1 | // SPDX-License-Identifier: GPL-2.0-or-later |
---|---|
2 | /* |
3 | * TUN - Universal TUN/TAP device driver. |
4 | * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com> |
5 | * |
6 | * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $ |
7 | */ |
8 | |
9 | /* |
10 | * Changes: |
11 | * |
12 | * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14 |
13 | * Add TUNSETLINK ioctl to set the link encapsulation |
14 | * |
15 | * Mark Smith <markzzzsmith@yahoo.com.au> |
16 | * Use eth_random_addr() for tap MAC address. |
17 | * |
18 | * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20 |
19 | * Fixes in packet dropping, queue length setting and queue wakeup. |
20 | * Increased default tx queue length. |
21 | * Added ethtool API. |
22 | * Minor cleanups |
23 | * |
24 | * Daniel Podlejski <underley@underley.eu.org> |
25 | * Modifications for 2.3.99-pre5 kernel. |
26 | */ |
27 | |
28 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
29 | |
30 | #define DRV_NAME "tun" |
31 | #define DRV_VERSION "1.6" |
32 | #define DRV_DESCRIPTION "Universal TUN/TAP device driver" |
33 | #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>" |
34 | |
35 | #include <linux/module.h> |
36 | #include <linux/errno.h> |
37 | #include <linux/kernel.h> |
38 | #include <linux/sched/signal.h> |
39 | #include <linux/major.h> |
40 | #include <linux/slab.h> |
41 | #include <linux/poll.h> |
42 | #include <linux/fcntl.h> |
43 | #include <linux/init.h> |
44 | #include <linux/skbuff.h> |
45 | #include <linux/netdevice.h> |
46 | #include <linux/etherdevice.h> |
47 | #include <linux/miscdevice.h> |
48 | #include <linux/ethtool.h> |
49 | #include <linux/rtnetlink.h> |
50 | #include <linux/compat.h> |
51 | #include <linux/if.h> |
52 | #include <linux/if_arp.h> |
53 | #include <linux/if_ether.h> |
54 | #include <linux/if_tun.h> |
55 | #include <linux/if_vlan.h> |
56 | #include <linux/crc32.h> |
57 | #include <linux/math.h> |
58 | #include <linux/nsproxy.h> |
59 | #include <linux/virtio_net.h> |
60 | #include <linux/rcupdate.h> |
61 | #include <net/net_namespace.h> |
62 | #include <net/netns/generic.h> |
63 | #include <net/rtnetlink.h> |
64 | #include <net/sock.h> |
65 | #include <net/xdp.h> |
66 | #include <net/ip_tunnels.h> |
67 | #include <linux/seq_file.h> |
68 | #include <linux/uio.h> |
69 | #include <linux/skb_array.h> |
70 | #include <linux/bpf.h> |
71 | #include <linux/bpf_trace.h> |
72 | #include <linux/mutex.h> |
73 | #include <linux/ieee802154.h> |
74 | #include <uapi/linux/if_ltalk.h> |
75 | #include <uapi/linux/if_fddi.h> |
76 | #include <uapi/linux/if_hippi.h> |
77 | #include <uapi/linux/if_fc.h> |
78 | #include <net/ax25.h> |
79 | #include <net/rose.h> |
80 | #include <net/6lowpan.h> |
81 | #include <net/rps.h> |
82 | |
83 | #include <linux/uaccess.h> |
84 | #include <linux/proc_fs.h> |
85 | |
86 | #include "tun_vnet.h" |
87 | |
88 | static void tun_default_link_ksettings(struct net_device *dev, |
89 | struct ethtool_link_ksettings *cmd); |
90 | |
91 | #define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD) |
92 | |
93 | /* TUN device flags */ |
94 | |
95 | /* IFF_ATTACH_QUEUE is never stored in device flags, |
96 | * overload it to mean fasync when stored there. |
97 | */ |
98 | #define TUN_FASYNC IFF_ATTACH_QUEUE |
99 | |
100 | #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \ |
101 | IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS) |
102 | |
103 | #define GOODCOPY_LEN 128 |
104 | |
105 | #define FLT_EXACT_COUNT 8 |
106 | struct tap_filter { |
107 | unsigned int count; /* Number of addrs. Zero means disabled */ |
108 | u32 mask[2]; /* Mask of the hashed addrs */ |
109 | unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; |
110 | }; |
111 | |
112 | /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal |
113 | * to max number of VCPUs in guest. */ |
114 | #define MAX_TAP_QUEUES 256 |
115 | #define MAX_TAP_FLOWS 4096 |
116 | |
117 | #define TUN_FLOW_EXPIRE (3 * HZ) |
118 | |
119 | /* A tun_file connects an open character device to a tuntap netdevice. It |
120 | * also contains all socket related structures (except sock_fprog and tap_filter) |
121 | * to serve as one transmit queue for tuntap device. The sock_fprog and |
122 | * tap_filter were kept in tun_struct since they were used for filtering for the |
123 | * netdevice not for a specific queue (at least I didn't see the requirement for |
124 | * this). |
125 | * |
126 | * RCU usage: |
127 | * The tun_file and tun_struct are loosely coupled, the pointer from one to the |
128 | * other can only be read while rcu_read_lock or rtnl_lock is held. |
129 | */ |
130 | struct tun_file { |
131 | struct sock sk; |
132 | struct socket socket; |
133 | struct tun_struct __rcu *tun; |
134 | struct fasync_struct *fasync; |
135 | /* only used for fasnyc */ |
136 | unsigned int flags; |
137 | union { |
138 | u16 queue_index; |
139 | unsigned int ifindex; |
140 | }; |
141 | struct napi_struct napi; |
142 | bool napi_enabled; |
143 | bool napi_frags_enabled; |
144 | struct mutex napi_mutex; /* Protects access to the above napi */ |
145 | struct list_head next; |
146 | struct tun_struct *detached; |
147 | struct ptr_ring tx_ring; |
148 | struct xdp_rxq_info xdp_rxq; |
149 | }; |
150 | |
151 | struct tun_page { |
152 | struct page *page; |
153 | int count; |
154 | }; |
155 | |
156 | struct tun_flow_entry { |
157 | struct hlist_node hash_link; |
158 | struct rcu_head rcu; |
159 | struct tun_struct *tun; |
160 | |
161 | u32 rxhash; |
162 | u32 rps_rxhash; |
163 | int queue_index; |
164 | unsigned long updated ____cacheline_aligned_in_smp; |
165 | }; |
166 | |
167 | #define TUN_NUM_FLOW_ENTRIES 1024 |
168 | #define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1) |
169 | |
170 | struct tun_prog { |
171 | struct rcu_head rcu; |
172 | struct bpf_prog *prog; |
173 | }; |
174 | |
175 | /* Since the socket were moved to tun_file, to preserve the behavior of persist |
176 | * device, socket filter, sndbuf and vnet header size were restore when the |
177 | * file were attached to a persist device. |
178 | */ |
179 | struct tun_struct { |
180 | struct tun_file __rcu *tfiles[MAX_TAP_QUEUES]; |
181 | unsigned int numqueues; |
182 | unsigned int flags; |
183 | kuid_t owner; |
184 | kgid_t group; |
185 | |
186 | struct net_device *dev; |
187 | netdev_features_t set_features; |
188 | #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \ |
189 | NETIF_F_TSO6 | NETIF_F_GSO_UDP_L4) |
190 | |
191 | int align; |
192 | int vnet_hdr_sz; |
193 | int sndbuf; |
194 | struct tap_filter txflt; |
195 | struct sock_fprog fprog; |
196 | /* protected by rtnl lock */ |
197 | bool filter_attached; |
198 | u32 msg_enable; |
199 | spinlock_t lock; |
200 | struct hlist_head flows[TUN_NUM_FLOW_ENTRIES]; |
201 | struct timer_list flow_gc_timer; |
202 | unsigned long ageing_time; |
203 | unsigned int numdisabled; |
204 | struct list_head disabled; |
205 | void *security; |
206 | u32 flow_count; |
207 | u32 rx_batched; |
208 | atomic_long_t rx_frame_errors; |
209 | struct bpf_prog __rcu *xdp_prog; |
210 | struct tun_prog __rcu *steering_prog; |
211 | struct tun_prog __rcu *filter_prog; |
212 | struct ethtool_link_ksettings link_ksettings; |
213 | /* init args */ |
214 | struct file *file; |
215 | struct ifreq *ifr; |
216 | }; |
217 | |
218 | struct veth { |
219 | __be16 h_vlan_proto; |
220 | __be16 h_vlan_TCI; |
221 | }; |
222 | |
223 | static void tun_flow_init(struct tun_struct *tun); |
224 | static void tun_flow_uninit(struct tun_struct *tun); |
225 | |
226 | static int tun_napi_receive(struct napi_struct *napi, int budget) |
227 | { |
228 | struct tun_file *tfile = container_of(napi, struct tun_file, napi); |
229 | struct sk_buff_head *queue = &tfile->sk.sk_write_queue; |
230 | struct sk_buff_head process_queue; |
231 | struct sk_buff *skb; |
232 | int received = 0; |
233 | |
234 | __skb_queue_head_init(list: &process_queue); |
235 | |
236 | spin_lock(lock: &queue->lock); |
237 | skb_queue_splice_tail_init(list: queue, head: &process_queue); |
238 | spin_unlock(lock: &queue->lock); |
239 | |
240 | while (received < budget && (skb = __skb_dequeue(list: &process_queue))) { |
241 | napi_gro_receive(napi, skb); |
242 | ++received; |
243 | } |
244 | |
245 | if (!skb_queue_empty(list: &process_queue)) { |
246 | spin_lock(lock: &queue->lock); |
247 | skb_queue_splice(list: &process_queue, head: queue); |
248 | spin_unlock(lock: &queue->lock); |
249 | } |
250 | |
251 | return received; |
252 | } |
253 | |
254 | static int tun_napi_poll(struct napi_struct *napi, int budget) |
255 | { |
256 | unsigned int received; |
257 | |
258 | received = tun_napi_receive(napi, budget); |
259 | |
260 | if (received < budget) |
261 | napi_complete_done(n: napi, work_done: received); |
262 | |
263 | return received; |
264 | } |
265 | |
266 | static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile, |
267 | bool napi_en, bool napi_frags) |
268 | { |
269 | tfile->napi_enabled = napi_en; |
270 | tfile->napi_frags_enabled = napi_en && napi_frags; |
271 | if (napi_en) { |
272 | netif_napi_add_tx(dev: tun->dev, napi: &tfile->napi, poll: tun_napi_poll); |
273 | napi_enable(n: &tfile->napi); |
274 | } |
275 | } |
276 | |
277 | static void tun_napi_enable(struct tun_file *tfile) |
278 | { |
279 | if (tfile->napi_enabled) |
280 | napi_enable(n: &tfile->napi); |
281 | } |
282 | |
283 | static void tun_napi_disable(struct tun_file *tfile) |
284 | { |
285 | if (tfile->napi_enabled) |
286 | napi_disable(n: &tfile->napi); |
287 | } |
288 | |
289 | static void tun_napi_del(struct tun_file *tfile) |
290 | { |
291 | if (tfile->napi_enabled) |
292 | netif_napi_del(napi: &tfile->napi); |
293 | } |
294 | |
295 | static bool tun_napi_frags_enabled(const struct tun_file *tfile) |
296 | { |
297 | return tfile->napi_frags_enabled; |
298 | } |
299 | |
300 | static inline u32 tun_hashfn(u32 rxhash) |
301 | { |
302 | return rxhash & TUN_MASK_FLOW_ENTRIES; |
303 | } |
304 | |
305 | static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash) |
306 | { |
307 | struct tun_flow_entry *e; |
308 | |
309 | hlist_for_each_entry_rcu(e, head, hash_link) { |
310 | if (e->rxhash == rxhash) |
311 | return e; |
312 | } |
313 | return NULL; |
314 | } |
315 | |
316 | static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun, |
317 | struct hlist_head *head, |
318 | u32 rxhash, u16 queue_index) |
319 | { |
320 | struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC); |
321 | |
322 | if (e) { |
323 | netif_info(tun, tx_queued, tun->dev, |
324 | "create flow: hash %u index %u\n", |
325 | rxhash, queue_index); |
326 | e->updated = jiffies; |
327 | e->rxhash = rxhash; |
328 | e->rps_rxhash = 0; |
329 | e->queue_index = queue_index; |
330 | e->tun = tun; |
331 | hlist_add_head_rcu(n: &e->hash_link, h: head); |
332 | ++tun->flow_count; |
333 | } |
334 | return e; |
335 | } |
336 | |
337 | static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e) |
338 | { |
339 | netif_info(tun, tx_queued, tun->dev, "delete flow: hash %u index %u\n", |
340 | e->rxhash, e->queue_index); |
341 | hlist_del_rcu(n: &e->hash_link); |
342 | kfree_rcu(e, rcu); |
343 | --tun->flow_count; |
344 | } |
345 | |
346 | static void tun_flow_flush(struct tun_struct *tun) |
347 | { |
348 | int i; |
349 | |
350 | spin_lock_bh(lock: &tun->lock); |
351 | for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) { |
352 | struct tun_flow_entry *e; |
353 | struct hlist_node *n; |
354 | |
355 | hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) |
356 | tun_flow_delete(tun, e); |
357 | } |
358 | spin_unlock_bh(lock: &tun->lock); |
359 | } |
360 | |
361 | static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index) |
362 | { |
363 | int i; |
364 | |
365 | spin_lock_bh(lock: &tun->lock); |
366 | for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) { |
367 | struct tun_flow_entry *e; |
368 | struct hlist_node *n; |
369 | |
370 | hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) { |
371 | if (e->queue_index == queue_index) |
372 | tun_flow_delete(tun, e); |
373 | } |
374 | } |
375 | spin_unlock_bh(lock: &tun->lock); |
376 | } |
377 | |
378 | static void tun_flow_cleanup(struct timer_list *t) |
379 | { |
380 | struct tun_struct *tun = timer_container_of(tun, t, flow_gc_timer); |
381 | unsigned long delay = tun->ageing_time; |
382 | unsigned long next_timer = jiffies + delay; |
383 | unsigned long count = 0; |
384 | int i; |
385 | |
386 | spin_lock(lock: &tun->lock); |
387 | for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) { |
388 | struct tun_flow_entry *e; |
389 | struct hlist_node *n; |
390 | |
391 | hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) { |
392 | unsigned long this_timer; |
393 | |
394 | this_timer = e->updated + delay; |
395 | if (time_before_eq(this_timer, jiffies)) { |
396 | tun_flow_delete(tun, e); |
397 | continue; |
398 | } |
399 | count++; |
400 | if (time_before(this_timer, next_timer)) |
401 | next_timer = this_timer; |
402 | } |
403 | } |
404 | |
405 | if (count) |
406 | mod_timer(timer: &tun->flow_gc_timer, expires: round_jiffies_up(j: next_timer)); |
407 | spin_unlock(lock: &tun->lock); |
408 | } |
409 | |
410 | static void tun_flow_update(struct tun_struct *tun, u32 rxhash, |
411 | struct tun_file *tfile) |
412 | { |
413 | struct hlist_head *head; |
414 | struct tun_flow_entry *e; |
415 | unsigned long delay = tun->ageing_time; |
416 | u16 queue_index = tfile->queue_index; |
417 | |
418 | head = &tun->flows[tun_hashfn(rxhash)]; |
419 | |
420 | rcu_read_lock(); |
421 | |
422 | e = tun_flow_find(head, rxhash); |
423 | if (likely(e)) { |
424 | /* TODO: keep queueing to old queue until it's empty? */ |
425 | if (READ_ONCE(e->queue_index) != queue_index) |
426 | WRITE_ONCE(e->queue_index, queue_index); |
427 | if (e->updated != jiffies) |
428 | e->updated = jiffies; |
429 | sock_rps_record_flow_hash(hash: e->rps_rxhash); |
430 | } else { |
431 | spin_lock_bh(lock: &tun->lock); |
432 | if (!tun_flow_find(head, rxhash) && |
433 | tun->flow_count < MAX_TAP_FLOWS) |
434 | tun_flow_create(tun, head, rxhash, queue_index); |
435 | |
436 | if (!timer_pending(timer: &tun->flow_gc_timer)) |
437 | mod_timer(timer: &tun->flow_gc_timer, |
438 | expires: round_jiffies_up(j: jiffies + delay)); |
439 | spin_unlock_bh(lock: &tun->lock); |
440 | } |
441 | |
442 | rcu_read_unlock(); |
443 | } |
444 | |
445 | /* Save the hash received in the stack receive path and update the |
446 | * flow_hash table accordingly. |
447 | */ |
448 | static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash) |
449 | { |
450 | if (unlikely(e->rps_rxhash != hash)) |
451 | e->rps_rxhash = hash; |
452 | } |
453 | |
454 | /* We try to identify a flow through its rxhash. The reason that |
455 | * we do not check rxq no. is because some cards(e.g 82599), chooses |
456 | * the rxq based on the txq where the last packet of the flow comes. As |
457 | * the userspace application move between processors, we may get a |
458 | * different rxq no. here. |
459 | */ |
460 | static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb) |
461 | { |
462 | struct tun_flow_entry *e; |
463 | u32 txq, numqueues; |
464 | |
465 | numqueues = READ_ONCE(tun->numqueues); |
466 | |
467 | txq = __skb_get_hash_symmetric(skb); |
468 | e = tun_flow_find(head: &tun->flows[tun_hashfn(rxhash: txq)], rxhash: txq); |
469 | if (e) { |
470 | tun_flow_save_rps_rxhash(e, hash: txq); |
471 | txq = e->queue_index; |
472 | } else { |
473 | txq = reciprocal_scale(val: txq, ep_ro: numqueues); |
474 | } |
475 | |
476 | return txq; |
477 | } |
478 | |
479 | static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb) |
480 | { |
481 | struct tun_prog *prog; |
482 | u32 numqueues; |
483 | u16 ret = 0; |
484 | |
485 | numqueues = READ_ONCE(tun->numqueues); |
486 | if (!numqueues) |
487 | return 0; |
488 | |
489 | prog = rcu_dereference(tun->steering_prog); |
490 | if (prog) |
491 | ret = bpf_prog_run_clear_cb(prog: prog->prog, skb); |
492 | |
493 | return ret % numqueues; |
494 | } |
495 | |
496 | static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb, |
497 | struct net_device *sb_dev) |
498 | { |
499 | struct tun_struct *tun = netdev_priv(dev); |
500 | u16 ret; |
501 | |
502 | rcu_read_lock(); |
503 | if (rcu_dereference(tun->steering_prog)) |
504 | ret = tun_ebpf_select_queue(tun, skb); |
505 | else |
506 | ret = tun_automq_select_queue(tun, skb); |
507 | rcu_read_unlock(); |
508 | |
509 | return ret; |
510 | } |
511 | |
512 | static inline bool tun_not_capable(struct tun_struct *tun) |
513 | { |
514 | const struct cred *cred = current_cred(); |
515 | struct net *net = dev_net(dev: tun->dev); |
516 | |
517 | return ((uid_valid(uid: tun->owner) && !uid_eq(left: cred->euid, right: tun->owner)) || |
518 | (gid_valid(gid: tun->group) && !in_egroup_p(tun->group))) && |
519 | !ns_capable(ns: net->user_ns, CAP_NET_ADMIN); |
520 | } |
521 | |
522 | static void tun_set_real_num_queues(struct tun_struct *tun) |
523 | { |
524 | netif_set_real_num_tx_queues(dev: tun->dev, txq: tun->numqueues); |
525 | netif_set_real_num_rx_queues(dev: tun->dev, rxq: tun->numqueues); |
526 | } |
527 | |
528 | static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile) |
529 | { |
530 | tfile->detached = tun; |
531 | list_add_tail(new: &tfile->next, head: &tun->disabled); |
532 | ++tun->numdisabled; |
533 | } |
534 | |
535 | static struct tun_struct *tun_enable_queue(struct tun_file *tfile) |
536 | { |
537 | struct tun_struct *tun = tfile->detached; |
538 | |
539 | tfile->detached = NULL; |
540 | list_del_init(entry: &tfile->next); |
541 | --tun->numdisabled; |
542 | return tun; |
543 | } |
544 | |
545 | void tun_ptr_free(void *ptr) |
546 | { |
547 | if (!ptr) |
548 | return; |
549 | if (tun_is_xdp_frame(ptr)) { |
550 | struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr); |
551 | |
552 | xdp_return_frame(xdpf); |
553 | } else { |
554 | __skb_array_destroy_skb(ptr); |
555 | } |
556 | } |
557 | EXPORT_SYMBOL_GPL(tun_ptr_free); |
558 | |
559 | static void tun_queue_purge(struct tun_file *tfile) |
560 | { |
561 | void *ptr; |
562 | |
563 | while ((ptr = ptr_ring_consume(r: &tfile->tx_ring)) != NULL) |
564 | tun_ptr_free(ptr); |
565 | |
566 | skb_queue_purge(list: &tfile->sk.sk_write_queue); |
567 | skb_queue_purge(list: &tfile->sk.sk_error_queue); |
568 | } |
569 | |
570 | static void __tun_detach(struct tun_file *tfile, bool clean) |
571 | { |
572 | struct tun_file *ntfile; |
573 | struct tun_struct *tun; |
574 | |
575 | tun = rtnl_dereference(tfile->tun); |
576 | |
577 | if (tun && clean) { |
578 | if (!tfile->detached) |
579 | tun_napi_disable(tfile); |
580 | tun_napi_del(tfile); |
581 | } |
582 | |
583 | if (tun && !tfile->detached) { |
584 | u16 index = tfile->queue_index; |
585 | BUG_ON(index >= tun->numqueues); |
586 | |
587 | rcu_assign_pointer(tun->tfiles[index], |
588 | tun->tfiles[tun->numqueues - 1]); |
589 | ntfile = rtnl_dereference(tun->tfiles[index]); |
590 | ntfile->queue_index = index; |
591 | ntfile->xdp_rxq.queue_index = index; |
592 | rcu_assign_pointer(tun->tfiles[tun->numqueues - 1], |
593 | NULL); |
594 | |
595 | --tun->numqueues; |
596 | if (clean) { |
597 | RCU_INIT_POINTER(tfile->tun, NULL); |
598 | sock_put(sk: &tfile->sk); |
599 | } else { |
600 | tun_disable_queue(tun, tfile); |
601 | tun_napi_disable(tfile); |
602 | } |
603 | |
604 | synchronize_net(); |
605 | tun_flow_delete_by_queue(tun, queue_index: tun->numqueues + 1); |
606 | /* Drop read queue */ |
607 | tun_queue_purge(tfile); |
608 | tun_set_real_num_queues(tun); |
609 | } else if (tfile->detached && clean) { |
610 | tun = tun_enable_queue(tfile); |
611 | sock_put(sk: &tfile->sk); |
612 | } |
613 | |
614 | if (clean) { |
615 | if (tun && tun->numqueues == 0 && tun->numdisabled == 0) { |
616 | netif_carrier_off(dev: tun->dev); |
617 | |
618 | if (!(tun->flags & IFF_PERSIST) && |
619 | tun->dev->reg_state == NETREG_REGISTERED) |
620 | unregister_netdevice(dev: tun->dev); |
621 | } |
622 | if (tun) |
623 | xdp_rxq_info_unreg(xdp_rxq: &tfile->xdp_rxq); |
624 | ptr_ring_cleanup(r: &tfile->tx_ring, destroy: tun_ptr_free); |
625 | } |
626 | } |
627 | |
628 | static void tun_detach(struct tun_file *tfile, bool clean) |
629 | { |
630 | struct tun_struct *tun; |
631 | struct net_device *dev; |
632 | |
633 | rtnl_lock(); |
634 | tun = rtnl_dereference(tfile->tun); |
635 | dev = tun ? tun->dev : NULL; |
636 | __tun_detach(tfile, clean); |
637 | if (dev) |
638 | netdev_state_change(dev); |
639 | rtnl_unlock(); |
640 | |
641 | if (clean) |
642 | sock_put(sk: &tfile->sk); |
643 | } |
644 | |
645 | static void tun_detach_all(struct net_device *dev) |
646 | { |
647 | struct tun_struct *tun = netdev_priv(dev); |
648 | struct tun_file *tfile, *tmp; |
649 | int i, n = tun->numqueues; |
650 | |
651 | for (i = 0; i < n; i++) { |
652 | tfile = rtnl_dereference(tun->tfiles[i]); |
653 | BUG_ON(!tfile); |
654 | tun_napi_disable(tfile); |
655 | tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN; |
656 | tfile->socket.sk->sk_data_ready(tfile->socket.sk); |
657 | RCU_INIT_POINTER(tfile->tun, NULL); |
658 | --tun->numqueues; |
659 | } |
660 | list_for_each_entry(tfile, &tun->disabled, next) { |
661 | tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN; |
662 | tfile->socket.sk->sk_data_ready(tfile->socket.sk); |
663 | RCU_INIT_POINTER(tfile->tun, NULL); |
664 | } |
665 | BUG_ON(tun->numqueues != 0); |
666 | |
667 | synchronize_net(); |
668 | for (i = 0; i < n; i++) { |
669 | tfile = rtnl_dereference(tun->tfiles[i]); |
670 | tun_napi_del(tfile); |
671 | /* Drop read queue */ |
672 | tun_queue_purge(tfile); |
673 | xdp_rxq_info_unreg(xdp_rxq: &tfile->xdp_rxq); |
674 | sock_put(sk: &tfile->sk); |
675 | } |
676 | list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) { |
677 | tun_napi_del(tfile); |
678 | tun_enable_queue(tfile); |
679 | tun_queue_purge(tfile); |
680 | xdp_rxq_info_unreg(xdp_rxq: &tfile->xdp_rxq); |
681 | sock_put(sk: &tfile->sk); |
682 | } |
683 | BUG_ON(tun->numdisabled != 0); |
684 | |
685 | if (tun->flags & IFF_PERSIST) |
686 | module_put(THIS_MODULE); |
687 | } |
688 | |
689 | static int tun_attach(struct tun_struct *tun, struct file *file, |
690 | bool skip_filter, bool napi, bool napi_frags, |
691 | bool publish_tun) |
692 | { |
693 | struct tun_file *tfile = file->private_data; |
694 | struct net_device *dev = tun->dev; |
695 | int err; |
696 | |
697 | err = security_tun_dev_attach(sk: tfile->socket.sk, security: tun->security); |
698 | if (err < 0) |
699 | goto out; |
700 | |
701 | err = -EINVAL; |
702 | if (rtnl_dereference(tfile->tun) && !tfile->detached) |
703 | goto out; |
704 | |
705 | err = -EBUSY; |
706 | if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1) |
707 | goto out; |
708 | |
709 | err = -E2BIG; |
710 | if (!tfile->detached && |
711 | tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES) |
712 | goto out; |
713 | |
714 | err = 0; |
715 | |
716 | /* Re-attach the filter to persist device */ |
717 | if (!skip_filter && (tun->filter_attached == true)) { |
718 | lock_sock(sk: tfile->socket.sk); |
719 | err = sk_attach_filter(fprog: &tun->fprog, sk: tfile->socket.sk); |
720 | release_sock(sk: tfile->socket.sk); |
721 | if (!err) |
722 | goto out; |
723 | } |
724 | |
725 | if (!tfile->detached && |
726 | ptr_ring_resize(&tfile->tx_ring, dev->tx_queue_len, |
727 | GFP_KERNEL, tun_ptr_free)) { |
728 | err = -ENOMEM; |
729 | goto out; |
730 | } |
731 | |
732 | tfile->queue_index = tun->numqueues; |
733 | tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN; |
734 | |
735 | if (tfile->detached) { |
736 | /* Re-attach detached tfile, updating XDP queue_index */ |
737 | WARN_ON(!xdp_rxq_info_is_reg(&tfile->xdp_rxq)); |
738 | |
739 | if (tfile->xdp_rxq.queue_index != tfile->queue_index) |
740 | tfile->xdp_rxq.queue_index = tfile->queue_index; |
741 | } else { |
742 | /* Setup XDP RX-queue info, for new tfile getting attached */ |
743 | err = xdp_rxq_info_reg(xdp_rxq: &tfile->xdp_rxq, |
744 | dev: tun->dev, queue_index: tfile->queue_index, napi_id: 0); |
745 | if (err < 0) |
746 | goto out; |
747 | err = xdp_rxq_info_reg_mem_model(xdp_rxq: &tfile->xdp_rxq, |
748 | type: MEM_TYPE_PAGE_SHARED, NULL); |
749 | if (err < 0) { |
750 | xdp_rxq_info_unreg(xdp_rxq: &tfile->xdp_rxq); |
751 | goto out; |
752 | } |
753 | err = 0; |
754 | } |
755 | |
756 | if (tfile->detached) { |
757 | tun_enable_queue(tfile); |
758 | tun_napi_enable(tfile); |
759 | } else { |
760 | sock_hold(sk: &tfile->sk); |
761 | tun_napi_init(tun, tfile, napi_en: napi, napi_frags); |
762 | } |
763 | |
764 | if (rtnl_dereference(tun->xdp_prog)) |
765 | sock_set_flag(sk: &tfile->sk, flag: SOCK_XDP); |
766 | |
767 | /* device is allowed to go away first, so no need to hold extra |
768 | * refcnt. |
769 | */ |
770 | |
771 | /* Publish tfile->tun and tun->tfiles only after we've fully |
772 | * initialized tfile; otherwise we risk using half-initialized |
773 | * object. |
774 | */ |
775 | if (publish_tun) |
776 | rcu_assign_pointer(tfile->tun, tun); |
777 | rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile); |
778 | tun->numqueues++; |
779 | tun_set_real_num_queues(tun); |
780 | out: |
781 | return err; |
782 | } |
783 | |
784 | static struct tun_struct *tun_get(struct tun_file *tfile) |
785 | { |
786 | struct tun_struct *tun; |
787 | |
788 | rcu_read_lock(); |
789 | tun = rcu_dereference(tfile->tun); |
790 | if (tun) |
791 | dev_hold(dev: tun->dev); |
792 | rcu_read_unlock(); |
793 | |
794 | return tun; |
795 | } |
796 | |
797 | static void tun_put(struct tun_struct *tun) |
798 | { |
799 | dev_put(dev: tun->dev); |
800 | } |
801 | |
802 | /* TAP filtering */ |
803 | static void addr_hash_set(u32 *mask, const u8 *addr) |
804 | { |
805 | int n = ether_crc(ETH_ALEN, addr) >> 26; |
806 | mask[n >> 5] |= (1 << (n & 31)); |
807 | } |
808 | |
809 | static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) |
810 | { |
811 | int n = ether_crc(ETH_ALEN, addr) >> 26; |
812 | return mask[n >> 5] & (1 << (n & 31)); |
813 | } |
814 | |
815 | static int update_filter(struct tap_filter *filter, void __user *arg) |
816 | { |
817 | struct { u8 u[ETH_ALEN]; } *addr; |
818 | struct tun_filter uf; |
819 | int err, alen, n, nexact; |
820 | |
821 | if (copy_from_user(to: &uf, from: arg, n: sizeof(uf))) |
822 | return -EFAULT; |
823 | |
824 | if (!uf.count) { |
825 | /* Disabled */ |
826 | filter->count = 0; |
827 | return 0; |
828 | } |
829 | |
830 | alen = ETH_ALEN * uf.count; |
831 | addr = memdup_user(arg + sizeof(uf), alen); |
832 | if (IS_ERR(ptr: addr)) |
833 | return PTR_ERR(ptr: addr); |
834 | |
835 | /* The filter is updated without holding any locks. Which is |
836 | * perfectly safe. We disable it first and in the worst |
837 | * case we'll accept a few undesired packets. */ |
838 | filter->count = 0; |
839 | wmb(); |
840 | |
841 | /* Use first set of addresses as an exact filter */ |
842 | for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) |
843 | memcpy(filter->addr[n], addr[n].u, ETH_ALEN); |
844 | |
845 | nexact = n; |
846 | |
847 | /* Remaining multicast addresses are hashed, |
848 | * unicast will leave the filter disabled. */ |
849 | memset(filter->mask, 0, sizeof(filter->mask)); |
850 | for (; n < uf.count; n++) { |
851 | if (!is_multicast_ether_addr(addr: addr[n].u)) { |
852 | err = 0; /* no filter */ |
853 | goto free_addr; |
854 | } |
855 | addr_hash_set(mask: filter->mask, addr: addr[n].u); |
856 | } |
857 | |
858 | /* For ALLMULTI just set the mask to all ones. |
859 | * This overrides the mask populated above. */ |
860 | if ((uf.flags & TUN_FLT_ALLMULTI)) |
861 | memset(filter->mask, ~0, sizeof(filter->mask)); |
862 | |
863 | /* Now enable the filter */ |
864 | wmb(); |
865 | filter->count = nexact; |
866 | |
867 | /* Return the number of exact filters */ |
868 | err = nexact; |
869 | free_addr: |
870 | kfree(objp: addr); |
871 | return err; |
872 | } |
873 | |
874 | /* Returns: 0 - drop, !=0 - accept */ |
875 | static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) |
876 | { |
877 | /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect |
878 | * at this point. */ |
879 | struct ethhdr *eh = (struct ethhdr *) skb->data; |
880 | int i; |
881 | |
882 | /* Exact match */ |
883 | for (i = 0; i < filter->count; i++) |
884 | if (ether_addr_equal(addr1: eh->h_dest, addr2: filter->addr[i])) |
885 | return 1; |
886 | |
887 | /* Inexact match (multicast only) */ |
888 | if (is_multicast_ether_addr(addr: eh->h_dest)) |
889 | return addr_hash_test(mask: filter->mask, addr: eh->h_dest); |
890 | |
891 | return 0; |
892 | } |
893 | |
894 | /* |
895 | * Checks whether the packet is accepted or not. |
896 | * Returns: 0 - drop, !=0 - accept |
897 | */ |
898 | static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) |
899 | { |
900 | if (!filter->count) |
901 | return 1; |
902 | |
903 | return run_filter(filter, skb); |
904 | } |
905 | |
906 | /* Network device part of the driver */ |
907 | |
908 | static const struct ethtool_ops tun_ethtool_ops; |
909 | |
910 | static int tun_net_init(struct net_device *dev) |
911 | { |
912 | struct tun_struct *tun = netdev_priv(dev); |
913 | struct ifreq *ifr = tun->ifr; |
914 | int err; |
915 | |
916 | spin_lock_init(&tun->lock); |
917 | |
918 | err = security_tun_dev_alloc_security(security: &tun->security); |
919 | if (err < 0) |
920 | return err; |
921 | |
922 | tun_flow_init(tun); |
923 | |
924 | dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; |
925 | dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | |
926 | TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | |
927 | NETIF_F_HW_VLAN_STAG_TX; |
928 | dev->features = dev->hw_features; |
929 | dev->vlan_features = dev->features & |
930 | ~(NETIF_F_HW_VLAN_CTAG_TX | |
931 | NETIF_F_HW_VLAN_STAG_TX); |
932 | dev->lltx = true; |
933 | |
934 | tun->flags = (tun->flags & ~TUN_FEATURES) | |
935 | (ifr->ifr_flags & TUN_FEATURES); |
936 | |
937 | INIT_LIST_HEAD(list: &tun->disabled); |
938 | err = tun_attach(tun, file: tun->file, skip_filter: false, napi: ifr->ifr_flags & IFF_NAPI, |
939 | napi_frags: ifr->ifr_flags & IFF_NAPI_FRAGS, publish_tun: false); |
940 | if (err < 0) { |
941 | tun_flow_uninit(tun); |
942 | security_tun_dev_free_security(security: tun->security); |
943 | return err; |
944 | } |
945 | return 0; |
946 | } |
947 | |
948 | /* Net device detach from fd. */ |
949 | static void tun_net_uninit(struct net_device *dev) |
950 | { |
951 | tun_detach_all(dev); |
952 | } |
953 | |
954 | /* Net device open. */ |
955 | static int tun_net_open(struct net_device *dev) |
956 | { |
957 | netif_tx_start_all_queues(dev); |
958 | |
959 | return 0; |
960 | } |
961 | |
962 | /* Net device close. */ |
963 | static int tun_net_close(struct net_device *dev) |
964 | { |
965 | netif_tx_stop_all_queues(dev); |
966 | return 0; |
967 | } |
968 | |
969 | /* Net device start xmit */ |
970 | static void tun_automq_xmit(struct tun_struct *tun, struct sk_buff *skb) |
971 | { |
972 | #ifdef CONFIG_RPS |
973 | if (tun->numqueues == 1 && static_branch_unlikely(&rps_needed)) { |
974 | /* Select queue was not called for the skbuff, so we extract the |
975 | * RPS hash and save it into the flow_table here. |
976 | */ |
977 | struct tun_flow_entry *e; |
978 | __u32 rxhash; |
979 | |
980 | rxhash = __skb_get_hash_symmetric(skb); |
981 | e = tun_flow_find(head: &tun->flows[tun_hashfn(rxhash)], rxhash); |
982 | if (e) |
983 | tun_flow_save_rps_rxhash(e, hash: rxhash); |
984 | } |
985 | #endif |
986 | } |
987 | |
988 | static unsigned int run_ebpf_filter(struct tun_struct *tun, |
989 | struct sk_buff *skb, |
990 | int len) |
991 | { |
992 | struct tun_prog *prog = rcu_dereference(tun->filter_prog); |
993 | |
994 | if (prog) |
995 | len = bpf_prog_run_clear_cb(prog: prog->prog, skb); |
996 | |
997 | return len; |
998 | } |
999 | |
1000 | /* Net device start xmit */ |
1001 | static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) |
1002 | { |
1003 | struct tun_struct *tun = netdev_priv(dev); |
1004 | enum skb_drop_reason drop_reason; |
1005 | int txq = skb->queue_mapping; |
1006 | struct netdev_queue *queue; |
1007 | struct tun_file *tfile; |
1008 | int len = skb->len; |
1009 | |
1010 | rcu_read_lock(); |
1011 | tfile = rcu_dereference(tun->tfiles[txq]); |
1012 | |
1013 | /* Drop packet if interface is not attached */ |
1014 | if (!tfile) { |
1015 | drop_reason = SKB_DROP_REASON_DEV_READY; |
1016 | goto drop; |
1017 | } |
1018 | |
1019 | if (!rcu_dereference(tun->steering_prog)) |
1020 | tun_automq_xmit(tun, skb); |
1021 | |
1022 | netif_info(tun, tx_queued, tun->dev, "%s %d\n", __func__, skb->len); |
1023 | |
1024 | /* Drop if the filter does not like it. |
1025 | * This is a noop if the filter is disabled. |
1026 | * Filter can be enabled only for the TAP devices. */ |
1027 | if (!check_filter(filter: &tun->txflt, skb)) { |
1028 | drop_reason = SKB_DROP_REASON_TAP_TXFILTER; |
1029 | goto drop; |
1030 | } |
1031 | |
1032 | if (tfile->socket.sk->sk_filter && |
1033 | sk_filter(sk: tfile->socket.sk, skb)) { |
1034 | drop_reason = SKB_DROP_REASON_SOCKET_FILTER; |
1035 | goto drop; |
1036 | } |
1037 | |
1038 | len = run_ebpf_filter(tun, skb, len); |
1039 | if (len == 0) { |
1040 | drop_reason = SKB_DROP_REASON_TAP_FILTER; |
1041 | goto drop; |
1042 | } |
1043 | |
1044 | if (pskb_trim(skb, len)) { |
1045 | drop_reason = SKB_DROP_REASON_NOMEM; |
1046 | goto drop; |
1047 | } |
1048 | |
1049 | if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC))) { |
1050 | drop_reason = SKB_DROP_REASON_SKB_UCOPY_FAULT; |
1051 | goto drop; |
1052 | } |
1053 | |
1054 | skb_tx_timestamp(skb); |
1055 | |
1056 | /* Orphan the skb - required as we might hang on to it |
1057 | * for indefinite time. |
1058 | */ |
1059 | skb_orphan(skb); |
1060 | |
1061 | nf_reset_ct(skb); |
1062 | |
1063 | if (ptr_ring_produce(r: &tfile->tx_ring, ptr: skb)) { |
1064 | drop_reason = SKB_DROP_REASON_FULL_RING; |
1065 | goto drop; |
1066 | } |
1067 | |
1068 | /* dev->lltx requires to do our own update of trans_start */ |
1069 | queue = netdev_get_tx_queue(dev, index: txq); |
1070 | txq_trans_cond_update(txq: queue); |
1071 | |
1072 | /* Notify and wake up reader process */ |
1073 | if (tfile->flags & TUN_FASYNC) |
1074 | kill_fasync(&tfile->fasync, SIGIO, POLL_IN); |
1075 | tfile->socket.sk->sk_data_ready(tfile->socket.sk); |
1076 | |
1077 | rcu_read_unlock(); |
1078 | return NETDEV_TX_OK; |
1079 | |
1080 | drop: |
1081 | dev_core_stats_tx_dropped_inc(dev); |
1082 | skb_tx_error(skb); |
1083 | kfree_skb_reason(skb, reason: drop_reason); |
1084 | rcu_read_unlock(); |
1085 | return NET_XMIT_DROP; |
1086 | } |
1087 | |
1088 | static void tun_net_mclist(struct net_device *dev) |
1089 | { |
1090 | /* |
1091 | * This callback is supposed to deal with mc filter in |
1092 | * _rx_ path and has nothing to do with the _tx_ path. |
1093 | * In rx path we always accept everything userspace gives us. |
1094 | */ |
1095 | } |
1096 | |
1097 | static netdev_features_t tun_net_fix_features(struct net_device *dev, |
1098 | netdev_features_t features) |
1099 | { |
1100 | struct tun_struct *tun = netdev_priv(dev); |
1101 | |
1102 | return (features & tun->set_features) | (features & ~TUN_USER_FEATURES); |
1103 | } |
1104 | |
1105 | static void tun_set_headroom(struct net_device *dev, int new_hr) |
1106 | { |
1107 | struct tun_struct *tun = netdev_priv(dev); |
1108 | |
1109 | if (new_hr < NET_SKB_PAD) |
1110 | new_hr = NET_SKB_PAD; |
1111 | |
1112 | tun->align = new_hr; |
1113 | } |
1114 | |
1115 | static void |
1116 | tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) |
1117 | { |
1118 | struct tun_struct *tun = netdev_priv(dev); |
1119 | |
1120 | dev_get_tstats64(dev, s: stats); |
1121 | |
1122 | stats->rx_frame_errors += |
1123 | (unsigned long)atomic_long_read(v: &tun->rx_frame_errors); |
1124 | } |
1125 | |
1126 | static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog, |
1127 | struct netlink_ext_ack *extack) |
1128 | { |
1129 | struct tun_struct *tun = netdev_priv(dev); |
1130 | struct tun_file *tfile; |
1131 | struct bpf_prog *old_prog; |
1132 | int i; |
1133 | |
1134 | old_prog = rtnl_dereference(tun->xdp_prog); |
1135 | rcu_assign_pointer(tun->xdp_prog, prog); |
1136 | if (old_prog) |
1137 | bpf_prog_put(prog: old_prog); |
1138 | |
1139 | for (i = 0; i < tun->numqueues; i++) { |
1140 | tfile = rtnl_dereference(tun->tfiles[i]); |
1141 | if (prog) |
1142 | sock_set_flag(sk: &tfile->sk, flag: SOCK_XDP); |
1143 | else |
1144 | sock_reset_flag(sk: &tfile->sk, flag: SOCK_XDP); |
1145 | } |
1146 | list_for_each_entry(tfile, &tun->disabled, next) { |
1147 | if (prog) |
1148 | sock_set_flag(sk: &tfile->sk, flag: SOCK_XDP); |
1149 | else |
1150 | sock_reset_flag(sk: &tfile->sk, flag: SOCK_XDP); |
1151 | } |
1152 | |
1153 | return 0; |
1154 | } |
1155 | |
1156 | static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp) |
1157 | { |
1158 | switch (xdp->command) { |
1159 | case XDP_SETUP_PROG: |
1160 | return tun_xdp_set(dev, prog: xdp->prog, extack: xdp->extack); |
1161 | default: |
1162 | return -EINVAL; |
1163 | } |
1164 | } |
1165 | |
1166 | static int tun_net_change_carrier(struct net_device *dev, bool new_carrier) |
1167 | { |
1168 | if (new_carrier) { |
1169 | struct tun_struct *tun = netdev_priv(dev); |
1170 | |
1171 | if (!tun->numqueues) |
1172 | return -EPERM; |
1173 | |
1174 | netif_carrier_on(dev); |
1175 | } else { |
1176 | netif_carrier_off(dev); |
1177 | } |
1178 | return 0; |
1179 | } |
1180 | |
1181 | static const struct net_device_ops tun_netdev_ops = { |
1182 | .ndo_init = tun_net_init, |
1183 | .ndo_uninit = tun_net_uninit, |
1184 | .ndo_open = tun_net_open, |
1185 | .ndo_stop = tun_net_close, |
1186 | .ndo_start_xmit = tun_net_xmit, |
1187 | .ndo_fix_features = tun_net_fix_features, |
1188 | .ndo_select_queue = tun_select_queue, |
1189 | .ndo_set_rx_headroom = tun_set_headroom, |
1190 | .ndo_get_stats64 = tun_net_get_stats64, |
1191 | .ndo_change_carrier = tun_net_change_carrier, |
1192 | }; |
1193 | |
1194 | static void __tun_xdp_flush_tfile(struct tun_file *tfile) |
1195 | { |
1196 | /* Notify and wake up reader process */ |
1197 | if (tfile->flags & TUN_FASYNC) |
1198 | kill_fasync(&tfile->fasync, SIGIO, POLL_IN); |
1199 | tfile->socket.sk->sk_data_ready(tfile->socket.sk); |
1200 | } |
1201 | |
1202 | static int tun_xdp_xmit(struct net_device *dev, int n, |
1203 | struct xdp_frame **frames, u32 flags) |
1204 | { |
1205 | struct tun_struct *tun = netdev_priv(dev); |
1206 | struct tun_file *tfile; |
1207 | u32 numqueues; |
1208 | int nxmit = 0; |
1209 | int i; |
1210 | |
1211 | if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) |
1212 | return -EINVAL; |
1213 | |
1214 | rcu_read_lock(); |
1215 | |
1216 | resample: |
1217 | numqueues = READ_ONCE(tun->numqueues); |
1218 | if (!numqueues) { |
1219 | rcu_read_unlock(); |
1220 | return -ENXIO; /* Caller will free/return all frames */ |
1221 | } |
1222 | |
1223 | tfile = rcu_dereference(tun->tfiles[smp_processor_id() % |
1224 | numqueues]); |
1225 | if (unlikely(!tfile)) |
1226 | goto resample; |
1227 | |
1228 | spin_lock(lock: &tfile->tx_ring.producer_lock); |
1229 | for (i = 0; i < n; i++) { |
1230 | struct xdp_frame *xdp = frames[i]; |
1231 | /* Encode the XDP flag into lowest bit for consumer to differ |
1232 | * XDP buffer from sk_buff. |
1233 | */ |
1234 | void *frame = tun_xdp_to_ptr(xdp); |
1235 | |
1236 | if (__ptr_ring_produce(r: &tfile->tx_ring, ptr: frame)) { |
1237 | dev_core_stats_tx_dropped_inc(dev); |
1238 | break; |
1239 | } |
1240 | nxmit++; |
1241 | } |
1242 | spin_unlock(lock: &tfile->tx_ring.producer_lock); |
1243 | |
1244 | if (flags & XDP_XMIT_FLUSH) |
1245 | __tun_xdp_flush_tfile(tfile); |
1246 | |
1247 | rcu_read_unlock(); |
1248 | return nxmit; |
1249 | } |
1250 | |
1251 | static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp) |
1252 | { |
1253 | struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp); |
1254 | int nxmit; |
1255 | |
1256 | if (unlikely(!frame)) |
1257 | return -EOVERFLOW; |
1258 | |
1259 | nxmit = tun_xdp_xmit(dev, n: 1, frames: &frame, XDP_XMIT_FLUSH); |
1260 | if (!nxmit) |
1261 | xdp_return_frame_rx_napi(xdpf: frame); |
1262 | return nxmit; |
1263 | } |
1264 | |
1265 | static const struct net_device_ops tap_netdev_ops = { |
1266 | .ndo_init = tun_net_init, |
1267 | .ndo_uninit = tun_net_uninit, |
1268 | .ndo_open = tun_net_open, |
1269 | .ndo_stop = tun_net_close, |
1270 | .ndo_start_xmit = tun_net_xmit, |
1271 | .ndo_fix_features = tun_net_fix_features, |
1272 | .ndo_set_rx_mode = tun_net_mclist, |
1273 | .ndo_set_mac_address = eth_mac_addr, |
1274 | .ndo_validate_addr = eth_validate_addr, |
1275 | .ndo_select_queue = tun_select_queue, |
1276 | .ndo_features_check = passthru_features_check, |
1277 | .ndo_set_rx_headroom = tun_set_headroom, |
1278 | .ndo_bpf = tun_xdp, |
1279 | .ndo_xdp_xmit = tun_xdp_xmit, |
1280 | .ndo_change_carrier = tun_net_change_carrier, |
1281 | }; |
1282 | |
1283 | static void tun_flow_init(struct tun_struct *tun) |
1284 | { |
1285 | int i; |
1286 | |
1287 | for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) |
1288 | INIT_HLIST_HEAD(&tun->flows[i]); |
1289 | |
1290 | tun->ageing_time = TUN_FLOW_EXPIRE; |
1291 | timer_setup(&tun->flow_gc_timer, tun_flow_cleanup, 0); |
1292 | mod_timer(timer: &tun->flow_gc_timer, |
1293 | expires: round_jiffies_up(j: jiffies + tun->ageing_time)); |
1294 | } |
1295 | |
1296 | static void tun_flow_uninit(struct tun_struct *tun) |
1297 | { |
1298 | timer_delete_sync(timer: &tun->flow_gc_timer); |
1299 | tun_flow_flush(tun); |
1300 | } |
1301 | |
1302 | #define MIN_MTU 68 |
1303 | #define MAX_MTU 65535 |
1304 | |
1305 | /* Initialize net device. */ |
1306 | static void tun_net_initialize(struct net_device *dev) |
1307 | { |
1308 | struct tun_struct *tun = netdev_priv(dev); |
1309 | |
1310 | switch (tun->flags & TUN_TYPE_MASK) { |
1311 | case IFF_TUN: |
1312 | dev->netdev_ops = &tun_netdev_ops; |
1313 | dev->header_ops = &ip_tunnel_header_ops; |
1314 | |
1315 | /* Point-to-Point TUN Device */ |
1316 | dev->hard_header_len = 0; |
1317 | dev->addr_len = 0; |
1318 | dev->mtu = 1500; |
1319 | |
1320 | /* Zero header length */ |
1321 | dev->type = ARPHRD_NONE; |
1322 | dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; |
1323 | break; |
1324 | |
1325 | case IFF_TAP: |
1326 | dev->netdev_ops = &tap_netdev_ops; |
1327 | /* Ethernet TAP Device */ |
1328 | ether_setup(dev); |
1329 | dev->priv_flags &= ~IFF_TX_SKB_SHARING; |
1330 | dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; |
1331 | |
1332 | eth_hw_addr_random(dev); |
1333 | |
1334 | /* Currently tun does not support XDP, only tap does. */ |
1335 | dev->xdp_features = NETDEV_XDP_ACT_BASIC | |
1336 | NETDEV_XDP_ACT_REDIRECT | |
1337 | NETDEV_XDP_ACT_NDO_XMIT; |
1338 | |
1339 | break; |
1340 | } |
1341 | |
1342 | dev->min_mtu = MIN_MTU; |
1343 | dev->max_mtu = MAX_MTU - dev->hard_header_len; |
1344 | } |
1345 | |
1346 | static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile) |
1347 | { |
1348 | struct sock *sk = tfile->socket.sk; |
1349 | |
1350 | return (tun->dev->flags & IFF_UP) && sock_writeable(sk); |
1351 | } |
1352 | |
1353 | /* Character device part */ |
1354 | |
1355 | /* Poll */ |
1356 | static __poll_t tun_chr_poll(struct file *file, poll_table *wait) |
1357 | { |
1358 | struct tun_file *tfile = file->private_data; |
1359 | struct tun_struct *tun = tun_get(tfile); |
1360 | struct sock *sk; |
1361 | __poll_t mask = 0; |
1362 | |
1363 | if (!tun) |
1364 | return EPOLLERR; |
1365 | |
1366 | sk = tfile->socket.sk; |
1367 | |
1368 | poll_wait(filp: file, wait_address: sk_sleep(sk), p: wait); |
1369 | |
1370 | if (!ptr_ring_empty(r: &tfile->tx_ring)) |
1371 | mask |= EPOLLIN | EPOLLRDNORM; |
1372 | |
1373 | /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to |
1374 | * guarantee EPOLLOUT to be raised by either here or |
1375 | * tun_sock_write_space(). Then process could get notification |
1376 | * after it writes to a down device and meets -EIO. |
1377 | */ |
1378 | if (tun_sock_writeable(tun, tfile) || |
1379 | (!test_and_set_bit(nr: SOCKWQ_ASYNC_NOSPACE, addr: &sk->sk_socket->flags) && |
1380 | tun_sock_writeable(tun, tfile))) |
1381 | mask |= EPOLLOUT | EPOLLWRNORM; |
1382 | |
1383 | if (tun->dev->reg_state != NETREG_REGISTERED) |
1384 | mask = EPOLLERR; |
1385 | |
1386 | tun_put(tun); |
1387 | return mask; |
1388 | } |
1389 | |
1390 | static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile, |
1391 | size_t len, |
1392 | const struct iov_iter *it) |
1393 | { |
1394 | struct sk_buff *skb; |
1395 | size_t linear; |
1396 | int err; |
1397 | int i; |
1398 | |
1399 | if (it->nr_segs > MAX_SKB_FRAGS + 1 || |
1400 | len > (ETH_MAX_MTU - NET_SKB_PAD - NET_IP_ALIGN)) |
1401 | return ERR_PTR(error: -EMSGSIZE); |
1402 | |
1403 | local_bh_disable(); |
1404 | skb = napi_get_frags(napi: &tfile->napi); |
1405 | local_bh_enable(); |
1406 | if (!skb) |
1407 | return ERR_PTR(error: -ENOMEM); |
1408 | |
1409 | linear = iov_iter_single_seg_count(i: it); |
1410 | err = __skb_grow(skb, len: linear); |
1411 | if (err) |
1412 | goto free; |
1413 | |
1414 | skb->len = len; |
1415 | skb->data_len = len - linear; |
1416 | skb->truesize += skb->data_len; |
1417 | |
1418 | for (i = 1; i < it->nr_segs; i++) { |
1419 | const struct iovec *iov = iter_iov(iter: it) + i; |
1420 | size_t fragsz = iov->iov_len; |
1421 | struct page *page; |
1422 | void *frag; |
1423 | |
1424 | if (fragsz == 0 || fragsz > PAGE_SIZE) { |
1425 | err = -EINVAL; |
1426 | goto free; |
1427 | } |
1428 | frag = netdev_alloc_frag(fragsz); |
1429 | if (!frag) { |
1430 | err = -ENOMEM; |
1431 | goto free; |
1432 | } |
1433 | page = virt_to_head_page(x: frag); |
1434 | skb_fill_page_desc(skb, i: i - 1, page, |
1435 | off: frag - page_address(page), size: fragsz); |
1436 | } |
1437 | |
1438 | return skb; |
1439 | free: |
1440 | /* frees skb and all frags allocated with napi_alloc_frag() */ |
1441 | napi_free_frags(napi: &tfile->napi); |
1442 | return ERR_PTR(error: err); |
1443 | } |
1444 | |
1445 | /* prepad is the amount to reserve at front. len is length after that. |
1446 | * linear is a hint as to how much to copy (usually headers). */ |
1447 | static struct sk_buff *tun_alloc_skb(struct tun_file *tfile, |
1448 | size_t prepad, size_t len, |
1449 | size_t linear, int noblock) |
1450 | { |
1451 | struct sock *sk = tfile->socket.sk; |
1452 | struct sk_buff *skb; |
1453 | int err; |
1454 | |
1455 | /* Under a page? Don't bother with paged skb. */ |
1456 | if (prepad + len < PAGE_SIZE) |
1457 | linear = len; |
1458 | |
1459 | if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) |
1460 | linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); |
1461 | skb = sock_alloc_send_pskb(sk, header_len: prepad + linear, data_len: len - linear, noblock, |
1462 | errcode: &err, PAGE_ALLOC_COSTLY_ORDER); |
1463 | if (!skb) |
1464 | return ERR_PTR(error: err); |
1465 | |
1466 | skb_reserve(skb, len: prepad); |
1467 | skb_put(skb, len: linear); |
1468 | skb->data_len = len - linear; |
1469 | skb->len += len - linear; |
1470 | |
1471 | return skb; |
1472 | } |
1473 | |
1474 | static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile, |
1475 | struct sk_buff *skb, int more) |
1476 | { |
1477 | struct sk_buff_head *queue = &tfile->sk.sk_write_queue; |
1478 | struct sk_buff_head process_queue; |
1479 | u32 rx_batched = tun->rx_batched; |
1480 | bool rcv = false; |
1481 | |
1482 | if (!rx_batched || (!more && skb_queue_empty(list: queue))) { |
1483 | local_bh_disable(); |
1484 | skb_record_rx_queue(skb, rx_queue: tfile->queue_index); |
1485 | netif_receive_skb(skb); |
1486 | local_bh_enable(); |
1487 | return; |
1488 | } |
1489 | |
1490 | spin_lock(lock: &queue->lock); |
1491 | if (!more || skb_queue_len(list_: queue) == rx_batched) { |
1492 | __skb_queue_head_init(list: &process_queue); |
1493 | skb_queue_splice_tail_init(list: queue, head: &process_queue); |
1494 | rcv = true; |
1495 | } else { |
1496 | __skb_queue_tail(list: queue, newsk: skb); |
1497 | } |
1498 | spin_unlock(lock: &queue->lock); |
1499 | |
1500 | if (rcv) { |
1501 | struct sk_buff *nskb; |
1502 | |
1503 | local_bh_disable(); |
1504 | while ((nskb = __skb_dequeue(list: &process_queue))) { |
1505 | skb_record_rx_queue(skb: nskb, rx_queue: tfile->queue_index); |
1506 | netif_receive_skb(skb: nskb); |
1507 | } |
1508 | skb_record_rx_queue(skb, rx_queue: tfile->queue_index); |
1509 | netif_receive_skb(skb); |
1510 | local_bh_enable(); |
1511 | } |
1512 | } |
1513 | |
1514 | static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile, |
1515 | int len, int noblock, bool zerocopy) |
1516 | { |
1517 | if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) |
1518 | return false; |
1519 | |
1520 | if (tfile->socket.sk->sk_sndbuf != INT_MAX) |
1521 | return false; |
1522 | |
1523 | if (!noblock) |
1524 | return false; |
1525 | |
1526 | if (zerocopy) |
1527 | return false; |
1528 | |
1529 | if (SKB_DATA_ALIGN(len + TUN_RX_PAD + XDP_PACKET_HEADROOM) + |
1530 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE) |
1531 | return false; |
1532 | |
1533 | return true; |
1534 | } |
1535 | |
1536 | static struct sk_buff *__tun_build_skb(struct tun_file *tfile, |
1537 | struct page_frag *alloc_frag, char *buf, |
1538 | int buflen, int len, int pad, |
1539 | int metasize) |
1540 | { |
1541 | struct sk_buff *skb = build_skb(data: buf, frag_size: buflen); |
1542 | |
1543 | if (!skb) |
1544 | return ERR_PTR(error: -ENOMEM); |
1545 | |
1546 | skb_reserve(skb, len: pad); |
1547 | skb_put(skb, len); |
1548 | if (metasize) |
1549 | skb_metadata_set(skb, meta_len: metasize); |
1550 | skb_set_owner_w(skb, sk: tfile->socket.sk); |
1551 | |
1552 | get_page(page: alloc_frag->page); |
1553 | alloc_frag->offset += buflen; |
1554 | |
1555 | return skb; |
1556 | } |
1557 | |
1558 | static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog, |
1559 | struct xdp_buff *xdp, u32 act) |
1560 | { |
1561 | int err; |
1562 | |
1563 | switch (act) { |
1564 | case XDP_REDIRECT: |
1565 | err = xdp_do_redirect(dev: tun->dev, xdp, prog: xdp_prog); |
1566 | if (err) { |
1567 | dev_core_stats_rx_dropped_inc(dev: tun->dev); |
1568 | return err; |
1569 | } |
1570 | dev_sw_netstats_rx_add(dev: tun->dev, len: xdp->data_end - xdp->data); |
1571 | break; |
1572 | case XDP_TX: |
1573 | err = tun_xdp_tx(dev: tun->dev, xdp); |
1574 | if (err < 0) { |
1575 | dev_core_stats_rx_dropped_inc(dev: tun->dev); |
1576 | return err; |
1577 | } |
1578 | dev_sw_netstats_rx_add(dev: tun->dev, len: xdp->data_end - xdp->data); |
1579 | break; |
1580 | case XDP_PASS: |
1581 | break; |
1582 | default: |
1583 | bpf_warn_invalid_xdp_action(dev: tun->dev, prog: xdp_prog, act); |
1584 | fallthrough; |
1585 | case XDP_ABORTED: |
1586 | trace_xdp_exception(dev: tun->dev, xdp: xdp_prog, act); |
1587 | fallthrough; |
1588 | case XDP_DROP: |
1589 | dev_core_stats_rx_dropped_inc(dev: tun->dev); |
1590 | break; |
1591 | } |
1592 | |
1593 | return act; |
1594 | } |
1595 | |
1596 | static struct sk_buff *tun_build_skb(struct tun_struct *tun, |
1597 | struct tun_file *tfile, |
1598 | struct iov_iter *from, |
1599 | struct virtio_net_hdr *hdr, |
1600 | int len, int *skb_xdp) |
1601 | { |
1602 | struct page_frag *alloc_frag = ¤t->task_frag; |
1603 | struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx; |
1604 | struct bpf_prog *xdp_prog; |
1605 | int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); |
1606 | char *buf; |
1607 | size_t copied; |
1608 | int pad = TUN_RX_PAD; |
1609 | int metasize = 0; |
1610 | int err = 0; |
1611 | |
1612 | rcu_read_lock(); |
1613 | xdp_prog = rcu_dereference(tun->xdp_prog); |
1614 | if (xdp_prog) |
1615 | pad += XDP_PACKET_HEADROOM; |
1616 | buflen += SKB_DATA_ALIGN(len + pad); |
1617 | rcu_read_unlock(); |
1618 | |
1619 | alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES); |
1620 | if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL))) |
1621 | return ERR_PTR(error: -ENOMEM); |
1622 | |
1623 | buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset; |
1624 | copied = copy_page_from_iter(page: alloc_frag->page, |
1625 | offset: alloc_frag->offset + pad, |
1626 | bytes: len, i: from); |
1627 | if (copied != len) |
1628 | return ERR_PTR(error: -EFAULT); |
1629 | |
1630 | /* There's a small window that XDP may be set after the check |
1631 | * of xdp_prog above, this should be rare and for simplicity |
1632 | * we do XDP on skb in case the headroom is not enough. |
1633 | */ |
1634 | if (hdr->gso_type || !xdp_prog) { |
1635 | *skb_xdp = 1; |
1636 | return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, |
1637 | pad, metasize); |
1638 | } |
1639 | |
1640 | *skb_xdp = 0; |
1641 | |
1642 | local_bh_disable(); |
1643 | rcu_read_lock(); |
1644 | bpf_net_ctx = bpf_net_ctx_set(bpf_net_ctx: &__bpf_net_ctx); |
1645 | xdp_prog = rcu_dereference(tun->xdp_prog); |
1646 | if (xdp_prog) { |
1647 | struct xdp_buff xdp; |
1648 | u32 act; |
1649 | |
1650 | xdp_init_buff(xdp: &xdp, frame_sz: buflen, rxq: &tfile->xdp_rxq); |
1651 | xdp_prepare_buff(xdp: &xdp, hard_start: buf, headroom: pad, data_len: len, meta_valid: true); |
1652 | |
1653 | act = bpf_prog_run_xdp(prog: xdp_prog, xdp: &xdp); |
1654 | if (act == XDP_REDIRECT || act == XDP_TX) { |
1655 | get_page(page: alloc_frag->page); |
1656 | alloc_frag->offset += buflen; |
1657 | } |
1658 | err = tun_xdp_act(tun, xdp_prog, xdp: &xdp, act); |
1659 | if (err < 0) { |
1660 | if (act == XDP_REDIRECT || act == XDP_TX) |
1661 | put_page(page: alloc_frag->page); |
1662 | goto out; |
1663 | } |
1664 | |
1665 | if (err == XDP_REDIRECT) |
1666 | xdp_do_flush(); |
1667 | if (err != XDP_PASS) |
1668 | goto out; |
1669 | |
1670 | pad = xdp.data - xdp.data_hard_start; |
1671 | len = xdp.data_end - xdp.data; |
1672 | |
1673 | /* It is known that the xdp_buff was prepared with metadata |
1674 | * support, so the metasize will never be negative. |
1675 | */ |
1676 | metasize = xdp.data - xdp.data_meta; |
1677 | } |
1678 | bpf_net_ctx_clear(bpf_net_ctx); |
1679 | rcu_read_unlock(); |
1680 | local_bh_enable(); |
1681 | |
1682 | return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, pad, |
1683 | metasize); |
1684 | |
1685 | out: |
1686 | bpf_net_ctx_clear(bpf_net_ctx); |
1687 | rcu_read_unlock(); |
1688 | local_bh_enable(); |
1689 | return NULL; |
1690 | } |
1691 | |
1692 | /* Get packet from user space buffer */ |
1693 | static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, |
1694 | void *msg_control, struct iov_iter *from, |
1695 | int noblock, bool more) |
1696 | { |
1697 | struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) }; |
1698 | struct sk_buff *skb; |
1699 | size_t total_len = iov_iter_count(i: from); |
1700 | size_t len = total_len, align = tun->align, linear; |
1701 | struct virtio_net_hdr gso = { 0 }; |
1702 | int good_linear; |
1703 | int copylen; |
1704 | int hdr_len = 0; |
1705 | bool zerocopy = false; |
1706 | int err; |
1707 | u32 rxhash = 0; |
1708 | int skb_xdp = 1; |
1709 | bool frags = tun_napi_frags_enabled(tfile); |
1710 | enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; |
1711 | |
1712 | if (!(tun->flags & IFF_NO_PI)) { |
1713 | if (len < sizeof(pi)) |
1714 | return -EINVAL; |
1715 | len -= sizeof(pi); |
1716 | |
1717 | if (!copy_from_iter_full(addr: &pi, bytes: sizeof(pi), i: from)) |
1718 | return -EFAULT; |
1719 | } |
1720 | |
1721 | if (tun->flags & IFF_VNET_HDR) { |
1722 | int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz); |
1723 | |
1724 | hdr_len = tun_vnet_hdr_get(sz: vnet_hdr_sz, flags: tun->flags, from, hdr: &gso); |
1725 | if (hdr_len < 0) |
1726 | return hdr_len; |
1727 | |
1728 | len -= vnet_hdr_sz; |
1729 | } |
1730 | |
1731 | if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) { |
1732 | align += NET_IP_ALIGN; |
1733 | if (unlikely(len < ETH_HLEN || (hdr_len && hdr_len < ETH_HLEN))) |
1734 | return -EINVAL; |
1735 | } |
1736 | |
1737 | good_linear = SKB_MAX_HEAD(align); |
1738 | |
1739 | if (msg_control) { |
1740 | struct iov_iter i = *from; |
1741 | |
1742 | /* There are 256 bytes to be copied in skb, so there is |
1743 | * enough room for skb expand head in case it is used. |
1744 | * The rest of the buffer is mapped from userspace. |
1745 | */ |
1746 | copylen = min(hdr_len ? hdr_len : GOODCOPY_LEN, good_linear); |
1747 | linear = copylen; |
1748 | iov_iter_advance(i: &i, bytes: copylen); |
1749 | if (iov_iter_npages(i: &i, INT_MAX) <= MAX_SKB_FRAGS) |
1750 | zerocopy = true; |
1751 | } |
1752 | |
1753 | if (!frags && tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) { |
1754 | /* For the packet that is not easy to be processed |
1755 | * (e.g gso or jumbo packet), we will do it at after |
1756 | * skb was created with generic XDP routine. |
1757 | */ |
1758 | skb = tun_build_skb(tun, tfile, from, hdr: &gso, len, skb_xdp: &skb_xdp); |
1759 | err = PTR_ERR_OR_ZERO(ptr: skb); |
1760 | if (err) |
1761 | goto drop; |
1762 | if (!skb) |
1763 | return total_len; |
1764 | } else { |
1765 | if (!zerocopy) { |
1766 | copylen = len; |
1767 | linear = min(hdr_len, good_linear); |
1768 | } |
1769 | |
1770 | if (frags) { |
1771 | mutex_lock(&tfile->napi_mutex); |
1772 | skb = tun_napi_alloc_frags(tfile, len: copylen, it: from); |
1773 | /* tun_napi_alloc_frags() enforces a layout for the skb. |
1774 | * If zerocopy is enabled, then this layout will be |
1775 | * overwritten by zerocopy_sg_from_iter(). |
1776 | */ |
1777 | zerocopy = false; |
1778 | } else { |
1779 | if (!linear) |
1780 | linear = min_t(size_t, good_linear, copylen); |
1781 | |
1782 | skb = tun_alloc_skb(tfile, prepad: align, len: copylen, linear, |
1783 | noblock); |
1784 | } |
1785 | |
1786 | err = PTR_ERR_OR_ZERO(ptr: skb); |
1787 | if (err) |
1788 | goto drop; |
1789 | |
1790 | if (zerocopy) |
1791 | err = zerocopy_sg_from_iter(skb, frm: from); |
1792 | else |
1793 | err = skb_copy_datagram_from_iter(skb, offset: 0, from, len); |
1794 | |
1795 | if (err) { |
1796 | err = -EFAULT; |
1797 | drop_reason = SKB_DROP_REASON_SKB_UCOPY_FAULT; |
1798 | goto drop; |
1799 | } |
1800 | } |
1801 | |
1802 | if (tun_vnet_hdr_to_skb(flags: tun->flags, skb, hdr: &gso)) { |
1803 | atomic_long_inc(v: &tun->rx_frame_errors); |
1804 | err = -EINVAL; |
1805 | goto free_skb; |
1806 | } |
1807 | |
1808 | switch (tun->flags & TUN_TYPE_MASK) { |
1809 | case IFF_TUN: |
1810 | if (tun->flags & IFF_NO_PI) { |
1811 | u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0; |
1812 | |
1813 | switch (ip_version) { |
1814 | case 4: |
1815 | pi.proto = htons(ETH_P_IP); |
1816 | break; |
1817 | case 6: |
1818 | pi.proto = htons(ETH_P_IPV6); |
1819 | break; |
1820 | default: |
1821 | err = -EINVAL; |
1822 | goto drop; |
1823 | } |
1824 | } |
1825 | |
1826 | skb_reset_mac_header(skb); |
1827 | skb->protocol = pi.proto; |
1828 | skb->dev = tun->dev; |
1829 | break; |
1830 | case IFF_TAP: |
1831 | if (frags && !pskb_may_pull(skb, ETH_HLEN)) { |
1832 | err = -ENOMEM; |
1833 | drop_reason = SKB_DROP_REASON_HDR_TRUNC; |
1834 | goto drop; |
1835 | } |
1836 | skb->protocol = eth_type_trans(skb, dev: tun->dev); |
1837 | break; |
1838 | } |
1839 | |
1840 | /* copy skb_ubuf_info for callback when skb has no error */ |
1841 | if (zerocopy) { |
1842 | skb_zcopy_init(skb, uarg: msg_control); |
1843 | } else if (msg_control) { |
1844 | struct ubuf_info *uarg = msg_control; |
1845 | uarg->ops->complete(NULL, uarg, false); |
1846 | } |
1847 | |
1848 | skb_reset_network_header(skb); |
1849 | skb_probe_transport_header(skb); |
1850 | skb_record_rx_queue(skb, rx_queue: tfile->queue_index); |
1851 | |
1852 | if (skb_xdp) { |
1853 | struct bpf_prog *xdp_prog; |
1854 | int ret; |
1855 | |
1856 | local_bh_disable(); |
1857 | rcu_read_lock(); |
1858 | xdp_prog = rcu_dereference(tun->xdp_prog); |
1859 | if (xdp_prog) { |
1860 | ret = do_xdp_generic(xdp_prog, pskb: &skb); |
1861 | if (ret != XDP_PASS) { |
1862 | rcu_read_unlock(); |
1863 | local_bh_enable(); |
1864 | goto unlock_frags; |
1865 | } |
1866 | } |
1867 | rcu_read_unlock(); |
1868 | local_bh_enable(); |
1869 | } |
1870 | |
1871 | /* Compute the costly rx hash only if needed for flow updates. |
1872 | * We may get a very small possibility of OOO during switching, not |
1873 | * worth to optimize. |
1874 | */ |
1875 | if (!rcu_access_pointer(tun->steering_prog) && tun->numqueues > 1 && |
1876 | !tfile->detached) |
1877 | rxhash = __skb_get_hash_symmetric(skb); |
1878 | |
1879 | rcu_read_lock(); |
1880 | if (unlikely(!(tun->dev->flags & IFF_UP))) { |
1881 | err = -EIO; |
1882 | rcu_read_unlock(); |
1883 | drop_reason = SKB_DROP_REASON_DEV_READY; |
1884 | goto drop; |
1885 | } |
1886 | |
1887 | if (frags) { |
1888 | u32 headlen; |
1889 | |
1890 | /* Exercise flow dissector code path. */ |
1891 | skb_push(skb, ETH_HLEN); |
1892 | headlen = eth_get_headlen(dev: tun->dev, data: skb->data, |
1893 | len: skb_headlen(skb)); |
1894 | |
1895 | if (unlikely(headlen > skb_headlen(skb))) { |
1896 | WARN_ON_ONCE(1); |
1897 | err = -ENOMEM; |
1898 | dev_core_stats_rx_dropped_inc(dev: tun->dev); |
1899 | napi_busy: |
1900 | napi_free_frags(napi: &tfile->napi); |
1901 | rcu_read_unlock(); |
1902 | mutex_unlock(lock: &tfile->napi_mutex); |
1903 | return err; |
1904 | } |
1905 | |
1906 | if (likely(napi_schedule_prep(&tfile->napi))) { |
1907 | local_bh_disable(); |
1908 | napi_gro_frags(napi: &tfile->napi); |
1909 | napi_complete(n: &tfile->napi); |
1910 | local_bh_enable(); |
1911 | } else { |
1912 | err = -EBUSY; |
1913 | goto napi_busy; |
1914 | } |
1915 | mutex_unlock(lock: &tfile->napi_mutex); |
1916 | } else if (tfile->napi_enabled) { |
1917 | struct sk_buff_head *queue = &tfile->sk.sk_write_queue; |
1918 | int queue_len; |
1919 | |
1920 | spin_lock_bh(lock: &queue->lock); |
1921 | |
1922 | if (unlikely(tfile->detached)) { |
1923 | spin_unlock_bh(lock: &queue->lock); |
1924 | rcu_read_unlock(); |
1925 | err = -EBUSY; |
1926 | goto free_skb; |
1927 | } |
1928 | |
1929 | __skb_queue_tail(list: queue, newsk: skb); |
1930 | queue_len = skb_queue_len(list_: queue); |
1931 | spin_unlock(lock: &queue->lock); |
1932 | |
1933 | if (!more || queue_len > NAPI_POLL_WEIGHT) |
1934 | napi_schedule(n: &tfile->napi); |
1935 | |
1936 | local_bh_enable(); |
1937 | } else if (!IS_ENABLED(CONFIG_4KSTACKS)) { |
1938 | tun_rx_batched(tun, tfile, skb, more); |
1939 | } else { |
1940 | netif_rx(skb); |
1941 | } |
1942 | rcu_read_unlock(); |
1943 | |
1944 | preempt_disable(); |
1945 | dev_sw_netstats_rx_add(dev: tun->dev, len); |
1946 | preempt_enable(); |
1947 | |
1948 | if (rxhash) |
1949 | tun_flow_update(tun, rxhash, tfile); |
1950 | |
1951 | return total_len; |
1952 | |
1953 | drop: |
1954 | if (err != -EAGAIN) |
1955 | dev_core_stats_rx_dropped_inc(dev: tun->dev); |
1956 | |
1957 | free_skb: |
1958 | if (!IS_ERR_OR_NULL(ptr: skb)) |
1959 | kfree_skb_reason(skb, reason: drop_reason); |
1960 | |
1961 | unlock_frags: |
1962 | if (frags) { |
1963 | tfile->napi.skb = NULL; |
1964 | mutex_unlock(lock: &tfile->napi_mutex); |
1965 | } |
1966 | |
1967 | return err ?: total_len; |
1968 | } |
1969 | |
1970 | static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from) |
1971 | { |
1972 | struct file *file = iocb->ki_filp; |
1973 | struct tun_file *tfile = file->private_data; |
1974 | struct tun_struct *tun = tun_get(tfile); |
1975 | ssize_t result; |
1976 | int noblock = 0; |
1977 | |
1978 | if (!tun) |
1979 | return -EBADFD; |
1980 | |
1981 | if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) |
1982 | noblock = 1; |
1983 | |
1984 | result = tun_get_user(tun, tfile, NULL, from, noblock, more: false); |
1985 | |
1986 | tun_put(tun); |
1987 | return result; |
1988 | } |
1989 | |
1990 | static ssize_t tun_put_user_xdp(struct tun_struct *tun, |
1991 | struct tun_file *tfile, |
1992 | struct xdp_frame *xdp_frame, |
1993 | struct iov_iter *iter) |
1994 | { |
1995 | int vnet_hdr_sz = 0; |
1996 | size_t size = xdp_frame->len; |
1997 | ssize_t ret; |
1998 | |
1999 | if (tun->flags & IFF_VNET_HDR) { |
2000 | struct virtio_net_hdr gso = { 0 }; |
2001 | |
2002 | vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz); |
2003 | ret = tun_vnet_hdr_put(sz: vnet_hdr_sz, iter, hdr: &gso); |
2004 | if (ret) |
2005 | return ret; |
2006 | } |
2007 | |
2008 | ret = copy_to_iter(addr: xdp_frame->data, bytes: size, i: iter) + vnet_hdr_sz; |
2009 | |
2010 | preempt_disable(); |
2011 | dev_sw_netstats_tx_add(dev: tun->dev, packets: 1, len: ret); |
2012 | preempt_enable(); |
2013 | |
2014 | return ret; |
2015 | } |
2016 | |
2017 | /* Put packet to the user space buffer */ |
2018 | static ssize_t tun_put_user(struct tun_struct *tun, |
2019 | struct tun_file *tfile, |
2020 | struct sk_buff *skb, |
2021 | struct iov_iter *iter) |
2022 | { |
2023 | struct tun_pi pi = { 0, skb->protocol }; |
2024 | ssize_t total; |
2025 | int vlan_offset = 0; |
2026 | int vlan_hlen = 0; |
2027 | int vnet_hdr_sz = 0; |
2028 | int ret; |
2029 | |
2030 | if (skb_vlan_tag_present(skb)) |
2031 | vlan_hlen = VLAN_HLEN; |
2032 | |
2033 | if (tun->flags & IFF_VNET_HDR) |
2034 | vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz); |
2035 | |
2036 | total = skb->len + vlan_hlen + vnet_hdr_sz; |
2037 | |
2038 | if (!(tun->flags & IFF_NO_PI)) { |
2039 | if (iov_iter_count(i: iter) < sizeof(pi)) |
2040 | return -EINVAL; |
2041 | |
2042 | total += sizeof(pi); |
2043 | if (iov_iter_count(i: iter) < total) { |
2044 | /* Packet will be striped */ |
2045 | pi.flags |= TUN_PKT_STRIP; |
2046 | } |
2047 | |
2048 | if (copy_to_iter(addr: &pi, bytes: sizeof(pi), i: iter) != sizeof(pi)) |
2049 | return -EFAULT; |
2050 | } |
2051 | |
2052 | if (vnet_hdr_sz) { |
2053 | struct virtio_net_hdr gso; |
2054 | |
2055 | ret = tun_vnet_hdr_from_skb(flags: tun->flags, dev: tun->dev, skb, hdr: &gso); |
2056 | if (ret) |
2057 | return ret; |
2058 | |
2059 | ret = tun_vnet_hdr_put(sz: vnet_hdr_sz, iter, hdr: &gso); |
2060 | if (ret) |
2061 | return ret; |
2062 | } |
2063 | |
2064 | if (vlan_hlen) { |
2065 | int ret; |
2066 | struct veth veth; |
2067 | |
2068 | veth.h_vlan_proto = skb->vlan_proto; |
2069 | veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb)); |
2070 | |
2071 | vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); |
2072 | |
2073 | ret = skb_copy_datagram_iter(from: skb, offset: 0, to: iter, size: vlan_offset); |
2074 | if (ret || !iov_iter_count(i: iter)) |
2075 | goto done; |
2076 | |
2077 | ret = copy_to_iter(addr: &veth, bytes: sizeof(veth), i: iter); |
2078 | if (ret != sizeof(veth) || !iov_iter_count(i: iter)) |
2079 | goto done; |
2080 | } |
2081 | |
2082 | skb_copy_datagram_iter(from: skb, offset: vlan_offset, to: iter, size: skb->len - vlan_offset); |
2083 | |
2084 | done: |
2085 | /* caller is in process context, */ |
2086 | preempt_disable(); |
2087 | dev_sw_netstats_tx_add(dev: tun->dev, packets: 1, len: skb->len + vlan_hlen); |
2088 | preempt_enable(); |
2089 | |
2090 | return total; |
2091 | } |
2092 | |
2093 | static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err) |
2094 | { |
2095 | DECLARE_WAITQUEUE(wait, current); |
2096 | void *ptr = NULL; |
2097 | int error = 0; |
2098 | |
2099 | ptr = ptr_ring_consume(r: &tfile->tx_ring); |
2100 | if (ptr) |
2101 | goto out; |
2102 | if (noblock) { |
2103 | error = -EAGAIN; |
2104 | goto out; |
2105 | } |
2106 | |
2107 | add_wait_queue(wq_head: &tfile->socket.wq.wait, wq_entry: &wait); |
2108 | |
2109 | while (1) { |
2110 | set_current_state(TASK_INTERRUPTIBLE); |
2111 | ptr = ptr_ring_consume(r: &tfile->tx_ring); |
2112 | if (ptr) |
2113 | break; |
2114 | if (signal_pending(current)) { |
2115 | error = -ERESTARTSYS; |
2116 | break; |
2117 | } |
2118 | if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) { |
2119 | error = -EFAULT; |
2120 | break; |
2121 | } |
2122 | |
2123 | schedule(); |
2124 | } |
2125 | |
2126 | __set_current_state(TASK_RUNNING); |
2127 | remove_wait_queue(wq_head: &tfile->socket.wq.wait, wq_entry: &wait); |
2128 | |
2129 | out: |
2130 | *err = error; |
2131 | return ptr; |
2132 | } |
2133 | |
2134 | static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile, |
2135 | struct iov_iter *to, |
2136 | int noblock, void *ptr) |
2137 | { |
2138 | ssize_t ret; |
2139 | int err; |
2140 | |
2141 | if (!iov_iter_count(i: to)) { |
2142 | tun_ptr_free(ptr); |
2143 | return 0; |
2144 | } |
2145 | |
2146 | if (!ptr) { |
2147 | /* Read frames from ring */ |
2148 | ptr = tun_ring_recv(tfile, noblock, err: &err); |
2149 | if (!ptr) |
2150 | return err; |
2151 | } |
2152 | |
2153 | if (tun_is_xdp_frame(ptr)) { |
2154 | struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr); |
2155 | |
2156 | ret = tun_put_user_xdp(tun, tfile, xdp_frame: xdpf, iter: to); |
2157 | xdp_return_frame(xdpf); |
2158 | } else { |
2159 | struct sk_buff *skb = ptr; |
2160 | |
2161 | ret = tun_put_user(tun, tfile, skb, iter: to); |
2162 | if (unlikely(ret < 0)) |
2163 | kfree_skb(skb); |
2164 | else |
2165 | consume_skb(skb); |
2166 | } |
2167 | |
2168 | return ret; |
2169 | } |
2170 | |
2171 | static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) |
2172 | { |
2173 | struct file *file = iocb->ki_filp; |
2174 | struct tun_file *tfile = file->private_data; |
2175 | struct tun_struct *tun = tun_get(tfile); |
2176 | ssize_t len = iov_iter_count(i: to), ret; |
2177 | int noblock = 0; |
2178 | |
2179 | if (!tun) |
2180 | return -EBADFD; |
2181 | |
2182 | if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) |
2183 | noblock = 1; |
2184 | |
2185 | ret = tun_do_read(tun, tfile, to, noblock, NULL); |
2186 | ret = min_t(ssize_t, ret, len); |
2187 | if (ret > 0) |
2188 | iocb->ki_pos = ret; |
2189 | tun_put(tun); |
2190 | return ret; |
2191 | } |
2192 | |
2193 | static void tun_prog_free(struct rcu_head *rcu) |
2194 | { |
2195 | struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu); |
2196 | |
2197 | bpf_prog_destroy(fp: prog->prog); |
2198 | kfree(objp: prog); |
2199 | } |
2200 | |
2201 | static int __tun_set_ebpf(struct tun_struct *tun, |
2202 | struct tun_prog __rcu **prog_p, |
2203 | struct bpf_prog *prog) |
2204 | { |
2205 | struct tun_prog *old, *new = NULL; |
2206 | |
2207 | if (prog) { |
2208 | new = kmalloc(sizeof(*new), GFP_KERNEL); |
2209 | if (!new) |
2210 | return -ENOMEM; |
2211 | new->prog = prog; |
2212 | } |
2213 | |
2214 | spin_lock_bh(lock: &tun->lock); |
2215 | old = rcu_dereference_protected(*prog_p, |
2216 | lockdep_is_held(&tun->lock)); |
2217 | rcu_assign_pointer(*prog_p, new); |
2218 | spin_unlock_bh(lock: &tun->lock); |
2219 | |
2220 | if (old) |
2221 | call_rcu(head: &old->rcu, func: tun_prog_free); |
2222 | |
2223 | return 0; |
2224 | } |
2225 | |
2226 | static void tun_free_netdev(struct net_device *dev) |
2227 | { |
2228 | struct tun_struct *tun = netdev_priv(dev); |
2229 | |
2230 | BUG_ON(!(list_empty(&tun->disabled))); |
2231 | |
2232 | tun_flow_uninit(tun); |
2233 | security_tun_dev_free_security(security: tun->security); |
2234 | __tun_set_ebpf(tun, prog_p: &tun->steering_prog, NULL); |
2235 | __tun_set_ebpf(tun, prog_p: &tun->filter_prog, NULL); |
2236 | } |
2237 | |
2238 | static void tun_setup(struct net_device *dev) |
2239 | { |
2240 | struct tun_struct *tun = netdev_priv(dev); |
2241 | |
2242 | tun->owner = INVALID_UID; |
2243 | tun->group = INVALID_GID; |
2244 | tun_default_link_ksettings(dev, cmd: &tun->link_ksettings); |
2245 | |
2246 | dev->ethtool_ops = &tun_ethtool_ops; |
2247 | dev->needs_free_netdev = true; |
2248 | dev->priv_destructor = tun_free_netdev; |
2249 | /* We prefer our own queue length */ |
2250 | dev->tx_queue_len = TUN_READQ_SIZE; |
2251 | } |
2252 | |
2253 | /* Trivial set of netlink ops to allow deleting tun or tap |
2254 | * device with netlink. |
2255 | */ |
2256 | static int tun_validate(struct nlattr *tb[], struct nlattr *data[], |
2257 | struct netlink_ext_ack *extack) |
2258 | { |
2259 | NL_SET_ERR_MSG(extack, |
2260 | "tun/tap creation via rtnetlink is not supported."); |
2261 | return -EOPNOTSUPP; |
2262 | } |
2263 | |
2264 | static size_t tun_get_size(const struct net_device *dev) |
2265 | { |
2266 | BUILD_BUG_ON(sizeof(u32) != sizeof(uid_t)); |
2267 | BUILD_BUG_ON(sizeof(u32) != sizeof(gid_t)); |
2268 | |
2269 | return nla_total_size(payload: sizeof(uid_t)) + /* OWNER */ |
2270 | nla_total_size(payload: sizeof(gid_t)) + /* GROUP */ |
2271 | nla_total_size(payload: sizeof(u8)) + /* TYPE */ |
2272 | nla_total_size(payload: sizeof(u8)) + /* PI */ |
2273 | nla_total_size(payload: sizeof(u8)) + /* VNET_HDR */ |
2274 | nla_total_size(payload: sizeof(u8)) + /* PERSIST */ |
2275 | nla_total_size(payload: sizeof(u8)) + /* MULTI_QUEUE */ |
2276 | nla_total_size(payload: sizeof(u32)) + /* NUM_QUEUES */ |
2277 | nla_total_size(payload: sizeof(u32)) + /* NUM_DISABLED_QUEUES */ |
2278 | 0; |
2279 | } |
2280 | |
2281 | static int tun_fill_info(struct sk_buff *skb, const struct net_device *dev) |
2282 | { |
2283 | struct tun_struct *tun = netdev_priv(dev); |
2284 | |
2285 | if (nla_put_u8(skb, attrtype: IFLA_TUN_TYPE, value: tun->flags & TUN_TYPE_MASK)) |
2286 | goto nla_put_failure; |
2287 | if (uid_valid(uid: tun->owner) && |
2288 | nla_put_u32(skb, attrtype: IFLA_TUN_OWNER, |
2289 | value: from_kuid_munged(current_user_ns(), uid: tun->owner))) |
2290 | goto nla_put_failure; |
2291 | if (gid_valid(gid: tun->group) && |
2292 | nla_put_u32(skb, attrtype: IFLA_TUN_GROUP, |
2293 | value: from_kgid_munged(current_user_ns(), gid: tun->group))) |
2294 | goto nla_put_failure; |
2295 | if (nla_put_u8(skb, attrtype: IFLA_TUN_PI, value: !(tun->flags & IFF_NO_PI))) |
2296 | goto nla_put_failure; |
2297 | if (nla_put_u8(skb, attrtype: IFLA_TUN_VNET_HDR, value: !!(tun->flags & IFF_VNET_HDR))) |
2298 | goto nla_put_failure; |
2299 | if (nla_put_u8(skb, attrtype: IFLA_TUN_PERSIST, value: !!(tun->flags & IFF_PERSIST))) |
2300 | goto nla_put_failure; |
2301 | if (nla_put_u8(skb, attrtype: IFLA_TUN_MULTI_QUEUE, |
2302 | value: !!(tun->flags & IFF_MULTI_QUEUE))) |
2303 | goto nla_put_failure; |
2304 | if (tun->flags & IFF_MULTI_QUEUE) { |
2305 | if (nla_put_u32(skb, attrtype: IFLA_TUN_NUM_QUEUES, value: tun->numqueues)) |
2306 | goto nla_put_failure; |
2307 | if (nla_put_u32(skb, attrtype: IFLA_TUN_NUM_DISABLED_QUEUES, |
2308 | value: tun->numdisabled)) |
2309 | goto nla_put_failure; |
2310 | } |
2311 | |
2312 | return 0; |
2313 | |
2314 | nla_put_failure: |
2315 | return -EMSGSIZE; |
2316 | } |
2317 | |
2318 | static struct rtnl_link_ops tun_link_ops __read_mostly = { |
2319 | .kind = DRV_NAME, |
2320 | .priv_size = sizeof(struct tun_struct), |
2321 | .setup = tun_setup, |
2322 | .validate = tun_validate, |
2323 | .get_size = tun_get_size, |
2324 | .fill_info = tun_fill_info, |
2325 | }; |
2326 | |
2327 | static void tun_sock_write_space(struct sock *sk) |
2328 | { |
2329 | struct tun_file *tfile; |
2330 | wait_queue_head_t *wqueue; |
2331 | |
2332 | if (!sock_writeable(sk)) |
2333 | return; |
2334 | |
2335 | if (!test_and_clear_bit(nr: SOCKWQ_ASYNC_NOSPACE, addr: &sk->sk_socket->flags)) |
2336 | return; |
2337 | |
2338 | wqueue = sk_sleep(sk); |
2339 | if (wqueue && waitqueue_active(wq_head: wqueue)) |
2340 | wake_up_interruptible_sync_poll(wqueue, EPOLLOUT | |
2341 | EPOLLWRNORM | EPOLLWRBAND); |
2342 | |
2343 | tfile = container_of(sk, struct tun_file, sk); |
2344 | kill_fasync(&tfile->fasync, SIGIO, POLL_OUT); |
2345 | } |
2346 | |
2347 | static void tun_put_page(struct tun_page *tpage) |
2348 | { |
2349 | if (tpage->page) |
2350 | __page_frag_cache_drain(page: tpage->page, count: tpage->count); |
2351 | } |
2352 | |
2353 | static int tun_xdp_one(struct tun_struct *tun, |
2354 | struct tun_file *tfile, |
2355 | struct xdp_buff *xdp, int *flush, |
2356 | struct tun_page *tpage) |
2357 | { |
2358 | unsigned int datasize = xdp->data_end - xdp->data; |
2359 | struct tun_xdp_hdr *hdr = xdp->data_hard_start; |
2360 | struct virtio_net_hdr *gso = &hdr->gso; |
2361 | struct bpf_prog *xdp_prog; |
2362 | struct sk_buff *skb = NULL; |
2363 | struct sk_buff_head *queue; |
2364 | u32 rxhash = 0, act; |
2365 | int buflen = hdr->buflen; |
2366 | int metasize = 0; |
2367 | int ret = 0; |
2368 | bool skb_xdp = false; |
2369 | struct page *page; |
2370 | |
2371 | if (unlikely(datasize < ETH_HLEN)) |
2372 | return -EINVAL; |
2373 | |
2374 | xdp_prog = rcu_dereference(tun->xdp_prog); |
2375 | if (xdp_prog) { |
2376 | if (gso->gso_type) { |
2377 | skb_xdp = true; |
2378 | goto build; |
2379 | } |
2380 | |
2381 | xdp_init_buff(xdp, frame_sz: buflen, rxq: &tfile->xdp_rxq); |
2382 | |
2383 | act = bpf_prog_run_xdp(prog: xdp_prog, xdp); |
2384 | ret = tun_xdp_act(tun, xdp_prog, xdp, act); |
2385 | if (ret < 0) { |
2386 | put_page(page: virt_to_head_page(x: xdp->data)); |
2387 | return ret; |
2388 | } |
2389 | |
2390 | switch (ret) { |
2391 | case XDP_REDIRECT: |
2392 | *flush = true; |
2393 | fallthrough; |
2394 | case XDP_TX: |
2395 | return 0; |
2396 | case XDP_PASS: |
2397 | break; |
2398 | default: |
2399 | page = virt_to_head_page(x: xdp->data); |
2400 | if (tpage->page == page) { |
2401 | ++tpage->count; |
2402 | } else { |
2403 | tun_put_page(tpage); |
2404 | tpage->page = page; |
2405 | tpage->count = 1; |
2406 | } |
2407 | return 0; |
2408 | } |
2409 | } |
2410 | |
2411 | build: |
2412 | skb = build_skb(data: xdp->data_hard_start, frag_size: buflen); |
2413 | if (!skb) { |
2414 | ret = -ENOMEM; |
2415 | goto out; |
2416 | } |
2417 | |
2418 | skb_reserve(skb, len: xdp->data - xdp->data_hard_start); |
2419 | skb_put(skb, len: xdp->data_end - xdp->data); |
2420 | |
2421 | /* The externally provided xdp_buff may have no metadata support, which |
2422 | * is marked by xdp->data_meta being xdp->data + 1. This will lead to a |
2423 | * metasize of -1 and is the reason why the condition checks for > 0. |
2424 | */ |
2425 | metasize = xdp->data - xdp->data_meta; |
2426 | if (metasize > 0) |
2427 | skb_metadata_set(skb, meta_len: metasize); |
2428 | |
2429 | if (tun_vnet_hdr_to_skb(flags: tun->flags, skb, hdr: gso)) { |
2430 | atomic_long_inc(v: &tun->rx_frame_errors); |
2431 | kfree_skb(skb); |
2432 | ret = -EINVAL; |
2433 | goto out; |
2434 | } |
2435 | |
2436 | skb->protocol = eth_type_trans(skb, dev: tun->dev); |
2437 | skb_reset_network_header(skb); |
2438 | skb_probe_transport_header(skb); |
2439 | skb_record_rx_queue(skb, rx_queue: tfile->queue_index); |
2440 | |
2441 | if (skb_xdp) { |
2442 | ret = do_xdp_generic(xdp_prog, pskb: &skb); |
2443 | if (ret != XDP_PASS) { |
2444 | ret = 0; |
2445 | goto out; |
2446 | } |
2447 | } |
2448 | |
2449 | if (!rcu_dereference(tun->steering_prog) && tun->numqueues > 1 && |
2450 | !tfile->detached) |
2451 | rxhash = __skb_get_hash_symmetric(skb); |
2452 | |
2453 | if (tfile->napi_enabled) { |
2454 | queue = &tfile->sk.sk_write_queue; |
2455 | spin_lock(lock: &queue->lock); |
2456 | |
2457 | if (unlikely(tfile->detached)) { |
2458 | spin_unlock(lock: &queue->lock); |
2459 | kfree_skb(skb); |
2460 | return -EBUSY; |
2461 | } |
2462 | |
2463 | __skb_queue_tail(list: queue, newsk: skb); |
2464 | spin_unlock(lock: &queue->lock); |
2465 | ret = 1; |
2466 | } else { |
2467 | netif_receive_skb(skb); |
2468 | ret = 0; |
2469 | } |
2470 | |
2471 | /* No need to disable preemption here since this function is |
2472 | * always called with bh disabled |
2473 | */ |
2474 | dev_sw_netstats_rx_add(dev: tun->dev, len: datasize); |
2475 | |
2476 | if (rxhash) |
2477 | tun_flow_update(tun, rxhash, tfile); |
2478 | |
2479 | out: |
2480 | return ret; |
2481 | } |
2482 | |
2483 | static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) |
2484 | { |
2485 | int ret, i; |
2486 | struct tun_file *tfile = container_of(sock, struct tun_file, socket); |
2487 | struct tun_struct *tun = tun_get(tfile); |
2488 | struct tun_msg_ctl *ctl = m->msg_control; |
2489 | struct xdp_buff *xdp; |
2490 | |
2491 | if (!tun) |
2492 | return -EBADFD; |
2493 | |
2494 | if (m->msg_controllen == sizeof(struct tun_msg_ctl) && |
2495 | ctl && ctl->type == TUN_MSG_PTR) { |
2496 | struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx; |
2497 | struct tun_page tpage; |
2498 | int n = ctl->num; |
2499 | int flush = 0, queued = 0; |
2500 | |
2501 | memset(&tpage, 0, sizeof(tpage)); |
2502 | |
2503 | local_bh_disable(); |
2504 | rcu_read_lock(); |
2505 | bpf_net_ctx = bpf_net_ctx_set(bpf_net_ctx: &__bpf_net_ctx); |
2506 | |
2507 | for (i = 0; i < n; i++) { |
2508 | xdp = &((struct xdp_buff *)ctl->ptr)[i]; |
2509 | ret = tun_xdp_one(tun, tfile, xdp, flush: &flush, tpage: &tpage); |
2510 | if (ret > 0) |
2511 | queued += ret; |
2512 | } |
2513 | |
2514 | if (flush) |
2515 | xdp_do_flush(); |
2516 | |
2517 | if (tfile->napi_enabled && queued > 0) |
2518 | napi_schedule(n: &tfile->napi); |
2519 | |
2520 | bpf_net_ctx_clear(bpf_net_ctx); |
2521 | rcu_read_unlock(); |
2522 | local_bh_enable(); |
2523 | |
2524 | tun_put_page(tpage: &tpage); |
2525 | |
2526 | ret = total_len; |
2527 | goto out; |
2528 | } |
2529 | |
2530 | ret = tun_get_user(tun, tfile, msg_control: ctl ? ctl->ptr : NULL, from: &m->msg_iter, |
2531 | noblock: m->msg_flags & MSG_DONTWAIT, |
2532 | more: m->msg_flags & MSG_MORE); |
2533 | out: |
2534 | tun_put(tun); |
2535 | return ret; |
2536 | } |
2537 | |
2538 | static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len, |
2539 | int flags) |
2540 | { |
2541 | struct tun_file *tfile = container_of(sock, struct tun_file, socket); |
2542 | struct tun_struct *tun = tun_get(tfile); |
2543 | void *ptr = m->msg_control; |
2544 | int ret; |
2545 | |
2546 | if (!tun) { |
2547 | ret = -EBADFD; |
2548 | goto out_free; |
2549 | } |
2550 | |
2551 | if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) { |
2552 | ret = -EINVAL; |
2553 | goto out_put_tun; |
2554 | } |
2555 | if (flags & MSG_ERRQUEUE) { |
2556 | ret = sock_recv_errqueue(sk: sock->sk, msg: m, len: total_len, |
2557 | SOL_PACKET, TUN_TX_TIMESTAMP); |
2558 | goto out; |
2559 | } |
2560 | ret = tun_do_read(tun, tfile, to: &m->msg_iter, noblock: flags & MSG_DONTWAIT, ptr); |
2561 | if (ret > (ssize_t)total_len) { |
2562 | m->msg_flags |= MSG_TRUNC; |
2563 | ret = flags & MSG_TRUNC ? ret : total_len; |
2564 | } |
2565 | out: |
2566 | tun_put(tun); |
2567 | return ret; |
2568 | |
2569 | out_put_tun: |
2570 | tun_put(tun); |
2571 | out_free: |
2572 | tun_ptr_free(ptr); |
2573 | return ret; |
2574 | } |
2575 | |
2576 | static int tun_ptr_peek_len(void *ptr) |
2577 | { |
2578 | if (likely(ptr)) { |
2579 | if (tun_is_xdp_frame(ptr)) { |
2580 | struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr); |
2581 | |
2582 | return xdpf->len; |
2583 | } |
2584 | return __skb_array_len_with_tag(skb: ptr); |
2585 | } else { |
2586 | return 0; |
2587 | } |
2588 | } |
2589 | |
2590 | static int tun_peek_len(struct socket *sock) |
2591 | { |
2592 | struct tun_file *tfile = container_of(sock, struct tun_file, socket); |
2593 | struct tun_struct *tun; |
2594 | int ret = 0; |
2595 | |
2596 | tun = tun_get(tfile); |
2597 | if (!tun) |
2598 | return 0; |
2599 | |
2600 | ret = PTR_RING_PEEK_CALL(&tfile->tx_ring, tun_ptr_peek_len); |
2601 | tun_put(tun); |
2602 | |
2603 | return ret; |
2604 | } |
2605 | |
2606 | /* Ops structure to mimic raw sockets with tun */ |
2607 | static const struct proto_ops tun_socket_ops = { |
2608 | .peek_len = tun_peek_len, |
2609 | .sendmsg = tun_sendmsg, |
2610 | .recvmsg = tun_recvmsg, |
2611 | }; |
2612 | |
2613 | static struct proto tun_proto = { |
2614 | .name = "tun", |
2615 | .owner = THIS_MODULE, |
2616 | .obj_size = sizeof(struct tun_file), |
2617 | }; |
2618 | |
2619 | static int tun_flags(struct tun_struct *tun) |
2620 | { |
2621 | return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP); |
2622 | } |
2623 | |
2624 | static ssize_t tun_flags_show(struct device *dev, struct device_attribute *attr, |
2625 | char *buf) |
2626 | { |
2627 | struct tun_struct *tun = netdev_priv(to_net_dev(dev)); |
2628 | return sysfs_emit(buf, fmt: "0x%x\n", tun_flags(tun)); |
2629 | } |
2630 | |
2631 | static ssize_t owner_show(struct device *dev, struct device_attribute *attr, |
2632 | char *buf) |
2633 | { |
2634 | struct tun_struct *tun = netdev_priv(to_net_dev(dev)); |
2635 | return uid_valid(uid: tun->owner)? |
2636 | sysfs_emit(buf, fmt: "%u\n", |
2637 | from_kuid_munged(current_user_ns(), uid: tun->owner)) : |
2638 | sysfs_emit(buf, fmt: "-1\n"); |
2639 | } |
2640 | |
2641 | static ssize_t group_show(struct device *dev, struct device_attribute *attr, |
2642 | char *buf) |
2643 | { |
2644 | struct tun_struct *tun = netdev_priv(to_net_dev(dev)); |
2645 | return gid_valid(gid: tun->group) ? |
2646 | sysfs_emit(buf, fmt: "%u\n", |
2647 | from_kgid_munged(current_user_ns(), gid: tun->group)) : |
2648 | sysfs_emit(buf, fmt: "-1\n"); |
2649 | } |
2650 | |
2651 | static DEVICE_ATTR_RO(tun_flags); |
2652 | static DEVICE_ATTR_RO(owner); |
2653 | static DEVICE_ATTR_RO(group); |
2654 | |
2655 | static struct attribute *tun_dev_attrs[] = { |
2656 | &dev_attr_tun_flags.attr, |
2657 | &dev_attr_owner.attr, |
2658 | &dev_attr_group.attr, |
2659 | NULL |
2660 | }; |
2661 | |
2662 | static const struct attribute_group tun_attr_group = { |
2663 | .attrs = tun_dev_attrs |
2664 | }; |
2665 | |
2666 | static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) |
2667 | { |
2668 | struct tun_struct *tun; |
2669 | struct tun_file *tfile = file->private_data; |
2670 | struct net_device *dev; |
2671 | int err; |
2672 | |
2673 | if (tfile->detached) |
2674 | return -EINVAL; |
2675 | |
2676 | if ((ifr->ifr_flags & IFF_NAPI_FRAGS)) { |
2677 | if (!capable(CAP_NET_ADMIN)) |
2678 | return -EPERM; |
2679 | |
2680 | if (!(ifr->ifr_flags & IFF_NAPI) || |
2681 | (ifr->ifr_flags & TUN_TYPE_MASK) != IFF_TAP) |
2682 | return -EINVAL; |
2683 | } |
2684 | |
2685 | dev = __dev_get_by_name(net, name: ifr->ifr_name); |
2686 | if (dev) { |
2687 | if (ifr->ifr_flags & IFF_TUN_EXCL) |
2688 | return -EBUSY; |
2689 | if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops) |
2690 | tun = netdev_priv(dev); |
2691 | else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops) |
2692 | tun = netdev_priv(dev); |
2693 | else |
2694 | return -EINVAL; |
2695 | |
2696 | if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) != |
2697 | !!(tun->flags & IFF_MULTI_QUEUE)) |
2698 | return -EINVAL; |
2699 | |
2700 | if (tun_not_capable(tun)) |
2701 | return -EPERM; |
2702 | err = security_tun_dev_open(security: tun->security); |
2703 | if (err < 0) |
2704 | return err; |
2705 | |
2706 | err = tun_attach(tun, file, skip_filter: ifr->ifr_flags & IFF_NOFILTER, |
2707 | napi: ifr->ifr_flags & IFF_NAPI, |
2708 | napi_frags: ifr->ifr_flags & IFF_NAPI_FRAGS, publish_tun: true); |
2709 | if (err < 0) |
2710 | return err; |
2711 | |
2712 | if (tun->flags & IFF_MULTI_QUEUE && |
2713 | (tun->numqueues + tun->numdisabled > 1)) { |
2714 | /* One or more queue has already been attached, no need |
2715 | * to initialize the device again. |
2716 | */ |
2717 | netdev_state_change(dev); |
2718 | return 0; |
2719 | } |
2720 | |
2721 | tun->flags = (tun->flags & ~TUN_FEATURES) | |
2722 | (ifr->ifr_flags & TUN_FEATURES); |
2723 | |
2724 | netdev_state_change(dev); |
2725 | } else { |
2726 | char *name; |
2727 | unsigned long flags = 0; |
2728 | int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ? |
2729 | MAX_TAP_QUEUES : 1; |
2730 | |
2731 | if (!ns_capable(ns: net->user_ns, CAP_NET_ADMIN)) |
2732 | return -EPERM; |
2733 | err = security_tun_dev_create(); |
2734 | if (err < 0) |
2735 | return err; |
2736 | |
2737 | /* Set dev type */ |
2738 | if (ifr->ifr_flags & IFF_TUN) { |
2739 | /* TUN device */ |
2740 | flags |= IFF_TUN; |
2741 | name = "tun%d"; |
2742 | } else if (ifr->ifr_flags & IFF_TAP) { |
2743 | /* TAP device */ |
2744 | flags |= IFF_TAP; |
2745 | name = "tap%d"; |
2746 | } else |
2747 | return -EINVAL; |
2748 | |
2749 | if (*ifr->ifr_name) |
2750 | name = ifr->ifr_name; |
2751 | |
2752 | dev = alloc_netdev_mqs(sizeof_priv: sizeof(struct tun_struct), name, |
2753 | NET_NAME_UNKNOWN, setup: tun_setup, txqs: queues, |
2754 | rxqs: queues); |
2755 | |
2756 | if (!dev) |
2757 | return -ENOMEM; |
2758 | |
2759 | dev_net_set(dev, net); |
2760 | dev->rtnl_link_ops = &tun_link_ops; |
2761 | dev->ifindex = tfile->ifindex; |
2762 | dev->sysfs_groups[0] = &tun_attr_group; |
2763 | |
2764 | tun = netdev_priv(dev); |
2765 | tun->dev = dev; |
2766 | tun->flags = flags; |
2767 | tun->txflt.count = 0; |
2768 | tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr); |
2769 | |
2770 | tun->align = NET_SKB_PAD; |
2771 | tun->filter_attached = false; |
2772 | tun->sndbuf = tfile->socket.sk->sk_sndbuf; |
2773 | tun->rx_batched = 0; |
2774 | RCU_INIT_POINTER(tun->steering_prog, NULL); |
2775 | |
2776 | tun->ifr = ifr; |
2777 | tun->file = file; |
2778 | |
2779 | tun_net_initialize(dev); |
2780 | |
2781 | err = register_netdevice(dev: tun->dev); |
2782 | if (err < 0) { |
2783 | free_netdev(dev); |
2784 | return err; |
2785 | } |
2786 | /* free_netdev() won't check refcnt, to avoid race |
2787 | * with dev_put() we need publish tun after registration. |
2788 | */ |
2789 | rcu_assign_pointer(tfile->tun, tun); |
2790 | } |
2791 | |
2792 | if (ifr->ifr_flags & IFF_NO_CARRIER) |
2793 | netif_carrier_off(dev: tun->dev); |
2794 | else |
2795 | netif_carrier_on(dev: tun->dev); |
2796 | |
2797 | /* Make sure persistent devices do not get stuck in |
2798 | * xoff state. |
2799 | */ |
2800 | if (netif_running(dev: tun->dev)) |
2801 | netif_tx_wake_all_queues(dev: tun->dev); |
2802 | |
2803 | strcpy(p: ifr->ifr_name, q: tun->dev->name); |
2804 | return 0; |
2805 | } |
2806 | |
2807 | static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr) |
2808 | { |
2809 | strcpy(p: ifr->ifr_name, q: tun->dev->name); |
2810 | |
2811 | ifr->ifr_flags = tun_flags(tun); |
2812 | |
2813 | } |
2814 | |
2815 | /* This is like a cut-down ethtool ops, except done via tun fd so no |
2816 | * privs required. */ |
2817 | static int set_offload(struct tun_struct *tun, unsigned long arg) |
2818 | { |
2819 | netdev_features_t features = 0; |
2820 | |
2821 | if (arg & TUN_F_CSUM) { |
2822 | features |= NETIF_F_HW_CSUM; |
2823 | arg &= ~TUN_F_CSUM; |
2824 | |
2825 | if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { |
2826 | if (arg & TUN_F_TSO_ECN) { |
2827 | features |= NETIF_F_TSO_ECN; |
2828 | arg &= ~TUN_F_TSO_ECN; |
2829 | } |
2830 | if (arg & TUN_F_TSO4) |
2831 | features |= NETIF_F_TSO; |
2832 | if (arg & TUN_F_TSO6) |
2833 | features |= NETIF_F_TSO6; |
2834 | arg &= ~(TUN_F_TSO4|TUN_F_TSO6); |
2835 | } |
2836 | |
2837 | arg &= ~TUN_F_UFO; |
2838 | |
2839 | /* TODO: for now USO4 and USO6 should work simultaneously */ |
2840 | if (arg & TUN_F_USO4 && arg & TUN_F_USO6) { |
2841 | features |= NETIF_F_GSO_UDP_L4; |
2842 | arg &= ~(TUN_F_USO4 | TUN_F_USO6); |
2843 | } |
2844 | } |
2845 | |
2846 | /* This gives the user a way to test for new features in future by |
2847 | * trying to set them. */ |
2848 | if (arg) |
2849 | return -EINVAL; |
2850 | |
2851 | tun->set_features = features; |
2852 | tun->dev->wanted_features &= ~TUN_USER_FEATURES; |
2853 | tun->dev->wanted_features |= features; |
2854 | netdev_update_features(dev: tun->dev); |
2855 | |
2856 | return 0; |
2857 | } |
2858 | |
2859 | static void tun_detach_filter(struct tun_struct *tun, int n) |
2860 | { |
2861 | int i; |
2862 | struct tun_file *tfile; |
2863 | |
2864 | for (i = 0; i < n; i++) { |
2865 | tfile = rtnl_dereference(tun->tfiles[i]); |
2866 | lock_sock(sk: tfile->socket.sk); |
2867 | sk_detach_filter(sk: tfile->socket.sk); |
2868 | release_sock(sk: tfile->socket.sk); |
2869 | } |
2870 | |
2871 | tun->filter_attached = false; |
2872 | } |
2873 | |
2874 | static int tun_attach_filter(struct tun_struct *tun) |
2875 | { |
2876 | int i, ret = 0; |
2877 | struct tun_file *tfile; |
2878 | |
2879 | for (i = 0; i < tun->numqueues; i++) { |
2880 | tfile = rtnl_dereference(tun->tfiles[i]); |
2881 | lock_sock(sk: tfile->socket.sk); |
2882 | ret = sk_attach_filter(fprog: &tun->fprog, sk: tfile->socket.sk); |
2883 | release_sock(sk: tfile->socket.sk); |
2884 | if (ret) { |
2885 | tun_detach_filter(tun, n: i); |
2886 | return ret; |
2887 | } |
2888 | } |
2889 | |
2890 | tun->filter_attached = true; |
2891 | return ret; |
2892 | } |
2893 | |
2894 | static void tun_set_sndbuf(struct tun_struct *tun) |
2895 | { |
2896 | struct tun_file *tfile; |
2897 | int i; |
2898 | |
2899 | for (i = 0; i < tun->numqueues; i++) { |
2900 | tfile = rtnl_dereference(tun->tfiles[i]); |
2901 | tfile->socket.sk->sk_sndbuf = tun->sndbuf; |
2902 | } |
2903 | } |
2904 | |
2905 | static int tun_set_queue(struct file *file, struct ifreq *ifr) |
2906 | { |
2907 | struct tun_file *tfile = file->private_data; |
2908 | struct tun_struct *tun; |
2909 | int ret = 0; |
2910 | |
2911 | rtnl_lock(); |
2912 | |
2913 | if (ifr->ifr_flags & IFF_ATTACH_QUEUE) { |
2914 | tun = tfile->detached; |
2915 | if (!tun) { |
2916 | ret = -EINVAL; |
2917 | goto unlock; |
2918 | } |
2919 | ret = security_tun_dev_attach_queue(security: tun->security); |
2920 | if (ret < 0) |
2921 | goto unlock; |
2922 | ret = tun_attach(tun, file, skip_filter: false, napi: tun->flags & IFF_NAPI, |
2923 | napi_frags: tun->flags & IFF_NAPI_FRAGS, publish_tun: true); |
2924 | } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) { |
2925 | tun = rtnl_dereference(tfile->tun); |
2926 | if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached) |
2927 | ret = -EINVAL; |
2928 | else |
2929 | __tun_detach(tfile, clean: false); |
2930 | } else |
2931 | ret = -EINVAL; |
2932 | |
2933 | if (ret >= 0) |
2934 | netdev_state_change(dev: tun->dev); |
2935 | |
2936 | unlock: |
2937 | rtnl_unlock(); |
2938 | return ret; |
2939 | } |
2940 | |
2941 | static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog __rcu **prog_p, |
2942 | void __user *data) |
2943 | { |
2944 | struct bpf_prog *prog; |
2945 | int fd; |
2946 | |
2947 | if (copy_from_user(to: &fd, from: data, n: sizeof(fd))) |
2948 | return -EFAULT; |
2949 | |
2950 | if (fd == -1) { |
2951 | prog = NULL; |
2952 | } else { |
2953 | prog = bpf_prog_get_type(ufd: fd, type: BPF_PROG_TYPE_SOCKET_FILTER); |
2954 | if (IS_ERR(ptr: prog)) |
2955 | return PTR_ERR(ptr: prog); |
2956 | } |
2957 | |
2958 | return __tun_set_ebpf(tun, prog_p, prog); |
2959 | } |
2960 | |
2961 | /* Return correct value for tun->dev->addr_len based on tun->dev->type. */ |
2962 | static unsigned char tun_get_addr_len(unsigned short type) |
2963 | { |
2964 | switch (type) { |
2965 | case ARPHRD_IP6GRE: |
2966 | case ARPHRD_TUNNEL6: |
2967 | return sizeof(struct in6_addr); |
2968 | case ARPHRD_IPGRE: |
2969 | case ARPHRD_TUNNEL: |
2970 | case ARPHRD_SIT: |
2971 | return 4; |
2972 | case ARPHRD_ETHER: |
2973 | return ETH_ALEN; |
2974 | case ARPHRD_IEEE802154: |
2975 | case ARPHRD_IEEE802154_MONITOR: |
2976 | return IEEE802154_EXTENDED_ADDR_LEN; |
2977 | case ARPHRD_PHONET_PIPE: |
2978 | case ARPHRD_PPP: |
2979 | case ARPHRD_NONE: |
2980 | return 0; |
2981 | case ARPHRD_6LOWPAN: |
2982 | return EUI64_ADDR_LEN; |
2983 | case ARPHRD_FDDI: |
2984 | return FDDI_K_ALEN; |
2985 | case ARPHRD_HIPPI: |
2986 | return HIPPI_ALEN; |
2987 | case ARPHRD_IEEE802: |
2988 | return FC_ALEN; |
2989 | case ARPHRD_ROSE: |
2990 | return ROSE_ADDR_LEN; |
2991 | case ARPHRD_NETROM: |
2992 | return AX25_ADDR_LEN; |
2993 | case ARPHRD_LOCALTLK: |
2994 | return LTALK_ALEN; |
2995 | default: |
2996 | return 0; |
2997 | } |
2998 | } |
2999 | |
3000 | static long __tun_chr_ioctl(struct file *file, unsigned int cmd, |
3001 | unsigned long arg, int ifreq_len) |
3002 | { |
3003 | struct tun_file *tfile = file->private_data; |
3004 | struct net *net = sock_net(sk: &tfile->sk); |
3005 | struct tun_struct *tun; |
3006 | void __user* argp = (void __user*)arg; |
3007 | unsigned int carrier; |
3008 | struct ifreq ifr; |
3009 | kuid_t owner; |
3010 | kgid_t group; |
3011 | int ifindex; |
3012 | int sndbuf; |
3013 | int ret; |
3014 | bool do_notify = false; |
3015 | |
3016 | if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || |
3017 | (_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) { |
3018 | if (copy_from_user(to: &ifr, from: argp, n: ifreq_len)) |
3019 | return -EFAULT; |
3020 | } else { |
3021 | memset(&ifr, 0, sizeof(ifr)); |
3022 | } |
3023 | if (cmd == TUNGETFEATURES) { |
3024 | /* Currently this just means: "what IFF flags are valid?". |
3025 | * This is needed because we never checked for invalid flags on |
3026 | * TUNSETIFF. |
3027 | */ |
3028 | return put_user(IFF_TUN | IFF_TAP | IFF_NO_CARRIER | |
3029 | TUN_FEATURES, (unsigned int __user*)argp); |
3030 | } else if (cmd == TUNSETQUEUE) { |
3031 | return tun_set_queue(file, ifr: &ifr); |
3032 | } else if (cmd == SIOCGSKNS) { |
3033 | if (!ns_capable(ns: net->user_ns, CAP_NET_ADMIN)) |
3034 | return -EPERM; |
3035 | return open_related_ns(ns: &net->ns, get_ns: get_net_ns); |
3036 | } |
3037 | |
3038 | rtnl_lock(); |
3039 | |
3040 | tun = tun_get(tfile); |
3041 | if (cmd == TUNSETIFF) { |
3042 | ret = -EEXIST; |
3043 | if (tun) |
3044 | goto unlock; |
3045 | |
3046 | ifr.ifr_name[IFNAMSIZ-1] = '\0'; |
3047 | |
3048 | ret = tun_set_iff(net, file, ifr: &ifr); |
3049 | |
3050 | if (ret) |
3051 | goto unlock; |
3052 | |
3053 | if (copy_to_user(to: argp, from: &ifr, n: ifreq_len)) |
3054 | ret = -EFAULT; |
3055 | goto unlock; |
3056 | } |
3057 | if (cmd == TUNSETIFINDEX) { |
3058 | ret = -EPERM; |
3059 | if (tun) |
3060 | goto unlock; |
3061 | |
3062 | ret = -EFAULT; |
3063 | if (copy_from_user(to: &ifindex, from: argp, n: sizeof(ifindex))) |
3064 | goto unlock; |
3065 | ret = -EINVAL; |
3066 | if (ifindex < 0) |
3067 | goto unlock; |
3068 | ret = 0; |
3069 | tfile->ifindex = ifindex; |
3070 | goto unlock; |
3071 | } |
3072 | |
3073 | ret = -EBADFD; |
3074 | if (!tun) |
3075 | goto unlock; |
3076 | |
3077 | netif_info(tun, drv, tun->dev, "tun_chr_ioctl cmd %u\n", cmd); |
3078 | |
3079 | net = dev_net(dev: tun->dev); |
3080 | ret = 0; |
3081 | switch (cmd) { |
3082 | case TUNGETIFF: |
3083 | tun_get_iff(tun, ifr: &ifr); |
3084 | |
3085 | if (tfile->detached) |
3086 | ifr.ifr_flags |= IFF_DETACH_QUEUE; |
3087 | if (!tfile->socket.sk->sk_filter) |
3088 | ifr.ifr_flags |= IFF_NOFILTER; |
3089 | |
3090 | if (copy_to_user(to: argp, from: &ifr, n: ifreq_len)) |
3091 | ret = -EFAULT; |
3092 | break; |
3093 | |
3094 | case TUNSETNOCSUM: |
3095 | /* Disable/Enable checksum */ |
3096 | |
3097 | /* [unimplemented] */ |
3098 | netif_info(tun, drv, tun->dev, "ignored: set checksum %s\n", |
3099 | arg ? "disabled": "enabled"); |
3100 | break; |
3101 | |
3102 | case TUNSETPERSIST: |
3103 | /* Disable/Enable persist mode. Keep an extra reference to the |
3104 | * module to prevent the module being unprobed. |
3105 | */ |
3106 | if (arg && !(tun->flags & IFF_PERSIST)) { |
3107 | tun->flags |= IFF_PERSIST; |
3108 | __module_get(THIS_MODULE); |
3109 | do_notify = true; |
3110 | } |
3111 | if (!arg && (tun->flags & IFF_PERSIST)) { |
3112 | tun->flags &= ~IFF_PERSIST; |
3113 | module_put(THIS_MODULE); |
3114 | do_notify = true; |
3115 | } |
3116 | |
3117 | netif_info(tun, drv, tun->dev, "persist %s\n", |
3118 | arg ? "enabled": "disabled"); |
3119 | break; |
3120 | |
3121 | case TUNSETOWNER: |
3122 | /* Set owner of the device */ |
3123 | owner = make_kuid(current_user_ns(), uid: arg); |
3124 | if (!uid_valid(uid: owner)) { |
3125 | ret = -EINVAL; |
3126 | break; |
3127 | } |
3128 | tun->owner = owner; |
3129 | do_notify = true; |
3130 | netif_info(tun, drv, tun->dev, "owner set to %u\n", |
3131 | from_kuid(&init_user_ns, tun->owner)); |
3132 | break; |
3133 | |
3134 | case TUNSETGROUP: |
3135 | /* Set group of the device */ |
3136 | group = make_kgid(current_user_ns(), gid: arg); |
3137 | if (!gid_valid(gid: group)) { |
3138 | ret = -EINVAL; |
3139 | break; |
3140 | } |
3141 | tun->group = group; |
3142 | do_notify = true; |
3143 | netif_info(tun, drv, tun->dev, "group set to %u\n", |
3144 | from_kgid(&init_user_ns, tun->group)); |
3145 | break; |
3146 | |
3147 | case TUNSETLINK: |
3148 | /* Only allow setting the type when the interface is down */ |
3149 | if (tun->dev->flags & IFF_UP) { |
3150 | netif_info(tun, drv, tun->dev, |
3151 | "Linktype set failed because interface is up\n"); |
3152 | ret = -EBUSY; |
3153 | } else { |
3154 | ret = call_netdevice_notifiers(val: NETDEV_PRE_TYPE_CHANGE, |
3155 | dev: tun->dev); |
3156 | ret = notifier_to_errno(ret); |
3157 | if (ret) { |
3158 | netif_info(tun, drv, tun->dev, |
3159 | "Refused to change device type\n"); |
3160 | break; |
3161 | } |
3162 | tun->dev->type = (int) arg; |
3163 | tun->dev->addr_len = tun_get_addr_len(type: tun->dev->type); |
3164 | netif_info(tun, drv, tun->dev, "linktype set to %d\n", |
3165 | tun->dev->type); |
3166 | call_netdevice_notifiers(val: NETDEV_POST_TYPE_CHANGE, |
3167 | dev: tun->dev); |
3168 | } |
3169 | break; |
3170 | |
3171 | case TUNSETDEBUG: |
3172 | tun->msg_enable = (u32)arg; |
3173 | break; |
3174 | |
3175 | case TUNSETOFFLOAD: |
3176 | ret = set_offload(tun, arg); |
3177 | break; |
3178 | |
3179 | case TUNSETTXFILTER: |
3180 | /* Can be set only for TAPs */ |
3181 | ret = -EINVAL; |
3182 | if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) |
3183 | break; |
3184 | ret = update_filter(filter: &tun->txflt, arg: (void __user *)arg); |
3185 | break; |
3186 | |
3187 | case SIOCGIFHWADDR: |
3188 | /* Get hw address */ |
3189 | dev_get_mac_address(sa: &ifr.ifr_hwaddr, net, dev_name: tun->dev->name); |
3190 | if (copy_to_user(to: argp, from: &ifr, n: ifreq_len)) |
3191 | ret = -EFAULT; |
3192 | break; |
3193 | |
3194 | case SIOCSIFHWADDR: |
3195 | /* Set hw address */ |
3196 | if (tun->dev->addr_len > sizeof(ifr.ifr_hwaddr)) { |
3197 | ret = -EINVAL; |
3198 | break; |
3199 | } |
3200 | ret = dev_set_mac_address_user(dev: tun->dev, |
3201 | ss: (struct sockaddr_storage *)&ifr.ifr_hwaddr, |
3202 | NULL); |
3203 | break; |
3204 | |
3205 | case TUNGETSNDBUF: |
3206 | sndbuf = tfile->socket.sk->sk_sndbuf; |
3207 | if (copy_to_user(to: argp, from: &sndbuf, n: sizeof(sndbuf))) |
3208 | ret = -EFAULT; |
3209 | break; |
3210 | |
3211 | case TUNSETSNDBUF: |
3212 | if (copy_from_user(to: &sndbuf, from: argp, n: sizeof(sndbuf))) { |
3213 | ret = -EFAULT; |
3214 | break; |
3215 | } |
3216 | if (sndbuf <= 0) { |
3217 | ret = -EINVAL; |
3218 | break; |
3219 | } |
3220 | |
3221 | tun->sndbuf = sndbuf; |
3222 | tun_set_sndbuf(tun); |
3223 | break; |
3224 | |
3225 | case TUNATTACHFILTER: |
3226 | /* Can be set only for TAPs */ |
3227 | ret = -EINVAL; |
3228 | if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) |
3229 | break; |
3230 | ret = -EFAULT; |
3231 | if (copy_from_user(to: &tun->fprog, from: argp, n: sizeof(tun->fprog))) |
3232 | break; |
3233 | |
3234 | ret = tun_attach_filter(tun); |
3235 | break; |
3236 | |
3237 | case TUNDETACHFILTER: |
3238 | /* Can be set only for TAPs */ |
3239 | ret = -EINVAL; |
3240 | if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) |
3241 | break; |
3242 | ret = 0; |
3243 | tun_detach_filter(tun, n: tun->numqueues); |
3244 | break; |
3245 | |
3246 | case TUNGETFILTER: |
3247 | ret = -EINVAL; |
3248 | if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP) |
3249 | break; |
3250 | ret = -EFAULT; |
3251 | if (copy_to_user(to: argp, from: &tun->fprog, n: sizeof(tun->fprog))) |
3252 | break; |
3253 | ret = 0; |
3254 | break; |
3255 | |
3256 | case TUNSETSTEERINGEBPF: |
3257 | ret = tun_set_ebpf(tun, prog_p: &tun->steering_prog, data: argp); |
3258 | break; |
3259 | |
3260 | case TUNSETFILTEREBPF: |
3261 | ret = tun_set_ebpf(tun, prog_p: &tun->filter_prog, data: argp); |
3262 | break; |
3263 | |
3264 | case TUNSETCARRIER: |
3265 | ret = -EFAULT; |
3266 | if (copy_from_user(to: &carrier, from: argp, n: sizeof(carrier))) |
3267 | goto unlock; |
3268 | |
3269 | ret = tun_net_change_carrier(dev: tun->dev, new_carrier: (bool)carrier); |
3270 | break; |
3271 | |
3272 | case TUNGETDEVNETNS: |
3273 | ret = -EPERM; |
3274 | if (!ns_capable(ns: net->user_ns, CAP_NET_ADMIN)) |
3275 | goto unlock; |
3276 | ret = open_related_ns(ns: &net->ns, get_ns: get_net_ns); |
3277 | break; |
3278 | |
3279 | default: |
3280 | ret = tun_vnet_ioctl(vnet_hdr_sz: &tun->vnet_hdr_sz, flags: &tun->flags, cmd, sp: argp); |
3281 | break; |
3282 | } |
3283 | |
3284 | if (do_notify) |
3285 | netdev_state_change(dev: tun->dev); |
3286 | |
3287 | unlock: |
3288 | rtnl_unlock(); |
3289 | if (tun) |
3290 | tun_put(tun); |
3291 | return ret; |
3292 | } |
3293 | |
3294 | static long tun_chr_ioctl(struct file *file, |
3295 | unsigned int cmd, unsigned long arg) |
3296 | { |
3297 | return __tun_chr_ioctl(file, cmd, arg, ifreq_len: sizeof (struct ifreq)); |
3298 | } |
3299 | |
3300 | #ifdef CONFIG_COMPAT |
3301 | static long tun_chr_compat_ioctl(struct file *file, |
3302 | unsigned int cmd, unsigned long arg) |
3303 | { |
3304 | switch (cmd) { |
3305 | case TUNSETIFF: |
3306 | case TUNGETIFF: |
3307 | case TUNSETTXFILTER: |
3308 | case TUNGETSNDBUF: |
3309 | case TUNSETSNDBUF: |
3310 | case SIOCGIFHWADDR: |
3311 | case SIOCSIFHWADDR: |
3312 | arg = (unsigned long)compat_ptr(uptr: arg); |
3313 | break; |
3314 | default: |
3315 | arg = (compat_ulong_t)arg; |
3316 | break; |
3317 | } |
3318 | |
3319 | /* |
3320 | * compat_ifreq is shorter than ifreq, so we must not access beyond |
3321 | * the end of that structure. All fields that are used in this |
3322 | * driver are compatible though, we don't need to convert the |
3323 | * contents. |
3324 | */ |
3325 | return __tun_chr_ioctl(file, cmd, arg, ifreq_len: sizeof(struct compat_ifreq)); |
3326 | } |
3327 | #endif /* CONFIG_COMPAT */ |
3328 | |
3329 | static int tun_chr_fasync(int fd, struct file *file, int on) |
3330 | { |
3331 | struct tun_file *tfile = file->private_data; |
3332 | int ret; |
3333 | |
3334 | if (on) { |
3335 | ret = file_f_owner_allocate(file); |
3336 | if (ret) |
3337 | goto out; |
3338 | } |
3339 | |
3340 | if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0) |
3341 | goto out; |
3342 | |
3343 | if (on) { |
3344 | __f_setown(filp: file, task_pid(current), PIDTYPE_TGID, force: 0); |
3345 | tfile->flags |= TUN_FASYNC; |
3346 | } else |
3347 | tfile->flags &= ~TUN_FASYNC; |
3348 | ret = 0; |
3349 | out: |
3350 | return ret; |
3351 | } |
3352 | |
3353 | static int tun_chr_open(struct inode *inode, struct file * file) |
3354 | { |
3355 | struct net *net = current->nsproxy->net_ns; |
3356 | struct tun_file *tfile; |
3357 | |
3358 | tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, |
3359 | prot: &tun_proto, kern: 0); |
3360 | if (!tfile) |
3361 | return -ENOMEM; |
3362 | if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) { |
3363 | sk_free(sk: &tfile->sk); |
3364 | return -ENOMEM; |
3365 | } |
3366 | |
3367 | mutex_init(&tfile->napi_mutex); |
3368 | RCU_INIT_POINTER(tfile->tun, NULL); |
3369 | tfile->flags = 0; |
3370 | tfile->ifindex = 0; |
3371 | |
3372 | init_waitqueue_head(&tfile->socket.wq.wait); |
3373 | |
3374 | tfile->socket.file = file; |
3375 | tfile->socket.ops = &tun_socket_ops; |
3376 | |
3377 | sock_init_data_uid(sock: &tfile->socket, sk: &tfile->sk, current_fsuid()); |
3378 | |
3379 | tfile->sk.sk_write_space = tun_sock_write_space; |
3380 | tfile->sk.sk_sndbuf = INT_MAX; |
3381 | |
3382 | file->private_data = tfile; |
3383 | INIT_LIST_HEAD(list: &tfile->next); |
3384 | |
3385 | sock_set_flag(sk: &tfile->sk, flag: SOCK_ZEROCOPY); |
3386 | |
3387 | /* tun groks IOCB_NOWAIT just fine, mark it as such */ |
3388 | file->f_mode |= FMODE_NOWAIT; |
3389 | return 0; |
3390 | } |
3391 | |
3392 | static int tun_chr_close(struct inode *inode, struct file *file) |
3393 | { |
3394 | struct tun_file *tfile = file->private_data; |
3395 | |
3396 | tun_detach(tfile, clean: true); |
3397 | |
3398 | return 0; |
3399 | } |
3400 | |
3401 | #ifdef CONFIG_PROC_FS |
3402 | static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file) |
3403 | { |
3404 | struct tun_file *tfile = file->private_data; |
3405 | struct tun_struct *tun; |
3406 | struct ifreq ifr; |
3407 | |
3408 | memset(&ifr, 0, sizeof(ifr)); |
3409 | |
3410 | rtnl_lock(); |
3411 | tun = tun_get(tfile); |
3412 | if (tun) |
3413 | tun_get_iff(tun, ifr: &ifr); |
3414 | rtnl_unlock(); |
3415 | |
3416 | if (tun) |
3417 | tun_put(tun); |
3418 | |
3419 | seq_printf(m, fmt: "iff:\t%s\n", ifr.ifr_name); |
3420 | } |
3421 | #endif |
3422 | |
3423 | static const struct file_operations tun_fops = { |
3424 | .owner = THIS_MODULE, |
3425 | .read_iter = tun_chr_read_iter, |
3426 | .write_iter = tun_chr_write_iter, |
3427 | .poll = tun_chr_poll, |
3428 | .unlocked_ioctl = tun_chr_ioctl, |
3429 | #ifdef CONFIG_COMPAT |
3430 | .compat_ioctl = tun_chr_compat_ioctl, |
3431 | #endif |
3432 | .open = tun_chr_open, |
3433 | .release = tun_chr_close, |
3434 | .fasync = tun_chr_fasync, |
3435 | #ifdef CONFIG_PROC_FS |
3436 | .show_fdinfo = tun_chr_show_fdinfo, |
3437 | #endif |
3438 | }; |
3439 | |
3440 | static struct miscdevice tun_miscdev = { |
3441 | .minor = TUN_MINOR, |
3442 | .name = "tun", |
3443 | .nodename = "net/tun", |
3444 | .fops = &tun_fops, |
3445 | }; |
3446 | |
3447 | /* ethtool interface */ |
3448 | |
3449 | static void tun_default_link_ksettings(struct net_device *dev, |
3450 | struct ethtool_link_ksettings *cmd) |
3451 | { |
3452 | ethtool_link_ksettings_zero_link_mode(cmd, supported); |
3453 | ethtool_link_ksettings_zero_link_mode(cmd, advertising); |
3454 | cmd->base.speed = SPEED_10000; |
3455 | cmd->base.duplex = DUPLEX_FULL; |
3456 | cmd->base.port = PORT_TP; |
3457 | cmd->base.phy_address = 0; |
3458 | cmd->base.autoneg = AUTONEG_DISABLE; |
3459 | } |
3460 | |
3461 | static int tun_get_link_ksettings(struct net_device *dev, |
3462 | struct ethtool_link_ksettings *cmd) |
3463 | { |
3464 | struct tun_struct *tun = netdev_priv(dev); |
3465 | |
3466 | memcpy(cmd, &tun->link_ksettings, sizeof(*cmd)); |
3467 | return 0; |
3468 | } |
3469 | |
3470 | static int tun_set_link_ksettings(struct net_device *dev, |
3471 | const struct ethtool_link_ksettings *cmd) |
3472 | { |
3473 | struct tun_struct *tun = netdev_priv(dev); |
3474 | |
3475 | memcpy(&tun->link_ksettings, cmd, sizeof(*cmd)); |
3476 | return 0; |
3477 | } |
3478 | |
3479 | static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) |
3480 | { |
3481 | struct tun_struct *tun = netdev_priv(dev); |
3482 | |
3483 | strscpy(info->driver, DRV_NAME, sizeof(info->driver)); |
3484 | strscpy(info->version, DRV_VERSION, sizeof(info->version)); |
3485 | |
3486 | switch (tun->flags & TUN_TYPE_MASK) { |
3487 | case IFF_TUN: |
3488 | strscpy(info->bus_info, "tun", sizeof(info->bus_info)); |
3489 | break; |
3490 | case IFF_TAP: |
3491 | strscpy(info->bus_info, "tap", sizeof(info->bus_info)); |
3492 | break; |
3493 | } |
3494 | } |
3495 | |
3496 | static u32 tun_get_msglevel(struct net_device *dev) |
3497 | { |
3498 | struct tun_struct *tun = netdev_priv(dev); |
3499 | |
3500 | return tun->msg_enable; |
3501 | } |
3502 | |
3503 | static void tun_set_msglevel(struct net_device *dev, u32 value) |
3504 | { |
3505 | struct tun_struct *tun = netdev_priv(dev); |
3506 | |
3507 | tun->msg_enable = value; |
3508 | } |
3509 | |
3510 | static int tun_get_coalesce(struct net_device *dev, |
3511 | struct ethtool_coalesce *ec, |
3512 | struct kernel_ethtool_coalesce *kernel_coal, |
3513 | struct netlink_ext_ack *extack) |
3514 | { |
3515 | struct tun_struct *tun = netdev_priv(dev); |
3516 | |
3517 | ec->rx_max_coalesced_frames = tun->rx_batched; |
3518 | |
3519 | return 0; |
3520 | } |
3521 | |
3522 | static int tun_set_coalesce(struct net_device *dev, |
3523 | struct ethtool_coalesce *ec, |
3524 | struct kernel_ethtool_coalesce *kernel_coal, |
3525 | struct netlink_ext_ack *extack) |
3526 | { |
3527 | struct tun_struct *tun = netdev_priv(dev); |
3528 | |
3529 | if (ec->rx_max_coalesced_frames > NAPI_POLL_WEIGHT) |
3530 | tun->rx_batched = NAPI_POLL_WEIGHT; |
3531 | else |
3532 | tun->rx_batched = ec->rx_max_coalesced_frames; |
3533 | |
3534 | return 0; |
3535 | } |
3536 | |
3537 | static void tun_get_channels(struct net_device *dev, |
3538 | struct ethtool_channels *channels) |
3539 | { |
3540 | struct tun_struct *tun = netdev_priv(dev); |
3541 | |
3542 | channels->combined_count = tun->numqueues; |
3543 | channels->max_combined = tun->flags & IFF_MULTI_QUEUE ? MAX_TAP_QUEUES : 1; |
3544 | } |
3545 | |
3546 | static const struct ethtool_ops tun_ethtool_ops = { |
3547 | .supported_coalesce_params = ETHTOOL_COALESCE_RX_MAX_FRAMES, |
3548 | .get_drvinfo = tun_get_drvinfo, |
3549 | .get_msglevel = tun_get_msglevel, |
3550 | .set_msglevel = tun_set_msglevel, |
3551 | .get_link = ethtool_op_get_link, |
3552 | .get_channels = tun_get_channels, |
3553 | .get_ts_info = ethtool_op_get_ts_info, |
3554 | .get_coalesce = tun_get_coalesce, |
3555 | .set_coalesce = tun_set_coalesce, |
3556 | .get_link_ksettings = tun_get_link_ksettings, |
3557 | .set_link_ksettings = tun_set_link_ksettings, |
3558 | }; |
3559 | |
3560 | static int tun_queue_resize(struct tun_struct *tun) |
3561 | { |
3562 | struct net_device *dev = tun->dev; |
3563 | struct tun_file *tfile; |
3564 | struct ptr_ring **rings; |
3565 | int n = tun->numqueues + tun->numdisabled; |
3566 | int ret, i; |
3567 | |
3568 | rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL); |
3569 | if (!rings) |
3570 | return -ENOMEM; |
3571 | |
3572 | for (i = 0; i < tun->numqueues; i++) { |
3573 | tfile = rtnl_dereference(tun->tfiles[i]); |
3574 | rings[i] = &tfile->tx_ring; |
3575 | } |
3576 | list_for_each_entry(tfile, &tun->disabled, next) |
3577 | rings[i++] = &tfile->tx_ring; |
3578 | |
3579 | ret = ptr_ring_resize_multiple_bh(rings, n, |
3580 | dev->tx_queue_len, GFP_KERNEL, |
3581 | tun_ptr_free); |
3582 | |
3583 | kfree(objp: rings); |
3584 | return ret; |
3585 | } |
3586 | |
3587 | static int tun_device_event(struct notifier_block *unused, |
3588 | unsigned long event, void *ptr) |
3589 | { |
3590 | struct net_device *dev = netdev_notifier_info_to_dev(info: ptr); |
3591 | struct tun_struct *tun = netdev_priv(dev); |
3592 | int i; |
3593 | |
3594 | if (dev->rtnl_link_ops != &tun_link_ops) |
3595 | return NOTIFY_DONE; |
3596 | |
3597 | switch (event) { |
3598 | case NETDEV_CHANGE_TX_QUEUE_LEN: |
3599 | if (tun_queue_resize(tun)) |
3600 | return NOTIFY_BAD; |
3601 | break; |
3602 | case NETDEV_UP: |
3603 | for (i = 0; i < tun->numqueues; i++) { |
3604 | struct tun_file *tfile; |
3605 | |
3606 | tfile = rtnl_dereference(tun->tfiles[i]); |
3607 | tfile->socket.sk->sk_write_space(tfile->socket.sk); |
3608 | } |
3609 | break; |
3610 | default: |
3611 | break; |
3612 | } |
3613 | |
3614 | return NOTIFY_DONE; |
3615 | } |
3616 | |
3617 | static struct notifier_block tun_notifier_block __read_mostly = { |
3618 | .notifier_call = tun_device_event, |
3619 | }; |
3620 | |
3621 | static int __init tun_init(void) |
3622 | { |
3623 | int ret = 0; |
3624 | |
3625 | pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION); |
3626 | |
3627 | ret = rtnl_link_register(ops: &tun_link_ops); |
3628 | if (ret) { |
3629 | pr_err("Can't register link_ops\n"); |
3630 | goto err_linkops; |
3631 | } |
3632 | |
3633 | ret = misc_register(misc: &tun_miscdev); |
3634 | if (ret) { |
3635 | pr_err("Can't register misc device %d\n", TUN_MINOR); |
3636 | goto err_misc; |
3637 | } |
3638 | |
3639 | ret = register_netdevice_notifier(nb: &tun_notifier_block); |
3640 | if (ret) { |
3641 | pr_err("Can't register netdevice notifier\n"); |
3642 | goto err_notifier; |
3643 | } |
3644 | |
3645 | return 0; |
3646 | |
3647 | err_notifier: |
3648 | misc_deregister(misc: &tun_miscdev); |
3649 | err_misc: |
3650 | rtnl_link_unregister(ops: &tun_link_ops); |
3651 | err_linkops: |
3652 | return ret; |
3653 | } |
3654 | |
3655 | static void __exit tun_cleanup(void) |
3656 | { |
3657 | misc_deregister(misc: &tun_miscdev); |
3658 | rtnl_link_unregister(ops: &tun_link_ops); |
3659 | unregister_netdevice_notifier(nb: &tun_notifier_block); |
3660 | } |
3661 | |
3662 | /* Get an underlying socket object from tun file. Returns error unless file is |
3663 | * attached to a device. The returned object works like a packet socket, it |
3664 | * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for |
3665 | * holding a reference to the file for as long as the socket is in use. */ |
3666 | struct socket *tun_get_socket(struct file *file) |
3667 | { |
3668 | struct tun_file *tfile; |
3669 | if (file->f_op != &tun_fops) |
3670 | return ERR_PTR(error: -EINVAL); |
3671 | tfile = file->private_data; |
3672 | if (!tfile) |
3673 | return ERR_PTR(error: -EBADFD); |
3674 | return &tfile->socket; |
3675 | } |
3676 | EXPORT_SYMBOL_GPL(tun_get_socket); |
3677 | |
3678 | struct ptr_ring *tun_get_tx_ring(struct file *file) |
3679 | { |
3680 | struct tun_file *tfile; |
3681 | |
3682 | if (file->f_op != &tun_fops) |
3683 | return ERR_PTR(error: -EINVAL); |
3684 | tfile = file->private_data; |
3685 | if (!tfile) |
3686 | return ERR_PTR(error: -EBADFD); |
3687 | return &tfile->tx_ring; |
3688 | } |
3689 | EXPORT_SYMBOL_GPL(tun_get_tx_ring); |
3690 | |
3691 | module_init(tun_init); |
3692 | module_exit(tun_cleanup); |
3693 | MODULE_DESCRIPTION(DRV_DESCRIPTION); |
3694 | MODULE_AUTHOR(DRV_COPYRIGHT); |
3695 | MODULE_LICENSE("GPL"); |
3696 | MODULE_ALIAS_MISCDEV(TUN_MINOR); |
3697 | MODULE_ALIAS("devname:net/tun"); |
3698 |
Definitions
- tap_filter
- tun_file
- tun_page
- tun_flow_entry
- tun_prog
- tun_struct
- veth
- tun_napi_receive
- tun_napi_poll
- tun_napi_init
- tun_napi_enable
- tun_napi_disable
- tun_napi_del
- tun_napi_frags_enabled
- tun_hashfn
- tun_flow_find
- tun_flow_create
- tun_flow_delete
- tun_flow_flush
- tun_flow_delete_by_queue
- tun_flow_cleanup
- tun_flow_update
- tun_flow_save_rps_rxhash
- tun_automq_select_queue
- tun_ebpf_select_queue
- tun_select_queue
- tun_not_capable
- tun_set_real_num_queues
- tun_disable_queue
- tun_enable_queue
- tun_ptr_free
- tun_queue_purge
- __tun_detach
- tun_detach
- tun_detach_all
- tun_attach
- tun_get
- tun_put
- addr_hash_set
- addr_hash_test
- update_filter
- run_filter
- check_filter
- tun_ethtool_ops
- tun_net_init
- tun_net_uninit
- tun_net_open
- tun_net_close
- tun_automq_xmit
- run_ebpf_filter
- tun_net_xmit
- tun_net_mclist
- tun_net_fix_features
- tun_set_headroom
- tun_net_get_stats64
- tun_xdp_set
- tun_xdp
- tun_net_change_carrier
- tun_netdev_ops
- __tun_xdp_flush_tfile
- tun_xdp_xmit
- tun_xdp_tx
- tap_netdev_ops
- tun_flow_init
- tun_flow_uninit
- tun_net_initialize
- tun_sock_writeable
- tun_chr_poll
- tun_napi_alloc_frags
- tun_alloc_skb
- tun_rx_batched
- tun_can_build_skb
- __tun_build_skb
- tun_xdp_act
- tun_build_skb
- tun_get_user
- tun_chr_write_iter
- tun_put_user_xdp
- tun_put_user
- tun_ring_recv
- tun_do_read
- tun_chr_read_iter
- tun_prog_free
- __tun_set_ebpf
- tun_free_netdev
- tun_setup
- tun_validate
- tun_get_size
- tun_fill_info
- tun_link_ops
- tun_sock_write_space
- tun_put_page
- tun_xdp_one
- tun_sendmsg
- tun_recvmsg
- tun_ptr_peek_len
- tun_peek_len
- tun_socket_ops
- tun_proto
- tun_flags
- tun_flags_show
- owner_show
- group_show
- tun_dev_attrs
- tun_attr_group
- tun_set_iff
- tun_get_iff
- set_offload
- tun_detach_filter
- tun_attach_filter
- tun_set_sndbuf
- tun_set_queue
- tun_set_ebpf
- tun_get_addr_len
- __tun_chr_ioctl
- tun_chr_ioctl
- tun_chr_compat_ioctl
- tun_chr_fasync
- tun_chr_open
- tun_chr_close
- tun_chr_show_fdinfo
- tun_fops
- tun_miscdev
- tun_default_link_ksettings
- tun_get_link_ksettings
- tun_set_link_ksettings
- tun_get_drvinfo
- tun_get_msglevel
- tun_set_msglevel
- tun_get_coalesce
- tun_set_coalesce
- tun_get_channels
- tun_ethtool_ops
- tun_queue_resize
- tun_device_event
- tun_notifier_block
- tun_init
- tun_cleanup
- tun_get_socket
Improve your Profiling and Debugging skills
Find out more