1 /* 2 * Software async crypto daemon. 3 * 4 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the Free 8 * Software Foundation; either version 2 of the License, or (at your option) 9 * any later version. 10 * 11 */ 12 13 #include <crypto/algapi.h> 14 #include <linux/err.h> 15 #include <linux/init.h> 16 #include <linux/kernel.h> 17 #include <linux/kthread.h> 18 #include <linux/list.h> 19 #include <linux/module.h> 20 #include <linux/mutex.h> 21 #include <linux/scatterlist.h> 22 #include <linux/sched.h> 23 #include <linux/slab.h> 24 #include <linux/spinlock.h> 25 26 #define CRYPTD_MAX_QLEN 100 27 28 struct cryptd_state { 29 spinlock_t lock; 30 struct mutex mutex; 31 struct crypto_queue queue; 32 struct task_struct *task; 33 }; 34 35 struct cryptd_instance_ctx { 36 struct crypto_spawn spawn; 37 struct cryptd_state *state; 38 }; 39 40 struct cryptd_blkcipher_ctx { 41 struct crypto_blkcipher *child; 42 }; 43 44 struct cryptd_blkcipher_request_ctx { 45 crypto_completion_t complete; 46 }; 47 48 49 static inline struct cryptd_state *cryptd_get_state(struct crypto_tfm *tfm) 50 { 51 struct crypto_instance *inst = crypto_tfm_alg_instance(tfm); 52 struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst); 53 return ictx->state; 54 } 55 56 static int cryptd_blkcipher_setkey(struct crypto_ablkcipher *parent, 57 const u8 *key, unsigned int keylen) 58 { 59 struct cryptd_blkcipher_ctx *ctx = crypto_ablkcipher_ctx(parent); 60 struct crypto_blkcipher *child = ctx->child; 61 int err; 62 63 crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); 64 crypto_blkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) & 65 CRYPTO_TFM_REQ_MASK); 66 err = crypto_blkcipher_setkey(child, key, keylen); 67 crypto_ablkcipher_set_flags(parent, crypto_blkcipher_get_flags(child) & 68 CRYPTO_TFM_RES_MASK); 69 return err; 70 } 71 72 static void cryptd_blkcipher_crypt(struct ablkcipher_request *req, 73 struct crypto_blkcipher *child, 74 int err, 75 int (*crypt)(struct blkcipher_desc *desc, 76 struct scatterlist *dst, 77 struct scatterlist *src, 78 unsigned int len)) 79 { 80 struct cryptd_blkcipher_request_ctx *rctx; 81 struct blkcipher_desc desc; 82 83 rctx = ablkcipher_request_ctx(req); 84 85 if (unlikely(err == -EINPROGRESS)) { 86 rctx->complete(&req->base, err); 87 return; 88 } 89 90 desc.tfm = child; 91 desc.info = req->info; 92 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; 93 94 err = crypt(&desc, req->dst, req->src, req->nbytes); 95 96 req->base.complete = rctx->complete; 97 98 local_bh_disable(); 99 req->base.complete(&req->base, err); 100 local_bh_enable(); 101 } 102 103 static void cryptd_blkcipher_encrypt(struct crypto_async_request *req, int err) 104 { 105 struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm); 106 struct crypto_blkcipher *child = ctx->child; 107 108 cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err, 109 crypto_blkcipher_crt(child)->encrypt); 110 } 111 112 static void cryptd_blkcipher_decrypt(struct crypto_async_request *req, int err) 113 { 114 struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm); 115 struct crypto_blkcipher *child = ctx->child; 116 117 cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err, 118 crypto_blkcipher_crt(child)->decrypt); 119 } 120 121 static int cryptd_blkcipher_enqueue(struct ablkcipher_request *req, 122 crypto_completion_t complete) 123 { 124 struct cryptd_blkcipher_request_ctx *rctx = ablkcipher_request_ctx(req); 125 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req); 126 struct cryptd_state *state = 127 cryptd_get_state(crypto_ablkcipher_tfm(tfm)); 128 int err; 129 130 rctx->complete = req->base.complete; 131 req->base.complete = complete; 132 133 spin_lock_bh(&state->lock); 134 err = ablkcipher_enqueue_request(crypto_ablkcipher_alg(tfm), req); 135 spin_unlock_bh(&state->lock); 136 137 wake_up_process(state->task); 138 return err; 139 } 140 141 static int cryptd_blkcipher_encrypt_enqueue(struct ablkcipher_request *req) 142 { 143 return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_encrypt); 144 } 145 146 static int cryptd_blkcipher_decrypt_enqueue(struct ablkcipher_request *req) 147 { 148 return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_decrypt); 149 } 150 151 static int cryptd_blkcipher_init_tfm(struct crypto_tfm *tfm) 152 { 153 struct crypto_instance *inst = crypto_tfm_alg_instance(tfm); 154 struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst); 155 struct crypto_spawn *spawn = &ictx->spawn; 156 struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm); 157 struct crypto_blkcipher *cipher; 158 159 cipher = crypto_spawn_blkcipher(spawn); 160 if (IS_ERR(cipher)) 161 return PTR_ERR(cipher); 162 163 ctx->child = cipher; 164 tfm->crt_ablkcipher.reqsize = 165 sizeof(struct cryptd_blkcipher_request_ctx); 166 return 0; 167 } 168 169 static void cryptd_blkcipher_exit_tfm(struct crypto_tfm *tfm) 170 { 171 struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm); 172 struct cryptd_state *state = cryptd_get_state(tfm); 173 int active; 174 175 mutex_lock(&state->mutex); 176 active = ablkcipher_tfm_in_queue(__crypto_ablkcipher_cast(tfm)); 177 mutex_unlock(&state->mutex); 178 179 BUG_ON(active); 180 181 crypto_free_blkcipher(ctx->child); 182 } 183 184 static struct crypto_instance *cryptd_alloc_instance(struct crypto_alg *alg, 185 struct cryptd_state *state) 186 { 187 struct crypto_instance *inst; 188 struct cryptd_instance_ctx *ctx; 189 int err; 190 191 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 192 if (IS_ERR(inst)) 193 goto out; 194 195 err = -ENAMETOOLONG; 196 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, 197 "cryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) 198 goto out_free_inst; 199 200 ctx = crypto_instance_ctx(inst); 201 err = crypto_init_spawn(&ctx->spawn, alg, inst, 202 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC); 203 if (err) 204 goto out_free_inst; 205 206 ctx->state = state; 207 208 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME); 209 210 inst->alg.cra_priority = alg->cra_priority + 50; 211 inst->alg.cra_blocksize = alg->cra_blocksize; 212 inst->alg.cra_alignmask = alg->cra_alignmask; 213 214 out: 215 return inst; 216 217 out_free_inst: 218 kfree(inst); 219 inst = ERR_PTR(err); 220 goto out; 221 } 222 223 static struct crypto_instance *cryptd_alloc_blkcipher( 224 struct rtattr **tb, struct cryptd_state *state) 225 { 226 struct crypto_instance *inst; 227 struct crypto_alg *alg; 228 229 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER, 230 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC); 231 if (IS_ERR(alg)) 232 return ERR_PTR(PTR_ERR(alg)); 233 234 inst = cryptd_alloc_instance(alg, state); 235 if (IS_ERR(inst)) 236 goto out_put_alg; 237 238 inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_ASYNC; 239 inst->alg.cra_type = &crypto_ablkcipher_type; 240 241 inst->alg.cra_ablkcipher.ivsize = alg->cra_blkcipher.ivsize; 242 inst->alg.cra_ablkcipher.min_keysize = alg->cra_blkcipher.min_keysize; 243 inst->alg.cra_ablkcipher.max_keysize = alg->cra_blkcipher.max_keysize; 244 245 inst->alg.cra_ctxsize = sizeof(struct cryptd_blkcipher_ctx); 246 247 inst->alg.cra_init = cryptd_blkcipher_init_tfm; 248 inst->alg.cra_exit = cryptd_blkcipher_exit_tfm; 249 250 inst->alg.cra_ablkcipher.setkey = cryptd_blkcipher_setkey; 251 inst->alg.cra_ablkcipher.encrypt = cryptd_blkcipher_encrypt_enqueue; 252 inst->alg.cra_ablkcipher.decrypt = cryptd_blkcipher_decrypt_enqueue; 253 254 inst->alg.cra_ablkcipher.queue = &state->queue; 255 256 out_put_alg: 257 crypto_mod_put(alg); 258 return inst; 259 } 260 261 static struct cryptd_state state; 262 263 static struct crypto_instance *cryptd_alloc(struct rtattr **tb) 264 { 265 struct crypto_attr_type *algt; 266 267 algt = crypto_get_attr_type(tb); 268 if (IS_ERR(algt)) 269 return ERR_PTR(PTR_ERR(algt)); 270 271 switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) { 272 case CRYPTO_ALG_TYPE_BLKCIPHER: 273 return cryptd_alloc_blkcipher(tb, &state); 274 } 275 276 return ERR_PTR(-EINVAL); 277 } 278 279 static void cryptd_free(struct crypto_instance *inst) 280 { 281 struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst); 282 283 crypto_drop_spawn(&ctx->spawn); 284 kfree(inst); 285 } 286 287 static struct crypto_template cryptd_tmpl = { 288 .name = "cryptd", 289 .alloc = cryptd_alloc, 290 .free = cryptd_free, 291 .module = THIS_MODULE, 292 }; 293 294 static inline int cryptd_create_thread(struct cryptd_state *state, 295 int (*fn)(void *data), const char *name) 296 { 297 spin_lock_init(&state->lock); 298 mutex_init(&state->mutex); 299 crypto_init_queue(&state->queue, CRYPTD_MAX_QLEN); 300 301 state->task = kthread_run(fn, state, name); 302 if (IS_ERR(state->task)) 303 return PTR_ERR(state->task); 304 305 return 0; 306 } 307 308 static inline void cryptd_stop_thread(struct cryptd_state *state) 309 { 310 BUG_ON(state->queue.qlen); 311 kthread_stop(state->task); 312 } 313 314 static int cryptd_thread(void *data) 315 { 316 struct cryptd_state *state = data; 317 int stop; 318 319 current->flags |= PF_NOFREEZE; 320 321 do { 322 struct crypto_async_request *req, *backlog; 323 324 mutex_lock(&state->mutex); 325 __set_current_state(TASK_INTERRUPTIBLE); 326 327 spin_lock_bh(&state->lock); 328 backlog = crypto_get_backlog(&state->queue); 329 req = crypto_dequeue_request(&state->queue); 330 spin_unlock_bh(&state->lock); 331 332 stop = kthread_should_stop(); 333 334 if (stop || req) { 335 __set_current_state(TASK_RUNNING); 336 if (req) { 337 if (backlog) 338 backlog->complete(backlog, 339 -EINPROGRESS); 340 req->complete(req, 0); 341 } 342 } 343 344 mutex_unlock(&state->mutex); 345 346 schedule(); 347 } while (!stop); 348 349 return 0; 350 } 351 352 static int __init cryptd_init(void) 353 { 354 int err; 355 356 err = cryptd_create_thread(&state, cryptd_thread, "cryptd"); 357 if (err) 358 return err; 359 360 err = crypto_register_template(&cryptd_tmpl); 361 if (err) 362 kthread_stop(state.task); 363 364 return err; 365 } 366 367 static void __exit cryptd_exit(void) 368 { 369 cryptd_stop_thread(&state); 370 crypto_unregister_template(&cryptd_tmpl); 371 } 372 373 module_init(cryptd_init); 374 module_exit(cryptd_exit); 375 376 MODULE_LICENSE("GPL"); 377 MODULE_DESCRIPTION("Software async crypto daemon"); 378