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v6.8
  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/ethtool.h>
 31#include <linux/etherdevice.h>
 32#include <linux/init.h>
 33#include <linux/interrupt.h>
 34#include <linux/moduleparam.h>
 35#include <linux/netfilter_netdev.h>
 36#include <net/pkt_sched.h>
 37#include <net/net_namespace.h>
 38
 39#define TX_Q_LIMIT    32
 40
 41struct ifb_q_stats {
 42	u64 packets;
 43	u64 bytes;
 44	struct u64_stats_sync	sync;
 45};
 46
 47struct ifb_q_private {
 48	struct net_device	*dev;
 49	struct tasklet_struct   ifb_tasklet;
 50	int			tasklet_pending;
 51	int			txqnum;
 52	struct sk_buff_head     rq;
 
 
 
 
 
 
 
 53	struct sk_buff_head     tq;
 54	struct ifb_q_stats	rx_stats;
 55	struct ifb_q_stats	tx_stats;
 56} ____cacheline_aligned_in_smp;
 57
 58struct ifb_dev_private {
 59	struct ifb_q_private *tx_private;
 60};
 61
 62/* For ethtools stats. */
 63struct ifb_q_stats_desc {
 64	char	desc[ETH_GSTRING_LEN];
 65	size_t	offset;
 66};
 67
 68#define IFB_Q_STAT(m)	offsetof(struct ifb_q_stats, m)
 69
 70static const struct ifb_q_stats_desc ifb_q_stats_desc[] = {
 71	{ "packets",	IFB_Q_STAT(packets) },
 72	{ "bytes",	IFB_Q_STAT(bytes) },
 73};
 74
 75#define IFB_Q_STATS_LEN	ARRAY_SIZE(ifb_q_stats_desc)
 76
 77static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
 78static int ifb_open(struct net_device *dev);
 79static int ifb_close(struct net_device *dev);
 80
 81static void ifb_update_q_stats(struct ifb_q_stats *stats, int len)
 82{
 83	u64_stats_update_begin(&stats->sync);
 84	stats->packets++;
 85	stats->bytes += len;
 86	u64_stats_update_end(&stats->sync);
 87}
 88
 89static void ifb_ri_tasklet(struct tasklet_struct *t)
 90{
 91	struct ifb_q_private *txp = from_tasklet(txp, t, ifb_tasklet);
 92	struct netdev_queue *txq;
 93	struct sk_buff *skb;
 94
 95	txq = netdev_get_tx_queue(txp->dev, txp->txqnum);
 96	skb = skb_peek(&txp->tq);
 97	if (!skb) {
 98		if (!__netif_tx_trylock(txq))
 99			goto resched;
100		skb_queue_splice_tail_init(&txp->rq, &txp->tq);
101		__netif_tx_unlock(txq);
102	}
103
104	while ((skb = __skb_dequeue(&txp->tq)) != NULL) {
105		/* Skip tc and netfilter to prevent redirection loop. */
106		skb->redirected = 0;
107#ifdef CONFIG_NET_CLS_ACT
108		skb->tc_skip_classify = 1;
109#endif
110		nf_skip_egress(skb, true);
111
112		ifb_update_q_stats(&txp->tx_stats, skb->len);
 
 
 
113
114		rcu_read_lock();
115		skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif);
116		if (!skb->dev) {
117			rcu_read_unlock();
118			dev_kfree_skb(skb);
119			txp->dev->stats.tx_dropped++;
120			if (skb_queue_len(&txp->tq) != 0)
121				goto resched;
122			break;
123		}
124		rcu_read_unlock();
125		skb->skb_iif = txp->dev->ifindex;
126
127		if (!skb->from_ingress) {
128			dev_queue_xmit(skb);
129		} else {
130			skb_pull_rcsum(skb, skb->mac_len);
131			netif_receive_skb(skb);
132		}
133	}
134
135	if (__netif_tx_trylock(txq)) {
136		skb = skb_peek(&txp->rq);
137		if (!skb) {
138			txp->tasklet_pending = 0;
139			if (netif_tx_queue_stopped(txq))
140				netif_tx_wake_queue(txq);
141		} else {
142			__netif_tx_unlock(txq);
143			goto resched;
144		}
145		__netif_tx_unlock(txq);
146	} else {
147resched:
148		txp->tasklet_pending = 1;
149		tasklet_schedule(&txp->ifb_tasklet);
150	}
151
152}
153
154static void ifb_stats64(struct net_device *dev,
155			struct rtnl_link_stats64 *stats)
156{
157	struct ifb_dev_private *dp = netdev_priv(dev);
158	struct ifb_q_private *txp = dp->tx_private;
159	unsigned int start;
160	u64 packets, bytes;
161	int i;
162
163	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
164		do {
165			start = u64_stats_fetch_begin(&txp->rx_stats.sync);
166			packets = txp->rx_stats.packets;
167			bytes = txp->rx_stats.bytes;
168		} while (u64_stats_fetch_retry(&txp->rx_stats.sync, start));
169		stats->rx_packets += packets;
170		stats->rx_bytes += bytes;
171
172		do {
173			start = u64_stats_fetch_begin(&txp->tx_stats.sync);
174			packets = txp->tx_stats.packets;
175			bytes = txp->tx_stats.bytes;
176		} while (u64_stats_fetch_retry(&txp->tx_stats.sync, start));
177		stats->tx_packets += packets;
178		stats->tx_bytes += bytes;
179	}
180	stats->rx_dropped = dev->stats.rx_dropped;
181	stats->tx_dropped = dev->stats.tx_dropped;
182}
183
184static int ifb_dev_init(struct net_device *dev)
185{
186	struct ifb_dev_private *dp = netdev_priv(dev);
187	struct ifb_q_private *txp;
188	int i;
189
190	txp = kcalloc(dev->num_tx_queues, sizeof(*txp), GFP_KERNEL);
191	if (!txp)
192		return -ENOMEM;
193	dp->tx_private = txp;
194	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
195		txp->txqnum = i;
196		txp->dev = dev;
197		__skb_queue_head_init(&txp->rq);
198		__skb_queue_head_init(&txp->tq);
199		u64_stats_init(&txp->rx_stats.sync);
200		u64_stats_init(&txp->tx_stats.sync);
201		tasklet_setup(&txp->ifb_tasklet, ifb_ri_tasklet);
 
202		netif_tx_start_queue(netdev_get_tx_queue(dev, i));
203	}
204	return 0;
205}
206
207static void ifb_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
208{
209	u8 *p = buf;
210	int i, j;
211
212	switch (stringset) {
213	case ETH_SS_STATS:
214		for (i = 0; i < dev->real_num_rx_queues; i++)
215			for (j = 0; j < IFB_Q_STATS_LEN; j++)
216				ethtool_sprintf(&p, "rx_queue_%u_%.18s",
217						i, ifb_q_stats_desc[j].desc);
218
219		for (i = 0; i < dev->real_num_tx_queues; i++)
220			for (j = 0; j < IFB_Q_STATS_LEN; j++)
221				ethtool_sprintf(&p, "tx_queue_%u_%.18s",
222						i, ifb_q_stats_desc[j].desc);
223
224		break;
225	}
226}
227
228static int ifb_get_sset_count(struct net_device *dev, int sset)
229{
230	switch (sset) {
231	case ETH_SS_STATS:
232		return IFB_Q_STATS_LEN * (dev->real_num_rx_queues +
233					  dev->real_num_tx_queues);
234	default:
235		return -EOPNOTSUPP;
236	}
237}
238
239static void ifb_fill_stats_data(u64 **data,
240				struct ifb_q_stats *q_stats)
241{
242	void *stats_base = (void *)q_stats;
243	unsigned int start;
244	size_t offset;
245	int j;
246
247	do {
248		start = u64_stats_fetch_begin(&q_stats->sync);
249		for (j = 0; j < IFB_Q_STATS_LEN; j++) {
250			offset = ifb_q_stats_desc[j].offset;
251			(*data)[j] = *(u64 *)(stats_base + offset);
252		}
253	} while (u64_stats_fetch_retry(&q_stats->sync, start));
254
255	*data += IFB_Q_STATS_LEN;
256}
257
258static void ifb_get_ethtool_stats(struct net_device *dev,
259				  struct ethtool_stats *stats, u64 *data)
260{
261	struct ifb_dev_private *dp = netdev_priv(dev);
262	struct ifb_q_private *txp;
263	int i;
264
265	for (i = 0; i < dev->real_num_rx_queues; i++) {
266		txp = dp->tx_private + i;
267		ifb_fill_stats_data(&data, &txp->rx_stats);
268	}
269
270	for (i = 0; i < dev->real_num_tx_queues; i++) {
271		txp = dp->tx_private + i;
272		ifb_fill_stats_data(&data, &txp->tx_stats);
273	}
274}
275
276static const struct net_device_ops ifb_netdev_ops = {
277	.ndo_open	= ifb_open,
278	.ndo_stop	= ifb_close,
279	.ndo_get_stats64 = ifb_stats64,
280	.ndo_start_xmit	= ifb_xmit,
281	.ndo_validate_addr = eth_validate_addr,
282	.ndo_init	= ifb_dev_init,
283};
284
285static const struct ethtool_ops ifb_ethtool_ops = {
286	.get_strings		= ifb_get_strings,
287	.get_sset_count		= ifb_get_sset_count,
288	.get_ethtool_stats	= ifb_get_ethtool_stats,
289};
290
291#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG  | NETIF_F_FRAGLIST	| \
292		      NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL	| \
 
293		      NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX		| \
294		      NETIF_F_HW_VLAN_STAG_TX)
295
296static void ifb_dev_free(struct net_device *dev)
297{
298	struct ifb_dev_private *dp = netdev_priv(dev);
299	struct ifb_q_private *txp = dp->tx_private;
300	int i;
301
302	for (i = 0; i < dev->num_tx_queues; i++,txp++) {
303		tasklet_kill(&txp->ifb_tasklet);
304		__skb_queue_purge(&txp->rq);
305		__skb_queue_purge(&txp->tq);
306	}
307	kfree(dp->tx_private);
308}
309
310static void ifb_setup(struct net_device *dev)
311{
312	/* Initialize the device structure. */
313	dev->netdev_ops = &ifb_netdev_ops;
314	dev->ethtool_ops = &ifb_ethtool_ops;
315
316	/* Fill in device structure with ethernet-generic values. */
317	ether_setup(dev);
318	dev->tx_queue_len = TX_Q_LIMIT;
319
320	dev->features |= IFB_FEATURES;
321	dev->hw_features |= dev->features;
322	dev->hw_enc_features |= dev->features;
323	dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
324					       NETIF_F_HW_VLAN_STAG_TX);
325
326	dev->flags |= IFF_NOARP;
327	dev->flags &= ~IFF_MULTICAST;
328	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
329	netif_keep_dst(dev);
330	eth_hw_addr_random(dev);
331	dev->needs_free_netdev = true;
332	dev->priv_destructor = ifb_dev_free;
333
334	dev->min_mtu = 0;
335	dev->max_mtu = 0;
336}
337
338static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
339{
340	struct ifb_dev_private *dp = netdev_priv(dev);
341	struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
342
343	ifb_update_q_stats(&txp->rx_stats, skb->len);
 
 
 
344
345	if (!skb->redirected || !skb->skb_iif) {
346		dev_kfree_skb(skb);
347		dev->stats.rx_dropped++;
348		return NETDEV_TX_OK;
349	}
350
351	if (skb_queue_len(&txp->rq) >= dev->tx_queue_len)
352		netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum));
353
354	__skb_queue_tail(&txp->rq, skb);
355	if (!txp->tasklet_pending) {
356		txp->tasklet_pending = 1;
357		tasklet_schedule(&txp->ifb_tasklet);
358	}
359
360	return NETDEV_TX_OK;
361}
362
363static int ifb_close(struct net_device *dev)
364{
365	netif_tx_stop_all_queues(dev);
366	return 0;
367}
368
369static int ifb_open(struct net_device *dev)
370{
371	netif_tx_start_all_queues(dev);
372	return 0;
373}
374
375static int ifb_validate(struct nlattr *tb[], struct nlattr *data[],
376			struct netlink_ext_ack *extack)
377{
378	if (tb[IFLA_ADDRESS]) {
379		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
380			return -EINVAL;
381		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
382			return -EADDRNOTAVAIL;
383	}
384	return 0;
385}
386
387static struct rtnl_link_ops ifb_link_ops __read_mostly = {
388	.kind		= "ifb",
389	.priv_size	= sizeof(struct ifb_dev_private),
390	.setup		= ifb_setup,
391	.validate	= ifb_validate,
392};
393
394/* Number of ifb devices to be set up by this module.
395 * Note that these legacy devices have one queue.
396 * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb
397 */
398static int numifbs = 2;
399module_param(numifbs, int, 0);
400MODULE_PARM_DESC(numifbs, "Number of ifb devices");
401
402static int __init ifb_init_one(int index)
403{
404	struct net_device *dev_ifb;
405	int err;
406
407	dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d",
408			       NET_NAME_UNKNOWN, ifb_setup);
409
410	if (!dev_ifb)
411		return -ENOMEM;
412
413	dev_ifb->rtnl_link_ops = &ifb_link_ops;
414	err = register_netdevice(dev_ifb);
415	if (err < 0)
416		goto err;
417
418	return 0;
419
420err:
421	free_netdev(dev_ifb);
422	return err;
423}
424
425static int __init ifb_init_module(void)
426{
427	int i, err;
428
429	down_write(&pernet_ops_rwsem);
430	rtnl_lock();
431	err = __rtnl_link_register(&ifb_link_ops);
432	if (err < 0)
433		goto out;
434
435	for (i = 0; i < numifbs && !err; i++) {
436		err = ifb_init_one(i);
437		cond_resched();
438	}
439	if (err)
440		__rtnl_link_unregister(&ifb_link_ops);
441
442out:
443	rtnl_unlock();
444	up_write(&pernet_ops_rwsem);
445
446	return err;
447}
448
449static void __exit ifb_cleanup_module(void)
450{
451	rtnl_link_unregister(&ifb_link_ops);
452}
453
454module_init(ifb_init_module);
455module_exit(ifb_cleanup_module);
456MODULE_LICENSE("GPL");
457MODULE_DESCRIPTION("Intermediate Functional Block (ifb) netdevice driver for sharing of resources and ingress packet queuing");
458MODULE_AUTHOR("Jamal Hadi Salim");
459MODULE_ALIAS_RTNL_LINK("ifb");
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");