Write inbound packets to TUN device

1 files changed, 37 insertions, 0 deletions

diff --git a/src/router/ip.rs b/src/router/ip.rs
new file mode 100644
index 0000000..6eb303c
--- /dev/null
+++ b/src/router/ip.rs
@@ -0,0 +1,37 @@
+use byteorder::BigEndian;
+use zerocopy::byteorder::U16;
+use zerocopy::{AsBytes, ByteSlice, FromBytes, LayoutVerified};
+
+pub const SIZE_IP4_HEADER: usize = 16;
+pub const SIZE_IP6_HEADER: usize = 36;
+
+pub const VERSION_IP4: u8 = 4;
+pub const VERSION_IP6: u8 = 6;
+
+pub const OFFSET_IP4_SRC: usize = 12;
+pub const OFFSET_IP6_SRC: usize = 8;
+
+pub const OFFSET_IP4_DST: usize = 16;
+pub const OFFSET_IP6_DST: usize = 24;
+
+pub const TYPE_TRANSPORT: u8 = 4;
+
+#[repr(packed)]
+#[derive(Copy, Clone, FromBytes, AsBytes)]
+pub struct IPv4Header {
+    _f_space1: [u8; 2],
+    pub f_total_len: U16<BigEndian>,
+    _f_space2: [u8; 8],
+    pub f_source: [u8; 4],
+    pub f_destination: [u8; 4],
+}
+
+#[repr(packed)]
+#[derive(Copy, Clone, FromBytes, AsBytes)]
+pub struct IPv6Header {
+    _f_pre: [u8; 4],
+    pub f_len: U16<BigEndian>,
+    _f_space2: [u8; 2],
+    pub f_source: [u8; 16],
+    pub f_destination: [u8; 16],
+}