2 * net/core/fib_rules.c Generic Routing Rules
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation, version 2.
8 * Authors: Thomas Graf <tgraf@suug.ch>
11 #include <linux/config.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/list.h>
15 #include <net/fib_rules.h>
17 static LIST_HEAD(rules_ops
);
18 static DEFINE_SPINLOCK(rules_mod_lock
);
20 static void notify_rule_change(int event
, struct fib_rule
*rule
,
21 struct fib_rules_ops
*ops
, struct nlmsghdr
*nlh
,
24 static struct fib_rules_ops
*lookup_rules_ops(int family
)
26 struct fib_rules_ops
*ops
;
29 list_for_each_entry_rcu(ops
, &rules_ops
, list
) {
30 if (ops
->family
== family
) {
31 if (!try_module_get(ops
->owner
))
42 static void rules_ops_put(struct fib_rules_ops
*ops
)
45 module_put(ops
->owner
);
48 int fib_rules_register(struct fib_rules_ops
*ops
)
51 struct fib_rules_ops
*o
;
53 if (ops
->rule_size
< sizeof(struct fib_rule
))
56 if (ops
->match
== NULL
|| ops
->configure
== NULL
||
57 ops
->compare
== NULL
|| ops
->fill
== NULL
||
61 spin_lock(&rules_mod_lock
);
62 list_for_each_entry(o
, &rules_ops
, list
)
63 if (ops
->family
== o
->family
)
66 list_add_tail_rcu(&ops
->list
, &rules_ops
);
69 spin_unlock(&rules_mod_lock
);
74 EXPORT_SYMBOL_GPL(fib_rules_register
);
76 static void cleanup_ops(struct fib_rules_ops
*ops
)
78 struct fib_rule
*rule
, *tmp
;
80 list_for_each_entry_safe(rule
, tmp
, ops
->rules_list
, list
) {
81 list_del_rcu(&rule
->list
);
86 int fib_rules_unregister(struct fib_rules_ops
*ops
)
89 struct fib_rules_ops
*o
;
91 spin_lock(&rules_mod_lock
);
92 list_for_each_entry(o
, &rules_ops
, list
) {
94 list_del_rcu(&o
->list
);
102 spin_unlock(&rules_mod_lock
);
109 EXPORT_SYMBOL_GPL(fib_rules_unregister
);
111 int fib_rules_lookup(struct fib_rules_ops
*ops
, struct flowi
*fl
,
112 int flags
, struct fib_lookup_arg
*arg
)
114 struct fib_rule
*rule
;
119 list_for_each_entry_rcu(rule
, ops
->rules_list
, list
) {
120 if (rule
->ifindex
&& (rule
->ifindex
!= fl
->iif
))
123 if (!ops
->match(rule
, fl
, flags
))
126 err
= ops
->action(rule
, fl
, flags
, arg
);
127 if (err
!= -EAGAIN
) {
141 EXPORT_SYMBOL_GPL(fib_rules_lookup
);
143 int fib_nl_newrule(struct sk_buff
*skb
, struct nlmsghdr
* nlh
, void *arg
)
145 struct fib_rule_hdr
*frh
= nlmsg_data(nlh
);
146 struct fib_rules_ops
*ops
= NULL
;
147 struct fib_rule
*rule
, *r
, *last
= NULL
;
148 struct nlattr
*tb
[FRA_MAX
+1];
151 if (nlh
->nlmsg_len
< nlmsg_msg_size(sizeof(*frh
)))
154 ops
= lookup_rules_ops(frh
->family
);
160 err
= nlmsg_parse(nlh
, sizeof(*frh
), tb
, FRA_MAX
, ops
->policy
);
164 rule
= kzalloc(ops
->rule_size
, GFP_KERNEL
);
170 if (tb
[FRA_PRIORITY
])
171 rule
->pref
= nla_get_u32(tb
[FRA_PRIORITY
]);
173 if (tb
[FRA_IFNAME
]) {
174 struct net_device
*dev
;
177 nla_strlcpy(rule
->ifname
, tb
[FRA_IFNAME
], IFNAMSIZ
);
178 dev
= __dev_get_by_name(rule
->ifname
);
180 rule
->ifindex
= dev
->ifindex
;
183 rule
->action
= frh
->action
;
184 rule
->flags
= frh
->flags
;
185 rule
->table
= frh_get_table(frh
, tb
);
187 if (!rule
->pref
&& ops
->default_pref
)
188 rule
->pref
= ops
->default_pref();
190 err
= ops
->configure(rule
, skb
, nlh
, frh
, tb
);
194 list_for_each_entry(r
, ops
->rules_list
, list
) {
195 if (r
->pref
> rule
->pref
)
203 list_add_rcu(&rule
->list
, &last
->list
);
205 list_add_rcu(&rule
->list
, ops
->rules_list
);
207 notify_rule_change(RTM_NEWRULE
, rule
, ops
, nlh
, NETLINK_CB(skb
).pid
);
218 int fib_nl_delrule(struct sk_buff
*skb
, struct nlmsghdr
* nlh
, void *arg
)
220 struct fib_rule_hdr
*frh
= nlmsg_data(nlh
);
221 struct fib_rules_ops
*ops
= NULL
;
222 struct fib_rule
*rule
;
223 struct nlattr
*tb
[FRA_MAX
+1];
226 if (nlh
->nlmsg_len
< nlmsg_msg_size(sizeof(*frh
)))
229 ops
= lookup_rules_ops(frh
->family
);
235 err
= nlmsg_parse(nlh
, sizeof(*frh
), tb
, FRA_MAX
, ops
->policy
);
239 list_for_each_entry(rule
, ops
->rules_list
, list
) {
240 if (frh
->action
&& (frh
->action
!= rule
->action
))
243 if (frh
->table
&& (frh_get_table(frh
, tb
) != rule
->table
))
246 if (tb
[FRA_PRIORITY
] &&
247 (rule
->pref
!= nla_get_u32(tb
[FRA_PRIORITY
])))
250 if (tb
[FRA_IFNAME
] &&
251 nla_strcmp(tb
[FRA_IFNAME
], rule
->ifname
))
254 if (!ops
->compare(rule
, frh
, tb
))
257 if (rule
->flags
& FIB_RULE_PERMANENT
) {
262 list_del_rcu(&rule
->list
);
264 notify_rule_change(RTM_DELRULE
, rule
, ops
, nlh
,
265 NETLINK_CB(skb
).pid
);
277 static int fib_nl_fill_rule(struct sk_buff
*skb
, struct fib_rule
*rule
,
278 u32 pid
, u32 seq
, int type
, int flags
,
279 struct fib_rules_ops
*ops
)
281 struct nlmsghdr
*nlh
;
282 struct fib_rule_hdr
*frh
;
284 nlh
= nlmsg_put(skb
, pid
, seq
, type
, sizeof(*frh
), flags
);
288 frh
= nlmsg_data(nlh
);
289 frh
->table
= rule
->table
;
290 NLA_PUT_U32(skb
, FRA_TABLE
, rule
->table
);
293 frh
->action
= rule
->action
;
294 frh
->flags
= rule
->flags
;
297 NLA_PUT_STRING(skb
, FRA_IFNAME
, rule
->ifname
);
300 NLA_PUT_U32(skb
, FRA_PRIORITY
, rule
->pref
);
302 if (ops
->fill(rule
, skb
, nlh
, frh
) < 0)
303 goto nla_put_failure
;
305 return nlmsg_end(skb
, nlh
);
308 return nlmsg_cancel(skb
, nlh
);
311 int fib_rules_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
, int family
)
314 struct fib_rule
*rule
;
315 struct fib_rules_ops
*ops
;
317 ops
= lookup_rules_ops(family
);
319 return -EAFNOSUPPORT
;
322 list_for_each_entry(rule
, ops
->rules_list
, list
) {
323 if (idx
< cb
->args
[0])
326 if (fib_nl_fill_rule(skb
, rule
, NETLINK_CB(cb
->skb
).pid
,
327 cb
->nlh
->nlmsg_seq
, RTM_NEWRULE
,
328 NLM_F_MULTI
, ops
) < 0)
340 EXPORT_SYMBOL_GPL(fib_rules_dump
);
342 static void notify_rule_change(int event
, struct fib_rule
*rule
,
343 struct fib_rules_ops
*ops
, struct nlmsghdr
*nlh
,
349 skb
= nlmsg_new(NLMSG_GOODSIZE
, GFP_KERNEL
);
353 err
= fib_nl_fill_rule(skb
, rule
, pid
, nlh
->nlmsg_seq
, event
, 0, ops
);
359 err
= rtnl_notify(skb
, pid
, ops
->nlgroup
, nlh
, GFP_KERNEL
);
362 rtnl_set_sk_err(ops
->nlgroup
, err
);
365 static void attach_rules(struct list_head
*rules
, struct net_device
*dev
)
367 struct fib_rule
*rule
;
369 list_for_each_entry(rule
, rules
, list
) {
370 if (rule
->ifindex
== -1 &&
371 strcmp(dev
->name
, rule
->ifname
) == 0)
372 rule
->ifindex
= dev
->ifindex
;
376 static void detach_rules(struct list_head
*rules
, struct net_device
*dev
)
378 struct fib_rule
*rule
;
380 list_for_each_entry(rule
, rules
, list
)
381 if (rule
->ifindex
== dev
->ifindex
)
386 static int fib_rules_event(struct notifier_block
*this, unsigned long event
,
389 struct net_device
*dev
= ptr
;
390 struct fib_rules_ops
*ops
;
396 case NETDEV_REGISTER
:
397 list_for_each_entry(ops
, &rules_ops
, list
)
398 attach_rules(ops
->rules_list
, dev
);
401 case NETDEV_UNREGISTER
:
402 list_for_each_entry(ops
, &rules_ops
, list
)
403 detach_rules(ops
->rules_list
, dev
);
412 static struct notifier_block fib_rules_notifier
= {
413 .notifier_call
= fib_rules_event
,
416 static int __init
fib_rules_init(void)
418 return register_netdevice_notifier(&fib_rules_notifier
);
421 subsys_initcall(fib_rules_init
);