/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Implementation of Inter-Asterisk eXchange
 * 
 * Copyright (C) 2003, Digium
 *
 * Mark Spencer <markster@linux-support.net>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */

/*! \file
 * \brief
 *
 * Implementation of Inter-Asterisk eXchange, version 2
 * \ref iax2-parser.c
 * \ref iax2-parser.h
 * \ref chan_iax2.c
 */
 
#ifndef _IAX2_H
#define _IAX2_H

/* Max version of IAX protocol we support */
#define IAX_PROTO_VERSION 2

/* NOTE: IT IS CRITICAL THAT IAX_MAX_CALLS BE A POWER OF 2. */
#if defined(LOW_MEMORY)
#define IAX_MAX_CALLS 2048
#else
#define IAX_MAX_CALLS 32768
#endif

#define IAX_FLAG_FULL		0x8000

#define IAX_FLAG_RETRANS	0x8000

#define IAX_FLAG_SC_LOG		0x80

#define IAX_MAX_SHIFT		0x1F

#define IAX_WINDOW			64

/*! Subclass for AST_FRAME_IAX */
enum iax_frame_subclass {
	IAX_COMMAND_NEW =       1,
	IAX_COMMAND_PING =      2,
	IAX_COMMAND_PONG =      3,
	IAX_COMMAND_ACK =       4,
	IAX_COMMAND_HANGUP =    5,
	IAX_COMMAND_REJECT =    6,
	IAX_COMMAND_ACCEPT =    7,
	IAX_COMMAND_AUTHREQ =   8,
	IAX_COMMAND_AUTHREP =   9,
	IAX_COMMAND_INVAL =     10,
	IAX_COMMAND_LAGRQ =     11,
	IAX_COMMAND_LAGRP =     12,
	/*! Registration request */
	IAX_COMMAND_REGREQ =    13,
	/*! Registration authentication required */
	IAX_COMMAND_REGAUTH =   14,
	/*! Registration accepted */
	IAX_COMMAND_REGACK =    15,
	/*! Registration rejected */
	IAX_COMMAND_REGREJ =    16,
	/*! Force release of registration */
	IAX_COMMAND_REGREL =    17,
	/*! If we receive voice before valid first voice frame, send this */
	IAX_COMMAND_VNAK =      18,
	/*! Request status of a dialplan entry */
	IAX_COMMAND_DPREQ =     19,
	/*! Request status of a dialplan entry */
	IAX_COMMAND_DPREP =     20,
	/*! Request a dial on channel brought up TBD */
	IAX_COMMAND_DIAL =      21,
	/*! Transfer Request */
	IAX_COMMAND_TXREQ =     22,
	/*! Transfer Connect */
	IAX_COMMAND_TXCNT =     23,
	/*! Transfer Accepted */
	IAX_COMMAND_TXACC =     24,
	/*! Transfer ready */
	IAX_COMMAND_TXREADY =   25,
	/*! Transfer release */
	IAX_COMMAND_TXREL =     26,
	/*! Transfer reject */
	IAX_COMMAND_TXREJ =     27,
	/*! Stop audio/video transmission */
	IAX_COMMAND_QUELCH =    28,
	/*! Resume audio/video transmission */
	IAX_COMMAND_UNQUELCH =  29,
	/*! Like ping, but does not require an open connection */
	IAX_COMMAND_POKE =      30,
	/*! Paging description */
	IAX_COMMAND_PAGE =      31,
	/*! Stand-alone message waiting indicator */
	IAX_COMMAND_MWI =       32,
	/*! Unsupported message received */
	IAX_COMMAND_UNSUPPORT = 33,
	/*! Request remote transfer */
	IAX_COMMAND_TRANSFER =  34,
	/*! Provision device */
	IAX_COMMAND_PROVISION = 35,
	/*! Download firmware */
	IAX_COMMAND_FWDOWNL =   36,
	/*! Firmware Data */
	IAX_COMMAND_FWDATA =    37,
	/*! Transfer media only */
	IAX_COMMAND_TXMEDIA =   38,
	/*! Command to rotate key */
	IAX_COMMAND_RTKEY =     39,
	/*! Call number token */
	IAX_COMMAND_CALLTOKEN = 40,
};

/*! By default require re-registration once per minute */
#define IAX_DEFAULT_REG_EXPIRE  60

/*! How long to wait before closing bridged call */
#define IAX_LINGER_TIMEOUT		10

#define IAX_DEFAULT_PORTNO		4569

/*! IAX Information elements */
#define IAX_IE_CALLED_NUMBER		1		/*!< Number/extension being called - string */
#define IAX_IE_CALLING_NUMBER		2		/*!< Calling number - string */
#define IAX_IE_CALLING_ANI			3		/*!< Calling number ANI for billing  - string */
#define IAX_IE_CALLING_NAME			4		/*!< Name of caller - string */
#define IAX_IE_CALLED_CONTEXT		5		/*!< Context for number - string */
#define IAX_IE_USERNAME				6		/*!< Username (peer or user) for authentication - string */
#define IAX_IE_PASSWORD				7		/*!< Password for authentication - string */
#define IAX_IE_CAPABILITY			8		/*!< Actual codec capability - unsigned int */
#define IAX_IE_FORMAT				9		/*!< Desired codec format - unsigned int */
#define IAX_IE_LANGUAGE				10		/*!< Desired language - string */
#define IAX_IE_VERSION				11		/*!< Protocol version - short */
#define IAX_IE_ADSICPE				12		/*!< CPE ADSI capability - short */
#define IAX_IE_DNID					13		/*!< Originally dialed DNID - string */
#define IAX_IE_AUTHMETHODS			14		/*!< Authentication method(s) - short */
#define IAX_IE_CHALLENGE			15		/*!< Challenge data for MD5/RSA - string */
#define IAX_IE_MD5_RESULT			16		/*!< MD5 challenge result - string */
#define IAX_IE_RSA_RESULT			17		/*!< RSA challenge result - string */
#define IAX_IE_APPARENT_ADDR		18		/*!< Apparent address of peer - struct sockaddr_in */
#define IAX_IE_REFRESH				19		/*!< When to refresh registration - short */
#define IAX_IE_DPSTATUS				20		/*!< Dialplan status - short */
#define IAX_IE_CALLNO				21		/*!< Call number of peer - short */
#define IAX_IE_CAUSE				22		/*!< Cause - string */
#define IAX_IE_IAX_UNKNOWN			23		/*!< Unknown IAX command - byte */
#define IAX_IE_MSGCOUNT				24		/*!< How many messages waiting - short */
#define IAX_IE_AUTOANSWER			25		/*!< Request auto-answering -- none */
#define IAX_IE_MUSICONHOLD			26		/*!< Request musiconhold with QUELCH -- none or string */
#define IAX_IE_TRANSFERID			27		/*!< Transfer Request Identifier -- int */
#define IAX_IE_RDNIS				28		/*!< Referring DNIS -- string */
#define IAX_IE_PROVISIONING			29		/*!< Provisioning info */
#define IAX_IE_AESPROVISIONING		30		/*!< AES Provisioning info */
#define IAX_IE_DATETIME				31		/*!< Date/Time */
#define IAX_IE_DEVICETYPE			32		/*!< Device Type -- string */
#define IAX_IE_SERVICEIDENT			33		/*!< Service Identifier -- string */
#define IAX_IE_FIRMWAREVER			34		/*!< Firmware revision -- u16 */
#define IAX_IE_FWBLOCKDESC			35		/*!< Firmware block description -- u32 */
#define IAX_IE_FWBLOCKDATA			36		/*!< Firmware block of data -- raw */
#define IAX_IE_PROVVER				37		/*!< Provisioning Version (u32) */
#define IAX_IE_CALLINGPRES			38		/*!< Calling presentation (u8) */
#define IAX_IE_CALLINGTON			39		/*!< Calling type of number (u8) */
#define IAX_IE_CALLINGTNS			40		/*!< Calling transit network select (u16) */
#define IAX_IE_SAMPLINGRATE			41		/*!< Supported sampling rates (u16) */
#define IAX_IE_CAUSECODE			42		/*!< Hangup cause (u8) */
#define IAX_IE_ENCRYPTION			43		/*!< Encryption format (u16) */
#define IAX_IE_ENCKEY				44		/*!< Encryption key (raw) */
#define IAX_IE_CODEC_PREFS          45      /*!< Codec Negotiation */

#define IAX_IE_RR_JITTER			46		/*!< Received jitter (as in RFC1889) u32 */
#define IAX_IE_RR_LOSS				47		/*!< Received loss (high byte loss pct, low 24 bits loss count, as in rfc1889 */
#define IAX_IE_RR_PKTS				48		/*!< Received frames (total frames received) u32 */
#define IAX_IE_RR_DELAY				49		/*!< Max playout delay for received frames (in ms) u16 */
#define IAX_IE_RR_DROPPED			50		/*!< Dropped frames (presumably by jitterbuf) u32 */
#define IAX_IE_RR_OOO				51		/*!< Frames received Out of Order u32 */
#define IAX_IE_VARIABLE				52		/*!< Remote variables */
#define IAX_IE_OSPTOKEN				53		/*!< OSP token */
#define IAX_IE_CALLTOKEN			54		/*!< Call number security token */

#define IAX_MAX_OSPBLOCK_SIZE		254		/*!< Max OSP token block size, 255 bytes - 1 byte OSP token block index */
#define IAX_MAX_OSPBLOCK_NUM		4
#define IAX_MAX_OSPTOKEN_SIZE		(IAX_MAX_OSPBLOCK_SIZE * IAX_MAX_OSPBLOCK_NUM)
#define IAX_MAX_OSPBUFF_SIZE		(IAX_MAX_OSPTOKEN_SIZE + 16)

#define IAX_AUTH_PLAINTEXT			(1 << 0)
#define IAX_AUTH_MD5				(1 << 1)
#define IAX_AUTH_RSA				(1 << 2)

#define IAX_ENCRYPT_AES128			(1 << 0)
#define IAX_ENCRYPT_KEYROTATE			(1 << 15)       /*!< Keyrotation support */

#define IAX_META_TRUNK				1		/*!< Trunk meta-message */
#define IAX_META_VIDEO				2		/*!< Video frame */

#define IAX_META_TRUNK_SUPERMINI		0	/*!< This trunk frame contains classic supermini frames */
#define IAX_META_TRUNK_MINI			1	/*!< This trunk frame contains trunked mini frames */

#define IAX_RATE_8KHZ				(1 << 0) /*!< 8khz sampling (default if absent) */
#define IAX_RATE_11KHZ				(1 << 1) /*!< 11.025khz sampling */
#define IAX_RATE_16KHZ				(1 << 2) /*!< 16khz sampling */
#define IAX_RATE_22KHZ				(1 << 3) /*!< 22.05khz sampling */
#define IAX_RATE_44KHZ				(1 << 4) /*!< 44.1khz sampling */
#define IAX_RATE_48KHZ				(1 << 5) /*!< 48khz sampling */

#define IAX_DPSTATUS_EXISTS			(1 << 0)
#define IAX_DPSTATUS_CANEXIST		(1 << 1)
#define IAX_DPSTATUS_NONEXISTENT	(1 << 2)
#define IAX_DPSTATUS_IGNOREPAT		(1 << 14)
#define IAX_DPSTATUS_MATCHMORE		(1 << 15)

/*! Full frames are always delivered reliably */
struct ast_iax2_full_hdr {
	unsigned short scallno;	/*!< Source call number -- high bit must be 1 */
	unsigned short dcallno;	/*!< Destination call number -- high bit is 1 if retransmission */
	unsigned int ts;		/*!< 32-bit timestamp in milliseconds (from 1st transmission) */
	unsigned char oseqno;	/*!< Packet number (outgoing) */
	unsigned char iseqno;	/*!< Packet number (next incoming expected) */
	unsigned char type;		/*!< Frame type */
	unsigned char csub;		/*!< Compressed subclass */
	unsigned char iedata[0];
} __attribute__ ((__packed__));

/*! Full frames are always delivered reliably */
struct ast_iax2_full_enc_hdr {
	unsigned short scallno;	/*!< Source call number -- high bit must be 1 */
	unsigned short dcallno;	/*!< Destination call number -- high bit is 1 if retransmission */
	unsigned char encdata[0];
} __attribute__ ((__packed__));

/*! Mini header is used only for voice frames -- delivered unreliably */
struct ast_iax2_mini_hdr {
	unsigned short callno;	/*!< Source call number -- high bit must be 0, rest must be non-zero */
	unsigned short ts;		/*!< 16-bit Timestamp (high 16 bits from last ast_iax2_full_hdr) */
							/* Frametype implicitly VOICE_FRAME */
							/* subclass implicit from last ast_iax2_full_hdr */
	unsigned char data[0];
} __attribute__ ((__packed__));

/*! Mini header is used only for voice frames -- delivered unreliably */
struct ast_iax2_mini_enc_hdr {
	unsigned short callno;	/*!< Source call number -- high bit must be 0, rest must be non-zero */
	unsigned char encdata[0];
} __attribute__ ((__packed__));

struct ast_iax2_meta_hdr {
	unsigned short zeros;			/*!< Zeros field -- must be zero */
	unsigned char metacmd;			/*!< Meta command */
	unsigned char cmddata;			/*!< Command Data */
	unsigned char data[0];
} __attribute__ ((__packed__));

struct ast_iax2_video_hdr {
	unsigned short zeros;			/*!< Zeros field -- must be zero */
	unsigned short callno;			/*!< Video call number */
	unsigned short ts;				/*!< Timestamp and mark if present */
	unsigned char data[0];
} __attribute__ ((__packed__));

struct ast_iax2_meta_trunk_hdr {
	unsigned int ts;				/*!< 32-bit timestamp for all messages */
	unsigned char data[0];
} __attribute__ ((__packed__));

struct ast_iax2_meta_trunk_entry {
	unsigned short callno;			/*!< Call number */
	unsigned short len;				/*!< Length of data for this callno */
} __attribute__ ((__packed__));

/*! When trunktimestamps are used, we use this format instead */
struct ast_iax2_meta_trunk_mini {
	unsigned short len;
	struct ast_iax2_mini_hdr mini;		/*!< this is an actual miniframe */
} __attribute__ ((__packed__));

#define IAX_FIRMWARE_MAGIC 0x69617879

struct ast_iax2_firmware_header {
	unsigned int magic;		/*!< Magic number */
	unsigned short version;		/*!< Software version */
	unsigned char devname[16];	/*!< Device */
	unsigned int datalen;		/*!< Data length of file beyond header */
	unsigned char chksum[16];	/*!< Checksum of all data */
	unsigned char data[0];
} __attribute__ ((__packed__));
#endif