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