[libvirt] [PATCH v2 4/5] conf: report errors when parsing video resolution

[Jonathon Jongsma]

The current code doesn't properly handle errors when parsing a video
device's resolution.

This patch changes the parse function signature to return an error
when we're missing an 'x' or 'y' parameter or when the 'x' or 'y'
parameters are not positive integers. No error is returned when no
'resolution' element is found.

Previously we were returning a NULL structure for the case where 'x' or
'y' were missing, but were returning an under-specified structure for
the other error cases.

Signed-off-by: Jonathon Jongsma <jjongsma at redhat.com>
---
 src/conf/domain_conf.c | 44 ++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 269a6ec2c3..b3f32d0b63 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -15338,45 +15338,57 @@ virDomainVideoAccelDefParseXML(xmlNodePtr node)
     return g_steal_pointer(&def);
 }
 
-static virDomainVideoResolutionDefPtr
-virDomainVideoResolutionDefParseXML(xmlNodePtr node)
+static int
+virDomainVideoResolutionDefParseXML(xmlNodePtr node,
+                                    virDomainVideoResolutionDefPtr *res)
 {
     xmlNodePtr cur;
     g_autofree virDomainVideoResolutionDefPtr def = NULL;
     g_autofree char *x = NULL;
     g_autofree char *y = NULL;
 
+    *res = NULL;
     cur = node->children;
     while (cur != NULL) {
-        if (cur->type == XML_ELEMENT_NODE) {
-            if (!x && !y &&
-                virXMLNodeNameEqual(cur, "resolution")) {
-                x = virXMLPropString(cur, "x");
-                y = virXMLPropString(cur, "y");
-            }
+        if ((cur->type == XML_ELEMENT_NODE) &&
+            virXMLNodeNameEqual(cur, "resolution")) {
+            x = virXMLPropString(cur, "x");
+            y = virXMLPropString(cur, "y");
+            break;
         }
         cur = cur->next;
     }
 
+    /* resolution not specified */
+    if (cur == NULL)
+        return 0;
+
+    /* resolution specified, but x or y is missing. report error */
     if (!x || !y)
-        return NULL;
+        return -1;
 
     def = g_new0(virDomainVideoResolutionDef, 1);
 
     if (virStrToLong_uip(x, NULL, 10, &def->x) < 0) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("cannot parse video x-resolution '%s'"), x);
-        goto cleanup;
+        return -1;
     }
 
     if (virStrToLong_uip(y, NULL, 10, &def->y) < 0) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("cannot parse video y-resolution '%s'"), y);
-        goto cleanup;
+        return -1;
     }
 
- cleanup:
-    return g_steal_pointer(&def);
+    if (def->x == 0 || def->y == 0) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("resolution values must be greater than 0"));
+        return -1;
+    }
+
+    *res = g_steal_pointer(&def);
+    return 0;
 }
 
 static virDomainVideoDriverDefPtr
@@ -15458,7 +15470,11 @@ virDomainVideoDefParseXML(virDomainXMLOptionPtr xmlopt,
                 }
 
                 def->accel = virDomainVideoAccelDefParseXML(cur);
-                def->res = virDomainVideoResolutionDefParseXML(cur);
+                if (virDomainVideoResolutionDefParseXML(cur, &def->res) < 0) {
+                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                                   "%s", _("Cannot parse video resolution"));
+                    goto error;
+                }
             }
             if (virXMLNodeNameEqual(cur, "driver")) {
                 if (virDomainVirtioOptionsParseXML(cur, &def->virtio) < 0)
-- 
2.21.0