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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 | |
41 | struct 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 | ||
57 | struct ifb_dev_private { | |
58 | struct ifb_q_private *tx_private; | |
59 | }; | |
60 | ||
61 | static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev); | |
62 | static int ifb_open(struct net_device *dev); | |
63 | static int ifb_close(struct net_device *dev); | |
64 | ||
65 | static 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 { | |
122 | resched: | |
123 | txp->tasklet_pending = 1; | |
124 | tasklet_schedule(&txp->ifb_tasklet); | |
125 | } | |
126 | ||
127 | } | |
128 | ||
129 | static 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 | ||
159 | static 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 | ||
183 | static 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 | ||
198 | static 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 | free_netdev(dev); | |
211 | } | |
212 | ||
213 | static void ifb_setup(struct net_device *dev) | |
214 | { | |
215 | /* Initialize the device structure. */ | |
216 | dev->netdev_ops = &ifb_netdev_ops; | |
217 | ||
218 | /* Fill in device structure with ethernet-generic values. */ | |
219 | ether_setup(dev); | |
220 | dev->tx_queue_len = TX_Q_LIMIT; | |
221 | ||
222 | dev->features |= IFB_FEATURES; | |
223 | dev->hw_features |= dev->features; | |
224 | dev->hw_enc_features |= dev->features; | |
225 | dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX | | |
226 | NETIF_F_HW_VLAN_STAG_TX); | |
227 | ||
228 | dev->flags |= IFF_NOARP; | |
229 | dev->flags &= ~IFF_MULTICAST; | |
230 | dev->priv_flags &= ~IFF_TX_SKB_SHARING; | |
231 | netif_keep_dst(dev); | |
232 | eth_hw_addr_random(dev); | |
233 | dev->destructor = ifb_dev_free; | |
234 | } | |
235 | ||
236 | static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev) | |
237 | { | |
238 | struct ifb_dev_private *dp = netdev_priv(dev); | |
239 | struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb); | |
240 | ||
241 | u64_stats_update_begin(&txp->rsync); | |
242 | txp->rx_packets++; | |
243 | txp->rx_bytes += skb->len; | |
244 | u64_stats_update_end(&txp->rsync); | |
245 | ||
246 | if (!skb->tc_redirected || !skb->skb_iif) { | |
247 | dev_kfree_skb(skb); | |
248 | dev->stats.rx_dropped++; | |
249 | return NETDEV_TX_OK; | |
250 | } | |
251 | ||
252 | if (skb_queue_len(&txp->rq) >= dev->tx_queue_len) | |
253 | netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum)); | |
254 | ||
255 | __skb_queue_tail(&txp->rq, skb); | |
256 | if (!txp->tasklet_pending) { | |
257 | txp->tasklet_pending = 1; | |
258 | tasklet_schedule(&txp->ifb_tasklet); | |
259 | } | |
260 | ||
261 | return NETDEV_TX_OK; | |
262 | } | |
263 | ||
264 | static int ifb_close(struct net_device *dev) | |
265 | { | |
266 | netif_tx_stop_all_queues(dev); | |
267 | return 0; | |
268 | } | |
269 | ||
270 | static int ifb_open(struct net_device *dev) | |
271 | { | |
272 | netif_tx_start_all_queues(dev); | |
273 | return 0; | |
274 | } | |
275 | ||
276 | static int ifb_validate(struct nlattr *tb[], struct nlattr *data[]) | |
277 | { | |
278 | if (tb[IFLA_ADDRESS]) { | |
279 | if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) | |
280 | return -EINVAL; | |
281 | if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) | |
282 | return -EADDRNOTAVAIL; | |
283 | } | |
284 | return 0; | |
285 | } | |
286 | ||
287 | static struct rtnl_link_ops ifb_link_ops __read_mostly = { | |
288 | .kind = "ifb", | |
289 | .priv_size = sizeof(struct ifb_dev_private), | |
290 | .setup = ifb_setup, | |
291 | .validate = ifb_validate, | |
292 | }; | |
293 | ||
294 | /* Number of ifb devices to be set up by this module. | |
295 | * Note that these legacy devices have one queue. | |
296 | * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb | |
297 | */ | |
298 | static int numifbs = 2; | |
299 | module_param(numifbs, int, 0); | |
300 | MODULE_PARM_DESC(numifbs, "Number of ifb devices"); | |
301 | ||
302 | static int __init ifb_init_one(int index) | |
303 | { | |
304 | struct net_device *dev_ifb; | |
305 | int err; | |
306 | ||
307 | dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d", | |
308 | NET_NAME_UNKNOWN, ifb_setup); | |
309 | ||
310 | if (!dev_ifb) | |
311 | return -ENOMEM; | |
312 | ||
313 | dev_ifb->rtnl_link_ops = &ifb_link_ops; | |
314 | err = register_netdevice(dev_ifb); | |
315 | if (err < 0) | |
316 | goto err; | |
317 | ||
318 | return 0; | |
319 | ||
320 | err: | |
321 | free_netdev(dev_ifb); | |
322 | return err; | |
323 | } | |
324 | ||
325 | static int __init ifb_init_module(void) | |
326 | { | |
327 | int i, err; | |
328 | ||
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 | ||
341 | out: | |
342 | rtnl_unlock(); | |
343 | ||
344 | return err; | |
345 | } | |
346 | ||
347 | static void __exit ifb_cleanup_module(void) | |
348 | { | |
349 | rtnl_link_unregister(&ifb_link_ops); | |
350 | } | |
351 | ||
352 | module_init(ifb_init_module); | |
353 | module_exit(ifb_cleanup_module); | |
354 | MODULE_LICENSE("GPL"); | |
355 | MODULE_AUTHOR("Jamal Hadi Salim"); | |
356 | MODULE_ALIAS_RTNL_LINK("ifb"); |