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_ipv6/ip6_tables.h>
20 #include <linux/netfilter_ipv6/ip6t_rt.h>
22 MODULE_LICENSE("GPL");
23 MODULE_DESCRIPTION("IPv6 RT match");
24 MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
29 #define DEBUGP(format, args...)
32 /* Returns 1 if the id is matched by the range, 0 otherwise */
34 segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, int invert)
37 DEBUGP("rt segsleft_match:%c 0x%x <= 0x%x <= 0x%x",
38 invert ? '!' : ' ', min, id, max);
39 r = (id >= min && id <= max) ^ invert;
40 DEBUGP(" result %s\n", r ? "PASS" : "FAILED");
45 match(const struct sk_buff *skb,
46 const struct net_device *in,
47 const struct net_device *out,
48 const struct xt_match *match,
49 const void *matchinfo,
54 struct ipv6_rt_hdr _route, *rh;
55 const struct ip6t_rt *rtinfo = matchinfo;
58 unsigned int hdrlen = 0;
60 struct in6_addr *ap, _addr;
63 err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL);
70 rh = skb_header_pointer(skb, ptr, sizeof(_route), &_route);
76 hdrlen = ipv6_optlen(rh);
77 if (skb->len - ptr < hdrlen) {
78 /* Pcket smaller than its length field */
82 DEBUGP("IPv6 RT LEN %u %u ", hdrlen, rh->hdrlen);
83 DEBUGP("TYPE %04X ", rh->type);
84 DEBUGP("SGS_LEFT %u %02X\n", rh->segments_left, rh->segments_left);
86 DEBUGP("IPv6 RT segsleft %02X ",
87 (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
89 !!(rtinfo->invflags & IP6T_RT_INV_SGS))));
90 DEBUGP("type %02X %02X %02X ",
91 rtinfo->rt_type, rh->type,
92 (!(rtinfo->flags & IP6T_RT_TYP) ||
93 ((rtinfo->rt_type == rh->type) ^
94 !!(rtinfo->invflags & IP6T_RT_INV_TYP))));
95 DEBUGP("len %02X %04X %02X ",
96 rtinfo->hdrlen, hdrlen,
97 (!(rtinfo->flags & IP6T_RT_LEN) ||
98 ((rtinfo->hdrlen == hdrlen) ^
99 !!(rtinfo->invflags & IP6T_RT_INV_LEN))));
100 DEBUGP("res %02X %02X %02X ",
101 (rtinfo->flags & IP6T_RT_RES),
102 ((struct rt0_hdr *)rh)->reserved,
103 !((rtinfo->flags & IP6T_RT_RES) &&
104 (((struct rt0_hdr *)rh)->reserved)));
108 (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
110 !!(rtinfo->invflags & IP6T_RT_INV_SGS)))
112 (!(rtinfo->flags & IP6T_RT_LEN) ||
113 ((rtinfo->hdrlen == hdrlen) ^
114 !!(rtinfo->invflags & IP6T_RT_INV_LEN)))
116 (!(rtinfo->flags & IP6T_RT_TYP) ||
117 ((rtinfo->rt_type == rh->type) ^
118 !!(rtinfo->invflags & IP6T_RT_INV_TYP)));
120 if (ret && (rtinfo->flags & IP6T_RT_RES)) {
121 u_int32_t *rp, _reserved;
122 rp = skb_header_pointer(skb,
123 ptr + offsetof(struct rt0_hdr,
131 DEBUGP("#%d ", rtinfo->addrnr);
132 if (!(rtinfo->flags & IP6T_RT_FST)) {
134 } else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) {
135 DEBUGP("Not strict ");
136 if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) {
137 DEBUGP("There isn't enough space\n");
142 DEBUGP("#%d ", rtinfo->addrnr);
144 temp < (unsigned int)((hdrlen - 8) / 16);
146 ap = skb_header_pointer(skb,
148 + sizeof(struct rt0_hdr)
149 + temp * sizeof(_addr),
155 if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) {
156 DEBUGP("i=%d temp=%d;\n", i, temp);
159 if (i == rtinfo->addrnr)
162 DEBUGP("i=%d #%d\n", i, rtinfo->addrnr);
163 if (i == rtinfo->addrnr)
170 if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) {
171 DEBUGP("There isn't enough space\n");
174 DEBUGP("#%d ", rtinfo->addrnr);
175 for (temp = 0; temp < rtinfo->addrnr; temp++) {
176 ap = skb_header_pointer(skb,
178 + sizeof(struct rt0_hdr)
179 + temp * sizeof(_addr),
184 if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp]))
187 DEBUGP("temp=%d #%d\n", temp, rtinfo->addrnr);
188 if ((temp == rtinfo->addrnr) &&
189 (temp == (unsigned int)((hdrlen - 8) / 16)))
199 /* Called when user tries to insert an entry of this type. */
201 checkentry(const char *tablename,
203 const struct xt_match *match,
205 unsigned int hook_mask)
207 const struct ip6t_rt *rtinfo = matchinfo;
209 if (rtinfo->invflags & ~IP6T_RT_INV_MASK) {
210 DEBUGP("ip6t_rt: unknown flags %X\n", rtinfo->invflags);
213 if ((rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST_MASK)) &&
214 (!(rtinfo->flags & IP6T_RT_TYP) ||
215 (rtinfo->rt_type != 0) ||
216 (rtinfo->invflags & IP6T_RT_INV_TYP))) {
217 DEBUGP("`--rt-type 0' required before `--rt-0-*'");
224 static struct ip6t_match rt_match = {
227 .matchsize = sizeof(struct ip6t_rt),
228 .checkentry = checkentry,
232 static int __init ip6t_rt_init(void)
234 return ip6t_register_match(&rt_match);
237 static void __exit ip6t_rt_fini(void)
239 ip6t_unregister_match(&rt_match);
242 module_init(ip6t_rt_init);
243 module_exit(ip6t_rt_fini);