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);
35 static void tcf_mirred_release(struct tc_action *a, int bind)
37 struct tcf_mirred *m = to_mirred(a);
38 struct net_device *dev = rcu_dereference_protected(m->tcfm_dev, 1);
40 list_del(&m->tcfm_list);
45 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
46 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
49 static int tcf_mirred_init(struct net *net, struct nlattr *nla,
50 struct nlattr *est, struct tc_action *a, int ovr,
53 struct nlattr *tb[TCA_MIRRED_MAX + 1];
54 struct tc_mirred *parm;
56 struct net_device *dev;
61 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
64 if (tb[TCA_MIRRED_PARMS] == NULL)
66 parm = nla_data(tb[TCA_MIRRED_PARMS]);
67 switch (parm->eaction) {
68 case TCA_EGRESS_MIRROR:
69 case TCA_EGRESS_REDIR:
75 dev = __dev_get_by_index(net, parm->ifindex);
95 if (!tcf_hash_check(parm->index, a, bind)) {
98 ret = tcf_hash_create(parm->index, est, a, sizeof(*m),
107 tcf_hash_release(a, bind);
114 m->tcf_action = parm->action;
115 m->tcfm_eaction = parm->eaction;
117 m->tcfm_ifindex = parm->ifindex;
118 if (ret != ACT_P_CREATED)
119 dev_put(rcu_dereference_protected(m->tcfm_dev, 1));
121 rcu_assign_pointer(m->tcfm_dev, dev);
122 m->tcfm_ok_push = ok_push;
125 if (ret == ACT_P_CREATED) {
126 list_add(&m->tcfm_list, &mirred_list);
133 static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
134 struct tcf_result *res)
136 struct tcf_mirred *m = a->priv;
137 struct net_device *dev;
138 struct sk_buff *skb2;
142 tcf_lastuse_update(&m->tcf_tm);
144 bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
147 retval = READ_ONCE(m->tcf_action);
148 dev = rcu_dereference(m->tcfm_dev);
149 if (unlikely(!dev)) {
150 pr_notice_once("tc mirred: target device is gone\n");
154 if (unlikely(!(dev->flags & IFF_UP))) {
155 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
160 at = G_TC_AT(skb->tc_verd);
161 skb2 = skb_clone(skb, GFP_ATOMIC);
165 if (!(at & AT_EGRESS)) {
167 skb_push(skb2, skb->mac_len);
170 /* mirror is always swallowed */
171 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
172 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
174 skb2->skb_iif = skb->dev->ifindex;
176 err = dev_queue_xmit(skb2);
180 qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
181 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
182 retval = TC_ACT_SHOT;
189 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
191 unsigned char *b = skb_tail_pointer(skb);
192 struct tcf_mirred *m = a->priv;
193 struct tc_mirred opt = {
194 .index = m->tcf_index,
195 .action = m->tcf_action,
196 .refcnt = m->tcf_refcnt - ref,
197 .bindcnt = m->tcf_bindcnt - bind,
198 .eaction = m->tcfm_eaction,
199 .ifindex = m->tcfm_ifindex,
203 if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
204 goto nla_put_failure;
205 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
206 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
207 t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
208 if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
209 goto nla_put_failure;
217 static int mirred_device_event(struct notifier_block *unused,
218 unsigned long event, void *ptr)
220 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
221 struct tcf_mirred *m;
224 if (event == NETDEV_UNREGISTER)
225 list_for_each_entry(m, &mirred_list, tcfm_list) {
226 if (rcu_access_pointer(m->tcfm_dev) == dev) {
228 /* Note : no rcu grace period necessary, as
229 * net_device are already rcu protected.
231 RCU_INIT_POINTER(m->tcfm_dev, NULL);
238 static struct notifier_block mirred_device_notifier = {
239 .notifier_call = mirred_device_event,
242 static struct tc_action_ops act_mirred_ops = {
244 .type = TCA_ACT_MIRRED,
245 .owner = THIS_MODULE,
247 .dump = tcf_mirred_dump,
248 .cleanup = tcf_mirred_release,
249 .init = tcf_mirred_init,
252 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
253 MODULE_DESCRIPTION("Device Mirror/redirect actions");
254 MODULE_LICENSE("GPL");
256 static int __init mirred_init_module(void)
258 int err = register_netdevice_notifier(&mirred_device_notifier);
262 pr_info("Mirror/redirect action on\n");
263 return tcf_register_action(&act_mirred_ops, MIRRED_TAB_MASK);
266 static void __exit mirred_cleanup_module(void)
268 tcf_unregister_action(&act_mirred_ops);
269 unregister_netdevice_notifier(&mirred_device_notifier);
272 module_init(mirred_init_module);
273 module_exit(mirred_cleanup_module);