dhcpclib.html

Vxworks API操作系统和驱动程序设计API。压缩的HTML文件

<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK if release scheduled, or ERROR otherwise.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_dhcpcLib_BAD_COOKIE</b>, <b>S_dhcpcLib_NOT_INITIALIZED</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./dhcpcLib.html#top">dhcpcLib</a></b>

<hr>
<a name="dhcpcInformGet"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>dhcpcInformGet(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>dhcpcInformGet(&nbsp;)</strong> - obtain additional configuration parameters with DHCP</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS dhcpcInformGet
    (
    void * pCookie,           /* identifier returned by dhcpcInit() */
    char * pAddrString,       /* known address assigned to client */
    BOOL   syncFlag           /* synchronous or asynchronous execution? */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine uses DHCP to retrieve additional configuration parameters for
a client with the externally configured network address given by the
<i>pAddrString</i> parameter. It sends an INFORM message and waits for a reply
following the process described in RFC 2131. The <i>pCookie</i> argument contains
the return value of an earlier <b><a href="./dhcpcLib.html#dhcpcInit">dhcpcInit</a>(&nbsp;)</b> call and is used to access the
resulting configuration. Unlike the <b><a href="./dhcpcLib.html#dhcpcBind">dhcpcBind</a>(&nbsp;)</b> call, this routine does not
establish a lease with a server.
<p>
The <i>syncFlag</i> parameter specifies whether the message exchange started by 
this routine will execute synchronously or asynchronously.  An asynchronous 
execution will return after sending the initial message, but a synchronous 
execution will only return once the process completes.
<p>
When a server responds with an acknowledgement message, any event hook
provided will be called to process the configuration parameters.  The hook
is also called if the message exchange fails.  The results of an asynchronous
execution are not available unless an event hook is installed.
<p>
</blockquote><h4>NOTE</h4><blockquote><p>
This routine is designed as an alternative to the <b><a href="./dhcpcLib.html#dhcpcBind">dhcpcBind</a>(&nbsp;)</b> routine.
It should not be used for any <b><a href="./dhcpcLib.html#dhcpcInit">dhcpcInit</a>(&nbsp;)</b> identifer corresponding to an
active or pending lease.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK if routine completes, or ERROR otherwise.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_dhcpcLib_BAD_COOKIE</b>, <b>S_dhcpcLib_NOT_INITIALIZED</b>, <b>S_dhcpcLib_BAD_OPTION</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./dhcpcLib.html#top">dhcpcLib</a></b>

<hr>
<a name="dhcpcShutdown"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>dhcpcShutdown(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>dhcpcShutdown(&nbsp;)</strong> - disable DHCP client library</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS dhcpcShutdown (void)</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine schedules the lease monitor task to clean up memory and exit,
after releasing all currently active leases.  The network boot device
will be disabled if the DHCP client was used to obtain the VxWorks boot 
parameters and the resulting lease is still active.  Any other interfaces 
using the addressing information from leases set for automatic configuration
will also be disabled.  Notification of a disabled interface will not occur
unless an event hook has been installed.  After the processing started by
this request completes, the DHCP client library is unavailable until 
restarted with the <b><a href="./dhcpcLib.html#dhcpcLibInit">dhcpcLibInit</a>(&nbsp;)</b> routine.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK if shutdown scheduled, or ERROR otherwise.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_dhcpcLib_NOT_INITIALIZED</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./dhcpcLib.html#top">dhcpcLib</a></b>

<hr>
<a name="dhcpcOptionGet"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>dhcpcOptionGet(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>dhcpcOptionGet(&nbsp;)</strong> - retrieve an option provided to a client and store in a buffer</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS dhcpcOptionGet
    (
    void * pCookie,           /* identifier returned by dhcpcInit() */
    int    option,            /* RFC 2132 option tag */
    int *  pLength,           /* size of provided buffer and data returned */
    char * pBuf               /* location for option data */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine retrieves the data for a specified option from a lease
indicated by the <i>pCookie</i> parameter. The <i>option</i> parameter specifies
an option tag as defined in RFC 2132. See the <b>dhcp/dhcp.h</b> include file
for a listing of defined aliases for the available option tags. This
routine will not accept the following <i>option</i> values, which are either
used by the server for control purposes or only supplied by the client:
<p>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_PAD_TAG</b><br>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_REQUEST_IPADDR_TAG</b><br>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_OPT_OVERLOAD_TAG</b><br>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_MSGTYPE_TAG</b><br>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_REQ_LIST_TAG</b><br>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_MAXMSGSIZE_TAG</b><br>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_CLASS_ID_TAG</b><br>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_CLIENT_ID_TAG</b><br>
&nbsp;&nbsp;&nbsp;&nbsp;<b>_DHCP_END_TAG</b>
<p>
If the option is found, the data is stored in the provided buffer, up to
the limit specified in the <i>pLength</i> parameter.  The option is not available
if the DHCP client is not in the bound state or if the server did not
provide it.  After returning, the <i>pLength</i> parameter indicates the amount
of data actually retrieved. The provided buffer may contain IP addresses
stored in network byte order. All other numeric values are stored in host
byte order.  See RFC 2132 for specific details on the data retrieved. 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK if option available, or ERROR otherwise.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_dhcpcLib_BAD_COOKIE</b>, <b>S_dhcpcLib_NOT_INITIALIZED</b>, <b>S_dhcpcLib_NOT_BOUND</b>,<br>
&nbsp;<b>S_dhcpcLib_OPTION_NOT_PRESENT</b>
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./dhcpcLib.html#top">dhcpcLib</a></b>, <b><a href="./dhcpcCommonLib.html#dhcpcOptionSet">dhcpcOptionSet</a>(&nbsp;)</b>

<hr>
<a name="dhcpcServerGet"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>dhcpcServerGet(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>dhcpcServerGet(&nbsp;)</strong> - retrieve the current DHCP server</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS dhcpcServerGet
    (
    void *           pCookie,    /* identifier returned by dhcpcInit() */
    struct in_addr * pServerAddr /* location for address of server */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the DHCP server that supplied the configuration
parameters for the lease specified by the <i>pCookie</i> argument.  This 
information is available only if the lease is in the bound state.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK if in bound state and server available, or ERROR otherwise.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_dhcpcLib_BAD_COOKIE</b>, <b>S_dhcpcLib_NOT_INITIALIZED</b>, <b>S_dhcpcLib_NOT_BOUND</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./dhcpcLib.html#top">dhcpcLib</a></b>

<hr>
<a name="dhcpcTimerGet"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>dhcpcTimerGet(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>dhcpcTimerGet(&nbsp;)</strong> - retrieve current lease timers</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS dhcpcTimerGet
    (
    void * pCookie,           /* identifier returned by dhcpcInit() */
    int *  pT1,               /* time until lease renewal */
    int *  pT2                /* time until lease rebinding */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the number of clock ticks remaining on the timers
governing the DHCP lease specified by the <i>pCookie</i> argument.  This 
information is only available if the lease is in the bound state.
Therefore, this routine will return ERROR if a BOOTP reply was accepted.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK if in bound state and values available, or ERROR otherwise.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_dhcpcLib_BAD_COOKIE</b>, <b>S_dhcpcLib_NOT_INITIALIZED</b>, <b>S_dhcpcLib_NOT_BOUND</b>, <br>
&nbsp;<b>S_dhcpcLib_OPTION_NOT_PRESENT</b>,&nbsp;<b>S_dhcpcLib_TIMER_ERROR</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./dhcpcLib.html#top">dhcpcLib</a></b>

<hr>
<a name="dhcpcParamsGet"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>dhcpcParamsGet(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>dhcpcParamsGet(&nbsp;)</strong> - retrieve current configuration parameters</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS dhcpcParamsGet
    (
    void *              pCookie,   /* identifier returned by dhcpcInit() */
    struct dhcp_param * pParamList /* requested parameters */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine copies the current configuration parameters for the lease
specified by the <i>pCookie</i> argument to the user-supplied and allocated 
<b>dhcp_param</b> structure referenced in <i>pParamList</i>.  Within this structure,  
defined in <b>h/dhcp/dhcpc.h</b>, you should supply buffer pointers for the 
parameters that interest you.  Set all other structure members to zero.  
When <b><a href="./dhcpcLib.html#dhcpcParamsGet">dhcpcParamsGet</a>(&nbsp;)</b> returns, the buffers you specified in the submitted 
<b>dhcpc_param</b> structure will contain the information you requested.  
This assumes that the specified lease is in the bound state and that 
DHCP knows that the lease parameters are good.
<p>
</blockquote><h4>NOTE</h4><blockquote><p>
The <b>temp_sname</b> and <b>temp_file</b> members of the <b>dhcp_param</b> 
structure are for internal use only.  They reference temporary buffers for 
options that are passed using the <b>sname</b> and <b>file</b> members.  Do not 
request either <b>temp_sname</b> or <b>temp_file</b>.  Instead, request either 
<b>sname</b> or <b>file</b> if you want those parameters.  
<p>
Many of the parameters within the user-supplied structure use one of the 
following secondary data types: <b>struct in_addrs</b>, <b>struct u_shorts</b>, and 
<b>struct vendor_list</b>.  Each of those structures accepts a length designation 
and a data pointer.  For the first two data types, the <b>num</b> member indicates 
the size of the buffer in terms of the number of underlying elements.  For 
example, the <b>STATIC_ROUTE</b> option returns one or more IP address pairs.  Thus, 
setting the <b>num</b> member to 2 in the <b>static_route</b> entry would indicate that 
the corresponding buffer contained 16 bytes.  By contrast, the <b>len</b> member 
in the struct <b>vendor_list</b> data type consists of the buffer size, in bytes.
See RFC 1533 for specific details on the types of data for each option. 
<p>
On return, each of the length designators are set to indicate the amount of
data returned.  For instance, the <b>num</b> member in the <b>static_route</b> entry could
be set to 1 to indicate that only one IP address pair of 8 bytes was 
available.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK if in bound state, or ERROR otherwise.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_dhcpcLib_BAD_COOKIE</b>, <b>S_dhcpcLib_NOT_INITIALIZED</b>, <b>S_dhcpcLib_NOT_BOUND</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./dhcpcLib.html#top">dhcpcLib</a></b>

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