tfDnsSetUserOption

#include <trsocket.h>

Function Description

This function sets various DNS options, which are outlined below. All of the options supported by tfDnsSetOption are also supported here as well.

optionType

Option to configure. See list of valid options below.
optionValuePtr

Pointer to appropriate data type containing the new value for this option. See list of data types below.
optionLen

The size of the data type pointed to by optionValuePtr.

Option	Data Type	Description
`TM_DNS_OPTION_RETRIES`	`int`	Maximum number of times to re-transmit a DNS request. If there is more than one server, a re-transmission occurs after all servers have been queried.
`TM_DNS_OPTION_CACHE_SIZE`	`int`	Maximum number of entries in the DNS cache. The cache contains both completed and ongoing DNS resolution attempts. This value must be greater than zero.
`TM_DNS_OPTION_TIMEOUT`	`int`	Amount of time (in seconds) to wait before retransmitting a DNS request (value used if there only one server.) - Default value is 5.
`TM_DNS_OPTION_MIN_TIMEOUT`	`int`	Amount of time (in seconds) to wait before retransmitting a DNS request (value used if there is more than one server.) - Default value is 4.
`TM_DNS_OPTION_CACHE_TTL`	`ttUser32Bit`	The maximum amount of time to keep a DNS response in the cache. Note: This value only affects new entries as they are added to the cache â existing entries will not be changed.
`TM_DNS_OPTION_MAX_SOCKETS_ALLOWED`	`ttUser32Bit`	The maximum number of sockets that can be opened for outstanding DNS requests.
`TM_DNS_OPTION_BINDTODEVICE`	`char *`	With this option, the user may now bind the DNS sockets to a specific device. The user may create this binding by passing a valid interface name (char *) as the `optionValuePtr`. The user may remove this binding by passing a NULL string ("") as the `optionValuePtr` parameter. This requires `TM_USE_STRONG_ESL`.