CMakeLua/Utilities/cmcurl/content_encoding.c

   1 /***************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel@haxx.se>, et al.
   9  *
  10  * This software is licensed as described in the file COPYING, which
  11  * you should have received as part of this distribution. The terms
  12  * are also available at http://curl.haxx.se/docs/copyright.html.
  13  *
  14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  15  * copies of the Software, and permit persons to whom the Software is
  16  * furnished to do so, under the terms of the COPYING file.
  17  *
  18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19  * KIND, either express or implied.
  20  *
  21  * $Id: content_encoding.c,v 1.2 2007/03/15 19:22:13 andy Exp $
  22  ***************************************************************************/
  23
  24 #include "setup.h"
  25
  26 #ifdef HAVE_LIBZ
  27
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 #include "urldata.h"
  32 #include <curl/curl.h>
  33 #include "sendf.h"
  34 #include "content_encoding.h"
  35 #include "memory.h"
  36
  37 #include "memdebug.h"
  38
  39 /* Comment this out if zlib is always going to be at least ver. 1.2.0.4
  40    (doing so will reduce code size slightly). */
  41 #define OLD_ZLIB_SUPPORT 1
  42
  43 #define DSIZ 0x10000             /* buffer size for decompressed data */
  44
  45 #define GZIP_MAGIC_0 0x1f
  46 #define GZIP_MAGIC_1 0x8b
  47
  48 /* gzip flag byte */
  49 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
  50 #define HEAD_CRC     0x02 /* bit 1 set: header CRC present */
  51 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
  52 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
  53 #define COMMENT      0x10 /* bit 4 set: file comment present */
  54 #define RESERVED     0xE0 /* bits 5..7: reserved */
  55
  56 enum zlibState {
  57   ZLIB_UNINIT,          /* uninitialized */
  58   ZLIB_INIT,            /* initialized */
  59   ZLIB_GZIP_HEADER,     /* reading gzip header */
  60   ZLIB_GZIP_INFLATING,  /* inflating gzip stream */
  61   ZLIB_INIT_GZIP        /* initialized in transparent gzip mode */
  62 };
  63
  64 static CURLcode
  65 process_zlib_error(struct connectdata *conn, z_stream *z)
  66 {
  67   struct SessionHandle *data = conn->data;
  68   if (z->msg)
  69     failf (data, "Error while processing content unencoding: %s",
  70            z->msg);
  71   else
  72     failf (data, "Error while processing content unencoding: "
  73            "Unknown failure within decompression software.");
  74
  75   return CURLE_BAD_CONTENT_ENCODING;
  76 }
  77
  78 static CURLcode
  79 exit_zlib(z_stream *z, bool *zlib_init, CURLcode result)
  80 {
  81   inflateEnd(z);
  82   *zlib_init = ZLIB_UNINIT;
  83   return result;
  84 }
  85
  86 static CURLcode
  87 inflate_stream(struct connectdata *conn,
  88                struct Curl_transfer_keeper *k)
  89 {
  90   int allow_restart = 1;
  91   z_stream *z = &k->z;          /* zlib state structure */
  92   uInt nread = z->avail_in;
  93   Bytef *orig_in = z->next_in;
  94   int status;                   /* zlib status */
  95   CURLcode result = CURLE_OK;   /* Curl_client_write status */
  96   char *decomp;                 /* Put the decompressed data here. */
  97
  98   /* Dynamically allocate a buffer for decompression because it's uncommonly
  99      large to hold on the stack */
 100   decomp = (char*)malloc(DSIZ);
 101   if (decomp == NULL) {
 102     return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
 103   }
 104
 105   /* because the buffer size is fixed, iteratively decompress and transfer to
 106      the client via client_write. */
 107   for (;;) {
 108     /* (re)set buffer for decompressed output for every iteration */
 109     z->next_out = (Bytef *)decomp;
 110     z->avail_out = DSIZ;
 111
 112     status = inflate(z, Z_SYNC_FLUSH);
 113     if (status == Z_OK || status == Z_STREAM_END) {
 114       allow_restart = 0;
 115       if(DSIZ - z->avail_out) {
 116         result = Curl_client_write(conn, CLIENTWRITE_BODY, decomp,
 117                                    DSIZ - z->avail_out);
 118         /* if !CURLE_OK, clean up, return */
 119         if (result) {
 120           free(decomp);
 121           return exit_zlib(z, &k->zlib_init, result);
 122         }
 123       }
 124
 125       /* Done? clean up, return */
 126       if (status == Z_STREAM_END) {
 127         free(decomp);
 128         if (inflateEnd(z) == Z_OK)
 129           return exit_zlib(z, &k->zlib_init, result);
 130         else
 131           return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
 132       }
 133
 134       /* Done with these bytes, exit */
 135       if (status == Z_OK && z->avail_in == 0) {
 136         free(decomp);
 137         return result;
 138       }
 139     }
 140     else if (allow_restart && status == Z_DATA_ERROR) {
 141       /* some servers seem to not generate zlib headers, so this is an attempt
 142          to fix and continue anyway */
 143
 144       inflateReset(z);
 145       if (inflateInit2(z, -MAX_WBITS) != Z_OK) {
 146         return process_zlib_error(conn, z);
 147       }
 148       z->next_in = orig_in;
 149       z->avail_in = nread;
 150       allow_restart = 0;
 151       continue;
 152     }
 153     else {                      /* Error; exit loop, handle below */
 154       free(decomp);
 155       return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
 156     }
 157   }
 158   /* Will never get here */
 159 }
 160
 161 CURLcode
 162 Curl_unencode_deflate_write(struct connectdata *conn,
 163                             struct Curl_transfer_keeper *k,
 164                             ssize_t nread)
 165 {
 166   z_stream *z = &k->z;          /* zlib state structure */
 167
 168   /* Initialize zlib? */
 169   if (k->zlib_init == ZLIB_UNINIT) {
 170     z->zalloc = (alloc_func)Z_NULL;
 171     z->zfree = (free_func)Z_NULL;
 172     z->opaque = 0;
 173     z->next_in = NULL;
 174     z->avail_in = 0;
 175     if (inflateInit(z) != Z_OK)
 176       return process_zlib_error(conn, z);
 177     k->zlib_init = ZLIB_INIT;
 178   }
 179
 180   /* Set the compressed input when this function is called */
 181   z->next_in = (Bytef *)k->str;
 182   z->avail_in = (uInt)nread;
 183
 184   /* Now uncompress the data */
 185   return inflate_stream(conn, k);
 186 }
 187
 188 #ifdef OLD_ZLIB_SUPPORT
 189 /* Skip over the gzip header */
 190 static enum {
 191   GZIP_OK,
 192   GZIP_BAD,
 193   GZIP_UNDERFLOW
 194 } check_gzip_header(unsigned char const *data, ssize_t len, ssize_t *headerlen)
 195 {
 196   int method, flags;
 197   const ssize_t totallen = len;
 198
 199   /* The shortest header is 10 bytes */
 200   if (len < 10)
 201     return GZIP_UNDERFLOW;
 202
 203   if ((data[0] != GZIP_MAGIC_0) || (data[1] != GZIP_MAGIC_1))
 204     return GZIP_BAD;
 205
 206   method = data[2];
 207   flags = data[3];
 208
 209   if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
 210     /* Can't handle this compression method or unknown flag */
 211     return GZIP_BAD;
 212   }
 213
 214   /* Skip over time, xflags, OS code and all previous bytes */
 215   len -= 10;
 216   data += 10;
 217
 218   if (flags & EXTRA_FIELD) {
 219     ssize_t extra_len;
 220
 221     if (len < 2)
 222       return GZIP_UNDERFLOW;
 223
 224     extra_len = (data[1] << 8) | data[0];
 225
 226     if (len < (extra_len+2))
 227       return GZIP_UNDERFLOW;
 228
 229     len -= (extra_len + 2);
 230     data += (extra_len + 2);
 231   }
 232
 233   if (flags & ORIG_NAME) {
 234     /* Skip over NUL-terminated file name */
 235     while (len && *data) {
 236       --len;
 237       ++data;
 238     }
 239     if (!len || *data)
 240       return GZIP_UNDERFLOW;
 241
 242     /* Skip over the NUL */
 243     --len;
 244     ++data;
 245   }
 246
 247   if (flags & COMMENT) {
 248     /* Skip over NUL-terminated comment */
 249     while (len && *data) {
 250       --len;
 251       ++data;
 252     }
 253     if (!len || *data)
 254       return GZIP_UNDERFLOW;
 255
 256     /* Skip over the NUL */
 257     --len;
 258     ++data;
 259   }
 260
 261   if (flags & HEAD_CRC) {
 262     if (len < 2)
 263       return GZIP_UNDERFLOW;
 264
 265     len -= 2;
 266     data += 2;
 267   }
 268
 269   *headerlen = totallen - len;
 270   return GZIP_OK;
 271 }
 272 #endif
 273
 274 CURLcode
 275 Curl_unencode_gzip_write(struct connectdata *conn,
 276                          struct Curl_transfer_keeper *k,
 277                          ssize_t nread)
 278 {
 279   z_stream *z = &k->z;          /* zlib state structure */
 280
 281   /* Initialize zlib? */
 282   if (k->zlib_init == ZLIB_UNINIT) {
 283     z->zalloc = (alloc_func)Z_NULL;
 284     z->zfree = (free_func)Z_NULL;
 285     z->opaque = 0;
 286     z->next_in = NULL;
 287     z->avail_in = 0;
 288
 289     if (strcmp(zlibVersion(), "1.2.0.4") >= 0) {
 290         /* zlib ver. >= 1.2.0.4 supports transparent gzip decompressing */
 291         if (inflateInit2(z, MAX_WBITS+32) != Z_OK) {
 292           return process_zlib_error(conn, z);
 293         }
 294         k->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */
 295
 296     } else {
 297         /* we must parse the gzip header ourselves */
 298         if (inflateInit2(z, -MAX_WBITS) != Z_OK) {
 299           return process_zlib_error(conn, z);
 300         }
 301         k->zlib_init = ZLIB_INIT;   /* Initial call state */
 302     }
 303   }
 304
 305   if (k->zlib_init == ZLIB_INIT_GZIP) {
 306      /* Let zlib handle the gzip decompression entirely */
 307      z->next_in = (Bytef *)k->str;
 308      z->avail_in = (uInt)nread;
 309      /* Now uncompress the data */
 310      return inflate_stream(conn, k);
 311   }
 312
 313 #ifndef OLD_ZLIB_SUPPORT
 314   /* Support for old zlib versions is compiled away and we are running with
 315      an old version, so return an error. */
 316   return exit_zlib(z, &k->zlib_init, CURLE_FUNCTION_NOT_FOUND);
 317
 318 #else
 319   /* This next mess is to get around the potential case where there isn't
 320    * enough data passed in to skip over the gzip header.  If that happens, we
 321    * malloc a block and copy what we have then wait for the next call.  If
 322    * there still isn't enough (this is definitely a worst-case scenario), we
 323    * make the block bigger, copy the next part in and keep waiting.
 324    *
 325    * This is only required with zlib versions < 1.2.0.4 as newer versions
 326    * can handle the gzip header themselves.
 327    */
 328
 329   switch (k->zlib_init) {
 330   /* Skip over gzip header? */
 331   case ZLIB_INIT:
 332   {
 333     /* Initial call state */
 334     ssize_t hlen;
 335
 336     switch (check_gzip_header((unsigned char *)k->str, nread, &hlen)) {
 337     case GZIP_OK:
 338       z->next_in = (Bytef *)k->str + hlen;
 339       z->avail_in = (uInt)(nread - hlen);
 340       k->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */
 341       break;
 342
 343     case GZIP_UNDERFLOW:
 344       /* We need more data so we can find the end of the gzip header.  It's
 345        * possible that the memory block we malloc here will never be freed if
 346        * the transfer abruptly aborts after this point.  Since it's unlikely
 347        * that circumstances will be right for this code path to be followed in
 348        * the first place, and it's even more unlikely for a transfer to fail
 349        * immediately afterwards, it should seldom be a problem.
 350        */
 351       z->avail_in = (uInt)nread;
 352       z->next_in = malloc(z->avail_in);
 353       if (z->next_in == NULL) {
 354         return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
 355       }
 356       memcpy(z->next_in, k->str, z->avail_in);
 357       k->zlib_init = ZLIB_GZIP_HEADER;   /* Need more gzip header data state */
 358       /* We don't have any data to inflate yet */
 359       return CURLE_OK;
 360
 361     case GZIP_BAD:
 362     default:
 363       return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
 364     }
 365
 366   }
 367   break;
 368
 369   case ZLIB_GZIP_HEADER:
 370   {
 371     /* Need more gzip header data state */
 372     ssize_t hlen;
 373     unsigned char *oldblock = z->next_in;
 374
 375     z->avail_in += nread;
 376     z->next_in = realloc(z->next_in, z->avail_in);
 377     if (z->next_in == NULL) {
 378       free(oldblock);
 379       return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
 380     }
 381     /* Append the new block of data to the previous one */
 382     memcpy(z->next_in + z->avail_in - nread, k->str, nread);
 383
 384     switch (check_gzip_header(z->next_in, z->avail_in, &hlen)) {
 385     case GZIP_OK:
 386       /* This is the zlib stream data */
 387       free(z->next_in);
 388       /* Don't point into the malloced block since we just freed it */
 389       z->next_in = (Bytef *)k->str + hlen + nread - z->avail_in;
 390       z->avail_in = (uInt)(z->avail_in - hlen);
 391       k->zlib_init = ZLIB_GZIP_INFLATING;   /* Inflating stream state */
 392       break;
 393
 394     case GZIP_UNDERFLOW:
 395       /* We still don't have any data to inflate! */
 396       return CURLE_OK;
 397
 398     case GZIP_BAD:
 399     default:
 400       free(z->next_in);
 401       return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
 402     }
 403
 404   }
 405   break;
 406
 407   case ZLIB_GZIP_INFLATING:
 408   default:
 409     /* Inflating stream state */
 410     z->next_in = (Bytef *)k->str;
 411     z->avail_in = (uInt)nread;
 412     break;
 413   }
 414
 415   if (z->avail_in == 0) {
 416     /* We don't have any data to inflate; wait until next time */
 417     return CURLE_OK;
 418   }
 419
 420   /* We've parsed the header, now uncompress the data */
 421   return inflate_stream(conn, k);
 422 #endif
 423 }
 424 #endif /* HAVE_LIBZ */