1 files changed, 80 insertions, 0 deletions
diff --git a/usr/src/uts/common/syscall/getrandom.c b/usr/src/uts/common/syscall/getrandom.c
new file mode 100644
index 0000000000..46b650b0dc
--- /dev/null
+++ b/usr/src/uts/common/syscall/getrandom.c
@@ -0,0 +1,80 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright (c) 2015, Joyent, Inc.
+ */
+
+/*
+ * getrandom system call implementation
+ */
+
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/systm.h>
+#include <sys/random.h>
+#include <sys/ddi.h>
+#include <sys/sunddi.h>
+#include <sys/sysmacros.h>
+
+#include <sys/random.h>
+
+/*
+ * Impose a maximum upper bound on the number of bytes that we'll read in one
+ * go, ala a read of /dev/random. For /dev/urandom, we clamp it based on our
+ * return value, because the system call returns an int, we can't handle more
+ * than INT_MAX.
+ */
+#define	MAXRANDBYTES	1024
+#define	MAXURANDBYTES	INT_MAX
+
+int
+getrandom(void *bufp, size_t buflen, int flags)
+{
+	int out = 0;
+	uint8_t rbytes[128];
+	uint8_t *buf = bufp;
+
+	if (flags & ~(GRND_NONBLOCK | GRND_RANDOM))
+		return (set_errno(EINVAL));
+
+	if ((flags & GRND_RANDOM) && buflen > MAXRANDBYTES) {
+		buflen = MAXRANDBYTES;
+	} else if (buflen > MAXURANDBYTES) {
+		buflen = MAXURANDBYTES;
+	}
+
+	while (buflen > out) {
+		int err;
+		size_t len = MIN(sizeof (rbytes), buflen);
+
+		if (flags & GRND_RANDOM) {
+			if (flags & GRND_NONBLOCK)
+				err = random_get_bytes(rbytes, len);
+			else
+				err = random_get_blocking_bytes(rbytes, len);
+		} else {
+			err = random_get_pseudo_bytes(rbytes, len);
+		}
+
+		if (err == 0) {
+			if (ddi_copyout(rbytes, buf + out, len, 0) != 0)
+				return (set_errno(EFAULT));
+			out += len;
+		} else if (err == EAGAIN && out > 0) {
+			break;
+		} else {
+			return (set_errno(err));
+		}
+	}
+
+	return (out);
+}