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  * - location URI suppport (can wait, easy)
  27  * - different priority for scheduling probe downloads?
  28  * - check if iblocks can be computed from existing blocks (can wait, hard)
  29  */
  30 #include "platform.h"
  31 #include "gnunet_constants.h"
  32 #include "gnunet_fs_service.h"
  33 #include "fs.h"
  34 #include "fs_tree.h"
  35
  36 #define DEBUG_DOWNLOAD GNUNET_YES
  37
  38 /**
  39  * Determine if the given download (options and meta data) should cause
  40  * use to try to do a recursive download.
  41  */
  42 static int
  43 is_recursive_download (struct GNUNET_FS_DownloadContext *dc)
  44 {
  45   return  (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_RECURSIVE)) &&
  46     ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (dc->meta)) ||
  47       ( (dc->meta == NULL) &&
  48         ( (NULL == dc->filename) ||
  49           ( (strlen (dc->filename) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
  50             (NULL !=
  51              strstr (dc->filename + strlen(dc->filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
  52                      GNUNET_FS_DIRECTORY_EXT)) ) ) ) );
  53 }
  54
  55
  56 /**
  57  * We're storing the IBLOCKS after the DBLOCKS on disk (so that we
  58  * only have to truncate the file once we're done).
  59  *
  60  * Given the offset of a block (with respect to the DBLOCKS) and its
  61  * depth, return the offset where we would store this block in the
  62  * file.
  63  *
  64  * @param fsize overall file size
  65  * @param off offset of the block in the file
  66  * @param depth depth of the block in the tree
  67  * @param treedepth maximum depth of the tree
  68  * @return off for DBLOCKS (depth == treedepth),
  69  *         otherwise an offset past the end
  70  *         of the file that does not overlap
  71  *         with the range for any other block
  72  */
  73 static uint64_t
  74 compute_disk_offset (uint64_t fsize,
  75                      uint64_t off,
  76                      unsigned int depth,
  77                      unsigned int treedepth)
  78 {
  79   unsigned int i;
  80   uint64_t lsize; /* what is the size of all IBlocks for depth "i"? */
  81   uint64_t loff; /* where do IBlocks for depth "i" start? */
  82   unsigned int ioff; /* which IBlock corresponds to "off" at depth "i"? */
  83
  84   if (depth == treedepth)
  85     return off;
  86   /* first IBlocks start at the end of file, rounded up
  87      to full DBLOCK_SIZE */
  88   loff = ((fsize + DBLOCK_SIZE - 1) / DBLOCK_SIZE) * DBLOCK_SIZE;
  89   lsize = ( (fsize + DBLOCK_SIZE-1) / DBLOCK_SIZE) * sizeof (struct ContentHashKey);
  90   GNUNET_assert (0 == (off % DBLOCK_SIZE));
  91   ioff = (off / DBLOCK_SIZE);
  92   for (i=treedepth-1;i>depth;i--)
  93     {
  94       loff += lsize;
  95       lsize = (lsize + CHK_PER_INODE - 1) / CHK_PER_INODE;
  96       GNUNET_assert (lsize > 0);
  97       GNUNET_assert (0 == (ioff % CHK_PER_INODE));
  98       ioff /= CHK_PER_INODE;
  99     }
 100   return loff + ioff * sizeof (struct ContentHashKey);
 101 }
 102
 103
 104 /**
 105  * Given a file of the specified treedepth and a block at the given
 106  * offset and depth, calculate the offset for the CHK at the given
 107  * index.
 108  *
 109  * @param offset the offset of the first
 110  *        DBLOCK in the subtree of the
 111  *        identified IBLOCK
 112  * @param depth the depth of the IBLOCK in the tree
 113  * @param treedepth overall depth of the tree
 114  * @param k which CHK in the IBLOCK are we
 115  *        talking about
 116  * @return offset if k=0, otherwise an appropriately
 117  *         larger value (i.e., if depth = treedepth-1,
 118  *         the returned value should be offset+DBLOCK_SIZE)
 119  */
 120 static uint64_t
 121 compute_dblock_offset (uint64_t offset,
 122                        unsigned int depth,
 123                        unsigned int treedepth,
 124                        unsigned int k)
 125 {
 126   unsigned int i;
 127   uint64_t lsize; /* what is the size of the sum of all DBlocks
 128                      that a CHK at depth i corresponds to? */
 129
 130   if (depth == treedepth)
 131     return offset;
 132   lsize = DBLOCK_SIZE;
 133   for (i=treedepth-1;i>depth;i--)
 134     lsize *= CHK_PER_INODE;
 135   return offset + k * lsize;
 136 }
 137
 138
 139 /**
 140  * Fill in all of the generic fields for a download event and call the
 141  * callback.
 142  *
 143  * @param pi structure to fill in
 144  * @param dc overall download context
 145  */
 146 void
 147 GNUNET_FS_download_make_status_ (struct GNUNET_FS_ProgressInfo *pi,
 148                                  struct GNUNET_FS_DownloadContext *dc)
 149 {
 150   pi->value.download.dc = dc;
 151   pi->value.download.cctx
 152     = dc->client_info;
 153   pi->value.download.pctx
 154     = (dc->parent == NULL) ? NULL : dc->parent->client_info;
 155   pi->value.download.sctx
 156     = (dc->search == NULL) ? NULL : dc->search->client_info;
 157   pi->value.download.uri
 158     = dc->uri;
 159   pi->value.download.filename
 160     = dc->filename;
 161   pi->value.download.size
 162     = dc->length;
 163   pi->value.download.duration
 164     = GNUNET_TIME_absolute_get_duration (dc->start_time);
 165   pi->value.download.completed
 166     = dc->completed;
 167   pi->value.download.anonymity
 168     = dc->anonymity;
 169   pi->value.download.eta
 170     = GNUNET_TIME_calculate_eta (dc->start_time,
 171                                  dc->completed,
 172                                  dc->length);
 173   if (0 == (dc->options & GNUNET_FS_DOWNLOAD_IS_PROBE))
 174     dc->client_info = dc->h->upcb (dc->h->upcb_cls,
 175                                    pi);
 176   else
 177     dc->client_info = GNUNET_FS_search_probe_progress_ (NULL,
 178                                                         pi);
 179 }
 180
 181 /**
 182  * We're ready to transmit a search request to the
 183  * file-sharing service.  Do it.  If there is
 184  * more than one request pending, try to send
 185  * multiple or request another transmission.
 186  *
 187  * @param cls closure
 188  * @param size number of bytes available in buf
 189  * @param buf where the callee should write the message
 190  * @return number of bytes written to buf
 191  */
 192 static size_t
 193 transmit_download_request (void *cls,
 194                            size_t size,
 195                            void *buf);
 196
 197
 198 /**
 199  * Closure for iterator processing results.
 200  */
 201 struct ProcessResultClosure
 202 {
 203
 204   /**
 205    * Hash of data.
 206    */
 207   GNUNET_HashCode query;
 208
 209   /**
 210    * Data found in P2P network.
 211    */
 212   const void *data;
 213
 214   /**
 215    * Our download context.
 216    */
 217   struct GNUNET_FS_DownloadContext *dc;
 218
 219   /**
 220    * Number of bytes in data.
 221    */
 222   size_t size;
 223
 224   /**
 225    * Type of data.
 226    */
 227   enum GNUNET_BLOCK_Type type;
 228
 229   /**
 230    * Flag to indicate if this block should be stored on disk.
 231    */
 232   int do_store;
 233
 234 };
 235
 236
 237 /**
 238  * Iterator over entries in the pending requests in the 'active' map for the
 239  * reply that we just got.
 240  *
 241  * @param cls closure (our 'struct ProcessResultClosure')
 242  * @param key query for the given value / request
 243  * @param value value in the hash map (a 'struct DownloadRequest')
 244  * @return GNUNET_YES (we should continue to iterate); unless serious error
 245  */
 246 static int
 247 process_result_with_request (void *cls,
 248                              const GNUNET_HashCode * key,
 249                              void *value);
 250
 251
 252
 253 /**
 254  * Schedule the download of the specified block in the tree.
 255  *
 256  * @param dc overall download this block belongs to
 257  * @param chk content-hash-key of the block
 258  * @param offset offset of the block in the file
 259  *         (for IBlocks, the offset is the lowest
 260  *          offset of any DBlock in the subtree under
 261  *          the IBlock)
 262  * @param depth depth of the block, 0 is the root of the tree
 263  */
 264 static void
 265 schedule_block_download (struct GNUNET_FS_DownloadContext *dc,
 266                          const struct ContentHashKey *chk,
 267                          uint64_t offset,
 268                          unsigned int depth)
 269 {
 270   struct DownloadRequest *sm;
 271   uint64_t total;
 272   uint64_t off;
 273   size_t len;
 274   char block[DBLOCK_SIZE];
 275   GNUNET_HashCode key;
 276   struct ProcessResultClosure prc;
 277   struct GNUNET_DISK_FileHandle *fh;
 278
 279 #if DEBUG_DOWNLOAD
 280   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 281               "Scheduling download at offset %llu and depth %u for `%s'\n",
 282               (unsigned long long) offset,
 283               depth,
 284               GNUNET_h2s (&chk->query));
 285 #endif
 286   total = GNUNET_ntohll (dc->uri->data.chk.file_length);
 287   off = compute_disk_offset (total,
 288                              offset,
 289                              depth,
 290                              dc->treedepth);
 291   len = GNUNET_FS_tree_calculate_block_size (total,
 292                                              dc->treedepth,
 293                                              offset,
 294                                              depth);
 295   sm = GNUNET_malloc (sizeof (struct DownloadRequest));
 296   sm->chk = *chk;
 297   sm->offset = offset;
 298   sm->depth = depth;
 299   sm->is_pending = GNUNET_YES;
 300   sm->next = dc->pending;
 301   dc->pending = sm;
 302   GNUNET_CONTAINER_multihashmap_put (dc->active,
 303                                      &chk->query,
 304                                      sm,
 305                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
 306   fh = NULL;
 307   if ( (dc->old_file_size > off) &&
 308        (dc->filename != NULL) )
 309     fh = GNUNET_DISK_file_open (dc->filename,
 310                                 GNUNET_DISK_OPEN_READ,
 311                                 GNUNET_DISK_PERM_NONE);
 312   if ( (fh != NULL) &&
 313        (off  ==
 314         GNUNET_DISK_file_seek (fh,
 315                                off,
 316                                GNUNET_DISK_SEEK_SET) ) &&
 317        (len ==
 318         GNUNET_DISK_file_read (fh,
 319                                block,
 320                                len)) )
 321     {
 322       GNUNET_CRYPTO_hash (block, len, &key);
 323       if (0 == memcmp (&key,
 324                        &chk->key,
 325                        sizeof (GNUNET_HashCode)))
 326         {
 327           char enc[len];
 328           struct GNUNET_CRYPTO_AesSessionKey sk;
 329           struct GNUNET_CRYPTO_AesInitializationVector iv;
 330           GNUNET_HashCode query;
 331
 332           GNUNET_CRYPTO_hash_to_aes_key (&key, &sk, &iv);
 333           GNUNET_CRYPTO_aes_encrypt (block, len,
 334                                      &sk,
 335                                      &iv,
 336                                      enc);
 337           GNUNET_CRYPTO_hash (enc, len, &query);
 338           if (0 == memcmp (&query,
 339                            &chk->query,
 340                            sizeof (GNUNET_HashCode)))
 341             {
 342               /* already got it! */
 343               prc.dc = dc;
 344               prc.data = enc;
 345               prc.size = len;
 346               prc.type = (dc->treedepth == depth)
 347                 ? GNUNET_BLOCK_TYPE_DBLOCK
 348                 : GNUNET_BLOCK_TYPE_IBLOCK;
 349               prc.query = chk->query;
 350               prc.do_store = GNUNET_NO; /* useless */
 351               process_result_with_request (&prc,
 352                                            &key,
 353                                            sm);
 354             }
 355           else
 356             {
 357               GNUNET_break_op (0);
 358             }
 359           GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
 360           return;
 361         }
 362     }
 363   if (fh != NULL)
 364     GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
 365   if (depth < dc->treedepth)
 366     {
 367       // FIXME: try if we could
 368       // reconstitute this IBLOCK
 369       // from the existing blocks on disk (can wait)
 370       // (read block(s), encode, compare with
 371       // query; if matches, simply return)
 372     }
 373
 374   if ( (dc->th == NULL) &&
 375        (dc->client != NULL) )
 376     dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
 377                                                   sizeof (struct SearchMessage),
 378                                                   GNUNET_CONSTANTS_SERVICE_TIMEOUT,
 379                                                   GNUNET_NO,
 380                                                   &transmit_download_request,
 381                                                   dc);
 382 }
 383
 384
 385
 386 /**
 387  * Suggest a filename based on given metadata.
 388  *
 389  * @param md given meta data
 390  * @return NULL if meta data is useless for suggesting a filename
 391  */
 392 char *
 393 GNUNET_FS_meta_data_suggest_filename (const struct GNUNET_CONTAINER_MetaData *md)
 394 {
 395   static const char *mimeMap[][2] = {
 396     {"application/bz2", ".bz2"},
 397     {"application/gnunet-directory", ".gnd"},
 398     {"application/java", ".class"},
 399     {"application/msword", ".doc"},
 400     {"application/ogg", ".ogg"},
 401     {"application/pdf", ".pdf"},
 402     {"application/pgp-keys", ".key"},
 403     {"application/pgp-signature", ".pgp"},
 404     {"application/postscript", ".ps"},
 405     {"application/rar", ".rar"},
 406     {"application/rtf", ".rtf"},
 407     {"application/xml", ".xml"},
 408     {"application/x-debian-package", ".deb"},
 409     {"application/x-dvi", ".dvi"},
 410     {"applixation/x-flac", ".flac"},
 411     {"applixation/x-gzip", ".gz"},
 412     {"application/x-java-archive", ".jar"},
 413     {"application/x-java-vm", ".class"},
 414     {"application/x-python-code", ".pyc"},
 415     {"application/x-redhat-package-manager", ".rpm"},
 416     {"application/x-rpm", ".rpm"},
 417     {"application/x-tar", ".tar"},
 418     {"application/x-tex-pk", ".pk"},
 419     {"application/x-texinfo", ".texinfo"},
 420     {"application/x-xcf", ".xcf"},
 421     {"application/x-xfig", ".xfig"},
 422     {"application/zip", ".zip"},
 423
 424     {"audio/midi", ".midi"},
 425     {"audio/mpeg", ".mp3"},
 426     {"audio/real", ".rm"},
 427     {"audio/x-wav", ".wav"},
 428
 429     {"image/gif", ".gif"},
 430     {"image/jpeg", ".jpg"},
 431     {"image/pcx", ".pcx"},
 432     {"image/png", ".png"},
 433     {"image/tiff", ".tiff"},
 434     {"image/x-ms-bmp", ".bmp"},
 435     {"image/x-xpixmap", ".xpm"},
 436
 437     {"text/css", ".css"},
 438     {"text/html", ".html"},
 439     {"text/plain", ".txt"},
 440     {"text/rtf", ".rtf"},
 441     {"text/x-c++hdr", ".h++"},
 442     {"text/x-c++src", ".c++"},
 443     {"text/x-chdr", ".h"},
 444     {"text/x-csrc", ".c"},
 445     {"text/x-java", ".java"},
 446     {"text/x-moc", ".moc"},
 447     {"text/x-pascal", ".pas"},
 448     {"text/x-perl", ".pl"},
 449     {"text/x-python", ".py"},
 450     {"text/x-tex", ".tex"},
 451
 452     {"video/avi", ".avi"},
 453     {"video/mpeg", ".mpeg"},
 454     {"video/quicktime", ".qt"},
 455     {"video/real", ".rm"},
 456     {"video/x-msvideo", ".avi"},
 457     {NULL, NULL},
 458   };
 459   char *ret;
 460   unsigned int i;
 461   char *mime;
 462   char *base;
 463   const char *ext;
 464
 465   ret = GNUNET_CONTAINER_meta_data_get_by_type (md,
 466                                                 EXTRACTOR_METATYPE_FILENAME);
 467   if (ret != NULL)
 468     return ret;
 469   ext = NULL;
 470   mime = GNUNET_CONTAINER_meta_data_get_by_type (md,
 471                                                  EXTRACTOR_METATYPE_MIMETYPE);
 472   if (mime != NULL)
 473     {
 474       i = 0;
 475       while ( (mimeMap[i][0] != NULL) &&
 476               (0 != strcmp (mime, mimeMap[i][0])))
 477         i++;
 478       if (mimeMap[i][1] == NULL)
 479         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG |
 480                     GNUNET_ERROR_TYPE_BULK,
 481                     _("Did not find mime type `%s' in extension list.\n"),
 482                     mime);
 483       else
 484         ext = mimeMap[i][1];
 485       GNUNET_free (mime);
 486     }
 487   base = GNUNET_CONTAINER_meta_data_get_first_by_types (md,
 488                                                         EXTRACTOR_METATYPE_TITLE,
 489                                                         EXTRACTOR_METATYPE_BOOK_TITLE,
 490                                                         EXTRACTOR_METATYPE_ORIGINAL_TITLE,
 491                                                         EXTRACTOR_METATYPE_PACKAGE_NAME,
 492                                                         EXTRACTOR_METATYPE_URL,
 493                                                         EXTRACTOR_METATYPE_URI,
 494                                                         EXTRACTOR_METATYPE_DESCRIPTION,
 495                                                         EXTRACTOR_METATYPE_ISRC,
 496                                                         EXTRACTOR_METATYPE_JOURNAL_NAME,
 497                                                         EXTRACTOR_METATYPE_AUTHOR_NAME,
 498                                                         EXTRACTOR_METATYPE_SUBJECT,
 499                                                         EXTRACTOR_METATYPE_ALBUM,
 500                                                         EXTRACTOR_METATYPE_ARTIST,
 501                                                         EXTRACTOR_METATYPE_KEYWORDS,
 502                                                         EXTRACTOR_METATYPE_COMMENT,
 503                                                         EXTRACTOR_METATYPE_UNKNOWN,
 504                                                         -1);
 505   if ( (base == NULL) &&
 506        (ext == NULL) )
 507     return NULL;
 508   if (base == NULL)
 509     return GNUNET_strdup (ext);
 510   if (ext == NULL)
 511     return base;
 512   GNUNET_asprintf (&ret,
 513                    "%s%s",
 514                    base,
 515                    ext);
 516   GNUNET_free (base);
 517   return ret;
 518 }
 519
 520
 521 /**
 522  * We've lost our connection with the FS service.
 523  * Re-establish it and re-transmit all of our
 524  * pending requests.
 525  *
 526  * @param dc download context that is having trouble
 527  */
 528 static void
 529 try_reconnect (struct GNUNET_FS_DownloadContext *dc);
 530
 531
 532 /**
 533  * We found an entry in a directory.  Check if the respective child
 534  * already exists and if not create the respective child download.
 535  *
 536  * @param cls the parent download
 537  * @param filename name of the file in the directory
 538  * @param uri URI of the file (CHK or LOC)
 539  * @param meta meta data of the file
 540  * @param length number of bytes in data
 541  * @param data contents of the file (or NULL if they were not inlined)
 542  */
 543 static void
 544 trigger_recursive_download (void *cls,
 545                             const char *filename,
 546                             const struct GNUNET_FS_Uri *uri,
 547                             const struct GNUNET_CONTAINER_MetaData *meta,
 548                             size_t length,
 549                             const void *data);
 550
 551
 552 /**
 553  * We're done downloading a directory.  Open the file and
 554  * trigger all of the (remaining) child downloads.
 555  *
 556  * @param dc context of download that just completed
 557  */
 558 static void
 559 full_recursive_download (struct GNUNET_FS_DownloadContext *dc)
 560 {
 561   size_t size;
 562   uint64_t size64;
 563   void *data;
 564   struct GNUNET_DISK_FileHandle *h;
 565   struct GNUNET_DISK_MapHandle *m;
 566
 567   size64 = GNUNET_FS_uri_chk_get_file_size (dc->uri);
 568   size = (size_t) size64;
 569   if (size64 != (uint64_t) size)
 570     {
 571       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 572                   _("Recursive downloads of directories larger than 4 GB are not supported on 32-bit systems\n"));
 573       return;
 574     }
 575   if (dc->filename != NULL)
 576     {
 577       h = GNUNET_DISK_file_open (dc->filename,
 578                                  GNUNET_DISK_OPEN_READ,
 579                                  GNUNET_DISK_PERM_NONE);
 580     }
 581   else
 582     {
 583       GNUNET_assert (dc->temp_filename != NULL);
 584       h = GNUNET_DISK_file_open (dc->temp_filename,
 585                                  GNUNET_DISK_OPEN_READ,
 586                                  GNUNET_DISK_PERM_NONE);
 587     }
 588   if (h == NULL)
 589     return; /* oops */
 590   data = GNUNET_DISK_file_map (h, &m, GNUNET_DISK_MAP_TYPE_READ, size);
 591   if (data == NULL)
 592     {
 593       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 594                   _("Directory too large for system address space\n"));
 595     }
 596   else
 597     {
 598       GNUNET_FS_directory_list_contents (size,
 599                                          data,
 600                                          0,
 601                                          &trigger_recursive_download,
 602                                          dc);
 603       GNUNET_DISK_file_unmap (m);
 604     }
 605   GNUNET_DISK_file_close (h);
 606   if (dc->filename == NULL)
 607     {
 608       if (0 != UNLINK (dc->temp_filename))
 609         GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
 610                                   "unlink",
 611                                   dc->temp_filename);
 612       GNUNET_free (dc->temp_filename);
 613       dc->temp_filename = NULL;
 614     }
 615 }
 616
 617
 618 /**
 619  * Check if all child-downloads have completed and
 620  * if so, signal completion (and possibly recurse to
 621  * parent).
 622  */
 623 static void
 624 check_completed (struct GNUNET_FS_DownloadContext *dc)
 625 {
 626   struct GNUNET_FS_ProgressInfo pi;
 627   struct GNUNET_FS_DownloadContext *pos;
 628
 629   pos = dc->child_head;
 630   while (pos != NULL)
 631     {
 632       if ( (pos->emsg == NULL) &&
 633            (pos->completed < pos->length) )
 634         return; /* not done yet */
 635       if ( (pos->child_head != NULL) &&
 636            (pos->has_finished != GNUNET_YES) )
 637         return; /* not transitively done yet */
 638       pos = pos->next;
 639     }
 640   dc->has_finished = GNUNET_YES;
 641   GNUNET_FS_download_sync_ (dc);
 642   /* signal completion */
 643   pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
 644   GNUNET_FS_download_make_status_ (&pi, dc);
 645   if (dc->parent != NULL)
 646     check_completed (dc->parent);
 647 }
 648
 649
 650 /**
 651  * We found an entry in a directory.  Check if the respective child
 652  * already exists and if not create the respective child download.
 653  *
 654  * @param cls the parent download
 655  * @param filename name of the file in the directory
 656  * @param uri URI of the file (CHK or LOC)
 657  * @param meta meta data of the file
 658  * @param length number of bytes in data
 659  * @param data contents of the file (or NULL if they were not inlined)
 660  */
 661 static void
 662 trigger_recursive_download (void *cls,
 663                             const char *filename,
 664                             const struct GNUNET_FS_Uri *uri,
 665                             const struct GNUNET_CONTAINER_MetaData *meta,
 666                             size_t length,
 667                             const void *data)
 668 {
 669   struct GNUNET_FS_DownloadContext *dc = cls;
 670   struct GNUNET_FS_DownloadContext *cpos;
 671   struct GNUNET_DISK_FileHandle *fh;
 672   char *temp_name;
 673   const char *real_name;
 674   char *fn;
 675   char *us;
 676   char *ext;
 677   char *dn;
 678   char *full_name;
 679
 680   if (NULL == uri)
 681     return; /* entry for the directory itself */
 682   cpos = dc->child_head;
 683   while (cpos != NULL)
 684     {
 685       if ( (GNUNET_FS_uri_test_equal (uri,
 686                                       cpos->uri)) ||
 687            ( (filename != NULL) &&
 688              (0 == strcmp (cpos->filename,
 689                            filename)) ) )
 690         break;
 691       cpos = cpos->next;
 692     }
 693   if (cpos != NULL)
 694     return; /* already exists */
 695   fn = NULL;
 696   if (NULL == filename)
 697     {
 698       fn = GNUNET_FS_meta_data_suggest_filename (meta);
 699       if (fn == NULL)
 700         {
 701           us = GNUNET_FS_uri_to_string (uri);
 702           fn = GNUNET_strdup (&us [strlen (GNUNET_FS_URI_PREFIX
 703                                            GNUNET_FS_URI_CHK_INFIX)]);
 704           GNUNET_free (us);
 705         }
 706       else if (fn[0] == '.')
 707         {
 708           ext = fn;
 709           us = GNUNET_FS_uri_to_string (uri);
 710           GNUNET_asprintf (&fn,
 711                            "%s%s",
 712                            &us[strlen (GNUNET_FS_URI_PREFIX
 713                                        GNUNET_FS_URI_CHK_INFIX)], ext);
 714           GNUNET_free (ext);
 715           GNUNET_free (us);
 716         }
 717       filename = fn;
 718     }
 719   if (dc->filename == NULL)
 720     {
 721       full_name = NULL;
 722     }
 723   else
 724     {
 725       dn = GNUNET_strdup (dc->filename);
 726       GNUNET_break ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
 727                      (NULL !=
 728                       strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
 729                               GNUNET_FS_DIRECTORY_EXT)) );
 730       if ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
 731            (NULL !=
 732             strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
 733                     GNUNET_FS_DIRECTORY_EXT)) )
 734         dn[strlen(dn) - strlen (GNUNET_FS_DIRECTORY_EXT)] = '\0';
 735       if ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (meta)) &&
 736            ( (strlen (filename) < strlen (GNUNET_FS_DIRECTORY_EXT)) ||
 737              (NULL ==
 738               strstr (filename + strlen(filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
 739                       GNUNET_FS_DIRECTORY_EXT)) ) )
 740         {
 741           GNUNET_asprintf (&full_name,
 742                            "%s%s%s%s",
 743                            dn,
 744                            DIR_SEPARATOR_STR,
 745                            filename,
 746                            GNUNET_FS_DIRECTORY_EXT);
 747         }
 748       else
 749         {
 750           GNUNET_asprintf (&full_name,
 751                            "%s%s%s",
 752                            dn,
 753                            DIR_SEPARATOR_STR,
 754                            filename);
 755         }
 756       GNUNET_free (dn);
 757     }
 758   if ( (full_name != NULL) &&
 759        (GNUNET_OK !=
 760         GNUNET_DISK_directory_create_for_file (full_name)) )
 761     {
 762       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 763                   _("Failed to create directory for recursive download of `%s'\n"),
 764                   full_name);
 765       GNUNET_free (full_name);
 766       GNUNET_free_non_null (fn);
 767       return;
 768     }
 769
 770   temp_name = NULL;
 771   if ( (data != NULL) &&
 772        (GNUNET_FS_uri_chk_get_file_size (uri) == length) )
 773     {
 774       if (full_name == NULL)
 775         {
 776           temp_name = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
 777           real_name = temp_name;
 778         }
 779       else
 780         {
 781           real_name = full_name;
 782         }
 783       /* write to disk, then trigger normal download which will instantly progress to completion */
 784       fh = GNUNET_DISK_file_open (real_name,
 785                                   GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_TRUNCATE | GNUNET_DISK_OPEN_CREATE,
 786                                   GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE);
 787       if (fh == NULL)
 788         {
 789           GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
 790                                     "open",
 791                                     real_name);
 792           GNUNET_free (full_name);
 793           GNUNET_free_non_null (fn);
 794           return;
 795         }
 796       if (length !=
 797           GNUNET_DISK_file_write (fh,
 798                                   data,
 799                                   length))
 800         {
 801           GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
 802                                     "write",
 803                                     full_name);
 804         }
 805       GNUNET_DISK_file_close (fh);
 806     }
 807   GNUNET_FS_download_start (dc->h,
 808                             uri,
 809                             meta,
 810                             full_name, temp_name,
 811                             0,
 812                             GNUNET_FS_uri_chk_get_file_size (uri),
 813                             dc->anonymity,
 814                             dc->options,
 815                             NULL,
 816                             dc);
 817   GNUNET_free_non_null (full_name);
 818   GNUNET_free_non_null (temp_name);
 819   GNUNET_free_non_null (fn);
 820 }
 821
 822
 823 /**
 824  * Free entries in the map.
 825  *
 826  * @param cls unused (NULL)
 827  * @param key unused
 828  * @param entry entry of type "struct DownloadRequest" which is freed
 829  * @return GNUNET_OK
 830  */
 831 static int
 832 free_entry (void *cls,
 833             const GNUNET_HashCode *key,
 834             void *entry)
 835 {
 836   GNUNET_free (entry);
 837   return GNUNET_OK;
 838 }
 839
 840
 841 /**
 842  * Iterator over entries in the pending requests in the 'active' map for the
 843  * reply that we just got.
 844  *
 845  * @param cls closure (our 'struct ProcessResultClosure')
 846  * @param key query for the given value / request
 847  * @param value value in the hash map (a 'struct DownloadRequest')
 848  * @return GNUNET_YES (we should continue to iterate); unless serious error
 849  */
 850 static int
 851 process_result_with_request (void *cls,
 852                              const GNUNET_HashCode * key,
 853                              void *value)
 854 {
 855   struct ProcessResultClosure *prc = cls;
 856   struct DownloadRequest *sm = value;
 857   struct DownloadRequest *ppos;
 858   struct DownloadRequest *pprev;
 859   struct GNUNET_DISK_FileHandle *fh;
 860   struct GNUNET_FS_DownloadContext *dc = prc->dc;
 861   struct GNUNET_CRYPTO_AesSessionKey skey;
 862   struct GNUNET_CRYPTO_AesInitializationVector iv;
 863   char pt[prc->size];
 864   struct GNUNET_FS_ProgressInfo pi;
 865   uint64_t off;
 866   size_t bs;
 867   size_t app;
 868   int i;
 869   struct ContentHashKey *chk;
 870
 871   fh = NULL;
 872   bs = GNUNET_FS_tree_calculate_block_size (GNUNET_ntohll (dc->uri->data.chk.file_length),
 873                                             dc->treedepth,
 874                                             sm->offset,
 875                                             sm->depth);
 876   if (prc->size != bs)
 877     {
 878 #if DEBUG_DOWNLOAD
 879       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 880                   "Internal error or bogus download URI (expected %u bytes, got %u)\n",
 881                   bs,
 882                   prc->size);
 883 #endif
 884       dc->emsg = GNUNET_strdup ("Internal error or bogus download URI");
 885       goto signal_error;
 886     }
 887   GNUNET_assert (GNUNET_YES ==
 888                  GNUNET_CONTAINER_multihashmap_remove (dc->active,
 889                                                        &prc->query,
 890                                                        sm));
 891   /* if this request is on the pending list, remove it! */
 892   pprev = NULL;
 893   ppos = dc->pending;
 894   while (ppos != NULL)
 895     {
 896       if (ppos == sm)
 897         {
 898           if (pprev == NULL)
 899             dc->pending = ppos->next;
 900           else
 901             pprev->next = ppos->next;
 902           break;
 903         }
 904       pprev = ppos;
 905       ppos = ppos->next;
 906     }
 907   GNUNET_CRYPTO_hash_to_aes_key (&sm->chk.key, &skey, &iv);
 908   GNUNET_CRYPTO_aes_decrypt (prc->data,
 909                              prc->size,
 910                              &skey,
 911                              &iv,
 912                              pt);
 913   off = compute_disk_offset (GNUNET_ntohll (dc->uri->data.chk.file_length),
 914                              sm->offset,
 915                              sm->depth,
 916                              dc->treedepth);
 917   /* save to disk */
 918   if ( ( GNUNET_YES == prc->do_store) &&
 919        ( (dc->filename != NULL) ||
 920          (is_recursive_download (dc)) ) &&
 921        ( (sm->depth == dc->treedepth) ||
 922          (0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES)) ) )
 923     {
 924       fh = GNUNET_DISK_file_open (dc->filename != NULL
 925                                   ? dc->filename
 926                                   : dc->temp_filename,
 927                                   GNUNET_DISK_OPEN_READWRITE |
 928                                   GNUNET_DISK_OPEN_CREATE,
 929                                   GNUNET_DISK_PERM_USER_READ |
 930                                   GNUNET_DISK_PERM_USER_WRITE |
 931                                   GNUNET_DISK_PERM_GROUP_READ |
 932                                   GNUNET_DISK_PERM_OTHER_READ);
 933     }
 934   if ( (NULL == fh) &&
 935        (GNUNET_YES == prc->do_store) &&
 936        ( (dc->filename != NULL) ||
 937          (is_recursive_download (dc)) ) &&
 938        ( (sm->depth == dc->treedepth) ||
 939          (0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES)) ) )
 940     {
 941       GNUNET_asprintf (&dc->emsg,
 942                        _("Download failed: could not open file `%s': %s\n"),
 943                        dc->filename,
 944                        STRERROR (errno));
 945       goto signal_error;
 946     }
 947   if (fh != NULL)
 948     {
 949 #if DEBUG_DOWNLOAD
 950       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 951                   "Saving decrypted block to disk at offset %llu\n",
 952                   (unsigned long long) off);
 953 #endif
 954       if ( (off  !=
 955             GNUNET_DISK_file_seek (fh,
 956                                    off,
 957                                    GNUNET_DISK_SEEK_SET) ) )
 958         {
 959           GNUNET_asprintf (&dc->emsg,
 960                            _("Failed to seek to offset %llu in file `%s': %s\n"),
 961                            (unsigned long long) off,
 962                            dc->filename,
 963                            STRERROR (errno));
 964           goto signal_error;
 965         }
 966       if (prc->size !=
 967           GNUNET_DISK_file_write (fh,
 968                                   pt,
 969                                   prc->size))
 970         {
 971           GNUNET_asprintf (&dc->emsg,
 972                            _("Failed to write block of %u bytes at offset %llu in file `%s': %s\n"),
 973                            (unsigned int) prc->size,
 974                            (unsigned long long) off,
 975                            dc->filename,
 976                            STRERROR (errno));
 977           goto signal_error;
 978         }
 979       GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
 980       fh = NULL;
 981     }
 982   if (sm->depth == dc->treedepth)
 983     {
 984       app = prc->size;
 985       if (sm->offset < dc->offset)
 986         {
 987           /* starting offset begins in the middle of pt,
 988              do not count first bytes as progress */
 989           GNUNET_assert (app > (dc->offset - sm->offset));
 990           app -= (dc->offset - sm->offset);
 991         }
 992       if (sm->offset + prc->size > dc->offset + dc->length)
 993         {
 994           /* end of block is after relevant range,
 995              do not count last bytes as progress */
 996           GNUNET_assert (app > (sm->offset + prc->size) - (dc->offset + dc->length));
 997           app -= (sm->offset + prc->size) - (dc->offset + dc->length);
 998         }
 999       dc->completed += app;
1000
1001       /* do recursive download if option is set and either meta data
1002          says it is a directory or if no meta data is given AND filename
1003          ends in '.gnd' (top-level case) */
1004       if (is_recursive_download (dc))
1005         GNUNET_FS_directory_list_contents (prc->size,
1006                                            pt,
1007                                            off,
1008                                            &trigger_recursive_download,
1009                                            dc);
1010
1011     }
1012   pi.status = GNUNET_FS_STATUS_DOWNLOAD_PROGRESS;
1013   pi.value.download.specifics.progress.data = pt;
1014   pi.value.download.specifics.progress.offset = sm->offset;
1015   pi.value.download.specifics.progress.data_len = prc->size;
1016   pi.value.download.specifics.progress.depth = sm->depth;
1017   GNUNET_FS_download_make_status_ (&pi, dc);
1018   GNUNET_assert (dc->completed <= dc->length);
1019   if (dc->completed == dc->length)
1020     {
1021 #if DEBUG_DOWNLOAD
1022       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1023                   "Download completed, truncating file to desired length %llu\n",
1024                   (unsigned long long) GNUNET_ntohll (dc->uri->data.chk.file_length));
1025 #endif
1026       /* truncate file to size (since we store IBlocks at the end) */
1027       if (dc->filename != NULL)
1028         {
1029           if (0 != truncate (dc->filename,
1030                              GNUNET_ntohll (dc->uri->data.chk.file_length)))
1031             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
1032                                       "truncate",
1033                                       dc->filename);
1034         }
1035       if (dc->job_queue != NULL)
1036         {
1037           GNUNET_FS_dequeue_ (dc->job_queue);
1038           dc->job_queue = NULL;
1039         }
1040       if (is_recursive_download (dc))
1041         full_recursive_download (dc);
1042       if (dc->child_head == NULL)
1043         {
1044           /* signal completion */
1045           pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
1046           GNUNET_FS_download_make_status_ (&pi, dc);
1047           if (dc->parent != NULL)
1048             check_completed (dc->parent);
1049         }
1050       GNUNET_assert (sm->depth == dc->treedepth);
1051     }
1052   if (sm->depth == dc->treedepth)
1053     {
1054       GNUNET_FS_download_sync_ (dc);
1055       GNUNET_free (sm);
1056       return GNUNET_YES;
1057     }
1058 #if DEBUG_DOWNLOAD
1059   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1060               "Triggering downloads of children (this block was at depth %u and offset %llu)\n",
1061               sm->depth,
1062               (unsigned long long) sm->offset);
1063 #endif
1064   GNUNET_assert (0 == (prc->size % sizeof(struct ContentHashKey)));
1065   chk = (struct ContentHashKey*) pt;
1066   for (i=(prc->size / sizeof(struct ContentHashKey))-1;i>=0;i--)
1067     {
1068       off = compute_dblock_offset (sm->offset,
1069                                    sm->depth,
1070                                    dc->treedepth,
1071                                    i);
1072       if ( (off + DBLOCK_SIZE >= dc->offset) &&
1073            (off < dc->offset + dc->length) )
1074         schedule_block_download (dc,
1075                                  &chk[i],
1076                                  off,
1077                                  sm->depth + 1);
1078     }
1079   GNUNET_free (sm);
1080   GNUNET_FS_download_sync_ (dc);
1081   return GNUNET_YES;
1082
1083  signal_error:
1084   if (fh != NULL)
1085     GNUNET_DISK_file_close (fh);
1086   pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
1087   pi.value.download.specifics.error.message = dc->emsg;
1088   GNUNET_FS_download_make_status_ (&pi, dc);
1089   /* abort all pending requests */
1090   if (NULL != dc->th)
1091     {
1092       GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1093       dc->th = NULL;
1094     }
1095   GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1096   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1097                                          &free_entry,
1098                                          NULL);
1099   dc->pending = NULL;
1100   dc->client = NULL;
1101   GNUNET_free (sm);
1102   GNUNET_FS_download_sync_ (dc);
1103   return GNUNET_NO;
1104 }
1105
1106
1107 /**
1108  * Process a download result.
1109  *
1110  * @param dc our download context
1111  * @param type type of the result
1112  * @param data the (encrypted) response
1113  * @param size size of data
1114  */
1115 static void
1116 process_result (struct GNUNET_FS_DownloadContext *dc,
1117                 enum GNUNET_BLOCK_Type type,
1118                 const void *data,
1119                 size_t size)
1120 {
1121   struct ProcessResultClosure prc;
1122
1123   prc.dc = dc;
1124   prc.data = data;
1125   prc.size = size;
1126   prc.type = type;
1127   prc.do_store = GNUNET_YES;
1128   GNUNET_CRYPTO_hash (data, size, &prc.query);
1129 #if DEBUG_DOWNLOAD
1130   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1131               "Received result for query `%s' from `%s'-service\n",
1132               GNUNET_h2s (&prc.query),
1133               "FS");
1134 #endif
1135   GNUNET_CONTAINER_multihashmap_get_multiple (dc->active,
1136                                               &prc.query,
1137                                               &process_result_with_request,
1138                                               &prc);
1139 }
1140
1141
1142 /**
1143  * Type of a function to call when we receive a message
1144  * from the service.
1145  *
1146  * @param cls closure
1147  * @param msg message received, NULL on timeout or fatal error
1148  */
1149 static void
1150 receive_results (void *cls,
1151                  const struct GNUNET_MessageHeader * msg)
1152 {
1153   struct GNUNET_FS_DownloadContext *dc = cls;
1154   const struct PutMessage *cm;
1155   uint16_t msize;
1156
1157   if ( (NULL == msg) ||
1158        (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_FS_PUT) ||
1159        (sizeof (struct PutMessage) > ntohs(msg->size)) )
1160     {
1161       GNUNET_break (msg == NULL);
1162       try_reconnect (dc);
1163       return;
1164     }
1165   msize = ntohs(msg->size);
1166   cm = (const struct PutMessage*) msg;
1167   process_result (dc,
1168                   ntohl (cm->type),
1169                   &cm[1],
1170                   msize - sizeof (struct PutMessage));
1171   if (dc->client == NULL)
1172     return; /* fatal error */
1173   /* continue receiving */
1174   GNUNET_CLIENT_receive (dc->client,
1175                          &receive_results,
1176                          dc,
1177                          GNUNET_TIME_UNIT_FOREVER_REL);
1178 }
1179
1180
1181
1182 /**
1183  * We're ready to transmit a search request to the
1184  * file-sharing service.  Do it.  If there is
1185  * more than one request pending, try to send
1186  * multiple or request another transmission.
1187  *
1188  * @param cls closure
1189  * @param size number of bytes available in buf
1190  * @param buf where the callee should write the message
1191  * @return number of bytes written to buf
1192  */
1193 static size_t
1194 transmit_download_request (void *cls,
1195                            size_t size,
1196                            void *buf)
1197 {
1198   struct GNUNET_FS_DownloadContext *dc = cls;
1199   size_t msize;
1200   struct SearchMessage *sm;
1201
1202   dc->th = NULL;
1203   if (NULL == buf)
1204     {
1205       try_reconnect (dc);
1206       return 0;
1207     }
1208   GNUNET_assert (size >= sizeof (struct SearchMessage));
1209   msize = 0;
1210   sm = buf;
1211   while ( (dc->pending != NULL) &&
1212           (size > msize + sizeof (struct SearchMessage)) )
1213     {
1214 #if DEBUG_DOWNLOAD
1215       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1216                   "Transmitting download request for `%s' to `%s'-service\n",
1217                   GNUNET_h2s (&dc->pending->chk.query),
1218                   "FS");
1219 #endif
1220       memset (sm, 0, sizeof (struct SearchMessage));
1221       sm->header.size = htons (sizeof (struct SearchMessage));
1222       sm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_START_SEARCH);
1223       if (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_LOOPBACK_ONLY))
1224         sm->options = htonl (1);
1225       else
1226         sm->options = htonl (0);
1227       if (dc->pending->depth == dc->treedepth)
1228         sm->type = htonl (GNUNET_BLOCK_TYPE_DBLOCK);
1229       else
1230         sm->type = htonl (GNUNET_BLOCK_TYPE_IBLOCK);
1231       sm->anonymity_level = htonl (dc->anonymity);
1232       sm->target = dc->target.hashPubKey;
1233       sm->query = dc->pending->chk.query;
1234       dc->pending->is_pending = GNUNET_NO;
1235       dc->pending = dc->pending->next;
1236       msize += sizeof (struct SearchMessage);
1237       sm++;
1238     }
1239   if (dc->pending != NULL)
1240     dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
1241                                                   sizeof (struct SearchMessage),
1242                                                   GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1243                                                   GNUNET_NO,
1244                                                   &transmit_download_request,
1245                                                   dc);
1246   return msize;
1247 }
1248
1249
1250 /**
1251  * Reconnect to the FS service and transmit our queries NOW.
1252  *
1253  * @param cls our download context
1254  * @param tc unused
1255  */
1256 static void
1257 do_reconnect (void *cls,
1258               const struct GNUNET_SCHEDULER_TaskContext *tc)
1259 {
1260   struct GNUNET_FS_DownloadContext *dc = cls;
1261   struct GNUNET_CLIENT_Connection *client;
1262
1263   dc->task = GNUNET_SCHEDULER_NO_TASK;
1264   client = GNUNET_CLIENT_connect (dc->h->sched,
1265                                   "fs",
1266                                   dc->h->cfg);
1267   if (NULL == client)
1268     {
1269       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1270                   "Connecting to `%s'-service failed, will try again.\n",
1271                   "FS");
1272       try_reconnect (dc);
1273       return;
1274     }
1275   dc->client = client;
1276   dc->th = GNUNET_CLIENT_notify_transmit_ready (client,
1277                                                 sizeof (struct SearchMessage),
1278                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1279                                                 GNUNET_NO,
1280                                                 &transmit_download_request,
1281                                                 dc);
1282   GNUNET_CLIENT_receive (client,
1283                          &receive_results,
1284                          dc,
1285                          GNUNET_TIME_UNIT_FOREVER_REL);
1286 }
1287
1288
1289 /**
1290  * Add entries that are not yet pending back to the pending list.
1291  *
1292  * @param cls our download context
1293  * @param key unused
1294  * @param entry entry of type "struct DownloadRequest"
1295  * @return GNUNET_OK
1296  */
1297 static int
1298 retry_entry (void *cls,
1299              const GNUNET_HashCode *key,
1300              void *entry)
1301 {
1302   struct GNUNET_FS_DownloadContext *dc = cls;
1303   struct DownloadRequest *dr = entry;
1304
1305   if (! dr->is_pending)
1306     {
1307       dr->next = dc->pending;
1308       dr->is_pending = GNUNET_YES;
1309       dc->pending = entry;
1310     }
1311   return GNUNET_OK;
1312 }
1313
1314
1315 /**
1316  * We've lost our connection with the FS service.
1317  * Re-establish it and re-transmit all of our
1318  * pending requests.
1319  *
1320  * @param dc download context that is having trouble
1321  */
1322 static void
1323 try_reconnect (struct GNUNET_FS_DownloadContext *dc)
1324 {
1325
1326   if (NULL != dc->client)
1327     {
1328       if (NULL != dc->th)
1329         {
1330           GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1331           dc->th = NULL;
1332         }
1333       GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1334                                              &retry_entry,
1335                                              dc);
1336       GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1337       dc->client = NULL;
1338     }
1339   dc->task
1340     = GNUNET_SCHEDULER_add_delayed (dc->h->sched,
1341                                     GNUNET_TIME_UNIT_SECONDS,
1342                                     &do_reconnect,
1343                                     dc);
1344 }
1345
1346
1347
1348 /**
1349  * We're allowed to ask the FS service for our blocks.  Start the download.
1350  *
1351  * @param cls the 'struct GNUNET_FS_DownloadContext'
1352  * @param client handle to use for communcation with FS (we must destroy it!)
1353  */
1354 static void
1355 activate_fs_download (void *cls,
1356                       struct GNUNET_CLIENT_Connection *client)
1357 {
1358   struct GNUNET_FS_DownloadContext *dc = cls;
1359   struct GNUNET_FS_ProgressInfo pi;
1360
1361   GNUNET_assert (NULL != client);
1362   GNUNET_assert (dc->client == NULL);
1363   GNUNET_assert (dc->th == NULL);
1364   dc->client = client;
1365   GNUNET_CLIENT_receive (client,
1366                          &receive_results,
1367                          dc,
1368                          GNUNET_TIME_UNIT_FOREVER_REL);
1369   pi.status = GNUNET_FS_STATUS_DOWNLOAD_ACTIVE;
1370   GNUNET_FS_download_make_status_ (&pi, dc);
1371   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1372                                          &retry_entry,
1373                                          dc);
1374   dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
1375                                                 sizeof (struct SearchMessage),
1376                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1377                                                 GNUNET_NO,
1378                                                 &transmit_download_request,
1379                                                 dc);
1380 }
1381
1382
1383 /**
1384  * We must stop to ask the FS service for our blocks.  Pause the download.
1385  *
1386  * @param cls the 'struct GNUNET_FS_DownloadContext'
1387  */
1388 static void
1389 deactivate_fs_download (void *cls)
1390 {
1391   struct GNUNET_FS_DownloadContext *dc = cls;
1392   struct GNUNET_FS_ProgressInfo pi;
1393
1394   if (NULL != dc->th)
1395     {
1396       GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1397       dc->th = NULL;
1398     }
1399   if (NULL != dc->client)
1400     {
1401       GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1402       dc->client = NULL;
1403     }
1404   pi.status = GNUNET_FS_STATUS_DOWNLOAD_INACTIVE;
1405   GNUNET_FS_download_make_status_ (&pi, dc);
1406 }
1407
1408
1409 /**
1410  * Create SUSPEND event for the given download operation
1411  * and then clean up our state (without stop signal).
1412  *
1413  * @param cls the 'struct GNUNET_FS_DownloadContext' to signal for
1414  */
1415 void
1416 GNUNET_FS_download_signal_suspend_ (void *cls)
1417 {
1418   struct GNUNET_FS_DownloadContext *dc = cls;
1419   struct GNUNET_FS_ProgressInfo pi;
1420
1421   if (dc->top != NULL)
1422     GNUNET_FS_end_top (dc->h, dc->top);
1423   while (NULL != dc->child_head)
1424     GNUNET_FS_download_signal_suspend_ (dc->child_head);
1425   if (dc->search != NULL)
1426     {
1427       dc->search->download = NULL;
1428       dc->search = NULL;
1429     }
1430   if (dc->job_queue != NULL)
1431     {
1432       GNUNET_FS_dequeue_ (dc->job_queue);
1433       dc->job_queue = NULL;
1434     }
1435   if (dc->parent != NULL)
1436     GNUNET_CONTAINER_DLL_remove (dc->parent->child_head,
1437                                  dc->parent->child_tail,
1438                                  dc);
1439   pi.status = GNUNET_FS_STATUS_DOWNLOAD_SUSPEND;
1440   GNUNET_FS_download_make_status_ (&pi, dc);
1441   if (GNUNET_SCHEDULER_NO_TASK != dc->task)
1442     GNUNET_SCHEDULER_cancel (dc->h->sched,
1443                              dc->task);
1444   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1445                                          &free_entry,
1446                                          NULL);
1447   GNUNET_CONTAINER_multihashmap_destroy (dc->active);
1448   GNUNET_free_non_null (dc->filename);
1449   GNUNET_CONTAINER_meta_data_destroy (dc->meta);
1450   GNUNET_FS_uri_destroy (dc->uri);
1451   GNUNET_free_non_null (dc->temp_filename);
1452   GNUNET_free_non_null (dc->serialization);
1453   GNUNET_free (dc);
1454 }
1455
1456
1457 /**
1458  * Download parts of a file.  Note that this will store
1459  * the blocks at the respective offset in the given file.  Also, the
1460  * download is still using the blocking of the underlying FS
1461  * encoding.  As a result, the download may *write* outside of the
1462  * given boundaries (if offset and length do not match the 32k FS
1463  * block boundaries). <p>
1464  *
1465  * This function should be used to focus a download towards a
1466  * particular portion of the file (optimization), not to strictly
1467  * limit the download to exactly those bytes.
1468  *
1469  * @param h handle to the file sharing subsystem
1470  * @param uri the URI of the file (determines what to download); CHK or LOC URI
1471  * @param meta known metadata for the file (can be NULL)
1472  * @param filename where to store the file, maybe NULL (then no file is
1473  *        created on disk and data must be grabbed from the callbacks)
1474  * @param tempname where to store temporary file data, not used if filename is non-NULL;
1475  *        can be NULL (in which case we will pick a name if needed); the temporary file
1476  *        may already exist, in which case we will try to use the data that is there and
1477  *        if it is not what is desired, will overwrite it
1478  * @param offset at what offset should we start the download (typically 0)
1479  * @param length how many bytes should be downloaded starting at offset
1480  * @param anonymity anonymity level to use for the download
1481  * @param options various options
1482  * @param cctx initial value for the client context for this download
1483  * @param parent parent download to associate this download with (use NULL
1484  *        for top-level downloads; useful for manually-triggered recursive downloads)
1485  * @return context that can be used to control this download
1486  */
1487 struct GNUNET_FS_DownloadContext *
1488 GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
1489                           const struct GNUNET_FS_Uri *uri,
1490                           const struct GNUNET_CONTAINER_MetaData *meta,
1491                           const char *filename,
1492                           const char *tempname,
1493                           uint64_t offset,
1494                           uint64_t length,
1495                           uint32_t anonymity,
1496                           enum GNUNET_FS_DownloadOptions options,
1497                           void *cctx,
1498                           struct GNUNET_FS_DownloadContext *parent)
1499 {
1500   struct GNUNET_FS_ProgressInfo pi;
1501   struct GNUNET_FS_DownloadContext *dc;
1502
1503   GNUNET_assert (GNUNET_FS_uri_test_chk (uri));
1504   if ( (offset + length < offset) ||
1505        (offset + length > uri->data.chk.file_length) )
1506     {
1507       GNUNET_break (0);
1508       return NULL;
1509     }
1510 #if DEBUG_DOWNLOAD
1511   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1512               "Starting download `%s' of %llu bytes\n",
1513               filename,
1514               (unsigned long long) length);
1515 #endif
1516   dc = GNUNET_malloc (sizeof(struct GNUNET_FS_DownloadContext));
1517   dc->h = h;
1518   dc->parent = parent;
1519   if (parent != NULL)
1520     {
1521       GNUNET_CONTAINER_DLL_insert (parent->child_head,
1522                                    parent->child_tail,
1523                                    dc);
1524     }
1525   dc->uri = GNUNET_FS_uri_dup (uri);
1526   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (meta);
1527   dc->client_info = cctx;
1528   dc->start_time = GNUNET_TIME_absolute_get ();
1529   if (NULL != filename)
1530     {
1531       dc->filename = GNUNET_strdup (filename);
1532       if (GNUNET_YES == GNUNET_DISK_file_test (filename))
1533         GNUNET_DISK_file_size (filename,
1534                                &dc->old_file_size,
1535                                GNUNET_YES);
1536     }
1537   if (GNUNET_FS_uri_test_loc (dc->uri))
1538     GNUNET_assert (GNUNET_OK ==
1539                    GNUNET_FS_uri_loc_get_peer_identity (dc->uri,
1540                                                         &dc->target));
1541   dc->offset = offset;
1542   dc->length = length;
1543   dc->anonymity = anonymity;
1544   dc->options = options;
1545   dc->active = GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
1546   dc->treedepth = GNUNET_FS_compute_depth (GNUNET_ntohll(dc->uri->data.chk.file_length));
1547   if ( (filename == NULL) &&
1548        (is_recursive_download (dc) ) )
1549     {
1550       if (tempname != NULL)
1551         dc->temp_filename = GNUNET_strdup (tempname);
1552       else
1553         dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
1554     }
1555
1556 #if DEBUG_DOWNLOAD
1557   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1558               "Download tree has depth %u\n",
1559               dc->treedepth);
1560 #endif
1561   if (parent == NULL)
1562     {
1563       dc->top = GNUNET_FS_make_top (dc->h,
1564                                     &GNUNET_FS_download_signal_suspend_,
1565                                     dc);
1566     }
1567   pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
1568   pi.value.download.specifics.start.meta = meta;
1569   GNUNET_FS_download_make_status_ (&pi, dc);
1570   schedule_block_download (dc,
1571                            &dc->uri->data.chk.chk,
1572                            0,
1573                            1 /* 0 == CHK, 1 == top */);
1574   GNUNET_FS_download_sync_ (dc);
1575   GNUNET_FS_download_start_downloading_ (dc);
1576   return dc;
1577 }
1578
1579
1580 /**
1581  * Download parts of a file based on a search result.  The download
1582  * will be associated with the search result (and the association
1583  * will be preserved when serializing/deserializing the state).
1584  * If the search is stopped, the download will not be aborted but
1585  * be 'promoted' to a stand-alone download.
1586  *
1587  * As with the other download function, this will store
1588  * the blocks at the respective offset in the given file.  Also, the
1589  * download is still using the blocking of the underlying FS
1590  * encoding.  As a result, the download may *write* outside of the
1591  * given boundaries (if offset and length do not match the 32k FS
1592  * block boundaries). <p>
1593  *
1594  * The given range can be used to focus a download towards a
1595  * particular portion of the file (optimization), not to strictly
1596  * limit the download to exactly those bytes.
1597  *
1598  * @param h handle to the file sharing subsystem
1599  * @param sr the search result to use for the download (determines uri and
1600  *        meta data and associations)
1601  * @param filename where to store the file, maybe NULL (then no file is
1602  *        created on disk and data must be grabbed from the callbacks)
1603  * @param tempname where to store temporary file data, not used if filename is non-NULL;
1604  *        can be NULL (in which case we will pick a name if needed); the temporary file
1605  *        may already exist, in which case we will try to use the data that is there and
1606  *        if it is not what is desired, will overwrite it
1607  * @param offset at what offset should we start the download (typically 0)
1608  * @param length how many bytes should be downloaded starting at offset
1609  * @param anonymity anonymity level to use for the download
1610  * @param options various download options
1611  * @param cctx initial value for the client context for this download
1612  * @return context that can be used to control this download
1613  */
1614 struct GNUNET_FS_DownloadContext *
1615 GNUNET_FS_download_start_from_search (struct GNUNET_FS_Handle *h,
1616                                       struct GNUNET_FS_SearchResult *sr,
1617                                       const char *filename,
1618                                       const char *tempname,
1619                                       uint64_t offset,
1620                                       uint64_t length,
1621                                       uint32_t anonymity,
1622                                       enum GNUNET_FS_DownloadOptions options,
1623                                       void *cctx)
1624 {
1625   struct GNUNET_FS_ProgressInfo pi;
1626   struct GNUNET_FS_DownloadContext *dc;
1627
1628   if (sr->download != NULL)
1629     {
1630       GNUNET_break (0);
1631       return NULL;
1632     }
1633   GNUNET_assert (GNUNET_FS_uri_test_chk (sr->uri));
1634   if ( (offset + length < offset) ||
1635        (offset + length > sr->uri->data.chk.file_length) )
1636     {
1637       GNUNET_break (0);
1638       return NULL;
1639     }
1640 #if DEBUG_DOWNLOAD
1641   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1642               "Starting download `%s' of %llu bytes\n",
1643               filename,
1644               (unsigned long long) length);
1645 #endif
1646   dc = GNUNET_malloc (sizeof(struct GNUNET_FS_DownloadContext));
1647   dc->h = h;
1648   dc->search = sr;
1649   sr->download = dc;
1650   if (sr->probe_ctx != NULL)
1651     {
1652       GNUNET_FS_download_stop (sr->probe_ctx, GNUNET_YES);
1653       sr->probe_ctx = NULL;
1654     }
1655   dc->uri = GNUNET_FS_uri_dup (sr->uri);
1656   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (sr->meta);
1657   dc->client_info = cctx;
1658   dc->start_time = GNUNET_TIME_absolute_get ();
1659   if (NULL != filename)
1660     {
1661       dc->filename = GNUNET_strdup (filename);
1662       if (GNUNET_YES == GNUNET_DISK_file_test (filename))
1663         GNUNET_DISK_file_size (filename,
1664                                &dc->old_file_size,
1665                                GNUNET_YES);
1666     }
1667   if (GNUNET_FS_uri_test_loc (dc->uri))
1668     GNUNET_assert (GNUNET_OK ==
1669                    GNUNET_FS_uri_loc_get_peer_identity (dc->uri,
1670                                                         &dc->target));
1671   dc->offset = offset;
1672   dc->length = length;
1673   dc->anonymity = anonymity;
1674   dc->options = options;
1675   dc->active = GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
1676   dc->treedepth = GNUNET_FS_compute_depth (GNUNET_ntohll(dc->uri->data.chk.file_length));
1677   if ( (filename == NULL) &&
1678        (is_recursive_download (dc) ) )
1679     {
1680       if (tempname != NULL)
1681         dc->temp_filename = GNUNET_strdup (tempname);
1682       else
1683         dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
1684     }
1685
1686 #if DEBUG_DOWNLOAD
1687   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1688               "Download tree has depth %u\n",
1689               dc->treedepth);
1690 #endif
1691   pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
1692   pi.value.download.specifics.start.meta = dc->meta;
1693   GNUNET_FS_download_make_status_ (&pi, dc);
1694   schedule_block_download (dc,
1695                            &dc->uri->data.chk.chk,
1696                            0,
1697                            1 /* 0 == CHK, 1 == top */);
1698   GNUNET_FS_download_sync_ (dc);
1699   GNUNET_FS_download_start_downloading_ (dc);
1700   return dc;
1701 }
1702
1703
1704 /**
1705  * Start the downloading process (by entering the queue).
1706  *
1707  * @param dc our download context
1708  */
1709 void
1710 GNUNET_FS_download_start_downloading_ (struct GNUNET_FS_DownloadContext *dc)
1711 {
1712   GNUNET_assert (dc->job_queue == NULL);
1713   dc->job_queue = GNUNET_FS_queue_ (dc->h,
1714                                     &activate_fs_download,
1715                                     &deactivate_fs_download,
1716                                     dc,
1717                                     (dc->length + DBLOCK_SIZE-1) / DBLOCK_SIZE);
1718 }
1719
1720
1721 /**
1722  * Stop a download (aborts if download is incomplete).
1723  *
1724  * @param dc handle for the download
1725  * @param do_delete delete files of incomplete downloads
1726  */
1727 void
1728 GNUNET_FS_download_stop (struct GNUNET_FS_DownloadContext *dc,
1729                          int do_delete)
1730 {
1731   struct GNUNET_FS_ProgressInfo pi;
1732   int have_children;
1733
1734   if (dc->top != NULL)
1735     GNUNET_FS_end_top (dc->h, dc->top);
1736   if (dc->search != NULL)
1737     {
1738       dc->search->download = NULL;
1739       dc->search = NULL;
1740     }
1741   if (dc->job_queue != NULL)
1742     {
1743       GNUNET_FS_dequeue_ (dc->job_queue);
1744       dc->job_queue = NULL;
1745     }
1746   have_children = (NULL != dc->child_head) ? GNUNET_YES : GNUNET_NO;
1747   while (NULL != dc->child_head)
1748     GNUNET_FS_download_stop (dc->child_head,
1749                              do_delete);
1750   if (dc->parent != NULL)
1751     GNUNET_CONTAINER_DLL_remove (dc->parent->child_head,
1752                                  dc->parent->child_tail,
1753                                  dc);
1754   if (dc->serialization != NULL)
1755     GNUNET_FS_remove_sync_file_ (dc->h,
1756                                  ( (dc->parent != NULL)  || (dc->search != NULL) )
1757                                  ? GNUNET_FS_SYNC_PATH_CHILD_DOWNLOAD
1758                                  : GNUNET_FS_SYNC_PATH_MASTER_DOWNLOAD ,
1759                                  dc->serialization);
1760   if ( (GNUNET_YES == have_children) &&
1761        (dc->parent == NULL) )
1762     GNUNET_FS_remove_sync_dir_ (dc->h,
1763                                 (dc->search != NULL)
1764                                 ? GNUNET_FS_SYNC_PATH_CHILD_DOWNLOAD
1765                                 : GNUNET_FS_SYNC_PATH_MASTER_DOWNLOAD,
1766                                 dc->serialization);
1767   pi.status = GNUNET_FS_STATUS_DOWNLOAD_STOPPED;
1768   GNUNET_FS_download_make_status_ (&pi, dc);
1769   if (GNUNET_SCHEDULER_NO_TASK != dc->task)
1770     GNUNET_SCHEDULER_cancel (dc->h->sched,
1771                              dc->task);
1772   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1773                                          &free_entry,
1774                                          NULL);
1775   GNUNET_CONTAINER_multihashmap_destroy (dc->active);
1776   if (dc->filename != NULL)
1777     {
1778       if ( (dc->completed != dc->length) &&
1779            (GNUNET_YES == do_delete) )
1780         {
1781           if (0 != UNLINK (dc->filename))
1782             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
1783                                       "unlink",
1784                                       dc->filename);
1785         }
1786       GNUNET_free (dc->filename);
1787     }
1788   GNUNET_CONTAINER_meta_data_destroy (dc->meta);
1789   GNUNET_FS_uri_destroy (dc->uri);
1790   if (NULL != dc->temp_filename)
1791     {
1792       if (0 != UNLINK (dc->temp_filename))
1793         GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
1794                                   "unlink",
1795                                   dc->temp_filename);
1796       GNUNET_free (dc->temp_filename);
1797     }
1798   GNUNET_free_non_null (dc->serialization);
1799   GNUNET_free (dc);
1800 }
1801
1802 /* end of fs_download.c */