支持点对网

This commit is contained in:
lubeilin
2023-05-28 20:28:58 +08:00
parent 94def558fc
commit c412a256b8
27 changed files with 1321 additions and 544 deletions
+26 -43
View File
@@ -1,7 +1,5 @@
use std::fmt;
use std::net::IpAddr;
use byteorder::{BigEndian, ReadBytesExt};
use std::net::Ipv4Addr;
use crate::error::*;
use crate::tcp::Flags;
@@ -48,20 +46,20 @@ use crate::tcp::Flags;
Options+Padding:32位整数倍,最多40个字节
*/
pub struct TcpPacket<B> {
source_ip: IpAddr,
destination_ip: IpAddr,
source_ip: Ipv4Addr,
destination_ip: Ipv4Addr,
buffer: B,
}
impl<B: AsRef<[u8]>> TcpPacket<B> {
pub fn unchecked(source_ip: IpAddr, destination_ip: IpAddr, buffer: B) -> TcpPacket<B> {
pub fn unchecked(source_ip: Ipv4Addr, destination_ip: Ipv4Addr, buffer: B) -> TcpPacket<B> {
TcpPacket {
source_ip,
destination_ip,
buffer,
}
}
pub fn new(source_ip: IpAddr, destination_ip: IpAddr, buffer: B) -> Result<TcpPacket<B>> {
pub fn new(source_ip: Ipv4Addr, destination_ip: Ipv4Addr, buffer: B) -> Result<TcpPacket<B>> {
let packet = TcpPacket::unchecked(source_ip, destination_ip, buffer);
if packet.buffer.as_ref().len() < 20 {
@@ -80,6 +78,12 @@ impl<B: AsRef<[u8]> + AsMut<[u8]>> TcpPacket<B> {
fn set_checksum(&mut self, value: u16) {
self.buffer.as_mut()[16..18].copy_from_slice(&value.to_be_bytes())
}
pub fn set_source_port(&mut self, value: u16) {
self.buffer.as_mut()[0..2].copy_from_slice(&value.to_be_bytes())
}
pub fn set_destination_port(&mut self, value: u16) {
self.buffer.as_mut()[2..4].copy_from_slice(&value.to_be_bytes())
}
/// 更新校验和
pub fn update_checksum(&mut self) {
//先将校验和置0
@@ -87,31 +91,24 @@ impl<B: AsRef<[u8]> + AsMut<[u8]>> TcpPacket<B> {
self.set_checksum(self.cal_checksum())
}
}
impl<B: AsRef<[u8]>> TcpPacket<B> {
/// 源端口
pub fn source_port(&self) -> u16 {
(&self.buffer.as_ref()[0..])
.read_u16::<BigEndian>()
.unwrap()
u16::from_be_bytes(self.buffer.as_ref()[0..2].try_into().unwrap())
}
/// 目标端口
pub fn destination_port(&self) -> u16 {
(&self.buffer.as_ref()[2..])
.read_u16::<BigEndian>()
.unwrap()
u16::from_be_bytes(self.buffer.as_ref()[2..4].try_into().unwrap())
}
/// 序列号
pub fn sequence(&self) -> u32 {
(&self.buffer.as_ref()[4..])
.read_u32::<BigEndian>()
.unwrap()
u32::from_be_bytes(self.buffer.as_ref()[4..8].try_into().unwrap())
}
/// 确认号
pub fn acknowledgment(&self) -> u32 {
(&self.buffer.as_ref()[8..])
.read_u32::<BigEndian>()
.unwrap()
u32::from_be_bytes(self.buffer.as_ref()[8..12].try_into().unwrap())
}
/// 数据偏移 4字节为单位
pub fn data_offset(&self) -> u8 {
@@ -121,14 +118,10 @@ impl<B: AsRef<[u8]>> TcpPacket<B> {
Flags(self.buffer.as_ref()[13])
}
pub fn window(&self) -> u16 {
(&self.buffer.as_ref()[14..])
.read_u16::<BigEndian>()
.unwrap()
u16::from_be_bytes(self.buffer.as_ref()[14..16].try_into().unwrap())
}
pub fn checksum(&self) -> u16 {
(&self.buffer.as_ref()[16..])
.read_u16::<BigEndian>()
.unwrap()
u16::from_be_bytes(self.buffer.as_ref()[16..18].try_into().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
/// TCP/IP协议栈不会自己计算校验和,而是简单地将一个空的校验和字段(零或随机填充)交给网卡硬件。
@@ -137,26 +130,16 @@ impl<B: AsRef<[u8]>> TcpPacket<B> {
self.checksum() == 0 || self.cal_checksum() == 0
}
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,
6,
self.buffer.as_ref().len() as u16,
);
}
}
IpAddr::V6(_src) => {}
}
unimplemented!()
crate::ipv4_cal_checksum(
self.buffer.as_ref(),
&self.source_ip,
&self.destination_ip,
6,
self.buffer.as_ref().len() as u16,
)
}
pub fn urgent_pointer(&self) -> u16 {
(&self.buffer.as_ref()[18..])
.read_u16::<BigEndian>()
.unwrap()
u16::from_be_bytes(self.buffer.as_ref()[18..20].try_into().unwrap())
}
pub fn options(&self) -> &[u8] {
&self.buffer.as_ref()[20..(self.data_offset() as usize * 4)]