1 files changed, 27 insertions, 0 deletions
diff --git a/src/ioctl/bsd.rs b/src/ioctl/bsd.rs
new file mode 100644
index 0000000..2639d81
--- /dev/null
+++ b/src/ioctl/bsd.rs
@@ -0,0 +1,27 @@
+//! `ioctl` opcode behavior for BSD platforms.
+
+use super::{Direction, RawOpcode};
+
+pub(super) const fn compose_opcode(
+    dir: Direction,
+    group: RawOpcode,
+    num: RawOpcode,
+    size: RawOpcode,
+) -> RawOpcode {
+    let dir = match dir {
+        Direction::None => NONE,
+        Direction::Read => READ,
+        Direction::Write => WRITE,
+        Direction::ReadWrite => READ | WRITE,
+    };
+
+    dir | num | (group << 8) | ((size & IOCPARAM_MASK) << 16)
+}
+
+// `IOC_VOID`
+pub const NONE: RawOpcode = 0x2000_0000;
+// `IOC_OUT` ("out" is from the perspective of the kernel)
+pub const READ: RawOpcode = 0x4000_0000;
+// `IOC_IN`
+pub const WRITE: RawOpcode = 0x8000_0000;
+pub const IOCPARAM_MASK: RawOpcode = 0x1FFF;