Commit | Line | Data |
---|---|---|
604326b4 DB |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */ | |
3 | ||
4 | #include <linux/skmsg.h> | |
5 | #include <linux/skbuff.h> | |
6 | #include <linux/scatterlist.h> | |
7 | ||
8 | #include <net/sock.h> | |
9 | #include <net/tcp.h> | |
10 | ||
11 | static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce) | |
12 | { | |
13 | if (msg->sg.end > msg->sg.start && | |
14 | elem_first_coalesce < msg->sg.end) | |
15 | return true; | |
16 | ||
17 | if (msg->sg.end < msg->sg.start && | |
18 | (elem_first_coalesce > msg->sg.start || | |
19 | elem_first_coalesce < msg->sg.end)) | |
20 | return true; | |
21 | ||
22 | return false; | |
23 | } | |
24 | ||
25 | int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len, | |
26 | int elem_first_coalesce) | |
27 | { | |
28 | struct page_frag *pfrag = sk_page_frag(sk); | |
29 | int ret = 0; | |
30 | ||
31 | len -= msg->sg.size; | |
32 | while (len > 0) { | |
33 | struct scatterlist *sge; | |
34 | u32 orig_offset; | |
35 | int use, i; | |
36 | ||
37 | if (!sk_page_frag_refill(sk, pfrag)) | |
38 | return -ENOMEM; | |
39 | ||
40 | orig_offset = pfrag->offset; | |
41 | use = min_t(int, len, pfrag->size - orig_offset); | |
42 | if (!sk_wmem_schedule(sk, use)) | |
43 | return -ENOMEM; | |
44 | ||
45 | i = msg->sg.end; | |
46 | sk_msg_iter_var_prev(i); | |
47 | sge = &msg->sg.data[i]; | |
48 | ||
49 | if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) && | |
50 | sg_page(sge) == pfrag->page && | |
51 | sge->offset + sge->length == orig_offset) { | |
52 | sge->length += use; | |
53 | } else { | |
54 | if (sk_msg_full(msg)) { | |
55 | ret = -ENOSPC; | |
56 | break; | |
57 | } | |
58 | ||
59 | sge = &msg->sg.data[msg->sg.end]; | |
60 | sg_unmark_end(sge); | |
61 | sg_set_page(sge, pfrag->page, use, orig_offset); | |
62 | get_page(pfrag->page); | |
63 | sk_msg_iter_next(msg, end); | |
64 | } | |
65 | ||
66 | sk_mem_charge(sk, use); | |
67 | msg->sg.size += use; | |
68 | pfrag->offset += use; | |
69 | len -= use; | |
70 | } | |
71 | ||
72 | return ret; | |
73 | } | |
74 | EXPORT_SYMBOL_GPL(sk_msg_alloc); | |
75 | ||
d829e9c4 DB |
76 | int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src, |
77 | u32 off, u32 len) | |
78 | { | |
79 | int i = src->sg.start; | |
80 | struct scatterlist *sge = sk_msg_elem(src, i); | |
81 | u32 sge_len, sge_off; | |
82 | ||
83 | if (sk_msg_full(dst)) | |
84 | return -ENOSPC; | |
85 | ||
86 | while (off) { | |
87 | if (sge->length > off) | |
88 | break; | |
89 | off -= sge->length; | |
90 | sk_msg_iter_var_next(i); | |
91 | if (i == src->sg.end && off) | |
92 | return -ENOSPC; | |
93 | sge = sk_msg_elem(src, i); | |
94 | } | |
95 | ||
96 | while (len) { | |
97 | sge_len = sge->length - off; | |
98 | sge_off = sge->offset + off; | |
99 | if (sge_len > len) | |
100 | sge_len = len; | |
101 | off = 0; | |
102 | len -= sge_len; | |
103 | sk_msg_page_add(dst, sg_page(sge), sge_len, sge_off); | |
104 | sk_mem_charge(sk, sge_len); | |
105 | sk_msg_iter_var_next(i); | |
106 | if (i == src->sg.end && len) | |
107 | return -ENOSPC; | |
108 | sge = sk_msg_elem(src, i); | |
109 | } | |
110 | ||
111 | return 0; | |
112 | } | |
113 | EXPORT_SYMBOL_GPL(sk_msg_clone); | |
114 | ||
604326b4 DB |
115 | void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes) |
116 | { | |
117 | int i = msg->sg.start; | |
118 | ||
119 | do { | |
120 | struct scatterlist *sge = sk_msg_elem(msg, i); | |
121 | ||
122 | if (bytes < sge->length) { | |
123 | sge->length -= bytes; | |
124 | sge->offset += bytes; | |
125 | sk_mem_uncharge(sk, bytes); | |
126 | break; | |
127 | } | |
128 | ||
129 | sk_mem_uncharge(sk, sge->length); | |
130 | bytes -= sge->length; | |
131 | sge->length = 0; | |
132 | sge->offset = 0; | |
133 | sk_msg_iter_var_next(i); | |
134 | } while (bytes && i != msg->sg.end); | |
135 | msg->sg.start = i; | |
136 | } | |
137 | EXPORT_SYMBOL_GPL(sk_msg_return_zero); | |
138 | ||
139 | void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes) | |
140 | { | |
141 | int i = msg->sg.start; | |
142 | ||
143 | do { | |
144 | struct scatterlist *sge = &msg->sg.data[i]; | |
145 | int uncharge = (bytes < sge->length) ? bytes : sge->length; | |
146 | ||
147 | sk_mem_uncharge(sk, uncharge); | |
148 | bytes -= uncharge; | |
149 | sk_msg_iter_var_next(i); | |
150 | } while (i != msg->sg.end); | |
151 | } | |
152 | EXPORT_SYMBOL_GPL(sk_msg_return); | |
153 | ||
154 | static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i, | |
155 | bool charge) | |
156 | { | |
157 | struct scatterlist *sge = sk_msg_elem(msg, i); | |
158 | u32 len = sge->length; | |
159 | ||
160 | if (charge) | |
161 | sk_mem_uncharge(sk, len); | |
162 | if (!msg->skb) | |
163 | put_page(sg_page(sge)); | |
164 | memset(sge, 0, sizeof(*sge)); | |
165 | return len; | |
166 | } | |
167 | ||
168 | static int __sk_msg_free(struct sock *sk, struct sk_msg *msg, u32 i, | |
169 | bool charge) | |
170 | { | |
171 | struct scatterlist *sge = sk_msg_elem(msg, i); | |
172 | int freed = 0; | |
173 | ||
174 | while (msg->sg.size) { | |
175 | msg->sg.size -= sge->length; | |
176 | freed += sk_msg_free_elem(sk, msg, i, charge); | |
177 | sk_msg_iter_var_next(i); | |
178 | sk_msg_check_to_free(msg, i, msg->sg.size); | |
179 | sge = sk_msg_elem(msg, i); | |
180 | } | |
181 | if (msg->skb) | |
182 | consume_skb(msg->skb); | |
183 | sk_msg_init(msg); | |
184 | return freed; | |
185 | } | |
186 | ||
187 | int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg) | |
188 | { | |
189 | return __sk_msg_free(sk, msg, msg->sg.start, false); | |
190 | } | |
191 | EXPORT_SYMBOL_GPL(sk_msg_free_nocharge); | |
192 | ||
193 | int sk_msg_free(struct sock *sk, struct sk_msg *msg) | |
194 | { | |
195 | return __sk_msg_free(sk, msg, msg->sg.start, true); | |
196 | } | |
197 | EXPORT_SYMBOL_GPL(sk_msg_free); | |
198 | ||
199 | static void __sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, | |
200 | u32 bytes, bool charge) | |
201 | { | |
202 | struct scatterlist *sge; | |
203 | u32 i = msg->sg.start; | |
204 | ||
205 | while (bytes) { | |
206 | sge = sk_msg_elem(msg, i); | |
207 | if (!sge->length) | |
208 | break; | |
209 | if (bytes < sge->length) { | |
210 | if (charge) | |
211 | sk_mem_uncharge(sk, bytes); | |
212 | sge->length -= bytes; | |
213 | sge->offset += bytes; | |
214 | msg->sg.size -= bytes; | |
215 | break; | |
216 | } | |
217 | ||
218 | msg->sg.size -= sge->length; | |
219 | bytes -= sge->length; | |
220 | sk_msg_free_elem(sk, msg, i, charge); | |
221 | sk_msg_iter_var_next(i); | |
222 | sk_msg_check_to_free(msg, i, bytes); | |
223 | } | |
224 | msg->sg.start = i; | |
225 | } | |
226 | ||
227 | void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes) | |
228 | { | |
229 | __sk_msg_free_partial(sk, msg, bytes, true); | |
230 | } | |
231 | EXPORT_SYMBOL_GPL(sk_msg_free_partial); | |
232 | ||
233 | void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg, | |
234 | u32 bytes) | |
235 | { | |
236 | __sk_msg_free_partial(sk, msg, bytes, false); | |
237 | } | |
238 | ||
239 | void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len) | |
240 | { | |
241 | int trim = msg->sg.size - len; | |
242 | u32 i = msg->sg.end; | |
243 | ||
244 | if (trim <= 0) { | |
245 | WARN_ON(trim < 0); | |
246 | return; | |
247 | } | |
248 | ||
249 | sk_msg_iter_var_prev(i); | |
250 | msg->sg.size = len; | |
251 | while (msg->sg.data[i].length && | |
252 | trim >= msg->sg.data[i].length) { | |
253 | trim -= msg->sg.data[i].length; | |
254 | sk_msg_free_elem(sk, msg, i, true); | |
255 | sk_msg_iter_var_prev(i); | |
256 | if (!trim) | |
257 | goto out; | |
258 | } | |
259 | ||
260 | msg->sg.data[i].length -= trim; | |
261 | sk_mem_uncharge(sk, trim); | |
262 | out: | |
263 | /* If we trim data before curr pointer update copybreak and current | |
264 | * so that any future copy operations start at new copy location. | |
265 | * However trimed data that has not yet been used in a copy op | |
266 | * does not require an update. | |
267 | */ | |
268 | if (msg->sg.curr >= i) { | |
269 | msg->sg.curr = i; | |
270 | msg->sg.copybreak = msg->sg.data[i].length; | |
271 | } | |
272 | sk_msg_iter_var_next(i); | |
273 | msg->sg.end = i; | |
274 | } | |
275 | EXPORT_SYMBOL_GPL(sk_msg_trim); | |
276 | ||
277 | int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from, | |
278 | struct sk_msg *msg, u32 bytes) | |
279 | { | |
280 | int i, maxpages, ret = 0, num_elems = sk_msg_elem_used(msg); | |
281 | const int to_max_pages = MAX_MSG_FRAGS; | |
282 | struct page *pages[MAX_MSG_FRAGS]; | |
283 | ssize_t orig, copied, use, offset; | |
284 | ||
285 | orig = msg->sg.size; | |
286 | while (bytes > 0) { | |
287 | i = 0; | |
288 | maxpages = to_max_pages - num_elems; | |
289 | if (maxpages == 0) { | |
290 | ret = -EFAULT; | |
291 | goto out; | |
292 | } | |
293 | ||
294 | copied = iov_iter_get_pages(from, pages, bytes, maxpages, | |
295 | &offset); | |
296 | if (copied <= 0) { | |
297 | ret = -EFAULT; | |
298 | goto out; | |
299 | } | |
300 | ||
301 | iov_iter_advance(from, copied); | |
302 | bytes -= copied; | |
303 | msg->sg.size += copied; | |
304 | ||
305 | while (copied) { | |
306 | use = min_t(int, copied, PAGE_SIZE - offset); | |
307 | sg_set_page(&msg->sg.data[msg->sg.end], | |
308 | pages[i], use, offset); | |
309 | sg_unmark_end(&msg->sg.data[msg->sg.end]); | |
310 | sk_mem_charge(sk, use); | |
311 | ||
312 | offset = 0; | |
313 | copied -= use; | |
314 | sk_msg_iter_next(msg, end); | |
315 | num_elems++; | |
316 | i++; | |
317 | } | |
318 | /* When zerocopy is mixed with sk_msg_*copy* operations we | |
319 | * may have a copybreak set in this case clear and prefer | |
320 | * zerocopy remainder when possible. | |
321 | */ | |
322 | msg->sg.copybreak = 0; | |
323 | msg->sg.curr = msg->sg.end; | |
324 | } | |
325 | out: | |
326 | /* Revert iov_iter updates, msg will need to use 'trim' later if it | |
327 | * also needs to be cleared. | |
328 | */ | |
329 | if (ret) | |
330 | iov_iter_revert(from, msg->sg.size - orig); | |
331 | return ret; | |
332 | } | |
333 | EXPORT_SYMBOL_GPL(sk_msg_zerocopy_from_iter); | |
334 | ||
335 | int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from, | |
336 | struct sk_msg *msg, u32 bytes) | |
337 | { | |
338 | int ret = -ENOSPC, i = msg->sg.curr; | |
339 | struct scatterlist *sge; | |
340 | u32 copy, buf_size; | |
341 | void *to; | |
342 | ||
343 | do { | |
344 | sge = sk_msg_elem(msg, i); | |
345 | /* This is possible if a trim operation shrunk the buffer */ | |
346 | if (msg->sg.copybreak >= sge->length) { | |
347 | msg->sg.copybreak = 0; | |
348 | sk_msg_iter_var_next(i); | |
349 | if (i == msg->sg.end) | |
350 | break; | |
351 | sge = sk_msg_elem(msg, i); | |
352 | } | |
353 | ||
354 | buf_size = sge->length - msg->sg.copybreak; | |
355 | copy = (buf_size > bytes) ? bytes : buf_size; | |
356 | to = sg_virt(sge) + msg->sg.copybreak; | |
357 | msg->sg.copybreak += copy; | |
358 | if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) | |
359 | ret = copy_from_iter_nocache(to, copy, from); | |
360 | else | |
361 | ret = copy_from_iter(to, copy, from); | |
362 | if (ret != copy) { | |
363 | ret = -EFAULT; | |
364 | goto out; | |
365 | } | |
366 | bytes -= copy; | |
367 | if (!bytes) | |
368 | break; | |
369 | msg->sg.copybreak = 0; | |
370 | sk_msg_iter_var_next(i); | |
371 | } while (i != msg->sg.end); | |
372 | out: | |
373 | msg->sg.curr = i; | |
374 | return ret; | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter); | |
377 | ||
378 | static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) | |
379 | { | |
380 | struct sock *sk = psock->sk; | |
381 | int copied = 0, num_sge; | |
382 | struct sk_msg *msg; | |
383 | ||
384 | msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC); | |
385 | if (unlikely(!msg)) | |
386 | return -EAGAIN; | |
387 | if (!sk_rmem_schedule(sk, skb, skb->len)) { | |
388 | kfree(msg); | |
389 | return -EAGAIN; | |
390 | } | |
391 | ||
392 | sk_msg_init(msg); | |
393 | num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len); | |
394 | if (unlikely(num_sge < 0)) { | |
395 | kfree(msg); | |
396 | return num_sge; | |
397 | } | |
398 | ||
399 | sk_mem_charge(sk, skb->len); | |
400 | copied = skb->len; | |
401 | msg->sg.start = 0; | |
402 | msg->sg.end = num_sge == MAX_MSG_FRAGS ? 0 : num_sge; | |
403 | msg->skb = skb; | |
404 | ||
405 | sk_psock_queue_msg(psock, msg); | |
552de910 | 406 | sk_psock_data_ready(sk, psock); |
604326b4 DB |
407 | return copied; |
408 | } | |
409 | ||
410 | static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb, | |
411 | u32 off, u32 len, bool ingress) | |
412 | { | |
413 | if (ingress) | |
414 | return sk_psock_skb_ingress(psock, skb); | |
415 | else | |
416 | return skb_send_sock_locked(psock->sk, skb, off, len); | |
417 | } | |
418 | ||
419 | static void sk_psock_backlog(struct work_struct *work) | |
420 | { | |
421 | struct sk_psock *psock = container_of(work, struct sk_psock, work); | |
422 | struct sk_psock_work_state *state = &psock->work_state; | |
423 | struct sk_buff *skb; | |
424 | bool ingress; | |
425 | u32 len, off; | |
426 | int ret; | |
427 | ||
428 | /* Lock sock to avoid losing sk_socket during loop. */ | |
429 | lock_sock(psock->sk); | |
430 | if (state->skb) { | |
431 | skb = state->skb; | |
432 | len = state->len; | |
433 | off = state->off; | |
434 | state->skb = NULL; | |
435 | goto start; | |
436 | } | |
437 | ||
438 | while ((skb = skb_dequeue(&psock->ingress_skb))) { | |
439 | len = skb->len; | |
440 | off = 0; | |
441 | start: | |
442 | ingress = tcp_skb_bpf_ingress(skb); | |
443 | do { | |
444 | ret = -EIO; | |
445 | if (likely(psock->sk->sk_socket)) | |
446 | ret = sk_psock_handle_skb(psock, skb, off, | |
447 | len, ingress); | |
448 | if (ret <= 0) { | |
449 | if (ret == -EAGAIN) { | |
450 | state->skb = skb; | |
451 | state->len = len; | |
452 | state->off = off; | |
453 | goto end; | |
454 | } | |
455 | /* Hard errors break pipe and stop xmit. */ | |
456 | sk_psock_report_error(psock, ret ? -ret : EPIPE); | |
457 | sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED); | |
458 | kfree_skb(skb); | |
459 | goto end; | |
460 | } | |
461 | off += ret; | |
462 | len -= ret; | |
463 | } while (len); | |
464 | ||
465 | if (!ingress) | |
466 | kfree_skb(skb); | |
467 | } | |
468 | end: | |
469 | release_sock(psock->sk); | |
470 | } | |
471 | ||
472 | struct sk_psock *sk_psock_init(struct sock *sk, int node) | |
473 | { | |
474 | struct sk_psock *psock = kzalloc_node(sizeof(*psock), | |
475 | GFP_ATOMIC | __GFP_NOWARN, | |
476 | node); | |
477 | if (!psock) | |
478 | return NULL; | |
479 | ||
480 | psock->sk = sk; | |
481 | psock->eval = __SK_NONE; | |
482 | ||
483 | INIT_LIST_HEAD(&psock->link); | |
484 | spin_lock_init(&psock->link_lock); | |
485 | ||
486 | INIT_WORK(&psock->work, sk_psock_backlog); | |
487 | INIT_LIST_HEAD(&psock->ingress_msg); | |
488 | skb_queue_head_init(&psock->ingress_skb); | |
489 | ||
490 | sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED); | |
491 | refcount_set(&psock->refcnt, 1); | |
492 | ||
493 | rcu_assign_sk_user_data(sk, psock); | |
494 | sock_hold(sk); | |
495 | ||
496 | return psock; | |
497 | } | |
498 | EXPORT_SYMBOL_GPL(sk_psock_init); | |
499 | ||
500 | struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock) | |
501 | { | |
502 | struct sk_psock_link *link; | |
503 | ||
504 | spin_lock_bh(&psock->link_lock); | |
505 | link = list_first_entry_or_null(&psock->link, struct sk_psock_link, | |
506 | list); | |
507 | if (link) | |
508 | list_del(&link->list); | |
509 | spin_unlock_bh(&psock->link_lock); | |
510 | return link; | |
511 | } | |
512 | ||
513 | void __sk_psock_purge_ingress_msg(struct sk_psock *psock) | |
514 | { | |
515 | struct sk_msg *msg, *tmp; | |
516 | ||
517 | list_for_each_entry_safe(msg, tmp, &psock->ingress_msg, list) { | |
518 | list_del(&msg->list); | |
519 | sk_msg_free(psock->sk, msg); | |
520 | kfree(msg); | |
521 | } | |
522 | } | |
523 | ||
524 | static void sk_psock_zap_ingress(struct sk_psock *psock) | |
525 | { | |
526 | __skb_queue_purge(&psock->ingress_skb); | |
527 | __sk_psock_purge_ingress_msg(psock); | |
528 | } | |
529 | ||
530 | static void sk_psock_link_destroy(struct sk_psock *psock) | |
531 | { | |
532 | struct sk_psock_link *link, *tmp; | |
533 | ||
534 | list_for_each_entry_safe(link, tmp, &psock->link, list) { | |
535 | list_del(&link->list); | |
536 | sk_psock_free_link(link); | |
537 | } | |
538 | } | |
539 | ||
540 | static void sk_psock_destroy_deferred(struct work_struct *gc) | |
541 | { | |
542 | struct sk_psock *psock = container_of(gc, struct sk_psock, gc); | |
543 | ||
544 | /* No sk_callback_lock since already detached. */ | |
545 | if (psock->parser.enabled) | |
546 | strp_done(&psock->parser.strp); | |
547 | ||
548 | cancel_work_sync(&psock->work); | |
549 | ||
550 | psock_progs_drop(&psock->progs); | |
551 | ||
552 | sk_psock_link_destroy(psock); | |
553 | sk_psock_cork_free(psock); | |
554 | sk_psock_zap_ingress(psock); | |
555 | ||
556 | if (psock->sk_redir) | |
557 | sock_put(psock->sk_redir); | |
558 | sock_put(psock->sk); | |
559 | kfree(psock); | |
560 | } | |
561 | ||
562 | void sk_psock_destroy(struct rcu_head *rcu) | |
563 | { | |
564 | struct sk_psock *psock = container_of(rcu, struct sk_psock, rcu); | |
565 | ||
566 | INIT_WORK(&psock->gc, sk_psock_destroy_deferred); | |
567 | schedule_work(&psock->gc); | |
568 | } | |
569 | EXPORT_SYMBOL_GPL(sk_psock_destroy); | |
570 | ||
571 | void sk_psock_drop(struct sock *sk, struct sk_psock *psock) | |
572 | { | |
573 | rcu_assign_sk_user_data(sk, NULL); | |
574 | sk_psock_cork_free(psock); | |
575 | sk_psock_restore_proto(sk, psock); | |
576 | ||
577 | write_lock_bh(&sk->sk_callback_lock); | |
578 | if (psock->progs.skb_parser) | |
579 | sk_psock_stop_strp(sk, psock); | |
580 | write_unlock_bh(&sk->sk_callback_lock); | |
581 | sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED); | |
582 | ||
583 | call_rcu_sched(&psock->rcu, sk_psock_destroy); | |
584 | } | |
585 | EXPORT_SYMBOL_GPL(sk_psock_drop); | |
586 | ||
587 | static int sk_psock_map_verd(int verdict, bool redir) | |
588 | { | |
589 | switch (verdict) { | |
590 | case SK_PASS: | |
591 | return redir ? __SK_REDIRECT : __SK_PASS; | |
592 | case SK_DROP: | |
593 | default: | |
594 | break; | |
595 | } | |
596 | ||
597 | return __SK_DROP; | |
598 | } | |
599 | ||
600 | int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock, | |
601 | struct sk_msg *msg) | |
602 | { | |
603 | struct bpf_prog *prog; | |
604 | int ret; | |
605 | ||
606 | preempt_disable(); | |
607 | rcu_read_lock(); | |
608 | prog = READ_ONCE(psock->progs.msg_parser); | |
609 | if (unlikely(!prog)) { | |
610 | ret = __SK_PASS; | |
611 | goto out; | |
612 | } | |
613 | ||
614 | sk_msg_compute_data_pointers(msg); | |
615 | msg->sk = sk; | |
616 | ret = BPF_PROG_RUN(prog, msg); | |
617 | ret = sk_psock_map_verd(ret, msg->sk_redir); | |
618 | psock->apply_bytes = msg->apply_bytes; | |
619 | if (ret == __SK_REDIRECT) { | |
620 | if (psock->sk_redir) | |
621 | sock_put(psock->sk_redir); | |
622 | psock->sk_redir = msg->sk_redir; | |
623 | if (!psock->sk_redir) { | |
624 | ret = __SK_DROP; | |
625 | goto out; | |
626 | } | |
627 | sock_hold(psock->sk_redir); | |
628 | } | |
629 | out: | |
630 | rcu_read_unlock(); | |
631 | preempt_enable(); | |
632 | return ret; | |
633 | } | |
634 | EXPORT_SYMBOL_GPL(sk_psock_msg_verdict); | |
635 | ||
636 | static int sk_psock_bpf_run(struct sk_psock *psock, struct bpf_prog *prog, | |
637 | struct sk_buff *skb) | |
638 | { | |
639 | int ret; | |
640 | ||
641 | skb->sk = psock->sk; | |
642 | bpf_compute_data_end_sk_skb(skb); | |
643 | preempt_disable(); | |
644 | ret = BPF_PROG_RUN(prog, skb); | |
645 | preempt_enable(); | |
646 | /* strparser clones the skb before handing it to a upper layer, | |
647 | * meaning skb_orphan has been called. We NULL sk on the way out | |
648 | * to ensure we don't trigger a BUG_ON() in skb/sk operations | |
649 | * later and because we are not charging the memory of this skb | |
650 | * to any socket yet. | |
651 | */ | |
652 | skb->sk = NULL; | |
653 | return ret; | |
654 | } | |
655 | ||
656 | static struct sk_psock *sk_psock_from_strp(struct strparser *strp) | |
657 | { | |
658 | struct sk_psock_parser *parser; | |
659 | ||
660 | parser = container_of(strp, struct sk_psock_parser, strp); | |
661 | return container_of(parser, struct sk_psock, parser); | |
662 | } | |
663 | ||
664 | static void sk_psock_verdict_apply(struct sk_psock *psock, | |
665 | struct sk_buff *skb, int verdict) | |
666 | { | |
667 | struct sk_psock *psock_other; | |
668 | struct sock *sk_other; | |
669 | bool ingress; | |
670 | ||
671 | switch (verdict) { | |
51199405 JF |
672 | case __SK_PASS: |
673 | sk_other = psock->sk; | |
674 | if (sock_flag(sk_other, SOCK_DEAD) || | |
675 | !sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) { | |
676 | goto out_free; | |
677 | } | |
678 | if (atomic_read(&sk_other->sk_rmem_alloc) <= | |
679 | sk_other->sk_rcvbuf) { | |
680 | struct tcp_skb_cb *tcp = TCP_SKB_CB(skb); | |
681 | ||
682 | tcp->bpf.flags |= BPF_F_INGRESS; | |
683 | skb_queue_tail(&psock->ingress_skb, skb); | |
684 | schedule_work(&psock->work); | |
685 | break; | |
686 | } | |
687 | goto out_free; | |
604326b4 DB |
688 | case __SK_REDIRECT: |
689 | sk_other = tcp_skb_bpf_redirect_fetch(skb); | |
690 | if (unlikely(!sk_other)) | |
691 | goto out_free; | |
692 | psock_other = sk_psock(sk_other); | |
693 | if (!psock_other || sock_flag(sk_other, SOCK_DEAD) || | |
694 | !sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) | |
695 | goto out_free; | |
696 | ingress = tcp_skb_bpf_ingress(skb); | |
697 | if ((!ingress && sock_writeable(sk_other)) || | |
698 | (ingress && | |
699 | atomic_read(&sk_other->sk_rmem_alloc) <= | |
700 | sk_other->sk_rcvbuf)) { | |
701 | if (!ingress) | |
702 | skb_set_owner_w(skb, sk_other); | |
703 | skb_queue_tail(&psock_other->ingress_skb, skb); | |
704 | schedule_work(&psock_other->work); | |
705 | break; | |
706 | } | |
707 | /* fall-through */ | |
708 | case __SK_DROP: | |
709 | /* fall-through */ | |
710 | default: | |
711 | out_free: | |
712 | kfree_skb(skb); | |
713 | } | |
714 | } | |
715 | ||
716 | static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb) | |
717 | { | |
718 | struct sk_psock *psock = sk_psock_from_strp(strp); | |
719 | struct bpf_prog *prog; | |
720 | int ret = __SK_DROP; | |
721 | ||
722 | rcu_read_lock(); | |
723 | prog = READ_ONCE(psock->progs.skb_verdict); | |
724 | if (likely(prog)) { | |
725 | skb_orphan(skb); | |
726 | tcp_skb_bpf_redirect_clear(skb); | |
727 | ret = sk_psock_bpf_run(psock, prog, skb); | |
728 | ret = sk_psock_map_verd(ret, tcp_skb_bpf_redirect_fetch(skb)); | |
729 | } | |
730 | rcu_read_unlock(); | |
731 | sk_psock_verdict_apply(psock, skb, ret); | |
732 | } | |
733 | ||
734 | static int sk_psock_strp_read_done(struct strparser *strp, int err) | |
735 | { | |
736 | return err; | |
737 | } | |
738 | ||
739 | static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb) | |
740 | { | |
741 | struct sk_psock *psock = sk_psock_from_strp(strp); | |
742 | struct bpf_prog *prog; | |
743 | int ret = skb->len; | |
744 | ||
745 | rcu_read_lock(); | |
746 | prog = READ_ONCE(psock->progs.skb_parser); | |
747 | if (likely(prog)) | |
748 | ret = sk_psock_bpf_run(psock, prog, skb); | |
749 | rcu_read_unlock(); | |
750 | return ret; | |
751 | } | |
752 | ||
753 | /* Called with socket lock held. */ | |
552de910 | 754 | static void sk_psock_strp_data_ready(struct sock *sk) |
604326b4 DB |
755 | { |
756 | struct sk_psock *psock; | |
757 | ||
758 | rcu_read_lock(); | |
759 | psock = sk_psock(sk); | |
760 | if (likely(psock)) { | |
761 | write_lock_bh(&sk->sk_callback_lock); | |
762 | strp_data_ready(&psock->parser.strp); | |
763 | write_unlock_bh(&sk->sk_callback_lock); | |
764 | } | |
765 | rcu_read_unlock(); | |
766 | } | |
767 | ||
768 | static void sk_psock_write_space(struct sock *sk) | |
769 | { | |
770 | struct sk_psock *psock; | |
771 | void (*write_space)(struct sock *sk); | |
772 | ||
773 | rcu_read_lock(); | |
774 | psock = sk_psock(sk); | |
775 | if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))) | |
776 | schedule_work(&psock->work); | |
777 | write_space = psock->saved_write_space; | |
778 | rcu_read_unlock(); | |
779 | write_space(sk); | |
780 | } | |
781 | ||
782 | int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock) | |
783 | { | |
784 | static const struct strp_callbacks cb = { | |
785 | .rcv_msg = sk_psock_strp_read, | |
786 | .read_sock_done = sk_psock_strp_read_done, | |
787 | .parse_msg = sk_psock_strp_parse, | |
788 | }; | |
789 | ||
790 | psock->parser.enabled = false; | |
791 | return strp_init(&psock->parser.strp, sk, &cb); | |
792 | } | |
793 | ||
794 | void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock) | |
795 | { | |
796 | struct sk_psock_parser *parser = &psock->parser; | |
797 | ||
798 | if (parser->enabled) | |
799 | return; | |
800 | ||
801 | parser->saved_data_ready = sk->sk_data_ready; | |
552de910 | 802 | sk->sk_data_ready = sk_psock_strp_data_ready; |
604326b4 DB |
803 | sk->sk_write_space = sk_psock_write_space; |
804 | parser->enabled = true; | |
805 | } | |
806 | ||
807 | void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock) | |
808 | { | |
809 | struct sk_psock_parser *parser = &psock->parser; | |
810 | ||
811 | if (!parser->enabled) | |
812 | return; | |
813 | ||
814 | sk->sk_data_ready = parser->saved_data_ready; | |
815 | parser->saved_data_ready = NULL; | |
816 | strp_stop(&parser->strp); | |
817 | parser->enabled = false; | |
818 | } |