// Copyright (c) 2014, 2015 Robert Clipsham <robert@octarineparrot.com>
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! An ethernet packet abstraction.

use crate::{MacAddr, Packet, PrimitiveValues};
use std::fmt;

/// Represents an Ethernet packet.
#[derive(Debug, Packet)]
pub struct Ethernet {
    #[construct_with(u8, u8, u8, u8, u8, u8)]
    pub destination: MacAddr,
    #[construct_with(u8, u8, u8, u8, u8, u8)]
    pub source: MacAddr,
    #[construct_with(u16)]
    pub ethertype: EtherType,
    #[payload]
    pub payload: Vec<u8>,
}

#[test]
fn ethernet_header_test() {
    let mut packet = [0u8; 14];
    {
        let mut ethernet_header = MutableEthernetPacket::new(&mut packet[..]).unwrap();

        let source = MacAddr(0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc);
        ethernet_header.set_source(source);
        assert_eq!(ethernet_header.get_source(), source);

        let dest = MacAddr(0xde, 0xf0, 0x12, 0x34, 0x45, 0x67);
        ethernet_header.set_destination(dest);
        assert_eq!(ethernet_header.get_destination(), dest);

        ethernet_header.set_ethertype(EtherTypes::Ipv6);
        assert_eq!(ethernet_header.get_ethertype(), EtherTypes::Ipv6);
    }

    let ref_packet = [
        0xde, 0xf0, 0x12, 0x34, 0x45, 0x67, /* destination */
        0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, /* source */
        0x86, 0xdd, /* ethertype */
    ];
    assert_eq!(&ref_packet[..], &packet[..]);
}

/// `EtherTypes` are defined at:
/// http://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.xhtml.
/// These values should be used in the `Ethernet` `EtherType` field.
///
/// FIXME Should include all
/// A handful of these have been selected since most are archaic and unused.
#[allow(non_snake_case)]
#[allow(non_upper_case_globals)]
pub mod EtherTypes {
    use super::EtherType;

    /// Internet Protocol version 4 (IPv4) [RFC7042].
    pub const Ipv4: EtherType = EtherType(0x0800);
    /// Address Resolution Protocol (ARP) [RFC7042].
    pub const Arp: EtherType = EtherType(0x0806);
    /// Wake on Lan.
    pub const WakeOnLan: EtherType = EtherType(0x0842);
    /// IETF TRILL Protocol [IEEE].
    pub const Trill: EtherType = EtherType(0x22F3);
    /// DECnet Phase IV.
    pub const DECnet: EtherType = EtherType(0x6003);
    /// Reverse Address Resolution Protocol (RARP) [RFC903].
    pub const Rarp: EtherType = EtherType(0x8035);
    /// AppleTalk - EtherTalk [Apple].
    pub const AppleTalk: EtherType = EtherType(0x809B);
    /// AppleTalk Address Resolution Protocol (AARP) [Apple].
    pub const Aarp: EtherType = EtherType(0x80F3);
    /// IPX [Xerox].
    pub const Ipx: EtherType = EtherType(0x8137);
    /// QNX Qnet [QNX Software Systems].
    pub const Qnx: EtherType = EtherType(0x8204);
    /// Internet Protocol version 6 (IPv6) [RFC7042].
    pub const Ipv6: EtherType = EtherType(0x86DD);
    /// Ethernet Flow Control [IEEE 802.3x].
    pub const FlowControl: EtherType = EtherType(0x8808);
    /// CobraNet [CobraNet].
    pub const CobraNet: EtherType = EtherType(0x8819);
    /// MPLS Unicast [RFC 3032].
    pub const Mpls: EtherType = EtherType(0x8847);
    /// MPLS Multicast [RFC 5332].
    pub const MplsMcast: EtherType = EtherType(0x8848);
    /// PPPOE Discovery Stage [RFC 2516].
    pub const PppoeDiscovery: EtherType = EtherType(0x8863);
    /// PPPoE Session Stage [RFC 2516].
    pub const PppoeSession: EtherType = EtherType(0x8864);
    /// VLAN-tagged frame (IEEE 802.1Q).
    pub const Vlan: EtherType = EtherType(0x8100);
    /// Provider Bridging [IEEE 802.1ad / IEEE 802.1aq].
    pub const PBridge: EtherType = EtherType(0x88a8);
    /// Link Layer Discovery Protocol (LLDP) [IEEE 802.1AB].
    pub const Lldp: EtherType = EtherType(0x88cc);
    /// Precision Time Protocol (PTP) over Ethernet [IEEE 1588].
    pub const Ptp: EtherType = EtherType(0x88f7);
    /// CFM / Y.1731 [IEEE 802.1ag].
    pub const Cfm: EtherType = EtherType(0x8902);
    /// Q-in-Q Vlan Tagging [IEEE 802.1Q].
    pub const QinQ: EtherType = EtherType(0x9100);
}

/// Represents the `Ethernet::ethertype` field.
#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct EtherType(pub u16);

impl EtherType {
    /// Construct a new `EtherType` instance.
    pub fn new(val: u16) -> EtherType {
        EtherType(val)
    }
}

impl PrimitiveValues for EtherType {
    type T = (u16,);
    fn to_primitive_values(&self) -> (u16,) {
        (self.0,)
    }
}

impl fmt::Display for EtherType {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(
            f,
            "{}",
            match self {
                &EtherTypes::Ipv4 => "Ipv4",                     //(0x0800)
                &EtherTypes::Arp => "Arp",                       //(0x0806)
                &EtherTypes::WakeOnLan => "WakeOnLan",           //(0x0842)
                &EtherTypes::Trill => "Trill",                   //(0x22F3)
                &EtherTypes::DECnet => "DECnet",                 //(0x6003)
                &EtherTypes::Rarp => "Rarp",                     //(0x8035)
                &EtherTypes::AppleTalk => "AppleTalk",           //(0x809B)
                &EtherTypes::Aarp => "Aarp",                     //(0x80F3)
                &EtherTypes::Ipx => "Ipx",                       //(0x8137)
                &EtherTypes::Qnx => "Qnx",                       //(0x8204)
                &EtherTypes::Ipv6 => "Ipv6",                     //(0x86DD)
                &EtherTypes::FlowControl => "FlowControl",       //(0x8808)
                &EtherTypes::CobraNet => "CobraNet",             //(0x8819)
                &EtherTypes::Mpls => "Mpls",                     //(0x8847)
                &EtherTypes::MplsMcast => "MplsMcast",           //(0x8848)
                &EtherTypes::PppoeDiscovery => "PppoeDiscovery", //(0x8863)
                &EtherTypes::PppoeSession => "PppoeSession",     //(0x8864)
                &EtherTypes::Vlan => "Vlan",                     //(0x8100)
                &EtherTypes::PBridge => "PBridge",               //(0x88a8)
                &EtherTypes::Lldp => "Lldp",                     //(0x88cc)
                &EtherTypes::Ptp => "Ptp",                       //(0x88f7)
                &EtherTypes::Cfm => "Cfm",                       //(0x8902)
                &EtherTypes::QinQ => "QinQ",                     //(0x9100)
                _ => "unknown",
            }
        )
    }
}

#[test]
fn ether_type_to_str() {
    let ipv4 = EtherType(0x0800);
    assert_eq!(format!("{}", ipv4), "Ipv4");
    let arp = EtherType(0x0806);
    assert_eq!(format!("{}", arp), "Arp");
    let unknown = EtherType(0x0666);
    assert_eq!(format!("{}", unknown), "unknown");
}

#[cfg(all(test, feature = "benchmark"))]
mod packet_benchmarks {
    use super::*;
    use test::{black_box, Bencher};

    use util::MacAddr;

    #[bench]
    fn bench_packet_new_constructor(b: &mut Bencher) {
        let buffer = vec![0; 20];
        b.iter(|| EthernetPacket::new(black_box(&buffer)).unwrap());
    }

    #[bench]
    fn bench_packet_get_source(b: &mut Bencher) {
        let buffer = vec![0; 20];
        let packet = EthernetPacket::new(&buffer).unwrap();
        b.iter(|| black_box(packet.get_source()));
    }

    #[bench]
    fn bench_packet_set_source_black_box(b: &mut Bencher) {
        let mut buffer = vec![0; 20];
        let mut packet = MutableEthernetPacket::new(&mut buffer).unwrap();
        let mac = MacAddr::new(1, 2, 3, 4, 5, 6);
        b.iter(|| packet.set_source(black_box(mac)));
    }

    #[bench]
    fn bench_packet_mutable_to_immutable(b: &mut Bencher) {
        let mut buffer = vec![0; 20];
        let mut packet = MutableEthernetPacket::new(&mut buffer).unwrap();
        b.iter(|| black_box(packet.to_immutable()));
    }

    #[bench]
    fn bench_packet_immutable_to_immutable(b: &mut Bencher) {
        let mut buffer = vec![0; 20];
        let mut packet = EthernetPacket::new(&mut buffer).unwrap();
        b.iter(|| black_box(packet.to_immutable()));
    }
}