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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#include <net/tls.h>
11
12static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce)
13{
14 if (msg->sg.end > msg->sg.start &&
15 elem_first_coalesce < msg->sg.end)
16 return true;
17
18 if (msg->sg.end < msg->sg.start &&
19 (elem_first_coalesce > msg->sg.start ||
20 elem_first_coalesce < msg->sg.end))
21 return true;
22
23 return false;
24}
25
26int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
27 int elem_first_coalesce)
28{
29 struct page_frag *pfrag = sk_page_frag(sk);
30 int ret = 0;
31
32 len -= msg->sg.size;
33 while (len > 0) {
34 struct scatterlist *sge;
35 u32 orig_offset;
36 int use, i;
37
38 if (!sk_page_frag_refill(sk, pfrag))
39 return -ENOMEM;
40
41 orig_offset = pfrag->offset;
42 use = min_t(int, len, pfrag->size - orig_offset);
43 if (!sk_wmem_schedule(sk, use))
44 return -ENOMEM;
45
46 i = msg->sg.end;
47 sk_msg_iter_var_prev(i);
48 sge = &msg->sg.data[i];
49
50 if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) &&
51 sg_page(sge) == pfrag->page &&
52 sge->offset + sge->length == orig_offset) {
53 sge->length += use;
54 } else {
55 if (sk_msg_full(msg)) {
56 ret = -ENOSPC;
57 break;
58 }
59
60 sge = &msg->sg.data[msg->sg.end];
61 sg_unmark_end(sge);
62 sg_set_page(sge, pfrag->page, use, orig_offset);
63 get_page(pfrag->page);
64 sk_msg_iter_next(msg, end);
65 }
66
67 sk_mem_charge(sk, use);
68 msg->sg.size += use;
69 pfrag->offset += use;
70 len -= use;
71 }
72
73 return ret;
74}
75EXPORT_SYMBOL_GPL(sk_msg_alloc);
76
77int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src,
78 u32 off, u32 len)
79{
80 int i = src->sg.start;
81 struct scatterlist *sge = sk_msg_elem(src, i);
82 struct scatterlist *sgd = NULL;
83 u32 sge_len, sge_off;
84
85 while (off) {
86 if (sge->length > off)
87 break;
88 off -= sge->length;
89 sk_msg_iter_var_next(i);
90 if (i == src->sg.end && off)
91 return -ENOSPC;
92 sge = sk_msg_elem(src, i);
93 }
94
95 while (len) {
96 sge_len = sge->length - off;
97 if (sge_len > len)
98 sge_len = len;
99
100 if (dst->sg.end)
101 sgd = sk_msg_elem(dst, dst->sg.end - 1);
102
103 if (sgd &&
104 (sg_page(sge) == sg_page(sgd)) &&
105 (sg_virt(sge) + off == sg_virt(sgd) + sgd->length)) {
106 sgd->length += sge_len;
107 dst->sg.size += sge_len;
108 } else if (!sk_msg_full(dst)) {
109 sge_off = sge->offset + off;
110 sk_msg_page_add(dst, sg_page(sge), sge_len, sge_off);
111 } else {
112 return -ENOSPC;
113 }
114
115 off = 0;
116 len -= sge_len;
117 sk_mem_charge(sk, sge_len);
118 sk_msg_iter_var_next(i);
119 if (i == src->sg.end && len)
120 return -ENOSPC;
121 sge = sk_msg_elem(src, i);
122 }
123
124 return 0;
125}
126EXPORT_SYMBOL_GPL(sk_msg_clone);
127
128void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes)
129{
130 int i = msg->sg.start;
131
132 do {
133 struct scatterlist *sge = sk_msg_elem(msg, i);
134
135 if (bytes < sge->length) {
136 sge->length -= bytes;
137 sge->offset += bytes;
138 sk_mem_uncharge(sk, bytes);
139 break;
140 }
141
142 sk_mem_uncharge(sk, sge->length);
143 bytes -= sge->length;
144 sge->length = 0;
145 sge->offset = 0;
146 sk_msg_iter_var_next(i);
147 } while (bytes && i != msg->sg.end);
148 msg->sg.start = i;
149}
150EXPORT_SYMBOL_GPL(sk_msg_return_zero);
151
152void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes)
153{
154 int i = msg->sg.start;
155
156 do {
157 struct scatterlist *sge = &msg->sg.data[i];
158 int uncharge = (bytes < sge->length) ? bytes : sge->length;
159
160 sk_mem_uncharge(sk, uncharge);
161 bytes -= uncharge;
162 sk_msg_iter_var_next(i);
163 } while (i != msg->sg.end);
164}
165EXPORT_SYMBOL_GPL(sk_msg_return);
166
167static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
168 bool charge)
169{
170 struct scatterlist *sge = sk_msg_elem(msg, i);
171 u32 len = sge->length;
172
173 /* When the skb owns the memory we free it from consume_skb path. */
174 if (!msg->skb) {
175 if (charge)
176 sk_mem_uncharge(sk, len);
177 put_page(sg_page(sge));
178 }
179 memset(sge, 0, sizeof(*sge));
180 return len;
181}
182
183static int __sk_msg_free(struct sock *sk, struct sk_msg *msg, u32 i,
184 bool charge)
185{
186 struct scatterlist *sge = sk_msg_elem(msg, i);
187 int freed = 0;
188
189 while (msg->sg.size) {
190 msg->sg.size -= sge->length;
191 freed += sk_msg_free_elem(sk, msg, i, charge);
192 sk_msg_iter_var_next(i);
193 sk_msg_check_to_free(msg, i, msg->sg.size);
194 sge = sk_msg_elem(msg, i);
195 }
196 consume_skb(msg->skb);
197 sk_msg_init(msg);
198 return freed;
199}
200
201int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg)
202{
203 return __sk_msg_free(sk, msg, msg->sg.start, false);
204}
205EXPORT_SYMBOL_GPL(sk_msg_free_nocharge);
206
207int sk_msg_free(struct sock *sk, struct sk_msg *msg)
208{
209 return __sk_msg_free(sk, msg, msg->sg.start, true);
210}
211EXPORT_SYMBOL_GPL(sk_msg_free);
212
213static void __sk_msg_free_partial(struct sock *sk, struct sk_msg *msg,
214 u32 bytes, bool charge)
215{
216 struct scatterlist *sge;
217 u32 i = msg->sg.start;
218
219 while (bytes) {
220 sge = sk_msg_elem(msg, i);
221 if (!sge->length)
222 break;
223 if (bytes < sge->length) {
224 if (charge)
225 sk_mem_uncharge(sk, bytes);
226 sge->length -= bytes;
227 sge->offset += bytes;
228 msg->sg.size -= bytes;
229 break;
230 }
231
232 msg->sg.size -= sge->length;
233 bytes -= sge->length;
234 sk_msg_free_elem(sk, msg, i, charge);
235 sk_msg_iter_var_next(i);
236 sk_msg_check_to_free(msg, i, bytes);
237 }
238 msg->sg.start = i;
239}
240
241void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes)
242{
243 __sk_msg_free_partial(sk, msg, bytes, true);
244}
245EXPORT_SYMBOL_GPL(sk_msg_free_partial);
246
247void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
248 u32 bytes)
249{
250 __sk_msg_free_partial(sk, msg, bytes, false);
251}
252
253void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len)
254{
255 int trim = msg->sg.size - len;
256 u32 i = msg->sg.end;
257
258 if (trim <= 0) {
259 WARN_ON(trim < 0);
260 return;
261 }
262
263 sk_msg_iter_var_prev(i);
264 msg->sg.size = len;
265 while (msg->sg.data[i].length &&
266 trim >= msg->sg.data[i].length) {
267 trim -= msg->sg.data[i].length;
268 sk_msg_free_elem(sk, msg, i, true);
269 sk_msg_iter_var_prev(i);
270 if (!trim)
271 goto out;
272 }
273
274 msg->sg.data[i].length -= trim;
275 sk_mem_uncharge(sk, trim);
276 /* Adjust copybreak if it falls into the trimmed part of last buf */
277 if (msg->sg.curr == i && msg->sg.copybreak > msg->sg.data[i].length)
278 msg->sg.copybreak = msg->sg.data[i].length;
279out:
280 sk_msg_iter_var_next(i);
281 msg->sg.end = i;
282
283 /* If we trim data a full sg elem before curr pointer update
284 * copybreak and current so that any future copy operations
285 * start at new copy location.
286 * However trimed data that has not yet been used in a copy op
287 * does not require an update.
288 */
289 if (!msg->sg.size) {
290 msg->sg.curr = msg->sg.start;
291 msg->sg.copybreak = 0;
292 } else if (sk_msg_iter_dist(msg->sg.start, msg->sg.curr) >=
293 sk_msg_iter_dist(msg->sg.start, msg->sg.end)) {
294 sk_msg_iter_var_prev(i);
295 msg->sg.curr = i;
296 msg->sg.copybreak = msg->sg.data[i].length;
297 }
298}
299EXPORT_SYMBOL_GPL(sk_msg_trim);
300
301int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
302 struct sk_msg *msg, u32 bytes)
303{
304 int i, maxpages, ret = 0, num_elems = sk_msg_elem_used(msg);
305 const int to_max_pages = MAX_MSG_FRAGS;
306 struct page *pages[MAX_MSG_FRAGS];
307 ssize_t orig, copied, use, offset;
308
309 orig = msg->sg.size;
310 while (bytes > 0) {
311 i = 0;
312 maxpages = to_max_pages - num_elems;
313 if (maxpages == 0) {
314 ret = -EFAULT;
315 goto out;
316 }
317
318 copied = iov_iter_get_pages(from, pages, bytes, maxpages,
319 &offset);
320 if (copied <= 0) {
321 ret = -EFAULT;
322 goto out;
323 }
324
325 iov_iter_advance(from, copied);
326 bytes -= copied;
327 msg->sg.size += copied;
328
329 while (copied) {
330 use = min_t(int, copied, PAGE_SIZE - offset);
331 sg_set_page(&msg->sg.data[msg->sg.end],
332 pages[i], use, offset);
333 sg_unmark_end(&msg->sg.data[msg->sg.end]);
334 sk_mem_charge(sk, use);
335
336 offset = 0;
337 copied -= use;
338 sk_msg_iter_next(msg, end);
339 num_elems++;
340 i++;
341 }
342 /* When zerocopy is mixed with sk_msg_*copy* operations we
343 * may have a copybreak set in this case clear and prefer
344 * zerocopy remainder when possible.
345 */
346 msg->sg.copybreak = 0;
347 msg->sg.curr = msg->sg.end;
348 }
349out:
350 /* Revert iov_iter updates, msg will need to use 'trim' later if it
351 * also needs to be cleared.
352 */
353 if (ret)
354 iov_iter_revert(from, msg->sg.size - orig);
355 return ret;
356}
357EXPORT_SYMBOL_GPL(sk_msg_zerocopy_from_iter);
358
359int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
360 struct sk_msg *msg, u32 bytes)
361{
362 int ret = -ENOSPC, i = msg->sg.curr;
363 struct scatterlist *sge;
364 u32 copy, buf_size;
365 void *to;
366
367 do {
368 sge = sk_msg_elem(msg, i);
369 /* This is possible if a trim operation shrunk the buffer */
370 if (msg->sg.copybreak >= sge->length) {
371 msg->sg.copybreak = 0;
372 sk_msg_iter_var_next(i);
373 if (i == msg->sg.end)
374 break;
375 sge = sk_msg_elem(msg, i);
376 }
377
378 buf_size = sge->length - msg->sg.copybreak;
379 copy = (buf_size > bytes) ? bytes : buf_size;
380 to = sg_virt(sge) + msg->sg.copybreak;
381 msg->sg.copybreak += copy;
382 if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY)
383 ret = copy_from_iter_nocache(to, copy, from);
384 else
385 ret = copy_from_iter(to, copy, from);
386 if (ret != copy) {
387 ret = -EFAULT;
388 goto out;
389 }
390 bytes -= copy;
391 if (!bytes)
392 break;
393 msg->sg.copybreak = 0;
394 sk_msg_iter_var_next(i);
395 } while (i != msg->sg.end);
396out:
397 msg->sg.curr = i;
398 return ret;
399}
400EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter);
401
402/* Receive sk_msg from psock->ingress_msg to @msg. */
403int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
404 int len, int flags)
405{
406 struct iov_iter *iter = &msg->msg_iter;
407 int peek = flags & MSG_PEEK;
408 struct sk_msg *msg_rx;
409 int i, copied = 0;
410
411 msg_rx = sk_psock_peek_msg(psock);
412 while (copied != len) {
413 struct scatterlist *sge;
414
415 if (unlikely(!msg_rx))
416 break;
417
418 i = msg_rx->sg.start;
419 do {
420 struct page *page;
421 int copy;
422
423 sge = sk_msg_elem(msg_rx, i);
424 copy = sge->length;
425 page = sg_page(sge);
426 if (copied + copy > len)
427 copy = len - copied;
428 copy = copy_page_to_iter(page, sge->offset, copy, iter);
429 if (!copy)
430 return copied ? copied : -EFAULT;
431
432 copied += copy;
433 if (likely(!peek)) {
434 sge->offset += copy;
435 sge->length -= copy;
436 if (!msg_rx->skb)
437 sk_mem_uncharge(sk, copy);
438 msg_rx->sg.size -= copy;
439
440 if (!sge->length) {
441 sk_msg_iter_var_next(i);
442 if (!msg_rx->skb)
443 put_page(page);
444 }
445 } else {
446 /* Lets not optimize peek case if copy_page_to_iter
447 * didn't copy the entire length lets just break.
448 */
449 if (copy != sge->length)
450 return copied;
451 sk_msg_iter_var_next(i);
452 }
453
454 if (copied == len)
455 break;
456 } while (i != msg_rx->sg.end);
457
458 if (unlikely(peek)) {
459 msg_rx = sk_psock_next_msg(psock, msg_rx);
460 if (!msg_rx)
461 break;
462 continue;
463 }
464
465 msg_rx->sg.start = i;
466 if (!sge->length && msg_rx->sg.start == msg_rx->sg.end) {
467 msg_rx = sk_psock_dequeue_msg(psock);
468 kfree_sk_msg(msg_rx);
469 }
470 msg_rx = sk_psock_peek_msg(psock);
471 }
472
473 return copied;
474}
475EXPORT_SYMBOL_GPL(sk_msg_recvmsg);
476
477static struct sk_msg *sk_psock_create_ingress_msg(struct sock *sk,
478 struct sk_buff *skb)
479{
480 struct sk_msg *msg;
481
482 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
483 return NULL;
484
485 if (!sk_rmem_schedule(sk, skb, skb->truesize))
486 return NULL;
487
488 msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_KERNEL);
489 if (unlikely(!msg))
490 return NULL;
491
492 sk_msg_init(msg);
493 return msg;
494}
495
496static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb,
497 struct sk_psock *psock,
498 struct sock *sk,
499 struct sk_msg *msg)
500{
501 int num_sge, copied;
502
503 /* skb linearize may fail with ENOMEM, but lets simply try again
504 * later if this happens. Under memory pressure we don't want to
505 * drop the skb. We need to linearize the skb so that the mapping
506 * in skb_to_sgvec can not error.
507 */
508 if (skb_linearize(skb))
509 return -EAGAIN;
510 num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len);
511 if (unlikely(num_sge < 0))
512 return num_sge;
513
514 copied = skb->len;
515 msg->sg.start = 0;
516 msg->sg.size = copied;
517 msg->sg.end = num_sge;
518 msg->skb = skb;
519
520 sk_psock_queue_msg(psock, msg);
521 sk_psock_data_ready(sk, psock);
522 return copied;
523}
524
525static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb);
526
527static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
528{
529 struct sock *sk = psock->sk;
530 struct sk_msg *msg;
531 int err;
532
533 /* If we are receiving on the same sock skb->sk is already assigned,
534 * skip memory accounting and owner transition seeing it already set
535 * correctly.
536 */
537 if (unlikely(skb->sk == sk))
538 return sk_psock_skb_ingress_self(psock, skb);
539 msg = sk_psock_create_ingress_msg(sk, skb);
540 if (!msg)
541 return -EAGAIN;
542
543 /* This will transition ownership of the data from the socket where
544 * the BPF program was run initiating the redirect to the socket
545 * we will eventually receive this data on. The data will be released
546 * from skb_consume found in __tcp_bpf_recvmsg() after its been copied
547 * into user buffers.
548 */
549 skb_set_owner_r(skb, sk);
550 err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
551 if (err < 0)
552 kfree(msg);
553 return err;
554}
555
556/* Puts an skb on the ingress queue of the socket already assigned to the
557 * skb. In this case we do not need to check memory limits or skb_set_owner_r
558 * because the skb is already accounted for here.
559 */
560static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb)
561{
562 struct sk_msg *msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC);
563 struct sock *sk = psock->sk;
564 int err;
565
566 if (unlikely(!msg))
567 return -EAGAIN;
568 sk_msg_init(msg);
569 skb_set_owner_r(skb, sk);
570 err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
571 if (err < 0)
572 kfree(msg);
573 return err;
574}
575
576static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
577 u32 off, u32 len, bool ingress)
578{
579 if (!ingress) {
580 if (!sock_writeable(psock->sk))
581 return -EAGAIN;
582 return skb_send_sock(psock->sk, skb, off, len);
583 }
584 return sk_psock_skb_ingress(psock, skb);
585}
586
587static void sk_psock_skb_state(struct sk_psock *psock,
588 struct sk_psock_work_state *state,
589 struct sk_buff *skb,
590 int len, int off)
591{
592 spin_lock_bh(&psock->ingress_lock);
593 if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
594 state->skb = skb;
595 state->len = len;
596 state->off = off;
597 } else {
598 sock_drop(psock->sk, skb);
599 }
600 spin_unlock_bh(&psock->ingress_lock);
601}
602
603static void sk_psock_backlog(struct work_struct *work)
604{
605 struct sk_psock *psock = container_of(work, struct sk_psock, work);
606 struct sk_psock_work_state *state = &psock->work_state;
607 struct sk_buff *skb = NULL;
608 bool ingress;
609 u32 len, off;
610 int ret;
611
612 mutex_lock(&psock->work_mutex);
613 if (unlikely(state->skb)) {
614 spin_lock_bh(&psock->ingress_lock);
615 skb = state->skb;
616 len = state->len;
617 off = state->off;
618 state->skb = NULL;
619 spin_unlock_bh(&psock->ingress_lock);
620 }
621 if (skb)
622 goto start;
623
624 while ((skb = skb_dequeue(&psock->ingress_skb))) {
625 len = skb->len;
626 off = 0;
627start:
628 ingress = skb_bpf_ingress(skb);
629 skb_bpf_redirect_clear(skb);
630 do {
631 ret = -EIO;
632 if (!sock_flag(psock->sk, SOCK_DEAD))
633 ret = sk_psock_handle_skb(psock, skb, off,
634 len, ingress);
635 if (ret <= 0) {
636 if (ret == -EAGAIN) {
637 sk_psock_skb_state(psock, state, skb,
638 len, off);
639 goto end;
640 }
641 /* Hard errors break pipe and stop xmit. */
642 sk_psock_report_error(psock, ret ? -ret : EPIPE);
643 sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
644 sock_drop(psock->sk, skb);
645 goto end;
646 }
647 off += ret;
648 len -= ret;
649 } while (len);
650
651 if (!ingress)
652 kfree_skb(skb);
653 }
654end:
655 mutex_unlock(&psock->work_mutex);
656}
657
658struct sk_psock *sk_psock_init(struct sock *sk, int node)
659{
660 struct sk_psock *psock;
661 struct proto *prot;
662
663 write_lock_bh(&sk->sk_callback_lock);
664
665 if (sk->sk_user_data) {
666 psock = ERR_PTR(-EBUSY);
667 goto out;
668 }
669
670 psock = kzalloc_node(sizeof(*psock), GFP_ATOMIC | __GFP_NOWARN, node);
671 if (!psock) {
672 psock = ERR_PTR(-ENOMEM);
673 goto out;
674 }
675
676 prot = READ_ONCE(sk->sk_prot);
677 psock->sk = sk;
678 psock->eval = __SK_NONE;
679 psock->sk_proto = prot;
680 psock->saved_unhash = prot->unhash;
681 psock->saved_close = prot->close;
682 psock->saved_write_space = sk->sk_write_space;
683
684 INIT_LIST_HEAD(&psock->link);
685 spin_lock_init(&psock->link_lock);
686
687 INIT_WORK(&psock->work, sk_psock_backlog);
688 mutex_init(&psock->work_mutex);
689 INIT_LIST_HEAD(&psock->ingress_msg);
690 spin_lock_init(&psock->ingress_lock);
691 skb_queue_head_init(&psock->ingress_skb);
692
693 sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED);
694 refcount_set(&psock->refcnt, 1);
695
696 rcu_assign_sk_user_data_nocopy(sk, psock);
697 sock_hold(sk);
698
699out:
700 write_unlock_bh(&sk->sk_callback_lock);
701 return psock;
702}
703EXPORT_SYMBOL_GPL(sk_psock_init);
704
705struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock)
706{
707 struct sk_psock_link *link;
708
709 spin_lock_bh(&psock->link_lock);
710 link = list_first_entry_or_null(&psock->link, struct sk_psock_link,
711 list);
712 if (link)
713 list_del(&link->list);
714 spin_unlock_bh(&psock->link_lock);
715 return link;
716}
717
718static void __sk_psock_purge_ingress_msg(struct sk_psock *psock)
719{
720 struct sk_msg *msg, *tmp;
721
722 list_for_each_entry_safe(msg, tmp, &psock->ingress_msg, list) {
723 list_del(&msg->list);
724 sk_msg_free(psock->sk, msg);
725 kfree(msg);
726 }
727}
728
729static void __sk_psock_zap_ingress(struct sk_psock *psock)
730{
731 struct sk_buff *skb;
732
733 while ((skb = skb_dequeue(&psock->ingress_skb)) != NULL) {
734 skb_bpf_redirect_clear(skb);
735 sock_drop(psock->sk, skb);
736 }
737 kfree_skb(psock->work_state.skb);
738 /* We null the skb here to ensure that calls to sk_psock_backlog
739 * do not pick up the free'd skb.
740 */
741 psock->work_state.skb = NULL;
742 __sk_psock_purge_ingress_msg(psock);
743}
744
745static void sk_psock_link_destroy(struct sk_psock *psock)
746{
747 struct sk_psock_link *link, *tmp;
748
749 list_for_each_entry_safe(link, tmp, &psock->link, list) {
750 list_del(&link->list);
751 sk_psock_free_link(link);
752 }
753}
754
755void sk_psock_stop(struct sk_psock *psock, bool wait)
756{
757 spin_lock_bh(&psock->ingress_lock);
758 sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
759 sk_psock_cork_free(psock);
760 __sk_psock_zap_ingress(psock);
761 spin_unlock_bh(&psock->ingress_lock);
762
763 if (wait)
764 cancel_work_sync(&psock->work);
765}
766
767static void sk_psock_done_strp(struct sk_psock *psock);
768
769static void sk_psock_destroy(struct work_struct *work)
770{
771 struct sk_psock *psock = container_of(to_rcu_work(work),
772 struct sk_psock, rwork);
773 /* No sk_callback_lock since already detached. */
774
775 sk_psock_done_strp(psock);
776
777 cancel_work_sync(&psock->work);
778 mutex_destroy(&psock->work_mutex);
779
780 psock_progs_drop(&psock->progs);
781
782 sk_psock_link_destroy(psock);
783 sk_psock_cork_free(psock);
784
785 if (psock->sk_redir)
786 sock_put(psock->sk_redir);
787 sock_put(psock->sk);
788 kfree(psock);
789}
790
791void sk_psock_drop(struct sock *sk, struct sk_psock *psock)
792{
793 write_lock_bh(&sk->sk_callback_lock);
794 sk_psock_restore_proto(sk, psock);
795 rcu_assign_sk_user_data(sk, NULL);
796 if (psock->progs.stream_parser)
797 sk_psock_stop_strp(sk, psock);
798 else if (psock->progs.stream_verdict || psock->progs.skb_verdict)
799 sk_psock_stop_verdict(sk, psock);
800 write_unlock_bh(&sk->sk_callback_lock);
801
802 sk_psock_stop(psock, false);
803
804 INIT_RCU_WORK(&psock->rwork, sk_psock_destroy);
805 queue_rcu_work(system_wq, &psock->rwork);
806}
807EXPORT_SYMBOL_GPL(sk_psock_drop);
808
809static int sk_psock_map_verd(int verdict, bool redir)
810{
811 switch (verdict) {
812 case SK_PASS:
813 return redir ? __SK_REDIRECT : __SK_PASS;
814 case SK_DROP:
815 default:
816 break;
817 }
818
819 return __SK_DROP;
820}
821
822int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
823 struct sk_msg *msg)
824{
825 struct bpf_prog *prog;
826 int ret;
827
828 rcu_read_lock();
829 prog = READ_ONCE(psock->progs.msg_parser);
830 if (unlikely(!prog)) {
831 ret = __SK_PASS;
832 goto out;
833 }
834
835 sk_msg_compute_data_pointers(msg);
836 msg->sk = sk;
837 ret = bpf_prog_run_pin_on_cpu(prog, msg);
838 ret = sk_psock_map_verd(ret, msg->sk_redir);
839 psock->apply_bytes = msg->apply_bytes;
840 if (ret == __SK_REDIRECT) {
841 if (psock->sk_redir)
842 sock_put(psock->sk_redir);
843 psock->sk_redir = msg->sk_redir;
844 if (!psock->sk_redir) {
845 ret = __SK_DROP;
846 goto out;
847 }
848 sock_hold(psock->sk_redir);
849 }
850out:
851 rcu_read_unlock();
852 return ret;
853}
854EXPORT_SYMBOL_GPL(sk_psock_msg_verdict);
855
856static int sk_psock_skb_redirect(struct sk_psock *from, struct sk_buff *skb)
857{
858 struct sk_psock *psock_other;
859 struct sock *sk_other;
860
861 sk_other = skb_bpf_redirect_fetch(skb);
862 /* This error is a buggy BPF program, it returned a redirect
863 * return code, but then didn't set a redirect interface.
864 */
865 if (unlikely(!sk_other)) {
866 sock_drop(from->sk, skb);
867 return -EIO;
868 }
869 psock_other = sk_psock(sk_other);
870 /* This error indicates the socket is being torn down or had another
871 * error that caused the pipe to break. We can't send a packet on
872 * a socket that is in this state so we drop the skb.
873 */
874 if (!psock_other || sock_flag(sk_other, SOCK_DEAD)) {
875 skb_bpf_redirect_clear(skb);
876 sock_drop(from->sk, skb);
877 return -EIO;
878 }
879 spin_lock_bh(&psock_other->ingress_lock);
880 if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) {
881 spin_unlock_bh(&psock_other->ingress_lock);
882 skb_bpf_redirect_clear(skb);
883 sock_drop(from->sk, skb);
884 return -EIO;
885 }
886
887 skb_queue_tail(&psock_other->ingress_skb, skb);
888 schedule_work(&psock_other->work);
889 spin_unlock_bh(&psock_other->ingress_lock);
890 return 0;
891}
892
893static void sk_psock_tls_verdict_apply(struct sk_buff *skb,
894 struct sk_psock *from, int verdict)
895{
896 switch (verdict) {
897 case __SK_REDIRECT:
898 sk_psock_skb_redirect(from, skb);
899 break;
900 case __SK_PASS:
901 case __SK_DROP:
902 default:
903 break;
904 }
905}
906
907int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb)
908{
909 struct bpf_prog *prog;
910 int ret = __SK_PASS;
911
912 rcu_read_lock();
913 prog = READ_ONCE(psock->progs.stream_verdict);
914 if (likely(prog)) {
915 skb->sk = psock->sk;
916 skb_dst_drop(skb);
917 skb_bpf_redirect_clear(skb);
918 ret = bpf_prog_run_pin_on_cpu(prog, skb);
919 ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb));
920 skb->sk = NULL;
921 }
922 sk_psock_tls_verdict_apply(skb, psock, ret);
923 rcu_read_unlock();
924 return ret;
925}
926EXPORT_SYMBOL_GPL(sk_psock_tls_strp_read);
927
928static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb,
929 int verdict)
930{
931 struct sock *sk_other;
932 int err = 0;
933
934 switch (verdict) {
935 case __SK_PASS:
936 err = -EIO;
937 sk_other = psock->sk;
938 if (sock_flag(sk_other, SOCK_DEAD) ||
939 !sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
940 goto out_free;
941 }
942
943 skb_bpf_set_ingress(skb);
944
945 /* If the queue is empty then we can submit directly
946 * into the msg queue. If its not empty we have to
947 * queue work otherwise we may get OOO data. Otherwise,
948 * if sk_psock_skb_ingress errors will be handled by
949 * retrying later from workqueue.
950 */
951 if (skb_queue_empty(&psock->ingress_skb)) {
952 err = sk_psock_skb_ingress_self(psock, skb);
953 }
954 if (err < 0) {
955 spin_lock_bh(&psock->ingress_lock);
956 if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
957 skb_queue_tail(&psock->ingress_skb, skb);
958 schedule_work(&psock->work);
959 err = 0;
960 }
961 spin_unlock_bh(&psock->ingress_lock);
962 if (err < 0) {
963 skb_bpf_redirect_clear(skb);
964 goto out_free;
965 }
966 }
967 break;
968 case __SK_REDIRECT:
969 err = sk_psock_skb_redirect(psock, skb);
970 break;
971 case __SK_DROP:
972 default:
973out_free:
974 sock_drop(psock->sk, skb);
975 }
976
977 return err;
978}
979
980static void sk_psock_write_space(struct sock *sk)
981{
982 struct sk_psock *psock;
983 void (*write_space)(struct sock *sk) = NULL;
984
985 rcu_read_lock();
986 psock = sk_psock(sk);
987 if (likely(psock)) {
988 if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
989 schedule_work(&psock->work);
990 write_space = psock->saved_write_space;
991 }
992 rcu_read_unlock();
993 if (write_space)
994 write_space(sk);
995}
996
997#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
998static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb)
999{
1000 struct sk_psock *psock;
1001 struct bpf_prog *prog;
1002 int ret = __SK_DROP;
1003 struct sock *sk;
1004
1005 rcu_read_lock();
1006 sk = strp->sk;
1007 psock = sk_psock(sk);
1008 if (unlikely(!psock)) {
1009 sock_drop(sk, skb);
1010 goto out;
1011 }
1012 prog = READ_ONCE(psock->progs.stream_verdict);
1013 if (likely(prog)) {
1014 skb->sk = sk;
1015 skb_dst_drop(skb);
1016 skb_bpf_redirect_clear(skb);
1017 ret = bpf_prog_run_pin_on_cpu(prog, skb);
1018 ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb));
1019 skb->sk = NULL;
1020 }
1021 sk_psock_verdict_apply(psock, skb, ret);
1022out:
1023 rcu_read_unlock();
1024}
1025
1026static int sk_psock_strp_read_done(struct strparser *strp, int err)
1027{
1028 return err;
1029}
1030
1031static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb)
1032{
1033 struct sk_psock *psock = container_of(strp, struct sk_psock, strp);
1034 struct bpf_prog *prog;
1035 int ret = skb->len;
1036
1037 rcu_read_lock();
1038 prog = READ_ONCE(psock->progs.stream_parser);
1039 if (likely(prog)) {
1040 skb->sk = psock->sk;
1041 ret = bpf_prog_run_pin_on_cpu(prog, skb);
1042 skb->sk = NULL;
1043 }
1044 rcu_read_unlock();
1045 return ret;
1046}
1047
1048/* Called with socket lock held. */
1049static void sk_psock_strp_data_ready(struct sock *sk)
1050{
1051 struct sk_psock *psock;
1052
1053 rcu_read_lock();
1054 psock = sk_psock(sk);
1055 if (likely(psock)) {
1056 if (tls_sw_has_ctx_rx(sk)) {
1057 psock->saved_data_ready(sk);
1058 } else {
1059 write_lock_bh(&sk->sk_callback_lock);
1060 strp_data_ready(&psock->strp);
1061 write_unlock_bh(&sk->sk_callback_lock);
1062 }
1063 }
1064 rcu_read_unlock();
1065}
1066
1067int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
1068{
1069 static const struct strp_callbacks cb = {
1070 .rcv_msg = sk_psock_strp_read,
1071 .read_sock_done = sk_psock_strp_read_done,
1072 .parse_msg = sk_psock_strp_parse,
1073 };
1074
1075 return strp_init(&psock->strp, sk, &cb);
1076}
1077
1078void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
1079{
1080 if (psock->saved_data_ready)
1081 return;
1082
1083 psock->saved_data_ready = sk->sk_data_ready;
1084 sk->sk_data_ready = sk_psock_strp_data_ready;
1085 sk->sk_write_space = sk_psock_write_space;
1086}
1087
1088void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
1089{
1090 if (!psock->saved_data_ready)
1091 return;
1092
1093 sk->sk_data_ready = psock->saved_data_ready;
1094 psock->saved_data_ready = NULL;
1095 strp_stop(&psock->strp);
1096}
1097
1098static void sk_psock_done_strp(struct sk_psock *psock)
1099{
1100 /* Parser has been stopped */
1101 if (psock->progs.stream_parser)
1102 strp_done(&psock->strp);
1103}
1104#else
1105static void sk_psock_done_strp(struct sk_psock *psock)
1106{
1107}
1108#endif /* CONFIG_BPF_STREAM_PARSER */
1109
1110static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb,
1111 unsigned int offset, size_t orig_len)
1112{
1113 struct sock *sk = (struct sock *)desc->arg.data;
1114 struct sk_psock *psock;
1115 struct bpf_prog *prog;
1116 int ret = __SK_DROP;
1117 int len = skb->len;
1118
1119 /* clone here so sk_eat_skb() in tcp_read_sock does not drop our data */
1120 skb = skb_clone(skb, GFP_ATOMIC);
1121 if (!skb) {
1122 desc->error = -ENOMEM;
1123 return 0;
1124 }
1125
1126 rcu_read_lock();
1127 psock = sk_psock(sk);
1128 if (unlikely(!psock)) {
1129 len = 0;
1130 sock_drop(sk, skb);
1131 goto out;
1132 }
1133 prog = READ_ONCE(psock->progs.stream_verdict);
1134 if (!prog)
1135 prog = READ_ONCE(psock->progs.skb_verdict);
1136 if (likely(prog)) {
1137 skb->sk = sk;
1138 skb_dst_drop(skb);
1139 skb_bpf_redirect_clear(skb);
1140 ret = bpf_prog_run_pin_on_cpu(prog, skb);
1141 ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb));
1142 skb->sk = NULL;
1143 }
1144 if (sk_psock_verdict_apply(psock, skb, ret) < 0)
1145 len = 0;
1146out:
1147 rcu_read_unlock();
1148 return len;
1149}
1150
1151static void sk_psock_verdict_data_ready(struct sock *sk)
1152{
1153 struct socket *sock = sk->sk_socket;
1154 read_descriptor_t desc;
1155
1156 if (unlikely(!sock || !sock->ops || !sock->ops->read_sock))
1157 return;
1158
1159 desc.arg.data = sk;
1160 desc.error = 0;
1161 desc.count = 1;
1162
1163 sock->ops->read_sock(sk, &desc, sk_psock_verdict_recv);
1164}
1165
1166void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock)
1167{
1168 if (psock->saved_data_ready)
1169 return;
1170
1171 psock->saved_data_ready = sk->sk_data_ready;
1172 sk->sk_data_ready = sk_psock_verdict_data_ready;
1173 sk->sk_write_space = sk_psock_write_space;
1174}
1175
1176void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock)
1177{
1178 if (!psock->saved_data_ready)
1179 return;
1180
1181 sk->sk_data_ready = psock->saved_data_ready;
1182 psock->saved_data_ready = NULL;
1183}
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#include <net/tls.h>
11
12static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce)
13{
14 if (msg->sg.end > msg->sg.start &&
15 elem_first_coalesce < msg->sg.end)
16 return true;
17
18 if (msg->sg.end < msg->sg.start &&
19 (elem_first_coalesce > msg->sg.start ||
20 elem_first_coalesce < msg->sg.end))
21 return true;
22
23 return false;
24}
25
26int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
27 int elem_first_coalesce)
28{
29 struct page_frag *pfrag = sk_page_frag(sk);
30 int ret = 0;
31
32 len -= msg->sg.size;
33 while (len > 0) {
34 struct scatterlist *sge;
35 u32 orig_offset;
36 int use, i;
37
38 if (!sk_page_frag_refill(sk, pfrag))
39 return -ENOMEM;
40
41 orig_offset = pfrag->offset;
42 use = min_t(int, len, pfrag->size - orig_offset);
43 if (!sk_wmem_schedule(sk, use))
44 return -ENOMEM;
45
46 i = msg->sg.end;
47 sk_msg_iter_var_prev(i);
48 sge = &msg->sg.data[i];
49
50 if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) &&
51 sg_page(sge) == pfrag->page &&
52 sge->offset + sge->length == orig_offset) {
53 sge->length += use;
54 } else {
55 if (sk_msg_full(msg)) {
56 ret = -ENOSPC;
57 break;
58 }
59
60 sge = &msg->sg.data[msg->sg.end];
61 sg_unmark_end(sge);
62 sg_set_page(sge, pfrag->page, use, orig_offset);
63 get_page(pfrag->page);
64 sk_msg_iter_next(msg, end);
65 }
66
67 sk_mem_charge(sk, use);
68 msg->sg.size += use;
69 pfrag->offset += use;
70 len -= use;
71 }
72
73 return ret;
74}
75EXPORT_SYMBOL_GPL(sk_msg_alloc);
76
77int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src,
78 u32 off, u32 len)
79{
80 int i = src->sg.start;
81 struct scatterlist *sge = sk_msg_elem(src, i);
82 struct scatterlist *sgd = NULL;
83 u32 sge_len, sge_off;
84
85 while (off) {
86 if (sge->length > off)
87 break;
88 off -= sge->length;
89 sk_msg_iter_var_next(i);
90 if (i == src->sg.end && off)
91 return -ENOSPC;
92 sge = sk_msg_elem(src, i);
93 }
94
95 while (len) {
96 sge_len = sge->length - off;
97 if (sge_len > len)
98 sge_len = len;
99
100 if (dst->sg.end)
101 sgd = sk_msg_elem(dst, dst->sg.end - 1);
102
103 if (sgd &&
104 (sg_page(sge) == sg_page(sgd)) &&
105 (sg_virt(sge) + off == sg_virt(sgd) + sgd->length)) {
106 sgd->length += sge_len;
107 dst->sg.size += sge_len;
108 } else if (!sk_msg_full(dst)) {
109 sge_off = sge->offset + off;
110 sk_msg_page_add(dst, sg_page(sge), sge_len, sge_off);
111 } else {
112 return -ENOSPC;
113 }
114
115 off = 0;
116 len -= sge_len;
117 sk_mem_charge(sk, sge_len);
118 sk_msg_iter_var_next(i);
119 if (i == src->sg.end && len)
120 return -ENOSPC;
121 sge = sk_msg_elem(src, i);
122 }
123
124 return 0;
125}
126EXPORT_SYMBOL_GPL(sk_msg_clone);
127
128void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes)
129{
130 int i = msg->sg.start;
131
132 do {
133 struct scatterlist *sge = sk_msg_elem(msg, i);
134
135 if (bytes < sge->length) {
136 sge->length -= bytes;
137 sge->offset += bytes;
138 sk_mem_uncharge(sk, bytes);
139 break;
140 }
141
142 sk_mem_uncharge(sk, sge->length);
143 bytes -= sge->length;
144 sge->length = 0;
145 sge->offset = 0;
146 sk_msg_iter_var_next(i);
147 } while (bytes && i != msg->sg.end);
148 msg->sg.start = i;
149}
150EXPORT_SYMBOL_GPL(sk_msg_return_zero);
151
152void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes)
153{
154 int i = msg->sg.start;
155
156 do {
157 struct scatterlist *sge = &msg->sg.data[i];
158 int uncharge = (bytes < sge->length) ? bytes : sge->length;
159
160 sk_mem_uncharge(sk, uncharge);
161 bytes -= uncharge;
162 sk_msg_iter_var_next(i);
163 } while (i != msg->sg.end);
164}
165EXPORT_SYMBOL_GPL(sk_msg_return);
166
167static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
168 bool charge)
169{
170 struct scatterlist *sge = sk_msg_elem(msg, i);
171 u32 len = sge->length;
172
173 if (charge)
174 sk_mem_uncharge(sk, len);
175 if (!msg->skb)
176 put_page(sg_page(sge));
177 memset(sge, 0, sizeof(*sge));
178 return len;
179}
180
181static int __sk_msg_free(struct sock *sk, struct sk_msg *msg, u32 i,
182 bool charge)
183{
184 struct scatterlist *sge = sk_msg_elem(msg, i);
185 int freed = 0;
186
187 while (msg->sg.size) {
188 msg->sg.size -= sge->length;
189 freed += sk_msg_free_elem(sk, msg, i, charge);
190 sk_msg_iter_var_next(i);
191 sk_msg_check_to_free(msg, i, msg->sg.size);
192 sge = sk_msg_elem(msg, i);
193 }
194 consume_skb(msg->skb);
195 sk_msg_init(msg);
196 return freed;
197}
198
199int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg)
200{
201 return __sk_msg_free(sk, msg, msg->sg.start, false);
202}
203EXPORT_SYMBOL_GPL(sk_msg_free_nocharge);
204
205int sk_msg_free(struct sock *sk, struct sk_msg *msg)
206{
207 return __sk_msg_free(sk, msg, msg->sg.start, true);
208}
209EXPORT_SYMBOL_GPL(sk_msg_free);
210
211static void __sk_msg_free_partial(struct sock *sk, struct sk_msg *msg,
212 u32 bytes, bool charge)
213{
214 struct scatterlist *sge;
215 u32 i = msg->sg.start;
216
217 while (bytes) {
218 sge = sk_msg_elem(msg, i);
219 if (!sge->length)
220 break;
221 if (bytes < sge->length) {
222 if (charge)
223 sk_mem_uncharge(sk, bytes);
224 sge->length -= bytes;
225 sge->offset += bytes;
226 msg->sg.size -= bytes;
227 break;
228 }
229
230 msg->sg.size -= sge->length;
231 bytes -= sge->length;
232 sk_msg_free_elem(sk, msg, i, charge);
233 sk_msg_iter_var_next(i);
234 sk_msg_check_to_free(msg, i, bytes);
235 }
236 msg->sg.start = i;
237}
238
239void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes)
240{
241 __sk_msg_free_partial(sk, msg, bytes, true);
242}
243EXPORT_SYMBOL_GPL(sk_msg_free_partial);
244
245void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
246 u32 bytes)
247{
248 __sk_msg_free_partial(sk, msg, bytes, false);
249}
250
251void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len)
252{
253 int trim = msg->sg.size - len;
254 u32 i = msg->sg.end;
255
256 if (trim <= 0) {
257 WARN_ON(trim < 0);
258 return;
259 }
260
261 sk_msg_iter_var_prev(i);
262 msg->sg.size = len;
263 while (msg->sg.data[i].length &&
264 trim >= msg->sg.data[i].length) {
265 trim -= msg->sg.data[i].length;
266 sk_msg_free_elem(sk, msg, i, true);
267 sk_msg_iter_var_prev(i);
268 if (!trim)
269 goto out;
270 }
271
272 msg->sg.data[i].length -= trim;
273 sk_mem_uncharge(sk, trim);
274 /* Adjust copybreak if it falls into the trimmed part of last buf */
275 if (msg->sg.curr == i && msg->sg.copybreak > msg->sg.data[i].length)
276 msg->sg.copybreak = msg->sg.data[i].length;
277out:
278 sk_msg_iter_var_next(i);
279 msg->sg.end = i;
280
281 /* If we trim data a full sg elem before curr pointer update
282 * copybreak and current so that any future copy operations
283 * start at new copy location.
284 * However trimed data that has not yet been used in a copy op
285 * does not require an update.
286 */
287 if (!msg->sg.size) {
288 msg->sg.curr = msg->sg.start;
289 msg->sg.copybreak = 0;
290 } else if (sk_msg_iter_dist(msg->sg.start, msg->sg.curr) >=
291 sk_msg_iter_dist(msg->sg.start, msg->sg.end)) {
292 sk_msg_iter_var_prev(i);
293 msg->sg.curr = i;
294 msg->sg.copybreak = msg->sg.data[i].length;
295 }
296}
297EXPORT_SYMBOL_GPL(sk_msg_trim);
298
299int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
300 struct sk_msg *msg, u32 bytes)
301{
302 int i, maxpages, ret = 0, num_elems = sk_msg_elem_used(msg);
303 const int to_max_pages = MAX_MSG_FRAGS;
304 struct page *pages[MAX_MSG_FRAGS];
305 ssize_t orig, copied, use, offset;
306
307 orig = msg->sg.size;
308 while (bytes > 0) {
309 i = 0;
310 maxpages = to_max_pages - num_elems;
311 if (maxpages == 0) {
312 ret = -EFAULT;
313 goto out;
314 }
315
316 copied = iov_iter_get_pages(from, pages, bytes, maxpages,
317 &offset);
318 if (copied <= 0) {
319 ret = -EFAULT;
320 goto out;
321 }
322
323 iov_iter_advance(from, copied);
324 bytes -= copied;
325 msg->sg.size += copied;
326
327 while (copied) {
328 use = min_t(int, copied, PAGE_SIZE - offset);
329 sg_set_page(&msg->sg.data[msg->sg.end],
330 pages[i], use, offset);
331 sg_unmark_end(&msg->sg.data[msg->sg.end]);
332 sk_mem_charge(sk, use);
333
334 offset = 0;
335 copied -= use;
336 sk_msg_iter_next(msg, end);
337 num_elems++;
338 i++;
339 }
340 /* When zerocopy is mixed with sk_msg_*copy* operations we
341 * may have a copybreak set in this case clear and prefer
342 * zerocopy remainder when possible.
343 */
344 msg->sg.copybreak = 0;
345 msg->sg.curr = msg->sg.end;
346 }
347out:
348 /* Revert iov_iter updates, msg will need to use 'trim' later if it
349 * also needs to be cleared.
350 */
351 if (ret)
352 iov_iter_revert(from, msg->sg.size - orig);
353 return ret;
354}
355EXPORT_SYMBOL_GPL(sk_msg_zerocopy_from_iter);
356
357int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
358 struct sk_msg *msg, u32 bytes)
359{
360 int ret = -ENOSPC, i = msg->sg.curr;
361 struct scatterlist *sge;
362 u32 copy, buf_size;
363 void *to;
364
365 do {
366 sge = sk_msg_elem(msg, i);
367 /* This is possible if a trim operation shrunk the buffer */
368 if (msg->sg.copybreak >= sge->length) {
369 msg->sg.copybreak = 0;
370 sk_msg_iter_var_next(i);
371 if (i == msg->sg.end)
372 break;
373 sge = sk_msg_elem(msg, i);
374 }
375
376 buf_size = sge->length - msg->sg.copybreak;
377 copy = (buf_size > bytes) ? bytes : buf_size;
378 to = sg_virt(sge) + msg->sg.copybreak;
379 msg->sg.copybreak += copy;
380 if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY)
381 ret = copy_from_iter_nocache(to, copy, from);
382 else
383 ret = copy_from_iter(to, copy, from);
384 if (ret != copy) {
385 ret = -EFAULT;
386 goto out;
387 }
388 bytes -= copy;
389 if (!bytes)
390 break;
391 msg->sg.copybreak = 0;
392 sk_msg_iter_var_next(i);
393 } while (i != msg->sg.end);
394out:
395 msg->sg.curr = i;
396 return ret;
397}
398EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter);
399
400static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
401{
402 struct sock *sk = psock->sk;
403 int copied = 0, num_sge;
404 struct sk_msg *msg;
405
406 msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC);
407 if (unlikely(!msg))
408 return -EAGAIN;
409 if (!sk_rmem_schedule(sk, skb, skb->len)) {
410 kfree(msg);
411 return -EAGAIN;
412 }
413
414 sk_msg_init(msg);
415 num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len);
416 if (unlikely(num_sge < 0)) {
417 kfree(msg);
418 return num_sge;
419 }
420
421 sk_mem_charge(sk, skb->len);
422 copied = skb->len;
423 msg->sg.start = 0;
424 msg->sg.size = copied;
425 msg->sg.end = num_sge;
426 msg->skb = skb;
427
428 sk_psock_queue_msg(psock, msg);
429 sk_psock_data_ready(sk, psock);
430 return copied;
431}
432
433static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
434 u32 off, u32 len, bool ingress)
435{
436 if (ingress)
437 return sk_psock_skb_ingress(psock, skb);
438 else
439 return skb_send_sock_locked(psock->sk, skb, off, len);
440}
441
442static void sk_psock_backlog(struct work_struct *work)
443{
444 struct sk_psock *psock = container_of(work, struct sk_psock, work);
445 struct sk_psock_work_state *state = &psock->work_state;
446 struct sk_buff *skb;
447 bool ingress;
448 u32 len, off;
449 int ret;
450
451 /* Lock sock to avoid losing sk_socket during loop. */
452 lock_sock(psock->sk);
453 if (state->skb) {
454 skb = state->skb;
455 len = state->len;
456 off = state->off;
457 state->skb = NULL;
458 goto start;
459 }
460
461 while ((skb = skb_dequeue(&psock->ingress_skb))) {
462 len = skb->len;
463 off = 0;
464start:
465 ingress = tcp_skb_bpf_ingress(skb);
466 do {
467 ret = -EIO;
468 if (likely(psock->sk->sk_socket))
469 ret = sk_psock_handle_skb(psock, skb, off,
470 len, ingress);
471 if (ret <= 0) {
472 if (ret == -EAGAIN) {
473 state->skb = skb;
474 state->len = len;
475 state->off = off;
476 goto end;
477 }
478 /* Hard errors break pipe and stop xmit. */
479 sk_psock_report_error(psock, ret ? -ret : EPIPE);
480 sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
481 kfree_skb(skb);
482 goto end;
483 }
484 off += ret;
485 len -= ret;
486 } while (len);
487
488 if (!ingress)
489 kfree_skb(skb);
490 }
491end:
492 release_sock(psock->sk);
493}
494
495struct sk_psock *sk_psock_init(struct sock *sk, int node)
496{
497 struct sk_psock *psock = kzalloc_node(sizeof(*psock),
498 GFP_ATOMIC | __GFP_NOWARN,
499 node);
500 if (!psock)
501 return NULL;
502
503 psock->sk = sk;
504 psock->eval = __SK_NONE;
505
506 INIT_LIST_HEAD(&psock->link);
507 spin_lock_init(&psock->link_lock);
508
509 INIT_WORK(&psock->work, sk_psock_backlog);
510 INIT_LIST_HEAD(&psock->ingress_msg);
511 skb_queue_head_init(&psock->ingress_skb);
512
513 sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED);
514 refcount_set(&psock->refcnt, 1);
515
516 rcu_assign_sk_user_data_nocopy(sk, psock);
517 sock_hold(sk);
518
519 return psock;
520}
521EXPORT_SYMBOL_GPL(sk_psock_init);
522
523struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock)
524{
525 struct sk_psock_link *link;
526
527 spin_lock_bh(&psock->link_lock);
528 link = list_first_entry_or_null(&psock->link, struct sk_psock_link,
529 list);
530 if (link)
531 list_del(&link->list);
532 spin_unlock_bh(&psock->link_lock);
533 return link;
534}
535
536void __sk_psock_purge_ingress_msg(struct sk_psock *psock)
537{
538 struct sk_msg *msg, *tmp;
539
540 list_for_each_entry_safe(msg, tmp, &psock->ingress_msg, list) {
541 list_del(&msg->list);
542 sk_msg_free(psock->sk, msg);
543 kfree(msg);
544 }
545}
546
547static void sk_psock_zap_ingress(struct sk_psock *psock)
548{
549 __skb_queue_purge(&psock->ingress_skb);
550 __sk_psock_purge_ingress_msg(psock);
551}
552
553static void sk_psock_link_destroy(struct sk_psock *psock)
554{
555 struct sk_psock_link *link, *tmp;
556
557 list_for_each_entry_safe(link, tmp, &psock->link, list) {
558 list_del(&link->list);
559 sk_psock_free_link(link);
560 }
561}
562
563static void sk_psock_destroy_deferred(struct work_struct *gc)
564{
565 struct sk_psock *psock = container_of(gc, struct sk_psock, gc);
566
567 /* No sk_callback_lock since already detached. */
568
569 /* Parser has been stopped */
570 if (psock->progs.skb_parser)
571 strp_done(&psock->parser.strp);
572
573 cancel_work_sync(&psock->work);
574
575 psock_progs_drop(&psock->progs);
576
577 sk_psock_link_destroy(psock);
578 sk_psock_cork_free(psock);
579 sk_psock_zap_ingress(psock);
580
581 if (psock->sk_redir)
582 sock_put(psock->sk_redir);
583 sock_put(psock->sk);
584 kfree(psock);
585}
586
587void sk_psock_destroy(struct rcu_head *rcu)
588{
589 struct sk_psock *psock = container_of(rcu, struct sk_psock, rcu);
590
591 INIT_WORK(&psock->gc, sk_psock_destroy_deferred);
592 schedule_work(&psock->gc);
593}
594EXPORT_SYMBOL_GPL(sk_psock_destroy);
595
596void sk_psock_drop(struct sock *sk, struct sk_psock *psock)
597{
598 sk_psock_cork_free(psock);
599 sk_psock_zap_ingress(psock);
600
601 write_lock_bh(&sk->sk_callback_lock);
602 sk_psock_restore_proto(sk, psock);
603 rcu_assign_sk_user_data(sk, NULL);
604 if (psock->progs.skb_parser)
605 sk_psock_stop_strp(sk, psock);
606 write_unlock_bh(&sk->sk_callback_lock);
607 sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
608
609 call_rcu(&psock->rcu, sk_psock_destroy);
610}
611EXPORT_SYMBOL_GPL(sk_psock_drop);
612
613static int sk_psock_map_verd(int verdict, bool redir)
614{
615 switch (verdict) {
616 case SK_PASS:
617 return redir ? __SK_REDIRECT : __SK_PASS;
618 case SK_DROP:
619 default:
620 break;
621 }
622
623 return __SK_DROP;
624}
625
626int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
627 struct sk_msg *msg)
628{
629 struct bpf_prog *prog;
630 int ret;
631
632 rcu_read_lock();
633 prog = READ_ONCE(psock->progs.msg_parser);
634 if (unlikely(!prog)) {
635 ret = __SK_PASS;
636 goto out;
637 }
638
639 sk_msg_compute_data_pointers(msg);
640 msg->sk = sk;
641 ret = bpf_prog_run_pin_on_cpu(prog, msg);
642 ret = sk_psock_map_verd(ret, msg->sk_redir);
643 psock->apply_bytes = msg->apply_bytes;
644 if (ret == __SK_REDIRECT) {
645 if (psock->sk_redir)
646 sock_put(psock->sk_redir);
647 psock->sk_redir = msg->sk_redir;
648 if (!psock->sk_redir) {
649 ret = __SK_DROP;
650 goto out;
651 }
652 sock_hold(psock->sk_redir);
653 }
654out:
655 rcu_read_unlock();
656 return ret;
657}
658EXPORT_SYMBOL_GPL(sk_psock_msg_verdict);
659
660static int sk_psock_bpf_run(struct sk_psock *psock, struct bpf_prog *prog,
661 struct sk_buff *skb)
662{
663 int ret;
664
665 skb->sk = psock->sk;
666 bpf_compute_data_end_sk_skb(skb);
667 ret = bpf_prog_run_pin_on_cpu(prog, skb);
668 /* strparser clones the skb before handing it to a upper layer,
669 * meaning skb_orphan has been called. We NULL sk on the way out
670 * to ensure we don't trigger a BUG_ON() in skb/sk operations
671 * later and because we are not charging the memory of this skb
672 * to any socket yet.
673 */
674 skb->sk = NULL;
675 return ret;
676}
677
678static struct sk_psock *sk_psock_from_strp(struct strparser *strp)
679{
680 struct sk_psock_parser *parser;
681
682 parser = container_of(strp, struct sk_psock_parser, strp);
683 return container_of(parser, struct sk_psock, parser);
684}
685
686static void sk_psock_skb_redirect(struct sk_buff *skb)
687{
688 struct sk_psock *psock_other;
689 struct sock *sk_other;
690 bool ingress;
691
692 sk_other = tcp_skb_bpf_redirect_fetch(skb);
693 if (unlikely(!sk_other)) {
694 kfree_skb(skb);
695 return;
696 }
697 psock_other = sk_psock(sk_other);
698 if (!psock_other || sock_flag(sk_other, SOCK_DEAD) ||
699 !sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) {
700 kfree_skb(skb);
701 return;
702 }
703
704 ingress = tcp_skb_bpf_ingress(skb);
705 if ((!ingress && sock_writeable(sk_other)) ||
706 (ingress &&
707 atomic_read(&sk_other->sk_rmem_alloc) <=
708 sk_other->sk_rcvbuf)) {
709 if (!ingress)
710 skb_set_owner_w(skb, sk_other);
711 skb_queue_tail(&psock_other->ingress_skb, skb);
712 schedule_work(&psock_other->work);
713 } else {
714 kfree_skb(skb);
715 }
716}
717
718static void sk_psock_tls_verdict_apply(struct sk_buff *skb, int verdict)
719{
720 switch (verdict) {
721 case __SK_REDIRECT:
722 sk_psock_skb_redirect(skb);
723 break;
724 case __SK_PASS:
725 case __SK_DROP:
726 default:
727 break;
728 }
729}
730
731int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb)
732{
733 struct bpf_prog *prog;
734 int ret = __SK_PASS;
735
736 rcu_read_lock();
737 prog = READ_ONCE(psock->progs.skb_verdict);
738 if (likely(prog)) {
739 tcp_skb_bpf_redirect_clear(skb);
740 ret = sk_psock_bpf_run(psock, prog, skb);
741 ret = sk_psock_map_verd(ret, tcp_skb_bpf_redirect_fetch(skb));
742 }
743 sk_psock_tls_verdict_apply(skb, ret);
744 rcu_read_unlock();
745 return ret;
746}
747EXPORT_SYMBOL_GPL(sk_psock_tls_strp_read);
748
749static void sk_psock_verdict_apply(struct sk_psock *psock,
750 struct sk_buff *skb, int verdict)
751{
752 struct sock *sk_other;
753
754 switch (verdict) {
755 case __SK_PASS:
756 sk_other = psock->sk;
757 if (sock_flag(sk_other, SOCK_DEAD) ||
758 !sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
759 goto out_free;
760 }
761 if (atomic_read(&sk_other->sk_rmem_alloc) <=
762 sk_other->sk_rcvbuf) {
763 struct tcp_skb_cb *tcp = TCP_SKB_CB(skb);
764
765 tcp->bpf.flags |= BPF_F_INGRESS;
766 skb_queue_tail(&psock->ingress_skb, skb);
767 schedule_work(&psock->work);
768 break;
769 }
770 goto out_free;
771 case __SK_REDIRECT:
772 sk_psock_skb_redirect(skb);
773 break;
774 case __SK_DROP:
775 default:
776out_free:
777 kfree_skb(skb);
778 }
779}
780
781static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb)
782{
783 struct sk_psock *psock;
784 struct bpf_prog *prog;
785 int ret = __SK_DROP;
786 struct sock *sk;
787
788 rcu_read_lock();
789 sk = strp->sk;
790 psock = sk_psock(sk);
791 if (unlikely(!psock)) {
792 kfree_skb(skb);
793 goto out;
794 }
795 prog = READ_ONCE(psock->progs.skb_verdict);
796 if (likely(prog)) {
797 skb_orphan(skb);
798 tcp_skb_bpf_redirect_clear(skb);
799 ret = sk_psock_bpf_run(psock, prog, skb);
800 ret = sk_psock_map_verd(ret, tcp_skb_bpf_redirect_fetch(skb));
801 }
802 sk_psock_verdict_apply(psock, skb, ret);
803out:
804 rcu_read_unlock();
805}
806
807static int sk_psock_strp_read_done(struct strparser *strp, int err)
808{
809 return err;
810}
811
812static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb)
813{
814 struct sk_psock *psock = sk_psock_from_strp(strp);
815 struct bpf_prog *prog;
816 int ret = skb->len;
817
818 rcu_read_lock();
819 prog = READ_ONCE(psock->progs.skb_parser);
820 if (likely(prog))
821 ret = sk_psock_bpf_run(psock, prog, skb);
822 rcu_read_unlock();
823 return ret;
824}
825
826/* Called with socket lock held. */
827static void sk_psock_strp_data_ready(struct sock *sk)
828{
829 struct sk_psock *psock;
830
831 rcu_read_lock();
832 psock = sk_psock(sk);
833 if (likely(psock)) {
834 if (tls_sw_has_ctx_rx(sk)) {
835 psock->parser.saved_data_ready(sk);
836 } else {
837 write_lock_bh(&sk->sk_callback_lock);
838 strp_data_ready(&psock->parser.strp);
839 write_unlock_bh(&sk->sk_callback_lock);
840 }
841 }
842 rcu_read_unlock();
843}
844
845static void sk_psock_write_space(struct sock *sk)
846{
847 struct sk_psock *psock;
848 void (*write_space)(struct sock *sk) = NULL;
849
850 rcu_read_lock();
851 psock = sk_psock(sk);
852 if (likely(psock)) {
853 if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
854 schedule_work(&psock->work);
855 write_space = psock->saved_write_space;
856 }
857 rcu_read_unlock();
858 if (write_space)
859 write_space(sk);
860}
861
862int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
863{
864 static const struct strp_callbacks cb = {
865 .rcv_msg = sk_psock_strp_read,
866 .read_sock_done = sk_psock_strp_read_done,
867 .parse_msg = sk_psock_strp_parse,
868 };
869
870 psock->parser.enabled = false;
871 return strp_init(&psock->parser.strp, sk, &cb);
872}
873
874void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
875{
876 struct sk_psock_parser *parser = &psock->parser;
877
878 if (parser->enabled)
879 return;
880
881 parser->saved_data_ready = sk->sk_data_ready;
882 sk->sk_data_ready = sk_psock_strp_data_ready;
883 sk->sk_write_space = sk_psock_write_space;
884 parser->enabled = true;
885}
886
887void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
888{
889 struct sk_psock_parser *parser = &psock->parser;
890
891 if (!parser->enabled)
892 return;
893
894 sk->sk_data_ready = parser->saved_data_ready;
895 parser->saved_data_ready = NULL;
896 strp_stop(&parser->strp);
897 parser->enabled = false;
898}