Refuse to resolve some types of invalid DNS addresses.

net/dns/dns_util.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_DNS_DNS_UTIL_H_
 #define NET_DNS_DNS_UTIL_H_
 
 #include <string>
 
 #include "base/strings/string_piece.h"
 #include "base/time/time.h"
 #include "net/base/net_export.h"
 #include "net/base/network_change_notifier.h"
 
 namespace net {
 
 class AddressList;
 
 // DNSDomainFromDot - convert a domain string to DNS format. From DJB's
 // public domain DNS library.
 //
 //   dotted: a string in dotted form: "www.google.com"
 //   out: a result in DNS form: "\x03www\x06google\x03com\x00"
 NET_EXPORT_PRIVATE bool DNSDomainFromDot(const base::StringPiece& dotted,
                                          std::string* out);
 
+// Checks that a hostname is valid. Simple wrapper around DNSDomainFromDot.
+NET_EXPORT_PRIVATE bool IsValidDNSDomain(const base::StringPiece& dotted);
+
 // DNSDomainToString converts a domain in DNS format to a dotted string.
 // Excludes the dot at the end.
 NET_EXPORT_PRIVATE std::string DNSDomainToString(
     const base::StringPiece& domain);
 
 // Returns true if it can determine that only loopback addresses are configured.
 // i.e. if only 127.0.0.1 and ::1 are routable.
 // Also returns false if it cannot determine this.
 NET_EXPORT_PRIVATE bool HaveOnlyLoopbackAddresses();
 
@@ skipping 20 matching lines @@
 };
 
 // Compares two AddressLists to see how similar or different their addresses
 // are. (See |AddressListDeltaType| for details of exactly what's checked.)
 AddressListDeltaType FindAddressListDeltaType(const AddressList& a,
                                               const AddressList& b);
 
 }  // namespace net
 
 #endif  // NET_DNS_DNS_UTIL_H_