[ovs-dev] [PATCH V2 2/2] ofproto-dpif-xlate: Add include mode to priority tags

[Eli Britstein]

Configure "include-non-zero" priority tags to retain the 802.1Q header
when the VLAN ID is zero, except both the VLAN ID and priority are zero.
Add a "include" configuration option to retain the 802.1Q header in such
frames as well.

Signed-off-by: Eli Britstein <elibr at mellanox.com>
Reviewed-by: Roi Dayan <roid at mellanox.com>
---
 NEWS                         |  4 ++++
 ofproto/ofproto-dpif-xlate.c | 11 +++++++----
 ofproto/ofproto.h            |  1 +
 vswitchd/bridge.c            |  2 ++
 vswitchd/vswitch.xml         |  7 ++++---
 5 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/NEWS b/NEWS
index 293531db0..7c5929fa6 100644
--- a/NEWS
+++ b/NEWS
@@ -19,6 +19,10 @@ Post-v2.11.0
      * New "ovs-appctl dpctl/ipf-get-status" command for userspace datapath
        conntrack fragmentation support.
      * New action "check_pkt_len".
+     * Changed options for "other-config:priority-tags" port configuration:
+       "false"/"true" changed to "omit"/"include-non-zero", and added a new
+       option "include" to always retain the 802.1Q header, for frames with
+       both the VLAN ID and priority are zero as well.
    - OVSDB:
      * OVSDB clients can now resynchronize with clustered servers much more
        quickly after a brief disconnection, saving bandwidth and CPU time.
diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
index 4c1cdfa58..28897bf67 100644
--- a/ofproto/ofproto-dpif-xlate.c
+++ b/ofproto/ofproto-dpif-xlate.c
@@ -549,7 +549,8 @@ static void xvlan_copy(struct xvlan *dst, const struct xvlan *src);
 static void xvlan_pop(struct xvlan *src);
 static void xvlan_push_uninit(struct xvlan *src);
 static void xvlan_extract(const struct flow *, struct xvlan *);
-static void xvlan_put(struct flow *, const struct xvlan *);
+static void xvlan_put(struct flow *, const struct xvlan *,
+                      enum port_priority_tags_mode);
 static void xvlan_input_translate(const struct xbundle *,
                                   const struct xvlan *in,
                                   struct xvlan *xvlan);
@@ -2270,13 +2271,15 @@ xvlan_extract(const struct flow *flow, struct xvlan *xvlan)
 
 /* Put VLAN information (headers) to flow */
 static void
-xvlan_put(struct flow *flow, const struct xvlan *xvlan)
+xvlan_put(struct flow *flow, const struct xvlan *xvlan,
+          enum port_priority_tags_mode use_priority_tags)
 {
     ovs_be16 tci;
     int i;
     for (i = 0; i < FLOW_MAX_VLAN_HEADERS; i++) {
         tci = htons(xvlan->v[i].vid | (xvlan->v[i].pcp & VLAN_PCP_MASK));
-        if (tci) {
+        if (tci || ((use_priority_tags == PORT_PRIORITY_TAGS_INCLUDE) &&
+            xvlan->v[i].tpid)) {
             tci |= htons(VLAN_CFI);
             flow->vlans[i].tpid = xvlan->v[i].tpid ?
                                   htons(xvlan->v[i].tpid) :
@@ -2450,7 +2453,7 @@ output_normal(struct xlate_ctx *ctx, const struct xbundle *out_xbundle,
     }
 
     memcpy(&old_vlans, &ctx->xin->flow.vlans, sizeof(old_vlans));
-    xvlan_put(&ctx->xin->flow, &out_xvlan);
+    xvlan_put(&ctx->xin->flow, &out_xvlan, out_xbundle->use_priority_tags);
 
     compose_output_action(ctx, xport->ofp_port, use_recirc ? &xr : NULL,
                           false, false);
diff --git a/ofproto/ofproto.h b/ofproto/ofproto.h
index caf5e50b5..2f83ee077 100644
--- a/ofproto/ofproto.h
+++ b/ofproto/ofproto.h
@@ -420,6 +420,7 @@ enum port_vlan_mode {
 enum port_priority_tags_mode {
     PORT_PRIORITY_TAGS_OMIT = 0,
     PORT_PRIORITY_TAGS_INCLUDE_NON_ZERO,
+    PORT_PRIORITY_TAGS_INCLUDE,
 };
 
 /* The behaviour of the port regarding priority tags */
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index 06c8bf4ca..930b66896 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -1026,6 +1026,8 @@ port_configure(struct port *port)
     const char *pt = smap_get_def(&cfg->other_config, "priority-tags", "");
     if (!strcmp(pt, "include-non-zero") || !strcmp(pt, "true")) {
         s.use_priority_tags = PORT_PRIORITY_TAGS_INCLUDE_NON_ZERO;
+    } else if (!strcmp(pt, "include")) {
+        s.use_priority_tags = PORT_PRIORITY_TAGS_INCLUDE;
     } else {
         s.use_priority_tags = PORT_PRIORITY_TAGS_OMIT;
     }
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index d5f2b0186..37785a385 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -1860,7 +1860,7 @@
       </column>
 
       <column name="other_config" key="priority-tags"
-              type='{"type": "string", "enum": ["set", ["omit", "include-non-zero"]]}'>
+              type='{"type": "string", "enum": ["set", ["omit", "include-non-zero", "include"]]}'>
         <p>
           An 802.1Q header contains two important pieces of information: a VLAN
           ID and a priority.  A frame with a zero VLAN ID, called a
@@ -1877,8 +1877,9 @@
         </p>
 
         <p>
-          Regardless of this setting, Open vSwitch omits the 802.1Q header on
-          output if both the VLAN ID and priority would be zero.
+          For <code>include-non-zero</code> Open vSwitch omits the 802.1Q header on output
+          if both the VLAN ID and priority would be zero. Set to <code>include</code>
+          to retain the 802.1Q header in such frames as well.
         </p>
 
         <p>
-- 
2.17.2