From: James Jones <jejones3141@gmail.com>
Date: Thu, 14 May 2020 18:25:40 +0000 (-0500)
Subject: Correct FR_DBUF_MAX macro and add tests for it. (#3452)
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eb76269352d8a2684c57fe83d367f07d71950b42;p=thirdparty%2Ffreeradius-server.git

Correct FR_DBUF_MAX macro and add tests for it. (#3452)
---

diff --git a/src/lib/util/dbuff.h b/src/lib/util/dbuff.h
index 2ceeb5f22c3..46cbaa65dc6 100644
--- a/src/lib/util/dbuff.h
+++ b/src/lib/util/dbuff.h
@@ -111,8 +111,8 @@ struct fr_dbuff_s {
  * @param[in] _dbuff	to reserve bytes in.
  * @param[in] _max	The maximum number of bytes the caller is allowed to write to.
  */
-#define FR_DBUFF_MAX(_dbuff,  _max) (fr_dbuff_remaining(_dbuff) > (_max)) ? \
-	FR_DBUFF_RESERVE(_dbuff, fr_dbuff_remaining(_dbuff) - (_max)) : \
+#define FR_DBUFF_MAX(_dbuff,  _max) ((fr_dbuff_remaining(_dbuff) > (_max)) ? \
+	&FR_DBUFF_RESERVE(_dbuff, fr_dbuff_remaining(_dbuff) - (_max)) : \
 	_dbuff)
 
 /** Does the actual work of initialising a dbuff
diff --git a/src/lib/util/dbuff_tests.c b/src/lib/util/dbuff_tests.c
index 5450dd2cdd7..55a02a9a7fa 100644
--- a/src/lib/util/dbuff_tests.c
+++ b/src/lib/util/dbuff_tests.c
@@ -42,6 +42,23 @@ static void test_dbuff_init_no_parent(void)
 	TEST_CHECK(dbuff.parent == NULL);
 }
 
+static void test_dbuff_max(void)
+{
+	uint8_t const	in[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 };
+	fr_dbuff_t	dbuff;
+	fr_dbuff_t	*max_dbuff;
+
+	TEST_CASE("Confirm max constrains available space");
+	fr_dbuff_init(&dbuff, in, sizeof(in));
+
+	max_dbuff = FR_DBUFF_MAX(&dbuff, 4);
+	TEST_CHECK(fr_dbuff_remaining(max_dbuff) == 4);
+
+	max_dbuff = FR_DBUFF_MAX(&dbuff, 2 * sizeof(in));
+	TEST_CHECK(fr_dbuff_remaining(max_dbuff) == sizeof(in));
+}
+
+
 /** Test the various dbuff_net_encode() functions and macros
  *
  * @note Passing constants to fr_dbuff_in() as it is written results in
@@ -209,6 +226,7 @@ TEST_LIST = {
 	 */
 	{ "fr_dbuff_init",				test_dbuff_init },
 	{ "fr_dbuff_init_no_parent",			test_dbuff_init_no_parent },
+	{ "fr_dbuff_max",				test_dbuff_max },
 	{ "fr_dbuff_in",			test_dbuff_net_encode },
 
 	{ NULL }