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
) {
150 err
= ops
->action(rule
, fl
, flags
, arg
);
152 if (err
!= -EAGAIN
) {
166 EXPORT_SYMBOL_GPL(fib_rules_lookup
);
168 static int validate_rulemsg(struct fib_rule_hdr
*frh
, struct nlattr
**tb
,
169 struct fib_rules_ops
*ops
)
174 if (tb
[FRA_SRC
] == NULL
||
175 frh
->src_len
> (ops
->addr_size
* 8) ||
176 nla_len(tb
[FRA_SRC
]) != ops
->addr_size
)
180 if (tb
[FRA_DST
] == NULL
||
181 frh
->dst_len
> (ops
->addr_size
* 8) ||
182 nla_len(tb
[FRA_DST
]) != ops
->addr_size
)
190 static int fib_nl_newrule(struct sk_buff
*skb
, struct nlmsghdr
* nlh
, void *arg
)
192 struct fib_rule_hdr
*frh
= nlmsg_data(nlh
);
193 struct fib_rules_ops
*ops
= NULL
;
194 struct fib_rule
*rule
, *r
, *last
= NULL
;
195 struct nlattr
*tb
[FRA_MAX
+1];
196 int err
= -EINVAL
, unresolved
= 0;
198 if (nlh
->nlmsg_len
< nlmsg_msg_size(sizeof(*frh
)))
201 ops
= lookup_rules_ops(frh
->family
);
207 err
= nlmsg_parse(nlh
, sizeof(*frh
), tb
, FRA_MAX
, ops
->policy
);
211 err
= validate_rulemsg(frh
, tb
, ops
);
215 rule
= kzalloc(ops
->rule_size
, GFP_KERNEL
);
221 if (tb
[FRA_PRIORITY
])
222 rule
->pref
= nla_get_u32(tb
[FRA_PRIORITY
]);
224 if (tb
[FRA_IFNAME
]) {
225 struct net_device
*dev
;
228 nla_strlcpy(rule
->ifname
, tb
[FRA_IFNAME
], IFNAMSIZ
);
229 dev
= __dev_get_by_name(rule
->ifname
);
231 rule
->ifindex
= dev
->ifindex
;
234 if (tb
[FRA_FWMARK
]) {
235 rule
->mark
= nla_get_u32(tb
[FRA_FWMARK
]);
237 /* compatibility: if the mark value is non-zero all bits
238 * are compared unless a mask is explicitly specified.
240 rule
->mark_mask
= 0xFFFFFFFF;
244 rule
->mark_mask
= nla_get_u32(tb
[FRA_FWMASK
]);
246 rule
->action
= frh
->action
;
247 rule
->flags
= frh
->flags
;
248 rule
->table
= frh_get_table(frh
, tb
);
250 if (!rule
->pref
&& ops
->default_pref
)
251 rule
->pref
= ops
->default_pref();
255 if (rule
->action
!= FR_ACT_GOTO
)
258 rule
->target
= nla_get_u32(tb
[FRA_GOTO
]);
259 /* Backward jumps are prohibited to avoid endless loops */
260 if (rule
->target
<= rule
->pref
)
263 list_for_each_entry(r
, ops
->rules_list
, list
) {
264 if (r
->pref
== rule
->target
) {
270 if (rule
->ctarget
== NULL
)
272 } else if (rule
->action
== FR_ACT_GOTO
)
275 err
= ops
->configure(rule
, skb
, nlh
, frh
, tb
);
279 list_for_each_entry(r
, ops
->rules_list
, list
) {
280 if (r
->pref
> rule
->pref
)
287 if (ops
->unresolved_rules
) {
289 * There are unresolved goto rules in the list, check if
290 * any of them are pointing to this new rule.
292 list_for_each_entry(r
, ops
->rules_list
, list
) {
293 if (r
->action
== FR_ACT_GOTO
&&
294 r
->target
== rule
->pref
) {
295 BUG_ON(r
->ctarget
!= NULL
);
296 rcu_assign_pointer(r
->ctarget
, rule
);
297 if (--ops
->unresolved_rules
== 0)
303 if (rule
->action
== FR_ACT_GOTO
)
304 ops
->nr_goto_rules
++;
307 ops
->unresolved_rules
++;
310 list_add_rcu(&rule
->list
, &last
->list
);
312 list_add_rcu(&rule
->list
, ops
->rules_list
);
314 notify_rule_change(RTM_NEWRULE
, rule
, ops
, nlh
, NETLINK_CB(skb
).pid
);
325 static int fib_nl_delrule(struct sk_buff
*skb
, struct nlmsghdr
* nlh
, void *arg
)
327 struct fib_rule_hdr
*frh
= nlmsg_data(nlh
);
328 struct fib_rules_ops
*ops
= NULL
;
329 struct fib_rule
*rule
, *tmp
;
330 struct nlattr
*tb
[FRA_MAX
+1];
333 if (nlh
->nlmsg_len
< nlmsg_msg_size(sizeof(*frh
)))
336 ops
= lookup_rules_ops(frh
->family
);
342 err
= nlmsg_parse(nlh
, sizeof(*frh
), tb
, FRA_MAX
, ops
->policy
);
346 err
= validate_rulemsg(frh
, tb
, ops
);
350 list_for_each_entry(rule
, ops
->rules_list
, list
) {
351 if (frh
->action
&& (frh
->action
!= rule
->action
))
354 if (frh
->table
&& (frh_get_table(frh
, tb
) != rule
->table
))
357 if (tb
[FRA_PRIORITY
] &&
358 (rule
->pref
!= nla_get_u32(tb
[FRA_PRIORITY
])))
361 if (tb
[FRA_IFNAME
] &&
362 nla_strcmp(tb
[FRA_IFNAME
], rule
->ifname
))
365 if (tb
[FRA_FWMARK
] &&
366 (rule
->mark
!= nla_get_u32(tb
[FRA_FWMARK
])))
369 if (tb
[FRA_FWMASK
] &&
370 (rule
->mark_mask
!= nla_get_u32(tb
[FRA_FWMASK
])))
373 if (!ops
->compare(rule
, frh
, tb
))
376 if (rule
->flags
& FIB_RULE_PERMANENT
) {
381 list_del_rcu(&rule
->list
);
383 if (rule
->action
== FR_ACT_GOTO
)
384 ops
->nr_goto_rules
--;
387 * Check if this rule is a target to any of them. If so,
388 * disable them. As this operation is eventually very
389 * expensive, it is only performed if goto rules have
390 * actually been added.
392 if (ops
->nr_goto_rules
> 0) {
393 list_for_each_entry(tmp
, ops
->rules_list
, list
) {
394 if (tmp
->ctarget
== rule
) {
395 rcu_assign_pointer(tmp
->ctarget
, NULL
);
396 ops
->unresolved_rules
++;
402 notify_rule_change(RTM_DELRULE
, rule
, ops
, nlh
,
403 NETLINK_CB(skb
).pid
);
415 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops
*ops
,
416 struct fib_rule
*rule
)
418 size_t payload
= NLMSG_ALIGN(sizeof(struct fib_rule_hdr
))
419 + nla_total_size(IFNAMSIZ
) /* FRA_IFNAME */
420 + nla_total_size(4) /* FRA_PRIORITY */
421 + nla_total_size(4) /* FRA_TABLE */
422 + nla_total_size(4) /* FRA_FWMARK */
423 + nla_total_size(4); /* FRA_FWMASK */
425 if (ops
->nlmsg_payload
)
426 payload
+= ops
->nlmsg_payload(rule
);
431 static int fib_nl_fill_rule(struct sk_buff
*skb
, struct fib_rule
*rule
,
432 u32 pid
, u32 seq
, int type
, int flags
,
433 struct fib_rules_ops
*ops
)
435 struct nlmsghdr
*nlh
;
436 struct fib_rule_hdr
*frh
;
438 nlh
= nlmsg_put(skb
, pid
, seq
, type
, sizeof(*frh
), flags
);
442 frh
= nlmsg_data(nlh
);
443 frh
->table
= rule
->table
;
444 NLA_PUT_U32(skb
, FRA_TABLE
, rule
->table
);
447 frh
->action
= rule
->action
;
448 frh
->flags
= rule
->flags
;
450 if (rule
->action
== FR_ACT_GOTO
&& rule
->ctarget
== NULL
)
451 frh
->flags
|= FIB_RULE_UNRESOLVED
;
454 NLA_PUT_STRING(skb
, FRA_IFNAME
, rule
->ifname
);
457 NLA_PUT_U32(skb
, FRA_PRIORITY
, rule
->pref
);
460 NLA_PUT_U32(skb
, FRA_FWMARK
, rule
->mark
);
462 if (rule
->mark_mask
|| rule
->mark
)
463 NLA_PUT_U32(skb
, FRA_FWMASK
, rule
->mark_mask
);
466 NLA_PUT_U32(skb
, FRA_GOTO
, rule
->target
);
468 if (ops
->fill(rule
, skb
, nlh
, frh
) < 0)
469 goto nla_put_failure
;
471 return nlmsg_end(skb
, nlh
);
474 nlmsg_cancel(skb
, nlh
);
478 static int dump_rules(struct sk_buff
*skb
, struct netlink_callback
*cb
,
479 struct fib_rules_ops
*ops
)
482 struct fib_rule
*rule
;
485 list_for_each_entry_rcu(rule
, ops
->rules_list
, list
) {
486 if (idx
< cb
->args
[1])
489 if (fib_nl_fill_rule(skb
, rule
, NETLINK_CB(cb
->skb
).pid
,
490 cb
->nlh
->nlmsg_seq
, RTM_NEWRULE
,
491 NLM_F_MULTI
, ops
) < 0)
503 static int fib_nl_dumprule(struct sk_buff
*skb
, struct netlink_callback
*cb
)
505 struct fib_rules_ops
*ops
;
508 family
= rtnl_msg_family(cb
->nlh
);
509 if (family
!= AF_UNSPEC
) {
510 /* Protocol specific dump request */
511 ops
= lookup_rules_ops(family
);
513 return -EAFNOSUPPORT
;
515 return dump_rules(skb
, cb
, ops
);
519 list_for_each_entry_rcu(ops
, &rules_ops
, list
) {
520 if (idx
< cb
->args
[0] || !try_module_get(ops
->owner
))
523 if (dump_rules(skb
, cb
, ops
) < 0)
536 static void notify_rule_change(int event
, struct fib_rule
*rule
,
537 struct fib_rules_ops
*ops
, struct nlmsghdr
*nlh
,
543 skb
= nlmsg_new(fib_rule_nlmsg_size(ops
, rule
), GFP_KERNEL
);
547 err
= fib_nl_fill_rule(skb
, rule
, pid
, nlh
->nlmsg_seq
, event
, 0, ops
);
549 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
550 WARN_ON(err
== -EMSGSIZE
);
554 err
= rtnl_notify(skb
, pid
, ops
->nlgroup
, nlh
, GFP_KERNEL
);
557 rtnl_set_sk_err(ops
->nlgroup
, err
);
560 static void attach_rules(struct list_head
*rules
, struct net_device
*dev
)
562 struct fib_rule
*rule
;
564 list_for_each_entry(rule
, rules
, list
) {
565 if (rule
->ifindex
== -1 &&
566 strcmp(dev
->name
, rule
->ifname
) == 0)
567 rule
->ifindex
= dev
->ifindex
;
571 static void detach_rules(struct list_head
*rules
, struct net_device
*dev
)
573 struct fib_rule
*rule
;
575 list_for_each_entry(rule
, rules
, list
)
576 if (rule
->ifindex
== dev
->ifindex
)
581 static int fib_rules_event(struct notifier_block
*this, unsigned long event
,
584 struct net_device
*dev
= ptr
;
585 struct fib_rules_ops
*ops
;
591 case NETDEV_REGISTER
:
592 list_for_each_entry(ops
, &rules_ops
, list
)
593 attach_rules(ops
->rules_list
, dev
);
596 case NETDEV_UNREGISTER
:
597 list_for_each_entry(ops
, &rules_ops
, list
)
598 detach_rules(ops
->rules_list
, dev
);
607 static struct notifier_block fib_rules_notifier
= {
608 .notifier_call
= fib_rules_event
,
611 static int __init
fib_rules_init(void)
613 rtnl_register(PF_UNSPEC
, RTM_NEWRULE
, fib_nl_newrule
, NULL
);
614 rtnl_register(PF_UNSPEC
, RTM_DELRULE
, fib_nl_delrule
, NULL
);
615 rtnl_register(PF_UNSPEC
, RTM_GETRULE
, NULL
, fib_nl_dumprule
);
617 return register_netdevice_notifier(&fib_rules_notifier
);
620 subsys_initcall(fib_rules_init
);