_gnutls_set_[str]datum: Cleanup, add function attributes

_gnutls_set_datum(): Do not change output 'dat' on error
_gnutls_set_strdatum: Likewise, cleanup code

Signed-off-by: Tim Rühsen <tim.ruehsen@gmx.de>

2 files changed, 19 insertions, 21 deletions

diff --git a/lib/datum.c b/lib/datum.c
index ff71068b99..bd0f216438 100644
--- a/lib/datum.c
+++ b/lib/datum.c
@@ -30,6 +30,7 @@
 #include <datum.h>
 #include "errors.h"
 
+/* On error, @dat is not changed. */
 int
 _gnutls_set_datum(gnutls_datum_t * dat, const void *data, size_t data_size)
 {
@@ -39,10 +40,11 @@ _gnutls_set_datum(gnutls_datum_t * dat, const void *data, size_t data_size)
 		return 0;
 	}
 
-	dat->data = gnutls_malloc(data_size);
-	if (dat->data == NULL)
+	unsigned char *m = gnutls_malloc(data_size);
+	if (!m)
 		return GNUTLS_E_MEMORY_ERROR;
 
+	dat->data = m;
 	dat->size = data_size;
 	memcpy(dat->data, data, data_size);
 
@@ -51,22 +53,22 @@ _gnutls_set_datum(gnutls_datum_t * dat, const void *data, size_t data_size)
 
 /* ensures that the data set are null-terminated
  * The function always returns an allocated string in @dat on success.
+ * On error, @dat is not changed.
  */
 int
 _gnutls_set_strdatum(gnutls_datum_t * dat, const void *data, size_t data_size)
 {
-	if (data_size == 0 || data == NULL) {
-		dat->data = gnutls_calloc(1, 1);
-		dat->size = 0;
-		return 0;
-	}
+	if (data == NULL)
+		return gnutls_assert_val(GNUTLS_E_ILLEGAL_PARAMETER);
 
-	dat->data = gnutls_malloc(data_size+1);
-	if (dat->data == NULL)
+	unsigned char *m = gnutls_malloc(data_size + 1);
+	if (!m)
 		return GNUTLS_E_MEMORY_ERROR;
 
+	dat->data = m;
 	dat->size = data_size;
-	memcpy(dat->data, data, data_size);
+	if (data_size)
+		memcpy(dat->data, data, data_size);
 	dat->data[data_size] = 0;
 
 	return 0;
diff --git a/lib/datum.h b/lib/datum.h
index cdab4b272d..fe847359b0 100644
--- a/lib/datum.h
+++ b/lib/datum.h
@@ -28,11 +28,13 @@
 /* This will copy the provided data in @dat. If the provided data are
  * NULL or zero-size @dat will be NULL as well.
  */
+warn_unused_result nonnull((1))
 int _gnutls_set_datum(gnutls_datum_t * dat, const void *data,
 		      size_t data_size);
 
 /* This will always return a non-NULL, and zero-terminated string in @dat.
  */
+warn_unused_result nonnull((1))
 int _gnutls_set_strdatum(gnutls_datum_t * dat, const void *data,
 			 size_t data_size);
 
@@ -40,17 +42,13 @@ int _gnutls_set_strdatum(gnutls_datum_t * dat, const void *data,
 inline static
 void _gnutls_free_datum(gnutls_datum_t * dat)
 {
-	if (dat == NULL)
-		return;
-
-	if (dat->data != NULL)
+	if (dat != NULL) {
 		gnutls_free(dat->data);
-
-	dat->data = NULL;
-	dat->size = 0;
+		dat->size = 0;
+	}
 }
 
-inline static
+inline static nonnull_all
 void _gnutls_free_temp_key_datum(gnutls_datum_t * dat)
 {
 	if (dat->data != NULL) {
@@ -58,11 +56,10 @@ void _gnutls_free_temp_key_datum(gnutls_datum_t * dat)
 		gnutls_free(dat->data);
 	}
 
-	dat->data = NULL;
 	dat->size = 0;
 }
 
-inline static
+inline static nonnull_all
 void _gnutls_free_key_datum(gnutls_datum_t * dat)
 {
 	if (dat->data != NULL) {
@@ -70,7 +67,6 @@ void _gnutls_free_key_datum(gnutls_datum_t * dat)
 		gnutls_free(dat->data);
 	}
 
-	dat->data = NULL;
 	dat->size = 0;
 }