code.delx.au - linux-getrandom-userspace/blob - getrandom.c

   1 #include <fcntl.h>
   2 #include <unistd.h>
   3 #include <sys/random.h>
   4
   5 ssize_t getrandom(void *buf, size_t buflen, unsigned int flags) {
   6     char* filename = flags & GRND_RANDOM ? "/dev/random" : "/dev/urandom";
   7     int nonblock = flags & GRND_NONBLOCK ? O_NONBLOCK : 0;
   8     int oflags = O_CLOEXEC | nonblock;
   9
  10     int fd = open(filename, oflags);
  11     if (fd < 0) {
  12         return -1;
  13     }
  14
  15     ssize_t bytes = read(fd, buf, buflen);
  16
  17     close(fd);
  18
  19     return bytes;
  20 }