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 list_head tsgl;
36 struct af_alg_sgl rsgl;
40 struct af_alg_completion completion;
49 struct ablkcipher_request req;
52 #define MAX_SGL_ENTS ((PAGE_SIZE - sizeof(struct skcipher_sg_list)) / \
53 sizeof(struct scatterlist) - 1)
55 static inline int skcipher_sndbuf(struct sock *sk)
57 struct alg_sock *ask = alg_sk(sk);
58 struct skcipher_ctx *ctx = ask->private;
60 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
64 static inline bool skcipher_writable(struct sock *sk)
66 return PAGE_SIZE <= skcipher_sndbuf(sk);
69 static int skcipher_alloc_sgl(struct sock *sk)
71 struct alg_sock *ask = alg_sk(sk);
72 struct skcipher_ctx *ctx = ask->private;
73 struct skcipher_sg_list *sgl;
74 struct scatterlist *sg = NULL;
76 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
77 if (!list_empty(&ctx->tsgl))
80 if (!sg || sgl->cur >= MAX_SGL_ENTS) {
81 sgl = sock_kmalloc(sk, sizeof(*sgl) +
82 sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
87 sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
91 scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
93 list_add_tail(&sgl->list, &ctx->tsgl);
99 static void skcipher_pull_sgl(struct sock *sk, int used)
101 struct alg_sock *ask = alg_sk(sk);
102 struct skcipher_ctx *ctx = ask->private;
103 struct skcipher_sg_list *sgl;
104 struct scatterlist *sg;
107 while (!list_empty(&ctx->tsgl)) {
108 sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
112 for (i = 0; i < sgl->cur; i++) {
113 int plen = min_t(int, used, sg[i].length);
115 if (!sg_page(sg + i))
118 sg[i].length -= plen;
119 sg[i].offset += plen;
127 put_page(sg_page(sg + i));
128 sg_assign_page(sg + i, NULL);
131 list_del(&sgl->list);
132 sock_kfree_s(sk, sgl,
133 sizeof(*sgl) + sizeof(sgl->sg[0]) *
141 static void skcipher_free_sgl(struct sock *sk)
143 struct alg_sock *ask = alg_sk(sk);
144 struct skcipher_ctx *ctx = ask->private;
146 skcipher_pull_sgl(sk, ctx->used);
149 static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
153 int err = -ERESTARTSYS;
155 if (flags & MSG_DONTWAIT)
158 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
161 if (signal_pending(current))
163 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
164 timeout = MAX_SCHEDULE_TIMEOUT;
165 if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
170 finish_wait(sk_sleep(sk), &wait);
175 static void skcipher_wmem_wakeup(struct sock *sk)
177 struct socket_wq *wq;
179 if (!skcipher_writable(sk))
183 wq = rcu_dereference(sk->sk_wq);
184 if (wq_has_sleeper(wq))
185 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
188 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
192 static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
194 struct alg_sock *ask = alg_sk(sk);
195 struct skcipher_ctx *ctx = ask->private;
198 int err = -ERESTARTSYS;
200 if (flags & MSG_DONTWAIT) {
204 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
207 if (signal_pending(current))
209 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
210 timeout = MAX_SCHEDULE_TIMEOUT;
211 if (sk_wait_event(sk, &timeout, ctx->used)) {
216 finish_wait(sk_sleep(sk), &wait);
218 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
223 static void skcipher_data_wakeup(struct sock *sk)
225 struct alg_sock *ask = alg_sk(sk);
226 struct skcipher_ctx *ctx = ask->private;
227 struct socket_wq *wq;
233 wq = rcu_dereference(sk->sk_wq);
234 if (wq_has_sleeper(wq))
235 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
238 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
242 static int skcipher_sendmsg(struct kiocb *unused, struct socket *sock,
243 struct msghdr *msg, size_t size)
245 struct sock *sk = sock->sk;
246 struct alg_sock *ask = alg_sk(sk);
247 struct skcipher_ctx *ctx = ask->private;
248 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
249 unsigned ivsize = crypto_ablkcipher_ivsize(tfm);
250 struct skcipher_sg_list *sgl;
251 struct af_alg_control con = {};
257 if (msg->msg_controllen) {
258 err = af_alg_cmsg_send(msg, &con);
273 if (con.iv && con.iv->ivlen != ivsize)
280 if (!ctx->more && ctx->used)
286 memcpy(ctx->iv, con.iv->iv, ivsize);
290 struct scatterlist *sg;
291 unsigned long len = size;
295 sgl = list_entry(ctx->tsgl.prev,
296 struct skcipher_sg_list, list);
297 sg = sgl->sg + sgl->cur - 1;
298 len = min_t(unsigned long, len,
299 PAGE_SIZE - sg->offset - sg->length);
301 err = memcpy_fromiovec(page_address(sg_page(sg)) +
302 sg->offset + sg->length,
308 ctx->merge = (sg->offset + sg->length) &
317 if (!skcipher_writable(sk)) {
318 err = skcipher_wait_for_wmem(sk, msg->msg_flags);
323 len = min_t(unsigned long, len, skcipher_sndbuf(sk));
325 err = skcipher_alloc_sgl(sk);
329 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
333 plen = min_t(int, len, PAGE_SIZE);
335 sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
337 if (!sg_page(sg + i))
340 err = memcpy_fromiovec(page_address(sg_page(sg + i)),
343 __free_page(sg_page(sg + i));
344 sg_assign_page(sg + i, NULL);
354 } while (len && sgl->cur < MAX_SGL_ENTS);
356 ctx->merge = plen & (PAGE_SIZE - 1);
361 ctx->more = msg->msg_flags & MSG_MORE;
362 if (!ctx->more && !list_empty(&ctx->tsgl))
363 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
366 skcipher_data_wakeup(sk);
369 return copied ?: err;
372 static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
373 int offset, size_t size, int flags)
375 struct sock *sk = sock->sk;
376 struct alg_sock *ask = alg_sk(sk);
377 struct skcipher_ctx *ctx = ask->private;
378 struct skcipher_sg_list *sgl;
381 if (flags & MSG_SENDPAGE_NOTLAST)
385 if (!ctx->more && ctx->used)
391 if (!skcipher_writable(sk)) {
392 err = skcipher_wait_for_wmem(sk, flags);
397 err = skcipher_alloc_sgl(sk);
402 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
405 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
410 ctx->more = flags & MSG_MORE;
411 if (!ctx->more && !list_empty(&ctx->tsgl))
412 sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
415 skcipher_data_wakeup(sk);
421 static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
422 struct msghdr *msg, size_t ignored, int flags)
424 struct sock *sk = sock->sk;
425 struct alg_sock *ask = alg_sk(sk);
426 struct skcipher_ctx *ctx = ask->private;
427 unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm(
429 struct skcipher_sg_list *sgl;
430 struct scatterlist *sg;
431 unsigned long iovlen;
438 for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
440 unsigned long seglen = iov->iov_len;
441 char __user *from = iov->iov_base;
444 sgl = list_first_entry(&ctx->tsgl,
445 struct skcipher_sg_list, list);
453 err = skcipher_wait_for_data(sk, flags);
458 used = min_t(unsigned long, used, seglen);
460 used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
465 if (ctx->more || used < ctx->used)
472 ablkcipher_request_set_crypt(&ctx->req, sg,
476 err = af_alg_wait_for_completion(
478 crypto_ablkcipher_encrypt(&ctx->req) :
479 crypto_ablkcipher_decrypt(&ctx->req),
483 af_alg_free_sg(&ctx->rsgl);
491 skcipher_pull_sgl(sk, used);
498 skcipher_wmem_wakeup(sk);
501 return copied ?: err;
505 static unsigned int skcipher_poll(struct file *file, struct socket *sock,
508 struct sock *sk = sock->sk;
509 struct alg_sock *ask = alg_sk(sk);
510 struct skcipher_ctx *ctx = ask->private;
513 sock_poll_wait(file, sk_sleep(sk), wait);
517 mask |= POLLIN | POLLRDNORM;
519 if (skcipher_writable(sk))
520 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
525 static struct proto_ops algif_skcipher_ops = {
528 .connect = sock_no_connect,
529 .socketpair = sock_no_socketpair,
530 .getname = sock_no_getname,
531 .ioctl = sock_no_ioctl,
532 .listen = sock_no_listen,
533 .shutdown = sock_no_shutdown,
534 .getsockopt = sock_no_getsockopt,
535 .mmap = sock_no_mmap,
536 .bind = sock_no_bind,
537 .accept = sock_no_accept,
538 .setsockopt = sock_no_setsockopt,
540 .release = af_alg_release,
541 .sendmsg = skcipher_sendmsg,
542 .sendpage = skcipher_sendpage,
543 .recvmsg = skcipher_recvmsg,
544 .poll = skcipher_poll,
547 static void *skcipher_bind(const char *name, u32 type, u32 mask)
549 return crypto_alloc_ablkcipher(name, type, mask);
552 static void skcipher_release(void *private)
554 crypto_free_ablkcipher(private);
557 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
559 return crypto_ablkcipher_setkey(private, key, keylen);
562 static void skcipher_sock_destruct(struct sock *sk)
564 struct alg_sock *ask = alg_sk(sk);
565 struct skcipher_ctx *ctx = ask->private;
566 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
568 skcipher_free_sgl(sk);
569 sock_kfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
570 sock_kfree_s(sk, ctx, ctx->len);
571 af_alg_release_parent(sk);
574 static int skcipher_accept_parent(void *private, struct sock *sk)
576 struct skcipher_ctx *ctx;
577 struct alg_sock *ask = alg_sk(sk);
578 unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(private);
580 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
584 ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(private),
587 sock_kfree_s(sk, ctx, len);
591 memset(ctx->iv, 0, crypto_ablkcipher_ivsize(private));
593 INIT_LIST_HEAD(&ctx->tsgl);
599 af_alg_init_completion(&ctx->completion);
603 ablkcipher_request_set_tfm(&ctx->req, private);
604 ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
605 af_alg_complete, &ctx->completion);
607 sk->sk_destruct = skcipher_sock_destruct;
612 static const struct af_alg_type algif_type_skcipher = {
613 .bind = skcipher_bind,
614 .release = skcipher_release,
615 .setkey = skcipher_setkey,
616 .accept = skcipher_accept_parent,
617 .ops = &algif_skcipher_ops,
622 static int __init algif_skcipher_init(void)
624 return af_alg_register_type(&algif_type_skcipher);
627 static void __exit algif_skcipher_exit(void)
629 int err = af_alg_unregister_type(&algif_type_skcipher);
633 module_init(algif_skcipher_init);
634 module_exit(algif_skcipher_exit);
635 MODULE_LICENSE("GPL");