jammy (3) ares_set_servers.3.gz

NAME

       ares_set_servers, ares_set_servers_ports - Initialize an ares_channel name servers configuration

SYNOPSIS

       #include <ares.h>

       int ares_set_servers(ares_channel channel, struct ares_addr_node *servers)
       int ares_set_servers_ports(ares_channel channel, 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(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.

       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.

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.

       ARES_ENOTIMP   Changing name servers configuration while queries are outstanding is not implemented.

SEE ALSO

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