/*
 
  silccommand.h
 
  Author: Pekka Riikonen <priikone@silcnet.org>
 
  Copyright (C) 1997 - 2001 Pekka Riikonen
 
  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 2 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.

*/

/****h* silccore/SILC Command Interface
 *
 * DESCRIPTION
 *
 * Implementation of the Command Payload. The Command Payload is used to
 * send commands and also command replies usually between client and
 * server.
 *
 ***/

#ifndef SILCCOMMAND_H
#define SILCCOMMAND_H

/****f* silccore/SilcCommandAPI/SilcCommandCb
 *
 * SYNOPSIS
 *
 *    typedef void (*SilcCommandCb)(void *context, void *context2);
 *
 * DESCRIPTION
 *
 *    Command function callback. The actual command function pointer.
 *    This is generic command callback that the application may choose to
 *    use with its command routines.  However, none of the generic
 *    routines depend on this callback so application may freely define
 *    their own command callback if desired.
 *
 ***/
typedef void (*SilcCommandCb)(void *context, void *context2);

/****s* silccore/SilcCommandAPI/SilcCommandPayload
 *
 * NAME
 * 
 *    typedef struct SilcCommandPayloadStruct *SilcCommandPayload;
 *
 * DESCRIPTION
 *
 *    This context is the actual Command Payload and is allocated
 *    by silc_command_payload_parse and given as argument usually to
 *    all silc_command_payload_* functions.  It is freed by the
 *    silc_command_payload_free function.
 *
 ***/
typedef struct SilcCommandPayloadStruct *SilcCommandPayload;

/****d* silccore/SilcCommandAPI/SilcCommandFlags
 *
 * NAME
 * 
 *    typedef enum { ... } SilcCommandFlags;
 *
 * DESCRIPTION
 *
 *    Command flags that set how the commands behave on different
 *    situations. These can be OR'es together to set multiple flags.
 *    The application is resoponsible of implementing the behaviour
 *    of these flags. These are here just to define generic flags.
 *    The server usually makes use of these flags.
 *
 * SOURCE
 */
typedef enum {
  SILC_CF_NONE           = 0,

  /* Command may only be used once per (about) 2 seconds. Bursts up
     to 5 commands are allowed though. */
  SILC_CF_LAG            = (1L << 1),

  /* Command may only be used once per (about) 2 seconds. No bursts
     are allowed at all. */
  SILC_CF_LAG_STRICT     = (1L << 2),

  /* Command is available for registered connections (connections
     whose ID has been created. */
  SILC_CF_REG            = (1L << 3),

  /* Command is available only for server operators */
  SILC_CF_OPER           = (1L << 4),

  /* Command is available only for SILC (router) operators. If this 
     is set SILC_CF_OPER is not necessary to be set. */
  SILC_CF_SILC_OPER      = (1L << 5),

} SilcCommandFlag;
/***/

/****d* silccore/SilcCommandAPI/SilcCommand
 *
 * NAME
 * 
 *    typedef SilcUInt8 SilcCommand;
 *
 * DESCRIPTION
 *
 *    The SilcCommand type definition and the commands. The commands
 *    listed here are the official SILC Commands and they have client
 *    and server counterparts.
 *
 * SOURCE
 */
typedef SilcUInt8 SilcCommand;

/* All SILC commands. These are commands that have client and server
   counterparts. */
#define SILC_COMMAND_NONE               0
#define SILC_COMMAND_WHOIS		1
#define SILC_COMMAND_WHOWAS		2
#define SILC_COMMAND_IDENTIFY           3
#define SILC_COMMAND_NICK		4
#define SILC_COMMAND_LIST		5
#define SILC_COMMAND_TOPIC		6
#define SILC_COMMAND_INVITE		7
#define SILC_COMMAND_QUIT		8
#define SILC_COMMAND_KILL		9
#define SILC_COMMAND_INFO		10
#define SILC_COMMAND_STATS		11
#define SILC_COMMAND_PING		12
#define SILC_COMMAND_OPER		13
#define SILC_COMMAND_JOIN		14
#define SILC_COMMAND_MOTD		15
#define SILC_COMMAND_UMODE		16
#define SILC_COMMAND_CMODE		17
#define SILC_COMMAND_CUMODE		18
#define SILC_COMMAND_KICK		19
#define SILC_COMMAND_BAN		20
#define SILC_COMMAND_DETACH		21
#define SILC_COMMAND_WATCH		22
#define SILC_COMMAND_SILCOPER	        23
#define SILC_COMMAND_LEAVE		24
#define SILC_COMMAND_USERS		25
#define SILC_COMMAND_GETKEY		26
#define SILC_COMMAND_SERVICE		27

/* Private range start */
#define SILC_COMMAND_PRIVATE            200
#define SILC_COMMAND_PRIV_CONNECT       200
#define SILC_COMMAND_PRIV_CLOSE         201
#define SILC_COMMAND_PRIV_SHUTDOWN      202

/* Reserved */
#define SILC_COMMAND_RESERVED           255
/***/

/* Prototypes */

/****f* silccore/SilcCommandAPI/silc_command_payload_parse
 *
 * SYNOPSIS
 *
 *    SilcCommandPayload 
 *    silc_command_payload_parse(const unsigned char *payload,
 *                               SilcUInt32 payload_len);
 *
 * DESCRIPTION
 *
 *    Parses command payload returning new command payload structure. The
 *    `buffer' is the raw payload.
 *
 ***/
SilcCommandPayload silc_command_payload_parse(const unsigned char *payload,
					      SilcUInt32 payload_len);

/****f* silccore/SilcCommandAPI/silc_command_payload_encode
 *
 * SYNOPSIS
 *
 *    SilcBuffer silc_command_payload_encode(SilcCommand cmd,
 *                                           SilcUInt32 argc,
 *                                           unsigned char **argv,
 *                                           SilcUInt32 *argv_lens,
 *                                           SilcUInt32 *argv_types,
 *                                           SilcUInt16 ident);
 *
 * DESCRIPTION
 *
 *     Encodes Command Payload returning it to SilcBuffer.
 *
 ***/
SilcBuffer silc_command_payload_encode(SilcCommand cmd,
				       SilcUInt32 argc,
				       unsigned char **argv,
				       SilcUInt32 *argv_lens,
				       SilcUInt32 *argv_types,
				       SilcUInt16 ident);

/****f* silccore/SilcCommandAPI/silc_command_payload_encode_payload
 *
 * SYNOPSIS
 *
 *    SilcBuffer 
 *    silc_command_payload_encode_payload(SilcCommandPayload payload);
 *
 * DESCRIPTION
 *
 *    Same as silc_command_payload_encode but encodes the buffer from
 *    SilcCommandPayload structure instead of raw data.
 *
 ***/
SilcBuffer silc_command_payload_encode_payload(SilcCommandPayload payload);

/****f* silccore/SilcCommandAPI/silc_command_payload_encode_va
 *
 * SYNOPSIS
 *
 *    SilcBuffer silc_command_payload_encode_va(SilcCommand cmd, 
 *                                              SilcUInt16 ident, 
 *                                              SilcUInt32 argc, ...);
 *
 * DESCRIPTION
 *
 *    Encodes Command payload with variable argument list. The arguments
 *    must be: SilcUInt32, unsigned char *, unsigned int, ... One 
 *    {SilcUInt32, unsigned char * and unsigned int} forms one argument, 
 *    thus `argc' in case when sending one {SilcUInt32, unsigned char * 
 *    and SilcUInt32} equals one (1) and when sending two of those it
 *    equals two (2), and so on. This has to be preserved or bad things
 *    will happen. The variable arguments is: {type, data, data_len}.
 *
 ***/
SilcBuffer silc_command_payload_encode_va(SilcCommand cmd, 
					  SilcUInt16 ident, 
					  SilcUInt32 argc, ...);

/****f* silccore/SilcCommandAPI/silc_command_payload_encode_vap
 *
 * SYNOPSIS
 *
 *    SilcBuffer silc_command_payload_encode_vap(SilcCommand cmd, 
 *                                               SilcUInt16 ident, 
 *                                               SilcUInt32 argc, va_list ap);
 *
 * DESCRIPTION
 *
 *    This is equivalent to the silc_command_payload_encode_va except
 *    takes the va_list as argument.
 *
 ***/
SilcBuffer silc_command_payload_encode_vap(SilcCommand cmd, 
					   SilcUInt16 ident, 
					   SilcUInt32 argc, va_list ap);

/****f* silccore/SilcCommandAPI/silc_command_reply_payload_encode_va
 *
 * SYNOPSIS
 *
 *    SilcBuffer 
 *    silc_command_reply_payload_encode_va(SilcCommand cmd, 
 *                                         SilcStatus status,
 *                                         SilcStatus error,
 *                                         SilcUInt16 ident,
 *                                         SilcUInt32 argc, ...);
 *
 * DESCRIPTION
 *
 *    Same as silc_command_payload_encode_va except that this is used to 
 *    encode strictly command reply packets.  The `argc' must not count 
 *    `status' and `error' as arguments.  The `status' includes the
 *    command reply status.  If single reply will be sent then it includes
 *    SILC_STATUS_OK if error did not occur.  It includes an error value
 *    if error did occur.  In this case `error' field is ignored.  If
 *    there will be multiple successful command replies then the `status'
 *    includes a list value and `error' is ignored.  If there will
 *    multiple error replies the `status' includes a list value, and
 *    the `error' includes an error value.  Thus, the `error' value is
 *    specified only if there will be list of errors.
 *
 * NOTES
 *
 *    Protocol defines that it is possible to send both list of successful
 *    and list of error replies at the same time, as long as the error
 *    replies are sent after the successful replies.
 *
 ***/
SilcBuffer 
silc_command_reply_payload_encode_va(SilcCommand cmd, 
				     SilcStatus status,
				     SilcStatus error,
				     SilcUInt16 ident,
				     SilcUInt32 argc, ...);

/****f* silccore/SilcCommandAPI/silc_command_reply_payload_encode_vap
 *
 * SYNOPSIS
 *
 *    SilcBuffer 
 *    silc_command_reply_payload_encode_vap(SilcCommand cmd, 
 *                                          SilcStatus status,
 *                                          SilcStatus error,
 *                                          SilcUInt16 ident, SilcUInt32 argc,
 *                                          va_list ap);
 *
 * DESCRIPTION
 *
 *    This is equivalent to the silc_command_reply_payload_encode_va except
 *    takes the va_list as argument.
 *
 ***/
SilcBuffer 
silc_command_reply_payload_encode_vap(SilcCommand cmd, 
				      SilcStatus status,
				      SilcStatus error,
				      SilcUInt16 ident, SilcUInt32 argc, 
				      va_list ap);

/****f* silccore/SilcCommandAPI/silc_command_free
 *
 * SYNOPSIS
 *
 *    void silc_command_payload_free(SilcCommandPayload payload);
 *
 * DESCRIPTION
 *
 *    Frees the Command Payload and all data in it.
 *
 ***/
void silc_command_payload_free(SilcCommandPayload payload);

/****f* silccore/SilcCommandAPI/silc_command_get
 *
 * SYNOPSIS
 *
 *    SilcCommand silc_command_get(SilcCommandPayload payload);
 *
 * DESCRIPTION
 *
 *    Return the command from the payload.
 *
 ***/
SilcCommand silc_command_get(SilcCommandPayload payload);

/****f* silccore/SilcCommandAPI/silc_command_get_args
 *
 * SYNOPSIS
 *
 *    SilcArgumentPayload silc_command_get_args(SilcCommandPayload payload);
 *
 * DESCRIPTION
 *
 *    Return the Arguments Payload containing the arguments from the
 *    Command Payload. The caller must not free it.
 *
 ***/
SilcArgumentPayload silc_command_get_args(SilcCommandPayload payload);

/****f* silccore/SilcCommandAPI/silc_command_get_ident
 *
 * SYNOPSIS
 *
 *    SilcUInt16 silc_command_get_ident(SilcCommandPayload payload);
 *
 * DESCRIPTION
 *
 *    Return the command identifier from the payload. The identifier can
 *    be used to identify which command reply belongs to which command.
 *    The client sets the identifier to the payload and server must return
 *    the same identifier in the command reply.
 *
 ***/
SilcUInt16 silc_command_get_ident(SilcCommandPayload payload);

/****f* silccore/SilcCommandAPI/silc_command_get_status
 *
 * SYNOPSIS
 *
 *    bool silc_command_get_status(SilcCommandPayload payload, 
 *                                 SilcStatus *status,
 *                                 SilcStatus *error);
 *
 * DESCRIPTION
 *
 *    This function returns the command reply status into `status' and
 *    error status, if error occurred into the `error'.  The function
 *    returns TRUE if command reply status is not error, and FALSE if
 *    error occurred.  In this case the `error' will include the actual
 *    error status.  The `status' can be in this case some list value
 *    which indicates that there will be list of errors.
 *
 ***/
bool silc_command_get_status(SilcCommandPayload payload, 
			     SilcStatus *status,
			     SilcStatus *error);

/****f* silccore/SilcCommandAPI/silc_command_set_ident
 *
 * SYNOPSIS
 *
 *    void silc_command_set_ident(SilcCommandPayload payload, 
 *                                SilcUInt16 ident);
 *
 * DESCRIPTION
 *
 *    Function to set identifier to already allocated Command Payload. Command
 *    payloads are frequentlly resent in SILC and thusly this makes it easy
 *    to set the identifier without encoding new Command Payload. 
 *
 ***/
void silc_command_set_ident(SilcCommandPayload payload, SilcUInt16 ident);

/****f* silccore/SilcCommandAPI/silc_command_set_command
 *
 * SYNOPSIS
 *
 *    void silc_command_set_command(SilcCommandPayload payload, 
 *                                  SilcCommand command);
 *
 * DESCRIPTION
 *
 *    Function to set the command to already allocated Command Payload. This
 *    makes it easy to change the command in the payload without encoding new
 *    Command Payload.
 *
 ***/
void silc_command_set_command(SilcCommandPayload payload, SilcCommand command);

#endif
