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                         return -ENOMEM;
 130         }
 131         return 0;
 132 }
 133
 134 static void crypto_scomp_sg_free(struct scatterlist *sgl)
 135 {
 136         int i, n;
 137         struct page *page;
 138
 139         if (!sgl)
 140                 return;
 141
 142         n = sg_nents(sgl);
 143         for_each_sg(sgl, sgl, n, i) {
 144                 page = sg_page(sgl);
 145                 if (page)
 146                         __free_page(page);
 147         }
 148
 149         kfree(sgl);
 150 }
 151
 152 static struct scatterlist *crypto_scomp_sg_alloc(size_t size, gfp_t gfp)
 153 {
 154         struct scatterlist *sgl;
 155         struct page *page;
 156         int i, n;
 157
 158         n = ((size - 1) >> PAGE_SHIFT) + 1;
 159
 160         sgl = kmalloc_array(n, sizeof(struct scatterlist), gfp);
 161         if (!sgl)
 162                 return NULL;
 163
 164         sg_init_table(sgl, n);
 165
 166         for (i = 0; i < n; i++) {
 167                 page = alloc_page(gfp);
 168                 if (!page)
 169                         goto err;
 170                 sg_set_page(sgl + i, page, PAGE_SIZE, 0);
 171         }
 172
 173         return sgl;
 174
 175 err:
 176         sg_mark_end(sgl + i);
 177         crypto_scomp_sg_free(sgl);
 178         return NULL;
 179 }
 180
 181 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 182 {
 183         struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
 184         void **tfm_ctx = acomp_tfm_ctx(tfm);
 185         struct crypto_scomp *scomp = *tfm_ctx;
 186         void **ctx = acomp_request_ctx(req);
 187         const int cpu = get_cpu();
 188         u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
 189         u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
 190         int ret;
 191
 192         if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
 193                 ret = -EINVAL;
 194                 goto out;
 195         }
 196
 197         if (req->dst && !req->dlen) {
 198                 ret = -EINVAL;
 199                 goto out;
 200         }
 201
 202         if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
 203                 req->dlen = SCOMP_SCRATCH_SIZE;
 204
 205         scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
 206         if (dir)
 207                 ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
 208                                             scratch_dst, &req->dlen, *ctx);
 209         else
 210                 ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
 211                                               scratch_dst, &req->dlen, *ctx);
 212         if (!ret) {
 213                 if (!req->dst) {
 214                         req->dst = crypto_scomp_sg_alloc(req->dlen,
 215                                    req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 216                                    GFP_KERNEL : GFP_ATOMIC);
 217                         if (!req->dst)
 218                                 goto out;
 219                 }
 220                 scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
 221                                          1);
 222         }
 223 out:
 224         put_cpu();
 225         return ret;
 226 }
 227
 228 static int scomp_acomp_compress(struct acomp_req *req)
 229 {
 230         return scomp_acomp_comp_decomp(req, 1);
 231 }
 232
 233 static int scomp_acomp_decompress(struct acomp_req *req)
 234 {
 235         return scomp_acomp_comp_decomp(req, 0);
 236 }
 237
 238 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
 239 {
 240         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 241
 242         crypto_free_scomp(*ctx);
 243 }
 244
 245 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
 246 {
 247         struct crypto_alg *calg = tfm->__crt_alg;
 248         struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
 249         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 250         struct crypto_scomp *scomp;
 251
 252         if (!crypto_mod_get(calg))
 253                 return -EAGAIN;
 254
 255         scomp = crypto_create_tfm(calg, &crypto_scomp_type);
 256         if (IS_ERR(scomp)) {
 257                 crypto_mod_put(calg);
 258                 return PTR_ERR(scomp);
 259         }
 260
 261         *ctx = scomp;
 262         tfm->exit = crypto_exit_scomp_ops_async;
 263
 264         crt->compress = scomp_acomp_compress;
 265         crt->decompress = scomp_acomp_decompress;
 266         crt->dst_free = crypto_scomp_sg_free;
 267         crt->reqsize = sizeof(void *);
 268
 269         return 0;
 270 }
 271
 272 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
 273 {
 274         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 275         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 276         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 277         struct crypto_scomp *scomp = *tfm_ctx;
 278         void *ctx;
 279
 280         ctx = crypto_scomp_alloc_ctx(scomp);
 281         if (IS_ERR(ctx)) {
 282                 kfree(req);
 283                 return NULL;
 284         }
 285
 286         *req->__ctx = ctx;
 287
 288         return req;
 289 }
 290
 291 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
 292 {
 293         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 294         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 295         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 296         struct crypto_scomp *scomp = *tfm_ctx;
 297         void *ctx = *req->__ctx;
 298
 299         if (ctx)
 300                 crypto_scomp_free_ctx(scomp, ctx);
 301 }
 302
 303 static const struct crypto_type crypto_scomp_type = {
 304         .extsize = crypto_alg_extsize,
 305         .init_tfm = crypto_scomp_init_tfm,
 306 #ifdef CONFIG_PROC_FS
 307         .show = crypto_scomp_show,
 308 #endif
 309         .report = crypto_scomp_report,
 310         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 311         .maskset = CRYPTO_ALG_TYPE_MASK,
 312         .type = CRYPTO_ALG_TYPE_SCOMPRESS,
 313         .tfmsize = offsetof(struct crypto_scomp, base),
 314 };
 315
 316 int crypto_register_scomp(struct scomp_alg *alg)
 317 {
 318         struct crypto_alg *base = &alg->base;
 319         int ret = -ENOMEM;
 320
 321         mutex_lock(&scomp_lock);
 322         if (crypto_scomp_alloc_all_scratches())
 323                 goto error;
 324
 325         base->cra_type = &crypto_scomp_type;
 326         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 327         base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
 328
 329         ret = crypto_register_alg(base);
 330         if (ret)
 331                 goto error;
 332
 333         mutex_unlock(&scomp_lock);
 334         return ret;
 335
 336 error:
 337         crypto_scomp_free_all_scratches();
 338         mutex_unlock(&scomp_lock);
 339         return ret;
 340 }
 341 EXPORT_SYMBOL_GPL(crypto_register_scomp);
 342
 343 int crypto_unregister_scomp(struct scomp_alg *alg)
 344 {
 345         int ret;
 346
 347         mutex_lock(&scomp_lock);
 348         ret = crypto_unregister_alg(&alg->base);
 349         crypto_scomp_free_all_scratches();
 350         mutex_unlock(&scomp_lock);
 351
 352         return ret;
 353 }
 354 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
 355
 356 MODULE_LICENSE("GPL");
 357 MODULE_DESCRIPTION("Synchronous compression type");