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 list_add(&node->list, &alg_types);
84 up_write(&alg_types_sem);
88 EXPORT_SYMBOL_GPL(af_alg_register_type);
90 int af_alg_unregister_type(const struct af_alg_type *type)
92 struct alg_type_list *node;
95 down_write(&alg_types_sem);
96 list_for_each_entry(node, &alg_types, list) {
97 if (strcmp(node->type->name, type->name))
100 list_del(&node->list);
105 up_write(&alg_types_sem);
109 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
111 static void alg_do_release(const struct af_alg_type *type, void *private)
116 type->release(private);
117 module_put(type->owner);
120 int af_alg_release(struct socket *sock)
126 EXPORT_SYMBOL_GPL(af_alg_release);
128 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
130 struct sock *sk = sock->sk;
131 struct alg_sock *ask = alg_sk(sk);
132 struct sockaddr_alg *sa = (void *)uaddr;
133 const struct af_alg_type *type;
136 if (sock->state == SS_CONNECTED)
139 if (addr_len != sizeof(*sa))
142 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
143 sa->salg_name[sizeof(sa->salg_name) - 1] = 0;
145 type = alg_get_type(sa->salg_type);
146 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
147 request_module("algif-%s", sa->salg_type);
148 type = alg_get_type(sa->salg_type);
152 return PTR_ERR(type);
154 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
155 if (IS_ERR(private)) {
156 module_put(type->owner);
157 return PTR_ERR(private);
162 swap(ask->type, type);
163 swap(ask->private, private);
167 alg_do_release(type, private);
172 static int alg_setkey(struct sock *sk, char __user *ukey,
175 struct alg_sock *ask = alg_sk(sk);
176 const struct af_alg_type *type = ask->type;
180 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
185 if (copy_from_user(key, ukey, keylen))
188 err = type->setkey(ask->private, key, keylen);
191 sock_kfree_s(sk, key, keylen);
196 static int alg_setsockopt(struct socket *sock, int level, int optname,
197 char __user *optval, unsigned int optlen)
199 struct sock *sk = sock->sk;
200 struct alg_sock *ask = alg_sk(sk);
201 const struct af_alg_type *type;
202 int err = -ENOPROTOOPT;
207 if (level != SOL_ALG || !type)
212 if (sock->state == SS_CONNECTED)
217 err = alg_setkey(sk, optval, optlen);
226 int af_alg_accept(struct sock *sk, struct socket *newsock)
228 struct alg_sock *ask = alg_sk(sk);
229 const struct af_alg_type *type;
240 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto);
245 sock_init_data(newsock, sk2);
246 sock_graft(sk2, newsock);
247 security_sk_clone(sk, sk2);
249 err = type->accept(ask->private, sk2);
253 sk2->sk_family = PF_ALG;
256 alg_sk(sk2)->parent = sk;
257 alg_sk(sk2)->type = type;
259 newsock->ops = type->ops;
260 newsock->state = SS_CONNECTED;
269 EXPORT_SYMBOL_GPL(af_alg_accept);
271 static int alg_accept(struct socket *sock, struct socket *newsock, int flags)
273 return af_alg_accept(sock->sk, newsock);
276 static const struct proto_ops alg_proto_ops = {
278 .owner = THIS_MODULE,
280 .connect = sock_no_connect,
281 .socketpair = sock_no_socketpair,
282 .getname = sock_no_getname,
283 .ioctl = sock_no_ioctl,
284 .listen = sock_no_listen,
285 .shutdown = sock_no_shutdown,
286 .getsockopt = sock_no_getsockopt,
287 .mmap = sock_no_mmap,
288 .sendpage = sock_no_sendpage,
289 .sendmsg = sock_no_sendmsg,
290 .recvmsg = sock_no_recvmsg,
291 .poll = sock_no_poll,
294 .release = af_alg_release,
295 .setsockopt = alg_setsockopt,
296 .accept = alg_accept,
299 static void alg_sock_destruct(struct sock *sk)
301 struct alg_sock *ask = alg_sk(sk);
303 alg_do_release(ask->type, ask->private);
306 static int alg_create(struct net *net, struct socket *sock, int protocol,
312 if (sock->type != SOCK_SEQPACKET)
313 return -ESOCKTNOSUPPORT;
315 return -EPROTONOSUPPORT;
318 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto);
322 sock->ops = &alg_proto_ops;
323 sock_init_data(sock, sk);
325 sk->sk_family = PF_ALG;
326 sk->sk_destruct = alg_sock_destruct;
333 static const struct net_proto_family alg_family = {
335 .create = alg_create,
336 .owner = THIS_MODULE,
339 int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len,
342 unsigned long from = (unsigned long)addr;
343 unsigned long npages;
349 if (!access_ok(write ? VERIFY_READ : VERIFY_WRITE, addr, len))
352 off = from & ~PAGE_MASK;
353 npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
354 if (npages > ALG_MAX_PAGES)
355 npages = ALG_MAX_PAGES;
357 err = get_user_pages_fast(from, npages, write, sgl->pages);
363 if (WARN_ON(npages == 0))
368 sg_init_table(sgl->sg, npages);
370 for (i = 0; i < npages; i++) {
371 int plen = min_t(int, len, PAGE_SIZE - off);
373 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
383 EXPORT_SYMBOL_GPL(af_alg_make_sg);
385 void af_alg_free_sg(struct af_alg_sgl *sgl)
391 put_page(sgl->pages[i]);
392 } while (!sg_is_last(sgl->sg + (i++)));
394 EXPORT_SYMBOL_GPL(af_alg_free_sg);
396 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
398 struct cmsghdr *cmsg;
400 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
401 if (!CMSG_OK(msg, cmsg))
403 if (cmsg->cmsg_level != SOL_ALG)
406 switch(cmsg->cmsg_type) {
408 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
410 con->iv = (void *)CMSG_DATA(cmsg);
411 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
417 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
419 con->op = *(u32 *)CMSG_DATA(cmsg);
429 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
431 int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
436 wait_for_completion(&completion->completion);
437 INIT_COMPLETION(completion->completion);
438 err = completion->err;
444 EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
446 void af_alg_complete(struct crypto_async_request *req, int err)
448 struct af_alg_completion *completion = req->data;
450 if (err == -EINPROGRESS)
453 completion->err = err;
454 complete(&completion->completion);
456 EXPORT_SYMBOL_GPL(af_alg_complete);
458 static int __init af_alg_init(void)
460 int err = proto_register(&alg_proto, 0);
465 err = sock_register(&alg_family);
467 goto out_unregister_proto;
472 out_unregister_proto:
473 proto_unregister(&alg_proto);
477 static void __exit af_alg_exit(void)
479 sock_unregister(PF_ALG);
480 proto_unregister(&alg_proto);
483 module_init(af_alg_init);
484 module_exit(af_alg_exit);
485 MODULE_LICENSE("GPL");
486 MODULE_ALIAS_NETPROTO(AF_ALG);