kernel/crypto/zlib.c

   1 /*
   2  * Cryptographic API.
   3  *
   4  * Zlib algorithm
   5  *
   6  * Copyright 2008 Sony Corporation
   7  *
   8  * Based on deflate.c, which is
   9  * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the Free
  13  * Software Foundation; either version 2 of the License, or (at your option)
  14  * any later version.
  15  *
  16  * FIXME: deflate transforms will require up to a total of about 436k of kernel
  17  * memory on i386 (390k for compression, the rest for decompression), as the
  18  * current zlib kernel code uses a worst case pre-allocation system by default.
  19  * This needs to be fixed so that the amount of memory required is properly
  20  * related to the winbits and memlevel parameters.
  21  */
  22
  23 #define pr_fmt(fmt)     "%s: " fmt, __func__
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/zlib.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/mm.h>
  31 #include <linux/net.h>
  32
  33 #include <crypto/internal/compress.h>
  34
  35 #include <net/netlink.h>
  36
  37
  38 struct zlib_ctx {
  39         struct z_stream_s comp_stream;
  40         struct z_stream_s decomp_stream;
  41         int decomp_windowBits;
  42 };
  43
  44
  45 static void zlib_comp_exit(struct zlib_ctx *ctx)
  46 {
  47         struct z_stream_s *stream = &ctx->comp_stream;
  48
  49         if (stream->workspace) {
  50                 zlib_deflateEnd(stream);
  51                 vfree(stream->workspace);
  52                 stream->workspace = NULL;
  53         }
  54 }
  55
  56 static void zlib_decomp_exit(struct zlib_ctx *ctx)
  57 {
  58         struct z_stream_s *stream = &ctx->decomp_stream;
  59
  60         if (stream->workspace) {
  61                 zlib_inflateEnd(stream);
  62                 vfree(stream->workspace);
  63                 stream->workspace = NULL;
  64         }
  65 }
  66
  67 static int zlib_init(struct crypto_tfm *tfm)
  68 {
  69         return 0;
  70 }
  71
  72 static void zlib_exit(struct crypto_tfm *tfm)
  73 {
  74         struct zlib_ctx *ctx = crypto_tfm_ctx(tfm);
  75
  76         zlib_comp_exit(ctx);
  77         zlib_decomp_exit(ctx);
  78 }
  79
  80
  81 static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params,
  82                                unsigned int len)
  83 {
  84         struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
  85         struct z_stream_s *stream = &ctx->comp_stream;
  86         struct nlattr *tb[ZLIB_COMP_MAX + 1];
  87         int window_bits, mem_level;
  88         size_t workspacesize;
  89         int ret;
  90
  91         ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL);
  92         if (ret)
  93                 return ret;
  94
  95         zlib_comp_exit(ctx);
  96
  97         window_bits = tb[ZLIB_COMP_WINDOWBITS]
  98                                         ? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
  99                                         : MAX_WBITS;
 100         mem_level = tb[ZLIB_COMP_MEMLEVEL]
 101                                         ? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
 102                                         : DEF_MEM_LEVEL;
 103
 104         workspacesize = zlib_deflate_workspacesize(window_bits, mem_level);
 105         stream->workspace = vzalloc(workspacesize);
 106         if (!stream->workspace)
 107                 return -ENOMEM;
 108
 109         ret = zlib_deflateInit2(stream,
 110                                 tb[ZLIB_COMP_LEVEL]
 111                                         ? nla_get_u32(tb[ZLIB_COMP_LEVEL])
 112                                         : Z_DEFAULT_COMPRESSION,
 113                                 tb[ZLIB_COMP_METHOD]
 114                                         ? nla_get_u32(tb[ZLIB_COMP_METHOD])
 115                                         : Z_DEFLATED,
 116                                 window_bits,
 117                                 mem_level,
 118                                 tb[ZLIB_COMP_STRATEGY]
 119                                         ? nla_get_u32(tb[ZLIB_COMP_STRATEGY])
 120                                         : Z_DEFAULT_STRATEGY);
 121         if (ret != Z_OK) {
 122                 vfree(stream->workspace);
 123                 stream->workspace = NULL;
 124                 return -EINVAL;
 125         }
 126
 127         return 0;
 128 }
 129
 130 static int zlib_compress_init(struct crypto_pcomp *tfm)
 131 {
 132         int ret;
 133         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 134         struct z_stream_s *stream = &dctx->comp_stream;
 135
 136         ret = zlib_deflateReset(stream);
 137         if (ret != Z_OK)
 138                 return -EINVAL;
 139
 140         return 0;
 141 }
 142
 143 static int zlib_compress_update(struct crypto_pcomp *tfm,
 144                                 struct comp_request *req)
 145 {
 146         int ret;
 147         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 148         struct z_stream_s *stream = &dctx->comp_stream;
 149
 150         pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 151         stream->next_in = req->next_in;
 152         stream->avail_in = req->avail_in;
 153         stream->next_out = req->next_out;
 154         stream->avail_out = req->avail_out;
 155
 156         ret = zlib_deflate(stream, Z_NO_FLUSH);
 157         switch (ret) {
 158         case Z_OK:
 159                 break;
 160
 161         case Z_BUF_ERROR:
 162                 pr_debug("zlib_deflate could not make progress\n");
 163                 return -EAGAIN;
 164
 165         default:
 166                 pr_debug("zlib_deflate failed %d\n", ret);
 167                 return -EINVAL;
 168         }
 169
 170         ret = req->avail_out - stream->avail_out;
 171         pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n",
 172                  stream->avail_in, stream->avail_out,
 173                  req->avail_in - stream->avail_in, ret);
 174         req->next_in = stream->next_in;
 175         req->avail_in = stream->avail_in;
 176         req->next_out = stream->next_out;
 177         req->avail_out = stream->avail_out;
 178         return ret;
 179 }
 180
 181 static int zlib_compress_final(struct crypto_pcomp *tfm,
 182                                struct comp_request *req)
 183 {
 184         int ret;
 185         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 186         struct z_stream_s *stream = &dctx->comp_stream;
 187
 188         pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 189         stream->next_in = req->next_in;
 190         stream->avail_in = req->avail_in;
 191         stream->next_out = req->next_out;
 192         stream->avail_out = req->avail_out;
 193
 194         ret = zlib_deflate(stream, Z_FINISH);
 195         if (ret != Z_STREAM_END) {
 196                 pr_debug("zlib_deflate failed %d\n", ret);
 197                 return -EINVAL;
 198         }
 199
 200         ret = req->avail_out - stream->avail_out;
 201         pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n",
 202                  stream->avail_in, stream->avail_out,
 203                  req->avail_in - stream->avail_in, ret);
 204         req->next_in = stream->next_in;
 205         req->avail_in = stream->avail_in;
 206         req->next_out = stream->next_out;
 207         req->avail_out = stream->avail_out;
 208         return ret;
 209 }
 210
 211
 212 static int zlib_decompress_setup(struct crypto_pcomp *tfm, void *params,
 213                                  unsigned int len)
 214 {
 215         struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 216         struct z_stream_s *stream = &ctx->decomp_stream;
 217         struct nlattr *tb[ZLIB_DECOMP_MAX + 1];
 218         int ret = 0;
 219
 220         ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL);
 221         if (ret)
 222                 return ret;
 223
 224         zlib_decomp_exit(ctx);
 225
 226         ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS]
 227                                  ? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS])
 228                                  : DEF_WBITS;
 229
 230         stream->workspace = vzalloc(zlib_inflate_workspacesize());
 231         if (!stream->workspace)
 232                 return -ENOMEM;
 233
 234         ret = zlib_inflateInit2(stream, ctx->decomp_windowBits);
 235         if (ret != Z_OK) {
 236                 vfree(stream->workspace);
 237                 stream->workspace = NULL;
 238                 return -EINVAL;
 239         }
 240
 241         return 0;
 242 }
 243
 244 static int zlib_decompress_init(struct crypto_pcomp *tfm)
 245 {
 246         int ret;
 247         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 248         struct z_stream_s *stream = &dctx->decomp_stream;
 249
 250         ret = zlib_inflateReset(stream);
 251         if (ret != Z_OK)
 252                 return -EINVAL;
 253
 254         return 0;
 255 }
 256
 257 static int zlib_decompress_update(struct crypto_pcomp *tfm,
 258                                   struct comp_request *req)
 259 {
 260         int ret;
 261         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 262         struct z_stream_s *stream = &dctx->decomp_stream;
 263
 264         pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 265         stream->next_in = req->next_in;
 266         stream->avail_in = req->avail_in;
 267         stream->next_out = req->next_out;
 268         stream->avail_out = req->avail_out;
 269
 270         ret = zlib_inflate(stream, Z_SYNC_FLUSH);
 271         switch (ret) {
 272         case Z_OK:
 273         case Z_STREAM_END:
 274                 break;
 275
 276         case Z_BUF_ERROR:
 277                 pr_debug("zlib_inflate could not make progress\n");
 278                 return -EAGAIN;
 279
 280         default:
 281                 pr_debug("zlib_inflate failed %d\n", ret);
 282                 return -EINVAL;
 283         }
 284
 285         ret = req->avail_out - stream->avail_out;
 286         pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n",
 287                  stream->avail_in, stream->avail_out,
 288                  req->avail_in - stream->avail_in, ret);
 289         req->next_in = stream->next_in;
 290         req->avail_in = stream->avail_in;
 291         req->next_out = stream->next_out;
 292         req->avail_out = stream->avail_out;
 293         return ret;
 294 }
 295
 296 static int zlib_decompress_final(struct crypto_pcomp *tfm,
 297                                  struct comp_request *req)
 298 {
 299         int ret;
 300         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 301         struct z_stream_s *stream = &dctx->decomp_stream;
 302
 303         pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 304         stream->next_in = req->next_in;
 305         stream->avail_in = req->avail_in;
 306         stream->next_out = req->next_out;
 307         stream->avail_out = req->avail_out;
 308
 309         if (dctx->decomp_windowBits < 0) {
 310                 ret = zlib_inflate(stream, Z_SYNC_FLUSH);
 311                 /*
 312                  * Work around a bug in zlib, which sometimes wants to taste an
 313                  * extra byte when being used in the (undocumented) raw deflate
 314                  * mode. (From USAGI).
 315                  */
 316                 if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
 317                         const void *saved_next_in = stream->next_in;
 318                         u8 zerostuff = 0;
 319
 320                         stream->next_in = &zerostuff;
 321                         stream->avail_in = 1;
 322                         ret = zlib_inflate(stream, Z_FINISH);
 323                         stream->next_in = saved_next_in;
 324                         stream->avail_in = 0;
 325                 }
 326         } else
 327                 ret = zlib_inflate(stream, Z_FINISH);
 328         if (ret != Z_STREAM_END) {
 329                 pr_debug("zlib_inflate failed %d\n", ret);
 330                 return -EINVAL;
 331         }
 332
 333         ret = req->avail_out - stream->avail_out;
 334         pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n",
 335                  stream->avail_in, stream->avail_out,
 336                  req->avail_in - stream->avail_in, ret);
 337         req->next_in = stream->next_in;
 338         req->avail_in = stream->avail_in;
 339         req->next_out = stream->next_out;
 340         req->avail_out = stream->avail_out;
 341         return ret;
 342 }
 343
 344
 345 static struct pcomp_alg zlib_alg = {
 346         .compress_setup         = zlib_compress_setup,
 347         .compress_init          = zlib_compress_init,
 348         .compress_update        = zlib_compress_update,
 349         .compress_final         = zlib_compress_final,
 350         .decompress_setup       = zlib_decompress_setup,
 351         .decompress_init        = zlib_decompress_init,
 352         .decompress_update      = zlib_decompress_update,
 353         .decompress_final       = zlib_decompress_final,
 354
 355         .base                   = {
 356                 .cra_name       = "zlib",
 357                 .cra_flags      = CRYPTO_ALG_TYPE_PCOMPRESS,
 358                 .cra_ctxsize    = sizeof(struct zlib_ctx),
 359                 .cra_module     = THIS_MODULE,
 360                 .cra_init       = zlib_init,
 361                 .cra_exit       = zlib_exit,
 362         }
 363 };
 364
 365 static int __init zlib_mod_init(void)
 366 {
 367         return crypto_register_pcomp(&zlib_alg);
 368 }
 369
 370 static void __exit zlib_mod_fini(void)
 371 {
 372         crypto_unregister_pcomp(&zlib_alg);
 373 }
 374
 375 module_init(zlib_mod_init);
 376 module_exit(zlib_mod_fini);
 377
 378 MODULE_LICENSE("GPL");
 379 MODULE_DESCRIPTION("Zlib Compression Algorithm");
 380 MODULE_AUTHOR("Sony Corporation");
 381 MODULE_ALIAS_CRYPTO("zlib");