From 8c59707cba3bb889ed71afbf9ecd70b29ea81ccf Mon Sep 17 00:00:00 2001
From: "Joshua M. Boniface" <joshua@boniface.me>
Date: Fri, 24 Jan 2020 13:17:48 -0500
Subject: [PATCH] Prevent writing invalid XML to config

---
 client-api/api_lib/pvcapi_helper.py | 18 ++++++++++++++++--
 client-cli/pvc.py                   | 18 ++++++++++++++++--
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/client-api/api_lib/pvcapi_helper.py b/client-api/api_lib/pvcapi_helper.py
index d78406ab..8e1e1843 100755
--- a/client-api/api_lib/pvcapi_helper.py
+++ b/client-api/api_lib/pvcapi_helper.py
@@ -22,6 +22,7 @@
 
 import flask
 import json
+import lxml.etree as etree
 
 from distutils.util import strtobool
 
@@ -422,8 +423,15 @@ def vm_define(xml, node, limit, selector, autostart):
     """
     Define a VM from Libvirt XML in the PVC cluster.
     """
+    # Verify our XML is sensible
+    try:
+        xml_data = etree.fromstring(xml)
+        new_cfg = etree.tostring(xml_data, pretty_print=True).decode('utf8')
+    except Exception as e:
+        return {'message': 'Error: XML is malformed or incorrect: {}'.format(e)}, 400
+
     zk_conn = pvc_common.startZKConnection(config['coordinators'])
-    retflag, retdata = pvc_vm.define_vm(zk_conn, xml, node, limit, selector, autostart, profile=None)
+    retflag, retdata = pvc_vm.define_vm(zk_conn, new_cfg, node, limit, selector, autostart, profile=None)
     pvc_common.stopZKConnection(zk_conn)
 
     if retflag:
@@ -492,8 +500,14 @@ def vm_modify(name, restart, xml):
     """
     Modify a VM Libvirt XML in the PVC cluster.
     """
+    # Verify our XML is sensible
+    try:
+        xml_data = etree.fromstring(xml)
+        new_cfg = etree.tostring(xml_data, pretty_print=True).decode('utf8')
+    except Exception as e:
+        return {'message': 'Error: XML is malformed or incorrect: {}'.format(e)}, 400
     zk_conn = pvc_common.startZKConnection(config['coordinators'])
-    retflag, retdata = pvc_vm.modify_vm(zk_conn, name, restart, xml)
+    retflag, retdata = pvc_vm.modify_vm(zk_conn, name, restart, new_cfg)
     pvc_common.stopZKConnection(zk_conn)
 
     if retflag:
diff --git a/client-cli/pvc.py b/client-cli/pvc.py
index aca81a4b..2e213dd1 100755
--- a/client-cli/pvc.py
+++ b/client-cli/pvc.py
@@ -521,7 +521,14 @@ def vm_define(vmconfig, target_node, node_limit, node_selector, node_autostart):
     vmconfig_data = vmconfig.read()
     vmconfig.close()
 
-    retcode, retmsg = pvc_vm.define_vm(config, vmconfig_data, target_node, node_limit, node_selector, node_autostart)
+    # Verify our XML is sensible
+    try:
+        xml_data = etree.fromstring(vmconfig_data)
+        new_cfg = etree.tostring(xml_data, pretty_print=True).decode('utf8')
+    except:
+        cleanup(False, 'Error: XML is malformed or invalid')
+
+    retcode, retmsg = pvc_vm.define_vm(config, new_cfg, target_node, node_limit, node_selector, node_autostart)
     cleanup(retcode, retmsg)
 
 ###############################################################################
@@ -634,7 +641,14 @@ def vm_modify(domain, cfgfile, editor, restart):
         else:
             click.echo('Replacing configuration of VM "{}" with file "{}".'.format(dom_name, cfgfile.name))
 
-    retcode, retmsg = pvc_vm.vm_modify(config, domain, new_vm_cfgfile, restart)
+    # Verify our XML is sensible
+    try:
+        xml_data = etree.fromstring(new_vm_cfgfile)
+        new_cfg = etree.tostring(xml_data, pretty_print=True).decode('utf8')
+    except Exception as e:
+        cleanup(False, 'Error: XML is malformed or invalid: {}'.format(e))
+
+    retcode, retmsg = pvc_vm.vm_modify(config, domain, new_cfg, restart)
     cleanup(retcode, retmsg)
 
 ###############################################################################