<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;color:rgb(0,0,0)"><pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;font-size:14px;vertical-align:baseline;background-color:rgb(238,238,238);font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;line-height:18px">
<code style="margin:0px;padding:0px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif"><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">I am wirting a POX controller which uses a database backend.</span></code></pre>
<pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;font-size:14px;vertical-align:baseline;background-color:rgb(238,238,238);font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;line-height:18px">
<code style="margin:0px;padding:0px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif"><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)"><p style="margin:0px 0px 1em;padding:0px;border:0px;vertical-align:baseline;background-color:rgb(255,255,255);clear:both;word-wrap:break-word;color:rgb(0,0,0);font-family:Arial,'Liberation Sans','DejaVu Sans',sans-serif;white-space:normal">
I have this peice of code.I replaced</p><pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;color:rgb(0,0,0)">
<code style="margin:0px;padding:0px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif"><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#if session.query(SourcetoPort).filter_by(src_address=str(packet.dst)).count():</span></code></pre>
<p style="margin:0px 0px 1em;padding:0px;border:0px;vertical-align:baseline;background-color:rgb(255,255,255);clear:both;word-wrap:break-word;color:rgb(0,0,0);font-family:Arial,'Liberation Sans','DejaVu Sans',sans-serif;white-space:normal">
with</p><pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;color:rgb(0,0,0)">
<code style="margin:0px;padding:0px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif"><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">if</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> session</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">query</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">exists</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">().</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">where</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">SourcetoPort</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">src_address </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">==</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> str</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">dst</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">))).</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">scalar</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">()</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">is</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">not</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">None</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">:</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">Now</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> I am getting the following error</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">File</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">"/home/karthik/pox/tutorial.py"</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> line </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">86</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> act_like_switch
self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">send_packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">buffer_id</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">data</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">q_res</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">port_no</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">in_port</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">AttributeError</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">:</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">'NoneType'</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> object has no attribute </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">'port_no'</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">^</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">CINFO</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">:</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">core</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">:</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">Going</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> down</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">...</span></code></pre>
<pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;color:rgb(0,0,0)">
<br></pre><pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;color:rgb(0,0,0)">
The code is given below.<span style="background-color:rgb(255,255,255);font-family:Arial,'Liberation Sans','DejaVu Sans',sans-serif;white-space:normal">The above piece of code used to work with count query.Why is it now working with exists query. I am very new to python and sqlalchemy.Can someone advise why this is happening.? </span></pre>
</span></code></pre><pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;font-size:14px;vertical-align:baseline;background-color:rgb(238,238,238);font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;line-height:18px">
<code style="margin:0px;padding:0px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif"><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">class</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">SourcetoPort</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">Base</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">):</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">""""""</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
__tablename__ </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">'source_to_port'</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
id </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">Column</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">Integer</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> primary_key</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">True</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
port_no </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">Column</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">Integer</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
src_address </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">Column</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">String</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">index</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">True</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#----------------------------------------------------------------------</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">def</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> __init__</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> src_address</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">port_no</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">):</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">""""""</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">src_address </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> src_address
self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">port_no </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> port_no
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">def</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> act_like_switch </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">):</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">"""
Implement switch-like behavior.
"""</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray"># Learn the port for the source MAC</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#print "RECIEVED FROM PORT ",packet_in.in_port , "SOURCE ",packet.src</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray"># create a Session</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#Session = sessionmaker(bind=engine)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#session = Session()</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">mac_to_port</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">[</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">src</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">]=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">in_port
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#if self.mac_to_port.get(packet.dst)!=None:</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">print</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">"count for dst"</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">session</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">query</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">SourcetoPort</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">).</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">filter_by</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">src_address</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">str</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">dst</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)).</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">count</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(),</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">str</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">dst</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#if session.query(SourcetoPort).filter_by(src_address=str(packet.dst)).count():</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">if</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> session</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">query</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">exists</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">().</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">where</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">SourcetoPort</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">src_address </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">==</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> str</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">dst</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">))).</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">scalar</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">()</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">is</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">not</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">None</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">:</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#send this packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">print</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">"got info from the database"</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
q_res </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> session</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">query</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">SourcetoPort</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">).</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">filter_by</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">src_address</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">str</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">dst</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)).</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">first</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">()</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">send_packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">buffer_id</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">data</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">q_res</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">port_no</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">in_port</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#create a flow modification message</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
msg </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> of</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">ofp_flow_mod</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">()</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#set the fields to match from the incoming packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
msg</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">match </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> of</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">ofp_match</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">from_packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#send the rule to the switch so that it does not query the controller again.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
msg</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">actions</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">append</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">of</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">ofp_action_output</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">port</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">q_res</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">port_no</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">))</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#push the rule</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">connection</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">send</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">msg</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">else</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">:</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#flood this packet out as we don't know about this node.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(0,0,139)">print</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(128,0,0)">"flooding the first packet"</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
self</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">send_packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">buffer_id</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">data</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
of</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">OFPP_FLOOD</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">in_port</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#self.matrix[(packet.src,packet.dst)]+=1 </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
entry </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:rgb(43,145,175)">SourcetoPort</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">src_address</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">str</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">src</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> </span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">,</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent"> port_no</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">=</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">packet_in</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">in_port</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#add the record to the session object</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
session</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">add</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">(</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">entry</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">)</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent;color:gray">#add the record to the session object</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">
session</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">.</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">commit</span><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">()</span></code></pre>
<pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;font-size:14px;vertical-align:baseline;background-color:rgb(238,238,238);font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;line-height:18px">
<code style="margin:0px;padding:0px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif"><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">Regards,</span></code></pre>
<pre class="" style="margin-top:0px;margin-bottom:10px;padding:5px;border:0px;font-size:14px;vertical-align:baseline;background-color:rgb(238,238,238);font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif;overflow:auto;width:auto;max-height:600px;line-height:18px">
<code style="margin:0px;padding:0px;border:0px;vertical-align:baseline;font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif"><span class="" style="margin:0px;padding:0px;border:0px;vertical-align:baseline;background-color:transparent">Karthik Sharma</span></code></pre>
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