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mmc: core: Reset HPI enabled state during re-init and in case of errors
[linux/fpc-iii.git] / drivers / net / tun.c
blob005020042be946a23609dca3dfdcb589d60eff01
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use eth_random_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
43
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/sched/signal.h>
48 #include <linux/major.h>
49 #include <linux/slab.h>
50 #include <linux/poll.h>
51 #include <linux/fcntl.h>
52 #include <linux/init.h>
53 #include <linux/skbuff.h>
54 #include <linux/netdevice.h>
55 #include <linux/etherdevice.h>
56 #include <linux/miscdevice.h>
57 #include <linux/ethtool.h>
58 #include <linux/rtnetlink.h>
59 #include <linux/compat.h>
60 #include <linux/if.h>
61 #include <linux/if_arp.h>
62 #include <linux/if_ether.h>
63 #include <linux/if_tun.h>
64 #include <linux/if_vlan.h>
65 #include <linux/crc32.h>
66 #include <linux/nsproxy.h>
67 #include <linux/virtio_net.h>
68 #include <linux/rcupdate.h>
69 #include <net/net_namespace.h>
70 #include <net/netns/generic.h>
71 #include <net/rtnetlink.h>
72 #include <net/sock.h>
73 #include <net/xdp.h>
74 #include <linux/seq_file.h>
75 #include <linux/uio.h>
76 #include <linux/skb_array.h>
77 #include <linux/bpf.h>
78 #include <linux/bpf_trace.h>
79 #include <linux/mutex.h>
80
81 #include <linux/uaccess.h>
82 #include <linux/proc_fs.h>
83
84 static void tun_default_link_ksettings(struct net_device *dev,
85 struct ethtool_link_ksettings *cmd);
86
87 /* Uncomment to enable debugging */
88 /* #define TUN_DEBUG 1 */
89
90 #ifdef TUN_DEBUG
91 static int debug;
92
93 #define tun_debug(level, tun, fmt, args...) \
94 do { \
95 if (tun->debug) \
96 netdev_printk(level, tun->dev, fmt, ##args); \
97 } while (0)
98 #define DBG1(level, fmt, args...) \
99 do { \
100 if (debug == 2) \
101 printk(level fmt, ##args); \
102 } while (0)
103 #else
104 #define tun_debug(level, tun, fmt, args...) \
105 do { \
106 if (0) \
107 netdev_printk(level, tun->dev, fmt, ##args); \
108 } while (0)
109 #define DBG1(level, fmt, args...) \
110 do { \
111 if (0) \
112 printk(level fmt, ##args); \
113 } while (0)
114 #endif
115
116 #define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
117
118 /* TUN device flags */
119
120 /* IFF_ATTACH_QUEUE is never stored in device flags,
121 * overload it to mean fasync when stored there.
122 */
123 #define TUN_FASYNC IFF_ATTACH_QUEUE
124 /* High bits in flags field are unused. */
125 #define TUN_VNET_LE 0x80000000
126 #define TUN_VNET_BE 0x40000000
127
128 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
129 IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS)
130
131 #define GOODCOPY_LEN 128
132
133 #define FLT_EXACT_COUNT 8
134 struct tap_filter {
135 unsigned int count; /* Number of addrs. Zero means disabled */
136 u32 mask[2]; /* Mask of the hashed addrs */
137 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
138 };
139
140 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
141 * to max number of VCPUs in guest. */
142 #define MAX_TAP_QUEUES 256
143 #define MAX_TAP_FLOWS 4096
144
145 #define TUN_FLOW_EXPIRE (3 * HZ)
146
147 struct tun_pcpu_stats {
148 u64 rx_packets;
149 u64 rx_bytes;
150 u64 tx_packets;
151 u64 tx_bytes;
152 struct u64_stats_sync syncp;
153 u32 rx_dropped;
154 u32 tx_dropped;
155 u32 rx_frame_errors;
156 };
157
158 /* A tun_file connects an open character device to a tuntap netdevice. It
159 * also contains all socket related structures (except sock_fprog and tap_filter)
160 * to serve as one transmit queue for tuntap device. The sock_fprog and
161 * tap_filter were kept in tun_struct since they were used for filtering for the
162 * netdevice not for a specific queue (at least I didn't see the requirement for
163 * this).
164 *
165 * RCU usage:
166 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
167 * other can only be read while rcu_read_lock or rtnl_lock is held.
168 */
169 struct tun_file {
170 struct sock sk;
171 struct socket socket;
172 struct socket_wq wq;
173 struct tun_struct __rcu *tun;
174 struct fasync_struct *fasync;
175 /* only used for fasnyc */
176 unsigned int flags;
177 union {
178 u16 queue_index;
179 unsigned int ifindex;
180 };
181 struct napi_struct napi;
182 bool napi_enabled;
183 bool napi_frags_enabled;
184 struct mutex napi_mutex; /* Protects access to the above napi */
185 struct list_head next;
186 struct tun_struct *detached;
187 struct ptr_ring tx_ring;
188 struct xdp_rxq_info xdp_rxq;
189 };
190
191 struct tun_flow_entry {
192 struct hlist_node hash_link;
193 struct rcu_head rcu;
194 struct tun_struct *tun;
195
196 u32 rxhash;
197 u32 rps_rxhash;
198 int queue_index;
199 unsigned long updated;
200 };
201
202 #define TUN_NUM_FLOW_ENTRIES 1024
203 #define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1)
204
205 struct tun_prog {
206 struct rcu_head rcu;
207 struct bpf_prog *prog;
208 };
209
210 /* Since the socket were moved to tun_file, to preserve the behavior of persist
211 * device, socket filter, sndbuf and vnet header size were restore when the
212 * file were attached to a persist device.
213 */
214 struct tun_struct {
215 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
216 unsigned int numqueues;
217 unsigned int flags;
218 kuid_t owner;
219 kgid_t group;
220
221 struct net_device *dev;
222 netdev_features_t set_features;
223 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
224 NETIF_F_TSO6)
225
226 int align;
227 int vnet_hdr_sz;
228 int sndbuf;
229 struct tap_filter txflt;
230 struct sock_fprog fprog;
231 /* protected by rtnl lock */
232 bool filter_attached;
233 #ifdef TUN_DEBUG
234 int debug;
235 #endif
236 spinlock_t lock;
237 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
238 struct timer_list flow_gc_timer;
239 unsigned long ageing_time;
240 unsigned int numdisabled;
241 struct list_head disabled;
242 void *security;
243 u32 flow_count;
244 u32 rx_batched;
245 struct tun_pcpu_stats __percpu *pcpu_stats;
246 struct bpf_prog __rcu *xdp_prog;
247 struct tun_prog __rcu *steering_prog;
248 struct tun_prog __rcu *filter_prog;
249 struct ethtool_link_ksettings link_ksettings;
250 };
251
252 struct veth {
253 __be16 h_vlan_proto;
254 __be16 h_vlan_TCI;
255 };
256
257 bool tun_is_xdp_frame(void *ptr)
258 {
259 return (unsigned long)ptr & TUN_XDP_FLAG;
260 }
261 EXPORT_SYMBOL(tun_is_xdp_frame);
262
263 void *tun_xdp_to_ptr(void *ptr)
264 {
265 return (void *)((unsigned long)ptr | TUN_XDP_FLAG);
266 }
267 EXPORT_SYMBOL(tun_xdp_to_ptr);
268
269 void *tun_ptr_to_xdp(void *ptr)
270 {
271 return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
272 }
273 EXPORT_SYMBOL(tun_ptr_to_xdp);
274
275 static int tun_napi_receive(struct napi_struct *napi, int budget)
276 {
277 struct tun_file *tfile = container_of(napi, struct tun_file, napi);
278 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
279 struct sk_buff_head process_queue;
280 struct sk_buff *skb;
281 int received = 0;
282
283 __skb_queue_head_init(&process_queue);
284
285 spin_lock(&queue->lock);
286 skb_queue_splice_tail_init(queue, &process_queue);
287 spin_unlock(&queue->lock);
288
289 while (received < budget && (skb = __skb_dequeue(&process_queue))) {
290 napi_gro_receive(napi, skb);
291 ++received;
292 }
293
294 if (!skb_queue_empty(&process_queue)) {
295 spin_lock(&queue->lock);
296 skb_queue_splice(&process_queue, queue);
297 spin_unlock(&queue->lock);
298 }
299
300 return received;
301 }
302
303 static int tun_napi_poll(struct napi_struct *napi, int budget)
304 {
305 unsigned int received;
306
307 received = tun_napi_receive(napi, budget);
308
309 if (received < budget)
310 napi_complete_done(napi, received);
311
312 return received;
313 }
314
315 static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile,
316 bool napi_en, bool napi_frags)
317 {
318 tfile->napi_enabled = napi_en;
319 tfile->napi_frags_enabled = napi_en && napi_frags;
320 if (napi_en) {
321 netif_napi_add(tun->dev, &tfile->napi, tun_napi_poll,
322 NAPI_POLL_WEIGHT);
323 napi_enable(&tfile->napi);
324 }
325 }
326
327 static void tun_napi_disable(struct tun_file *tfile)
328 {
329 if (tfile->napi_enabled)
330 napi_disable(&tfile->napi);
331 }
332
333 static void tun_napi_del(struct tun_file *tfile)
334 {
335 if (tfile->napi_enabled)
336 netif_napi_del(&tfile->napi);
337 }
338
339 static bool tun_napi_frags_enabled(const struct tun_file *tfile)
340 {
341 return tfile->napi_frags_enabled;
342 }
343
344 #ifdef CONFIG_TUN_VNET_CROSS_LE
345 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
346 {
347 return tun->flags & TUN_VNET_BE ? false :
348 virtio_legacy_is_little_endian();
349 }
350
351 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
352 {
353 int be = !!(tun->flags & TUN_VNET_BE);
354
355 if (put_user(be, argp))
356 return -EFAULT;
357
358 return 0;
359 }
360
361 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
362 {
363 int be;
364
365 if (get_user(be, argp))
366 return -EFAULT;
367
368 if (be)
369 tun->flags |= TUN_VNET_BE;
370 else
371 tun->flags &= ~TUN_VNET_BE;
372
373 return 0;
374 }
375 #else
376 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
377 {
378 return virtio_legacy_is_little_endian();
379 }
380
381 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
382 {
383 return -EINVAL;
384 }
385
386 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
387 {
388 return -EINVAL;
389 }
390 #endif /* CONFIG_TUN_VNET_CROSS_LE */
391
392 static inline bool tun_is_little_endian(struct tun_struct *tun)
393 {
394 return tun->flags & TUN_VNET_LE ||
395 tun_legacy_is_little_endian(tun);
396 }
397
398 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
399 {
400 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
401 }
402
403 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
404 {
405 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
406 }
407
408 static inline u32 tun_hashfn(u32 rxhash)
409 {
410 return rxhash & TUN_MASK_FLOW_ENTRIES;
411 }
412
413 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
414 {
415 struct tun_flow_entry *e;
416
417 hlist_for_each_entry_rcu(e, head, hash_link) {
418 if (e->rxhash == rxhash)
419 return e;
420 }
421 return NULL;
422 }
423
424 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
425 struct hlist_head *head,
426 u32 rxhash, u16 queue_index)
427 {
428 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
429
430 if (e) {
431 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
432 rxhash, queue_index);
433 e->updated = jiffies;
434 e->rxhash = rxhash;
435 e->rps_rxhash = 0;
436 e->queue_index = queue_index;
437 e->tun = tun;
438 hlist_add_head_rcu(&e->hash_link, head);
439 ++tun->flow_count;
440 }
441 return e;
442 }
443
444 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
445 {
446 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
447 e->rxhash, e->queue_index);
448 hlist_del_rcu(&e->hash_link);
449 kfree_rcu(e, rcu);
450 --tun->flow_count;
451 }
452
453 static void tun_flow_flush(struct tun_struct *tun)
454 {
455 int i;
456
457 spin_lock_bh(&tun->lock);
458 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
459 struct tun_flow_entry *e;
460 struct hlist_node *n;
461
462 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
463 tun_flow_delete(tun, e);
464 }
465 spin_unlock_bh(&tun->lock);
466 }
467
468 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
469 {
470 int i;
471
472 spin_lock_bh(&tun->lock);
473 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
474 struct tun_flow_entry *e;
475 struct hlist_node *n;
476
477 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
478 if (e->queue_index == queue_index)
479 tun_flow_delete(tun, e);
480 }
481 }
482 spin_unlock_bh(&tun->lock);
483 }
484
485 static void tun_flow_cleanup(struct timer_list *t)
486 {
487 struct tun_struct *tun = from_timer(tun, t, flow_gc_timer);
488 unsigned long delay = tun->ageing_time;
489 unsigned long next_timer = jiffies + delay;
490 unsigned long count = 0;
491 int i;
492
493 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
494
495 spin_lock(&tun->lock);
496 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
497 struct tun_flow_entry *e;
498 struct hlist_node *n;
499
500 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
501 unsigned long this_timer;
502
503 this_timer = e->updated + delay;
504 if (time_before_eq(this_timer, jiffies)) {
505 tun_flow_delete(tun, e);
506 continue;
507 }
508 count++;
509 if (time_before(this_timer, next_timer))
510 next_timer = this_timer;
511 }
512 }
513
514 if (count)
515 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
516 spin_unlock(&tun->lock);
517 }
518
519 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
520 struct tun_file *tfile)
521 {
522 struct hlist_head *head;
523 struct tun_flow_entry *e;
524 unsigned long delay = tun->ageing_time;
525 u16 queue_index = tfile->queue_index;
526
527 if (!rxhash)
528 return;
529 else
530 head = &tun->flows[tun_hashfn(rxhash)];
531
532 rcu_read_lock();
533
534 e = tun_flow_find(head, rxhash);
535 if (likely(e)) {
536 /* TODO: keep queueing to old queue until it's empty? */
537 e->queue_index = queue_index;
538 e->updated = jiffies;
539 sock_rps_record_flow_hash(e->rps_rxhash);
540 } else {
541 spin_lock_bh(&tun->lock);
542 if (!tun_flow_find(head, rxhash) &&
543 tun->flow_count < MAX_TAP_FLOWS)
544 tun_flow_create(tun, head, rxhash, queue_index);
545
546 if (!timer_pending(&tun->flow_gc_timer))
547 mod_timer(&tun->flow_gc_timer,
548 round_jiffies_up(jiffies + delay));
549 spin_unlock_bh(&tun->lock);
550 }
551
552 rcu_read_unlock();
553 }
554
555 /**
556 * Save the hash received in the stack receive path and update the
557 * flow_hash table accordingly.
558 */
559 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
560 {
561 if (unlikely(e->rps_rxhash != hash))
562 e->rps_rxhash = hash;
563 }
564
565 /* We try to identify a flow through its rxhash. The reason that
566 * we do not check rxq no. is because some cards(e.g 82599), chooses
567 * the rxq based on the txq where the last packet of the flow comes. As
568 * the userspace application move between processors, we may get a
569 * different rxq no. here.
570 */
571 static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb)
572 {
573 struct tun_flow_entry *e;
574 u32 txq = 0;
575 u32 numqueues = 0;
576
577 numqueues = READ_ONCE(tun->numqueues);
578
579 txq = __skb_get_hash_symmetric(skb);
580 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
581 if (e) {
582 tun_flow_save_rps_rxhash(e, txq);
583 txq = e->queue_index;
584 } else {
585 /* use multiply and shift instead of expensive divide */
586 txq = ((u64)txq * numqueues) >> 32;
587 }
588
589 return txq;
590 }
591
592 static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb)
593 {
594 struct tun_prog *prog;
595 u16 ret = 0;
596
597 prog = rcu_dereference(tun->steering_prog);
598 if (prog)
599 ret = bpf_prog_run_clear_cb(prog->prog, skb);
600
601 return ret % tun->numqueues;
602 }
603
604 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
605 struct net_device *sb_dev,
606 select_queue_fallback_t fallback)
607 {
608 struct tun_struct *tun = netdev_priv(dev);
609 u16 ret;
610
611 rcu_read_lock();
612 if (rcu_dereference(tun->steering_prog))
613 ret = tun_ebpf_select_queue(tun, skb);
614 else
615 ret = tun_automq_select_queue(tun, skb);
616 rcu_read_unlock();
617
618 return ret;
619 }
620
621 static inline bool tun_not_capable(struct tun_struct *tun)
622 {
623 const struct cred *cred = current_cred();
624 struct net *net = dev_net(tun->dev);
625
626 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
627 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
628 !ns_capable(net->user_ns, CAP_NET_ADMIN);
629 }
630
631 static void tun_set_real_num_queues(struct tun_struct *tun)
632 {
633 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
634 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
635 }
636
637 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
638 {
639 tfile->detached = tun;
640 list_add_tail(&tfile->next, &tun->disabled);
641 ++tun->numdisabled;
642 }
643
644 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
645 {
646 struct tun_struct *tun = tfile->detached;
647
648 tfile->detached = NULL;
649 list_del_init(&tfile->next);
650 --tun->numdisabled;
651 return tun;
652 }
653
654 void tun_ptr_free(void *ptr)
655 {
656 if (!ptr)
657 return;
658 if (tun_is_xdp_frame(ptr)) {
659 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
660
661 xdp_return_frame(xdpf);
662 } else {
663 __skb_array_destroy_skb(ptr);
664 }
665 }
666 EXPORT_SYMBOL_GPL(tun_ptr_free);
667
668 static void tun_queue_purge(struct tun_file *tfile)
669 {
670 void *ptr;
671
672 while ((ptr = ptr_ring_consume(&tfile->tx_ring)) != NULL)
673 tun_ptr_free(ptr);
674
675 skb_queue_purge(&tfile->sk.sk_write_queue);
676 skb_queue_purge(&tfile->sk.sk_error_queue);
677 }
678
679 static void __tun_detach(struct tun_file *tfile, bool clean)
680 {
681 struct tun_file *ntfile;
682 struct tun_struct *tun;
683
684 tun = rtnl_dereference(tfile->tun);
685
686 if (tun && clean) {
687 tun_napi_disable(tfile);
688 tun_napi_del(tfile);
689 }
690
691 if (tun && !tfile->detached) {
692 u16 index = tfile->queue_index;
693 BUG_ON(index >= tun->numqueues);
694
695 rcu_assign_pointer(tun->tfiles[index],
696 tun->tfiles[tun->numqueues - 1]);
697 ntfile = rtnl_dereference(tun->tfiles[index]);
698 ntfile->queue_index = index;
699
700 --tun->numqueues;
701 if (clean) {
702 RCU_INIT_POINTER(tfile->tun, NULL);
703 sock_put(&tfile->sk);
704 } else
705 tun_disable_queue(tun, tfile);
706
707 synchronize_net();
708 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
709 /* Drop read queue */
710 tun_queue_purge(tfile);
711 tun_set_real_num_queues(tun);
712 } else if (tfile->detached && clean) {
713 tun = tun_enable_queue(tfile);
714 sock_put(&tfile->sk);
715 }
716
717 if (clean) {
718 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
719 netif_carrier_off(tun->dev);
720
721 if (!(tun->flags & IFF_PERSIST) &&
722 tun->dev->reg_state == NETREG_REGISTERED)
723 unregister_netdevice(tun->dev);
724 }
725 if (tun)
726 xdp_rxq_info_unreg(&tfile->xdp_rxq);
727 ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
728 sock_put(&tfile->sk);
729 }
730 }
731
732 static void tun_detach(struct tun_file *tfile, bool clean)
733 {
734 struct tun_struct *tun;
735 struct net_device *dev;
736
737 rtnl_lock();
738 tun = rtnl_dereference(tfile->tun);
739 dev = tun ? tun->dev : NULL;
740 __tun_detach(tfile, clean);
741 if (dev)
742 netdev_state_change(dev);
743 rtnl_unlock();
744 }
745
746 static void tun_detach_all(struct net_device *dev)
747 {
748 struct tun_struct *tun = netdev_priv(dev);
749 struct tun_file *tfile, *tmp;
750 int i, n = tun->numqueues;
751
752 for (i = 0; i < n; i++) {
753 tfile = rtnl_dereference(tun->tfiles[i]);
754 BUG_ON(!tfile);
755 tun_napi_disable(tfile);
756 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
757 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
758 RCU_INIT_POINTER(tfile->tun, NULL);
759 --tun->numqueues;
760 }
761 list_for_each_entry(tfile, &tun->disabled, next) {
762 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
763 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
764 RCU_INIT_POINTER(tfile->tun, NULL);
765 }
766 BUG_ON(tun->numqueues != 0);
767
768 synchronize_net();
769 for (i = 0; i < n; i++) {
770 tfile = rtnl_dereference(tun->tfiles[i]);
771 tun_napi_del(tfile);
772 /* Drop read queue */
773 tun_queue_purge(tfile);
774 xdp_rxq_info_unreg(&tfile->xdp_rxq);
775 sock_put(&tfile->sk);
776 }
777 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
778 tun_enable_queue(tfile);
779 tun_queue_purge(tfile);
780 xdp_rxq_info_unreg(&tfile->xdp_rxq);
781 sock_put(&tfile->sk);
782 }
783 BUG_ON(tun->numdisabled != 0);
784
785 if (tun->flags & IFF_PERSIST)
786 module_put(THIS_MODULE);
787 }
788
789 static int tun_attach(struct tun_struct *tun, struct file *file,
790 bool skip_filter, bool napi, bool napi_frags)
791 {
792 struct tun_file *tfile = file->private_data;
793 struct net_device *dev = tun->dev;
794 int err;
795
796 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
797 if (err < 0)
798 goto out;
799
800 err = -EINVAL;
801 if (rtnl_dereference(tfile->tun) && !tfile->detached)
802 goto out;
803
804 err = -EBUSY;
805 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
806 goto out;
807
808 err = -E2BIG;
809 if (!tfile->detached &&
810 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
811 goto out;
812
813 err = 0;
814
815 /* Re-attach the filter to persist device */
816 if (!skip_filter && (tun->filter_attached == true)) {
817 lock_sock(tfile->socket.sk);
818 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
819 release_sock(tfile->socket.sk);
820 if (!err)
821 goto out;
822 }
823
824 if (!tfile->detached &&
825 ptr_ring_resize(&tfile->tx_ring, dev->tx_queue_len,
826 GFP_KERNEL, tun_ptr_free)) {
827 err = -ENOMEM;
828 goto out;
829 }
830
831 tfile->queue_index = tun->numqueues;
832 tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
833
834 if (tfile->detached) {
835 /* Re-attach detached tfile, updating XDP queue_index */
836 WARN_ON(!xdp_rxq_info_is_reg(&tfile->xdp_rxq));
837
838 if (tfile->xdp_rxq.queue_index != tfile->queue_index)
839 tfile->xdp_rxq.queue_index = tfile->queue_index;
840 } else {
841 /* Setup XDP RX-queue info, for new tfile getting attached */
842 err = xdp_rxq_info_reg(&tfile->xdp_rxq,
843 tun->dev, tfile->queue_index);
844 if (err < 0)
845 goto out;
846 err = xdp_rxq_info_reg_mem_model(&tfile->xdp_rxq,
847 MEM_TYPE_PAGE_SHARED, NULL);
848 if (err < 0) {
849 xdp_rxq_info_unreg(&tfile->xdp_rxq);
850 goto out;
851 }
852 err = 0;
853 }
854
855 rcu_assign_pointer(tfile->tun, tun);
856 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
857 tun->numqueues++;
858
859 if (tfile->detached) {
860 tun_enable_queue(tfile);
861 } else {
862 sock_hold(&tfile->sk);
863 tun_napi_init(tun, tfile, napi, napi_frags);
864 }
865
866 if (rtnl_dereference(tun->xdp_prog))
867 sock_set_flag(&tfile->sk, SOCK_XDP);
868
869 tun_set_real_num_queues(tun);
870
871 /* device is allowed to go away first, so no need to hold extra
872 * refcnt.
873 */
874
875 out:
876 return err;
877 }
878
879 static struct tun_struct *tun_get(struct tun_file *tfile)
880 {
881 struct tun_struct *tun;
882
883 rcu_read_lock();
884 tun = rcu_dereference(tfile->tun);
885 if (tun)
886 dev_hold(tun->dev);
887 rcu_read_unlock();
888
889 return tun;
890 }
891
892 static void tun_put(struct tun_struct *tun)
893 {
894 dev_put(tun->dev);
895 }
896
897 /* TAP filtering */
898 static void addr_hash_set(u32 *mask, const u8 *addr)
899 {
900 int n = ether_crc(ETH_ALEN, addr) >> 26;
901 mask[n >> 5] |= (1 << (n & 31));
902 }
903
904 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
905 {
906 int n = ether_crc(ETH_ALEN, addr) >> 26;
907 return mask[n >> 5] & (1 << (n & 31));
908 }
909
910 static int update_filter(struct tap_filter *filter, void __user *arg)
911 {
912 struct { u8 u[ETH_ALEN]; } *addr;
913 struct tun_filter uf;
914 int err, alen, n, nexact;
915
916 if (copy_from_user(&uf, arg, sizeof(uf)))
917 return -EFAULT;
918
919 if (!uf.count) {
920 /* Disabled */
921 filter->count = 0;
922 return 0;
923 }
924
925 alen = ETH_ALEN * uf.count;
926 addr = memdup_user(arg + sizeof(uf), alen);
927 if (IS_ERR(addr))
928 return PTR_ERR(addr);
929
930 /* The filter is updated without holding any locks. Which is
931 * perfectly safe. We disable it first and in the worst
932 * case we'll accept a few undesired packets. */
933 filter->count = 0;
934 wmb();
935
936 /* Use first set of addresses as an exact filter */
937 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
938 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
939
940 nexact = n;
941
942 /* Remaining multicast addresses are hashed,
943 * unicast will leave the filter disabled. */
944 memset(filter->mask, 0, sizeof(filter->mask));
945 for (; n < uf.count; n++) {
946 if (!is_multicast_ether_addr(addr[n].u)) {
947 err = 0; /* no filter */
948 goto free_addr;
949 }
950 addr_hash_set(filter->mask, addr[n].u);
951 }
952
953 /* For ALLMULTI just set the mask to all ones.
954 * This overrides the mask populated above. */
955 if ((uf.flags & TUN_FLT_ALLMULTI))
956 memset(filter->mask, ~0, sizeof(filter->mask));
957
958 /* Now enable the filter */
959 wmb();
960 filter->count = nexact;
961
962 /* Return the number of exact filters */
963 err = nexact;
964 free_addr:
965 kfree(addr);
966 return err;
967 }
968
969 /* Returns: 0 - drop, !=0 - accept */
970 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
971 {
972 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
973 * at this point. */
974 struct ethhdr *eh = (struct ethhdr *) skb->data;
975 int i;
976
977 /* Exact match */
978 for (i = 0; i < filter->count; i++)
979 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
980 return 1;
981
982 /* Inexact match (multicast only) */
983 if (is_multicast_ether_addr(eh->h_dest))
984 return addr_hash_test(filter->mask, eh->h_dest);
985
986 return 0;
987 }
988
989 /*
990 * Checks whether the packet is accepted or not.
991 * Returns: 0 - drop, !=0 - accept
992 */
993 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
994 {
995 if (!filter->count)
996 return 1;
997
998 return run_filter(filter, skb);
999 }
1000
1001 /* Network device part of the driver */
1002
1003 static const struct ethtool_ops tun_ethtool_ops;
1004
1005 /* Net device detach from fd. */
1006 static void tun_net_uninit(struct net_device *dev)
1007 {
1008 tun_detach_all(dev);
1009 }
1010
1011 /* Net device open. */
1012 static int tun_net_open(struct net_device *dev)
1013 {
1014 struct tun_struct *tun = netdev_priv(dev);
1015 int i;
1016
1017 netif_tx_start_all_queues(dev);
1018
1019 for (i = 0; i < tun->numqueues; i++) {
1020 struct tun_file *tfile;
1021
1022 tfile = rtnl_dereference(tun->tfiles[i]);
1023 tfile->socket.sk->sk_write_space(tfile->socket.sk);
1024 }
1025
1026 return 0;
1027 }
1028
1029 /* Net device close. */
1030 static int tun_net_close(struct net_device *dev)
1031 {
1032 netif_tx_stop_all_queues(dev);
1033 return 0;
1034 }
1035
1036 /* Net device start xmit */
1037 static void tun_automq_xmit(struct tun_struct *tun, struct sk_buff *skb)
1038 {
1039 #ifdef CONFIG_RPS
1040 if (tun->numqueues == 1 && static_key_false(&rps_needed)) {
1041 /* Select queue was not called for the skbuff, so we extract the
1042 * RPS hash and save it into the flow_table here.
1043 */
1044 struct tun_flow_entry *e;
1045 __u32 rxhash;
1046
1047 rxhash = __skb_get_hash_symmetric(skb);
1048 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)], rxhash);
1049 if (e)
1050 tun_flow_save_rps_rxhash(e, rxhash);
1051 }
1052 #endif
1053 }
1054
1055 static unsigned int run_ebpf_filter(struct tun_struct *tun,
1056 struct sk_buff *skb,
1057 int len)
1058 {
1059 struct tun_prog *prog = rcu_dereference(tun->filter_prog);
1060
1061 if (prog)
1062 len = bpf_prog_run_clear_cb(prog->prog, skb);
1063
1064 return len;
1065 }
1066
1067 /* Net device start xmit */
1068 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
1069 {
1070 struct tun_struct *tun = netdev_priv(dev);
1071 int txq = skb->queue_mapping;
1072 struct tun_file *tfile;
1073 int len = skb->len;
1074
1075 rcu_read_lock();
1076 tfile = rcu_dereference(tun->tfiles[txq]);
1077
1078 /* Drop packet if interface is not attached */
1079 if (txq >= tun->numqueues)
1080 goto drop;
1081
1082 if (!rcu_dereference(tun->steering_prog))
1083 tun_automq_xmit(tun, skb);
1084
1085 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
1086
1087 BUG_ON(!tfile);
1088
1089 /* Drop if the filter does not like it.
1090 * This is a noop if the filter is disabled.
1091 * Filter can be enabled only for the TAP devices. */
1092 if (!check_filter(&tun->txflt, skb))
1093 goto drop;
1094
1095 if (tfile->socket.sk->sk_filter &&
1096 sk_filter(tfile->socket.sk, skb))
1097 goto drop;
1098
1099 len = run_ebpf_filter(tun, skb, len);
1100 if (len == 0 || pskb_trim(skb, len))
1101 goto drop;
1102
1103 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
1104 goto drop;
1105
1106 skb_tx_timestamp(skb);
1107
1108 /* Orphan the skb - required as we might hang on to it
1109 * for indefinite time.
1110 */
1111 skb_orphan(skb);
1112
1113 nf_reset(skb);
1114
1115 if (ptr_ring_produce(&tfile->tx_ring, skb))
1116 goto drop;
1117
1118 /* Notify and wake up reader process */
1119 if (tfile->flags & TUN_FASYNC)
1120 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
1121 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
1122
1123 rcu_read_unlock();
1124 return NETDEV_TX_OK;
1125
1126 drop:
1127 this_cpu_inc(tun->pcpu_stats->tx_dropped);
1128 skb_tx_error(skb);
1129 kfree_skb(skb);
1130 rcu_read_unlock();
1131 return NET_XMIT_DROP;
1132 }
1133
1134 static void tun_net_mclist(struct net_device *dev)
1135 {
1136 /*
1137 * This callback is supposed to deal with mc filter in
1138 * _rx_ path and has nothing to do with the _tx_ path.
1139 * In rx path we always accept everything userspace gives us.
1140 */
1141 }
1142
1143 static netdev_features_t tun_net_fix_features(struct net_device *dev,
1144 netdev_features_t features)
1145 {
1146 struct tun_struct *tun = netdev_priv(dev);
1147
1148 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
1149 }
1150
1151 static void tun_set_headroom(struct net_device *dev, int new_hr)
1152 {
1153 struct tun_struct *tun = netdev_priv(dev);
1154
1155 if (new_hr < NET_SKB_PAD)
1156 new_hr = NET_SKB_PAD;
1157
1158 tun->align = new_hr;
1159 }
1160
1161 static void
1162 tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
1163 {
1164 u32 rx_dropped = 0, tx_dropped = 0, rx_frame_errors = 0;
1165 struct tun_struct *tun = netdev_priv(dev);
1166 struct tun_pcpu_stats *p;
1167 int i;
1168
1169 for_each_possible_cpu(i) {
1170 u64 rxpackets, rxbytes, txpackets, txbytes;
1171 unsigned int start;
1172
1173 p = per_cpu_ptr(tun->pcpu_stats, i);
1174 do {
1175 start = u64_stats_fetch_begin(&p->syncp);
1176 rxpackets = p->rx_packets;
1177 rxbytes = p->rx_bytes;
1178 txpackets = p->tx_packets;
1179 txbytes = p->tx_bytes;
1180 } while (u64_stats_fetch_retry(&p->syncp, start));
1181
1182 stats->rx_packets += rxpackets;
1183 stats->rx_bytes += rxbytes;
1184 stats->tx_packets += txpackets;
1185 stats->tx_bytes += txbytes;
1186
1187 /* u32 counters */
1188 rx_dropped += p->rx_dropped;
1189 rx_frame_errors += p->rx_frame_errors;
1190 tx_dropped += p->tx_dropped;
1191 }
1192 stats->rx_dropped = rx_dropped;
1193 stats->rx_frame_errors = rx_frame_errors;
1194 stats->tx_dropped = tx_dropped;
1195 }
1196
1197 static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1198 struct netlink_ext_ack *extack)
1199 {
1200 struct tun_struct *tun = netdev_priv(dev);
1201 struct tun_file *tfile;
1202 struct bpf_prog *old_prog;
1203 int i;
1204
1205 old_prog = rtnl_dereference(tun->xdp_prog);
1206 rcu_assign_pointer(tun->xdp_prog, prog);
1207 if (old_prog)
1208 bpf_prog_put(old_prog);
1209
1210 for (i = 0; i < tun->numqueues; i++) {
1211 tfile = rtnl_dereference(tun->tfiles[i]);
1212 if (prog)
1213 sock_set_flag(&tfile->sk, SOCK_XDP);
1214 else
1215 sock_reset_flag(&tfile->sk, SOCK_XDP);
1216 }
1217 list_for_each_entry(tfile, &tun->disabled, next) {
1218 if (prog)
1219 sock_set_flag(&tfile->sk, SOCK_XDP);
1220 else
1221 sock_reset_flag(&tfile->sk, SOCK_XDP);
1222 }
1223
1224 return 0;
1225 }
1226
1227 static u32 tun_xdp_query(struct net_device *dev)
1228 {
1229 struct tun_struct *tun = netdev_priv(dev);
1230 const struct bpf_prog *xdp_prog;
1231
1232 xdp_prog = rtnl_dereference(tun->xdp_prog);
1233 if (xdp_prog)
1234 return xdp_prog->aux->id;
1235
1236 return 0;
1237 }
1238
1239 static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1240 {
1241 switch (xdp->command) {
1242 case XDP_SETUP_PROG:
1243 return tun_xdp_set(dev, xdp->prog, xdp->extack);
1244 case XDP_QUERY_PROG:
1245 xdp->prog_id = tun_xdp_query(dev);
1246 return 0;
1247 default:
1248 return -EINVAL;
1249 }
1250 }
1251
1252 static const struct net_device_ops tun_netdev_ops = {
1253 .ndo_uninit = tun_net_uninit,
1254 .ndo_open = tun_net_open,
1255 .ndo_stop = tun_net_close,
1256 .ndo_start_xmit = tun_net_xmit,
1257 .ndo_fix_features = tun_net_fix_features,
1258 .ndo_select_queue = tun_select_queue,
1259 .ndo_set_rx_headroom = tun_set_headroom,
1260 .ndo_get_stats64 = tun_net_get_stats64,
1261 };
1262
1263 static void __tun_xdp_flush_tfile(struct tun_file *tfile)
1264 {
1265 /* Notify and wake up reader process */
1266 if (tfile->flags & TUN_FASYNC)
1267 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
1268 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
1269 }
1270
1271 static int tun_xdp_xmit(struct net_device *dev, int n,
1272 struct xdp_frame **frames, u32 flags)
1273 {
1274 struct tun_struct *tun = netdev_priv(dev);
1275 struct tun_file *tfile;
1276 u32 numqueues;
1277 int drops = 0;
1278 int cnt = n;
1279 int i;
1280
1281 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
1282 return -EINVAL;
1283
1284 rcu_read_lock();
1285
1286 numqueues = READ_ONCE(tun->numqueues);
1287 if (!numqueues) {
1288 rcu_read_unlock();
1289 return -ENXIO; /* Caller will free/return all frames */
1290 }
1291
1292 tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
1293 numqueues]);
1294
1295 spin_lock(&tfile->tx_ring.producer_lock);
1296 for (i = 0; i < n; i++) {
1297 struct xdp_frame *xdp = frames[i];
1298 /* Encode the XDP flag into lowest bit for consumer to differ
1299 * XDP buffer from sk_buff.
1300 */
1301 void *frame = tun_xdp_to_ptr(xdp);
1302
1303 if (__ptr_ring_produce(&tfile->tx_ring, frame)) {
1304 this_cpu_inc(tun->pcpu_stats->tx_dropped);
1305 xdp_return_frame_rx_napi(xdp);
1306 drops++;
1307 }
1308 }
1309 spin_unlock(&tfile->tx_ring.producer_lock);
1310
1311 if (flags & XDP_XMIT_FLUSH)
1312 __tun_xdp_flush_tfile(tfile);
1313
1314 rcu_read_unlock();
1315 return cnt - drops;
1316 }
1317
1318 static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
1319 {
1320 struct xdp_frame *frame = convert_to_xdp_frame(xdp);
1321
1322 if (unlikely(!frame))
1323 return -EOVERFLOW;
1324
1325 return tun_xdp_xmit(dev, 1, &frame, XDP_XMIT_FLUSH);
1326 }
1327
1328 static const struct net_device_ops tap_netdev_ops = {
1329 .ndo_uninit = tun_net_uninit,
1330 .ndo_open = tun_net_open,
1331 .ndo_stop = tun_net_close,
1332 .ndo_start_xmit = tun_net_xmit,
1333 .ndo_fix_features = tun_net_fix_features,
1334 .ndo_set_rx_mode = tun_net_mclist,
1335 .ndo_set_mac_address = eth_mac_addr,
1336 .ndo_validate_addr = eth_validate_addr,
1337 .ndo_select_queue = tun_select_queue,
1338 .ndo_features_check = passthru_features_check,
1339 .ndo_set_rx_headroom = tun_set_headroom,
1340 .ndo_get_stats64 = tun_net_get_stats64,
1341 .ndo_bpf = tun_xdp,
1342 .ndo_xdp_xmit = tun_xdp_xmit,
1343 };
1344
1345 static void tun_flow_init(struct tun_struct *tun)
1346 {
1347 int i;
1348
1349 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
1350 INIT_HLIST_HEAD(&tun->flows[i]);
1351
1352 tun->ageing_time = TUN_FLOW_EXPIRE;
1353 timer_setup(&tun->flow_gc_timer, tun_flow_cleanup, 0);
1354 mod_timer(&tun->flow_gc_timer,
1355 round_jiffies_up(jiffies + tun->ageing_time));
1356 }
1357
1358 static void tun_flow_uninit(struct tun_struct *tun)
1359 {
1360 del_timer_sync(&tun->flow_gc_timer);
1361 tun_flow_flush(tun);
1362 }
1363
1364 #define MIN_MTU 68
1365 #define MAX_MTU 65535
1366
1367 /* Initialize net device. */
1368 static void tun_net_init(struct net_device *dev)
1369 {
1370 struct tun_struct *tun = netdev_priv(dev);
1371
1372 switch (tun->flags & TUN_TYPE_MASK) {
1373 case IFF_TUN:
1374 dev->netdev_ops = &tun_netdev_ops;
1375
1376 /* Point-to-Point TUN Device */
1377 dev->hard_header_len = 0;
1378 dev->addr_len = 0;
1379 dev->mtu = 1500;
1380
1381 /* Zero header length */
1382 dev->type = ARPHRD_NONE;
1383 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1384 break;
1385
1386 case IFF_TAP:
1387 dev->netdev_ops = &tap_netdev_ops;
1388 /* Ethernet TAP Device */
1389 ether_setup(dev);
1390 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1391 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1392
1393 eth_hw_addr_random(dev);
1394
1395 break;
1396 }
1397
1398 dev->min_mtu = MIN_MTU;
1399 dev->max_mtu = MAX_MTU - dev->hard_header_len;
1400 }
1401
1402 static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile)
1403 {
1404 struct sock *sk = tfile->socket.sk;
1405
1406 return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
1407 }
1408
1409 /* Character device part */
1410
1411 /* Poll */
1412 static __poll_t tun_chr_poll(struct file *file, poll_table *wait)
1413 {
1414 struct tun_file *tfile = file->private_data;
1415 struct tun_struct *tun = tun_get(tfile);
1416 struct sock *sk;
1417 __poll_t mask = 0;
1418
1419 if (!tun)
1420 return EPOLLERR;
1421
1422 sk = tfile->socket.sk;
1423
1424 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
1425
1426 poll_wait(file, sk_sleep(sk), wait);
1427
1428 if (!ptr_ring_empty(&tfile->tx_ring))
1429 mask |= EPOLLIN | EPOLLRDNORM;
1430
1431 /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
1432 * guarantee EPOLLOUT to be raised by either here or
1433 * tun_sock_write_space(). Then process could get notification
1434 * after it writes to a down device and meets -EIO.
1435 */
1436 if (tun_sock_writeable(tun, tfile) ||
1437 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1438 tun_sock_writeable(tun, tfile)))
1439 mask |= EPOLLOUT | EPOLLWRNORM;
1440
1441 if (tun->dev->reg_state != NETREG_REGISTERED)
1442 mask = EPOLLERR;
1443
1444 tun_put(tun);
1445 return mask;
1446 }
1447
1448 static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile,
1449 size_t len,
1450 const struct iov_iter *it)
1451 {
1452 struct sk_buff *skb;
1453 size_t linear;
1454 int err;
1455 int i;
1456
1457 if (it->nr_segs > MAX_SKB_FRAGS + 1)
1458 return ERR_PTR(-ENOMEM);
1459
1460 local_bh_disable();
1461 skb = napi_get_frags(&tfile->napi);
1462 local_bh_enable();
1463 if (!skb)
1464 return ERR_PTR(-ENOMEM);
1465
1466 linear = iov_iter_single_seg_count(it);
1467 err = __skb_grow(skb, linear);
1468 if (err)
1469 goto free;
1470
1471 skb->len = len;
1472 skb->data_len = len - linear;
1473 skb->truesize += skb->data_len;
1474
1475 for (i = 1; i < it->nr_segs; i++) {
1476 struct page_frag *pfrag = &current->task_frag;
1477 size_t fragsz = it->iov[i].iov_len;
1478
1479 if (fragsz == 0 || fragsz > PAGE_SIZE) {
1480 err = -EINVAL;
1481 goto free;
1482 }
1483
1484 if (!skb_page_frag_refill(fragsz, pfrag, GFP_KERNEL)) {
1485 err = -ENOMEM;
1486 goto free;
1487 }
1488
1489 skb_fill_page_desc(skb, i - 1, pfrag->page,
1490 pfrag->offset, fragsz);
1491 page_ref_inc(pfrag->page);
1492 pfrag->offset += fragsz;
1493 }
1494
1495 return skb;
1496 free:
1497 /* frees skb and all frags allocated with napi_alloc_frag() */
1498 napi_free_frags(&tfile->napi);
1499 return ERR_PTR(err);
1500 }
1501
1502 /* prepad is the amount to reserve at front. len is length after that.
1503 * linear is a hint as to how much to copy (usually headers). */
1504 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1505 size_t prepad, size_t len,
1506 size_t linear, int noblock)
1507 {
1508 struct sock *sk = tfile->socket.sk;
1509 struct sk_buff *skb;
1510 int err;
1511
1512 /* Under a page? Don't bother with paged skb. */
1513 if (prepad + len < PAGE_SIZE || !linear)
1514 linear = len;
1515
1516 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1517 &err, 0);
1518 if (!skb)
1519 return ERR_PTR(err);
1520
1521 skb_reserve(skb, prepad);
1522 skb_put(skb, linear);
1523 skb->data_len = len - linear;
1524 skb->len += len - linear;
1525
1526 return skb;
1527 }
1528
1529 static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,
1530 struct sk_buff *skb, int more)
1531 {
1532 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1533 struct sk_buff_head process_queue;
1534 u32 rx_batched = tun->rx_batched;
1535 bool rcv = false;
1536
1537 if (!rx_batched || (!more && skb_queue_empty(queue))) {
1538 local_bh_disable();
1539 skb_record_rx_queue(skb, tfile->queue_index);
1540 netif_receive_skb(skb);
1541 local_bh_enable();
1542 return;
1543 }
1544
1545 spin_lock(&queue->lock);
1546 if (!more || skb_queue_len(queue) == rx_batched) {
1547 __skb_queue_head_init(&process_queue);
1548 skb_queue_splice_tail_init(queue, &process_queue);
1549 rcv = true;
1550 } else {
1551 __skb_queue_tail(queue, skb);
1552 }
1553 spin_unlock(&queue->lock);
1554
1555 if (rcv) {
1556 struct sk_buff *nskb;
1557
1558 local_bh_disable();
1559 while ((nskb = __skb_dequeue(&process_queue))) {
1560 skb_record_rx_queue(nskb, tfile->queue_index);
1561 netif_receive_skb(nskb);
1562 }
1563 skb_record_rx_queue(skb, tfile->queue_index);
1564 netif_receive_skb(skb);
1565 local_bh_enable();
1566 }
1567 }
1568
1569 static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
1570 int len, int noblock, bool zerocopy)
1571 {
1572 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
1573 return false;
1574
1575 if (tfile->socket.sk->sk_sndbuf != INT_MAX)
1576 return false;
1577
1578 if (!noblock)
1579 return false;
1580
1581 if (zerocopy)
1582 return false;
1583
1584 if (SKB_DATA_ALIGN(len + TUN_RX_PAD) +
1585 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
1586 return false;
1587
1588 return true;
1589 }
1590
1591 static struct sk_buff *__tun_build_skb(struct page_frag *alloc_frag, char *buf,
1592 int buflen, int len, int pad)
1593 {
1594 struct sk_buff *skb = build_skb(buf, buflen);
1595
1596 if (!skb)
1597 return ERR_PTR(-ENOMEM);
1598
1599 skb_reserve(skb, pad);
1600 skb_put(skb, len);
1601
1602 get_page(alloc_frag->page);
1603 alloc_frag->offset += buflen;
1604
1605 return skb;
1606 }
1607
1608 static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog,
1609 struct xdp_buff *xdp, u32 act)
1610 {
1611 int err;
1612
1613 switch (act) {
1614 case XDP_REDIRECT:
1615 err = xdp_do_redirect(tun->dev, xdp, xdp_prog);
1616 if (err)
1617 return err;
1618 break;
1619 case XDP_TX:
1620 err = tun_xdp_tx(tun->dev, xdp);
1621 if (err < 0)
1622 return err;
1623 break;
1624 case XDP_PASS:
1625 break;
1626 default:
1627 bpf_warn_invalid_xdp_action(act);
1628 /* fall through */
1629 case XDP_ABORTED:
1630 trace_xdp_exception(tun->dev, xdp_prog, act);
1631 /* fall through */
1632 case XDP_DROP:
1633 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1634 break;
1635 }
1636
1637 return act;
1638 }
1639
1640 static struct sk_buff *tun_build_skb(struct tun_struct *tun,
1641 struct tun_file *tfile,
1642 struct iov_iter *from,
1643 struct virtio_net_hdr *hdr,
1644 int len, int *skb_xdp)
1645 {
1646 struct page_frag *alloc_frag = &current->task_frag;
1647 struct bpf_prog *xdp_prog;
1648 int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1649 char *buf;
1650 size_t copied;
1651 int pad = TUN_RX_PAD;
1652 int err = 0;
1653
1654 rcu_read_lock();
1655 xdp_prog = rcu_dereference(tun->xdp_prog);
1656 if (xdp_prog)
1657 pad += XDP_PACKET_HEADROOM;
1658 buflen += SKB_DATA_ALIGN(len + pad);
1659 rcu_read_unlock();
1660
1661 alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
1662 if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
1663 return ERR_PTR(-ENOMEM);
1664
1665 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1666 copied = copy_page_from_iter(alloc_frag->page,
1667 alloc_frag->offset + pad,
1668 len, from);
1669 if (copied != len)
1670 return ERR_PTR(-EFAULT);
1671
1672 /* There's a small window that XDP may be set after the check
1673 * of xdp_prog above, this should be rare and for simplicity
1674 * we do XDP on skb in case the headroom is not enough.
1675 */
1676 if (hdr->gso_type || !xdp_prog) {
1677 *skb_xdp = 1;
1678 return __tun_build_skb(alloc_frag, buf, buflen, len, pad);
1679 }
1680
1681 *skb_xdp = 0;
1682
1683 local_bh_disable();
1684 rcu_read_lock();
1685 xdp_prog = rcu_dereference(tun->xdp_prog);
1686 if (xdp_prog) {
1687 struct xdp_buff xdp;
1688 u32 act;
1689
1690 xdp.data_hard_start = buf;
1691 xdp.data = buf + pad;
1692 xdp_set_data_meta_invalid(&xdp);
1693 xdp.data_end = xdp.data + len;
1694 xdp.rxq = &tfile->xdp_rxq;
1695
1696 act = bpf_prog_run_xdp(xdp_prog, &xdp);
1697 if (act == XDP_REDIRECT || act == XDP_TX) {
1698 get_page(alloc_frag->page);
1699 alloc_frag->offset += buflen;
1700 }
1701 err = tun_xdp_act(tun, xdp_prog, &xdp, act);
1702 if (err < 0)
1703 goto err_xdp;
1704 if (err == XDP_REDIRECT)
1705 xdp_do_flush_map();
1706 if (err != XDP_PASS)
1707 goto out;
1708
1709 pad = xdp.data - xdp.data_hard_start;
1710 len = xdp.data_end - xdp.data;
1711 }
1712 rcu_read_unlock();
1713 local_bh_enable();
1714
1715 return __tun_build_skb(alloc_frag, buf, buflen, len, pad);
1716
1717 err_xdp:
1718 put_page(alloc_frag->page);
1719 out:
1720 rcu_read_unlock();
1721 local_bh_enable();
1722 return NULL;
1723 }
1724
1725 /* Get packet from user space buffer */
1726 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1727 void *msg_control, struct iov_iter *from,
1728 int noblock, bool more)
1729 {
1730 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1731 struct sk_buff *skb;
1732 size_t total_len = iov_iter_count(from);
1733 size_t len = total_len, align = tun->align, linear;
1734 struct virtio_net_hdr gso = { 0 };
1735 struct tun_pcpu_stats *stats;
1736 int good_linear;
1737 int copylen;
1738 bool zerocopy = false;
1739 int err;
1740 u32 rxhash = 0;
1741 int skb_xdp = 1;
1742 bool frags = tun_napi_frags_enabled(tfile);
1743
1744 if (!(tun->dev->flags & IFF_UP))
1745 return -EIO;
1746
1747 if (!(tun->flags & IFF_NO_PI)) {
1748 if (len < sizeof(pi))
1749 return -EINVAL;
1750 len -= sizeof(pi);
1751
1752 if (!copy_from_iter_full(&pi, sizeof(pi), from))
1753 return -EFAULT;
1754 }
1755
1756 if (tun->flags & IFF_VNET_HDR) {
1757 int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
1758
1759 if (len < vnet_hdr_sz)
1760 return -EINVAL;
1761 len -= vnet_hdr_sz;
1762
1763 if (!copy_from_iter_full(&gso, sizeof(gso), from))
1764 return -EFAULT;
1765
1766 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1767 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1768 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1769
1770 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1771 return -EINVAL;
1772 iov_iter_advance(from, vnet_hdr_sz - sizeof(gso));
1773 }
1774
1775 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1776 align += NET_IP_ALIGN;
1777 if (unlikely(len < ETH_HLEN ||
1778 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1779 return -EINVAL;
1780 }
1781
1782 good_linear = SKB_MAX_HEAD(align);
1783
1784 if (msg_control) {
1785 struct iov_iter i = *from;
1786
1787 /* There are 256 bytes to be copied in skb, so there is
1788 * enough room for skb expand head in case it is used.
1789 * The rest of the buffer is mapped from userspace.
1790 */
1791 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1792 if (copylen > good_linear)
1793 copylen = good_linear;
1794 linear = copylen;
1795 iov_iter_advance(&i, copylen);
1796 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1797 zerocopy = true;
1798 }
1799
1800 if (!frags && tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) {
1801 /* For the packet that is not easy to be processed
1802 * (e.g gso or jumbo packet), we will do it at after
1803 * skb was created with generic XDP routine.
1804 */
1805 skb = tun_build_skb(tun, tfile, from, &gso, len, &skb_xdp);
1806 if (IS_ERR(skb)) {
1807 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1808 return PTR_ERR(skb);
1809 }
1810 if (!skb)
1811 return total_len;
1812 } else {
1813 if (!zerocopy) {
1814 copylen = len;
1815 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1816 linear = good_linear;
1817 else
1818 linear = tun16_to_cpu(tun, gso.hdr_len);
1819 }
1820
1821 if (frags) {
1822 mutex_lock(&tfile->napi_mutex);
1823 skb = tun_napi_alloc_frags(tfile, copylen, from);
1824 /* tun_napi_alloc_frags() enforces a layout for the skb.
1825 * If zerocopy is enabled, then this layout will be
1826 * overwritten by zerocopy_sg_from_iter().
1827 */
1828 zerocopy = false;
1829 } else {
1830 skb = tun_alloc_skb(tfile, align, copylen, linear,
1831 noblock);
1832 }
1833
1834 if (IS_ERR(skb)) {
1835 if (PTR_ERR(skb) != -EAGAIN)
1836 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1837 if (frags)
1838 mutex_unlock(&tfile->napi_mutex);
1839 return PTR_ERR(skb);
1840 }
1841
1842 if (zerocopy)
1843 err = zerocopy_sg_from_iter(skb, from);
1844 else
1845 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1846
1847 if (err) {
1848 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1849 kfree_skb(skb);
1850 if (frags) {
1851 tfile->napi.skb = NULL;
1852 mutex_unlock(&tfile->napi_mutex);
1853 }
1854
1855 return -EFAULT;
1856 }
1857 }
1858
1859 if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) {
1860 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
1861 kfree_skb(skb);
1862 if (frags) {
1863 tfile->napi.skb = NULL;
1864 mutex_unlock(&tfile->napi_mutex);
1865 }
1866
1867 return -EINVAL;
1868 }
1869
1870 switch (tun->flags & TUN_TYPE_MASK) {
1871 case IFF_TUN:
1872 if (tun->flags & IFF_NO_PI) {
1873 u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0;
1874
1875 switch (ip_version) {
1876 case 4:
1877 pi.proto = htons(ETH_P_IP);
1878 break;
1879 case 6:
1880 pi.proto = htons(ETH_P_IPV6);
1881 break;
1882 default:
1883 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1884 kfree_skb(skb);
1885 return -EINVAL;
1886 }
1887 }
1888
1889 skb_reset_mac_header(skb);
1890 skb->protocol = pi.proto;
1891 skb->dev = tun->dev;
1892 break;
1893 case IFF_TAP:
1894 if (!frags)
1895 skb->protocol = eth_type_trans(skb, tun->dev);
1896 break;
1897 }
1898
1899 /* copy skb_ubuf_info for callback when skb has no error */
1900 if (zerocopy) {
1901 skb_shinfo(skb)->destructor_arg = msg_control;
1902 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1903 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1904 } else if (msg_control) {
1905 struct ubuf_info *uarg = msg_control;
1906 uarg->callback(uarg, false);
1907 }
1908
1909 skb_reset_network_header(skb);
1910 skb_probe_transport_header(skb, 0);
1911
1912 if (skb_xdp) {
1913 struct bpf_prog *xdp_prog;
1914 int ret;
1915
1916 local_bh_disable();
1917 rcu_read_lock();
1918 xdp_prog = rcu_dereference(tun->xdp_prog);
1919 if (xdp_prog) {
1920 ret = do_xdp_generic(xdp_prog, skb);
1921 if (ret != XDP_PASS) {
1922 rcu_read_unlock();
1923 local_bh_enable();
1924 return total_len;
1925 }
1926 }
1927 rcu_read_unlock();
1928 local_bh_enable();
1929 }
1930
1931 /* Compute the costly rx hash only if needed for flow updates.
1932 * We may get a very small possibility of OOO during switching, not
1933 * worth to optimize.
1934 */
1935 if (!rcu_access_pointer(tun->steering_prog) && tun->numqueues > 1 &&
1936 !tfile->detached)
1937 rxhash = __skb_get_hash_symmetric(skb);
1938
1939 if (frags) {
1940 /* Exercise flow dissector code path. */
1941 u32 headlen = eth_get_headlen(skb->data, skb_headlen(skb));
1942
1943 if (unlikely(headlen > skb_headlen(skb))) {
1944 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1945 napi_free_frags(&tfile->napi);
1946 mutex_unlock(&tfile->napi_mutex);
1947 WARN_ON(1);
1948 return -ENOMEM;
1949 }
1950
1951 local_bh_disable();
1952 napi_gro_frags(&tfile->napi);
1953 local_bh_enable();
1954 mutex_unlock(&tfile->napi_mutex);
1955 } else if (tfile->napi_enabled) {
1956 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1957 int queue_len;
1958
1959 spin_lock_bh(&queue->lock);
1960 __skb_queue_tail(queue, skb);
1961 queue_len = skb_queue_len(queue);
1962 spin_unlock(&queue->lock);
1963
1964 if (!more || queue_len > NAPI_POLL_WEIGHT)
1965 napi_schedule(&tfile->napi);
1966
1967 local_bh_enable();
1968 } else if (!IS_ENABLED(CONFIG_4KSTACKS)) {
1969 tun_rx_batched(tun, tfile, skb, more);
1970 } else {
1971 netif_rx_ni(skb);
1972 }
1973
1974 stats = get_cpu_ptr(tun->pcpu_stats);
1975 u64_stats_update_begin(&stats->syncp);
1976 stats->rx_packets++;
1977 stats->rx_bytes += len;
1978 u64_stats_update_end(&stats->syncp);
1979 put_cpu_ptr(stats);
1980
1981 if (rxhash)
1982 tun_flow_update(tun, rxhash, tfile);
1983
1984 return total_len;
1985 }
1986
1987 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1988 {
1989 struct file *file = iocb->ki_filp;
1990 struct tun_file *tfile = file->private_data;
1991 struct tun_struct *tun = tun_get(tfile);
1992 ssize_t result;
1993
1994 if (!tun)
1995 return -EBADFD;
1996
1997 result = tun_get_user(tun, tfile, NULL, from,
1998 file->f_flags & O_NONBLOCK, false);
1999
2000 tun_put(tun);
2001 return result;
2002 }
2003
2004 static ssize_t tun_put_user_xdp(struct tun_struct *tun,
2005 struct tun_file *tfile,
2006 struct xdp_frame *xdp_frame,
2007 struct iov_iter *iter)
2008 {
2009 int vnet_hdr_sz = 0;
2010 size_t size = xdp_frame->len;
2011 struct tun_pcpu_stats *stats;
2012 size_t ret;
2013
2014 if (tun->flags & IFF_VNET_HDR) {
2015 struct virtio_net_hdr gso = { 0 };
2016
2017 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2018 if (unlikely(iov_iter_count(iter) < vnet_hdr_sz))
2019 return -EINVAL;
2020 if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) !=
2021 sizeof(gso)))
2022 return -EFAULT;
2023 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2024 }
2025
2026 ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
2027
2028 stats = get_cpu_ptr(tun->pcpu_stats);
2029 u64_stats_update_begin(&stats->syncp);
2030 stats->tx_packets++;
2031 stats->tx_bytes += ret;
2032 u64_stats_update_end(&stats->syncp);
2033 put_cpu_ptr(tun->pcpu_stats);
2034
2035 return ret;
2036 }
2037
2038 /* Put packet to the user space buffer */
2039 static ssize_t tun_put_user(struct tun_struct *tun,
2040 struct tun_file *tfile,
2041 struct sk_buff *skb,
2042 struct iov_iter *iter)
2043 {
2044 struct tun_pi pi = { 0, skb->protocol };
2045 struct tun_pcpu_stats *stats;
2046 ssize_t total;
2047 int vlan_offset = 0;
2048 int vlan_hlen = 0;
2049 int vnet_hdr_sz = 0;
2050
2051 if (skb_vlan_tag_present(skb))
2052 vlan_hlen = VLAN_HLEN;
2053
2054 if (tun->flags & IFF_VNET_HDR)
2055 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2056
2057 total = skb->len + vlan_hlen + vnet_hdr_sz;
2058
2059 if (!(tun->flags & IFF_NO_PI)) {
2060 if (iov_iter_count(iter) < sizeof(pi))
2061 return -EINVAL;
2062
2063 total += sizeof(pi);
2064 if (iov_iter_count(iter) < total) {
2065 /* Packet will be striped */
2066 pi.flags |= TUN_PKT_STRIP;
2067 }
2068
2069 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
2070 return -EFAULT;
2071 }
2072
2073 if (vnet_hdr_sz) {
2074 struct virtio_net_hdr gso;
2075
2076 if (iov_iter_count(iter) < vnet_hdr_sz)
2077 return -EINVAL;
2078
2079 if (virtio_net_hdr_from_skb(skb, &gso,
2080 tun_is_little_endian(tun), true,
2081 vlan_hlen)) {
2082 struct skb_shared_info *sinfo = skb_shinfo(skb);
2083 pr_err("unexpected GSO type: "
2084 "0x%x, gso_size %d, hdr_len %d\n",
2085 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
2086 tun16_to_cpu(tun, gso.hdr_len));
2087 print_hex_dump(KERN_ERR, "tun: ",
2088 DUMP_PREFIX_NONE,
2089 16, 1, skb->head,
2090 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
2091 WARN_ON_ONCE(1);
2092 return -EINVAL;
2093 }
2094
2095 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
2096 return -EFAULT;
2097
2098 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2099 }
2100
2101 if (vlan_hlen) {
2102 int ret;
2103 struct veth veth;
2104
2105 veth.h_vlan_proto = skb->vlan_proto;
2106 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
2107
2108 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
2109
2110 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
2111 if (ret || !iov_iter_count(iter))
2112 goto done;
2113
2114 ret = copy_to_iter(&veth, sizeof(veth), iter);
2115 if (ret != sizeof(veth) || !iov_iter_count(iter))
2116 goto done;
2117 }
2118
2119 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
2120
2121 done:
2122 /* caller is in process context, */
2123 stats = get_cpu_ptr(tun->pcpu_stats);
2124 u64_stats_update_begin(&stats->syncp);
2125 stats->tx_packets++;
2126 stats->tx_bytes += skb->len + vlan_hlen;
2127 u64_stats_update_end(&stats->syncp);
2128 put_cpu_ptr(tun->pcpu_stats);
2129
2130 return total;
2131 }
2132
2133 static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
2134 {
2135 DECLARE_WAITQUEUE(wait, current);
2136 void *ptr = NULL;
2137 int error = 0;
2138
2139 ptr = ptr_ring_consume(&tfile->tx_ring);
2140 if (ptr)
2141 goto out;
2142 if (noblock) {
2143 error = -EAGAIN;
2144 goto out;
2145 }
2146
2147 add_wait_queue(&tfile->wq.wait, &wait);
2148 current->state = TASK_INTERRUPTIBLE;
2149
2150 while (1) {
2151 ptr = ptr_ring_consume(&tfile->tx_ring);
2152 if (ptr)
2153 break;
2154 if (signal_pending(current)) {
2155 error = -ERESTARTSYS;
2156 break;
2157 }
2158 if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
2159 error = -EFAULT;
2160 break;
2161 }
2162
2163 schedule();
2164 }
2165
2166 current->state = TASK_RUNNING;
2167 remove_wait_queue(&tfile->wq.wait, &wait);
2168
2169 out:
2170 *err = error;
2171 return ptr;
2172 }
2173
2174 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
2175 struct iov_iter *to,
2176 int noblock, void *ptr)
2177 {
2178 ssize_t ret;
2179 int err;
2180
2181 tun_debug(KERN_INFO, tun, "tun_do_read\n");
2182
2183 if (!iov_iter_count(to)) {
2184 tun_ptr_free(ptr);
2185 return 0;
2186 }
2187
2188 if (!ptr) {
2189 /* Read frames from ring */
2190 ptr = tun_ring_recv(tfile, noblock, &err);
2191 if (!ptr)
2192 return err;
2193 }
2194
2195 if (tun_is_xdp_frame(ptr)) {
2196 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2197
2198 ret = tun_put_user_xdp(tun, tfile, xdpf, to);
2199 xdp_return_frame(xdpf);
2200 } else {
2201 struct sk_buff *skb = ptr;
2202
2203 ret = tun_put_user(tun, tfile, skb, to);
2204 if (unlikely(ret < 0))
2205 kfree_skb(skb);
2206 else
2207 consume_skb(skb);
2208 }
2209
2210 return ret;
2211 }
2212
2213 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
2214 {
2215 struct file *file = iocb->ki_filp;
2216 struct tun_file *tfile = file->private_data;
2217 struct tun_struct *tun = tun_get(tfile);
2218 ssize_t len = iov_iter_count(to), ret;
2219
2220 if (!tun)
2221 return -EBADFD;
2222 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL);
2223 ret = min_t(ssize_t, ret, len);
2224 if (ret > 0)
2225 iocb->ki_pos = ret;
2226 tun_put(tun);
2227 return ret;
2228 }
2229
2230 static void tun_prog_free(struct rcu_head *rcu)
2231 {
2232 struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu);
2233
2234 bpf_prog_destroy(prog->prog);
2235 kfree(prog);
2236 }
2237
2238 static int __tun_set_ebpf(struct tun_struct *tun,
2239 struct tun_prog __rcu **prog_p,
2240 struct bpf_prog *prog)
2241 {
2242 struct tun_prog *old, *new = NULL;
2243
2244 if (prog) {
2245 new = kmalloc(sizeof(*new), GFP_KERNEL);
2246 if (!new)
2247 return -ENOMEM;
2248 new->prog = prog;
2249 }
2250
2251 spin_lock_bh(&tun->lock);
2252 old = rcu_dereference_protected(*prog_p,
2253 lockdep_is_held(&tun->lock));
2254 rcu_assign_pointer(*prog_p, new);
2255 spin_unlock_bh(&tun->lock);
2256
2257 if (old)
2258 call_rcu(&old->rcu, tun_prog_free);
2259
2260 return 0;
2261 }
2262
2263 static void tun_free_netdev(struct net_device *dev)
2264 {
2265 struct tun_struct *tun = netdev_priv(dev);
2266
2267 BUG_ON(!(list_empty(&tun->disabled)));
2268 free_percpu(tun->pcpu_stats);
2269 tun_flow_uninit(tun);
2270 security_tun_dev_free_security(tun->security);
2271 __tun_set_ebpf(tun, &tun->steering_prog, NULL);
2272 __tun_set_ebpf(tun, &tun->filter_prog, NULL);
2273 }
2274
2275 static void tun_setup(struct net_device *dev)
2276 {
2277 struct tun_struct *tun = netdev_priv(dev);
2278
2279 tun->owner = INVALID_UID;
2280 tun->group = INVALID_GID;
2281 tun_default_link_ksettings(dev, &tun->link_ksettings);
2282
2283 dev->ethtool_ops = &tun_ethtool_ops;
2284 dev->needs_free_netdev = true;
2285 dev->priv_destructor = tun_free_netdev;
2286 /* We prefer our own queue length */
2287 dev->tx_queue_len = TUN_READQ_SIZE;
2288 }
2289
2290 /* Trivial set of netlink ops to allow deleting tun or tap
2291 * device with netlink.
2292 */
2293 static int tun_validate(struct nlattr *tb[], struct nlattr *data[],
2294 struct netlink_ext_ack *extack)
2295 {
2296 NL_SET_ERR_MSG(extack,
2297 "tun/tap creation via rtnetlink is not supported.");
2298 return -EOPNOTSUPP;
2299 }
2300
2301 static size_t tun_get_size(const struct net_device *dev)
2302 {
2303 BUILD_BUG_ON(sizeof(u32) != sizeof(uid_t));
2304 BUILD_BUG_ON(sizeof(u32) != sizeof(gid_t));
2305
2306 return nla_total_size(sizeof(uid_t)) + /* OWNER */
2307 nla_total_size(sizeof(gid_t)) + /* GROUP */
2308 nla_total_size(sizeof(u8)) + /* TYPE */
2309 nla_total_size(sizeof(u8)) + /* PI */
2310 nla_total_size(sizeof(u8)) + /* VNET_HDR */
2311 nla_total_size(sizeof(u8)) + /* PERSIST */
2312 nla_total_size(sizeof(u8)) + /* MULTI_QUEUE */
2313 nla_total_size(sizeof(u32)) + /* NUM_QUEUES */
2314 nla_total_size(sizeof(u32)) + /* NUM_DISABLED_QUEUES */
2315 0;
2316 }
2317
2318 static int tun_fill_info(struct sk_buff *skb, const struct net_device *dev)
2319 {
2320 struct tun_struct *tun = netdev_priv(dev);
2321
2322 if (nla_put_u8(skb, IFLA_TUN_TYPE, tun->flags & TUN_TYPE_MASK))
2323 goto nla_put_failure;
2324 if (uid_valid(tun->owner) &&
2325 nla_put_u32(skb, IFLA_TUN_OWNER,
2326 from_kuid_munged(current_user_ns(), tun->owner)))
2327 goto nla_put_failure;
2328 if (gid_valid(tun->group) &&
2329 nla_put_u32(skb, IFLA_TUN_GROUP,
2330 from_kgid_munged(current_user_ns(), tun->group)))
2331 goto nla_put_failure;
2332 if (nla_put_u8(skb, IFLA_TUN_PI, !(tun->flags & IFF_NO_PI)))
2333 goto nla_put_failure;
2334 if (nla_put_u8(skb, IFLA_TUN_VNET_HDR, !!(tun->flags & IFF_VNET_HDR)))
2335 goto nla_put_failure;
2336 if (nla_put_u8(skb, IFLA_TUN_PERSIST, !!(tun->flags & IFF_PERSIST)))
2337 goto nla_put_failure;
2338 if (nla_put_u8(skb, IFLA_TUN_MULTI_QUEUE,
2339 !!(tun->flags & IFF_MULTI_QUEUE)))
2340 goto nla_put_failure;
2341 if (tun->flags & IFF_MULTI_QUEUE) {
2342 if (nla_put_u32(skb, IFLA_TUN_NUM_QUEUES, tun->numqueues))
2343 goto nla_put_failure;
2344 if (nla_put_u32(skb, IFLA_TUN_NUM_DISABLED_QUEUES,
2345 tun->numdisabled))
2346 goto nla_put_failure;
2347 }
2348
2349 return 0;
2350
2351 nla_put_failure:
2352 return -EMSGSIZE;
2353 }
2354
2355 static struct rtnl_link_ops tun_link_ops __read_mostly = {
2356 .kind = DRV_NAME,
2357 .priv_size = sizeof(struct tun_struct),
2358 .setup = tun_setup,
2359 .validate = tun_validate,
2360 .get_size = tun_get_size,
2361 .fill_info = tun_fill_info,
2362 };
2363
2364 static void tun_sock_write_space(struct sock *sk)
2365 {
2366 struct tun_file *tfile;
2367 wait_queue_head_t *wqueue;
2368
2369 if (!sock_writeable(sk))
2370 return;
2371
2372 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
2373 return;
2374
2375 wqueue = sk_sleep(sk);
2376 if (wqueue && waitqueue_active(wqueue))
2377 wake_up_interruptible_sync_poll(wqueue, EPOLLOUT |
2378 EPOLLWRNORM | EPOLLWRBAND);
2379
2380 tfile = container_of(sk, struct tun_file, sk);
2381 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
2382 }
2383
2384 static int tun_xdp_one(struct tun_struct *tun,
2385 struct tun_file *tfile,
2386 struct xdp_buff *xdp, int *flush)
2387 {
2388 unsigned int datasize = xdp->data_end - xdp->data;
2389 struct tun_xdp_hdr *hdr = xdp->data_hard_start;
2390 struct virtio_net_hdr *gso = &hdr->gso;
2391 struct tun_pcpu_stats *stats;
2392 struct bpf_prog *xdp_prog;
2393 struct sk_buff *skb = NULL;
2394 u32 rxhash = 0, act;
2395 int buflen = hdr->buflen;
2396 int err = 0;
2397 bool skb_xdp = false;
2398
2399 xdp_prog = rcu_dereference(tun->xdp_prog);
2400 if (xdp_prog) {
2401 if (gso->gso_type) {
2402 skb_xdp = true;
2403 goto build;
2404 }
2405 xdp_set_data_meta_invalid(xdp);
2406 xdp->rxq = &tfile->xdp_rxq;
2407
2408 act = bpf_prog_run_xdp(xdp_prog, xdp);
2409 err = tun_xdp_act(tun, xdp_prog, xdp, act);
2410 if (err < 0) {
2411 put_page(virt_to_head_page(xdp->data));
2412 return err;
2413 }
2414
2415 switch (err) {
2416 case XDP_REDIRECT:
2417 *flush = true;
2418 /* fall through */
2419 case XDP_TX:
2420 return 0;
2421 case XDP_PASS:
2422 break;
2423 default:
2424 put_page(virt_to_head_page(xdp->data));
2425 return 0;
2426 }
2427 }
2428
2429 build:
2430 skb = build_skb(xdp->data_hard_start, buflen);
2431 if (!skb) {
2432 err = -ENOMEM;
2433 goto out;
2434 }
2435
2436 skb_reserve(skb, xdp->data - xdp->data_hard_start);
2437 skb_put(skb, xdp->data_end - xdp->data);
2438
2439 if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) {
2440 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
2441 kfree_skb(skb);
2442 err = -EINVAL;
2443 goto out;
2444 }
2445
2446 skb->protocol = eth_type_trans(skb, tun->dev);
2447 skb_reset_network_header(skb);
2448 skb_probe_transport_header(skb, 0);
2449
2450 if (skb_xdp) {
2451 err = do_xdp_generic(xdp_prog, skb);
2452 if (err != XDP_PASS)
2453 goto out;
2454 }
2455
2456 if (!rcu_dereference(tun->steering_prog))
2457 rxhash = __skb_get_hash_symmetric(skb);
2458
2459 skb_record_rx_queue(skb, tfile->queue_index);
2460 netif_receive_skb(skb);
2461
2462 stats = get_cpu_ptr(tun->pcpu_stats);
2463 u64_stats_update_begin(&stats->syncp);
2464 stats->rx_packets++;
2465 stats->rx_bytes += datasize;
2466 u64_stats_update_end(&stats->syncp);
2467 put_cpu_ptr(stats);
2468
2469 if (rxhash)
2470 tun_flow_update(tun, rxhash, tfile);
2471
2472 out:
2473 return err;
2474 }
2475
2476 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
2477 {
2478 int ret, i;
2479 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2480 struct tun_struct *tun = tun_get(tfile);
2481 struct tun_msg_ctl *ctl = m->msg_control;
2482 struct xdp_buff *xdp;
2483
2484 if (!tun)
2485 return -EBADFD;
2486
2487 if (ctl && (ctl->type == TUN_MSG_PTR)) {
2488 int n = ctl->num;
2489 int flush = 0;
2490
2491 local_bh_disable();
2492 rcu_read_lock();
2493
2494 for (i = 0; i < n; i++) {
2495 xdp = &((struct xdp_buff *)ctl->ptr)[i];
2496 tun_xdp_one(tun, tfile, xdp, &flush);
2497 }
2498
2499 if (flush)
2500 xdp_do_flush_map();
2501
2502 rcu_read_unlock();
2503 local_bh_enable();
2504
2505 ret = total_len;
2506 goto out;
2507 }
2508
2509 ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
2510 m->msg_flags & MSG_DONTWAIT,
2511 m->msg_flags & MSG_MORE);
2512 out:
2513 tun_put(tun);
2514 return ret;
2515 }
2516
2517 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
2518 int flags)
2519 {
2520 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2521 struct tun_struct *tun = tun_get(tfile);
2522 void *ptr = m->msg_control;
2523 int ret;
2524
2525 if (!tun) {
2526 ret = -EBADFD;
2527 goto out_free;
2528 }
2529
2530 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
2531 ret = -EINVAL;
2532 goto out_put_tun;
2533 }
2534 if (flags & MSG_ERRQUEUE) {
2535 ret = sock_recv_errqueue(sock->sk, m, total_len,
2536 SOL_PACKET, TUN_TX_TIMESTAMP);
2537 goto out;
2538 }
2539 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, ptr);
2540 if (ret > (ssize_t)total_len) {
2541 m->msg_flags |= MSG_TRUNC;
2542 ret = flags & MSG_TRUNC ? ret : total_len;
2543 }
2544 out:
2545 tun_put(tun);
2546 return ret;
2547
2548 out_put_tun:
2549 tun_put(tun);
2550 out_free:
2551 tun_ptr_free(ptr);
2552 return ret;
2553 }
2554
2555 static int tun_ptr_peek_len(void *ptr)
2556 {
2557 if (likely(ptr)) {
2558 if (tun_is_xdp_frame(ptr)) {
2559 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2560
2561 return xdpf->len;
2562 }
2563 return __skb_array_len_with_tag(ptr);
2564 } else {
2565 return 0;
2566 }
2567 }
2568
2569 static int tun_peek_len(struct socket *sock)
2570 {
2571 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2572 struct tun_struct *tun;
2573 int ret = 0;
2574
2575 tun = tun_get(tfile);
2576 if (!tun)
2577 return 0;
2578
2579 ret = PTR_RING_PEEK_CALL(&tfile->tx_ring, tun_ptr_peek_len);
2580 tun_put(tun);
2581
2582 return ret;
2583 }
2584
2585 /* Ops structure to mimic raw sockets with tun */
2586 static const struct proto_ops tun_socket_ops = {
2587 .peek_len = tun_peek_len,
2588 .sendmsg = tun_sendmsg,
2589 .recvmsg = tun_recvmsg,
2590 };
2591
2592 static struct proto tun_proto = {
2593 .name = "tun",
2594 .owner = THIS_MODULE,
2595 .obj_size = sizeof(struct tun_file),
2596 };
2597
2598 static int tun_flags(struct tun_struct *tun)
2599 {
2600 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
2601 }
2602
2603 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
2604 char *buf)
2605 {
2606 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2607 return sprintf(buf, "0x%x\n", tun_flags(tun));
2608 }
2609
2610 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
2611 char *buf)
2612 {
2613 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2614 return uid_valid(tun->owner)?
2615 sprintf(buf, "%u\n",
2616 from_kuid_munged(current_user_ns(), tun->owner)):
2617 sprintf(buf, "-1\n");
2618 }
2619
2620 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
2621 char *buf)
2622 {
2623 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2624 return gid_valid(tun->group) ?
2625 sprintf(buf, "%u\n",
2626 from_kgid_munged(current_user_ns(), tun->group)):
2627 sprintf(buf, "-1\n");
2628 }
2629
2630 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
2631 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
2632 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
2633
2634 static struct attribute *tun_dev_attrs[] = {
2635 &dev_attr_tun_flags.attr,
2636 &dev_attr_owner.attr,
2637 &dev_attr_group.attr,
2638 NULL
2639 };
2640
2641 static const struct attribute_group tun_attr_group = {
2642 .attrs = tun_dev_attrs
2643 };
2644
2645 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
2646 {
2647 struct tun_struct *tun;
2648 struct tun_file *tfile = file->private_data;
2649 struct net_device *dev;
2650 int err;
2651
2652 if (tfile->detached)
2653 return -EINVAL;
2654
2655 if ((ifr->ifr_flags & IFF_NAPI_FRAGS)) {
2656 if (!capable(CAP_NET_ADMIN))
2657 return -EPERM;
2658
2659 if (!(ifr->ifr_flags & IFF_NAPI) ||
2660 (ifr->ifr_flags & TUN_TYPE_MASK) != IFF_TAP)
2661 return -EINVAL;
2662 }
2663
2664 dev = __dev_get_by_name(net, ifr->ifr_name);
2665 if (dev) {
2666 if (ifr->ifr_flags & IFF_TUN_EXCL)
2667 return -EBUSY;
2668 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
2669 tun = netdev_priv(dev);
2670 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
2671 tun = netdev_priv(dev);
2672 else
2673 return -EINVAL;
2674
2675 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
2676 !!(tun->flags & IFF_MULTI_QUEUE))
2677 return -EINVAL;
2678
2679 if (tun_not_capable(tun))
2680 return -EPERM;
2681 err = security_tun_dev_open(tun->security);
2682 if (err < 0)
2683 return err;
2684
2685 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
2686 ifr->ifr_flags & IFF_NAPI,
2687 ifr->ifr_flags & IFF_NAPI_FRAGS);
2688 if (err < 0)
2689 return err;
2690
2691 if (tun->flags & IFF_MULTI_QUEUE &&
2692 (tun->numqueues + tun->numdisabled > 1)) {
2693 /* One or more queue has already been attached, no need
2694 * to initialize the device again.
2695 */
2696 netdev_state_change(dev);
2697 return 0;
2698 }
2699
2700 tun->flags = (tun->flags & ~TUN_FEATURES) |
2701 (ifr->ifr_flags & TUN_FEATURES);
2702
2703 netdev_state_change(dev);
2704 } else {
2705 char *name;
2706 unsigned long flags = 0;
2707 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
2708 MAX_TAP_QUEUES : 1;
2709
2710 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2711 return -EPERM;
2712 err = security_tun_dev_create();
2713 if (err < 0)
2714 return err;
2715
2716 /* Set dev type */
2717 if (ifr->ifr_flags & IFF_TUN) {
2718 /* TUN device */
2719 flags |= IFF_TUN;
2720 name = "tun%d";
2721 } else if (ifr->ifr_flags & IFF_TAP) {
2722 /* TAP device */
2723 flags |= IFF_TAP;
2724 name = "tap%d";
2725 } else
2726 return -EINVAL;
2727
2728 if (*ifr->ifr_name)
2729 name = ifr->ifr_name;
2730
2731 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
2732 NET_NAME_UNKNOWN, tun_setup, queues,
2733 queues);
2734
2735 if (!dev)
2736 return -ENOMEM;
2737 err = dev_get_valid_name(net, dev, name);
2738 if (err < 0)
2739 goto err_free_dev;
2740
2741 dev_net_set(dev, net);
2742 dev->rtnl_link_ops = &tun_link_ops;
2743 dev->ifindex = tfile->ifindex;
2744 dev->sysfs_groups[0] = &tun_attr_group;
2745
2746 tun = netdev_priv(dev);
2747 tun->dev = dev;
2748 tun->flags = flags;
2749 tun->txflt.count = 0;
2750 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
2751
2752 tun->align = NET_SKB_PAD;
2753 tun->filter_attached = false;
2754 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
2755 tun->rx_batched = 0;
2756 RCU_INIT_POINTER(tun->steering_prog, NULL);
2757
2758 tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
2759 if (!tun->pcpu_stats) {
2760 err = -ENOMEM;
2761 goto err_free_dev;
2762 }
2763
2764 spin_lock_init(&tun->lock);
2765
2766 err = security_tun_dev_alloc_security(&tun->security);
2767 if (err < 0)
2768 goto err_free_stat;
2769
2770 tun_net_init(dev);
2771 tun_flow_init(tun);
2772
2773 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
2774 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
2775 NETIF_F_HW_VLAN_STAG_TX;
2776 dev->features = dev->hw_features | NETIF_F_LLTX;
2777 dev->vlan_features = dev->features &
2778 ~(NETIF_F_HW_VLAN_CTAG_TX |
2779 NETIF_F_HW_VLAN_STAG_TX);
2780
2781 tun->flags = (tun->flags & ~TUN_FEATURES) |
2782 (ifr->ifr_flags & TUN_FEATURES);
2783
2784 INIT_LIST_HEAD(&tun->disabled);
2785 err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
2786 ifr->ifr_flags & IFF_NAPI_FRAGS);
2787 if (err < 0)
2788 goto err_free_flow;
2789
2790 err = register_netdevice(tun->dev);
2791 if (err < 0)
2792 goto err_detach;
2793 }
2794
2795 netif_carrier_on(tun->dev);
2796
2797 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
2798
2799 /* Make sure persistent devices do not get stuck in
2800 * xoff state.
2801 */
2802 if (netif_running(tun->dev))
2803 netif_tx_wake_all_queues(tun->dev);
2804
2805 strcpy(ifr->ifr_name, tun->dev->name);
2806 return 0;
2807
2808 err_detach:
2809 tun_detach_all(dev);
2810 /* register_netdevice() already called tun_free_netdev() */
2811 goto err_free_dev;
2812
2813 err_free_flow:
2814 tun_flow_uninit(tun);
2815 security_tun_dev_free_security(tun->security);
2816 err_free_stat:
2817 free_percpu(tun->pcpu_stats);
2818 err_free_dev:
2819 free_netdev(dev);
2820 return err;
2821 }
2822
2823 static void tun_get_iff(struct net *net, struct tun_struct *tun,
2824 struct ifreq *ifr)
2825 {
2826 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
2827
2828 strcpy(ifr->ifr_name, tun->dev->name);
2829
2830 ifr->ifr_flags = tun_flags(tun);
2831
2832 }
2833
2834 /* This is like a cut-down ethtool ops, except done via tun fd so no
2835 * privs required. */
2836 static int set_offload(struct tun_struct *tun, unsigned long arg)
2837 {
2838 netdev_features_t features = 0;
2839
2840 if (arg & TUN_F_CSUM) {
2841 features |= NETIF_F_HW_CSUM;
2842 arg &= ~TUN_F_CSUM;
2843
2844 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
2845 if (arg & TUN_F_TSO_ECN) {
2846 features |= NETIF_F_TSO_ECN;
2847 arg &= ~TUN_F_TSO_ECN;
2848 }
2849 if (arg & TUN_F_TSO4)
2850 features |= NETIF_F_TSO;
2851 if (arg & TUN_F_TSO6)
2852 features |= NETIF_F_TSO6;
2853 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
2854 }
2855
2856 arg &= ~TUN_F_UFO;
2857 }
2858
2859 /* This gives the user a way to test for new features in future by
2860 * trying to set them. */
2861 if (arg)
2862 return -EINVAL;
2863
2864 tun->set_features = features;
2865 tun->dev->wanted_features &= ~TUN_USER_FEATURES;
2866 tun->dev->wanted_features |= features;
2867 netdev_update_features(tun->dev);
2868
2869 return 0;
2870 }
2871
2872 static void tun_detach_filter(struct tun_struct *tun, int n)
2873 {
2874 int i;
2875 struct tun_file *tfile;
2876
2877 for (i = 0; i < n; i++) {
2878 tfile = rtnl_dereference(tun->tfiles[i]);
2879 lock_sock(tfile->socket.sk);
2880 sk_detach_filter(tfile->socket.sk);
2881 release_sock(tfile->socket.sk);
2882 }
2883
2884 tun->filter_attached = false;
2885 }
2886
2887 static int tun_attach_filter(struct tun_struct *tun)
2888 {
2889 int i, ret = 0;
2890 struct tun_file *tfile;
2891
2892 for (i = 0; i < tun->numqueues; i++) {
2893 tfile = rtnl_dereference(tun->tfiles[i]);
2894 lock_sock(tfile->socket.sk);
2895 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
2896 release_sock(tfile->socket.sk);
2897 if (ret) {
2898 tun_detach_filter(tun, i);
2899 return ret;
2900 }
2901 }
2902
2903 tun->filter_attached = true;
2904 return ret;
2905 }
2906
2907 static void tun_set_sndbuf(struct tun_struct *tun)
2908 {
2909 struct tun_file *tfile;
2910 int i;
2911
2912 for (i = 0; i < tun->numqueues; i++) {
2913 tfile = rtnl_dereference(tun->tfiles[i]);
2914 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
2915 }
2916 }
2917
2918 static int tun_set_queue(struct file *file, struct ifreq *ifr)
2919 {
2920 struct tun_file *tfile = file->private_data;
2921 struct tun_struct *tun;
2922 int ret = 0;
2923
2924 rtnl_lock();
2925
2926 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
2927 tun = tfile->detached;
2928 if (!tun) {
2929 ret = -EINVAL;
2930 goto unlock;
2931 }
2932 ret = security_tun_dev_attach_queue(tun->security);
2933 if (ret < 0)
2934 goto unlock;
2935 ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI,
2936 tun->flags & IFF_NAPI_FRAGS);
2937 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
2938 tun = rtnl_dereference(tfile->tun);
2939 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
2940 ret = -EINVAL;
2941 else
2942 __tun_detach(tfile, false);
2943 } else
2944 ret = -EINVAL;
2945
2946 if (ret >= 0)
2947 netdev_state_change(tun->dev);
2948
2949 unlock:
2950 rtnl_unlock();
2951 return ret;
2952 }
2953
2954 static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog **prog_p,
2955 void __user *data)
2956 {
2957 struct bpf_prog *prog;
2958 int fd;
2959
2960 if (copy_from_user(&fd, data, sizeof(fd)))
2961 return -EFAULT;
2962
2963 if (fd == -1) {
2964 prog = NULL;
2965 } else {
2966 prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
2967 if (IS_ERR(prog))
2968 return PTR_ERR(prog);
2969 }
2970
2971 return __tun_set_ebpf(tun, prog_p, prog);
2972 }
2973
2974 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
2975 unsigned long arg, int ifreq_len)
2976 {
2977 struct tun_file *tfile = file->private_data;
2978 struct net *net = sock_net(&tfile->sk);
2979 struct tun_struct *tun;
2980 void __user* argp = (void __user*)arg;
2981 struct ifreq ifr;
2982 kuid_t owner;
2983 kgid_t group;
2984 int sndbuf;
2985 int vnet_hdr_sz;
2986 unsigned int ifindex;
2987 int le;
2988 int ret;
2989 bool do_notify = false;
2990
2991 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE ||
2992 (_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) {
2993 if (copy_from_user(&ifr, argp, ifreq_len))
2994 return -EFAULT;
2995 } else {
2996 memset(&ifr, 0, sizeof(ifr));
2997 }
2998 if (cmd == TUNGETFEATURES) {
2999 /* Currently this just means: "what IFF flags are valid?".
3000 * This is needed because we never checked for invalid flags on
3001 * TUNSETIFF.
3002 */
3003 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
3004 (unsigned int __user*)argp);
3005 } else if (cmd == TUNSETQUEUE) {
3006 return tun_set_queue(file, &ifr);
3007 } else if (cmd == SIOCGSKNS) {
3008 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3009 return -EPERM;
3010 return open_related_ns(&net->ns, get_net_ns);
3011 }
3012
3013 ret = 0;
3014 rtnl_lock();
3015
3016 tun = tun_get(tfile);
3017 if (cmd == TUNSETIFF) {
3018 ret = -EEXIST;
3019 if (tun)
3020 goto unlock;
3021
3022 ifr.ifr_name[IFNAMSIZ-1] = '\0';
3023
3024 ret = tun_set_iff(net, file, &ifr);
3025
3026 if (ret)
3027 goto unlock;
3028
3029 if (copy_to_user(argp, &ifr, ifreq_len))
3030 ret = -EFAULT;
3031 goto unlock;
3032 }
3033 if (cmd == TUNSETIFINDEX) {
3034 ret = -EPERM;
3035 if (tun)
3036 goto unlock;
3037
3038 ret = -EFAULT;
3039 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
3040 goto unlock;
3041
3042 ret = 0;
3043 tfile->ifindex = ifindex;
3044 goto unlock;
3045 }
3046
3047 ret = -EBADFD;
3048 if (!tun)
3049 goto unlock;
3050
3051 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
3052
3053 ret = 0;
3054 switch (cmd) {
3055 case TUNGETIFF:
3056 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
3057
3058 if (tfile->detached)
3059 ifr.ifr_flags |= IFF_DETACH_QUEUE;
3060 if (!tfile->socket.sk->sk_filter)
3061 ifr.ifr_flags |= IFF_NOFILTER;
3062
3063 if (copy_to_user(argp, &ifr, ifreq_len))
3064 ret = -EFAULT;
3065 break;
3066
3067 case TUNSETNOCSUM:
3068 /* Disable/Enable checksum */
3069
3070 /* [unimplemented] */
3071 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
3072 arg ? "disabled" : "enabled");
3073 break;
3074
3075 case TUNSETPERSIST:
3076 /* Disable/Enable persist mode. Keep an extra reference to the
3077 * module to prevent the module being unprobed.
3078 */
3079 if (arg && !(tun->flags & IFF_PERSIST)) {
3080 tun->flags |= IFF_PERSIST;
3081 __module_get(THIS_MODULE);
3082 do_notify = true;
3083 }
3084 if (!arg && (tun->flags & IFF_PERSIST)) {
3085 tun->flags &= ~IFF_PERSIST;
3086 module_put(THIS_MODULE);
3087 do_notify = true;
3088 }
3089
3090 tun_debug(KERN_INFO, tun, "persist %s\n",
3091 arg ? "enabled" : "disabled");
3092 break;
3093
3094 case TUNSETOWNER:
3095 /* Set owner of the device */
3096 owner = make_kuid(current_user_ns(), arg);
3097 if (!uid_valid(owner)) {
3098 ret = -EINVAL;
3099 break;
3100 }
3101 tun->owner = owner;
3102 do_notify = true;
3103 tun_debug(KERN_INFO, tun, "owner set to %u\n",
3104 from_kuid(&init_user_ns, tun->owner));
3105 break;
3106
3107 case TUNSETGROUP:
3108 /* Set group of the device */
3109 group = make_kgid(current_user_ns(), arg);
3110 if (!gid_valid(group)) {
3111 ret = -EINVAL;
3112 break;
3113 }
3114 tun->group = group;
3115 do_notify = true;
3116 tun_debug(KERN_INFO, tun, "group set to %u\n",
3117 from_kgid(&init_user_ns, tun->group));
3118 break;
3119
3120 case TUNSETLINK:
3121 /* Only allow setting the type when the interface is down */
3122 if (tun->dev->flags & IFF_UP) {
3123 tun_debug(KERN_INFO, tun,
3124 "Linktype set failed because interface is up\n");
3125 ret = -EBUSY;
3126 } else {
3127 tun->dev->type = (int) arg;
3128 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
3129 tun->dev->type);
3130 ret = 0;
3131 }
3132 break;
3133
3134 #ifdef TUN_DEBUG
3135 case TUNSETDEBUG:
3136 tun->debug = arg;
3137 break;
3138 #endif
3139 case TUNSETOFFLOAD:
3140 ret = set_offload(tun, arg);
3141 break;
3142
3143 case TUNSETTXFILTER:
3144 /* Can be set only for TAPs */
3145 ret = -EINVAL;
3146 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3147 break;
3148 ret = update_filter(&tun->txflt, (void __user *)arg);
3149 break;
3150
3151 case SIOCGIFHWADDR:
3152 /* Get hw address */
3153 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
3154 ifr.ifr_hwaddr.sa_family = tun->dev->type;
3155 if (copy_to_user(argp, &ifr, ifreq_len))
3156 ret = -EFAULT;
3157 break;
3158
3159 case SIOCSIFHWADDR:
3160 /* Set hw address */
3161 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
3162 ifr.ifr_hwaddr.sa_data);
3163
3164 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
3165 break;
3166
3167 case TUNGETSNDBUF:
3168 sndbuf = tfile->socket.sk->sk_sndbuf;
3169 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
3170 ret = -EFAULT;
3171 break;
3172
3173 case TUNSETSNDBUF:
3174 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
3175 ret = -EFAULT;
3176 break;
3177 }
3178 if (sndbuf <= 0) {
3179 ret = -EINVAL;
3180 break;
3181 }
3182
3183 tun->sndbuf = sndbuf;
3184 tun_set_sndbuf(tun);
3185 break;
3186
3187 case TUNGETVNETHDRSZ:
3188 vnet_hdr_sz = tun->vnet_hdr_sz;
3189 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
3190 ret = -EFAULT;
3191 break;
3192
3193 case TUNSETVNETHDRSZ:
3194 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
3195 ret = -EFAULT;
3196 break;
3197 }
3198 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
3199 ret = -EINVAL;
3200 break;
3201 }
3202
3203 tun->vnet_hdr_sz = vnet_hdr_sz;
3204 break;
3205
3206 case TUNGETVNETLE:
3207 le = !!(tun->flags & TUN_VNET_LE);
3208 if (put_user(le, (int __user *)argp))
3209 ret = -EFAULT;
3210 break;
3211
3212 case TUNSETVNETLE:
3213 if (get_user(le, (int __user *)argp)) {
3214 ret = -EFAULT;
3215 break;
3216 }
3217 if (le)
3218 tun->flags |= TUN_VNET_LE;
3219 else
3220 tun->flags &= ~TUN_VNET_LE;
3221 break;
3222
3223 case TUNGETVNETBE:
3224 ret = tun_get_vnet_be(tun, argp);
3225 break;
3226
3227 case TUNSETVNETBE:
3228 ret = tun_set_vnet_be(tun, argp);
3229 break;
3230
3231 case TUNATTACHFILTER:
3232 /* Can be set only for TAPs */
3233 ret = -EINVAL;
3234 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3235 break;
3236 ret = -EFAULT;
3237 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
3238 break;
3239
3240 ret = tun_attach_filter(tun);
3241 break;
3242
3243 case TUNDETACHFILTER:
3244 /* Can be set only for TAPs */
3245 ret = -EINVAL;
3246 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3247 break;
3248 ret = 0;
3249 tun_detach_filter(tun, tun->numqueues);
3250 break;
3251
3252 case TUNGETFILTER:
3253 ret = -EINVAL;
3254 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3255 break;
3256 ret = -EFAULT;
3257 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
3258 break;
3259 ret = 0;
3260 break;
3261
3262 case TUNSETSTEERINGEBPF:
3263 ret = tun_set_ebpf(tun, &tun->steering_prog, argp);
3264 break;
3265
3266 case TUNSETFILTEREBPF:
3267 ret = tun_set_ebpf(tun, &tun->filter_prog, argp);
3268 break;
3269
3270 default:
3271 ret = -EINVAL;
3272 break;
3273 }
3274
3275 if (do_notify)
3276 netdev_state_change(tun->dev);
3277
3278 unlock:
3279 rtnl_unlock();
3280 if (tun)
3281 tun_put(tun);
3282 return ret;
3283 }
3284
3285 static long tun_chr_ioctl(struct file *file,
3286 unsigned int cmd, unsigned long arg)
3287 {
3288 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
3289 }
3290
3291 #ifdef CONFIG_COMPAT
3292 static long tun_chr_compat_ioctl(struct file *file,
3293 unsigned int cmd, unsigned long arg)
3294 {
3295 switch (cmd) {
3296 case TUNSETIFF:
3297 case TUNGETIFF:
3298 case TUNSETTXFILTER:
3299 case TUNGETSNDBUF:
3300 case TUNSETSNDBUF:
3301 case SIOCGIFHWADDR:
3302 case SIOCSIFHWADDR:
3303 arg = (unsigned long)compat_ptr(arg);
3304 break;
3305 default:
3306 arg = (compat_ulong_t)arg;
3307 break;
3308 }
3309
3310 /*
3311 * compat_ifreq is shorter than ifreq, so we must not access beyond
3312 * the end of that structure. All fields that are used in this
3313 * driver are compatible though, we don't need to convert the
3314 * contents.
3315 */
3316 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
3317 }
3318 #endif /* CONFIG_COMPAT */
3319
3320 static int tun_chr_fasync(int fd, struct file *file, int on)
3321 {
3322 struct tun_file *tfile = file->private_data;
3323 int ret;
3324
3325 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
3326 goto out;
3327
3328 if (on) {
3329 __f_setown(file, task_pid(current), PIDTYPE_TGID, 0);
3330 tfile->flags |= TUN_FASYNC;
3331 } else
3332 tfile->flags &= ~TUN_FASYNC;
3333 ret = 0;
3334 out:
3335 return ret;
3336 }
3337
3338 static int tun_chr_open(struct inode *inode, struct file * file)
3339 {
3340 struct net *net = current->nsproxy->net_ns;
3341 struct tun_file *tfile;
3342
3343 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
3344
3345 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
3346 &tun_proto, 0);
3347 if (!tfile)
3348 return -ENOMEM;
3349 if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) {
3350 sk_free(&tfile->sk);
3351 return -ENOMEM;
3352 }
3353
3354 mutex_init(&tfile->napi_mutex);
3355 RCU_INIT_POINTER(tfile->tun, NULL);
3356 tfile->flags = 0;
3357 tfile->ifindex = 0;
3358
3359 init_waitqueue_head(&tfile->wq.wait);
3360 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
3361
3362 tfile->socket.file = file;
3363 tfile->socket.ops = &tun_socket_ops;
3364
3365 sock_init_data(&tfile->socket, &tfile->sk);
3366
3367 tfile->sk.sk_write_space = tun_sock_write_space;
3368 tfile->sk.sk_sndbuf = INT_MAX;
3369
3370 file->private_data = tfile;
3371 INIT_LIST_HEAD(&tfile->next);
3372
3373 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
3374
3375 return 0;
3376 }
3377
3378 static int tun_chr_close(struct inode *inode, struct file *file)
3379 {
3380 struct tun_file *tfile = file->private_data;
3381
3382 tun_detach(tfile, true);
3383
3384 return 0;
3385 }
3386
3387 #ifdef CONFIG_PROC_FS
3388 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file)
3389 {
3390 struct tun_file *tfile = file->private_data;
3391 struct tun_struct *tun;
3392 struct ifreq ifr;
3393
3394 memset(&ifr, 0, sizeof(ifr));
3395
3396 rtnl_lock();
3397 tun = tun_get(tfile);
3398 if (tun)
3399 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
3400 rtnl_unlock();
3401
3402 if (tun)
3403 tun_put(tun);
3404
3405 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
3406 }
3407 #endif
3408
3409 static const struct file_operations tun_fops = {
3410 .owner = THIS_MODULE,
3411 .llseek = no_llseek,
3412 .read_iter = tun_chr_read_iter,
3413 .write_iter = tun_chr_write_iter,
3414 .poll = tun_chr_poll,
3415 .unlocked_ioctl = tun_chr_ioctl,
3416 #ifdef CONFIG_COMPAT
3417 .compat_ioctl = tun_chr_compat_ioctl,
3418 #endif
3419 .open = tun_chr_open,
3420 .release = tun_chr_close,
3421 .fasync = tun_chr_fasync,
3422 #ifdef CONFIG_PROC_FS
3423 .show_fdinfo = tun_chr_show_fdinfo,
3424 #endif
3425 };
3426
3427 static struct miscdevice tun_miscdev = {
3428 .minor = TUN_MINOR,
3429 .name = "tun",
3430 .nodename = "net/tun",
3431 .fops = &tun_fops,
3432 };
3433
3434 /* ethtool interface */
3435
3436 static void tun_default_link_ksettings(struct net_device *dev,
3437 struct ethtool_link_ksettings *cmd)
3438 {
3439 ethtool_link_ksettings_zero_link_mode(cmd, supported);
3440 ethtool_link_ksettings_zero_link_mode(cmd, advertising);
3441 cmd->base.speed = SPEED_10;
3442 cmd->base.duplex = DUPLEX_FULL;
3443 cmd->base.port = PORT_TP;
3444 cmd->base.phy_address = 0;
3445 cmd->base.autoneg = AUTONEG_DISABLE;
3446 }
3447
3448 static int tun_get_link_ksettings(struct net_device *dev,
3449 struct ethtool_link_ksettings *cmd)
3450 {
3451 struct tun_struct *tun = netdev_priv(dev);
3452
3453 memcpy(cmd, &tun->link_ksettings, sizeof(*cmd));
3454 return 0;
3455 }
3456
3457 static int tun_set_link_ksettings(struct net_device *dev,
3458 const struct ethtool_link_ksettings *cmd)
3459 {
3460 struct tun_struct *tun = netdev_priv(dev);
3461
3462 memcpy(&tun->link_ksettings, cmd, sizeof(*cmd));
3463 return 0;
3464 }
3465
3466 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
3467 {
3468 struct tun_struct *tun = netdev_priv(dev);
3469
3470 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
3471 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
3472
3473 switch (tun->flags & TUN_TYPE_MASK) {
3474 case IFF_TUN:
3475 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
3476 break;
3477 case IFF_TAP:
3478 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
3479 break;
3480 }
3481 }
3482
3483 static u32 tun_get_msglevel(struct net_device *dev)
3484 {
3485 #ifdef TUN_DEBUG
3486 struct tun_struct *tun = netdev_priv(dev);
3487 return tun->debug;
3488 #else
3489 return -EOPNOTSUPP;
3490 #endif
3491 }
3492
3493 static void tun_set_msglevel(struct net_device *dev, u32 value)
3494 {
3495 #ifdef TUN_DEBUG
3496 struct tun_struct *tun = netdev_priv(dev);
3497 tun->debug = value;
3498 #endif
3499 }
3500
3501 static int tun_get_coalesce(struct net_device *dev,
3502 struct ethtool_coalesce *ec)
3503 {
3504 struct tun_struct *tun = netdev_priv(dev);
3505
3506 ec->rx_max_coalesced_frames = tun->rx_batched;
3507
3508 return 0;
3509 }
3510
3511 static int tun_set_coalesce(struct net_device *dev,
3512 struct ethtool_coalesce *ec)
3513 {
3514 struct tun_struct *tun = netdev_priv(dev);
3515
3516 if (ec->rx_max_coalesced_frames > NAPI_POLL_WEIGHT)
3517 tun->rx_batched = NAPI_POLL_WEIGHT;
3518 else
3519 tun->rx_batched = ec->rx_max_coalesced_frames;
3520
3521 return 0;
3522 }
3523
3524 static const struct ethtool_ops tun_ethtool_ops = {
3525 .get_drvinfo = tun_get_drvinfo,
3526 .get_msglevel = tun_get_msglevel,
3527 .set_msglevel = tun_set_msglevel,
3528 .get_link = ethtool_op_get_link,
3529 .get_ts_info = ethtool_op_get_ts_info,
3530 .get_coalesce = tun_get_coalesce,
3531 .set_coalesce = tun_set_coalesce,
3532 .get_link_ksettings = tun_get_link_ksettings,
3533 .set_link_ksettings = tun_set_link_ksettings,
3534 };
3535
3536 static int tun_queue_resize(struct tun_struct *tun)
3537 {
3538 struct net_device *dev = tun->dev;
3539 struct tun_file *tfile;
3540 struct ptr_ring **rings;
3541 int n = tun->numqueues + tun->numdisabled;
3542 int ret, i;
3543
3544 rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL);
3545 if (!rings)
3546 return -ENOMEM;
3547
3548 for (i = 0; i < tun->numqueues; i++) {
3549 tfile = rtnl_dereference(tun->tfiles[i]);
3550 rings[i] = &tfile->tx_ring;
3551 }
3552 list_for_each_entry(tfile, &tun->disabled, next)
3553 rings[i++] = &tfile->tx_ring;
3554
3555 ret = ptr_ring_resize_multiple(rings, n,
3556 dev->tx_queue_len, GFP_KERNEL,
3557 tun_ptr_free);
3558
3559 kfree(rings);
3560 return ret;
3561 }
3562
3563 static int tun_device_event(struct notifier_block *unused,
3564 unsigned long event, void *ptr)
3565 {
3566 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3567 struct tun_struct *tun = netdev_priv(dev);
3568
3569 if (dev->rtnl_link_ops != &tun_link_ops)
3570 return NOTIFY_DONE;
3571
3572 switch (event) {
3573 case NETDEV_CHANGE_TX_QUEUE_LEN:
3574 if (tun_queue_resize(tun))
3575 return NOTIFY_BAD;
3576 break;
3577 default:
3578 break;
3579 }
3580
3581 return NOTIFY_DONE;
3582 }
3583
3584 static struct notifier_block tun_notifier_block __read_mostly = {
3585 .notifier_call = tun_device_event,
3586 };
3587
3588 static int __init tun_init(void)
3589 {
3590 int ret = 0;
3591
3592 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
3593
3594 ret = rtnl_link_register(&tun_link_ops);
3595 if (ret) {
3596 pr_err("Can't register link_ops\n");
3597 goto err_linkops;
3598 }
3599
3600 ret = misc_register(&tun_miscdev);
3601 if (ret) {
3602 pr_err("Can't register misc device %d\n", TUN_MINOR);
3603 goto err_misc;
3604 }
3605
3606 ret = register_netdevice_notifier(&tun_notifier_block);
3607 if (ret) {
3608 pr_err("Can't register netdevice notifier\n");
3609 goto err_notifier;
3610 }
3611
3612 return 0;
3613
3614 err_notifier:
3615 misc_deregister(&tun_miscdev);
3616 err_misc:
3617 rtnl_link_unregister(&tun_link_ops);
3618 err_linkops:
3619 return ret;
3620 }
3621
3622 static void tun_cleanup(void)
3623 {
3624 misc_deregister(&tun_miscdev);
3625 rtnl_link_unregister(&tun_link_ops);
3626 unregister_netdevice_notifier(&tun_notifier_block);
3627 }
3628
3629 /* Get an underlying socket object from tun file. Returns error unless file is
3630 * attached to a device. The returned object works like a packet socket, it
3631 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
3632 * holding a reference to the file for as long as the socket is in use. */
3633 struct socket *tun_get_socket(struct file *file)
3634 {
3635 struct tun_file *tfile;
3636 if (file->f_op != &tun_fops)
3637 return ERR_PTR(-EINVAL);
3638 tfile = file->private_data;
3639 if (!tfile)
3640 return ERR_PTR(-EBADFD);
3641 return &tfile->socket;
3642 }
3643 EXPORT_SYMBOL_GPL(tun_get_socket);
3644
3645 struct ptr_ring *tun_get_tx_ring(struct file *file)
3646 {
3647 struct tun_file *tfile;
3648
3649 if (file->f_op != &tun_fops)
3650 return ERR_PTR(-EINVAL);
3651 tfile = file->private_data;
3652 if (!tfile)
3653 return ERR_PTR(-EBADFD);
3654 return &tfile->tx_ring;
3655 }
3656 EXPORT_SYMBOL_GPL(tun_get_tx_ring);
3657
3658 module_init(tun_init);
3659 module_exit(tun_cleanup);
3660 MODULE_DESCRIPTION(DRV_DESCRIPTION);
3661 MODULE_AUTHOR(DRV_COPYRIGHT);
3662 MODULE_LICENSE("GPL");
3663 MODULE_ALIAS_MISCDEV(TUN_MINOR);
3664 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support