Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* Kernel module to match ROUTING parameters. */ |
3 | ||
4 | /* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu> | |
1da177e4 | 5 | */ |
ff67e4e4 | 6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 LT |
7 | #include <linux/module.h> |
8 | #include <linux/skbuff.h> | |
9 | #include <linux/ipv6.h> | |
10 | #include <linux/types.h> | |
11 | #include <net/checksum.h> | |
12 | #include <net/ipv6.h> | |
13 | ||
14 | #include <asm/byteorder.h> | |
15 | ||
6709dbbb | 16 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
17 | #include <linux/netfilter_ipv6/ip6_tables.h> |
18 | #include <linux/netfilter_ipv6/ip6t_rt.h> | |
19 | ||
20 | MODULE_LICENSE("GPL"); | |
2ae15b64 | 21 | MODULE_DESCRIPTION("Xtables: IPv6 Routing Header match"); |
1da177e4 LT |
22 | MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>"); |
23 | ||
1da177e4 | 24 | /* Returns 1 if the id is matched by the range, 0 otherwise */ |
1d93a9cb JE |
25 | static inline bool |
26 | segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, bool invert) | |
1da177e4 | 27 | { |
a482c5e0 | 28 | return (id >= min && id <= max) ^ invert; |
1da177e4 LT |
29 | } |
30 | ||
62fc8051 | 31 | static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par) |
1da177e4 | 32 | { |
a47362a2 JE |
33 | struct ipv6_rt_hdr _route; |
34 | const struct ipv6_rt_hdr *rh; | |
f7108a20 | 35 | const struct ip6t_rt *rtinfo = par->matchinfo; |
f0daaa65 | 36 | unsigned int temp; |
84018f55 | 37 | unsigned int ptr = 0; |
f0daaa65 | 38 | unsigned int hdrlen = 0; |
1d93a9cb | 39 | bool ret = false; |
a47362a2 JE |
40 | struct in6_addr _addr; |
41 | const struct in6_addr *ap; | |
6d381634 | 42 | int err; |
1da177e4 | 43 | |
84018f55 | 44 | err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL, NULL); |
6d381634 PM |
45 | if (err < 0) { |
46 | if (err != -ENOENT) | |
b4ba2611 | 47 | par->hotdrop = true; |
1d93a9cb | 48 | return false; |
6d381634 | 49 | } |
1da177e4 | 50 | |
f0daaa65 YK |
51 | rh = skb_header_pointer(skb, ptr, sizeof(_route), &_route); |
52 | if (rh == NULL) { | |
b4ba2611 | 53 | par->hotdrop = true; |
1d93a9cb | 54 | return false; |
f0daaa65 YK |
55 | } |
56 | ||
57 | hdrlen = ipv6_optlen(rh); | |
58 | if (skb->len - ptr < hdrlen) { | |
59 | /* Pcket smaller than its length field */ | |
1d93a9cb | 60 | return false; |
f0daaa65 YK |
61 | } |
62 | ||
42f36eba | 63 | ret = (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1], |
f0daaa65 | 64 | rh->segments_left, |
3666ed1c | 65 | !!(rtinfo->invflags & IP6T_RT_INV_SGS))) && |
f0daaa65 YK |
66 | (!(rtinfo->flags & IP6T_RT_LEN) || |
67 | ((rtinfo->hdrlen == hdrlen) ^ | |
3666ed1c | 68 | !!(rtinfo->invflags & IP6T_RT_INV_LEN))) && |
f0daaa65 YK |
69 | (!(rtinfo->flags & IP6T_RT_TYP) || |
70 | ((rtinfo->rt_type == rh->type) ^ | |
71 | !!(rtinfo->invflags & IP6T_RT_INV_TYP))); | |
1da177e4 LT |
72 | |
73 | if (ret && (rtinfo->flags & IP6T_RT_RES)) { | |
3cf93c96 JE |
74 | const u_int32_t *rp; |
75 | u_int32_t _reserved; | |
e6df439b | 76 | rp = skb_header_pointer(skb, |
f0daaa65 YK |
77 | ptr + offsetof(struct rt0_hdr, |
78 | reserved), | |
79 | sizeof(_reserved), | |
80 | &_reserved); | |
a482c5e0 XL |
81 | if (!rp) { |
82 | par->hotdrop = true; | |
83 | return false; | |
84 | } | |
1da177e4 | 85 | |
e6df439b | 86 | ret = (*rp == 0); |
1da177e4 LT |
87 | } |
88 | ||
f0daaa65 YK |
89 | if (!(rtinfo->flags & IP6T_RT_FST)) { |
90 | return ret; | |
1da177e4 | 91 | } else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) { |
f0daaa65 | 92 | if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { |
1d93a9cb | 93 | return false; |
1da177e4 LT |
94 | } else { |
95 | unsigned int i = 0; | |
96 | ||
f0daaa65 YK |
97 | for (temp = 0; |
98 | temp < (unsigned int)((hdrlen - 8) / 16); | |
99 | temp++) { | |
1da177e4 LT |
100 | ap = skb_header_pointer(skb, |
101 | ptr | |
102 | + sizeof(struct rt0_hdr) | |
103 | + temp * sizeof(_addr), | |
104 | sizeof(_addr), | |
105 | &_addr); | |
106 | ||
70c0eb1c FW |
107 | if (ap == NULL) { |
108 | par->hotdrop = true; | |
109 | return false; | |
110 | } | |
1da177e4 | 111 | |
a482c5e0 | 112 | if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) |
1da177e4 | 113 | i++; |
f0daaa65 YK |
114 | if (i == rtinfo->addrnr) |
115 | break; | |
1da177e4 | 116 | } |
1da177e4 LT |
117 | if (i == rtinfo->addrnr) |
118 | return ret; | |
f0daaa65 | 119 | else |
1d93a9cb | 120 | return false; |
1da177e4 LT |
121 | } |
122 | } else { | |
f0daaa65 | 123 | if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { |
1d93a9cb | 124 | return false; |
1da177e4 | 125 | } else { |
f0daaa65 | 126 | for (temp = 0; temp < rtinfo->addrnr; temp++) { |
1da177e4 LT |
127 | ap = skb_header_pointer(skb, |
128 | ptr | |
129 | + sizeof(struct rt0_hdr) | |
130 | + temp * sizeof(_addr), | |
131 | sizeof(_addr), | |
132 | &_addr); | |
70c0eb1c FW |
133 | if (ap == NULL) { |
134 | par->hotdrop = true; | |
135 | return false; | |
136 | } | |
1da177e4 LT |
137 | |
138 | if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp])) | |
139 | break; | |
140 | } | |
7c4e36bc JE |
141 | if (temp == rtinfo->addrnr && |
142 | temp == (unsigned int)((hdrlen - 8) / 16)) | |
1da177e4 | 143 | return ret; |
f0daaa65 | 144 | else |
1d93a9cb | 145 | return false; |
1da177e4 LT |
146 | } |
147 | } | |
148 | ||
1d93a9cb | 149 | return false; |
1da177e4 LT |
150 | } |
151 | ||
b0f38452 | 152 | static int rt_mt6_check(const struct xt_mtchk_param *par) |
1da177e4 | 153 | { |
9b4fce7a | 154 | const struct ip6t_rt *rtinfo = par->matchinfo; |
f0daaa65 | 155 | |
f0daaa65 | 156 | if (rtinfo->invflags & ~IP6T_RT_INV_MASK) { |
ff67e4e4 | 157 | pr_debug("unknown flags %X\n", rtinfo->invflags); |
bd414ee6 | 158 | return -EINVAL; |
f0daaa65 YK |
159 | } |
160 | if ((rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST_MASK)) && | |
161 | (!(rtinfo->flags & IP6T_RT_TYP) || | |
162 | (rtinfo->rt_type != 0) || | |
163 | (rtinfo->invflags & IP6T_RT_INV_TYP))) { | |
0d53778e | 164 | pr_debug("`--rt-type 0' required before `--rt-0-*'"); |
bd414ee6 | 165 | return -EINVAL; |
f0daaa65 YK |
166 | } |
167 | ||
bd414ee6 | 168 | return 0; |
1da177e4 LT |
169 | } |
170 | ||
d3c5ee6d | 171 | static struct xt_match rt_mt6_reg __read_mostly = { |
1da177e4 | 172 | .name = "rt", |
ee999d8b | 173 | .family = NFPROTO_IPV6, |
d3c5ee6d | 174 | .match = rt_mt6, |
7f939713 | 175 | .matchsize = sizeof(struct ip6t_rt), |
d3c5ee6d | 176 | .checkentry = rt_mt6_check, |
1da177e4 LT |
177 | .me = THIS_MODULE, |
178 | }; | |
179 | ||
d3c5ee6d | 180 | static int __init rt_mt6_init(void) |
1da177e4 | 181 | { |
d3c5ee6d | 182 | return xt_register_match(&rt_mt6_reg); |
1da177e4 LT |
183 | } |
184 | ||
d3c5ee6d | 185 | static void __exit rt_mt6_exit(void) |
1da177e4 | 186 | { |
d3c5ee6d | 187 | xt_unregister_match(&rt_mt6_reg); |
1da177e4 LT |
188 | } |
189 | ||
d3c5ee6d JE |
190 | module_init(rt_mt6_init); |
191 | module_exit(rt_mt6_exit); |