Add DEV_RANDOM pseudo-option and use it to "include out" random(4)

if desired.

Retire randomdev_none.c and introduce random_infra.c for resident
infrastructure. Completely stub out random(4) calls in the "without
DEV_RANDOM" case.

Add RANDOM_LOADABLE option to allow loadable Yarrow/Fortuna/LocallyWritten
algorithm.  Add a skeleton "other" algorithm framework for folks
to add their own processing code. NIST, anyone?

Retire the RANDOM_DUMMY option.

Build modules for Yarrow, Fortuna and "other".

Use atomics for the live entropy rate-tracking.

Convert ints to bools for the 'seeded' logic.

Move _write() function from the algorithm-specific areas to randomdev.c

Get rid of reseed() function - it is unused.

Tidy up the opt_*.h includes.

Update documentation for random(4) modules.

Fix test program (reviewers, please leave this).

Differential Revision:    https://reviews.freebsd.org/D3354
Reviewed by:              wblock,delphij,jmg,bjk
Approved by:              so (/dev/random blanket)

1 files changed, 128 insertions, 0 deletions

diff --git a/sys/dev/random/random_infra.c b/sys/dev/random/random_infra.c
new file mode 100644
index 0000000..d31b84b
--- /dev/null
+++ b/sys/dev/random/random_infra.c
@@ -0,0 +1,128 @@
+/*-
+ * Copyright (c) 2015 Mark R V Murray
+ * 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 AUTHOR ``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/kernel.h>
+#include <sys/malloc.h>
+#include <sys/random.h>
+#include <sys/sysctl.h>
+
+#if defined(RANDOM_LOADABLE)
+#include <sys/lock.h>
+#include <sys/sx.h>
+#endif
+
+#include <dev/random/randomdev.h>
+
+/* Set up the sysctl root node for the entropy device */
+SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 0, "Cryptographically Secure Random Number Generator");
+
+MALLOC_DEFINE(M_ENTROPY, "entropy", "Entropy harvesting buffers and data structures");
+
+struct sources_head source_list = LIST_HEAD_INITIALIZER(source_list);
+
+#if defined(RANDOM_LOADABLE)
+struct random_algorithm *p_random_alg_context = NULL;
+#else /* !defined(RANDOM_LOADABLE) */
+struct random_algorithm *p_random_alg_context = &random_alg_context;
+#endif /* defined(RANDOM_LOADABLE) */
+
+#if defined(RANDOM_LOADABLE)
+
+struct random_readers {
+	int	(*read_random_uio)(struct uio *, bool);
+	u_int	(*read_random)(void *, u_int);
+} random_reader_context = {
+	(int (*)(struct uio *, bool))nullop,
+	(u_int (*)(void *, u_int))nullop,
+};
+
+struct sx randomdev_config_lock;
+
+static void
+random_infra_sysinit(void *dummy __unused)
+{
+
+	RANDOM_CONFIG_INIT_LOCK();
+}
+SYSINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_FIRST, random_infra_sysinit, NULL);
+
+void
+random_infra_init(int (*p_random_read_uio)(struct uio *, bool), u_int (*p_random_read)(void *, u_int))
+{
+
+	RANDOM_CONFIG_X_LOCK();
+	random_reader_context.read_random_uio = p_random_read_uio;
+	random_reader_context.read_random = p_random_read;
+	RANDOM_CONFIG_X_UNLOCK();
+}
+
+void
+random_infra_uninit(void)
+{
+
+	RANDOM_CONFIG_X_LOCK();
+	random_reader_context.read_random_uio = (int (*)(struct uio *, bool))nullop;
+	random_reader_context.read_random = (u_int (*)(void *, u_int))nullop;
+	RANDOM_CONFIG_X_UNLOCK();
+}
+
+static void
+random_infra_sysuninit(void *dummy __unused)
+{
+
+	RANDOM_CONFIG_DEINIT_LOCK();
+}
+SYSUNINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_FIRST, random_infra_sysuninit, NULL);
+
+int
+read_random_uio(struct uio *uio, bool nonblock)
+{
+	int retval;
+
+	RANDOM_CONFIG_S_LOCK();
+	retval = random_reader_context.read_random_uio(uio, nonblock);
+	RANDOM_CONFIG_S_UNLOCK();
+	return (retval);
+}
+
+u_int
+read_random(void *buf, u_int len)
+{
+	u_int retval;
+
+	RANDOM_CONFIG_S_LOCK();
+	retval = random_reader_context.read_random(buf, len);
+	RANDOM_CONFIG_S_UNLOCK();
+	return (retval);
+}
+
+#endif /* defined(RANDOM_LOADABLE) */