[RFC PATCH 1/5] tools/libs/light: Add vid field to libxl_device_nic

[Leigh Brown <leigh@xxxxxxxxxxxxx>]

Add integer member `vid' to libxl_device_nic, to represent the
VLAN ID to assign to the VIF when adding it to the bridge device.

Update libxl_nic.c to read and write the vid field from the
xenstore.

This provides the capability for supported operating systems (e.g.
Linux) to perform VLAN filtering on bridge ports.  The Xen
hotplug scripts need to be updated to read this information from
then xenstore and perform the required configuration.

Signed-off-by: Leigh Brown <leigh@xxxxxxxxxxxxx>
---
 tools/libs/light/libxl_nic.c     | 20 ++++++++++++++++++++
 tools/libs/light/libxl_types.idl |  1 +
 2 files changed, 21 insertions(+)

diff --git a/tools/libs/light/libxl_nic.c b/tools/libs/light/libxl_nic.c
index d6bf06fc34..e28b9101ee 100644
--- a/tools/libs/light/libxl_nic.c
+++ b/tools/libs/light/libxl_nic.c
@@ -233,6 +233,11 @@ static int libxl__set_xenstore_nic(libxl__gc *gc, uint32_t 
domid,
         flexarray_append(back, GCSPRINTF("%u", nic->mtu));
     }
     
+    if (nic->vid) {
+        flexarray_append(back, "vid");
+        flexarray_append(back, GCSPRINTF("%u", nic->vid));
+    }
+
     flexarray_append(back, "bridge");
     flexarray_append(back, libxl__strdup(gc, nic->bridge));
     flexarray_append(back, "handle");
@@ -313,6 +318,21 @@ static int libxl__nic_from_xenstore(libxl__gc *gc, const 
char *libxl_path,
         nic->mtu = LIBXL_DEVICE_NIC_MTU_DEFAULT;
     }
 
+    rc = libxl__xs_read_checked(gc, XBT_NULL,
+                                GCSPRINTF("%s/vid", libxl_path), &tmp);
+    if (rc) goto out;
+    if (tmp) {
+        char *endptr;
+
+        nic->vid = strtol(tmp, &endptr, 10);
+        if (*endptr != '\0') {
+            rc = ERROR_INVAL;
+            goto out;
+        }
+    } else {
+        nic->vid = 0;
+    }
+
     rc = libxl__xs_read_checked(gc, XBT_NULL,
                                 GCSPRINTF("%s/mac", libxl_path), &tmp);
     if (rc) goto out;
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 7d8bd5d216..df5185128c 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -809,6 +809,7 @@ libxl_device_nic = Struct("device_nic", [
     ("backend_domname", string),
     ("devid", libxl_devid),
     ("mtu", integer),
+    ("vid", integer),
     ("model", string),
     ("mac", libxl_mac),
     ("ip", string),
-- 
2.39.2