928 lines
26 KiB
C++
928 lines
26 KiB
C++
// This file Copyright © 2010-2022 Mnemosyne LLC.
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// It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only),
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// or any future license endorsed by Mnemosyne LLC.
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// License text can be found in the licenses/ folder.
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#include <cerrno> /* errno, EAFNOSUPPORT */
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#include <cstring> /* memset() */
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#include <ctime>
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#include <list>
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#include <string_view>
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#include <vector>
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#include <event2/buffer.h>
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#include <event2/dns.h>
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#include <event2/util.h>
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#include <fmt/core.h>
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#include <fmt/format.h>
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#define LIBTRANSMISSION_ANNOUNCER_MODULE
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#include "transmission.h"
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#include "announcer-common.h"
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#include "announcer.h"
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#include "crypto-utils.h" /* tr_rand_buffer() */
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#include "log.h"
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#include "peer-io.h"
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#include "peer-mgr.h" /* tr_peerMgrCompactToPex() */
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#include "session.h"
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#include "tr-assert.h"
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#include "tr-udp.h"
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#include "utils.h"
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#define logwarn(interned, msg) tr_logAddWarn(msg, (interned).sv())
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#define logdbg(interned, msg) tr_logAddDebug(msg, (interned).sv())
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#define logtrace(interned, msg) tr_logAddTrace(msg, (interned).sv())
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using namespace std::literals;
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/****
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*****
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****/
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static void tau_sockaddr_setport(struct sockaddr* sa, tr_port port)
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{
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if (sa->sa_family == AF_INET)
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{
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TR_DISCARD_ALIGN(sa, struct sockaddr_in*)->sin_port = htons(port);
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}
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else if (sa->sa_family == AF_INET6)
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{
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TR_DISCARD_ALIGN(sa, struct sockaddr_in6*)->sin6_port = htons(port);
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}
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}
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static int tau_sendto(tr_session const* session, struct evutil_addrinfo* ai, tr_port port, void const* buf, size_t buflen)
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{
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auto sockfd = tr_socket_t{};
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if (ai->ai_addr->sa_family == AF_INET)
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{
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sockfd = session->udp_socket;
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}
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else if (ai->ai_addr->sa_family == AF_INET6)
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{
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sockfd = session->udp6_socket;
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}
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else
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{
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sockfd = TR_BAD_SOCKET;
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}
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if (sockfd == TR_BAD_SOCKET)
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{
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errno = EAFNOSUPPORT;
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return -1;
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}
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tau_sockaddr_setport(ai->ai_addr, port);
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return sendto(sockfd, static_cast<char const*>(buf), buflen, 0, ai->ai_addr, ai->ai_addrlen);
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}
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/****
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*****
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****/
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static uint32_t evbuffer_read_ntoh_32(struct evbuffer* buf)
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{
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auto val = uint32_t{};
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evbuffer_remove(buf, &val, sizeof(uint32_t));
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return ntohl(val);
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}
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static uint64_t evbuffer_read_ntoh_64(struct evbuffer* buf)
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{
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auto val = uint64_t{};
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evbuffer_remove(buf, &val, sizeof(uint64_t));
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return tr_ntohll(val);
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}
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/****
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*****
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****/
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using tau_connection_t = uint64_t;
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static auto constexpr TauConnectionTtlSecs = int{ 60 };
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using tau_transaction_t = uint32_t;
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static tau_transaction_t tau_transaction_new()
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{
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auto tmp = tau_transaction_t{};
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tr_rand_buffer(&tmp, sizeof(tau_transaction_t));
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return tmp;
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}
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/* used in the "action" field of a request */
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enum tau_action_t
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{
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TAU_ACTION_CONNECT = 0,
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TAU_ACTION_ANNOUNCE = 1,
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TAU_ACTION_SCRAPE = 2,
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TAU_ACTION_ERROR = 3
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};
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static bool is_tau_response_message(tau_action_t action, size_t msglen)
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{
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if (action == TAU_ACTION_CONNECT)
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{
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return msglen == 16;
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}
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if (action == TAU_ACTION_ANNOUNCE)
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{
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return msglen >= 20;
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}
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if (action == TAU_ACTION_SCRAPE)
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{
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return msglen >= 20;
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}
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if (action == TAU_ACTION_ERROR)
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{
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return msglen >= 8;
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}
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return false;
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}
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static auto constexpr TauRequestTtl = int{ 60 };
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/****
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*****
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***** SCRAPE
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*****
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****/
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struct tau_scrape_request
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{
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void requestFinished()
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{
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if (callback != nullptr)
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{
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callback(&response, user_data);
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}
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}
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void fail(bool did_connect, bool did_timeout, std::string_view errmsg)
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{
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response.did_connect = did_connect;
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response.did_timeout = did_timeout;
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response.errmsg = errmsg;
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requestFinished();
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}
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void onResponse(tau_action_t action, evbuffer* buf)
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{
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response.did_connect = true;
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response.did_timeout = false;
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if (action == TAU_ACTION_SCRAPE)
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{
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for (int i = 0; i < response.row_count; ++i)
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{
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if (evbuffer_get_length(buf) < sizeof(uint32_t) * 3)
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{
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break;
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}
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auto& row = response.rows[i];
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row.seeders = evbuffer_read_ntoh_32(buf);
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row.downloads = evbuffer_read_ntoh_32(buf);
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row.leechers = evbuffer_read_ntoh_32(buf);
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}
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requestFinished();
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}
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else
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{
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size_t const buflen = evbuffer_get_length(buf);
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auto const errmsg = action == TAU_ACTION_ERROR && buflen > 0 ?
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std::string_view{ reinterpret_cast<char const*>(evbuffer_pullup(buf, -1)), buflen } :
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_("Unknown error");
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fail(true, false, errmsg);
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}
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}
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std::vector<uint8_t> payload;
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time_t sent_at;
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time_t created_at;
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tau_transaction_t transaction_id;
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tr_scrape_response response;
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tr_scrape_response_func callback;
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void* user_data;
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};
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static tau_scrape_request make_tau_scrape_request(
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tr_scrape_request const* in,
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tr_scrape_response_func callback,
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void* user_data)
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{
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tau_transaction_t const transaction_id = tau_transaction_new();
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/* build the payload */
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auto* buf = evbuffer_new();
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evbuffer_add_hton_32(buf, TAU_ACTION_SCRAPE);
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evbuffer_add_hton_32(buf, transaction_id);
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for (int i = 0; i < in->info_hash_count; ++i)
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{
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evbuffer_add(buf, std::data(in->info_hash[i]), std::size(in->info_hash[i]));
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}
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auto const* const payload_begin = evbuffer_pullup(buf, -1);
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auto const* const payload_end = payload_begin + evbuffer_get_length(buf);
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/* build the tau_scrape_request */
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auto req = tau_scrape_request{};
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req.callback = callback;
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req.created_at = tr_time();
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req.transaction_id = transaction_id;
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req.callback = callback;
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req.user_data = user_data;
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req.response.scrape_url = in->scrape_url;
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req.response.row_count = in->info_hash_count;
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req.payload.assign(payload_begin, payload_end);
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for (int i = 0; i < req.response.row_count; ++i)
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{
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req.response.rows[i].seeders = -1;
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req.response.rows[i].leechers = -1;
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req.response.rows[i].downloads = -1;
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req.response.rows[i].info_hash = in->info_hash[i];
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}
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/* cleanup */
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evbuffer_free(buf);
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return req;
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}
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/****
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*****
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***** ANNOUNCE
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*****
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****/
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struct tau_announce_request
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{
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void requestFinished()
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{
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if (this->callback != nullptr)
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{
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this->callback(&this->response, this->user_data);
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}
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}
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void fail(bool did_connect, bool did_timeout, std::string_view errmsg)
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{
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this->response.did_connect = did_connect;
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this->response.did_timeout = did_timeout;
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this->response.errmsg = errmsg;
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this->requestFinished();
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}
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void onResponse(tau_action_t action, struct evbuffer* buf)
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{
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size_t const buflen = evbuffer_get_length(buf);
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this->response.did_connect = true;
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this->response.did_timeout = false;
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if (action == TAU_ACTION_ANNOUNCE && buflen >= 3 * sizeof(uint32_t))
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{
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response.interval = evbuffer_read_ntoh_32(buf);
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response.leechers = evbuffer_read_ntoh_32(buf);
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response.seeders = evbuffer_read_ntoh_32(buf);
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response.pex = tr_peerMgrCompactToPex(evbuffer_pullup(buf, -1), evbuffer_get_length(buf), nullptr, 0);
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requestFinished();
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}
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else
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{
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auto const errmsg = action == TAU_ACTION_ERROR && buflen > 0 ?
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std::string_view{ reinterpret_cast<char const*>(evbuffer_pullup(buf, -1)), buflen } :
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_("Unknown error");
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fail(true, false, errmsg);
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}
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}
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std::vector<uint8_t> payload;
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time_t created_at = 0;
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time_t sent_at = 0;
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tau_transaction_t transaction_id = 0;
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tr_announce_response response = {};
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tr_announce_response_func callback = nullptr;
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void* user_data = nullptr;
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};
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enum tau_announce_event
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{
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/* used in the "event" field of an announce request */
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TAU_ANNOUNCE_EVENT_NONE = 0,
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TAU_ANNOUNCE_EVENT_COMPLETED = 1,
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TAU_ANNOUNCE_EVENT_STARTED = 2,
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TAU_ANNOUNCE_EVENT_STOPPED = 3
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};
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static tau_announce_event get_tau_announce_event(tr_announce_event e)
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{
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switch (e)
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{
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case TR_ANNOUNCE_EVENT_COMPLETED:
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return TAU_ANNOUNCE_EVENT_COMPLETED;
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case TR_ANNOUNCE_EVENT_STARTED:
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return TAU_ANNOUNCE_EVENT_STARTED;
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case TR_ANNOUNCE_EVENT_STOPPED:
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return TAU_ANNOUNCE_EVENT_STOPPED;
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default:
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return TAU_ANNOUNCE_EVENT_NONE;
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}
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}
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static tau_announce_request make_tau_announce_request(
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tr_announce_request const* in,
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tr_announce_response_func callback,
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void* user_data)
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{
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tau_transaction_t const transaction_id = tau_transaction_new();
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/* build the payload */
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auto* buf = evbuffer_new();
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evbuffer_add_hton_32(buf, TAU_ACTION_ANNOUNCE);
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evbuffer_add_hton_32(buf, transaction_id);
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evbuffer_add(buf, std::data(in->info_hash), std::size(in->info_hash));
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evbuffer_add(buf, std::data(in->peer_id), std::size(in->peer_id));
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evbuffer_add_hton_64(buf, in->down);
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evbuffer_add_hton_64(buf, in->leftUntilComplete);
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evbuffer_add_hton_64(buf, in->up);
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evbuffer_add_hton_32(buf, get_tau_announce_event(in->event));
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evbuffer_add_hton_32(buf, 0);
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evbuffer_add_hton_32(buf, in->key);
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evbuffer_add_hton_32(buf, in->numwant);
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evbuffer_add_hton_16(buf, in->port);
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auto const* const payload_begin = evbuffer_pullup(buf, -1);
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auto const* const payload_end = payload_begin + evbuffer_get_length(buf);
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/* build the tau_announce_request */
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auto req = tau_announce_request();
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req.created_at = tr_time();
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req.transaction_id = transaction_id;
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req.callback = callback;
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req.user_data = user_data;
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req.payload.assign(payload_begin, payload_end);
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req.response.seeders = -1;
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req.response.leechers = -1;
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req.response.downloads = -1;
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req.response.info_hash = in->info_hash;
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evbuffer_free(buf);
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return req;
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}
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/****
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*****
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***** TRACKERS
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*****
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****/
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struct tau_tracker
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{
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[[nodiscard]] auto isIdle() const
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{
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return std::empty(announces) && std::empty(scrapes) && dns_request == nullptr;
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}
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~tau_tracker()
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{
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if (this->addr != nullptr)
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{
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evutil_freeaddrinfo(this->addr);
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}
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}
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void failAll(bool did_connect, bool did_timeout, std::string_view errmsg)
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{
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for (auto& req : this->scrapes)
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{
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req.fail(did_connect, did_timeout, errmsg);
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}
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for (auto& req : this->announces)
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{
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req.fail(did_connect, did_timeout, errmsg);
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}
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this->scrapes.clear();
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this->announces.clear();
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}
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tr_session* const session;
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tr_interned_string const key;
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tr_interned_string const host;
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int const port;
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evdns_getaddrinfo_request* dns_request = nullptr;
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evutil_addrinfo* addr = nullptr;
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time_t addr_expiration_time = 0;
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time_t connecting_at = 0;
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time_t connection_expiration_time = 0;
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tau_connection_t connection_id = 0;
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tau_transaction_t connection_transaction_id = 0;
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time_t close_at = 0;
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std::list<tau_announce_request> announces;
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std::list<tau_scrape_request> scrapes;
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tau_tracker(tr_session* session_in, tr_interned_string key_in, tr_interned_string host_in, int port_in)
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: session{ session_in }
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, key{ key_in }
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, host{ host_in }
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, port{ port_in }
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{
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}
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};
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static void tau_tracker_upkeep(struct tau_tracker* /*tracker*/);
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static void tau_tracker_on_dns(int errcode, struct evutil_addrinfo* addr, void* vtracker)
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{
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auto* tracker = static_cast<struct tau_tracker*>(vtracker);
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tracker->dns_request = nullptr;
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tracker->addr_expiration_time = tr_time() + 60 * 60; /* one hour */
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if (errcode != 0)
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{
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auto const errmsg = fmt::format(
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_("Couldn't find address of tracker '{host}': {error} ({error_code})"),
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fmt::arg("host", tracker->host),
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fmt::arg("error", evutil_gai_strerror(errcode)),
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fmt::arg("error_code", errcode));
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logwarn(tracker->key, errmsg);
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tracker->failAll(false, false, errmsg.c_str());
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}
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else
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{
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logdbg(tracker->key, "DNS lookup succeeded");
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tracker->addr = addr;
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tau_tracker_upkeep(tracker);
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}
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}
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static void tau_tracker_send_request(struct tau_tracker* tracker, void const* payload, size_t payload_len)
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{
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struct evbuffer* buf = evbuffer_new();
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logdbg(tracker->key, fmt::format("sending request w/connection id {}", tracker->connection_id));
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evbuffer_add_hton_64(buf, tracker->connection_id);
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evbuffer_add_reference(buf, payload, payload_len, nullptr, nullptr);
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(void)tau_sendto(tracker->session, tracker->addr, tracker->port, evbuffer_pullup(buf, -1), evbuffer_get_length(buf));
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evbuffer_free(buf);
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}
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template<typename T>
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static void tau_tracker_send_requests(tau_tracker* tracker, std::list<T>& reqs)
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{
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auto const now = tr_time();
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for (auto it = std::begin(reqs); it != std::end(reqs);)
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{
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auto& req = *it;
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if (req.sent_at != 0) // it's already been sent; we're awaiting a response
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{
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++it;
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continue;
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}
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logdbg(tracker->key, fmt::format("sending req {}", fmt::ptr(&req)));
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req.sent_at = now;
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tau_tracker_send_request(tracker, std::data(req.payload), std::size(req.payload));
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if (req.callback != nullptr)
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{
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++it;
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continue;
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}
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// no response needed, so we can remove it now
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it = reqs.erase(it);
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}
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}
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static void tau_tracker_send_reqs(tau_tracker* tracker)
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{
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TR_ASSERT(tracker->dns_request == nullptr);
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TR_ASSERT(tracker->connecting_at == 0);
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TR_ASSERT(tracker->addr != nullptr);
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TR_ASSERT(tracker->connection_expiration_time > tr_time());
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tau_tracker_send_requests(tracker, tracker->announces);
|
|
tau_tracker_send_requests(tracker, tracker->scrapes);
|
|
}
|
|
|
|
static void on_tracker_connection_response(struct tau_tracker* tracker, tau_action_t action, struct evbuffer* buf)
|
|
{
|
|
time_t const 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 + TauConnectionTtlSecs;
|
|
logdbg(tracker->key, fmt::format("Got a new connection ID from tracker: {}", tracker->connection_id));
|
|
}
|
|
else
|
|
{
|
|
size_t const buflen = buf != nullptr ? evbuffer_get_length(buf) : 0;
|
|
|
|
auto const errmsg = action == TAU_ACTION_ERROR && buflen > 0 ?
|
|
std::string_view{ reinterpret_cast<char const*>(evbuffer_pullup(buf, -1)), buflen } :
|
|
std::string_view{ _("Connection failed") };
|
|
|
|
logdbg(tracker->key, errmsg);
|
|
tracker->failAll(true, false, errmsg);
|
|
}
|
|
|
|
tau_tracker_upkeep(tracker);
|
|
}
|
|
|
|
static void tau_tracker_timeout_reqs(struct tau_tracker* tracker)
|
|
{
|
|
time_t const now = time(nullptr);
|
|
bool const cancel_all = tracker->close_at != 0 && (tracker->close_at <= now);
|
|
|
|
if (tracker->connecting_at != 0 && tracker->connecting_at + TauRequestTtl < now)
|
|
{
|
|
on_tracker_connection_response(tracker, TAU_ACTION_ERROR, nullptr);
|
|
}
|
|
|
|
if (auto& reqs = tracker->announces; !std::empty(reqs))
|
|
{
|
|
for (auto it = std::begin(reqs); it != std::end(reqs);)
|
|
{
|
|
auto& req = *it;
|
|
if (cancel_all || req.created_at + TauRequestTtl < now)
|
|
{
|
|
logtrace(tracker->key, fmt::format("timeout announce req {}", fmt::ptr(&req)));
|
|
req.fail(false, true, "");
|
|
it = reqs.erase(it);
|
|
}
|
|
else
|
|
{
|
|
++it;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (auto& reqs = tracker->scrapes; !std::empty(reqs))
|
|
{
|
|
for (auto it = std::begin(reqs); it != std::end(reqs);)
|
|
{
|
|
auto& req = *it;
|
|
if (cancel_all || req.created_at + TauRequestTtl < now)
|
|
{
|
|
logtrace(tracker->key, fmt::format("timeout scrape req {}", fmt::ptr(&req)));
|
|
req.fail(false, true, "");
|
|
it = reqs.erase(it);
|
|
}
|
|
else
|
|
{
|
|
++it;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void tau_tracker_upkeep_ex(struct tau_tracker* tracker, bool timeout_reqs)
|
|
{
|
|
time_t const now = tr_time();
|
|
bool const closing = tracker->close_at != 0;
|
|
|
|
/* if the address info is too old, expire it */
|
|
if (tracker->addr != nullptr && (closing || tracker->addr_expiration_time <= now))
|
|
{
|
|
logtrace(tracker->host, "Expiring old DNS result");
|
|
evutil_freeaddrinfo(tracker->addr);
|
|
tracker->addr = nullptr;
|
|
tracker->addr_expiration_time = 0;
|
|
}
|
|
|
|
/* are there any requests pending? */
|
|
if (tracker->isIdle())
|
|
{
|
|
return;
|
|
}
|
|
|
|
// if DNS lookup *recently* failed for this host, do nothing
|
|
if (tracker->addr == nullptr && now < tracker->addr_expiration_time)
|
|
{
|
|
return;
|
|
}
|
|
|
|
/* if we don't have an address yet, try & get one now. */
|
|
if (!closing && tracker->addr == nullptr && tracker->dns_request == nullptr)
|
|
{
|
|
struct evutil_addrinfo hints;
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = AF_UNSPEC;
|
|
hints.ai_socktype = SOCK_DGRAM;
|
|
hints.ai_protocol = IPPROTO_UDP;
|
|
logtrace(tracker->host, "Trying a new DNS lookup");
|
|
tracker->dns_request = evdns_getaddrinfo(
|
|
tracker->session->evdns_base,
|
|
tr_strlower(tracker->host.sv()).c_str(),
|
|
nullptr,
|
|
&hints,
|
|
tau_tracker_on_dns,
|
|
tracker);
|
|
return;
|
|
}
|
|
|
|
logtrace(
|
|
tracker->key,
|
|
fmt::format(
|
|
"addr {} -- connected {} ({} {}) -- connecting_at {}",
|
|
fmt::ptr(tracker->addr),
|
|
tracker->connection_expiration_time > now,
|
|
tracker->connection_expiration_time,
|
|
now,
|
|
tracker->connecting_at));
|
|
|
|
/* also need a valid connection ID... */
|
|
if (tracker->addr != nullptr && tracker->connection_expiration_time <= now && tracker->connecting_at == 0)
|
|
{
|
|
struct evbuffer* buf = evbuffer_new();
|
|
tracker->connecting_at = now;
|
|
tracker->connection_transaction_id = tau_transaction_new();
|
|
logtrace(tracker->key, fmt::format("Trying to connect. Transaction ID is {}", 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);
|
|
(void)tau_sendto(tracker->session, tracker->addr, tracker->port, evbuffer_pullup(buf, -1), evbuffer_get_length(buf));
|
|
evbuffer_free(buf);
|
|
return;
|
|
}
|
|
|
|
if (timeout_reqs)
|
|
{
|
|
tau_tracker_timeout_reqs(tracker);
|
|
}
|
|
|
|
if (tracker->addr != nullptr && tracker->connection_expiration_time > now)
|
|
{
|
|
tau_tracker_send_reqs(tracker);
|
|
}
|
|
}
|
|
|
|
static void tau_tracker_upkeep(struct tau_tracker* tracker)
|
|
{
|
|
tau_tracker_upkeep_ex(tracker, true);
|
|
}
|
|
|
|
/****
|
|
*****
|
|
***** SESSION
|
|
*****
|
|
****/
|
|
|
|
struct tr_announcer_udp
|
|
{
|
|
explicit tr_announcer_udp(tr_session* session_in)
|
|
: session{ session_in }
|
|
{
|
|
}
|
|
|
|
std::list<tau_tracker> trackers;
|
|
|
|
tr_session* const session;
|
|
};
|
|
|
|
static struct tr_announcer_udp* announcer_udp_get(tr_session* session)
|
|
{
|
|
if (session->announcer_udp != nullptr)
|
|
{
|
|
return session->announcer_udp;
|
|
}
|
|
|
|
auto* const tau = new tr_announcer_udp(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 tau_tracker* tau_session_get_tracker(tr_announcer_udp* tau, tr_interned_string announce_url)
|
|
{
|
|
// build a lookup key for this tracker
|
|
auto const parsed = tr_urlParseTracker(announce_url);
|
|
TR_ASSERT(parsed);
|
|
if (!parsed)
|
|
{
|
|
return nullptr;
|
|
}
|
|
|
|
// see if we already have it
|
|
auto const key = tr_announcerGetKey(*parsed);
|
|
for (auto& tracker : tau->trackers)
|
|
{
|
|
if (tracker.key == key)
|
|
{
|
|
return &tracker;
|
|
}
|
|
}
|
|
|
|
// we don't have it -- build a new one
|
|
tau->trackers.emplace_back(tau->session, key, tr_interned_string(parsed->host), parsed->port);
|
|
auto* const tracker = &tau->trackers.back();
|
|
logtrace(tracker->key, "New tau_tracker created");
|
|
return tracker;
|
|
}
|
|
|
|
/****
|
|
*****
|
|
***** PUBLIC API
|
|
*****
|
|
****/
|
|
|
|
void tr_tracker_udp_upkeep(tr_session* session)
|
|
{
|
|
if (auto* const tau = session->announcer_udp; tau != nullptr)
|
|
{
|
|
for (auto& tracker : tau->trackers)
|
|
{
|
|
tau_tracker_upkeep(&tracker);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool tr_tracker_udp_is_idle(tr_session const* session)
|
|
{
|
|
auto const* tau = session->announcer_udp;
|
|
|
|
return tau == nullptr ||
|
|
std::all_of(std::begin(tau->trackers), std::end(tau->trackers), [](auto const& tracker) { return tracker.isIdle(); });
|
|
}
|
|
|
|
/* drop dead now. */
|
|
void tr_tracker_udp_close(tr_session* session)
|
|
{
|
|
if (auto* const tau = session->announcer_udp; tau != nullptr)
|
|
{
|
|
session->announcer_udp = nullptr;
|
|
delete 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)
|
|
{
|
|
time_t const now = time(nullptr);
|
|
|
|
if (auto* const tau = session->announcer_udp; tau != nullptr)
|
|
{
|
|
for (auto& tracker : tau->trackers)
|
|
{
|
|
if (tracker.dns_request != nullptr)
|
|
{
|
|
evdns_getaddrinfo_cancel(tracker.dns_request);
|
|
}
|
|
|
|
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, uint8_t const* msg, size_t msglen)
|
|
{
|
|
if (session == nullptr || session->announcer_udp == nullptr)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
if (msglen < sizeof(uint32_t) * 2)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
/* extract the action_id and see if it makes sense */
|
|
auto* const buf = evbuffer_new();
|
|
evbuffer_add_reference(buf, msg, msglen, nullptr, nullptr);
|
|
auto const action_id = tau_action_t(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 */
|
|
struct tr_announcer_udp* const tau = session->announcer_udp;
|
|
tau_transaction_t const transaction_id = evbuffer_read_ntoh_32(buf);
|
|
|
|
for (auto& tracker : tau->trackers)
|
|
{
|
|
// is it a connection response?
|
|
if (tracker.connecting_at != 0 && transaction_id == tracker.connection_transaction_id)
|
|
{
|
|
logtrace(tracker.key, fmt::format("{} 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?
|
|
if (auto& reqs = tracker.announces; !std::empty(reqs))
|
|
{
|
|
auto it = std::find_if(
|
|
std::begin(reqs),
|
|
std::end(reqs),
|
|
[&transaction_id](auto const& req) { return req.transaction_id == transaction_id; });
|
|
if (it != std::end(reqs))
|
|
{
|
|
logtrace(tracker.key, fmt::format("{} is an announce request!", transaction_id));
|
|
auto req = *it;
|
|
it = reqs.erase(it);
|
|
req.onResponse(action_id, buf);
|
|
evbuffer_free(buf);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// is it a response to one of this tracker's scrapes?
|
|
if (auto& reqs = tracker.scrapes; !std::empty(reqs))
|
|
{
|
|
auto it = std::find_if(
|
|
std::begin(reqs),
|
|
std::end(reqs),
|
|
[&transaction_id](auto const& req) { return req.transaction_id == transaction_id; });
|
|
if (it != std::end(reqs))
|
|
{
|
|
logtrace(tracker.key, fmt::format("{} is a scrape request!", transaction_id));
|
|
auto req = *it;
|
|
it = reqs.erase(it);
|
|
req.onResponse(action_id, buf);
|
|
evbuffer_free(buf);
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* no match... */
|
|
evbuffer_free(buf);
|
|
return false;
|
|
}
|
|
|
|
void tr_tracker_udp_announce(
|
|
tr_session* session,
|
|
tr_announce_request const* request,
|
|
tr_announce_response_func response_func,
|
|
void* user_data)
|
|
{
|
|
tr_announcer_udp* tau = announcer_udp_get(session);
|
|
tau_tracker* tracker = tau_session_get_tracker(tau, request->announce_url);
|
|
if (tracker == nullptr)
|
|
{
|
|
return;
|
|
}
|
|
|
|
tracker->announces.push_back(make_tau_announce_request(request, response_func, user_data));
|
|
tau_tracker_upkeep_ex(tracker, false);
|
|
}
|
|
|
|
void tr_tracker_udp_scrape(
|
|
tr_session* session,
|
|
tr_scrape_request const* request,
|
|
tr_scrape_response_func response_func,
|
|
void* user_data)
|
|
{
|
|
tr_announcer_udp* tau = announcer_udp_get(session);
|
|
tau_tracker* tracker = tau_session_get_tracker(tau, request->scrape_url);
|
|
if (tracker == nullptr)
|
|
{
|
|
return;
|
|
}
|
|
|
|
tracker->scrapes.push_back(make_tau_scrape_request(request, response_func, user_data));
|
|
tau_tracker_upkeep_ex(tracker, false);
|
|
}
|