123 lines
4.5 KiB
Rust
123 lines
4.5 KiB
Rust
use std::fmt;
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/// 地址解析协议，由IP地址找到MAC地址
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/// https://www.ietf.org/rfc/rfc6747.txt
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/*
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0 2 4 5 6 8 10 (字节)
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| 硬件类型|协议类型|硬件地址长度|协议地址长度|操作类型|
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| 源MAC地址 | 源ip地址 |
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| 目的MAC地址 | 目的ip地址 |
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*/
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use crate::error::*;
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pub struct ArpPacket<B> {
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buffer: B,
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}
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impl<B: AsRef<[u8]>> ArpPacket<B> {
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pub fn unchecked(buffer: B) -> Self {
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Self { buffer }
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}
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pub fn new(buffer: B) -> Result<Self> {
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if buffer.as_ref().len() != 28 {
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Err(Error::InvalidPacket)?
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}
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let packet = Self::unchecked(buffer);
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Ok(packet)
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}
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}
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impl<B: AsRef<[u8]>> ArpPacket<B> {
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/// 硬件类型 以太网类型为1
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pub fn hardware_type(&self) -> u16 {
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u16::from_be_bytes(self.buffer.as_ref()[0..2].try_into().unwrap())
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}
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/// 上层协议类型,ipv4是0x0800
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pub fn protocol_type(&self) -> u16 {
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u16::from_be_bytes(self.buffer.as_ref()[2..4].try_into().unwrap())
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}
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/// 如果是MAC地址 则长度为6
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pub fn hardware_size(&self) -> u8 {
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self.buffer.as_ref()[4]
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}
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/// 如果是IPv4 则长度为4
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pub fn protocol_size(&self) -> u8 {
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self.buffer.as_ref()[5]
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}
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/// 操作类型，请求和响应 1：ARP请求，2：ARP响应，3：RARP请求，4：RARP响应
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pub fn op_code(&self) -> u16 {
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u16::from_be_bytes(self.buffer.as_ref()[6..8].try_into().unwrap())
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}
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/// 发送端硬件地址，仅支持以太网
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pub fn sender_hardware_addr(&self) -> &[u8] {
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&self.buffer.as_ref()[8..14]
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}
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/// 发送端协议地址，仅支持IPv4
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pub fn sender_protocol_addr(&self) -> &[u8] {
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&self.buffer.as_ref()[14..18]
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}
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/// 接收端硬件地址，仅支持以太网
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pub fn target_hardware_addr(&self) -> &[u8] {
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&self.buffer.as_ref()[18..24]
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}
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/// 接收端协议地址，仅支持IPv4
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pub fn target_protocol_addr(&self) -> &[u8] {
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&self.buffer.as_ref()[24..28]
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}
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}
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impl<B: AsRef<[u8]> + AsMut<[u8]>> ArpPacket<B> {
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/// 硬件类型 以太网类型为1
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pub fn set_hardware_type(&mut self, value: u16) {
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self.buffer.as_mut()[0..2].copy_from_slice(&value.to_be_bytes())
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}
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/// 上层协议类型,ipv4是0x0800
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pub fn set_protocol_type(&mut self, value: u16) {
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self.buffer.as_mut()[2..4].copy_from_slice(&value.to_be_bytes())
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}
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/// 如果是MAC地址 则长度为6
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pub fn set_hardware_size(&mut self, value: u8) {
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self.buffer.as_mut()[4] = value
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}
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/// 如果是IPv4 则长度为4
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pub fn set_protocol_size(&mut self, value: u8) {
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self.buffer.as_mut()[5] = value
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}
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/// 操作类型，请求和响应 1：ARP请求，2：ARP响应，3：RARP请求，4：RARP响应
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pub fn set_op_code(&mut self, value: u16) {
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self.buffer.as_mut()[6..8].copy_from_slice(&value.to_be_bytes())
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}
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/// 发送端硬件地址，仅支持以太网
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pub fn set_sender_hardware_addr(&mut self, buf: &[u8]) {
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self.buffer.as_mut()[8..14].copy_from_slice(buf)
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}
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/// 发送端协议地址，仅支持IPv4
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pub fn set_sender_protocol_addr(&mut self, buf: &[u8]) {
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self.buffer.as_mut()[14..18].copy_from_slice(buf)
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}
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/// 接收端硬件地址，仅支持以太网
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pub fn set_target_hardware_addr(&mut self, buf: &[u8]) {
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self.buffer.as_mut()[18..24].copy_from_slice(buf)
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}
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/// 接收端协议地址，仅支持IPv4
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pub fn set_target_protocol_addr(&mut self, buf: &[u8]) {
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self.buffer.as_mut()[24..28].copy_from_slice(buf)
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}
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}
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impl<B: AsRef<[u8]>> fmt::Debug for ArpPacket<B> {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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f.debug_struct("ArpPacket")
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.field("hardware_type", &self.hardware_type())
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.field("protocol_type", &self.protocol_type())
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.field("hardware_size", &self.hardware_size())
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.field("protocol_size", &self.protocol_size())
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.field("op_code", &self.op_code())
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.field("sender_hardware_addr", &self.sender_hardware_addr())
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.field("sender_protocol_addr", &self.sender_protocol_addr())
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.field("target_hardware_addr", &self.target_hardware_addr())
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.field("target_protocol_addr", &self.target_protocol_addr())
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.finish()
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}
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} |