From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Tue, 10 Nov 2020 11:39:13 +0000 (+0100)
Subject: rec: Add unit tests for Extended DNS Errors
X-Git-Tag: auth-4.4.0-beta1~2^2~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b780f8128bc10374086dc86a7fb073f8dc5d9fb6;p=thirdparty%2Fpdns.git

rec: Add unit tests for Extended DNS Errors
---

diff --git a/pdns/recursordist/Makefile.am b/pdns/recursordist/Makefile.am
index eb8fc7c39b..141fcf5780 100644
--- a/pdns/recursordist/Makefile.am
+++ b/pdns/recursordist/Makefile.am
@@ -243,6 +243,7 @@ testrunner_SOURCES = \
 	dnsseckeeper.hh \
 	dnswriter.cc dnswriter.hh \
 	ednscookies.cc ednscookies.hh \
+	ednsextendederror.cc ednsextendederror.hh \
 	ednsoptions.cc ednsoptions.hh \
 	ednssubnet.cc ednssubnet.hh \
 	filterpo.cc filterpo.hh \
diff --git a/pdns/recursordist/ednsextendederror.cc b/pdns/recursordist/ednsextendederror.cc
index 62d3bcc584..9903a0770f 100644
--- a/pdns/recursordist/ednsextendederror.cc
+++ b/pdns/recursordist/ednsextendederror.cc
@@ -38,7 +38,7 @@ static bool getEDNSExtendedErrorOptFromString(const pdns_string_view option, EDN
 
 bool getEDNSExtendedErrorOptFromString(const string& option, EDNSExtendedError& eee)
 {
-  return getEDNSExtendedErrorOptFromString(option, eee);
+  return getEDNSExtendedErrorOptFromString(pdns_string_view(option), eee);
 }
 
 bool getEDNSExtendedErrorOptFromString(const char* option, unsigned int len, EDNSExtendedError& eee)
@@ -48,6 +48,10 @@ bool getEDNSExtendedErrorOptFromString(const char* option, unsigned int len, EDN
 
 string makeEDNSExtendedErrorOptString(const EDNSExtendedError& eee)
 {
+  if (eee.extraText.size() > static_cast<size_t>(std::numeric_limits<uint16_t>::max() - 2)) {
+    throw std::runtime_error("Trying to create an EDNS Extended Error option with an extra text of size " + std::to_string(eee.extraText.size()));
+  }
+
   string ret;
   ret.reserve(sizeof(uint16_t) + eee.extraText.size());
   ret.resize(sizeof(uint16_t));
diff --git a/pdns/recursordist/test-ednsoptions_cc.cc b/pdns/recursordist/test-ednsoptions_cc.cc
index d653526d7a..433cb0b4c7 100644
--- a/pdns/recursordist/test-ednsoptions_cc.cc
+++ b/pdns/recursordist/test-ednsoptions_cc.cc
@@ -10,6 +10,7 @@
 #include "dnsname.hh"
 #include "dnswriter.hh"
 #include "ednscookies.hh"
+#include "ednsextendederror.hh"
 #include "ednsoptions.hh"
 #include "ednssubnet.hh"
 #include "iputils.hh"
@@ -162,7 +163,6 @@ static void checkECSOptionValidity(const std::string& sourceStr, uint8_t sourceM
 
 BOOST_AUTO_TEST_CASE(test_makeEDNSSubnetOptsString)
 {
-
   checkECSOptionValidity("192.0.2.255", 0, 0);
   checkECSOptionValidity("192.0.2.255", 8, 0);
   checkECSOptionValidity("255.255.255.255", 9, 0);
@@ -174,4 +174,42 @@ BOOST_AUTO_TEST_CASE(test_makeEDNSSubnetOptsString)
   checkECSOptionValidity("2001:DB8::FFFF", 128, 0);
 }
 
+static void checkExtendedErrorOptionValidity(EDNSExtendedError::code code, const std::string& extra)
+{
+  EDNSExtendedError eee;
+  eee.infoCode = static_cast<uint16_t>(code);
+  eee.extraText = extra;
+
+  const auto optionStr = makeEDNSExtendedErrorOptString(eee);
+  BOOST_REQUIRE_EQUAL(optionStr.size(), sizeof(code) + extra.size());
+
+  uint16_t u;
+  memcpy(&u, optionStr.c_str(), sizeof(u));
+  BOOST_CHECK_EQUAL(ntohs(u), static_cast<uint16_t>(code));
+  BOOST_CHECK_EQUAL(optionStr.substr(2), extra);
+
+  EDNSExtendedError parsed;
+  BOOST_REQUIRE(getEDNSExtendedErrorOptFromString(optionStr, parsed));
+  BOOST_CHECK_EQUAL(parsed.infoCode, static_cast<uint16_t>(code));
+  BOOST_CHECK_EQUAL(parsed.extraText, extra);
+}
+
+BOOST_AUTO_TEST_CASE(test_makeEDNSExtendedErrorOptString)
+{
+  checkExtendedErrorOptionValidity(EDNSExtendedError::code::Other, "");
+  checkExtendedErrorOptionValidity(static_cast<EDNSExtendedError::code>(255), "");
+
+  checkExtendedErrorOptionValidity(EDNSExtendedError::code::UnsupportedDNSKEYAlgorithm, "");
+  checkExtendedErrorOptionValidity(EDNSExtendedError::code::UnsupportedDSDigestType, "The digest type of this DS is not supported!");
+
+  std::string extra;
+  /* the size of an EDNS option is limited to 2^16-1, and in this case the code already adds 2 bytes */
+  extra.resize(65535);
+  BOOST_CHECK_THROW(checkExtendedErrorOptionValidity(EDNSExtendedError::code::Other, extra), std::runtime_error);
+
+  EDNSExtendedError parsed;
+  std::string empty;
+  BOOST_CHECK(!getEDNSExtendedErrorOptFromString(empty, parsed));
+}
+
 BOOST_AUTO_TEST_SUITE_END()