Function CallMainChainRPC

src/mainchainrpc.cpp:81–152

#endif

UniValue CallMainChainRPC(const std::string& strMethod, const UniValue& params)
{
    std::string host = gArgs.GetArg("-mainchainrpchost", DEFAULT_RPCCONNECT);
    int port = gArgs.GetIntArg("-mainchainrpcport", BaseParams().MainchainRPCPort());

    // Obtain event base
    raii_event_base base = obtain_event_base();

    // Synchronously look up hostname
    raii_evhttp_connection evcon = obtain_evhttp_connection_base(base.get(), host, port);
    evhttp_connection_set_timeout(evcon.get(), gArgs.GetIntArg("-mainchainrpctimeout", DEFAULT_HTTP_CLIENT_TIMEOUT));

    HTTPReply response;
    raii_evhttp_request req = obtain_evhttp_request(http_request_done, (void*)&response);
    if (req == NULL)
        throw std::runtime_error("create http request failed");
#if LIBEVENT_VERSION_NUMBER >= 0x02010300
    evhttp_request_set_error_cb(req.get(), http_error_cb);
#endif

    // Get credentials
    std::string strRPCUserColonPass;
    if (gArgs.GetArg("-mainchainrpcpassword", "") == "") {
        // Try fall back to cookie-based authentication if no password is provided
        if (!GetMainchainAuthCookie(&strRPCUserColonPass)) {
            throw std::runtime_error(strprintf(
                _("Could not locate mainchain RPC credentials. No authentication cookie could be found, and no mainchainrpcpassword is set in the configuration file (%s)").translated,
                    gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME).c_str()));
        }
    } else {
        strRPCUserColonPass = gArgs.GetArg("-mainchainrpcuser", "") + ":" + gArgs.GetArg("-mainchainrpcpassword", "");
    }

    struct evkeyvalq* output_headers = evhttp_request_get_output_headers(req.get());
    assert(output_headers);
    evhttp_add_header(output_headers, "Host", host.c_str());
    evhttp_add_header(output_headers, "Connection", "close");
    evhttp_add_header(output_headers, "Authorization", (std::string("Basic ") + EncodeBase64(strRPCUserColonPass)).c_str());

    // Attach request data
    std::string strRequest = JSONRPCRequestObj(strMethod, params, 1).write() + "\n";
    struct evbuffer* output_buffer = evhttp_request_get_output_buffer(req.get());
    assert(output_buffer);
    evbuffer_add(output_buffer, strRequest.data(), strRequest.size());

    int r = evhttp_make_request(evcon.get(), req.get(), EVHTTP_REQ_POST, "/");
    req.release(); // ownership moved to evcon in above call
    if (r != 0) {
        throw CConnectionFailed("send http request failed");
    }

    event_base_dispatch(base.get());

    if (response.status == 0)
        throw CConnectionFailed(strprintf("couldn't connect to server: %s (code %d)\n(make sure server is running and you are connecting to the correct RPC port)", http_errorstring(response.error), response.error));
    else if (response.status == HTTP_UNAUTHORIZED)
        throw std::runtime_error("incorrect mainchainrpcuser or mainchainrpcpassword (authorization failed)");
    else if (response.status >= 400 && response.status != HTTP_BAD_REQUEST && response.status != HTTP_NOT_FOUND && response.status != HTTP_INTERNAL_SERVER_ERROR)