Resolve RFC 6761 localhost names to loopback

net/base/net_util.cc

 // 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.
 
 #include "net/base/net_util.h"
 
 #include <errno.h>
 #include <string.h>
 
 #include <algorithm>
@@ skipping 712 matching lines @@
   }
 }
 
 int GetPortFromSockaddr(const struct sockaddr* address, socklen_t address_len) {
   const uint16_t* port_field = GetPortFieldFromSockaddr(address, address_len);
   if (!port_field)
     return -1;
   return base::NetToHost16(*port_field);
 }
 
+bool IsLocalhostHostname(const std::string& host, bool* isLocalhost6) {
+  std::string lowercased_host = base::StringToLowerASCII(host);
+  if (lowercased_host == "localhost6" ||
+      lowercased_host == "localhost6.localdomain6" ||
+      lowercased_host == "localhost6." ||
+      lowercased_host == "localhost6.localdomain6.") {
+    *isLocalhost6 = true;
+    return true;
+  }
+
+  if (lowercased_host == "localhost" ||
+      lowercased_host == "localhost.localdomain" ||
+      lowercased_host == "localhost." ||
+      lowercased_host == "localhost.localdomain." ||
+      IsLocalhostTLD(lowercased_host)) {
+    *isLocalhost6 = false;
+    return true;
+  }
+
+  return false;
+}
+
 bool IsLocalhost(const std::string& host) {
-  if (host == "localhost" || host == "localhost.localdomain" ||
-      host == "localhost6" || host == "localhost6.localdomain6" ||
-      IsLocalhostTLD(host))
+  bool isIPv6;
+  if (IsLocalhostHostname(host, &isIPv6))
     return true;
 
   IPAddressNumber ip_number;
   if (ParseIPLiteralToNumber(host, &ip_number)) {
     size_t size = ip_number.size();
     switch (size) {
       case kIPv4AddressSize: {
         IPAddressNumber localhost_prefix;
         localhost_prefix.push_back(127);
         for (int i = 0; i < 3; ++i) {
@@ skipping 51 matching lines @@
   };
   const std::string& host = url.host();
   for (const char* suffix : kGoogleHostSuffixes) {
     if (EndsWith(host, suffix, false))
       return true;
   }
   return false;
 }
 
 }  // namespace net