2 * net/sched/act_mirred.c packet mirroring and redirect actions
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: Jamal Hadi Salim (2002-4)
11 * TODO: Add ingress support (and socket redirect support)
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/skbuff.h>
20 #include <linux/rtnetlink.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/gfp.h>
24 #include <net/net_namespace.h>
25 #include <net/netlink.h>
26 #include <net/pkt_sched.h>
27 #include <linux/tc_act/tc_mirred.h>
28 #include <net/tc_act/tc_mirred.h>
30 #include <linux/if_arp.h>
32 #define MIRRED_TAB_MASK 7
33 static LIST_HEAD(mirred_list);
34 static DEFINE_SPINLOCK(mirred_list_lock);
36 static void tcf_mirred_release(struct tc_action *a, int bind)
38 struct tcf_mirred *m = to_mirred(a);
39 struct net_device *dev;
41 /* We could be called either in a RCU callback or with RTNL lock held. */
42 spin_lock_bh(&mirred_list_lock);
43 list_del(&m->tcfm_list);
44 dev = rcu_dereference_protected(m->tcfm_dev, 1);
47 spin_unlock_bh(&mirred_list_lock);
50 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
51 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
54 static int mirred_net_id;
56 static int tcf_mirred_init(struct net *net, struct nlattr *nla,
57 struct nlattr *est, struct tc_action *a, int ovr,
60 struct tc_action_net *tn = net_generic(net, mirred_net_id);
61 struct nlattr *tb[TCA_MIRRED_MAX + 1];
62 struct tc_mirred *parm;
64 struct net_device *dev;
65 int ret, ok_push = 0, exists = 0;
69 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
72 if (tb[TCA_MIRRED_PARMS] == NULL)
74 parm = nla_data(tb[TCA_MIRRED_PARMS]);
76 exists = tcf_hash_check(tn, parm->index, a, bind);
80 switch (parm->eaction) {
81 case TCA_EGRESS_MIRROR:
82 case TCA_EGRESS_REDIR:
86 tcf_hash_release(a, bind);
90 dev = __dev_get_by_index(net, parm->ifindex);
93 tcf_hash_release(a, bind);
116 ret = tcf_hash_create(tn, parm->index, est, a,
117 sizeof(*m), bind, true);
122 tcf_hash_release(a, bind);
129 m->tcf_action = parm->action;
130 m->tcfm_eaction = parm->eaction;
132 m->tcfm_ifindex = parm->ifindex;
133 if (ret != ACT_P_CREATED)
134 dev_put(rcu_dereference_protected(m->tcfm_dev, 1));
136 rcu_assign_pointer(m->tcfm_dev, dev);
137 m->tcfm_ok_push = ok_push;
140 if (ret == ACT_P_CREATED) {
141 spin_lock_bh(&mirred_list_lock);
142 list_add(&m->tcfm_list, &mirred_list);
143 spin_unlock_bh(&mirred_list_lock);
144 tcf_hash_insert(tn, a);
150 static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
151 struct tcf_result *res)
153 struct tcf_mirred *m = a->priv;
154 struct net_device *dev;
155 struct sk_buff *skb2;
159 tcf_lastuse_update(&m->tcf_tm);
161 bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
164 retval = READ_ONCE(m->tcf_action);
165 dev = rcu_dereference(m->tcfm_dev);
166 if (unlikely(!dev)) {
167 pr_notice_once("tc mirred: target device is gone\n");
171 if (unlikely(!(dev->flags & IFF_UP))) {
172 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
177 at = G_TC_AT(skb->tc_verd);
178 skb2 = skb_clone(skb, GFP_ATOMIC);
182 if (!(at & AT_EGRESS)) {
184 skb_push_rcsum(skb2, skb->mac_len);
187 /* mirror is always swallowed */
188 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
189 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
191 skb2->skb_iif = skb->dev->ifindex;
193 err = dev_queue_xmit(skb2);
197 qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
198 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
199 retval = TC_ACT_SHOT;
206 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
208 unsigned char *b = skb_tail_pointer(skb);
209 struct tcf_mirred *m = a->priv;
210 struct tc_mirred opt = {
211 .index = m->tcf_index,
212 .action = m->tcf_action,
213 .refcnt = m->tcf_refcnt - ref,
214 .bindcnt = m->tcf_bindcnt - bind,
215 .eaction = m->tcfm_eaction,
216 .ifindex = m->tcfm_ifindex,
220 if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
221 goto nla_put_failure;
222 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
223 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
224 t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
225 if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
226 goto nla_put_failure;
234 static int tcf_mirred_walker(struct net *net, struct sk_buff *skb,
235 struct netlink_callback *cb, int type,
238 struct tc_action_net *tn = net_generic(net, mirred_net_id);
240 return tcf_generic_walker(tn, skb, cb, type, a);
243 static int tcf_mirred_search(struct net *net, struct tc_action *a, u32 index)
245 struct tc_action_net *tn = net_generic(net, mirred_net_id);
247 return tcf_hash_search(tn, a, index);
250 static int mirred_device_event(struct notifier_block *unused,
251 unsigned long event, void *ptr)
253 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
254 struct tcf_mirred *m;
257 if (event == NETDEV_UNREGISTER) {
258 spin_lock_bh(&mirred_list_lock);
259 list_for_each_entry(m, &mirred_list, tcfm_list) {
260 if (rcu_access_pointer(m->tcfm_dev) == dev) {
262 /* Note : no rcu grace period necessary, as
263 * net_device are already rcu protected.
265 RCU_INIT_POINTER(m->tcfm_dev, NULL);
268 spin_unlock_bh(&mirred_list_lock);
274 static struct notifier_block mirred_device_notifier = {
275 .notifier_call = mirred_device_event,
278 static struct tc_action_ops act_mirred_ops = {
280 .type = TCA_ACT_MIRRED,
281 .owner = THIS_MODULE,
283 .dump = tcf_mirred_dump,
284 .cleanup = tcf_mirred_release,
285 .init = tcf_mirred_init,
286 .walk = tcf_mirred_walker,
287 .lookup = tcf_mirred_search,
290 static __net_init int mirred_init_net(struct net *net)
292 struct tc_action_net *tn = net_generic(net, mirred_net_id);
294 return tc_action_net_init(tn, &act_mirred_ops, MIRRED_TAB_MASK);
297 static void __net_exit mirred_exit_net(struct net *net)
299 struct tc_action_net *tn = net_generic(net, mirred_net_id);
301 tc_action_net_exit(tn);
304 static struct pernet_operations mirred_net_ops = {
305 .init = mirred_init_net,
306 .exit = mirred_exit_net,
307 .id = &mirred_net_id,
308 .size = sizeof(struct tc_action_net),
311 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
312 MODULE_DESCRIPTION("Device Mirror/redirect actions");
313 MODULE_LICENSE("GPL");
315 static int __init mirred_init_module(void)
317 int err = register_netdevice_notifier(&mirred_device_notifier);
321 pr_info("Mirror/redirect action on\n");
322 return tcf_register_action(&act_mirred_ops, &mirred_net_ops);
325 static void __exit mirred_cleanup_module(void)
327 tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
328 unregister_netdevice_notifier(&mirred_device_notifier);
331 module_init(mirred_init_module);
332 module_exit(mirred_cleanup_module);