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