[mirror_ubuntu-hirsute-kernel.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 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) < 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 struct ip6t_ip6 *ip,
	   void *matchinfo,
	   unsigned int matchinfosize,
	   unsigned int hook_mask)
{
	const struct ip6t_esp *espinfo = matchinfo;

	if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_esp))) {
		DEBUGP("ip6t_esp: matchsize %u != %u\n",
			 matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_esp)));
		return 0;
	}
	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,
	.checkentry	= &checkentry,
	.me		= THIS_MODULE,
};

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

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

module_init(init);
module_exit(cleanup);
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,
	47	const void *matchinfo,
	48	int offset,
	49	unsigned int protoff,
	50	int *hotdrop)
	51	{
e674d0f3	52	struct ip_esp_hdr _esp, *eh;
1da177e4	53	const struct ip6t_esp *espinfo = matchinfo;
1da177e4 LT	54	unsigned int ptr;
	55
	56	/* Make sure this isn't an evil packet */
	57	/DEBUGP("ipv6_esp entered \n");/
	58
e674d0f3	59	if (ipv6_find_hdr(skb, &ptr, NEXTHDR_ESP) < 0)
1da177e4 LT	60	return 0;
1da177e4 LT	61
e674d0f3 YK	62	eh = skb_header_pointer(skb, ptr, sizeof(_esp), &_esp);
e674d0f3 YK	63	if (eh == NULL) {
1da177e4 LT	64	*hotdrop = 1;
	65	return 0;
	66	}
	67
1da177e4 LT	68	DEBUGP("IPv6 ESP SPI %u %08X\n", ntohl(eh->spi), ntohl(eh->spi));
	69
	70	return (eh != NULL)
	71	&& spi_match(espinfo->spis[0], espinfo->spis[1],
	72	ntohl(eh->spi),
	73	!!(espinfo->invflags & IP6T_ESP_INV_SPI));
	74	}
	75
	76	/* Called when user tries to insert an entry of this type. */
	77	static int
	78	checkentry(const char *tablename,
	79	const struct ip6t_ip6 *ip,
	80	void *matchinfo,
	81	unsigned int matchinfosize,
	82	unsigned int hook_mask)
	83	{
	84	const struct ip6t_esp *espinfo = matchinfo;
	85
	86	if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_esp))) {
	87	DEBUGP("ip6t_esp: matchsize %u != %u\n",
	88	matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_esp)));
	89	return 0;
	90	}
	91	if (espinfo->invflags & ~IP6T_ESP_INV_MASK) {
	92	DEBUGP("ip6t_esp: unknown flags %X\n",
	93	espinfo->invflags);
	94	return 0;
	95	}
	96	return 1;
	97	}
	98
	99	static struct ip6t_match esp_match = {
	100	.name = "esp",
	101	.match = &match,
	102	.checkentry = &checkentry,
	103	.me = THIS_MODULE,
	104	};
	105
	106	static int __init init(void)
	107	{
	108	return ip6t_register_match(&esp_match);
	109	}
	110
	111	static void __exit cleanup(void)
	112	{
	113	ip6t_unregister_match(&esp_match);
	114	}
	115
	116	module_init(init);
	117	module_exit(cleanup);