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604326b4 DB |
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 | ||
14 | struct 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 | ||
24 | static 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 *); | |
c85d6913 | 47 | err = bpf_map_charge_init(&stab->map.memory, cost); |
604326b4 DB |
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; | |
b936ca64 | 57 | bpf_map_charge_finish(&stab->map.memory); |
604326b4 DB |
58 | free_stab: |
59 | kfree(stab); | |
60 | return ERR_PTR(err); | |
61 | } | |
62 | ||
63 | int 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 | ||
79 | static 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 | ||
87 | static 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 | ||
95 | static 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 | ||
106 | static 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 | ||
132 | static 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 | ||
142 | static 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 | ||
5032d079 JF |
173 | psock = sk_psock_get_checked(sk); |
174 | if (IS_ERR(psock)) { | |
175 | ret = PTR_ERR(psock); | |
176 | goto out_progs; | |
177 | } | |
178 | ||
604326b4 | 179 | if (psock) { |
604326b4 DB |
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; | |
218 | out_drop: | |
219 | sk_psock_put(sk, psock); | |
220 | out_progs: | |
221 | if (msg_parser) | |
222 | bpf_prog_put(msg_parser); | |
223 | out: | |
224 | if (skb_progs) { | |
225 | bpf_prog_put(skb_verdict); | |
226 | bpf_prog_put(skb_parser); | |
227 | } | |
228 | return ret; | |
229 | } | |
230 | ||
231 | static 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 | ||
2bb90e5c JF |
250 | synchronize_rcu(); |
251 | ||
604326b4 DB |
252 | bpf_map_area_free(stab->sks); |
253 | kfree(stab); | |
254 | } | |
255 | ||
256 | static void sock_map_release_progs(struct bpf_map *map) | |
257 | { | |
258 | psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs); | |
259 | } | |
260 | ||
261 | static 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 | ||
272 | static void *sock_map_lookup(struct bpf_map *map, void *key) | |
273 | { | |
274 | return ERR_PTR(-EOPNOTSUPP); | |
275 | } | |
276 | ||
277 | static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, | |
278 | struct sock **psk) | |
279 | { | |
280 | struct sock *sk; | |
45a4521d | 281 | int err = 0; |
604326b4 DB |
282 | |
283 | raw_spin_lock_bh(&stab->lock); | |
284 | sk = *psk; | |
285 | if (!sk_test || sk_test == sk) | |
45a4521d JF |
286 | sk = xchg(psk, NULL); |
287 | ||
288 | if (likely(sk)) | |
289 | sock_map_unref(sk, psk); | |
290 | else | |
291 | err = -EINVAL; | |
292 | ||
604326b4 | 293 | raw_spin_unlock_bh(&stab->lock); |
45a4521d | 294 | return err; |
604326b4 DB |
295 | } |
296 | ||
297 | static 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 | ||
305 | static 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 | ||
318 | static 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 | ||
333 | static 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); | |
0e858739 | 337 | struct inet_connection_sock *icsk = inet_csk(sk); |
604326b4 DB |
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; | |
0e858739 JF |
348 | if (unlikely(icsk->icsk_ulp_data)) |
349 | return -EINVAL; | |
604326b4 DB |
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; | |
378 | out_unlock: | |
379 | raw_spin_unlock_bh(&stab->lock); | |
380 | if (psock) | |
381 | sk_psock_put(sk, psock); | |
382 | out_free: | |
383 | sk_psock_free_link(link); | |
384 | return ret; | |
385 | } | |
386 | ||
387 | static 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 | ||
393 | static 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 | ||
399 | static 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); | |
425 | out: | |
426 | fput(sock->file); | |
427 | return ret; | |
428 | } | |
429 | ||
430 | BPF_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 | ||
442 | const 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 | ||
453 | BPF_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 | ||
467 | const 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 | ||
477 | BPF_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 | ||
489 | const 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 | ||
499 | const 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 | ||
510 | struct 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 | ||
518 | struct bpf_htab_bucket { | |
519 | struct hlist_head head; | |
520 | raw_spinlock_t lock; | |
521 | }; | |
522 | ||
523 | struct 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 | ||
532 | static inline u32 sock_hash_bucket_hash(const void *key, u32 len) | |
533 | { | |
534 | return jhash(key, len, 0); | |
535 | } | |
536 | ||
537 | static 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 | ||
543 | static struct bpf_htab_elem * | |
544 | sock_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 | ||
558 | static 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 | ||
574 | static 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 | ||
581 | static 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 | ||
606 | static 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 | ||
629 | static 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 | ||
655 | static 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 | u32 key_size = map->key_size, hash; | |
660 | struct bpf_htab_elem *elem, *elem_new; | |
661 | struct bpf_htab_bucket *bucket; | |
662 | struct sk_psock_link *link; | |
663 | struct sk_psock *psock; | |
664 | int ret; | |
665 | ||
666 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
667 | if (unlikely(flags > BPF_EXIST)) | |
668 | return -EINVAL; | |
669 | ||
670 | link = sk_psock_init_link(); | |
671 | if (!link) | |
672 | return -ENOMEM; | |
673 | ||
674 | ret = sock_map_link(map, &htab->progs, sk); | |
675 | if (ret < 0) | |
676 | goto out_free; | |
677 | ||
678 | psock = sk_psock(sk); | |
679 | WARN_ON_ONCE(!psock); | |
680 | ||
681 | hash = sock_hash_bucket_hash(key, key_size); | |
682 | bucket = sock_hash_select_bucket(htab, hash); | |
683 | ||
684 | raw_spin_lock_bh(&bucket->lock); | |
685 | elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); | |
686 | if (elem && flags == BPF_NOEXIST) { | |
687 | ret = -EEXIST; | |
688 | goto out_unlock; | |
689 | } else if (!elem && flags == BPF_EXIST) { | |
690 | ret = -ENOENT; | |
691 | goto out_unlock; | |
692 | } | |
693 | ||
694 | elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem); | |
695 | if (IS_ERR(elem_new)) { | |
696 | ret = PTR_ERR(elem_new); | |
697 | goto out_unlock; | |
698 | } | |
699 | ||
700 | sock_map_add_link(psock, link, map, elem_new); | |
701 | /* Add new element to the head of the list, so that | |
702 | * concurrent search will find it before old elem. | |
703 | */ | |
704 | hlist_add_head_rcu(&elem_new->node, &bucket->head); | |
705 | if (elem) { | |
706 | hlist_del_rcu(&elem->node); | |
707 | sock_map_unref(elem->sk, elem); | |
708 | sock_hash_free_elem(htab, elem); | |
709 | } | |
710 | raw_spin_unlock_bh(&bucket->lock); | |
711 | return 0; | |
712 | out_unlock: | |
713 | raw_spin_unlock_bh(&bucket->lock); | |
714 | sk_psock_put(sk, psock); | |
715 | out_free: | |
716 | sk_psock_free_link(link); | |
717 | return ret; | |
718 | } | |
719 | ||
720 | static int sock_hash_update_elem(struct bpf_map *map, void *key, | |
721 | void *value, u64 flags) | |
722 | { | |
723 | u32 ufd = *(u32 *)value; | |
724 | struct socket *sock; | |
725 | struct sock *sk; | |
726 | int ret; | |
727 | ||
728 | sock = sockfd_lookup(ufd, &ret); | |
729 | if (!sock) | |
730 | return ret; | |
731 | sk = sock->sk; | |
732 | if (!sk) { | |
733 | ret = -EINVAL; | |
734 | goto out; | |
735 | } | |
736 | if (!sock_map_sk_is_suitable(sk) || | |
737 | sk->sk_state != TCP_ESTABLISHED) { | |
738 | ret = -EOPNOTSUPP; | |
739 | goto out; | |
740 | } | |
741 | ||
742 | sock_map_sk_acquire(sk); | |
743 | ret = sock_hash_update_common(map, key, sk, flags); | |
744 | sock_map_sk_release(sk); | |
745 | out: | |
746 | fput(sock->file); | |
747 | return ret; | |
748 | } | |
749 | ||
750 | static int sock_hash_get_next_key(struct bpf_map *map, void *key, | |
751 | void *key_next) | |
752 | { | |
753 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
754 | struct bpf_htab_elem *elem, *elem_next; | |
755 | u32 hash, key_size = map->key_size; | |
756 | struct hlist_head *head; | |
757 | int i = 0; | |
758 | ||
759 | if (!key) | |
760 | goto find_first_elem; | |
761 | hash = sock_hash_bucket_hash(key, key_size); | |
762 | head = &sock_hash_select_bucket(htab, hash)->head; | |
763 | elem = sock_hash_lookup_elem_raw(head, hash, key, key_size); | |
764 | if (!elem) | |
765 | goto find_first_elem; | |
766 | ||
767 | elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&elem->node)), | |
768 | struct bpf_htab_elem, node); | |
769 | if (elem_next) { | |
770 | memcpy(key_next, elem_next->key, key_size); | |
771 | return 0; | |
772 | } | |
773 | ||
774 | i = hash & (htab->buckets_num - 1); | |
775 | i++; | |
776 | find_first_elem: | |
777 | for (; i < htab->buckets_num; i++) { | |
778 | head = &sock_hash_select_bucket(htab, i)->head; | |
779 | elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)), | |
780 | struct bpf_htab_elem, node); | |
781 | if (elem_next) { | |
782 | memcpy(key_next, elem_next->key, key_size); | |
783 | return 0; | |
784 | } | |
785 | } | |
786 | ||
787 | return -ENOENT; | |
788 | } | |
789 | ||
790 | static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) | |
791 | { | |
792 | struct bpf_htab *htab; | |
793 | int i, err; | |
794 | u64 cost; | |
795 | ||
796 | if (!capable(CAP_NET_ADMIN)) | |
797 | return ERR_PTR(-EPERM); | |
798 | if (attr->max_entries == 0 || | |
799 | attr->key_size == 0 || | |
800 | attr->value_size != 4 || | |
801 | attr->map_flags & ~SOCK_CREATE_FLAG_MASK) | |
802 | return ERR_PTR(-EINVAL); | |
803 | if (attr->key_size > MAX_BPF_STACK) | |
804 | return ERR_PTR(-E2BIG); | |
805 | ||
806 | htab = kzalloc(sizeof(*htab), GFP_USER); | |
807 | if (!htab) | |
808 | return ERR_PTR(-ENOMEM); | |
809 | ||
810 | bpf_map_init_from_attr(&htab->map, attr); | |
811 | ||
812 | htab->buckets_num = roundup_pow_of_two(htab->map.max_entries); | |
813 | htab->elem_size = sizeof(struct bpf_htab_elem) + | |
814 | round_up(htab->map.key_size, 8); | |
815 | if (htab->buckets_num == 0 || | |
816 | htab->buckets_num > U32_MAX / sizeof(struct bpf_htab_bucket)) { | |
817 | err = -EINVAL; | |
818 | goto free_htab; | |
819 | } | |
820 | ||
821 | cost = (u64) htab->buckets_num * sizeof(struct bpf_htab_bucket) + | |
822 | (u64) htab->elem_size * htab->map.max_entries; | |
823 | if (cost >= U32_MAX - PAGE_SIZE) { | |
824 | err = -EINVAL; | |
825 | goto free_htab; | |
826 | } | |
827 | ||
828 | htab->buckets = bpf_map_area_alloc(htab->buckets_num * | |
829 | sizeof(struct bpf_htab_bucket), | |
830 | htab->map.numa_node); | |
831 | if (!htab->buckets) { | |
832 | err = -ENOMEM; | |
833 | goto free_htab; | |
834 | } | |
835 | ||
836 | for (i = 0; i < htab->buckets_num; i++) { | |
837 | INIT_HLIST_HEAD(&htab->buckets[i].head); | |
838 | raw_spin_lock_init(&htab->buckets[i].lock); | |
839 | } | |
840 | ||
841 | return &htab->map; | |
842 | free_htab: | |
843 | kfree(htab); | |
844 | return ERR_PTR(err); | |
845 | } | |
846 | ||
847 | static void sock_hash_free(struct bpf_map *map) | |
848 | { | |
849 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
850 | struct bpf_htab_bucket *bucket; | |
851 | struct bpf_htab_elem *elem; | |
852 | struct hlist_node *node; | |
853 | int i; | |
854 | ||
855 | synchronize_rcu(); | |
856 | rcu_read_lock(); | |
857 | for (i = 0; i < htab->buckets_num; i++) { | |
858 | bucket = sock_hash_select_bucket(htab, i); | |
859 | raw_spin_lock_bh(&bucket->lock); | |
860 | hlist_for_each_entry_safe(elem, node, &bucket->head, node) { | |
861 | hlist_del_rcu(&elem->node); | |
862 | sock_map_unref(elem->sk, elem); | |
863 | } | |
864 | raw_spin_unlock_bh(&bucket->lock); | |
865 | } | |
866 | rcu_read_unlock(); | |
867 | ||
868 | bpf_map_area_free(htab->buckets); | |
869 | kfree(htab); | |
870 | } | |
871 | ||
872 | static void sock_hash_release_progs(struct bpf_map *map) | |
873 | { | |
874 | psock_progs_drop(&container_of(map, struct bpf_htab, map)->progs); | |
875 | } | |
876 | ||
877 | BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops, | |
878 | struct bpf_map *, map, void *, key, u64, flags) | |
879 | { | |
880 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
881 | ||
882 | if (likely(sock_map_sk_is_suitable(sops->sk) && | |
883 | sock_map_op_okay(sops))) | |
884 | return sock_hash_update_common(map, key, sops->sk, flags); | |
885 | return -EOPNOTSUPP; | |
886 | } | |
887 | ||
888 | const struct bpf_func_proto bpf_sock_hash_update_proto = { | |
889 | .func = bpf_sock_hash_update, | |
890 | .gpl_only = false, | |
891 | .pkt_access = true, | |
892 | .ret_type = RET_INTEGER, | |
893 | .arg1_type = ARG_PTR_TO_CTX, | |
894 | .arg2_type = ARG_CONST_MAP_PTR, | |
895 | .arg3_type = ARG_PTR_TO_MAP_KEY, | |
896 | .arg4_type = ARG_ANYTHING, | |
897 | }; | |
898 | ||
899 | BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb, | |
900 | struct bpf_map *, map, void *, key, u64, flags) | |
901 | { | |
902 | struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); | |
903 | ||
904 | if (unlikely(flags & ~(BPF_F_INGRESS))) | |
905 | return SK_DROP; | |
906 | tcb->bpf.flags = flags; | |
907 | tcb->bpf.sk_redir = __sock_hash_lookup_elem(map, key); | |
908 | if (!tcb->bpf.sk_redir) | |
909 | return SK_DROP; | |
910 | return SK_PASS; | |
911 | } | |
912 | ||
913 | const struct bpf_func_proto bpf_sk_redirect_hash_proto = { | |
914 | .func = bpf_sk_redirect_hash, | |
915 | .gpl_only = false, | |
916 | .ret_type = RET_INTEGER, | |
917 | .arg1_type = ARG_PTR_TO_CTX, | |
918 | .arg2_type = ARG_CONST_MAP_PTR, | |
919 | .arg3_type = ARG_PTR_TO_MAP_KEY, | |
920 | .arg4_type = ARG_ANYTHING, | |
921 | }; | |
922 | ||
923 | BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg, | |
924 | struct bpf_map *, map, void *, key, u64, flags) | |
925 | { | |
926 | if (unlikely(flags & ~(BPF_F_INGRESS))) | |
927 | return SK_DROP; | |
928 | msg->flags = flags; | |
929 | msg->sk_redir = __sock_hash_lookup_elem(map, key); | |
930 | if (!msg->sk_redir) | |
931 | return SK_DROP; | |
932 | return SK_PASS; | |
933 | } | |
934 | ||
935 | const struct bpf_func_proto bpf_msg_redirect_hash_proto = { | |
936 | .func = bpf_msg_redirect_hash, | |
937 | .gpl_only = false, | |
938 | .ret_type = RET_INTEGER, | |
939 | .arg1_type = ARG_PTR_TO_CTX, | |
940 | .arg2_type = ARG_CONST_MAP_PTR, | |
941 | .arg3_type = ARG_PTR_TO_MAP_KEY, | |
942 | .arg4_type = ARG_ANYTHING, | |
943 | }; | |
944 | ||
945 | const struct bpf_map_ops sock_hash_ops = { | |
946 | .map_alloc = sock_hash_alloc, | |
947 | .map_free = sock_hash_free, | |
948 | .map_get_next_key = sock_hash_get_next_key, | |
949 | .map_update_elem = sock_hash_update_elem, | |
950 | .map_delete_elem = sock_hash_delete_elem, | |
951 | .map_lookup_elem = sock_map_lookup, | |
952 | .map_release_uref = sock_hash_release_progs, | |
953 | .map_check_btf = map_check_no_btf, | |
954 | }; | |
955 | ||
956 | static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) | |
957 | { | |
958 | switch (map->map_type) { | |
959 | case BPF_MAP_TYPE_SOCKMAP: | |
960 | return &container_of(map, struct bpf_stab, map)->progs; | |
961 | case BPF_MAP_TYPE_SOCKHASH: | |
962 | return &container_of(map, struct bpf_htab, map)->progs; | |
963 | default: | |
964 | break; | |
965 | } | |
966 | ||
967 | return NULL; | |
968 | } | |
969 | ||
970 | int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, | |
971 | u32 which) | |
972 | { | |
973 | struct sk_psock_progs *progs = sock_map_progs(map); | |
974 | ||
975 | if (!progs) | |
976 | return -EOPNOTSUPP; | |
977 | ||
978 | switch (which) { | |
979 | case BPF_SK_MSG_VERDICT: | |
980 | psock_set_prog(&progs->msg_parser, prog); | |
981 | break; | |
982 | case BPF_SK_SKB_STREAM_PARSER: | |
983 | psock_set_prog(&progs->skb_parser, prog); | |
984 | break; | |
985 | case BPF_SK_SKB_STREAM_VERDICT: | |
986 | psock_set_prog(&progs->skb_verdict, prog); | |
987 | break; | |
988 | default: | |
989 | return -EOPNOTSUPP; | |
990 | } | |
991 | ||
992 | return 0; | |
993 | } | |
994 | ||
995 | void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link) | |
996 | { | |
997 | switch (link->map->map_type) { | |
998 | case BPF_MAP_TYPE_SOCKMAP: | |
999 | return sock_map_delete_from_link(link->map, sk, | |
1000 | link->link_raw); | |
1001 | case BPF_MAP_TYPE_SOCKHASH: | |
1002 | return sock_hash_delete_from_link(link->map, sk, | |
1003 | link->link_raw); | |
1004 | default: | |
1005 | break; | |
1006 | } | |
1007 | } |