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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(&init_net, 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_bh(&dp->rsync);
140 stats->rx_packets = dp->rx_packets;
141 stats->rx_bytes = dp->rx_bytes;
142 } while (u64_stats_fetch_retry_bh(&dp->rsync, start));
143
144 do {
145 start = u64_stats_fetch_begin_bh(&dp->tsync);
146
147 stats->tx_packets = dp->tx_packets;
148 stats->tx_bytes = dp->tx_bytes;
149
150 } while (u64_stats_fetch_retry_bh(&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_NO_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_TX)
170
171static void ifb_setup(struct net_device *dev)
172{
173 /* Initialize the device structure. */
174 dev->destructor = free_netdev;
175 dev->netdev_ops = &ifb_netdev_ops;
176
177 /* Fill in device structure with ethernet-generic values. */
178 ether_setup(dev);
179 dev->tx_queue_len = TX_Q_LIMIT;
180
181 dev->features |= IFB_FEATURES;
182 dev->vlan_features |= IFB_FEATURES;
183
184 dev->flags |= IFF_NOARP;
185 dev->flags &= ~IFF_MULTICAST;
186 dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING);
187 random_ether_addr(dev->dev_addr);
188}
189
190static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
191{
192 struct ifb_private *dp = netdev_priv(dev);
193 u32 from = G_TC_FROM(skb->tc_verd);
194
195 u64_stats_update_begin(&dp->rsync);
196 dp->rx_packets++;
197 dp->rx_bytes += skb->len;
198 u64_stats_update_end(&dp->rsync);
199
200 if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
201 dev_kfree_skb(skb);
202 dev->stats.rx_dropped++;
203 return NETDEV_TX_OK;
204 }
205
206 if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
207 netif_stop_queue(dev);
208 }
209
210 __skb_queue_tail(&dp->rq, skb);
211 if (!dp->tasklet_pending) {
212 dp->tasklet_pending = 1;
213 tasklet_schedule(&dp->ifb_tasklet);
214 }
215
216 return NETDEV_TX_OK;
217}
218
219static int ifb_close(struct net_device *dev)
220{
221 struct ifb_private *dp = netdev_priv(dev);
222
223 tasklet_kill(&dp->ifb_tasklet);
224 netif_stop_queue(dev);
225 __skb_queue_purge(&dp->rq);
226 __skb_queue_purge(&dp->tq);
227 return 0;
228}
229
230static int ifb_open(struct net_device *dev)
231{
232 struct ifb_private *dp = netdev_priv(dev);
233
234 tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev);
235 __skb_queue_head_init(&dp->rq);
236 __skb_queue_head_init(&dp->tq);
237 netif_start_queue(dev);
238
239 return 0;
240}
241
242static int ifb_validate(struct nlattr *tb[], struct nlattr *data[])
243{
244 if (tb[IFLA_ADDRESS]) {
245 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
246 return -EINVAL;
247 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
248 return -EADDRNOTAVAIL;
249 }
250 return 0;
251}
252
253static struct rtnl_link_ops ifb_link_ops __read_mostly = {
254 .kind = "ifb",
255 .priv_size = sizeof(struct ifb_private),
256 .setup = ifb_setup,
257 .validate = ifb_validate,
258};
259
260/* Number of ifb devices to be set up by this module. */
261module_param(numifbs, int, 0);
262MODULE_PARM_DESC(numifbs, "Number of ifb devices");
263
264static int __init ifb_init_one(int index)
265{
266 struct net_device *dev_ifb;
267 int err;
268
269 dev_ifb = alloc_netdev(sizeof(struct ifb_private),
270 "ifb%d", ifb_setup);
271
272 if (!dev_ifb)
273 return -ENOMEM;
274
275 dev_ifb->rtnl_link_ops = &ifb_link_ops;
276 err = register_netdevice(dev_ifb);
277 if (err < 0)
278 goto err;
279
280 return 0;
281
282err:
283 free_netdev(dev_ifb);
284 return err;
285}
286
287static int __init ifb_init_module(void)
288{
289 int i, err;
290
291 rtnl_lock();
292 err = __rtnl_link_register(&ifb_link_ops);
293
294 for (i = 0; i < numifbs && !err; i++)
295 err = ifb_init_one(i);
296 if (err)
297 __rtnl_link_unregister(&ifb_link_ops);
298 rtnl_unlock();
299
300 return err;
301}
302
303static void __exit ifb_cleanup_module(void)
304{
305 rtnl_link_unregister(&ifb_link_ops);
306}
307
308module_init(ifb_init_module);
309module_exit(ifb_cleanup_module);
310MODULE_LICENSE("GPL");
311MODULE_AUTHOR("Jamal Hadi Salim");
312MODULE_ALIAS_RTNL_LINK("ifb");
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_GSO_ENCAP_ALL | \
200 NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX | \
201 NETIF_F_HW_VLAN_STAG_TX)
202
203static void ifb_dev_free(struct net_device *dev)
204{
205 struct ifb_dev_private *dp = netdev_priv(dev);
206 struct ifb_q_private *txp = dp->tx_private;
207 int i;
208
209 for (i = 0; i < dev->num_tx_queues; i++,txp++) {
210 tasklet_kill(&txp->ifb_tasklet);
211 __skb_queue_purge(&txp->rq);
212 __skb_queue_purge(&txp->tq);
213 }
214 kfree(dp->tx_private);
215 free_netdev(dev);
216}
217
218static void ifb_setup(struct net_device *dev)
219{
220 /* Initialize the device structure. */
221 dev->netdev_ops = &ifb_netdev_ops;
222
223 /* Fill in device structure with ethernet-generic values. */
224 ether_setup(dev);
225 dev->tx_queue_len = TX_Q_LIMIT;
226
227 dev->features |= IFB_FEATURES;
228 dev->hw_features |= dev->features;
229 dev->hw_enc_features |= dev->features;
230 dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
231 NETIF_F_HW_VLAN_STAG_TX);
232
233 dev->flags |= IFF_NOARP;
234 dev->flags &= ~IFF_MULTICAST;
235 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
236 netif_keep_dst(dev);
237 eth_hw_addr_random(dev);
238 dev->destructor = ifb_dev_free;
239}
240
241static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
242{
243 struct ifb_dev_private *dp = netdev_priv(dev);
244 u32 from = G_TC_FROM(skb->tc_verd);
245 struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
246
247 u64_stats_update_begin(&txp->rsync);
248 txp->rx_packets++;
249 txp->rx_bytes += skb->len;
250 u64_stats_update_end(&txp->rsync);
251
252 if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
253 dev_kfree_skb(skb);
254 dev->stats.rx_dropped++;
255 return NETDEV_TX_OK;
256 }
257
258 if (skb_queue_len(&txp->rq) >= dev->tx_queue_len)
259 netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum));
260
261 __skb_queue_tail(&txp->rq, skb);
262 if (!txp->tasklet_pending) {
263 txp->tasklet_pending = 1;
264 tasklet_schedule(&txp->ifb_tasklet);
265 }
266
267 return NETDEV_TX_OK;
268}
269
270static int ifb_close(struct net_device *dev)
271{
272 netif_tx_stop_all_queues(dev);
273 return 0;
274}
275
276static int ifb_open(struct net_device *dev)
277{
278 netif_tx_start_all_queues(dev);
279 return 0;
280}
281
282static int ifb_validate(struct nlattr *tb[], struct nlattr *data[])
283{
284 if (tb[IFLA_ADDRESS]) {
285 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
286 return -EINVAL;
287 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
288 return -EADDRNOTAVAIL;
289 }
290 return 0;
291}
292
293static struct rtnl_link_ops ifb_link_ops __read_mostly = {
294 .kind = "ifb",
295 .priv_size = sizeof(struct ifb_dev_private),
296 .setup = ifb_setup,
297 .validate = ifb_validate,
298};
299
300/* Number of ifb devices to be set up by this module.
301 * Note that these legacy devices have one queue.
302 * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb
303 */
304static int numifbs = 2;
305module_param(numifbs, int, 0);
306MODULE_PARM_DESC(numifbs, "Number of ifb devices");
307
308static int __init ifb_init_one(int index)
309{
310 struct net_device *dev_ifb;
311 int err;
312
313 dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d",
314 NET_NAME_UNKNOWN, ifb_setup);
315
316 if (!dev_ifb)
317 return -ENOMEM;
318
319 dev_ifb->rtnl_link_ops = &ifb_link_ops;
320 err = register_netdevice(dev_ifb);
321 if (err < 0)
322 goto err;
323
324 return 0;
325
326err:
327 free_netdev(dev_ifb);
328 return err;
329}
330
331static int __init ifb_init_module(void)
332{
333 int i, err;
334
335 rtnl_lock();
336 err = __rtnl_link_register(&ifb_link_ops);
337 if (err < 0)
338 goto out;
339
340 for (i = 0; i < numifbs && !err; i++) {
341 err = ifb_init_one(i);
342 cond_resched();
343 }
344 if (err)
345 __rtnl_link_unregister(&ifb_link_ops);
346
347out:
348 rtnl_unlock();
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");