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1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
3
4#include <linux/bpf.h>
5#include <linux/filter.h>
6#include <linux/errno.h>
7#include <linux/file.h>
8#include <linux/net.h>
9#include <linux/workqueue.h>
10#include <linux/skmsg.h>
11#include <linux/list.h>
12#include <linux/jhash.h>
13
14struct bpf_stab {
15 struct bpf_map map;
16 struct sock **sks;
17 struct sk_psock_progs progs;
18 raw_spinlock_t lock;
19};
20
21#define SOCK_CREATE_FLAG_MASK \
22 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
23
24static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
25{
26 struct bpf_stab *stab;
27 u64 cost;
28 int err;
29
30 if (!capable(CAP_NET_ADMIN))
31 return ERR_PTR(-EPERM);
32 if (attr->max_entries == 0 ||
33 attr->key_size != 4 ||
34 attr->value_size != 4 ||
35 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
36 return ERR_PTR(-EINVAL);
37
38 stab = kzalloc(sizeof(*stab), GFP_USER);
39 if (!stab)
40 return ERR_PTR(-ENOMEM);
41
42 bpf_map_init_from_attr(&stab->map, attr);
43 raw_spin_lock_init(&stab->lock);
44
45 /* Make sure page count doesn't overflow. */
46 cost = (u64) stab->map.max_entries * sizeof(struct sock *);
47 err = bpf_map_charge_init(&stab->map.memory, cost);
48 if (err)
49 goto free_stab;
50
51 stab->sks = bpf_map_area_alloc(stab->map.max_entries *
52 sizeof(struct sock *),
53 stab->map.numa_node);
54 if (stab->sks)
55 return &stab->map;
56 err = -ENOMEM;
57 bpf_map_charge_finish(&stab->map.memory);
58free_stab:
59 kfree(stab);
60 return ERR_PTR(err);
61}
62
63int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
64{
65 u32 ufd = attr->target_fd;
66 struct bpf_map *map;
67 struct fd f;
68 int ret;
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, attr->attach_type);
75 fdput(f);
76 return ret;
77}
78
79static void sock_map_sk_acquire(struct sock *sk)
80 __acquires(&sk->sk_lock.slock)
81{
82 lock_sock(sk);
83 preempt_disable();
84 rcu_read_lock();
85}
86
87static void sock_map_sk_release(struct sock *sk)
88 __releases(&sk->sk_lock.slock)
89{
90 rcu_read_unlock();
91 preempt_enable();
92 release_sock(sk);
93}
94
95static void sock_map_add_link(struct sk_psock *psock,
96 struct sk_psock_link *link,
97 struct bpf_map *map, void *link_raw)
98{
99 link->link_raw = link_raw;
100 link->map = map;
101 spin_lock_bh(&psock->link_lock);
102 list_add_tail(&link->list, &psock->link);
103 spin_unlock_bh(&psock->link_lock);
104}
105
106static void sock_map_del_link(struct sock *sk,
107 struct sk_psock *psock, void *link_raw)
108{
109 struct sk_psock_link *link, *tmp;
110 bool strp_stop = false;
111
112 spin_lock_bh(&psock->link_lock);
113 list_for_each_entry_safe(link, tmp, &psock->link, list) {
114 if (link->link_raw == link_raw) {
115 struct bpf_map *map = link->map;
116 struct bpf_stab *stab = container_of(map, struct bpf_stab,
117 map);
118 if (psock->parser.enabled && stab->progs.skb_parser)
119 strp_stop = true;
120 list_del(&link->list);
121 sk_psock_free_link(link);
122 }
123 }
124 spin_unlock_bh(&psock->link_lock);
125 if (strp_stop) {
126 write_lock_bh(&sk->sk_callback_lock);
127 sk_psock_stop_strp(sk, psock);
128 write_unlock_bh(&sk->sk_callback_lock);
129 }
130}
131
132static void sock_map_unref(struct sock *sk, void *link_raw)
133{
134 struct sk_psock *psock = sk_psock(sk);
135
136 if (likely(psock)) {
137 sock_map_del_link(sk, psock, link_raw);
138 sk_psock_put(sk, psock);
139 }
140}
141
142static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
143 struct sock *sk)
144{
145 struct bpf_prog *msg_parser, *skb_parser, *skb_verdict;
146 bool skb_progs, sk_psock_is_new = false;
147 struct sk_psock *psock;
148 int ret;
149
150 skb_verdict = READ_ONCE(progs->skb_verdict);
151 skb_parser = READ_ONCE(progs->skb_parser);
152 skb_progs = skb_parser && skb_verdict;
153 if (skb_progs) {
154 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
155 if (IS_ERR(skb_verdict))
156 return PTR_ERR(skb_verdict);
157 skb_parser = bpf_prog_inc_not_zero(skb_parser);
158 if (IS_ERR(skb_parser)) {
159 bpf_prog_put(skb_verdict);
160 return PTR_ERR(skb_parser);
161 }
162 }
163
164 msg_parser = READ_ONCE(progs->msg_parser);
165 if (msg_parser) {
166 msg_parser = bpf_prog_inc_not_zero(msg_parser);
167 if (IS_ERR(msg_parser)) {
168 ret = PTR_ERR(msg_parser);
169 goto out;
170 }
171 }
172
173 psock = sk_psock_get_checked(sk);
174 if (IS_ERR(psock)) {
175 ret = PTR_ERR(psock);
176 goto out_progs;
177 }
178
179 if (psock) {
180 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
181 (skb_progs && READ_ONCE(psock->progs.skb_parser))) {
182 sk_psock_put(sk, psock);
183 ret = -EBUSY;
184 goto out_progs;
185 }
186 } else {
187 psock = sk_psock_init(sk, map->numa_node);
188 if (!psock) {
189 ret = -ENOMEM;
190 goto out_progs;
191 }
192 sk_psock_is_new = true;
193 }
194
195 if (msg_parser)
196 psock_set_prog(&psock->progs.msg_parser, msg_parser);
197 if (sk_psock_is_new) {
198 ret = tcp_bpf_init(sk);
199 if (ret < 0)
200 goto out_drop;
201 } else {
202 tcp_bpf_reinit(sk);
203 }
204
205 write_lock_bh(&sk->sk_callback_lock);
206 if (skb_progs && !psock->parser.enabled) {
207 ret = sk_psock_init_strp(sk, psock);
208 if (ret) {
209 write_unlock_bh(&sk->sk_callback_lock);
210 goto out_drop;
211 }
212 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
213 psock_set_prog(&psock->progs.skb_parser, skb_parser);
214 sk_psock_start_strp(sk, psock);
215 }
216 write_unlock_bh(&sk->sk_callback_lock);
217 return 0;
218out_drop:
219 sk_psock_put(sk, psock);
220out_progs:
221 if (msg_parser)
222 bpf_prog_put(msg_parser);
223out:
224 if (skb_progs) {
225 bpf_prog_put(skb_verdict);
226 bpf_prog_put(skb_parser);
227 }
228 return ret;
229}
230
231static void sock_map_free(struct bpf_map *map)
232{
233 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
234 int i;
235
236 synchronize_rcu();
237 rcu_read_lock();
238 raw_spin_lock_bh(&stab->lock);
239 for (i = 0; i < stab->map.max_entries; i++) {
240 struct sock **psk = &stab->sks[i];
241 struct sock *sk;
242
243 sk = xchg(psk, NULL);
244 if (sk)
245 sock_map_unref(sk, psk);
246 }
247 raw_spin_unlock_bh(&stab->lock);
248 rcu_read_unlock();
249
250 synchronize_rcu();
251
252 bpf_map_area_free(stab->sks);
253 kfree(stab);
254}
255
256static void sock_map_release_progs(struct bpf_map *map)
257{
258 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
259}
260
261static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
262{
263 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
264
265 WARN_ON_ONCE(!rcu_read_lock_held());
266
267 if (unlikely(key >= map->max_entries))
268 return NULL;
269 return READ_ONCE(stab->sks[key]);
270}
271
272static void *sock_map_lookup(struct bpf_map *map, void *key)
273{
274 return ERR_PTR(-EOPNOTSUPP);
275}
276
277static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
278 struct sock **psk)
279{
280 struct sock *sk;
281 int err = 0;
282
283 raw_spin_lock_bh(&stab->lock);
284 sk = *psk;
285 if (!sk_test || sk_test == sk)
286 sk = xchg(psk, NULL);
287
288 if (likely(sk))
289 sock_map_unref(sk, psk);
290 else
291 err = -EINVAL;
292
293 raw_spin_unlock_bh(&stab->lock);
294 return err;
295}
296
297static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
298 void *link_raw)
299{
300 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
301
302 __sock_map_delete(stab, sk, link_raw);
303}
304
305static int sock_map_delete_elem(struct bpf_map *map, void *key)
306{
307 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
308 u32 i = *(u32 *)key;
309 struct sock **psk;
310
311 if (unlikely(i >= map->max_entries))
312 return -EINVAL;
313
314 psk = &stab->sks[i];
315 return __sock_map_delete(stab, NULL, psk);
316}
317
318static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
319{
320 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
321 u32 i = key ? *(u32 *)key : U32_MAX;
322 u32 *key_next = next;
323
324 if (i == stab->map.max_entries - 1)
325 return -ENOENT;
326 if (i >= stab->map.max_entries)
327 *key_next = 0;
328 else
329 *key_next = i + 1;
330 return 0;
331}
332
333static int sock_map_update_common(struct bpf_map *map, u32 idx,
334 struct sock *sk, u64 flags)
335{
336 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
337 struct inet_connection_sock *icsk = inet_csk(sk);
338 struct sk_psock_link *link;
339 struct sk_psock *psock;
340 struct sock *osk;
341 int ret;
342
343 WARN_ON_ONCE(!rcu_read_lock_held());
344 if (unlikely(flags > BPF_EXIST))
345 return -EINVAL;
346 if (unlikely(idx >= map->max_entries))
347 return -E2BIG;
348 if (unlikely(rcu_access_pointer(icsk->icsk_ulp_data)))
349 return -EINVAL;
350
351 link = sk_psock_init_link();
352 if (!link)
353 return -ENOMEM;
354
355 ret = sock_map_link(map, &stab->progs, sk);
356 if (ret < 0)
357 goto out_free;
358
359 psock = sk_psock(sk);
360 WARN_ON_ONCE(!psock);
361
362 raw_spin_lock_bh(&stab->lock);
363 osk = stab->sks[idx];
364 if (osk && flags == BPF_NOEXIST) {
365 ret = -EEXIST;
366 goto out_unlock;
367 } else if (!osk && flags == BPF_EXIST) {
368 ret = -ENOENT;
369 goto out_unlock;
370 }
371
372 sock_map_add_link(psock, link, map, &stab->sks[idx]);
373 stab->sks[idx] = sk;
374 if (osk)
375 sock_map_unref(osk, &stab->sks[idx]);
376 raw_spin_unlock_bh(&stab->lock);
377 return 0;
378out_unlock:
379 raw_spin_unlock_bh(&stab->lock);
380 if (psock)
381 sk_psock_put(sk, psock);
382out_free:
383 sk_psock_free_link(link);
384 return ret;
385}
386
387static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
388{
389 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
390 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB;
391}
392
393static bool sock_map_sk_is_suitable(const struct sock *sk)
394{
395 return sk->sk_type == SOCK_STREAM &&
396 sk->sk_protocol == IPPROTO_TCP;
397}
398
399static int sock_map_update_elem(struct bpf_map *map, void *key,
400 void *value, u64 flags)
401{
402 u32 ufd = *(u32 *)value;
403 u32 idx = *(u32 *)key;
404 struct socket *sock;
405 struct sock *sk;
406 int ret;
407
408 sock = sockfd_lookup(ufd, &ret);
409 if (!sock)
410 return ret;
411 sk = sock->sk;
412 if (!sk) {
413 ret = -EINVAL;
414 goto out;
415 }
416 if (!sock_map_sk_is_suitable(sk) ||
417 sk->sk_state != TCP_ESTABLISHED) {
418 ret = -EOPNOTSUPP;
419 goto out;
420 }
421
422 sock_map_sk_acquire(sk);
423 ret = sock_map_update_common(map, idx, sk, flags);
424 sock_map_sk_release(sk);
425out:
426 fput(sock->file);
427 return ret;
428}
429
430BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
431 struct bpf_map *, map, void *, key, u64, flags)
432{
433 WARN_ON_ONCE(!rcu_read_lock_held());
434
435 if (likely(sock_map_sk_is_suitable(sops->sk) &&
436 sock_map_op_okay(sops)))
437 return sock_map_update_common(map, *(u32 *)key, sops->sk,
438 flags);
439 return -EOPNOTSUPP;
440}
441
442const struct bpf_func_proto bpf_sock_map_update_proto = {
443 .func = bpf_sock_map_update,
444 .gpl_only = false,
445 .pkt_access = true,
446 .ret_type = RET_INTEGER,
447 .arg1_type = ARG_PTR_TO_CTX,
448 .arg2_type = ARG_CONST_MAP_PTR,
449 .arg3_type = ARG_PTR_TO_MAP_KEY,
450 .arg4_type = ARG_ANYTHING,
451};
452
453BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
454 struct bpf_map *, map, u32, key, u64, flags)
455{
456 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
457
458 if (unlikely(flags & ~(BPF_F_INGRESS)))
459 return SK_DROP;
460 tcb->bpf.flags = flags;
461 tcb->bpf.sk_redir = __sock_map_lookup_elem(map, key);
462 if (!tcb->bpf.sk_redir)
463 return SK_DROP;
464 return SK_PASS;
465}
466
467const struct bpf_func_proto bpf_sk_redirect_map_proto = {
468 .func = bpf_sk_redirect_map,
469 .gpl_only = false,
470 .ret_type = RET_INTEGER,
471 .arg1_type = ARG_PTR_TO_CTX,
472 .arg2_type = ARG_CONST_MAP_PTR,
473 .arg3_type = ARG_ANYTHING,
474 .arg4_type = ARG_ANYTHING,
475};
476
477BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
478 struct bpf_map *, map, u32, key, u64, flags)
479{
480 if (unlikely(flags & ~(BPF_F_INGRESS)))
481 return SK_DROP;
482 msg->flags = flags;
483 msg->sk_redir = __sock_map_lookup_elem(map, key);
484 if (!msg->sk_redir)
485 return SK_DROP;
486 return SK_PASS;
487}
488
489const struct bpf_func_proto bpf_msg_redirect_map_proto = {
490 .func = bpf_msg_redirect_map,
491 .gpl_only = false,
492 .ret_type = RET_INTEGER,
493 .arg1_type = ARG_PTR_TO_CTX,
494 .arg2_type = ARG_CONST_MAP_PTR,
495 .arg3_type = ARG_ANYTHING,
496 .arg4_type = ARG_ANYTHING,
497};
498
499const struct bpf_map_ops sock_map_ops = {
500 .map_alloc = sock_map_alloc,
501 .map_free = sock_map_free,
502 .map_get_next_key = sock_map_get_next_key,
503 .map_update_elem = sock_map_update_elem,
504 .map_delete_elem = sock_map_delete_elem,
505 .map_lookup_elem = sock_map_lookup,
506 .map_release_uref = sock_map_release_progs,
507 .map_check_btf = map_check_no_btf,
508};
509
510struct bpf_htab_elem {
511 struct rcu_head rcu;
512 u32 hash;
513 struct sock *sk;
514 struct hlist_node node;
515 u8 key[0];
516};
517
518struct bpf_htab_bucket {
519 struct hlist_head head;
520 raw_spinlock_t lock;
521};
522
523struct bpf_htab {
524 struct bpf_map map;
525 struct bpf_htab_bucket *buckets;
526 u32 buckets_num;
527 u32 elem_size;
528 struct sk_psock_progs progs;
529 atomic_t count;
530};
531
532static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
533{
534 return jhash(key, len, 0);
535}
536
537static struct bpf_htab_bucket *sock_hash_select_bucket(struct bpf_htab *htab,
538 u32 hash)
539{
540 return &htab->buckets[hash & (htab->buckets_num - 1)];
541}
542
543static struct bpf_htab_elem *
544sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
545 u32 key_size)
546{
547 struct bpf_htab_elem *elem;
548
549 hlist_for_each_entry_rcu(elem, head, node) {
550 if (elem->hash == hash &&
551 !memcmp(&elem->key, key, key_size))
552 return elem;
553 }
554
555 return NULL;
556}
557
558static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
559{
560 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
561 u32 key_size = map->key_size, hash;
562 struct bpf_htab_bucket *bucket;
563 struct bpf_htab_elem *elem;
564
565 WARN_ON_ONCE(!rcu_read_lock_held());
566
567 hash = sock_hash_bucket_hash(key, key_size);
568 bucket = sock_hash_select_bucket(htab, hash);
569 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
570
571 return elem ? elem->sk : NULL;
572}
573
574static void sock_hash_free_elem(struct bpf_htab *htab,
575 struct bpf_htab_elem *elem)
576{
577 atomic_dec(&htab->count);
578 kfree_rcu(elem, rcu);
579}
580
581static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
582 void *link_raw)
583{
584 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
585 struct bpf_htab_elem *elem_probe, *elem = link_raw;
586 struct bpf_htab_bucket *bucket;
587
588 WARN_ON_ONCE(!rcu_read_lock_held());
589 bucket = sock_hash_select_bucket(htab, elem->hash);
590
591 /* elem may be deleted in parallel from the map, but access here
592 * is okay since it's going away only after RCU grace period.
593 * However, we need to check whether it's still present.
594 */
595 raw_spin_lock_bh(&bucket->lock);
596 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
597 elem->key, map->key_size);
598 if (elem_probe && elem_probe == elem) {
599 hlist_del_rcu(&elem->node);
600 sock_map_unref(elem->sk, elem);
601 sock_hash_free_elem(htab, elem);
602 }
603 raw_spin_unlock_bh(&bucket->lock);
604}
605
606static int sock_hash_delete_elem(struct bpf_map *map, void *key)
607{
608 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
609 u32 hash, key_size = map->key_size;
610 struct bpf_htab_bucket *bucket;
611 struct bpf_htab_elem *elem;
612 int ret = -ENOENT;
613
614 hash = sock_hash_bucket_hash(key, key_size);
615 bucket = sock_hash_select_bucket(htab, hash);
616
617 raw_spin_lock_bh(&bucket->lock);
618 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
619 if (elem) {
620 hlist_del_rcu(&elem->node);
621 sock_map_unref(elem->sk, elem);
622 sock_hash_free_elem(htab, elem);
623 ret = 0;
624 }
625 raw_spin_unlock_bh(&bucket->lock);
626 return ret;
627}
628
629static struct bpf_htab_elem *sock_hash_alloc_elem(struct bpf_htab *htab,
630 void *key, u32 key_size,
631 u32 hash, struct sock *sk,
632 struct bpf_htab_elem *old)
633{
634 struct bpf_htab_elem *new;
635
636 if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
637 if (!old) {
638 atomic_dec(&htab->count);
639 return ERR_PTR(-E2BIG);
640 }
641 }
642
643 new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
644 htab->map.numa_node);
645 if (!new) {
646 atomic_dec(&htab->count);
647 return ERR_PTR(-ENOMEM);
648 }
649 memcpy(new->key, key, key_size);
650 new->sk = sk;
651 new->hash = hash;
652 return new;
653}
654
655static int sock_hash_update_common(struct bpf_map *map, void *key,
656 struct sock *sk, u64 flags)
657{
658 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
659 struct inet_connection_sock *icsk = inet_csk(sk);
660 u32 key_size = map->key_size, hash;
661 struct bpf_htab_elem *elem, *elem_new;
662 struct bpf_htab_bucket *bucket;
663 struct sk_psock_link *link;
664 struct sk_psock *psock;
665 int ret;
666
667 WARN_ON_ONCE(!rcu_read_lock_held());
668 if (unlikely(flags > BPF_EXIST))
669 return -EINVAL;
670 if (unlikely(icsk->icsk_ulp_data))
671 return -EINVAL;
672
673 link = sk_psock_init_link();
674 if (!link)
675 return -ENOMEM;
676
677 ret = sock_map_link(map, &htab->progs, sk);
678 if (ret < 0)
679 goto out_free;
680
681 psock = sk_psock(sk);
682 WARN_ON_ONCE(!psock);
683
684 hash = sock_hash_bucket_hash(key, key_size);
685 bucket = sock_hash_select_bucket(htab, hash);
686
687 raw_spin_lock_bh(&bucket->lock);
688 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
689 if (elem && flags == BPF_NOEXIST) {
690 ret = -EEXIST;
691 goto out_unlock;
692 } else if (!elem && flags == BPF_EXIST) {
693 ret = -ENOENT;
694 goto out_unlock;
695 }
696
697 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
698 if (IS_ERR(elem_new)) {
699 ret = PTR_ERR(elem_new);
700 goto out_unlock;
701 }
702
703 sock_map_add_link(psock, link, map, elem_new);
704 /* Add new element to the head of the list, so that
705 * concurrent search will find it before old elem.
706 */
707 hlist_add_head_rcu(&elem_new->node, &bucket->head);
708 if (elem) {
709 hlist_del_rcu(&elem->node);
710 sock_map_unref(elem->sk, elem);
711 sock_hash_free_elem(htab, elem);
712 }
713 raw_spin_unlock_bh(&bucket->lock);
714 return 0;
715out_unlock:
716 raw_spin_unlock_bh(&bucket->lock);
717 sk_psock_put(sk, psock);
718out_free:
719 sk_psock_free_link(link);
720 return ret;
721}
722
723static int sock_hash_update_elem(struct bpf_map *map, void *key,
724 void *value, u64 flags)
725{
726 u32 ufd = *(u32 *)value;
727 struct socket *sock;
728 struct sock *sk;
729 int ret;
730
731 sock = sockfd_lookup(ufd, &ret);
732 if (!sock)
733 return ret;
734 sk = sock->sk;
735 if (!sk) {
736 ret = -EINVAL;
737 goto out;
738 }
739 if (!sock_map_sk_is_suitable(sk) ||
740 sk->sk_state != TCP_ESTABLISHED) {
741 ret = -EOPNOTSUPP;
742 goto out;
743 }
744
745 sock_map_sk_acquire(sk);
746 ret = sock_hash_update_common(map, key, sk, flags);
747 sock_map_sk_release(sk);
748out:
749 fput(sock->file);
750 return ret;
751}
752
753static int sock_hash_get_next_key(struct bpf_map *map, void *key,
754 void *key_next)
755{
756 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
757 struct bpf_htab_elem *elem, *elem_next;
758 u32 hash, key_size = map->key_size;
759 struct hlist_head *head;
760 int i = 0;
761
762 if (!key)
763 goto find_first_elem;
764 hash = sock_hash_bucket_hash(key, key_size);
765 head = &sock_hash_select_bucket(htab, hash)->head;
766 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
767 if (!elem)
768 goto find_first_elem;
769
770 elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&elem->node)),
771 struct bpf_htab_elem, node);
772 if (elem_next) {
773 memcpy(key_next, elem_next->key, key_size);
774 return 0;
775 }
776
777 i = hash & (htab->buckets_num - 1);
778 i++;
779find_first_elem:
780 for (; i < htab->buckets_num; i++) {
781 head = &sock_hash_select_bucket(htab, i)->head;
782 elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
783 struct bpf_htab_elem, node);
784 if (elem_next) {
785 memcpy(key_next, elem_next->key, key_size);
786 return 0;
787 }
788 }
789
790 return -ENOENT;
791}
792
793static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
794{
795 struct bpf_htab *htab;
796 int i, err;
797 u64 cost;
798
799 if (!capable(CAP_NET_ADMIN))
800 return ERR_PTR(-EPERM);
801 if (attr->max_entries == 0 ||
802 attr->key_size == 0 ||
803 attr->value_size != 4 ||
804 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
805 return ERR_PTR(-EINVAL);
806 if (attr->key_size > MAX_BPF_STACK)
807 return ERR_PTR(-E2BIG);
808
809 htab = kzalloc(sizeof(*htab), GFP_USER);
810 if (!htab)
811 return ERR_PTR(-ENOMEM);
812
813 bpf_map_init_from_attr(&htab->map, attr);
814
815 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
816 htab->elem_size = sizeof(struct bpf_htab_elem) +
817 round_up(htab->map.key_size, 8);
818 if (htab->buckets_num == 0 ||
819 htab->buckets_num > U32_MAX / sizeof(struct bpf_htab_bucket)) {
820 err = -EINVAL;
821 goto free_htab;
822 }
823
824 cost = (u64) htab->buckets_num * sizeof(struct bpf_htab_bucket) +
825 (u64) htab->elem_size * htab->map.max_entries;
826 if (cost >= U32_MAX - PAGE_SIZE) {
827 err = -EINVAL;
828 goto free_htab;
829 }
830
831 htab->buckets = bpf_map_area_alloc(htab->buckets_num *
832 sizeof(struct bpf_htab_bucket),
833 htab->map.numa_node);
834 if (!htab->buckets) {
835 err = -ENOMEM;
836 goto free_htab;
837 }
838
839 for (i = 0; i < htab->buckets_num; i++) {
840 INIT_HLIST_HEAD(&htab->buckets[i].head);
841 raw_spin_lock_init(&htab->buckets[i].lock);
842 }
843
844 return &htab->map;
845free_htab:
846 kfree(htab);
847 return ERR_PTR(err);
848}
849
850static void sock_hash_free(struct bpf_map *map)
851{
852 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
853 struct bpf_htab_bucket *bucket;
854 struct bpf_htab_elem *elem;
855 struct hlist_node *node;
856 int i;
857
858 synchronize_rcu();
859 rcu_read_lock();
860 for (i = 0; i < htab->buckets_num; i++) {
861 bucket = sock_hash_select_bucket(htab, i);
862 raw_spin_lock_bh(&bucket->lock);
863 hlist_for_each_entry_safe(elem, node, &bucket->head, node) {
864 hlist_del_rcu(&elem->node);
865 sock_map_unref(elem->sk, elem);
866 }
867 raw_spin_unlock_bh(&bucket->lock);
868 }
869 rcu_read_unlock();
870
871 bpf_map_area_free(htab->buckets);
872 kfree(htab);
873}
874
875static void sock_hash_release_progs(struct bpf_map *map)
876{
877 psock_progs_drop(&container_of(map, struct bpf_htab, map)->progs);
878}
879
880BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
881 struct bpf_map *, map, void *, key, u64, flags)
882{
883 WARN_ON_ONCE(!rcu_read_lock_held());
884
885 if (likely(sock_map_sk_is_suitable(sops->sk) &&
886 sock_map_op_okay(sops)))
887 return sock_hash_update_common(map, key, sops->sk, flags);
888 return -EOPNOTSUPP;
889}
890
891const struct bpf_func_proto bpf_sock_hash_update_proto = {
892 .func = bpf_sock_hash_update,
893 .gpl_only = false,
894 .pkt_access = true,
895 .ret_type = RET_INTEGER,
896 .arg1_type = ARG_PTR_TO_CTX,
897 .arg2_type = ARG_CONST_MAP_PTR,
898 .arg3_type = ARG_PTR_TO_MAP_KEY,
899 .arg4_type = ARG_ANYTHING,
900};
901
902BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
903 struct bpf_map *, map, void *, key, u64, flags)
904{
905 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
906
907 if (unlikely(flags & ~(BPF_F_INGRESS)))
908 return SK_DROP;
909 tcb->bpf.flags = flags;
910 tcb->bpf.sk_redir = __sock_hash_lookup_elem(map, key);
911 if (!tcb->bpf.sk_redir)
912 return SK_DROP;
913 return SK_PASS;
914}
915
916const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
917 .func = bpf_sk_redirect_hash,
918 .gpl_only = false,
919 .ret_type = RET_INTEGER,
920 .arg1_type = ARG_PTR_TO_CTX,
921 .arg2_type = ARG_CONST_MAP_PTR,
922 .arg3_type = ARG_PTR_TO_MAP_KEY,
923 .arg4_type = ARG_ANYTHING,
924};
925
926BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
927 struct bpf_map *, map, void *, key, u64, flags)
928{
929 if (unlikely(flags & ~(BPF_F_INGRESS)))
930 return SK_DROP;
931 msg->flags = flags;
932 msg->sk_redir = __sock_hash_lookup_elem(map, key);
933 if (!msg->sk_redir)
934 return SK_DROP;
935 return SK_PASS;
936}
937
938const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
939 .func = bpf_msg_redirect_hash,
940 .gpl_only = false,
941 .ret_type = RET_INTEGER,
942 .arg1_type = ARG_PTR_TO_CTX,
943 .arg2_type = ARG_CONST_MAP_PTR,
944 .arg3_type = ARG_PTR_TO_MAP_KEY,
945 .arg4_type = ARG_ANYTHING,
946};
947
948const struct bpf_map_ops sock_hash_ops = {
949 .map_alloc = sock_hash_alloc,
950 .map_free = sock_hash_free,
951 .map_get_next_key = sock_hash_get_next_key,
952 .map_update_elem = sock_hash_update_elem,
953 .map_delete_elem = sock_hash_delete_elem,
954 .map_lookup_elem = sock_map_lookup,
955 .map_release_uref = sock_hash_release_progs,
956 .map_check_btf = map_check_no_btf,
957};
958
959static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
960{
961 switch (map->map_type) {
962 case BPF_MAP_TYPE_SOCKMAP:
963 return &container_of(map, struct bpf_stab, map)->progs;
964 case BPF_MAP_TYPE_SOCKHASH:
965 return &container_of(map, struct bpf_htab, map)->progs;
966 default:
967 break;
968 }
969
970 return NULL;
971}
972
973int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
974 u32 which)
975{
976 struct sk_psock_progs *progs = sock_map_progs(map);
977
978 if (!progs)
979 return -EOPNOTSUPP;
980
981 switch (which) {
982 case BPF_SK_MSG_VERDICT:
983 psock_set_prog(&progs->msg_parser, prog);
984 break;
985 case BPF_SK_SKB_STREAM_PARSER:
986 psock_set_prog(&progs->skb_parser, prog);
987 break;
988 case BPF_SK_SKB_STREAM_VERDICT:
989 psock_set_prog(&progs->skb_verdict, prog);
990 break;
991 default:
992 return -EOPNOTSUPP;
993 }
994
995 return 0;
996}
997
998void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link)
999{
1000 switch (link->map->map_type) {
1001 case BPF_MAP_TYPE_SOCKMAP:
1002 return sock_map_delete_from_link(link->map, sk,
1003 link->link_raw);
1004 case BPF_MAP_TYPE_SOCKHASH:
1005 return sock_hash_delete_from_link(link->map, sk,
1006 link->link_raw);
1007 default:
1008 break;
1009 }
1010}