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
);