NAME

ares_get_servers, ares_get_servers_ports - Retrieve name servers from an initialized ares_channel

SYNOPSIS

#include <ares.h>

int ares_get_servers(ares_channel channel, struct ares_addr_node **servers)
int ares_get_servers_ports(ares_channel channel, struct ares_addr_port_node **servers)

DESCRIPTION

The ares_get_servers(3) function retrieves name servers configuration from the channel data identified by channel, as a linked list of ares_addr_node structs storing a pointer to the first node at the address specified by servers.

The ares_get_servers_ports(3) function also retrieves any per-server port information that may have been previously configured, returning a linked list of ares_addr_port structures.

Function caller may traverse the returned name server linked list, or may use it directly as suitable input for the ares_set_servers(3) / ares_set_servers_ports(3) functions, but shall not shrink or extend the list on its own.

Each node of the name server linked list is stored in memory dynamically allocated and managed by c-ares. It is the caller's responsibility to free the resulting linked list, using ares_free_data(3) , once the caller does not need it any longer.

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

RETURN VALUES

This function may return any of the following values:

ARES_SUCCESS: The name servers configuration was successfully retrieved
ARES_ENOMEM: The memory was exhausted
ARES_ENODATA: The channel data identified by channel was invalid.

AVAILABILITY

ares_get_servers(3) was added in c-ares 1.7.1; ares_get_servers_ports(3) was added in c-ares 1.11.0.

AUTHOR