ofproto: Treat a packet-out in_port of OFPP_CONTROLLER as OFPP_NONE.

Some OpenFlow 1.0 controllers incorrectly use OPFP_CONTROLLER as the
in_port in packet-out messages, when OFPP_NONE is their intent.  Until now,
Open vSwitch has rejected such requests with an error message.  This commit
makes Open vSwitch instead treat OFPP_CONTROLLER the same as OFPP_NONE for
compatibility with those controllers.

(Also, as of this writing, OpenFlow 1.0.1 appears to be changing the port
to use from OFPP_NONE to OFPP_CONTROLLER.)

Suggested-by: Rob Sherwood <rob.sherwood@bigswitch.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

4 files changed, 25 insertions, 5 deletions

diff --git a/lib/odp-util.c b/lib/odp-util.c
index 110b60be..f2cf12c4 100644
--- a/lib/odp-util.c
+++ b/lib/odp-util.c
@@ -1157,7 +1157,7 @@ odp_flow_key_from_flow(struct ofpbuf *buf, const struct flow *flow)
         nl_msg_put_be64(buf, OVS_KEY_ATTR_TUN_ID, flow->tun_id);
     }
 
-    if (flow->in_port != OFPP_NONE) {
+    if (flow->in_port != OFPP_NONE && flow->in_port != OFPP_CONTROLLER) {
         nl_msg_put_u32(buf, OVS_KEY_ATTR_IN_PORT,
                        ofp_port_to_odp_port(flow->in_port));
     }
diff --git a/lib/ofp-util.h b/lib/ofp-util.h
index 13195c76..971331a5 100644
--- a/lib/ofp-util.h
+++ b/lib/ofp-util.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
diff --git a/ofproto/ofproto-provider.h b/ofproto/ofproto-provider.h
index 6dd206b9..263b5758 100644
--- a/ofproto/ofproto-provider.h
+++ b/ofproto/ofproto-provider.h
@@ -871,8 +871,27 @@ struct ofproto_class {
      *
      * 'flow' reflects the flow information for 'packet'.  All of the
      * information in 'flow' is extracted from 'packet', except for
-     * flow->in_port, which is taken from the OFPT_PACKET_OUT message.
-     * flow->tun_id and its register values are zeroed.
+     * flow->in_port (see below).  flow->tun_id and its register values are
+     * zeroed.
+     *
+     * flow->in_port comes from the OpenFlow OFPT_PACKET_OUT message.  The
+     * implementation should reject invalid flow->in_port values by returning
+     * OFPERR_NXBRC_BAD_IN_PORT.  For consistency, the implementation should
+     * consider valid for flow->in_port any value that could possibly be seen
+     * in a packet that it passes to connmgr_send_packet_in().  Ideally, even
+     * an implementation that never generates packet-ins (e.g. due to hardware
+     * limitations) should still allow flow->in_port values for every possible
+     * physical port and OFPP_LOCAL.  The only virtual ports (those above
+     * OFPP_MAX) that the caller will ever pass in as flow->in_port, other than
+     * OFPP_LOCAL, are OFPP_NONE and OFPP_CONTROLLER.  The implementation
+     * should allow both of these, treating each of them as packets generated
+     * by the controller as opposed to packets originating from some switch
+     * port.
+     *
+     * (Ordinarily the only effect of flow->in_port is on output actions that
+     * involve the input port, such as actions that output to OFPP_IN_PORT,
+     * OFPP_FLOOD, or OFPP_ALL.  flow->in_port can also affect Nicira extension
+     * "resubmit" actions.)
      *
      * 'packet' is not matched against the OpenFlow flow table, so its
      * statistics should not be included in OpenFlow flow statistics.
diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 766646db..bdf82a18 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -1873,7 +1873,8 @@ handle_packet_out(struct ofconn *ofconn, const struct ofp_header *oh)
      * we do know that only certain reserved ports (numbered OFPP_MAX and
      * above) are valid. */
     in_port = ntohs(opo->in_port);
-    if (in_port >= OFPP_MAX && in_port != OFPP_LOCAL && in_port != OFPP_NONE) {
+    if (in_port >= OFPP_MAX && in_port != OFPP_LOCAL && in_port != OFPP_NONE
+        && in_port != OFPP_CONTROLLER) {
         return ofp_mkerr_nicira(OFPET_BAD_REQUEST, NXBRC_BAD_IN_PORT);
     }