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_NO
  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           if (-1 == GNUNET_CRYPTO_aes_encrypt (block, len,
 334                                                &sk,
 335                                                &iv,
 336                                                enc))
 337             {
 338               GNUNET_break (0);
 339               goto do_download;
 340             }
 341           GNUNET_CRYPTO_hash (enc, len, &query);
 342           if (0 == memcmp (&query,
 343                            &chk->query,
 344                            sizeof (GNUNET_HashCode)))
 345             {
 346 #if DEBUG_DOWNLOAD
 347               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 348                           "Matching block already present, no need for download!\n");
 349 #endif
 350               /* already got it! */
 351               prc.dc = dc;
 352               prc.data = enc;
 353               prc.size = len;
 354               prc.type = (dc->treedepth == depth)
 355                 ? GNUNET_BLOCK_TYPE_DBLOCK
 356                 : GNUNET_BLOCK_TYPE_IBLOCK;
 357               prc.query = chk->query;
 358               prc.do_store = GNUNET_NO; /* useless */
 359               process_result_with_request (&prc,
 360                                            &key,
 361                                            sm);
 362             }
 363           else
 364             {
 365               GNUNET_break_op (0);
 366             }
 367           GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
 368           return;
 369         }
 370     }
 371  do_download:
 372   if (fh != NULL)
 373     GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
 374   if (depth < dc->treedepth)
 375     {
 376       // FIXME: try if we could
 377       // reconstitute this IBLOCK
 378       // from the existing blocks on disk (can wait)
 379       // (read block(s), encode, compare with
 380       // query; if matches, simply return)
 381     }
 382
 383   if ( (dc->th == NULL) &&
 384        (dc->client != NULL) )
 385     {
 386 #if DEBUG_DOWNLOAD
 387       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 388                   "Asking for transmission to FS service\n");
 389 #endif
 390       dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
 391                                                     sizeof (struct SearchMessage),
 392                                                     GNUNET_CONSTANTS_SERVICE_TIMEOUT,
 393                                                     GNUNET_NO,
 394                                                     &transmit_download_request,
 395                                                     dc);
 396     }
 397 }
 398
 399
 400
 401 /**
 402  * Suggest a filename based on given metadata.
 403  *
 404  * @param md given meta data
 405  * @return NULL if meta data is useless for suggesting a filename
 406  */
 407 char *
 408 GNUNET_FS_meta_data_suggest_filename (const struct GNUNET_CONTAINER_MetaData *md)
 409 {
 410   static const char *mimeMap[][2] = {
 411     {"application/bz2", ".bz2"},
 412     {"application/gnunet-directory", ".gnd"},
 413     {"application/java", ".class"},
 414     {"application/msword", ".doc"},
 415     {"application/ogg", ".ogg"},
 416     {"application/pdf", ".pdf"},
 417     {"application/pgp-keys", ".key"},
 418     {"application/pgp-signature", ".pgp"},
 419     {"application/postscript", ".ps"},
 420     {"application/rar", ".rar"},
 421     {"application/rtf", ".rtf"},
 422     {"application/xml", ".xml"},
 423     {"application/x-debian-package", ".deb"},
 424     {"application/x-dvi", ".dvi"},
 425     {"applixation/x-flac", ".flac"},
 426     {"applixation/x-gzip", ".gz"},
 427     {"application/x-java-archive", ".jar"},
 428     {"application/x-java-vm", ".class"},
 429     {"application/x-python-code", ".pyc"},
 430     {"application/x-redhat-package-manager", ".rpm"},
 431     {"application/x-rpm", ".rpm"},
 432     {"application/x-tar", ".tar"},
 433     {"application/x-tex-pk", ".pk"},
 434     {"application/x-texinfo", ".texinfo"},
 435     {"application/x-xcf", ".xcf"},
 436     {"application/x-xfig", ".xfig"},
 437     {"application/zip", ".zip"},
 438
 439     {"audio/midi", ".midi"},
 440     {"audio/mpeg", ".mp3"},
 441     {"audio/real", ".rm"},
 442     {"audio/x-wav", ".wav"},
 443
 444     {"image/gif", ".gif"},
 445     {"image/jpeg", ".jpg"},
 446     {"image/pcx", ".pcx"},
 447     {"image/png", ".png"},
 448     {"image/tiff", ".tiff"},
 449     {"image/x-ms-bmp", ".bmp"},
 450     {"image/x-xpixmap", ".xpm"},
 451
 452     {"text/css", ".css"},
 453     {"text/html", ".html"},
 454     {"text/plain", ".txt"},
 455     {"text/rtf", ".rtf"},
 456     {"text/x-c++hdr", ".h++"},
 457     {"text/x-c++src", ".c++"},
 458     {"text/x-chdr", ".h"},
 459     {"text/x-csrc", ".c"},
 460     {"text/x-java", ".java"},
 461     {"text/x-moc", ".moc"},
 462     {"text/x-pascal", ".pas"},
 463     {"text/x-perl", ".pl"},
 464     {"text/x-python", ".py"},
 465     {"text/x-tex", ".tex"},
 466
 467     {"video/avi", ".avi"},
 468     {"video/mpeg", ".mpeg"},
 469     {"video/quicktime", ".qt"},
 470     {"video/real", ".rm"},
 471     {"video/x-msvideo", ".avi"},
 472     {NULL, NULL},
 473   };
 474   char *ret;
 475   unsigned int i;
 476   char *mime;
 477   char *base;
 478   const char *ext;
 479
 480   ret = GNUNET_CONTAINER_meta_data_get_by_type (md,
 481                                                 EXTRACTOR_METATYPE_FILENAME);
 482   if (ret != NULL)
 483     return ret;
 484   ext = NULL;
 485   mime = GNUNET_CONTAINER_meta_data_get_by_type (md,
 486                                                  EXTRACTOR_METATYPE_MIMETYPE);
 487   if (mime != NULL)
 488     {
 489       i = 0;
 490       while ( (mimeMap[i][0] != NULL) &&
 491               (0 != strcmp (mime, mimeMap[i][0])))
 492         i++;
 493       if (mimeMap[i][1] == NULL)
 494         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG |
 495                     GNUNET_ERROR_TYPE_BULK,
 496                     _("Did not find mime type `%s' in extension list.\n"),
 497                     mime);
 498       else
 499         ext = mimeMap[i][1];
 500       GNUNET_free (mime);
 501     }
 502   base = GNUNET_CONTAINER_meta_data_get_first_by_types (md,
 503                                                         EXTRACTOR_METATYPE_TITLE,
 504                                                         EXTRACTOR_METATYPE_BOOK_TITLE,
 505                                                         EXTRACTOR_METATYPE_ORIGINAL_TITLE,
 506                                                         EXTRACTOR_METATYPE_PACKAGE_NAME,
 507                                                         EXTRACTOR_METATYPE_URL,
 508                                                         EXTRACTOR_METATYPE_URI,
 509                                                         EXTRACTOR_METATYPE_DESCRIPTION,
 510                                                         EXTRACTOR_METATYPE_ISRC,
 511                                                         EXTRACTOR_METATYPE_JOURNAL_NAME,
 512                                                         EXTRACTOR_METATYPE_AUTHOR_NAME,
 513                                                         EXTRACTOR_METATYPE_SUBJECT,
 514                                                         EXTRACTOR_METATYPE_ALBUM,
 515                                                         EXTRACTOR_METATYPE_ARTIST,
 516                                                         EXTRACTOR_METATYPE_KEYWORDS,
 517                                                         EXTRACTOR_METATYPE_COMMENT,
 518                                                         EXTRACTOR_METATYPE_UNKNOWN,
 519                                                         -1);
 520   if ( (base == NULL) &&
 521        (ext == NULL) )
 522     return NULL;
 523   if (base == NULL)
 524     return GNUNET_strdup (ext);
 525   if (ext == NULL)
 526     return base;
 527   GNUNET_asprintf (&ret,
 528                    "%s%s",
 529                    base,
 530                    ext);
 531   GNUNET_free (base);
 532   return ret;
 533 }
 534
 535
 536 /**
 537  * We've lost our connection with the FS service.
 538  * Re-establish it and re-transmit all of our
 539  * pending requests.
 540  *
 541  * @param dc download context that is having trouble
 542  */
 543 static void
 544 try_reconnect (struct GNUNET_FS_DownloadContext *dc);
 545
 546
 547 /**
 548  * We found an entry in a directory.  Check if the respective child
 549  * already exists and if not create the respective child download.
 550  *
 551  * @param cls the parent download
 552  * @param filename name of the file in the directory
 553  * @param uri URI of the file (CHK or LOC)
 554  * @param meta meta data of the file
 555  * @param length number of bytes in data
 556  * @param data contents of the file (or NULL if they were not inlined)
 557  */
 558 static void
 559 trigger_recursive_download (void *cls,
 560                             const char *filename,
 561                             const struct GNUNET_FS_Uri *uri,
 562                             const struct GNUNET_CONTAINER_MetaData *meta,
 563                             size_t length,
 564                             const void *data);
 565
 566
 567 /**
 568  * We're done downloading a directory.  Open the file and
 569  * trigger all of the (remaining) child downloads.
 570  *
 571  * @param dc context of download that just completed
 572  */
 573 static void
 574 full_recursive_download (struct GNUNET_FS_DownloadContext *dc)
 575 {
 576   size_t size;
 577   uint64_t size64;
 578   void *data;
 579   struct GNUNET_DISK_FileHandle *h;
 580   struct GNUNET_DISK_MapHandle *m;
 581
 582   size64 = GNUNET_FS_uri_chk_get_file_size (dc->uri);
 583   size = (size_t) size64;
 584   if (size64 != (uint64_t) size)
 585     {
 586       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 587                   _("Recursive downloads of directories larger than 4 GB are not supported on 32-bit systems\n"));
 588       return;
 589     }
 590   if (dc->filename != NULL)
 591     {
 592       h = GNUNET_DISK_file_open (dc->filename,
 593                                  GNUNET_DISK_OPEN_READ,
 594                                  GNUNET_DISK_PERM_NONE);
 595     }
 596   else
 597     {
 598       GNUNET_assert (dc->temp_filename != NULL);
 599       h = GNUNET_DISK_file_open (dc->temp_filename,
 600                                  GNUNET_DISK_OPEN_READ,
 601                                  GNUNET_DISK_PERM_NONE);
 602     }
 603   if (h == NULL)
 604     return; /* oops */
 605   data = GNUNET_DISK_file_map (h, &m, GNUNET_DISK_MAP_TYPE_READ, size);
 606   if (data == NULL)
 607     {
 608       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 609                   _("Directory too large for system address space\n"));
 610     }
 611   else
 612     {
 613       GNUNET_FS_directory_list_contents (size,
 614                                          data,
 615                                          0,
 616                                          &trigger_recursive_download,
 617                                          dc);
 618       GNUNET_DISK_file_unmap (m);
 619     }
 620   GNUNET_DISK_file_close (h);
 621   if (dc->filename == NULL)
 622     {
 623       if (0 != UNLINK (dc->temp_filename))
 624         GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
 625                                   "unlink",
 626                                   dc->temp_filename);
 627       GNUNET_free (dc->temp_filename);
 628       dc->temp_filename = NULL;
 629     }
 630 }
 631
 632
 633 /**
 634  * Check if all child-downloads have completed and
 635  * if so, signal completion (and possibly recurse to
 636  * parent).
 637  */
 638 static void
 639 check_completed (struct GNUNET_FS_DownloadContext *dc)
 640 {
 641   struct GNUNET_FS_ProgressInfo pi;
 642   struct GNUNET_FS_DownloadContext *pos;
 643
 644   pos = dc->child_head;
 645   while (pos != NULL)
 646     {
 647       if ( (pos->emsg == NULL) &&
 648            (pos->completed < pos->length) )
 649         return; /* not done yet */
 650       if ( (pos->child_head != NULL) &&
 651            (pos->has_finished != GNUNET_YES) )
 652         return; /* not transitively done yet */
 653       pos = pos->next;
 654     }
 655   dc->has_finished = GNUNET_YES;
 656   GNUNET_FS_download_sync_ (dc);
 657   /* signal completion */
 658   pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
 659   GNUNET_FS_download_make_status_ (&pi, dc);
 660   if (dc->parent != NULL)
 661     check_completed (dc->parent);
 662 }
 663
 664
 665 /**
 666  * We found an entry in a directory.  Check if the respective child
 667  * already exists and if not create the respective child download.
 668  *
 669  * @param cls the parent download
 670  * @param filename name of the file in the directory
 671  * @param uri URI of the file (CHK or LOC)
 672  * @param meta meta data of the file
 673  * @param length number of bytes in data
 674  * @param data contents of the file (or NULL if they were not inlined)
 675  */
 676 static void
 677 trigger_recursive_download (void *cls,
 678                             const char *filename,
 679                             const struct GNUNET_FS_Uri *uri,
 680                             const struct GNUNET_CONTAINER_MetaData *meta,
 681                             size_t length,
 682                             const void *data)
 683 {
 684   struct GNUNET_FS_DownloadContext *dc = cls;
 685   struct GNUNET_FS_DownloadContext *cpos;
 686   struct GNUNET_DISK_FileHandle *fh;
 687   char *temp_name;
 688   const char *real_name;
 689   char *fn;
 690   char *us;
 691   char *ext;
 692   char *dn;
 693   char *full_name;
 694
 695   if (NULL == uri)
 696     return; /* entry for the directory itself */
 697   cpos = dc->child_head;
 698   while (cpos != NULL)
 699     {
 700       if ( (GNUNET_FS_uri_test_equal (uri,
 701                                       cpos->uri)) ||
 702            ( (filename != NULL) &&
 703              (0 == strcmp (cpos->filename,
 704                            filename)) ) )
 705         break;
 706       cpos = cpos->next;
 707     }
 708   if (cpos != NULL)
 709     return; /* already exists */
 710   fn = NULL;
 711   if (NULL == filename)
 712     {
 713       fn = GNUNET_FS_meta_data_suggest_filename (meta);
 714       if (fn == NULL)
 715         {
 716           us = GNUNET_FS_uri_to_string (uri);
 717           fn = GNUNET_strdup (&us [strlen (GNUNET_FS_URI_PREFIX
 718                                            GNUNET_FS_URI_CHK_INFIX)]);
 719           GNUNET_free (us);
 720         }
 721       else if (fn[0] == '.')
 722         {
 723           ext = fn;
 724           us = GNUNET_FS_uri_to_string (uri);
 725           GNUNET_asprintf (&fn,
 726                            "%s%s",
 727                            &us[strlen (GNUNET_FS_URI_PREFIX
 728                                        GNUNET_FS_URI_CHK_INFIX)], ext);
 729           GNUNET_free (ext);
 730           GNUNET_free (us);
 731         }
 732       filename = fn;
 733     }
 734   if (dc->filename == NULL)
 735     {
 736       full_name = NULL;
 737     }
 738   else
 739     {
 740       dn = GNUNET_strdup (dc->filename);
 741       GNUNET_break ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
 742                      (NULL !=
 743                       strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
 744                               GNUNET_FS_DIRECTORY_EXT)) );
 745       if ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
 746            (NULL !=
 747             strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
 748                     GNUNET_FS_DIRECTORY_EXT)) )
 749         dn[strlen(dn) - strlen (GNUNET_FS_DIRECTORY_EXT)] = '\0';
 750       if ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (meta)) &&
 751            ( (strlen (filename) < strlen (GNUNET_FS_DIRECTORY_EXT)) ||
 752              (NULL ==
 753               strstr (filename + strlen(filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
 754                       GNUNET_FS_DIRECTORY_EXT)) ) )
 755         {
 756           GNUNET_asprintf (&full_name,
 757                            "%s%s%s%s",
 758                            dn,
 759                            DIR_SEPARATOR_STR,
 760                            filename,
 761                            GNUNET_FS_DIRECTORY_EXT);
 762         }
 763       else
 764         {
 765           GNUNET_asprintf (&full_name,
 766                            "%s%s%s",
 767                            dn,
 768                            DIR_SEPARATOR_STR,
 769                            filename);
 770         }
 771       GNUNET_free (dn);
 772     }
 773   if ( (full_name != NULL) &&
 774        (GNUNET_OK !=
 775         GNUNET_DISK_directory_create_for_file (full_name)) )
 776     {
 777       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 778                   _("Failed to create directory for recursive download of `%s'\n"),
 779                   full_name);
 780       GNUNET_free (full_name);
 781       GNUNET_free_non_null (fn);
 782       return;
 783     }
 784
 785   temp_name = NULL;
 786   if ( (data != NULL) &&
 787        (GNUNET_FS_uri_chk_get_file_size (uri) == length) )
 788     {
 789       if (full_name == NULL)
 790         {
 791           temp_name = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
 792           real_name = temp_name;
 793         }
 794       else
 795         {
 796           real_name = full_name;
 797         }
 798       /* write to disk, then trigger normal download which will instantly progress to completion */
 799       fh = GNUNET_DISK_file_open (real_name,
 800                                   GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_TRUNCATE | GNUNET_DISK_OPEN_CREATE,
 801                                   GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE);
 802       if (fh == NULL)
 803         {
 804           GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
 805                                     "open",
 806                                     real_name);
 807           GNUNET_free (full_name);
 808           GNUNET_free_non_null (fn);
 809           return;
 810         }
 811       if (length !=
 812           GNUNET_DISK_file_write (fh,
 813                                   data,
 814                                   length))
 815         {
 816           GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
 817                                     "write",
 818                                     full_name);
 819         }
 820       GNUNET_DISK_file_close (fh);
 821     }
 822   GNUNET_FS_download_start (dc->h,
 823                             uri,
 824                             meta,
 825                             full_name, temp_name,
 826                             0,
 827                             GNUNET_FS_uri_chk_get_file_size (uri),
 828                             dc->anonymity,
 829                             dc->options,
 830                             NULL,
 831                             dc);
 832   GNUNET_free_non_null (full_name);
 833   GNUNET_free_non_null (temp_name);
 834   GNUNET_free_non_null (fn);
 835 }
 836
 837
 838 /**
 839  * Free entries in the map.
 840  *
 841  * @param cls unused (NULL)
 842  * @param key unused
 843  * @param entry entry of type "struct DownloadRequest" which is freed
 844  * @return GNUNET_OK
 845  */
 846 static int
 847 free_entry (void *cls,
 848             const GNUNET_HashCode *key,
 849             void *entry)
 850 {
 851   GNUNET_free (entry);
 852   return GNUNET_OK;
 853 }
 854
 855
 856 /**
 857  * Iterator over entries in the pending requests in the 'active' map for the
 858  * reply that we just got.
 859  *
 860  * @param cls closure (our 'struct ProcessResultClosure')
 861  * @param key query for the given value / request
 862  * @param value value in the hash map (a 'struct DownloadRequest')
 863  * @return GNUNET_YES (we should continue to iterate); unless serious error
 864  */
 865 static int
 866 process_result_with_request (void *cls,
 867                              const GNUNET_HashCode * key,
 868                              void *value)
 869 {
 870   struct ProcessResultClosure *prc = cls;
 871   struct DownloadRequest *sm = value;
 872   struct DownloadRequest *ppos;
 873   struct DownloadRequest *pprev;
 874   struct GNUNET_DISK_FileHandle *fh;
 875   struct GNUNET_FS_DownloadContext *dc = prc->dc;
 876   struct GNUNET_CRYPTO_AesSessionKey skey;
 877   struct GNUNET_CRYPTO_AesInitializationVector iv;
 878   char pt[prc->size];
 879   struct GNUNET_FS_ProgressInfo pi;
 880   uint64_t off;
 881   size_t bs;
 882   size_t app;
 883   int i;
 884   struct ContentHashKey *chk;
 885
 886   fh = NULL;
 887   bs = GNUNET_FS_tree_calculate_block_size (GNUNET_ntohll (dc->uri->data.chk.file_length),
 888                                             dc->treedepth,
 889                                             sm->offset,
 890                                             sm->depth);
 891   if (prc->size != bs)
 892     {
 893 #if DEBUG_DOWNLOAD
 894       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 895                   "Internal error or bogus download URI (expected %u bytes, got %u)\n",
 896                   bs,
 897                   prc->size);
 898 #endif
 899       dc->emsg = GNUNET_strdup ("Internal error or bogus download URI");
 900       goto signal_error;
 901     }
 902   GNUNET_assert (GNUNET_YES ==
 903                  GNUNET_CONTAINER_multihashmap_remove (dc->active,
 904                                                        &prc->query,
 905                                                        sm));
 906   /* if this request is on the pending list, remove it! */
 907   pprev = NULL;
 908   ppos = dc->pending;
 909   while (ppos != NULL)
 910     {
 911       if (ppos == sm)
 912         {
 913           if (pprev == NULL)
 914             dc->pending = ppos->next;
 915           else
 916             pprev->next = ppos->next;
 917           break;
 918         }
 919       pprev = ppos;
 920       ppos = ppos->next;
 921     }
 922   GNUNET_CRYPTO_hash_to_aes_key (&sm->chk.key, &skey, &iv);
 923   if (-1 == GNUNET_CRYPTO_aes_decrypt (prc->data,
 924                                        prc->size,
 925                                        &skey,
 926                                        &iv,
 927                                        pt))
 928     {
 929       GNUNET_break (0);
 930       dc->emsg = GNUNET_strdup ("internal error decrypting content");
 931       goto signal_error;
 932     }
 933   off = compute_disk_offset (GNUNET_ntohll (dc->uri->data.chk.file_length),
 934                              sm->offset,
 935                              sm->depth,
 936                              dc->treedepth);
 937   /* save to disk */
 938   if ( ( GNUNET_YES == prc->do_store) &&
 939        ( (dc->filename != NULL) ||
 940          (is_recursive_download (dc)) ) &&
 941        ( (sm->depth == dc->treedepth) ||
 942          (0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES)) ) )
 943     {
 944       fh = GNUNET_DISK_file_open (dc->filename != NULL
 945                                   ? dc->filename
 946                                   : dc->temp_filename,
 947                                   GNUNET_DISK_OPEN_READWRITE |
 948                                   GNUNET_DISK_OPEN_CREATE,
 949                                   GNUNET_DISK_PERM_USER_READ |
 950                                   GNUNET_DISK_PERM_USER_WRITE |
 951                                   GNUNET_DISK_PERM_GROUP_READ |
 952                                   GNUNET_DISK_PERM_OTHER_READ);
 953     }
 954   if ( (NULL == fh) &&
 955        (GNUNET_YES == prc->do_store) &&
 956        ( (dc->filename != NULL) ||
 957          (is_recursive_download (dc)) ) &&
 958        ( (sm->depth == dc->treedepth) ||
 959          (0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES)) ) )
 960     {
 961       GNUNET_asprintf (&dc->emsg,
 962                        _("Download failed: could not open file `%s': %s\n"),
 963                        dc->filename,
 964                        STRERROR (errno));
 965       goto signal_error;
 966     }
 967   if (fh != NULL)
 968     {
 969 #if DEBUG_DOWNLOAD
 970       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 971                   "Saving decrypted block to disk at offset %llu\n",
 972                   (unsigned long long) off);
 973 #endif
 974       if ( (off  !=
 975             GNUNET_DISK_file_seek (fh,
 976                                    off,
 977                                    GNUNET_DISK_SEEK_SET) ) )
 978         {
 979           GNUNET_asprintf (&dc->emsg,
 980                            _("Failed to seek to offset %llu in file `%s': %s\n"),
 981                            (unsigned long long) off,
 982                            dc->filename,
 983                            STRERROR (errno));
 984           goto signal_error;
 985         }
 986       if (prc->size !=
 987           GNUNET_DISK_file_write (fh,
 988                                   pt,
 989                                   prc->size))
 990         {
 991           GNUNET_asprintf (&dc->emsg,
 992                            _("Failed to write block of %u bytes at offset %llu in file `%s': %s\n"),
 993                            (unsigned int) prc->size,
 994                            (unsigned long long) off,
 995                            dc->filename,
 996                            STRERROR (errno));
 997           goto signal_error;
 998         }
 999       GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
1000       fh = NULL;
1001     }
1002   if (sm->depth == dc->treedepth)
1003     {
1004       app = prc->size;
1005       if (sm->offset < dc->offset)
1006         {
1007           /* starting offset begins in the middle of pt,
1008              do not count first bytes as progress */
1009           GNUNET_assert (app > (dc->offset - sm->offset));
1010           app -= (dc->offset - sm->offset);
1011         }
1012       if (sm->offset + prc->size > dc->offset + dc->length)
1013         {
1014           /* end of block is after relevant range,
1015              do not count last bytes as progress */
1016           GNUNET_assert (app > (sm->offset + prc->size) - (dc->offset + dc->length));
1017           app -= (sm->offset + prc->size) - (dc->offset + dc->length);
1018         }
1019       dc->completed += app;
1020
1021       /* do recursive download if option is set and either meta data
1022          says it is a directory or if no meta data is given AND filename
1023          ends in '.gnd' (top-level case) */
1024       if (is_recursive_download (dc))
1025         GNUNET_FS_directory_list_contents (prc->size,
1026                                            pt,
1027                                            off,
1028                                            &trigger_recursive_download,
1029                                            dc);
1030
1031     }
1032   pi.status = GNUNET_FS_STATUS_DOWNLOAD_PROGRESS;
1033   pi.value.download.specifics.progress.data = pt;
1034   pi.value.download.specifics.progress.offset = sm->offset;
1035   pi.value.download.specifics.progress.data_len = prc->size;
1036   pi.value.download.specifics.progress.depth = sm->depth;
1037   GNUNET_FS_download_make_status_ (&pi, dc);
1038   GNUNET_assert (dc->completed <= dc->length);
1039   if (dc->completed == dc->length)
1040     {
1041 #if DEBUG_DOWNLOAD
1042       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1043                   "Download completed, truncating file to desired length %llu\n",
1044                   (unsigned long long) GNUNET_ntohll (dc->uri->data.chk.file_length));
1045 #endif
1046       /* truncate file to size (since we store IBlocks at the end) */
1047       if (dc->filename != NULL)
1048         {
1049           if (0 != truncate (dc->filename,
1050                              GNUNET_ntohll (dc->uri->data.chk.file_length)))
1051             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
1052                                       "truncate",
1053                                       dc->filename);
1054         }
1055       if (dc->job_queue != NULL)
1056         {
1057           GNUNET_FS_dequeue_ (dc->job_queue);
1058           dc->job_queue = NULL;
1059         }
1060       if (is_recursive_download (dc))
1061         full_recursive_download (dc);
1062       if (dc->child_head == NULL)
1063         {
1064           /* signal completion */
1065           pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
1066           GNUNET_FS_download_make_status_ (&pi, dc);
1067           if (dc->parent != NULL)
1068             check_completed (dc->parent);
1069         }
1070       GNUNET_assert (sm->depth == dc->treedepth);
1071     }
1072   if (sm->depth == dc->treedepth)
1073     {
1074       GNUNET_FS_download_sync_ (dc);
1075       GNUNET_free (sm);
1076       return GNUNET_YES;
1077     }
1078 #if DEBUG_DOWNLOAD
1079   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1080               "Triggering downloads of children (this block was at depth %u and offset %llu)\n",
1081               sm->depth,
1082               (unsigned long long) sm->offset);
1083 #endif
1084   GNUNET_assert (0 == (prc->size % sizeof(struct ContentHashKey)));
1085   chk = (struct ContentHashKey*) pt;
1086   for (i=(prc->size / sizeof(struct ContentHashKey))-1;i>=0;i--)
1087     {
1088       off = compute_dblock_offset (sm->offset,
1089                                    sm->depth,
1090                                    dc->treedepth,
1091                                    i);
1092       if ( (off + DBLOCK_SIZE >= dc->offset) &&
1093            (off < dc->offset + dc->length) )
1094         schedule_block_download (dc,
1095                                  &chk[i],
1096                                  off,
1097                                  sm->depth + 1);
1098     }
1099   GNUNET_free (sm);
1100   GNUNET_FS_download_sync_ (dc);
1101   return GNUNET_YES;
1102
1103  signal_error:
1104   if (fh != NULL)
1105     GNUNET_DISK_file_close (fh);
1106   pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
1107   pi.value.download.specifics.error.message = dc->emsg;
1108   GNUNET_FS_download_make_status_ (&pi, dc);
1109   /* abort all pending requests */
1110   if (NULL != dc->th)
1111     {
1112       GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1113       dc->th = NULL;
1114     }
1115   GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1116   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1117                                          &free_entry,
1118                                          NULL);
1119   dc->pending = NULL;
1120   dc->client = NULL;
1121   GNUNET_free (sm);
1122   GNUNET_FS_download_sync_ (dc);
1123   return GNUNET_NO;
1124 }
1125
1126
1127 /**
1128  * Process a download result.
1129  *
1130  * @param dc our download context
1131  * @param type type of the result
1132  * @param data the (encrypted) response
1133  * @param size size of data
1134  */
1135 static void
1136 process_result (struct GNUNET_FS_DownloadContext *dc,
1137                 enum GNUNET_BLOCK_Type type,
1138                 const void *data,
1139                 size_t size)
1140 {
1141   struct ProcessResultClosure prc;
1142
1143   prc.dc = dc;
1144   prc.data = data;
1145   prc.size = size;
1146   prc.type = type;
1147   prc.do_store = GNUNET_YES;
1148   GNUNET_CRYPTO_hash (data, size, &prc.query);
1149 #if DEBUG_DOWNLOAD
1150   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1151               "Received result for query `%s' from `%s'-service\n",
1152               GNUNET_h2s (&prc.query),
1153               "FS");
1154 #endif
1155   GNUNET_CONTAINER_multihashmap_get_multiple (dc->active,
1156                                               &prc.query,
1157                                               &process_result_with_request,
1158                                               &prc);
1159 }
1160
1161
1162 /**
1163  * Type of a function to call when we receive a message
1164  * from the service.
1165  *
1166  * @param cls closure
1167  * @param msg message received, NULL on timeout or fatal error
1168  */
1169 static void
1170 receive_results (void *cls,
1171                  const struct GNUNET_MessageHeader * msg)
1172 {
1173   struct GNUNET_FS_DownloadContext *dc = cls;
1174   const struct PutMessage *cm;
1175   uint16_t msize;
1176
1177   if ( (NULL == msg) ||
1178        (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_FS_PUT) ||
1179        (sizeof (struct PutMessage) > ntohs(msg->size)) )
1180     {
1181       GNUNET_break (msg == NULL);
1182       try_reconnect (dc);
1183       return;
1184     }
1185   msize = ntohs(msg->size);
1186   cm = (const struct PutMessage*) msg;
1187   process_result (dc,
1188                   ntohl (cm->type),
1189                   &cm[1],
1190                   msize - sizeof (struct PutMessage));
1191   if (dc->client == NULL)
1192     return; /* fatal error */
1193   /* continue receiving */
1194   GNUNET_CLIENT_receive (dc->client,
1195                          &receive_results,
1196                          dc,
1197                          GNUNET_TIME_UNIT_FOREVER_REL);
1198 }
1199
1200
1201
1202 /**
1203  * We're ready to transmit a search request to the
1204  * file-sharing service.  Do it.  If there is
1205  * more than one request pending, try to send
1206  * multiple or request another transmission.
1207  *
1208  * @param cls closure
1209  * @param size number of bytes available in buf
1210  * @param buf where the callee should write the message
1211  * @return number of bytes written to buf
1212  */
1213 static size_t
1214 transmit_download_request (void *cls,
1215                            size_t size,
1216                            void *buf)
1217 {
1218   struct GNUNET_FS_DownloadContext *dc = cls;
1219   size_t msize;
1220   struct SearchMessage *sm;
1221
1222   dc->th = NULL;
1223   if (NULL == buf)
1224     {
1225 #if DEBUG_DOWNLOAD
1226       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1227                   "Transmitting download request failed, trying to reconnect\n");
1228 #endif
1229       try_reconnect (dc);
1230       return 0;
1231     }
1232   GNUNET_assert (size >= sizeof (struct SearchMessage));
1233   msize = 0;
1234   sm = buf;
1235   while ( (dc->pending != NULL) &&
1236           (size > msize + sizeof (struct SearchMessage)) )
1237     {
1238 #if DEBUG_DOWNLOAD
1239       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1240                   "Transmitting download request for `%s' to `%s'-service\n",
1241                   GNUNET_h2s (&dc->pending->chk.query),
1242                   "FS");
1243 #endif
1244       memset (sm, 0, sizeof (struct SearchMessage));
1245       sm->header.size = htons (sizeof (struct SearchMessage));
1246       sm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_START_SEARCH);
1247       if (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_LOOPBACK_ONLY))
1248         sm->options = htonl (1);
1249       else
1250         sm->options = htonl (0);
1251       if (dc->pending->depth == dc->treedepth)
1252         sm->type = htonl (GNUNET_BLOCK_TYPE_DBLOCK);
1253       else
1254         sm->type = htonl (GNUNET_BLOCK_TYPE_IBLOCK);
1255       sm->anonymity_level = htonl (dc->anonymity);
1256       sm->target = dc->target.hashPubKey;
1257       sm->query = dc->pending->chk.query;
1258       dc->pending->is_pending = GNUNET_NO;
1259       dc->pending = dc->pending->next;
1260       msize += sizeof (struct SearchMessage);
1261       sm++;
1262     }
1263   if (dc->pending != NULL)
1264     dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
1265                                                   sizeof (struct SearchMessage),
1266                                                   GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1267                                                   GNUNET_NO,
1268                                                   &transmit_download_request,
1269                                                   dc);
1270   return msize;
1271 }
1272
1273
1274 /**
1275  * Reconnect to the FS service and transmit our queries NOW.
1276  *
1277  * @param cls our download context
1278  * @param tc unused
1279  */
1280 static void
1281 do_reconnect (void *cls,
1282               const struct GNUNET_SCHEDULER_TaskContext *tc)
1283 {
1284   struct GNUNET_FS_DownloadContext *dc = cls;
1285   struct GNUNET_CLIENT_Connection *client;
1286
1287   dc->task = GNUNET_SCHEDULER_NO_TASK;
1288   client = GNUNET_CLIENT_connect (dc->h->sched,
1289                                   "fs",
1290                                   dc->h->cfg);
1291   if (NULL == client)
1292     {
1293       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1294                   "Connecting to `%s'-service failed, will try again.\n",
1295                   "FS");
1296       try_reconnect (dc);
1297       return;
1298     }
1299   dc->client = client;
1300   dc->th = GNUNET_CLIENT_notify_transmit_ready (client,
1301                                                 sizeof (struct SearchMessage),
1302                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1303                                                 GNUNET_NO,
1304                                                 &transmit_download_request,
1305                                                 dc);
1306   GNUNET_CLIENT_receive (client,
1307                          &receive_results,
1308                          dc,
1309                          GNUNET_TIME_UNIT_FOREVER_REL);
1310 }
1311
1312
1313 /**
1314  * Add entries that are not yet pending back to the pending list.
1315  *
1316  * @param cls our download context
1317  * @param key unused
1318  * @param entry entry of type "struct DownloadRequest"
1319  * @return GNUNET_OK
1320  */
1321 static int
1322 retry_entry (void *cls,
1323              const GNUNET_HashCode *key,
1324              void *entry)
1325 {
1326   struct GNUNET_FS_DownloadContext *dc = cls;
1327   struct DownloadRequest *dr = entry;
1328
1329   if (! dr->is_pending)
1330     {
1331       dr->next = dc->pending;
1332       dr->is_pending = GNUNET_YES;
1333       dc->pending = entry;
1334     }
1335   return GNUNET_OK;
1336 }
1337
1338
1339 /**
1340  * We've lost our connection with the FS service.
1341  * Re-establish it and re-transmit all of our
1342  * pending requests.
1343  *
1344  * @param dc download context that is having trouble
1345  */
1346 static void
1347 try_reconnect (struct GNUNET_FS_DownloadContext *dc)
1348 {
1349
1350   if (NULL != dc->client)
1351     {
1352 #if DEBUG_DOWNLOAD
1353       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1354                   "Moving all requests back to pending list\n");
1355 #endif
1356       if (NULL != dc->th)
1357         {
1358           GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1359           dc->th = NULL;
1360         }
1361       GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1362                                              &retry_entry,
1363                                              dc);
1364       GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1365       dc->client = NULL;
1366     }
1367 #if DEBUG_DOWNLOAD
1368   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1369               "Will try to reconnect in 1s\n");
1370 #endif
1371   dc->task
1372     = GNUNET_SCHEDULER_add_delayed (dc->h->sched,
1373                                     GNUNET_TIME_UNIT_SECONDS,
1374                                     &do_reconnect,
1375                                     dc);
1376 }
1377
1378
1379
1380 /**
1381  * We're allowed to ask the FS service for our blocks.  Start the download.
1382  *
1383  * @param cls the 'struct GNUNET_FS_DownloadContext'
1384  * @param client handle to use for communcation with FS (we must destroy it!)
1385  */
1386 static void
1387 activate_fs_download (void *cls,
1388                       struct GNUNET_CLIENT_Connection *client)
1389 {
1390   struct GNUNET_FS_DownloadContext *dc = cls;
1391   struct GNUNET_FS_ProgressInfo pi;
1392
1393   GNUNET_assert (NULL != client);
1394   GNUNET_assert (dc->client == NULL);
1395   GNUNET_assert (dc->th == NULL);
1396   dc->client = client;
1397   GNUNET_CLIENT_receive (client,
1398                          &receive_results,
1399                          dc,
1400                          GNUNET_TIME_UNIT_FOREVER_REL);
1401   pi.status = GNUNET_FS_STATUS_DOWNLOAD_ACTIVE;
1402   GNUNET_FS_download_make_status_ (&pi, dc);
1403   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1404                                          &retry_entry,
1405                                          dc);
1406   dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
1407                                                 sizeof (struct SearchMessage),
1408                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1409                                                 GNUNET_NO,
1410                                                 &transmit_download_request,
1411                                                 dc);
1412 }
1413
1414
1415 /**
1416  * We must stop to ask the FS service for our blocks.  Pause the download.
1417  *
1418  * @param cls the 'struct GNUNET_FS_DownloadContext'
1419  */
1420 static void
1421 deactivate_fs_download (void *cls)
1422 {
1423   struct GNUNET_FS_DownloadContext *dc = cls;
1424   struct GNUNET_FS_ProgressInfo pi;
1425
1426   if (NULL != dc->th)
1427     {
1428       GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1429       dc->th = NULL;
1430     }
1431   if (NULL != dc->client)
1432     {
1433       GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1434       dc->client = NULL;
1435     }
1436   pi.status = GNUNET_FS_STATUS_DOWNLOAD_INACTIVE;
1437   GNUNET_FS_download_make_status_ (&pi, dc);
1438 }
1439
1440
1441 /**
1442  * Create SUSPEND event for the given download operation
1443  * and then clean up our state (without stop signal).
1444  *
1445  * @param cls the 'struct GNUNET_FS_DownloadContext' to signal for
1446  */
1447 void
1448 GNUNET_FS_download_signal_suspend_ (void *cls)
1449 {
1450   struct GNUNET_FS_DownloadContext *dc = cls;
1451   struct GNUNET_FS_ProgressInfo pi;
1452
1453   if (dc->top != NULL)
1454     GNUNET_FS_end_top (dc->h, dc->top);
1455   while (NULL != dc->child_head)
1456     GNUNET_FS_download_signal_suspend_ (dc->child_head);
1457   if (dc->search != NULL)
1458     {
1459       dc->search->download = NULL;
1460       dc->search = NULL;
1461     }
1462   if (dc->job_queue != NULL)
1463     {
1464       GNUNET_FS_dequeue_ (dc->job_queue);
1465       dc->job_queue = NULL;
1466     }
1467   if (dc->parent != NULL)
1468     GNUNET_CONTAINER_DLL_remove (dc->parent->child_head,
1469                                  dc->parent->child_tail,
1470                                  dc);
1471   pi.status = GNUNET_FS_STATUS_DOWNLOAD_SUSPEND;
1472   GNUNET_FS_download_make_status_ (&pi, dc);
1473   if (GNUNET_SCHEDULER_NO_TASK != dc->task)
1474     GNUNET_SCHEDULER_cancel (dc->h->sched,
1475                              dc->task);
1476   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1477                                          &free_entry,
1478                                          NULL);
1479   GNUNET_CONTAINER_multihashmap_destroy (dc->active);
1480   GNUNET_free_non_null (dc->filename);
1481   GNUNET_CONTAINER_meta_data_destroy (dc->meta);
1482   GNUNET_FS_uri_destroy (dc->uri);
1483   GNUNET_free_non_null (dc->temp_filename);
1484   GNUNET_free_non_null (dc->serialization);
1485   GNUNET_free (dc);
1486 }
1487
1488
1489 /**
1490  * Download parts of a file.  Note that this will store
1491  * the blocks at the respective offset in the given file.  Also, the
1492  * download is still using the blocking of the underlying FS
1493  * encoding.  As a result, the download may *write* outside of the
1494  * given boundaries (if offset and length do not match the 32k FS
1495  * block boundaries). <p>
1496  *
1497  * This function should be used to focus a download towards a
1498  * particular portion of the file (optimization), not to strictly
1499  * limit the download to exactly those bytes.
1500  *
1501  * @param h handle to the file sharing subsystem
1502  * @param uri the URI of the file (determines what to download); CHK or LOC URI
1503  * @param meta known metadata for the file (can be NULL)
1504  * @param filename where to store the file, maybe NULL (then no file is
1505  *        created on disk and data must be grabbed from the callbacks)
1506  * @param tempname where to store temporary file data, not used if filename is non-NULL;
1507  *        can be NULL (in which case we will pick a name if needed); the temporary file
1508  *        may already exist, in which case we will try to use the data that is there and
1509  *        if it is not what is desired, will overwrite it
1510  * @param offset at what offset should we start the download (typically 0)
1511  * @param length how many bytes should be downloaded starting at offset
1512  * @param anonymity anonymity level to use for the download
1513  * @param options various options
1514  * @param cctx initial value for the client context for this download
1515  * @param parent parent download to associate this download with (use NULL
1516  *        for top-level downloads; useful for manually-triggered recursive downloads)
1517  * @return context that can be used to control this download
1518  */
1519 struct GNUNET_FS_DownloadContext *
1520 GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
1521                           const struct GNUNET_FS_Uri *uri,
1522                           const struct GNUNET_CONTAINER_MetaData *meta,
1523                           const char *filename,
1524                           const char *tempname,
1525                           uint64_t offset,
1526                           uint64_t length,
1527                           uint32_t anonymity,
1528                           enum GNUNET_FS_DownloadOptions options,
1529                           void *cctx,
1530                           struct GNUNET_FS_DownloadContext *parent)
1531 {
1532   struct GNUNET_FS_ProgressInfo pi;
1533   struct GNUNET_FS_DownloadContext *dc;
1534
1535   GNUNET_assert (GNUNET_FS_uri_test_chk (uri));
1536   if ( (offset + length < offset) ||
1537        (offset + length > uri->data.chk.file_length) )
1538     {
1539       GNUNET_break (0);
1540       return NULL;
1541     }
1542 #if DEBUG_DOWNLOAD
1543   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1544               "Starting download `%s' of %llu bytes\n",
1545               filename,
1546               (unsigned long long) length);
1547 #endif
1548   dc = GNUNET_malloc (sizeof(struct GNUNET_FS_DownloadContext));
1549   dc->h = h;
1550   dc->parent = parent;
1551   if (parent != NULL)
1552     {
1553       GNUNET_CONTAINER_DLL_insert (parent->child_head,
1554                                    parent->child_tail,
1555                                    dc);
1556     }
1557   dc->uri = GNUNET_FS_uri_dup (uri);
1558   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (meta);
1559   dc->client_info = cctx;
1560   dc->start_time = GNUNET_TIME_absolute_get ();
1561   if (NULL != filename)
1562     {
1563       dc->filename = GNUNET_strdup (filename);
1564       if (GNUNET_YES == GNUNET_DISK_file_test (filename))
1565         GNUNET_DISK_file_size (filename,
1566                                &dc->old_file_size,
1567                                GNUNET_YES);
1568     }
1569   if (GNUNET_FS_uri_test_loc (dc->uri))
1570     GNUNET_assert (GNUNET_OK ==
1571                    GNUNET_FS_uri_loc_get_peer_identity (dc->uri,
1572                                                         &dc->target));
1573   dc->offset = offset;
1574   dc->length = length;
1575   dc->anonymity = anonymity;
1576   dc->options = options;
1577   dc->active = GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
1578   dc->treedepth = GNUNET_FS_compute_depth (GNUNET_ntohll(dc->uri->data.chk.file_length));
1579   if ( (filename == NULL) &&
1580        (is_recursive_download (dc) ) )
1581     {
1582       if (tempname != NULL)
1583         dc->temp_filename = GNUNET_strdup (tempname);
1584       else
1585         dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
1586     }
1587
1588 #if DEBUG_DOWNLOAD
1589   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1590               "Download tree has depth %u\n",
1591               dc->treedepth);
1592 #endif
1593   if (parent == NULL)
1594     {
1595       dc->top = GNUNET_FS_make_top (dc->h,
1596                                     &GNUNET_FS_download_signal_suspend_,
1597                                     dc);
1598     }
1599   pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
1600   pi.value.download.specifics.start.meta = meta;
1601   GNUNET_FS_download_make_status_ (&pi, dc);
1602   schedule_block_download (dc,
1603                            &dc->uri->data.chk.chk,
1604                            0,
1605                            1 /* 0 == CHK, 1 == top */);
1606   GNUNET_FS_download_sync_ (dc);
1607   GNUNET_FS_download_start_downloading_ (dc);
1608   return dc;
1609 }
1610
1611
1612 /**
1613  * Download parts of a file based on a search result.  The download
1614  * will be associated with the search result (and the association
1615  * will be preserved when serializing/deserializing the state).
1616  * If the search is stopped, the download will not be aborted but
1617  * be 'promoted' to a stand-alone download.
1618  *
1619  * As with the other download function, this will store
1620  * the blocks at the respective offset in the given file.  Also, the
1621  * download is still using the blocking of the underlying FS
1622  * encoding.  As a result, the download may *write* outside of the
1623  * given boundaries (if offset and length do not match the 32k FS
1624  * block boundaries). <p>
1625  *
1626  * The given range can be used to focus a download towards a
1627  * particular portion of the file (optimization), not to strictly
1628  * limit the download to exactly those bytes.
1629  *
1630  * @param h handle to the file sharing subsystem
1631  * @param sr the search result to use for the download (determines uri and
1632  *        meta data and associations)
1633  * @param filename where to store the file, maybe NULL (then no file is
1634  *        created on disk and data must be grabbed from the callbacks)
1635  * @param tempname where to store temporary file data, not used if filename is non-NULL;
1636  *        can be NULL (in which case we will pick a name if needed); the temporary file
1637  *        may already exist, in which case we will try to use the data that is there and
1638  *        if it is not what is desired, will overwrite it
1639  * @param offset at what offset should we start the download (typically 0)
1640  * @param length how many bytes should be downloaded starting at offset
1641  * @param anonymity anonymity level to use for the download
1642  * @param options various download options
1643  * @param cctx initial value for the client context for this download
1644  * @return context that can be used to control this download
1645  */
1646 struct GNUNET_FS_DownloadContext *
1647 GNUNET_FS_download_start_from_search (struct GNUNET_FS_Handle *h,
1648                                       struct GNUNET_FS_SearchResult *sr,
1649                                       const char *filename,
1650                                       const char *tempname,
1651                                       uint64_t offset,
1652                                       uint64_t length,
1653                                       uint32_t anonymity,
1654                                       enum GNUNET_FS_DownloadOptions options,
1655                                       void *cctx)
1656 {
1657   struct GNUNET_FS_ProgressInfo pi;
1658   struct GNUNET_FS_DownloadContext *dc;
1659
1660   if ( (sr == NULL) ||
1661        (sr->download != NULL) )
1662     {
1663       GNUNET_break (0);
1664       return NULL;
1665     }
1666   GNUNET_assert (GNUNET_FS_uri_test_chk (sr->uri));
1667   if ( (offset + length < offset) ||
1668        (offset + length > sr->uri->data.chk.file_length) )
1669     {
1670       GNUNET_break (0);
1671       return NULL;
1672     }
1673 #if DEBUG_DOWNLOAD
1674   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1675               "Starting download `%s' of %llu bytes\n",
1676               filename,
1677               (unsigned long long) length);
1678 #endif
1679   dc = GNUNET_malloc (sizeof(struct GNUNET_FS_DownloadContext));
1680   dc->h = h;
1681   dc->search = sr;
1682   sr->download = dc;
1683   if (sr->probe_ctx != NULL)
1684     {
1685       GNUNET_FS_download_stop (sr->probe_ctx, GNUNET_YES);
1686       sr->probe_ctx = NULL;
1687     }
1688   dc->uri = GNUNET_FS_uri_dup (sr->uri);
1689   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (sr->meta);
1690   dc->client_info = cctx;
1691   dc->start_time = GNUNET_TIME_absolute_get ();
1692   if (NULL != filename)
1693     {
1694       dc->filename = GNUNET_strdup (filename);
1695       if (GNUNET_YES == GNUNET_DISK_file_test (filename))
1696         GNUNET_DISK_file_size (filename,
1697                                &dc->old_file_size,
1698                                GNUNET_YES);
1699     }
1700   if (GNUNET_FS_uri_test_loc (dc->uri))
1701     GNUNET_assert (GNUNET_OK ==
1702                    GNUNET_FS_uri_loc_get_peer_identity (dc->uri,
1703                                                         &dc->target));
1704   dc->offset = offset;
1705   dc->length = length;
1706   dc->anonymity = anonymity;
1707   dc->options = options;
1708   dc->active = GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
1709   dc->treedepth = GNUNET_FS_compute_depth (GNUNET_ntohll(dc->uri->data.chk.file_length));
1710   if ( (filename == NULL) &&
1711        (is_recursive_download (dc) ) )
1712     {
1713       if (tempname != NULL)
1714         dc->temp_filename = GNUNET_strdup (tempname);
1715       else
1716         dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
1717     }
1718
1719 #if DEBUG_DOWNLOAD
1720   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1721               "Download tree has depth %u\n",
1722               dc->treedepth);
1723 #endif
1724   pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
1725   pi.value.download.specifics.start.meta = dc->meta;
1726   GNUNET_FS_download_make_status_ (&pi, dc);
1727   schedule_block_download (dc,
1728                            &dc->uri->data.chk.chk,
1729                            0,
1730                            1 /* 0 == CHK, 1 == top */);
1731   GNUNET_FS_download_sync_ (dc);
1732   GNUNET_FS_download_start_downloading_ (dc);
1733   return dc;
1734 }
1735
1736
1737 /**
1738  * Start the downloading process (by entering the queue).
1739  *
1740  * @param dc our download context
1741  */
1742 void
1743 GNUNET_FS_download_start_downloading_ (struct GNUNET_FS_DownloadContext *dc)
1744 {
1745   GNUNET_assert (dc->job_queue == NULL);
1746   dc->job_queue = GNUNET_FS_queue_ (dc->h,
1747                                     &activate_fs_download,
1748                                     &deactivate_fs_download,
1749                                     dc,
1750                                     (dc->length + DBLOCK_SIZE-1) / DBLOCK_SIZE);
1751 }
1752
1753
1754 /**
1755  * Stop a download (aborts if download is incomplete).
1756  *
1757  * @param dc handle for the download
1758  * @param do_delete delete files of incomplete downloads
1759  */
1760 void
1761 GNUNET_FS_download_stop (struct GNUNET_FS_DownloadContext *dc,
1762                          int do_delete)
1763 {
1764   struct GNUNET_FS_ProgressInfo pi;
1765   int have_children;
1766
1767   if (dc->top != NULL)
1768     GNUNET_FS_end_top (dc->h, dc->top);
1769   if (dc->search != NULL)
1770     {
1771       dc->search->download = NULL;
1772       dc->search = NULL;
1773     }
1774   if (dc->job_queue != NULL)
1775     {
1776       GNUNET_FS_dequeue_ (dc->job_queue);
1777       dc->job_queue = NULL;
1778     }
1779   have_children = (NULL != dc->child_head) ? GNUNET_YES : GNUNET_NO;
1780   while (NULL != dc->child_head)
1781     GNUNET_FS_download_stop (dc->child_head,
1782                              do_delete);
1783   if (dc->parent != NULL)
1784     GNUNET_CONTAINER_DLL_remove (dc->parent->child_head,
1785                                  dc->parent->child_tail,
1786                                  dc);
1787   if (dc->serialization != NULL)
1788     GNUNET_FS_remove_sync_file_ (dc->h,
1789                                  ( (dc->parent != NULL)  || (dc->search != NULL) )
1790                                  ? GNUNET_FS_SYNC_PATH_CHILD_DOWNLOAD
1791                                  : GNUNET_FS_SYNC_PATH_MASTER_DOWNLOAD ,
1792                                  dc->serialization);
1793   if ( (GNUNET_YES == have_children) &&
1794        (dc->parent == NULL) )
1795     GNUNET_FS_remove_sync_dir_ (dc->h,
1796                                 (dc->search != NULL)
1797                                 ? GNUNET_FS_SYNC_PATH_CHILD_DOWNLOAD
1798                                 : GNUNET_FS_SYNC_PATH_MASTER_DOWNLOAD,
1799                                 dc->serialization);
1800   pi.status = GNUNET_FS_STATUS_DOWNLOAD_STOPPED;
1801   GNUNET_FS_download_make_status_ (&pi, dc);
1802   if (GNUNET_SCHEDULER_NO_TASK != dc->task)
1803     GNUNET_SCHEDULER_cancel (dc->h->sched,
1804                              dc->task);
1805   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1806                                          &free_entry,
1807                                          NULL);
1808   GNUNET_CONTAINER_multihashmap_destroy (dc->active);
1809   if (dc->filename != NULL)
1810     {
1811       if ( (dc->completed != dc->length) &&
1812            (GNUNET_YES == do_delete) )
1813         {
1814           if (0 != UNLINK (dc->filename))
1815             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
1816                                       "unlink",
1817                                       dc->filename);
1818         }
1819       GNUNET_free (dc->filename);
1820     }
1821   GNUNET_CONTAINER_meta_data_destroy (dc->meta);
1822   GNUNET_FS_uri_destroy (dc->uri);
1823   if (NULL != dc->temp_filename)
1824     {
1825       if (0 != UNLINK (dc->temp_filename))
1826         GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
1827                                   "unlink",
1828                                   dc->temp_filename);
1829       GNUNET_free (dc->temp_filename);
1830     }
1831   GNUNET_free_non_null (dc->serialization);
1832   GNUNET_free (dc);
1833 }
1834
1835 /* end of fs_download.c */