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perf tools: Don't clone maps from parent when synthesizing forks
[linux/fpc-iii.git] / drivers / net / tun.c
blob060135ceaf0e1a76615b2e6cd6830d42ac8becdf
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 netif_receive_skb(skb);
1540 local_bh_enable();
1541 return;
1542 }
1543
1544 spin_lock(&queue->lock);
1545 if (!more || skb_queue_len(queue) == rx_batched) {
1546 __skb_queue_head_init(&process_queue);
1547 skb_queue_splice_tail_init(queue, &process_queue);
1548 rcv = true;
1549 } else {
1550 __skb_queue_tail(queue, skb);
1551 }
1552 spin_unlock(&queue->lock);
1553
1554 if (rcv) {
1555 struct sk_buff *nskb;
1556
1557 local_bh_disable();
1558 while ((nskb = __skb_dequeue(&process_queue)))
1559 netif_receive_skb(nskb);
1560 netif_receive_skb(skb);
1561 local_bh_enable();
1562 }
1563 }
1564
1565 static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
1566 int len, int noblock, bool zerocopy)
1567 {
1568 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
1569 return false;
1570
1571 if (tfile->socket.sk->sk_sndbuf != INT_MAX)
1572 return false;
1573
1574 if (!noblock)
1575 return false;
1576
1577 if (zerocopy)
1578 return false;
1579
1580 if (SKB_DATA_ALIGN(len + TUN_RX_PAD) +
1581 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
1582 return false;
1583
1584 return true;
1585 }
1586
1587 static struct sk_buff *__tun_build_skb(struct page_frag *alloc_frag, char *buf,
1588 int buflen, int len, int pad)
1589 {
1590 struct sk_buff *skb = build_skb(buf, buflen);
1591
1592 if (!skb)
1593 return ERR_PTR(-ENOMEM);
1594
1595 skb_reserve(skb, pad);
1596 skb_put(skb, len);
1597
1598 get_page(alloc_frag->page);
1599 alloc_frag->offset += buflen;
1600
1601 return skb;
1602 }
1603
1604 static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog,
1605 struct xdp_buff *xdp, u32 act)
1606 {
1607 int err;
1608
1609 switch (act) {
1610 case XDP_REDIRECT:
1611 err = xdp_do_redirect(tun->dev, xdp, xdp_prog);
1612 if (err)
1613 return err;
1614 break;
1615 case XDP_TX:
1616 err = tun_xdp_tx(tun->dev, xdp);
1617 if (err < 0)
1618 return err;
1619 break;
1620 case XDP_PASS:
1621 break;
1622 default:
1623 bpf_warn_invalid_xdp_action(act);
1624 /* fall through */
1625 case XDP_ABORTED:
1626 trace_xdp_exception(tun->dev, xdp_prog, act);
1627 /* fall through */
1628 case XDP_DROP:
1629 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1630 break;
1631 }
1632
1633 return act;
1634 }
1635
1636 static struct sk_buff *tun_build_skb(struct tun_struct *tun,
1637 struct tun_file *tfile,
1638 struct iov_iter *from,
1639 struct virtio_net_hdr *hdr,
1640 int len, int *skb_xdp)
1641 {
1642 struct page_frag *alloc_frag = &current->task_frag;
1643 struct bpf_prog *xdp_prog;
1644 int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1645 char *buf;
1646 size_t copied;
1647 int pad = TUN_RX_PAD;
1648 int err = 0;
1649
1650 rcu_read_lock();
1651 xdp_prog = rcu_dereference(tun->xdp_prog);
1652 if (xdp_prog)
1653 pad += XDP_PACKET_HEADROOM;
1654 buflen += SKB_DATA_ALIGN(len + pad);
1655 rcu_read_unlock();
1656
1657 alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
1658 if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
1659 return ERR_PTR(-ENOMEM);
1660
1661 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1662 copied = copy_page_from_iter(alloc_frag->page,
1663 alloc_frag->offset + pad,
1664 len, from);
1665 if (copied != len)
1666 return ERR_PTR(-EFAULT);
1667
1668 /* There's a small window that XDP may be set after the check
1669 * of xdp_prog above, this should be rare and for simplicity
1670 * we do XDP on skb in case the headroom is not enough.
1671 */
1672 if (hdr->gso_type || !xdp_prog) {
1673 *skb_xdp = 1;
1674 return __tun_build_skb(alloc_frag, buf, buflen, len, pad);
1675 }
1676
1677 *skb_xdp = 0;
1678
1679 local_bh_disable();
1680 rcu_read_lock();
1681 xdp_prog = rcu_dereference(tun->xdp_prog);
1682 if (xdp_prog) {
1683 struct xdp_buff xdp;
1684 u32 act;
1685
1686 xdp.data_hard_start = buf;
1687 xdp.data = buf + pad;
1688 xdp_set_data_meta_invalid(&xdp);
1689 xdp.data_end = xdp.data + len;
1690 xdp.rxq = &tfile->xdp_rxq;
1691
1692 act = bpf_prog_run_xdp(xdp_prog, &xdp);
1693 if (act == XDP_REDIRECT || act == XDP_TX) {
1694 get_page(alloc_frag->page);
1695 alloc_frag->offset += buflen;
1696 }
1697 err = tun_xdp_act(tun, xdp_prog, &xdp, act);
1698 if (err < 0)
1699 goto err_xdp;
1700 if (err == XDP_REDIRECT)
1701 xdp_do_flush_map();
1702 if (err != XDP_PASS)
1703 goto out;
1704
1705 pad = xdp.data - xdp.data_hard_start;
1706 len = xdp.data_end - xdp.data;
1707 }
1708 rcu_read_unlock();
1709 local_bh_enable();
1710
1711 return __tun_build_skb(alloc_frag, buf, buflen, len, pad);
1712
1713 err_xdp:
1714 put_page(alloc_frag->page);
1715 out:
1716 rcu_read_unlock();
1717 local_bh_enable();
1718 return NULL;
1719 }
1720
1721 /* Get packet from user space buffer */
1722 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1723 void *msg_control, struct iov_iter *from,
1724 int noblock, bool more)
1725 {
1726 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1727 struct sk_buff *skb;
1728 size_t total_len = iov_iter_count(from);
1729 size_t len = total_len, align = tun->align, linear;
1730 struct virtio_net_hdr gso = { 0 };
1731 struct tun_pcpu_stats *stats;
1732 int good_linear;
1733 int copylen;
1734 bool zerocopy = false;
1735 int err;
1736 u32 rxhash = 0;
1737 int skb_xdp = 1;
1738 bool frags = tun_napi_frags_enabled(tfile);
1739
1740 if (!(tun->dev->flags & IFF_UP))
1741 return -EIO;
1742
1743 if (!(tun->flags & IFF_NO_PI)) {
1744 if (len < sizeof(pi))
1745 return -EINVAL;
1746 len -= sizeof(pi);
1747
1748 if (!copy_from_iter_full(&pi, sizeof(pi), from))
1749 return -EFAULT;
1750 }
1751
1752 if (tun->flags & IFF_VNET_HDR) {
1753 int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
1754
1755 if (len < vnet_hdr_sz)
1756 return -EINVAL;
1757 len -= vnet_hdr_sz;
1758
1759 if (!copy_from_iter_full(&gso, sizeof(gso), from))
1760 return -EFAULT;
1761
1762 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1763 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1764 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1765
1766 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1767 return -EINVAL;
1768 iov_iter_advance(from, vnet_hdr_sz - sizeof(gso));
1769 }
1770
1771 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1772 align += NET_IP_ALIGN;
1773 if (unlikely(len < ETH_HLEN ||
1774 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1775 return -EINVAL;
1776 }
1777
1778 good_linear = SKB_MAX_HEAD(align);
1779
1780 if (msg_control) {
1781 struct iov_iter i = *from;
1782
1783 /* There are 256 bytes to be copied in skb, so there is
1784 * enough room for skb expand head in case it is used.
1785 * The rest of the buffer is mapped from userspace.
1786 */
1787 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1788 if (copylen > good_linear)
1789 copylen = good_linear;
1790 linear = copylen;
1791 iov_iter_advance(&i, copylen);
1792 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1793 zerocopy = true;
1794 }
1795
1796 if (!frags && tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) {
1797 /* For the packet that is not easy to be processed
1798 * (e.g gso or jumbo packet), we will do it at after
1799 * skb was created with generic XDP routine.
1800 */
1801 skb = tun_build_skb(tun, tfile, from, &gso, len, &skb_xdp);
1802 if (IS_ERR(skb)) {
1803 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1804 return PTR_ERR(skb);
1805 }
1806 if (!skb)
1807 return total_len;
1808 } else {
1809 if (!zerocopy) {
1810 copylen = len;
1811 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1812 linear = good_linear;
1813 else
1814 linear = tun16_to_cpu(tun, gso.hdr_len);
1815 }
1816
1817 if (frags) {
1818 mutex_lock(&tfile->napi_mutex);
1819 skb = tun_napi_alloc_frags(tfile, copylen, from);
1820 /* tun_napi_alloc_frags() enforces a layout for the skb.
1821 * If zerocopy is enabled, then this layout will be
1822 * overwritten by zerocopy_sg_from_iter().
1823 */
1824 zerocopy = false;
1825 } else {
1826 skb = tun_alloc_skb(tfile, align, copylen, linear,
1827 noblock);
1828 }
1829
1830 if (IS_ERR(skb)) {
1831 if (PTR_ERR(skb) != -EAGAIN)
1832 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1833 if (frags)
1834 mutex_unlock(&tfile->napi_mutex);
1835 return PTR_ERR(skb);
1836 }
1837
1838 if (zerocopy)
1839 err = zerocopy_sg_from_iter(skb, from);
1840 else
1841 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1842
1843 if (err) {
1844 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1845 kfree_skb(skb);
1846 if (frags) {
1847 tfile->napi.skb = NULL;
1848 mutex_unlock(&tfile->napi_mutex);
1849 }
1850
1851 return -EFAULT;
1852 }
1853 }
1854
1855 if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) {
1856 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
1857 kfree_skb(skb);
1858 if (frags) {
1859 tfile->napi.skb = NULL;
1860 mutex_unlock(&tfile->napi_mutex);
1861 }
1862
1863 return -EINVAL;
1864 }
1865
1866 switch (tun->flags & TUN_TYPE_MASK) {
1867 case IFF_TUN:
1868 if (tun->flags & IFF_NO_PI) {
1869 u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0;
1870
1871 switch (ip_version) {
1872 case 4:
1873 pi.proto = htons(ETH_P_IP);
1874 break;
1875 case 6:
1876 pi.proto = htons(ETH_P_IPV6);
1877 break;
1878 default:
1879 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1880 kfree_skb(skb);
1881 return -EINVAL;
1882 }
1883 }
1884
1885 skb_reset_mac_header(skb);
1886 skb->protocol = pi.proto;
1887 skb->dev = tun->dev;
1888 break;
1889 case IFF_TAP:
1890 if (!frags)
1891 skb->protocol = eth_type_trans(skb, tun->dev);
1892 break;
1893 }
1894
1895 /* copy skb_ubuf_info for callback when skb has no error */
1896 if (zerocopy) {
1897 skb_shinfo(skb)->destructor_arg = msg_control;
1898 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1899 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1900 } else if (msg_control) {
1901 struct ubuf_info *uarg = msg_control;
1902 uarg->callback(uarg, false);
1903 }
1904
1905 skb_reset_network_header(skb);
1906 skb_probe_transport_header(skb, 0);
1907
1908 if (skb_xdp) {
1909 struct bpf_prog *xdp_prog;
1910 int ret;
1911
1912 local_bh_disable();
1913 rcu_read_lock();
1914 xdp_prog = rcu_dereference(tun->xdp_prog);
1915 if (xdp_prog) {
1916 ret = do_xdp_generic(xdp_prog, skb);
1917 if (ret != XDP_PASS) {
1918 rcu_read_unlock();
1919 local_bh_enable();
1920 return total_len;
1921 }
1922 }
1923 rcu_read_unlock();
1924 local_bh_enable();
1925 }
1926
1927 /* Compute the costly rx hash only if needed for flow updates.
1928 * We may get a very small possibility of OOO during switching, not
1929 * worth to optimize.
1930 */
1931 if (!rcu_access_pointer(tun->steering_prog) && tun->numqueues > 1 &&
1932 !tfile->detached)
1933 rxhash = __skb_get_hash_symmetric(skb);
1934
1935 if (frags) {
1936 /* Exercise flow dissector code path. */
1937 u32 headlen = eth_get_headlen(skb->data, skb_headlen(skb));
1938
1939 if (unlikely(headlen > skb_headlen(skb))) {
1940 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1941 napi_free_frags(&tfile->napi);
1942 mutex_unlock(&tfile->napi_mutex);
1943 WARN_ON(1);
1944 return -ENOMEM;
1945 }
1946
1947 local_bh_disable();
1948 napi_gro_frags(&tfile->napi);
1949 local_bh_enable();
1950 mutex_unlock(&tfile->napi_mutex);
1951 } else if (tfile->napi_enabled) {
1952 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1953 int queue_len;
1954
1955 spin_lock_bh(&queue->lock);
1956 __skb_queue_tail(queue, skb);
1957 queue_len = skb_queue_len(queue);
1958 spin_unlock(&queue->lock);
1959
1960 if (!more || queue_len > NAPI_POLL_WEIGHT)
1961 napi_schedule(&tfile->napi);
1962
1963 local_bh_enable();
1964 } else if (!IS_ENABLED(CONFIG_4KSTACKS)) {
1965 tun_rx_batched(tun, tfile, skb, more);
1966 } else {
1967 netif_rx_ni(skb);
1968 }
1969
1970 stats = get_cpu_ptr(tun->pcpu_stats);
1971 u64_stats_update_begin(&stats->syncp);
1972 stats->rx_packets++;
1973 stats->rx_bytes += len;
1974 u64_stats_update_end(&stats->syncp);
1975 put_cpu_ptr(stats);
1976
1977 if (rxhash)
1978 tun_flow_update(tun, rxhash, tfile);
1979
1980 return total_len;
1981 }
1982
1983 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1984 {
1985 struct file *file = iocb->ki_filp;
1986 struct tun_file *tfile = file->private_data;
1987 struct tun_struct *tun = tun_get(tfile);
1988 ssize_t result;
1989
1990 if (!tun)
1991 return -EBADFD;
1992
1993 result = tun_get_user(tun, tfile, NULL, from,
1994 file->f_flags & O_NONBLOCK, false);
1995
1996 tun_put(tun);
1997 return result;
1998 }
1999
2000 static ssize_t tun_put_user_xdp(struct tun_struct *tun,
2001 struct tun_file *tfile,
2002 struct xdp_frame *xdp_frame,
2003 struct iov_iter *iter)
2004 {
2005 int vnet_hdr_sz = 0;
2006 size_t size = xdp_frame->len;
2007 struct tun_pcpu_stats *stats;
2008 size_t ret;
2009
2010 if (tun->flags & IFF_VNET_HDR) {
2011 struct virtio_net_hdr gso = { 0 };
2012
2013 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2014 if (unlikely(iov_iter_count(iter) < vnet_hdr_sz))
2015 return -EINVAL;
2016 if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) !=
2017 sizeof(gso)))
2018 return -EFAULT;
2019 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2020 }
2021
2022 ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
2023
2024 stats = get_cpu_ptr(tun->pcpu_stats);
2025 u64_stats_update_begin(&stats->syncp);
2026 stats->tx_packets++;
2027 stats->tx_bytes += ret;
2028 u64_stats_update_end(&stats->syncp);
2029 put_cpu_ptr(tun->pcpu_stats);
2030
2031 return ret;
2032 }
2033
2034 /* Put packet to the user space buffer */
2035 static ssize_t tun_put_user(struct tun_struct *tun,
2036 struct tun_file *tfile,
2037 struct sk_buff *skb,
2038 struct iov_iter *iter)
2039 {
2040 struct tun_pi pi = { 0, skb->protocol };
2041 struct tun_pcpu_stats *stats;
2042 ssize_t total;
2043 int vlan_offset = 0;
2044 int vlan_hlen = 0;
2045 int vnet_hdr_sz = 0;
2046
2047 if (skb_vlan_tag_present(skb))
2048 vlan_hlen = VLAN_HLEN;
2049
2050 if (tun->flags & IFF_VNET_HDR)
2051 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2052
2053 total = skb->len + vlan_hlen + vnet_hdr_sz;
2054
2055 if (!(tun->flags & IFF_NO_PI)) {
2056 if (iov_iter_count(iter) < sizeof(pi))
2057 return -EINVAL;
2058
2059 total += sizeof(pi);
2060 if (iov_iter_count(iter) < total) {
2061 /* Packet will be striped */
2062 pi.flags |= TUN_PKT_STRIP;
2063 }
2064
2065 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
2066 return -EFAULT;
2067 }
2068
2069 if (vnet_hdr_sz) {
2070 struct virtio_net_hdr gso;
2071
2072 if (iov_iter_count(iter) < vnet_hdr_sz)
2073 return -EINVAL;
2074
2075 if (virtio_net_hdr_from_skb(skb, &gso,
2076 tun_is_little_endian(tun), true,
2077 vlan_hlen)) {
2078 struct skb_shared_info *sinfo = skb_shinfo(skb);
2079 pr_err("unexpected GSO type: "
2080 "0x%x, gso_size %d, hdr_len %d\n",
2081 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
2082 tun16_to_cpu(tun, gso.hdr_len));
2083 print_hex_dump(KERN_ERR, "tun: ",
2084 DUMP_PREFIX_NONE,
2085 16, 1, skb->head,
2086 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
2087 WARN_ON_ONCE(1);
2088 return -EINVAL;
2089 }
2090
2091 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
2092 return -EFAULT;
2093
2094 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2095 }
2096
2097 if (vlan_hlen) {
2098 int ret;
2099 struct veth veth;
2100
2101 veth.h_vlan_proto = skb->vlan_proto;
2102 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
2103
2104 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
2105
2106 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
2107 if (ret || !iov_iter_count(iter))
2108 goto done;
2109
2110 ret = copy_to_iter(&veth, sizeof(veth), iter);
2111 if (ret != sizeof(veth) || !iov_iter_count(iter))
2112 goto done;
2113 }
2114
2115 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
2116
2117 done:
2118 /* caller is in process context, */
2119 stats = get_cpu_ptr(tun->pcpu_stats);
2120 u64_stats_update_begin(&stats->syncp);
2121 stats->tx_packets++;
2122 stats->tx_bytes += skb->len + vlan_hlen;
2123 u64_stats_update_end(&stats->syncp);
2124 put_cpu_ptr(tun->pcpu_stats);
2125
2126 return total;
2127 }
2128
2129 static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
2130 {
2131 DECLARE_WAITQUEUE(wait, current);
2132 void *ptr = NULL;
2133 int error = 0;
2134
2135 ptr = ptr_ring_consume(&tfile->tx_ring);
2136 if (ptr)
2137 goto out;
2138 if (noblock) {
2139 error = -EAGAIN;
2140 goto out;
2141 }
2142
2143 add_wait_queue(&tfile->wq.wait, &wait);
2144 current->state = TASK_INTERRUPTIBLE;
2145
2146 while (1) {
2147 ptr = ptr_ring_consume(&tfile->tx_ring);
2148 if (ptr)
2149 break;
2150 if (signal_pending(current)) {
2151 error = -ERESTARTSYS;
2152 break;
2153 }
2154 if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
2155 error = -EFAULT;
2156 break;
2157 }
2158
2159 schedule();
2160 }
2161
2162 current->state = TASK_RUNNING;
2163 remove_wait_queue(&tfile->wq.wait, &wait);
2164
2165 out:
2166 *err = error;
2167 return ptr;
2168 }
2169
2170 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
2171 struct iov_iter *to,
2172 int noblock, void *ptr)
2173 {
2174 ssize_t ret;
2175 int err;
2176
2177 tun_debug(KERN_INFO, tun, "tun_do_read\n");
2178
2179 if (!iov_iter_count(to)) {
2180 tun_ptr_free(ptr);
2181 return 0;
2182 }
2183
2184 if (!ptr) {
2185 /* Read frames from ring */
2186 ptr = tun_ring_recv(tfile, noblock, &err);
2187 if (!ptr)
2188 return err;
2189 }
2190
2191 if (tun_is_xdp_frame(ptr)) {
2192 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2193
2194 ret = tun_put_user_xdp(tun, tfile, xdpf, to);
2195 xdp_return_frame(xdpf);
2196 } else {
2197 struct sk_buff *skb = ptr;
2198
2199 ret = tun_put_user(tun, tfile, skb, to);
2200 if (unlikely(ret < 0))
2201 kfree_skb(skb);
2202 else
2203 consume_skb(skb);
2204 }
2205
2206 return ret;
2207 }
2208
2209 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
2210 {
2211 struct file *file = iocb->ki_filp;
2212 struct tun_file *tfile = file->private_data;
2213 struct tun_struct *tun = tun_get(tfile);
2214 ssize_t len = iov_iter_count(to), ret;
2215
2216 if (!tun)
2217 return -EBADFD;
2218 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL);
2219 ret = min_t(ssize_t, ret, len);
2220 if (ret > 0)
2221 iocb->ki_pos = ret;
2222 tun_put(tun);
2223 return ret;
2224 }
2225
2226 static void tun_prog_free(struct rcu_head *rcu)
2227 {
2228 struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu);
2229
2230 bpf_prog_destroy(prog->prog);
2231 kfree(prog);
2232 }
2233
2234 static int __tun_set_ebpf(struct tun_struct *tun,
2235 struct tun_prog __rcu **prog_p,
2236 struct bpf_prog *prog)
2237 {
2238 struct tun_prog *old, *new = NULL;
2239
2240 if (prog) {
2241 new = kmalloc(sizeof(*new), GFP_KERNEL);
2242 if (!new)
2243 return -ENOMEM;
2244 new->prog = prog;
2245 }
2246
2247 spin_lock_bh(&tun->lock);
2248 old = rcu_dereference_protected(*prog_p,
2249 lockdep_is_held(&tun->lock));
2250 rcu_assign_pointer(*prog_p, new);
2251 spin_unlock_bh(&tun->lock);
2252
2253 if (old)
2254 call_rcu(&old->rcu, tun_prog_free);
2255
2256 return 0;
2257 }
2258
2259 static void tun_free_netdev(struct net_device *dev)
2260 {
2261 struct tun_struct *tun = netdev_priv(dev);
2262
2263 BUG_ON(!(list_empty(&tun->disabled)));
2264 free_percpu(tun->pcpu_stats);
2265 tun_flow_uninit(tun);
2266 security_tun_dev_free_security(tun->security);
2267 __tun_set_ebpf(tun, &tun->steering_prog, NULL);
2268 __tun_set_ebpf(tun, &tun->filter_prog, NULL);
2269 }
2270
2271 static void tun_setup(struct net_device *dev)
2272 {
2273 struct tun_struct *tun = netdev_priv(dev);
2274
2275 tun->owner = INVALID_UID;
2276 tun->group = INVALID_GID;
2277 tun_default_link_ksettings(dev, &tun->link_ksettings);
2278
2279 dev->ethtool_ops = &tun_ethtool_ops;
2280 dev->needs_free_netdev = true;
2281 dev->priv_destructor = tun_free_netdev;
2282 /* We prefer our own queue length */
2283 dev->tx_queue_len = TUN_READQ_SIZE;
2284 }
2285
2286 /* Trivial set of netlink ops to allow deleting tun or tap
2287 * device with netlink.
2288 */
2289 static int tun_validate(struct nlattr *tb[], struct nlattr *data[],
2290 struct netlink_ext_ack *extack)
2291 {
2292 if (!data)
2293 return 0;
2294 return -EINVAL;
2295 }
2296
2297 static size_t tun_get_size(const struct net_device *dev)
2298 {
2299 BUILD_BUG_ON(sizeof(u32) != sizeof(uid_t));
2300 BUILD_BUG_ON(sizeof(u32) != sizeof(gid_t));
2301
2302 return nla_total_size(sizeof(uid_t)) + /* OWNER */
2303 nla_total_size(sizeof(gid_t)) + /* GROUP */
2304 nla_total_size(sizeof(u8)) + /* TYPE */
2305 nla_total_size(sizeof(u8)) + /* PI */
2306 nla_total_size(sizeof(u8)) + /* VNET_HDR */
2307 nla_total_size(sizeof(u8)) + /* PERSIST */
2308 nla_total_size(sizeof(u8)) + /* MULTI_QUEUE */
2309 nla_total_size(sizeof(u32)) + /* NUM_QUEUES */
2310 nla_total_size(sizeof(u32)) + /* NUM_DISABLED_QUEUES */
2311 0;
2312 }
2313
2314 static int tun_fill_info(struct sk_buff *skb, const struct net_device *dev)
2315 {
2316 struct tun_struct *tun = netdev_priv(dev);
2317
2318 if (nla_put_u8(skb, IFLA_TUN_TYPE, tun->flags & TUN_TYPE_MASK))
2319 goto nla_put_failure;
2320 if (uid_valid(tun->owner) &&
2321 nla_put_u32(skb, IFLA_TUN_OWNER,
2322 from_kuid_munged(current_user_ns(), tun->owner)))
2323 goto nla_put_failure;
2324 if (gid_valid(tun->group) &&
2325 nla_put_u32(skb, IFLA_TUN_GROUP,
2326 from_kgid_munged(current_user_ns(), tun->group)))
2327 goto nla_put_failure;
2328 if (nla_put_u8(skb, IFLA_TUN_PI, !(tun->flags & IFF_NO_PI)))
2329 goto nla_put_failure;
2330 if (nla_put_u8(skb, IFLA_TUN_VNET_HDR, !!(tun->flags & IFF_VNET_HDR)))
2331 goto nla_put_failure;
2332 if (nla_put_u8(skb, IFLA_TUN_PERSIST, !!(tun->flags & IFF_PERSIST)))
2333 goto nla_put_failure;
2334 if (nla_put_u8(skb, IFLA_TUN_MULTI_QUEUE,
2335 !!(tun->flags & IFF_MULTI_QUEUE)))
2336 goto nla_put_failure;
2337 if (tun->flags & IFF_MULTI_QUEUE) {
2338 if (nla_put_u32(skb, IFLA_TUN_NUM_QUEUES, tun->numqueues))
2339 goto nla_put_failure;
2340 if (nla_put_u32(skb, IFLA_TUN_NUM_DISABLED_QUEUES,
2341 tun->numdisabled))
2342 goto nla_put_failure;
2343 }
2344
2345 return 0;
2346
2347 nla_put_failure:
2348 return -EMSGSIZE;
2349 }
2350
2351 static struct rtnl_link_ops tun_link_ops __read_mostly = {
2352 .kind = DRV_NAME,
2353 .priv_size = sizeof(struct tun_struct),
2354 .setup = tun_setup,
2355 .validate = tun_validate,
2356 .get_size = tun_get_size,
2357 .fill_info = tun_fill_info,
2358 };
2359
2360 static void tun_sock_write_space(struct sock *sk)
2361 {
2362 struct tun_file *tfile;
2363 wait_queue_head_t *wqueue;
2364
2365 if (!sock_writeable(sk))
2366 return;
2367
2368 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
2369 return;
2370
2371 wqueue = sk_sleep(sk);
2372 if (wqueue && waitqueue_active(wqueue))
2373 wake_up_interruptible_sync_poll(wqueue, EPOLLOUT |
2374 EPOLLWRNORM | EPOLLWRBAND);
2375
2376 tfile = container_of(sk, struct tun_file, sk);
2377 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
2378 }
2379
2380 static int tun_xdp_one(struct tun_struct *tun,
2381 struct tun_file *tfile,
2382 struct xdp_buff *xdp, int *flush)
2383 {
2384 struct tun_xdp_hdr *hdr = xdp->data_hard_start;
2385 struct virtio_net_hdr *gso = &hdr->gso;
2386 struct tun_pcpu_stats *stats;
2387 struct bpf_prog *xdp_prog;
2388 struct sk_buff *skb = NULL;
2389 u32 rxhash = 0, act;
2390 int buflen = hdr->buflen;
2391 int err = 0;
2392 bool skb_xdp = false;
2393
2394 xdp_prog = rcu_dereference(tun->xdp_prog);
2395 if (xdp_prog) {
2396 if (gso->gso_type) {
2397 skb_xdp = true;
2398 goto build;
2399 }
2400 xdp_set_data_meta_invalid(xdp);
2401 xdp->rxq = &tfile->xdp_rxq;
2402
2403 act = bpf_prog_run_xdp(xdp_prog, xdp);
2404 err = tun_xdp_act(tun, xdp_prog, xdp, act);
2405 if (err < 0) {
2406 put_page(virt_to_head_page(xdp->data));
2407 return err;
2408 }
2409
2410 switch (err) {
2411 case XDP_REDIRECT:
2412 *flush = true;
2413 /* fall through */
2414 case XDP_TX:
2415 return 0;
2416 case XDP_PASS:
2417 break;
2418 default:
2419 put_page(virt_to_head_page(xdp->data));
2420 return 0;
2421 }
2422 }
2423
2424 build:
2425 skb = build_skb(xdp->data_hard_start, buflen);
2426 if (!skb) {
2427 err = -ENOMEM;
2428 goto out;
2429 }
2430
2431 skb_reserve(skb, xdp->data - xdp->data_hard_start);
2432 skb_put(skb, xdp->data_end - xdp->data);
2433
2434 if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) {
2435 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
2436 kfree_skb(skb);
2437 err = -EINVAL;
2438 goto out;
2439 }
2440
2441 skb->protocol = eth_type_trans(skb, tun->dev);
2442 skb_reset_network_header(skb);
2443 skb_probe_transport_header(skb, 0);
2444
2445 if (skb_xdp) {
2446 err = do_xdp_generic(xdp_prog, skb);
2447 if (err != XDP_PASS)
2448 goto out;
2449 }
2450
2451 if (!rcu_dereference(tun->steering_prog))
2452 rxhash = __skb_get_hash_symmetric(skb);
2453
2454 netif_receive_skb(skb);
2455
2456 stats = get_cpu_ptr(tun->pcpu_stats);
2457 u64_stats_update_begin(&stats->syncp);
2458 stats->rx_packets++;
2459 stats->rx_bytes += skb->len;
2460 u64_stats_update_end(&stats->syncp);
2461 put_cpu_ptr(stats);
2462
2463 if (rxhash)
2464 tun_flow_update(tun, rxhash, tfile);
2465
2466 out:
2467 return err;
2468 }
2469
2470 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
2471 {
2472 int ret, i;
2473 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2474 struct tun_struct *tun = tun_get(tfile);
2475 struct tun_msg_ctl *ctl = m->msg_control;
2476 struct xdp_buff *xdp;
2477
2478 if (!tun)
2479 return -EBADFD;
2480
2481 if (ctl && (ctl->type == TUN_MSG_PTR)) {
2482 int n = ctl->num;
2483 int flush = 0;
2484
2485 local_bh_disable();
2486 rcu_read_lock();
2487
2488 for (i = 0; i < n; i++) {
2489 xdp = &((struct xdp_buff *)ctl->ptr)[i];
2490 tun_xdp_one(tun, tfile, xdp, &flush);
2491 }
2492
2493 if (flush)
2494 xdp_do_flush_map();
2495
2496 rcu_read_unlock();
2497 local_bh_enable();
2498
2499 ret = total_len;
2500 goto out;
2501 }
2502
2503 ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
2504 m->msg_flags & MSG_DONTWAIT,
2505 m->msg_flags & MSG_MORE);
2506 out:
2507 tun_put(tun);
2508 return ret;
2509 }
2510
2511 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
2512 int flags)
2513 {
2514 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2515 struct tun_struct *tun = tun_get(tfile);
2516 void *ptr = m->msg_control;
2517 int ret;
2518
2519 if (!tun) {
2520 ret = -EBADFD;
2521 goto out_free;
2522 }
2523
2524 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
2525 ret = -EINVAL;
2526 goto out_put_tun;
2527 }
2528 if (flags & MSG_ERRQUEUE) {
2529 ret = sock_recv_errqueue(sock->sk, m, total_len,
2530 SOL_PACKET, TUN_TX_TIMESTAMP);
2531 goto out;
2532 }
2533 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, ptr);
2534 if (ret > (ssize_t)total_len) {
2535 m->msg_flags |= MSG_TRUNC;
2536 ret = flags & MSG_TRUNC ? ret : total_len;
2537 }
2538 out:
2539 tun_put(tun);
2540 return ret;
2541
2542 out_put_tun:
2543 tun_put(tun);
2544 out_free:
2545 tun_ptr_free(ptr);
2546 return ret;
2547 }
2548
2549 static int tun_ptr_peek_len(void *ptr)
2550 {
2551 if (likely(ptr)) {
2552 if (tun_is_xdp_frame(ptr)) {
2553 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2554
2555 return xdpf->len;
2556 }
2557 return __skb_array_len_with_tag(ptr);
2558 } else {
2559 return 0;
2560 }
2561 }
2562
2563 static int tun_peek_len(struct socket *sock)
2564 {
2565 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2566 struct tun_struct *tun;
2567 int ret = 0;
2568
2569 tun = tun_get(tfile);
2570 if (!tun)
2571 return 0;
2572
2573 ret = PTR_RING_PEEK_CALL(&tfile->tx_ring, tun_ptr_peek_len);
2574 tun_put(tun);
2575
2576 return ret;
2577 }
2578
2579 /* Ops structure to mimic raw sockets with tun */
2580 static const struct proto_ops tun_socket_ops = {
2581 .peek_len = tun_peek_len,
2582 .sendmsg = tun_sendmsg,
2583 .recvmsg = tun_recvmsg,
2584 };
2585
2586 static struct proto tun_proto = {
2587 .name = "tun",
2588 .owner = THIS_MODULE,
2589 .obj_size = sizeof(struct tun_file),
2590 };
2591
2592 static int tun_flags(struct tun_struct *tun)
2593 {
2594 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
2595 }
2596
2597 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
2598 char *buf)
2599 {
2600 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2601 return sprintf(buf, "0x%x\n", tun_flags(tun));
2602 }
2603
2604 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
2605 char *buf)
2606 {
2607 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2608 return uid_valid(tun->owner)?
2609 sprintf(buf, "%u\n",
2610 from_kuid_munged(current_user_ns(), tun->owner)):
2611 sprintf(buf, "-1\n");
2612 }
2613
2614 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
2615 char *buf)
2616 {
2617 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2618 return gid_valid(tun->group) ?
2619 sprintf(buf, "%u\n",
2620 from_kgid_munged(current_user_ns(), tun->group)):
2621 sprintf(buf, "-1\n");
2622 }
2623
2624 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
2625 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
2626 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
2627
2628 static struct attribute *tun_dev_attrs[] = {
2629 &dev_attr_tun_flags.attr,
2630 &dev_attr_owner.attr,
2631 &dev_attr_group.attr,
2632 NULL
2633 };
2634
2635 static const struct attribute_group tun_attr_group = {
2636 .attrs = tun_dev_attrs
2637 };
2638
2639 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
2640 {
2641 struct tun_struct *tun;
2642 struct tun_file *tfile = file->private_data;
2643 struct net_device *dev;
2644 int err;
2645
2646 if (tfile->detached)
2647 return -EINVAL;
2648
2649 if ((ifr->ifr_flags & IFF_NAPI_FRAGS)) {
2650 if (!capable(CAP_NET_ADMIN))
2651 return -EPERM;
2652
2653 if (!(ifr->ifr_flags & IFF_NAPI) ||
2654 (ifr->ifr_flags & TUN_TYPE_MASK) != IFF_TAP)
2655 return -EINVAL;
2656 }
2657
2658 dev = __dev_get_by_name(net, ifr->ifr_name);
2659 if (dev) {
2660 if (ifr->ifr_flags & IFF_TUN_EXCL)
2661 return -EBUSY;
2662 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
2663 tun = netdev_priv(dev);
2664 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
2665 tun = netdev_priv(dev);
2666 else
2667 return -EINVAL;
2668
2669 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
2670 !!(tun->flags & IFF_MULTI_QUEUE))
2671 return -EINVAL;
2672
2673 if (tun_not_capable(tun))
2674 return -EPERM;
2675 err = security_tun_dev_open(tun->security);
2676 if (err < 0)
2677 return err;
2678
2679 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
2680 ifr->ifr_flags & IFF_NAPI,
2681 ifr->ifr_flags & IFF_NAPI_FRAGS);
2682 if (err < 0)
2683 return err;
2684
2685 if (tun->flags & IFF_MULTI_QUEUE &&
2686 (tun->numqueues + tun->numdisabled > 1)) {
2687 /* One or more queue has already been attached, no need
2688 * to initialize the device again.
2689 */
2690 netdev_state_change(dev);
2691 return 0;
2692 }
2693
2694 tun->flags = (tun->flags & ~TUN_FEATURES) |
2695 (ifr->ifr_flags & TUN_FEATURES);
2696
2697 netdev_state_change(dev);
2698 } else {
2699 char *name;
2700 unsigned long flags = 0;
2701 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
2702 MAX_TAP_QUEUES : 1;
2703
2704 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2705 return -EPERM;
2706 err = security_tun_dev_create();
2707 if (err < 0)
2708 return err;
2709
2710 /* Set dev type */
2711 if (ifr->ifr_flags & IFF_TUN) {
2712 /* TUN device */
2713 flags |= IFF_TUN;
2714 name = "tun%d";
2715 } else if (ifr->ifr_flags & IFF_TAP) {
2716 /* TAP device */
2717 flags |= IFF_TAP;
2718 name = "tap%d";
2719 } else
2720 return -EINVAL;
2721
2722 if (*ifr->ifr_name)
2723 name = ifr->ifr_name;
2724
2725 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
2726 NET_NAME_UNKNOWN, tun_setup, queues,
2727 queues);
2728
2729 if (!dev)
2730 return -ENOMEM;
2731 err = dev_get_valid_name(net, dev, name);
2732 if (err < 0)
2733 goto err_free_dev;
2734
2735 dev_net_set(dev, net);
2736 dev->rtnl_link_ops = &tun_link_ops;
2737 dev->ifindex = tfile->ifindex;
2738 dev->sysfs_groups[0] = &tun_attr_group;
2739
2740 tun = netdev_priv(dev);
2741 tun->dev = dev;
2742 tun->flags = flags;
2743 tun->txflt.count = 0;
2744 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
2745
2746 tun->align = NET_SKB_PAD;
2747 tun->filter_attached = false;
2748 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
2749 tun->rx_batched = 0;
2750 RCU_INIT_POINTER(tun->steering_prog, NULL);
2751
2752 tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
2753 if (!tun->pcpu_stats) {
2754 err = -ENOMEM;
2755 goto err_free_dev;
2756 }
2757
2758 spin_lock_init(&tun->lock);
2759
2760 err = security_tun_dev_alloc_security(&tun->security);
2761 if (err < 0)
2762 goto err_free_stat;
2763
2764 tun_net_init(dev);
2765 tun_flow_init(tun);
2766
2767 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
2768 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
2769 NETIF_F_HW_VLAN_STAG_TX;
2770 dev->features = dev->hw_features | NETIF_F_LLTX;
2771 dev->vlan_features = dev->features &
2772 ~(NETIF_F_HW_VLAN_CTAG_TX |
2773 NETIF_F_HW_VLAN_STAG_TX);
2774
2775 tun->flags = (tun->flags & ~TUN_FEATURES) |
2776 (ifr->ifr_flags & TUN_FEATURES);
2777
2778 INIT_LIST_HEAD(&tun->disabled);
2779 err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
2780 ifr->ifr_flags & IFF_NAPI_FRAGS);
2781 if (err < 0)
2782 goto err_free_flow;
2783
2784 err = register_netdevice(tun->dev);
2785 if (err < 0)
2786 goto err_detach;
2787 }
2788
2789 netif_carrier_on(tun->dev);
2790
2791 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
2792
2793 /* Make sure persistent devices do not get stuck in
2794 * xoff state.
2795 */
2796 if (netif_running(tun->dev))
2797 netif_tx_wake_all_queues(tun->dev);
2798
2799 strcpy(ifr->ifr_name, tun->dev->name);
2800 return 0;
2801
2802 err_detach:
2803 tun_detach_all(dev);
2804 /* register_netdevice() already called tun_free_netdev() */
2805 goto err_free_dev;
2806
2807 err_free_flow:
2808 tun_flow_uninit(tun);
2809 security_tun_dev_free_security(tun->security);
2810 err_free_stat:
2811 free_percpu(tun->pcpu_stats);
2812 err_free_dev:
2813 free_netdev(dev);
2814 return err;
2815 }
2816
2817 static void tun_get_iff(struct net *net, struct tun_struct *tun,
2818 struct ifreq *ifr)
2819 {
2820 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
2821
2822 strcpy(ifr->ifr_name, tun->dev->name);
2823
2824 ifr->ifr_flags = tun_flags(tun);
2825
2826 }
2827
2828 /* This is like a cut-down ethtool ops, except done via tun fd so no
2829 * privs required. */
2830 static int set_offload(struct tun_struct *tun, unsigned long arg)
2831 {
2832 netdev_features_t features = 0;
2833
2834 if (arg & TUN_F_CSUM) {
2835 features |= NETIF_F_HW_CSUM;
2836 arg &= ~TUN_F_CSUM;
2837
2838 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
2839 if (arg & TUN_F_TSO_ECN) {
2840 features |= NETIF_F_TSO_ECN;
2841 arg &= ~TUN_F_TSO_ECN;
2842 }
2843 if (arg & TUN_F_TSO4)
2844 features |= NETIF_F_TSO;
2845 if (arg & TUN_F_TSO6)
2846 features |= NETIF_F_TSO6;
2847 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
2848 }
2849
2850 arg &= ~TUN_F_UFO;
2851 }
2852
2853 /* This gives the user a way to test for new features in future by
2854 * trying to set them. */
2855 if (arg)
2856 return -EINVAL;
2857
2858 tun->set_features = features;
2859 tun->dev->wanted_features &= ~TUN_USER_FEATURES;
2860 tun->dev->wanted_features |= features;
2861 netdev_update_features(tun->dev);
2862
2863 return 0;
2864 }
2865
2866 static void tun_detach_filter(struct tun_struct *tun, int n)
2867 {
2868 int i;
2869 struct tun_file *tfile;
2870
2871 for (i = 0; i < n; i++) {
2872 tfile = rtnl_dereference(tun->tfiles[i]);
2873 lock_sock(tfile->socket.sk);
2874 sk_detach_filter(tfile->socket.sk);
2875 release_sock(tfile->socket.sk);
2876 }
2877
2878 tun->filter_attached = false;
2879 }
2880
2881 static int tun_attach_filter(struct tun_struct *tun)
2882 {
2883 int i, ret = 0;
2884 struct tun_file *tfile;
2885
2886 for (i = 0; i < tun->numqueues; i++) {
2887 tfile = rtnl_dereference(tun->tfiles[i]);
2888 lock_sock(tfile->socket.sk);
2889 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
2890 release_sock(tfile->socket.sk);
2891 if (ret) {
2892 tun_detach_filter(tun, i);
2893 return ret;
2894 }
2895 }
2896
2897 tun->filter_attached = true;
2898 return ret;
2899 }
2900
2901 static void tun_set_sndbuf(struct tun_struct *tun)
2902 {
2903 struct tun_file *tfile;
2904 int i;
2905
2906 for (i = 0; i < tun->numqueues; i++) {
2907 tfile = rtnl_dereference(tun->tfiles[i]);
2908 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
2909 }
2910 }
2911
2912 static int tun_set_queue(struct file *file, struct ifreq *ifr)
2913 {
2914 struct tun_file *tfile = file->private_data;
2915 struct tun_struct *tun;
2916 int ret = 0;
2917
2918 rtnl_lock();
2919
2920 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
2921 tun = tfile->detached;
2922 if (!tun) {
2923 ret = -EINVAL;
2924 goto unlock;
2925 }
2926 ret = security_tun_dev_attach_queue(tun->security);
2927 if (ret < 0)
2928 goto unlock;
2929 ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI,
2930 tun->flags & IFF_NAPI_FRAGS);
2931 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
2932 tun = rtnl_dereference(tfile->tun);
2933 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
2934 ret = -EINVAL;
2935 else
2936 __tun_detach(tfile, false);
2937 } else
2938 ret = -EINVAL;
2939
2940 if (ret >= 0)
2941 netdev_state_change(tun->dev);
2942
2943 unlock:
2944 rtnl_unlock();
2945 return ret;
2946 }
2947
2948 static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog **prog_p,
2949 void __user *data)
2950 {
2951 struct bpf_prog *prog;
2952 int fd;
2953
2954 if (copy_from_user(&fd, data, sizeof(fd)))
2955 return -EFAULT;
2956
2957 if (fd == -1) {
2958 prog = NULL;
2959 } else {
2960 prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
2961 if (IS_ERR(prog))
2962 return PTR_ERR(prog);
2963 }
2964
2965 return __tun_set_ebpf(tun, prog_p, prog);
2966 }
2967
2968 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
2969 unsigned long arg, int ifreq_len)
2970 {
2971 struct tun_file *tfile = file->private_data;
2972 struct net *net = sock_net(&tfile->sk);
2973 struct tun_struct *tun;
2974 void __user* argp = (void __user*)arg;
2975 struct ifreq ifr;
2976 kuid_t owner;
2977 kgid_t group;
2978 int sndbuf;
2979 int vnet_hdr_sz;
2980 unsigned int ifindex;
2981 int le;
2982 int ret;
2983 bool do_notify = false;
2984
2985 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE ||
2986 (_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) {
2987 if (copy_from_user(&ifr, argp, ifreq_len))
2988 return -EFAULT;
2989 } else {
2990 memset(&ifr, 0, sizeof(ifr));
2991 }
2992 if (cmd == TUNGETFEATURES) {
2993 /* Currently this just means: "what IFF flags are valid?".
2994 * This is needed because we never checked for invalid flags on
2995 * TUNSETIFF.
2996 */
2997 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
2998 (unsigned int __user*)argp);
2999 } else if (cmd == TUNSETQUEUE) {
3000 return tun_set_queue(file, &ifr);
3001 } else if (cmd == SIOCGSKNS) {
3002 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3003 return -EPERM;
3004 return open_related_ns(&net->ns, get_net_ns);
3005 }
3006
3007 ret = 0;
3008 rtnl_lock();
3009
3010 tun = tun_get(tfile);
3011 if (cmd == TUNSETIFF) {
3012 ret = -EEXIST;
3013 if (tun)
3014 goto unlock;
3015
3016 ifr.ifr_name[IFNAMSIZ-1] = '\0';
3017
3018 ret = tun_set_iff(net, file, &ifr);
3019
3020 if (ret)
3021 goto unlock;
3022
3023 if (copy_to_user(argp, &ifr, ifreq_len))
3024 ret = -EFAULT;
3025 goto unlock;
3026 }
3027 if (cmd == TUNSETIFINDEX) {
3028 ret = -EPERM;
3029 if (tun)
3030 goto unlock;
3031
3032 ret = -EFAULT;
3033 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
3034 goto unlock;
3035
3036 ret = 0;
3037 tfile->ifindex = ifindex;
3038 goto unlock;
3039 }
3040
3041 ret = -EBADFD;
3042 if (!tun)
3043 goto unlock;
3044
3045 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
3046
3047 ret = 0;
3048 switch (cmd) {
3049 case TUNGETIFF:
3050 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
3051
3052 if (tfile->detached)
3053 ifr.ifr_flags |= IFF_DETACH_QUEUE;
3054 if (!tfile->socket.sk->sk_filter)
3055 ifr.ifr_flags |= IFF_NOFILTER;
3056
3057 if (copy_to_user(argp, &ifr, ifreq_len))
3058 ret = -EFAULT;
3059 break;
3060
3061 case TUNSETNOCSUM:
3062 /* Disable/Enable checksum */
3063
3064 /* [unimplemented] */
3065 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
3066 arg ? "disabled" : "enabled");
3067 break;
3068
3069 case TUNSETPERSIST:
3070 /* Disable/Enable persist mode. Keep an extra reference to the
3071 * module to prevent the module being unprobed.
3072 */
3073 if (arg && !(tun->flags & IFF_PERSIST)) {
3074 tun->flags |= IFF_PERSIST;
3075 __module_get(THIS_MODULE);
3076 do_notify = true;
3077 }
3078 if (!arg && (tun->flags & IFF_PERSIST)) {
3079 tun->flags &= ~IFF_PERSIST;
3080 module_put(THIS_MODULE);
3081 do_notify = true;
3082 }
3083
3084 tun_debug(KERN_INFO, tun, "persist %s\n",
3085 arg ? "enabled" : "disabled");
3086 break;
3087
3088 case TUNSETOWNER:
3089 /* Set owner of the device */
3090 owner = make_kuid(current_user_ns(), arg);
3091 if (!uid_valid(owner)) {
3092 ret = -EINVAL;
3093 break;
3094 }
3095 tun->owner = owner;
3096 do_notify = true;
3097 tun_debug(KERN_INFO, tun, "owner set to %u\n",
3098 from_kuid(&init_user_ns, tun->owner));
3099 break;
3100
3101 case TUNSETGROUP:
3102 /* Set group of the device */
3103 group = make_kgid(current_user_ns(), arg);
3104 if (!gid_valid(group)) {
3105 ret = -EINVAL;
3106 break;
3107 }
3108 tun->group = group;
3109 do_notify = true;
3110 tun_debug(KERN_INFO, tun, "group set to %u\n",
3111 from_kgid(&init_user_ns, tun->group));
3112 break;
3113
3114 case TUNSETLINK:
3115 /* Only allow setting the type when the interface is down */
3116 if (tun->dev->flags & IFF_UP) {
3117 tun_debug(KERN_INFO, tun,
3118 "Linktype set failed because interface is up\n");
3119 ret = -EBUSY;
3120 } else {
3121 tun->dev->type = (int) arg;
3122 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
3123 tun->dev->type);
3124 ret = 0;
3125 }
3126 break;
3127
3128 #ifdef TUN_DEBUG
3129 case TUNSETDEBUG:
3130 tun->debug = arg;
3131 break;
3132 #endif
3133 case TUNSETOFFLOAD:
3134 ret = set_offload(tun, arg);
3135 break;
3136
3137 case TUNSETTXFILTER:
3138 /* Can be set only for TAPs */
3139 ret = -EINVAL;
3140 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3141 break;
3142 ret = update_filter(&tun->txflt, (void __user *)arg);
3143 break;
3144
3145 case SIOCGIFHWADDR:
3146 /* Get hw address */
3147 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
3148 ifr.ifr_hwaddr.sa_family = tun->dev->type;
3149 if (copy_to_user(argp, &ifr, ifreq_len))
3150 ret = -EFAULT;
3151 break;
3152
3153 case SIOCSIFHWADDR:
3154 /* Set hw address */
3155 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
3156 ifr.ifr_hwaddr.sa_data);
3157
3158 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
3159 break;
3160
3161 case TUNGETSNDBUF:
3162 sndbuf = tfile->socket.sk->sk_sndbuf;
3163 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
3164 ret = -EFAULT;
3165 break;
3166
3167 case TUNSETSNDBUF:
3168 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
3169 ret = -EFAULT;
3170 break;
3171 }
3172 if (sndbuf <= 0) {
3173 ret = -EINVAL;
3174 break;
3175 }
3176
3177 tun->sndbuf = sndbuf;
3178 tun_set_sndbuf(tun);
3179 break;
3180
3181 case TUNGETVNETHDRSZ:
3182 vnet_hdr_sz = tun->vnet_hdr_sz;
3183 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
3184 ret = -EFAULT;
3185 break;
3186
3187 case TUNSETVNETHDRSZ:
3188 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
3189 ret = -EFAULT;
3190 break;
3191 }
3192 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
3193 ret = -EINVAL;
3194 break;
3195 }
3196
3197 tun->vnet_hdr_sz = vnet_hdr_sz;
3198 break;
3199
3200 case TUNGETVNETLE:
3201 le = !!(tun->flags & TUN_VNET_LE);
3202 if (put_user(le, (int __user *)argp))
3203 ret = -EFAULT;
3204 break;
3205
3206 case TUNSETVNETLE:
3207 if (get_user(le, (int __user *)argp)) {
3208 ret = -EFAULT;
3209 break;
3210 }
3211 if (le)
3212 tun->flags |= TUN_VNET_LE;
3213 else
3214 tun->flags &= ~TUN_VNET_LE;
3215 break;
3216
3217 case TUNGETVNETBE:
3218 ret = tun_get_vnet_be(tun, argp);
3219 break;
3220
3221 case TUNSETVNETBE:
3222 ret = tun_set_vnet_be(tun, argp);
3223 break;
3224
3225 case TUNATTACHFILTER:
3226 /* Can be set only for TAPs */
3227 ret = -EINVAL;
3228 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3229 break;
3230 ret = -EFAULT;
3231 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
3232 break;
3233
3234 ret = tun_attach_filter(tun);
3235 break;
3236
3237 case TUNDETACHFILTER:
3238 /* Can be set only for TAPs */
3239 ret = -EINVAL;
3240 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3241 break;
3242 ret = 0;
3243 tun_detach_filter(tun, tun->numqueues);
3244 break;
3245
3246 case TUNGETFILTER:
3247 ret = -EINVAL;
3248 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3249 break;
3250 ret = -EFAULT;
3251 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
3252 break;
3253 ret = 0;
3254 break;
3255
3256 case TUNSETSTEERINGEBPF:
3257 ret = tun_set_ebpf(tun, &tun->steering_prog, argp);
3258 break;
3259
3260 case TUNSETFILTEREBPF:
3261 ret = tun_set_ebpf(tun, &tun->filter_prog, argp);
3262 break;
3263
3264 default:
3265 ret = -EINVAL;
3266 break;
3267 }
3268
3269 if (do_notify)
3270 netdev_state_change(tun->dev);
3271
3272 unlock:
3273 rtnl_unlock();
3274 if (tun)
3275 tun_put(tun);
3276 return ret;
3277 }
3278
3279 static long tun_chr_ioctl(struct file *file,
3280 unsigned int cmd, unsigned long arg)
3281 {
3282 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
3283 }
3284
3285 #ifdef CONFIG_COMPAT
3286 static long tun_chr_compat_ioctl(struct file *file,
3287 unsigned int cmd, unsigned long arg)
3288 {
3289 switch (cmd) {
3290 case TUNSETIFF:
3291 case TUNGETIFF:
3292 case TUNSETTXFILTER:
3293 case TUNGETSNDBUF:
3294 case TUNSETSNDBUF:
3295 case SIOCGIFHWADDR:
3296 case SIOCSIFHWADDR:
3297 arg = (unsigned long)compat_ptr(arg);
3298 break;
3299 default:
3300 arg = (compat_ulong_t)arg;
3301 break;
3302 }
3303
3304 /*
3305 * compat_ifreq is shorter than ifreq, so we must not access beyond
3306 * the end of that structure. All fields that are used in this
3307 * driver are compatible though, we don't need to convert the
3308 * contents.
3309 */
3310 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
3311 }
3312 #endif /* CONFIG_COMPAT */
3313
3314 static int tun_chr_fasync(int fd, struct file *file, int on)
3315 {
3316 struct tun_file *tfile = file->private_data;
3317 int ret;
3318
3319 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
3320 goto out;
3321
3322 if (on) {
3323 __f_setown(file, task_pid(current), PIDTYPE_TGID, 0);
3324 tfile->flags |= TUN_FASYNC;
3325 } else
3326 tfile->flags &= ~TUN_FASYNC;
3327 ret = 0;
3328 out:
3329 return ret;
3330 }
3331
3332 static int tun_chr_open(struct inode *inode, struct file * file)
3333 {
3334 struct net *net = current->nsproxy->net_ns;
3335 struct tun_file *tfile;
3336
3337 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
3338
3339 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
3340 &tun_proto, 0);
3341 if (!tfile)
3342 return -ENOMEM;
3343 if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) {
3344 sk_free(&tfile->sk);
3345 return -ENOMEM;
3346 }
3347
3348 mutex_init(&tfile->napi_mutex);
3349 RCU_INIT_POINTER(tfile->tun, NULL);
3350 tfile->flags = 0;
3351 tfile->ifindex = 0;
3352
3353 init_waitqueue_head(&tfile->wq.wait);
3354 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
3355
3356 tfile->socket.file = file;
3357 tfile->socket.ops = &tun_socket_ops;
3358
3359 sock_init_data(&tfile->socket, &tfile->sk);
3360
3361 tfile->sk.sk_write_space = tun_sock_write_space;
3362 tfile->sk.sk_sndbuf = INT_MAX;
3363
3364 file->private_data = tfile;
3365 INIT_LIST_HEAD(&tfile->next);
3366
3367 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
3368
3369 return 0;
3370 }
3371
3372 static int tun_chr_close(struct inode *inode, struct file *file)
3373 {
3374 struct tun_file *tfile = file->private_data;
3375
3376 tun_detach(tfile, true);
3377
3378 return 0;
3379 }
3380
3381 #ifdef CONFIG_PROC_FS
3382 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file)
3383 {
3384 struct tun_file *tfile = file->private_data;
3385 struct tun_struct *tun;
3386 struct ifreq ifr;
3387
3388 memset(&ifr, 0, sizeof(ifr));
3389
3390 rtnl_lock();
3391 tun = tun_get(tfile);
3392 if (tun)
3393 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
3394 rtnl_unlock();
3395
3396 if (tun)
3397 tun_put(tun);
3398
3399 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
3400 }
3401 #endif
3402
3403 static const struct file_operations tun_fops = {
3404 .owner = THIS_MODULE,
3405 .llseek = no_llseek,
3406 .read_iter = tun_chr_read_iter,
3407 .write_iter = tun_chr_write_iter,
3408 .poll = tun_chr_poll,
3409 .unlocked_ioctl = tun_chr_ioctl,
3410 #ifdef CONFIG_COMPAT
3411 .compat_ioctl = tun_chr_compat_ioctl,
3412 #endif
3413 .open = tun_chr_open,
3414 .release = tun_chr_close,
3415 .fasync = tun_chr_fasync,
3416 #ifdef CONFIG_PROC_FS
3417 .show_fdinfo = tun_chr_show_fdinfo,
3418 #endif
3419 };
3420
3421 static struct miscdevice tun_miscdev = {
3422 .minor = TUN_MINOR,
3423 .name = "tun",
3424 .nodename = "net/tun",
3425 .fops = &tun_fops,
3426 };
3427
3428 /* ethtool interface */
3429
3430 static void tun_default_link_ksettings(struct net_device *dev,
3431 struct ethtool_link_ksettings *cmd)
3432 {
3433 ethtool_link_ksettings_zero_link_mode(cmd, supported);
3434 ethtool_link_ksettings_zero_link_mode(cmd, advertising);
3435 cmd->base.speed = SPEED_10;
3436 cmd->base.duplex = DUPLEX_FULL;
3437 cmd->base.port = PORT_TP;
3438 cmd->base.phy_address = 0;
3439 cmd->base.autoneg = AUTONEG_DISABLE;
3440 }
3441
3442 static int tun_get_link_ksettings(struct net_device *dev,
3443 struct ethtool_link_ksettings *cmd)
3444 {
3445 struct tun_struct *tun = netdev_priv(dev);
3446
3447 memcpy(cmd, &tun->link_ksettings, sizeof(*cmd));
3448 return 0;
3449 }
3450
3451 static int tun_set_link_ksettings(struct net_device *dev,
3452 const struct ethtool_link_ksettings *cmd)
3453 {
3454 struct tun_struct *tun = netdev_priv(dev);
3455
3456 memcpy(&tun->link_ksettings, cmd, sizeof(*cmd));
3457 return 0;
3458 }
3459
3460 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
3461 {
3462 struct tun_struct *tun = netdev_priv(dev);
3463
3464 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
3465 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
3466
3467 switch (tun->flags & TUN_TYPE_MASK) {
3468 case IFF_TUN:
3469 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
3470 break;
3471 case IFF_TAP:
3472 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
3473 break;
3474 }
3475 }
3476
3477 static u32 tun_get_msglevel(struct net_device *dev)
3478 {
3479 #ifdef TUN_DEBUG
3480 struct tun_struct *tun = netdev_priv(dev);
3481 return tun->debug;
3482 #else
3483 return -EOPNOTSUPP;
3484 #endif
3485 }
3486
3487 static void tun_set_msglevel(struct net_device *dev, u32 value)
3488 {
3489 #ifdef TUN_DEBUG
3490 struct tun_struct *tun = netdev_priv(dev);
3491 tun->debug = value;
3492 #endif
3493 }
3494
3495 static int tun_get_coalesce(struct net_device *dev,
3496 struct ethtool_coalesce *ec)
3497 {
3498 struct tun_struct *tun = netdev_priv(dev);
3499
3500 ec->rx_max_coalesced_frames = tun->rx_batched;
3501
3502 return 0;
3503 }
3504
3505 static int tun_set_coalesce(struct net_device *dev,
3506 struct ethtool_coalesce *ec)
3507 {
3508 struct tun_struct *tun = netdev_priv(dev);
3509
3510 if (ec->rx_max_coalesced_frames > NAPI_POLL_WEIGHT)
3511 tun->rx_batched = NAPI_POLL_WEIGHT;
3512 else
3513 tun->rx_batched = ec->rx_max_coalesced_frames;
3514
3515 return 0;
3516 }
3517
3518 static const struct ethtool_ops tun_ethtool_ops = {
3519 .get_drvinfo = tun_get_drvinfo,
3520 .get_msglevel = tun_get_msglevel,
3521 .set_msglevel = tun_set_msglevel,
3522 .get_link = ethtool_op_get_link,
3523 .get_ts_info = ethtool_op_get_ts_info,
3524 .get_coalesce = tun_get_coalesce,
3525 .set_coalesce = tun_set_coalesce,
3526 .get_link_ksettings = tun_get_link_ksettings,
3527 .set_link_ksettings = tun_set_link_ksettings,
3528 };
3529
3530 static int tun_queue_resize(struct tun_struct *tun)
3531 {
3532 struct net_device *dev = tun->dev;
3533 struct tun_file *tfile;
3534 struct ptr_ring **rings;
3535 int n = tun->numqueues + tun->numdisabled;
3536 int ret, i;
3537
3538 rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL);
3539 if (!rings)
3540 return -ENOMEM;
3541
3542 for (i = 0; i < tun->numqueues; i++) {
3543 tfile = rtnl_dereference(tun->tfiles[i]);
3544 rings[i] = &tfile->tx_ring;
3545 }
3546 list_for_each_entry(tfile, &tun->disabled, next)
3547 rings[i++] = &tfile->tx_ring;
3548
3549 ret = ptr_ring_resize_multiple(rings, n,
3550 dev->tx_queue_len, GFP_KERNEL,
3551 tun_ptr_free);
3552
3553 kfree(rings);
3554 return ret;
3555 }
3556
3557 static int tun_device_event(struct notifier_block *unused,
3558 unsigned long event, void *ptr)
3559 {
3560 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3561 struct tun_struct *tun = netdev_priv(dev);
3562
3563 if (dev->rtnl_link_ops != &tun_link_ops)
3564 return NOTIFY_DONE;
3565
3566 switch (event) {
3567 case NETDEV_CHANGE_TX_QUEUE_LEN:
3568 if (tun_queue_resize(tun))
3569 return NOTIFY_BAD;
3570 break;
3571 default:
3572 break;
3573 }
3574
3575 return NOTIFY_DONE;
3576 }
3577
3578 static struct notifier_block tun_notifier_block __read_mostly = {
3579 .notifier_call = tun_device_event,
3580 };
3581
3582 static int __init tun_init(void)
3583 {
3584 int ret = 0;
3585
3586 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
3587
3588 ret = rtnl_link_register(&tun_link_ops);
3589 if (ret) {
3590 pr_err("Can't register link_ops\n");
3591 goto err_linkops;
3592 }
3593
3594 ret = misc_register(&tun_miscdev);
3595 if (ret) {
3596 pr_err("Can't register misc device %d\n", TUN_MINOR);
3597 goto err_misc;
3598 }
3599
3600 ret = register_netdevice_notifier(&tun_notifier_block);
3601 if (ret) {
3602 pr_err("Can't register netdevice notifier\n");
3603 goto err_notifier;
3604 }
3605
3606 return 0;
3607
3608 err_notifier:
3609 misc_deregister(&tun_miscdev);
3610 err_misc:
3611 rtnl_link_unregister(&tun_link_ops);
3612 err_linkops:
3613 return ret;
3614 }
3615
3616 static void tun_cleanup(void)
3617 {
3618 misc_deregister(&tun_miscdev);
3619 rtnl_link_unregister(&tun_link_ops);
3620 unregister_netdevice_notifier(&tun_notifier_block);
3621 }
3622
3623 /* Get an underlying socket object from tun file. Returns error unless file is
3624 * attached to a device. The returned object works like a packet socket, it
3625 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
3626 * holding a reference to the file for as long as the socket is in use. */
3627 struct socket *tun_get_socket(struct file *file)
3628 {
3629 struct tun_file *tfile;
3630 if (file->f_op != &tun_fops)
3631 return ERR_PTR(-EINVAL);
3632 tfile = file->private_data;
3633 if (!tfile)
3634 return ERR_PTR(-EBADFD);
3635 return &tfile->socket;
3636 }
3637 EXPORT_SYMBOL_GPL(tun_get_socket);
3638
3639 struct ptr_ring *tun_get_tx_ring(struct file *file)
3640 {
3641 struct tun_file *tfile;
3642
3643 if (file->f_op != &tun_fops)
3644 return ERR_PTR(-EINVAL);
3645 tfile = file->private_data;
3646 if (!tfile)
3647 return ERR_PTR(-EBADFD);
3648 return &tfile->tx_ring;
3649 }
3650 EXPORT_SYMBOL_GPL(tun_get_tx_ring);
3651
3652 module_init(tun_init);
3653 module_exit(tun_cleanup);
3654 MODULE_DESCRIPTION(DRV_DESCRIPTION);
3655 MODULE_AUTHOR(DRV_COPYRIGHT);
3656 MODULE_LICENSE("GPL");
3657 MODULE_ALIAS_MISCDEV(TUN_MINOR);
3658 MODULE_ALIAS("devname:net/tun");
Linux with added FPC-III support