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"); | |
24 | MODULE_DESCRIPTION("IPv6 RT match"); | |
25 | MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>"); | |
26 | ||
27 | #if 0 | |
28 | #define DEBUGP printk | |
29 | #else | |
30 | #define DEBUGP(format, args...) | |
31 | #endif | |
32 | ||
33 | /* Returns 1 if the id is matched by the range, 0 otherwise */ | |
1d93a9cb JE |
34 | static inline bool |
35 | segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, bool invert) | |
1da177e4 | 36 | { |
1d93a9cb | 37 | bool r; |
f0daaa65 YK |
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"); | |
42 | return r; | |
1da177e4 LT |
43 | } |
44 | ||
1d93a9cb | 45 | static bool |
1da177e4 LT |
46 | match(const struct sk_buff *skb, |
47 | const struct net_device *in, | |
48 | const struct net_device *out, | |
c4986734 | 49 | const struct xt_match *match, |
1da177e4 LT |
50 | const void *matchinfo, |
51 | int offset, | |
52 | unsigned int protoff, | |
cff533ac | 53 | bool *hotdrop) |
1da177e4 | 54 | { |
a47362a2 JE |
55 | struct ipv6_rt_hdr _route; |
56 | const struct ipv6_rt_hdr *rh; | |
f0daaa65 YK |
57 | const struct ip6t_rt *rtinfo = matchinfo; |
58 | unsigned int temp; | |
59 | unsigned int ptr; | |
60 | unsigned int hdrlen = 0; | |
1d93a9cb | 61 | bool ret = false; |
a47362a2 JE |
62 | struct in6_addr _addr; |
63 | const struct in6_addr *ap; | |
6d381634 | 64 | int err; |
1da177e4 | 65 | |
6d381634 PM |
66 | err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL); |
67 | if (err < 0) { | |
68 | if (err != -ENOENT) | |
cff533ac | 69 | *hotdrop = true; |
1d93a9cb | 70 | return false; |
6d381634 | 71 | } |
1da177e4 | 72 | |
f0daaa65 YK |
73 | rh = skb_header_pointer(skb, ptr, sizeof(_route), &_route); |
74 | if (rh == NULL) { | |
cff533ac | 75 | *hotdrop = true; |
1d93a9cb | 76 | return false; |
f0daaa65 YK |
77 | } |
78 | ||
79 | hdrlen = ipv6_optlen(rh); | |
80 | if (skb->len - ptr < hdrlen) { | |
81 | /* Pcket smaller than its length field */ | |
1d93a9cb | 82 | return false; |
f0daaa65 YK |
83 | } |
84 | ||
85 | DEBUGP("IPv6 RT LEN %u %u ", hdrlen, rh->hdrlen); | |
86 | DEBUGP("TYPE %04X ", rh->type); | |
87 | DEBUGP("SGS_LEFT %u %02X\n", rh->segments_left, rh->segments_left); | |
88 | ||
89 | DEBUGP("IPv6 RT segsleft %02X ", | |
7c4e36bc JE |
90 | segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1], |
91 | rh->segments_left, | |
92 | !!(rtinfo->invflags & IP6T_RT_INV_SGS))); | |
f0daaa65 YK |
93 | DEBUGP("type %02X %02X %02X ", |
94 | rtinfo->rt_type, rh->type, | |
95 | (!(rtinfo->flags & IP6T_RT_TYP) || | |
96 | ((rtinfo->rt_type == rh->type) ^ | |
97 | !!(rtinfo->invflags & IP6T_RT_INV_TYP)))); | |
98 | DEBUGP("len %02X %04X %02X ", | |
99 | rtinfo->hdrlen, hdrlen, | |
7c4e36bc | 100 | !(rtinfo->flags & IP6T_RT_LEN) || |
f0daaa65 | 101 | ((rtinfo->hdrlen == hdrlen) ^ |
7c4e36bc | 102 | !!(rtinfo->invflags & IP6T_RT_INV_LEN))); |
f0daaa65 | 103 | DEBUGP("res %02X %02X %02X ", |
7c4e36bc | 104 | rtinfo->flags & IP6T_RT_RES, |
a47362a2 | 105 | ((const struct rt0_hdr *)rh)->reserved, |
f0daaa65 | 106 | !((rtinfo->flags & IP6T_RT_RES) && |
a47362a2 | 107 | (((const struct rt0_hdr *)rh)->reserved))); |
f0daaa65 YK |
108 | |
109 | ret = (rh != NULL) | |
110 | && | |
111 | (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1], | |
112 | rh->segments_left, | |
113 | !!(rtinfo->invflags & IP6T_RT_INV_SGS))) | |
114 | && | |
115 | (!(rtinfo->flags & IP6T_RT_LEN) || | |
116 | ((rtinfo->hdrlen == hdrlen) ^ | |
117 | !!(rtinfo->invflags & IP6T_RT_INV_LEN))) | |
118 | && | |
119 | (!(rtinfo->flags & IP6T_RT_TYP) || | |
120 | ((rtinfo->rt_type == rh->type) ^ | |
121 | !!(rtinfo->invflags & IP6T_RT_INV_TYP))); | |
1da177e4 LT |
122 | |
123 | if (ret && (rtinfo->flags & IP6T_RT_RES)) { | |
e6df439b BH |
124 | u_int32_t *rp, _reserved; |
125 | rp = skb_header_pointer(skb, | |
f0daaa65 YK |
126 | ptr + offsetof(struct rt0_hdr, |
127 | reserved), | |
128 | sizeof(_reserved), | |
129 | &_reserved); | |
1da177e4 | 130 | |
e6df439b | 131 | ret = (*rp == 0); |
1da177e4 LT |
132 | } |
133 | ||
f0daaa65 YK |
134 | DEBUGP("#%d ", rtinfo->addrnr); |
135 | if (!(rtinfo->flags & IP6T_RT_FST)) { | |
136 | return ret; | |
1da177e4 LT |
137 | } else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) { |
138 | DEBUGP("Not strict "); | |
f0daaa65 | 139 | if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { |
1da177e4 | 140 | DEBUGP("There isn't enough space\n"); |
1d93a9cb | 141 | return false; |
1da177e4 LT |
142 | } else { |
143 | unsigned int i = 0; | |
144 | ||
f0daaa65 YK |
145 | DEBUGP("#%d ", rtinfo->addrnr); |
146 | for (temp = 0; | |
147 | temp < (unsigned int)((hdrlen - 8) / 16); | |
148 | temp++) { | |
1da177e4 LT |
149 | ap = skb_header_pointer(skb, |
150 | ptr | |
151 | + sizeof(struct rt0_hdr) | |
152 | + temp * sizeof(_addr), | |
153 | sizeof(_addr), | |
154 | &_addr); | |
155 | ||
156 | BUG_ON(ap == NULL); | |
157 | ||
158 | if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) { | |
f0daaa65 | 159 | DEBUGP("i=%d temp=%d;\n", i, temp); |
1da177e4 LT |
160 | i++; |
161 | } | |
f0daaa65 YK |
162 | if (i == rtinfo->addrnr) |
163 | break; | |
1da177e4 LT |
164 | } |
165 | DEBUGP("i=%d #%d\n", i, rtinfo->addrnr); | |
166 | if (i == rtinfo->addrnr) | |
167 | return ret; | |
f0daaa65 | 168 | else |
1d93a9cb | 169 | return false; |
1da177e4 LT |
170 | } |
171 | } else { | |
172 | DEBUGP("Strict "); | |
f0daaa65 | 173 | if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { |
1da177e4 | 174 | DEBUGP("There isn't enough space\n"); |
1d93a9cb | 175 | return false; |
1da177e4 | 176 | } else { |
f0daaa65 YK |
177 | DEBUGP("#%d ", rtinfo->addrnr); |
178 | for (temp = 0; temp < rtinfo->addrnr; temp++) { | |
1da177e4 LT |
179 | ap = skb_header_pointer(skb, |
180 | ptr | |
181 | + sizeof(struct rt0_hdr) | |
182 | + temp * sizeof(_addr), | |
183 | sizeof(_addr), | |
184 | &_addr); | |
185 | BUG_ON(ap == NULL); | |
186 | ||
187 | if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp])) | |
188 | break; | |
189 | } | |
190 | DEBUGP("temp=%d #%d\n", temp, rtinfo->addrnr); | |
7c4e36bc JE |
191 | if (temp == rtinfo->addrnr && |
192 | temp == (unsigned int)((hdrlen - 8) / 16)) | |
1da177e4 | 193 | return ret; |
f0daaa65 | 194 | else |
1d93a9cb | 195 | return false; |
1da177e4 LT |
196 | } |
197 | } | |
198 | ||
1d93a9cb | 199 | return false; |
1da177e4 LT |
200 | } |
201 | ||
202 | /* Called when user tries to insert an entry of this type. */ | |
ccb79bdc | 203 | static bool |
1da177e4 | 204 | checkentry(const char *tablename, |
f0daaa65 | 205 | const void *entry, |
c4986734 | 206 | const struct xt_match *match, |
f0daaa65 | 207 | void *matchinfo, |
f0daaa65 | 208 | unsigned int hook_mask) |
1da177e4 | 209 | { |
f0daaa65 YK |
210 | const struct ip6t_rt *rtinfo = matchinfo; |
211 | ||
f0daaa65 YK |
212 | if (rtinfo->invflags & ~IP6T_RT_INV_MASK) { |
213 | DEBUGP("ip6t_rt: unknown flags %X\n", rtinfo->invflags); | |
ccb79bdc | 214 | return false; |
f0daaa65 YK |
215 | } |
216 | if ((rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST_MASK)) && | |
217 | (!(rtinfo->flags & IP6T_RT_TYP) || | |
218 | (rtinfo->rt_type != 0) || | |
219 | (rtinfo->invflags & IP6T_RT_INV_TYP))) { | |
220 | DEBUGP("`--rt-type 0' required before `--rt-0-*'"); | |
ccb79bdc | 221 | return false; |
f0daaa65 YK |
222 | } |
223 | ||
ccb79bdc | 224 | return true; |
1da177e4 LT |
225 | } |
226 | ||
9f15c530 | 227 | static struct xt_match rt_match __read_mostly = { |
1da177e4 | 228 | .name = "rt", |
6709dbbb | 229 | .family = AF_INET6, |
7f939713 PM |
230 | .match = match, |
231 | .matchsize = sizeof(struct ip6t_rt), | |
232 | .checkentry = checkentry, | |
1da177e4 LT |
233 | .me = THIS_MODULE, |
234 | }; | |
235 | ||
65b4b4e8 | 236 | static int __init ip6t_rt_init(void) |
1da177e4 | 237 | { |
6709dbbb | 238 | return xt_register_match(&rt_match); |
1da177e4 LT |
239 | } |
240 | ||
65b4b4e8 | 241 | static void __exit ip6t_rt_fini(void) |
1da177e4 | 242 | { |
6709dbbb | 243 | xt_unregister_match(&rt_match); |
1da177e4 LT |
244 | } |
245 | ||
65b4b4e8 AM |
246 | module_init(ip6t_rt_init); |
247 | module_exit(ip6t_rt_fini); |