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 <[email protected]>
  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 #include <linux/slab.h>
  33
  34 #include <crypto/internal/compress.h>
  35
  36 #include <net/netlink.h>
  37
  38
  39 struct zlib_ctx {
  40         struct z_stream_s comp_stream;
  41         struct z_stream_s decomp_stream;
  42         int decomp_windowBits;
  43 };
  44
  45
  46 static void zlib_comp_exit(struct zlib_ctx *ctx)
  47 {
  48         struct z_stream_s *stream = &ctx->comp_stream;
  49
  50         if (stream->workspace) {
  51                 zlib_deflateEnd(stream);
  52                 vfree(stream->workspace);
  53                 stream->workspace = NULL;
  54         }
  55 }
  56
  57 static void zlib_decomp_exit(struct zlib_ctx *ctx)
  58 {
  59         struct z_stream_s *stream = &ctx->decomp_stream;
  60
  61         if (stream->workspace) {
  62                 zlib_inflateEnd(stream);
  63                 kfree(stream->workspace);
  64                 stream->workspace = NULL;
  65         }
  66 }
  67
  68 static int zlib_init(struct crypto_tfm *tfm)
  69 {
  70         return 0;
  71 }
  72
  73 static void zlib_exit(struct crypto_tfm *tfm)
  74 {
  75         struct zlib_ctx *ctx = crypto_tfm_ctx(tfm);
  76
  77         zlib_comp_exit(ctx);
  78         zlib_decomp_exit(ctx);
  79 }
  80
  81
  82 static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params,
  83                                unsigned int len)
  84 {
  85         struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
  86         struct z_stream_s *stream = &ctx->comp_stream;
  87         struct nlattr *tb[ZLIB_COMP_MAX + 1];
  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         workspacesize = zlib_deflate_workspacesize();
  98         stream->workspace = vzalloc(workspacesize);
  99         if (!stream->workspace)
 100                 return -ENOMEM;
 101
 102         ret = zlib_deflateInit2(stream,
 103                                 tb[ZLIB_COMP_LEVEL]
 104                                         ? nla_get_u32(tb[ZLIB_COMP_LEVEL])
 105                                         : Z_DEFAULT_COMPRESSION,
 106                                 tb[ZLIB_COMP_METHOD]
 107                                         ? nla_get_u32(tb[ZLIB_COMP_METHOD])
 108                                         : Z_DEFLATED,
 109                                 tb[ZLIB_COMP_WINDOWBITS]
 110                                         ? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS])
 111                                         : MAX_WBITS,
 112                                 tb[ZLIB_COMP_MEMLEVEL]
 113                                         ? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL])
 114                                         : DEF_MEM_LEVEL,
 115                                 tb[ZLIB_COMP_STRATEGY]
 116                                         ? nla_get_u32(tb[ZLIB_COMP_STRATEGY])
 117                                         : Z_DEFAULT_STRATEGY);
 118         if (ret != Z_OK) {
 119                 vfree(stream->workspace);
 120                 stream->workspace = NULL;
 121                 return -EINVAL;
 122         }
 123
 124         return 0;
 125 }
 126
 127 static int zlib_compress_init(struct crypto_pcomp *tfm)
 128 {
 129         int ret;
 130         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 131         struct z_stream_s *stream = &dctx->comp_stream;
 132
 133         ret = zlib_deflateReset(stream);
 134         if (ret != Z_OK)
 135                 return -EINVAL;
 136
 137         return 0;
 138 }
 139
 140 static int zlib_compress_update(struct crypto_pcomp *tfm,
 141                                 struct comp_request *req)
 142 {
 143         int ret;
 144         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 145         struct z_stream_s *stream = &dctx->comp_stream;
 146
 147         pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 148         stream->next_in = req->next_in;
 149         stream->avail_in = req->avail_in;
 150         stream->next_out = req->next_out;
 151         stream->avail_out = req->avail_out;
 152
 153         ret = zlib_deflate(stream, Z_NO_FLUSH);
 154         switch (ret) {
 155         case Z_OK:
 156                 break;
 157
 158         case Z_BUF_ERROR:
 159                 pr_debug("zlib_deflate could not make progress\n");
 160                 return -EAGAIN;
 161
 162         default:
 163                 pr_debug("zlib_deflate failed %d\n", ret);
 164                 return -EINVAL;
 165         }
 166
 167         ret = req->avail_out - stream->avail_out;
 168         pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 169                  stream->avail_in, stream->avail_out,
 170                  req->avail_in - stream->avail_in, ret);
 171         req->next_in = stream->next_in;
 172         req->avail_in = stream->avail_in;
 173         req->next_out = stream->next_out;
 174         req->avail_out = stream->avail_out;
 175         return ret;
 176 }
 177
 178 static int zlib_compress_final(struct crypto_pcomp *tfm,
 179                                struct comp_request *req)
 180 {
 181         int ret;
 182         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 183         struct z_stream_s *stream = &dctx->comp_stream;
 184
 185         pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 186         stream->next_in = req->next_in;
 187         stream->avail_in = req->avail_in;
 188         stream->next_out = req->next_out;
 189         stream->avail_out = req->avail_out;
 190
 191         ret = zlib_deflate(stream, Z_FINISH);
 192         if (ret != Z_STREAM_END) {
 193                 pr_debug("zlib_deflate failed %d\n", ret);
 194                 return -EINVAL;
 195         }
 196
 197         ret = req->avail_out - stream->avail_out;
 198         pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 199                  stream->avail_in, stream->avail_out,
 200                  req->avail_in - stream->avail_in, ret);
 201         req->next_in = stream->next_in;
 202         req->avail_in = stream->avail_in;
 203         req->next_out = stream->next_out;
 204         req->avail_out = stream->avail_out;
 205         return ret;
 206 }
 207
 208
 209 static int zlib_decompress_setup(struct crypto_pcomp *tfm, void *params,
 210                                  unsigned int len)
 211 {
 212         struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 213         struct z_stream_s *stream = &ctx->decomp_stream;
 214         struct nlattr *tb[ZLIB_DECOMP_MAX + 1];
 215         int ret = 0;
 216
 217         ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL);
 218         if (ret)
 219                 return ret;
 220
 221         zlib_decomp_exit(ctx);
 222
 223         ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS]
 224                                  ? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS])
 225                                  : DEF_WBITS;
 226
 227         stream->workspace = kzalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 228         if (!stream->workspace)
 229                 return -ENOMEM;
 230
 231         ret = zlib_inflateInit2(stream, ctx->decomp_windowBits);
 232         if (ret != Z_OK) {
 233                 kfree(stream->workspace);
 234                 stream->workspace = NULL;
 235                 return -EINVAL;
 236         }
 237
 238         return 0;
 239 }
 240
 241 static int zlib_decompress_init(struct crypto_pcomp *tfm)
 242 {
 243         int ret;
 244         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 245         struct z_stream_s *stream = &dctx->decomp_stream;
 246
 247         ret = zlib_inflateReset(stream);
 248         if (ret != Z_OK)
 249                 return -EINVAL;
 250
 251         return 0;
 252 }
 253
 254 static int zlib_decompress_update(struct crypto_pcomp *tfm,
 255                                   struct comp_request *req)
 256 {
 257         int ret;
 258         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 259         struct z_stream_s *stream = &dctx->decomp_stream;
 260
 261         pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 262         stream->next_in = req->next_in;
 263         stream->avail_in = req->avail_in;
 264         stream->next_out = req->next_out;
 265         stream->avail_out = req->avail_out;
 266
 267         ret = zlib_inflate(stream, Z_SYNC_FLUSH);
 268         switch (ret) {
 269         case Z_OK:
 270         case Z_STREAM_END:
 271                 break;
 272
 273         case Z_BUF_ERROR:
 274                 pr_debug("zlib_inflate could not make progress\n");
 275                 return -EAGAIN;
 276
 277         default:
 278                 pr_debug("zlib_inflate failed %d\n", ret);
 279                 return -EINVAL;
 280         }
 281
 282         ret = req->avail_out - stream->avail_out;
 283         pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 284                  stream->avail_in, stream->avail_out,
 285                  req->avail_in - stream->avail_in, ret);
 286         req->next_in = stream->next_in;
 287         req->avail_in = stream->avail_in;
 288         req->next_out = stream->next_out;
 289         req->avail_out = stream->avail_out;
 290         return ret;
 291 }
 292
 293 static int zlib_decompress_final(struct crypto_pcomp *tfm,
 294                                  struct comp_request *req)
 295 {
 296         int ret;
 297         struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm));
 298         struct z_stream_s *stream = &dctx->decomp_stream;
 299
 300         pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out);
 301         stream->next_in = req->next_in;
 302         stream->avail_in = req->avail_in;
 303         stream->next_out = req->next_out;
 304         stream->avail_out = req->avail_out;
 305
 306         if (dctx->decomp_windowBits < 0) {
 307                 ret = zlib_inflate(stream, Z_SYNC_FLUSH);
 308                 /*
 309                  * Work around a bug in zlib, which sometimes wants to taste an
 310                  * extra byte when being used in the (undocumented) raw deflate
 311                  * mode. (From USAGI).
 312                  */
 313                 if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
 314                         const void *saved_next_in = stream->next_in;
 315                         u8 zerostuff = 0;
 316
 317                         stream->next_in = &zerostuff;
 318                         stream->avail_in = 1;
 319                         ret = zlib_inflate(stream, Z_FINISH);
 320                         stream->next_in = saved_next_in;
 321                         stream->avail_in = 0;
 322                 }
 323         } else
 324                 ret = zlib_inflate(stream, Z_FINISH);
 325         if (ret != Z_STREAM_END) {
 326                 pr_debug("zlib_inflate failed %d\n", ret);
 327                 return -EINVAL;
 328         }
 329
 330         ret = req->avail_out - stream->avail_out;
 331         pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n",
 332                  stream->avail_in, stream->avail_out,
 333                  req->avail_in - stream->avail_in, ret);
 334         req->next_in = stream->next_in;
 335         req->avail_in = stream->avail_in;
 336         req->next_out = stream->next_out;
 337         req->avail_out = stream->avail_out;
 338         return ret;
 339 }
 340
 341
 342 static struct pcomp_alg zlib_alg = {
 343         .compress_setup         = zlib_compress_setup,
 344         .compress_init          = zlib_compress_init,
 345         .compress_update        = zlib_compress_update,
 346         .compress_final         = zlib_compress_final,
 347         .decompress_setup       = zlib_decompress_setup,
 348         .decompress_init        = zlib_decompress_init,
 349         .decompress_update      = zlib_decompress_update,
 350         .decompress_final       = zlib_decompress_final,
 351
 352         .base                   = {
 353                 .cra_name       = "zlib",
 354                 .cra_flags      = CRYPTO_ALG_TYPE_PCOMPRESS,
 355                 .cra_ctxsize    = sizeof(struct zlib_ctx),
 356                 .cra_module     = THIS_MODULE,
 357                 .cra_init       = zlib_init,
 358                 .cra_exit       = zlib_exit,
 359         }
 360 };
 361
 362 static int __init zlib_mod_init(void)
 363 {
 364         return crypto_register_pcomp(&zlib_alg);
 365 }
 366
 367 static void __exit zlib_mod_fini(void)
 368 {
 369         crypto_unregister_pcomp(&zlib_alg);
 370 }
 371
 372 module_init(zlib_mod_init);
 373 module_exit(zlib_mod_fini);
 374
 375 MODULE_LICENSE("GPL");
 376 MODULE_DESCRIPTION("Zlib Compression Algorithm");
 377 MODULE_AUTHOR("Sony Corporation");