[ovs-discuss] [openvswitch 2.9.90] Unable to use literal in nested output of learn action

[Flavio Fernandes]

Dear OVS Gurus:

I came across something simple and silly, which is making me think it is actually a bug.

In a nutshell, I'm trying to use a literal with the action output nested in a learn().
If I use a fancier (and more common) notation:

   output:NXM_OF_IN_PORT[]

that works fine. However, if I try to use a literal such as:

   output:2

I get:

   ovs-ofctl: 2: unknown field `2'


Here is a set of steps I use from a sandbox session:

   $ ./boot.sh ; ./configure ; make -j4 ; \
     make sandbox

   $ ovs-vsctl add-br br0 \
         -- add-port br0 p1 -- set interface p1 ofport_request=1 \
         -- add-port br0 p2 -- set interface p2 ofport_request=2 \
         -- set Bridge br0 fail-mode=secure

   # this works just fine
   $ ovs-ofctl add-flow br0 "table=0 actions=learn(table=1, hard_timeout=600, \
         in_port=1, \
         NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[], \
         output:NXM_OF_IN_PORT[]), \
         resubmit(,1)"

   $ ovs-ofctl add-flow br0 "table=1 priority=0 actions=flood"

   $ ovs-ofctl -OOpenFlow13 --names --no-stat dump-flows br0
     reset_counts actions=learn(table=1,hard_timeout=600,in_port=p1,NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],output:NXM_OF_IN_PORT[]),resubmit(,1)
     table=1, reset_counts priority=0 actions=FLOOD

   # very similar to the learn action done above, except I'm attempting to hard code an output value
   $ ovs-ofctl add-flow br0 "table=0 actions=learn(table=1, hard_timeout=600, \
         in_port=2, \
         NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[], \
         output:2), \
         resubmit(,1)"
   ovs-ofctl: 2: unknown field `2'

   $ echo $?
   1

I also played a little bit with the parser test to reproduce this behavior. See below.

So... bug or FAD? If you think BUG, I can dig a little more to learn what is going on.
It has been a while, so chances are that most of you will have this fixed before I manage
to blink. :)

Best,

-- flaviof




$ make check TESTSUITEFLAGS=--list 2>/dev/null | grep -m1 -i learn
454: learn.at:3         learning action - parsing and formatting


$ git diff
diff --git a/tests/learn.at b/tests/learn.at
index 5f1d6df..eaf1147 100644
--- a/tests/learn.at
+++ b/tests/learn.at
@@ -7,6 +7,7 @@ actions=learn(send_flow_rem)
actions=learn(delete_learned)
actions=learn(send_flow_rem,delete_learned)
actions=learn(NXM_OF_VLAN_TCI[0..11], NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[], output:NXM_OF_IN_PORT[], load:10->NXM_NX_REG0[5..10])
+actions=learn(NXM_OF_VLAN_TCI[0..11], NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[], output:99)
actions=learn(table=1,idle_timeout=10, hard_timeout=20, fin_idle_timeout=5, fin_hard_timeout=10, priority=10, cookie=0xfedcba9876543210, in_port=99,eth_dst=eth_src,load:in_port->reg1[16..31])
actions=learn(limit=4096)
actions=learn(limit=4096,result_dst=reg0[0])


$ make check TESTSUITEFLAGS='454'
...
454: learning action - parsing and formatting        FAILED (learn.at:15)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Message signed with OpenPGP
URL: <http://mail.openvswitch.org/pipermail/ovs-discuss/attachments/20180406/8fcdabd9/attachment.sig>