make clang static analysis happy
[oweals/gnunet.git] / src / fs / fs_download.c
index 6d3886c70e8689a4451dcc44d7a0bf060c4eeb1a..6e215ed27a98025de3769e98f1c5cda7dee6ab96 100644 (file)
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009 Christian Grothoff (and other contributing authors)
+     (C) 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009, 2010 Christian Grothoff (and other contributing authors)
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
  * @author Christian Grothoff
  *
  * TODO:
+ * - handle recursive downloads (need directory & 
+ *   fs-level download-parallelism management)
+ * - handle recursive downloads where directory file is
+ *   NOT saved on disk (need temporary file instead then!)
  * - location URI suppport (can wait, easy)
  * - check if blocks exist already (can wait, easy)
- * - handle recursive downloads (need directory & 
- *   fs-level download-parallelism management, can wait)
  * - check if iblocks can be computed from existing blocks (can wait, hard)
  * - persistence (can wait)
  */
 #include "fs.h"
 #include "fs_tree.h"
 
-#define DEBUG_DOWNLOAD GNUNET_YES
+#define DEBUG_DOWNLOAD GNUNET_NO
 
 /**
- * We're storing the IBLOCKS after the
- * DBLOCKS on disk (so that we only have
- * to truncate the file once we're done).
+ * We're storing the IBLOCKS after the DBLOCKS on disk (so that we
+ * only have to truncate the file once we're done).
  *
- * Given the offset of a block (with respect
- * to the DBLOCKS) and its depth, return the
- * offset where we would store this block
- * in the file.
-
+ * Given the offset of a block (with respect to the DBLOCKS) and its
+ * depth, return the offset where we would store this block in the
+ * file.
  * 
  * @param fsize overall file size
  * @param off offset of the block in the file
@@ -65,9 +64,9 @@ compute_disk_offset (uint64_t fsize,
                     unsigned int treedepth)
 {
   unsigned int i;
-  uint64_t lsize; /* what is the size of all IBlocks for level "i"? */
-  uint64_t loff; /* where do IBlocks for level "i" start? */
-  unsigned int ioff; /* which IBlock corresponds to "off" at level "i"? */
+  uint64_t lsize; /* what is the size of all IBlocks for depth "i"? */
+  uint64_t loff; /* where do IBlocks for depth "i" start? */
+  unsigned int ioff; /* which IBlock corresponds to "off" at depth "i"? */
   
   if (depth == treedepth)
     return off;
@@ -113,14 +112,14 @@ compute_dblock_offset (uint64_t offset,
 {
   unsigned int i;
   uint64_t lsize; /* what is the size of the sum of all DBlocks 
-                    that a CHK at level i corresponds to? */
+                    that a CHK at depth i corresponds to? */
 
   if (depth == treedepth)
     return offset;
   lsize = DBLOCK_SIZE;
   for (i=treedepth-1;i>depth;i--)
     lsize *= CHK_PER_INODE;
-  return offset + i * lsize;
+  return offset + k * lsize;
 }
 
 
@@ -152,12 +151,31 @@ make_download_status (struct GNUNET_FS_ProgressInfo *pi,
     = dc->completed;
   pi->value.download.anonymity
     = dc->anonymity;
+  pi->value.download.eta
+    = GNUNET_TIME_calculate_eta (dc->start_time,
+                                dc->completed,
+                                dc->length);
 }
 
+/**
+ * We're ready to transmit a search request to the
+ * file-sharing service.  Do it.  If there is 
+ * more than one request pending, try to send 
+ * multiple or request another transmission.
+ *
+ * @param cls closure
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t
+transmit_download_request (void *cls,
+                          size_t size, 
+                          void *buf);
+
 
 /**
- * Schedule the download of the specified
- * block in the tree.
+ * Schedule the download of the specified block in the tree.
  *
  * @param dc overall download this block belongs to
  * @param chk content-hash-key of the block
@@ -217,6 +235,151 @@ schedule_block_download (struct GNUNET_FS_DownloadContext *dc,
                                     &chk->query,
                                     sm,
                                     GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
+
+  if ( (dc->th == NULL) &&
+       (dc->client != NULL) )
+    dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
+                                                 sizeof (struct SearchMessage),
+                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
+                                                 GNUNET_NO,
+                                                 &transmit_download_request,
+                                                 dc);
+}
+
+
+
+/**
+ * Suggest a filename based on given metadata.
+ * 
+ * @param md given meta data
+ * @return NULL if meta data is useless for suggesting a filename
+ */
+char *
+GNUNET_FS_meta_data_suggest_filename (const struct GNUNET_CONTAINER_MetaData *md)
+{
+  static const char *mimeMap[][2] = {
+    {"application/bz2", ".bz2"},
+    {"application/gnunet-directory", ".gnd"},
+    {"application/java", ".class"},
+    {"application/msword", ".doc"},
+    {"application/ogg", ".ogg"},
+    {"application/pdf", ".pdf"},
+    {"application/pgp-keys", ".key"},
+    {"application/pgp-signature", ".pgp"},
+    {"application/postscript", ".ps"},
+    {"application/rar", ".rar"},
+    {"application/rtf", ".rtf"},
+    {"application/xml", ".xml"},
+    {"application/x-debian-package", ".deb"},
+    {"application/x-dvi", ".dvi"},
+    {"applixation/x-flac", ".flac"},
+    {"applixation/x-gzip", ".gz"},
+    {"application/x-java-archive", ".jar"},
+    {"application/x-java-vm", ".class"},
+    {"application/x-python-code", ".pyc"},
+    {"application/x-redhat-package-manager", ".rpm"},
+    {"application/x-rpm", ".rpm"},
+    {"application/x-tar", ".tar"},
+    {"application/x-tex-pk", ".pk"},
+    {"application/x-texinfo", ".texinfo"},
+    {"application/x-xcf", ".xcf"},
+    {"application/x-xfig", ".xfig"},
+    {"application/zip", ".zip"},
+    
+    {"audio/midi", ".midi"},
+    {"audio/mpeg", ".mp3"},
+    {"audio/real", ".rm"},
+    {"audio/x-wav", ".wav"},
+    
+    {"image/gif", ".gif"},
+    {"image/jpeg", ".jpg"},
+    {"image/pcx", ".pcx"},
+    {"image/png", ".png"},
+    {"image/tiff", ".tiff"},
+    {"image/x-ms-bmp", ".bmp"},
+    {"image/x-xpixmap", ".xpm"},
+    
+    {"text/css", ".css"},
+    {"text/html", ".html"},
+    {"text/plain", ".txt"},
+    {"text/rtf", ".rtf"},
+    {"text/x-c++hdr", ".h++"},
+    {"text/x-c++src", ".c++"},
+    {"text/x-chdr", ".h"},
+    {"text/x-csrc", ".c"},
+    {"text/x-java", ".java"},
+    {"text/x-moc", ".moc"},
+    {"text/x-pascal", ".pas"},
+    {"text/x-perl", ".pl"},
+    {"text/x-python", ".py"},
+    {"text/x-tex", ".tex"},
+    
+    {"video/avi", ".avi"},
+    {"video/mpeg", ".mpeg"},
+    {"video/quicktime", ".qt"},
+    {"video/real", ".rm"},
+    {"video/x-msvideo", ".avi"},
+    {NULL, NULL},
+  };
+  char *ret;
+  unsigned int i;
+  char *mime;
+  char *base;
+  const char *ext;
+
+  ret = GNUNET_CONTAINER_meta_data_get_by_type (md,
+                                               EXTRACTOR_METATYPE_FILENAME);
+  if (ret != NULL)
+    return ret;  
+  ext = NULL;
+  mime = GNUNET_CONTAINER_meta_data_get_by_type (md,
+                                                EXTRACTOR_METATYPE_MIMETYPE);
+  if (mime != NULL)
+    {
+      i = 0;
+      while ( (mimeMap[i][0] != NULL) && 
+             (0 != strcmp (mime, mimeMap[i][0])))
+        i++;
+      if (mimeMap[i][1] == NULL)
+        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG | 
+                   GNUNET_ERROR_TYPE_BULK,
+                   _("Did not find mime type `%s' in extension list.\n"),
+                   mime);
+      else
+       ext = mimeMap[i][1];
+      GNUNET_free (mime);
+    }
+  base = GNUNET_CONTAINER_meta_data_get_first_by_types (md,
+                                                       EXTRACTOR_METATYPE_TITLE,
+                                                       EXTRACTOR_METATYPE_BOOK_TITLE,
+                                                       EXTRACTOR_METATYPE_ORIGINAL_TITLE,
+                                                       EXTRACTOR_METATYPE_PACKAGE_NAME,
+                                                       EXTRACTOR_METATYPE_URL,
+                                                       EXTRACTOR_METATYPE_URI, 
+                                                       EXTRACTOR_METATYPE_DESCRIPTION,
+                                                       EXTRACTOR_METATYPE_ISRC,
+                                                       EXTRACTOR_METATYPE_JOURNAL_NAME,
+                                                       EXTRACTOR_METATYPE_AUTHOR_NAME,
+                                                       EXTRACTOR_METATYPE_SUBJECT,
+                                                       EXTRACTOR_METATYPE_ALBUM,
+                                                       EXTRACTOR_METATYPE_ARTIST,
+                                                       EXTRACTOR_METATYPE_KEYWORDS,
+                                                       EXTRACTOR_METATYPE_COMMENT,
+                                                       EXTRACTOR_METATYPE_UNKNOWN,
+                                                       -1);
+  if ( (base == NULL) &&
+       (ext == NULL) )
+    return NULL;
+  if (base == NULL)
+    return GNUNET_strdup (ext);
+  if (ext == NULL)
+    return base;
+  GNUNET_asprintf (&ret,
+                  "%s%s",
+                  base,
+                  ext);
+  GNUNET_free (base);
+  return ret;
 }
 
 
@@ -277,44 +440,349 @@ calculate_block_size (uint64_t fsize,
 
 
 /**
- * Process a download result.
+ * Closure for iterator processing results.
+ */
+struct ProcessResultClosure
+{
+  
+  /**
+   * Hash of data.
+   */
+  GNUNET_HashCode query;
+
+  /**
+   * Data found in P2P network.
+   */ 
+  const void *data;
+
+  /**
+   * Our download context.
+   */
+  struct GNUNET_FS_DownloadContext *dc;
+               
+  /**
+   * Number of bytes in data.
+   */
+  size_t size;
+
+  /**
+   * Type of data.
+   */
+  uint32_t type;
+  
+};
+
+
+/**
+ * We found an entry in a directory.  Check if the respective child
+ * already exists and if not create the respective child download.
  *
- * @param dc our download context
- * @param type type of the result
- * @param data the (encrypted) response
- * @param size size of data
+ * @param cls the parent download
+ * @param filename name of the file in the directory
+ * @param uri URI of the file (CHK or LOC)
+ * @param meta meta data of the file
+ * @param length number of bytes in data
+ * @param data contents of the file (or NULL if they were not inlined)
+ */
+static void 
+trigger_recursive_download (void *cls,
+                           const char *filename,
+                           const struct GNUNET_FS_Uri *uri,
+                           const struct GNUNET_CONTAINER_MetaData *meta,
+                           size_t length,
+                           const void *data)
+{
+  struct GNUNET_FS_DownloadContext *dc = cls;  
+  struct GNUNET_FS_DownloadContext *cpos;
+  struct GNUNET_DISK_FileHandle *fh;
+  char *fn;
+  char *us;
+  char *ext;
+  char *dn;
+  char *full_name;
+
+  if (NULL == uri)
+    return; /* entry for the directory itself */
+  cpos = dc->child_head;
+  while (cpos != NULL)
+    {
+      if ( (GNUNET_FS_uri_test_equal (uri,
+                                     cpos->uri)) ||
+          ( (filename != NULL) &&
+            (0 == strcmp (cpos->filename,
+                          filename)) ) )
+       break;  
+      cpos = cpos->next;
+    }
+  if (cpos != NULL)
+    return; /* already exists */
+  fn = NULL;
+  if (NULL == filename)
+    {
+      fn = GNUNET_FS_meta_data_suggest_filename (meta);      
+      if (fn == NULL)
+       {
+         us = GNUNET_FS_uri_to_string (uri);
+         fn = GNUNET_strdup (&us [strlen (GNUNET_FS_URI_PREFIX 
+                                          GNUNET_FS_URI_CHK_INFIX)]);
+         GNUNET_free (us);
+       }
+      else if (fn[0] == '.')
+       {
+         ext = fn;
+         us = GNUNET_FS_uri_to_string (uri);
+         GNUNET_asprintf (&fn,
+                          "%s%s",
+                          &us[strlen (GNUNET_FS_URI_PREFIX 
+                                      GNUNET_FS_URI_CHK_INFIX)], ext);
+         GNUNET_free (ext);
+         GNUNET_free (us);
+       }
+      filename = fn;
+    }
+  if (dc->filename == NULL)
+    {
+      full_name = NULL;
+    }
+  else
+    {
+      dn = GNUNET_strdup (dc->filename);
+      GNUNET_break ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
+                    (NULL !=
+                     strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
+                             GNUNET_FS_DIRECTORY_EXT)) );
+      if ( (strlen (dn) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
+          (NULL !=
+           strstr (dn + strlen(dn) - strlen(GNUNET_FS_DIRECTORY_EXT),
+                   GNUNET_FS_DIRECTORY_EXT)) )      
+       dn[strlen(dn) - strlen (GNUNET_FS_DIRECTORY_EXT)] = '\0';      
+      if ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (meta)) &&
+          ( (strlen (filename) < strlen (GNUNET_FS_DIRECTORY_EXT)) ||
+            (NULL ==
+             strstr (filename + strlen(filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
+                     GNUNET_FS_DIRECTORY_EXT)) ) )
+       {
+         GNUNET_asprintf (&full_name,
+                          "%s%s%s%s",
+                          dn,
+                          DIR_SEPARATOR_STR,
+                          filename,
+                          GNUNET_FS_DIRECTORY_EXT);
+       }
+      else
+       {
+         GNUNET_asprintf (&full_name,
+                          "%s%s%s",
+                          dn,
+                          DIR_SEPARATOR_STR,
+                          filename);
+       }
+      GNUNET_free (dn);
+    }
+  if ( (full_name != NULL) &&
+       (GNUNET_OK !=
+       GNUNET_DISK_directory_create_for_file (full_name)) )
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                 _("Failed to create directory for recursive download of `%s'\n"),
+                 full_name);
+      GNUNET_free (full_name);
+      GNUNET_free_non_null (fn);
+      return;
+    }
+    
+  if (data != NULL) 
+    {
+      if (full_name != NULL)
+       {
+         fh = GNUNET_DISK_file_open (full_name,
+                                     GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_TRUNCATE | GNUNET_DISK_OPEN_CREATE,
+                                     GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE);
+         if (fh == NULL)
+           {
+             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
+                                       "open",
+                                       full_name);           
+             GNUNET_free (full_name);
+             GNUNET_free_non_null (fn);
+             return;
+           }
+         if (length != 
+             GNUNET_DISK_file_write (fh,
+                                     data,
+                                     length))
+           {
+             GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
+                                       "write",
+                                       full_name);           
+           }
+         GNUNET_DISK_file_close (fh);
+       }
+      else
+       {
+         /* FIXME: generate 'progress' events and move to
+            instant completion! */
+         GNUNET_break (0); // FIXME: not implemented
+       }
+    }
+  GNUNET_FS_download_start (dc->h,
+                           uri,
+                           meta,
+                           full_name,
+                           0,
+                           GNUNET_FS_uri_chk_get_file_size (uri),
+                           dc->anonymity,
+                           dc->options,
+                           NULL,
+                           dc);
+  GNUNET_free_non_null (full_name);
+  GNUNET_free_non_null (fn);
+}
+
+
+/**
+ * We're done downloading a directory.  Open the file and
+ * trigger all of the (remaining) child downloads.
+ *
+ * @param dc context of download that just completed
  */
 static void
-process_result (struct GNUNET_FS_DownloadContext *dc,
-               uint32_t type,
-               const void *data,
-               size_t size)
+full_recursive_download (struct GNUNET_FS_DownloadContext *dc)
+{
+  size_t size;
+  uint64_t size64;
+  void *data;
+  struct GNUNET_DISK_FileHandle *h;
+  struct GNUNET_DISK_MapHandle *m;
+  
+  size64 = GNUNET_FS_uri_chk_get_file_size (dc->uri);
+  size = (size_t) size64;
+  if (size64 != (uint64_t) size)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                 _("Recursive downloads of directories larger than 4 GB are not supported on 32-bit systems\n"));
+      return;
+    }
+  if (dc->filename != NULL)
+    {
+      h = GNUNET_DISK_file_open (dc->filename,
+                                GNUNET_DISK_OPEN_READ,
+                                GNUNET_DISK_PERM_NONE);
+    }
+  else
+    {
+      /* FIXME: need to initialize (and use) temp_filename
+        in various places in order for this assertion to
+        not fail; right now, it will always fail! */
+      GNUNET_assert (dc->temp_filename != NULL);
+      h = GNUNET_DISK_file_open (dc->temp_filename,
+                                GNUNET_DISK_OPEN_READ,
+                                GNUNET_DISK_PERM_NONE);
+    }
+  if (h == NULL)
+    return; /* oops */
+  data = GNUNET_DISK_file_map (h, &m, GNUNET_DISK_MAP_TYPE_READ, size);
+  if (data == NULL)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                 _("Directory too large for system address space\n"));
+    }
+  else
+    {
+      GNUNET_FS_directory_list_contents (size,
+                                        data,
+                                        0,
+                                        &trigger_recursive_download,
+                                        dc);         
+      GNUNET_DISK_file_unmap (m);
+    }
+  GNUNET_DISK_file_close (h);
+  if (dc->filename == NULL)
+    {
+      if (0 != UNLINK (dc->temp_filename))
+       GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
+                                 "unlink",
+                                 dc->temp_filename);
+      GNUNET_free (dc->temp_filename);
+      dc->temp_filename = NULL;
+    }
+}
+
+
+/**
+ * Check if all child-downloads have completed and
+ * if so, signal completion (and possibly recurse to
+ * parent).
+ */
+static void
+check_completed (struct GNUNET_FS_DownloadContext *dc)
 {
   struct GNUNET_FS_ProgressInfo pi;
-  GNUNET_HashCode query;
-  struct DownloadRequest *sm;
+  struct GNUNET_FS_DownloadContext *pos;
+
+  pos = dc->child_head;
+  while (pos != NULL)
+    {
+      if ( (pos->emsg == NULL) &&
+          (pos->completed < pos->length) )
+       return; /* not done yet */
+      if ( (pos->child_head != NULL) &&
+          (pos->has_finished != GNUNET_YES) )
+       return; /* not transitively done yet */
+      pos = pos->next;
+    }
+  dc->has_finished = GNUNET_YES;
+  /* signal completion */
+  pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
+  make_download_status (&pi, dc);
+  dc->client_info = dc->h->upcb (dc->h->upcb_cls,
+                                &pi);
+  if (dc->parent != NULL)
+    check_completed (dc->parent);  
+}
+
+
+/**
+ * Iterator over entries in the pending requests in the 'active' map for the
+ * reply that we just got.
+ *
+ * @param cls closure (our 'struct ProcessResultClosure')
+ * @param key query for the given value / request
+ * @param value value in the hash map (a 'struct DownloadRequest')
+ * @return GNUNET_YES (we should continue to iterate); unless serious error
+ */
+static int
+process_result_with_request (void *cls,
+                            const GNUNET_HashCode * key,
+                            void *value)
+{
+  struct ProcessResultClosure *prc = cls;
+  struct DownloadRequest *sm = value;
+  struct GNUNET_FS_DownloadContext *dc = prc->dc;
   struct GNUNET_CRYPTO_AesSessionKey skey;
   struct GNUNET_CRYPTO_AesInitializationVector iv;
-  char pt[size];
+  char pt[prc->size];
+  struct GNUNET_FS_ProgressInfo pi;
   uint64_t off;
   size_t app;
-  unsigned int i;
+  int i;
   struct ContentHashKey *chk;
   char *emsg;
 
-  GNUNET_CRYPTO_hash (data, size, &query);
-  sm = GNUNET_CONTAINER_multihashmap_get (dc->active,
-                                         &query);
-  if (NULL == sm)
-    {
-      GNUNET_break (0);
-      return;
-    }
-  if (size != calculate_block_size (GNUNET_ntohll (dc->uri->data.chk.file_length),
-                                   dc->treedepth,
-                                   sm->offset,
-                                   sm->depth))
+  if (prc->size != calculate_block_size (GNUNET_ntohll (dc->uri->data.chk.file_length),
+                                        dc->treedepth,
+                                        sm->offset,
+                                        sm->depth))
     {
+#if DEBUG_DOWNLOAD
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Internal error or bogus download URI (expected %u bytes, got %u)\n",
+                 calculate_block_size (GNUNET_ntohll (dc->uri->data.chk.file_length),
+                                       dc->treedepth,
+                                       sm->offset,
+                                       sm->depth),
+                 prc->size);
+#endif
       dc->emsg = GNUNET_strdup ("Internal error or bogus download URI");
       /* signal error */
       pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
@@ -323,30 +791,40 @@ process_result (struct GNUNET_FS_DownloadContext *dc,
       dc->client_info = dc->h->upcb (dc->h->upcb_cls,
                                     &pi);
       /* abort all pending requests */
-      GNUNET_CLIENT_disconnect (dc->client);
+      if (NULL != dc->th)
+       {
+         GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
+         dc->th = NULL;
+       }
+      GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
       dc->client = NULL;
-      return;
+      return GNUNET_NO;
     }
   GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove (dc->active,
-                                                      &query,
+                                                      &prc->query,
                                                       sm));
   GNUNET_CRYPTO_hash_to_aes_key (&sm->chk.key, &skey, &iv);
-  GNUNET_CRYPTO_aes_decrypt (data,
-                            size,
+  GNUNET_CRYPTO_aes_decrypt (prc->data,
+                            prc->size,
                             &skey,
                             &iv,
                             pt);
+  off = compute_disk_offset (GNUNET_ntohll (dc->uri->data.chk.file_length),
+                            sm->offset,
+                            sm->depth,
+                            dc->treedepth);
   /* save to disk */
   if ( (NULL != dc->handle) &&
        ( (sm->depth == dc->treedepth) ||
         (0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES)) ) )
     {
-      off = compute_disk_offset (GNUNET_ntohll (dc->uri->data.chk.file_length),
-                                sm->offset,
-                                sm->depth,
-                                dc->treedepth);
       emsg = NULL;
+#if DEBUG_DOWNLOAD
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Saving decrypted block to disk at offset %llu\n",
+                 (unsigned long long) off);
+#endif
       if ( (off  != 
            GNUNET_DISK_file_seek (dc->handle,
                                   off,
@@ -356,13 +834,13 @@ process_result (struct GNUNET_FS_DownloadContext *dc,
                         (unsigned long long) off,
                         dc->filename,
                         STRERROR (errno));
-      else if (size !=
+      else if (prc->size !=
               GNUNET_DISK_file_write (dc->handle,
                                       pt,
-                                      size))
+                                      prc->size))
        GNUNET_asprintf (&emsg,
                         _("Failed to write block of %u bytes at offset %llu in file `%s': %s\n"),
-                        (unsigned int) size,
+                        (unsigned int) prc->size,
                         (unsigned long long) off,
                         dc->filename,
                         STRERROR (errno));
@@ -379,14 +857,20 @@ process_result (struct GNUNET_FS_DownloadContext *dc,
                                         &pi);
 
          /* abort all pending requests */
-         GNUNET_CLIENT_disconnect (dc->client);
+         if (NULL != dc->th)
+           {
+             GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
+             dc->th = NULL;
+           }
+         GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
          dc->client = NULL;
-         return;
+         GNUNET_free (sm);
+         return GNUNET_NO;
        }
     }
   if (sm->depth == dc->treedepth) 
     {
-      app = size;
+      app = prc->size;
       if (sm->offset < dc->offset)
        {
          /* starting offset begins in the middle of pt,
@@ -394,27 +878,49 @@ process_result (struct GNUNET_FS_DownloadContext *dc,
          GNUNET_assert (app > (dc->offset - sm->offset));
          app -= (dc->offset - sm->offset);       
        }
-      if (sm->offset + size > dc->offset + dc->length)
+      if (sm->offset + prc->size > dc->offset + dc->length)
        {
          /* end of block is after relevant range,
             do not count last bytes as progress */
-         GNUNET_assert (app > (sm->offset + size) - (dc->offset + dc->length));
-         app -= (sm->offset + size) - (dc->offset + dc->length);
+         GNUNET_assert (app > (sm->offset + prc->size) - (dc->offset + dc->length));
+         app -= (sm->offset + prc->size) - (dc->offset + dc->length);
        }
       dc->completed += app;
-    }
 
+      /* do recursive download if option is set and either meta data
+        says it is a directory or if no meta data is given AND filename 
+        ends in '.gnd' (top-level case) */
+      if ( (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_RECURSIVE)) &&
+          ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (dc->meta)) ||
+            ( (dc->meta == NULL) &&
+              ( (NULL == dc->filename) ||             
+                ( (strlen (dc->filename) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
+                  (NULL !=
+                   strstr (dc->filename + strlen(dc->filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
+                           GNUNET_FS_DIRECTORY_EXT)) ) ) ) ) ) 
+       GNUNET_FS_directory_list_contents (prc->size,
+                                          pt,
+                                          off,
+                                          &trigger_recursive_download,
+                                          dc);         
+           
+    }
   pi.status = GNUNET_FS_STATUS_DOWNLOAD_PROGRESS;
   make_download_status (&pi, dc);
   pi.value.download.specifics.progress.data = pt;
   pi.value.download.specifics.progress.offset = sm->offset;
-  pi.value.download.specifics.progress.data_len = size;
+  pi.value.download.specifics.progress.data_len = prc->size;
   pi.value.download.specifics.progress.depth = sm->depth;
   dc->client_info = dc->h->upcb (dc->h->upcb_cls,
                                 &pi);
   GNUNET_assert (dc->completed <= dc->length);
   if (dc->completed == dc->length)
     {
+#if DEBUG_DOWNLOAD
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Download completed, truncating file to desired length %llu\n",
+                 (unsigned long long) GNUNET_ntohll (dc->uri->data.chk.file_length));
+#endif
       /* truncate file to size (since we store IBlocks at the end) */
       if (dc->handle != NULL)
        {
@@ -426,19 +932,43 @@ process_result (struct GNUNET_FS_DownloadContext *dc,
                                      "truncate",
                                      dc->filename);
        }
-      /* signal completion */
-      pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
-      make_download_status (&pi, dc);
-      dc->client_info = dc->h->upcb (dc->h->upcb_cls,
-                                    &pi);
+
+      if ( (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_RECURSIVE)) &&
+          ( (GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (dc->meta)) ||
+            ( (dc->meta == NULL) &&
+              ( (NULL == dc->filename) ||             
+                ( (strlen (dc->filename) >= strlen (GNUNET_FS_DIRECTORY_EXT)) &&
+                  (NULL !=
+                   strstr (dc->filename + strlen(dc->filename) - strlen(GNUNET_FS_DIRECTORY_EXT),
+                           GNUNET_FS_DIRECTORY_EXT)) ) ) ) ) ) 
+       full_recursive_download (dc);
+      if (dc->child_head == NULL)
+       {
+         /* signal completion */
+         pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
+         make_download_status (&pi, dc);
+         dc->client_info = dc->h->upcb (dc->h->upcb_cls,
+                                        &pi);
+         if (dc->parent != NULL)
+           check_completed (dc->parent);
+       }
       GNUNET_assert (sm->depth == dc->treedepth);
     }
   // FIXME: make persistent
   if (sm->depth == dc->treedepth) 
-    return;
-  GNUNET_assert (0 == (size % sizeof(struct ContentHashKey)));
+    {
+      GNUNET_free (sm);      
+      return GNUNET_YES;
+    }
+#if DEBUG_DOWNLOAD
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Triggering downloads of children (this block was at depth %u and offset %llu)\n",
+             sm->depth,
+             (unsigned long long) sm->offset);
+#endif
+  GNUNET_assert (0 == (prc->size % sizeof(struct ContentHashKey)));
   chk = (struct ContentHashKey*) pt;
-  for (i=0;i<(size / sizeof(struct ContentHashKey));i++)
+  for (i=(prc->size / sizeof(struct ContentHashKey))-1;i>=0;i--)
     {
       off = compute_dblock_offset (sm->offset,
                                   sm->depth,
@@ -451,6 +981,42 @@ process_result (struct GNUNET_FS_DownloadContext *dc,
                                 off,
                                 sm->depth + 1);
     }
+  GNUNET_free (sm);
+  return GNUNET_YES;
+}
+
+
+/**
+ * Process a download result.
+ *
+ * @param dc our download context
+ * @param type type of the result
+ * @param data the (encrypted) response
+ * @param size size of data
+ */
+static void
+process_result (struct GNUNET_FS_DownloadContext *dc,
+               uint32_t type,
+               const void *data,
+               size_t size)
+{
+  struct ProcessResultClosure prc;
+
+  prc.dc = dc;
+  prc.data = data;
+  prc.size = size;
+  prc.type = type;
+  GNUNET_CRYPTO_hash (data, size, &prc.query);
+#if DEBUG_DOWNLOAD
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Received result for query `%s' from `%s'-service\n",
+             GNUNET_h2s (&prc.query),
+             "FS");
+#endif
+  GNUNET_CONTAINER_multihashmap_get_multiple (dc->active,
+                                             &prc.query,
+                                             &process_result_with_request,
+                                             &prc);
 }
 
 
@@ -466,22 +1032,25 @@ receive_results (void *cls,
                 const struct GNUNET_MessageHeader * msg)
 {
   struct GNUNET_FS_DownloadContext *dc = cls;
-  const struct ContentMessage *cm;
+  const struct PutMessage *cm;
   uint16_t msize;
 
   if ( (NULL == msg) ||
-       (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_FS_CONTENT) ||
-       (ntohs (msg->size) <= sizeof (struct ContentMessage)) )
+       (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_FS_PUT) ||
+       (sizeof (struct PutMessage) > ntohs(msg->size)) )
     {
+      GNUNET_break (msg == NULL);      
       try_reconnect (dc);
       return;
     }
-  msize = ntohs (msg->size);
-  cm = (const struct ContentMessage*) msg;
+  msize = ntohs(msg->size);
+  cm = (const struct PutMessage*) msg;
   process_result (dc, 
                  ntohl (cm->type),
                  &cm[1],
-                 msize - sizeof (struct ContentMessage));
+                 msize - sizeof (struct PutMessage));
+  if (dc->client == NULL)
+    return; /* fatal error */
   /* continue receiving */
   GNUNET_CLIENT_receive (dc->client,
                         &receive_results,
@@ -511,6 +1080,7 @@ transmit_download_request (void *cls,
   size_t msize;
   struct SearchMessage *sm;
 
+  dc->th = NULL;
   if (NULL == buf)
     {
       try_reconnect (dc);
@@ -519,12 +1089,22 @@ transmit_download_request (void *cls,
   GNUNET_assert (size >= sizeof (struct SearchMessage));
   msize = 0;
   sm = buf;
-  while ( (dc->pending == NULL) &&
+  while ( (dc->pending != NULL) &&
          (size > msize + sizeof (struct SearchMessage)) )
     {
+#if DEBUG_DOWNLOAD
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Transmitting download request for `%s' to `%s'-service\n",
+                 GNUNET_h2s (&dc->pending->chk.query),
+                 "FS");
+#endif
       memset (sm, 0, sizeof (struct SearchMessage));
       sm->header.size = htons (sizeof (struct SearchMessage));
       sm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_START_SEARCH);
+      if (dc->pending->depth == dc->treedepth)
+       sm->type = htonl (GNUNET_DATASTORE_BLOCKTYPE_DBLOCK);
+      else
+       sm->type = htonl (GNUNET_DATASTORE_BLOCKTYPE_IBLOCK);
       sm->anonymity_level = htonl (dc->anonymity);
       sm->target = dc->target.hashPubKey;
       sm->query = dc->pending->chk.query;
@@ -533,13 +1113,19 @@ transmit_download_request (void *cls,
       msize += sizeof (struct SearchMessage);
       sm++;
     }
+  if (dc->pending != NULL)
+    dc->th = GNUNET_CLIENT_notify_transmit_ready (dc->client,
+                                                 sizeof (struct SearchMessage),
+                                                 GNUNET_CONSTANTS_SERVICE_TIMEOUT,
+                                                 GNUNET_NO,
+                                                 &transmit_download_request,
+                                                 dc); 
   return msize;
 }
 
 
 /**
- * Reconnect to the FS service and transmit
- * our queries NOW.
+ * Reconnect to the FS service and transmit our queries NOW.
  *
  * @param cls our download context
  * @param tc unused
@@ -557,15 +1143,19 @@ do_reconnect (void *cls,
                                  dc->h->cfg);
   if (NULL == client)
     {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                 "Connecting to `%s'-service failed, will try again.\n",
+                 "FS");
       try_reconnect (dc);
       return;
     }
   dc->client = client;
-  GNUNET_CLIENT_notify_transmit_ready (client,
-                                      sizeof (struct SearchMessage),
-                                       GNUNET_CONSTANTS_SERVICE_TIMEOUT,
-                                      &transmit_download_request,
-                                      dc);  
+  dc->th = GNUNET_CLIENT_notify_transmit_ready (client,
+                                               sizeof (struct SearchMessage),
+                                               GNUNET_CONSTANTS_SERVICE_TIMEOUT,
+                                               GNUNET_NO,
+                                               &transmit_download_request,
+                                               dc);  
   GNUNET_CLIENT_receive (client,
                         &receive_results,
                         dc,
@@ -574,8 +1164,7 @@ do_reconnect (void *cls,
 
 
 /**
- * Add entries that are not yet pending back to
- * the pending list.
+ * Add entries that are not yet pending back to the pending list.
  *
  * @param cls our download context
  * @param key unused
@@ -613,17 +1202,19 @@ try_reconnect (struct GNUNET_FS_DownloadContext *dc)
   
   if (NULL != dc->client)
     {
+      if (NULL != dc->th)
+       {
+         GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
+         dc->th = NULL;
+       }
       GNUNET_CONTAINER_multihashmap_iterate (dc->active,
                                             &retry_entry,
                                             dc);
-      GNUNET_CLIENT_disconnect (dc->client);
+      GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
       dc->client = NULL;
     }
   dc->task
     = GNUNET_SCHEDULER_add_delayed (dc->h->sched,
-                                   GNUNET_NO,
-                                   GNUNET_SCHEDULER_PRIORITY_IDLE,
-                                   GNUNET_SCHEDULER_NO_TASK,
                                    GNUNET_TIME_UNIT_SECONDS,
                                    &do_reconnect,
                                    dc);
@@ -651,6 +1242,7 @@ try_reconnect (struct GNUNET_FS_DownloadContext *dc)
  * @param length how many bytes should be downloaded starting at offset
  * @param anonymity anonymity level to use for the download
  * @param options various options
+ * @param cctx initial value for the client context for this download
  * @param parent parent download to associate this download with (use NULL
  *        for top-level downloads; useful for manually-triggered recursive downloads)
  * @return context that can be used to control this download
@@ -664,25 +1256,21 @@ GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
                          uint64_t length,
                          uint32_t anonymity,
                          enum GNUNET_FS_DownloadOptions options,
+                         void *cctx,
                          struct GNUNET_FS_DownloadContext *parent)
 {
   struct GNUNET_FS_ProgressInfo pi;
   struct GNUNET_FS_DownloadContext *dc;
   struct GNUNET_CLIENT_Connection *client;
 
-  client = GNUNET_CLIENT_connect (h->sched,
-                                 "fs",
-                                 h->cfg);
-  if (NULL == client)
-    return NULL;
-  // FIXME: add support for "loc" URIs!
   GNUNET_assert (GNUNET_FS_uri_test_chk (uri));
   if ( (offset + length < offset) ||
        (offset + length > uri->data.chk.file_length) )
-    {
+    {      
       GNUNET_break (0);
       return NULL;
     }
+  // FIXME: add support for "loc" URIs!
 #if DEBUG_DOWNLOAD
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Starting download `%s' of %llu bytes\n",
@@ -691,10 +1279,17 @@ GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
 #endif
   dc = GNUNET_malloc (sizeof(struct GNUNET_FS_DownloadContext));
   dc->h = h;
-  dc->client = client;
   dc->parent = parent;
+  if (parent != NULL)
+    {
+      GNUNET_CONTAINER_DLL_insert (parent->child_head,
+                                  parent->child_tail,
+                                  dc);
+    }
   dc->uri = GNUNET_FS_uri_dup (uri);
   dc->meta = GNUNET_CONTAINER_meta_data_duplicate (meta);
+  dc->client_info = cctx;
+  dc->start_time = GNUNET_TIME_absolute_get ();
   if (NULL != filename)
     {
       dc->filename = GNUNET_strdup (filename);
@@ -718,7 +1313,6 @@ GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
          GNUNET_CONTAINER_meta_data_destroy (dc->meta);
          GNUNET_FS_uri_destroy (dc->uri);
          GNUNET_free (dc->filename);
-         GNUNET_CLIENT_disconnect (dc->client);
          GNUNET_free (dc);
          return NULL;
        }
@@ -728,7 +1322,7 @@ GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
   dc->length = length;
   dc->anonymity = anonymity;
   dc->options = options;
-  dc->active = GNUNET_CONTAINER_multihashmap_create (1 + (length / DBLOCK_SIZE));
+  dc->active = GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE));
   dc->treedepth = GNUNET_FS_compute_depth (GNUNET_ntohll(dc->uri->data.chk.file_length));
 #if DEBUG_DOWNLOAD
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
@@ -736,15 +1330,16 @@ GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
              dc->treedepth);
 #endif
   // FIXME: make persistent
+  
+  // FIXME: bound parallelism here!
+  client = GNUNET_CLIENT_connect (h->sched,
+                                 "fs",
+                                 h->cfg);
+  dc->client = client;
   schedule_block_download (dc, 
                           &dc->uri->data.chk.chk,
                           0, 
-                          0);
-  GNUNET_CLIENT_notify_transmit_ready (client,
-                                      sizeof (struct SearchMessage),
-                                       GNUNET_CONSTANTS_SERVICE_TIMEOUT,
-                                      &transmit_download_request,
-                                      dc);  
+                          1 /* 0 == CHK, 1 == top */);
   GNUNET_CLIENT_receive (client,
                         &receive_results,
                         dc,
@@ -789,7 +1384,15 @@ GNUNET_FS_download_stop (struct GNUNET_FS_DownloadContext *dc,
 {
   struct GNUNET_FS_ProgressInfo pi;
 
+  while (NULL != dc->child_head)
+    GNUNET_FS_download_stop (dc->child_head, 
+                            do_delete);
   // FIXME: make unpersistent  
+  if (dc->parent != NULL)
+    GNUNET_CONTAINER_DLL_remove (dc->parent->child_head,
+                                dc->parent->child_tail,
+                                dc);
+  
   pi.status = GNUNET_FS_STATUS_DOWNLOAD_STOPPED;
   make_download_status (&pi, dc);
   dc->client_info = dc->h->upcb (dc->h->upcb_cls,
@@ -798,8 +1401,13 @@ GNUNET_FS_download_stop (struct GNUNET_FS_DownloadContext *dc,
   if (GNUNET_SCHEDULER_NO_TASK != dc->task)
     GNUNET_SCHEDULER_cancel (dc->h->sched,
                             dc->task);
+  if (NULL != dc->th)
+    {
+      GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
+      dc->th = NULL;
+    }
   if (NULL != dc->client)
-    GNUNET_CLIENT_disconnect (dc->client);
+    GNUNET_CLIENT_disconnect (dc->client, GNUNET_NO);
   GNUNET_CONTAINER_multihashmap_iterate (dc->active,
                                         &free_entry,
                                         NULL);
@@ -823,61 +1431,4 @@ GNUNET_FS_download_stop (struct GNUNET_FS_DownloadContext *dc,
   GNUNET_free (dc);
 }
 
-
-
-#if 0
-
-
-/**
- * Check if self block is already present on the drive.  If the block
- * is a dblock and present, the ProgressModel is notified. If the
- * block is present and it is an iblock, downloading the children is
- * triggered.
- *
- * Also checks if the block is within the range of blocks
- * that we are supposed to download.  If not, the method
- * returns as if the block is present but does NOT signal
- * progress.
- *
- * @param node that is checked for presence
- * @return GNUNET_YES if present, GNUNET_NO if not.
- */
-static int
-check_node_present (const struct Node *node)
-{
-  int res;
-  int ret;
-  char *data;
-  unsigned int size;
-  GNUNET_HashCode hc;
-
-  size = get_node_size (node);
-  /* first check if node is within range.
-     For now, keeping it simple, we only do
-     this for level-0 nodes */
-  if ((node->level == 0) &&
-      ((node->offset + size < node->ctx->offset) ||
-       (node->offset >= node->ctx->offset + node->ctx->length)))
-    return GNUNET_YES;
-  data = GNUNET_malloc (size);
-  ret = GNUNET_NO;
-  res = read_from_files (node->ctx, node->level, node->offset, data, size);
-  if (res == size)
-    {
-      GNUNET_hash (data, size, &hc);
-      if (0 == memcmp (&hc, &node->chk.key, sizeof (GNUNET_HashCode)))
-        {
-          notify_client_about_progress (node, data, size);
-          if (node->level > 0)
-            iblock_download_children (node, data, size);
-          ret = GNUNET_YES;
-        }
-    }
-  GNUNET_free (data);
-  return ret;
-}
-
-#endif
-
-
 /* end of fs_download.c */