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 <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 */
36 static struct tcf_proto_ops *tcf_proto_base __read_mostly;
38 /* Protects list of registered TC modules. It is pure SMP lock. */
39 static DEFINE_RWLOCK(cls_mod_lock);
41 /* Find classifier type by string name */
43 static const struct tcf_proto_ops *tcf_proto_lookup_ops(struct nlattr *kind)
45 const struct tcf_proto_ops *t = NULL;
48 read_lock(&cls_mod_lock);
49 for (t = tcf_proto_base; t; t = t->next) {
50 if (nla_strcmp(kind, t->kind) == 0) {
51 if (!try_module_get(t->owner))
56 read_unlock(&cls_mod_lock);
61 /* Register(unregister) new classifier type */
63 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
65 struct tcf_proto_ops *t, **tp;
68 write_lock(&cls_mod_lock);
69 for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
70 if (!strcmp(ops->kind, t->kind))
77 write_unlock(&cls_mod_lock);
80 EXPORT_SYMBOL(register_tcf_proto_ops);
82 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
84 struct tcf_proto_ops *t, **tp;
87 write_lock(&cls_mod_lock);
88 for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
97 write_unlock(&cls_mod_lock);
100 EXPORT_SYMBOL(unregister_tcf_proto_ops);
102 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
103 struct nlmsghdr *n, struct tcf_proto *tp,
104 unsigned long fh, int event);
107 /* Select new prio value from the range, managed by kernel. */
109 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
111 u32 first = TC_H_MAKE(0xC0000000U, 0U);
114 first = tp->prio - 1;
119 /* Add/change/delete/get a filter node */
121 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
123 struct net *net = sock_net(skb->sk);
124 struct nlattr *tca[TCA_MAX + 1];
125 spinlock_t *root_lock;
131 struct net_device *dev;
133 struct tcf_proto **back, **chain;
134 struct tcf_proto *tp;
135 const struct tcf_proto_ops *tp_ops;
136 const struct Qdisc_class_ops *cops;
144 protocol = TC_H_MIN(t->tcm_info);
145 prio = TC_H_MAJ(t->tcm_info);
147 parent = t->tcm_parent;
151 /* If no priority is given, user wants we allocated it. */
152 if (n->nlmsg_type != RTM_NEWTFILTER ||
153 !(n->nlmsg_flags & NLM_F_CREATE))
155 prio = TC_H_MAKE(0x80000000U, 0U);
158 /* Find head of filter chain. */
161 dev = __dev_get_by_index(net, t->tcm_ifindex);
165 err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL);
174 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
179 /* Is it classful? */
180 cops = q->ops->cl_ops;
184 if (cops->tcf_chain == NULL)
187 /* Do we search for filter, attached to class? */
188 if (TC_H_MIN(parent)) {
189 cl = cops->get(q, parent);
194 /* And the last stroke */
195 chain = cops->tcf_chain(q, cl);
200 /* Check the chain for existence of proto-tcf with this priority */
201 for (back = chain; (tp = *back) != NULL; back = &tp->next) {
202 if (tp->prio >= prio) {
203 if (tp->prio == prio) {
205 (tp->protocol != protocol && protocol))
213 root_lock = qdisc_root_sleeping_lock(q);
216 /* Proto-tcf does not exist, create new one */
218 if (tca[TCA_KIND] == NULL || !protocol)
222 if (n->nlmsg_type != RTM_NEWTFILTER ||
223 !(n->nlmsg_flags & NLM_F_CREATE))
227 /* Create new proto tcf */
230 tp = kzalloc(sizeof(*tp), GFP_KERNEL);
234 tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]);
235 if (tp_ops == NULL) {
236 #ifdef CONFIG_MODULES
237 struct nlattr *kind = tca[TCA_KIND];
241 nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
243 request_module("cls_%s", name);
245 tp_ops = tcf_proto_lookup_ops(kind);
246 /* We dropped the RTNL semaphore in order to
247 * perform the module load. So, even if we
248 * succeeded in loading the module we have to
249 * replay the request. We indicate this using
252 if (tp_ops != NULL) {
253 module_put(tp_ops->owner);
262 tp->protocol = protocol;
263 tp->prio = nprio ? : TC_H_MAJ(tcf_auto_prio(*back));
265 tp->classify = tp_ops->classify;
266 tp->classid = parent;
268 err = tp_ops->init(tp);
270 module_put(tp_ops->owner);
277 } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind))
280 fh = tp->ops->get(tp, t->tcm_handle);
283 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
284 spin_lock_bh(root_lock);
286 spin_unlock_bh(root_lock);
288 tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER);
295 if (n->nlmsg_type != RTM_NEWTFILTER ||
296 !(n->nlmsg_flags & NLM_F_CREATE))
299 switch (n->nlmsg_type) {
302 if (n->nlmsg_flags & NLM_F_EXCL) {
309 err = tp->ops->delete(tp, fh);
311 tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER);
314 err = tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER);
322 err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
325 spin_lock_bh(root_lock);
328 spin_unlock_bh(root_lock);
330 tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER);
340 /* Replay the request. */
345 static int tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp,
346 unsigned long fh, u32 pid, u32 seq, u16 flags, int event)
349 struct nlmsghdr *nlh;
350 unsigned char *b = skb_tail_pointer(skb);
352 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
353 tcm = NLMSG_DATA(nlh);
354 tcm->tcm_family = AF_UNSPEC;
357 tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex;
358 tcm->tcm_parent = tp->classid;
359 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
360 NLA_PUT_STRING(skb, TCA_KIND, tp->ops->kind);
361 tcm->tcm_handle = fh;
362 if (RTM_DELTFILTER != event) {
364 if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
365 goto nla_put_failure;
367 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
376 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
377 struct nlmsghdr *n, struct tcf_proto *tp,
378 unsigned long fh, int event)
381 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
383 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
387 if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
392 return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
393 n->nlmsg_flags & NLM_F_ECHO);
396 struct tcf_dump_args {
399 struct netlink_callback *cb;
402 static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
403 struct tcf_walker *arg)
405 struct tcf_dump_args *a = (void *)arg;
407 return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
408 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
411 /* called with RTNL */
412 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
414 struct net *net = sock_net(skb->sk);
417 struct net_device *dev;
419 struct tcf_proto *tp, **chain;
420 struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
421 unsigned long cl = 0;
422 const struct Qdisc_class_ops *cops;
423 struct tcf_dump_args arg;
425 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
427 dev = __dev_get_by_index(net, tcm->tcm_ifindex);
431 if (!tcm->tcm_parent)
434 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
437 cops = q->ops->cl_ops;
440 if (cops->tcf_chain == NULL)
442 if (TC_H_MIN(tcm->tcm_parent)) {
443 cl = cops->get(q, tcm->tcm_parent);
447 chain = cops->tcf_chain(q, cl);
453 for (tp = *chain, t = 0; tp; tp = tp->next, t++) {
456 if (TC_H_MAJ(tcm->tcm_info) &&
457 TC_H_MAJ(tcm->tcm_info) != tp->prio)
459 if (TC_H_MIN(tcm->tcm_info) &&
460 TC_H_MIN(tcm->tcm_info) != tp->protocol)
463 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
464 if (cb->args[1] == 0) {
465 if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
466 cb->nlh->nlmsg_seq, NLM_F_MULTI,
467 RTM_NEWTFILTER) <= 0)
472 if (tp->ops->walk == NULL)
474 arg.w.fn = tcf_node_dump;
478 arg.w.skip = cb->args[1] - 1;
480 tp->ops->walk(tp, &arg.w);
481 cb->args[1] = arg.w.count + 1;
495 void tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts)
497 #ifdef CONFIG_NET_CLS_ACT
499 tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
504 EXPORT_SYMBOL(tcf_exts_destroy);
506 int tcf_exts_validate(struct tcf_proto *tp, struct nlattr **tb,
507 struct nlattr *rate_tlv, struct tcf_exts *exts,
508 const struct tcf_ext_map *map)
510 memset(exts, 0, sizeof(*exts));
512 #ifdef CONFIG_NET_CLS_ACT
514 struct tc_action *act;
516 if (map->police && tb[map->police]) {
517 act = tcf_action_init_1(tb[map->police], rate_tlv,
518 "police", TCA_ACT_NOREPLACE,
523 act->type = TCA_OLD_COMPAT;
525 } else if (map->action && tb[map->action]) {
526 act = tcf_action_init(tb[map->action], rate_tlv, NULL,
527 TCA_ACT_NOREPLACE, TCA_ACT_BIND);
535 if ((map->action && tb[map->action]) ||
536 (map->police && tb[map->police]))
542 EXPORT_SYMBOL(tcf_exts_validate);
544 void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
545 struct tcf_exts *src)
547 #ifdef CONFIG_NET_CLS_ACT
549 struct tc_action *act;
552 dst->action = src->action;
555 tcf_action_destroy(act, TCA_ACT_UNBIND);
559 EXPORT_SYMBOL(tcf_exts_change);
561 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts,
562 const struct tcf_ext_map *map)
564 #ifdef CONFIG_NET_CLS_ACT
565 if (map->action && exts->action) {
567 * again for backward compatible mode - we want
568 * to work with both old and new modes of entering
569 * tc data even if iproute2 was newer - jhs
573 if (exts->action->type != TCA_OLD_COMPAT) {
574 nest = nla_nest_start(skb, map->action);
576 goto nla_put_failure;
577 if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
578 goto nla_put_failure;
579 nla_nest_end(skb, nest);
580 } else if (map->police) {
581 nest = nla_nest_start(skb, map->police);
583 goto nla_put_failure;
584 if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
585 goto nla_put_failure;
586 nla_nest_end(skb, nest);
591 nla_put_failure: __attribute__ ((unused))
594 EXPORT_SYMBOL(tcf_exts_dump);
597 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts,
598 const struct tcf_ext_map *map)
600 #ifdef CONFIG_NET_CLS_ACT
602 if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
603 goto nla_put_failure;
606 nla_put_failure: __attribute__ ((unused))
609 EXPORT_SYMBOL(tcf_exts_dump_stats);
611 static int __init tc_filter_init(void)
613 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, NULL);
614 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, NULL);
615 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
616 tc_dump_tfilter, NULL);
621 subsys_initcall(tc_filter_init);