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Random number generator

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This commit is contained in:
Philip Homburg
2005-07-18 15:40:24 +00:00
parent 3eb405c3bf
commit 7d4e914618
20 changed files with 3739 additions and 36 deletions
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50
drivers/memory/memory.c
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@@ -23,6 +23,9 @@
#include "../../kernel/config.h"
#include "../../kernel/type.h"
#include "assert.h"
#include "random.h"
#define NR_DEVS 7 /* number of minor devices */
#define KRANDOM_PERIOD 10 /* ticks between krandom calls */
@@ -69,7 +72,7 @@ PRIVATE char dev_zero[ZERO_BUF_SIZE];
/* Buffer for the /dev/random number generator. */
#define RANDOM_BUF_SIZE 1024
PRIVATE char dev_random[RANDOM_BUF_SIZE];
PRIVATE char random_buf[RANDOM_BUF_SIZE];
#define click_to_round_k(n) \
@@ -180,15 +183,23 @@ unsigned nr_req; /* length of request vector */
/* Random number generator. Character instead of block device. */
case RANDOM_DEV:
if (opcode == DEV_GATHER)
{
s= random_reseed();
if (s < 0)
return(EAGAIN);
}
left = count;
while (left > 0) {
chunk = (left > RANDOM_BUF_SIZE) ? RANDOM_BUF_SIZE : left;
if (opcode == DEV_GATHER) {
sys_vircopy(SELF, D, (vir_bytes) dev_random,
random_getbytes(random_buf, chunk);
sys_vircopy(SELF, D, (vir_bytes) random_buf,
proc_nr, D, user_vir, chunk);
} else if (opcode == DEV_SCATTER) {
sys_vircopy(proc_nr, D, user_vir,
SELF, D, (vir_bytes) dev_random, chunk);
SELF, D, (vir_bytes) random_buf, chunk);
random_putbytes(random_buf, chunk);
}
left -= chunk;
}
@@ -275,10 +286,7 @@ PRIVATE void m_init()
dev_zero[i] = '\0';
}
/* Initialize /dev/random. Seed the buffer and get kernel randomness. */
for (i=0; i<RANDOM_BUF_SIZE; i++) {
dev_random[i] = 'a' + i % 256; /* from file in future !!! */
}
random_init();
m_random(NULL); /* also set periodic timer */
/* Set up memory ranges for /dev/mem. */
@@ -364,19 +372,29 @@ PRIVATE void m_random(dp)
struct driver *dp; /* pointer to driver structure */
{
/* Fetch random information from the kernel to update /dev/random. */
int i, s, r_next, r_size, r_high;
struct randomness krandom;
static unsigned long *next_ptr = (unsigned long *) &dev_random[0];
int i,s;
if (OK != (s=sys_getrandomness(&krandom)))
report("MEM", "sys_getrandomness failed", s);
i= (krandom.r_next + RANDOM_ELEMENTS -1) % RANDOM_ELEMENTS;
while (krandom.r_size -- > 0) {
*next_ptr = krandom.r_buf[i]; /* set dev_random data */
next_ptr ++; /* proceed to next */
if ((next_ptr - (unsigned long *) &dev_random[RANDOM_BUF_SIZE-1]) >=
RANDOM_ELEMENTS) next_ptr = (unsigned long *) &dev_random[0];
i = (i + 1) % RANDOM_ELEMENTS; /* next kernel random data */
for (i= 0; i<RANDOM_SOURCES; i++)
{
r_next= krandom.bin[i].r_next;
r_size= krandom.bin[i].r_size;
r_high= r_next+r_size;
if (r_high <= RANDOM_ELEMENTS)
{
random_update(i, &krandom.bin[i].r_buf[r_next], r_size);
}
else
{
assert(r_next < RANDOM_ELEMENTS);
random_update(i, &krandom.bin[i].r_buf[r_next],
RANDOM_ELEMENTS-r_next);
random_update(i, &krandom.bin[i].r_buf[0],
r_high-RANDOM_ELEMENTS);
}
}
/* Schedule new alarm for next m_random call. */