<div class="content"><p> </p><p>The <b>R_DhcpGetOptionInfoV5</b> method retrieves the option
definition of a specific option for a specific user class and vendor class at
the default option level. If the user class or vendor class is not defined, the
option definition is retrieved for the default user class or vendor class. This
is an extension method of <span><a href="d26c2bbe-dcd7-4c12-a49b-5a20690137d9" data-linktype="relative-path">R_DhcpGetOptionInfo (section 3.1.4.11)</a></span>,
which retrieves the option definition of a specific option for the default user
and vendor class. The caller of this function can free the memory pointed to by
<i>OptionInfo</i> by calling the function <b>midl_user_free</b> (see section <span><a href="a7e5f2d1-04b7-4363-bdc0-76a1099664eb" data-linktype="relative-path">3</a></span>).</p><dl>
<dd>
<div><pre> DWORD R_DhcpGetOptionInfoV5(
   [in, unique, string] DHCP_SRV_HANDLE ServerIpAddress,
   [in] DWORD Flags,
   [in] DHCP_OPTION_ID OptionID,
   [in, string, unique] WCHAR* ClassName,
   [in, string, unique] WCHAR* VendorName,
   [out] LPDHCP_OPTION* OptionInfo
 );
</pre></div>
</dd></dl><p><b>ServerIpAddress: </b>The IP address/host name of
the DHCP server. This parameter is unused.</p><p><b>Flags: </b>This is of type <span><a href="../ms-dtyp/262627d8-3418-4627-9218-4ffe110850b2" data-linktype="relative-path">DWORD</a></span>
that specifies that the option definition is retrieved for a specific or
default vendor class.</p><dl>
<dd>
<table><thead>
  <tr>
   <th>
   <p>Value</p>
   </th>
   <th>
   <p>Meaning</p>
   </th>
  </tr>
 </thead><tbody><tr>
  <td>
  <p>DHCP_FLAGS_OPTION_DEFAULT</p>
  <p>0x00000000</p>
  </td>
  <td>
  <p>Option definition is modified for a default vendor
  class.</p>
  </td>
 </tr><tr>
  <td>
  <p>DHCP_FLAGS_OPTION_IS_VENDOR</p>
  <p>0x00000003</p>
  </td>
  <td>
  <p>If a bitwise AND operation with this bitmask yields a
  nonzero value, it indicates that the option definition is retrieved for a
  specific vendor class.</p>
  </td>
 </tr></tbody></table>
</dd></dl><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>ClassName: </b>A pointer to a null-terminated
Unicode string that contains the name of the user class for which the option
definition is retrieved. This parameter is optional. If the <i>ClassName</i>
parameter is not specified, the option definition is retrieved for the default
user class.</p><p><b>VendorName: </b>A pointer to a null-terminated Unicode
string that contains the name of the vendor class for which the option
definition is retrieved. This parameter is optional, and if the vendor class
name is not specified, the option definition is retrieved for the default
vendor class.</p><p><b>OptionInfo: </b>This is a pointer of type <span><a href="855b6a9a-e6e4-4c9d-a732-aadad749ca03" data-linktype="relative-path">DHCP_OPTION (section 2.2.1.2.25)</a></span>
in which the option definition for the option is retrieved.</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>0x00004E2A</p>
  <p>ERROR_DHCP_OPTION_NOT_PRESENT</p>
  </td>
  <td>
  <p>The specified option definition does not exist on DHCP
  server database.</p>
  </td>
 </tr><tr>
  <td>
  <p>0x00004E4C</p>
  <p>ERROR_DHCP_CLASS_NOT_FOUND</p>
  </td>
  <td>
  <p>The class name being used is unknown or incorrect.</p>
  </td>
 </tr></tbody></table>
</dd></dl><p>The opnum field value for this method is 16.</p><p>When processing this call, the DHCP server MUST do the
following:</p><ul><li><p><span><span> 
</span></span>Validate if 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>The <i>Flags</i> parameter MUST pass one of the validations given
in the <i>Flags</i> field description. Otherwise, the method returns
ERROR_INVALID_PARAMETER.</p>
</li><li><p><span><span> 
</span></span>If ClassName is not NULL, retrieve the <b>DHCPv4ClassDef</b>
entry corresponding to the <i>ClassName</i> from the server ADM element <b>DHCPv4ClassDefList</b>.
If the <b>DHCPv4ClassDef</b> entry is not found, return
ERROR_DHCP_CLASS_NOT_FOUND. If <i>ClassName</i> is NULL, it refers to the
default vendor class (see section <span><a href="4aa40625-0f9f-4e89-93a4-e4455bc1cc95" data-linktype="relative-path">3.1.1.9</a></span>).</p>
</li><li><p><span><span> 
</span></span>If VendorName is not NULL, retrieve the <b>DHCPv4ClassDef</b>
entry corresponding to the <i>VendorName</i> from the server ADM element <b>DHCPv4ClassDefList</b>.
If the <b>DHCPv4ClassDef</b> entry is not found, return
ERROR_DHCP_CLASS_NOT_FOUND. If <i>VendorName</i> is NULL, it refers to the
default vendor class (see section 3.1.1.9).</p>
</li><li><p><span><span> 
</span></span>Iterate through the server ADM element <b>DHCPv4OptionDefList</b>
and retrieve <b>DHCPv4OptionDef.DHCPv4ClassedOptDefList</b> corresponding to
the user and vendor class specified by <i>ClassName</i> and <i>VendorName</i>
respectively. If <i>ClassName</i> or <i>VendorName</i> is NULL, it refers to
the default user class or vendor class respectively, as specified in section
3.1.1.9. If there is no <b>DHCPv4OptionDef</b> entry corresponding to the
specified user and vendor classes, return ERROR_DHCP_CLASS_NOT_FOUND.</p>
</li><li><p><span><span> 
</span></span>Iterate through the <b>DHCPv4ClassedOptDefList</b> and if there
is no <b>DHCPv4ClassedOptDef</b> entry corresponding to the <i>OptionID</i>,
return ERROR_DHCP_OPTION_NOT_PRESENT.</p>
</li><li><p><span><span> 
</span></span>Allocate memory to <i>OptionInfo</i>, which is equal to the size
of the data type DHCP_OPTION and to its members as needed by the data in the <b>DHCPv4ClassedOptDef</b>
object. Copy the information in <b>DHCPv4ClassedOptDef</b> in the <i>OptionInfo</i>
structure and return ERROR_SUCCESS 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>