1/*
2 * af_alg: User-space algorithm interface
3 *
4 * This file provides the user-space API for algorithms.
5 *
6 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15#include <linux/atomic.h>
16#include <crypto/if_alg.h>
17#include <linux/crypto.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/list.h>
21#include <linux/module.h>
22#include <linux/net.h>
23#include <linux/rwsem.h>
24#include <linux/sched/signal.h>
25#include <linux/security.h>
26
27struct alg_type_list {
28 const struct af_alg_type *type;
29 struct list_head list;
30};
31
32static atomic_long_t alg_memory_allocated;
33
34static struct proto alg_proto = {
35 .name = "ALG",
36 .owner = THIS_MODULE,
37 .memory_allocated = &alg_memory_allocated,
38 .obj_size = sizeof(struct alg_sock),
39};
40
41static LIST_HEAD(alg_types);
42static DECLARE_RWSEM(alg_types_sem);
43
44static const struct af_alg_type *alg_get_type(const char *name)
45{
46 const struct af_alg_type *type = ERR_PTR(-ENOENT);
47 struct alg_type_list *node;
48
49 down_read(&alg_types_sem);
50 list_for_each_entry(node, &alg_types, list) {
51 if (strcmp(node->type->name, name))
52 continue;
53
54 if (try_module_get(node->type->owner))
55 type = node->type;
56 break;
57 }
58 up_read(&alg_types_sem);
59
60 return type;
61}
62
63int af_alg_register_type(const struct af_alg_type *type)
64{
65 struct alg_type_list *node;
66 int err = -EEXIST;
67
68 down_write(&alg_types_sem);
69 list_for_each_entry(node, &alg_types, list) {
70 if (!strcmp(node->type->name, type->name))
71 goto unlock;
72 }
73
74 node = kmalloc(sizeof(*node), GFP_KERNEL);
75 err = -ENOMEM;
76 if (!node)
77 goto unlock;
78
79 type->ops->owner = THIS_MODULE;
80 if (type->ops_nokey)
81 type->ops_nokey->owner = THIS_MODULE;
82 node->type = type;
83 list_add(&node->list, &alg_types);
84 err = 0;
85
86unlock:
87 up_write(&alg_types_sem);
88
89 return err;
90}
91EXPORT_SYMBOL_GPL(af_alg_register_type);
92
93int af_alg_unregister_type(const struct af_alg_type *type)
94{
95 struct alg_type_list *node;
96 int err = -ENOENT;
97
98 down_write(&alg_types_sem);
99 list_for_each_entry(node, &alg_types, list) {
100 if (strcmp(node->type->name, type->name))
101 continue;
102
103 list_del(&node->list);
104 kfree(node);
105 err = 0;
106 break;
107 }
108 up_write(&alg_types_sem);
109
110 return err;
111}
112EXPORT_SYMBOL_GPL(af_alg_unregister_type);
113
114static void alg_do_release(const struct af_alg_type *type, void *private)
115{
116 if (!type)
117 return;
118
119 type->release(private);
120 module_put(type->owner);
121}
122
123int af_alg_release(struct socket *sock)
124{
125 if (sock->sk) {
126 sock_put(sock->sk);
127 sock->sk = NULL;
128 }
129 return 0;
130}
131EXPORT_SYMBOL_GPL(af_alg_release);
132
133void af_alg_release_parent(struct sock *sk)
134{
135 struct alg_sock *ask = alg_sk(sk);
136 unsigned int nokey = ask->nokey_refcnt;
137 bool last = nokey && !ask->refcnt;
138
139 sk = ask->parent;
140 ask = alg_sk(sk);
141
142 lock_sock(sk);
143 ask->nokey_refcnt -= nokey;
144 if (!last)
145 last = !--ask->refcnt;
146 release_sock(sk);
147
148 if (last)
149 sock_put(sk);
150}
151EXPORT_SYMBOL_GPL(af_alg_release_parent);
152
153static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
154{
155 const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
156 struct sock *sk = sock->sk;
157 struct alg_sock *ask = alg_sk(sk);
158 struct sockaddr_alg *sa = (void *)uaddr;
159 const struct af_alg_type *type;
160 void *private;
161 int err;
162
163 if (sock->state == SS_CONNECTED)
164 return -EINVAL;
165
166 if (addr_len < sizeof(*sa))
167 return -EINVAL;
168
169 /* If caller uses non-allowed flag, return error. */
170 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
171 return -EINVAL;
172
173 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
174 sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
175
176 type = alg_get_type(sa->salg_type);
177 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
178 request_module("algif-%s", sa->salg_type);
179 type = alg_get_type(sa->salg_type);
180 }
181
182 if (IS_ERR(type))
183 return PTR_ERR(type);
184
185 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
186 if (IS_ERR(private)) {
187 module_put(type->owner);
188 return PTR_ERR(private);
189 }
190
191 err = -EBUSY;
192 lock_sock(sk);
193 if (ask->refcnt | ask->nokey_refcnt)
194 goto unlock;
195
196 swap(ask->type, type);
197 swap(ask->private, private);
198
199 err = 0;
200
201unlock:
202 release_sock(sk);
203
204 alg_do_release(type, private);
205
206 return err;
207}
208
209static int alg_setkey(struct sock *sk, char __user *ukey,
210 unsigned int keylen)
211{
212 struct alg_sock *ask = alg_sk(sk);
213 const struct af_alg_type *type = ask->type;
214 u8 *key;
215 int err;
216
217 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
218 if (!key)
219 return -ENOMEM;
220
221 err = -EFAULT;
222 if (copy_from_user(key, ukey, keylen))
223 goto out;
224
225 err = type->setkey(ask->private, key, keylen);
226
227out:
228 sock_kzfree_s(sk, key, keylen);
229
230 return err;
231}
232
233static int alg_setsockopt(struct socket *sock, int level, int optname,
234 char __user *optval, unsigned int optlen)
235{
236 struct sock *sk = sock->sk;
237 struct alg_sock *ask = alg_sk(sk);
238 const struct af_alg_type *type;
239 int err = -EBUSY;
240
241 lock_sock(sk);
242 if (ask->refcnt)
243 goto unlock;
244
245 type = ask->type;
246
247 err = -ENOPROTOOPT;
248 if (level != SOL_ALG || !type)
249 goto unlock;
250
251 switch (optname) {
252 case ALG_SET_KEY:
253 if (sock->state == SS_CONNECTED)
254 goto unlock;
255 if (!type->setkey)
256 goto unlock;
257
258 err = alg_setkey(sk, optval, optlen);
259 break;
260 case ALG_SET_AEAD_AUTHSIZE:
261 if (sock->state == SS_CONNECTED)
262 goto unlock;
263 if (!type->setauthsize)
264 goto unlock;
265 err = type->setauthsize(ask->private, optlen);
266 }
267
268unlock:
269 release_sock(sk);
270
271 return err;
272}
273
274int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern)
275{
276 struct alg_sock *ask = alg_sk(sk);
277 const struct af_alg_type *type;
278 struct sock *sk2;
279 unsigned int nokey;
280 int err;
281
282 lock_sock(sk);
283 type = ask->type;
284
285 err = -EINVAL;
286 if (!type)
287 goto unlock;
288
289 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, kern);
290 err = -ENOMEM;
291 if (!sk2)
292 goto unlock;
293
294 sock_init_data(newsock, sk2);
295 security_sock_graft(sk2, newsock);
296 security_sk_clone(sk, sk2);
297
298 err = type->accept(ask->private, sk2);
299
300 nokey = err == -ENOKEY;
301 if (nokey && type->accept_nokey)
302 err = type->accept_nokey(ask->private, sk2);
303
304 if (err)
305 goto unlock;
306
307 if (nokey || !ask->refcnt++)
308 sock_hold(sk);
309 ask->nokey_refcnt += nokey;
310 alg_sk(sk2)->parent = sk;
311 alg_sk(sk2)->type = type;
312 alg_sk(sk2)->nokey_refcnt = nokey;
313
314 newsock->ops = type->ops;
315 newsock->state = SS_CONNECTED;
316
317 if (nokey)
318 newsock->ops = type->ops_nokey;
319
320 err = 0;
321
322unlock:
323 release_sock(sk);
324
325 return err;
326}
327EXPORT_SYMBOL_GPL(af_alg_accept);
328
329static int alg_accept(struct socket *sock, struct socket *newsock, int flags,
330 bool kern)
331{
332 return af_alg_accept(sock->sk, newsock, kern);
333}
334
335static const struct proto_ops alg_proto_ops = {
336 .family = PF_ALG,
337 .owner = THIS_MODULE,
338
339 .connect = sock_no_connect,
340 .socketpair = sock_no_socketpair,
341 .getname = sock_no_getname,
342 .ioctl = sock_no_ioctl,
343 .listen = sock_no_listen,
344 .shutdown = sock_no_shutdown,
345 .getsockopt = sock_no_getsockopt,
346 .mmap = sock_no_mmap,
347 .sendpage = sock_no_sendpage,
348 .sendmsg = sock_no_sendmsg,
349 .recvmsg = sock_no_recvmsg,
350
351 .bind = alg_bind,
352 .release = af_alg_release,
353 .setsockopt = alg_setsockopt,
354 .accept = alg_accept,
355};
356
357static void alg_sock_destruct(struct sock *sk)
358{
359 struct alg_sock *ask = alg_sk(sk);
360
361 alg_do_release(ask->type, ask->private);
362}
363
364static int alg_create(struct net *net, struct socket *sock, int protocol,
365 int kern)
366{
367 struct sock *sk;
368 int err;
369
370 if (sock->type != SOCK_SEQPACKET)
371 return -ESOCKTNOSUPPORT;
372 if (protocol != 0)
373 return -EPROTONOSUPPORT;
374
375 err = -ENOMEM;
376 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
377 if (!sk)
378 goto out;
379
380 sock->ops = &alg_proto_ops;
381 sock_init_data(sock, sk);
382
383 sk->sk_destruct = alg_sock_destruct;
384
385 return 0;
386out:
387 return err;
388}
389
390static const struct net_proto_family alg_family = {
391 .family = PF_ALG,
392 .create = alg_create,
393 .owner = THIS_MODULE,
394};
395
396int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
397{
398 size_t off;
399 ssize_t n;
400 int npages, i;
401
402 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
403 if (n < 0)
404 return n;
405
406 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
407 if (WARN_ON(npages == 0))
408 return -EINVAL;
409 /* Add one extra for linking */
410 sg_init_table(sgl->sg, npages + 1);
411
412 for (i = 0, len = n; i < npages; i++) {
413 int plen = min_t(int, len, PAGE_SIZE - off);
414
415 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
416
417 off = 0;
418 len -= plen;
419 }
420 sg_mark_end(sgl->sg + npages - 1);
421 sgl->npages = npages;
422
423 return n;
424}
425EXPORT_SYMBOL_GPL(af_alg_make_sg);
426
427static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
428 struct af_alg_sgl *sgl_new)
429{
430 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
431 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
432}
433
434void af_alg_free_sg(struct af_alg_sgl *sgl)
435{
436 int i;
437
438 for (i = 0; i < sgl->npages; i++)
439 put_page(sgl->pages[i]);
440}
441EXPORT_SYMBOL_GPL(af_alg_free_sg);
442
443static int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
444{
445 struct cmsghdr *cmsg;
446
447 for_each_cmsghdr(cmsg, msg) {
448 if (!CMSG_OK(msg, cmsg))
449 return -EINVAL;
450 if (cmsg->cmsg_level != SOL_ALG)
451 continue;
452
453 switch (cmsg->cmsg_type) {
454 case ALG_SET_IV:
455 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
456 return -EINVAL;
457 con->iv = (void *)CMSG_DATA(cmsg);
458 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
459 sizeof(*con->iv)))
460 return -EINVAL;
461 break;
462
463 case ALG_SET_OP:
464 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
465 return -EINVAL;
466 con->op = *(u32 *)CMSG_DATA(cmsg);
467 break;
468
469 case ALG_SET_AEAD_ASSOCLEN:
470 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
471 return -EINVAL;
472 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
473 break;
474
475 default:
476 return -EINVAL;
477 }
478 }
479
480 return 0;
481}
482
483/**
484 * af_alg_alloc_tsgl - allocate the TX SGL
485 *
486 * @sk socket of connection to user space
487 * @return: 0 upon success, < 0 upon error
488 */
489static int af_alg_alloc_tsgl(struct sock *sk)
490{
491 struct alg_sock *ask = alg_sk(sk);
492 struct af_alg_ctx *ctx = ask->private;
493 struct af_alg_tsgl *sgl;
494 struct scatterlist *sg = NULL;
495
496 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
497 if (!list_empty(&ctx->tsgl_list))
498 sg = sgl->sg;
499
500 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
501 sgl = sock_kmalloc(sk,
502 struct_size(sgl, sg, (MAX_SGL_ENTS + 1)),
503 GFP_KERNEL);
504 if (!sgl)
505 return -ENOMEM;
506
507 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
508 sgl->cur = 0;
509
510 if (sg)
511 sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
512
513 list_add_tail(&sgl->list, &ctx->tsgl_list);
514 }
515
516 return 0;
517}
518
519/**
520 * aead_count_tsgl - Count number of TX SG entries
521 *
522 * The counting starts from the beginning of the SGL to @bytes. If
523 * an offset is provided, the counting of the SG entries starts at the offset.
524 *
525 * @sk socket of connection to user space
526 * @bytes Count the number of SG entries holding given number of bytes.
527 * @offset Start the counting of SG entries from the given offset.
528 * @return Number of TX SG entries found given the constraints
529 */
530unsigned int af_alg_count_tsgl(struct sock *sk, size_t bytes, size_t offset)
531{
532 const struct alg_sock *ask = alg_sk(sk);
533 const struct af_alg_ctx *ctx = ask->private;
534 const struct af_alg_tsgl *sgl;
535 unsigned int i;
536 unsigned int sgl_count = 0;
537
538 if (!bytes)
539 return 0;
540
541 list_for_each_entry(sgl, &ctx->tsgl_list, list) {
542 const struct scatterlist *sg = sgl->sg;
543
544 for (i = 0; i < sgl->cur; i++) {
545 size_t bytes_count;
546
547 /* Skip offset */
548 if (offset >= sg[i].length) {
549 offset -= sg[i].length;
550 bytes -= sg[i].length;
551 continue;
552 }
553
554 bytes_count = sg[i].length - offset;
555
556 offset = 0;
557 sgl_count++;
558
559 /* If we have seen requested number of bytes, stop */
560 if (bytes_count >= bytes)
561 return sgl_count;
562
563 bytes -= bytes_count;
564 }
565 }
566
567 return sgl_count;
568}
569EXPORT_SYMBOL_GPL(af_alg_count_tsgl);
570
571/**
572 * aead_pull_tsgl - Release the specified buffers from TX SGL
573 *
574 * If @dst is non-null, reassign the pages to dst. The caller must release
575 * the pages. If @dst_offset is given only reassign the pages to @dst starting
576 * at the @dst_offset (byte). The caller must ensure that @dst is large
577 * enough (e.g. by using af_alg_count_tsgl with the same offset).
578 *
579 * @sk socket of connection to user space
580 * @used Number of bytes to pull from TX SGL
581 * @dst If non-NULL, buffer is reassigned to dst SGL instead of releasing. The
582 * caller must release the buffers in dst.
583 * @dst_offset Reassign the TX SGL from given offset. All buffers before
584 * reaching the offset is released.
585 */
586void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
587 size_t dst_offset)
588{
589 struct alg_sock *ask = alg_sk(sk);
590 struct af_alg_ctx *ctx = ask->private;
591 struct af_alg_tsgl *sgl;
592 struct scatterlist *sg;
593 unsigned int i, j = 0;
594
595 while (!list_empty(&ctx->tsgl_list)) {
596 sgl = list_first_entry(&ctx->tsgl_list, struct af_alg_tsgl,
597 list);
598 sg = sgl->sg;
599
600 for (i = 0; i < sgl->cur; i++) {
601 size_t plen = min_t(size_t, used, sg[i].length);
602 struct page *page = sg_page(sg + i);
603
604 if (!page)
605 continue;
606
607 /*
608 * Assumption: caller created af_alg_count_tsgl(len)
609 * SG entries in dst.
610 */
611 if (dst) {
612 if (dst_offset >= plen) {
613 /* discard page before offset */
614 dst_offset -= plen;
615 } else {
616 /* reassign page to dst after offset */
617 get_page(page);
618 sg_set_page(dst + j, page,
619 plen - dst_offset,
620 sg[i].offset + dst_offset);
621 dst_offset = 0;
622 j++;
623 }
624 }
625
626 sg[i].length -= plen;
627 sg[i].offset += plen;
628
629 used -= plen;
630 ctx->used -= plen;
631
632 if (sg[i].length)
633 return;
634
635 put_page(page);
636 sg_assign_page(sg + i, NULL);
637 }
638
639 list_del(&sgl->list);
640 sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
641 }
642
643 if (!ctx->used)
644 ctx->merge = 0;
645}
646EXPORT_SYMBOL_GPL(af_alg_pull_tsgl);
647
648/**
649 * af_alg_free_areq_sgls - Release TX and RX SGLs of the request
650 *
651 * @areq Request holding the TX and RX SGL
652 */
653static void af_alg_free_areq_sgls(struct af_alg_async_req *areq)
654{
655 struct sock *sk = areq->sk;
656 struct alg_sock *ask = alg_sk(sk);
657 struct af_alg_ctx *ctx = ask->private;
658 struct af_alg_rsgl *rsgl, *tmp;
659 struct scatterlist *tsgl;
660 struct scatterlist *sg;
661 unsigned int i;
662
663 list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
664 atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
665 af_alg_free_sg(&rsgl->sgl);
666 list_del(&rsgl->list);
667 if (rsgl != &areq->first_rsgl)
668 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
669 }
670
671 tsgl = areq->tsgl;
672 if (tsgl) {
673 for_each_sg(tsgl, sg, areq->tsgl_entries, i) {
674 if (!sg_page(sg))
675 continue;
676 put_page(sg_page(sg));
677 }
678
679 sock_kfree_s(sk, tsgl, areq->tsgl_entries * sizeof(*tsgl));
680 }
681}
682
683/**
684 * af_alg_wait_for_wmem - wait for availability of writable memory
685 *
686 * @sk socket of connection to user space
687 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
688 * @return 0 when writable memory is available, < 0 upon error
689 */
690static int af_alg_wait_for_wmem(struct sock *sk, unsigned int flags)
691{
692 DEFINE_WAIT_FUNC(wait, woken_wake_function);
693 int err = -ERESTARTSYS;
694 long timeout;
695
696 if (flags & MSG_DONTWAIT)
697 return -EAGAIN;
698
699 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
700
701 add_wait_queue(sk_sleep(sk), &wait);
702 for (;;) {
703 if (signal_pending(current))
704 break;
705 timeout = MAX_SCHEDULE_TIMEOUT;
706 if (sk_wait_event(sk, &timeout, af_alg_writable(sk), &wait)) {
707 err = 0;
708 break;
709 }
710 }
711 remove_wait_queue(sk_sleep(sk), &wait);
712
713 return err;
714}
715
716/**
717 * af_alg_wmem_wakeup - wakeup caller when writable memory is available
718 *
719 * @sk socket of connection to user space
720 */
721void af_alg_wmem_wakeup(struct sock *sk)
722{
723 struct socket_wq *wq;
724
725 if (!af_alg_writable(sk))
726 return;
727
728 rcu_read_lock();
729 wq = rcu_dereference(sk->sk_wq);
730 if (skwq_has_sleeper(wq))
731 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN |
732 EPOLLRDNORM |
733 EPOLLRDBAND);
734 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
735 rcu_read_unlock();
736}
737EXPORT_SYMBOL_GPL(af_alg_wmem_wakeup);
738
739/**
740 * af_alg_wait_for_data - wait for availability of TX data
741 *
742 * @sk socket of connection to user space
743 * @flags If MSG_DONTWAIT is set, then only report if function would sleep
744 * @return 0 when writable memory is available, < 0 upon error
745 */
746int af_alg_wait_for_data(struct sock *sk, unsigned flags)
747{
748 DEFINE_WAIT_FUNC(wait, woken_wake_function);
749 struct alg_sock *ask = alg_sk(sk);
750 struct af_alg_ctx *ctx = ask->private;
751 long timeout;
752 int err = -ERESTARTSYS;
753
754 if (flags & MSG_DONTWAIT)
755 return -EAGAIN;
756
757 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
758
759 add_wait_queue(sk_sleep(sk), &wait);
760 for (;;) {
761 if (signal_pending(current))
762 break;
763 timeout = MAX_SCHEDULE_TIMEOUT;
764 if (sk_wait_event(sk, &timeout, (ctx->used || !ctx->more),
765 &wait)) {
766 err = 0;
767 break;
768 }
769 }
770 remove_wait_queue(sk_sleep(sk), &wait);
771
772 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
773
774 return err;
775}
776EXPORT_SYMBOL_GPL(af_alg_wait_for_data);
777
778/**
779 * af_alg_data_wakeup - wakeup caller when new data can be sent to kernel
780 *
781 * @sk socket of connection to user space
782 */
783static void af_alg_data_wakeup(struct sock *sk)
784{
785 struct alg_sock *ask = alg_sk(sk);
786 struct af_alg_ctx *ctx = ask->private;
787 struct socket_wq *wq;
788
789 if (!ctx->used)
790 return;
791
792 rcu_read_lock();
793 wq = rcu_dereference(sk->sk_wq);
794 if (skwq_has_sleeper(wq))
795 wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
796 EPOLLRDNORM |
797 EPOLLRDBAND);
798 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
799 rcu_read_unlock();
800}
801
802/**
803 * af_alg_sendmsg - implementation of sendmsg system call handler
804 *
805 * The sendmsg system call handler obtains the user data and stores it
806 * in ctx->tsgl_list. This implies allocation of the required numbers of
807 * struct af_alg_tsgl.
808 *
809 * In addition, the ctx is filled with the information sent via CMSG.
810 *
811 * @sock socket of connection to user space
812 * @msg message from user space
813 * @size size of message from user space
814 * @ivsize the size of the IV for the cipher operation to verify that the
815 * user-space-provided IV has the right size
816 * @return the number of copied data upon success, < 0 upon error
817 */
818int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
819 unsigned int ivsize)
820{
821 struct sock *sk = sock->sk;
822 struct alg_sock *ask = alg_sk(sk);
823 struct af_alg_ctx *ctx = ask->private;
824 struct af_alg_tsgl *sgl;
825 struct af_alg_control con = {};
826 long copied = 0;
827 bool enc = 0;
828 bool init = 0;
829 int err = 0;
830
831 if (msg->msg_controllen) {
832 err = af_alg_cmsg_send(msg, &con);
833 if (err)
834 return err;
835
836 init = 1;
837 switch (con.op) {
838 case ALG_OP_ENCRYPT:
839 enc = 1;
840 break;
841 case ALG_OP_DECRYPT:
842 enc = 0;
843 break;
844 default:
845 return -EINVAL;
846 }
847
848 if (con.iv && con.iv->ivlen != ivsize)
849 return -EINVAL;
850 }
851
852 lock_sock(sk);
853 if (!ctx->more && ctx->used) {
854 err = -EINVAL;
855 goto unlock;
856 }
857
858 if (init) {
859 ctx->enc = enc;
860 if (con.iv)
861 memcpy(ctx->iv, con.iv->iv, ivsize);
862
863 ctx->aead_assoclen = con.aead_assoclen;
864 }
865
866 while (size) {
867 struct scatterlist *sg;
868 size_t len = size;
869 size_t plen;
870
871 /* use the existing memory in an allocated page */
872 if (ctx->merge) {
873 sgl = list_entry(ctx->tsgl_list.prev,
874 struct af_alg_tsgl, list);
875 sg = sgl->sg + sgl->cur - 1;
876 len = min_t(size_t, len,
877 PAGE_SIZE - sg->offset - sg->length);
878
879 err = memcpy_from_msg(page_address(sg_page(sg)) +
880 sg->offset + sg->length,
881 msg, len);
882 if (err)
883 goto unlock;
884
885 sg->length += len;
886 ctx->merge = (sg->offset + sg->length) &
887 (PAGE_SIZE - 1);
888
889 ctx->used += len;
890 copied += len;
891 size -= len;
892 continue;
893 }
894
895 if (!af_alg_writable(sk)) {
896 err = af_alg_wait_for_wmem(sk, msg->msg_flags);
897 if (err)
898 goto unlock;
899 }
900
901 /* allocate a new page */
902 len = min_t(unsigned long, len, af_alg_sndbuf(sk));
903
904 err = af_alg_alloc_tsgl(sk);
905 if (err)
906 goto unlock;
907
908 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl,
909 list);
910 sg = sgl->sg;
911 if (sgl->cur)
912 sg_unmark_end(sg + sgl->cur - 1);
913
914 do {
915 unsigned int i = sgl->cur;
916
917 plen = min_t(size_t, len, PAGE_SIZE);
918
919 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
920 if (!sg_page(sg + i)) {
921 err = -ENOMEM;
922 goto unlock;
923 }
924
925 err = memcpy_from_msg(page_address(sg_page(sg + i)),
926 msg, plen);
927 if (err) {
928 __free_page(sg_page(sg + i));
929 sg_assign_page(sg + i, NULL);
930 goto unlock;
931 }
932
933 sg[i].length = plen;
934 len -= plen;
935 ctx->used += plen;
936 copied += plen;
937 size -= plen;
938 sgl->cur++;
939 } while (len && sgl->cur < MAX_SGL_ENTS);
940
941 if (!size)
942 sg_mark_end(sg + sgl->cur - 1);
943
944 ctx->merge = plen & (PAGE_SIZE - 1);
945 }
946
947 err = 0;
948
949 ctx->more = msg->msg_flags & MSG_MORE;
950
951unlock:
952 af_alg_data_wakeup(sk);
953 release_sock(sk);
954
955 return copied ?: err;
956}
957EXPORT_SYMBOL_GPL(af_alg_sendmsg);
958
959/**
960 * af_alg_sendpage - sendpage system call handler
961 *
962 * This is a generic implementation of sendpage to fill ctx->tsgl_list.
963 */
964ssize_t af_alg_sendpage(struct socket *sock, struct page *page,
965 int offset, size_t size, int flags)
966{
967 struct sock *sk = sock->sk;
968 struct alg_sock *ask = alg_sk(sk);
969 struct af_alg_ctx *ctx = ask->private;
970 struct af_alg_tsgl *sgl;
971 int err = -EINVAL;
972
973 if (flags & MSG_SENDPAGE_NOTLAST)
974 flags |= MSG_MORE;
975
976 lock_sock(sk);
977 if (!ctx->more && ctx->used)
978 goto unlock;
979
980 if (!size)
981 goto done;
982
983 if (!af_alg_writable(sk)) {
984 err = af_alg_wait_for_wmem(sk, flags);
985 if (err)
986 goto unlock;
987 }
988
989 err = af_alg_alloc_tsgl(sk);
990 if (err)
991 goto unlock;
992
993 ctx->merge = 0;
994 sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list);
995
996 if (sgl->cur)
997 sg_unmark_end(sgl->sg + sgl->cur - 1);
998
999 sg_mark_end(sgl->sg + sgl->cur);
1000
1001 get_page(page);
1002 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
1003 sgl->cur++;
1004 ctx->used += size;
1005
1006done:
1007 ctx->more = flags & MSG_MORE;
1008
1009unlock:
1010 af_alg_data_wakeup(sk);
1011 release_sock(sk);
1012
1013 return err ?: size;
1014}
1015EXPORT_SYMBOL_GPL(af_alg_sendpage);
1016
1017/**
1018 * af_alg_free_resources - release resources required for crypto request
1019 */
1020void af_alg_free_resources(struct af_alg_async_req *areq)
1021{
1022 struct sock *sk = areq->sk;
1023
1024 af_alg_free_areq_sgls(areq);
1025 sock_kfree_s(sk, areq, areq->areqlen);
1026}
1027EXPORT_SYMBOL_GPL(af_alg_free_resources);
1028
1029/**
1030 * af_alg_async_cb - AIO callback handler
1031 *
1032 * This handler cleans up the struct af_alg_async_req upon completion of the
1033 * AIO operation.
1034 *
1035 * The number of bytes to be generated with the AIO operation must be set
1036 * in areq->outlen before the AIO callback handler is invoked.
1037 */
1038void af_alg_async_cb(struct crypto_async_request *_req, int err)
1039{
1040 struct af_alg_async_req *areq = _req->data;
1041 struct sock *sk = areq->sk;
1042 struct kiocb *iocb = areq->iocb;
1043 unsigned int resultlen;
1044
1045 /* Buffer size written by crypto operation. */
1046 resultlen = areq->outlen;
1047
1048 af_alg_free_resources(areq);
1049 sock_put(sk);
1050
1051 iocb->ki_complete(iocb, err ? err : resultlen, 0);
1052}
1053EXPORT_SYMBOL_GPL(af_alg_async_cb);
1054
1055/**
1056 * af_alg_poll - poll system call handler
1057 */
1058__poll_t af_alg_poll(struct file *file, struct socket *sock,
1059 poll_table *wait)
1060{
1061 struct sock *sk = sock->sk;
1062 struct alg_sock *ask = alg_sk(sk);
1063 struct af_alg_ctx *ctx = ask->private;
1064 __poll_t mask;
1065
1066 sock_poll_wait(file, sock, wait);
1067 mask = 0;
1068
1069 if (!ctx->more || ctx->used)
1070 mask |= EPOLLIN | EPOLLRDNORM;
1071
1072 if (af_alg_writable(sk))
1073 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
1074
1075 return mask;
1076}
1077EXPORT_SYMBOL_GPL(af_alg_poll);
1078
1079/**
1080 * af_alg_alloc_areq - allocate struct af_alg_async_req
1081 *
1082 * @sk socket of connection to user space
1083 * @areqlen size of struct af_alg_async_req + crypto_*_reqsize
1084 * @return allocated data structure or ERR_PTR upon error
1085 */
1086struct af_alg_async_req *af_alg_alloc_areq(struct sock *sk,
1087 unsigned int areqlen)
1088{
1089 struct af_alg_async_req *areq = sock_kmalloc(sk, areqlen, GFP_KERNEL);
1090
1091 if (unlikely(!areq))
1092 return ERR_PTR(-ENOMEM);
1093
1094 areq->areqlen = areqlen;
1095 areq->sk = sk;
1096 areq->last_rsgl = NULL;
1097 INIT_LIST_HEAD(&areq->rsgl_list);
1098 areq->tsgl = NULL;
1099 areq->tsgl_entries = 0;
1100
1101 return areq;
1102}
1103EXPORT_SYMBOL_GPL(af_alg_alloc_areq);
1104
1105/**
1106 * af_alg_get_rsgl - create the RX SGL for the output data from the crypto
1107 * operation
1108 *
1109 * @sk socket of connection to user space
1110 * @msg user space message
1111 * @flags flags used to invoke recvmsg with
1112 * @areq instance of the cryptographic request that will hold the RX SGL
1113 * @maxsize maximum number of bytes to be pulled from user space
1114 * @outlen number of bytes in the RX SGL
1115 * @return 0 on success, < 0 upon error
1116 */
1117int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
1118 struct af_alg_async_req *areq, size_t maxsize,
1119 size_t *outlen)
1120{
1121 struct alg_sock *ask = alg_sk(sk);
1122 struct af_alg_ctx *ctx = ask->private;
1123 size_t len = 0;
1124
1125 while (maxsize > len && msg_data_left(msg)) {
1126 struct af_alg_rsgl *rsgl;
1127 size_t seglen;
1128 int err;
1129
1130 /* limit the amount of readable buffers */
1131 if (!af_alg_readable(sk))
1132 break;
1133
1134 seglen = min_t(size_t, (maxsize - len),
1135 msg_data_left(msg));
1136
1137 if (list_empty(&areq->rsgl_list)) {
1138 rsgl = &areq->first_rsgl;
1139 } else {
1140 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
1141 if (unlikely(!rsgl))
1142 return -ENOMEM;
1143 }
1144
1145 rsgl->sgl.npages = 0;
1146 list_add_tail(&rsgl->list, &areq->rsgl_list);
1147
1148 /* make one iovec available as scatterlist */
1149 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
1150 if (err < 0) {
1151 rsgl->sg_num_bytes = 0;
1152 return err;
1153 }
1154
1155 /* chain the new scatterlist with previous one */
1156 if (areq->last_rsgl)
1157 af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
1158
1159 areq->last_rsgl = rsgl;
1160 len += err;
1161 atomic_add(err, &ctx->rcvused);
1162 rsgl->sg_num_bytes = err;
1163 iov_iter_advance(&msg->msg_iter, err);
1164 }
1165
1166 *outlen = len;
1167 return 0;
1168}
1169EXPORT_SYMBOL_GPL(af_alg_get_rsgl);
1170
1171static int __init af_alg_init(void)
1172{
1173 int err = proto_register(&alg_proto, 0);
1174
1175 if (err)
1176 goto out;
1177
1178 err = sock_register(&alg_family);
1179 if (err != 0)
1180 goto out_unregister_proto;
1181
1182out:
1183 return err;
1184
1185out_unregister_proto:
1186 proto_unregister(&alg_proto);
1187 goto out;
1188}
1189
1190static void __exit af_alg_exit(void)
1191{
1192 sock_unregister(PF_ALG);
1193 proto_unregister(&alg_proto);
1194}
1195
1196module_init(af_alg_init);
1197module_exit(af_alg_exit);
1198MODULE_LICENSE("GPL");
1199MODULE_ALIAS_NETPROTO(AF_ALG);
1200