is matched by the range, 0 otherwise */
	32	static inline int
	33	spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, int invert)
	34	{
	35	int r=0;
	36	DEBUGP("esp spi_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ',
	37	min,spi,max);
	38	r=(spi >= min && spi <= max) ^ invert;
	39	DEBUGP(" result %s\n",r? "PASS\n" : "FAILED\n");
	40	return r;
	41	}
	42
	43	static int
	44	match(const struct sk_buff *skb,
	45	const struct net_device *in,
	46	const struct net_device *out,
c4986734	47	const struct xt_match *match,
1da177e4 LT	48	const void *matchinfo,
	49	int offset,
	50	unsigned int protoff,
	51	int *hotdrop)
	52	{
e674d0f3	53	struct ip_esp_hdr _esp, *eh;
1da177e4	54	const struct ip6t_esp *espinfo = matchinfo;
1da177e4 LT	55	unsigned int ptr;
	56
	57	/* Make sure this isn't an evil packet */
	58	/DEBUGP("ipv6_esp entered \n");/
	59
b777e0ce	60	if (ipv6_find_hdr(skb, &ptr, NEXTHDR_ESP, NULL) < 0)
1da177e4 LT	61	return 0;
1da177e4 LT	62
e674d0f3 YK	63	eh = skb_header_pointer(skb, ptr, sizeof(_esp), &_esp);
e674d0f3 YK	64	if (eh == NULL) {
1da177e4 LT	65	*hotdrop = 1;
	66	return 0;
	67	}
	68
1da177e4 LT	69	DEBUGP("IPv6 ESP SPI %u %08X\n", ntohl(eh->spi), ntohl(eh->spi));
	70
	71	return (eh != NULL)
	72	&& spi_match(espinfo->spis[0], espinfo->spis[1],
	73	ntohl(eh->spi),
	74	!!(espinfo->invflags & IP6T_ESP_INV_SPI));
	75	}
	76
	77	/* Called when user tries to insert an entry of this type. */
	78	static int
	79	checkentry(const char *tablename,
2e4e6a17	80	const void *ip,
c4986734	81	const struct xt_match *match,
1da177e4 LT	82	void *matchinfo,
	83	unsigned int matchinfosize,
	84	unsigned int hook_mask)
	85	{
	86	const struct ip6t_esp *espinfo = matchinfo;
	87
1da177e4 LT	88	if (espinfo->invflags & ~IP6T_ESP_INV_MASK) {
	89	DEBUGP("ip6t_esp: unknown flags %X\n",
	90	espinfo->invflags);
	91	return 0;
	92	}
	93	return 1;
	94	}
	95
	96	static struct ip6t_match esp_match = {
	97	.name = "esp",
7f939713 PM	98	.match = match,
	99	.matchsize = sizeof(struct ip6t_esp),
	100	.checkentry = checkentry,
1da177e4 LT	101	.me = THIS_MODULE,
	102	};
	103
65b4b4e8	104	static int __init ip6t_esp_init(void)
1da177e4 LT	105	{
	106	return ip6t_register_match(&esp_match);
	107	}
	108
65b4b4e8	109	static void __exit ip6t_esp_fini(void)
1da177e4 LT	110	{
	111	ip6t_unregister_match(&esp_match);
	112	}
	113
65b4b4e8 AM	114	module_init(ip6t_esp_init);
65b4b4e8 AM	115	module_exit(ip6t_esp_fini);