sockets API

This document describes a mapping of the Stream Control Transmission Protocol (SCTP) into a sockets API. The benefits of this mapping include compatibility for TCP applications, access to new SCTP features, and a consolidated error and event notification scheme. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document defines extensions to the current sockets API for the Host Identity Protocol (HIP). The extensions focus on the use of public-key-based identifiers discovered via DNS resolution, but also define interfaces for manual bindings between Host Identity Tags (HITs) and locators. With the extensions, the application can also support more relaxed security models where communication can be non-HIP-based, according to local policies. The extensions in this document are experimental and provide basic tools for further experimentation with policies. This document defines an Experimental Protocol for the Internet community.

The IPv6 default address selection document (RFC 3484) describes the rules for selecting source and destination IPv6 addresses, and indicates that applications should be able to reverse the sense of some of the address selection rules through some unspecified API. However, no such socket API exists in the basic (RFC 3493) or advanced (RFC 3542) IPv6 socket API documents. This document fills that gap partially by specifying new socket-level options for source address selection and flags for the getaddrinfo() API to specify address selection based on the source address preference in accordance with the socket-level options that modify the default source address selection algorithm. The socket API described in this document will be particularly useful for IPv6 applications that want to choose between temporary and public addresses, and for Mobile IPv6 aware applications that want to use the care-of address for communication. It also specifies socket options and flags for selecting Cryptographically Generated Address (CGA) or non-CGA source addresses. This memo provides information for the Internet community.

This document describes data structures and API support for Mobile IPv6 as an extension to the Advanced Socket API for IPv6.

Just as the Advanced Sockets API for IPv6 gives access to various extension headers and the ICMPv6 protocol, this document specifies the same level of access for Mobile IPv6 components. It specifies a mechanism for applications to retrieve and set information for Mobility Header messages, Home Address destination options, and Routing Header Type 2 extension headers. It also specifies the common data structures and definitions that might be used by certain advanced Mobile IPv6 socket applications. This memo provides information for the Internet community.

The Internet Group Management Protocol (IGMPv3) for IPv4 and the Multicast Listener Discovery (MLDv2) for IPv6 add the capability for applications to express source filters on multicast group memberships, which allows receiver applications to determine the set of senders (sources) from which to accept multicast traffic. This capability also simplifies support of one-to-many type multicast applications. This document specifies new socket options and functions to manage source filters for IP Multicast group memberships. It also defines the socket structures to provide input and output arguments to these new application program interfaces (APIs). These extensions are designed to provide access to the source filtering features, while introducing a minimum of change into the system and providing complete compatibility for existing multicast applications.

The de facto standard Application Program Interface (API) for TCP/IP applications is the "sockets" interface. Although this API was developed for Unix in the early 1980s it has also been implemented on a wide variety of non-Unix systems. TCP/IP applications written using the sockets API have in the past enjoyed a high degree of portability and we would like the same portability with IPv6 applications. But changes are required to the sockets API to support IPv6 and this memo describes these changes. These include a new socket address structure to carry IPv6 addresses, new address conversion functions, and some new socket options. These extensions are designed to provide access to the basic IPv6 features required by TCP and UDP applications, including multicasting, while introducing a minimum of change into the system and providing complete compatibility for existing IPv4 applications. Additional extensions for advanced IPv6 features (raw sockets and access to the IPv6 extension headers) are defined in another document. This memo provides information for the Internet community.