socks5 protocol abstraction, based on deku.

deku_socks5.rs

use deku::prelude::*;

pub const SOCKS5_VERSION: u8 = 0x05;

#[derive(Default, Copy, Clone, DekuRead, DekuWrite)]
#[deku(id_type = "u8")]
pub enum Version {
    #[default]
    #[deku(id = 0x05)]
    Socks5,
}

#[derive(Default, Copy, Clone, DekuRead, DekuWrite)]
#[deku(id_type = "u8")]
pub enum ReservedZero {
    #[default]
    #[deku(id = 0x00)]
    Correct,
}

#[derive(Copy, Clone, PartialEq, Eq, DekuRead, DekuWrite)]
#[deku(id_type = "u8")]
pub enum Method {
    #[deku(id = 0x00)]
    NoAuthRequired,
    #[deku(id = 0x01)]
    GSSApi,
    #[deku(id = 0x02)]
    Basic,
    #[deku(id_pat = "0x03 ..= 0x7F")]
    INNAAssigned(u8),
    #[deku(id_pat = "0x80 ..= 0xFE")]
    Reserved(u8),
    #[deku(id = 0xFF)]
    NoAcceptable,
}

#[derive(DekuRead, DekuWrite)]
pub struct ClientHello {
    pub version: Version,
    pub methods_count: u8,
    #[deku(count = "methods_count")]
    pub methods: Vec<Method>,
}

#[derive(DekuRead, DekuWrite)]
pub struct ServerHello {
    pub version: Version,
    pub method: Method,
}

#[derive(Copy, Clone, PartialEq, Eq, DekuRead, DekuWrite)]
#[deku(id_type = "u8")]
pub enum ClientCommand {
    #[deku(id = 0x01)]
    Connect,
    #[deku(id = 0x02)]
    Bind,
    #[deku(id = 0x03)]
    UdpAssociate,
}

#[derive(Clone, PartialEq, Eq, DekuRead, DekuWrite)]
#[deku(id_type = "u8")]
pub enum Addr {
    #[deku(id = 0x01)]
    V4([u8; 4]),
    #[deku(id = 0x03)]
    Domain {
        count: u8,
        #[deku(count = "count")]
        domain: Vec<u8>,
    },
    #[deku(id = 0x04)]
    V6([u8; 16]),
}

#[derive(DekuRead, DekuWrite)]
pub struct ClientRequest {
    pub version: Version,
    pub command: ClientCommand,
    pub reserved: ReservedZero,
    pub addr: Addr,
    #[deku(endian = "big")]
    pub port: u16,
}

#[derive(Default, Copy, Clone, PartialEq, Eq, DekuRead, DekuWrite)]
#[deku(id_type = "u8")]
pub enum ServerReply {
    #[default]
    #[deku(id = 0x00)]
    Succeed,
    #[deku(id = 0x01)]
    GeneralSocksServerFailure,
    #[deku(id = 0x02)]
    ConnectionNotAllowedByRuleset,
    #[deku(id = 0x03)]
    NetworkUnreachable,
    #[deku(id = 0x04)]
    HostUnreachable,
    #[deku(id = 0x05)]
    ConnectionRefused,
    #[deku(id = 0x06)]
    TTLExpired,
    #[deku(id = 0x07)]
    CommandNotSupported,
    #[deku(id = 0x08)]
    AddressTypeNotSupported,
}

#[derive(DekuRead, DekuWrite)]
pub struct ServerResponse {
    pub version: Version,
    pub reply: ServerReply,
    pub reserved: ReservedZero,
    pub bind_addr: Addr,
    #[deku(endian = "big")]
    pub bind_port: u16,
}