diff options
Diffstat (limited to 'crypto/af_alg.c')
-rw-r--r-- | crypto/af_alg.c | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c new file mode 100644 index 00000000..940d70cb --- /dev/null +++ b/crypto/af_alg.c @@ -0,0 +1,483 @@ +/* + * af_alg: User-space algorithm interface + * + * This file provides the user-space API for algorithms. + * + * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ + +#include <asm/atomic.h> +#include <crypto/if_alg.h> +#include <linux/crypto.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/net.h> +#include <linux/rwsem.h> + +struct alg_type_list { + const struct af_alg_type *type; + struct list_head list; +}; + +static atomic_long_t alg_memory_allocated; + +static struct proto alg_proto = { + .name = "ALG", + .owner = THIS_MODULE, + .memory_allocated = &alg_memory_allocated, + .obj_size = sizeof(struct alg_sock), +}; + +static LIST_HEAD(alg_types); +static DECLARE_RWSEM(alg_types_sem); + +static const struct af_alg_type *alg_get_type(const char *name) +{ + const struct af_alg_type *type = ERR_PTR(-ENOENT); + struct alg_type_list *node; + + down_read(&alg_types_sem); + list_for_each_entry(node, &alg_types, list) { + if (strcmp(node->type->name, name)) + continue; + + if (try_module_get(node->type->owner)) + type = node->type; + break; + } + up_read(&alg_types_sem); + + return type; +} + +int af_alg_register_type(const struct af_alg_type *type) +{ + struct alg_type_list *node; + int err = -EEXIST; + + down_write(&alg_types_sem); + list_for_each_entry(node, &alg_types, list) { + if (!strcmp(node->type->name, type->name)) + goto unlock; + } + + node = kmalloc(sizeof(*node), GFP_KERNEL); + err = -ENOMEM; + if (!node) + goto unlock; + + type->ops->owner = THIS_MODULE; + node->type = type; + list_add(&node->list, &alg_types); + err = 0; + +unlock: + up_write(&alg_types_sem); + + return err; +} +EXPORT_SYMBOL_GPL(af_alg_register_type); + +int af_alg_unregister_type(const struct af_alg_type *type) +{ + struct alg_type_list *node; + int err = -ENOENT; + + down_write(&alg_types_sem); + list_for_each_entry(node, &alg_types, list) { + if (strcmp(node->type->name, type->name)) + continue; + + list_del(&node->list); + kfree(node); + err = 0; + break; + } + up_write(&alg_types_sem); + + return err; +} +EXPORT_SYMBOL_GPL(af_alg_unregister_type); + +static void alg_do_release(const struct af_alg_type *type, void *private) +{ + if (!type) + return; + + type->release(private); + module_put(type->owner); +} + +int af_alg_release(struct socket *sock) +{ + if (sock->sk) + sock_put(sock->sk); + return 0; +} +EXPORT_SYMBOL_GPL(af_alg_release); + +static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct sockaddr_alg *sa = (void *)uaddr; + const struct af_alg_type *type; + void *private; + + if (sock->state == SS_CONNECTED) + return -EINVAL; + + if (addr_len != sizeof(*sa)) + return -EINVAL; + + sa->salg_type[sizeof(sa->salg_type) - 1] = 0; + sa->salg_name[sizeof(sa->salg_name) - 1] = 0; + + type = alg_get_type(sa->salg_type); + if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) { + request_module("algif-%s", sa->salg_type); + type = alg_get_type(sa->salg_type); + } + + if (IS_ERR(type)) + return PTR_ERR(type); + + private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask); + if (IS_ERR(private)) { + module_put(type->owner); + return PTR_ERR(private); + } + + lock_sock(sk); + + swap(ask->type, type); + swap(ask->private, private); + + release_sock(sk); + + alg_do_release(type, private); + + return 0; +} + +static int alg_setkey(struct sock *sk, char __user *ukey, + unsigned int keylen) +{ + struct alg_sock *ask = alg_sk(sk); + const struct af_alg_type *type = ask->type; + u8 *key; + int err; + + key = sock_kmalloc(sk, keylen, GFP_KERNEL); + if (!key) + return -ENOMEM; + + err = -EFAULT; + if (copy_from_user(key, ukey, keylen)) + goto out; + + err = type->setkey(ask->private, key, keylen); + +out: + sock_kfree_s(sk, key, keylen); + + return err; +} + +static int alg_setsockopt(struct socket *sock, int level, int optname, + char __user *optval, unsigned int optlen) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + const struct af_alg_type *type; + int err = -ENOPROTOOPT; + + lock_sock(sk); + type = ask->type; + + if (level != SOL_ALG || !type) + goto unlock; + + switch (optname) { + case ALG_SET_KEY: + if (sock->state == SS_CONNECTED) + goto unlock; + if (!type->setkey) + goto unlock; + + err = alg_setkey(sk, optval, optlen); + } + +unlock: + release_sock(sk); + + return err; +} + +int af_alg_accept(struct sock *sk, struct socket *newsock) +{ + struct alg_sock *ask = alg_sk(sk); + const struct af_alg_type *type; + struct sock *sk2; + int err; + + lock_sock(sk); + type = ask->type; + + err = -EINVAL; + if (!type) + goto unlock; + + sk2 = sk_alloc(sock_net(sk), PF_ALG, GFP_KERNEL, &alg_proto); + err = -ENOMEM; + if (!sk2) + goto unlock; + + sock_init_data(newsock, sk2); + sock_graft(sk2, newsock); + + err = type->accept(ask->private, sk2); + if (err) { + sk_free(sk2); + goto unlock; + } + + sk2->sk_family = PF_ALG; + + sock_hold(sk); + alg_sk(sk2)->parent = sk; + alg_sk(sk2)->type = type; + + newsock->ops = type->ops; + newsock->state = SS_CONNECTED; + + err = 0; + +unlock: + release_sock(sk); + + return err; +} +EXPORT_SYMBOL_GPL(af_alg_accept); + +static int alg_accept(struct socket *sock, struct socket *newsock, int flags) +{ + return af_alg_accept(sock->sk, newsock); +} + +static const struct proto_ops alg_proto_ops = { + .family = PF_ALG, + .owner = THIS_MODULE, + + .connect = sock_no_connect, + .socketpair = sock_no_socketpair, + .getname = sock_no_getname, + .ioctl = sock_no_ioctl, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .getsockopt = sock_no_getsockopt, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, + .sendmsg = sock_no_sendmsg, + .recvmsg = sock_no_recvmsg, + .poll = sock_no_poll, + + .bind = alg_bind, + .release = af_alg_release, + .setsockopt = alg_setsockopt, + .accept = alg_accept, +}; + +static void alg_sock_destruct(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + + alg_do_release(ask->type, ask->private); +} + +static int alg_create(struct net *net, struct socket *sock, int protocol, + int kern) +{ + struct sock *sk; + int err; + + if (sock->type != SOCK_SEQPACKET) + return -ESOCKTNOSUPPORT; + if (protocol != 0) + return -EPROTONOSUPPORT; + + err = -ENOMEM; + sk = sk_alloc(net, PF_ALG, GFP_KERNEL, &alg_proto); + if (!sk) + goto out; + + sock->ops = &alg_proto_ops; + sock_init_data(sock, sk); + + sk->sk_family = PF_ALG; + sk->sk_destruct = alg_sock_destruct; + + return 0; +out: + return err; +} + +static const struct net_proto_family alg_family = { + .family = PF_ALG, + .create = alg_create, + .owner = THIS_MODULE, +}; + +int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len, + int write) +{ + unsigned long from = (unsigned long)addr; + unsigned long npages; + unsigned off; + int err; + int i; + + err = -EFAULT; + if (!access_ok(write ? VERIFY_READ : VERIFY_WRITE, addr, len)) + goto out; + + off = from & ~PAGE_MASK; + npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (npages > ALG_MAX_PAGES) + npages = ALG_MAX_PAGES; + + err = get_user_pages_fast(from, npages, write, sgl->pages); + if (err < 0) + goto out; + + npages = err; + err = -EINVAL; + if (WARN_ON(npages == 0)) + goto out; + + err = 0; + + sg_init_table(sgl->sg, npages); + + for (i = 0; i < npages; i++) { + int plen = min_t(int, len, PAGE_SIZE - off); + + sg_set_page(sgl->sg + i, sgl->pages[i], plen, off); + + off = 0; + len -= plen; + err += plen; + } + +out: + return err; +} +EXPORT_SYMBOL_GPL(af_alg_make_sg); + +void af_alg_free_sg(struct af_alg_sgl *sgl) +{ + int i; + + i = 0; + do { + put_page(sgl->pages[i]); + } while (!sg_is_last(sgl->sg + (i++))); +} +EXPORT_SYMBOL_GPL(af_alg_free_sg); + +int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con) +{ + struct cmsghdr *cmsg; + + for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { + if (!CMSG_OK(msg, cmsg)) + return -EINVAL; + if (cmsg->cmsg_level != SOL_ALG) + continue; + + switch(cmsg->cmsg_type) { + case ALG_SET_IV: + if (cmsg->cmsg_len < CMSG_LEN(sizeof(*con->iv))) + return -EINVAL; + con->iv = (void *)CMSG_DATA(cmsg); + if (cmsg->cmsg_len < CMSG_LEN(con->iv->ivlen + + sizeof(*con->iv))) + return -EINVAL; + break; + + case ALG_SET_OP: + if (cmsg->cmsg_len < CMSG_LEN(sizeof(u32))) + return -EINVAL; + con->op = *(u32 *)CMSG_DATA(cmsg); + break; + + default: + return -EINVAL; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(af_alg_cmsg_send); + +int af_alg_wait_for_completion(int err, struct af_alg_completion *completion) +{ + switch (err) { + case -EINPROGRESS: + case -EBUSY: + wait_for_completion(&completion->completion); + INIT_COMPLETION(completion->completion); + err = completion->err; + break; + }; + + return err; +} +EXPORT_SYMBOL_GPL(af_alg_wait_for_completion); + +void af_alg_complete(struct crypto_async_request *req, int err) +{ + struct af_alg_completion *completion = req->data; + + completion->err = err; + complete(&completion->completion); +} +EXPORT_SYMBOL_GPL(af_alg_complete); + +static int __init af_alg_init(void) +{ + int err = proto_register(&alg_proto, 0); + + if (err) + goto out; + + err = sock_register(&alg_family); + if (err != 0) + goto out_unregister_proto; + +out: + return err; + +out_unregister_proto: + proto_unregister(&alg_proto); + goto out; +} + +static void __exit af_alg_exit(void) +{ + sock_unregister(PF_ALG); + proto_unregister(&alg_proto); +} + +module_init(af_alg_init); +module_exit(af_alg_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NETPROTO(AF_ALG); |