[ovs-dev] [PATCH 4/7] Keep all of tunnel metadata in flow.

[Jarno Rajahalme]

Do not clear tunnel metadata on tunnel input. This is used by a later patch.

Signed-off-by: Jarno Rajahalme <jarno.rajahalme at nsn.com>
---
 lib/match.c            |    4 ----
 ofproto/ofproto-dpif.c |   26 ++++++++++++--------------
 ofproto/tunnel.c       |    3 +--
 3 files changed, 13 insertions(+), 20 deletions(-)

diff --git a/lib/match.c b/lib/match.c
index 2aa4e89..222e5d7 100644
--- a/lib/match.c
+++ b/lib/match.c
@@ -133,13 +133,9 @@ match_wc_init(struct match *match, const struct flow *flow)
 void
 match_init_exact(struct match *match, const struct flow *flow)
 {
-    ovs_be64 tun_id = flow->tunnel.tun_id;
-
     match->flow = *flow;
     match->flow.skb_priority = 0;
     match->flow.skb_mark = 0;
-    memset(&match->flow.tunnel, 0, sizeof match->flow.tunnel);
-    match->flow.tunnel.tun_id = tun_id;
     flow_wildcards_init_exact(&match->wc);
 }
 
diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index 33b09c6..b88a2d4 100644
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -6836,8 +6836,6 @@ action_xlate_ctx_init(struct action_xlate_ctx *ctx,
                       struct rule_dpif *rule,
                       uint8_t tcp_flags, const struct ofpbuf *packet)
 {
-    ovs_be64 initial_tun_id = flow->tunnel.tun_id;
-
     /* Flow initialization rules:
      * - 'base_flow' must match the kernel's view of the packet at the
      *   time that action processing starts.  'flow' represents any
@@ -6849,23 +6847,23 @@ action_xlate_ctx_init(struct action_xlate_ctx *ctx,
      *   to another device without any modifications this will cause us to
      *   insert a new tag since the original one was stripped off by the
      *   VLAN device.
-     * - Tunnel 'flow' is largely cleared when transitioning between
-     *   the input and output stages since it does not make sense to output
-     *   a packet with the exact headers that it was received with (i.e.
-     *   the destination IP is us).  The one exception is the tun_id, which
-     *   is preserved to allow use in later resubmit lookups and loads into
-     *   registers.
-     * - Tunnel 'base_flow' is completely cleared since that is what the
-     *   kernel does.  If we wish to maintain the original values an action
-     *   needs to be generated. */
-
+     * - Tunnel metadata as received is retained in both 'flow' and
+     *   'base_flow'.  This will prevent packet output with the exact same
+     *   headers as it was received with (which would not make sense since
+     *   the destination would be us).  In effect, this emulates the kernel
+     *   behavior of clearing the tunnel metadata before action processing.
+     *   Keeping the tunnel fields in 'flow' allows tunnel metadata matching
+     *   also in later tables.
+     *   Since a kernel action for setting the tunnel metadata will only be
+     *   generated with actual tunnel output, changing the tunnel metadata
+     *   values in 'flow' (such as tun_id) will only have effect with a later
+     *   tunnel output action.
+     */
     ctx->ofproto = ofproto;
     ctx->flow = *flow;
-    memset(&ctx->flow.tunnel, 0, sizeof ctx->flow.tunnel);
     ctx->base_flow = ctx->flow;
     ctx->base_flow.vlan_tci = initial_vals->vlan_tci;
     ctx->base_flow.tunnel.ip_tos = initial_vals->tunnel_ip_tos;
-    ctx->flow.tunnel.tun_id = initial_tun_id;
     ctx->rule = rule;
     ctx->packet = packet;
     ctx->may_learn = packet != NULL;
diff --git a/ofproto/tunnel.c b/ofproto/tunnel.c
index 8aa7fbe..8f5435a 100644
--- a/ofproto/tunnel.c
+++ b/ofproto/tunnel.c
@@ -198,8 +198,7 @@ tnl_port_receive(struct flow *flow)
     }
 
     flow->in_port = tnl_port->ofport->ofp_port;
-    memset(&flow->tunnel, 0, sizeof flow->tunnel);
-    flow->tunnel.tun_id = match.in_key;
+    /* Keep flow->tunnel to allow matching on tunnel metadata */
 
     if (pre_flow_str) {
         char *post_flow_str = flow_to_string(flow);
-- 
1.7.10.4