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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/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 raw_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 (!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 = bpf_map_area_alloc(sizeof(*stab), NUMA_NO_NODE);
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 bpf_map_area_free(stab);
56 return ERR_PTR(-ENOMEM);
57 }
58
59 return &stab->map;
60}
61
62int 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
81int 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);
109put_prog:
110 bpf_prog_put(prog);
111put_map:
112 fdput(f);
113 return ret;
114}
115
116static 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
124static 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
132static 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
143static 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 if (verdict_stop)
171 sk_psock_stop_verdict(sk, psock);
172
173 if (psock->psock_update_sk_prot)
174 psock->psock_update_sk_prot(sk, psock, false);
175 write_unlock_bh(&sk->sk_callback_lock);
176 }
177}
178
179static void sock_map_unref(struct sock *sk, void *link_raw)
180{
181 struct sk_psock *psock = sk_psock(sk);
182
183 if (likely(psock)) {
184 sock_map_del_link(sk, psock, link_raw);
185 sk_psock_put(sk, psock);
186 }
187}
188
189static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
190{
191 if (!sk->sk_prot->psock_update_sk_prot)
192 return -EINVAL;
193 psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot;
194 return sk->sk_prot->psock_update_sk_prot(sk, psock, false);
195}
196
197static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
198{
199 struct sk_psock *psock;
200
201 rcu_read_lock();
202 psock = sk_psock(sk);
203 if (psock) {
204 if (sk->sk_prot->close != sock_map_close) {
205 psock = ERR_PTR(-EBUSY);
206 goto out;
207 }
208
209 if (!refcount_inc_not_zero(&psock->refcnt))
210 psock = ERR_PTR(-EBUSY);
211 }
212out:
213 rcu_read_unlock();
214 return psock;
215}
216
217static int sock_map_link(struct bpf_map *map, struct sock *sk)
218{
219 struct sk_psock_progs *progs = sock_map_progs(map);
220 struct bpf_prog *stream_verdict = NULL;
221 struct bpf_prog *stream_parser = NULL;
222 struct bpf_prog *skb_verdict = NULL;
223 struct bpf_prog *msg_parser = NULL;
224 struct sk_psock *psock;
225 int ret;
226
227 stream_verdict = READ_ONCE(progs->stream_verdict);
228 if (stream_verdict) {
229 stream_verdict = bpf_prog_inc_not_zero(stream_verdict);
230 if (IS_ERR(stream_verdict))
231 return PTR_ERR(stream_verdict);
232 }
233
234 stream_parser = READ_ONCE(progs->stream_parser);
235 if (stream_parser) {
236 stream_parser = bpf_prog_inc_not_zero(stream_parser);
237 if (IS_ERR(stream_parser)) {
238 ret = PTR_ERR(stream_parser);
239 goto out_put_stream_verdict;
240 }
241 }
242
243 msg_parser = READ_ONCE(progs->msg_parser);
244 if (msg_parser) {
245 msg_parser = bpf_prog_inc_not_zero(msg_parser);
246 if (IS_ERR(msg_parser)) {
247 ret = PTR_ERR(msg_parser);
248 goto out_put_stream_parser;
249 }
250 }
251
252 skb_verdict = READ_ONCE(progs->skb_verdict);
253 if (skb_verdict) {
254 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
255 if (IS_ERR(skb_verdict)) {
256 ret = PTR_ERR(skb_verdict);
257 goto out_put_msg_parser;
258 }
259 }
260
261 psock = sock_map_psock_get_checked(sk);
262 if (IS_ERR(psock)) {
263 ret = PTR_ERR(psock);
264 goto out_progs;
265 }
266
267 if (psock) {
268 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
269 (stream_parser && READ_ONCE(psock->progs.stream_parser)) ||
270 (skb_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
271 (skb_verdict && READ_ONCE(psock->progs.stream_verdict)) ||
272 (stream_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
273 (stream_verdict && READ_ONCE(psock->progs.stream_verdict))) {
274 sk_psock_put(sk, psock);
275 ret = -EBUSY;
276 goto out_progs;
277 }
278 } else {
279 psock = sk_psock_init(sk, map->numa_node);
280 if (IS_ERR(psock)) {
281 ret = PTR_ERR(psock);
282 goto out_progs;
283 }
284 }
285
286 if (msg_parser)
287 psock_set_prog(&psock->progs.msg_parser, msg_parser);
288 if (stream_parser)
289 psock_set_prog(&psock->progs.stream_parser, stream_parser);
290 if (stream_verdict)
291 psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
292 if (skb_verdict)
293 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
294
295 /* msg_* and stream_* programs references tracked in psock after this
296 * point. Reference dec and cleanup will occur through psock destructor
297 */
298 ret = sock_map_init_proto(sk, psock);
299 if (ret < 0) {
300 sk_psock_put(sk, psock);
301 goto out;
302 }
303
304 write_lock_bh(&sk->sk_callback_lock);
305 if (stream_parser && stream_verdict && !psock->saved_data_ready) {
306 ret = sk_psock_init_strp(sk, psock);
307 if (ret) {
308 write_unlock_bh(&sk->sk_callback_lock);
309 sk_psock_put(sk, psock);
310 goto out;
311 }
312 sk_psock_start_strp(sk, psock);
313 } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) {
314 sk_psock_start_verdict(sk,psock);
315 } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) {
316 sk_psock_start_verdict(sk, psock);
317 }
318 write_unlock_bh(&sk->sk_callback_lock);
319 return 0;
320out_progs:
321 if (skb_verdict)
322 bpf_prog_put(skb_verdict);
323out_put_msg_parser:
324 if (msg_parser)
325 bpf_prog_put(msg_parser);
326out_put_stream_parser:
327 if (stream_parser)
328 bpf_prog_put(stream_parser);
329out_put_stream_verdict:
330 if (stream_verdict)
331 bpf_prog_put(stream_verdict);
332out:
333 return ret;
334}
335
336static void sock_map_free(struct bpf_map *map)
337{
338 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
339 int i;
340
341 /* After the sync no updates or deletes will be in-flight so it
342 * is safe to walk map and remove entries without risking a race
343 * in EEXIST update case.
344 */
345 synchronize_rcu();
346 for (i = 0; i < stab->map.max_entries; i++) {
347 struct sock **psk = &stab->sks[i];
348 struct sock *sk;
349
350 sk = xchg(psk, NULL);
351 if (sk) {
352 sock_hold(sk);
353 lock_sock(sk);
354 rcu_read_lock();
355 sock_map_unref(sk, psk);
356 rcu_read_unlock();
357 release_sock(sk);
358 sock_put(sk);
359 }
360 }
361
362 /* wait for psock readers accessing its map link */
363 synchronize_rcu();
364
365 bpf_map_area_free(stab->sks);
366 bpf_map_area_free(stab);
367}
368
369static void sock_map_release_progs(struct bpf_map *map)
370{
371 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
372}
373
374static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
375{
376 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
377
378 WARN_ON_ONCE(!rcu_read_lock_held());
379
380 if (unlikely(key >= map->max_entries))
381 return NULL;
382 return READ_ONCE(stab->sks[key]);
383}
384
385static void *sock_map_lookup(struct bpf_map *map, void *key)
386{
387 struct sock *sk;
388
389 sk = __sock_map_lookup_elem(map, *(u32 *)key);
390 if (!sk)
391 return NULL;
392 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
393 return NULL;
394 return sk;
395}
396
397static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
398{
399 struct sock *sk;
400
401 if (map->value_size != sizeof(u64))
402 return ERR_PTR(-ENOSPC);
403
404 sk = __sock_map_lookup_elem(map, *(u32 *)key);
405 if (!sk)
406 return ERR_PTR(-ENOENT);
407
408 __sock_gen_cookie(sk);
409 return &sk->sk_cookie;
410}
411
412static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
413 struct sock **psk)
414{
415 struct sock *sk;
416 int err = 0;
417
418 raw_spin_lock_bh(&stab->lock);
419 sk = *psk;
420 if (!sk_test || sk_test == sk)
421 sk = xchg(psk, NULL);
422
423 if (likely(sk))
424 sock_map_unref(sk, psk);
425 else
426 err = -EINVAL;
427
428 raw_spin_unlock_bh(&stab->lock);
429 return err;
430}
431
432static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
433 void *link_raw)
434{
435 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
436
437 __sock_map_delete(stab, sk, link_raw);
438}
439
440static int sock_map_delete_elem(struct bpf_map *map, void *key)
441{
442 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
443 u32 i = *(u32 *)key;
444 struct sock **psk;
445
446 if (unlikely(i >= map->max_entries))
447 return -EINVAL;
448
449 psk = &stab->sks[i];
450 return __sock_map_delete(stab, NULL, psk);
451}
452
453static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
454{
455 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
456 u32 i = key ? *(u32 *)key : U32_MAX;
457 u32 *key_next = next;
458
459 if (i == stab->map.max_entries - 1)
460 return -ENOENT;
461 if (i >= stab->map.max_entries)
462 *key_next = 0;
463 else
464 *key_next = i + 1;
465 return 0;
466}
467
468static int sock_map_update_common(struct bpf_map *map, u32 idx,
469 struct sock *sk, u64 flags)
470{
471 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
472 struct sk_psock_link *link;
473 struct sk_psock *psock;
474 struct sock *osk;
475 int ret;
476
477 WARN_ON_ONCE(!rcu_read_lock_held());
478 if (unlikely(flags > BPF_EXIST))
479 return -EINVAL;
480 if (unlikely(idx >= map->max_entries))
481 return -E2BIG;
482
483 link = sk_psock_init_link();
484 if (!link)
485 return -ENOMEM;
486
487 ret = sock_map_link(map, sk);
488 if (ret < 0)
489 goto out_free;
490
491 psock = sk_psock(sk);
492 WARN_ON_ONCE(!psock);
493
494 raw_spin_lock_bh(&stab->lock);
495 osk = stab->sks[idx];
496 if (osk && flags == BPF_NOEXIST) {
497 ret = -EEXIST;
498 goto out_unlock;
499 } else if (!osk && flags == BPF_EXIST) {
500 ret = -ENOENT;
501 goto out_unlock;
502 }
503
504 sock_map_add_link(psock, link, map, &stab->sks[idx]);
505 stab->sks[idx] = sk;
506 if (osk)
507 sock_map_unref(osk, &stab->sks[idx]);
508 raw_spin_unlock_bh(&stab->lock);
509 return 0;
510out_unlock:
511 raw_spin_unlock_bh(&stab->lock);
512 if (psock)
513 sk_psock_put(sk, psock);
514out_free:
515 sk_psock_free_link(link);
516 return ret;
517}
518
519static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
520{
521 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
522 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
523 ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
524}
525
526static bool sock_map_redirect_allowed(const struct sock *sk)
527{
528 if (sk_is_tcp(sk))
529 return sk->sk_state != TCP_LISTEN;
530 else
531 return sk->sk_state == TCP_ESTABLISHED;
532}
533
534static bool sock_map_sk_is_suitable(const struct sock *sk)
535{
536 return !!sk->sk_prot->psock_update_sk_prot;
537}
538
539static bool sock_map_sk_state_allowed(const struct sock *sk)
540{
541 if (sk_is_tcp(sk))
542 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
543 return true;
544}
545
546static int sock_hash_update_common(struct bpf_map *map, void *key,
547 struct sock *sk, u64 flags);
548
549int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
550 u64 flags)
551{
552 struct socket *sock;
553 struct sock *sk;
554 int ret;
555 u64 ufd;
556
557 if (map->value_size == sizeof(u64))
558 ufd = *(u64 *)value;
559 else
560 ufd = *(u32 *)value;
561 if (ufd > S32_MAX)
562 return -EINVAL;
563
564 sock = sockfd_lookup(ufd, &ret);
565 if (!sock)
566 return ret;
567 sk = sock->sk;
568 if (!sk) {
569 ret = -EINVAL;
570 goto out;
571 }
572 if (!sock_map_sk_is_suitable(sk)) {
573 ret = -EOPNOTSUPP;
574 goto out;
575 }
576
577 sock_map_sk_acquire(sk);
578 if (!sock_map_sk_state_allowed(sk))
579 ret = -EOPNOTSUPP;
580 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
581 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
582 else
583 ret = sock_hash_update_common(map, key, sk, flags);
584 sock_map_sk_release(sk);
585out:
586 sockfd_put(sock);
587 return ret;
588}
589
590static int sock_map_update_elem(struct bpf_map *map, void *key,
591 void *value, u64 flags)
592{
593 struct sock *sk = (struct sock *)value;
594 int ret;
595
596 if (unlikely(!sk || !sk_fullsock(sk)))
597 return -EINVAL;
598
599 if (!sock_map_sk_is_suitable(sk))
600 return -EOPNOTSUPP;
601
602 local_bh_disable();
603 bh_lock_sock(sk);
604 if (!sock_map_sk_state_allowed(sk))
605 ret = -EOPNOTSUPP;
606 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
607 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
608 else
609 ret = sock_hash_update_common(map, key, sk, flags);
610 bh_unlock_sock(sk);
611 local_bh_enable();
612 return ret;
613}
614
615BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
616 struct bpf_map *, map, void *, key, u64, flags)
617{
618 WARN_ON_ONCE(!rcu_read_lock_held());
619
620 if (likely(sock_map_sk_is_suitable(sops->sk) &&
621 sock_map_op_okay(sops)))
622 return sock_map_update_common(map, *(u32 *)key, sops->sk,
623 flags);
624 return -EOPNOTSUPP;
625}
626
627const struct bpf_func_proto bpf_sock_map_update_proto = {
628 .func = bpf_sock_map_update,
629 .gpl_only = false,
630 .pkt_access = true,
631 .ret_type = RET_INTEGER,
632 .arg1_type = ARG_PTR_TO_CTX,
633 .arg2_type = ARG_CONST_MAP_PTR,
634 .arg3_type = ARG_PTR_TO_MAP_KEY,
635 .arg4_type = ARG_ANYTHING,
636};
637
638BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
639 struct bpf_map *, map, u32, key, u64, flags)
640{
641 struct sock *sk;
642
643 if (unlikely(flags & ~(BPF_F_INGRESS)))
644 return SK_DROP;
645
646 sk = __sock_map_lookup_elem(map, key);
647 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
648 return SK_DROP;
649
650 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
651 return SK_PASS;
652}
653
654const struct bpf_func_proto bpf_sk_redirect_map_proto = {
655 .func = bpf_sk_redirect_map,
656 .gpl_only = false,
657 .ret_type = RET_INTEGER,
658 .arg1_type = ARG_PTR_TO_CTX,
659 .arg2_type = ARG_CONST_MAP_PTR,
660 .arg3_type = ARG_ANYTHING,
661 .arg4_type = ARG_ANYTHING,
662};
663
664BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
665 struct bpf_map *, map, u32, key, u64, flags)
666{
667 struct sock *sk;
668
669 if (unlikely(flags & ~(BPF_F_INGRESS)))
670 return SK_DROP;
671
672 sk = __sock_map_lookup_elem(map, key);
673 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
674 return SK_DROP;
675
676 msg->flags = flags;
677 msg->sk_redir = sk;
678 return SK_PASS;
679}
680
681const struct bpf_func_proto bpf_msg_redirect_map_proto = {
682 .func = bpf_msg_redirect_map,
683 .gpl_only = false,
684 .ret_type = RET_INTEGER,
685 .arg1_type = ARG_PTR_TO_CTX,
686 .arg2_type = ARG_CONST_MAP_PTR,
687 .arg3_type = ARG_ANYTHING,
688 .arg4_type = ARG_ANYTHING,
689};
690
691struct sock_map_seq_info {
692 struct bpf_map *map;
693 struct sock *sk;
694 u32 index;
695};
696
697struct bpf_iter__sockmap {
698 __bpf_md_ptr(struct bpf_iter_meta *, meta);
699 __bpf_md_ptr(struct bpf_map *, map);
700 __bpf_md_ptr(void *, key);
701 __bpf_md_ptr(struct sock *, sk);
702};
703
704DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
705 struct bpf_map *map, void *key,
706 struct sock *sk)
707
708static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
709{
710 if (unlikely(info->index >= info->map->max_entries))
711 return NULL;
712
713 info->sk = __sock_map_lookup_elem(info->map, info->index);
714
715 /* can't return sk directly, since that might be NULL */
716 return info;
717}
718
719static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
720 __acquires(rcu)
721{
722 struct sock_map_seq_info *info = seq->private;
723
724 if (*pos == 0)
725 ++*pos;
726
727 /* pairs with sock_map_seq_stop */
728 rcu_read_lock();
729 return sock_map_seq_lookup_elem(info);
730}
731
732static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
733 __must_hold(rcu)
734{
735 struct sock_map_seq_info *info = seq->private;
736
737 ++*pos;
738 ++info->index;
739
740 return sock_map_seq_lookup_elem(info);
741}
742
743static int sock_map_seq_show(struct seq_file *seq, void *v)
744 __must_hold(rcu)
745{
746 struct sock_map_seq_info *info = seq->private;
747 struct bpf_iter__sockmap ctx = {};
748 struct bpf_iter_meta meta;
749 struct bpf_prog *prog;
750
751 meta.seq = seq;
752 prog = bpf_iter_get_info(&meta, !v);
753 if (!prog)
754 return 0;
755
756 ctx.meta = &meta;
757 ctx.map = info->map;
758 if (v) {
759 ctx.key = &info->index;
760 ctx.sk = info->sk;
761 }
762
763 return bpf_iter_run_prog(prog, &ctx);
764}
765
766static void sock_map_seq_stop(struct seq_file *seq, void *v)
767 __releases(rcu)
768{
769 if (!v)
770 (void)sock_map_seq_show(seq, NULL);
771
772 /* pairs with sock_map_seq_start */
773 rcu_read_unlock();
774}
775
776static const struct seq_operations sock_map_seq_ops = {
777 .start = sock_map_seq_start,
778 .next = sock_map_seq_next,
779 .stop = sock_map_seq_stop,
780 .show = sock_map_seq_show,
781};
782
783static int sock_map_init_seq_private(void *priv_data,
784 struct bpf_iter_aux_info *aux)
785{
786 struct sock_map_seq_info *info = priv_data;
787
788 bpf_map_inc_with_uref(aux->map);
789 info->map = aux->map;
790 return 0;
791}
792
793static void sock_map_fini_seq_private(void *priv_data)
794{
795 struct sock_map_seq_info *info = priv_data;
796
797 bpf_map_put_with_uref(info->map);
798}
799
800static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
801 .seq_ops = &sock_map_seq_ops,
802 .init_seq_private = sock_map_init_seq_private,
803 .fini_seq_private = sock_map_fini_seq_private,
804 .seq_priv_size = sizeof(struct sock_map_seq_info),
805};
806
807BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab)
808const struct bpf_map_ops sock_map_ops = {
809 .map_meta_equal = bpf_map_meta_equal,
810 .map_alloc = sock_map_alloc,
811 .map_free = sock_map_free,
812 .map_get_next_key = sock_map_get_next_key,
813 .map_lookup_elem_sys_only = sock_map_lookup_sys,
814 .map_update_elem = sock_map_update_elem,
815 .map_delete_elem = sock_map_delete_elem,
816 .map_lookup_elem = sock_map_lookup,
817 .map_release_uref = sock_map_release_progs,
818 .map_check_btf = map_check_no_btf,
819 .map_btf_id = &sock_map_btf_ids[0],
820 .iter_seq_info = &sock_map_iter_seq_info,
821};
822
823struct bpf_shtab_elem {
824 struct rcu_head rcu;
825 u32 hash;
826 struct sock *sk;
827 struct hlist_node node;
828 u8 key[];
829};
830
831struct bpf_shtab_bucket {
832 struct hlist_head head;
833 raw_spinlock_t lock;
834};
835
836struct bpf_shtab {
837 struct bpf_map map;
838 struct bpf_shtab_bucket *buckets;
839 u32 buckets_num;
840 u32 elem_size;
841 struct sk_psock_progs progs;
842 atomic_t count;
843};
844
845static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
846{
847 return jhash(key, len, 0);
848}
849
850static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
851 u32 hash)
852{
853 return &htab->buckets[hash & (htab->buckets_num - 1)];
854}
855
856static struct bpf_shtab_elem *
857sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
858 u32 key_size)
859{
860 struct bpf_shtab_elem *elem;
861
862 hlist_for_each_entry_rcu(elem, head, node) {
863 if (elem->hash == hash &&
864 !memcmp(&elem->key, key, key_size))
865 return elem;
866 }
867
868 return NULL;
869}
870
871static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
872{
873 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
874 u32 key_size = map->key_size, hash;
875 struct bpf_shtab_bucket *bucket;
876 struct bpf_shtab_elem *elem;
877
878 WARN_ON_ONCE(!rcu_read_lock_held());
879
880 hash = sock_hash_bucket_hash(key, key_size);
881 bucket = sock_hash_select_bucket(htab, hash);
882 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
883
884 return elem ? elem->sk : NULL;
885}
886
887static void sock_hash_free_elem(struct bpf_shtab *htab,
888 struct bpf_shtab_elem *elem)
889{
890 atomic_dec(&htab->count);
891 kfree_rcu(elem, rcu);
892}
893
894static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
895 void *link_raw)
896{
897 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
898 struct bpf_shtab_elem *elem_probe, *elem = link_raw;
899 struct bpf_shtab_bucket *bucket;
900
901 WARN_ON_ONCE(!rcu_read_lock_held());
902 bucket = sock_hash_select_bucket(htab, elem->hash);
903
904 /* elem may be deleted in parallel from the map, but access here
905 * is okay since it's going away only after RCU grace period.
906 * However, we need to check whether it's still present.
907 */
908 raw_spin_lock_bh(&bucket->lock);
909 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
910 elem->key, map->key_size);
911 if (elem_probe && elem_probe == elem) {
912 hlist_del_rcu(&elem->node);
913 sock_map_unref(elem->sk, elem);
914 sock_hash_free_elem(htab, elem);
915 }
916 raw_spin_unlock_bh(&bucket->lock);
917}
918
919static int sock_hash_delete_elem(struct bpf_map *map, void *key)
920{
921 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
922 u32 hash, key_size = map->key_size;
923 struct bpf_shtab_bucket *bucket;
924 struct bpf_shtab_elem *elem;
925 int ret = -ENOENT;
926
927 hash = sock_hash_bucket_hash(key, key_size);
928 bucket = sock_hash_select_bucket(htab, hash);
929
930 raw_spin_lock_bh(&bucket->lock);
931 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
932 if (elem) {
933 hlist_del_rcu(&elem->node);
934 sock_map_unref(elem->sk, elem);
935 sock_hash_free_elem(htab, elem);
936 ret = 0;
937 }
938 raw_spin_unlock_bh(&bucket->lock);
939 return ret;
940}
941
942static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
943 void *key, u32 key_size,
944 u32 hash, struct sock *sk,
945 struct bpf_shtab_elem *old)
946{
947 struct bpf_shtab_elem *new;
948
949 if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
950 if (!old) {
951 atomic_dec(&htab->count);
952 return ERR_PTR(-E2BIG);
953 }
954 }
955
956 new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
957 GFP_ATOMIC | __GFP_NOWARN,
958 htab->map.numa_node);
959 if (!new) {
960 atomic_dec(&htab->count);
961 return ERR_PTR(-ENOMEM);
962 }
963 memcpy(new->key, key, key_size);
964 new->sk = sk;
965 new->hash = hash;
966 return new;
967}
968
969static int sock_hash_update_common(struct bpf_map *map, void *key,
970 struct sock *sk, u64 flags)
971{
972 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
973 u32 key_size = map->key_size, hash;
974 struct bpf_shtab_elem *elem, *elem_new;
975 struct bpf_shtab_bucket *bucket;
976 struct sk_psock_link *link;
977 struct sk_psock *psock;
978 int ret;
979
980 WARN_ON_ONCE(!rcu_read_lock_held());
981 if (unlikely(flags > BPF_EXIST))
982 return -EINVAL;
983
984 link = sk_psock_init_link();
985 if (!link)
986 return -ENOMEM;
987
988 ret = sock_map_link(map, sk);
989 if (ret < 0)
990 goto out_free;
991
992 psock = sk_psock(sk);
993 WARN_ON_ONCE(!psock);
994
995 hash = sock_hash_bucket_hash(key, key_size);
996 bucket = sock_hash_select_bucket(htab, hash);
997
998 raw_spin_lock_bh(&bucket->lock);
999 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1000 if (elem && flags == BPF_NOEXIST) {
1001 ret = -EEXIST;
1002 goto out_unlock;
1003 } else if (!elem && flags == BPF_EXIST) {
1004 ret = -ENOENT;
1005 goto out_unlock;
1006 }
1007
1008 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1009 if (IS_ERR(elem_new)) {
1010 ret = PTR_ERR(elem_new);
1011 goto out_unlock;
1012 }
1013
1014 sock_map_add_link(psock, link, map, elem_new);
1015 /* Add new element to the head of the list, so that
1016 * concurrent search will find it before old elem.
1017 */
1018 hlist_add_head_rcu(&elem_new->node, &bucket->head);
1019 if (elem) {
1020 hlist_del_rcu(&elem->node);
1021 sock_map_unref(elem->sk, elem);
1022 sock_hash_free_elem(htab, elem);
1023 }
1024 raw_spin_unlock_bh(&bucket->lock);
1025 return 0;
1026out_unlock:
1027 raw_spin_unlock_bh(&bucket->lock);
1028 sk_psock_put(sk, psock);
1029out_free:
1030 sk_psock_free_link(link);
1031 return ret;
1032}
1033
1034static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1035 void *key_next)
1036{
1037 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1038 struct bpf_shtab_elem *elem, *elem_next;
1039 u32 hash, key_size = map->key_size;
1040 struct hlist_head *head;
1041 int i = 0;
1042
1043 if (!key)
1044 goto find_first_elem;
1045 hash = sock_hash_bucket_hash(key, key_size);
1046 head = &sock_hash_select_bucket(htab, hash)->head;
1047 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1048 if (!elem)
1049 goto find_first_elem;
1050
1051 elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1052 struct bpf_shtab_elem, node);
1053 if (elem_next) {
1054 memcpy(key_next, elem_next->key, key_size);
1055 return 0;
1056 }
1057
1058 i = hash & (htab->buckets_num - 1);
1059 i++;
1060find_first_elem:
1061 for (; i < htab->buckets_num; i++) {
1062 head = &sock_hash_select_bucket(htab, i)->head;
1063 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1064 struct bpf_shtab_elem, node);
1065 if (elem_next) {
1066 memcpy(key_next, elem_next->key, key_size);
1067 return 0;
1068 }
1069 }
1070
1071 return -ENOENT;
1072}
1073
1074static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1075{
1076 struct bpf_shtab *htab;
1077 int i, err;
1078
1079 if (!capable(CAP_NET_ADMIN))
1080 return ERR_PTR(-EPERM);
1081 if (attr->max_entries == 0 ||
1082 attr->key_size == 0 ||
1083 (attr->value_size != sizeof(u32) &&
1084 attr->value_size != sizeof(u64)) ||
1085 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1086 return ERR_PTR(-EINVAL);
1087 if (attr->key_size > MAX_BPF_STACK)
1088 return ERR_PTR(-E2BIG);
1089
1090 htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE);
1091 if (!htab)
1092 return ERR_PTR(-ENOMEM);
1093
1094 bpf_map_init_from_attr(&htab->map, attr);
1095
1096 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1097 htab->elem_size = sizeof(struct bpf_shtab_elem) +
1098 round_up(htab->map.key_size, 8);
1099 if (htab->buckets_num == 0 ||
1100 htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1101 err = -EINVAL;
1102 goto free_htab;
1103 }
1104
1105 htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1106 sizeof(struct bpf_shtab_bucket),
1107 htab->map.numa_node);
1108 if (!htab->buckets) {
1109 err = -ENOMEM;
1110 goto free_htab;
1111 }
1112
1113 for (i = 0; i < htab->buckets_num; i++) {
1114 INIT_HLIST_HEAD(&htab->buckets[i].head);
1115 raw_spin_lock_init(&htab->buckets[i].lock);
1116 }
1117
1118 return &htab->map;
1119free_htab:
1120 bpf_map_area_free(htab);
1121 return ERR_PTR(err);
1122}
1123
1124static void sock_hash_free(struct bpf_map *map)
1125{
1126 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1127 struct bpf_shtab_bucket *bucket;
1128 struct hlist_head unlink_list;
1129 struct bpf_shtab_elem *elem;
1130 struct hlist_node *node;
1131 int i;
1132
1133 /* After the sync no updates or deletes will be in-flight so it
1134 * is safe to walk map and remove entries without risking a race
1135 * in EEXIST update case.
1136 */
1137 synchronize_rcu();
1138 for (i = 0; i < htab->buckets_num; i++) {
1139 bucket = sock_hash_select_bucket(htab, i);
1140
1141 /* We are racing with sock_hash_delete_from_link to
1142 * enter the spin-lock critical section. Every socket on
1143 * the list is still linked to sockhash. Since link
1144 * exists, psock exists and holds a ref to socket. That
1145 * lets us to grab a socket ref too.
1146 */
1147 raw_spin_lock_bh(&bucket->lock);
1148 hlist_for_each_entry(elem, &bucket->head, node)
1149 sock_hold(elem->sk);
1150 hlist_move_list(&bucket->head, &unlink_list);
1151 raw_spin_unlock_bh(&bucket->lock);
1152
1153 /* Process removed entries out of atomic context to
1154 * block for socket lock before deleting the psock's
1155 * link to sockhash.
1156 */
1157 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1158 hlist_del(&elem->node);
1159 lock_sock(elem->sk);
1160 rcu_read_lock();
1161 sock_map_unref(elem->sk, elem);
1162 rcu_read_unlock();
1163 release_sock(elem->sk);
1164 sock_put(elem->sk);
1165 sock_hash_free_elem(htab, elem);
1166 }
1167 }
1168
1169 /* wait for psock readers accessing its map link */
1170 synchronize_rcu();
1171
1172 bpf_map_area_free(htab->buckets);
1173 bpf_map_area_free(htab);
1174}
1175
1176static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1177{
1178 struct sock *sk;
1179
1180 if (map->value_size != sizeof(u64))
1181 return ERR_PTR(-ENOSPC);
1182
1183 sk = __sock_hash_lookup_elem(map, key);
1184 if (!sk)
1185 return ERR_PTR(-ENOENT);
1186
1187 __sock_gen_cookie(sk);
1188 return &sk->sk_cookie;
1189}
1190
1191static void *sock_hash_lookup(struct bpf_map *map, void *key)
1192{
1193 struct sock *sk;
1194
1195 sk = __sock_hash_lookup_elem(map, key);
1196 if (!sk)
1197 return NULL;
1198 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1199 return NULL;
1200 return sk;
1201}
1202
1203static void sock_hash_release_progs(struct bpf_map *map)
1204{
1205 psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1206}
1207
1208BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1209 struct bpf_map *, map, void *, key, u64, flags)
1210{
1211 WARN_ON_ONCE(!rcu_read_lock_held());
1212
1213 if (likely(sock_map_sk_is_suitable(sops->sk) &&
1214 sock_map_op_okay(sops)))
1215 return sock_hash_update_common(map, key, sops->sk, flags);
1216 return -EOPNOTSUPP;
1217}
1218
1219const struct bpf_func_proto bpf_sock_hash_update_proto = {
1220 .func = bpf_sock_hash_update,
1221 .gpl_only = false,
1222 .pkt_access = true,
1223 .ret_type = RET_INTEGER,
1224 .arg1_type = ARG_PTR_TO_CTX,
1225 .arg2_type = ARG_CONST_MAP_PTR,
1226 .arg3_type = ARG_PTR_TO_MAP_KEY,
1227 .arg4_type = ARG_ANYTHING,
1228};
1229
1230BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1231 struct bpf_map *, map, void *, key, u64, flags)
1232{
1233 struct sock *sk;
1234
1235 if (unlikely(flags & ~(BPF_F_INGRESS)))
1236 return SK_DROP;
1237
1238 sk = __sock_hash_lookup_elem(map, key);
1239 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1240 return SK_DROP;
1241
1242 skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
1243 return SK_PASS;
1244}
1245
1246const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1247 .func = bpf_sk_redirect_hash,
1248 .gpl_only = false,
1249 .ret_type = RET_INTEGER,
1250 .arg1_type = ARG_PTR_TO_CTX,
1251 .arg2_type = ARG_CONST_MAP_PTR,
1252 .arg3_type = ARG_PTR_TO_MAP_KEY,
1253 .arg4_type = ARG_ANYTHING,
1254};
1255
1256BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1257 struct bpf_map *, map, void *, key, u64, flags)
1258{
1259 struct sock *sk;
1260
1261 if (unlikely(flags & ~(BPF_F_INGRESS)))
1262 return SK_DROP;
1263
1264 sk = __sock_hash_lookup_elem(map, key);
1265 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1266 return SK_DROP;
1267
1268 msg->flags = flags;
1269 msg->sk_redir = sk;
1270 return SK_PASS;
1271}
1272
1273const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1274 .func = bpf_msg_redirect_hash,
1275 .gpl_only = false,
1276 .ret_type = RET_INTEGER,
1277 .arg1_type = ARG_PTR_TO_CTX,
1278 .arg2_type = ARG_CONST_MAP_PTR,
1279 .arg3_type = ARG_PTR_TO_MAP_KEY,
1280 .arg4_type = ARG_ANYTHING,
1281};
1282
1283struct sock_hash_seq_info {
1284 struct bpf_map *map;
1285 struct bpf_shtab *htab;
1286 u32 bucket_id;
1287};
1288
1289static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1290 struct bpf_shtab_elem *prev_elem)
1291{
1292 const struct bpf_shtab *htab = info->htab;
1293 struct bpf_shtab_bucket *bucket;
1294 struct bpf_shtab_elem *elem;
1295 struct hlist_node *node;
1296
1297 /* try to find next elem in the same bucket */
1298 if (prev_elem) {
1299 node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1300 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1301 if (elem)
1302 return elem;
1303
1304 /* no more elements, continue in the next bucket */
1305 info->bucket_id++;
1306 }
1307
1308 for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1309 bucket = &htab->buckets[info->bucket_id];
1310 node = rcu_dereference(hlist_first_rcu(&bucket->head));
1311 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1312 if (elem)
1313 return elem;
1314 }
1315
1316 return NULL;
1317}
1318
1319static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1320 __acquires(rcu)
1321{
1322 struct sock_hash_seq_info *info = seq->private;
1323
1324 if (*pos == 0)
1325 ++*pos;
1326
1327 /* pairs with sock_hash_seq_stop */
1328 rcu_read_lock();
1329 return sock_hash_seq_find_next(info, NULL);
1330}
1331
1332static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1333 __must_hold(rcu)
1334{
1335 struct sock_hash_seq_info *info = seq->private;
1336
1337 ++*pos;
1338 return sock_hash_seq_find_next(info, v);
1339}
1340
1341static int sock_hash_seq_show(struct seq_file *seq, void *v)
1342 __must_hold(rcu)
1343{
1344 struct sock_hash_seq_info *info = seq->private;
1345 struct bpf_iter__sockmap ctx = {};
1346 struct bpf_shtab_elem *elem = v;
1347 struct bpf_iter_meta meta;
1348 struct bpf_prog *prog;
1349
1350 meta.seq = seq;
1351 prog = bpf_iter_get_info(&meta, !elem);
1352 if (!prog)
1353 return 0;
1354
1355 ctx.meta = &meta;
1356 ctx.map = info->map;
1357 if (elem) {
1358 ctx.key = elem->key;
1359 ctx.sk = elem->sk;
1360 }
1361
1362 return bpf_iter_run_prog(prog, &ctx);
1363}
1364
1365static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1366 __releases(rcu)
1367{
1368 if (!v)
1369 (void)sock_hash_seq_show(seq, NULL);
1370
1371 /* pairs with sock_hash_seq_start */
1372 rcu_read_unlock();
1373}
1374
1375static const struct seq_operations sock_hash_seq_ops = {
1376 .start = sock_hash_seq_start,
1377 .next = sock_hash_seq_next,
1378 .stop = sock_hash_seq_stop,
1379 .show = sock_hash_seq_show,
1380};
1381
1382static int sock_hash_init_seq_private(void *priv_data,
1383 struct bpf_iter_aux_info *aux)
1384{
1385 struct sock_hash_seq_info *info = priv_data;
1386
1387 bpf_map_inc_with_uref(aux->map);
1388 info->map = aux->map;
1389 info->htab = container_of(aux->map, struct bpf_shtab, map);
1390 return 0;
1391}
1392
1393static void sock_hash_fini_seq_private(void *priv_data)
1394{
1395 struct sock_hash_seq_info *info = priv_data;
1396
1397 bpf_map_put_with_uref(info->map);
1398}
1399
1400static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1401 .seq_ops = &sock_hash_seq_ops,
1402 .init_seq_private = sock_hash_init_seq_private,
1403 .fini_seq_private = sock_hash_fini_seq_private,
1404 .seq_priv_size = sizeof(struct sock_hash_seq_info),
1405};
1406
1407BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab)
1408const struct bpf_map_ops sock_hash_ops = {
1409 .map_meta_equal = bpf_map_meta_equal,
1410 .map_alloc = sock_hash_alloc,
1411 .map_free = sock_hash_free,
1412 .map_get_next_key = sock_hash_get_next_key,
1413 .map_update_elem = sock_map_update_elem,
1414 .map_delete_elem = sock_hash_delete_elem,
1415 .map_lookup_elem = sock_hash_lookup,
1416 .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1417 .map_release_uref = sock_hash_release_progs,
1418 .map_check_btf = map_check_no_btf,
1419 .map_btf_id = &sock_hash_map_btf_ids[0],
1420 .iter_seq_info = &sock_hash_iter_seq_info,
1421};
1422
1423static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1424{
1425 switch (map->map_type) {
1426 case BPF_MAP_TYPE_SOCKMAP:
1427 return &container_of(map, struct bpf_stab, map)->progs;
1428 case BPF_MAP_TYPE_SOCKHASH:
1429 return &container_of(map, struct bpf_shtab, map)->progs;
1430 default:
1431 break;
1432 }
1433
1434 return NULL;
1435}
1436
1437static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog,
1438 u32 which)
1439{
1440 struct sk_psock_progs *progs = sock_map_progs(map);
1441
1442 if (!progs)
1443 return -EOPNOTSUPP;
1444
1445 switch (which) {
1446 case BPF_SK_MSG_VERDICT:
1447 *pprog = &progs->msg_parser;
1448 break;
1449#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
1450 case BPF_SK_SKB_STREAM_PARSER:
1451 *pprog = &progs->stream_parser;
1452 break;
1453#endif
1454 case BPF_SK_SKB_STREAM_VERDICT:
1455 if (progs->skb_verdict)
1456 return -EBUSY;
1457 *pprog = &progs->stream_verdict;
1458 break;
1459 case BPF_SK_SKB_VERDICT:
1460 if (progs->stream_verdict)
1461 return -EBUSY;
1462 *pprog = &progs->skb_verdict;
1463 break;
1464 default:
1465 return -EOPNOTSUPP;
1466 }
1467
1468 return 0;
1469}
1470
1471static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1472 struct bpf_prog *old, u32 which)
1473{
1474 struct bpf_prog **pprog;
1475 int ret;
1476
1477 ret = sock_map_prog_lookup(map, &pprog, which);
1478 if (ret)
1479 return ret;
1480
1481 if (old)
1482 return psock_replace_prog(pprog, prog, old);
1483
1484 psock_set_prog(pprog, prog);
1485 return 0;
1486}
1487
1488int sock_map_bpf_prog_query(const union bpf_attr *attr,
1489 union bpf_attr __user *uattr)
1490{
1491 __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
1492 u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd;
1493 struct bpf_prog **pprog;
1494 struct bpf_prog *prog;
1495 struct bpf_map *map;
1496 struct fd f;
1497 u32 id = 0;
1498 int ret;
1499
1500 if (attr->query.query_flags)
1501 return -EINVAL;
1502
1503 f = fdget(ufd);
1504 map = __bpf_map_get(f);
1505 if (IS_ERR(map))
1506 return PTR_ERR(map);
1507
1508 rcu_read_lock();
1509
1510 ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type);
1511 if (ret)
1512 goto end;
1513
1514 prog = *pprog;
1515 prog_cnt = !prog ? 0 : 1;
1516
1517 if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
1518 goto end;
1519
1520 /* we do not hold the refcnt, the bpf prog may be released
1521 * asynchronously and the id would be set to 0.
1522 */
1523 id = data_race(prog->aux->id);
1524 if (id == 0)
1525 prog_cnt = 0;
1526
1527end:
1528 rcu_read_unlock();
1529
1530 if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) ||
1531 (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) ||
1532 copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
1533 ret = -EFAULT;
1534
1535 fdput(f);
1536 return ret;
1537}
1538
1539static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1540{
1541 switch (link->map->map_type) {
1542 case BPF_MAP_TYPE_SOCKMAP:
1543 return sock_map_delete_from_link(link->map, sk,
1544 link->link_raw);
1545 case BPF_MAP_TYPE_SOCKHASH:
1546 return sock_hash_delete_from_link(link->map, sk,
1547 link->link_raw);
1548 default:
1549 break;
1550 }
1551}
1552
1553static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1554{
1555 struct sk_psock_link *link;
1556
1557 while ((link = sk_psock_link_pop(psock))) {
1558 sock_map_unlink(sk, link);
1559 sk_psock_free_link(link);
1560 }
1561}
1562
1563void sock_map_unhash(struct sock *sk)
1564{
1565 void (*saved_unhash)(struct sock *sk);
1566 struct sk_psock *psock;
1567
1568 rcu_read_lock();
1569 psock = sk_psock(sk);
1570 if (unlikely(!psock)) {
1571 rcu_read_unlock();
1572 saved_unhash = READ_ONCE(sk->sk_prot)->unhash;
1573 } else {
1574 saved_unhash = psock->saved_unhash;
1575 sock_map_remove_links(sk, psock);
1576 rcu_read_unlock();
1577 }
1578 if (WARN_ON_ONCE(saved_unhash == sock_map_unhash))
1579 return;
1580 if (saved_unhash)
1581 saved_unhash(sk);
1582}
1583EXPORT_SYMBOL_GPL(sock_map_unhash);
1584
1585void sock_map_destroy(struct sock *sk)
1586{
1587 void (*saved_destroy)(struct sock *sk);
1588 struct sk_psock *psock;
1589
1590 rcu_read_lock();
1591 psock = sk_psock_get(sk);
1592 if (unlikely(!psock)) {
1593 rcu_read_unlock();
1594 saved_destroy = READ_ONCE(sk->sk_prot)->destroy;
1595 } else {
1596 saved_destroy = psock->saved_destroy;
1597 sock_map_remove_links(sk, psock);
1598 rcu_read_unlock();
1599 sk_psock_stop(psock);
1600 sk_psock_put(sk, psock);
1601 }
1602 if (WARN_ON_ONCE(saved_destroy == sock_map_destroy))
1603 return;
1604 if (saved_destroy)
1605 saved_destroy(sk);
1606}
1607EXPORT_SYMBOL_GPL(sock_map_destroy);
1608
1609void sock_map_close(struct sock *sk, long timeout)
1610{
1611 void (*saved_close)(struct sock *sk, long timeout);
1612 struct sk_psock *psock;
1613
1614 lock_sock(sk);
1615 rcu_read_lock();
1616 psock = sk_psock_get(sk);
1617 if (unlikely(!psock)) {
1618 rcu_read_unlock();
1619 release_sock(sk);
1620 saved_close = READ_ONCE(sk->sk_prot)->close;
1621 } else {
1622 saved_close = psock->saved_close;
1623 sock_map_remove_links(sk, psock);
1624 rcu_read_unlock();
1625 sk_psock_stop(psock);
1626 release_sock(sk);
1627 cancel_work_sync(&psock->work);
1628 sk_psock_put(sk, psock);
1629 }
1630 /* Make sure we do not recurse. This is a bug.
1631 * Leak the socket instead of crashing on a stack overflow.
1632 */
1633 if (WARN_ON_ONCE(saved_close == sock_map_close))
1634 return;
1635 saved_close(sk, timeout);
1636}
1637EXPORT_SYMBOL_GPL(sock_map_close);
1638
1639static int sock_map_iter_attach_target(struct bpf_prog *prog,
1640 union bpf_iter_link_info *linfo,
1641 struct bpf_iter_aux_info *aux)
1642{
1643 struct bpf_map *map;
1644 int err = -EINVAL;
1645
1646 if (!linfo->map.map_fd)
1647 return -EBADF;
1648
1649 map = bpf_map_get_with_uref(linfo->map.map_fd);
1650 if (IS_ERR(map))
1651 return PTR_ERR(map);
1652
1653 if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1654 map->map_type != BPF_MAP_TYPE_SOCKHASH)
1655 goto put_map;
1656
1657 if (prog->aux->max_rdonly_access > map->key_size) {
1658 err = -EACCES;
1659 goto put_map;
1660 }
1661
1662 aux->map = map;
1663 return 0;
1664
1665put_map:
1666 bpf_map_put_with_uref(map);
1667 return err;
1668}
1669
1670static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1671{
1672 bpf_map_put_with_uref(aux->map);
1673}
1674
1675static struct bpf_iter_reg sock_map_iter_reg = {
1676 .target = "sockmap",
1677 .attach_target = sock_map_iter_attach_target,
1678 .detach_target = sock_map_iter_detach_target,
1679 .show_fdinfo = bpf_iter_map_show_fdinfo,
1680 .fill_link_info = bpf_iter_map_fill_link_info,
1681 .ctx_arg_info_size = 2,
1682 .ctx_arg_info = {
1683 { offsetof(struct bpf_iter__sockmap, key),
1684 PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY },
1685 { offsetof(struct bpf_iter__sockmap, sk),
1686 PTR_TO_BTF_ID_OR_NULL },
1687 },
1688};
1689
1690static int __init bpf_sockmap_iter_init(void)
1691{
1692 sock_map_iter_reg.ctx_arg_info[1].btf_id =
1693 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1694 return bpf_iter_reg_target(&sock_map_iter_reg);
1695}
1696late_initcall(bpf_sockmap_iter_init);
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);