/* Random bytes straight from the kernel, so the app needs no /dev/urandom
   inside its sandbox. */
#include <errno.h>
#include <string.h>
#include <sys/random.h>
#include <caml/alloc.h>
#include <caml/fail.h>
#include <caml/memory.h>
#include <caml/mlvalues.h>

CAMLprim value todo_getrandom(value len)
{
  CAMLparam1(len);
  CAMLlocal1(buf);
  size_t n = Long_val(len), got = 0;
  buf = caml_alloc_string(n);
  while (got < n) {
    ssize_t r = getrandom((char *)Bytes_val(buf) + got, n - got, 0);
    if (r < 0) {
      if (errno == EINTR) continue;
      caml_failwith(strerror(errno));
    }
    got += r;
  }
  CAMLreturn(buf);
}