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 <net/pkt_sched.h>
37 #include <net/net_namespace.h>
39 #define TX_TIMEOUT (2*HZ)
43 struct tasklet_struct ifb_tasklet;
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;
59 static int numifbs = 2;
61 static void ri_tasklet(unsigned long dev);
62 static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
63 static int ifb_open(struct net_device *dev);
64 static int ifb_close(struct net_device *dev);
66 static void ri_tasklet(unsigned long dev)
69 struct net_device *_dev = (struct net_device *)dev;
70 struct ifb_private *dp = netdev_priv(_dev);
71 struct net_device_stats *stats = &_dev->stats;
72 struct netdev_queue *txq;
75 txq = netdev_get_tx_queue(_dev, 0);
77 if ((skb = skb_peek(&dp->tq)) == NULL) {
78 dp->st_txq_refl_try++;
79 if (__netif_tx_trylock(txq)) {
81 while ((skb = skb_dequeue(&dp->rq)) != NULL) {
82 skb_queue_tail(&dp->tq, skb);
85 __netif_tx_unlock(txq);
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;
102 skb->dev = dev_get_by_index_rcu(&init_net, skb->skb_iif);
107 if (skb_queue_len(&dp->tq) != 0)
112 skb->skb_iif = _dev->ifindex;
114 if (from & AT_EGRESS) {
117 } else if (from & AT_INGRESS) {
119 skb_pull(skb, skb->dev->hard_header_len);
125 if (__netif_tx_trylock(txq)) {
127 if ((skb = skb_peek(&dp->rq)) == NULL) {
128 dp->tasklet_pending = 0;
129 if (netif_queue_stopped(_dev))
130 netif_wake_queue(_dev);
133 __netif_tx_unlock(txq);
136 __netif_tx_unlock(txq);
139 dp->tasklet_pending = 1;
140 tasklet_schedule(&dp->ifb_tasklet);
145 static const struct net_device_ops ifb_netdev_ops = {
146 .ndo_open = ifb_open,
147 .ndo_stop = ifb_close,
148 .ndo_start_xmit = ifb_xmit,
149 .ndo_validate_addr = eth_validate_addr,
152 static void ifb_setup(struct net_device *dev)
154 /* Initialize the device structure. */
155 dev->destructor = free_netdev;
156 dev->netdev_ops = &ifb_netdev_ops;
158 /* Fill in device structure with ethernet-generic values. */
160 dev->tx_queue_len = TX_Q_LIMIT;
162 dev->flags |= IFF_NOARP;
163 dev->flags &= ~IFF_MULTICAST;
164 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
165 random_ether_addr(dev->dev_addr);
168 static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
170 struct ifb_private *dp = netdev_priv(dev);
171 struct net_device_stats *stats = &dev->stats;
172 u32 from = G_TC_FROM(skb->tc_verd);
175 stats->rx_bytes+=skb->len;
177 if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
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 int ifb_close(struct net_device *dev)
199 struct ifb_private *dp = netdev_priv(dev);
201 tasklet_kill(&dp->ifb_tasklet);
202 netif_stop_queue(dev);
203 skb_queue_purge(&dp->rq);
204 skb_queue_purge(&dp->tq);
208 static int ifb_open(struct net_device *dev)
210 struct ifb_private *dp = netdev_priv(dev);
212 tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev);
213 skb_queue_head_init(&dp->rq);
214 skb_queue_head_init(&dp->tq);
215 netif_start_queue(dev);
220 static int ifb_validate(struct nlattr *tb[], struct nlattr *data[])
222 if (tb[IFLA_ADDRESS]) {
223 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
225 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
226 return -EADDRNOTAVAIL;
231 static struct rtnl_link_ops ifb_link_ops __read_mostly = {
233 .priv_size = sizeof(struct ifb_private),
235 .validate = ifb_validate,
238 /* Number of ifb devices to be set up by this module. */
239 module_param(numifbs, int, 0);
240 MODULE_PARM_DESC(numifbs, "Number of ifb devices");
242 static int __init ifb_init_one(int index)
244 struct net_device *dev_ifb;
247 dev_ifb = alloc_netdev(sizeof(struct ifb_private),
253 err = dev_alloc_name(dev_ifb, dev_ifb->name);
257 dev_ifb->rtnl_link_ops = &ifb_link_ops;
258 err = register_netdevice(dev_ifb);
265 free_netdev(dev_ifb);
269 static int __init ifb_init_module(void)
274 err = __rtnl_link_register(&ifb_link_ops);
276 for (i = 0; i < numifbs && !err; i++)
277 err = ifb_init_one(i);
279 __rtnl_link_unregister(&ifb_link_ops);
285 static void __exit ifb_cleanup_module(void)
287 rtnl_link_unregister(&ifb_link_ops);
290 module_init(ifb_init_module);
291 module_exit(ifb_cleanup_module);
292 MODULE_LICENSE("GPL");
293 MODULE_AUTHOR("Jamal Hadi Salim");
294 MODULE_ALIAS_RTNL_LINK("ifb");