The original packet-out format allowed multiple actions to be specified for
buffered packets, but only a destination port for messages including data.
This change makes packet-out more consistent by allowing multiple actions
regardless of how the packet is stored.
This change also disallows sending packets through the incoming port without
explicitly using the OFPP_IN_PORT virtual port.
Now it helps clients track the number of in-flight messages, but lets the
clients do the limiting themselves. This will come in handy for packet-in
rate limiting (in an upcoming commit), in which we want to track in-flight
packet-in messages separately from other in-flight messages.
This updates the OpenFlow protocol version and changes the names of
structure members, so any software that uses OpenFlow will need to be
updated to match.
libtool was needed when NOX was directly linking against libopenflow.
Since it doesn't do that anymore, we can drop its use (and that makes
OpenFlow configure and build slightly faster).
This keeps vlogconf, in particular, from being linked against OpenSSL,
which in turn keeps the Debian package build tools from complaining that
the openflow-common package shouldn't need to depend on OpenSSL but does
because of the spurious library link.
One use case is when NOX is running on localhost, in which case waiting
for the full default backoff interval is unnecessary and undesirable.
Also changes default maximum backoff to 15 seconds (from 60).
It can happen that the secure channel thinks that it is connected
to the controller, but in fact the connection has dropped. For
example, a switch intermediate between the secure channel and the
controller could have a flow inserted, due to a malfunction, that
causes packets in one direction or the other to be dropped. When
this happens, the Linux kernel's TCP implementation will continue
retransmitting packets for somewhere between 13 and 30 minutes,
depending on the connection's retransmission timeout (according
to linux/Documentation/networking/ip-sysctl.txt) with the default
Linux settings.
We want to detect the lost connection and re-connect much faster
than that. We use OpenFlow echo request and reply messages: if
no message is received from the controller for N seconds, we
send out an echo request. If no reply (actually, any message at
all) is received for an additional N seconds, then we assume
that the connection has been lost, and reconnect.
This brings the user-space switch in-line with fixes that were previously
made to the kernel one. The main problem was that when wildcards are used
some of the fields that follow should also be wildcarded.
Ben Pfaff
Justin Pettit