#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/interrupt.h>
+#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/percpu.h>
#include <linux/cryptohash.h>
*/
static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
+static struct fasync_struct *fasync;
#if 0
static int debug;
struct entropy_store;
struct entropy_store {
- /* mostly-read data: */
+ /* read-only data: */
struct poolinfo *poolinfo;
__u32 *pool;
const char *name;
struct entropy_store *pull;
/* read-write data: */
- spinlock_t lock ____cacheline_aligned_in_smp;
+ spinlock_t lock;
unsigned add_ptr;
- int entropy_count;
+ int entropy_count; /* Must at no time exceed ->POOLBITS! */
int input_rotate;
};
};
/*
- * This function adds a byte into the entropy "pool". It does not
+ * This function adds bytes into the entropy "pool". It does not
* update the entropy estimate. The caller should call
- * credit_entropy_store if this is appropriate.
+ * credit_entropy_bits 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, __u32 out[16])
+static void mix_pool_bytes_extract(struct entropy_store *r, const void *in,
+ int nbytes, __u8 out[64])
{
static __u32 const twist_table[8] = {
0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
- unsigned long i, add_ptr, tap1, tap2, tap3, tap4, tap5;
- int new_rotate, input_rotate;
+ unsigned long i, j, tap1, tap2, tap3, tap4, tap5;
+ int input_rotate;
int wordmask = r->poolinfo->poolwords - 1;
- __u32 w, next_w;
+ const char *bytes = in;
+ __u32 w;
unsigned long flags;
/* Taps are constant, so we can load them without holding r->lock. */
tap3 = r->poolinfo->tap3;
tap4 = r->poolinfo->tap4;
tap5 = r->poolinfo->tap5;
- next_w = *in++;
spin_lock_irqsave(&r->lock, flags);
- prefetch_range(r->pool, wordmask);
input_rotate = r->input_rotate;
- add_ptr = r->add_ptr;
+ i = r->add_ptr;
- while (nwords--) {
- w = rol32(next_w, input_rotate);
- if (nwords > 0)
- next_w = *in++;
- i = add_ptr = (add_ptr - 1) & wordmask;
- /*
- * Normally, we add 7 bits of rotation to the pool.
- * At the beginning of the pool, add an extra 7 bits
- * rotation, so that successive passes spread the
- * input bits across the pool evenly.
- */
- new_rotate = input_rotate + 14;
- if (i)
- new_rotate = input_rotate + 7;
- input_rotate = new_rotate & 31;
+ /* mix one byte at a time to simplify size handling and churn faster */
+ while (nbytes--) {
+ w = rol32(*bytes++, input_rotate & 31);
+ i = (i - 1) & wordmask;
/* XOR in the various taps */
+ w ^= r->pool[i];
w ^= r->pool[(i + tap1) & wordmask];
w ^= r->pool[(i + tap2) & wordmask];
w ^= r->pool[(i + tap3) & wordmask];
w ^= r->pool[(i + tap4) & wordmask];
w ^= r->pool[(i + tap5) & wordmask];
- w ^= r->pool[i];
+
+ /* Mix the result back in with a twist */
r->pool[i] = (w >> 3) ^ twist_table[w & 7];
+
+ /*
+ * Normally, we add 7 bits of rotation to the pool.
+ * At the beginning of the pool, add an extra 7 bits
+ * rotation, so that successive passes spread the
+ * input bits across the pool evenly.
+ */
+ input_rotate += i ? 7 : 14;
}
r->input_rotate = input_rotate;
- r->add_ptr = add_ptr;
+ r->add_ptr = i;
- if (out) {
- for (i = 0; i < 16; i++) {
- out[i] = r->pool[add_ptr];
- add_ptr = (add_ptr - 1) & wordmask;
- }
- }
+ if (out)
+ for (j = 0; j < 16; j++)
+ ((__u32 *)out)[j] = r->pool[(i - j) & wordmask];
spin_unlock_irqrestore(&r->lock, flags);
}
-static inline void add_entropy_words(struct entropy_store *r, const __u32 *in,
- int nwords)
+static void mix_pool_bytes(struct entropy_store *r, const void *in, int bytes)
{
- __add_entropy_words(r, in, nwords, NULL);
+ mix_pool_bytes_extract(r, in, bytes, NULL);
}
/*
* Credit (or debit) the entropy store with n bits of entropy
*/
-static void credit_entropy_store(struct entropy_store *r, int nbits)
+static void credit_entropy_bits(struct entropy_store *r, int nbits)
{
unsigned long flags;
+ int entropy_count;
+
+ if (!nbits)
+ return;
spin_lock_irqsave(&r->lock, flags);
- if (r->entropy_count + nbits < 0) {
- 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 {
- r->entropy_count += nbits;
- if (nbits)
- DEBUG_ENT("added %d entropy credits to %s\n",
- nbits, r->name);
- }
+ DEBUG_ENT("added %d entropy credits to %s\n", nbits, r->name);
+ entropy_count = r->entropy_count;
+ entropy_count += nbits;
+ if (entropy_count < 0) {
+ DEBUG_ENT("negative entropy/overflow\n");
+ entropy_count = 0;
+ } else if (entropy_count > r->poolinfo->POOLBITS)
+ entropy_count = r->poolinfo->POOLBITS;
+ r->entropy_count = entropy_count;
/* should we wake readers? */
- if (r == &input_pool && r->entropy_count >= random_read_wakeup_thresh)
+ if (r == &input_pool && entropy_count >= random_read_wakeup_thresh) {
wake_up_interruptible(&random_read_wait);
-
+ kill_fasync(&fasync, SIGIO, POLL_IN);
+ }
spin_unlock_irqrestore(&r->lock, flags);
}
sample.jiffies = jiffies;
sample.cycles = get_cycles();
sample.num = num;
- add_entropy_words(&input_pool, (u32 *)&sample, sizeof(sample)/4);
+ mix_pool_bytes(&input_pool, &sample, sizeof(sample));
/*
* Calculate number of bits of randomness we probably added.
* Round down by 1 bit on general principles,
* and limit entropy entimate to 12 bits.
*/
- credit_entropy_store(&input_pool,
- min_t(int, fls(delta>>1), 11));
+ credit_entropy_bits(&input_pool,
+ min_t(int, fls(delta>>1), 11));
}
out:
preempt_enable();
if (!disk || !disk->random)
return;
/* first major is 1, so we get >= 0x200 here */
- DEBUG_ENT("disk event %d:%d\n", disk->major, disk->first_minor);
+ DEBUG_ENT("disk event %d:%d\n",
+ MAJOR(disk_devt(disk)), MINOR(disk_devt(disk)));
- add_timer_randomness(disk->random,
- 0x100 + MKDEV(disk->major, disk->first_minor));
+ add_timer_randomness(disk->random, 0x100 + disk_devt(disk));
}
#endif
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);
+ mix_pool_bytes(r, tmp, bytes);
+ credit_entropy_bits(r, bytes*8);
}
}
else
r->entropy_count = reserved;
- if (r->entropy_count < random_write_wakeup_thresh)
+ if (r->entropy_count < random_write_wakeup_thresh) {
wake_up_interruptible(&random_write_wait);
+ kill_fasync(&fasync, SIGIO, POLL_OUT);
+ }
}
DEBUG_ENT("debiting %d entropy credits from %s%s\n",
static void extract_buf(struct entropy_store *r, __u8 *out)
{
int i;
- __u32 extract[16], hash[5], workspace[SHA_WORKSPACE_WORDS];
+ __u32 hash[5], workspace[SHA_WORKSPACE_WORDS];
+ __u8 extract[64];
/* Generate a hash across the pool, 16 words (512 bits) at a time */
sha_init(hash);
* brute-forcing the feedback as hard as brute-forcing the
* hash.
*/
- __add_entropy_words(r, hash, 5, extract);
+ mix_pool_bytes_extract(r, hash, sizeof(hash), extract);
/*
* To avoid duplicates, we atomically extract a portion of the
* pool while mixing, and hash one final time.
*/
- sha_transform(hash, (__u8 *)extract, workspace);
+ sha_transform(hash, extract, workspace);
memset(extract, 0, sizeof(extract));
memset(workspace, 0, sizeof(workspace));
spin_unlock_irqrestore(&r->lock, flags);
now = ktime_get_real();
- add_entropy_words(r, (__u32 *)&now, sizeof(now)/4);
- add_entropy_words(r, (__u32 *)utsname(),
- sizeof(*(utsname()))/4);
+ mix_pool_bytes(r, &now, sizeof(now));
+ mix_pool_bytes(r, utsname(), sizeof(*(utsname())));
}
static int rand_initialize(void)
count -= bytes;
p += bytes;
- add_entropy_words(r, buf, (bytes + 3) / 4);
+ mix_pool_bytes(r, buf, bytes);
cond_resched();
}
return -EPERM;
if (get_user(ent_count, p))
return -EFAULT;
- credit_entropy_store(&input_pool, ent_count);
+ credit_entropy_bits(&input_pool, ent_count);
return 0;
case RNDADDENTROPY:
if (!capable(CAP_SYS_ADMIN))
size);
if (retval < 0)
return retval;
- credit_entropy_store(&input_pool, ent_count);
+ credit_entropy_bits(&input_pool, ent_count);
return 0;
case RNDZAPENTCNT:
case RNDCLEARPOOL:
}
}
+static int random_fasync(int fd, struct file *filp, int on)
+{
+ return fasync_helper(fd, filp, on, &fasync);
+}
+
+static int random_release(struct inode *inode, struct file *filp)
+{
+ return fasync_helper(-1, filp, 0, &fasync);
+}
+
const struct file_operations random_fops = {
.read = random_read,
.write = random_write,
.poll = random_poll,
.unlocked_ioctl = random_ioctl,
+ .fasync = random_fasync,
+ .release = random_release,
};
const struct file_operations urandom_fops = {
.read = urandom_read,
.write = random_write,
.unlocked_ioctl = random_ioctl,
+ .fasync = random_fasync,
+ .release = random_release,
};
/***************************************************************
return half_md4_transform(hash, keyptr->secret);
}
+EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff