#include <nng/transport/tcp/tcp.h>
int nng_tcp_register(void);| This documentation is for the TIP (development tree) of NNG and may represent unreleased changes or functionality that is experimental, and is subject to change before release. The latest released version is v1.8.0. See the documentation for v1.8.0 for the most up-to-date information. |
nng_tcp(7)
NAME
nng_tcp - TCP/IP transport
SYNOPSIS
DESCRIPTION
The tcp transport provides communication support between sockets across a TCP/IP network. Both IPv4 and IPv6 are supported when the underlying platform also supports it.
Registration
This transport is generally built-in to the core of NNG, so no extra steps to use it should be necessary.
URI Format
This transport uses URIs using the scheme tcp://, followed by
an IP address or hostname, followed by a colon and finally a
TCP port number.
For example, to contact port 80 on the localhost either of the following URIs
could be used: tcp://127.0.0.1:80 or tcp://localhost:80.
A URI may be restricted to IPv6 using the scheme tcp6://, and may
be restricted to IPv4 using the scheme tcp4://.
Specifying tcp6:// may not prevent IPv4 hosts from being used with
IPv4-in-IPv6 addresses, particularly when using a wildcard hostname with
listeners.
The details of this varies across operating systems.
|
Both tcp6:// and tcp4:// are specific to NNG, and might not
be understood by other implementations.
|
| We recommend using either numeric IP addresses, or names that are specific to either IPv4 or IPv6 to prevent confusion and surprises. |
When specifying IPv6 addresses, the address must be enclosed in
square brackets ([]) to avoid confusion with the final colon
separating the port.
For example, the same port 80 on the IPv6 loopback address (::1) would
be specified as tcp://[::1]:80.
The special value of 0 (INADDR_ANY)
can be used for a listener to indicate that it should listen on all
interfaces on the host.
A short-hand for this form is to either omit the address, or specify
the asterisk (*) character.
For example, the following three URIs are all equivalent,
and could be used to listen to port 9999 on the host:
-
tcp://0.0.0.0:9999 -
tcp://*:9999 -
tcp://:9999
The entire URI must be less than NNG_MAXADDRLEN bytes long.
Socket Address
When using an nng_sockaddr structure,
the actual structure is either of type
nng_sockaddr_in (for IPv4) or
nng_sockaddr_in6 (for IPv6).
Transport Options
The following transport options are supported by this transport, where supported by the underlying platform.