Add IPv6 DNS mappings

[hcoop/domtool2.git] / src / domain.sml

diff --git a/src/domain.sml b/src/domain.sml
index 94eb077..8384f85 100644 (file)
--- a/src/domain.sml
+++ b/src/domain.sml
@@ -80,6 +80,36 @@ fun validIp s =
        n1 >= 0 andalso n1 < 256 andalso n2 >= 0 andalso n2 < 256 andalso n3 >= 0 andalso n3 < 256 andalso n4 >= 0 andalso n4 < 256
       | _ => false
 
+fun isHexDigit ch = Char.isDigit ch orelse (ord ch >= ord #"a" andalso ord ch <= ord #"f")
+
+fun validIpv6 s =
+    let
+       val fields = String.fields (fn ch => ch = #":") s
+
+       val empties = foldl (fn ("", n) => n + 1
+                             | (_, n) => n) 0 fields
+
+       fun noIpv4 maxLen =
+           length fields >= 2
+           andalso length fields <= maxLen
+           andalso empties <= 1
+           andalso List.all (fn "" => true
+                              | s => size s <= 4
+                                     andalso CharVector.all isHexDigit s) fields
+
+       fun hasIpv4 () =
+           length fields > 0
+           andalso
+           let
+               val maybeIpv4 = List.last fields
+               val theRest = List.take (fields, length fields - 1)
+           in
+               validIp maybeIpv4 andalso noIpv4 6
+           end
+    in
+       noIpv4 8 orelse hasIpv4 ()
+    end
+
 fun isIdent ch = Char.isLower ch orelse Char.isDigit ch
 
 fun validHost s =
@@ -143,6 +173,10 @@ val _ = Env.type_one "ip"
        Env.string
        validIp
 
+val _ = Env.type_one "ipv6"
+       Env.string
+       validIpv6
+
 val _ = Env.type_one "host"
        Env.string
        validHost