[PATCH] Add getrandom syscall wrapper function

[Hauke Mehrtens <hauke@hauke-m.de>]

This syscall is available since Linux 3.17 and was also implemented in
glibc in version 2.25. This is a pure syscall wrapper liker glibc does
it.
---
 include/sys/random.h  | 19 +++++++++++++++++++
 src/linux/getrandom.c | 11 +++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 include/sys/random.h
 create mode 100644 src/linux/getrandom.c

diff --git a/include/sys/random.h b/include/sys/random.h
new file mode 100644
index 00000000..5540f877
--- /dev/null
+++ b/include/sys/random.h
@@ -0,0 +1,19 @@
+#ifndef _SYS_RANDOM_H
+#define _SYS_RANDOM_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define __NEED_size_t
+#define __NEED_ssize_t
+#include <bits/alltypes.h>
+
+#define GRND_NONBLOCK	0x0001
+#define GRND_RANDOM	0x0002
+
+ssize_t getrandom(void *buf, size_t buflen, unsigned int flags);
+
+#ifdef __cplusplus
+}
+#endif
+#endif
diff --git a/src/linux/getrandom.c b/src/linux/getrandom.c
new file mode 100644
index 00000000..50b07df9
--- /dev/null
+++ b/src/linux/getrandom.c
@@ -0,0 +1,11 @@
+#include <sys/random.h>
+#include "syscall.h"
+
+ssize_t getrandom(void *buf, size_t buflen, unsigned int flags)
+{
+#ifdef SYS_getrandom
+	return syscall_cp(SYS_getrandom, buf, buflen, flags);
+#else
+	return __syscall_ret(-ENOSYS);
+#endif
+}
-- 
2.11.0