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1 | /* SPDX-License-Identifier: GPL-2.0 */ |
---|---|
2 | /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ |
3 | |
4 | #ifndef _LINUX_SKMSG_H |
5 | #define _LINUX_SKMSG_H |
6 | |
7 | #include <linux/bpf.h> |
8 | #include <linux/filter.h> |
9 | #include <linux/scatterlist.h> |
10 | #include <linux/skbuff.h> |
11 | |
12 | #include <net/sock.h> |
13 | #include <net/tcp.h> |
14 | #include <net/strparser.h> |
15 | |
16 | #define MAX_MSG_FRAGS MAX_SKB_FRAGS |
17 | #define NR_MSG_FRAG_IDS (MAX_MSG_FRAGS + 1) |
18 | |
19 | enum __sk_action { |
20 | __SK_DROP = 0, |
21 | __SK_PASS, |
22 | __SK_REDIRECT, |
23 | __SK_NONE, |
24 | }; |
25 | |
26 | struct sk_msg_sg { |
27 | u32 start; |
28 | u32 curr; |
29 | u32 end; |
30 | u32 size; |
31 | u32 copybreak; |
32 | DECLARE_BITMAP(copy, MAX_MSG_FRAGS + 2); |
33 | /* The extra two elements: |
34 | * 1) used for chaining the front and sections when the list becomes |
35 | * partitioned (e.g. end < start). The crypto APIs require the |
36 | * chaining; |
37 | * 2) to chain tailer SG entries after the message. |
38 | */ |
39 | struct scatterlist data[MAX_MSG_FRAGS + 2]; |
40 | }; |
41 | |
42 | /* UAPI in filter.c depends on struct sk_msg_sg being first element. */ |
43 | struct sk_msg { |
44 | struct sk_msg_sg sg; |
45 | void *data; |
46 | void *data_end; |
47 | u32 apply_bytes; |
48 | u32 cork_bytes; |
49 | u32 flags; |
50 | struct sk_buff *skb; |
51 | struct sock *sk_redir; |
52 | struct sock *sk; |
53 | struct list_head list; |
54 | }; |
55 | |
56 | struct sk_psock_progs { |
57 | struct bpf_prog *msg_parser; |
58 | struct bpf_prog *stream_parser; |
59 | struct bpf_prog *stream_verdict; |
60 | struct bpf_prog *skb_verdict; |
61 | }; |
62 | |
63 | enum sk_psock_state_bits { |
64 | SK_PSOCK_TX_ENABLED, |
65 | SK_PSOCK_RX_STRP_ENABLED, |
66 | }; |
67 | |
68 | struct sk_psock_link { |
69 | struct list_head list; |
70 | struct bpf_map *map; |
71 | void *link_raw; |
72 | }; |
73 | |
74 | struct sk_psock_work_state { |
75 | u32 len; |
76 | u32 off; |
77 | }; |
78 | |
79 | struct sk_psock { |
80 | struct sock *sk; |
81 | struct sock *sk_redir; |
82 | u32 apply_bytes; |
83 | u32 cork_bytes; |
84 | u32 eval; |
85 | bool redir_ingress; /* undefined if sk_redir is null */ |
86 | struct sk_msg *cork; |
87 | struct sk_psock_progs progs; |
88 | #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) |
89 | struct strparser strp; |
90 | #endif |
91 | struct sk_buff_head ingress_skb; |
92 | struct list_head ingress_msg; |
93 | spinlock_t ingress_lock; |
94 | unsigned long state; |
95 | struct list_head link; |
96 | spinlock_t link_lock; |
97 | refcount_t refcnt; |
98 | void (*saved_unhash)(struct sock *sk); |
99 | void (*saved_destroy)(struct sock *sk); |
100 | void (*saved_close)(struct sock *sk, long timeout); |
101 | void (*saved_write_space)(struct sock *sk); |
102 | void (*saved_data_ready)(struct sock *sk); |
103 | /* psock_update_sk_prot may be called with restore=false many times |
104 | * so the handler must be safe for this case. It will be called |
105 | * exactly once with restore=true when the psock is being destroyed |
106 | * and psock refcnt is zero, but before an RCU grace period. |
107 | */ |
108 | int (*psock_update_sk_prot)(struct sock *sk, struct sk_psock *psock, |
109 | bool restore); |
110 | struct proto *sk_proto; |
111 | struct mutex work_mutex; |
112 | struct sk_psock_work_state work_state; |
113 | struct delayed_work work; |
114 | struct sock *sk_pair; |
115 | struct rcu_work rwork; |
116 | }; |
117 | |
118 | int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len, |
119 | int elem_first_coalesce); |
120 | int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src, |
121 | u32 off, u32 len); |
122 | void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len); |
123 | int sk_msg_free(struct sock *sk, struct sk_msg *msg); |
124 | int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg); |
125 | void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes); |
126 | void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg, |
127 | u32 bytes); |
128 | |
129 | void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes); |
130 | void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes); |
131 | |
132 | int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from, |
133 | struct sk_msg *msg, u32 bytes); |
134 | int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from, |
135 | struct sk_msg *msg, u32 bytes); |
136 | int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, |
137 | int len, int flags); |
138 | bool sk_msg_is_readable(struct sock *sk); |
139 | |
140 | static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes) |
141 | { |
142 | WARN_ON(i == msg->sg.end && bytes); |
143 | } |
144 | |
145 | static inline void sk_msg_apply_bytes(struct sk_psock *psock, u32 bytes) |
146 | { |
147 | if (psock->apply_bytes) { |
148 | if (psock->apply_bytes < bytes) |
149 | psock->apply_bytes = 0; |
150 | else |
151 | psock->apply_bytes -= bytes; |
152 | } |
153 | } |
154 | |
155 | static inline u32 sk_msg_iter_dist(u32 start, u32 end) |
156 | { |
157 | return end >= start ? end - start : end + (NR_MSG_FRAG_IDS - start); |
158 | } |
159 | |
160 | #define sk_msg_iter_var_prev(var) \ |
161 | do { \ |
162 | if (var == 0) \ |
163 | var = NR_MSG_FRAG_IDS - 1; \ |
164 | else \ |
165 | var--; \ |
166 | } while (0) |
167 | |
168 | #define sk_msg_iter_var_next(var) \ |
169 | do { \ |
170 | var++; \ |
171 | if (var == NR_MSG_FRAG_IDS) \ |
172 | var = 0; \ |
173 | } while (0) |
174 | |
175 | #define sk_msg_iter_prev(msg, which) \ |
176 | sk_msg_iter_var_prev(msg->sg.which) |
177 | |
178 | #define sk_msg_iter_next(msg, which) \ |
179 | sk_msg_iter_var_next(msg->sg.which) |
180 | |
181 | static inline void sk_msg_init(struct sk_msg *msg) |
182 | { |
183 | BUILD_BUG_ON(ARRAY_SIZE(msg->sg.data) - 1 != NR_MSG_FRAG_IDS); |
184 | memset(msg, 0, sizeof(*msg)); |
185 | sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS); |
186 | } |
187 | |
188 | static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src, |
189 | int which, u32 size) |
190 | { |
191 | dst->sg.data[which] = src->sg.data[which]; |
192 | dst->sg.data[which].length = size; |
193 | dst->sg.size += size; |
194 | src->sg.size -= size; |
195 | src->sg.data[which].length -= size; |
196 | src->sg.data[which].offset += size; |
197 | } |
198 | |
199 | static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src) |
200 | { |
201 | memcpy(dst, src, sizeof(*src)); |
202 | sk_msg_init(src); |
203 | } |
204 | |
205 | static inline bool sk_msg_full(const struct sk_msg *msg) |
206 | { |
207 | return sk_msg_iter_dist(msg->sg.start, msg->sg.end) == MAX_MSG_FRAGS; |
208 | } |
209 | |
210 | static inline u32 sk_msg_elem_used(const struct sk_msg *msg) |
211 | { |
212 | return sk_msg_iter_dist(msg->sg.start, msg->sg.end); |
213 | } |
214 | |
215 | static inline struct scatterlist *sk_msg_elem(struct sk_msg *msg, int which) |
216 | { |
217 | return &msg->sg.data[which]; |
218 | } |
219 | |
220 | static inline struct scatterlist sk_msg_elem_cpy(struct sk_msg *msg, int which) |
221 | { |
222 | return msg->sg.data[which]; |
223 | } |
224 | |
225 | static inline struct page *sk_msg_page(struct sk_msg *msg, int which) |
226 | { |
227 | return sg_page(sk_msg_elem(msg, which)); |
228 | } |
229 | |
230 | static inline bool sk_msg_to_ingress(const struct sk_msg *msg) |
231 | { |
232 | return msg->flags & BPF_F_INGRESS; |
233 | } |
234 | |
235 | static inline void sk_msg_compute_data_pointers(struct sk_msg *msg) |
236 | { |
237 | struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start); |
238 | |
239 | if (test_bit(msg->sg.start, msg->sg.copy)) { |
240 | msg->data = NULL; |
241 | msg->data_end = NULL; |
242 | } else { |
243 | msg->data = sg_virt(sge); |
244 | msg->data_end = msg->data + sge->length; |
245 | } |
246 | } |
247 | |
248 | static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page, |
249 | u32 len, u32 offset) |
250 | { |
251 | struct scatterlist *sge; |
252 | |
253 | get_page(page); |
254 | sge = sk_msg_elem(msg, msg->sg.end); |
255 | sg_set_page(sge, page, len, offset); |
256 | sg_unmark_end(sge); |
257 | |
258 | __set_bit(msg->sg.end, msg->sg.copy); |
259 | msg->sg.size += len; |
260 | sk_msg_iter_next(msg, end); |
261 | } |
262 | |
263 | static inline void sk_msg_sg_copy(struct sk_msg *msg, u32 i, bool copy_state) |
264 | { |
265 | do { |
266 | if (copy_state) |
267 | __set_bit(i, msg->sg.copy); |
268 | else |
269 | __clear_bit(i, msg->sg.copy); |
270 | sk_msg_iter_var_next(i); |
271 | if (i == msg->sg.end) |
272 | break; |
273 | } while (1); |
274 | } |
275 | |
276 | static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start) |
277 | { |
278 | sk_msg_sg_copy(msg, start, true); |
279 | } |
280 | |
281 | static inline void sk_msg_sg_copy_clear(struct sk_msg *msg, u32 start) |
282 | { |
283 | sk_msg_sg_copy(msg, start, false); |
284 | } |
285 | |
286 | static inline struct sk_psock *sk_psock(const struct sock *sk) |
287 | { |
288 | return __rcu_dereference_sk_user_data_with_flags(sk, |
289 | SK_USER_DATA_PSOCK); |
290 | } |
291 | |
292 | static inline void sk_psock_set_state(struct sk_psock *psock, |
293 | enum sk_psock_state_bits bit) |
294 | { |
295 | set_bit(bit, &psock->state); |
296 | } |
297 | |
298 | static inline void sk_psock_clear_state(struct sk_psock *psock, |
299 | enum sk_psock_state_bits bit) |
300 | { |
301 | clear_bit(bit, &psock->state); |
302 | } |
303 | |
304 | static inline bool sk_psock_test_state(const struct sk_psock *psock, |
305 | enum sk_psock_state_bits bit) |
306 | { |
307 | return test_bit(bit, &psock->state); |
308 | } |
309 | |
310 | static inline void sock_drop(struct sock *sk, struct sk_buff *skb) |
311 | { |
312 | sk_drops_add(sk, skb); |
313 | kfree_skb(skb); |
314 | } |
315 | |
316 | static inline void sk_psock_queue_msg(struct sk_psock *psock, |
317 | struct sk_msg *msg) |
318 | { |
319 | spin_lock_bh(&psock->ingress_lock); |
320 | if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) |
321 | list_add_tail(&msg->list, &psock->ingress_msg); |
322 | else { |
323 | sk_msg_free(psock->sk, msg); |
324 | kfree(msg); |
325 | } |
326 | spin_unlock_bh(&psock->ingress_lock); |
327 | } |
328 | |
329 | static inline struct sk_msg *sk_psock_dequeue_msg(struct sk_psock *psock) |
330 | { |
331 | struct sk_msg *msg; |
332 | |
333 | spin_lock_bh(&psock->ingress_lock); |
334 | msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list); |
335 | if (msg) |
336 | list_del(&msg->list); |
337 | spin_unlock_bh(&psock->ingress_lock); |
338 | return msg; |
339 | } |
340 | |
341 | static inline struct sk_msg *sk_psock_peek_msg(struct sk_psock *psock) |
342 | { |
343 | struct sk_msg *msg; |
344 | |
345 | spin_lock_bh(&psock->ingress_lock); |
346 | msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list); |
347 | spin_unlock_bh(&psock->ingress_lock); |
348 | return msg; |
349 | } |
350 | |
351 | static inline struct sk_msg *sk_psock_next_msg(struct sk_psock *psock, |
352 | struct sk_msg *msg) |
353 | { |
354 | struct sk_msg *ret; |
355 | |
356 | spin_lock_bh(&psock->ingress_lock); |
357 | if (list_is_last(&msg->list, &psock->ingress_msg)) |
358 | ret = NULL; |
359 | else |
360 | ret = list_next_entry(msg, list); |
361 | spin_unlock_bh(&psock->ingress_lock); |
362 | return ret; |
363 | } |
364 | |
365 | static inline bool sk_psock_queue_empty(const struct sk_psock *psock) |
366 | { |
367 | return psock ? list_empty(&psock->ingress_msg) : true; |
368 | } |
369 | |
370 | static inline void kfree_sk_msg(struct sk_msg *msg) |
371 | { |
372 | if (msg->skb) |
373 | consume_skb(msg->skb); |
374 | kfree(msg); |
375 | } |
376 | |
377 | static inline void sk_psock_report_error(struct sk_psock *psock, int err) |
378 | { |
379 | struct sock *sk = psock->sk; |
380 | |
381 | sk->sk_err = err; |
382 | sk_error_report(sk); |
383 | } |
384 | |
385 | struct sk_psock *sk_psock_init(struct sock *sk, int node); |
386 | void sk_psock_stop(struct sk_psock *psock); |
387 | |
388 | #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) |
389 | int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock); |
390 | void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock); |
391 | void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock); |
392 | #else |
393 | static inline int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock) |
394 | { |
395 | return -EOPNOTSUPP; |
396 | } |
397 | |
398 | static inline void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock) |
399 | { |
400 | } |
401 | |
402 | static inline void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock) |
403 | { |
404 | } |
405 | #endif |
406 | |
407 | void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock); |
408 | void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock); |
409 | |
410 | int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock, |
411 | struct sk_msg *msg); |
412 | |
413 | static inline struct sk_psock_link *sk_psock_init_link(void) |
414 | { |
415 | return kzalloc(sizeof(struct sk_psock_link), |
416 | GFP_ATOMIC | __GFP_NOWARN); |
417 | } |
418 | |
419 | static inline void sk_psock_free_link(struct sk_psock_link *link) |
420 | { |
421 | kfree(link); |
422 | } |
423 | |
424 | struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock); |
425 | |
426 | static inline void sk_psock_cork_free(struct sk_psock *psock) |
427 | { |
428 | if (psock->cork) { |
429 | sk_msg_free(psock->sk, psock->cork); |
430 | kfree(psock->cork); |
431 | psock->cork = NULL; |
432 | } |
433 | } |
434 | |
435 | static inline void sk_psock_restore_proto(struct sock *sk, |
436 | struct sk_psock *psock) |
437 | { |
438 | if (psock->psock_update_sk_prot) |
439 | psock->psock_update_sk_prot(sk, psock, true); |
440 | } |
441 | |
442 | static inline struct sk_psock *sk_psock_get(struct sock *sk) |
443 | { |
444 | struct sk_psock *psock; |
445 | |
446 | rcu_read_lock(); |
447 | psock = sk_psock(sk); |
448 | if (psock && !refcount_inc_not_zero(&psock->refcnt)) |
449 | psock = NULL; |
450 | rcu_read_unlock(); |
451 | return psock; |
452 | } |
453 | |
454 | void sk_psock_drop(struct sock *sk, struct sk_psock *psock); |
455 | |
456 | static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock) |
457 | { |
458 | if (refcount_dec_and_test(&psock->refcnt)) |
459 | sk_psock_drop(sk, psock); |
460 | } |
461 | |
462 | static inline void sk_psock_data_ready(struct sock *sk, struct sk_psock *psock) |
463 | { |
464 | if (psock->saved_data_ready) |
465 | psock->saved_data_ready(sk); |
466 | else |
467 | sk->sk_data_ready(sk); |
468 | } |
469 | |
470 | static inline void psock_set_prog(struct bpf_prog **pprog, |
471 | struct bpf_prog *prog) |
472 | { |
473 | prog = xchg(pprog, prog); |
474 | if (prog) |
475 | bpf_prog_put(prog); |
476 | } |
477 | |
478 | static inline int psock_replace_prog(struct bpf_prog **pprog, |
479 | struct bpf_prog *prog, |
480 | struct bpf_prog *old) |
481 | { |
482 | if (cmpxchg(pprog, old, prog) != old) |
483 | return -ENOENT; |
484 | |
485 | if (old) |
486 | bpf_prog_put(old); |
487 | |
488 | return 0; |
489 | } |
490 | |
491 | static inline void psock_progs_drop(struct sk_psock_progs *progs) |
492 | { |
493 | psock_set_prog(&progs->msg_parser, NULL); |
494 | psock_set_prog(&progs->stream_parser, NULL); |
495 | psock_set_prog(&progs->stream_verdict, NULL); |
496 | psock_set_prog(&progs->skb_verdict, NULL); |
497 | } |
498 | |
499 | int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb); |
500 | |
501 | static inline bool sk_psock_strp_enabled(struct sk_psock *psock) |
502 | { |
503 | if (!psock) |
504 | return false; |
505 | return !!psock->saved_data_ready; |
506 | } |
507 | |
508 | #if IS_ENABLED(CONFIG_NET_SOCK_MSG) |
509 | |
510 | #define BPF_F_STRPARSER (1UL << 1) |
511 | |
512 | /* We only have two bits so far. */ |
513 | #define BPF_F_PTR_MASK ~(BPF_F_INGRESS | BPF_F_STRPARSER) |
514 | |
515 | static inline bool skb_bpf_strparser(const struct sk_buff *skb) |
516 | { |
517 | unsigned long sk_redir = skb->_sk_redir; |
518 | |
519 | return sk_redir & BPF_F_STRPARSER; |
520 | } |
521 | |
522 | static inline void skb_bpf_set_strparser(struct sk_buff *skb) |
523 | { |
524 | skb->_sk_redir |= BPF_F_STRPARSER; |
525 | } |
526 | |
527 | static inline bool skb_bpf_ingress(const struct sk_buff *skb) |
528 | { |
529 | unsigned long sk_redir = skb->_sk_redir; |
530 | |
531 | return sk_redir & BPF_F_INGRESS; |
532 | } |
533 | |
534 | static inline void skb_bpf_set_ingress(struct sk_buff *skb) |
535 | { |
536 | skb->_sk_redir |= BPF_F_INGRESS; |
537 | } |
538 | |
539 | static inline void skb_bpf_set_redir(struct sk_buff *skb, struct sock *sk_redir, |
540 | bool ingress) |
541 | { |
542 | skb->_sk_redir = (unsigned long)sk_redir; |
543 | if (ingress) |
544 | skb->_sk_redir |= BPF_F_INGRESS; |
545 | } |
546 | |
547 | static inline struct sock *skb_bpf_redirect_fetch(const struct sk_buff *skb) |
548 | { |
549 | unsigned long sk_redir = skb->_sk_redir; |
550 | |
551 | return (struct sock *)(sk_redir & BPF_F_PTR_MASK); |
552 | } |
553 | |
554 | static inline void skb_bpf_redirect_clear(struct sk_buff *skb) |
555 | { |
556 | skb->_sk_redir = 0; |
557 | } |
558 | #endif /* CONFIG_NET_SOCK_MSG */ |
559 | #endif /* _LINUX_SKMSG_H */ |
560 |
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