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dhtnode.cpp

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    http.cpp 50.34 KiB
    /*
     *  Copyright (C) 2014-2020 Savoir-faire Linux Inc.
     *  Author: Vsevolod Ivanov <vsevolod.ivanov@savoirfairelinux.com>
     *
     *  This program is free software; you can redistribute it and/or modify
     *  it under the terms of the GNU General Public License as published by
     *  the Free Software Foundation; either version 3 of the License, or
     *  (at your option) any later version.
     *
     *  This program is distributed in the hope that it will be useful,
     *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     *  GNU General Public License for more details.
     *
     *  You should have received a copy of the GNU General Public License
     *  along with this program. If not, see <https://www.gnu.org/licenses/>.
     */
    
    #include "http.h"
    #include "log_enable.h"
    #include "crypto.h"
    #include "base64.h"
    #include "compat/os_cert.h"
    
    #include <asio.hpp>
    #include <restinio/impl/tls_socket.hpp>
    #include <http_parser.h>
    #include <json/json.h>
    
    #include <openssl/ocsp.h>
    #include <openssl/ssl.h>
    #include <openssl/asn1.h>
    #include <openssl/x509.h>
    #include <openssl/x509_vfy.h>
    
    #define MAXAGE_SEC (14*24*60*60)
    #define JITTER_SEC (60)
    #define OCSP_MAX_RESPONSE_SIZE (20480)
    #ifdef _WIN32
    #define timegm                 _mkgmtime
    #endif
    
    namespace dht {
    namespace http {
    
    constexpr const char HTTP_HEADER_CONTENT_TYPE_JSON[] = "application/json";
    constexpr const char HTTP_HEADER_DELIM[] = "\r\n\r\n";
    constexpr const char HTTP_PROTOCOL[] = "http://";
    constexpr const char HTTPS_PROTOCOL[] = "https://";
    constexpr const char ORIGIN_PROTOCOL[] = "//";
    constexpr unsigned MAX_REDIRECTS {5};
    
    Url::Url(const std::string& url): url(url)
    {
        size_t addr_begin = 0;
        // protocol
        const size_t proto_end = url.find("://");
        if (proto_end != std::string::npos){
            addr_begin = proto_end + 3;
            if (url.substr(0, proto_end) == "https"){
                protocol = "https";
            }
        }
        // host and service
        size_t addr_size = url.substr(addr_begin).find("/");
        if (addr_size == std::string::npos)
            addr_size = url.size() - addr_begin;
        auto host_service = splitPort(url.substr(addr_begin, addr_size));
        host = host_service.first;
        if (!host_service.second.empty())
            service = host_service.second;
        // target, query and fragment
        size_t query_begin = url.find("?");
        auto addr_end = addr_begin + addr_size;
        if (addr_end < url.size())
            target = url.substr(addr_end);
        size_t fragment_begin = url.find("#");
        if (fragment_begin == std::string::npos){
            query = url.substr(query_begin + 1);
        } else {
            target = url.substr(addr_end, fragment_begin - addr_end);
            query = url.substr(query_begin + 1, fragment_begin - query_begin - 1);
            fragment = url.substr(fragment_begin);
        }
    }
    
    std::string
    Url::toString() const
    {
        std::stringstream ss;
        if (not protocol.empty()) {
            ss << protocol << "://";
        }
        ss << host;
        if (not service.empty()) {
            ss << ':' << service;
        }
        ss << target;
        return ss.str();
    }
    
    // connection
    
    std::atomic_uint Connection::ids_ {1};
    
    std::shared_ptr<asio::ssl::context>
    newTlsClientContext(const std::shared_ptr<dht::Logger>& logger)
    {
        auto ctx = std::make_shared<asio::ssl::context>(asio::ssl::context::tls_client);
        ctx->set_verify_mode(asio::ssl::verify_peer | asio::ssl::verify_fail_if_no_peer_cert);
    
        if (char* path = getenv("CA_ROOT_FILE")) {
            if (logger)
                logger->d("Using CA file: %s", path);
            ctx->load_verify_file(path);
        } else if (char* path = getenv("CA_ROOT_PATH")) {
            if (logger)
                logger->d("Using CA path: %s", path);
            ctx->add_verify_path(path);
        } else {
    #ifdef __ANDROID__
            if (logger)
                logger->d("Using CA path: /system/etc/security/cacerts");
            ctx->add_verify_path("/system/etc/security/cacerts");
    #elif defined(WIN32) || defined(TARGET_OS_OSX)
            PEMCache::instance(logger).fillX509Store(ctx->native_handle());
    #else
            if (logger)
                logger->d("Using default CA path");
            ctx->set_default_verify_paths();
    #endif
        }
        return ctx;
    }
    
    Connection::Connection(asio::io_context& ctx, const bool ssl, std::shared_ptr<dht::Logger> l)
        : id_(Connection::ids_++), ctx_(ctx), istream_(&read_buf_), logger_(l)
    {
        if (ssl) {
            ssl_ctx_ = newTlsClientContext(l);
            ssl_socket_ = std::make_unique<ssl_socket_t>(ctx_, ssl_ctx_);
            if (logger_)
                logger_->d("[connection:%i] start https session with system CA", id_);
        }
        else {
            socket_ = std::make_unique<socket_t>(ctx);
            if (logger_)
                logger_->d("[connection:%i] start http session", id_);
        }
    }
    
    Connection::Connection(asio::io_context& ctx, std::shared_ptr<dht::crypto::Certificate> server_ca,
                           const dht::crypto::Identity& identity, std::shared_ptr<dht::Logger> l)
        : id_(Connection::ids_++), ctx_(ctx), istream_(&read_buf_), logger_(l)
    {
        asio::error_code ec;
        if (server_ca) {
            ssl_ctx_ = std::make_shared<asio::ssl::context>(asio::ssl::context::tls_client);
            ssl_ctx_->set_verify_mode(asio::ssl::verify_peer | asio::ssl::verify_fail_if_no_peer_cert);
            auto ca = server_ca->toString(false/*chain*/);
            ssl_ctx_->add_certificate_authority(asio::const_buffer{ca.data(), ca.size()}, ec);
            if (ec)
                throw std::runtime_error("Error adding certificate authority: " + ec.message());
            else if (logger_)
                logger_->d("[connection:%i] start https with custom CA %s", id_, server_ca->getUID().c_str());
        } else {
            ssl_ctx_ = newTlsClientContext(l);
            if (logger_)
                logger_->d("[connection:%i] start https session with system CA", id_);
        }
        if (identity.first){
            auto key = identity.first->serialize();
            ssl_ctx_->use_private_key(asio::const_buffer{key.data(), key.size()},
                                      asio::ssl::context::file_format::pem, ec);
            if (ec)
                throw std::runtime_error("Error setting client private key: " + ec.message());
        }
        if (identity.second){
            auto cert = identity.second->toString(true/*chain*/);
            ssl_ctx_->use_certificate_chain(asio::const_buffer{cert.data(), cert.size()}, ec);
            if (ec)
                throw std::runtime_error("Error adding client certificate: " + ec.message());
            else if (logger_)
                logger_->d("[connection:%i] client certificate %s", id_, identity.second->getUID().c_str());
        }
        ssl_socket_ = std::make_unique<ssl_socket_t>(ctx_, ssl_ctx_);
    }
    
    Connection::~Connection() {
        close();
    }
    
    void
    Connection::close()
    {
        std::lock_guard<std::mutex> lock(mutex_);
        asio::error_code ec;
        if (ssl_socket_) {
            if (ssl_socket_->is_open())
                ssl_socket_->close(ec);
        }
        else if (socket_) {
            if (socket_->is_open())
                socket_->close(ec);
        }
        if (ec and logger_)
            logger_->e("[connection:%i] error closing: %s", id_, ec.message().c_str());
    }
    
    bool
    Connection::is_open() const
    {
        if  (ssl_socket_) return ssl_socket_->is_open();
        else if (socket_) return socket_->is_open();
        else              return false;
    }
    
    bool
    Connection::is_ssl() const
    {
        return ssl_ctx_ ? true : false;
    }
    
    static time_t
    parse_ocsp_time(ASN1_GENERALIZEDTIME* gt)
    {
        struct tm tm;
        time_t rv = -1;
    
        if (gt == nullptr)
            return -1;
        // RFC 6960 specifies that all times in OCSP must be GENERALIZEDTIME
        if (ASN1_time_parse((const char*)gt->data, gt->length, &tm, V_ASN1_GENERALIZEDTIME) == -1)
            return -1;
        if ((rv = timegm(&tm)) == -1)
            return -1;
        return rv;
    }
    
    static inline X509*
    cert_from_chain(STACK_OF(X509)* fullchain)
    {
        return sk_X509_value(fullchain, 0);
    }
    
    static X509*
    issuer_from_chain(STACK_OF(X509)* fullchain)
    {
        X509 *cert, *issuer;
        X509_NAME *issuer_name;
    
        cert = cert_from_chain(fullchain);
        if ((issuer_name = X509_get_issuer_name(cert)) == nullptr)
            return nullptr;
    
        issuer = X509_find_by_subject(fullchain, issuer_name);
        return issuer;
    }
    
    using OscpRequestPtr = std::unique_ptr<OCSP_REQUEST, decltype(&OCSP_REQUEST_free)>;
    struct OscpRequestInfo {
        OscpRequestPtr req {nullptr, &OCSP_REQUEST_free};
        std::string data;
        std::string url;
    };
    
    static std::unique_ptr<OscpRequestInfo>
    ocspRequestFromCert(STACK_OF(X509)* fullchain, const std::shared_ptr<Logger>& logger, bool nonce = false)
    {
        if (fullchain == nullptr)
            return {};
    
        if (sk_X509_num(fullchain) <= 1) {
            if (logger)
                logger->e("Cert does not contain a cert chain");
            return {};
        }
        X509* cert = cert_from_chain(fullchain);
        if (cert == nullptr) {
            if (logger)
                logger->e("No certificate found");
            return {};
        }
        X509* issuer = issuer_from_chain(fullchain);
        if (issuer == nullptr) {
            if (logger)
                logger->e("Unable to find issuer for cert");
            return {};
        }
    
        auto urls = X509_get1_ocsp(cert);
        if (urls == nullptr || sk_OPENSSL_STRING_num(urls) <= 0) {
            if (logger)
                logger->e("Certificate contains no OCSP url");
            return {};
        }
        auto url = sk_OPENSSL_STRING_value(urls, 0);
        if (url == nullptr)
            return {};
    
        auto request = std::make_unique<OscpRequestInfo>();
        request->req = OscpRequestPtr(OCSP_REQUEST_new(), &OCSP_REQUEST_free);
        request->url = url;
        X509_email_free(urls);
    
        OCSP_CERTID* id = OCSP_cert_to_id(EVP_sha1(), cert, issuer);
        if (id == nullptr) {
            if (logger)
                logger->e("Unable to get certificate id from cert");
            return {};
        }
        if (OCSP_request_add0_id(request->req.get(), id) == nullptr) {
            if (logger)
                logger->e("Unable to add certificate id to request");
            return {};
        }
    
        if (nonce)
            OCSP_request_add1_nonce(request->req.get(), nullptr, -1);
    
        int size;
        uint8_t* data {nullptr};
        if ((size = i2d_OCSP_REQUEST(request->req.get(), &data)) <= 0) {
            if (logger)
                logger->e("Unable to encode ocsp request");
            return {};
        }
        if (data == nullptr) {
            if (logger)
                logger->e("Unable to allocte memory");
            return {};
        }
        request->data = std::string((char*)data, (char*)data+size);
        free(data);
        return request;
    }
    
    bool
    ocspValidateResponse(const OscpRequestInfo& info, STACK_OF(X509)* fullchain, const std::string& response, X509_STORE *store, const std::shared_ptr<Logger>& logger)
    {
        ASN1_GENERALIZEDTIME *revtime = nullptr, *thisupd = nullptr, *nextupd = nullptr;
        const uint8_t* p = (const uint8_t*)response.data();
        int status, cert_status=0, crl_reason=0;
        time_t now, rev_t = -1, this_t, next_t;
    
        X509* cert = cert_from_chain(fullchain);
        if (cert == nullptr) {
            if (logger)
                logger->e("No certificate found");
            return false;
        }
        X509* issuer = issuer_from_chain(fullchain);
        if (issuer == nullptr) {
            if (logger)
                logger->e("Unable to find issuer for cert");
            return false;
        }
    
        OCSP_CERTID *cidr;
        if ((cidr = OCSP_cert_to_id(nullptr, cert, issuer)) == nullptr) {
            if (logger)
                logger->e("Unable to get issuer cert/CID");
            return false;
        }
        std::unique_ptr<OCSP_CERTID, decltype(&OCSP_CERTID_free)> cid(cidr, &OCSP_CERTID_free);
    
        OCSP_RESPONSE *r;
        if ((r = d2i_OCSP_RESPONSE(nullptr, &p, response.size())) == nullptr) {
            if (logger)
                logger->e("OCSP response unserializable");
            return false;
        }
        std::unique_ptr<OCSP_RESPONSE, decltype(&OCSP_RESPONSE_free)> resp(r, &OCSP_RESPONSE_free);
    
        OCSP_BASICRESP *brespr;
        if ((brespr = OCSP_response_get1_basic(resp.get())) == nullptr) {
            if (logger)
                logger->e("Failed to load OCSP response");
            return false;
        }
        std::unique_ptr<OCSP_BASICRESP, decltype(&OCSP_BASICRESP_free)> bresp(brespr, &OCSP_BASICRESP_free);
    
        if (OCSP_basic_verify(bresp.get(), fullchain, store, OCSP_TRUSTOTHER) != 1) {
            if (logger)
                logger->w("OCSP verify failed");
            return false;
        }
        printf("OCSP response signature validated\n");
    
        status = OCSP_response_status(resp.get());
        if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) {
            if (logger)
                logger->w("OCSP Failure: code %d (%s)", status, OCSP_response_status_str(status));
            return false;
        }
    
        // Check the nonce if we sent one
        if (OCSP_check_nonce(info.req.get(), bresp.get()) <= 0) {
            if (logger)
                logger->w("No OCSP nonce, or mismatch");
            return false;
        }
    
        if (OCSP_resp_find_status(bresp.get(), cid.get(), &cert_status, &crl_reason,
            &revtime, &thisupd, &nextupd) != 1) {
            if (logger)
                logger->w("OCSP verify failed: no result for cert");
            return false;
        }
    
        if (revtime && (rev_t = parse_ocsp_time(revtime)) == -1) {
            if (logger)
                logger->w("Unable to parse revocation time in OCSP reply");
            return false;
        }
        // Belt and suspenders, Treat it as revoked if there is either
        // a revocation time, or status revoked.
        if (rev_t != -1 || cert_status == V_OCSP_CERTSTATUS_REVOKED) {
            if (logger)
                logger->w("Invalid OCSP reply: certificate is revoked");
            if (rev_t != -1) {
                if (logger)
                    logger->w("Certificate revoked at: %s", ctime(&rev_t));
            }
            return false;
        }
        if ((this_t = parse_ocsp_time(thisupd)) == -1) {
            if (logger)
                logger->w("unable to parse this update time in OCSP reply");
            return false;
        }
        if ((next_t = parse_ocsp_time(nextupd)) == -1) {
            if (logger)
                logger->w("unable to parse next update time in OCSP reply");
            return false;
        }
    
        // Don't allow this update to precede next update
        if (this_t >= next_t) {
            if (logger)
                logger->w("Invalid OCSP reply: this update >= next update");
            return false;
        }
    
        now = time(nullptr);
        // Check that this update is not more than JITTER seconds in the future.
        if (this_t > now + JITTER_SEC) {
            if (logger)
                logger->e("Invalid OCSP reply: this update is in the future (%s)", ctime(&this_t));
            return false;
        }
    
        // Check that this update is not more than MAXSEC in the past.
        if (this_t < now - MAXAGE_SEC) {
            if (logger)
                logger->e("Invalid OCSP reply: this update is too old (%s)", ctime(&this_t));
            return false;
        }
    
        // Check that next update is still valid
        if (next_t < now - JITTER_SEC) {
            if (logger)
                logger->w("Invalid OCSP reply: reply has expired (%s)", ctime(&next_t));
            return false;
        }
    
        if (logger) {
            logger->d("OCSP response validated");
            logger->d("	   This Update: %s", ctime(&this_t));
            logger->d("	   Next Update: %s", ctime(&next_t));
        }
        return true;
    }
    
    void
    Connection::set_ssl_verification(const std::string& hostname, const asio::ssl::verify_mode verify_mode)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (ssl_socket_) {
            // Set SNI Hostname (many hosts need this to handshake successfully)
            SSL_set_tlsext_host_name(ssl_socket_->asio_ssl_stream().native_handle(), hostname.c_str());
            ssl_socket_->asio_ssl_stream().set_verify_mode(verify_mode);
            if (verify_mode != asio::ssl::verify_none) {
                ssl_socket_->asio_ssl_stream().set_verify_callback([
                        id = id_, logger = logger_, hostname, checkOcsp = checkOcsp_
                    ] (bool preverified, asio::ssl::verify_context& ctx) -> bool {
                        X509* cert = X509_STORE_CTX_get_current_cert(ctx.native_handle());
                        if (logger) {
                            char subject_name[1024];
                            X509_NAME_oneline(X509_get_subject_name(cert), subject_name, 1024);
                            logger->d("[connection:%i] verify %s compliance to RFC 2818:\n%s", id, hostname.c_str(), subject_name);
                        }
    
                        // starts from CA and goes down the presented chain
                        auto verifier = asio::ssl::rfc2818_verification(hostname);
                        bool verified = verifier(preverified, ctx);
                        auto verify_ec = X509_STORE_CTX_get_error(ctx.native_handle());
                        if (verify_ec != 0 /*X509_V_OK*/ and logger)
                            logger->e("[http::connection:%i] ssl verification error=%i %d", id, verify_ec, verified);
                        if (verified and checkOcsp) {
                            std::unique_ptr<stack_st_X509, void(*)(stack_st_X509*)> chain(
                                X509_STORE_CTX_get1_chain(ctx.native_handle()),
                                [](stack_st_X509* c){ sk_X509_pop_free(c, X509_free); });
                            if (auto ocspInfo = ocspRequestFromCert(chain.get(), logger)) {
                                if (logger)
                                    logger->w("[http::connection:%i] TLS OCSP server: %s, request size: %zu", id, ocspInfo->url.c_str(), ocspInfo->data.size());
                                bool ocspVerified = false;
                                asio::io_context io_ctx;
                                auto ocspReq = std::make_shared<Request>(io_ctx, ocspInfo->url, [&](const Response& ocspResp){
                                    if (ocspResp.status_code == 200) {
                                        ocspVerified = ocspValidateResponse(*ocspInfo, chain.get(), ocspResp.body, X509_STORE_CTX_get0_store(ctx.native_handle()), logger);
                                    } else {
                                        if (logger)
                                            logger->w("[http::connection:%i] TLS OCSP check error", id);
                                    }
                                }, logger);
                                ocspReq->set_method(restinio::http_method_post());
                                ocspReq->set_header_field(restinio::http_field_t::content_type, "application/ocsp-request");
                                ocspReq->set_body(ocspInfo->data);
                                ocspReq->send();
                                io_ctx.run();
                                if (not ocspVerified)
                                    return false;
                            }
                        }
                        return verified;
                    }
                );
            }
        }
    }
    
    asio::streambuf&
    Connection::input()
    {
        return write_buf_;
    }
    
    std::string
    Connection::read_bytes(size_t bytes)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (bytes == 0)
            bytes = read_buf_.in_avail();
        std::string content;
        content.resize(bytes);
        auto rb = istream_.readsome(&content[0], bytes);
        content.resize(rb);
        return content;
    }
    
    std::string
    Connection::read_until(const char delim)
    {
        std::string content;
        std::getline(istream_, content, delim);
        return content;
    }
    
    void
    Connection::async_connect(std::vector<asio::ip::tcp::endpoint>&& endpoints, ConnectHandlerCb cb)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (!ssl_socket_ && !socket_) {
            cb(asio::error::operation_aborted, {});
            return;
        }
        auto& base = ssl_socket_? ssl_socket_->lowest_layer() : *socket_;
    
        ConnectHandlerCb wcb = [&base, cb=std::move(cb)](const asio::error_code& ec, const asio::ip::tcp::endpoint& endpoint) {
            if (!ec) {
                auto socket = base.native_handle();
                // Once connected, set a keep alive on the TCP socket with 30 seconds delay
                // This will generate broken pipes as soon as possible.
                // Note this needs to be done once connected to have a valid native_handle()
                uint32_t start = 30;
                uint32_t interval = 30;
                uint32_t cnt = 1;
    #ifdef _WIN32
                std::string val = "1";
                setsockopt(socket, SOL_SOCKET, SO_KEEPALIVE, val.c_str(), sizeof(val));
    
                // TCP_KEEPIDLE and TCP_KEEPINTVL are available since Win 10 version 1709
                // TCP_KEEPCNT since Win 10 version 1703
    #ifdef TCP_KEEPIDLE
                std::string start_str = std::to_string(start);
                setsockopt(socket, IPPROTO_TCP, TCP_KEEPIDLE,
                        start_str.c_str(), sizeof(start_str));
    #endif
    #ifdef TCP_KEEPINTVL
                std::string interval_str = std::to_string(interval);
                setsockopt(socket, IPPROTO_TCP, TCP_KEEPINTVL,
                        interval_str.c_str(), sizeof(interval_str));
    #endif
    #ifdef TCP_KEEPCNT
                std::string cnt_str = std::to_string(cnt);
                setsockopt(socket, IPPROTO_TCP, TCP_KEEPCNT,
                        cnt_str.c_str(), sizeof(cnt_str));
    #endif
    #else
                uint32_t val = 1;
                setsockopt(socket, SOL_SOCKET, SO_KEEPALIVE, &val, sizeof(uint32_t));
    #ifdef __APPLE__
                // Apple devices only have one parameter
                setsockopt(socket, IPPROTO_TCP, TCP_KEEPALIVE, &start, sizeof(uint32_t));
    #else
                // Linux based systems
                setsockopt(socket, SOL_TCP, TCP_KEEPIDLE, &start, sizeof(uint32_t));
                setsockopt(socket, SOL_TCP, TCP_KEEPINTVL, &interval, sizeof(uint32_t));
                setsockopt(socket, SOL_TCP, TCP_KEEPCNT, &cnt, sizeof(uint32_t));
    #endif
    #endif
            }
            if (cb)
                cb(ec, endpoint);
        };
        if (ssl_socket_)
            asio::async_connect(ssl_socket_->lowest_layer(), std::move(endpoints), wrapCallabck(std::move(wcb)));
        else
            asio::async_connect(*socket_, std::move(endpoints), wrapCallabck(std::move(wcb)));
    }
    
    void
    Connection::async_handshake(HandlerCb cb)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (ssl_socket_) {
            std::weak_ptr<Connection> wthis = shared_from_this();
            ssl_socket_->async_handshake(asio::ssl::stream<asio::ip::tcp::socket>::client,
                                        [wthis, cb](const asio::error_code& ec)
            {
                if (ec == asio::error::operation_aborted)
                    return;
                if (auto sthis = wthis.lock()) {
                    auto& this_ = *sthis;
                    auto verify_ec = SSL_get_verify_result(this_.ssl_socket_->asio_ssl_stream().native_handle());
                    if (this_.logger_) {
                        if (verify_ec == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT /*18*/
                            || verify_ec == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN /*19*/)
                            this_.logger_->d("[connection:%i] self-signed certificate in handshake: %i", this_.id_, verify_ec);
                        else if (verify_ec != X509_V_OK)
                            this_.logger_->e("[connection:%i] verify handshake error: %i", this_.id_, verify_ec);
                        else
                            this_.logger_->w("[connection:%i] verify handshake success", this_.id_);
                    }
                }
                if (cb)
                    cb(ec);
            });
        }
        else if (socket_)
            cb(asio::error::no_protocol_option);
        else if (cb)
            cb(asio::error::operation_aborted);
    }
    
    void
    Connection::async_write(BytesHandlerCb cb)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (!is_open()) {
            if (cb) ctx_.post([cb](){ cb(asio::error::broken_pipe, 0); });
            return;
        }
        if (ssl_socket_)  asio::async_write(*ssl_socket_, write_buf_, wrapCallabck(std::move(cb)));
        else if (socket_) asio::async_write(*socket_, write_buf_, wrapCallabck(std::move(cb)));
        else if (cb)      ctx_.post([cb](){ cb(asio::error::operation_aborted, 0); });
    }
    
    void
    Connection::async_read_until(const char* delim, BytesHandlerCb cb)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (!is_open()) {
            if (cb) ctx_.post([cb](){ cb(asio::error::broken_pipe, 0); });
            return;
        }
        if (ssl_socket_)  asio::async_read_until(*ssl_socket_, read_buf_, delim, wrapCallabck(std::move(cb)));
        else if (socket_) asio::async_read_until(*socket_, read_buf_, delim, wrapCallabck(std::move(cb)));
        else if (cb)      ctx_.post([cb](){ cb(asio::error::operation_aborted, 0); });
    }
    
    void
    Connection::async_read_until(char delim, BytesHandlerCb cb)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (!is_open()) {
            if (cb) ctx_.post([cb](){ cb(asio::error::broken_pipe, 0); });
            return;
        }
        if (ssl_socket_)  asio::async_read_until(*ssl_socket_, read_buf_, delim, wrapCallabck(std::move(cb)));
        else if (socket_) asio::async_read_until(*socket_, read_buf_, delim, wrapCallabck(std::move(cb)));
        else if (cb)      ctx_.post([cb](){ cb(asio::error::operation_aborted, 0); });
    }
    
    void
    Connection::async_read(size_t bytes, BytesHandlerCb cb)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (!is_open()) {
            if (cb) ctx_.post([cb](){ cb(asio::error::broken_pipe, 0); });
            return;
        }
        if (ssl_socket_)  asio::async_read(*ssl_socket_, read_buf_, asio::transfer_exactly(bytes), wrapCallabck(std::move(cb)));
        else if (socket_) asio::async_read(*socket_, read_buf_, asio::transfer_exactly(bytes), wrapCallabck(std::move(cb)));
        else if (cb)      ctx_.post([cb](){ cb(asio::error::operation_aborted, 0); });
    }
    
    void
    Connection::async_read_some(size_t bytes, BytesHandlerCb cb)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (!is_open()) {
            if (cb) ctx_.post([cb](){ cb(asio::error::broken_pipe, 0); });
            return;
        }
        auto buf = read_buf_.prepare(bytes);
        auto onEnd = [this_=shared_from_this(), cb=std::move(cb)](const asio::error_code& ec, size_t t){
            this_->read_buf_.commit(t);
            cb(ec, t);
        };
        if (ssl_socket_)  ssl_socket_->async_read_some(buf, onEnd);
        else              socket_->async_read_some(buf, onEnd);
    }
    
    void
    Connection::timeout(const std::chrono::seconds timeout, HandlerCb cb)
    {
        if (!is_open()){
            if (logger_)
                logger_->e("[connection:%i] closed, can't timeout", id_);
            if (cb)
                cb(asio::error::operation_aborted);
            return;
        }
        if (!timeout_timer_)
            timeout_timer_ = std::make_unique<asio::steady_timer>(ctx_);
        timeout_timer_->expires_at(std::chrono::steady_clock::now() + timeout);
        timeout_timer_->async_wait([id=id_, logger=logger_, cb](const asio::error_code &ec){
            if (ec == asio::error::operation_aborted)
                return;
            else if (ec){
                if (logger)
                    logger->e("[connection:%i] timeout error: %s", id, ec.message().c_str());
            }
            if (cb)
                cb(ec);
        });
    }
    
    // Resolver
    
    Resolver::Resolver(asio::io_context& ctx, const std::string& url, std::shared_ptr<dht::Logger> logger)
        : url_(url), resolver_(ctx), destroyed_(std::make_shared<bool>(false)), logger_(logger)
    {
        resolve(url_.host, url_.service.empty() ? url_.protocol : url_.service);
    }
    
    Resolver::Resolver(asio::io_context& ctx, const std::string& host, const std::string& service,
                       const bool ssl, std::shared_ptr<dht::Logger> logger)
        : resolver_(ctx), destroyed_(std::make_shared<bool>(false)), logger_(logger)
    {
        url_.host = host;
        url_.service = service;
        url_.protocol = (ssl ? "https" : "http");
        resolve(url_.host, url_.service.empty() ? url_.protocol : url_.service);
    }
    
    Resolver::Resolver(asio::io_context& ctx, std::vector<asio::ip::tcp::endpoint> endpoints, const bool ssl,
                       std::shared_ptr<dht::Logger> logger)
        : resolver_(ctx), destroyed_(std::make_shared<bool>(false)), logger_(logger)
    {
        url_.protocol = (ssl ? "https" : "http");
        endpoints_ = std::move(endpoints);
        completed_ = true;
    }
    
    Resolver::~Resolver()
    {
        decltype(cbs_) cbs;
        {
            std::lock_guard<std::mutex> lock(mutex_);
            cbs = std::move(cbs_);
        }
        while (not cbs.empty()){
            auto cb = cbs.front();
            if (cb)
                cb(asio::error::operation_aborted, {});
            cbs.pop();
        }
        *destroyed_ = true;
    }
    
    inline
    std::vector<asio::ip::tcp::endpoint>
    filter(const std::vector<asio::ip::tcp::endpoint>& epts, sa_family_t family)
    {
        if (family == AF_UNSPEC)
            return epts;
        std::vector<asio::ip::tcp::endpoint> ret;
        for (const auto& ep : epts) {
            if (family == AF_INET && ep.address().is_v4())
                ret.emplace_back(ep);
            else if (family == AF_INET6 && ep.address().is_v6())
                ret.emplace_back(ep);
        }
        return ret;
    }
    
    void
    Resolver::add_callback(ResolverCb cb, sa_family_t family)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (!completed_)
            cbs_.emplace(family == AF_UNSPEC ? std::move(cb) : [cb, family](const asio::error_code& ec, const std::vector<asio::ip::tcp::endpoint>& endpoints){
                if (ec)
                    cb(ec, endpoints);
                else
                    cb(ec, filter(endpoints, family));
            });
        else
            cb(ec_, family == AF_UNSPEC ? endpoints_ : filter(endpoints_, family));
    }
    
    void
    Resolver::resolve(const std::string& host, const std::string& service)
    {
        asio::ip::tcp::resolver::query query_(host, service);
        resolver_.async_resolve(query_, [this, host, service, destroyed = destroyed_]
            (const asio::error_code& ec, asio::ip::tcp::resolver::results_type endpoints)
        {
            if (ec == asio::error::operation_aborted or *destroyed)
                return;
            if (logger_) {
                if (ec)
                    logger_->e("[http:client] [resolver] error for %s:%s: %s",
                               host.c_str(), service.c_str(), ec.message().c_str());
            }
            decltype(cbs_) cbs;
            {
                std::lock_guard<std::mutex> lock(mutex_);
                ec_ = ec;
                endpoints_ = std::vector<asio::ip::tcp::endpoint>{endpoints.begin(), endpoints.end()};
                completed_ = true;
                cbs = std::move(cbs_);
            }
            while (not cbs.empty()){
                auto cb = cbs.front();
                if (cb)
                    cb(ec, endpoints_);
                cbs.pop();
            }
        });
    }
    
    // Request
    
    std::atomic_uint Request::ids_ {1};
    
    
    Request::Request(asio::io_context& ctx, const std::string& url, const Json::Value& json, OnJsonCb jsoncb,
                     std::shared_ptr<dht::Logger> logger)
        : logger_(std::move(logger)), id_(Request::ids_++), ctx_(ctx),
          resolver_(std::make_shared<Resolver>(ctx, url, logger))
    {
        init_default_headers();
        set_header_field(restinio::http_field_t::content_type, HTTP_HEADER_CONTENT_TYPE_JSON);
        set_header_field(restinio::http_field_t::accept, HTTP_HEADER_CONTENT_TYPE_JSON);
        Json::StreamWriterBuilder wbuilder;
        set_method(restinio::http_method_post());
        set_body(Json::writeString(wbuilder, json));
        add_on_done_callback([this, jsoncb](const Response& response){
            Json::Value json;
            if (response.status_code != 0) {
                std::string err;
                Json::CharReaderBuilder rbuilder;
                auto reader = std::unique_ptr<Json::CharReader>(rbuilder.newCharReader());
                if (!reader->parse(response.body.data(), response.body.data() + response.body.size(), &json, &err) and logger_)
                    logger_->e("[http:request:%i] can't parse response to json", id_, err.c_str());
            }
            if (jsoncb)
                jsoncb(std::move(json), response);
        });
    }
    
    Request::Request(asio::io_context& ctx, const std::string& url, OnJsonCb jsoncb, std::shared_ptr<dht::Logger> logger)
        : logger_(std::move(logger)), id_(Request::ids_++), ctx_(ctx),
          resolver_(std::make_shared<Resolver>(ctx, url, logger))
    {
        init_default_headers();
        set_header_field(restinio::http_field_t::accept, HTTP_HEADER_CONTENT_TYPE_JSON);
        Json::StreamWriterBuilder wbuilder;
        set_method(restinio::http_method_get());
        add_on_done_callback([this, jsoncb](const Response& response) {
            Json::Value json;
            if (response.status_code != 0) {
                std::string err;
                Json::CharReaderBuilder rbuilder;
                auto reader = std::unique_ptr<Json::CharReader>(rbuilder.newCharReader());
                if (!reader->parse(response.body.data(), response.body.data() + response.body.size(), &json, &err) and logger_)
                    logger_->e("[http:request:%i] can't parse response to json", id_, err.c_str());
            }
            if (jsoncb)
                jsoncb(std::move(json), response);
        });
    }
    
    Request::Request(asio::io_context& ctx, const std::string& url, std::shared_ptr<dht::Logger> logger)
        : logger_(logger), id_(Request::ids_++), ctx_(ctx),
          resolver_(std::make_shared<Resolver>(ctx, url, logger))
    {
        init_default_headers();
    }
    
    Request::Request(asio::io_context& ctx, const std::string& url, OnDoneCb onDone, std::shared_ptr<dht::Logger> logger)
        : logger_(logger), id_(Request::ids_++), ctx_(ctx), resolver_(std::make_shared<Resolver>(ctx, url, logger))
    {
        init_default_headers();
        add_on_done_callback(std::move(onDone));
    }
    
    Request::Request(asio::io_context& ctx, const std::string& host, const std::string& service,
                     const bool ssl, std::shared_ptr<dht::Logger> logger)
        : logger_(logger), id_(Request::ids_++), ctx_(ctx),
          resolver_(std::make_shared<Resolver>(ctx, host, service, ssl, logger))
    {
        init_default_headers();
    }
    
    Request::Request(asio::io_context& ctx, std::shared_ptr<Resolver> resolver, sa_family_t family)
        : logger_(resolver->getLogger()), id_(Request::ids_++), ctx_(ctx), family_(family), resolver_(resolver)
    {
        init_default_headers();
    }
    
    Request::Request(asio::io_context& ctx, std::vector<asio::ip::tcp::endpoint>&& endpoints, const bool ssl,
                     std::shared_ptr<dht::Logger> logger)
        : logger_(logger), id_(Request::ids_++), ctx_(ctx),
          resolver_(std::make_shared<Resolver>(ctx, std::move(endpoints), ssl, logger))
    {
        init_default_headers();
    }
    
    Request::Request(asio::io_context& ctx, std::shared_ptr<Resolver> resolver, const std::string& target, sa_family_t family)
        : logger_(resolver->getLogger()), id_(Request::ids_++), ctx_(ctx), family_(family), resolver_(resolver)
    {
        set_header_field(restinio::http_field_t::host, get_url().host + ":" + get_url().service);
        set_target(Url(target).target);
    }
    
    Request::~Request()
    {
        resolver_.reset();
        terminate(asio::error::connection_aborted);
    }
    
    void
    Request::init_default_headers()
    {
        const auto& url = resolver_->get_url();
        set_header_field(restinio::http_field_t::user_agent, "Mozilla/5.0");
        set_header_field(restinio::http_field_t::accept, "text/html");
        set_target(url.target);
    }
    
    void
    Request::cancel()
    {
        if (auto c = conn_)
            c->close();
    }
    
    void
    Request::set_connection(std::shared_ptr<Connection> connection) {
        conn_ = std::move(connection);
    }
    
    std::shared_ptr<Connection>
    Request::get_connection() const {
        return conn_;
    }
    
    void
    Request::set_certificate_authority(std::shared_ptr<dht::crypto::Certificate> certificate) {
        server_ca_ = certificate;
    }
    
    void
    Request::set_identity(const dht::crypto::Identity& identity) {
        client_identity_ = identity;
    }
    
    void
    Request::set_logger(std::shared_ptr<dht::Logger> logger) {
        logger_ = logger;
    }
    
    void
    Request::set_header(restinio::http_request_header_t header)
    {
        header_ = header;
    }
    
    void
    Request::set_method(restinio::http_method_id_t method) {
        header_.method(method);
    }
    
    void
    Request::set_target(std::string target) {
        header_.request_target(target.empty() ? "/" : std::move(target));
    }
    
    void
    Request::set_header_field(restinio::http_field_t field, std::string value) {
        headers_[field] = std::move(value);
    }
    
    void
    Request::set_connection_type(restinio::http_connection_header_t connection) {
        connection_type_ = connection;
    }
    
    void
    Request::set_body(std::string body) {
        body_ = std::move(body);
    }
    
    void
    Request::set_auth(const std::string& username, const std::string& password)
    {
        std::vector<uint8_t> creds;
        creds.reserve(username.size() + password.size() + 1);
        creds.insert(creds.end(), username.begin(), username.end());
        creds.emplace_back(':');
        creds.insert(creds.end(), password.begin(), password.end());
        set_header_field(restinio::http_field_t::authorization, "Basic " + base64_encode(creds));
    }
    
    void
    Request::build()
    {
        std::stringstream request;
        bool append_body = !body_.empty();
    
        // first header
        request << header_.method().c_str() << " " << header_.request_target() << " " <<
                   "HTTP/" << header_.http_major() << "." << header_.http_minor() << "\r\n";
    
        // other headers
        for (auto header: headers_){
            request << restinio::field_to_string(header.first) << ": " << header.second << "\r\n";
            if (header.first == restinio::http_field_t::expect and header.second == "100-continue")
                append_body = false;
        }
    
        // last connection header
        const char* conn_str = nullptr;
        switch (connection_type_){
        case restinio::http_connection_header_t::keep_alive:
            conn_str = "keep-alive";
            break;
        case restinio::http_connection_header_t::upgrade:
            if (logger_)
                logger_->e("Unsupported connection type 'upgrade', fallback to 'close'");
        // fallthrough
        case restinio::http_connection_header_t::close:
            conn_str = "close"; // default
            break;
        }
        if (conn_str)
            request << "Connection: " << conn_str << "\r\n";
    
        // body & content-length
        if (append_body) {
            request << "Content-Length: " << body_.size() << "\r\n\r\n"
                    << body_;
        } else
            request << "\r\n";
        request_ = request.str();
    }
    
    void
    Request::add_on_status_callback(OnStatusCb cb) {
        cbs_.on_status = std::move(cb);
    }
    
    void
    Request::add_on_body_callback(OnDataCb cb) {
        cbs_.on_body = std::move(cb);
    }
    
    void
    Request::add_on_state_change_callback(OnStateChangeCb cb) {
        cbs_.on_state_change = std::move(cb);
    }
    
    void
    Request::add_on_done_callback(OnDoneCb cb) {
        add_on_state_change_callback([onDone=std::move(cb)](State state, const Response& response){
            if (state == Request::State::DONE)
                onDone(response);
        });
    }
    
    void
    Request::notify_state_change(State state) {
        state_ = state;
        if (cbs_.on_state_change)
            cbs_.on_state_change(state, response_);
    }
    
    void
    Request::init_parser()
    {
        response_.request = shared_from_this();
    
        if (!parser_)
            parser_ = std::make_unique<http_parser>();
        http_parser_init(parser_.get(), HTTP_RESPONSE);
        parser_->data = static_cast<void*>(this);
    
        if (!parser_s_)
            parser_s_ = std::make_unique<http_parser_settings>();
        http_parser_settings_init(parser_s_.get());
    
        cbs_.on_status = [this, statusCb = std::move(cbs_.on_status)](unsigned int status_code){
            response_.status_code = status_code;
            if (statusCb)
                statusCb(status_code);
        };
        auto header_field = std::make_shared<std::string>();
        cbs_.on_header_field = [header_field](const char* at, size_t length) {
            *header_field = std::string(at, length);
        };
        cbs_.on_header_value = [this, header_field](const char* at, size_t length) {
            response_.headers[*header_field] = std::string(at, length);
        };
    
        // http_parser raw c callback (note: no context can be passed into them)
        parser_s_->on_status = [](http_parser* parser, const char* /*at*/, size_t /*length*/) -> int {
            static_cast<Request*>(parser->data)->cbs_.on_status(parser->status_code);
            return 0;
        };
        parser_s_->on_header_field = [](http_parser* parser, const char* at, size_t length) -> int {
            static_cast<Request*>(parser->data)->cbs_.on_header_field(at, length);
            return 0;
        };
        parser_s_->on_header_value = [](http_parser* parser, const char* at, size_t length) -> int {
            static_cast<Request*>(parser->data)->cbs_.on_header_value(at, length);
            return 0;
        };
        parser_s_->on_body = [](http_parser* parser, const char* at, size_t length) -> int {
            static_cast<Request*>(parser->data)->onBody(at, length);
            return 0;
        };
        parser_s_->on_headers_complete = [](http_parser* parser) -> int {
            static_cast<Request*>(parser->data)->onHeadersComplete();
            return 0;
        };
        parser_s_->on_message_complete = [](http_parser* parser) -> int {
            static_cast<Request*>(parser->data)->onComplete();
            return 0;
        };
    }
    
    void
    Request::connect(std::vector<asio::ip::tcp::endpoint>&& endpoints, HandlerCb cb)
    {
        if (endpoints.empty()){
            if (logger_)
                logger_->e("[http:request:%i] connect: no endpoints provided", id_);
            if (cb)
                cb(asio::error::connection_aborted);
            return;
        }
        if (logger_){
            std::string eps = "";
            for (const auto& endpoint : endpoints)
                eps.append(endpoint.address().to_string() + ":" + std::to_string(endpoint.port()) + " ");
            logger_->d("[http:request:%i] connect begin: %s", id_, eps.c_str());
        }
        bool isHttps = get_url().protocol == "https";
        if (isHttps) {
            if (server_ca_ or client_identity_.first)
                conn_ = std::make_shared<Connection>(ctx_, server_ca_, client_identity_, logger_);
            else
                conn_ = std::make_shared<Connection>(ctx_, true/*ssl*/, logger_);
            conn_->set_ssl_verification(get_url().host, asio::ssl::verify_peer | asio::ssl::verify_fail_if_no_peer_cert);
        }
        else
            conn_ = std::make_shared<Connection>(ctx_, false/*ssl*/, logger_);
    
        // try to connect to any until one works
        std::weak_ptr<Request> wthis = shared_from_this();
        conn_->async_connect(std::move(endpoints), [wthis, cb, isHttps]
                            (const asio::error_code& ec, const asio::ip::tcp::endpoint& endpoint){
            auto sthis = wthis.lock();
            if (not sthis)
                return;
            auto& this_ = *sthis;
            std::lock_guard<std::mutex> lock(this_.mutex_);
            if (ec == asio::error::operation_aborted){
                this_.terminate(ec);
                return;
            }
            else if (ec) {
                if (this_.logger_)
                    this_.logger_->e("[http:request:%i] connect failed with all endpoints: %s", this_.id_, ec.message().c_str());
            } else {
                const auto& url = this_.get_url();
                auto port = endpoint.port();
                if ((!isHttps && port == (in_port_t)80)
                 || (isHttps && port == (in_port_t)443))
                    this_.set_header_field(restinio::http_field_t::host, url.host);
                else
                    this_.set_header_field(restinio::http_field_t::host, url.host + ":" + std::to_string(port));
    
                if (isHttps) {
                    if (this_.conn_ and this_.conn_->is_open() and this_.conn_->is_ssl()) {
                        this_.conn_->async_handshake([id = this_.id_, cb, logger = this_.logger_](const asio::error_code& ec){
                            if (ec == asio::error::operation_aborted)
                                return;
                            if (ec and logger)
                                logger->e("[http:request:%i] handshake error: %s", id, ec.message().c_str());
                            //else if (logger)
                            //    logger->d("[http:request:%i] handshake success", id);
                            if (cb)
                                cb(ec);
                        });
                    }
                    else if (cb)
                        cb(asio::error::operation_aborted);
                    return;
                }
            }
            if (cb)
                cb(ec);
        });
    }
    
    void
    Request::send()
    {
        notify_state_change(State::CREATED);
    
        std::weak_ptr<Request> wthis = shared_from_this();
        resolver_->add_callback([wthis](const asio::error_code& ec,
                                       std::vector<asio::ip::tcp::endpoint> endpoints) {
            if (auto sthis = wthis.lock()) {
                auto& this_ = *sthis;
                std::lock_guard<std::mutex> lock(this_.mutex_);
                if (ec){
                    if (this_.logger_)
                        this_.logger_->e("[http:request:%i] resolve error: %s", this_.id_, ec.message().c_str());
                    this_.terminate(asio::error::connection_aborted);
                }
                else if (!this_.conn_ or !this_.conn_->is_open()) {
                    this_.connect(std::move(endpoints), [wthis](const asio::error_code &ec) {
                        if (auto sthis = wthis.lock()) {
                            if (ec)
                                sthis->terminate(asio::error::not_connected);
                            else
                                sthis->post();
                        }
                    });
                }
                else
                    this_.post();
            }
        }, family_);
    }
    
    void
    Request::post()
    {
        if (!conn_ or !conn_->is_open()){
            terminate(asio::error::not_connected);
            return;
        }
        build();
        init_parser();
    
        if (logger_)
            logger_->d("[http:request:%i] sending %zu bytes", id_, request_.size());
    
        // write the request to buffer
        std::ostream request_stream(&conn_->input());
        request_stream << request_;
    
        // send the request
        notify_state_change(State::SENDING);
    
        std::weak_ptr<Request> wthis = shared_from_this();
        conn_->async_write([wthis](const asio::error_code& ec, size_t) {
            if (auto sthis = wthis.lock())
                sthis->handle_request(ec);
        });
    }
    
    void
    Request::terminate(const asio::error_code& ec)
    {
        if (finishing_.exchange(true))
            return;
    
        response_.aborted = ec == asio::error::operation_aborted;
        if (ec == asio::error::basic_errors::broken_pipe)
            response_.status_code = 0U; // Avoid to give a successful answer (happen with a broken pipe, takes the last status)
    
        if (logger_) {
            if (ec and ec != asio::error::eof and !response_.aborted)
                logger_->e("[http:request:%i] end with error: %s", id_, ec.message().c_str());
            else
                logger_->d("[http:request:%i] done with status code %u", id_, response_.status_code);
        }
    
        if (!parser_ or !http_should_keep_alive(parser_.get()))
            if (auto c = conn_)
                c->close();
        notify_state_change(State::DONE);
    }
    
    void
    Request::handle_request(const asio::error_code& ec)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (ec and ec != asio::error::eof){
            terminate(ec);
            return;
        }
        if (!conn_->is_open()){
            terminate(asio::error::not_connected);
            return;
        }
        // if (logger_)
        //    logger_->d("[http:request:%i] send success", id_);
        // read response
        notify_state_change(State::RECEIVING);
    
        std::weak_ptr<Request> wthis = shared_from_this();
        conn_->async_read_until(HTTP_HEADER_DELIM, [wthis](const asio::error_code& ec, size_t n_bytes){
            if (auto sthis = wthis.lock())
                sthis->handle_response(ec, n_bytes);
        });
    }
    
    void
    Request::handle_response(const asio::error_code& ec, size_t /* n_bytes */)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (ec && ec != asio::error::eof){
            terminate(ec);
            return;
        }
        auto request = (ec == asio::error::eof) ? std::string{} : conn_->read_bytes();
        size_t ret = http_parser_execute(parser_.get(), parser_s_.get(), request.c_str(), request.size());
        if (ret != request.size()) {
            if (logger_)
                logger_->e("Error parsing HTTP: %zu %s %s", ret,
                    http_errno_name(HTTP_PARSER_ERRNO(parser_)),
                    http_errno_description(HTTP_PARSER_ERRNO(parser_)));
            terminate(asio::error::basic_errors::broken_pipe);
            return;
        }
    
        if (state_ != State::DONE and parser_ and not http_body_is_final(parser_.get())) {
            auto toRead = parser_->content_length ? std::min<uint64_t>(parser_->content_length, 64 * 1024) : 64 * 1024;
            std::weak_ptr<Request> wthis = shared_from_this();
            conn_->async_read_some(toRead, [wthis](const asio::error_code& ec, size_t bytes){
                if (auto sthis = wthis.lock())
                    sthis->handle_response(ec, bytes);
            });
        }
    }
    
    void
    Request::onBody(const char* at, size_t length)
    {
        if (cbs_.on_body)
            cbs_.on_body(at, length);
        else
            response_.body.insert(response_.body.end(), at, at+length);
    }
    
    void
    Request::onComplete() {
        terminate(asio::error::eof);
    }
    
    void
    Request::onHeadersComplete() {
        notify_state_change(State::HEADER_RECEIVED);
    
        if (response_.status_code == restinio::status_code::moved_permanently.raw_code() or
            response_.status_code == restinio::status_code::found.raw_code())
        {
            auto location_it = response_.headers.find(restinio::field_to_string(restinio::http_field_t::location));
            if (location_it == response_.headers.end()){
                if (logger_)
                    logger_->e("[http:client] [request:%i] got redirect without location", id_);
                terminate(asio::error::connection_aborted);
            }
    
            if (follow_redirect and num_redirect < MAX_REDIRECTS) {
                auto newUrl = getRelativePath(get_url(), location_it->second);
                if (logger_)
                    logger_->w("[http:client] [request:%i] redirect to %s", id_, newUrl.c_str());
                auto next = std::make_shared<Request>(ctx_, newUrl, logger_);
                next->set_method(header_.method());
                next->headers_ = std::move(headers_);
                next->body_ = std::move(body_);
                next->cbs_ = std::move(cbs_);
                next->num_redirect = num_redirect + 1;
                next_ = next;
                next->prev_ = shared_from_this();
                next->send();
            } else {
                if (logger_)
                    logger_->e("[http:client] [request:%i] got redirect without location", id_);
                terminate(asio::error::connection_aborted);
            }
        } else {
            auto expect_it = headers_.find(restinio::http_field_t::expect);
            if (expect_it != headers_.end() and (expect_it->second == "100-continue") and response_.status_code != 200){
                notify_state_change(State::SENDING);
                request_.append(body_);
                std::ostream request_stream(&conn_->input());
                request_stream << body_ << "\r\n";
                std::weak_ptr<Request> wthis = shared_from_this();
                conn_->async_write([wthis](const asio::error_code& ec, size_t) {
                    if (auto sthis = wthis.lock())
                        sthis->handle_request(ec);
                });
            }
        }
    }
    
    bool startsWith(const std::string& haystack, const std::string& needle) {
        return needle.length() <= haystack.length()
            && std::equal(needle.begin(), needle.end(), haystack.begin());
    }
    
    std::string
    Request::getRelativePath(const Url& origin, const std::string& path)
    {
        if (startsWith(path, HTTP_PROTOCOL)
        || startsWith(path, HTTPS_PROTOCOL)
        || startsWith(path, ORIGIN_PROTOCOL)) {
            // Absolute path
            return path;
        }
        Url newPath = origin;
        if (not path.empty() and path[0] == '/') {
            newPath.target = path;
        } else {
            if (newPath.target.empty())
                newPath.target.push_back('/');
            newPath.target += path;
        }
        return newPath.toString();
    }
    
    const Response&
    Request::await()
    {
        std::mutex mtx;
        std::unique_lock<std::mutex> lock(mtx);
        std::condition_variable cv;
        bool ok {false};
        add_on_done_callback([&](const Response&){
            std::lock_guard<std::mutex> lk(mtx);
            ok = true;
            cv.notify_all();
        });
        cv.wait(lock, [&]{ return ok; });
        return response_;
    }
    
    } // namespace http
    } // namespace dht