3 The purpose of this driver is to provide a device that allows
4 for sharing of resources:
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.
10 2) Allows for queueing incoming traffic for shaping instead of
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.
17 You need the tc action mirror or redirect to feed this device
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.
25 Authors: Jamal Hadi Salim (2005)
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>
39 #define TX_TIMEOUT (2*HZ)
43 struct net_device_stats stats;
44 struct tasklet_struct ifb_tasklet;
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;
60 static int numifbs = 2;
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);
68 static void ri_tasklet(unsigned long dev)
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;
77 if ((skb = skb_peek(&dp->tq)) == NULL) {
78 dp->st_txq_refl_try++;
79 if (netif_tx_trylock(_dev)) {
81 while ((skb = skb_dequeue(&dp->rq)) != NULL) {
82 skb_queue_tail(&dp->tq, skb);
85 netif_tx_unlock(_dev);
88 dp->st_rxq_notenter++;
93 while ((skb = skb_dequeue(&dp->tq)) != NULL) {
94 u32 from = G_TC_FROM(skb->tc_verd);
97 skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
99 stats->tx_bytes +=skb->len;
100 if (from & AT_EGRESS) {
103 } else if (from & AT_INGRESS) {
113 if (netif_tx_trylock(_dev)) {
115 if ((skb = skb_peek(&dp->rq)) == NULL) {
116 dp->tasklet_pending = 0;
117 if (netif_queue_stopped(_dev))
118 netif_wake_queue(_dev);
121 netif_tx_unlock(_dev);
124 netif_tx_unlock(_dev);
127 dp->tasklet_pending = 1;
128 tasklet_schedule(&dp->ifb_tasklet);
133 static void __init ifb_setup(struct net_device *dev)
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;
141 /* Fill in device structure with ethernet-generic values. */
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);
151 static int ifb_xmit(struct sk_buff *skb, struct net_device *dev)
153 struct ifb_private *dp = netdev_priv(dev);
154 struct net_device_stats *stats = &dp->stats;
156 u32 from = G_TC_FROM(skb->tc_verd);
159 stats->tx_bytes+=skb->len;
161 if (!from || !skb->input_dev) {
168 * note we could be going
169 * ingress -> egress or
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);
177 if (!(from & AT_EGRESS)) {
183 if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
184 netif_stop_queue(dev);
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);
197 static struct net_device_stats *ifb_get_stats(struct net_device *dev)
199 struct ifb_private *dp = netdev_priv(dev);
200 struct net_device_stats *stats = &dp->stats;
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 );
210 static struct net_device **ifbs;
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");
216 static int ifb_close(struct net_device *dev)
218 struct ifb_private *dp = netdev_priv(dev);
220 tasklet_kill(&dp->ifb_tasklet);
221 netif_stop_queue(dev);
222 skb_queue_purge(&dp->rq);
223 skb_queue_purge(&dp->tq);
227 static int ifb_open(struct net_device *dev)
229 struct ifb_private *dp = netdev_priv(dev);
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);
239 static int __init ifb_init_one(int index)
241 struct net_device *dev_ifb;
244 dev_ifb = alloc_netdev(sizeof(struct ifb_private),
250 if ((err = register_netdev(dev_ifb))) {
251 free_netdev(dev_ifb);
254 ifbs[index] = dev_ifb;
260 static void ifb_free_one(int index)
262 unregister_netdev(ifbs[index]);
263 free_netdev(ifbs[index]);
266 static int __init ifb_init_module(void)
269 ifbs = kmalloc(numifbs * sizeof(void *), GFP_KERNEL);
272 for (i = 0; i < numifbs && !err; i++)
273 err = ifb_init_one(i);
282 static void __exit ifb_cleanup_module(void)
286 for (i = 0; i < numifbs; i++)
291 module_init(ifb_init_module);
292 module_exit(ifb_cleanup_module);
293 MODULE_LICENSE("GPL");
294 MODULE_AUTHOR("Jamal Hadi Salim");