sdp.c File Reference

SDP processing. More...

#include <netdb.h>
#include <gio/gio.h>
#include "janus.h"
#include "ice.h"
#include "sdp.h"
#include "utils.h"
#include "ip-utils.h"
#include "debug.h"
#include "events.h"

Include dependency graph for sdp.c:

Data Structures
struct	janus_sdp_mdns_candidate

Typedefs
typedef struct janus_sdp_mdns_candidate	janus_sdp_mdns_candidate

Functions
janus_sdp *	janus_sdp_preparse (void *ice_handle, const char *jsep_sdp, char *error_str, size_t errlen, janus_dtls_role *dtls_role, int *audio, int *video, int *data)
	Method to pre-parse a session description.
int	janus_sdp_process (void *ice_handle, janus_sdp *remote_sdp, gboolean rids_hml, gboolean update)
	Method to process a parsed session description.
int	janus_sdp_parse_candidate (void *ice_stream, const char *candidate, int trickle)
	Method to parse a single candidate.
int	janus_sdp_parse_ssrc_group (void *ice_stream, const char *group_attr, int video)
	Method to parse a SSRC group attribute.
int	janus_sdp_parse_ssrc (void *ice_stream, const char *ssrc_attr, int video)
	Method to parse a SSRC attribute.
int	janus_sdp_anonymize (janus_sdp *anon)
	Method to strip/anonymize a session description.
char *	janus_sdp_merge (void *ice_handle, janus_sdp *anon, gboolean offer)
	Method to merge a stripped session description and the right transport information.

Detailed Description

SDP processing.

Author

Lorenzo Miniero loren.nosp@m.zo@m.nosp@m.eetec.nosp@m.ho.c.nosp@m.om

Copyright

GNU General Public License v3

Implementation of an SDP parser/merger/generator in the server. Each SDP coming from peers is stripped/anonymized before it is passed to the plugins: all DTLS/ICE/transport related information is removed, only leaving the relevant information in place. SDP coming from plugins is stripped/anonymized as well, and merged with the proper DTLS/ICE/transport information before it is sent to the peers. The actual SDP processing (parsing SDP strings, representation of SDP as an internal format, and so on) is done via the tools provided in sdp-utils.h.

Protocols

Typedef Documentation

janus_sdp_mdns_candidate

typedef struct janus_sdp_mdns_candidate janus_sdp_mdns_candidate

Function Documentation

janus_sdp_anonymize()

int janus_sdp_anonymize

(

janus_sdp *

sdp

)

Method to strip/anonymize a session description.

Parameters

[in,out]

sdp

The Janus SDP description object to strip/anonymize

Returns

0 in case of success, a non-zero integer in case of an error

janus_sdp_merge()

char * janus_sdp_merge	(	void *	handle,
		janus_sdp *	sdp,
		gboolean	offer )

Method to merge a stripped session description and the right transport information.

Parameters

[in]	handle	Opaque pointer to the ICE handle this session description is related to
[in]	sdp	The Janus SDP description object to merge/enrich
[in]	offer	Whether the SDP is an offer or an answer

Returns

A string containing the full session description in case of success, NULL if the SDP is invalid

janus_sdp_parse_candidate()

int janus_sdp_parse_candidate	(	void *	stream,
		const char *	candidate,
		int	trickle )

Method to parse a single candidate.

This method will parse a single remote candidate provided by a peer, whether it is trickling or not

Parameters

[in]	stream	Opaque pointer to the ICE stream this candidate refers to
[in]	candidate	The remote candidate to process
[in]	trickle	Whether this is a trickle candidate, or coming from the SDP

Returns

0 in case of success, a non-zero integer in case of an error

janus_sdp_parse_ssrc()

int janus_sdp_parse_ssrc	(	void *	stream,
		const char *	ssrc_attr,
		int	video )

Method to parse a SSRC attribute.

This method will parse a SSRC attribute, and set it for the peer

Parameters

[in]	stream	Opaque pointer to the ICE stream this candidate refers to
[in]	ssrc_attr	The SSRC attribute value to parse
[in]	video	Whether this is a video SSRC or not

Returns

0 in case of success, a non-zero integer in case of an error

janus_sdp_parse_ssrc_group()

int janus_sdp_parse_ssrc_group	(	void *	stream,
		const char *	group_attr,
		int	video )

Method to parse a SSRC group attribute.

This method will parse a SSRC group attribute, and set the parsed values for the peer

Parameters

[in]	stream	Opaque pointer to the ICE stream this candidate refers to
[in]	group_attr	The SSRC group attribute value to parse
[in]	video	Whether this is video-related or not

Returns

0 in case of success, a non-zero integer in case of an error

janus_sdp_preparse()

janus_sdp * janus_sdp_preparse	(	void *	handle,
		const char *	jsep_sdp,
		char *	error_str,
		size_t	errlen,
		janus_dtls_role *	dtls_role,
		int *	audio,
		int *	video,
		int *	data )

Method to pre-parse a session description.

This method is only used to quickly check how many audio and video lines are in an SDP, and to generate a Janus SDP instance

Parameters

[in]	handle	Opaque pointer to the ICE handle this session description will modify
[in]	jsep_sdp	The SDP that the browser peer originated
[in,out]	error_str	Buffer to receive a reason for an error, if any
[in]	errlen	The length of the error buffer
[out]	dtls_role	The advertised DTLS role
[out]	audio	The number of audio m-lines
[out]	video	The number of video m-lines
[out]	data	The number of SCTP m-lines

Returns

The Janus SDP object in case of success, NULL in case the SDP is invalid

janus_sdp_process()

int janus_sdp_process	(	void *	handle,
		janus_sdp *	sdp,
		gboolean	rids_hml,
		gboolean	update )

Method to process a parsed session description.

This method will process a session description coming from a peer, and set up the ICE candidates accordingly

Note

While this method can handle SDP updates, renegotiations are currently limited to updates to the media direction of existing media streams (e.g., sendrecv to recvonly) and ICE restarts. Adding/removing streams and supporting multiple streams in the same PeerConnection are still WIP.

Parameters

[in]	handle	Opaque pointer to the ICE handle this session description will modify
[in]	sdp	The Janus SDP object to process
[in]	rids_hml	Whether the order of rids in the SDP, if present, will be h-m-l (TRUE) or l-m-h (FALSE)
[in]	update	Whether this SDP is an update to an existing session or not

Returns

0 in case of success, -1 in case of an error