source: mainline/uspace/srv/hid/remcons/remcons.c@ 4daee7a

/*
 * Copyright (c) 2012 Vojtech Horky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup remcons
 * @{
 */
/** @file
 */

#include <async.h>
#include <errno.h>
#include <io/con_srv.h>
#include <stdio.h>
#include <stdlib.h>
#include <str_error.h>
#include <loc.h>
#include <event.h>
#include <io/keycode.h>
#include <align.h>
#include <fibril_synch.h>
#include <task.h>
#include <net/in.h>
#include <net/inet.h>
#include <net/socket.h>
#include <io/console.h>
#include <inttypes.h>
#include "telnet.h"
#include "user.h"

#define APP_GETTERM  "/app/getterm"
#define APP_SHELL "/app/bdsh"

/** Telnet commands to force character mode
 * (redundant to be on the safe side).
 * See
 * http://stackoverflow.com/questions/273261/force-telnet-user-into-character-mode
 * for discussion.
 */
static const telnet_cmd_t telnet_force_character_mode_command[] = {
        TELNET_IAC, TELNET_WILL, TELNET_ECHO,
        TELNET_IAC, TELNET_WILL, TELNET_SUPPRESS_GO_AHEAD,
        TELNET_IAC, TELNET_WONT, TELNET_LINEMODE
};

static const size_t telnet_force_character_mode_command_count =
    sizeof(telnet_force_character_mode_command) / sizeof(telnet_cmd_t);

static int remcons_open(con_srvs_t *, con_srv_t *);
static int remcons_close(con_srv_t *);
static int remcons_write(con_srv_t *, void *, size_t);
static void remcons_sync(con_srv_t *);
static void remcons_clear(con_srv_t *);
static void remcons_set_pos(con_srv_t *, sysarg_t col, sysarg_t row);
static int remcons_get_pos(con_srv_t *, sysarg_t *, sysarg_t *);
static int remcons_get_size(con_srv_t *, sysarg_t *, sysarg_t *);
static int remcons_get_color_cap(con_srv_t *, console_caps_t *);
static int remcons_get_event(con_srv_t *, kbd_event_t *);

static con_ops_t con_ops = {
        .open = remcons_open,
        .close = remcons_close,
        .read = NULL,
        .write = remcons_write,
        .sync = remcons_sync,
        .clear = remcons_clear,
        .set_pos = remcons_set_pos,
        .get_pos = remcons_get_pos,
        .get_size = remcons_get_size,
        .get_color_cap = remcons_get_color_cap,
        .set_style = NULL,
        .set_color = NULL,
        .set_rgb_color = NULL,
        .set_cursor_visibility = NULL,
        .get_event = remcons_get_event
};

static telnet_user_t *srv_to_user(con_srv_t *srv)
{
        return srv->srvs->sarg;
}

static int remcons_open(con_srvs_t *srvs, con_srv_t *srv)
{
        telnet_user_t *user = srv_to_user(srv);

        telnet_user_log(user, "New client connected (%p).", srv);

        /* Force character mode. */
        send(user->socket, (void *)telnet_force_character_mode_command,
            telnet_force_character_mode_command_count, 0);

        return EOK;
}

static int remcons_close(con_srv_t *srv)
{
        telnet_user_t *user = srv_to_user(srv);

        telnet_user_notify_client_disconnected(user);
        telnet_user_log(user, "Client disconnected (%p).", srv);

        return EOK;
}

static int remcons_write(con_srv_t *srv, void *data, size_t size)
{
        telnet_user_t *user = srv_to_user(srv);
        int rc;

        rc = telnet_user_send_data(user, data, size);
        if (rc != EOK)
                return rc;

        return size;
}

static void remcons_sync(con_srv_t *srv)
{
        (void) srv;
}

static void remcons_clear(con_srv_t *srv)
{
        (void) srv;
}

static void remcons_set_pos(con_srv_t *srv, sysarg_t col, sysarg_t row)
{
        telnet_user_t *user = srv_to_user(srv);

        telnet_user_update_cursor_x(user, col);
}

static int remcons_get_pos(con_srv_t *srv, sysarg_t *col, sysarg_t *row)
{
        telnet_user_t *user = srv_to_user(srv);

        *col = user->cursor_x;
        *row = 0;

        return EOK;
}

static int remcons_get_size(con_srv_t *srv, sysarg_t *cols, sysarg_t *rows)
{
        (void) srv;

        *cols = 100;
        *rows = 1;

        return EOK;
}

static int remcons_get_color_cap(con_srv_t *srv, console_caps_t *ccaps)
{
        (void) srv;
        *ccaps = CONSOLE_CAP_NONE;

        return EOK;
}

static int remcons_get_event(con_srv_t *srv, kbd_event_t *event)
{
        telnet_user_t *user = srv_to_user(srv);
        int rc;

        rc = telnet_user_get_next_keyboard_event(user, event);
        if (rc != EOK) {
                /* XXX What? */
                memset(event, 0, sizeof(*event));
                return EOK;
        }

        return EOK;
}

/** Callback when client connects to a telnet terminal. */
static void client_connection(ipc_callid_t iid, ipc_call_t *icall, void *arg)
{
        /* Find the user. */
        telnet_user_t *user = telnet_user_get_for_client_connection(IPC_GET_ARG1(*icall));
        if (user == NULL) {
                async_answer_0(iid, ENOENT);
                return;
        }

        /* Handle messages. */
        con_conn(iid, icall, &user->srvs);
}

/** Fibril for spawning the task running after user connects.
 *
 * @param arg Corresponding @c telnet_user_t structure.
 */
static int spawn_task_fibril(void *arg)
{
        telnet_user_t *user = arg;
        int rc;

        char term[LOC_NAME_MAXLEN];
        snprintf(term, LOC_NAME_MAXLEN, "%s/%s", "/loc", user->service_name);

        task_id_t task;
        rc = task_spawnl(&task, APP_GETTERM, APP_GETTERM, "-w", term, APP_SHELL, NULL);
        if (rc != EOK) {
                telnet_user_error(user, "Spawning `%s -w %s %s' failed: %s.",
                    APP_GETTERM, term, APP_SHELL, str_error(rc));
                fibril_mutex_lock(&user->guard);
                user->task_finished = true;
                user->srvs.aborted = true;
                fibril_condvar_signal(&user->refcount_cv);
                fibril_mutex_unlock(&user->guard);
                return EOK;
        }

        fibril_mutex_lock(&user->guard);
        user->task_id = task;
        fibril_mutex_unlock(&user->guard);

        task_exit_t task_exit;
        int task_retval;
        task_wait(task, &task_exit, &task_retval);
        telnet_user_log(user, "%s terminated %s, exit code %d.", APP_GETTERM,
            task_exit == TASK_EXIT_NORMAL ? "normally" : "unexpectedly",
            task_retval);

        /* Announce destruction. */
        fibril_mutex_lock(&user->guard);
        user->task_finished = true;
        user->srvs.aborted = true;
        fibril_condvar_signal(&user->refcount_cv);
        fibril_mutex_unlock(&user->guard);

        return EOK;
}

/** Tell whether given user can be destroyed (has no active clients).
 *
 * @param user The telnet user in question.
 */
static bool user_can_be_destroyed_no_lock(telnet_user_t *user)
{
        return user->task_finished && user->socket_closed &&
            (user->locsrv_connection_count == 0);
}

/** Fibril for each accepted socket.
 *
 * @param arg Corresponding @c telnet_user_t structure.
 */
static int network_user_fibril(void *arg)
{
        telnet_user_t *user = arg;

        int rc = loc_service_register(user->service_name, &user->service_id);
        if (rc != EOK) {
                telnet_user_error(user, "Unable to register %s with loc: %s.",
                    user->service_name, str_error(rc));
                return EOK;
        }

        telnet_user_log(user, "Service %s registerd with id %" PRIun ".",
            user->service_name, user->service_id);
        
        fid_t spawn_fibril = fibril_create(spawn_task_fibril, user);
        assert(spawn_fibril);
        fibril_add_ready(spawn_fibril);
        
        /* Wait for all clients to exit. */
        fibril_mutex_lock(&user->guard);
        while (!user_can_be_destroyed_no_lock(user)) {
                if (user->task_finished) {
                        closesocket(user->socket);
                        user->socket_closed = true;
                        user->srvs.aborted = true;
                        continue;
                } else if (user->socket_closed) {
                        if (user->task_id != 0) {
                                task_kill(user->task_id);
                        }
                }
                fibril_condvar_wait_timeout(&user->refcount_cv, &user->guard, 1000);
        }
        fibril_mutex_unlock(&user->guard);
        
        rc = loc_service_unregister(user->service_id);
        if (rc != EOK) {
                telnet_user_error(user,
                    "Unable to unregister %s from loc: %s (ignored).",
                    user->service_name, str_error(rc));
        }

        telnet_user_log(user, "Destroying...");
        telnet_user_destroy(user);

        return EOK;
}

int main(int argc, char *argv[])
{
        int port = 2223;
        
        async_set_client_connection(client_connection);
        int rc = loc_server_register(NAME);
        if (rc != EOK) {
                fprintf(stderr, "%s: Unable to register server\n", NAME);
                return rc;
        }
        
        struct sockaddr_in addr;
        
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        
        rc = inet_pton(AF_INET, "127.0.0.1", (void *)
            &addr.sin_addr.s_addr);
        if (rc != EOK) {
                fprintf(stderr, "Error parsing network address: %s.\n",
                    str_error(rc));
                return 2;
        }

        int listen_sd = socket(PF_INET, SOCK_STREAM, 0);
        if (listen_sd < 0) {
                fprintf(stderr, "Error creating listening socket: %s.\n",
                    str_error(listen_sd));
                return 3;
        }

        rc = bind(listen_sd, (struct sockaddr *) &addr, sizeof(addr));
        if (rc != EOK) {
                fprintf(stderr, "Error binding socket: %s.\n",
                    str_error(rc));
                return 4;
        }

        rc = listen(listen_sd, BACKLOG_SIZE);
        if (rc != EOK) {
                fprintf(stderr, "listen() failed: %s.\n", str_error(rc));
                return 5;
        }

        printf("%s: HelenOS Remote console service\n", NAME);
        task_retval(0);

        while (true) {
                struct sockaddr_in raddr;
                socklen_t raddr_len = sizeof(raddr);
                int conn_sd = accept(listen_sd, (struct sockaddr *) &raddr,
                    &raddr_len);

                if (conn_sd < 0) {
                        fprintf(stderr, "accept() failed: %s.\n",
                            str_error(rc));
                        continue;
                }

                telnet_user_t *user = telnet_user_create(conn_sd);
                assert(user);

                con_srvs_init(&user->srvs);
                user->srvs.ops = &con_ops;
                user->srvs.sarg = user;
                user->srvs.abort_timeout = 1000;

                telnet_user_add(user);

                fid_t fid = fibril_create(network_user_fibril, user);
                assert(fid);
                fibril_add_ready(fid);
        }

        return 0;
}

/** @}
 */