--- /dev/null
+/*
+ * algif_skcipher: User-space interface for skcipher algorithms
+ *
+ * This file provides the user-space API for symmetric key ciphers.
+ *
+ * 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 <crypto/scatterwalk.h>
+#include <crypto/skcipher.h>
+#include <crypto/if_alg.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <net/sock.h>
+
+struct skcipher_sg_list {
+ struct list_head list;
+
+ int cur;
+
+ struct scatterlist sg[0];
+};
+
+struct skcipher_ctx {
+ struct list_head tsgl;
+ struct af_alg_sgl rsgl;
+
+ void *iv;
+
+ struct af_alg_completion completion;
+
+ unsigned used;
+
+ unsigned int len;
+ bool more;
+ bool merge;
+ bool enc;
+
+ struct ablkcipher_request req;
+};
+
+#define MAX_SGL_ENTS ((PAGE_SIZE - sizeof(struct skcipher_sg_list)) / \
+ sizeof(struct scatterlist) - 1)
+
+static inline bool skcipher_writable(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+
+ return ctx->used + PAGE_SIZE <= max_t(int, sk->sk_sndbuf, PAGE_SIZE);
+}
+
+static int skcipher_alloc_sgl(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct skcipher_sg_list *sgl;
+ struct scatterlist *sg = NULL;
+
+ sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
+ if (!list_empty(&ctx->tsgl))
+ sg = sgl->sg;
+
+ if (!sg || sgl->cur >= MAX_SGL_ENTS) {
+ sgl = sock_kmalloc(sk, sizeof(*sgl) +
+ sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
+ GFP_KERNEL);
+ if (!sgl)
+ return -ENOMEM;
+
+ sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
+ sgl->cur = 0;
+
+ if (sg)
+ scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
+
+ list_add_tail(&sgl->list, &ctx->tsgl);
+ }
+
+ return 0;
+}
+
+static void skcipher_pull_sgl(struct sock *sk, int used)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct skcipher_sg_list *sgl;
+ struct scatterlist *sg;
+ int i;
+
+ while (!list_empty(&ctx->tsgl)) {
+ sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
+ list);
+ sg = sgl->sg;
+
+ for (i = 0; i < sgl->cur; i++) {
+ int plen = min_t(int, used, sg[i].length);
+
+ if (!sg_page(sg + i))
+ continue;
+
+ sg[i].length -= plen;
+ sg[i].offset += plen;
+
+ used -= plen;
+ ctx->used -= plen;
+
+ if (sg[i].length)
+ return;
+
+ put_page(sg_page(sg + i));
+ sg_assign_page(sg + i, NULL);
+ }
+
+ list_del(&sgl->list);
+ sock_kfree_s(sk, sgl,
+ sizeof(*sgl) + sizeof(sgl->sg[0]) *
+ (MAX_SGL_ENTS + 1));
+ }
+
+ if (!ctx->used)
+ ctx->merge = 0;
+}
+
+static void skcipher_free_sgl(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+
+ skcipher_pull_sgl(sk, ctx->used);
+}
+
+static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
+{
+ long timeout;
+ DEFINE_WAIT(wait);
+ int err = -ERESTARTSYS;
+
+ if (flags & MSG_DONTWAIT)
+ return -EAGAIN;
+
+ set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+ for (;;) {
+ if (signal_pending(current))
+ break;
+ prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) {
+ err = 0;
+ break;
+ }
+ }
+ finish_wait(sk_sleep(sk), &wait);
+
+ return err;
+}
+
+static void skcipher_wmem_wakeup(struct sock *sk)
+{
+ struct socket_wq *wq;
+
+ if (!skcipher_writable(sk))
+ return;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
+ POLLRDNORM |
+ POLLRDBAND);
+ sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+ rcu_read_unlock();
+}
+
+static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ long timeout;
+ DEFINE_WAIT(wait);
+ int err = -ERESTARTSYS;
+
+ if (flags & MSG_DONTWAIT) {
+ return -EAGAIN;
+ }
+
+ set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
+
+ for (;;) {
+ if (signal_pending(current))
+ break;
+ prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ if (sk_wait_event(sk, &timeout, ctx->used)) {
+ err = 0;
+ break;
+ }
+ }
+ finish_wait(sk_sleep(sk), &wait);
+
+ clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
+
+ return err;
+}
+
+static void skcipher_data_wakeup(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct socket_wq *wq;
+
+ if (!ctx->used)
+ return;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
+ POLLRDNORM |
+ POLLRDBAND);
+ sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+ rcu_read_unlock();
+}
+
+static int skcipher_sendmsg(struct kiocb *unused, struct socket *sock,
+ struct msghdr *msg, size_t size)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
+ unsigned ivsize = crypto_ablkcipher_ivsize(tfm);
+ struct skcipher_sg_list *sgl;
+ struct af_alg_control con = {};
+ long copied = 0;
+ bool enc = 0;
+ int limit;
+ int err;
+ int i;
+
+ if (msg->msg_controllen) {
+ err = af_alg_cmsg_send(msg, &con);
+ if (err)
+ return err;
+
+ switch (con.op) {
+ case ALG_OP_ENCRYPT:
+ enc = 1;
+ break;
+ case ALG_OP_DECRYPT:
+ enc = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (con.iv && con.iv->ivlen != ivsize)
+ return -EINVAL;
+ }
+
+ err = -EINVAL;
+
+ lock_sock(sk);
+ if (!ctx->more && ctx->used)
+ goto unlock;
+
+ if (!ctx->used) {
+ ctx->enc = enc;
+ if (con.iv)
+ memcpy(ctx->iv, con.iv->iv, ivsize);
+ }
+
+ limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE);
+ limit -= ctx->used;
+
+ while (size) {
+ struct scatterlist *sg;
+ unsigned long len = size;
+ int plen;
+
+ if (ctx->merge) {
+ sgl = list_entry(ctx->tsgl.prev,
+ struct skcipher_sg_list, list);
+ sg = sgl->sg + sgl->cur - 1;
+ len = min_t(unsigned long, len,
+ PAGE_SIZE - sg->offset - sg->length);
+
+ err = memcpy_fromiovec(page_address(sg_page(sg)) +
+ sg->offset + sg->length,
+ msg->msg_iov, len);
+ if (err)
+ goto unlock;
+
+ sg->length += len;
+ ctx->merge = (sg->offset + sg->length) &
+ (PAGE_SIZE - 1);
+
+ ctx->used += len;
+ copied += len;
+ size -= len;
+ limit -= len;
+ continue;
+ }
+
+ if (limit < PAGE_SIZE) {
+ err = skcipher_wait_for_wmem(sk, msg->msg_flags);
+ if (err)
+ goto unlock;
+
+ limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE);
+ limit -= ctx->used;
+ }
+
+ len = min_t(unsigned long, len, limit);
+
+ err = skcipher_alloc_sgl(sk);
+ if (err)
+ goto unlock;
+
+ sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
+ sg = sgl->sg;
+ do {
+ i = sgl->cur;
+ plen = min_t(int, len, PAGE_SIZE);
+
+ sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
+ err = -ENOMEM;
+ if (!sg_page(sg + i))
+ goto unlock;
+
+ err = memcpy_fromiovec(page_address(sg_page(sg + i)),
+ msg->msg_iov, plen);
+ if (err) {
+ __free_page(sg_page(sg + i));
+ sg_assign_page(sg + i, NULL);
+ goto unlock;
+ }
+
+ sg[i].length = plen;
+ len -= plen;
+ ctx->used += plen;
+ copied += plen;
+ size -= plen;
+ limit -= plen;
+ sgl->cur++;
+ } while (len && sgl->cur < MAX_SGL_ENTS);
+
+ ctx->merge = plen & (PAGE_SIZE - 1);
+ }
+
+ err = 0;
+
+ ctx->more = msg->msg_flags & MSG_MORE;
+ if (!ctx->more && !list_empty(&ctx->tsgl))
+ sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
+
+unlock:
+ skcipher_data_wakeup(sk);
+ release_sock(sk);
+
+ return copied ?: err;
+}
+
+static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
+ int offset, size_t size, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct skcipher_sg_list *sgl;
+ int err = -EINVAL;
+ int limit;
+
+ lock_sock(sk);
+ if (!ctx->more && ctx->used)
+ goto unlock;
+
+ if (!size)
+ goto done;
+
+ limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE);
+ limit -= ctx->used;
+
+ if (limit < PAGE_SIZE) {
+ err = skcipher_wait_for_wmem(sk, flags);
+ if (err)
+ goto unlock;
+
+ limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE);
+ limit -= ctx->used;
+ }
+
+ err = skcipher_alloc_sgl(sk);
+ if (err)
+ goto unlock;
+
+ ctx->merge = 0;
+ sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
+
+ get_page(page);
+ sg_set_page(sgl->sg + sgl->cur, page, size, offset);
+ sgl->cur++;
+ ctx->used += size;
+
+done:
+ ctx->more = flags & MSG_MORE;
+ if (!ctx->more && !list_empty(&ctx->tsgl))
+ sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
+
+unlock:
+ skcipher_data_wakeup(sk);
+ release_sock(sk);
+
+ return err ?: size;
+}
+
+static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
+ struct msghdr *msg, size_t ignored, int flags)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm(
+ &ctx->req));
+ struct skcipher_sg_list *sgl;
+ struct scatterlist *sg;
+ unsigned long iovlen;
+ struct iovec *iov;
+ int err = -EAGAIN;
+ int used;
+ long copied = 0;
+
+ lock_sock(sk);
+ for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
+ iovlen--, iov++) {
+ unsigned long seglen = iov->iov_len;
+ char __user *from = iov->iov_base;
+
+ while (seglen) {
+ sgl = list_first_entry(&ctx->tsgl,
+ struct skcipher_sg_list, list);
+ sg = sgl->sg;
+
+ while (!sg->length)
+ sg++;
+
+ used = ctx->used;
+ if (!used) {
+ err = skcipher_wait_for_data(sk, flags);
+ if (err)
+ goto unlock;
+ }
+
+ used = min_t(unsigned long, used, seglen);
+
+ if (ctx->more || used < ctx->used)
+ used -= used % bs;
+
+ err = -EINVAL;
+ if (!used)
+ goto unlock;
+
+ used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
+ if (used < 0)
+ goto unlock;
+
+ ablkcipher_request_set_crypt(&ctx->req, sg,
+ ctx->rsgl.sg, used,
+ ctx->iv);
+
+ err = af_alg_wait_for_completion(
+ ctx->enc ?
+ crypto_ablkcipher_encrypt(&ctx->req) :
+ crypto_ablkcipher_decrypt(&ctx->req),
+ &ctx->completion);
+
+ af_alg_free_sg(&ctx->rsgl);
+
+ if (err)
+ goto unlock;
+
+ copied += used;
+ from += used;
+ seglen -= used;
+ skcipher_pull_sgl(sk, used);
+ }
+ }
+
+ err = 0;
+
+unlock:
+ skcipher_wmem_wakeup(sk);
+ release_sock(sk);
+
+ return copied ?: err;
+}
+
+
+static unsigned int skcipher_poll(struct file *file, struct socket *sock,
+ poll_table *wait)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ unsigned int mask;
+
+ sock_poll_wait(file, sk_sleep(sk), wait);
+ mask = 0;
+
+ if (ctx->used)
+ mask |= POLLIN | POLLRDNORM;
+
+ if (skcipher_writable(sk))
+ mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
+
+ return mask;
+}
+
+static struct proto_ops algif_skcipher_ops = {
+ .family = PF_ALG,
+
+ .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,
+ .bind = sock_no_bind,
+ .accept = sock_no_accept,
+ .setsockopt = sock_no_setsockopt,
+
+ .release = af_alg_release,
+ .sendmsg = skcipher_sendmsg,
+ .sendpage = skcipher_sendpage,
+ .recvmsg = skcipher_recvmsg,
+ .poll = skcipher_poll,
+};
+
+static void *skcipher_bind(const char *name, u32 type, u32 mask)
+{
+ return crypto_alloc_ablkcipher(name, type, mask);
+}
+
+static void skcipher_release(void *private)
+{
+ crypto_free_ablkcipher(private);
+}
+
+static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
+{
+ return crypto_ablkcipher_setkey(private, key, keylen);
+}
+
+static void skcipher_sock_destruct(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct skcipher_ctx *ctx = ask->private;
+ struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
+
+ skcipher_free_sgl(sk);
+ sock_kfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
+ sock_kfree_s(sk, ctx, ctx->len);
+ af_alg_release_parent(sk);
+}
+
+static int skcipher_accept_parent(void *private, struct sock *sk)
+{
+ struct skcipher_ctx *ctx;
+ struct alg_sock *ask = alg_sk(sk);
+ unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(private);
+
+ ctx = sock_kmalloc(sk, len, GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(private),
+ GFP_KERNEL);
+ if (!ctx->iv) {
+ sock_kfree_s(sk, ctx, len);
+ return -ENOMEM;
+ }
+
+ memset(ctx->iv, 0, crypto_ablkcipher_ivsize(private));
+
+ INIT_LIST_HEAD(&ctx->tsgl);
+ ctx->len = len;
+ ctx->used = 0;
+ ctx->more = 0;
+ ctx->merge = 0;
+ ctx->enc = 0;
+ af_alg_init_completion(&ctx->completion);
+
+ ask->private = ctx;
+
+ ablkcipher_request_set_tfm(&ctx->req, private);
+ ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ af_alg_complete, &ctx->completion);
+
+ sk->sk_destruct = skcipher_sock_destruct;
+
+ return 0;
+}
+
+static const struct af_alg_type algif_type_skcipher = {
+ .bind = skcipher_bind,
+ .release = skcipher_release,
+ .setkey = skcipher_setkey,
+ .accept = skcipher_accept_parent,
+ .ops = &algif_skcipher_ops,
+ .name = "skcipher",
+ .owner = THIS_MODULE
+};
+
+static int __init algif_skcipher_init(void)
+{
+ return af_alg_register_type(&algif_type_skcipher);
+}
+
+static void __exit algif_skcipher_exit(void)
+{
+ int err = af_alg_unregister_type(&algif_type_skcipher);
+ BUG_ON(err);
+}
+
+module_init(algif_skcipher_init);
+module_exit(algif_skcipher_exit);
+MODULE_LICENSE("GPL");
projects / linux-flexiantxendom0-natty.git / blobdiff