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requests want to add or delete objects or instances.  If this pointer is
NULL, the default MIB tree specified by <b>mib_root_node</b> is used.
<p>
</dl>

</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
&nbsp;N/A
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./subagentLib.html#top">subagentLib</a></b>

<hr>
<a name="snmpMasterHandlerWR"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>snmpMasterHandlerWR</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>snmpMasterHandlerWR</i>(&nbsp;)</strong> - synchronous version of <b><i><a href="./subagentLib.html#snmpMasterHandlerAsync">snmpMasterHandlerAsync</a></i>(&nbsp;)</b></p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>INT_32_T snmpMasterHandlerWR
    (
    OCTET_T *   pMsg,      /* pointer to the message */
    ALENGTH_T   msgl,      /* length of the message */
    IPCSEND_T * pIpcSend,  /* send routine */
    IPCRCV_T *  pIpcRcv,   /* receive routine */
    IPCFREE_T * pIpcFree,  /* free routine */
    IPCAYT_T *  pIpcAyt,   /* status Check Routine */
    PTR_T       ipchandle, /* ipchandle for the IPC scheme used */
    EBUFFER_T * pBuf,      /* buffer to place reply in */
    VBL_T *     pVblist,   /* place to put varbinds */
    PTR_T       user_priv  /* MIB tree identifier */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This function is called to process the control messages received from
subagents when the communication method between master and subagent is
synchronous.
<p>
To process a registration request, this function extracts the objects
from the message and adds them as a group to the master agent's MIB tree.
The actual get, test, and set methods for these objects reside in the
subagent.  To set up local methods for these routines,
<b><i><a href="./subagentLib.html#snmpMasterHandlerAsync">snmpMasterHandlerAsync</a></i>(&nbsp;)</b> uses the function referenced in <i>pIpcSend</i> and
<i>pIpcRcv</i>.
<p>
The methods local to the master agent use <i>pIpcSend</i> to send queries to
the subagent which locally executes the actual method routine for the
object.  The subagent then transmits the results back to the master agent's
public queue.  When the function monitoring this queue sees the query
response, it transfers the message to the master agent's local queue
where the <i>pIpcRcv</i> function is waiting for the response.
<p>
To process a deregistration request, this function extracts a group ID
from the message and removes that group of objects from the master agent's
MIB tree.  It also executes the function in <i>pIpcFree</i> to free any resources
allocated locally to maintain the IPC link with the deregistered subagent.
<p>
The <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> routine returns information using the output
parameters <i>pBuf</i> and <i>pVblist</i> and its function return value.  If the
returned function value indicates success, the master agent sends the
message returned in <i>pBuf</i> to the subagent that sent the registration or
deregistration request.  If the returned value of this function indicates
failure, the master agent silently drops the packet.
<p>
This function as has the ability to return an opcode value, although this
functionality is unused in the shipped version of WindNet SNMP.  In fact,
if <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> were to return an opcode, the current implementation
of the master agent would silently drop the packet.  The possibility
of returning an opcode is supported to make it possible for you to create
subagents that send traps.  In this case, <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> would
return an opcode and a varbind list using the <i>pVblist</i> parameter.  You
could then rewrite <b><i>snmpQueMonitor</i>(&nbsp;)</b>, the master agent function that calls
<b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b>, so that it responds appropriately to the returned
opcode and forwards the contents of <i>pVblist</i> to the SNMP manager.
<p>
Use the <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> parameters as follows:
<dl>
<dt>
<i>pMsg</i>
<dd>

Expects a pointer to an <b>EBUFFER_T</b> structure containing the data part of
the message from the subagent.  The message shows up on the queue as
an <b>SA_MESSAGE_T</b> structure.  The message expected by this parameter is
contained in the <b>mesg</b> member of the <b>SA_MESSAGE_T</b> structure.  To extract
this pointer, you can use the <b>EbufferStart</b> macro defined in defined
in <b>buffer.h</b>.
<p>
<dt>
<i>msgl</i>
<dd>

Expects the length of the message referenced in <i>pMsg</i>.  To retrieve this
length value, use the <b>EBufferUsed</b> macro defined in <b>buffer.h</b>.
<p>
<dt>
<i>pIpcSend</i>
<dd>

Expects a pointer to the function that method routines should use to send
messages to the subagent.  This function must be of the form:
<pre>INT_32_T masterIpcSend
   (
   EBUFFER_T *        pBuf,      /* message to be sent */
   PTR_T              ipchandle  /* address of subagent */
   )
</pre>
If <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> is processing a registration request from the
subagent, it associates this function pointer with the group of objects
it adds to the master agent's MIB tree.  The methods for those objects
call this routine to send a message to the subagent to make a test, get,
or set query against those variables. After using this function to send
the message, the master agent then calls the function referenced in <i>pIpcRcv</i>.
The <i>pIpcRcv</i> function waits on a local queue for a response from the
subagent.  For an example of an <b><i><a href="./masterIoLib.html#masterIpcSend">masterIpcSend</a></i>(&nbsp;)</b> routine, see the
<b><i><a href="./masterIoLib.html#masterIpcSend">masterIpcSend</a></i>(&nbsp;)</b> defined in <b>masterIoLib.c</b>.
<p>
<dt>
<i>ipcRcv</i>
<dd>

Expects a pointer to a function of the form:
<pre>INT_32_T masterIpcRcv
   (
      EBUFFER_T *        pBuf,        /* buffer to receive message */
      PTR_T              ipchandle    /* address of subagent */
   )
</pre>
If <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> is processing a registration request from the
subagent, it associates this function pointer with the group of objects
it adds to the master agent's MIB tree.  The methods for those objects
call this routine to wait on a local queue for a response from the subagent.
For an example of an <b><i><a href="./masterIoLib.html#masterIpcRcv">masterIpcRcv</a></i>(&nbsp;)</b>, see the <b><i><a href="./masterIoLib.html#masterIpcRcv">masterIpcRcv</a></i>(&nbsp;)</b> defined in
<b>masterIoLib.c</b>.
<p>
<dt>
<i>ipcFree</i>
<dd>

Expects a pointer to a function of the form:
<pre>void masterIpcFree ( PTR_T ipchandle )
</pre>
The master agent uses this function to free any resources it allocated to
maintain the IPC link with the subagent.  The master agent calls this
function when a subagent deregisters.
<p>
<dt>
<i>pIpcAyt</i>
<dd>

Expects a pointer to the function the master agent can use to test the
connection with the subagent.  This function must be of the form:
<pre>INT_32_T masterIpcAyt ( PTR_T ipchandle )
</pre>
For an example of such a function, see the <b><i><a href="./masterIoLib.html#masterIpcAyt">masterIpcAyt</a></i>(&nbsp;)</b> defined
in <b>masterIoLib.c</b>.
<p>
<dt>
<i>ipchandle</i>
<dd>

Expects a pointer to the IPC handle used to access the subagent that
sent this message.  In the shipped implementation, this is a pointer
to a message queue.
<p>
<dt>
<i>pBuf</i>
<dd>

Expects a pointer to a previously allocated <b>EBUFFER_T</b>.  This is an output
parameter that <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> uses this to return a reply packet, if
one is generated.  For example, if <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> successfully
processes a registration request, it writes a message to the <b>EBUFFER_T</b>
at <i>pBuf</i>.  This message contains the group ID for the objects just added
to the master agent's MIB tree.  When control returns from
<b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b>, you must transmit this message back to the
subagent, which will store the group ID for use in a deregistration
request.  In the current implementation, <b><i>snmpQueMonitor</i>(&nbsp;)</b> already
handles this for you.
<p>
<dt>
<i>pVblist</i>
<dd>

Expects a pointer to a previously allocated <b>VBL_T</b>.  The intended use of
this parameter is to provide an output vehicle for the varbind list
received in a trap message from a subagent.  Because of the
application-dependent nature of traps, the shipped implementation
of <b><i>snmpQueMonitor</i>(&nbsp;)</b> just drops the packet.  However, if you want to
support traps from your subagents, you can modify <b><i>snmpQueMonitor</i>(&nbsp;)</b> to
check the returned value of <b><i><a href="./subagentLib.html#snmpMasterHandlerWR">snmpMasterHandlerWR</a></i>(&nbsp;)</b> to watch for a
trap message.  You can then use <b><i><a href="./snmpIoLib.html#snmpIoTrapSend">snmpIoTrapSend</a></i>(&nbsp;)</b> to forward the
trap message in <i>pVblist</i> to the SNMP manager.
<p>
<dt>
<i>user_priv</i>
<dd>
 Expects a pointer to the MIB tree from which registration and deregistration
requests want to add or delete objects or instances.  If this pointer is
NULL, the default MIB tree specified by <b>mib_root_node</b> is used. 
</dl>

<p>
If the message is trap request, it is the responsibility of the user
code to acquire any values not specified in the trap message and to send the
trap to the manager.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The opcode from the decoded packet or 0 or -1.
An returned value of 0 indicates an error for which you should just
drop the packet.  A return value of -1 indicates success.
<p>
If this function returns an opcode, a value from 1 to
127, the shipped implementation just drops the packet.  However, to
support traps from the subagent, you could modify <b><i>snmpQueMonitor</i>(&nbsp;)</b> to
note a returned value of <b>SA_TRAP_REQUEST</b> and then forward the varbind
list in <i>pVblist</i> to the SNMP manager.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./subagentLib.html#top">subagentLib</a></b>

<hr>
<a name="snmpMasterQueryHandler"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>snmpMasterQueryHandler</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>snmpMasterQueryHandler</i>(&nbsp;)</strong> - handles replies from the subagent</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>UINT_16_T snmpMasterQueryHandler
    (
    OCTET_T * pMsg, /* pointer to the packet */
    ALENGTH_T msgl, /* length of packet */
    int       flag  /* should be 1 */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine is for use with <b><i><a href="./subagentLib.html#snmpMasterHandlerAsync">snmpMasterHandlerAsync</a></i>(&nbsp;)</b>. It handles the replies
to queries generated by the method routines. It decodes the message and tries
to integrate the response with an outstanding packet. The <i>pMsg</i> and <i>msgl</i>
parameters are pointers to the message and the length respectively. The
<i>flag</i> parameter specifies whether the continuation routines should be run.
This should always be set to 1.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The request ID if routine could decode the packet or 0 in case of 
error.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./subagentLib.html#top">subagentLib</a></b>

<hr>
<a name="snmpMasterCleanup"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>snmpMasterCleanup</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>snmpMasterCleanup</i>(&nbsp;)</strong> - free up resources after a query times out</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>void snmpMasterCleanup
    (
    UINT_16_T reqid,  /* request Id to track state block */
    UINT_16_T options /* as mentioned above */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
If you use <b><i><a href="./subagentLib.html#snmpMasterHandlerAsync">snmpMasterHandlerAsync</a></i>(&nbsp;)</b>, the master agent calls this routine
if the IPC layer determines that a
timeout period for a query response has been exceeded. The <i>reqid</i> parameter
is the same as the <i>requestId</i> value passed to the send routine.  It is used
to track the correct state block.  The <i>options</i> parameter passes in a set
of flags that control what actions the cleanup routine.  Currently, there
are three flags: <b>SA_CLEANUP_INACTIVE</b>, <b>SA_CLEANUP_TIMEOUT</b>, and
<b>SA_CLEANUP_CONTINUE</b>. The continue and timeout flags should always be set.
The inactive flag indicates that any objects associated with the subagent
should be removed. Set this flag when the IPC layer determines that the
subagent has stopped rather than timed out.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
N/A
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./subagentLib.html#top">subagentLib</a></b>

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