Add three of the six extensions to PAC that Internet Explorer supports.

The following descriptions were taken from <http://blogs.msdn.com/wndp/articles/IPV6_PAC_Extensions_v0_9.aspx> 

---------------------------- 
* myIpAddressEx(): 
Returns a semi-colon delimited string containing all IP addresses for localhost (IPv6 and/or IPv4), or an empty string if unable to resolve localhost to an IP address. 

* dnsResolveEx(host): 
Returns semi-colon delimited string containing IPv6 and IPv4 addresses or an empty string if host is not resolvable. 

* isResolvableEx(): 
Returns TRUE if the host is resolvable to a IPv4 or IPv6 address, FALSE otherwise. 
---------------------------- 

These differ from the vanilla PAC functions in the following ways: 

* myIpAddressEx() returns all the addrsses for localhost (including IPv6 ones), whereas myIpAddress() only returns the first IPv4 one. 
* On failure, myIpAddress() returns "127.0.0.1" whereas on failure myIpAddressEx() returns empty string. 
* dnsResolveEx() returns a list of addresses (including IPV6 ones), whereas dnsResolve() only returns the first IPv4 address. 
* On failure, dnsResolve() returns |null|, whereas on failure dnsResolveEx() returns empty string. 

BUG=25407
TEST=ProxyResolverV8Test.DNSResolutionFailure, ProxyResolverJSBindingsTest.RestrictAddressFamily, ProxyResolverJSBindingsTest.ExFunctionsReturnList
Review URL: http://codereview.chromium.org/333006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@30127 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 43 insertions, 7 deletions

diff --git a/net/proxy/proxy_resolver_js_bindings.cc b/net/proxy/proxy_resolver_js_bindings.cc
index f9ea5ae..077e5c6 100644
--- a/net/proxy/proxy_resolver_js_bindings.cc
+++ b/net/proxy/proxy_resolver_js_bindings.cc
@@ -2,6 +2,14 @@
 // source code is governed by a BSD-style license that can be found in the
 // LICENSE file.
 
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
+#include <ws2tcpip.h>
+#else
+#include <netdb.h>
+#endif
+
 #include "net/proxy/proxy_resolver_js_bindings.h"
 
 #include "base/compiler_specific.h"
@@ -97,21 +105,24 @@ class DefaultJSBindings : public ProxyResolverJSBindings {
   }
 
   // Handler for "myIpAddress()". Returns empty string on failure.
+  // TODO(eroman): Perhaps enumerate the interfaces directly, using
+  // getifaddrs().
   virtual std::string MyIpAddress() {
     // DnsResolve("") returns "", so no need to check for failure.
     return DnsResolve(GetHostName());
   }
 
+  // Handler for "myIpAddressEx()". Returns empty string on failure.
+  virtual std::string MyIpAddressEx() {
+    return DnsResolveEx(GetHostName());
+  }
+
   // Handler for "dnsResolve(host)". Returns empty string on failure.
   virtual std::string DnsResolve(const std::string& host) {
-    // TODO(eroman): Should this return our IP address, or fail, or
-    // simply be unspecified (works differently on windows and mac os x).
-    if (host.empty())
-      return std::string();
-
     // Do a sync resolve of the hostname.
-    // Disable IPv6 results. We do this because Internet Explorer does it --
-    // consequently a lot of existing PAC scripts assume they will only get
+    // Disable IPv6 results. We do this because the PAC specification isn't
+    // really IPv6 friendly, and Internet Explorer also restricts to IPv4.
+    // Consequently a lot of existing PAC scripts assume they will only get
     // IPv4 results, and will misbehave if they get an IPv6 result.
     // See http://crbug.com/24641 for more details.
     net::AddressList address_list;
@@ -130,6 +141,31 @@ class DefaultJSBindings : public ProxyResolverJSBindings {
     return net::NetAddressToString(address_list.head());
   }
 
+  // Handler for "dnsResolveEx(host)". Returns empty string on failure.
+  virtual std::string DnsResolveEx(const std::string& host) {
+    // Do a sync resolve of the hostname.
+    net::AddressList address_list;
+    int result = host_resolver_->Resolve(host,
+                                         ADDRESS_FAMILY_UNSPECIFIED,
+                                         &address_list);
+
+    if (result != OK)
+      return std::string();  // Failed.
+
+    // Stringify all of the addresses in the address list, separated
+    // by semicolons.
+    std::string address_list_str;
+    const struct addrinfo* current_address = address_list.head();
+    while (current_address) {
+      if (!address_list_str.empty())
+        address_list_str += ";";
+      address_list_str += net::NetAddressToString(current_address);
+      current_address = current_address->ai_next;
+    }
+
+    return address_list_str;
+  }
+
   // Handler for when an error is encountered. |line_number| may be -1.
   virtual void OnError(int line_number, const std::string& message) {
     if (line_number == -1)