Add support for IPv6 link local addresses to resolv

Now that it should work correctly, test that every address returned
by Socket.ip_address_list is resolvable.

Socket works with IPv6 link local addresses, and ipaddr now does
as well, so I think resolv should support them.

Fixes [Bug #17112]

1 files changed, 26 insertions, 1 deletions

diff --git a/lib/resolv.rb b/lib/resolv.rb
index d50940ad15..2c4f83d212 100644
--- a/lib/resolv.rb
+++ b/lib/resolv.rb
@@ -2460,13 +2460,38 @@ class Resolv
       \z/x
 
     ##
+    # IPv6 link local address format fe80:b:c:d:e:f:g:h%em1
+    Regex_8HexLinkLocal = /\A
+      fe80
+      (?::[0-9A-Fa-f]{1,4}){7}
+      %[0-9A-Za-z]+
+      \z/x
+
+    ##
+    # Compressed IPv6 link local address format fe80::b%em1
+
+    Regex_CompressedHexLinkLocal = /\A
+      fe80:
+      (?:
+        ((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?) ::
+        ((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)
+        |
+        :((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)
+      )?
+      :[0-9A-Fa-f]{1,4}%[0-9A-Za-z]+
+      \z/x
+
+    ##
     # A composite IPv6 address Regexp.
 
     Regex = /
       (?:#{Regex_8Hex}) |
       (?:#{Regex_CompressedHex}) |
       (?:#{Regex_6Hex4Dec}) |
-      (?:#{Regex_CompressedHex4Dec})/x
+      (?:#{Regex_CompressedHex4Dec}) |
+      (?:#{Regex_8HexLinkLocal}) |
+      (?:#{Regex_CompressedHexLinkLocal})
+      /x
 
     ##
     # Creates a new IPv6 address from +arg+ which may be: