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 #include <linux/uio.h> 19 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 #define MACVTAP_FEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE) 49 50 #define MACVTAP_VNET_LE 0x80000000 51 #define MACVTAP_VNET_BE 0x40000000 52 53 #ifdef CONFIG_TUN_VNET_CROSS_LE 54 static inline bool macvtap_legacy_is_little_endian(struct macvtap_queue *q) 55 { 56 return q->flags & MACVTAP_VNET_BE ? false : 57 virtio_legacy_is_little_endian(); 58 } 59 60 static long macvtap_get_vnet_be(struct macvtap_queue *q, int __user *sp) 61 { 62 int s = !!(q->flags & MACVTAP_VNET_BE); 63 64 if (put_user(s, sp)) 65 return -EFAULT; 66 67 return 0; 68 } 69 70 static long macvtap_set_vnet_be(struct macvtap_queue *q, int __user *sp) 71 { 72 int s; 73 74 if (get_user(s, sp)) 75 return -EFAULT; 76 77 if (s) 78 q->flags |= MACVTAP_VNET_BE; 79 else 80 q->flags &= ~MACVTAP_VNET_BE; 81 82 return 0; 83 } 84 #else 85 static inline bool macvtap_legacy_is_little_endian(struct macvtap_queue *q) 86 { 87 return virtio_legacy_is_little_endian(); 88 } 89 90 static long macvtap_get_vnet_be(struct macvtap_queue *q, int __user *argp) 91 { 92 return -EINVAL; 93 } 94 95 static long macvtap_set_vnet_be(struct macvtap_queue *q, int __user *argp) 96 { 97 return -EINVAL; 98 } 99 #endif /* CONFIG_TUN_VNET_CROSS_LE */ 100 101 static inline bool macvtap_is_little_endian(struct macvtap_queue *q) 102 { 103 return q->flags & MACVTAP_VNET_LE || 104 macvtap_legacy_is_little_endian(q); 105 } 106 107 static inline u16 macvtap16_to_cpu(struct macvtap_queue *q, __virtio16 val) 108 { 109 return __virtio16_to_cpu(macvtap_is_little_endian(q), val); 110 } 111 112 static inline __virtio16 cpu_to_macvtap16(struct macvtap_queue *q, u16 val) 113 { 114 return __cpu_to_virtio16(macvtap_is_little_endian(q), val); 115 } 116 117 static struct proto macvtap_proto = { 118 .name = "macvtap", 119 .owner = THIS_MODULE, 120 .obj_size = sizeof (struct macvtap_queue), 121 }; 122 123 /* 124 * Variables for dealing with macvtaps device numbers. 125 */ 126 static dev_t macvtap_major; 127 #define MACVTAP_NUM_DEVS (1U << MINORBITS) 128 static DEFINE_MUTEX(minor_lock); 129 static DEFINE_IDR(minor_idr); 130 131 #define GOODCOPY_LEN 128 132 static const void *macvtap_net_namespace(struct device *d) 133 { 134 struct net_device *dev = to_net_dev(d->parent); 135 return dev_net(dev); 136 } 137 138 static struct class macvtap_class = { 139 .name = "macvtap", 140 .owner = THIS_MODULE, 141 .ns_type = &net_ns_type_operations, 142 .namespace = macvtap_net_namespace, 143 }; 144 static struct cdev macvtap_cdev; 145 146 static const struct proto_ops macvtap_socket_ops; 147 148 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \ 149 NETIF_F_TSO6 | NETIF_F_UFO) 150 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO) 151 #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG | NETIF_F_FRAGLIST) 152 153 static struct macvlan_dev *macvtap_get_vlan_rcu(const struct net_device *dev) 154 { 155 return rcu_dereference(dev->rx_handler_data); 156 } 157 158 /* 159 * RCU usage: 160 * The macvtap_queue and the macvlan_dev are loosely coupled, the 161 * pointers from one to the other can only be read while rcu_read_lock 162 * or rtnl is held. 163 * 164 * Both the file and the macvlan_dev hold a reference on the macvtap_queue 165 * through sock_hold(&q->sk). When the macvlan_dev goes away first, 166 * q->vlan becomes inaccessible. When the files gets closed, 167 * macvtap_get_queue() fails. 168 * 169 * There may still be references to the struct sock inside of the 170 * queue from outbound SKBs, but these never reference back to the 171 * file or the dev. The data structure is freed through __sk_free 172 * when both our references and any pending SKBs are gone. 173 */ 174 175 static int macvtap_enable_queue(struct net_device *dev, struct file *file, 176 struct macvtap_queue *q) 177 { 178 struct macvlan_dev *vlan = netdev_priv(dev); 179 int err = -EINVAL; 180 181 ASSERT_RTNL(); 182 183 if (q->enabled) 184 goto out; 185 186 err = 0; 187 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q); 188 q->queue_index = vlan->numvtaps; 189 q->enabled = true; 190 191 vlan->numvtaps++; 192 out: 193 return err; 194 } 195 196 /* Requires RTNL */ 197 static int macvtap_set_queue(struct net_device *dev, struct file *file, 198 struct macvtap_queue *q) 199 { 200 struct macvlan_dev *vlan = netdev_priv(dev); 201 202 if (vlan->numqueues == MAX_MACVTAP_QUEUES) 203 return -EBUSY; 204 205 rcu_assign_pointer(q->vlan, vlan); 206 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q); 207 sock_hold(&q->sk); 208 209 q->file = file; 210 q->queue_index = vlan->numvtaps; 211 q->enabled = true; 212 file->private_data = q; 213 list_add_tail(&q->next, &vlan->queue_list); 214 215 vlan->numvtaps++; 216 vlan->numqueues++; 217 218 return 0; 219 } 220 221 static int macvtap_disable_queue(struct macvtap_queue *q) 222 { 223 struct macvlan_dev *vlan; 224 struct macvtap_queue *nq; 225 226 ASSERT_RTNL(); 227 if (!q->enabled) 228 return -EINVAL; 229 230 vlan = rtnl_dereference(q->vlan); 231 232 if (vlan) { 233 int index = q->queue_index; 234 BUG_ON(index >= vlan->numvtaps); 235 nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]); 236 nq->queue_index = index; 237 238 rcu_assign_pointer(vlan->taps[index], nq); 239 RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL); 240 q->enabled = false; 241 242 vlan->numvtaps--; 243 } 244 245 return 0; 246 } 247 248 /* 249 * The file owning the queue got closed, give up both 250 * the reference that the files holds as well as the 251 * one from the macvlan_dev if that still exists. 252 * 253 * Using the spinlock makes sure that we don't get 254 * to the queue again after destroying it. 255 */ 256 static void macvtap_put_queue(struct macvtap_queue *q) 257 { 258 struct macvlan_dev *vlan; 259 260 rtnl_lock(); 261 vlan = rtnl_dereference(q->vlan); 262 263 if (vlan) { 264 if (q->enabled) 265 BUG_ON(macvtap_disable_queue(q)); 266 267 vlan->numqueues--; 268 RCU_INIT_POINTER(q->vlan, NULL); 269 sock_put(&q->sk); 270 list_del_init(&q->next); 271 } 272 273 rtnl_unlock(); 274 275 synchronize_rcu(); 276 sock_put(&q->sk); 277 } 278 279 /* 280 * Select a queue based on the rxq of the device on which this packet 281 * arrived. If the incoming device is not mq, calculate a flow hash 282 * to select a queue. If all fails, find the first available queue. 283 * Cache vlan->numvtaps since it can become zero during the execution 284 * of this function. 285 */ 286 static struct macvtap_queue *macvtap_get_queue(struct net_device *dev, 287 struct sk_buff *skb) 288 { 289 struct macvlan_dev *vlan = netdev_priv(dev); 290 struct macvtap_queue *tap = NULL; 291 /* Access to taps array is protected by rcu, but access to numvtaps 292 * isn't. Below we use it to lookup a queue, but treat it as a hint 293 * and validate that the result isn't NULL - in case we are 294 * racing against queue removal. 295 */ 296 int numvtaps = ACCESS_ONCE(vlan->numvtaps); 297 __u32 rxq; 298 299 if (!numvtaps) 300 goto out; 301 302 /* Check if we can use flow to select a queue */ 303 rxq = skb_get_hash(skb); 304 if (rxq) { 305 tap = rcu_dereference(vlan->taps[rxq % numvtaps]); 306 goto out; 307 } 308 309 if (likely(skb_rx_queue_recorded(skb))) { 310 rxq = skb_get_rx_queue(skb); 311 312 while (unlikely(rxq >= numvtaps)) 313 rxq -= numvtaps; 314 315 tap = rcu_dereference(vlan->taps[rxq]); 316 goto out; 317 } 318 319 tap = rcu_dereference(vlan->taps[0]); 320 out: 321 return tap; 322 } 323 324 /* 325 * The net_device is going away, give up the reference 326 * that it holds on all queues and safely set the pointer 327 * from the queues to NULL. 328 */ 329 static void macvtap_del_queues(struct net_device *dev) 330 { 331 struct macvlan_dev *vlan = netdev_priv(dev); 332 struct macvtap_queue *q, *tmp; 333 334 ASSERT_RTNL(); 335 list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) { 336 list_del_init(&q->next); 337 RCU_INIT_POINTER(q->vlan, NULL); 338 if (q->enabled) 339 vlan->numvtaps--; 340 vlan->numqueues--; 341 sock_put(&q->sk); 342 } 343 BUG_ON(vlan->numvtaps); 344 BUG_ON(vlan->numqueues); 345 /* guarantee that any future macvtap_set_queue will fail */ 346 vlan->numvtaps = MAX_MACVTAP_QUEUES; 347 } 348 349 static rx_handler_result_t macvtap_handle_frame(struct sk_buff **pskb) 350 { 351 struct sk_buff *skb = *pskb; 352 struct net_device *dev = skb->dev; 353 struct macvlan_dev *vlan; 354 struct macvtap_queue *q; 355 netdev_features_t features = TAP_FEATURES; 356 357 vlan = macvtap_get_vlan_rcu(dev); 358 if (!vlan) 359 return RX_HANDLER_PASS; 360 361 q = macvtap_get_queue(dev, skb); 362 if (!q) 363 return RX_HANDLER_PASS; 364 365 if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len) 366 goto drop; 367 368 skb_push(skb, ETH_HLEN); 369 370 /* Apply the forward feature mask so that we perform segmentation 371 * according to users wishes. This only works if VNET_HDR is 372 * enabled. 373 */ 374 if (q->flags & IFF_VNET_HDR) 375 features |= vlan->tap_features; 376 if (netif_needs_gso(skb, features)) { 377 struct sk_buff *segs = __skb_gso_segment(skb, features, false); 378 379 if (IS_ERR(segs)) 380 goto drop; 381 382 if (!segs) { 383 skb_queue_tail(&q->sk.sk_receive_queue, skb); 384 goto wake_up; 385 } 386 387 consume_skb(skb); 388 while (segs) { 389 struct sk_buff *nskb = segs->next; 390 391 segs->next = NULL; 392 skb_queue_tail(&q->sk.sk_receive_queue, segs); 393 segs = nskb; 394 } 395 } else { 396 /* If we receive a partial checksum and the tap side 397 * doesn't support checksum offload, compute the checksum. 398 * Note: it doesn't matter which checksum feature to 399 * check, we either support them all or none. 400 */ 401 if (skb->ip_summed == CHECKSUM_PARTIAL && 402 !(features & NETIF_F_CSUM_MASK) && 403 skb_checksum_help(skb)) 404 goto drop; 405 skb_queue_tail(&q->sk.sk_receive_queue, skb); 406 } 407 408 wake_up: 409 wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND); 410 return RX_HANDLER_CONSUMED; 411 412 drop: 413 /* Count errors/drops only here, thus don't care about args. */ 414 macvlan_count_rx(vlan, 0, 0, 0); 415 kfree_skb(skb); 416 return RX_HANDLER_CONSUMED; 417 } 418 419 static int macvtap_get_minor(struct macvlan_dev *vlan) 420 { 421 int retval = -ENOMEM; 422 423 mutex_lock(&minor_lock); 424 retval = idr_alloc(&minor_idr, vlan, 1, MACVTAP_NUM_DEVS, GFP_KERNEL); 425 if (retval >= 0) { 426 vlan->minor = retval; 427 } else if (retval == -ENOSPC) { 428 printk(KERN_ERR "too many macvtap devices\n"); 429 retval = -EINVAL; 430 } 431 mutex_unlock(&minor_lock); 432 return retval < 0 ? retval : 0; 433 } 434 435 static void macvtap_free_minor(struct macvlan_dev *vlan) 436 { 437 mutex_lock(&minor_lock); 438 if (vlan->minor) { 439 idr_remove(&minor_idr, vlan->minor); 440 vlan->minor = 0; 441 } 442 mutex_unlock(&minor_lock); 443 } 444 445 static struct net_device *dev_get_by_macvtap_minor(int minor) 446 { 447 struct net_device *dev = NULL; 448 struct macvlan_dev *vlan; 449 450 mutex_lock(&minor_lock); 451 vlan = idr_find(&minor_idr, minor); 452 if (vlan) { 453 dev = vlan->dev; 454 dev_hold(dev); 455 } 456 mutex_unlock(&minor_lock); 457 return dev; 458 } 459 460 static int macvtap_newlink(struct net *src_net, 461 struct net_device *dev, 462 struct nlattr *tb[], 463 struct nlattr *data[]) 464 { 465 struct macvlan_dev *vlan = netdev_priv(dev); 466 int err; 467 468 INIT_LIST_HEAD(&vlan->queue_list); 469 470 /* Since macvlan supports all offloads by default, make 471 * tap support all offloads also. 472 */ 473 vlan->tap_features = TUN_OFFLOADS; 474 475 err = netdev_rx_handler_register(dev, macvtap_handle_frame, vlan); 476 if (err) 477 return err; 478 479 /* Don't put anything that may fail after macvlan_common_newlink 480 * because we can't undo what it does. 481 */ 482 return macvlan_common_newlink(src_net, dev, tb, data); 483 } 484 485 static void macvtap_dellink(struct net_device *dev, 486 struct list_head *head) 487 { 488 netdev_rx_handler_unregister(dev); 489 macvtap_del_queues(dev); 490 macvlan_dellink(dev, head); 491 } 492 493 static void macvtap_setup(struct net_device *dev) 494 { 495 macvlan_common_setup(dev); 496 dev->tx_queue_len = TUN_READQ_SIZE; 497 } 498 499 static struct rtnl_link_ops macvtap_link_ops __read_mostly = { 500 .kind = "macvtap", 501 .setup = macvtap_setup, 502 .newlink = macvtap_newlink, 503 .dellink = macvtap_dellink, 504 }; 505 506 507 static void macvtap_sock_write_space(struct sock *sk) 508 { 509 wait_queue_head_t *wqueue; 510 511 if (!sock_writeable(sk) || 512 !test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)) 513 return; 514 515 wqueue = sk_sleep(sk); 516 if (wqueue && waitqueue_active(wqueue)) 517 wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND); 518 } 519 520 static void macvtap_sock_destruct(struct sock *sk) 521 { 522 skb_queue_purge(&sk->sk_receive_queue); 523 } 524 525 static int macvtap_open(struct inode *inode, struct file *file) 526 { 527 struct net *net = current->nsproxy->net_ns; 528 struct net_device *dev; 529 struct macvtap_queue *q; 530 int err = -ENODEV; 531 532 rtnl_lock(); 533 dev = dev_get_by_macvtap_minor(iminor(inode)); 534 if (!dev) 535 goto out; 536 537 err = -ENOMEM; 538 q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, 539 &macvtap_proto, 0); 540 if (!q) 541 goto out; 542 543 RCU_INIT_POINTER(q->sock.wq, &q->wq); 544 init_waitqueue_head(&q->wq.wait); 545 q->sock.type = SOCK_RAW; 546 q->sock.state = SS_CONNECTED; 547 q->sock.file = file; 548 q->sock.ops = &macvtap_socket_ops; 549 sock_init_data(&q->sock, &q->sk); 550 q->sk.sk_write_space = macvtap_sock_write_space; 551 q->sk.sk_destruct = macvtap_sock_destruct; 552 q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; 553 q->vnet_hdr_sz = sizeof(struct virtio_net_hdr); 554 555 /* 556 * so far only KVM virtio_net uses macvtap, enable zero copy between 557 * guest kernel and host kernel when lower device supports zerocopy 558 * 559 * The macvlan supports zerocopy iff the lower device supports zero 560 * copy so we don't have to look at the lower device directly. 561 */ 562 if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG)) 563 sock_set_flag(&q->sk, SOCK_ZEROCOPY); 564 565 err = macvtap_set_queue(dev, file, q); 566 if (err) 567 sock_put(&q->sk); 568 569 out: 570 if (dev) 571 dev_put(dev); 572 573 rtnl_unlock(); 574 return err; 575 } 576 577 static int macvtap_release(struct inode *inode, struct file *file) 578 { 579 struct macvtap_queue *q = file->private_data; 580 macvtap_put_queue(q); 581 return 0; 582 } 583 584 static unsigned int macvtap_poll(struct file *file, poll_table * wait) 585 { 586 struct macvtap_queue *q = file->private_data; 587 unsigned int mask = POLLERR; 588 589 if (!q) 590 goto out; 591 592 mask = 0; 593 poll_wait(file, &q->wq.wait, wait); 594 595 if (!skb_queue_empty(&q->sk.sk_receive_queue)) 596 mask |= POLLIN | POLLRDNORM; 597 598 if (sock_writeable(&q->sk) || 599 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &q->sock.flags) && 600 sock_writeable(&q->sk))) 601 mask |= POLLOUT | POLLWRNORM; 602 603 out: 604 return mask; 605 } 606 607 static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad, 608 size_t len, size_t linear, 609 int noblock, int *err) 610 { 611 struct sk_buff *skb; 612 613 /* Under a page? Don't bother with paged skb. */ 614 if (prepad + len < PAGE_SIZE || !linear) 615 linear = len; 616 617 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 618 err, 0); 619 if (!skb) 620 return NULL; 621 622 skb_reserve(skb, prepad); 623 skb_put(skb, linear); 624 skb->data_len = len - linear; 625 skb->len += len - linear; 626 627 return skb; 628 } 629 630 /* 631 * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should 632 * be shared with the tun/tap driver. 633 */ 634 static int macvtap_skb_from_vnet_hdr(struct macvtap_queue *q, 635 struct sk_buff *skb, 636 struct virtio_net_hdr *vnet_hdr) 637 { 638 unsigned short gso_type = 0; 639 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { 640 switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 641 case VIRTIO_NET_HDR_GSO_TCPV4: 642 gso_type = SKB_GSO_TCPV4; 643 break; 644 case VIRTIO_NET_HDR_GSO_TCPV6: 645 gso_type = SKB_GSO_TCPV6; 646 break; 647 case VIRTIO_NET_HDR_GSO_UDP: 648 gso_type = SKB_GSO_UDP; 649 break; 650 default: 651 return -EINVAL; 652 } 653 654 if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) 655 gso_type |= SKB_GSO_TCP_ECN; 656 657 if (vnet_hdr->gso_size == 0) 658 return -EINVAL; 659 } 660 661 if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 662 if (!skb_partial_csum_set(skb, macvtap16_to_cpu(q, vnet_hdr->csum_start), 663 macvtap16_to_cpu(q, vnet_hdr->csum_offset))) 664 return -EINVAL; 665 } 666 667 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { 668 skb_shinfo(skb)->gso_size = macvtap16_to_cpu(q, vnet_hdr->gso_size); 669 skb_shinfo(skb)->gso_type = gso_type; 670 671 /* Header must be checked, and gso_segs computed. */ 672 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 673 skb_shinfo(skb)->gso_segs = 0; 674 } 675 return 0; 676 } 677 678 static void macvtap_skb_to_vnet_hdr(struct macvtap_queue *q, 679 const struct sk_buff *skb, 680 struct virtio_net_hdr *vnet_hdr) 681 { 682 memset(vnet_hdr, 0, sizeof(*vnet_hdr)); 683 684 if (skb_is_gso(skb)) { 685 struct skb_shared_info *sinfo = skb_shinfo(skb); 686 687 /* This is a hint as to how much should be linear. */ 688 vnet_hdr->hdr_len = cpu_to_macvtap16(q, skb_headlen(skb)); 689 vnet_hdr->gso_size = cpu_to_macvtap16(q, sinfo->gso_size); 690 if (sinfo->gso_type & SKB_GSO_TCPV4) 691 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; 692 else if (sinfo->gso_type & SKB_GSO_TCPV6) 693 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; 694 else if (sinfo->gso_type & SKB_GSO_UDP) 695 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP; 696 else 697 BUG(); 698 if (sinfo->gso_type & SKB_GSO_TCP_ECN) 699 vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; 700 } else 701 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; 702 703 if (skb->ip_summed == CHECKSUM_PARTIAL) { 704 vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 705 if (skb_vlan_tag_present(skb)) 706 vnet_hdr->csum_start = cpu_to_macvtap16(q, 707 skb_checksum_start_offset(skb) + VLAN_HLEN); 708 else 709 vnet_hdr->csum_start = cpu_to_macvtap16(q, 710 skb_checksum_start_offset(skb)); 711 vnet_hdr->csum_offset = cpu_to_macvtap16(q, skb->csum_offset); 712 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 713 vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID; 714 } /* else everything is zero */ 715 } 716 717 /* Neighbour code has some assumptions on HH_DATA_MOD alignment */ 718 #define MACVTAP_RESERVE HH_DATA_OFF(ETH_HLEN) 719 720 /* Get packet from user space buffer */ 721 static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, 722 struct iov_iter *from, int noblock) 723 { 724 int good_linear = SKB_MAX_HEAD(MACVTAP_RESERVE); 725 struct sk_buff *skb; 726 struct macvlan_dev *vlan; 727 unsigned long total_len = iov_iter_count(from); 728 unsigned long len = total_len; 729 int err; 730 struct virtio_net_hdr vnet_hdr = { 0 }; 731 int vnet_hdr_len = 0; 732 int copylen = 0; 733 int depth; 734 bool zerocopy = false; 735 size_t linear; 736 ssize_t n; 737 738 if (q->flags & IFF_VNET_HDR) { 739 vnet_hdr_len = q->vnet_hdr_sz; 740 741 err = -EINVAL; 742 if (len < vnet_hdr_len) 743 goto err; 744 len -= vnet_hdr_len; 745 746 err = -EFAULT; 747 n = copy_from_iter(&vnet_hdr, sizeof(vnet_hdr), from); 748 if (n != sizeof(vnet_hdr)) 749 goto err; 750 iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr)); 751 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 752 macvtap16_to_cpu(q, vnet_hdr.csum_start) + 753 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2 > 754 macvtap16_to_cpu(q, vnet_hdr.hdr_len)) 755 vnet_hdr.hdr_len = cpu_to_macvtap16(q, 756 macvtap16_to_cpu(q, vnet_hdr.csum_start) + 757 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2); 758 err = -EINVAL; 759 if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > len) 760 goto err; 761 } 762 763 err = -EINVAL; 764 if (unlikely(len < ETH_HLEN)) 765 goto err; 766 767 if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { 768 struct iov_iter i; 769 770 copylen = vnet_hdr.hdr_len ? 771 macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN; 772 if (copylen > good_linear) 773 copylen = good_linear; 774 else if (copylen < ETH_HLEN) 775 copylen = ETH_HLEN; 776 linear = copylen; 777 i = *from; 778 iov_iter_advance(&i, copylen); 779 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS) 780 zerocopy = true; 781 } 782 783 if (!zerocopy) { 784 copylen = len; 785 linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len); 786 if (linear > good_linear) 787 linear = good_linear; 788 else if (linear < ETH_HLEN) 789 linear = ETH_HLEN; 790 } 791 792 skb = macvtap_alloc_skb(&q->sk, MACVTAP_RESERVE, copylen, 793 linear, noblock, &err); 794 if (!skb) 795 goto err; 796 797 if (zerocopy) 798 err = zerocopy_sg_from_iter(skb, from); 799 else { 800 err = skb_copy_datagram_from_iter(skb, 0, from, len); 801 if (!err && m && m->msg_control) { 802 struct ubuf_info *uarg = m->msg_control; 803 uarg->callback(uarg, false); 804 } 805 } 806 807 if (err) 808 goto err_kfree; 809 810 skb_set_network_header(skb, ETH_HLEN); 811 skb_reset_mac_header(skb); 812 skb->protocol = eth_hdr(skb)->h_proto; 813 814 if (vnet_hdr_len) { 815 err = macvtap_skb_from_vnet_hdr(q, skb, &vnet_hdr); 816 if (err) 817 goto err_kfree; 818 } 819 820 skb_probe_transport_header(skb, ETH_HLEN); 821 822 /* Move network header to the right position for VLAN tagged packets */ 823 if ((skb->protocol == htons(ETH_P_8021Q) || 824 skb->protocol == htons(ETH_P_8021AD)) && 825 __vlan_get_protocol(skb, skb->protocol, &depth) != 0) 826 skb_set_network_header(skb, depth); 827 828 rcu_read_lock(); 829 vlan = rcu_dereference(q->vlan); 830 /* copy skb_ubuf_info for callback when skb has no error */ 831 if (zerocopy) { 832 skb_shinfo(skb)->destructor_arg = m->msg_control; 833 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; 834 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; 835 } 836 if (vlan) { 837 skb->dev = vlan->dev; 838 dev_queue_xmit(skb); 839 } else { 840 kfree_skb(skb); 841 } 842 rcu_read_unlock(); 843 844 return total_len; 845 846 err_kfree: 847 kfree_skb(skb); 848 849 err: 850 rcu_read_lock(); 851 vlan = rcu_dereference(q->vlan); 852 if (vlan) 853 this_cpu_inc(vlan->pcpu_stats->tx_dropped); 854 rcu_read_unlock(); 855 856 return err; 857 } 858 859 static ssize_t macvtap_write_iter(struct kiocb *iocb, struct iov_iter *from) 860 { 861 struct file *file = iocb->ki_filp; 862 struct macvtap_queue *q = file->private_data; 863 864 return macvtap_get_user(q, NULL, from, file->f_flags & O_NONBLOCK); 865 } 866 867 /* Put packet to the user space buffer */ 868 static ssize_t macvtap_put_user(struct macvtap_queue *q, 869 const struct sk_buff *skb, 870 struct iov_iter *iter) 871 { 872 int ret; 873 int vnet_hdr_len = 0; 874 int vlan_offset = 0; 875 int total; 876 877 if (q->flags & IFF_VNET_HDR) { 878 struct virtio_net_hdr vnet_hdr; 879 vnet_hdr_len = q->vnet_hdr_sz; 880 if (iov_iter_count(iter) < vnet_hdr_len) 881 return -EINVAL; 882 883 macvtap_skb_to_vnet_hdr(q, skb, &vnet_hdr); 884 885 if (copy_to_iter(&vnet_hdr, sizeof(vnet_hdr), iter) != 886 sizeof(vnet_hdr)) 887 return -EFAULT; 888 889 iov_iter_advance(iter, vnet_hdr_len - sizeof(vnet_hdr)); 890 } 891 total = vnet_hdr_len; 892 total += skb->len; 893 894 if (skb_vlan_tag_present(skb)) { 895 struct { 896 __be16 h_vlan_proto; 897 __be16 h_vlan_TCI; 898 } veth; 899 veth.h_vlan_proto = skb->vlan_proto; 900 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb)); 901 902 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); 903 total += VLAN_HLEN; 904 905 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset); 906 if (ret || !iov_iter_count(iter)) 907 goto done; 908 909 ret = copy_to_iter(&veth, sizeof(veth), iter); 910 if (ret != sizeof(veth) || !iov_iter_count(iter)) 911 goto done; 912 } 913 914 ret = skb_copy_datagram_iter(skb, vlan_offset, iter, 915 skb->len - vlan_offset); 916 917 done: 918 return ret ? ret : total; 919 } 920 921 static ssize_t macvtap_do_read(struct macvtap_queue *q, 922 struct iov_iter *to, 923 int noblock) 924 { 925 DEFINE_WAIT(wait); 926 struct sk_buff *skb; 927 ssize_t ret = 0; 928 929 if (!iov_iter_count(to)) 930 return 0; 931 932 while (1) { 933 if (!noblock) 934 prepare_to_wait(sk_sleep(&q->sk), &wait, 935 TASK_INTERRUPTIBLE); 936 937 /* Read frames from the queue */ 938 skb = skb_dequeue(&q->sk.sk_receive_queue); 939 if (skb) 940 break; 941 if (noblock) { 942 ret = -EAGAIN; 943 break; 944 } 945 if (signal_pending(current)) { 946 ret = -ERESTARTSYS; 947 break; 948 } 949 /* Nothing to read, let's sleep */ 950 schedule(); 951 } 952 if (!noblock) 953 finish_wait(sk_sleep(&q->sk), &wait); 954 955 if (skb) { 956 ret = macvtap_put_user(q, skb, to); 957 if (unlikely(ret < 0)) 958 kfree_skb(skb); 959 else 960 consume_skb(skb); 961 } 962 return ret; 963 } 964 965 static ssize_t macvtap_read_iter(struct kiocb *iocb, struct iov_iter *to) 966 { 967 struct file *file = iocb->ki_filp; 968 struct macvtap_queue *q = file->private_data; 969 ssize_t len = iov_iter_count(to), ret; 970 971 ret = macvtap_do_read(q, to, file->f_flags & O_NONBLOCK); 972 ret = min_t(ssize_t, ret, len); 973 if (ret > 0) 974 iocb->ki_pos = ret; 975 return ret; 976 } 977 978 static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q) 979 { 980 struct macvlan_dev *vlan; 981 982 ASSERT_RTNL(); 983 vlan = rtnl_dereference(q->vlan); 984 if (vlan) 985 dev_hold(vlan->dev); 986 987 return vlan; 988 } 989 990 static void macvtap_put_vlan(struct macvlan_dev *vlan) 991 { 992 dev_put(vlan->dev); 993 } 994 995 static int macvtap_ioctl_set_queue(struct file *file, unsigned int flags) 996 { 997 struct macvtap_queue *q = file->private_data; 998 struct macvlan_dev *vlan; 999 int ret; 1000 1001 vlan = macvtap_get_vlan(q); 1002 if (!vlan) 1003 return -EINVAL; 1004 1005 if (flags & IFF_ATTACH_QUEUE) 1006 ret = macvtap_enable_queue(vlan->dev, file, q); 1007 else if (flags & IFF_DETACH_QUEUE) 1008 ret = macvtap_disable_queue(q); 1009 else 1010 ret = -EINVAL; 1011 1012 macvtap_put_vlan(vlan); 1013 return ret; 1014 } 1015 1016 static int set_offload(struct macvtap_queue *q, unsigned long arg) 1017 { 1018 struct macvlan_dev *vlan; 1019 netdev_features_t features; 1020 netdev_features_t feature_mask = 0; 1021 1022 vlan = rtnl_dereference(q->vlan); 1023 if (!vlan) 1024 return -ENOLINK; 1025 1026 features = vlan->dev->features; 1027 1028 if (arg & TUN_F_CSUM) { 1029 feature_mask = NETIF_F_HW_CSUM; 1030 1031 if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) { 1032 if (arg & TUN_F_TSO_ECN) 1033 feature_mask |= NETIF_F_TSO_ECN; 1034 if (arg & TUN_F_TSO4) 1035 feature_mask |= NETIF_F_TSO; 1036 if (arg & TUN_F_TSO6) 1037 feature_mask |= NETIF_F_TSO6; 1038 } 1039 1040 if (arg & TUN_F_UFO) 1041 feature_mask |= NETIF_F_UFO; 1042 } 1043 1044 /* tun/tap driver inverts the usage for TSO offloads, where 1045 * setting the TSO bit means that the userspace wants to 1046 * accept TSO frames and turning it off means that user space 1047 * does not support TSO. 1048 * For macvtap, we have to invert it to mean the same thing. 1049 * When user space turns off TSO, we turn off GSO/LRO so that 1050 * user-space will not receive TSO frames. 1051 */ 1052 if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_UFO)) 1053 features |= RX_OFFLOADS; 1054 else 1055 features &= ~RX_OFFLOADS; 1056 1057 /* tap_features are the same as features on tun/tap and 1058 * reflect user expectations. 1059 */ 1060 vlan->tap_features = feature_mask; 1061 vlan->set_features = features; 1062 netdev_update_features(vlan->dev); 1063 1064 return 0; 1065 } 1066 1067 /* 1068 * provide compatibility with generic tun/tap interface 1069 */ 1070 static long macvtap_ioctl(struct file *file, unsigned int cmd, 1071 unsigned long arg) 1072 { 1073 struct macvtap_queue *q = file->private_data; 1074 struct macvlan_dev *vlan; 1075 void __user *argp = (void __user *)arg; 1076 struct ifreq __user *ifr = argp; 1077 unsigned int __user *up = argp; 1078 unsigned short u; 1079 int __user *sp = argp; 1080 struct sockaddr sa; 1081 int s; 1082 int ret; 1083 1084 switch (cmd) { 1085 case TUNSETIFF: 1086 /* ignore the name, just look at flags */ 1087 if (get_user(u, &ifr->ifr_flags)) 1088 return -EFAULT; 1089 1090 ret = 0; 1091 if ((u & ~MACVTAP_FEATURES) != (IFF_NO_PI | IFF_TAP)) 1092 ret = -EINVAL; 1093 else 1094 q->flags = (q->flags & ~MACVTAP_FEATURES) | u; 1095 1096 return ret; 1097 1098 case TUNGETIFF: 1099 rtnl_lock(); 1100 vlan = macvtap_get_vlan(q); 1101 if (!vlan) { 1102 rtnl_unlock(); 1103 return -ENOLINK; 1104 } 1105 1106 ret = 0; 1107 u = q->flags; 1108 if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) || 1109 put_user(u, &ifr->ifr_flags)) 1110 ret = -EFAULT; 1111 macvtap_put_vlan(vlan); 1112 rtnl_unlock(); 1113 return ret; 1114 1115 case TUNSETQUEUE: 1116 if (get_user(u, &ifr->ifr_flags)) 1117 return -EFAULT; 1118 rtnl_lock(); 1119 ret = macvtap_ioctl_set_queue(file, u); 1120 rtnl_unlock(); 1121 return ret; 1122 1123 case TUNGETFEATURES: 1124 if (put_user(IFF_TAP | IFF_NO_PI | MACVTAP_FEATURES, up)) 1125 return -EFAULT; 1126 return 0; 1127 1128 case TUNSETSNDBUF: 1129 if (get_user(s, sp)) 1130 return -EFAULT; 1131 1132 q->sk.sk_sndbuf = s; 1133 return 0; 1134 1135 case TUNGETVNETHDRSZ: 1136 s = q->vnet_hdr_sz; 1137 if (put_user(s, sp)) 1138 return -EFAULT; 1139 return 0; 1140 1141 case TUNSETVNETHDRSZ: 1142 if (get_user(s, sp)) 1143 return -EFAULT; 1144 if (s < (int)sizeof(struct virtio_net_hdr)) 1145 return -EINVAL; 1146 1147 q->vnet_hdr_sz = s; 1148 return 0; 1149 1150 case TUNGETVNETLE: 1151 s = !!(q->flags & MACVTAP_VNET_LE); 1152 if (put_user(s, sp)) 1153 return -EFAULT; 1154 return 0; 1155 1156 case TUNSETVNETLE: 1157 if (get_user(s, sp)) 1158 return -EFAULT; 1159 if (s) 1160 q->flags |= MACVTAP_VNET_LE; 1161 else 1162 q->flags &= ~MACVTAP_VNET_LE; 1163 return 0; 1164 1165 case TUNGETVNETBE: 1166 return macvtap_get_vnet_be(q, sp); 1167 1168 case TUNSETVNETBE: 1169 return macvtap_set_vnet_be(q, sp); 1170 1171 case TUNSETOFFLOAD: 1172 /* let the user check for future flags */ 1173 if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | 1174 TUN_F_TSO_ECN | TUN_F_UFO)) 1175 return -EINVAL; 1176 1177 rtnl_lock(); 1178 ret = set_offload(q, arg); 1179 rtnl_unlock(); 1180 return ret; 1181 1182 case SIOCGIFHWADDR: 1183 rtnl_lock(); 1184 vlan = macvtap_get_vlan(q); 1185 if (!vlan) { 1186 rtnl_unlock(); 1187 return -ENOLINK; 1188 } 1189 ret = 0; 1190 u = vlan->dev->type; 1191 if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) || 1192 copy_to_user(&ifr->ifr_hwaddr.sa_data, vlan->dev->dev_addr, ETH_ALEN) || 1193 put_user(u, &ifr->ifr_hwaddr.sa_family)) 1194 ret = -EFAULT; 1195 macvtap_put_vlan(vlan); 1196 rtnl_unlock(); 1197 return ret; 1198 1199 case SIOCSIFHWADDR: 1200 if (copy_from_user(&sa, &ifr->ifr_hwaddr, sizeof(sa))) 1201 return -EFAULT; 1202 rtnl_lock(); 1203 vlan = macvtap_get_vlan(q); 1204 if (!vlan) { 1205 rtnl_unlock(); 1206 return -ENOLINK; 1207 } 1208 ret = dev_set_mac_address(vlan->dev, &sa); 1209 macvtap_put_vlan(vlan); 1210 rtnl_unlock(); 1211 return ret; 1212 1213 default: 1214 return -EINVAL; 1215 } 1216 } 1217 1218 #ifdef CONFIG_COMPAT 1219 static long macvtap_compat_ioctl(struct file *file, unsigned int cmd, 1220 unsigned long arg) 1221 { 1222 return macvtap_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 1223 } 1224 #endif 1225 1226 static const struct file_operations macvtap_fops = { 1227 .owner = THIS_MODULE, 1228 .open = macvtap_open, 1229 .release = macvtap_release, 1230 .read_iter = macvtap_read_iter, 1231 .write_iter = macvtap_write_iter, 1232 .poll = macvtap_poll, 1233 .llseek = no_llseek, 1234 .unlocked_ioctl = macvtap_ioctl, 1235 #ifdef CONFIG_COMPAT 1236 .compat_ioctl = macvtap_compat_ioctl, 1237 #endif 1238 }; 1239 1240 static int macvtap_sendmsg(struct socket *sock, struct msghdr *m, 1241 size_t total_len) 1242 { 1243 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock); 1244 return macvtap_get_user(q, m, &m->msg_iter, m->msg_flags & MSG_DONTWAIT); 1245 } 1246 1247 static int macvtap_recvmsg(struct socket *sock, struct msghdr *m, 1248 size_t total_len, int flags) 1249 { 1250 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock); 1251 int ret; 1252 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) 1253 return -EINVAL; 1254 ret = macvtap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT); 1255 if (ret > total_len) { 1256 m->msg_flags |= MSG_TRUNC; 1257 ret = flags & MSG_TRUNC ? ret : total_len; 1258 } 1259 return ret; 1260 } 1261 1262 /* Ops structure to mimic raw sockets with tun */ 1263 static const struct proto_ops macvtap_socket_ops = { 1264 .sendmsg = macvtap_sendmsg, 1265 .recvmsg = macvtap_recvmsg, 1266 }; 1267 1268 /* Get an underlying socket object from tun file. Returns error unless file is 1269 * attached to a device. The returned object works like a packet socket, it 1270 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for 1271 * holding a reference to the file for as long as the socket is in use. */ 1272 struct socket *macvtap_get_socket(struct file *file) 1273 { 1274 struct macvtap_queue *q; 1275 if (file->f_op != &macvtap_fops) 1276 return ERR_PTR(-EINVAL); 1277 q = file->private_data; 1278 if (!q) 1279 return ERR_PTR(-EBADFD); 1280 return &q->sock; 1281 } 1282 EXPORT_SYMBOL_GPL(macvtap_get_socket); 1283 1284 static int macvtap_device_event(struct notifier_block *unused, 1285 unsigned long event, void *ptr) 1286 { 1287 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1288 struct macvlan_dev *vlan; 1289 struct device *classdev; 1290 dev_t devt; 1291 int err; 1292 char tap_name[IFNAMSIZ]; 1293 1294 if (dev->rtnl_link_ops != &macvtap_link_ops) 1295 return NOTIFY_DONE; 1296 1297 snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex); 1298 vlan = netdev_priv(dev); 1299 1300 switch (event) { 1301 case NETDEV_REGISTER: 1302 /* Create the device node here after the network device has 1303 * been registered but before register_netdevice has 1304 * finished running. 1305 */ 1306 err = macvtap_get_minor(vlan); 1307 if (err) 1308 return notifier_from_errno(err); 1309 1310 devt = MKDEV(MAJOR(macvtap_major), vlan->minor); 1311 classdev = device_create(&macvtap_class, &dev->dev, devt, 1312 dev, tap_name); 1313 if (IS_ERR(classdev)) { 1314 macvtap_free_minor(vlan); 1315 return notifier_from_errno(PTR_ERR(classdev)); 1316 } 1317 err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj, 1318 tap_name); 1319 if (err) 1320 return notifier_from_errno(err); 1321 break; 1322 case NETDEV_UNREGISTER: 1323 /* vlan->minor == 0 if NETDEV_REGISTER above failed */ 1324 if (vlan->minor == 0) 1325 break; 1326 sysfs_remove_link(&dev->dev.kobj, tap_name); 1327 devt = MKDEV(MAJOR(macvtap_major), vlan->minor); 1328 device_destroy(&macvtap_class, devt); 1329 macvtap_free_minor(vlan); 1330 break; 1331 } 1332 1333 return NOTIFY_DONE; 1334 } 1335 1336 static struct notifier_block macvtap_notifier_block __read_mostly = { 1337 .notifier_call = macvtap_device_event, 1338 }; 1339 1340 static int macvtap_init(void) 1341 { 1342 int err; 1343 1344 err = alloc_chrdev_region(&macvtap_major, 0, 1345 MACVTAP_NUM_DEVS, "macvtap"); 1346 if (err) 1347 goto out1; 1348 1349 cdev_init(&macvtap_cdev, &macvtap_fops); 1350 err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS); 1351 if (err) 1352 goto out2; 1353 1354 err = class_register(&macvtap_class); 1355 if (err) 1356 goto out3; 1357 1358 err = register_netdevice_notifier(&macvtap_notifier_block); 1359 if (err) 1360 goto out4; 1361 1362 err = macvlan_link_register(&macvtap_link_ops); 1363 if (err) 1364 goto out5; 1365 1366 return 0; 1367 1368 out5: 1369 unregister_netdevice_notifier(&macvtap_notifier_block); 1370 out4: 1371 class_unregister(&macvtap_class); 1372 out3: 1373 cdev_del(&macvtap_cdev); 1374 out2: 1375 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); 1376 out1: 1377 return err; 1378 } 1379 module_init(macvtap_init); 1380 1381 static void macvtap_exit(void) 1382 { 1383 rtnl_link_unregister(&macvtap_link_ops); 1384 unregister_netdevice_notifier(&macvtap_notifier_block); 1385 class_unregister(&macvtap_class); 1386 cdev_del(&macvtap_cdev); 1387 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); 1388 idr_destroy(&minor_idr); 1389 } 1390 module_exit(macvtap_exit); 1391 1392 MODULE_ALIAS_RTNL_LINK("macvtap"); 1393 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); 1394 MODULE_LICENSE("GPL"); 1395