Linux Audio

Check our new training course

Loading...
v4.17
  1/* drivers/net/ifb.c:
  2
  3	The purpose of this driver is to provide a device that allows
  4	for sharing of resources:
  5
  6	1) qdiscs/policies that are per device as opposed to system wide.
  7	ifb allows for a device which can be redirected to thus providing
  8	an impression of sharing.
  9
 10	2) Allows for queueing incoming traffic for shaping instead of
 11	dropping.
 12
 13	The original concept is based on what is known as the IMQ
 14	driver initially written by Martin Devera, later rewritten
 15	by Patrick McHardy and then maintained by Andre Correa.
 16
 17	You need the tc action  mirror or redirect to feed this device
 18       	packets.
 19
 20	This program is free software; you can redistribute it and/or
 21	modify it under the terms of the GNU General Public License
 22	as published by the Free Software Foundation; either version
 23	2 of the License, or (at your option) any later version.
 24
 25  	Authors:	Jamal Hadi Salim (2005)
 26
 27*/
 28
 29
 30#include <linux/module.h>
 31#include <linux/kernel.h>
 32#include <linux/netdevice.h>
 33#include <linux/etherdevice.h>
 34#include <linux/init.h>
 35#include <linux/interrupt.h>
 36#include <linux/moduleparam.h>
 37#include <net/pkt_sched.h>
 38#include <net/net_namespace.h>
 39
 40#define TX_Q_LIMIT    32
 41struct ifb_q_private {
 42	struct net_device	*dev;
 43	struct tasklet_struct   ifb_tasklet;
 44	int			tasklet_pending;
 45	int			txqnum;
 46	struct sk_buff_head     rq;
 47	u64			rx_packets;
 48	u64			rx_bytes;
 49	struct u64_stats_sync	rsync;
 50
 51	struct u64_stats_sync	tsync;
 52	u64			tx_packets;
 53	u64			tx_bytes;
 54	struct sk_buff_head     tq;
 55} ____cacheline_aligned_in_smp;
 56
 57struct ifb_dev_private {
 58	struct ifb_q_private *tx_private;
 59};
 60
 61static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
 62static int ifb_open(struct net_device *dev);
 63static int ifb_close(struct net_device *dev);
 64
 65static void ifb_ri_tasklet(unsigned long _txp)
 66{
 67	struct ifb_q_private *txp = (struct ifb_q_private *)_txp;
 68	struct netdev_queue *txq;
 69	struct sk_buff *skb;
 70
 71	txq = netdev_get_tx_queue(txp->dev, txp->txqnum);
 72	skb = skb_peek(&txp->tq);
 73	if (!skb) {
 74		if (!__netif_tx_trylock(txq))
 75			goto resched;
 76		skb_queue_splice_tail_init(&txp->rq, &txp->tq);
 77		__netif_tx_unlock(txq);
 78	}
 79
 80	while ((skb = __skb_dequeue(&txp->tq)) != NULL) {
 81		skb->tc_redirected = 0;
 82		skb->tc_skip_classify = 1;
 
 
 83
 84		u64_stats_update_begin(&txp->tsync);
 85		txp->tx_packets++;
 86		txp->tx_bytes += skb->len;
 87		u64_stats_update_end(&txp->tsync);
 88
 89		rcu_read_lock();
 90		skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif);
 91		if (!skb->dev) {
 92			rcu_read_unlock();
 93			dev_kfree_skb(skb);
 94			txp->dev->stats.tx_dropped++;
 95			if (skb_queue_len(&txp->tq) != 0)
 96				goto resched;
 97			break;
 98		}
 99		rcu_read_unlock();
100		skb->skb_iif = txp->dev->ifindex;
101
102		if (!skb->tc_from_ingress) {
103			dev_queue_xmit(skb);
104		} else {
105			skb_pull(skb, skb->mac_len);
106			netif_receive_skb(skb);
107		}
 
108	}
109
110	if (__netif_tx_trylock(txq)) {
111		skb = skb_peek(&txp->rq);
112		if (!skb) {
113			txp->tasklet_pending = 0;
114			if (netif_tx_queue_stopped(txq))
115				netif_tx_wake_queue(txq);
116		} else {
117			__netif_tx_unlock(txq);
118			goto resched;
119		}
120		__netif_tx_unlock(txq);
121	} else {
122resched:
123		txp->tasklet_pending = 1;
124		tasklet_schedule(&txp->ifb_tasklet);
125	}
126
127}
128
129static void ifb_stats64(struct net_device *dev,
130			struct rtnl_link_stats64 *stats)
131{
132	struct ifb_dev_private *dp = netdev_priv(dev);
133	struct ifb_q_private *txp = dp->tx_private;
134	unsigned int start;
135	u64 packets, bytes;
136	int i;
137
138	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
139		do {
140			start = u64_stats_fetch_begin_irq(&txp->rsync);
141			packets = txp->rx_packets;
142			bytes = txp->rx_bytes;
143		} while (u64_stats_fetch_retry_irq(&txp->rsync, start));
144		stats->rx_packets += packets;
145		stats->rx_bytes += bytes;
146
147		do {
148			start = u64_stats_fetch_begin_irq(&txp->tsync);
149			packets = txp->tx_packets;
150			bytes = txp->tx_bytes;
151		} while (u64_stats_fetch_retry_irq(&txp->tsync, start));
152		stats->tx_packets += packets;
153		stats->tx_bytes += bytes;
154	}
155	stats->rx_dropped = dev->stats.rx_dropped;
156	stats->tx_dropped = dev->stats.tx_dropped;
 
 
157}
158
159static int ifb_dev_init(struct net_device *dev)
160{
161	struct ifb_dev_private *dp = netdev_priv(dev);
162	struct ifb_q_private *txp;
163	int i;
164
165	txp = kcalloc(dev->num_tx_queues, sizeof(*txp), GFP_KERNEL);
166	if (!txp)
167		return -ENOMEM;
168	dp->tx_private = txp;
169	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
170		txp->txqnum = i;
171		txp->dev = dev;
172		__skb_queue_head_init(&txp->rq);
173		__skb_queue_head_init(&txp->tq);
174		u64_stats_init(&txp->rsync);
175		u64_stats_init(&txp->tsync);
176		tasklet_init(&txp->ifb_tasklet, ifb_ri_tasklet,
177			     (unsigned long)txp);
178		netif_tx_start_queue(netdev_get_tx_queue(dev, i));
179	}
180	return 0;
181}
182
183static const struct net_device_ops ifb_netdev_ops = {
184	.ndo_open	= ifb_open,
185	.ndo_stop	= ifb_close,
186	.ndo_get_stats64 = ifb_stats64,
187	.ndo_start_xmit	= ifb_xmit,
188	.ndo_validate_addr = eth_validate_addr,
189	.ndo_init	= ifb_dev_init,
190};
191
192#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG  | NETIF_F_FRAGLIST	| \
193		      NETIF_F_TSO_ECN | NETIF_F_TSO | NETIF_F_TSO6	| \
194		      NETIF_F_GSO_ENCAP_ALL 				| \
195		      NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX		| \
196		      NETIF_F_HW_VLAN_STAG_TX)
197
198static void ifb_dev_free(struct net_device *dev)
199{
200	struct ifb_dev_private *dp = netdev_priv(dev);
201	struct ifb_q_private *txp = dp->tx_private;
202	int i;
203
204	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
205		tasklet_kill(&txp->ifb_tasklet);
206		__skb_queue_purge(&txp->rq);
207		__skb_queue_purge(&txp->tq);
208	}
209	kfree(dp->tx_private);
 
210}
211
212static void ifb_setup(struct net_device *dev)
213{
214	/* Initialize the device structure. */
215	dev->netdev_ops = &ifb_netdev_ops;
216
217	/* Fill in device structure with ethernet-generic values. */
218	ether_setup(dev);
219	dev->tx_queue_len = TX_Q_LIMIT;
220
221	dev->features |= IFB_FEATURES;
222	dev->hw_features |= dev->features;
223	dev->hw_enc_features |= dev->features;
224	dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
225					       NETIF_F_HW_VLAN_STAG_TX);
226
227	dev->flags |= IFF_NOARP;
228	dev->flags &= ~IFF_MULTICAST;
229	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
230	netif_keep_dst(dev);
231	eth_hw_addr_random(dev);
232	dev->needs_free_netdev = true;
233	dev->priv_destructor = ifb_dev_free;
234
235	dev->min_mtu = 0;
236	dev->max_mtu = 0;
237}
238
239static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
240{
241	struct ifb_dev_private *dp = netdev_priv(dev);
 
242	struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
243
244	u64_stats_update_begin(&txp->rsync);
245	txp->rx_packets++;
246	txp->rx_bytes += skb->len;
247	u64_stats_update_end(&txp->rsync);
248
249	if (!skb->tc_redirected || !skb->skb_iif) {
250		dev_kfree_skb(skb);
251		dev->stats.rx_dropped++;
252		return NETDEV_TX_OK;
253	}
254
255	if (skb_queue_len(&txp->rq) >= dev->tx_queue_len)
256		netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum));
257
258	__skb_queue_tail(&txp->rq, skb);
259	if (!txp->tasklet_pending) {
260		txp->tasklet_pending = 1;
261		tasklet_schedule(&txp->ifb_tasklet);
262	}
263
264	return NETDEV_TX_OK;
265}
266
267static int ifb_close(struct net_device *dev)
268{
269	netif_tx_stop_all_queues(dev);
270	return 0;
271}
272
273static int ifb_open(struct net_device *dev)
274{
275	netif_tx_start_all_queues(dev);
276	return 0;
277}
278
279static int ifb_validate(struct nlattr *tb[], struct nlattr *data[],
280			struct netlink_ext_ack *extack)
281{
282	if (tb[IFLA_ADDRESS]) {
283		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
284			return -EINVAL;
285		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
286			return -EADDRNOTAVAIL;
287	}
288	return 0;
289}
290
291static struct rtnl_link_ops ifb_link_ops __read_mostly = {
292	.kind		= "ifb",
293	.priv_size	= sizeof(struct ifb_dev_private),
294	.setup		= ifb_setup,
295	.validate	= ifb_validate,
296};
297
298/* Number of ifb devices to be set up by this module.
299 * Note that these legacy devices have one queue.
300 * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb
301 */
302static int numifbs = 2;
303module_param(numifbs, int, 0);
304MODULE_PARM_DESC(numifbs, "Number of ifb devices");
305
306static int __init ifb_init_one(int index)
307{
308	struct net_device *dev_ifb;
309	int err;
310
311	dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d",
312			       NET_NAME_UNKNOWN, ifb_setup);
313
314	if (!dev_ifb)
315		return -ENOMEM;
316
317	dev_ifb->rtnl_link_ops = &ifb_link_ops;
318	err = register_netdevice(dev_ifb);
319	if (err < 0)
320		goto err;
321
322	return 0;
323
324err:
325	free_netdev(dev_ifb);
326	return err;
327}
328
329static int __init ifb_init_module(void)
330{
331	int i, err;
332
333	down_write(&pernet_ops_rwsem);
334	rtnl_lock();
335	err = __rtnl_link_register(&ifb_link_ops);
336	if (err < 0)
337		goto out;
338
339	for (i = 0; i < numifbs && !err; i++) {
340		err = ifb_init_one(i);
341		cond_resched();
342	}
343	if (err)
344		__rtnl_link_unregister(&ifb_link_ops);
345
346out:
347	rtnl_unlock();
348	up_write(&pernet_ops_rwsem);
349
350	return err;
351}
352
353static void __exit ifb_cleanup_module(void)
354{
355	rtnl_link_unregister(&ifb_link_ops);
356}
357
358module_init(ifb_init_module);
359module_exit(ifb_cleanup_module);
360MODULE_LICENSE("GPL");
361MODULE_AUTHOR("Jamal Hadi Salim");
362MODULE_ALIAS_RTNL_LINK("ifb");
v4.6
  1/* drivers/net/ifb.c:
  2
  3	The purpose of this driver is to provide a device that allows
  4	for sharing of resources:
  5
  6	1) qdiscs/policies that are per device as opposed to system wide.
  7	ifb allows for a device which can be redirected to thus providing
  8	an impression of sharing.
  9
 10	2) Allows for queueing incoming traffic for shaping instead of
 11	dropping.
 12
 13	The original concept is based on what is known as the IMQ
 14	driver initially written by Martin Devera, later rewritten
 15	by Patrick McHardy and then maintained by Andre Correa.
 16
 17	You need the tc action  mirror or redirect to feed this device
 18       	packets.
 19
 20	This program is free software; you can redistribute it and/or
 21	modify it under the terms of the GNU General Public License
 22	as published by the Free Software Foundation; either version
 23	2 of the License, or (at your option) any later version.
 24
 25  	Authors:	Jamal Hadi Salim (2005)
 26
 27*/
 28
 29
 30#include <linux/module.h>
 31#include <linux/kernel.h>
 32#include <linux/netdevice.h>
 33#include <linux/etherdevice.h>
 34#include <linux/init.h>
 35#include <linux/interrupt.h>
 36#include <linux/moduleparam.h>
 37#include <net/pkt_sched.h>
 38#include <net/net_namespace.h>
 39
 40#define TX_Q_LIMIT    32
 41struct ifb_q_private {
 42	struct net_device	*dev;
 43	struct tasklet_struct   ifb_tasklet;
 44	int			tasklet_pending;
 45	int			txqnum;
 46	struct sk_buff_head     rq;
 47	u64			rx_packets;
 48	u64			rx_bytes;
 49	struct u64_stats_sync	rsync;
 50
 51	struct u64_stats_sync	tsync;
 52	u64			tx_packets;
 53	u64			tx_bytes;
 54	struct sk_buff_head     tq;
 55} ____cacheline_aligned_in_smp;
 56
 57struct ifb_dev_private {
 58	struct ifb_q_private *tx_private;
 59};
 60
 61static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
 62static int ifb_open(struct net_device *dev);
 63static int ifb_close(struct net_device *dev);
 64
 65static void ifb_ri_tasklet(unsigned long _txp)
 66{
 67	struct ifb_q_private *txp = (struct ifb_q_private *)_txp;
 68	struct netdev_queue *txq;
 69	struct sk_buff *skb;
 70
 71	txq = netdev_get_tx_queue(txp->dev, txp->txqnum);
 72	skb = skb_peek(&txp->tq);
 73	if (!skb) {
 74		if (!__netif_tx_trylock(txq))
 75			goto resched;
 76		skb_queue_splice_tail_init(&txp->rq, &txp->tq);
 77		__netif_tx_unlock(txq);
 78	}
 79
 80	while ((skb = __skb_dequeue(&txp->tq)) != NULL) {
 81		u32 from = G_TC_FROM(skb->tc_verd);
 82
 83		skb->tc_verd = 0;
 84		skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
 85
 86		u64_stats_update_begin(&txp->tsync);
 87		txp->tx_packets++;
 88		txp->tx_bytes += skb->len;
 89		u64_stats_update_end(&txp->tsync);
 90
 91		rcu_read_lock();
 92		skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif);
 93		if (!skb->dev) {
 94			rcu_read_unlock();
 95			dev_kfree_skb(skb);
 96			txp->dev->stats.tx_dropped++;
 97			if (skb_queue_len(&txp->tq) != 0)
 98				goto resched;
 99			break;
100		}
101		rcu_read_unlock();
102		skb->skb_iif = txp->dev->ifindex;
103
104		if (from & AT_EGRESS) {
105			dev_queue_xmit(skb);
106		} else if (from & AT_INGRESS) {
107			skb_pull(skb, skb->mac_len);
108			netif_receive_skb(skb);
109		} else
110			BUG();
111	}
112
113	if (__netif_tx_trylock(txq)) {
114		skb = skb_peek(&txp->rq);
115		if (!skb) {
116			txp->tasklet_pending = 0;
117			if (netif_tx_queue_stopped(txq))
118				netif_tx_wake_queue(txq);
119		} else {
120			__netif_tx_unlock(txq);
121			goto resched;
122		}
123		__netif_tx_unlock(txq);
124	} else {
125resched:
126		txp->tasklet_pending = 1;
127		tasklet_schedule(&txp->ifb_tasklet);
128	}
129
130}
131
132static struct rtnl_link_stats64 *ifb_stats64(struct net_device *dev,
133					     struct rtnl_link_stats64 *stats)
134{
135	struct ifb_dev_private *dp = netdev_priv(dev);
136	struct ifb_q_private *txp = dp->tx_private;
137	unsigned int start;
138	u64 packets, bytes;
139	int i;
140
141	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
142		do {
143			start = u64_stats_fetch_begin_irq(&txp->rsync);
144			packets = txp->rx_packets;
145			bytes = txp->rx_bytes;
146		} while (u64_stats_fetch_retry_irq(&txp->rsync, start));
147		stats->rx_packets += packets;
148		stats->rx_bytes += bytes;
149
150		do {
151			start = u64_stats_fetch_begin_irq(&txp->tsync);
152			packets = txp->tx_packets;
153			bytes = txp->tx_bytes;
154		} while (u64_stats_fetch_retry_irq(&txp->tsync, start));
155		stats->tx_packets += packets;
156		stats->tx_bytes += bytes;
157	}
158	stats->rx_dropped = dev->stats.rx_dropped;
159	stats->tx_dropped = dev->stats.tx_dropped;
160
161	return stats;
162}
163
164static int ifb_dev_init(struct net_device *dev)
165{
166	struct ifb_dev_private *dp = netdev_priv(dev);
167	struct ifb_q_private *txp;
168	int i;
169
170	txp = kcalloc(dev->num_tx_queues, sizeof(*txp), GFP_KERNEL);
171	if (!txp)
172		return -ENOMEM;
173	dp->tx_private = txp;
174	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
175		txp->txqnum = i;
176		txp->dev = dev;
177		__skb_queue_head_init(&txp->rq);
178		__skb_queue_head_init(&txp->tq);
179		u64_stats_init(&txp->rsync);
180		u64_stats_init(&txp->tsync);
181		tasklet_init(&txp->ifb_tasklet, ifb_ri_tasklet,
182			     (unsigned long)txp);
183		netif_tx_start_queue(netdev_get_tx_queue(dev, i));
184	}
185	return 0;
186}
187
188static const struct net_device_ops ifb_netdev_ops = {
189	.ndo_open	= ifb_open,
190	.ndo_stop	= ifb_close,
191	.ndo_get_stats64 = ifb_stats64,
192	.ndo_start_xmit	= ifb_xmit,
193	.ndo_validate_addr = eth_validate_addr,
194	.ndo_init	= ifb_dev_init,
195};
196
197#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG  | NETIF_F_FRAGLIST	| \
198		      NETIF_F_TSO_ECN | NETIF_F_TSO | NETIF_F_TSO6	| \
 
199		      NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX		| \
200		      NETIF_F_HW_VLAN_STAG_TX)
201
202static void ifb_dev_free(struct net_device *dev)
203{
204	struct ifb_dev_private *dp = netdev_priv(dev);
205	struct ifb_q_private *txp = dp->tx_private;
206	int i;
207
208	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
209		tasklet_kill(&txp->ifb_tasklet);
210		__skb_queue_purge(&txp->rq);
211		__skb_queue_purge(&txp->tq);
212	}
213	kfree(dp->tx_private);
214	free_netdev(dev);
215}
216
217static void ifb_setup(struct net_device *dev)
218{
219	/* Initialize the device structure. */
220	dev->netdev_ops = &ifb_netdev_ops;
221
222	/* Fill in device structure with ethernet-generic values. */
223	ether_setup(dev);
224	dev->tx_queue_len = TX_Q_LIMIT;
225
226	dev->features |= IFB_FEATURES;
 
 
227	dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
228					       NETIF_F_HW_VLAN_STAG_TX);
229
230	dev->flags |= IFF_NOARP;
231	dev->flags &= ~IFF_MULTICAST;
232	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
233	netif_keep_dst(dev);
234	eth_hw_addr_random(dev);
235	dev->destructor = ifb_dev_free;
 
 
 
 
236}
237
238static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
239{
240	struct ifb_dev_private *dp = netdev_priv(dev);
241	u32 from = G_TC_FROM(skb->tc_verd);
242	struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
243
244	u64_stats_update_begin(&txp->rsync);
245	txp->rx_packets++;
246	txp->rx_bytes += skb->len;
247	u64_stats_update_end(&txp->rsync);
248
249	if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
250		dev_kfree_skb(skb);
251		dev->stats.rx_dropped++;
252		return NETDEV_TX_OK;
253	}
254
255	if (skb_queue_len(&txp->rq) >= dev->tx_queue_len)
256		netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum));
257
258	__skb_queue_tail(&txp->rq, skb);
259	if (!txp->tasklet_pending) {
260		txp->tasklet_pending = 1;
261		tasklet_schedule(&txp->ifb_tasklet);
262	}
263
264	return NETDEV_TX_OK;
265}
266
267static int ifb_close(struct net_device *dev)
268{
269	netif_tx_stop_all_queues(dev);
270	return 0;
271}
272
273static int ifb_open(struct net_device *dev)
274{
275	netif_tx_start_all_queues(dev);
276	return 0;
277}
278
279static int ifb_validate(struct nlattr *tb[], struct nlattr *data[])
 
280{
281	if (tb[IFLA_ADDRESS]) {
282		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
283			return -EINVAL;
284		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
285			return -EADDRNOTAVAIL;
286	}
287	return 0;
288}
289
290static struct rtnl_link_ops ifb_link_ops __read_mostly = {
291	.kind		= "ifb",
292	.priv_size	= sizeof(struct ifb_dev_private),
293	.setup		= ifb_setup,
294	.validate	= ifb_validate,
295};
296
297/* Number of ifb devices to be set up by this module.
298 * Note that these legacy devices have one queue.
299 * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb
300 */
301static int numifbs = 2;
302module_param(numifbs, int, 0);
303MODULE_PARM_DESC(numifbs, "Number of ifb devices");
304
305static int __init ifb_init_one(int index)
306{
307	struct net_device *dev_ifb;
308	int err;
309
310	dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d",
311			       NET_NAME_UNKNOWN, ifb_setup);
312
313	if (!dev_ifb)
314		return -ENOMEM;
315
316	dev_ifb->rtnl_link_ops = &ifb_link_ops;
317	err = register_netdevice(dev_ifb);
318	if (err < 0)
319		goto err;
320
321	return 0;
322
323err:
324	free_netdev(dev_ifb);
325	return err;
326}
327
328static int __init ifb_init_module(void)
329{
330	int i, err;
331
 
332	rtnl_lock();
333	err = __rtnl_link_register(&ifb_link_ops);
334	if (err < 0)
335		goto out;
336
337	for (i = 0; i < numifbs && !err; i++) {
338		err = ifb_init_one(i);
339		cond_resched();
340	}
341	if (err)
342		__rtnl_link_unregister(&ifb_link_ops);
343
344out:
345	rtnl_unlock();
 
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");