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);
37 static struct tcf_hashinfo mirred_hash_info = {
38 .htab = tcf_mirred_ht,
39 .hmask = MIRRED_TAB_MASK,
43 static inline int tcf_mirred_release(struct tcf_mirred *m, int bind)
49 if(!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
51 tcf_hash_destroy(&m->common, &mirred_hash_info);
58 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
59 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
62 static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
63 struct tc_action *a, int ovr, int bind)
65 struct nlattr *tb[TCA_MIRRED_MAX + 1];
66 struct tc_mirred *parm;
68 struct tcf_common *pc;
69 struct net_device *dev;
74 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
77 if (tb[TCA_MIRRED_PARMS] == NULL)
79 parm = nla_data(tb[TCA_MIRRED_PARMS]);
80 switch (parm->eaction) {
81 case TCA_EGRESS_MIRROR:
82 case TCA_EGRESS_REDIR:
88 dev = __dev_get_by_index(&init_net, parm->ifindex);
108 pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
112 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
113 &mirred_idx_gen, &mirred_hash_info);
119 tcf_mirred_release(to_mirred(pc), bind);
125 spin_lock_bh(&m->tcf_lock);
126 m->tcf_action = parm->action;
127 m->tcfm_eaction = parm->eaction;
129 m->tcfm_ifindex = parm->ifindex;
130 if (ret != ACT_P_CREATED)
131 dev_put(m->tcfm_dev);
134 m->tcfm_ok_push = ok_push;
136 spin_unlock_bh(&m->tcf_lock);
137 if (ret == ACT_P_CREATED)
138 tcf_hash_insert(pc, &mirred_hash_info);
143 static int tcf_mirred_cleanup(struct tc_action *a, int bind)
145 struct tcf_mirred *m = a->priv;
148 return tcf_mirred_release(m, bind);
152 static int tcf_mirred(struct sk_buff *skb, struct tc_action *a,
153 struct tcf_result *res)
155 struct tcf_mirred *m = a->priv;
156 struct net_device *dev;
157 struct sk_buff *skb2;
161 spin_lock(&m->tcf_lock);
162 m->tcf_tm.lastuse = jiffies;
165 if (!(dev->flags & IFF_UP)) {
167 pr_notice("tc mirred to Houston: device %s is gone!\n",
172 skb2 = skb_act_clone(skb, GFP_ATOMIC);
176 m->tcf_bstats.bytes += qdisc_pkt_len(skb2);
177 m->tcf_bstats.packets++;
178 at = G_TC_AT(skb->tc_verd);
179 if (!(at & AT_EGRESS)) {
181 skb_push(skb2, skb2->dev->hard_header_len);
184 /* mirror is always swallowed */
185 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
186 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
189 skb2->skb_iif = skb->dev->ifindex;
190 dev_queue_xmit(skb2);
195 m->tcf_qstats.overlimits++;
196 m->tcf_bstats.bytes += qdisc_pkt_len(skb);
197 m->tcf_bstats.packets++;
198 /* should we be asking for packet to be dropped?
199 * may make sense for redirect case only
201 retval = TC_ACT_SHOT;
203 retval = m->tcf_action;
205 spin_unlock(&m->tcf_lock);
210 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
212 unsigned char *b = skb_tail_pointer(skb);
213 struct tcf_mirred *m = a->priv;
214 struct tc_mirred opt;
217 opt.index = m->tcf_index;
218 opt.action = m->tcf_action;
219 opt.refcnt = m->tcf_refcnt - ref;
220 opt.bindcnt = m->tcf_bindcnt - bind;
221 opt.eaction = m->tcfm_eaction;
222 opt.ifindex = m->tcfm_ifindex;
223 NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
224 t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
225 t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
226 t.expires = jiffies_to_clock_t(m->tcf_tm.expires);
227 NLA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
235 static struct tc_action_ops act_mirred_ops = {
237 .hinfo = &mirred_hash_info,
238 .type = TCA_ACT_MIRRED,
239 .capab = TCA_CAP_NONE,
240 .owner = THIS_MODULE,
242 .dump = tcf_mirred_dump,
243 .cleanup = tcf_mirred_cleanup,
244 .lookup = tcf_hash_search,
245 .init = tcf_mirred_init,
246 .walk = tcf_generic_walker
249 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
250 MODULE_DESCRIPTION("Device Mirror/redirect actions");
251 MODULE_LICENSE("GPL");
253 static int __init mirred_init_module(void)
255 pr_info("Mirror/redirect action on\n");
256 return tcf_register_action(&act_mirred_ops);
259 static void __exit mirred_cleanup_module(void)
261 tcf_unregister_action(&act_mirred_ops);
264 module_init(mirred_init_module);
265 module_exit(mirred_cleanup_module);