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1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * IPv4 Forwarding Information Base: policy rules. | |
7 | * | |
1da177e4 | 8 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
e1ef4bf2 | 9 | * Thomas Graf <tgraf@suug.ch> |
1da177e4 LT |
10 | * |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | * | |
16 | * Fixes: | |
17 | * Rani Assaf : local_rule cannot be deleted | |
18 | * Marc Boucher : routing by fwmark | |
19 | */ | |
20 | ||
1da177e4 LT |
21 | #include <linux/types.h> |
22 | #include <linux/kernel.h> | |
1da177e4 | 23 | #include <linux/netdevice.h> |
1da177e4 | 24 | #include <linux/netlink.h> |
e1ef4bf2 | 25 | #include <linux/inetdevice.h> |
1da177e4 | 26 | #include <linux/init.h> |
7b204afd RO |
27 | #include <linux/list.h> |
28 | #include <linux/rcupdate.h> | |
1da177e4 | 29 | #include <net/ip.h> |
1da177e4 LT |
30 | #include <net/route.h> |
31 | #include <net/tcp.h> | |
1da177e4 | 32 | #include <net/ip_fib.h> |
e1ef4bf2 | 33 | #include <net/fib_rules.h> |
1da177e4 | 34 | |
e1ef4bf2 | 35 | static struct fib_rules_ops fib4_rules_ops; |
1da177e4 | 36 | |
e1ef4bf2 | 37 | struct fib4_rule |
1da177e4 | 38 | { |
e1ef4bf2 TG |
39 | struct fib_rule common; |
40 | u8 dst_len; | |
41 | u8 src_len; | |
42 | u8 tos; | |
81f7bf6c AV |
43 | __be32 src; |
44 | __be32 srcmask; | |
45 | __be32 dst; | |
46 | __be32 dstmask; | |
1da177e4 | 47 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 | 48 | u32 tclassid; |
1da177e4 | 49 | #endif |
1da177e4 LT |
50 | }; |
51 | ||
e1ef4bf2 TG |
52 | static struct fib4_rule default_rule = { |
53 | .common = { | |
54 | .refcnt = ATOMIC_INIT(2), | |
55 | .pref = 0x7FFF, | |
56 | .table = RT_TABLE_DEFAULT, | |
57 | .action = FR_ACT_TO_TBL, | |
58 | }, | |
1da177e4 LT |
59 | }; |
60 | ||
e1ef4bf2 TG |
61 | static struct fib4_rule main_rule = { |
62 | .common = { | |
63 | .refcnt = ATOMIC_INIT(2), | |
64 | .pref = 0x7FFE, | |
65 | .table = RT_TABLE_MAIN, | |
66 | .action = FR_ACT_TO_TBL, | |
67 | }, | |
1da177e4 LT |
68 | }; |
69 | ||
e1ef4bf2 TG |
70 | static struct fib4_rule local_rule = { |
71 | .common = { | |
72 | .refcnt = ATOMIC_INIT(2), | |
73 | .table = RT_TABLE_LOCAL, | |
74 | .action = FR_ACT_TO_TBL, | |
75 | .flags = FIB_RULE_PERMANENT, | |
76 | }, | |
1da177e4 LT |
77 | }; |
78 | ||
e1ef4bf2 TG |
79 | static LIST_HEAD(fib4_rules); |
80 | ||
81 | #ifdef CONFIG_NET_CLS_ROUTE | |
82 | u32 fib_rules_tclass(struct fib_result *res) | |
83 | { | |
84 | return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0; | |
85 | } | |
86 | #endif | |
7b204afd | 87 | |
e1ef4bf2 TG |
88 | int fib_lookup(struct flowi *flp, struct fib_result *res) |
89 | { | |
90 | struct fib_lookup_arg arg = { | |
91 | .result = res, | |
92 | }; | |
93 | int err; | |
1da177e4 | 94 | |
e1ef4bf2 TG |
95 | err = fib_rules_lookup(&fib4_rules_ops, flp, 0, &arg); |
96 | res->r = arg.rule; | |
a5cdc030 | 97 | |
e1ef4bf2 TG |
98 | return err; |
99 | } | |
100 | ||
8ce11e6a AB |
101 | static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp, |
102 | int flags, struct fib_lookup_arg *arg) | |
1da177e4 | 103 | { |
e1ef4bf2 TG |
104 | int err = -EAGAIN; |
105 | struct fib_table *tbl; | |
106 | ||
107 | switch (rule->action) { | |
108 | case FR_ACT_TO_TBL: | |
109 | break; | |
110 | ||
111 | case FR_ACT_UNREACHABLE: | |
112 | err = -ENETUNREACH; | |
113 | goto errout; | |
114 | ||
115 | case FR_ACT_PROHIBIT: | |
116 | err = -EACCES; | |
117 | goto errout; | |
118 | ||
119 | case FR_ACT_BLACKHOLE: | |
120 | default: | |
121 | err = -EINVAL; | |
122 | goto errout; | |
1da177e4 | 123 | } |
e1ef4bf2 TG |
124 | |
125 | if ((tbl = fib_get_table(rule->table)) == NULL) | |
126 | goto errout; | |
127 | ||
128 | err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result); | |
129 | if (err > 0) | |
130 | err = -EAGAIN; | |
131 | errout: | |
1da177e4 LT |
132 | return err; |
133 | } | |
134 | ||
e1ef4bf2 TG |
135 | |
136 | void fib_select_default(const struct flowi *flp, struct fib_result *res) | |
137 | { | |
138 | if (res->r && res->r->action == FR_ACT_TO_TBL && | |
139 | FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) { | |
140 | struct fib_table *tb; | |
141 | if ((tb = fib_get_table(res->r->table)) != NULL) | |
142 | tb->tb_select_default(tb, flp, res); | |
143 | } | |
144 | } | |
145 | ||
146 | static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) | |
147 | { | |
148 | struct fib4_rule *r = (struct fib4_rule *) rule; | |
81f7bf6c AV |
149 | __be32 daddr = fl->fl4_dst; |
150 | __be32 saddr = fl->fl4_src; | |
e1ef4bf2 TG |
151 | |
152 | if (((saddr ^ r->src) & r->srcmask) || | |
153 | ((daddr ^ r->dst) & r->dstmask)) | |
154 | return 0; | |
155 | ||
156 | if (r->tos && (r->tos != fl->fl4_tos)) | |
157 | return 0; | |
158 | ||
e1ef4bf2 TG |
159 | return 1; |
160 | } | |
1da177e4 LT |
161 | |
162 | static struct fib_table *fib_empty_table(void) | |
163 | { | |
2dfe55b4 | 164 | u32 id; |
1da177e4 LT |
165 | |
166 | for (id = 1; id <= RT_TABLE_MAX; id++) | |
1af5a8c4 PM |
167 | if (fib_get_table(id) == NULL) |
168 | return fib_new_table(id); | |
1da177e4 LT |
169 | return NULL; |
170 | } | |
171 | ||
e1ef4bf2 | 172 | static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = { |
1f6c9557 | 173 | FRA_GENERIC_POLICY, |
e1ef4bf2 TG |
174 | [FRA_FLOW] = { .type = NLA_U32 }, |
175 | }; | |
7b204afd | 176 | |
e1ef4bf2 TG |
177 | static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, |
178 | struct nlmsghdr *nlh, struct fib_rule_hdr *frh, | |
179 | struct nlattr **tb) | |
1da177e4 | 180 | { |
e1ef4bf2 TG |
181 | int err = -EINVAL; |
182 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 183 | |
e1701c68 | 184 | if (frh->tos & ~IPTOS_TOS_MASK) |
e1ef4bf2 | 185 | goto errout; |
7b204afd | 186 | |
e1ef4bf2 TG |
187 | if (rule->table == RT_TABLE_UNSPEC) { |
188 | if (rule->action == FR_ACT_TO_TBL) { | |
189 | struct fib_table *table; | |
1da177e4 | 190 | |
e1ef4bf2 TG |
191 | table = fib_empty_table(); |
192 | if (table == NULL) { | |
193 | err = -ENOBUFS; | |
194 | goto errout; | |
195 | } | |
1da177e4 | 196 | |
e1ef4bf2 | 197 | rule->table = table->tb_id; |
1da177e4 LT |
198 | } |
199 | } | |
200 | ||
e1701c68 | 201 | if (frh->src_len) |
45d60b9e | 202 | rule4->src = nla_get_be32(tb[FRA_SRC]); |
7b204afd | 203 | |
e1701c68 | 204 | if (frh->dst_len) |
45d60b9e | 205 | rule4->dst = nla_get_be32(tb[FRA_DST]); |
7b204afd | 206 | |
1da177e4 | 207 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 TG |
208 | if (tb[FRA_FLOW]) |
209 | rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); | |
1da177e4 LT |
210 | #endif |
211 | ||
e1ef4bf2 TG |
212 | rule4->src_len = frh->src_len; |
213 | rule4->srcmask = inet_make_mask(rule4->src_len); | |
214 | rule4->dst_len = frh->dst_len; | |
215 | rule4->dstmask = inet_make_mask(rule4->dst_len); | |
216 | rule4->tos = frh->tos; | |
7b204afd | 217 | |
e1ef4bf2 TG |
218 | err = 0; |
219 | errout: | |
220 | return err; | |
1da177e4 LT |
221 | } |
222 | ||
e1ef4bf2 TG |
223 | static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, |
224 | struct nlattr **tb) | |
1da177e4 | 225 | { |
e1ef4bf2 | 226 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; |
1da177e4 | 227 | |
e1ef4bf2 TG |
228 | if (frh->src_len && (rule4->src_len != frh->src_len)) |
229 | return 0; | |
1da177e4 | 230 | |
e1ef4bf2 TG |
231 | if (frh->dst_len && (rule4->dst_len != frh->dst_len)) |
232 | return 0; | |
7b204afd | 233 | |
e1ef4bf2 TG |
234 | if (frh->tos && (rule4->tos != frh->tos)) |
235 | return 0; | |
7b204afd | 236 | |
e1ef4bf2 TG |
237 | #ifdef CONFIG_NET_CLS_ROUTE |
238 | if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) | |
239 | return 0; | |
240 | #endif | |
1da177e4 | 241 | |
e1701c68 | 242 | if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC]))) |
e1ef4bf2 | 243 | return 0; |
1da177e4 | 244 | |
e1701c68 | 245 | if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST]))) |
e1ef4bf2 | 246 | return 0; |
1da177e4 | 247 | |
e1ef4bf2 | 248 | return 1; |
1da177e4 LT |
249 | } |
250 | ||
e1ef4bf2 TG |
251 | static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, |
252 | struct nlmsghdr *nlh, struct fib_rule_hdr *frh) | |
253 | { | |
254 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 255 | |
e1ef4bf2 TG |
256 | frh->family = AF_INET; |
257 | frh->dst_len = rule4->dst_len; | |
258 | frh->src_len = rule4->src_len; | |
259 | frh->tos = rule4->tos; | |
1da177e4 | 260 | |
e1ef4bf2 | 261 | if (rule4->dst_len) |
45d60b9e | 262 | NLA_PUT_BE32(skb, FRA_DST, rule4->dst); |
e1ef4bf2 TG |
263 | |
264 | if (rule4->src_len) | |
45d60b9e | 265 | NLA_PUT_BE32(skb, FRA_SRC, rule4->src); |
e1ef4bf2 | 266 | |
1da177e4 | 267 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 TG |
268 | if (rule4->tclassid) |
269 | NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid); | |
1da177e4 | 270 | #endif |
e1ef4bf2 | 271 | return 0; |
1da177e4 | 272 | |
e1ef4bf2 TG |
273 | nla_put_failure: |
274 | return -ENOBUFS; | |
1da177e4 LT |
275 | } |
276 | ||
e1ef4bf2 | 277 | static u32 fib4_rule_default_pref(void) |
a5cdc030 | 278 | { |
e1ef4bf2 TG |
279 | struct list_head *pos; |
280 | struct fib_rule *rule; | |
281 | ||
282 | if (!list_empty(&fib4_rules)) { | |
283 | pos = fib4_rules.next; | |
284 | if (pos->next != &fib4_rules) { | |
285 | rule = list_entry(pos->next, struct fib_rule, list); | |
286 | if (rule->pref) | |
287 | return rule->pref - 1; | |
288 | } | |
a5cdc030 | 289 | } |
e1ef4bf2 TG |
290 | |
291 | return 0; | |
a5cdc030 PM |
292 | } |
293 | ||
339bf98f TG |
294 | static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) |
295 | { | |
296 | return nla_total_size(4) /* dst */ | |
297 | + nla_total_size(4) /* src */ | |
298 | + nla_total_size(4); /* flow */ | |
299 | } | |
300 | ||
e1ef4bf2 TG |
301 | static struct fib_rules_ops fib4_rules_ops = { |
302 | .family = AF_INET, | |
303 | .rule_size = sizeof(struct fib4_rule), | |
e1701c68 | 304 | .addr_size = sizeof(u32), |
e1ef4bf2 TG |
305 | .action = fib4_rule_action, |
306 | .match = fib4_rule_match, | |
307 | .configure = fib4_rule_configure, | |
308 | .compare = fib4_rule_compare, | |
309 | .fill = fib4_rule_fill, | |
310 | .default_pref = fib4_rule_default_pref, | |
339bf98f | 311 | .nlmsg_payload = fib4_rule_nlmsg_payload, |
e1ef4bf2 TG |
312 | .nlgroup = RTNLGRP_IPV4_RULE, |
313 | .policy = fib4_rule_policy, | |
314 | .rules_list = &fib4_rules, | |
315 | .owner = THIS_MODULE, | |
316 | }; | |
317 | ||
318 | void __init fib4_rules_init(void) | |
1da177e4 | 319 | { |
e1ef4bf2 TG |
320 | list_add_tail(&local_rule.common.list, &fib4_rules); |
321 | list_add_tail(&main_rule.common.list, &fib4_rules); | |
322 | list_add_tail(&default_rule.common.list, &fib4_rules); | |
1da177e4 | 323 | |
e1ef4bf2 | 324 | fib_rules_register(&fib4_rules_ops); |
1da177e4 | 325 | } |