From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Fri, 17 Feb 2023 13:30:50 +0000 (+0100)
Subject: dnsdist: Ensure we have at least one protobuf MetaValue
X-Git-Tag: dnsdist-1.8.0-rc1~2^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F12561%2Fhead;p=thirdparty%2Fpdns.git

dnsdist: Ensure we have at least one protobuf MetaValue
---

diff --git a/pdns/dnsdist-protobuf.cc b/pdns/dnsdist-protobuf.cc
index c1250ba154..3eb5b82d92 100644
--- a/pdns/dnsdist-protobuf.cc
+++ b/pdns/dnsdist-protobuf.cc
@@ -197,7 +197,13 @@ void DNSDistProtoBufMessage::serialize(std::string& data) const
   m.commitResponse();
 
   for (const auto& [key, values] : d_metaTags) {
-    m.setMeta(key, values, {});
+    if (!values.empty()) {
+      m.setMeta(key, values, {});
+    }
+    else {
+      /* the MetaValue field is _required_ to exist, even if we have no value */
+      m.setMeta(key, {std::string()}, {});
+    }
   }
 }
 
diff --git a/regression-tests.dnsdist/test_Protobuf.py b/regression-tests.dnsdist/test_Protobuf.py
index fead59012a..eee259b048 100644
--- a/regression-tests.dnsdist/test_Protobuf.py
+++ b/regression-tests.dnsdist/test_Protobuf.py
@@ -551,12 +551,8 @@ class TestProtobufMetaDOH(DNSDistProtobufTest):
             self.assertEqual(len(msg.meta), 5)
             tags = {}
             for entry in msg.meta:
-                if method == "sendDOHQueryWrapper":
-                    self.assertEqual(len(entry.value.stringVal), 1)
-                    tags[entry.key] = entry.value.stringVal[0]
-                else:
-                    self.assertEqual(len(entry.value.stringVal), 0)
-                    tags[entry.key] = None
+                self.assertEqual(len(entry.value.stringVal), 1)
+                tags[entry.key] = entry.value.stringVal[0]
 
             self.assertIn('agent', tags)
             if method == "sendDOHQueryWrapper":
@@ -576,12 +572,8 @@ class TestProtobufMetaDOH(DNSDistProtobufTest):
             self.assertEqual(len(msg.meta), 5)
             tags = {}
             for entry in msg.meta:
-                if method == "sendDOHQueryWrapper":
-                    self.assertEqual(len(entry.value.stringVal), 1)
-                    tags[entry.key] = entry.value.stringVal[0]
-                else:
-                    self.assertEqual(len(entry.value.stringVal), 0)
-                    tags[entry.key] = None
+                self.assertEqual(len(entry.value.stringVal), 1)
+                tags[entry.key] = entry.value.stringVal[0]
 
             self.assertIn('agent', tags)
             if method == "sendDOHQueryWrapper":