| 1 | #include <linux/etherdevice.h> |
| 2 | #include <linux/if_macvlan.h> |
| 3 | #include <linux/if_vlan.h> |
| 4 | #include <linux/interrupt.h> |
| 5 | #include <linux/nsproxy.h> |
| 6 | #include <linux/compat.h> |
| 7 | #include <linux/if_tun.h> |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/skbuff.h> |
| 10 | #include <linux/cache.h> |
| 11 | #include <linux/sched.h> |
| 12 | #include <linux/types.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/wait.h> |
| 15 | #include <linux/cdev.h> |
| 16 | #include <linux/idr.h> |
| 17 | #include <linux/fs.h> |
| 18 | |
| 19 | #include <net/ipv6.h> |
| 20 | #include <net/net_namespace.h> |
| 21 | #include <net/rtnetlink.h> |
| 22 | #include <net/sock.h> |
| 23 | #include <linux/virtio_net.h> |
| 24 | |
| 25 | /* |
| 26 | * A macvtap queue is the central object of this driver, it connects |
| 27 | * an open character device to a macvlan interface. There can be |
| 28 | * multiple queues on one interface, which map back to queues |
| 29 | * implemented in hardware on the underlying device. |
| 30 | * |
| 31 | * macvtap_proto is used to allocate queues through the sock allocation |
| 32 | * mechanism. |
| 33 | * |
| 34 | */ |
| 35 | struct macvtap_queue { |
| 36 | struct sock sk; |
| 37 | struct socket sock; |
| 38 | struct socket_wq wq; |
| 39 | int vnet_hdr_sz; |
| 40 | struct macvlan_dev __rcu *vlan; |
| 41 | struct file *file; |
| 42 | unsigned int flags; |
| 43 | u16 queue_index; |
| 44 | bool enabled; |
| 45 | struct list_head next; |
| 46 | }; |
| 47 | |
| 48 | static struct proto macvtap_proto = { |
| 49 | .name = "macvtap", |
| 50 | .owner = THIS_MODULE, |
| 51 | .obj_size = sizeof (struct macvtap_queue), |
| 52 | }; |
| 53 | |
| 54 | /* |
| 55 | * Variables for dealing with macvtaps device numbers. |
| 56 | */ |
| 57 | static dev_t macvtap_major; |
| 58 | #define MACVTAP_NUM_DEVS (1U << MINORBITS) |
| 59 | static DEFINE_MUTEX(minor_lock); |
| 60 | static DEFINE_IDR(minor_idr); |
| 61 | |
| 62 | #define GOODCOPY_LEN 128 |
| 63 | static struct class *macvtap_class; |
| 64 | static struct cdev macvtap_cdev; |
| 65 | |
| 66 | static const struct proto_ops macvtap_socket_ops; |
| 67 | |
| 68 | #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \ |
| 69 | NETIF_F_TSO6) |
| 70 | #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO) |
| 71 | #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG) |
| 72 | |
| 73 | static struct macvlan_dev *macvtap_get_vlan_rcu(const struct net_device *dev) |
| 74 | { |
| 75 | return rcu_dereference(dev->rx_handler_data); |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * RCU usage: |
| 80 | * The macvtap_queue and the macvlan_dev are loosely coupled, the |
| 81 | * pointers from one to the other can only be read while rcu_read_lock |
| 82 | * or rtnl is held. |
| 83 | * |
| 84 | * Both the file and the macvlan_dev hold a reference on the macvtap_queue |
| 85 | * through sock_hold(&q->sk). When the macvlan_dev goes away first, |
| 86 | * q->vlan becomes inaccessible. When the files gets closed, |
| 87 | * macvtap_get_queue() fails. |
| 88 | * |
| 89 | * There may still be references to the struct sock inside of the |
| 90 | * queue from outbound SKBs, but these never reference back to the |
| 91 | * file or the dev. The data structure is freed through __sk_free |
| 92 | * when both our references and any pending SKBs are gone. |
| 93 | */ |
| 94 | |
| 95 | static int macvtap_enable_queue(struct net_device *dev, struct file *file, |
| 96 | struct macvtap_queue *q) |
| 97 | { |
| 98 | struct macvlan_dev *vlan = netdev_priv(dev); |
| 99 | int err = -EINVAL; |
| 100 | |
| 101 | ASSERT_RTNL(); |
| 102 | |
| 103 | if (q->enabled) |
| 104 | goto out; |
| 105 | |
| 106 | err = 0; |
| 107 | rcu_assign_pointer(vlan->taps[vlan->numvtaps], q); |
| 108 | q->queue_index = vlan->numvtaps; |
| 109 | q->enabled = true; |
| 110 | |
| 111 | vlan->numvtaps++; |
| 112 | out: |
| 113 | return err; |
| 114 | } |
| 115 | |
| 116 | /* Requires RTNL */ |
| 117 | static int macvtap_set_queue(struct net_device *dev, struct file *file, |
| 118 | struct macvtap_queue *q) |
| 119 | { |
| 120 | struct macvlan_dev *vlan = netdev_priv(dev); |
| 121 | |
| 122 | if (vlan->numqueues == MAX_MACVTAP_QUEUES) |
| 123 | return -EBUSY; |
| 124 | |
| 125 | rcu_assign_pointer(q->vlan, vlan); |
| 126 | rcu_assign_pointer(vlan->taps[vlan->numvtaps], q); |
| 127 | sock_hold(&q->sk); |
| 128 | |
| 129 | q->file = file; |
| 130 | q->queue_index = vlan->numvtaps; |
| 131 | q->enabled = true; |
| 132 | file->private_data = q; |
| 133 | list_add_tail(&q->next, &vlan->queue_list); |
| 134 | |
| 135 | vlan->numvtaps++; |
| 136 | vlan->numqueues++; |
| 137 | |
| 138 | return 0; |
| 139 | } |
| 140 | |
| 141 | static int macvtap_disable_queue(struct macvtap_queue *q) |
| 142 | { |
| 143 | struct macvlan_dev *vlan; |
| 144 | struct macvtap_queue *nq; |
| 145 | |
| 146 | ASSERT_RTNL(); |
| 147 | if (!q->enabled) |
| 148 | return -EINVAL; |
| 149 | |
| 150 | vlan = rtnl_dereference(q->vlan); |
| 151 | |
| 152 | if (vlan) { |
| 153 | int index = q->queue_index; |
| 154 | BUG_ON(index >= vlan->numvtaps); |
| 155 | nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]); |
| 156 | nq->queue_index = index; |
| 157 | |
| 158 | rcu_assign_pointer(vlan->taps[index], nq); |
| 159 | RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL); |
| 160 | q->enabled = false; |
| 161 | |
| 162 | vlan->numvtaps--; |
| 163 | } |
| 164 | |
| 165 | return 0; |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | * The file owning the queue got closed, give up both |
| 170 | * the reference that the files holds as well as the |
| 171 | * one from the macvlan_dev if that still exists. |
| 172 | * |
| 173 | * Using the spinlock makes sure that we don't get |
| 174 | * to the queue again after destroying it. |
| 175 | */ |
| 176 | static void macvtap_put_queue(struct macvtap_queue *q) |
| 177 | { |
| 178 | struct macvlan_dev *vlan; |
| 179 | |
| 180 | rtnl_lock(); |
| 181 | vlan = rtnl_dereference(q->vlan); |
| 182 | |
| 183 | if (vlan) { |
| 184 | if (q->enabled) |
| 185 | BUG_ON(macvtap_disable_queue(q)); |
| 186 | |
| 187 | vlan->numqueues--; |
| 188 | RCU_INIT_POINTER(q->vlan, NULL); |
| 189 | sock_put(&q->sk); |
| 190 | list_del_init(&q->next); |
| 191 | } |
| 192 | |
| 193 | rtnl_unlock(); |
| 194 | |
| 195 | synchronize_rcu(); |
| 196 | sock_put(&q->sk); |
| 197 | } |
| 198 | |
| 199 | /* |
| 200 | * Select a queue based on the rxq of the device on which this packet |
| 201 | * arrived. If the incoming device is not mq, calculate a flow hash |
| 202 | * to select a queue. If all fails, find the first available queue. |
| 203 | * Cache vlan->numvtaps since it can become zero during the execution |
| 204 | * of this function. |
| 205 | */ |
| 206 | static struct macvtap_queue *macvtap_get_queue(struct net_device *dev, |
| 207 | struct sk_buff *skb) |
| 208 | { |
| 209 | struct macvlan_dev *vlan = netdev_priv(dev); |
| 210 | struct macvtap_queue *tap = NULL; |
| 211 | /* Access to taps array is protected by rcu, but access to numvtaps |
| 212 | * isn't. Below we use it to lookup a queue, but treat it as a hint |
| 213 | * and validate that the result isn't NULL - in case we are |
| 214 | * racing against queue removal. |
| 215 | */ |
| 216 | int numvtaps = ACCESS_ONCE(vlan->numvtaps); |
| 217 | __u32 rxq; |
| 218 | |
| 219 | if (!numvtaps) |
| 220 | goto out; |
| 221 | |
| 222 | /* Check if we can use flow to select a queue */ |
| 223 | rxq = skb_get_hash(skb); |
| 224 | if (rxq) { |
| 225 | tap = rcu_dereference(vlan->taps[rxq % numvtaps]); |
| 226 | goto out; |
| 227 | } |
| 228 | |
| 229 | if (likely(skb_rx_queue_recorded(skb))) { |
| 230 | rxq = skb_get_rx_queue(skb); |
| 231 | |
| 232 | while (unlikely(rxq >= numvtaps)) |
| 233 | rxq -= numvtaps; |
| 234 | |
| 235 | tap = rcu_dereference(vlan->taps[rxq]); |
| 236 | goto out; |
| 237 | } |
| 238 | |
| 239 | tap = rcu_dereference(vlan->taps[0]); |
| 240 | out: |
| 241 | return tap; |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * The net_device is going away, give up the reference |
| 246 | * that it holds on all queues and safely set the pointer |
| 247 | * from the queues to NULL. |
| 248 | */ |
| 249 | static void macvtap_del_queues(struct net_device *dev) |
| 250 | { |
| 251 | struct macvlan_dev *vlan = netdev_priv(dev); |
| 252 | struct macvtap_queue *q, *tmp, *qlist[MAX_MACVTAP_QUEUES]; |
| 253 | int i, j = 0; |
| 254 | |
| 255 | ASSERT_RTNL(); |
| 256 | list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) { |
| 257 | list_del_init(&q->next); |
| 258 | qlist[j++] = q; |
| 259 | RCU_INIT_POINTER(q->vlan, NULL); |
| 260 | if (q->enabled) |
| 261 | vlan->numvtaps--; |
| 262 | vlan->numqueues--; |
| 263 | } |
| 264 | for (i = 0; i < vlan->numvtaps; i++) |
| 265 | RCU_INIT_POINTER(vlan->taps[i], NULL); |
| 266 | BUG_ON(vlan->numvtaps); |
| 267 | BUG_ON(vlan->numqueues); |
| 268 | /* guarantee that any future macvtap_set_queue will fail */ |
| 269 | vlan->numvtaps = MAX_MACVTAP_QUEUES; |
| 270 | |
| 271 | for (--j; j >= 0; j--) |
| 272 | sock_put(&qlist[j]->sk); |
| 273 | } |
| 274 | |
| 275 | static rx_handler_result_t macvtap_handle_frame(struct sk_buff **pskb) |
| 276 | { |
| 277 | struct sk_buff *skb = *pskb; |
| 278 | struct net_device *dev = skb->dev; |
| 279 | struct macvlan_dev *vlan; |
| 280 | struct macvtap_queue *q; |
| 281 | netdev_features_t features = TAP_FEATURES; |
| 282 | |
| 283 | vlan = macvtap_get_vlan_rcu(dev); |
| 284 | if (!vlan) |
| 285 | return RX_HANDLER_PASS; |
| 286 | |
| 287 | q = macvtap_get_queue(dev, skb); |
| 288 | if (!q) |
| 289 | return RX_HANDLER_PASS; |
| 290 | |
| 291 | if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len) |
| 292 | goto drop; |
| 293 | |
| 294 | skb_push(skb, ETH_HLEN); |
| 295 | |
| 296 | /* Apply the forward feature mask so that we perform segmentation |
| 297 | * according to users wishes. This only works if VNET_HDR is |
| 298 | * enabled. |
| 299 | */ |
| 300 | if (q->flags & IFF_VNET_HDR) |
| 301 | features |= vlan->tap_features; |
| 302 | if (netif_needs_gso(dev, skb, features)) { |
| 303 | struct sk_buff *segs = __skb_gso_segment(skb, features, false); |
| 304 | |
| 305 | if (IS_ERR(segs)) |
| 306 | goto drop; |
| 307 | |
| 308 | if (!segs) { |
| 309 | skb_queue_tail(&q->sk.sk_receive_queue, skb); |
| 310 | goto wake_up; |
| 311 | } |
| 312 | |
| 313 | kfree_skb(skb); |
| 314 | while (segs) { |
| 315 | struct sk_buff *nskb = segs->next; |
| 316 | |
| 317 | segs->next = NULL; |
| 318 | skb_queue_tail(&q->sk.sk_receive_queue, segs); |
| 319 | segs = nskb; |
| 320 | } |
| 321 | } else { |
| 322 | /* If we receive a partial checksum and the tap side |
| 323 | * doesn't support checksum offload, compute the checksum. |
| 324 | * Note: it doesn't matter which checksum feature to |
| 325 | * check, we either support them all or none. |
| 326 | */ |
| 327 | if (skb->ip_summed == CHECKSUM_PARTIAL && |
| 328 | !(features & NETIF_F_ALL_CSUM) && |
| 329 | skb_checksum_help(skb)) |
| 330 | goto drop; |
| 331 | skb_queue_tail(&q->sk.sk_receive_queue, skb); |
| 332 | } |
| 333 | |
| 334 | wake_up: |
| 335 | wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND); |
| 336 | return RX_HANDLER_CONSUMED; |
| 337 | |
| 338 | drop: |
| 339 | /* Count errors/drops only here, thus don't care about args. */ |
| 340 | macvlan_count_rx(vlan, 0, 0, 0); |
| 341 | kfree_skb(skb); |
| 342 | return RX_HANDLER_CONSUMED; |
| 343 | } |
| 344 | |
| 345 | static int macvtap_get_minor(struct macvlan_dev *vlan) |
| 346 | { |
| 347 | int retval = -ENOMEM; |
| 348 | |
| 349 | mutex_lock(&minor_lock); |
| 350 | retval = idr_alloc(&minor_idr, vlan, 1, MACVTAP_NUM_DEVS, GFP_KERNEL); |
| 351 | if (retval >= 0) { |
| 352 | vlan->minor = retval; |
| 353 | } else if (retval == -ENOSPC) { |
| 354 | printk(KERN_ERR "too many macvtap devices\n"); |
| 355 | retval = -EINVAL; |
| 356 | } |
| 357 | mutex_unlock(&minor_lock); |
| 358 | return retval < 0 ? retval : 0; |
| 359 | } |
| 360 | |
| 361 | static void macvtap_free_minor(struct macvlan_dev *vlan) |
| 362 | { |
| 363 | mutex_lock(&minor_lock); |
| 364 | if (vlan->minor) { |
| 365 | idr_remove(&minor_idr, vlan->minor); |
| 366 | vlan->minor = 0; |
| 367 | } |
| 368 | mutex_unlock(&minor_lock); |
| 369 | } |
| 370 | |
| 371 | static struct net_device *dev_get_by_macvtap_minor(int minor) |
| 372 | { |
| 373 | struct net_device *dev = NULL; |
| 374 | struct macvlan_dev *vlan; |
| 375 | |
| 376 | mutex_lock(&minor_lock); |
| 377 | vlan = idr_find(&minor_idr, minor); |
| 378 | if (vlan) { |
| 379 | dev = vlan->dev; |
| 380 | dev_hold(dev); |
| 381 | } |
| 382 | mutex_unlock(&minor_lock); |
| 383 | return dev; |
| 384 | } |
| 385 | |
| 386 | static int macvtap_newlink(struct net *src_net, |
| 387 | struct net_device *dev, |
| 388 | struct nlattr *tb[], |
| 389 | struct nlattr *data[]) |
| 390 | { |
| 391 | struct macvlan_dev *vlan = netdev_priv(dev); |
| 392 | int err; |
| 393 | |
| 394 | INIT_LIST_HEAD(&vlan->queue_list); |
| 395 | |
| 396 | /* Since macvlan supports all offloads by default, make |
| 397 | * tap support all offloads also. |
| 398 | */ |
| 399 | vlan->tap_features = TUN_OFFLOADS; |
| 400 | |
| 401 | err = netdev_rx_handler_register(dev, macvtap_handle_frame, vlan); |
| 402 | if (err) |
| 403 | return err; |
| 404 | |
| 405 | /* Don't put anything that may fail after macvlan_common_newlink |
| 406 | * because we can't undo what it does. |
| 407 | */ |
| 408 | return macvlan_common_newlink(src_net, dev, tb, data); |
| 409 | } |
| 410 | |
| 411 | static void macvtap_dellink(struct net_device *dev, |
| 412 | struct list_head *head) |
| 413 | { |
| 414 | netdev_rx_handler_unregister(dev); |
| 415 | macvtap_del_queues(dev); |
| 416 | macvlan_dellink(dev, head); |
| 417 | } |
| 418 | |
| 419 | static void macvtap_setup(struct net_device *dev) |
| 420 | { |
| 421 | macvlan_common_setup(dev); |
| 422 | dev->tx_queue_len = TUN_READQ_SIZE; |
| 423 | } |
| 424 | |
| 425 | static struct rtnl_link_ops macvtap_link_ops __read_mostly = { |
| 426 | .kind = "macvtap", |
| 427 | .setup = macvtap_setup, |
| 428 | .newlink = macvtap_newlink, |
| 429 | .dellink = macvtap_dellink, |
| 430 | }; |
| 431 | |
| 432 | |
| 433 | static void macvtap_sock_write_space(struct sock *sk) |
| 434 | { |
| 435 | wait_queue_head_t *wqueue; |
| 436 | |
| 437 | if (!sock_writeable(sk) || |
| 438 | !test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags)) |
| 439 | return; |
| 440 | |
| 441 | wqueue = sk_sleep(sk); |
| 442 | if (wqueue && waitqueue_active(wqueue)) |
| 443 | wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND); |
| 444 | } |
| 445 | |
| 446 | static void macvtap_sock_destruct(struct sock *sk) |
| 447 | { |
| 448 | skb_queue_purge(&sk->sk_receive_queue); |
| 449 | } |
| 450 | |
| 451 | static int macvtap_open(struct inode *inode, struct file *file) |
| 452 | { |
| 453 | struct net *net = current->nsproxy->net_ns; |
| 454 | struct net_device *dev; |
| 455 | struct macvtap_queue *q; |
| 456 | int err = -ENODEV; |
| 457 | |
| 458 | rtnl_lock(); |
| 459 | dev = dev_get_by_macvtap_minor(iminor(inode)); |
| 460 | if (!dev) |
| 461 | goto out; |
| 462 | |
| 463 | err = -ENOMEM; |
| 464 | q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, |
| 465 | &macvtap_proto); |
| 466 | if (!q) |
| 467 | goto out; |
| 468 | |
| 469 | RCU_INIT_POINTER(q->sock.wq, &q->wq); |
| 470 | init_waitqueue_head(&q->wq.wait); |
| 471 | q->sock.type = SOCK_RAW; |
| 472 | q->sock.state = SS_CONNECTED; |
| 473 | q->sock.file = file; |
| 474 | q->sock.ops = &macvtap_socket_ops; |
| 475 | sock_init_data(&q->sock, &q->sk); |
| 476 | q->sk.sk_write_space = macvtap_sock_write_space; |
| 477 | q->sk.sk_destruct = macvtap_sock_destruct; |
| 478 | q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; |
| 479 | q->vnet_hdr_sz = sizeof(struct virtio_net_hdr); |
| 480 | |
| 481 | /* |
| 482 | * so far only KVM virtio_net uses macvtap, enable zero copy between |
| 483 | * guest kernel and host kernel when lower device supports zerocopy |
| 484 | * |
| 485 | * The macvlan supports zerocopy iff the lower device supports zero |
| 486 | * copy so we don't have to look at the lower device directly. |
| 487 | */ |
| 488 | if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG)) |
| 489 | sock_set_flag(&q->sk, SOCK_ZEROCOPY); |
| 490 | |
| 491 | err = macvtap_set_queue(dev, file, q); |
| 492 | if (err) |
| 493 | sock_put(&q->sk); |
| 494 | |
| 495 | out: |
| 496 | if (dev) |
| 497 | dev_put(dev); |
| 498 | |
| 499 | rtnl_unlock(); |
| 500 | return err; |
| 501 | } |
| 502 | |
| 503 | static int macvtap_release(struct inode *inode, struct file *file) |
| 504 | { |
| 505 | struct macvtap_queue *q = file->private_data; |
| 506 | macvtap_put_queue(q); |
| 507 | return 0; |
| 508 | } |
| 509 | |
| 510 | static unsigned int macvtap_poll(struct file *file, poll_table * wait) |
| 511 | { |
| 512 | struct macvtap_queue *q = file->private_data; |
| 513 | unsigned int mask = POLLERR; |
| 514 | |
| 515 | if (!q) |
| 516 | goto out; |
| 517 | |
| 518 | mask = 0; |
| 519 | poll_wait(file, &q->wq.wait, wait); |
| 520 | |
| 521 | if (!skb_queue_empty(&q->sk.sk_receive_queue)) |
| 522 | mask |= POLLIN | POLLRDNORM; |
| 523 | |
| 524 | if (sock_writeable(&q->sk) || |
| 525 | (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock.flags) && |
| 526 | sock_writeable(&q->sk))) |
| 527 | mask |= POLLOUT | POLLWRNORM; |
| 528 | |
| 529 | out: |
| 530 | return mask; |
| 531 | } |
| 532 | |
| 533 | static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad, |
| 534 | size_t len, size_t linear, |
| 535 | int noblock, int *err) |
| 536 | { |
| 537 | struct sk_buff *skb; |
| 538 | |
| 539 | /* Under a page? Don't bother with paged skb. */ |
| 540 | if (prepad + len < PAGE_SIZE || !linear) |
| 541 | linear = len; |
| 542 | |
| 543 | skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, |
| 544 | err, 0); |
| 545 | if (!skb) |
| 546 | return NULL; |
| 547 | |
| 548 | skb_reserve(skb, prepad); |
| 549 | skb_put(skb, linear); |
| 550 | skb->data_len = len - linear; |
| 551 | skb->len += len - linear; |
| 552 | |
| 553 | return skb; |
| 554 | } |
| 555 | |
| 556 | /* |
| 557 | * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should |
| 558 | * be shared with the tun/tap driver. |
| 559 | */ |
| 560 | static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb, |
| 561 | struct virtio_net_hdr *vnet_hdr) |
| 562 | { |
| 563 | unsigned short gso_type = 0; |
| 564 | if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { |
| 565 | switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { |
| 566 | case VIRTIO_NET_HDR_GSO_TCPV4: |
| 567 | gso_type = SKB_GSO_TCPV4; |
| 568 | break; |
| 569 | case VIRTIO_NET_HDR_GSO_TCPV6: |
| 570 | gso_type = SKB_GSO_TCPV6; |
| 571 | break; |
| 572 | case VIRTIO_NET_HDR_GSO_UDP: |
| 573 | pr_warn_once("macvtap: %s: using disabled UFO feature; please fix this program\n", |
| 574 | current->comm); |
| 575 | gso_type = SKB_GSO_UDP; |
| 576 | if (skb->protocol == htons(ETH_P_IPV6)) |
| 577 | ipv6_proxy_select_ident(skb); |
| 578 | break; |
| 579 | default: |
| 580 | return -EINVAL; |
| 581 | } |
| 582 | |
| 583 | if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) |
| 584 | gso_type |= SKB_GSO_TCP_ECN; |
| 585 | |
| 586 | if (vnet_hdr->gso_size == 0) |
| 587 | return -EINVAL; |
| 588 | } |
| 589 | |
| 590 | if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { |
| 591 | if (!skb_partial_csum_set(skb, vnet_hdr->csum_start, |
| 592 | vnet_hdr->csum_offset)) |
| 593 | return -EINVAL; |
| 594 | } |
| 595 | |
| 596 | if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { |
| 597 | skb_shinfo(skb)->gso_size = vnet_hdr->gso_size; |
| 598 | skb_shinfo(skb)->gso_type = gso_type; |
| 599 | |
| 600 | /* Header must be checked, and gso_segs computed. */ |
| 601 | skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; |
| 602 | skb_shinfo(skb)->gso_segs = 0; |
| 603 | } |
| 604 | return 0; |
| 605 | } |
| 606 | |
| 607 | static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb, |
| 608 | struct virtio_net_hdr *vnet_hdr) |
| 609 | { |
| 610 | memset(vnet_hdr, 0, sizeof(*vnet_hdr)); |
| 611 | |
| 612 | if (skb_is_gso(skb)) { |
| 613 | struct skb_shared_info *sinfo = skb_shinfo(skb); |
| 614 | |
| 615 | /* This is a hint as to how much should be linear. */ |
| 616 | vnet_hdr->hdr_len = skb_headlen(skb); |
| 617 | vnet_hdr->gso_size = sinfo->gso_size; |
| 618 | if (sinfo->gso_type & SKB_GSO_TCPV4) |
| 619 | vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; |
| 620 | else if (sinfo->gso_type & SKB_GSO_TCPV6) |
| 621 | vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; |
| 622 | else |
| 623 | BUG(); |
| 624 | if (sinfo->gso_type & SKB_GSO_TCP_ECN) |
| 625 | vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; |
| 626 | } else |
| 627 | vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; |
| 628 | |
| 629 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
| 630 | vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; |
| 631 | vnet_hdr->csum_start = skb_checksum_start_offset(skb); |
| 632 | if (vlan_tx_tag_present(skb)) |
| 633 | vnet_hdr->csum_start += VLAN_HLEN; |
| 634 | vnet_hdr->csum_offset = skb->csum_offset; |
| 635 | } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { |
| 636 | vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID; |
| 637 | } /* else everything is zero */ |
| 638 | } |
| 639 | |
| 640 | /* Get packet from user space buffer */ |
| 641 | static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, |
| 642 | const struct iovec *iv, unsigned long total_len, |
| 643 | size_t count, int noblock) |
| 644 | { |
| 645 | int good_linear = SKB_MAX_HEAD(NET_IP_ALIGN); |
| 646 | struct sk_buff *skb; |
| 647 | struct macvlan_dev *vlan; |
| 648 | unsigned long len = total_len; |
| 649 | int err; |
| 650 | struct virtio_net_hdr vnet_hdr = { 0 }; |
| 651 | int vnet_hdr_len = 0; |
| 652 | int copylen = 0; |
| 653 | bool zerocopy = false; |
| 654 | size_t linear; |
| 655 | |
| 656 | if (q->flags & IFF_VNET_HDR) { |
| 657 | vnet_hdr_len = q->vnet_hdr_sz; |
| 658 | |
| 659 | err = -EINVAL; |
| 660 | if (len < vnet_hdr_len) |
| 661 | goto err; |
| 662 | len -= vnet_hdr_len; |
| 663 | |
| 664 | err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0, |
| 665 | sizeof(vnet_hdr)); |
| 666 | if (err < 0) |
| 667 | goto err; |
| 668 | if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && |
| 669 | vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > |
| 670 | vnet_hdr.hdr_len) |
| 671 | vnet_hdr.hdr_len = vnet_hdr.csum_start + |
| 672 | vnet_hdr.csum_offset + 2; |
| 673 | err = -EINVAL; |
| 674 | if (vnet_hdr.hdr_len > len) |
| 675 | goto err; |
| 676 | } |
| 677 | |
| 678 | err = -EINVAL; |
| 679 | if (unlikely(len < ETH_HLEN)) |
| 680 | goto err; |
| 681 | |
| 682 | err = -EMSGSIZE; |
| 683 | if (unlikely(count > UIO_MAXIOV)) |
| 684 | goto err; |
| 685 | |
| 686 | if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { |
| 687 | copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN; |
| 688 | if (copylen > good_linear) |
| 689 | copylen = good_linear; |
| 690 | linear = copylen; |
| 691 | if (iov_pages(iv, vnet_hdr_len + copylen, count) |
| 692 | <= MAX_SKB_FRAGS) |
| 693 | zerocopy = true; |
| 694 | } |
| 695 | |
| 696 | if (!zerocopy) { |
| 697 | copylen = len; |
| 698 | if (vnet_hdr.hdr_len > good_linear) |
| 699 | linear = good_linear; |
| 700 | else |
| 701 | linear = vnet_hdr.hdr_len; |
| 702 | } |
| 703 | |
| 704 | skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen, |
| 705 | linear, noblock, &err); |
| 706 | if (!skb) |
| 707 | goto err; |
| 708 | |
| 709 | if (zerocopy) |
| 710 | err = zerocopy_sg_from_iovec(skb, iv, vnet_hdr_len, count); |
| 711 | else { |
| 712 | err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len, |
| 713 | len); |
| 714 | if (!err && m && m->msg_control) { |
| 715 | struct ubuf_info *uarg = m->msg_control; |
| 716 | uarg->callback(uarg, false); |
| 717 | } |
| 718 | } |
| 719 | |
| 720 | if (err) |
| 721 | goto err_kfree; |
| 722 | |
| 723 | skb_set_network_header(skb, ETH_HLEN); |
| 724 | skb_reset_mac_header(skb); |
| 725 | skb->protocol = eth_hdr(skb)->h_proto; |
| 726 | |
| 727 | if (vnet_hdr_len) { |
| 728 | err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr); |
| 729 | if (err) |
| 730 | goto err_kfree; |
| 731 | } |
| 732 | |
| 733 | skb_probe_transport_header(skb, ETH_HLEN); |
| 734 | |
| 735 | rcu_read_lock(); |
| 736 | vlan = rcu_dereference(q->vlan); |
| 737 | /* copy skb_ubuf_info for callback when skb has no error */ |
| 738 | if (zerocopy) { |
| 739 | skb_shinfo(skb)->destructor_arg = m->msg_control; |
| 740 | skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; |
| 741 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; |
| 742 | } |
| 743 | if (vlan) { |
| 744 | skb->dev = vlan->dev; |
| 745 | dev_queue_xmit(skb); |
| 746 | } else { |
| 747 | kfree_skb(skb); |
| 748 | } |
| 749 | rcu_read_unlock(); |
| 750 | |
| 751 | return total_len; |
| 752 | |
| 753 | err_kfree: |
| 754 | kfree_skb(skb); |
| 755 | |
| 756 | err: |
| 757 | rcu_read_lock(); |
| 758 | vlan = rcu_dereference(q->vlan); |
| 759 | if (vlan) |
| 760 | this_cpu_inc(vlan->pcpu_stats->tx_dropped); |
| 761 | rcu_read_unlock(); |
| 762 | |
| 763 | return err; |
| 764 | } |
| 765 | |
| 766 | static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv, |
| 767 | unsigned long count, loff_t pos) |
| 768 | { |
| 769 | struct file *file = iocb->ki_filp; |
| 770 | ssize_t result = -ENOLINK; |
| 771 | struct macvtap_queue *q = file->private_data; |
| 772 | |
| 773 | result = macvtap_get_user(q, NULL, iv, iov_length(iv, count), count, |
| 774 | file->f_flags & O_NONBLOCK); |
| 775 | return result; |
| 776 | } |
| 777 | |
| 778 | /* Put packet to the user space buffer */ |
| 779 | static ssize_t macvtap_put_user(struct macvtap_queue *q, |
| 780 | const struct sk_buff *skb, |
| 781 | const struct iovec *iv, int len) |
| 782 | { |
| 783 | int ret; |
| 784 | int vnet_hdr_len = 0; |
| 785 | int vlan_offset = 0; |
| 786 | int copied, total; |
| 787 | |
| 788 | if (q->flags & IFF_VNET_HDR) { |
| 789 | struct virtio_net_hdr vnet_hdr; |
| 790 | vnet_hdr_len = q->vnet_hdr_sz; |
| 791 | if ((len -= vnet_hdr_len) < 0) |
| 792 | return -EINVAL; |
| 793 | |
| 794 | macvtap_skb_to_vnet_hdr(skb, &vnet_hdr); |
| 795 | |
| 796 | if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr))) |
| 797 | return -EFAULT; |
| 798 | } |
| 799 | total = copied = vnet_hdr_len; |
| 800 | total += skb->len; |
| 801 | |
| 802 | if (!vlan_tx_tag_present(skb)) |
| 803 | len = min_t(int, skb->len, len); |
| 804 | else { |
| 805 | int copy; |
| 806 | struct { |
| 807 | __be16 h_vlan_proto; |
| 808 | __be16 h_vlan_TCI; |
| 809 | } veth; |
| 810 | veth.h_vlan_proto = skb->vlan_proto; |
| 811 | veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb)); |
| 812 | |
| 813 | vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); |
| 814 | len = min_t(int, skb->len + VLAN_HLEN, len); |
| 815 | total += VLAN_HLEN; |
| 816 | |
| 817 | copy = min_t(int, vlan_offset, len); |
| 818 | ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy); |
| 819 | len -= copy; |
| 820 | copied += copy; |
| 821 | if (ret || !len) |
| 822 | goto done; |
| 823 | |
| 824 | copy = min_t(int, sizeof(veth), len); |
| 825 | ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy); |
| 826 | len -= copy; |
| 827 | copied += copy; |
| 828 | if (ret || !len) |
| 829 | goto done; |
| 830 | } |
| 831 | |
| 832 | ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len); |
| 833 | |
| 834 | done: |
| 835 | return ret ? ret : total; |
| 836 | } |
| 837 | |
| 838 | static ssize_t macvtap_do_read(struct macvtap_queue *q, |
| 839 | const struct iovec *iv, unsigned long len, |
| 840 | int noblock) |
| 841 | { |
| 842 | DEFINE_WAIT(wait); |
| 843 | struct sk_buff *skb; |
| 844 | ssize_t ret = 0; |
| 845 | |
| 846 | while (len) { |
| 847 | if (!noblock) |
| 848 | prepare_to_wait(sk_sleep(&q->sk), &wait, |
| 849 | TASK_INTERRUPTIBLE); |
| 850 | |
| 851 | /* Read frames from the queue */ |
| 852 | skb = skb_dequeue(&q->sk.sk_receive_queue); |
| 853 | if (!skb) { |
| 854 | if (noblock) { |
| 855 | ret = -EAGAIN; |
| 856 | break; |
| 857 | } |
| 858 | if (signal_pending(current)) { |
| 859 | ret = -ERESTARTSYS; |
| 860 | break; |
| 861 | } |
| 862 | /* Nothing to read, let's sleep */ |
| 863 | schedule(); |
| 864 | continue; |
| 865 | } |
| 866 | ret = macvtap_put_user(q, skb, iv, len); |
| 867 | kfree_skb(skb); |
| 868 | break; |
| 869 | } |
| 870 | |
| 871 | if (!noblock) |
| 872 | finish_wait(sk_sleep(&q->sk), &wait); |
| 873 | return ret; |
| 874 | } |
| 875 | |
| 876 | static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv, |
| 877 | unsigned long count, loff_t pos) |
| 878 | { |
| 879 | struct file *file = iocb->ki_filp; |
| 880 | struct macvtap_queue *q = file->private_data; |
| 881 | ssize_t len, ret = 0; |
| 882 | |
| 883 | len = iov_length(iv, count); |
| 884 | if (len < 0) { |
| 885 | ret = -EINVAL; |
| 886 | goto out; |
| 887 | } |
| 888 | |
| 889 | ret = macvtap_do_read(q, iv, len, file->f_flags & O_NONBLOCK); |
| 890 | ret = min_t(ssize_t, ret, len); |
| 891 | if (ret > 0) |
| 892 | iocb->ki_pos = ret; |
| 893 | out: |
| 894 | return ret; |
| 895 | } |
| 896 | |
| 897 | static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q) |
| 898 | { |
| 899 | struct macvlan_dev *vlan; |
| 900 | |
| 901 | ASSERT_RTNL(); |
| 902 | vlan = rtnl_dereference(q->vlan); |
| 903 | if (vlan) |
| 904 | dev_hold(vlan->dev); |
| 905 | |
| 906 | return vlan; |
| 907 | } |
| 908 | |
| 909 | static void macvtap_put_vlan(struct macvlan_dev *vlan) |
| 910 | { |
| 911 | dev_put(vlan->dev); |
| 912 | } |
| 913 | |
| 914 | static int macvtap_ioctl_set_queue(struct file *file, unsigned int flags) |
| 915 | { |
| 916 | struct macvtap_queue *q = file->private_data; |
| 917 | struct macvlan_dev *vlan; |
| 918 | int ret; |
| 919 | |
| 920 | vlan = macvtap_get_vlan(q); |
| 921 | if (!vlan) |
| 922 | return -EINVAL; |
| 923 | |
| 924 | if (flags & IFF_ATTACH_QUEUE) |
| 925 | ret = macvtap_enable_queue(vlan->dev, file, q); |
| 926 | else if (flags & IFF_DETACH_QUEUE) |
| 927 | ret = macvtap_disable_queue(q); |
| 928 | else |
| 929 | ret = -EINVAL; |
| 930 | |
| 931 | macvtap_put_vlan(vlan); |
| 932 | return ret; |
| 933 | } |
| 934 | |
| 935 | static int set_offload(struct macvtap_queue *q, unsigned long arg) |
| 936 | { |
| 937 | struct macvlan_dev *vlan; |
| 938 | netdev_features_t features; |
| 939 | netdev_features_t feature_mask = 0; |
| 940 | |
| 941 | vlan = rtnl_dereference(q->vlan); |
| 942 | if (!vlan) |
| 943 | return -ENOLINK; |
| 944 | |
| 945 | features = vlan->dev->features; |
| 946 | |
| 947 | if (arg & TUN_F_CSUM) { |
| 948 | feature_mask = NETIF_F_HW_CSUM; |
| 949 | |
| 950 | if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) { |
| 951 | if (arg & TUN_F_TSO_ECN) |
| 952 | feature_mask |= NETIF_F_TSO_ECN; |
| 953 | if (arg & TUN_F_TSO4) |
| 954 | feature_mask |= NETIF_F_TSO; |
| 955 | if (arg & TUN_F_TSO6) |
| 956 | feature_mask |= NETIF_F_TSO6; |
| 957 | } |
| 958 | } |
| 959 | |
| 960 | /* tun/tap driver inverts the usage for TSO offloads, where |
| 961 | * setting the TSO bit means that the userspace wants to |
| 962 | * accept TSO frames and turning it off means that user space |
| 963 | * does not support TSO. |
| 964 | * For macvtap, we have to invert it to mean the same thing. |
| 965 | * When user space turns off TSO, we turn off GSO/LRO so that |
| 966 | * user-space will not receive TSO frames. |
| 967 | */ |
| 968 | if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6)) |
| 969 | features |= RX_OFFLOADS; |
| 970 | else |
| 971 | features &= ~RX_OFFLOADS; |
| 972 | |
| 973 | /* tap_features are the same as features on tun/tap and |
| 974 | * reflect user expectations. |
| 975 | */ |
| 976 | vlan->tap_features = feature_mask; |
| 977 | vlan->set_features = features; |
| 978 | netdev_update_features(vlan->dev); |
| 979 | |
| 980 | return 0; |
| 981 | } |
| 982 | |
| 983 | /* |
| 984 | * provide compatibility with generic tun/tap interface |
| 985 | */ |
| 986 | static long macvtap_ioctl(struct file *file, unsigned int cmd, |
| 987 | unsigned long arg) |
| 988 | { |
| 989 | struct macvtap_queue *q = file->private_data; |
| 990 | struct macvlan_dev *vlan; |
| 991 | void __user *argp = (void __user *)arg; |
| 992 | struct ifreq __user *ifr = argp; |
| 993 | unsigned int __user *up = argp; |
| 994 | unsigned int u; |
| 995 | int __user *sp = argp; |
| 996 | int s; |
| 997 | int ret; |
| 998 | |
| 999 | switch (cmd) { |
| 1000 | case TUNSETIFF: |
| 1001 | /* ignore the name, just look at flags */ |
| 1002 | if (get_user(u, &ifr->ifr_flags)) |
| 1003 | return -EFAULT; |
| 1004 | |
| 1005 | ret = 0; |
| 1006 | if ((u & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) != |
| 1007 | (IFF_NO_PI | IFF_TAP)) |
| 1008 | ret = -EINVAL; |
| 1009 | else |
| 1010 | q->flags = u; |
| 1011 | |
| 1012 | return ret; |
| 1013 | |
| 1014 | case TUNGETIFF: |
| 1015 | rtnl_lock(); |
| 1016 | vlan = macvtap_get_vlan(q); |
| 1017 | if (!vlan) { |
| 1018 | rtnl_unlock(); |
| 1019 | return -ENOLINK; |
| 1020 | } |
| 1021 | |
| 1022 | ret = 0; |
| 1023 | if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) || |
| 1024 | put_user(q->flags, &ifr->ifr_flags)) |
| 1025 | ret = -EFAULT; |
| 1026 | macvtap_put_vlan(vlan); |
| 1027 | rtnl_unlock(); |
| 1028 | return ret; |
| 1029 | |
| 1030 | case TUNSETQUEUE: |
| 1031 | if (get_user(u, &ifr->ifr_flags)) |
| 1032 | return -EFAULT; |
| 1033 | rtnl_lock(); |
| 1034 | ret = macvtap_ioctl_set_queue(file, u); |
| 1035 | rtnl_unlock(); |
| 1036 | return ret; |
| 1037 | |
| 1038 | case TUNGETFEATURES: |
| 1039 | if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR | |
| 1040 | IFF_MULTI_QUEUE, up)) |
| 1041 | return -EFAULT; |
| 1042 | return 0; |
| 1043 | |
| 1044 | case TUNSETSNDBUF: |
| 1045 | if (get_user(u, up)) |
| 1046 | return -EFAULT; |
| 1047 | |
| 1048 | q->sk.sk_sndbuf = u; |
| 1049 | return 0; |
| 1050 | |
| 1051 | case TUNGETVNETHDRSZ: |
| 1052 | s = q->vnet_hdr_sz; |
| 1053 | if (put_user(s, sp)) |
| 1054 | return -EFAULT; |
| 1055 | return 0; |
| 1056 | |
| 1057 | case TUNSETVNETHDRSZ: |
| 1058 | if (get_user(s, sp)) |
| 1059 | return -EFAULT; |
| 1060 | if (s < (int)sizeof(struct virtio_net_hdr)) |
| 1061 | return -EINVAL; |
| 1062 | |
| 1063 | q->vnet_hdr_sz = s; |
| 1064 | return 0; |
| 1065 | |
| 1066 | case TUNSETOFFLOAD: |
| 1067 | /* let the user check for future flags */ |
| 1068 | if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | |
| 1069 | TUN_F_TSO_ECN)) |
| 1070 | return -EINVAL; |
| 1071 | |
| 1072 | rtnl_lock(); |
| 1073 | ret = set_offload(q, arg); |
| 1074 | rtnl_unlock(); |
| 1075 | return ret; |
| 1076 | |
| 1077 | default: |
| 1078 | return -EINVAL; |
| 1079 | } |
| 1080 | } |
| 1081 | |
| 1082 | #ifdef CONFIG_COMPAT |
| 1083 | static long macvtap_compat_ioctl(struct file *file, unsigned int cmd, |
| 1084 | unsigned long arg) |
| 1085 | { |
| 1086 | return macvtap_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
| 1087 | } |
| 1088 | #endif |
| 1089 | |
| 1090 | static const struct file_operations macvtap_fops = { |
| 1091 | .owner = THIS_MODULE, |
| 1092 | .open = macvtap_open, |
| 1093 | .release = macvtap_release, |
| 1094 | .aio_read = macvtap_aio_read, |
| 1095 | .aio_write = macvtap_aio_write, |
| 1096 | .poll = macvtap_poll, |
| 1097 | .llseek = no_llseek, |
| 1098 | .unlocked_ioctl = macvtap_ioctl, |
| 1099 | #ifdef CONFIG_COMPAT |
| 1100 | .compat_ioctl = macvtap_compat_ioctl, |
| 1101 | #endif |
| 1102 | }; |
| 1103 | |
| 1104 | static int macvtap_sendmsg(struct kiocb *iocb, struct socket *sock, |
| 1105 | struct msghdr *m, size_t total_len) |
| 1106 | { |
| 1107 | struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock); |
| 1108 | return macvtap_get_user(q, m, m->msg_iov, total_len, m->msg_iovlen, |
| 1109 | m->msg_flags & MSG_DONTWAIT); |
| 1110 | } |
| 1111 | |
| 1112 | static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock, |
| 1113 | struct msghdr *m, size_t total_len, |
| 1114 | int flags) |
| 1115 | { |
| 1116 | struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock); |
| 1117 | int ret; |
| 1118 | if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) |
| 1119 | return -EINVAL; |
| 1120 | ret = macvtap_do_read(q, m->msg_iov, total_len, |
| 1121 | flags & MSG_DONTWAIT); |
| 1122 | if (ret > total_len) { |
| 1123 | m->msg_flags |= MSG_TRUNC; |
| 1124 | ret = flags & MSG_TRUNC ? ret : total_len; |
| 1125 | } |
| 1126 | return ret; |
| 1127 | } |
| 1128 | |
| 1129 | /* Ops structure to mimic raw sockets with tun */ |
| 1130 | static const struct proto_ops macvtap_socket_ops = { |
| 1131 | .sendmsg = macvtap_sendmsg, |
| 1132 | .recvmsg = macvtap_recvmsg, |
| 1133 | }; |
| 1134 | |
| 1135 | /* Get an underlying socket object from tun file. Returns error unless file is |
| 1136 | * attached to a device. The returned object works like a packet socket, it |
| 1137 | * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for |
| 1138 | * holding a reference to the file for as long as the socket is in use. */ |
| 1139 | struct socket *macvtap_get_socket(struct file *file) |
| 1140 | { |
| 1141 | struct macvtap_queue *q; |
| 1142 | if (file->f_op != &macvtap_fops) |
| 1143 | return ERR_PTR(-EINVAL); |
| 1144 | q = file->private_data; |
| 1145 | if (!q) |
| 1146 | return ERR_PTR(-EBADFD); |
| 1147 | return &q->sock; |
| 1148 | } |
| 1149 | EXPORT_SYMBOL_GPL(macvtap_get_socket); |
| 1150 | |
| 1151 | static int macvtap_device_event(struct notifier_block *unused, |
| 1152 | unsigned long event, void *ptr) |
| 1153 | { |
| 1154 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
| 1155 | struct macvlan_dev *vlan; |
| 1156 | struct device *classdev; |
| 1157 | dev_t devt; |
| 1158 | int err; |
| 1159 | |
| 1160 | if (dev->rtnl_link_ops != &macvtap_link_ops) |
| 1161 | return NOTIFY_DONE; |
| 1162 | |
| 1163 | vlan = netdev_priv(dev); |
| 1164 | |
| 1165 | switch (event) { |
| 1166 | case NETDEV_REGISTER: |
| 1167 | /* Create the device node here after the network device has |
| 1168 | * been registered but before register_netdevice has |
| 1169 | * finished running. |
| 1170 | */ |
| 1171 | err = macvtap_get_minor(vlan); |
| 1172 | if (err) |
| 1173 | return notifier_from_errno(err); |
| 1174 | |
| 1175 | devt = MKDEV(MAJOR(macvtap_major), vlan->minor); |
| 1176 | classdev = device_create(macvtap_class, &dev->dev, devt, |
| 1177 | dev, "tap%d", dev->ifindex); |
| 1178 | if (IS_ERR(classdev)) { |
| 1179 | macvtap_free_minor(vlan); |
| 1180 | return notifier_from_errno(PTR_ERR(classdev)); |
| 1181 | } |
| 1182 | break; |
| 1183 | case NETDEV_UNREGISTER: |
| 1184 | devt = MKDEV(MAJOR(macvtap_major), vlan->minor); |
| 1185 | device_destroy(macvtap_class, devt); |
| 1186 | macvtap_free_minor(vlan); |
| 1187 | break; |
| 1188 | } |
| 1189 | |
| 1190 | return NOTIFY_DONE; |
| 1191 | } |
| 1192 | |
| 1193 | static struct notifier_block macvtap_notifier_block __read_mostly = { |
| 1194 | .notifier_call = macvtap_device_event, |
| 1195 | }; |
| 1196 | |
| 1197 | static int macvtap_init(void) |
| 1198 | { |
| 1199 | int err; |
| 1200 | |
| 1201 | err = alloc_chrdev_region(&macvtap_major, 0, |
| 1202 | MACVTAP_NUM_DEVS, "macvtap"); |
| 1203 | if (err) |
| 1204 | goto out1; |
| 1205 | |
| 1206 | cdev_init(&macvtap_cdev, &macvtap_fops); |
| 1207 | err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS); |
| 1208 | if (err) |
| 1209 | goto out2; |
| 1210 | |
| 1211 | macvtap_class = class_create(THIS_MODULE, "macvtap"); |
| 1212 | if (IS_ERR(macvtap_class)) { |
| 1213 | err = PTR_ERR(macvtap_class); |
| 1214 | goto out3; |
| 1215 | } |
| 1216 | |
| 1217 | err = register_netdevice_notifier(&macvtap_notifier_block); |
| 1218 | if (err) |
| 1219 | goto out4; |
| 1220 | |
| 1221 | err = macvlan_link_register(&macvtap_link_ops); |
| 1222 | if (err) |
| 1223 | goto out5; |
| 1224 | |
| 1225 | return 0; |
| 1226 | |
| 1227 | out5: |
| 1228 | unregister_netdevice_notifier(&macvtap_notifier_block); |
| 1229 | out4: |
| 1230 | class_unregister(macvtap_class); |
| 1231 | out3: |
| 1232 | cdev_del(&macvtap_cdev); |
| 1233 | out2: |
| 1234 | unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); |
| 1235 | out1: |
| 1236 | return err; |
| 1237 | } |
| 1238 | module_init(macvtap_init); |
| 1239 | |
| 1240 | static void macvtap_exit(void) |
| 1241 | { |
| 1242 | rtnl_link_unregister(&macvtap_link_ops); |
| 1243 | unregister_netdevice_notifier(&macvtap_notifier_block); |
| 1244 | class_unregister(macvtap_class); |
| 1245 | cdev_del(&macvtap_cdev); |
| 1246 | unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); |
| 1247 | } |
| 1248 | module_exit(macvtap_exit); |
| 1249 | |
| 1250 | MODULE_ALIAS_RTNL_LINK("macvtap"); |
| 1251 | MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); |
| 1252 | MODULE_LICENSE("GPL"); |