transmission/libtransmission/announcer-udp.c

973 lines
29 KiB
C

/*
* This file Copyright (C) 2010-2014 Mnemosyne LLC
*
* It may be used under the GNU GPL versions 2 or 3
* or any future license endorsed by Mnemosyne LLC.
*
* $Id$
*/
#define __LIBTRANSMISSION_ANNOUNCER_MODULE__
#include <errno.h> /* errno, EAFNOSUPPORT */
#include <string.h> /* memcpy (), memset () */
#include <event2/buffer.h>
#include <event2/dns.h>
#include <event2/util.h>
#include "transmission.h"
#include "announcer.h"
#include "announcer-common.h"
#include "crypto-utils.h" /* tr_rand_buffer () */
#include "log.h"
#include "peer-io.h"
#include "peer-mgr.h" /* tr_peerMgrCompactToPex () */
#include "ptrarray.h"
#include "tr-udp.h"
#include "utils.h"
#define dbgmsg(name, ...) \
do \
{ \
if (tr_logGetDeepEnabled ()) \
tr_logAddDeep (__FILE__, __LINE__, name, __VA_ARGS__); \
} \
while (0)
/****
*****
****/
static void
tau_sockaddr_setport (struct sockaddr * sa, tr_port port)
{
if (sa->sa_family == AF_INET)
((struct sockaddr_in *)sa)->sin_port = htons (port);
else if (sa->sa_family == AF_INET6)
((struct sockaddr_in6 *)sa)->sin6_port = htons (port);
}
static int
tau_sendto (tr_session * session,
struct evutil_addrinfo * ai, tr_port port,
const void * buf, size_t buflen)
{
tr_socket_t sockfd;
if (ai->ai_addr->sa_family == AF_INET)
sockfd = session->udp_socket;
else if (ai->ai_addr->sa_family == AF_INET6)
sockfd = session->udp6_socket;
else
sockfd = TR_BAD_SOCKET;
if (sockfd == TR_BAD_SOCKET) {
errno = EAFNOSUPPORT;
return -1;
}
tau_sockaddr_setport (ai->ai_addr, port);
return sendto (sockfd, buf, buflen, 0, ai->ai_addr, ai->ai_addrlen);
}
/****
*****
****/
static uint32_t
evbuffer_read_ntoh_32 (struct evbuffer * buf)
{
uint32_t val;
evbuffer_remove (buf, &val, sizeof (uint32_t));
return ntohl (val);
}
static uint64_t
evbuffer_read_ntoh_64 (struct evbuffer * buf)
{
uint64_t val;
evbuffer_remove (buf, &val, sizeof (uint64_t));
return tr_ntohll (val);
}
/****
*****
****/
typedef uint64_t tau_connection_t;
enum
{
TAU_CONNECTION_TTL_SECS = 60
};
typedef uint32_t tau_transaction_t;
static tau_transaction_t
tau_transaction_new (void)
{
tau_transaction_t tmp;
tr_rand_buffer (&tmp, sizeof (tau_transaction_t));
return tmp;
}
/* used in the "action" field of a request */
typedef enum
{
TAU_ACTION_CONNECT = 0,
TAU_ACTION_ANNOUNCE = 1,
TAU_ACTION_SCRAPE = 2,
TAU_ACTION_ERROR = 3
}
tau_action_t;
static bool
is_tau_response_message (tau_action_t action, size_t msglen)
{
if (action == TAU_ACTION_CONNECT) return msglen == 16;
if (action == TAU_ACTION_ANNOUNCE) return msglen >= 20;
if (action == TAU_ACTION_SCRAPE ) return msglen >= 20;
if (action == TAU_ACTION_ERROR ) return msglen >= 8;
return false;
}
enum
{
TAU_REQUEST_TTL = 60
};
/****
*****
***** SCRAPE
*****
****/
struct tau_scrape_request
{
void * payload;
size_t payload_len;
time_t sent_at;
time_t created_at;
tau_transaction_t transaction_id;
tr_scrape_response response;
tr_scrape_response_func callback;
void * user_data;
};
static struct tau_scrape_request *
tau_scrape_request_new (const tr_scrape_request * in,
tr_scrape_response_func callback,
void * user_data)
{
int i;
struct evbuffer * buf;
struct tau_scrape_request * req;
const tau_transaction_t transaction_id = tau_transaction_new ();
/* build the payload */
buf = evbuffer_new ();
evbuffer_add_hton_32 (buf, TAU_ACTION_SCRAPE);
evbuffer_add_hton_32 (buf, transaction_id);
for (i=0; i<in->info_hash_count; ++i)
evbuffer_add (buf, in->info_hash[i], SHA_DIGEST_LENGTH);
/* build the tau_scrape_request */
req = tr_new0 (struct tau_scrape_request, 1);
req->created_at = tr_time ();
req->transaction_id = transaction_id;
req->callback = callback;
req->user_data = user_data;
req->response.url = tr_strdup (in->url);
req->response.row_count = in->info_hash_count;
req->payload_len = evbuffer_get_length (buf);
req->payload = tr_memdup (evbuffer_pullup (buf, -1), req->payload_len);
for (i=0; i<req->response.row_count; ++i)
{
req->response.rows[i].seeders = -1;
req->response.rows[i].leechers = -1;
req->response.rows[i].downloads = -1;
memcpy (req->response.rows[i].info_hash,
in->info_hash[i], SHA_DIGEST_LENGTH);
}
/* cleanup */
evbuffer_free (buf);
return req;
}
static void
tau_scrape_request_free (struct tau_scrape_request * req)
{
tr_free (req->response.errmsg);
tr_free (req->response.url);
tr_free (req->payload);
tr_free (req);
}
static void
tau_scrape_request_finished (const struct tau_scrape_request * request)
{
if (request->callback != NULL)
request->callback (&request->response, request->user_data);
}
static void
tau_scrape_request_fail (struct tau_scrape_request * request,
bool did_connect,
bool did_timeout,
const char * errmsg)
{
request->response.did_connect = did_connect;
request->response.did_timeout = did_timeout;
request->response.errmsg = tr_strdup (errmsg);
tau_scrape_request_finished (request);
}
static void
on_scrape_response (struct tau_scrape_request * request,
tau_action_t action,
struct evbuffer * buf)
{
request->response.did_connect = true;
request->response.did_timeout = false;
if (action == TAU_ACTION_SCRAPE)
{
int i;
for (i=0; i<request->response.row_count; ++i)
{
struct tr_scrape_response_row * row;
if (evbuffer_get_length (buf) < (sizeof (uint32_t) * 3))
break;
row = &request->response.rows[i];
row->seeders = evbuffer_read_ntoh_32 (buf);
row->downloads = evbuffer_read_ntoh_32 (buf);
row->leechers = evbuffer_read_ntoh_32 (buf);
}
tau_scrape_request_finished (request);
}
else
{
char * errmsg;
const size_t buflen = evbuffer_get_length (buf);
if ((action == TAU_ACTION_ERROR) && (buflen > 0))
errmsg = tr_strndup (evbuffer_pullup (buf, -1), buflen);
else
errmsg = tr_strdup (_("Unknown error"));
tau_scrape_request_fail (request, true, false, errmsg);
tr_free (errmsg);
}
}
/****
*****
***** ANNOUNCE
*****
****/
struct tau_announce_request
{
void * payload;
size_t payload_len;
time_t created_at;
time_t sent_at;
tau_transaction_t transaction_id;
tr_announce_response response;
tr_announce_response_func callback;
void * user_data;
};
typedef enum
{
/* used in the "event" field of an announce request */
TAU_ANNOUNCE_EVENT_NONE = 0,
TAU_ANNOUNCE_EVENT_COMPLETED = 1,
TAU_ANNOUNCE_EVENT_STARTED = 2,
TAU_ANNOUNCE_EVENT_STOPPED = 3
}
tau_announce_event;
static tau_announce_event
get_tau_announce_event (tr_announce_event e)
{
switch (e)
{
case TR_ANNOUNCE_EVENT_COMPLETED: return TAU_ANNOUNCE_EVENT_COMPLETED;
case TR_ANNOUNCE_EVENT_STARTED: return TAU_ANNOUNCE_EVENT_STARTED;
case TR_ANNOUNCE_EVENT_STOPPED: return TAU_ANNOUNCE_EVENT_STOPPED;
default: return TAU_ANNOUNCE_EVENT_NONE;
}
}
static struct tau_announce_request *
tau_announce_request_new (const tr_announce_request * in,
tr_announce_response_func callback,
void * user_data)
{
struct evbuffer * buf;
struct tau_announce_request * req;
const tau_transaction_t transaction_id = tau_transaction_new ();
/* build the payload */
buf = evbuffer_new ();
evbuffer_add_hton_32 (buf, TAU_ACTION_ANNOUNCE);
evbuffer_add_hton_32 (buf, transaction_id);
evbuffer_add (buf, in->info_hash, SHA_DIGEST_LENGTH);
evbuffer_add (buf, in->peer_id, PEER_ID_LEN);
evbuffer_add_hton_64 (buf, in->down);
evbuffer_add_hton_64 (buf, in->leftUntilComplete);
evbuffer_add_hton_64 (buf, in->up);
evbuffer_add_hton_32 (buf, get_tau_announce_event (in->event));
evbuffer_add_hton_32 (buf, 0);
evbuffer_add_hton_32 (buf, in->key);
evbuffer_add_hton_32 (buf, in->numwant);
evbuffer_add_hton_16 (buf, in->port);
/* build the tau_announce_request */
req = tr_new0 (struct tau_announce_request, 1);
req->created_at = tr_time ();
req->transaction_id = transaction_id;
req->callback = callback;
req->user_data = user_data;
req->payload_len = evbuffer_get_length (buf);
req->payload = tr_memdup (evbuffer_pullup (buf, -1), req->payload_len);
req->response.seeders = -1;
req->response.leechers = -1;
req->response.downloads = -1;
memcpy (req->response.info_hash, in->info_hash, SHA_DIGEST_LENGTH);
evbuffer_free (buf);
return req;
}
static void
tau_announce_request_free (struct tau_announce_request * req)
{
tr_free (req->response.tracker_id_str);
tr_free (req->response.warning);
tr_free (req->response.errmsg);
tr_free (req->response.pex6);
tr_free (req->response.pex);
tr_free (req->payload);
tr_free (req);
}
static void
tau_announce_request_finished (const struct tau_announce_request * request)
{
if (request->callback != NULL)
request->callback (&request->response, request->user_data);
}
static void
tau_announce_request_fail (struct tau_announce_request * request,
bool did_connect,
bool did_timeout,
const char * errmsg)
{
request->response.did_connect = did_connect;
request->response.did_timeout = did_timeout;
request->response.errmsg = tr_strdup (errmsg);
tau_announce_request_finished (request);
}
static void
on_announce_response (struct tau_announce_request * request,
tau_action_t action,
struct evbuffer * buf)
{
const size_t buflen = evbuffer_get_length (buf);
request->response.did_connect = true;
request->response.did_timeout = false;
if ((action == TAU_ACTION_ANNOUNCE) && (buflen >= 3*sizeof (uint32_t)))
{
tr_announce_response * resp = &request->response;
resp->interval = evbuffer_read_ntoh_32 (buf);
resp->leechers = evbuffer_read_ntoh_32 (buf);
resp->seeders = evbuffer_read_ntoh_32 (buf);
resp->pex = tr_peerMgrCompactToPex (evbuffer_pullup (buf, -1),
evbuffer_get_length (buf),
NULL, 0,
&request->response.pex_count);
tau_announce_request_finished (request);
}
else
{
char * errmsg;
if ((action == TAU_ACTION_ERROR) && (buflen > 0))
errmsg = tr_strndup (evbuffer_pullup (buf, -1), buflen);
else
errmsg = tr_strdup (_("Unknown error"));
tau_announce_request_fail (request, true, false, errmsg);
tr_free (errmsg);
}
}
/****
*****
***** TRACKERS
*****
****/
struct tau_tracker
{
tr_session * session;
char * key;
char * host;
int port;
struct evdns_getaddrinfo_request * dns_request;
struct evutil_addrinfo * addr;
time_t addr_expiration_time;
time_t connecting_at;
time_t connection_expiration_time;
tau_connection_t connection_id;
tau_transaction_t connection_transaction_id;
time_t close_at;
tr_ptrArray announces;
tr_ptrArray scrapes;
};
static void tau_tracker_upkeep (struct tau_tracker *);
static void
tau_tracker_free (struct tau_tracker * t)
{
if (t->addr)
evutil_freeaddrinfo (t->addr);
if (t->dns_request != NULL)
evdns_getaddrinfo_cancel (t->dns_request);
tr_ptrArrayDestruct (&t->announces, (PtrArrayForeachFunc)tau_announce_request_free);
tr_ptrArrayDestruct (&t->scrapes, (PtrArrayForeachFunc)tau_scrape_request_free);
tr_free (t->host);
tr_free (t->key);
tr_free (t);
}
static void
tau_tracker_fail_all (struct tau_tracker * tracker,
bool did_connect,
bool did_timeout,
const char * errmsg)
{
int i;
int n;
tr_ptrArray * reqs;
/* fail all the scrapes */
reqs = &tracker->scrapes;
for (i=0, n=tr_ptrArraySize (reqs); i<n; ++i)
tau_scrape_request_fail (tr_ptrArrayNth (reqs, i),
did_connect, did_timeout, errmsg);
tr_ptrArrayDestruct (reqs, (PtrArrayForeachFunc)tau_scrape_request_free);
*reqs = TR_PTR_ARRAY_INIT;
/* fail all the announces */
reqs = &tracker->announces;
for (i=0, n=tr_ptrArraySize (reqs); i<n; ++i)
tau_announce_request_fail (tr_ptrArrayNth (reqs, i),
did_connect, did_timeout, errmsg);
tr_ptrArrayDestruct (reqs, (PtrArrayForeachFunc)tau_announce_request_free);
*reqs = TR_PTR_ARRAY_INIT;
}
static void
tau_tracker_on_dns (int errcode, struct evutil_addrinfo *addr, void * vtracker)
{
struct tau_tracker * tracker = vtracker;
tracker->dns_request = NULL;
if (errcode)
{
char * errmsg = tr_strdup_printf (_("DNS Lookup failed: %s"),
evdns_err_to_string (errcode));
dbgmsg (tracker->key, "%s", errmsg);
tau_tracker_fail_all (tracker, false, false, errmsg);
tr_free (errmsg);
}
else
{
dbgmsg (tracker->key, "DNS lookup succeeded");
tracker->addr = addr;
tracker->addr_expiration_time = tr_time () + (60*60); /* one hour */
tau_tracker_upkeep (tracker);
}
}
static void
tau_tracker_send_request (struct tau_tracker * tracker,
const void * payload,
size_t payload_len)
{
struct evbuffer * buf = evbuffer_new ();
dbgmsg (tracker->key, "sending request w/connection id %"PRIu64"\n",
tracker->connection_id);
evbuffer_add_hton_64 (buf, tracker->connection_id);
evbuffer_add_reference (buf, payload, payload_len, NULL, NULL);
tau_sendto (tracker->session, tracker->addr, tracker->port,
evbuffer_pullup (buf, -1),
evbuffer_get_length (buf));
evbuffer_free (buf);
}
static void
tau_tracker_send_reqs (struct tau_tracker * tracker)
{
int i, n;
tr_ptrArray * reqs;
const time_t now = tr_time ();
assert (tracker->dns_request == NULL);
assert (tracker->connecting_at == 0);
assert (tracker->addr != NULL);
assert (tracker->connection_expiration_time > now);
reqs = &tracker->announces;
for (i=0, n=tr_ptrArraySize (reqs); i<n; ++i) {
struct tau_announce_request * req = tr_ptrArrayNth (reqs, i);
if (!req->sent_at) {
dbgmsg (tracker->key, "sending announce req %p", (void*)req);
req->sent_at = now;
tau_tracker_send_request (tracker, req->payload, req->payload_len);
if (req->callback == NULL) {
tau_announce_request_free (req);
tr_ptrArrayRemove (reqs, i);
--i;
--n;
}
}
}
reqs = &tracker->scrapes;
for (i=0, n=tr_ptrArraySize (reqs); i<n; ++i) {
struct tau_scrape_request * req = tr_ptrArrayNth (reqs, i);
if (!req->sent_at) {
dbgmsg (tracker->key, "sending scrape req %p", (void*)req);
req->sent_at = now;
tau_tracker_send_request (tracker, req->payload, req->payload_len);
if (req->callback == NULL) {
tau_scrape_request_free (req);
tr_ptrArrayRemove (reqs, i);
--i;
--n;
}
}
}
}
static void
on_tracker_connection_response (struct tau_tracker * tracker,
tau_action_t action,
struct evbuffer * buf)
{
const time_t now = tr_time ();
tracker->connecting_at = 0;
tracker->connection_transaction_id = 0;
if (action == TAU_ACTION_CONNECT)
{
tracker->connection_id = evbuffer_read_ntoh_64 (buf);
tracker->connection_expiration_time = now + TAU_CONNECTION_TTL_SECS;
dbgmsg (tracker->key, "Got a new connection ID from tracker: %"PRIu64,
tracker->connection_id);
}
else
{
char * errmsg;
const size_t buflen = buf ? evbuffer_get_length (buf) : 0;
if ((action == TAU_ACTION_ERROR) && (buflen > 0))
errmsg = tr_strndup (evbuffer_pullup (buf, -1), buflen);
else
errmsg = tr_strdup (_("Connection failed"));
dbgmsg (tracker->key, "%s", errmsg);
tau_tracker_fail_all (tracker, true, false, errmsg);
tr_free (errmsg);
}
tau_tracker_upkeep (tracker);
}
static void
tau_tracker_timeout_reqs (struct tau_tracker * tracker)
{
int i, n;
tr_ptrArray * reqs;
const time_t now = time (NULL);
const bool cancel_all = tracker->close_at && (tracker->close_at <= now);
if (tracker->connecting_at && (tracker->connecting_at + TAU_REQUEST_TTL < now)) {
on_tracker_connection_response (tracker, TAU_ACTION_ERROR, NULL);
}
reqs = &tracker->announces;
for (i=0, n=tr_ptrArraySize (reqs); i<n; ++i) {
struct tau_announce_request * req = tr_ptrArrayNth (reqs, i);
if (cancel_all || (req->created_at + TAU_REQUEST_TTL < now)) {
dbgmsg (tracker->key, "timeout announce req %p", (void*)req);
tau_announce_request_fail (req, false, true, NULL);
tau_announce_request_free (req);
tr_ptrArrayRemove (reqs, i);
--i;
--n;
}
}
reqs = &tracker->scrapes;
for (i=0, n=tr_ptrArraySize (reqs); i<n; ++i) {
struct tau_scrape_request * req = tr_ptrArrayNth (reqs, i);
if (cancel_all || (req->created_at + TAU_REQUEST_TTL < now)) {
dbgmsg (tracker->key, "timeout scrape req %p", (void*)req);
tau_scrape_request_fail (req, false, true, NULL);
tau_scrape_request_free (req);
tr_ptrArrayRemove (reqs, i);
--i;
--n;
}
}
}
static bool
tau_tracker_is_idle (const struct tau_tracker * tracker)
{
return tr_ptrArrayEmpty (&tracker->announces)
&& tr_ptrArrayEmpty (&tracker->scrapes);
}
static void
tau_tracker_upkeep (struct tau_tracker * tracker)
{
const time_t now = tr_time ();
/* if the address info is too old, expire it */
if (tracker->addr && (tracker->addr_expiration_time <= now)) {
dbgmsg (tracker->host, "Expiring old DNS result");
evutil_freeaddrinfo (tracker->addr);
tracker->addr = NULL;
}
/* are there any requests pending? */
if (tau_tracker_is_idle (tracker))
return;
/* if we don't have an address yet, try & get one now. */
if (!tracker->addr && (tracker->dns_request == NULL))
{
struct evutil_addrinfo hints;
memset (&hints, 0, sizeof (hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;
dbgmsg (tracker->host, "Trying a new DNS lookup");
tracker->dns_request = evdns_getaddrinfo (tracker->session->evdns_base,
tracker->host, NULL, &hints,
tau_tracker_on_dns, tracker);
return;
}
dbgmsg (tracker->key, "addr %p -- connected %d (%"TR_PRIuSIZE" %"TR_PRIuSIZE") -- connecting_at %"TR_PRIuSIZE,
(void*)tracker->addr,
(int)(tracker->connection_expiration_time > now),
(size_t)tracker->connection_expiration_time,
(size_t)now,
(size_t)tracker->connecting_at);
/* also need a valid connection ID... */
if (tracker->addr
&& (tracker->connection_expiration_time <= now)
&& (!tracker->connecting_at))
{
struct evbuffer * buf = evbuffer_new ();
tracker->connecting_at = now;
tracker->connection_transaction_id = tau_transaction_new ();
dbgmsg (tracker->key, "Trying to connect. Transaction ID is %u",
tracker->connection_transaction_id);
evbuffer_add_hton_64 (buf, 0x41727101980LL);
evbuffer_add_hton_32 (buf, TAU_ACTION_CONNECT);
evbuffer_add_hton_32 (buf, tracker->connection_transaction_id);
tau_sendto (tracker->session, tracker->addr, tracker->port,
evbuffer_pullup (buf, -1),
evbuffer_get_length (buf));
evbuffer_free (buf);
return;
}
tau_tracker_timeout_reqs (tracker);
if ((tracker->addr != NULL) && (tracker->connection_expiration_time > now))
tau_tracker_send_reqs (tracker);
}
/****
*****
***** SESSION
*****
****/
struct tr_announcer_udp
{
/* tau_tracker */
tr_ptrArray trackers;
tr_session * session;
};
static struct tr_announcer_udp*
announcer_udp_get (tr_session * session)
{
struct tr_announcer_udp * tau;
if (session->announcer_udp != NULL)
return session->announcer_udp;
tau = tr_new0 (struct tr_announcer_udp, 1);
tau->trackers = TR_PTR_ARRAY_INIT;
tau->session = session;
session->announcer_udp = tau;
return tau;
}
/* Finds the tau_tracker struct that corresponds to this url.
If it doesn't exist yet, create one. */
static struct tau_tracker *
tau_session_get_tracker (struct tr_announcer_udp * tau, const char * url)
{
int i;
int n;
int port;
char * host;
char * key;
struct tau_tracker * tracker = NULL;
/* see if we've already got a tracker that matches this host + port */
tr_urlParse (url, -1, NULL, &host, &port, NULL);
key = tr_strdup_printf ("%s:%d", host, port);
for (i=0, n=tr_ptrArraySize (&tau->trackers); !tracker && i<n; ++i) {
struct tau_tracker * tmp = tr_ptrArrayNth (&tau->trackers, i);
if (!tr_strcmp0 (tmp->key, key))
tracker = tmp;
}
/* if we don't have a match, build a new tracker */
if (tracker == NULL)
{
tracker = tr_new0 (struct tau_tracker, 1);
tracker->session = tau->session;
tracker->key = key;
tracker->host = host;
tracker->port = port;
tracker->scrapes = TR_PTR_ARRAY_INIT;
tracker->announces = TR_PTR_ARRAY_INIT;
tr_ptrArrayAppend (&tau->trackers, tracker);
dbgmsg (tracker->key, "New tau_tracker created");
}
else
{
tr_free (key);
tr_free (host);
}
return tracker;
}
/****
*****
***** PUBLIC API
*****
****/
void
tr_tracker_udp_upkeep (tr_session * session)
{
struct tr_announcer_udp * tau = session->announcer_udp;
if (tau != NULL)
tr_ptrArrayForeach (&tau->trackers,
(PtrArrayForeachFunc)tau_tracker_upkeep);
}
bool
tr_tracker_udp_is_idle (const tr_session * session)
{
int i;
int n;
struct tr_announcer_udp * tau = session->announcer_udp;
if (tau != NULL)
for (i=0, n=tr_ptrArraySize (&tau->trackers); i<n; ++i)
if (!tau_tracker_is_idle (tr_ptrArrayNth (&tau->trackers, i)))
return false;
return true;
}
/* drop dead now. */
void
tr_tracker_udp_close (tr_session * session)
{
struct tr_announcer_udp * tau = session->announcer_udp;
if (tau != NULL)
{
session->announcer_udp = NULL;
tr_ptrArrayDestruct (&tau->trackers, (PtrArrayForeachFunc)tau_tracker_free);
tr_free (tau);
}
}
/* start shutting down.
This doesn't destroy everything if there are requests,
but sets a deadline on how much longer to wait for the remaining ones */
void
tr_tracker_udp_start_shutdown (tr_session * session)
{
const time_t now = time (NULL);
struct tr_announcer_udp * tau = session->announcer_udp;
if (tau != NULL)
{
int i, n;
for (i=0, n=tr_ptrArraySize (&tau->trackers); i<n; ++i)
{
struct tau_tracker * tracker = tr_ptrArrayNth (&tau->trackers, i);
tracker->close_at = now + 3;
tau_tracker_upkeep (tracker);
}
}
}
/* @brief process an incoming udp message if it's a tracker response.
* @return true if msg was a tracker response; false otherwise */
bool
tau_handle_message (tr_session * session, const uint8_t * msg, size_t msglen)
{
int i;
int n;
struct tr_announcer_udp * tau;
tau_action_t action_id;
tau_transaction_t transaction_id;
struct evbuffer * buf;
/*fprintf (stderr, "got an incoming udp message w/len %"TR_PRIuSIZE"\n", msglen);*/
if (!session || !session->announcer_udp)
return false;
if (msglen < (sizeof (uint32_t)*2))
return false;
/* extract the action_id and see if it makes sense */
buf = evbuffer_new ();
evbuffer_add_reference (buf, msg, msglen, NULL, NULL);
action_id = evbuffer_read_ntoh_32 (buf);
if (!is_tau_response_message (action_id, msglen)) {
evbuffer_free (buf);
return false;
}
/* extract the transaction_id and look for a match */
tau = session->announcer_udp;
transaction_id = evbuffer_read_ntoh_32 (buf);
/*fprintf (stderr, "UDP got a transaction_id %u...\n", transaction_id);*/
for (i=0, n=tr_ptrArraySize (&tau->trackers); i<n; ++i)
{
int j, jn;
tr_ptrArray * reqs;
struct tau_tracker * tracker = tr_ptrArrayNth (&tau->trackers, i);
/* is it a connection response? */
if (tracker->connecting_at
&& (transaction_id == tracker->connection_transaction_id))
{
dbgmsg (tracker->key, "%"PRIu32" is my connection request!", transaction_id);
on_tracker_connection_response (tracker, action_id, buf);
evbuffer_free (buf);
return true;
}
/* is it a response to one of this tracker's announces? */
reqs = &tracker->announces;
for (j=0, jn=tr_ptrArraySize (reqs); j<jn; ++j) {
struct tau_announce_request * req = tr_ptrArrayNth (reqs, j);
if (req->sent_at && (transaction_id == req->transaction_id)) {
dbgmsg (tracker->key, "%"PRIu32" is an announce request!", transaction_id);
tr_ptrArrayRemove (reqs, j);
on_announce_response (req, action_id, buf);
tau_announce_request_free (req);
evbuffer_free (buf);
return true;
}
}
/* is it a response to one of this tracker's scrapes? */
reqs = &tracker->scrapes;
for (j=0, jn=tr_ptrArraySize (reqs); j<jn; ++j) {
struct tau_scrape_request * req = tr_ptrArrayNth (reqs, j);
if (req->sent_at && (transaction_id == req->transaction_id)) {
dbgmsg (tracker->key, "%"PRIu32" is a scrape request!", transaction_id);
tr_ptrArrayRemove (reqs, j);
on_scrape_response (req, action_id, buf);
tau_scrape_request_free (req);
evbuffer_free (buf);
return true;
}
}
}
/* no match... */
evbuffer_free (buf);
return false;
}
void
tr_tracker_udp_announce (tr_session * session,
const tr_announce_request * request,
tr_announce_response_func response_func,
void * user_data)
{
struct tr_announcer_udp * tau = announcer_udp_get (session);
struct tau_tracker * tracker = tau_session_get_tracker (tau, request->url);
struct tau_announce_request * r = tau_announce_request_new (request,
response_func,
user_data);
tr_ptrArrayAppend (&tracker->announces, r);
tau_tracker_upkeep (tracker);
}
void
tr_tracker_udp_scrape (tr_session * session,
const tr_scrape_request * request,
tr_scrape_response_func response_func,
void * user_data)
{
struct tr_announcer_udp * tau = announcer_udp_get (session);
struct tau_tracker * tracker = tau_session_get_tracker (tau, request->url);
struct tau_scrape_request * r = tau_scrape_request_new (request,
response_func,
user_data);
tr_ptrArrayAppend (&tracker->scrapes, r);
tau_tracker_upkeep (tracker);
}