Refuse to resolve some types of invalid DNS addresses.

net/dns/dns_util.cc

Index: net/dns/dns_util.cc
diff --git a/net/dns/dns_util.cc b/net/dns/dns_util.cc
index 48be035c0e3380d37f5aa0d29e3406760b97db6d..716fb685daefd054129e30974a425f44919b2a3b 100644
--- a/net/dns/dns_util.cc
+++ b/net/dns/dns_util.cc
@@ -33,6 +33,10 @@ namespace net {
 
 // Based on DJB's public domain code.
 bool DNSDomainFromDot(const base::StringPiece& dotted, std::string* out) {
+  // Refuse to convert invalid host names.

[Julia Tuttle, 2016/09/09 20:24:38]

This is commented out; remove it?

[mmenke, 2016/09/09 20:38:44]

Oops, thanks!  I hadn't realized this was actually the method used to check
hostname validity, initially.

+  // if (!IsHostnameValid(dotted))
+  //  return false;
+
   const char* buf = dotted.data();
   unsigned n = dotted.size();
   char label[63];
@@ -83,6 +87,11 @@ bool DNSDomainFromDot(const base::StringPiece& dotted, std::string* out) {
   return true;
 }
 
+bool IsValidDNSDomain(const base::StringPiece& dotted) {
+  std::string dns_formatted;
+  return DNSDomainFromDot(dotted, &dns_formatted);
+}
+
 std::string DNSDomainToString(const base::StringPiece& domain) {
   std::string ret;