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authorFlorian Weimer <fweimer@redhat.com>2017-06-21 22:43:57 +0200
committerFlorian Weimer <fweimer@redhat.com>2017-06-21 22:43:57 +0200
commit4dd8e7c0ce5ecc7f65e33e60ad2f717b31de32ec (patch)
treebfc9688f34dfc949e8da77d0ec05b684ff64e86f /malloc/alloc_buffer_copy_bytes.c
parent11ffcacb64a939c10cfc713746b8ec88837f5c4a (diff)
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Implement allocation buffers for internal use
This commit adds fixed-size allocation buffers.  The primary use
case is in NSS modules, where dynamically sized data is stored
in a fixed-size buffer provided by the caller.

Other uses include a replacement of mempcpy cascades (which is
safer due to the size checking inherent to allocation buffers).
Diffstat (limited to 'malloc/alloc_buffer_copy_bytes.c')
-rw-r--r--malloc/alloc_buffer_copy_bytes.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/malloc/alloc_buffer_copy_bytes.c b/malloc/alloc_buffer_copy_bytes.c
new file mode 100644
index 0000000000..66196f1520
--- /dev/null
+++ b/malloc/alloc_buffer_copy_bytes.c
@@ -0,0 +1,34 @@
+/* Copy an array of bytes into the buffer.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <alloc_buffer.h>
+
+#include <string.h>
+
+/* This function works on a copy of the buffer object, so that it can
+   remain non-addressable in the caller.  */
+struct alloc_buffer
+__libc_alloc_buffer_copy_bytes (struct alloc_buffer buf,
+                                const void *src, size_t len)
+{
+  void *ptr = alloc_buffer_alloc_bytes (&buf, len);
+  if (ptr != NULL)
+    memcpy (ptr, src, len);
+  return buf;
+}
+libc_hidden_def (__libc_alloc_buffer_copy_bytes)