2 * net/sched/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 struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
34 static u32 mirred_idx_gen;
35 static DEFINE_RWLOCK(mirred_lock);
36 static LIST_HEAD(mirred_list);
38 static struct tcf_hashinfo mirred_hash_info = {
39 .htab = tcf_mirred_ht,
40 .hmask = MIRRED_TAB_MASK,
44 static int tcf_mirred_release(struct tcf_mirred *m, int bind)
50 if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
51 list_del(&m->tcfm_list);
54 tcf_hash_destroy(&m->common, &mirred_hash_info);
61 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
62 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
65 static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
66 struct tc_action *a, int ovr, int bind)
68 struct nlattr *tb[TCA_MIRRED_MAX + 1];
69 struct tc_mirred *parm;
71 struct tcf_common *pc;
72 struct net_device *dev;
77 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
80 if (tb[TCA_MIRRED_PARMS] == NULL)
82 parm = nla_data(tb[TCA_MIRRED_PARMS]);
83 switch (parm->eaction) {
84 case TCA_EGRESS_MIRROR:
85 case TCA_EGRESS_REDIR:
91 dev = __dev_get_by_index(&init_net, parm->ifindex);
111 pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
115 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
116 &mirred_idx_gen, &mirred_hash_info);
122 tcf_mirred_release(to_mirred(pc), bind);
128 spin_lock_bh(&m->tcf_lock);
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(m->tcfm_dev);
137 m->tcfm_ok_push = ok_push;
139 spin_unlock_bh(&m->tcf_lock);
140 if (ret == ACT_P_CREATED) {
141 list_add(&m->tcfm_list, &mirred_list);
142 tcf_hash_insert(pc, &mirred_hash_info);
148 static int tcf_mirred_cleanup(struct tc_action *a, int bind)
150 struct tcf_mirred *m = a->priv;
153 return tcf_mirred_release(m, bind);
157 static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
158 struct tcf_result *res)
160 struct tcf_mirred *m = a->priv;
161 struct net_device *dev;
162 struct sk_buff *skb2;
166 spin_lock(&m->tcf_lock);
167 m->tcf_tm.lastuse = jiffies;
168 bstats_update(&m->tcf_bstats, skb);
172 printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
176 if (!(dev->flags & IFF_UP)) {
178 pr_notice("tc mirred to Houston: device %s is down\n",
183 at = G_TC_AT(skb->tc_verd);
184 skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
188 if (!(at & AT_EGRESS)) {
190 skb_push(skb2, skb2->dev->hard_header_len);
193 /* mirror is always swallowed */
194 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
195 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
197 skb2->skb_iif = skb->dev->ifindex;
199 err = dev_queue_xmit(skb2);
203 m->tcf_qstats.overlimits++;
204 /* should we be asking for packet to be dropped?
205 * may make sense for redirect case only
207 retval = TC_ACT_SHOT;
209 retval = m->tcf_action;
211 spin_unlock(&m->tcf_lock);
216 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
218 unsigned char *b = skb_tail_pointer(skb);
219 struct tcf_mirred *m = a->priv;
220 struct tc_mirred opt = {
221 .index = m->tcf_index,
222 .action = m->tcf_action,
223 .refcnt = m->tcf_refcnt - ref,
224 .bindcnt = m->tcf_bindcnt - bind,
225 .eaction = m->tcfm_eaction,
226 .ifindex = m->tcfm_ifindex,
230 NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
231 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
232 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
233 t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
234 NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
242 static int mirred_device_event(struct notifier_block *unused,
243 unsigned long event, void *ptr)
245 struct net_device *dev = ptr;
246 struct tcf_mirred *m;
248 if (event == NETDEV_UNREGISTER)
249 list_for_each_entry(m, &mirred_list, tcfm_list) {
250 if (m->tcfm_dev == dev) {
259 static struct notifier_block mirred_device_notifier = {
260 .notifier_call = mirred_device_event,
264 static struct tc_action_ops act_mirred_ops = {
266 .hinfo = &mirred_hash_info,
267 .type = TCA_ACT_MIRRED,
268 .capab = TCA_CAP_NONE,
269 .owner = THIS_MODULE,
271 .dump = tcf_mirred_dump,
272 .cleanup = tcf_mirred_cleanup,
273 .lookup = tcf_hash_search,
274 .init = tcf_mirred_init,
275 .walk = tcf_generic_walker
278 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
279 MODULE_DESCRIPTION("Device Mirror/redirect actions");
280 MODULE_LICENSE("GPL");
282 static int __init mirred_init_module(void)
284 int err = register_netdevice_notifier(&mirred_device_notifier);
288 pr_info("Mirror/redirect action on\n");
289 return tcf_register_action(&act_mirred_ops);
292 static void __exit mirred_cleanup_module(void)
294 unregister_netdevice_notifier(&mirred_device_notifier);
295 tcf_unregister_action(&act_mirred_ops);
298 module_init(mirred_init_module);
299 module_exit(mirred_cleanup_module);