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 <asm/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>
25 struct alg_type_list {
26 const struct af_alg_type *type;
27 struct list_head list;
30 static atomic_t alg_memory_allocated;
32 static struct proto alg_proto = {
35 .memory_allocated = &alg_memory_allocated,
36 .obj_size = sizeof(struct alg_sock),
39 static LIST_HEAD(alg_types);
40 static DECLARE_RWSEM(alg_types_sem);
42 static const struct af_alg_type *alg_get_type(const char *name)
44 const struct af_alg_type *type = ERR_PTR(-ENOENT);
45 struct alg_type_list *node;
47 down_read(&alg_types_sem);
48 list_for_each_entry(node, &alg_types, list) {
49 if (strcmp(node->type->name, name))
52 if (try_module_get(node->type->owner))
56 up_read(&alg_types_sem);
61 int af_alg_register_type(const struct af_alg_type *type)
63 struct alg_type_list *node;
66 down_write(&alg_types_sem);
67 list_for_each_entry(node, &alg_types, list) {
68 if (!strcmp(node->type->name, type->name))
72 node = kmalloc(sizeof(*node), GFP_KERNEL);
77 type->ops->owner = THIS_MODULE;
79 list_add(&node->list, &alg_types);
83 up_write(&alg_types_sem);
87 EXPORT_SYMBOL_GPL(af_alg_register_type);
89 int af_alg_unregister_type(const struct af_alg_type *type)
91 struct alg_type_list *node;
94 down_write(&alg_types_sem);
95 list_for_each_entry(node, &alg_types, list) {
96 if (strcmp(node->type->name, type->name))
99 list_del(&node->list);
104 up_write(&alg_types_sem);
108 EXPORT_SYMBOL_GPL(af_alg_unregister_type);
110 static void alg_do_release(const struct af_alg_type *type, void *private)
115 type->release(private);
116 module_put(type->owner);
119 int af_alg_release(struct socket *sock)
125 EXPORT_SYMBOL_GPL(af_alg_release);
127 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
129 struct sock *sk = sock->sk;
130 struct alg_sock *ask = alg_sk(sk);
131 struct sockaddr_alg *sa = (void *)uaddr;
132 const struct af_alg_type *type;
135 if (sock->state == SS_CONNECTED)
138 if (addr_len != sizeof(*sa))
141 sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
142 sa->salg_name[sizeof(sa->salg_name) - 1] = 0;
144 type = alg_get_type(sa->salg_type);
145 if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {
146 request_module("algif-%s", sa->salg_type);
147 type = alg_get_type(sa->salg_type);
151 return PTR_ERR(type);
153 private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
154 if (IS_ERR(private)) {
155 module_put(type->owner);
156 return PTR_ERR(private);
161 swap(ask->type, type);
162 swap(ask->private, private);
166 alg_do_release(type, private);
171 static int alg_setkey(struct sock *sk, char __user *ukey,
174 struct alg_sock *ask = alg_sk(sk);
175 const struct af_alg_type *type = ask->type;
179 key = sock_kmalloc(sk, keylen, GFP_KERNEL);
184 if (copy_from_user(key, ukey, keylen))
187 err = type->setkey(ask->private, key, keylen);
190 sock_kfree_s(sk, key, keylen);
195 static int alg_setsockopt(struct socket *sock, int level, int optname,
196 char __user *optval, unsigned int optlen)
198 struct sock *sk = sock->sk;
199 struct alg_sock *ask = alg_sk(sk);
200 const struct af_alg_type *type;
201 int err = -ENOPROTOOPT;
206 if (level != SOL_ALG || !type)
211 if (sock->state == SS_CONNECTED)
216 err = alg_setkey(sk, optval, optlen);
225 int af_alg_accept(struct sock *sk, struct socket *newsock)
227 struct alg_sock *ask = alg_sk(sk);
228 const struct af_alg_type *type;
239 sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto);
244 sock_init_data(newsock, sk2);
246 err = type->accept(ask->private, sk2);
252 sk2->sk_family = PF_ALG;
255 alg_sk(sk2)->parent = sk;
256 alg_sk(sk2)->type = type;
258 newsock->ops = type->ops;
259 newsock->state = SS_CONNECTED;
268 EXPORT_SYMBOL_GPL(af_alg_accept);
270 static int alg_accept(struct socket *sock, struct socket *newsock, int flags)
272 return af_alg_accept(sock->sk, newsock);
275 static const struct proto_ops alg_proto_ops = {
277 .owner = THIS_MODULE,
279 .connect = sock_no_connect,
280 .socketpair = sock_no_socketpair,
281 .getname = sock_no_getname,
282 .ioctl = sock_no_ioctl,
283 .listen = sock_no_listen,
284 .shutdown = sock_no_shutdown,
285 .getsockopt = sock_no_getsockopt,
286 .mmap = sock_no_mmap,
287 .sendpage = sock_no_sendpage,
288 .sendmsg = sock_no_sendmsg,
289 .recvmsg = sock_no_recvmsg,
290 .poll = sock_no_poll,
293 .release = af_alg_release,
294 .setsockopt = alg_setsockopt,
295 .accept = alg_accept,
298 static void alg_sock_destruct(struct sock *sk)
300 struct alg_sock *ask = alg_sk(sk);
302 alg_do_release(ask->type, ask->private);
305 static int alg_create(struct net *net, struct socket *sock, int protocol,
311 if (sock->type != SOCK_SEQPACKET)
312 return -ESOCKTNOSUPPORT;
314 return -EPROTONOSUPPORT;
317 sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto);
321 sock->ops = &alg_proto_ops;
322 sock_init_data(sock, sk);
324 sk->sk_family = PF_ALG;
325 sk->sk_destruct = alg_sock_destruct;
332 static const struct net_proto_family alg_family = {
334 .create = alg_create,
335 .owner = THIS_MODULE,
338 int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len,
341 unsigned long from = (unsigned long)addr;
342 unsigned long npages;
348 if (!access_ok(write ? VERIFY_READ : VERIFY_WRITE, addr, len))
351 off = from & ~PAGE_MASK;
352 npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
353 if (npages > ALG_MAX_PAGES)
354 npages = ALG_MAX_PAGES;
356 err = get_user_pages_fast(from, npages, write, sgl->pages);
362 if (WARN_ON(npages == 0))
367 sg_init_table(sgl->sg, npages);
369 for (i = 0; i < npages; i++) {
370 int plen = min_t(int, len, PAGE_SIZE - off);
372 sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);
382 EXPORT_SYMBOL_GPL(af_alg_make_sg);
384 void af_alg_free_sg(struct af_alg_sgl *sgl)
390 put_page(sgl->pages[i]);
391 } while (!sg_is_last(sgl->sg + (i++)));
393 EXPORT_SYMBOL_GPL(af_alg_free_sg);
395 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
397 struct cmsghdr *cmsg;
399 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
400 if (!CMSG_OK(msg, cmsg))
402 if (cmsg->cmsg_level != SOL_ALG)
405 switch(cmsg->cmsg_type) {
407 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv)))
409 con->iv = (void *)CMSG_DATA(cmsg);
410 if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen +
416 if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32)))
418 con->op = *(u32 *)CMSG_DATA(cmsg);
428 EXPORT_SYMBOL_GPL(af_alg_cmsg_send);
430 int af_alg_wait_for_completion(int err, struct af_alg_completion *completion)
435 wait_for_completion(&completion->completion);
436 INIT_COMPLETION(completion->completion);
437 err = completion->err;
443 EXPORT_SYMBOL_GPL(af_alg_wait_for_completion);
445 void af_alg_complete(struct crypto_async_request *req, int err)
447 struct af_alg_completion *completion = req->data;
449 completion->err = err;
450 complete(&completion->completion);
452 EXPORT_SYMBOL_GPL(af_alg_complete);
454 static int __init af_alg_init(void)
456 int err = proto_register(&alg_proto, 0);
461 err = sock_register(&alg_family);
463 goto out_unregister_proto;
468 out_unregister_proto:
469 proto_unregister(&alg_proto);
473 static void __exit af_alg_exit(void)
475 sock_unregister(PF_ALG);
476 proto_unregister(&alg_proto);
479 module_init(af_alg_init);
480 module_exit(af_alg_exit);
481 MODULE_LICENSE("GPL");
482 MODULE_ALIAS_NETPROTO(AF_ALG);