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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);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/act_mirred.c packet mirroring and redirect actions
4 *
5 * Authors: Jamal Hadi Salim (2002-4)
6 *
7 * TODO: Add ingress support (and socket redirect support)
8 */
9
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <linux/errno.h>
14#include <linux/skbuff.h>
15#include <linux/rtnetlink.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/gfp.h>
19#include <linux/if_arp.h>
20#include <net/net_namespace.h>
21#include <net/netlink.h>
22#include <net/dst.h>
23#include <net/pkt_sched.h>
24#include <net/pkt_cls.h>
25#include <linux/tc_act/tc_mirred.h>
26#include <net/tc_act/tc_mirred.h>
27#include <net/tc_wrapper.h>
28
29static LIST_HEAD(mirred_list);
30static DEFINE_SPINLOCK(mirred_list_lock);
31
32#define MIRRED_RECURSION_LIMIT 4
33static DEFINE_PER_CPU(unsigned int, mirred_rec_level);
34
35static bool tcf_mirred_is_act_redirect(int action)
36{
37 return action == TCA_EGRESS_REDIR || action == TCA_INGRESS_REDIR;
38}
39
40static bool tcf_mirred_act_wants_ingress(int action)
41{
42 switch (action) {
43 case TCA_EGRESS_REDIR:
44 case TCA_EGRESS_MIRROR:
45 return false;
46 case TCA_INGRESS_REDIR:
47 case TCA_INGRESS_MIRROR:
48 return true;
49 default:
50 BUG();
51 }
52}
53
54static bool tcf_mirred_can_reinsert(int action)
55{
56 switch (action) {
57 case TC_ACT_SHOT:
58 case TC_ACT_STOLEN:
59 case TC_ACT_QUEUED:
60 case TC_ACT_TRAP:
61 return true;
62 }
63 return false;
64}
65
66static struct net_device *tcf_mirred_dev_dereference(struct tcf_mirred *m)
67{
68 return rcu_dereference_protected(m->tcfm_dev,
69 lockdep_is_held(&m->tcf_lock));
70}
71
72static void tcf_mirred_release(struct tc_action *a)
73{
74 struct tcf_mirred *m = to_mirred(a);
75 struct net_device *dev;
76
77 spin_lock(&mirred_list_lock);
78 list_del(&m->tcfm_list);
79 spin_unlock(&mirred_list_lock);
80
81 /* last reference to action, no need to lock */
82 dev = rcu_dereference_protected(m->tcfm_dev, 1);
83 netdev_put(dev, &m->tcfm_dev_tracker);
84}
85
86static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
87 [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
88};
89
90static struct tc_action_ops act_mirred_ops;
91
92static int tcf_mirred_init(struct net *net, struct nlattr *nla,
93 struct nlattr *est, struct tc_action **a,
94 struct tcf_proto *tp,
95 u32 flags, struct netlink_ext_ack *extack)
96{
97 struct tc_action_net *tn = net_generic(net, act_mirred_ops.net_id);
98 bool bind = flags & TCA_ACT_FLAGS_BIND;
99 struct nlattr *tb[TCA_MIRRED_MAX + 1];
100 struct tcf_chain *goto_ch = NULL;
101 bool mac_header_xmit = false;
102 struct tc_mirred *parm;
103 struct tcf_mirred *m;
104 bool exists = false;
105 int ret, err;
106 u32 index;
107
108 if (!nla) {
109 NL_SET_ERR_MSG_MOD(extack, "Mirred requires attributes to be passed");
110 return -EINVAL;
111 }
112 ret = nla_parse_nested_deprecated(tb, TCA_MIRRED_MAX, nla,
113 mirred_policy, extack);
114 if (ret < 0)
115 return ret;
116 if (!tb[TCA_MIRRED_PARMS]) {
117 NL_SET_ERR_MSG_MOD(extack, "Missing required mirred parameters");
118 return -EINVAL;
119 }
120 parm = nla_data(tb[TCA_MIRRED_PARMS]);
121 index = parm->index;
122 err = tcf_idr_check_alloc(tn, &index, a, bind);
123 if (err < 0)
124 return err;
125 exists = err;
126 if (exists && bind)
127 return 0;
128
129 switch (parm->eaction) {
130 case TCA_EGRESS_MIRROR:
131 case TCA_EGRESS_REDIR:
132 case TCA_INGRESS_REDIR:
133 case TCA_INGRESS_MIRROR:
134 break;
135 default:
136 if (exists)
137 tcf_idr_release(*a, bind);
138 else
139 tcf_idr_cleanup(tn, index);
140 NL_SET_ERR_MSG_MOD(extack, "Unknown mirred option");
141 return -EINVAL;
142 }
143
144 if (!exists) {
145 if (!parm->ifindex) {
146 tcf_idr_cleanup(tn, index);
147 NL_SET_ERR_MSG_MOD(extack, "Specified device does not exist");
148 return -EINVAL;
149 }
150 ret = tcf_idr_create_from_flags(tn, index, est, a,
151 &act_mirred_ops, bind, flags);
152 if (ret) {
153 tcf_idr_cleanup(tn, index);
154 return ret;
155 }
156 ret = ACT_P_CREATED;
157 } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
158 tcf_idr_release(*a, bind);
159 return -EEXIST;
160 }
161
162 m = to_mirred(*a);
163 if (ret == ACT_P_CREATED)
164 INIT_LIST_HEAD(&m->tcfm_list);
165
166 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
167 if (err < 0)
168 goto release_idr;
169
170 spin_lock_bh(&m->tcf_lock);
171
172 if (parm->ifindex) {
173 struct net_device *odev, *ndev;
174
175 ndev = dev_get_by_index(net, parm->ifindex);
176 if (!ndev) {
177 spin_unlock_bh(&m->tcf_lock);
178 err = -ENODEV;
179 goto put_chain;
180 }
181 mac_header_xmit = dev_is_mac_header_xmit(ndev);
182 odev = rcu_replace_pointer(m->tcfm_dev, ndev,
183 lockdep_is_held(&m->tcf_lock));
184 netdev_put(odev, &m->tcfm_dev_tracker);
185 netdev_tracker_alloc(ndev, &m->tcfm_dev_tracker, GFP_ATOMIC);
186 m->tcfm_mac_header_xmit = mac_header_xmit;
187 }
188 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
189 m->tcfm_eaction = parm->eaction;
190 spin_unlock_bh(&m->tcf_lock);
191 if (goto_ch)
192 tcf_chain_put_by_act(goto_ch);
193
194 if (ret == ACT_P_CREATED) {
195 spin_lock(&mirred_list_lock);
196 list_add(&m->tcfm_list, &mirred_list);
197 spin_unlock(&mirred_list_lock);
198 }
199
200 return ret;
201put_chain:
202 if (goto_ch)
203 tcf_chain_put_by_act(goto_ch);
204release_idr:
205 tcf_idr_release(*a, bind);
206 return err;
207}
208
209static int tcf_mirred_forward(bool want_ingress, struct sk_buff *skb)
210{
211 int err;
212
213 if (!want_ingress)
214 err = tcf_dev_queue_xmit(skb, dev_queue_xmit);
215 else
216 err = netif_receive_skb(skb);
217
218 return err;
219}
220
221TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb,
222 const struct tc_action *a,
223 struct tcf_result *res)
224{
225 struct tcf_mirred *m = to_mirred(a);
226 struct sk_buff *skb2 = skb;
227 bool m_mac_header_xmit;
228 struct net_device *dev;
229 unsigned int rec_level;
230 int retval, err = 0;
231 bool use_reinsert;
232 bool want_ingress;
233 bool is_redirect;
234 bool expects_nh;
235 bool at_ingress;
236 int m_eaction;
237 int mac_len;
238 bool at_nh;
239
240 rec_level = __this_cpu_inc_return(mirred_rec_level);
241 if (unlikely(rec_level > MIRRED_RECURSION_LIMIT)) {
242 net_warn_ratelimited("Packet exceeded mirred recursion limit on dev %s\n",
243 netdev_name(skb->dev));
244 __this_cpu_dec(mirred_rec_level);
245 return TC_ACT_SHOT;
246 }
247
248 tcf_lastuse_update(&m->tcf_tm);
249 tcf_action_update_bstats(&m->common, skb);
250
251 m_mac_header_xmit = READ_ONCE(m->tcfm_mac_header_xmit);
252 m_eaction = READ_ONCE(m->tcfm_eaction);
253 retval = READ_ONCE(m->tcf_action);
254 dev = rcu_dereference_bh(m->tcfm_dev);
255 if (unlikely(!dev)) {
256 pr_notice_once("tc mirred: target device is gone\n");
257 goto out;
258 }
259
260 if (unlikely(!(dev->flags & IFF_UP))) {
261 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
262 dev->name);
263 goto out;
264 }
265
266 /* we could easily avoid the clone only if called by ingress and clsact;
267 * since we can't easily detect the clsact caller, skip clone only for
268 * ingress - that covers the TC S/W datapath.
269 */
270 is_redirect = tcf_mirred_is_act_redirect(m_eaction);
271 at_ingress = skb_at_tc_ingress(skb);
272 use_reinsert = at_ingress && is_redirect &&
273 tcf_mirred_can_reinsert(retval);
274 if (!use_reinsert) {
275 skb2 = skb_clone(skb, GFP_ATOMIC);
276 if (!skb2)
277 goto out;
278 }
279
280 want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
281
282 /* All mirred/redirected skbs should clear previous ct info */
283 nf_reset_ct(skb2);
284 if (want_ingress && !at_ingress) /* drop dst for egress -> ingress */
285 skb_dst_drop(skb2);
286
287 expects_nh = want_ingress || !m_mac_header_xmit;
288 at_nh = skb->data == skb_network_header(skb);
289 if (at_nh != expects_nh) {
290 mac_len = skb_at_tc_ingress(skb) ? skb->mac_len :
291 skb_network_header(skb) - skb_mac_header(skb);
292 if (expects_nh) {
293 /* target device/action expect data at nh */
294 skb_pull_rcsum(skb2, mac_len);
295 } else {
296 /* target device/action expect data at mac */
297 skb_push_rcsum(skb2, mac_len);
298 }
299 }
300
301 skb2->skb_iif = skb->dev->ifindex;
302 skb2->dev = dev;
303
304 /* mirror is always swallowed */
305 if (is_redirect) {
306 skb_set_redirected(skb2, skb2->tc_at_ingress);
307
308 /* let's the caller reinsert the packet, if possible */
309 if (use_reinsert) {
310 err = tcf_mirred_forward(want_ingress, skb);
311 if (err)
312 tcf_action_inc_overlimit_qstats(&m->common);
313 __this_cpu_dec(mirred_rec_level);
314 return TC_ACT_CONSUMED;
315 }
316 }
317
318 err = tcf_mirred_forward(want_ingress, skb2);
319 if (err) {
320out:
321 tcf_action_inc_overlimit_qstats(&m->common);
322 if (tcf_mirred_is_act_redirect(m_eaction))
323 retval = TC_ACT_SHOT;
324 }
325 __this_cpu_dec(mirred_rec_level);
326
327 return retval;
328}
329
330static void tcf_stats_update(struct tc_action *a, u64 bytes, u64 packets,
331 u64 drops, u64 lastuse, bool hw)
332{
333 struct tcf_mirred *m = to_mirred(a);
334 struct tcf_t *tm = &m->tcf_tm;
335
336 tcf_action_update_stats(a, bytes, packets, drops, hw);
337 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
338}
339
340static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
341 int ref)
342{
343 unsigned char *b = skb_tail_pointer(skb);
344 struct tcf_mirred *m = to_mirred(a);
345 struct tc_mirred opt = {
346 .index = m->tcf_index,
347 .refcnt = refcount_read(&m->tcf_refcnt) - ref,
348 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
349 };
350 struct net_device *dev;
351 struct tcf_t t;
352
353 spin_lock_bh(&m->tcf_lock);
354 opt.action = m->tcf_action;
355 opt.eaction = m->tcfm_eaction;
356 dev = tcf_mirred_dev_dereference(m);
357 if (dev)
358 opt.ifindex = dev->ifindex;
359
360 if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
361 goto nla_put_failure;
362
363 tcf_tm_dump(&t, &m->tcf_tm);
364 if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
365 goto nla_put_failure;
366 spin_unlock_bh(&m->tcf_lock);
367
368 return skb->len;
369
370nla_put_failure:
371 spin_unlock_bh(&m->tcf_lock);
372 nlmsg_trim(skb, b);
373 return -1;
374}
375
376static int mirred_device_event(struct notifier_block *unused,
377 unsigned long event, void *ptr)
378{
379 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
380 struct tcf_mirred *m;
381
382 ASSERT_RTNL();
383 if (event == NETDEV_UNREGISTER) {
384 spin_lock(&mirred_list_lock);
385 list_for_each_entry(m, &mirred_list, tcfm_list) {
386 spin_lock_bh(&m->tcf_lock);
387 if (tcf_mirred_dev_dereference(m) == dev) {
388 netdev_put(dev, &m->tcfm_dev_tracker);
389 /* Note : no rcu grace period necessary, as
390 * net_device are already rcu protected.
391 */
392 RCU_INIT_POINTER(m->tcfm_dev, NULL);
393 }
394 spin_unlock_bh(&m->tcf_lock);
395 }
396 spin_unlock(&mirred_list_lock);
397 }
398
399 return NOTIFY_DONE;
400}
401
402static struct notifier_block mirred_device_notifier = {
403 .notifier_call = mirred_device_event,
404};
405
406static void tcf_mirred_dev_put(void *priv)
407{
408 struct net_device *dev = priv;
409
410 dev_put(dev);
411}
412
413static struct net_device *
414tcf_mirred_get_dev(const struct tc_action *a,
415 tc_action_priv_destructor *destructor)
416{
417 struct tcf_mirred *m = to_mirred(a);
418 struct net_device *dev;
419
420 rcu_read_lock();
421 dev = rcu_dereference(m->tcfm_dev);
422 if (dev) {
423 dev_hold(dev);
424 *destructor = tcf_mirred_dev_put;
425 }
426 rcu_read_unlock();
427
428 return dev;
429}
430
431static size_t tcf_mirred_get_fill_size(const struct tc_action *act)
432{
433 return nla_total_size(sizeof(struct tc_mirred));
434}
435
436static void tcf_offload_mirred_get_dev(struct flow_action_entry *entry,
437 const struct tc_action *act)
438{
439 entry->dev = act->ops->get_dev(act, &entry->destructor);
440 if (!entry->dev)
441 return;
442 entry->destructor_priv = entry->dev;
443}
444
445static int tcf_mirred_offload_act_setup(struct tc_action *act, void *entry_data,
446 u32 *index_inc, bool bind,
447 struct netlink_ext_ack *extack)
448{
449 if (bind) {
450 struct flow_action_entry *entry = entry_data;
451
452 if (is_tcf_mirred_egress_redirect(act)) {
453 entry->id = FLOW_ACTION_REDIRECT;
454 tcf_offload_mirred_get_dev(entry, act);
455 } else if (is_tcf_mirred_egress_mirror(act)) {
456 entry->id = FLOW_ACTION_MIRRED;
457 tcf_offload_mirred_get_dev(entry, act);
458 } else if (is_tcf_mirred_ingress_redirect(act)) {
459 entry->id = FLOW_ACTION_REDIRECT_INGRESS;
460 tcf_offload_mirred_get_dev(entry, act);
461 } else if (is_tcf_mirred_ingress_mirror(act)) {
462 entry->id = FLOW_ACTION_MIRRED_INGRESS;
463 tcf_offload_mirred_get_dev(entry, act);
464 } else {
465 NL_SET_ERR_MSG_MOD(extack, "Unsupported mirred offload");
466 return -EOPNOTSUPP;
467 }
468 *index_inc = 1;
469 } else {
470 struct flow_offload_action *fl_action = entry_data;
471
472 if (is_tcf_mirred_egress_redirect(act))
473 fl_action->id = FLOW_ACTION_REDIRECT;
474 else if (is_tcf_mirred_egress_mirror(act))
475 fl_action->id = FLOW_ACTION_MIRRED;
476 else if (is_tcf_mirred_ingress_redirect(act))
477 fl_action->id = FLOW_ACTION_REDIRECT_INGRESS;
478 else if (is_tcf_mirred_ingress_mirror(act))
479 fl_action->id = FLOW_ACTION_MIRRED_INGRESS;
480 else
481 return -EOPNOTSUPP;
482 }
483
484 return 0;
485}
486
487static struct tc_action_ops act_mirred_ops = {
488 .kind = "mirred",
489 .id = TCA_ID_MIRRED,
490 .owner = THIS_MODULE,
491 .act = tcf_mirred_act,
492 .stats_update = tcf_stats_update,
493 .dump = tcf_mirred_dump,
494 .cleanup = tcf_mirred_release,
495 .init = tcf_mirred_init,
496 .get_fill_size = tcf_mirred_get_fill_size,
497 .offload_act_setup = tcf_mirred_offload_act_setup,
498 .size = sizeof(struct tcf_mirred),
499 .get_dev = tcf_mirred_get_dev,
500};
501
502static __net_init int mirred_init_net(struct net *net)
503{
504 struct tc_action_net *tn = net_generic(net, act_mirred_ops.net_id);
505
506 return tc_action_net_init(net, tn, &act_mirred_ops);
507}
508
509static void __net_exit mirred_exit_net(struct list_head *net_list)
510{
511 tc_action_net_exit(net_list, act_mirred_ops.net_id);
512}
513
514static struct pernet_operations mirred_net_ops = {
515 .init = mirred_init_net,
516 .exit_batch = mirred_exit_net,
517 .id = &act_mirred_ops.net_id,
518 .size = sizeof(struct tc_action_net),
519};
520
521MODULE_AUTHOR("Jamal Hadi Salim(2002)");
522MODULE_DESCRIPTION("Device Mirror/redirect actions");
523MODULE_LICENSE("GPL");
524
525static int __init mirred_init_module(void)
526{
527 int err = register_netdevice_notifier(&mirred_device_notifier);
528 if (err)
529 return err;
530
531 pr_info("Mirror/redirect action on\n");
532 err = tcf_register_action(&act_mirred_ops, &mirred_net_ops);
533 if (err)
534 unregister_netdevice_notifier(&mirred_device_notifier);
535
536 return err;
537}
538
539static void __exit mirred_cleanup_module(void)
540{
541 tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
542 unregister_netdevice_notifier(&mirred_device_notifier);
543}
544
545module_init(mirred_init_module);
546module_exit(mirred_cleanup_module);