static void
uart_pps_process(struct uart_softc *sc, int ser_sig)
{
sbintime_t now;
int is_assert, pps_sig;
/* Which signal is configured as PPS? Early out if none. */
switch(sc->sc_pps_mode & UART_PPS_SIGNAL_MASK) {
case UART_PPS_CTS:
pps_sig = SER_CTS;
break;
case UART_PPS_DCD:
pps_sig = SER_DCD;
break;
default:
return;
}
/* Early out if there is no change in the signal configured as PPS. */
if ((ser_sig & SER_DELTA(pps_sig)) == 0)
return;
/*
* In narrow-pulse mode we need to synthesize both capture and clear
* events from a single "delta occurred" indication from the uart
* hardware because the pulse width is too narrow to reliably detect
* both edges. However, when the pulse width is close to our interrupt
* processing latency we might intermittantly catch both edges. To
* guard against generating spurious events when that happens, we use a
* separate timer to ensure at least half a second elapses before we
* generate another event.
*/
pps_capture(&sc->sc_pps);
if (sc->sc_pps_mode & UART_PPS_NARROW_PULSE) {
now = getsbinuptime();
if (now > sc->sc_pps_captime + 500 * SBT_1MS) {
sc->sc_pps_captime = now;
pps_event(&sc->sc_pps, PPS_CAPTUREASSERT);
pps_event(&sc->sc_pps, PPS_CAPTURECLEAR);
}
} else {
is_assert = ser_sig & pps_sig;
if (sc->sc_pps_mode & UART_PPS_INVERT_PULSE)
is_assert = !is_assert;
pps_event(&sc->sc_pps, is_assert ? PPS_CAPTUREASSERT :
PPS_CAPTURECLEAR);
}
}
/* The argument buf points to a whole number of blocks. */
void
random_fortuna_read(uint8_t *buf, u_int bytecount)
{
#ifdef _KERNEL
sbintime_t thistime;
#endif
struct randomdev_hash context;
uint8_t s[NPOOLS*KEYSIZE], temp[KEYSIZE];
int i;
u_int seedlength;
/* We must be locked for all this as plenty of state gets messed with */
mtx_lock(&random_reseed_mtx);
/* if buf == NULL and bytecount == 0 then this is the pre-read. */
/* if buf == NULL and bytecount != 0 then this is the post-read; ignore. */
if (buf == NULL) {
if (bytecount == 0) {
if (fortuna_state.pool[0].length >= fortuna_state.minpoolsize
#ifdef _KERNEL
/* F&S - Use 'getsbinuptime()' to prevent reseed-spamming. */
&& ((thistime = getsbinuptime()) - fortuna_state.lasttime > hz/10)
#endif
) {
#ifdef _KERNEL
fortuna_state.lasttime = thistime;
#endif
seedlength = 0U;
/* F&S - ReseedCNT = ReseedCNT + 1 */
fortuna_state.reseedcount++;
/* s = \epsilon by default */
for (i = 0; i < NPOOLS; i++) {
/* F&S - if Divides(ReseedCnt, 2^i) ... */
if ((fortuna_state.reseedcount % (1 << i)) == 0U) {
seedlength += KEYSIZE;
/* F&S - temp = (P_i) */
randomdev_hash_finish(&fortuna_state.pool[i].hash, temp);
/* F&S - P_i = \epsilon */
randomdev_hash_init(&fortuna_state.pool[i].hash);
fortuna_state.pool[i].length = 0U;
/* F&S - s = s|H(temp) */
randomdev_hash_init(&context);
randomdev_hash_iterate(&context, temp, KEYSIZE);
randomdev_hash_finish(&context, s + i*KEYSIZE);
}
else
break;
}
#ifdef RANDOM_DEBUG
printf("random: active reseed: reseedcount [%d] ", fortuna_state.reseedcount);
for (i = 0; i < NPOOLS; i++)
printf(" %d", fortuna_state.pool[i].length);
printf("\n");
#endif
/* F&S */
reseed(s, seedlength);
/* Clean up */
memset(s, 0, seedlength);
seedlength = 0U;
memset(temp, 0, sizeof(temp));
memset(&context, 0, sizeof(context));
}
}
}
/* if buf != NULL do a regular read. */
else
random_fortuna_genrandom(buf, bytecount);
mtx_unlock(&random_reseed_mtx);
}
