This implements a hardware random number generator for UML which attaches
itself to the host's /dev/random.
Signed-off-by: Jeff Dike <[EMAIL PROTECTED]>
Index: linux-2.6.11/arch/um/Kconfig_char
===================================================================
--- linux-2.6.11.orig/arch/um/Kconfig_char 2005-03-08 20:13:55.000000000
-0500
+++ linux-2.6.11/arch/um/Kconfig_char 2005-03-08 20:22:24.000000000 -0500
@@ -190,5 +190,19 @@
tristate
default UML_SOUND
+config UML_RANDOM
+ tristate "Hardware random number generator"
+ help
+ This option enables UML's "hardware" random number generator. It
+ attaches itself to the host's /dev/random, supplying as much entropy
+ as the host has, rather than the small amount the UML gets from its
+ own drivers. It registers itself as a standard hardware random number
+ generator, major 10, minor 183, and the canonical device name is
+ /dev/hwrng.
+ The way to make use of this is to install the rng-tools package
+ (check your distro, or download from
+ http://sourceforge.net/projects/gkernel/). rngd periodically reads
+ /dev/hwrng and injects the entropy into /dev/random.
+
endmenu
Index: linux-2.6.11/arch/um/defconfig
===================================================================
--- linux-2.6.11.orig/arch/um/defconfig 2005-03-08 20:13:55.000000000 -0500
+++ linux-2.6.11/arch/um/defconfig 2005-03-08 20:22:24.000000000 -0500
@@ -111,6 +111,7 @@
CONFIG_UML_SOUND=m
CONFIG_SOUND=m
CONFIG_HOSTAUDIO=m
+CONFIG_UML_RANDOM=y
#
# Block devices
Index: linux-2.6.11/arch/um/drivers/Makefile
===================================================================
--- linux-2.6.11.orig/arch/um/drivers/Makefile 2005-03-08 20:17:34.000000000
-0500
+++ linux-2.6.11/arch/um/drivers/Makefile 2005-03-08 20:22:24.000000000
-0500
@@ -3,7 +3,7 @@
# Licensed under the GPL
#
-CHAN_OBJS := chan_kern.o chan_user.o line.o
+CHAN_OBJS := chan_kern.o chan_user.o line.o
# pcap is broken in 2.5 because kbuild doesn't allow pcap.a to be linked
# in to pcap.o
@@ -41,7 +41,7 @@
obj-$(CONFIG_XTERM_CHAN) += xterm.o xterm_kern.o
obj-$(CONFIG_UML_WATCHDOG) += harddog.o
obj-$(CONFIG_BLK_DEV_COW_COMMON) += cow_user.o
-
+obj-$(CONFIG_UML_RANDOM) += random.o
USER_SINGLE_OBJS = $(foreach f,$(patsubst %.o,%,$(obj-y)
$(obj-m)),$($(f)-objs))
Index: linux-2.6.11/arch/um/drivers/random.c
===================================================================
--- linux-2.6.11.orig/arch/um/drivers/random.c 2003-09-15 09:40:47.000000000
-0400
+++ linux-2.6.11/arch/um/drivers/random.c 2005-03-08 20:22:24.000000000
-0500
@@ -0,0 +1,122 @@
+/* Much of this ripped from hw_random.c */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/delay.h>
+#include <asm/uaccess.h>
+#include "os.h"
+
+/*
+ * core module and version information
+ */
+#define RNG_VERSION "1.0.0"
+#define RNG_MODULE_NAME "random"
+#define RNG_DRIVER_NAME RNG_MODULE_NAME " virtual driver " RNG_VERSION
+#define PFX RNG_MODULE_NAME ": "
+
+#define RNG_MISCDEV_MINOR 183 /* official */
+
+static int random_fd = -1;
+
+static int rng_dev_open (struct inode *inode, struct file *filp)
+{
+ /* enforce read-only access to this chrdev */
+ if ((filp->f_mode & FMODE_READ) == 0)
+ return -EINVAL;
+ if (filp->f_mode & FMODE_WRITE)
+ return -EINVAL;
+
+ return 0;
+}
+
+static ssize_t rng_dev_read (struct file *filp, char __user *buf, size_t size,
+ loff_t * offp)
+{
+ u32 data;
+ int n, ret = 0, have_data;
+
+ while(size){
+ n = os_read_file(random_fd, &data, sizeof(data));
+ if(n > 0){
+ have_data = n;
+ while (have_data && size) {
+ if (put_user((u8)data, buf++)) {
+ ret = ret ? : -EFAULT;
+ break;
+ }
+ size--;
+ ret++;
+ have_data--;
+ data>>=8;
+ }
+ }
+ else if(n == -EAGAIN){
+ if (filp->f_flags & O_NONBLOCK)
+ return ret ? : -EAGAIN;
+
+ if(need_resched()){
+ current->state = TASK_INTERRUPTIBLE;
+ schedule_timeout(1);
+ }
+ }
+ else return n;
+ if (signal_pending (current))
+ return ret ? : -ERESTARTSYS;
+ }
+ return ret;
+}
+
+static struct file_operations rng_chrdev_ops = {
+ .owner = THIS_MODULE,
+ .open = rng_dev_open,
+ .read = rng_dev_read,
+};
+
+static struct miscdevice rng_miscdev = {
+ RNG_MISCDEV_MINOR,
+ RNG_MODULE_NAME,
+ &rng_chrdev_ops,
+};
+
+/*
+ * rng_init - initialize RNG module
+ */
+static int __init rng_init (void)
+{
+ int err;
+
+ err = os_open_file("/dev/random", of_read(OPENFLAGS()), 0);
+ if(err < 0)
+ goto out;
+
+ random_fd = err;
+
+ err = os_set_fd_block(random_fd, 0);
+ if(err)
+ goto err_out_cleanup_hw;
+
+ err = misc_register (&rng_miscdev);
+ if (err) {
+ printk (KERN_ERR PFX "misc device register failed\n");
+ goto err_out_cleanup_hw;
+ }
+
+ out:
+ return err;
+
+ err_out_cleanup_hw:
+ random_fd = -1;
+ goto out;
+}
+
+/*
+ * rng_cleanup - shutdown RNG module
+ */
+static void __exit rng_cleanup (void)
+{
+ misc_deregister (&rng_miscdev);
+}
+
+module_init (rng_init);
+module_exit (rng_cleanup);
-
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