noble (3) ares_set_servers.3.gz

NAME

       ares_set_servers,  ares_set_servers_ports  -  Initialize  name  server configuration for an ares channel.
       (deprecated)

SYNOPSIS

       #include <ares.h>

       int ares_set_servers(ares_channel_t *channel,
                            const struct ares_addr_node *servers)

       int ares_set_servers_ports(ares_channel_t *channel,
                                  const struct ares_addr_port_node *servers)

DESCRIPTION

       The ares_set_servers(3) function initializes name servers configuration for the channel  data  identified
       by  channel,  from  a  servers  pointer  to  a linked list of ares_addr_node structs holding name servers
       address data.

       The name server linked list pointer argument may be the result of a previous call to  ares_get_servers(3)
       or a linked list of ares_addr_node structs set up by other means.

       The  ares_set_servers_ports(3) function also allows the specification of UDP and TCP ports to be used for
       communication on a per-server basis.  The provided linked list argument may be the result of  a  previous
       call to ares_get_servers_ports(3) or a linked list of ares_addr_port_node structs set up by other means.

       This  function  replaces  any  potentially  previously configured name servers with the ones given in the
       linked list. So, in order to configure a channel with more than one name server all the desired ones must
       be specified in a single list. Though not recommended, passing NULL will clear all configured servers and
       make an inoperable channel, this may be advantageous for test simulation but unlikely  to  be  useful  in
       production.

       The  function does not take ownership of the linked list argument.  The caller is responsible for freeing
       the linked list when no longer needed.

       This function is capable of handling IPv4  and  IPv6  name  server  addresses  simultaneously,  rendering
       ares_init_options(3) with optmask ARES_OPT_SERVERS functionally obsolete except for IPv4-only name server
       usage.

       As of v1.22.0 this function can be called on an active channel with running queries, previously it  would
       return ARES_ENOTIMP.

RETURN VALUES

       ares_set_servers(3) may return any of the following values:

       ARES_SUCCESS   The name servers configuration was successfully initialized.

       ARES_ENOMEM    The process's available memory was exhausted.

       ARES_ENODATA   The channel data identified by channel was invalid.

       ARES_ENOTINITIALIZED
                      c-ares library initialization not yet performed.

SEE ALSO

       ares_set_servers_csv(3), ares_get_servers(3), ares_init_options(3), ares_dup(3)

NOTES

       Deprecated  functions  as  of  c-ares  1.24.0  due to inability to set all available server options.  Use
       ares_set_servers_csv(3).

AVAILABILITY

       ares_set_servers(3) was added in c-ares 1.7.1; ares_set_servers_ports(3) was added in c-ares 1.11.0.

AUTHOR

       Implementation of this function and associated library internals are based on code, comments and feedback
       provided  in  November and December of 2008 by Daniel Stenberg, Gregor Jasny, Phil Blundell and Yang Tse,
       December 2009 by Cedric Bail, February 2010 by Jakub Hrozek. On March 2010 Yang Tse shuffled all the bits
       and this function popped out.
       Copyright 1998 by the Massachusetts Institute of Technology.
       Copyright (C) 2008-2010 by Daniel Stenberg

                                                  5 March 2010                               ARES_SET_SERVERS(3)