openflow: Better abstract handling of packet-in messages.

Packet-in messages have been a bit of a mess.  First, their abstraction
in the form of struct ofputil_packet_in has some fields that are used
in a clear way for incoming and outgoing packet-ins, and others
(packet_len, total_len, buffer_id) have have confusing meanings or
usage pattern depending on their direction.

Second, it's very confusing how a packet-in has both a reason (OFPR_*)
and a miss type (OFPROTO_PACKET_IN_*) and how those add up to the
actual reason that is used "on the wire" for each OpenFlow version (and
even whether the packet-in is sent at all!).

Finally, there's all kind of low-level detail randomly scattered between
connmgr, ofproto-dpif-xlate, and ofp-util.

This commit attempts to clear up some of the confusion.  It simplifies
the struct ofputil_packet_in abstraction by removing the members that
didn't have a clear and consistent meaning between incoming and outgoing
packet-ins.  It gets rid of OFPROTO_PACKET_IN_*, instead adding a couple
of nonstandard OFPR_* reasons that add up to what OFPROTO_PACKET_IN_*
was meant to say (in what I hope is a clearer way).  And it consolidates
the tricky parts into ofp-util, where I hope it will be easier to
understand all in one place.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Jarno Rajahalme <jarno@ovn.org>

1 files changed, 1 insertions, 21 deletions

diff --git a/ofproto/connmgr.h b/ofproto/connmgr.h
index 98821bc7b..ced6a6890 100644
--- a/ofproto/connmgr.h
+++ b/ofproto/connmgr.h
@@ -54,32 +54,12 @@ enum ofconn_type {
     OFCONN_SERVICE              /* A service connection, e.g. "ovs-ofctl". */
 };
 
-enum ofproto_packet_in_miss_type {
-    /* Not generated by a flow miss or table-miss flow. */
-    OFPROTO_PACKET_IN_NO_MISS,
-
-    /* The packet_in was generated directly by a table-miss flow, that is, a
-     * flow with priority 0 that wildcards all fields.  See OF1.3.3 section
-     * 5.4.
-     *
-     * (Our interpretation of "directly" is "not via groups".  Packet_ins
-     * generated by table-miss flows via groups use
-     * OFPROTO_PACKET_IN_NO_MISS.) */
-    OFPROTO_PACKET_IN_MISS_FLOW,
-
-    /* The packet-in was generated directly by a table-miss, but not a
-     * table-miss flow.  That is, it was generated by the OpenFlow 1.0, 1.1, or
-     * 1.2 table-miss behavior. */
-    OFPROTO_PACKET_IN_MISS_WITHOUT_FLOW,
-};
-
 /* A packet_in, with extra members to assist in queuing and routing it. */
 struct ofproto_packet_in {
     struct ofputil_packet_in up;
     struct ovs_list list_node;  /* For queuing. */
     uint16_t controller_id;     /* Controller ID to send to. */
-    int send_len;               /* Length that the action requested sending. */
-    enum ofproto_packet_in_miss_type miss_type;
+    int max_len;                /* From action, or -1 if none. */
 };
 
 /* Basics. */