SuffixMatchTree: Fix partial match of non-leaf nodes

If we insert fr and www.domain.fr, domain.fr should not match
www.domain.fr, the leaf node, and it should not match the
intermediary domain.fr node, but it should match the fr
end-node.

(cherry picked from commit 99517c1b39226e50e1eb1a5a6509844fb57e9e68)

diff --git a/pdns/dnsname.hh b/pdns/dnsname.hh
index e5f6b11dbbaa639f51910068aa47ee3dca260c84..ab2e0aad4ec1a829175c31b5ce6194d03f37f7d9 100644 (file)
--- a/pdns/dnsname.hh
+++ b/pdns/dnsname.hh
@@ -328,9 +328,14 @@ struct SuffixMatchTree
     if(children.empty()) { // speed up empty set
       if(endNode)
         return &d_value;
-      return 0;
+      return nullptr;
     }
-    return lookup(name.getRawLabels());
+
+    auto result = lookup(name.getRawLabels());
+    if (result) {
+      return result;
+    }
+    return endNode ? &d_value : nullptr;
   }
 
   T* lookup(std::vector<std::string> labels) const
@@ -338,7 +343,7 @@ struct SuffixMatchTree
     if(labels.empty()) { // optimization
       if(endNode)
         return &d_value;
-      return 0;
+      return nullptr;
     }
 
     SuffixMatchTree smn(*labels.rbegin());
@@ -346,10 +351,14 @@ struct SuffixMatchTree
     if(child == children.end()) {
       if(endNode)
         return &d_value;
-      return 0;
+      return nullptr;
     }
     labels.pop_back();
-    return child->lookup(labels);
+    auto result = child->lookup(labels);
+    if (result) {
+      return result;
+    }
+    return endNode ? &d_value : nullptr;
   }
 
   // Returns all end-nodes, fully qualified (not as separate labels)

diff --git a/pdns/test-dnsname_cc.cc b/pdns/test-dnsname_cc.cc
index 833f2fc31e434015d6072e894969275d5220b663..2e8ecf3313e94855d3de49cf85046b5e2b6067a8 100644 (file)
--- a/pdns/test-dnsname_cc.cc
+++ b/pdns/test-dnsname_cc.cc
@@ -508,10 +508,16 @@ BOOST_AUTO_TEST_CASE(test_suffixmatch) {
   BOOST_CHECK(smn.check(examplenet));
   BOOST_CHECK(smn.check(net));
 
-  // Remove .net and check that example.net still exists
+  // Remove .net and the root, and check that example.net still exists
+  smn.remove(g_rootdnsname);
   smn.remove(net);
   BOOST_CHECK_EQUAL(smn.check(net), false);
   BOOST_CHECK(smn.check(examplenet));
+
+  smn.add(DNSName("fr."));
+  smn.add(DNSName("www.sub.domain.fr."));
+  // should not match www.sub.domain.fr. but should still match fr.
+  BOOST_CHECK(smn.check(DNSName("sub.domain.fr.")));
 }
 
 BOOST_AUTO_TEST_CASE(test_suffixmatch_tree) {
@@ -564,7 +570,8 @@ BOOST_AUTO_TEST_CASE(test_suffixmatch_tree) {
   BOOST_REQUIRE(smt.lookup(net));
   BOOST_CHECK_EQUAL(*smt.lookup(net), net);
 
-  // Remove .net, and check that example.net remains
+  // Remove .net and the root, and check that example.net remains
+  smt.remove(g_rootdnsname);
   smt.remove(net);
   BOOST_CHECK(smt.lookup(net) == nullptr);
   BOOST_CHECK_EQUAL(*smt.lookup(examplenet), examplenet);