transmission/libtransmission/webseed.c

588 lines
18 KiB
C

/*
* This file Copyright (C) Mnemosyne LLC
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <string.h> /* strlen() */
#include <event2/buffer.h>
#include <event2/event.h>
#include "transmission.h"
#include "bandwidth.h"
#include "cache.h"
#include "inout.h" /* tr_ioFindFileLocation() */
#include "list.h"
#include "peer-mgr.h"
#include "torrent.h"
#include "trevent.h" /* tr_runInEventThread() */
#include "utils.h"
#include "web.h"
#include "webseed.h"
struct tr_webseed_task
{
struct evbuffer * content;
struct tr_webseed * webseed;
tr_block_index_t block;
tr_piece_index_t piece_index;
uint32_t piece_offset;
uint32_t length;
tr_block_index_t blocks_done;
uint32_t block_size;
struct tr_web_task * web_task;
long response_code;
};
struct tr_webseed
{
tr_peer parent;
tr_bandwidth bandwidth;
tr_session * session;
tr_peer_callback * callback;
void * callback_data;
tr_list * tasks;
struct event * timer;
char * base_url;
size_t base_url_len;
int torrent_id;
bool is_stopping;
int consecutive_failures;
int retry_tickcount;
int retry_challenge;
int idle_connections;
int active_transfers;
char ** file_urls;
};
enum
{
TR_IDLE_TIMER_MSEC = 2000,
FAILURE_RETRY_INTERVAL = 150,
MAX_CONSECUTIVE_FAILURES = 5,
MAX_WEBSEED_CONNECTIONS = 4
};
static void
webseed_free( struct tr_webseed * w )
{
tr_torrent * tor = tr_torrentFindFromId( w->session, w->torrent_id );
const tr_info * inf = tr_torrentInfo( tor );
tr_file_index_t i;
for( i=0; i<inf->fileCount; ++i )
tr_free( w->file_urls[i] );
tr_free( w->file_urls );
/* webseed destruct */
event_free( w->timer );
tr_bandwidthDestruct( &w->bandwidth );
tr_free( w->base_url );
/* parent class destruct */
tr_peerDestruct( tor, &w->parent );
tr_free( w );
}
/***
****
***/
static void
publish( tr_webseed * w, tr_peer_event * e )
{
if( w->callback != NULL )
w->callback( &w->parent, e, w->callback_data );
}
static void
fire_client_got_rejs( tr_torrent * tor, tr_webseed * w,
tr_block_index_t block, tr_block_index_t count )
{
tr_block_index_t i;
tr_peer_event e = TR_PEER_EVENT_INIT;
e.eventType = TR_PEER_CLIENT_GOT_REJ;
tr_torrentGetBlockLocation( tor, block, &e.pieceIndex, &e.offset, &e.length );
for( i = 1; i <= count; i++ ) {
if( i == count )
e.length = tr_torBlockCountBytes( tor, block + count - 1 );
publish( w, &e );
e.offset += e.length;
}
}
static void
fire_client_got_blocks( tr_torrent * tor, tr_webseed * w,
tr_block_index_t block, tr_block_index_t count )
{
tr_block_index_t i;
tr_peer_event e = TR_PEER_EVENT_INIT;
e.eventType = TR_PEER_CLIENT_GOT_BLOCK;
tr_torrentGetBlockLocation( tor, block, &e.pieceIndex, &e.offset, &e.length );
for( i = 1; i <= count; i++ ) {
if( i == count )
e.length = tr_torBlockCountBytes( tor, block + count - 1 );
publish( w, &e );
e.offset += e.length;
}
}
static void
fire_client_got_data( tr_webseed * w, uint32_t length )
{
tr_peer_event e = TR_PEER_EVENT_INIT;
e.eventType = TR_PEER_CLIENT_GOT_DATA;
e.length = length;
e.wasPieceData = true;
publish( w, &e );
}
/***
****
***/
struct write_block_data
{
struct tr_webseed * webseed;
struct evbuffer * content;
tr_piece_index_t piece_index;
tr_block_index_t block_index;
tr_block_index_t count;
uint32_t block_offset;
};
static void
write_block_func( void * vdata )
{
struct write_block_data * data = vdata;
struct tr_webseed * w = data->webseed;
struct evbuffer * buf = data->content;
struct tr_torrent * tor;
tor = tr_torrentFindFromId( w->session, w->torrent_id );
if( tor )
{
const uint32_t block_size = tor->blockSize;
uint32_t len = evbuffer_get_length( buf );
const uint32_t offset_end = data->block_offset + len;
tr_cache * cache = w->session->cache;
const tr_piece_index_t piece = data->piece_index;
while( len > 0 )
{
const uint32_t bytes_this_pass = MIN( len, block_size );
tr_cacheWriteBlock( cache, tor, piece, offset_end - len, bytes_this_pass, buf );
len -= bytes_this_pass;
}
fire_client_got_blocks( tor, w, data->block_index, data->count );
}
evbuffer_free( buf );
tr_free( data );
}
/***
****
***/
struct connection_succeeded_data
{
struct tr_webseed * webseed;
char * real_url;
tr_piece_index_t piece_index;
uint32_t piece_offset;
};
static void
connection_succeeded( void * vdata )
{
tr_torrent * tor;
struct connection_succeeded_data * data = vdata;
struct tr_webseed * w = data->webseed;
if( ++w->active_transfers >= w->retry_challenge && w->retry_challenge )
/* the server seems to be accepting more connections now */
w->consecutive_failures = w->retry_tickcount = w->retry_challenge = 0;
if( data->real_url &&
(tor = tr_torrentFindFromId( w->session, w->torrent_id )))
{
uint64_t file_offset;
tr_file_index_t file_index;
tr_ioFindFileLocation( tor, data->piece_index, data->piece_offset,
&file_index, &file_offset );
tr_free( w->file_urls[file_index] );
w->file_urls[file_index] = data->real_url;
}
}
/***
****
***/
static void
on_content_changed( struct evbuffer * buf,
const struct evbuffer_cb_info * info,
void * vtask )
{
uint32_t len;
const size_t n_added = info->n_added;
struct tr_webseed_task * task = vtask;
struct tr_webseed * w = task->webseed;
if( n_added <= 0 )
return;
if( !w->is_stopping )
{
tr_bandwidthUsed( &w->bandwidth, TR_DOWN, n_added, true, tr_time_msec( ) );
fire_client_got_data( w, n_added );
}
len = evbuffer_get_length( buf );
if( !task->response_code )
{
tr_webGetTaskInfo( task->web_task, TR_WEB_GET_CODE, &task->response_code );
if( task->response_code == 206 )
{
const char * url;
struct connection_succeeded_data * data;
url = NULL;
tr_webGetTaskInfo( task->web_task, TR_WEB_GET_REAL_URL, &url );
data = tr_new( struct connection_succeeded_data, 1 );
data->webseed = w;
data->real_url = tr_strdup( url );
data->piece_index = task->piece_index;
data->piece_offset = task->piece_offset
+ (task->blocks_done * task->block_size)
+ (len - 1);
/* processing this uses a tr_torrent pointer,
so push the work to the libevent thread... */
tr_runInEventThread( w->session, connection_succeeded, data );
}
}
if( ( task->response_code == 206 ) && ( len >= task->block_size ) )
{
/* once we've got at least one full block, save it */
struct write_block_data * data;
const uint32_t block_size = task->block_size;
const tr_block_index_t completed = len / block_size;
data = tr_new( struct write_block_data, 1 );
data->webseed = task->webseed;
data->piece_index = task->piece_index;
data->block_index = task->block + task->blocks_done;
data->count = completed;
data->block_offset = task->piece_offset + task->blocks_done * block_size;
data->content = evbuffer_new( );
/* we don't use locking on this evbuffer so we must copy out the data
that will be needed when writing the block in a different thread */
evbuffer_remove_buffer( task->content, data->content,
block_size * completed );
tr_runInEventThread( w->session, write_block_func, data );
task->blocks_done += completed;
}
}
static void task_request_next_chunk( struct tr_webseed_task * task );
static bool
webseed_has_tasks( const tr_webseed * w )
{
return w->tasks != NULL;
}
static void
on_idle( tr_webseed * w )
{
tr_torrent * tor = tr_torrentFindFromId( w->session, w->torrent_id );
int want, running_tasks = tr_list_size( w->tasks );
if( w->consecutive_failures >= MAX_CONSECUTIVE_FAILURES ) {
want = w->idle_connections;
if( w->retry_tickcount >= FAILURE_RETRY_INTERVAL ) {
/* some time has passed since our connection attempts failed. try again */
++want;
/* if this challenge is fulfilled we will reset consecutive_failures */
w->retry_challenge = running_tasks + want;
}
}
else {
want = MAX_WEBSEED_CONNECTIONS - running_tasks;
w->retry_challenge = running_tasks + w->idle_connections + 1;
}
if( w->is_stopping && !webseed_has_tasks( w ) )
{
webseed_free( w );
}
else if( !w->is_stopping && tor
&& tor->isRunning
&& !tr_torrentIsSeed( tor )
&& want )
{
int i;
int got = 0;
tr_block_index_t * blocks = NULL;
blocks = tr_new( tr_block_index_t, want*2 );
tr_peerMgrGetNextRequests( tor, &w->parent, want, blocks, &got, true );
w->idle_connections -= MIN( w->idle_connections, got );
if( w->retry_tickcount >= FAILURE_RETRY_INTERVAL && got == want )
w->retry_tickcount = 0;
for( i=0; i<got; ++i )
{
const tr_block_index_t b = blocks[i*2];
const tr_block_index_t be = blocks[i*2+1];
struct tr_webseed_task * task = tr_new( struct tr_webseed_task, 1 );
task->webseed = w;
task->block = b;
task->piece_index = tr_torBlockPiece( tor, b );
task->piece_offset = ( tor->blockSize * b )
- ( tor->info.pieceSize * task->piece_index );
task->length = (be - b) * tor->blockSize + tr_torBlockCountBytes( tor, be );
task->blocks_done = 0;
task->response_code = 0;
task->block_size = tor->blockSize;
task->content = evbuffer_new( );
evbuffer_add_cb( task->content, on_content_changed, task );
tr_list_append( &w->tasks, task );
task_request_next_chunk( task );
}
tr_free( blocks );
}
}
static void
web_response_func( tr_session * session,
bool did_connect UNUSED,
bool did_timeout UNUSED,
long response_code,
const void * response UNUSED,
size_t response_byte_count UNUSED,
void * vtask )
{
struct tr_webseed_task * t = vtask;
tr_webseed * w = t->webseed;
tr_torrent * tor = tr_torrentFindFromId( session, w->torrent_id );
const int success = ( response_code == 206 );
if( tor )
{
/* active_transfers was only increased if the connection was successful */
if( t->response_code == 206 )
--w->active_transfers;
if( !success )
{
const tr_block_index_t blocks_remain = (t->length + tor->blockSize - 1)
/ tor->blockSize - t->blocks_done;
if( blocks_remain )
fire_client_got_rejs( tor, w, t->block + t->blocks_done, blocks_remain );
if( t->blocks_done )
++w->idle_connections;
else if( ++w->consecutive_failures >= MAX_CONSECUTIVE_FAILURES && !w->retry_tickcount )
/* now wait a while until retrying to establish a connection */
++w->retry_tickcount;
tr_list_remove_data( &w->tasks, t );
evbuffer_free( t->content );
tr_free( t );
}
else
{
const uint32_t bytes_done = t->blocks_done * tor->blockSize;
const uint32_t buf_len = evbuffer_get_length( t->content );
if( bytes_done + buf_len < t->length )
{
/* request finished successfully but there's still data missing. that
means we've reached the end of a file and need to request the next one */
t->response_code = 0;
task_request_next_chunk( t );
}
else
{
if( buf_len ) {
/* on_content_changed() will not write a block if it is smaller than
the torrent's block size, i.e. the torrent's very last block */
tr_cacheWriteBlock( session->cache, tor,
t->piece_index, t->piece_offset + bytes_done,
buf_len, t->content );
fire_client_got_blocks( tor, t->webseed,
t->block + t->blocks_done, 1 );
}
++w->idle_connections;
tr_list_remove_data( &w->tasks, t );
evbuffer_free( t->content );
tr_free( t );
on_idle( w );
}
}
}
}
static struct evbuffer *
make_url( tr_webseed * w, const tr_file * file )
{
struct evbuffer * buf = evbuffer_new( );
evbuffer_add( buf, w->base_url, w->base_url_len );
/* if url ends with a '/', add the torrent name */
if( w->base_url[w->base_url_len - 1] == '/' && file->name )
tr_http_escape( buf, file->name, strlen(file->name), false );
return buf;
}
static void
task_request_next_chunk( struct tr_webseed_task * t )
{
tr_webseed * w = t->webseed;
tr_torrent * tor = tr_torrentFindFromId( w->session, w->torrent_id );
if( tor != NULL )
{
char range[64];
char ** urls = t->webseed->file_urls;
const tr_info * inf = tr_torrentInfo( tor );
const uint64_t remain = t->length - t->blocks_done * tor->blockSize
- evbuffer_get_length( t->content );
const uint64_t total_offset = tr_pieceOffset( tor, t->piece_index,
t->piece_offset,
t->length - remain );
const tr_piece_index_t step_piece = total_offset / inf->pieceSize;
const uint64_t step_piece_offset
= total_offset - ( inf->pieceSize * step_piece );
tr_file_index_t file_index;
const tr_file * file;
uint64_t file_offset;
uint64_t this_pass;
tr_ioFindFileLocation( tor, step_piece, step_piece_offset,
&file_index, &file_offset );
file = &inf->files[file_index];
this_pass = MIN( remain, file->length - file_offset );
if( !urls[file_index] )
urls[file_index] = evbuffer_free_to_str( make_url( t->webseed, file ) );
tr_snprintf( range, sizeof range, "%"PRIu64"-%"PRIu64,
file_offset, file_offset + this_pass - 1 );
t->web_task = tr_webRunWithBuffer( w->session, urls[file_index],
range, NULL, web_response_func, t, t->content );
}
}
bool
tr_webseedGetSpeed_Bps( const tr_webseed * w,
uint64_t now,
unsigned int * setme_Bps )
{
const bool is_active = webseed_has_tasks( w );
*setme_Bps = is_active ? tr_bandwidthGetPieceSpeed_Bps( &w->bandwidth, now, TR_DOWN ) : 0;
return is_active;
}
bool
tr_webseedIsActive( const tr_webseed * w )
{
unsigned int Bps = 0;
return tr_webseedGetSpeed_Bps( w, tr_time_msec(), &Bps ) && ( Bps > 0 );
}
/***
****
***/
static void
webseed_timer_func( evutil_socket_t foo UNUSED, short bar UNUSED, void * vw )
{
tr_webseed * w = vw;
if( w->retry_tickcount )
++w->retry_tickcount;
on_idle( w );
tr_timerAddMsec( w->timer, TR_IDLE_TIMER_MSEC );
}
tr_webseed*
tr_webseedNew( struct tr_torrent * tor,
const char * url,
tr_peer_callback * callback,
void * callback_data )
{
tr_webseed * w = tr_new0( tr_webseed, 1 );
tr_peer * peer = &w->parent;
const tr_info * inf = tr_torrentInfo( tor );
/* construct parent class */
tr_peerConstruct( peer );
peer->peerIsChoked = true;
peer->clientIsInterested = !tr_torrentIsSeed( tor );
peer->client = tr_strdup( "webseed" );
tr_bitfieldSetHasAll( &peer->have );
tr_peerUpdateProgress( tor, peer );
w->torrent_id = tr_torrentId( tor );
w->session = tor->session;
w->base_url_len = strlen( url );
w->base_url = tr_strndup( url, w->base_url_len );
w->callback = callback;
w->callback_data = callback_data;
w->file_urls = tr_new0( char *, inf->fileCount );
//tr_rcConstruct( &w->download_rate );
tr_bandwidthConstruct( &w->bandwidth, tor->session, &tor->bandwidth );
w->timer = evtimer_new( w->session->event_base, webseed_timer_func, w );
tr_timerAddMsec( w->timer, TR_IDLE_TIMER_MSEC );
return w;
}
void
tr_webseedFree( tr_webseed * w )
{
if( w )
{
if( webseed_has_tasks( w ) )
w->is_stopping = true;
else
webseed_free( w );
}
}