From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Thu, 5 Mar 2020 09:04:50 +0000 (+0100)
Subject: dnsdist: Debug trailing data failures
X-Git-Tag: auth-4.4.0-alpha2~65^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F9556%2Fhead;p=thirdparty%2Fpdns.git

dnsdist: Debug trailing data failures
---

diff --git a/pdns/dnsdist.cc b/pdns/dnsdist.cc
index ac24be4c58..953bfbe2fd 100644
--- a/pdns/dnsdist.cc
+++ b/pdns/dnsdist.cc
@@ -204,12 +204,13 @@ bool DNSQuestion::setTrailingData(const std::string& tail)
   const uint16_t messageLen = getDNSPacketLength(message, this->len);
   const uint16_t tailLen = tail.size();
   if (tailLen > (this->size - messageLen)) {
+    vinfolog("Trailing data update failed, the new trailing data size was %d, the existing message length was %d, packet size was %d and buffer size %d", tail.size(), messageLen, this->len, this->size);
     return false;
   }
 
   /* Update length and copy data from the Lua string. */
   this->len = messageLen + tailLen;
-  if(tailLen > 0) {
+  if (tailLen > 0) {
     tail.copy(message + messageLen, tailLen);
   }
   return true;
diff --git a/regression-tests.dnsdist/dnsdisttests.py b/regression-tests.dnsdist/dnsdisttests.py
index 773d5732ff..3145830121 100644
--- a/regression-tests.dnsdist/dnsdisttests.py
+++ b/regression-tests.dnsdist/dnsdisttests.py
@@ -202,6 +202,7 @@ class DNSDistTest(AssertEqualDNSMessageMixin, unittest.TestCase):
             try:
                 request = dns.message.from_wire(data, ignore_trailing=ignoreTrailing)
             except dns.message.TrailingJunk as e:
+                print('trailing data exception in UDPResponder')
                 if trailingDataResponse is False or forceRcode is True:
                     raise
                 print("UDP query with trailing data, synthesizing response")
diff --git a/regression-tests.dnsdist/test_Trailing.py b/regression-tests.dnsdist/test_Trailing.py
index b87b519f7a..2de5580fb7 100644
--- a/regression-tests.dnsdist/test_Trailing.py
+++ b/regression-tests.dnsdist/test_Trailing.py
@@ -10,6 +10,7 @@ class TestTrailingDataToBackend(DNSDistTest):
     # responders allow trailing data and we don't want
     # to mix things up.
     _testServerPort = 5360
+    _verboseMode = True
     _config_template = """
     newServer{address="127.0.0.1:%s"}
 
@@ -163,6 +164,7 @@ class TestTrailingDataToBackend(DNSDistTest):
             self.assertEquals(receivedResponse, expectedResponse)
 
 class TestTrailingDataToDnsdist(DNSDistTest):
+    _verboseMode = True
     _config_template = """
     newServer{address="127.0.0.1:%s"}
 
@@ -171,6 +173,7 @@ class TestTrailingDataToDnsdist(DNSDistTest):
     function removeTrailingData(dq)
         local success = dq:setTrailingData("")
         if not success then
+            print("Trailing removal failed")
             return DNSAction.ServFail, ""
         end
         return DNSAction.None, ""