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1/*
2 * net/sched/mirred.c packet mirroring and redirect actions
3 *
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.
8 *
9 * Authors: Jamal Hadi Salim (2002-4)
10 *
11 * TODO: Add ingress support (and socket redirect support)
12 *
13 */
14
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>
29
30#include <linux/if_arp.h>
31
32#define MIRRED_TAB_MASK 7
33static struct tcf_common *tcf_mirred_ht[MIRRED_TAB_MASK + 1];
34static u32 mirred_idx_gen;
35static DEFINE_RWLOCK(mirred_lock);
36static LIST_HEAD(mirred_list);
37
38static struct tcf_hashinfo mirred_hash_info = {
39 .htab = tcf_mirred_ht,
40 .hmask = MIRRED_TAB_MASK,
41 .lock = &mirred_lock,
42};
43
44static int tcf_mirred_release(struct tcf_mirred *m, int bind)
45{
46 if (m) {
47 if (bind)
48 m->tcf_bindcnt--;
49 m->tcf_refcnt--;
50 if (!m->tcf_bindcnt && m->tcf_refcnt <= 0) {
51 list_del(&m->tcfm_list);
52 if (m->tcfm_dev)
53 dev_put(m->tcfm_dev);
54 tcf_hash_destroy(&m->common, &mirred_hash_info);
55 return 1;
56 }
57 }
58 return 0;
59}
60
61static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
62 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
63};
64
65static int tcf_mirred_init(struct nlattr *nla, struct nlattr *est,
66 struct tc_action *a, int ovr, int bind)
67{
68 struct nlattr *tb[TCA_MIRRED_MAX + 1];
69 struct tc_mirred *parm;
70 struct tcf_mirred *m;
71 struct tcf_common *pc;
72 struct net_device *dev;
73 int ret, ok_push = 0;
74
75 if (nla == NULL)
76 return -EINVAL;
77 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
78 if (ret < 0)
79 return ret;
80 if (tb[TCA_MIRRED_PARMS] == NULL)
81 return -EINVAL;
82 parm = nla_data(tb[TCA_MIRRED_PARMS]);
83 switch (parm->eaction) {
84 case TCA_EGRESS_MIRROR:
85 case TCA_EGRESS_REDIR:
86 break;
87 default:
88 return -EINVAL;
89 }
90 if (parm->ifindex) {
91 dev = __dev_get_by_index(&init_net, parm->ifindex);
92 if (dev == NULL)
93 return -ENODEV;
94 switch (dev->type) {
95 case ARPHRD_TUNNEL:
96 case ARPHRD_TUNNEL6:
97 case ARPHRD_SIT:
98 case ARPHRD_IPGRE:
99 case ARPHRD_VOID:
100 case ARPHRD_NONE:
101 ok_push = 0;
102 break;
103 default:
104 ok_push = 1;
105 break;
106 }
107 } else {
108 dev = NULL;
109 }
110
111 pc = tcf_hash_check(parm->index, a, bind, &mirred_hash_info);
112 if (!pc) {
113 if (dev == NULL)
114 return -EINVAL;
115 pc = tcf_hash_create(parm->index, est, a, sizeof(*m), bind,
116 &mirred_idx_gen, &mirred_hash_info);
117 if (IS_ERR(pc))
118 return PTR_ERR(pc);
119 ret = ACT_P_CREATED;
120 } else {
121 if (!ovr) {
122 tcf_mirred_release(to_mirred(pc), bind);
123 return -EEXIST;
124 }
125 }
126 m = to_mirred(pc);
127
128 spin_lock_bh(&m->tcf_lock);
129 m->tcf_action = parm->action;
130 m->tcfm_eaction = parm->eaction;
131 if (dev != NULL) {
132 m->tcfm_ifindex = parm->ifindex;
133 if (ret != ACT_P_CREATED)
134 dev_put(m->tcfm_dev);
135 dev_hold(dev);
136 m->tcfm_dev = dev;
137 m->tcfm_ok_push = ok_push;
138 }
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);
143 }
144
145 return ret;
146}
147
148static int tcf_mirred_cleanup(struct tc_action *a, int bind)
149{
150 struct tcf_mirred *m = a->priv;
151
152 if (m)
153 return tcf_mirred_release(m, bind);
154 return 0;
155}
156
157static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
158 struct tcf_result *res)
159{
160 struct tcf_mirred *m = a->priv;
161 struct net_device *dev;
162 struct sk_buff *skb2;
163 u32 at;
164 int retval, err = 1;
165
166 spin_lock(&m->tcf_lock);
167 m->tcf_tm.lastuse = jiffies;
168 bstats_update(&m->tcf_bstats, skb);
169
170 dev = m->tcfm_dev;
171 if (!dev) {
172 printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
173 goto out;
174 }
175
176 if (!(dev->flags & IFF_UP)) {
177 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
178 dev->name);
179 goto out;
180 }
181
182 at = G_TC_AT(skb->tc_verd);
183 skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
184 if (skb2 == NULL)
185 goto out;
186
187 if (!(at & AT_EGRESS)) {
188 if (m->tcfm_ok_push)
189 skb_push(skb2, skb2->dev->hard_header_len);
190 }
191
192 /* mirror is always swallowed */
193 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
194 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
195
196 skb2->skb_iif = skb->dev->ifindex;
197 skb2->dev = dev;
198 err = dev_queue_xmit(skb2);
199
200out:
201 if (err) {
202 m->tcf_qstats.overlimits++;
203 /* should we be asking for packet to be dropped?
204 * may make sense for redirect case only
205 */
206 retval = TC_ACT_SHOT;
207 } else {
208 retval = m->tcf_action;
209 }
210 spin_unlock(&m->tcf_lock);
211
212 return retval;
213}
214
215static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
216{
217 unsigned char *b = skb_tail_pointer(skb);
218 struct tcf_mirred *m = a->priv;
219 struct tc_mirred opt = {
220 .index = m->tcf_index,
221 .action = m->tcf_action,
222 .refcnt = m->tcf_refcnt - ref,
223 .bindcnt = m->tcf_bindcnt - bind,
224 .eaction = m->tcfm_eaction,
225 .ifindex = m->tcfm_ifindex,
226 };
227 struct tcf_t t;
228
229 if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
230 goto nla_put_failure;
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 if (nla_put(skb, TCA_MIRRED_TM, sizeof(t), &t))
235 goto nla_put_failure;
236 return skb->len;
237
238nla_put_failure:
239 nlmsg_trim(skb, b);
240 return -1;
241}
242
243static int mirred_device_event(struct notifier_block *unused,
244 unsigned long event, void *ptr)
245{
246 struct net_device *dev = ptr;
247 struct tcf_mirred *m;
248
249 if (event == NETDEV_UNREGISTER)
250 list_for_each_entry(m, &mirred_list, tcfm_list) {
251 if (m->tcfm_dev == dev) {
252 dev_put(dev);
253 m->tcfm_dev = NULL;
254 }
255 }
256
257 return NOTIFY_DONE;
258}
259
260static struct notifier_block mirred_device_notifier = {
261 .notifier_call = mirred_device_event,
262};
263
264
265static struct tc_action_ops act_mirred_ops = {
266 .kind = "mirred",
267 .hinfo = &mirred_hash_info,
268 .type = TCA_ACT_MIRRED,
269 .capab = TCA_CAP_NONE,
270 .owner = THIS_MODULE,
271 .act = tcf_mirred,
272 .dump = tcf_mirred_dump,
273 .cleanup = tcf_mirred_cleanup,
274 .lookup = tcf_hash_search,
275 .init = tcf_mirred_init,
276 .walk = tcf_generic_walker
277};
278
279MODULE_AUTHOR("Jamal Hadi Salim(2002)");
280MODULE_DESCRIPTION("Device Mirror/redirect actions");
281MODULE_LICENSE("GPL");
282
283static int __init mirred_init_module(void)
284{
285 int err = register_netdevice_notifier(&mirred_device_notifier);
286 if (err)
287 return err;
288
289 pr_info("Mirror/redirect action on\n");
290 return tcf_register_action(&act_mirred_ops);
291}
292
293static void __exit mirred_cleanup_module(void)
294{
295 unregister_netdevice_notifier(&mirred_device_notifier);
296 tcf_unregister_action(&act_mirred_ops);
297}
298
299module_init(mirred_init_module);
300module_exit(mirred_cleanup_module);
1/*
2 * net/sched/act_mirred.c packet mirroring and redirect actions
3 *
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.
8 *
9 * Authors: Jamal Hadi Salim (2002-4)
10 *
11 * TODO: Add ingress support (and socket redirect support)
12 *
13 */
14
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>
29
30#include <linux/if_arp.h>
31
32#define MIRRED_TAB_MASK 7
33static LIST_HEAD(mirred_list);
34static DEFINE_SPINLOCK(mirred_list_lock);
35
36static void tcf_mirred_release(struct tc_action *a, int bind)
37{
38 struct tcf_mirred *m = to_mirred(a);
39 struct net_device *dev = rcu_dereference_protected(m->tcfm_dev, 1);
40
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);
45 if (dev)
46 dev_put(dev);
47}
48
49static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
50 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
51};
52
53static int mirred_net_id;
54
55static int tcf_mirred_init(struct net *net, struct nlattr *nla,
56 struct nlattr *est, struct tc_action *a, int ovr,
57 int bind)
58{
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;
62 struct tcf_mirred *m;
63 struct net_device *dev;
64 int ret, ok_push = 0, exists = 0;
65
66 if (nla == NULL)
67 return -EINVAL;
68 ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
69 if (ret < 0)
70 return ret;
71 if (tb[TCA_MIRRED_PARMS] == NULL)
72 return -EINVAL;
73 parm = nla_data(tb[TCA_MIRRED_PARMS]);
74
75 exists = tcf_hash_check(tn, parm->index, a, bind);
76 if (exists && bind)
77 return 0;
78
79 switch (parm->eaction) {
80 case TCA_EGRESS_MIRROR:
81 case TCA_EGRESS_REDIR:
82 break;
83 default:
84 if (exists)
85 tcf_hash_release(a, bind);
86 return -EINVAL;
87 }
88 if (parm->ifindex) {
89 dev = __dev_get_by_index(net, parm->ifindex);
90 if (dev == NULL) {
91 if (exists)
92 tcf_hash_release(a, bind);
93 return -ENODEV;
94 }
95 switch (dev->type) {
96 case ARPHRD_TUNNEL:
97 case ARPHRD_TUNNEL6:
98 case ARPHRD_SIT:
99 case ARPHRD_IPGRE:
100 case ARPHRD_VOID:
101 case ARPHRD_NONE:
102 ok_push = 0;
103 break;
104 default:
105 ok_push = 1;
106 break;
107 }
108 } else {
109 dev = NULL;
110 }
111
112 if (!exists) {
113 if (dev == NULL)
114 return -EINVAL;
115 ret = tcf_hash_create(tn, parm->index, est, a,
116 sizeof(*m), bind, true);
117 if (ret)
118 return ret;
119 ret = ACT_P_CREATED;
120 } else {
121 tcf_hash_release(a, bind);
122 if (!ovr)
123 return -EEXIST;
124 }
125 m = to_mirred(a);
126
127 ASSERT_RTNL();
128 m->tcf_action = parm->action;
129 m->tcfm_eaction = parm->eaction;
130 if (dev != NULL) {
131 m->tcfm_ifindex = parm->ifindex;
132 if (ret != ACT_P_CREATED)
133 dev_put(rcu_dereference_protected(m->tcfm_dev, 1));
134 dev_hold(dev);
135 rcu_assign_pointer(m->tcfm_dev, dev);
136 m->tcfm_ok_push = ok_push;
137 }
138
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);
144 }
145
146 return ret;
147}
148
149static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
150 struct tcf_result *res)
151{
152 struct tcf_mirred *m = a->priv;
153 struct net_device *dev;
154 struct sk_buff *skb2;
155 int retval, err;
156 u32 at;
157
158 tcf_lastuse_update(&m->tcf_tm);
159
160 bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
161
162 rcu_read_lock();
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");
167 goto out;
168 }
169
170 if (unlikely(!(dev->flags & IFF_UP))) {
171 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
172 dev->name);
173 goto out;
174 }
175
176 at = G_TC_AT(skb->tc_verd);
177 skb2 = skb_clone(skb, GFP_ATOMIC);
178 if (!skb2)
179 goto out;
180
181 if (!(at & AT_EGRESS)) {
182 if (m->tcfm_ok_push)
183 skb_push(skb2, skb->mac_len);
184 }
185
186 /* mirror is always swallowed */
187 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
188 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
189
190 skb2->skb_iif = skb->dev->ifindex;
191 skb2->dev = dev;
192 err = dev_queue_xmit(skb2);
193
194 if (err) {
195out:
196 qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
197 if (m->tcfm_eaction != TCA_EGRESS_MIRROR)
198 retval = TC_ACT_SHOT;
199 }
200 rcu_read_unlock();
201
202 return retval;
203}
204
205static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
206{
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,
216 };
217 struct tcf_t t;
218
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(skb, TCA_MIRRED_TM, sizeof(t), &t))
225 goto nla_put_failure;
226 return skb->len;
227
228nla_put_failure:
229 nlmsg_trim(skb, b);
230 return -1;
231}
232
233static int tcf_mirred_walker(struct net *net, struct sk_buff *skb,
234 struct netlink_callback *cb, int type,
235 struct tc_action *a)
236{
237 struct tc_action_net *tn = net_generic(net, mirred_net_id);
238
239 return tcf_generic_walker(tn, skb, cb, type, a);
240}
241
242static int tcf_mirred_search(struct net *net, struct tc_action *a, u32 index)
243{
244 struct tc_action_net *tn = net_generic(net, mirred_net_id);
245
246 return tcf_hash_search(tn, a, index);
247}
248
249static int mirred_device_event(struct notifier_block *unused,
250 unsigned long event, void *ptr)
251{
252 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
253 struct tcf_mirred *m;
254
255 ASSERT_RTNL();
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) {
260 dev_put(dev);
261 /* Note : no rcu grace period necessary, as
262 * net_device are already rcu protected.
263 */
264 RCU_INIT_POINTER(m->tcfm_dev, NULL);
265 }
266 }
267 spin_unlock_bh(&mirred_list_lock);
268 }
269
270 return NOTIFY_DONE;
271}
272
273static struct notifier_block mirred_device_notifier = {
274 .notifier_call = mirred_device_event,
275};
276
277static struct tc_action_ops act_mirred_ops = {
278 .kind = "mirred",
279 .type = TCA_ACT_MIRRED,
280 .owner = THIS_MODULE,
281 .act = tcf_mirred,
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,
287};
288
289static __net_init int mirred_init_net(struct net *net)
290{
291 struct tc_action_net *tn = net_generic(net, mirred_net_id);
292
293 return tc_action_net_init(tn, &act_mirred_ops, MIRRED_TAB_MASK);
294}
295
296static void __net_exit mirred_exit_net(struct net *net)
297{
298 struct tc_action_net *tn = net_generic(net, mirred_net_id);
299
300 tc_action_net_exit(tn);
301}
302
303static 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),
308};
309
310MODULE_AUTHOR("Jamal Hadi Salim(2002)");
311MODULE_DESCRIPTION("Device Mirror/redirect actions");
312MODULE_LICENSE("GPL");
313
314static int __init mirred_init_module(void)
315{
316 int err = register_netdevice_notifier(&mirred_device_notifier);
317 if (err)
318 return err;
319
320 pr_info("Mirror/redirect action on\n");
321 return tcf_register_action(&act_mirred_ops, &mirred_net_ops);
322}
323
324static void __exit mirred_cleanup_module(void)
325{
326 tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
327 unregister_netdevice_notifier(&mirred_device_notifier);
328}
329
330module_init(mirred_init_module);
331module_exit(mirred_cleanup_module);