[master] e5d6a0f4a vcc: Give the REGEX treatment to ACL expressions

[Dridi Boukelmoune]

commit e5d6a0f4a5a21f8db967f9c8ec4d2f03f0aa886b
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Thu Jun 17 07:33:30 2021 +0200

    vcc: Give the REGEX treatment to ACL expressions
    
    Except that we shouldn't start from expr0 since both use cases clearly
    need expr4 parsing. Instead of making assumptions based on the type in
    expr0, we split the final expression type check in its own function and
    use it to confirm that we are matching a regex or an acl.
    
    Fixes #3628

diff --git a/bin/varnishtest/tests/v00021.vtc b/bin/varnishtest/tests/v00021.vtc
index b8c2c4b40..d0a4f391f 100644
--- a/bin/varnishtest/tests/v00021.vtc
+++ b/bin/varnishtest/tests/v00021.vtc
@@ -151,6 +151,15 @@ varnish v1 -errvcl {Symbols named 'vcl_*' are reserved.} {
 	}
 }
 
+# 3628
+varnish v1 -vcl {
+	backend be none;
+	acl foo { }
+	sub vcl_recv {
+		if (client.ip ~ foo || server.ip ~ foo) { }
+	}
+}
+
 varnish v1 -errvcl {Expression has type BOOL, expected ACL} {
 	sub vcl_recv {
 		if (client.ip ~ true) { }
diff --git a/lib/libvcc/vcc_expr.c b/lib/libvcc/vcc_expr.c
index 4118d861b..329843bca 100644
--- a/lib/libvcc/vcc_expr.c
+++ b/lib/libvcc/vcc_expr.c
@@ -83,6 +83,8 @@ vcc_utype(vcc_type_t t)
 
 static void vcc_expr0(struct vcc *tl, struct expr **e, vcc_type_t fmt);
 static void vcc_expr_cor(struct vcc *tl, struct expr **e, vcc_type_t fmt);
+static void vcc_expr_typecheck(struct vcc *tl, struct expr **e, vcc_type_t fmt,
+    struct token *t1);
 
 static struct expr *
 vcc_new_expr(vcc_type_t fmt)
@@ -1107,12 +1109,16 @@ cmp_simple(struct vcc *tl, struct expr **e, const struct cmps *cp)
 static void v_matchproto_(cmp_f)
 cmp_regexp(struct vcc *tl, struct expr **e, const struct cmps *cp)
 {
+	struct token *t1;
 	struct expr *e2;
 	char buf[128];
 
 	*e = vcc_expr_edit(tl, STRING, "\vS", *e, NULL);
 	vcc_NextToken(tl);
-	vcc_expr0(tl, &e2, REGEX);
+	t1 = tl->t;
+	vcc_expr4(tl, &e2, REGEX);
+	ERRCHK(tl);
+	vcc_expr_typecheck(tl, &e2, REGEX, t1);
 	ERRCHK(tl);
 	bprintf(buf, "%sVRT_re_match(ctx, \v1, \v2)", cp->emit);
 	*e = vcc_expr_edit(tl, BOOL, buf, *e, e2);
@@ -1121,11 +1127,15 @@ cmp_regexp(struct vcc *tl, struct expr **e, const struct cmps *cp)
 static void v_matchproto_(cmp_f)
 cmp_acl(struct vcc *tl, struct expr **e, const struct cmps *cp)
 {
+	struct token *t1;
 	struct expr *e2;
 	char buf[256];
 
 	vcc_NextToken(tl);
-	vcc_expr0(tl, &e2, ACL);
+	t1 = tl->t;
+	vcc_expr4(tl, &e2, ACL);
+	ERRCHK(tl);
+	vcc_expr_typecheck(tl, &e2, ACL, t1);
 	ERRCHK(tl);
 	bprintf(buf, "%sVRT_acl_match(ctx, \v1, \v2)", cp->emit);
 	*e = vcc_expr_edit(tl, BOOL, buf, e2, *e);
@@ -1366,8 +1376,6 @@ vcc_expr0(struct vcc *tl, struct expr **e, vcc_type_t fmt)
 	t1 = tl->t;
 	if (fmt->stringform)
 		vcc_expr_cor(tl, e, STRINGS);
-	else if (fmt == REGEX)
-		vcc_expr4(tl, e, REGEX);
 	else
 		vcc_expr_cor(tl, e, fmt);
 	ERRCHK(tl);
@@ -1406,11 +1414,21 @@ vcc_expr0(struct vcc *tl, struct expr **e, vcc_type_t fmt)
 		ERRCHK(tl);
 	}
 
+	vcc_expr_typecheck(tl, e, fmt, t1);
+}
+
+static void
+vcc_expr_typecheck(struct vcc *tl, struct expr **e, vcc_type_t fmt,
+    struct token *t1)
+{
+
+	assert(fmt != VOID);
+	assert(fmt != STRINGS);
+
 	if (fmt != (*e)->fmt)  {
 		VSB_printf(tl->sb, "Expression has type %s, expected %s\n",
 		    vcc_utype((*e)->fmt), vcc_utype(fmt));
 		vcc_ErrWhere2(tl, t1, tl->t);
-		return;
 	}
 }