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/types.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/list.h>
15 #include <net/net_namespace.h>
17 #include <net/fib_rules.h>
19 int fib_default_rule_add(struct fib_rules_ops
*ops
,
20 u32 pref
, u32 table
, u32 flags
)
24 r
= kzalloc(ops
->rule_size
, GFP_KERNEL
);
28 atomic_set(&r
->refcnt
, 1);
29 r
->action
= FR_ACT_TO_TBL
;
33 r
->fr_net
= hold_net(ops
->fro_net
);
35 /* The lock is not required here, the list in unreacheable
36 * at the moment this function is called */
37 list_add_tail(&r
->list
, &ops
->rules_list
);
40 EXPORT_SYMBOL(fib_default_rule_add
);
42 static void notify_rule_change(int event
, struct fib_rule
*rule
,
43 struct fib_rules_ops
*ops
, struct nlmsghdr
*nlh
,
46 static struct fib_rules_ops
*lookup_rules_ops(struct net
*net
, int family
)
48 struct fib_rules_ops
*ops
;
51 list_for_each_entry_rcu(ops
, &net
->rules_ops
, list
) {
52 if (ops
->family
== family
) {
53 if (!try_module_get(ops
->owner
))
64 static void rules_ops_put(struct fib_rules_ops
*ops
)
67 module_put(ops
->owner
);
70 static void flush_route_cache(struct fib_rules_ops
*ops
)
73 ops
->flush_cache(ops
);
76 static int __fib_rules_register(struct fib_rules_ops
*ops
)
79 struct fib_rules_ops
*o
;
84 if (ops
->rule_size
< sizeof(struct fib_rule
))
87 if (ops
->match
== NULL
|| ops
->configure
== NULL
||
88 ops
->compare
== NULL
|| ops
->fill
== NULL
||
92 spin_lock(&net
->rules_mod_lock
);
93 list_for_each_entry(o
, &net
->rules_ops
, list
)
94 if (ops
->family
== o
->family
)
98 list_add_tail_rcu(&ops
->list
, &net
->rules_ops
);
101 spin_unlock(&net
->rules_mod_lock
);
106 struct fib_rules_ops
*
107 fib_rules_register(struct fib_rules_ops
*tmpl
, struct net
*net
)
109 struct fib_rules_ops
*ops
;
112 ops
= kmemdup(tmpl
, sizeof (*ops
), GFP_KERNEL
);
114 return ERR_PTR(-ENOMEM
);
116 INIT_LIST_HEAD(&ops
->rules_list
);
119 err
= __fib_rules_register(ops
);
128 EXPORT_SYMBOL_GPL(fib_rules_register
);
130 void fib_rules_cleanup_ops(struct fib_rules_ops
*ops
)
132 struct fib_rule
*rule
, *tmp
;
134 list_for_each_entry_safe(rule
, tmp
, &ops
->rules_list
, list
) {
135 list_del_rcu(&rule
->list
);
139 EXPORT_SYMBOL_GPL(fib_rules_cleanup_ops
);
141 static void fib_rules_put_rcu(struct rcu_head
*head
)
143 struct fib_rules_ops
*ops
= container_of(head
, struct fib_rules_ops
, rcu
);
144 struct net
*net
= ops
->fro_net
;
150 void fib_rules_unregister(struct fib_rules_ops
*ops
)
152 struct net
*net
= ops
->fro_net
;
154 spin_lock(&net
->rules_mod_lock
);
155 list_del_rcu(&ops
->list
);
156 fib_rules_cleanup_ops(ops
);
157 spin_unlock(&net
->rules_mod_lock
);
159 call_rcu(&ops
->rcu
, fib_rules_put_rcu
);
162 EXPORT_SYMBOL_GPL(fib_rules_unregister
);
164 static int fib_rule_match(struct fib_rule
*rule
, struct fib_rules_ops
*ops
,
165 struct flowi
*fl
, int flags
)
169 if (rule
->iifindex
&& (rule
->iifindex
!= fl
->iif
))
172 if (rule
->oifindex
&& (rule
->oifindex
!= fl
->oif
))
175 if ((rule
->mark
^ fl
->mark
) & rule
->mark_mask
)
178 ret
= ops
->match(rule
, fl
, flags
);
180 return (rule
->flags
& FIB_RULE_INVERT
) ? !ret
: ret
;
183 int fib_rules_lookup(struct fib_rules_ops
*ops
, struct flowi
*fl
,
184 int flags
, struct fib_lookup_arg
*arg
)
186 struct fib_rule
*rule
;
191 list_for_each_entry_rcu(rule
, &ops
->rules_list
, list
) {
193 if (!fib_rule_match(rule
, ops
, fl
, flags
))
196 if (rule
->action
== FR_ACT_GOTO
) {
197 struct fib_rule
*target
;
199 target
= rcu_dereference(rule
->ctarget
);
200 if (target
== NULL
) {
206 } else if (rule
->action
== FR_ACT_NOP
)
209 err
= ops
->action(rule
, fl
, flags
, arg
);
211 if (err
!= -EAGAIN
) {
225 EXPORT_SYMBOL_GPL(fib_rules_lookup
);
227 static int validate_rulemsg(struct fib_rule_hdr
*frh
, struct nlattr
**tb
,
228 struct fib_rules_ops
*ops
)
233 if (tb
[FRA_SRC
] == NULL
||
234 frh
->src_len
> (ops
->addr_size
* 8) ||
235 nla_len(tb
[FRA_SRC
]) != ops
->addr_size
)
239 if (tb
[FRA_DST
] == NULL
||
240 frh
->dst_len
> (ops
->addr_size
* 8) ||
241 nla_len(tb
[FRA_DST
]) != ops
->addr_size
)
249 static int fib_nl_newrule(struct sk_buff
*skb
, struct nlmsghdr
* nlh
, void *arg
)
251 struct net
*net
= sock_net(skb
->sk
);
252 struct fib_rule_hdr
*frh
= nlmsg_data(nlh
);
253 struct fib_rules_ops
*ops
= NULL
;
254 struct fib_rule
*rule
, *r
, *last
= NULL
;
255 struct nlattr
*tb
[FRA_MAX
+1];
256 int err
= -EINVAL
, unresolved
= 0;
258 if (nlh
->nlmsg_len
< nlmsg_msg_size(sizeof(*frh
)))
261 ops
= lookup_rules_ops(net
, frh
->family
);
267 err
= nlmsg_parse(nlh
, sizeof(*frh
), tb
, FRA_MAX
, ops
->policy
);
271 err
= validate_rulemsg(frh
, tb
, ops
);
275 rule
= kzalloc(ops
->rule_size
, GFP_KERNEL
);
280 rule
->fr_net
= hold_net(net
);
282 if (tb
[FRA_PRIORITY
])
283 rule
->pref
= nla_get_u32(tb
[FRA_PRIORITY
]);
285 if (tb
[FRA_IIFNAME
]) {
286 struct net_device
*dev
;
289 nla_strlcpy(rule
->iifname
, tb
[FRA_IIFNAME
], IFNAMSIZ
);
290 dev
= __dev_get_by_name(net
, rule
->iifname
);
292 rule
->iifindex
= dev
->ifindex
;
295 if (tb
[FRA_OIFNAME
]) {
296 struct net_device
*dev
;
299 nla_strlcpy(rule
->oifname
, tb
[FRA_OIFNAME
], IFNAMSIZ
);
300 dev
= __dev_get_by_name(net
, rule
->oifname
);
302 rule
->oifindex
= dev
->ifindex
;
305 if (tb
[FRA_FWMARK
]) {
306 rule
->mark
= nla_get_u32(tb
[FRA_FWMARK
]);
308 /* compatibility: if the mark value is non-zero all bits
309 * are compared unless a mask is explicitly specified.
311 rule
->mark_mask
= 0xFFFFFFFF;
315 rule
->mark_mask
= nla_get_u32(tb
[FRA_FWMASK
]);
317 rule
->action
= frh
->action
;
318 rule
->flags
= frh
->flags
;
319 rule
->table
= frh_get_table(frh
, tb
);
321 if (!tb
[FRA_PRIORITY
] && ops
->default_pref
)
322 rule
->pref
= ops
->default_pref(ops
);
326 if (rule
->action
!= FR_ACT_GOTO
)
329 rule
->target
= nla_get_u32(tb
[FRA_GOTO
]);
330 /* Backward jumps are prohibited to avoid endless loops */
331 if (rule
->target
<= rule
->pref
)
334 list_for_each_entry(r
, &ops
->rules_list
, list
) {
335 if (r
->pref
== rule
->target
) {
341 if (rule
->ctarget
== NULL
)
343 } else if (rule
->action
== FR_ACT_GOTO
)
346 err
= ops
->configure(rule
, skb
, frh
, tb
);
350 list_for_each_entry(r
, &ops
->rules_list
, list
) {
351 if (r
->pref
> rule
->pref
)
358 if (ops
->unresolved_rules
) {
360 * There are unresolved goto rules in the list, check if
361 * any of them are pointing to this new rule.
363 list_for_each_entry(r
, &ops
->rules_list
, list
) {
364 if (r
->action
== FR_ACT_GOTO
&&
365 r
->target
== rule
->pref
) {
366 BUG_ON(r
->ctarget
!= NULL
);
367 rcu_assign_pointer(r
->ctarget
, rule
);
368 if (--ops
->unresolved_rules
== 0)
374 if (rule
->action
== FR_ACT_GOTO
)
375 ops
->nr_goto_rules
++;
378 ops
->unresolved_rules
++;
381 list_add_rcu(&rule
->list
, &last
->list
);
383 list_add_rcu(&rule
->list
, &ops
->rules_list
);
385 notify_rule_change(RTM_NEWRULE
, rule
, ops
, nlh
, NETLINK_CB(skb
).pid
);
386 flush_route_cache(ops
);
391 release_net(rule
->fr_net
);
398 static int fib_nl_delrule(struct sk_buff
*skb
, struct nlmsghdr
* nlh
, void *arg
)
400 struct net
*net
= sock_net(skb
->sk
);
401 struct fib_rule_hdr
*frh
= nlmsg_data(nlh
);
402 struct fib_rules_ops
*ops
= NULL
;
403 struct fib_rule
*rule
, *tmp
;
404 struct nlattr
*tb
[FRA_MAX
+1];
407 if (nlh
->nlmsg_len
< nlmsg_msg_size(sizeof(*frh
)))
410 ops
= lookup_rules_ops(net
, frh
->family
);
416 err
= nlmsg_parse(nlh
, sizeof(*frh
), tb
, FRA_MAX
, ops
->policy
);
420 err
= validate_rulemsg(frh
, tb
, ops
);
424 list_for_each_entry(rule
, &ops
->rules_list
, list
) {
425 if (frh
->action
&& (frh
->action
!= rule
->action
))
428 if (frh
->table
&& (frh_get_table(frh
, tb
) != rule
->table
))
431 if (tb
[FRA_PRIORITY
] &&
432 (rule
->pref
!= nla_get_u32(tb
[FRA_PRIORITY
])))
435 if (tb
[FRA_IIFNAME
] &&
436 nla_strcmp(tb
[FRA_IIFNAME
], rule
->iifname
))
439 if (tb
[FRA_OIFNAME
] &&
440 nla_strcmp(tb
[FRA_OIFNAME
], rule
->oifname
))
443 if (tb
[FRA_FWMARK
] &&
444 (rule
->mark
!= nla_get_u32(tb
[FRA_FWMARK
])))
447 if (tb
[FRA_FWMASK
] &&
448 (rule
->mark_mask
!= nla_get_u32(tb
[FRA_FWMASK
])))
451 if (!ops
->compare(rule
, frh
, tb
))
454 if (rule
->flags
& FIB_RULE_PERMANENT
) {
459 list_del_rcu(&rule
->list
);
461 if (rule
->action
== FR_ACT_GOTO
)
462 ops
->nr_goto_rules
--;
465 * Check if this rule is a target to any of them. If so,
466 * disable them. As this operation is eventually very
467 * expensive, it is only performed if goto rules have
468 * actually been added.
470 if (ops
->nr_goto_rules
> 0) {
471 list_for_each_entry(tmp
, &ops
->rules_list
, list
) {
472 if (tmp
->ctarget
== rule
) {
473 rcu_assign_pointer(tmp
->ctarget
, NULL
);
474 ops
->unresolved_rules
++;
480 notify_rule_change(RTM_DELRULE
, rule
, ops
, nlh
,
481 NETLINK_CB(skb
).pid
);
483 flush_route_cache(ops
);
494 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops
*ops
,
495 struct fib_rule
*rule
)
497 size_t payload
= NLMSG_ALIGN(sizeof(struct fib_rule_hdr
))
498 + nla_total_size(IFNAMSIZ
) /* FRA_IIFNAME */
499 + nla_total_size(IFNAMSIZ
) /* FRA_OIFNAME */
500 + nla_total_size(4) /* FRA_PRIORITY */
501 + nla_total_size(4) /* FRA_TABLE */
502 + nla_total_size(4) /* FRA_FWMARK */
503 + nla_total_size(4); /* FRA_FWMASK */
505 if (ops
->nlmsg_payload
)
506 payload
+= ops
->nlmsg_payload(rule
);
511 static int fib_nl_fill_rule(struct sk_buff
*skb
, struct fib_rule
*rule
,
512 u32 pid
, u32 seq
, int type
, int flags
,
513 struct fib_rules_ops
*ops
)
515 struct nlmsghdr
*nlh
;
516 struct fib_rule_hdr
*frh
;
518 nlh
= nlmsg_put(skb
, pid
, seq
, type
, sizeof(*frh
), flags
);
522 frh
= nlmsg_data(nlh
);
523 frh
->table
= rule
->table
;
524 NLA_PUT_U32(skb
, FRA_TABLE
, rule
->table
);
527 frh
->action
= rule
->action
;
528 frh
->flags
= rule
->flags
;
530 if (rule
->action
== FR_ACT_GOTO
&& rule
->ctarget
== NULL
)
531 frh
->flags
|= FIB_RULE_UNRESOLVED
;
533 if (rule
->iifname
[0]) {
534 NLA_PUT_STRING(skb
, FRA_IIFNAME
, rule
->iifname
);
536 if (rule
->iifindex
== -1)
537 frh
->flags
|= FIB_RULE_IIF_DETACHED
;
540 if (rule
->oifname
[0]) {
541 NLA_PUT_STRING(skb
, FRA_OIFNAME
, rule
->oifname
);
543 if (rule
->oifindex
== -1)
544 frh
->flags
|= FIB_RULE_OIF_DETACHED
;
548 NLA_PUT_U32(skb
, FRA_PRIORITY
, rule
->pref
);
551 NLA_PUT_U32(skb
, FRA_FWMARK
, rule
->mark
);
553 if (rule
->mark_mask
|| rule
->mark
)
554 NLA_PUT_U32(skb
, FRA_FWMASK
, rule
->mark_mask
);
557 NLA_PUT_U32(skb
, FRA_GOTO
, rule
->target
);
559 if (ops
->fill(rule
, skb
, frh
) < 0)
560 goto nla_put_failure
;
562 return nlmsg_end(skb
, nlh
);
565 nlmsg_cancel(skb
, nlh
);
569 static int dump_rules(struct sk_buff
*skb
, struct netlink_callback
*cb
,
570 struct fib_rules_ops
*ops
)
573 struct fib_rule
*rule
;
575 list_for_each_entry(rule
, &ops
->rules_list
, list
) {
576 if (idx
< cb
->args
[1])
579 if (fib_nl_fill_rule(skb
, rule
, NETLINK_CB(cb
->skb
).pid
,
580 cb
->nlh
->nlmsg_seq
, RTM_NEWRULE
,
581 NLM_F_MULTI
, ops
) < 0)
592 static int fib_nl_dumprule(struct sk_buff
*skb
, struct netlink_callback
*cb
)
594 struct net
*net
= sock_net(skb
->sk
);
595 struct fib_rules_ops
*ops
;
598 family
= rtnl_msg_family(cb
->nlh
);
599 if (family
!= AF_UNSPEC
) {
600 /* Protocol specific dump request */
601 ops
= lookup_rules_ops(net
, family
);
603 return -EAFNOSUPPORT
;
605 return dump_rules(skb
, cb
, ops
);
609 list_for_each_entry_rcu(ops
, &net
->rules_ops
, list
) {
610 if (idx
< cb
->args
[0] || !try_module_get(ops
->owner
))
613 if (dump_rules(skb
, cb
, ops
) < 0)
626 static void notify_rule_change(int event
, struct fib_rule
*rule
,
627 struct fib_rules_ops
*ops
, struct nlmsghdr
*nlh
,
635 skb
= nlmsg_new(fib_rule_nlmsg_size(ops
, rule
), GFP_KERNEL
);
639 err
= fib_nl_fill_rule(skb
, rule
, pid
, nlh
->nlmsg_seq
, event
, 0, ops
);
641 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
642 WARN_ON(err
== -EMSGSIZE
);
647 rtnl_notify(skb
, net
, pid
, ops
->nlgroup
, nlh
, GFP_KERNEL
);
651 rtnl_set_sk_err(net
, ops
->nlgroup
, err
);
654 static void attach_rules(struct list_head
*rules
, struct net_device
*dev
)
656 struct fib_rule
*rule
;
658 list_for_each_entry(rule
, rules
, list
) {
659 if (rule
->iifindex
== -1 &&
660 strcmp(dev
->name
, rule
->iifname
) == 0)
661 rule
->iifindex
= dev
->ifindex
;
662 if (rule
->oifindex
== -1 &&
663 strcmp(dev
->name
, rule
->oifname
) == 0)
664 rule
->oifindex
= dev
->ifindex
;
668 static void detach_rules(struct list_head
*rules
, struct net_device
*dev
)
670 struct fib_rule
*rule
;
672 list_for_each_entry(rule
, rules
, list
) {
673 if (rule
->iifindex
== dev
->ifindex
)
675 if (rule
->oifindex
== dev
->ifindex
)
681 static int fib_rules_event(struct notifier_block
*this, unsigned long event
,
684 struct net_device
*dev
= ptr
;
685 struct net
*net
= dev_net(dev
);
686 struct fib_rules_ops
*ops
;
692 case NETDEV_REGISTER
:
693 list_for_each_entry(ops
, &net
->rules_ops
, list
)
694 attach_rules(&ops
->rules_list
, dev
);
697 case NETDEV_UNREGISTER
:
698 list_for_each_entry(ops
, &net
->rules_ops
, list
)
699 detach_rules(&ops
->rules_list
, dev
);
708 static struct notifier_block fib_rules_notifier
= {
709 .notifier_call
= fib_rules_event
,
712 static int __net_init
fib_rules_net_init(struct net
*net
)
714 INIT_LIST_HEAD(&net
->rules_ops
);
715 spin_lock_init(&net
->rules_mod_lock
);
719 static struct pernet_operations fib_rules_net_ops
= {
720 .init
= fib_rules_net_init
,
723 static int __init
fib_rules_init(void)
726 rtnl_register(PF_UNSPEC
, RTM_NEWRULE
, fib_nl_newrule
, NULL
);
727 rtnl_register(PF_UNSPEC
, RTM_DELRULE
, fib_nl_delrule
, NULL
);
728 rtnl_register(PF_UNSPEC
, RTM_GETRULE
, NULL
, fib_nl_dumprule
);
730 err
= register_pernet_subsys(&fib_rules_net_ops
);
734 err
= register_netdevice_notifier(&fib_rules_notifier
);
736 goto fail_unregister
;
741 unregister_pernet_subsys(&fib_rules_net_ops
);
743 rtnl_unregister(PF_UNSPEC
, RTM_NEWRULE
);
744 rtnl_unregister(PF_UNSPEC
, RTM_DELRULE
);
745 rtnl_unregister(PF_UNSPEC
, RTM_GETRULE
);
749 subsys_initcall(fib_rules_init
);