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);
133 unsigned int nokey = ask->nokey_refcnt;
134 bool last = nokey && !ask->refcnt;
140 ask->nokey_refcnt -= nokey;
142 last = !--ask->refcnt;
148 EXPORT_SYMBOL_GPL(af_alg_release_parent);
150 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
152 const u32 allowed = 0;
153 struct sock *sk = sock->sk;
154 struct alg_sock *ask = alg_sk(sk);
155 struct sockaddr_alg *sa = (void *)uaddr;
156 const struct af_alg_type *type;
160 /* If caller uses non-allowed flag, return error. */
161 if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
164 if (sock->state == SS_CONNECTED)
167 if (addr_len != sizeof(*sa))
170 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
171 sa->salg_name[sizeof(sa->salg_name) - 1] = 0;
173 type = alg_get_type(sa->salg_type);
174 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
175 request_module("algif-%s", sa->salg_type);
176 type = alg_get_type(sa->salg_type);
180 return PTR_ERR(type);
182 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
183 if (IS_ERR(private)) {
184 module_put(type->owner);
185 return PTR_ERR(private);
190 if (ask->refcnt | ask->nokey_refcnt)
193 swap(ask->type, type);
194 swap(ask->private, private);
201 alg_do_release(type, private);
206 static int alg_setkey(struct sock *sk, char __user *ukey,
209 struct alg_sock *ask = alg_sk(sk);
210 const struct af_alg_type *type = ask->type;
214 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
219 if (copy_from_user(key, ukey, keylen))
222 err = type->setkey(ask->private, key, keylen);
225 sock_kfree_s(sk, key, keylen);
230 static int alg_setsockopt(struct socket *sock, int level, int optname,
231 char __user *optval, unsigned int optlen)
233 struct sock *sk = sock->sk;
234 struct alg_sock *ask = alg_sk(sk);
235 const struct af_alg_type *type;
245 if (level != SOL_ALG || !type)
250 if (sock->state == SS_CONNECTED)
255 err = alg_setkey(sk, optval, optlen);
264 int af_alg_accept(struct sock *sk, struct socket *newsock)
266 struct alg_sock *ask = alg_sk(sk);
267 const struct af_alg_type *type;
279 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto);
284 sock_init_data(newsock, sk2);
285 sock_graft(sk2, newsock);
286 security_sk_clone(sk, sk2);
288 err = type->accept(ask->private, sk2);
290 nokey = err == -ENOKEY;
291 if (nokey && type->accept_nokey)
292 err = type->accept_nokey(ask->private, sk2);
297 sk2->sk_family = PF_ALG;
299 if (nokey || !ask->refcnt++)
301 ask->nokey_refcnt += nokey;
302 alg_sk(sk2)->parent = sk;
303 alg_sk(sk2)->type = type;
304 alg_sk(sk2)->nokey_refcnt = nokey;
306 newsock->ops = type->ops;
307 newsock->state = SS_CONNECTED;
310 newsock->ops = type->ops_nokey;
319 EXPORT_SYMBOL_GPL(af_alg_accept);
321 static int alg_accept(struct socket *sock, struct socket *newsock, int flags)
323 return af_alg_accept(sock->sk, newsock);
326 static const struct proto_ops alg_proto_ops = {
328 .owner = THIS_MODULE,
330 .connect = sock_no_connect,
331 .socketpair = sock_no_socketpair,
332 .getname = sock_no_getname,
333 .ioctl = sock_no_ioctl,
334 .listen = sock_no_listen,
335 .shutdown = sock_no_shutdown,
336 .getsockopt = sock_no_getsockopt,
337 .mmap = sock_no_mmap,
338 .sendpage = sock_no_sendpage,
339 .sendmsg = sock_no_sendmsg,
340 .recvmsg = sock_no_recvmsg,
341 .poll = sock_no_poll,
344 .release = af_alg_release,
345 .setsockopt = alg_setsockopt,
346 .accept = alg_accept,
349 static void alg_sock_destruct(struct sock *sk)
351 struct alg_sock *ask = alg_sk(sk);
353 alg_do_release(ask->type, ask->private);
356 static int alg_create(struct net *net, struct socket *sock, int protocol,
362 if (sock->type != SOCK_SEQPACKET)
363 return -ESOCKTNOSUPPORT;
365 return -EPROTONOSUPPORT;
368 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto);
372 sock->ops = &alg_proto_ops;
373 sock_init_data(sock, sk);
375 sk->sk_family = PF_ALG;
376 sk->sk_destruct = alg_sock_destruct;
383 static const struct net_proto_family alg_family = {
385 .create = alg_create,
386 .owner = THIS_MODULE,
389 int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len,
392 unsigned long from = (unsigned long)addr;
393 unsigned long npages;
399 if (!access_ok(write ? VERIFY_READ : VERIFY_WRITE, addr, len))
402 off = from & ~PAGE_MASK;
403 npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
404 if (npages > ALG_MAX_PAGES)
405 npages = ALG_MAX_PAGES;
407 err = get_user_pages_fast(from, npages, write, sgl->pages);
413 if (WARN_ON(npages == 0))
418 sg_init_table(sgl->sg, npages);
420 for (i = 0; i < npages; i++) {
421 int plen = min_t(int, len, PAGE_SIZE - off);
423 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
433 EXPORT_SYMBOL_GPL(af_alg_make_sg);
435 void af_alg_free_sg(struct af_alg_sgl *sgl)
441 put_page(sgl->pages[i]);
442 } while (!sg_is_last(sgl->sg + (i++)));
444 EXPORT_SYMBOL_GPL(af_alg_free_sg);
446 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
448 struct cmsghdr *cmsg;
450 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
451 if (!CMSG_OK(msg, cmsg))
453 if (cmsg->cmsg_level != SOL_ALG)
456 switch(cmsg->cmsg_type) {
458 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
460 con->iv = (void *)CMSG_DATA(cmsg);
461 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
467 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
469 con->op = *(u32 *)CMSG_DATA(cmsg);
479 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
481 int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
486 wait_for_completion(&completion->completion);
487 INIT_COMPLETION(completion->completion);
488 err = completion->err;
494 EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
496 void af_alg_complete(struct crypto_async_request *req, int err)
498 struct af_alg_completion *completion = req->data;
500 if (err == -EINPROGRESS)
503 completion->err = err;
504 complete(&completion->completion);
506 EXPORT_SYMBOL_GPL(af_alg_complete);
508 static int __init af_alg_init(void)
510 int err = proto_register(&alg_proto, 0);
515 err = sock_register(&alg_family);
517 goto out_unregister_proto;
522 out_unregister_proto:
523 proto_unregister(&alg_proto);
527 static void __exit af_alg_exit(void)
529 sock_unregister(PF_ALG);
530 proto_unregister(&alg_proto);
533 module_init(af_alg_init);
534 module_exit(af_alg_exit);
535 MODULE_LICENSE("GPL");
536 MODULE_ALIAS_NETPROTO(AF_ALG);