<div class="content"><p> </p><p>The <b>R_DhcpGetOptionValue</b> method retrieves the option
value for a specific option associated with the default <span><a href="a9d6a415-4de6-4058-befe-ca2e42764485#gt_713c7395-9431-4d67-bab1-a069ae7461e2" data-linktype="relative-path">user
class</a></span> and <span><a href="a9d6a415-4de6-4058-befe-ca2e42764485#gt_45d20b00-7166-4f94-b679-4cc5a7835a3a" data-linktype="relative-path">vendor class</a></span> pair.
The values can be retrieved from the default, server, <span><a href="a9d6a415-4de6-4058-befe-ca2e42764485#gt_128cd76b-eecb-41e6-96f7-f73c2bf9235a" data-linktype="relative-path">scope</a></span>, <span><a href="a9d6a415-4de6-4058-befe-ca2e42764485#gt_04286a2c-1484-44d0-9854-7c57c8b4118c" data-linktype="relative-path">multicast
scope</a></span>, or <span><a href="a9d6a415-4de6-4058-befe-ca2e42764485#gt_4e525014-9425-4eb0-9141-61189c4f04f9" data-linktype="relative-path">reservation</a></span> level on
the DHCPv4 server. The <i>ScopeInfo</i> parameter defines the level from which
the option value needs to be retrieved. The caller of this function can free
the memory pointed to by the <i>OptionValue</i> parameter by calling the
function midl_user_free (section <span><a href="a7e5f2d1-04b7-4363-bdc0-76a1099664eb" data-linktype="relative-path">3</a></span>).</p><dl>
<dd>
<div><pre> DWORD R_DhcpGetOptionValue(
   [in, unique, string] DHCP_SRV_HANDLE ServerIpAddress,
   [in] DHCP_OPTION_ID OptionID,
   [in, ref] LPDHCP_OPTION_SCOPE_INFO ScopeInfo,
   [out] LPDHCP_OPTION_VALUE* OptionValue
 );
</pre></div>
</dd></dl><p><b>ServerIpAddress: </b>The IP address/host name of
the DHCP server. This parameter is unused.</p><p><b>OptionID: </b>This is of type <span><a href="4a0bb785-ceec-4f7a-b4a7-64555f6e0b62" data-linktype="relative-path">DHCP_OPTION_ID (section 2.2.1.2.3)</a></span>,
containing the option identifier for the option being retrieved.</p><p><b>ScopeInfo: </b>This is a pointer to a <span><a href="177415f4-85c1-4496-a414-4938dca18b93" data-linktype="relative-path">DHCP_OPTION_SCOPE_INFO (section 2.2.1.2.41)</a></span>
structure that contains information describing the level (that is, default,
server, scope, multicast scope, or reservation level) from which the option value
is retrieved.</p><p><b>OptionValue: </b>This is a pointer of type <span><a href="fa30c949-e063-4aea-b839-a6210e77741e" data-linktype="relative-path">LPDHCP_OPTION_VALUE</a></span>
in which the option value is retrieved corresponding to the <i>OptionID</i>
parameter. For Dynamic <span><a href="a9d6a415-4de6-4058-befe-ca2e42764485#gt_604dcfcd-72f5-46e5-85c1-f3ce69956700" data-linktype="relative-path">DNS</a></span> update settings,
see section <span><a href="c12007e1-f28d-43b2-9994-5c965f0e6bab" data-linktype="relative-path">3.3.1</a></span>.</p><p><b>Return Values: </b>A 32-bit unsigned integer value
that indicates return status. A return value ERROR_SUCCESS (0x00000000) indicates
that the operation was completed successfully, else it contains a Win32 error
code, as specified in <span><a href="../ms-erref/1bc92ddf-b79e-413c-bbaa-99a5281a6c90" data-linktype="relative-path">[MS-ERREF]</a></span>.
This error code value can correspond to a DHCP-specific failure, which takes a
value between 20000 and 20099, or any generic failure.</p><dl>
<dd>
<table><thead>
  <tr>
   <th>
   <p>Return value/code</p>
   </th>
   <th>
   <p>Description</p>
   </th>
  </tr>
 </thead><tbody><tr>
  <td>
  <p>0x00000000</p>
  <p>ERROR_SUCCESS</p>
  </td>
  <td>
  <p>The call was successful.</p>
  </td>
 </tr><tr>
  <td>
  <p>0x00004E25</p>
  <p>ERROR_DHCP_SUBNET_NOT_PRESENT</p>
  </td>
  <td>
  <p>The specified IPv4 subnet does not exist on the DHCP server.</p>
  </td>
 </tr><tr>
  <td>
  <p>0x00004E2A</p>
  <p>ERROR_DHCP_OPTION_NOT_PRESENT</p>
  </td>
  <td>
  <p>The specified option definition does not exist on the
  DHCP server database.</p>
  </td>
 </tr><tr>
  <td>
  <p>0x00004E32</p>
  <p>ERROR_DHCP_NOT_RESERVED_CLIENT</p>
  </td>
  <td>
  <p>The specified DHCP client is not a reserved client.</p>
  </td>
 </tr></tbody></table>
</dd></dl><p>The opnum field value for this method is 13.</p><p>When processing this call, the DHCP server MUST do the
following:</p><ul><li><p><span><span> 
</span></span>Validate whether this method is authorized for read access per
section <span><a href="baec2112-1146-4c42-b77e-b706e170a590" data-linktype="relative-path">3.5.4</a></span>. If not,
return the error ERROR_ACCESS_DENIED.</p>
</li><li><p><span><span> 
</span></span>If the <i>ScopeInfo</i> parameter contains DhcpDefaultOptions,
iterate though the server Abstract Data Model (ADM) element <b>DHCPv4OptionDefList</b>
and retrieve the <b>DHCPv4ClassedOptDefList</b> ADM element corresponding to
the <b>DHCPv4OptionDef</b> ADM element entry if the <b>UserClass</b> and <b>VendorClass</b>
ADM element fields are NULL. If the <b>DHCPv4ClassedOptDefList</b> ADM element
is not found, return ERROR_DHCP_OPTION_NOT_PRESENT; else, iterate through the <b>DHCPv4ClassedOptDefList</b>
ADM element, and if there is no <b>DHCPv4ClassedOptDef</b> ADM element entry
corresponding to the <b>OptionID</b> parameter, return
ERROR_DHCP_OPTION_NOT_PRESENT; otherwise, allocate the memory for <i>OptionValue</i>,
copy the information in the <b>DHCPv4ClassedOptDef</b> ADM element in the <i>OptionValue</i>
parameter, and return it to the caller.</p>
</li><li><p><span><span> 
</span></span>If the <i>ScopeInfo</i> parameter contains DhcpGlobalOptions,
iterate through the server ADM element <b>DHCPv4ServerOptValueList</b> and
retrieve the <b>DHCPv4OptionValue</b> ADM element entry if the <b>UserClass</b>
and <b>VendorClass</b> ADM element fields are NULL. If the <b>DHCPv4OptionValue</b>
ADM element is not found, return ERROR_FILE_NOT_FOUND; else, retrieve the <b>DHCPv4ClassedOptValue</b>
ADM element entry corresponding to the <i>OptionID</i> parameter from the <b>DHCPv4OptionValue.DHCPv4ClassedOptValueList</b>
ADM element. If the <b>DHCPv4ClassedOptValue</b> ADM element entry is not
found, return ERROR_FILE_NOT_FOUND; otherwise, allocate the memory for <i>OptionValue</i>,
copy the information in the <b>Value</b> member of <b>DHCPv4ClassedOptValue</b>
ADM element in the <i>OptionValue</i> parameter and return it to the caller.</p>
</li><li><p><span><span> 
</span></span>If the <i>ScopeInfo</i> parameter contains DhcpSubnetOptions,
retrieve the <b>DHCPv4Scope</b> ADM element entry corresponding to the <b>SubnetScopeInfo</b>
member of  the <b>ScopeInfo</b> parameter from the server ADM element <b>DHCPv4ScopesList</b>.
If the <b>DHCPv4Scope</b> ADM element entry is not found, return
ERROR_DHCP_SUBNET_NOT_PRESENT. Else, iterate through the <b>DHCPv4Scope.DHCPv4ScopeOptValuesList</b>
ADM element and retrieve the <b>DHCPv4OptionValue</b> ADM element entry if the <b>UserClass</b>
and <b>VendorClass</b> ADM element fields are NULL. If the <b>DHCPv4OptionValue</b>
ADM element is not found, return ERROR_FILE_NOT_FOUND, else, retrieve the <b>DHCPv4ClassedOptValue</b>
ADM element entry corresponding to the <i>OptionID</i> parameter from the <b>DHCPv4OptionValue.DHCPv4ClassedOptValueList</b>
ADM element. If the <b>DHCPv4ClassedOptValue</b> ADM element entry is not
found, return ERROR_FILE_NOT_FOUND. Otherwise, allocate the memory for <i>OptionValue</i>,
copy the information in <b>Value</b> member of <b>DHCPv4ClassedOptValue</b> ADM
element in the <b>OptionValue</b> parameter, and return it to the caller.</p>
</li><li><p><span><span> 
</span></span>If the <i>ScopeInfo</i> parameter contains DhcpReservedOptions,
retrieve the <b>DHCPv4Scope</b> ADM element entry from the server ADM element <b>DHCPv4ScopesList</b>
that contains the <b>ReservedIpAddress</b> member of the <i>ReservedScopeInfo</i>
parameter. Retrieve the <b>DHCPv4Reservation</b> ADM element entry from the <b>DHCPv4Scope.DHCPv4ReservationsList</b>
ADM element corresponding to the <b>ReservedIpAddress</b> member. If the <b>ReservedIpAddress</b>
member is not part of any of the <b>DHCPv4Scope</b> ADM element, or if there is
no <b>DHCPv4Reservation</b> ADM element entry corresponding to the <b>ReservedIpAddress</b>,
return ERROR_DHCP_NOT_RESERVED_CLIENT. Else, iterate through the <b>DHCPv4Reservation.DHCPv4ResvOptValuesList</b>
ADM element and retrieve the <b>DHCPv4OptionValue</b> ADM element entry if the <b>UserClass</b>
and <b>VendorClass</b> ADM element fields are NULL. If the <b>DHCPv4OptionValue</b>
ADM element is not found, return ERROR_FILE_NOT_FOUND; else, retrieve the <b>DHCPv4ClassedOptValue</b>
ADM element entry corresponding to the <i>OptionID</i> parameter from the <b>DHCPv4OptionValue.DHCPv4ClassedOptValueList</b>
ADM element. If the <b>DHCPv4ClassedOptValue</b> ADM element entry is not
found, return ERROR_FILE_NOT_FOUND; otherwise, allocate the memory for <i>OptionValue</i>,
copy the information in the <b>Value</b> member of <b>DHCPv4ClassedOptValue</b>
ADM element in the <b>OptionValue</b> parameter and return it to the caller.</p>
</li><li><p><span><span> 
</span></span>If the <i>ScopeInfo</i> parameter contains DhcpMScopeOptions,
retrieve the <b>DHCPv4MScope</b> ADM element entry corresponding to the <b>ScopeInfo</b>
parameter from the server ADM element <b>DHCPv4MScopesList</b>. If the <b>DHCPv4MScope</b>
ADM element entry is not found, return ERROR_DHCP_SUBNET_NOT_PRESENT. Else,
iterate through <b>DHCPv4MScope.DHCPv4MScopeOptValuesList</b> ADM element and
retrieve the <b>DHCPv4OptionValue</b> ADM element entry if the <b>UserClass</b>
and <b>VendorClass</b> ADM element fields are NULL. If the <b>DHCPv4OptionValue</b>
ADM element is not found, return ERROR_FILE_NOT_FOUND; else, retrieve the <b>DHCPv4ClassedOptValue</b>
ADM element entry corresponding to <i>OptionID</i> parameter from the <b>DHCPv4OptionValue.DHCPv4ClassedOptValueList</b>
ADM element. If the <b>DHCPv4ClassedOptValue</b> ADM element entry is not
found, return ERROR_FILE_NOT_FOUND; otherwise, allocate the memory for <i>OptionValue</i>,
copy the information in the <b>Value</b> member of <b>DHCPv4ClassedOptValue</b>
ADM element in the <b>OptionValue</b> parameter and return it to the caller.</p>
</li></ul><p><b>Exceptions Thrown:</b> No exceptions are thrown beyond
those thrown by the underlying RPC protocol <span><a href="../ms-rpce/290c38b1-92fe-4229-91e6-4fc376610c15" data-linktype="relative-path">[MS-RPCE]</a></span>.</p></div>