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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 | */ | |
ff67e4e4 | 9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 LT |
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; |
ff67e4e4 | 32 | pr_debug("segsleft_match:%c 0x%x <= 0x%x <= 0x%x\n", |
0d53778e | 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 | ||
62fc8051 | 39 | static bool rt_mt6(const struct sk_buff *skb, struct xt_action_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) | |
b4ba2611 | 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) { | |
b4ba2611 | 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 | 94 | |
3666ed1c | 95 | ret = (rh != NULL) && |
f0daaa65 YK |
96 | (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1], |
97 | rh->segments_left, | |
3666ed1c | 98 | !!(rtinfo->invflags & IP6T_RT_INV_SGS))) && |
f0daaa65 YK |
99 | (!(rtinfo->flags & IP6T_RT_LEN) || |
100 | ((rtinfo->hdrlen == hdrlen) ^ | |
3666ed1c | 101 | !!(rtinfo->invflags & IP6T_RT_INV_LEN))) && |
f0daaa65 YK |
102 | (!(rtinfo->flags & IP6T_RT_TYP) || |
103 | ((rtinfo->rt_type == rh->type) ^ | |
104 | !!(rtinfo->invflags & IP6T_RT_INV_TYP))); | |
1da177e4 LT |
105 | |
106 | if (ret && (rtinfo->flags & IP6T_RT_RES)) { | |
3cf93c96 JE |
107 | const u_int32_t *rp; |
108 | u_int32_t _reserved; | |
e6df439b | 109 | rp = skb_header_pointer(skb, |
f0daaa65 YK |
110 | ptr + offsetof(struct rt0_hdr, |
111 | reserved), | |
112 | sizeof(_reserved), | |
113 | &_reserved); | |
1da177e4 | 114 | |
e6df439b | 115 | ret = (*rp == 0); |
1da177e4 LT |
116 | } |
117 | ||
0d53778e | 118 | pr_debug("#%d ", rtinfo->addrnr); |
f0daaa65 YK |
119 | if (!(rtinfo->flags & IP6T_RT_FST)) { |
120 | return ret; | |
1da177e4 | 121 | } else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) { |
0d53778e | 122 | pr_debug("Not strict "); |
f0daaa65 | 123 | if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { |
0d53778e | 124 | pr_debug("There isn't enough space\n"); |
1d93a9cb | 125 | return false; |
1da177e4 LT |
126 | } else { |
127 | unsigned int i = 0; | |
128 | ||
0d53778e | 129 | pr_debug("#%d ", rtinfo->addrnr); |
f0daaa65 YK |
130 | for (temp = 0; |
131 | temp < (unsigned int)((hdrlen - 8) / 16); | |
132 | temp++) { | |
1da177e4 LT |
133 | ap = skb_header_pointer(skb, |
134 | ptr | |
135 | + sizeof(struct rt0_hdr) | |
136 | + temp * sizeof(_addr), | |
137 | sizeof(_addr), | |
138 | &_addr); | |
139 | ||
140 | BUG_ON(ap == NULL); | |
141 | ||
142 | if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) { | |
0d53778e | 143 | pr_debug("i=%d temp=%d;\n", i, temp); |
1da177e4 LT |
144 | i++; |
145 | } | |
f0daaa65 YK |
146 | if (i == rtinfo->addrnr) |
147 | break; | |
1da177e4 | 148 | } |
0d53778e | 149 | pr_debug("i=%d #%d\n", i, rtinfo->addrnr); |
1da177e4 LT |
150 | if (i == rtinfo->addrnr) |
151 | return ret; | |
f0daaa65 | 152 | else |
1d93a9cb | 153 | return false; |
1da177e4 LT |
154 | } |
155 | } else { | |
0d53778e | 156 | pr_debug("Strict "); |
f0daaa65 | 157 | if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { |
0d53778e | 158 | pr_debug("There isn't enough space\n"); |
1d93a9cb | 159 | return false; |
1da177e4 | 160 | } else { |
0d53778e | 161 | pr_debug("#%d ", rtinfo->addrnr); |
f0daaa65 | 162 | for (temp = 0; temp < rtinfo->addrnr; temp++) { |
1da177e4 LT |
163 | ap = skb_header_pointer(skb, |
164 | ptr | |
165 | + sizeof(struct rt0_hdr) | |
166 | + temp * sizeof(_addr), | |
167 | sizeof(_addr), | |
168 | &_addr); | |
169 | BUG_ON(ap == NULL); | |
170 | ||
171 | if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp])) | |
172 | break; | |
173 | } | |
0d53778e | 174 | pr_debug("temp=%d #%d\n", temp, rtinfo->addrnr); |
7c4e36bc JE |
175 | if (temp == rtinfo->addrnr && |
176 | temp == (unsigned int)((hdrlen - 8) / 16)) | |
1da177e4 | 177 | return ret; |
f0daaa65 | 178 | else |
1d93a9cb | 179 | return false; |
1da177e4 LT |
180 | } |
181 | } | |
182 | ||
1d93a9cb | 183 | return false; |
1da177e4 LT |
184 | } |
185 | ||
b0f38452 | 186 | static int rt_mt6_check(const struct xt_mtchk_param *par) |
1da177e4 | 187 | { |
9b4fce7a | 188 | const struct ip6t_rt *rtinfo = par->matchinfo; |
f0daaa65 | 189 | |
f0daaa65 | 190 | if (rtinfo->invflags & ~IP6T_RT_INV_MASK) { |
ff67e4e4 | 191 | pr_debug("unknown flags %X\n", rtinfo->invflags); |
bd414ee6 | 192 | return -EINVAL; |
f0daaa65 YK |
193 | } |
194 | if ((rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST_MASK)) && | |
195 | (!(rtinfo->flags & IP6T_RT_TYP) || | |
196 | (rtinfo->rt_type != 0) || | |
197 | (rtinfo->invflags & IP6T_RT_INV_TYP))) { | |
0d53778e | 198 | pr_debug("`--rt-type 0' required before `--rt-0-*'"); |
bd414ee6 | 199 | return -EINVAL; |
f0daaa65 YK |
200 | } |
201 | ||
bd414ee6 | 202 | return 0; |
1da177e4 LT |
203 | } |
204 | ||
d3c5ee6d | 205 | static struct xt_match rt_mt6_reg __read_mostly = { |
1da177e4 | 206 | .name = "rt", |
ee999d8b | 207 | .family = NFPROTO_IPV6, |
d3c5ee6d | 208 | .match = rt_mt6, |
7f939713 | 209 | .matchsize = sizeof(struct ip6t_rt), |
d3c5ee6d | 210 | .checkentry = rt_mt6_check, |
1da177e4 LT |
211 | .me = THIS_MODULE, |
212 | }; | |
213 | ||
d3c5ee6d | 214 | static int __init rt_mt6_init(void) |
1da177e4 | 215 | { |
d3c5ee6d | 216 | return xt_register_match(&rt_mt6_reg); |
1da177e4 LT |
217 | } |
218 | ||
d3c5ee6d | 219 | static void __exit rt_mt6_exit(void) |
1da177e4 | 220 | { |
d3c5ee6d | 221 | xt_unregister_match(&rt_mt6_reg); |
1da177e4 LT |
222 | } |
223 | ||
d3c5ee6d JE |
224 | module_init(rt_mt6_init); |
225 | module_exit(rt_mt6_exit); |