TURN: libnice Reference Manual

TURN

TURN — TURN Allocation Usage

Stability Level

Stable, unless otherwise indicated

Functions

size_t	stun_usage_turn_create ()
size_t	stun_usage_turn_create_refresh ()
StunUsageTurnReturn	stun_usage_turn_process ()
StunUsageTurnReturn	stun_usage_turn_refresh_process ()
size_t	stun_usage_turn_create_permission ()

Types and Values

enum	StunUsageTurnCompatibility
enum	StunUsageTurnRequestPorts
enum	StunUsageTurnReturn

Includes

#include <stun/usages/turn.h>

Description

The STUN TURN usage allows for easily creating and parsing STUN Allocate requests and responses used for TURN. The API allows you to create a new allocation or refresh an existing one as well as to parse a response to an allocate or refresh request.

Functions

stun_usage_turn_create ()

size_t
stun_usage_turn_create (StunAgent *agent,
                        StunMessage *msg,
                        uint8_t *buffer,
                        size_t buffer_len,
                        StunMessage *previous_response,
                        StunUsageTurnRequestPorts request_ports,
                        int32_t bandwidth,
                        int32_t lifetime,
                        uint8_t *username,
                        size_t username_len,
                        uint8_t *password,
                        size_t password_len,
                        StunUsageTurnCompatibility compatibility);

Create a new TURN Allocation request

Parameters

agent	The StunAgent to use to build the request
msg	The StunMessage to build
buffer	The buffer to use for creating the StunMessage
buffer_len	The size of the `buffer`
previous_response	If this is the first request you are sending, set this argument to NULL, if it's a subsequent request you are building, then set this argument to the response you have received. This argument is used for building long term credentials (using the REALM and NONCE attributes) as well as for getting the RESERVATION-TOKEN attribute when you previously requested an allocation which reserved two ports
request_ports	Specify how you want to request the allocated port(s). This is only used if the compatibility is set to STUN_USAGE_TURN_COMPATIBILITY_DRAFT9 See StunUsageTurnRequestPorts
bandwidth	The bandwidth to request from the server for the allocation. If this value is negative, then no BANDWIDTH attribute is added to the request. This is only used if the compatibility is set to STUN_USAGE_TURN_COMPATIBILITY_DRAFT9
lifetime	The lifetime of the allocation to request from the server. If this value is negative, then no LIFETIME attribute is added to the request. This is only used if the compatibility is set to STUN_USAGE_TURN_COMPATIBILITY_DRAFT9
username	The username to use in the request
username_len	The length of `username`
password	The key to use for building the MESSAGE-INTEGRITY
password_len	The length of `password`
compatibility	The compatibility mode to use for building the Allocation request

Returns

The length of the message to send

stun_usage_turn_create_refresh ()

size_t
stun_usage_turn_create_refresh (StunAgent *agent,
                                StunMessage *msg,
                                uint8_t *buffer,
                                size_t buffer_len,
                                StunMessage *previous_response,
                                int32_t lifetime,
                                uint8_t *username,
                                size_t username_len,
                                uint8_t *password,
                                size_t password_len,
                                StunUsageTurnCompatibility compatibility);

Create a new TURN Refresh request

Parameters

agent	The StunAgent to use to build the request
msg	The StunMessage to build
buffer	The buffer to use for creating the StunMessage
buffer_len	The size of the `buffer`
previous_response	If this is the first request you are sending, set this argument to NULL, if it's a subsequent request you are building, then set this argument to the response you have received. This argument is used for building long term credentials (using the REALM and NONCE attributes)
lifetime	The lifetime of the allocation to request from the server. If this value is negative, then no LIFETIME attribute is added to the request. This is only used if the compatibility is set to STUN_USAGE_TURN_COMPATIBILITY_DRAFT9
username	The username to use in the request
username_len	The length of `username`
password	The key to use for building the MESSAGE-INTEGRITY
password_len	The length of `password`
compatibility	The compatibility mode to use for building the Allocation request

Returns

The length of the message to send

stun_usage_turn_process ()

StunUsageTurnReturn
stun_usage_turn_process (StunMessage *msg,
                         struct sockaddr_storage *relay_addr,
                         socklen_t *relay_addrlen,
                         struct sockaddr_storage *addr,
                         socklen_t *addrlen,
                         struct sockaddr_storage *alternate_server,
                         socklen_t *alternate_server_len,
                         uint32_t *bandwidth,
                         uint32_t *lifetime,
                         StunUsageTurnCompatibility compatibility);

Process a TURN Allocate response and extract the necessary information from the message

Parameters

msg	The message containing the response
relay_addr	A pointer to a sockaddr structure to fill with the relay address that the TURN server allocated for us
relay_addrlen	The length of `relay_addr`
addr	A pointer to a sockaddr structure to fill with the mapped address that the STUN response contains. This argument will only be filled if the return value of the function is STUN_USAGE_TURN_RETURN_MAPPED_SUCCESS
addrlen	The length of `addr`
alternate_server	A pointer to a sockaddr structure to fill with the address of an alternate server to which we should send our new STUN Allocate request, in case the currently used TURN server is requesting the use of an alternate server. This argument will only be filled if the return value of the function is STUN_USAGE_TURN_RETURN_ALTERNATE_SERVER In the case of `STUN_USAGE_TURN_COMPATIBILITY_OC2007` compatibility, the `alternate_server` could be filled at any time, and should only be considered if the request was sent to a different server than the address returned in the `alternate_server` field
alternate_server_len	The length of `alternate_server`
bandwidth	A pointer to fill with the bandwidth the TURN server allocated us
lifetime	A pointer to fill with the lifetime of the allocation
compatibility	The compatibility mode to use for processing the Allocation response

Returns

A StunUsageTurnReturn value

stun_usage_turn_refresh_process ()

StunUsageTurnReturn
stun_usage_turn_refresh_process (StunMessage *msg,
                                 uint32_t *lifetime,
                                 StunUsageTurnCompatibility compatibility);

Process a TURN Refresh response and extract the necessary information from the message

Parameters

msg	The message containing the response
lifetime	A pointer to fill with the lifetime of the allocation
compatibility	The compatibility mode to use for processing the Refresh response

Returns

A StunUsageTurnReturn value. A STUN_USAGE_TURN_RETURN_RELAY_SUCCESS means the Refresh was successful, but no relay address is given (kept the same as for the original allocation)

stun_usage_turn_create_permission ()

size_t
stun_usage_turn_create_permission (StunAgent *agent,
                                   StunMessage *msg,
                                   uint8_t *buffer,
                                   size_t buffer_len,
                                   uint8_t *username,
                                   size_t username_len,
                                   uint8_t *password,
                                   size_t password_len,
                                   uint8_t *realm,
                                   size_t realm_len,
                                   uint8_t *nonce,
                                   size_t nonce_len,
                                   struct sockaddr_storage *peer,
                                   StunUsageTurnCompatibility compatibility);

Create a new TURN CreatePermission request

Parameters

agent	The StunAgent to use to build the request
msg	The StunMessage to build
buffer	The buffer to use for creating the StunMessage
buffer_len	The size of the `buffer`
username	The username to use in the request
username_len	The length of `username`
password	The key to use for building the MESSAGE-INTEGRITY
password_len	The length of `password`
realm	The realm identifier to use in the request
realm_len	The length of `realm`
nonce	Unique and securely random nonce to use in the request
nonce_len	The length of `nonce`
peer	Server-reflexive host address to request permission for
compatibility	The compatibility mode to use for building the CreatePermission request

Returns

The length of the message to send

Types and Values

enum StunUsageTurnCompatibility

Specifies which TURN specification compatibility to use

Members

STUN_USAGE_TURN_COMPATIBILITY_DRAFT9	Use the specification compatible with TURN Draft 09
STUN_USAGE_TURN_COMPATIBILITY_GOOGLE	Use the specification compatible with Google Talk's relay server
STUN_USAGE_TURN_COMPATIBILITY_MSN	Use the specification compatible with MSN TURN servers
STUN_USAGE_TURN_COMPATIBILITY_OC2007	Use the specification compatible with Microsoft Office Communicator 2007
STUN_USAGE_TURN_COMPATIBILITY_RFC5766	Use the specification compatible with RFC 5766 (the final, canonical TURN standard)

enum StunUsageTurnRequestPorts

This enum is used to specify which port configuration you want when creating a new Allocation

Members

STUN_USAGE_TURN_REQUEST_PORT_NORMAL	Request a normal port
STUN_USAGE_TURN_REQUEST_PORT_EVEN	Request an even port
STUN_USAGE_TURN_REQUEST_PORT_EVEN_AND_RESERVE	Request an even port and reserve the next higher port

enum StunUsageTurnReturn

Return value of stun_usage_turn_process() and stun_usage_turn_refresh_process() which allows you to see what status the function call returned.

Members

STUN_USAGE_TURN_RETURN_RELAY_SUCCESS	The response was successful and a relay address is provided
STUN_USAGE_TURN_RETURN_MAPPED_SUCCESS	The response was successful and a relay address as well as a mapped address are provided
STUN_USAGE_TURN_RETURN_ERROR	The response resulted in an error
STUN_USAGE_TURN_RETURN_INVALID	The response is not a valid response
STUN_USAGE_TURN_RETURN_ALTERNATE_SERVER	The server requests the message to be sent to an alternate server