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/interrupt.h> 36 #include <linux/moduleparam.h> 37 #include <net/pkt_sched.h> 38 #include <net/net_namespace.h> 39 40 #define TX_Q_LIMIT 32 41 struct ifb_q_private { 42 struct net_device *dev; 43 struct tasklet_struct ifb_tasklet; 44 int tasklet_pending; 45 int txqnum; 46 struct sk_buff_head rq; 47 u64 rx_packets; 48 u64 rx_bytes; 49 struct u64_stats_sync rsync; 50 51 struct u64_stats_sync tsync; 52 u64 tx_packets; 53 u64 tx_bytes; 54 struct sk_buff_head tq; 55 } ____cacheline_aligned_in_smp; 56 57 struct ifb_dev_private { 58 struct ifb_q_private *tx_private; 59 }; 60 61 static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev); 62 static int ifb_open(struct net_device *dev); 63 static int ifb_close(struct net_device *dev); 64 65 static void ifb_ri_tasklet(unsigned long _txp) 66 { 67 struct ifb_q_private *txp = (struct ifb_q_private *)_txp; 68 struct netdev_queue *txq; 69 struct sk_buff *skb; 70 71 txq = netdev_get_tx_queue(txp->dev, txp->txqnum); 72 skb = skb_peek(&txp->tq); 73 if (!skb) { 74 if (!__netif_tx_trylock(txq)) 75 goto resched; 76 skb_queue_splice_tail_init(&txp->rq, &txp->tq); 77 __netif_tx_unlock(txq); 78 } 79 80 while ((skb = __skb_dequeue(&txp->tq)) != NULL) { 81 u32 from = G_TC_FROM(skb->tc_verd); 82 83 skb->tc_verd = 0; 84 skb->tc_verd = SET_TC_NCLS(skb->tc_verd); 85 86 u64_stats_update_begin(&txp->tsync); 87 txp->tx_packets++; 88 txp->tx_bytes += skb->len; 89 u64_stats_update_end(&txp->tsync); 90 91 rcu_read_lock(); 92 skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif); 93 if (!skb->dev) { 94 rcu_read_unlock(); 95 dev_kfree_skb(skb); 96 txp->dev->stats.tx_dropped++; 97 if (skb_queue_len(&txp->tq) != 0) 98 goto resched; 99 break; 100 } 101 rcu_read_unlock(); 102 skb->skb_iif = txp->dev->ifindex; 103 104 if (from & AT_EGRESS) { 105 dev_queue_xmit(skb); 106 } else if (from & AT_INGRESS) { 107 skb_pull(skb, skb->mac_len); 108 netif_receive_skb(skb); 109 } else 110 BUG(); 111 } 112 113 if (__netif_tx_trylock(txq)) { 114 skb = skb_peek(&txp->rq); 115 if (!skb) { 116 txp->tasklet_pending = 0; 117 if (netif_tx_queue_stopped(txq)) 118 netif_tx_wake_queue(txq); 119 } else { 120 __netif_tx_unlock(txq); 121 goto resched; 122 } 123 __netif_tx_unlock(txq); 124 } else { 125 resched: 126 txp->tasklet_pending = 1; 127 tasklet_schedule(&txp->ifb_tasklet); 128 } 129 130 } 131 132 static struct rtnl_link_stats64 *ifb_stats64(struct net_device *dev, 133 struct rtnl_link_stats64 *stats) 134 { 135 struct ifb_dev_private *dp = netdev_priv(dev); 136 struct ifb_q_private *txp = dp->tx_private; 137 unsigned int start; 138 u64 packets, bytes; 139 int i; 140 141 for (i = 0; i < dev->num_tx_queues; i++,txp++) { 142 do { 143 start = u64_stats_fetch_begin_irq(&txp->rsync); 144 packets = txp->rx_packets; 145 bytes = txp->rx_bytes; 146 } while (u64_stats_fetch_retry_irq(&txp->rsync, start)); 147 stats->rx_packets += packets; 148 stats->rx_bytes += bytes; 149 150 do { 151 start = u64_stats_fetch_begin_irq(&txp->tsync); 152 packets = txp->tx_packets; 153 bytes = txp->tx_bytes; 154 } while (u64_stats_fetch_retry_irq(&txp->tsync, start)); 155 stats->tx_packets += packets; 156 stats->tx_bytes += bytes; 157 } 158 stats->rx_dropped = dev->stats.rx_dropped; 159 stats->tx_dropped = dev->stats.tx_dropped; 160 161 return stats; 162 } 163 164 static int ifb_dev_init(struct net_device *dev) 165 { 166 struct ifb_dev_private *dp = netdev_priv(dev); 167 struct ifb_q_private *txp; 168 int i; 169 170 txp = kcalloc(dev->num_tx_queues, sizeof(*txp), GFP_KERNEL); 171 if (!txp) 172 return -ENOMEM; 173 dp->tx_private = txp; 174 for (i = 0; i < dev->num_tx_queues; i++,txp++) { 175 txp->txqnum = i; 176 txp->dev = dev; 177 __skb_queue_head_init(&txp->rq); 178 __skb_queue_head_init(&txp->tq); 179 u64_stats_init(&txp->rsync); 180 u64_stats_init(&txp->tsync); 181 tasklet_init(&txp->ifb_tasklet, ifb_ri_tasklet, 182 (unsigned long)txp); 183 netif_tx_start_queue(netdev_get_tx_queue(dev, i)); 184 } 185 return 0; 186 } 187 188 static const struct net_device_ops ifb_netdev_ops = { 189 .ndo_open = ifb_open, 190 .ndo_stop = ifb_close, 191 .ndo_get_stats64 = ifb_stats64, 192 .ndo_start_xmit = ifb_xmit, 193 .ndo_validate_addr = eth_validate_addr, 194 .ndo_init = ifb_dev_init, 195 }; 196 197 #define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_FRAGLIST | \ 198 NETIF_F_TSO_ECN | NETIF_F_TSO | NETIF_F_TSO6 | \ 199 NETIF_F_GSO_ENCAP_ALL | \ 200 NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX | \ 201 NETIF_F_HW_VLAN_STAG_TX) 202 203 static void ifb_dev_free(struct net_device *dev) 204 { 205 struct ifb_dev_private *dp = netdev_priv(dev); 206 struct ifb_q_private *txp = dp->tx_private; 207 int i; 208 209 for (i = 0; i < dev->num_tx_queues; i++,txp++) { 210 tasklet_kill(&txp->ifb_tasklet); 211 __skb_queue_purge(&txp->rq); 212 __skb_queue_purge(&txp->tq); 213 } 214 kfree(dp->tx_private); 215 free_netdev(dev); 216 } 217 218 static void ifb_setup(struct net_device *dev) 219 { 220 /* Initialize the device structure. */ 221 dev->netdev_ops = &ifb_netdev_ops; 222 223 /* Fill in device structure with ethernet-generic values. */ 224 ether_setup(dev); 225 dev->tx_queue_len = TX_Q_LIMIT; 226 227 dev->features |= IFB_FEATURES; 228 dev->hw_features |= dev->features; 229 dev->hw_enc_features |= dev->features; 230 dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX | 231 NETIF_F_HW_VLAN_STAG_TX); 232 233 dev->flags |= IFF_NOARP; 234 dev->flags &= ~IFF_MULTICAST; 235 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 236 netif_keep_dst(dev); 237 eth_hw_addr_random(dev); 238 dev->destructor = ifb_dev_free; 239 } 240 241 static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev) 242 { 243 struct ifb_dev_private *dp = netdev_priv(dev); 244 u32 from = G_TC_FROM(skb->tc_verd); 245 struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb); 246 247 u64_stats_update_begin(&txp->rsync); 248 txp->rx_packets++; 249 txp->rx_bytes += skb->len; 250 u64_stats_update_end(&txp->rsync); 251 252 if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) { 253 dev_kfree_skb(skb); 254 dev->stats.rx_dropped++; 255 return NETDEV_TX_OK; 256 } 257 258 if (skb_queue_len(&txp->rq) >= dev->tx_queue_len) 259 netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum)); 260 261 __skb_queue_tail(&txp->rq, skb); 262 if (!txp->tasklet_pending) { 263 txp->tasklet_pending = 1; 264 tasklet_schedule(&txp->ifb_tasklet); 265 } 266 267 return NETDEV_TX_OK; 268 } 269 270 static int ifb_close(struct net_device *dev) 271 { 272 netif_tx_stop_all_queues(dev); 273 return 0; 274 } 275 276 static int ifb_open(struct net_device *dev) 277 { 278 netif_tx_start_all_queues(dev); 279 return 0; 280 } 281 282 static int ifb_validate(struct nlattr *tb[], struct nlattr *data[]) 283 { 284 if (tb[IFLA_ADDRESS]) { 285 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 286 return -EINVAL; 287 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 288 return -EADDRNOTAVAIL; 289 } 290 return 0; 291 } 292 293 static struct rtnl_link_ops ifb_link_ops __read_mostly = { 294 .kind = "ifb", 295 .priv_size = sizeof(struct ifb_dev_private), 296 .setup = ifb_setup, 297 .validate = ifb_validate, 298 }; 299 300 /* Number of ifb devices to be set up by this module. 301 * Note that these legacy devices have one queue. 302 * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb 303 */ 304 static int numifbs = 2; 305 module_param(numifbs, int, 0); 306 MODULE_PARM_DESC(numifbs, "Number of ifb devices"); 307 308 static int __init ifb_init_one(int index) 309 { 310 struct net_device *dev_ifb; 311 int err; 312 313 dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d", 314 NET_NAME_UNKNOWN, ifb_setup); 315 316 if (!dev_ifb) 317 return -ENOMEM; 318 319 dev_ifb->rtnl_link_ops = &ifb_link_ops; 320 err = register_netdevice(dev_ifb); 321 if (err < 0) 322 goto err; 323 324 return 0; 325 326 err: 327 free_netdev(dev_ifb); 328 return err; 329 } 330 331 static int __init ifb_init_module(void) 332 { 333 int i, err; 334 335 rtnl_lock(); 336 err = __rtnl_link_register(&ifb_link_ops); 337 if (err < 0) 338 goto out; 339 340 for (i = 0; i < numifbs && !err; i++) { 341 err = ifb_init_one(i); 342 cond_resched(); 343 } 344 if (err) 345 __rtnl_link_unregister(&ifb_link_ops); 346 347 out: 348 rtnl_unlock(); 349 350 return err; 351 } 352 353 static void __exit ifb_cleanup_module(void) 354 { 355 rtnl_link_unregister(&ifb_link_ops); 356 } 357 358 module_init(ifb_init_module); 359 module_exit(ifb_cleanup_module); 360 MODULE_LICENSE("GPL"); 361 MODULE_AUTHOR("Jamal Hadi Salim"); 362 MODULE_ALIAS_RTNL_LINK("ifb"); 363