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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* drivers/net/ifb.c:
3
4 The purpose of this driver is to provide a device that allows
5 for sharing of resources:
6
7 1) qdiscs/policies that are per device as opposed to system wide.
8 ifb allows for a device which can be redirected to thus providing
9 an impression of sharing.
10
11 2) Allows for queueing incoming traffic for shaping instead of
12 dropping.
13
14 The original concept is based on what is known as the IMQ
15 driver initially written by Martin Devera, later rewritten
16 by Patrick McHardy and then maintained by Andre Correa.
17
18 You need the tc action mirror or redirect to feed this device
19 packets.
20
21
22 Authors: Jamal Hadi Salim (2005)
23
24*/
25
26
27#include <linux/module.h>
28#include <linux/kernel.h>
29#include <linux/netdevice.h>
30#include <linux/etherdevice.h>
31#include <linux/init.h>
32#include <linux/interrupt.h>
33#include <linux/moduleparam.h>
34#include <net/pkt_sched.h>
35#include <net/net_namespace.h>
36
37#define TX_Q_LIMIT 32
38struct ifb_q_private {
39 struct net_device *dev;
40 struct tasklet_struct ifb_tasklet;
41 int tasklet_pending;
42 int txqnum;
43 struct sk_buff_head rq;
44 u64 rx_packets;
45 u64 rx_bytes;
46 struct u64_stats_sync rsync;
47
48 struct u64_stats_sync tsync;
49 u64 tx_packets;
50 u64 tx_bytes;
51 struct sk_buff_head tq;
52} ____cacheline_aligned_in_smp;
53
54struct ifb_dev_private {
55 struct ifb_q_private *tx_private;
56};
57
58static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
59static int ifb_open(struct net_device *dev);
60static int ifb_close(struct net_device *dev);
61
62static void ifb_ri_tasklet(struct tasklet_struct *t)
63{
64 struct ifb_q_private *txp = from_tasklet(txp, t, ifb_tasklet);
65 struct netdev_queue *txq;
66 struct sk_buff *skb;
67
68 txq = netdev_get_tx_queue(txp->dev, txp->txqnum);
69 skb = skb_peek(&txp->tq);
70 if (!skb) {
71 if (!__netif_tx_trylock(txq))
72 goto resched;
73 skb_queue_splice_tail_init(&txp->rq, &txp->tq);
74 __netif_tx_unlock(txq);
75 }
76
77 while ((skb = __skb_dequeue(&txp->tq)) != NULL) {
78 skb->redirected = 0;
79 skb->tc_skip_classify = 1;
80
81 u64_stats_update_begin(&txp->tsync);
82 txp->tx_packets++;
83 txp->tx_bytes += skb->len;
84 u64_stats_update_end(&txp->tsync);
85
86 rcu_read_lock();
87 skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif);
88 if (!skb->dev) {
89 rcu_read_unlock();
90 dev_kfree_skb(skb);
91 txp->dev->stats.tx_dropped++;
92 if (skb_queue_len(&txp->tq) != 0)
93 goto resched;
94 break;
95 }
96 rcu_read_unlock();
97 skb->skb_iif = txp->dev->ifindex;
98
99 if (!skb->from_ingress) {
100 dev_queue_xmit(skb);
101 } else {
102 skb_pull_rcsum(skb, skb->mac_len);
103 netif_receive_skb(skb);
104 }
105 }
106
107 if (__netif_tx_trylock(txq)) {
108 skb = skb_peek(&txp->rq);
109 if (!skb) {
110 txp->tasklet_pending = 0;
111 if (netif_tx_queue_stopped(txq))
112 netif_tx_wake_queue(txq);
113 } else {
114 __netif_tx_unlock(txq);
115 goto resched;
116 }
117 __netif_tx_unlock(txq);
118 } else {
119resched:
120 txp->tasklet_pending = 1;
121 tasklet_schedule(&txp->ifb_tasklet);
122 }
123
124}
125
126static void ifb_stats64(struct net_device *dev,
127 struct rtnl_link_stats64 *stats)
128{
129 struct ifb_dev_private *dp = netdev_priv(dev);
130 struct ifb_q_private *txp = dp->tx_private;
131 unsigned int start;
132 u64 packets, bytes;
133 int i;
134
135 for (i = 0; i < dev->num_tx_queues; i++,txp++) {
136 do {
137 start = u64_stats_fetch_begin_irq(&txp->rsync);
138 packets = txp->rx_packets;
139 bytes = txp->rx_bytes;
140 } while (u64_stats_fetch_retry_irq(&txp->rsync, start));
141 stats->rx_packets += packets;
142 stats->rx_bytes += bytes;
143
144 do {
145 start = u64_stats_fetch_begin_irq(&txp->tsync);
146 packets = txp->tx_packets;
147 bytes = txp->tx_bytes;
148 } while (u64_stats_fetch_retry_irq(&txp->tsync, start));
149 stats->tx_packets += packets;
150 stats->tx_bytes += bytes;
151 }
152 stats->rx_dropped = dev->stats.rx_dropped;
153 stats->tx_dropped = dev->stats.tx_dropped;
154}
155
156static int ifb_dev_init(struct net_device *dev)
157{
158 struct ifb_dev_private *dp = netdev_priv(dev);
159 struct ifb_q_private *txp;
160 int i;
161
162 txp = kcalloc(dev->num_tx_queues, sizeof(*txp), GFP_KERNEL);
163 if (!txp)
164 return -ENOMEM;
165 dp->tx_private = txp;
166 for (i = 0; i < dev->num_tx_queues; i++,txp++) {
167 txp->txqnum = i;
168 txp->dev = dev;
169 __skb_queue_head_init(&txp->rq);
170 __skb_queue_head_init(&txp->tq);
171 u64_stats_init(&txp->rsync);
172 u64_stats_init(&txp->tsync);
173 tasklet_setup(&txp->ifb_tasklet, ifb_ri_tasklet);
174 netif_tx_start_queue(netdev_get_tx_queue(dev, i));
175 }
176 return 0;
177}
178
179static const struct net_device_ops ifb_netdev_ops = {
180 .ndo_open = ifb_open,
181 .ndo_stop = ifb_close,
182 .ndo_get_stats64 = ifb_stats64,
183 .ndo_start_xmit = ifb_xmit,
184 .ndo_validate_addr = eth_validate_addr,
185 .ndo_init = ifb_dev_init,
186};
187
188#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_FRAGLIST | \
189 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
190 NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX | \
191 NETIF_F_HW_VLAN_STAG_TX)
192
193static void ifb_dev_free(struct net_device *dev)
194{
195 struct ifb_dev_private *dp = netdev_priv(dev);
196 struct ifb_q_private *txp = dp->tx_private;
197 int i;
198
199 for (i = 0; i < dev->num_tx_queues; i++,txp++) {
200 tasklet_kill(&txp->ifb_tasklet);
201 __skb_queue_purge(&txp->rq);
202 __skb_queue_purge(&txp->tq);
203 }
204 kfree(dp->tx_private);
205}
206
207static void ifb_setup(struct net_device *dev)
208{
209 /* Initialize the device structure. */
210 dev->netdev_ops = &ifb_netdev_ops;
211
212 /* Fill in device structure with ethernet-generic values. */
213 ether_setup(dev);
214 dev->tx_queue_len = TX_Q_LIMIT;
215
216 dev->features |= IFB_FEATURES;
217 dev->hw_features |= dev->features;
218 dev->hw_enc_features |= dev->features;
219 dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
220 NETIF_F_HW_VLAN_STAG_TX);
221
222 dev->flags |= IFF_NOARP;
223 dev->flags &= ~IFF_MULTICAST;
224 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
225 netif_keep_dst(dev);
226 eth_hw_addr_random(dev);
227 dev->needs_free_netdev = true;
228 dev->priv_destructor = ifb_dev_free;
229
230 dev->min_mtu = 0;
231 dev->max_mtu = 0;
232}
233
234static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
235{
236 struct ifb_dev_private *dp = netdev_priv(dev);
237 struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
238
239 u64_stats_update_begin(&txp->rsync);
240 txp->rx_packets++;
241 txp->rx_bytes += skb->len;
242 u64_stats_update_end(&txp->rsync);
243
244 if (!skb->redirected || !skb->skb_iif) {
245 dev_kfree_skb(skb);
246 dev->stats.rx_dropped++;
247 return NETDEV_TX_OK;
248 }
249
250 if (skb_queue_len(&txp->rq) >= dev->tx_queue_len)
251 netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum));
252
253 __skb_queue_tail(&txp->rq, skb);
254 if (!txp->tasklet_pending) {
255 txp->tasklet_pending = 1;
256 tasklet_schedule(&txp->ifb_tasklet);
257 }
258
259 return NETDEV_TX_OK;
260}
261
262static int ifb_close(struct net_device *dev)
263{
264 netif_tx_stop_all_queues(dev);
265 return 0;
266}
267
268static int ifb_open(struct net_device *dev)
269{
270 netif_tx_start_all_queues(dev);
271 return 0;
272}
273
274static int ifb_validate(struct nlattr *tb[], struct nlattr *data[],
275 struct netlink_ext_ack *extack)
276{
277 if (tb[IFLA_ADDRESS]) {
278 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
279 return -EINVAL;
280 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
281 return -EADDRNOTAVAIL;
282 }
283 return 0;
284}
285
286static struct rtnl_link_ops ifb_link_ops __read_mostly = {
287 .kind = "ifb",
288 .priv_size = sizeof(struct ifb_dev_private),
289 .setup = ifb_setup,
290 .validate = ifb_validate,
291};
292
293/* Number of ifb devices to be set up by this module.
294 * Note that these legacy devices have one queue.
295 * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb
296 */
297static int numifbs = 2;
298module_param(numifbs, int, 0);
299MODULE_PARM_DESC(numifbs, "Number of ifb devices");
300
301static int __init ifb_init_one(int index)
302{
303 struct net_device *dev_ifb;
304 int err;
305
306 dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d",
307 NET_NAME_UNKNOWN, ifb_setup);
308
309 if (!dev_ifb)
310 return -ENOMEM;
311
312 dev_ifb->rtnl_link_ops = &ifb_link_ops;
313 err = register_netdevice(dev_ifb);
314 if (err < 0)
315 goto err;
316
317 return 0;
318
319err:
320 free_netdev(dev_ifb);
321 return err;
322}
323
324static int __init ifb_init_module(void)
325{
326 int i, err;
327
328 down_write(&pernet_ops_rwsem);
329 rtnl_lock();
330 err = __rtnl_link_register(&ifb_link_ops);
331 if (err < 0)
332 goto out;
333
334 for (i = 0; i < numifbs && !err; i++) {
335 err = ifb_init_one(i);
336 cond_resched();
337 }
338 if (err)
339 __rtnl_link_unregister(&ifb_link_ops);
340
341out:
342 rtnl_unlock();
343 up_write(&pernet_ops_rwsem);
344
345 return err;
346}
347
348static void __exit ifb_cleanup_module(void)
349{
350 rtnl_link_unregister(&ifb_link_ops);
351}
352
353module_init(ifb_init_module);
354module_exit(ifb_cleanup_module);
355MODULE_LICENSE("GPL");
356MODULE_AUTHOR("Jamal Hadi Salim");
357MODULE_ALIAS_RTNL_LINK("ifb");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* drivers/net/ifb.c:
3
4 The purpose of this driver is to provide a device that allows
5 for sharing of resources:
6
7 1) qdiscs/policies that are per device as opposed to system wide.
8 ifb allows for a device which can be redirected to thus providing
9 an impression of sharing.
10
11 2) Allows for queueing incoming traffic for shaping instead of
12 dropping.
13
14 The original concept is based on what is known as the IMQ
15 driver initially written by Martin Devera, later rewritten
16 by Patrick McHardy and then maintained by Andre Correa.
17
18 You need the tc action mirror or redirect to feed this device
19 packets.
20
21
22 Authors: Jamal Hadi Salim (2005)
23
24*/
25
26
27#include <linux/module.h>
28#include <linux/kernel.h>
29#include <linux/netdevice.h>
30#include <linux/etherdevice.h>
31#include <linux/init.h>
32#include <linux/interrupt.h>
33#include <linux/moduleparam.h>
34#include <net/pkt_sched.h>
35#include <net/net_namespace.h>
36
37#define TX_Q_LIMIT 32
38struct ifb_q_private {
39 struct net_device *dev;
40 struct tasklet_struct ifb_tasklet;
41 int tasklet_pending;
42 int txqnum;
43 struct sk_buff_head rq;
44 u64 rx_packets;
45 u64 rx_bytes;
46 struct u64_stats_sync rsync;
47
48 struct u64_stats_sync tsync;
49 u64 tx_packets;
50 u64 tx_bytes;
51 struct sk_buff_head tq;
52} ____cacheline_aligned_in_smp;
53
54struct ifb_dev_private {
55 struct ifb_q_private *tx_private;
56};
57
58static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
59static int ifb_open(struct net_device *dev);
60static int ifb_close(struct net_device *dev);
61
62static void ifb_ri_tasklet(unsigned long _txp)
63{
64 struct ifb_q_private *txp = (struct ifb_q_private *)_txp;
65 struct netdev_queue *txq;
66 struct sk_buff *skb;
67
68 txq = netdev_get_tx_queue(txp->dev, txp->txqnum);
69 skb = skb_peek(&txp->tq);
70 if (!skb) {
71 if (!__netif_tx_trylock(txq))
72 goto resched;
73 skb_queue_splice_tail_init(&txp->rq, &txp->tq);
74 __netif_tx_unlock(txq);
75 }
76
77 while ((skb = __skb_dequeue(&txp->tq)) != NULL) {
78 skb->redirected = 0;
79 skb->tc_skip_classify = 1;
80
81 u64_stats_update_begin(&txp->tsync);
82 txp->tx_packets++;
83 txp->tx_bytes += skb->len;
84 u64_stats_update_end(&txp->tsync);
85
86 rcu_read_lock();
87 skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif);
88 if (!skb->dev) {
89 rcu_read_unlock();
90 dev_kfree_skb(skb);
91 txp->dev->stats.tx_dropped++;
92 if (skb_queue_len(&txp->tq) != 0)
93 goto resched;
94 break;
95 }
96 rcu_read_unlock();
97 skb->skb_iif = txp->dev->ifindex;
98
99 if (!skb->from_ingress) {
100 dev_queue_xmit(skb);
101 } else {
102 skb_pull_rcsum(skb, skb->mac_len);
103 netif_receive_skb(skb);
104 }
105 }
106
107 if (__netif_tx_trylock(txq)) {
108 skb = skb_peek(&txp->rq);
109 if (!skb) {
110 txp->tasklet_pending = 0;
111 if (netif_tx_queue_stopped(txq))
112 netif_tx_wake_queue(txq);
113 } else {
114 __netif_tx_unlock(txq);
115 goto resched;
116 }
117 __netif_tx_unlock(txq);
118 } else {
119resched:
120 txp->tasklet_pending = 1;
121 tasklet_schedule(&txp->ifb_tasklet);
122 }
123
124}
125
126static void ifb_stats64(struct net_device *dev,
127 struct rtnl_link_stats64 *stats)
128{
129 struct ifb_dev_private *dp = netdev_priv(dev);
130 struct ifb_q_private *txp = dp->tx_private;
131 unsigned int start;
132 u64 packets, bytes;
133 int i;
134
135 for (i = 0; i < dev->num_tx_queues; i++,txp++) {
136 do {
137 start = u64_stats_fetch_begin_irq(&txp->rsync);
138 packets = txp->rx_packets;
139 bytes = txp->rx_bytes;
140 } while (u64_stats_fetch_retry_irq(&txp->rsync, start));
141 stats->rx_packets += packets;
142 stats->rx_bytes += bytes;
143
144 do {
145 start = u64_stats_fetch_begin_irq(&txp->tsync);
146 packets = txp->tx_packets;
147 bytes = txp->tx_bytes;
148 } while (u64_stats_fetch_retry_irq(&txp->tsync, start));
149 stats->tx_packets += packets;
150 stats->tx_bytes += bytes;
151 }
152 stats->rx_dropped = dev->stats.rx_dropped;
153 stats->tx_dropped = dev->stats.tx_dropped;
154}
155
156static int ifb_dev_init(struct net_device *dev)
157{
158 struct ifb_dev_private *dp = netdev_priv(dev);
159 struct ifb_q_private *txp;
160 int i;
161
162 txp = kcalloc(dev->num_tx_queues, sizeof(*txp), GFP_KERNEL);
163 if (!txp)
164 return -ENOMEM;
165 dp->tx_private = txp;
166 for (i = 0; i < dev->num_tx_queues; i++,txp++) {
167 txp->txqnum = i;
168 txp->dev = dev;
169 __skb_queue_head_init(&txp->rq);
170 __skb_queue_head_init(&txp->tq);
171 u64_stats_init(&txp->rsync);
172 u64_stats_init(&txp->tsync);
173 tasklet_init(&txp->ifb_tasklet, ifb_ri_tasklet,
174 (unsigned long)txp);
175 netif_tx_start_queue(netdev_get_tx_queue(dev, i));
176 }
177 return 0;
178}
179
180static const struct net_device_ops ifb_netdev_ops = {
181 .ndo_open = ifb_open,
182 .ndo_stop = ifb_close,
183 .ndo_get_stats64 = ifb_stats64,
184 .ndo_start_xmit = ifb_xmit,
185 .ndo_validate_addr = eth_validate_addr,
186 .ndo_init = ifb_dev_init,
187};
188
189#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_FRAGLIST | \
190 NETIF_F_TSO_ECN | NETIF_F_TSO | NETIF_F_TSO6 | \
191 NETIF_F_GSO_ENCAP_ALL | \
192 NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX | \
193 NETIF_F_HW_VLAN_STAG_TX)
194
195static void ifb_dev_free(struct net_device *dev)
196{
197 struct ifb_dev_private *dp = netdev_priv(dev);
198 struct ifb_q_private *txp = dp->tx_private;
199 int i;
200
201 for (i = 0; i < dev->num_tx_queues; i++,txp++) {
202 tasklet_kill(&txp->ifb_tasklet);
203 __skb_queue_purge(&txp->rq);
204 __skb_queue_purge(&txp->tq);
205 }
206 kfree(dp->tx_private);
207}
208
209static void ifb_setup(struct net_device *dev)
210{
211 /* Initialize the device structure. */
212 dev->netdev_ops = &ifb_netdev_ops;
213
214 /* Fill in device structure with ethernet-generic values. */
215 ether_setup(dev);
216 dev->tx_queue_len = TX_Q_LIMIT;
217
218 dev->features |= IFB_FEATURES;
219 dev->hw_features |= dev->features;
220 dev->hw_enc_features |= dev->features;
221 dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
222 NETIF_F_HW_VLAN_STAG_TX);
223
224 dev->flags |= IFF_NOARP;
225 dev->flags &= ~IFF_MULTICAST;
226 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
227 netif_keep_dst(dev);
228 eth_hw_addr_random(dev);
229 dev->needs_free_netdev = true;
230 dev->priv_destructor = ifb_dev_free;
231
232 dev->min_mtu = 0;
233 dev->max_mtu = 0;
234}
235
236static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
237{
238 struct ifb_dev_private *dp = netdev_priv(dev);
239 struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
240
241 u64_stats_update_begin(&txp->rsync);
242 txp->rx_packets++;
243 txp->rx_bytes += skb->len;
244 u64_stats_update_end(&txp->rsync);
245
246 if (!skb->redirected || !skb->skb_iif) {
247 dev_kfree_skb(skb);
248 dev->stats.rx_dropped++;
249 return NETDEV_TX_OK;
250 }
251
252 if (skb_queue_len(&txp->rq) >= dev->tx_queue_len)
253 netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum));
254
255 __skb_queue_tail(&txp->rq, skb);
256 if (!txp->tasklet_pending) {
257 txp->tasklet_pending = 1;
258 tasklet_schedule(&txp->ifb_tasklet);
259 }
260
261 return NETDEV_TX_OK;
262}
263
264static int ifb_close(struct net_device *dev)
265{
266 netif_tx_stop_all_queues(dev);
267 return 0;
268}
269
270static int ifb_open(struct net_device *dev)
271{
272 netif_tx_start_all_queues(dev);
273 return 0;
274}
275
276static int ifb_validate(struct nlattr *tb[], struct nlattr *data[],
277 struct netlink_ext_ack *extack)
278{
279 if (tb[IFLA_ADDRESS]) {
280 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
281 return -EINVAL;
282 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
283 return -EADDRNOTAVAIL;
284 }
285 return 0;
286}
287
288static struct rtnl_link_ops ifb_link_ops __read_mostly = {
289 .kind = "ifb",
290 .priv_size = sizeof(struct ifb_dev_private),
291 .setup = ifb_setup,
292 .validate = ifb_validate,
293};
294
295/* Number of ifb devices to be set up by this module.
296 * Note that these legacy devices have one queue.
297 * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb
298 */
299static int numifbs = 2;
300module_param(numifbs, int, 0);
301MODULE_PARM_DESC(numifbs, "Number of ifb devices");
302
303static int __init ifb_init_one(int index)
304{
305 struct net_device *dev_ifb;
306 int err;
307
308 dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d",
309 NET_NAME_UNKNOWN, ifb_setup);
310
311 if (!dev_ifb)
312 return -ENOMEM;
313
314 dev_ifb->rtnl_link_ops = &ifb_link_ops;
315 err = register_netdevice(dev_ifb);
316 if (err < 0)
317 goto err;
318
319 return 0;
320
321err:
322 free_netdev(dev_ifb);
323 return err;
324}
325
326static int __init ifb_init_module(void)
327{
328 int i, err;
329
330 down_write(&pernet_ops_rwsem);
331 rtnl_lock();
332 err = __rtnl_link_register(&ifb_link_ops);
333 if (err < 0)
334 goto out;
335
336 for (i = 0; i < numifbs && !err; i++) {
337 err = ifb_init_one(i);
338 cond_resched();
339 }
340 if (err)
341 __rtnl_link_unregister(&ifb_link_ops);
342
343out:
344 rtnl_unlock();
345 up_write(&pernet_ops_rwsem);
346
347 return err;
348}
349
350static void __exit ifb_cleanup_module(void)
351{
352 rtnl_link_unregister(&ifb_link_ops);
353}
354
355module_init(ifb_init_module);
356module_exit(ifb_cleanup_module);
357MODULE_LICENSE("GPL");
358MODULE_AUTHOR("Jamal Hadi Salim");
359MODULE_ALIAS_RTNL_LINK("ifb");