1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
3
4 #include <linux/bpf.h>
5 #include <linux/btf_ids.h>
6 #include <linux/filter.h>
7 #include <linux/errno.h>
8 #include <linux/file.h>
9 #include <linux/net.h>
10 #include <linux/workqueue.h>
11 #include <linux/skmsg.h>
12 #include <linux/list.h>
13 #include <linux/jhash.h>
14 #include <linux/sock_diag.h>
15 #include <net/udp.h>
16
17 struct bpf_stab {
18 struct bpf_map map;
19 struct sock **sks;
20 struct sk_psock_progs progs;
21 raw_spinlock_t lock;
22 };
23
24 #define SOCK_CREATE_FLAG_MASK \
25 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
26
sock_map_alloc(union bpf_attr * attr)27 static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
28 {
29 struct bpf_stab *stab;
30 u64 cost;
31 int err;
32
33 if (!capable(CAP_NET_ADMIN))
34 return ERR_PTR(-EPERM);
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 = kzalloc(sizeof(*stab), GFP_USER);
43 if (!stab)
44 return ERR_PTR(-ENOMEM);
45
46 bpf_map_init_from_attr(&stab->map, attr);
47 raw_spin_lock_init(&stab->lock);
48
49 /* Make sure page count doesn't overflow. */
50 cost = (u64) stab->map.max_entries * sizeof(struct sock *);
51 err = bpf_map_charge_init(&stab->map.memory, cost);
52 if (err)
53 goto free_stab;
54
55 stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries *
56 sizeof(struct sock *),
57 stab->map.numa_node);
58 if (stab->sks)
59 return &stab->map;
60 err = -ENOMEM;
61 bpf_map_charge_finish(&stab->map.memory);
62 free_stab:
63 kfree(stab);
64 return ERR_PTR(err);
65 }
66
sock_map_get_from_fd(const union bpf_attr * attr,struct bpf_prog * prog)67 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
68 {
69 u32 ufd = attr->target_fd;
70 struct bpf_map *map;
71 struct fd f;
72 int ret;
73
74 if (attr->attach_flags || attr->replace_bpf_fd)
75 return -EINVAL;
76
77 f = fdget(ufd);
78 map = __bpf_map_get(f);
79 if (IS_ERR(map))
80 return PTR_ERR(map);
81 ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
82 fdput(f);
83 return ret;
84 }
85
sock_map_prog_detach(const union bpf_attr * attr,enum bpf_prog_type ptype)86 int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
87 {
88 u32 ufd = attr->target_fd;
89 struct bpf_prog *prog;
90 struct bpf_map *map;
91 struct fd f;
92 int ret;
93
94 if (attr->attach_flags || attr->replace_bpf_fd)
95 return -EINVAL;
96
97 f = fdget(ufd);
98 map = __bpf_map_get(f);
99 if (IS_ERR(map))
100 return PTR_ERR(map);
101
102 prog = bpf_prog_get(attr->attach_bpf_fd);
103 if (IS_ERR(prog)) {
104 ret = PTR_ERR(prog);
105 goto put_map;
106 }
107
108 if (prog->type != ptype) {
109 ret = -EINVAL;
110 goto put_prog;
111 }
112
113 ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
114 put_prog:
115 bpf_prog_put(prog);
116 put_map:
117 fdput(f);
118 return ret;
119 }
120
sock_map_sk_acquire(struct sock * sk)121 static void sock_map_sk_acquire(struct sock *sk)
122 __acquires(&sk->sk_lock.slock)
123 {
124 lock_sock(sk);
125 preempt_disable();
126 rcu_read_lock();
127 }
128
sock_map_sk_release(struct sock * sk)129 static void sock_map_sk_release(struct sock *sk)
130 __releases(&sk->sk_lock.slock)
131 {
132 rcu_read_unlock();
133 preempt_enable();
134 release_sock(sk);
135 }
136
sock_map_add_link(struct sk_psock * psock,struct sk_psock_link * link,struct bpf_map * map,void * link_raw)137 static void sock_map_add_link(struct sk_psock *psock,
138 struct sk_psock_link *link,
139 struct bpf_map *map, void *link_raw)
140 {
141 link->link_raw = link_raw;
142 link->map = map;
143 spin_lock_bh(&psock->link_lock);
144 list_add_tail(&link->list, &psock->link);
145 spin_unlock_bh(&psock->link_lock);
146 }
147
sock_map_del_link(struct sock * sk,struct sk_psock * psock,void * link_raw)148 static void sock_map_del_link(struct sock *sk,
149 struct sk_psock *psock, void *link_raw)
150 {
151 bool strp_stop = false, verdict_stop = false;
152 struct sk_psock_link *link, *tmp;
153
154 spin_lock_bh(&psock->link_lock);
155 list_for_each_entry_safe(link, tmp, &psock->link, list) {
156 if (link->link_raw == link_raw) {
157 struct bpf_map *map = link->map;
158 struct bpf_stab *stab = container_of(map, struct bpf_stab,
159 map);
160 if (psock->parser.enabled && stab->progs.skb_parser)
161 strp_stop = true;
162 if (psock->parser.enabled && stab->progs.skb_verdict)
163 verdict_stop = true;
164 list_del(&link->list);
165 sk_psock_free_link(link);
166 }
167 }
168 spin_unlock_bh(&psock->link_lock);
169 if (strp_stop || verdict_stop) {
170 write_lock_bh(&sk->sk_callback_lock);
171 if (strp_stop)
172 sk_psock_stop_strp(sk, psock);
173 else
174 sk_psock_stop_verdict(sk, psock);
175 write_unlock_bh(&sk->sk_callback_lock);
176 }
177 }
178
sock_map_unref(struct sock * sk,void * link_raw)179 static 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
sock_map_init_proto(struct sock * sk,struct sk_psock * psock)189 static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
190 {
191 struct proto *prot;
192
193 switch (sk->sk_type) {
194 case SOCK_STREAM:
195 prot = tcp_bpf_get_proto(sk, psock);
196 break;
197
198 case SOCK_DGRAM:
199 prot = udp_bpf_get_proto(sk, psock);
200 break;
201
202 default:
203 return -EINVAL;
204 }
205
206 if (IS_ERR(prot))
207 return PTR_ERR(prot);
208
209 sk_psock_update_proto(sk, psock, prot);
210 return 0;
211 }
212
sock_map_psock_get_checked(struct sock * sk)213 static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
214 {
215 struct sk_psock *psock;
216
217 rcu_read_lock();
218 psock = sk_psock(sk);
219 if (psock) {
220 if (sk->sk_prot->close != sock_map_close) {
221 psock = ERR_PTR(-EBUSY);
222 goto out;
223 }
224
225 if (!refcount_inc_not_zero(&psock->refcnt))
226 psock = ERR_PTR(-EBUSY);
227 }
228 out:
229 rcu_read_unlock();
230 return psock;
231 }
232
sock_map_link(struct bpf_map * map,struct sk_psock_progs * progs,struct sock * sk)233 static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
234 struct sock *sk)
235 {
236 struct bpf_prog *msg_parser, *skb_parser, *skb_verdict;
237 struct sk_psock *psock;
238 int ret;
239
240 skb_verdict = READ_ONCE(progs->skb_verdict);
241 if (skb_verdict) {
242 skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
243 if (IS_ERR(skb_verdict))
244 return PTR_ERR(skb_verdict);
245 }
246
247 skb_parser = READ_ONCE(progs->skb_parser);
248 if (skb_parser) {
249 skb_parser = bpf_prog_inc_not_zero(skb_parser);
250 if (IS_ERR(skb_parser)) {
251 ret = PTR_ERR(skb_parser);
252 goto out_put_skb_verdict;
253 }
254 }
255
256 msg_parser = READ_ONCE(progs->msg_parser);
257 if (msg_parser) {
258 msg_parser = bpf_prog_inc_not_zero(msg_parser);
259 if (IS_ERR(msg_parser)) {
260 ret = PTR_ERR(msg_parser);
261 goto out_put_skb_parser;
262 }
263 }
264
265 psock = sock_map_psock_get_checked(sk);
266 if (IS_ERR(psock)) {
267 ret = PTR_ERR(psock);
268 goto out_progs;
269 }
270
271 if (psock) {
272 if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
273 (skb_parser && READ_ONCE(psock->progs.skb_parser)) ||
274 (skb_verdict && READ_ONCE(psock->progs.skb_verdict))) {
275 sk_psock_put(sk, psock);
276 ret = -EBUSY;
277 goto out_progs;
278 }
279 } else {
280 psock = sk_psock_init(sk, map->numa_node);
281 if (IS_ERR(psock)) {
282 ret = PTR_ERR(psock);
283 goto out_progs;
284 }
285 }
286
287 if (msg_parser)
288 psock_set_prog(&psock->progs.msg_parser, msg_parser);
289
290 ret = sock_map_init_proto(sk, psock);
291 if (ret < 0)
292 goto out_drop;
293
294 write_lock_bh(&sk->sk_callback_lock);
295 if (skb_parser && skb_verdict && !psock->parser.enabled) {
296 ret = sk_psock_init_strp(sk, psock);
297 if (ret)
298 goto out_unlock_drop;
299 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
300 psock_set_prog(&psock->progs.skb_parser, skb_parser);
301 sk_psock_start_strp(sk, psock);
302 } else if (!skb_parser && skb_verdict && !psock->parser.enabled) {
303 psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
304 sk_psock_start_verdict(sk,psock);
305 }
306 write_unlock_bh(&sk->sk_callback_lock);
307 return 0;
308 out_unlock_drop:
309 write_unlock_bh(&sk->sk_callback_lock);
310 out_drop:
311 sk_psock_put(sk, psock);
312 out_progs:
313 if (msg_parser)
314 bpf_prog_put(msg_parser);
315 out_put_skb_parser:
316 if (skb_parser)
317 bpf_prog_put(skb_parser);
318 out_put_skb_verdict:
319 if (skb_verdict)
320 bpf_prog_put(skb_verdict);
321 return ret;
322 }
323
sock_map_link_no_progs(struct bpf_map * map,struct sock * sk)324 static int sock_map_link_no_progs(struct bpf_map *map, struct sock *sk)
325 {
326 struct sk_psock *psock;
327 int ret;
328
329 psock = sock_map_psock_get_checked(sk);
330 if (IS_ERR(psock))
331 return PTR_ERR(psock);
332
333 if (!psock) {
334 psock = sk_psock_init(sk, map->numa_node);
335 if (IS_ERR(psock))
336 return PTR_ERR(psock);
337 }
338
339 ret = sock_map_init_proto(sk, psock);
340 if (ret < 0)
341 sk_psock_put(sk, psock);
342 return ret;
343 }
344
sock_map_free(struct bpf_map * map)345 static void sock_map_free(struct bpf_map *map)
346 {
347 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
348 int i;
349
350 /* After the sync no updates or deletes will be in-flight so it
351 * is safe to walk map and remove entries without risking a race
352 * in EEXIST update case.
353 */
354 synchronize_rcu();
355 for (i = 0; i < stab->map.max_entries; i++) {
356 struct sock **psk = &stab->sks[i];
357 struct sock *sk;
358
359 sk = xchg(psk, NULL);
360 if (sk) {
361 lock_sock(sk);
362 rcu_read_lock();
363 sock_map_unref(sk, psk);
364 rcu_read_unlock();
365 release_sock(sk);
366 }
367 }
368
369 /* wait for psock readers accessing its map link */
370 synchronize_rcu();
371
372 bpf_map_area_free(stab->sks);
373 kfree(stab);
374 }
375
sock_map_release_progs(struct bpf_map * map)376 static void sock_map_release_progs(struct bpf_map *map)
377 {
378 psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
379 }
380
__sock_map_lookup_elem(struct bpf_map * map,u32 key)381 static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
382 {
383 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
384
385 WARN_ON_ONCE(!rcu_read_lock_held());
386
387 if (unlikely(key >= map->max_entries))
388 return NULL;
389 return READ_ONCE(stab->sks[key]);
390 }
391
sock_map_lookup(struct bpf_map * map,void * key)392 static void *sock_map_lookup(struct bpf_map *map, void *key)
393 {
394 struct sock *sk;
395
396 sk = __sock_map_lookup_elem(map, *(u32 *)key);
397 if (!sk)
398 return NULL;
399 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
400 return NULL;
401 return sk;
402 }
403
sock_map_lookup_sys(struct bpf_map * map,void * key)404 static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
405 {
406 struct sock *sk;
407
408 if (map->value_size != sizeof(u64))
409 return ERR_PTR(-ENOSPC);
410
411 sk = __sock_map_lookup_elem(map, *(u32 *)key);
412 if (!sk)
413 return ERR_PTR(-ENOENT);
414
415 __sock_gen_cookie(sk);
416 return &sk->sk_cookie;
417 }
418
__sock_map_delete(struct bpf_stab * stab,struct sock * sk_test,struct sock ** psk)419 static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
420 struct sock **psk)
421 {
422 struct sock *sk;
423 int err = 0;
424
425 raw_spin_lock_bh(&stab->lock);
426 sk = *psk;
427 if (!sk_test || sk_test == sk)
428 sk = xchg(psk, NULL);
429
430 if (likely(sk))
431 sock_map_unref(sk, psk);
432 else
433 err = -EINVAL;
434
435 raw_spin_unlock_bh(&stab->lock);
436 return err;
437 }
438
sock_map_delete_from_link(struct bpf_map * map,struct sock * sk,void * link_raw)439 static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
440 void *link_raw)
441 {
442 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
443
444 __sock_map_delete(stab, sk, link_raw);
445 }
446
sock_map_delete_elem(struct bpf_map * map,void * key)447 static int sock_map_delete_elem(struct bpf_map *map, void *key)
448 {
449 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
450 u32 i = *(u32 *)key;
451 struct sock **psk;
452
453 if (unlikely(i >= map->max_entries))
454 return -EINVAL;
455
456 psk = &stab->sks[i];
457 return __sock_map_delete(stab, NULL, psk);
458 }
459
sock_map_get_next_key(struct bpf_map * map,void * key,void * next)460 static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
461 {
462 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
463 u32 i = key ? *(u32 *)key : U32_MAX;
464 u32 *key_next = next;
465
466 if (i == stab->map.max_entries - 1)
467 return -ENOENT;
468 if (i >= stab->map.max_entries)
469 *key_next = 0;
470 else
471 *key_next = i + 1;
472 return 0;
473 }
474
475 static bool sock_map_redirect_allowed(const struct sock *sk);
476
sock_map_update_common(struct bpf_map * map,u32 idx,struct sock * sk,u64 flags)477 static int sock_map_update_common(struct bpf_map *map, u32 idx,
478 struct sock *sk, u64 flags)
479 {
480 struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
481 struct sk_psock_link *link;
482 struct sk_psock *psock;
483 struct sock *osk;
484 int ret;
485
486 WARN_ON_ONCE(!rcu_read_lock_held());
487 if (unlikely(flags > BPF_EXIST))
488 return -EINVAL;
489 if (unlikely(idx >= map->max_entries))
490 return -E2BIG;
491
492 link = sk_psock_init_link();
493 if (!link)
494 return -ENOMEM;
495
496 /* Only sockets we can redirect into/from in BPF need to hold
497 * refs to parser/verdict progs and have their sk_data_ready
498 * and sk_write_space callbacks overridden.
499 */
500 if (sock_map_redirect_allowed(sk))
501 ret = sock_map_link(map, &stab->progs, sk);
502 else
503 ret = sock_map_link_no_progs(map, sk);
504 if (ret < 0)
505 goto out_free;
506
507 psock = sk_psock(sk);
508 WARN_ON_ONCE(!psock);
509
510 raw_spin_lock_bh(&stab->lock);
511 osk = stab->sks[idx];
512 if (osk && flags == BPF_NOEXIST) {
513 ret = -EEXIST;
514 goto out_unlock;
515 } else if (!osk && flags == BPF_EXIST) {
516 ret = -ENOENT;
517 goto out_unlock;
518 }
519
520 sock_map_add_link(psock, link, map, &stab->sks[idx]);
521 stab->sks[idx] = sk;
522 if (osk)
523 sock_map_unref(osk, &stab->sks[idx]);
524 raw_spin_unlock_bh(&stab->lock);
525 return 0;
526 out_unlock:
527 raw_spin_unlock_bh(&stab->lock);
528 if (psock)
529 sk_psock_put(sk, psock);
530 out_free:
531 sk_psock_free_link(link);
532 return ret;
533 }
534
sock_map_op_okay(const struct bpf_sock_ops_kern * ops)535 static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
536 {
537 return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
538 ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
539 ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
540 }
541
sk_is_tcp(const struct sock * sk)542 static bool sk_is_tcp(const struct sock *sk)
543 {
544 return sk->sk_type == SOCK_STREAM &&
545 sk->sk_protocol == IPPROTO_TCP;
546 }
547
sk_is_udp(const struct sock * sk)548 static bool sk_is_udp(const struct sock *sk)
549 {
550 return sk->sk_type == SOCK_DGRAM &&
551 sk->sk_protocol == IPPROTO_UDP;
552 }
553
sock_map_redirect_allowed(const struct sock * sk)554 static bool sock_map_redirect_allowed(const struct sock *sk)
555 {
556 return sk_is_tcp(sk) && sk->sk_state != TCP_LISTEN;
557 }
558
sock_map_sk_is_suitable(const struct sock * sk)559 static bool sock_map_sk_is_suitable(const struct sock *sk)
560 {
561 return sk_is_tcp(sk) || sk_is_udp(sk);
562 }
563
sock_map_sk_state_allowed(const struct sock * sk)564 static bool sock_map_sk_state_allowed(const struct sock *sk)
565 {
566 if (sk_is_tcp(sk))
567 return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
568 else if (sk_is_udp(sk))
569 return sk_hashed(sk);
570
571 return false;
572 }
573
574 static int sock_hash_update_common(struct bpf_map *map, void *key,
575 struct sock *sk, u64 flags);
576
sock_map_update_elem_sys(struct bpf_map * map,void * key,void * value,u64 flags)577 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
578 u64 flags)
579 {
580 struct socket *sock;
581 struct sock *sk;
582 int ret;
583 u64 ufd;
584
585 if (map->value_size == sizeof(u64))
586 ufd = *(u64 *)value;
587 else
588 ufd = *(u32 *)value;
589 if (ufd > S32_MAX)
590 return -EINVAL;
591
592 sock = sockfd_lookup(ufd, &ret);
593 if (!sock)
594 return ret;
595 sk = sock->sk;
596 if (!sk) {
597 ret = -EINVAL;
598 goto out;
599 }
600 if (!sock_map_sk_is_suitable(sk)) {
601 ret = -EOPNOTSUPP;
602 goto out;
603 }
604
605 sock_map_sk_acquire(sk);
606 if (!sock_map_sk_state_allowed(sk))
607 ret = -EOPNOTSUPP;
608 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
609 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
610 else
611 ret = sock_hash_update_common(map, key, sk, flags);
612 sock_map_sk_release(sk);
613 out:
614 fput(sock->file);
615 return ret;
616 }
617
sock_map_update_elem(struct bpf_map * map,void * key,void * value,u64 flags)618 static int sock_map_update_elem(struct bpf_map *map, void *key,
619 void *value, u64 flags)
620 {
621 struct sock *sk = (struct sock *)value;
622 int ret;
623
624 if (unlikely(!sk || !sk_fullsock(sk)))
625 return -EINVAL;
626
627 if (!sock_map_sk_is_suitable(sk))
628 return -EOPNOTSUPP;
629
630 local_bh_disable();
631 bh_lock_sock(sk);
632 if (!sock_map_sk_state_allowed(sk))
633 ret = -EOPNOTSUPP;
634 else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
635 ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
636 else
637 ret = sock_hash_update_common(map, key, sk, flags);
638 bh_unlock_sock(sk);
639 local_bh_enable();
640 return ret;
641 }
642
BPF_CALL_4(bpf_sock_map_update,struct bpf_sock_ops_kern *,sops,struct bpf_map *,map,void *,key,u64,flags)643 BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
644 struct bpf_map *, map, void *, key, u64, flags)
645 {
646 WARN_ON_ONCE(!rcu_read_lock_held());
647
648 if (likely(sock_map_sk_is_suitable(sops->sk) &&
649 sock_map_op_okay(sops)))
650 return sock_map_update_common(map, *(u32 *)key, sops->sk,
651 flags);
652 return -EOPNOTSUPP;
653 }
654
655 const struct bpf_func_proto bpf_sock_map_update_proto = {
656 .func = bpf_sock_map_update,
657 .gpl_only = false,
658 .pkt_access = true,
659 .ret_type = RET_INTEGER,
660 .arg1_type = ARG_PTR_TO_CTX,
661 .arg2_type = ARG_CONST_MAP_PTR,
662 .arg3_type = ARG_PTR_TO_MAP_KEY,
663 .arg4_type = ARG_ANYTHING,
664 };
665
BPF_CALL_4(bpf_sk_redirect_map,struct sk_buff *,skb,struct bpf_map *,map,u32,key,u64,flags)666 BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
667 struct bpf_map *, map, u32, key, u64, flags)
668 {
669 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
670 struct sock *sk;
671
672 if (unlikely(flags & ~(BPF_F_INGRESS)))
673 return SK_DROP;
674
675 sk = __sock_map_lookup_elem(map, key);
676 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
677 return SK_DROP;
678
679 tcb->bpf.flags = flags;
680 tcb->bpf.sk_redir = sk;
681 return SK_PASS;
682 }
683
684 const struct bpf_func_proto bpf_sk_redirect_map_proto = {
685 .func = bpf_sk_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
BPF_CALL_4(bpf_msg_redirect_map,struct sk_msg *,msg,struct bpf_map *,map,u32,key,u64,flags)694 BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
695 struct bpf_map *, map, u32, key, u64, flags)
696 {
697 struct sock *sk;
698
699 if (unlikely(flags & ~(BPF_F_INGRESS)))
700 return SK_DROP;
701
702 sk = __sock_map_lookup_elem(map, key);
703 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
704 return SK_DROP;
705
706 msg->flags = flags;
707 msg->sk_redir = sk;
708 return SK_PASS;
709 }
710
711 const struct bpf_func_proto bpf_msg_redirect_map_proto = {
712 .func = bpf_msg_redirect_map,
713 .gpl_only = false,
714 .ret_type = RET_INTEGER,
715 .arg1_type = ARG_PTR_TO_CTX,
716 .arg2_type = ARG_CONST_MAP_PTR,
717 .arg3_type = ARG_ANYTHING,
718 .arg4_type = ARG_ANYTHING,
719 };
720
721 struct sock_map_seq_info {
722 struct bpf_map *map;
723 struct sock *sk;
724 u32 index;
725 };
726
727 struct bpf_iter__sockmap {
728 __bpf_md_ptr(struct bpf_iter_meta *, meta);
729 __bpf_md_ptr(struct bpf_map *, map);
730 __bpf_md_ptr(void *, key);
731 __bpf_md_ptr(struct sock *, sk);
732 };
733
DEFINE_BPF_ITER_FUNC(sockmap,struct bpf_iter_meta * meta,struct bpf_map * map,void * key,struct sock * sk)734 DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
735 struct bpf_map *map, void *key,
736 struct sock *sk)
737
738 static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
739 {
740 if (unlikely(info->index >= info->map->max_entries))
741 return NULL;
742
743 info->sk = __sock_map_lookup_elem(info->map, info->index);
744
745 /* can't return sk directly, since that might be NULL */
746 return info;
747 }
748
sock_map_seq_start(struct seq_file * seq,loff_t * pos)749 static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
750 __acquires(rcu)
751 {
752 struct sock_map_seq_info *info = seq->private;
753
754 if (*pos == 0)
755 ++*pos;
756
757 /* pairs with sock_map_seq_stop */
758 rcu_read_lock();
759 return sock_map_seq_lookup_elem(info);
760 }
761
sock_map_seq_next(struct seq_file * seq,void * v,loff_t * pos)762 static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
763 __must_hold(rcu)
764 {
765 struct sock_map_seq_info *info = seq->private;
766
767 ++*pos;
768 ++info->index;
769
770 return sock_map_seq_lookup_elem(info);
771 }
772
sock_map_seq_show(struct seq_file * seq,void * v)773 static int sock_map_seq_show(struct seq_file *seq, void *v)
774 __must_hold(rcu)
775 {
776 struct sock_map_seq_info *info = seq->private;
777 struct bpf_iter__sockmap ctx = {};
778 struct bpf_iter_meta meta;
779 struct bpf_prog *prog;
780
781 meta.seq = seq;
782 prog = bpf_iter_get_info(&meta, !v);
783 if (!prog)
784 return 0;
785
786 ctx.meta = &meta;
787 ctx.map = info->map;
788 if (v) {
789 ctx.key = &info->index;
790 ctx.sk = info->sk;
791 }
792
793 return bpf_iter_run_prog(prog, &ctx);
794 }
795
sock_map_seq_stop(struct seq_file * seq,void * v)796 static void sock_map_seq_stop(struct seq_file *seq, void *v)
797 __releases(rcu)
798 {
799 if (!v)
800 (void)sock_map_seq_show(seq, NULL);
801
802 /* pairs with sock_map_seq_start */
803 rcu_read_unlock();
804 }
805
806 static const struct seq_operations sock_map_seq_ops = {
807 .start = sock_map_seq_start,
808 .next = sock_map_seq_next,
809 .stop = sock_map_seq_stop,
810 .show = sock_map_seq_show,
811 };
812
sock_map_init_seq_private(void * priv_data,struct bpf_iter_aux_info * aux)813 static int sock_map_init_seq_private(void *priv_data,
814 struct bpf_iter_aux_info *aux)
815 {
816 struct sock_map_seq_info *info = priv_data;
817
818 info->map = aux->map;
819 return 0;
820 }
821
822 static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
823 .seq_ops = &sock_map_seq_ops,
824 .init_seq_private = sock_map_init_seq_private,
825 .seq_priv_size = sizeof(struct sock_map_seq_info),
826 };
827
828 static int sock_map_btf_id;
829 const struct bpf_map_ops sock_map_ops = {
830 .map_meta_equal = bpf_map_meta_equal,
831 .map_alloc = sock_map_alloc,
832 .map_free = sock_map_free,
833 .map_get_next_key = sock_map_get_next_key,
834 .map_lookup_elem_sys_only = sock_map_lookup_sys,
835 .map_update_elem = sock_map_update_elem,
836 .map_delete_elem = sock_map_delete_elem,
837 .map_lookup_elem = sock_map_lookup,
838 .map_release_uref = sock_map_release_progs,
839 .map_check_btf = map_check_no_btf,
840 .map_btf_name = "bpf_stab",
841 .map_btf_id = &sock_map_btf_id,
842 .iter_seq_info = &sock_map_iter_seq_info,
843 };
844
845 struct bpf_shtab_elem {
846 struct rcu_head rcu;
847 u32 hash;
848 struct sock *sk;
849 struct hlist_node node;
850 u8 key[];
851 };
852
853 struct bpf_shtab_bucket {
854 struct hlist_head head;
855 raw_spinlock_t lock;
856 };
857
858 struct bpf_shtab {
859 struct bpf_map map;
860 struct bpf_shtab_bucket *buckets;
861 u32 buckets_num;
862 u32 elem_size;
863 struct sk_psock_progs progs;
864 atomic_t count;
865 };
866
sock_hash_bucket_hash(const void * key,u32 len)867 static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
868 {
869 return jhash(key, len, 0);
870 }
871
sock_hash_select_bucket(struct bpf_shtab * htab,u32 hash)872 static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
873 u32 hash)
874 {
875 return &htab->buckets[hash & (htab->buckets_num - 1)];
876 }
877
878 static struct bpf_shtab_elem *
sock_hash_lookup_elem_raw(struct hlist_head * head,u32 hash,void * key,u32 key_size)879 sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
880 u32 key_size)
881 {
882 struct bpf_shtab_elem *elem;
883
884 hlist_for_each_entry_rcu(elem, head, node) {
885 if (elem->hash == hash &&
886 !memcmp(&elem->key, key, key_size))
887 return elem;
888 }
889
890 return NULL;
891 }
892
__sock_hash_lookup_elem(struct bpf_map * map,void * key)893 static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
894 {
895 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
896 u32 key_size = map->key_size, hash;
897 struct bpf_shtab_bucket *bucket;
898 struct bpf_shtab_elem *elem;
899
900 WARN_ON_ONCE(!rcu_read_lock_held());
901
902 hash = sock_hash_bucket_hash(key, key_size);
903 bucket = sock_hash_select_bucket(htab, hash);
904 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
905
906 return elem ? elem->sk : NULL;
907 }
908
sock_hash_free_elem(struct bpf_shtab * htab,struct bpf_shtab_elem * elem)909 static void sock_hash_free_elem(struct bpf_shtab *htab,
910 struct bpf_shtab_elem *elem)
911 {
912 atomic_dec(&htab->count);
913 kfree_rcu(elem, rcu);
914 }
915
sock_hash_delete_from_link(struct bpf_map * map,struct sock * sk,void * link_raw)916 static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
917 void *link_raw)
918 {
919 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
920 struct bpf_shtab_elem *elem_probe, *elem = link_raw;
921 struct bpf_shtab_bucket *bucket;
922
923 WARN_ON_ONCE(!rcu_read_lock_held());
924 bucket = sock_hash_select_bucket(htab, elem->hash);
925
926 /* elem may be deleted in parallel from the map, but access here
927 * is okay since it's going away only after RCU grace period.
928 * However, we need to check whether it's still present.
929 */
930 raw_spin_lock_bh(&bucket->lock);
931 elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
932 elem->key, map->key_size);
933 if (elem_probe && elem_probe == elem) {
934 hlist_del_rcu(&elem->node);
935 sock_map_unref(elem->sk, elem);
936 sock_hash_free_elem(htab, elem);
937 }
938 raw_spin_unlock_bh(&bucket->lock);
939 }
940
sock_hash_delete_elem(struct bpf_map * map,void * key)941 static int sock_hash_delete_elem(struct bpf_map *map, void *key)
942 {
943 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
944 u32 hash, key_size = map->key_size;
945 struct bpf_shtab_bucket *bucket;
946 struct bpf_shtab_elem *elem;
947 int ret = -ENOENT;
948
949 hash = sock_hash_bucket_hash(key, key_size);
950 bucket = sock_hash_select_bucket(htab, hash);
951
952 raw_spin_lock_bh(&bucket->lock);
953 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
954 if (elem) {
955 hlist_del_rcu(&elem->node);
956 sock_map_unref(elem->sk, elem);
957 sock_hash_free_elem(htab, elem);
958 ret = 0;
959 }
960 raw_spin_unlock_bh(&bucket->lock);
961 return ret;
962 }
963
sock_hash_alloc_elem(struct bpf_shtab * htab,void * key,u32 key_size,u32 hash,struct sock * sk,struct bpf_shtab_elem * old)964 static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
965 void *key, u32 key_size,
966 u32 hash, struct sock *sk,
967 struct bpf_shtab_elem *old)
968 {
969 struct bpf_shtab_elem *new;
970
971 if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
972 if (!old) {
973 atomic_dec(&htab->count);
974 return ERR_PTR(-E2BIG);
975 }
976 }
977
978 new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
979 htab->map.numa_node);
980 if (!new) {
981 atomic_dec(&htab->count);
982 return ERR_PTR(-ENOMEM);
983 }
984 memcpy(new->key, key, key_size);
985 new->sk = sk;
986 new->hash = hash;
987 return new;
988 }
989
sock_hash_update_common(struct bpf_map * map,void * key,struct sock * sk,u64 flags)990 static int sock_hash_update_common(struct bpf_map *map, void *key,
991 struct sock *sk, u64 flags)
992 {
993 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
994 u32 key_size = map->key_size, hash;
995 struct bpf_shtab_elem *elem, *elem_new;
996 struct bpf_shtab_bucket *bucket;
997 struct sk_psock_link *link;
998 struct sk_psock *psock;
999 int ret;
1000
1001 WARN_ON_ONCE(!rcu_read_lock_held());
1002 if (unlikely(flags > BPF_EXIST))
1003 return -EINVAL;
1004
1005 link = sk_psock_init_link();
1006 if (!link)
1007 return -ENOMEM;
1008
1009 /* Only sockets we can redirect into/from in BPF need to hold
1010 * refs to parser/verdict progs and have their sk_data_ready
1011 * and sk_write_space callbacks overridden.
1012 */
1013 if (sock_map_redirect_allowed(sk))
1014 ret = sock_map_link(map, &htab->progs, sk);
1015 else
1016 ret = sock_map_link_no_progs(map, sk);
1017 if (ret < 0)
1018 goto out_free;
1019
1020 psock = sk_psock(sk);
1021 WARN_ON_ONCE(!psock);
1022
1023 hash = sock_hash_bucket_hash(key, key_size);
1024 bucket = sock_hash_select_bucket(htab, hash);
1025
1026 raw_spin_lock_bh(&bucket->lock);
1027 elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
1028 if (elem && flags == BPF_NOEXIST) {
1029 ret = -EEXIST;
1030 goto out_unlock;
1031 } else if (!elem && flags == BPF_EXIST) {
1032 ret = -ENOENT;
1033 goto out_unlock;
1034 }
1035
1036 elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
1037 if (IS_ERR(elem_new)) {
1038 ret = PTR_ERR(elem_new);
1039 goto out_unlock;
1040 }
1041
1042 sock_map_add_link(psock, link, map, elem_new);
1043 /* Add new element to the head of the list, so that
1044 * concurrent search will find it before old elem.
1045 */
1046 hlist_add_head_rcu(&elem_new->node, &bucket->head);
1047 if (elem) {
1048 hlist_del_rcu(&elem->node);
1049 sock_map_unref(elem->sk, elem);
1050 sock_hash_free_elem(htab, elem);
1051 }
1052 raw_spin_unlock_bh(&bucket->lock);
1053 return 0;
1054 out_unlock:
1055 raw_spin_unlock_bh(&bucket->lock);
1056 sk_psock_put(sk, psock);
1057 out_free:
1058 sk_psock_free_link(link);
1059 return ret;
1060 }
1061
sock_hash_get_next_key(struct bpf_map * map,void * key,void * key_next)1062 static int sock_hash_get_next_key(struct bpf_map *map, void *key,
1063 void *key_next)
1064 {
1065 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1066 struct bpf_shtab_elem *elem, *elem_next;
1067 u32 hash, key_size = map->key_size;
1068 struct hlist_head *head;
1069 int i = 0;
1070
1071 if (!key)
1072 goto find_first_elem;
1073 hash = sock_hash_bucket_hash(key, key_size);
1074 head = &sock_hash_select_bucket(htab, hash)->head;
1075 elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
1076 if (!elem)
1077 goto find_first_elem;
1078
1079 elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
1080 struct bpf_shtab_elem, node);
1081 if (elem_next) {
1082 memcpy(key_next, elem_next->key, key_size);
1083 return 0;
1084 }
1085
1086 i = hash & (htab->buckets_num - 1);
1087 i++;
1088 find_first_elem:
1089 for (; i < htab->buckets_num; i++) {
1090 head = &sock_hash_select_bucket(htab, i)->head;
1091 elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
1092 struct bpf_shtab_elem, node);
1093 if (elem_next) {
1094 memcpy(key_next, elem_next->key, key_size);
1095 return 0;
1096 }
1097 }
1098
1099 return -ENOENT;
1100 }
1101
sock_hash_alloc(union bpf_attr * attr)1102 static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
1103 {
1104 struct bpf_shtab *htab;
1105 int i, err;
1106 u64 cost;
1107
1108 if (!capable(CAP_NET_ADMIN))
1109 return ERR_PTR(-EPERM);
1110 if (attr->max_entries == 0 ||
1111 attr->key_size == 0 ||
1112 (attr->value_size != sizeof(u32) &&
1113 attr->value_size != sizeof(u64)) ||
1114 attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
1115 return ERR_PTR(-EINVAL);
1116 if (attr->key_size > MAX_BPF_STACK)
1117 return ERR_PTR(-E2BIG);
1118
1119 htab = kzalloc(sizeof(*htab), GFP_USER);
1120 if (!htab)
1121 return ERR_PTR(-ENOMEM);
1122
1123 bpf_map_init_from_attr(&htab->map, attr);
1124
1125 htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
1126 htab->elem_size = sizeof(struct bpf_shtab_elem) +
1127 round_up(htab->map.key_size, 8);
1128 if (htab->buckets_num == 0 ||
1129 htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
1130 err = -EINVAL;
1131 goto free_htab;
1132 }
1133
1134 cost = (u64) htab->buckets_num * sizeof(struct bpf_shtab_bucket) +
1135 (u64) htab->elem_size * htab->map.max_entries;
1136 if (cost >= U32_MAX - PAGE_SIZE) {
1137 err = -EINVAL;
1138 goto free_htab;
1139 }
1140 err = bpf_map_charge_init(&htab->map.memory, cost);
1141 if (err)
1142 goto free_htab;
1143
1144 htab->buckets = bpf_map_area_alloc(htab->buckets_num *
1145 sizeof(struct bpf_shtab_bucket),
1146 htab->map.numa_node);
1147 if (!htab->buckets) {
1148 bpf_map_charge_finish(&htab->map.memory);
1149 err = -ENOMEM;
1150 goto free_htab;
1151 }
1152
1153 for (i = 0; i < htab->buckets_num; i++) {
1154 INIT_HLIST_HEAD(&htab->buckets[i].head);
1155 raw_spin_lock_init(&htab->buckets[i].lock);
1156 }
1157
1158 return &htab->map;
1159 free_htab:
1160 kfree(htab);
1161 return ERR_PTR(err);
1162 }
1163
sock_hash_free(struct bpf_map * map)1164 static void sock_hash_free(struct bpf_map *map)
1165 {
1166 struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
1167 struct bpf_shtab_bucket *bucket;
1168 struct hlist_head unlink_list;
1169 struct bpf_shtab_elem *elem;
1170 struct hlist_node *node;
1171 int i;
1172
1173 /* After the sync no updates or deletes will be in-flight so it
1174 * is safe to walk map and remove entries without risking a race
1175 * in EEXIST update case.
1176 */
1177 synchronize_rcu();
1178 for (i = 0; i < htab->buckets_num; i++) {
1179 bucket = sock_hash_select_bucket(htab, i);
1180
1181 /* We are racing with sock_hash_delete_from_link to
1182 * enter the spin-lock critical section. Every socket on
1183 * the list is still linked to sockhash. Since link
1184 * exists, psock exists and holds a ref to socket. That
1185 * lets us to grab a socket ref too.
1186 */
1187 raw_spin_lock_bh(&bucket->lock);
1188 hlist_for_each_entry(elem, &bucket->head, node)
1189 sock_hold(elem->sk);
1190 hlist_move_list(&bucket->head, &unlink_list);
1191 raw_spin_unlock_bh(&bucket->lock);
1192
1193 /* Process removed entries out of atomic context to
1194 * block for socket lock before deleting the psock's
1195 * link to sockhash.
1196 */
1197 hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
1198 hlist_del(&elem->node);
1199 lock_sock(elem->sk);
1200 rcu_read_lock();
1201 sock_map_unref(elem->sk, elem);
1202 rcu_read_unlock();
1203 release_sock(elem->sk);
1204 sock_put(elem->sk);
1205 sock_hash_free_elem(htab, elem);
1206 }
1207 }
1208
1209 /* wait for psock readers accessing its map link */
1210 synchronize_rcu();
1211
1212 bpf_map_area_free(htab->buckets);
1213 kfree(htab);
1214 }
1215
sock_hash_lookup_sys(struct bpf_map * map,void * key)1216 static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
1217 {
1218 struct sock *sk;
1219
1220 if (map->value_size != sizeof(u64))
1221 return ERR_PTR(-ENOSPC);
1222
1223 sk = __sock_hash_lookup_elem(map, key);
1224 if (!sk)
1225 return ERR_PTR(-ENOENT);
1226
1227 __sock_gen_cookie(sk);
1228 return &sk->sk_cookie;
1229 }
1230
sock_hash_lookup(struct bpf_map * map,void * key)1231 static void *sock_hash_lookup(struct bpf_map *map, void *key)
1232 {
1233 struct sock *sk;
1234
1235 sk = __sock_hash_lookup_elem(map, key);
1236 if (!sk)
1237 return NULL;
1238 if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
1239 return NULL;
1240 return sk;
1241 }
1242
sock_hash_release_progs(struct bpf_map * map)1243 static void sock_hash_release_progs(struct bpf_map *map)
1244 {
1245 psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
1246 }
1247
BPF_CALL_4(bpf_sock_hash_update,struct bpf_sock_ops_kern *,sops,struct bpf_map *,map,void *,key,u64,flags)1248 BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
1249 struct bpf_map *, map, void *, key, u64, flags)
1250 {
1251 WARN_ON_ONCE(!rcu_read_lock_held());
1252
1253 if (likely(sock_map_sk_is_suitable(sops->sk) &&
1254 sock_map_op_okay(sops)))
1255 return sock_hash_update_common(map, key, sops->sk, flags);
1256 return -EOPNOTSUPP;
1257 }
1258
1259 const struct bpf_func_proto bpf_sock_hash_update_proto = {
1260 .func = bpf_sock_hash_update,
1261 .gpl_only = false,
1262 .pkt_access = true,
1263 .ret_type = RET_INTEGER,
1264 .arg1_type = ARG_PTR_TO_CTX,
1265 .arg2_type = ARG_CONST_MAP_PTR,
1266 .arg3_type = ARG_PTR_TO_MAP_KEY,
1267 .arg4_type = ARG_ANYTHING,
1268 };
1269
BPF_CALL_4(bpf_sk_redirect_hash,struct sk_buff *,skb,struct bpf_map *,map,void *,key,u64,flags)1270 BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
1271 struct bpf_map *, map, void *, key, u64, flags)
1272 {
1273 struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
1274 struct sock *sk;
1275
1276 if (unlikely(flags & ~(BPF_F_INGRESS)))
1277 return SK_DROP;
1278
1279 sk = __sock_hash_lookup_elem(map, key);
1280 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1281 return SK_DROP;
1282
1283 tcb->bpf.flags = flags;
1284 tcb->bpf.sk_redir = sk;
1285 return SK_PASS;
1286 }
1287
1288 const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
1289 .func = bpf_sk_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
BPF_CALL_4(bpf_msg_redirect_hash,struct sk_msg *,msg,struct bpf_map *,map,void *,key,u64,flags)1298 BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
1299 struct bpf_map *, map, void *, key, u64, flags)
1300 {
1301 struct sock *sk;
1302
1303 if (unlikely(flags & ~(BPF_F_INGRESS)))
1304 return SK_DROP;
1305
1306 sk = __sock_hash_lookup_elem(map, key);
1307 if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
1308 return SK_DROP;
1309
1310 msg->flags = flags;
1311 msg->sk_redir = sk;
1312 return SK_PASS;
1313 }
1314
1315 const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
1316 .func = bpf_msg_redirect_hash,
1317 .gpl_only = false,
1318 .ret_type = RET_INTEGER,
1319 .arg1_type = ARG_PTR_TO_CTX,
1320 .arg2_type = ARG_CONST_MAP_PTR,
1321 .arg3_type = ARG_PTR_TO_MAP_KEY,
1322 .arg4_type = ARG_ANYTHING,
1323 };
1324
1325 struct sock_hash_seq_info {
1326 struct bpf_map *map;
1327 struct bpf_shtab *htab;
1328 u32 bucket_id;
1329 };
1330
sock_hash_seq_find_next(struct sock_hash_seq_info * info,struct bpf_shtab_elem * prev_elem)1331 static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
1332 struct bpf_shtab_elem *prev_elem)
1333 {
1334 const struct bpf_shtab *htab = info->htab;
1335 struct bpf_shtab_bucket *bucket;
1336 struct bpf_shtab_elem *elem;
1337 struct hlist_node *node;
1338
1339 /* try to find next elem in the same bucket */
1340 if (prev_elem) {
1341 node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
1342 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1343 if (elem)
1344 return elem;
1345
1346 /* no more elements, continue in the next bucket */
1347 info->bucket_id++;
1348 }
1349
1350 for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
1351 bucket = &htab->buckets[info->bucket_id];
1352 node = rcu_dereference(hlist_first_rcu(&bucket->head));
1353 elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
1354 if (elem)
1355 return elem;
1356 }
1357
1358 return NULL;
1359 }
1360
sock_hash_seq_start(struct seq_file * seq,loff_t * pos)1361 static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
1362 __acquires(rcu)
1363 {
1364 struct sock_hash_seq_info *info = seq->private;
1365
1366 if (*pos == 0)
1367 ++*pos;
1368
1369 /* pairs with sock_hash_seq_stop */
1370 rcu_read_lock();
1371 return sock_hash_seq_find_next(info, NULL);
1372 }
1373
sock_hash_seq_next(struct seq_file * seq,void * v,loff_t * pos)1374 static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1375 __must_hold(rcu)
1376 {
1377 struct sock_hash_seq_info *info = seq->private;
1378
1379 ++*pos;
1380 return sock_hash_seq_find_next(info, v);
1381 }
1382
sock_hash_seq_show(struct seq_file * seq,void * v)1383 static int sock_hash_seq_show(struct seq_file *seq, void *v)
1384 __must_hold(rcu)
1385 {
1386 struct sock_hash_seq_info *info = seq->private;
1387 struct bpf_iter__sockmap ctx = {};
1388 struct bpf_shtab_elem *elem = v;
1389 struct bpf_iter_meta meta;
1390 struct bpf_prog *prog;
1391
1392 meta.seq = seq;
1393 prog = bpf_iter_get_info(&meta, !elem);
1394 if (!prog)
1395 return 0;
1396
1397 ctx.meta = &meta;
1398 ctx.map = info->map;
1399 if (elem) {
1400 ctx.key = elem->key;
1401 ctx.sk = elem->sk;
1402 }
1403
1404 return bpf_iter_run_prog(prog, &ctx);
1405 }
1406
sock_hash_seq_stop(struct seq_file * seq,void * v)1407 static void sock_hash_seq_stop(struct seq_file *seq, void *v)
1408 __releases(rcu)
1409 {
1410 if (!v)
1411 (void)sock_hash_seq_show(seq, NULL);
1412
1413 /* pairs with sock_hash_seq_start */
1414 rcu_read_unlock();
1415 }
1416
1417 static const struct seq_operations sock_hash_seq_ops = {
1418 .start = sock_hash_seq_start,
1419 .next = sock_hash_seq_next,
1420 .stop = sock_hash_seq_stop,
1421 .show = sock_hash_seq_show,
1422 };
1423
sock_hash_init_seq_private(void * priv_data,struct bpf_iter_aux_info * aux)1424 static int sock_hash_init_seq_private(void *priv_data,
1425 struct bpf_iter_aux_info *aux)
1426 {
1427 struct sock_hash_seq_info *info = priv_data;
1428
1429 info->map = aux->map;
1430 info->htab = container_of(aux->map, struct bpf_shtab, map);
1431 return 0;
1432 }
1433
1434 static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
1435 .seq_ops = &sock_hash_seq_ops,
1436 .init_seq_private = sock_hash_init_seq_private,
1437 .seq_priv_size = sizeof(struct sock_hash_seq_info),
1438 };
1439
1440 static int sock_hash_map_btf_id;
1441 const struct bpf_map_ops sock_hash_ops = {
1442 .map_meta_equal = bpf_map_meta_equal,
1443 .map_alloc = sock_hash_alloc,
1444 .map_free = sock_hash_free,
1445 .map_get_next_key = sock_hash_get_next_key,
1446 .map_update_elem = sock_map_update_elem,
1447 .map_delete_elem = sock_hash_delete_elem,
1448 .map_lookup_elem = sock_hash_lookup,
1449 .map_lookup_elem_sys_only = sock_hash_lookup_sys,
1450 .map_release_uref = sock_hash_release_progs,
1451 .map_check_btf = map_check_no_btf,
1452 .map_btf_name = "bpf_shtab",
1453 .map_btf_id = &sock_hash_map_btf_id,
1454 .iter_seq_info = &sock_hash_iter_seq_info,
1455 };
1456
sock_map_progs(struct bpf_map * map)1457 static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
1458 {
1459 switch (map->map_type) {
1460 case BPF_MAP_TYPE_SOCKMAP:
1461 return &container_of(map, struct bpf_stab, map)->progs;
1462 case BPF_MAP_TYPE_SOCKHASH:
1463 return &container_of(map, struct bpf_shtab, map)->progs;
1464 default:
1465 break;
1466 }
1467
1468 return NULL;
1469 }
1470
sock_map_prog_update(struct bpf_map * map,struct bpf_prog * prog,struct bpf_prog * old,u32 which)1471 int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
1472 struct bpf_prog *old, u32 which)
1473 {
1474 struct sk_psock_progs *progs = sock_map_progs(map);
1475 struct bpf_prog **pprog;
1476
1477 if (!progs)
1478 return -EOPNOTSUPP;
1479
1480 switch (which) {
1481 case BPF_SK_MSG_VERDICT:
1482 pprog = &progs->msg_parser;
1483 break;
1484 case BPF_SK_SKB_STREAM_PARSER:
1485 pprog = &progs->skb_parser;
1486 break;
1487 case BPF_SK_SKB_STREAM_VERDICT:
1488 pprog = &progs->skb_verdict;
1489 break;
1490 default:
1491 return -EOPNOTSUPP;
1492 }
1493
1494 if (old)
1495 return psock_replace_prog(pprog, prog, old);
1496
1497 psock_set_prog(pprog, prog);
1498 return 0;
1499 }
1500
sock_map_unlink(struct sock * sk,struct sk_psock_link * link)1501 static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
1502 {
1503 switch (link->map->map_type) {
1504 case BPF_MAP_TYPE_SOCKMAP:
1505 return sock_map_delete_from_link(link->map, sk,
1506 link->link_raw);
1507 case BPF_MAP_TYPE_SOCKHASH:
1508 return sock_hash_delete_from_link(link->map, sk,
1509 link->link_raw);
1510 default:
1511 break;
1512 }
1513 }
1514
sock_map_remove_links(struct sock * sk,struct sk_psock * psock)1515 static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
1516 {
1517 struct sk_psock_link *link;
1518
1519 while ((link = sk_psock_link_pop(psock))) {
1520 sock_map_unlink(sk, link);
1521 sk_psock_free_link(link);
1522 }
1523 }
1524
sock_map_unhash(struct sock * sk)1525 void sock_map_unhash(struct sock *sk)
1526 {
1527 void (*saved_unhash)(struct sock *sk);
1528 struct sk_psock *psock;
1529
1530 rcu_read_lock();
1531 psock = sk_psock(sk);
1532 if (unlikely(!psock)) {
1533 rcu_read_unlock();
1534 if (sk->sk_prot->unhash)
1535 sk->sk_prot->unhash(sk);
1536 return;
1537 }
1538
1539 saved_unhash = psock->saved_unhash;
1540 sock_map_remove_links(sk, psock);
1541 rcu_read_unlock();
1542 saved_unhash(sk);
1543 }
1544
sock_map_close(struct sock * sk,long timeout)1545 void sock_map_close(struct sock *sk, long timeout)
1546 {
1547 void (*saved_close)(struct sock *sk, long timeout);
1548 struct sk_psock *psock;
1549
1550 lock_sock(sk);
1551 rcu_read_lock();
1552 psock = sk_psock(sk);
1553 if (unlikely(!psock)) {
1554 rcu_read_unlock();
1555 release_sock(sk);
1556 return sk->sk_prot->close(sk, timeout);
1557 }
1558
1559 saved_close = psock->saved_close;
1560 sock_map_remove_links(sk, psock);
1561 rcu_read_unlock();
1562 release_sock(sk);
1563 saved_close(sk, timeout);
1564 }
1565
sock_map_iter_attach_target(struct bpf_prog * prog,union bpf_iter_link_info * linfo,struct bpf_iter_aux_info * aux)1566 static int sock_map_iter_attach_target(struct bpf_prog *prog,
1567 union bpf_iter_link_info *linfo,
1568 struct bpf_iter_aux_info *aux)
1569 {
1570 struct bpf_map *map;
1571 int err = -EINVAL;
1572
1573 if (!linfo->map.map_fd)
1574 return -EBADF;
1575
1576 map = bpf_map_get_with_uref(linfo->map.map_fd);
1577 if (IS_ERR(map))
1578 return PTR_ERR(map);
1579
1580 if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
1581 map->map_type != BPF_MAP_TYPE_SOCKHASH)
1582 goto put_map;
1583
1584 if (prog->aux->max_rdonly_access > map->key_size) {
1585 err = -EACCES;
1586 goto put_map;
1587 }
1588
1589 aux->map = map;
1590 return 0;
1591
1592 put_map:
1593 bpf_map_put_with_uref(map);
1594 return err;
1595 }
1596
sock_map_iter_detach_target(struct bpf_iter_aux_info * aux)1597 static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
1598 {
1599 bpf_map_put_with_uref(aux->map);
1600 }
1601
1602 static struct bpf_iter_reg sock_map_iter_reg = {
1603 .target = "sockmap",
1604 .attach_target = sock_map_iter_attach_target,
1605 .detach_target = sock_map_iter_detach_target,
1606 .show_fdinfo = bpf_iter_map_show_fdinfo,
1607 .fill_link_info = bpf_iter_map_fill_link_info,
1608 .ctx_arg_info_size = 2,
1609 .ctx_arg_info = {
1610 { offsetof(struct bpf_iter__sockmap, key),
1611 PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY },
1612 { offsetof(struct bpf_iter__sockmap, sk),
1613 PTR_TO_BTF_ID_OR_NULL },
1614 },
1615 };
1616
bpf_sockmap_iter_init(void)1617 static int __init bpf_sockmap_iter_init(void)
1618 {
1619 sock_map_iter_reg.ctx_arg_info[1].btf_id =
1620 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
1621 return bpf_iter_reg_target(&sock_map_iter_reg);
1622 }
1623 late_initcall(bpf_sockmap_iter_init);
1624