From 29dda184e56ce3a1ec72db4612198f6b3ba84e82 Mon Sep 17 00:00:00 2001
From: "Ondrej Zajicek (work)" <santiago@crfreenet.org>
Date: Wed, 5 Jan 2022 16:38:49 +0100
Subject: [PATCH] Conf: Fix parsing full-length IPv6 addresses

Lexer expression for bytestring was too loose, accepting also
full-length IPv6 addresses. It should be restricted such that
colon is used between every byte or never.

Fix the regex and also add some test cases for it.

Thanks to Alexander Zubkov for the bugreport
---
 conf/cf-lex.l    |  2 +-
 filter/test.conf | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index 704a1750..c9d2f5a5 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -255,7 +255,7 @@ WHITE [ \t]
   return IP4;
 }
 
-{XIGIT}{2}(:{XIGIT}{2}|{XIGIT}{2}){15,} {
+{XIGIT}{2}((:{XIGIT}{2}){15,}|({XIGIT}{2}){15,}) {
   char *s = yytext;
   size_t len = 0, i;
   struct bytestring *bytes;
diff --git a/filter/test.conf b/filter/test.conf
index 6a28e4b3..f902f99f 100644
--- a/filter/test.conf
+++ b/filter/test.conf
@@ -335,6 +335,26 @@ ip p;
 	p = 1234:5678::;
 	bt_assert(!p.is_v4);
 	bt_assert(p.mask(24) = 1234:5600::);
+
+	p = 1:2:3:4:5:6:7:8;
+	bt_assert(!p.is_v4);
+	bt_assert(format(p) = "1:2:3:4:5:6:7:8");
+	bt_assert(p.mask(64) = 1:2:3:4::);
+
+	p = 10:20:30:40:50:60:70:80;
+	bt_assert(!p.is_v4);
+	bt_assert(format(p) = "10:20:30:40:50:60:70:80");
+	bt_assert(p.mask(64) = 10:20:30:40::);
+
+	p = 1090:20a0:30b0:40c0:50d0:60e0:70f0:8000;
+	bt_assert(!p.is_v4);
+	bt_assert(format(p) = "1090:20a0:30b0:40c0:50d0:60e0:70f0:8000");
+	bt_assert(p.mask(64) = 1090:20a0:30b0:40c0::);
+
+	p = ::fffe:6:c0c:936d:88c7:35d3;
+	bt_assert(!p.is_v4);
+	bt_assert(format(p) = "::fffe:6:c0c:936d:88c7:35d3");
+	bt_assert(p.mask(64) = 0:0:fffe:6::);
 }
 
 bt_test_suite(t_ip, "Testing ip address");