transmission/libtransmission/announcer-http.cc

513 lines
15 KiB
C++

// This file Copyright © 2010-2022 Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0), GPLv3 (SPDX: GPL-3.0),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#include <climits> /* USHRT_MAX */
#include <cstdio> /* fprintf() */
#include <cstring> /* strchr(), memcmp(), memcpy() */
#include <string>
#include <string_view>
#include <event2/buffer.h>
#include <event2/http.h> /* for HTTP_OK */
#define LIBTRANSMISSION_ANNOUNCER_MODULE
#include "transmission.h"
#include "announcer-common.h"
#include "log.h"
#include "net.h" /* tr_globalIPv6() */
#include "peer-mgr.h" /* pex */
#include "quark.h"
#include "torrent.h"
#include "trevent.h" /* tr_runInEventThread() */
#include "utils.h"
#include "variant.h"
#include "web.h"
#include "web-utils.h"
#define dbgmsg(name, ...) tr_logAddDeepNamed(name, __VA_ARGS__)
using namespace std::literals;
/****
*****
***** ANNOUNCE
*****
****/
static char const* get_event_string(tr_announce_request const* req)
{
return req->partial_seed && (req->event != TR_ANNOUNCE_EVENT_STOPPED) ? "paused" : tr_announce_event_get_string(req->event);
}
static std::string announce_url_new(tr_session const* session, tr_announce_request const* req)
{
auto const announce_sv = req->announce_url.sv();
auto escaped_info_hash = std::array<char, SHA_DIGEST_LENGTH * 3 + 1>{};
tr_http_escape_sha1(std::data(escaped_info_hash), req->info_hash);
auto* const buf = evbuffer_new();
evbuffer_expand(buf, 1024);
evbuffer_add_printf(
buf,
"%" TR_PRIsv
"%c"
"info_hash=%s"
"&peer_id=%" TR_PRIsv
"&port=%d"
"&uploaded=%" PRIu64 //
"&downloaded=%" PRIu64 //
"&left=%" PRIu64
"&numwant=%d"
"&key=%x"
"&compact=1"
"&supportcrypto=1",
TR_PRIsv_ARG(announce_sv),
announce_sv.find('?') == announce_sv.npos ? '?' : '&',
std::data(escaped_info_hash),
TR_PRIsv_ARG(req->peer_id),
req->port,
req->up,
req->down,
req->leftUntilComplete,
req->numwant,
req->key);
if (session->encryptionMode == TR_ENCRYPTION_REQUIRED)
{
evbuffer_add_printf(buf, "&requirecrypto=1");
}
if (req->corrupt != 0)
{
evbuffer_add_printf(buf, "&corrupt=%" PRIu64, req->corrupt);
}
if (char const* str = get_event_string(req); !tr_str_is_empty(str))
{
evbuffer_add_printf(buf, "&event=%s", str);
}
if (!std::empty(req->tracker_id))
{
evbuffer_add_printf(buf, "&trackerid=%" TR_PRIsv, TR_PRIsv_ARG(req->tracker_id));
}
/* There are two incompatible techniques for announcing an IPv6 address.
BEP-7 suggests adding an "ipv6=" parameter to the announce URL,
while OpenTracker requires that peers announce twice, once over IPv4
and once over IPv6.
To be safe, we should do both: add the "ipv6=" parameter and
announce twice. At any rate, we're already computing our IPv6
address (for the LTEP handshake), so this comes for free. */
unsigned char const* const ipv6 = tr_globalIPv6(session);
if (ipv6 != nullptr)
{
char ipv6_readable[INET6_ADDRSTRLEN];
evutil_inet_ntop(AF_INET6, ipv6, ipv6_readable, INET6_ADDRSTRLEN);
evbuffer_add_printf(buf, "&ipv6=");
tr_http_escape(buf, ipv6_readable, true);
}
return evbuffer_free_to_str(buf);
}
static auto listToPex(tr_variant* peerList)
{
size_t n = 0;
size_t const len = tr_variantListSize(peerList);
auto pex = std::vector<tr_pex>(len);
for (size_t i = 0; i < len; ++i)
{
tr_variant* const peer = tr_variantListChild(peerList, i);
if (peer == nullptr)
{
continue;
}
auto ip = std::string_view{};
if (!tr_variantDictFindStrView(peer, TR_KEY_ip, &ip))
{
continue;
}
auto addr = tr_address{};
if (!tr_address_from_string(&addr, ip))
{
continue;
}
auto port = int64_t{};
if (!tr_variantDictFindInt(peer, TR_KEY_port, &port))
{
continue;
}
if (port < 0 || port > USHRT_MAX)
{
continue;
}
if (!tr_address_is_valid_for_peers(&addr, port))
{
continue;
}
pex[n].addr = addr;
pex[n].port = htons((uint16_t)port);
++n;
}
pex.resize(n);
return pex;
}
struct announce_data
{
tr_announce_response response;
tr_announce_response_func response_func;
void* response_func_user_data;
char log_name[128];
};
static void on_announce_done_eventthread(void* vdata)
{
auto* data = static_cast<struct announce_data*>(vdata);
if (data->response_func != nullptr)
{
data->response_func(&data->response, data->response_func_user_data);
}
delete data;
}
static void on_announce_done(
tr_session* session,
bool did_connect,
bool did_timeout,
long response_code,
std::string_view msg,
void* vdata)
{
auto* data = static_cast<struct announce_data*>(vdata);
tr_announce_response* const response = &data->response;
response->did_connect = did_connect;
response->did_timeout = did_timeout;
dbgmsg(data->log_name, "Got announce response");
if (response_code != HTTP_OK)
{
auto const* const response_str = tr_webGetResponseStr(response_code);
response->errmsg = tr_strvJoin("Tracker HTTP response "sv, std::to_string(response_code), " ("sv, response_str, ")"sv);
}
else
{
tr_variant benc;
auto const variant_loaded = tr_variantFromBuf(&benc, TR_VARIANT_PARSE_BENC | TR_VARIANT_PARSE_INPLACE, msg);
if (tr_env_key_exists("TR_CURL_VERBOSE"))
{
if (!variant_loaded)
{
fprintf(stderr, "%s", "Announce response was not in benc format\n");
}
else
{
fprintf(stderr, "%s", "Announce response:\n< ");
for (auto const ch : tr_variantToStr(&benc, TR_VARIANT_FMT_JSON))
{
fputc(ch, stderr);
}
fputc('\n', stderr);
}
}
if (variant_loaded && tr_variantIsDict(&benc))
{
auto i = int64_t{};
auto sv = std::string_view{};
tr_variant* tmp = nullptr;
if (tr_variantDictFindStrView(&benc, TR_KEY_failure_reason, &sv))
{
response->errmsg = sv;
}
if (tr_variantDictFindStrView(&benc, TR_KEY_warning_message, &sv))
{
response->warning = sv;
}
if (tr_variantDictFindInt(&benc, TR_KEY_interval, &i))
{
response->interval = i;
}
if (tr_variantDictFindInt(&benc, TR_KEY_min_interval, &i))
{
response->min_interval = i;
}
if (tr_variantDictFindStrView(&benc, TR_KEY_tracker_id, &sv))
{
response->tracker_id = sv;
}
if (tr_variantDictFindInt(&benc, TR_KEY_complete, &i))
{
response->seeders = i;
}
if (tr_variantDictFindInt(&benc, TR_KEY_incomplete, &i))
{
response->leechers = i;
}
if (tr_variantDictFindInt(&benc, TR_KEY_downloaded, &i))
{
response->downloads = i;
}
if (tr_variantDictFindStrView(&benc, TR_KEY_peers6, &sv))
{
dbgmsg(data->log_name, "got a peers6 length of %zu", std::size(sv));
response->pex6 = tr_peerMgrCompact6ToPex(std::data(sv), std::size(sv), nullptr, 0);
}
if (tr_variantDictFindStrView(&benc, TR_KEY_peers, &sv))
{
dbgmsg(data->log_name, "got a compact peers length of %zu", std::size(sv));
response->pex = tr_peerMgrCompactToPex(std::data(sv), std::size(sv), nullptr, 0);
}
else if (tr_variantDictFindList(&benc, TR_KEY_peers, &tmp))
{
response->pex = listToPex(tmp);
dbgmsg(data->log_name, "got a peers list with %zu entries", std::size(response->pex));
}
}
if (variant_loaded)
{
tr_variantFree(&benc);
}
}
tr_runInEventThread(session, on_announce_done_eventthread, data);
}
void tr_tracker_http_announce(
tr_session* session,
tr_announce_request const* request,
tr_announce_response_func response_func,
void* response_func_user_data)
{
auto* const d = new announce_data{};
d->response.seeders = -1;
d->response.leechers = -1;
d->response.downloads = -1;
d->response_func = response_func;
d->response_func_user_data = response_func_user_data;
d->response.info_hash = request->info_hash;
tr_strlcpy(d->log_name, request->log_name, sizeof(d->log_name));
auto const url = announce_url_new(session, request);
dbgmsg(request->log_name, "Sending announce to libcurl: \"%" TR_PRIsv "\"", TR_PRIsv_ARG(url));
tr_webRun(session, url, on_announce_done, d);
}
/****
*****
***** SCRAPE
*****
****/
struct scrape_data
{
tr_scrape_response response;
tr_scrape_response_func response_func;
void* response_func_user_data;
char log_name[128];
};
static void on_scrape_done_eventthread(void* vdata)
{
auto* data = static_cast<struct scrape_data*>(vdata);
if (data->response_func != nullptr)
{
data->response_func(&data->response, data->response_func_user_data);
}
delete data;
}
static void on_scrape_done(
tr_session* session,
bool did_connect,
bool did_timeout,
long response_code,
std::string_view msg,
void* vdata)
{
auto* data = static_cast<struct scrape_data*>(vdata);
tr_scrape_response* response = &data->response;
response->did_connect = did_connect;
response->did_timeout = did_timeout;
auto const scrape_url_sv = response->scrape_url.sv();
dbgmsg(data->log_name, "Got scrape response for \"%" TR_PRIsv "\"", TR_PRIsv_ARG(scrape_url_sv));
if (response_code != HTTP_OK)
{
char const* fmt = _("Tracker gave HTTP response code %1$ld (%2$s)");
char const* response_str = tr_webGetResponseStr(response_code);
char buf[512];
tr_snprintf(buf, sizeof(buf), fmt, response_code, response_str);
response->errmsg = buf;
}
else
{
auto top = tr_variant{};
auto const variant_loaded = tr_variantFromBuf(&top, TR_VARIANT_PARSE_BENC | TR_VARIANT_PARSE_INPLACE, msg);
if (tr_env_key_exists("TR_CURL_VERBOSE"))
{
if (!variant_loaded)
{
fprintf(stderr, "%s", "Scrape response was not in benc format\n");
}
else
{
fprintf(stderr, "%s", "Scrape response:\n< ");
for (auto const ch : tr_variantToStr(&top, TR_VARIANT_FMT_JSON))
{
fputc(ch, stderr);
}
fputc('\n', stderr);
}
}
if (variant_loaded)
{
if (auto sv = std::string_view{}; tr_variantDictFindStrView(&top, TR_KEY_failure_reason, &sv))
{
response->errmsg = sv;
}
tr_variant* flags = nullptr;
auto intVal = int64_t{};
if (tr_variantDictFindDict(&top, TR_KEY_flags, &flags) &&
tr_variantDictFindInt(flags, TR_KEY_min_request_interval, &intVal))
{
response->min_request_interval = intVal;
}
tr_variant* files = nullptr;
if (tr_variantDictFindDict(&top, TR_KEY_files, &files))
{
auto key = tr_quark{};
tr_variant* val = nullptr;
for (int i = 0; tr_variantDictChild(files, i, &key, &val); ++i)
{
/* populate the corresponding row in our response array */
for (int j = 0; j < response->row_count; ++j)
{
struct tr_scrape_response_row* row = &response->rows[j];
// TODO(ckerr): ugh, interning info dict hashes is awful
auto const& hash = row->info_hash;
auto const key_sv = tr_quark_get_string_view(key);
if (std::size(hash) == std::size(key_sv) &&
memcmp(std::data(hash), std::data(key_sv), std::size(hash)) == 0)
{
if (tr_variantDictFindInt(val, TR_KEY_complete, &intVal))
{
row->seeders = intVal;
}
if (tr_variantDictFindInt(val, TR_KEY_incomplete, &intVal))
{
row->leechers = intVal;
}
if (tr_variantDictFindInt(val, TR_KEY_downloaded, &intVal))
{
row->downloads = intVal;
}
if (tr_variantDictFindInt(val, TR_KEY_downloaders, &intVal))
{
row->downloaders = intVal;
}
break;
}
}
}
}
tr_variantFree(&top);
}
}
tr_runInEventThread(session, on_scrape_done_eventthread, data);
}
static std::string scrape_url_new(tr_scrape_request const* req)
{
auto const sv = req->scrape_url.sv();
auto* const buf = evbuffer_new();
evbuffer_add(buf, std::data(sv), std::size(sv));
char delimiter = sv.find('?') == std::string_view::npos ? '?' : '&';
for (int i = 0; i < req->info_hash_count; ++i)
{
char str[SHA_DIGEST_LENGTH * 3 + 1];
tr_http_escape_sha1(str, req->info_hash[i]);
evbuffer_add_printf(buf, "%cinfo_hash=%s", delimiter, str);
delimiter = '&';
}
return evbuffer_free_to_str(buf);
}
void tr_tracker_http_scrape(
tr_session* session,
tr_scrape_request const* request,
tr_scrape_response_func response_func,
void* response_func_user_data)
{
auto* d = new scrape_data{};
d->response.scrape_url = request->scrape_url;
d->response_func = response_func;
d->response_func_user_data = response_func_user_data;
d->response.row_count = request->info_hash_count;
for (int i = 0; i < d->response.row_count; ++i)
{
d->response.rows[i].info_hash = request->info_hash[i];
d->response.rows[i].seeders = -1;
d->response.rows[i].leechers = -1;
d->response.rows[i].downloads = -1;
}
tr_strlcpy(d->log_name, request->log_name, sizeof(d->log_name));
auto const url = scrape_url_new(request);
dbgmsg(request->log_name, "Sending scrape to libcurl: \"%" TR_PRIsv "\"", TR_PRIsv_ARG(url));
tr_webRun(session, url, on_scrape_done, d);
}