TURN

TURN — TURN Allocation Usage

Stability Level

Stable, unless otherwise indicated

Functions

Types and Values

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

 

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