switchd(8): don't set output port to OFP*_PORT_ANY for input == output

[Ayaka Koshibe]

Hi,

This is a new version of a previous diff that I had for making switchd(8)
ignore PACKET_IN messages generated from looped traffic. Currently, it will
respond to the PACKET_IN with an invalid PACKET_OUT onto OFP*_PORT_ANY,
resulting in the switch responding with an error that makes switchd disconnect
the switch.

I didn't follow through with the previous diff since it seemed to chew up CPU,
but saw the cause elsewhere after looking at it further. This just improves on
switchd's behavior.

OK?


Thanks,
Ayaka


Index: usr.sbin/switchd/ofp10.c
===================================================================
RCS file: /cvs/src/usr.sbin/switchd/ofp10.c,v
retrieving revision 1.19
diff -u -p -u -r1.19 ofp10.c
--- usr.sbin/switchd/ofp10.c    2 Dec 2016 14:39:46 -0000       1.19
+++ usr.sbin/switchd/ofp10.c    9 Sep 2018 09:36:33 -0000
@@ -393,7 +393,8 @@ ofp10_packet_in(struct switchd *sc, stru
                 * silently drop looping packet
                 * (don't use OFP10_PORT_INPUT here)
                 */
-               dstport = OFP10_PORT_ANY;
+               ret = 0;
+               goto done;
        } else {
                addflow = 1;
        }
Index: usr.sbin/switchd/ofp13.c
===================================================================
RCS file: /cvs/src/usr.sbin/switchd/ofp13.c,v
retrieving revision 1.43
diff -u -p -u -r1.43 ofp13.c
--- usr.sbin/switchd/ofp13.c    17 Jan 2017 09:21:50 -0000      1.43
+++ usr.sbin/switchd/ofp13.c    9 Sep 2018 09:36:33 -0000
@@ -1082,7 +1082,8 @@ ofp13_packet_in(struct switchd *sc, stru
                 * silently drop looping packet
                 * (don't use OFP_PORT_INPUT here)
                 */
-               dstport = OFP_PORT_ANY;
+               ret = 0;
+               goto done;
        } else {
                addflow = 1;
        }