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static char rcsid[] = "$Header: /home/sater/bridge/bigdeal/RCS/unix.c,v 1.11 2000/08/25 15:55:53 sater Exp $";
#include <sys/termios.h>
#include <sys/time.h>
#include <ctype.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include "types.h"
#include "bigdeal.h"
#include "collect.h"
extern FILE *flog;
#ifdef TIOCSETA
/*
* For example on BSDI
*/
#define GTTY TIOCGETA
#define STTY TIOCSETA
#else
/*
* For example on SunOS
*/
#define GTTY TCGETS
#define STTY TCSETSF
#endif /* TIOCSETA */
static int subsecbits = 5;
#define MAX_INTERVAL_ENTROPY 6
void
gettod(struct timeval *tp)
/*
* Fill in *tp with gettimeofday values
* Side effect: calculate approx precision
*/
{
int b;
gettimeofday(tp, (struct timezone *) 0);
/* Find how many bits are set in usec field */
for(b = 0; b < 20; b++) {
if (tp->tv_usec&(1<<b))
break;
}
if (20-b > subsecbits) {
subsecbits = 20-b;
}
}
int
getchtm(int *nbits)
/*
* Read one character from standard input
* Time the wait, and use bits for random
* MUST be in cbreak mode for this to work
*/
{
struct timeval t1, t2;
long sdiff, mdiff;
int c;
long shift;
int b;
gettod(&t1);
c = getchar();
gettod(&t2);
mdiff = t2.tv_usec - t1.tv_usec;
sdiff = t2.tv_sec - t1.tv_sec;
if (sdiff > 1000)
sdiff = 1000;
mdiff += sdiff * 1000000;
/*
* Everything slower than 1/8 second can be faked
* Trust at most half of the rest
*/
for (shift = mdiff, b= 0; shift>3 ; shift >>= 2, b++)
;
if (b <= MAX_INTERVAL_ENTROPY)
*nbits = b;
else
*nbits = MAX_INTERVAL_ENTROPY;
collect_more((byte *) &t1, sizeof(t1), 0);
collect_more((byte *) &t2, sizeof(t2), 0);
if (flog)
fprintf(flog, "Collected character %d, timediff %ld, timebits %d\n",
c, mdiff, *nbits);
return c;
}
void
os_collect() {
int pid;
struct timeval t;
pid = getpid();
/* Trust about 8 bits of randomness in pid */
collect_more((byte *) &pid, sizeof(pid), 8);
gettod(&t);
/* Trust 6 bits of seconds, and half the subsecond bits */
collect_more((byte *) &t, sizeof(t), 6+subsecbits/2);
if (flog)
fprintf(flog, "First TOD=(%ld, %ld), subsecbits = %d\n",
t.tv_sec, t.tv_usec, subsecbits);
}
static struct termios tios;
void
cbreak()
/*
* Set terminal to state where characters can be read one at a time
* Also disable echo
*/
{
struct termios newtios;
newtios = tios;
/* fiddle newtios */
newtios.c_lflag &= ~(ICANON|ECHO);
newtios.c_cc[VMIN] = 1;
newtios.c_cc[VTIME] = 0;
ioctl(0, STTY, &newtios);
}
void
cooked()
/*
* Reset terminal to original state
*/
{
ioctl(0, STTY, &tios);
}
void
os_start() {
ioctl(0, GTTY, &tios);
}
void
os_finish() {
cooked();
}
int
legal_filename_prefix(char *s)
/*
* Legal prefix to make legal name when three letter suffix added
*/
{
if (*s == 0) /* Too short */
return 0;
if (strlen(s) > 10) /* Worst case, System V */
return 0;
while (*s) {
if (*s == '/' || *s == ' ') /* disallow space */
return 0;
s++;
}
return 1;
}
char *os_init_file_name()
{
return ".bigdealrc";
}
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