[PATCH 01/25] virXMLParseHelper: Add root XML node name validation capability

[Peter Krempa]

Some callers want to validate the root XML node name. Add the capability
to the parser helper to prevent open-coding.

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/util/virxml.c | 18 ++++++++++++++++--
 src/util/virxml.h | 13 +++++++------
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/src/util/virxml.c b/src/util/virxml.c
index 83644af8ce..d0d9494009 100644
--- a/src/util/virxml.c
+++ b/src/util/virxml.c
@@ -1020,11 +1020,15 @@ catchXMLError(void *ctx, const char *msg G_GNUC_UNUSED, ...)
  * @filename: file to be parsed or NULL if string parsing is requested
  * @xmlStr: XML string to be parsed in case filename is NULL
  * @url: URL of XML document for string parser
+ * @rootelement: Optional name of the expected root element
  * @ctxt: optional pointer to populate with new context pointer
  *
  * Parse XML document provided either as a file or a string. The function
  * guarantees that the XML document contains a root element.
  *
+ * If @rootelement is not NULL, the name of the root element of the parsed XML
+ * is vaidated against
+ *
  * Returns parsed XML document.
  */
 xmlDocPtr
@@ -1032,11 +1036,13 @@ virXMLParseHelper(int domcode,
                   const char *filename,
                   const char *xmlStr,
                   const char *url,
+                  const char *rootelement,
                   xmlXPathContextPtr *ctxt)
 {
     struct virParserData private;
     g_autoptr(xmlParserCtxt) pctxt = NULL;
     g_autoptr(xmlDoc) xml = NULL;
+    xmlNodePtr rootnode;
     const char *docname;

     if (filename)
@@ -1075,18 +1081,26 @@ virXMLParseHelper(int domcode,
         return NULL;
     }

-    if (xmlDocGetRootElement(xml) == NULL) {
+    if (!(rootnode = xmlDocGetRootElement(xml))) {
         virGenericReportError(domcode, VIR_ERR_INTERNAL_ERROR,
                               "%s", _("missing root element"));

         return NULL;
     }

+    if (rootelement &&
+        !virXMLNodeNameEqual(rootnode, rootelement)) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("expecting root element of '%s', not '%s'"),
+                       rootelement, rootnode->name);
+        return NULL;
+    }
+
     if (ctxt) {
         if (!(*ctxt = virXMLXPathContextNew(xml)))
             return NULL;

-        (*ctxt)->node = xmlDocGetRootElement(xml);
+        (*ctxt)->node = rootnode;
     }

     return g_steal_pointer(&xml);
diff --git a/src/util/virxml.h b/src/util/virxml.h
index 022ead58b5..38da2931a4 100644
--- a/src/util/virxml.h
+++ b/src/util/virxml.h
@@ -150,6 +150,7 @@ virXMLParseHelper(int domcode,
                   const char *filename,
                   const char *xmlStr,
                   const char *url,
+                  const char *rootelement,
                   xmlXPathContextPtr *ctxt);

 const char *
@@ -166,7 +167,7 @@ virXMLPickShellSafeComment(const char *str1,
  * Return the parsed document object, or NULL on failure.
  */
 #define virXMLParse(filename, xmlStr, url) \
-    virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url, NULL)
+    virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url, NULL, NULL)

 /**
  * virXMLParseString:
@@ -178,7 +179,7 @@ virXMLPickShellSafeComment(const char *str1,
  * Return the parsed document object, or NULL on failure.
  */
 #define virXMLParseString(xmlStr, url) \
-    virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, NULL)
+    virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, NULL, NULL)

 /**
  * virXMLParseFile:
@@ -189,7 +190,7 @@ virXMLPickShellSafeComment(const char *str1,
  * Return the parsed document object, or NULL on failure.
  */
 #define virXMLParseFile(filename) \
-    virXMLParseHelper(VIR_FROM_THIS, filename, NULL, NULL, NULL)
+    virXMLParseHelper(VIR_FROM_THIS, filename, NULL, NULL, NULL, NULL)

 /**
  * virXMLParseCtxt:
@@ -204,7 +205,7 @@ virXMLPickShellSafeComment(const char *str1,
  * Return the parsed document object, or NULL on failure.
  */
 #define virXMLParseCtxt(filename, xmlStr, url, pctxt) \
-    virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url, pctxt)
+    virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url, NULL, pctxt)

 /**
  * virXMLParseStringCtxt:
@@ -218,7 +219,7 @@ virXMLPickShellSafeComment(const char *str1,
  * Return the parsed document object, or NULL on failure.
  */
 #define virXMLParseStringCtxt(xmlStr, url, pctxt) \
-    virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, pctxt)
+    virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, NULL, pctxt)

 /**
  * virXMLParseFileCtxt:
@@ -231,7 +232,7 @@ virXMLPickShellSafeComment(const char *str1,
  * Return the parsed document object, or NULL on failure.
  */
 #define virXMLParseFileCtxt(filename, pctxt) \
-    virXMLParseHelper(VIR_FROM_THIS, filename, NULL, NULL, pctxt)
+    virXMLParseHelper(VIR_FROM_THIS, filename, NULL, NULL, NULL, pctxt)

 int
 virXMLSaveFile(const char *path,
-- 
2.30.2