2 * algif_skcipher: User-space interface for skcipher algorithms
4 * This file provides the user-space API for symmetric key ciphers.
6 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
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)
15 #include <crypto/scatterwalk.h>
16 #include <crypto/skcipher.h>
17 #include <crypto/if_alg.h>
18 #include <linux/init.h>
19 #include <linux/list.h>
20 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/net.h>
26 struct skcipher_sg_list {
27 struct list_head list;
31 struct scatterlist sg[0];
35 struct crypto_ablkcipher *skcipher;
40 struct list_head tsgl;
41 struct af_alg_sgl rsgl;
45 struct af_alg_completion completion;
54 struct ablkcipher_request req;
57 #define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
58 sizeof(struct scatterlist) - 1)
60 static inline int skcipher_sndbuf(struct sock *sk)
62 struct alg_sock *ask = alg_sk(sk);
63 struct skcipher_ctx *ctx = ask->private;
65 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
69 static inline bool skcipher_writable(struct sock *sk)
71 return PAGE_SIZE <= skcipher_sndbuf(sk);
74 static int skcipher_alloc_sgl(struct sock *sk)
76 struct alg_sock *ask = alg_sk(sk);
77 struct skcipher_ctx *ctx = ask->private;
78 struct skcipher_sg_list *sgl;
79 struct scatterlist *sg = NULL;
81 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
82 if (!list_empty(&ctx->tsgl))
85 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
86 sgl = sock_kmalloc(sk, sizeof(*sgl) +
87 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
92 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
96 scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
98 list_add_tail(&sgl->list, &ctx->tsgl);
104 static void skcipher_pull_sgl(struct sock *sk, int used)
106 struct alg_sock *ask = alg_sk(sk);
107 struct skcipher_ctx *ctx = ask->private;
108 struct skcipher_sg_list *sgl;
109 struct scatterlist *sg;
112 while (!list_empty(&ctx->tsgl)) {
113 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
117 for (i = 0; i < sgl->cur; i++) {
118 int plen = min_t(int, used, sg[i].length);
120 if (!sg_page(sg + i))
123 sg[i].length -= plen;
124 sg[i].offset += plen;
132 put_page(sg_page(sg + i));
133 sg_assign_page(sg + i, NULL);
136 list_del(&sgl->list);
137 sock_kfree_s(sk, sgl,
138 sizeof(*sgl) + sizeof(sgl->sg[0]) *
146 static void skcipher_free_sgl(struct sock *sk)
148 struct alg_sock *ask = alg_sk(sk);
149 struct skcipher_ctx *ctx = ask->private;
151 skcipher_pull_sgl(sk, ctx->used);
154 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
158 int err = -ERESTARTSYS;
160 if (flags & MSG_DONTWAIT)
163 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
166 if (signal_pending(current))
168 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
169 timeout = MAX_SCHEDULE_TIMEOUT;
170 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
175 finish_wait(sk_sleep(sk), &wait);
180 static void skcipher_wmem_wakeup(struct sock *sk)
182 struct socket_wq *wq;
184 if (!skcipher_writable(sk))
188 wq = rcu_dereference(sk->sk_wq);
189 if (wq_has_sleeper(wq))
190 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
193 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
197 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
199 struct alg_sock *ask = alg_sk(sk);
200 struct skcipher_ctx *ctx = ask->private;
203 int err = -ERESTARTSYS;
205 if (flags & MSG_DONTWAIT) {
209 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
212 if (signal_pending(current))
214 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
215 timeout = MAX_SCHEDULE_TIMEOUT;
216 if (sk_wait_event(sk, &timeout, ctx->used)) {
221 finish_wait(sk_sleep(sk), &wait);
223 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
228 static void skcipher_data_wakeup(struct sock *sk)
230 struct alg_sock *ask = alg_sk(sk);
231 struct skcipher_ctx *ctx = ask->private;
232 struct socket_wq *wq;
238 wq = rcu_dereference(sk->sk_wq);
239 if (wq_has_sleeper(wq))
240 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
243 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
247 static int skcipher_sendmsg(struct kiocb *unused, struct socket *sock,
248 struct msghdr *msg, size_t size)
250 struct sock *sk = sock->sk;
251 struct alg_sock *ask = alg_sk(sk);
252 struct sock *psk = ask->parent;
253 struct alg_sock *pask = alg_sk(psk);
254 struct skcipher_ctx *ctx = ask->private;
255 struct ablkcipher_tfm *skc = pask->private;
256 struct crypto_ablkcipher *tfm = skc->base;
257 unsigned ivsize = crypto_ablkcipher_ivsize(tfm);
258 struct skcipher_sg_list *sgl;
259 struct af_alg_control con = {};
265 if (msg->msg_controllen) {
266 err = af_alg_cmsg_send(msg, &con);
281 if (con.iv && con.iv->ivlen != ivsize)
288 if (!ctx->more && ctx->used)
294 memcpy(ctx->iv, con.iv->iv, ivsize);
298 struct scatterlist *sg;
299 unsigned long len = size;
303 sgl = list_entry(ctx->tsgl.prev,
304 struct skcipher_sg_list, list);
305 sg = sgl->sg + sgl->cur - 1;
306 len = min_t(unsigned long, len,
307 PAGE_SIZE - sg->offset - sg->length);
309 err = memcpy_fromiovec(page_address(sg_page(sg)) +
310 sg->offset + sg->length,
316 ctx->merge = (sg->offset + sg->length) &
325 if (!skcipher_writable(sk)) {
326 err = skcipher_wait_for_wmem(sk, msg->msg_flags);
331 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
333 err = skcipher_alloc_sgl(sk);
337 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
341 plen = min_t(int, len, PAGE_SIZE);
343 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
345 if (!sg_page(sg + i))
348 err = memcpy_fromiovec(page_address(sg_page(sg + i)),
351 __free_page(sg_page(sg + i));
352 sg_assign_page(sg + i, NULL);
362 } while (len && sgl->cur < MAX_SGL_ENTS);
364 ctx->merge = plen & (PAGE_SIZE - 1);
369 ctx->more = msg->msg_flags & MSG_MORE;
370 if (!ctx->more && !list_empty(&ctx->tsgl))
371 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
374 skcipher_data_wakeup(sk);
377 return copied ?: err;
380 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
381 int offset, size_t size, int flags)
383 struct sock *sk = sock->sk;
384 struct alg_sock *ask = alg_sk(sk);
385 struct skcipher_ctx *ctx = ask->private;
386 struct skcipher_sg_list *sgl;
389 if (flags & MSG_SENDPAGE_NOTLAST)
393 if (!ctx->more && ctx->used)
399 if (!skcipher_writable(sk)) {
400 err = skcipher_wait_for_wmem(sk, flags);
405 err = skcipher_alloc_sgl(sk);
410 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
413 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
418 ctx->more = flags & MSG_MORE;
419 if (!ctx->more && !list_empty(&ctx->tsgl))
420 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
423 skcipher_data_wakeup(sk);
429 static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
430 struct msghdr *msg, size_t ignored, int flags)
432 struct sock *sk = sock->sk;
433 struct alg_sock *ask = alg_sk(sk);
434 struct skcipher_ctx *ctx = ask->private;
435 unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm(
437 struct skcipher_sg_list *sgl;
438 struct scatterlist *sg;
439 unsigned long iovlen;
446 for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
448 unsigned long seglen = iov->iov_len;
449 char __user *from = iov->iov_base;
454 err = skcipher_wait_for_data(sk, flags);
459 used = min_t(unsigned long, used, seglen);
461 used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
466 if (ctx->more || used < ctx->used)
473 sgl = list_first_entry(&ctx->tsgl,
474 struct skcipher_sg_list, list);
480 ablkcipher_request_set_crypt(&ctx->req, sg,
484 err = af_alg_wait_for_completion(
486 crypto_ablkcipher_encrypt(&ctx->req) :
487 crypto_ablkcipher_decrypt(&ctx->req),
491 af_alg_free_sg(&ctx->rsgl);
499 skcipher_pull_sgl(sk, used);
506 skcipher_wmem_wakeup(sk);
509 return copied ?: err;
513 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
516 struct sock *sk = sock->sk;
517 struct alg_sock *ask = alg_sk(sk);
518 struct skcipher_ctx *ctx = ask->private;
521 sock_poll_wait(file, sk_sleep(sk), wait);
525 mask |= POLLIN | POLLRDNORM;
527 if (skcipher_writable(sk))
528 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
533 static struct proto_ops algif_skcipher_ops = {
536 .connect = sock_no_connect,
537 .socketpair = sock_no_socketpair,
538 .getname = sock_no_getname,
539 .ioctl = sock_no_ioctl,
540 .listen = sock_no_listen,
541 .shutdown = sock_no_shutdown,
542 .getsockopt = sock_no_getsockopt,
543 .mmap = sock_no_mmap,
544 .bind = sock_no_bind,
545 .accept = sock_no_accept,
546 .setsockopt = sock_no_setsockopt,
548 .release = af_alg_release,
549 .sendmsg = skcipher_sendmsg,
550 .sendpage = skcipher_sendpage,
551 .recvmsg = skcipher_recvmsg,
552 .poll = skcipher_poll,
555 static int skcipher_check_key(struct socket *sock)
559 struct alg_sock *pask;
560 struct skcipher_tfm *tfm;
561 struct sock *sk = sock->sk;
562 struct alg_sock *ask = alg_sk(sk);
569 pask = alg_sk(ask->parent);
573 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
593 static int skcipher_sendmsg_nokey(struct kiocb *unused, struct socket *sock,
594 struct msghdr *msg, size_t size)
598 err = skcipher_check_key(sock);
602 return skcipher_sendmsg(unused, sock, msg, size);
605 static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
606 int offset, size_t size, int flags)
610 err = skcipher_check_key(sock);
614 return skcipher_sendpage(sock, page, offset, size, flags);
617 static int skcipher_recvmsg_nokey(struct kiocb *unused, struct socket *sock,
618 struct msghdr *msg, size_t ignored, int flags)
622 err = skcipher_check_key(sock);
626 return skcipher_recvmsg(unused, sock, msg, ignored, flags);
629 static struct proto_ops algif_skcipher_ops_nokey = {
632 .connect = sock_no_connect,
633 .socketpair = sock_no_socketpair,
634 .getname = sock_no_getname,
635 .ioctl = sock_no_ioctl,
636 .listen = sock_no_listen,
637 .shutdown = sock_no_shutdown,
638 .getsockopt = sock_no_getsockopt,
639 .mmap = sock_no_mmap,
640 .bind = sock_no_bind,
641 .accept = sock_no_accept,
642 .setsockopt = sock_no_setsockopt,
644 .release = af_alg_release,
645 .sendmsg = skcipher_sendmsg_nokey,
646 .sendpage = skcipher_sendpage_nokey,
647 .recvmsg = skcipher_recvmsg_nokey,
648 .poll = skcipher_poll,
651 static void *skcipher_bind(const char *name, u32 type, u32 mask)
653 struct skcipher_tfm *tfm;
654 struct crypto_ablkcipher *skcipher;
656 tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
658 return ERR_PTR(-ENOMEM);
660 skcipher = crypto_alloc_ablkcipher(name, type, mask);
661 if (IS_ERR(skcipher)) {
663 return ERR_CAST(skcipher);
666 tfm->skcipher = skcipher;
671 static void skcipher_release(void *private)
673 struct skcipher_tfm *tfm = private;
675 crypto_free_ablkcipher(tfm->skcipher);
679 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
681 struct skcipher_tfm *tfm = private;
684 err = crypto_ablkcipher_setkey(tfm->skcipher, key, keylen);
690 static void skcipher_sock_destruct(struct sock *sk)
692 struct alg_sock *ask = alg_sk(sk);
693 struct skcipher_ctx *ctx = ask->private;
694 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
696 skcipher_free_sgl(sk);
697 sock_kfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
698 sock_kfree_s(sk, ctx, ctx->len);
699 af_alg_release_parent(sk);
702 static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
704 struct skcipher_ctx *ctx;
705 struct alg_sock *ask = alg_sk(sk);
706 struct skcipher_tfm *tfm = private;
707 struct crypto_ablkcipher *skcipher = tfm->skcipher;
708 unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(skcipher);
710 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
714 ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(skcipher),
717 sock_kfree_s(sk, ctx, len);
721 memset(ctx->iv, 0, crypto_ablkcipher_ivsize(skcipher));
723 INIT_LIST_HEAD(&ctx->tsgl);
729 af_alg_init_completion(&ctx->completion);
733 ablkcipher_request_set_tfm(&ctx->req, skcipher);
734 ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
735 af_alg_complete, &ctx->completion);
737 sk->sk_destruct = skcipher_sock_destruct;
742 static int skcipher_accept_parent(void *private, struct sock *sk)
744 struct skcipher_tfm *tfm = private;
746 if (!tfm->has_key && crypto_ablkcipher_has_setkey(tfm->skcipher))
749 return skcipher_accept_parent_nokey(private, sk);
752 static const struct af_alg_type algif_type_skcipher = {
753 .bind = skcipher_bind,
754 .release = skcipher_release,
755 .setkey = skcipher_setkey,
756 .accept = skcipher_accept_parent,
757 .accept_nokey = skcipher_accept_parent_nokey,
758 .ops = &algif_skcipher_ops,
759 .ops_nokey = &algif_skcipher_ops_nokey,
764 static int __init algif_skcipher_init(void)
766 return af_alg_register_type(&algif_type_skcipher);
769 static void __exit algif_skcipher_exit(void)
771 int err = af_alg_unregister_type(&algif_type_skcipher);
775 module_init(algif_skcipher_init);
776 module_exit(algif_skcipher_exit);
777 MODULE_LICENSE("GPL");