libpacket

用于各种协议的包解析器。

从未维护的 libpnet 中提取。

lib.rs:

The pnet_macros crate provides the #[packet] macro and compiler plugin, which is used to specify the format of on-the-wire packets, and automatically generate zero-copy accessors and mutators for the fields. It is used as follows

/// Import the `Packet` custom derive attribute
use libpacket_derive::Packet;
/// This module contains a list of type aliases which may be used
use libpacket_core::types::{u4, u12be};

/// Packets are specified in the same way as normal Rust structs, but with a `#[packet]`
/// attribute.
#[derive(Packet)]
pub struct Example {
    // This is a simple field which contains a 4-bit, unsigned integer.
    // Note that `u4` is simply an alias for `u8` - the name is a hint
    // to the compiler plugin, it is NOT a usable 4 bit type!
    simple_field1: u4,

    // This specifies that `simple_field2` should be a 12-bit field,
    // with bits stored in big endian
    simple_field2: u12be,

    // All packets must specify a `#[payload]`, which should be a
    // `Vec<u8>`. This represents the packet's payload, for example in
    // an IPv4 packet, the payload could be a UDP packet, or in a UDP
    // packet the payload could be the application data. All the
    // remaining space in the packet is considered to be the payload
    // (this doesn't have to be the case, see the documentation for
    // `#[payload]` below.
    #[payload]
    payload: Vec<u8>
}

A number of things will then be generated. You can see this in action in the documentation and source of each of the packet types in the pnet::packet module. Things generated include (assuming the Example struct from above)

• An ExamplePacket<'p> structure, which is used for receiving packets on the network. This structure contains
  • A method, pub fn new<'p>(packet: &'p [u8]) -> ExamplePacket<'p>, used for the construction of an ExamplePacket, given a buffer to store it. The buffer should be long enough to contain all the fields in the packet.
  • 一种方法，pub fn to_immutable<'p>(&'p self) -> ExamplePacket<'p>，它只是一个恒等函数。它的存在是为了与MutableExamplePacket保持一致。
  • 一些访问器方法，形式为pub get_{field_name}(&self) -> {field_type}，用于检索在线值的宿主表示。
• 一个MutableExamplePacket<'p>结构体，在网络发送数据包时使用。该结构体包含
  • 一种方法，pub fn new<'p>(packet: &'p mut [u8]) -> MutableExamplePacket<'p>，用于根据存储它的缓冲区构建一个MutableExamplePacket。该缓冲区应足够长，可以包含数据包中的所有字段。
  • 一种方法，pub fn to_immutable<'p>(&'p self) -> ExamplePacket<'p>，它将MutableExamplePacket转换为ExamplePacket
  • 一种方法，pub fn populate(&mut self, packet: Example)，给定一个Example结构体，将使用Example结构体中的值填充MutableExamplePacket。
  • 一些访问器方法，形式为pub get_{field_name}(&self) -> {field_type}，用于检索在线值的宿主表示。
  • 存在多种修改器方法，其形式为 pub set_{字段名}(&mut self, val: {字段类型})，该方法将接受一个主机值，将其转换为所需的在线格式，并将其存储在支持 MutableExamplePacket 的缓冲区中。
• 为每个 MutableExamplePacket 和 ExamplePacket 结构实现了一系列特性和方法。这些包括
  • pnet::packet::Packet （ExamplePacket 和 MutableExamplePacket）
  • pnet::packet::MutablePacket （仅 MutableExamplePacket）
  • std::fmt::Debug （ExamplePacket 和 MutableExamplePacket）
  • pnet::packet::FromPacket （ExamplePacket 和 MutableExamplePacket）
  • pnet::packet::PacketSize （ExamplePacket 和 MutableExamplePacket）
• 一个 ExampleIterator 结构，它实现了 std::iter::Iterator，允许遍历另一个数据包中包含的 ExamplePacket 向量。内部使用。