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(&state->queue, 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(&state->queue, 177 __crypto_ablkcipher_cast(tfm)); 178 mutex_unlock(&state->mutex); 179 180 BUG_ON(active); 181 182 crypto_free_blkcipher(ctx->child); 183 } 184 185 static struct crypto_instance *cryptd_alloc_instance(struct crypto_alg *alg, 186 struct cryptd_state *state) 187 { 188 struct crypto_instance *inst; 189 struct cryptd_instance_ctx *ctx; 190 int err; 191 192 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 193 if (!inst) { 194 inst = ERR_PTR(-ENOMEM); 195 goto out; 196 } 197 198 err = -ENAMETOOLONG; 199 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, 200 "cryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) 201 goto out_free_inst; 202 203 ctx = crypto_instance_ctx(inst); 204 err = crypto_init_spawn(&ctx->spawn, alg, inst, 205 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC); 206 if (err) 207 goto out_free_inst; 208 209 ctx->state = state; 210 211 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME); 212 213 inst->alg.cra_priority = alg->cra_priority + 50; 214 inst->alg.cra_blocksize = alg->cra_blocksize; 215 inst->alg.cra_alignmask = alg->cra_alignmask; 216 217 out: 218 return inst; 219 220 out_free_inst: 221 kfree(inst); 222 inst = ERR_PTR(err); 223 goto out; 224 } 225 226 static struct crypto_instance *cryptd_alloc_blkcipher( 227 struct rtattr **tb, struct cryptd_state *state) 228 { 229 struct crypto_instance *inst; 230 struct crypto_alg *alg; 231 232 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER, 233 CRYPTO_ALG_TYPE_MASK); 234 if (IS_ERR(alg)) 235 return ERR_CAST(alg); 236 237 inst = cryptd_alloc_instance(alg, state); 238 if (IS_ERR(inst)) 239 goto out_put_alg; 240 241 inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC; 242 inst->alg.cra_type = &crypto_ablkcipher_type; 243 244 inst->alg.cra_ablkcipher.ivsize = alg->cra_blkcipher.ivsize; 245 inst->alg.cra_ablkcipher.min_keysize = alg->cra_blkcipher.min_keysize; 246 inst->alg.cra_ablkcipher.max_keysize = alg->cra_blkcipher.max_keysize; 247 248 inst->alg.cra_ablkcipher.geniv = alg->cra_blkcipher.geniv; 249 250 inst->alg.cra_ctxsize = sizeof(struct cryptd_blkcipher_ctx); 251 252 inst->alg.cra_init = cryptd_blkcipher_init_tfm; 253 inst->alg.cra_exit = cryptd_blkcipher_exit_tfm; 254 255 inst->alg.cra_ablkcipher.setkey = cryptd_blkcipher_setkey; 256 inst->alg.cra_ablkcipher.encrypt = cryptd_blkcipher_encrypt_enqueue; 257 inst->alg.cra_ablkcipher.decrypt = cryptd_blkcipher_decrypt_enqueue; 258 259 out_put_alg: 260 crypto_mod_put(alg); 261 return inst; 262 } 263 264 static struct cryptd_state state; 265 266 static struct crypto_instance *cryptd_alloc(struct rtattr **tb) 267 { 268 struct crypto_attr_type *algt; 269 270 algt = crypto_get_attr_type(tb); 271 if (IS_ERR(algt)) 272 return ERR_CAST(algt); 273 274 switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) { 275 case CRYPTO_ALG_TYPE_BLKCIPHER: 276 return cryptd_alloc_blkcipher(tb, &state); 277 } 278 279 return ERR_PTR(-EINVAL); 280 } 281 282 static void cryptd_free(struct crypto_instance *inst) 283 { 284 struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst); 285 286 crypto_drop_spawn(&ctx->spawn); 287 kfree(inst); 288 } 289 290 static struct crypto_template cryptd_tmpl = { 291 .name = "cryptd", 292 .alloc = cryptd_alloc, 293 .free = cryptd_free, 294 .module = THIS_MODULE, 295 }; 296 297 static inline int cryptd_create_thread(struct cryptd_state *state, 298 int (*fn)(void *data), const char *name) 299 { 300 spin_lock_init(&state->lock); 301 mutex_init(&state->mutex); 302 crypto_init_queue(&state->queue, CRYPTD_MAX_QLEN); 303 304 state->task = kthread_run(fn, state, name); 305 if (IS_ERR(state->task)) 306 return PTR_ERR(state->task); 307 308 return 0; 309 } 310 311 static inline void cryptd_stop_thread(struct cryptd_state *state) 312 { 313 BUG_ON(state->queue.qlen); 314 kthread_stop(state->task); 315 } 316 317 static int cryptd_thread(void *data) 318 { 319 struct cryptd_state *state = data; 320 int stop; 321 322 current->flags |= PF_NOFREEZE; 323 324 do { 325 struct crypto_async_request *req, *backlog; 326 327 mutex_lock(&state->mutex); 328 __set_current_state(TASK_INTERRUPTIBLE); 329 330 spin_lock_bh(&state->lock); 331 backlog = crypto_get_backlog(&state->queue); 332 req = crypto_dequeue_request(&state->queue); 333 spin_unlock_bh(&state->lock); 334 335 stop = kthread_should_stop(); 336 337 if (stop || req) { 338 __set_current_state(TASK_RUNNING); 339 if (req) { 340 if (backlog) 341 backlog->complete(backlog, 342 -EINPROGRESS); 343 req->complete(req, 0); 344 } 345 } 346 347 mutex_unlock(&state->mutex); 348 349 schedule(); 350 } while (!stop); 351 352 return 0; 353 } 354 355 static int __init cryptd_init(void) 356 { 357 int err; 358 359 err = cryptd_create_thread(&state, cryptd_thread, "cryptd"); 360 if (err) 361 return err; 362 363 err = crypto_register_template(&cryptd_tmpl); 364 if (err) 365 kthread_stop(state.task); 366 367 return err; 368 } 369 370 static void __exit cryptd_exit(void) 371 { 372 cryptd_stop_thread(&state); 373 crypto_unregister_template(&cryptd_tmpl); 374 } 375 376 module_init(cryptd_init); 377 module_exit(cryptd_exit); 378 379 MODULE_LICENSE("GPL"); 380 MODULE_DESCRIPTION("Software async crypto daemon"); 381