/*
* random.c -- A strong random number generator
*
- * Version 1.89, last modified 19-Sep-99
- *
+ * Copyright Matt Mackall <mpm@selenic.com>, 2003, 2004, 2005
+ *
* Copyright Theodore Ts'o, 1994, 1995, 1996, 1997, 1998, 1999. All
* rights reserved.
*
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
- *
+ *
* ALTERNATIVELY, this product may be distributed under the terms of
* the GNU General Public License, in which case the provisions of the GPL are
* required INSTEAD OF the above restrictions. (This clause is
* necessary due to a potential bad interaction between the GPL and
* the restrictions contained in a BSD-style copyright.)
- *
+ *
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
*/
/*
- * (now, with legal B.S. out of the way.....)
- *
+ * (now, with legal B.S. out of the way.....)
+ *
* This routine gathers environmental noise from device drivers, etc.,
* and returns good random numbers, suitable for cryptographic use.
* Besides the obvious cryptographic uses, these numbers are also good
*
* Theory of operation
* ===================
- *
+ *
* Computers are very predictable devices. Hence it is extremely hard
* to produce truly random numbers on a computer --- as opposed to
* pseudo-random numbers, which can easily generated by using a
* must be hard for outside attackers to observe, and use that to
* generate random numbers. In a Unix environment, this is best done
* from inside the kernel.
- *
+ *
* Sources of randomness from the environment include inter-keyboard
* timings, inter-interrupt timings from some interrupts, and other
* events which are both (a) non-deterministic and (b) hard for an
* As random bytes are mixed into the entropy pool, the routines keep
* an *estimate* of how many bits of randomness have been stored into
* the random number generator's internal state.
- *
+ *
* When random bytes are desired, they are obtained by taking the SHA
* hash of the contents of the "entropy pool". The SHA hash avoids
* exposing the internal state of the entropy pool. It is believed to
* reason, the routine decreases its internal estimate of how many
* bits of "true randomness" are contained in the entropy pool as it
* outputs random numbers.
- *
+ *
* If this estimate goes to zero, the routine can still generate
* random numbers; however, an attacker may (at least in theory) be
* able to infer the future output of the generator from prior
* not believed to be feasible, but there is a remote possibility.
* Nonetheless, these numbers should be useful for the vast majority
* of purposes.
- *
+ *
* Exported interfaces ---- output
* ===============================
- *
+ *
* There are three exported interfaces; the first is one designed to
* be used from within the kernel:
*
*
* This interface will return the requested number of random bytes,
* and place it in the requested buffer.
- *
+ *
* The two other interfaces are two character devices /dev/random and
* /dev/urandom. /dev/random is suitable for use when very high
* quality randomness is desired (for example, for key generation or
* one-time pads), as it will only return a maximum of the number of
* bits of randomness (as estimated by the random number generator)
* contained in the entropy pool.
- *
+ *
* The /dev/urandom device does not have this limit, and will return
* as many bytes as are requested. As more and more random bytes are
* requested without giving time for the entropy pool to recharge,
*
* Exported interfaces ---- input
* ==============================
- *
+ *
* The current exported interfaces for gathering environmental noise
* from the devices are:
- *
- * void add_keyboard_randomness(unsigned char scancode);
- * void add_mouse_randomness(__u32 mouse_data);
+ *
+ * void add_input_randomness(unsigned int type, unsigned int code,
+ * unsigned int value);
* void add_interrupt_randomness(int irq);
- *
- * add_keyboard_randomness() uses the inter-keypress timing, as well as the
- * scancode as random inputs into the "entropy pool".
- *
- * add_mouse_randomness() uses the mouse interrupt timing, as well as
- * the reported position of the mouse from the hardware.
+ *
+ * add_input_randomness() uses the input layer interrupt timing, as well as
+ * the event type information from the hardware.
*
* add_interrupt_randomness() uses the inter-interrupt timing as random
* inputs to the entropy pool. Note that not all interrupts are good
* regular, and hence predictable to an attacker. Disk interrupts are
* a better measure, since the timing of the disk interrupts are more
* unpredictable.
- *
+ *
* All of these routines try to estimate how many bits of randomness a
* particular randomness source. They do this by keeping track of the
* first and second order deltas of the event timings.
*
* Ensuring unpredictability at system startup
* ============================================
- *
+ *
* When any operating system starts up, it will go through a sequence
* of actions that are fairly predictable by an adversary, especially
* if the start-up does not involve interaction with a human operator.
* counteract this effect, it helps to carry information in the
* entropy pool across shut-downs and start-ups. To do this, put the
* following lines an appropriate script which is run during the boot
- * sequence:
+ * sequence:
*
* echo "Initializing random number generator..."
* random_seed=/var/run/random-seed
* touch $random_seed
* fi
* chmod 600 $random_seed
- * poolfile=/proc/sys/kernel/random/poolsize
- * [ -r $poolfile ] && bytes=`cat $poolfile` || bytes=512
- * dd if=/dev/urandom of=$random_seed count=1 bs=$bytes
+ * dd if=/dev/urandom of=$random_seed count=1 bs=512
*
* and the following lines in an appropriate script which is run as
* the system is shutdown:
* random_seed=/var/run/random-seed
* touch $random_seed
* chmod 600 $random_seed
- * poolfile=/proc/sys/kernel/random/poolsize
- * [ -r $poolfile ] && bytes=`cat $poolfile` || bytes=512
- * dd if=/dev/urandom of=$random_seed count=1 bs=$bytes
+ * dd if=/dev/urandom of=$random_seed count=1 bs=512
*
* For example, on most modern systems using the System V init
* scripts, such code fragments would be found in
* /etc/rc.d/init.d/random. On older Linux systems, the correct script
* location might be in /etc/rcb.d/rc.local or /etc/rc.d/rc.0.
- *
+ *
* Effectively, these commands cause the contents of the entropy pool
* to be saved at shut-down time and reloaded into the entropy pool at
* start-up. (The 'dd' in the addition to the bootup script is to
*
* mknod /dev/random c 1 8
* mknod /dev/urandom c 1 9
- *
+ *
* Acknowledgements:
* =================
*
* number generator, which speed up the mixing function of the entropy
* pool, taken from PGPfone. Dale Worley has also contributed many
* useful ideas and suggestions to improve this driver.
- *
+ *
* Any flaws in the design are solely my responsibility, and should
* not be attributed to the Phil, Colin, or any of authors of PGP.
- *
- * The code for SHA transform was taken from Peter Gutmann's
- * implementation, which has been placed in the public domain.
- * The code for MD5 transform was taken from Colin Plumb's
- * implementation, which has been placed in the public domain.
- * The MD5 cryptographic checksum was devised by Ronald Rivest, and is
- * documented in RFC 1321, "The MD5 Message Digest Algorithm".
- *
+ *
* Further background information on this topic may be obtained from
* RFC 1750, "Randomness Recommendations for Security", by Donald
* Eastlake, Steve Crocker, and Jeff Schiller.
*/
#include <linux/utsname.h>
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/fs.h>
-#include <linux/workqueue.h>
#include <linux/genhd.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/percpu.h>
+#include <linux/cryptohash.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
/*
* Configuration information
*/
-#define DEFAULT_POOL_SIZE 512
-#define SECONDARY_POOL_SIZE 128
-#define BATCH_ENTROPY_SIZE 256
-#define USE_SHA
+#define INPUT_POOL_WORDS 128
+#define OUTPUT_POOL_WORDS 32
+#define SEC_XFER_SIZE 512
/*
* The minimum number of bits of entropy before we wake up a read on
* samples to avoid wasting CPU time and reduce lock contention.
*/
-static int trickle_thresh = DEFAULT_POOL_SIZE * 7;
+static int trickle_thresh __read_mostly = INPUT_POOL_WORDS * 28;
static DEFINE_PER_CPU(int, trickle_count) = 0;
* get the twisting happening as fast as possible.
*/
static struct poolinfo {
- int poolwords;
- int tap1, tap2, tap3, tap4, tap5;
+ int poolwords;
+ int tap1, tap2, tap3, tap4, tap5;
} poolinfo_table[] = {
+ /* x^128 + x^103 + x^76 + x^51 +x^25 + x + 1 -- 105 */
+ { 128, 103, 76, 51, 25, 1 },
+ /* x^32 + x^26 + x^20 + x^14 + x^7 + x + 1 -- 15 */
+ { 32, 26, 20, 14, 7, 1 },
+#if 0
/* x^2048 + x^1638 + x^1231 + x^819 + x^411 + x + 1 -- 115 */
{ 2048, 1638, 1231, 819, 411, 1 },
/* x^1024 + x^817 + x^615 + x^412 + x^204 + x + 1 -- 290 */
{ 1024, 817, 615, 412, 204, 1 },
-#if 0 /* Alternate polynomial */
+
/* x^1024 + x^819 + x^616 + x^410 + x^207 + x^2 + 1 -- 115 */
{ 1024, 819, 616, 410, 207, 2 },
-#endif
/* x^512 + x^411 + x^308 + x^208 + x^104 + x + 1 -- 225 */
{ 512, 411, 308, 208, 104, 1 },
-#if 0 /* Alternates */
+
/* x^512 + x^409 + x^307 + x^206 + x^102 + x^2 + 1 -- 95 */
{ 512, 409, 307, 206, 102, 2 },
/* x^512 + x^409 + x^309 + x^205 + x^103 + x^2 + 1 -- 95 */
{ 512, 409, 309, 205, 103, 2 },
-#endif
/* x^256 + x^205 + x^155 + x^101 + x^52 + x + 1 -- 125 */
{ 256, 205, 155, 101, 52, 1 },
- /* x^128 + x^103 + x^76 + x^51 +x^25 + x + 1 -- 105 */
- { 128, 103, 76, 51, 25, 1 },
-#if 0 /* Alternate polynomial */
/* x^128 + x^103 + x^78 + x^51 + x^27 + x^2 + 1 -- 70 */
{ 128, 103, 78, 51, 27, 2 },
-#endif
/* x^64 + x^52 + x^39 + x^26 + x^14 + x + 1 -- 15 */
{ 64, 52, 39, 26, 14, 1 },
-
- /* x^32 + x^26 + x^20 + x^14 + x^7 + x + 1 -- 15 */
- { 32, 26, 20, 14, 7, 1 },
-
- { 0, 0, 0, 0, 0, 0 },
+#endif
};
#define POOLBITS poolwords*32
* II. ACM Transactions on Mdeling and Computer Simulation 4:254-266)
*
* Thanks to Colin Plumb for suggesting this.
- *
+ *
* We have not analyzed the resultant polynomial to prove it primitive;
* in fact it almost certainly isn't. Nonetheless, the irreducible factors
* of a random large-degree polynomial over GF(2) are more than large enough
* that periodicity is not a concern.
- *
+ *
* The input hash is much less sensitive than the output hash. All
* that we want of it is that it be a good non-cryptographic hash;
* i.e. it not produce collisions when fed "random" data of the sort
* hash; hash collisions will occur no more often than chance.
*/
-/*
- * Linux 2.2 compatibility
- */
-#ifndef DECLARE_WAITQUEUE
-#define DECLARE_WAITQUEUE(WAIT, PTR) struct wait_queue WAIT = { PTR, NULL }
-#endif
-#ifndef DECLARE_WAIT_QUEUE_HEAD
-#define DECLARE_WAIT_QUEUE_HEAD(WAIT) struct wait_queue *WAIT
-#endif
-
/*
* Static global variables
*/
-static struct entropy_store *random_state; /* The default global store */
-static struct entropy_store *sec_random_state; /* secondary store */
static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
-/*
- * Forward procedure declarations
- */
-#ifdef CONFIG_SYSCTL
-static void sysctl_init_random(struct entropy_store *random_state);
-#endif
-
-/*****************************************************************
- *
- * Utility functions, with some ASM defined functions for speed
- * purposes
- *
- *****************************************************************/
-
-/*
- * Unfortunately, while the GCC optimizer for the i386 understands how
- * to optimize a static rotate left of x bits, it doesn't know how to
- * deal with a variable rotate of x bits. So we use a bit of asm magic.
- */
-#if (!defined (__i386__))
-static inline __u32 rotate_left(int i, __u32 word)
-{
- return (word << i) | (word >> (32 - i));
-
-}
-#else
-static inline __u32 rotate_left(int i, __u32 word)
-{
- __asm__("roll %%cl,%0"
- :"=r" (word)
- :"0" (word),"c" (i));
- return word;
-}
-#endif
-
-/*
- * More asm magic....
- *
- * For entropy estimation, we need to do an integral base 2
- * logarithm.
- *
- * Note the "12bits" suffix - this is used for numbers between
- * 0 and 4095 only. This allows a few shortcuts.
- */
-#if 0 /* Slow but clear version */
-static inline __u32 int_ln_12bits(__u32 word)
-{
- __u32 nbits = 0;
-
- while (word >>= 1)
- nbits++;
- return nbits;
-}
-#else /* Faster (more clever) version, courtesy Colin Plumb */
-static inline __u32 int_ln_12bits(__u32 word)
-{
- /* Smear msbit right to make an n-bit mask */
- word |= word >> 8;
- word |= word >> 4;
- word |= word >> 2;
- word |= word >> 1;
- /* Remove one bit to make this a logarithm */
- word >>= 1;
- /* Count the bits set in the word */
- word -= (word >> 1) & 0x555;
- word = (word & 0x333) + ((word >> 2) & 0x333);
- word += (word >> 4);
- word += (word >> 8);
- return word & 15;
-}
-#endif
-
#if 0
-#define DEBUG_ENT(fmt, arg...) printk(KERN_DEBUG "random: " fmt, ## arg)
+static int debug = 0;
+module_param(debug, bool, 0644);
+#define DEBUG_ENT(fmt, arg...) do { if (debug) \
+ printk(KERN_DEBUG "random %04d %04d %04d: " \
+ fmt,\
+ input_pool.entropy_count,\
+ blocking_pool.entropy_count,\
+ nonblocking_pool.entropy_count,\
+ ## arg); } while (0)
#else
#define DEBUG_ENT(fmt, arg...) do {} while (0)
#endif
*
* OS independent entropy store. Here are the functions which handle
* storing entropy in an entropy pool.
- *
+ *
**********************************************************************/
+struct entropy_store;
struct entropy_store {
/* mostly-read data: */
- struct poolinfo poolinfo;
- __u32 *pool;
+ struct poolinfo *poolinfo;
+ __u32 *pool;
+ const char *name;
+ int limit;
+ struct entropy_store *pull;
/* read-write data: */
spinlock_t lock ____cacheline_aligned_in_smp;
- unsigned add_ptr;
- int entropy_count;
- int input_rotate;
+ unsigned add_ptr;
+ int entropy_count;
+ int input_rotate;
};
-/*
- * Initialize the entropy store. The input argument is the size of
- * the random pool.
- *
- * Returns an negative error if there is a problem.
- */
-static int create_entropy_store(int size, struct entropy_store **ret_bucket)
-{
- struct entropy_store *r;
- struct poolinfo *p;
- int poolwords;
-
- poolwords = (size + 3) / 4; /* Convert bytes->words */
- /* The pool size must be a multiple of 16 32-bit words */
- poolwords = ((poolwords + 15) / 16) * 16;
-
- for (p = poolinfo_table; p->poolwords; p++) {
- if (poolwords == p->poolwords)
- break;
- }
- if (p->poolwords == 0)
- return -EINVAL;
+static __u32 input_pool_data[INPUT_POOL_WORDS];
+static __u32 blocking_pool_data[OUTPUT_POOL_WORDS];
+static __u32 nonblocking_pool_data[OUTPUT_POOL_WORDS];
- r = kmalloc(sizeof(struct entropy_store), GFP_KERNEL);
- if (!r)
- return -ENOMEM;
+static struct entropy_store input_pool = {
+ .poolinfo = &poolinfo_table[0],
+ .name = "input",
+ .limit = 1,
+ .lock = __SPIN_LOCK_UNLOCKED(&input_pool.lock),
+ .pool = input_pool_data
+};
- memset (r, 0, sizeof(struct entropy_store));
- r->poolinfo = *p;
+static struct entropy_store blocking_pool = {
+ .poolinfo = &poolinfo_table[1],
+ .name = "blocking",
+ .limit = 1,
+ .pull = &input_pool,
+ .lock = __SPIN_LOCK_UNLOCKED(&blocking_pool.lock),
+ .pool = blocking_pool_data
+};
- r->pool = kmalloc(POOLBYTES, GFP_KERNEL);
- if (!r->pool) {
- kfree(r);
- return -ENOMEM;
- }
- memset(r->pool, 0, POOLBYTES);
- r->lock = SPIN_LOCK_UNLOCKED;
- *ret_bucket = r;
- return 0;
-}
+static struct entropy_store nonblocking_pool = {
+ .poolinfo = &poolinfo_table[1],
+ .name = "nonblocking",
+ .pull = &input_pool,
+ .lock = __SPIN_LOCK_UNLOCKED(&nonblocking_pool.lock),
+ .pool = nonblocking_pool_data
+};
-/* Clear the entropy pool and associated counters. */
-static void clear_entropy_store(struct entropy_store *r)
-{
- r->add_ptr = 0;
- r->entropy_count = 0;
- r->input_rotate = 0;
- memset(r->pool, 0, r->poolinfo.POOLBYTES);
-}
-#ifdef CONFIG_SYSCTL
-static void free_entropy_store(struct entropy_store *r)
-{
- if (r->pool)
- kfree(r->pool);
- kfree(r);
-}
-#endif
/*
* This function adds a byte into the entropy "pool". It does not
* update the entropy estimate. The caller should call
* credit_entropy_store if this is appropriate.
- *
+ *
* The pool is stirred with a primitive polynomial of the appropriate
* degree, and then twisted. We twist by three bits at a time because
* it's cheap to do so and helps slightly in the expected case where
* the entropy is concentrated in the low-order bits.
*/
-static void add_entropy_words(struct entropy_store *r, const __u32 *in,
- int nwords)
+static void __add_entropy_words(struct entropy_store *r, const __u32 *in,
+ int nwords, __u32 out[16])
{
static __u32 const twist_table[8] = {
- 0, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
+ 0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
unsigned long i, add_ptr, tap1, tap2, tap3, tap4, tap5;
int new_rotate, input_rotate;
- int wordmask = r->poolinfo.poolwords - 1;
+ int wordmask = r->poolinfo->poolwords - 1;
__u32 w, next_w;
unsigned long flags;
/* Taps are constant, so we can load them without holding r->lock. */
- tap1 = r->poolinfo.tap1;
- tap2 = r->poolinfo.tap2;
- tap3 = r->poolinfo.tap3;
- tap4 = r->poolinfo.tap4;
- tap5 = r->poolinfo.tap5;
+ tap1 = r->poolinfo->tap1;
+ tap2 = r->poolinfo->tap2;
+ tap3 = r->poolinfo->tap3;
+ tap4 = r->poolinfo->tap4;
+ tap5 = r->poolinfo->tap5;
next_w = *in++;
spin_lock_irqsave(&r->lock, flags);
add_ptr = r->add_ptr;
while (nwords--) {
- w = rotate_left(input_rotate, next_w);
+ w = rol32(next_w, input_rotate);
if (nwords > 0)
next_w = *in++;
i = add_ptr = (add_ptr - 1) & wordmask;
r->input_rotate = input_rotate;
r->add_ptr = add_ptr;
+ if (out) {
+ for (i = 0; i < 16; i++) {
+ out[i] = r->pool[add_ptr];
+ add_ptr = (add_ptr - 1) & wordmask;
+ }
+ }
+
spin_unlock_irqrestore(&r->lock, flags);
}
+static inline void add_entropy_words(struct entropy_store *r, const __u32 *in,
+ int nwords)
+{
+ __add_entropy_words(r, in, nwords, NULL);
+}
+
/*
* Credit (or debit) the entropy store with n bits of entropy
*/
DEBUG_ENT("negative entropy/overflow (%d+%d)\n",
r->entropy_count, nbits);
r->entropy_count = 0;
- } else if (r->entropy_count + nbits > r->poolinfo.POOLBITS) {
- r->entropy_count = r->poolinfo.POOLBITS;
+ } else if (r->entropy_count + nbits > r->poolinfo->POOLBITS) {
+ r->entropy_count = r->poolinfo->POOLBITS;
} else {
r->entropy_count += nbits;
if (nbits)
- DEBUG_ENT("%04d %04d : added %d bits to %s\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- nbits,
- r == sec_random_state ? "secondary" :
- r == random_state ? "primary" : "unknown");
+ DEBUG_ENT("added %d entropy credits to %s\n",
+ nbits, r->name);
}
spin_unlock_irqrestore(&r->lock, flags);
}
-/**********************************************************************
- *
- * Entropy batch input management
- *
- * We batch entropy to be added to avoid increasing interrupt latency
- *
- **********************************************************************/
-
-struct sample {
- __u32 data[2];
- int credit;
-};
-
-static struct sample *batch_entropy_pool, *batch_entropy_copy;
-static int batch_head, batch_tail;
-static spinlock_t batch_lock = SPIN_LOCK_UNLOCKED;
-
-static int batch_max;
-static void batch_entropy_process(void *private_);
-static DECLARE_WORK(batch_work, batch_entropy_process, NULL);
-
-/* note: the size must be a power of 2 */
-static int __init batch_entropy_init(int size, struct entropy_store *r)
-{
- batch_entropy_pool = kmalloc(size*sizeof(struct sample), GFP_KERNEL);
- if (!batch_entropy_pool)
- return -1;
- batch_entropy_copy = kmalloc(size*sizeof(struct sample), GFP_KERNEL);
- if (!batch_entropy_copy) {
- kfree(batch_entropy_pool);
- return -1;
- }
- batch_head = batch_tail = 0;
- batch_work.data = r;
- batch_max = size;
- return 0;
-}
-
-/*
- * Changes to the entropy data is put into a queue rather than being added to
- * the entropy counts directly. This is presumably to avoid doing heavy
- * hashing calculations during an interrupt in add_timer_randomness().
- * Instead, the entropy is only added to the pool by keventd.
- */
-void batch_entropy_store(u32 a, u32 b, int num)
-{
- int new;
- unsigned long flags;
-
- if (!batch_max)
- return;
-
- spin_lock_irqsave(&batch_lock, flags);
-
- batch_entropy_pool[batch_head].data[0] = a;
- batch_entropy_pool[batch_head].data[1] = b;
- batch_entropy_pool[batch_head].credit = num;
-
- if (((batch_head - batch_tail) & (batch_max-1)) >= (batch_max / 2)) {
- /*
- * Schedule it for the next timer tick:
- */
- schedule_delayed_work(&batch_work, 1);
- }
-
- new = (batch_head+1) & (batch_max-1);
- if (new == batch_tail) {
- DEBUG_ENT("batch entropy buffer full\n");
- } else {
- batch_head = new;
- }
-
- spin_unlock_irqrestore(&batch_lock, flags);
-}
-
-EXPORT_SYMBOL(batch_entropy_store);
-
-/*
- * Flush out the accumulated entropy operations, adding entropy to the passed
- * store (normally random_state). If that store has enough entropy, alternate
- * between randomizing the data of the primary and secondary stores.
- */
-static void batch_entropy_process(void *private_)
-{
- struct entropy_store *r = (struct entropy_store *) private_, *p;
- int max_entropy = r->poolinfo.POOLBITS;
- unsigned head, tail;
-
- /* Mixing into the pool is expensive, so copy over the batch
- * data and release the batch lock. The pool is at least half
- * full, so don't worry too much about copying only the used
- * part.
- */
- spin_lock_irq(&batch_lock);
-
- memcpy(batch_entropy_copy, batch_entropy_pool,
- batch_max*sizeof(struct sample));
-
- head = batch_head;
- tail = batch_tail;
- batch_tail = batch_head;
-
- spin_unlock_irq(&batch_lock);
-
- p = r;
- while (head != tail) {
- if (r->entropy_count >= max_entropy) {
- r = (r == sec_random_state) ? random_state :
- sec_random_state;
- max_entropy = r->poolinfo.POOLBITS;
- }
- add_entropy_words(r, batch_entropy_copy[tail].data, 2);
- credit_entropy_store(r, batch_entropy_copy[tail].credit);
- tail = (tail+1) & (batch_max-1);
- }
- if (p->entropy_count >= random_read_wakeup_thresh)
- wake_up_interruptible(&random_read_wait);
-}
-
/*********************************************************************
*
* Entropy input management
/* There is one of these per entropy source */
struct timer_rand_state {
- __u32 last_time;
- __s32 last_delta,last_delta2;
- int dont_count_entropy:1;
+ cycles_t last_time;
+ long last_delta,last_delta2;
+ unsigned dont_count_entropy:1;
};
-static struct timer_rand_state keyboard_timer_state;
-static struct timer_rand_state mouse_timer_state;
-static struct timer_rand_state extract_timer_state;
+static struct timer_rand_state input_timer_state;
static struct timer_rand_state *irq_timer_state[NR_IRQS];
/*
* The number "num" is also added to the pool - it should somehow describe
* the type of event which just happened. This is currently 0-255 for
* keyboard scan codes, and 256 upwards for interrupts.
- * On the i386, this is assumed to be at most 16 bits, and the high bits
- * are used for a high-resolution timer.
*
*/
static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
{
- __u32 time;
- __s32 delta, delta2, delta3;
- int entropy = 0;
-
+ struct {
+ cycles_t cycles;
+ long jiffies;
+ unsigned num;
+ } sample;
+ long delta, delta2, delta3;
+
+ preempt_disable();
/* if over the trickle threshold, use only 1 in 4096 samples */
- if ( random_state->entropy_count > trickle_thresh &&
- (__get_cpu_var(trickle_count)++ & 0xfff))
- return;
+ if (input_pool.entropy_count > trickle_thresh &&
+ (__get_cpu_var(trickle_count)++ & 0xfff))
+ goto out;
-#if defined (__i386__) || defined (__x86_64__)
- if (cpu_has_tsc) {
- __u32 high;
- rdtsc(time, high);
- num ^= high;
- } else {
- time = jiffies;
- }
-#else
- time = jiffies;
-#endif
+ sample.jiffies = jiffies;
+ sample.cycles = get_cycles();
+ sample.num = num;
+ add_entropy_words(&input_pool, (u32 *)&sample, sizeof(sample)/4);
/*
* Calculate number of bits of randomness we probably added.
* We take into account the first, second and third-order deltas
* in order to make our estimate.
*/
+
if (!state->dont_count_entropy) {
- delta = time - state->last_time;
- state->last_time = time;
+ delta = sample.jiffies - state->last_time;
+ state->last_time = sample.jiffies;
delta2 = delta - state->last_delta;
state->last_delta = delta;
* Round down by 1 bit on general principles,
* and limit entropy entimate to 12 bits.
*/
- delta >>= 1;
- delta &= (1 << 12) - 1;
-
- entropy = int_ln_12bits(delta);
+ credit_entropy_store(&input_pool,
+ min_t(int, fls(delta>>1), 11));
}
- batch_entropy_store(num, time, entropy);
+
+ if(input_pool.entropy_count >= random_read_wakeup_thresh)
+ wake_up_interruptible(&random_read_wait);
+
+out:
+ preempt_enable();
}
-void add_keyboard_randomness(unsigned char scancode)
+void add_input_randomness(unsigned int type, unsigned int code,
+ unsigned int value)
{
- static unsigned char last_scancode;
- /* ignore autorepeat (multiple key down w/o key up) */
- if (scancode != last_scancode) {
- last_scancode = scancode;
- add_timer_randomness(&keyboard_timer_state, scancode);
- }
-}
+ static unsigned char last_value;
-EXPORT_SYMBOL(add_keyboard_randomness);
+ /* ignore autorepeat and the like */
+ if (value == last_value)
+ return;
-void add_mouse_randomness(__u32 mouse_data)
-{
- add_timer_randomness(&mouse_timer_state, mouse_data);
+ DEBUG_ENT("input event\n");
+ last_value = value;
+ add_timer_randomness(&input_timer_state,
+ (type << 4) ^ code ^ (code >> 4) ^ value);
}
-
-EXPORT_SYMBOL(add_mouse_randomness);
+EXPORT_SYMBOL_GPL(add_input_randomness);
void add_interrupt_randomness(int irq)
{
if (irq >= NR_IRQS || irq_timer_state[irq] == 0)
return;
- add_timer_randomness(irq_timer_state[irq], 0x100+irq);
+ DEBUG_ENT("irq event %d\n", irq);
+ add_timer_randomness(irq_timer_state[irq], 0x100 + irq);
}
-EXPORT_SYMBOL(add_interrupt_randomness);
-
+#ifdef CONFIG_BLOCK
void add_disk_randomness(struct gendisk *disk)
{
if (!disk || !disk->random)
return;
/* first major is 1, so we get >= 0x200 here */
- add_timer_randomness(disk->random, 0x100+MKDEV(disk->major, disk->first_minor));
+ DEBUG_ENT("disk event %d:%d\n", disk->major, disk->first_minor);
+
+ add_timer_randomness(disk->random,
+ 0x100 + MKDEV(disk->major, disk->first_minor));
}
EXPORT_SYMBOL(add_disk_randomness);
-
-/******************************************************************
- *
- * Hash function definition
- *
- *******************************************************************/
-
-/*
- * This chunk of code defines a function
- * void HASH_TRANSFORM(__u32 digest[HASH_BUFFER_SIZE + HASH_EXTRA_SIZE],
- * __u32 const data[16])
- *
- * The function hashes the input data to produce a digest in the first
- * HASH_BUFFER_SIZE words of the digest[] array, and uses HASH_EXTRA_SIZE
- * more words for internal purposes. (This buffer is exported so the
- * caller can wipe it once rather than this code doing it each call,
- * and tacking it onto the end of the digest[] array is the quick and
- * dirty way of doing it.)
- *
- * It so happens that MD5 and SHA share most of the initial vector
- * used to initialize the digest[] array before the first call:
- * 1) 0x67452301
- * 2) 0xefcdab89
- * 3) 0x98badcfe
- * 4) 0x10325476
- * 5) 0xc3d2e1f0 (SHA only)
- *
- * For /dev/random purposes, the length of the data being hashed is
- * fixed in length, so appending a bit count in the usual way is not
- * cryptographically necessary.
- */
-
-#ifdef USE_SHA
-
-#define HASH_BUFFER_SIZE 5
-#define HASH_EXTRA_SIZE 80
-#define HASH_TRANSFORM SHATransform
-
-/* Various size/speed tradeoffs are available. Choose 0..3. */
-#define SHA_CODE_SIZE 0
-
-/*
- * SHA transform algorithm, taken from code written by Peter Gutmann,
- * and placed in the public domain.
- */
-
-/* The SHA f()-functions. */
-
-#define f1(x,y,z) ( z ^ (x & (y^z)) ) /* Rounds 0-19: x ? y : z */
-#define f2(x,y,z) (x ^ y ^ z) /* Rounds 20-39: XOR */
-#define f3(x,y,z) ( (x & y) + (z & (x ^ y)) ) /* Rounds 40-59: majority */
-#define f4(x,y,z) (x ^ y ^ z) /* Rounds 60-79: XOR */
-
-/* The SHA Mysterious Constants */
-
-#define K1 0x5A827999L /* Rounds 0-19: sqrt(2) * 2^30 */
-#define K2 0x6ED9EBA1L /* Rounds 20-39: sqrt(3) * 2^30 */
-#define K3 0x8F1BBCDCL /* Rounds 40-59: sqrt(5) * 2^30 */
-#define K4 0xCA62C1D6L /* Rounds 60-79: sqrt(10) * 2^30 */
-
-#define ROTL(n,X) ( ( ( X ) << n ) | ( ( X ) >> ( 32 - n ) ) )
-
-#define subRound(a, b, c, d, e, f, k, data) \
- ( e += ROTL( 5, a ) + f( b, c, d ) + k + data, b = ROTL( 30, b ) )
-
-
-static void SHATransform(__u32 digest[85], __u32 const data[16])
-{
- __u32 A, B, C, D, E; /* Local vars */
- __u32 TEMP;
- int i;
-#define W (digest + HASH_BUFFER_SIZE) /* Expanded data array */
-
- /*
- * Do the preliminary expansion of 16 to 80 words. Doing it
- * out-of-line line this is faster than doing it in-line on
- * register-starved machines like the x86, and not really any
- * slower on real processors.
- */
- memcpy(W, data, 16*sizeof(__u32));
- for (i = 0; i < 64; i++) {
- TEMP = W[i] ^ W[i+2] ^ W[i+8] ^ W[i+13];
- W[i+16] = ROTL(1, TEMP);
- }
-
- /* Set up first buffer and local data buffer */
- A = digest[ 0 ];
- B = digest[ 1 ];
- C = digest[ 2 ];
- D = digest[ 3 ];
- E = digest[ 4 ];
-
- /* Heavy mangling, in 4 sub-rounds of 20 iterations each. */
-#if SHA_CODE_SIZE == 0
- /*
- * Approximately 50% of the speed of the largest version, but
- * takes up 1/16 the space. Saves about 6k on an i386 kernel.
- */
- for (i = 0; i < 80; i++) {
- if (i < 40) {
- if (i < 20)
- TEMP = f1(B, C, D) + K1;
- else
- TEMP = f2(B, C, D) + K2;
- } else {
- if (i < 60)
- TEMP = f3(B, C, D) + K3;
- else
- TEMP = f4(B, C, D) + K4;
- }
- TEMP += ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
-#elif SHA_CODE_SIZE == 1
- for (i = 0; i < 20; i++) {
- TEMP = f1(B, C, D) + K1 + ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
- for (; i < 40; i++) {
- TEMP = f2(B, C, D) + K2 + ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
- for (; i < 60; i++) {
- TEMP = f3(B, C, D) + K3 + ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
- for (; i < 80; i++) {
- TEMP = f4(B, C, D) + K4 + ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
-#elif SHA_CODE_SIZE == 2
- for (i = 0; i < 20; i += 5) {
- subRound( A, B, C, D, E, f1, K1, W[ i ] );
- subRound( E, A, B, C, D, f1, K1, W[ i+1 ] );
- subRound( D, E, A, B, C, f1, K1, W[ i+2 ] );
- subRound( C, D, E, A, B, f1, K1, W[ i+3 ] );
- subRound( B, C, D, E, A, f1, K1, W[ i+4 ] );
- }
- for (; i < 40; i += 5) {
- subRound( A, B, C, D, E, f2, K2, W[ i ] );
- subRound( E, A, B, C, D, f2, K2, W[ i+1 ] );
- subRound( D, E, A, B, C, f2, K2, W[ i+2 ] );
- subRound( C, D, E, A, B, f2, K2, W[ i+3 ] );
- subRound( B, C, D, E, A, f2, K2, W[ i+4 ] );
- }
- for (; i < 60; i += 5) {
- subRound( A, B, C, D, E, f3, K3, W[ i ] );
- subRound( E, A, B, C, D, f3, K3, W[ i+1 ] );
- subRound( D, E, A, B, C, f3, K3, W[ i+2 ] );
- subRound( C, D, E, A, B, f3, K3, W[ i+3 ] );
- subRound( B, C, D, E, A, f3, K3, W[ i+4 ] );
- }
- for (; i < 80; i += 5) {
- subRound( A, B, C, D, E, f4, K4, W[ i ] );
- subRound( E, A, B, C, D, f4, K4, W[ i+1 ] );
- subRound( D, E, A, B, C, f4, K4, W[ i+2 ] );
- subRound( C, D, E, A, B, f4, K4, W[ i+3 ] );
- subRound( B, C, D, E, A, f4, K4, W[ i+4 ] );
- }
-#elif SHA_CODE_SIZE == 3 /* Really large version */
- subRound( A, B, C, D, E, f1, K1, W[ 0 ] );
- subRound( E, A, B, C, D, f1, K1, W[ 1 ] );
- subRound( D, E, A, B, C, f1, K1, W[ 2 ] );
- subRound( C, D, E, A, B, f1, K1, W[ 3 ] );
- subRound( B, C, D, E, A, f1, K1, W[ 4 ] );
- subRound( A, B, C, D, E, f1, K1, W[ 5 ] );
- subRound( E, A, B, C, D, f1, K1, W[ 6 ] );
- subRound( D, E, A, B, C, f1, K1, W[ 7 ] );
- subRound( C, D, E, A, B, f1, K1, W[ 8 ] );
- subRound( B, C, D, E, A, f1, K1, W[ 9 ] );
- subRound( A, B, C, D, E, f1, K1, W[ 10 ] );
- subRound( E, A, B, C, D, f1, K1, W[ 11 ] );
- subRound( D, E, A, B, C, f1, K1, W[ 12 ] );
- subRound( C, D, E, A, B, f1, K1, W[ 13 ] );
- subRound( B, C, D, E, A, f1, K1, W[ 14 ] );
- subRound( A, B, C, D, E, f1, K1, W[ 15 ] );
- subRound( E, A, B, C, D, f1, K1, W[ 16 ] );
- subRound( D, E, A, B, C, f1, K1, W[ 17 ] );
- subRound( C, D, E, A, B, f1, K1, W[ 18 ] );
- subRound( B, C, D, E, A, f1, K1, W[ 19 ] );
-
- subRound( A, B, C, D, E, f2, K2, W[ 20 ] );
- subRound( E, A, B, C, D, f2, K2, W[ 21 ] );
- subRound( D, E, A, B, C, f2, K2, W[ 22 ] );
- subRound( C, D, E, A, B, f2, K2, W[ 23 ] );
- subRound( B, C, D, E, A, f2, K2, W[ 24 ] );
- subRound( A, B, C, D, E, f2, K2, W[ 25 ] );
- subRound( E, A, B, C, D, f2, K2, W[ 26 ] );
- subRound( D, E, A, B, C, f2, K2, W[ 27 ] );
- subRound( C, D, E, A, B, f2, K2, W[ 28 ] );
- subRound( B, C, D, E, A, f2, K2, W[ 29 ] );
- subRound( A, B, C, D, E, f2, K2, W[ 30 ] );
- subRound( E, A, B, C, D, f2, K2, W[ 31 ] );
- subRound( D, E, A, B, C, f2, K2, W[ 32 ] );
- subRound( C, D, E, A, B, f2, K2, W[ 33 ] );
- subRound( B, C, D, E, A, f2, K2, W[ 34 ] );
- subRound( A, B, C, D, E, f2, K2, W[ 35 ] );
- subRound( E, A, B, C, D, f2, K2, W[ 36 ] );
- subRound( D, E, A, B, C, f2, K2, W[ 37 ] );
- subRound( C, D, E, A, B, f2, K2, W[ 38 ] );
- subRound( B, C, D, E, A, f2, K2, W[ 39 ] );
-
- subRound( A, B, C, D, E, f3, K3, W[ 40 ] );
- subRound( E, A, B, C, D, f3, K3, W[ 41 ] );
- subRound( D, E, A, B, C, f3, K3, W[ 42 ] );
- subRound( C, D, E, A, B, f3, K3, W[ 43 ] );
- subRound( B, C, D, E, A, f3, K3, W[ 44 ] );
- subRound( A, B, C, D, E, f3, K3, W[ 45 ] );
- subRound( E, A, B, C, D, f3, K3, W[ 46 ] );
- subRound( D, E, A, B, C, f3, K3, W[ 47 ] );
- subRound( C, D, E, A, B, f3, K3, W[ 48 ] );
- subRound( B, C, D, E, A, f3, K3, W[ 49 ] );
- subRound( A, B, C, D, E, f3, K3, W[ 50 ] );
- subRound( E, A, B, C, D, f3, K3, W[ 51 ] );
- subRound( D, E, A, B, C, f3, K3, W[ 52 ] );
- subRound( C, D, E, A, B, f3, K3, W[ 53 ] );
- subRound( B, C, D, E, A, f3, K3, W[ 54 ] );
- subRound( A, B, C, D, E, f3, K3, W[ 55 ] );
- subRound( E, A, B, C, D, f3, K3, W[ 56 ] );
- subRound( D, E, A, B, C, f3, K3, W[ 57 ] );
- subRound( C, D, E, A, B, f3, K3, W[ 58 ] );
- subRound( B, C, D, E, A, f3, K3, W[ 59 ] );
-
- subRound( A, B, C, D, E, f4, K4, W[ 60 ] );
- subRound( E, A, B, C, D, f4, K4, W[ 61 ] );
- subRound( D, E, A, B, C, f4, K4, W[ 62 ] );
- subRound( C, D, E, A, B, f4, K4, W[ 63 ] );
- subRound( B, C, D, E, A, f4, K4, W[ 64 ] );
- subRound( A, B, C, D, E, f4, K4, W[ 65 ] );
- subRound( E, A, B, C, D, f4, K4, W[ 66 ] );
- subRound( D, E, A, B, C, f4, K4, W[ 67 ] );
- subRound( C, D, E, A, B, f4, K4, W[ 68 ] );
- subRound( B, C, D, E, A, f4, K4, W[ 69 ] );
- subRound( A, B, C, D, E, f4, K4, W[ 70 ] );
- subRound( E, A, B, C, D, f4, K4, W[ 71 ] );
- subRound( D, E, A, B, C, f4, K4, W[ 72 ] );
- subRound( C, D, E, A, B, f4, K4, W[ 73 ] );
- subRound( B, C, D, E, A, f4, K4, W[ 74 ] );
- subRound( A, B, C, D, E, f4, K4, W[ 75 ] );
- subRound( E, A, B, C, D, f4, K4, W[ 76 ] );
- subRound( D, E, A, B, C, f4, K4, W[ 77 ] );
- subRound( C, D, E, A, B, f4, K4, W[ 78 ] );
- subRound( B, C, D, E, A, f4, K4, W[ 79 ] );
-#else
-#error Illegal SHA_CODE_SIZE
#endif
- /* Build message digest */
- digest[ 0 ] += A;
- digest[ 1 ] += B;
- digest[ 2 ] += C;
- digest[ 3 ] += D;
- digest[ 4 ] += E;
-
- /* W is wiped by the caller */
-#undef W
-}
-
-#undef ROTL
-#undef f1
-#undef f2
-#undef f3
-#undef f4
-#undef K1
-#undef K2
-#undef K3
-#undef K4
-#undef subRound
-
-#else /* !USE_SHA - Use MD5 */
-
-#define HASH_BUFFER_SIZE 4
-#define HASH_EXTRA_SIZE 0
-#define HASH_TRANSFORM MD5Transform
-
-/*
- * MD5 transform algorithm, taken from code written by Colin Plumb,
- * and put into the public domain
- */
-
-/* The four core functions - F1 is optimized somewhat */
-
-/* #define F1(x, y, z) (x & y | ~x & z) */
-#define F1(x, y, z) (z ^ (x & (y ^ z)))
-#define F2(x, y, z) F1(z, x, y)
-#define F3(x, y, z) (x ^ y ^ z)
-#define F4(x, y, z) (y ^ (x | ~z))
-
-/* This is the central step in the MD5 algorithm. */
-#define MD5STEP(f, w, x, y, z, data, s) \
- ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
-
-/*
- * The core of the MD5 algorithm, this alters an existing MD5 hash to
- * reflect the addition of 16 longwords of new data. MD5Update blocks
- * the data and converts bytes into longwords for this routine.
- */
-static void MD5Transform(__u32 buf[HASH_BUFFER_SIZE], __u32 const in[16])
-{
- __u32 a, b, c, d;
-
- a = buf[0];
- b = buf[1];
- c = buf[2];
- d = buf[3];
-
- MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478, 7);
- MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
- MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
- MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
- MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf, 7);
- MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
- MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
- MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
- MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8, 7);
- MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
- MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
- MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
- MD5STEP(F1, a, b, c, d, in[12]+0x6b901122, 7);
- MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
- MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
- MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
-
- MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562, 5);
- MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340, 9);
- MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
- MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
- MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d, 5);
- MD5STEP(F2, d, a, b, c, in[10]+0x02441453, 9);
- MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
- MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
- MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6, 5);
- MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6, 9);
- MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
- MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
- MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905, 5);
- MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8, 9);
- MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
- MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
-
- MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942, 4);
- MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
- MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
- MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
- MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44, 4);
- MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
- MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
- MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
- MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6, 4);
- MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
- MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
- MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
- MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039, 4);
- MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
- MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
- MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
-
- MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244, 6);
- MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
- MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
- MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
- MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3, 6);
- MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
- MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
- MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
- MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f, 6);
- MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
- MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
- MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
- MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82, 6);
- MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
- MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
- MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
-
- buf[0] += a;
- buf[1] += b;
- buf[2] += c;
- buf[3] += d;
-}
-
-#undef F1
-#undef F2
-#undef F3
-#undef F4
-#undef MD5STEP
-
-#endif /* !USE_SHA */
+#define EXTRACT_SIZE 10
/*********************************************************************
*
*
*********************************************************************/
-#define EXTRACT_ENTROPY_USER 1
-#define EXTRACT_ENTROPY_SECONDARY 2
-#define EXTRACT_ENTROPY_LIMIT 4
-#define TMP_BUF_SIZE (HASH_BUFFER_SIZE + HASH_EXTRA_SIZE)
-#define SEC_XFER_SIZE (TMP_BUF_SIZE*4)
-
static ssize_t extract_entropy(struct entropy_store *r, void * buf,
- size_t nbytes, int flags);
+ size_t nbytes, int min, int rsvd);
/*
* This utility inline function is responsible for transfering entropy
* from the primary pool to the secondary extraction pool. We make
* sure we pull enough for a 'catastrophic reseed'.
*/
-static inline void xfer_secondary_pool(struct entropy_store *r,
- size_t nbytes, __u32 *tmp)
+static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
{
- if (r->entropy_count < nbytes * 8 &&
- r->entropy_count < r->poolinfo.POOLBITS) {
+ __u32 tmp[OUTPUT_POOL_WORDS];
+
+ if (r->pull && r->entropy_count < nbytes * 8 &&
+ r->entropy_count < r->poolinfo->POOLBITS) {
int bytes = max_t(int, random_read_wakeup_thresh / 8,
- min_t(int, nbytes, TMP_BUF_SIZE));
+ min_t(int, nbytes, sizeof(tmp)));
+ int rsvd = r->limit ? 0 : random_read_wakeup_thresh/4;
- DEBUG_ENT("%04d %04d : going to reseed %s with %d bits "
+ DEBUG_ENT("going to reseed %s with %d bits "
"(%d of %d requested)\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- r == sec_random_state ? "secondary" : "unknown",
- bytes * 8, nbytes * 8, r->entropy_count);
-
- bytes=extract_entropy(random_state, tmp, bytes,
- EXTRACT_ENTROPY_LIMIT);
- add_entropy_words(r, tmp, bytes);
+ r->name, bytes * 8, nbytes * 8, r->entropy_count);
+
+ bytes=extract_entropy(r->pull, tmp, bytes,
+ random_read_wakeup_thresh / 8, rsvd);
+ add_entropy_words(r, tmp, (bytes + 3) / 4);
credit_entropy_store(r, bytes*8);
}
}
/*
- * This function extracts randomness from the "entropy pool", and
- * returns it in a buffer. This function computes how many remaining
- * bits of entropy are left in the pool, but it does not restrict the
- * number of bytes that are actually obtained. If the EXTRACT_ENTROPY_USER
- * flag is given, then the buf pointer is assumed to be in user space.
+ * These functions extracts randomness from the "entropy pool", and
+ * returns it in a buffer.
*
- * If the EXTRACT_ENTROPY_SECONDARY flag is given, then we are actually
- * extracting entropy from the secondary pool, and can refill from the
- * primary pool if needed.
+ * The min parameter specifies the minimum amount we can pull before
+ * failing to avoid races that defeat catastrophic reseeding while the
+ * reserved parameter indicates how much entropy we must leave in the
+ * pool after each pull to avoid starving other readers.
*
* Note: extract_entropy() assumes that .poolwords is a multiple of 16 words.
*/
-static ssize_t extract_entropy(struct entropy_store *r, void * buf,
- size_t nbytes, int flags)
+
+static size_t account(struct entropy_store *r, size_t nbytes, int min,
+ int reserved)
{
- ssize_t ret, i;
- __u32 tmp[TMP_BUF_SIZE];
- __u32 x;
- unsigned long cpuflags;
+ unsigned long flags;
+ BUG_ON(r->entropy_count > r->poolinfo->POOLBITS);
- /* Redundant, but just in case... */
- if (r->entropy_count > r->poolinfo.POOLBITS)
- r->entropy_count = r->poolinfo.POOLBITS;
+ /* Hold lock while accounting */
+ spin_lock_irqsave(&r->lock, flags);
- if (flags & EXTRACT_ENTROPY_SECONDARY)
- xfer_secondary_pool(r, nbytes, tmp);
+ DEBUG_ENT("trying to extract %d bits from %s\n",
+ nbytes * 8, r->name);
- /* Hold lock while accounting */
- spin_lock_irqsave(&r->lock, cpuflags);
+ /* Can we pull enough? */
+ if (r->entropy_count / 8 < min + reserved) {
+ nbytes = 0;
+ } else {
+ /* If limited, never pull more than available */
+ if (r->limit && nbytes + reserved >= r->entropy_count / 8)
+ nbytes = r->entropy_count/8 - reserved;
- DEBUG_ENT("%04d %04d : trying to extract %d bits from %s\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- nbytes * 8,
- r == sec_random_state ? "secondary" :
- r == random_state ? "primary" : "unknown");
+ if(r->entropy_count / 8 >= nbytes + reserved)
+ r->entropy_count -= nbytes*8;
+ else
+ r->entropy_count = reserved;
- if (flags & EXTRACT_ENTROPY_LIMIT && nbytes >= r->entropy_count / 8)
- nbytes = r->entropy_count / 8;
+ if (r->entropy_count < random_write_wakeup_thresh)
+ wake_up_interruptible(&random_write_wait);
+ }
- if (r->entropy_count / 8 >= nbytes)
- r->entropy_count -= nbytes*8;
- else
- r->entropy_count = 0;
+ DEBUG_ENT("debiting %d entropy credits from %s%s\n",
+ nbytes * 8, r->name, r->limit ? "" : " (unlimited)");
+
+ spin_unlock_irqrestore(&r->lock, flags);
+
+ return nbytes;
+}
+
+static void extract_buf(struct entropy_store *r, __u8 *out)
+{
+ int i, x;
+ __u32 data[16], buf[5 + SHA_WORKSPACE_WORDS];
+
+ sha_init(buf);
+ /*
+ * As we hash the pool, we mix intermediate values of
+ * the hash back into the pool. This eliminates
+ * backtracking attacks (where the attacker knows
+ * the state of the pool plus the current outputs, and
+ * attempts to find previous ouputs), unless the hash
+ * function can be inverted.
+ */
+ for (i = 0, x = 0; i < r->poolinfo->poolwords; i += 16, x+=2) {
+ sha_transform(buf, (__u8 *)r->pool+i, buf + 5);
+ add_entropy_words(r, &buf[x % 5], 1);
+ }
- if (r->entropy_count < random_write_wakeup_thresh)
- wake_up_interruptible(&random_write_wait);
+ /*
+ * To avoid duplicates, we atomically extract a
+ * portion of the pool while mixing, and hash one
+ * final time.
+ */
+ __add_entropy_words(r, &buf[x % 5], 1, data);
+ sha_transform(buf, (__u8 *)data, buf + 5);
- DEBUG_ENT("%04d %04d : debiting %d bits from %s%s\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- nbytes * 8,
- r == sec_random_state ? "secondary" :
- r == random_state ? "primary" : "unknown",
- flags & EXTRACT_ENTROPY_LIMIT ? "" : " (unlimited)");
+ /*
+ * In case the hash function has some recognizable
+ * output pattern, we fold it in half.
+ */
- spin_unlock_irqrestore(&r->lock, cpuflags);
+ buf[0] ^= buf[3];
+ buf[1] ^= buf[4];
+ buf[0] ^= rol32(buf[3], 16);
+ memcpy(out, buf, EXTRACT_SIZE);
+ memset(buf, 0, sizeof(buf));
+}
+
+static ssize_t extract_entropy(struct entropy_store *r, void * buf,
+ size_t nbytes, int min, int reserved)
+{
+ ssize_t ret = 0, i;
+ __u8 tmp[EXTRACT_SIZE];
+
+ xfer_secondary_pool(r, nbytes);
+ nbytes = account(r, nbytes, min, reserved);
- ret = 0;
while (nbytes) {
- /*
- * Check if we need to break out or reschedule....
- */
- if ((flags & EXTRACT_ENTROPY_USER) && need_resched()) {
+ extract_buf(r, tmp);
+ i = min_t(int, nbytes, EXTRACT_SIZE);
+ memcpy(buf, tmp, i);
+ nbytes -= i;
+ buf += i;
+ ret += i;
+ }
+
+ /* Wipe data just returned from memory */
+ memset(tmp, 0, sizeof(tmp));
+
+ return ret;
+}
+
+static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf,
+ size_t nbytes)
+{
+ ssize_t ret = 0, i;
+ __u8 tmp[EXTRACT_SIZE];
+
+ xfer_secondary_pool(r, nbytes);
+ nbytes = account(r, nbytes, 0, 0);
+
+ while (nbytes) {
+ if (need_resched()) {
if (signal_pending(current)) {
if (ret == 0)
ret = -ERESTARTSYS;
break;
}
-
- DEBUG_ENT("%04d %04d : extract feeling sleepy (%d bytes left)\n",
- random_state->entropy_count,
- sec_random_state->entropy_count, nbytes);
-
schedule();
-
- DEBUG_ENT("%04d %04d : extract woke up\n",
- random_state->entropy_count,
- sec_random_state->entropy_count);
}
- /* Hash the pool to get the output */
- tmp[0] = 0x67452301;
- tmp[1] = 0xefcdab89;
- tmp[2] = 0x98badcfe;
- tmp[3] = 0x10325476;
-#ifdef USE_SHA
- tmp[4] = 0xc3d2e1f0;
-#endif
- /*
- * As we hash the pool, we mix intermediate values of
- * the hash back into the pool. This eliminates
- * backtracking attacks (where the attacker knows
- * the state of the pool plus the current outputs, and
- * attempts to find previous ouputs), unless the hash
- * function can be inverted.
- */
- for (i = 0, x = 0; i < r->poolinfo.poolwords; i += 16, x+=2) {
- HASH_TRANSFORM(tmp, r->pool+i);
- add_entropy_words(r, &tmp[x%HASH_BUFFER_SIZE], 1);
+ extract_buf(r, tmp);
+ i = min_t(int, nbytes, EXTRACT_SIZE);
+ if (copy_to_user(buf, tmp, i)) {
+ ret = -EFAULT;
+ break;
}
-
- /*
- * In case the hash function has some recognizable
- * output pattern, we fold it in half.
- */
- for (i = 0; i < HASH_BUFFER_SIZE/2; i++)
- tmp[i] ^= tmp[i + (HASH_BUFFER_SIZE+1)/2];
-#if HASH_BUFFER_SIZE & 1 /* There's a middle word to deal with */
- x = tmp[HASH_BUFFER_SIZE/2];
- x ^= (x >> 16); /* Fold it in half */
- ((__u16 *)tmp)[HASH_BUFFER_SIZE-1] = (__u16)x;
-#endif
-
- /* Copy data to destination buffer */
- i = min(nbytes, HASH_BUFFER_SIZE*sizeof(__u32)/2);
- if (flags & EXTRACT_ENTROPY_USER) {
- i -= copy_to_user(buf, (__u8 const *)tmp, i);
- if (!i) {
- ret = -EFAULT;
- break;
- }
- } else
- memcpy(buf, (__u8 const *)tmp, i);
+
nbytes -= i;
buf += i;
ret += i;
/* Wipe data just returned from memory */
memset(tmp, 0, sizeof(tmp));
-
+
return ret;
}
*/
void get_random_bytes(void *buf, int nbytes)
{
- if (sec_random_state)
- extract_entropy(sec_random_state, (char *) buf, nbytes,
- EXTRACT_ENTROPY_SECONDARY);
- else if (random_state)
- extract_entropy(random_state, (char *) buf, nbytes, 0);
- else
- printk(KERN_NOTICE "get_random_bytes called before "
- "random driver initialization\n");
+ extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0);
}
EXPORT_SYMBOL(get_random_bytes);
-/*********************************************************************
- *
- * Functions to interface with Linux
- *
- *********************************************************************/
-
/*
- * Initialize the random pool with standard stuff.
+ * init_std_data - initialize pool with system data
+ *
+ * @r: pool to initialize
*
- * NOTE: This is an OS-dependent function.
+ * This function clears the pool's entropy count and mixes some system
+ * data into the pool to prepare it for use. The pool is not cleared
+ * as that can only decrease the entropy in the pool.
*/
static void init_std_data(struct entropy_store *r)
{
- struct timeval tv;
- __u32 words[2];
- char *p;
- int i;
+ struct timeval tv;
+ unsigned long flags;
- do_gettimeofday(&tv);
- words[0] = tv.tv_sec;
- words[1] = tv.tv_usec;
- add_entropy_words(r, words, 2);
+ spin_lock_irqsave(&r->lock, flags);
+ r->entropy_count = 0;
+ spin_unlock_irqrestore(&r->lock, flags);
- /*
- * This doesn't lock system.utsname. However, we are generating
- * entropy so a race with a name set here is fine.
- */
- p = (char *) &system_utsname;
- for (i = sizeof(system_utsname) / sizeof(words); i; i--) {
- memcpy(words, p, sizeof(words));
- add_entropy_words(r, words, sizeof(words)/4);
- p += sizeof(words);
- }
+ do_gettimeofday(&tv);
+ add_entropy_words(r, (__u32 *)&tv, sizeof(tv)/4);
+ add_entropy_words(r, (__u32 *)utsname(),
+ sizeof(*(utsname()))/4);
}
static int __init rand_initialize(void)
{
- int i;
-
- if (create_entropy_store(DEFAULT_POOL_SIZE, &random_state))
- goto err;
- if (batch_entropy_init(BATCH_ENTROPY_SIZE, random_state))
- goto err;
- if (create_entropy_store(SECONDARY_POOL_SIZE, &sec_random_state))
- goto err;
- clear_entropy_store(random_state);
- clear_entropy_store(sec_random_state);
- init_std_data(random_state);
-#ifdef CONFIG_SYSCTL
- sysctl_init_random(random_state);
-#endif
- for (i = 0; i < NR_IRQS; i++)
- irq_timer_state[i] = NULL;
- memset(&keyboard_timer_state, 0, sizeof(struct timer_rand_state));
- memset(&mouse_timer_state, 0, sizeof(struct timer_rand_state));
- memset(&extract_timer_state, 0, sizeof(struct timer_rand_state));
- extract_timer_state.dont_count_entropy = 1;
+ init_std_data(&input_pool);
+ init_std_data(&blocking_pool);
+ init_std_data(&nonblocking_pool);
return 0;
-err:
- return -1;
}
module_init(rand_initialize);
void rand_initialize_irq(int irq)
{
struct timer_rand_state *state;
-
+
if (irq >= NR_IRQS || irq_timer_state[irq])
return;
irq_timer_state[irq] = state;
}
}
-
+
+#ifdef CONFIG_BLOCK
void rand_initialize_disk(struct gendisk *disk)
{
struct timer_rand_state *state;
-
+
/*
* If kmalloc returns null, we just won't use that entropy
* source.
disk->random = state;
}
}
+#endif
static ssize_t
random_read(struct file * file, char __user * buf, size_t nbytes, loff_t *ppos)
{
- DECLARE_WAITQUEUE(wait, current);
- ssize_t n, retval = 0, count = 0;
-
+ ssize_t n, retval = 0, count = 0;
+
if (nbytes == 0)
return 0;
if (n > SEC_XFER_SIZE)
n = SEC_XFER_SIZE;
- DEBUG_ENT("%04d %04d : reading %d bits, p: %d s: %d\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- n*8, random_state->entropy_count,
- sec_random_state->entropy_count);
+ DEBUG_ENT("reading %d bits\n", n*8);
- n = extract_entropy(sec_random_state, buf, n,
- EXTRACT_ENTROPY_USER |
- EXTRACT_ENTROPY_LIMIT |
- EXTRACT_ENTROPY_SECONDARY);
+ n = extract_entropy_user(&blocking_pool, buf, n);
- DEBUG_ENT("%04d %04d : read got %d bits (%d still needed)\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
+ DEBUG_ENT("read got %d bits (%d still needed)\n",
n*8, (nbytes-n)*8);
if (n == 0) {
retval = -EAGAIN;
break;
}
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
-
- DEBUG_ENT("%04d %04d : sleeping?\n",
- random_state->entropy_count,
- sec_random_state->entropy_count);
- set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&random_read_wait, &wait);
+ DEBUG_ENT("sleeping?\n");
- if (sec_random_state->entropy_count / 8 == 0)
- schedule();
+ wait_event_interruptible(random_read_wait,
+ input_pool.entropy_count >=
+ random_read_wakeup_thresh);
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&random_read_wait, &wait);
+ DEBUG_ENT("awake\n");
- DEBUG_ENT("%04d %04d : waking up\n",
- random_state->entropy_count,
- sec_random_state->entropy_count);
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
continue;
}
*/
if (count)
file_accessed(file);
-
+
return (count ? count : retval);
}
urandom_read(struct file * file, char __user * buf,
size_t nbytes, loff_t *ppos)
{
- return extract_entropy(sec_random_state, buf, nbytes,
- EXTRACT_ENTROPY_USER |
- EXTRACT_ENTROPY_SECONDARY);
+ return extract_entropy_user(&nonblocking_pool, buf, nbytes);
}
static unsigned int
poll_wait(file, &random_read_wait, wait);
poll_wait(file, &random_write_wait, wait);
mask = 0;
- if (random_state->entropy_count >= random_read_wakeup_thresh)
+ if (input_pool.entropy_count >= random_read_wakeup_thresh)
mask |= POLLIN | POLLRDNORM;
- if (random_state->entropy_count < random_write_wakeup_thresh)
+ if (input_pool.entropy_count < random_write_wakeup_thresh)
mask |= POLLOUT | POLLWRNORM;
return mask;
}
random_write(struct file * file, const char __user * buffer,
size_t count, loff_t *ppos)
{
- int ret = 0;
- size_t bytes;
- __u32 buf[16];
- const char __user *p = buffer;
- size_t c = count;
+ int ret = 0;
+ size_t bytes;
+ __u32 buf[16];
+ const char __user *p = buffer;
+ size_t c = count;
while (c > 0) {
bytes = min(c, sizeof(buf));
c -= bytes;
p += bytes;
- add_entropy_words(random_state, buf, (bytes + 3) / 4);
+ add_entropy_words(&input_pool, buf, (bytes + 3) / 4);
}
if (p == buffer) {
return (ssize_t)ret;
} else {
- file->f_dentry->d_inode->i_mtime = CURRENT_TIME;
- mark_inode_dirty(file->f_dentry->d_inode);
+ struct inode *inode = file->f_path.dentry->d_inode;
+ inode->i_mtime = current_fs_time(inode->i_sb);
+ mark_inode_dirty(inode);
return (ssize_t)(p - buffer);
}
}
random_ioctl(struct inode * inode, struct file * file,
unsigned int cmd, unsigned long arg)
{
- int *tmp, size, ent_count;
+ int size, ent_count;
int __user *p = (int __user *)arg;
int retval;
- unsigned long flags;
-
+
switch (cmd) {
case RNDGETENTCNT:
- ent_count = random_state->entropy_count;
+ ent_count = input_pool.entropy_count;
if (put_user(ent_count, p))
return -EFAULT;
return 0;
return -EPERM;
if (get_user(ent_count, p))
return -EFAULT;
- credit_entropy_store(random_state, ent_count);
+ credit_entropy_store(&input_pool, ent_count);
/*
* Wake up waiting processes if we have enough
* entropy.
*/
- if (random_state->entropy_count >= random_read_wakeup_thresh)
+ if (input_pool.entropy_count >= random_read_wakeup_thresh)
wake_up_interruptible(&random_read_wait);
return 0;
- case RNDGETPOOL:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- if (get_user(size, p) ||
- put_user(random_state->poolinfo.poolwords, p++))
- return -EFAULT;
- if (size < 0)
- return -EFAULT;
- if (size > random_state->poolinfo.poolwords)
- size = random_state->poolinfo.poolwords;
-
- /* prepare to atomically snapshot pool */
-
- tmp = kmalloc(size * sizeof(__u32), GFP_KERNEL);
-
- if (!tmp)
- return -ENOMEM;
-
- spin_lock_irqsave(&random_state->lock, flags);
- ent_count = random_state->entropy_count;
- memcpy(tmp, random_state->pool, size * sizeof(__u32));
- spin_unlock_irqrestore(&random_state->lock, flags);
-
- if (!copy_to_user(p, tmp, size * sizeof(__u32))) {
- kfree(tmp);
- return -EFAULT;
- }
-
- kfree(tmp);
-
- if(put_user(ent_count, p++))
- return -EFAULT;
-
- return 0;
case RNDADDENTROPY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
size, &file->f_pos);
if (retval < 0)
return retval;
- credit_entropy_store(random_state, ent_count);
+ credit_entropy_store(&input_pool, ent_count);
/*
* Wake up waiting processes if we have enough
* entropy.
*/
- if (random_state->entropy_count >= random_read_wakeup_thresh)
+ if (input_pool.entropy_count >= random_read_wakeup_thresh)
wake_up_interruptible(&random_read_wait);
return 0;
case RNDZAPENTCNT:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- random_state->entropy_count = 0;
- return 0;
case RNDCLEARPOOL:
- /* Clear the entropy pool and associated counters. */
+ /* Clear the entropy pool counters. */
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- clear_entropy_store(random_state);
- init_std_data(random_state);
+ init_std_data(&input_pool);
+ init_std_data(&blocking_pool);
+ init_std_data(&nonblocking_pool);
return 0;
default:
return -EINVAL;
}
struct file_operations random_fops = {
- .read = random_read,
- .write = random_write,
- .poll = random_poll,
- .ioctl = random_ioctl,
+ .read = random_read,
+ .write = random_write,
+ .poll = random_poll,
+ .ioctl = random_ioctl,
};
struct file_operations urandom_fops = {
- .read = urandom_read,
- .write = random_write,
- .ioctl = random_ioctl,
+ .read = urandom_read,
+ .write = random_write,
+ .ioctl = random_ioctl,
};
/***************************************************************
* Random UUID interface
- *
- * Used here for a Boot ID, but can be useful for other kernel
+ *
+ * Used here for a Boot ID, but can be useful for other kernel
* drivers.
***************************************************************/
#include <linux/sysctl.h>
-static int sysctl_poolsize;
-static int min_read_thresh, max_read_thresh;
-static int min_write_thresh, max_write_thresh;
+static int min_read_thresh = 8, min_write_thresh;
+static int max_read_thresh = INPUT_POOL_WORDS * 32;
+static int max_write_thresh = INPUT_POOL_WORDS * 32;
static char sysctl_bootid[16];
-/*
- * This function handles a request from the user to change the pool size
- * of the primary entropy store.
- */
-static int change_poolsize(int poolsize)
-{
- struct entropy_store *new_store, *old_store;
- int ret;
-
- if ((ret = create_entropy_store(poolsize, &new_store)))
- return ret;
-
- add_entropy_words(new_store, random_state->pool,
- random_state->poolinfo.poolwords);
- credit_entropy_store(new_store, random_state->entropy_count);
-
- sysctl_init_random(new_store);
- old_store = random_state;
- random_state = batch_work.data = new_store;
- free_entropy_store(old_store);
- return 0;
-}
-
-static int proc_do_poolsize(ctl_table *table, int write, struct file *filp,
- void __user *buffer, size_t *lenp)
-{
- int ret;
-
- sysctl_poolsize = random_state->poolinfo.POOLBYTES;
-
- ret = proc_dointvec(table, write, filp, buffer, lenp);
- if (ret || !write ||
- (sysctl_poolsize == random_state->poolinfo.POOLBYTES))
- return ret;
-
- return change_poolsize(sysctl_poolsize);
-}
-
-static int poolsize_strategy(ctl_table *table, int __user *name, int nlen,
- void __user *oldval, size_t __user *oldlenp,
- void __user *newval, size_t newlen, void **context)
-{
- int len;
-
- sysctl_poolsize = random_state->poolinfo.POOLBYTES;
-
- /*
- * We only handle the write case, since the read case gets
- * handled by the default handler (and we don't care if the
- * write case happens twice; it's harmless).
- */
- if (newval && newlen) {
- len = newlen;
- if (len > table->maxlen)
- len = table->maxlen;
- if (copy_from_user(table->data, newval, len))
- return -EFAULT;
- }
-
- if (sysctl_poolsize != random_state->poolinfo.POOLBYTES)
- return change_poolsize(sysctl_poolsize);
-
- return 0;
-}
-
/*
* These functions is used to return both the bootid UUID, and random
* UUID. The difference is in whether table->data is NULL; if it is,
* then a new UUID is generated and returned to the user.
- *
+ *
* If the user accesses this via the proc interface, it will be returned
- * as an ASCII string in the standard UUID format. If accesses via the
+ * as an ASCII string in the standard UUID format. If accesses via the
* sysctl system call, it is returned as 16 bytes of binary data.
*/
static int proc_do_uuid(ctl_table *table, int write, struct file *filp,
- void __user *buffer, size_t *lenp)
+ void __user *buffer, size_t *lenp, loff_t *ppos)
{
- ctl_table fake_table;
- unsigned char buf[64], tmp_uuid[16], *uuid;
+ ctl_table fake_table;
+ unsigned char buf[64], tmp_uuid[16], *uuid;
uuid = table->data;
if (!uuid) {
fake_table.data = buf;
fake_table.maxlen = sizeof(buf);
- return proc_dostring(&fake_table, write, filp, buffer, lenp);
+ return proc_dostring(&fake_table, write, filp, buffer, lenp, ppos);
}
static int uuid_strategy(ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
- void __user *newval, size_t newlen, void **context)
+ void __user *newval, size_t newlen)
{
- unsigned char tmp_uuid[16], *uuid;
- unsigned int len;
+ unsigned char tmp_uuid[16], *uuid;
+ unsigned int len;
if (!oldval || !oldlenp)
return 1;
return 1;
}
+static int sysctl_poolsize = INPUT_POOL_WORDS * 32;
ctl_table random_table[] = {
{
- .ctl_name = RANDOM_POOLSIZE,
+ .ctl_name = RANDOM_POOLSIZE,
.procname = "poolsize",
.data = &sysctl_poolsize,
.maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_do_poolsize,
- .strategy = &poolsize_strategy,
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
},
{
.ctl_name = RANDOM_ENTROPY_COUNT,
.maxlen = sizeof(int),
.mode = 0444,
.proc_handler = &proc_dointvec,
+ .data = &input_pool.entropy_count,
},
{
.ctl_name = RANDOM_READ_THRESH,
},
{ .ctl_name = 0 }
};
-
-static void sysctl_init_random(struct entropy_store *random_state)
-{
- min_read_thresh = 8;
- min_write_thresh = 0;
- max_read_thresh = max_write_thresh = random_state->poolinfo.POOLBITS;
- random_table[1].data = &random_state->entropy_count;
-}
#endif /* CONFIG_SYSCTL */
/********************************************************************
* Rotation is separate from addition to prevent recomputation
*/
#define ROUND(f, a, b, c, d, x, s) \
- (a += f(b, c, d) + x, a = (a << s) | (a >> (32-s)))
+ (a += f(b, c, d) + x, a = (a << s) | (a >> (32 - s)))
#define K1 0
#define K2 013240474631UL
#define K3 015666365641UL
-/*
- * Basic cut-down MD4 transform. Returns only 32 bits of result.
- */
-static __u32 halfMD4Transform (__u32 const buf[4], __u32 const in[8])
-{
- __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
-
- /* Round 1 */
- ROUND(F, a, b, c, d, in[0] + K1, 3);
- ROUND(F, d, a, b, c, in[1] + K1, 7);
- ROUND(F, c, d, a, b, in[2] + K1, 11);
- ROUND(F, b, c, d, a, in[3] + K1, 19);
- ROUND(F, a, b, c, d, in[4] + K1, 3);
- ROUND(F, d, a, b, c, in[5] + K1, 7);
- ROUND(F, c, d, a, b, in[6] + K1, 11);
- ROUND(F, b, c, d, a, in[7] + K1, 19);
-
- /* Round 2 */
- ROUND(G, a, b, c, d, in[1] + K2, 3);
- ROUND(G, d, a, b, c, in[3] + K2, 5);
- ROUND(G, c, d, a, b, in[5] + K2, 9);
- ROUND(G, b, c, d, a, in[7] + K2, 13);
- ROUND(G, a, b, c, d, in[0] + K2, 3);
- ROUND(G, d, a, b, c, in[2] + K2, 5);
- ROUND(G, c, d, a, b, in[4] + K2, 9);
- ROUND(G, b, c, d, a, in[6] + K2, 13);
-
- /* Round 3 */
- ROUND(H, a, b, c, d, in[3] + K3, 3);
- ROUND(H, d, a, b, c, in[7] + K3, 9);
- ROUND(H, c, d, a, b, in[2] + K3, 11);
- ROUND(H, b, c, d, a, in[6] + K3, 15);
- ROUND(H, a, b, c, d, in[1] + K3, 3);
- ROUND(H, d, a, b, c, in[5] + K3, 9);
- ROUND(H, c, d, a, b, in[0] + K3, 11);
- ROUND(H, b, c, d, a, in[4] + K3, 15);
-
- return buf[1] + b; /* "most hashed" word */
- /* Alternative: return sum of all words? */
-}
-
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static __u32 twothirdsMD4Transform (__u32 const buf[4], __u32 const in[12])
{
- __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
+ __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
/* Round 1 */
ROUND(F, a, b, c, d, in[ 0] + K1, 3);
ROUND(H, c, d, a, b, in[ 4] + K3, 11);
ROUND(H, b, c, d, a, in[ 8] + K3, 15);
- return buf[1] + b; /* "most hashed" word */
+ return buf[1] + b; /* "most hashed" word */
/* Alternative: return sum of all words? */
}
#endif
#undef K3
/* This should not be decreased so low that ISNs wrap too fast. */
-#define REKEY_INTERVAL 300
+#define REKEY_INTERVAL (300 * HZ)
/*
* Bit layout of the tcp sequence numbers (before adding current time):
* bit 24-31: increased after every key exchange
*
* SMP cleanup and lock avoidance with poor man's RCU.
* Manfred Spraul <manfred@colorfullife.com>
- *
+ *
*/
-#define COUNT_BITS 8
-#define COUNT_MASK ( (1<<COUNT_BITS)-1)
-#define HASH_BITS 24
-#define HASH_MASK ( (1<<HASH_BITS)-1 )
+#define COUNT_BITS 8
+#define COUNT_MASK ((1 << COUNT_BITS) - 1)
+#define HASH_BITS 24
+#define HASH_MASK ((1 << HASH_BITS) - 1)
static struct keydata {
- time_t rekey_time;
- __u32 count; // already shifted to the final position
- __u32 secret[12];
+ __u32 count; /* already shifted to the final position */
+ __u32 secret[12];
} ____cacheline_aligned ip_keydata[2];
-static spinlock_t ip_lock = SPIN_LOCK_UNLOCKED;
static unsigned int ip_cnt;
-static struct keydata *__check_and_rekey(time_t time)
+static void rekey_seq_generator(struct work_struct *work);
+
+static DECLARE_DELAYED_WORK(rekey_work, rekey_seq_generator);
+
+/*
+ * Lock avoidance:
+ * The ISN generation runs lockless - it's just a hash over random data.
+ * State changes happen every 5 minutes when the random key is replaced.
+ * Synchronization is performed by having two copies of the hash function
+ * state and rekey_seq_generator always updates the inactive copy.
+ * The copy is then activated by updating ip_cnt.
+ * The implementation breaks down if someone blocks the thread
+ * that processes SYN requests for more than 5 minutes. Should never
+ * happen, and even if that happens only a not perfectly compliant
+ * ISN is generated, nothing fatal.
+ */
+static void rekey_seq_generator(struct work_struct *work)
{
- struct keydata *keyptr;
- spin_lock_bh(&ip_lock);
- keyptr = &ip_keydata[ip_cnt&1];
- if (!keyptr->rekey_time || (time - keyptr->rekey_time) > REKEY_INTERVAL) {
- keyptr = &ip_keydata[1^(ip_cnt&1)];
- keyptr->rekey_time = time;
- get_random_bytes(keyptr->secret, sizeof(keyptr->secret));
- keyptr->count = (ip_cnt&COUNT_MASK)<<HASH_BITS;
- mb();
- ip_cnt++;
- }
- spin_unlock_bh(&ip_lock);
- return keyptr;
+ struct keydata *keyptr = &ip_keydata[1 ^ (ip_cnt & 1)];
+
+ get_random_bytes(keyptr->secret, sizeof(keyptr->secret));
+ keyptr->count = (ip_cnt & COUNT_MASK) << HASH_BITS;
+ smp_wmb();
+ ip_cnt++;
+ schedule_delayed_work(&rekey_work, REKEY_INTERVAL);
}
-static inline struct keydata *check_and_rekey(time_t time)
+static inline struct keydata *get_keyptr(void)
{
- struct keydata *keyptr = &ip_keydata[ip_cnt&1];
+ struct keydata *keyptr = &ip_keydata[ip_cnt & 1];
- rmb();
- if (!keyptr->rekey_time || (time - keyptr->rekey_time) > REKEY_INTERVAL) {
- keyptr = __check_and_rekey(time);
- }
+ smp_rmb();
return keyptr;
}
+static __init int seqgen_init(void)
+{
+ rekey_seq_generator(NULL);
+ return 0;
+}
+late_initcall(seqgen_init);
+
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-__u32 secure_tcpv6_sequence_number(__u32 *saddr, __u32 *daddr,
- __u16 sport, __u16 dport)
+__u32 secure_tcpv6_sequence_number(__be32 *saddr, __be32 *daddr,
+ __be16 sport, __be16 dport)
{
- struct timeval tv;
- __u32 seq;
- __u32 hash[12];
- struct keydata *keyptr;
+ struct timeval tv;
+ __u32 seq;
+ __u32 hash[12];
+ struct keydata *keyptr = get_keyptr();
/* The procedure is the same as for IPv4, but addresses are longer.
* Thus we must use twothirdsMD4Transform.
*/
- do_gettimeofday(&tv); /* We need the usecs below... */
- keyptr = check_and_rekey(tv.tv_sec);
-
memcpy(hash, saddr, 16);
- hash[4]=(sport << 16) + dport;
- memcpy(&hash[5],keyptr->secret,sizeof(__u32)*7);
+ hash[4]=((__force u16)sport << 16) + (__force u16)dport;
+ memcpy(&hash[5],keyptr->secret,sizeof(__u32) * 7);
- seq = twothirdsMD4Transform(daddr, hash) & HASH_MASK;
+ seq = twothirdsMD4Transform((const __u32 *)daddr, hash) & HASH_MASK;
seq += keyptr->count;
- seq += tv.tv_usec + tv.tv_sec*1000000;
+
+ do_gettimeofday(&tv);
+ seq += tv.tv_usec + tv.tv_sec * 1000000;
return seq;
}
EXPORT_SYMBOL(secure_tcpv6_sequence_number);
+#endif
-__u32 secure_ipv6_id(__u32 *daddr)
+/* The code below is shamelessly stolen from secure_tcp_sequence_number().
+ * All blames to Andrey V. Savochkin <saw@msu.ru>.
+ */
+__u32 secure_ip_id(__be32 daddr)
{
struct keydata *keyptr;
+ __u32 hash[4];
- keyptr = check_and_rekey(get_seconds());
+ keyptr = get_keyptr();
- return halfMD4Transform(daddr, keyptr->secret);
-}
+ /*
+ * Pick a unique starting offset for each IP destination.
+ * The dest ip address is placed in the starting vector,
+ * which is then hashed with random data.
+ */
+ hash[0] = (__force __u32)daddr;
+ hash[1] = keyptr->secret[9];
+ hash[2] = keyptr->secret[10];
+ hash[3] = keyptr->secret[11];
-EXPORT_SYMBOL(secure_ipv6_id);
-#endif
+ return half_md4_transform(hash, keyptr->secret);
+}
+#ifdef CONFIG_INET
-__u32 secure_tcp_sequence_number(__u32 saddr, __u32 daddr,
- __u16 sport, __u16 dport)
+__u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
+ __be16 sport, __be16 dport)
{
- struct timeval tv;
- __u32 seq;
- __u32 hash[4];
- struct keydata *keyptr;
-
- /*
- * Pick a random secret every REKEY_INTERVAL seconds.
- */
- do_gettimeofday(&tv); /* We need the usecs below... */
- keyptr = check_and_rekey(tv.tv_sec);
+ struct timeval tv;
+ __u32 seq;
+ __u32 hash[4];
+ struct keydata *keyptr = get_keyptr();
/*
* Pick a unique starting offset for each TCP connection endpoints
* (saddr, daddr, sport, dport).
- * Note that the words are placed into the starting vector, which is
+ * Note that the words are placed into the starting vector, which is
* then mixed with a partial MD4 over random data.
*/
- hash[0]=saddr;
- hash[1]=daddr;
- hash[2]=(sport << 16) + dport;
+ hash[0]=(__force u32)saddr;
+ hash[1]=(__force u32)daddr;
+ hash[2]=((__force u16)sport << 16) + (__force u16)dport;
hash[3]=keyptr->secret[11];
- seq = halfMD4Transform(hash, keyptr->secret) & HASH_MASK;
+ seq = half_md4_transform(hash, keyptr->secret) & HASH_MASK;
seq += keyptr->count;
/*
* As close as possible to RFC 793, which
* That's funny, Linux has one built in! Use it!
* (Networks are faster now - should this be increased?)
*/
- seq += tv.tv_usec + tv.tv_sec*1000000;
+ do_gettimeofday(&tv);
+ seq += tv.tv_usec + tv.tv_sec * 1000000;
#if 0
printk("init_seq(%lx, %lx, %d, %d) = %d\n",
saddr, daddr, sport, dport, seq);
EXPORT_SYMBOL(secure_tcp_sequence_number);
-/* The code below is shamelessly stolen from secure_tcp_sequence_number().
- * All blames to Andrey V. Savochkin <saw@msu.ru>.
- */
-__u32 secure_ip_id(__u32 daddr)
+/* Generate secure starting point for ephemeral IPV4 transport port search */
+u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
{
- struct keydata *keyptr;
- __u32 hash[4];
-
- keyptr = check_and_rekey(get_seconds());
+ struct keydata *keyptr = get_keyptr();
+ u32 hash[4];
/*
- * Pick a unique starting offset for each IP destination.
- * The dest ip address is placed in the starting vector,
- * which is then hashed with random data.
+ * Pick a unique starting offset for each ephemeral port search
+ * (saddr, daddr, dport) and 48bits of random data.
*/
- hash[0] = daddr;
- hash[1] = keyptr->secret[9];
- hash[2] = keyptr->secret[10];
+ hash[0] = (__force u32)saddr;
+ hash[1] = (__force u32)daddr;
+ hash[2] = (__force u32)dport ^ keyptr->secret[10];
hash[3] = keyptr->secret[11];
- return halfMD4Transform(hash, keyptr->secret);
+ return half_md4_transform(hash, keyptr->secret);
}
-#ifdef CONFIG_SYN_COOKIES
-/*
- * Secure SYN cookie computation. This is the algorithm worked out by
- * Dan Bernstein and Eric Schenk.
- *
- * For linux I implement the 1 minute counter by looking at the jiffies clock.
- * The count is passed in as a parameter, so this code doesn't much care.
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, __be16 dport)
+{
+ struct keydata *keyptr = get_keyptr();
+ u32 hash[12];
+
+ memcpy(hash, saddr, 16);
+ hash[4] = (__force u32)dport;
+ memcpy(&hash[5],keyptr->secret,sizeof(__u32) * 7);
+
+ return twothirdsMD4Transform((const __u32 *)daddr, hash);
+}
+#endif
+
+#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
+/* Similar to secure_tcp_sequence_number but generate a 48 bit value
+ * bit's 32-47 increase every key exchange
+ * 0-31 hash(source, dest)
*/
+u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
+ __be16 sport, __be16 dport)
+{
+ struct timeval tv;
+ u64 seq;
+ __u32 hash[4];
+ struct keydata *keyptr = get_keyptr();
+
+ hash[0] = (__force u32)saddr;
+ hash[1] = (__force u32)daddr;
+ hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
+ hash[3] = keyptr->secret[11];
+
+ seq = half_md4_transform(hash, keyptr->secret);
+ seq |= ((u64)keyptr->count) << (32 - HASH_BITS);
+
+ do_gettimeofday(&tv);
+ seq += tv.tv_usec + tv.tv_sec * 1000000;
+ seq &= (1ull << 48) - 1;
+#if 0
+ printk("dccp init_seq(%lx, %lx, %d, %d) = %d\n",
+ saddr, daddr, sport, dport, seq);
+#endif
+ return seq;
+}
+
+EXPORT_SYMBOL(secure_dccp_sequence_number);
+#endif
-#define COOKIEBITS 24 /* Upper bits store count */
-#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
+#endif /* CONFIG_INET */
-static int syncookie_init;
-static __u32 syncookie_secret[2][16-3+HASH_BUFFER_SIZE];
-__u32 secure_tcp_syn_cookie(__u32 saddr, __u32 daddr, __u16 sport,
- __u16 dport, __u32 sseq, __u32 count, __u32 data)
+/*
+ * Get a random word for internal kernel use only. Similar to urandom but
+ * with the goal of minimal entropy pool depletion. As a result, the random
+ * value is not cryptographically secure but for several uses the cost of
+ * depleting entropy is too high
+ */
+unsigned int get_random_int(void)
{
- __u32 tmp[16 + HASH_BUFFER_SIZE + HASH_EXTRA_SIZE];
- __u32 seq;
+ unsigned int val = 0;
- /*
- * Pick two random secrets the first time we need a cookie.
- */
- if (syncookie_init == 0) {
- get_random_bytes(syncookie_secret, sizeof(syncookie_secret));
- syncookie_init = 1;
- }
+#ifdef CONFIG_X86_HAS_TSC
+ rdtscl(val);
+#endif
/*
- * Compute the secure sequence number.
- * The output should be:
- * HASH(sec1,saddr,sport,daddr,dport,sec1) + sseq + (count * 2^24)
- * + (HASH(sec2,saddr,sport,daddr,dport,count,sec2) % 2^24).
- * Where sseq is their sequence number and count increases every
- * minute by 1.
- * As an extra hack, we add a small "data" value that encodes the
- * MSS into the second hash value.
+ * Use IP's RNG. It suits our purpose perfectly: it re-keys itself
+ * every second, from the entropy pool (and thus creates a limited
+ * drain on it), and uses halfMD4Transform within the second. We
+ * also mix it with jiffies and the PID:
*/
-
- memcpy(tmp+3, syncookie_secret[0], sizeof(syncookie_secret[0]));
- tmp[0]=saddr;
- tmp[1]=daddr;
- tmp[2]=(sport << 16) + dport;
- HASH_TRANSFORM(tmp+16, tmp);
- seq = tmp[17] + sseq + (count << COOKIEBITS);
-
- memcpy(tmp+3, syncookie_secret[1], sizeof(syncookie_secret[1]));
- tmp[0]=saddr;
- tmp[1]=daddr;
- tmp[2]=(sport << 16) + dport;
- tmp[3] = count; /* minute counter */
- HASH_TRANSFORM(tmp+16, tmp);
-
- /* Add in the second hash and the data */
- return seq + ((tmp[17] + data) & COOKIEMASK);
+ return secure_ip_id((__force __be32)(current->pid + jiffies + (int)val));
}
/*
- * This retrieves the small "data" value from the syncookie.
- * If the syncookie is bad, the data returned will be out of
- * range. This must be checked by the caller.
+ * randomize_range() returns a start address such that
+ *
+ * [...... <range> .....]
+ * start end
*
- * The count value used to generate the cookie must be within
- * "maxdiff" if the current (passed-in) "count". The return value
- * is (__u32)-1 if this test fails.
+ * a <range> with size "len" starting at the return value is inside in the
+ * area defined by [start, end], but is otherwise randomized.
*/
-__u32 check_tcp_syn_cookie(__u32 cookie, __u32 saddr, __u32 daddr, __u16 sport,
- __u16 dport, __u32 sseq, __u32 count, __u32 maxdiff)
+unsigned long
+randomize_range(unsigned long start, unsigned long end, unsigned long len)
{
- __u32 tmp[16 + HASH_BUFFER_SIZE + HASH_EXTRA_SIZE];
- __u32 diff;
-
- if (syncookie_init == 0)
- return (__u32)-1; /* Well, duh! */
-
- /* Strip away the layers from the cookie */
- memcpy(tmp+3, syncookie_secret[0], sizeof(syncookie_secret[0]));
- tmp[0]=saddr;
- tmp[1]=daddr;
- tmp[2]=(sport << 16) + dport;
- HASH_TRANSFORM(tmp+16, tmp);
- cookie -= tmp[17] + sseq;
- /* Cookie is now reduced to (count * 2^24) ^ (hash % 2^24) */
-
- diff = (count - (cookie >> COOKIEBITS)) & ((__u32)-1 >> COOKIEBITS);
- if (diff >= maxdiff)
- return (__u32)-1;
-
- memcpy(tmp+3, syncookie_secret[1], sizeof(syncookie_secret[1]));
- tmp[0] = saddr;
- tmp[1] = daddr;
- tmp[2] = (sport << 16) + dport;
- tmp[3] = count - diff; /* minute counter */
- HASH_TRANSFORM(tmp+16, tmp);
-
- return (cookie - tmp[17]) & COOKIEMASK; /* Leaving the data behind */
+ unsigned long range = end - len - start;
+
+ if (end <= start + len)
+ return 0;
+ return PAGE_ALIGN(get_random_int() % range + start);
}
-#endif
git://git.onelab.eu / linux-2.6.git / blobdiff