= libnng(3)
//
// Copyright 2024 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
// Copyright 2019 Devolutions <info@devolutions.net>
// Copyright 2020 Dirac Research <robert.bielik@dirac.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

libnng - nanomsg next generation library

=== Connection Management

The following functions are used with either listeners, or dialers.
Listeners accept incoming connection requests, and dialers make them.

|===
|xref:nng_dial.3.adoc[nng_dial()]|create and start dialer
|xref:nng_dialer_close.3.adoc[nng_dialer_close()]|close dialer
|xref:nng_dialer_create.3.adoc[nng_dialer_create()]|create dialer
|xref:nng_dialer_get.3.adoc[nng_dialer_get()]|get dialer option
|xref:nng_dialer_id.3.adoc[nng_dialer_id()]|get numeric dialer identifier
|xref:nng_dialer_set.3.adoc[nng_dialer_set()]|set dialer option
|xref:nng_dialer_start.3.adoc[nng_dialer_start()]|start dialer
|xref:nng_listen.3.adoc[nng_listen()]|create and start listener
|xref:nng_listener_close.3.adoc[nng_listener_close()]|close listener
|xref:nng_listener_create.3.adoc[nng_listener_create()]|create listener
|xref:nng_listener_get.3.adoc[nng_listener_get()]|get listener option
|xref:nng_listener_id.3.adoc[nng_listener_id()]|get numeric listener identifier
|xref:nng_listener_set.3.adoc[nng_listener_set()]|set listener option
|xref:nng_listener_start.3.adoc[nng_listener_start()]|start listener
|===

=== Asynchronous Operations

Most applications will interact with _NNG_ synchronously; that is that
functions such as xref:nng_send.3.adoc[`nng_send()`] will block the calling
thread until the operation has completed.

NOTE: Synchronous operations which send messages may return before the
message has actually been received, or even transmitted.  Instead, These
functions return as soon as the message was successfully queued for
delivery.

Asynchronous operations behave differently.  These operations are
initiated by the calling thread, but control returns immediately to
the calling thread.  When the operation is subsequently completed (regardless
of whether this was successful or not), then a user supplied function
is executed.

A context structure, an xref:nng_aio.5.adoc[`nng_aio`], is allocated and
associated with each asynchronous operation.
Only a single asynchronous operation may be associated with an
`nng_aio` at any time.

The following functions are used in the asynchronous model:

|===
|xref:nng_aio_reset.3.adoc[nng_aio_reset()]|reset asynchronous I/O operation
|xref:nng_aio_start.3.adoc[nng_aio_start()]|start asynchronous I/O operation
|xref:nng_aio_finish.3.adoc[nng_aio_finish()]|finish asynchronous I/O operation
|xref:nng_aio_get_input.3.adoc[nng_aio_get_input()]|return input parameter
|xref:nng_aio_set_output.3.adoc[nng_aio_set_output()]|set output result
|===


=== Devices, Relays

The following function family is used to create forwarders or relayers
that route messages from one socket to another.

|===
|xref:nng_device.3.adoc[nng_device()]|message forwarding device
|===

=== HTTP Support

The library may be configured with support for HTTP, and this will
be the case if WebSocket support is configured as well.
In this case, it is possible to access functionality to support the creation of
HTTP (and HTTP/S if TLS support is present) servers and clients.

==== HTTP Server Functions

These functions are intended for use with HTTP server applications.

|===
|xref:nng_http_handler_alloc.3http.adoc[nng_http_handler_alloc()]|allocate HTTP server handler
|xref:nng_http_handler_collect_body.3http.adoc[nng_http_handler_collect_body()]|set HTTP handler to collect request body
|xref:nng_http_handler_free.3http.adoc[nng_http_handler_free()]|free HTTP server handler
|xref:nng_http_handler_set_data.3http.adoc[nng_http_handler_set_data()]|set extra data for HTTP handler
|xref:nng_http_handler_set_host.3http.adoc[nng_http_handler_set_host()]|set host for HTTP handler
|xref:nng_http_handler_set_method.3http.adoc[nng_http_handler_set_method()]|set HTTP handler method
|xref:nng_http_handler_set_tree.3http.adoc[nng_http_handler_set_tree()]|set HTTP handler to match trees
|xref:nng_http_server_add_handler.3http.adoc[nng_http_server_add_handler()]|add HTTP server handler
|xref:nng_http_server_del_handler.3http.adoc[nng_http_server_del_handler()]|delete HTTP server handler
|xref:nng_http_server_get_addr.3http.adoc[nng_http_server_get_addr()]|get HTTP server address
|xref:nng_http_server_get_tls.3http.adoc[nng_http_server_get_tls()]|get HTTP server TLS configuration
|xref:nng_http_server_hold.3http.adoc[nng_http_server_hold()]|get and hold HTTP server instance
|xref:nng_http_server_release.3http.adoc[nng_http_server_release()]|release HTTP server instance
|xref:nng_http_server_set_error_file.3http.adoc[nng_http_server_set_error_file()]|set custom HTTP error file
|xref:nng_http_server_set_error_page.3http.adoc[nng_http_server_set_error_page()]|set custom HTTP error page
|xref:nng_http_server_set_tls.3http.adoc[nng_http_server_set_tls()]|set HTTP server TLS configuration
|xref:nng_http_server_res_error.3http.adoc[nng_http_server_res_error()]|use HTTP server error page
|xref:nng_http_server_start.3http.adoc[nng_http_server_start()]|start HTTP server
|xref:nng_http_server_stop.3http.adoc[nng_http_server_stop()]|stop HTTP server
|===

=== TLS Configuration Objects

The following functions are used to manipulate transport layer security
(TLS) configuration objects.  Most of these functions will not be used even
by TLS applications.

NOTE: These functions will only be present if the library has been built
with TLS support.

|===
|xref:nng_tls_config_alloc.3tls.adoc[nng_tls_config_alloc()]|allocate TLS configuration
|xref:nng_tls_config_auth_mode.3tls.adoc[nng_tls_config_auth_mode()]|set authentication mode
|xref:nng_tls_config_ca_chain.3tls.adoc[nng_tls_config_ca_chain()]|set certificate authority chain
|xref:nng_tls_config_ca_file.3tls.adoc[nng_tls_config_ca_file()]|load certificate authority from file
|xref:nng_tls_config_cert_key_file.3tls.adoc[nng_tls_config_cert_key_file()]|load own certificate and key from file
|xref:nng_tls_config_psk.3tls.adoc[nng_tls_config_psk()]|set pre-shared key and identity
|xref:nng_tls_config_own_cert.3tls.adoc[nng_tls_config_own_cert()]|set own certificate and key
|xref:nng_tls_config_free.3tls.adoc[nng_tls_config_free()]|free TLS configuration
|xref:nng_tls_config_server_name.3tls.adoc[nng_tls_config_server_name()]|set remote server name
|===


== SEE ALSO

[.text-left]
xref:nng.7.adoc[nng(7)]
