调整项目结构、尝试支持安卓

2023-01-08 15:38:45 +08:00
parent d956e493af
commit 292893e9dd
76 changed files with 1132 additions and 588 deletions
@@ -0,0 +1 @@
+pub mod udp;
@@ -0,0 +1,177 @@
+use std::fmt;
+use std::io::Cursor;
+use std::net::IpAddr;
+
+use byteorder::WriteBytesExt;
+use byteorder::{BigEndian, ReadBytesExt};
+
+use crate::error::*;
+
+/// udp协议
+///
+/*
+RFC 768   https://www.ietf.org/rfc/rfc768.txt
+
+    0      7 8     15 16    23 24    31
+    +--------+--------+--------+--------+
+    |     源端口(16)   |   目的端口(16)    |
+    +--------+--------+--------+--------+
+    |     长度(16)     |    校验和(16)    |
+    +--------+--------+--------+--------+
+    |
+    |               载荷 ...
+    +---------------- ...
+
+    注：1.长度包含标头和数据体，以字节为单位
+       2.伪首部和载荷参与校验和的计算，位数不够则补0
+*/
+
+/// ipv6 udp伪首部
+/*  https://datatracker.ietf.org/doc/html/rfc2460
+
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |                                                               |
+  +                                                               +
+  |                                                               |
+  +                         Source Address                        +
+  |                                                               |
+  +                                                               +
+  |                                                               |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |                                                               |
+  +                                                               +
+  |                                                               |
+  +                      Destination Address                      +
+  |                                                               |
+  +                                                               +
+  |                                                               |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |                   Upper-Layer Packet Length                   |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |                      zero                     |  Next Header  |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+*/
+
+pub struct UdpPacket<B> {
+    source_ip: IpAddr,
+    destination_ip: IpAddr,
+    buffer: B,
+}
+
+impl<B: AsRef<[u8]>> UdpPacket<B> {
+    pub fn unchecked(source_ip: IpAddr, destination_ip: IpAddr, buffer: B) -> UdpPacket<B> {
+        UdpPacket {
+            source_ip,
+            destination_ip,
+            buffer,
+        }
+    }
+    pub fn new(source_ip: IpAddr, destination_ip: IpAddr, buffer: B) -> Result<UdpPacket<B>> {
+        if buffer.as_ref().len() < 8 {
+            Err(Error::SmallBuffer)?
+        }
+        let packet = Self::unchecked(source_ip, destination_ip, buffer);
+        Ok(packet)
+    }
+}
+
+impl<B: AsRef<[u8]>> UdpPacket<B> {
+    /// 源端口
+    pub fn source_port(&self) -> u16 {
+        (&self.buffer.as_ref()[0..])
+            .read_u16::<BigEndian>()
+            .unwrap()
+    }
+
+    /// 目标端口
+    pub fn destination_port(&self) -> u16 {
+        (&self.buffer.as_ref()[2..])
+            .read_u16::<BigEndian>()
+            .unwrap()
+    }
+
+    /// 总字节数
+    pub fn length(&self) -> u16 {
+        (&self.buffer.as_ref()[4..])
+            .read_u16::<BigEndian>()
+            .unwrap()
+    }
+
+    /// Checksum of the packet.
+    pub fn checksum(&self) -> u16 {
+        (&self.buffer.as_ref()[6..])
+            .read_u16::<BigEndian>()
+            .unwrap()
+    }
+    /// 验证校验和,ipv4中为0表示不使用校验和，ipv6校验和不能为0
+    pub fn is_valid(&self) -> bool {
+        self.checksum() == 0 || self.cal_checksum() == 0
+    }
+    pub fn payload(&self) -> &[u8] {
+        &self.buffer.as_ref()[8..]
+    }
+    fn cal_checksum(&self) -> u16 {
+        match self.source_ip {
+            IpAddr::V4(src) => {
+                if let IpAddr::V4(dest) = self.destination_ip {
+                    return crate::ipv4_cal_checksum(
+                        self.buffer.as_ref(),
+                        &src,
+                        &dest,
+                        17,
+                        self.length(),
+                    );
+                }
+            }
+            IpAddr::V6(_src) => {}
+        }
+        unimplemented!()
+    }
+}
+
+impl<B: AsRef<[u8]> + AsMut<[u8]>> UdpPacket<B> {
+    fn header_mut(&mut self) -> &mut [u8] {
+        &mut self.buffer.as_mut()[..8]
+    }
+}
+
+impl<B: AsRef<[u8]> + AsMut<[u8]>> UdpPacket<B> {
+    /// 设置源端口
+    pub fn set_source_port(&mut self, value: u16) -> &mut Self {
+        Cursor::new(&mut self.header_mut()[0..])
+            .write_u16::<BigEndian>(value)
+            .unwrap();
+        self
+    }
+
+    /// 设置目的端口
+    pub fn set_destination_port(&mut self, value: u16) -> &mut Self {
+        Cursor::new(&mut self.header_mut()[2..])
+            .write_u16::<BigEndian>(value)
+            .unwrap();
+        self
+    }
+    fn set_checknum(&mut self, value: u16) {
+        Cursor::new(&mut self.header_mut()[6..])
+            .write_u16::<BigEndian>(value)
+            .unwrap();
+    }
+    pub fn update_checknum(&mut self) {
+        //先写0
+        self.set_checknum(0);
+        self.set_checknum(self.cal_checksum());
+    }
+}
+
+impl<B: AsRef<[u8]>> fmt::Debug for UdpPacket<B> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("udp::Packet")
+            .field("source", &self.source_port())
+            .field("destination", &self.destination_port())
+            .field("length", &self.length())
+            .field("checksum", &self.checksum())
+            .field("is_valid", &self.is_valid())
+            .field("payload", &self.payload())
+            .finish()
+    }
+}