static void free_connections(struct ev_loop *loop)
{
    struct cork_dllist_item *curr;
    for (curr = cork_dllist_start(&connections);
         !cork_dllist_is_end(&connections, curr);
         curr = curr->next) {
        struct server *server = cork_container_of(curr, struct server, entries);
        struct remote *remote = server->remote;
        close_and_free_server(loop, server);
        close_and_free_remote(loop, remote);
    }
}

static void server_timeout_cb(EV_P_ ev_timer *watcher, int revents)
{
    struct server_ctx *server_ctx = (struct server_ctx *) (((void*)watcher)
                                    - sizeof(ev_io));
    struct server *server = server_ctx->server;
    struct remote *remote = server->remote;

    LOGE("TCP connection timeout");

    close_and_free_remote(EV_A_ remote);
    close_and_free_server(EV_A_ server);
}

static void
remote_timeout_cb(EV_P_ ev_timer *watcher, int revents)
{
    remote_ctx_t *remote_ctx = (remote_ctx_t *)(((void *)watcher)
                                                - sizeof(ev_io));
    remote_t *remote = remote_ctx->remote;
    server_t *server = remote->server;

    ev_timer_stop(EV_A_ watcher);

    close_and_free_remote(EV_A_ remote);
    close_and_free_server(EV_A_ server);
}

static void remote_timeout_cb(EV_P_ ev_timer *watcher, int revents)
{
    struct remote_ctx *remote_ctx = (struct remote_ctx *)(((void *)watcher)
                                                          - sizeof(ev_io));
    struct remote *remote = remote_ctx->remote;
    struct server *server = remote->server;

    if (verbose) {
        LOGI("TCP connection timeout");
    }

    close_and_free_remote(EV_A_ remote);
    close_and_free_server(EV_A_ server);
}

static void
remote_timeout_cb(EV_P_ ev_timer *watcher, int revents)
{
    remote_ctx_t *remote_ctx
        = cork_container_of(watcher, remote_ctx_t, watcher);

    remote_t *remote = remote_ctx->remote;
    server_t *server = remote->server;

    ev_timer_stop(EV_A_ watcher);

    close_and_free_remote(EV_A_ remote);
    close_and_free_server(EV_A_ server);
}

static void
server_send_cb(EV_P_ ev_io *w, int revents)
{
    server_ctx_t *server_send_ctx = (server_ctx_t *)w;
    server_t *server              = server_send_ctx->server;
    remote_t *remote              = server->remote;
    if (server->buf->len == 0) {
        // close and free
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else {
        // has data to send
        ssize_t s = send(server->fd, server->buf->array + server->buf->idx,
                         server->buf->len, 0);
        if (s == -1) {
            if (errno != EAGAIN && errno != EWOULDBLOCK) {
                ERROR("send");
                close_and_free_remote(EV_A_ remote);
                close_and_free_server(EV_A_ server);
            }
            return;
        } else if (s < server->buf->len) {
            // partly sent, move memory, wait for the next time to send
            server->buf->len -= s;
            server->buf->idx += s;
            return;
        } else {
            // all sent out, wait for reading
            server->buf->len = 0;
            server->buf->idx = 0;
            ev_io_stop(EV_A_ & server_send_ctx->io);
            ev_io_start(EV_A_ & remote->recv_ctx->io);
        }
    }
}

static void remote_timeout_cb(EV_P_ ev_timer *watcher, int revents) {
    struct remote_ctx *remote_ctx = (struct remote_ctx *) (((void*)watcher)
            - sizeof(ev_io));
    struct remote *remote = remote_ctx->remote;
    struct server *server = remote->server;

    LOGD("remote timeout");

    ev_timer_stop(EV_A_ watcher);

    if (server == NULL) {
        close_and_free_remote(EV_A_ remote);
        return;
    }
    close_and_free_remote(EV_A_ remote);
    close_and_free_server(EV_A_ server);
}

static void
delayed_connect_cb(EV_P_ ev_timer *watcher, int revents)
{
    server_t *server = cork_container_of(watcher, server_t,
                                         delayed_connect_watcher);
    remote_t *remote = server->remote;

    int r = connect(remote->fd, remote->addr,
                    get_sockaddr_len(remote->addr));

    if (r == -1 && errno != CONNECT_IN_PROGRESS) {
        ERROR("connect");
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else {
        // listen to remote connected event
        ev_io_start(EV_A_ & remote->send_ctx->io);
        ev_timer_start(EV_A_ & remote->send_ctx->watcher);
    }
}

static void remote_recv_cb(EV_P_ ev_io *w, int revents)
{
    struct remote_ctx *remote_recv_ctx = (struct remote_ctx *)w;
    struct remote *remote = remote_recv_ctx->remote;
    struct server *server = remote->server;

    ev_timer_again(EV_A_ & remote->recv_ctx->watcher);

    ssize_t r = recv(remote->fd, server->buf, BUF_SIZE, 0);

    if (r == 0) {
        // connection closed
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else if (r < 0) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // no data
            // continue to wait for recv
            return;
        } else {
            ERROR("remote_recv_cb_recv");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    }

    if (!remote->direct) {
        server->buf = ss_decrypt(BUF_SIZE, server->buf, &r, server->d_ctx);
        if (server->buf == NULL) {
            LOGE("invalid password or cipher");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    }

    int s = send(server->fd, server->buf, r, 0);

    if (s == -1) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // no data, wait for send
            server->buf_len = r;
            server->buf_idx = 0;
            ev_io_stop(EV_A_ & remote_recv_ctx->io);
            ev_io_start(EV_A_ & server->send_ctx->io);
            return;
        } else {
            ERROR("remote_recv_cb_send");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    } else if (s < r) {
        server->buf_len = r - s;
        server->buf_idx = s;
        ev_io_stop(EV_A_ & remote_recv_ctx->io);
        ev_io_start(EV_A_ & server->send_ctx->io);
        return;
    }
}

static void server_recv_cb(EV_P_ ev_io *w, int revents)
{
    struct server_ctx *server_recv_ctx = (struct server_ctx *)w;
    struct server *server = server_recv_ctx->server;
    struct remote *remote = server->remote;
    char *buf;

    if (remote == NULL) {
        buf = server->buf;
    } else {
        buf = remote->buf;
    }

    ssize_t r = recv(server->fd, buf, BUF_SIZE, 0);

    if (r == 0) {
        // connection closed
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else if (r < 0) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // no data
            // continue to wait for recv
            return;
        } else {
            ERROR("server_recv_cb_recv");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    }

    while (1) {
        // local socks5 server
        if (server->stage == 5) {
            if (remote == NULL) {
                LOGE("invalid remote.");
                close_and_free_server(EV_A_ server);
                return;
            }

            // insert shadowsocks header
            if (!remote->direct) {
                remote->buf = ss_encrypt(BUF_SIZE, remote->buf, &r,
                                         server->e_ctx);

                if (remote->buf == NULL) {
                    LOGE("invalid password or cipher");
                    close_and_free_remote(EV_A_ remote);
                    close_and_free_server(EV_A_ server);
                    return;
                }
            }

            if (!remote->send_ctx->connected) {
                remote->buf_idx = 0;
                remote->buf_len = r;

                if (!fast_open || remote->direct) {
                    // connecting, wait until connected
                    connect(remote->fd, remote->addr_info->ai_addr,
                            remote->addr_info->ai_addrlen);

                    // wait on remote connected event
                    ev_io_stop(EV_A_ & server_recv_ctx->io);
                    ev_io_start(EV_A_ & remote->send_ctx->io);
                    ev_timer_start(EV_A_ & remote->send_ctx->watcher);
                } else {
#ifdef TCP_FASTOPEN
                    int s = sendto(remote->fd, remote->buf, r, MSG_FASTOPEN,
                                   remote->addr_info->ai_addr,
                                   remote->addr_info->ai_addrlen);
                    if (s == -1) {
                        if (errno == EINPROGRESS) {
                            // in progress, wait until connected
                            remote->buf_idx = 0;
                            remote->buf_len = r;
                            ev_io_stop(EV_A_ & server_recv_ctx->io);
                            ev_io_start(EV_A_ & remote->send_ctx->io);
                            return;
                        } else {
                            ERROR("sendto");
                            if (errno == ENOTCONN) {
                                LOGE(
                                    "fast open is not supported on this platform");
                                // just turn it off
                                fast_open = 0;
                            }
                            close_and_free_remote(EV_A_ remote);
                            close_and_free_server(EV_A_ server);
                            return;
                        }
                    } else if (s < r) {
                        remote->buf_len = r - s;
                        remote->buf_idx = s;
                    }

                    // Just connected
                    remote->send_ctx->connected = 1;
//.........这里部分代码省略.........

static void
accept_cb(EV_P_ ev_io *w, int revents)
{
    struct listen_ctx *listener = (struct listen_ctx *)w;
    int serverfd                = accept(listener->fd, NULL, NULL);
    if (serverfd == -1) {
        ERROR("accept");
        return;
    }
    setnonblocking(serverfd);
    int opt = 1;
    setsockopt(serverfd, SOL_TCP, TCP_NODELAY, &opt, sizeof(opt));
#ifdef SO_NOSIGPIPE
    setsockopt(serverfd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
#endif

    int index                    = rand() % listener->remote_num;
    struct sockaddr *remote_addr = listener->remote_addr[index];

    int remotefd = socket(remote_addr->sa_family, SOCK_STREAM, IPPROTO_TCP);
    if (remotefd == -1) {
        ERROR("socket");
        return;
    }

#ifdef ANDROID
    if (vpn) {
        int not_protect = 0;
        if (remote_addr->sa_family == AF_INET) {
            struct sockaddr_in *s = (struct sockaddr_in *)remote_addr;
            if (s->sin_addr.s_addr == inet_addr("127.0.0.1"))
                not_protect = 1;
        }
        if (!not_protect) {
            if (protect_socket(remotefd) == -1) {
                ERROR("protect_socket");
                close(remotefd);
                return;
            }
        }
    }
#endif

    setsockopt(remotefd, SOL_TCP, TCP_NODELAY, &opt, sizeof(opt));
#ifdef SO_NOSIGPIPE
    setsockopt(remotefd, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
#endif

    if (listener->mptcp == 1) {
        int err = setsockopt(remotefd, SOL_TCP, MPTCP_ENABLED, &opt, sizeof(opt));
        if (err == -1) {
            ERROR("failed to enable multipath TCP");
        }
    }

    // Setup
    setnonblocking(remotefd);
#ifdef SET_INTERFACE
    if (listener->iface) {
        if (setinterface(remotefd, listener->iface) == -1)
            ERROR("setinterface");
    }
#endif

    server_t *server = new_server(serverfd, listener->method);
    remote_t *remote = new_remote(remotefd, listener->timeout);
    server->destaddr = listener->tunnel_addr;
    server->remote   = remote;
    remote->server   = server;

    int r = connect(remotefd, remote_addr, get_sockaddr_len(remote_addr));

    if (r == -1 && errno != CONNECT_IN_PROGRESS) {
        ERROR("connect");
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    }

    // listen to remote connected event
    ev_io_start(EV_A_ & remote->send_ctx->io);
    ev_timer_start(EV_A_ & remote->send_ctx->watcher);
}

static void remote_send_cb(EV_P_ ev_io *w, int revents)
{
    struct remote_ctx *remote_send_ctx = (struct remote_ctx *)w;
    struct remote *remote = remote_send_ctx->remote;
    struct server *server = remote->server;

    if (server == NULL) {
        LOGE("invalid server");
        close_and_free_remote(EV_A_ remote);
        return;
    }

    if (!remote_send_ctx->connected) {

        struct sockaddr_storage addr;
        socklen_t len = sizeof addr;
        memset(&addr, 0, len);
        int r = getpeername(remote->fd, (struct sockaddr *)&addr, &len);
        if (r == 0) {
            if (verbose) {
                LOGI("remote connected");
            }
            remote_send_ctx->connected = 1;

            if (remote->buf_len == 0) {
                server->stage = 5;
                ev_io_stop(EV_A_ & remote_send_ctx->io);
                ev_io_start(EV_A_ & server->recv_ctx->io);
                ev_io_start(EV_A_ & remote->recv_ctx->io);
                return;
            }

        } else {
            ERROR("getpeername");
            // not connected
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    }

    if (remote->buf_len == 0) {
        // close and free
        if (verbose) {
            LOGI("remote_send close the connection");
        }
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else {
        // has data to send
        ssize_t s = send(remote->fd, remote->buf + remote->buf_idx,
                         remote->buf_len, 0);
        if (s == -1) {
            if (errno != EAGAIN && errno != EWOULDBLOCK) {
                ERROR("remote_send_send");
                // close and free
                close_and_free_remote(EV_A_ remote);
                close_and_free_server(EV_A_ server);
            }
            return;
        } else if (s < remote->buf_len) {
            // partly sent, move memory, wait for the next time to send
            remote->buf_len -= s;
            remote->buf_idx += s;
            return;
        } else {
            // all sent out, wait for reading
            remote->buf_len = 0;
            remote->buf_idx = 0;
            ev_io_stop(EV_A_ & remote_send_ctx->io);
            if (server != NULL) {
                ev_io_start(EV_A_ & server->recv_ctx->io);
                if (server->stage == 4) {
                    server->stage = 5;
                    ev_io_start(EV_A_ & remote->recv_ctx->io);
                }
            } else {
                LOGE("invalid server");
                close_and_free_remote(EV_A_ remote);
                close_and_free_server(EV_A_ server);
            }
            return;
        }
    }
}

static void remote_recv_cb(EV_P_ ev_io *w, int revents)
{
    remote_ctx_t *remote_recv_ctx = (remote_ctx_t *)w;
    remote_t *remote              = remote_recv_ctx->remote;
    server_t *server              = remote->server;

    ev_timer_again(EV_A_ & remote->recv_ctx->watcher);

#ifdef ANDROID
    stat_update_cb(loop);
#endif

    ssize_t r = recv(remote->fd, server->buf->array, BUF_SIZE, 0);

    if (r == 0) {
        // connection closed
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else if (r < 0) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // no data
            // continue to wait for recv
            return;
        } else {
            ERROR("remote_recv_cb_recv");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    }

    server->buf->len = r;

    if (!remote->direct) {
#ifdef ANDROID
        rx += server->buf->len;
#endif
        if ( r == 0 )
            return;
        // SSR beg
        if (server->obfs_plugin) {
            obfs_class *obfs_plugin = server->obfs_plugin;
            if (obfs_plugin->client_decode) {
                int needsendback;
                server->buf->len = obfs_plugin->client_decode(server->obfs, &server->buf->array, server->buf->len, &server->buf->capacity, &needsendback);
                if (server->buf->len < 0) {
                    LOGE("client_decode");
                    close_and_free_remote(EV_A_ remote);
                    close_and_free_server(EV_A_ server);
                    return;
                }
            }
        }
        int err = ss_decrypt(server->buf, server->d_ctx);
        if (err) {
            LOGE("remote invalid password or cipher");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
        if (server->protocol_plugin) {
            obfs_class *protocol_plugin = server->protocol_plugin;
            if (protocol_plugin->client_post_decrypt) {
                server->buf->len = protocol_plugin->client_post_decrypt(server->protocol, &server->buf->array, server->buf->len, &server->buf->capacity);
                if (server->buf->len < 0) {
                    LOGE("client_post_decrypt");
                    close_and_free_remote(EV_A_ remote);
                    close_and_free_server(EV_A_ server);
                    return;
                }
                if ( server->buf->len == 0 )
                    return;
            }
        }
        // SSR end
    }

    int s = send(server->fd, server->buf->array, server->buf->len, 0);

    if (s == -1) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // no data, wait for send
            server->buf->idx = 0;
            ev_io_stop(EV_A_ & remote_recv_ctx->io);
            ev_io_start(EV_A_ & server->send_ctx->io);
            return;
        } else {
            ERROR("remote_recv_cb_send");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    } else if (s < server->buf->len) {
        server->buf->len -= s;
        server->buf->idx  = s;
        ev_io_stop(EV_A_ & remote_recv_ctx->io);
        ev_io_start(EV_A_ & server->send_ctx->io);
        return;
    }
//.........这里部分代码省略.........

static void server_recv_cb(EV_P_ ev_io *w, int revents)
{
    struct server_ctx *server_recv_ctx = (struct server_ctx *)w;
    struct server *server = server_recv_ctx->server;
    struct remote *remote = NULL;

    int len = server->buf_len;
    char **buf = &server->buf;

    ev_timer_again(EV_A_ & server->recv_ctx->watcher);

    if (server->stage != 0) {
        remote = server->remote;
        buf = &remote->buf;
        len = 0;
    }

    ssize_t r = recv(server->fd, *buf + len, BUF_SIZE - len, 0);

    if (r == 0) {
        // connection closed
        if (verbose) {
            LOGI("server_recv close the connection");
        }
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else if (r == -1) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // no data
            // continue to wait for recv
            return;
        } else {
            ERROR("server recv");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    }

    tx += r;

    // handle incomplete header
    if (server->stage == 0) {
        r += server->buf_len;
        if (r <= enc_get_iv_len()) {
            // wait for more
            if (verbose) {
#ifdef __MINGW32__
                LOGI("imcomplete header: %u", r);
#else
                LOGI("imcomplete header: %zu", r);
#endif
            }
            server->buf_len = r;
            return;
        } else {
            server->buf_len = 0;
        }
    }

    *buf = ss_decrypt(BUF_SIZE, *buf, &r, server->d_ctx);

    if (*buf == NULL) {
        LOGE("invalid password or cipher");
        report_addr(server->fd);
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    }

    // handshake and transmit data
    if (server->stage == 5) {
        if (server->auth && !ss_check_hash(&remote->buf, &r, server->chunk, server->d_ctx, BUF_SIZE)) {
            LOGE("hash error");
            report_addr(server->fd);
            close_and_free_server(EV_A_ server);
            close_and_free_remote(EV_A_ remote);
            return;
        }
        int s = send(remote->fd, remote->buf, r, 0);
        if (s == -1) {
            if (errno == EAGAIN || errno == EWOULDBLOCK) {
                // no data, wait for send
                remote->buf_len = r;
                remote->buf_idx = 0;
                ev_io_stop(EV_A_ & server_recv_ctx->io);
                ev_io_start(EV_A_ & remote->send_ctx->io);
            } else {
                ERROR("server_recv_send");
                close_and_free_remote(EV_A_ remote);
                close_and_free_server(EV_A_ server);
            }
        } else if (s < r) {
            remote->buf_len = r - s;
            remote->buf_idx = s;
            ev_io_stop(EV_A_ & server_recv_ctx->io);
            ev_io_start(EV_A_ & remote->send_ctx->io);
        }
        return;
//.........这里部分代码省略.........

static void
server_recv_cb(EV_P_ ev_io *w, int revents)
{
    server_ctx_t *server_recv_ctx = (server_ctx_t *)w;
    server_t *server              = server_recv_ctx->server;
    remote_t *remote              = server->remote;

    ssize_t r = recv(server->fd, remote->buf->array + remote->buf->len,
                     BUF_SIZE - remote->buf->len, 0);

    if (r == 0) {
        // connection closed
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else if (r == -1) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // no data
            // continue to wait for recv
            return;
        } else {
            ERROR("server recv");
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    }

    remote->buf->len += r;

    if (verbose) {
        uint16_t port = 0;
        char ipstr[INET6_ADDRSTRLEN];
        memset(&ipstr, 0, INET6_ADDRSTRLEN);

        if (AF_INET == server->destaddr.ss_family) {
            struct sockaddr_in *sa = (struct sockaddr_in *)&(server->destaddr);
            dns_ntop(AF_INET, &(sa->sin_addr), ipstr, INET_ADDRSTRLEN);
            port = ntohs(sa->sin_port);
        } else {
            // TODO: The code below need to be test in IPv6 envirment, which I
            //       don't have.
            struct sockaddr_in6 *sa = (struct sockaddr_in6 *)&(server->destaddr);
            dns_ntop(AF_INET6, &(sa->sin6_addr), ipstr, INET6_ADDRSTRLEN);
            port = ntohs(sa->sin6_port);
        }

        LOGI("redir to %s:%d, len=%zd, recv=%zd", ipstr, port, remote->buf->len, r);
    }

    if (auth) {
        ss_gen_hash(remote->buf, &remote->counter, server->e_ctx, BUF_SIZE);
    }

    if (!remote->send_ctx->connected) {
        // SNI
        int ret       = 0;
        uint16_t port = 0;

        if (AF_INET6 == server->destaddr.ss_family) { // IPv6
            port = ntohs(((struct sockaddr_in6 *)&(server->destaddr))->sin6_port);
        } else {                             // IPv4
            port = ntohs(((struct sockaddr_in *)&(server->destaddr))->sin_port);
        }
        if (port == http_protocol->default_port)
            ret = http_protocol->parse_packet(remote->buf->array,
                                              remote->buf->len, &server->hostname);
        else if (port == tls_protocol->default_port)
            ret = tls_protocol->parse_packet(remote->buf->array,
                                             remote->buf->len, &server->hostname);
        if (ret > 0) {
            server->hostname_len = ret;
        }

        ev_io_stop(EV_A_ & server_recv_ctx->io);
        ev_io_start(EV_A_ & remote->send_ctx->io);
        return;
    }

    int err = ss_encrypt(remote->buf, server->e_ctx, BUF_SIZE);

    if (err) {
        LOGE("invalid password or cipher");
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    }

    int s = send(remote->fd, remote->buf->array, remote->buf->len, 0);

    if (s == -1) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // no data, wait for send
            remote->buf->idx = 0;
            ev_io_stop(EV_A_ & server_recv_ctx->io);
            ev_io_start(EV_A_ & remote->send_ctx->io);
            return;
        } else {
            ERROR("send");
            close_and_free_remote(EV_A_ remote);
//.........这里部分代码省略.........

static void
remote_send_cb(EV_P_ ev_io *w, int revents)
{
    remote_ctx_t *remote_send_ctx = (remote_ctx_t *)w;
    remote_t *remote              = remote_send_ctx->remote;
    server_t *server              = remote->server;

    if (!remote_send_ctx->connected) {
        struct sockaddr_storage addr;
        socklen_t len = sizeof addr;
        int r         = getpeername(remote->fd, (struct sockaddr *)&addr, &len);
        if (r == 0) {
            remote_send_ctx->connected = 1;
            ev_io_stop(EV_A_ & remote_send_ctx->io);
            ev_io_stop(EV_A_ & server->recv_ctx->io);
            ev_timer_stop(EV_A_ & remote_send_ctx->watcher);
            ev_timer_start(EV_A_ & remote->recv_ctx->watcher);

            // send destaddr
            buffer_t ss_addr_to_send;
            buffer_t *abuf = &ss_addr_to_send;
            balloc(abuf, BUF_SIZE);

            if (server->hostname_len > 0) { // HTTP/SNI
                uint16_t port;
                if (AF_INET6 == server->destaddr.ss_family) { // IPv6
                    port = (((struct sockaddr_in6 *)&(server->destaddr))->sin6_port);
                } else {                             // IPv4
                    port = (((struct sockaddr_in *)&(server->destaddr))->sin_port);
                }

                abuf->array[abuf->len++] = 3;          // Type 3 is hostname
                abuf->array[abuf->len++] = server->hostname_len;
                memcpy(abuf->array + abuf->len, server->hostname, server->hostname_len);
                abuf->len += server->hostname_len;
                memcpy(abuf->array + abuf->len, &port, 2);
            } else if (AF_INET6 == server->destaddr.ss_family) { // IPv6
                abuf->array[abuf->len++] = 4;          // Type 4 is IPv6 address

                size_t in6_addr_len = sizeof(struct in6_addr);
                memcpy(abuf->array + abuf->len,
                       &(((struct sockaddr_in6 *)&(server->destaddr))->sin6_addr),
                       in6_addr_len);
                abuf->len += in6_addr_len;
                memcpy(abuf->array + abuf->len,
                       &(((struct sockaddr_in6 *)&(server->destaddr))->sin6_port),
                       2);
            } else {                             // IPv4
                abuf->array[abuf->len++] = 1; // Type 1 is IPv4 address

                size_t in_addr_len = sizeof(struct in_addr);
                memcpy(abuf->array + abuf->len,
                       &((struct sockaddr_in *)&(server->destaddr))->sin_addr, in_addr_len);
                abuf->len += in_addr_len;
                memcpy(abuf->array + abuf->len,
                       &((struct sockaddr_in *)&(server->destaddr))->sin_port, 2);
            }

            abuf->len += 2;

            if (auth) {
                abuf->array[0] |= ONETIMEAUTH_FLAG;
                ss_onetimeauth(abuf, server->e_ctx->evp.iv, BUF_SIZE);
            }

            brealloc(remote->buf, remote->buf->len + abuf->len, BUF_SIZE);
            memmove(remote->buf->array + abuf->len, remote->buf->array, remote->buf->len);
            memcpy(remote->buf->array, abuf->array, abuf->len);
            remote->buf->len += abuf->len;
            bfree(abuf);

            int err = ss_encrypt(remote->buf, server->e_ctx, BUF_SIZE);
            if (err) {
                LOGE("invalid password or cipher");
                close_and_free_remote(EV_A_ remote);
                close_and_free_server(EV_A_ server);
                return;
            }

            ev_io_start(EV_A_ & remote->recv_ctx->io);
        } else {
            ERROR("getpeername");
            // not connected
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    }

    if (remote->buf->len == 0) {
        // close and free
        close_and_free_remote(EV_A_ remote);
        close_and_free_server(EV_A_ server);
        return;
    } else {
        // has data to send
        ssize_t s = send(remote->fd, remote->buf->array + remote->buf->idx,
                         remote->buf->len, 0);
        if (s == -1) {
            if (errno != EAGAIN && errno != EWOULDBLOCK) {
//.........这里部分代码省略.........

static void remote_send_cb(EV_P_ ev_io *w, int revents)
{
    struct remote_ctx *remote_send_ctx = (struct remote_ctx *)w;
    struct remote *remote = remote_send_ctx->remote;
    struct server *server = remote->server;

    if (!remote_send_ctx->connected) {
        struct sockaddr_storage addr;
        socklen_t len = sizeof addr;

        int r = getpeername(remote->fd, (struct sockaddr *)&addr, &len);
        if (r == 0) {
            remote_send_ctx->connected = 1;
            ev_io_stop(EV_A_ & remote_send_ctx->io);
            ev_timer_stop(EV_A_ & remote_send_ctx->watcher);
            char *ss_addr_to_send = malloc(BUF_SIZE);
            ssize_t addr_len = 0;

            ss_addr_t *sa = &server->destaddr;
            struct cork_ip ip;
            if (cork_ip_init(&ip, sa->host) != -1) {
                if (ip.version == 4) {
                    // send as IPv4
                    struct in_addr host;
                    int host_len = sizeof(struct in_addr);

                    if (dns_pton(AF_INET, sa->host, &host) == -1) {
                        FATAL("IP parser error");
                    }
                    ss_addr_to_send[addr_len++] = 1;
                    memcpy(ss_addr_to_send + addr_len, &host, host_len);
                    addr_len += host_len;
                } else if (ip.version == 6) {
                    // send as IPv6
                    struct in6_addr host;
                    int host_len = sizeof(struct in6_addr);

                    if (dns_pton(AF_INET6, sa->host, &host) == -1) {
                        FATAL("IP parser error");
                    }
                    ss_addr_to_send[addr_len++] = 4;
                    memcpy(ss_addr_to_send + addr_len, &host, host_len);
                    addr_len += host_len;
                } else {
                    FATAL("IP parser error");
                }
            } else {
                // send as domain
                int host_len = strlen(sa->host);

                ss_addr_to_send[addr_len++] = 3;
                ss_addr_to_send[addr_len++] = host_len;
                memcpy(ss_addr_to_send + addr_len, sa->host, host_len);
                addr_len += host_len;
            }

            uint16_t port = htons(atoi(sa->port));
            memcpy(ss_addr_to_send + addr_len, &port, 2);
            addr_len += 2;

            ss_addr_to_send = ss_encrypt(BUF_SIZE, ss_addr_to_send, &addr_len,
                                         server->e_ctx);
            if (ss_addr_to_send == NULL) {
                LOGE("invalid password or cipher");
                close_and_free_remote(EV_A_ remote);
                close_and_free_server(EV_A_ server);
                return;
            }

            int s = send(remote->fd, ss_addr_to_send, addr_len, 0);
            free(ss_addr_to_send);

            if (s < addr_len) {
                LOGE("failed to send addr");
                close_and_free_remote(EV_A_ remote);
                close_and_free_server(EV_A_ server);
                return;
            }

            ev_io_start(EV_A_ & remote->recv_ctx->io);
            ev_io_start(EV_A_ & server->recv_ctx->io);

            return;
        } else {
            ERROR("getpeername");
            // not connected
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        }
    } else {
        if (remote->buf_len == 0) {
            // close and free
            close_and_free_remote(EV_A_ remote);
            close_and_free_server(EV_A_ server);
            return;
        } else {
            // has data to send
            ssize_t s = send(remote->fd, remote->buf + remote->buf_idx,
                             remote->buf_len, 0);
//.........这里部分代码省略.........

static void
remote_send_cb(EV_P_ ev_io *w, int revents)
{
    remote_ctx_t *remote_send_ctx = (remote_ctx_t *)w;
    remote_t *remote              = remote_send_ctx->remote;
    server_t *server              = remote->server;

    ev_timer_stop(EV_A_ & remote_send_ctx->watcher);

    if (!remote_send_ctx->connected) {
        int r = 0;
        if (remote->addr == NULL) {
            struct sockaddr_storage addr;
            memset(&addr, 0, sizeof(struct sockaddr_storage));
            socklen_t len = sizeof addr;
            r = getpeername(remote->fd, (struct sockaddr *)&addr, &len);
        }
        if (r == 0) {
            remote_send_ctx->connected = 1;

            ev_io_stop(EV_A_ & remote_send_ctx->io);
            ev_io_stop(EV_A_ & server->recv_ctx->io);
            ev_io_start(EV_A_ & remote->recv_ctx->io);
            ev_timer_start(EV_A_ & remote->recv_ctx->watcher);

            // send destaddr
            buffer_t ss_addr_to_send;
            buffer_t *abuf = &ss_addr_to_send;
            balloc(abuf, BUF_SIZE);

            if (server->hostname_len > 0
                    && validate_hostname(server->hostname, server->hostname_len)) { // HTTP/SNI
                uint16_t port;
                if (AF_INET6 == server->destaddr.ss_family) { // IPv6
                    port = (((struct sockaddr_in6 *)&(server->destaddr))->sin6_port);
                } else {                             // IPv4
                    port = (((struct sockaddr_in *)&(server->destaddr))->sin_port);
                }

                abuf->data[abuf->len++] = 3;          // Type 3 is hostname
                abuf->data[abuf->len++] = server->hostname_len;
                memcpy(abuf->data + abuf->len, server->hostname, server->hostname_len);
                abuf->len += server->hostname_len;
                memcpy(abuf->data + abuf->len, &port, 2);
            } else if (AF_INET6 == server->destaddr.ss_family) { // IPv6
                abuf->data[abuf->len++] = 4;          // Type 4 is IPv6 address

                size_t in6_addr_len = sizeof(struct in6_addr);
                memcpy(abuf->data + abuf->len,
                       &(((struct sockaddr_in6 *)&(server->destaddr))->sin6_addr),
                       in6_addr_len);
                abuf->len += in6_addr_len;
                memcpy(abuf->data + abuf->len,
                       &(((struct sockaddr_in6 *)&(server->destaddr))->sin6_port),
                       2);
            } else {                             // IPv4
                abuf->data[abuf->len++] = 1; // Type 1 is IPv4 address

                size_t in_addr_len = sizeof(struct in_addr);
                memcpy(abuf->data + abuf->len,
                       &((struct sockaddr_in *)&(server->destaddr))->sin_addr, in_addr_len);
                abuf->len += in_addr_len;
                memcpy(abuf->data + abuf->len,
                       &((struct sockaddr_in *)&(server->destaddr))->sin_port, 2);
            }

            abuf->len += 2;

            int err = crypto->encrypt(abuf, server->e_ctx, BUF_SIZE);
            if (err) {
                LOGE("invalid password or cipher");
                bfree(abuf);
                close_and_free_remote(EV_A_ remote);
                close_and_free_server(EV_A_ server);
                return;
            }