sdp.h

this is simple sip stack.

/*
 * This file is part of the Sofia-SIP package
 *
 * Copyright (C) 2005 Nokia Corporation.
 *
 * Contact: Pekka Pessi <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#ifndef SDP_H
#define SDP_H
/**@file sofia-sip/sdp.h  Simple SDP (RFC 2327) Interface.
 *
 * @author Pekka Pessi <[e-mail]>
 * @author Kai Vehmanen <[e-mail]>
 *
 * @date Created: Fri Feb 18 08:54:48 2000 ppessi
 */

#ifndef SU_ALLOC_H
#include <sofia-sip/su_alloc.h>
#endif
#ifndef SU_TYPES_H
#include <sofia-sip/su_types.h>
#endif

SOFIA_BEGIN_DECLS

/** SDP session description */
typedef struct sdp_session_s     sdp_session_t;
/** SDP version "v=" line */
typedef unsigned long            sdp_version_t;
/** SDP origin "o=" line */
typedef struct sdp_origin_s      sdp_origin_t;
/** SDP connection "c=" line */
typedef struct sdp_connection_s  sdp_connection_t;
/** SDP bandwidth "b=" line */
typedef struct sdp_bandwidth_s   sdp_bandwidth_t;
/** SDP time "t=" line */
typedef struct sdp_time_s        sdp_time_t;
/** SDP repeat "r=" line */
typedef struct sdp_repeat_s      sdp_repeat_t;
/** SDP timezone "z=" line */
typedef struct sdp_zone_s        sdp_zone_t;
/** SDP encryption key "k=" line */
typedef struct sdp_key_s         sdp_key_t;
/** SDP attribute "a=" line */
typedef struct sdp_attribute_s   sdp_attribute_t;
/** SDP media "m=" line */
typedef struct sdp_media_s       sdp_media_t;
/** SDP list ("e=", "p=" lines) */
typedef struct sdp_list_s        sdp_list_t;
/** SDP rtpmap attribute */
typedef struct sdp_rtpmap_s      sdp_rtpmap_t;

/** Message text */
typedef char const               sdp_text_t;

#define SDP_MIME_TYPE "application/sdp"

enum {
  SDP_CURRENT_VERSION = 0
};

/** Session description */
struct sdp_session_s
{
  int                sdp_size;		/**< sizeof sdp_session_t */
  sdp_session_t     *sdp_next;	        /**< Next description in list */
  sdp_version_t      sdp_version[1];	/**< SDP version */
  sdp_origin_t      *sdp_origin;	/**< Owner/creator and session ID */
  sdp_text_t        *sdp_subject;	/**< Session name */
  sdp_text_t        *sdp_information;	/**< Session information  */
  sdp_text_t        *sdp_uri;		/**< URi of description */
  sdp_list_t   	    *sdp_emails;	/**< E-mail address(s) */
  sdp_list_t   	    *sdp_phones;	/**< Phone number(s)  */
  sdp_connection_t  *sdp_connection;	/**< Group (or member) address */
  sdp_bandwidth_t   *sdp_bandwidths;	/**< Session bandwidth */
  sdp_time_t        *sdp_time;		/**< Session active time */
  sdp_key_t         *sdp_key;	        /**< Session key */
  sdp_attribute_t   *sdp_attributes;    /**< Session attributes */
  sdp_text_t        *sdp_charset;       /**< SDP charset (default is UTF8) */
  sdp_media_t       *sdp_media;         /**< Media descriptors */
};

/** Session description identification */ 
struct sdp_origin_s
{
  int               o_size;		/**< sizeof sdp_origin_t */
  sdp_text_t       *o_username;		/**< Username of originator */
  uint64_t          o_id;		/**< Session identification  */
  uint64_t          o_version;		/**< Version of session description */
  sdp_connection_t *o_address;		/**< Address of originator */
};

/** Network type */
typedef enum
{
  sdp_net_x = 0,			/**< Unknown network type */
  sdp_net_in = 1		        /**< Internet */
} sdp_nettype_e;

/** Address type */
typedef enum
{
  sdp_addr_x   = 0,			/**< Unknown address type */
  sdp_addr_ip4 = 1,			/**< IPv4 address */
  sdp_addr_ip6 = 2,			/**< IPv6 address */
} sdp_addrtype_e;

/** SDP connection - host or group address */
struct sdp_connection_s
{
  int               c_size;		/**< Size fo sdp_connection_t */
  sdp_connection_t *c_next;		/**< Next connection in list */
  sdp_nettype_e     c_nettype;		/**< Network type */
  sdp_addrtype_e    c_addrtype;		/**< Address type */
  sdp_text_t       *c_address;		/**< Host or group address */
  unsigned          c_ttl : 8;		/**< Time to live (scope) */
  unsigned          c_mcast : 1;        /**< True if multicast */
  unsigned : 0;
  unsigned          c_groups;		/**< Number of groups (if multiple) */
};

/** Bandwdith type */
typedef enum
{
  sdp_bw_x,				/**< Unknown bandwidth type */
  sdp_bw_ct,				/**< Conference total */
  sdp_bw_as,				/**< Application-specific */
} sdp_bandwidth_e;

/** Session or media bandwidth. */
struct sdp_bandwidth_s
{
  int              b_size;		/**< Size fo sdp_bandwidth_t */
  sdp_bandwidth_t *b_next;		/**< Next bw description in list */
  sdp_bandwidth_e  b_modifier;		/**< Meaning of value 
					     (total, or per application).  */
  sdp_text_t      *b_modifier_name;     /**< Modifier if not well-known */
  unsigned long    b_value;		/**< Bandwidth in kilobits per second */
};

/** Active time description. */
struct sdp_time_s
{
  int            t_size;		/**< sizeof sdp_time_t in bytes */
  sdp_time_t    *t_next;		/**< Next time description in list */
  unsigned long  t_start;		/**< Start time (seconds since 1900) */
  unsigned long  t_stop;		/**< Stop time (seconds since 1900) */
  sdp_repeat_t  *t_repeat;		/**< Repeat information */
  sdp_zone_t    *t_zone;		/**< Time Zone infromation */
};

/** Description of repetition. */
struct sdp_repeat_s
{
  int           r_size;			/**< Size of structure including
					 * r_offsets[r_number_of_offsets]
					 */
  int           r_number_of_offsets;	/**< Number of offsets in list */
  unsigned long r_interval;		/**< Time between activations */
  unsigned long r_duration;		/**< Duration of activation */
  unsigned long r_offsets[1];	        /**< List of offsets from start-time */
};

/** Timezone */
struct sdp_zone_s
{
  /** Size of structure including z_adjustments[z_number_of_adjustments] */
  int z_size;
  int z_number_of_adjustments;		/**< Number of adjustments in list  */
  struct {
    unsigned long z_at;			/**< Adjustment time  */
    long          z_offset;		/**< Adjustment offset  */
  } z_adjustments[1];		        /**< List of timezone adjustments */
};

/** Mechanism to be used to obtain session key */
typedef enum {
  sdp_key_x,				/**< Unknown mechanism */
  sdp_key_clear,			/**< Key is included untransformed */
  sdp_key_base64,			/**< Key is encoded with base64 */
  sdp_key_uri,				/**< URI used to obtain a key */
  sdp_key_prompt			/**< No key is included, 
					     prompt user for key */
} sdp_key_method_e;

/** Session key */
struct sdp_key_s
{
  int              k_size;		/**< sizeof sdp_key_t  */
  sdp_key_method_e k_method;		/**< Mechanism used to obtain key */
  sdp_text_t      *k_method_name;	/**< Mechanism if not known  */
  sdp_text_t      *k_material;		/**< Encryption key  */
};

/** Session or media attribute */
struct sdp_attribute_s {
  int              a_size;		/**< sizeof sdp_attribute_t  */
  sdp_attribute_t *a_next;		/**< Next attribute in list */
  sdp_text_t      *a_name;		/**< Attribute name */
  sdp_text_t      *a_value;		/**< Attribute value */
};

/** Media type @sa RFC2327 page 18. */
typedef enum
{
  sdp_media_x = 0,			/**< Unknown media */
  sdp_media_any,		        /**< * wildcard */
  sdp_media_audio,			/**< Audio */
  sdp_media_video,			/**< Video */
  sdp_media_application,		/**< Conferencing */
  sdp_media_data,			/**< Bulk data transfer */
  sdp_media_control,			/**< Additional conference control */
  sdp_media_message,			/**< Messaging sessions*/
  sdp_media_image			/**< Image browsing sessions for JPIP */
} sdp_media_e;

/** Media transport protocol. */
typedef enum
{
  sdp_proto_x = 0,			/**< Unknown transport  */
  sdp_proto_tcp = 6,			/**< TCP  */
  sdp_proto_udp = 17,			/**< Plain UDP */
  sdp_proto_rtp = 256,			/**< RTP/AVP */
  sdp_proto_srtp = 257,			/**< RTP/SAVP  */
  sdp_proto_tls = 511,			/**< TLS over TCP */
  sdp_proto_any = 512		        /**< * wildcard */
} sdp_proto_e;

/** Session mode. @note Identical to rtp_mode_t. */
typedef enum {
  sdp_inactive = 0, 
  sdp_sendonly = 1, 
  sdp_recvonly = 2, 
  sdp_sendrecv = sdp_sendonly | sdp_recvonly
} sdp_mode_t;

/** Media announcement.
 * 
 * This structure describes one media type, e.g., audio.  The description
 * contains the transport address (IP address and port) used for the group,
 * the transport protocol used, the media formats or RTP payload types, and
 * optionally media-specific bandwidth specification, encryption key and
 * attributes. 
 *
 * There is a pointer (m_user) for the application data, too.
 */
struct sdp_media_s
{
  int               m_size;		/**< sizeof sdp_media_t  */
  sdp_media_t      *m_next;		/**< Next media announcement  */
  sdp_session_t    *m_session;          /**< Back-pointer to session level */

  sdp_media_e       m_type;		/**< Media type  */
  sdp_text_t       *m_type_name;	/**< Media type name */
  unsigned long     m_port;		/**< Transport port number */
  unsigned long     m_number_of_ports;	/**< Number of ports (if multiple) */
  sdp_proto_e       m_proto;		/**< Transport protocol  */
  sdp_text_t       *m_proto_name;	/**< Transport protocol name */
  sdp_list_t       *m_format;		/**< List of media formats */
  sdp_rtpmap_t     *m_rtpmaps;		/**< List of RTP maps */
  sdp_text_t       *m_information;	/**< Media information */
  sdp_connection_t *m_connections;	/**< List of addresses used */