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/err.h>
23 #include <linux/skbuff.h>
24 #include <linux/init.h>
25 #include <linux/kmod.h>
26 #include <linux/err.h>
27 #include <linux/slab.h>
28 #include <net/net_namespace.h>
30 #include <net/netlink.h>
31 #include <net/pkt_sched.h>
32 #include <net/pkt_cls.h>
34 /* The list of all installed classifier types */
35 static LIST_HEAD(tcf_proto_base);
37 /* Protects list of registered TC modules. It is pure SMP lock. */
38 static DEFINE_RWLOCK(cls_mod_lock);
40 /* Find classifier type by string name */
42 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
44 const struct tcf_proto_ops *t, *res = NULL;
47 read_lock(&cls_mod_lock);
48 list_for_each_entry(t, &tcf_proto_base, head) {
49 if (strcmp(kind, t->kind) == 0) {
50 if (try_module_get(t->owner))
55 read_unlock(&cls_mod_lock);
60 /* Register(unregister) new classifier type */
62 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
64 struct tcf_proto_ops *t;
67 write_lock(&cls_mod_lock);
68 list_for_each_entry(t, &tcf_proto_base, head)
69 if (!strcmp(ops->kind, t->kind))
72 list_add_tail(&ops->head, &tcf_proto_base);
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;
85 /* Wait for outstanding call_rcu()s, if any, from a
86 * tcf_proto_ops's destroy() handler.
90 write_lock(&cls_mod_lock);
91 list_for_each_entry(t, &tcf_proto_base, head) {
98 write_unlock(&cls_mod_lock);
101 EXPORT_SYMBOL(unregister_tcf_proto_ops);
103 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
104 struct nlmsghdr *n, struct tcf_proto *tp,
105 unsigned long fh, int event, bool unicast);
107 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
109 struct tcf_proto __rcu **chain, int event)
111 struct tcf_proto __rcu **it_chain;
112 struct tcf_proto *tp;
114 for (it_chain = chain; (tp = rtnl_dereference(*it_chain)) != NULL;
115 it_chain = &tp->next)
116 tfilter_notify(net, oskb, n, tp, 0, event, false);
119 /* Select new prio value from the range, managed by kernel. */
121 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
123 u32 first = TC_H_MAKE(0xC0000000U, 0U);
126 first = tp->prio - 1;
131 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
132 u32 prio, u32 parent, struct Qdisc *q)
134 struct tcf_proto *tp;
137 tp = kzalloc(sizeof(*tp), GFP_KERNEL);
139 return ERR_PTR(-ENOBUFS);
142 tp->ops = tcf_proto_lookup_ops(kind);
144 #ifdef CONFIG_MODULES
146 request_module("cls_%s", kind);
148 tp->ops = tcf_proto_lookup_ops(kind);
149 /* We dropped the RTNL semaphore in order to perform
150 * the module load. So, even if we succeeded in loading
151 * the module we have to replay the request. We indicate
152 * this using -EAGAIN.
155 module_put(tp->ops->owner);
163 tp->classify = tp->ops->classify;
164 tp->protocol = protocol;
166 tp->classid = parent;
169 err = tp->ops->init(tp);
171 module_put(tp->ops->owner);
181 static void tcf_proto_destroy(struct tcf_proto *tp)
183 tp->ops->destroy(tp);
184 module_put(tp->ops->owner);
188 void tcf_destroy_chain(struct tcf_proto __rcu **fl)
190 struct tcf_proto *tp;
192 while ((tp = rtnl_dereference(*fl)) != NULL) {
193 RCU_INIT_POINTER(*fl, tp->next);
194 tcf_proto_destroy(tp);
197 EXPORT_SYMBOL(tcf_destroy_chain);
199 /* Add/change/delete/get a filter node */
201 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
202 struct netlink_ext_ack *extack)
204 struct net *net = sock_net(skb->sk);
205 struct nlattr *tca[TCA_MAX + 1];
211 struct net_device *dev;
213 struct tcf_proto __rcu **back;
214 struct tcf_proto __rcu **chain;
215 struct tcf_proto *next;
216 struct tcf_proto *tp;
217 const struct Qdisc_class_ops *cops;
223 if ((n->nlmsg_type != RTM_GETTFILTER) &&
224 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
230 err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack);
235 protocol = TC_H_MIN(t->tcm_info);
236 prio = TC_H_MAJ(t->tcm_info);
238 parent = t->tcm_parent;
242 switch (n->nlmsg_type) {
244 if (protocol || t->tcm_handle || tca[TCA_KIND])
248 /* If no priority is provided by the user,
251 if (n->nlmsg_flags & NLM_F_CREATE) {
252 prio = TC_H_MAKE(0x80000000U, 0U);
261 /* Find head of filter chain. */
264 dev = __dev_get_by_index(net, t->tcm_ifindex);
273 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
278 /* Is it classful? */
279 cops = q->ops->cl_ops;
283 if (cops->tcf_chain == NULL)
286 /* Do we search for filter, attached to class? */
287 if (TC_H_MIN(parent)) {
288 cl = cops->get(q, parent);
293 /* And the last stroke */
294 chain = cops->tcf_chain(q, cl);
299 if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
300 tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER);
301 tcf_destroy_chain(chain);
306 /* Check the chain for existence of proto-tcf with this priority */
308 (tp = rtnl_dereference(*back)) != NULL;
310 if (tp->prio >= prio) {
311 if (tp->prio == prio) {
313 (tp->protocol != protocol && protocol)) {
325 /* Proto-tcf does not exist, create new one */
327 if (tca[TCA_KIND] == NULL || !protocol) {
332 if (n->nlmsg_type != RTM_NEWTFILTER ||
333 !(n->nlmsg_flags & NLM_F_CREATE)) {
339 nprio = TC_H_MAJ(tcf_auto_prio(rtnl_dereference(*back)));
341 tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
342 protocol, nprio, parent, q);
348 } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
353 fh = tp->ops->get(tp, t->tcm_handle);
356 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
357 next = rtnl_dereference(tp->next);
358 RCU_INIT_POINTER(*back, next);
359 tfilter_notify(net, skb, n, tp, fh,
360 RTM_DELTFILTER, false);
361 tcf_proto_destroy(tp);
366 if (n->nlmsg_type != RTM_NEWTFILTER ||
367 !(n->nlmsg_flags & NLM_F_CREATE)) {
374 switch (n->nlmsg_type) {
376 if (n->nlmsg_flags & NLM_F_EXCL) {
378 tcf_proto_destroy(tp);
384 err = tp->ops->delete(tp, fh, &last);
387 next = rtnl_dereference(tp->next);
388 tfilter_notify(net, skb, n, tp, t->tcm_handle,
389 RTM_DELTFILTER, false);
391 RCU_INIT_POINTER(*back, next);
392 tcf_proto_destroy(tp);
396 err = tfilter_notify(net, skb, n, tp, fh,
397 RTM_NEWTFILTER, true);
405 err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
406 n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
409 RCU_INIT_POINTER(tp->next, rtnl_dereference(*back));
410 rcu_assign_pointer(*back, tp);
412 tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false);
415 tcf_proto_destroy(tp);
422 /* Replay the request. */
427 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
428 struct tcf_proto *tp, unsigned long fh, u32 portid,
429 u32 seq, u16 flags, int event)
432 struct nlmsghdr *nlh;
433 unsigned char *b = skb_tail_pointer(skb);
435 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
438 tcm = nlmsg_data(nlh);
439 tcm->tcm_family = AF_UNSPEC;
442 tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex;
443 tcm->tcm_parent = tp->classid;
444 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
445 if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
446 goto nla_put_failure;
447 tcm->tcm_handle = fh;
448 if (RTM_DELTFILTER != event) {
450 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
451 goto nla_put_failure;
453 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
462 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
463 struct nlmsghdr *n, struct tcf_proto *tp,
464 unsigned long fh, int event, bool unicast)
467 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
469 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
473 if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq,
474 n->nlmsg_flags, event) <= 0) {
480 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
482 return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
483 n->nlmsg_flags & NLM_F_ECHO);
486 struct tcf_dump_args {
489 struct netlink_callback *cb;
492 static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
493 struct tcf_walker *arg)
495 struct tcf_dump_args *a = (void *)arg;
496 struct net *net = sock_net(a->skb->sk);
498 return tcf_fill_node(net, a->skb, tp, n, NETLINK_CB(a->cb->skb).portid,
499 a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
503 /* called with RTNL */
504 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
506 struct net *net = sock_net(skb->sk);
509 struct net_device *dev;
511 struct tcf_proto *tp, __rcu **chain;
512 struct tcmsg *tcm = nlmsg_data(cb->nlh);
513 unsigned long cl = 0;
514 const struct Qdisc_class_ops *cops;
515 struct tcf_dump_args arg;
517 if (nlmsg_len(cb->nlh) < sizeof(*tcm))
519 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
523 if (!tcm->tcm_parent)
526 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
529 cops = q->ops->cl_ops;
532 if (cops->tcf_chain == NULL)
534 if (TC_H_MIN(tcm->tcm_parent)) {
535 cl = cops->get(q, tcm->tcm_parent);
539 chain = cops->tcf_chain(q, cl);
545 for (tp = rtnl_dereference(*chain), t = 0;
546 tp; tp = rtnl_dereference(tp->next), t++) {
549 if (TC_H_MAJ(tcm->tcm_info) &&
550 TC_H_MAJ(tcm->tcm_info) != tp->prio)
552 if (TC_H_MIN(tcm->tcm_info) &&
553 TC_H_MIN(tcm->tcm_info) != tp->protocol)
556 memset(&cb->args[1], 0,
557 sizeof(cb->args)-sizeof(cb->args[0]));
558 if (cb->args[1] == 0) {
559 if (tcf_fill_node(net, skb, tp, 0,
560 NETLINK_CB(cb->skb).portid,
561 cb->nlh->nlmsg_seq, NLM_F_MULTI,
562 RTM_NEWTFILTER) <= 0)
567 if (tp->ops->walk == NULL)
569 arg.w.fn = tcf_node_dump;
573 arg.w.skip = cb->args[1] - 1;
575 tp->ops->walk(tp, &arg.w);
576 cb->args[1] = arg.w.count + 1;
590 void tcf_exts_destroy(struct tcf_exts *exts)
592 #ifdef CONFIG_NET_CLS_ACT
595 tcf_exts_to_list(exts, &actions);
596 tcf_action_destroy(&actions, TCA_ACT_UNBIND);
597 kfree(exts->actions);
598 exts->nr_actions = 0;
601 EXPORT_SYMBOL(tcf_exts_destroy);
603 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
604 struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
606 #ifdef CONFIG_NET_CLS_ACT
608 struct tc_action *act;
610 if (exts->police && tb[exts->police]) {
611 act = tcf_action_init_1(net, tb[exts->police], rate_tlv,
612 "police", ovr, TCA_ACT_BIND);
616 act->type = exts->type = TCA_OLD_COMPAT;
617 exts->actions[0] = act;
618 exts->nr_actions = 1;
619 } else if (exts->action && tb[exts->action]) {
623 err = tcf_action_init(net, tb[exts->action], rate_tlv,
624 NULL, ovr, TCA_ACT_BIND,
628 list_for_each_entry(act, &actions, list)
629 exts->actions[i++] = act;
630 exts->nr_actions = i;
634 if ((exts->action && tb[exts->action]) ||
635 (exts->police && tb[exts->police]))
641 EXPORT_SYMBOL(tcf_exts_validate);
643 void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
644 struct tcf_exts *src)
646 #ifdef CONFIG_NET_CLS_ACT
647 struct tcf_exts old = *dst;
650 dst->nr_actions = src->nr_actions;
651 dst->actions = src->actions;
652 dst->type = src->type;
655 tcf_exts_destroy(&old);
658 EXPORT_SYMBOL(tcf_exts_change);
660 #ifdef CONFIG_NET_CLS_ACT
661 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
663 if (exts->nr_actions == 0)
666 return exts->actions[0];
670 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
672 #ifdef CONFIG_NET_CLS_ACT
675 if (exts->action && exts->nr_actions) {
677 * again for backward compatible mode - we want
678 * to work with both old and new modes of entering
679 * tc data even if iproute2 was newer - jhs
681 if (exts->type != TCA_OLD_COMPAT) {
684 nest = nla_nest_start(skb, exts->action);
686 goto nla_put_failure;
688 tcf_exts_to_list(exts, &actions);
689 if (tcf_action_dump(skb, &actions, 0, 0) < 0)
690 goto nla_put_failure;
691 nla_nest_end(skb, nest);
692 } else if (exts->police) {
693 struct tc_action *act = tcf_exts_first_act(exts);
694 nest = nla_nest_start(skb, exts->police);
695 if (nest == NULL || !act)
696 goto nla_put_failure;
697 if (tcf_action_dump_old(skb, act, 0, 0) < 0)
698 goto nla_put_failure;
699 nla_nest_end(skb, nest);
705 nla_nest_cancel(skb, nest);
711 EXPORT_SYMBOL(tcf_exts_dump);
714 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
716 #ifdef CONFIG_NET_CLS_ACT
717 struct tc_action *a = tcf_exts_first_act(exts);
718 if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
723 EXPORT_SYMBOL(tcf_exts_dump_stats);
725 int tcf_exts_get_dev(struct net_device *dev, struct tcf_exts *exts,
726 struct net_device **hw_dev)
728 #ifdef CONFIG_NET_CLS_ACT
729 const struct tc_action *a;
732 if (tc_no_actions(exts))
735 tcf_exts_to_list(exts, &actions);
736 list_for_each_entry(a, &actions, list) {
737 if (a->ops->get_dev) {
738 a->ops->get_dev(a, dev_net(dev), hw_dev);
747 EXPORT_SYMBOL(tcf_exts_get_dev);
749 static int __init tc_filter_init(void)
751 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, NULL);
752 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, NULL);
753 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
754 tc_dump_tfilter, NULL);
759 subsys_initcall(tc_filter_init);