From 9fe6a3df3676c9ab8587e8a77d4d28896dc65d07 Mon Sep 17 00:00:00 2001
From: BenjiReis <benjamin.reis@vates.fr>
Date: Thu, 25 Feb 2021 09:54:52 +0100
Subject: [PATCH] If no NFS ACLs provided, assume everyone:

Some QNAP devices do not provide ACL when fetching NFS mounts.
In this case the assumed ACL should be: "*".

This commit fixes the crash when attempting to access the non existing ACL.
Relevant issues:
- https://github.com/xapi-project/sm/issues/511
- https://github.com/xcp-ng/xcp/issues/113
---
 drivers/nfs.py    |  6 +++++-
 tests/test_nfs.py | 30 ++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/nfs.py b/drivers/nfs.py
index 23dca2870..80b71a52a 100644
--- a/drivers/nfs.py
+++ b/drivers/nfs.py
@@ -202,7 +202,11 @@ def scan_exports(target):
         textnode = dom.createTextNode(target)
         subentry.appendChild(textnode)
 
-        (path, access) = val.split()
+        # Access is not always provided by showmount return
+        # If none is provided we need to assume "*"
+        array = val.split()
+        path = array[0]
+        access = array[1] if len(array) >= 2 else "*"
         subentry = dom.createElement("Path")
         entry.appendChild(subentry)
         textnode = dom.createTextNode(path)
diff --git a/tests/test_nfs.py b/tests/test_nfs.py
index 71800ab0a..cef414fe6 100644
--- a/tests/test_nfs.py
+++ b/tests/test_nfs.py
@@ -140,3 +140,33 @@ def test_validate_nfsversion_valid(self):
         for thenfsversion in ['3', '4', '4.1']:
             self.assertEquals(nfs.validate_nfsversion(thenfsversion),
                               thenfsversion)
+
+    # Can't use autospec due to http://bugs.python.org/issue17826
+    @mock.patch('util.pread2')
+    def test_scan_exports(self, pread2):
+        pread2.side_effect = ["/srv/nfs\n/srv/nfs2 *\n/srv/nfs3 127.0.0.1/24"]
+        res = nfs.scan_exports('aServer')
+
+        expected = """<?xml version="1.0" ?>
+<nfs-exports>
+\t<Export>
+\t\t<Target>aServer</Target>
+\t\t<Path>/srv/nfs</Path>
+\t\t<Accesslist>*</Accesslist>
+\t</Export>
+\t<Export>
+\t\t<Target>aServer</Target>
+\t\t<Path>/srv/nfs2</Path>
+\t\t<Accesslist>*</Accesslist>
+\t</Export>
+\t<Export>
+\t\t<Target>aServer</Target>
+\t\t<Path>/srv/nfs3</Path>
+\t\t<Accesslist>127.0.0.1/24</Accesslist>
+\t</Export>
+</nfs-exports>
+"""
+
+        self.assertEqual(res.toprettyxml(), expected)
+        self.assertEqual(len(pread2.mock_calls), 1)
+        pread2.assert_called_with(['/usr/sbin/showmount', '--no-headers', '-e', 'aServer'])