Commit | Line | Data |
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1da177e4 LT |
1 | /* Kernel module to match ROUTING parameters. */ |
2 | ||
3 | /* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu> | |
4 | * | |
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. | |
8 | */ | |
9 | ||
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> | |
15 | #include <net/ipv6.h> | |
16 | ||
17 | #include <asm/byteorder.h> | |
18 | ||
6709dbbb | 19 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
20 | #include <linux/netfilter_ipv6/ip6_tables.h> |
21 | #include <linux/netfilter_ipv6/ip6t_rt.h> | |
22 | ||
23 | MODULE_LICENSE("GPL"); | |
2ae15b64 | 24 | MODULE_DESCRIPTION("Xtables: IPv6 Routing Header match"); |
1da177e4 LT |
25 | MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>"); |
26 | ||
1da177e4 | 27 | /* Returns 1 if the id is matched by the range, 0 otherwise */ |
1d93a9cb JE |
28 | static inline bool |
29 | segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, bool invert) | |
1da177e4 | 30 | { |
1d93a9cb | 31 | bool r; |
0d53778e PM |
32 | pr_debug("rt segsleft_match:%c 0x%x <= 0x%x <= 0x%x", |
33 | invert ? '!' : ' ', min, id, max); | |
f0daaa65 | 34 | r = (id >= min && id <= max) ^ invert; |
0d53778e | 35 | pr_debug(" result %s\n", r ? "PASS" : "FAILED"); |
f0daaa65 | 36 | return r; |
1da177e4 LT |
37 | } |
38 | ||
f7108a20 | 39 | static bool rt_mt6(const struct sk_buff *skb, const struct xt_match_param *par) |
1da177e4 | 40 | { |
a47362a2 JE |
41 | struct ipv6_rt_hdr _route; |
42 | const struct ipv6_rt_hdr *rh; | |
f7108a20 | 43 | const struct ip6t_rt *rtinfo = par->matchinfo; |
f0daaa65 YK |
44 | unsigned int temp; |
45 | unsigned int ptr; | |
46 | unsigned int hdrlen = 0; | |
1d93a9cb | 47 | bool ret = false; |
a47362a2 JE |
48 | struct in6_addr _addr; |
49 | const struct in6_addr *ap; | |
6d381634 | 50 | int err; |
1da177e4 | 51 | |
6d381634 PM |
52 | err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL); |
53 | if (err < 0) { | |
54 | if (err != -ENOENT) | |
f7108a20 | 55 | *par->hotdrop = true; |
1d93a9cb | 56 | return false; |
6d381634 | 57 | } |
1da177e4 | 58 | |
f0daaa65 YK |
59 | rh = skb_header_pointer(skb, ptr, sizeof(_route), &_route); |
60 | if (rh == NULL) { | |
f7108a20 | 61 | *par->hotdrop = true; |
1d93a9cb | 62 | return false; |
f0daaa65 YK |
63 | } |
64 | ||
65 | hdrlen = ipv6_optlen(rh); | |
66 | if (skb->len - ptr < hdrlen) { | |
67 | /* Pcket smaller than its length field */ | |
1d93a9cb | 68 | return false; |
f0daaa65 YK |
69 | } |
70 | ||
0d53778e PM |
71 | pr_debug("IPv6 RT LEN %u %u ", hdrlen, rh->hdrlen); |
72 | pr_debug("TYPE %04X ", rh->type); | |
73 | pr_debug("SGS_LEFT %u %02X\n", rh->segments_left, rh->segments_left); | |
74 | ||
75 | pr_debug("IPv6 RT segsleft %02X ", | |
76 | segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1], | |
77 | rh->segments_left, | |
78 | !!(rtinfo->invflags & IP6T_RT_INV_SGS))); | |
79 | pr_debug("type %02X %02X %02X ", | |
80 | rtinfo->rt_type, rh->type, | |
81 | (!(rtinfo->flags & IP6T_RT_TYP) || | |
82 | ((rtinfo->rt_type == rh->type) ^ | |
83 | !!(rtinfo->invflags & IP6T_RT_INV_TYP)))); | |
84 | pr_debug("len %02X %04X %02X ", | |
85 | rtinfo->hdrlen, hdrlen, | |
86 | !(rtinfo->flags & IP6T_RT_LEN) || | |
87 | ((rtinfo->hdrlen == hdrlen) ^ | |
88 | !!(rtinfo->invflags & IP6T_RT_INV_LEN))); | |
89 | pr_debug("res %02X %02X %02X ", | |
90 | rtinfo->flags & IP6T_RT_RES, | |
91 | ((const struct rt0_hdr *)rh)->reserved, | |
92 | !((rtinfo->flags & IP6T_RT_RES) && | |
93 | (((const struct rt0_hdr *)rh)->reserved))); | |
f0daaa65 YK |
94 | |
95 | ret = (rh != NULL) | |
96 | && | |
97 | (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1], | |
98 | rh->segments_left, | |
99 | !!(rtinfo->invflags & IP6T_RT_INV_SGS))) | |
100 | && | |
101 | (!(rtinfo->flags & IP6T_RT_LEN) || | |
102 | ((rtinfo->hdrlen == hdrlen) ^ | |
103 | !!(rtinfo->invflags & IP6T_RT_INV_LEN))) | |
104 | && | |
105 | (!(rtinfo->flags & IP6T_RT_TYP) || | |
106 | ((rtinfo->rt_type == rh->type) ^ | |
107 | !!(rtinfo->invflags & IP6T_RT_INV_TYP))); | |
1da177e4 LT |
108 | |
109 | if (ret && (rtinfo->flags & IP6T_RT_RES)) { | |
3cf93c96 JE |
110 | const u_int32_t *rp; |
111 | u_int32_t _reserved; | |
e6df439b | 112 | rp = skb_header_pointer(skb, |
f0daaa65 YK |
113 | ptr + offsetof(struct rt0_hdr, |
114 | reserved), | |
115 | sizeof(_reserved), | |
116 | &_reserved); | |
1da177e4 | 117 | |
e6df439b | 118 | ret = (*rp == 0); |
1da177e4 LT |
119 | } |
120 | ||
0d53778e | 121 | pr_debug("#%d ", rtinfo->addrnr); |
f0daaa65 YK |
122 | if (!(rtinfo->flags & IP6T_RT_FST)) { |
123 | return ret; | |
1da177e4 | 124 | } else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) { |
0d53778e | 125 | pr_debug("Not strict "); |
f0daaa65 | 126 | if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { |
0d53778e | 127 | pr_debug("There isn't enough space\n"); |
1d93a9cb | 128 | return false; |
1da177e4 LT |
129 | } else { |
130 | unsigned int i = 0; | |
131 | ||
0d53778e | 132 | pr_debug("#%d ", rtinfo->addrnr); |
f0daaa65 YK |
133 | for (temp = 0; |
134 | temp < (unsigned int)((hdrlen - 8) / 16); | |
135 | temp++) { | |
1da177e4 LT |
136 | ap = skb_header_pointer(skb, |
137 | ptr | |
138 | + sizeof(struct rt0_hdr) | |
139 | + temp * sizeof(_addr), | |
140 | sizeof(_addr), | |
141 | &_addr); | |
142 | ||
143 | BUG_ON(ap == NULL); | |
144 | ||
145 | if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) { | |
0d53778e | 146 | pr_debug("i=%d temp=%d;\n", i, temp); |
1da177e4 LT |
147 | i++; |
148 | } | |
f0daaa65 YK |
149 | if (i == rtinfo->addrnr) |
150 | break; | |
1da177e4 | 151 | } |
0d53778e | 152 | pr_debug("i=%d #%d\n", i, rtinfo->addrnr); |
1da177e4 LT |
153 | if (i == rtinfo->addrnr) |
154 | return ret; | |
f0daaa65 | 155 | else |
1d93a9cb | 156 | return false; |
1da177e4 LT |
157 | } |
158 | } else { | |
0d53778e | 159 | pr_debug("Strict "); |
f0daaa65 | 160 | if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { |
0d53778e | 161 | pr_debug("There isn't enough space\n"); |
1d93a9cb | 162 | return false; |
1da177e4 | 163 | } else { |
0d53778e | 164 | pr_debug("#%d ", rtinfo->addrnr); |
f0daaa65 | 165 | for (temp = 0; temp < rtinfo->addrnr; temp++) { |
1da177e4 LT |
166 | ap = skb_header_pointer(skb, |
167 | ptr | |
168 | + sizeof(struct rt0_hdr) | |
169 | + temp * sizeof(_addr), | |
170 | sizeof(_addr), | |
171 | &_addr); | |
172 | BUG_ON(ap == NULL); | |
173 | ||
174 | if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp])) | |
175 | break; | |
176 | } | |
0d53778e | 177 | pr_debug("temp=%d #%d\n", temp, rtinfo->addrnr); |
7c4e36bc JE |
178 | if (temp == rtinfo->addrnr && |
179 | temp == (unsigned int)((hdrlen - 8) / 16)) | |
1da177e4 | 180 | return ret; |
f0daaa65 | 181 | else |
1d93a9cb | 182 | return false; |
1da177e4 LT |
183 | } |
184 | } | |
185 | ||
1d93a9cb | 186 | return false; |
1da177e4 LT |
187 | } |
188 | ||
189 | /* Called when user tries to insert an entry of this type. */ | |
ccb79bdc | 190 | static bool |
d3c5ee6d JE |
191 | rt_mt6_check(const char *tablename, const void *entry, |
192 | const struct xt_match *match, void *matchinfo, | |
193 | unsigned int hook_mask) | |
1da177e4 | 194 | { |
f0daaa65 YK |
195 | const struct ip6t_rt *rtinfo = matchinfo; |
196 | ||
f0daaa65 | 197 | if (rtinfo->invflags & ~IP6T_RT_INV_MASK) { |
0d53778e | 198 | pr_debug("ip6t_rt: unknown flags %X\n", rtinfo->invflags); |
ccb79bdc | 199 | return false; |
f0daaa65 YK |
200 | } |
201 | if ((rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST_MASK)) && | |
202 | (!(rtinfo->flags & IP6T_RT_TYP) || | |
203 | (rtinfo->rt_type != 0) || | |
204 | (rtinfo->invflags & IP6T_RT_INV_TYP))) { | |
0d53778e | 205 | pr_debug("`--rt-type 0' required before `--rt-0-*'"); |
ccb79bdc | 206 | return false; |
f0daaa65 YK |
207 | } |
208 | ||
ccb79bdc | 209 | return true; |
1da177e4 LT |
210 | } |
211 | ||
d3c5ee6d | 212 | static struct xt_match rt_mt6_reg __read_mostly = { |
1da177e4 | 213 | .name = "rt", |
ee999d8b | 214 | .family = NFPROTO_IPV6, |
d3c5ee6d | 215 | .match = rt_mt6, |
7f939713 | 216 | .matchsize = sizeof(struct ip6t_rt), |
d3c5ee6d | 217 | .checkentry = rt_mt6_check, |
1da177e4 LT |
218 | .me = THIS_MODULE, |
219 | }; | |
220 | ||
d3c5ee6d | 221 | static int __init rt_mt6_init(void) |
1da177e4 | 222 | { |
d3c5ee6d | 223 | return xt_register_match(&rt_mt6_reg); |
1da177e4 LT |
224 | } |
225 | ||
d3c5ee6d | 226 | static void __exit rt_mt6_exit(void) |
1da177e4 | 227 | { |
d3c5ee6d | 228 | xt_unregister_match(&rt_mt6_reg); |
1da177e4 LT |
229 | } |
230 | ||
d3c5ee6d JE |
231 | module_init(rt_mt6_init); |
232 | module_exit(rt_mt6_exit); |