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.
6 * IPv4 Forwarding Information Base: policy rules.
8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
9 * Thomas Graf <tgraf@suug.ch>
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.
17 * Rani Assaf : local_rule cannot be deleted
18 * Marc Boucher : routing by fwmark
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/netdevice.h>
24 #include <linux/netlink.h>
25 #include <linux/inetdevice.h>
26 #include <linux/init.h>
27 #include <linux/list.h>
28 #include <linux/rcupdate.h>
30 #include <net/route.h>
32 #include <net/ip_fib.h>
33 #include <net/fib_rules.h>
35 static struct fib_rules_ops fib4_rules_ops;
39 struct fib_rule common;
47 #ifdef CONFIG_IP_ROUTE_FWMARK
50 #ifdef CONFIG_NET_CLS_ROUTE
55 static struct fib4_rule default_rule = {
57 .refcnt = ATOMIC_INIT(2),
59 .table = RT_TABLE_DEFAULT,
60 .action = FR_ACT_TO_TBL,
64 static struct fib4_rule main_rule = {
66 .refcnt = ATOMIC_INIT(2),
68 .table = RT_TABLE_MAIN,
69 .action = FR_ACT_TO_TBL,
73 static struct fib4_rule local_rule = {
75 .refcnt = ATOMIC_INIT(2),
76 .table = RT_TABLE_LOCAL,
77 .action = FR_ACT_TO_TBL,
78 .flags = FIB_RULE_PERMANENT,
82 static LIST_HEAD(fib4_rules);
84 #ifdef CONFIG_NET_CLS_ROUTE
85 u32 fib_rules_tclass(struct fib_result *res)
87 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
91 int fib_lookup(struct flowi *flp, struct fib_result *res)
93 struct fib_lookup_arg arg = {
98 err = fib_rules_lookup(&fib4_rules_ops, flp, 0, &arg);
104 static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
105 int flags, struct fib_lookup_arg *arg)
108 struct fib_table *tbl;
110 switch (rule->action) {
114 case FR_ACT_UNREACHABLE:
118 case FR_ACT_PROHIBIT:
122 case FR_ACT_BLACKHOLE:
128 if ((tbl = fib_get_table(rule->table)) == NULL)
131 err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);
139 void fib_select_default(const struct flowi *flp, struct fib_result *res)
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);
149 static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
151 struct fib4_rule *r = (struct fib4_rule *) rule;
152 u32 daddr = fl->fl4_dst;
153 u32 saddr = fl->fl4_src;
155 if (((saddr ^ r->src) & r->srcmask) ||
156 ((daddr ^ r->dst) & r->dstmask))
159 if (r->tos && (r->tos != fl->fl4_tos))
162 #ifdef CONFIG_IP_ROUTE_FWMARK
163 if (r->fwmark && (r->fwmark != fl->fl4_fwmark))
170 static struct fib_table *fib_empty_table(void)
174 for (id = 1; id <= RT_TABLE_MAX; id++)
175 if (fib_get_table(id) == NULL)
176 return fib_new_table(id);
180 static 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 },
187 [FRA_TABLE] = { .type = NLA_U32 },
190 static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
191 struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
195 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
197 if (frh->src_len > 32 || frh->dst_len > 32 ||
198 (frh->tos & ~IPTOS_TOS_MASK))
201 if (rule->table == RT_TABLE_UNSPEC) {
202 if (rule->action == FR_ACT_TO_TBL) {
203 struct fib_table *table;
205 table = fib_empty_table();
211 rule->table = table->tb_id;
216 rule4->src = nla_get_u32(tb[FRA_SRC]);
219 rule4->dst = nla_get_u32(tb[FRA_DST]);
221 #ifdef CONFIG_IP_ROUTE_FWMARK
223 rule4->fwmark = nla_get_u32(tb[FRA_FWMARK]);
226 #ifdef CONFIG_NET_CLS_ROUTE
228 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
231 rule4->src_len = frh->src_len;
232 rule4->srcmask = inet_make_mask(rule4->src_len);
233 rule4->dst_len = frh->dst_len;
234 rule4->dstmask = inet_make_mask(rule4->dst_len);
235 rule4->tos = frh->tos;
242 static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
245 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
247 if (frh->src_len && (rule4->src_len != frh->src_len))
250 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
253 if (frh->tos && (rule4->tos != frh->tos))
256 #ifdef CONFIG_IP_ROUTE_FWMARK
257 if (tb[FRA_FWMARK] && (rule4->fwmark != nla_get_u32(tb[FRA_FWMARK])))
261 #ifdef CONFIG_NET_CLS_ROUTE
262 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
266 if (tb[FRA_SRC] && (rule4->src != nla_get_u32(tb[FRA_SRC])))
269 if (tb[FRA_DST] && (rule4->dst != nla_get_u32(tb[FRA_DST])))
275 static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
276 struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
278 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
280 frh->family = AF_INET;
281 frh->dst_len = rule4->dst_len;
282 frh->src_len = rule4->src_len;
283 frh->tos = rule4->tos;
285 #ifdef CONFIG_IP_ROUTE_FWMARK
287 NLA_PUT_U32(skb, FRA_FWMARK, rule4->fwmark);
291 NLA_PUT_U32(skb, FRA_DST, rule4->dst);
294 NLA_PUT_U32(skb, FRA_SRC, rule4->src);
296 #ifdef CONFIG_NET_CLS_ROUTE
298 NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
306 int fib4_rules_dump(struct sk_buff *skb, struct netlink_callback *cb)
308 return fib_rules_dump(skb, cb, AF_INET);
311 static u32 fib4_rule_default_pref(void)
313 struct list_head *pos;
314 struct fib_rule *rule;
316 if (!list_empty(&fib4_rules)) {
317 pos = fib4_rules.next;
318 if (pos->next != &fib4_rules) {
319 rule = list_entry(pos->next, struct fib_rule, list);
321 return rule->pref - 1;
328 static struct fib_rules_ops fib4_rules_ops = {
330 .rule_size = sizeof(struct fib4_rule),
331 .action = fib4_rule_action,
332 .match = fib4_rule_match,
333 .configure = fib4_rule_configure,
334 .compare = fib4_rule_compare,
335 .fill = fib4_rule_fill,
336 .default_pref = fib4_rule_default_pref,
337 .nlgroup = RTNLGRP_IPV4_RULE,
338 .policy = fib4_rule_policy,
339 .rules_list = &fib4_rules,
340 .owner = THIS_MODULE,
343 void __init fib4_rules_init(void)
345 list_add_tail(&local_rule.common.list, &fib4_rules);
346 list_add_tail(&main_rule.common.list, &fib4_rules);
347 list_add_tail(&default_rule.common.list, &fib4_rules);
349 fib_rules_register(&fib4_rules_ops);