libxl: postpone backend name resolution

This adds a backend_domname field in libxl devices that contain a
backend_domid field, allowing either a domid or a domain name to be
specified in the configuration structures.  The domain name is resolved
into a domain ID in the _setdefault function when adding the device.
This change allows the backend of the block devices to be specified
(which previously required passing the libxl_ctx down into the block
device parser), and will simplify specification of backend domains in
other users of libxl.

The check on run_hotplug_scripts in parse_config_data is removed because
it is a duplicate of the one in libxl__device_nic_setdefault, and is
removed here because it no longer has the resolved domain ID to check.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- reran flex ]

1 files changed, 19 insertions, 0 deletions

diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
index 8f7879060f..35da71c482 100644
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -90,6 +90,25 @@ int libxl_name_to_domid(libxl_ctx *ctx, const char *name,
     return ret;
 }
 
+int libxl_domain_qualifier_to_domid(libxl_ctx *ctx, const char *name,
+                                    uint32_t *domid)
+{
+    int i, rv;
+    for (i=0; name[i]; i++) {
+        if (!isdigit(name[i])) {
+            goto nondigit_found;
+        }
+    }
+    *domid = strtoul(name, NULL, 10);
+    return 0;
+
+ nondigit_found:
+    /* this could also check for uuids */
+    rv = libxl_name_to_domid(ctx, name, domid);
+    return rv;
+}
+
+
 char *libxl_cpupoolid_to_name(libxl_ctx *ctx, uint32_t poolid)
 {
     unsigned int len;