NAME

libnutclient_tcp, nutclient_tcp_create_client, nutclient_tcp_is_connected, nutclient_tcp_disconnect, nutclient_tcp_reconnect, nutclient_tcp_set_timeout, nutclient_tcp_get_timeout, nutclient_tcp_get_ssl_caps, nutclient_tcp_is_ssl, nutclient_tcp_create_client_ssl_OpenSSL, nutclient_tcp_set_ssl_config_OpenSSL, nutclient_tcp_create_client_ssl_NSS, nutclient_tcp_set_ssl_config_NSS, nutclient_tcp_set_ssl_try, nutclient_tcp_get_ssl_try, nutclient_tcp_set_ssl_force, nutclient_tcp_get_ssl_force, nutclient_tcp_set_ssl_certverify, nutclient_tcp_get_ssl_certverify, nutclient_tcp_set_ssl_capath, nutclient_tcp_get_ssl_capath, nutclient_tcp_set_ssl_cafile, nutclient_tcp_get_ssl_cafile, nutclient_tcp_set_ssl_certfile, nutclient_tcp_get_ssl_certfile, nutclient_tcp_set_ssl_keyfile, nutclient_tcp_get_ssl_keyfile, nutclient_tcp_set_ssl_keypass, nutclient_tcp_get_ssl_keypass, nutclient_tcp_set_ssl_certstore_path, nutclient_tcp_get_ssl_certstore_path, nutclient_tcp_set_ssl_certstore_prefix, nutclient_tcp_get_ssl_certstore_prefix, nutclient_tcp_set_ssl_certident_name, nutclient_tcp_get_ssl_certident_name, nutclient_tcp_set_ssl_certhost_name, nutclient_tcp_get_ssl_certhost_name - TCP protocol related function for Network UPS Tools high-level client access library

SYNOPSIS

Note
Two NUT websites

This version of the page reflects NUT release v2.8.5 with codebase commited 0e051f9f6 at 2026-04-07T11:40:11+02:00

Options, features and capabilities in current development (and future releases) are detailed on the main site and may differ from ones described here.

 
        #include <nutclient.h>
        #include <cstdint> /* uint16_t */
        #include <ctime> /* time_t */

        typedef NUTCLIENT_t NUTCLIENT_TCP_t;

        NUTCLIENT_TCP_t nutclient_tcp_create_client(
                const char* host, uint16_t port);

        int nutclient_tcp_is_connected(NUTCLIENT_TCP_t client);

        void nutclient_tcp_disconnect(NUTCLIENT_TCP_t client);

        int nutclient_tcp_reconnect(NUTCLIENT_TCP_t client);

        void nutclient_tcp_set_timeout(NUTCLIENT_TCP_t client, time_t timeout);

        time_t nutclient_tcp_get_timeout(NUTCLIENT_TCP_t client);

        /* SSL (NUT STARTTLS) support, behavior may be build-dependent
         * (none/OpenSSL/NSS): */

        /* Capabilities of this build, bitmask: */
        #define UPSCLI_SSL_CAPS_NONE    0       /* No ability to use SSL */
        #define UPSCLI_SSL_CAPS_OPENSSL 1       /* Can use OpenSSL-specific setup */
        #define UPSCLI_SSL_CAPS_NSS     2       /* Can use Mozilla NSS-specific setup */
        int nutclient_tcp_get_ssl_caps(void);

        /* Is the specified client currently connected in SSL mode? */
        int nutclient_tcp_is_ssl(NUTCLIENT_TCP_t client);

        NUTCLIENT_TCP_t nutclient_tcp_create_client_ssl_OpenSSL(
                const char* host, uint16_t port, int try_ssl,
                int force_ssl, int certverify,
                const char *ca_path, const char *ca_file,
                const char *cert_file, const char *key_file, const char *key_pass);

        void nutclient_tcp_set_ssl_config_OpenSSL(NUTCLIENT_TCP_t client,
                int force_ssl, int certverify,
                const char *ca_path, const char *ca_file,
                const char *cert_file, const char *key_file, const char *key_pass);

        NUTCLIENT_TCP_t nutclient_tcp_create_client_ssl_NSS(
                const char* host, uint16_t port, int try_ssl,
                int force_ssl, int certverify,
                const char *certstore_path, const char *certstore_pass,
                const char *certstore_prefix,
                const char *certhost_name,
                const char *certident_name);

        void nutclient_tcp_set_ssl_config_NSS(NUTCLIENT_TCP_t client,
                int force_ssl, int certverify,
                const char *certstore_path, const char *certstore_pass,
                const char *certstore_prefix,
                const char *certhost_name,
                const char *certident_name);

        /* Individual SSL option getters/setters: */

        void nutclient_tcp_set_ssl_try(NUTCLIENT_TCP_t client, int try_ssl);
        int nutclient_tcp_get_ssl_try(NUTCLIENT_TCP_t client);

        void nutclient_tcp_set_ssl_force(NUTCLIENT_TCP_t client, int force_ssl);
        int nutclient_tcp_get_ssl_force(NUTCLIENT_TCP_t client);

        void nutclient_tcp_set_ssl_certverify(NUTCLIENT_TCP_t client, int certverify);
        int nutclient_tcp_get_ssl_certverify(NUTCLIENT_TCP_t client);

        /* OpenSSL (PEM): Trusted CA directory: */
        void nutclient_tcp_set_ssl_capath(NUTCLIENT_TCP_t client, const char* ca_path);
        const char* nutclient_tcp_get_ssl_capath(NUTCLIENT_TCP_t client);

        /* Trusted CA file: */
        void nutclient_tcp_set_ssl_cafile(NUTCLIENT_TCP_t client, const char* ca_file);
        const char* nutclient_tcp_get_ssl_cafile(NUTCLIENT_TCP_t client);

        /* Client certificate (public): */
        void nutclient_tcp_set_ssl_certfile(NUTCLIENT_TCP_t client, const char* cert_file);
        const char* nutclient_tcp_get_ssl_certfile(NUTCLIENT_TCP_t client);

        /* Client key (private): */
        void nutclient_tcp_set_ssl_keyfile(NUTCLIENT_TCP_t client, const char* key_file);
        const char* nutclient_tcp_get_ssl_keyfile(NUTCLIENT_TCP_t client);

        /* OpenSSL and NSS: Client key (private): */
        void nutclient_tcp_set_ssl_keypass(NUTCLIENT_TCP_t client, const char* key_pass);
        const char* nutclient_tcp_get_ssl_keypass(NUTCLIENT_TCP_t client);

        void nutclient_tcp_set_ssl_certstore_path(NUTCLIENT_TCP_t client,
                const char* certstore_path);
        const char* nutclient_tcp_get_ssl_certstore_path(NUTCLIENT_TCP_t client);

        void nutclient_tcp_set_ssl_certstore_prefix(NUTCLIENT_TCP_t client,
                const char* certstore_prefix);
        const char* nutclient_tcp_get_ssl_certstore_prefix(NUTCLIENT_TCP_t client);

        void nutclient_tcp_set_ssl_certident_name(NUTCLIENT_TCP_t client,
                const char* certident_name);
        const char* nutclient_tcp_get_ssl_certident_name(NUTCLIENT_TCP_t client);

        void nutclient_tcp_set_ssl_certhost_name(NUTCLIENT_TCP_t client,
                const char* certhost_name);
        const char* nutclient_tcp_get_ssl_certhost_name(NUTCLIENT_TCP_t client);

DESCRIPTION

These functions allow to manage connections to upsd(8) using NUT TCP protocol.

  • The nutclient_tcp_create_client() function create the NUTCLIENT_TCP_t context and intend to connect to upsd at host and port.

    The context must be freed by nutclient_destroy().

    • host can be a sever name or a valid IPv4 or IPv6 address like "localhost", "127.0.0.1" or "::1".

    • port is a valid TCP port, generally 3493.

  • The nutclient_tcp_is_connected() function test if the connection is valid.

  • The nutclient_tcp_disconnect() function force to disconnect the specified connection.

  • The nutclient_tcp_reconnect() function force to reconnect a connection, disconnecting it if needed.

  • The nutclient_tcp_set_timeout() function set the timeout duration for I/O operations.

  • The nutclient_tcp_get_timeout() function retrieve the timeout duration for I/O operations.

    timeout values are specified in seconds, use negative values for blocking.

SEE ALSO

libnutclient(3) libnutclient_general(3)