1 /* Kernel module to match ESP parameters. */
2 /* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
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.
10 #include <linux/module.h>
11 #include <linux/skbuff.h>
13 #include <linux/ipv6.h>
14 #include <linux/types.h>
15 #include <net/checksum.h>
18 #include <linux/netfilter_ipv6/ip6_tables.h>
19 #include <linux/netfilter_ipv6/ip6t_esp.h>
21 MODULE_LICENSE("GPL");
22 MODULE_DESCRIPTION("IPv6 ESP match");
23 MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
28 #define DEBUGP(format, args...)
31 /* Returns 1 if the spi is matched by the range, 0 otherwise */
33 spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, int invert)
36 DEBUGP("esp spi_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ',
38 r=(spi >= min && spi <= max) ^ invert;
39 DEBUGP(" result %s\n",r? "PASS\n" : "FAILED\n");
44 match(const struct sk_buff *skb,
45 const struct net_device *in,
46 const struct net_device *out,
47 const void *matchinfo,
52 struct ip_esp_hdr _esp, *eh;
53 const struct ip6t_esp *espinfo = matchinfo;
56 /* Make sure this isn't an evil packet */
57 /*DEBUGP("ipv6_esp entered \n");*/
59 if (ipv6_find_hdr(skb, &ptr, NEXTHDR_ESP, NULL) < 0)
62 eh = skb_header_pointer(skb, ptr, sizeof(_esp), &_esp);
68 DEBUGP("IPv6 ESP SPI %u %08X\n", ntohl(eh->spi), ntohl(eh->spi));
71 && spi_match(espinfo->spis[0], espinfo->spis[1],
73 !!(espinfo->invflags & IP6T_ESP_INV_SPI));
76 /* Called when user tries to insert an entry of this type. */
78 checkentry(const char *tablename,
81 unsigned int matchinfosize,
82 unsigned int hook_mask)
84 const struct ip6t_esp *espinfo = matchinfo;
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)));
91 if (espinfo->invflags & ~IP6T_ESP_INV_MASK) {
92 DEBUGP("ip6t_esp: unknown flags %X\n",
99 static struct ip6t_match esp_match = {
102 .checkentry = &checkentry,
106 static int __init init(void)
108 return ip6t_register_match(&esp_match);
111 static void __exit cleanup(void)
113 ip6t_unregister_match(&esp_match);
117 module_exit(cleanup);