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   pi->value.download.is_active = (dc->client == NULL) ? GNUNET_NO : GNUNET_YES;
 174   if (0 == (dc->options & GNUNET_FS_DOWNLOAD_IS_PROBE))
 175     dc->client_info = dc->h->upcb (dc->h->upcb_cls,
 176                                    pi);
 177   else
 178     dc->client_info = GNUNET_FS_search_probe_progress_ (NULL,
 179                                                         pi);
 180 }
 181
 182 /**
 183  * We're ready to transmit a search request to the
 184  * file-sharing service.  Do it.  If there is
 185  * more than one request pending, try to send
 186  * multiple or request another transmission.
 187  *
 188  * @param cls closure
 189  * @param size number of bytes available in buf
 190  * @param buf where the callee should write the message
 191  * @return number of bytes written to buf
 192  */
 193 static size_t
 194 transmit_download_request (void *cls,
 195                            size_t size,
 196                            void *buf);
 197
 198
 199 /**
 200  * Closure for iterator processing results.
 201  */
 202 struct ProcessResultClosure
 203 {
 204
 205   /**
 206    * Hash of data.
 207    */
 208   GNUNET_HashCode query;
 209
 210   /**
 211    * Data found in P2P network.
 212    */
 213   const void *data;
 214
 215   /**
 216    * Our download context.
 217    */
 218   struct GNUNET_FS_DownloadContext *dc;
 219
 220   /**
 221    * Number of bytes in data.
 222    */
 223   size_t size;
 224
 225   /**
 226    * Type of data.
 227    */
 228   enum GNUNET_BLOCK_Type type;
 229
 230   /**
 231    * Flag to indicate if this block should be stored on disk.
 232    */
 233   int do_store;
 234
 235 };
 236
 237
 238 /**
 239  * Iterator over entries in the pending requests in the 'active' map for the
 240  * reply that we just got.
 241  *
 242  * @param cls closure (our 'struct ProcessResultClosure')
 243  * @param key query for the given value / request
 244  * @param value value in the hash map (a 'struct DownloadRequest')
 245  * @return GNUNET_YES (we should continue to iterate); unless serious error
 246  */
 247 static int
 248 process_result_with_request (void *cls,
 249                              const GNUNET_HashCode * key,
 250                              void *value);
 251
 252
 253
 254 /**
 255  * Schedule the download of the specified block in the tree.
 256  *
 257  * @param dc overall download this block belongs to
 258  * @param chk content-hash-key of the block
 259  * @param offset offset of the block in the file
 260  *         (for IBlocks, the offset is the lowest
 261  *          offset of any DBlock in the subtree under
 262  *          the IBlock)
 263  * @param depth depth of the block, 0 is the root of the tree
 264  */
 265 static void
 266 schedule_block_download (struct GNUNET_FS_DownloadContext *dc,
 267                          const struct ContentHashKey *chk,
 268                          uint64_t offset,
 269                          unsigned int depth)
 270 {
 271   struct DownloadRequest *sm;
 272   uint64_t total;
 273   uint64_t off;
 274   size_t len;
 275   char block[DBLOCK_SIZE];
 276   GNUNET_HashCode key;
 277   struct ProcessResultClosure prc;
 278   struct GNUNET_DISK_FileHandle *fh;
 279
 280 #if DEBUG_DOWNLOAD
 281   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 282               "Scheduling download at offset %llu and depth %u for `%s'\n",
 283               (unsigned long long) offset,
 284               depth,
 285               GNUNET_h2s (&chk->query));
 286 #endif
 287   total = GNUNET_ntohll (dc->uri->data.chk.file_length);
 288   off = compute_disk_offset (total,
 289                              offset,
 290                              depth,
 291                              dc->treedepth);
 292   len = GNUNET_FS_tree_calculate_block_size (total,
 293                                              dc->treedepth,
 294                                              offset,
 295                                              depth);
 296   sm = GNUNET_malloc (sizeof (struct DownloadRequest));
 297   sm->chk = *chk;
 298   sm->offset = offset;
 299   sm->depth = depth;
 300   sm->is_pending = GNUNET_YES;
 301   sm->next = dc->pending;
 302   dc->pending = sm;
 303   GNUNET_CONTAINER_multihashmap_put (dc->active,
 304                                      &chk->query,
 305                                      sm,
 306                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
 307   fh = NULL;
 308   if ( (dc->old_file_size > off) &&
 309        (dc->filename != NULL) )
 310     fh = GNUNET_DISK_file_open (dc->filename,
 311                                 GNUNET_DISK_OPEN_READ,
 312                                 GNUNET_DISK_PERM_NONE);
 313   if ( (fh != NULL) &&
 314        (off  ==
 315         GNUNET_DISK_file_seek (fh,
 316                                off,
 317                                GNUNET_DISK_SEEK_SET) ) &&
 318        (len ==
 319         GNUNET_DISK_file_read (fh,
 320                                block,
 321                                len)) )
 322     {
 323       GNUNET_CRYPTO_hash (block, len, &key);
 324       if (0 == memcmp (&key,
 325                        &chk->key,
 326                        sizeof (GNUNET_HashCode)))
 327         {
 328           char enc[len];
 329           struct GNUNET_CRYPTO_AesSessionKey sk;
 330           struct GNUNET_CRYPTO_AesInitializationVector iv;
 331           GNUNET_HashCode query;
 332
 333           GNUNET_CRYPTO_hash_to_aes_key (&key, &sk, &iv);
 334           if (-1 == GNUNET_CRYPTO_aes_encrypt (block, len,
 335                                                &sk,
 336                                                &iv,
 337                                                enc))
 338             {
 339               GNUNET_break (0);
 340               goto do_download;
 341             }
 342           GNUNET_CRYPTO_hash (enc, len, &query);
 343           if (0 == memcmp (&query,
 344                            &chk->query,
 345                            sizeof (GNUNET_HashCode)))
 346             {
 347 #if DEBUG_DOWNLOAD
 348               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 349                           "Matching block already present, no need for download!\n");
 350 #endif
 351               /* already got it! */
 352               prc.dc = dc;
 353               prc.data = enc;
 354               prc.size = len;
 355               prc.type = (dc->treedepth == depth)
 356                 ? GNUNET_BLOCK_TYPE_DBLOCK
 357                 : GNUNET_BLOCK_TYPE_IBLOCK;
 358               prc.query = chk->query;
 359               prc.do_store = GNUNET_NO; /* useless */
 360               process_result_with_request (&prc,
 361                                            &key,
 362                                            sm);
 363             }
 364           else
 365             {
 366               GNUNET_break_op (0);
 367             }
 368           GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
 369           return;
 370         }
 371     }
 372  do_download:
 373   if (fh != NULL)
 374     GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
 375   if (depth < dc->treedepth)
 376     {
 377       // FIXME: try if we could
 378       // reconstitute this IBLOCK
 379       // from the existing blocks on disk (can wait)
 380       // (read block(s), encode, compare with
 381       // query; if matches, simply return)
 382     }
 383
 384   if ( (dc->th == NULL) &&
 385        (dc->client != NULL) )
 386     {
 387 #if DEBUG_DOWNLOAD
 388       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 389                   "Asking for transmission to FS service\n");
 390 #endif
 391       dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
 392                                                     sizeof (struct SearchMessage),
 393                                                     GNUNET_CONSTANTS_SERVICE_TIMEOUT,
 394                                                     GNUNET_NO,
 395                                                     &transmit_download_request,
 396                                                     dc);
 397     }
 398 }
 399
 400
 401
 402 /**
 403  * Suggest a filename based on given metadata.
 404  *
 405  * @param md given meta data
 406  * @return NULL if meta data is useless for suggesting a filename
 407  */
 408 char *
 409 GNUNET_FS_meta_data_suggest_filename (const struct GNUNET_CONTAINER_MetaData *md)
 410 {
 411   static const char *mimeMap[][2] = {
 412     {"application/bz2", ".bz2"},
 413     {"application/gnunet-directory", ".gnd"},
 414     {"application/java", ".class"},
 415     {"application/msword", ".doc"},
 416     {"application/ogg", ".ogg"},
 417     {"application/pdf", ".pdf"},
 418     {"application/pgp-keys", ".key"},
 419     {"application/pgp-signature", ".pgp"},
 420     {"application/postscript", ".ps"},
 421     {"application/rar", ".rar"},
 422     {"application/rtf", ".rtf"},
 423     {"application/xml", ".xml"},
 424     {"application/x-debian-package", ".deb"},
 425     {"application/x-dvi", ".dvi"},
 426     {"applixation/x-flac", ".flac"},
 427     {"applixation/x-gzip", ".gz"},
 428     {"application/x-java-archive", ".jar"},
 429     {"application/x-java-vm", ".class"},
 430     {"application/x-python-code", ".pyc"},
 431     {"application/x-redhat-package-manager", ".rpm"},
 432     {"application/x-rpm", ".rpm"},
 433     {"application/x-tar", ".tar"},
 434     {"application/x-tex-pk", ".pk"},
 435     {"application/x-texinfo", ".texinfo"},
 436     {"application/x-xcf", ".xcf"},
 437     {"application/x-xfig", ".xfig"},
 438     {"application/zip", ".zip"},
 439
 440     {"audio/midi", ".midi"},
 441     {"audio/mpeg", ".mp3"},
 442     {"audio/real", ".rm"},
 443     {"audio/x-wav", ".wav"},
 444
 445     {"image/gif", ".gif"},
 446     {"image/jpeg", ".jpg"},
 447     {"image/pcx", ".pcx"},
 448     {"image/png", ".png"},
 449     {"image/tiff", ".tiff"},
 450     {"image/x-ms-bmp", ".bmp"},
 451     {"image/x-xpixmap", ".xpm"},
 452
 453     {"text/css", ".css"},
 454     {"text/html", ".html"},
 455     {"text/plain", ".txt"},
 456     {"text/rtf", ".rtf"},
 457     {"text/x-c++hdr", ".h++"},
 458     {"text/x-c++src", ".c++"},
 459     {"text/x-chdr", ".h"},
 460     {"text/x-csrc", ".c"},
 461     {"text/x-java", ".java"},
 462     {"text/x-moc", ".moc"},
 463     {"text/x-pascal", ".pas"},
 464     {"text/x-perl", ".pl"},
 465     {"text/x-python", ".py"},
 466     {"text/x-tex", ".tex"},
 467
 468     {"video/avi", ".avi"},
 469     {"video/mpeg", ".mpeg"},
 470     {"video/quicktime", ".qt"},
 471     {"video/real", ".rm"},
 472     {"video/x-msvideo", ".avi"},
 473     {NULL, NULL},
 474   };
 475   char *ret;
 476   unsigned int i;
 477   char *mime;
 478   char *base;
 479   const char *ext;
 480
 481   ret = GNUNET_CONTAINER_meta_data_get_by_type (md,
 482                                                 EXTRACTOR_METATYPE_FILENAME);
 483   if (ret != NULL)
 484     return ret;
 485   ext = NULL;
 486   mime = GNUNET_CONTAINER_meta_data_get_by_type (md,
 487                                                  EXTRACTOR_METATYPE_MIMETYPE);
 488   if (mime != NULL)
 489     {
 490       i = 0;
 491       while ( (mimeMap[i][0] != NULL) &&
 492               (0 != strcmp (mime, mimeMap[i][0])))
 493         i++;
 494       if (mimeMap[i][1] == NULL)
 495         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG |
 496                     GNUNET_ERROR_TYPE_BULK,
 497                     _("Did not find mime type `%s' in extension list.\n"),
 498                     mime);
 499       else
 500         ext = mimeMap[i][1];
 501       GNUNET_free (mime);
 502     }
 503   base = GNUNET_CONTAINER_meta_data_get_first_by_types (md,
 504                                                         EXTRACTOR_METATYPE_TITLE,
 505                                                         EXTRACTOR_METATYPE_BOOK_TITLE,
 506                                                         EXTRACTOR_METATYPE_ORIGINAL_TITLE,
 507                                                         EXTRACTOR_METATYPE_PACKAGE_NAME,
 508                                                         EXTRACTOR_METATYPE_URL,
 509                                                         EXTRACTOR_METATYPE_URI,
 510                                                         EXTRACTOR_METATYPE_DESCRIPTION,
 511                                                         EXTRACTOR_METATYPE_ISRC,
 512                                                         EXTRACTOR_METATYPE_JOURNAL_NAME,
 513                                                         EXTRACTOR_METATYPE_AUTHOR_NAME,
 514                                                         EXTRACTOR_METATYPE_SUBJECT,
 515                                                         EXTRACTOR_METATYPE_ALBUM,
 516                                                         EXTRACTOR_METATYPE_ARTIST,
 517                                                         EXTRACTOR_METATYPE_KEYWORDS,
 518                                                         EXTRACTOR_METATYPE_COMMENT,
 519                                                         EXTRACTOR_METATYPE_UNKNOWN,
 520                                                         -1);
 521   if ( (base == NULL) &&
 522        (ext == NULL) )
 523     return NULL;
 524   if (base == NULL)
 525     return GNUNET_strdup (ext);
 526   if (ext == NULL)
 527     return base;
 528   GNUNET_asprintf (&ret,
 529                    "%s%s",
 530                    base,
 531                    ext);
 532   GNUNET_free (base);
 533   return ret;
 534 }
 535
 536
 537 /**
 538  * We've lost our connection with the FS service.
 539  * Re-establish it and re-transmit all of our
 540  * pending requests.
 541  *
 542  * @param dc download context that is having trouble
 543  */
 544 static void
 545 try_reconnect (struct GNUNET_FS_DownloadContext *dc);
 546
 547
 548 /**
 549  * We found an entry in a directory.  Check if the respective child
 550  * already exists and if not create the respective child download.
 551  *
 552  * @param cls the parent download
 553  * @param filename name of the file in the directory
 554  * @param uri URI of the file (CHK or LOC)
 555  * @param meta meta data of the file
 556  * @param length number of bytes in data
 557  * @param data contents of the file (or NULL if they were not inlined)
 558  */
 559 static void
 560 trigger_recursive_download (void *cls,
 561                             const char *filename,
 562                             const struct GNUNET_FS_Uri *uri,
 563                             const struct GNUNET_CONTAINER_MetaData *meta,
 564                             size_t length,
 565                             const void *data);
 566
 567
 568 /**
 569  * We're done downloading a directory.  Open the file and
 570  * trigger all of the (remaining) child downloads.
 571  *
 572  * @param dc context of download that just completed
 573  */
 574 static void
 575 full_recursive_download (struct GNUNET_FS_DownloadContext *dc)
 576 {
 577   size_t size;
 578   uint64_t size64;
 579   void *data;
 580   struct GNUNET_DISK_FileHandle *h;
 581   struct GNUNET_DISK_MapHandle *m;
 582
 583   size64 = GNUNET_FS_uri_chk_get_file_size (dc->uri);
 584   size = (size_t) size64;
 585   if (size64 != (uint64_t) size)
 586     {
 587       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 588                   _("Recursive downloads of directories larger than 4 GB are not supported on 32-bit systems\n"));
 589       return;
 590     }
 591   if (dc->filename != NULL)
 592     {
 593       h = GNUNET_DISK_file_open (dc->filename,
 594                                  GNUNET_DISK_OPEN_READ,
 595                                  GNUNET_DISK_PERM_NONE);
 596     }
 597   else
 598     {
 599       GNUNET_assert (dc->temp_filename != NULL);
 600       h = GNUNET_DISK_file_open (dc->temp_filename,
 601                                  GNUNET_DISK_OPEN_READ,
 602                                  GNUNET_DISK_PERM_NONE);
 603     }
 604   if (h == NULL)
 605     return; /* oops */
 606   data = GNUNET_DISK_file_map (h, &m, GNUNET_DISK_MAP_TYPE_READ, size);
 607   if (data == NULL)
 608     {
 609       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 610                   _("Directory too large for system address space\n"));
 611     }
 612   else
 613     {
 614       GNUNET_FS_directory_list_contents (size,
 615                                          data,
 616                                          0,
 617                                          &trigger_recursive_download,
 618                                          dc);
 619       GNUNET_DISK_file_unmap (m);
 620     }
 621   GNUNET_DISK_file_close (h);
 622   if (dc->filename == NULL)
 623     {
 624       if (0 != UNLINK (dc->temp_filename))
 625         GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
 626                                   "unlink",
 627                                   dc->temp_filename);
 628       GNUNET_free (dc->temp_filename);
 629       dc->temp_filename = NULL;
 630     }
 631 }
 632
 633
 634 /**
 635  * Check if all child-downloads have completed and
 636  * if so, signal completion (and possibly recurse to
 637  * parent).
 638  */
 639 static void
 640 check_completed (struct GNUNET_FS_DownloadContext *dc)
 641 {
 642   struct GNUNET_FS_ProgressInfo pi;
 643   struct GNUNET_FS_DownloadContext *pos;
 644
 645   pos = dc->child_head;
 646   while (pos != NULL)
 647     {
 648       if ( (pos->emsg == NULL) &&
 649            (pos->completed < pos->length) )
 650         return; /* not done yet */
 651       if ( (pos->child_head != NULL) &&
 652            (pos->has_finished != GNUNET_YES) )
 653         return; /* not transitively done yet */
 654       pos = pos->next;
 655     }
 656   dc->has_finished = GNUNET_YES;
 657   GNUNET_FS_download_sync_ (dc);
 658   /* signal completion */
 659   pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
 660   GNUNET_FS_download_make_status_ (&pi, dc);
 661   if (dc->parent != NULL)
 662     check_completed (dc->parent);
 663 }
 664
 665
 666 /**
 667  * We found an entry in a directory.  Check if the respective child
 668  * already exists and if not create the respective child download.
 669  *
 670  * @param cls the parent download
 671  * @param filename name of the file in the directory
 672  * @param uri URI of the file (CHK or LOC)
 673  * @param meta meta data of the file
 674  * @param length number of bytes in data
 675  * @param data contents of the file (or NULL if they were not inlined)
 676  */
 677 static void
 678 trigger_recursive_download (void *cls,
 679                             const char *filename,
 680                             const struct GNUNET_FS_Uri *uri,
 681                             const struct GNUNET_CONTAINER_MetaData *meta,
 682                             size_t length,
 683                             const void *data)
 684 {
 685   struct GNUNET_FS_DownloadContext *dc = cls;
 686   struct GNUNET_FS_DownloadContext *cpos;
 687   struct GNUNET_DISK_FileHandle *fh;
 688   char *temp_name;
 689   const char *real_name;
 690   char *fn;
 691   char *us;
 692   char *ext;
 693   char *dn;
 694   char *full_name;
 695
 696   if (NULL == uri)
 697     return; /* entry for the directory itself */
 698   cpos = dc->child_head;
 699   while (cpos != NULL)
 700     {
 701       if ( (GNUNET_FS_uri_test_equal (uri,
 702                                       cpos->uri)) ||
 703            ( (filename != NULL) &&
 704              (0 == strcmp (cpos->filename,
 705                            filename)) ) )
 706         break;
 707       cpos = cpos->next;
 708     }
 709   if (cpos != NULL)
 710     return; /* already exists */
 711   fn = NULL;
 712   if (NULL == filename)
 713     {
 714       fn = GNUNET_FS_meta_data_suggest_filename (meta);
 715       if (fn == NULL)
 716         {
 717           us = GNUNET_FS_uri_to_string (uri);
 718           fn = GNUNET_strdup (&us [strlen (GNUNET_FS_URI_PREFIX
 719                                            GNUNET_FS_URI_CHK_INFIX)]);
 720           GNUNET_free (us);
 721         }
 722       else if (fn[0] == '.')
 723         {
 724           ext = fn;
 725           us = GNUNET_FS_uri_to_string (uri);
 726           GNUNET_asprintf (&fn,
 727                            "%s%s",
 728                            &us[strlen (GNUNET_FS_URI_PREFIX
 729                                        GNUNET_FS_URI_CHK_INFIX)], ext);
 730           GNUNET_free (ext);
 731           GNUNET_free (us);
 732         }
 733       filename = fn;
 734     }
 735   if (dc->filename == NULL)
 736     {
 737       full_name = NULL;
 738     }
 739   else
 740     {
 741       dn = GNUNET_strdup (dc->filename);
 742       GNUNET_break ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
 743                      (NULL !=
 744                       strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
 745                               GNUNET_FS_DIRECTORY_EXT)) );
 746       if ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
 747            (NULL !=
 748             strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
 749                     GNUNET_FS_DIRECTORY_EXT)) )
 750         dn[strlen(dn) - strlen (GNUNET_FS_DIRECTORY_EXT)] = '\0';
 751       if ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (meta)) &&
 752            ( (strlen (filename) < strlen (GNUNET_FS_DIRECTORY_EXT)) ||
 753              (NULL ==
 754               strstr (filename + strlen(filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
 755                       GNUNET_FS_DIRECTORY_EXT)) ) )
 756         {
 757           GNUNET_asprintf (&full_name,
 758                            "%s%s%s%s",
 759                            dn,
 760                            DIR_SEPARATOR_STR,
 761                            filename,
 762                            GNUNET_FS_DIRECTORY_EXT);
 763         }
 764       else
 765         {
 766           GNUNET_asprintf (&full_name,
 767                            "%s%s%s",
 768                            dn,
 769                            DIR_SEPARATOR_STR,
 770                            filename);
 771         }
 772       GNUNET_free (dn);
 773     }
 774   if ( (full_name != NULL) &&
 775        (GNUNET_OK !=
 776         GNUNET_DISK_directory_create_for_file (full_name)) )
 777     {
 778       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 779                   _("Failed to create directory for recursive download of `%s'\n"),
 780                   full_name);
 781       GNUNET_free (full_name);
 782       GNUNET_free_non_null (fn);
 783       return;
 784     }
 785
 786   temp_name = NULL;
 787   if ( (data != NULL) &&
 788        (GNUNET_FS_uri_chk_get_file_size (uri) == length) )
 789     {
 790       if (full_name == NULL)
 791         {
 792           temp_name = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
 793           real_name = temp_name;
 794         }
 795       else
 796         {
 797           real_name = full_name;
 798         }
 799       /* write to disk, then trigger normal download which will instantly progress to completion */
 800       fh = GNUNET_DISK_file_open (real_name,
 801                                   GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_TRUNCATE | GNUNET_DISK_OPEN_CREATE,
 802                                   GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE);
 803       if (fh == NULL)
 804         {
 805           GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
 806                                     "open",
 807                                     real_name);
 808           GNUNET_free (full_name);
 809           GNUNET_free_non_null (fn);
 810           return;
 811         }
 812       if (length !=
 813           GNUNET_DISK_file_write (fh,
 814                                   data,
 815                                   length))
 816         {
 817           GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
 818                                     "write",
 819                                     full_name);
 820         }
 821       GNUNET_DISK_file_close (fh);
 822     }
 823   GNUNET_FS_download_start (dc->h,
 824                             uri,
 825                             meta,
 826                             full_name, temp_name,
 827                             0,
 828                             GNUNET_FS_uri_chk_get_file_size (uri),
 829                             dc->anonymity,
 830                             dc->options,
 831                             NULL,
 832                             dc);
 833   GNUNET_free_non_null (full_name);
 834   GNUNET_free_non_null (temp_name);
 835   GNUNET_free_non_null (fn);
 836 }
 837
 838
 839 /**
 840  * Free entries in the map.
 841  *
 842  * @param cls unused (NULL)
 843  * @param key unused
 844  * @param entry entry of type "struct DownloadRequest" which is freed
 845  * @return GNUNET_OK
 846  */
 847 static int
 848 free_entry (void *cls,
 849             const GNUNET_HashCode *key,
 850             void *entry)
 851 {
 852   GNUNET_free (entry);
 853   return GNUNET_OK;
 854 }
 855
 856
 857 /**
 858  * Iterator over entries in the pending requests in the 'active' map for the
 859  * reply that we just got.
 860  *
 861  * @param cls closure (our 'struct ProcessResultClosure')
 862  * @param key query for the given value / request
 863  * @param value value in the hash map (a 'struct DownloadRequest')
 864  * @return GNUNET_YES (we should continue to iterate); unless serious error
 865  */
 866 static int
 867 process_result_with_request (void *cls,
 868                              const GNUNET_HashCode * key,
 869                              void *value)
 870 {
 871   struct ProcessResultClosure *prc = cls;
 872   struct DownloadRequest *sm = value;
 873   struct DownloadRequest *ppos;
 874   struct DownloadRequest *pprev;
 875   struct GNUNET_DISK_FileHandle *fh;
 876   struct GNUNET_FS_DownloadContext *dc = prc->dc;
 877   struct GNUNET_CRYPTO_AesSessionKey skey;
 878   struct GNUNET_CRYPTO_AesInitializationVector iv;
 879   char pt[prc->size];
 880   struct GNUNET_FS_ProgressInfo pi;
 881   uint64_t off;
 882   size_t bs;
 883   size_t app;
 884   int i;
 885   struct ContentHashKey *chk;
 886
 887   fh = NULL;
 888   bs = GNUNET_FS_tree_calculate_block_size (GNUNET_ntohll (dc->uri->data.chk.file_length),
 889                                             dc->treedepth,
 890                                             sm->offset,
 891                                             sm->depth);
 892   if (prc->size != bs)
 893     {
 894 #if DEBUG_DOWNLOAD
 895       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 896                   "Internal error or bogus download URI (expected %u bytes, got %u)\n",
 897                   bs,
 898                   prc->size);
 899 #endif
 900       dc->emsg = GNUNET_strdup ("Internal error or bogus download URI");
 901       goto signal_error;
 902     }
 903   GNUNET_assert (GNUNET_YES ==
 904                  GNUNET_CONTAINER_multihashmap_remove (dc->active,
 905                                                        &prc->query,
 906                                                        sm));
 907   /* if this request is on the pending list, remove it! */
 908   pprev = NULL;
 909   ppos = dc->pending;
 910   while (ppos != NULL)
 911     {
 912       if (ppos == sm)
 913         {
 914           if (pprev == NULL)
 915             dc->pending = ppos->next;
 916           else
 917             pprev->next = ppos->next;
 918           break;
 919         }
 920       pprev = ppos;
 921       ppos = ppos->next;
 922     }
 923   GNUNET_CRYPTO_hash_to_aes_key (&sm->chk.key, &skey, &iv);
 924   if (-1 == GNUNET_CRYPTO_aes_decrypt (prc->data,
 925                                        prc->size,
 926                                        &skey,
 927                                        &iv,
 928                                        pt))
 929     {
 930       GNUNET_break (0);
 931       dc->emsg = GNUNET_strdup ("internal error decrypting content");
 932       goto signal_error;
 933     }
 934   off = compute_disk_offset (GNUNET_ntohll (dc->uri->data.chk.file_length),
 935                              sm->offset,
 936                              sm->depth,
 937                              dc->treedepth);
 938   /* save to disk */
 939   if ( ( GNUNET_YES == prc->do_store) &&
 940        ( (dc->filename != NULL) ||
 941          (is_recursive_download (dc)) ) &&
 942        ( (sm->depth == dc->treedepth) ||
 943          (0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES)) ) )
 944     {
 945       fh = GNUNET_DISK_file_open (dc->filename != NULL
 946                                   ? dc->filename
 947                                   : dc->temp_filename,
 948                                   GNUNET_DISK_OPEN_READWRITE |
 949                                   GNUNET_DISK_OPEN_CREATE,
 950                                   GNUNET_DISK_PERM_USER_READ |
 951                                   GNUNET_DISK_PERM_USER_WRITE |
 952                                   GNUNET_DISK_PERM_GROUP_READ |
 953                                   GNUNET_DISK_PERM_OTHER_READ);
 954     }
 955   if ( (NULL == fh) &&
 956        (GNUNET_YES == prc->do_store) &&
 957        ( (dc->filename != NULL) ||
 958          (is_recursive_download (dc)) ) &&
 959        ( (sm->depth == dc->treedepth) ||
 960          (0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES)) ) )
 961     {
 962       GNUNET_asprintf (&dc->emsg,
 963                        _("Download failed: could not open file `%s': %s\n"),
 964                        dc->filename,
 965                        STRERROR (errno));
 966       goto signal_error;
 967     }
 968   if (fh != NULL)
 969     {
 970 #if DEBUG_DOWNLOAD
 971       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 972                   "Saving decrypted block to disk at offset %llu\n",
 973                   (unsigned long long) off);
 974 #endif
 975       if ( (off  !=
 976             GNUNET_DISK_file_seek (fh,
 977                                    off,
 978                                    GNUNET_DISK_SEEK_SET) ) )
 979         {
 980           GNUNET_asprintf (&dc->emsg,
 981                            _("Failed to seek to offset %llu in file `%s': %s\n"),
 982                            (unsigned long long) off,
 983                            dc->filename,
 984                            STRERROR (errno));
 985           goto signal_error;
 986         }
 987       if (prc->size !=
 988           GNUNET_DISK_file_write (fh,
 989                                   pt,
 990                                   prc->size))
 991         {
 992           GNUNET_asprintf (&dc->emsg,
 993                            _("Failed to write block of %u bytes at offset %llu in file `%s': %s\n"),
 994                            (unsigned int) prc->size,
 995                            (unsigned long long) off,
 996                            dc->filename,
 997                            STRERROR (errno));
 998           goto signal_error;
 999         }
1000       GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
1001       fh = NULL;
1002     }
1003   if (sm->depth == dc->treedepth)
1004     {
1005       app = prc->size;
1006       if (sm->offset < dc->offset)
1007         {
1008           /* starting offset begins in the middle of pt,
1009              do not count first bytes as progress */
1010           GNUNET_assert (app > (dc->offset - sm->offset));
1011           app -= (dc->offset - sm->offset);
1012         }
1013       if (sm->offset + prc->size > dc->offset + dc->length)
1014         {
1015           /* end of block is after relevant range,
1016              do not count last bytes as progress */
1017           GNUNET_assert (app > (sm->offset + prc->size) - (dc->offset + dc->length));
1018           app -= (sm->offset + prc->size) - (dc->offset + dc->length);
1019         }
1020       dc->completed += app;
1021
1022       /* do recursive download if option is set and either meta data
1023          says it is a directory or if no meta data is given AND filename
1024          ends in '.gnd' (top-level case) */
1025       if (is_recursive_download (dc))
1026         GNUNET_FS_directory_list_contents (prc->size,
1027                                            pt,
1028                                            off,
1029                                            &trigger_recursive_download,
1030                                            dc);
1031
1032     }
1033   pi.status = GNUNET_FS_STATUS_DOWNLOAD_PROGRESS;
1034   pi.value.download.specifics.progress.data = pt;
1035   pi.value.download.specifics.progress.offset = sm->offset;
1036   pi.value.download.specifics.progress.data_len = prc->size;
1037   pi.value.download.specifics.progress.depth = sm->depth;
1038   GNUNET_FS_download_make_status_ (&pi, dc);
1039   GNUNET_assert (dc->completed <= dc->length);
1040   if (dc->completed == dc->length)
1041     {
1042 #if DEBUG_DOWNLOAD
1043       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1044                   "Download completed, truncating file to desired length %llu\n",
1045                   (unsigned long long) GNUNET_ntohll (dc->uri->data.chk.file_length));
1046 #endif
1047       /* truncate file to size (since we store IBlocks at the end) */
1048       if (dc->filename != NULL)
1049         {
1050           if (0 != truncate (dc->filename,
1051                              GNUNET_ntohll (dc->uri->data.chk.file_length)))
1052             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
1053                                       "truncate",
1054                                       dc->filename);
1055         }
1056       if (dc->job_queue != NULL)
1057         {
1058           GNUNET_FS_dequeue_ (dc->job_queue);
1059           dc->job_queue = NULL;
1060         }
1061       if (is_recursive_download (dc))
1062         full_recursive_download (dc);
1063       if (dc->child_head == NULL)
1064         {
1065           /* signal completion */
1066           pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
1067           GNUNET_FS_download_make_status_ (&pi, dc);
1068           if (dc->parent != NULL)
1069             check_completed (dc->parent);
1070         }
1071       GNUNET_assert (sm->depth == dc->treedepth);
1072     }
1073   if (sm->depth == dc->treedepth)
1074     {
1075       GNUNET_FS_download_sync_ (dc);
1076       GNUNET_free (sm);
1077       return GNUNET_YES;
1078     }
1079 #if DEBUG_DOWNLOAD
1080   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1081               "Triggering downloads of children (this block was at depth %u and offset %llu)\n",
1082               sm->depth,
1083               (unsigned long long) sm->offset);
1084 #endif
1085   GNUNET_assert (0 == (prc->size % sizeof(struct ContentHashKey)));
1086   chk = (struct ContentHashKey*) pt;
1087   for (i=(prc->size / sizeof(struct ContentHashKey))-1;i>=0;i--)
1088     {
1089       off = compute_dblock_offset (sm->offset,
1090                                    sm->depth,
1091                                    dc->treedepth,
1092                                    i);
1093       if ( (off + DBLOCK_SIZE >= dc->offset) &&
1094            (off < dc->offset + dc->length) )
1095         schedule_block_download (dc,
1096                                  &chk[i],
1097                                  off,
1098                                  sm->depth + 1);
1099     }
1100   GNUNET_free (sm);
1101   GNUNET_FS_download_sync_ (dc);
1102   return GNUNET_YES;
1103
1104  signal_error:
1105   if (fh != NULL)
1106     GNUNET_DISK_file_close (fh);
1107   pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
1108   pi.value.download.specifics.error.message = dc->emsg;
1109   GNUNET_FS_download_make_status_ (&pi, dc);
1110   /* abort all pending requests */
1111   if (NULL != dc->th)
1112     {
1113       GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1114       dc->th = NULL;
1115     }
1116   GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1117   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1118                                          &free_entry,
1119                                          NULL);
1120   dc->pending = NULL;
1121   dc->client = NULL;
1122   GNUNET_free (sm);
1123   GNUNET_FS_download_sync_ (dc);
1124   return GNUNET_NO;
1125 }
1126
1127
1128 /**
1129  * Process a download result.
1130  *
1131  * @param dc our download context
1132  * @param type type of the result
1133  * @param data the (encrypted) response
1134  * @param size size of data
1135  */
1136 static void
1137 process_result (struct GNUNET_FS_DownloadContext *dc,
1138                 enum GNUNET_BLOCK_Type type,
1139                 const void *data,
1140                 size_t size)
1141 {
1142   struct ProcessResultClosure prc;
1143
1144   prc.dc = dc;
1145   prc.data = data;
1146   prc.size = size;
1147   prc.type = type;
1148   prc.do_store = GNUNET_YES;
1149   GNUNET_CRYPTO_hash (data, size, &prc.query);
1150 #if DEBUG_DOWNLOAD
1151   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1152               "Received result for query `%s' from `%s'-service\n",
1153               GNUNET_h2s (&prc.query),
1154               "FS");
1155 #endif
1156   GNUNET_CONTAINER_multihashmap_get_multiple (dc->active,
1157                                               &prc.query,
1158                                               &process_result_with_request,
1159                                               &prc);
1160 }
1161
1162
1163 /**
1164  * Type of a function to call when we receive a message
1165  * from the service.
1166  *
1167  * @param cls closure
1168  * @param msg message received, NULL on timeout or fatal error
1169  */
1170 static void
1171 receive_results (void *cls,
1172                  const struct GNUNET_MessageHeader * msg)
1173 {
1174   struct GNUNET_FS_DownloadContext *dc = cls;
1175   const struct PutMessage *cm;
1176   uint16_t msize;
1177
1178   if ( (NULL == msg) ||
1179        (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_FS_PUT) ||
1180        (sizeof (struct PutMessage) > ntohs(msg->size)) )
1181     {
1182       GNUNET_break (msg == NULL);
1183       try_reconnect (dc);
1184       return;
1185     }
1186   msize = ntohs(msg->size);
1187   cm = (const struct PutMessage*) msg;
1188   process_result (dc,
1189                   ntohl (cm->type),
1190                   &cm[1],
1191                   msize - sizeof (struct PutMessage));
1192   if (dc->client == NULL)
1193     return; /* fatal error */
1194   /* continue receiving */
1195   GNUNET_CLIENT_receive (dc->client,
1196                          &receive_results,
1197                          dc,
1198                          GNUNET_TIME_UNIT_FOREVER_REL);
1199 }
1200
1201
1202
1203 /**
1204  * We're ready to transmit a search request to the
1205  * file-sharing service.  Do it.  If there is
1206  * more than one request pending, try to send
1207  * multiple or request another transmission.
1208  *
1209  * @param cls closure
1210  * @param size number of bytes available in buf
1211  * @param buf where the callee should write the message
1212  * @return number of bytes written to buf
1213  */
1214 static size_t
1215 transmit_download_request (void *cls,
1216                            size_t size,
1217                            void *buf)
1218 {
1219   struct GNUNET_FS_DownloadContext *dc = cls;
1220   size_t msize;
1221   struct SearchMessage *sm;
1222
1223   dc->th = NULL;
1224   if (NULL == buf)
1225     {
1226 #if DEBUG_DOWNLOAD
1227       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1228                   "Transmitting download request failed, trying to reconnect\n");
1229 #endif
1230       try_reconnect (dc);
1231       return 0;
1232     }
1233   GNUNET_assert (size >= sizeof (struct SearchMessage));
1234   msize = 0;
1235   sm = buf;
1236   while ( (dc->pending != NULL) &&
1237           (size > msize + sizeof (struct SearchMessage)) )
1238     {
1239 #if DEBUG_DOWNLOAD
1240       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1241                   "Transmitting download request for `%s' to `%s'-service\n",
1242                   GNUNET_h2s (&dc->pending->chk.query),
1243                   "FS");
1244 #endif
1245       memset (sm, 0, sizeof (struct SearchMessage));
1246       sm->header.size = htons (sizeof (struct SearchMessage));
1247       sm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_START_SEARCH);
1248       if (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_LOOPBACK_ONLY))
1249         sm->options = htonl (1);
1250       else
1251         sm->options = htonl (0);
1252       if (dc->pending->depth == dc->treedepth)
1253         sm->type = htonl (GNUNET_BLOCK_TYPE_DBLOCK);
1254       else
1255         sm->type = htonl (GNUNET_BLOCK_TYPE_IBLOCK);
1256       sm->anonymity_level = htonl (dc->anonymity);
1257       sm->target = dc->target.hashPubKey;
1258       sm->query = dc->pending->chk.query;
1259       dc->pending->is_pending = GNUNET_NO;
1260       dc->pending = dc->pending->next;
1261       msize += sizeof (struct SearchMessage);
1262       sm++;
1263     }
1264   if (dc->pending != NULL)
1265     dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
1266                                                   sizeof (struct SearchMessage),
1267                                                   GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1268                                                   GNUNET_NO,
1269                                                   &transmit_download_request,
1270                                                   dc);
1271   return msize;
1272 }
1273
1274
1275 /**
1276  * Reconnect to the FS service and transmit our queries NOW.
1277  *
1278  * @param cls our download context
1279  * @param tc unused
1280  */
1281 static void
1282 do_reconnect (void *cls,
1283               const struct GNUNET_SCHEDULER_TaskContext *tc)
1284 {
1285   struct GNUNET_FS_DownloadContext *dc = cls;
1286   struct GNUNET_CLIENT_Connection *client;
1287
1288   dc->task = GNUNET_SCHEDULER_NO_TASK;
1289   client = GNUNET_CLIENT_connect (dc->h->sched,
1290                                   "fs",
1291                                   dc->h->cfg);
1292   if (NULL == client)
1293     {
1294       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1295                   "Connecting to `%s'-service failed, will try again.\n",
1296                   "FS");
1297       try_reconnect (dc);
1298       return;
1299     }
1300   dc->client = client;
1301   dc->th = GNUNET_CLIENT_notify_transmit_ready (client,
1302                                                 sizeof (struct SearchMessage),
1303                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1304                                                 GNUNET_NO,
1305                                                 &transmit_download_request,
1306                                                 dc);
1307   GNUNET_CLIENT_receive (client,
1308                          &receive_results,
1309                          dc,
1310                          GNUNET_TIME_UNIT_FOREVER_REL);
1311 }
1312
1313
1314 /**
1315  * Add entries that are not yet pending back to the pending list.
1316  *
1317  * @param cls our download context
1318  * @param key unused
1319  * @param entry entry of type "struct DownloadRequest"
1320  * @return GNUNET_OK
1321  */
1322 static int
1323 retry_entry (void *cls,
1324              const GNUNET_HashCode *key,
1325              void *entry)
1326 {
1327   struct GNUNET_FS_DownloadContext *dc = cls;
1328   struct DownloadRequest *dr = entry;
1329
1330   if (! dr->is_pending)
1331     {
1332       dr->next = dc->pending;
1333       dr->is_pending = GNUNET_YES;
1334       dc->pending = entry;
1335     }
1336   return GNUNET_OK;
1337 }
1338
1339
1340 /**
1341  * We've lost our connection with the FS service.
1342  * Re-establish it and re-transmit all of our
1343  * pending requests.
1344  *
1345  * @param dc download context that is having trouble
1346  */
1347 static void
1348 try_reconnect (struct GNUNET_FS_DownloadContext *dc)
1349 {
1350
1351   if (NULL != dc->client)
1352     {
1353 #if DEBUG_DOWNLOAD
1354       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1355                   "Moving all requests back to pending list\n");
1356 #endif
1357       if (NULL != dc->th)
1358         {
1359           GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1360           dc->th = NULL;
1361         }
1362       GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1363                                              &retry_entry,
1364                                              dc);
1365       GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1366       dc->client = NULL;
1367     }
1368 #if DEBUG_DOWNLOAD
1369   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1370               "Will try to reconnect in 1s\n");
1371 #endif
1372   dc->task
1373     = GNUNET_SCHEDULER_add_delayed (dc->h->sched,
1374                                     GNUNET_TIME_UNIT_SECONDS,
1375                                     &do_reconnect,
1376                                     dc);
1377 }
1378
1379
1380
1381 /**
1382  * We're allowed to ask the FS service for our blocks.  Start the download.
1383  *
1384  * @param cls the 'struct GNUNET_FS_DownloadContext'
1385  * @param client handle to use for communcation with FS (we must destroy it!)
1386  */
1387 static void
1388 activate_fs_download (void *cls,
1389                       struct GNUNET_CLIENT_Connection *client)
1390 {
1391   struct GNUNET_FS_DownloadContext *dc = cls;
1392   struct GNUNET_FS_ProgressInfo pi;
1393
1394   GNUNET_assert (NULL != client);
1395   GNUNET_assert (dc->client == NULL);
1396   GNUNET_assert (dc->th == NULL);
1397   dc->client = client;
1398   GNUNET_CLIENT_receive (client,
1399                          &receive_results,
1400                          dc,
1401                          GNUNET_TIME_UNIT_FOREVER_REL);
1402   pi.status = GNUNET_FS_STATUS_DOWNLOAD_ACTIVE;
1403   GNUNET_FS_download_make_status_ (&pi, dc);
1404   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1405                                          &retry_entry,
1406                                          dc);
1407   dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
1408                                                 sizeof (struct SearchMessage),
1409                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
1410                                                 GNUNET_NO,
1411                                                 &transmit_download_request,
1412                                                 dc);
1413 }
1414
1415
1416 /**
1417  * We must stop to ask the FS service for our blocks.  Pause the download.
1418  *
1419  * @param cls the 'struct GNUNET_FS_DownloadContext'
1420  */
1421 static void
1422 deactivate_fs_download (void *cls)
1423 {
1424   struct GNUNET_FS_DownloadContext *dc = cls;
1425   struct GNUNET_FS_ProgressInfo pi;
1426
1427   if (NULL != dc->th)
1428     {
1429       GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
1430       dc->th = NULL;
1431     }
1432   if (NULL != dc->client)
1433     {
1434       GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
1435       dc->client = NULL;
1436     }
1437   pi.status = GNUNET_FS_STATUS_DOWNLOAD_INACTIVE;
1438   GNUNET_FS_download_make_status_ (&pi, dc);
1439 }
1440
1441
1442 /**
1443  * Create SUSPEND event for the given download operation
1444  * and then clean up our state (without stop signal).
1445  *
1446  * @param cls the 'struct GNUNET_FS_DownloadContext' to signal for
1447  */
1448 void
1449 GNUNET_FS_download_signal_suspend_ (void *cls)
1450 {
1451   struct GNUNET_FS_DownloadContext *dc = cls;
1452   struct GNUNET_FS_ProgressInfo pi;
1453
1454   if (dc->top != NULL)
1455     GNUNET_FS_end_top (dc->h, dc->top);
1456   while (NULL != dc->child_head)
1457     GNUNET_FS_download_signal_suspend_ (dc->child_head);
1458   if (dc->search != NULL)
1459     {
1460       dc->search->download = NULL;
1461       dc->search = NULL;
1462     }
1463   if (dc->job_queue != NULL)
1464     {
1465       GNUNET_FS_dequeue_ (dc->job_queue);
1466       dc->job_queue = NULL;
1467     }
1468   if (dc->parent != NULL)
1469     GNUNET_CONTAINER_DLL_remove (dc->parent->child_head,
1470                                  dc->parent->child_tail,
1471                                  dc);
1472   pi.status = GNUNET_FS_STATUS_DOWNLOAD_SUSPEND;
1473   GNUNET_FS_download_make_status_ (&pi, dc);
1474   if (GNUNET_SCHEDULER_NO_TASK != dc->task)
1475     GNUNET_SCHEDULER_cancel (dc->h->sched,
1476                              dc->task);
1477   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1478                                          &free_entry,
1479                                          NULL);
1480   GNUNET_CONTAINER_multihashmap_destroy (dc->active);
1481   GNUNET_free_non_null (dc->filename);
1482   GNUNET_CONTAINER_meta_data_destroy (dc->meta);
1483   GNUNET_FS_uri_destroy (dc->uri);
1484   GNUNET_free_non_null (dc->temp_filename);
1485   GNUNET_free_non_null (dc->serialization);
1486   GNUNET_free (dc);
1487 }
1488
1489
1490 /**
1491  * Download parts of a file.  Note that this will store
1492  * the blocks at the respective offset in the given file.  Also, the
1493  * download is still using the blocking of the underlying FS
1494  * encoding.  As a result, the download may *write* outside of the
1495  * given boundaries (if offset and length do not match the 32k FS
1496  * block boundaries). <p>
1497  *
1498  * This function should be used to focus a download towards a
1499  * particular portion of the file (optimization), not to strictly
1500  * limit the download to exactly those bytes.
1501  *
1502  * @param h handle to the file sharing subsystem
1503  * @param uri the URI of the file (determines what to download); CHK or LOC URI
1504  * @param meta known metadata for the file (can be NULL)
1505  * @param filename where to store the file, maybe NULL (then no file is
1506  *        created on disk and data must be grabbed from the callbacks)
1507  * @param tempname where to store temporary file data, not used if filename is non-NULL;
1508  *        can be NULL (in which case we will pick a name if needed); the temporary file
1509  *        may already exist, in which case we will try to use the data that is there and
1510  *        if it is not what is desired, will overwrite it
1511  * @param offset at what offset should we start the download (typically 0)
1512  * @param length how many bytes should be downloaded starting at offset
1513  * @param anonymity anonymity level to use for the download
1514  * @param options various options
1515  * @param cctx initial value for the client context for this download
1516  * @param parent parent download to associate this download with (use NULL
1517  *        for top-level downloads; useful for manually-triggered recursive downloads)
1518  * @return context that can be used to control this download
1519  */
1520 struct GNUNET_FS_DownloadContext *
1521 GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
1522                           const struct GNUNET_FS_Uri *uri,
1523                           const struct GNUNET_CONTAINER_MetaData *meta,
1524                           const char *filename,
1525                           const char *tempname,
1526                           uint64_t offset,
1527                           uint64_t length,
1528                           uint32_t anonymity,
1529                           enum GNUNET_FS_DownloadOptions options,
1530                           void *cctx,
1531                           struct GNUNET_FS_DownloadContext *parent)
1532 {
1533   struct GNUNET_FS_ProgressInfo pi;
1534   struct GNUNET_FS_DownloadContext *dc;
1535
1536   GNUNET_assert (GNUNET_FS_uri_test_chk (uri));
1537   if ( (offset + length < offset) ||
1538        (offset + length > uri->data.chk.file_length) )
1539     {
1540       GNUNET_break (0);
1541       return NULL;
1542     }
1543 #if DEBUG_DOWNLOAD
1544   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1545               "Starting download `%s' of %llu bytes\n",
1546               filename,
1547               (unsigned long long) length);
1548 #endif
1549   dc = GNUNET_malloc (sizeof(struct GNUNET_FS_DownloadContext));
1550   dc->h = h;
1551   dc->parent = parent;
1552   if (parent != NULL)
1553     {
1554       GNUNET_CONTAINER_DLL_insert (parent->child_head,
1555                                    parent->child_tail,
1556                                    dc);
1557     }
1558   dc->uri = GNUNET_FS_uri_dup (uri);
1559   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (meta);
1560   dc->client_info = cctx;
1561   dc->start_time = GNUNET_TIME_absolute_get ();
1562   if (NULL != filename)
1563     {
1564       dc->filename = GNUNET_strdup (filename);
1565       if (GNUNET_YES == GNUNET_DISK_file_test (filename))
1566         GNUNET_DISK_file_size (filename,
1567                                &dc->old_file_size,
1568                                GNUNET_YES);
1569     }
1570   if (GNUNET_FS_uri_test_loc (dc->uri))
1571     GNUNET_assert (GNUNET_OK ==
1572                    GNUNET_FS_uri_loc_get_peer_identity (dc->uri,
1573                                                         &dc->target));
1574   dc->offset = offset;
1575   dc->length = length;
1576   dc->anonymity = anonymity;
1577   dc->options = options;
1578   dc->active = GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
1579   dc->treedepth = GNUNET_FS_compute_depth (GNUNET_ntohll(dc->uri->data.chk.file_length));
1580   if ( (filename == NULL) &&
1581        (is_recursive_download (dc) ) )
1582     {
1583       if (tempname != NULL)
1584         dc->temp_filename = GNUNET_strdup (tempname);
1585       else
1586         dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
1587     }
1588
1589 #if DEBUG_DOWNLOAD
1590   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1591               "Download tree has depth %u\n",
1592               dc->treedepth);
1593 #endif
1594   if (parent == NULL)
1595     {
1596       dc->top = GNUNET_FS_make_top (dc->h,
1597                                     &GNUNET_FS_download_signal_suspend_,
1598                                     dc);
1599     }
1600   pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
1601   pi.value.download.specifics.start.meta = meta;
1602   GNUNET_FS_download_make_status_ (&pi, dc);
1603   schedule_block_download (dc,
1604                            &dc->uri->data.chk.chk,
1605                            0,
1606                            1 /* 0 == CHK, 1 == top */);
1607   GNUNET_FS_download_sync_ (dc);
1608   GNUNET_FS_download_start_downloading_ (dc);
1609   return dc;
1610 }
1611
1612
1613 /**
1614  * Download parts of a file based on a search result.  The download
1615  * will be associated with the search result (and the association
1616  * will be preserved when serializing/deserializing the state).
1617  * If the search is stopped, the download will not be aborted but
1618  * be 'promoted' to a stand-alone download.
1619  *
1620  * As with the other download function, this will store
1621  * the blocks at the respective offset in the given file.  Also, the
1622  * download is still using the blocking of the underlying FS
1623  * encoding.  As a result, the download may *write* outside of the
1624  * given boundaries (if offset and length do not match the 32k FS
1625  * block boundaries). <p>
1626  *
1627  * The given range can be used to focus a download towards a
1628  * particular portion of the file (optimization), not to strictly
1629  * limit the download to exactly those bytes.
1630  *
1631  * @param h handle to the file sharing subsystem
1632  * @param sr the search result to use for the download (determines uri and
1633  *        meta data and associations)
1634  * @param filename where to store the file, maybe NULL (then no file is
1635  *        created on disk and data must be grabbed from the callbacks)
1636  * @param tempname where to store temporary file data, not used if filename is non-NULL;
1637  *        can be NULL (in which case we will pick a name if needed); the temporary file
1638  *        may already exist, in which case we will try to use the data that is there and
1639  *        if it is not what is desired, will overwrite it
1640  * @param offset at what offset should we start the download (typically 0)
1641  * @param length how many bytes should be downloaded starting at offset
1642  * @param anonymity anonymity level to use for the download
1643  * @param options various download options
1644  * @param cctx initial value for the client context for this download
1645  * @return context that can be used to control this download
1646  */
1647 struct GNUNET_FS_DownloadContext *
1648 GNUNET_FS_download_start_from_search (struct GNUNET_FS_Handle *h,
1649                                       struct GNUNET_FS_SearchResult *sr,
1650                                       const char *filename,
1651                                       const char *tempname,
1652                                       uint64_t offset,
1653                                       uint64_t length,
1654                                       uint32_t anonymity,
1655                                       enum GNUNET_FS_DownloadOptions options,
1656                                       void *cctx)
1657 {
1658   struct GNUNET_FS_ProgressInfo pi;
1659   struct GNUNET_FS_DownloadContext *dc;
1660
1661   if ( (sr == NULL) ||
1662        (sr->download != NULL) )
1663     {
1664       GNUNET_break (0);
1665       return NULL;
1666     }
1667   GNUNET_assert (GNUNET_FS_uri_test_chk (sr->uri));
1668   if ( (offset + length < offset) ||
1669        (offset + length > sr->uri->data.chk.file_length) )
1670     {
1671       GNUNET_break (0);
1672       return NULL;
1673     }
1674 #if DEBUG_DOWNLOAD
1675   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1676               "Starting download `%s' of %llu bytes\n",
1677               filename,
1678               (unsigned long long) length);
1679 #endif
1680   dc = GNUNET_malloc (sizeof(struct GNUNET_FS_DownloadContext));
1681   dc->h = h;
1682   dc->search = sr;
1683   sr->download = dc;
1684   if (sr->probe_ctx != NULL)
1685     {
1686       GNUNET_FS_download_stop (sr->probe_ctx, GNUNET_YES);
1687       sr->probe_ctx = NULL;
1688     }
1689   dc->uri = GNUNET_FS_uri_dup (sr->uri);
1690   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (sr->meta);
1691   dc->client_info = cctx;
1692   dc->start_time = GNUNET_TIME_absolute_get ();
1693   if (NULL != filename)
1694     {
1695       dc->filename = GNUNET_strdup (filename);
1696       if (GNUNET_YES == GNUNET_DISK_file_test (filename))
1697         GNUNET_DISK_file_size (filename,
1698                                &dc->old_file_size,
1699                                GNUNET_YES);
1700     }
1701   if (GNUNET_FS_uri_test_loc (dc->uri))
1702     GNUNET_assert (GNUNET_OK ==
1703                    GNUNET_FS_uri_loc_get_peer_identity (dc->uri,
1704                                                         &dc->target));
1705   dc->offset = offset;
1706   dc->length = length;
1707   dc->anonymity = anonymity;
1708   dc->options = options;
1709   dc->active = GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
1710   dc->treedepth = GNUNET_FS_compute_depth (GNUNET_ntohll(dc->uri->data.chk.file_length));
1711   if ( (filename == NULL) &&
1712        (is_recursive_download (dc) ) )
1713     {
1714       if (tempname != NULL)
1715         dc->temp_filename = GNUNET_strdup (tempname);
1716       else
1717         dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
1718     }
1719
1720 #if DEBUG_DOWNLOAD
1721   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1722               "Download tree has depth %u\n",
1723               dc->treedepth);
1724 #endif
1725   pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
1726   pi.value.download.specifics.start.meta = dc->meta;
1727   GNUNET_FS_download_make_status_ (&pi, dc);
1728   schedule_block_download (dc,
1729                            &dc->uri->data.chk.chk,
1730                            0,
1731                            1 /* 0 == CHK, 1 == top */);
1732   GNUNET_FS_download_sync_ (dc);
1733   GNUNET_FS_download_start_downloading_ (dc);
1734   return dc;
1735 }
1736
1737
1738 /**
1739  * Start the downloading process (by entering the queue).
1740  *
1741  * @param dc our download context
1742  */
1743 void
1744 GNUNET_FS_download_start_downloading_ (struct GNUNET_FS_DownloadContext *dc)
1745 {
1746   GNUNET_assert (dc->job_queue == NULL);
1747   dc->job_queue = GNUNET_FS_queue_ (dc->h,
1748                                     &activate_fs_download,
1749                                     &deactivate_fs_download,
1750                                     dc,
1751                                     (dc->length + DBLOCK_SIZE-1) / DBLOCK_SIZE);
1752 }
1753
1754
1755 /**
1756  * Stop a download (aborts if download is incomplete).
1757  *
1758  * @param dc handle for the download
1759  * @param do_delete delete files of incomplete downloads
1760  */
1761 void
1762 GNUNET_FS_download_stop (struct GNUNET_FS_DownloadContext *dc,
1763                          int do_delete)
1764 {
1765   struct GNUNET_FS_ProgressInfo pi;
1766   int have_children;
1767
1768   if (dc->top != NULL)
1769     GNUNET_FS_end_top (dc->h, dc->top);
1770   if (dc->search != NULL)
1771     {
1772       dc->search->download = NULL;
1773       dc->search = NULL;
1774     }
1775   if (dc->job_queue != NULL)
1776     {
1777       GNUNET_FS_dequeue_ (dc->job_queue);
1778       dc->job_queue = NULL;
1779     }
1780   have_children = (NULL != dc->child_head) ? GNUNET_YES : GNUNET_NO;
1781   while (NULL != dc->child_head)
1782     GNUNET_FS_download_stop (dc->child_head,
1783                              do_delete);
1784   if (dc->parent != NULL)
1785     GNUNET_CONTAINER_DLL_remove (dc->parent->child_head,
1786                                  dc->parent->child_tail,
1787                                  dc);
1788   if (dc->serialization != NULL)
1789     GNUNET_FS_remove_sync_file_ (dc->h,
1790                                  ( (dc->parent != NULL)  || (dc->search != NULL) )
1791                                  ? GNUNET_FS_SYNC_PATH_CHILD_DOWNLOAD
1792                                  : GNUNET_FS_SYNC_PATH_MASTER_DOWNLOAD ,
1793                                  dc->serialization);
1794   if ( (GNUNET_YES == have_children) &&
1795        (dc->parent == NULL) )
1796     GNUNET_FS_remove_sync_dir_ (dc->h,
1797                                 (dc->search != NULL)
1798                                 ? GNUNET_FS_SYNC_PATH_CHILD_DOWNLOAD
1799                                 : GNUNET_FS_SYNC_PATH_MASTER_DOWNLOAD,
1800                                 dc->serialization);
1801   pi.status = GNUNET_FS_STATUS_DOWNLOAD_STOPPED;
1802   GNUNET_FS_download_make_status_ (&pi, dc);
1803   if (GNUNET_SCHEDULER_NO_TASK != dc->task)
1804     GNUNET_SCHEDULER_cancel (dc->h->sched,
1805                              dc->task);
1806   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
1807                                          &free_entry,
1808                                          NULL);
1809   GNUNET_CONTAINER_multihashmap_destroy (dc->active);
1810   if (dc->filename != NULL)
1811     {
1812       if ( (dc->completed != dc->length) &&
1813            (GNUNET_YES == do_delete) )
1814         {
1815           if (0 != UNLINK (dc->filename))
1816             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
1817                                       "unlink",
1818                                       dc->filename);
1819         }
1820       GNUNET_free (dc->filename);
1821     }
1822   GNUNET_CONTAINER_meta_data_destroy (dc->meta);
1823   GNUNET_FS_uri_destroy (dc->uri);
1824   if (NULL != dc->temp_filename)
1825     {
1826       if (0 != UNLINK (dc->temp_filename))
1827         GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
1828                                   "unlink",
1829                                   dc->temp_filename);
1830       GNUNET_free (dc->temp_filename);
1831     }
1832   GNUNET_free_non_null (dc->serialization);
1833   GNUNET_free (dc);
1834 }
1835
1836 /* end of fs_download.c */