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 = rcu_dereference_protected(m->tcfm_dev, 1);
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 spin_unlock_bh(&mirred_list_lock);
49 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
50 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
53 static int mirred_net_id;
55 static int tcf_mirred_init(struct net *net, struct nlattr *nla,
56 struct nlattr *est, struct tc_action *a, int ovr,
59 struct tc_action_net *tn = net_generic(net, mirred_net_id);
60 struct nlattr *tb[TCA_MIRRED_MAX + 1];
61 struct tc_mirred *parm;
63 struct net_device *dev;
64 int ret, ok_push = 0, exists = 0;
68 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
71 if (tb[TCA_MIRRED_PARMS] == NULL)
73 parm = nla_data(tb[TCA_MIRRED_PARMS]);
75 exists = tcf_hash_check(tn, parm->index, a, bind);
79 switch (parm->eaction) {
80 case TCA_EGRESS_MIRROR:
81 case TCA_EGRESS_REDIR:
85 tcf_hash_release(a, bind);
89 dev = __dev_get_by_index(net, parm->ifindex);
92 tcf_hash_release(a, bind);
115 ret = tcf_hash_create(tn, parm->index, est, a,
116 sizeof(*m), bind, true);
121 tcf_hash_release(a, bind);
128 m->tcf_action = parm->action;
129 m->tcfm_eaction = parm->eaction;
131 m->tcfm_ifindex = parm->ifindex;
132 if (ret != ACT_P_CREATED)
133 dev_put(rcu_dereference_protected(m->tcfm_dev, 1));
135 rcu_assign_pointer(m->tcfm_dev, dev);
136 m->tcfm_ok_push = ok_push;
139 if (ret == ACT_P_CREATED) {
140 spin_lock_bh(&mirred_list_lock);
141 list_add(&m->tcfm_list, &mirred_list);
142 spin_unlock_bh(&mirred_list_lock);
143 tcf_hash_insert(tn, a);
149 static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
150 struct tcf_result *res)
152 struct tcf_mirred *m = a->priv;
153 struct net_device *dev;
154 struct sk_buff *skb2;
158 tcf_lastuse_update(&m->tcf_tm);
160 bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
163 retval = READ_ONCE(m->tcf_action);
164 dev = rcu_dereference(m->tcfm_dev);
165 if (unlikely(!dev)) {
166 pr_notice_once("tc mirred: target device is gone\n");
170 if (unlikely(!(dev->flags & IFF_UP))) {
171 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
176 at = G_TC_AT(skb->tc_verd);
177 skb2 = skb_clone(skb, GFP_ATOMIC);
181 if (!(at & AT_EGRESS)) {
183 skb_push(skb2, skb->mac_len);
186 /* mirror is always swallowed */
187 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
188 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
190 skb2->skb_iif = skb->dev->ifindex;
192 err = dev_queue_xmit(skb2);
196 qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
197 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
198 retval = TC_ACT_SHOT;
205 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
207 unsigned char *b = skb_tail_pointer(skb);
208 struct tcf_mirred *m = a->priv;
209 struct tc_mirred opt = {
210 .index = m->tcf_index,
211 .action = m->tcf_action,
212 .refcnt = m->tcf_refcnt - ref,
213 .bindcnt = m->tcf_bindcnt - bind,
214 .eaction = m->tcfm_eaction,
215 .ifindex = m->tcfm_ifindex,
219 if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
220 goto nla_put_failure;
221 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
222 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
223 t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
224 if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
225 goto nla_put_failure;
233 static int tcf_mirred_walker(struct net *net, struct sk_buff *skb,
234 struct netlink_callback *cb, int type,
237 struct tc_action_net *tn = net_generic(net, mirred_net_id);
239 return tcf_generic_walker(tn, skb, cb, type, a);
242 static int tcf_mirred_search(struct net *net, struct tc_action *a, u32 index)
244 struct tc_action_net *tn = net_generic(net, mirred_net_id);
246 return tcf_hash_search(tn, a, index);
249 static int mirred_device_event(struct notifier_block *unused,
250 unsigned long event, void *ptr)
252 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
253 struct tcf_mirred *m;
256 if (event == NETDEV_UNREGISTER) {
257 spin_lock_bh(&mirred_list_lock);
258 list_for_each_entry(m, &mirred_list, tcfm_list) {
259 if (rcu_access_pointer(m->tcfm_dev) == dev) {
261 /* Note : no rcu grace period necessary, as
262 * net_device are already rcu protected.
264 RCU_INIT_POINTER(m->tcfm_dev, NULL);
267 spin_unlock_bh(&mirred_list_lock);
273 static struct notifier_block mirred_device_notifier = {
274 .notifier_call = mirred_device_event,
277 static struct tc_action_ops act_mirred_ops = {
279 .type = TCA_ACT_MIRRED,
280 .owner = THIS_MODULE,
282 .dump = tcf_mirred_dump,
283 .cleanup = tcf_mirred_release,
284 .init = tcf_mirred_init,
285 .walk = tcf_mirred_walker,
286 .lookup = tcf_mirred_search,
289 static __net_init int mirred_init_net(struct net *net)
291 struct tc_action_net *tn = net_generic(net, mirred_net_id);
293 return tc_action_net_init(tn, &act_mirred_ops, MIRRED_TAB_MASK);
296 static void __net_exit mirred_exit_net(struct net *net)
298 struct tc_action_net *tn = net_generic(net, mirred_net_id);
300 tc_action_net_exit(tn);
303 static struct pernet_operations mirred_net_ops = {
304 .init = mirred_init_net,
305 .exit = mirred_exit_net,
306 .id = &mirred_net_id,
307 .size = sizeof(struct tc_action_net),
310 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
311 MODULE_DESCRIPTION("Device Mirror/redirect actions");
312 MODULE_LICENSE("GPL");
314 static int __init mirred_init_module(void)
316 int err = register_netdevice_notifier(&mirred_device_notifier);
320 pr_info("Mirror/redirect action on\n");
321 return tcf_register_action(&act_mirred_ops, &mirred_net_ops);
324 static void __exit mirred_cleanup_module(void)
326 tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
327 unregister_netdevice_notifier(&mirred_device_notifier);
330 module_init(mirred_init_module);
331 module_exit(mirred_cleanup_module);