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1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2019 Facebook */
3#include <linux/rculist.h>
4#include <linux/list.h>
5#include <linux/hash.h>
6#include <linux/types.h>
7#include <linux/spinlock.h>
8#include <linux/bpf.h>
9#include <linux/btf.h>
10#include <linux/btf_ids.h>
11#include <linux/bpf_local_storage.h>
12#include <net/bpf_sk_storage.h>
13#include <net/sock.h>
14#include <uapi/linux/sock_diag.h>
15#include <uapi/linux/btf.h>
16
17DEFINE_BPF_STORAGE_CACHE(sk_cache);
18
19static struct bpf_local_storage_data *
20bpf_sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit)
21{
22 struct bpf_local_storage *sk_storage;
23 struct bpf_local_storage_map *smap;
24
25 sk_storage = rcu_dereference(sk->sk_bpf_storage);
26 if (!sk_storage)
27 return NULL;
28
29 smap = (struct bpf_local_storage_map *)map;
30 return bpf_local_storage_lookup(sk_storage, smap, cacheit_lockit);
31}
32
33static int bpf_sk_storage_del(struct sock *sk, struct bpf_map *map)
34{
35 struct bpf_local_storage_data *sdata;
36
37 sdata = bpf_sk_storage_lookup(sk, map, false);
38 if (!sdata)
39 return -ENOENT;
40
41 bpf_selem_unlink(SELEM(sdata));
42
43 return 0;
44}
45
46/* Called by __sk_destruct() & bpf_sk_storage_clone() */
47void bpf_sk_storage_free(struct sock *sk)
48{
49 struct bpf_local_storage_elem *selem;
50 struct bpf_local_storage *sk_storage;
51 bool free_sk_storage = false;
52 struct hlist_node *n;
53
54 rcu_read_lock();
55 sk_storage = rcu_dereference(sk->sk_bpf_storage);
56 if (!sk_storage) {
57 rcu_read_unlock();
58 return;
59 }
60
61 /* Netiher the bpf_prog nor the bpf-map's syscall
62 * could be modifying the sk_storage->list now.
63 * Thus, no elem can be added-to or deleted-from the
64 * sk_storage->list by the bpf_prog or by the bpf-map's syscall.
65 *
66 * It is racing with bpf_local_storage_map_free() alone
67 * when unlinking elem from the sk_storage->list and
68 * the map's bucket->list.
69 */
70 raw_spin_lock_bh(&sk_storage->lock);
71 hlist_for_each_entry_safe(selem, n, &sk_storage->list, snode) {
72 /* Always unlink from map before unlinking from
73 * sk_storage.
74 */
75 bpf_selem_unlink_map(selem);
76 free_sk_storage = bpf_selem_unlink_storage_nolock(sk_storage,
77 selem, true);
78 }
79 raw_spin_unlock_bh(&sk_storage->lock);
80 rcu_read_unlock();
81
82 if (free_sk_storage)
83 kfree_rcu(sk_storage, rcu);
84}
85
86static void bpf_sk_storage_map_free(struct bpf_map *map)
87{
88 struct bpf_local_storage_map *smap;
89
90 smap = (struct bpf_local_storage_map *)map;
91 bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx);
92 bpf_local_storage_map_free(smap, NULL);
93}
94
95static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
96{
97 struct bpf_local_storage_map *smap;
98
99 smap = bpf_local_storage_map_alloc(attr);
100 if (IS_ERR(smap))
101 return ERR_CAST(smap);
102
103 smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache);
104 return &smap->map;
105}
106
107static int notsupp_get_next_key(struct bpf_map *map, void *key,
108 void *next_key)
109{
110 return -ENOTSUPP;
111}
112
113static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key)
114{
115 struct bpf_local_storage_data *sdata;
116 struct socket *sock;
117 int fd, err;
118
119 fd = *(int *)key;
120 sock = sockfd_lookup(fd, &err);
121 if (sock) {
122 sdata = bpf_sk_storage_lookup(sock->sk, map, true);
123 sockfd_put(sock);
124 return sdata ? sdata->data : NULL;
125 }
126
127 return ERR_PTR(err);
128}
129
130static int bpf_fd_sk_storage_update_elem(struct bpf_map *map, void *key,
131 void *value, u64 map_flags)
132{
133 struct bpf_local_storage_data *sdata;
134 struct socket *sock;
135 int fd, err;
136
137 fd = *(int *)key;
138 sock = sockfd_lookup(fd, &err);
139 if (sock) {
140 sdata = bpf_local_storage_update(
141 sock->sk, (struct bpf_local_storage_map *)map, value,
142 map_flags);
143 sockfd_put(sock);
144 return PTR_ERR_OR_ZERO(sdata);
145 }
146
147 return err;
148}
149
150static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key)
151{
152 struct socket *sock;
153 int fd, err;
154
155 fd = *(int *)key;
156 sock = sockfd_lookup(fd, &err);
157 if (sock) {
158 err = bpf_sk_storage_del(sock->sk, map);
159 sockfd_put(sock);
160 return err;
161 }
162
163 return err;
164}
165
166static struct bpf_local_storage_elem *
167bpf_sk_storage_clone_elem(struct sock *newsk,
168 struct bpf_local_storage_map *smap,
169 struct bpf_local_storage_elem *selem)
170{
171 struct bpf_local_storage_elem *copy_selem;
172
173 copy_selem = bpf_selem_alloc(smap, newsk, NULL, true);
174 if (!copy_selem)
175 return NULL;
176
177 if (map_value_has_spin_lock(&smap->map))
178 copy_map_value_locked(&smap->map, SDATA(copy_selem)->data,
179 SDATA(selem)->data, true);
180 else
181 copy_map_value(&smap->map, SDATA(copy_selem)->data,
182 SDATA(selem)->data);
183
184 return copy_selem;
185}
186
187int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
188{
189 struct bpf_local_storage *new_sk_storage = NULL;
190 struct bpf_local_storage *sk_storage;
191 struct bpf_local_storage_elem *selem;
192 int ret = 0;
193
194 RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL);
195
196 rcu_read_lock();
197 sk_storage = rcu_dereference(sk->sk_bpf_storage);
198
199 if (!sk_storage || hlist_empty(&sk_storage->list))
200 goto out;
201
202 hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) {
203 struct bpf_local_storage_elem *copy_selem;
204 struct bpf_local_storage_map *smap;
205 struct bpf_map *map;
206
207 smap = rcu_dereference(SDATA(selem)->smap);
208 if (!(smap->map.map_flags & BPF_F_CLONE))
209 continue;
210
211 /* Note that for lockless listeners adding new element
212 * here can race with cleanup in bpf_local_storage_map_free.
213 * Try to grab map refcnt to make sure that it's still
214 * alive and prevent concurrent removal.
215 */
216 map = bpf_map_inc_not_zero(&smap->map);
217 if (IS_ERR(map))
218 continue;
219
220 copy_selem = bpf_sk_storage_clone_elem(newsk, smap, selem);
221 if (!copy_selem) {
222 ret = -ENOMEM;
223 bpf_map_put(map);
224 goto out;
225 }
226
227 if (new_sk_storage) {
228 bpf_selem_link_map(smap, copy_selem);
229 bpf_selem_link_storage_nolock(new_sk_storage, copy_selem);
230 } else {
231 ret = bpf_local_storage_alloc(newsk, smap, copy_selem);
232 if (ret) {
233 kfree(copy_selem);
234 atomic_sub(smap->elem_size,
235 &newsk->sk_omem_alloc);
236 bpf_map_put(map);
237 goto out;
238 }
239
240 new_sk_storage =
241 rcu_dereference(copy_selem->local_storage);
242 }
243 bpf_map_put(map);
244 }
245
246out:
247 rcu_read_unlock();
248
249 /* In case of an error, don't free anything explicitly here, the
250 * caller is responsible to call bpf_sk_storage_free.
251 */
252
253 return ret;
254}
255
256BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
257 void *, value, u64, flags)
258{
259 struct bpf_local_storage_data *sdata;
260
261 if (!sk || !sk_fullsock(sk) || flags > BPF_SK_STORAGE_GET_F_CREATE)
262 return (unsigned long)NULL;
263
264 sdata = bpf_sk_storage_lookup(sk, map, true);
265 if (sdata)
266 return (unsigned long)sdata->data;
267
268 if (flags == BPF_SK_STORAGE_GET_F_CREATE &&
269 /* Cannot add new elem to a going away sk.
270 * Otherwise, the new elem may become a leak
271 * (and also other memory issues during map
272 * destruction).
273 */
274 refcount_inc_not_zero(&sk->sk_refcnt)) {
275 sdata = bpf_local_storage_update(
276 sk, (struct bpf_local_storage_map *)map, value,
277 BPF_NOEXIST);
278 /* sk must be a fullsock (guaranteed by verifier),
279 * so sock_gen_put() is unnecessary.
280 */
281 sock_put(sk);
282 return IS_ERR(sdata) ?
283 (unsigned long)NULL : (unsigned long)sdata->data;
284 }
285
286 return (unsigned long)NULL;
287}
288
289BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)
290{
291 if (!sk || !sk_fullsock(sk))
292 return -EINVAL;
293
294 if (refcount_inc_not_zero(&sk->sk_refcnt)) {
295 int err;
296
297 err = bpf_sk_storage_del(sk, map);
298 sock_put(sk);
299 return err;
300 }
301
302 return -ENOENT;
303}
304
305static int bpf_sk_storage_charge(struct bpf_local_storage_map *smap,
306 void *owner, u32 size)
307{
308 struct sock *sk = (struct sock *)owner;
309
310 /* same check as in sock_kmalloc() */
311 if (size <= sysctl_optmem_max &&
312 atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
313 atomic_add(size, &sk->sk_omem_alloc);
314 return 0;
315 }
316
317 return -ENOMEM;
318}
319
320static void bpf_sk_storage_uncharge(struct bpf_local_storage_map *smap,
321 void *owner, u32 size)
322{
323 struct sock *sk = owner;
324
325 atomic_sub(size, &sk->sk_omem_alloc);
326}
327
328static struct bpf_local_storage __rcu **
329bpf_sk_storage_ptr(void *owner)
330{
331 struct sock *sk = owner;
332
333 return &sk->sk_bpf_storage;
334}
335
336static int sk_storage_map_btf_id;
337const struct bpf_map_ops sk_storage_map_ops = {
338 .map_meta_equal = bpf_map_meta_equal,
339 .map_alloc_check = bpf_local_storage_map_alloc_check,
340 .map_alloc = bpf_sk_storage_map_alloc,
341 .map_free = bpf_sk_storage_map_free,
342 .map_get_next_key = notsupp_get_next_key,
343 .map_lookup_elem = bpf_fd_sk_storage_lookup_elem,
344 .map_update_elem = bpf_fd_sk_storage_update_elem,
345 .map_delete_elem = bpf_fd_sk_storage_delete_elem,
346 .map_check_btf = bpf_local_storage_map_check_btf,
347 .map_btf_name = "bpf_local_storage_map",
348 .map_btf_id = &sk_storage_map_btf_id,
349 .map_local_storage_charge = bpf_sk_storage_charge,
350 .map_local_storage_uncharge = bpf_sk_storage_uncharge,
351 .map_owner_storage_ptr = bpf_sk_storage_ptr,
352};
353
354const struct bpf_func_proto bpf_sk_storage_get_proto = {
355 .func = bpf_sk_storage_get,
356 .gpl_only = false,
357 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
358 .arg1_type = ARG_CONST_MAP_PTR,
359 .arg2_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
360 .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
361 .arg4_type = ARG_ANYTHING,
362};
363
364const struct bpf_func_proto bpf_sk_storage_get_cg_sock_proto = {
365 .func = bpf_sk_storage_get,
366 .gpl_only = false,
367 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
368 .arg1_type = ARG_CONST_MAP_PTR,
369 .arg2_type = ARG_PTR_TO_CTX, /* context is 'struct sock' */
370 .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
371 .arg4_type = ARG_ANYTHING,
372};
373
374const struct bpf_func_proto bpf_sk_storage_delete_proto = {
375 .func = bpf_sk_storage_delete,
376 .gpl_only = false,
377 .ret_type = RET_INTEGER,
378 .arg1_type = ARG_CONST_MAP_PTR,
379 .arg2_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
380};
381
382static bool bpf_sk_storage_tracing_allowed(const struct bpf_prog *prog)
383{
384 const struct btf *btf_vmlinux;
385 const struct btf_type *t;
386 const char *tname;
387 u32 btf_id;
388
389 if (prog->aux->dst_prog)
390 return false;
391
392 /* Ensure the tracing program is not tracing
393 * any bpf_sk_storage*() function and also
394 * use the bpf_sk_storage_(get|delete) helper.
395 */
396 switch (prog->expected_attach_type) {
397 case BPF_TRACE_ITER:
398 case BPF_TRACE_RAW_TP:
399 /* bpf_sk_storage has no trace point */
400 return true;
401 case BPF_TRACE_FENTRY:
402 case BPF_TRACE_FEXIT:
403 btf_vmlinux = bpf_get_btf_vmlinux();
404 btf_id = prog->aux->attach_btf_id;
405 t = btf_type_by_id(btf_vmlinux, btf_id);
406 tname = btf_name_by_offset(btf_vmlinux, t->name_off);
407 return !!strncmp(tname, "bpf_sk_storage",
408 strlen("bpf_sk_storage"));
409 default:
410 return false;
411 }
412
413 return false;
414}
415
416BPF_CALL_4(bpf_sk_storage_get_tracing, struct bpf_map *, map, struct sock *, sk,
417 void *, value, u64, flags)
418{
419 if (in_irq() || in_nmi())
420 return (unsigned long)NULL;
421
422 return (unsigned long)____bpf_sk_storage_get(map, sk, value, flags);
423}
424
425BPF_CALL_2(bpf_sk_storage_delete_tracing, struct bpf_map *, map,
426 struct sock *, sk)
427{
428 if (in_irq() || in_nmi())
429 return -EPERM;
430
431 return ____bpf_sk_storage_delete(map, sk);
432}
433
434const struct bpf_func_proto bpf_sk_storage_get_tracing_proto = {
435 .func = bpf_sk_storage_get_tracing,
436 .gpl_only = false,
437 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
438 .arg1_type = ARG_CONST_MAP_PTR,
439 .arg2_type = ARG_PTR_TO_BTF_ID,
440 .arg2_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
441 .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
442 .arg4_type = ARG_ANYTHING,
443 .allowed = bpf_sk_storage_tracing_allowed,
444};
445
446const struct bpf_func_proto bpf_sk_storage_delete_tracing_proto = {
447 .func = bpf_sk_storage_delete_tracing,
448 .gpl_only = false,
449 .ret_type = RET_INTEGER,
450 .arg1_type = ARG_CONST_MAP_PTR,
451 .arg2_type = ARG_PTR_TO_BTF_ID,
452 .arg2_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
453 .allowed = bpf_sk_storage_tracing_allowed,
454};
455
456struct bpf_sk_storage_diag {
457 u32 nr_maps;
458 struct bpf_map *maps[];
459};
460
461/* The reply will be like:
462 * INET_DIAG_BPF_SK_STORAGES (nla_nest)
463 * SK_DIAG_BPF_STORAGE (nla_nest)
464 * SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
465 * SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
466 * SK_DIAG_BPF_STORAGE (nla_nest)
467 * SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
468 * SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
469 * ....
470 */
471static int nla_value_size(u32 value_size)
472{
473 /* SK_DIAG_BPF_STORAGE (nla_nest)
474 * SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
475 * SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
476 */
477 return nla_total_size(0) + nla_total_size(sizeof(u32)) +
478 nla_total_size_64bit(value_size);
479}
480
481void bpf_sk_storage_diag_free(struct bpf_sk_storage_diag *diag)
482{
483 u32 i;
484
485 if (!diag)
486 return;
487
488 for (i = 0; i < diag->nr_maps; i++)
489 bpf_map_put(diag->maps[i]);
490
491 kfree(diag);
492}
493EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_free);
494
495static bool diag_check_dup(const struct bpf_sk_storage_diag *diag,
496 const struct bpf_map *map)
497{
498 u32 i;
499
500 for (i = 0; i < diag->nr_maps; i++) {
501 if (diag->maps[i] == map)
502 return true;
503 }
504
505 return false;
506}
507
508struct bpf_sk_storage_diag *
509bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs)
510{
511 struct bpf_sk_storage_diag *diag;
512 struct nlattr *nla;
513 u32 nr_maps = 0;
514 int rem, err;
515
516 /* bpf_local_storage_map is currently limited to CAP_SYS_ADMIN as
517 * the map_alloc_check() side also does.
518 */
519 if (!bpf_capable())
520 return ERR_PTR(-EPERM);
521
522 nla_for_each_nested(nla, nla_stgs, rem) {
523 if (nla_type(nla) == SK_DIAG_BPF_STORAGE_REQ_MAP_FD)
524 nr_maps++;
525 }
526
527 diag = kzalloc(struct_size(diag, maps, nr_maps), GFP_KERNEL);
528 if (!diag)
529 return ERR_PTR(-ENOMEM);
530
531 nla_for_each_nested(nla, nla_stgs, rem) {
532 struct bpf_map *map;
533 int map_fd;
534
535 if (nla_type(nla) != SK_DIAG_BPF_STORAGE_REQ_MAP_FD)
536 continue;
537
538 map_fd = nla_get_u32(nla);
539 map = bpf_map_get(map_fd);
540 if (IS_ERR(map)) {
541 err = PTR_ERR(map);
542 goto err_free;
543 }
544 if (map->map_type != BPF_MAP_TYPE_SK_STORAGE) {
545 bpf_map_put(map);
546 err = -EINVAL;
547 goto err_free;
548 }
549 if (diag_check_dup(diag, map)) {
550 bpf_map_put(map);
551 err = -EEXIST;
552 goto err_free;
553 }
554 diag->maps[diag->nr_maps++] = map;
555 }
556
557 return diag;
558
559err_free:
560 bpf_sk_storage_diag_free(diag);
561 return ERR_PTR(err);
562}
563EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_alloc);
564
565static int diag_get(struct bpf_local_storage_data *sdata, struct sk_buff *skb)
566{
567 struct nlattr *nla_stg, *nla_value;
568 struct bpf_local_storage_map *smap;
569
570 /* It cannot exceed max nlattr's payload */
571 BUILD_BUG_ON(U16_MAX - NLA_HDRLEN < BPF_LOCAL_STORAGE_MAX_VALUE_SIZE);
572
573 nla_stg = nla_nest_start(skb, SK_DIAG_BPF_STORAGE);
574 if (!nla_stg)
575 return -EMSGSIZE;
576
577 smap = rcu_dereference(sdata->smap);
578 if (nla_put_u32(skb, SK_DIAG_BPF_STORAGE_MAP_ID, smap->map.id))
579 goto errout;
580
581 nla_value = nla_reserve_64bit(skb, SK_DIAG_BPF_STORAGE_MAP_VALUE,
582 smap->map.value_size,
583 SK_DIAG_BPF_STORAGE_PAD);
584 if (!nla_value)
585 goto errout;
586
587 if (map_value_has_spin_lock(&smap->map))
588 copy_map_value_locked(&smap->map, nla_data(nla_value),
589 sdata->data, true);
590 else
591 copy_map_value(&smap->map, nla_data(nla_value), sdata->data);
592
593 nla_nest_end(skb, nla_stg);
594 return 0;
595
596errout:
597 nla_nest_cancel(skb, nla_stg);
598 return -EMSGSIZE;
599}
600
601static int bpf_sk_storage_diag_put_all(struct sock *sk, struct sk_buff *skb,
602 int stg_array_type,
603 unsigned int *res_diag_size)
604{
605 /* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */
606 unsigned int diag_size = nla_total_size(0);
607 struct bpf_local_storage *sk_storage;
608 struct bpf_local_storage_elem *selem;
609 struct bpf_local_storage_map *smap;
610 struct nlattr *nla_stgs;
611 unsigned int saved_len;
612 int err = 0;
613
614 rcu_read_lock();
615
616 sk_storage = rcu_dereference(sk->sk_bpf_storage);
617 if (!sk_storage || hlist_empty(&sk_storage->list)) {
618 rcu_read_unlock();
619 return 0;
620 }
621
622 nla_stgs = nla_nest_start(skb, stg_array_type);
623 if (!nla_stgs)
624 /* Continue to learn diag_size */
625 err = -EMSGSIZE;
626
627 saved_len = skb->len;
628 hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) {
629 smap = rcu_dereference(SDATA(selem)->smap);
630 diag_size += nla_value_size(smap->map.value_size);
631
632 if (nla_stgs && diag_get(SDATA(selem), skb))
633 /* Continue to learn diag_size */
634 err = -EMSGSIZE;
635 }
636
637 rcu_read_unlock();
638
639 if (nla_stgs) {
640 if (saved_len == skb->len)
641 nla_nest_cancel(skb, nla_stgs);
642 else
643 nla_nest_end(skb, nla_stgs);
644 }
645
646 if (diag_size == nla_total_size(0)) {
647 *res_diag_size = 0;
648 return 0;
649 }
650
651 *res_diag_size = diag_size;
652 return err;
653}
654
655int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag,
656 struct sock *sk, struct sk_buff *skb,
657 int stg_array_type,
658 unsigned int *res_diag_size)
659{
660 /* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */
661 unsigned int diag_size = nla_total_size(0);
662 struct bpf_local_storage *sk_storage;
663 struct bpf_local_storage_data *sdata;
664 struct nlattr *nla_stgs;
665 unsigned int saved_len;
666 int err = 0;
667 u32 i;
668
669 *res_diag_size = 0;
670
671 /* No map has been specified. Dump all. */
672 if (!diag->nr_maps)
673 return bpf_sk_storage_diag_put_all(sk, skb, stg_array_type,
674 res_diag_size);
675
676 rcu_read_lock();
677 sk_storage = rcu_dereference(sk->sk_bpf_storage);
678 if (!sk_storage || hlist_empty(&sk_storage->list)) {
679 rcu_read_unlock();
680 return 0;
681 }
682
683 nla_stgs = nla_nest_start(skb, stg_array_type);
684 if (!nla_stgs)
685 /* Continue to learn diag_size */
686 err = -EMSGSIZE;
687
688 saved_len = skb->len;
689 for (i = 0; i < diag->nr_maps; i++) {
690 sdata = bpf_local_storage_lookup(sk_storage,
691 (struct bpf_local_storage_map *)diag->maps[i],
692 false);
693
694 if (!sdata)
695 continue;
696
697 diag_size += nla_value_size(diag->maps[i]->value_size);
698
699 if (nla_stgs && diag_get(sdata, skb))
700 /* Continue to learn diag_size */
701 err = -EMSGSIZE;
702 }
703 rcu_read_unlock();
704
705 if (nla_stgs) {
706 if (saved_len == skb->len)
707 nla_nest_cancel(skb, nla_stgs);
708 else
709 nla_nest_end(skb, nla_stgs);
710 }
711
712 if (diag_size == nla_total_size(0)) {
713 *res_diag_size = 0;
714 return 0;
715 }
716
717 *res_diag_size = diag_size;
718 return err;
719}
720EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_put);
721
722struct bpf_iter_seq_sk_storage_map_info {
723 struct bpf_map *map;
724 unsigned int bucket_id;
725 unsigned skip_elems;
726};
727
728static struct bpf_local_storage_elem *
729bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info,
730 struct bpf_local_storage_elem *prev_selem)
731 __acquires(RCU) __releases(RCU)
732{
733 struct bpf_local_storage *sk_storage;
734 struct bpf_local_storage_elem *selem;
735 u32 skip_elems = info->skip_elems;
736 struct bpf_local_storage_map *smap;
737 u32 bucket_id = info->bucket_id;
738 u32 i, count, n_buckets;
739 struct bpf_local_storage_map_bucket *b;
740
741 smap = (struct bpf_local_storage_map *)info->map;
742 n_buckets = 1U << smap->bucket_log;
743 if (bucket_id >= n_buckets)
744 return NULL;
745
746 /* try to find next selem in the same bucket */
747 selem = prev_selem;
748 count = 0;
749 while (selem) {
750 selem = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&selem->map_node)),
751 struct bpf_local_storage_elem, map_node);
752 if (!selem) {
753 /* not found, unlock and go to the next bucket */
754 b = &smap->buckets[bucket_id++];
755 rcu_read_unlock();
756 skip_elems = 0;
757 break;
758 }
759 sk_storage = rcu_dereference(selem->local_storage);
760 if (sk_storage) {
761 info->skip_elems = skip_elems + count;
762 return selem;
763 }
764 count++;
765 }
766
767 for (i = bucket_id; i < (1U << smap->bucket_log); i++) {
768 b = &smap->buckets[i];
769 rcu_read_lock();
770 count = 0;
771 hlist_for_each_entry_rcu(selem, &b->list, map_node) {
772 sk_storage = rcu_dereference(selem->local_storage);
773 if (sk_storage && count >= skip_elems) {
774 info->bucket_id = i;
775 info->skip_elems = count;
776 return selem;
777 }
778 count++;
779 }
780 rcu_read_unlock();
781 skip_elems = 0;
782 }
783
784 info->bucket_id = i;
785 info->skip_elems = 0;
786 return NULL;
787}
788
789static void *bpf_sk_storage_map_seq_start(struct seq_file *seq, loff_t *pos)
790{
791 struct bpf_local_storage_elem *selem;
792
793 selem = bpf_sk_storage_map_seq_find_next(seq->private, NULL);
794 if (!selem)
795 return NULL;
796
797 if (*pos == 0)
798 ++*pos;
799 return selem;
800}
801
802static void *bpf_sk_storage_map_seq_next(struct seq_file *seq, void *v,
803 loff_t *pos)
804{
805 struct bpf_iter_seq_sk_storage_map_info *info = seq->private;
806
807 ++*pos;
808 ++info->skip_elems;
809 return bpf_sk_storage_map_seq_find_next(seq->private, v);
810}
811
812struct bpf_iter__bpf_sk_storage_map {
813 __bpf_md_ptr(struct bpf_iter_meta *, meta);
814 __bpf_md_ptr(struct bpf_map *, map);
815 __bpf_md_ptr(struct sock *, sk);
816 __bpf_md_ptr(void *, value);
817};
818
819DEFINE_BPF_ITER_FUNC(bpf_sk_storage_map, struct bpf_iter_meta *meta,
820 struct bpf_map *map, struct sock *sk,
821 void *value)
822
823static int __bpf_sk_storage_map_seq_show(struct seq_file *seq,
824 struct bpf_local_storage_elem *selem)
825{
826 struct bpf_iter_seq_sk_storage_map_info *info = seq->private;
827 struct bpf_iter__bpf_sk_storage_map ctx = {};
828 struct bpf_local_storage *sk_storage;
829 struct bpf_iter_meta meta;
830 struct bpf_prog *prog;
831 int ret = 0;
832
833 meta.seq = seq;
834 prog = bpf_iter_get_info(&meta, selem == NULL);
835 if (prog) {
836 ctx.meta = &meta;
837 ctx.map = info->map;
838 if (selem) {
839 sk_storage = rcu_dereference(selem->local_storage);
840 ctx.sk = sk_storage->owner;
841 ctx.value = SDATA(selem)->data;
842 }
843 ret = bpf_iter_run_prog(prog, &ctx);
844 }
845
846 return ret;
847}
848
849static int bpf_sk_storage_map_seq_show(struct seq_file *seq, void *v)
850{
851 return __bpf_sk_storage_map_seq_show(seq, v);
852}
853
854static void bpf_sk_storage_map_seq_stop(struct seq_file *seq, void *v)
855 __releases(RCU)
856{
857 if (!v)
858 (void)__bpf_sk_storage_map_seq_show(seq, v);
859 else
860 rcu_read_unlock();
861}
862
863static int bpf_iter_init_sk_storage_map(void *priv_data,
864 struct bpf_iter_aux_info *aux)
865{
866 struct bpf_iter_seq_sk_storage_map_info *seq_info = priv_data;
867
868 seq_info->map = aux->map;
869 return 0;
870}
871
872static int bpf_iter_attach_map(struct bpf_prog *prog,
873 union bpf_iter_link_info *linfo,
874 struct bpf_iter_aux_info *aux)
875{
876 struct bpf_map *map;
877 int err = -EINVAL;
878
879 if (!linfo->map.map_fd)
880 return -EBADF;
881
882 map = bpf_map_get_with_uref(linfo->map.map_fd);
883 if (IS_ERR(map))
884 return PTR_ERR(map);
885
886 if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
887 goto put_map;
888
889 if (prog->aux->max_rdonly_access > map->value_size) {
890 err = -EACCES;
891 goto put_map;
892 }
893
894 aux->map = map;
895 return 0;
896
897put_map:
898 bpf_map_put_with_uref(map);
899 return err;
900}
901
902static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
903{
904 bpf_map_put_with_uref(aux->map);
905}
906
907static const struct seq_operations bpf_sk_storage_map_seq_ops = {
908 .start = bpf_sk_storage_map_seq_start,
909 .next = bpf_sk_storage_map_seq_next,
910 .stop = bpf_sk_storage_map_seq_stop,
911 .show = bpf_sk_storage_map_seq_show,
912};
913
914static const struct bpf_iter_seq_info iter_seq_info = {
915 .seq_ops = &bpf_sk_storage_map_seq_ops,
916 .init_seq_private = bpf_iter_init_sk_storage_map,
917 .fini_seq_private = NULL,
918 .seq_priv_size = sizeof(struct bpf_iter_seq_sk_storage_map_info),
919};
920
921static struct bpf_iter_reg bpf_sk_storage_map_reg_info = {
922 .target = "bpf_sk_storage_map",
923 .attach_target = bpf_iter_attach_map,
924 .detach_target = bpf_iter_detach_map,
925 .show_fdinfo = bpf_iter_map_show_fdinfo,
926 .fill_link_info = bpf_iter_map_fill_link_info,
927 .ctx_arg_info_size = 2,
928 .ctx_arg_info = {
929 { offsetof(struct bpf_iter__bpf_sk_storage_map, sk),
930 PTR_TO_BTF_ID_OR_NULL },
931 { offsetof(struct bpf_iter__bpf_sk_storage_map, value),
932 PTR_TO_RDWR_BUF_OR_NULL },
933 },
934 .seq_info = &iter_seq_info,
935};
936
937static int __init bpf_sk_storage_map_iter_init(void)
938{
939 bpf_sk_storage_map_reg_info.ctx_arg_info[0].btf_id =
940 btf_sock_ids[BTF_SOCK_TYPE_SOCK];
941 return bpf_iter_reg_target(&bpf_sk_storage_map_reg_info);
942}
943late_initcall(bpf_sk_storage_map_iter_init);