Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
20d29d7a | 2 | #include <linux/etherdevice.h> |
6fe3faf8 | 3 | #include <linux/if_tap.h> |
f09e2249 | 4 | #include <linux/if_vlan.h> |
20d29d7a AB |
5 | #include <linux/interrupt.h> |
6 | #include <linux/nsproxy.h> | |
7 | #include <linux/compat.h> | |
8 | #include <linux/if_tun.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/skbuff.h> | |
11 | #include <linux/cache.h> | |
c3edc401 | 12 | #include <linux/sched/signal.h> |
20d29d7a | 13 | #include <linux/types.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
20d29d7a AB |
15 | #include <linux/wait.h> |
16 | #include <linux/cdev.h> | |
40401530 | 17 | #include <linux/idr.h> |
20d29d7a | 18 | #include <linux/fs.h> |
6c36d2e2 | 19 | #include <linux/uio.h> |
20d29d7a AB |
20 | |
21 | #include <net/net_namespace.h> | |
22 | #include <net/rtnetlink.h> | |
23 | #include <net/sock.h> | |
b9fb9ee0 | 24 | #include <linux/virtio_net.h> |
362899b8 | 25 | #include <linux/skb_array.h> |
20d29d7a | 26 | |
635b8c8e | 27 | #define TAP_IFFEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE) |
01b07fb3 | 28 | |
635b8c8e SG |
29 | #define TAP_VNET_LE 0x80000000 |
30 | #define TAP_VNET_BE 0x40000000 | |
8b8e658b GK |
31 | |
32 | #ifdef CONFIG_TUN_VNET_CROSS_LE | |
635b8c8e | 33 | static inline bool tap_legacy_is_little_endian(struct tap_queue *q) |
8b8e658b | 34 | { |
635b8c8e | 35 | return q->flags & TAP_VNET_BE ? false : |
8b8e658b GK |
36 | virtio_legacy_is_little_endian(); |
37 | } | |
38 | ||
635b8c8e | 39 | static long tap_get_vnet_be(struct tap_queue *q, int __user *sp) |
8b8e658b | 40 | { |
635b8c8e | 41 | int s = !!(q->flags & TAP_VNET_BE); |
8b8e658b GK |
42 | |
43 | if (put_user(s, sp)) | |
44 | return -EFAULT; | |
45 | ||
46 | return 0; | |
47 | } | |
48 | ||
635b8c8e | 49 | static long tap_set_vnet_be(struct tap_queue *q, int __user *sp) |
8b8e658b GK |
50 | { |
51 | int s; | |
52 | ||
53 | if (get_user(s, sp)) | |
54 | return -EFAULT; | |
55 | ||
56 | if (s) | |
635b8c8e | 57 | q->flags |= TAP_VNET_BE; |
8b8e658b | 58 | else |
635b8c8e | 59 | q->flags &= ~TAP_VNET_BE; |
8b8e658b GK |
60 | |
61 | return 0; | |
62 | } | |
63 | #else | |
635b8c8e | 64 | static inline bool tap_legacy_is_little_endian(struct tap_queue *q) |
8b8e658b GK |
65 | { |
66 | return virtio_legacy_is_little_endian(); | |
67 | } | |
68 | ||
635b8c8e | 69 | static long tap_get_vnet_be(struct tap_queue *q, int __user *argp) |
8b8e658b GK |
70 | { |
71 | return -EINVAL; | |
72 | } | |
73 | ||
635b8c8e | 74 | static long tap_set_vnet_be(struct tap_queue *q, int __user *argp) |
8b8e658b GK |
75 | { |
76 | return -EINVAL; | |
77 | } | |
78 | #endif /* CONFIG_TUN_VNET_CROSS_LE */ | |
6ae7feb3 | 79 | |
635b8c8e | 80 | static inline bool tap_is_little_endian(struct tap_queue *q) |
5b11e15f | 81 | { |
635b8c8e SG |
82 | return q->flags & TAP_VNET_LE || |
83 | tap_legacy_is_little_endian(q); | |
5b11e15f | 84 | } |
6ae7feb3 | 85 | |
635b8c8e | 86 | static inline u16 tap16_to_cpu(struct tap_queue *q, __virtio16 val) |
6ae7feb3 | 87 | { |
635b8c8e | 88 | return __virtio16_to_cpu(tap_is_little_endian(q), val); |
6ae7feb3 MT |
89 | } |
90 | ||
635b8c8e | 91 | static inline __virtio16 cpu_to_tap16(struct tap_queue *q, u16 val) |
6ae7feb3 | 92 | { |
635b8c8e | 93 | return __cpu_to_virtio16(tap_is_little_endian(q), val); |
6ae7feb3 MT |
94 | } |
95 | ||
635b8c8e SG |
96 | static struct proto tap_proto = { |
97 | .name = "tap", | |
20d29d7a | 98 | .owner = THIS_MODULE, |
635b8c8e | 99 | .obj_size = sizeof(struct tap_queue), |
20d29d7a AB |
100 | }; |
101 | ||
635b8c8e | 102 | #define TAP_NUM_DEVS (1U << MINORBITS) |
d9f1f61c SG |
103 | |
104 | static LIST_HEAD(major_list); | |
105 | ||
ebc05ba7 | 106 | struct major_info { |
d9f1f61c | 107 | struct rcu_head rcu; |
ebc05ba7 SG |
108 | dev_t major; |
109 | struct idr minor_idr; | |
ffa423fb | 110 | spinlock_t minor_lock; |
ebc05ba7 | 111 | const char *device_name; |
d9f1f61c SG |
112 | struct list_head next; |
113 | }; | |
e09eff7f | 114 | |
97bc3633 | 115 | #define GOODCOPY_LEN 128 |
20d29d7a | 116 | |
635b8c8e | 117 | static const struct proto_ops tap_socket_ops; |
501c774c | 118 | |
2be5c767 | 119 | #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO) |
f23d538b | 120 | #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG | NETIF_F_FRAGLIST) |
a567dd62 | 121 | |
6fe3faf8 | 122 | static struct tap_dev *tap_dev_get_rcu(const struct net_device *dev) |
6acf54f1 VY |
123 | { |
124 | return rcu_dereference(dev->rx_handler_data); | |
125 | } | |
126 | ||
20d29d7a AB |
127 | /* |
128 | * RCU usage: | |
635b8c8e | 129 | * The tap_queue and the macvlan_dev are loosely coupled, the |
02df55d2 | 130 | * pointers from one to the other can only be read while rcu_read_lock |
441ac0fc | 131 | * or rtnl is held. |
20d29d7a | 132 | * |
635b8c8e | 133 | * Both the file and the macvlan_dev hold a reference on the tap_queue |
02df55d2 AB |
134 | * through sock_hold(&q->sk). When the macvlan_dev goes away first, |
135 | * q->vlan becomes inaccessible. When the files gets closed, | |
635b8c8e | 136 | * tap_get_queue() fails. |
20d29d7a | 137 | * |
02df55d2 AB |
138 | * There may still be references to the struct sock inside of the |
139 | * queue from outbound SKBs, but these never reference back to the | |
140 | * file or the dev. The data structure is freed through __sk_free | |
141 | * when both our references and any pending SKBs are gone. | |
20d29d7a | 142 | */ |
20d29d7a | 143 | |
6fe3faf8 | 144 | static int tap_enable_queue(struct tap_dev *tap, struct file *file, |
635b8c8e | 145 | struct tap_queue *q) |
815f236d | 146 | { |
815f236d JW |
147 | int err = -EINVAL; |
148 | ||
441ac0fc | 149 | ASSERT_RTNL(); |
815f236d JW |
150 | |
151 | if (q->enabled) | |
152 | goto out; | |
153 | ||
154 | err = 0; | |
6fe3faf8 SG |
155 | rcu_assign_pointer(tap->taps[tap->numvtaps], q); |
156 | q->queue_index = tap->numvtaps; | |
815f236d JW |
157 | q->enabled = true; |
158 | ||
6fe3faf8 | 159 | tap->numvtaps++; |
815f236d | 160 | out: |
815f236d JW |
161 | return err; |
162 | } | |
163 | ||
40b8fe45 | 164 | /* Requires RTNL */ |
6fe3faf8 | 165 | static int tap_set_queue(struct tap_dev *tap, struct file *file, |
635b8c8e | 166 | struct tap_queue *q) |
20d29d7a | 167 | { |
6fe3faf8 | 168 | if (tap->numqueues == MAX_TAP_QUEUES) |
40b8fe45 | 169 | return -EBUSY; |
20d29d7a | 170 | |
6fe3faf8 SG |
171 | rcu_assign_pointer(q->tap, tap); |
172 | rcu_assign_pointer(tap->taps[tap->numvtaps], q); | |
02df55d2 | 173 | sock_hold(&q->sk); |
20d29d7a AB |
174 | |
175 | q->file = file; | |
6fe3faf8 | 176 | q->queue_index = tap->numvtaps; |
815f236d | 177 | q->enabled = true; |
02df55d2 | 178 | file->private_data = q; |
6fe3faf8 | 179 | list_add_tail(&q->next, &tap->queue_list); |
20d29d7a | 180 | |
6fe3faf8 SG |
181 | tap->numvtaps++; |
182 | tap->numqueues++; | |
1565c7c1 | 183 | |
40b8fe45 | 184 | return 0; |
20d29d7a AB |
185 | } |
186 | ||
635b8c8e | 187 | static int tap_disable_queue(struct tap_queue *q) |
815f236d | 188 | { |
6fe3faf8 | 189 | struct tap_dev *tap; |
635b8c8e | 190 | struct tap_queue *nq; |
815f236d | 191 | |
441ac0fc | 192 | ASSERT_RTNL(); |
815f236d JW |
193 | if (!q->enabled) |
194 | return -EINVAL; | |
195 | ||
6fe3faf8 | 196 | tap = rtnl_dereference(q->tap); |
441ac0fc | 197 | |
6fe3faf8 | 198 | if (tap) { |
815f236d | 199 | int index = q->queue_index; |
6fe3faf8 SG |
200 | BUG_ON(index >= tap->numvtaps); |
201 | nq = rtnl_dereference(tap->taps[tap->numvtaps - 1]); | |
815f236d JW |
202 | nq->queue_index = index; |
203 | ||
6fe3faf8 SG |
204 | rcu_assign_pointer(tap->taps[index], nq); |
205 | RCU_INIT_POINTER(tap->taps[tap->numvtaps - 1], NULL); | |
815f236d JW |
206 | q->enabled = false; |
207 | ||
6fe3faf8 | 208 | tap->numvtaps--; |
815f236d JW |
209 | } |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
20d29d7a | 214 | /* |
02df55d2 AB |
215 | * The file owning the queue got closed, give up both |
216 | * the reference that the files holds as well as the | |
217 | * one from the macvlan_dev if that still exists. | |
20d29d7a AB |
218 | * |
219 | * Using the spinlock makes sure that we don't get | |
220 | * to the queue again after destroying it. | |
20d29d7a | 221 | */ |
635b8c8e | 222 | static void tap_put_queue(struct tap_queue *q) |
20d29d7a | 223 | { |
6fe3faf8 | 224 | struct tap_dev *tap; |
20d29d7a | 225 | |
441ac0fc | 226 | rtnl_lock(); |
6fe3faf8 | 227 | tap = rtnl_dereference(q->tap); |
441ac0fc | 228 | |
6fe3faf8 | 229 | if (tap) { |
815f236d | 230 | if (q->enabled) |
635b8c8e | 231 | BUG_ON(tap_disable_queue(q)); |
376b1aab | 232 | |
6fe3faf8 SG |
233 | tap->numqueues--; |
234 | RCU_INIT_POINTER(q->tap, NULL); | |
02df55d2 | 235 | sock_put(&q->sk); |
815f236d | 236 | list_del_init(&q->next); |
20d29d7a AB |
237 | } |
238 | ||
441ac0fc | 239 | rtnl_unlock(); |
20d29d7a AB |
240 | |
241 | synchronize_rcu(); | |
242 | sock_put(&q->sk); | |
243 | } | |
244 | ||
245 | /* | |
1565c7c1 KK |
246 | * Select a queue based on the rxq of the device on which this packet |
247 | * arrived. If the incoming device is not mq, calculate a flow hash | |
248 | * to select a queue. If all fails, find the first available queue. | |
249 | * Cache vlan->numvtaps since it can become zero during the execution | |
250 | * of this function. | |
20d29d7a | 251 | */ |
6fe3faf8 | 252 | static struct tap_queue *tap_get_queue(struct tap_dev *tap, |
635b8c8e | 253 | struct sk_buff *skb) |
20d29d7a | 254 | { |
6fe3faf8 | 255 | struct tap_queue *queue = NULL; |
815f236d JW |
256 | /* Access to taps array is protected by rcu, but access to numvtaps |
257 | * isn't. Below we use it to lookup a queue, but treat it as a hint | |
258 | * and validate that the result isn't NULL - in case we are | |
259 | * racing against queue removal. | |
260 | */ | |
6aa7de05 | 261 | int numvtaps = READ_ONCE(tap->numvtaps); |
1565c7c1 KK |
262 | __u32 rxq; |
263 | ||
264 | if (!numvtaps) | |
265 | goto out; | |
266 | ||
1b16bf42 JW |
267 | if (numvtaps == 1) |
268 | goto single; | |
269 | ||
ef0002b5 | 270 | /* Check if we can use flow to select a queue */ |
3958afa1 | 271 | rxq = skb_get_hash(skb); |
ef0002b5 | 272 | if (rxq) { |
6fe3faf8 | 273 | queue = rcu_dereference(tap->taps[rxq % numvtaps]); |
376b1aab | 274 | goto out; |
ef0002b5 KK |
275 | } |
276 | ||
1565c7c1 KK |
277 | if (likely(skb_rx_queue_recorded(skb))) { |
278 | rxq = skb_get_rx_queue(skb); | |
20d29d7a | 279 | |
1565c7c1 KK |
280 | while (unlikely(rxq >= numvtaps)) |
281 | rxq -= numvtaps; | |
282 | ||
6fe3faf8 | 283 | queue = rcu_dereference(tap->taps[rxq]); |
376b1aab | 284 | goto out; |
1565c7c1 KK |
285 | } |
286 | ||
1b16bf42 | 287 | single: |
6fe3faf8 | 288 | queue = rcu_dereference(tap->taps[0]); |
1565c7c1 | 289 | out: |
6fe3faf8 | 290 | return queue; |
20d29d7a AB |
291 | } |
292 | ||
02df55d2 AB |
293 | /* |
294 | * The net_device is going away, give up the reference | |
1565c7c1 KK |
295 | * that it holds on all queues and safely set the pointer |
296 | * from the queues to NULL. | |
02df55d2 | 297 | */ |
6fe3faf8 | 298 | void tap_del_queues(struct tap_dev *tap) |
20d29d7a | 299 | { |
635b8c8e | 300 | struct tap_queue *q, *tmp; |
02df55d2 | 301 | |
441ac0fc | 302 | ASSERT_RTNL(); |
6fe3faf8 | 303 | list_for_each_entry_safe(q, tmp, &tap->queue_list, next) { |
815f236d | 304 | list_del_init(&q->next); |
6fe3faf8 | 305 | RCU_INIT_POINTER(q->tap, NULL); |
815f236d | 306 | if (q->enabled) |
6fe3faf8 SG |
307 | tap->numvtaps--; |
308 | tap->numqueues--; | |
dfe816c5 | 309 | sock_put(&q->sk); |
564517e8 | 310 | } |
6fe3faf8 SG |
311 | BUG_ON(tap->numvtaps); |
312 | BUG_ON(tap->numqueues); | |
635b8c8e | 313 | /* guarantee that any future tap_set_queue will fail */ |
6fe3faf8 | 314 | tap->numvtaps = MAX_TAP_QUEUES; |
20d29d7a | 315 | } |
9a393b5d | 316 | EXPORT_SYMBOL_GPL(tap_del_queues); |
20d29d7a | 317 | |
635b8c8e | 318 | rx_handler_result_t tap_handle_frame(struct sk_buff **pskb) |
20d29d7a | 319 | { |
6acf54f1 VY |
320 | struct sk_buff *skb = *pskb; |
321 | struct net_device *dev = skb->dev; | |
6fe3faf8 | 322 | struct tap_dev *tap; |
635b8c8e | 323 | struct tap_queue *q; |
a567dd62 | 324 | netdev_features_t features = TAP_FEATURES; |
736f16de | 325 | enum skb_drop_reason drop_reason; |
a567dd62 | 326 | |
6fe3faf8 SG |
327 | tap = tap_dev_get_rcu(dev); |
328 | if (!tap) | |
6acf54f1 VY |
329 | return RX_HANDLER_PASS; |
330 | ||
6fe3faf8 | 331 | q = tap_get_queue(tap, skb); |
20d29d7a | 332 | if (!q) |
6acf54f1 | 333 | return RX_HANDLER_PASS; |
8a35747a | 334 | |
6acf54f1 VY |
335 | skb_push(skb, ETH_HLEN); |
336 | ||
3e4f8b78 | 337 | /* Apply the forward feature mask so that we perform segmentation |
e5733321 VY |
338 | * according to users wishes. This only works if VNET_HDR is |
339 | * enabled. | |
3e4f8b78 | 340 | */ |
e5733321 | 341 | if (q->flags & IFF_VNET_HDR) |
6fe3faf8 | 342 | features |= tap->tap_features; |
8b86a61d | 343 | if (netif_needs_gso(skb, features)) { |
3e4f8b78 | 344 | struct sk_buff *segs = __skb_gso_segment(skb, features, false); |
5643a552 | 345 | struct sk_buff *next; |
3e4f8b78 | 346 | |
736f16de DZ |
347 | if (IS_ERR(segs)) { |
348 | drop_reason = SKB_DROP_REASON_SKB_GSO_SEG; | |
3e4f8b78 | 349 | goto drop; |
736f16de | 350 | } |
3e4f8b78 VY |
351 | |
352 | if (!segs) { | |
736f16de DZ |
353 | if (ptr_ring_produce(&q->ring, skb)) { |
354 | drop_reason = SKB_DROP_REASON_FULL_RING; | |
362899b8 | 355 | goto drop; |
736f16de | 356 | } |
3e4f8b78 VY |
357 | goto wake_up; |
358 | } | |
359 | ||
be0bd316 | 360 | consume_skb(skb); |
5643a552 JD |
361 | skb_list_walk_safe(segs, skb, next) { |
362 | skb_mark_not_on_list(skb); | |
363 | if (ptr_ring_produce(&q->ring, skb)) { | |
736f16de DZ |
364 | drop_reason = SKB_DROP_REASON_FULL_RING; |
365 | kfree_skb_reason(skb, drop_reason); | |
366 | kfree_skb_list_reason(next, drop_reason); | |
362899b8 JW |
367 | break; |
368 | } | |
3e4f8b78 VY |
369 | } |
370 | } else { | |
cbdb0427 VY |
371 | /* If we receive a partial checksum and the tap side |
372 | * doesn't support checksum offload, compute the checksum. | |
373 | * Note: it doesn't matter which checksum feature to | |
a8e04698 | 374 | * check, we either support them all or none. |
cbdb0427 VY |
375 | */ |
376 | if (skb->ip_summed == CHECKSUM_PARTIAL && | |
a188222b | 377 | !(features & NETIF_F_CSUM_MASK) && |
736f16de DZ |
378 | skb_checksum_help(skb)) { |
379 | drop_reason = SKB_DROP_REASON_SKB_CSUM; | |
cbdb0427 | 380 | goto drop; |
736f16de DZ |
381 | } |
382 | if (ptr_ring_produce(&q->ring, skb)) { | |
383 | drop_reason = SKB_DROP_REASON_FULL_RING; | |
362899b8 | 384 | goto drop; |
736f16de | 385 | } |
3e4f8b78 VY |
386 | } |
387 | ||
388 | wake_up: | |
a9a08845 | 389 | wake_up_interruptible_poll(sk_sleep(&q->sk), EPOLLIN | EPOLLRDNORM | EPOLLRDBAND); |
6acf54f1 | 390 | return RX_HANDLER_CONSUMED; |
8a35747a HX |
391 | |
392 | drop: | |
6acf54f1 | 393 | /* Count errors/drops only here, thus don't care about args. */ |
6fe3faf8 SG |
394 | if (tap->count_rx_dropped) |
395 | tap->count_rx_dropped(tap); | |
736f16de | 396 | kfree_skb_reason(skb, drop_reason); |
6acf54f1 | 397 | return RX_HANDLER_CONSUMED; |
20d29d7a | 398 | } |
9a393b5d | 399 | EXPORT_SYMBOL_GPL(tap_handle_frame); |
20d29d7a | 400 | |
d9f1f61c SG |
401 | static struct major_info *tap_get_major(int major) |
402 | { | |
403 | struct major_info *tap_major; | |
404 | ||
405 | list_for_each_entry_rcu(tap_major, &major_list, next) { | |
406 | if (tap_major->major == major) | |
407 | return tap_major; | |
408 | } | |
409 | ||
410 | return NULL; | |
411 | } | |
412 | ||
413 | int tap_get_minor(dev_t major, struct tap_dev *tap) | |
e09eff7f EB |
414 | { |
415 | int retval = -ENOMEM; | |
d9f1f61c SG |
416 | struct major_info *tap_major; |
417 | ||
418 | rcu_read_lock(); | |
419 | tap_major = tap_get_major(MAJOR(major)); | |
420 | if (!tap_major) { | |
421 | retval = -EINVAL; | |
422 | goto unlock; | |
423 | } | |
e09eff7f | 424 | |
ffa423fb WC |
425 | spin_lock(&tap_major->minor_lock); |
426 | retval = idr_alloc(&tap_major->minor_idr, tap, 1, TAP_NUM_DEVS, GFP_ATOMIC); | |
ec09ebc1 | 427 | if (retval >= 0) { |
6fe3faf8 | 428 | tap->minor = retval; |
ec09ebc1 | 429 | } else if (retval == -ENOSPC) { |
6fe3faf8 | 430 | netdev_err(tap->dev, "Too many tap devices\n"); |
e09eff7f | 431 | retval = -EINVAL; |
e09eff7f | 432 | } |
ffa423fb | 433 | spin_unlock(&tap_major->minor_lock); |
d9f1f61c SG |
434 | |
435 | unlock: | |
436 | rcu_read_unlock(); | |
ec09ebc1 | 437 | return retval < 0 ? retval : 0; |
e09eff7f | 438 | } |
9a393b5d | 439 | EXPORT_SYMBOL_GPL(tap_get_minor); |
e09eff7f | 440 | |
d9f1f61c | 441 | void tap_free_minor(dev_t major, struct tap_dev *tap) |
e09eff7f | 442 | { |
d9f1f61c SG |
443 | struct major_info *tap_major; |
444 | ||
445 | rcu_read_lock(); | |
446 | tap_major = tap_get_major(MAJOR(major)); | |
447 | if (!tap_major) { | |
448 | goto unlock; | |
449 | } | |
450 | ||
ffa423fb | 451 | spin_lock(&tap_major->minor_lock); |
6fe3faf8 | 452 | if (tap->minor) { |
d9f1f61c | 453 | idr_remove(&tap_major->minor_idr, tap->minor); |
6fe3faf8 | 454 | tap->minor = 0; |
e09eff7f | 455 | } |
ffa423fb | 456 | spin_unlock(&tap_major->minor_lock); |
d9f1f61c SG |
457 | |
458 | unlock: | |
459 | rcu_read_unlock(); | |
e09eff7f | 460 | } |
9a393b5d | 461 | EXPORT_SYMBOL_GPL(tap_free_minor); |
e09eff7f | 462 | |
d9f1f61c | 463 | static struct tap_dev *dev_get_by_tap_file(int major, int minor) |
e09eff7f EB |
464 | { |
465 | struct net_device *dev = NULL; | |
6fe3faf8 | 466 | struct tap_dev *tap; |
d9f1f61c | 467 | struct major_info *tap_major; |
e09eff7f | 468 | |
d9f1f61c SG |
469 | rcu_read_lock(); |
470 | tap_major = tap_get_major(major); | |
471 | if (!tap_major) { | |
472 | tap = NULL; | |
473 | goto unlock; | |
474 | } | |
475 | ||
ffa423fb | 476 | spin_lock(&tap_major->minor_lock); |
d9f1f61c | 477 | tap = idr_find(&tap_major->minor_idr, minor); |
6fe3faf8 SG |
478 | if (tap) { |
479 | dev = tap->dev; | |
e09eff7f EB |
480 | dev_hold(dev); |
481 | } | |
ffa423fb | 482 | spin_unlock(&tap_major->minor_lock); |
d9f1f61c SG |
483 | |
484 | unlock: | |
485 | rcu_read_unlock(); | |
6fe3faf8 | 486 | return tap; |
e09eff7f EB |
487 | } |
488 | ||
635b8c8e | 489 | static void tap_sock_write_space(struct sock *sk) |
20d29d7a | 490 | { |
43815482 ED |
491 | wait_queue_head_t *wqueue; |
492 | ||
20d29d7a | 493 | if (!sock_writeable(sk) || |
9cd3e072 | 494 | !test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)) |
20d29d7a AB |
495 | return; |
496 | ||
43815482 ED |
497 | wqueue = sk_sleep(sk); |
498 | if (wqueue && waitqueue_active(wqueue)) | |
a9a08845 | 499 | wake_up_interruptible_poll(wqueue, EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND); |
20d29d7a AB |
500 | } |
501 | ||
635b8c8e | 502 | static void tap_sock_destruct(struct sock *sk) |
2259fef0 | 503 | { |
635b8c8e | 504 | struct tap_queue *q = container_of(sk, struct tap_queue, sk); |
362899b8 | 505 | |
5990a305 | 506 | ptr_ring_cleanup(&q->ring, __skb_array_destroy_skb); |
2259fef0 EB |
507 | } |
508 | ||
635b8c8e | 509 | static int tap_open(struct inode *inode, struct file *file) |
20d29d7a AB |
510 | { |
511 | struct net *net = current->nsproxy->net_ns; | |
6fe3faf8 | 512 | struct tap_dev *tap; |
635b8c8e | 513 | struct tap_queue *q; |
40b8fe45 | 514 | int err = -ENODEV; |
20d29d7a | 515 | |
40b8fe45 | 516 | rtnl_lock(); |
d9f1f61c | 517 | tap = dev_get_by_tap_file(imajor(inode), iminor(inode)); |
6fe3faf8 | 518 | if (!tap) |
362899b8 | 519 | goto err; |
20d29d7a | 520 | |
20d29d7a | 521 | err = -ENOMEM; |
635b8c8e SG |
522 | q = (struct tap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, |
523 | &tap_proto, 0); | |
20d29d7a | 524 | if (!q) |
362899b8 | 525 | goto err; |
5990a305 | 526 | if (ptr_ring_init(&q->ring, tap->dev->tx_queue_len, GFP_KERNEL)) { |
78e0ea67 GM |
527 | sk_free(&q->sk); |
528 | goto err; | |
529 | } | |
20d29d7a | 530 | |
333f7909 | 531 | init_waitqueue_head(&q->sock.wq.wait); |
20d29d7a AB |
532 | q->sock.type = SOCK_RAW; |
533 | q->sock.state = SS_CONNECTED; | |
501c774c | 534 | q->sock.file = file; |
635b8c8e | 535 | q->sock.ops = &tap_socket_ops; |
66b2c338 | 536 | sock_init_data_uid(&q->sock, &q->sk, inode->i_uid); |
635b8c8e SG |
537 | q->sk.sk_write_space = tap_sock_write_space; |
538 | q->sk.sk_destruct = tap_sock_destruct; | |
b9fb9ee0 | 539 | q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; |
55afbd08 | 540 | q->vnet_hdr_sz = sizeof(struct virtio_net_hdr); |
20d29d7a | 541 | |
97bc3633 | 542 | /* |
635b8c8e | 543 | * so far only KVM virtio_net uses tap, enable zero copy between |
97bc3633 | 544 | * guest kernel and host kernel when lower device supports zerocopy |
047af9cf EB |
545 | * |
546 | * The macvlan supports zerocopy iff the lower device supports zero | |
547 | * copy so we don't have to look at the lower device directly. | |
97bc3633 | 548 | */ |
6fe3faf8 | 549 | if ((tap->dev->features & NETIF_F_HIGHDMA) && (tap->dev->features & NETIF_F_SG)) |
047af9cf | 550 | sock_set_flag(&q->sk, SOCK_ZEROCOPY); |
97bc3633 | 551 | |
6fe3faf8 | 552 | err = tap_set_queue(tap, file, q); |
78e0ea67 | 553 | if (err) { |
5990a305 | 554 | /* tap_sock_destruct() will take care of freeing ptr_ring */ |
78e0ea67 GM |
555 | goto err_put; |
556 | } | |
20d29d7a | 557 | |
f758bfec JA |
558 | /* tap groks IOCB_NOWAIT just fine, mark it as such */ |
559 | file->f_mode |= FMODE_NOWAIT; | |
560 | ||
6fe3faf8 | 561 | dev_put(tap->dev); |
362899b8 JW |
562 | |
563 | rtnl_unlock(); | |
564 | return err; | |
565 | ||
78e0ea67 | 566 | err_put: |
362899b8 JW |
567 | sock_put(&q->sk); |
568 | err: | |
6fe3faf8 SG |
569 | if (tap) |
570 | dev_put(tap->dev); | |
20d29d7a | 571 | |
40b8fe45 | 572 | rtnl_unlock(); |
20d29d7a AB |
573 | return err; |
574 | } | |
575 | ||
635b8c8e | 576 | static int tap_release(struct inode *inode, struct file *file) |
20d29d7a | 577 | { |
635b8c8e SG |
578 | struct tap_queue *q = file->private_data; |
579 | tap_put_queue(q); | |
20d29d7a AB |
580 | return 0; |
581 | } | |
582 | ||
afc9a42b | 583 | static __poll_t tap_poll(struct file *file, poll_table *wait) |
20d29d7a | 584 | { |
635b8c8e | 585 | struct tap_queue *q = file->private_data; |
a9a08845 | 586 | __poll_t mask = EPOLLERR; |
20d29d7a AB |
587 | |
588 | if (!q) | |
589 | goto out; | |
590 | ||
591 | mask = 0; | |
333f7909 | 592 | poll_wait(file, &q->sock.wq.wait, wait); |
20d29d7a | 593 | |
5990a305 | 594 | if (!ptr_ring_empty(&q->ring)) |
a9a08845 | 595 | mask |= EPOLLIN | EPOLLRDNORM; |
20d29d7a AB |
596 | |
597 | if (sock_writeable(&q->sk) || | |
9cd3e072 | 598 | (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &q->sock.flags) && |
20d29d7a | 599 | sock_writeable(&q->sk))) |
a9a08845 | 600 | mask |= EPOLLOUT | EPOLLWRNORM; |
20d29d7a AB |
601 | |
602 | out: | |
20d29d7a AB |
603 | return mask; |
604 | } | |
605 | ||
635b8c8e SG |
606 | static inline struct sk_buff *tap_alloc_skb(struct sock *sk, size_t prepad, |
607 | size_t len, size_t linear, | |
b9fb9ee0 AB |
608 | int noblock, int *err) |
609 | { | |
610 | struct sk_buff *skb; | |
611 | ||
612 | /* Under a page? Don't bother with paged skb. */ | |
613 | if (prepad + len < PAGE_SIZE || !linear) | |
614 | linear = len; | |
615 | ||
616 | skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, | |
28d64271 | 617 | err, 0); |
b9fb9ee0 AB |
618 | if (!skb) |
619 | return NULL; | |
620 | ||
621 | skb_reserve(skb, prepad); | |
622 | skb_put(skb, linear); | |
623 | skb->data_len = len - linear; | |
624 | skb->len += len - linear; | |
625 | ||
626 | return skb; | |
627 | } | |
628 | ||
2f1d8b9e | 629 | /* Neighbour code has some assumptions on HH_DATA_MOD alignment */ |
635b8c8e | 630 | #define TAP_RESERVE HH_DATA_OFF(ETH_HLEN) |
2f1d8b9e | 631 | |
20d29d7a | 632 | /* Get packet from user space buffer */ |
fe8dd45b | 633 | static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, |
635b8c8e | 634 | struct iov_iter *from, int noblock) |
20d29d7a | 635 | { |
635b8c8e | 636 | int good_linear = SKB_MAX_HEAD(TAP_RESERVE); |
20d29d7a | 637 | struct sk_buff *skb; |
6fe3faf8 | 638 | struct tap_dev *tap; |
f5ff53b4 | 639 | unsigned long total_len = iov_iter_count(from); |
97bc3633 | 640 | unsigned long len = total_len; |
20d29d7a | 641 | int err; |
b9fb9ee0 AB |
642 | struct virtio_net_hdr vnet_hdr = { 0 }; |
643 | int vnet_hdr_len = 0; | |
b92946e2 | 644 | int copylen = 0; |
c5c62f1b | 645 | int depth; |
97bc3633 | 646 | bool zerocopy = false; |
61d46bf9 | 647 | size_t linear; |
736f16de | 648 | enum skb_drop_reason drop_reason; |
b9fb9ee0 AB |
649 | |
650 | if (q->flags & IFF_VNET_HDR) { | |
837585a5 | 651 | vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz); |
b9fb9ee0 AB |
652 | |
653 | err = -EINVAL; | |
ce3c8692 | 654 | if (len < vnet_hdr_len) |
b9fb9ee0 | 655 | goto err; |
ce3c8692 | 656 | len -= vnet_hdr_len; |
b9fb9ee0 | 657 | |
f5ff53b4 | 658 | err = -EFAULT; |
cbbd26b8 | 659 | if (!copy_from_iter_full(&vnet_hdr, sizeof(vnet_hdr), from)) |
b9fb9ee0 | 660 | goto err; |
f5ff53b4 | 661 | iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr)); |
b9fb9ee0 | 662 | if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && |
635b8c8e SG |
663 | tap16_to_cpu(q, vnet_hdr.csum_start) + |
664 | tap16_to_cpu(q, vnet_hdr.csum_offset) + 2 > | |
665 | tap16_to_cpu(q, vnet_hdr.hdr_len)) | |
666 | vnet_hdr.hdr_len = cpu_to_tap16(q, | |
667 | tap16_to_cpu(q, vnet_hdr.csum_start) + | |
668 | tap16_to_cpu(q, vnet_hdr.csum_offset) + 2); | |
b9fb9ee0 | 669 | err = -EINVAL; |
635b8c8e | 670 | if (tap16_to_cpu(q, vnet_hdr.hdr_len) > len) |
b9fb9ee0 AB |
671 | goto err; |
672 | } | |
20d29d7a | 673 | |
b9fb9ee0 | 674 | err = -EINVAL; |
20d29d7a | 675 | if (unlikely(len < ETH_HLEN)) |
b9fb9ee0 | 676 | goto err; |
20d29d7a | 677 | |
fe8dd45b | 678 | if (msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { |
f5ff53b4 AV |
679 | struct iov_iter i; |
680 | ||
6ae7feb3 | 681 | copylen = vnet_hdr.hdr_len ? |
635b8c8e | 682 | tap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN; |
16a3fa28 JW |
683 | if (copylen > good_linear) |
684 | copylen = good_linear; | |
8e2ad411 WB |
685 | else if (copylen < ETH_HLEN) |
686 | copylen = ETH_HLEN; | |
61d46bf9 | 687 | linear = copylen; |
f5ff53b4 AV |
688 | i = *from; |
689 | iov_iter_advance(&i, copylen); | |
690 | if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS) | |
ece793fc JW |
691 | zerocopy = true; |
692 | } | |
693 | ||
694 | if (!zerocopy) { | |
97bc3633 | 695 | copylen = len; |
635b8c8e | 696 | linear = tap16_to_cpu(q, vnet_hdr.hdr_len); |
8e2ad411 | 697 | if (linear > good_linear) |
16a3fa28 | 698 | linear = good_linear; |
8e2ad411 WB |
699 | else if (linear < ETH_HLEN) |
700 | linear = ETH_HLEN; | |
61d46bf9 | 701 | } |
97bc3633 | 702 | |
635b8c8e SG |
703 | skb = tap_alloc_skb(&q->sk, TAP_RESERVE, copylen, |
704 | linear, noblock, &err); | |
02df55d2 AB |
705 | if (!skb) |
706 | goto err; | |
20d29d7a | 707 | |
01d6657b | 708 | if (zerocopy) |
f5ff53b4 | 709 | err = zerocopy_sg_from_iter(skb, from); |
aa196eed | 710 | else |
f5ff53b4 | 711 | err = skb_copy_datagram_from_iter(skb, 0, from, len); |
ece793fc | 712 | |
736f16de DZ |
713 | if (err) { |
714 | drop_reason = SKB_DROP_REASON_SKB_UCOPY_FAULT; | |
b9fb9ee0 | 715 | goto err_kfree; |
736f16de | 716 | } |
20d29d7a AB |
717 | |
718 | skb_set_network_header(skb, ETH_HLEN); | |
b9fb9ee0 AB |
719 | skb_reset_mac_header(skb); |
720 | skb->protocol = eth_hdr(skb)->h_proto; | |
721 | ||
4f61f133 CB |
722 | rcu_read_lock(); |
723 | tap = rcu_dereference(q->tap); | |
724 | if (!tap) { | |
725 | kfree_skb(skb); | |
726 | rcu_read_unlock(); | |
727 | return total_len; | |
728 | } | |
729 | skb->dev = tap->dev; | |
730 | ||
b9fb9ee0 | 731 | if (vnet_hdr_len) { |
fd88d68b | 732 | err = virtio_net_hdr_to_skb(skb, &vnet_hdr, |
635b8c8e | 733 | tap_is_little_endian(q)); |
736f16de | 734 | if (err) { |
4f61f133 | 735 | rcu_read_unlock(); |
736f16de | 736 | drop_reason = SKB_DROP_REASON_DEV_HDR; |
b9fb9ee0 | 737 | goto err_kfree; |
736f16de | 738 | } |
b9fb9ee0 AB |
739 | } |
740 | ||
d2aa125d | 741 | skb_probe_transport_header(skb); |
9b4d669b | 742 | |
c5c62f1b | 743 | /* Move network header to the right position for VLAN tagged packets */ |
b69df260 | 744 | if (eth_type_vlan(skb->protocol) && |
c5c62f1b IV |
745 | __vlan_get_protocol(skb, skb->protocol, &depth) != 0) |
746 | skb_set_network_header(skb, depth); | |
747 | ||
97bc3633 | 748 | /* copy skb_ubuf_info for callback when skb has no error */ |
01d6657b | 749 | if (zerocopy) { |
9ee5e5ad | 750 | skb_zcopy_init(skb, msg_control); |
fe8dd45b JW |
751 | } else if (msg_control) { |
752 | struct ubuf_info *uarg = msg_control; | |
36177832 | 753 | uarg->callback(NULL, uarg, false); |
01d6657b | 754 | } |
aa196eed | 755 | |
4f61f133 | 756 | dev_queue_xmit(skb); |
ac4e4af1 | 757 | rcu_read_unlock(); |
97bc3633 | 758 | return total_len; |
02df55d2 | 759 | |
b9fb9ee0 | 760 | err_kfree: |
736f16de | 761 | kfree_skb_reason(skb, drop_reason); |
b9fb9ee0 | 762 | |
02df55d2 | 763 | err: |
ac4e4af1 | 764 | rcu_read_lock(); |
6fe3faf8 SG |
765 | tap = rcu_dereference(q->tap); |
766 | if (tap && tap->count_tx_dropped) | |
767 | tap->count_tx_dropped(tap); | |
ac4e4af1 | 768 | rcu_read_unlock(); |
02df55d2 | 769 | |
02df55d2 | 770 | return err; |
20d29d7a AB |
771 | } |
772 | ||
635b8c8e | 773 | static ssize_t tap_write_iter(struct kiocb *iocb, struct iov_iter *from) |
20d29d7a AB |
774 | { |
775 | struct file *file = iocb->ki_filp; | |
635b8c8e | 776 | struct tap_queue *q = file->private_data; |
f758bfec JA |
777 | int noblock = 0; |
778 | ||
779 | if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) | |
780 | noblock = 1; | |
20d29d7a | 781 | |
f758bfec | 782 | return tap_get_user(q, NULL, from, noblock); |
20d29d7a AB |
783 | } |
784 | ||
785 | /* Put packet to the user space buffer */ | |
635b8c8e SG |
786 | static ssize_t tap_put_user(struct tap_queue *q, |
787 | const struct sk_buff *skb, | |
788 | struct iov_iter *iter) | |
20d29d7a | 789 | { |
20d29d7a | 790 | int ret; |
b9fb9ee0 | 791 | int vnet_hdr_len = 0; |
f09e2249 | 792 | int vlan_offset = 0; |
6c36d2e2 | 793 | int total; |
b9fb9ee0 AB |
794 | |
795 | if (q->flags & IFF_VNET_HDR) { | |
fd3a8862 | 796 | int vlan_hlen = skb_vlan_tag_present(skb) ? VLAN_HLEN : 0; |
b9fb9ee0 | 797 | struct virtio_net_hdr vnet_hdr; |
fd3a8862 | 798 | |
837585a5 | 799 | vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz); |
6c36d2e2 | 800 | if (iov_iter_count(iter) < vnet_hdr_len) |
b9fb9ee0 AB |
801 | return -EINVAL; |
802 | ||
3e9e40e7 | 803 | if (virtio_net_hdr_from_skb(skb, &vnet_hdr, |
fd3a8862 WB |
804 | tap_is_little_endian(q), true, |
805 | vlan_hlen)) | |
fd88d68b | 806 | BUG(); |
b9fb9ee0 | 807 | |
6c36d2e2 HX |
808 | if (copy_to_iter(&vnet_hdr, sizeof(vnet_hdr), iter) != |
809 | sizeof(vnet_hdr)) | |
b9fb9ee0 | 810 | return -EFAULT; |
7cc76f51 JW |
811 | |
812 | iov_iter_advance(iter, vnet_hdr_len - sizeof(vnet_hdr)); | |
b9fb9ee0 | 813 | } |
6c36d2e2 | 814 | total = vnet_hdr_len; |
ce232ce0 | 815 | total += skb->len; |
f09e2249 | 816 | |
df8a39de | 817 | if (skb_vlan_tag_present(skb)) { |
f09e2249 BG |
818 | struct { |
819 | __be16 h_vlan_proto; | |
820 | __be16 h_vlan_TCI; | |
821 | } veth; | |
0fbe0d47 | 822 | veth.h_vlan_proto = skb->vlan_proto; |
df8a39de | 823 | veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb)); |
f09e2249 BG |
824 | |
825 | vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); | |
ce232ce0 | 826 | total += VLAN_HLEN; |
f09e2249 | 827 | |
6c36d2e2 HX |
828 | ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset); |
829 | if (ret || !iov_iter_count(iter)) | |
f09e2249 BG |
830 | goto done; |
831 | ||
6c36d2e2 HX |
832 | ret = copy_to_iter(&veth, sizeof(veth), iter); |
833 | if (ret != sizeof(veth) || !iov_iter_count(iter)) | |
f09e2249 BG |
834 | goto done; |
835 | } | |
20d29d7a | 836 | |
6c36d2e2 HX |
837 | ret = skb_copy_datagram_iter(skb, vlan_offset, iter, |
838 | skb->len - vlan_offset); | |
20d29d7a | 839 | |
f09e2249 | 840 | done: |
ce232ce0 | 841 | return ret ? ret : total; |
20d29d7a AB |
842 | } |
843 | ||
635b8c8e SG |
844 | static ssize_t tap_do_read(struct tap_queue *q, |
845 | struct iov_iter *to, | |
3b4ba04a | 846 | int noblock, struct sk_buff *skb) |
20d29d7a | 847 | { |
ccf7e72b | 848 | DEFINE_WAIT(wait); |
501c774c | 849 | ssize_t ret = 0; |
20d29d7a | 850 | |
61d78537 | 851 | if (!iov_iter_count(to)) { |
144a6adf | 852 | kfree_skb(skb); |
3af0bfe5 | 853 | return 0; |
61d78537 | 854 | } |
3af0bfe5 | 855 | |
3b4ba04a JW |
856 | if (skb) |
857 | goto put; | |
858 | ||
3af0bfe5 | 859 | while (1) { |
89cee917 JW |
860 | if (!noblock) |
861 | prepare_to_wait(sk_sleep(&q->sk), &wait, | |
862 | TASK_INTERRUPTIBLE); | |
20d29d7a AB |
863 | |
864 | /* Read frames from the queue */ | |
5990a305 | 865 | skb = ptr_ring_consume(&q->ring); |
3af0bfe5 AV |
866 | if (skb) |
867 | break; | |
868 | if (noblock) { | |
869 | ret = -EAGAIN; | |
870 | break; | |
20d29d7a | 871 | } |
3af0bfe5 AV |
872 | if (signal_pending(current)) { |
873 | ret = -ERESTARTSYS; | |
874 | break; | |
875 | } | |
876 | /* Nothing to read, let's sleep */ | |
877 | schedule(); | |
878 | } | |
a499a2e9 VY |
879 | if (!noblock) |
880 | finish_wait(sk_sleep(&q->sk), &wait); | |
881 | ||
3b4ba04a | 882 | put: |
3af0bfe5 | 883 | if (skb) { |
635b8c8e | 884 | ret = tap_put_user(q, skb, to); |
f51a5e82 JW |
885 | if (unlikely(ret < 0)) |
886 | kfree_skb(skb); | |
887 | else | |
888 | consume_skb(skb); | |
20d29d7a | 889 | } |
501c774c AB |
890 | return ret; |
891 | } | |
892 | ||
635b8c8e | 893 | static ssize_t tap_read_iter(struct kiocb *iocb, struct iov_iter *to) |
501c774c AB |
894 | { |
895 | struct file *file = iocb->ki_filp; | |
635b8c8e | 896 | struct tap_queue *q = file->private_data; |
3af0bfe5 | 897 | ssize_t len = iov_iter_count(to), ret; |
f758bfec JA |
898 | int noblock = 0; |
899 | ||
900 | if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) | |
901 | noblock = 1; | |
20d29d7a | 902 | |
f758bfec | 903 | ret = tap_do_read(q, to, noblock, NULL); |
ce232ce0 | 904 | ret = min_t(ssize_t, ret, len); |
e6ebc7f1 ZYW |
905 | if (ret > 0) |
906 | iocb->ki_pos = ret; | |
20d29d7a AB |
907 | return ret; |
908 | } | |
909 | ||
6fe3faf8 | 910 | static struct tap_dev *tap_get_tap_dev(struct tap_queue *q) |
8f475a31 | 911 | { |
6fe3faf8 | 912 | struct tap_dev *tap; |
8f475a31 | 913 | |
441ac0fc | 914 | ASSERT_RTNL(); |
6fe3faf8 SG |
915 | tap = rtnl_dereference(q->tap); |
916 | if (tap) | |
917 | dev_hold(tap->dev); | |
8f475a31 | 918 | |
6fe3faf8 | 919 | return tap; |
8f475a31 JW |
920 | } |
921 | ||
6fe3faf8 | 922 | static void tap_put_tap_dev(struct tap_dev *tap) |
8f475a31 | 923 | { |
6fe3faf8 | 924 | dev_put(tap->dev); |
8f475a31 JW |
925 | } |
926 | ||
635b8c8e | 927 | static int tap_ioctl_set_queue(struct file *file, unsigned int flags) |
815f236d | 928 | { |
635b8c8e | 929 | struct tap_queue *q = file->private_data; |
6fe3faf8 | 930 | struct tap_dev *tap; |
815f236d JW |
931 | int ret; |
932 | ||
6fe3faf8 SG |
933 | tap = tap_get_tap_dev(q); |
934 | if (!tap) | |
815f236d JW |
935 | return -EINVAL; |
936 | ||
937 | if (flags & IFF_ATTACH_QUEUE) | |
6fe3faf8 | 938 | ret = tap_enable_queue(tap, file, q); |
815f236d | 939 | else if (flags & IFF_DETACH_QUEUE) |
635b8c8e | 940 | ret = tap_disable_queue(q); |
f57855a5 JW |
941 | else |
942 | ret = -EINVAL; | |
815f236d | 943 | |
6fe3faf8 | 944 | tap_put_tap_dev(tap); |
815f236d JW |
945 | return ret; |
946 | } | |
947 | ||
635b8c8e | 948 | static int set_offload(struct tap_queue *q, unsigned long arg) |
2be5c767 | 949 | { |
6fe3faf8 | 950 | struct tap_dev *tap; |
2be5c767 VY |
951 | netdev_features_t features; |
952 | netdev_features_t feature_mask = 0; | |
953 | ||
6fe3faf8 SG |
954 | tap = rtnl_dereference(q->tap); |
955 | if (!tap) | |
2be5c767 VY |
956 | return -ENOLINK; |
957 | ||
6fe3faf8 | 958 | features = tap->dev->features; |
2be5c767 VY |
959 | |
960 | if (arg & TUN_F_CSUM) { | |
961 | feature_mask = NETIF_F_HW_CSUM; | |
962 | ||
963 | if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) { | |
964 | if (arg & TUN_F_TSO_ECN) | |
965 | feature_mask |= NETIF_F_TSO_ECN; | |
966 | if (arg & TUN_F_TSO4) | |
967 | feature_mask |= NETIF_F_TSO; | |
968 | if (arg & TUN_F_TSO6) | |
969 | feature_mask |= NETIF_F_TSO6; | |
970 | } | |
399e0827 AM |
971 | |
972 | /* TODO: for now USO4 and USO6 should work simultaneously */ | |
973 | if ((arg & (TUN_F_USO4 | TUN_F_USO6)) == (TUN_F_USO4 | TUN_F_USO6)) | |
974 | features |= NETIF_F_GSO_UDP_L4; | |
2be5c767 VY |
975 | } |
976 | ||
977 | /* tun/tap driver inverts the usage for TSO offloads, where | |
978 | * setting the TSO bit means that the userspace wants to | |
979 | * accept TSO frames and turning it off means that user space | |
980 | * does not support TSO. | |
635b8c8e | 981 | * For tap, we have to invert it to mean the same thing. |
2be5c767 VY |
982 | * When user space turns off TSO, we turn off GSO/LRO so that |
983 | * user-space will not receive TSO frames. | |
984 | */ | |
399e0827 AM |
985 | if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6) || |
986 | (feature_mask & (TUN_F_USO4 | TUN_F_USO6)) == (TUN_F_USO4 | TUN_F_USO6)) | |
2be5c767 VY |
987 | features |= RX_OFFLOADS; |
988 | else | |
989 | features &= ~RX_OFFLOADS; | |
990 | ||
991 | /* tap_features are the same as features on tun/tap and | |
992 | * reflect user expectations. | |
993 | */ | |
6fe3faf8 SG |
994 | tap->tap_features = feature_mask; |
995 | if (tap->update_features) | |
996 | tap->update_features(tap, features); | |
2be5c767 VY |
997 | |
998 | return 0; | |
999 | } | |
1000 | ||
20d29d7a AB |
1001 | /* |
1002 | * provide compatibility with generic tun/tap interface | |
1003 | */ | |
635b8c8e SG |
1004 | static long tap_ioctl(struct file *file, unsigned int cmd, |
1005 | unsigned long arg) | |
20d29d7a | 1006 | { |
635b8c8e | 1007 | struct tap_queue *q = file->private_data; |
6fe3faf8 | 1008 | struct tap_dev *tap; |
20d29d7a AB |
1009 | void __user *argp = (void __user *)arg; |
1010 | struct ifreq __user *ifr = argp; | |
1011 | unsigned int __user *up = argp; | |
39ec7de7 | 1012 | unsigned short u; |
55afbd08 | 1013 | int __user *sp = argp; |
7f460d30 | 1014 | struct sockaddr sa; |
55afbd08 | 1015 | int s; |
02df55d2 | 1016 | int ret; |
20d29d7a AB |
1017 | |
1018 | switch (cmd) { | |
1019 | case TUNSETIFF: | |
1020 | /* ignore the name, just look at flags */ | |
1021 | if (get_user(u, &ifr->ifr_flags)) | |
1022 | return -EFAULT; | |
b9fb9ee0 AB |
1023 | |
1024 | ret = 0; | |
635b8c8e | 1025 | if ((u & ~TAP_IFFEATURES) != (IFF_NO_PI | IFF_TAP)) |
b9fb9ee0 AB |
1026 | ret = -EINVAL; |
1027 | else | |
635b8c8e | 1028 | q->flags = (q->flags & ~TAP_IFFEATURES) | u; |
b9fb9ee0 AB |
1029 | |
1030 | return ret; | |
20d29d7a AB |
1031 | |
1032 | case TUNGETIFF: | |
441ac0fc | 1033 | rtnl_lock(); |
6fe3faf8 SG |
1034 | tap = tap_get_tap_dev(q); |
1035 | if (!tap) { | |
441ac0fc | 1036 | rtnl_unlock(); |
20d29d7a | 1037 | return -ENOLINK; |
441ac0fc | 1038 | } |
20d29d7a | 1039 | |
02df55d2 | 1040 | ret = 0; |
39ec7de7 | 1041 | u = q->flags; |
6fe3faf8 | 1042 | if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) || |
39ec7de7 | 1043 | put_user(u, &ifr->ifr_flags)) |
02df55d2 | 1044 | ret = -EFAULT; |
6fe3faf8 | 1045 | tap_put_tap_dev(tap); |
441ac0fc | 1046 | rtnl_unlock(); |
02df55d2 | 1047 | return ret; |
20d29d7a | 1048 | |
815f236d JW |
1049 | case TUNSETQUEUE: |
1050 | if (get_user(u, &ifr->ifr_flags)) | |
1051 | return -EFAULT; | |
441ac0fc | 1052 | rtnl_lock(); |
635b8c8e | 1053 | ret = tap_ioctl_set_queue(file, u); |
441ac0fc | 1054 | rtnl_unlock(); |
82a19eb8 | 1055 | return ret; |
815f236d | 1056 | |
20d29d7a | 1057 | case TUNGETFEATURES: |
635b8c8e | 1058 | if (put_user(IFF_TAP | IFF_NO_PI | TAP_IFFEATURES, up)) |
20d29d7a AB |
1059 | return -EFAULT; |
1060 | return 0; | |
1061 | ||
1062 | case TUNSETSNDBUF: | |
3ea79249 | 1063 | if (get_user(s, sp)) |
20d29d7a | 1064 | return -EFAULT; |
93161922 CG |
1065 | if (s <= 0) |
1066 | return -EINVAL; | |
20d29d7a | 1067 | |
3ea79249 | 1068 | q->sk.sk_sndbuf = s; |
20d29d7a AB |
1069 | return 0; |
1070 | ||
55afbd08 MT |
1071 | case TUNGETVNETHDRSZ: |
1072 | s = q->vnet_hdr_sz; | |
1073 | if (put_user(s, sp)) | |
1074 | return -EFAULT; | |
1075 | return 0; | |
1076 | ||
1077 | case TUNSETVNETHDRSZ: | |
1078 | if (get_user(s, sp)) | |
1079 | return -EFAULT; | |
1080 | if (s < (int)sizeof(struct virtio_net_hdr)) | |
1081 | return -EINVAL; | |
1082 | ||
1083 | q->vnet_hdr_sz = s; | |
1084 | return 0; | |
1085 | ||
01b07fb3 | 1086 | case TUNGETVNETLE: |
635b8c8e | 1087 | s = !!(q->flags & TAP_VNET_LE); |
01b07fb3 MT |
1088 | if (put_user(s, sp)) |
1089 | return -EFAULT; | |
1090 | return 0; | |
1091 | ||
1092 | case TUNSETVNETLE: | |
1093 | if (get_user(s, sp)) | |
1094 | return -EFAULT; | |
1095 | if (s) | |
635b8c8e | 1096 | q->flags |= TAP_VNET_LE; |
01b07fb3 | 1097 | else |
635b8c8e | 1098 | q->flags &= ~TAP_VNET_LE; |
01b07fb3 MT |
1099 | return 0; |
1100 | ||
8b8e658b | 1101 | case TUNGETVNETBE: |
635b8c8e | 1102 | return tap_get_vnet_be(q, sp); |
8b8e658b GK |
1103 | |
1104 | case TUNSETVNETBE: | |
635b8c8e | 1105 | return tap_set_vnet_be(q, sp); |
8b8e658b | 1106 | |
20d29d7a AB |
1107 | case TUNSETOFFLOAD: |
1108 | /* let the user check for future flags */ | |
1109 | if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | | |
399e0827 AM |
1110 | TUN_F_TSO_ECN | TUN_F_UFO | |
1111 | TUN_F_USO4 | TUN_F_USO6)) | |
20d29d7a AB |
1112 | return -EINVAL; |
1113 | ||
2be5c767 VY |
1114 | rtnl_lock(); |
1115 | ret = set_offload(q, arg); | |
1116 | rtnl_unlock(); | |
1117 | return ret; | |
20d29d7a | 1118 | |
b5082083 JC |
1119 | case SIOCGIFHWADDR: |
1120 | rtnl_lock(); | |
6fe3faf8 SG |
1121 | tap = tap_get_tap_dev(q); |
1122 | if (!tap) { | |
b5082083 JC |
1123 | rtnl_unlock(); |
1124 | return -ENOLINK; | |
1125 | } | |
1126 | ret = 0; | |
3b23a32a | 1127 | dev_get_mac_address(&sa, dev_net(tap->dev), tap->dev->name); |
6fe3faf8 | 1128 | if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) || |
3b23a32a | 1129 | copy_to_user(&ifr->ifr_hwaddr, &sa, sizeof(sa))) |
b5082083 | 1130 | ret = -EFAULT; |
6fe3faf8 | 1131 | tap_put_tap_dev(tap); |
b5082083 JC |
1132 | rtnl_unlock(); |
1133 | return ret; | |
1134 | ||
1135 | case SIOCSIFHWADDR: | |
7f460d30 JC |
1136 | if (copy_from_user(&sa, &ifr->ifr_hwaddr, sizeof(sa))) |
1137 | return -EFAULT; | |
b5082083 | 1138 | rtnl_lock(); |
6fe3faf8 SG |
1139 | tap = tap_get_tap_dev(q); |
1140 | if (!tap) { | |
b5082083 JC |
1141 | rtnl_unlock(); |
1142 | return -ENOLINK; | |
1143 | } | |
3b23a32a | 1144 | ret = dev_set_mac_address_user(tap->dev, &sa, NULL); |
6fe3faf8 | 1145 | tap_put_tap_dev(tap); |
b5082083 JC |
1146 | rtnl_unlock(); |
1147 | return ret; | |
1148 | ||
20d29d7a AB |
1149 | default: |
1150 | return -EINVAL; | |
1151 | } | |
1152 | } | |
1153 | ||
d17eb73b | 1154 | static const struct file_operations tap_fops = { |
20d29d7a | 1155 | .owner = THIS_MODULE, |
635b8c8e SG |
1156 | .open = tap_open, |
1157 | .release = tap_release, | |
1158 | .read_iter = tap_read_iter, | |
1159 | .write_iter = tap_write_iter, | |
1160 | .poll = tap_poll, | |
20d29d7a | 1161 | .llseek = no_llseek, |
635b8c8e | 1162 | .unlocked_ioctl = tap_ioctl, |
407e9ef7 | 1163 | .compat_ioctl = compat_ptr_ioctl, |
20d29d7a AB |
1164 | }; |
1165 | ||
0efac277 JW |
1166 | static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp) |
1167 | { | |
1168 | struct tun_xdp_hdr *hdr = xdp->data_hard_start; | |
1169 | struct virtio_net_hdr *gso = &hdr->gso; | |
1170 | int buflen = hdr->buflen; | |
1171 | int vnet_hdr_len = 0; | |
1172 | struct tap_dev *tap; | |
1173 | struct sk_buff *skb; | |
1174 | int err, depth; | |
1175 | ||
1176 | if (q->flags & IFF_VNET_HDR) | |
1177 | vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz); | |
1178 | ||
1179 | skb = build_skb(xdp->data_hard_start, buflen); | |
1180 | if (!skb) { | |
1181 | err = -ENOMEM; | |
1182 | goto err; | |
1183 | } | |
1184 | ||
1185 | skb_reserve(skb, xdp->data - xdp->data_hard_start); | |
1186 | skb_put(skb, xdp->data_end - xdp->data); | |
1187 | ||
1188 | skb_set_network_header(skb, ETH_HLEN); | |
1189 | skb_reset_mac_header(skb); | |
1190 | skb->protocol = eth_hdr(skb)->h_proto; | |
1191 | ||
1192 | if (vnet_hdr_len) { | |
1193 | err = virtio_net_hdr_to_skb(skb, gso, tap_is_little_endian(q)); | |
1194 | if (err) | |
1195 | goto err_kfree; | |
1196 | } | |
1197 | ||
0efac277 | 1198 | /* Move network header to the right position for VLAN tagged packets */ |
b69df260 | 1199 | if (eth_type_vlan(skb->protocol) && |
0efac277 JW |
1200 | __vlan_get_protocol(skb, skb->protocol, &depth) != 0) |
1201 | skb_set_network_header(skb, depth); | |
1202 | ||
1203 | rcu_read_lock(); | |
1204 | tap = rcu_dereference(q->tap); | |
1205 | if (tap) { | |
1206 | skb->dev = tap->dev; | |
d2aa125d | 1207 | skb_probe_transport_header(skb); |
0efac277 JW |
1208 | dev_queue_xmit(skb); |
1209 | } else { | |
1210 | kfree_skb(skb); | |
1211 | } | |
1212 | rcu_read_unlock(); | |
1213 | ||
1214 | return 0; | |
1215 | ||
1216 | err_kfree: | |
1217 | kfree_skb(skb); | |
1218 | err: | |
1219 | rcu_read_lock(); | |
faeacb6d | 1220 | tap = rcu_dereference(q->tap); |
0efac277 JW |
1221 | if (tap && tap->count_tx_dropped) |
1222 | tap->count_tx_dropped(tap); | |
1223 | rcu_read_unlock(); | |
1224 | return err; | |
1225 | } | |
1226 | ||
635b8c8e SG |
1227 | static int tap_sendmsg(struct socket *sock, struct msghdr *m, |
1228 | size_t total_len) | |
501c774c | 1229 | { |
635b8c8e | 1230 | struct tap_queue *q = container_of(sock, struct tap_queue, sock); |
fe8dd45b | 1231 | struct tun_msg_ctl *ctl = m->msg_control; |
0efac277 JW |
1232 | struct xdp_buff *xdp; |
1233 | int i; | |
fe8dd45b | 1234 | |
74a335a0 HH |
1235 | if (m->msg_controllen == sizeof(struct tun_msg_ctl) && |
1236 | ctl && ctl->type == TUN_MSG_PTR) { | |
0efac277 JW |
1237 | for (i = 0; i < ctl->num; i++) { |
1238 | xdp = &((struct xdp_buff *)ctl->ptr)[i]; | |
1239 | tap_get_user_xdp(q, xdp); | |
1240 | } | |
1241 | return 0; | |
1242 | } | |
fe8dd45b JW |
1243 | |
1244 | return tap_get_user(q, ctl ? ctl->ptr : NULL, &m->msg_iter, | |
1245 | m->msg_flags & MSG_DONTWAIT); | |
501c774c AB |
1246 | } |
1247 | ||
635b8c8e SG |
1248 | static int tap_recvmsg(struct socket *sock, struct msghdr *m, |
1249 | size_t total_len, int flags) | |
501c774c | 1250 | { |
635b8c8e | 1251 | struct tap_queue *q = container_of(sock, struct tap_queue, sock); |
61d78537 | 1252 | struct sk_buff *skb = m->msg_control; |
501c774c | 1253 | int ret; |
61d78537 | 1254 | if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) { |
144a6adf | 1255 | kfree_skb(skb); |
501c774c | 1256 | return -EINVAL; |
61d78537 WX |
1257 | } |
1258 | ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT, skb); | |
de2aa476 DM |
1259 | if (ret > total_len) { |
1260 | m->msg_flags |= MSG_TRUNC; | |
1261 | ret = flags & MSG_TRUNC ? ret : total_len; | |
1262 | } | |
501c774c AB |
1263 | return ret; |
1264 | } | |
1265 | ||
635b8c8e | 1266 | static int tap_peek_len(struct socket *sock) |
362899b8 | 1267 | { |
635b8c8e | 1268 | struct tap_queue *q = container_of(sock, struct tap_queue, |
362899b8 | 1269 | sock); |
5990a305 | 1270 | return PTR_RING_PEEK_CALL(&q->ring, __skb_array_len_with_tag); |
362899b8 JW |
1271 | } |
1272 | ||
501c774c | 1273 | /* Ops structure to mimic raw sockets with tun */ |
635b8c8e SG |
1274 | static const struct proto_ops tap_socket_ops = { |
1275 | .sendmsg = tap_sendmsg, | |
1276 | .recvmsg = tap_recvmsg, | |
1277 | .peek_len = tap_peek_len, | |
501c774c AB |
1278 | }; |
1279 | ||
1280 | /* Get an underlying socket object from tun file. Returns error unless file is | |
1281 | * attached to a device. The returned object works like a packet socket, it | |
1282 | * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for | |
1283 | * holding a reference to the file for as long as the socket is in use. */ | |
635b8c8e | 1284 | struct socket *tap_get_socket(struct file *file) |
501c774c | 1285 | { |
635b8c8e SG |
1286 | struct tap_queue *q; |
1287 | if (file->f_op != &tap_fops) | |
501c774c AB |
1288 | return ERR_PTR(-EINVAL); |
1289 | q = file->private_data; | |
1290 | if (!q) | |
1291 | return ERR_PTR(-EBADFD); | |
1292 | return &q->sock; | |
1293 | } | |
635b8c8e | 1294 | EXPORT_SYMBOL_GPL(tap_get_socket); |
501c774c | 1295 | |
5990a305 | 1296 | struct ptr_ring *tap_get_ptr_ring(struct file *file) |
49f96fd0 JW |
1297 | { |
1298 | struct tap_queue *q; | |
1299 | ||
1300 | if (file->f_op != &tap_fops) | |
1301 | return ERR_PTR(-EINVAL); | |
1302 | q = file->private_data; | |
1303 | if (!q) | |
1304 | return ERR_PTR(-EBADFD); | |
5990a305 | 1305 | return &q->ring; |
49f96fd0 | 1306 | } |
5990a305 | 1307 | EXPORT_SYMBOL_GPL(tap_get_ptr_ring); |
49f96fd0 | 1308 | |
6fe3faf8 | 1309 | int tap_queue_resize(struct tap_dev *tap) |
362899b8 | 1310 | { |
6fe3faf8 | 1311 | struct net_device *dev = tap->dev; |
635b8c8e | 1312 | struct tap_queue *q; |
5990a305 | 1313 | struct ptr_ring **rings; |
6fe3faf8 | 1314 | int n = tap->numqueues; |
362899b8 JW |
1315 | int ret, i = 0; |
1316 | ||
5990a305 JW |
1317 | rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL); |
1318 | if (!rings) | |
362899b8 JW |
1319 | return -ENOMEM; |
1320 | ||
6fe3faf8 | 1321 | list_for_each_entry(q, &tap->queue_list, next) |
5990a305 | 1322 | rings[i++] = &q->ring; |
362899b8 | 1323 | |
5990a305 JW |
1324 | ret = ptr_ring_resize_multiple(rings, n, |
1325 | dev->tx_queue_len, GFP_KERNEL, | |
1326 | __skb_array_destroy_skb); | |
362899b8 | 1327 | |
5990a305 | 1328 | kfree(rings); |
362899b8 JW |
1329 | return ret; |
1330 | } | |
9a393b5d | 1331 | EXPORT_SYMBOL_GPL(tap_queue_resize); |
ebc05ba7 | 1332 | |
d9f1f61c SG |
1333 | static int tap_list_add(dev_t major, const char *device_name) |
1334 | { | |
1335 | struct major_info *tap_major; | |
1336 | ||
1337 | tap_major = kzalloc(sizeof(*tap_major), GFP_ATOMIC); | |
1338 | if (!tap_major) | |
1339 | return -ENOMEM; | |
1340 | ||
1341 | tap_major->major = MAJOR(major); | |
1342 | ||
1343 | idr_init(&tap_major->minor_idr); | |
ffa423fb | 1344 | spin_lock_init(&tap_major->minor_lock); |
d9f1f61c SG |
1345 | |
1346 | tap_major->device_name = device_name; | |
1347 | ||
1348 | list_add_tail_rcu(&tap_major->next, &major_list); | |
1349 | return 0; | |
1350 | } | |
1351 | ||
dea6e19f GM |
1352 | int tap_create_cdev(struct cdev *tap_cdev, dev_t *tap_major, |
1353 | const char *device_name, struct module *module) | |
ebc05ba7 SG |
1354 | { |
1355 | int err; | |
1356 | ||
1357 | err = alloc_chrdev_region(tap_major, 0, TAP_NUM_DEVS, device_name); | |
1358 | if (err) | |
1359 | goto out1; | |
1360 | ||
1361 | cdev_init(tap_cdev, &tap_fops); | |
dea6e19f | 1362 | tap_cdev->owner = module; |
ebc05ba7 SG |
1363 | err = cdev_add(tap_cdev, *tap_major, TAP_NUM_DEVS); |
1364 | if (err) | |
1365 | goto out2; | |
1366 | ||
d9f1f61c SG |
1367 | err = tap_list_add(*tap_major, device_name); |
1368 | if (err) | |
1369 | goto out3; | |
ebc05ba7 SG |
1370 | |
1371 | return 0; | |
1372 | ||
d9f1f61c SG |
1373 | out3: |
1374 | cdev_del(tap_cdev); | |
ebc05ba7 SG |
1375 | out2: |
1376 | unregister_chrdev_region(*tap_major, TAP_NUM_DEVS); | |
1377 | out1: | |
1378 | return err; | |
1379 | } | |
9a393b5d | 1380 | EXPORT_SYMBOL_GPL(tap_create_cdev); |
ebc05ba7 SG |
1381 | |
1382 | void tap_destroy_cdev(dev_t major, struct cdev *tap_cdev) | |
1383 | { | |
d9f1f61c SG |
1384 | struct major_info *tap_major, *tmp; |
1385 | ||
ebc05ba7 SG |
1386 | cdev_del(tap_cdev); |
1387 | unregister_chrdev_region(major, TAP_NUM_DEVS); | |
d9f1f61c SG |
1388 | list_for_each_entry_safe(tap_major, tmp, &major_list, next) { |
1389 | if (tap_major->major == MAJOR(major)) { | |
1390 | idr_destroy(&tap_major->minor_idr); | |
1391 | list_del_rcu(&tap_major->next); | |
1392 | kfree_rcu(tap_major, rcu); | |
1393 | } | |
1394 | } | |
ebc05ba7 | 1395 | } |
9a393b5d SG |
1396 | EXPORT_SYMBOL_GPL(tap_destroy_cdev); |
1397 | ||
1398 | MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); | |
1399 | MODULE_AUTHOR("Sainath Grandhi <sainath.grandhi@intel.com>"); | |
1400 | MODULE_LICENSE("GPL"); |