46 lines
1.5 KiB
Diff
46 lines
1.5 KiB
Diff
diff --git a/src/header/unistd/mod.rs b/src/header/unistd/mod.rs
|
|
--- a/src/header/unistd/mod.rs
|
|
+++ b/src/header/unistd/mod.rs
|
|
@@ -537,8 +537,39 @@
|
|
|
|
/// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/getentropy.html>.
|
|
// #[unsafe(no_mangle)]
|
|
-pub extern "C" fn getentropy(buffer: *mut c_void, length: size_t) -> c_int {
|
|
- unimplemented!();
|
|
+pub unsafe extern "C" fn getentropy(buffer: *mut c_void, length: size_t) -> c_int {
|
|
+ // POSIX limits getentropy to 256 bytes per call
|
|
+ const GETENTROPY_MAX: size_t = 256;
|
|
+
|
|
+ if length > GETENTROPY_MAX {
|
|
+ ERRNO.set(EINVAL);
|
|
+ return -1;
|
|
+ }
|
|
+
|
|
+ let path = unsafe { CStr::from_ptr(c"/scheme/rand".as_ptr().cast()) };
|
|
+ let fd = match Sys::open(path, fcntl::O_RDONLY, 0) {
|
|
+ Ok(fd) => fd,
|
|
+ Err(Errno(e)) => {
|
|
+ ERRNO.set(e);
|
|
+ return -1;
|
|
+ }
|
|
+ };
|
|
+
|
|
+ let buf = unsafe { slice::from_raw_parts_mut(buffer.cast::<u8>(), length) };
|
|
+ let mut filled = 0usize;
|
|
+ while filled < length {
|
|
+ match Sys::read(fd, &mut buf[filled..]) {
|
|
+ Ok(0) => break,
|
|
+ Ok(n) => filled += n,
|
|
+ Err(Errno(e)) => {
|
|
+ let _ = Sys::close(fd);
|
|
+ ERRNO.set(e);
|
|
+ return -1;
|
|
+ }
|
|
+ }
|
|
+ }
|
|
+ let _ = Sys::close(fd);
|
|
+ if filled < length { ERRNO.set(errno::EIO); -1 } else { 0 }
|
|
}
|
|
|
|
/// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/geteuid.html>.
|