1a8e04698SSainath Grandhi #include <linux/etherdevice.h> 26fe3faf8SSainath Grandhi #include <linux/if_tap.h> 3a8e04698SSainath Grandhi #include <linux/if_vlan.h> 4a8e04698SSainath Grandhi #include <linux/interrupt.h> 5a8e04698SSainath Grandhi #include <linux/nsproxy.h> 6a8e04698SSainath Grandhi #include <linux/compat.h> 7a8e04698SSainath Grandhi #include <linux/if_tun.h> 8a8e04698SSainath Grandhi #include <linux/module.h> 9a8e04698SSainath Grandhi #include <linux/skbuff.h> 10a8e04698SSainath Grandhi #include <linux/cache.h> 11a8e04698SSainath Grandhi #include <linux/sched.h> 12a8e04698SSainath Grandhi #include <linux/types.h> 13a8e04698SSainath Grandhi #include <linux/slab.h> 14a8e04698SSainath Grandhi #include <linux/wait.h> 15a8e04698SSainath Grandhi #include <linux/cdev.h> 16a8e04698SSainath Grandhi #include <linux/idr.h> 17a8e04698SSainath Grandhi #include <linux/fs.h> 18a8e04698SSainath Grandhi #include <linux/uio.h> 19a8e04698SSainath Grandhi 20a8e04698SSainath Grandhi #include <net/net_namespace.h> 21a8e04698SSainath Grandhi #include <net/rtnetlink.h> 22a8e04698SSainath Grandhi #include <net/sock.h> 23a8e04698SSainath Grandhi #include <linux/virtio_net.h> 24a8e04698SSainath Grandhi #include <linux/skb_array.h> 25a8e04698SSainath Grandhi 26635b8c8eSSainath Grandhi #define TAP_IFFEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE) 27a8e04698SSainath Grandhi 28635b8c8eSSainath Grandhi #define TAP_VNET_LE 0x80000000 29635b8c8eSSainath Grandhi #define TAP_VNET_BE 0x40000000 30a8e04698SSainath Grandhi 31a8e04698SSainath Grandhi #ifdef CONFIG_TUN_VNET_CROSS_LE 32635b8c8eSSainath Grandhi static inline bool tap_legacy_is_little_endian(struct tap_queue *q) 33a8e04698SSainath Grandhi { 34635b8c8eSSainath Grandhi return q->flags & TAP_VNET_BE ? false : 35a8e04698SSainath Grandhi virtio_legacy_is_little_endian(); 36a8e04698SSainath Grandhi } 37a8e04698SSainath Grandhi 38635b8c8eSSainath Grandhi static long tap_get_vnet_be(struct tap_queue *q, int __user *sp) 39a8e04698SSainath Grandhi { 40635b8c8eSSainath Grandhi int s = !!(q->flags & TAP_VNET_BE); 41a8e04698SSainath Grandhi 42a8e04698SSainath Grandhi if (put_user(s, sp)) 43a8e04698SSainath Grandhi return -EFAULT; 44a8e04698SSainath Grandhi 45a8e04698SSainath Grandhi return 0; 46a8e04698SSainath Grandhi } 47a8e04698SSainath Grandhi 48635b8c8eSSainath Grandhi static long tap_set_vnet_be(struct tap_queue *q, int __user *sp) 49a8e04698SSainath Grandhi { 50a8e04698SSainath Grandhi int s; 51a8e04698SSainath Grandhi 52a8e04698SSainath Grandhi if (get_user(s, sp)) 53a8e04698SSainath Grandhi return -EFAULT; 54a8e04698SSainath Grandhi 55a8e04698SSainath Grandhi if (s) 56635b8c8eSSainath Grandhi q->flags |= TAP_VNET_BE; 57a8e04698SSainath Grandhi else 58635b8c8eSSainath Grandhi q->flags &= ~TAP_VNET_BE; 59a8e04698SSainath Grandhi 60a8e04698SSainath Grandhi return 0; 61a8e04698SSainath Grandhi } 62a8e04698SSainath Grandhi #else 63635b8c8eSSainath Grandhi static inline bool tap_legacy_is_little_endian(struct tap_queue *q) 64a8e04698SSainath Grandhi { 65a8e04698SSainath Grandhi return virtio_legacy_is_little_endian(); 66a8e04698SSainath Grandhi } 67a8e04698SSainath Grandhi 68635b8c8eSSainath Grandhi static long tap_get_vnet_be(struct tap_queue *q, int __user *argp) 69a8e04698SSainath Grandhi { 70a8e04698SSainath Grandhi return -EINVAL; 71a8e04698SSainath Grandhi } 72a8e04698SSainath Grandhi 73635b8c8eSSainath Grandhi static long tap_set_vnet_be(struct tap_queue *q, int __user *argp) 74a8e04698SSainath Grandhi { 75a8e04698SSainath Grandhi return -EINVAL; 76a8e04698SSainath Grandhi } 77a8e04698SSainath Grandhi #endif /* CONFIG_TUN_VNET_CROSS_LE */ 78a8e04698SSainath Grandhi 79635b8c8eSSainath Grandhi static inline bool tap_is_little_endian(struct tap_queue *q) 80a8e04698SSainath Grandhi { 81635b8c8eSSainath Grandhi return q->flags & TAP_VNET_LE || 82635b8c8eSSainath Grandhi tap_legacy_is_little_endian(q); 83a8e04698SSainath Grandhi } 84a8e04698SSainath Grandhi 85635b8c8eSSainath Grandhi static inline u16 tap16_to_cpu(struct tap_queue *q, __virtio16 val) 86a8e04698SSainath Grandhi { 87635b8c8eSSainath Grandhi return __virtio16_to_cpu(tap_is_little_endian(q), val); 88a8e04698SSainath Grandhi } 89a8e04698SSainath Grandhi 90635b8c8eSSainath Grandhi static inline __virtio16 cpu_to_tap16(struct tap_queue *q, u16 val) 91a8e04698SSainath Grandhi { 92635b8c8eSSainath Grandhi return __cpu_to_virtio16(tap_is_little_endian(q), val); 93a8e04698SSainath Grandhi } 94a8e04698SSainath Grandhi 95635b8c8eSSainath Grandhi static struct proto tap_proto = { 96635b8c8eSSainath Grandhi .name = "tap", 97a8e04698SSainath Grandhi .owner = THIS_MODULE, 98635b8c8eSSainath Grandhi .obj_size = sizeof(struct tap_queue), 99a8e04698SSainath Grandhi }; 100a8e04698SSainath Grandhi 101635b8c8eSSainath Grandhi #define TAP_NUM_DEVS (1U << MINORBITS) 102*d9f1f61cSSainath Grandhi 103*d9f1f61cSSainath Grandhi static LIST_HEAD(major_list); 104*d9f1f61cSSainath Grandhi 105ebc05ba7SSainath Grandhi struct major_info { 106*d9f1f61cSSainath Grandhi struct rcu_head rcu; 107ebc05ba7SSainath Grandhi dev_t major; 108ebc05ba7SSainath Grandhi struct idr minor_idr; 109ebc05ba7SSainath Grandhi struct mutex minor_lock; 110ebc05ba7SSainath Grandhi const char *device_name; 111*d9f1f61cSSainath Grandhi struct list_head next; 112*d9f1f61cSSainath Grandhi }; 113a8e04698SSainath Grandhi 114a8e04698SSainath Grandhi #define GOODCOPY_LEN 128 115a8e04698SSainath Grandhi 116635b8c8eSSainath Grandhi static const struct proto_ops tap_socket_ops; 117a8e04698SSainath Grandhi 118a8e04698SSainath Grandhi #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO) 119a8e04698SSainath Grandhi #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG | NETIF_F_FRAGLIST) 120a8e04698SSainath Grandhi 1216fe3faf8SSainath Grandhi static struct tap_dev *tap_dev_get_rcu(const struct net_device *dev) 122a8e04698SSainath Grandhi { 123a8e04698SSainath Grandhi return rcu_dereference(dev->rx_handler_data); 124a8e04698SSainath Grandhi } 125a8e04698SSainath Grandhi 126a8e04698SSainath Grandhi /* 127a8e04698SSainath Grandhi * RCU usage: 128635b8c8eSSainath Grandhi * The tap_queue and the macvlan_dev are loosely coupled, the 129a8e04698SSainath Grandhi * pointers from one to the other can only be read while rcu_read_lock 130a8e04698SSainath Grandhi * or rtnl is held. 131a8e04698SSainath Grandhi * 132635b8c8eSSainath Grandhi * Both the file and the macvlan_dev hold a reference on the tap_queue 133a8e04698SSainath Grandhi * through sock_hold(&q->sk). When the macvlan_dev goes away first, 134a8e04698SSainath Grandhi * q->vlan becomes inaccessible. When the files gets closed, 135635b8c8eSSainath Grandhi * tap_get_queue() fails. 136a8e04698SSainath Grandhi * 137a8e04698SSainath Grandhi * There may still be references to the struct sock inside of the 138a8e04698SSainath Grandhi * queue from outbound SKBs, but these never reference back to the 139a8e04698SSainath Grandhi * file or the dev. The data structure is freed through __sk_free 140a8e04698SSainath Grandhi * when both our references and any pending SKBs are gone. 141a8e04698SSainath Grandhi */ 142a8e04698SSainath Grandhi 1436fe3faf8SSainath Grandhi static int tap_enable_queue(struct tap_dev *tap, struct file *file, 144635b8c8eSSainath Grandhi struct tap_queue *q) 145a8e04698SSainath Grandhi { 146a8e04698SSainath Grandhi int err = -EINVAL; 147a8e04698SSainath Grandhi 148a8e04698SSainath Grandhi ASSERT_RTNL(); 149a8e04698SSainath Grandhi 150a8e04698SSainath Grandhi if (q->enabled) 151a8e04698SSainath Grandhi goto out; 152a8e04698SSainath Grandhi 153a8e04698SSainath Grandhi err = 0; 1546fe3faf8SSainath Grandhi rcu_assign_pointer(tap->taps[tap->numvtaps], q); 1556fe3faf8SSainath Grandhi q->queue_index = tap->numvtaps; 156a8e04698SSainath Grandhi q->enabled = true; 157a8e04698SSainath Grandhi 1586fe3faf8SSainath Grandhi tap->numvtaps++; 159a8e04698SSainath Grandhi out: 160a8e04698SSainath Grandhi return err; 161a8e04698SSainath Grandhi } 162a8e04698SSainath Grandhi 163a8e04698SSainath Grandhi /* Requires RTNL */ 1646fe3faf8SSainath Grandhi static int tap_set_queue(struct tap_dev *tap, struct file *file, 165635b8c8eSSainath Grandhi struct tap_queue *q) 166a8e04698SSainath Grandhi { 1676fe3faf8SSainath Grandhi if (tap->numqueues == MAX_TAP_QUEUES) 168a8e04698SSainath Grandhi return -EBUSY; 169a8e04698SSainath Grandhi 1706fe3faf8SSainath Grandhi rcu_assign_pointer(q->tap, tap); 1716fe3faf8SSainath Grandhi rcu_assign_pointer(tap->taps[tap->numvtaps], q); 172a8e04698SSainath Grandhi sock_hold(&q->sk); 173a8e04698SSainath Grandhi 174a8e04698SSainath Grandhi q->file = file; 1756fe3faf8SSainath Grandhi q->queue_index = tap->numvtaps; 176a8e04698SSainath Grandhi q->enabled = true; 177a8e04698SSainath Grandhi file->private_data = q; 1786fe3faf8SSainath Grandhi list_add_tail(&q->next, &tap->queue_list); 179a8e04698SSainath Grandhi 1806fe3faf8SSainath Grandhi tap->numvtaps++; 1816fe3faf8SSainath Grandhi tap->numqueues++; 182a8e04698SSainath Grandhi 183a8e04698SSainath Grandhi return 0; 184a8e04698SSainath Grandhi } 185a8e04698SSainath Grandhi 186635b8c8eSSainath Grandhi static int tap_disable_queue(struct tap_queue *q) 187a8e04698SSainath Grandhi { 1886fe3faf8SSainath Grandhi struct tap_dev *tap; 189635b8c8eSSainath Grandhi struct tap_queue *nq; 190a8e04698SSainath Grandhi 191a8e04698SSainath Grandhi ASSERT_RTNL(); 192a8e04698SSainath Grandhi if (!q->enabled) 193a8e04698SSainath Grandhi return -EINVAL; 194a8e04698SSainath Grandhi 1956fe3faf8SSainath Grandhi tap = rtnl_dereference(q->tap); 196a8e04698SSainath Grandhi 1976fe3faf8SSainath Grandhi if (tap) { 198a8e04698SSainath Grandhi int index = q->queue_index; 1996fe3faf8SSainath Grandhi BUG_ON(index >= tap->numvtaps); 2006fe3faf8SSainath Grandhi nq = rtnl_dereference(tap->taps[tap->numvtaps - 1]); 201a8e04698SSainath Grandhi nq->queue_index = index; 202a8e04698SSainath Grandhi 2036fe3faf8SSainath Grandhi rcu_assign_pointer(tap->taps[index], nq); 2046fe3faf8SSainath Grandhi RCU_INIT_POINTER(tap->taps[tap->numvtaps - 1], NULL); 205a8e04698SSainath Grandhi q->enabled = false; 206a8e04698SSainath Grandhi 2076fe3faf8SSainath Grandhi tap->numvtaps--; 208a8e04698SSainath Grandhi } 209a8e04698SSainath Grandhi 210a8e04698SSainath Grandhi return 0; 211a8e04698SSainath Grandhi } 212a8e04698SSainath Grandhi 213a8e04698SSainath Grandhi /* 214a8e04698SSainath Grandhi * The file owning the queue got closed, give up both 215a8e04698SSainath Grandhi * the reference that the files holds as well as the 216a8e04698SSainath Grandhi * one from the macvlan_dev if that still exists. 217a8e04698SSainath Grandhi * 218a8e04698SSainath Grandhi * Using the spinlock makes sure that we don't get 219a8e04698SSainath Grandhi * to the queue again after destroying it. 220a8e04698SSainath Grandhi */ 221635b8c8eSSainath Grandhi static void tap_put_queue(struct tap_queue *q) 222a8e04698SSainath Grandhi { 2236fe3faf8SSainath Grandhi struct tap_dev *tap; 224a8e04698SSainath Grandhi 225a8e04698SSainath Grandhi rtnl_lock(); 2266fe3faf8SSainath Grandhi tap = rtnl_dereference(q->tap); 227a8e04698SSainath Grandhi 2286fe3faf8SSainath Grandhi if (tap) { 229a8e04698SSainath Grandhi if (q->enabled) 230635b8c8eSSainath Grandhi BUG_ON(tap_disable_queue(q)); 231a8e04698SSainath Grandhi 2326fe3faf8SSainath Grandhi tap->numqueues--; 2336fe3faf8SSainath Grandhi RCU_INIT_POINTER(q->tap, NULL); 234a8e04698SSainath Grandhi sock_put(&q->sk); 235a8e04698SSainath Grandhi list_del_init(&q->next); 236a8e04698SSainath Grandhi } 237a8e04698SSainath Grandhi 238a8e04698SSainath Grandhi rtnl_unlock(); 239a8e04698SSainath Grandhi 240a8e04698SSainath Grandhi synchronize_rcu(); 241a8e04698SSainath Grandhi sock_put(&q->sk); 242a8e04698SSainath Grandhi } 243a8e04698SSainath Grandhi 244a8e04698SSainath Grandhi /* 245a8e04698SSainath Grandhi * Select a queue based on the rxq of the device on which this packet 246a8e04698SSainath Grandhi * arrived. If the incoming device is not mq, calculate a flow hash 247a8e04698SSainath Grandhi * to select a queue. If all fails, find the first available queue. 248a8e04698SSainath Grandhi * Cache vlan->numvtaps since it can become zero during the execution 249a8e04698SSainath Grandhi * of this function. 250a8e04698SSainath Grandhi */ 2516fe3faf8SSainath Grandhi static struct tap_queue *tap_get_queue(struct tap_dev *tap, 252a8e04698SSainath Grandhi struct sk_buff *skb) 253a8e04698SSainath Grandhi { 2546fe3faf8SSainath Grandhi struct tap_queue *queue = NULL; 255a8e04698SSainath Grandhi /* Access to taps array is protected by rcu, but access to numvtaps 256a8e04698SSainath Grandhi * isn't. Below we use it to lookup a queue, but treat it as a hint 257a8e04698SSainath Grandhi * and validate that the result isn't NULL - in case we are 258a8e04698SSainath Grandhi * racing against queue removal. 259a8e04698SSainath Grandhi */ 2606fe3faf8SSainath Grandhi int numvtaps = ACCESS_ONCE(tap->numvtaps); 261a8e04698SSainath Grandhi __u32 rxq; 262a8e04698SSainath Grandhi 263a8e04698SSainath Grandhi if (!numvtaps) 264a8e04698SSainath Grandhi goto out; 265a8e04698SSainath Grandhi 266a8e04698SSainath Grandhi if (numvtaps == 1) 267a8e04698SSainath Grandhi goto single; 268a8e04698SSainath Grandhi 269a8e04698SSainath Grandhi /* Check if we can use flow to select a queue */ 270a8e04698SSainath Grandhi rxq = skb_get_hash(skb); 271a8e04698SSainath Grandhi if (rxq) { 2726fe3faf8SSainath Grandhi queue = rcu_dereference(tap->taps[rxq % numvtaps]); 273a8e04698SSainath Grandhi goto out; 274a8e04698SSainath Grandhi } 275a8e04698SSainath Grandhi 276a8e04698SSainath Grandhi if (likely(skb_rx_queue_recorded(skb))) { 277a8e04698SSainath Grandhi rxq = skb_get_rx_queue(skb); 278a8e04698SSainath Grandhi 279a8e04698SSainath Grandhi while (unlikely(rxq >= numvtaps)) 280a8e04698SSainath Grandhi rxq -= numvtaps; 281a8e04698SSainath Grandhi 2826fe3faf8SSainath Grandhi queue = rcu_dereference(tap->taps[rxq]); 283a8e04698SSainath Grandhi goto out; 284a8e04698SSainath Grandhi } 285a8e04698SSainath Grandhi 286a8e04698SSainath Grandhi single: 2876fe3faf8SSainath Grandhi queue = rcu_dereference(tap->taps[0]); 288a8e04698SSainath Grandhi out: 2896fe3faf8SSainath Grandhi return queue; 290a8e04698SSainath Grandhi } 291a8e04698SSainath Grandhi 292a8e04698SSainath Grandhi /* 293a8e04698SSainath Grandhi * The net_device is going away, give up the reference 294a8e04698SSainath Grandhi * that it holds on all queues and safely set the pointer 295a8e04698SSainath Grandhi * from the queues to NULL. 296a8e04698SSainath Grandhi */ 2976fe3faf8SSainath Grandhi void tap_del_queues(struct tap_dev *tap) 298a8e04698SSainath Grandhi { 299635b8c8eSSainath Grandhi struct tap_queue *q, *tmp; 300a8e04698SSainath Grandhi 301a8e04698SSainath Grandhi ASSERT_RTNL(); 3026fe3faf8SSainath Grandhi list_for_each_entry_safe(q, tmp, &tap->queue_list, next) { 303a8e04698SSainath Grandhi list_del_init(&q->next); 3046fe3faf8SSainath Grandhi RCU_INIT_POINTER(q->tap, NULL); 305a8e04698SSainath Grandhi if (q->enabled) 3066fe3faf8SSainath Grandhi tap->numvtaps--; 3076fe3faf8SSainath Grandhi tap->numqueues--; 308a8e04698SSainath Grandhi sock_put(&q->sk); 309a8e04698SSainath Grandhi } 3106fe3faf8SSainath Grandhi BUG_ON(tap->numvtaps); 3116fe3faf8SSainath Grandhi BUG_ON(tap->numqueues); 312635b8c8eSSainath Grandhi /* guarantee that any future tap_set_queue will fail */ 3136fe3faf8SSainath Grandhi tap->numvtaps = MAX_TAP_QUEUES; 314a8e04698SSainath Grandhi } 315a8e04698SSainath Grandhi 316635b8c8eSSainath Grandhi rx_handler_result_t tap_handle_frame(struct sk_buff **pskb) 317a8e04698SSainath Grandhi { 318a8e04698SSainath Grandhi struct sk_buff *skb = *pskb; 319a8e04698SSainath Grandhi struct net_device *dev = skb->dev; 3206fe3faf8SSainath Grandhi struct tap_dev *tap; 321635b8c8eSSainath Grandhi struct tap_queue *q; 322a8e04698SSainath Grandhi netdev_features_t features = TAP_FEATURES; 323a8e04698SSainath Grandhi 3246fe3faf8SSainath Grandhi tap = tap_dev_get_rcu(dev); 3256fe3faf8SSainath Grandhi if (!tap) 326a8e04698SSainath Grandhi return RX_HANDLER_PASS; 327a8e04698SSainath Grandhi 3286fe3faf8SSainath Grandhi q = tap_get_queue(tap, skb); 329a8e04698SSainath Grandhi if (!q) 330a8e04698SSainath Grandhi return RX_HANDLER_PASS; 331a8e04698SSainath Grandhi 332a8e04698SSainath Grandhi if (__skb_array_full(&q->skb_array)) 333a8e04698SSainath Grandhi goto drop; 334a8e04698SSainath Grandhi 335a8e04698SSainath Grandhi skb_push(skb, ETH_HLEN); 336a8e04698SSainath Grandhi 337a8e04698SSainath Grandhi /* Apply the forward feature mask so that we perform segmentation 338a8e04698SSainath Grandhi * according to users wishes. This only works if VNET_HDR is 339a8e04698SSainath Grandhi * enabled. 340a8e04698SSainath Grandhi */ 341a8e04698SSainath Grandhi if (q->flags & IFF_VNET_HDR) 3426fe3faf8SSainath Grandhi features |= tap->tap_features; 343a8e04698SSainath Grandhi if (netif_needs_gso(skb, features)) { 344a8e04698SSainath Grandhi struct sk_buff *segs = __skb_gso_segment(skb, features, false); 345a8e04698SSainath Grandhi 346a8e04698SSainath Grandhi if (IS_ERR(segs)) 347a8e04698SSainath Grandhi goto drop; 348a8e04698SSainath Grandhi 349a8e04698SSainath Grandhi if (!segs) { 350a8e04698SSainath Grandhi if (skb_array_produce(&q->skb_array, skb)) 351a8e04698SSainath Grandhi goto drop; 352a8e04698SSainath Grandhi goto wake_up; 353a8e04698SSainath Grandhi } 354a8e04698SSainath Grandhi 355a8e04698SSainath Grandhi consume_skb(skb); 356a8e04698SSainath Grandhi while (segs) { 357a8e04698SSainath Grandhi struct sk_buff *nskb = segs->next; 358a8e04698SSainath Grandhi 359a8e04698SSainath Grandhi segs->next = NULL; 360a8e04698SSainath Grandhi if (skb_array_produce(&q->skb_array, segs)) { 361a8e04698SSainath Grandhi kfree_skb(segs); 362a8e04698SSainath Grandhi kfree_skb_list(nskb); 363a8e04698SSainath Grandhi break; 364a8e04698SSainath Grandhi } 365a8e04698SSainath Grandhi segs = nskb; 366a8e04698SSainath Grandhi } 367a8e04698SSainath Grandhi } else { 368a8e04698SSainath Grandhi /* If we receive a partial checksum and the tap side 369a8e04698SSainath Grandhi * doesn't support checksum offload, compute the checksum. 370a8e04698SSainath Grandhi * Note: it doesn't matter which checksum feature to 371a8e04698SSainath Grandhi * check, we either support them all or none. 372a8e04698SSainath Grandhi */ 373a8e04698SSainath Grandhi if (skb->ip_summed == CHECKSUM_PARTIAL && 374a8e04698SSainath Grandhi !(features & NETIF_F_CSUM_MASK) && 375a8e04698SSainath Grandhi skb_checksum_help(skb)) 376a8e04698SSainath Grandhi goto drop; 377a8e04698SSainath Grandhi if (skb_array_produce(&q->skb_array, skb)) 378a8e04698SSainath Grandhi goto drop; 379a8e04698SSainath Grandhi } 380a8e04698SSainath Grandhi 381a8e04698SSainath Grandhi wake_up: 382a8e04698SSainath Grandhi wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND); 383a8e04698SSainath Grandhi return RX_HANDLER_CONSUMED; 384a8e04698SSainath Grandhi 385a8e04698SSainath Grandhi drop: 386a8e04698SSainath Grandhi /* Count errors/drops only here, thus don't care about args. */ 3876fe3faf8SSainath Grandhi if (tap->count_rx_dropped) 3886fe3faf8SSainath Grandhi tap->count_rx_dropped(tap); 389a8e04698SSainath Grandhi kfree_skb(skb); 390a8e04698SSainath Grandhi return RX_HANDLER_CONSUMED; 391a8e04698SSainath Grandhi } 392a8e04698SSainath Grandhi 393*d9f1f61cSSainath Grandhi static struct major_info *tap_get_major(int major) 394*d9f1f61cSSainath Grandhi { 395*d9f1f61cSSainath Grandhi struct major_info *tap_major; 396*d9f1f61cSSainath Grandhi 397*d9f1f61cSSainath Grandhi list_for_each_entry_rcu(tap_major, &major_list, next) { 398*d9f1f61cSSainath Grandhi if (tap_major->major == major) 399*d9f1f61cSSainath Grandhi return tap_major; 400*d9f1f61cSSainath Grandhi } 401*d9f1f61cSSainath Grandhi 402*d9f1f61cSSainath Grandhi return NULL; 403*d9f1f61cSSainath Grandhi } 404*d9f1f61cSSainath Grandhi 405*d9f1f61cSSainath Grandhi int tap_get_minor(dev_t major, struct tap_dev *tap) 406a8e04698SSainath Grandhi { 407a8e04698SSainath Grandhi int retval = -ENOMEM; 408*d9f1f61cSSainath Grandhi struct major_info *tap_major; 409a8e04698SSainath Grandhi 410*d9f1f61cSSainath Grandhi rcu_read_lock(); 411*d9f1f61cSSainath Grandhi tap_major = tap_get_major(MAJOR(major)); 412*d9f1f61cSSainath Grandhi if (!tap_major) { 413*d9f1f61cSSainath Grandhi retval = -EINVAL; 414*d9f1f61cSSainath Grandhi goto unlock; 415*d9f1f61cSSainath Grandhi } 416*d9f1f61cSSainath Grandhi 417*d9f1f61cSSainath Grandhi mutex_lock(&tap_major->minor_lock); 418*d9f1f61cSSainath Grandhi retval = idr_alloc(&tap_major->minor_idr, tap, 1, TAP_NUM_DEVS, GFP_KERNEL); 419a8e04698SSainath Grandhi if (retval >= 0) { 4206fe3faf8SSainath Grandhi tap->minor = retval; 421a8e04698SSainath Grandhi } else if (retval == -ENOSPC) { 4226fe3faf8SSainath Grandhi netdev_err(tap->dev, "Too many tap devices\n"); 423a8e04698SSainath Grandhi retval = -EINVAL; 424a8e04698SSainath Grandhi } 425*d9f1f61cSSainath Grandhi mutex_unlock(&tap_major->minor_lock); 426*d9f1f61cSSainath Grandhi 427*d9f1f61cSSainath Grandhi unlock: 428*d9f1f61cSSainath Grandhi rcu_read_unlock(); 429a8e04698SSainath Grandhi return retval < 0 ? retval : 0; 430a8e04698SSainath Grandhi } 431a8e04698SSainath Grandhi 432*d9f1f61cSSainath Grandhi void tap_free_minor(dev_t major, struct tap_dev *tap) 433a8e04698SSainath Grandhi { 434*d9f1f61cSSainath Grandhi struct major_info *tap_major; 435*d9f1f61cSSainath Grandhi 436*d9f1f61cSSainath Grandhi rcu_read_lock(); 437*d9f1f61cSSainath Grandhi tap_major = tap_get_major(MAJOR(major)); 438*d9f1f61cSSainath Grandhi if (!tap_major) { 439*d9f1f61cSSainath Grandhi goto unlock; 440a8e04698SSainath Grandhi } 441a8e04698SSainath Grandhi 442*d9f1f61cSSainath Grandhi mutex_lock(&tap_major->minor_lock); 443*d9f1f61cSSainath Grandhi if (tap->minor) { 444*d9f1f61cSSainath Grandhi idr_remove(&tap_major->minor_idr, tap->minor); 445*d9f1f61cSSainath Grandhi tap->minor = 0; 446*d9f1f61cSSainath Grandhi } 447*d9f1f61cSSainath Grandhi mutex_unlock(&tap_major->minor_lock); 448*d9f1f61cSSainath Grandhi 449*d9f1f61cSSainath Grandhi unlock: 450*d9f1f61cSSainath Grandhi rcu_read_unlock(); 451*d9f1f61cSSainath Grandhi } 452*d9f1f61cSSainath Grandhi 453*d9f1f61cSSainath Grandhi static struct tap_dev *dev_get_by_tap_file(int major, int minor) 454a8e04698SSainath Grandhi { 455a8e04698SSainath Grandhi struct net_device *dev = NULL; 4566fe3faf8SSainath Grandhi struct tap_dev *tap; 457*d9f1f61cSSainath Grandhi struct major_info *tap_major; 458a8e04698SSainath Grandhi 459*d9f1f61cSSainath Grandhi rcu_read_lock(); 460*d9f1f61cSSainath Grandhi tap_major = tap_get_major(major); 461*d9f1f61cSSainath Grandhi if (!tap_major) { 462*d9f1f61cSSainath Grandhi tap = NULL; 463*d9f1f61cSSainath Grandhi goto unlock; 464*d9f1f61cSSainath Grandhi } 465*d9f1f61cSSainath Grandhi 466*d9f1f61cSSainath Grandhi mutex_lock(&tap_major->minor_lock); 467*d9f1f61cSSainath Grandhi tap = idr_find(&tap_major->minor_idr, minor); 4686fe3faf8SSainath Grandhi if (tap) { 4696fe3faf8SSainath Grandhi dev = tap->dev; 470a8e04698SSainath Grandhi dev_hold(dev); 471a8e04698SSainath Grandhi } 472*d9f1f61cSSainath Grandhi mutex_unlock(&tap_major->minor_lock); 473*d9f1f61cSSainath Grandhi 474*d9f1f61cSSainath Grandhi unlock: 475*d9f1f61cSSainath Grandhi rcu_read_unlock(); 4766fe3faf8SSainath Grandhi return tap; 477a8e04698SSainath Grandhi } 478a8e04698SSainath Grandhi 479635b8c8eSSainath Grandhi static void tap_sock_write_space(struct sock *sk) 480a8e04698SSainath Grandhi { 481a8e04698SSainath Grandhi wait_queue_head_t *wqueue; 482a8e04698SSainath Grandhi 483a8e04698SSainath Grandhi if (!sock_writeable(sk) || 484a8e04698SSainath Grandhi !test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)) 485a8e04698SSainath Grandhi return; 486a8e04698SSainath Grandhi 487a8e04698SSainath Grandhi wqueue = sk_sleep(sk); 488a8e04698SSainath Grandhi if (wqueue && waitqueue_active(wqueue)) 489a8e04698SSainath Grandhi wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND); 490a8e04698SSainath Grandhi } 491a8e04698SSainath Grandhi 492635b8c8eSSainath Grandhi static void tap_sock_destruct(struct sock *sk) 493a8e04698SSainath Grandhi { 494635b8c8eSSainath Grandhi struct tap_queue *q = container_of(sk, struct tap_queue, sk); 495a8e04698SSainath Grandhi 496a8e04698SSainath Grandhi skb_array_cleanup(&q->skb_array); 497a8e04698SSainath Grandhi } 498a8e04698SSainath Grandhi 499635b8c8eSSainath Grandhi static int tap_open(struct inode *inode, struct file *file) 500a8e04698SSainath Grandhi { 501a8e04698SSainath Grandhi struct net *net = current->nsproxy->net_ns; 5026fe3faf8SSainath Grandhi struct tap_dev *tap; 503635b8c8eSSainath Grandhi struct tap_queue *q; 504a8e04698SSainath Grandhi int err = -ENODEV; 505a8e04698SSainath Grandhi 506a8e04698SSainath Grandhi rtnl_lock(); 507*d9f1f61cSSainath Grandhi tap = dev_get_by_tap_file(imajor(inode), iminor(inode)); 5086fe3faf8SSainath Grandhi if (!tap) 509a8e04698SSainath Grandhi goto err; 510a8e04698SSainath Grandhi 511a8e04698SSainath Grandhi err = -ENOMEM; 512635b8c8eSSainath Grandhi q = (struct tap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, 513635b8c8eSSainath Grandhi &tap_proto, 0); 514a8e04698SSainath Grandhi if (!q) 515a8e04698SSainath Grandhi goto err; 516a8e04698SSainath Grandhi 517a8e04698SSainath Grandhi RCU_INIT_POINTER(q->sock.wq, &q->wq); 518a8e04698SSainath Grandhi init_waitqueue_head(&q->wq.wait); 519a8e04698SSainath Grandhi q->sock.type = SOCK_RAW; 520a8e04698SSainath Grandhi q->sock.state = SS_CONNECTED; 521a8e04698SSainath Grandhi q->sock.file = file; 522635b8c8eSSainath Grandhi q->sock.ops = &tap_socket_ops; 523a8e04698SSainath Grandhi sock_init_data(&q->sock, &q->sk); 524635b8c8eSSainath Grandhi q->sk.sk_write_space = tap_sock_write_space; 525635b8c8eSSainath Grandhi q->sk.sk_destruct = tap_sock_destruct; 526a8e04698SSainath Grandhi q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; 527a8e04698SSainath Grandhi q->vnet_hdr_sz = sizeof(struct virtio_net_hdr); 528a8e04698SSainath Grandhi 529a8e04698SSainath Grandhi /* 530635b8c8eSSainath Grandhi * so far only KVM virtio_net uses tap, enable zero copy between 531a8e04698SSainath Grandhi * guest kernel and host kernel when lower device supports zerocopy 532a8e04698SSainath Grandhi * 533a8e04698SSainath Grandhi * The macvlan supports zerocopy iff the lower device supports zero 534a8e04698SSainath Grandhi * copy so we don't have to look at the lower device directly. 535a8e04698SSainath Grandhi */ 5366fe3faf8SSainath Grandhi if ((tap->dev->features & NETIF_F_HIGHDMA) && (tap->dev->features & NETIF_F_SG)) 537a8e04698SSainath Grandhi sock_set_flag(&q->sk, SOCK_ZEROCOPY); 538a8e04698SSainath Grandhi 539a8e04698SSainath Grandhi err = -ENOMEM; 5406fe3faf8SSainath Grandhi if (skb_array_init(&q->skb_array, tap->dev->tx_queue_len, GFP_KERNEL)) 541a8e04698SSainath Grandhi goto err_array; 542a8e04698SSainath Grandhi 5436fe3faf8SSainath Grandhi err = tap_set_queue(tap, file, q); 544a8e04698SSainath Grandhi if (err) 545a8e04698SSainath Grandhi goto err_queue; 546a8e04698SSainath Grandhi 5476fe3faf8SSainath Grandhi dev_put(tap->dev); 548a8e04698SSainath Grandhi 549a8e04698SSainath Grandhi rtnl_unlock(); 550a8e04698SSainath Grandhi return err; 551a8e04698SSainath Grandhi 552a8e04698SSainath Grandhi err_queue: 553a8e04698SSainath Grandhi skb_array_cleanup(&q->skb_array); 554a8e04698SSainath Grandhi err_array: 555a8e04698SSainath Grandhi sock_put(&q->sk); 556a8e04698SSainath Grandhi err: 5576fe3faf8SSainath Grandhi if (tap) 5586fe3faf8SSainath Grandhi dev_put(tap->dev); 559a8e04698SSainath Grandhi 560a8e04698SSainath Grandhi rtnl_unlock(); 561a8e04698SSainath Grandhi return err; 562a8e04698SSainath Grandhi } 563a8e04698SSainath Grandhi 564635b8c8eSSainath Grandhi static int tap_release(struct inode *inode, struct file *file) 565a8e04698SSainath Grandhi { 566635b8c8eSSainath Grandhi struct tap_queue *q = file->private_data; 567635b8c8eSSainath Grandhi tap_put_queue(q); 568a8e04698SSainath Grandhi return 0; 569a8e04698SSainath Grandhi } 570a8e04698SSainath Grandhi 571635b8c8eSSainath Grandhi static unsigned int tap_poll(struct file *file, poll_table *wait) 572a8e04698SSainath Grandhi { 573635b8c8eSSainath Grandhi struct tap_queue *q = file->private_data; 574a8e04698SSainath Grandhi unsigned int mask = POLLERR; 575a8e04698SSainath Grandhi 576a8e04698SSainath Grandhi if (!q) 577a8e04698SSainath Grandhi goto out; 578a8e04698SSainath Grandhi 579a8e04698SSainath Grandhi mask = 0; 580a8e04698SSainath Grandhi poll_wait(file, &q->wq.wait, wait); 581a8e04698SSainath Grandhi 582a8e04698SSainath Grandhi if (!skb_array_empty(&q->skb_array)) 583a8e04698SSainath Grandhi mask |= POLLIN | POLLRDNORM; 584a8e04698SSainath Grandhi 585a8e04698SSainath Grandhi if (sock_writeable(&q->sk) || 586a8e04698SSainath Grandhi (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &q->sock.flags) && 587a8e04698SSainath Grandhi sock_writeable(&q->sk))) 588a8e04698SSainath Grandhi mask |= POLLOUT | POLLWRNORM; 589a8e04698SSainath Grandhi 590a8e04698SSainath Grandhi out: 591a8e04698SSainath Grandhi return mask; 592a8e04698SSainath Grandhi } 593a8e04698SSainath Grandhi 594635b8c8eSSainath Grandhi static inline struct sk_buff *tap_alloc_skb(struct sock *sk, size_t prepad, 595a8e04698SSainath Grandhi size_t len, size_t linear, 596a8e04698SSainath Grandhi int noblock, int *err) 597a8e04698SSainath Grandhi { 598a8e04698SSainath Grandhi struct sk_buff *skb; 599a8e04698SSainath Grandhi 600a8e04698SSainath Grandhi /* Under a page? Don't bother with paged skb. */ 601a8e04698SSainath Grandhi if (prepad + len < PAGE_SIZE || !linear) 602a8e04698SSainath Grandhi linear = len; 603a8e04698SSainath Grandhi 604a8e04698SSainath Grandhi skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, 605a8e04698SSainath Grandhi err, 0); 606a8e04698SSainath Grandhi if (!skb) 607a8e04698SSainath Grandhi return NULL; 608a8e04698SSainath Grandhi 609a8e04698SSainath Grandhi skb_reserve(skb, prepad); 610a8e04698SSainath Grandhi skb_put(skb, linear); 611a8e04698SSainath Grandhi skb->data_len = len - linear; 612a8e04698SSainath Grandhi skb->len += len - linear; 613a8e04698SSainath Grandhi 614a8e04698SSainath Grandhi return skb; 615a8e04698SSainath Grandhi } 616a8e04698SSainath Grandhi 617a8e04698SSainath Grandhi /* Neighbour code has some assumptions on HH_DATA_MOD alignment */ 618635b8c8eSSainath Grandhi #define TAP_RESERVE HH_DATA_OFF(ETH_HLEN) 619a8e04698SSainath Grandhi 620a8e04698SSainath Grandhi /* Get packet from user space buffer */ 621635b8c8eSSainath Grandhi static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m, 622a8e04698SSainath Grandhi struct iov_iter *from, int noblock) 623a8e04698SSainath Grandhi { 624635b8c8eSSainath Grandhi int good_linear = SKB_MAX_HEAD(TAP_RESERVE); 625a8e04698SSainath Grandhi struct sk_buff *skb; 6266fe3faf8SSainath Grandhi struct tap_dev *tap; 627a8e04698SSainath Grandhi unsigned long total_len = iov_iter_count(from); 628a8e04698SSainath Grandhi unsigned long len = total_len; 629a8e04698SSainath Grandhi int err; 630a8e04698SSainath Grandhi struct virtio_net_hdr vnet_hdr = { 0 }; 631a8e04698SSainath Grandhi int vnet_hdr_len = 0; 632a8e04698SSainath Grandhi int copylen = 0; 633a8e04698SSainath Grandhi int depth; 634a8e04698SSainath Grandhi bool zerocopy = false; 635a8e04698SSainath Grandhi size_t linear; 636a8e04698SSainath Grandhi 637a8e04698SSainath Grandhi if (q->flags & IFF_VNET_HDR) { 638a8e04698SSainath Grandhi vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz); 639a8e04698SSainath Grandhi 640a8e04698SSainath Grandhi err = -EINVAL; 641a8e04698SSainath Grandhi if (len < vnet_hdr_len) 642a8e04698SSainath Grandhi goto err; 643a8e04698SSainath Grandhi len -= vnet_hdr_len; 644a8e04698SSainath Grandhi 645a8e04698SSainath Grandhi err = -EFAULT; 646a8e04698SSainath Grandhi if (!copy_from_iter_full(&vnet_hdr, sizeof(vnet_hdr), from)) 647a8e04698SSainath Grandhi goto err; 648a8e04698SSainath Grandhi iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr)); 649a8e04698SSainath Grandhi if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && 650635b8c8eSSainath Grandhi tap16_to_cpu(q, vnet_hdr.csum_start) + 651635b8c8eSSainath Grandhi tap16_to_cpu(q, vnet_hdr.csum_offset) + 2 > 652635b8c8eSSainath Grandhi tap16_to_cpu(q, vnet_hdr.hdr_len)) 653635b8c8eSSainath Grandhi vnet_hdr.hdr_len = cpu_to_tap16(q, 654635b8c8eSSainath Grandhi tap16_to_cpu(q, vnet_hdr.csum_start) + 655635b8c8eSSainath Grandhi tap16_to_cpu(q, vnet_hdr.csum_offset) + 2); 656a8e04698SSainath Grandhi err = -EINVAL; 657635b8c8eSSainath Grandhi if (tap16_to_cpu(q, vnet_hdr.hdr_len) > len) 658a8e04698SSainath Grandhi goto err; 659a8e04698SSainath Grandhi } 660a8e04698SSainath Grandhi 661a8e04698SSainath Grandhi err = -EINVAL; 662a8e04698SSainath Grandhi if (unlikely(len < ETH_HLEN)) 663a8e04698SSainath Grandhi goto err; 664a8e04698SSainath Grandhi 665a8e04698SSainath Grandhi if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { 666a8e04698SSainath Grandhi struct iov_iter i; 667a8e04698SSainath Grandhi 668a8e04698SSainath Grandhi copylen = vnet_hdr.hdr_len ? 669635b8c8eSSainath Grandhi tap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN; 670a8e04698SSainath Grandhi if (copylen > good_linear) 671a8e04698SSainath Grandhi copylen = good_linear; 672a8e04698SSainath Grandhi else if (copylen < ETH_HLEN) 673a8e04698SSainath Grandhi copylen = ETH_HLEN; 674a8e04698SSainath Grandhi linear = copylen; 675a8e04698SSainath Grandhi i = *from; 676a8e04698SSainath Grandhi iov_iter_advance(&i, copylen); 677a8e04698SSainath Grandhi if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS) 678a8e04698SSainath Grandhi zerocopy = true; 679a8e04698SSainath Grandhi } 680a8e04698SSainath Grandhi 681a8e04698SSainath Grandhi if (!zerocopy) { 682a8e04698SSainath Grandhi copylen = len; 683635b8c8eSSainath Grandhi linear = tap16_to_cpu(q, vnet_hdr.hdr_len); 684a8e04698SSainath Grandhi if (linear > good_linear) 685a8e04698SSainath Grandhi linear = good_linear; 686a8e04698SSainath Grandhi else if (linear < ETH_HLEN) 687a8e04698SSainath Grandhi linear = ETH_HLEN; 688a8e04698SSainath Grandhi } 689a8e04698SSainath Grandhi 690635b8c8eSSainath Grandhi skb = tap_alloc_skb(&q->sk, TAP_RESERVE, copylen, 691a8e04698SSainath Grandhi linear, noblock, &err); 692a8e04698SSainath Grandhi if (!skb) 693a8e04698SSainath Grandhi goto err; 694a8e04698SSainath Grandhi 695a8e04698SSainath Grandhi if (zerocopy) 696a8e04698SSainath Grandhi err = zerocopy_sg_from_iter(skb, from); 697a8e04698SSainath Grandhi else 698a8e04698SSainath Grandhi err = skb_copy_datagram_from_iter(skb, 0, from, len); 699a8e04698SSainath Grandhi 700a8e04698SSainath Grandhi if (err) 701a8e04698SSainath Grandhi goto err_kfree; 702a8e04698SSainath Grandhi 703a8e04698SSainath Grandhi skb_set_network_header(skb, ETH_HLEN); 704a8e04698SSainath Grandhi skb_reset_mac_header(skb); 705a8e04698SSainath Grandhi skb->protocol = eth_hdr(skb)->h_proto; 706a8e04698SSainath Grandhi 707a8e04698SSainath Grandhi if (vnet_hdr_len) { 708a8e04698SSainath Grandhi err = virtio_net_hdr_to_skb(skb, &vnet_hdr, 709635b8c8eSSainath Grandhi tap_is_little_endian(q)); 710a8e04698SSainath Grandhi if (err) 711a8e04698SSainath Grandhi goto err_kfree; 712a8e04698SSainath Grandhi } 713a8e04698SSainath Grandhi 714a8e04698SSainath Grandhi skb_probe_transport_header(skb, ETH_HLEN); 715a8e04698SSainath Grandhi 716a8e04698SSainath Grandhi /* Move network header to the right position for VLAN tagged packets */ 717a8e04698SSainath Grandhi if ((skb->protocol == htons(ETH_P_8021Q) || 718a8e04698SSainath Grandhi skb->protocol == htons(ETH_P_8021AD)) && 719a8e04698SSainath Grandhi __vlan_get_protocol(skb, skb->protocol, &depth) != 0) 720a8e04698SSainath Grandhi skb_set_network_header(skb, depth); 721a8e04698SSainath Grandhi 722a8e04698SSainath Grandhi rcu_read_lock(); 7236fe3faf8SSainath Grandhi tap = rcu_dereference(q->tap); 724a8e04698SSainath Grandhi /* copy skb_ubuf_info for callback when skb has no error */ 725a8e04698SSainath Grandhi if (zerocopy) { 726a8e04698SSainath Grandhi skb_shinfo(skb)->destructor_arg = m->msg_control; 727a8e04698SSainath Grandhi skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; 728a8e04698SSainath Grandhi skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; 729a8e04698SSainath Grandhi } else if (m && m->msg_control) { 730a8e04698SSainath Grandhi struct ubuf_info *uarg = m->msg_control; 731a8e04698SSainath Grandhi uarg->callback(uarg, false); 732a8e04698SSainath Grandhi } 733a8e04698SSainath Grandhi 7346fe3faf8SSainath Grandhi if (tap) { 7356fe3faf8SSainath Grandhi skb->dev = tap->dev; 736a8e04698SSainath Grandhi dev_queue_xmit(skb); 737a8e04698SSainath Grandhi } else { 738a8e04698SSainath Grandhi kfree_skb(skb); 739a8e04698SSainath Grandhi } 740a8e04698SSainath Grandhi rcu_read_unlock(); 741a8e04698SSainath Grandhi 742a8e04698SSainath Grandhi return total_len; 743a8e04698SSainath Grandhi 744a8e04698SSainath Grandhi err_kfree: 745a8e04698SSainath Grandhi kfree_skb(skb); 746a8e04698SSainath Grandhi 747a8e04698SSainath Grandhi err: 748a8e04698SSainath Grandhi rcu_read_lock(); 7496fe3faf8SSainath Grandhi tap = rcu_dereference(q->tap); 7506fe3faf8SSainath Grandhi if (tap && tap->count_tx_dropped) 7516fe3faf8SSainath Grandhi tap->count_tx_dropped(tap); 752a8e04698SSainath Grandhi rcu_read_unlock(); 753a8e04698SSainath Grandhi 754a8e04698SSainath Grandhi return err; 755a8e04698SSainath Grandhi } 756a8e04698SSainath Grandhi 757635b8c8eSSainath Grandhi static ssize_t tap_write_iter(struct kiocb *iocb, struct iov_iter *from) 758a8e04698SSainath Grandhi { 759a8e04698SSainath Grandhi struct file *file = iocb->ki_filp; 760635b8c8eSSainath Grandhi struct tap_queue *q = file->private_data; 761a8e04698SSainath Grandhi 762635b8c8eSSainath Grandhi return tap_get_user(q, NULL, from, file->f_flags & O_NONBLOCK); 763a8e04698SSainath Grandhi } 764a8e04698SSainath Grandhi 765a8e04698SSainath Grandhi /* Put packet to the user space buffer */ 766635b8c8eSSainath Grandhi static ssize_t tap_put_user(struct tap_queue *q, 767a8e04698SSainath Grandhi const struct sk_buff *skb, 768a8e04698SSainath Grandhi struct iov_iter *iter) 769a8e04698SSainath Grandhi { 770a8e04698SSainath Grandhi int ret; 771a8e04698SSainath Grandhi int vnet_hdr_len = 0; 772a8e04698SSainath Grandhi int vlan_offset = 0; 773a8e04698SSainath Grandhi int total; 774a8e04698SSainath Grandhi 775a8e04698SSainath Grandhi if (q->flags & IFF_VNET_HDR) { 776a8e04698SSainath Grandhi struct virtio_net_hdr vnet_hdr; 777a8e04698SSainath Grandhi vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz); 778a8e04698SSainath Grandhi if (iov_iter_count(iter) < vnet_hdr_len) 779a8e04698SSainath Grandhi return -EINVAL; 780a8e04698SSainath Grandhi 781a8e04698SSainath Grandhi if (virtio_net_hdr_from_skb(skb, &vnet_hdr, 782635b8c8eSSainath Grandhi tap_is_little_endian(q), true)) 783a8e04698SSainath Grandhi BUG(); 784a8e04698SSainath Grandhi 785a8e04698SSainath Grandhi if (copy_to_iter(&vnet_hdr, sizeof(vnet_hdr), iter) != 786a8e04698SSainath Grandhi sizeof(vnet_hdr)) 787a8e04698SSainath Grandhi return -EFAULT; 788a8e04698SSainath Grandhi 789a8e04698SSainath Grandhi iov_iter_advance(iter, vnet_hdr_len - sizeof(vnet_hdr)); 790a8e04698SSainath Grandhi } 791a8e04698SSainath Grandhi total = vnet_hdr_len; 792a8e04698SSainath Grandhi total += skb->len; 793a8e04698SSainath Grandhi 794a8e04698SSainath Grandhi if (skb_vlan_tag_present(skb)) { 795a8e04698SSainath Grandhi struct { 796a8e04698SSainath Grandhi __be16 h_vlan_proto; 797a8e04698SSainath Grandhi __be16 h_vlan_TCI; 798a8e04698SSainath Grandhi } veth; 799a8e04698SSainath Grandhi veth.h_vlan_proto = skb->vlan_proto; 800a8e04698SSainath Grandhi veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb)); 801a8e04698SSainath Grandhi 802a8e04698SSainath Grandhi vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); 803a8e04698SSainath Grandhi total += VLAN_HLEN; 804a8e04698SSainath Grandhi 805a8e04698SSainath Grandhi ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset); 806a8e04698SSainath Grandhi if (ret || !iov_iter_count(iter)) 807a8e04698SSainath Grandhi goto done; 808a8e04698SSainath Grandhi 809a8e04698SSainath Grandhi ret = copy_to_iter(&veth, sizeof(veth), iter); 810a8e04698SSainath Grandhi if (ret != sizeof(veth) || !iov_iter_count(iter)) 811a8e04698SSainath Grandhi goto done; 812a8e04698SSainath Grandhi } 813a8e04698SSainath Grandhi 814a8e04698SSainath Grandhi ret = skb_copy_datagram_iter(skb, vlan_offset, iter, 815a8e04698SSainath Grandhi skb->len - vlan_offset); 816a8e04698SSainath Grandhi 817a8e04698SSainath Grandhi done: 818a8e04698SSainath Grandhi return ret ? ret : total; 819a8e04698SSainath Grandhi } 820a8e04698SSainath Grandhi 821635b8c8eSSainath Grandhi static ssize_t tap_do_read(struct tap_queue *q, 822a8e04698SSainath Grandhi struct iov_iter *to, 823a8e04698SSainath Grandhi int noblock) 824a8e04698SSainath Grandhi { 825a8e04698SSainath Grandhi DEFINE_WAIT(wait); 826a8e04698SSainath Grandhi struct sk_buff *skb; 827a8e04698SSainath Grandhi ssize_t ret = 0; 828a8e04698SSainath Grandhi 829a8e04698SSainath Grandhi if (!iov_iter_count(to)) 830a8e04698SSainath Grandhi return 0; 831a8e04698SSainath Grandhi 832a8e04698SSainath Grandhi while (1) { 833a8e04698SSainath Grandhi if (!noblock) 834a8e04698SSainath Grandhi prepare_to_wait(sk_sleep(&q->sk), &wait, 835a8e04698SSainath Grandhi TASK_INTERRUPTIBLE); 836a8e04698SSainath Grandhi 837a8e04698SSainath Grandhi /* Read frames from the queue */ 838a8e04698SSainath Grandhi skb = skb_array_consume(&q->skb_array); 839a8e04698SSainath Grandhi if (skb) 840a8e04698SSainath Grandhi break; 841a8e04698SSainath Grandhi if (noblock) { 842a8e04698SSainath Grandhi ret = -EAGAIN; 843a8e04698SSainath Grandhi break; 844a8e04698SSainath Grandhi } 845a8e04698SSainath Grandhi if (signal_pending(current)) { 846a8e04698SSainath Grandhi ret = -ERESTARTSYS; 847a8e04698SSainath Grandhi break; 848a8e04698SSainath Grandhi } 849a8e04698SSainath Grandhi /* Nothing to read, let's sleep */ 850a8e04698SSainath Grandhi schedule(); 851a8e04698SSainath Grandhi } 852a8e04698SSainath Grandhi if (!noblock) 853a8e04698SSainath Grandhi finish_wait(sk_sleep(&q->sk), &wait); 854a8e04698SSainath Grandhi 855a8e04698SSainath Grandhi if (skb) { 856635b8c8eSSainath Grandhi ret = tap_put_user(q, skb, to); 857a8e04698SSainath Grandhi if (unlikely(ret < 0)) 858a8e04698SSainath Grandhi kfree_skb(skb); 859a8e04698SSainath Grandhi else 860a8e04698SSainath Grandhi consume_skb(skb); 861a8e04698SSainath Grandhi } 862a8e04698SSainath Grandhi return ret; 863a8e04698SSainath Grandhi } 864a8e04698SSainath Grandhi 865635b8c8eSSainath Grandhi static ssize_t tap_read_iter(struct kiocb *iocb, struct iov_iter *to) 866a8e04698SSainath Grandhi { 867a8e04698SSainath Grandhi struct file *file = iocb->ki_filp; 868635b8c8eSSainath Grandhi struct tap_queue *q = file->private_data; 869a8e04698SSainath Grandhi ssize_t len = iov_iter_count(to), ret; 870a8e04698SSainath Grandhi 871635b8c8eSSainath Grandhi ret = tap_do_read(q, to, file->f_flags & O_NONBLOCK); 872a8e04698SSainath Grandhi ret = min_t(ssize_t, ret, len); 873a8e04698SSainath Grandhi if (ret > 0) 874a8e04698SSainath Grandhi iocb->ki_pos = ret; 875a8e04698SSainath Grandhi return ret; 876a8e04698SSainath Grandhi } 877a8e04698SSainath Grandhi 8786fe3faf8SSainath Grandhi static struct tap_dev *tap_get_tap_dev(struct tap_queue *q) 879a8e04698SSainath Grandhi { 8806fe3faf8SSainath Grandhi struct tap_dev *tap; 881a8e04698SSainath Grandhi 882a8e04698SSainath Grandhi ASSERT_RTNL(); 8836fe3faf8SSainath Grandhi tap = rtnl_dereference(q->tap); 8846fe3faf8SSainath Grandhi if (tap) 8856fe3faf8SSainath Grandhi dev_hold(tap->dev); 886a8e04698SSainath Grandhi 8876fe3faf8SSainath Grandhi return tap; 888a8e04698SSainath Grandhi } 889a8e04698SSainath Grandhi 8906fe3faf8SSainath Grandhi static void tap_put_tap_dev(struct tap_dev *tap) 891a8e04698SSainath Grandhi { 8926fe3faf8SSainath Grandhi dev_put(tap->dev); 893a8e04698SSainath Grandhi } 894a8e04698SSainath Grandhi 895635b8c8eSSainath Grandhi static int tap_ioctl_set_queue(struct file *file, unsigned int flags) 896a8e04698SSainath Grandhi { 897635b8c8eSSainath Grandhi struct tap_queue *q = file->private_data; 8986fe3faf8SSainath Grandhi struct tap_dev *tap; 899a8e04698SSainath Grandhi int ret; 900a8e04698SSainath Grandhi 9016fe3faf8SSainath Grandhi tap = tap_get_tap_dev(q); 9026fe3faf8SSainath Grandhi if (!tap) 903a8e04698SSainath Grandhi return -EINVAL; 904a8e04698SSainath Grandhi 905a8e04698SSainath Grandhi if (flags & IFF_ATTACH_QUEUE) 9066fe3faf8SSainath Grandhi ret = tap_enable_queue(tap, file, q); 907a8e04698SSainath Grandhi else if (flags & IFF_DETACH_QUEUE) 908635b8c8eSSainath Grandhi ret = tap_disable_queue(q); 909a8e04698SSainath Grandhi else 910a8e04698SSainath Grandhi ret = -EINVAL; 911a8e04698SSainath Grandhi 9126fe3faf8SSainath Grandhi tap_put_tap_dev(tap); 913a8e04698SSainath Grandhi return ret; 914a8e04698SSainath Grandhi } 915a8e04698SSainath Grandhi 916635b8c8eSSainath Grandhi static int set_offload(struct tap_queue *q, unsigned long arg) 917a8e04698SSainath Grandhi { 9186fe3faf8SSainath Grandhi struct tap_dev *tap; 919a8e04698SSainath Grandhi netdev_features_t features; 920a8e04698SSainath Grandhi netdev_features_t feature_mask = 0; 921a8e04698SSainath Grandhi 9226fe3faf8SSainath Grandhi tap = rtnl_dereference(q->tap); 9236fe3faf8SSainath Grandhi if (!tap) 924a8e04698SSainath Grandhi return -ENOLINK; 925a8e04698SSainath Grandhi 9266fe3faf8SSainath Grandhi features = tap->dev->features; 927a8e04698SSainath Grandhi 928a8e04698SSainath Grandhi if (arg & TUN_F_CSUM) { 929a8e04698SSainath Grandhi feature_mask = NETIF_F_HW_CSUM; 930a8e04698SSainath Grandhi 931a8e04698SSainath Grandhi if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) { 932a8e04698SSainath Grandhi if (arg & TUN_F_TSO_ECN) 933a8e04698SSainath Grandhi feature_mask |= NETIF_F_TSO_ECN; 934a8e04698SSainath Grandhi if (arg & TUN_F_TSO4) 935a8e04698SSainath Grandhi feature_mask |= NETIF_F_TSO; 936a8e04698SSainath Grandhi if (arg & TUN_F_TSO6) 937a8e04698SSainath Grandhi feature_mask |= NETIF_F_TSO6; 938a8e04698SSainath Grandhi } 939a8e04698SSainath Grandhi 940a8e04698SSainath Grandhi if (arg & TUN_F_UFO) 941a8e04698SSainath Grandhi feature_mask |= NETIF_F_UFO; 942a8e04698SSainath Grandhi } 943a8e04698SSainath Grandhi 944a8e04698SSainath Grandhi /* tun/tap driver inverts the usage for TSO offloads, where 945a8e04698SSainath Grandhi * setting the TSO bit means that the userspace wants to 946a8e04698SSainath Grandhi * accept TSO frames and turning it off means that user space 947a8e04698SSainath Grandhi * does not support TSO. 948635b8c8eSSainath Grandhi * For tap, we have to invert it to mean the same thing. 949a8e04698SSainath Grandhi * When user space turns off TSO, we turn off GSO/LRO so that 950a8e04698SSainath Grandhi * user-space will not receive TSO frames. 951a8e04698SSainath Grandhi */ 952a8e04698SSainath Grandhi if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_UFO)) 953a8e04698SSainath Grandhi features |= RX_OFFLOADS; 954a8e04698SSainath Grandhi else 955a8e04698SSainath Grandhi features &= ~RX_OFFLOADS; 956a8e04698SSainath Grandhi 957a8e04698SSainath Grandhi /* tap_features are the same as features on tun/tap and 958a8e04698SSainath Grandhi * reflect user expectations. 959a8e04698SSainath Grandhi */ 9606fe3faf8SSainath Grandhi tap->tap_features = feature_mask; 9616fe3faf8SSainath Grandhi if (tap->update_features) 9626fe3faf8SSainath Grandhi tap->update_features(tap, features); 963a8e04698SSainath Grandhi 964a8e04698SSainath Grandhi return 0; 965a8e04698SSainath Grandhi } 966a8e04698SSainath Grandhi 967a8e04698SSainath Grandhi /* 968a8e04698SSainath Grandhi * provide compatibility with generic tun/tap interface 969a8e04698SSainath Grandhi */ 970635b8c8eSSainath Grandhi static long tap_ioctl(struct file *file, unsigned int cmd, 971a8e04698SSainath Grandhi unsigned long arg) 972a8e04698SSainath Grandhi { 973635b8c8eSSainath Grandhi struct tap_queue *q = file->private_data; 9746fe3faf8SSainath Grandhi struct tap_dev *tap; 975a8e04698SSainath Grandhi void __user *argp = (void __user *)arg; 976a8e04698SSainath Grandhi struct ifreq __user *ifr = argp; 977a8e04698SSainath Grandhi unsigned int __user *up = argp; 978a8e04698SSainath Grandhi unsigned short u; 979a8e04698SSainath Grandhi int __user *sp = argp; 980a8e04698SSainath Grandhi struct sockaddr sa; 981a8e04698SSainath Grandhi int s; 982a8e04698SSainath Grandhi int ret; 983a8e04698SSainath Grandhi 984a8e04698SSainath Grandhi switch (cmd) { 985a8e04698SSainath Grandhi case TUNSETIFF: 986a8e04698SSainath Grandhi /* ignore the name, just look at flags */ 987a8e04698SSainath Grandhi if (get_user(u, &ifr->ifr_flags)) 988a8e04698SSainath Grandhi return -EFAULT; 989a8e04698SSainath Grandhi 990a8e04698SSainath Grandhi ret = 0; 991635b8c8eSSainath Grandhi if ((u & ~TAP_IFFEATURES) != (IFF_NO_PI | IFF_TAP)) 992a8e04698SSainath Grandhi ret = -EINVAL; 993a8e04698SSainath Grandhi else 994635b8c8eSSainath Grandhi q->flags = (q->flags & ~TAP_IFFEATURES) | u; 995a8e04698SSainath Grandhi 996a8e04698SSainath Grandhi return ret; 997a8e04698SSainath Grandhi 998a8e04698SSainath Grandhi case TUNGETIFF: 999a8e04698SSainath Grandhi rtnl_lock(); 10006fe3faf8SSainath Grandhi tap = tap_get_tap_dev(q); 10016fe3faf8SSainath Grandhi if (!tap) { 1002a8e04698SSainath Grandhi rtnl_unlock(); 1003a8e04698SSainath Grandhi return -ENOLINK; 1004a8e04698SSainath Grandhi } 1005a8e04698SSainath Grandhi 1006a8e04698SSainath Grandhi ret = 0; 1007a8e04698SSainath Grandhi u = q->flags; 10086fe3faf8SSainath Grandhi if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) || 1009a8e04698SSainath Grandhi put_user(u, &ifr->ifr_flags)) 1010a8e04698SSainath Grandhi ret = -EFAULT; 10116fe3faf8SSainath Grandhi tap_put_tap_dev(tap); 1012a8e04698SSainath Grandhi rtnl_unlock(); 1013a8e04698SSainath Grandhi return ret; 1014a8e04698SSainath Grandhi 1015a8e04698SSainath Grandhi case TUNSETQUEUE: 1016a8e04698SSainath Grandhi if (get_user(u, &ifr->ifr_flags)) 1017a8e04698SSainath Grandhi return -EFAULT; 1018a8e04698SSainath Grandhi rtnl_lock(); 1019635b8c8eSSainath Grandhi ret = tap_ioctl_set_queue(file, u); 1020a8e04698SSainath Grandhi rtnl_unlock(); 1021a8e04698SSainath Grandhi return ret; 1022a8e04698SSainath Grandhi 1023a8e04698SSainath Grandhi case TUNGETFEATURES: 1024635b8c8eSSainath Grandhi if (put_user(IFF_TAP | IFF_NO_PI | TAP_IFFEATURES, up)) 1025a8e04698SSainath Grandhi return -EFAULT; 1026a8e04698SSainath Grandhi return 0; 1027a8e04698SSainath Grandhi 1028a8e04698SSainath Grandhi case TUNSETSNDBUF: 1029a8e04698SSainath Grandhi if (get_user(s, sp)) 1030a8e04698SSainath Grandhi return -EFAULT; 1031a8e04698SSainath Grandhi 1032a8e04698SSainath Grandhi q->sk.sk_sndbuf = s; 1033a8e04698SSainath Grandhi return 0; 1034a8e04698SSainath Grandhi 1035a8e04698SSainath Grandhi case TUNGETVNETHDRSZ: 1036a8e04698SSainath Grandhi s = q->vnet_hdr_sz; 1037a8e04698SSainath Grandhi if (put_user(s, sp)) 1038a8e04698SSainath Grandhi return -EFAULT; 1039a8e04698SSainath Grandhi return 0; 1040a8e04698SSainath Grandhi 1041a8e04698SSainath Grandhi case TUNSETVNETHDRSZ: 1042a8e04698SSainath Grandhi if (get_user(s, sp)) 1043a8e04698SSainath Grandhi return -EFAULT; 1044a8e04698SSainath Grandhi if (s < (int)sizeof(struct virtio_net_hdr)) 1045a8e04698SSainath Grandhi return -EINVAL; 1046a8e04698SSainath Grandhi 1047a8e04698SSainath Grandhi q->vnet_hdr_sz = s; 1048a8e04698SSainath Grandhi return 0; 1049a8e04698SSainath Grandhi 1050a8e04698SSainath Grandhi case TUNGETVNETLE: 1051635b8c8eSSainath Grandhi s = !!(q->flags & TAP_VNET_LE); 1052a8e04698SSainath Grandhi if (put_user(s, sp)) 1053a8e04698SSainath Grandhi return -EFAULT; 1054a8e04698SSainath Grandhi return 0; 1055a8e04698SSainath Grandhi 1056a8e04698SSainath Grandhi case TUNSETVNETLE: 1057a8e04698SSainath Grandhi if (get_user(s, sp)) 1058a8e04698SSainath Grandhi return -EFAULT; 1059a8e04698SSainath Grandhi if (s) 1060635b8c8eSSainath Grandhi q->flags |= TAP_VNET_LE; 1061a8e04698SSainath Grandhi else 1062635b8c8eSSainath Grandhi q->flags &= ~TAP_VNET_LE; 1063a8e04698SSainath Grandhi return 0; 1064a8e04698SSainath Grandhi 1065a8e04698SSainath Grandhi case TUNGETVNETBE: 1066635b8c8eSSainath Grandhi return tap_get_vnet_be(q, sp); 1067a8e04698SSainath Grandhi 1068a8e04698SSainath Grandhi case TUNSETVNETBE: 1069635b8c8eSSainath Grandhi return tap_set_vnet_be(q, sp); 1070a8e04698SSainath Grandhi 1071a8e04698SSainath Grandhi case TUNSETOFFLOAD: 1072a8e04698SSainath Grandhi /* let the user check for future flags */ 1073a8e04698SSainath Grandhi if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | 1074a8e04698SSainath Grandhi TUN_F_TSO_ECN | TUN_F_UFO)) 1075a8e04698SSainath Grandhi return -EINVAL; 1076a8e04698SSainath Grandhi 1077a8e04698SSainath Grandhi rtnl_lock(); 1078a8e04698SSainath Grandhi ret = set_offload(q, arg); 1079a8e04698SSainath Grandhi rtnl_unlock(); 1080a8e04698SSainath Grandhi return ret; 1081a8e04698SSainath Grandhi 1082a8e04698SSainath Grandhi case SIOCGIFHWADDR: 1083a8e04698SSainath Grandhi rtnl_lock(); 10846fe3faf8SSainath Grandhi tap = tap_get_tap_dev(q); 10856fe3faf8SSainath Grandhi if (!tap) { 1086a8e04698SSainath Grandhi rtnl_unlock(); 1087a8e04698SSainath Grandhi return -ENOLINK; 1088a8e04698SSainath Grandhi } 1089a8e04698SSainath Grandhi ret = 0; 10906fe3faf8SSainath Grandhi u = tap->dev->type; 10916fe3faf8SSainath Grandhi if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) || 10926fe3faf8SSainath Grandhi copy_to_user(&ifr->ifr_hwaddr.sa_data, tap->dev->dev_addr, ETH_ALEN) || 1093a8e04698SSainath Grandhi put_user(u, &ifr->ifr_hwaddr.sa_family)) 1094a8e04698SSainath Grandhi ret = -EFAULT; 10956fe3faf8SSainath Grandhi tap_put_tap_dev(tap); 1096a8e04698SSainath Grandhi rtnl_unlock(); 1097a8e04698SSainath Grandhi return ret; 1098a8e04698SSainath Grandhi 1099a8e04698SSainath Grandhi case SIOCSIFHWADDR: 1100a8e04698SSainath Grandhi if (copy_from_user(&sa, &ifr->ifr_hwaddr, sizeof(sa))) 1101a8e04698SSainath Grandhi return -EFAULT; 1102a8e04698SSainath Grandhi rtnl_lock(); 11036fe3faf8SSainath Grandhi tap = tap_get_tap_dev(q); 11046fe3faf8SSainath Grandhi if (!tap) { 1105a8e04698SSainath Grandhi rtnl_unlock(); 1106a8e04698SSainath Grandhi return -ENOLINK; 1107a8e04698SSainath Grandhi } 11086fe3faf8SSainath Grandhi ret = dev_set_mac_address(tap->dev, &sa); 11096fe3faf8SSainath Grandhi tap_put_tap_dev(tap); 1110a8e04698SSainath Grandhi rtnl_unlock(); 1111a8e04698SSainath Grandhi return ret; 1112a8e04698SSainath Grandhi 1113a8e04698SSainath Grandhi default: 1114a8e04698SSainath Grandhi return -EINVAL; 1115a8e04698SSainath Grandhi } 1116a8e04698SSainath Grandhi } 1117a8e04698SSainath Grandhi 1118a8e04698SSainath Grandhi #ifdef CONFIG_COMPAT 1119635b8c8eSSainath Grandhi static long tap_compat_ioctl(struct file *file, unsigned int cmd, 1120a8e04698SSainath Grandhi unsigned long arg) 1121a8e04698SSainath Grandhi { 1122635b8c8eSSainath Grandhi return tap_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 1123a8e04698SSainath Grandhi } 1124a8e04698SSainath Grandhi #endif 1125a8e04698SSainath Grandhi 1126635b8c8eSSainath Grandhi const struct file_operations tap_fops = { 1127a8e04698SSainath Grandhi .owner = THIS_MODULE, 1128635b8c8eSSainath Grandhi .open = tap_open, 1129635b8c8eSSainath Grandhi .release = tap_release, 1130635b8c8eSSainath Grandhi .read_iter = tap_read_iter, 1131635b8c8eSSainath Grandhi .write_iter = tap_write_iter, 1132635b8c8eSSainath Grandhi .poll = tap_poll, 1133a8e04698SSainath Grandhi .llseek = no_llseek, 1134635b8c8eSSainath Grandhi .unlocked_ioctl = tap_ioctl, 1135a8e04698SSainath Grandhi #ifdef CONFIG_COMPAT 1136635b8c8eSSainath Grandhi .compat_ioctl = tap_compat_ioctl, 1137a8e04698SSainath Grandhi #endif 1138a8e04698SSainath Grandhi }; 1139a8e04698SSainath Grandhi 1140635b8c8eSSainath Grandhi static int tap_sendmsg(struct socket *sock, struct msghdr *m, 1141a8e04698SSainath Grandhi size_t total_len) 1142a8e04698SSainath Grandhi { 1143635b8c8eSSainath Grandhi struct tap_queue *q = container_of(sock, struct tap_queue, sock); 1144635b8c8eSSainath Grandhi return tap_get_user(q, m, &m->msg_iter, m->msg_flags & MSG_DONTWAIT); 1145a8e04698SSainath Grandhi } 1146a8e04698SSainath Grandhi 1147635b8c8eSSainath Grandhi static int tap_recvmsg(struct socket *sock, struct msghdr *m, 1148a8e04698SSainath Grandhi size_t total_len, int flags) 1149a8e04698SSainath Grandhi { 1150635b8c8eSSainath Grandhi struct tap_queue *q = container_of(sock, struct tap_queue, sock); 1151a8e04698SSainath Grandhi int ret; 1152a8e04698SSainath Grandhi if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) 1153a8e04698SSainath Grandhi return -EINVAL; 1154635b8c8eSSainath Grandhi ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT); 1155a8e04698SSainath Grandhi if (ret > total_len) { 1156a8e04698SSainath Grandhi m->msg_flags |= MSG_TRUNC; 1157a8e04698SSainath Grandhi ret = flags & MSG_TRUNC ? ret : total_len; 1158a8e04698SSainath Grandhi } 1159a8e04698SSainath Grandhi return ret; 1160a8e04698SSainath Grandhi } 1161a8e04698SSainath Grandhi 1162635b8c8eSSainath Grandhi static int tap_peek_len(struct socket *sock) 1163a8e04698SSainath Grandhi { 1164635b8c8eSSainath Grandhi struct tap_queue *q = container_of(sock, struct tap_queue, 1165a8e04698SSainath Grandhi sock); 1166a8e04698SSainath Grandhi return skb_array_peek_len(&q->skb_array); 1167a8e04698SSainath Grandhi } 1168a8e04698SSainath Grandhi 1169a8e04698SSainath Grandhi /* Ops structure to mimic raw sockets with tun */ 1170635b8c8eSSainath Grandhi static const struct proto_ops tap_socket_ops = { 1171635b8c8eSSainath Grandhi .sendmsg = tap_sendmsg, 1172635b8c8eSSainath Grandhi .recvmsg = tap_recvmsg, 1173635b8c8eSSainath Grandhi .peek_len = tap_peek_len, 1174a8e04698SSainath Grandhi }; 1175a8e04698SSainath Grandhi 1176a8e04698SSainath Grandhi /* Get an underlying socket object from tun file. Returns error unless file is 1177a8e04698SSainath Grandhi * attached to a device. The returned object works like a packet socket, it 1178a8e04698SSainath Grandhi * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for 1179a8e04698SSainath Grandhi * holding a reference to the file for as long as the socket is in use. */ 1180635b8c8eSSainath Grandhi struct socket *tap_get_socket(struct file *file) 1181a8e04698SSainath Grandhi { 1182635b8c8eSSainath Grandhi struct tap_queue *q; 1183635b8c8eSSainath Grandhi if (file->f_op != &tap_fops) 1184a8e04698SSainath Grandhi return ERR_PTR(-EINVAL); 1185a8e04698SSainath Grandhi q = file->private_data; 1186a8e04698SSainath Grandhi if (!q) 1187a8e04698SSainath Grandhi return ERR_PTR(-EBADFD); 1188a8e04698SSainath Grandhi return &q->sock; 1189a8e04698SSainath Grandhi } 1190635b8c8eSSainath Grandhi EXPORT_SYMBOL_GPL(tap_get_socket); 1191a8e04698SSainath Grandhi 11926fe3faf8SSainath Grandhi int tap_queue_resize(struct tap_dev *tap) 1193a8e04698SSainath Grandhi { 11946fe3faf8SSainath Grandhi struct net_device *dev = tap->dev; 1195635b8c8eSSainath Grandhi struct tap_queue *q; 1196a8e04698SSainath Grandhi struct skb_array **arrays; 11976fe3faf8SSainath Grandhi int n = tap->numqueues; 1198a8e04698SSainath Grandhi int ret, i = 0; 1199a8e04698SSainath Grandhi 1200a8e04698SSainath Grandhi arrays = kmalloc(sizeof *arrays * n, GFP_KERNEL); 1201a8e04698SSainath Grandhi if (!arrays) 1202a8e04698SSainath Grandhi return -ENOMEM; 1203a8e04698SSainath Grandhi 12046fe3faf8SSainath Grandhi list_for_each_entry(q, &tap->queue_list, next) 1205a8e04698SSainath Grandhi arrays[i++] = &q->skb_array; 1206a8e04698SSainath Grandhi 1207a8e04698SSainath Grandhi ret = skb_array_resize_multiple(arrays, n, 1208a8e04698SSainath Grandhi dev->tx_queue_len, GFP_KERNEL); 1209a8e04698SSainath Grandhi 1210a8e04698SSainath Grandhi kfree(arrays); 1211a8e04698SSainath Grandhi return ret; 1212a8e04698SSainath Grandhi } 1213ebc05ba7SSainath Grandhi 1214*d9f1f61cSSainath Grandhi static int tap_list_add(dev_t major, const char *device_name) 1215*d9f1f61cSSainath Grandhi { 1216*d9f1f61cSSainath Grandhi struct major_info *tap_major; 1217*d9f1f61cSSainath Grandhi 1218*d9f1f61cSSainath Grandhi tap_major = kzalloc(sizeof(*tap_major), GFP_ATOMIC); 1219*d9f1f61cSSainath Grandhi if (!tap_major) 1220*d9f1f61cSSainath Grandhi return -ENOMEM; 1221*d9f1f61cSSainath Grandhi 1222*d9f1f61cSSainath Grandhi tap_major->major = MAJOR(major); 1223*d9f1f61cSSainath Grandhi 1224*d9f1f61cSSainath Grandhi idr_init(&tap_major->minor_idr); 1225*d9f1f61cSSainath Grandhi mutex_init(&tap_major->minor_lock); 1226*d9f1f61cSSainath Grandhi 1227*d9f1f61cSSainath Grandhi tap_major->device_name = device_name; 1228*d9f1f61cSSainath Grandhi 1229*d9f1f61cSSainath Grandhi list_add_tail_rcu(&tap_major->next, &major_list); 1230*d9f1f61cSSainath Grandhi return 0; 1231*d9f1f61cSSainath Grandhi } 1232*d9f1f61cSSainath Grandhi 1233ebc05ba7SSainath Grandhi int tap_create_cdev(struct cdev *tap_cdev, 1234ebc05ba7SSainath Grandhi dev_t *tap_major, const char *device_name) 1235ebc05ba7SSainath Grandhi { 1236ebc05ba7SSainath Grandhi int err; 1237ebc05ba7SSainath Grandhi 1238ebc05ba7SSainath Grandhi err = alloc_chrdev_region(tap_major, 0, TAP_NUM_DEVS, device_name); 1239ebc05ba7SSainath Grandhi if (err) 1240ebc05ba7SSainath Grandhi goto out1; 1241ebc05ba7SSainath Grandhi 1242ebc05ba7SSainath Grandhi cdev_init(tap_cdev, &tap_fops); 1243ebc05ba7SSainath Grandhi err = cdev_add(tap_cdev, *tap_major, TAP_NUM_DEVS); 1244ebc05ba7SSainath Grandhi if (err) 1245ebc05ba7SSainath Grandhi goto out2; 1246ebc05ba7SSainath Grandhi 1247*d9f1f61cSSainath Grandhi err = tap_list_add(*tap_major, device_name); 1248*d9f1f61cSSainath Grandhi if (err) 1249*d9f1f61cSSainath Grandhi goto out3; 1250ebc05ba7SSainath Grandhi 1251ebc05ba7SSainath Grandhi return 0; 1252ebc05ba7SSainath Grandhi 1253*d9f1f61cSSainath Grandhi out3: 1254*d9f1f61cSSainath Grandhi cdev_del(tap_cdev); 1255ebc05ba7SSainath Grandhi out2: 1256ebc05ba7SSainath Grandhi unregister_chrdev_region(*tap_major, TAP_NUM_DEVS); 1257ebc05ba7SSainath Grandhi out1: 1258ebc05ba7SSainath Grandhi return err; 1259ebc05ba7SSainath Grandhi } 1260ebc05ba7SSainath Grandhi 1261ebc05ba7SSainath Grandhi void tap_destroy_cdev(dev_t major, struct cdev *tap_cdev) 1262ebc05ba7SSainath Grandhi { 1263*d9f1f61cSSainath Grandhi struct major_info *tap_major, *tmp; 1264*d9f1f61cSSainath Grandhi 1265ebc05ba7SSainath Grandhi cdev_del(tap_cdev); 1266ebc05ba7SSainath Grandhi unregister_chrdev_region(major, TAP_NUM_DEVS); 1267*d9f1f61cSSainath Grandhi list_for_each_entry_safe(tap_major, tmp, &major_list, next) { 1268*d9f1f61cSSainath Grandhi if (tap_major->major == MAJOR(major)) { 1269*d9f1f61cSSainath Grandhi idr_destroy(&tap_major->minor_idr); 1270*d9f1f61cSSainath Grandhi list_del_rcu(&tap_major->next); 1271*d9f1f61cSSainath Grandhi kfree_rcu(tap_major, rcu); 1272*d9f1f61cSSainath Grandhi } 1273*d9f1f61cSSainath Grandhi } 1274ebc05ba7SSainath Grandhi } 1275