diff options
Diffstat (limited to 'unix.c')
| -rw-r--r-- | unix.c | 177 |
1 files changed, 177 insertions, 0 deletions
@@ -0,0 +1,177 @@ +
+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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