1 /* Kernel module to match ROUTING parameters. */
3 /* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/skbuff.h>
12 #include <linux/ipv6.h>
13 #include <linux/types.h>
14 #include <net/checksum.h>
17 #include <asm/byteorder.h>
19 #include <linux/netfilter/x_tables.h>
20 #include <linux/netfilter_ipv6/ip6_tables.h>
21 #include <linux/netfilter_ipv6/ip6t_rt.h>
23 MODULE_LICENSE("GPL");
24 MODULE_DESCRIPTION("IPv6 RT match");
25 MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
30 #define DEBUGP(format, args...)
33 /* Returns 1 if the id is matched by the range, 0 otherwise */
35 segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, int invert)
38 DEBUGP("rt segsleft_match:%c 0x%x <= 0x%x <= 0x%x",
39 invert ? '!' : ' ', min, id, max);
40 r = (id >= min && id <= max) ^ invert;
41 DEBUGP(" result %s\n", r ? "PASS" : "FAILED");
46 match(const struct sk_buff *skb,
47 const struct net_device *in,
48 const struct net_device *out,
49 const struct xt_match *match,
50 const void *matchinfo,
55 struct ipv6_rt_hdr _route, *rh;
56 const struct ip6t_rt *rtinfo = matchinfo;
59 unsigned int hdrlen = 0;
61 struct in6_addr *ap, _addr;
64 err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL);
71 rh = skb_header_pointer(skb, ptr, sizeof(_route), &_route);
77 hdrlen = ipv6_optlen(rh);
78 if (skb->len - ptr < hdrlen) {
79 /* Pcket smaller than its length field */
83 DEBUGP("IPv6 RT LEN %u %u ", hdrlen, rh->hdrlen);
84 DEBUGP("TYPE %04X ", rh->type);
85 DEBUGP("SGS_LEFT %u %02X\n", rh->segments_left, rh->segments_left);
87 DEBUGP("IPv6 RT segsleft %02X ",
88 (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
90 !!(rtinfo->invflags & IP6T_RT_INV_SGS))));
91 DEBUGP("type %02X %02X %02X ",
92 rtinfo->rt_type, rh->type,
93 (!(rtinfo->flags & IP6T_RT_TYP) ||
94 ((rtinfo->rt_type == rh->type) ^
95 !!(rtinfo->invflags & IP6T_RT_INV_TYP))));
96 DEBUGP("len %02X %04X %02X ",
97 rtinfo->hdrlen, hdrlen,
98 (!(rtinfo->flags & IP6T_RT_LEN) ||
99 ((rtinfo->hdrlen == hdrlen) ^
100 !!(rtinfo->invflags & IP6T_RT_INV_LEN))));
101 DEBUGP("res %02X %02X %02X ",
102 (rtinfo->flags & IP6T_RT_RES),
103 ((struct rt0_hdr *)rh)->reserved,
104 !((rtinfo->flags & IP6T_RT_RES) &&
105 (((struct rt0_hdr *)rh)->reserved)));
109 (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
111 !!(rtinfo->invflags & IP6T_RT_INV_SGS)))
113 (!(rtinfo->flags & IP6T_RT_LEN) ||
114 ((rtinfo->hdrlen == hdrlen) ^
115 !!(rtinfo->invflags & IP6T_RT_INV_LEN)))
117 (!(rtinfo->flags & IP6T_RT_TYP) ||
118 ((rtinfo->rt_type == rh->type) ^
119 !!(rtinfo->invflags & IP6T_RT_INV_TYP)));
121 if (ret && (rtinfo->flags & IP6T_RT_RES)) {
122 u_int32_t *rp, _reserved;
123 rp = skb_header_pointer(skb,
124 ptr + offsetof(struct rt0_hdr,
132 DEBUGP("#%d ", rtinfo->addrnr);
133 if (!(rtinfo->flags & IP6T_RT_FST)) {
135 } else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) {
136 DEBUGP("Not strict ");
137 if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) {
138 DEBUGP("There isn't enough space\n");
143 DEBUGP("#%d ", rtinfo->addrnr);
145 temp < (unsigned int)((hdrlen - 8) / 16);
147 ap = skb_header_pointer(skb,
149 + sizeof(struct rt0_hdr)
150 + temp * sizeof(_addr),
156 if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) {
157 DEBUGP("i=%d temp=%d;\n", i, temp);
160 if (i == rtinfo->addrnr)
163 DEBUGP("i=%d #%d\n", i, rtinfo->addrnr);
164 if (i == rtinfo->addrnr)
171 if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) {
172 DEBUGP("There isn't enough space\n");
175 DEBUGP("#%d ", rtinfo->addrnr);
176 for (temp = 0; temp < rtinfo->addrnr; temp++) {
177 ap = skb_header_pointer(skb,
179 + sizeof(struct rt0_hdr)
180 + temp * sizeof(_addr),
185 if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp]))
188 DEBUGP("temp=%d #%d\n", temp, rtinfo->addrnr);
189 if ((temp == rtinfo->addrnr) &&
190 (temp == (unsigned int)((hdrlen - 8) / 16)))
200 /* Called when user tries to insert an entry of this type. */
202 checkentry(const char *tablename,
204 const struct xt_match *match,
206 unsigned int hook_mask)
208 const struct ip6t_rt *rtinfo = matchinfo;
210 if (rtinfo->invflags & ~IP6T_RT_INV_MASK) {
211 DEBUGP("ip6t_rt: unknown flags %X\n", rtinfo->invflags);
214 if ((rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST_MASK)) &&
215 (!(rtinfo->flags & IP6T_RT_TYP) ||
216 (rtinfo->rt_type != 0) ||
217 (rtinfo->invflags & IP6T_RT_INV_TYP))) {
218 DEBUGP("`--rt-type 0' required before `--rt-0-*'");
225 static struct xt_match rt_match = {
229 .matchsize = sizeof(struct ip6t_rt),
230 .checkentry = checkentry,
234 static int __init ip6t_rt_init(void)
236 return xt_register_match(&rt_match);
239 static void __exit ip6t_rt_fini(void)
241 xt_unregister_match(&rt_match);
244 module_init(ip6t_rt_init);
245 module_exit(ip6t_rt_fini);