xref: /openbmc/linux/net/core/sock_map.c (revision 1b1f98dd)
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 	raw_spinlock_t lock;
22 };
23 
24 #define SOCK_CREATE_FLAG_MASK				\
25 	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
26 
27 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
28 				struct bpf_prog *old, u32 which);
29 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map);
30 
31 static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
32 {
33 	struct bpf_stab *stab;
34 
35 	if (!capable(CAP_NET_ADMIN))
36 		return ERR_PTR(-EPERM);
37 	if (attr->max_entries == 0 ||
38 	    attr->key_size    != 4 ||
39 	    (attr->value_size != sizeof(u32) &&
40 	     attr->value_size != sizeof(u64)) ||
41 	    attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
42 		return ERR_PTR(-EINVAL);
43 
44 	stab = kzalloc(sizeof(*stab), GFP_USER | __GFP_ACCOUNT);
45 	if (!stab)
46 		return ERR_PTR(-ENOMEM);
47 
48 	bpf_map_init_from_attr(&stab->map, attr);
49 	raw_spin_lock_init(&stab->lock);
50 
51 	stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries *
52 				       sizeof(struct sock *),
53 				       stab->map.numa_node);
54 	if (!stab->sks) {
55 		kfree(stab);
56 		return ERR_PTR(-ENOMEM);
57 	}
58 
59 	return &stab->map;
60 }
61 
62 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
63 {
64 	u32 ufd = attr->target_fd;
65 	struct bpf_map *map;
66 	struct fd f;
67 	int ret;
68 
69 	if (attr->attach_flags || attr->replace_bpf_fd)
70 		return -EINVAL;
71 
72 	f = fdget(ufd);
73 	map = __bpf_map_get(f);
74 	if (IS_ERR(map))
75 		return PTR_ERR(map);
76 	ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
77 	fdput(f);
78 	return ret;
79 }
80 
81 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
82 {
83 	u32 ufd = attr->target_fd;
84 	struct bpf_prog *prog;
85 	struct bpf_map *map;
86 	struct fd f;
87 	int ret;
88 
89 	if (attr->attach_flags || attr->replace_bpf_fd)
90 		return -EINVAL;
91 
92 	f = fdget(ufd);
93 	map = __bpf_map_get(f);
94 	if (IS_ERR(map))
95 		return PTR_ERR(map);
96 
97 	prog = bpf_prog_get(attr->attach_bpf_fd);
98 	if (IS_ERR(prog)) {
99 		ret = PTR_ERR(prog);
100 		goto put_map;
101 	}
102 
103 	if (prog->type != ptype) {
104 		ret = -EINVAL;
105 		goto put_prog;
106 	}
107 
108 	ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
109 put_prog:
110 	bpf_prog_put(prog);
111 put_map:
112 	fdput(f);
113 	return ret;
114 }
115 
116 static void sock_map_sk_acquire(struct sock *sk)
117 	__acquires(&sk->sk_lock.slock)
118 {
119 	lock_sock(sk);
120 	preempt_disable();
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 	preempt_enable();
129 	release_sock(sk);
130 }
131 
132 static void sock_map_add_link(struct sk_psock *psock,
133 			      struct sk_psock_link *link,
134 			      struct bpf_map *map, void *link_raw)
135 {
136 	link->link_raw = link_raw;
137 	link->map = map;
138 	spin_lock_bh(&psock->link_lock);
139 	list_add_tail(&link->list, &psock->link);
140 	spin_unlock_bh(&psock->link_lock);
141 }
142 
143 static void sock_map_del_link(struct sock *sk,
144 			      struct sk_psock *psock, void *link_raw)
145 {
146 	bool strp_stop = false, verdict_stop = false;
147 	struct sk_psock_link *link, *tmp;
148 
149 	spin_lock_bh(&psock->link_lock);
150 	list_for_each_entry_safe(link, tmp, &psock->link, list) {
151 		if (link->link_raw == link_raw) {
152 			struct bpf_map *map = link->map;
153 			struct bpf_stab *stab = container_of(map, struct bpf_stab,
154 							     map);
155 			if (psock->saved_data_ready && stab->progs.stream_parser)
156 				strp_stop = true;
157 			if (psock->saved_data_ready && stab->progs.stream_verdict)
158 				verdict_stop = true;
159 			if (psock->saved_data_ready && stab->progs.skb_verdict)
160 				verdict_stop = true;
161 			list_del(&link->list);
162 			sk_psock_free_link(link);
163 		}
164 	}
165 	spin_unlock_bh(&psock->link_lock);
166 	if (strp_stop || verdict_stop) {
167 		write_lock_bh(&sk->sk_callback_lock);
168 		if (strp_stop)
169 			sk_psock_stop_strp(sk, psock);
170 		else
171 			sk_psock_stop_verdict(sk, psock);
172 		write_unlock_bh(&sk->sk_callback_lock);
173 	}
174 }
175 
176 static void sock_map_unref(struct sock *sk, void *link_raw)
177 {
178 	struct sk_psock *psock = sk_psock(sk);
179 
180 	if (likely(psock)) {
181 		sock_map_del_link(sk, psock, link_raw);
182 		sk_psock_put(sk, psock);
183 	}
184 }
185 
186 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
187 {
188 	if (!sk->sk_prot->psock_update_sk_prot)
189 		return -EINVAL;
190 	psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot;
191 	return sk->sk_prot->psock_update_sk_prot(sk, psock, false);
192 }
193 
194 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
195 {
196 	struct sk_psock *psock;
197 
198 	rcu_read_lock();
199 	psock = sk_psock(sk);
200 	if (psock) {
201 		if (sk->sk_prot->close != sock_map_close) {
202 			psock = ERR_PTR(-EBUSY);
203 			goto out;
204 		}
205 
206 		if (!refcount_inc_not_zero(&psock->refcnt))
207 			psock = ERR_PTR(-EBUSY);
208 	}
209 out:
210 	rcu_read_unlock();
211 	return psock;
212 }
213 
214 static int sock_map_link(struct bpf_map *map, struct sock *sk)
215 {
216 	struct sk_psock_progs *progs = sock_map_progs(map);
217 	struct bpf_prog *stream_verdict = NULL;
218 	struct bpf_prog *stream_parser = NULL;
219 	struct bpf_prog *skb_verdict = NULL;
220 	struct bpf_prog *msg_parser = NULL;
221 	struct sk_psock *psock;
222 	int ret;
223 
224 	stream_verdict = READ_ONCE(progs->stream_verdict);
225 	if (stream_verdict) {
226 		stream_verdict = bpf_prog_inc_not_zero(stream_verdict);
227 		if (IS_ERR(stream_verdict))
228 			return PTR_ERR(stream_verdict);
229 	}
230 
231 	stream_parser = READ_ONCE(progs->stream_parser);
232 	if (stream_parser) {
233 		stream_parser = bpf_prog_inc_not_zero(stream_parser);
234 		if (IS_ERR(stream_parser)) {
235 			ret = PTR_ERR(stream_parser);
236 			goto out_put_stream_verdict;
237 		}
238 	}
239 
240 	msg_parser = READ_ONCE(progs->msg_parser);
241 	if (msg_parser) {
242 		msg_parser = bpf_prog_inc_not_zero(msg_parser);
243 		if (IS_ERR(msg_parser)) {
244 			ret = PTR_ERR(msg_parser);
245 			goto out_put_stream_parser;
246 		}
247 	}
248 
249 	skb_verdict = READ_ONCE(progs->skb_verdict);
250 	if (skb_verdict) {
251 		skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
252 		if (IS_ERR(skb_verdict)) {
253 			ret = PTR_ERR(skb_verdict);
254 			goto out_put_msg_parser;
255 		}
256 	}
257 
258 	psock = sock_map_psock_get_checked(sk);
259 	if (IS_ERR(psock)) {
260 		ret = PTR_ERR(psock);
261 		goto out_progs;
262 	}
263 
264 	if (psock) {
265 		if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
266 		    (stream_parser  && READ_ONCE(psock->progs.stream_parser)) ||
267 		    (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
268 		    (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) ||
269 		    (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
270 		    (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) {
271 			sk_psock_put(sk, psock);
272 			ret = -EBUSY;
273 			goto out_progs;
274 		}
275 	} else {
276 		psock = sk_psock_init(sk, map->numa_node);
277 		if (IS_ERR(psock)) {
278 			ret = PTR_ERR(psock);
279 			goto out_progs;
280 		}
281 	}
282 
283 	if (msg_parser)
284 		psock_set_prog(&psock->progs.msg_parser, msg_parser);
285 
286 	ret = sock_map_init_proto(sk, psock);
287 	if (ret < 0)
288 		goto out_drop;
289 
290 	write_lock_bh(&sk->sk_callback_lock);
291 	if (stream_parser && stream_verdict && !psock->saved_data_ready) {
292 		ret = sk_psock_init_strp(sk, psock);
293 		if (ret)
294 			goto out_unlock_drop;
295 		psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
296 		psock_set_prog(&psock->progs.stream_parser, stream_parser);
297 		sk_psock_start_strp(sk, psock);
298 	} else if (!stream_parser && stream_verdict && !psock->saved_data_ready) {
299 		psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
300 		sk_psock_start_verdict(sk,psock);
301 	} else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) {
302 		psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
303 		sk_psock_start_verdict(sk, psock);
304 	}
305 	write_unlock_bh(&sk->sk_callback_lock);
306 	return 0;
307 out_unlock_drop:
308 	write_unlock_bh(&sk->sk_callback_lock);
309 out_drop:
310 	sk_psock_put(sk, psock);
311 out_progs:
312 	if (skb_verdict)
313 		bpf_prog_put(skb_verdict);
314 out_put_msg_parser:
315 	if (msg_parser)
316 		bpf_prog_put(msg_parser);
317 out_put_stream_parser:
318 	if (stream_parser)
319 		bpf_prog_put(stream_parser);
320 out_put_stream_verdict:
321 	if (stream_verdict)
322 		bpf_prog_put(stream_verdict);
323 	return ret;
324 }
325 
326 static void sock_map_free(struct bpf_map *map)
327 {
328 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
329 	int i;
330 
331 	/* After the sync no updates or deletes will be in-flight so it
332 	 * is safe to walk map and remove entries without risking a race
333 	 * in EEXIST update case.
334 	 */
335 	synchronize_rcu();
336 	for (i = 0; i < stab->map.max_entries; i++) {
337 		struct sock **psk = &stab->sks[i];
338 		struct sock *sk;
339 
340 		sk = xchg(psk, NULL);
341 		if (sk) {
342 			lock_sock(sk);
343 			rcu_read_lock();
344 			sock_map_unref(sk, psk);
345 			rcu_read_unlock();
346 			release_sock(sk);
347 		}
348 	}
349 
350 	/* wait for psock readers accessing its map link */
351 	synchronize_rcu();
352 
353 	bpf_map_area_free(stab->sks);
354 	kfree(stab);
355 }
356 
357 static void sock_map_release_progs(struct bpf_map *map)
358 {
359 	psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
360 }
361 
362 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
363 {
364 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
365 
366 	WARN_ON_ONCE(!rcu_read_lock_held());
367 
368 	if (unlikely(key >= map->max_entries))
369 		return NULL;
370 	return READ_ONCE(stab->sks[key]);
371 }
372 
373 static void *sock_map_lookup(struct bpf_map *map, void *key)
374 {
375 	struct sock *sk;
376 
377 	sk = __sock_map_lookup_elem(map, *(u32 *)key);
378 	if (!sk)
379 		return NULL;
380 	if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
381 		return NULL;
382 	return sk;
383 }
384 
385 static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
386 {
387 	struct sock *sk;
388 
389 	if (map->value_size != sizeof(u64))
390 		return ERR_PTR(-ENOSPC);
391 
392 	sk = __sock_map_lookup_elem(map, *(u32 *)key);
393 	if (!sk)
394 		return ERR_PTR(-ENOENT);
395 
396 	__sock_gen_cookie(sk);
397 	return &sk->sk_cookie;
398 }
399 
400 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
401 			     struct sock **psk)
402 {
403 	struct sock *sk;
404 	int err = 0;
405 
406 	raw_spin_lock_bh(&stab->lock);
407 	sk = *psk;
408 	if (!sk_test || sk_test == sk)
409 		sk = xchg(psk, NULL);
410 
411 	if (likely(sk))
412 		sock_map_unref(sk, psk);
413 	else
414 		err = -EINVAL;
415 
416 	raw_spin_unlock_bh(&stab->lock);
417 	return err;
418 }
419 
420 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
421 				      void *link_raw)
422 {
423 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
424 
425 	__sock_map_delete(stab, sk, link_raw);
426 }
427 
428 static int sock_map_delete_elem(struct bpf_map *map, void *key)
429 {
430 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
431 	u32 i = *(u32 *)key;
432 	struct sock **psk;
433 
434 	if (unlikely(i >= map->max_entries))
435 		return -EINVAL;
436 
437 	psk = &stab->sks[i];
438 	return __sock_map_delete(stab, NULL, psk);
439 }
440 
441 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
442 {
443 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
444 	u32 i = key ? *(u32 *)key : U32_MAX;
445 	u32 *key_next = next;
446 
447 	if (i == stab->map.max_entries - 1)
448 		return -ENOENT;
449 	if (i >= stab->map.max_entries)
450 		*key_next = 0;
451 	else
452 		*key_next = i + 1;
453 	return 0;
454 }
455 
456 static int sock_map_update_common(struct bpf_map *map, u32 idx,
457 				  struct sock *sk, u64 flags)
458 {
459 	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
460 	struct sk_psock_link *link;
461 	struct sk_psock *psock;
462 	struct sock *osk;
463 	int ret;
464 
465 	WARN_ON_ONCE(!rcu_read_lock_held());
466 	if (unlikely(flags > BPF_EXIST))
467 		return -EINVAL;
468 	if (unlikely(idx >= map->max_entries))
469 		return -E2BIG;
470 
471 	link = sk_psock_init_link();
472 	if (!link)
473 		return -ENOMEM;
474 
475 	ret = sock_map_link(map, sk);
476 	if (ret < 0)
477 		goto out_free;
478 
479 	psock = sk_psock(sk);
480 	WARN_ON_ONCE(!psock);
481 
482 	raw_spin_lock_bh(&stab->lock);
483 	osk = stab->sks[idx];
484 	if (osk && flags == BPF_NOEXIST) {
485 		ret = -EEXIST;
486 		goto out_unlock;
487 	} else if (!osk && flags == BPF_EXIST) {
488 		ret = -ENOENT;
489 		goto out_unlock;
490 	}
491 
492 	sock_map_add_link(psock, link, map, &stab->sks[idx]);
493 	stab->sks[idx] = sk;
494 	if (osk)
495 		sock_map_unref(osk, &stab->sks[idx]);
496 	raw_spin_unlock_bh(&stab->lock);
497 	return 0;
498 out_unlock:
499 	raw_spin_unlock_bh(&stab->lock);
500 	if (psock)
501 		sk_psock_put(sk, psock);
502 out_free:
503 	sk_psock_free_link(link);
504 	return ret;
505 }
506 
507 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
508 {
509 	return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
510 	       ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
511 	       ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
512 }
513 
514 static bool sock_map_redirect_allowed(const struct sock *sk)
515 {
516 	if (sk_is_tcp(sk))
517 		return sk->sk_state != TCP_LISTEN;
518 	else
519 		return sk->sk_state == TCP_ESTABLISHED;
520 }
521 
522 static bool sock_map_sk_is_suitable(const struct sock *sk)
523 {
524 	return !!sk->sk_prot->psock_update_sk_prot;
525 }
526 
527 static bool sock_map_sk_state_allowed(const struct sock *sk)
528 {
529 	if (sk_is_tcp(sk))
530 		return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
531 	return true;
532 }
533 
534 static int sock_hash_update_common(struct bpf_map *map, void *key,
535 				   struct sock *sk, u64 flags);
536 
537 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
538 			     u64 flags)
539 {
540 	struct socket *sock;
541 	struct sock *sk;
542 	int ret;
543 	u64 ufd;
544 
545 	if (map->value_size == sizeof(u64))
546 		ufd = *(u64 *)value;
547 	else
548 		ufd = *(u32 *)value;
549 	if (ufd > S32_MAX)
550 		return -EINVAL;
551 
552 	sock = sockfd_lookup(ufd, &ret);
553 	if (!sock)
554 		return ret;
555 	sk = sock->sk;
556 	if (!sk) {
557 		ret = -EINVAL;
558 		goto out;
559 	}
560 	if (!sock_map_sk_is_suitable(sk)) {
561 		ret = -EOPNOTSUPP;
562 		goto out;
563 	}
564 
565 	sock_map_sk_acquire(sk);
566 	if (!sock_map_sk_state_allowed(sk))
567 		ret = -EOPNOTSUPP;
568 	else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
569 		ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
570 	else
571 		ret = sock_hash_update_common(map, key, sk, flags);
572 	sock_map_sk_release(sk);
573 out:
574 	sockfd_put(sock);
575 	return ret;
576 }
577 
578 static int sock_map_update_elem(struct bpf_map *map, void *key,
579 				void *value, u64 flags)
580 {
581 	struct sock *sk = (struct sock *)value;
582 	int ret;
583 
584 	if (unlikely(!sk || !sk_fullsock(sk)))
585 		return -EINVAL;
586 
587 	if (!sock_map_sk_is_suitable(sk))
588 		return -EOPNOTSUPP;
589 
590 	local_bh_disable();
591 	bh_lock_sock(sk);
592 	if (!sock_map_sk_state_allowed(sk))
593 		ret = -EOPNOTSUPP;
594 	else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
595 		ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
596 	else
597 		ret = sock_hash_update_common(map, key, sk, flags);
598 	bh_unlock_sock(sk);
599 	local_bh_enable();
600 	return ret;
601 }
602 
603 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
604 	   struct bpf_map *, map, void *, key, u64, flags)
605 {
606 	WARN_ON_ONCE(!rcu_read_lock_held());
607 
608 	if (likely(sock_map_sk_is_suitable(sops->sk) &&
609 		   sock_map_op_okay(sops)))
610 		return sock_map_update_common(map, *(u32 *)key, sops->sk,
611 					      flags);
612 	return -EOPNOTSUPP;
613 }
614 
615 const struct bpf_func_proto bpf_sock_map_update_proto = {
616 	.func		= bpf_sock_map_update,
617 	.gpl_only	= false,
618 	.pkt_access	= true,
619 	.ret_type	= RET_INTEGER,
620 	.arg1_type	= ARG_PTR_TO_CTX,
621 	.arg2_type	= ARG_CONST_MAP_PTR,
622 	.arg3_type	= ARG_PTR_TO_MAP_KEY,
623 	.arg4_type	= ARG_ANYTHING,
624 };
625 
626 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
627 	   struct bpf_map *, map, u32, key, u64, flags)
628 {
629 	struct sock *sk;
630 
631 	if (unlikely(flags & ~(BPF_F_INGRESS)))
632 		return SK_DROP;
633 
634 	sk = __sock_map_lookup_elem(map, key);
635 	if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
636 		return SK_DROP;
637 
638 	skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
639 	return SK_PASS;
640 }
641 
642 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
643 	.func           = bpf_sk_redirect_map,
644 	.gpl_only       = false,
645 	.ret_type       = RET_INTEGER,
646 	.arg1_type	= ARG_PTR_TO_CTX,
647 	.arg2_type      = ARG_CONST_MAP_PTR,
648 	.arg3_type      = ARG_ANYTHING,
649 	.arg4_type      = ARG_ANYTHING,
650 };
651 
652 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
653 	   struct bpf_map *, map, u32, key, u64, flags)
654 {
655 	struct sock *sk;
656 
657 	if (unlikely(flags & ~(BPF_F_INGRESS)))
658 		return SK_DROP;
659 
660 	sk = __sock_map_lookup_elem(map, key);
661 	if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
662 		return SK_DROP;
663 
664 	msg->flags = flags;
665 	msg->sk_redir = sk;
666 	return SK_PASS;
667 }
668 
669 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
670 	.func           = bpf_msg_redirect_map,
671 	.gpl_only       = false,
672 	.ret_type       = RET_INTEGER,
673 	.arg1_type	= ARG_PTR_TO_CTX,
674 	.arg2_type      = ARG_CONST_MAP_PTR,
675 	.arg3_type      = ARG_ANYTHING,
676 	.arg4_type      = ARG_ANYTHING,
677 };
678 
679 struct sock_map_seq_info {
680 	struct bpf_map *map;
681 	struct sock *sk;
682 	u32 index;
683 };
684 
685 struct bpf_iter__sockmap {
686 	__bpf_md_ptr(struct bpf_iter_meta *, meta);
687 	__bpf_md_ptr(struct bpf_map *, map);
688 	__bpf_md_ptr(void *, key);
689 	__bpf_md_ptr(struct sock *, sk);
690 };
691 
692 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
693 		     struct bpf_map *map, void *key,
694 		     struct sock *sk)
695 
696 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
697 {
698 	if (unlikely(info->index >= info->map->max_entries))
699 		return NULL;
700 
701 	info->sk = __sock_map_lookup_elem(info->map, info->index);
702 
703 	/* can't return sk directly, since that might be NULL */
704 	return info;
705 }
706 
707 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
708 	__acquires(rcu)
709 {
710 	struct sock_map_seq_info *info = seq->private;
711 
712 	if (*pos == 0)
713 		++*pos;
714 
715 	/* pairs with sock_map_seq_stop */
716 	rcu_read_lock();
717 	return sock_map_seq_lookup_elem(info);
718 }
719 
720 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
721 	__must_hold(rcu)
722 {
723 	struct sock_map_seq_info *info = seq->private;
724 
725 	++*pos;
726 	++info->index;
727 
728 	return sock_map_seq_lookup_elem(info);
729 }
730 
731 static int sock_map_seq_show(struct seq_file *seq, void *v)
732 	__must_hold(rcu)
733 {
734 	struct sock_map_seq_info *info = seq->private;
735 	struct bpf_iter__sockmap ctx = {};
736 	struct bpf_iter_meta meta;
737 	struct bpf_prog *prog;
738 
739 	meta.seq = seq;
740 	prog = bpf_iter_get_info(&meta, !v);
741 	if (!prog)
742 		return 0;
743 
744 	ctx.meta = &meta;
745 	ctx.map = info->map;
746 	if (v) {
747 		ctx.key = &info->index;
748 		ctx.sk = info->sk;
749 	}
750 
751 	return bpf_iter_run_prog(prog, &ctx);
752 }
753 
754 static void sock_map_seq_stop(struct seq_file *seq, void *v)
755 	__releases(rcu)
756 {
757 	if (!v)
758 		(void)sock_map_seq_show(seq, NULL);
759 
760 	/* pairs with sock_map_seq_start */
761 	rcu_read_unlock();
762 }
763 
764 static const struct seq_operations sock_map_seq_ops = {
765 	.start	= sock_map_seq_start,
766 	.next	= sock_map_seq_next,
767 	.stop	= sock_map_seq_stop,
768 	.show	= sock_map_seq_show,
769 };
770 
771 static int sock_map_init_seq_private(void *priv_data,
772 				     struct bpf_iter_aux_info *aux)
773 {
774 	struct sock_map_seq_info *info = priv_data;
775 
776 	info->map = aux->map;
777 	return 0;
778 }
779 
780 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
781 	.seq_ops		= &sock_map_seq_ops,
782 	.init_seq_private	= sock_map_init_seq_private,
783 	.seq_priv_size		= sizeof(struct sock_map_seq_info),
784 };
785 
786 static int sock_map_btf_id;
787 const struct bpf_map_ops sock_map_ops = {
788 	.map_meta_equal		= bpf_map_meta_equal,
789 	.map_alloc		= sock_map_alloc,
790 	.map_free		= sock_map_free,
791 	.map_get_next_key	= sock_map_get_next_key,
792 	.map_lookup_elem_sys_only = sock_map_lookup_sys,
793 	.map_update_elem	= sock_map_update_elem,
794 	.map_delete_elem	= sock_map_delete_elem,
795 	.map_lookup_elem	= sock_map_lookup,
796 	.map_release_uref	= sock_map_release_progs,
797 	.map_check_btf		= map_check_no_btf,
798 	.map_btf_name		= "bpf_stab",
799 	.map_btf_id		= &sock_map_btf_id,
800 	.iter_seq_info		= &sock_map_iter_seq_info,
801 };
802 
803 struct bpf_shtab_elem {
804 	struct rcu_head rcu;
805 	u32 hash;
806 	struct sock *sk;
807 	struct hlist_node node;
808 	u8 key[];
809 };
810 
811 struct bpf_shtab_bucket {
812 	struct hlist_head head;
813 	raw_spinlock_t lock;
814 };
815 
816 struct bpf_shtab {
817 	struct bpf_map map;
818 	struct bpf_shtab_bucket *buckets;
819 	u32 buckets_num;
820 	u32 elem_size;
821 	struct sk_psock_progs progs;
822 	atomic_t count;
823 };
824 
825 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
826 {
827 	return jhash(key, len, 0);
828 }
829 
830 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
831 							u32 hash)
832 {
833 	return &htab->buckets[hash & (htab->buckets_num - 1)];
834 }
835 
836 static struct bpf_shtab_elem *
837 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
838 			  u32 key_size)
839 {
840 	struct bpf_shtab_elem *elem;
841 
842 	hlist_for_each_entry_rcu(elem, head, node) {
843 		if (elem->hash == hash &&
844 		    !memcmp(&elem->key, key, key_size))
845 			return elem;
846 	}
847 
848 	return NULL;
849 }
850 
851 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
852 {
853 	struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
854 	u32 key_size = map->key_size, hash;
855 	struct bpf_shtab_bucket *bucket;
856 	struct bpf_shtab_elem *elem;
857 
858 	WARN_ON_ONCE(!rcu_read_lock_held());
859 
860 	hash = sock_hash_bucket_hash(key, key_size);
861 	bucket = sock_hash_select_bucket(htab, hash);
862 	elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
863 
864 	return elem ? elem->sk : NULL;
865 }
866 
867 static void sock_hash_free_elem(struct bpf_shtab *htab,
868 				struct bpf_shtab_elem *elem)
869 {
870 	atomic_dec(&htab->count);
871 	kfree_rcu(elem, rcu);
872 }
873 
874 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
875 				       void *link_raw)
876 {
877 	struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
878 	struct bpf_shtab_elem *elem_probe, *elem = link_raw;
879 	struct bpf_shtab_bucket *bucket;
880 
881 	WARN_ON_ONCE(!rcu_read_lock_held());
882 	bucket = sock_hash_select_bucket(htab, elem->hash);
883 
884 	/* elem may be deleted in parallel from the map, but access here
885 	 * is okay since it's going away only after RCU grace period.
886 	 * However, we need to check whether it's still present.
887 	 */
888 	raw_spin_lock_bh(&bucket->lock);
889 	elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
890 					       elem->key, map->key_size);
891 	if (elem_probe && elem_probe == elem) {
892 		hlist_del_rcu(&elem->node);
893 		sock_map_unref(elem->sk, elem);
894 		sock_hash_free_elem(htab, elem);
895 	}
896 	raw_spin_unlock_bh(&bucket->lock);
897 }
898 
899 static int sock_hash_delete_elem(struct bpf_map *map, void *key)
900 {
901 	struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
902 	u32 hash, key_size = map->key_size;
903 	struct bpf_shtab_bucket *bucket;
904 	struct bpf_shtab_elem *elem;
905 	int ret = -ENOENT;
906 
907 	hash = sock_hash_bucket_hash(key, key_size);
908 	bucket = sock_hash_select_bucket(htab, hash);
909 
910 	raw_spin_lock_bh(&bucket->lock);
911 	elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
912 	if (elem) {
913 		hlist_del_rcu(&elem->node);
914 		sock_map_unref(elem->sk, elem);
915 		sock_hash_free_elem(htab, elem);
916 		ret = 0;
917 	}
918 	raw_spin_unlock_bh(&bucket->lock);
919 	return ret;
920 }
921 
922 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
923 						   void *key, u32 key_size,
924 						   u32 hash, struct sock *sk,
925 						   struct bpf_shtab_elem *old)
926 {
927 	struct bpf_shtab_elem *new;
928 
929 	if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
930 		if (!old) {
931 			atomic_dec(&htab->count);
932 			return ERR_PTR(-E2BIG);
933 		}
934 	}
935 
936 	new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
937 				   GFP_ATOMIC | __GFP_NOWARN,
938 				   htab->map.numa_node);
939 	if (!new) {
940 		atomic_dec(&htab->count);
941 		return ERR_PTR(-ENOMEM);
942 	}
943 	memcpy(new->key, key, key_size);
944 	new->sk = sk;
945 	new->hash = hash;
946 	return new;
947 }
948 
949 static int sock_hash_update_common(struct bpf_map *map, void *key,
950 				   struct sock *sk, u64 flags)
951 {
952 	struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
953 	u32 key_size = map->key_size, hash;
954 	struct bpf_shtab_elem *elem, *elem_new;
955 	struct bpf_shtab_bucket *bucket;
956 	struct sk_psock_link *link;
957 	struct sk_psock *psock;
958 	int ret;
959 
960 	WARN_ON_ONCE(!rcu_read_lock_held());
961 	if (unlikely(flags > BPF_EXIST))
962 		return -EINVAL;
963 
964 	link = sk_psock_init_link();
965 	if (!link)
966 		return -ENOMEM;
967 
968 	ret = sock_map_link(map, sk);
969 	if (ret < 0)
970 		goto out_free;
971 
972 	psock = sk_psock(sk);
973 	WARN_ON_ONCE(!psock);
974 
975 	hash = sock_hash_bucket_hash(key, key_size);
976 	bucket = sock_hash_select_bucket(htab, hash);
977 
978 	raw_spin_lock_bh(&bucket->lock);
979 	elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
980 	if (elem && flags == BPF_NOEXIST) {
981 		ret = -EEXIST;
982 		goto out_unlock;
983 	} else if (!elem && flags == BPF_EXIST) {
984 		ret = -ENOENT;
985 		goto out_unlock;
986 	}
987 
988 	elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
989 	if (IS_ERR(elem_new)) {
990 		ret = PTR_ERR(elem_new);
991 		goto out_unlock;
992 	}
993 
994 	sock_map_add_link(psock, link, map, elem_new);
995 	/* Add new element to the head of the list, so that
996 	 * concurrent search will find it before old elem.
997 	 */
998 	hlist_add_head_rcu(&elem_new->node, &bucket->head);
999 	if (elem) {
1000 		hlist_del_rcu(&elem->node);
1001 		sock_map_unref(elem->sk, elem);
1002 		sock_hash_free_elem(htab, elem);
1003 	}
1004 	raw_spin_unlock_bh(&bucket->lock);
1005 	return 0;
1006 out_unlock:
1007 	raw_spin_unlock_bh(&bucket->lock);
1008 	sk_psock_put(sk, psock);
1009 out_free:
1010 	sk_psock_free_link(link);
1011 	return ret;
1012 }
1013 
1014 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1015 				  void *key_next)
1016 {
1017 	struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1018 	struct bpf_shtab_elem *elem, *elem_next;
1019 	u32 hash, key_size = map->key_size;
1020 	struct hlist_head *head;
1021 	int i = 0;
1022 
1023 	if (!key)
1024 		goto find_first_elem;
1025 	hash = sock_hash_bucket_hash(key, key_size);
1026 	head = &sock_hash_select_bucket(htab, hash)->head;
1027 	elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1028 	if (!elem)
1029 		goto find_first_elem;
1030 
1031 	elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1032 				     struct bpf_shtab_elem, node);
1033 	if (elem_next) {
1034 		memcpy(key_next, elem_next->key, key_size);
1035 		return 0;
1036 	}
1037 
1038 	i = hash & (htab->buckets_num - 1);
1039 	i++;
1040 find_first_elem:
1041 	for (; i < htab->buckets_num; i++) {
1042 		head = &sock_hash_select_bucket(htab, i)->head;
1043 		elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1044 					     struct bpf_shtab_elem, node);
1045 		if (elem_next) {
1046 			memcpy(key_next, elem_next->key, key_size);
1047 			return 0;
1048 		}
1049 	}
1050 
1051 	return -ENOENT;
1052 }
1053 
1054 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1055 {
1056 	struct bpf_shtab *htab;
1057 	int i, err;
1058 
1059 	if (!capable(CAP_NET_ADMIN))
1060 		return ERR_PTR(-EPERM);
1061 	if (attr->max_entries == 0 ||
1062 	    attr->key_size    == 0 ||
1063 	    (attr->value_size != sizeof(u32) &&
1064 	     attr->value_size != sizeof(u64)) ||
1065 	    attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1066 		return ERR_PTR(-EINVAL);
1067 	if (attr->key_size > MAX_BPF_STACK)
1068 		return ERR_PTR(-E2BIG);
1069 
1070 	htab = kzalloc(sizeof(*htab), GFP_USER | __GFP_ACCOUNT);
1071 	if (!htab)
1072 		return ERR_PTR(-ENOMEM);
1073 
1074 	bpf_map_init_from_attr(&htab->map, attr);
1075 
1076 	htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1077 	htab->elem_size = sizeof(struct bpf_shtab_elem) +
1078 			  round_up(htab->map.key_size, 8);
1079 	if (htab->buckets_num == 0 ||
1080 	    htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1081 		err = -EINVAL;
1082 		goto free_htab;
1083 	}
1084 
1085 	htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1086 					   sizeof(struct bpf_shtab_bucket),
1087 					   htab->map.numa_node);
1088 	if (!htab->buckets) {
1089 		err = -ENOMEM;
1090 		goto free_htab;
1091 	}
1092 
1093 	for (i = 0; i < htab->buckets_num; i++) {
1094 		INIT_HLIST_HEAD(&htab->buckets[i].head);
1095 		raw_spin_lock_init(&htab->buckets[i].lock);
1096 	}
1097 
1098 	return &htab->map;
1099 free_htab:
1100 	kfree(htab);
1101 	return ERR_PTR(err);
1102 }
1103 
1104 static void sock_hash_free(struct bpf_map *map)
1105 {
1106 	struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1107 	struct bpf_shtab_bucket *bucket;
1108 	struct hlist_head unlink_list;
1109 	struct bpf_shtab_elem *elem;
1110 	struct hlist_node *node;
1111 	int i;
1112 
1113 	/* After the sync no updates or deletes will be in-flight so it
1114 	 * is safe to walk map and remove entries without risking a race
1115 	 * in EEXIST update case.
1116 	 */
1117 	synchronize_rcu();
1118 	for (i = 0; i < htab->buckets_num; i++) {
1119 		bucket = sock_hash_select_bucket(htab, i);
1120 
1121 		/* We are racing with sock_hash_delete_from_link to
1122 		 * enter the spin-lock critical section. Every socket on
1123 		 * the list is still linked to sockhash. Since link
1124 		 * exists, psock exists and holds a ref to socket. That
1125 		 * lets us to grab a socket ref too.
1126 		 */
1127 		raw_spin_lock_bh(&bucket->lock);
1128 		hlist_for_each_entry(elem, &bucket->head, node)
1129 			sock_hold(elem->sk);
1130 		hlist_move_list(&bucket->head, &unlink_list);
1131 		raw_spin_unlock_bh(&bucket->lock);
1132 
1133 		/* Process removed entries out of atomic context to
1134 		 * block for socket lock before deleting the psock's
1135 		 * link to sockhash.
1136 		 */
1137 		hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1138 			hlist_del(&elem->node);
1139 			lock_sock(elem->sk);
1140 			rcu_read_lock();
1141 			sock_map_unref(elem->sk, elem);
1142 			rcu_read_unlock();
1143 			release_sock(elem->sk);
1144 			sock_put(elem->sk);
1145 			sock_hash_free_elem(htab, elem);
1146 		}
1147 	}
1148 
1149 	/* wait for psock readers accessing its map link */
1150 	synchronize_rcu();
1151 
1152 	bpf_map_area_free(htab->buckets);
1153 	kfree(htab);
1154 }
1155 
1156 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1157 {
1158 	struct sock *sk;
1159 
1160 	if (map->value_size != sizeof(u64))
1161 		return ERR_PTR(-ENOSPC);
1162 
1163 	sk = __sock_hash_lookup_elem(map, key);
1164 	if (!sk)
1165 		return ERR_PTR(-ENOENT);
1166 
1167 	__sock_gen_cookie(sk);
1168 	return &sk->sk_cookie;
1169 }
1170 
1171 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1172 {
1173 	struct sock *sk;
1174 
1175 	sk = __sock_hash_lookup_elem(map, key);
1176 	if (!sk)
1177 		return NULL;
1178 	if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1179 		return NULL;
1180 	return sk;
1181 }
1182 
1183 static void sock_hash_release_progs(struct bpf_map *map)
1184 {
1185 	psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1186 }
1187 
1188 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1189 	   struct bpf_map *, map, void *, key, u64, flags)
1190 {
1191 	WARN_ON_ONCE(!rcu_read_lock_held());
1192 
1193 	if (likely(sock_map_sk_is_suitable(sops->sk) &&
1194 		   sock_map_op_okay(sops)))
1195 		return sock_hash_update_common(map, key, sops->sk, flags);
1196 	return -EOPNOTSUPP;
1197 }
1198 
1199 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1200 	.func		= bpf_sock_hash_update,
1201 	.gpl_only	= false,
1202 	.pkt_access	= true,
1203 	.ret_type	= RET_INTEGER,
1204 	.arg1_type	= ARG_PTR_TO_CTX,
1205 	.arg2_type	= ARG_CONST_MAP_PTR,
1206 	.arg3_type	= ARG_PTR_TO_MAP_KEY,
1207 	.arg4_type	= ARG_ANYTHING,
1208 };
1209 
1210 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1211 	   struct bpf_map *, map, void *, key, u64, flags)
1212 {
1213 	struct sock *sk;
1214 
1215 	if (unlikely(flags & ~(BPF_F_INGRESS)))
1216 		return SK_DROP;
1217 
1218 	sk = __sock_hash_lookup_elem(map, key);
1219 	if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1220 		return SK_DROP;
1221 
1222 	skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
1223 	return SK_PASS;
1224 }
1225 
1226 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1227 	.func           = bpf_sk_redirect_hash,
1228 	.gpl_only       = false,
1229 	.ret_type       = RET_INTEGER,
1230 	.arg1_type	= ARG_PTR_TO_CTX,
1231 	.arg2_type      = ARG_CONST_MAP_PTR,
1232 	.arg3_type      = ARG_PTR_TO_MAP_KEY,
1233 	.arg4_type      = ARG_ANYTHING,
1234 };
1235 
1236 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1237 	   struct bpf_map *, map, void *, key, u64, flags)
1238 {
1239 	struct sock *sk;
1240 
1241 	if (unlikely(flags & ~(BPF_F_INGRESS)))
1242 		return SK_DROP;
1243 
1244 	sk = __sock_hash_lookup_elem(map, key);
1245 	if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1246 		return SK_DROP;
1247 
1248 	msg->flags = flags;
1249 	msg->sk_redir = sk;
1250 	return SK_PASS;
1251 }
1252 
1253 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1254 	.func           = bpf_msg_redirect_hash,
1255 	.gpl_only       = false,
1256 	.ret_type       = RET_INTEGER,
1257 	.arg1_type	= ARG_PTR_TO_CTX,
1258 	.arg2_type      = ARG_CONST_MAP_PTR,
1259 	.arg3_type      = ARG_PTR_TO_MAP_KEY,
1260 	.arg4_type      = ARG_ANYTHING,
1261 };
1262 
1263 struct sock_hash_seq_info {
1264 	struct bpf_map *map;
1265 	struct bpf_shtab *htab;
1266 	u32 bucket_id;
1267 };
1268 
1269 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1270 				     struct bpf_shtab_elem *prev_elem)
1271 {
1272 	const struct bpf_shtab *htab = info->htab;
1273 	struct bpf_shtab_bucket *bucket;
1274 	struct bpf_shtab_elem *elem;
1275 	struct hlist_node *node;
1276 
1277 	/* try to find next elem in the same bucket */
1278 	if (prev_elem) {
1279 		node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1280 		elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1281 		if (elem)
1282 			return elem;
1283 
1284 		/* no more elements, continue in the next bucket */
1285 		info->bucket_id++;
1286 	}
1287 
1288 	for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1289 		bucket = &htab->buckets[info->bucket_id];
1290 		node = rcu_dereference(hlist_first_rcu(&bucket->head));
1291 		elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1292 		if (elem)
1293 			return elem;
1294 	}
1295 
1296 	return NULL;
1297 }
1298 
1299 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1300 	__acquires(rcu)
1301 {
1302 	struct sock_hash_seq_info *info = seq->private;
1303 
1304 	if (*pos == 0)
1305 		++*pos;
1306 
1307 	/* pairs with sock_hash_seq_stop */
1308 	rcu_read_lock();
1309 	return sock_hash_seq_find_next(info, NULL);
1310 }
1311 
1312 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1313 	__must_hold(rcu)
1314 {
1315 	struct sock_hash_seq_info *info = seq->private;
1316 
1317 	++*pos;
1318 	return sock_hash_seq_find_next(info, v);
1319 }
1320 
1321 static int sock_hash_seq_show(struct seq_file *seq, void *v)
1322 	__must_hold(rcu)
1323 {
1324 	struct sock_hash_seq_info *info = seq->private;
1325 	struct bpf_iter__sockmap ctx = {};
1326 	struct bpf_shtab_elem *elem = v;
1327 	struct bpf_iter_meta meta;
1328 	struct bpf_prog *prog;
1329 
1330 	meta.seq = seq;
1331 	prog = bpf_iter_get_info(&meta, !elem);
1332 	if (!prog)
1333 		return 0;
1334 
1335 	ctx.meta = &meta;
1336 	ctx.map = info->map;
1337 	if (elem) {
1338 		ctx.key = elem->key;
1339 		ctx.sk = elem->sk;
1340 	}
1341 
1342 	return bpf_iter_run_prog(prog, &ctx);
1343 }
1344 
1345 static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1346 	__releases(rcu)
1347 {
1348 	if (!v)
1349 		(void)sock_hash_seq_show(seq, NULL);
1350 
1351 	/* pairs with sock_hash_seq_start */
1352 	rcu_read_unlock();
1353 }
1354 
1355 static const struct seq_operations sock_hash_seq_ops = {
1356 	.start	= sock_hash_seq_start,
1357 	.next	= sock_hash_seq_next,
1358 	.stop	= sock_hash_seq_stop,
1359 	.show	= sock_hash_seq_show,
1360 };
1361 
1362 static int sock_hash_init_seq_private(void *priv_data,
1363 				     struct bpf_iter_aux_info *aux)
1364 {
1365 	struct sock_hash_seq_info *info = priv_data;
1366 
1367 	info->map = aux->map;
1368 	info->htab = container_of(aux->map, struct bpf_shtab, map);
1369 	return 0;
1370 }
1371 
1372 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1373 	.seq_ops		= &sock_hash_seq_ops,
1374 	.init_seq_private	= sock_hash_init_seq_private,
1375 	.seq_priv_size		= sizeof(struct sock_hash_seq_info),
1376 };
1377 
1378 static int sock_hash_map_btf_id;
1379 const struct bpf_map_ops sock_hash_ops = {
1380 	.map_meta_equal		= bpf_map_meta_equal,
1381 	.map_alloc		= sock_hash_alloc,
1382 	.map_free		= sock_hash_free,
1383 	.map_get_next_key	= sock_hash_get_next_key,
1384 	.map_update_elem	= sock_map_update_elem,
1385 	.map_delete_elem	= sock_hash_delete_elem,
1386 	.map_lookup_elem	= sock_hash_lookup,
1387 	.map_lookup_elem_sys_only = sock_hash_lookup_sys,
1388 	.map_release_uref	= sock_hash_release_progs,
1389 	.map_check_btf		= map_check_no_btf,
1390 	.map_btf_name		= "bpf_shtab",
1391 	.map_btf_id		= &sock_hash_map_btf_id,
1392 	.iter_seq_info		= &sock_hash_iter_seq_info,
1393 };
1394 
1395 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1396 {
1397 	switch (map->map_type) {
1398 	case BPF_MAP_TYPE_SOCKMAP:
1399 		return &container_of(map, struct bpf_stab, map)->progs;
1400 	case BPF_MAP_TYPE_SOCKHASH:
1401 		return &container_of(map, struct bpf_shtab, map)->progs;
1402 	default:
1403 		break;
1404 	}
1405 
1406 	return NULL;
1407 }
1408 
1409 static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1410 				struct bpf_prog *old, u32 which)
1411 {
1412 	struct sk_psock_progs *progs = sock_map_progs(map);
1413 	struct bpf_prog **pprog;
1414 
1415 	if (!progs)
1416 		return -EOPNOTSUPP;
1417 
1418 	switch (which) {
1419 	case BPF_SK_MSG_VERDICT:
1420 		pprog = &progs->msg_parser;
1421 		break;
1422 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
1423 	case BPF_SK_SKB_STREAM_PARSER:
1424 		pprog = &progs->stream_parser;
1425 		break;
1426 #endif
1427 	case BPF_SK_SKB_STREAM_VERDICT:
1428 		if (progs->skb_verdict)
1429 			return -EBUSY;
1430 		pprog = &progs->stream_verdict;
1431 		break;
1432 	case BPF_SK_SKB_VERDICT:
1433 		if (progs->stream_verdict)
1434 			return -EBUSY;
1435 		pprog = &progs->skb_verdict;
1436 		break;
1437 	default:
1438 		return -EOPNOTSUPP;
1439 	}
1440 
1441 	if (old)
1442 		return psock_replace_prog(pprog, prog, old);
1443 
1444 	psock_set_prog(pprog, prog);
1445 	return 0;
1446 }
1447 
1448 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1449 {
1450 	switch (link->map->map_type) {
1451 	case BPF_MAP_TYPE_SOCKMAP:
1452 		return sock_map_delete_from_link(link->map, sk,
1453 						 link->link_raw);
1454 	case BPF_MAP_TYPE_SOCKHASH:
1455 		return sock_hash_delete_from_link(link->map, sk,
1456 						  link->link_raw);
1457 	default:
1458 		break;
1459 	}
1460 }
1461 
1462 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1463 {
1464 	struct sk_psock_link *link;
1465 
1466 	while ((link = sk_psock_link_pop(psock))) {
1467 		sock_map_unlink(sk, link);
1468 		sk_psock_free_link(link);
1469 	}
1470 }
1471 
1472 void sock_map_unhash(struct sock *sk)
1473 {
1474 	void (*saved_unhash)(struct sock *sk);
1475 	struct sk_psock *psock;
1476 
1477 	rcu_read_lock();
1478 	psock = sk_psock(sk);
1479 	if (unlikely(!psock)) {
1480 		rcu_read_unlock();
1481 		if (sk->sk_prot->unhash)
1482 			sk->sk_prot->unhash(sk);
1483 		return;
1484 	}
1485 
1486 	saved_unhash = psock->saved_unhash;
1487 	sock_map_remove_links(sk, psock);
1488 	rcu_read_unlock();
1489 	saved_unhash(sk);
1490 }
1491 EXPORT_SYMBOL_GPL(sock_map_unhash);
1492 
1493 void sock_map_close(struct sock *sk, long timeout)
1494 {
1495 	void (*saved_close)(struct sock *sk, long timeout);
1496 	struct sk_psock *psock;
1497 
1498 	lock_sock(sk);
1499 	rcu_read_lock();
1500 	psock = sk_psock_get(sk);
1501 	if (unlikely(!psock)) {
1502 		rcu_read_unlock();
1503 		release_sock(sk);
1504 		return sk->sk_prot->close(sk, timeout);
1505 	}
1506 
1507 	saved_close = psock->saved_close;
1508 	sock_map_remove_links(sk, psock);
1509 	rcu_read_unlock();
1510 	sk_psock_stop(psock, true);
1511 	sk_psock_put(sk, psock);
1512 	release_sock(sk);
1513 	saved_close(sk, timeout);
1514 }
1515 EXPORT_SYMBOL_GPL(sock_map_close);
1516 
1517 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1518 				       union bpf_iter_link_info *linfo,
1519 				       struct bpf_iter_aux_info *aux)
1520 {
1521 	struct bpf_map *map;
1522 	int err = -EINVAL;
1523 
1524 	if (!linfo->map.map_fd)
1525 		return -EBADF;
1526 
1527 	map = bpf_map_get_with_uref(linfo->map.map_fd);
1528 	if (IS_ERR(map))
1529 		return PTR_ERR(map);
1530 
1531 	if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1532 	    map->map_type != BPF_MAP_TYPE_SOCKHASH)
1533 		goto put_map;
1534 
1535 	if (prog->aux->max_rdonly_access > map->key_size) {
1536 		err = -EACCES;
1537 		goto put_map;
1538 	}
1539 
1540 	aux->map = map;
1541 	return 0;
1542 
1543 put_map:
1544 	bpf_map_put_with_uref(map);
1545 	return err;
1546 }
1547 
1548 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1549 {
1550 	bpf_map_put_with_uref(aux->map);
1551 }
1552 
1553 static struct bpf_iter_reg sock_map_iter_reg = {
1554 	.target			= "sockmap",
1555 	.attach_target		= sock_map_iter_attach_target,
1556 	.detach_target		= sock_map_iter_detach_target,
1557 	.show_fdinfo		= bpf_iter_map_show_fdinfo,
1558 	.fill_link_info		= bpf_iter_map_fill_link_info,
1559 	.ctx_arg_info_size	= 2,
1560 	.ctx_arg_info		= {
1561 		{ offsetof(struct bpf_iter__sockmap, key),
1562 		  PTR_TO_RDONLY_BUF_OR_NULL },
1563 		{ offsetof(struct bpf_iter__sockmap, sk),
1564 		  PTR_TO_BTF_ID_OR_NULL },
1565 	},
1566 };
1567 
1568 static int __init bpf_sockmap_iter_init(void)
1569 {
1570 	sock_map_iter_reg.ctx_arg_info[1].btf_id =
1571 		btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1572 	return bpf_iter_reg_target(&sock_map_iter_reg);
1573 }
1574 late_initcall(bpf_sockmap_iter_init);
1575