blob: 31fb2d75dc447a79bffa71f86d728425b68472a1 [file] [log] [blame]
Jamal Hadi Salim253af422006-01-08 22:34:25 -08001/* 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
42struct 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
Richard Lucassen35eaa312006-02-23 16:23:51 -080060static int numifbs = 2;
Jamal Hadi Salim253af422006-01-08 22:34:25 -080061
62static void ri_tasklet(unsigned long dev);
63static int ifb_xmit(struct sk_buff *skb, struct net_device *dev);
64static struct net_device_stats *ifb_get_stats(struct net_device *dev);
65static int ifb_open(struct net_device *dev);
66static int ifb_close(struct net_device *dev);
67
68static 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 {
126resched:
127 dp->tasklet_pending = 1;
128 tasklet_schedule(&dp->ifb_tasklet);
129 }
130
131}
132
133static 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
151static 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) {
162dropped:
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
197static 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
210static struct net_device **ifbs;
211
212/* Number of ifb devices to be set up by this module. */
213module_param(numifbs, int, 0);
214MODULE_PARM_DESC(numifbs, "Number of ifb devices");
215
216static 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
227static 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
239static 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
260static void ifb_free_one(int index)
261{
262 unregister_netdev(ifbs[index]);
263 free_netdev(ifbs[index]);
264}
265
266static 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
282static 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
291module_init(ifb_init_module);
292module_exit(ifb_cleanup_module);
293MODULE_LICENSE("GPL");
294MODULE_AUTHOR("Jamal Hadi Salim");