guacamole-spice-protocol/protocols/ssh/src/ssh_terminal_handlers.c

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is libguac-client-ssh.
 *
 * The Initial Developer of the Original Code is
 * Michael Jumper.
 * Portions created by the Initial Developer are Copyright (C) 2011
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include <stdlib.h>
#include <string.h>

#include <cairo/cairo.h>
#include <pango/pangocairo.h>

#include <guacamole/log.h>
#include <guacamole/guacio.h>
#include <guacamole/protocol.h>
#include <guacamole/client.h>

#include "ssh_terminal.h"
#include "ssh_terminal_handlers.h"

int ssh_guac_terminal_echo(ssh_guac_terminal* term, char c) {

    GUACIO* io = term->client->io;

    /* Wrap if necessary */
    if (term->cursor_col >= term->term_width) {
        term->cursor_col = 0;
        term->cursor_row++;
    }

    /* Scroll up if necessary */
    if (term->cursor_row >= term->term_height) {
        term->cursor_row = term->term_height - 1;
        
        /* Copy screen up by one row */
        guac_send_copy(io,
                GUAC_DEFAULT_LAYER, 0, term->char_height,
                term->char_width * term->term_width,
                term->char_height * (term->term_height - 1),
                GUAC_COMP_SRC, GUAC_DEFAULT_LAYER, 0, 0);

        /* Fill bottom row with background */
        guac_send_rect(io,
                GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                0, term->char_height * (term->term_height - 1),
                term->char_width * term->term_width,
                term->char_height * term->term_height,
                0, 0, 0, 255);

    }

    switch (c) {

        /* Bell */
        case 0x07:
            break;

        /* Backspace */
        case 0x08:
            if (term->cursor_col >= 1)
                term->cursor_col--;
            break;

        /* Carriage return */
        case '\r':
            term->cursor_col = 0;
            break;

        /* Line feed */
        case '\n':
            term->cursor_row++;
            break;

        /* ESC */
        case 0x1B:
            term->char_handler = ssh_guac_terminal_escape; 
            break;

        /* Displayable chars */
        default:
            ssh_guac_terminal_send_glyph(term,
                    term->cursor_row,
                    term->cursor_col,
                    c);

            /* Advance cursor */
            term->cursor_col++;
    }

    return 0;

}

int ssh_guac_terminal_escape(ssh_guac_terminal* term, char c) {

    switch (c) {

        case '(':
            term->char_handler = ssh_guac_terminal_charset; 
            break;

        case ']':
            term->char_handler = ssh_guac_terminal_osc; 
            break;

        case '[':
            term->char_handler = ssh_guac_terminal_csi; 
            break;

        default:
            guac_log_info("Unhandled ESC sequence: %c", c);
            term->char_handler = ssh_guac_terminal_echo; 

    }

    return 0;

}

int ssh_guac_terminal_charset(ssh_guac_terminal* term, char c) {
    term->char_handler = ssh_guac_terminal_echo; 
    return 0;
}

int ssh_guac_terminal_csi(ssh_guac_terminal* term, char c) {

    GUACIO* io = term->client->io;

    /* CSI function arguments */
    static int argc = 0;
    static int argv[16];

    /* Argument building counter and buffer */
    static int argv_length = 0;
    static char argv_buffer[256];

    /* FIXME: "The sequence of parameters may be preceded by a single question mark. */
    if (c == '?')
        return 0;

    /* Digits get concatenated into argv */
    if (c >= '0' && c <= '9') {

        /* Concatenate digit if there is space in buffer */
        if (argv_length < sizeof(argv_buffer)-1)
            argv_buffer[argv_length++] = c;

    }

    /* Any non-digit stops the parameter, and possibly the sequence */
    else {

        /* At most 16 parameters */
        if (argc < 16) {

            /* Finish parameter */
            argv_buffer[argv_length] = 0;
            argv[argc++] = atoi(argv_buffer);

            /* Prepare for next parameter */
            argv_length = 0;

        }

        /* Handle CSI functions */ 
        switch (c) {

            /* H: Move cursor */
            case 'H':
                term->cursor_row = argv[0] - 1;
                term->cursor_col = argv[1] - 1;
                break;

            /* J: Erase display */
            case 'J':

                /* Erase from cursor to end of display */
                if (argv[0] == 0) {

                    /* Until end of line */
                    guac_send_rect(io,
                            GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                            term->cursor_col * term->char_width,
                            term->cursor_row * term->char_height,
                            (term->term_width - term->cursor_col) * term->char_width,
                            term->char_height,
                            0, 0, 0, 255); /* Background color */

                    /* Until end of display */
                    if (term->cursor_row < term->term_height - 1) {
                        guac_send_rect(io,
                                GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                                0,
                                (term->cursor_row+1) * term->char_height,
                                term->term_width * term->char_width,
                                term->term_height * term->char_height,
                                0, 0, 0, 255); /* Background color */
                    }

                }
                
                /* Erase from start to cursor */
                else if (argv[0] == 1) {

                    /* Until start of line */
                    guac_send_rect(io,
                            GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                            0,
                            term->cursor_row * term->char_height,
                            term->cursor_col * term->char_width,
                            term->char_height,
                            0, 0, 0, 255); /* Background color */

                    /* From start */
                    if (term->cursor_row >= 1) {
                        guac_send_rect(io,
                                GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                                0,
                                0,
                                term->term_width * term->char_width,
                                (term->cursor_row-1) * term->char_height,
                                0, 0, 0, 255); /* Background color */
                    }

                }

                /* Entire screen */
                else if (argv[0] == 2) {
                    guac_send_rect(io,
                            GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                            0,
                            0,
                            term->term_width * term->char_width,
                            term->term_height * term->char_height,
                            0, 0, 0, 255); /* Background color */
                }

                break;

            /* K: Erase line */
            case 'K':

                /* Erase from cursor to end of line */
                if (argv[0] == 0) {
                    guac_send_rect(io,
                            GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                            term->cursor_col * term->char_width,
                            term->cursor_row * term->char_height,
                            (term->term_width - term->cursor_col) * term->char_width,
                            term->char_height,
                            0, 0, 0, 255); /* Background color */
                }

                /* Erase from start to cursor */
                else if (argv[0] == 1) {
                    guac_send_rect(io,
                            GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                            0,
                            term->cursor_row * term->char_height,
                            term->cursor_col * term->char_width,
                            term->char_height,
                            0, 0, 0, 255); /* Background color */
                }

                /* Erase line */
                else if (argv[0] == 2) {
                    guac_send_rect(io,
                            GUAC_COMP_SRC, GUAC_DEFAULT_LAYER,
                            0,
                            term->cursor_row * term->char_height,
                            term->term_width * term->char_width,
                            term->char_height,
                            0, 0, 0, 255); /* Background color */
                }

                break;

            /* Warn of unhandled codes */
            default:
                if (c != ';')
                    guac_log_info("Unhandled CSI sequence: %c", c);

        }

        /* If not a semicolon, end of CSI sequence */
        if (c != ';') {
            term->char_handler = ssh_guac_terminal_echo;

            /* Reset argument counters */
            argc = 0;
            argv_length = 0;
        }

    }

    return 0;

}

int ssh_guac_terminal_osc(ssh_guac_terminal* term, char c) {
    /* TODO: Implement OSC */
    if (c == 0x9C || c == 0x5C || c == 0x07) /* ECMA-48 ST (String Terminator */
       term->char_handler = ssh_guac_terminal_echo; 
    return 0;
}