[ovs-dev] [PATCH 2/2] match: Format entire ODP port number in match_format().

[Ben Pfaff]

struct flow has a union for the in_port field, and the two different
members of the union have different sizes: ofp_port_t is 16 bits,
odp_port_t is 32 bits.  On little-endian machines this doesn't matter much,
but on big-endian machines it's important to distinguish between them
because a small number in odp_port_t will show up as zero when viewed
through ofp_port_t.

There are in fact few parts of OVS that can handle a struct flow that
has either formats; most parts of OVS work with one or the other but not
both.  match_format(), however, does need to handle both cases, and it did
not: it displayed small odp_port_t values as zero on big-endian platforms.
This commit fixes the problem by checking the mask, which indicates which
format is in use, and displaying the appropriate field from the union.

Reported-by: Dimitri John Ledkov <xnox at ubuntu.com>
Reported-at: http://openvswitch.org/pipermail/discuss/2016-January/020072.html
Signed-off-by: Ben Pfaff <blp at ovn.org>
---
 lib/match.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/match.c b/lib/match.c
index 95d34bc..5d4a9dc 100644
--- a/lib/match.c
+++ b/lib/match.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015 Nicira, Inc.
+ * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -1162,7 +1162,9 @@ match_format(const struct match *match, struct ds *s, int priority)
 
     format_be64_masked(s, "metadata", f->metadata, wc->masks.metadata);
 
-    if (wc->masks.in_port.ofp_port) {
+    if (wc->masks.in_port.odp_port == UINT32_MAX) {
+        ds_put_format(s, "in_port=%"PRIu32",", f->in_port.odp_port);
+    } else if (wc->masks.in_port.ofp_port) {
         ds_put_cstr(s, "in_port=");
         ofputil_format_port(f->in_port.ofp_port, s);
         ds_put_char(s, ',');
-- 
2.1.3