X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fdpif-provider.h;h=317e61706729d5959d5ee6732105351f7806ac6b;hb=6ec5f0c5f0e0b8e5827364a3f1b8b46da8b650ad;hp=594ce592031b0a268915be5343d8a38bdee278a6;hpb=e0edde6fee279cdbbf3c179f5f50adaf0c7c7f1e;p=openvswitch

diff --git a/lib/dpif-provider.h b/lib/dpif-provider.h
index 594ce592..317e6170 100644
--- a/lib/dpif-provider.h
+++ b/lib/dpif-provider.h
@@ -110,8 +110,12 @@ struct dpif_class {
     /* Retrieves statistics for 'dpif' into 'stats'. */
     int (*get_stats)(const struct dpif *dpif, struct dpif_dp_stats *stats);
 
-    /* Adds 'netdev' as a new port in 'dpif'.  If successful, sets '*port_no'
-     * to the new port's port number. */
+    /* Adds 'netdev' as a new port in 'dpif'.  If '*port_no' is not
+     * UINT16_MAX, attempts to use that as the port's port number.
+     *
+     * If port is successfully added, sets '*port_no' to the new port's
+     * port number.  Returns EBUSY if caller attempted to choose a port
+     * number, and it was in use. */
     int (*port_add)(struct dpif *dpif, struct netdev *netdev,
                     uint16_t *port_no);
 
@@ -136,6 +140,10 @@ struct dpif_class {
      * actions as the OVS_USERSPACE_ATTR_PID attribute's value, for use in
      * flows whose packets arrived on port 'port_no'.
      *
+     * A 'port_no' of UINT16_MAX should be treated as a special case.  The
+     * implementation should return a reserved PID, not allocated to any port,
+     * that the client may use for special purposes.
+     *
      * The return value only needs to be meaningful when DPIF_UC_ACTION has
      * been enabled in the 'dpif''s listen mask, and it is allowed to change
      * when DPIF_UC_ACTION is disabled and then re-enabled.