From 770b1d2b56d979202302a7dfd9ad38fd4825ac6c Mon Sep 17 00:00:00 2001
From: Jiri Denemark <jdenemar@redhat.com>
Date: Thu, 8 Dec 2016 14:05:16 +0100
Subject: [PATCH] conf: Make virNetworkIPDefParseXML a little bit saner

Iterating over all child nodes when we only support one instance of each
child is pretty weird. And it would even cause memory leaks if more
than one <tftp> element was specified.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/conf/network_conf.c | 36 ++++++++++++++----------------------
 1 file changed, 14 insertions(+), 22 deletions(-)

diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c
index aabf315c93..b6849ceab4 100644
--- a/src/conf/network_conf.c
+++ b/src/conf/network_conf.c
@@ -1501,7 +1501,8 @@ virNetworkIPDefParseXML(const char *networkName,
      * On failure clear it out, but don't free it.
      */
 
-    xmlNodePtr cur, save;
+    xmlNodePtr save;
+    xmlNodePtr dhcp;
     char *address = NULL, *netmask = NULL;
     unsigned long prefix = 0;
     int prefixRc;
@@ -1603,29 +1604,20 @@ virNetworkIPDefParseXML(const char *networkName,
         goto cleanup;
     }
 
-    cur = node->children;
-    while (cur != NULL) {
-        if (cur->type == XML_ELEMENT_NODE &&
-            xmlStrEqual(cur->name, BAD_CAST "dhcp")) {
-            if (virNetworkDHCPDefParseXML(networkName, cur, def) < 0)
-                goto cleanup;
-        } else if (cur->type == XML_ELEMENT_NODE &&
-                   xmlStrEqual(cur->name, BAD_CAST "tftp")) {
-            char *root;
+    if ((dhcp = virXPathNode("./dhcp[1]", ctxt)) &&
+        virNetworkDHCPDefParseXML(networkName, dhcp, def) < 0)
+        goto cleanup;
 
-            if (!VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET)) {
-                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
-                               _("Unsupported <tftp> element in an IPv6 element in network '%s'"),
-                               networkName);
-                goto cleanup;
-            }
-            if (!(root = virXMLPropString(cur, "root"))) {
-                cur = cur->next;
-                continue;
-            }
-            def->tftproot = (char *)root;
+    if (virXPathNode("./tftp[1]", ctxt)) {
+        if (!VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("Unsupported <tftp> element in an IPv6 element "
+                             "in network '%s'"),
+                           networkName);
+            goto cleanup;
         }
-        cur = cur->next;
+
+        def->tftproot = virXPathString("string(./tftp[1]/@root)", ctxt);
     }
 
     result = 0;