src/fs/fs_download.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009, 2010 Christian Grothoff (and other contributing authors)
   4
   5      GNUnet is free software; you can redistribute it and/or modify
   6      it under the terms of the GNU General Public License as published
   7      by the Free Software Foundation; either version 2, or (at your
   8      option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  11      WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      General Public License for more details.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20 /**
  21  * @file fs/fs_download.c
  22  * @brief download methods
  23  * @author Christian Grothoff
  24  *
  25  * TODO:
  26  * - handle recursive downloads (need directory &
  27  *   fs-level download-parallelism management)
  28  * - location URI suppport (can wait, easy)
  29  * - check if blocks exist already (can wait, easy)
  30  * - check if iblocks can be computed from existing blocks (can wait, hard)
  31  * - persistence (can wait)
  32  */
  33 #include "platform.h"
  34 #include "gnunet_constants.h"
  35 #include "gnunet_fs_service.h"
  36 #include "fs.h"
  37 #include "fs_tree.h"
  38
  39 #define DEBUG_DOWNLOAD GNUNET_NO
  40
  41 /**
  42  * Determine if the given download (options and meta data) should cause
  43  * use to try to do a recursive download.
  44  */
  45 static int
  46 is_recursive_download (struct GNUNET_FS_DownloadContext *dc)
  47 {
  48   return  (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_RECURSIVE)) &&
  49     ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (dc->meta)) ||
  50       ( (dc->meta == NULL) &&
  51         ( (NULL == dc->filename) ||
  52           ( (strlen (dc->filename) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
  53             (NULL !=
  54              strstr (dc->filename + strlen(dc->filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
  55                      GNUNET_FS_DIRECTORY_EXT)) ) ) ) );
  56 }
  57
  58
  59 /**
  60  * We're storing the IBLOCKS after the DBLOCKS on disk (so that we
  61  * only have to truncate the file once we're done).
  62  *
  63  * Given the offset of a block (with respect to the DBLOCKS) and its
  64  * depth, return the offset where we would store this block in the
  65  * file.
  66  *
  67  * @param fsize overall file size
  68  * @param off offset of the block in the file
  69  * @param depth depth of the block in the tree
  70  * @param treedepth maximum depth of the tree
  71  * @return off for DBLOCKS (depth == treedepth),
  72  *         otherwise an offset past the end
  73  *         of the file that does not overlap
  74  *         with the range for any other block
  75  */
  76 static uint64_t
  77 compute_disk_offset (uint64_t fsize,
  78                      uint64_t off,
  79                      unsigned int depth,
  80                      unsigned int treedepth)
  81 {
  82   unsigned int i;
  83   uint64_t lsize; /* what is the size of all IBlocks for depth "i"? */
  84   uint64_t loff; /* where do IBlocks for depth "i" start? */
  85   unsigned int ioff; /* which IBlock corresponds to "off" at depth "i"? */
  86
  87   if (depth == treedepth)
  88     return off;
  89   /* first IBlocks start at the end of file, rounded up
  90      to full DBLOCK_SIZE */
  91   loff = ((fsize + DBLOCK_SIZE - 1) / DBLOCK_SIZE) * DBLOCK_SIZE;
  92   lsize = ( (fsize + DBLOCK_SIZE-1) / DBLOCK_SIZE) * sizeof (struct ContentHashKey);
  93   GNUNET_assert (0 == (off % DBLOCK_SIZE));
  94   ioff = (off / DBLOCK_SIZE);
  95   for (i=treedepth-1;i>depth;i--)
  96     {
  97       loff += lsize;
  98       lsize = (lsize + CHK_PER_INODE - 1) / CHK_PER_INODE;
  99       GNUNET_assert (lsize > 0);
 100       GNUNET_assert (0 == (ioff % CHK_PER_INODE));
 101       ioff /= CHK_PER_INODE;
 102     }
 103   return loff + ioff * sizeof (struct ContentHashKey);
 104 }
 105
 106
 107 /**
 108  * Given a file of the specified treedepth and a block at the given
 109  * offset and depth, calculate the offset for the CHK at the given
 110  * index.
 111  *
 112  * @param offset the offset of the first
 113  *        DBLOCK in the subtree of the
 114  *        identified IBLOCK
 115  * @param depth the depth of the IBLOCK in the tree
 116  * @param treedepth overall depth of the tree
 117  * @param k which CHK in the IBLOCK are we
 118  *        talking about
 119  * @return offset if k=0, otherwise an appropriately
 120  *         larger value (i.e., if depth = treedepth-1,
 121  *         the returned value should be offset+DBLOCK_SIZE)
 122  */
 123 static uint64_t
 124 compute_dblock_offset (uint64_t offset,
 125                        unsigned int depth,
 126                        unsigned int treedepth,
 127                        unsigned int k)
 128 {
 129   unsigned int i;
 130   uint64_t lsize; /* what is the size of the sum of all DBlocks
 131                      that a CHK at depth i corresponds to? */
 132
 133   if (depth == treedepth)
 134     return offset;
 135   lsize = DBLOCK_SIZE;
 136   for (i=treedepth-1;i>depth;i--)
 137     lsize *= CHK_PER_INODE;
 138   return offset + k * lsize;
 139 }
 140
 141
 142 /**
 143  * Fill in all of the generic fields for
 144  * a download event.
 145  *
 146  * @param pi structure to fill in
 147  * @param dc overall download context
 148  */
 149 static void
 150 make_download_status (struct GNUNET_FS_ProgressInfo *pi,
 151                       struct GNUNET_FS_DownloadContext *dc)
 152 {
 153   pi->value.download.dc = dc;
 154   pi->value.download.cctx
 155     = dc->client_info;
 156   pi->value.download.pctx
 157     = (dc->parent == NULL) ? NULL : dc->parent->client_info;
 158   pi->value.download.uri
 159     = dc->uri;
 160   pi->value.download.filename
 161     = dc->filename;
 162   pi->value.download.size
 163     = dc->length;
 164   pi->value.download.duration
 165     = GNUNET_TIME_absolute_get_duration (dc->start_time);
 166   pi->value.download.completed
 167     = dc->completed;
 168   pi->value.download.anonymity
 169     = dc->anonymity;
 170   pi->value.download.eta
 171     = GNUNET_TIME_calculate_eta (dc->start_time,
 172                                  dc->completed,
 173                                  dc->length);
 174 }
 175
 176 /**
 177  * We're ready to transmit a search request to the
 178  * file-sharing service.  Do it.  If there is
 179  * more than one request pending, try to send
 180  * multiple or request another transmission.
 181  *
 182  * @param cls closure
 183  * @param size number of bytes available in buf
 184  * @param buf where the callee should write the message
 185  * @return number of bytes written to buf
 186  */
 187 static size_t
 188 transmit_download_request (void *cls,
 189                            size_t size,
 190                            void *buf);
 191
 192
 193 /**
 194  * Closure for iterator processing results.
 195  */
 196 struct ProcessResultClosure
 197 {
 198
 199   /**
 200    * Hash of data.
 201    */
 202   GNUNET_HashCode query;
 203
 204   /**
 205    * Data found in P2P network.
 206    */
 207   const void *data;
 208
 209   /**
 210    * Our download context.
 211    */
 212   struct GNUNET_FS_DownloadContext *dc;
 213
 214   /**
 215    * Number of bytes in data.
 216    */
 217   size_t size;
 218
 219   /**
 220    * Type of data.
 221    */
 222   uint32_t type;
 223
 224   /**
 225    * Flag to indicate if this block should be stored on disk.
 226    */
 227   int do_store;
 228
 229 };
 230
 231
 232 /**
 233  * Iterator over entries in the pending requests in the 'active' map for the
 234  * reply that we just got.
 235  *
 236  * @param cls closure (our 'struct ProcessResultClosure')
 237  * @param key query for the given value / request
 238  * @param value value in the hash map (a 'struct DownloadRequest')
 239  * @return GNUNET_YES (we should continue to iterate); unless serious error
 240  */
 241 static int
 242 process_result_with_request (void *cls,
 243                              const GNUNET_HashCode * key,
 244                              void *value);
 245
 246
 247
 248 /**
 249  * Schedule the download of the specified block in the tree.
 250  *
 251  * @param dc overall download this block belongs to
 252  * @param chk content-hash-key of the block
 253  * @param offset offset of the block in the file
 254  *         (for IBlocks, the offset is the lowest
 255  *          offset of any DBlock in the subtree under
 256  *          the IBlock)
 257  * @param depth depth of the block, 0 is the root of the tree
 258  */
 259 static void
 260 schedule_block_download (struct GNUNET_FS_DownloadContext *dc,
 261                          const struct ContentHashKey *chk,
 262                          uint64_t offset,
 263                          unsigned int depth)
 264 {
 265   struct DownloadRequest *sm;
 266   uint64_t total;
 267   uint64_t off;
 268   size_t len;
 269   char block[DBLOCK_SIZE];
 270   GNUNET_HashCode key;
 271   struct ProcessResultClosure prc;
 272
 273 #if DEBUG_DOWNLOAD
 274   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 275               "Scheduling download at offset %llu and depth %u for `%s'\n",
 276               (unsigned long long) offset,
 277               depth,
 278               GNUNET_h2s (&chk->query));
 279 #endif
 280   total = GNUNET_ntohll (dc->uri->data.chk.file_length);
 281   off = compute_disk_offset (total,
 282                              offset,
 283                              depth,
 284                              dc->treedepth);
 285   len = GNUNET_FS_tree_calculate_block_size (total,
 286                                              dc->treedepth,
 287                                              offset,
 288                                              depth);
 289   sm = GNUNET_malloc (sizeof (struct DownloadRequest));
 290   sm->chk = *chk;
 291   sm->offset = offset;
 292   sm->depth = depth;
 293   sm->is_pending = GNUNET_YES;
 294   sm->next = dc->pending;
 295   dc->pending = sm;
 296   GNUNET_CONTAINER_multihashmap_put (dc->active,
 297                                      &chk->query,
 298                                      sm,
 299                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
 300
 301   if ( (dc->old_file_size > off) &&
 302        (dc->handle != NULL) &&
 303        (off  ==
 304         GNUNET_DISK_file_seek (dc->handle,
 305                                off,
 306                                GNUNET_DISK_SEEK_SET) ) &&
 307        (len ==
 308         GNUNET_DISK_file_read (dc->handle,
 309                                block,
 310                                len)) )
 311     {
 312       if (0 == memcmp (&key,
 313                        &chk->key,
 314                        sizeof (GNUNET_HashCode)))
 315         {
 316           char enc[len];
 317           struct GNUNET_CRYPTO_AesSessionKey sk;
 318           struct GNUNET_CRYPTO_AesInitializationVector iv;
 319           GNUNET_HashCode query;
 320
 321           GNUNET_CRYPTO_hash_to_aes_key (&key, &sk, &iv);
 322           GNUNET_CRYPTO_aes_encrypt (block, len,
 323                                      &sk,
 324                                      &iv,
 325                                      enc);
 326           GNUNET_CRYPTO_hash (enc, len, &query);
 327           if (0 == memcmp (&query,
 328                            &chk->query,
 329                            sizeof (GNUNET_HashCode)))
 330             {
 331               /* already got it! */
 332               prc.dc = dc;
 333               prc.data = enc;
 334               prc.size = len;
 335               prc.type = (dc->treedepth == depth)
 336                 ? GNUNET_DATASTORE_BLOCKTYPE_DBLOCK
 337                 : GNUNET_DATASTORE_BLOCKTYPE_IBLOCK;
 338               prc.query = chk->query;
 339               prc.do_store = GNUNET_NO; /* useless */
 340               process_result_with_request (&prc,
 341                                            &key,
 342                                            sm);
 343             }
 344           else
 345             {
 346               GNUNET_break_op (0);
 347             }
 348           return;
 349         }
 350     }
 351   if (depth < dc->treedepth)
 352     {
 353       // FIXME: try if we could
 354       // reconstitute this IBLOCK
 355       // from the existing blocks on disk (can wait)
 356       // (read block(s), encode, compare with
 357       // query; if matches, simply return)
 358     }
 359
 360   if ( (dc->th == NULL) &&
 361        (dc->client != NULL) )
 362     dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
 363                                                   sizeof (struct SearchMessage),
 364                                                   GNUNET_CONSTANTS_SERVICE_TIMEOUT,
 365                                                   GNUNET_NO,
 366                                                   &transmit_download_request,
 367                                                   dc);
 368 }
 369
 370
 371
 372 /**
 373  * Suggest a filename based on given metadata.
 374  *
 375  * @param md given meta data
 376  * @return NULL if meta data is useless for suggesting a filename
 377  */
 378 char *
 379 GNUNET_FS_meta_data_suggest_filename (const struct GNUNET_CONTAINER_MetaData *md)
 380 {
 381   static const char *mimeMap[][2] = {
 382     {"application/bz2", ".bz2"},
 383     {"application/gnunet-directory", ".gnd"},
 384     {"application/java", ".class"},
 385     {"application/msword", ".doc"},
 386     {"application/ogg", ".ogg"},
 387     {"application/pdf", ".pdf"},
 388     {"application/pgp-keys", ".key"},
 389     {"application/pgp-signature", ".pgp"},
 390     {"application/postscript", ".ps"},
 391     {"application/rar", ".rar"},
 392     {"application/rtf", ".rtf"},
 393     {"application/xml", ".xml"},
 394     {"application/x-debian-package", ".deb"},
 395     {"application/x-dvi", ".dvi"},
 396     {"applixation/x-flac", ".flac"},
 397     {"applixation/x-gzip", ".gz"},
 398     {"application/x-java-archive", ".jar"},
 399     {"application/x-java-vm", ".class"},
 400     {"application/x-python-code", ".pyc"},
 401     {"application/x-redhat-package-manager", ".rpm"},
 402     {"application/x-rpm", ".rpm"},
 403     {"application/x-tar", ".tar"},
 404     {"application/x-tex-pk", ".pk"},
 405     {"application/x-texinfo", ".texinfo"},
 406     {"application/x-xcf", ".xcf"},
 407     {"application/x-xfig", ".xfig"},
 408     {"application/zip", ".zip"},
 409
 410     {"audio/midi", ".midi"},
 411     {"audio/mpeg", ".mp3"},
 412     {"audio/real", ".rm"},
 413     {"audio/x-wav", ".wav"},
 414
 415     {"image/gif", ".gif"},
 416     {"image/jpeg", ".jpg"},
 417     {"image/pcx", ".pcx"},
 418     {"image/png", ".png"},
 419     {"image/tiff", ".tiff"},
 420     {"image/x-ms-bmp", ".bmp"},
 421     {"image/x-xpixmap", ".xpm"},
 422
 423     {"text/css", ".css"},
 424     {"text/html", ".html"},
 425     {"text/plain", ".txt"},
 426     {"text/rtf", ".rtf"},
 427     {"text/x-c++hdr", ".h++"},
 428     {"text/x-c++src", ".c++"},
 429     {"text/x-chdr", ".h"},
 430     {"text/x-csrc", ".c"},
 431     {"text/x-java", ".java"},
 432     {"text/x-moc", ".moc"},
 433     {"text/x-pascal", ".pas"},
 434     {"text/x-perl", ".pl"},
 435     {"text/x-python", ".py"},
 436     {"text/x-tex", ".tex"},
 437
 438     {"video/avi", ".avi"},
 439     {"video/mpeg", ".mpeg"},
 440     {"video/quicktime", ".qt"},
 441     {"video/real", ".rm"},
 442     {"video/x-msvideo", ".avi"},
 443     {NULL, NULL},
 444   };
 445   char *ret;
 446   unsigned int i;
 447   char *mime;
 448   char *base;
 449   const char *ext;
 450
 451   ret = GNUNET_CONTAINER_meta_data_get_by_type (md,
 452                                                 EXTRACTOR_METATYPE_FILENAME);
 453   if (ret != NULL)
 454     return ret;
 455   ext = NULL;
 456   mime = GNUNET_CONTAINER_meta_data_get_by_type (md,
 457                                                  EXTRACTOR_METATYPE_MIMETYPE);
 458   if (mime != NULL)
 459     {
 460       i = 0;
 461       while ( (mimeMap[i][0] != NULL) &&
 462               (0 != strcmp (mime, mimeMap[i][0])))
 463         i++;
 464       if (mimeMap[i][1] == NULL)
 465         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG |
 466                     GNUNET_ERROR_TYPE_BULK,
 467                     _("Did not find mime type `%s' in extension list.\n"),
 468                     mime);
 469       else
 470         ext = mimeMap[i][1];
 471       GNUNET_free (mime);
 472     }
 473   base = GNUNET_CONTAINER_meta_data_get_first_by_types (md,
 474                                                         EXTRACTOR_METATYPE_TITLE,
 475                                                         EXTRACTOR_METATYPE_BOOK_TITLE,
 476                                                         EXTRACTOR_METATYPE_ORIGINAL_TITLE,
 477                                                         EXTRACTOR_METATYPE_PACKAGE_NAME,
 478                                                         EXTRACTOR_METATYPE_URL,
 479                                                         EXTRACTOR_METATYPE_URI,
 480                                                         EXTRACTOR_METATYPE_DESCRIPTION,
 481                                                         EXTRACTOR_METATYPE_ISRC,
 482                                                         EXTRACTOR_METATYPE_JOURNAL_NAME,
 483                                                         EXTRACTOR_METATYPE_AUTHOR_NAME,
 484                                                         EXTRACTOR_METATYPE_SUBJECT,
 485                                                         EXTRACTOR_METATYPE_ALBUM,
 486                                                         EXTRACTOR_METATYPE_ARTIST,
 487                                                         EXTRACTOR_METATYPE_KEYWORDS,
 488                                                         EXTRACTOR_METATYPE_COMMENT,
 489                                                         EXTRACTOR_METATYPE_UNKNOWN,
 490                                                         -1);
 491   if ( (base == NULL) &&
 492        (ext == NULL) )
 493     return NULL;
 494   if (base == NULL)
 495     return GNUNET_strdup (ext);
 496   if (ext == NULL)
 497     return base;
 498   GNUNET_asprintf (&ret,
 499                    "%s%s",
 500                    base,
 501                    ext);
 502   GNUNET_free (base);
 503   return ret;
 504 }
 505
 506
 507 /**
 508  * We've lost our connection with the FS service.
 509  * Re-establish it and re-transmit all of our
 510  * pending requests.
 511  *
 512  * @param dc download context that is having trouble
 513  */
 514 static void
 515 try_reconnect (struct GNUNET_FS_DownloadContext *dc);
 516
 517
 518 /**
 519  * We found an entry in a directory.  Check if the respective child
 520  * already exists and if not create the respective child download.
 521  *
 522  * @param cls the parent download
 523  * @param filename name of the file in the directory
 524  * @param uri URI of the file (CHK or LOC)
 525  * @param meta meta data of the file
 526  * @param length number of bytes in data
 527  * @param data contents of the file (or NULL if they were not inlined)
 528  */
 529 static void
 530 trigger_recursive_download (void *cls,
 531                             const char *filename,
 532                             const struct GNUNET_FS_Uri *uri,
 533                             const struct GNUNET_CONTAINER_MetaData *meta,
 534                             size_t length,
 535                             const void *data)
 536 {
 537   struct GNUNET_FS_DownloadContext *dc = cls;
 538   struct GNUNET_FS_DownloadContext *cpos;
 539   struct GNUNET_DISK_FileHandle *fh;
 540   char *fn;
 541   char *us;
 542   char *ext;
 543   char *dn;
 544   char *full_name;
 545
 546   if (NULL == uri)
 547     return; /* entry for the directory itself */
 548   cpos = dc->child_head;
 549   while (cpos != NULL)
 550     {
 551       if ( (GNUNET_FS_uri_test_equal (uri,
 552                                       cpos->uri)) ||
 553            ( (filename != NULL) &&
 554              (0 == strcmp (cpos->filename,
 555                            filename)) ) )
 556         break;
 557       cpos = cpos->next;
 558     }
 559   if (cpos != NULL)
 560     return; /* already exists */
 561   fn = NULL;
 562   if (NULL == filename)
 563     {
 564       fn = GNUNET_FS_meta_data_suggest_filename (meta);
 565       if (fn == NULL)
 566         {
 567           us = GNUNET_FS_uri_to_string (uri);
 568           fn = GNUNET_strdup (&us [strlen (GNUNET_FS_URI_PREFIX
 569                                            GNUNET_FS_URI_CHK_INFIX)]);
 570           GNUNET_free (us);
 571         }
 572       else if (fn[0] == '.')
 573         {
 574           ext = fn;
 575           us = GNUNET_FS_uri_to_string (uri);
 576           GNUNET_asprintf (&fn,
 577                            "%s%s",
 578                            &us[strlen (GNUNET_FS_URI_PREFIX
 579                                        GNUNET_FS_URI_CHK_INFIX)], ext);
 580           GNUNET_free (ext);
 581           GNUNET_free (us);
 582         }
 583       filename = fn;
 584     }
 585   if (dc->filename == NULL)
 586     {
 587       full_name = NULL;
 588     }
 589   else
 590     {
 591       dn = GNUNET_strdup (dc->filename);
 592       GNUNET_break ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
 593                      (NULL !=
 594                       strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
 595                               GNUNET_FS_DIRECTORY_EXT)) );
 596       if ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
 597            (NULL !=
 598             strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
 599                     GNUNET_FS_DIRECTORY_EXT)) )
 600         dn[strlen(dn) - strlen (GNUNET_FS_DIRECTORY_EXT)] = '\0';
 601       if ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (meta)) &&
 602            ( (strlen (filename) < strlen (GNUNET_FS_DIRECTORY_EXT)) ||
 603              (NULL ==
 604               strstr (filename + strlen(filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
 605                       GNUNET_FS_DIRECTORY_EXT)) ) )
 606         {
 607           GNUNET_asprintf (&full_name,
 608                            "%s%s%s%s",
 609                            dn,
 610                            DIR_SEPARATOR_STR,
 611                            filename,
 612                            GNUNET_FS_DIRECTORY_EXT);
 613         }
 614       else
 615         {
 616           GNUNET_asprintf (&full_name,
 617                            "%s%s%s",
 618                            dn,
 619                            DIR_SEPARATOR_STR,
 620                            filename);
 621         }
 622       GNUNET_free (dn);
 623     }
 624   if ( (full_name != NULL) &&
 625        (GNUNET_OK !=
 626         GNUNET_DISK_directory_create_for_file (full_name)) )
 627     {
 628       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 629                   _("Failed to create directory for recursive download of `%s'\n"),
 630                   full_name);
 631       GNUNET_free (full_name);
 632       GNUNET_free_non_null (fn);
 633       return;
 634     }
 635
 636   if (data != NULL)
 637     {
 638       if (full_name != NULL)
 639         {
 640           fh = GNUNET_DISK_file_open (full_name,
 641                                       GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_TRUNCATE | GNUNET_DISK_OPEN_CREATE,
 642                                       GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE);
 643           if (fh == NULL)
 644             {
 645               GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
 646                                         "open",
 647                                         full_name);
 648               GNUNET_free (full_name);
 649               GNUNET_free_non_null (fn);
 650               return;
 651             }
 652           if (length !=
 653               GNUNET_DISK_file_write (fh,
 654                                       data,
 655                                       length))
 656             {
 657               GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
 658                                         "write",
 659                                         full_name);
 660             }
 661           GNUNET_DISK_file_close (fh);
 662         }
 663       else
 664         {
 665           /* FIXME: generate 'progress' events and move to
 666              instant completion! */
 667           GNUNET_break (0); // FIXME: not implemented
 668         }
 669     }
 670   GNUNET_FS_download_start (dc->h,
 671                             uri,
 672                             meta,
 673                             full_name,
 674                             0,
 675                             GNUNET_FS_uri_chk_get_file_size (uri),
 676                             dc->anonymity,
 677                             dc->options,
 678                             NULL,
 679                             dc);
 680   GNUNET_free_non_null (full_name);
 681   GNUNET_free_non_null (fn);
 682 }
 683
 684
 685 /**
 686  * We're done downloading a directory.  Open the file and
 687  * trigger all of the (remaining) child downloads.
 688  *
 689  * @param dc context of download that just completed
 690  */
 691 static void
 692 full_recursive_download (struct GNUNET_FS_DownloadContext *dc)
 693 {
 694   size_t size;
 695   uint64_t size64;
 696   void *data;
 697   struct GNUNET_DISK_FileHandle *h;
 698   struct GNUNET_DISK_MapHandle *m;
 699
 700   size64 = GNUNET_FS_uri_chk_get_file_size (dc->uri);
 701   size = (size_t) size64;
 702   if (size64 != (uint64_t) size)
 703     {
 704       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 705                   _("Recursive downloads of directories larger than 4 GB are not supported on 32-bit systems\n"));
 706       return;
 707     }
 708   if (dc->filename != NULL)
 709     {
 710       h = GNUNET_DISK_file_open (dc->filename,
 711                                  GNUNET_DISK_OPEN_READ,
 712                                  GNUNET_DISK_PERM_NONE);
 713     }
 714   else
 715     {
 716       GNUNET_assert (dc->temp_filename != NULL);
 717       h = GNUNET_DISK_file_open (dc->temp_filename,
 718                                  GNUNET_DISK_OPEN_READ,
 719                                  GNUNET_DISK_PERM_NONE);
 720     }
 721   if (h == NULL)
 722     return; /* oops */
 723   data = GNUNET_DISK_file_map (h, &m, GNUNET_DISK_MAP_TYPE_READ, size);
 724   if (data == NULL)
 725     {
 726       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 727                   _("Directory too large for system address space\n"));
 728     }
 729   else
 730     {
 731       GNUNET_FS_directory_list_contents (size,
 732                                          data,
 733                                          0,
 734                                          &trigger_recursive_download,
 735                                          dc);
 736       GNUNET_DISK_file_unmap (m);
 737     }
 738   GNUNET_DISK_file_close (h);
 739   if (dc->filename == NULL)
 740     {
 741       if (0 != UNLINK (dc->temp_filename))
 742         GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
 743                                   "unlink",
 744                                   dc->temp_filename);
 745       GNUNET_free (dc->temp_filename);
 746       dc->temp_filename = NULL;
 747     }
 748 }
 749
 750
 751 /**
 752  * Check if all child-downloads have completed and
 753  * if so, signal completion (and possibly recurse to
 754  * parent).
 755  */
 756 static void
 757 check_completed (struct GNUNET_FS_DownloadContext *dc)
 758 {
 759   struct GNUNET_FS_ProgressInfo pi;
 760   struct GNUNET_FS_DownloadContext *pos;
 761
 762   pos = dc->child_head;
 763   while (pos != NULL)
 764     {
 765       if ( (pos->emsg == NULL) &&
 766            (pos->completed < pos->length) )
 767         return; /* not done yet */
 768       if ( (pos->child_head != NULL) &&
 769            (pos->has_finished != GNUNET_YES) )
 770         return; /* not transitively done yet */
 771       pos = pos->next;
 772     }
 773   dc->has_finished = GNUNET_YES;
 774   /* signal completion */
 775   pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
 776   make_download_status (&pi, dc);
 777   dc->client_info = dc->h->upcb (dc->h->upcb_cls,
 778                                  &pi);
 779   if (dc->parent != NULL)
 780     check_completed (dc->parent);
 781 }
 782
 783
 784 /**
 785  * Iterator over entries in the pending requests in the 'active' map for the
 786  * reply that we just got.
 787  *
 788  * @param cls closure (our 'struct ProcessResultClosure')
 789  * @param key query for the given value / request
 790  * @param value value in the hash map (a 'struct DownloadRequest')
 791  * @return GNUNET_YES (we should continue to iterate); unless serious error
 792  */
 793 static int
 794 process_result_with_request (void *cls,
 795                              const GNUNET_HashCode * key,
 796                              void *value)
 797 {
 798   struct ProcessResultClosure *prc = cls;
 799   struct DownloadRequest *sm = value;
 800   struct GNUNET_FS_DownloadContext *dc = prc->dc;
 801   struct GNUNET_CRYPTO_AesSessionKey skey;
 802   struct GNUNET_CRYPTO_AesInitializationVector iv;
 803   char pt[prc->size];
 804   struct GNUNET_FS_ProgressInfo pi;
 805   uint64_t off;
 806   size_t bs;
 807   size_t app;
 808   int i;
 809   struct ContentHashKey *chk;
 810   char *emsg;
 811
 812   bs = GNUNET_FS_tree_calculate_block_size (GNUNET_ntohll (dc->uri->data.chk.file_length),
 813                                             dc->treedepth,
 814                                             sm->offset,
 815                                             sm->depth);
 816     if (prc->size != bs)
 817     {
 818 #if DEBUG_DOWNLOAD
 819       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 820                   "Internal error or bogus download URI (expected %u bytes, got %u)\n",
 821                   bs,
 822                   prc->size);
 823 #endif
 824       dc->emsg = GNUNET_strdup ("Internal error or bogus download URI");
 825       /* signal error */
 826       pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
 827       make_download_status (&pi, dc);
 828       pi.value.download.specifics.error.message = dc->emsg;
 829       dc->client_info = dc->h->upcb (dc->h->upcb_cls,
 830                                      &pi);
 831       /* abort all pending requests */
 832       if (NULL != dc->th)
 833         {
 834           GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
 835           dc->th = NULL;
 836         }
 837       GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
 838       dc->client = NULL;
 839       return GNUNET_NO;
 840     }
 841   GNUNET_assert (GNUNET_YES ==
 842                  GNUNET_CONTAINER_multihashmap_remove (dc->active,
 843                                                        &prc->query,
 844                                                        sm));
 845   GNUNET_CRYPTO_hash_to_aes_key (&sm->chk.key, &skey, &iv);
 846   GNUNET_CRYPTO_aes_decrypt (prc->data,
 847                              prc->size,
 848                              &skey,
 849                              &iv,
 850                              pt);
 851   off = compute_disk_offset (GNUNET_ntohll (dc->uri->data.chk.file_length),
 852                              sm->offset,
 853                              sm->depth,
 854                              dc->treedepth);
 855   /* save to disk */
 856   if ( ( GNUNET_YES == prc->do_store) &&
 857        (NULL != dc->handle) &&
 858        ( (sm->depth == dc->treedepth) ||
 859          (0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES)) ) )
 860     {
 861       emsg = NULL;
 862 #if DEBUG_DOWNLOAD
 863       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 864                   "Saving decrypted block to disk at offset %llu\n",
 865                   (unsigned long long) off);
 866 #endif
 867       if ( (off  !=
 868             GNUNET_DISK_file_seek (dc->handle,
 869                                    off,
 870                                    GNUNET_DISK_SEEK_SET) ) )
 871         GNUNET_asprintf (&emsg,
 872                          _("Failed to seek to offset %llu in file `%s': %s\n"),
 873                          (unsigned long long) off,
 874                          dc->filename,
 875                          STRERROR (errno));
 876       else if (prc->size !=
 877                GNUNET_DISK_file_write (dc->handle,
 878                                        pt,
 879                                        prc->size))
 880         GNUNET_asprintf (&emsg,
 881                          _("Failed to write block of %u bytes at offset %llu in file `%s': %s\n"),
 882                          (unsigned int) prc->size,
 883                          (unsigned long long) off,
 884                          dc->filename,
 885                          STRERROR (errno));
 886       if (NULL != emsg)
 887         {
 888           dc->emsg = emsg;
 889           // FIXME: make persistent
 890
 891           /* signal error */
 892           pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
 893           make_download_status (&pi, dc);
 894           pi.value.download.specifics.error.message = emsg;
 895           dc->client_info = dc->h->upcb (dc->h->upcb_cls,
 896                                          &pi);
 897
 898           /* abort all pending requests */
 899           if (NULL != dc->th)
 900             {
 901               GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
 902               dc->th = NULL;
 903             }
 904           GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
 905           dc->client = NULL;
 906           GNUNET_free (sm);
 907           return GNUNET_NO;
 908         }
 909     }
 910   if (sm->depth == dc->treedepth)
 911     {
 912       app = prc->size;
 913       if (sm->offset < dc->offset)
 914         {
 915           /* starting offset begins in the middle of pt,
 916              do not count first bytes as progress */
 917           GNUNET_assert (app > (dc->offset - sm->offset));
 918           app -= (dc->offset - sm->offset);
 919         }
 920       if (sm->offset + prc->size > dc->offset + dc->length)
 921         {
 922           /* end of block is after relevant range,
 923              do not count last bytes as progress */
 924           GNUNET_assert (app > (sm->offset + prc->size) - (dc->offset + dc->length));
 925           app -= (sm->offset + prc->size) - (dc->offset + dc->length);
 926         }
 927       dc->completed += app;
 928
 929       /* do recursive download if option is set and either meta data
 930          says it is a directory or if no meta data is given AND filename
 931          ends in '.gnd' (top-level case) */
 932       if (is_recursive_download (dc))
 933         GNUNET_FS_directory_list_contents (prc->size,
 934                                            pt,
 935                                            off,
 936                                            &trigger_recursive_download,
 937                                            dc);
 938
 939     }
 940   pi.status = GNUNET_FS_STATUS_DOWNLOAD_PROGRESS;
 941   make_download_status (&pi, dc);
 942   pi.value.download.specifics.progress.data = pt;
 943   pi.value.download.specifics.progress.offset = sm->offset;
 944   pi.value.download.specifics.progress.data_len = prc->size;
 945   pi.value.download.specifics.progress.depth = sm->depth;
 946   dc->client_info = dc->h->upcb (dc->h->upcb_cls,
 947                                  &pi);
 948   GNUNET_assert (dc->completed <= dc->length);
 949   if (dc->completed == dc->length)
 950     {
 951 #if DEBUG_DOWNLOAD
 952       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 953                   "Download completed, truncating file to desired length %llu\n",
 954                   (unsigned long long) GNUNET_ntohll (dc->uri->data.chk.file_length));
 955 #endif
 956       /* truncate file to size (since we store IBlocks at the end) */
 957       if (dc->handle != NULL)
 958         {
 959           GNUNET_DISK_file_close (dc->handle);
 960           dc->handle = NULL;
 961           if (0 != truncate (dc->filename,
 962                              GNUNET_ntohll (dc->uri->data.chk.file_length)))
 963             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
 964                                       "truncate",
 965                                       dc->filename);
 966         }
 967
 968       if (is_recursive_download (dc))
 969         full_recursive_download (dc);
 970       if (dc->child_head == NULL)
 971         {
 972           /* signal completion */
 973           pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
 974           make_download_status (&pi, dc);
 975           dc->client_info = dc->h->upcb (dc->h->upcb_cls,
 976                                          &pi);
 977           if (dc->parent != NULL)
 978             check_completed (dc->parent);
 979         }
 980       GNUNET_assert (sm->depth == dc->treedepth);
 981     }
 982   // FIXME: make persistent
 983   if (sm->depth == dc->treedepth)
 984     {
 985       GNUNET_free (sm);
 986       return GNUNET_YES;
 987     }
 988 #if DEBUG_DOWNLOAD
 989   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 990               "Triggering downloads of children (this block was at depth %u and offset %llu)\n",
 991               sm->depth,
 992               (unsigned long long) sm->offset);
 993 #endif
 994   GNUNET_assert (0 == (prc->size % sizeof(struct ContentHashKey)));
 995   chk = (struct ContentHashKey*) pt;
 996   for (i=(prc->size / sizeof(struct ContentHashKey))-1;i>=0;i--)
 997     {
 998       off = compute_dblock_offset (sm->offset,
 999                                    sm->depth,
1000                                    dc->treedepth,
1001                                    i);
1002       if ( (off + DBLOCK_SIZE >= dc->offset) &&
1003            (off < dc->offset + dc->length) )
1004         schedule_block_download (dc,
1005                                  &chk[i],
1006                                  off,
1007                                  sm->depth + 1);
1008     }
1009   GNUNET_free (sm);
1010   return GNUNET_YES;
1011 }
1012
1013
1014 /**
1015  * Process a download result.
1016  *
1017  * @param dc our download context
1018  * @param type type of the result
1019  * @param data the (encrypted) response
1020  * @param size size of data
1021  */
1022 static void
1023 process_result (struct GNUNET_FS_DownloadContext *dc,
1024                 uint32_t type,
1025                 const void *data,
1026                 size_t size)
1027 {
1028   struct ProcessResultClosure prc;
1029
1030   prc.dc = dc;
1031   prc.data = data;
1032   prc.size = size;
1033   prc.type = type;
1034   prc.do_store = GNUNET_YES;
1035   GNUNET_CRYPTO_hash (data, size, &prc.query);
1036 #if DEBUG_DOWNLOAD
1037   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1038               "Received result for query `%s' from `%s'-service\n",
1039               GNUNET_h2s (&prc.query),
1040               "FS");
1041 #endif
1042   GNUNET_CONTAINER_multihashmap_get_multiple (dc->active,
1043                                               &prc.query,
1044                                               &process_result_with_request,
1045                                               &prc);
1046 }
1047
1048
1049 /**
1050  * Type of a function to call when we receive a message
1051  * from the service.
1052  *
1053  * @param cls closure
1054  * @param msg message received, NULL on timeout or fatal error
1055  */
1056 static void
1057 receive_results (void *cls,
1058                  const struct GNUNET_MessageHeader * msg)
1059 {
1060   struct GNUNET_FS_DownloadContext *dc = cls;
1061   const struct PutMessage *cm;
1062   uint16_t msize;
1063
1064   if ( (NULL == msg) ||
1065        (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_FS_PUT) ||
1066        (sizeof (struct PutMessage) > ntohs(msg->size)) )
1067     {
1068       GNUNET_break (msg == NULL);
1069       try_reconnect (dc);
1070       return;
1071     }
1072   msize = ntohs(msg->size);
1073   cm = (const struct PutMessage*) msg;
1074   process_result (dc,
1075                   ntohl (cm->type),
1076                   &cm[1],
1077                   msize - sizeof (struct PutMessage));
1078   if (dc->client == NULL)
1079     return; /* fatal error */
1080   /* continue receiving */
1081   GNUNET_CLIENT_receive (dc->client,
1082                          &receive_results,
1083                          dc,
1084                          GNUNET_TIME_UNIT_FOREVER_REL);
1085 }
1086
1087
1088
1089 /**
1090  * We're ready to transmit a search request to the
1091  * file-sharing service.  Do it.  If there is
1092  * more than one request pending, try to send
1093  * multiple or request another transmission.
1094  *
1095  * @param cls closure
1096  * @param size number of bytes available in buf
1097  * @param buf where the callee should write the message
1098  * @return number of bytes written to buf
1099  */
1100 static size_t
1101 transmit_download_request (void *cls,
1102                            size_t size,
1103                            void *buf)
1104 {
1105   struct GNUNET_FS_DownloadContext *dc = cls;
1106   size_t msize;
1107   struct SearchMessage *sm;
1108
1109   dc->th = NULL;
1110   if (NULL == buf)
1111     {
1112       try_reconnect (dc);
1113       return 0;
1114     }
1115   GNUNET_assert (size >= sizeof (struct SearchMessage));
1116   msize = 0;
1117   sm = buf;
1118   while ( (dc->pending != NULL) &&
1119           (size > msize + sizeof (struct SearchMessage)) )
1120     {
1121 #if DEBUG_DOWNLOAD
1122       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1123                   "Transmitting download request for `%s' to `%s'-service\n",
1124                   GNUNET_h2s (&dc->pending->chk.query),
1125                   "FS");
1126 #endif
1127       memset (sm, 0, sizeof (struct SearchMessage));
1128       sm->header.size = htons (sizeof (struct SearchMessage));
1129       sm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_START_SEARCH);
1130       if (dc->pending->depth == dc->treedepth)
1131         sm->type = htonl (GNUNET_DATASTORE_BLOCKTYPE_DBLOCK);
1132       else
1133         sm->type = htonl (GNUNET_DATASTORE_BLOCKTYPE_IBLOCK);
1134       sm->anonymity_level = htonl (dc->anonymity);
1135       sm->target = dc->target.hashPubKey;
1136       sm->query = dc->pending->chk.query;
1137       dc->pending->is_pending = GNUNET_NO;
1138       dc->pending = dc->pending->next;
1139       msize += sizeof (struct SearchMessage);
1140       sm++;
1141     }
1142   if (dc->pending != NULL)
1143     dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
1144                                                   sizeof (struct SearchMessage),
1145                                                   GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1146                                                   GNUNET_NO,
1147                                                   &transmit_download_request,
1148                                                   dc);
1149   return msize;
1150 }
1151
1152
1153 /**
1154  * Reconnect to the FS service and transmit our queries NOW.
1155  *
1156  * @param cls our download context
1157  * @param tc unused
1158  */
1159 static void
1160 do_reconnect (void *cls,
1161               const struct GNUNET_SCHEDULER_TaskContext *tc)
1162 {
1163   struct GNUNET_FS_DownloadContext *dc = cls;
1164   struct GNUNET_CLIENT_Connection *client;
1165
1166   dc->task = GNUNET_SCHEDULER_NO_TASK;
1167   client = GNUNET_CLIENT_connect (dc->h->sched,
1168                                   "fs",
1169                                   dc->h->cfg);
1170   if (NULL == client)
1171     {
1172       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1173                   "Connecting to `%s'-service failed, will try again.\n",
1174                   "FS");
1175       try_reconnect (dc);
1176       return;
1177     }
1178   dc->client = client;
1179   dc->th = GNUNET_CLIENT_notify_transmit_ready (client,
1180                                                 sizeof (struct SearchMessage),
1181                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1182                                                 GNUNET_NO,
1183                                                 &transmit_download_request,
1184                                                 dc);
1185   GNUNET_CLIENT_receive (client,
1186                          &receive_results,
1187                          dc,
1188                          GNUNET_TIME_UNIT_FOREVER_REL);
1189 }
1190
1191
1192 /**
1193  * Add entries that are not yet pending back to the pending list.
1194  *
1195  * @param cls our download context
1196  * @param key unused
1197  * @param entry entry of type "struct DownloadRequest"
1198  * @return GNUNET_OK
1199  */
1200 static int
1201 retry_entry (void *cls,
1202              const GNUNET_HashCode *key,
1203              void *entry)
1204 {
1205   struct GNUNET_FS_DownloadContext *dc = cls;
1206   struct DownloadRequest *dr = entry;
1207
1208   if (! dr->is_pending)
1209     {
1210       dr->next = dc->pending;
1211       dr->is_pending = GNUNET_YES;
1212       dc->pending = entry;
1213     }
1214   return GNUNET_OK;
1215 }
1216
1217
1218 /**
1219  * We've lost our connection with the FS service.
1220  * Re-establish it and re-transmit all of our
1221  * pending requests.
1222  *
1223  * @param dc download context that is having trouble
1224  */
1225 static void
1226 try_reconnect (struct GNUNET_FS_DownloadContext *dc)
1227 {
1228
1229   if (NULL != dc->client)
1230     {
1231       if (NULL != dc->th)
1232         {
1233           GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1234           dc->th = NULL;
1235         }
1236       GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1237                                              &retry_entry,
1238                                              dc);
1239       GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1240       dc->client = NULL;
1241     }
1242   dc->task
1243     = GNUNET_SCHEDULER_add_delayed (dc->h->sched,
1244                                     GNUNET_TIME_UNIT_SECONDS,
1245                                     &do_reconnect,
1246                                     dc);
1247 }
1248
1249
1250 /**
1251  * Download parts of a file.  Note that this will store
1252  * the blocks at the respective offset in the given file.  Also, the
1253  * download is still using the blocking of the underlying FS
1254  * encoding.  As a result, the download may *write* outside of the
1255  * given boundaries (if offset and length do not match the 32k FS
1256  * block boundaries). <p>
1257  *
1258  * This function should be used to focus a download towards a
1259  * particular portion of the file (optimization), not to strictly
1260  * limit the download to exactly those bytes.
1261  *
1262  * @param h handle to the file sharing subsystem
1263  * @param uri the URI of the file (determines what to download); CHK or LOC URI
1264  * @param meta known metadata for the file (can be NULL)
1265  * @param filename where to store the file, maybe NULL (then no file is
1266  *        created on disk and data must be grabbed from the callbacks)
1267  * @param offset at what offset should we start the download (typically 0)
1268  * @param length how many bytes should be downloaded starting at offset
1269  * @param anonymity anonymity level to use for the download
1270  * @param options various options
1271  * @param cctx initial value for the client context for this download
1272  * @param parent parent download to associate this download with (use NULL
1273  *        for top-level downloads; useful for manually-triggered recursive downloads)
1274  * @return context that can be used to control this download
1275  */
1276 struct GNUNET_FS_DownloadContext *
1277 GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
1278                           const struct GNUNET_FS_Uri *uri,
1279                           const struct GNUNET_CONTAINER_MetaData *meta,
1280                           const char *filename,
1281                           uint64_t offset,
1282                           uint64_t length,
1283                           uint32_t anonymity,
1284                           enum GNUNET_FS_DownloadOptions options,
1285                           void *cctx,
1286                           struct GNUNET_FS_DownloadContext *parent)
1287 {
1288   struct GNUNET_FS_ProgressInfo pi;
1289   struct GNUNET_FS_DownloadContext *dc;
1290   struct GNUNET_CLIENT_Connection *client;
1291
1292   GNUNET_assert (GNUNET_FS_uri_test_chk (uri));
1293   if ( (offset + length < offset) ||
1294        (offset + length > uri->data.chk.file_length) )
1295     {
1296       GNUNET_break (0);
1297       return NULL;
1298     }
1299   // FIXME: add support for "loc" URIs!
1300 #if DEBUG_DOWNLOAD
1301   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1302               "Starting download `%s' of %llu bytes\n",
1303               filename,
1304               (unsigned long long) length);
1305 #endif
1306   dc = GNUNET_malloc (sizeof(struct GNUNET_FS_DownloadContext));
1307   dc->h = h;
1308   dc->parent = parent;
1309   if (parent != NULL)
1310     {
1311       GNUNET_CONTAINER_DLL_insert (parent->child_head,
1312                                    parent->child_tail,
1313                                    dc);
1314     }
1315   dc->uri = GNUNET_FS_uri_dup (uri);
1316   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (meta);
1317   dc->client_info = cctx;
1318   dc->start_time = GNUNET_TIME_absolute_get ();
1319   if (NULL != filename)
1320     {
1321       dc->filename = GNUNET_strdup (filename);
1322       if (GNUNET_YES == GNUNET_DISK_file_test (filename))
1323         GNUNET_DISK_file_size (filename,
1324                                &dc->old_file_size,
1325                                GNUNET_YES);
1326       dc->handle = GNUNET_DISK_file_open (filename,
1327                                           GNUNET_DISK_OPEN_READWRITE |
1328                                           GNUNET_DISK_OPEN_CREATE,
1329                                           GNUNET_DISK_PERM_USER_READ |
1330                                           GNUNET_DISK_PERM_USER_WRITE |
1331                                           GNUNET_DISK_PERM_GROUP_READ |
1332                                           GNUNET_DISK_PERM_OTHER_READ);
1333       if (dc->handle == NULL)
1334         {
1335           GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1336                       _("Download failed: could not open file `%s': %s\n"),
1337                       dc->filename,
1338                       STRERROR (errno));
1339           GNUNET_CONTAINER_meta_data_destroy (dc->meta);
1340           GNUNET_FS_uri_destroy (dc->uri);
1341           GNUNET_free (dc->filename);
1342           GNUNET_free (dc);
1343           return NULL;
1344         }
1345     }
1346   // FIXME: set "dc->target" for LOC uris!
1347   dc->offset = offset;
1348   dc->length = length;
1349   dc->anonymity = anonymity;
1350   dc->options = options;
1351   dc->active = GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
1352   dc->treedepth = GNUNET_FS_compute_depth (GNUNET_ntohll(dc->uri->data.chk.file_length));
1353   if ( (filename == NULL) &&
1354        (is_recursive_download (dc) ) )
1355     dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
1356
1357 #if DEBUG_DOWNLOAD
1358   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1359               "Download tree has depth %u\n",
1360               dc->treedepth);
1361 #endif
1362   // FIXME: make persistent
1363
1364   // FIXME: bound parallelism here!
1365   client = GNUNET_CLIENT_connect (h->sched,
1366                                   "fs",
1367                                   h->cfg);
1368   dc->client = client;
1369   schedule_block_download (dc,
1370                            &dc->uri->data.chk.chk,
1371                            0,
1372                            1 /* 0 == CHK, 1 == top */);
1373   GNUNET_CLIENT_receive (client,
1374                          &receive_results,
1375                          dc,
1376                          GNUNET_TIME_UNIT_FOREVER_REL);
1377   pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
1378   make_download_status (&pi, dc);
1379   pi.value.download.specifics.start.meta = meta;
1380   dc->client_info = dc->h->upcb (dc->h->upcb_cls,
1381                                  &pi);
1382
1383   return dc;
1384 }
1385
1386
1387 /**
1388  * Free entries in the map.
1389  *
1390  * @param cls unused (NULL)
1391  * @param key unused
1392  * @param entry entry of type "struct DownloadRequest" which is freed
1393  * @return GNUNET_OK
1394  */
1395 static int
1396 free_entry (void *cls,
1397             const GNUNET_HashCode *key,
1398             void *entry)
1399 {
1400   GNUNET_free (entry);
1401   return GNUNET_OK;
1402 }
1403
1404
1405 /**
1406  * Stop a download (aborts if download is incomplete).
1407  *
1408  * @param dc handle for the download
1409  * @param do_delete delete files of incomplete downloads
1410  */
1411 void
1412 GNUNET_FS_download_stop (struct GNUNET_FS_DownloadContext *dc,
1413                          int do_delete)
1414 {
1415   struct GNUNET_FS_ProgressInfo pi;
1416
1417   while (NULL != dc->child_head)
1418     GNUNET_FS_download_stop (dc->child_head,
1419                              do_delete);
1420   // FIXME: make unpersistent
1421   if (dc->parent != NULL)
1422     GNUNET_CONTAINER_DLL_remove (dc->parent->child_head,
1423                                  dc->parent->child_tail,
1424                                  dc);
1425
1426   pi.status = GNUNET_FS_STATUS_DOWNLOAD_STOPPED;
1427   make_download_status (&pi, dc);
1428   dc->client_info = dc->h->upcb (dc->h->upcb_cls,
1429                                  &pi);
1430
1431   if (GNUNET_SCHEDULER_NO_TASK != dc->task)
1432     GNUNET_SCHEDULER_cancel (dc->h->sched,
1433                              dc->task);
1434   if (NULL != dc->th)
1435     {
1436       GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1437       dc->th = NULL;
1438     }
1439   if (NULL != dc->client)
1440     GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1441   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1442                                          &free_entry,
1443                                          NULL);
1444   GNUNET_CONTAINER_multihashmap_destroy (dc->active);
1445   if (dc->filename != NULL)
1446     {
1447       if (NULL != dc->handle)
1448         GNUNET_DISK_file_close (dc->handle);
1449       if ( (dc->completed != dc->length) &&
1450            (GNUNET_YES == do_delete) )
1451         {
1452           if (0 != UNLINK (dc->filename))
1453             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
1454                                       "unlink",
1455                                       dc->filename);
1456         }
1457       GNUNET_free (dc->filename);
1458     }
1459   GNUNET_CONTAINER_meta_data_destroy (dc->meta);
1460   GNUNET_FS_uri_destroy (dc->uri);
1461   if (NULL != dc->temp_filename)
1462     {
1463       if (0 != UNLINK (dc->temp_filename))
1464         GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
1465                                   "unlink",
1466                                   dc->temp_filename);
1467       GNUNET_free (dc->temp_filename);
1468     }
1469   GNUNET_free (dc);
1470 }
1471
1472 /* end of fs_download.c */