transmission/libtransmission/announcer.c

1762 lines
52 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 <assert.h>
#include <limits.h> /* INT_MAX */
#include <stdio.h>
#include <stdlib.h> /* qsort () */
#include <string.h> /* strcmp (), memcpy () */
#include <event2/buffer.h>
#include <event2/event.h> /* evtimer */
#define __LIBTRANSMISSION_ANNOUNCER_MODULE___
#include "transmission.h"
#include "announcer.h"
#include "announcer-common.h"
#include "crypto.h" /* tr_cryptoRandInt (), tr_cryptoWeakRandInt () */
#include "peer-mgr.h" /* tr_peerMgrCompactToPex () */
#include "ptrarray.h"
#include "session.h"
#include "torrent.h"
#include "utils.h"
struct tr_tier;
static void tier_build_log_name (const struct tr_tier * tier,
char * buf, size_t buflen);
#define dbgmsg(tier, ...) \
if (tr_deepLoggingIsActive ()) do { \
char name[128]; \
tier_build_log_name (tier, name, sizeof (name)); \
tr_deepLog (__FILE__, __LINE__, name, __VA_ARGS__); \
} while (0)
enum
{
/* unless the tracker says otherwise, rescrape this frequently */
DEFAULT_SCRAPE_INTERVAL_SEC = (60 * 30),
/* unless the tracker says otherwise, this is the announce interval */
DEFAULT_ANNOUNCE_INTERVAL_SEC = (60 * 10),
/* unless the tracker says otherwise, this is the announce min_interval */
DEFAULT_ANNOUNCE_MIN_INTERVAL_SEC = (60 * 2),
/* how many web tasks we allow at one time */
MAX_CONCURRENT_TASKS = 48,
/* the value of the 'numwant' argument passed in tracker requests. */
NUMWANT = 80,
UPKEEP_INTERVAL_SECS = 1,
/* this is how often to call the UDP tracker upkeep */
TAU_UPKEEP_INTERVAL_SECS = 5
};
/***
****
***/
const char*
tr_announce_event_get_string (tr_announce_event e)
{
switch (e)
{
case TR_ANNOUNCE_EVENT_COMPLETED: return "completed";
case TR_ANNOUNCE_EVENT_STARTED: return "started";
case TR_ANNOUNCE_EVENT_STOPPED: return "stopped";
default: return "";
}
}
/***
****
***/
static int
compareTransfer (uint64_t a_uploaded, uint64_t a_downloaded,
uint64_t b_uploaded, uint64_t b_downloaded)
{
/* higher upload count goes first */
if (a_uploaded != b_uploaded)
return a_uploaded > b_uploaded ? -1 : 1;
/* then higher download count goes first */
if (a_downloaded != b_downloaded)
return a_downloaded > b_downloaded ? -1 : 1;
return 0;
}
/**
* Comparison function for tr_announce_requests.
*
* The primary key (amount of data transferred) is used to prioritize
* tracker announcements of active torrents. The remaining keys are
* used to satisfy the uniqueness requirement of a sorted tr_ptrArray.
*/
static int
compareStops (const void * va, const void * vb)
{
int i;
const tr_announce_request * a = va;
const tr_announce_request * b = vb;
/* primary key: volume of data transferred. */
if ((i = compareTransfer (a->up, a->down, b->up, b->down)))
return i;
/* secondary key: the torrent's info_hash */
if ((i = memcmp (a->info_hash, b->info_hash, SHA_DIGEST_LENGTH)))
return i;
/* tertiary key: the tracker's announec url */
return tr_strcmp0 (a->url, b->url);
}
/***
****
***/
/**
* "global" (per-tr_session) fields
*/
typedef struct tr_announcer
{
tr_ptrArray stops; /* tr_announce_request */
tr_session * session;
struct event * upkeepTimer;
int slotsAvailable;
int key;
time_t tauUpkeepAt;
}
tr_announcer;
bool
tr_announcerHasBacklog (const struct tr_announcer * announcer)
{
return announcer->slotsAvailable < 1;
}
static void
onUpkeepTimer (int foo UNUSED, short bar UNUSED, void * vannouncer);
void
tr_announcerInit (tr_session * session)
{
tr_announcer * a;
assert (tr_isSession (session));
a = tr_new0 (tr_announcer, 1);
a->stops = TR_PTR_ARRAY_INIT;
a->key = tr_cryptoRandInt (INT_MAX);
a->session = session;
a->slotsAvailable = MAX_CONCURRENT_TASKS;
a->upkeepTimer = evtimer_new (session->event_base, onUpkeepTimer, a);
tr_timerAdd (a->upkeepTimer, UPKEEP_INTERVAL_SECS, 0);
session->announcer = a;
}
static void flushCloseMessages (tr_announcer * announcer);
void
tr_announcerClose (tr_session * session)
{
tr_announcer * announcer = session->announcer;
flushCloseMessages (announcer);
tr_tracker_udp_start_shutdown (session);
event_free (announcer->upkeepTimer);
announcer->upkeepTimer = NULL;
tr_ptrArrayDestruct (&announcer->stops, NULL);
session->announcer = NULL;
tr_free (announcer);
}
/***
****
***/
/* a row in tr_tier's list of trackers */
typedef struct
{
char * key;
char * announce;
char * scrape;
char * tracker_id_str;
int seederCount;
int leecherCount;
int downloadCount;
int downloaderCount;
int consecutiveFailures;
uint32_t id;
}
tr_tracker;
/* format: host+':'+ port */
static char *
getKey (const char * url)
{
char * ret;
char * scheme = NULL;
char * host = NULL;
int port = 0;
tr_urlParse (url, -1, &scheme, &host, &port, NULL);
ret = tr_strdup_printf ("%s://%s:%d", (scheme?scheme:"invalid"), (host?host:"invalid"), port);
tr_free (host);
tr_free (scheme);
return ret;
}
static void
trackerConstruct (tr_tracker * tracker, const tr_tracker_info * inf)
{
memset (tracker, 0, sizeof (tr_tracker));
tracker->key = getKey (inf->announce);
tracker->announce = tr_strdup (inf->announce);
tracker->scrape = tr_strdup (inf->scrape);
tracker->id = inf->id;
tracker->seederCount = -1;
tracker->leecherCount = -1;
tracker->downloadCount = -1;
}
static void
trackerDestruct (tr_tracker * tracker)
{
tr_free (tracker->tracker_id_str);
tr_free (tracker->scrape);
tr_free (tracker->announce);
tr_free (tracker->key);
}
/***
****
***/
struct tr_torrent_tiers;
/** @brief A group of trackers in a single tier, as per the multitracker spec */
typedef struct tr_tier
{
/* number of up/down/corrupt bytes since the last time we sent an
* "event=stopped" message that was acknowledged by the tracker */
uint64_t byteCounts[3];
tr_tracker * trackers;
int tracker_count;
tr_tracker * currentTracker;
int currentTrackerIndex;
tr_torrent * tor;
time_t scrapeAt;
time_t lastScrapeStartTime;
time_t lastScrapeTime;
bool lastScrapeSucceeded;
bool lastScrapeTimedOut;
time_t announceAt;
time_t manualAnnounceAllowedAt;
time_t lastAnnounceStartTime;
time_t lastAnnounceTime;
bool lastAnnounceSucceeded;
bool lastAnnounceTimedOut;
tr_announce_event * announce_events;
int announce_event_count;
int announce_event_alloc;
/* unique lookup key */
int key;
int scrapeIntervalSec;
int announceIntervalSec;
int announceMinIntervalSec;
int lastAnnouncePeerCount;
bool isRunning;
bool isAnnouncing;
bool isScraping;
bool wasCopied;
char lastAnnounceStr[128];
char lastScrapeStr[128];
}
tr_tier;
static time_t
get_next_scrape_time (const tr_session * session, const tr_tier * tier, int interval)
{
time_t ret;
const time_t now = tr_time ();
/* Maybe don't scrape paused torrents */
if (!tier->isRunning && !session->scrapePausedTorrents)
ret = 0;
/* Add the interval, and then increment to the nearest 10th second.
* The latter step is to increase the odds of several torrents coming
* due at the same time to improve multiscrape. */
else {
ret = now + interval;
while (ret % 10)
++ret;
}
return ret;
}
static void
tierConstruct (tr_tier * tier, tr_torrent * tor)
{
static int nextKey = 1;
memset (tier, 0, sizeof (tr_tier));
tier->key = nextKey++;
tier->currentTrackerIndex = -1;
tier->scrapeIntervalSec = DEFAULT_SCRAPE_INTERVAL_SEC;
tier->announceIntervalSec = DEFAULT_ANNOUNCE_INTERVAL_SEC;
tier->announceMinIntervalSec = DEFAULT_ANNOUNCE_MIN_INTERVAL_SEC;
tier->scrapeAt = get_next_scrape_time (tor->session, tier, tr_cryptoWeakRandInt (180));
tier->tor = tor;
}
static void
tierDestruct (tr_tier * tier)
{
tr_free (tier->announce_events);
}
static void
tier_build_log_name (const tr_tier * tier, char * buf, size_t buflen)
{
tr_snprintf (buf, buflen, "[%s---%s]",
(tier && tier->tor) ? tr_torrentName (tier->tor) : "?",
(tier && tier->currentTracker) ? tier->currentTracker->key : "?");
}
static void
tierIncrementTracker (tr_tier * tier)
{
/* move our index to the next tracker in the tier */
const int i = (tier->currentTracker == NULL)
? 0
: (tier->currentTrackerIndex + 1) % tier->tracker_count;
tier->currentTrackerIndex = i;
tier->currentTracker = &tier->trackers[i];
/* reset some of the tier's fields */
tier->scrapeIntervalSec = DEFAULT_SCRAPE_INTERVAL_SEC;
tier->announceIntervalSec = DEFAULT_ANNOUNCE_INTERVAL_SEC;
tier->announceMinIntervalSec = DEFAULT_ANNOUNCE_MIN_INTERVAL_SEC;
tier->isAnnouncing = false;
tier->isScraping = false;
tier->lastAnnounceStartTime = 0;
tier->lastScrapeStartTime = 0;
}
/***
****
***/
/**
* @brief Opaque, per-torrent data structure for tracker announce information
*
* this opaque data structure can be found in tr_torrent.tiers
*/
typedef struct tr_torrent_tiers
{
tr_tier * tiers;
int tier_count;
tr_tracker * trackers;
int tracker_count;
tr_tracker_callback * callback;
void * callbackData;
}
tr_torrent_tiers;
static tr_torrent_tiers*
tiersNew (void)
{
return tr_new0 (tr_torrent_tiers, 1);
}
static void
tiersDestruct (tr_torrent_tiers * tt)
{
int i;
for (i=0; i<tt->tracker_count; ++i)
trackerDestruct (&tt->trackers[i]);
tr_free (tt->trackers);
for (i=0; i<tt->tier_count; ++i)
tierDestruct (&tt->tiers[i]);
tr_free (tt->tiers);
}
static void
tiersFree (tr_torrent_tiers * tt)
{
tiersDestruct (tt);
tr_free (tt);
}
static tr_tier*
getTier (tr_announcer * announcer, const uint8_t * info_hash, int tierId)
{
tr_tier * tier = NULL;
if (announcer != NULL)
{
tr_session * session = announcer->session;
tr_torrent * tor = tr_torrentFindFromHash (session, info_hash);
if (tor && tor->tiers)
{
int i;
tr_torrent_tiers * tt = tor->tiers;
for (i=0; !tier && i<tt->tier_count; ++i)
if (tt->tiers[i].key == tierId)
tier = &tt->tiers[i];
}
}
return tier;
}
/***
**** PUBLISH
***/
static const tr_tracker_event TRACKER_EVENT_INIT = { 0, 0, 0, 0, 0, 0 };
static void
publishMessage (tr_tier * tier, const char * msg, int type)
{
if (tier && tier->tor && tier->tor->tiers && tier->tor->tiers->callback)
{
tr_torrent_tiers * tiers = tier->tor->tiers;
tr_tracker_event event = TRACKER_EVENT_INIT;
event.messageType = type;
event.text = msg;
if (tier->currentTracker)
event.tracker = tier->currentTracker->announce;
tiers->callback (tier->tor, &event, tiers->callbackData);
}
}
static void
publishErrorClear (tr_tier * tier)
{
publishMessage (tier, NULL, TR_TRACKER_ERROR_CLEAR);
}
static void
publishWarning (tr_tier * tier, const char * msg)
{
publishMessage (tier, msg, TR_TRACKER_WARNING);
}
static void
publishError (tr_tier * tier, const char * msg)
{
publishMessage (tier, msg, TR_TRACKER_ERROR);
}
static int8_t
getSeedProbability (tr_tier * tier, int seeds, int leechers, int pex_count)
{
/* special case optimization:
ocelot omits seeds from peer lists sent to seeds on private trackers.
so check for that case... */
if ((leechers == pex_count) && tr_torrentIsPrivate (tier->tor)
&& tr_torrentIsSeed (tier->tor)
&& (seeds + leechers < NUMWANT))
return 0;
if (seeds>=0 && leechers>=0 && (seeds+leechers>0))
return (int8_t)((100.0*seeds)/ (seeds+leechers));
return -1; /* unknown */
}
static void
publishPeersPex (tr_tier * tier, int seeds, int leechers,
const tr_pex * pex, int n)
{
if (tier->tor->tiers->callback)
{
tr_tracker_event e = TRACKER_EVENT_INIT;
e.messageType = TR_TRACKER_PEERS;
e.seedProbability = getSeedProbability (tier, seeds, leechers, n);
e.pex = pex;
e.pexCount = n;
dbgmsg (tier, "got %d peers; seed prob %d", n, (int)e.seedProbability);
tier->tor->tiers->callback (tier->tor, &e, NULL);
}
}
/***
****
***/
struct ann_tracker_info
{
tr_tracker_info info;
char * scheme;
char * host;
char * path;
int port;
};
/* primary key: tier
* secondary key: udp comes before http */
static int
filter_trackers_compare_func (const void * va, const void * vb)
{
const struct ann_tracker_info * a = va;
const struct ann_tracker_info * b = vb;
if (a->info.tier != b->info.tier)
return a->info.tier - b->info.tier;
return -strcmp (a->scheme, b->scheme);
}
/**
* Massages the incoming list of trackers into something we can use.
*/
static tr_tracker_info *
filter_trackers (tr_tracker_info * input, int input_count, int * setme_count)
{
int i, in;
int j, jn;
int n = 0;
struct tr_tracker_info * ret;
struct ann_tracker_info * tmp = tr_new0 (struct ann_tracker_info, input_count);
/*for (i=0, in=input_count; i<in; ++i) fprintf (stderr, "IN: [%d][%s]\n", input[i].tier, input[i].announce);*/
/* build a list of valid trackers */
for (i=0, in=input_count; i<in; ++i) {
if (tr_urlIsValidTracker (input[i].announce)) {
int port;
char * scheme;
char * host;
char * path;
bool is_duplicate = false;
tr_urlParse (input[i].announce, -1, &scheme, &host, &port, &path);
/* weed out one common source of duplicates:
* "http://tracker/announce" +
* "http://tracker:80/announce"
*/
for (j=0, jn=n; !is_duplicate && j<jn; ++j)
is_duplicate = (tmp[j].port==port)
&& !strcmp (tmp[j].scheme,scheme)
&& !strcmp (tmp[j].host,host)
&& !strcmp (tmp[j].path,path);
if (is_duplicate) {
tr_free (path);
tr_free (host);
tr_free (scheme);
continue;
}
tmp[n].info = input[i];
tmp[n].scheme = scheme;
tmp[n].host = host;
tmp[n].port = port;
tmp[n].path = path;
n++;
}
}
/* if two announce URLs differ only by scheme, put them in the same tier.
* (note: this can leave gaps in the `tier' values, but since the calling
* function doesn't care, there's no point in removing the gaps...) */
for (i=0, in=n; i<in; ++i)
for (j=i+1, jn=n; j<jn; ++j)
if ((tmp[i].info.tier!=tmp[j].info.tier)
&& (tmp[i].port==tmp[j].port)
&& !tr_strcmp0 (tmp[i].host,tmp[j].host)
&& !tr_strcmp0 (tmp[i].path,tmp[j].path))
tmp[j].info.tier = tmp[i].info.tier;
/* sort them, for two reasons:
* (1) unjumble the tiers from the previous step
* (2) move the UDP trackers to the front of each tier */
qsort (tmp, n, sizeof (struct ann_tracker_info), filter_trackers_compare_func);
/* build the output */
*setme_count = n;
ret = tr_new0 (tr_tracker_info, n);
for (i=0, in=n; i<in; ++i)
ret[i] = tmp[i].info;
/* cleanup */
for (i=0, in=n; i<in; ++i) {
tr_free (tmp[i].path);
tr_free (tmp[i].host);
tr_free (tmp[i].scheme);
}
tr_free (tmp);
/*for (i=0, in=n; i<in; ++i) fprintf (stderr, "OUT: [%d][%s]\n", ret[i].tier, ret[i].announce);*/
return ret;
}
static void
addTorrentToTier (tr_torrent_tiers * tt, tr_torrent * tor)
{
int i, n;
int tier_count;
tr_tier * tier;
tr_tracker_info * infos = filter_trackers (tor->info.trackers,
tor->info.trackerCount, &n);
/* build the array of trackers */
tt->trackers = tr_new0 (tr_tracker, n);
tt->tracker_count = n;
for (i=0; i<n; ++i)
trackerConstruct (&tt->trackers[i], &infos[i]);
/* count how many tiers there are */
tier_count = 0;
for (i=0; i<n; ++i)
if (!i || (infos[i].tier != infos[i-1].tier))
++tier_count;
/* build the array of tiers */
tier = NULL;
tt->tiers = tr_new0 (tr_tier, tier_count);
tt->tier_count = 0;
for (i=0; i<n; ++i) {
if (i && (infos[i].tier == infos[i-1].tier))
++tier->tracker_count;
else {
tier = &tt->tiers[tt->tier_count++];
tierConstruct (tier, tor);
tier->trackers = &tt->trackers[i];
tier->tracker_count = 1;
tierIncrementTracker (tier);
}
}
/* cleanup */
tr_free (infos);
}
tr_torrent_tiers *
tr_announcerAddTorrent (tr_torrent * tor,
tr_tracker_callback * callback,
void * callbackData)
{
tr_torrent_tiers * tiers;
assert (tr_isTorrent (tor));
tiers = tiersNew ();
tiers->callback = callback;
tiers->callbackData = callbackData;
addTorrentToTier (tiers, tor);
return tiers;
}
/***
****
***/
static bool
tierCanManualAnnounce (const tr_tier * tier)
{
return tier->manualAnnounceAllowedAt <= tr_time ();
}
bool
tr_announcerCanManualAnnounce (const tr_torrent * tor)
{
int i;
struct tr_torrent_tiers * tt = NULL;
assert (tr_isTorrent (tor));
assert (tor->tiers != NULL);
if (tor->isRunning)
tt = tor->tiers;
/* return true if any tier can manual announce */
for (i=0; tt && i<tt->tier_count; ++i)
if (tierCanManualAnnounce (&tt->tiers[i]))
return true;
return false;
}
time_t
tr_announcerNextManualAnnounce (const tr_torrent * tor)
{
int i;
time_t ret = ~ (time_t)0;
struct tr_torrent_tiers * tt = tor->tiers;
/* find the earliest manual announce time from all peers */
for (i=0; tt && i<tt->tier_count; ++i)
if (tt->tiers[i].isRunning)
ret = MIN (ret, tt->tiers[i].manualAnnounceAllowedAt);
return ret;
}
static void
dbgmsg_tier_announce_queue (const tr_tier * tier)
{
if (tr_deepLoggingIsActive ())
{
int i;
char name[128];
char * message;
struct evbuffer * buf = evbuffer_new ();
tier_build_log_name (tier, name, sizeof (name));
for (i=0; i<tier->announce_event_count; ++i)
{
const tr_announce_event e = tier->announce_events[i];
const char * str = tr_announce_event_get_string (e);
evbuffer_add_printf (buf, "[%d:%s]", i, str);
}
message = evbuffer_free_to_str (buf);
tr_deepLog (__FILE__, __LINE__, name, "announce queue is %s", message);
tr_free (message);
}
}
static void
tier_announce_remove_trailing (tr_tier * tier, tr_announce_event e)
{
while ((tier->announce_event_count > 0)
&& (tier->announce_events[tier->announce_event_count-1] == e))
--tier->announce_event_count;
}
static void
tier_announce_event_push (tr_tier * tier,
tr_announce_event e,
time_t announceAt)
{
int i;
assert (tier != NULL);
dbgmsg_tier_announce_queue (tier);
dbgmsg (tier, "queued \"%s\"", tr_announce_event_get_string (e));
if (tier->announce_event_count > 0)
{
/* special case #1: if we're adding a "stopped" event,
* dump everything leading up to it except "completed" */
if (e == TR_ANNOUNCE_EVENT_STOPPED) {
bool has_completed = false;
const tr_announce_event c = TR_ANNOUNCE_EVENT_COMPLETED;
for (i=0; !has_completed && i<tier->announce_event_count; ++i)
has_completed = c == tier->announce_events[i];
tier->announce_event_count = 0;
if (has_completed)
tier->announce_events[tier->announce_event_count++] = c;
}
/* special case #2: dump all empty strings leading up to this event */
tier_announce_remove_trailing (tier, TR_ANNOUNCE_EVENT_NONE);
/* special case #3: no consecutive duplicates */
tier_announce_remove_trailing (tier, e);
}
/* make room in the array for another event */
if (tier->announce_event_alloc <= tier->announce_event_count) {
tier->announce_event_alloc += 4;
tier->announce_events = tr_renew (tr_announce_event,
tier->announce_events,
tier->announce_event_alloc);
}
/* add it */
tier->announce_events[tier->announce_event_count++] = e;
tier->announceAt = announceAt;
dbgmsg_tier_announce_queue (tier);
dbgmsg (tier, "announcing in %d seconds", (int)difftime (announceAt,tr_time ()));
}
static tr_announce_event
tier_announce_event_pull (tr_tier * tier)
{
const tr_announce_event e = tier->announce_events[0];
tr_removeElementFromArray (tier->announce_events,
0, sizeof (tr_announce_event),
tier->announce_event_count--);
return e;
}
static void
torrentAddAnnounce (tr_torrent * tor, tr_announce_event e, time_t announceAt)
{
int i;
struct tr_torrent_tiers * tt = tor->tiers;
/* walk through each tier and tell them to announce */
for (i=0; i<tt->tier_count; ++i)
tier_announce_event_push (&tt->tiers[i], e, announceAt);
}
void
tr_announcerTorrentStarted (tr_torrent * tor)
{
torrentAddAnnounce (tor, TR_ANNOUNCE_EVENT_STARTED, tr_time ());
}
void
tr_announcerManualAnnounce (tr_torrent * tor)
{
torrentAddAnnounce (tor, TR_ANNOUNCE_EVENT_NONE, tr_time ());
}
void
tr_announcerTorrentStopped (tr_torrent * tor)
{
torrentAddAnnounce (tor, TR_ANNOUNCE_EVENT_STOPPED, tr_time ());
}
void
tr_announcerTorrentCompleted (tr_torrent * tor)
{
torrentAddAnnounce (tor, TR_ANNOUNCE_EVENT_COMPLETED, tr_time ());
}
void
tr_announcerChangeMyPort (tr_torrent * tor)
{
tr_announcerTorrentStarted (tor);
}
/***
****
***/
void
tr_announcerAddBytes (tr_torrent * tor, int type, uint32_t byteCount)
{
int i;
struct tr_torrent_tiers * tt = tor->tiers;
assert (tr_isTorrent (tor));
assert (type==TR_ANN_UP || type==TR_ANN_DOWN || type==TR_ANN_CORRUPT);
for (i=0; i<tt->tier_count; ++i)
tt->tiers[i].byteCounts[ type ] += byteCount;
}
/***
****
***/
static tr_announce_request *
announce_request_new (const tr_announcer * announcer,
const tr_torrent * tor,
const tr_tier * tier,
tr_announce_event event)
{
tr_announce_request * req = tr_new0 (tr_announce_request, 1);
req->port = tr_sessionGetPublicPeerPort (announcer->session);
req->url = tr_strdup (tier->currentTracker->announce);
req->tracker_id_str = tr_strdup (tier->currentTracker->tracker_id_str);
memcpy (req->info_hash, tor->info.hash, SHA_DIGEST_LENGTH);
memcpy (req->peer_id, tor->peer_id, PEER_ID_LEN);
req->up = tier->byteCounts[TR_ANN_UP];
req->down = tier->byteCounts[TR_ANN_DOWN];
req->corrupt = tier->byteCounts[TR_ANN_CORRUPT];
req->leftUntilComplete = tr_torrentHasMetadata (tor)
? tor->info.totalSize - tr_cpHaveTotal (&tor->completion)
: ~ (uint64_t)0;
req->event = event;
req->numwant = event == TR_ANNOUNCE_EVENT_STOPPED ? 0 : NUMWANT;
req->key = announcer->key;
req->partial_seed = tr_cpGetStatus (&tor->completion) == TR_PARTIAL_SEED;
tier_build_log_name (tier, req->log_name, sizeof (req->log_name));
return req;
}
static void announce_request_free (tr_announce_request * req);
void
tr_announcerRemoveTorrent (tr_announcer * announcer, tr_torrent * tor)
{
struct tr_torrent_tiers * tt = tor->tiers;
if (tt != NULL)
{
int i;
for (i=0; i<tt->tier_count; ++i)
{
tr_tier * tier = &tt->tiers[i];
if (tier->isRunning)
{
const tr_announce_event e = TR_ANNOUNCE_EVENT_STOPPED;
tr_announce_request * req = announce_request_new (announcer, tor, tier, e);
if (tr_ptrArrayFindSorted (&announcer->stops, req, compareStops) != NULL)
announce_request_free (req);
else
tr_ptrArrayInsertSorted (&announcer->stops, req, compareStops);
}
}
tiersFree (tor->tiers);
tor->tiers = NULL;
}
}
static int
getRetryInterval (const tr_tracker * t)
{
int minutes;
const unsigned int jitter_seconds = tr_cryptoWeakRandInt (60);
switch (t->consecutiveFailures) {
case 0: minutes = 1; break;
case 1: minutes = 5; break;
case 2: minutes = 15; break;
case 3: minutes = 30; break;
case 4: minutes = 60; break;
default: minutes = 120; break;
}
return (minutes * 60) + jitter_seconds;
}
struct announce_data
{
int tierId;
time_t timeSent;
tr_announce_event event;
tr_session * session;
/** If the request succeeds, the value for tier's "isRunning" flag */
bool isRunningOnSuccess;
};
static void
on_announce_error (tr_tier * tier, const char * err, tr_announce_event e)
{
int interval;
/* increment the error count */
if (tier->currentTracker != NULL)
++tier->currentTracker->consecutiveFailures;
/* set the error message */
dbgmsg (tier, "%s", err);
tr_torinf (tier->tor, "%s", err);
tr_strlcpy (tier->lastAnnounceStr, err, sizeof (tier->lastAnnounceStr));
/* switch to the next tracker */
tierIncrementTracker (tier);
/* schedule a reannounce */
interval = getRetryInterval (tier->currentTracker);
dbgmsg (tier, "Retrying announce in %d seconds.", interval);
tr_torinf (tier->tor, "Retrying announce in %d seconds.", interval);
tier_announce_event_push (tier, e, tr_time () + interval);
}
static void
on_announce_done (const tr_announce_response * response,
void * vdata)
{
struct announce_data * data = vdata;
tr_announcer * announcer = data->session->announcer;
tr_tier * tier = getTier (announcer, response->info_hash, data->tierId);
const time_t now = tr_time ();
const tr_announce_event event = data->event;
if (announcer)
++announcer->slotsAvailable;
if (tier != NULL)
{
tr_tracker * tracker;
dbgmsg (tier, "Got announce response: "
"connected:%d "
"timeout:%d "
"seeders:%d "
"leechers:%d "
"downloads:%d "
"interval:%d "
"min_interval:%d "
"tracker_id_str:%s "
"pex:%zu "
"pex6:%zu "
"err:%s "
"warn:%s",
(int)response->did_connect,
(int)response->did_timeout,
response->seeders,
response->leechers,
response->downloads,
response->interval,
response->min_interval,
response->tracker_id_str ? response->tracker_id_str : "none",
response->pex_count,
response->pex6_count,
response->errmsg ? response->errmsg : "none",
response->warning ? response->warning : "none");
tier->lastAnnounceTime = now;
tier->lastAnnounceTimedOut = response->did_timeout;
tier->lastAnnounceSucceeded = false;
tier->isAnnouncing = false;
tier->manualAnnounceAllowedAt = now + tier->announceMinIntervalSec;
if (!response->did_connect)
{
on_announce_error (tier, _("Could not connect to tracker"), event);
}
else if (response->did_timeout)
{
on_announce_error (tier, _("Tracker did not respond"), event);
}
else if (response->errmsg)
{
/* If the torrent's only tracker returned an error, publish it.
Don't bother publishing if there are other trackers -- it's
all too common for people to load up dozens of dead trackers
in a torrent's metainfo... */
if (tier->tor->info.trackerCount < 2)
publishError (tier, response->errmsg);
on_announce_error (tier, response->errmsg, event);
}
else
{
int i;
const char * str;
int scrape_fields = 0;
int seeders = 0;
int leechers = 0;
int downloads = 0;
const bool isStopped = event == TR_ANNOUNCE_EVENT_STOPPED;
publishErrorClear (tier);
if ((tracker = tier->currentTracker))
{
tracker->consecutiveFailures = 0;
if (response->seeders >= 0)
{
tracker->seederCount = seeders = response->seeders;
++scrape_fields;
}
if (response->leechers >= 0)
{
tracker->leecherCount = leechers = response->leechers;
++scrape_fields;
}
if (response->downloads >= 0)
{
tracker->downloadCount = downloads = response->downloads;
++scrape_fields;
}
if ((str = response->tracker_id_str))
{
tr_free (tracker->tracker_id_str);
tracker->tracker_id_str = tr_strdup (str);
}
}
if ((str = response->warning))
{
tr_strlcpy (tier->lastAnnounceStr, str,
sizeof (tier->lastAnnounceStr));
dbgmsg (tier, "tracker gave \"%s\"", str);
publishWarning (tier, str);
}
else
{
tr_strlcpy (tier->lastAnnounceStr, _("Success"),
sizeof (tier->lastAnnounceStr));
}
if ((i = response->min_interval))
tier->announceMinIntervalSec = i;
if ((i = response->interval))
tier->announceIntervalSec = i;
if (response->pex_count > 0)
publishPeersPex (tier, seeders, leechers,
response->pex, response->pex_count);
if (response->pex6_count > 0)
publishPeersPex (tier, seeders, leechers,
response->pex6, response->pex6_count);
tier->isRunning = data->isRunningOnSuccess;
/* if the tracker included scrape fields in its announce response,
then a separate scrape isn't needed */
if ((scrape_fields >= 3) || (!tracker->scrape && (scrape_fields >= 1)))
{
tr_tordbg (tier->tor, "Announce response contained scrape info; "
"rescheduling next scrape to %d seconds from now.",
tier->scrapeIntervalSec);
tier->scrapeAt = get_next_scrape_time (announcer->session, tier, tier->scrapeIntervalSec);
tier->lastScrapeTime = now;
tier->lastScrapeSucceeded = true;
}
else if (tier->lastScrapeTime + tier->scrapeIntervalSec <= now)
{
tier->scrapeAt = get_next_scrape_time (announcer->session, tier, 0);
}
tier->lastAnnounceSucceeded = true;
tier->lastAnnouncePeerCount = response->pex_count
+ response->pex6_count;
if (isStopped)
{
/* now that we've successfully stopped the torrent,
* we can reset the up/down/corrupt count we've kept
* for this tracker */
tier->byteCounts[ TR_ANN_UP ] = 0;
tier->byteCounts[ TR_ANN_DOWN ] = 0;
tier->byteCounts[ TR_ANN_CORRUPT ] = 0;
}
if (!isStopped && !tier->announce_event_count)
{
/* the queue is empty, so enqueue a perodic update */
i = tier->announceIntervalSec;
dbgmsg (tier, "Sending periodic reannounce in %d seconds", i);
tier_announce_event_push (tier, TR_ANNOUNCE_EVENT_NONE, now + i);
}
}
}
tr_free (data);
}
static void
announce_request_free (tr_announce_request * req)
{
tr_free (req->tracker_id_str);
tr_free (req->url);
tr_free (req);
}
static void
announce_request_delegate (tr_announcer * announcer,
tr_announce_request * request,
tr_announce_response_func * callback,
void * callback_data)
{
tr_session * session = announcer->session;
if (!memcmp (request->url, "http", 4))
tr_tracker_http_announce (session, request, callback, callback_data);
else if (!memcmp (request->url, "udp://", 6))
tr_tracker_udp_announce (session, request, callback, callback_data);
else
tr_err ("Unsupported url: %s", request->url);
announce_request_free (request);
}
static void
tierAnnounce (tr_announcer * announcer, tr_tier * tier)
{
tr_announce_event announce_event;
tr_announce_request * req;
struct announce_data * data;
const tr_torrent * tor = tier->tor;
const time_t now = tr_time ();
assert (!tier->isAnnouncing);
assert (tier->announce_event_count > 0);
announce_event = tier_announce_event_pull (tier);
req = announce_request_new (announcer, tor, tier, announce_event);
data = tr_new0 (struct announce_data, 1);
data->session = announcer->session;
data->tierId = tier->key;
data->isRunningOnSuccess = tor->isRunning;
data->timeSent = now;
data->event = announce_event;
tier->isAnnouncing = true;
tier->lastAnnounceStartTime = now;
--announcer->slotsAvailable;
announce_request_delegate (announcer, req, on_announce_done, data);
}
/***
****
**** SCRAPE
****
***/
static void
on_scrape_error (tr_session * session, tr_tier * tier, const char * errmsg)
{
int interval;
/* increment the error count */
if (tier->currentTracker != NULL)
++tier->currentTracker->consecutiveFailures;
/* set the error message */
dbgmsg (tier, "Scrape error: %s", errmsg);
tr_torinf (tier->tor, "Scrape error: %s", errmsg);
tr_strlcpy (tier->lastScrapeStr, errmsg, sizeof (tier->lastScrapeStr));
/* switch to the next tracker */
tierIncrementTracker (tier);
/* schedule a rescrape */
interval = getRetryInterval (tier->currentTracker);
dbgmsg (tier, "Retrying scrape in %zu seconds.", (size_t)interval);
tr_torinf (tier->tor, "Retrying scrape in %zu seconds.", (size_t)interval);
tier->lastScrapeSucceeded = false;
tier->scrapeAt = get_next_scrape_time (session, tier, interval);
}
static tr_tier *
find_tier (tr_torrent * tor, const char * scrape)
{
int i;
struct tr_torrent_tiers * tt = tor->tiers;
for (i=0; tt && i<tt->tier_count; ++i) {
const tr_tracker * const tracker = tt->tiers[i].currentTracker;
if (tracker && !tr_strcmp0 (scrape, tracker->scrape))
return &tt->tiers[i];
}
return NULL;
}
static void
on_scrape_done (const tr_scrape_response * response, void * vsession)
{
int i;
const time_t now = tr_time ();
tr_session * session = vsession;
tr_announcer * announcer = session->announcer;
for (i=0; i<response->row_count; ++i)
{
const struct tr_scrape_response_row * row = &response->rows[i];
tr_torrent * tor = tr_torrentFindFromHash (session, row->info_hash);
if (tor != NULL)
{
tr_tier * tier = find_tier (tor, response->url);
if (tier != NULL)
{
dbgmsg (tier, "scraped url:%s -- "
"did_connect:%d "
"did_timeout:%d "
"seeders:%d "
"leechers:%d "
"downloads:%d "
"downloaders:%d "
"min_request_interval:%d "
"err:%s ",
response->url,
(int)response->did_connect,
(int)response->did_timeout,
row->seeders,
row->leechers,
row->downloads,
row->downloaders,
response->min_request_interval,
response->errmsg ? response->errmsg : "none");
tier->isScraping = false;
tier->lastScrapeTime = now;
tier->lastScrapeSucceeded = false;
tier->lastScrapeTimedOut = response->did_timeout;
if (!response->did_connect)
{
on_scrape_error (session, tier, _("Could not connect to tracker"));
}
else if (response->did_timeout)
{
on_scrape_error (session, tier, _("Tracker did not respond"));
}
else if (response->errmsg)
{
on_scrape_error (session, tier, response->errmsg);
}
else
{
tr_tracker * tracker;
tier->lastScrapeSucceeded = true;
tier->scrapeIntervalSec = MAX (DEFAULT_SCRAPE_INTERVAL_SEC,
response->min_request_interval);
tier->scrapeAt = get_next_scrape_time (session, tier, tier->scrapeIntervalSec);
tr_tordbg (tier->tor, "Scrape successful. Rescraping in %d seconds.",
tier->scrapeIntervalSec);
if ((tracker = tier->currentTracker))
{
if (row->seeders >= 0)
tracker->seederCount = row->seeders;
if (row->leechers >= 0)
tracker->leecherCount = row->leechers;
if (row->downloads >= 0)
tracker->downloadCount = row->downloads;
tracker->downloaderCount = row->downloaders;
tracker->consecutiveFailures = 0;
}
}
}
}
}
if (announcer)
++announcer->slotsAvailable;
}
static void
scrape_request_delegate (tr_announcer * announcer,
const tr_scrape_request * request,
tr_scrape_response_func * callback,
void * callback_data)
{
tr_session * session = announcer->session;
if (!memcmp (request->url, "http", 4))
tr_tracker_http_scrape (session, request, callback, callback_data);
else if (!memcmp (request->url, "udp://", 6))
tr_tracker_udp_scrape (session, request, callback, callback_data);
else
tr_err ("Unsupported url: %s", request->url);
}
static void
multiscrape (tr_announcer * announcer, tr_ptrArray * tiers)
{
int i;
int request_count = 0;
const time_t now = tr_time ();
const int tier_count = tr_ptrArraySize (tiers);
const int max_request_count = MIN (announcer->slotsAvailable, tier_count);
tr_scrape_request * requests = tr_new0 (tr_scrape_request, max_request_count);
/* batch as many info_hashes into a request as we can */
for (i=0; i<tier_count; ++i)
{
int j;
tr_tier * tier = tr_ptrArrayNth (tiers, i);
char * url = tier->currentTracker->scrape;
const uint8_t * hash = tier->tor->info.hash;
/* if there's a request with this scrape URL and a free slot, use it */
for (j=0; j<request_count; ++j)
{
tr_scrape_request * req = &requests[j];
if (req->info_hash_count >= TR_MULTISCRAPE_MAX)
continue;
if (tr_strcmp0 (req->url, url))
continue;
memcpy (req->info_hash[req->info_hash_count++], hash, SHA_DIGEST_LENGTH);
tier->isScraping = true;
tier->lastScrapeStartTime = now;
break;
}
/* otherwise, if there's room for another request, build a new one */
if ((j==request_count) && (request_count < max_request_count))
{
tr_scrape_request * req = &requests[request_count++];
req->url = url;
tier_build_log_name (tier, req->log_name, sizeof (req->log_name));
memcpy (req->info_hash[req->info_hash_count++], hash, SHA_DIGEST_LENGTH);
tier->isScraping = true;
tier->lastScrapeStartTime = now;
}
}
/* send the requests we just built */
for (i=0; i<request_count; ++i)
scrape_request_delegate (announcer, &requests[i], on_scrape_done, announcer->session);
/* cleanup */
tr_free (requests);
}
static void
flushCloseMessages (tr_announcer * announcer)
{
int i;
const int n = tr_ptrArraySize (&announcer->stops);
for (i=0; i<n; ++i)
announce_request_delegate (announcer, tr_ptrArrayNth (&announcer->stops, i), NULL, NULL);
tr_ptrArrayClear (&announcer->stops);
}
static bool
tierNeedsToAnnounce (const tr_tier * tier, const time_t now)
{
return !tier->isAnnouncing
&& !tier->isScraping
&& (tier->announceAt != 0)
&& (tier->announceAt <= now)
&& (tier->announce_event_count > 0);
}
static bool
tierNeedsToScrape (const tr_tier * tier, const time_t now)
{
return (!tier->isScraping)
&& (tier->scrapeAt != 0)
&& (tier->scrapeAt <= now)
&& (tier->currentTracker != NULL)
&& (tier->currentTracker->scrape != NULL);
}
static int
compareTiers (const void * va, const void * vb)
{
int ret;
const tr_tier * a = * (const tr_tier**)va;
const tr_tier * b = * (const tr_tier**)vb;
/* primary key: larger stats come before smaller */
ret = compareTransfer (a->byteCounts[TR_ANN_UP], a->byteCounts[TR_ANN_DOWN],
b->byteCounts[TR_ANN_UP], b->byteCounts[TR_ANN_DOWN]);
/* secondary key: announcements that have been waiting longer go first */
if (!ret && (a->announceAt != b->announceAt))
ret = a->announceAt < b->announceAt ? -1 : 1;
return ret;
}
static void
announceMore (tr_announcer * announcer)
{
int i;
int n;
tr_torrent * tor;
tr_ptrArray announceMe = TR_PTR_ARRAY_INIT;
tr_ptrArray scrapeMe = TR_PTR_ARRAY_INIT;
const time_t now = tr_time ();
dbgmsg (NULL, "announceMore: slotsAvailable is %d", announcer->slotsAvailable);
if (announcer->slotsAvailable < 1)
return;
/* build a list of tiers that need to be announced */
tor = NULL;
while ((tor = tr_torrentNext (announcer->session, tor))) {
struct tr_torrent_tiers * tt = tor->tiers;
for (i=0; tt && i<tt->tier_count; ++i) {
tr_tier * tier = &tt->tiers[i];
if (tierNeedsToAnnounce (tier, now))
tr_ptrArrayAppend (&announceMe, tier);
else if (tierNeedsToScrape (tier, now))
tr_ptrArrayAppend (&scrapeMe, tier);
}
}
/* if there are more tiers than slots available, prioritize */
n = tr_ptrArraySize (&announceMe);
if (n > announcer->slotsAvailable)
qsort (tr_ptrArrayBase (&announceMe), n, sizeof (tr_tier*), compareTiers);
/* announce some */
n = MIN (tr_ptrArraySize (&announceMe), announcer->slotsAvailable);
for (i=0; i<n; ++i) {
tr_tier * tier = tr_ptrArrayNth (&announceMe, i);
tr_tordbg (tier->tor, "%s", "Announcing to tracker");
dbgmsg (tier, "announcing tier %d of %d", i, n);
tierAnnounce (announcer, tier);
}
/* scrape some */
multiscrape (announcer, &scrapeMe);
/* cleanup */
tr_ptrArrayDestruct (&scrapeMe, NULL);
tr_ptrArrayDestruct (&announceMe, NULL);
}
static void
onUpkeepTimer (int foo UNUSED, short bar UNUSED, void * vannouncer)
{
tr_announcer * announcer = vannouncer;
tr_session * session = announcer->session;
const bool is_closing = session->isClosed;
const time_t now = tr_time ();
tr_sessionLock (session);
/* maybe send out some "stopped" messages for closed torrents */
flushCloseMessages (announcer);
/* maybe send out some announcements to trackers */
if (!is_closing)
announceMore (announcer);
/* TAU upkeep */
if (announcer->tauUpkeepAt <= now) {
announcer->tauUpkeepAt = now + TAU_UPKEEP_INTERVAL_SECS;
tr_tracker_udp_upkeep (session);
}
/* set up the next timer */
tr_timerAdd (announcer->upkeepTimer, UPKEEP_INTERVAL_SECS, 0);
tr_sessionUnlock (session);
}
/***
****
***/
tr_tracker_stat *
tr_announcerStats (const tr_torrent * torrent, int * setmeTrackerCount)
{
int i;
int out = 0;
tr_tracker_stat * ret;
struct tr_torrent_tiers * tt;
const time_t now = tr_time ();
assert (tr_isTorrent (torrent));
tt = torrent->tiers;
/* alloc the stats */
*setmeTrackerCount = tt->tracker_count;
ret = tr_new0 (tr_tracker_stat, tt->tracker_count);
/* populate the stats */
for (i=0; i<tt->tier_count; ++i)
{
int j;
const tr_tier * const tier = &tt->tiers[i];
for (j=0; j<tier->tracker_count; ++j)
{
const tr_tracker * const tracker = &tier->trackers[j];
tr_tracker_stat * st = &ret[out++];
st->id = tracker->id;
tr_strlcpy (st->host, tracker->key, sizeof (st->host));
tr_strlcpy (st->announce, tracker->announce, sizeof (st->announce));
st->tier = i;
st->isBackup = tracker != tier->currentTracker;
st->lastScrapeStartTime = tier->lastScrapeStartTime;
if (tracker->scrape)
tr_strlcpy (st->scrape, tracker->scrape, sizeof (st->scrape));
else
st->scrape[0] = '\0';
st->seederCount = tracker->seederCount;
st->leecherCount = tracker->leecherCount;
st->downloadCount = tracker->downloadCount;
if (st->isBackup)
{
st->scrapeState = TR_TRACKER_INACTIVE;
st->announceState = TR_TRACKER_INACTIVE;
st->nextScrapeTime = 0;
st->nextAnnounceTime = 0;
}
else
{
if ((st->hasScraped = tier->lastScrapeTime != 0)) {
st->lastScrapeTime = tier->lastScrapeTime;
st->lastScrapeSucceeded = tier->lastScrapeSucceeded;
st->lastScrapeTimedOut = tier->lastScrapeTimedOut;
tr_strlcpy (st->lastScrapeResult, tier->lastScrapeStr,
sizeof (st->lastScrapeResult));
}
if (tier->isScraping)
st->scrapeState = TR_TRACKER_ACTIVE;
else if (!tier->scrapeAt)
st->scrapeState = TR_TRACKER_INACTIVE;
else if (tier->scrapeAt > now)
{
st->scrapeState = TR_TRACKER_WAITING;
st->nextScrapeTime = tier->scrapeAt;
}
else
st->scrapeState = TR_TRACKER_QUEUED;
st->lastAnnounceStartTime = tier->lastAnnounceStartTime;
if ((st->hasAnnounced = tier->lastAnnounceTime != 0)) {
st->lastAnnounceTime = tier->lastAnnounceTime;
tr_strlcpy (st->lastAnnounceResult, tier->lastAnnounceStr,
sizeof (st->lastAnnounceResult));
st->lastAnnounceSucceeded = tier->lastAnnounceSucceeded;
st->lastAnnounceTimedOut = tier->lastAnnounceTimedOut;
st->lastAnnouncePeerCount = tier->lastAnnouncePeerCount;
}
if (tier->isAnnouncing)
st->announceState = TR_TRACKER_ACTIVE;
else if (!torrent->isRunning || !tier->announceAt)
st->announceState = TR_TRACKER_INACTIVE;
else if (tier->announceAt > now)
{
st->announceState = TR_TRACKER_WAITING;
st->nextAnnounceTime = tier->announceAt;
}
else
st->announceState = TR_TRACKER_QUEUED;
}
}
}
return ret;
}
void
tr_announcerStatsFree (tr_tracker_stat * trackers,
int trackerCount UNUSED)
{
tr_free (trackers);
}
/***
****
***/
static void
copy_tier_attributes_impl (struct tr_tier * tgt, int trackerIndex, const tr_tier * src)
{
const tr_tier keep = *tgt;
/* sanity clause */
assert (trackerIndex < tgt->tracker_count);
assert (!tr_strcmp0 (tgt->trackers[trackerIndex].announce, src->currentTracker->announce));
/* bitwise copy will handle most of tr_tier's fields... */
*tgt = *src;
/* ...fix the fields that can't be cleanly bitwise-copied */
tgt->wasCopied = true;
tgt->trackers = keep.trackers;
tgt->tracker_count = keep.tracker_count;
tgt->announce_events = tr_memdup (src->announce_events, sizeof (tr_announce_event) * src->announce_event_count);
tgt->announce_event_count = src->announce_event_count;
tgt->announce_event_alloc = src->announce_event_count;
tgt->currentTrackerIndex = trackerIndex;
tgt->currentTracker = &tgt->trackers[trackerIndex];
tgt->currentTracker->seederCount = src->currentTracker->seederCount;
tgt->currentTracker->leecherCount = src->currentTracker->leecherCount;
tgt->currentTracker->downloadCount = src->currentTracker->downloadCount;
tgt->currentTracker->downloaderCount = src->currentTracker->downloaderCount;
}
static void
copy_tier_attributes (struct tr_torrent_tiers * tt, const tr_tier * src)
{
int i, j;
bool found = false;
/* find a tier (if any) which has a match for src->currentTracker */
for (i=0; !found && i<tt->tier_count; ++i)
for (j=0; !found && j<tt->tiers[i].tracker_count; ++j)
if ((found = !tr_strcmp0 (src->currentTracker->announce, tt->tiers[i].trackers[j].announce)))
copy_tier_attributes_impl (&tt->tiers[i], j, src);
}
void
tr_announcerResetTorrent (tr_announcer * announcer UNUSED, tr_torrent * tor)
{
int i;
const time_t now = tr_time ();
struct tr_torrent_tiers * tt = tor->tiers;
tr_torrent_tiers old = *tt;
assert (tt != NULL);
/* remove the old tiers / trackers */
tt->tiers = NULL;
tt->trackers = NULL;
tt->tier_count = 0;
tt->tracker_count = 0;
/* create the new tiers / trackers */
addTorrentToTier (tt, tor);
/* copy the old tiers' states into their replacements */
for (i=0; i<old.tier_count; ++i)
if (old.tiers[i].currentTracker != NULL)
copy_tier_attributes (tt, &old.tiers[i]);
/* kickstart any tiers that didn't get started */
if (tor->isRunning)
for (i=0; i<tt->tier_count; ++i)
if (!tt->tiers[i].wasCopied)
tier_announce_event_push (&tt->tiers[i], TR_ANNOUNCE_EVENT_STARTED, now);
/* cleanup */
tiersDestruct (&old);
}