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/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>
36 #include <linux/list.h>
37 #include <net/pkt_sched.h>
39 #define TX_TIMEOUT (2*HZ)
43 struct list_head list;
44 struct net_device *dev;
45 struct net_device_stats stats;
46 struct tasklet_struct ifb_tasklet;
48 /* mostly debug stats leave in for now */
49 unsigned long st_task_enter; /* tasklet entered */
50 unsigned long st_txq_refl_try; /* transmit queue refill attempt */
51 unsigned long st_rxq_enter; /* receive queue entered */
52 unsigned long st_rx2tx_tran; /* receive to trasmit transfers */
53 unsigned long st_rxq_notenter; /*receiveQ not entered, resched */
54 unsigned long st_rx_frm_egr; /* received from egress path */
55 unsigned long st_rx_frm_ing; /* received from ingress path */
56 unsigned long st_rxq_check;
57 unsigned long st_rxq_rsch;
58 struct sk_buff_head rq;
59 struct sk_buff_head tq;
62 static int numifbs = 2;
64 static void ri_tasklet(unsigned long dev);
65 static int ifb_xmit(struct sk_buff *skb, struct net_device *dev);
66 static struct net_device_stats *ifb_get_stats(struct net_device *dev);
67 static int ifb_open(struct net_device *dev);
68 static int ifb_close(struct net_device *dev);
70 static void ri_tasklet(unsigned long dev)
73 struct net_device *_dev = (struct net_device *)dev;
74 struct ifb_private *dp = netdev_priv(_dev);
75 struct net_device_stats *stats = &dp->stats;
79 if ((skb = skb_peek(&dp->tq)) == NULL) {
80 dp->st_txq_refl_try++;
81 if (netif_tx_trylock(_dev)) {
83 while ((skb = skb_dequeue(&dp->rq)) != NULL) {
84 skb_queue_tail(&dp->tq, skb);
87 netif_tx_unlock(_dev);
90 dp->st_rxq_notenter++;
95 while ((skb = skb_dequeue(&dp->tq)) != NULL) {
96 u32 from = G_TC_FROM(skb->tc_verd);
99 skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
101 stats->tx_bytes +=skb->len;
103 skb->dev = __dev_get_by_index(skb->iif);
109 skb->iif = _dev->ifindex;
111 if (from & AT_EGRESS) {
114 } else if (from & AT_INGRESS) {
116 skb_pull(skb, skb->dev->hard_header_len);
122 if (netif_tx_trylock(_dev)) {
124 if ((skb = skb_peek(&dp->rq)) == NULL) {
125 dp->tasklet_pending = 0;
126 if (netif_queue_stopped(_dev))
127 netif_wake_queue(_dev);
130 netif_tx_unlock(_dev);
133 netif_tx_unlock(_dev);
136 dp->tasklet_pending = 1;
137 tasklet_schedule(&dp->ifb_tasklet);
142 static void __init ifb_setup(struct net_device *dev)
144 /* Initialize the device structure. */
145 dev->get_stats = ifb_get_stats;
146 dev->hard_start_xmit = ifb_xmit;
147 dev->open = &ifb_open;
148 dev->stop = &ifb_close;
150 /* Fill in device structure with ethernet-generic values. */
152 dev->tx_queue_len = TX_Q_LIMIT;
153 dev->change_mtu = NULL;
154 dev->flags |= IFF_NOARP;
155 dev->flags &= ~IFF_MULTICAST;
156 SET_MODULE_OWNER(dev);
157 random_ether_addr(dev->dev_addr);
160 static int ifb_xmit(struct sk_buff *skb, struct net_device *dev)
162 struct ifb_private *dp = netdev_priv(dev);
163 struct net_device_stats *stats = &dp->stats;
165 u32 from = G_TC_FROM(skb->tc_verd);
168 stats->rx_bytes+=skb->len;
170 if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->iif) {
176 if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
177 netif_stop_queue(dev);
180 dev->trans_start = jiffies;
181 skb_queue_tail(&dp->rq, skb);
182 if (!dp->tasklet_pending) {
183 dp->tasklet_pending = 1;
184 tasklet_schedule(&dp->ifb_tasklet);
190 static struct net_device_stats *ifb_get_stats(struct net_device *dev)
192 struct ifb_private *dp = netdev_priv(dev);
193 struct net_device_stats *stats = &dp->stats;
195 pr_debug("tasklets stats %ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld \n",
196 dp->st_task_enter, dp->st_txq_refl_try, dp->st_rxq_enter,
197 dp->st_rx2tx_tran, dp->st_rxq_notenter, dp->st_rx_frm_egr,
198 dp->st_rx_frm_ing, dp->st_rxq_check, dp->st_rxq_rsch);
203 static LIST_HEAD(ifbs);
205 /* Number of ifb devices to be set up by this module. */
206 module_param(numifbs, int, 0);
207 MODULE_PARM_DESC(numifbs, "Number of ifb devices");
209 static int ifb_close(struct net_device *dev)
211 struct ifb_private *dp = netdev_priv(dev);
213 tasklet_kill(&dp->ifb_tasklet);
214 netif_stop_queue(dev);
215 skb_queue_purge(&dp->rq);
216 skb_queue_purge(&dp->tq);
220 static int ifb_open(struct net_device *dev)
222 struct ifb_private *dp = netdev_priv(dev);
224 tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev);
225 skb_queue_head_init(&dp->rq);
226 skb_queue_head_init(&dp->tq);
227 netif_start_queue(dev);
232 static int __init ifb_init_one(int index)
234 struct net_device *dev_ifb;
235 struct ifb_private *priv;
238 dev_ifb = alloc_netdev(sizeof(struct ifb_private),
244 if ((err = register_netdev(dev_ifb))) {
245 free_netdev(dev_ifb);
248 priv = netdev_priv(dev_ifb);
250 list_add_tail(&priv->list, &ifbs);
256 static void ifb_free_one(struct net_device *dev)
258 struct ifb_private *priv = netdev_priv(dev);
260 list_del(&priv->list);
261 unregister_netdev(dev);
265 static int __init ifb_init_module(void)
267 struct ifb_private *priv, *next;
270 for (i = 0; i < numifbs && !err; i++)
271 err = ifb_init_one(i);
273 list_for_each_entry_safe(priv, next, &ifbs, list)
274 ifb_free_one(priv->dev);
280 static void __exit ifb_cleanup_module(void)
282 struct ifb_private *priv, *next;
284 list_for_each_entry_safe(priv, next, &ifbs, list)
285 ifb_free_one(priv->dev);
288 module_init(ifb_init_module);
289 module_exit(ifb_cleanup_module);
290 MODULE_LICENSE("GPL");
291 MODULE_AUTHOR("Jamal Hadi Salim");