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linux-next/crypto/cryptd.c
Herbert Xu 124b53d020 [CRYPTO] cryptd: Add software async crypto daemon
This patch adds the cryptd module which is a template that takes a
synchronous software crypto algorithm and converts it to an asynchronous
one by executing it in a kernel thread.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-05-02 14:38:32 +10:00

376 lines
9.2 KiB
C

/*
* Software async crypto daemon.
*
* Copyright (c) 2006 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/algapi.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#define CRYPTD_MAX_QLEN 100
struct cryptd_state {
spinlock_t lock;
struct mutex mutex;
struct crypto_queue queue;
struct task_struct *task;
};
struct cryptd_instance_ctx {
struct crypto_spawn spawn;
struct cryptd_state *state;
};
struct cryptd_blkcipher_ctx {
struct crypto_blkcipher *child;
};
struct cryptd_blkcipher_request_ctx {
crypto_completion_t complete;
};
static inline struct cryptd_state *cryptd_get_state(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
return ictx->state;
}
static int cryptd_blkcipher_setkey(struct crypto_ablkcipher *parent,
const u8 *key, unsigned int keylen)
{
struct cryptd_blkcipher_ctx *ctx = crypto_ablkcipher_ctx(parent);
struct crypto_blkcipher *child = ctx->child;
int err;
crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_blkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_blkcipher_setkey(child, key, keylen);
crypto_ablkcipher_set_flags(parent, crypto_blkcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
static void cryptd_blkcipher_crypt(struct ablkcipher_request *req,
struct crypto_blkcipher *child,
int err,
int (*crypt)(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src,
unsigned int len))
{
struct cryptd_blkcipher_request_ctx *rctx;
struct blkcipher_desc desc;
rctx = ablkcipher_request_ctx(req);
if (unlikely(err == -EINPROGRESS)) {
rctx->complete(&req->base, err);
return;
}
desc.tfm = child;
desc.info = req->info;
desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
err = crypt(&desc, req->dst, req->src, req->nbytes);
req->base.complete = rctx->complete;
local_bh_disable();
req->base.complete(&req->base, err);
local_bh_enable();
}
static void cryptd_blkcipher_encrypt(struct crypto_async_request *req, int err)
{
struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
struct crypto_blkcipher *child = ctx->child;
cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
crypto_blkcipher_crt(child)->encrypt);
}
static void cryptd_blkcipher_decrypt(struct crypto_async_request *req, int err)
{
struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
struct crypto_blkcipher *child = ctx->child;
cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
crypto_blkcipher_crt(child)->decrypt);
}
static int cryptd_blkcipher_enqueue(struct ablkcipher_request *req,
crypto_completion_t complete)
{
struct cryptd_blkcipher_request_ctx *rctx = ablkcipher_request_ctx(req);
struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
struct cryptd_state *state =
cryptd_get_state(crypto_ablkcipher_tfm(tfm));
int err;
rctx->complete = req->base.complete;
req->base.complete = complete;
spin_lock_bh(&state->lock);
err = ablkcipher_enqueue_request(crypto_ablkcipher_alg(tfm), req);
spin_unlock_bh(&state->lock);
wake_up_process(state->task);
return err;
}
static int cryptd_blkcipher_encrypt_enqueue(struct ablkcipher_request *req)
{
return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_encrypt);
}
static int cryptd_blkcipher_decrypt_enqueue(struct ablkcipher_request *req)
{
return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_decrypt);
}
static int cryptd_blkcipher_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
struct crypto_spawn *spawn = &ictx->spawn;
struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_blkcipher *cipher;
cipher = crypto_spawn_blkcipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
ctx->child = cipher;
tfm->crt_ablkcipher.reqsize =
sizeof(struct cryptd_blkcipher_request_ctx);
return 0;
}
static void cryptd_blkcipher_exit_tfm(struct crypto_tfm *tfm)
{
struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
struct cryptd_state *state = cryptd_get_state(tfm);
int active;
mutex_lock(&state->mutex);
active = ablkcipher_tfm_in_queue(__crypto_ablkcipher_cast(tfm));
mutex_unlock(&state->mutex);
BUG_ON(active);
crypto_free_blkcipher(ctx->child);
}
static struct crypto_instance *cryptd_alloc_instance(struct crypto_alg *alg,
struct cryptd_state *state)
{
struct crypto_instance *inst;
struct cryptd_instance_ctx *ctx;
int err;
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
if (IS_ERR(inst))
goto out;
err = -ENAMETOOLONG;
if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"cryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto out_free_inst;
ctx = crypto_instance_ctx(inst);
err = crypto_init_spawn(&ctx->spawn, alg, inst,
CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
if (err)
goto out_free_inst;
ctx->state = state;
memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
inst->alg.cra_priority = alg->cra_priority + 50;
inst->alg.cra_blocksize = alg->cra_blocksize;
inst->alg.cra_alignmask = alg->cra_alignmask;
out:
return inst;
out_free_inst:
kfree(inst);
inst = ERR_PTR(err);
goto out;
}
static struct crypto_instance *cryptd_alloc_blkcipher(
struct rtattr **tb, struct cryptd_state *state)
{
struct crypto_instance *inst;
struct crypto_alg *alg;
alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
if (IS_ERR(alg))
return ERR_PTR(PTR_ERR(alg));
inst = cryptd_alloc_instance(alg, state);
if (IS_ERR(inst))
goto out_put_alg;
inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_ASYNC;
inst->alg.cra_type = &crypto_ablkcipher_type;
inst->alg.cra_ablkcipher.ivsize = alg->cra_blkcipher.ivsize;
inst->alg.cra_ablkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
inst->alg.cra_ablkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
inst->alg.cra_ctxsize = sizeof(struct cryptd_blkcipher_ctx);
inst->alg.cra_init = cryptd_blkcipher_init_tfm;
inst->alg.cra_exit = cryptd_blkcipher_exit_tfm;
inst->alg.cra_ablkcipher.setkey = cryptd_blkcipher_setkey;
inst->alg.cra_ablkcipher.encrypt = cryptd_blkcipher_encrypt_enqueue;
inst->alg.cra_ablkcipher.decrypt = cryptd_blkcipher_decrypt_enqueue;
inst->alg.cra_ablkcipher.queue = &state->queue;
out_put_alg:
crypto_mod_put(alg);
return inst;
}
static struct cryptd_state state;
static struct crypto_instance *cryptd_alloc(struct rtattr **tb)
{
struct crypto_attr_type *algt;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return ERR_PTR(PTR_ERR(algt));
switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
case CRYPTO_ALG_TYPE_BLKCIPHER:
return cryptd_alloc_blkcipher(tb, &state);
}
return ERR_PTR(-EINVAL);
}
static void cryptd_free(struct crypto_instance *inst)
{
struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst);
crypto_drop_spawn(&ctx->spawn);
kfree(inst);
}
static struct crypto_template cryptd_tmpl = {
.name = "cryptd",
.alloc = cryptd_alloc,
.free = cryptd_free,
.module = THIS_MODULE,
};
static inline int cryptd_create_thread(struct cryptd_state *state,
int (*fn)(void *data), const char *name)
{
spin_lock_init(&state->lock);
mutex_init(&state->mutex);
crypto_init_queue(&state->queue, CRYPTD_MAX_QLEN);
state->task = kthread_create(fn, state, name);
if (IS_ERR(state->task))
return PTR_ERR(state->task);
return 0;
}
static inline void cryptd_stop_thread(struct cryptd_state *state)
{
BUG_ON(state->queue.qlen);
kthread_stop(state->task);
}
static int cryptd_thread(void *data)
{
struct cryptd_state *state = data;
int stop;
do {
struct crypto_async_request *req, *backlog;
mutex_lock(&state->mutex);
__set_current_state(TASK_INTERRUPTIBLE);
spin_lock_bh(&state->lock);
backlog = crypto_get_backlog(&state->queue);
req = crypto_dequeue_request(&state->queue);
spin_unlock_bh(&state->lock);
stop = kthread_should_stop();
if (stop || req) {
__set_current_state(TASK_RUNNING);
if (req) {
if (backlog)
backlog->complete(backlog,
-EINPROGRESS);
req->complete(req, 0);
}
}
mutex_unlock(&state->mutex);
schedule();
} while (!stop);
return 0;
}
static int __init cryptd_init(void)
{
int err;
err = cryptd_create_thread(&state, cryptd_thread, "cryptd");
if (err)
return err;
err = crypto_register_template(&cryptd_tmpl);
if (err)
kthread_stop(state.task);
return err;
}
static void __exit cryptd_exit(void)
{
cryptd_stop_thread(&state);
crypto_unregister_template(&cryptd_tmpl);
}
module_init(cryptd_init);
module_exit(cryptd_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Software async crypto daemon");