From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Thu, 6 Oct 2022 23:11:46 +0000 (+0200)
Subject: lib: buffer - Add buffer_clear_safe().
X-Git-Tag: 2.4.0~3152
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ffb404856438bf2d9a626ccd10d74d76c20bb504;p=thirdparty%2Fdovecot%2Fcore.git

lib: buffer - Add buffer_clear_safe().
---

diff --git a/src/lib/buffer.c b/src/lib/buffer.c
index 64255b5027..91123de15b 100644
--- a/src/lib/buffer.c
+++ b/src/lib/buffer.c
@@ -3,6 +3,7 @@
 /* @UNSAFE: whole file */
 
 #include "lib.h"
+#include "safe-memset.h"
 #include "buffer.h"
 
 struct real_buffer {
@@ -413,6 +414,14 @@ void buffer_set_used_size(buffer_t *_buf, size_t used_size)
 	buf->used = used_size;
 }
 
+void buffer_clear_safe(buffer_t *_buf)
+{
+	struct real_buffer *buf = container_of(_buf, struct real_buffer, buf);
+
+	safe_memset(buf->w_buffer, 0, I_MAX(buf->used, buf->dirty));
+	buffer_clear(_buf);
+}
+
 size_t buffer_get_size(const buffer_t *_buf)
 {
 	const struct real_buffer *buf =
diff --git a/src/lib/buffer.h b/src/lib/buffer.h
index f6c26df93a..69b3a1319c 100644
--- a/src/lib/buffer.h
+++ b/src/lib/buffer.h
@@ -116,6 +116,8 @@ static inline void buffer_clear(buffer_t *buf)
 {
 	buffer_set_used_size(buf, 0);
 }
+/* Clear the buffer, but also make sure any contents is zeroed out. */
+void buffer_clear_safe(buffer_t *_buf);
 
 /* Returns the current buffer size. */
 size_t buffer_get_size(const buffer_t *buf) ATTR_PURE;