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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");
v3.15
 
  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_private {
 
 
 
 
 
 
 
 
 42	struct tasklet_struct   ifb_tasklet;
 43	int     tasklet_pending;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 44
 45	struct u64_stats_sync	rsync;
 46	struct sk_buff_head     rq;
 47	u64 rx_packets;
 48	u64 rx_bytes;
 49
 50	struct u64_stats_sync	tsync;
 51	struct sk_buff_head     tq;
 52	u64 tx_packets;
 53	u64 tx_bytes;
 54};
 55
 56static int numifbs = 2;
 57
 58static void ri_tasklet(unsigned long dev);
 59static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
 60static int ifb_open(struct net_device *dev);
 61static int ifb_close(struct net_device *dev);
 62
 63static void ri_tasklet(unsigned long dev)
 
 
 
 
 
 
 
 
 64{
 65	struct net_device *_dev = (struct net_device *)dev;
 66	struct ifb_private *dp = netdev_priv(_dev);
 67	struct netdev_queue *txq;
 68	struct sk_buff *skb;
 69
 70	txq = netdev_get_tx_queue(_dev, 0);
 71	if ((skb = skb_peek(&dp->tq)) == NULL) {
 72		if (__netif_tx_trylock(txq)) {
 73			skb_queue_splice_tail_init(&dp->rq, &dp->tq);
 74			__netif_tx_unlock(txq);
 75		} else {
 76			/* reschedule */
 77			goto resched;
 78		}
 
 79	}
 80
 81	while ((skb = __skb_dequeue(&dp->tq)) != NULL) {
 82		u32 from = G_TC_FROM(skb->tc_verd);
 83
 84		skb->tc_verd = 0;
 85		skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
 
 
 86
 87		u64_stats_update_begin(&dp->tsync);
 88		dp->tx_packets++;
 89		dp->tx_bytes += skb->len;
 90		u64_stats_update_end(&dp->tsync);
 91
 92		rcu_read_lock();
 93		skb->dev = dev_get_by_index_rcu(dev_net(_dev), skb->skb_iif);
 94		if (!skb->dev) {
 95			rcu_read_unlock();
 96			dev_kfree_skb(skb);
 97			_dev->stats.tx_dropped++;
 98			if (skb_queue_len(&dp->tq) != 0)
 99				goto resched;
100			break;
101		}
102		rcu_read_unlock();
103		skb->skb_iif = _dev->ifindex;
104
105		if (from & AT_EGRESS) {
106			dev_queue_xmit(skb);
107		} else if (from & AT_INGRESS) {
108			skb_pull(skb, skb->dev->hard_header_len);
109			netif_receive_skb(skb);
110		} else
111			BUG();
112	}
113
114	if (__netif_tx_trylock(txq)) {
115		if ((skb = skb_peek(&dp->rq)) == NULL) {
116			dp->tasklet_pending = 0;
117			if (netif_queue_stopped(_dev))
118				netif_wake_queue(_dev);
 
119		} else {
120			__netif_tx_unlock(txq);
121			goto resched;
122		}
123		__netif_tx_unlock(txq);
124	} else {
125resched:
126		dp->tasklet_pending = 1;
127		tasklet_schedule(&dp->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_private *dp = netdev_priv(dev);
 
136	unsigned int start;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
137
138	do {
139		start = u64_stats_fetch_begin_irq(&dp->rsync);
140		stats->rx_packets = dp->rx_packets;
141		stats->rx_bytes = dp->rx_bytes;
142	} while (u64_stats_fetch_retry_irq(&dp->rsync, start));
143
144	do {
145		start = u64_stats_fetch_begin_irq(&dp->tsync);
 
 
 
 
 
 
 
 
 
146
147		stats->tx_packets = dp->tx_packets;
148		stats->tx_bytes = dp->tx_bytes;
 
149
150	} while (u64_stats_fetch_retry_irq(&dp->tsync, start));
 
 
 
 
 
 
 
 
 
151
152	stats->rx_dropped = dev->stats.rx_dropped;
153	stats->tx_dropped = dev->stats.tx_dropped;
 
 
 
 
 
 
 
 
 
 
 
 
 
154
155	return stats;
156}
157
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
158
159static const struct net_device_ops ifb_netdev_ops = {
160	.ndo_open	= ifb_open,
161	.ndo_stop	= ifb_close,
162	.ndo_get_stats64 = ifb_stats64,
163	.ndo_start_xmit	= ifb_xmit,
164	.ndo_validate_addr = eth_validate_addr,
 
 
 
 
 
 
 
165};
166
167#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG  | NETIF_F_FRAGLIST	| \
168		      NETIF_F_TSO_ECN | NETIF_F_TSO | NETIF_F_TSO6	| \
169		      NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX		| \
170		      NETIF_F_HW_VLAN_STAG_TX)
171
 
 
 
 
 
 
 
 
 
 
 
 
 
 
172static void ifb_setup(struct net_device *dev)
173{
174	/* Initialize the device structure. */
175	dev->destructor = free_netdev;
176	dev->netdev_ops = &ifb_netdev_ops;
 
177
178	/* Fill in device structure with ethernet-generic values. */
179	ether_setup(dev);
180	dev->tx_queue_len = TX_Q_LIMIT;
181
182	dev->features |= IFB_FEATURES;
 
 
183	dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
184					       NETIF_F_HW_VLAN_STAG_TX);
185
186	dev->flags |= IFF_NOARP;
187	dev->flags &= ~IFF_MULTICAST;
188	dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING);
 
189	eth_hw_addr_random(dev);
 
 
 
 
 
190}
191
192static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
193{
194	struct ifb_private *dp = netdev_priv(dev);
195	u32 from = G_TC_FROM(skb->tc_verd);
196
197	u64_stats_update_begin(&dp->rsync);
198	dp->rx_packets++;
199	dp->rx_bytes += skb->len;
200	u64_stats_update_end(&dp->rsync);
201
202	if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
203		dev_kfree_skb(skb);
204		dev->stats.rx_dropped++;
205		return NETDEV_TX_OK;
206	}
207
208	if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
209		netif_stop_queue(dev);
210	}
211
212	__skb_queue_tail(&dp->rq, skb);
213	if (!dp->tasklet_pending) {
214		dp->tasklet_pending = 1;
215		tasklet_schedule(&dp->ifb_tasklet);
216	}
217
218	return NETDEV_TX_OK;
219}
220
221static int ifb_close(struct net_device *dev)
222{
223	struct ifb_private *dp = netdev_priv(dev);
224
225	tasklet_kill(&dp->ifb_tasklet);
226	netif_stop_queue(dev);
227	__skb_queue_purge(&dp->rq);
228	__skb_queue_purge(&dp->tq);
229	return 0;
230}
231
232static int ifb_open(struct net_device *dev)
233{
234	struct ifb_private *dp = netdev_priv(dev);
235
236	tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev);
237	__skb_queue_head_init(&dp->rq);
238	__skb_queue_head_init(&dp->tq);
239	netif_start_queue(dev);
240
241	return 0;
242}
243
244static int ifb_validate(struct nlattr *tb[], struct nlattr *data[])
 
245{
246	if (tb[IFLA_ADDRESS]) {
247		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
248			return -EINVAL;
249		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
250			return -EADDRNOTAVAIL;
251	}
252	return 0;
253}
254
255static struct rtnl_link_ops ifb_link_ops __read_mostly = {
256	.kind		= "ifb",
257	.priv_size	= sizeof(struct ifb_private),
258	.setup		= ifb_setup,
259	.validate	= ifb_validate,
260};
261
262/* Number of ifb devices to be set up by this module. */
 
 
 
 
263module_param(numifbs, int, 0);
264MODULE_PARM_DESC(numifbs, "Number of ifb devices");
265
266static int __init ifb_init_one(int index)
267{
268	struct net_device *dev_ifb;
269	struct ifb_private *dp;
270	int err;
271
272	dev_ifb = alloc_netdev(sizeof(struct ifb_private),
273				 "ifb%d", ifb_setup);
274
275	if (!dev_ifb)
276		return -ENOMEM;
277
278	dp = netdev_priv(dev_ifb);
279	u64_stats_init(&dp->rsync);
280	u64_stats_init(&dp->tsync);
281
282	dev_ifb->rtnl_link_ops = &ifb_link_ops;
283	err = register_netdevice(dev_ifb);
284	if (err < 0)
285		goto err;
286
287	return 0;
288
289err:
290	free_netdev(dev_ifb);
291	return err;
292}
293
294static int __init ifb_init_module(void)
295{
296	int i, err;
297
 
298	rtnl_lock();
299	err = __rtnl_link_register(&ifb_link_ops);
300	if (err < 0)
301		goto out;
302
303	for (i = 0; i < numifbs && !err; i++) {
304		err = ifb_init_one(i);
305		cond_resched();
306	}
307	if (err)
308		__rtnl_link_unregister(&ifb_link_ops);
309
310out:
311	rtnl_unlock();
 
312
313	return err;
314}
315
316static void __exit ifb_cleanup_module(void)
317{
318	rtnl_link_unregister(&ifb_link_ops);
319}
320
321module_init(ifb_init_module);
322module_exit(ifb_cleanup_module);
323MODULE_LICENSE("GPL");
 
324MODULE_AUTHOR("Jamal Hadi Salim");
325MODULE_ALIAS_RTNL_LINK("ifb");