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"); 290