DhcpV4GetOptionValue function (dhcpsapi.h)

Article
10/13/2021

The DhcpV4GetOptionValue function retrieves a DHCP option value (the option code and associated data) for a particular scope. This function extends the functionality provided by DhcpGetOptionValueV5 by allowing the caller to specify a policy for the option.

Syntax

DWORD DHCP_API_FUNCTION DhcpV4GetOptionValue(
  [in, optional] LPWSTR                   ServerIpAddress,
  [in]           DWORD                    Flags,
  [in]           DHCP_OPTION_ID           OptionID,
  [in, optional] LPWSTR                   PolicyName,
  [in, optional] LPWSTR                   VendorName,
  [in]           LPDHCP_OPTION_SCOPE_INFO ScopeInfo,
  [out]          LPDHCP_OPTION_VALUE      *OptionValue
);

Parameters

[in, optional] ServerIpAddress

Pointer to a null-terminated Unicode string that represents the IP address or hostname of the DHCP server.

[in] Flags

Indicates whether the option is for a specific or default vendor.

Flags	Meaning
0x00000000	The option value is retrieved for a default vendor.
DHCP_FLAGS_OPTION_IS_VENDOR 0x00000003	The option value is retrieved for a specific vendor. The vendor is in VendorName.

[in] OptionID

DHCP_OPTION_ID structure that specifies the unique option code for the option value to retrieve. A complete list of standard DHCP and BOOTP option codes can be found at http://www.ietf.org/rfc/rfc2132.txt

[in, optional] PolicyName

A null-terminated Unicode string that represents the name of the policy inside the subnet of the option value to retrieve. The subnet is identified by the SubnetScopeInfo member of ScopeInfo.

[in, optional] VendorName

A null-terminated Unicode string that represents the vendor of the option. This parameter is optional, and should be NULL when Flags is not DHCP_FLAGS_OPTION_IS_VENDOR. If the vendor is not specified, the option value is returned for the default vendor.

[in] ScopeInfo

DHCP_OPTION_SCOPE_INFO structure that contains information on the scope of the option value to retrieve.

[out] OptionValue

Pointer to a DHCP_OPTION_DATA structure that contains the data value corresponding to the DHCP option code specified by OptionID.

Return value

If the function succeeds, it returns ERROR_SUCCESS.

If the function fails, it returns one of the following or an error code from DHCP Server Management API Error Codes.

Value	Meaning
ERROR_INVALID_PARAMETER	One or more of the parameters were invalid.
ERROR_DHCP_SUBNET_NOT_PRESENT	The specified IPv4 subnet does not exist.
ERROR_DHCP_CLASS_NOT_FOUND	The class name being used is unknown or incorrect.
ERROR_DHCP_POLICY_NOT_FOUND	The specified policy name does not exist.
ERROR_DHCP_OPTION_NOT_PRESENT	The specified option definition does not exist on the DHCP server database.

Remarks

OptionValue should be free using DhcpRpcFreeMemory.

Requirements

Requirement	Value
Minimum supported client	None supported
Minimum supported server	Windows Server 2012 [desktop apps only]
Target Platform	Windows
Header	dhcpsapi.h
Library	Dhcpsapi.lib
DLL	Dhcpsapi.dll