[ovs-dev] [PATCH 16/24] ofp-util: Update OFPC_COMMON and add ofputil_capabilities_mask

[Simon Horman]

There are capabilities which are present in one, two and three
of Open Flow 1.0, 1.1 and 1.2. Update OFPC_COMMON to only include
capabilities that are prsent in all three Open Flow versions and
add ofputil_capabilities_mask() to return the mask of capabilities
for each version.

This does not cover OFPUTIL_C_STP and OFPUTIL_C_GROUP_STATS, which
both use capability bit 3 and are treated as special cases in
ofputil_encode_switch_features() and ofputil_decode_switch_features().

Signed-off-by: Simon Horman <horms at verge.net.au>

---

v7
* Manual Rebase
* Use OFPC12_PORT_BLOCKED and OFPC_ARP_MATCH_IP in place of
  OFPUTIL_C_ARP_MATCH_IP and OFPUTIL_C_PORT_BLOCKED in
  ofputil_capabilities_mask(). I'm unsure what I was thinking.

v6
* No change

v5
* No change

v4
* No change

v3
* No change

v2
* No change
---
 lib/ofp-util.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index d0eb72c..695432f 100644
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -2351,7 +2351,7 @@ ofputil_append_port_desc_stats_reply(uint8_t ofp_version,
 /* ofputil_switch_features */
 
 #define OFPC_COMMON (OFPC_FLOW_STATS | OFPC_TABLE_STATS | OFPC_PORT_STATS | \
-                     OFPC_IP_REASM | OFPC_QUEUE_STATS | OFPC_ARP_MATCH_IP)
+                     OFPC_IP_REASM | OFPC_QUEUE_STATS)
 BUILD_ASSERT_DECL((int) OFPUTIL_C_FLOW_STATS == OFPC_FLOW_STATS);
 BUILD_ASSERT_DECL((int) OFPUTIL_C_TABLE_STATS == OFPC_TABLE_STATS);
 BUILD_ASSERT_DECL((int) OFPUTIL_C_PORT_STATS == OFPC_PORT_STATS);
@@ -2424,6 +2424,22 @@ decode_action_bits(ovs_be32 of_actions,
     return ofputil_actions;
 }
 
+static uint32_t
+ofputil_capabilities_mask(uint8_t ofp_version)
+{
+    /* Handle capabilities whose bit is unique for all Open Flow versions */
+    switch (ofp_version) {
+    case OFP10_VERSION:
+    case OFP11_VERSION:
+        return OFPC_COMMON | OFPC_ARP_MATCH_IP;
+    case OFP12_VERSION:
+        return OFPC_COMMON | OFPC12_PORT_BLOCKED;
+    default:
+        /* Caller needs to check osf->header.version itself */
+        return 0;
+    }
+}
+
 /* Decodes an OpenFlow 1.0 or 1.1 "switch_features" structure 'osf' into an
  * abstract representation in '*features'.  Initializes '*b' to iterate over
  * the OpenFlow port structures following 'osf' with later calls to
@@ -2445,7 +2461,8 @@ ofputil_decode_switch_features(const struct ofp_header *oh,
     features->n_buffers = ntohl(osf->n_buffers);
     features->n_tables = osf->n_tables;
 
-    features->capabilities = ntohl(osf->capabilities) & OFPC_COMMON;
+    features->capabilities = ntohl(osf->capabilities) &
+        ofputil_capabilities_mask(oh->version);
 
     if (b->size % ofputil_get_phy_port_size(oh->version)) {
         return OFPERR_OFPBRC_BAD_LEN;
@@ -2537,7 +2554,8 @@ ofputil_encode_switch_features(const struct ofputil_switch_features *features,
     osf->n_buffers = htonl(features->n_buffers);
     osf->n_tables = features->n_tables;
 
-    osf->capabilities = htonl(features->capabilities & OFPC_COMMON);
+    osf->capabilities = htonl(features->capabilities &
+                              ofputil_capabilities_mask(version));
     if (version == OFP10_VERSION) {
         if (features->capabilities & OFPUTIL_C_STP) {
             osf->capabilities |= htonl(OFPC10_STP);
-- 
1.7.10.2.484.gcd07cc5