svn commit: r280955 - in head/sys: modules/notrandom dev/notrandom

[Mateusz Guzik]

Author: mjg
Date: Wed Apr  1 13:37:00 2015
New Revision: 280955
URL: https://svnweb.freebsd.org/changeset/base/280955

Log:
  Add /dev/notrandom

  notrandom provides fast and reliable not random numbers.

  This was added in an effort to increase feature-compatiblity with
  Solaris 10.

  See http://www.brendangregg.com/Specials/notrandom.c for Solaris
  implementation.

  Reviewed-by: Bruce Schneier (ok, not really)
  MFC after:	1 week

Added:
  head/sys/modules/notrandom/Makefile
  head/sys/dev/notrandom/notrandom.c

Added: sys/dev/notrandom/notrandom.c
===================================================================
--- head/sys/dev/notrandom/notrandom.c	(revision 0)
+++ head/sys/dev/notrandom/notrandom.c	(working copy)
@@ -0,0 +1,126 @@
+/*-
+ * Copyright (c) 2015 Mateusz Guzik
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer
+ *    in this position and unchanged.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/conf.h>
+#include <sys/uio.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/filio.h>
+
+static struct cdev *notrandom_dev;
+
+static d_ioctl_t notrandom_ioctl;
+static d_read_t notrandom_read;
+
+static struct cdevsw notrandom_cdevsw = {
+	.d_version =	D_VERSION,
+	.d_read =	notrandom_read,
+	.d_ioctl =	notrandom_ioctl,
+	.d_name =	"notrandom",
+	.d_flags =	D_MMAP_ANON,
+};
+
+static char notrandom_buf[1024];
+
+static int
+notrandom_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data __unused,
+	   int flags __unused, struct thread *td)
+{
+	int error = 0;
+
+	switch (cmd) {
+	case FIONBIO:
+		break;
+	case FIOASYNC:
+		if (*(int *)data != 0)
+			error = EINVAL;
+		break;
+	default:
+		error = ENOIOCTL;
+	}
+	return (error);
+}
+
+
+/* ARGSUSED */
+static int
+notrandom_read(struct cdev *dev __unused, struct uio *uio, int flags __unused)
+{
+	ssize_t len;
+	int error = 0;
+
+	while (uio->uio_resid > 0 && error == 0) {
+		len = uio->uio_resid;
+		if (len > sizeof(notrandom_buf))
+			len = sizeof(notrandom_buf);
+		error = uiomove(notrandom_buf, len, uio);
+	}
+
+	return (error);
+}
+
+/* ARGSUSED */
+static int
+notrandom_modevent(module_t mod __unused, int type, void *data __unused)
+{
+	int error = 0;
+
+	switch(type) {
+	case MOD_LOAD:
+		memset(notrandom_buf, 7, sizeof(notrandom_buf));
+		notrandom_dev = make_dev_credf(MAKEDEV_ETERNAL_KLD,
+		    &notrandom_cdevsw, 0, NULL, UID_ROOT, GID_WHEEL, 0666,
+		    "notrandom");
+		break;
+
+	case MOD_UNLOAD:
+		destroy_dev(notrandom_dev);
+		/*
+		 * Trash notrandom region so that the content cannot be
+		 * retrieved. Better safe than sorry.
+		 */
+		memset(notrandom_buf, 123, sizeof(notrandom_buf));
+		break;
+
+	case MOD_SHUTDOWN:
+		break;
+
+	default:
+		error = EOPNOTSUPP;
+	}
+
+	return (error);
+}
+
+DEV_MODULE(notrandom, notrandom_modevent, NULL);
+MODULE_VERSION(notrandom, 1);

Property changes on: head/sys/dev/notrandom/notrandom.c
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Added: svn:eol-style
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+native
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+FreeBSD=%H
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+text/plain
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Added: sys/modules/notrandom/Makefile
===================================================================
--- head/sys/modules/notrandom/Makefile	(revision 0)
+++ head/sys/modules/notrandom/Makefile	(working copy)
@@ -0,0 +1,8 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../dev/notrandom
+
+KMOD=	notrandom
+SRCS=	notrandom.c
+
+.include <bsd.kmod.mk>

Property changes on: head/sys/modules/notrandom/Makefile
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Added: svn:eol-style
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+native
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+FreeBSD=%H
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