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