add renameat2 linux syscall wrapper

This syscall is available since Linux 3.15 and also implemented in
glibc from version 2.28. It is commonly used in filesystem or security
contexts.

Constants RENAME_NOREPLACE, RENAME_EXCHANGE, RENAME_WHITEOUT are
guarded by _GNU_SOURCE as with glibc.

2 files changed, 18 insertions, 0 deletions

diff --git a/include/stdio.h b/include/stdio.h
index cb85861..4ea4c17 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -158,6 +158,13 @@ char *ctermid(char *);
 #define L_ctermid 20
 #endif
 
+#if defined(_GNU_SOURCE)
+#define RENAME_NOREPLACE (1 << 0)
+#define RENAME_EXCHANGE  (1 << 1)
+#define RENAME_WHITEOUT  (1 << 2)
+
+int renameat2(int, const char *, int, const char *, unsigned);
+#endif
 
 #if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
  || defined(_BSD_SOURCE)
diff --git a/src/linux/renameat2.c b/src/linux/renameat2.c
new file mode 100644
index 0000000..b806038
--- /dev/null
+++ b/src/linux/renameat2.c
@@ -0,0 +1,11 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include "syscall.h"
+
+int renameat2(int oldfd, const char *old, int newfd, const char *new, unsigned flags)
+{
+#ifdef SYS_renameat
+	if (!flags) return syscall(SYS_renameat, oldfd, old, newfd, new);
+#endif
+	return syscall(SYS_renameat2, oldfd, old, newfd, new, flags);
+}