/*
This file is part of GNUnet.
(C) 2001-2012 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
by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
/**
* @file fs/fs_download.c
* @brief download methods
* @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_constants.h"
#include "gnunet_fs_service.h"
#include "fs_api.h"
#include "fs_tree.h"
/**
* Determine if the given download (options and meta data) should cause
* use to try to do a recursive download.
*/
static int
is_recursive_download (struct GNUNET_FS_DownloadContext *dc)
{
return (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_RECURSIVE)) &&
((GNUNET_YES == GNUNET_FS_meta_data_test_for_directory (dc->meta)) ||
((NULL == dc->meta) &&
((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))))));
}
/**
* 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.
*
* @param fsize overall file size
* @param off offset of the block in the file
* @param depth depth of the block in the tree, 0 for DBLOCK
* @return off for DBLOCKS (depth == treedepth),
* otherwise an offset past the end
* of the file that does not overlap
* with the range for any other block
*/
static uint64_t
compute_disk_offset (uint64_t fsize, uint64_t off, unsigned int depth)
{
unsigned int 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 (0 == depth)
return off;
/* first IBlocks start at the end of file, rounded up
* to full DBLOCK_SIZE */
loff = ((fsize + DBLOCK_SIZE - 1) / DBLOCK_SIZE) * DBLOCK_SIZE;
lsize =
((fsize + DBLOCK_SIZE -
1) / DBLOCK_SIZE) * sizeof (struct ContentHashKey);
GNUNET_assert (0 == (off % DBLOCK_SIZE));
ioff = (off / DBLOCK_SIZE);
for (i = 1; i < depth; i++)
{
loff += lsize;
lsize = (lsize + CHK_PER_INODE - 1) / CHK_PER_INODE;
GNUNET_assert (lsize > 0);
GNUNET_assert (0 == (ioff % CHK_PER_INODE));
ioff /= CHK_PER_INODE;
}
return loff + ioff * sizeof (struct ContentHashKey);
}
/**
* Fill in all of the generic fields for a download event and call the
* callback.
*
* @param pi structure to fill in
* @param dc overall download context
*/
void
GNUNET_FS_download_make_status_ (struct GNUNET_FS_ProgressInfo *pi,
struct GNUNET_FS_DownloadContext *dc)
{
pi->value.download.dc = dc;
pi->value.download.cctx = dc->client_info;
pi->value.download.pctx =
(NULL == dc->parent) ? NULL : dc->parent->client_info;
pi->value.download.sctx =
(NULL == dc->search) ? NULL : dc->search->client_info;
pi->value.download.uri = dc->uri;
pi->value.download.filename = dc->filename;
pi->value.download.size = dc->length;
/* FIXME: Fix duration calculation to account for pauses */
pi->value.download.duration =
GNUNET_TIME_absolute_get_duration (dc->start_time);
pi->value.download.completed = dc->completed;
pi->value.download.anonymity = dc->anonymity;
pi->value.download.eta =
GNUNET_TIME_calculate_eta (dc->start_time, dc->completed, dc->length);
pi->value.download.is_active = (NULL == dc->client) ? GNUNET_NO : GNUNET_YES;
pi->fsh = dc->h;
if (0 == (dc->options & GNUNET_FS_DOWNLOAD_IS_PROBE))
dc->client_info = dc->h->upcb (dc->h->upcb_cls, pi);
else
dc->client_info = GNUNET_FS_search_probe_progress_ (NULL, pi);
}
/**
* 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);
/**
* Closure for iterator processing results.
*/
struct ProcessResultClosure
{
/**
* Hash of data.
*/
struct GNUNET_HashCode query;
/**
* Data found in P2P network.
*/
const void *data;
/**
* Our download context.
*/
struct GNUNET_FS_DownloadContext *dc;
/**
* When did we last transmit the request?
*/
struct GNUNET_TIME_Absolute last_transmission;
/**
* Number of bytes in data.
*/
size_t size;
/**
* Type of data.
*/
enum GNUNET_BLOCK_Type type;
/**
* Flag to indicate if this block should be stored on disk.
*/
int do_store;
/**
* how much respect did we offer to get this reply?
*/
uint32_t respect_offered;
/**
* how often did we transmit the query?
*/
uint32_t num_transmissions;
};
/**
* 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 struct GNUNET_HashCode * key,
void *value);
/**
* We've found a matching block without downloading it.
* Encrypt it and pass it to our "receive" function as
* if we had received it from the network.
*
* @param dc download in question
* @param chk request this relates to
* @param dr request details
* @param block plaintext data matching request
* @param len number of bytes in block
* @param do_store should we still store the block on disk?
* @return GNUNET_OK on success
*/
static int
encrypt_existing_match (struct GNUNET_FS_DownloadContext *dc,
const struct ContentHashKey *chk,
struct DownloadRequest *dr, const char *block,
size_t len, int do_store)
{
struct ProcessResultClosure prc;
char enc[len];
struct GNUNET_CRYPTO_SymmetricSessionKey sk;
struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
struct GNUNET_HashCode query;
GNUNET_CRYPTO_hash_to_aes_key (&chk->key, &sk, &iv);
if (-1 == GNUNET_CRYPTO_symmetric_encrypt (block, len, &sk, &iv, enc))
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
GNUNET_CRYPTO_hash (enc, len, &query);
if (0 != memcmp (&query, &chk->query, sizeof (struct GNUNET_HashCode)))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Matching %u byte block for `%s' at offset %llu already present, no need for download!\n",
(unsigned int) len,
dc->filename, (unsigned long long) dr->offset);
/* already got it! */
prc.dc = dc;
prc.data = enc;
prc.size = len;
prc.type =
(0 ==
dr->depth) ? GNUNET_BLOCK_TYPE_FS_DBLOCK : GNUNET_BLOCK_TYPE_FS_IBLOCK;
prc.query = chk->query;
prc.do_store = do_store;
prc.last_transmission = GNUNET_TIME_UNIT_FOREVER_ABS;
process_result_with_request (&prc, &chk->key, dr);
return GNUNET_OK;
}
/**
* We've lost our connection with the FS service.
* Re-establish it and re-transmit all of our
* pending requests.
*
* @param dc download context that is having trouble
*/
static void
try_reconnect (struct GNUNET_FS_DownloadContext *dc);
/**
* We found an entry in a directory. Check if the respective child
* already exists and if not create the respective child download.
*
* @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);
/**
* 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
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 (NULL != dc->filename)
{
h = GNUNET_DISK_file_open (dc->filename, GNUNET_DISK_OPEN_READ,
GNUNET_DISK_PERM_NONE);
}
else
{
GNUNET_assert (NULL != dc->temp_filename);
h = GNUNET_DISK_file_open (dc->temp_filename, GNUNET_DISK_OPEN_READ,
GNUNET_DISK_PERM_NONE);
}
if (NULL == h)
return; /* oops */
data = GNUNET_DISK_file_map (h, &m, GNUNET_DISK_MAP_TYPE_READ, size);
if (NULL == data)
{
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 (NULL == dc->filename)
{
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 (or trigger them if
* necessary) and once we're completely done, signal completion (and
* possibly recurse to parent). This function MUST be called when the
* download of a file itself is done or when the download of a file is
* done and then later a direct child download has completed (and
* hence this download may complete itself).
*
* @param dc download to check for completion of children
*/
static void
check_completed (struct GNUNET_FS_DownloadContext *dc)
{
struct GNUNET_FS_ProgressInfo pi;
struct GNUNET_FS_DownloadContext *pos;
/* first, check if we need to download children */
if ((NULL == dc->child_head) && (is_recursive_download (dc)))
full_recursive_download (dc);
/* then, check if children are done already */
for (pos = dc->child_head; NULL != pos; pos = pos->next)
{
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 */
}
/* All of our children are done, so mark this download done */
dc->has_finished = GNUNET_YES;
if (NULL != dc->job_queue)
{
GNUNET_FS_dequeue_ (dc->job_queue);
dc->job_queue = NULL;
}
if (GNUNET_SCHEDULER_NO_TASK != dc->task)
{
GNUNET_SCHEDULER_cancel (dc->task);
dc->task = GNUNET_SCHEDULER_NO_TASK;
}
if (NULL != dc->rfh)
{
GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (dc->rfh));
dc->rfh = NULL;
}
GNUNET_FS_download_sync_ (dc);
/* signal completion */
pi.status = GNUNET_FS_STATUS_DOWNLOAD_COMPLETED;
GNUNET_FS_download_make_status_ (&pi, dc);
/* let parent know */
if (NULL != dc->parent)
check_completed (dc->parent);
}
/**
* We got a block of plaintext data (from the meta data).
* Try it for upward reconstruction of the data. On success,
* the top-level block will move to state BRS_DOWNLOAD_UP.
*
* @param dc context for the download
* @param dr download request to match against
* @param data plaintext data, starting from the beginning of the file
* @param data_len number of bytes in data
*/
static void
try_match_block (struct GNUNET_FS_DownloadContext *dc,
struct DownloadRequest *dr, const char *data, size_t data_len)
{
struct GNUNET_FS_ProgressInfo pi;
unsigned int i;
char enc[DBLOCK_SIZE];
struct ContentHashKey chks[CHK_PER_INODE];
struct ContentHashKey in_chk;
struct GNUNET_CRYPTO_SymmetricSessionKey sk;
struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
size_t dlen;
struct DownloadRequest *drc;
struct GNUNET_DISK_FileHandle *fh;
int complete;
const char *fn;
const char *odata;
size_t odata_len;
odata = data;
odata_len = data_len;
if (BRS_DOWNLOAD_UP == dr->state)
return;
if (dr->depth > 0)
{
complete = GNUNET_YES;
for (i = 0; i < dr->num_children; i++)
{
drc = dr->children[i];
try_match_block (dc, drc, data, data_len);
if (drc->state != BRS_RECONSTRUCT_META_UP)
complete = GNUNET_NO;
else
chks[i] = drc->chk;
}
if (GNUNET_YES != complete)
return;
data = (const char *) chks;
dlen = dr->num_children * sizeof (struct ContentHashKey);
}
else
{
if (dr->offset > data_len)
return; /* oops */
dlen = GNUNET_MIN (data_len - dr->offset, DBLOCK_SIZE);
}
GNUNET_CRYPTO_hash (&data[dr->offset], dlen, &in_chk.key);
GNUNET_CRYPTO_hash_to_aes_key (&in_chk.key, &sk, &iv);
if (-1 == GNUNET_CRYPTO_symmetric_encrypt (&data[dr->offset], dlen, &sk, &iv, enc))
{
GNUNET_break (0);
return;
}
GNUNET_CRYPTO_hash (enc, dlen, &in_chk.query);
switch (dr->state)
{
case BRS_INIT:
dr->chk = in_chk;
dr->state = BRS_RECONSTRUCT_META_UP;
break;
case BRS_CHK_SET:
if (0 != memcmp (&in_chk, &dr->chk, sizeof (struct ContentHashKey)))
{
/* other peer provided bogus meta data */
GNUNET_break_op (0);
break;
}
/* write block to disk */
fn = (NULL != dc->filename) ? dc->filename : dc->temp_filename;
fh = GNUNET_DISK_file_open (fn,
GNUNET_DISK_OPEN_READWRITE |
GNUNET_DISK_OPEN_CREATE |
GNUNET_DISK_OPEN_TRUNCATE,
GNUNET_DISK_PERM_USER_READ |
GNUNET_DISK_PERM_USER_WRITE |
GNUNET_DISK_PERM_GROUP_READ |
GNUNET_DISK_PERM_OTHER_READ);
if (NULL == fh)
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "open", fn);
GNUNET_asprintf (&dc->emsg, _("Failed to open file `%s' for writing"),
fn);
GNUNET_DISK_file_close (fh);
dr->state = BRS_ERROR;
pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
pi.value.download.specifics.error.message = dc->emsg;
GNUNET_FS_download_make_status_ (&pi, dc);
return;
}
if (data_len != GNUNET_DISK_file_write (fh, odata, odata_len))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "write", fn);
GNUNET_asprintf (&dc->emsg, _("Failed to open file `%s' for writing"),
fn);
GNUNET_DISK_file_close (fh);
dr->state = BRS_ERROR;
pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
pi.value.download.specifics.error.message = dc->emsg;
GNUNET_FS_download_make_status_ (&pi, dc);
return;
}
GNUNET_DISK_file_close (fh);
/* signal success */
dr->state = BRS_DOWNLOAD_UP;
dc->completed = dc->length;
GNUNET_FS_download_sync_ (dc);
pi.status = GNUNET_FS_STATUS_DOWNLOAD_PROGRESS;
pi.value.download.specifics.progress.data = data;
pi.value.download.specifics.progress.offset = 0;
pi.value.download.specifics.progress.data_len = dlen;
pi.value.download.specifics.progress.depth = 0;
pi.value.download.specifics.progress.respect_offered = 0;
pi.value.download.specifics.progress.block_download_duration = GNUNET_TIME_UNIT_ZERO;
GNUNET_FS_download_make_status_ (&pi, dc);
if ((NULL != dc->filename) &&
(0 !=
TRUNCATE (dc->filename,
GNUNET_ntohll (dc->uri->data.chk.file_length))))
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "truncate",
dc->filename);
check_completed (dc);
break;
default:
/* how did we get here? */
GNUNET_break (0);
break;
}
}
/**
* Type of a function that libextractor calls for each
* meta data item found. If we find full data meta data,
* call 'try_match_block' on it.
*
* @param cls our 'struct GNUNET_FS_DownloadContext*'
* @param plugin_name name of the plugin that produced this value;
* special values can be used (i.e. '<zlib>' for zlib being
* used in the main libextractor library and yielding
* meta data).
* @param type libextractor-type describing the meta data
* @param format basic format information about data
* @param data_mime_type mime-type of data (not of the original file);
* can be NULL (if mime-type is not known)
* @param data actual meta-data found
* @param data_len number of bytes in data
* @return 0 to continue extracting, 1 to abort
*/
static int
match_full_data (void *cls, const char *plugin_name,
enum EXTRACTOR_MetaType type, enum EXTRACTOR_MetaFormat format,
const char *data_mime_type, const char *data, size_t data_len)
{
struct GNUNET_FS_DownloadContext *dc = cls;
if (EXTRACTOR_METATYPE_GNUNET_FULL_DATA != type)
return 0;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Found %u bytes of FD!\n",
(unsigned int) data_len);
if (GNUNET_FS_uri_chk_get_file_size (dc->uri) != data_len)
{
GNUNET_break_op (0);
return 1; /* bogus meta data */
}
try_match_block (dc, dc->top_request, data, data_len);
return 1;
}
/**
* Set the state of the given download request to
* BRS_DOWNLOAD_UP and propagate it up the tree.
*
* @param dr download request that is done
*/
static void
propagate_up (struct DownloadRequest *dr)
{
unsigned int i;
do
{
dr->state = BRS_DOWNLOAD_UP;
dr = dr->parent;
if (NULL == dr)
break;
for (i = 0; i < dr->num_children; i++)
if (dr->children[i]->state != BRS_DOWNLOAD_UP)
break;
}
while (i == dr->num_children);
}
/**
* Try top-down reconstruction. Before, the given request node
* must have the state BRS_CHK_SET. Afterwards, more nodes may
* have that state or advanced to BRS_DOWNLOAD_DOWN or even
* BRS_DOWNLOAD_UP. It is also possible to get BRS_ERROR on the
* top level.
*
* @param dc overall download this block belongs to
* @param dr block to reconstruct
*/
static void
try_top_down_reconstruction (struct GNUNET_FS_DownloadContext *dc,
struct DownloadRequest *dr)
{
uint64_t off;
char block[DBLOCK_SIZE];
struct GNUNET_HashCode key;
uint64_t total;
size_t len;
unsigned int i;
struct DownloadRequest *drc;
uint64_t child_block_size;
const struct ContentHashKey *chks;
int up_done;
GNUNET_assert (NULL != dc->rfh);
GNUNET_assert (BRS_CHK_SET == dr->state);
total = GNUNET_FS_uri_chk_get_file_size (dc->uri);
GNUNET_assert (dr->depth < dc->treedepth);
len = GNUNET_FS_tree_calculate_block_size (total, dr->offset, dr->depth);
GNUNET_assert (len <= DBLOCK_SIZE);
off = compute_disk_offset (total, dr->offset, dr->depth);
if (dc->old_file_size < off + len)
return; /* failure */
if (off != GNUNET_DISK_file_seek (dc->rfh, off, GNUNET_DISK_SEEK_SET))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "seek", dc->filename);
return; /* failure */
}
if (len != GNUNET_DISK_file_read (dc->rfh, block, len))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "read", dc->filename);
return; /* failure */
}
GNUNET_CRYPTO_hash (block, len, &key);
if (0 != memcmp (&key, &dr->chk.key, sizeof (struct GNUNET_HashCode)))
return; /* mismatch */
if (GNUNET_OK !=
encrypt_existing_match (dc, &dr->chk, dr, block, len, GNUNET_NO))
{
/* hash matches but encrypted block does not, really bad */
dr->state = BRS_ERROR;
/* propagate up */
while (NULL != dr->parent)
{
dr = dr->parent;
dr->state = BRS_ERROR;
}
return;
}
/* block matches */
dr->state = BRS_DOWNLOAD_DOWN;
/* set CHKs for children */
up_done = GNUNET_YES;
chks = (const struct ContentHashKey *) block;
for (i = 0; i < dr->num_children; i++)
{
drc = dr->children[i];
GNUNET_assert (drc->offset >= dr->offset);
child_block_size = GNUNET_FS_tree_compute_tree_size (drc->depth);
GNUNET_assert (0 == (drc->offset - dr->offset) % child_block_size);
if (BRS_INIT == drc->state)
{
drc->state = BRS_CHK_SET;
drc->chk = chks[drc->chk_idx];
try_top_down_reconstruction (dc, drc);
}
if (BRS_DOWNLOAD_UP != drc->state)
up_done = GNUNET_NO; /* children not all done */
}
if (GNUNET_YES == up_done)
propagate_up (dr); /* children all done (or no children...) */
}
/**
* Schedule the download of the specified block in the tree.
*
* @param dc overall download this block belongs to
* @param dr request to schedule
*/
static void
schedule_block_download (struct GNUNET_FS_DownloadContext *dc,
struct DownloadRequest *dr)
{
unsigned int i;
switch (dr->state)
{
case BRS_INIT:
GNUNET_assert (0);
break;
case BRS_RECONSTRUCT_DOWN:
GNUNET_assert (0);
break;
case BRS_RECONSTRUCT_META_UP:
GNUNET_assert (0);
break;
case BRS_RECONSTRUCT_UP:
GNUNET_assert (0);
break;
case BRS_CHK_SET:
/* normal case, start download */
break;
case BRS_DOWNLOAD_DOWN:
for (i = 0; i < dr->num_children; i++)
schedule_block_download (dc, dr->children[i]);
return;
case BRS_DOWNLOAD_UP:
/* We're done! */
return;
case BRS_ERROR:
GNUNET_break (0);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Scheduling download at offset %llu and depth %u for `%s'\n",
(unsigned long long) dr->offset, dr->depth,
GNUNET_h2s (&dr->chk.query));
if (GNUNET_NO !=
GNUNET_CONTAINER_multihashmap_contains_value (dc->active, &dr->chk.query,
dr))
return; /* already active */
GNUNET_CONTAINER_multihashmap_put (dc->active, &dr->chk.query, dr,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
if (NULL == dc->client)
return; /* download not active */
GNUNET_CONTAINER_DLL_insert (dc->pending_head, dc->pending_tail, dr);
dr->is_pending = GNUNET_YES;
if (NULL == dc->th)
dc->th =
GNUNET_CLIENT_notify_transmit_ready (dc->client,
sizeof (struct SearchMessage),
GNUNET_CONSTANTS_SERVICE_TIMEOUT,
GNUNET_NO,
&transmit_download_request, dc);
}
#define GNUNET_FS_URI_CHK_PREFIX GNUNET_FS_URI_PREFIX GNUNET_FS_URI_CHK_INFIX
/**
* We found an entry in a directory. Check if the respective child
* already exists and if not create the respective child download.
*
* @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;
char *temp_name;
char *fn;
char *us;
char *ext;
char *dn;
char *pos;
char *full_name;
char *sfn;
if (NULL == uri)
return; /* entry for the directory itself */
cpos = dc->child_head;
while (NULL != cpos)
{
if ((GNUNET_FS_uri_test_equal (uri, cpos->uri)) ||
((NULL != filename) && (0 == strcmp (cpos->filename, filename))))
break;
cpos = cpos->next;
}
if (NULL != cpos)
return; /* already exists */
fn = NULL;
if (NULL == filename)
{
fn = GNUNET_FS_meta_data_suggest_filename (meta);
if (NULL == fn)
{
us = GNUNET_FS_uri_to_string (uri);
fn = GNUNET_strdup (&us[strlen (GNUNET_FS_URI_CHK_PREFIX)]);
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_CHK_PREFIX)],
ext);
GNUNET_free (ext);
GNUNET_free (us);
}
/* change '\' to '/' (this should have happened
* during insertion, but malicious peers may
* not have done this) */
while (NULL != (pos = strstr (fn, "\\")))
*pos = '/';
/* remove '../' everywhere (again, well-behaved
* peers don't do this, but don't trust that
* we did not get something nasty) */
while (NULL != (pos = strstr (fn, "../")))
{
pos[0] = '_';
pos[1] = '_';
pos[2] = '_';
}
filename = fn;
}
if (NULL == dc->filename)
{
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)));
sfn = GNUNET_strdup (filename);
while ((strlen (sfn) > 0) && ('/' == filename[strlen (sfn) - 1]))
sfn[strlen (sfn) - 1] = '\0';
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, sfn,
GNUNET_FS_DIRECTORY_EXT);
}
else
{
GNUNET_asprintf (&full_name, "%s%s%s", dn, DIR_SEPARATOR_STR, sfn);
}
GNUNET_free (sfn);
GNUNET_free (dn);
}
if ((NULL != full_name) &&
(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;
}
temp_name = NULL;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Triggering recursive download of size %llu with %u bytes MD\n",
(unsigned long long) GNUNET_FS_uri_chk_get_file_size (uri),
(unsigned int)
GNUNET_CONTAINER_meta_data_get_serialized_size (meta));
GNUNET_FS_download_start (dc->h, uri, meta, full_name, temp_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 (temp_name);
GNUNET_free_non_null (fn);
}
/**
* (recursively) free download request structure
*
* @param dr request to free
*/
void
GNUNET_FS_free_download_request_ (struct DownloadRequest *dr)
{
unsigned int i;
if (NULL == dr)
return;
for (i = 0; i < dr->num_children; i++)
GNUNET_FS_free_download_request_ (dr->children[i]);
GNUNET_free_non_null (dr->children);
GNUNET_free (dr);
}
/**
* 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 struct GNUNET_HashCode * key,
void *value)
{
struct ProcessResultClosure *prc = cls;
struct DownloadRequest *dr = value;
struct GNUNET_FS_DownloadContext *dc = prc->dc;
struct DownloadRequest *drc;
struct GNUNET_DISK_FileHandle *fh = NULL;
struct GNUNET_CRYPTO_SymmetricSessionKey skey;
struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
char pt[prc->size];
struct GNUNET_FS_ProgressInfo pi;
uint64_t off;
size_t bs;
size_t app;
int i;
struct ContentHashKey *chkarr;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Received %u byte block `%s' matching pending request at depth %u and offset %llu/%llu\n",
(unsigned int) prc->size,
GNUNET_h2s (key), dr->depth, (unsigned long long) dr->offset,
(unsigned long long) GNUNET_ntohll (dc->uri->data.
chk.file_length));
bs = GNUNET_FS_tree_calculate_block_size (GNUNET_ntohll
(dc->uri->data.chk.file_length),
dr->offset, dr->depth);
if (prc->size != bs)
{
GNUNET_asprintf (&dc->emsg,
_
("Internal error or bogus download URI (expected %u bytes at depth %u and offset %llu/%llu, got %u bytes)"),
bs, dr->depth, (unsigned long long) dr->offset,
(unsigned long long) GNUNET_ntohll (dc->uri->data.
chk.file_length),
prc->size);
GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "%s\n", dc->emsg);
while (NULL != dr->parent)
{
dr->state = BRS_ERROR;
dr = dr->parent;
}
dr->state = BRS_ERROR;
goto signal_error;
}
(void) GNUNET_CONTAINER_multihashmap_remove (dc->active, &prc->query, dr);
if (GNUNET_YES == dr->is_pending)
{
GNUNET_CONTAINER_DLL_remove (dc->pending_head, dc->pending_tail, dr);
dr->is_pending = GNUNET_NO;
}
GNUNET_CRYPTO_hash_to_aes_key (&dr->chk.key, &skey, &iv);
if (-1 == GNUNET_CRYPTO_symmetric_decrypt (prc->data, prc->size, &skey, &iv, pt))
{
GNUNET_break (0);
dc->emsg = GNUNET_strdup (_("internal error decrypting content"));
goto signal_error;
}
off =
compute_disk_offset (GNUNET_ntohll (dc->uri->data.chk.file_length),
dr->offset, dr->depth);
/* save to disk */
if ((GNUNET_YES == prc->do_store) &&
((NULL != dc->filename) || (is_recursive_download (dc))) &&
((dr->depth == dc->treedepth) ||
(0 == (dc->options & GNUNET_FS_DOWNLOAD_NO_TEMPORARIES))))
{
fh = GNUNET_DISK_file_open (NULL != dc->filename
? dc->filename : dc->temp_filename,
GNUNET_DISK_OPEN_READWRITE |
GNUNET_DISK_OPEN_CREATE,
GNUNET_DISK_PERM_USER_READ |
GNUNET_DISK_PERM_USER_WRITE |
GNUNET_DISK_PERM_GROUP_READ |
GNUNET_DISK_PERM_OTHER_READ);
if (NULL == fh)
{
GNUNET_asprintf (&dc->emsg,
_("Download failed: could not open file `%s': %s"),
dc->filename, STRERROR (errno));
goto signal_error;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Saving decrypted block to disk at offset %llu\n",
(unsigned long long) off);
if ((off != GNUNET_DISK_file_seek (fh, off, GNUNET_DISK_SEEK_SET)))
{
GNUNET_asprintf (&dc->emsg,
_("Failed to seek to offset %llu in file `%s': %s"),
(unsigned long long) off, dc->filename,
STRERROR (errno));
goto signal_error;
}
if (prc->size != GNUNET_DISK_file_write (fh, pt, prc->size))
{
GNUNET_asprintf (&dc->emsg,
_
("Failed to write block of %u bytes at offset %llu in file `%s': %s"),
(unsigned int) prc->size, (unsigned long long) off,
dc->filename, STRERROR (errno));
goto signal_error;
}
GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fh));
fh = NULL;
}
if (0 == dr->depth)
{
/* DBLOCK, update progress and try recursion if applicable */
app = prc->size;
if (dr->offset < dc->offset)
{
/* starting offset begins in the middle of pt,
* do not count first bytes as progress */
GNUNET_assert (app > (dc->offset - dr->offset));
app -= (dc->offset - dr->offset);
}
if (dr->offset + prc->size > dc->offset + dc->length)
{
/* end of block is after relevant range,
* do not count last bytes as progress */
GNUNET_assert (app >
(dr->offset + prc->size) - (dc->offset + dc->length));
app -= (dr->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 (is_recursive_download (dc))
GNUNET_FS_directory_list_contents (prc->size, pt, off,
&trigger_recursive_download, dc);
}
GNUNET_assert (dc->completed <= dc->length);
dr->state = BRS_DOWNLOAD_DOWN;
pi.status = GNUNET_FS_STATUS_DOWNLOAD_PROGRESS;
pi.value.download.specifics.progress.data = pt;
pi.value.download.specifics.progress.offset = dr->offset;
pi.value.download.specifics.progress.data_len = prc->size;
pi.value.download.specifics.progress.depth = dr->depth;
pi.value.download.specifics.progress.respect_offered = prc->respect_offered;
pi.value.download.specifics.progress.num_transmissions = prc->num_transmissions;
if (prc->last_transmission.abs_value_us != GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us)
pi.value.download.specifics.progress.block_download_duration
= GNUNET_TIME_absolute_get_duration (prc->last_transmission);
else
pi.value.download.specifics.progress.block_download_duration
= GNUNET_TIME_UNIT_ZERO; /* found locally */
GNUNET_FS_download_make_status_ (&pi, dc);
if (0 == dr->depth)
propagate_up (dr);
if (dc->completed == dc->length)
{
/* download completed, signal */
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));
/* truncate file to size (since we store IBlocks at the end) */
if (NULL != dc->filename)
{
if (0 !=
TRUNCATE (dc->filename,
GNUNET_ntohll (dc->uri->data.chk.file_length)))
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "truncate",
dc->filename);
}
GNUNET_assert (0 == dr->depth);
check_completed (dc);
}
if (0 == dr->depth)
{
/* bottom of the tree, no child downloads possible, just sync */
GNUNET_FS_download_sync_ (dc);
return GNUNET_YES;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Triggering downloads of children (this block was at depth %u and offset %llu)\n",
dr->depth, (unsigned long long) dr->offset);
GNUNET_assert (0 == (prc->size % sizeof (struct ContentHashKey)));
chkarr = (struct ContentHashKey *) pt;
for (i = dr->num_children - 1; i >= 0; i--)
{
drc = dr->children[i];
switch (drc->state)
{
case BRS_INIT:
if ((drc->chk_idx + 1) * sizeof (struct ContentHashKey) > prc->size)
{
/* 'chkarr' does not have enough space for this chk_idx;
internal error! */
GNUNET_break (0); GNUNET_assert (0);
dc->emsg = GNUNET_strdup (_("internal error decoding tree"));
goto signal_error;
}
drc->chk = chkarr[drc->chk_idx];
drc->state = BRS_CHK_SET;
if (GNUNET_YES == dc->issue_requests)
schedule_block_download (dc, drc);
break;
case BRS_RECONSTRUCT_DOWN:
GNUNET_assert (0);
break;
case BRS_RECONSTRUCT_META_UP:
GNUNET_assert (0);
break;
case BRS_RECONSTRUCT_UP:
GNUNET_assert (0);
break;
case BRS_CHK_SET:
GNUNET_assert (0);
break;
case BRS_DOWNLOAD_DOWN:
GNUNET_assert (0);
break;
case BRS_DOWNLOAD_UP:
GNUNET_assert (0);
break;
case BRS_ERROR:
GNUNET_assert (0);
break;
default:
GNUNET_assert (0);
break;
}
}
GNUNET_FS_download_sync_ (dc);
return GNUNET_YES;
signal_error:
if (NULL != fh)
GNUNET_DISK_file_close (fh);
pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
pi.value.download.specifics.error.message = dc->emsg;
GNUNET_FS_download_make_status_ (&pi, dc);
/* abort all pending requests */
if (NULL != dc->th)
{
GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
dc->th = NULL;
}
GNUNET_CLIENT_disconnect (dc->client);
dc->in_receive = GNUNET_NO;
dc->client = NULL;
GNUNET_FS_free_download_request_ (dc->top_request);
dc->top_request = NULL;
GNUNET_CONTAINER_multihashmap_destroy (dc->active);
dc->active = NULL;
if (NULL != dc->job_queue)
{
GNUNET_FS_dequeue_ (dc->job_queue);
dc->job_queue = NULL;
}
dc->pending_head = NULL;
dc->pending_tail = NULL;
GNUNET_FS_download_sync_ (dc);
return GNUNET_NO;
}
/**
* Process a download result.
*
* @param dc our download context
* @param type type of the result
* @param respect_offered how much respect did we offer to get this reply?
* @param num_transmissions how often did we transmit the query?
* @param last_transmission when was this block requested the last time? (FOREVER if unknown/not applicable)
* @param data the (encrypted) response
* @param size size of data
*/
static void
process_result (struct GNUNET_FS_DownloadContext *dc,
enum GNUNET_BLOCK_Type type,
uint32_t respect_offered,
uint32_t num_transmissions,
struct GNUNET_TIME_Absolute last_transmission,
const void *data, size_t size)
{
struct ProcessResultClosure prc;
prc.dc = dc;
prc.data = data;
prc.last_transmission = last_transmission;
prc.size = size;
prc.type = type;
prc.do_store = GNUNET_YES;
prc.respect_offered = respect_offered;
prc.num_transmissions = num_transmissions;
GNUNET_CRYPTO_hash (data, size, &prc.query);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Received result for query `%s' from `%s'-service\n",
GNUNET_h2s (&prc.query), "FS");
GNUNET_CONTAINER_multihashmap_get_multiple (dc->active, &prc.query,
&process_result_with_request,
&prc);
}
/**
* Type of a function to call when we receive a message
* from the service.
*
* @param cls closure
* @param msg message received, NULL on timeout or fatal error
*/
static void
receive_results (void *cls, const struct GNUNET_MessageHeader *msg)
{
struct GNUNET_FS_DownloadContext *dc = cls;
const struct ClientPutMessage *cm;
uint16_t msize;
if ((NULL == msg) || (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_FS_PUT) ||
(sizeof (struct ClientPutMessage) > ntohs (msg->size)))
{
GNUNET_break (NULL == msg);
try_reconnect (dc);
return;
}
msize = ntohs (msg->size);
cm = (const struct ClientPutMessage *) msg;
process_result (dc, ntohl (cm->type),
ntohl (cm->respect_offered),
ntohl (cm->num_transmissions),
GNUNET_TIME_absolute_ntoh (cm->last_transmission), &cm[1],
msize - sizeof (struct ClientPutMessage));
if (NULL == dc->client)
return; /* fatal error */
/* continue receiving */
GNUNET_CLIENT_receive (dc->client, &receive_results, dc,
GNUNET_TIME_UNIT_FOREVER_REL);
}
/**
* 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)
{
struct GNUNET_FS_DownloadContext *dc = cls;
size_t msize;
struct SearchMessage *sm;
struct DownloadRequest *dr;
dc->th = NULL;
if (NULL == buf)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Transmitting download request failed, trying to reconnect\n");
try_reconnect (dc);
return 0;
}
GNUNET_assert (size >= sizeof (struct SearchMessage));
msize = 0;
sm = buf;
while ((NULL != (dr = dc->pending_head)) &&
(size >= msize + sizeof (struct SearchMessage)))
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Transmitting download request for `%s' to `%s'-service\n",
GNUNET_h2s (&dr->chk.query), "FS");
memset (sm, 0, sizeof (struct SearchMessage));
sm->header.size = htons (sizeof (struct SearchMessage));
sm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_START_SEARCH);
if (0 != (dc->options & GNUNET_FS_DOWNLOAD_OPTION_LOOPBACK_ONLY))
sm->options = htonl (GNUNET_FS_SEARCH_OPTION_LOOPBACK_ONLY);
else
sm->options = htonl (GNUNET_FS_SEARCH_OPTION_NONE);
if (0 == dr->depth)
sm->type = htonl (GNUNET_BLOCK_TYPE_FS_DBLOCK);
else
sm->type = htonl (GNUNET_BLOCK_TYPE_FS_IBLOCK);
sm->anonymity_level = htonl (dc->anonymity);
sm->target = dc->target;
sm->query = dr->chk.query;
GNUNET_CONTAINER_DLL_remove (dc->pending_head, dc->pending_tail, dr);
dr->is_pending = GNUNET_NO;
msize += sizeof (struct SearchMessage);
sm++;
}
if (NULL != dc->pending_head)
{
dc->th =
GNUNET_CLIENT_notify_transmit_ready (dc->client,
sizeof (struct SearchMessage),
GNUNET_CONSTANTS_SERVICE_TIMEOUT,
GNUNET_NO,
&transmit_download_request, dc);
GNUNET_assert (NULL != dc->th);
}
if (GNUNET_NO == dc->in_receive)
{
dc->in_receive = GNUNET_YES;
GNUNET_CLIENT_receive (dc->client, &receive_results, dc,
GNUNET_TIME_UNIT_FOREVER_REL);
}
return msize;
}
/**
* Reconnect to the FS service and transmit our queries NOW.
*
* @param cls our download context
* @param tc unused
*/
static void
do_reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct GNUNET_FS_DownloadContext *dc = cls;
struct GNUNET_CLIENT_Connection *client;
dc->task = GNUNET_SCHEDULER_NO_TASK;
client = GNUNET_CLIENT_connect ("fs", 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;
if (NULL != dc->pending_head)
{
dc->th =
GNUNET_CLIENT_notify_transmit_ready (client,
sizeof (struct SearchMessage),
GNUNET_CONSTANTS_SERVICE_TIMEOUT,
GNUNET_NO,
&transmit_download_request, dc);
GNUNET_assert (NULL != dc->th);
}
}
/**
* Add entries to the pending list.
*
* @param cls our download context
* @param key unused
* @param entry entry of type "struct DownloadRequest"
* @return GNUNET_OK
*/
static int
retry_entry (void *cls, const struct GNUNET_HashCode * key, void *entry)
{
struct GNUNET_FS_DownloadContext *dc = cls;
struct DownloadRequest *dr = entry;
dr->next = NULL;
dr->prev = NULL;
GNUNET_CONTAINER_DLL_insert (dc->pending_head, dc->pending_tail, dr);
dr->is_pending = GNUNET_YES;
return GNUNET_OK;
}
/**
* We've lost our connection with the FS service.
* Re-establish it and re-transmit all of our
* pending requests.
*
* @param dc download context that is having trouble
*/
static void
try_reconnect (struct GNUNET_FS_DownloadContext *dc)
{
if (NULL != dc->client)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Moving all requests back to pending list\n");
if (NULL != dc->th)
{
GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
dc->th = NULL;
}
/* full reset of the pending list */
dc->pending_head = NULL;
dc->pending_tail = NULL;
GNUNET_CONTAINER_multihashmap_iterate (dc->active, &retry_entry, dc);
GNUNET_CLIENT_disconnect (dc->client);
dc->in_receive = GNUNET_NO;
dc->client = NULL;
}
if (0 == dc->reconnect_backoff.rel_value_us)
dc->reconnect_backoff = GNUNET_TIME_UNIT_MILLISECONDS;
else
dc->reconnect_backoff = GNUNET_TIME_STD_BACKOFF (dc->reconnect_backoff);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Will try to reconnect in %s\n",
GNUNET_STRINGS_relative_time_to_string (dc->reconnect_backoff, GNUNET_YES));
dc->task =
GNUNET_SCHEDULER_add_delayed (dc->reconnect_backoff,
&do_reconnect,
dc);
}
/**
* We're allowed to ask the FS service for our blocks. Start the download.
*
* @param cls the 'struct GNUNET_FS_DownloadContext'
* @param client handle to use for communcation with FS (we must destroy it!)
*/
static void
activate_fs_download (void *cls, struct GNUNET_CLIENT_Connection *client)
{
struct GNUNET_FS_DownloadContext *dc = cls;
struct GNUNET_FS_ProgressInfo pi;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Download activated\n");
GNUNET_assert (NULL != client);
GNUNET_assert (NULL == dc->client);
GNUNET_assert (NULL == dc->th);
GNUNET_assert (NULL != dc->active);
dc->client = client;
pi.status = GNUNET_FS_STATUS_DOWNLOAD_ACTIVE;
GNUNET_FS_download_make_status_ (&pi, dc);
dc->pending_head = NULL;
dc->pending_tail = NULL;
GNUNET_CONTAINER_multihashmap_iterate (dc->active, &retry_entry, dc);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Asking for transmission to FS service\n");
if (NULL != dc->pending_head)
{
dc->th =
GNUNET_CLIENT_notify_transmit_ready (dc->client,
sizeof (struct SearchMessage),
GNUNET_CONSTANTS_SERVICE_TIMEOUT,
GNUNET_NO,
&transmit_download_request, dc);
GNUNET_assert (NULL != dc->th);
}
}
/**
* We must stop to ask the FS service for our blocks. Pause the download.
*
* @param cls the `struct GNUNET_FS_DownloadContext`
*/
static void
deactivate_fs_download (void *cls)
{
struct GNUNET_FS_DownloadContext *dc = cls;
struct GNUNET_FS_ProgressInfo pi;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Download deactivated\n");
if (NULL != dc->th)
{
GNUNET_CLIENT_notify_transmit_ready_cancel (dc->th);
dc->th = NULL;
}
if (NULL != dc->client)
{
GNUNET_CLIENT_disconnect (dc->client);
dc->in_receive = GNUNET_NO;
dc->client = NULL;
}
dc->pending_head = NULL;
dc->pending_tail = NULL;
pi.status = GNUNET_FS_STATUS_DOWNLOAD_INACTIVE;
GNUNET_FS_download_make_status_ (&pi, dc);
}
/**
* (recursively) Create a download request structure.
*
* @param parent parent of the current entry
* @param chk_idx index of the chk for this block in the parent block
* @param depth depth of the current entry, 0 are the DBLOCKs,
* top level block is 'dc->treedepth - 1'
* @param dr_offset offset in the original file this block maps to
* (as in, offset of the first byte of the first DBLOCK
* in the subtree rooted in the returned download request tree)
* @param file_start_offset desired starting offset for the download
* in the original file; requesting tree should not contain
* DBLOCKs prior to the file_start_offset
* @param desired_length desired number of bytes the user wanted to access
* (from file_start_offset). Resulting tree should not contain
* DBLOCKs after file_start_offset + file_length.
* @return download request tree for the given range of DBLOCKs at
* the specified depth
*/
static struct DownloadRequest *
create_download_request (struct DownloadRequest *parent,
unsigned int chk_idx,
unsigned int depth,
uint64_t dr_offset, uint64_t file_start_offset,
uint64_t desired_length)
{
struct DownloadRequest *dr;
unsigned int i;
unsigned int head_skip;
uint64_t child_block_size;
dr = GNUNET_malloc (sizeof (struct DownloadRequest));
dr->parent = parent;
dr->depth = depth;
dr->offset = dr_offset;
dr->chk_idx = chk_idx;
if (0 == depth)
return dr;
child_block_size = GNUNET_FS_tree_compute_tree_size (depth - 1);
/* calculate how many blocks at this level are not interesting
* from the start (rounded down), either because of the requested
* file offset or because this IBlock is further along */
if (dr_offset < file_start_offset)
{
head_skip = (file_start_offset - dr_offset) / child_block_size;
}
else
{
head_skip = 0;
}
/* calculate index of last block at this level that is interesting (rounded up) */
dr->num_children = (file_start_offset + desired_length - dr_offset) / child_block_size;
if (dr->num_children * child_block_size <
file_start_offset + desired_length - dr_offset)
dr->num_children++; /* round up */
GNUNET_assert (dr->num_children > head_skip);
dr->num_children -= head_skip;
if (dr->num_children > CHK_PER_INODE)
dr->num_children = CHK_PER_INODE; /* cap at max */
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Block at offset %llu and depth %u has %u children\n",
(unsigned long long) dr_offset,
depth,
dr->num_children);
/* now we can get the total number of *interesting* children for this block */
/* why else would we have gotten here to begin with? (that'd be a bad logic error) */
GNUNET_assert (dr->num_children > 0);
dr->children =
GNUNET_malloc (dr->num_children * sizeof (struct DownloadRequest *));
for (i = 0; i < dr->num_children; i++)
{
dr->children[i] =
create_download_request (dr, i + head_skip, depth - 1,
dr_offset + (i + head_skip) * child_block_size,
file_start_offset, desired_length);
}
return dr;
}
/**
* Continuation after a possible attempt to reconstruct
* the current IBlock from the existing file.
*
* @param cls the 'struct ReconstructContext'
* @param tc scheduler context
*/
static void
reconstruct_cont (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct GNUNET_FS_DownloadContext *dc = cls;
/* clean up state from tree encoder */
if (dc->task != GNUNET_SCHEDULER_NO_TASK)
{
GNUNET_SCHEDULER_cancel (dc->task);
dc->task = GNUNET_SCHEDULER_NO_TASK;
}
if (NULL != dc->rfh)
{
GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (dc->rfh));
dc->rfh = NULL;
}
/* start "normal" download */
dc->issue_requests = GNUNET_YES;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Starting normal download\n");
schedule_block_download (dc, dc->top_request);
}
/**
* Task requesting the next block from the tree encoder.
*
* @param cls the 'struct GNUJNET_FS_DownloadContext' we're processing
* @param tc task context
*/
static void
get_next_block (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct GNUNET_FS_DownloadContext *dc = cls;
dc->task = GNUNET_SCHEDULER_NO_TASK;
GNUNET_FS_tree_encoder_next (dc->te);
}
/**
* Function called asking for the current (encoded)
* block to be processed. After processing the
* client should either call "GNUNET_FS_tree_encode_next"
* or (on error) "GNUNET_FS_tree_encode_finish".
*
* This function checks if the content on disk matches
* the expected content based on the URI.
*
* @param cls closure
* @param chk content hash key for the block
* @param offset offset of the block
* @param depth depth of the block, 0 for DBLOCK
* @param type type of the block (IBLOCK or DBLOCK)
* @param block the (encrypted) block
* @param block_size size of block (in bytes)
*/
static void
reconstruct_cb (void *cls, const struct ContentHashKey *chk, uint64_t offset,
unsigned int depth, enum GNUNET_BLOCK_Type type,
const void *block, uint16_t block_size)
{
struct GNUNET_FS_DownloadContext *dc = cls;
struct GNUNET_FS_ProgressInfo pi;
struct DownloadRequest *dr;
uint64_t blen;
unsigned int chld;
/* find corresponding request entry */
dr = dc->top_request;
while (dr->depth > depth)
{
GNUNET_assert (dr->num_children > 0);
blen = GNUNET_FS_tree_compute_tree_size (dr->depth - 1);
chld = (offset - dr->offset) / blen;
if (chld < dr->children[0]->chk_idx)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Block %u < %u irrelevant for our range\n",
chld,
dr->children[0]->chk_idx);
dc->task = GNUNET_SCHEDULER_add_now (&get_next_block, dc);
return; /* irrelevant block */
}
if (chld > dr->children[dr->num_children-1]->chk_idx)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Block %u > %u irrelevant for our range\n",
chld,
dr->children[dr->num_children-1]->chk_idx);
dc->task = GNUNET_SCHEDULER_add_now (&get_next_block, dc);
return; /* irrelevant block */
}
dr = dr->children[chld - dr->children[0]->chk_idx];
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Matched TE block with request at offset %llu and depth %u in state %d\n",
(unsigned long long) dr->offset,
dr->depth,
dr->state);
/* FIXME: this code needs more testing and might
need to handle more states... */
switch (dr->state)
{
case BRS_INIT:
break;
case BRS_RECONSTRUCT_DOWN:
break;
case BRS_RECONSTRUCT_META_UP:
break;
case BRS_RECONSTRUCT_UP:
break;
case BRS_CHK_SET:
if (0 == memcmp (chk, &dr->chk, sizeof (struct ContentHashKey)))
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Reconstruction succeeded, can use block at offset %llu, depth %u\n",
(unsigned long long) offset,
depth);
/* block matches, hence tree below matches;
* this request is done! */
dr->state = BRS_DOWNLOAD_UP;
(void) GNUNET_CONTAINER_multihashmap_remove (dc->active, &dr->chk.query, dr);
if (GNUNET_YES == dr->is_pending)
{
GNUNET_break (0); /* how did we get here? */
GNUNET_CONTAINER_DLL_remove (dc->pending_head, dc->pending_tail, dr);
dr->is_pending = GNUNET_NO;
}
/* calculate how many bytes of payload this block
* corresponds to */
blen = GNUNET_FS_tree_compute_tree_size (dr->depth);
/* how many of those bytes are in the requested range? */
blen = GNUNET_MIN (blen, dc->length + dc->offset - dr->offset);
/* signal progress */
dc->completed += blen;
pi.status = GNUNET_FS_STATUS_DOWNLOAD_PROGRESS;
pi.value.download.specifics.progress.data = NULL;
pi.value.download.specifics.progress.offset = offset;
pi.value.download.specifics.progress.data_len = 0;
pi.value.download.specifics.progress.depth = 0;
pi.value.download.specifics.progress.respect_offered = 0;
pi.value.download.specifics.progress.block_download_duration = GNUNET_TIME_UNIT_ZERO;
GNUNET_FS_download_make_status_ (&pi, dc);
/* FIXME: duplicated code from 'process_result_with_request - refactor */
if (dc->completed == dc->length)
{
/* download completed, signal */
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));
/* truncate file to size (since we store IBlocks at the end) */
if (NULL != dc->filename)
{
if (0 !=
TRUNCATE (dc->filename,
GNUNET_ntohll (dc->uri->data.chk.file_length)))
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "truncate",
dc->filename);
}
}
}
else
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Reconstruction failed, need to download block at offset %llu, depth %u\n",
(unsigned long long) offset,
depth);
break;
case BRS_DOWNLOAD_DOWN:
break;
case BRS_DOWNLOAD_UP:
break;
case BRS_ERROR:
break;
default:
GNUNET_assert (0);
break;
}
dc->task = GNUNET_SCHEDULER_add_now (&get_next_block, dc);
if ((dr == dc->top_request) && (dr->state == BRS_DOWNLOAD_UP))
check_completed (dc);
}
/**
* Function called by the tree encoder to obtain a block of plaintext
* data (for the lowest level of the tree).
*
* @param cls our 'struct ReconstructContext'
* @param offset identifies which block to get
* @param max (maximum) number of bytes to get; returning
* fewer will also cause errors
* @param buf where to copy the plaintext buffer
* @param emsg location to store an error message (on error)
* @return number of bytes copied to buf, 0 on error
*/
static size_t
fh_reader (void *cls, uint64_t offset, size_t max, void *buf, char **emsg)
{
struct GNUNET_FS_DownloadContext *dc = cls;
struct GNUNET_DISK_FileHandle *fh = dc->rfh;
ssize_t ret;
if (NULL != emsg)
*emsg = NULL;
if (offset != GNUNET_DISK_file_seek (fh, offset, GNUNET_DISK_SEEK_SET))
{
if (NULL != emsg)
*emsg = GNUNET_strdup (strerror (errno));
return 0;
}
ret = GNUNET_DISK_file_read (fh, buf, max);
if (ret < 0)
{
if (NULL != emsg)
*emsg = GNUNET_strdup (strerror (errno));
return 0;
}
return ret;
}
/**
* Task that creates the initial (top-level) download
* request for the file.
*
* @param cls the 'struct GNUNET_FS_DownloadContext'
* @param tc scheduler context
*/
void
GNUNET_FS_download_start_task_ (void *cls,
const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct GNUNET_FS_DownloadContext *dc = cls;
struct GNUNET_FS_ProgressInfo pi;
struct GNUNET_DISK_FileHandle *fh;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Start task running...\n");
dc->task = GNUNET_SCHEDULER_NO_TASK;
if (0 == dc->length)
{
/* no bytes required! */
if (NULL != dc->filename)
{
fh = GNUNET_DISK_file_open (dc->filename,
GNUNET_DISK_OPEN_READWRITE |
GNUNET_DISK_OPEN_CREATE |
((0 ==
GNUNET_FS_uri_chk_get_file_size (dc->uri)) ?
GNUNET_DISK_OPEN_TRUNCATE : 0),
GNUNET_DISK_PERM_USER_READ |
GNUNET_DISK_PERM_USER_WRITE |
GNUNET_DISK_PERM_GROUP_READ |
GNUNET_DISK_PERM_OTHER_READ);
GNUNET_DISK_file_close (fh);
}
GNUNET_FS_download_sync_ (dc);
pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
pi.value.download.specifics.start.meta = dc->meta;
GNUNET_FS_download_make_status_ (&pi, dc);
check_completed (dc);
return;
}
if (NULL != dc->emsg)
return;
if (NULL == dc->top_request)
{
dc->top_request =
create_download_request (NULL, 0, dc->treedepth - 1, 0, dc->offset,
dc->length);
dc->top_request->state = BRS_CHK_SET;
dc->top_request->chk =
(dc->uri->type ==
GNUNET_FS_URI_CHK) ? dc->uri->data.chk.chk : dc->uri->data.loc.fi.chk;
/* signal start */
GNUNET_FS_download_sync_ (dc);
if (NULL != dc->search)
GNUNET_FS_search_result_sync_ (dc->search);
pi.status = GNUNET_FS_STATUS_DOWNLOAD_START;
pi.value.download.specifics.start.meta = dc->meta;
GNUNET_FS_download_make_status_ (&pi, dc);
}
GNUNET_FS_download_start_downloading_ (dc);
/* attempt reconstruction from disk */
if (GNUNET_YES == GNUNET_DISK_file_test (dc->filename))
dc->rfh =
GNUNET_DISK_file_open (dc->filename, GNUNET_DISK_OPEN_READ,
GNUNET_DISK_PERM_NONE);
if (dc->top_request->state == BRS_CHK_SET)
{
if (NULL != dc->rfh)
{
/* first, try top-down */
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Trying top-down reconstruction for `%s'\n", dc->filename);
try_top_down_reconstruction (dc, dc->top_request);
switch (dc->top_request->state)
{
case BRS_CHK_SET:
break; /* normal */
case BRS_DOWNLOAD_DOWN:
break; /* normal, some blocks already down */
case BRS_DOWNLOAD_UP:
/* already done entirely, party! */
if (NULL != dc->rfh)
{
/* avoid hanging on to file handle longer than
* necessary */
GNUNET_DISK_file_close (dc->rfh);
dc->rfh = NULL;
}
return;
case BRS_ERROR:
GNUNET_asprintf (&dc->emsg, _("Invalid URI"));
GNUNET_FS_download_sync_ (dc);
pi.status = GNUNET_FS_STATUS_DOWNLOAD_ERROR;
pi.value.download.specifics.error.message = dc->emsg;
GNUNET_FS_download_make_status_ (&pi, dc);
return;
default:
GNUNET_assert (0);
break;
}
}
}
/* attempt reconstruction from meta data */
if ((GNUNET_FS_uri_chk_get_file_size (dc->uri) <= MAX_INLINE_SIZE) &&
(NULL != dc->meta))
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Trying to find embedded meta data for download of size %llu with %u bytes MD\n",
(unsigned long long) GNUNET_FS_uri_chk_get_file_size (dc->uri),
(unsigned int)
GNUNET_CONTAINER_meta_data_get_serialized_size (dc->meta));
GNUNET_CONTAINER_meta_data_iterate (dc->meta, &match_full_data, dc);
if (BRS_DOWNLOAD_UP == dc->top_request->state)
{
if (NULL != dc->rfh)
{
/* avoid hanging on to file handle longer than
* necessary */
GNUNET_DISK_file_close (dc->rfh);
dc->rfh = NULL;
}
return; /* finished, status update was already done for us */
}
}
if (NULL != dc->rfh)
{
/* finally, actually run bottom-up */
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Trying bottom-up reconstruction of file `%s'\n", dc->filename);
dc->te =
GNUNET_FS_tree_encoder_create (dc->h,
GNUNET_FS_uri_chk_get_file_size (dc->uri),
dc, &fh_reader,
&reconstruct_cb, NULL,
&reconstruct_cont);
dc->task = GNUNET_SCHEDULER_add_now (&get_next_block, dc);
}
else
{
/* simple, top-level download */
dc->issue_requests = GNUNET_YES;
schedule_block_download (dc, dc->top_request);
}
if (BRS_DOWNLOAD_UP == dc->top_request->state)
check_completed (dc);
}
/**
* Create SUSPEND event for the given download operation
* and then clean up our state (without stop signal).
*
* @param cls the 'struct GNUNET_FS_DownloadContext' to signal for
*/
void
GNUNET_FS_download_signal_suspend_ (void *cls)
{
struct GNUNET_FS_DownloadContext *dc = cls;
struct GNUNET_FS_ProgressInfo pi;
if (NULL != dc->top)
GNUNET_FS_end_top (dc->h, dc->top);
while (NULL != dc->child_head)
GNUNET_FS_download_signal_suspend_ (dc->child_head);
if (NULL != dc->search)
{
dc->search->download = NULL;
dc->search = NULL;
}
if (NULL != dc->job_queue)
{
GNUNET_FS_dequeue_ (dc->job_queue);
dc->job_queue = NULL;
}
if (NULL != dc->parent)
GNUNET_CONTAINER_DLL_remove (dc->parent->child_head, dc->parent->child_tail,
dc);
if (GNUNET_SCHEDULER_NO_TASK != dc->task)
{
GNUNET_SCHEDULER_cancel (dc->task);
dc->task = GNUNET_SCHEDULER_NO_TASK;
}
pi.status = GNUNET_FS_STATUS_DOWNLOAD_SUSPEND;
GNUNET_FS_download_make_status_ (&pi, dc);
if (NULL != dc->te)
{
GNUNET_FS_tree_encoder_finish (dc->te, NULL);
dc->te = NULL;
}
if (NULL != dc->rfh)
{
GNUNET_DISK_file_close (dc->rfh);
dc->rfh = NULL;
}
GNUNET_FS_free_download_request_ (dc->top_request);
if (NULL != dc->active)
{
GNUNET_CONTAINER_multihashmap_destroy (dc->active);
dc->active = NULL;
}
GNUNET_free_non_null (dc->filename);
GNUNET_CONTAINER_meta_data_destroy (dc->meta);
GNUNET_FS_uri_destroy (dc->uri);
GNUNET_free_non_null (dc->temp_filename);
GNUNET_free_non_null (dc->serialization);
GNUNET_assert (NULL == dc->job_queue);
GNUNET_free (dc);
}
/**
* Helper function to setup the download context.
*
* @param h handle to the file sharing subsystem
* @param uri the URI of the file (determines what to download); CHK or LOC URI
* @param meta known metadata for the file (can be NULL)
* @param filename where to store the file, maybe NULL (then no file is
* created on disk and data must be grabbed from the callbacks)
* @param tempname where to store temporary file data, not used if filename is non-NULL;
* can be NULL (in which case we will pick a name if needed); the temporary file
* may already exist, in which case we will try to use the data that is there and
* if it is not what is desired, will overwrite it
* @param offset at what offset should we start the download (typically 0)
* @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
* @return context that can be used to control this download
*/
struct GNUNET_FS_DownloadContext *
create_download_context (struct GNUNET_FS_Handle *h,
const struct GNUNET_FS_Uri *uri,
const struct GNUNET_CONTAINER_MetaData *meta,
const char *filename, const char *tempname,
uint64_t offset, uint64_t length, uint32_t anonymity,
enum GNUNET_FS_DownloadOptions options, void *cctx)
{
struct GNUNET_FS_DownloadContext *dc;
GNUNET_assert (GNUNET_FS_uri_test_chk (uri) || GNUNET_FS_uri_test_loc (uri));
if ((offset + length < offset) ||
(offset + length > GNUNET_FS_uri_chk_get_file_size (uri)))
{
GNUNET_break (0);
return NULL;
}
dc = GNUNET_new (struct GNUNET_FS_DownloadContext);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Starting download %p, %u bytes at offset %llu\n",
dc,
(unsigned long long) length,
(unsigned long long) offset);
dc->h = h;
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);
if (GNUNET_YES == GNUNET_DISK_file_test (filename))
GNUNET_break (GNUNET_OK == GNUNET_DISK_file_size (filename, &dc->old_file_size, GNUNET_YES, GNUNET_YES));
}
if (GNUNET_FS_uri_test_loc (dc->uri))
GNUNET_assert (GNUNET_OK ==
GNUNET_FS_uri_loc_get_peer_identity (dc->uri, &dc->target));
dc->offset = offset;
dc->length = length;
dc->anonymity = anonymity;
dc->options = options;
dc->active =
GNUNET_CONTAINER_multihashmap_create (1 + 2 * (length / DBLOCK_SIZE), GNUNET_NO);
dc->treedepth =
GNUNET_FS_compute_depth (GNUNET_FS_uri_chk_get_file_size (dc->uri));
if ((NULL == filename) && (is_recursive_download (dc)))
{
if (NULL != tempname)
dc->temp_filename = GNUNET_strdup (tempname);
else
dc->temp_filename = GNUNET_DISK_mktemp ("gnunet-directory-download-tmp");
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Starting download `%s' of %llu bytes with tree depth %u\n",
filename,
(unsigned long long) length,
dc->treedepth);
dc->task = GNUNET_SCHEDULER_add_now (&GNUNET_FS_download_start_task_, dc);
return dc;
}
/**
* Download parts of a file. Note that this will store
* the blocks at the respective offset in the given file. Also, the
* download is still using the blocking of the underlying FS
* encoding. As a result, the download may *write* outside of the
* given boundaries (if offset and length do not match the 32k FS
* block boundaries).
*
* This function should be used to focus a download towards a
* particular portion of the file (optimization), not to strictly
* limit the download to exactly those bytes.
*
* @param h handle to the file sharing subsystem
* @param uri the URI of the file (determines what to download); CHK or LOC URI
* @param meta known metadata for the file (can be NULL)
* @param filename where to store the file, maybe NULL (then no file is
* created on disk and data must be grabbed from the callbacks)
* @param tempname where to store temporary file data, not used if filename is non-NULL;
* can be NULL (in which case we will pick a name if needed); the temporary file
* may already exist, in which case we will try to use the data that is there and
* if it is not what is desired, will overwrite it
* @param offset at what offset should we start the download (typically 0)
* @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
*/
struct GNUNET_FS_DownloadContext *
GNUNET_FS_download_start (struct GNUNET_FS_Handle *h,
const struct GNUNET_FS_Uri *uri,
const struct GNUNET_CONTAINER_MetaData *meta,
const char *filename, const char *tempname,
uint64_t offset, uint64_t length, uint32_t anonymity,
enum GNUNET_FS_DownloadOptions options, void *cctx,
struct GNUNET_FS_DownloadContext *parent)
{
struct GNUNET_FS_DownloadContext *dc;
dc = create_download_context (h, uri, meta, filename, tempname,
offset, length, anonymity, options, cctx);
if (NULL == dc)
return NULL;
dc->parent = parent;
if (NULL != parent)
GNUNET_CONTAINER_DLL_insert (parent->child_head, parent->child_tail, dc);
else if (0 == (GNUNET_FS_DOWNLOAD_IS_PROBE & options) )
dc->top =
GNUNET_FS_make_top (dc->h, &GNUNET_FS_download_signal_suspend_, dc);
return dc;
}
/**
* Download parts of a file based on a search result. The download
* will be associated with the search result (and the association
* will be preserved when serializing/deserializing the state).
* If the search is stopped, the download will not be aborted but
* be 'promoted' to a stand-alone download.
*
* As with the other download function, this will store
* the blocks at the respective offset in the given file. Also, the
* download is still using the blocking of the underlying FS
* encoding. As a result, the download may *write* outside of the
* given boundaries (if offset and length do not match the 32k FS
* block boundaries).
*
* The given range can be used to focus a download towards a
* particular portion of the file (optimization), not to strictly
* limit the download to exactly those bytes.
*
* @param h handle to the file sharing subsystem
* @param sr the search result to use for the download (determines uri and
* meta data and associations)
* @param filename where to store the file, maybe NULL (then no file is
* created on disk and data must be grabbed from the callbacks)
* @param tempname where to store temporary file data, not used if filename is non-NULL;
* can be NULL (in which case we will pick a name if needed); the temporary file
* may already exist, in which case we will try to use the data that is there and
* if it is not what is desired, will overwrite it
* @param offset at what offset should we start the download (typically 0)
* @param length how many bytes should be downloaded starting at offset
* @param anonymity anonymity level to use for the download
* @param options various download options
* @param cctx initial value for the client context for this download
* @return context that can be used to control this download
*/
struct GNUNET_FS_DownloadContext *
GNUNET_FS_download_start_from_search (struct GNUNET_FS_Handle *h,
struct GNUNET_FS_SearchResult *sr,
const char *filename,
const char *tempname, uint64_t offset,
uint64_t length, uint32_t anonymity,
enum GNUNET_FS_DownloadOptions options,
void *cctx)
{
struct GNUNET_FS_DownloadContext *dc;
if ((NULL == sr) || (NULL != sr->download))
{
GNUNET_break (0);
return NULL;
}
dc = create_download_context (h, sr->uri, sr->meta, filename, tempname,
offset, length, anonymity, options, cctx);
if (NULL == dc)
return NULL;
dc->search = sr;
sr->download = dc;
if (NULL != sr->probe_ctx)
{
GNUNET_FS_download_stop (sr->probe_ctx, GNUNET_YES);
sr->probe_ctx = NULL;
}
if (GNUNET_SCHEDULER_NO_TASK != sr->probe_ping_task)
{
GNUNET_SCHEDULER_cancel (sr->probe_ping_task);
sr->probe_ping_task = GNUNET_SCHEDULER_NO_TASK;
}
return dc;
}
/**
* Start the downloading process (by entering the queue).
*
* @param dc our download context
*/
void
GNUNET_FS_download_start_downloading_ (struct GNUNET_FS_DownloadContext *dc)
{
if (dc->completed == dc->length)
return;
GNUNET_assert (NULL == dc->job_queue);
GNUNET_assert (NULL != dc->active);
dc->job_queue =
GNUNET_FS_queue_ (dc->h, &activate_fs_download, &deactivate_fs_download,
dc, (dc->length + DBLOCK_SIZE - 1) / DBLOCK_SIZE,
(0 == (dc->options & GNUNET_FS_DOWNLOAD_IS_PROBE))
? GNUNET_FS_QUEUE_PRIORITY_NORMAL
: GNUNET_FS_QUEUE_PRIORITY_PROBE);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Download %p put into queue as job %p\n",
dc,
dc->job_queue);
}
/**
* Stop a download (aborts if download is incomplete).
*
* @param dc handle for the download
* @param do_delete delete files of incomplete downloads
*/
void
GNUNET_FS_download_stop (struct GNUNET_FS_DownloadContext *dc, int do_delete)
{
struct GNUNET_FS_ProgressInfo pi;
int have_children;
int search_was_null;
if (NULL != dc->top)
GNUNET_FS_end_top (dc->h, dc->top);
if (GNUNET_SCHEDULER_NO_TASK != dc->task)
{
GNUNET_SCHEDULER_cancel (dc->task);
dc->task = GNUNET_SCHEDULER_NO_TASK;
}
search_was_null = (NULL == dc->search);
if (NULL != dc->search)
{
dc->search->download = NULL;
GNUNET_FS_search_result_sync_ (dc->search);
dc->search = NULL;
}
if (NULL != dc->job_queue)
{
GNUNET_FS_dequeue_ (dc->job_queue);
dc->job_queue = NULL;
}
if (NULL != dc->te)
{
GNUNET_FS_tree_encoder_finish (dc->te, NULL);
dc->te = NULL;
}
have_children = (NULL != dc->child_head) ? GNUNET_YES : GNUNET_NO;
while (NULL != dc->child_head)
GNUNET_FS_download_stop (dc->child_head, do_delete);
if (NULL != dc->parent)
GNUNET_CONTAINER_DLL_remove (dc->parent->child_head, dc->parent->child_tail,
dc);
if (NULL != dc->serialization)
GNUNET_FS_remove_sync_file_ (dc->h,
((NULL != dc->parent) ||
(! search_was_null)) ? GNUNET_FS_SYNC_PATH_CHILD_DOWNLOAD :
GNUNET_FS_SYNC_PATH_MASTER_DOWNLOAD,
dc->serialization);
if ((GNUNET_YES == have_children) && (NULL == dc->parent))
GNUNET_FS_remove_sync_dir_ (dc->h,
(! search_was_null) ? GNUNET_FS_SYNC_PATH_CHILD_DOWNLOAD :
GNUNET_FS_SYNC_PATH_MASTER_DOWNLOAD,
dc->serialization);
pi.status = GNUNET_FS_STATUS_DOWNLOAD_STOPPED;
GNUNET_FS_download_make_status_ (&pi, dc);
GNUNET_FS_free_download_request_ (dc->top_request);
dc->top_request = NULL;
if (NULL != dc->active)
{
GNUNET_CONTAINER_multihashmap_destroy (dc->active);
dc->active = NULL;
}
if (NULL != dc->filename)
{
if ((dc->completed != dc->length) && (GNUNET_YES == do_delete))
{
if ( (0 != UNLINK (dc->filename)) &&
(ENOENT != errno) )
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "unlink",
dc->filename);
}
GNUNET_free (dc->filename);
}
GNUNET_CONTAINER_meta_data_destroy (dc->meta);
GNUNET_FS_uri_destroy (dc->uri);
if (NULL != dc->temp_filename)
{
if (0 != UNLINK (dc->temp_filename))
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "unlink",
dc->temp_filename);
GNUNET_free (dc->temp_filename);
}
GNUNET_free_non_null (dc->serialization);
GNUNET_assert (NULL == dc->job_queue);
GNUNET_free (dc);
}
/* end of fs_download.c */