From 3f097341ec5756f7f1cbc2f4f1a66eaa337e72ec Mon Sep 17 00:00:00 2001
From: Clinton Ebadi <clinton@unknownlamer.org>
Date: Thu, 27 Feb 2020 21:27:01 -0500
Subject: [PATCH] domain: fix validIpv6 predicate

Reject invalid IPs in format ":x" ("::" was already disallowed, so no
harm in requiring at least three segments), and allow localhost "::1"
as a valid format.

This completes the fix fwtool IPv6 LocalServer rule generation.
---
 src/domain.sml | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/domain.sml b/src/domain.sml
index a84a6d8..15bc8b7 100644
--- a/src/domain.sml
+++ b/src/domain.sml
@@ -107,7 +107,7 @@ fun validIpv6 s =
 			      | (_, n) => n) 0 fields
 
 	fun noIpv4 maxLen =
-	    length fields >= 2
+	    length fields >= 3
 	    andalso length fields <= maxLen
 	    andalso empties <= 1
 	    andalso List.all (fn "" => true
@@ -123,8 +123,13 @@ fun validIpv6 s =
 	    in
 		validIp maybeIpv4 andalso noIpv4 6
 	    end
+
+	fun localHost () =
+	    length fields = 3
+	    andalso empties = 2
+	    andalso List.last fields = "1"
     in
-	noIpv4 8 orelse hasIpv4 ()
+	localHost () orelse noIpv4 8 orelse hasIpv4 ()
     end
 
 fun isIdent ch = Char.isLower ch orelse Char.isDigit ch
-- 
2.20.1