nsz Git - musl/blob - src/misc/getentropy.c

   1 #include <sys/random.h>
   2 #include <pthread.h>
   3 #include <errno.h>
   4
   5 int getentropy(void *buffer, size_t len)
   6 {
   7         int cs, ret;
   8         char *pos = buffer;
   9
  10         if (len > 256) {
  11                 errno = EIO;
  12                 return -1;
  13         }
  14
  15         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
  16
  17         while (len) {
  18                 ret = getrandom(pos, len, 0);
  19                 if (ret < 0) {
  20                         if (errno == EINTR) continue;
  21                         else break;
  22                 }
  23                 pos += ret;
  24                 len -= ret;
  25                 ret = 0;
  26         }
  27
  28         pthread_setcancelstate(cs, 0);
  29
  30         return ret;
  31 }