From 65d6a525944faa3f77041419991d77106d8f0a0d Mon Sep 17 00:00:00 2001
From: Alexander Zubkov <green@qrator.net>
Date: Fri, 23 Jun 2023 16:47:37 +0200
Subject: [PATCH] Add hex:XYZ syntax for short hex strings

Hexadecimal bytestring literals have minimal length to not collide
with IP addresses or regular (hexadecimal) number literals.

Allow to use shorter literals with explicit hex: prefix.
---
 conf/cf-lex.l | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index 9555949d..9025a84d 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -255,12 +255,17 @@ WHITE [ \t]
   return IP4;
 }
 
-{XIGIT}{2}((:{XIGIT}{2}){15,}|({XIGIT}{2}){15,}) {
-  char *s = yytext;
+({XIGIT}{2}){16,}|{XIGIT}{2}(:{XIGIT}{2}){15,}|hex:({XIGIT}{2}(:?{XIGIT}{2})*)? {
+  char *s, *sb = yytext;
   size_t len = 0, i;
   struct bytestring *bytes;
   byte *b;
 
+  /* skip 'hex:' prefix */
+  if (sb[0] == 'h' && sb[1] == 'e' && sb[2] == 'x' && sb[3] == ':')
+    sb += 4;
+
+  s = sb;
   while (*s) {
     len++;
     s += 2;
@@ -271,7 +276,7 @@ WHITE [ \t]
 
   bytes->length = len;
   b = &bytes->data[0];
-  s = yytext;
+  s = sb;
   errno = 0;
   for (i = 0; i < len; i++) {
     *b = bstrtobyte16(s);