/* * 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(&state->queue, 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(&state->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; 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_run(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; current->flags |= PF_NOFREEZE; 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");