ARES_SET_SERVERS(3) Introduction to Library Functions ARES_SET_SERVERS(3)
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.
5 March 2010 ARES_SET_SERVERS(3)
