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253af423 JHS |
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/config.h> | |
31 | #include <linux/module.h> | |
32 | #include <linux/kernel.h> | |
33 | #include <linux/netdevice.h> | |
34 | #include <linux/etherdevice.h> | |
35 | #include <linux/init.h> | |
36 | #include <linux/moduleparam.h> | |
37 | #include <net/pkt_sched.h> | |
38 | ||
39 | #define TX_TIMEOUT (2*HZ) | |
40 | ||
41 | #define TX_Q_LIMIT 32 | |
42 | struct ifb_private { | |
43 | struct net_device_stats stats; | |
44 | struct tasklet_struct ifb_tasklet; | |
45 | int tasklet_pending; | |
46 | /* mostly debug stats leave in for now */ | |
47 | unsigned long st_task_enter; /* tasklet entered */ | |
48 | unsigned long st_txq_refl_try; /* transmit queue refill attempt */ | |
49 | unsigned long st_rxq_enter; /* receive queue entered */ | |
50 | unsigned long st_rx2tx_tran; /* receive to trasmit transfers */ | |
51 | unsigned long st_rxq_notenter; /*receiveQ not entered, resched */ | |
52 | unsigned long st_rx_frm_egr; /* received from egress path */ | |
53 | unsigned long st_rx_frm_ing; /* received from ingress path */ | |
54 | unsigned long st_rxq_check; | |
55 | unsigned long st_rxq_rsch; | |
56 | struct sk_buff_head rq; | |
57 | struct sk_buff_head tq; | |
58 | }; | |
59 | ||
35eaa31e | 60 | static int numifbs = 2; |
253af423 JHS |
61 | |
62 | static void ri_tasklet(unsigned long dev); | |
63 | static int ifb_xmit(struct sk_buff *skb, struct net_device *dev); | |
64 | static struct net_device_stats *ifb_get_stats(struct net_device *dev); | |
65 | static int ifb_open(struct net_device *dev); | |
66 | static int ifb_close(struct net_device *dev); | |
67 | ||
68 | static void ri_tasklet(unsigned long dev) | |
69 | { | |
70 | ||
71 | struct net_device *_dev = (struct net_device *)dev; | |
72 | struct ifb_private *dp = netdev_priv(_dev); | |
73 | struct net_device_stats *stats = &dp->stats; | |
74 | struct sk_buff *skb; | |
75 | ||
76 | dp->st_task_enter++; | |
77 | if ((skb = skb_peek(&dp->tq)) == NULL) { | |
78 | dp->st_txq_refl_try++; | |
79 | if (spin_trylock(&_dev->xmit_lock)) { | |
80 | dp->st_rxq_enter++; | |
81 | while ((skb = skb_dequeue(&dp->rq)) != NULL) { | |
82 | skb_queue_tail(&dp->tq, skb); | |
83 | dp->st_rx2tx_tran++; | |
84 | } | |
85 | spin_unlock(&_dev->xmit_lock); | |
86 | } else { | |
87 | /* reschedule */ | |
88 | dp->st_rxq_notenter++; | |
89 | goto resched; | |
90 | } | |
91 | } | |
92 | ||
93 | while ((skb = skb_dequeue(&dp->tq)) != NULL) { | |
94 | u32 from = G_TC_FROM(skb->tc_verd); | |
95 | ||
96 | skb->tc_verd = 0; | |
97 | skb->tc_verd = SET_TC_NCLS(skb->tc_verd); | |
98 | stats->tx_packets++; | |
99 | stats->tx_bytes +=skb->len; | |
100 | if (from & AT_EGRESS) { | |
101 | dp->st_rx_frm_egr++; | |
102 | dev_queue_xmit(skb); | |
103 | } else if (from & AT_INGRESS) { | |
104 | ||
105 | dp->st_rx_frm_ing++; | |
106 | netif_rx(skb); | |
107 | } else { | |
108 | dev_kfree_skb(skb); | |
109 | stats->tx_dropped++; | |
110 | } | |
111 | } | |
112 | ||
113 | if (spin_trylock(&_dev->xmit_lock)) { | |
114 | dp->st_rxq_check++; | |
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 | dp->st_rxq_rsch++; | |
121 | spin_unlock(&_dev->xmit_lock); | |
122 | goto resched; | |
123 | } | |
124 | spin_unlock(&_dev->xmit_lock); | |
125 | } else { | |
126 | resched: | |
127 | dp->tasklet_pending = 1; | |
128 | tasklet_schedule(&dp->ifb_tasklet); | |
129 | } | |
130 | ||
131 | } | |
132 | ||
133 | static void __init ifb_setup(struct net_device *dev) | |
134 | { | |
135 | /* Initialize the device structure. */ | |
136 | dev->get_stats = ifb_get_stats; | |
137 | dev->hard_start_xmit = ifb_xmit; | |
138 | dev->open = &ifb_open; | |
139 | dev->stop = &ifb_close; | |
140 | ||
141 | /* Fill in device structure with ethernet-generic values. */ | |
142 | ether_setup(dev); | |
143 | dev->tx_queue_len = TX_Q_LIMIT; | |
144 | dev->change_mtu = NULL; | |
145 | dev->flags |= IFF_NOARP; | |
146 | dev->flags &= ~IFF_MULTICAST; | |
147 | SET_MODULE_OWNER(dev); | |
148 | random_ether_addr(dev->dev_addr); | |
149 | } | |
150 | ||
151 | static int ifb_xmit(struct sk_buff *skb, struct net_device *dev) | |
152 | { | |
153 | struct ifb_private *dp = netdev_priv(dev); | |
154 | struct net_device_stats *stats = &dp->stats; | |
155 | int ret = 0; | |
156 | u32 from = G_TC_FROM(skb->tc_verd); | |
157 | ||
158 | stats->tx_packets++; | |
159 | stats->tx_bytes+=skb->len; | |
160 | ||
161 | if (!from || !skb->input_dev) { | |
162 | dropped: | |
163 | dev_kfree_skb(skb); | |
164 | stats->rx_dropped++; | |
165 | return ret; | |
166 | } else { | |
167 | /* | |
168 | * note we could be going | |
169 | * ingress -> egress or | |
170 | * egress -> ingress | |
171 | */ | |
172 | skb->dev = skb->input_dev; | |
173 | skb->input_dev = dev; | |
174 | if (from & AT_INGRESS) { | |
175 | skb_pull(skb, skb->dev->hard_header_len); | |
176 | } else { | |
177 | if (!(from & AT_EGRESS)) { | |
178 | goto dropped; | |
179 | } | |
180 | } | |
181 | } | |
182 | ||
183 | if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) { | |
184 | netif_stop_queue(dev); | |
185 | } | |
186 | ||
187 | dev->trans_start = jiffies; | |
188 | skb_queue_tail(&dp->rq, skb); | |
189 | if (!dp->tasklet_pending) { | |
190 | dp->tasklet_pending = 1; | |
191 | tasklet_schedule(&dp->ifb_tasklet); | |
192 | } | |
193 | ||
194 | return ret; | |
195 | } | |
196 | ||
197 | static struct net_device_stats *ifb_get_stats(struct net_device *dev) | |
198 | { | |
199 | struct ifb_private *dp = netdev_priv(dev); | |
200 | struct net_device_stats *stats = &dp->stats; | |
201 | ||
202 | pr_debug("tasklets stats %ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld \n", | |
203 | dp->st_task_enter, dp->st_txq_refl_try, dp->st_rxq_enter, | |
204 | dp->st_rx2tx_tran dp->st_rxq_notenter, dp->st_rx_frm_egr, | |
205 | dp->st_rx_frm_ing, dp->st_rxq_check, dp->st_rxq_rsch ); | |
206 | ||
207 | return stats; | |
208 | } | |
209 | ||
210 | static struct net_device **ifbs; | |
211 | ||
212 | /* Number of ifb devices to be set up by this module. */ | |
213 | module_param(numifbs, int, 0); | |
214 | MODULE_PARM_DESC(numifbs, "Number of ifb devices"); | |
215 | ||
216 | static int ifb_close(struct net_device *dev) | |
217 | { | |
218 | struct ifb_private *dp = netdev_priv(dev); | |
219 | ||
220 | tasklet_kill(&dp->ifb_tasklet); | |
221 | netif_stop_queue(dev); | |
222 | skb_queue_purge(&dp->rq); | |
223 | skb_queue_purge(&dp->tq); | |
224 | return 0; | |
225 | } | |
226 | ||
227 | static int ifb_open(struct net_device *dev) | |
228 | { | |
229 | struct ifb_private *dp = netdev_priv(dev); | |
230 | ||
231 | tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev); | |
232 | skb_queue_head_init(&dp->rq); | |
233 | skb_queue_head_init(&dp->tq); | |
234 | netif_start_queue(dev); | |
235 | ||
236 | return 0; | |
237 | } | |
238 | ||
239 | static int __init ifb_init_one(int index) | |
240 | { | |
241 | struct net_device *dev_ifb; | |
242 | int err; | |
243 | ||
244 | dev_ifb = alloc_netdev(sizeof(struct ifb_private), | |
245 | "ifb%d", ifb_setup); | |
246 | ||
247 | if (!dev_ifb) | |
248 | return -ENOMEM; | |
249 | ||
250 | if ((err = register_netdev(dev_ifb))) { | |
251 | free_netdev(dev_ifb); | |
252 | dev_ifb = NULL; | |
253 | } else { | |
254 | ifbs[index] = dev_ifb; | |
255 | } | |
256 | ||
257 | return err; | |
258 | } | |
259 | ||
260 | static void ifb_free_one(int index) | |
261 | { | |
262 | unregister_netdev(ifbs[index]); | |
263 | free_netdev(ifbs[index]); | |
264 | } | |
265 | ||
266 | static int __init ifb_init_module(void) | |
267 | { | |
268 | int i, err = 0; | |
269 | ifbs = kmalloc(numifbs * sizeof(void *), GFP_KERNEL); | |
270 | if (!ifbs) | |
271 | return -ENOMEM; | |
272 | for (i = 0; i < numifbs && !err; i++) | |
273 | err = ifb_init_one(i); | |
274 | if (err) { | |
275 | while (--i >= 0) | |
276 | ifb_free_one(i); | |
277 | } | |
278 | ||
279 | return err; | |
280 | } | |
281 | ||
282 | static void __exit ifb_cleanup_module(void) | |
283 | { | |
284 | int i; | |
285 | ||
286 | for (i = 0; i < numifbs; i++) | |
287 | ifb_free_one(i); | |
288 | kfree(ifbs); | |
289 | } | |
290 | ||
291 | module_init(ifb_init_module); | |
292 | module_exit(ifb_cleanup_module); | |
293 | MODULE_LICENSE("GPL"); | |
294 | MODULE_AUTHOR("Jamal Hadi Salim"); |