blob: 03d1e8a43a48a7f48626ba82b12cf772b8048aa9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
Thomas Grafe1ef4bf2006-08-04 03:39:22 -07009 * Thomas Graf <tgraf@suug.ch>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/types.h>
22#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/netdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/netlink.h>
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070025#include <linux/inetdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/init.h>
Robert Olsson7b204af2006-03-20 17:18:53 -080027#include <linux/list.h>
28#include <linux/rcupdate.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <net/ip.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <net/route.h>
31#include <net/tcp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <net/ip_fib.h>
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070033#include <net/fib_rules.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070035static struct fib_rules_ops fib4_rules_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070037struct fib4_rule
Linus Torvalds1da177e2005-04-16 15:20:36 -070038{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070039 struct fib_rule common;
40 u8 dst_len;
41 u8 src_len;
42 u8 tos;
43 u32 src;
44 u32 srcmask;
45 u32 dst;
46 u32 dstmask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#ifdef CONFIG_IP_ROUTE_FWMARK
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070048 u32 fwmark;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#ifdef CONFIG_NET_CLS_ROUTE
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070051 u32 tclassid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070053};
54
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070055static struct fib4_rule default_rule = {
56 .common = {
57 .refcnt = ATOMIC_INIT(2),
58 .pref = 0x7FFF,
59 .table = RT_TABLE_DEFAULT,
60 .action = FR_ACT_TO_TBL,
61 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070062};
63
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070064static struct fib4_rule main_rule = {
65 .common = {
66 .refcnt = ATOMIC_INIT(2),
67 .pref = 0x7FFE,
68 .table = RT_TABLE_MAIN,
69 .action = FR_ACT_TO_TBL,
70 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070071};
72
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070073static struct fib4_rule local_rule = {
74 .common = {
75 .refcnt = ATOMIC_INIT(2),
76 .table = RT_TABLE_LOCAL,
77 .action = FR_ACT_TO_TBL,
78 .flags = FIB_RULE_PERMANENT,
79 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070080};
81
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070082static LIST_HEAD(fib4_rules);
Robert Olsson7b204af2006-03-20 17:18:53 -080083
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070084#ifdef CONFIG_NET_CLS_ROUTE
85u32 fib_rules_tclass(struct fib_result *res)
Linus Torvalds1da177e2005-04-16 15:20:36 -070086{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070087 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
88}
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070091int fib_lookup(struct flowi *flp, struct fib_result *res)
92{
93 struct fib_lookup_arg arg = {
94 .result = res,
95 };
96 int err;
97
98 err = fib_rules_lookup(&fib4_rules_ops, flp, 0, &arg);
99 res->r = arg.rule;
100
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 return err;
102}
103
Adrian Bunk8ce11e62006-08-07 21:50:48 -0700104static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
105 int flags, struct fib_lookup_arg *arg)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700106{
107 int err = -EAGAIN;
108 struct fib_table *tbl;
109
110 switch (rule->action) {
111 case FR_ACT_TO_TBL:
112 break;
113
114 case FR_ACT_UNREACHABLE:
115 err = -ENETUNREACH;
116 goto errout;
117
118 case FR_ACT_PROHIBIT:
119 err = -EACCES;
120 goto errout;
121
122 case FR_ACT_BLACKHOLE:
123 default:
124 err = -EINVAL;
125 goto errout;
126 }
127
128 if ((tbl = fib_get_table(rule->table)) == NULL)
129 goto errout;
130
131 err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);
132 if (err > 0)
133 err = -EAGAIN;
134errout:
135 return err;
136}
137
138
139void fib_select_default(const struct flowi *flp, struct fib_result *res)
140{
141 if (res->r && res->r->action == FR_ACT_TO_TBL &&
142 FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {
143 struct fib_table *tb;
144 if ((tb = fib_get_table(res->r->table)) != NULL)
145 tb->tb_select_default(tb, flp, res);
146 }
147}
148
149static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
150{
151 struct fib4_rule *r = (struct fib4_rule *) rule;
152 u32 daddr = fl->fl4_dst;
153 u32 saddr = fl->fl4_src;
154
155 if (((saddr ^ r->src) & r->srcmask) ||
156 ((daddr ^ r->dst) & r->dstmask))
157 return 0;
158
159 if (r->tos && (r->tos != fl->fl4_tos))
160 return 0;
161
162#ifdef CONFIG_IP_ROUTE_FWMARK
163 if (r->fwmark && (r->fwmark != fl->fl4_fwmark))
164 return 0;
165#endif
166
167 return 1;
168}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170static struct fib_table *fib_empty_table(void)
171{
172 int id;
173
174 for (id = 1; id <= RT_TABLE_MAX; id++)
175 if (fib_tables[id] == NULL)
176 return __fib_new_table(id);
177 return NULL;
178}
179
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700180static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = {
181 [FRA_IFNAME] = { .type = NLA_STRING },
182 [FRA_PRIORITY] = { .type = NLA_U32 },
183 [FRA_SRC] = { .type = NLA_U32 },
184 [FRA_DST] = { .type = NLA_U32 },
185 [FRA_FWMARK] = { .type = NLA_U32 },
186 [FRA_FLOW] = { .type = NLA_U32 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187};
188
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700189static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
190 struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
191 struct nlattr **tb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700193 int err = -EINVAL;
194 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700196 if (frh->src_len > 32 || frh->dst_len > 32 ||
197 (frh->tos & ~IPTOS_TOS_MASK))
198 goto errout;
199
200 if (rule->table == RT_TABLE_UNSPEC) {
201 if (rule->action == FR_ACT_TO_TBL) {
202 struct fib_table *table;
203
204 table = fib_empty_table();
205 if (table == NULL) {
206 err = -ENOBUFS;
207 goto errout;
208 }
209
210 rule->table = table->tb_id;
211 }
212 }
213
214 if (tb[FRA_SRC])
215 rule4->src = nla_get_u32(tb[FRA_SRC]);
216
217 if (tb[FRA_DST])
218 rule4->dst = nla_get_u32(tb[FRA_DST]);
219
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220#ifdef CONFIG_IP_ROUTE_FWMARK
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700221 if (tb[FRA_FWMARK])
222 rule4->fwmark = nla_get_u32(tb[FRA_FWMARK]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225#ifdef CONFIG_NET_CLS_ROUTE
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700226 if (tb[FRA_FLOW])
227 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700230 rule4->src_len = frh->src_len;
231 rule4->srcmask = inet_make_mask(rule4->src_len);
232 rule4->dst_len = frh->dst_len;
233 rule4->dstmask = inet_make_mask(rule4->dst_len);
234 rule4->tos = frh->tos;
235
236 err = 0;
237errout:
238 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239}
240
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700241static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
242 struct nlattr **tb)
Patrick McHardya5cdc032006-03-23 01:16:06 -0800243{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700244 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
Patrick McHardya5cdc032006-03-23 01:16:06 -0800245
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700246 if (frh->src_len && (rule4->src_len != frh->src_len))
247 return 0;
248
249 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
250 return 0;
251
252 if (frh->tos && (rule4->tos != frh->tos))
253 return 0;
254
255#ifdef CONFIG_IP_ROUTE_FWMARK
256 if (tb[FRA_FWMARK] && (rule4->fwmark != nla_get_u32(tb[FRA_FWMARK])))
257 return 0;
258#endif
259
260#ifdef CONFIG_NET_CLS_ROUTE
261 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
262 return 0;
263#endif
264
265 if (tb[FRA_SRC] && (rule4->src != nla_get_u32(tb[FRA_SRC])))
266 return 0;
267
268 if (tb[FRA_DST] && (rule4->dst != nla_get_u32(tb[FRA_DST])))
269 return 0;
270
271 return 1;
272}
273
274static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
275 struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
276{
277 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
278
279 frh->family = AF_INET;
280 frh->dst_len = rule4->dst_len;
281 frh->src_len = rule4->src_len;
282 frh->tos = rule4->tos;
283
284#ifdef CONFIG_IP_ROUTE_FWMARK
285 if (rule4->fwmark)
286 NLA_PUT_U32(skb, FRA_FWMARK, rule4->fwmark);
287#endif
288
289 if (rule4->dst_len)
290 NLA_PUT_U32(skb, FRA_DST, rule4->dst);
291
292 if (rule4->src_len)
293 NLA_PUT_U32(skb, FRA_SRC, rule4->src);
294
295#ifdef CONFIG_NET_CLS_ROUTE
296 if (rule4->tclassid)
297 NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
298#endif
299 return 0;
300
301nla_put_failure:
302 return -ENOBUFS;
303}
304
305int fib4_rules_dump(struct sk_buff *skb, struct netlink_callback *cb)
306{
307 return fib_rules_dump(skb, cb, AF_INET);
308}
309
310static u32 fib4_rule_default_pref(void)
311{
312 struct list_head *pos;
313 struct fib_rule *rule;
314
315 if (!list_empty(&fib4_rules)) {
316 pos = fib4_rules.next;
317 if (pos->next != &fib4_rules) {
318 rule = list_entry(pos->next, struct fib_rule, list);
319 if (rule->pref)
320 return rule->pref - 1;
321 }
Patrick McHardya5cdc032006-03-23 01:16:06 -0800322 }
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700323
324 return 0;
Patrick McHardya5cdc032006-03-23 01:16:06 -0800325}
326
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700327static struct fib_rules_ops fib4_rules_ops = {
328 .family = AF_INET,
329 .rule_size = sizeof(struct fib4_rule),
330 .action = fib4_rule_action,
331 .match = fib4_rule_match,
332 .configure = fib4_rule_configure,
333 .compare = fib4_rule_compare,
334 .fill = fib4_rule_fill,
335 .default_pref = fib4_rule_default_pref,
336 .nlgroup = RTNLGRP_IPV4_RULE,
337 .policy = fib4_rule_policy,
338 .rules_list = &fib4_rules,
339 .owner = THIS_MODULE,
340};
341
342void __init fib4_rules_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700344 list_add_tail(&local_rule.common.list, &fib4_rules);
345 list_add_tail(&main_rule.common.list, &fib4_rules);
346 list_add_tail(&default_rule.common.list, &fib4_rules);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700348 fib_rules_register(&fib4_rules_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349}
350
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700351void __exit fib4_rules_cleanup(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700353 fib_rules_unregister(&fib4_rules_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354}