address_families(7) — Linux manual page


address_families(7) Miscellaneous Information Manual address_families(7)

NAME         top

       address_families - socket address families (domains)

SYNOPSIS         top

       #include <sys/types.h>          /* See NOTES */
       #include <sys/socket.h>

       int socket(int domain, int type, int protocol);

DESCRIPTION         top

       The domain argument of the socket(2) specifies a communication
       domain; this selects the protocol family which will be used for
       communication.  These families are defined in <sys/socket.h>.
       The formats currently understood by the Linux kernel include:

              Local communication.  For further information, see

              IPv4 Internet protocols.  For further information, see

              Amateur radio AX.25 protocol.  For further information,
              see ax25(4).

       AF_IPX IPX - Novell protocols.

              AppleTalk For further information, see ddp(7).

              AX.25 packet layer protocol.  For further information, see
              netrom(4), The Packet Radio Protocols and Linux⟩ and the
              AX.25, NET/ROM, and ROSE network programming chapters of
              the Linux Amateur Radio AX.25 HOWTO⟩.

              Can't be used for creating sockets; mostly used for bridge
              links in rtnetlink(7) protocol commands.

              Access to raw ATM Permanent Virtual Circuits (PVCs).  For
              further information, see the ATM on Linux HOWTO⟩.

       AF_X25 ITU-T X.25 / ISO/IEC 8208 protocol.  For further
              information, see x25(7).

              IPv6 Internet protocols.  For further information, see

              RATS (Radio Amateur Telecommunications Society).  Open
              Systems environment (ROSE) AX.25 packet layer protocol.
              For further information, see the resources listed for

              DECet protocol sockets.  See
              Documentation/networking/decnet.txt in the Linux kernel
              source tree for details.

              Reserved for "802.2LLC project"; never used.

              This was a short-lived (between Linux 2.1.30 and
              2.1.99pre2) protocol family for firewall upcalls.

       AF_KEY Key management protocol, originally developed for usage
              with IPsec (since Linux 2.1.38).  This has no relation to
              keyctl(2) and the in-kernel key storage facility.  See RFC
              2367 PF_KEY Key Management API, Version 2⟩ for details.

              Kernel user interface device.  For further information,
              see netlink(7).

              Low-level packet interface.  For further information, see

              Acorn Econet protocol (removed in Linux 3.5).  See the
              Econet documentation 
              ⟨⟩ for

              Access to ATM Switched Virtual Circuits (SVCs) See the ATM
              on Linux HOWTO⟩ for

       AF_RDS Reliable Datagram Sockets (RDS) protocol (since Linux
              2.6.30).  RDS over RDMA has no relation to AF_SMC or
              AF_XDP.  For further information, see rds(7), rds-rdma(7),
              and Documentation/networking/rds.txt in the Linux kernel
              source tree.

              Socket interface over IrDA (moved to staging in Linux
              4.14, removed in Linux 4.17).  For further information,
              see irda(7).

              Generic PPP transport layer, for setting up L2 tunnels
              (L2TP and PPPoE).  See Documentation/networking/l2tp.txt
              in the Linux kernel source tree for details.

              Legacy protocol for wide area network (WAN) connectivity
              that was used by Sangoma WAN cards (called "WANPIPE");
              removed in Linux 2.6.21.

       AF_LLC Logical link control (IEEE 802.2 LLC) protocol, upper part
              of data link layer of ISO/OSI networking protocol stack
              (since Linux 2.4); has no relation to AF_PACKET.  See
              chapter 13.5.3. Logical Link Control in Understanding
              Linux Kernel Internals (O'Reilly Media, 2006) and IEEE
              Standards for Local Area Networks: Logical Link Control
              (The Institute of Electronics and Electronics Engineers,
              Inc., New York, New York, 1985) for details.  See also
              some historical notes 
              ⟨⟩ regarding
              its development.

       AF_IB  InfiniBand native addressing (since Linux 3.11).

              Multiprotocol Label Switching (since Linux 4.1); mostly
              used for configuring MPLS routing via netlink(7), as it
              doesn't expose ability to create sockets to user space.

       AF_CAN Controller Area Network automotive bus protocol (since
              Linux 2.6.25).  See Documentation/networking/can.rst in
              the Linux kernel source tree for details.

              TIPC, "cluster domain sockets" protocol (since Linux
              2.6.16).  See TIPC Programmer's Guide⟩ and the protocol
              description ⟨⟩ for details.

              Bluetooth low-level socket protocol (since Linux 3.11).
              See Bluetooth Management API overview 
              api.txt⟩ and An Introduction to Bluetooth Programming by
              Albert Huang 
              ⟨⟩ for

              IUCV (inter-user communication vehicle) z/VM protocol for
              hypervisor-guest interaction (since Linux 2.6.21); has no
              relation to AF_VSOCK and/or AF_SMC See IUCV protocol
              for details.

              Rx, Andrew File System remote procedure call protocol
              (since Linux 2.6.22).  See
              Documentation/networking/rxrpc.txt in the Linux kernel
              source tree for details.

              New "modular ISDN" driver interface protocol (since Linux
              2.6.27).  See the mISDN wiki 
              ⟨⟩ for details.

              Nokia cellular modem IPC/RPC interface (since Linux
              2.6.31).  See Documentation/networking/phonet.txt in the
              Linux kernel source tree for details.

              IEEE 802.15.4 WPAN (wireless personal area network) raw
              packet protocol (since Linux 2.6.31).  See
              Documentation/networking/ieee802154.txt in the Linux
              kernel source tree for details.

              Ericsson's Communication CPU to Application CPU interface
              (CAIF) protocol (since Linux 2.6.36).  See
              Documentation/networking/caif/Linux-CAIF.txt in the Linux
              kernel source tree for details.

       AF_ALG Interface to kernel crypto API (since Linux 2.6.38).  See
              Documentation/crypto/userspace-if.rst in the Linux kernel
              source tree for details.

              VMWare VSockets protocol for hypervisor-guest interaction
              (since Linux 3.9); has no relation to AF_IUCV and AF_SMC.
              For further information, see vsock(7).

       AF_KCM KCM (kernel connection multiplexer) interface (since Linux
              4.6).  See Documentation/networking/kcm.txt in the Linux
              kernel source tree for details.

              Qualcomm IPC router interface protocol (since Linux 4.7).

       AF_SMC SMC-R (shared memory communications over RDMA) protocol
              (since Linux 4.11), and SMC-D (shared memory
              communications, direct memory access) protocol for intra-
              node z/VM quest interaction (since Linux 4.19); has no
              relation to AF_RDS, AF_IUCV or AF_VSOCK.  See RFC 7609
              IBM's Shared Memory Communications over RDMA (SMC-R)
              Protocol⟩ for details
              regarding SMC-R.  See SMC-D Reference Information 
              D/index.html⟩ for details regarding SMC-D.

       AF_XDP XDP (express data path) interface (since Linux 4.18).  See
              Documentation/networking/af_xdp.rst in the Linux kernel
              source tree for details.

SEE ALSO         top

       socket(2), socket(7)

COLOPHON         top

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Linux man-pages 6.9.1          2024-06-11            address_families(7)

Pages that refer to this page: socket(2)socket(7)