#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <miscfs/devfs/devfs.h>
#include <kern/lock.h>
#include <sys/time.h>
#include <sys/malloc.h>
#include <dev/random/randomdev.h>
#include <dev/random/YarrowCoreLib/include/yarrow.h>
#define RANDOM_MAJOR -1
d_ioctl_t random_ioctl;
static struct cdevsw random_cdevsw =
{
random_open,
random_close,
random_read,
random_write,
random_ioctl,
nulldev,
nulldev,
NULL,
eno_select,
eno_mmap,
eno_strat,
eno_getc,
eno_putc,
0
};
static int gRandomInstalled = 0;
static PrngRef gPrngRef;
static int gRandomError = 1;
static mutex_t *gYarrowMutex = 0;
#define RESEED_TICKS 50
void PreliminarySetup ()
{
prng_error_status perr;
struct timeval tt;
char buffer [16];
perr = prngInitialize(&gPrngRef);
if (perr != 0) {
printf ("Couldn't initialize Yarrow, /dev/random will not work.\n");
return;
}
gRandomError = 0;
microtime(&tt);
perr = prngInput(gPrngRef, (BYTE*) &tt, sizeof (tt), SYSTEM_SOURCE, 8);
if (perr != 0) {
printf ("Couldn't seed Yarrow.\n");
return;
}
perr = prngOutput(gPrngRef, (BYTE*) buffer, sizeof (buffer));
perr = prngForceReseed(gPrngRef, RESEED_TICKS);
gYarrowMutex = mutex_alloc(0);
}
void
random_init()
{
int ret;
if (gRandomInstalled)
return;
gRandomInstalled = 1;
PreliminarySetup();
ret = cdevsw_add(RANDOM_MAJOR, &random_cdevsw);
if (ret < 0) {
printf("random_init: failed to allocate a major number!\n");
gRandomInstalled = 0;
return;
}
devfs_make_node(makedev (ret, 0), DEVFS_CHAR,
UID_ROOT, GID_WHEEL, 0666, "random", 0);
devfs_make_node(makedev (ret, 1), DEVFS_CHAR,
UID_ROOT, GID_WHEEL, 0666, "urandom", 0);
}
int
random_ioctl(dev, cmd, data, flag, p)
dev_t dev;
u_long cmd;
caddr_t data;
int flag;
struct proc *p;
{
switch (cmd) {
case FIONBIO:
case FIOASYNC:
break;
default:
return ENODEV;
}
return (0);
}
int
random_open(dev_t dev, int flags, int devtype, struct proc *p)
{
if (gRandomError != 0) {
return (ENOTSUP);
}
if (flags & FWRITE) {
if (securelevel >= 2)
return (EPERM);
#ifndef __APPLE__
if ((securelevel >= 1) && suser(p->p_ucred, &p->p_acflag))
return (EPERM);
#endif
}
return (0);
}
int
random_close(dev_t dev, int flags, int mode, struct proc *p)
{
return (0);
}
int
random_write (dev_t dev, struct uio *uio, int ioflag)
{
int retCode = 0;
char rdBuffer[256];
if (gRandomError != 0) {
return (ENOTSUP);
}
mutex_lock(gYarrowMutex);
while (uio->uio_resid > 0 && retCode == 0) {
int bytesToInput = min(uio->uio_resid, sizeof (rdBuffer));
retCode = uiomove(rdBuffer, bytesToInput, uio);
if (retCode != 0)
goto error_exit;
if (prngInput(gPrngRef, (BYTE*) rdBuffer,
sizeof (rdBuffer), SYSTEM_SOURCE,
sizeof (rdBuffer) * 8) != 0) {
retCode = EIO;
goto error_exit;
}
}
if (prngForceReseed(gPrngRef, RESEED_TICKS) != 0) {
retCode = EIO;
goto error_exit;
}
error_exit:
mutex_unlock(gYarrowMutex);
return (retCode);
}
int
random_read(dev_t dev, struct uio *uio, int ioflag)
{
int retCode = 0;
char wrBuffer[512];
if (gRandomError != 0)
return (ENOTSUP);
mutex_lock(gYarrowMutex);
while (uio->uio_resid > 0 && retCode == 0) {
int bytesToRead = min(uio->uio_resid, sizeof (wrBuffer));
if (prngOutput(gPrngRef, (BYTE *) wrBuffer, sizeof (wrBuffer)) != 0) {
printf ("Couldn't read data from Yarrow.\n");
retCode = EIO;
goto error_exit;
}
retCode = uiomove(wrBuffer, bytesToRead, uio);
if (retCode != 0)
goto error_exit;
}
retCode = 0;
error_exit:
mutex_unlock(gYarrowMutex);
return retCode;
}
void
read_random(void* buffer, u_int numbytes)
{
if (gYarrowMutex == 0) {
PreliminarySetup ();
}
mutex_lock(gYarrowMutex);
prngOutput(gPrngRef, (BYTE *) buffer, numbytes);
mutex_unlock(gYarrowMutex);
}
u_long
RandomULong()
{
u_long buf;
read_random(&buf, sizeof (buf));
return (buf);
}