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1 | /* 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/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> | |
38 | ||
39 | #define TX_TIMEOUT (2*HZ) | |
40 | ||
41 | #define TX_Q_LIMIT 32 | |
42 | struct ifb_private { | |
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 | ||
59 | static int numifbs = 2; | |
60 | ||
61 | static void ri_tasklet(unsigned long dev); | |
62 | static int 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); | |
65 | ||
66 | static void ri_tasklet(unsigned long dev) | |
67 | { | |
68 | ||
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; | |
73 | struct sk_buff *skb; | |
74 | ||
75 | txq = netdev_get_tx_queue(_dev, 0); | |
76 | dp->st_task_enter++; | |
77 | if ((skb = skb_peek(&dp->tq)) == NULL) { | |
78 | dp->st_txq_refl_try++; | |
79 | if (__netif_tx_trylock(txq)) { | |
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 | __netif_tx_unlock(txq); | |
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 | ||
101 | skb->dev = __dev_get_by_index(&init_net, skb->iif); | |
102 | if (!skb->dev) { | |
103 | dev_kfree_skb(skb); | |
104 | stats->tx_dropped++; | |
105 | break; | |
106 | } | |
107 | skb->iif = _dev->ifindex; | |
108 | ||
109 | if (from & AT_EGRESS) { | |
110 | dp->st_rx_frm_egr++; | |
111 | dev_queue_xmit(skb); | |
112 | } else if (from & AT_INGRESS) { | |
113 | dp->st_rx_frm_ing++; | |
114 | skb_pull(skb, skb->dev->hard_header_len); | |
115 | netif_rx(skb); | |
116 | } else | |
117 | BUG(); | |
118 | } | |
119 | ||
120 | if (__netif_tx_trylock(txq)) { | |
121 | dp->st_rxq_check++; | |
122 | if ((skb = skb_peek(&dp->rq)) == NULL) { | |
123 | dp->tasklet_pending = 0; | |
124 | if (netif_queue_stopped(_dev)) | |
125 | netif_wake_queue(_dev); | |
126 | } else { | |
127 | dp->st_rxq_rsch++; | |
128 | __netif_tx_unlock(txq); | |
129 | goto resched; | |
130 | } | |
131 | __netif_tx_unlock(txq); | |
132 | } else { | |
133 | resched: | |
134 | dp->tasklet_pending = 1; | |
135 | tasklet_schedule(&dp->ifb_tasklet); | |
136 | } | |
137 | ||
138 | } | |
139 | ||
140 | static const struct net_device_ops ifb_netdev_ops = { | |
141 | .ndo_open = ifb_open, | |
142 | .ndo_stop = ifb_close, | |
143 | .ndo_start_xmit = ifb_xmit, | |
144 | .ndo_validate_addr = eth_validate_addr, | |
145 | }; | |
146 | ||
147 | static void ifb_setup(struct net_device *dev) | |
148 | { | |
149 | /* Initialize the device structure. */ | |
150 | dev->destructor = free_netdev; | |
151 | dev->netdev_ops = &ifb_netdev_ops; | |
152 | ||
153 | /* Fill in device structure with ethernet-generic values. */ | |
154 | ether_setup(dev); | |
155 | dev->tx_queue_len = TX_Q_LIMIT; | |
156 | ||
157 | dev->flags |= IFF_NOARP; | |
158 | dev->flags &= ~IFF_MULTICAST; | |
159 | random_ether_addr(dev->dev_addr); | |
160 | } | |
161 | ||
162 | static int ifb_xmit(struct sk_buff *skb, struct net_device *dev) | |
163 | { | |
164 | struct ifb_private *dp = netdev_priv(dev); | |
165 | struct net_device_stats *stats = &dev->stats; | |
166 | int ret = 0; | |
167 | u32 from = G_TC_FROM(skb->tc_verd); | |
168 | ||
169 | stats->rx_packets++; | |
170 | stats->rx_bytes+=skb->len; | |
171 | ||
172 | if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->iif) { | |
173 | dev_kfree_skb(skb); | |
174 | stats->rx_dropped++; | |
175 | return ret; | |
176 | } | |
177 | ||
178 | if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) { | |
179 | netif_stop_queue(dev); | |
180 | } | |
181 | ||
182 | dev->trans_start = jiffies; | |
183 | skb_queue_tail(&dp->rq, skb); | |
184 | if (!dp->tasklet_pending) { | |
185 | dp->tasklet_pending = 1; | |
186 | tasklet_schedule(&dp->ifb_tasklet); | |
187 | } | |
188 | ||
189 | return ret; | |
190 | } | |
191 | ||
192 | static int ifb_close(struct net_device *dev) | |
193 | { | |
194 | struct ifb_private *dp = netdev_priv(dev); | |
195 | ||
196 | tasklet_kill(&dp->ifb_tasklet); | |
197 | netif_stop_queue(dev); | |
198 | skb_queue_purge(&dp->rq); | |
199 | skb_queue_purge(&dp->tq); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | static int ifb_open(struct net_device *dev) | |
204 | { | |
205 | struct ifb_private *dp = netdev_priv(dev); | |
206 | ||
207 | tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev); | |
208 | skb_queue_head_init(&dp->rq); | |
209 | skb_queue_head_init(&dp->tq); | |
210 | netif_start_queue(dev); | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | static int ifb_validate(struct nlattr *tb[], struct nlattr *data[]) | |
216 | { | |
217 | if (tb[IFLA_ADDRESS]) { | |
218 | if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) | |
219 | return -EINVAL; | |
220 | if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) | |
221 | return -EADDRNOTAVAIL; | |
222 | } | |
223 | return 0; | |
224 | } | |
225 | ||
226 | static struct rtnl_link_ops ifb_link_ops __read_mostly = { | |
227 | .kind = "ifb", | |
228 | .priv_size = sizeof(struct ifb_private), | |
229 | .setup = ifb_setup, | |
230 | .validate = ifb_validate, | |
231 | }; | |
232 | ||
233 | /* Number of ifb devices to be set up by this module. */ | |
234 | module_param(numifbs, int, 0); | |
235 | MODULE_PARM_DESC(numifbs, "Number of ifb devices"); | |
236 | ||
237 | static int __init ifb_init_one(int index) | |
238 | { | |
239 | struct net_device *dev_ifb; | |
240 | int err; | |
241 | ||
242 | dev_ifb = alloc_netdev(sizeof(struct ifb_private), | |
243 | "ifb%d", ifb_setup); | |
244 | ||
245 | if (!dev_ifb) | |
246 | return -ENOMEM; | |
247 | ||
248 | err = dev_alloc_name(dev_ifb, dev_ifb->name); | |
249 | if (err < 0) | |
250 | goto err; | |
251 | ||
252 | dev_ifb->rtnl_link_ops = &ifb_link_ops; | |
253 | err = register_netdevice(dev_ifb); | |
254 | if (err < 0) | |
255 | goto err; | |
256 | ||
257 | return 0; | |
258 | ||
259 | err: | |
260 | free_netdev(dev_ifb); | |
261 | return err; | |
262 | } | |
263 | ||
264 | static int __init ifb_init_module(void) | |
265 | { | |
266 | int i, err; | |
267 | ||
268 | rtnl_lock(); | |
269 | err = __rtnl_link_register(&ifb_link_ops); | |
270 | ||
271 | for (i = 0; i < numifbs && !err; i++) | |
272 | err = ifb_init_one(i); | |
273 | if (err) | |
274 | __rtnl_link_unregister(&ifb_link_ops); | |
275 | rtnl_unlock(); | |
276 | ||
277 | return err; | |
278 | } | |
279 | ||
280 | static void __exit ifb_cleanup_module(void) | |
281 | { | |
282 | rtnl_link_unregister(&ifb_link_ops); | |
283 | } | |
284 | ||
285 | module_init(ifb_init_module); | |
286 | module_exit(ifb_cleanup_module); | |
287 | MODULE_LICENSE("GPL"); | |
288 | MODULE_AUTHOR("Jamal Hadi Salim"); | |
289 | MODULE_ALIAS_RTNL_LINK("ifb"); |