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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");
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");