--- /dev/null
+/*
+ * A system independant way of adding entropy to the kernels pool
+ * this way the drivers can focus on the real work and we can take
+ * care of pushing it to the appropriate place in the kernel.
+ *
+ * This should be fast and callable from timers/interrupts
+ *
+ * Written by David McCullough <david_mccullough@mcafee.com>
+ * Copyright (C) 2006-2010 David McCullough
+ * Copyright (C) 2004-2005 Intel Corporation.
+ *
+ * LICENSE TERMS
+ *
+ * The free distribution and use of this software in both source and binary
+ * form is allowed (with or without changes) provided that:
+ *
+ * 1. distributions of this source code include the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ *
+ * 2. distributions in binary form include the above copyright
+ * notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other associated materials;
+ *
+ * 3. the copyright holder's name is not used to endorse products
+ * built using this software without specific written permission.
+ *
+ * ALTERNATIVELY, provided that this notice is retained in full, this product
+ * may be distributed under the terms of the GNU General Public License (GPL),
+ * in which case the provisions of the GPL apply INSTEAD OF those given above.
+ *
+ * DISCLAIMER
+ *
+ * This software is provided 'as is' with no explicit or implied warranties
+ * in respect of its properties, including, but not limited to, correctness
+ * and/or fitness for purpose.
+ */
+
+#ifndef AUTOCONF_INCLUDED
+#include <linux/config.h>
+#endif
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/version.h>
+#include <linux/unistd.h>
+#include <linux/poll.h>
+#include <linux/random.h>
+#include <cryptodev.h>
+
+#ifdef CONFIG_OCF_FIPS
+#include "rndtest.h"
+#endif
+
+#ifndef HAS_RANDOM_INPUT_WAIT
+#error "Please do not enable OCF_RANDOMHARVEST unless you have applied patches"
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
+#include <linux/sched.h>
+#define kill_proc(p,s,v) send_sig(s,find_task_by_vpid(p),0)
+#endif
+
+/*
+ * a hack to access the debug levels from the crypto driver
+ */
+extern int crypto_debug;
+#define debug crypto_debug
+
+/*
+ * a list of all registered random providers
+ */
+static LIST_HEAD(random_ops);
+static int started = 0;
+static int initted = 0;
+
+struct random_op {
+ struct list_head random_list;
+ u_int32_t driverid;
+ int (*read_random)(void *arg, u_int32_t *buf, int len);
+ void *arg;
+};
+
+static int random_proc(void *arg);
+
+static pid_t randomproc = (pid_t) -1;
+static spinlock_t random_lock;
+
+/*
+ * just init the spin locks
+ */
+static int
+crypto_random_init(void)
+{
+ spin_lock_init(&random_lock);
+ initted = 1;
+ return(0);
+}
+
+/*
+ * Add the given random reader to our list (if not present)
+ * and start the thread (if not already started)
+ *
+ * we have to assume that driver id is ok for now
+ */
+int
+crypto_rregister(
+ u_int32_t driverid,
+ int (*read_random)(void *arg, u_int32_t *buf, int len),
+ void *arg)
+{
+ unsigned long flags;
+ int ret = 0;
+ struct random_op *rops, *tmp;
+
+ dprintk("%s,%d: %s(0x%x, %p, %p)\n", __FILE__, __LINE__,
+ __FUNCTION__, driverid, read_random, arg);
+
+ if (!initted)
+ crypto_random_init();
+
+#if 0
+ struct cryptocap *cap;
+
+ cap = crypto_checkdriver(driverid);
+ if (!cap)
+ return EINVAL;
+#endif
+
+ list_for_each_entry_safe(rops, tmp, &random_ops, random_list) {
+ if (rops->driverid == driverid && rops->read_random == read_random)
+ return EEXIST;
+ }
+
+ rops = (struct random_op *) kmalloc(sizeof(*rops), GFP_KERNEL);
+ if (!rops)
+ return ENOMEM;
+
+ rops->driverid = driverid;
+ rops->read_random = read_random;
+ rops->arg = arg;
+
+ spin_lock_irqsave(&random_lock, flags);
+ list_add_tail(&rops->random_list, &random_ops);
+ if (!started) {
+ randomproc = kernel_thread(random_proc, NULL, CLONE_FS|CLONE_FILES);
+ if (randomproc < 0) {
+ ret = randomproc;
+ printk("crypto: crypto_rregister cannot start random thread; "
+ "error %d", ret);
+ } else
+ started = 1;
+ }
+ spin_unlock_irqrestore(&random_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(crypto_rregister);
+
+int
+crypto_runregister_all(u_int32_t driverid)
+{
+ struct random_op *rops, *tmp;
+ unsigned long flags;
+
+ dprintk("%s,%d: %s(0x%x)\n", __FILE__, __LINE__, __FUNCTION__, driverid);
+
+ list_for_each_entry_safe(rops, tmp, &random_ops, random_list) {
+ if (rops->driverid == driverid) {
+ list_del(&rops->random_list);
+ kfree(rops);
+ }
+ }
+
+ spin_lock_irqsave(&random_lock, flags);
+ if (list_empty(&random_ops) && started)
+ kill_proc(randomproc, SIGKILL, 1);
+ spin_unlock_irqrestore(&random_lock, flags);
+ return(0);
+}
+EXPORT_SYMBOL(crypto_runregister_all);
+
+/*
+ * while we can add entropy to random.c continue to read random data from
+ * the drivers and push it to random.
+ */
+static int
+random_proc(void *arg)
+{
+ int n;
+ int wantcnt;
+ int bufcnt = 0;
+ int retval = 0;
+ int *buf = NULL;
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+ daemonize();
+ spin_lock_irq(¤t->sigmask_lock);
+ sigemptyset(¤t->blocked);
+ recalc_sigpending(current);
+ spin_unlock_irq(¤t->sigmask_lock);
+ sprintf(current->comm, "ocf-random");
+#else
+ daemonize("ocf-random");
+ allow_signal(SIGKILL);
+#endif
+
+ (void) get_fs();
+ set_fs(get_ds());
+
+#ifdef CONFIG_OCF_FIPS
+#define NUM_INT (RNDTEST_NBYTES/sizeof(int))
+#else
+#define NUM_INT 32
+#endif
+
+ /*
+ * some devices can transferr their RNG data direct into memory,
+ * so make sure it is device friendly
+ */
+ buf = kmalloc(NUM_INT * sizeof(int), GFP_DMA);
+ if (NULL == buf) {
+ printk("crypto: RNG could not allocate memory\n");
+ retval = -ENOMEM;
+ goto bad_alloc;
+ }
+
+ wantcnt = NUM_INT; /* start by adding some entropy */
+
+ /*
+ * its possible due to errors or driver removal that we no longer
+ * have anything to do, if so exit or we will consume all the CPU
+ * doing nothing
+ */
+ while (!list_empty(&random_ops)) {
+ struct random_op *rops, *tmp;
+
+#ifdef CONFIG_OCF_FIPS
+ if (wantcnt)
+ wantcnt = NUM_INT; /* FIPs mode can do 20000 bits or none */
+#endif
+
+ /* see if we can get enough entropy to make the world
+ * a better place.
+ */
+ while (bufcnt < wantcnt && bufcnt < NUM_INT) {
+ list_for_each_entry_safe(rops, tmp, &random_ops, random_list) {
+
+ n = (*rops->read_random)(rops->arg, &buf[bufcnt],
+ NUM_INT - bufcnt);
+
+ /* on failure remove the random number generator */
+ if (n == -1) {
+ list_del(&rops->random_list);
+ printk("crypto: RNG (driverid=0x%x) failed, disabling\n",
+ rops->driverid);
+ kfree(rops);
+ } else if (n > 0)
+ bufcnt += n;
+ }
+ /* give up CPU for a bit, just in case as this is a loop */
+ schedule();
+ }
+
+
+#ifdef CONFIG_OCF_FIPS
+ if (bufcnt > 0 && rndtest_buf((unsigned char *) &buf[0])) {
+ dprintk("crypto: buffer had fips errors, discarding\n");
+ bufcnt = 0;
+ }
+#endif
+
+ /*
+ * if we have a certified buffer, we can send some data
+ * to /dev/random and move along
+ */
+ if (bufcnt > 0) {
+ /* add what we have */
+ random_input_words(buf, bufcnt, bufcnt*sizeof(int)*8);
+ bufcnt = 0;
+ }
+
+ /* give up CPU for a bit so we don't hog while filling */
+ schedule();
+
+ /* wait for needing more */
+ wantcnt = random_input_wait();
+
+ if (wantcnt <= 0)
+ wantcnt = 0; /* try to get some info again */
+ else
+ /* round up to one word or we can loop forever */
+ wantcnt = (wantcnt + (sizeof(int)*8)) / (sizeof(int)*8);
+ if (wantcnt > NUM_INT) {
+ wantcnt = NUM_INT;
+ }
+
+ if (signal_pending(current)) {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+ spin_lock_irq(¤t->sigmask_lock);
+#endif
+ flush_signals(current);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+ spin_unlock_irq(¤t->sigmask_lock);
+#endif
+ }
+ }
+
+ kfree(buf);
+
+bad_alloc:
+ spin_lock_irq(&random_lock);
+ randomproc = (pid_t) -1;
+ started = 0;
+ spin_unlock_irq(&random_lock);
+
+ return retval;
+}
+
projects / 15.05 / openwrt.git / blobdiff