2 * af_alg: User-space algorithm interface
4 * This file provides the user-space API for algorithms.
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 <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/security.h>
26 struct alg_type_list {
27 const struct af_alg_type *type;
28 struct list_head list;
31 static atomic_long_t alg_memory_allocated;
33 static struct proto alg_proto = {
36 .memory_allocated = &alg_memory_allocated,
37 .obj_size = sizeof(struct alg_sock),
40 static LIST_HEAD(alg_types);
41 static DECLARE_RWSEM(alg_types_sem);
43 static const struct af_alg_type *alg_get_type(const char *name)
45 const struct af_alg_type *type = ERR_PTR(-ENOENT);
46 struct alg_type_list *node;
48 down_read(&alg_types_sem);
49 list_for_each_entry(node, &alg_types, list) {
50 if (strcmp(node->type->name, name))
53 if (try_module_get(node->type->owner))
57 up_read(&alg_types_sem);
62 int af_alg_register_type(const struct af_alg_type *type)
64 struct alg_type_list *node;
67 down_write(&alg_types_sem);
68 list_for_each_entry(node, &alg_types, list) {
69 if (!strcmp(node->type->name, type->name))
73 node = kmalloc(sizeof(*node), GFP_KERNEL);
78 type->ops->owner = THIS_MODULE;
80 type->ops_nokey->owner = THIS_MODULE;
82 list_add(&node->list, &alg_types);
86 up_write(&alg_types_sem);
90 EXPORT_SYMBOL_GPL(af_alg_register_type);
92 int af_alg_unregister_type(const struct af_alg_type *type)
94 struct alg_type_list *node;
97 down_write(&alg_types_sem);
98 list_for_each_entry(node, &alg_types, list) {
99 if (strcmp(node->type->name, type->name))
102 list_del(&node->list);
107 up_write(&alg_types_sem);
111 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
113 static void alg_do_release(const struct af_alg_type *type, void *private)
118 type->release(private);
119 module_put(type->owner);
122 int af_alg_release(struct socket *sock)
128 EXPORT_SYMBOL_GPL(af_alg_release);
130 void af_alg_release_parent(struct sock *sk)
132 struct alg_sock *ask = alg_sk(sk);
137 if (ask->nokey_refcnt && !ask->refcnt) {
145 last = !--ask->refcnt;
151 EXPORT_SYMBOL_GPL(af_alg_release_parent);
153 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
155 const u32 forbidden = CRYPTO_ALG_INTERNAL;
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;
163 if (sock->state == SS_CONNECTED)
166 if (addr_len != sizeof(*sa))
169 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
170 sa->salg_name[sizeof(sa->salg_name) - 1] = 0;
172 type = alg_get_type(sa->salg_type);
173 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
174 request_module("algif-%s", sa->salg_type);
175 type = alg_get_type(sa->salg_type);
179 return PTR_ERR(type);
181 private = type->bind(sa->salg_name,
182 sa->salg_feat & ~forbidden,
183 sa->salg_mask & ~forbidden);
184 if (IS_ERR(private)) {
185 module_put(type->owner);
186 return PTR_ERR(private);
194 swap(ask->type, type);
195 swap(ask->private, private);
202 alg_do_release(type, private);
207 static int alg_setkey(struct sock *sk, char __user *ukey,
210 struct alg_sock *ask = alg_sk(sk);
211 const struct af_alg_type *type = ask->type;
215 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
220 if (copy_from_user(key, ukey, keylen))
223 err = type->setkey(ask->private, key, keylen);
226 sock_kzfree_s(sk, key, keylen);
231 static int alg_setsockopt(struct socket *sock, int level, int optname,
232 char __user *optval, unsigned int optlen)
234 struct sock *sk = sock->sk;
235 struct alg_sock *ask = alg_sk(sk);
236 const struct af_alg_type *type;
246 if (level != SOL_ALG || !type)
251 if (sock->state == SS_CONNECTED)
256 err = alg_setkey(sk, optval, optlen);
258 case ALG_SET_AEAD_AUTHSIZE:
259 if (sock->state == SS_CONNECTED)
261 if (!type->setauthsize)
263 err = type->setauthsize(ask->private, optlen);
272 int af_alg_accept(struct sock *sk, struct socket *newsock)
274 struct alg_sock *ask = alg_sk(sk);
275 const struct af_alg_type *type;
287 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto, 0);
292 sock_init_data(newsock, sk2);
293 sock_graft(sk2, newsock);
294 security_sk_clone(sk, sk2);
296 err = type->accept(ask->private, sk2);
298 nokey = err == -ENOKEY;
299 if (nokey && type->accept_nokey)
300 err = type->accept_nokey(ask->private, sk2);
305 sk2->sk_family = PF_ALG;
307 if (nokey || !ask->refcnt++)
309 alg_sk(sk2)->parent = sk;
310 alg_sk(sk2)->type = type;
311 alg_sk(sk2)->nokey_refcnt = nokey;
313 newsock->ops = type->ops;
314 newsock->state = SS_CONNECTED;
317 newsock->ops = type->ops_nokey;
326 EXPORT_SYMBOL_GPL(af_alg_accept);
328 static int alg_accept(struct socket *sock, struct socket *newsock, int flags)
330 return af_alg_accept(sock->sk, newsock);
333 static const struct proto_ops alg_proto_ops = {
335 .owner = THIS_MODULE,
337 .connect = sock_no_connect,
338 .socketpair = sock_no_socketpair,
339 .getname = sock_no_getname,
340 .ioctl = sock_no_ioctl,
341 .listen = sock_no_listen,
342 .shutdown = sock_no_shutdown,
343 .getsockopt = sock_no_getsockopt,
344 .mmap = sock_no_mmap,
345 .sendpage = sock_no_sendpage,
346 .sendmsg = sock_no_sendmsg,
347 .recvmsg = sock_no_recvmsg,
348 .poll = sock_no_poll,
351 .release = af_alg_release,
352 .setsockopt = alg_setsockopt,
353 .accept = alg_accept,
356 static void alg_sock_destruct(struct sock *sk)
358 struct alg_sock *ask = alg_sk(sk);
360 alg_do_release(ask->type, ask->private);
363 static int alg_create(struct net *net, struct socket *sock, int protocol,
369 if (sock->type != SOCK_SEQPACKET)
370 return -ESOCKTNOSUPPORT;
372 return -EPROTONOSUPPORT;
375 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto, kern);
379 sock->ops = &alg_proto_ops;
380 sock_init_data(sock, sk);
382 sk->sk_family = PF_ALG;
383 sk->sk_destruct = alg_sock_destruct;
390 static const struct net_proto_family alg_family = {
392 .create = alg_create,
393 .owner = THIS_MODULE,
396 int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
402 n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
406 npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
407 if (WARN_ON(npages == 0))
409 /* Add one extra for linking */
410 sg_init_table(sgl->sg, npages + 1);
412 for (i = 0, len = n; i < npages; i++) {
413 int plen = min_t(int, len, PAGE_SIZE - off);
415 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
420 sg_mark_end(sgl->sg + npages - 1);
421 sgl->npages = npages;
425 EXPORT_SYMBOL_GPL(af_alg_make_sg);
427 void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
429 sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
430 sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
432 EXPORT_SYMBOL_GPL(af_alg_link_sg);
434 void af_alg_free_sg(struct af_alg_sgl *sgl)
438 for (i = 0; i < sgl->npages; i++)
439 put_page(sgl->pages[i]);
441 EXPORT_SYMBOL_GPL(af_alg_free_sg);
443 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
445 struct cmsghdr *cmsg;
447 for_each_cmsghdr(cmsg, msg) {
448 if (!CMSG_OK(msg, cmsg))
450 if (cmsg->cmsg_level != SOL_ALG)
453 switch (cmsg->cmsg_type) {
455 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
457 con->iv = (void *)CMSG_DATA(cmsg);
458 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
464 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
466 con->op = *(u32 *)CMSG_DATA(cmsg);
469 case ALG_SET_AEAD_ASSOCLEN:
470 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
472 con->aead_assoclen = *(u32 *)CMSG_DATA(cmsg);
482 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
484 int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
489 wait_for_completion(&completion->completion);
490 reinit_completion(&completion->completion);
491 err = completion->err;
497 EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
499 void af_alg_complete(struct crypto_async_request *req, int err)
501 struct af_alg_completion *completion = req->data;
503 if (err == -EINPROGRESS)
506 completion->err = err;
507 complete(&completion->completion);
509 EXPORT_SYMBOL_GPL(af_alg_complete);
511 static int __init af_alg_init(void)
513 int err = proto_register(&alg_proto, 0);
518 err = sock_register(&alg_family);
520 goto out_unregister_proto;
525 out_unregister_proto:
526 proto_unregister(&alg_proto);
530 static void __exit af_alg_exit(void)
532 sock_unregister(PF_ALG);
533 proto_unregister(&alg_proto);
536 module_init(af_alg_init);
537 module_exit(af_alg_exit);
538 MODULE_LICENSE("GPL");
539 MODULE_ALIAS_NETPROTO(AF_ALG);