crypto/scompress.c

   1 /*
   2  * Synchronous Compression operations
   3  *
   4  * Copyright 2015 LG Electronics Inc.
   5  * Copyright (c) 2016, Intel Corporation
   6  * Author: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  */
  14 #include <linux/errno.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/slab.h>
  19 #include <linux/string.h>
  20 #include <linux/crypto.h>
  21 #include <linux/compiler.h>
  22 #include <linux/vmalloc.h>
  23 #include <crypto/algapi.h>
  24 #include <linux/cryptouser.h>
  25 #include <net/netlink.h>
  26 #include <linux/scatterlist.h>
  27 #include <crypto/scatterwalk.h>
  28 #include <crypto/internal/acompress.h>
  29 #include <crypto/internal/scompress.h>
  30 #include "internal.h"
  31
  32 static const struct crypto_type crypto_scomp_type;
  33 static void * __percpu *scomp_src_scratches;
  34 static void * __percpu *scomp_dst_scratches;
  35 static int scomp_scratch_users;
  36 static DEFINE_MUTEX(scomp_lock);
  37
  38 #ifdef CONFIG_NET
  39 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  40 {
  41         struct crypto_report_comp rscomp;
  42
  43         strncpy(rscomp.type, "scomp", sizeof(rscomp.type));
  44
  45         if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
  46                     sizeof(struct crypto_report_comp), &rscomp))
  47                 goto nla_put_failure;
  48         return 0;
  49
  50 nla_put_failure:
  51         return -EMSGSIZE;
  52 }
  53 #else
  54 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  55 {
  56         return -ENOSYS;
  57 }
  58 #endif
  59
  60 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  61         __maybe_unused;
  62
  63 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  64 {
  65         seq_puts(m, "type         : scomp\n");
  66 }
  67
  68 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
  69 {
  70         return 0;
  71 }
  72
  73 static void crypto_scomp_free_scratches(void * __percpu *scratches)
  74 {
  75         int i;
  76
  77         if (!scratches)
  78                 return;
  79
  80         for_each_possible_cpu(i)
  81                 vfree(*per_cpu_ptr(scratches, i));
  82
  83         free_percpu(scratches);
  84 }
  85
  86 static void * __percpu *crypto_scomp_alloc_scratches(void)
  87 {
  88         void * __percpu *scratches;
  89         int i;
  90
  91         scratches = alloc_percpu(void *);
  92         if (!scratches)
  93                 return NULL;
  94
  95         for_each_possible_cpu(i) {
  96                 void *scratch;
  97
  98                 scratch = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
  99                 if (!scratch)
 100                         goto error;
 101                 *per_cpu_ptr(scratches, i) = scratch;
 102         }
 103
 104         return scratches;
 105
 106 error:
 107         crypto_scomp_free_scratches(scratches);
 108         return NULL;
 109 }
 110
 111 static void crypto_scomp_free_all_scratches(void)
 112 {
 113         if (!--scomp_scratch_users) {
 114                 crypto_scomp_free_scratches(scomp_src_scratches);
 115                 crypto_scomp_free_scratches(scomp_dst_scratches);
 116                 scomp_src_scratches = NULL;
 117                 scomp_dst_scratches = NULL;
 118         }
 119 }
 120
 121 static int crypto_scomp_alloc_all_scratches(void)
 122 {
 123         if (!scomp_scratch_users++) {
 124                 scomp_src_scratches = crypto_scomp_alloc_scratches();
 125                 if (!scomp_src_scratches)
 126                         return -ENOMEM;
 127                 scomp_dst_scratches = crypto_scomp_alloc_scratches();
 128                 if (!scomp_dst_scratches) {
 129                         crypto_scomp_free_scratches(scomp_src_scratches);
 130                         scomp_src_scratches = NULL;
 131                         return -ENOMEM;
 132                 }
 133         }
 134         return 0;
 135 }
 136
 137 static void crypto_scomp_sg_free(struct scatterlist *sgl)
 138 {
 139         int i, n;
 140         struct page *page;
 141
 142         if (!sgl)
 143                 return;
 144
 145         n = sg_nents(sgl);
 146         for_each_sg(sgl, sgl, n, i) {
 147                 page = sg_page(sgl);
 148                 if (page)
 149                         __free_page(page);
 150         }
 151
 152         kfree(sgl);
 153 }
 154
 155 static struct scatterlist *crypto_scomp_sg_alloc(size_t size, gfp_t gfp)
 156 {
 157         struct scatterlist *sgl;
 158         struct page *page;
 159         int i, n;
 160
 161         n = ((size - 1) >> PAGE_SHIFT) + 1;
 162
 163         sgl = kmalloc_array(n, sizeof(struct scatterlist), gfp);
 164         if (!sgl)
 165                 return NULL;
 166
 167         sg_init_table(sgl, n);
 168
 169         for (i = 0; i < n; i++) {
 170                 page = alloc_page(gfp);
 171                 if (!page)
 172                         goto err;
 173                 sg_set_page(sgl + i, page, PAGE_SIZE, 0);
 174         }
 175
 176         return sgl;
 177
 178 err:
 179         sg_mark_end(sgl + i);
 180         crypto_scomp_sg_free(sgl);
 181         return NULL;
 182 }
 183
 184 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 185 {
 186         struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
 187         void **tfm_ctx = acomp_tfm_ctx(tfm);
 188         struct crypto_scomp *scomp = *tfm_ctx;
 189         void **ctx = acomp_request_ctx(req);
 190         const int cpu = get_cpu();
 191         u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
 192         u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
 193         int ret;
 194
 195         if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
 196                 ret = -EINVAL;
 197                 goto out;
 198         }
 199
 200         if (req->dst && !req->dlen) {
 201                 ret = -EINVAL;
 202                 goto out;
 203         }
 204
 205         if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
 206                 req->dlen = SCOMP_SCRATCH_SIZE;
 207
 208         scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
 209         if (dir)
 210                 ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
 211                                             scratch_dst, &req->dlen, *ctx);
 212         else
 213                 ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
 214                                               scratch_dst, &req->dlen, *ctx);
 215         if (!ret) {
 216                 if (!req->dst) {
 217                         req->dst = crypto_scomp_sg_alloc(req->dlen, GFP_ATOMIC);
 218                         if (!req->dst)
 219                                 goto out;
 220                 }
 221                 scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
 222                                          1);
 223         }
 224 out:
 225         put_cpu();
 226         return ret;
 227 }
 228
 229 static int scomp_acomp_compress(struct acomp_req *req)
 230 {
 231         return scomp_acomp_comp_decomp(req, 1);
 232 }
 233
 234 static int scomp_acomp_decompress(struct acomp_req *req)
 235 {
 236         return scomp_acomp_comp_decomp(req, 0);
 237 }
 238
 239 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
 240 {
 241         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 242
 243         crypto_free_scomp(*ctx);
 244 }
 245
 246 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
 247 {
 248         struct crypto_alg *calg = tfm->__crt_alg;
 249         struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
 250         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 251         struct crypto_scomp *scomp;
 252
 253         if (!crypto_mod_get(calg))
 254                 return -EAGAIN;
 255
 256         scomp = crypto_create_tfm(calg, &crypto_scomp_type);
 257         if (IS_ERR(scomp)) {
 258                 crypto_mod_put(calg);
 259                 return PTR_ERR(scomp);
 260         }
 261
 262         *ctx = scomp;
 263         tfm->exit = crypto_exit_scomp_ops_async;
 264
 265         crt->compress = scomp_acomp_compress;
 266         crt->decompress = scomp_acomp_decompress;
 267         crt->dst_free = crypto_scomp_sg_free;
 268         crt->reqsize = sizeof(void *);
 269
 270         return 0;
 271 }
 272
 273 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
 274 {
 275         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 276         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 277         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 278         struct crypto_scomp *scomp = *tfm_ctx;
 279         void *ctx;
 280
 281         ctx = crypto_scomp_alloc_ctx(scomp);
 282         if (IS_ERR(ctx)) {
 283                 kfree(req);
 284                 return NULL;
 285         }
 286
 287         *req->__ctx = ctx;
 288
 289         return req;
 290 }
 291
 292 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
 293 {
 294         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 295         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 296         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 297         struct crypto_scomp *scomp = *tfm_ctx;
 298         void *ctx = *req->__ctx;
 299
 300         if (ctx)
 301                 crypto_scomp_free_ctx(scomp, ctx);
 302 }
 303
 304 static const struct crypto_type crypto_scomp_type = {
 305         .extsize = crypto_alg_extsize,
 306         .init_tfm = crypto_scomp_init_tfm,
 307 #ifdef CONFIG_PROC_FS
 308         .show = crypto_scomp_show,
 309 #endif
 310         .report = crypto_scomp_report,
 311         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 312         .maskset = CRYPTO_ALG_TYPE_MASK,
 313         .type = CRYPTO_ALG_TYPE_SCOMPRESS,
 314         .tfmsize = offsetof(struct crypto_scomp, base),
 315 };
 316
 317 int crypto_register_scomp(struct scomp_alg *alg)
 318 {
 319         struct crypto_alg *base = &alg->base;
 320         int ret = -ENOMEM;
 321
 322         mutex_lock(&scomp_lock);
 323         if (crypto_scomp_alloc_all_scratches())
 324                 goto error;
 325
 326         base->cra_type = &crypto_scomp_type;
 327         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 328         base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
 329
 330         ret = crypto_register_alg(base);
 331         if (ret)
 332                 goto error;
 333
 334         mutex_unlock(&scomp_lock);
 335         return ret;
 336
 337 error:
 338         crypto_scomp_free_all_scratches();
 339         mutex_unlock(&scomp_lock);
 340         return ret;
 341 }
 342 EXPORT_SYMBOL_GPL(crypto_register_scomp);
 343
 344 int crypto_unregister_scomp(struct scomp_alg *alg)
 345 {
 346         int ret;
 347
 348         mutex_lock(&scomp_lock);
 349         ret = crypto_unregister_alg(&alg->base);
 350         crypto_scomp_free_all_scratches();
 351         mutex_unlock(&scomp_lock);
 352
 353         return ret;
 354 }
 355 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
 356
 357 int crypto_register_scomps(struct scomp_alg *algs, int count)
 358 {
 359         int i, ret;
 360
 361         for (i = 0; i < count; i++) {
 362                 ret = crypto_register_scomp(&algs[i]);
 363                 if (ret)
 364                         goto err;
 365         }
 366
 367         return 0;
 368
 369 err:
 370         for (--i; i >= 0; --i)
 371                 crypto_unregister_scomp(&algs[i]);
 372
 373         return ret;
 374 }
 375 EXPORT_SYMBOL_GPL(crypto_register_scomps);
 376
 377 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
 378 {
 379         int i;
 380
 381         for (i = count - 1; i >= 0; --i)
 382                 crypto_unregister_scomp(&algs[i]);
 383 }
 384 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
 385
 386 MODULE_LICENSE("GPL");
 387 MODULE_DESCRIPTION("Synchronous compression type");