project strucute refactoring

core/src/rawcast/frame.rs

@@ -0,0 +1,149 @@
+use bytes::{Buf, BufMut, Bytes, BytesMut};
+use std::net::Ipv4Addr;
+
+use crate::parser::Parser;
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+#[repr(u8)]
+pub enum LocalProtocol {
+    Tcp = 0x01,
+    Udp = 0x02,
+    Icmp = 0x03,
+}
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+#[repr(u8)]
+pub enum RawCastEvent {
+    Connect = 0x01,
+    Data = 0x02,
+    Close = 0x03,
+}
+
+#[derive(Debug, Clone)]
+pub struct RawCastFrame {
+    pub protocol: LocalProtocol,
+    pub event: RawCastEvent,
+    pub socket_id: u64,
+    pub dst_ip: Ipv4Addr,
+    pub dst_port: u16,
+    pub payload: Bytes,
+}
+
+const LOCAL_HEADER_SIZE: usize = 16;
+
+impl RawCastFrame {
+    fn new(
+        protocol: LocalProtocol,
+        event: RawCastEvent,
+        socket_id: u64,
+        dst_ip: Ipv4Addr,
+        dst_port: u16,
+        payload: Bytes,
+    ) -> Self {
+        Self {
+            protocol,
+            event,
+            socket_id,
+            dst_ip,
+            dst_port,
+            payload,
+        }
+    }
+
+    pub fn connect(protocol: LocalProtocol, id: u64, ip: Ipv4Addr, port: u16) -> Self {
+        Self::new(protocol, RawCastEvent::Connect, id, ip, port, Bytes::new())
+    }
+
+    pub fn data(protocol: LocalProtocol, id: u64, ip: Ipv4Addr, port: u16, data: Vec<u8>) -> Self {
+        Self::new(
+            protocol,
+            RawCastEvent::Data,
+            id,
+            ip,
+            port,
+            Bytes::from(data),
+        )
+    }
+
+    pub fn close(protocol: LocalProtocol, id: u64, ip: Ipv4Addr, port: u16) -> Self {
+        Self::new(protocol, RawCastEvent::Close, id, ip, port, Bytes::new())
+    }
+
+    pub fn into_bytes(self) -> BytesMut {
+        let total_size = LOCAL_HEADER_SIZE + 2 + self.payload.len();
+        let mut buf = BytesMut::with_capacity(total_size);
+
+        buf.put_u8(self.protocol as u8);
+        buf.put_u8(self.event as u8);
+        buf.put_u64(self.socket_id);
+        buf.put_slice(&self.dst_ip.octets());
+        buf.put_u16(self.dst_port);
+        buf.put_u16(self.payload.len() as u16);
+        buf.put(self.payload);
+
+        buf
+    }
+}
+
+impl Parser for RawCastFrame {
+    type Error = String;
+
+    fn can_parse(bytes: &BytesMut) -> bool {
+        if bytes.len() < LOCAL_HEADER_SIZE + 2 {
+            return false;
+        }
+
+        // читаем длину payload без сдвига буфера
+        let payload_len_pos = LOCAL_HEADER_SIZE;
+        let payload_len =
+            u16::from_be_bytes([bytes[payload_len_pos], bytes[payload_len_pos + 1]]) as usize;
+
+        bytes.len() >= LOCAL_HEADER_SIZE + 2 + payload_len
+    }
+
+    fn parse(buf: &mut BytesMut) -> Result<Option<Self>, Self::Error> {
+        if !Self::can_parse(buf) {
+            return Ok(None);
+        }
+
+        let mut header = buf.split_to(LOCAL_HEADER_SIZE);
+
+        let protocol = match header.get_u8() {
+            0x01 => LocalProtocol::Tcp,
+            0x02 => LocalProtocol::Udp,
+            0x03 => LocalProtocol::Icmp,
+            p => return Err(format!("Unknown local protocol: {}", p)),
+        };
+
+        let event = match header.get_u8() {
+            0x01 => RawCastEvent::Connect,
+            0x02 => RawCastEvent::Data,
+            0x03 => RawCastEvent::Close,
+            e => return Err(format!("Unknown local event: {}", e)),
+        };
+
+        let socket_id = header.get_u64();
+
+        let ip_bytes = [
+            header.get_u8(),
+            header.get_u8(),
+            header.get_u8(),
+            header.get_u8(),
+        ];
+        let dst_ip = Ipv4Addr::from(ip_bytes);
+
+        let dst_port = header.get_u16();
+
+        let payload_len = buf.get_u16() as usize;
+        let payload = buf.split_to(payload_len).freeze();
+
+        Ok(Some(Self {
+            protocol,
+            event,
+            socket_id,
+            dst_ip,
+            dst_port,
+            payload,
+        }))
+    }
+}