[libvirt] [PATCH] virsh: Make <mac> required when device-detaching interface

[Michal Privoznik]

Problem is, if user does not specify mac address in input XML,
we generate a random one, which is why device-detach fails giving
a confusing error message. Therefore <mac> needs to be required.
---
 tools/virsh.c |   57 ++++++++++++++++++++++++++++++++++++++++++++++-----------
 1 files changed, 46 insertions(+), 11 deletions(-)

diff --git a/tools/virsh.c b/tools/virsh.c
index 2837e0f..dfb48d2 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -8580,9 +8580,12 @@ cmdDetachDevice(vshControl *ctl, const vshCmd *cmd)
     virDomainPtr dom;
     char *from;
     char *buffer;
-    int ret = TRUE;
+    int ret = FALSE;
     int found;
     unsigned int flags;
+    xmlDocPtr xml = NULL;
+    xmlXPathContextPtr ctxt = NULL;
+    int mac_cnt;
 
     if (!vshConnectionUsability(ctl, ctl->conn))
         return FALSE;
@@ -8592,14 +8595,41 @@ cmdDetachDevice(vshControl *ctl, const vshCmd *cmd)
 
     from = vshCommandOptString(cmd, "file", &found);
     if (!found) {
-        virDomainFree(dom);
-        return FALSE;
+        goto cleanup;
     }
 
     if (virFileReadAll(from, VIRSH_MAX_XML_FILE, &buffer) < 0) {
         virshReportError(ctl);
-        virDomainFree(dom);
-        return FALSE;
+        goto cleanup;
+    }
+
+    xml = xmlReadDoc((const xmlChar *) buffer, "interface.xml", NULL,
+                     XML_PARSE_NOENT | XML_PARSE_NONET |
+                     XML_PARSE_NOWARNING);
+
+    if (!xml) {
+        vshError(ctl, "%s", _("input XML is not valid"));
+        goto cleanup;
+    }
+
+    ctxt = xmlXPathNewContext(xml);
+    mac_cnt = virXPathNodeSet("/interface/mac", ctxt, NULL);
+
+    switch(mac_cnt) {
+        case 1:
+            break;
+
+        case 0:
+        case -1:
+            vshError(ctl, "%s", _("You must specify mac address in xml file"));
+            goto cleanup;
+            break;
+
+        default:
+            vshError(ctl, "%s", _("You must specify exactly one mac address in"
+                                  " xml file"));
+            goto cleanup;
+            break;
     }
 
     if (vshCommandOptBool(cmd, "persistent")) {
@@ -8610,18 +8640,23 @@ cmdDetachDevice(vshControl *ctl, const vshCmd *cmd)
     } else {
         ret = virDomainDetachDevice(dom, buffer);
     }
-    VIR_FREE(buffer);
 
     if (ret < 0) {
+        ret = FALSE;
         vshError(ctl, _("Failed to detach device from %s"), from);
-        virDomainFree(dom);
-        return FALSE;
-    } else {
-        vshPrint(ctl, "%s", _("Device detached successfully\n"));
+        goto cleanup;
     }
 
+    vshPrint(ctl, "%s", _("Device detached successfully\n"));
+    ret = TRUE;
+
+cleanup:
+    xmlXPathFreeContext(ctxt);
+    if (xml)
+        xmlFreeDoc(xml);
+    VIR_FREE(buffer);
     virDomainFree(dom);
-    return TRUE;
+    return ret;
 }
 
 
-- 
1.7.4