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/list.h>
14 #include <net/fib_rules.h>
16 static LIST_HEAD(rules_ops
);
17 static DEFINE_SPINLOCK(rules_mod_lock
);
19 static void notify_rule_change(int event
, struct fib_rule
*rule
,
20 struct fib_rules_ops
*ops
, struct nlmsghdr
*nlh
,
23 static struct fib_rules_ops
*lookup_rules_ops(int family
)
25 struct fib_rules_ops
*ops
;
28 list_for_each_entry_rcu(ops
, &rules_ops
, list
) {
29 if (ops
->family
== family
) {
30 if (!try_module_get(ops
->owner
))
41 static void rules_ops_put(struct fib_rules_ops
*ops
)
44 module_put(ops
->owner
);
47 int fib_rules_register(struct fib_rules_ops
*ops
)
50 struct fib_rules_ops
*o
;
52 if (ops
->rule_size
< sizeof(struct fib_rule
))
55 if (ops
->match
== NULL
|| ops
->configure
== NULL
||
56 ops
->compare
== NULL
|| ops
->fill
== NULL
||
60 spin_lock(&rules_mod_lock
);
61 list_for_each_entry(o
, &rules_ops
, list
)
62 if (ops
->family
== o
->family
)
65 list_add_tail_rcu(&ops
->list
, &rules_ops
);
68 spin_unlock(&rules_mod_lock
);
73 EXPORT_SYMBOL_GPL(fib_rules_register
);
75 static void cleanup_ops(struct fib_rules_ops
*ops
)
77 struct fib_rule
*rule
, *tmp
;
79 list_for_each_entry_safe(rule
, tmp
, ops
->rules_list
, list
) {
80 list_del_rcu(&rule
->list
);
85 int fib_rules_unregister(struct fib_rules_ops
*ops
)
88 struct fib_rules_ops
*o
;
90 spin_lock(&rules_mod_lock
);
91 list_for_each_entry(o
, &rules_ops
, list
) {
93 list_del_rcu(&o
->list
);
101 spin_unlock(&rules_mod_lock
);
108 EXPORT_SYMBOL_GPL(fib_rules_unregister
);
110 static int fib_rule_match(struct fib_rule
*rule
, struct fib_rules_ops
*ops
,
111 struct flowi
*fl
, int flags
)
115 if (rule
->ifindex
&& (rule
->ifindex
!= fl
->iif
))
118 if ((rule
->mark
^ fl
->mark
) & rule
->mark_mask
)
121 ret
= ops
->match(rule
, fl
, flags
);
123 return (rule
->flags
& FIB_RULE_INVERT
) ? !ret
: ret
;
126 int fib_rules_lookup(struct fib_rules_ops
*ops
, struct flowi
*fl
,
127 int flags
, struct fib_lookup_arg
*arg
)
129 struct fib_rule
*rule
;
134 list_for_each_entry_rcu(rule
, ops
->rules_list
, list
) {
136 if (!fib_rule_match(rule
, ops
, fl
, flags
))
139 if (rule
->action
== FR_ACT_GOTO
) {
140 struct fib_rule
*target
;
142 target
= rcu_dereference(rule
->ctarget
);
143 if (target
== NULL
) {
149 } else if (rule
->action
== FR_ACT_NOP
)
152 err
= ops
->action(rule
, fl
, flags
, arg
);
154 if (err
!= -EAGAIN
) {
168 EXPORT_SYMBOL_GPL(fib_rules_lookup
);
170 static int validate_rulemsg(struct fib_rule_hdr
*frh
, struct nlattr
**tb
,
171 struct fib_rules_ops
*ops
)
176 if (tb
[FRA_SRC
] == NULL
||
177 frh
->src_len
> (ops
->addr_size
* 8) ||
178 nla_len(tb
[FRA_SRC
]) != ops
->addr_size
)
182 if (tb
[FRA_DST
] == NULL
||
183 frh
->dst_len
> (ops
->addr_size
* 8) ||
184 nla_len(tb
[FRA_DST
]) != ops
->addr_size
)
192 static int fib_nl_newrule(struct sk_buff
*skb
, struct nlmsghdr
* nlh
, void *arg
)
194 struct fib_rule_hdr
*frh
= nlmsg_data(nlh
);
195 struct fib_rules_ops
*ops
= NULL
;
196 struct fib_rule
*rule
, *r
, *last
= NULL
;
197 struct nlattr
*tb
[FRA_MAX
+1];
198 int err
= -EINVAL
, unresolved
= 0;
200 if (nlh
->nlmsg_len
< nlmsg_msg_size(sizeof(*frh
)))
203 ops
= lookup_rules_ops(frh
->family
);
209 err
= nlmsg_parse(nlh
, sizeof(*frh
), tb
, FRA_MAX
, ops
->policy
);
213 err
= validate_rulemsg(frh
, tb
, ops
);
217 rule
= kzalloc(ops
->rule_size
, GFP_KERNEL
);
223 if (tb
[FRA_PRIORITY
])
224 rule
->pref
= nla_get_u32(tb
[FRA_PRIORITY
]);
226 if (tb
[FRA_IFNAME
]) {
227 struct net_device
*dev
;
230 nla_strlcpy(rule
->ifname
, tb
[FRA_IFNAME
], IFNAMSIZ
);
231 dev
= __dev_get_by_name(rule
->ifname
);
233 rule
->ifindex
= dev
->ifindex
;
236 if (tb
[FRA_FWMARK
]) {
237 rule
->mark
= nla_get_u32(tb
[FRA_FWMARK
]);
239 /* compatibility: if the mark value is non-zero all bits
240 * are compared unless a mask is explicitly specified.
242 rule
->mark_mask
= 0xFFFFFFFF;
246 rule
->mark_mask
= nla_get_u32(tb
[FRA_FWMASK
]);
248 rule
->action
= frh
->action
;
249 rule
->flags
= frh
->flags
;
250 rule
->table
= frh_get_table(frh
, tb
);
252 if (!rule
->pref
&& ops
->default_pref
)
253 rule
->pref
= ops
->default_pref();
257 if (rule
->action
!= FR_ACT_GOTO
)
260 rule
->target
= nla_get_u32(tb
[FRA_GOTO
]);
261 /* Backward jumps are prohibited to avoid endless loops */
262 if (rule
->target
<= rule
->pref
)
265 list_for_each_entry(r
, ops
->rules_list
, list
) {
266 if (r
->pref
== rule
->target
) {
272 if (rule
->ctarget
== NULL
)
274 } else if (rule
->action
== FR_ACT_GOTO
)
277 err
= ops
->configure(rule
, skb
, nlh
, frh
, tb
);
281 list_for_each_entry(r
, ops
->rules_list
, list
) {
282 if (r
->pref
> rule
->pref
)
289 if (ops
->unresolved_rules
) {
291 * There are unresolved goto rules in the list, check if
292 * any of them are pointing to this new rule.
294 list_for_each_entry(r
, ops
->rules_list
, list
) {
295 if (r
->action
== FR_ACT_GOTO
&&
296 r
->target
== rule
->pref
) {
297 BUG_ON(r
->ctarget
!= NULL
);
298 rcu_assign_pointer(r
->ctarget
, rule
);
299 if (--ops
->unresolved_rules
== 0)
305 if (rule
->action
== FR_ACT_GOTO
)
306 ops
->nr_goto_rules
++;
309 ops
->unresolved_rules
++;
312 list_add_rcu(&rule
->list
, &last
->list
);
314 list_add_rcu(&rule
->list
, ops
->rules_list
);
316 notify_rule_change(RTM_NEWRULE
, rule
, ops
, nlh
, NETLINK_CB(skb
).pid
);
327 static int fib_nl_delrule(struct sk_buff
*skb
, struct nlmsghdr
* nlh
, void *arg
)
329 struct fib_rule_hdr
*frh
= nlmsg_data(nlh
);
330 struct fib_rules_ops
*ops
= NULL
;
331 struct fib_rule
*rule
, *tmp
;
332 struct nlattr
*tb
[FRA_MAX
+1];
335 if (nlh
->nlmsg_len
< nlmsg_msg_size(sizeof(*frh
)))
338 ops
= lookup_rules_ops(frh
->family
);
344 err
= nlmsg_parse(nlh
, sizeof(*frh
), tb
, FRA_MAX
, ops
->policy
);
348 err
= validate_rulemsg(frh
, tb
, ops
);
352 list_for_each_entry(rule
, ops
->rules_list
, list
) {
353 if (frh
->action
&& (frh
->action
!= rule
->action
))
356 if (frh
->table
&& (frh_get_table(frh
, tb
) != rule
->table
))
359 if (tb
[FRA_PRIORITY
] &&
360 (rule
->pref
!= nla_get_u32(tb
[FRA_PRIORITY
])))
363 if (tb
[FRA_IFNAME
] &&
364 nla_strcmp(tb
[FRA_IFNAME
], rule
->ifname
))
367 if (tb
[FRA_FWMARK
] &&
368 (rule
->mark
!= nla_get_u32(tb
[FRA_FWMARK
])))
371 if (tb
[FRA_FWMASK
] &&
372 (rule
->mark_mask
!= nla_get_u32(tb
[FRA_FWMASK
])))
375 if (!ops
->compare(rule
, frh
, tb
))
378 if (rule
->flags
& FIB_RULE_PERMANENT
) {
383 list_del_rcu(&rule
->list
);
385 if (rule
->action
== FR_ACT_GOTO
)
386 ops
->nr_goto_rules
--;
389 * Check if this rule is a target to any of them. If so,
390 * disable them. As this operation is eventually very
391 * expensive, it is only performed if goto rules have
392 * actually been added.
394 if (ops
->nr_goto_rules
> 0) {
395 list_for_each_entry(tmp
, ops
->rules_list
, list
) {
396 if (tmp
->ctarget
== rule
) {
397 rcu_assign_pointer(tmp
->ctarget
, NULL
);
398 ops
->unresolved_rules
++;
404 notify_rule_change(RTM_DELRULE
, rule
, ops
, nlh
,
405 NETLINK_CB(skb
).pid
);
417 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops
*ops
,
418 struct fib_rule
*rule
)
420 size_t payload
= NLMSG_ALIGN(sizeof(struct fib_rule_hdr
))
421 + nla_total_size(IFNAMSIZ
) /* FRA_IFNAME */
422 + nla_total_size(4) /* FRA_PRIORITY */
423 + nla_total_size(4) /* FRA_TABLE */
424 + nla_total_size(4) /* FRA_FWMARK */
425 + nla_total_size(4); /* FRA_FWMASK */
427 if (ops
->nlmsg_payload
)
428 payload
+= ops
->nlmsg_payload(rule
);
433 static int fib_nl_fill_rule(struct sk_buff
*skb
, struct fib_rule
*rule
,
434 u32 pid
, u32 seq
, int type
, int flags
,
435 struct fib_rules_ops
*ops
)
437 struct nlmsghdr
*nlh
;
438 struct fib_rule_hdr
*frh
;
440 nlh
= nlmsg_put(skb
, pid
, seq
, type
, sizeof(*frh
), flags
);
444 frh
= nlmsg_data(nlh
);
445 frh
->table
= rule
->table
;
446 NLA_PUT_U32(skb
, FRA_TABLE
, rule
->table
);
449 frh
->action
= rule
->action
;
450 frh
->flags
= rule
->flags
;
452 if (rule
->action
== FR_ACT_GOTO
&& rule
->ctarget
== NULL
)
453 frh
->flags
|= FIB_RULE_UNRESOLVED
;
455 if (rule
->ifname
[0]) {
456 NLA_PUT_STRING(skb
, FRA_IFNAME
, rule
->ifname
);
458 if (rule
->ifindex
== -1)
459 frh
->flags
|= FIB_RULE_DEV_DETACHED
;
463 NLA_PUT_U32(skb
, FRA_PRIORITY
, rule
->pref
);
466 NLA_PUT_U32(skb
, FRA_FWMARK
, rule
->mark
);
468 if (rule
->mark_mask
|| rule
->mark
)
469 NLA_PUT_U32(skb
, FRA_FWMASK
, rule
->mark_mask
);
472 NLA_PUT_U32(skb
, FRA_GOTO
, rule
->target
);
474 if (ops
->fill(rule
, skb
, nlh
, frh
) < 0)
475 goto nla_put_failure
;
477 return nlmsg_end(skb
, nlh
);
480 nlmsg_cancel(skb
, nlh
);
484 static int dump_rules(struct sk_buff
*skb
, struct netlink_callback
*cb
,
485 struct fib_rules_ops
*ops
)
488 struct fib_rule
*rule
;
491 list_for_each_entry_rcu(rule
, ops
->rules_list
, list
) {
492 if (idx
< cb
->args
[1])
495 if (fib_nl_fill_rule(skb
, rule
, NETLINK_CB(cb
->skb
).pid
,
496 cb
->nlh
->nlmsg_seq
, RTM_NEWRULE
,
497 NLM_F_MULTI
, ops
) < 0)
509 static int fib_nl_dumprule(struct sk_buff
*skb
, struct netlink_callback
*cb
)
511 struct fib_rules_ops
*ops
;
514 family
= rtnl_msg_family(cb
->nlh
);
515 if (family
!= AF_UNSPEC
) {
516 /* Protocol specific dump request */
517 ops
= lookup_rules_ops(family
);
519 return -EAFNOSUPPORT
;
521 return dump_rules(skb
, cb
, ops
);
525 list_for_each_entry_rcu(ops
, &rules_ops
, list
) {
526 if (idx
< cb
->args
[0] || !try_module_get(ops
->owner
))
529 if (dump_rules(skb
, cb
, ops
) < 0)
542 static void notify_rule_change(int event
, struct fib_rule
*rule
,
543 struct fib_rules_ops
*ops
, struct nlmsghdr
*nlh
,
549 skb
= nlmsg_new(fib_rule_nlmsg_size(ops
, rule
), GFP_KERNEL
);
553 err
= fib_nl_fill_rule(skb
, rule
, pid
, nlh
->nlmsg_seq
, event
, 0, ops
);
555 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
556 WARN_ON(err
== -EMSGSIZE
);
560 err
= rtnl_notify(skb
, pid
, ops
->nlgroup
, nlh
, GFP_KERNEL
);
563 rtnl_set_sk_err(ops
->nlgroup
, err
);
566 static void attach_rules(struct list_head
*rules
, struct net_device
*dev
)
568 struct fib_rule
*rule
;
570 list_for_each_entry(rule
, rules
, list
) {
571 if (rule
->ifindex
== -1 &&
572 strcmp(dev
->name
, rule
->ifname
) == 0)
573 rule
->ifindex
= dev
->ifindex
;
577 static void detach_rules(struct list_head
*rules
, struct net_device
*dev
)
579 struct fib_rule
*rule
;
581 list_for_each_entry(rule
, rules
, list
)
582 if (rule
->ifindex
== dev
->ifindex
)
587 static int fib_rules_event(struct notifier_block
*this, unsigned long event
,
590 struct net_device
*dev
= ptr
;
591 struct fib_rules_ops
*ops
;
597 case NETDEV_REGISTER
:
598 list_for_each_entry(ops
, &rules_ops
, list
)
599 attach_rules(ops
->rules_list
, dev
);
602 case NETDEV_UNREGISTER
:
603 list_for_each_entry(ops
, &rules_ops
, list
)
604 detach_rules(ops
->rules_list
, dev
);
613 static struct notifier_block fib_rules_notifier
= {
614 .notifier_call
= fib_rules_event
,
617 static int __init
fib_rules_init(void)
619 rtnl_register(PF_UNSPEC
, RTM_NEWRULE
, fib_nl_newrule
, NULL
);
620 rtnl_register(PF_UNSPEC
, RTM_DELRULE
, fib_nl_delrule
, NULL
);
621 rtnl_register(PF_UNSPEC
, RTM_GETRULE
, NULL
, fib_nl_dumprule
);
623 return register_netdevice_notifier(&fib_rules_notifier
);
626 subsys_initcall(fib_rules_init
);