utils.h File Reference

TURN REST API client. More...

#include <stdint.h>
#include <glib.h>
#include <jansson.h>

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Data Structures
struct	janus_json_parameter
struct	janus_vp8_simulcast_context
	VP8 simulcasting context, in order to make sure SSRC changes result in coherent picid/temporal level increases. More...
struct	janus_vp9_svc_info
	VP9 SVC info, as parsed from a payload descriptor. More...

Macros
#define	JANUS_JSON_STRING   JSON_STRING
#define	JANUS_JSON_INTEGER   JSON_INTEGER
#define	JANUS_JSON_OBJECT   JSON_OBJECT
#define	JANUS_JSON_BOOL   JSON_TRUE
#define	JANUS_JSON_PARAM_REQUIRED   1
#define	JANUS_JSON_PARAM_POSITIVE   2
#define	JANUS_JSON_PARAM_NONEMPTY   4
#define	JANUS_VALIDATE_JSON_OBJECT_FORMAT(missing_format, invalid_format, obj, params, error_code, error_cause, log_error, missing_code, invalid_code)
	Validates the JSON object against the description of its parameters. More...
#define	JANUS_VALIDATE_JSON_OBJECT(obj, params, error_code, error_cause, log_error, missing_code, invalid_code)   JANUS_VALIDATE_JSON_OBJECT_FORMAT("Missing mandatory element (%s)", "Invalid element type (%s should be %s)", obj, params, error_code, error_cause, log_error, missing_code, invalid_code)
	Validates the JSON object against the description of its parameters. More...
#define	JANUS_CHECK_SECRET(secret, obj, member, error_code, error_cause, missing_code, invalid_code, unauthorized_code)
	If the secret isn't NULL, check the secret after validating the specified member of the JSON object. More...

Typedefs
typedef struct janus_vp8_simulcast_context	janus_vp8_simulcast_context
	VP8 simulcasting context, in order to make sure SSRC changes result in coherent picid/temporal level increases. More...
typedef struct janus_vp9_svc_info	janus_vp9_svc_info
	VP9 SVC info, as parsed from a payload descriptor. More...

Functions
gint64	janus_get_monotonic_time (void)
	Helper to retrieve the system monotonic time, as Glib's g_get_monotonic_time may not be available (only since 2.28) More...
gint64	janus_get_real_time (void)
	Helper to retrieve the system real time, as Glib's g_get_real_time may not be available (only since 2.28) More...
char *	janus_string_replace (char *message, const char *old_string, const char *new_string) G_GNUC_WARN_UNUSED_RESULT
	Helper to replace strings. More...
gboolean	janus_is_true (const char *value)
	Helper to parse yes/no|true/false configuration values. More...
gboolean	janus_strcmp_const_time (const void *str1, const void *str2)
	Helper to compare strings in constant time. More...
guint32	janus_random_uint32 (void)
	Helper to generate random 32-bit unsigned integers (useful for SSRCs, etc.) More...
guint64	janus_random_uint64 (void)
	Helper to generate random 64-bit unsigned integers (useful for Janus IDs) More...
char *	janus_random_uuid (void)
	Helper to generate random UUIDs (needed by some plugins) More...
guint64 *	janus_uint64_dup (guint64 num)
	Helper to generate an allocated copy of a guint64 number. More...
int	janus_string_to_uint8 (const char *str, uint8_t *num)
	Helper method to convert a string to a uint8_t. More...
int	janus_string_to_uint16 (const char *str, uint16_t *num)
	Helper method to convert a string to a uint16_t. More...
int	janus_string_to_uint32 (const char *str, uint32_t *num)
	Helper method to convert a string to a uint32_t. More...
int	janus_mkdir (const char *dir, mode_t mode)
	Helper to create a new directory, and recursively create parent directories if needed. More...
int	janus_get_codec_pt (const char *sdp, const char *codec)
	Ugly and dirty helper to quickly get the payload type associated with a codec in an SDP. More...
const char *	janus_get_codec_from_pt (const char *sdp, int pt)
	Ugly and dirty helper to quickly get the codec associated with a payload type in an SDP. More...
int	janus_pidfile_create (const char *file)
	Create and lock a PID file. More...
int	janus_pidfile_remove (void)
	Unlock and remove a previously created PID file. More...
void	janus_protected_folder_add (const char *folder)
	Add a folder to the protected list (meaning we won't create files there, like recordings or pcap dumps) More...
gboolean	janus_is_folder_protected (const char *path)
	Check if the path points to a protected folder. More...
void	janus_protected_folders_clear (void)
	Cleanup the list of protected folder. More...
void	janus_get_json_type_name (int jtype, unsigned int flags, char *type_name)
	Creates a string describing the JSON type and constraint. More...
gboolean	janus_json_is_valid (json_t *val, json_type jtype, unsigned int flags)
	Checks whether the JSON value matches the type and constraint. More...
gboolean	janus_vp8_is_keyframe (const char *buffer, int len)
	Helper method to check if a VP8 frame is a keyframe or not. More...
gboolean	janus_vp9_is_keyframe (const char *buffer, int len)
	Helper method to check if a VP9 frame is a keyframe or not. More...
gboolean	janus_h264_is_keyframe (const char *buffer, int len)
	Helper method to check if an H.264 frame is a keyframe or not. More...
void	janus_vp8_simulcast_context_reset (janus_vp8_simulcast_context *context)
	Set (or reset) the context fields to their default values. More...
int	janus_vp8_parse_descriptor (char *buffer, int len, uint16_t *picid, uint8_t *tl0picidx, uint8_t *tid, uint8_t *y, uint8_t *keyidx)
	Helper method to parse a VP8 payload descriptor for useful info (e.g., when simulcasting) More...
void	janus_vp8_simulcast_descriptor_update (char *buffer, int len, janus_vp8_simulcast_context *context, gboolean switched)
	Use the context info to update the RTP header of a packet, if needed. More...
int	janus_vp9_parse_svc (char *buffer, int len, gboolean *found, janus_vp9_svc_info *info)
	Helper method to parse a VP9 payload descriptor for SVC-related info (e.g., when SVC is enabled) More...
guint32	janus_push_bits (guint32 word, size_t num, guint32 val)
	Helper method to push individual bits at the end of a word. More...
void	janus_set1 (guint8 *data, size_t i, guint8 val)
	Helper method to set one byte at a memory position. More...
void	janus_set2 (guint8 *data, size_t i, guint32 val)
	Helper method to set two bytes at a memory position. More...
void	janus_set3 (guint8 *data, size_t i, guint32 val)
	Helper method to set three bytes at a memory position. More...
void	janus_set4 (guint8 *data, size_t i, guint32 val)
	Helper method to set four bytes at a memory position. More...
size_t	janus_gzip_compress (int compression, char *text, size_t tlen, char *compressed, size_t zlen)
	Helper method to compress a string to gzip (using zlib) More...

Flags helper methods
typedef gsize	janus_flags
	Janus flags container. More...
void	janus_flags_reset (janus_flags *flags)
	Janus flags reset method. More...
void	janus_flags_set (janus_flags *flags, gsize flag)
	Janus flags set method. More...
void	janus_flags_clear (janus_flags *flags, gsize flag)
	Janus flags clear method. More...
gboolean	janus_flags_is_set (janus_flags *flags, gsize flag)
	Janus flags check method. More...

Detailed Description

TURN REST API client.

Utilities and helpers (headers)

TURN REST API client (headers)

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 the draft-uberti-rtcweb-turn-rest-00 draft, that is a REST API that can be used to access TURN services, more specifically credentials to use. Currently implemented in both rfc5766-turn-server and coturn, and so should be generic enough to be usable here.

Note

This implementation depends on libcurl and is optional.

Core

Author

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

Copyright

GNU General Public License v3

Implementations of a few methods that may be of use here and there in the code.

Core

Macro Definition Documentation

#define JANUS_CHECK_SECRET	(		secret,
			obj,
			member,
			error_code,
			error_cause,
			missing_code,
			invalid_code,
			unauthorized_code
	)

Value:

do { \
                if (secret) { \
                        static struct janus_json_parameter secret_parameters[] = { \
                                {member, JSON_STRING, JANUS_JSON_PARAM_REQUIRED} \
                        }; \
			JANUS_VALIDATE_JSON_OBJECT(obj, secret_parameters, error_code, error_cause, TRUE, missing_code, invalid_code); \
                        if(error_code == 0 && !janus_strcmp_const_time((secret), json_string_value(json_object_get(obj, member)))) { \
                                error_code = (unauthorized_code); \
				JANUS_LOG(LOG_ERR, "Unauthorized (wrong %s)\n", member); \
                                if(error_cause != NULL) \
                                        g_snprintf(error_cause, sizeof(error_cause), "Unauthorized (wrong %s)", member); \
                        } \
                } \
        } while(0)

If the secret isn't NULL, check the secret after validating the specified member of the JSON object.

Parameters

	secret	The secret to be checked; no check if the secret is NULL
	obj	The JSON object to be validated
	member	The JSON member with the secret, usually "secret" or "pin"
[out]	error_code	int to return error code
[out]	error_cause	Array of char or NULL to return the error descriptions; the array has to be a global or stack variable to make sizeof work; the required size is 60
	missing_code	The code to be returned in error_code if a parameter is missing
	invalid_code	The code to be returned in error_code if a parameter is invalid
	unauthorized_code	The code to be returned in error_code if the secret doesn't match

#define JANUS_JSON_BOOL   JSON_TRUE

#define JANUS_JSON_INTEGER   JSON_INTEGER

#define JANUS_JSON_OBJECT   JSON_OBJECT

#define JANUS_JSON_PARAM_NONEMPTY   4

#define JANUS_JSON_PARAM_POSITIVE   2

#define JANUS_JSON_PARAM_REQUIRED   1

#define JANUS_JSON_STRING   JSON_STRING

#define JANUS_VALIDATE_JSON_OBJECT	(		obj,
			params,
			error_code,
			error_cause,
			log_error,
			missing_code,
			invalid_code
	)		JANUS_VALIDATE_JSON_OBJECT_FORMAT("Missing mandatory element (%s)", "Invalid element type (%s should be %s)", obj, params, error_code, error_cause, log_error, missing_code, invalid_code)

Validates the JSON object against the description of its parameters.

Parameters

	obj	The JSON object to be validated
	params	Array of struct janus_json_parameter to describe the parameters; the array has to be a global or stack variable to make sizeof work
[out]	error_code	int to return error code
[out]	error_cause	Array of char or NULL to return the error descriptions; the array has to be a global or stack variable to make sizeof work; the required size is the length of the longest parameter name plus 54 for the format string and type description
	log_error	If TRUE, log any error with JANUS_LOG(LOG_ERR)
	missing_code	The code to be returned in error_code if a parameter is missing
	invalid_code	The code to be returned in error_code if a parameter is invalid

#define JANUS_VALIDATE_JSON_OBJECT_FORMAT	(		missing_format,
			invalid_format,
			obj,
			params,
			error_code,
			error_cause,
			log_error,
			missing_code,
			invalid_code
	)

Value:

do { \
                error_code = 0; \
                unsigned int i; \
                for(i = 0; i < sizeof(params) / sizeof(struct janus_json_parameter); i++) { \
			json_t *val = json_object_get(obj, params[i].name); \
                        if(!val) { \
                                if((params[i].flags & JANUS_JSON_PARAM_REQUIRED) != 0) {        \
                                        error_code = (missing_code); \
                                        if(log_error) \
						JANUS_LOG(LOG_ERR, missing_format "\n", params[i].name); \
                                        if(error_cause != NULL) \
                                                g_snprintf(error_cause, sizeof(error_cause), missing_format, params[i].name); \
                                        break; \
                                } \
                                continue; \
                        } \
                        if(!janus_json_is_valid(val, params[i].jtype, params[i].flags)) { \
                                error_code = (invalid_code); \
                                char type_name[20]; \
				janus_get_json_type_name(params[i].jtype, params[i].flags, type_name); \
                                if(log_error) \
					JANUS_LOG(LOG_ERR, invalid_format "\n", params[i].name, type_name); \
                                if(error_cause != NULL) \
                                        g_snprintf(error_cause, sizeof(error_cause), invalid_format, params[i].name, type_name); \
                                break; \
                        } \
                } \
        } while(0)

Validates the JSON object against the description of its parameters.

Parameters

	missing_format	printf format to indicate a missing required parameter; needs one s for the parameter name
	invalid_format	printf format to indicate an invalid parameter; needs two s for parameter name and type description from janus_get_json_type_name
	obj	The JSON object to be validated
	params	Array of struct janus_json_parameter to describe the parameters; the array has to be a global or stack variable to make sizeof work
[out]	error_code	int to return error code
[out]	error_cause	Array of char or NULL to return the error descriptions; the array has to be a global or stack variable to make sizeof work; the required size is the length of the format string plus the length of the longest parameter name plus 19 for the type description
	log_error	If TRUE, log any error with JANUS_LOG(LOG_ERR)
	missing_code	The code to be returned in error_code if a parameter is missing
	invalid_code	The code to be returned in error_code if a parameter is invalid

Typedef Documentation

typedef gsize janus_flags

Janus flags container.

typedef struct janus_vp8_simulcast_context janus_vp8_simulcast_context

VP8 simulcasting context, in order to make sure SSRC changes result in coherent picid/temporal level increases.

typedef struct janus_vp9_svc_info janus_vp9_svc_info

VP9 SVC info, as parsed from a payload descriptor.

Function Documentation

void janus_flags_clear	(	janus_flags *	flags,
		gsize	flag
	)

Janus flags clear method.

Parameters

[in]	flags	The janus_flags instance to update
[in]	flag	The flag to clear

gboolean janus_flags_is_set	(	janus_flags *	flags,
		gsize	flag
	)

Janus flags check method.

Parameters

[in]	flags	The janus_flags instance to check
[in]	flag	The flag to check

Returns

true if the flag is set, false otherwise

void janus_flags_reset

(

janus_flags *

flags

)

Janus flags reset method.

Parameters

[in]

flags

The janus_flags instance to reset

void janus_flags_set	(	janus_flags *	flags,
		gsize	flag
	)

Janus flags set method.

Parameters

[in]	flags	The janus_flags instance to update
[in]	flag	The flag to set

const char* janus_get_codec_from_pt	(	const char *	sdp,
		int	pt
	)

Ugly and dirty helper to quickly get the codec associated with a payload type in an SDP.

Parameters

sdp	The SDP to parse
pt	The payload type to look for

Returns

The codec name, if found, NULL otherwise

int janus_get_codec_pt	(	const char *	sdp,
		const char *	codec
	)

Ugly and dirty helper to quickly get the payload type associated with a codec in an SDP.

Parameters

sdp	The SDP to parse
codec	The codec to look for

Returns

The payload type, if found, -1 otherwise

void janus_get_json_type_name	(	int	jtype,
		unsigned int	flags,
		char *	type_name
	)

Creates a string describing the JSON type and constraint.

Parameters

	jtype	The JSON type, e.g., JSON_STRING
	flags	Indicates constraints for the described type
[out]	type_name	The type description, e.g., "a positive integer"; required size is 19 characters

Returns

0 if successful, a negative integer otherwise

gint64 janus_get_monotonic_time

(

void

)

Helper to retrieve the system monotonic time, as Glib's g_get_monotonic_time may not be available (only since 2.28)

Returns

The system monotonic time

gint64 janus_get_real_time

(

void

)

Helper to retrieve the system real time, as Glib's g_get_real_time may not be available (only since 2.28)

Returns

The system real time

size_t janus_gzip_compress	(	int	compression,
		char *	text,
		size_t	tlen,
		char *	compressed,
		size_t	zlen
	)

Helper method to compress a string to gzip (using zlib)

Note

It's up to you to provide a buffer large enough for the compressed data: in case the buffer isn't large enough, the request will fail

Parameters

[in]	compression	Compression factor (1=fastest, 9=best compression)
[in]	text	Pointer to the string to compress
[in]	tlen	Length of the string to compress
[in]	compressed	Pointer to the buffer where to compress the string to
[in]	zlen	Size of the output buffer

Returns

The size of the compressed data, if successful, or 0 otherwise

gboolean janus_h264_is_keyframe	(	const char *	buffer,
		int	len
	)

Helper method to check if an H.264 frame is a keyframe or not.

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload

Returns

TRUE if it's a keyframe, FALSE otherwise

gboolean janus_is_folder_protected

(

const char *

path

)

Check if the path points to a protected folder.

Parameters

path	Path we need to check

Returns

TRUE if the folder is protected, and FALSE otherwise

gboolean janus_is_true

(

const char *

value

)

Helper to parse yes/no|true/false configuration values.

Parameters

value

The configuration value to parse

Returns

true if the value contains a "yes", "YES", "true", TRUE", "1", false otherwise

gboolean janus_json_is_valid	(	json_t *	val,
		json_type	jtype,
		unsigned int	flags
	)

Checks whether the JSON value matches the type and constraint.

Parameters

val	The JSON value to be checked
jtype	The JSON type, e.g., JSON_STRING
flags	Indicates constraints for the described type

Returns

TRUE if the value is valid

int janus_mkdir	(	const char *	dir,
		mode_t	mode
	)

Helper to create a new directory, and recursively create parent directories if needed.

Parameters

dir	Path to the new folder to create
mode	File permissions for the new directory file

Returns

An integer like the regular mkdir does

Note

A failure may indicate that creating any of the subdirectories failed: some may still have been created

int janus_pidfile_create

(

const char *

file

)

Create and lock a PID file.

Parameters

file	Path to the PID file to use

Returns

0 if successful, a negative integer otherwise

int janus_pidfile_remove

(

void

)

Unlock and remove a previously created PID file.

Returns

0 if successful, a negative integer otherwise

void janus_protected_folder_add

(

const char *

folder

)

Add a folder to the protected list (meaning we won't create files there, like recordings or pcap dumps)

Parameters

folder

Folder to protect

void janus_protected_folders_clear

(

void

)

Cleanup the list of protected folder.

guint32 janus_push_bits ( guint32  word, size_t  num, guint32  val  )

inline

Helper method to push individual bits at the end of a word.

Parameters

[in]	word	Initial value of word
[in]	num	Number of bits to push
[in]	val	Value of bits to push

Returns

0 New word value

guint32 janus_random_uint32

(

void

)

Helper to generate random 32-bit unsigned integers (useful for SSRCs, etc.)

Note

Currently just wraps g_random_int()

Returns

A random 32-bit unsigned integer

guint64 janus_random_uint64

(

void

)

Helper to generate random 64-bit unsigned integers (useful for Janus IDs)

Returns

A random 64-bit unsigned integer

char* janus_random_uuid

(

void

)

Helper to generate random UUIDs (needed by some plugins)

Returns

A random UUID string, which must be deallocated with g_free

void janus_set1 ( guint8 *  data, size_t  i, guint8  val  )

inline

Helper method to set one byte at a memory position.

Parameters

[in]	data	memory data pointer
[in]	i	position in memory to change
[in]	val	value to write

void janus_set2 ( guint8 *  data, size_t  i, guint32  val  )

inline

Helper method to set two bytes at a memory position.

Parameters

[in]	data	memory data pointer
[in]	i	position in memory to change
[in]	val	value to write

void janus_set3 ( guint8 *  data, size_t  i, guint32  val  )

inline

Helper method to set three bytes at a memory position.

Parameters

[in]	data	memory data pointer
[in]	i	position in memory to change
[in]	val	value to write

void janus_set4 ( guint8 *  data, size_t  i, guint32  val  )

inline

Helper method to set four bytes at a memory position.

Parameters

[in]	data	memory data pointer
[in]	i	position in memory to change
[in]	val	value to write

gboolean janus_strcmp_const_time	(	const void *	str1,
		const void *	str2
	)

Helper to compare strings in constant time.

Parameters

str1	The first string to compare
str2	The second string to compare

Returns

true if the strings are the same, false otherwise

char* janus_string_replace	(	char *	message,
		const char *	old_string,
		const char *	new_string
	)

Helper to replace strings.

Parameters

message	The string that contains the text to replace, which may be freed if it is too short
old_string	The old text to replace
new_string	The new text

Returns

A pointer to the updated text string (re-allocated or just updated)

int janus_string_to_uint16	(	const char *	str,
		uint16_t *	num
	)

Helper method to convert a string to a uint16_t.

Note

The value of num should be ignored, if the method returned an error

Parameters

[in]	str	The string to convert
[out]	num	Pointer to the converted number

Returns

0 if successful, or a negative integer otherwise (e.g., -ERANGE if the value is out of range)

int janus_string_to_uint32	(	const char *	str,
		uint32_t *	num
	)

Helper method to convert a string to a uint32_t.

Note

The value of num should be ignored, if the method returned an error

Parameters

[in]	str	The string to convert
[out]	num	Pointer to the converted number

Returns

0 if successful, or a negative integer otherwise (e.g., -ERANGE if the value is out of range)

int janus_string_to_uint8	(	const char *	str,
		uint8_t *	num
	)

Helper method to convert a string to a uint8_t.

Note

The value of num should be ignored, if the method returned an error

Parameters

[in]	str	The string to convert
[out]	num	Pointer to the converted number

Returns

0 if successful, or a negative integer otherwise (e.g., -ERANGE if the value is out of range)

guint64* janus_uint64_dup

(

guint64

num

)

Helper to generate an allocated copy of a guint64 number.

Note

While apparently silly, this is needed in order to make sure guint64 values used as keys in GHashTable operations are not lost: using temporary guint64 numbers in a g_hash_table_insert, for instance, will cause the key to contain garbage as soon as the temporary variable is lost, and all opererations on the key to fail

Parameters

num	The guint64 number to duplicate

Returns

A pointer to a guint64 number, if successful, NULL otherwise

gboolean janus_vp8_is_keyframe	(	const char *	buffer,
		int	len
	)

Helper method to check if a VP8 frame is a keyframe or not.

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload

Returns

TRUE if it's a keyframe, FALSE otherwise

int janus_vp8_parse_descriptor	(	char *	buffer,
		int	len,
		uint16_t *	picid,
		uint8_t *	tl0picidx,
		uint8_t *	tid,
		uint8_t *	y,
		uint8_t *	keyidx
	)

Helper method to parse a VP8 payload descriptor for useful info (e.g., when simulcasting)

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload
[out]	picid	The Picture ID
[out]	tl0picidx	Temporal level zero index
[out]	tid	Temporal-layer index
[out]	y	Layer sync bit
[out]	keyidx	Temporal key frame index

Returns

0 in case of success, a negative integer otherwise

void janus_vp8_simulcast_context_reset

(

janus_vp8_simulcast_context *

context

)

Set (or reset) the context fields to their default values.

Parameters

[in]

context

The context to (re)set

void janus_vp8_simulcast_descriptor_update	(	char *	buffer,
		int	len,
		janus_vp8_simulcast_context *	context,
		gboolean	switched
	)

Use the context info to update the RTP header of a packet, if needed.

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload
[in]	context	The context to use as a reference
[in]	switched	Whether there has been a source switch or not (important to compute offsets)

gboolean janus_vp9_is_keyframe	(	const char *	buffer,
		int	len
	)

Helper method to check if a VP9 frame is a keyframe or not.

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload

Returns

TRUE if it's a keyframe, FALSE otherwise

int janus_vp9_parse_svc	(	char *	buffer,
		int	len,
		gboolean *	found,
		janus_vp9_svc_info *	info
	)

Helper method to parse a VP9 payload descriptor for SVC-related info (e.g., when SVC is enabled)

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload
[out]	found	Whether any SVC related info has been found or not
[out]	info	Pointer to a janus_vp9_svc_info structure for passing the parsed info back

Returns

0 in case of success, a negative integer otherwise