/*
 * This file is part of the Nice GLib ICE library.
 *
 * (C) 2008-2009 Collabora Ltd.
 *  Contact: Youness Alaoui
 * (C) 2008-2009 Nokia Corporation. All rights reserved.
 *  Contact: Rémi Denis-Courmont
 *
 * 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 the Nice GLib ICE library.
 *
 * The Initial Developers of the Original Code are Collabora Ltd and Nokia
 * Corporation. All Rights Reserved.
 *
 * Contributors:
 *   Youness Alaoui, Collabora Ltd.
 *   Rémi Denis-Courmont, Nokia
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * the GNU Lesser General Public License Version 2.1 (the "LGPL"), in which
 * case the provisions of LGPL are applicable instead of those above. If you
 * wish to allow use of your version of this file only under the terms of the
 * LGPL and not to allow others to use your version of this file under the
 * MPL, indicate your decision by deleting the provisions above and replace
 * them with the notice and other provisions required by the LGPL. If you do
 * not delete the provisions above, a recipient may use your version of this
 * file under either the MPL or the LGPL.
 */

#ifndef _STUN_MESSAGE_H
#define _STUN_MESSAGE_H


/**
 * SECTION:stunmessage
 * @short_description: STUN messages parsing and formatting functions
 * @include: stun/stunmessage.h
 * @see_also: #StunAgent
 * @stability: Stable
 *
 * The STUN Messages API allows you to create STUN messages easily as well as to
 * parse existing messages.
 *
 */


#ifdef _WIN32
#include "win32_common.h"
#else
#include <stdint.h>
#include <stdbool.h>
#endif

#include <sys/types.h>

#ifdef _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#else
#include <sys/socket.h>
#include <arpa/inet.h>
#endif

#include "constants.h"

typedef struct _StunMessage StunMessage;

/**
 * StunClass:
 * @STUN_REQUEST: A STUN Request message
 * @STUN_INDICATION: A STUN indication message
 * @STUN_RESPONSE: A STUN Response message
 * @STUN_ERROR: A STUN Error message
 *
 * This enum is used to represent the class of
 * a STUN message, as defined in RFC5389
 */

/* Message classes */
typedef enum
{
  STUN_REQUEST=0,
  STUN_INDICATION=1,
  STUN_RESPONSE=2,
  STUN_ERROR=3
} StunClass;


/**
 * StunMethod:
 * @STUN_BINDING: The Binding method as defined by the RFC5389
 * @STUN_SHARED_SECRET: The Shared-Secret method as defined by the RFC3489
 * @STUN_ALLOCATE: The Allocate method as defined by the TURN draft 12
 * @STUN_SET_ACTIVE_DST: The Set-Active-Destination method as defined by
 * the TURN draft 4
 * @STUN_REFRESH: The Refresh method as defined by the TURN draft 12
 * @STUN_SEND: The Send method as defined by the TURN draft 00
 * @STUN_CONNECT: The Connect method as defined by the TURN draft 4
 * @STUN_OLD_SET_ACTIVE_DST: The older Set-Active-Destination method as
 * defined by the TURN draft 0
 * @STUN_IND_SEND: The Send method used in indication messages as defined
 * by the TURN draft 12
 * @STUN_IND_DATA: The Data method used in indication messages as defined
 * by the TURN draft 12
 * @STUN_IND_CONNECT_STATUS:  The Connect-Status method used in indication
 * messages as defined by the TURN draft 4
 * @STUN_CREATEPERMISSION: The CreatePermission method as defined by
 * the TURN draft 12
 * @STUN_CHANNELBIND: The ChannelBind method as defined by the TURN draft 12
 *
 * This enum is used to represent the method of
 * a STUN message, as defined by various RFCs
 */
/* Message methods */
typedef enum
{
  STUN_BINDING=0x001,    /* RFC5389 */
  STUN_SHARED_SECRET=0x002,  /* old RFC3489 */
  STUN_ALLOCATE=0x003,    /* TURN-12 */
  STUN_SET_ACTIVE_DST=0x004,  /* TURN-04 */
  STUN_REFRESH=0x004,  /* TURN-12 */
  STUN_SEND=0x004,  /* TURN-00 */
  STUN_CONNECT=0x005,    /* TURN-04 */
  STUN_OLD_SET_ACTIVE_DST=0x006,  /* TURN-00 */
  STUN_IND_SEND=0x006,    /* TURN-12 */
  STUN_IND_DATA=0x007,    /* TURN-12 */
  STUN_IND_CONNECT_STATUS=0x008,  /* TURN-04 */
  STUN_CREATEPERMISSION= 0x008, /* TURN-12 */
  STUN_CHANNELBIND= 0x009 /* TURN-12 */
} StunMethod;

/**
 * StunAttribute:
 * @STUN_ATTRIBUTE_MAPPED_ADDRESS: The MAPPED-ADDRESS attribute as defined
 * by RFC5389
 * @STUN_ATTRIBUTE_RESPONSE_ADDRESS: The RESPONSE-ADDRESS attribute as defined
 * by RFC3489
 * @STUN_ATTRIBUTE_CHANGE_REQUEST: The CHANGE-REQUEST attribute as defined by
 * RFC3489
 * @STUN_ATTRIBUTE_SOURCE_ADDRESS: The SOURCE-ADDRESS attribute as defined by
 * RFC3489
 * @STUN_ATTRIBUTE_CHANGED_ADDRESS: The CHANGED-ADDRESS attribute as defined
 * by RFC3489
 * @STUN_ATTRIBUTE_USERNAME: The USERNAME attribute as defined by RFC5389
 * @STUN_ATTRIBUTE_PASSWORD: The PASSWORD attribute as defined by RFC3489
 * @STUN_ATTRIBUTE_MESSAGE_INTEGRITY: The MESSAGE-INTEGRITY attribute as defined
 * by RFC5389
 * @STUN_ATTRIBUTE_ERROR_CODE: The ERROR-CODE attribute as defined by RFC5389
 * @STUN_ATTRIBUTE_UNKNOWN_ATTRIBUTES: The UNKNOWN-ATTRIBUTES attribute as
 * defined by RFC5389
 * @STUN_ATTRIBUTE_REFLECTED_FROM: The REFLECTED-FROM attribute as defined
 * by RFC3489
 * @STUN_ATTRIBUTE_CHANNEL_NUMBER: The CHANNEL-NUMBER attribute as defined by
 * TURN draft 09 and 12
 * @STUN_ATTRIBUTE_LIFETIME: The LIFETIME attribute as defined by TURN
 * draft 04, 09 and 12
 * @STUN_ATTRIBUTE_MAGIC_COOKIE: The MAGIC-COOKIE attribute as defined by
 * the rosenberg-midcom TURN draft 08
 * @STUN_ATTRIBUTE_BANDWIDTH: The BANDWIDTH attribute as defined by TURN draft 04
 * @STUN_ATTRIBUTE_DESTINATION_ADDRESS: The DESTINATION-ADDRESS attribute as
 * defined by the rosenberg-midcom TURN draft 08
 * @STUN_ATTRIBUTE_REMOTE_ADDRESS: The REMOTE-ADDRESS attribute as defined by
 * TURN draft 04
 * @STUN_ATTRIBUTE_PEER_ADDRESS: The PEER-ADDRESS attribute as defined by
 * TURN draft 09
 * @STUN_ATTRIBUTE_XOR_PEER_ADDRESS: The XOR-PEER-ADDRESS attribute as defined
 * by TURN draft 12
 * @STUN_ATTRIBUTE_DATA: The DATA attribute as defined by TURN draft 04,
 * 09 and 12
 * @STUN_ATTRIBUTE_REALM: The REALM attribute as defined by RFC5389
 * @STUN_ATTRIBUTE_NONCE: The NONCE attribute as defined by RFC5389
 * @STUN_ATTRIBUTE_RELAY_ADDRESS: The RELAY-ADDRESS attribute as defined by
 * TURN draft 04
 * @STUN_ATTRIBUTE_RELAYED_ADDRESS: The RELAYED-ADDRESS attribute as defined by
 * TURN draft 09
 * @STUN_ATTRIBUTE_XOR_RELAYED_ADDRESS: The XOR-RELAYED-ADDRESS attribute as
 * defined by TURN draft 12
 * @STUN_ATTRIBUTE_REQUESTED_ADDRESS_TYPE: The REQUESTED-ADDRESS-TYPE attribute
 * as defined by TURN-IPV6 draft 05
 * @STUN_ATTRIBUTE_REQUESTED_PORT_PROPS: The REQUESTED-PORT-PROPS attribute
 * as defined by TURN draft 04
 * @STUN_ATTRIBUTE_REQUESTED_PROPS: The REQUESTED-PROPS attribute as defined
 * by TURN draft 09
 * @STUN_ATTRIBUTE_EVEN_PORT: The EVEN-PORT attribute as defined by TURN draft 12
 * @STUN_ATTRIBUTE_REQUESTED_TRANSPORT: The REQUESTED-TRANSPORT attribute as
 * defined by TURN draft 12
 * @STUN_ATTRIBUTE_DONT_FRAGMENT: The DONT-FRAGMENT attribute as defined
 * by TURN draft 12
 * @STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS: The XOR-MAPPED-ADDRESS attribute as
 * defined by RFC5389
 * @STUN_ATTRIBUTE_TIMER_VAL: The TIMER-VAL attribute as defined by TURN draft 04
 * @STUN_ATTRIBUTE_REQUESTED_IP: The REQUESTED-IP attribute as defined by
 * TURN draft 04
 * @STUN_ATTRIBUTE_RESERVATION_TOKEN: The RESERVATION-TOKEN attribute as defined
 * by TURN draft 09 and 12
 * @STUN_ATTRIBUTE_CONNECT_STAT: The CONNECT-STAT attribute as defined by TURN
 * draft 04
 * @STUN_ATTRIBUTE_PRIORITY: The PRIORITY attribute as defined by ICE draft 19
 * @STUN_ATTRIBUTE_USE_CANDIDATE: The USE-CANDIDATE attribute as defined by
 * ICE draft 19
 * @STUN_ATTRIBUTE_OPTIONS: The OPTIONS optional attribute as defined by
 * libjingle
 * @STUN_ATTRIBUTE_MS_VERSION: The MS-VERSION optional attribute as defined
 * by [MS-TURN]
 * @STUN_ATTRIBUTE_SOFTWARE: The SOFTWARE optional attribute as defined by RFC5389
 * @STUN_ATTRIBUTE_ALTERNATE_SERVER: The ALTERNATE-SERVER optional attribute as
 * defined by RFC5389
 * @STUN_ATTRIBUTE_FINGERPRINT: The FINGERPRINT optional attribute as defined
 * by RFC5389
 * @STUN_ATTRIBUTE_ICE_CONTROLLED: The ICE-CONTROLLED optional attribute as
 * defined by ICE draft 19
 * @STUN_ATTRIBUTE_ICE_CONTROLLING: The ICE-CONTROLLING optional attribute as
 * defined by ICE draft 19
 * @STUN_ATTRIBUTE_MS_SEQUENCE_NUMBER: The MS-SEQUENCE NUMBER optional attribute
 * as defined by [MS-TURN]
 * @STUN_ATTRIBUTE_CANDIDATE_IDENTIFIER: The CANDIDATE-IDENTIFIER optional
 * attribute as defined by [MS-ICE2]
 *
 * Known STUN attribute types as defined by various RFCs and drafts
 */
/* Should be in sync with stun_is_unknown() */
typedef enum
{
  /* Mandatory attributes */
  /* 0x0000 */        /* reserved */
  STUN_ATTRIBUTE_MAPPED_ADDRESS=0x0001,    /* RFC5389 */
  STUN_ATTRIBUTE_RESPONSE_ADDRESS=0x0002,  /* old RFC3489 */
  STUN_ATTRIBUTE_CHANGE_REQUEST=0x0003,    /* old RFC3489 */
  STUN_ATTRIBUTE_SOURCE_ADDRESS=0x0004,    /* old RFC3489 */
  STUN_ATTRIBUTE_CHANGED_ADDRESS=0x0005,  /* old RFC3489 */
  STUN_ATTRIBUTE_USERNAME=0x0006,      /* RFC5389 */
  STUN_ATTRIBUTE_PASSWORD=0x0007,    /* old RFC3489 */
  STUN_ATTRIBUTE_MESSAGE_INTEGRITY=0x0008,    /* RFC5389 */
  STUN_ATTRIBUTE_ERROR_CODE=0x0009,      /* RFC5389 */
  STUN_ATTRIBUTE_UNKNOWN_ATTRIBUTES=0x000A,    /* RFC5389 */
  STUN_ATTRIBUTE_REFLECTED_FROM=0x000B,    /* old RFC3489 */
  STUN_ATTRIBUTE_CHANNEL_NUMBER=0x000C,        /* TURN-12 */
  STUN_ATTRIBUTE_LIFETIME=0x000D,      /* TURN-12 */
  /* MS_ALTERNATE_SERVER is only used by Microsoft's dialect, probably should
   * not to be placed in STUN_ALL_KNOWN_ATTRIBUTES */
  STUN_ATTRIBUTE_MS_ALTERNATE_SERVER=0x000E, /* MS-TURN */
  STUN_ATTRIBUTE_MAGIC_COOKIE=0x000F,        /* midcom-TURN 08 */
  STUN_ATTRIBUTE_BANDWIDTH=0x0010,      /* TURN-04 */
  STUN_ATTRIBUTE_DESTINATION_ADDRESS=0x0011,        /* midcom-TURN 08 */
  STUN_ATTRIBUTE_REMOTE_ADDRESS=0x0012,    /* TURN-04 */
  STUN_ATTRIBUTE_PEER_ADDRESS=0x0012,    /* TURN-09 */
  STUN_ATTRIBUTE_XOR_PEER_ADDRESS=0x0012,    /* TURN-12 */
  STUN_ATTRIBUTE_DATA=0x0013,      /* TURN-12 */
  STUN_ATTRIBUTE_REALM=0x0014,      /* RFC5389 */
  STUN_ATTRIBUTE_NONCE=0x0015,      /* RFC5389 */
  STUN_ATTRIBUTE_RELAY_ADDRESS=0x0016,    /* TURN-04 */
  STUN_ATTRIBUTE_RELAYED_ADDRESS=0x0016,    /* TURN-09 */
  STUN_ATTRIBUTE_XOR_RELAYED_ADDRESS=0x0016,    /* TURN-12 */
  STUN_ATTRIBUTE_REQUESTED_ADDRESS_TYPE=0x0017,  /* TURN-IPv6-05 */
  STUN_ATTRIBUTE_REQUESTED_PORT_PROPS=0x0018,  /* TURN-04 */
  STUN_ATTRIBUTE_REQUESTED_PROPS=0x0018,  /* TURN-09 */
  STUN_ATTRIBUTE_EVEN_PORT=0x0018,  /* TURN-12 */
  STUN_ATTRIBUTE_REQUESTED_TRANSPORT=0x0019,  /* TURN-12 */
  STUN_ATTRIBUTE_DONT_FRAGMENT=0x001A,  /* TURN-12 */
  /* 0x001B */        /* reserved */
  /* 0x001C */        /* reserved */
  /* 0x001D */        /* reserved */
  /* 0x001E */        /* reserved */
  /* 0x001F */        /* reserved */
  STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS=0x0020,    /* RFC5389 */
  STUN_ATTRIBUTE_TIMER_VAL=0x0021,      /* TURN-04 */
  STUN_ATTRIBUTE_REQUESTED_IP=0x0022,    /* TURN-04 */
  STUN_ATTRIBUTE_RESERVATION_TOKEN=0x0022,    /* TURN-09 */
  STUN_ATTRIBUTE_CONNECT_STAT=0x0023,    /* TURN-04 */
  STUN_ATTRIBUTE_PRIORITY=0x0024,      /* ICE-19 */
  STUN_ATTRIBUTE_USE_CANDIDATE=0x0025,    /* ICE-19 */
  /* 0x0026 */        /* reserved */
  /* 0x0027 */        /* reserved */
  /* 0x0028 */        /* reserved */
  /* 0x0029 */        /* reserved */
  /* 0x002A-0x7fff */      /* reserved */

  /* Optional attributes */
  /* 0x8000-0x8021 */      /* reserved */
  STUN_ATTRIBUTE_OPTIONS=0x8001, /* libjingle */
  STUN_ATTRIBUTE_MS_VERSION=0x8008,    /* MS-TURN */
  STUN_ATTRIBUTE_SOFTWARE=0x8022,      /* RFC5389 */
  STUN_ATTRIBUTE_ALTERNATE_SERVER=0x8023,    /* RFC5389 */
  /* 0x8024 */        /* reserved */
  /* 0x8025 */        /* reserved */
  /* 0x8026 */        /* reserved */
  /* 0x8027 */        /* reserved */
  STUN_ATTRIBUTE_FINGERPRINT=0x8028,    /* RFC5389 */
  STUN_ATTRIBUTE_ICE_CONTROLLED=0x8029,    /* ICE-19 */
  STUN_ATTRIBUTE_ICE_CONTROLLING=0x802A,    /* ICE-19 */
  /* 0x802B-0x804F */      /* reserved */
  STUN_ATTRIBUTE_MS_SEQUENCE_NUMBER=0x8050,     /* MS-TURN */
  /* 0x8051-0x8053 */      /* reserved */
  STUN_ATTRIBUTE_CANDIDATE_IDENTIFIER=0x8054    /* MS-ICE2 */
  /* 0x8055-0xFFFF */      /* reserved */
} StunAttribute;


/**
 * STUN_ALL_KNOWN_ATTRIBUTES:
 *
 * An array containing all the currently known and defined mandatory attributes
 * from StunAttribute
 */
/* Should be in sync with StunAttribute */
static const uint16_t STUN_ALL_KNOWN_ATTRIBUTES[] =
  {
    STUN_ATTRIBUTE_MAPPED_ADDRESS,
    STUN_ATTRIBUTE_RESPONSE_ADDRESS,
    STUN_ATTRIBUTE_CHANGE_REQUEST,
    STUN_ATTRIBUTE_SOURCE_ADDRESS,
    STUN_ATTRIBUTE_CHANGED_ADDRESS,
    STUN_ATTRIBUTE_USERNAME,
    STUN_ATTRIBUTE_PASSWORD,
    STUN_ATTRIBUTE_MESSAGE_INTEGRITY,
    STUN_ATTRIBUTE_ERROR_CODE,
    STUN_ATTRIBUTE_UNKNOWN_ATTRIBUTES,
    STUN_ATTRIBUTE_REFLECTED_FROM,
    STUN_ATTRIBUTE_CHANNEL_NUMBER,
    STUN_ATTRIBUTE_LIFETIME,
    STUN_ATTRIBUTE_MAGIC_COOKIE,
    STUN_ATTRIBUTE_BANDWIDTH,
    STUN_ATTRIBUTE_DESTINATION_ADDRESS,
    STUN_ATTRIBUTE_REMOTE_ADDRESS,
    STUN_ATTRIBUTE_PEER_ADDRESS,
    STUN_ATTRIBUTE_XOR_PEER_ADDRESS,
    STUN_ATTRIBUTE_DATA,
    STUN_ATTRIBUTE_REALM,
    STUN_ATTRIBUTE_NONCE,
    STUN_ATTRIBUTE_RELAY_ADDRESS,
    STUN_ATTRIBUTE_RELAYED_ADDRESS,
    STUN_ATTRIBUTE_XOR_RELAYED_ADDRESS,
    STUN_ATTRIBUTE_REQUESTED_ADDRESS_TYPE,
    STUN_ATTRIBUTE_REQUESTED_PORT_PROPS,
    STUN_ATTRIBUTE_REQUESTED_PROPS,
    STUN_ATTRIBUTE_EVEN_PORT,
    STUN_ATTRIBUTE_REQUESTED_TRANSPORT,
    STUN_ATTRIBUTE_DONT_FRAGMENT,
    STUN_ATTRIBUTE_XOR_MAPPED_ADDRESS,
    STUN_ATTRIBUTE_TIMER_VAL,
    STUN_ATTRIBUTE_REQUESTED_IP,
    STUN_ATTRIBUTE_RESERVATION_TOKEN,
    STUN_ATTRIBUTE_CONNECT_STAT,
    STUN_ATTRIBUTE_PRIORITY,
    STUN_ATTRIBUTE_USE_CANDIDATE,
    0
  };

/**
 * STUN_MSOC_KNOWN_ATTRIBUTES:
 *
 * An array containing all the currently known mandatory attributes used by
 * Microsoft Office Communicator as defined in [MS-TURN]
 */
static const uint16_t STUN_MSOC_KNOWN_ATTRIBUTES[] =
  {
    STUN_ATTRIBUTE_MAPPED_ADDRESS,
    STUN_ATTRIBUTE_USERNAME,
    STUN_ATTRIBUTE_MESSAGE_INTEGRITY,
    STUN_ATTRIBUTE_ERROR_CODE,
    STUN_ATTRIBUTE_UNKNOWN_ATTRIBUTES,
    STUN_ATTRIBUTE_LIFETIME,
    STUN_ATTRIBUTE_MS_ALTERNATE_SERVER,
    STUN_ATTRIBUTE_MAGIC_COOKIE,
    STUN_ATTRIBUTE_BANDWIDTH,
    STUN_ATTRIBUTE_DESTINATION_ADDRESS,
    STUN_ATTRIBUTE_REMOTE_ADDRESS,
    STUN_ATTRIBUTE_DATA,
    /* REALM and NONCE have swapped hexadecimal IDs in [MS-TURN]. Libnice users
     * or developers can still use these enumeration values in their original
     * meanings from StunAttribute anywhere in the code, as stun_message_find()
     * and stun_message_append() will choose correct ID in MSOC compatibility
     * modes. */
    STUN_ATTRIBUTE_NONCE,
    STUN_ATTRIBUTE_REALM,
    0
  };

/**
 * StunTransactionId:
 *
 * A type that holds a STUN transaction id.
 */
typedef uint8_t StunTransactionId[STUN_MESSAGE_TRANS_ID_LEN];


/**
 * StunError:
 * @STUN_ERROR_TRY_ALTERNATE: The ERROR-CODE value for the
 * "Try Alternate" error as defined in RFC5389
 * @STUN_ERROR_BAD_REQUEST: The ERROR-CODE value for the
 * "Bad Request" error as defined in RFC5389
 * @STUN_ERROR_UNAUTHORIZED: The ERROR-CODE value for the
 * "Unauthorized" error as defined in RFC5389
 * @STUN_ERROR_UNKNOWN_ATTRIBUTE: The ERROR-CODE value for the
 * "Unknown Attribute" error as defined in RFC5389
 * @STUN_ERROR_ALLOCATION_MISMATCH:The ERROR-CODE value for the
 * "Allocation Mismatch" error as defined in TURN draft 12.
 * Equivalent to the "No Binding" error defined in TURN draft 04.
 * @STUN_ERROR_STALE_NONCE: The ERROR-CODE value for the
 * "Stale Nonce" error as defined in RFC5389
 * @STUN_ERROR_ACT_DST_ALREADY: The ERROR-CODE value for the
 * "Active Destination Already Set" error as defined in TURN draft 04.
 * @STUN_ERROR_UNSUPPORTED_FAMILY: The ERROR-CODE value for the
 * "Address Family not Supported" error as defined in TURN IPV6 Draft 05.
 * @STUN_ERROR_WRONG_CREDENTIALS: The ERROR-CODE value for the
 * "Wrong Credentials" error as defined in TURN Draft 12.
 * @STUN_ERROR_UNSUPPORTED_TRANSPORT:he ERROR-CODE value for the
 * "Unsupported Transport Protocol" error as defined in TURN Draft 12.
 * @STUN_ERROR_INVALID_IP: The ERROR-CODE value for the
 * "Invalid IP Address" error as defined in TURN draft 04.
 * @STUN_ERROR_INVALID_PORT: The ERROR-CODE value for the
 * "Invalid Port" error as defined in TURN draft 04.
 * @STUN_ERROR_OP_TCP_ONLY: The ERROR-CODE value for the
 * "Operation for TCP Only" error as defined in TURN draft 04.
 * @STUN_ERROR_CONN_ALREADY: The ERROR-CODE value for the
 * "Connection Already Exists" error as defined in TURN draft 04.
 * @STUN_ERROR_ALLOCATION_QUOTA_REACHED: The ERROR-CODE value for the
 * "Allocation Quota Reached" error as defined in TURN draft 12.
 * @STUN_ERROR_ROLE_CONFLICT:The ERROR-CODE value for the
 * "Role Conflict" error as defined in ICE draft 19.
 * @STUN_ERROR_SERVER_ERROR: The ERROR-CODE value for the
 * "Server Error" error as defined in RFC5389
 * @STUN_ERROR_SERVER_CAPACITY: The ERROR-CODE value for the
 * "Insufficient Capacity" error as defined in TURN draft 04.
 * @STUN_ERROR_INSUFFICIENT_CAPACITY: The ERROR-CODE value for the
 * "Insufficient Capacity" error as defined in TURN draft 12.
 * @STUN_ERROR_MAX: The maximum possible ERROR-CODE value as defined by RFC 5389.
 *
 * STUN error codes as defined by various RFCs and drafts
 */
/* Should be in sync with stun_strerror() */
typedef enum
{
  STUN_ERROR_TRY_ALTERNATE=300,      /* RFC5389 */
  STUN_ERROR_BAD_REQUEST=400,      /* RFC5389 */
  STUN_ERROR_UNAUTHORIZED=401,      /* RFC5389 */
  STUN_ERROR_UNKNOWN_ATTRIBUTE=420,    /* RFC5389 */
  STUN_ERROR_ALLOCATION_MISMATCH=437,   /* TURN-12 */
  STUN_ERROR_STALE_NONCE=438,      /* RFC5389 */
  STUN_ERROR_ACT_DST_ALREADY=439,    /* TURN-04 */
  STUN_ERROR_UNSUPPORTED_FAMILY=440,      /* TURN-IPv6-05 */
  STUN_ERROR_WRONG_CREDENTIALS=441,    /* TURN-12 */
  STUN_ERROR_UNSUPPORTED_TRANSPORT=442,    /* TURN-12 */
  STUN_ERROR_INVALID_IP=443,      /* TURN-04 */
  STUN_ERROR_INVALID_PORT=444,      /* TURN-04 */
  STUN_ERROR_OP_TCP_ONLY=445,      /* TURN-04 */
  STUN_ERROR_CONN_ALREADY=446,      /* TURN-04 */
  STUN_ERROR_ALLOCATION_QUOTA_REACHED=486,    /* TURN-12 */
  STUN_ERROR_ROLE_CONFLICT=487,      /* ICE-19 */
  STUN_ERROR_SERVER_ERROR=500,      /* RFC5389 */
  STUN_ERROR_SERVER_CAPACITY=507,    /* TURN-04 */
  STUN_ERROR_INSUFFICIENT_CAPACITY=508,    /* TURN-12 */
  STUN_ERROR_MAX=699
} StunError;


/**
 * StunMessageReturn:
 * @STUN_MESSAGE_RETURN_SUCCESS: The operation was successful
 * @STUN_MESSAGE_RETURN_NOT_FOUND: The attribute was not found
 * @STUN_MESSAGE_RETURN_INVALID: The argument or data is invalid
 * @STUN_MESSAGE_RETURN_NOT_ENOUGH_SPACE: There is not enough space in the
 * message to append data to it, or not enough in an argument to fill it with
 * the data requested.
 * @STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS: The address in the arguments or in
 * the STUN message is not supported.
 *
 * The return value of most stun_message_* functions.
 * This enum will report on whether an operation was successful or not
 * and what error occured if any.
 */
typedef enum
{
  STUN_MESSAGE_RETURN_SUCCESS,
  STUN_MESSAGE_RETURN_NOT_FOUND,
  STUN_MESSAGE_RETURN_INVALID,
  STUN_MESSAGE_RETURN_NOT_ENOUGH_SPACE,
  STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS
} StunMessageReturn;

#include "stunagent.h"

/**
 * STUN_MAX_MESSAGE_SIZE:
 *
 * The Maximum size of a STUN message
 */
#define STUN_MAX_MESSAGE_SIZE 65552

/**
 * StunMessage:
 * @agent: The agent that created or validated this message
 * @buffer: The buffer containing the STUN message
 * @buffer_len: The length of the buffer (not the size of the message)
 * @key: The short term credentials key to use for authentication validation
 * or that was used to finalize this message
 * @key_len: The length of the associated key
 * @long_term_key: The long term credential key to use for authentication
 * validation or that was used to finalize this message
 * @long_term_valid: Whether or not the #long_term_key variable contains valid
 * data
 *
 * This structure represents a STUN message
 */
struct _StunMessage {
  StunAgent *agent;
  uint8_t *buffer;
  size_t buffer_len;
  uint8_t *key;
  size_t key_len;
  uint8_t long_term_key[16];
  bool long_term_valid;
};

/**
 * stun_message_init:
 * @msg: The #StunMessage to initialize
 * @c: STUN message class (host byte order)
 * @m: STUN message method (host byte order)
 * @id: 16-bytes transaction ID
 *
 * Initializes a STUN message buffer, with no attributes.
 * Returns: %TRUE if the initialization was successful
 */
bool stun_message_init (StunMessage *msg, StunClass c, StunMethod m,
    const StunTransactionId id);

/**
 * stun_message_length:
 * @msg: The #StunMessage
 *
 * Get the length of the message (including the header)
 *
 * Returns: The length of the message
 */
uint16_t stun_message_length (const StunMessage *msg);

/**
 * stun_message_find:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to find
 * @palen: A pointer to store the length of the attribute
 *
 * Finds an attribute in a STUN message and fetches its content
 *
 * Returns: A pointer to the start of the attribute payload if found,
 * otherwise NULL.
 */
const void * stun_message_find (const StunMessage * msg, StunAttribute type,
    uint16_t *palen);


/**
 * stun_message_find_flag:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to find
 *
 * Looks for a flag attribute within a valid STUN message.
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the attribute's size is not zero.
 */
StunMessageReturn stun_message_find_flag (const StunMessage *msg,
    StunAttribute type);

/**
 * stun_message_find32:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to find
 * @pval: A pointer where to store the value (host byte order)
 *
 * Extracts a 32-bits attribute from a STUN message.
 *
 * Returns:  A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the attribute's size is not
 * 4 bytes.
 */
StunMessageReturn stun_message_find32 (const StunMessage *msg,
    StunAttribute type, uint32_t *pval);

/**
 * stun_message_find64:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to find
 * @pval: A pointer where to store the value (host byte order)
 *
 * Extracts a 64-bits attribute from a STUN message.
 *
 * Returns:  A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the attribute's size is not
 * 8 bytes.
 */
StunMessageReturn stun_message_find64 (const StunMessage *msg,
    StunAttribute type, uint64_t *pval);

/**
 * stun_message_find_string:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to find
 * @buf: A pointer where to store the data
 * @buflen: The length of the buffer
 *
 * Extracts an UTF-8 string from a valid STUN message.
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the attribute is improperly
 * encoded
 * %STUN_MESSAGE_RETURN_NOT_ENOUGH_SPACE is return if the buffer size is too
 * small to hold the string
 *
 <note>
   <para>
    The string will be NULL-terminated.
   </para>
 </note>
 *
 */
StunMessageReturn stun_message_find_string (const StunMessage *msg,
    StunAttribute type, char *buf, size_t buflen);

/**
 * stun_message_find_addr:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to find
 * @addr: The #sockaddr to be filled
 * @addrlen: The size of the @addr variable. Must be set to the size of the
 * @addr socket address and will be set to the size of the extracted socket
 * address.
 *
 * Extracts a network address attribute from a STUN message.
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the attribute payload size is
 * wrong or if the @addrlen is too small
 * %STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS if the address family is unknown.
 */
StunMessageReturn stun_message_find_addr (const StunMessage *msg,
    StunAttribute type, struct sockaddr_storage *addr, socklen_t *addrlen);

/**
 * stun_message_find_xor_addr:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to find
 * @addr: The #sockaddr to be filled
 * @addrlen: The size of the @addr variable. Must be set to the size of the
 * @addr socket address and will be set to the size of the
 * extracted socket address.
 *
 * Extracts an obfuscated network address attribute from a STUN message.
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the attribute payload size is
 * wrong or if the @addrlen is too small
 * %STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS if the address family is unknown.
 */
StunMessageReturn stun_message_find_xor_addr (const StunMessage *msg,
    StunAttribute type, struct sockaddr_storage *addr, socklen_t *addrlen);

/**
 * stun_message_find_xor_addr_full:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to find
 * @addr: The #sockaddr to be filled
 * @addrlen: The size of the @addr variable. Must be set to the size of the
 * @addr socket address and will be set to the size of the
 * extracted socket address.
 * @magic_cookie: The magic cookie to use to XOR the address.
 *
 * Extracts an obfuscated network address attribute from a STUN message.
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the attribute payload size is
 * wrong or if the @addrlen is too small
 * %STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS if the address family is unknown.
 */
StunMessageReturn stun_message_find_xor_addr_full (const StunMessage *msg,
    StunAttribute type, struct sockaddr_storage *addr,
    socklen_t *addrlen, uint32_t magic_cookie);


/**
 * stun_message_find_error:
 * @msg: The #StunMessage
 * @code: A  pointer where to store the value
 *
 * Extract the error response code from a STUN message
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the value is invalid
 */
StunMessageReturn stun_message_find_error (const StunMessage *msg, int *code);


/**
 * stun_message_append:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 * @length: The length of the attribute
 *
 * Reserves room for appending an attribute to an unfinished STUN message.
 *
 * Returns: A pointer to an unitialized buffer of @length bytes to
 * where the attribute payload must be written, or NULL if there is not
 * enough room in the STUN message buffer.
 */
void *stun_message_append (StunMessage *msg, StunAttribute type,
    size_t length);

/**
 * stun_message_append_bytes:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 * @data: The data to append
 * @len: The length of the attribute
 *
 * Appends a binary value to a STUN message
 *
 * Returns: A #StunMessageReturn value.
 */
StunMessageReturn stun_message_append_bytes (StunMessage *msg,
    StunAttribute type, const void *data, size_t len);

/**
 * stun_message_append_flag:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 *
 * Appends an empty flag attribute to a STUN message
 *
 * Returns: A #StunMessageReturn value.
 */
StunMessageReturn stun_message_append_flag (StunMessage *msg,
    StunAttribute type);

/**
 * stun_message_append32:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 * @value: The value to append (host byte order)
 *
 * Appends a 32-bits value attribute to a STUN message
 *
 * Returns: A #StunMessageReturn value.
 */
StunMessageReturn stun_message_append32 (StunMessage *msg,
    StunAttribute type, uint32_t value);

/**
 * stun_message_append64:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 * @value: The value to append (host byte order)
 *
 * Appends a 64-bits value attribute to a STUN message
 *
 * Returns: A #StunMessageReturn value.
 */
StunMessageReturn stun_message_append64 (StunMessage *msg,
    StunAttribute type, uint64_t value);

/**
 * stun_message_append_string:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 * @str: The string to append
 *
 * Adds an attribute from a NULL-terminated string to a STUN message
 *
 * Returns: A #StunMessageReturn value.
 */
StunMessageReturn stun_message_append_string (StunMessage *msg,
    StunAttribute type, const char *str);

/**
 * stun_message_append_addr:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 * @addr: The #sockaddr to be append
 * @addrlen: The size of the @addr variable.
 *
 * Append a network address attribute to a STUN message
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the @addrlen is too small
 * %STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS if the address family is unknown.
 */
StunMessageReturn stun_message_append_addr (StunMessage * msg,
    StunAttribute type, const struct sockaddr *addr, socklen_t addrlen);

/**
 * stun_message_append_xor_addr:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 * @addr: The #sockaddr to be append
 * @addrlen: The size of the @addr variable.
 *
 * Append an obfuscated network address attribute to a STUN message
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the @addrlen is too small
 * %STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS if the address family is unknown.
 */
StunMessageReturn stun_message_append_xor_addr (StunMessage * msg,
    StunAttribute type, const struct sockaddr_storage *addr, socklen_t addrlen);

/**
 * stun_message_append_xor_addr_full:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to append
 * @addr: The #sockaddr to be append
 * @addrlen: The size of the @addr variable.
 * @magic_cookie: The magic cookie to use to XOR the address.
 *
 * Append an obfuscated network address attribute from a STUN message.
 *
 * Returns: A #StunMessageReturn value.
 * %STUN_MESSAGE_RETURN_INVALID is returned if the @addrlen is too small
 * %STUN_MESSAGE_RETURN_UNSUPPORTED_ADDRESS if the address family is unknown.
 */
StunMessageReturn stun_message_append_xor_addr_full (StunMessage * msg,
    StunAttribute type, const struct sockaddr_storage *addr, socklen_t addrlen,
    uint32_t magic_cookie);

/**
 * stun_message_append_error:
 * @msg: The #StunMessage
 * @code: The error code value
 *
 * Appends the ERROR-CODE attribute to the STUN message and fills it according
 * to #code
 *
 * Returns: A #StunMessageReturn value.
 */
StunMessageReturn stun_message_append_error (StunMessage * msg,
    StunError code);

/**
 * STUN_MESSAGE_BUFFER_INCOMPLETE:
 *
 * Convenience macro for stun_message_validate_buffer_length() meaning that the
 * data to validate does not hold a complete STUN message
 */
#define STUN_MESSAGE_BUFFER_INCOMPLETE 0

/**
 * STUN_MESSAGE_BUFFER_INVALID:
 *
 * Convenience macro for stun_message_validate_buffer_length() meaning that the
 * data to validate is not a valid STUN message
 */
#define STUN_MESSAGE_BUFFER_INVALID -1


/**
 * stun_message_validate_buffer_length:
 * @msg: The buffer to validate
 * @length: The length of the buffer
 * @has_padding: Set TRUE if attributes should be padded to multiple of 4 bytes
 *
 * This function will take a data buffer and will try to validate whether it is
 * a STUN message or if it's not or if it's an incomplete STUN message and will
 * provide us with the length of the STUN message.
 *
 * Returns: The length of the valid STUN message in the buffer.
 * <para> See also: #STUN_MESSAGE_BUFFER_INCOMPLETE </para>
 * <para> See also: #STUN_MESSAGE_BUFFER_INVALID </para>
 */
int stun_message_validate_buffer_length (const uint8_t *msg, size_t length,
    bool has_padding);

/**
 * StunInputVector:
 * @buffer: a buffer containing already-received binary data
 * @size: length of @buffer, in bytes
 *
 * Container for a single buffer which also stores its length. This is designed
 * for vectored I/O: typically an array of #StunInputVectors is passed to
 * functions, providing multiple buffers which store logically contiguous
 * received data.
 *
 * This is guaranteed to be layed out identically in memory to #GInputVector.
 *
 * Since: 0.1.5
 */
typedef struct {
  const uint8_t *buffer;
  size_t size;
} StunInputVector;

/**
 * stun_message_validate_buffer_length_fast:
 * @buffers: (array length=n_buffers) (in caller-allocated): array of contiguous
 * #StunInputVectors containing already-received message data
 * @n_buffers: number of entries in @buffers
 * @total_length: total number of valid bytes stored consecutively in @buffers
 * @has_padding: %TRUE if attributes should be padded to 4-byte boundaries
 *
 * Quickly validate whether the message in the given @buffers is potentially a
 * valid STUN message, an incomplete STUN message, or if it’s definitely not one
 * at all.
 *
 * This is designed as a first-pass validation only, and does not check the
 * message’s attributes for validity. If this function returns success, the
 * buffers can be compacted and a more thorough validation can be performed
 * using stun_message_validate_buffer_length(). If it fails, the buffers
 * definitely do not contain a complete, valid STUN message.
 *
 * Returns: The length of the valid STUN message in the buffer, or zero or -1 on
 * failure
 * <para> See also: #STUN_MESSAGE_BUFFER_INCOMPLETE </para>
 * <para> See also: #STUN_MESSAGE_BUFFER_INVALID </para>
 *
 * Since: 0.1.5
 */
ssize_t stun_message_validate_buffer_length_fast (StunInputVector *buffers,
    unsigned int n_buffers, size_t total_length, bool has_padding);

/**
 * stun_message_id:
 * @msg: The #StunMessage
 * @id: The #StunTransactionId to fill
 *
 * Retreive the STUN transaction id from a STUN message
 */
void stun_message_id (const StunMessage *msg, StunTransactionId id);

/**
 * stun_message_get_class:
 * @msg: The #StunMessage
 *
 * Retreive the STUN class from a STUN message
 *
 * Returns: The #StunClass
 */
StunClass stun_message_get_class (const StunMessage *msg);

/**
 * stun_message_get_method:
 * @msg: The #StunMessage
 *
 * Retreive the STUN method from a STUN message
 *
 * Returns: The #StunMethod
 */
StunMethod stun_message_get_method (const StunMessage *msg);

/**
 * stun_message_has_attribute:
 * @msg: The #StunMessage
 * @type: The #StunAttribute to look for
 *
 * Checks if an attribute is present within a STUN message.
 *
 * Returns: %TRUE if the attribute is found, %FALSE otherwise
 */
bool stun_message_has_attribute (const StunMessage *msg, StunAttribute type);


/* Defined in stun5389.c */
/**
 * stun_message_has_cookie:
 * @msg: The #StunMessage
 *
 * Checks if the STUN message has a RFC5389 compatible cookie
 *
 * Returns: %TRUE if the cookie is present, %FALSE otherwise
 */
bool stun_message_has_cookie (const StunMessage *msg);


/**
 * stun_optional:
 * @t: An attribute type
 *
 * Helper function that checks whether a STUN attribute is a mandatory
 * or an optional attribute
 *
 * Returns: %TRUE if the attribute is an optional one
 */
bool stun_optional (uint16_t t);

/**
 * stun_strerror:
 * @code: host-byte order error code
 *
 * Transforms a STUN error-code into a human readable string
 *
 * Returns: A static pointer to a NULL-terminated error message string.
 */
const char *stun_strerror (StunError code);


#endif /* _STUN_MESSAGE_H */