2 * net/sched/cls_api.c Packet classifier API.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/skbuff.h>
23 #include <linux/init.h>
24 #include <linux/kmod.h>
25 #include <linux/netlink.h>
26 #include <net/net_namespace.h>
28 #include <net/netlink.h>
29 #include <net/pkt_sched.h>
30 #include <net/pkt_cls.h>
32 /* The list of all installed classifier types */
34 static struct tcf_proto_ops *tcf_proto_base __read_mostly;
36 /* Protects list of registered TC modules. It is pure SMP lock. */
37 static DEFINE_RWLOCK(cls_mod_lock);
39 /* Find classifier type by string name */
41 static struct tcf_proto_ops *tcf_proto_lookup_ops(struct rtattr *kind)
43 struct tcf_proto_ops *t = NULL;
46 read_lock(&cls_mod_lock);
47 for (t = tcf_proto_base; t; t = t->next) {
48 if (rtattr_strcmp(kind, t->kind) == 0) {
49 if (!try_module_get(t->owner))
54 read_unlock(&cls_mod_lock);
59 /* Register(unregister) new classifier type */
61 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
63 struct tcf_proto_ops *t, **tp;
66 write_lock(&cls_mod_lock);
67 for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
68 if (!strcmp(ops->kind, t->kind))
75 write_unlock(&cls_mod_lock);
78 EXPORT_SYMBOL(register_tcf_proto_ops);
80 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
82 struct tcf_proto_ops *t, **tp;
85 write_lock(&cls_mod_lock);
86 for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next)
95 write_unlock(&cls_mod_lock);
98 EXPORT_SYMBOL(unregister_tcf_proto_ops);
100 static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
101 struct tcf_proto *tp, unsigned long fh, int event);
104 /* Select new prio value from the range, managed by kernel. */
106 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
108 u32 first = TC_H_MAKE(0xC0000000U, 0U);
116 /* Add/change/delete/get a filter node */
118 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
120 struct net *net = skb->sk->sk_net;
127 struct net_device *dev;
129 struct tcf_proto **back, **chain;
130 struct tcf_proto *tp;
131 struct tcf_proto_ops *tp_ops;
132 const struct Qdisc_class_ops *cops;
137 if (net != &init_net)
143 protocol = TC_H_MIN(t->tcm_info);
144 prio = TC_H_MAJ(t->tcm_info);
146 parent = t->tcm_parent;
150 /* If no priority is given, user wants we allocated it. */
151 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
153 prio = TC_H_MAKE(0x80000000U, 0U);
156 /* Find head of filter chain. */
159 dev = __dev_get_by_index(&init_net, t->tcm_ifindex);
165 q = dev->qdisc_sleeping;
168 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
173 /* Is it classful? */
174 if ((cops = q->ops->cl_ops) == NULL)
177 /* Do we search for filter, attached to class? */
178 if (TC_H_MIN(parent)) {
179 cl = cops->get(q, parent);
184 /* And the last stroke */
185 chain = cops->tcf_chain(q, cl);
190 /* Check the chain for existence of proto-tcf with this priority */
191 for (back = chain; (tp=*back) != NULL; back = &tp->next) {
192 if (tp->prio >= prio) {
193 if (tp->prio == prio) {
194 if (!nprio || (tp->protocol != protocol && protocol))
203 /* Proto-tcf does not exist, create new one */
205 if (tca[TCA_KIND-1] == NULL || !protocol)
209 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
213 /* Create new proto tcf */
216 tp = kzalloc(sizeof(*tp), GFP_KERNEL);
220 tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]);
221 if (tp_ops == NULL) {
223 struct rtattr *kind = tca[TCA_KIND-1];
227 rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
229 request_module("cls_%s", name);
231 tp_ops = tcf_proto_lookup_ops(kind);
232 /* We dropped the RTNL semaphore in order to
233 * perform the module load. So, even if we
234 * succeeded in loading the module we have to
235 * replay the request. We indicate this using
238 if (tp_ops != NULL) {
239 module_put(tp_ops->owner);
248 tp->protocol = protocol;
249 tp->prio = nprio ? : tcf_auto_prio(*back);
251 tp->classify = tp_ops->classify;
252 tp->classid = parent;
254 err = tp_ops->init(tp);
256 module_put(tp_ops->owner);
261 qdisc_lock_tree(dev);
264 qdisc_unlock_tree(dev);
266 } else if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], tp->ops->kind))
269 fh = tp->ops->get(tp, t->tcm_handle);
272 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
273 qdisc_lock_tree(dev);
275 qdisc_unlock_tree(dev);
277 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
284 if (n->nlmsg_type != RTM_NEWTFILTER ||
285 !(n->nlmsg_flags & NLM_F_CREATE))
288 switch (n->nlmsg_type) {
291 if (n->nlmsg_flags & NLM_F_EXCL)
295 err = tp->ops->delete(tp, fh);
297 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
300 err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
308 err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
310 tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
316 /* Replay the request. */
321 static int tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp,
322 unsigned long fh, u32 pid, u32 seq, u16 flags, int event)
325 struct nlmsghdr *nlh;
326 unsigned char *b = skb_tail_pointer(skb);
328 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
329 tcm = NLMSG_DATA(nlh);
330 tcm->tcm_family = AF_UNSPEC;
333 tcm->tcm_ifindex = tp->q->dev->ifindex;
334 tcm->tcm_parent = tp->classid;
335 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
336 RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind);
337 tcm->tcm_handle = fh;
338 if (RTM_DELTFILTER != event) {
340 if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
343 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
352 static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
353 struct tcf_proto *tp, unsigned long fh, int event)
356 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
358 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
362 if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
367 return rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
368 n->nlmsg_flags & NLM_F_ECHO);
371 struct tcf_dump_args {
374 struct netlink_callback *cb;
377 static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
378 struct tcf_walker *arg)
380 struct tcf_dump_args *a = (void *)arg;
382 return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
383 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
386 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
388 struct net *net = skb->sk->sk_net;
391 struct net_device *dev;
393 struct tcf_proto *tp, **chain;
394 struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
395 unsigned long cl = 0;
396 const struct Qdisc_class_ops *cops;
397 struct tcf_dump_args arg;
399 if (net != &init_net)
402 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
404 if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
407 if (!tcm->tcm_parent)
408 q = dev->qdisc_sleeping;
410 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
413 if ((cops = q->ops->cl_ops) == NULL)
415 if (TC_H_MIN(tcm->tcm_parent)) {
416 cl = cops->get(q, tcm->tcm_parent);
420 chain = cops->tcf_chain(q, cl);
426 for (tp=*chain, t=0; tp; tp = tp->next, t++) {
427 if (t < s_t) continue;
428 if (TC_H_MAJ(tcm->tcm_info) &&
429 TC_H_MAJ(tcm->tcm_info) != tp->prio)
431 if (TC_H_MIN(tcm->tcm_info) &&
432 TC_H_MIN(tcm->tcm_info) != tp->protocol)
435 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
436 if (cb->args[1] == 0) {
437 if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
438 cb->nlh->nlmsg_seq, NLM_F_MULTI,
439 RTM_NEWTFILTER) <= 0)
444 if (tp->ops->walk == NULL)
446 arg.w.fn = tcf_node_dump;
450 arg.w.skip = cb->args[1]-1;
452 tp->ops->walk(tp, &arg.w);
453 cb->args[1] = arg.w.count+1;
468 void tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts)
470 #ifdef CONFIG_NET_CLS_ACT
472 tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
477 EXPORT_SYMBOL(tcf_exts_destroy);
479 int tcf_exts_validate(struct tcf_proto *tp, struct rtattr **tb,
480 struct rtattr *rate_tlv, struct tcf_exts *exts,
481 struct tcf_ext_map *map)
483 memset(exts, 0, sizeof(*exts));
485 #ifdef CONFIG_NET_CLS_ACT
488 struct tc_action *act;
490 if (map->police && tb[map->police-1]) {
491 act = tcf_action_init_1(tb[map->police-1], rate_tlv,
492 "police", TCA_ACT_NOREPLACE,
497 act->type = TCA_OLD_COMPAT;
499 } else if (map->action && tb[map->action-1]) {
500 act = tcf_action_init(tb[map->action-1], rate_tlv, NULL,
501 TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
509 if ((map->action && tb[map->action-1]) ||
510 (map->police && tb[map->police-1]))
516 EXPORT_SYMBOL(tcf_exts_validate);
518 void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
519 struct tcf_exts *src)
521 #ifdef CONFIG_NET_CLS_ACT
523 struct tc_action *act;
525 act = xchg(&dst->action, src->action);
528 tcf_action_destroy(act, TCA_ACT_UNBIND);
532 EXPORT_SYMBOL(tcf_exts_change);
534 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts,
535 struct tcf_ext_map *map)
537 #ifdef CONFIG_NET_CLS_ACT
538 if (map->action && exts->action) {
540 * again for backward compatible mode - we want
541 * to work with both old and new modes of entering
542 * tc data even if iproute2 was newer - jhs
544 struct rtattr *p_rta = (struct rtattr *)skb_tail_pointer(skb);
546 if (exts->action->type != TCA_OLD_COMPAT) {
547 RTA_PUT(skb, map->action, 0, NULL);
548 if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
550 p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
551 } else if (map->police) {
552 RTA_PUT(skb, map->police, 0, NULL);
553 if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
555 p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
560 rtattr_failure: __attribute__ ((unused))
563 EXPORT_SYMBOL(tcf_exts_dump);
566 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts,
567 struct tcf_ext_map *map)
569 #ifdef CONFIG_NET_CLS_ACT
571 if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
575 rtattr_failure: __attribute__ ((unused))
578 EXPORT_SYMBOL(tcf_exts_dump_stats);
580 static int __init tc_filter_init(void)
582 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL);
583 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL);
584 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
590 subsys_initcall(tc_filter_init);