= nng_sockaddr(5)
//
// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
//
// This document is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt).  A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//

== NAME

nng_sockaddr - socket address

== SYNOPSIS

[source, c]
----
#include <nng/nng.h>

typedef union nng_sockaddr {
    uint16_t            s_family;
    nng_sockaddr_ipc    s_ipc;
    nng_sockaddr_inproc s_inproc;
    nng_sockaddr_in     s_in;
    nng_sockaddr_in6    s_in6;
    nng_sockaddr_zt     s_zt;
} nng_sockaddr;

enum sockaddr_family {
    NNG_AF_UNSPEC = 0,
    NNG_AF_INPROC = 1,
    NNG_AF_IPC    = 2,
    NNG_AF_INET   = 3,
    NNG_AF_INET6  = 4,
    NNG_AF_ZT     = 5,
};
----

== DESCRIPTION

(((socket, address)))(((address, socket)))
An `nng_sockaddr` is a structure used for
representing the addresses used by underlying transports, such as TCP/IP
addresses, IPC paths, and so forth.

****
The name `sockaddr` is based on its similarity with POSIX `struct sockaddr`,
but in the _nng_ library, these addresses are more closely affiliated with
instances of xref:nng_pipe.5.adoc[`nng_pipe`]
than of xref:nng_socket.5.adoc[`nng_socket`].
The naming confusion is unfortunate.
****

This structure is actually a union, with different members for different
types of addresses.

Every member structure has as its first element a `uint16_t` field
containing the "`((address family))`".
This overlaps the `s_family` member of the union, and indicates which
specific member should be used.

The values of `s_family` are as follows:

[horizontal]
`NNG_AF_UNSPEC`:: Invalid address, no other valid fields.
`NNG_AF_INPROC`:: Address for intraprocess communication (xref:nng_inproc.7.adoc[nng_inproc(7)]).  The `s_inproc` member is valid.
`NNG_AF_IPC`:: Address for interprocess communication (xref:nng_ipc.7.adoc[nng_ipc(7)]).  The `s_path` member is valid.
`NNG_AF_INET`:: Address for TCP/IP (v4) communication.  The `s_in` member is valid.
`NNG_AF_INET6`:: Address for TCP/IP (v6) communication.  The `s_in6` member is valid.
`NNG_AF_ZT`:: Address for ZeroTier transport (xref:nng_zerotier.7.adoc[nng_zerotier(7)]).  The `s_zt` member is valid.

Please see the manual pages for each individual type for more information.

== SEE ALSO

[.text-left]
xref:nng_sockaddr_in.5.adoc[nng_sockaddr_in(5)],
xref:nng_sockaddr_in6.5.adoc[nng_sockaddr_in6(5)],
xref:nng_sockaddr_inproc.5.adoc[nng_sockaddr_inproc(5)],
xref:nng_sockaddr_ipc.5.adoc[nng_sockaddr_ipc(5)],
xref:nng_sockaddr_zt.5.adoc[nng_sockaddr_zt(5)],
xref:nng.7.adoc[nng(7)]