You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
asterisk/include/asterisk/sdp_state.h

346 lines
9.3 KiB

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2017, Digium, Inc.
*
* Mark Michelson <mmichelson@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
#ifndef _ASTERISK_SDP_STATE_H
#define _ASTERISK_SDP_STATE_H
#include "asterisk/stream.h"
#include "asterisk/sdp_options.h"
struct ast_sdp_state;
struct ast_sockaddr;
struct ast_udptl;
struct ast_control_t38_parameters;
/*!
* \brief Allocate a new SDP state
*
* \details
* SDP state keeps tabs on everything SDP-related for a media session.
* Most SDP operations will require the state to be provided.
* Ownership of the SDP options is taken on by the SDP state.
* A good strategy is to call this during session creation.
*
* \param topology Initial stream topology to offer.
* NULL if we are going to be the answerer. We can always
* update the local topology later if it turns out we need
* to be the offerer.
* \param options SDP options for the duration of the session.
*
* \retval SDP state struct
* \retval NULL on failure
*/
struct ast_sdp_state *ast_sdp_state_alloc(struct ast_stream_topology *topology,
struct ast_sdp_options *options);
/*!
* \brief Free the SDP state.
*
* A good strategy is to call this during session destruction
*/
void ast_sdp_state_free(struct ast_sdp_state *sdp_state);
/*!
* \brief Get the associated RTP instance for a particular stream on the SDP state.
*
* Stream numbers correspond to the streams in the topology of the associated channel
*/
struct ast_rtp_instance *ast_sdp_state_get_rtp_instance(const struct ast_sdp_state *sdp_state,
int stream_index);
/*!
* \brief Get the associated UDPTL instance for a particular stream on the SDP state.
*
* Stream numbers correspond to the streams in the topology of the associated channel
*/
struct ast_udptl *ast_sdp_state_get_udptl_instance(const struct ast_sdp_state *sdp_state,
int stream_index);
/*!
* \brief Get the global connection address on the SDP state.
*/
const struct ast_sockaddr *ast_sdp_state_get_connection_address(const struct ast_sdp_state *sdp_state);
/*!
* \brief Get the connection address for a particular stream.
*
* \param sdp_state
* \param stream_index The particular stream to get the connection address of
* \param address[out] A place to store the address in
*
* \retval 0 Success
*
* \note
* Stream numbers correspond to the streams in the topology of the associated channel
*/
int ast_sdp_state_get_stream_connection_address(const struct ast_sdp_state *sdp_state,
int stream_index, struct ast_sockaddr *address);
/*!
* \brief Get the joint negotiated streams based on local and remote capabilities.
*
* If this is called prior to receiving a remote SDP, then this will just mirror
* the local configured endpoint capabilities.
*
* \note Cannot return NULL. It is a BUG if it does.
*/
const struct ast_stream_topology *ast_sdp_state_get_joint_topology(
const struct ast_sdp_state *sdp_state);
/*!
* \brief Get the local topology
*
* \note Cannot return NULL. It is a BUG if it does.
*/
const struct ast_stream_topology *ast_sdp_state_get_local_topology(
const struct ast_sdp_state *sdp_state);
/*!
* \brief Get the sdp_state options
*
*/
const struct ast_sdp_options *ast_sdp_state_get_options(
const struct ast_sdp_state *sdp_state);
/*!
* \brief Get the local SDP.
*
* \param sdp_state
*
* \retval non-NULL Success
* \retval NULL Failure
*
* \note
* This function will return the last local SDP created if one were
* previously requested for the current negotiation. Otherwise it
* creates our SDP offer/answer depending on what role we are playing
* in the current negotiation.
*/
const struct ast_sdp *ast_sdp_state_get_local_sdp(struct ast_sdp_state *sdp_state);
/*!
* \brief Get the local SDP Implementation.
*
* \param sdp_state
*
* \retval non-NULL Success
* \retval NULL Failure
*
* \note
* This function calls ast_sdp_state_get_local_sdp then translates it into
* the defined implementation.
*
* The return here is const. The use case for this is so that a channel can add
* the SDP to an outgoing message. The API user should not attempt to modify the SDP.
* SDP modification should only be done through the API.
*
* \since 15
*/
const void *ast_sdp_state_get_local_sdp_impl(struct ast_sdp_state *sdp_state);
/*!
* \brief Set the remote SDP
*
* \param sdp_state
* \param sdp
*
* \note It is assumed that the passed in SDP has been checked for sanity
* already. e.g., There are no syntax errors, a c= line is reachable for
* each m= line, etc...
*
* \retval 0 Success
* \retval non-0 Failure
* Use ast_sdp_state_is_offer_rejected() to see if the SDP offer was rejected.
*
* \since 15
*/
int ast_sdp_state_set_remote_sdp(struct ast_sdp_state *sdp_state, const struct ast_sdp *sdp);
/*!
* \brief Set the remote SDP from an Implementation
*
* \param sdp_state
* \param remote The implementation's representation of an SDP.
*
* \retval 0 Success
* \retval non-0 Failure
* Use ast_sdp_state_is_offer_rejected() to see if the SDP offer was rejected.
*
* \since 15
*/
int ast_sdp_state_set_remote_sdp_from_impl(struct ast_sdp_state *sdp_state, const void *remote);
/*!
* \brief Was the set remote offer rejected.
* \since 15.0.0
*
* \param sdp_state
*
* \retval 0 if not rejected.
* \retval non-zero if rejected.
*/
int ast_sdp_state_is_offer_rejected(struct ast_sdp_state *sdp_state);
/*!
* \brief Are we the SDP offerer.
* \since 15.0.0
*
* \param sdp_state
*
* \retval 0 if we are not the offerer.
* \retval non-zero we are the offerer.
*/
int ast_sdp_state_is_offerer(struct ast_sdp_state *sdp_state);
/*!
* \brief Are we the SDP answerer.
* \since 15.0.0
*
* \param sdp_state
*
* \retval 0 if we are not the answerer.
* \retval non-zero we are the answerer.
*/
int ast_sdp_state_is_answerer(struct ast_sdp_state *sdp_state);
/*!
* \brief Restart the SDP offer/answer negotiations.
*
* \param sdp_state
*
* \retval 0 Success
* \retval non-0 Failure
*/
int ast_sdp_state_restart_negotiations(struct ast_sdp_state *sdp_state);
/*!
* \brief Update the local stream topology on the SDP state.
*
* \details
* Basically we are saving off any topology updates until we create the
* next SDP offer. Repeated updates merge with the previous updated
* topology.
*
* \param sdp_state
* \param topology The new stream topology.
*
* \retval 0 Success
* \retval non-0 Failure
*
* \since 15
*/
int ast_sdp_state_update_local_topology(struct ast_sdp_state *sdp_state, struct ast_stream_topology *topology);
/*!
* \brief Set the local address (IP address) to use for connection addresses
*
* \param sdp_state
* \param address The local address
*
* \note
* Passing NULL as an address will unset the explicit local connection address.
*
* \since 15
*/
void ast_sdp_state_set_local_address(struct ast_sdp_state *sdp_state, struct ast_sockaddr *address);
/*!
* \brief Set the connection address (IP address and port) to use for a specific stream
*
* \param sdp_state
* \param stream_index The stream to set the connection address for
* \param address The connection address
*
* \retval 0 Success
*
* \note
* Passing NULL as an address will unset the explicit local connection address.
*
* \since 15
*/
int ast_sdp_state_set_connection_address(struct ast_sdp_state *sdp_state, int stream_index,
struct ast_sockaddr *address);
/*!
* \since 15.0.0
* \brief Set the global locally held state.
*
* \param sdp_state
* \param locally_held
*/
void ast_sdp_state_set_global_locally_held(struct ast_sdp_state *sdp_state, unsigned int locally_held);
/*!
* \since 15.0.0
* \brief Get the global locally held state.
*
* \param sdp_state
*
* \returns locally_held
*/
unsigned int ast_sdp_state_get_global_locally_held(const struct ast_sdp_state *sdp_state);
/*!
* \since 15.0.0
* \brief Set a stream to be held or unheld locally
*
* \param sdp_state
* \param stream_index The stream to set the held value for
* \param locally_held
*/
void ast_sdp_state_set_locally_held(struct ast_sdp_state *sdp_state,
int stream_index, unsigned int locally_held);
/*!
* \since 15.0.0
* \brief Get whether a stream is locally held or not
*
* \param sdp_state
* \param stream_index The stream to get the held state for
*
* \returns locally_held
*/
unsigned int ast_sdp_state_get_locally_held(const struct ast_sdp_state *sdp_state,
int stream_index);
/*!
* \since 15.0.0
* \brief Get whether a stream is remotely held or not
*
* \param sdp_state
* \param stream_index The stream to get the held state for
*
* \returns remotely_held
*/
unsigned int ast_sdp_state_get_remotely_held(const struct ast_sdp_state *sdp_state,
int stream_index);
/*!
* \since 15.0.0
* \brief Set the UDPTL session parameters
*
* \param sdp_state
* \param stream_index The stream to set the UDPTL session parameters for
* \param params
*/
void ast_sdp_state_set_t38_parameters(struct ast_sdp_state *sdp_state,
int stream_index, struct ast_control_t38_parameters *params);
#endif /* _ASTERISK_SDP_STATE_H */