[ovs-dev] [PATCH] stp: Fix bpdu tx problem in listening state

[kmindg]

The restriction only allows to send bpdu in forwarding state in
compose_output_action__. But a port could send bpdu in listening
and learning state according to comments in lib/stp.h(State of
an STP port).

Signed-off-by: kmindg <kmindg at gmail.com>
---
 lib/stp.c                    |  9 +++++++++
 lib/stp.h                    |  1 +
 ofproto/ofproto-dpif-xlate.c | 24 ++++++++++++++++++++----
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/lib/stp.c b/lib/stp.c
index e4ddf3c..8ecc261 100644
--- a/lib/stp.c
+++ b/lib/stp.c
@@ -685,6 +685,15 @@ stp_learn_in_state(enum stp_state state)
     return (state & (STP_DISABLED | STP_LEARNING | STP_FORWARDING)) != 0;
 }
 
+/* Returns true if 'state' is one in which rx&tx bpdu should be done on
+ * on a port, false otherwise. */
+bool
+stp_listen_in_state(enum stp_state state)
+{
+    return (state &
+            (STP_LISTENING | STP_LEARNING | STP_FORWARDING)) != 0;
+}
+
 /* Returns the name for the given 'role' (for use in debugging and log
  * messages). */
 const char *
diff --git a/lib/stp.h b/lib/stp.h
index affde18..c0175cd 100644
--- a/lib/stp.h
+++ b/lib/stp.h
@@ -120,6 +120,7 @@ enum stp_state {
 const char *stp_state_name(enum stp_state);
 bool stp_forward_in_state(enum stp_state);
 bool stp_learn_in_state(enum stp_state);
+bool stp_listen_in_state(enum stp_state);
 
 /* Role of an STP port. */
 enum stp_role {
diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
index eb4931e..97c4e59 100644
--- a/ofproto/ofproto-dpif-xlate.c
+++ b/ofproto/ofproto-dpif-xlate.c
@@ -665,7 +665,7 @@ xport_get_stp_port(const struct xport *xport)
         : NULL;
 }
 
-static enum stp_state
+static bool
 xport_stp_learn_state(const struct xport *xport)
 {
     struct stp_port *sp = xport_get_stp_port(xport);
@@ -679,6 +679,13 @@ xport_stp_forward_state(const struct xport *xport)
     return stp_forward_in_state(sp ? stp_port_get_state(sp) : STP_DISABLED);
 }
 
+static bool
+xport_stp_listen_state(const struct xport *xport)
+{
+    struct stp_port *sp = xport_get_stp_port(xport);
+    return stp_listen_in_state(sp ? stp_port_get_state(sp) : STP_DISABLED);
+}
+
 /* Returns true if STP should process 'flow'.  Sets fields in 'wc' that
  * were used to make the determination.*/
 static bool
@@ -1693,9 +1700,18 @@ compose_output_action__(struct xlate_ctx *ctx, ofp_port_t ofp_port,
     } else if (xport->config & OFPUTIL_PC_NO_FWD) {
         xlate_report(ctx, "OFPPC_NO_FWD set, skipping output");
         return;
-    } else if (check_stp && !xport_stp_forward_state(xport)) {
-        xlate_report(ctx, "STP not in forwarding state, skipping output");
-        return;
+    } else if (check_stp) {
+        if (eth_addr_equals(ctx->base_flow.dl_dst, eth_addr_stp)) {
+            if (!xport_stp_listen_state(xport)) {
+                xlate_report(ctx, "STP not in listening state, "
+                             "skipping bpdu output");
+                return;
+            }
+        } else if (!xport_stp_forward_state(xport)) {
+            xlate_report(ctx, "STP not in forwarding state, "
+                         "skipping output");
+            return;
+        }
     }
 
     if (mbridge_has_mirrors(ctx->xbridge->mbridge) && xport->xbundle) {
-- 
1.9.0