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Jeff Garzik6aa20a22006-09-13 13:24:59 -04001/* drivers/net/ifb.c:
Jamal Hadi Salim253af422006-01-08 22:34:25 -08002
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
Jeff Garzik6aa20a22006-09-13 13:24:59 -040011 dropping.
12
Jamal Hadi Salim253af422006-01-08 22:34:25 -080013 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.
Jeff Garzik6aa20a22006-09-13 13:24:59 -040024
Jamal Hadi Salim253af422006-01-08 22:34:25 -080025 Authors: Jamal Hadi Salim (2005)
Jeff Garzik6aa20a22006-09-13 13:24:59 -040026
Jamal Hadi Salim253af422006-01-08 22:34:25 -080027*/
28
29
Jamal Hadi Salim253af422006-01-08 22:34:25 -080030#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/moduleparam.h>
Jeff Garzik6aa20a22006-09-13 13:24:59 -040036#include <net/pkt_sched.h>
Jamal Hadi Salim253af422006-01-08 22:34:25 -080037
38#define TX_TIMEOUT (2*HZ)
Jeff Garzik6aa20a22006-09-13 13:24:59 -040039
Jamal Hadi Salim253af422006-01-08 22:34:25 -080040#define TX_Q_LIMIT 32
41struct ifb_private {
42 struct net_device_stats stats;
43 struct tasklet_struct ifb_tasklet;
44 int tasklet_pending;
45 /* mostly debug stats leave in for now */
46 unsigned long st_task_enter; /* tasklet entered */
47 unsigned long st_txq_refl_try; /* transmit queue refill attempt */
48 unsigned long st_rxq_enter; /* receive queue entered */
49 unsigned long st_rx2tx_tran; /* receive to trasmit transfers */
50 unsigned long st_rxq_notenter; /*receiveQ not entered, resched */
51 unsigned long st_rx_frm_egr; /* received from egress path */
52 unsigned long st_rx_frm_ing; /* received from ingress path */
53 unsigned long st_rxq_check;
54 unsigned long st_rxq_rsch;
55 struct sk_buff_head rq;
56 struct sk_buff_head tq;
57};
58
Richard Lucassen35eaa312006-02-23 16:23:51 -080059static int numifbs = 2;
Jamal Hadi Salim253af422006-01-08 22:34:25 -080060
61static void ri_tasklet(unsigned long dev);
62static int ifb_xmit(struct sk_buff *skb, struct net_device *dev);
63static struct net_device_stats *ifb_get_stats(struct net_device *dev);
64static int ifb_open(struct net_device *dev);
65static int ifb_close(struct net_device *dev);
66
Jeff Garzik6aa20a22006-09-13 13:24:59 -040067static void ri_tasklet(unsigned long dev)
Jamal Hadi Salim253af422006-01-08 22:34:25 -080068{
69
70 struct net_device *_dev = (struct net_device *)dev;
71 struct ifb_private *dp = netdev_priv(_dev);
72 struct net_device_stats *stats = &dp->stats;
73 struct sk_buff *skb;
74
75 dp->st_task_enter++;
76 if ((skb = skb_peek(&dp->tq)) == NULL) {
77 dp->st_txq_refl_try++;
Herbert Xu932ff272006-06-09 12:20:56 -070078 if (netif_tx_trylock(_dev)) {
Jamal Hadi Salim253af422006-01-08 22:34:25 -080079 dp->st_rxq_enter++;
80 while ((skb = skb_dequeue(&dp->rq)) != NULL) {
81 skb_queue_tail(&dp->tq, skb);
82 dp->st_rx2tx_tran++;
83 }
Herbert Xu932ff272006-06-09 12:20:56 -070084 netif_tx_unlock(_dev);
Jamal Hadi Salim253af422006-01-08 22:34:25 -080085 } else {
86 /* reschedule */
87 dp->st_rxq_notenter++;
88 goto resched;
89 }
90 }
91
92 while ((skb = skb_dequeue(&dp->tq)) != NULL) {
93 u32 from = G_TC_FROM(skb->tc_verd);
94
95 skb->tc_verd = 0;
96 skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
97 stats->tx_packets++;
98 stats->tx_bytes +=skb->len;
99 if (from & AT_EGRESS) {
100 dp->st_rx_frm_egr++;
101 dev_queue_xmit(skb);
102 } else if (from & AT_INGRESS) {
103
104 dp->st_rx_frm_ing++;
105 netif_rx(skb);
106 } else {
107 dev_kfree_skb(skb);
108 stats->tx_dropped++;
109 }
110 }
111
Herbert Xu932ff272006-06-09 12:20:56 -0700112 if (netif_tx_trylock(_dev)) {
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800113 dp->st_rxq_check++;
114 if ((skb = skb_peek(&dp->rq)) == NULL) {
115 dp->tasklet_pending = 0;
116 if (netif_queue_stopped(_dev))
117 netif_wake_queue(_dev);
118 } else {
119 dp->st_rxq_rsch++;
Herbert Xu932ff272006-06-09 12:20:56 -0700120 netif_tx_unlock(_dev);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800121 goto resched;
122 }
Herbert Xu932ff272006-06-09 12:20:56 -0700123 netif_tx_unlock(_dev);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800124 } else {
125resched:
126 dp->tasklet_pending = 1;
127 tasklet_schedule(&dp->ifb_tasklet);
128 }
129
130}
131
132static void __init ifb_setup(struct net_device *dev)
133{
134 /* Initialize the device structure. */
135 dev->get_stats = ifb_get_stats;
136 dev->hard_start_xmit = ifb_xmit;
137 dev->open = &ifb_open;
138 dev->stop = &ifb_close;
139
140 /* Fill in device structure with ethernet-generic values. */
141 ether_setup(dev);
142 dev->tx_queue_len = TX_Q_LIMIT;
143 dev->change_mtu = NULL;
144 dev->flags |= IFF_NOARP;
145 dev->flags &= ~IFF_MULTICAST;
146 SET_MODULE_OWNER(dev);
147 random_ether_addr(dev->dev_addr);
148}
149
150static int ifb_xmit(struct sk_buff *skb, struct net_device *dev)
151{
152 struct ifb_private *dp = netdev_priv(dev);
153 struct net_device_stats *stats = &dp->stats;
154 int ret = 0;
155 u32 from = G_TC_FROM(skb->tc_verd);
156
157 stats->tx_packets++;
158 stats->tx_bytes+=skb->len;
159
160 if (!from || !skb->input_dev) {
161dropped:
162 dev_kfree_skb(skb);
163 stats->rx_dropped++;
164 return ret;
165 } else {
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400166 /*
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800167 * note we could be going
168 * ingress -> egress or
169 * egress -> ingress
170 */
171 skb->dev = skb->input_dev;
172 skb->input_dev = dev;
173 if (from & AT_INGRESS) {
174 skb_pull(skb, skb->dev->hard_header_len);
175 } else {
176 if (!(from & AT_EGRESS)) {
177 goto dropped;
178 }
179 }
180 }
181
182 if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
183 netif_stop_queue(dev);
184 }
185
186 dev->trans_start = jiffies;
187 skb_queue_tail(&dp->rq, skb);
188 if (!dp->tasklet_pending) {
189 dp->tasklet_pending = 1;
190 tasklet_schedule(&dp->ifb_tasklet);
191 }
192
193 return ret;
194}
195
196static struct net_device_stats *ifb_get_stats(struct net_device *dev)
197{
198 struct ifb_private *dp = netdev_priv(dev);
199 struct net_device_stats *stats = &dp->stats;
200
201 pr_debug("tasklets stats %ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld \n",
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400202 dp->st_task_enter, dp->st_txq_refl_try, dp->st_rxq_enter,
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800203 dp->st_rx2tx_tran dp->st_rxq_notenter, dp->st_rx_frm_egr,
204 dp->st_rx_frm_ing, dp->st_rxq_check, dp->st_rxq_rsch );
205
206 return stats;
207}
208
209static struct net_device **ifbs;
210
211/* Number of ifb devices to be set up by this module. */
212module_param(numifbs, int, 0);
213MODULE_PARM_DESC(numifbs, "Number of ifb devices");
214
215static int ifb_close(struct net_device *dev)
216{
217 struct ifb_private *dp = netdev_priv(dev);
218
219 tasklet_kill(&dp->ifb_tasklet);
220 netif_stop_queue(dev);
221 skb_queue_purge(&dp->rq);
222 skb_queue_purge(&dp->tq);
223 return 0;
224}
225
226static int ifb_open(struct net_device *dev)
227{
228 struct ifb_private *dp = netdev_priv(dev);
229
230 tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev);
231 skb_queue_head_init(&dp->rq);
232 skb_queue_head_init(&dp->tq);
233 netif_start_queue(dev);
234
235 return 0;
236}
237
238static int __init ifb_init_one(int index)
239{
240 struct net_device *dev_ifb;
241 int err;
242
243 dev_ifb = alloc_netdev(sizeof(struct ifb_private),
244 "ifb%d", ifb_setup);
245
246 if (!dev_ifb)
247 return -ENOMEM;
248
249 if ((err = register_netdev(dev_ifb))) {
250 free_netdev(dev_ifb);
251 dev_ifb = NULL;
252 } else {
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400253 ifbs[index] = dev_ifb;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800254 }
255
256 return err;
257}
258
259static void ifb_free_one(int index)
260{
261 unregister_netdev(ifbs[index]);
262 free_netdev(ifbs[index]);
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400263}
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800264
265static int __init ifb_init_module(void)
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400266{
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800267 int i, err = 0;
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400268 ifbs = kmalloc(numifbs * sizeof(void *), GFP_KERNEL);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800269 if (!ifbs)
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400270 return -ENOMEM;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800271 for (i = 0; i < numifbs && !err; i++)
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400272 err = ifb_init_one(i);
273 if (err) {
Nicolas Dichtel4a9c74e2006-07-21 14:56:02 -0700274 i--;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800275 while (--i >= 0)
276 ifb_free_one(i);
277 }
278
279 return err;
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400280}
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800281
282static void __exit ifb_cleanup_module(void)
283{
284 int i;
285
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400286 for (i = 0; i < numifbs; i++)
287 ifb_free_one(i);
288 kfree(ifbs);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800289}
290
291module_init(ifb_init_module);
292module_exit(ifb_cleanup_module);
293MODULE_LICENSE("GPL");
294MODULE_AUTHOR("Jamal Hadi Salim");