* Added additional fields to ast_sdp_options. * Re-organized ast_sdp. * Updated field names to correspond to RFC4566 terminology. * Created allocs/frees for SDP children. * Created getters/setters for SDP children where appropriate. * Added ast_sdp_create_from_state. * Refactored res_sdp_translator_pjmedia for changes. Change-Id: Iefbd877af7f5a4d3c74deead1bff8802661b0d48
264 lines
7.1 KiB
C
264 lines
7.1 KiB
C
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 2017, Digium, Inc.
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*
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* Mark Michelson <mmichelson@digium.com>
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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#include "asterisk.h"
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#include "asterisk/sdp_state.h"
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#include "asterisk/sdp_options.h"
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#include "asterisk/sdp_translator.h"
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#include "asterisk/vector.h"
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#include "asterisk/utils.h"
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#include "../include/asterisk/sdp.h"
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#include "asterisk/stream.h"
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enum ast_sdp_state_machine {
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/*! \brief The initial state.
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*
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* The state machine starts here. It also goes back to this
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* state whenever ast_sdp_state_reset() is called.
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*/
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SDP_STATE_INITIAL,
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/*! \brief We are the SDP offerer.
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*
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* The state machine enters this state if in the initial state
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* and ast_sdp_state_get_local() is called. When this state is
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* entered, a local SDP is created and then returned.
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*/
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SDP_STATE_OFFERER,
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/*! \brief We are the SDP answerer.
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*
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* The state machine enters this state if in the initial state
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* and ast_sdp_state_set_remote() is called.
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*/
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SDP_STATE_ANSWERER,
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/*! \brief The SDP has been negotiated.
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*
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* This state can be entered from either the offerer or answerer
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* state. When this state is entered, a joint SDP is created.
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*/
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SDP_STATE_NEGOTIATED,
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/*! \brief Not an actual state.
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*
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* This is just here to mark the end of the enumeration.
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*/
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SDP_STATE_END,
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};
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typedef int (*state_fn)(struct ast_sdp_state *state);
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struct ast_sdp_state {
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/*! Local capabilities, learned through configuration */
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struct ast_stream_topology *local_capabilities;
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/*! Remote capabilities, learned through remote SDP */
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struct ast_stream_topology *remote_capabilities;
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/*! Joint capabilities. The combined local and remote capabilities. */
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struct ast_stream_topology *joint_capabilities;
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/*! Local SDP. Generated via the options and local capabilities. */
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struct ast_sdp *local_sdp;
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/*! Remote SDP. Received directly from a peer. */
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struct ast_sdp *remote_sdp;
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/*! Joint SDP. The merged local and remote SDPs. */
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struct ast_sdp *joint_sdp;
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/*! SDP options. Configured options beyond media capabilities. */
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struct ast_sdp_options *options;
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/*! Translator that puts SDPs into the expected representation */
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struct ast_sdp_translator *translator;
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/*! The current state machine state that we are in */
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enum ast_sdp_state_machine state;
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};
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struct ast_sdp_state *ast_sdp_state_alloc(struct ast_stream_topology *streams,
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struct ast_sdp_options *options)
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{
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struct ast_sdp_state *sdp_state;
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sdp_state = ast_calloc(1, sizeof(*sdp_state));
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if (!sdp_state) {
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return NULL;
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}
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sdp_state->options = options;
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sdp_state->translator = ast_sdp_translator_new(ast_sdp_options_get_impl(sdp_state->options));
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if (!sdp_state->translator) {
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ast_sdp_state_free(sdp_state);
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return NULL;
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}
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sdp_state->local_capabilities = ast_stream_topology_clone(streams);
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if (!sdp_state->local_capabilities) {
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ast_sdp_state_free(sdp_state);
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return NULL;
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}
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sdp_state->state = SDP_STATE_INITIAL;
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return sdp_state;
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}
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void ast_sdp_state_free(struct ast_sdp_state *sdp_state)
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{
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if (!sdp_state) {
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return;
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}
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ast_stream_topology_free(sdp_state->local_capabilities);
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ast_stream_topology_free(sdp_state->remote_capabilities);
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ast_stream_topology_free(sdp_state->joint_capabilities);
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ast_sdp_free(sdp_state->local_sdp);
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ast_sdp_free(sdp_state->remote_sdp);
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ast_sdp_free(sdp_state->joint_sdp);
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ast_sdp_options_free(sdp_state->options);
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ast_sdp_translator_free(sdp_state->translator);
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}
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struct ast_rtp_instance *ast_sdp_state_get_rtp_instance(
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const struct ast_sdp_state *sdp_state, int stream_index)
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{
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struct ast_stream *stream;
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ast_assert(sdp_state != NULL);
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stream = ast_stream_topology_get_stream(sdp_state->local_capabilities, stream_index);
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if (!stream) {
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return NULL;
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}
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return (struct ast_rtp_instance *)ast_stream_get_data(stream, AST_STREAM_DATA_RTP_INSTANCE);
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}
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const struct ast_stream_topology *ast_sdp_state_get_joint_topology(
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const struct ast_sdp_state *sdp_state)
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{
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ast_assert(sdp_state != NULL);
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if (sdp_state->state == SDP_STATE_NEGOTIATED) {
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return sdp_state->joint_capabilities;
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} else {
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return sdp_state->local_capabilities;
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}
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}
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const struct ast_stream_topology *ast_sdp_state_get_local_topology(
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const struct ast_sdp_state *sdp_state)
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{
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ast_assert(sdp_state != NULL);
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return sdp_state->local_capabilities;
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}
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const struct ast_sdp_options *ast_sdp_state_get_options(
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const struct ast_sdp_state *sdp_state)
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{
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ast_assert(sdp_state != NULL);
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return sdp_state->options;
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}
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#if 0
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static int merge_sdps(struct ast_sdp_state *sdp_state)
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{
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ast_assert(sdp_state->local_sdp != NULL);
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ast_assert(sdp_state->remote_sdp != NULL);
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/* XXX STUB */
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/* The goal of this function is to take
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* sdp_state->local_sdp and sdp_state->remote_sdp
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* and negotiate those into a joint SDP. This joint
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* SDP should be stored in sdp_state->joint_sdp. After
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* the joint SDP is created, the joint SDP should be
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* used to create the joint topology. Finally, if necessary,
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* the RTP session may need to be adjusted in some ways. For
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* instance, if we previously opened three ports for three
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* streams, but we negotiate down to two streams, then we
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* can shut down the port for the third stream. Similarly,
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* if we end up negotiating something like BUNDLE, then we may
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* need to tell the RTP layer to close ports and to multiplex
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* streams.
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*/
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return 0;
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}
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#endif
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const struct ast_sdp *ast_sdp_state_get_local_sdp(struct ast_sdp_state *sdp_state)
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{
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ast_assert(sdp_state != NULL);
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if (!sdp_state->local_sdp) {
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sdp_state->local_sdp = ast_sdp_create_from_state(sdp_state);
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}
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return sdp_state->local_sdp;
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}
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const void *ast_sdp_state_get_local_sdp_impl(struct ast_sdp_state *sdp_state)
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{
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const struct ast_sdp *sdp = ast_sdp_state_get_local_sdp(sdp_state);
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if (!sdp) {
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return NULL;
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}
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return ast_sdp_translator_from_sdp(sdp_state->translator, sdp);
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}
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void ast_sdp_state_set_remote_sdp(struct ast_sdp_state *sdp_state, struct ast_sdp *sdp)
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{
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ast_assert(sdp_state != NULL);
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sdp_state->remote_sdp = sdp;
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}
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int ast_sdp_state_set_remote_sdp_from_impl(struct ast_sdp_state *sdp_state, void *remote)
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{
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struct ast_sdp *sdp;
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ast_assert(sdp_state != NULL);
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sdp = ast_sdp_translator_to_sdp(sdp_state->translator, remote);
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if (!sdp) {
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return -1;
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}
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sdp_state->remote_sdp = sdp;
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return 0;
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}
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int ast_sdp_state_reset(struct ast_sdp_state *sdp_state)
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{
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ast_assert(sdp_state != NULL);
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ast_sdp_free(sdp_state->local_sdp);
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sdp_state->local_sdp = NULL;
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ast_sdp_free(sdp_state->remote_sdp);
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sdp_state->remote_sdp = NULL;
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ast_sdp_free(sdp_state->joint_sdp);
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sdp_state->joint_sdp = NULL;
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ast_stream_topology_free(sdp_state->remote_capabilities);
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sdp_state->remote_capabilities = NULL;
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ast_stream_topology_free(sdp_state->joint_capabilities);
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sdp_state->joint_capabilities = NULL;
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sdp_state->state = SDP_STATE_INITIAL;
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return 0;
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}
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