From: Alan T. DeKok <aland@freeradius.org>
Date: Sun, 1 Oct 2023 12:54:20 +0000 (-0400)
Subject: allow expressions in %{...} xlats
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aa81ffb3851012490a62e8797f16cd526e0ec963;p=thirdparty%2Ffreeradius-server.git

allow expressions in %{...} xlats
---

diff --git a/src/lib/unlang/xlat_eval.c b/src/lib/unlang/xlat_eval.c
index fc138c698c6..e2edaf0dabf 100644
--- a/src/lib/unlang/xlat_eval.c
+++ b/src/lib/unlang/xlat_eval.c
@@ -1197,7 +1197,7 @@ xlat_action_t xlat_frame_eval(TALLOC_CTX *ctx, fr_dcursor_t *out, xlat_exp_head_
 
 				if (tmpl_eval_pair(ctx, &result, request, node->vpt) < 0) goto fail;
 
-			} else if (tmpl_is_exec(node->vpt)) { /* exec only */
+			} else if (tmpl_is_exec(node->vpt) || tmpl_is_xlat(node->vpt)) {
 				xlat_exec_rctx_t *rctx;
 
 				/*
diff --git a/src/lib/unlang/xlat_tokenize.c b/src/lib/unlang/xlat_tokenize.c
index d3b92f00455..99633070714 100644
--- a/src/lib/unlang/xlat_tokenize.c
+++ b/src/lib/unlang/xlat_tokenize.c
@@ -906,6 +906,13 @@ done:
 	return 0;
 }
 
+static bool const tmpl_attr_allowed_chars[UINT8_MAX + 1] = {
+	SBUFF_CHAR_CLASS_ALPHA_NUM,
+	['-'] = true, ['/'] = true, ['_'] = true,			// fr_dict_attr_allowed_chars
+	['.'] = true, ['*'] = true, ['#'] = true,
+	['['] = true, [']'] = true, 					// tmpls and attribute arrays
+};
+
 int xlat_tokenize_expansion(xlat_exp_head_t *head, fr_sbuff_t *in,
 			    tmpl_rules_t const *t_rules)
 {
@@ -962,6 +969,71 @@ int xlat_tokenize_expansion(xlat_exp_head_t *head, fr_sbuff_t *in,
 	}
 #endif /* HAVE_REGEX */
 
+	/*
+	 *	See if it's an old-style function name.
+	 */
+	fr_sbuff_marker(&s_m, in);
+	len = fr_sbuff_adv_past_allowed(in, SIZE_MAX, xlat_func_chars, NULL);
+	if (fr_sbuff_is_char(in, ':')) {
+		if (!len) goto missing_function;
+		goto check_for_attr;
+	}
+
+	/*
+	 *	See if it's an attribute reference, with possible array stuff.
+	 */
+	len += fr_sbuff_adv_past_allowed(in, SIZE_MAX, tmpl_attr_allowed_chars, NULL);
+	if (fr_sbuff_is_char(in, '}')) {
+		if (!len) goto empty_disallowed;
+		goto check_for_attr;
+	}
+
+	if (!fr_sbuff_extend(in)) {
+		fr_strerror_const("Missing closing brace");
+		fr_sbuff_marker_release(&s_m);
+		return -1;
+	}
+
+	/*
+	 *	It must be an expression.
+	 *
+	 *	We wrap the xlat in a tmpl, so that the result is just a value, and not wrapped in another
+	 *	XLAT_GROUP, which turns into a wrapper of FR_TYPE_GROUP in the value-box.
+	 */
+	{
+		int ret;
+		char *fmt;
+		xlat_exp_t *node;
+		xlat_exp_head_t *child;
+
+		fr_sbuff_set(in, &s_m);		/* backtrack to the start of the expression */
+
+		MEM(node = xlat_exp_alloc(head, XLAT_TMPL, NULL, 0));
+		MEM(node->vpt = tmpl_alloc(node, TMPL_TYPE_XLAT, T_BARE_WORD, "", 1));
+
+		ret = xlat_tokenize_expression(node->vpt, &child, in, &attr_p_rules, t_rules);
+		if (ret <= 0) {
+			talloc_free(node);
+			return ret;
+		}
+
+		if (!fr_sbuff_next_if_char(in, '}')) {
+			fr_strerror_const("Missing closing brace");
+			return -1;
+		}
+
+		MEM(fmt = talloc_bstrndup(node, fr_sbuff_current(&s_m), fr_sbuff_behind(&s_m)));
+		xlat_exp_set_name_buffer_shallow(node, fmt);
+		tmpl_set_name_shallow(node->vpt, T_BARE_WORD, fmt, fr_sbuff_behind(&s_m));
+
+		tmpl_set_xlat(node->vpt, child);
+		xlat_exp_insert_tail(head, node);
+		return ret;
+	}
+
+check_for_attr:
+	fr_sbuff_set(in, &s_m);		/* backtrack */
+
 	/*
 	 *	%{Attr-Name}
 	 *	%{Attr-Name[#]}
@@ -993,10 +1065,12 @@ int xlat_tokenize_expansion(xlat_exp_head_t *head, fr_sbuff_t *in,
 	if (len == 0) {
 		switch (hint) {
 		case '}':
+		empty_disallowed:
 			fr_strerror_const("Empty expression is invalid");
 			return -1;
 
 		case ':':
+		missing_function:
 			fr_strerror_const("Missing expansion function");
 			return -1;
 
diff --git a/src/tests/keywords/expand-expr b/src/tests/keywords/expand-expr
new file mode 100644
index 00000000000..6f4d2f36e1b
--- /dev/null
+++ b/src/tests/keywords/expand-expr
@@ -0,0 +1,20 @@
+uint32 foo
+uint32 bar
+uint32 baz
+uint32 none
+
+&foo = 1
+&bar = 2
+
+&baz := %{&foo + &bar}
+
+if !(&baz == 3) {
+	test_fail
+}
+
+&baz := %{&none || &foo}
+if !(&baz == &foo) {
+	test_fail
+}
+
+success
diff --git a/src/tests/unit/xlat/base.txt b/src/tests/unit/xlat/base.txt
index 63706b75d66..4bbe2bc0d7b 100644
--- a/src/tests/unit/xlat/base.txt
+++ b/src/tests/unit/xlat/base.txt
@@ -237,19 +237,19 @@ xlat %{[baz}
 match ERROR offset 3: Missing attribute name
 
 xlat %{ }
-match ERROR offset 3: Invalid char ' ' in expression
+match ERROR offset 4: No operand found.  Expected &ref, literal, 'quoted literal', "%{expansion}", or enum value
 
 xlat %{\t}
-match ERROR offset 3: Invalid attribute name
+match ERROR offset 3: No operand found.  Expected &ref, literal, 'quoted literal', "%{expansion}", or enum value
 
 xlat %{\n}
-match ERROR offset 3: Invalid attribute name
+match ERROR offset 3: No operand found.  Expected &ref, literal, 'quoted literal', "%{expansion}", or enum value
 
 xlat %{foo }
-match ERROR offset 6: Invalid char ' ' in expression
+match ERROR offset 7: Unexpected text - attribute names must prefixed with '&'
 
 xlat %{foo bar}
-match ERROR offset 6: Invalid char ' ' in expression
+match ERROR offset 7: Invalid operator
 
 xlat %{test:
 match ERROR offset 8: Missing closing brace
@@ -294,8 +294,12 @@ xlat_argv /bin/sh "foo bar" "%{User-Name} %{Filter-Id}"
 match [0]{ /bin/sh }, [1]{ foo bar }, [2]{ %{User-Name} %{Filter-Id} }
 
 # and errors
+#
+#  @todo - we should really be unescaping the input in the sbuff, OR passing in the terminals
+#  to xlat_tokenize_expansion()
+#
 xlat_argv /bin/sh "foo bar" "%{User-Name} %{Filter-Id"
-match ERROR offset 45: Missing closing brace
+match ERROR offset 44: Unexpected text after enum value.  Expected operator
 
 # and text immediately after a variable expansion
 xlat_argv echo hello %{Tmp-String-0}:1234 world