telnet.h

/*-
 * Copyright (c) 1997 Dave Richards <dave@synergy.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * and exceptions are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. The name of the authors may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 * 4. The code can not be used by Gary Random, Random Communications, Inc.,
 *    the employees of Random Communications, Inc. or its subsidiaries,
 *    including Defiance MUD, without prior written permission from the
 *    authors.
 *
 * THIS SOFTWARE IS PROVIDED ``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 AUTHORS 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.
 */

/*
 * Telnet Option Block.
 */
typedef struct {
    u_char      o_us;
    u_char      o_usq;
    u_char      o_him;
    u_char      o_himq;
} opt_t;

/*
 * Option States.
 */
#define OS_NO                   0
#define OS_YES                  1
#define OS_WANTNO               2
#define OS_WANTYES              3

/*
 * Option Queue States.
 */
#define OQ_EMPTY                0
#define OQ_OPPOSITE             2

/*
 * Options.
 */
#define OP_ECHO                 0
#define OP_SGA                  1
#define OP_CDM                  2
#define OP_GMCP         3
#define OP_MSSP         4
#define OP_CHARSET      5
#define OP_SIZE         6

/*
 * Telnet Control Block.
 */
typedef struct {
    u_short     t_flags;
    u_char      t_state;
    u_char      t_opt;
    opt_t       t_optb[OP_SIZE];
    ndesc_t *   t_nd;
    nqueue_t *  t_rawq;
    nqueue_t *  t_canq; nqueue_t *      t_optq;
    nqueue_t *  t_outq;
    void *      t_ip;
    u_int       t_rblen;
    u_int       t_sblen;
    struct task *task;
} telnet_t;

/*
 * Telnet Flags.
 */
#define TF_ATTACH               0x0001
#define TF_INPUT        0x0002
#define TF_DISCONNECT   0x0004

#define TF_OVFLCANQ             0x0010
#define TF_OVFLOPTQ             0x0020
#define TF_OVFLOUTQ             0x0040
#define TF_SYNCH                0x0080
#define TF_URGENT               0x0100
#define TF_GA                   0x0200
#define TF_ECHO                 0x1000
#define TF_SGA                  0x2000
#define TF_GMCP         0x4000


/*
 * Telnet Input States.
 */
#define TS_DATA                 0
#define TS_CR                   1
#define TS_IAC                  2
#define TS_IAC_SB               3
#define TS_IAC_SB_DATA          4
#define TS_IAC_SB_IAC           5
#define TS_IAC_WILL             6
#define TS_IAC_WONT             7
#define TS_IAC_DO               8
#define TS_IAC_DONT             9

#define TELOPT_CHARSET  42
#define TELOPT_MSSP     70
#define TELOPT_GMCP     201
#define TELOPT_CDM              205

/*
 * MSSP Data Block
 */
typedef struct {
    u_char *name;
    size_t size;
    u_char *values[];
} mssp_t;

#define MSSP_VAR        1
#define MSSP_VAL        2

#define CHARSET_REQUEST     1
#define CHARSET_ACCEPTED    2
#define CHARSET_REJECTED    3

void telnet_detach(telnet_t *);
int  telnet_output(telnet_t *, u_char *);
int  telnet_output_gmcp(telnet_t *, u_char *);
int  telnet_output_mssp(telnet_t *, mssp_t *vars[], size_t count);
void telnet_enable_echo(telnet_t *);
void telnet_disable_echo(telnet_t *);
void telnet_enable_gmcp(telnet_t *);
void telnet_disable_gmcp(telnet_t *);
void telnet_init(u_short);