From: Maria Matejka <mq@ucw.cz>
Date: Tue, 13 Jun 2023 09:09:41 +0000 (+0200)
Subject: Conf: Allowing conf scope to be explicitly read only
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=317c89cc8abdada9cd90f844b6b1801651d92e76;p=thirdparty%2Fbird.git

Conf: Allowing conf scope to be explicitly read only
---

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index d1cc4ed9e..04a6c9945 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -570,6 +570,9 @@ static inline void cf_swap_soft_scope(struct config *conf);
 static struct symbol *
 cf_new_symbol(struct sym_scope *scope, pool *p, struct linpool *lp, const byte *c)
 {
+  if (scope->readonly)
+    cf_error("Unknown symbol %s", c);
+
   struct symbol *s;
 
   uint l = strlen(c);
@@ -723,6 +726,8 @@ cf_lex_init(int is_cli, struct config *c)
       sym->class = SYM_KEYWORD;
       sym->keyword = k;
     }
+
+    global_root_scope->readonly = 1;
   }
 
   ifs_head = ifs = push_ifs(NULL);
diff --git a/conf/conf.h b/conf/conf.h
index ec8c97e84..8558fcbae 100644
--- a/conf/conf.h
+++ b/conf/conf.h
@@ -137,9 +137,10 @@ struct sym_scope {
   HASH(struct symbol) hash;		/* Local symbol hash */
 
   uint slots;				/* Variable slots */
-  byte active;				/* Currently entered */
-  byte block;				/* No independent stack frame */
   byte soft_scopes;			/* Number of soft scopes above */
+  byte active:1;			/* Currently entered */
+  byte block:1;				/* No independent stack frame */
+  byte readonly:1;			/* Do not add new symbols */
 };
 
 extern struct sym_scope *global_root_scope;