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drm/tests: hdmi: Fix memory leaks in drm_display_mode_from_cea_vic()
[drm/drm-misc.git] / net / core / sock_map.c
blob07d6aa4e39ef606aab33bd0d95711ecf156596b9
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
3
4 #include <linux/bpf.h>
5 #include <linux/btf_ids.h>
6 #include <linux/filter.h>
7 #include <linux/errno.h>
8 #include <linux/file.h>
9 #include <linux/net.h>
10 #include <linux/workqueue.h>
11 #include <linux/skmsg.h>
12 #include <linux/list.h>
13 #include <linux/jhash.h>
14 #include <linux/sock_diag.h>
15 #include <net/udp.h>
16
17 struct bpf_stab {
18 struct bpf_map map;
19 struct sock **sks;
20 struct sk_psock_progs progs;
21 spinlock_t lock;
22 };
23
24 #define SOCK_CREATE_FLAG_MASK \
25 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
26
27 /* This mutex is used to
28 * - protect race between prog/link attach/detach and link prog update, and
29 * - protect race between releasing and accessing map in bpf_link.
30 * A single global mutex lock is used since it is expected contention is low.
31 */
32 static DEFINE_MUTEX(sockmap_mutex);
33
34 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
35 struct bpf_prog *old, struct bpf_link *link,
36 u32 which);
37 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map);
38
39 static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
40 {
41 struct bpf_stab *stab;
42
43 if (attr->max_entries == 0 ||
44 attr->key_size != 4 ||
45 (attr->value_size != sizeof(u32) &&
46 attr->value_size != sizeof(u64)) ||
47 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
48 return ERR_PTR(-EINVAL);
49
50 stab = bpf_map_area_alloc(sizeof(*stab), NUMA_NO_NODE);
51 if (!stab)
52 return ERR_PTR(-ENOMEM);
53
54 bpf_map_init_from_attr(&stab->map, attr);
55 spin_lock_init(&stab->lock);
56
57 stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries *
58 sizeof(struct sock *),
59 stab->map.numa_node);
60 if (!stab->sks) {
61 bpf_map_area_free(stab);
62 return ERR_PTR(-ENOMEM);
63 }
64
65 return &stab->map;
66 }
67
68 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
69 {
70 struct bpf_map *map;
71 int ret;
72
73 if (attr->attach_flags || attr->replace_bpf_fd)
74 return -EINVAL;
75
76 CLASS(fd, f)(attr->target_fd);
77 map = __bpf_map_get(f);
78 if (IS_ERR(map))
79 return PTR_ERR(map);
80 mutex_lock(&sockmap_mutex);
81 ret = sock_map_prog_update(map, prog, NULL, NULL, attr->attach_type);
82 mutex_unlock(&sockmap_mutex);
83 return ret;
84 }
85
86 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
87 {
88 struct bpf_prog *prog;
89 struct bpf_map *map;
90 int ret;
91
92 if (attr->attach_flags || attr->replace_bpf_fd)
93 return -EINVAL;
94
95 CLASS(fd, f)(attr->target_fd);
96 map = __bpf_map_get(f);
97 if (IS_ERR(map))
98 return PTR_ERR(map);
99
100 prog = bpf_prog_get(attr->attach_bpf_fd);
101 if (IS_ERR(prog))
102 return PTR_ERR(prog);
103
104 if (prog->type != ptype) {
105 ret = -EINVAL;
106 goto put_prog;
107 }
108
109 mutex_lock(&sockmap_mutex);
110 ret = sock_map_prog_update(map, NULL, prog, NULL, attr->attach_type);
111 mutex_unlock(&sockmap_mutex);
112 put_prog:
113 bpf_prog_put(prog);
114 return ret;
115 }
116
117 static void sock_map_sk_acquire(struct sock *sk)
118 __acquires(&sk->sk_lock.slock)
119 {
120 lock_sock(sk);
121 rcu_read_lock();
122 }
123
124 static void sock_map_sk_release(struct sock *sk)
125 __releases(&sk->sk_lock.slock)
126 {
127 rcu_read_unlock();
128 release_sock(sk);
129 }
130
131 static void sock_map_add_link(struct sk_psock *psock,
132 struct sk_psock_link *link,
133 struct bpf_map *map, void *link_raw)
134 {
135 link->link_raw = link_raw;
136 link->map = map;
137 spin_lock_bh(&psock->link_lock);
138 list_add_tail(&link->list, &psock->link);
139 spin_unlock_bh(&psock->link_lock);
140 }
141
142 static void sock_map_del_link(struct sock *sk,
143 struct sk_psock *psock, void *link_raw)
144 {
145 bool strp_stop = false, verdict_stop = false;
146 struct sk_psock_link *link, *tmp;
147
148 spin_lock_bh(&psock->link_lock);
149 list_for_each_entry_safe(link, tmp, &psock->link, list) {
150 if (link->link_raw == link_raw) {
151 struct bpf_map *map = link->map;
152 struct sk_psock_progs *progs = sock_map_progs(map);
153
154 if (psock->saved_data_ready && progs->stream_parser)
155 strp_stop = true;
156 if (psock->saved_data_ready && progs->stream_verdict)
157 verdict_stop = true;
158 if (psock->saved_data_ready && progs->skb_verdict)
159 verdict_stop = true;
160 list_del(&link->list);
161 sk_psock_free_link(link);
162 }
163 }
164 spin_unlock_bh(&psock->link_lock);
165 if (strp_stop || verdict_stop) {
166 write_lock_bh(&sk->sk_callback_lock);
167 if (strp_stop)
168 sk_psock_stop_strp(sk, psock);
169 if (verdict_stop)
170 sk_psock_stop_verdict(sk, psock);
171
172 if (psock->psock_update_sk_prot)
173 psock->psock_update_sk_prot(sk, psock, false);
174 write_unlock_bh(&sk->sk_callback_lock);
175 }
176 }
177
178 static void sock_map_unref(struct sock *sk, void *link_raw)
179 {
180 struct sk_psock *psock = sk_psock(sk);
181
182 if (likely(psock)) {
183 sock_map_del_link(sk, psock, link_raw);
184 sk_psock_put(sk, psock);
185 }
186 }
187
188 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
189 {
190 if (!sk->sk_prot->psock_update_sk_prot)
191 return -EINVAL;
192 psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot;
193 return sk->sk_prot->psock_update_sk_prot(sk, psock, false);
194 }
195
196 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
197 {
198 struct sk_psock *psock;
199
200 rcu_read_lock();
201 psock = sk_psock(sk);
202 if (psock) {
203 if (sk->sk_prot->close != sock_map_close) {
204 psock = ERR_PTR(-EBUSY);
205 goto out;
206 }
207
208 if (!refcount_inc_not_zero(&psock->refcnt))
209 psock = ERR_PTR(-EBUSY);
210 }
211 out:
212 rcu_read_unlock();
213 return psock;
214 }
215
216 static int sock_map_link(struct bpf_map *map, struct sock *sk)
217 {
218 struct sk_psock_progs *progs = sock_map_progs(map);
219 struct bpf_prog *stream_verdict = NULL;
220 struct bpf_prog *stream_parser = NULL;
221 struct bpf_prog *skb_verdict = NULL;
222 struct bpf_prog *msg_parser = NULL;
223 struct sk_psock *psock;
224 int ret;
225
226 stream_verdict = READ_ONCE(progs->stream_verdict);
227 if (stream_verdict) {
228 stream_verdict = bpf_prog_inc_not_zero(stream_verdict);
229 if (IS_ERR(stream_verdict))
230 return PTR_ERR(stream_verdict);
231 }
232
233 stream_parser = READ_ONCE(progs->stream_parser);
234 if (stream_parser) {
235 stream_parser = bpf_prog_inc_not_zero(stream_parser);
236 if (IS_ERR(stream_parser)) {
237 ret = PTR_ERR(stream_parser);
238 goto out_put_stream_verdict;
239 }
240 }
241
242 msg_parser = READ_ONCE(progs->msg_parser);
243 if (msg_parser) {
244 msg_parser = bpf_prog_inc_not_zero(msg_parser);
245 if (IS_ERR(msg_parser)) {
246 ret = PTR_ERR(msg_parser);
247 goto out_put_stream_parser;
248 }
249 }
250
251 skb_verdict = READ_ONCE(progs->skb_verdict);
252 if (skb_verdict) {
253 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
254 if (IS_ERR(skb_verdict)) {
255 ret = PTR_ERR(skb_verdict);
256 goto out_put_msg_parser;
257 }
258 }
259
260 psock = sock_map_psock_get_checked(sk);
261 if (IS_ERR(psock)) {
262 ret = PTR_ERR(psock);
263 goto out_progs;
264 }
265
266 if (psock) {
267 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
268 (stream_parser && READ_ONCE(psock->progs.stream_parser)) ||
269 (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
270 (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) ||
271 (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
272 (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) {
273 sk_psock_put(sk, psock);
274 ret = -EBUSY;
275 goto out_progs;
276 }
277 } else {
278 psock = sk_psock_init(sk, map->numa_node);
279 if (IS_ERR(psock)) {
280 ret = PTR_ERR(psock);
281 goto out_progs;
282 }
283 }
284
285 if (msg_parser)
286 psock_set_prog(&psock->progs.msg_parser, msg_parser);
287 if (stream_parser)
288 psock_set_prog(&psock->progs.stream_parser, stream_parser);
289 if (stream_verdict)
290 psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
291 if (skb_verdict)
292 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
293
294 /* msg_* and stream_* programs references tracked in psock after this
295 * point. Reference dec and cleanup will occur through psock destructor
296 */
297 ret = sock_map_init_proto(sk, psock);
298 if (ret < 0) {
299 sk_psock_put(sk, psock);
300 goto out;
301 }
302
303 write_lock_bh(&sk->sk_callback_lock);
304 if (stream_parser && stream_verdict && !psock->saved_data_ready) {
305 ret = sk_psock_init_strp(sk, psock);
306 if (ret) {
307 write_unlock_bh(&sk->sk_callback_lock);
308 sk_psock_put(sk, psock);
309 goto out;
310 }
311 sk_psock_start_strp(sk, psock);
312 } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) {
313 sk_psock_start_verdict(sk,psock);
314 } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) {
315 sk_psock_start_verdict(sk, psock);
316 }
317 write_unlock_bh(&sk->sk_callback_lock);
318 return 0;
319 out_progs:
320 if (skb_verdict)
321 bpf_prog_put(skb_verdict);
322 out_put_msg_parser:
323 if (msg_parser)
324 bpf_prog_put(msg_parser);
325 out_put_stream_parser:
326 if (stream_parser)
327 bpf_prog_put(stream_parser);
328 out_put_stream_verdict:
329 if (stream_verdict)
330 bpf_prog_put(stream_verdict);
331 out:
332 return ret;
333 }
334
335 static void sock_map_free(struct bpf_map *map)
336 {
337 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
338 int i;
339
340 /* After the sync no updates or deletes will be in-flight so it
341 * is safe to walk map and remove entries without risking a race
342 * in EEXIST update case.
343 */
344 synchronize_rcu();
345 for (i = 0; i < stab->map.max_entries; i++) {
346 struct sock **psk = &stab->sks[i];
347 struct sock *sk;
348
349 sk = xchg(psk, NULL);
350 if (sk) {
351 sock_hold(sk);
352 lock_sock(sk);
353 rcu_read_lock();
354 sock_map_unref(sk, psk);
355 rcu_read_unlock();
356 release_sock(sk);
357 sock_put(sk);
358 }
359 }
360
361 /* wait for psock readers accessing its map link */
362 synchronize_rcu();
363
364 bpf_map_area_free(stab->sks);
365 bpf_map_area_free(stab);
366 }
367
368 static void sock_map_release_progs(struct bpf_map *map)
369 {
370 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
371 }
372
373 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
374 {
375 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
376
377 WARN_ON_ONCE(!rcu_read_lock_held());
378
379 if (unlikely(key >= map->max_entries))
380 return NULL;
381 return READ_ONCE(stab->sks[key]);
382 }
383
384 static void *sock_map_lookup(struct bpf_map *map, void *key)
385 {
386 struct sock *sk;
387
388 sk = __sock_map_lookup_elem(map, *(u32 *)key);
389 if (!sk)
390 return NULL;
391 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
392 return NULL;
393 return sk;
394 }
395
396 static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
397 {
398 struct sock *sk;
399
400 if (map->value_size != sizeof(u64))
401 return ERR_PTR(-ENOSPC);
402
403 sk = __sock_map_lookup_elem(map, *(u32 *)key);
404 if (!sk)
405 return ERR_PTR(-ENOENT);
406
407 __sock_gen_cookie(sk);
408 return &sk->sk_cookie;
409 }
410
411 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
412 struct sock **psk)
413 {
414 struct sock *sk;
415 int err = 0;
416
417 spin_lock_bh(&stab->lock);
418 sk = *psk;
419 if (!sk_test || sk_test == sk)
420 sk = xchg(psk, NULL);
421
422 if (likely(sk))
423 sock_map_unref(sk, psk);
424 else
425 err = -EINVAL;
426
427 spin_unlock_bh(&stab->lock);
428 return err;
429 }
430
431 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
432 void *link_raw)
433 {
434 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
435
436 __sock_map_delete(stab, sk, link_raw);
437 }
438
439 static long sock_map_delete_elem(struct bpf_map *map, void *key)
440 {
441 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
442 u32 i = *(u32 *)key;
443 struct sock **psk;
444
445 if (unlikely(i >= map->max_entries))
446 return -EINVAL;
447
448 psk = &stab->sks[i];
449 return __sock_map_delete(stab, NULL, psk);
450 }
451
452 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
453 {
454 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
455 u32 i = key ? *(u32 *)key : U32_MAX;
456 u32 *key_next = next;
457
458 if (i == stab->map.max_entries - 1)
459 return -ENOENT;
460 if (i >= stab->map.max_entries)
461 *key_next = 0;
462 else
463 *key_next = i + 1;
464 return 0;
465 }
466
467 static int sock_map_update_common(struct bpf_map *map, u32 idx,
468 struct sock *sk, u64 flags)
469 {
470 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
471 struct sk_psock_link *link;
472 struct sk_psock *psock;
473 struct sock *osk;
474 int ret;
475
476 WARN_ON_ONCE(!rcu_read_lock_held());
477 if (unlikely(flags > BPF_EXIST))
478 return -EINVAL;
479 if (unlikely(idx >= map->max_entries))
480 return -E2BIG;
481
482 link = sk_psock_init_link();
483 if (!link)
484 return -ENOMEM;
485
486 ret = sock_map_link(map, sk);
487 if (ret < 0)
488 goto out_free;
489
490 psock = sk_psock(sk);
491 WARN_ON_ONCE(!psock);
492
493 spin_lock_bh(&stab->lock);
494 osk = stab->sks[idx];
495 if (osk && flags == BPF_NOEXIST) {
496 ret = -EEXIST;
497 goto out_unlock;
498 } else if (!osk && flags == BPF_EXIST) {
499 ret = -ENOENT;
500 goto out_unlock;
501 }
502
503 sock_map_add_link(psock, link, map, &stab->sks[idx]);
504 stab->sks[idx] = sk;
505 if (osk)
506 sock_map_unref(osk, &stab->sks[idx]);
507 spin_unlock_bh(&stab->lock);
508 return 0;
509 out_unlock:
510 spin_unlock_bh(&stab->lock);
511 if (psock)
512 sk_psock_put(sk, psock);
513 out_free:
514 sk_psock_free_link(link);
515 return ret;
516 }
517
518 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
519 {
520 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
521 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
522 ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
523 }
524
525 static bool sock_map_redirect_allowed(const struct sock *sk)
526 {
527 if (sk_is_tcp(sk))
528 return sk->sk_state != TCP_LISTEN;
529 else
530 return sk->sk_state == TCP_ESTABLISHED;
531 }
532
533 static bool sock_map_sk_is_suitable(const struct sock *sk)
534 {
535 return !!sk->sk_prot->psock_update_sk_prot;
536 }
537
538 static bool sock_map_sk_state_allowed(const struct sock *sk)
539 {
540 if (sk_is_tcp(sk))
541 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
542 if (sk_is_stream_unix(sk))
543 return (1 << sk->sk_state) & TCPF_ESTABLISHED;
544 return true;
545 }
546
547 static int sock_hash_update_common(struct bpf_map *map, void *key,
548 struct sock *sk, u64 flags);
549
550 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
551 u64 flags)
552 {
553 struct socket *sock;
554 struct sock *sk;
555 int ret;
556 u64 ufd;
557
558 if (map->value_size == sizeof(u64))
559 ufd = *(u64 *)value;
560 else
561 ufd = *(u32 *)value;
562 if (ufd > S32_MAX)
563 return -EINVAL;
564
565 sock = sockfd_lookup(ufd, &ret);
566 if (!sock)
567 return ret;
568 sk = sock->sk;
569 if (!sk) {
570 ret = -EINVAL;
571 goto out;
572 }
573 if (!sock_map_sk_is_suitable(sk)) {
574 ret = -EOPNOTSUPP;
575 goto out;
576 }
577
578 sock_map_sk_acquire(sk);
579 if (!sock_map_sk_state_allowed(sk))
580 ret = -EOPNOTSUPP;
581 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
582 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
583 else
584 ret = sock_hash_update_common(map, key, sk, flags);
585 sock_map_sk_release(sk);
586 out:
587 sockfd_put(sock);
588 return ret;
589 }
590
591 static long sock_map_update_elem(struct bpf_map *map, void *key,
592 void *value, u64 flags)
593 {
594 struct sock *sk = (struct sock *)value;
595 int ret;
596
597 if (unlikely(!sk || !sk_fullsock(sk)))
598 return -EINVAL;
599
600 if (!sock_map_sk_is_suitable(sk))
601 return -EOPNOTSUPP;
602
603 local_bh_disable();
604 bh_lock_sock(sk);
605 if (!sock_map_sk_state_allowed(sk))
606 ret = -EOPNOTSUPP;
607 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
608 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
609 else
610 ret = sock_hash_update_common(map, key, sk, flags);
611 bh_unlock_sock(sk);
612 local_bh_enable();
613 return ret;
614 }
615
616 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
617 struct bpf_map *, map, void *, key, u64, flags)
618 {
619 WARN_ON_ONCE(!rcu_read_lock_held());
620
621 if (likely(sock_map_sk_is_suitable(sops->sk) &&
622 sock_map_op_okay(sops)))
623 return sock_map_update_common(map, *(u32 *)key, sops->sk,
624 flags);
625 return -EOPNOTSUPP;
626 }
627
628 const struct bpf_func_proto bpf_sock_map_update_proto = {
629 .func = bpf_sock_map_update,
630 .gpl_only = false,
631 .pkt_access = true,
632 .ret_type = RET_INTEGER,
633 .arg1_type = ARG_PTR_TO_CTX,
634 .arg2_type = ARG_CONST_MAP_PTR,
635 .arg3_type = ARG_PTR_TO_MAP_KEY,
636 .arg4_type = ARG_ANYTHING,
637 };
638
639 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
640 struct bpf_map *, map, u32, key, u64, flags)
641 {
642 struct sock *sk;
643
644 if (unlikely(flags & ~(BPF_F_INGRESS)))
645 return SK_DROP;
646
647 sk = __sock_map_lookup_elem(map, key);
648 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
649 return SK_DROP;
650 if ((flags & BPF_F_INGRESS) && sk_is_vsock(sk))
651 return SK_DROP;
652
653 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
654 return SK_PASS;
655 }
656
657 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
658 .func = bpf_sk_redirect_map,
659 .gpl_only = false,
660 .ret_type = RET_INTEGER,
661 .arg1_type = ARG_PTR_TO_CTX,
662 .arg2_type = ARG_CONST_MAP_PTR,
663 .arg3_type = ARG_ANYTHING,
664 .arg4_type = ARG_ANYTHING,
665 };
666
667 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
668 struct bpf_map *, map, u32, key, u64, flags)
669 {
670 struct sock *sk;
671
672 if (unlikely(flags & ~(BPF_F_INGRESS)))
673 return SK_DROP;
674
675 sk = __sock_map_lookup_elem(map, key);
676 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
677 return SK_DROP;
678 if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
679 return SK_DROP;
680 if (sk_is_vsock(sk))
681 return SK_DROP;
682
683 msg->flags = flags;
684 msg->sk_redir = sk;
685 return SK_PASS;
686 }
687
688 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
689 .func = bpf_msg_redirect_map,
690 .gpl_only = false,
691 .ret_type = RET_INTEGER,
692 .arg1_type = ARG_PTR_TO_CTX,
693 .arg2_type = ARG_CONST_MAP_PTR,
694 .arg3_type = ARG_ANYTHING,
695 .arg4_type = ARG_ANYTHING,
696 };
697
698 struct sock_map_seq_info {
699 struct bpf_map *map;
700 struct sock *sk;
701 u32 index;
702 };
703
704 struct bpf_iter__sockmap {
705 __bpf_md_ptr(struct bpf_iter_meta *, meta);
706 __bpf_md_ptr(struct bpf_map *, map);
707 __bpf_md_ptr(void *, key);
708 __bpf_md_ptr(struct sock *, sk);
709 };
710
711 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
712 struct bpf_map *map, void *key,
713 struct sock *sk)
714
715 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
716 {
717 if (unlikely(info->index >= info->map->max_entries))
718 return NULL;
719
720 info->sk = __sock_map_lookup_elem(info->map, info->index);
721
722 /* can't return sk directly, since that might be NULL */
723 return info;
724 }
725
726 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
727 __acquires(rcu)
728 {
729 struct sock_map_seq_info *info = seq->private;
730
731 if (*pos == 0)
732 ++*pos;
733
734 /* pairs with sock_map_seq_stop */
735 rcu_read_lock();
736 return sock_map_seq_lookup_elem(info);
737 }
738
739 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
740 __must_hold(rcu)
741 {
742 struct sock_map_seq_info *info = seq->private;
743
744 ++*pos;
745 ++info->index;
746
747 return sock_map_seq_lookup_elem(info);
748 }
749
750 static int sock_map_seq_show(struct seq_file *seq, void *v)
751 __must_hold(rcu)
752 {
753 struct sock_map_seq_info *info = seq->private;
754 struct bpf_iter__sockmap ctx = {};
755 struct bpf_iter_meta meta;
756 struct bpf_prog *prog;
757
758 meta.seq = seq;
759 prog = bpf_iter_get_info(&meta, !v);
760 if (!prog)
761 return 0;
762
763 ctx.meta = &meta;
764 ctx.map = info->map;
765 if (v) {
766 ctx.key = &info->index;
767 ctx.sk = info->sk;
768 }
769
770 return bpf_iter_run_prog(prog, &ctx);
771 }
772
773 static void sock_map_seq_stop(struct seq_file *seq, void *v)
774 __releases(rcu)
775 {
776 if (!v)
777 (void)sock_map_seq_show(seq, NULL);
778
779 /* pairs with sock_map_seq_start */
780 rcu_read_unlock();
781 }
782
783 static const struct seq_operations sock_map_seq_ops = {
784 .start = sock_map_seq_start,
785 .next = sock_map_seq_next,
786 .stop = sock_map_seq_stop,
787 .show = sock_map_seq_show,
788 };
789
790 static int sock_map_init_seq_private(void *priv_data,
791 struct bpf_iter_aux_info *aux)
792 {
793 struct sock_map_seq_info *info = priv_data;
794
795 bpf_map_inc_with_uref(aux->map);
796 info->map = aux->map;
797 return 0;
798 }
799
800 static void sock_map_fini_seq_private(void *priv_data)
801 {
802 struct sock_map_seq_info *info = priv_data;
803
804 bpf_map_put_with_uref(info->map);
805 }
806
807 static u64 sock_map_mem_usage(const struct bpf_map *map)
808 {
809 u64 usage = sizeof(struct bpf_stab);
810
811 usage += (u64)map->max_entries * sizeof(struct sock *);
812 return usage;
813 }
814
815 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
816 .seq_ops = &sock_map_seq_ops,
817 .init_seq_private = sock_map_init_seq_private,
818 .fini_seq_private = sock_map_fini_seq_private,
819 .seq_priv_size = sizeof(struct sock_map_seq_info),
820 };
821
822 BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab)
823 const struct bpf_map_ops sock_map_ops = {
824 .map_meta_equal = bpf_map_meta_equal,
825 .map_alloc = sock_map_alloc,
826 .map_free = sock_map_free,
827 .map_get_next_key = sock_map_get_next_key,
828 .map_lookup_elem_sys_only = sock_map_lookup_sys,
829 .map_update_elem = sock_map_update_elem,
830 .map_delete_elem = sock_map_delete_elem,
831 .map_lookup_elem = sock_map_lookup,
832 .map_release_uref = sock_map_release_progs,
833 .map_check_btf = map_check_no_btf,
834 .map_mem_usage = sock_map_mem_usage,
835 .map_btf_id = &sock_map_btf_ids[0],
836 .iter_seq_info = &sock_map_iter_seq_info,
837 };
838
839 struct bpf_shtab_elem {
840 struct rcu_head rcu;
841 u32 hash;
842 struct sock *sk;
843 struct hlist_node node;
844 u8 key[];
845 };
846
847 struct bpf_shtab_bucket {
848 struct hlist_head head;
849 spinlock_t lock;
850 };
851
852 struct bpf_shtab {
853 struct bpf_map map;
854 struct bpf_shtab_bucket *buckets;
855 u32 buckets_num;
856 u32 elem_size;
857 struct sk_psock_progs progs;
858 atomic_t count;
859 };
860
861 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
862 {
863 return jhash(key, len, 0);
864 }
865
866 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
867 u32 hash)
868 {
869 return &htab->buckets[hash & (htab->buckets_num - 1)];
870 }
871
872 static struct bpf_shtab_elem *
873 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
874 u32 key_size)
875 {
876 struct bpf_shtab_elem *elem;
877
878 hlist_for_each_entry_rcu(elem, head, node) {
879 if (elem->hash == hash &&
880 !memcmp(&elem->key, key, key_size))
881 return elem;
882 }
883
884 return NULL;
885 }
886
887 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
888 {
889 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
890 u32 key_size = map->key_size, hash;
891 struct bpf_shtab_bucket *bucket;
892 struct bpf_shtab_elem *elem;
893
894 WARN_ON_ONCE(!rcu_read_lock_held());
895
896 hash = sock_hash_bucket_hash(key, key_size);
897 bucket = sock_hash_select_bucket(htab, hash);
898 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
899
900 return elem ? elem->sk : NULL;
901 }
902
903 static void sock_hash_free_elem(struct bpf_shtab *htab,
904 struct bpf_shtab_elem *elem)
905 {
906 atomic_dec(&htab->count);
907 kfree_rcu(elem, rcu);
908 }
909
910 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
911 void *link_raw)
912 {
913 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
914 struct bpf_shtab_elem *elem_probe, *elem = link_raw;
915 struct bpf_shtab_bucket *bucket;
916
917 WARN_ON_ONCE(!rcu_read_lock_held());
918 bucket = sock_hash_select_bucket(htab, elem->hash);
919
920 /* elem may be deleted in parallel from the map, but access here
921 * is okay since it's going away only after RCU grace period.
922 * However, we need to check whether it's still present.
923 */
924 spin_lock_bh(&bucket->lock);
925 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
926 elem->key, map->key_size);
927 if (elem_probe && elem_probe == elem) {
928 hlist_del_rcu(&elem->node);
929 sock_map_unref(elem->sk, elem);
930 sock_hash_free_elem(htab, elem);
931 }
932 spin_unlock_bh(&bucket->lock);
933 }
934
935 static long sock_hash_delete_elem(struct bpf_map *map, void *key)
936 {
937 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
938 u32 hash, key_size = map->key_size;
939 struct bpf_shtab_bucket *bucket;
940 struct bpf_shtab_elem *elem;
941 int ret = -ENOENT;
942
943 hash = sock_hash_bucket_hash(key, key_size);
944 bucket = sock_hash_select_bucket(htab, hash);
945
946 spin_lock_bh(&bucket->lock);
947 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
948 if (elem) {
949 hlist_del_rcu(&elem->node);
950 sock_map_unref(elem->sk, elem);
951 sock_hash_free_elem(htab, elem);
952 ret = 0;
953 }
954 spin_unlock_bh(&bucket->lock);
955 return ret;
956 }
957
958 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
959 void *key, u32 key_size,
960 u32 hash, struct sock *sk,
961 struct bpf_shtab_elem *old)
962 {
963 struct bpf_shtab_elem *new;
964
965 if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
966 if (!old) {
967 atomic_dec(&htab->count);
968 return ERR_PTR(-E2BIG);
969 }
970 }
971
972 new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
973 GFP_ATOMIC | __GFP_NOWARN,
974 htab->map.numa_node);
975 if (!new) {
976 atomic_dec(&htab->count);
977 return ERR_PTR(-ENOMEM);
978 }
979 memcpy(new->key, key, key_size);
980 new->sk = sk;
981 new->hash = hash;
982 return new;
983 }
984
985 static int sock_hash_update_common(struct bpf_map *map, void *key,
986 struct sock *sk, u64 flags)
987 {
988 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
989 u32 key_size = map->key_size, hash;
990 struct bpf_shtab_elem *elem, *elem_new;
991 struct bpf_shtab_bucket *bucket;
992 struct sk_psock_link *link;
993 struct sk_psock *psock;
994 int ret;
995
996 WARN_ON_ONCE(!rcu_read_lock_held());
997 if (unlikely(flags > BPF_EXIST))
998 return -EINVAL;
999
1000 link = sk_psock_init_link();
1001 if (!link)
1002 return -ENOMEM;
1003
1004 ret = sock_map_link(map, sk);
1005 if (ret < 0)
1006 goto out_free;
1007
1008 psock = sk_psock(sk);
1009 WARN_ON_ONCE(!psock);
1010
1011 hash = sock_hash_bucket_hash(key, key_size);
1012 bucket = sock_hash_select_bucket(htab, hash);
1013
1014 spin_lock_bh(&bucket->lock);
1015 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1016 if (elem && flags == BPF_NOEXIST) {
1017 ret = -EEXIST;
1018 goto out_unlock;
1019 } else if (!elem && flags == BPF_EXIST) {
1020 ret = -ENOENT;
1021 goto out_unlock;
1022 }
1023
1024 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1025 if (IS_ERR(elem_new)) {
1026 ret = PTR_ERR(elem_new);
1027 goto out_unlock;
1028 }
1029
1030 sock_map_add_link(psock, link, map, elem_new);
1031 /* Add new element to the head of the list, so that
1032 * concurrent search will find it before old elem.
1033 */
1034 hlist_add_head_rcu(&elem_new->node, &bucket->head);
1035 if (elem) {
1036 hlist_del_rcu(&elem->node);
1037 sock_map_unref(elem->sk, elem);
1038 sock_hash_free_elem(htab, elem);
1039 }
1040 spin_unlock_bh(&bucket->lock);
1041 return 0;
1042 out_unlock:
1043 spin_unlock_bh(&bucket->lock);
1044 sk_psock_put(sk, psock);
1045 out_free:
1046 sk_psock_free_link(link);
1047 return ret;
1048 }
1049
1050 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1051 void *key_next)
1052 {
1053 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1054 struct bpf_shtab_elem *elem, *elem_next;
1055 u32 hash, key_size = map->key_size;
1056 struct hlist_head *head;
1057 int i = 0;
1058
1059 if (!key)
1060 goto find_first_elem;
1061 hash = sock_hash_bucket_hash(key, key_size);
1062 head = &sock_hash_select_bucket(htab, hash)->head;
1063 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1064 if (!elem)
1065 goto find_first_elem;
1066
1067 elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1068 struct bpf_shtab_elem, node);
1069 if (elem_next) {
1070 memcpy(key_next, elem_next->key, key_size);
1071 return 0;
1072 }
1073
1074 i = hash & (htab->buckets_num - 1);
1075 i++;
1076 find_first_elem:
1077 for (; i < htab->buckets_num; i++) {
1078 head = &sock_hash_select_bucket(htab, i)->head;
1079 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1080 struct bpf_shtab_elem, node);
1081 if (elem_next) {
1082 memcpy(key_next, elem_next->key, key_size);
1083 return 0;
1084 }
1085 }
1086
1087 return -ENOENT;
1088 }
1089
1090 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1091 {
1092 struct bpf_shtab *htab;
1093 int i, err;
1094
1095 if (attr->max_entries == 0 ||
1096 attr->key_size == 0 ||
1097 (attr->value_size != sizeof(u32) &&
1098 attr->value_size != sizeof(u64)) ||
1099 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1100 return ERR_PTR(-EINVAL);
1101 if (attr->key_size > MAX_BPF_STACK)
1102 return ERR_PTR(-E2BIG);
1103
1104 htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE);
1105 if (!htab)
1106 return ERR_PTR(-ENOMEM);
1107
1108 bpf_map_init_from_attr(&htab->map, attr);
1109
1110 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1111 htab->elem_size = sizeof(struct bpf_shtab_elem) +
1112 round_up(htab->map.key_size, 8);
1113 if (htab->buckets_num == 0 ||
1114 htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1115 err = -EINVAL;
1116 goto free_htab;
1117 }
1118
1119 htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1120 sizeof(struct bpf_shtab_bucket),
1121 htab->map.numa_node);
1122 if (!htab->buckets) {
1123 err = -ENOMEM;
1124 goto free_htab;
1125 }
1126
1127 for (i = 0; i < htab->buckets_num; i++) {
1128 INIT_HLIST_HEAD(&htab->buckets[i].head);
1129 spin_lock_init(&htab->buckets[i].lock);
1130 }
1131
1132 return &htab->map;
1133 free_htab:
1134 bpf_map_area_free(htab);
1135 return ERR_PTR(err);
1136 }
1137
1138 static void sock_hash_free(struct bpf_map *map)
1139 {
1140 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1141 struct bpf_shtab_bucket *bucket;
1142 struct hlist_head unlink_list;
1143 struct bpf_shtab_elem *elem;
1144 struct hlist_node *node;
1145 int i;
1146
1147 /* After the sync no updates or deletes will be in-flight so it
1148 * is safe to walk map and remove entries without risking a race
1149 * in EEXIST update case.
1150 */
1151 synchronize_rcu();
1152 for (i = 0; i < htab->buckets_num; i++) {
1153 bucket = sock_hash_select_bucket(htab, i);
1154
1155 /* We are racing with sock_hash_delete_from_link to
1156 * enter the spin-lock critical section. Every socket on
1157 * the list is still linked to sockhash. Since link
1158 * exists, psock exists and holds a ref to socket. That
1159 * lets us to grab a socket ref too.
1160 */
1161 spin_lock_bh(&bucket->lock);
1162 hlist_for_each_entry(elem, &bucket->head, node)
1163 sock_hold(elem->sk);
1164 hlist_move_list(&bucket->head, &unlink_list);
1165 spin_unlock_bh(&bucket->lock);
1166
1167 /* Process removed entries out of atomic context to
1168 * block for socket lock before deleting the psock's
1169 * link to sockhash.
1170 */
1171 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1172 hlist_del(&elem->node);
1173 lock_sock(elem->sk);
1174 rcu_read_lock();
1175 sock_map_unref(elem->sk, elem);
1176 rcu_read_unlock();
1177 release_sock(elem->sk);
1178 sock_put(elem->sk);
1179 sock_hash_free_elem(htab, elem);
1180 }
1181 cond_resched();
1182 }
1183
1184 /* wait for psock readers accessing its map link */
1185 synchronize_rcu();
1186
1187 bpf_map_area_free(htab->buckets);
1188 bpf_map_area_free(htab);
1189 }
1190
1191 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1192 {
1193 struct sock *sk;
1194
1195 if (map->value_size != sizeof(u64))
1196 return ERR_PTR(-ENOSPC);
1197
1198 sk = __sock_hash_lookup_elem(map, key);
1199 if (!sk)
1200 return ERR_PTR(-ENOENT);
1201
1202 __sock_gen_cookie(sk);
1203 return &sk->sk_cookie;
1204 }
1205
1206 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1207 {
1208 struct sock *sk;
1209
1210 sk = __sock_hash_lookup_elem(map, key);
1211 if (!sk)
1212 return NULL;
1213 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1214 return NULL;
1215 return sk;
1216 }
1217
1218 static void sock_hash_release_progs(struct bpf_map *map)
1219 {
1220 psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1221 }
1222
1223 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1224 struct bpf_map *, map, void *, key, u64, flags)
1225 {
1226 WARN_ON_ONCE(!rcu_read_lock_held());
1227
1228 if (likely(sock_map_sk_is_suitable(sops->sk) &&
1229 sock_map_op_okay(sops)))
1230 return sock_hash_update_common(map, key, sops->sk, flags);
1231 return -EOPNOTSUPP;
1232 }
1233
1234 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1235 .func = bpf_sock_hash_update,
1236 .gpl_only = false,
1237 .pkt_access = true,
1238 .ret_type = RET_INTEGER,
1239 .arg1_type = ARG_PTR_TO_CTX,
1240 .arg2_type = ARG_CONST_MAP_PTR,
1241 .arg3_type = ARG_PTR_TO_MAP_KEY,
1242 .arg4_type = ARG_ANYTHING,
1243 };
1244
1245 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1246 struct bpf_map *, map, void *, key, u64, flags)
1247 {
1248 struct sock *sk;
1249
1250 if (unlikely(flags & ~(BPF_F_INGRESS)))
1251 return SK_DROP;
1252
1253 sk = __sock_hash_lookup_elem(map, key);
1254 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1255 return SK_DROP;
1256 if ((flags & BPF_F_INGRESS) && sk_is_vsock(sk))
1257 return SK_DROP;
1258
1259 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
1260 return SK_PASS;
1261 }
1262
1263 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1264 .func = bpf_sk_redirect_hash,
1265 .gpl_only = false,
1266 .ret_type = RET_INTEGER,
1267 .arg1_type = ARG_PTR_TO_CTX,
1268 .arg2_type = ARG_CONST_MAP_PTR,
1269 .arg3_type = ARG_PTR_TO_MAP_KEY,
1270 .arg4_type = ARG_ANYTHING,
1271 };
1272
1273 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1274 struct bpf_map *, map, void *, key, u64, flags)
1275 {
1276 struct sock *sk;
1277
1278 if (unlikely(flags & ~(BPF_F_INGRESS)))
1279 return SK_DROP;
1280
1281 sk = __sock_hash_lookup_elem(map, key);
1282 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1283 return SK_DROP;
1284 if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
1285 return SK_DROP;
1286 if (sk_is_vsock(sk))
1287 return SK_DROP;
1288
1289 msg->flags = flags;
1290 msg->sk_redir = sk;
1291 return SK_PASS;
1292 }
1293
1294 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1295 .func = bpf_msg_redirect_hash,
1296 .gpl_only = false,
1297 .ret_type = RET_INTEGER,
1298 .arg1_type = ARG_PTR_TO_CTX,
1299 .arg2_type = ARG_CONST_MAP_PTR,
1300 .arg3_type = ARG_PTR_TO_MAP_KEY,
1301 .arg4_type = ARG_ANYTHING,
1302 };
1303
1304 struct sock_hash_seq_info {
1305 struct bpf_map *map;
1306 struct bpf_shtab *htab;
1307 u32 bucket_id;
1308 };
1309
1310 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1311 struct bpf_shtab_elem *prev_elem)
1312 {
1313 const struct bpf_shtab *htab = info->htab;
1314 struct bpf_shtab_bucket *bucket;
1315 struct bpf_shtab_elem *elem;
1316 struct hlist_node *node;
1317
1318 /* try to find next elem in the same bucket */
1319 if (prev_elem) {
1320 node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1321 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1322 if (elem)
1323 return elem;
1324
1325 /* no more elements, continue in the next bucket */
1326 info->bucket_id++;
1327 }
1328
1329 for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1330 bucket = &htab->buckets[info->bucket_id];
1331 node = rcu_dereference(hlist_first_rcu(&bucket->head));
1332 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1333 if (elem)
1334 return elem;
1335 }
1336
1337 return NULL;
1338 }
1339
1340 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1341 __acquires(rcu)
1342 {
1343 struct sock_hash_seq_info *info = seq->private;
1344
1345 if (*pos == 0)
1346 ++*pos;
1347
1348 /* pairs with sock_hash_seq_stop */
1349 rcu_read_lock();
1350 return sock_hash_seq_find_next(info, NULL);
1351 }
1352
1353 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1354 __must_hold(rcu)
1355 {
1356 struct sock_hash_seq_info *info = seq->private;
1357
1358 ++*pos;
1359 return sock_hash_seq_find_next(info, v);
1360 }
1361
1362 static int sock_hash_seq_show(struct seq_file *seq, void *v)
1363 __must_hold(rcu)
1364 {
1365 struct sock_hash_seq_info *info = seq->private;
1366 struct bpf_iter__sockmap ctx = {};
1367 struct bpf_shtab_elem *elem = v;
1368 struct bpf_iter_meta meta;
1369 struct bpf_prog *prog;
1370
1371 meta.seq = seq;
1372 prog = bpf_iter_get_info(&meta, !elem);
1373 if (!prog)
1374 return 0;
1375
1376 ctx.meta = &meta;
1377 ctx.map = info->map;
1378 if (elem) {
1379 ctx.key = elem->key;
1380 ctx.sk = elem->sk;
1381 }
1382
1383 return bpf_iter_run_prog(prog, &ctx);
1384 }
1385
1386 static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1387 __releases(rcu)
1388 {
1389 if (!v)
1390 (void)sock_hash_seq_show(seq, NULL);
1391
1392 /* pairs with sock_hash_seq_start */
1393 rcu_read_unlock();
1394 }
1395
1396 static const struct seq_operations sock_hash_seq_ops = {
1397 .start = sock_hash_seq_start,
1398 .next = sock_hash_seq_next,
1399 .stop = sock_hash_seq_stop,
1400 .show = sock_hash_seq_show,
1401 };
1402
1403 static int sock_hash_init_seq_private(void *priv_data,
1404 struct bpf_iter_aux_info *aux)
1405 {
1406 struct sock_hash_seq_info *info = priv_data;
1407
1408 bpf_map_inc_with_uref(aux->map);
1409 info->map = aux->map;
1410 info->htab = container_of(aux->map, struct bpf_shtab, map);
1411 return 0;
1412 }
1413
1414 static void sock_hash_fini_seq_private(void *priv_data)
1415 {
1416 struct sock_hash_seq_info *info = priv_data;
1417
1418 bpf_map_put_with_uref(info->map);
1419 }
1420
1421 static u64 sock_hash_mem_usage(const struct bpf_map *map)
1422 {
1423 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1424 u64 usage = sizeof(*htab);
1425
1426 usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket);
1427 usage += atomic_read(&htab->count) * (u64)htab->elem_size;
1428 return usage;
1429 }
1430
1431 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1432 .seq_ops = &sock_hash_seq_ops,
1433 .init_seq_private = sock_hash_init_seq_private,
1434 .fini_seq_private = sock_hash_fini_seq_private,
1435 .seq_priv_size = sizeof(struct sock_hash_seq_info),
1436 };
1437
1438 BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab)
1439 const struct bpf_map_ops sock_hash_ops = {
1440 .map_meta_equal = bpf_map_meta_equal,
1441 .map_alloc = sock_hash_alloc,
1442 .map_free = sock_hash_free,
1443 .map_get_next_key = sock_hash_get_next_key,
1444 .map_update_elem = sock_map_update_elem,
1445 .map_delete_elem = sock_hash_delete_elem,
1446 .map_lookup_elem = sock_hash_lookup,
1447 .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1448 .map_release_uref = sock_hash_release_progs,
1449 .map_check_btf = map_check_no_btf,
1450 .map_mem_usage = sock_hash_mem_usage,
1451 .map_btf_id = &sock_hash_map_btf_ids[0],
1452 .iter_seq_info = &sock_hash_iter_seq_info,
1453 };
1454
1455 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1456 {
1457 switch (map->map_type) {
1458 case BPF_MAP_TYPE_SOCKMAP:
1459 return &container_of(map, struct bpf_stab, map)->progs;
1460 case BPF_MAP_TYPE_SOCKHASH:
1461 return &container_of(map, struct bpf_shtab, map)->progs;
1462 default:
1463 break;
1464 }
1465
1466 return NULL;
1467 }
1468
1469 static int sock_map_prog_link_lookup(struct bpf_map *map, struct bpf_prog ***pprog,
1470 struct bpf_link ***plink, u32 which)
1471 {
1472 struct sk_psock_progs *progs = sock_map_progs(map);
1473 struct bpf_prog **cur_pprog;
1474 struct bpf_link **cur_plink;
1475
1476 if (!progs)
1477 return -EOPNOTSUPP;
1478
1479 switch (which) {
1480 case BPF_SK_MSG_VERDICT:
1481 cur_pprog = &progs->msg_parser;
1482 cur_plink = &progs->msg_parser_link;
1483 break;
1484 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
1485 case BPF_SK_SKB_STREAM_PARSER:
1486 cur_pprog = &progs->stream_parser;
1487 cur_plink = &progs->stream_parser_link;
1488 break;
1489 #endif
1490 case BPF_SK_SKB_STREAM_VERDICT:
1491 if (progs->skb_verdict)
1492 return -EBUSY;
1493 cur_pprog = &progs->stream_verdict;
1494 cur_plink = &progs->stream_verdict_link;
1495 break;
1496 case BPF_SK_SKB_VERDICT:
1497 if (progs->stream_verdict)
1498 return -EBUSY;
1499 cur_pprog = &progs->skb_verdict;
1500 cur_plink = &progs->skb_verdict_link;
1501 break;
1502 default:
1503 return -EOPNOTSUPP;
1504 }
1505
1506 *pprog = cur_pprog;
1507 if (plink)
1508 *plink = cur_plink;
1509 return 0;
1510 }
1511
1512 /* Handle the following four cases:
1513 * prog_attach: prog != NULL, old == NULL, link == NULL
1514 * prog_detach: prog == NULL, old != NULL, link == NULL
1515 * link_attach: prog != NULL, old == NULL, link != NULL
1516 * link_detach: prog == NULL, old != NULL, link != NULL
1517 */
1518 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1519 struct bpf_prog *old, struct bpf_link *link,
1520 u32 which)
1521 {
1522 struct bpf_prog **pprog;
1523 struct bpf_link **plink;
1524 int ret;
1525
1526 ret = sock_map_prog_link_lookup(map, &pprog, &plink, which);
1527 if (ret)
1528 return ret;
1529
1530 /* for prog_attach/prog_detach/link_attach, return error if a bpf_link
1531 * exists for that prog.
1532 */
1533 if ((!link || prog) && *plink)
1534 return -EBUSY;
1535
1536 if (old) {
1537 ret = psock_replace_prog(pprog, prog, old);
1538 if (!ret)
1539 *plink = NULL;
1540 } else {
1541 psock_set_prog(pprog, prog);
1542 if (link)
1543 *plink = link;
1544 }
1545
1546 return ret;
1547 }
1548
1549 int sock_map_bpf_prog_query(const union bpf_attr *attr,
1550 union bpf_attr __user *uattr)
1551 {
1552 __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
1553 u32 prog_cnt = 0, flags = 0;
1554 struct bpf_prog **pprog;
1555 struct bpf_prog *prog;
1556 struct bpf_map *map;
1557 u32 id = 0;
1558 int ret;
1559
1560 if (attr->query.query_flags)
1561 return -EINVAL;
1562
1563 CLASS(fd, f)(attr->target_fd);
1564 map = __bpf_map_get(f);
1565 if (IS_ERR(map))
1566 return PTR_ERR(map);
1567
1568 rcu_read_lock();
1569
1570 ret = sock_map_prog_link_lookup(map, &pprog, NULL, attr->query.attach_type);
1571 if (ret)
1572 goto end;
1573
1574 prog = *pprog;
1575 prog_cnt = !prog ? 0 : 1;
1576
1577 if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
1578 goto end;
1579
1580 /* we do not hold the refcnt, the bpf prog may be released
1581 * asynchronously and the id would be set to 0.
1582 */
1583 id = data_race(prog->aux->id);
1584 if (id == 0)
1585 prog_cnt = 0;
1586
1587 end:
1588 rcu_read_unlock();
1589
1590 if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) ||
1591 (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) ||
1592 copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
1593 ret = -EFAULT;
1594
1595 return ret;
1596 }
1597
1598 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1599 {
1600 switch (link->map->map_type) {
1601 case BPF_MAP_TYPE_SOCKMAP:
1602 return sock_map_delete_from_link(link->map, sk,
1603 link->link_raw);
1604 case BPF_MAP_TYPE_SOCKHASH:
1605 return sock_hash_delete_from_link(link->map, sk,
1606 link->link_raw);
1607 default:
1608 break;
1609 }
1610 }
1611
1612 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1613 {
1614 struct sk_psock_link *link;
1615
1616 while ((link = sk_psock_link_pop(psock))) {
1617 sock_map_unlink(sk, link);
1618 sk_psock_free_link(link);
1619 }
1620 }
1621
1622 void sock_map_unhash(struct sock *sk)
1623 {
1624 void (*saved_unhash)(struct sock *sk);
1625 struct sk_psock *psock;
1626
1627 rcu_read_lock();
1628 psock = sk_psock(sk);
1629 if (unlikely(!psock)) {
1630 rcu_read_unlock();
1631 saved_unhash = READ_ONCE(sk->sk_prot)->unhash;
1632 } else {
1633 saved_unhash = psock->saved_unhash;
1634 sock_map_remove_links(sk, psock);
1635 rcu_read_unlock();
1636 }
1637 if (WARN_ON_ONCE(saved_unhash == sock_map_unhash))
1638 return;
1639 if (saved_unhash)
1640 saved_unhash(sk);
1641 }
1642 EXPORT_SYMBOL_GPL(sock_map_unhash);
1643
1644 void sock_map_destroy(struct sock *sk)
1645 {
1646 void (*saved_destroy)(struct sock *sk);
1647 struct sk_psock *psock;
1648
1649 rcu_read_lock();
1650 psock = sk_psock_get(sk);
1651 if (unlikely(!psock)) {
1652 rcu_read_unlock();
1653 saved_destroy = READ_ONCE(sk->sk_prot)->destroy;
1654 } else {
1655 saved_destroy = psock->saved_destroy;
1656 sock_map_remove_links(sk, psock);
1657 rcu_read_unlock();
1658 sk_psock_stop(psock);
1659 sk_psock_put(sk, psock);
1660 }
1661 if (WARN_ON_ONCE(saved_destroy == sock_map_destroy))
1662 return;
1663 if (saved_destroy)
1664 saved_destroy(sk);
1665 }
1666 EXPORT_SYMBOL_GPL(sock_map_destroy);
1667
1668 void sock_map_close(struct sock *sk, long timeout)
1669 {
1670 void (*saved_close)(struct sock *sk, long timeout);
1671 struct sk_psock *psock;
1672
1673 lock_sock(sk);
1674 rcu_read_lock();
1675 psock = sk_psock(sk);
1676 if (likely(psock)) {
1677 saved_close = psock->saved_close;
1678 sock_map_remove_links(sk, psock);
1679 psock = sk_psock_get(sk);
1680 if (unlikely(!psock))
1681 goto no_psock;
1682 rcu_read_unlock();
1683 sk_psock_stop(psock);
1684 release_sock(sk);
1685 cancel_delayed_work_sync(&psock->work);
1686 sk_psock_put(sk, psock);
1687 } else {
1688 saved_close = READ_ONCE(sk->sk_prot)->close;
1689 no_psock:
1690 rcu_read_unlock();
1691 release_sock(sk);
1692 }
1693
1694 /* Make sure we do not recurse. This is a bug.
1695 * Leak the socket instead of crashing on a stack overflow.
1696 */
1697 if (WARN_ON_ONCE(saved_close == sock_map_close))
1698 return;
1699 saved_close(sk, timeout);
1700 }
1701 EXPORT_SYMBOL_GPL(sock_map_close);
1702
1703 struct sockmap_link {
1704 struct bpf_link link;
1705 struct bpf_map *map;
1706 enum bpf_attach_type attach_type;
1707 };
1708
1709 static void sock_map_link_release(struct bpf_link *link)
1710 {
1711 struct sockmap_link *sockmap_link = container_of(link, struct sockmap_link, link);
1712
1713 mutex_lock(&sockmap_mutex);
1714 if (!sockmap_link->map)
1715 goto out;
1716
1717 WARN_ON_ONCE(sock_map_prog_update(sockmap_link->map, NULL, link->prog, link,
1718 sockmap_link->attach_type));
1719
1720 bpf_map_put_with_uref(sockmap_link->map);
1721 sockmap_link->map = NULL;
1722 out:
1723 mutex_unlock(&sockmap_mutex);
1724 }
1725
1726 static int sock_map_link_detach(struct bpf_link *link)
1727 {
1728 sock_map_link_release(link);
1729 return 0;
1730 }
1731
1732 static void sock_map_link_dealloc(struct bpf_link *link)
1733 {
1734 kfree(link);
1735 }
1736
1737 /* Handle the following two cases:
1738 * case 1: link != NULL, prog != NULL, old != NULL
1739 * case 2: link != NULL, prog != NULL, old == NULL
1740 */
1741 static int sock_map_link_update_prog(struct bpf_link *link,
1742 struct bpf_prog *prog,
1743 struct bpf_prog *old)
1744 {
1745 const struct sockmap_link *sockmap_link = container_of(link, struct sockmap_link, link);
1746 struct bpf_prog **pprog, *old_link_prog;
1747 struct bpf_link **plink;
1748 int ret = 0;
1749
1750 mutex_lock(&sockmap_mutex);
1751
1752 /* If old prog is not NULL, ensure old prog is the same as link->prog. */
1753 if (old && link->prog != old) {
1754 ret = -EPERM;
1755 goto out;
1756 }
1757 /* Ensure link->prog has the same type/attach_type as the new prog. */
1758 if (link->prog->type != prog->type ||
1759 link->prog->expected_attach_type != prog->expected_attach_type) {
1760 ret = -EINVAL;
1761 goto out;
1762 }
1763
1764 ret = sock_map_prog_link_lookup(sockmap_link->map, &pprog, &plink,
1765 sockmap_link->attach_type);
1766 if (ret)
1767 goto out;
1768
1769 /* return error if the stored bpf_link does not match the incoming bpf_link. */
1770 if (link != *plink) {
1771 ret = -EBUSY;
1772 goto out;
1773 }
1774
1775 if (old) {
1776 ret = psock_replace_prog(pprog, prog, old);
1777 if (ret)
1778 goto out;
1779 } else {
1780 psock_set_prog(pprog, prog);
1781 }
1782
1783 bpf_prog_inc(prog);
1784 old_link_prog = xchg(&link->prog, prog);
1785 bpf_prog_put(old_link_prog);
1786
1787 out:
1788 mutex_unlock(&sockmap_mutex);
1789 return ret;
1790 }
1791
1792 static u32 sock_map_link_get_map_id(const struct sockmap_link *sockmap_link)
1793 {
1794 u32 map_id = 0;
1795
1796 mutex_lock(&sockmap_mutex);
1797 if (sockmap_link->map)
1798 map_id = sockmap_link->map->id;
1799 mutex_unlock(&sockmap_mutex);
1800 return map_id;
1801 }
1802
1803 static int sock_map_link_fill_info(const struct bpf_link *link,
1804 struct bpf_link_info *info)
1805 {
1806 const struct sockmap_link *sockmap_link = container_of(link, struct sockmap_link, link);
1807 u32 map_id = sock_map_link_get_map_id(sockmap_link);
1808
1809 info->sockmap.map_id = map_id;
1810 info->sockmap.attach_type = sockmap_link->attach_type;
1811 return 0;
1812 }
1813
1814 static void sock_map_link_show_fdinfo(const struct bpf_link *link,
1815 struct seq_file *seq)
1816 {
1817 const struct sockmap_link *sockmap_link = container_of(link, struct sockmap_link, link);
1818 u32 map_id = sock_map_link_get_map_id(sockmap_link);
1819
1820 seq_printf(seq, "map_id:\t%u\n", map_id);
1821 seq_printf(seq, "attach_type:\t%u\n", sockmap_link->attach_type);
1822 }
1823
1824 static const struct bpf_link_ops sock_map_link_ops = {
1825 .release = sock_map_link_release,
1826 .dealloc = sock_map_link_dealloc,
1827 .detach = sock_map_link_detach,
1828 .update_prog = sock_map_link_update_prog,
1829 .fill_link_info = sock_map_link_fill_info,
1830 .show_fdinfo = sock_map_link_show_fdinfo,
1831 };
1832
1833 int sock_map_link_create(const union bpf_attr *attr, struct bpf_prog *prog)
1834 {
1835 struct bpf_link_primer link_primer;
1836 struct sockmap_link *sockmap_link;
1837 enum bpf_attach_type attach_type;
1838 struct bpf_map *map;
1839 int ret;
1840
1841 if (attr->link_create.flags)
1842 return -EINVAL;
1843
1844 map = bpf_map_get_with_uref(attr->link_create.target_fd);
1845 if (IS_ERR(map))
1846 return PTR_ERR(map);
1847 if (map->map_type != BPF_MAP_TYPE_SOCKMAP && map->map_type != BPF_MAP_TYPE_SOCKHASH) {
1848 ret = -EINVAL;
1849 goto out;
1850 }
1851
1852 sockmap_link = kzalloc(sizeof(*sockmap_link), GFP_USER);
1853 if (!sockmap_link) {
1854 ret = -ENOMEM;
1855 goto out;
1856 }
1857
1858 attach_type = attr->link_create.attach_type;
1859 bpf_link_init(&sockmap_link->link, BPF_LINK_TYPE_SOCKMAP, &sock_map_link_ops, prog);
1860 sockmap_link->map = map;
1861 sockmap_link->attach_type = attach_type;
1862
1863 ret = bpf_link_prime(&sockmap_link->link, &link_primer);
1864 if (ret) {
1865 kfree(sockmap_link);
1866 goto out;
1867 }
1868
1869 mutex_lock(&sockmap_mutex);
1870 ret = sock_map_prog_update(map, prog, NULL, &sockmap_link->link, attach_type);
1871 mutex_unlock(&sockmap_mutex);
1872 if (ret) {
1873 bpf_link_cleanup(&link_primer);
1874 goto out;
1875 }
1876
1877 /* Increase refcnt for the prog since when old prog is replaced with
1878 * psock_replace_prog() and psock_set_prog() its refcnt will be decreased.
1879 *
1880 * Actually, we do not need to increase refcnt for the prog since bpf_link
1881 * will hold a reference. But in order to have less complexity w.r.t.
1882 * replacing/setting prog, let us increase the refcnt to make things simpler.
1883 */
1884 bpf_prog_inc(prog);
1885
1886 return bpf_link_settle(&link_primer);
1887
1888 out:
1889 bpf_map_put_with_uref(map);
1890 return ret;
1891 }
1892
1893 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1894 union bpf_iter_link_info *linfo,
1895 struct bpf_iter_aux_info *aux)
1896 {
1897 struct bpf_map *map;
1898 int err = -EINVAL;
1899
1900 if (!linfo->map.map_fd)
1901 return -EBADF;
1902
1903 map = bpf_map_get_with_uref(linfo->map.map_fd);
1904 if (IS_ERR(map))
1905 return PTR_ERR(map);
1906
1907 if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1908 map->map_type != BPF_MAP_TYPE_SOCKHASH)
1909 goto put_map;
1910
1911 if (prog->aux->max_rdonly_access > map->key_size) {
1912 err = -EACCES;
1913 goto put_map;
1914 }
1915
1916 aux->map = map;
1917 return 0;
1918
1919 put_map:
1920 bpf_map_put_with_uref(map);
1921 return err;
1922 }
1923
1924 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1925 {
1926 bpf_map_put_with_uref(aux->map);
1927 }
1928
1929 static struct bpf_iter_reg sock_map_iter_reg = {
1930 .target = "sockmap",
1931 .attach_target = sock_map_iter_attach_target,
1932 .detach_target = sock_map_iter_detach_target,
1933 .show_fdinfo = bpf_iter_map_show_fdinfo,
1934 .fill_link_info = bpf_iter_map_fill_link_info,
1935 .ctx_arg_info_size = 2,
1936 .ctx_arg_info = {
1937 { offsetof(struct bpf_iter__sockmap, key),
1938 PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY },
1939 { offsetof(struct bpf_iter__sockmap, sk),
1940 PTR_TO_BTF_ID_OR_NULL },
1941 },
1942 };
1943
1944 static int __init bpf_sockmap_iter_init(void)
1945 {
1946 sock_map_iter_reg.ctx_arg_info[1].btf_id =
1947 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1948 return bpf_iter_reg_target(&sock_map_iter_reg);
1949 }
1950 late_initcall(bpf_sockmap_iter_init);
Kernel DRM miscellaneous fixes and cross-tree changes