Merge #469

469: Add IEEE 802.15.4/6LoWPAN support r=Dirbaio a=thibautvdv

This adds the IEEE 802.15.4 frame representation.
Still a work in progress and interested to know what you think about this.

I really would like to add 6LowPAN as well, however I'm not sure where to put this in smoltcp, since 6LowPAN is kind of weird.

Co-authored-by: Thibaut Vandervelden <thvdveld@vub.be>
Co-authored-by: Dario Nieuwenhuis <dirbaio@dirbaio.net>

.github/workflows/test.yml

@@ -73,7 +73,7 @@ jobs:
 
         features:
           # These feature sets cannot run tests, so we only check they build.
-          - rand-custom-impl medium-ip medium-ethernet proto-ipv6 proto-ipv6 proto-igmp proto-dhcpv4 socket-raw socket-udp socket-tcp socket-icmp async
+          - rand-custom-impl medium-ip medium-ethernet medium-ieee802154 proto-ipv6 proto-ipv6 proto-igmp proto-dhcpv4 socket-raw socket-udp socket-tcp socket-icmp async
           - rand-custom-impl defmt defmt-trace medium-ip medium-ethernet proto-ipv6 proto-ipv6 proto-igmp proto-dhcpv4 socket-raw socket-udp socket-tcp socket-icmp async
 
     steps:

Cargo.toml

@@ -37,18 +37,24 @@ verbose = []
 rand-custom-impl = []
 "medium-ethernet" = ["socket"]
 "medium-ip" = ["socket"]
-"phy-raw_socket" = ["std", "libc", "medium-ethernet"]
+"medium-ieee802154" = ["socket", "proto-sixlowpan"]
+
+"phy-raw_socket" = ["std", "libc"]
 "phy-tuntap_interface" = ["std", "libc", "medium-ethernet"]
+
 "proto-ipv4" = []
 "proto-igmp" = ["proto-ipv4"]
 "proto-dhcpv4" = ["proto-ipv4"]
 "proto-ipv6" = []
+"proto-sixlowpan" = ["proto-ipv6"]
+
 "socket" = []
 "socket-raw" = ["socket"]
 "socket-udp" = ["socket"]
 "socket-tcp" = ["socket"]
 "socket-icmp" = ["socket"]
 "socket-dhcpv4" = ["socket", "medium-ethernet", "proto-dhcpv4"]
+
 "async" = []
 
 defmt-trace = []
@@ -59,9 +65,9 @@ defmt-error = []
 
 default = [
   "std", "log", # needed for `cargo test --no-default-features --features default` :/
-  "medium-ethernet", "medium-ip",
+  "medium-ethernet", "medium-ip", "medium-ieee802154",
   "phy-raw_socket", "phy-tuntap_interface",
-  "proto-ipv4", "proto-igmp", "proto-dhcpv4", "proto-ipv6",
+  "proto-ipv4", "proto-igmp", "proto-dhcpv4", "proto-ipv6", "proto-sixlowpan",
   "socket-raw", "socket-icmp", "socket-udp", "socket-tcp", "socket-dhcpv4",
   "async"
 ]
@@ -110,5 +116,9 @@ required-features = ["std", "medium-ethernet", "medium-ip", "phy-tuntap_interfac
 name = "dhcp_client"
 required-features = ["std", "medium-ethernet", "medium-ip", "phy-tuntap_interface", "proto-ipv4", "proto-dhcpv4", "socket-raw"]
 
+[[example]]
+name = "sixlowpan"
+required-features = ["std", "medium-ieee802154", "phy-raw_socket", "proto-sixlowpan", "socket-udp"]
+
 [profile.release]
 debug = 2

examples/benchmark.rs

@@ -100,7 +100,7 @@ fn main() {
     let mut builder = InterfaceBuilder::new(device).ip_addrs(ip_addrs);
     if medium == Medium::Ethernet {
         builder = builder
-            .ethernet_addr(ethernet_addr)
+            .hardware_addr(ethernet_addr.into())
             .neighbor_cache(neighbor_cache);
     }
     let mut iface = builder.finalize();

examples/client.rs

@@ -47,7 +47,7 @@ fn main() {
         .routes(routes);
     if medium == Medium::Ethernet {
         builder = builder
-            .ethernet_addr(ethernet_addr)
+            .hardware_addr(ethernet_addr.into())
             .neighbor_cache(neighbor_cache);
     }
     let mut iface = builder.finalize();

examples/dhcp_client.rs

@@ -39,7 +39,7 @@ fn main() {
         .routes(routes);
     if medium == Medium::Ethernet {
         builder = builder
-            .ethernet_addr(ethernet_addr)
+            .hardware_addr(ethernet_addr.into())
             .neighbor_cache(neighbor_cache);
     }
     let mut iface = builder.finalize();

examples/httpclient.rs

@@ -53,7 +53,7 @@ fn main() {
         .routes(routes);
     if medium == Medium::Ethernet {
         builder = builder
-            .ethernet_addr(ethernet_addr)
+            .hardware_addr(ethernet_addr.into())
             .neighbor_cache(neighbor_cache);
     }
     let mut iface = builder.finalize();

examples/loopback.rs

@@ -95,7 +95,7 @@ fn main() {
 
     let mut ip_addrs = [IpCidr::new(IpAddress::v4(127, 0, 0, 1), 8)];
     let mut iface = InterfaceBuilder::new(device)
-        .ethernet_addr(EthernetAddress::default())
+        .hardware_addr(EthernetAddress::default().into())
         .neighbor_cache(neighbor_cache)
         .ip_addrs(ip_addrs)
         .finalize();

examples/multicast.rs

@@ -38,7 +38,7 @@ fn main() {
     let ip_addr = IpCidr::new(IpAddress::from(local_addr), 24);
     let mut ipv4_multicast_storage = [None; 1];
     let mut iface = InterfaceBuilder::new(device)
-        .ethernet_addr(ethernet_addr)
+        .hardware_addr(ethernet_addr.into())
         .neighbor_cache(neighbor_cache)
         .ip_addrs([ip_addr])
         .ipv4_multicast_groups(&mut ipv4_multicast_storage[..])

examples/ping.rs

@@ -132,7 +132,7 @@ fn main() {
         .routes(routes);
     if medium == Medium::Ethernet {
         builder = builder
-            .ethernet_addr(ethernet_addr)
+            .hardware_addr(ethernet_addr.into())
             .neighbor_cache(neighbor_cache);
     }
     let mut iface = builder.finalize();

examples/server.rs

@@ -59,7 +59,7 @@ fn main() {
     let mut builder = InterfaceBuilder::new(device).ip_addrs(ip_addrs);
     if medium == Medium::Ethernet {
         builder = builder
-            .ethernet_addr(ethernet_addr)
+            .hardware_addr(ethernet_addr.into())
             .neighbor_cache(neighbor_cache);
     }
     let mut iface = builder.finalize();

examples/sixlowpan.rs

@@ -0,0 +1,134 @@
+//! 6lowpan exmaple
+//!
+//! This example is designed to run using the Linux ieee802154/6lowpan support,
+//! using mac802154_hwsim.
+//!
+//! mac802154_hwsim allows you to create multiple "virtual" radios and specify
+//! which is in range with which. This is very useful for testing without
+//! needing real hardware. By default it creates two interfaces `wpan0` and
+//! `wpan1` that are in range with each other. You can customize this with
+//! the `wpan-hwsim` tool.
+//!
+//! We'll configure Linux to speak 6lowpan on `wpan0`, and leave `wpan1`
+//! unconfigured so smoltcp can use it with a raw socket.
+//!
+//! # Setup
+//!
+//!     modprobe mac802154_hwsim
+//!
+//!     ip link set wpan0 down
+//!     ip link set wpan1 down
+//!     iwpan dev wpan0 set pan_id 0xbeef
+//!     iwpan dev wpan1 set pan_id 0xbeef
+//!     ip link add link wpan0 name lowpan0 type lowpan
+//!     ip link set wpan0 up
+//!     ip link set wpan1 up
+//!     ip link set lowpan0 up
+//!
+//! # Running
+//!
+//! Run it with `sudo ./target/debug/examples/sixlowpan`.
+//!
+//! You can set wireshark to sniff on interface `wpan0` to see the packets.
+//!
+//! Ping it with `ping fe80::180b:4242:4242:4242%lowpan0`.
+//!
+//! Speak UDP with `nc -uv fe80::180b:4242:4242:4242%lowpan0 6969`.
+//!
+//! # Teardown
+//!
+//!     rmmod mac802154_hwsim
+//!
+
+mod utils;
+
+use log::debug;
+use std::collections::BTreeMap;
+use std::os::unix::io::AsRawFd;
+use std::str;
+
+use smoltcp::iface::{InterfaceBuilder, NeighborCache};
+use smoltcp::phy::{wait as phy_wait, Medium, RawSocket};
+use smoltcp::socket::SocketSet;
+use smoltcp::socket::{UdpPacketMetadata, UdpSocket, UdpSocketBuffer};
+use smoltcp::time::Instant;
+use smoltcp::wire::{Ieee802154Pan, IpAddress, IpCidr};
+
+fn main() {
+    utils::setup_logging("");
+
+    let (mut opts, mut free) = utils::create_options();
+    utils::add_middleware_options(&mut opts, &mut free);
+
+    let mut matches = utils::parse_options(&opts, free);
+
+    let device = RawSocket::new("wpan1", Medium::Ieee802154).unwrap();
+
+    let fd = device.as_raw_fd();
+    let device = utils::parse_middleware_options(&mut matches, device, /*loopback=*/ false);
+
+    let neighbor_cache = NeighborCache::new(BTreeMap::new());
+
+    let udp_rx_buffer = UdpSocketBuffer::new(vec![UdpPacketMetadata::EMPTY], vec![0; 64]);
+    let udp_tx_buffer = UdpSocketBuffer::new(vec![UdpPacketMetadata::EMPTY], vec![0; 128]);
+    let udp_socket = UdpSocket::new(udp_rx_buffer, udp_tx_buffer);
+
+    let ieee802154_addr = smoltcp::wire::Ieee802154Address::Extended([
+        0x1a, 0x0b, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42,
+    ]);
+    let ip_addrs = [IpCidr::new(
+        IpAddress::v6(0xfe80, 0, 0, 0, 0x180b, 0x4242, 0x4242, 0x4242),
+        64,
+    )];
+
+    let mut builder = InterfaceBuilder::new(device)
+        .ip_addrs(ip_addrs)
+        .pan_id(Ieee802154Pan(0xbeef));
+    builder = builder
+        .hardware_addr(ieee802154_addr.into())
+        .neighbor_cache(neighbor_cache);
+    let mut iface = builder.finalize();
+
+    let mut sockets = SocketSet::new(vec![]);
+    let udp_handle = sockets.add(udp_socket);
+
+    loop {
+        let timestamp = Instant::now();
+        match iface.poll(&mut sockets, timestamp) {
+            Ok(_) => {}
+            Err(e) => {
+                debug!("poll error: {}", e);
+            }
+        }
+
+        // udp:6969: respond "hello"
+        {
+            let mut socket = sockets.get::<UdpSocket>(udp_handle);
+            if !socket.is_open() {
+                socket.bind(6969).unwrap()
+            }
+
+            let client = match socket.recv() {
+                Ok((data, endpoint)) => {
+                    debug!(
+                        "udp:6969 recv data: {:?} from {}",
+                        str::from_utf8(data).unwrap(),
+                        endpoint
+                    );
+                    Some(endpoint)
+                }
+                Err(_) => None,
+            };
+            if let Some(endpoint) = client {
+                let data = b"hello\n";
+                debug!(
+                    "udp:6969 send data: {:?}",
+                    str::from_utf8(data.as_ref()).unwrap()
+                );
+                socket.send_slice(data, endpoint).unwrap();
+            }
+        }
+
+        phy_wait(fd, iface.poll_delay(&sockets, timestamp)).expect("wait error");
+    }
+}

examples/tcpdump.rs

@@ -7,7 +7,7 @@ use std::os::unix::io::AsRawFd;
 
 fn main() {
     let ifname = env::args().nth(1).unwrap();
-    let mut socket = RawSocket::new(ifname.as_ref()).unwrap();
+    let mut socket = RawSocket::new(ifname.as_ref(), smoltcp::phy::Medium::Ethernet).unwrap();
     loop {
         phy_wait(socket.as_raw_fd(), None).unwrap();
         let (rx_token, _) = socket.receive().unwrap();

examples/utils.rs

@@ -12,7 +12,6 @@ use std::process;
 use std::str::{self, FromStr};
 use std::time::{SystemTime, UNIX_EPOCH};
 
-use smoltcp::phy::RawSocket;
 #[cfg(feature = "phy-tuntap_interface")]
 use smoltcp::phy::TunTapInterface;
 use smoltcp::phy::{Device, FaultInjector, Medium, Tracer};
@@ -112,11 +111,6 @@ pub fn parse_tuntap_options(matches: &mut Matches) -> TunTapInterface {
     }
 }
 
-pub fn parse_raw_socket_options(matches: &mut Matches) -> RawSocket {
-    let interface = matches.free.remove(0);
-    RawSocket::new(&interface).unwrap()
-}
-
 pub fn add_middleware_options(opts: &mut Options, _free: &mut Vec<&str>) {
     opts.optopt("", "pcap", "Write a packet capture file", "FILE");
     opts.optopt(

src/iface/mod.rs

@@ -4,19 +4,27 @@ The `iface` module deals with the *network interfaces*. It filters incoming fram
 provides lookup and caching of hardware addresses, and handles management packets.
 */
 
-#[cfg(any(feature = "medium-ethernet", feature = "medium-ip"))]
+#[cfg(any(
+    feature = "medium-ethernet",
+    feature = "medium-ip",
+    feature = "medium-ieee802154"
+))]
 mod interface;
-#[cfg(feature = "medium-ethernet")]
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
 mod neighbor;
 mod route;
 
-#[cfg(feature = "medium-ethernet")]
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
 pub(crate) use self::neighbor::Answer as NeighborAnswer;
-#[cfg(feature = "medium-ethernet")]
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
 pub use self::neighbor::Cache as NeighborCache;
-#[cfg(feature = "medium-ethernet")]
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
 pub use self::neighbor::Neighbor;
 pub use self::route::{Route, Routes};
 
-#[cfg(any(feature = "medium-ethernet", feature = "medium-ip"))]
+#[cfg(any(
+    feature = "medium-ethernet",
+    feature = "medium-ip",
+    feature = "medium-ieee802154"
+))]
 pub use self::interface::{Interface, InterfaceBuilder};

src/iface/neighbor.rs

@@ -4,7 +4,7 @@
 use managed::ManagedMap;
 
 use crate::time::{Duration, Instant};
-use crate::wire::{EthernetAddress, IpAddress};
+use crate::wire::{HardwareAddress, IpAddress};
 
 /// A cached neighbor.
 ///
@@ -13,7 +13,7 @@ use crate::wire::{EthernetAddress, IpAddress};
 #[derive(Debug, Clone, Copy)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct Neighbor {
-    hardware_addr: EthernetAddress,
+    hardware_addr: HardwareAddress,
     expires_at: Instant,
 }
 
@@ -22,7 +22,7 @@ pub struct Neighbor {
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub(crate) enum Answer {
     /// The neighbor address is in the cache and not expired.
-    Found(EthernetAddress),
+    Found(HardwareAddress),
     /// The neighbor address is not in the cache, or has expired.
     NotFound,
     /// The neighbor address is not in the cache, or has expired,
@@ -115,7 +115,7 @@ impl<'a> Cache<'a> {
     pub fn fill(
         &mut self,
         protocol_addr: IpAddress,
-        hardware_addr: EthernetAddress,
+        hardware_addr: HardwareAddress,
         timestamp: Instant,
     ) {
         debug_assert!(protocol_addr.is_unicast());
@@ -196,9 +196,7 @@ impl<'a> Cache<'a> {
     }
 
     pub(crate) fn lookup(&self, protocol_addr: &IpAddress, timestamp: Instant) -> Answer {
-        if protocol_addr.is_broadcast() {
-            return Answer::Found(EthernetAddress::BROADCAST);
-        }
+        assert!(protocol_addr.is_unicast());
 
         if let Some(&Neighbor {
             expires_at,
@@ -228,10 +226,12 @@ mod test {
     use crate::wire::ip::test::{MOCK_IP_ADDR_1, MOCK_IP_ADDR_2, MOCK_IP_ADDR_3, MOCK_IP_ADDR_4};
     use std::collections::BTreeMap;
 
-    const HADDR_A: EthernetAddress = EthernetAddress([0, 0, 0, 0, 0, 1]);
-    const HADDR_B: EthernetAddress = EthernetAddress([0, 0, 0, 0, 0, 2]);
-    const HADDR_C: EthernetAddress = EthernetAddress([0, 0, 0, 0, 0, 3]);
-    const HADDR_D: EthernetAddress = EthernetAddress([0, 0, 0, 0, 0, 4]);
+    use crate::wire::EthernetAddress;
+
+    const HADDR_A: HardwareAddress = HardwareAddress::Ethernet(EthernetAddress([0, 0, 0, 0, 0, 1]));
+    const HADDR_B: HardwareAddress = HardwareAddress::Ethernet(EthernetAddress([0, 0, 0, 0, 0, 2]));
+    const HADDR_C: HardwareAddress = HardwareAddress::Ethernet(EthernetAddress([0, 0, 0, 0, 0, 3]));
+    const HADDR_D: HardwareAddress = HardwareAddress::Ethernet(EthernetAddress([0, 0, 0, 0, 0, 4]));
 
     #[test]
     fn test_fill() {

src/lib.rs

@@ -97,8 +97,12 @@ compile_error!("at least one socket needs to be enabled"); */
 #[cfg(any(feature = "std", feature = "alloc"))]
 extern crate alloc;
 
-#[cfg(not(any(feature = "proto-ipv4", feature = "proto-ipv6")))]
-compile_error!("You must enable at least one of the following features: proto-ipv4, proto-ipv6");
+#[cfg(not(any(
+    feature = "proto-ipv4",
+    feature = "proto-ipv6",
+    feature = "proto-sixlowpan"
+)))]
+compile_error!("You must enable at least one of the following features: proto-ipv4, proto-ipv6, proto-sixlowpan");
 
 #[cfg(all(
     feature = "socket",
@@ -113,9 +117,13 @@ compile_error!("If you enable the socket feature, you must enable at least one o
 
 #[cfg(all(
     feature = "socket",
-    not(any(feature = "medium-ethernet", feature = "medium-ip",))
+    not(any(
+        feature = "medium-ethernet",
+        feature = "medium-ip",
+        feature = "medium-ieee802154",
+    ))
 ))]
-compile_error!("If you enable the socket feature, you must enable at least one of the following features: medium-ip, medium-ethernet");
+compile_error!("If you enable the socket feature, you must enable at least one of the following features: medium-ip, medium-ethernet, medium-ieee802154");
 
 #[cfg(all(feature = "defmt", feature = "log"))]
 compile_error!("You must enable at most one of the following features: defmt, log");
@@ -174,6 +182,10 @@ pub enum Error {
     /// An incoming packet was recognized but contradicted internal state.
     /// E.g. a TCP packet addressed to a socket that doesn't exist.
     Dropped,
+
+    /// An incoming packet was recognized but some parts are not supported by smoltcp.
+    /// E.g. some bit configuration in a packet header is not supported, but is defined in an RFC.
+    NotSupported,
 }
 
 #[cfg(feature = "std")]
@@ -195,6 +207,7 @@ impl fmt::Display for Error {
             Error::Fragmented => write!(f, "fragmented packet"),
             Error::Malformed => write!(f, "malformed packet"),
             Error::Dropped => write!(f, "dropped by socket"),
+            Error::NotSupported => write!(f, "not supported by smoltcp"),
         }
     }
 }

src/phy/mod.rs

@@ -254,6 +254,8 @@ impl DeviceCapabilities {
             }
             #[cfg(feature = "medium-ip")]
             Medium::Ip => self.max_transmission_unit,
+            #[cfg(feature = "medium-ieee802154")]
+            Medium::Ieee802154 => self.max_transmission_unit, // TODO(thvdveld): what is the MTU for Medium::IEEE802
         }
     }
 }
@@ -275,15 +277,32 @@ pub enum Medium {
     /// Examples of devices of this type are the Linux `tun`, PPP interfaces, VPNs in tun (layer 3) mode.
     #[cfg(feature = "medium-ip")]
     Ip,
+
+    #[cfg(feature = "medium-ieee802154")]
+    Ieee802154,
 }
 
 impl Default for Medium {
     fn default() -> Medium {
         #[cfg(feature = "medium-ethernet")]
         return Medium::Ethernet;
-        #[cfg(all(feature = "medium-ip", not(feature = "medium-ethernet")))]
+        #[cfg(all(
+            feature = "medium-ip",
+            not(feature = "medium-ethernet"),
+            not(feature = "medium-ieee802154")
+        ))]
         return Medium::Ip;
-        #[cfg(all(not(feature = "medium-ip"), not(feature = "medium-ethernet")))]
+        #[cfg(all(
+            feature = "medium-ieee802154",
+            not(feature = "medium-ip"),
+            not(feature = "medium-ethernet")
+        ))]
+        return Medium::Ieee802154;
+        #[cfg(all(
+            not(feature = "medium-ip"),
+            not(feature = "medium-ethernet"),
+            not(feature = "medium-ieee802154")
+        ))]
         panic!("No medium enabled");
     }
 }

src/phy/pcap_writer.rs

@@ -15,6 +15,8 @@ enum_with_unknown! {
         Ethernet =   1,
         /// IPv4 or IPv6 packets (depending on the version field)
         Ip       = 101,
+        /// IEEE 802.15.4 packets with FCS included.
+        Ieee802154WithFcs = 195,
     }
 }
 
@@ -133,6 +135,8 @@ impl<D: for<'a> Device<'a>, S: PcapSink> PcapWriter<D, S> {
             Medium::Ip => PcapLinkType::Ip,
             #[cfg(feature = "medium-ethernet")]
             Medium::Ethernet => PcapLinkType::Ethernet,
+            #[cfg(feature = "medium-ieee802154")]
+            Medium::Ieee802154 => PcapLinkType::Ieee802154WithFcs,
         };
         sink.global_header(link_type);
         PcapWriter {

src/phy/raw_socket.rs

@@ -11,6 +11,7 @@ use crate::Result;
 /// A socket that captures or transmits the complete frame.
 #[derive(Debug)]
 pub struct RawSocket {
+    medium: Medium,
     lower: Rc<RefCell<sys::RawSocketDesc>>,
     mtu: usize,
 }
@@ -26,11 +27,21 @@ impl RawSocket {
     ///
     /// This requires superuser privileges or a corresponding capability bit
     /// set on the executable.
-    pub fn new(name: &str) -> io::Result<RawSocket> {
-        let mut lower = sys::RawSocketDesc::new(name)?;
+    pub fn new(name: &str, medium: Medium) -> io::Result<RawSocket> {
+        let mut lower = sys::RawSocketDesc::new(name, medium)?;
         lower.bind_interface()?;
-        let mtu = lower.interface_mtu()?;
+
+        let mut mtu = lower.interface_mtu()?;
+
+        #[cfg(feature = "medium-ethernet")]
+        if medium == Medium::Ethernet {
+            // SIOCGIFMTU returns the IP MTU (typically 1500 bytes.)
+            // smoltcp counts the entire Ethernet packet in the MTU, so add the Ethernet header size to it.
+            mtu += crate::wire::EthernetFrame::<&[u8]>::header_len()
+        }
+
         Ok(RawSocket {
+            medium,
             lower: Rc::new(RefCell::new(lower)),
             mtu: mtu,
         })
@@ -44,7 +55,7 @@ impl<'a> Device<'a> for RawSocket {
     fn capabilities(&self) -> DeviceCapabilities {
         DeviceCapabilities {
             max_transmission_unit: self.mtu,
-            medium: Medium::Ethernet,
+            medium: self.medium,
             ..DeviceCapabilities::default()
         }
     }

src/phy/sys/bpf.rs

@@ -5,6 +5,7 @@ use std::os::unix::io::{AsRawFd, RawFd};
 use libc;
 
 use super::{ifreq, ifreq_for};
+use crate::phy::Medium;
 use crate::wire::ETHERNET_HEADER_LEN;
 
 /// set interface
@@ -67,7 +68,7 @@ fn open_device() -> io::Result<libc::c_int> {
 }
 
 impl BpfDevice {
-    pub fn new(name: &str) -> io::Result<BpfDevice> {
+    pub fn new(name: &str, _medium: Medium) -> io::Result<BpfDevice> {
         Ok(BpfDevice {
             fd: open_device()?,
             ifreq: ifreq_for(name),

src/phy/sys/linux.rs

@@ -3,6 +3,7 @@
 pub const SIOCGIFMTU: libc::c_ulong = 0x8921;
 pub const SIOCGIFINDEX: libc::c_ulong = 0x8933;
 pub const ETH_P_ALL: libc::c_short = 0x0003;
+pub const ETH_P_IEEE802154: libc::c_short = 0x00F6;
 
 pub const TUNSETIFF: libc::c_ulong = 0x400454CA;
 pub const IFF_TUN: libc::c_int = 0x0001;

src/phy/sys/raw_socket.rs

@@ -1,10 +1,12 @@
 use super::*;
+use crate::phy::Medium;
 use crate::wire::EthernetFrame;
 use std::os::unix::io::{AsRawFd, RawFd};
 use std::{io, mem};
 
 #[derive(Debug)]
 pub struct RawSocketDesc {
+    protocol: libc::c_short,
     lower: libc::c_int,
     ifreq: ifreq,
 }
@@ -16,12 +18,21 @@ impl AsRawFd for RawSocketDesc {
 }
 
 impl RawSocketDesc {
-    pub fn new(name: &str) -> io::Result<RawSocketDesc> {
+    pub fn new(name: &str, medium: Medium) -> io::Result<RawSocketDesc> {
+        let protocol = match medium {
+            #[cfg(feature = "medium-ethernet")]
+            Medium::Ethernet => imp::ETH_P_ALL,
+            #[cfg(feature = "medium-ip")]
+            Medium::Ip => imp::ETH_P_ALL,
+            #[cfg(feature = "medium-ieee802154")]
+            Medium::Ieee802154 => imp::ETH_P_IEEE802154,
+        };
+
         let lower = unsafe {
             let lower = libc::socket(
                 libc::AF_PACKET,
                 libc::SOCK_RAW | libc::SOCK_NONBLOCK,
-                imp::ETH_P_ALL.to_be() as i32,
+                protocol.to_be() as i32,
             );
             if lower == -1 {
                 return Err(io::Error::last_os_error());
@@ -30,7 +41,8 @@ impl RawSocketDesc {
         };
 
         Ok(RawSocketDesc {
-            lower: lower,
+            protocol,
+            lower,
             ifreq: ifreq_for(name),
         })
     }
@@ -46,7 +58,7 @@ impl RawSocketDesc {
     pub fn bind_interface(&mut self) -> io::Result<()> {
         let sockaddr = libc::sockaddr_ll {
             sll_family: libc::AF_PACKET as u16,
-            sll_protocol: imp::ETH_P_ALL.to_be() as u16,
+            sll_protocol: self.protocol.to_be() as u16,
             sll_ifindex: ifreq_ioctl(self.lower, &mut self.ifreq, imp::SIOCGIFINDEX)?,
             sll_hatype: 1,
             sll_pkttype: 0,

src/phy/sys/tuntap_interface.rs

@@ -42,6 +42,8 @@ impl TunTapInterfaceDesc {
             Medium::Ip => imp::IFF_TUN,
             #[cfg(feature = "medium-ethernet")]
             Medium::Ethernet => imp::IFF_TAP,
+            #[cfg(feature = "medium-ieee802154")]
+            Medium::Ieee802154 => todo!(),
         };
         self.ifreq.ifr_data = mode | imp::IFF_NO_PI;
         ifreq_ioctl(self.lower, &mut self.ifreq, imp::TUNSETIFF).map(|_| ())
@@ -72,6 +74,8 @@ impl TunTapInterfaceDesc {
             Medium::Ip => ip_mtu,
             #[cfg(feature = "medium-ethernet")]
             Medium::Ethernet => ip_mtu + EthernetFrame::<&[u8]>::header_len(),
+            #[cfg(feature = "medium-ieee802154")]
+            Medium::Ieee802154 => todo!(),
         };
 
         Ok(mtu)

src/phy/tracer.rs

@@ -190,6 +190,8 @@ impl<'a> fmt::Display for Packet<'a> {
                 }
                 _ => f.write_str("unrecognized IP version"),
             },
+            #[cfg(feature = "medium-ieee802154")]
+            Medium::Ieee802154 => Ok(()), // XXX
         }
     }
 }

src/socket/dhcpv4.rs

@@ -2,6 +2,7 @@ use crate::socket::SocketHandle;
 use crate::socket::{Context, SocketMeta};
 use crate::time::{Duration, Instant};
 use crate::wire::dhcpv4::field as dhcpv4_field;
+use crate::wire::HardwareAddress;
 use crate::wire::{
     DhcpMessageType, DhcpPacket, DhcpRepr, IpAddress, IpProtocol, Ipv4Address, Ipv4Cidr, Ipv4Repr,
     UdpRepr, DHCP_CLIENT_PORT, DHCP_MAX_DNS_SERVER_COUNT, DHCP_SERVER_PORT, UDP_HEADER_LEN,
@@ -218,7 +219,13 @@ impl Dhcpv4Socket {
                 return Ok(());
             }
         };
-        if dhcp_repr.client_hardware_address != cx.ethernet_address.unwrap() {
+        let hardware_addr = if let Some(HardwareAddress::Ethernet(addr)) = cx.hardware_addr {
+            addr
+        } else {
+            return Err(Error::Malformed);
+        };
+
+        if dhcp_repr.client_hardware_address != hardware_addr {
             return Ok(());
         }
         if dhcp_repr.transaction_id != self.transaction_id {
@@ -381,7 +388,11 @@ impl Dhcpv4Socket {
     {
         // note: Dhcpv4Socket is only usable in ethernet mediums, so the
         // unwrap can never fail.
-        let ethernet_addr = cx.ethernet_address.unwrap();
+        let ethernet_addr = if let Some(HardwareAddress::Ethernet(addr)) = cx.hardware_addr {
+            addr
+        } else {
+            return Err(Error::Malformed);
+        };
 
         // Worst case biggest IPv4 header length.
         // 0x0f * 4 = 60 bytes.

src/socket/mod.rs

@@ -187,8 +187,13 @@ from_socket!(Dhcpv4Socket, Dhcpv4);
 #[derive(Clone, Debug)]
 pub(crate) struct Context {
     pub now: Instant,
-    #[cfg(all(feature = "medium-ethernet", feature = "socket-dhcpv4"))]
-    pub ethernet_address: Option<crate::wire::EthernetAddress>,
+    #[cfg(all(
+        any(feature = "medium-ethernet", feature = "medium-ieee802154"),
+        feature = "socket-dhcpv4"
+    ))]
+    pub hardware_addr: Option<crate::wire::HardwareAddress>,
+    #[cfg(feature = "medium-ieee802154")]
+    pub pan_id: Option<crate::wire::Ieee802154Pan>,
     pub caps: DeviceCapabilities,
 }
 
@@ -215,10 +220,16 @@ impl Context {
             #[cfg(not(feature = "medium-ethernet"))]
             max_transmission_unit: 1500,
         },
-        #[cfg(all(feature = "medium-ethernet", feature = "socket-dhcpv4"))]
-        ethernet_address: Some(crate::wire::EthernetAddress([
-            0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
-        ])),
+        #[cfg(all(
+            any(feature = "medium-ethernet", feature = "medium-ieee802154"),
+            feature = "socket-dhcpv4"
+        ))]
+        hardware_addr: Some(crate::wire::HardwareAddress::Ethernet(
+            crate::wire::EthernetAddress([0x02, 0x02, 0x02, 0x02, 0x02, 0x02]),
+        )),
         now: Instant::from_millis_const(0),
+
+        #[cfg(feature = "medium-ieee802154")]
+        pan_id: Some(crate::wire::Ieee802154Pan(0xabcd)),
     };
 }

src/socket/set.rs

@@ -69,9 +69,7 @@ impl<'a> Set<'a> {
         }
 
         match self.sockets {
-            ManagedSlice::Borrowed(_) => {
-                panic!("adding a socket to a full SocketSet")
-            }
+            ManagedSlice::Borrowed(_) => panic!("adding a socket to a full SocketSet"),
             #[cfg(any(feature = "std", feature = "alloc"))]
             ManagedSlice::Owned(ref mut sockets) => {
                 sockets.push(None);

src/wire/icmpv6.rs

@@ -4,7 +4,7 @@ use core::{cmp, fmt};
 use crate::phy::ChecksumCapabilities;
 use crate::wire::ip::checksum;
 use crate::wire::MldRepr;
-#[cfg(feature = "medium-ethernet")]
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
 use crate::wire::NdiscRepr;
 use crate::wire::{IpAddress, IpProtocol, Ipv6Packet, Ipv6Repr};
 use crate::{Error, Result};
@@ -532,7 +532,7 @@ pub enum Repr<'a> {
         seq_no: u16,
         data: &'a [u8],
     },
-    #[cfg(feature = "medium-ethernet")]
+    #[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
     Ndisc(NdiscRepr<'a>),
     Mld(MldRepr<'a>),
 }
@@ -617,7 +617,7 @@ impl<'a> Repr<'a> {
                 seq_no: packet.echo_seq_no(),
                 data: packet.payload(),
             }),
-            #[cfg(feature = "medium-ethernet")]
+            #[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
             (msg_type, 0) if msg_type.is_ndisc() => NdiscRepr::parse(packet).map(Repr::Ndisc),
             (msg_type, 0) if msg_type.is_mld() => MldRepr::parse(packet).map(Repr::Mld),
             _ => Err(Error::Unrecognized),
@@ -636,7 +636,7 @@ impl<'a> Repr<'a> {
             &Repr::EchoRequest { data, .. } | &Repr::EchoReply { data, .. } => {
                 field::ECHO_SEQNO.end + data.len()
             }
-            #[cfg(feature = "medium-ethernet")]
+            #[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
             &Repr::Ndisc(ndisc) => ndisc.buffer_len(),
             &Repr::Mld(mld) => mld.buffer_len(),
         }
@@ -730,7 +730,7 @@ impl<'a> Repr<'a> {
                 packet.payload_mut()[..data_len].copy_from_slice(&data[..data_len])
             }
 
-            #[cfg(feature = "medium-ethernet")]
+            #[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
             Repr::Ndisc(ndisc) => ndisc.emit(packet),
 
             Repr::Mld(mld) => mld.emit(packet),

src/wire/ieee802154.rs

@@ -0,0 +1,897 @@
+use core::fmt;
+
+use byteorder::{ByteOrder, LittleEndian};
+
+use crate::wire::ipv6::Address as Ipv6Address;
+use crate::Error;
+use crate::Result;
+
+const CRC_TABLE: [u16; 256] = [
+    0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, 0x8c48, 0x9dc1, 0xaf5a, 0xbed3,
+    0xca6c, 0xdbe5, 0xe97e, 0xf8f7, 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+    0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, 0x2102, 0x308b, 0x0210, 0x1399,
+    0x6726, 0x76af, 0x4434, 0x55bd, 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+    0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, 0xbdcb, 0xac42, 0x9ed9, 0x8f50,
+    0xfbef, 0xea66, 0xd8fd, 0xc974, 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+    0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, 0x5285, 0x430c, 0x7197, 0x601e,
+    0x14a1, 0x0528, 0x37b3, 0x263a, 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+    0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, 0xef4e, 0xfec7, 0xcc5c, 0xddd5,
+    0xa96a, 0xb8e3, 0x8a78, 0x9bf1, 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+    0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, 0x8408, 0x9581, 0xa71a, 0xb693,
+    0xc22c, 0xd3a5, 0xe13e, 0xf0b7, 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+    0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, 0x18c1, 0x0948, 0x3bd3, 0x2a5a,
+    0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+    0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, 0xb58b, 0xa402, 0x9699, 0x8710,
+    0xf3af, 0xe226, 0xd0bd, 0xc134, 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+    0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, 0x4a44, 0x5bcd, 0x6956, 0x78df,
+    0x0c60, 0x1de9, 0x2f72, 0x3efb, 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+    0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, 0xe70e, 0xf687, 0xc41c, 0xd595,
+    0xa12a, 0xb0a3, 0x8238, 0x93b1, 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+    0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, 0x7bc7, 0x6a4e, 0x58d5, 0x495c,
+    0x3de3, 0x2c6a, 0x1ef1, 0x0f78,
+];
+
+pub fn calculate_crc(buffer: &[u8]) -> u16 {
+    fn crc_byte(crc: u16, c: u8) -> u16 {
+        (crc >> 8) ^ CRC_TABLE[((crc ^ (c as u16)) & 0xff) as usize]
+    }
+
+    let mut crc = 0;
+
+    for b in buffer {
+        crc = crc_byte(crc, *b);
+    }
+
+    crc
+}
+
+enum_with_unknown! {
+    /// IEEE 802.15.4 frame type.
+    pub enum FrameType(u8) {
+        Beacon = 0b000,
+        Data = 0b001,
+        Acknowledgement = 0b010,
+        MacCommand = 0b011,
+        Multipurpose = 0b101,
+        FragmentOrFrak = 0b110,
+        Extended = 0b111,
+    }
+}
+
+impl fmt::Display for FrameType {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            FrameType::Beacon => write!(f, "Beacon"),
+            FrameType::Data => write!(f, "Data"),
+            FrameType::Acknowledgement => write!(f, "Ack"),
+            FrameType::MacCommand => write!(f, "MAC command"),
+            FrameType::Multipurpose => write!(f, "Multipurpose"),
+            FrameType::FragmentOrFrak => write!(f, "FragmentOrFrak"),
+            FrameType::Extended => write!(f, "Extended"),
+            FrameType::Unknown(id) => write!(f, "0b{:04b}", id),
+        }
+    }
+}
+enum_with_unknown! {
+    /// IEEE 802.15.4 addressing mode for destination and source addresses.
+    pub enum AddressingMode(u8) {
+        Absent    = 0b00,
+        Short     = 0b10,
+        Extended  = 0b11,
+    }
+}
+
+impl AddressingMode {
+    /// Return the size in octets of the address.
+    fn size(&self) -> usize {
+        match self {
+            AddressingMode::Absent => 0,
+            AddressingMode::Short => 2,
+            AddressingMode::Extended => 8,
+            AddressingMode::Unknown(_) => 0, // TODO(thvdveld): what do we need to here?
+        }
+    }
+}
+
+impl fmt::Display for AddressingMode {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            AddressingMode::Absent => write!(f, "Absent"),
+            AddressingMode::Short => write!(f, "Short"),
+            AddressingMode::Extended => write!(f, "Extended"),
+            AddressingMode::Unknown(id) => write!(f, "0b{:04b}", id),
+        }
+    }
+}
+
+/// A IEEE 802.15.4 PAN.
+#[derive(Debug, Hash, PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
+pub struct Pan(pub u16);
+
+impl Pan {
+    pub const BROADCAST: Self = Self(0xffff);
+
+    /// Return the PAN ID as bytes.
+    pub fn as_bytes(&self) -> [u8; 2] {
+        let mut pan = [0u8; 2];
+        LittleEndian::write_u16(&mut pan, self.0);
+        pan
+    }
+}
+
+/// A IEEE 802.15.4 address.
+#[derive(Debug, Hash, PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
+pub enum Address {
+    Absent,
+    Short([u8; 2]),
+    Extended([u8; 8]),
+}
+
+impl Address {
+    /// The broadcast address.
+    pub const BROADCAST: Address = Address::Short([0xff; 2]);
+
+    /// Query whether the address is an unicast address.
+    pub fn is_unicast(&self) -> bool {
+        !self.is_broadcast()
+    }
+
+    /// Query whether this address is the broadcast address.
+    pub fn is_broadcast(&self) -> bool {
+        *self == Self::BROADCAST
+    }
+
+    fn short_from_bytes(a: [u8; 2]) -> Self {
+        Self::Short(a)
+    }
+
+    fn extended_from_bytes(a: [u8; 8]) -> Self {
+        Self::Extended(a)
+    }
+
+    pub fn from_bytes(a: &[u8]) -> Self {
+        if a.len() == 2 {
+            let mut b = [0u8; 2];
+            b.copy_from_slice(a);
+            Address::Short(b)
+        } else if a.len() == 8 {
+            let mut b = [0u8; 8];
+            b.copy_from_slice(a);
+            Address::Extended(b)
+        } else {
+            panic!("Not an IEEE802.15.4 address");
+        }
+    }
+
+    pub fn as_bytes(&self) -> &[u8] {
+        match self {
+            Address::Absent => &[],
+            Address::Short(value) => value,
+            Address::Extended(value) => value,
+        }
+    }
+
+    /// Convert the extended address to an Extended Unique Identifier (EUI-64)
+    pub fn as_eui_64(&self) -> Option<[u8; 8]> {
+        match self {
+            Address::Absent | Address::Short(_) => None,
+            Address::Extended(value) => {
+                let mut bytes = [0; 8];
+                bytes.copy_from_slice(&value[..]);
+
+                bytes[0] ^= 1 << 1;
+
+                Some(bytes)
+            }
+        }
+    }
+
+    /// Convert an extended address to a link-local IPv6 address using the EUI-64 format from
+    /// RFC2464.
+    pub fn as_link_local_address(&self) -> Option<Ipv6Address> {
+        let mut bytes = [0; 16];
+        bytes[0] = 0xfe;
+        bytes[1] = 0x80;
+        bytes[8..].copy_from_slice(&self.as_eui_64()?);
+
+        Some(Ipv6Address::from_bytes(&bytes))
+    }
+}
+
+impl fmt::Display for Address {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::Absent => write!(f, "not-present"),
+            Self::Short(bytes) => write!(f, "{:02x}-{:02x}", bytes[0], bytes[1]),
+            Self::Extended(bytes) => write!(
+                f,
+                "{:02x}-{:02x}-{:02x}-{:02x}-{:02x}-{:02x}-{:02x}-{:02x}",
+                bytes[0], bytes[1], bytes[2], bytes[3], bytes[4], bytes[5], bytes[6], bytes[7]
+            ),
+        }
+    }
+}
+
+enum_with_unknown! {
+    /// IEEE 802.15.4 addressing mode for destination and source addresses.
+    pub enum FrameVersion(u8) {
+        Ieee802154_2003 = 0b00,
+        Ieee802154_2006 = 0b01,
+        Ieee802154 = 0b10,
+    }
+}
+
+/// A read/write wrapper around an IEEE 802.15.4 frame buffer.
+#[derive(Debug, Clone)]
+pub struct Frame<T: AsRef<[u8]>> {
+    buffer: T,
+}
+
+mod field {
+    use crate::wire::field::*;
+
+    pub const FRAMECONTROL: Field = 0..2;
+    pub const SEQUENCE_NUMBER: usize = 2;
+    pub const ADDRESSING: Rest = 3..;
+}
+
+macro_rules! fc_bit_field {
+    ($field:ident, $bit:literal) => {
+        #[inline]
+        pub fn $field(&self) -> bool {
+            let data = self.buffer.as_ref();
+            let raw = LittleEndian::read_u16(&data[field::FRAMECONTROL]);
+
+            ((raw >> $bit) & 0b1) == 0b1
+        }
+    };
+}
+
+macro_rules! set_fc_bit_field {
+    ($field:ident, $bit:literal) => {
+        #[inline]
+        pub fn $field(&mut self, val: bool) {
+            let data = &mut self.buffer.as_mut()[field::FRAMECONTROL];
+            let mut raw = LittleEndian::read_u16(data);
+            raw |= ((val as u16) << $bit);
+
+            data.copy_from_slice(&raw.to_le_bytes());
+        }
+    };
+}
+
+impl<T: AsRef<[u8]>> Frame<T> {
+    /// Input a raw octet buffer with Ethernet frame structure.
+    pub fn new_unchecked(buffer: T) -> Frame<T> {
+        Frame { buffer }
+    }
+
+    /// Shorthand for a combination of [new_unchecked] and [check_len].
+    ///
+    /// [new_unchecked]: #method.new_unchecked
+    /// [check_len]: #method.check_len
+    pub fn new_checked(buffer: T) -> Result<Frame<T>> {
+        let packet = Self::new_unchecked(buffer);
+        packet.check_len()?;
+
+        if matches!(packet.dst_addressing_mode(), AddressingMode::Unknown(_)) {
+            return Err(Error::Malformed);
+        }
+
+        if matches!(packet.src_addressing_mode(), AddressingMode::Unknown(_)) {
+            return Err(Error::Malformed);
+        }
+
+        Ok(packet)
+    }
+
+    /// Ensure that no accessor method will panic if called.
+    /// Returns `Err(Error::Truncated)` if the buffer is too short.
+    pub fn check_len(&self) -> Result<()> {
+        if self.buffer.as_ref().is_empty() {
+            Err(Error::Truncated)
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Consumes the frame, returning the underlying buffer.
+    pub fn into_inner(self) -> T {
+        self.buffer
+    }
+
+    /// Return the FrameType field.
+    #[inline]
+    pub fn frame_type(&self) -> FrameType {
+        let data = self.buffer.as_ref();
+        let raw = LittleEndian::read_u16(&data[field::FRAMECONTROL]);
+        let ft = (raw & 0b11) as u8;
+        FrameType::from(ft)
+    }
+
+    fc_bit_field!(security_enabled, 3);
+    fc_bit_field!(frame_pending, 4);
+    fc_bit_field!(ack_request, 5);
+    fc_bit_field!(pan_id_compression, 6);
+
+    fc_bit_field!(sequence_number_suppression, 8);
+    fc_bit_field!(ie_present, 9);
+
+    /// Return the destination addressing mode.
+    #[inline]
+    pub fn dst_addressing_mode(&self) -> AddressingMode {
+        let data = self.buffer.as_ref();
+        let raw = LittleEndian::read_u16(&data[field::FRAMECONTROL]);
+        let am = ((raw >> 10) & 0b11) as u8;
+        AddressingMode::from(am)
+    }
+
+    /// Return the frame version.
+    #[inline]
+    pub fn frame_version(&self) -> FrameVersion {
+        let data = self.buffer.as_ref();
+        let raw = LittleEndian::read_u16(&data[field::FRAMECONTROL]);
+        let fv = ((raw >> 12) & 0b11) as u8;
+        FrameVersion::from(fv)
+    }
+
+    /// Return the source addressing mode.
+    #[inline]
+    pub fn src_addressing_mode(&self) -> AddressingMode {
+        let data = self.buffer.as_ref();
+        let raw = LittleEndian::read_u16(&data[field::FRAMECONTROL]);
+        let am = ((raw >> 14) & 0b11) as u8;
+        AddressingMode::from(am)
+    }
+
+    /// Return the sequence number of the frame.
+    #[inline]
+    pub fn sequence_number(&self) -> Option<u8> {
+        match self.frame_type() {
+            FrameType::Beacon
+            | FrameType::Data
+            | FrameType::Acknowledgement
+            | FrameType::MacCommand
+            | FrameType::Multipurpose => {
+                let data = self.buffer.as_ref();
+                let raw = data[field::SEQUENCE_NUMBER];
+                Some(raw)
+            }
+            FrameType::Extended | FrameType::FragmentOrFrak | FrameType::Unknown(_) => None,
+        }
+    }
+
+    /// Return the addressing fields.
+    #[inline]
+    fn addressing_fields(&self) -> Option<&[u8]> {
+        match self.frame_type() {
+            FrameType::Beacon
+            | FrameType::Data
+            | FrameType::MacCommand
+            | FrameType::Multipurpose => (),
+            FrameType::Acknowledgement if self.frame_version() == FrameVersion::Ieee802154 => (),
+            FrameType::Acknowledgement
+            | FrameType::Extended
+            | FrameType::FragmentOrFrak
+            | FrameType::Unknown(_) => return None,
+        }
+
+        let mut offset = 2;
+
+        // Calculate the size of the addressing field.
+        offset += self.dst_addressing_mode().size();
+        offset += self.src_addressing_mode().size();
+
+        if !self.pan_id_compression() {
+            offset += 2;
+        }
+
+        Some(&self.buffer.as_ref()[field::ADDRESSING][..offset])
+    }
+
+    /// Return the destination PAN field.
+    #[inline]
+    pub fn dst_pan_id(&self) -> Option<Pan> {
+        let addressing_fields = self.addressing_fields()?;
+        match self.dst_addressing_mode() {
+            AddressingMode::Absent => None,
+            AddressingMode::Short | AddressingMode::Extended => {
+                Some(Pan(LittleEndian::read_u16(&addressing_fields[0..2])))
+            }
+            AddressingMode::Unknown(_) => None,
+        }
+    }
+
+    /// Return the destination address field.
+    #[inline]
+    pub fn dst_addr(&self) -> Option<Address> {
+        let addressing_fields = self.addressing_fields()?;
+        match self.dst_addressing_mode() {
+            AddressingMode::Absent => Some(Address::Absent),
+            AddressingMode::Short => {
+                let mut raw = [0u8; 2];
+                raw.clone_from_slice(&addressing_fields[2..4]);
+                raw.reverse();
+                Some(Address::short_from_bytes(raw))
+            }
+            AddressingMode::Extended => {
+                let mut raw = [0u8; 8];
+                raw.clone_from_slice(&addressing_fields[2..10]);
+                raw.reverse();
+                Some(Address::extended_from_bytes(raw))
+            }
+            AddressingMode::Unknown(_) => None,
+        }
+    }
+
+    /// Return the destination PAN field.
+    #[inline]
+    pub fn src_pan_id(&self) -> Option<Pan> {
+        if self.pan_id_compression() {
+            return None;
+        }
+
+        let addressing_fields = self.addressing_fields()?;
+        let offset = self.dst_addressing_mode().size() + 2;
+
+        match self.src_addressing_mode() {
+            AddressingMode::Absent => None,
+            AddressingMode::Short | AddressingMode::Extended => Some(Pan(LittleEndian::read_u16(
+                &addressing_fields[offset..offset + 2],
+            ))),
+            AddressingMode::Unknown(_) => None,
+        }
+    }
+
+    /// Return the source address field.
+    #[inline]
+    pub fn src_addr(&self) -> Option<Address> {
+        let addressing_fields = self.addressing_fields()?;
+        let mut offset = match self.dst_addressing_mode() {
+            AddressingMode::Absent => 0,
+            AddressingMode::Short => 2,
+            AddressingMode::Extended => 8,
+            _ => return None, // TODO(thvdveld): what do we do here?
+        } + 2;
+
+        if !self.pan_id_compression() {
+            offset += 2;
+        }
+
+        match self.src_addressing_mode() {
+            AddressingMode::Absent => Some(Address::Absent),
+            AddressingMode::Short => {
+                let mut raw = [0u8; 2];
+                raw.clone_from_slice(&addressing_fields[offset..offset + 2]);
+                raw.reverse();
+                Some(Address::short_from_bytes(raw))
+            }
+            AddressingMode::Extended => {
+                let mut raw = [0u8; 8];
+                raw.clone_from_slice(&addressing_fields[offset..offset + 8]);
+                raw.reverse();
+                Some(Address::extended_from_bytes(raw))
+            }
+            AddressingMode::Unknown(_) => None,
+        }
+    }
+
+    /// Return the Auxilliary Security Header Field
+    #[inline]
+    pub fn aux_security_header(&self) -> Option<&[u8]> {
+        match self.frame_type() {
+            FrameType::Beacon
+            | FrameType::Data
+            | FrameType::MacCommand
+            | FrameType::Multipurpose => (),
+            FrameType::Acknowledgement if self.frame_version() == FrameVersion::Ieee802154 => (),
+            FrameType::Acknowledgement
+            | FrameType::Extended
+            | FrameType::FragmentOrFrak
+            | FrameType::Unknown(_) => return None,
+        }
+
+        if !self.security_enabled() {
+            return None;
+        }
+
+        net_debug!("Auxilliary security header is currently not supported.");
+        None
+    }
+}
+
+impl<'a, T: AsRef<[u8]> + ?Sized> Frame<&'a T> {
+    /// Return a pointer to the payload.
+    #[inline]
+    pub fn payload(&self) -> Option<&'a [u8]> {
+        match self.frame_type() {
+            FrameType::Data => {
+                let data = &self.buffer.as_ref()[field::ADDRESSING];
+                let offset = self.addressing_fields().unwrap().len();
+
+                Some(&data[offset..])
+            }
+            _ => None,
+        }
+    }
+}
+
+impl<T: AsRef<[u8]> + AsMut<[u8]>> Frame<T> {
+    /// Set the frame type.
+    #[inline]
+    pub fn set_frame_type(&mut self, frame_type: FrameType) {
+        let data = &mut self.buffer.as_mut()[field::FRAMECONTROL];
+        let mut raw = LittleEndian::read_u16(data);
+
+        raw = (raw & !(0b111)) | (u8::from(frame_type) as u16 & 0b111);
+        data.copy_from_slice(&raw.to_le_bytes());
+    }
+
+    set_fc_bit_field!(set_security_enabled, 3);
+    set_fc_bit_field!(set_frame_pending, 4);
+    set_fc_bit_field!(set_ack_request, 5);
+    set_fc_bit_field!(set_pan_id_compression, 6);
+
+    /// Set the frame version.
+    #[inline]
+    pub fn set_frame_version(&mut self, version: FrameVersion) {
+        let data = &mut self.buffer.as_mut()[field::FRAMECONTROL];
+        let mut raw = LittleEndian::read_u16(data);
+
+        raw = (raw & !(0b11 << 12)) | ((u8::from(version) as u16 & 0b11) << 12);
+        data.copy_from_slice(&raw.to_le_bytes());
+    }
+
+    /// Set the frame sequence number.
+    #[inline]
+    pub fn set_sequence_number(&mut self, value: u8) {
+        let data = self.buffer.as_mut();
+        data[field::SEQUENCE_NUMBER] = value;
+    }
+
+    /// Set the destination PAN ID.
+    #[inline]
+    pub fn set_dst_pan_id(&mut self, value: Pan) {
+        // NOTE the destination addressing mode must be different than Absent.
+        // This is the reason why we set it to Extended.
+        self.set_dst_addressing_mode(AddressingMode::Extended);
+
+        let data = self.buffer.as_mut();
+        data[field::ADDRESSING][..2].copy_from_slice(&value.as_bytes());
+    }
+
+    /// Set the destination address.
+    #[inline]
+    pub fn set_dst_addr(&mut self, mut value: Address) {
+        match value {
+            Address::Absent => self.set_dst_addressing_mode(AddressingMode::Absent),
+            Address::Short(ref mut value) => {
+                value.reverse();
+                self.set_dst_addressing_mode(AddressingMode::Short);
+                let data = self.buffer.as_mut();
+                data[field::ADDRESSING][2..2 + 2].copy_from_slice(value);
+                value.reverse();
+            }
+            Address::Extended(ref mut value) => {
+                value.reverse();
+                self.set_dst_addressing_mode(AddressingMode::Extended);
+                let data = &mut self.buffer.as_mut()[field::ADDRESSING];
+                data[2..2 + 8].copy_from_slice(value);
+                value.reverse();
+            }
+        }
+    }
+
+    /// Set the destination addressing mode.
+    #[inline]
+    fn set_dst_addressing_mode(&mut self, value: AddressingMode) {
+        let data = &mut self.buffer.as_mut()[field::FRAMECONTROL];
+        let mut raw = LittleEndian::read_u16(data);
+
+        raw = (raw & !(0b11 << 10)) | ((u8::from(value) as u16 & 0b11) << 10);
+        data.copy_from_slice(&raw.to_le_bytes());
+    }
+
+    /// Set the source PAN ID.
+    #[inline]
+    pub fn set_src_pan_id(&mut self, value: Pan) {
+        let offset = match self.dst_addressing_mode() {
+            AddressingMode::Absent => 0,
+            AddressingMode::Short => 2,
+            AddressingMode::Extended => 8,
+            _ => unreachable!(),
+        } + 2;
+
+        let data = &mut self.buffer.as_mut()[field::ADDRESSING];
+        data[offset..offset + 2].copy_from_slice(&value.as_bytes());
+    }
+
+    /// Set the source address.
+    #[inline]
+    pub fn set_src_addr(&mut self, mut value: Address) {
+        let offset = match self.dst_addressing_mode() {
+            AddressingMode::Absent => 0,
+            AddressingMode::Short => 2,
+            AddressingMode::Extended => 8,
+            _ => unreachable!(),
+        } + 2;
+
+        let offset = offset + if self.pan_id_compression() { 0 } else { 2 };
+
+        match value {
+            Address::Absent => self.set_src_addressing_mode(AddressingMode::Absent),
+            Address::Short(ref mut value) => {
+                value.reverse();
+                self.set_src_addressing_mode(AddressingMode::Short);
+                let data = &mut self.buffer.as_mut()[field::ADDRESSING];
+                data[offset..offset + 2].copy_from_slice(value);
+                value.reverse();
+            }
+            Address::Extended(ref mut value) => {
+                value.reverse();
+                self.set_src_addressing_mode(AddressingMode::Extended);
+                let data = &mut self.buffer.as_mut()[field::ADDRESSING];
+                data[offset..offset + 8].copy_from_slice(value);
+                value.reverse();
+            }
+        }
+    }
+
+    /// Set the source addressing mode.
+    #[inline]
+    fn set_src_addressing_mode(&mut self, value: AddressingMode) {
+        let data = &mut self.buffer.as_mut()[field::FRAMECONTROL];
+        let mut raw = LittleEndian::read_u16(data);
+
+        raw = (raw & !(0b11 << 14)) | ((u8::from(value) as u16 & 0b11) << 14);
+        data.copy_from_slice(&raw.to_le_bytes());
+    }
+
+    /// Return a mutable pointer to the payload.
+    #[inline]
+    pub fn payload_mut(&mut self) -> Option<&mut [u8]> {
+        match self.frame_type() {
+            FrameType::Data => {
+                let mut start_offset = 3;
+                start_offset += self.addressing_fields().unwrap().len();
+
+                let data = self.buffer.as_mut();
+                let end_offset = start_offset + data.len() - 2;
+                Some(&mut data[start_offset..end_offset])
+            }
+            _ => None,
+        }
+    }
+}
+
+impl<T: AsRef<[u8]>> fmt::Display for Frame<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "IEEE802.15.4 frame type={} seq={:2x?} dst_pan={:x?} dest={:x?} src_pan={:?} src={:x?}",
+            self.frame_type(),
+            self.sequence_number(),
+            self.dst_pan_id(),
+            self.dst_addr(),
+            self.src_pan_id(),
+            self.src_addr(),
+        )
+    }
+}
+
+/// A high-level representation of an IEEE802.15.4 frame.
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub struct Repr {
+    pub frame_type: FrameType,
+    pub security_enabled: bool,
+    pub frame_pending: bool,
+    pub ack_request: bool,
+    pub sequence_number: Option<u8>,
+    pub pan_id_compression: bool,
+    pub frame_version: FrameVersion,
+    pub dst_pan_id: Option<Pan>,
+    pub dst_addr: Option<Address>,
+    pub src_pan_id: Option<Pan>,
+    pub src_addr: Option<Address>,
+}
+
+impl Repr {
+    /// Parse an IEEE 802.15.4 frame and return a high-level representation.
+    pub fn parse<T: AsRef<[u8]> + ?Sized>(packet: &Frame<&T>) -> Result<Repr> {
+        // Ensure the basic accessors will work.
+        packet.check_len()?;
+
+        Ok(Repr {
+            frame_type: packet.frame_type(),
+            security_enabled: packet.security_enabled(),
+            frame_pending: packet.frame_pending(),
+            ack_request: packet.ack_request(),
+            sequence_number: packet.sequence_number(),
+            pan_id_compression: packet.pan_id_compression(),
+            frame_version: packet.frame_version(),
+            dst_pan_id: packet.dst_pan_id(),
+            dst_addr: packet.dst_addr(),
+            src_pan_id: packet.src_pan_id(),
+            src_addr: packet.src_addr(),
+        })
+    }
+
+    /// Return the length of a buffer required to hold a packet with the payload of a given length.
+    #[inline]
+    pub fn buffer_len(&self) -> usize {
+        3 + 2
+            + match self.dst_addr {
+                Some(Address::Absent) | None => 0,
+                Some(Address::Short(_)) => 2,
+                Some(Address::Extended(_)) => 8,
+            }
+            + if !self.pan_id_compression { 2 } else { 0 }
+            + match self.src_addr {
+                Some(Address::Absent) | None => 0,
+                Some(Address::Short(_)) => 2,
+                Some(Address::Extended(_)) => 8,
+            }
+    }
+
+    /// Emit a high-level representation into an IEEE802.15.4 frame.
+    pub fn emit<T: AsRef<[u8]> + AsMut<[u8]>>(&self, frame: &mut Frame<T>) {
+        frame.set_frame_type(self.frame_type);
+        frame.set_security_enabled(self.security_enabled);
+        frame.set_frame_pending(self.frame_pending);
+        frame.set_ack_request(self.ack_request);
+        frame.set_pan_id_compression(self.pan_id_compression);
+        frame.set_frame_version(self.frame_version);
+
+        if let Some(sequence_number) = self.sequence_number {
+            frame.set_sequence_number(sequence_number);
+        }
+
+        if let Some(dst_pan_id) = self.dst_pan_id {
+            frame.set_dst_pan_id(dst_pan_id);
+        }
+        if let Some(dst_addr) = self.dst_addr {
+            frame.set_dst_addr(dst_addr);
+        }
+
+        if !self.pan_id_compression && self.src_pan_id.is_some() {
+            frame.set_src_pan_id(self.src_pan_id.unwrap());
+        }
+
+        if let Some(src_addr) = self.src_addr {
+            frame.set_src_addr(src_addr);
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::Result;
+
+    #[test]
+    fn test_broadcast() {
+        assert!(Address::BROADCAST.is_broadcast());
+        assert!(!Address::BROADCAST.is_unicast());
+    }
+
+    #[test]
+    fn prepare_frame() {
+        let mut buffer = [0u8; 128];
+
+        let repr = Repr {
+            frame_type: FrameType::Data,
+            security_enabled: false,
+            frame_pending: false,
+            ack_request: true,
+            pan_id_compression: true,
+            frame_version: FrameVersion::Ieee802154,
+            sequence_number: Some(1),
+            dst_pan_id: Some(Pan(0xabcd)),
+            dst_addr: Some(Address::BROADCAST),
+            src_pan_id: None,
+            src_addr: Some(Address::Extended([
+                0xc7, 0xd9, 0xb5, 0x14, 0x00, 0x4b, 0x12, 0x00,
+            ])),
+        };
+
+        let buffer_len = repr.buffer_len();
+
+        let mut frame = Frame::new_unchecked(&mut buffer[..buffer_len]);
+        repr.emit(&mut frame);
+
+        println!("{:2x?}", frame);
+
+        assert_eq!(frame.frame_type(), FrameType::Data);
+        assert!(!frame.security_enabled());
+        assert!(!frame.frame_pending());
+        assert!(frame.ack_request());
+        assert!(frame.pan_id_compression());
+        assert_eq!(frame.frame_version(), FrameVersion::Ieee802154);
+        assert_eq!(frame.sequence_number(), Some(1));
+        assert_eq!(frame.dst_pan_id(), Some(Pan(0xabcd)));
+        assert_eq!(frame.dst_addr(), Some(Address::BROADCAST));
+        assert_eq!(frame.src_pan_id(), None);
+        assert_eq!(
+            frame.src_addr(),
+            Some(Address::Extended([
+                0xc7, 0xd9, 0xb5, 0x14, 0x00, 0x4b, 0x12, 0x00
+            ]))
+        );
+    }
+
+    macro_rules! vector_test {
+        ($name:ident $bytes:expr ; $($test_method:ident -> $expected:expr,)*) => {
+            #[test]
+            #[allow(clippy::bool_assert_comparison)]
+            fn $name() -> Result<()> {
+                let frame = &$bytes;
+                let frame = Frame::new_checked(frame)?;
+
+                $(
+                    assert_eq!(frame.$test_method(), $expected, stringify!($test_method));
+                )*
+
+                Ok(())
+            }
+        }
+    }
+
+    vector_test! {
+        extended_addr
+        [
+            0b0000_0001, 0b1100_1100, // frame control
+            0b0, // seq
+            0xcd, 0xab, // pan id
+            0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, // dst addr
+            0x03, 0x04, // pan id
+            0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x02, // src addr
+        ];
+        frame_type -> FrameType::Data,
+        dst_addr -> Some(Address::Extended([0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00])),
+        src_addr -> Some(Address::Extended([0x02, 0x00, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00])),
+        dst_pan_id -> Some(Pan(0xabcd)),
+    }
+
+    vector_test! {
+        short_addr
+        [
+            0x01, 0x98,             // frame control
+            0x00,                   // sequence number
+            0x34, 0x12, 0x78, 0x56, // PAN identifier and address of destination
+            0x34, 0x12, 0xbc, 0x9a, // PAN identifier and address of source
+        ];
+        frame_type -> FrameType::Data,
+        security_enabled -> false,
+        frame_pending -> false,
+        ack_request -> false,
+        pan_id_compression -> false,
+        dst_addressing_mode -> AddressingMode::Short,
+        frame_version -> FrameVersion::Ieee802154_2006,
+        src_addressing_mode -> AddressingMode::Short,
+        dst_pan_id -> Some(Pan(0x1234)),
+        dst_addr -> Some(Address::Short([0x56, 0x78])),
+        src_pan_id -> Some(Pan(0x1234)),
+        src_addr -> Some(Address::Short([0x9a, 0xbc])),
+    }
+
+    vector_test! {
+        zolertia_remote
+        [
+            0x41, 0xd8, // frame control
+            0x01, // sequence number
+            0xcd, 0xab, // Destination PAN id
+            0xff, 0xff, // Short destination address
+            0xc7, 0xd9, 0xb5, 0x14, 0x00, 0x4b, 0x12, 0x00, // Extended source address
+            0x2b, 0x00, 0x00, 0x00, // payload
+        ];
+        frame_type -> FrameType::Data,
+        security_enabled -> false,
+        frame_pending -> false,
+        ack_request -> false,
+        pan_id_compression -> true,
+        dst_addressing_mode -> AddressingMode::Short,
+        frame_version -> FrameVersion::Ieee802154_2006,
+        src_addressing_mode -> AddressingMode::Extended,
+        //payload -> Some(&[0x2b, 0x00, 0x00, 0x00]),
+    }
+}

src/wire/igmp.rs

@@ -337,23 +337,19 @@ impl<'a> fmt::Display for Repr {
                 max_resp_time,
                 group_addr,
                 version,
-            } => {
-                write!(
-                    f,
-                    "IGMP membership query max_resp_time={} group_addr={} version={:?}",
-                    max_resp_time, group_addr, version
-                )
-            }
+            } => write!(
+                f,
+                "IGMP membership query max_resp_time={} group_addr={} version={:?}",
+                max_resp_time, group_addr, version
+            ),
             Repr::MembershipReport {
                 group_addr,
                 version,
-            } => {
-                write!(
-                    f,
-                    "IGMP membership report group_addr={} version={:?}",
-                    group_addr, version
-                )
-            }
+            } => write!(
+                f,
+                "IGMP membership report group_addr={} version={:?}",
+                group_addr, version
+            ),
             Repr::LeaveGroup { group_addr } => {
                 write!(f, "IGMP leave group group_addr={})", group_addr)
             }

src/wire/ipv6.rs

@@ -183,12 +183,10 @@ impl Address {
     /// unicast.
     pub fn solicited_node(&self) -> Address {
         assert!(self.is_unicast());
-        let mut bytes = [
-            0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x00,
-        ];
-        bytes[14..].copy_from_slice(&self.0[14..]);
-        Address(bytes)
+        Address([
+            0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xFF,
+            self.0[13], self.0[14], self.0[15],
+        ])
     }
 }
 

src/wire/mod.rs

@@ -89,6 +89,8 @@ mod icmp;
 mod icmpv4;
 #[cfg(feature = "proto-ipv6")]
 mod icmpv6;
+#[cfg(feature = "medium-ieee802154")]
+pub mod ieee802154;
 #[cfg(feature = "proto-igmp")]
 mod igmp;
 pub(crate) mod ip;
@@ -106,13 +108,23 @@ mod ipv6option;
 mod ipv6routing;
 #[cfg(feature = "proto-ipv6")]
 mod mld;
-#[cfg(all(feature = "proto-ipv6", feature = "medium-ethernet"))]
+#[cfg(all(
+    feature = "proto-ipv6",
+    any(feature = "medium-ethernet", feature = "medium-ieee802154")
+))]
 mod ndisc;
-#[cfg(all(feature = "proto-ipv6", feature = "medium-ethernet"))]
+#[cfg(all(
+    feature = "proto-ipv6",
+    any(feature = "medium-ethernet", feature = "medium-ieee802154")
+))]
 mod ndiscoption;
+#[cfg(all(feature = "proto-sixlowpan", feature = "medium-ieee802154"))]
+mod sixlowpan;
 mod tcp;
 mod udp;
 
+use crate::{phy::Medium, Error};
+
 pub use self::pretty_print::PrettyPrinter;
 
 #[cfg(feature = "medium-ethernet")]
@@ -126,6 +138,24 @@ pub use self::arp::{
     Hardware as ArpHardware, Operation as ArpOperation, Packet as ArpPacket, Repr as ArpRepr,
 };
 
+#[cfg(all(feature = "proto-sixlowpan", feature = "medium-ieee802154"))]
+pub use self::sixlowpan::{
+    iphc::{Packet as SixlowpanIphcPacket, Repr as SixlowpanIphcRepr},
+    nhc::{
+        ExtensionHeaderPacket as SixlowpanExtHeaderPacket,
+        ExtensionHeaderRepr as SixlowpanExtHeaderRepr, Packet as SixlowpanNhcPacket,
+        UdpNhcRepr as SixlowpanUdpRepr, UdpPacket as SixlowpanUdpPacket,
+    },
+    NextHeader as SixlowpanNextHeader,
+};
+
+#[cfg(feature = "medium-ieee802154")]
+pub use self::ieee802154::{
+    Address as Ieee802154Address, AddressingMode as Ieee802154AddressingMode,
+    Frame as Ieee802154Frame, FrameType as Ieee802154FrameType,
+    FrameVersion as Ieee802154FrameVersion, Pan as Ieee802154Pan, Repr as Ieee802154Repr,
+};
+
 pub use self::ip::{
     Address as IpAddress, Cidr as IpCidr, Endpoint as IpEndpoint, Protocol as IpProtocol,
     Repr as IpRepr, Version as IpVersion,
@@ -177,12 +207,18 @@ pub use self::icmpv6::{
 #[cfg(any(feature = "proto-ipv4", feature = "proto-ipv6"))]
 pub use self::icmp::Repr as IcmpRepr;
 
-#[cfg(all(feature = "proto-ipv6", feature = "medium-ethernet"))]
+#[cfg(all(
+    feature = "proto-ipv6",
+    any(feature = "medium-ethernet", feature = "medium-ieee802154")
+))]
 pub use self::ndisc::{
     NeighborFlags as NdiscNeighborFlags, Repr as NdiscRepr, RouterFlags as NdiscRouterFlags,
 };
 
-#[cfg(all(feature = "proto-ipv6", feature = "medium-ethernet"))]
+#[cfg(all(
+    feature = "proto-ipv6",
+    any(feature = "medium-ethernet", feature = "medium-ieee802154")
+))]
 pub use self::ndiscoption::{
     NdiscOption, PrefixInfoFlags as NdiscPrefixInfoFlags,
     PrefixInformation as NdiscPrefixInformation, RedirectedHeader as NdiscRedirectedHeader,
@@ -205,3 +241,172 @@ pub use self::dhcpv4::{
     CLIENT_PORT as DHCP_CLIENT_PORT, MAX_DNS_SERVER_COUNT as DHCP_MAX_DNS_SERVER_COUNT,
     SERVER_PORT as DHCP_SERVER_PORT,
 };
+
+/// Representation of an hardware address, such as an Ethernet address or an IEEE802.15.4 address.
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum HardwareAddress {
+    #[cfg(feature = "medium-ethernet")]
+    Ethernet(EthernetAddress),
+    #[cfg(feature = "medium-ieee802154")]
+    Ieee802154(Ieee802154Address),
+}
+
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
+impl HardwareAddress {
+    pub fn as_bytes(&self) -> &[u8] {
+        match self {
+            #[cfg(feature = "medium-ethernet")]
+            HardwareAddress::Ethernet(addr) => addr.as_bytes(),
+            #[cfg(feature = "medium-ieee802154")]
+            HardwareAddress::Ieee802154(addr) => addr.as_bytes(),
+        }
+    }
+
+    /// Query wether the address is an unicast address.
+    pub fn is_unicast(&self) -> bool {
+        match self {
+            #[cfg(feature = "medium-ethernet")]
+            HardwareAddress::Ethernet(addr) => addr.is_unicast(),
+            #[cfg(feature = "medium-ieee802154")]
+            HardwareAddress::Ieee802154(addr) => addr.is_unicast(),
+        }
+    }
+
+    /// Query wether the address is a broadcast address.
+    pub fn is_broadcast(&self) -> bool {
+        match self {
+            #[cfg(feature = "medium-ethernet")]
+            HardwareAddress::Ethernet(addr) => addr.is_broadcast(),
+            #[cfg(feature = "medium-ieee802154")]
+            HardwareAddress::Ieee802154(addr) => addr.is_broadcast(),
+        }
+    }
+}
+
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
+impl core::fmt::Display for HardwareAddress {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        match self {
+            #[cfg(feature = "medium-ethernet")]
+            HardwareAddress::Ethernet(addr) => write!(f, "{}", addr),
+            #[cfg(feature = "medium-ieee802154")]
+            HardwareAddress::Ieee802154(addr) => write!(f, "{}", addr),
+        }
+    }
+}
+
+#[cfg(feature = "medium-ethernet")]
+impl From<EthernetAddress> for HardwareAddress {
+    fn from(addr: EthernetAddress) -> Self {
+        HardwareAddress::Ethernet(addr)
+    }
+}
+
+#[cfg(feature = "medium-ieee802154")]
+impl From<Ieee802154Address> for HardwareAddress {
+    fn from(addr: Ieee802154Address) -> Self {
+        HardwareAddress::Ieee802154(addr)
+    }
+}
+
+#[cfg(not(feature = "medium-ieee802154"))]
+pub const MAX_HARDWARE_ADDRESS_LEN: usize = 6;
+#[cfg(feature = "medium-ieee802154")]
+pub const MAX_HARDWARE_ADDRESS_LEN: usize = 8;
+
+/// Unparsed hardware address.
+///
+/// Used to make NDISC parsing agnostic of the hardware medium in use.
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub struct RawHardwareAddress {
+    len: u8,
+    data: [u8; MAX_HARDWARE_ADDRESS_LEN],
+}
+
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
+impl RawHardwareAddress {
+    pub fn from_bytes(addr: &[u8]) -> Self {
+        let mut data = [0u8; MAX_HARDWARE_ADDRESS_LEN];
+        data[..addr.len()].copy_from_slice(addr);
+
+        Self {
+            len: addr.len() as u8,
+            data,
+        }
+    }
+
+    pub fn as_bytes(&self) -> &[u8] {
+        &self.data[..self.len as usize]
+    }
+
+    pub fn len(&self) -> usize {
+        self.len as usize
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.len == 0
+    }
+
+    pub fn parse(&self, medium: Medium) -> Result<HardwareAddress, Error> {
+        match medium {
+            #[cfg(feature = "medium-ethernet")]
+            Medium::Ethernet => {
+                if self.len() < 6 {
+                    return Err(Error::Malformed);
+                }
+                Ok(HardwareAddress::Ethernet(EthernetAddress::from_bytes(
+                    self.as_bytes(),
+                )))
+            }
+            #[cfg(feature = "medium-ieee802154")]
+            Medium::Ieee802154 => {
+                if self.len() < 8 {
+                    return Err(Error::Malformed);
+                }
+                Ok(HardwareAddress::Ieee802154(Ieee802154Address::from_bytes(
+                    self.as_bytes(),
+                )))
+            }
+            #[cfg(feature = "medium-ip")]
+            Medium::Ip => unreachable!(),
+        }
+    }
+}
+
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
+impl core::fmt::Display for RawHardwareAddress {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        for (i, &b) in self.as_bytes().iter().enumerate() {
+            if i != 0 {
+                write!(f, ":")?;
+            }
+            write!(f, "{:02x}", b)?;
+        }
+        Ok(())
+    }
+}
+
+#[cfg(feature = "medium-ethernet")]
+impl From<EthernetAddress> for RawHardwareAddress {
+    fn from(addr: EthernetAddress) -> Self {
+        Self::from_bytes(addr.as_bytes())
+    }
+}
+
+#[cfg(feature = "medium-ieee802154")]
+impl From<Ieee802154Address> for RawHardwareAddress {
+    fn from(addr: Ieee802154Address) -> Self {
+        Self::from_bytes(addr.as_bytes())
+    }
+}
+
+#[cfg(any(feature = "medium-ethernet", feature = "medium-ieee802154"))]
+impl From<HardwareAddress> for RawHardwareAddress {
+    fn from(addr: HardwareAddress) -> Self {
+        Self::from_bytes(addr.as_bytes())
+    }
+}

src/wire/ndisc.rs

@@ -4,7 +4,8 @@ use byteorder::{ByteOrder, NetworkEndian};
 use crate::time::Duration;
 use crate::wire::icmpv6::{field, Message, Packet};
 use crate::wire::Ipv6Address;
-use crate::wire::{EthernetAddress, Ipv6Packet, Ipv6Repr};
+use crate::wire::RawHardwareAddress;
+use crate::wire::{Ipv6Packet, Ipv6Repr};
 use crate::wire::{NdiscOption, NdiscOptionRepr, NdiscOptionType};
 use crate::wire::{NdiscPrefixInformation, NdiscRedirectedHeader};
 use crate::{Error, Result};
@@ -193,7 +194,7 @@ impl<T: AsRef<[u8]> + AsMut<[u8]>> Packet<T> {
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Repr<'a> {
     RouterSolicit {
-        lladdr: Option<EthernetAddress>,
+        lladdr: Option<RawHardwareAddress>,
     },
     RouterAdvert {
         hop_limit: u8,
@@ -201,23 +202,23 @@ pub enum Repr<'a> {
         router_lifetime: Duration,
         reachable_time: Duration,
         retrans_time: Duration,
-        lladdr: Option<EthernetAddress>,
+        lladdr: Option<RawHardwareAddress>,
         mtu: Option<u32>,
         prefix_info: Option<NdiscPrefixInformation>,
     },
     NeighborSolicit {
         target_addr: Ipv6Address,
-        lladdr: Option<EthernetAddress>,
+        lladdr: Option<RawHardwareAddress>,
     },
     NeighborAdvert {
         flags: NeighborFlags,
         target_addr: Ipv6Address,
-        lladdr: Option<EthernetAddress>,
+        lladdr: Option<RawHardwareAddress>,
     },
     Redirect {
         target_addr: Ipv6Address,
         dest_addr: Ipv6Address,
-        lladdr: Option<EthernetAddress>,
+        lladdr: Option<RawHardwareAddress>,
         redirected_hdr: Option<NdiscRedirectedHeader<'a>>,
     },
 }
@@ -372,10 +373,11 @@ impl<'a> Repr<'a> {
                 field::RETRANS_TM.end + offset
             }
             &Repr::NeighborSolicit { lladdr, .. } | &Repr::NeighborAdvert { lladdr, .. } => {
-                match lladdr {
-                    Some(_) => field::TARGET_ADDR.end + 8,
-                    None => field::TARGET_ADDR.end,
+                let mut offset = field::TARGET_ADDR.end;
+                if let Some(lladdr) = lladdr {
+                    offset += NdiscOptionRepr::SourceLinkLayerAddr(lladdr).buffer_len();
                 }
+                offset
             }
             &Repr::Redirect {
                 lladdr,
@@ -429,8 +431,9 @@ impl<'a> Repr<'a> {
                 let mut offset = 0;
                 if let Some(lladdr) = lladdr {
                     let mut opt_pkt = NdiscOption::new_unchecked(packet.payload_mut());
-                    NdiscOptionRepr::SourceLinkLayerAddr(lladdr).emit(&mut opt_pkt);
-                    offset += 8;
+                    let opt = NdiscOptionRepr::SourceLinkLayerAddr(lladdr);
+                    opt.emit(&mut opt_pkt);
+                    offset += opt.buffer_len();
                 }
                 if let Some(mtu) = mtu {
                     let mut opt_pkt =
@@ -509,6 +512,7 @@ mod test {
     use super::*;
     use crate::phy::ChecksumCapabilities;
     use crate::wire::ip::test::{MOCK_IP_ADDR_1, MOCK_IP_ADDR_2};
+    use crate::wire::EthernetAddress;
     use crate::wire::Icmpv6Repr;
 
     static ROUTER_ADVERT_BYTES: [u8; 24] = [
@@ -524,7 +528,7 @@ mod test {
             router_lifetime: Duration::from_secs(900),
             reachable_time: Duration::from_millis(900),
             retrans_time: Duration::from_millis(900),
-            lladdr: Some(EthernetAddress([0x52, 0x54, 0x00, 0x12, 0x34, 0x56])),
+            lladdr: Some(EthernetAddress([0x52, 0x54, 0x00, 0x12, 0x34, 0x56]).into()),
             mtu: None,
             prefix_info: None,
         })

src/wire/ndiscoption.rs

@@ -3,9 +3,11 @@ use byteorder::{ByteOrder, NetworkEndian};
 use core::fmt;
 
 use crate::time::Duration;
-use crate::wire::{EthernetAddress, Ipv6Address, Ipv6Packet, Ipv6Repr};
+use crate::wire::{Ipv6Address, Ipv6Packet, Ipv6Repr, MAX_HARDWARE_ADDRESS_LEN};
 use crate::{Error, Result};
 
+use crate::wire::RawHardwareAddress;
+
 enum_with_unknown! {
     /// NDISC Option Type
     pub enum Type(u8) {
@@ -82,9 +84,6 @@ mod field {
     // |     Type      |    Length     |    Link-Layer Address ...
     // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 
-    // Link-Layer Address
-    pub const LL_ADDR: Field = 2..8;
-
     // Prefix Information Option fields.
     //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     //  |     Type      |    Length     | Prefix Length |L|A| Reserved1 |
@@ -214,9 +213,10 @@ impl<T: AsRef<[u8]>> NdiscOption<T> {
 impl<T: AsRef<[u8]>> NdiscOption<T> {
     /// Return the Source/Target Link-layer Address.
     #[inline]
-    pub fn link_layer_addr(&self) -> EthernetAddress {
+    pub fn link_layer_addr(&self) -> RawHardwareAddress {
+        let len = MAX_HARDWARE_ADDRESS_LEN.min(self.data_len() as usize * 8 - 2);
         let data = self.buffer.as_ref();
-        EthernetAddress::from_bytes(&data[field::LL_ADDR])
+        RawHardwareAddress::from_bytes(&data[2..len + 2])
     }
 }
 
@@ -297,9 +297,9 @@ impl<T: AsRef<[u8]> + AsMut<[u8]>> NdiscOption<T> {
 impl<T: AsRef<[u8]> + AsMut<[u8]>> NdiscOption<T> {
     /// Set the Source/Target Link-layer Address.
     #[inline]
-    pub fn set_link_layer_addr(&mut self, addr: EthernetAddress) {
+    pub fn set_link_layer_addr(&mut self, addr: RawHardwareAddress) {
         let data = self.buffer.as_mut();
-        data[field::LL_ADDR].copy_from_slice(addr.as_bytes())
+        data[2..2 + addr.len()].copy_from_slice(addr.as_bytes())
     }
 }
 
@@ -409,8 +409,8 @@ pub struct RedirectedHeader<'a> {
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Repr<'a> {
-    SourceLinkLayerAddr(EthernetAddress),
-    TargetLinkLayerAddr(EthernetAddress),
+    SourceLinkLayerAddr(RawHardwareAddress),
+    TargetLinkLayerAddr(RawHardwareAddress),
     PrefixInformation(PrefixInformation),
     RedirectedHeader(RedirectedHeader<'a>),
     Mtu(u32),
@@ -488,7 +488,11 @@ impl<'a> Repr<'a> {
     /// Return the length of a header that will be emitted from this high-level representation.
     pub fn buffer_len(&self) -> usize {
         match self {
-            &Repr::SourceLinkLayerAddr(_) | &Repr::TargetLinkLayerAddr(_) => field::LL_ADDR.end,
+            &Repr::SourceLinkLayerAddr(addr) | &Repr::TargetLinkLayerAddr(addr) => {
+                let len = 2 + addr.len();
+                // Round up to next multiple of 8
+                (len + 7) / 8 * 8
+            }
             &Repr::PrefixInformation(_) => field::PREFIX.end,
             &Repr::RedirectedHeader(RedirectedHeader { header, data }) => {
                 field::IP_DATA + header.buffer_len() + data.len()
@@ -506,12 +510,14 @@ impl<'a> Repr<'a> {
         match *self {
             Repr::SourceLinkLayerAddr(addr) => {
                 opt.set_option_type(Type::SourceLinkLayerAddr);
-                opt.set_data_len(1);
+                let opt_len = addr.len() + 2;
+                opt.set_data_len(((opt_len + 7) / 8) as u8); // round to next multiple of 8.
                 opt.set_link_layer_addr(addr);
             }
             Repr::TargetLinkLayerAddr(addr) => {
                 opt.set_option_type(Type::TargetLinkLayerAddr);
-                opt.set_data_len(1);
+                let opt_len = addr.len() + 2;
+                opt.set_data_len(((opt_len + 7) / 8) as u8); // round to next multiple of 8.
                 opt.set_link_layer_addr(addr);
             }
             Repr::PrefixInformation(PrefixInformation {
@@ -668,14 +674,14 @@ mod test {
         {
             assert_eq!(
                 Repr::parse(&NdiscOption::new_unchecked(&bytes)),
-                Ok(Repr::SourceLinkLayerAddr(addr))
+                Ok(Repr::SourceLinkLayerAddr(addr.into()))
             );
         }
         bytes[0] = 0x02;
         {
             assert_eq!(
                 Repr::parse(&NdiscOption::new_unchecked(&bytes)),
-                Ok(Repr::TargetLinkLayerAddr(addr))
+                Ok(Repr::TargetLinkLayerAddr(addr.into()))
             );
         }
     }

src/wire/sixlowpan.rs

@@ -0,0 +1,1738 @@
+/// Implementation of [RFC 6282] which specifies a compression format for IPv6 datagrams over
+/// IEEE802.154-based networks.
+///
+/// [RFC 6282]: https://datatracker.ietf.org/doc/html/rfc6282
+use crate::wire::ieee802154::Address as LlAddress;
+use crate::wire::ipv6;
+use crate::wire::IpProtocol;
+use crate::Error;
+use crate::Result;
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum NextHeader {
+    Compressed,
+    Uncompressed(IpProtocol),
+}
+
+/// A wrapper around the address provided in the 6LoWPAN_IPHC header.
+/// This requires some context to convert it the an IPv6 address in some cases.
+/// For 802.15.4 the context are the short/extended addresses.
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum Address<'a> {
+    Complete(ipv6::Address),
+    WithContext(&'a [u8]),
+    Elided,
+    Reserved,
+}
+
+impl<'a> Address<'a> {
+    /// Resolve the address provided by the IPHC encoding.
+    pub(crate) fn resolve(self, ll_addr: Option<LlAddress>) -> Result<ipv6::Address> {
+        match self {
+            Address::Complete(addr) => Ok(addr),
+            Address::Elided => {
+                let mut bytes = [0; 16];
+                bytes[0] = 0xfe;
+                bytes[1] = 0x80;
+
+                match ll_addr {
+                    Some(LlAddress::Short(ll)) => {
+                        bytes[11] = 0xff;
+                        bytes[12] = 0xfe;
+                        bytes[14..].copy_from_slice(&ll);
+                    }
+                    Some(LlAddress::Extended(ll)) => {
+                        bytes[8..].copy_from_slice(&LlAddress::Extended(ll).as_eui_64().unwrap());
+                    }
+                    _ => return Err(Error::Malformed),
+                }
+
+                Ok(ipv6::Address::from_bytes(&bytes))
+            }
+            Address::WithContext(_) => Err(Error::NotSupported),
+            Address::Reserved => Err(Error::Malformed),
+        }
+    }
+}
+
+pub mod iphc {
+    use crate::wire::ieee802154::Address as LlAddress;
+    use crate::wire::ipv6;
+    use crate::wire::IpProtocol;
+    use crate::Error;
+    use crate::Result;
+    use byteorder::{ByteOrder, NetworkEndian};
+
+    use super::Address;
+    use super::NextHeader;
+
+    mod field {
+        #![allow(non_snake_case)]
+
+        use crate::wire::field::*;
+
+        pub const IPHC_FIELD: Field = 0..2;
+    }
+
+    const DISPATCH: u8 = 0b011;
+
+    macro_rules! get_field {
+        ($name:ident, $mask:expr, $shift:expr) => {
+            fn $name(&self) -> u8 {
+                let data = self.buffer.as_ref();
+                let raw = NetworkEndian::read_u16(&data[field::IPHC_FIELD]);
+                ((raw >> $shift) & $mask) as u8
+            }
+        };
+    }
+
+    macro_rules! set_field {
+        ($name:ident, $mask:expr, $shift:expr) => {
+            fn $name(&mut self, val: u8) {
+                let data = &mut self.buffer.as_mut()[field::IPHC_FIELD];
+                let mut raw = NetworkEndian::read_u16(data);
+
+                raw = (raw & !($mask << $shift)) | ((val as u16) << $shift);
+                NetworkEndian::write_u16(data, raw);
+            }
+        };
+    }
+
+    /// A read/write wrapper around a LOWPAN_IPHC frame buffer.
+    #[derive(Debug, Clone)]
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+    pub struct Packet<T: AsRef<[u8]>> {
+        buffer: T,
+    }
+
+    impl<T: AsRef<[u8]>> Packet<T> {
+        /// Input a raw octet buffer with a 6LoWPAN_IPHC frame structure.
+        pub fn new_unchecked(buffer: T) -> Packet<T> {
+            Packet { buffer }
+        }
+
+        /// Shorthand for a combination of [new_unchecked] and [check_len].
+        ///
+        /// [new_unchecked]: #method.new_unchecked
+        /// [check_len]: #method.check_len
+        pub fn new_checked(buffer: T) -> Result<Packet<T>> {
+            let packet = Self::new_unchecked(buffer);
+            packet.check_len()?;
+            Ok(packet)
+        }
+
+        /// Ensure that no accessor method will panic if called.
+        /// Returns `Err(Error::Truncated)` if the buffer is too short.
+        pub fn check_len(&self) -> Result<()> {
+            let buffer = self.buffer.as_ref();
+            if buffer.len() < 2 {
+                Err(Error::Truncated)
+            } else {
+                Ok(())
+            }
+        }
+
+        /// Consumes the frame, returning the underlying buffer.
+        pub fn into_inner(self) -> T {
+            self.buffer
+        }
+
+        /// Return the Next Header field of this IPHC packet.
+        pub fn next_header(&self) -> NextHeader {
+            let nh = self.nh_field();
+
+            if nh == 1 {
+                // The next header field is compressed.
+                // It is also encoded using LOWPAN_NHC.
+                NextHeader::Compressed
+            } else {
+                // The full 8 bits for Next Header are carried in-line.
+                let start = (self.ip_fields_start() + self.traffic_class_size()) as usize;
+
+                let data = self.buffer.as_ref();
+                let nh = data[start..start + 1][0];
+                NextHeader::Uncompressed(IpProtocol::from(nh))
+            }
+        }
+
+        /// Return the Hop Limit of this IPHC packet.
+        pub fn hop_limit(&self) -> u8 {
+            match self.hlim_field() {
+                0b00 => {
+                    let start = (self.ip_fields_start()
+                        + self.traffic_class_size()
+                        + self.next_header_size()) as usize;
+
+                    let data = self.buffer.as_ref();
+                    data[start..start + 1][0]
+                }
+                0b01 => 1,
+                0b10 => 64,
+                0b11 => 255,
+                _ => unreachable!(),
+            }
+        }
+
+        /// Return the Source Context Identifier of this IPHC packet.
+        pub fn src_context_id(&self) -> Option<u8> {
+            if self.cid_field() == 1 {
+                let data = self.buffer.as_ref();
+                Some(data[1] >> 4)
+            } else {
+                None
+            }
+        }
+
+        /// Return the Destination Context Identifier of this IPHC packet.
+        pub fn dst_context_id(&self) -> Option<u8> {
+            if self.cid_field() == 1 {
+                let data = self.buffer.as_ref();
+                Some(data[1] & 0x0f)
+            } else {
+                None
+            }
+        }
+
+        /// Return the Source Address of this IPHC packet.
+        pub fn src_addr(&self) -> Result<Address> {
+            let start = (self.ip_fields_start()
+                + self.traffic_class_size()
+                + self.next_header_size()
+                + self.hop_limit_size()) as usize;
+
+            match (self.sac_field(), self.sam_field()) {
+                (0, 0b00) => {
+                    // The full address is carried in-line.
+                    let data = self.buffer.as_ref();
+                    Ok(Address::Complete(ipv6::Address::from_bytes(
+                        &data[start..start + 16],
+                    )))
+                }
+                (0, 0b01) => {
+                    // The first 64-bits of the address is elided.
+                    // The value of those bits is the link-local prefix padded with zeros.
+                    // The remaining 64-bits are carried in-line.
+                    let data = self.buffer.as_ref();
+                    let mut bytes = [0u8; 16];
+
+                    // Link-local prefix
+                    bytes[0] = 0xfe;
+                    bytes[1] = 0x80;
+
+                    bytes[8..].copy_from_slice(&data[start..start + 8]);
+
+                    Ok(Address::Complete(ipv6::Address::from_bytes(&bytes)))
+                }
+                (0, 0b10) => {
+                    // The first 112 bits of the address are elided.
+                    // The value of the 64 bits is the link-local prefix padded with zeros.
+                    // The following 64 bits are 0000:00ff:fe00:XXXX,
+                    // where XXXX are the bits carried in-line.
+                    let data = self.buffer.as_ref();
+                    let mut bytes = [0u8; 16];
+
+                    // Link-local prefix
+                    bytes[0] = 0xfe;
+                    bytes[1] = 0x80;
+
+                    bytes[11] = 0xff;
+                    bytes[12] = 0xfe;
+
+                    bytes[14..].copy_from_slice(&data[start..start + 2]);
+
+                    Ok(Address::Complete(ipv6::Address::from_bytes(&bytes)))
+                }
+                (0, 0b11) => {
+                    // The address is fully elided.
+                    // The first 64 bits of the address are the link-local prefix padded with zeros.
+                    // The remaining 64 bits are computed from the encapsulating header.
+                    Ok(Address::Elided)
+                }
+                (1, 0b00) => Ok(Address::Complete(ipv6::Address::UNSPECIFIED)),
+                (1, 0b01) => {
+                    // The address is derived using context information and the 64 bits carried in-line.
+                    // Bits covered by context information are always used.
+                    // Any IID bits not covered by context information are directly from the corresponding bits carried in-line.
+                    // Any remaining bits are zero.
+                    let data = self.buffer.as_ref();
+                    let bytes = &data[start..start + 8];
+
+                    Ok(Address::WithContext(bytes))
+                }
+                (1, 0b10) => {
+                    // The address is derived using context information and the 16 bits carried in-line.
+                    // Bits covered by context information are always used.
+                    // Any IID bits not covered by context information are directly from the corresponding bits carried in-line.
+                    // Any remaining bits are zero.
+                    let data = self.buffer.as_ref();
+                    let bytes = &data[start..start + 2];
+
+                    Ok(Address::WithContext(bytes))
+                }
+                (1, 0b11) => {
+                    // The address is fully elided and is derived using context information and the encapsulating header.
+                    // Bits covered by context information are always used.
+                    // Any IID bits not covered by context information are always used.
+                    // Any IID bits not covered by context information are directly from the corresponding bits carried in-line.
+                    // Any remaining bits are zero.
+                    Ok(Address::WithContext(&[]))
+                }
+                _ => Err(Error::Malformed),
+            }
+        }
+
+        /// Return the Destination Address of this IPHC packet.
+        pub fn dst_addr(&self) -> Result<Address> {
+            let start = (self.ip_fields_start()
+                + self.traffic_class_size()
+                + self.next_header_size()
+                + self.hop_limit_size()
+                + self.src_address_size()) as usize;
+
+            match (self.m_field(), self.dac_field(), self.dam_field()) {
+                (0, 0, 0b00) => {
+                    // The full address is carried in-line.
+                    let data = self.buffer.as_ref();
+                    Ok(Address::Complete(ipv6::Address::from_bytes(
+                        &data[start..start + 16],
+                    )))
+                }
+                (0, 0, 0b01) => {
+                    // The first 64-bits of the address is elided.
+                    // The value of those bits is the link-local prefix padded with zeros.
+                    // The remaining 64-bits are carried in-line.
+                    let data = self.buffer.as_ref();
+                    let mut bytes = [0u8; 16];
+
+                    // Link-local prefix
+                    bytes[0] = 0xfe;
+                    bytes[1] = 0x80;
+
+                    bytes[8..].copy_from_slice(&data[start..start + 8]);
+
+                    Ok(Address::Complete(ipv6::Address::from_bytes(&bytes)))
+                }
+                (0, 0, 0b10) => {
+                    // The first 112 bits of the address are elided.
+                    // The value of the 64 bits is the link-local prefix padded with zeros.
+                    // The following 64 bits are 0000:00ff:fe00:XXXX,
+                    // where XXXX are the bits carried in-line.
+                    let data = self.buffer.as_ref();
+                    let mut bytes = [0u8; 16];
+
+                    // Link-local prefix
+                    bytes[0] = 0xfe;
+                    bytes[1] = 0x80;
+
+                    bytes[11] = 0xff;
+                    bytes[12] = 0xfe;
+
+                    bytes[14..].copy_from_slice(&data[start..start + 2]);
+
+                    Ok(Address::Complete(ipv6::Address::from_bytes(&bytes)))
+                }
+                (0, 0, 0b11) => {
+                    // The address is fully elided.
+                    // The first 64 bits of the address are the link-local prefix padded with zeros.
+                    // The remaining 64 bits are computed from the encapsulating header.
+                    Ok(Address::Elided)
+                }
+                (0, 1, 0b00) => Ok(Address::Reserved),
+                (0, 1, 0b01) => {
+                    // The address is derived using context information and the 64 bits carried in-line.
+                    // Bits covered by context information are always used.
+                    // Any IID bits not covered by context information are directly from the corresponding bits carried in-line.
+                    // Any remaining bits are zero.
+                    let data = self.buffer.as_ref();
+                    let bytes = &data[start..start + 8];
+
+                    Ok(Address::WithContext(bytes))
+                }
+                (0, 1, 0b10) => {
+                    // The address is derived using context information and the 16 bits carried in-line.
+                    // Bits covered by context information are always used.
+                    // Any IID bits not covered by context information are directly from the corresponding bits carried in-line.
+                    // Any remaining bits are zero.
+                    let data = self.buffer.as_ref();
+                    let bytes = &data[start..start + 2];
+                    Ok(Address::WithContext(bytes))
+                }
+                (0, 1, 0b11) => {
+                    // The address is fully elided and is derived using context information and the encapsulating header.
+                    // Bits covered by context information are always used.
+                    // Any IID bits not covered by context information are always used.
+                    // Any IID bits not covered by context information are directly from the corresponding bits carried in-line.
+                    // Any remaining bits are zero.
+                    Ok(Address::WithContext(&[]))
+                }
+                (1, 0, 0b00) => {
+                    // The full address is carried in-line.
+                    let data = self.buffer.as_ref();
+                    Ok(Address::Complete(ipv6::Address::from_bytes(
+                        &data[start..start + 16],
+                    )))
+                }
+                (1, 0, 0b01) => {
+                    // The address takes the form ffXX::00XX:XXXX:XXXX
+                    let data = self.buffer.as_ref();
+                    let mut bytes = [0u8; 16];
+
+                    bytes[0] = 0xff;
+                    bytes[1] = data[start];
+
+                    bytes[11..].copy_from_slice(&data[start + 1..start + 6]);
+
+                    Ok(Address::Complete(ipv6::Address::from_bytes(&bytes)))
+                }
+                (1, 0, 0b10) => {
+                    // The address takes the form ffXX::00XX:XXXX
+                    let data = self.buffer.as_ref();
+                    let mut bytes = [0u8; 16];
+
+                    bytes[0] = 0xff;
+                    bytes[1] = data[start];
+
+                    bytes[13..].copy_from_slice(&data[start + 1..start + 4]);
+
+                    Ok(Address::Complete(ipv6::Address::from_bytes(&bytes)))
+                }
+                (1, 0, 0b11) => {
+                    // The address takes the form ff02::00XX
+                    let data = self.buffer.as_ref();
+                    let mut bytes = [0u8; 16];
+
+                    bytes[0] = 0xff;
+                    bytes[1] = 0x02;
+
+                    bytes[15] = data[start];
+
+                    Ok(Address::Complete(ipv6::Address::from_bytes(&bytes)))
+                }
+                (1, 1, 0b00) => {
+                    // This format is designed to match Unicast-Prefix-based IPv6 Multicast Addresses.
+                    // The multicast takes the form ffXX:XXLL:PPPP:PPPP:PPPP:PPPP:XXXX:XXXX.
+                    // X are octets that are carried in-line, in the order in which they appear.
+                    // P are octets used to encode the prefix itself.
+                    // L are octets used to encode the prefix length.
+                    // The prefix information P and L is taken from the specified context.
+                    Err(Error::NotSupported)
+                }
+                (1, 1, 0b01 | 0b10 | 0b11) => Ok(Address::Reserved),
+                _ => Err(Error::Malformed),
+            }
+        }
+
+        get_field!(dispatch_field, 0b111, 13);
+        get_field!(tf_field, 0b11, 11);
+        get_field!(nh_field, 0b1, 10);
+        get_field!(hlim_field, 0b11, 8);
+        get_field!(cid_field, 0b1, 7);
+        get_field!(sac_field, 0b1, 6);
+        get_field!(sam_field, 0b11, 4);
+        get_field!(m_field, 0b1, 3);
+        get_field!(dac_field, 0b1, 2);
+        get_field!(dam_field, 0b11, 0);
+
+        /// Return the start for the IP fields.
+        fn ip_fields_start(&self) -> u8 {
+            2 + self.cid_size()
+        }
+
+        /// Get the size in octets of the traffic class field.
+        fn traffic_class_size(&self) -> u8 {
+            match self.tf_field() {
+                0b00 => 4,
+                0b01 => 3,
+                0b10 => 1,
+                0b11 => 0,
+                _ => unreachable!(),
+            }
+        }
+
+        /// Get the size in octets of the next header field.
+        fn next_header_size(&self) -> u8 {
+            (self.nh_field() != 1) as u8
+        }
+
+        /// Get the size in octets of the hop limit field.
+        fn hop_limit_size(&self) -> u8 {
+            (self.hlim_field() == 0b00) as u8
+        }
+
+        /// Get the size in octets of the CID field.
+        fn cid_size(&self) -> u8 {
+            (self.cid_field() == 1) as u8
+        }
+
+        /// Get the size in octets of the source address.
+        fn src_address_size(&self) -> u8 {
+            match (self.sac_field(), self.sam_field()) {
+                (0, 0b00) => 16, // The full address is carried in-line.
+                (0, 0b01) => 8,  // The first 64 bits are elided.
+                (0, 0b10) => 2,  // The first 112 bits are elided.
+                (0, 0b11) => 0,  // The address is fully elided.
+                (1, 0b00) => 0,  // The UNSPECIFIED address.
+                (1, 0b01) => 8,  // Address derived using context information.
+                (1, 0b10) => 2,  // Address derived using context information.
+                (1, 0b11) => 0,  // Address derived using context information.
+                _ => unreachable!(),
+            }
+        }
+
+        /// Get the size in octets of the address address.
+        fn dst_address_size(&self) -> u8 {
+            match (self.m_field(), self.dac_field(), self.dam_field()) {
+                (0, 0, 0b00) => 16, // The full address is carried in-line.
+                (0, 0, 0b01) => 8,  // The first 64 bits are elided.
+                (0, 0, 0b10) => 2,  // The first 112 bits are elided.
+                (0, 0, 0b11) => 0,  // The address is fully elided.
+                (0, 1, 0b00) => 0,  // Reserved.
+                (0, 1, 0b01) => 8,  // Address derived using context information.
+                (0, 1, 0b10) => 2,  // Address derived using context information.
+                (0, 1, 0b11) => 0,  // Address derived using context information.
+                (1, 0, 0b00) => 16, // The full address is carried in-line.
+                (1, 0, 0b01) => 6,  // The address takes the form ffXX::00XX:XXXX:XXXX.
+                (1, 0, 0b10) => 4,  // The address takes the form ffXX::00XX:XXXX.
+                (1, 0, 0b11) => 1,  // The address takes the form ff02::00XX.
+                (1, 1, 0b00) => 6,  // Match Unicast-Prefix-based IPv6.
+                (1, 1, 0b01) => 0,  // Reserved.
+                (1, 1, 0b10) => 0,  // Reserved.
+                (1, 1, 0b11) => 0,  // Reserved.
+                _ => unreachable!(),
+            }
+        }
+    }
+
+    impl<'a, T: AsRef<[u8]> + ?Sized> Packet<&'a T> {
+        /// Return a pointer to the payload.
+        pub fn payload(&self) -> &'a [u8] {
+            let mut len = self.ip_fields_start();
+            len += self.traffic_class_size();
+            len += self.next_header_size();
+            len += self.hop_limit_size();
+            len += self.src_address_size();
+            len += self.dst_address_size();
+
+            let len = len as usize;
+
+            let data = self.buffer.as_ref();
+            &data[len..]
+        }
+    }
+
+    impl<'a, T: AsRef<[u8]> + AsMut<[u8]>> Packet<T> {
+        /// Set the dispatch field to `0b011`.
+        fn set_dispatch_field(&mut self) {
+            let data = &mut self.buffer.as_mut()[field::IPHC_FIELD];
+            let mut raw = NetworkEndian::read_u16(data);
+
+            raw = (raw & !(0b111 << 13)) | (0b11 << 13);
+            NetworkEndian::write_u16(data, raw);
+        }
+
+        set_field!(set_tf_field, 0b11, 11);
+        set_field!(set_nh_field, 0b1, 10);
+        set_field!(set_hlim_field, 0b11, 8);
+        set_field!(set_cid_field, 0b1, 7);
+        set_field!(set_sac_field, 0b1, 6);
+        set_field!(set_sam_field, 0b11, 4);
+        set_field!(set_m_field, 0b1, 3);
+        set_field!(set_dac_field, 0b1, 2);
+        set_field!(set_dam_field, 0b11, 0);
+
+        fn set_field(&mut self, idx: usize, value: &[u8]) {
+            let raw = self.buffer.as_mut();
+            raw[idx..idx + value.len()].copy_from_slice(value);
+        }
+
+        /// Set the Next Header of this IPHC packet.
+        ///
+        /// **NOTE**: `idx` is the offset at which the Next Header needs to be written to.
+        fn set_next_header(&mut self, nh: NextHeader, mut idx: usize) -> usize {
+            match nh {
+                NextHeader::Uncompressed(nh) => {
+                    self.set_nh_field(0);
+                    self.set_field(idx, &[nh.into()]);
+                    idx += 1;
+                }
+                NextHeader::Compressed => self.set_nh_field(1),
+            }
+
+            idx
+        }
+
+        /// Set the Hop Limit of this IPHC packet.
+        ///
+        /// **NOTE**: `idx` is the offset at which the Next Header needs to be written to.
+        fn set_hop_limit(&mut self, hl: u8, mut idx: usize) -> usize {
+            match hl {
+                255 => self.set_hlim_field(0b11),
+                64 => self.set_hlim_field(0b10),
+                1 => self.set_hlim_field(0b01),
+                _ => {
+                    self.set_hlim_field(0b00);
+                    self.set_field(idx, &[hl]);
+                    idx += 1;
+                }
+            }
+
+            idx
+        }
+
+        /// Set the Source Address based on the IPv6 address and the Link-Local address.
+        ///
+        /// **NOTE**: `idx` is the offset at which the Next Header needs to be written to.
+        fn set_src_address(
+            &mut self,
+            src_addr: ipv6::Address,
+            ll_src_addr: Option<LlAddress>,
+            mut idx: usize,
+        ) -> usize {
+            self.set_cid_field(0);
+            self.set_sac_field(0);
+            self.set_sam_field(0b11);
+            let src = src_addr.as_bytes();
+            if src_addr == ipv6::Address::UNSPECIFIED {
+                self.set_sac_field(1);
+                self.set_sam_field(0b00);
+            } else if src_addr.is_link_local() {
+                // We have a link local address.
+                // The remainder of the address can be elided when the context contains
+                // a 802.15.4 short address or a 802.15.4 extended address which can be
+                // converted to a eui64 address.
+                let is_eui_64 = ll_src_addr
+                    .map(|addr| {
+                        addr.as_eui_64()
+                            .map(|addr| addr[..] == src[8..])
+                            .unwrap_or(false)
+                    })
+                    .unwrap_or(false);
+
+                if src[8..14] == [0, 0, 0, 0xff, 0xfe, 0] {
+                    let ll = [src[14], src[15]];
+
+                    if ll_src_addr == Some(LlAddress::Short(ll)) {
+                        // We have the context from the 802.15.4 frame.
+                        // The context contains the short address.
+                        // We can elide the source address.
+                        self.set_sam_field(0b11);
+                    } else {
+                        // We don't have the context from the 802.15.4 frame.
+                        // We cannot elide the source address, however we can elide 112 bits.
+                        self.set_sam_field(0b10);
+
+                        self.set_field(idx, &src[14..]);
+                        idx += 2;
+                    }
+                } else if is_eui_64 {
+                    // We have the context from the 802.15.4 frame.
+                    // The context contains the extended address.
+                    // We can elide the source address.
+                    self.set_sam_field(0b11);
+                } else {
+                    // We cannot elide the source address, however we can elide 64 bits.
+                    self.set_sam_field(0b01);
+
+                    self.set_field(idx, &src[8..]);
+                    idx += 8;
+                }
+            } else {
+                // We cannot elide anything.
+                self.set_field(idx, src);
+                idx += 16;
+            }
+
+            idx
+        }
+
+        /// Set the Destination Address based on the IPv6 address and the Link-Local address.
+        ///
+        /// **NOTE**: `idx` is the offset at which the Next Header needs to be written to.
+        fn set_dst_address(
+            &mut self,
+            dst_addr: ipv6::Address,
+            ll_dst_addr: Option<LlAddress>,
+            mut idx: usize,
+        ) -> usize {
+            self.set_dac_field(0);
+            self.set_dam_field(0);
+            self.set_m_field(0);
+            let dst = dst_addr.as_bytes();
+            if dst_addr.is_multicast() {
+                self.set_m_field(1);
+
+                if dst[1] == 0x02 && dst[2..15] == [0; 13] {
+                    self.set_dam_field(0b11);
+
+                    self.set_field(idx, &[dst[15]]);
+                    idx += 1;
+                } else if dst[2..13] == [0; 11] {
+                    self.set_dam_field(0b10);
+
+                    self.set_field(idx, &[dst[1]]);
+                    idx += 1;
+                    self.set_field(idx, &dst[13..]);
+                    idx += 3;
+                } else if dst[2..11] == [0; 9] {
+                    self.set_dam_field(0b01);
+
+                    self.set_field(idx, &[dst[1]]);
+                    idx += 1;
+                    self.set_field(idx, &dst[11..]);
+                    idx += 5;
+                } else {
+                    self.set_dam_field(0b11);
+
+                    self.set_field(idx, dst);
+                    idx += 16;
+                }
+            } else if dst_addr.is_link_local() {
+                let is_eui_64 = ll_dst_addr
+                    .map(|addr| {
+                        addr.as_eui_64()
+                            .map(|addr| addr[..] == dst[8..])
+                            .unwrap_or(false)
+                    })
+                    .unwrap_or(false);
+
+                if dst[8..14] == [0, 0, 0, 0xff, 0xfe, 0] {
+                    let ll = [dst[14], dst[15]];
+
+                    if ll_dst_addr == Some(LlAddress::Short(ll)) {
+                        self.set_dam_field(0b11);
+                    } else {
+                        self.set_dam_field(0b10);
+
+                        self.set_field(idx, &dst[14..]);
+                        idx += 2;
+                    }
+                } else if is_eui_64 {
+                    self.set_dam_field(0b11);
+                } else {
+                    self.set_dam_field(0b01);
+
+                    self.set_field(idx, &dst[8..]);
+                    idx += 8;
+                }
+            } else {
+                self.set_dam_field(0b00);
+
+                self.set_field(idx, dst);
+                idx += 16;
+            }
+
+            idx
+        }
+
+        /// Return a mutable pointer to the payload.
+        pub fn payload_mut(&mut self) -> &mut [u8] {
+            let mut len = self.ip_fields_start();
+
+            len += self.traffic_class_size();
+            len += self.next_header_size();
+            len += self.hop_limit_size();
+            len += self.src_address_size();
+            len += self.dst_address_size();
+
+            let len = len as usize;
+
+            let data = self.buffer.as_mut();
+            &mut data[len..]
+        }
+    }
+
+    /// A high-level representation of a LOWPAN_IPHC header.
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+    pub struct Repr {
+        pub src_addr: ipv6::Address,
+        pub ll_src_addr: Option<LlAddress>,
+        pub dst_addr: ipv6::Address,
+        pub ll_dst_addr: Option<LlAddress>,
+        pub next_header: NextHeader,
+        pub hop_limit: u8,
+    }
+
+    impl Repr {
+        /// Parse a LOWPAN_IPHC packet and return a high-level representation.
+        ///
+        /// The `ll_src_addr` and `ll_dst_addr` are the link-local addresses used for resolving the
+        /// IPv6 packets.
+        pub fn parse<T: AsRef<[u8]> + ?Sized>(
+            packet: &Packet<&T>,
+            ll_src_addr: Option<LlAddress>,
+            ll_dst_addr: Option<LlAddress>,
+        ) -> Result<Repr> {
+            // Ensure basic accessors will work.
+            packet.check_len()?;
+
+            if packet.dispatch_field() != DISPATCH {
+                // This is not an LOWPAN_IPHC packet.
+                return Err(Error::Malformed);
+            }
+
+            let src_addr = packet.src_addr()?.resolve(ll_src_addr)?;
+            let dst_addr = packet.dst_addr()?.resolve(ll_dst_addr)?;
+
+            Ok(Repr {
+                src_addr,
+                ll_src_addr,
+                dst_addr,
+                ll_dst_addr,
+                next_header: packet.next_header(),
+                hop_limit: packet.hop_limit(),
+            })
+        }
+
+        /// Return the length of a header that will be emitted from this high-level representation.
+        pub fn buffer_len(&self) -> usize {
+            let mut len = 0;
+            len += 2; // The minimal header length
+
+            len += if self.next_header == NextHeader::Compressed {
+                0 // The next header is compressed (we don't need to inline what the next header is)
+            } else {
+                1 // The next header field is inlined
+            };
+
+            // Add the lenght of the source address
+            len += if self.src_addr == ipv6::Address::UNSPECIFIED {
+                0
+            } else if self.src_addr.is_link_local() {
+                let src = self.src_addr.as_bytes();
+                let ll = [src[14], src[15]];
+
+                let is_eui_64 = self
+                    .ll_src_addr
+                    .map(|addr| {
+                        addr.as_eui_64()
+                            .map(|addr| addr[..] == src[8..])
+                            .unwrap_or(false)
+                    })
+                    .unwrap_or(false);
+
+                if src[8..14] == [0, 0, 0, 0xff, 0xfe, 0] {
+                    if self.ll_src_addr == Some(LlAddress::Short(ll)) {
+                        0
+                    } else {
+                        2
+                    }
+                } else if is_eui_64 {
+                    0
+                } else {
+                    8
+                }
+            } else {
+                16
+            };
+
+            // Add the size of the destination header
+            let dst = self.dst_addr.as_bytes();
+            len += if self.dst_addr.is_multicast() {
+                if dst[1] == 0x02 && dst[2..15] == [0; 13] {
+                    1
+                } else if dst[2..13] == [0; 11] {
+                    4
+                } else if dst[2..11] == [0; 9] {
+                    6
+                } else {
+                    16
+                }
+            } else if self.dst_addr.is_link_local() {
+                let is_eui_64 = self
+                    .ll_dst_addr
+                    .map(|addr| {
+                        addr.as_eui_64()
+                            .map(|addr| addr[..] == dst[8..])
+                            .unwrap_or(false)
+                    })
+                    .unwrap_or(false);
+
+                if dst[8..14] == [0, 0, 0, 0xff, 0xfe, 0] {
+                    let ll = [dst[14], dst[15]];
+
+                    if self.ll_dst_addr == Some(LlAddress::Short(ll)) {
+                        0
+                    } else {
+                        2
+                    }
+                } else if is_eui_64 {
+                    0
+                } else {
+                    8
+                }
+            } else {
+                16
+            };
+
+            // Add the size of the traffic flow.
+            // TODO(thvdveld): implement traffic flow for sixlowpan
+            len += 0;
+
+            len
+        }
+
+        /// Emit a high-level representation into a LOWPAN_IPHC packet.
+        pub fn emit<T: AsRef<[u8]> + AsMut<[u8]>>(&self, packet: &mut Packet<T>) {
+            let idx = 2;
+
+            packet.set_dispatch_field();
+
+            // SETTING THE TRAFIC FLOW
+            // TODO(thvdveld): needs more work.
+            packet.set_tf_field(0b11);
+
+            let idx = packet.set_next_header(self.next_header, idx);
+            let idx = packet.set_hop_limit(self.hop_limit, idx);
+            let idx = packet.set_src_address(self.src_addr, self.ll_src_addr, idx);
+            packet.set_dst_address(self.dst_addr, self.ll_dst_addr, idx);
+        }
+    }
+
+    #[cfg(test)]
+    mod test {
+        use super::*;
+
+        #[test]
+        fn iphc_fields() {
+            let bytes = [
+                0x7a, 0x33, // IPHC
+                0x3a, // Next header
+            ];
+
+            let packet = Packet::new_unchecked(bytes);
+
+            assert_eq!(packet.dispatch_field(), 0b011);
+            assert_eq!(packet.tf_field(), 0b11);
+            assert_eq!(packet.nh_field(), 0b0);
+            assert_eq!(packet.hlim_field(), 0b10);
+            assert_eq!(packet.cid_field(), 0b0);
+            assert_eq!(packet.sac_field(), 0b0);
+            assert_eq!(packet.sam_field(), 0b11);
+            assert_eq!(packet.m_field(), 0b0);
+            assert_eq!(packet.dac_field(), 0b0);
+            assert_eq!(packet.dam_field(), 0b11);
+
+            assert_eq!(
+                packet.next_header(),
+                NextHeader::Uncompressed(IpProtocol::Icmpv6)
+            );
+
+            assert_eq!(packet.src_address_size(), 0);
+            assert_eq!(packet.dst_address_size(), 0);
+            assert_eq!(packet.hop_limit(), 64);
+
+            assert_eq!(packet.src_addr(), Ok(Address::Elided));
+            assert_eq!(packet.dst_addr(), Ok(Address::Elided));
+
+            let bytes = [
+                0x7e, 0xf7, // IPHC,
+                0x00, // CID
+            ];
+
+            let packet = Packet::new_unchecked(bytes);
+
+            assert_eq!(packet.dispatch_field(), 0b011);
+            assert_eq!(packet.tf_field(), 0b11);
+            assert_eq!(packet.nh_field(), 0b1);
+            assert_eq!(packet.hlim_field(), 0b10);
+            assert_eq!(packet.cid_field(), 0b1);
+            assert_eq!(packet.sac_field(), 0b1);
+            assert_eq!(packet.sam_field(), 0b11);
+            assert_eq!(packet.m_field(), 0b0);
+            assert_eq!(packet.dac_field(), 0b1);
+            assert_eq!(packet.dam_field(), 0b11);
+
+            assert_eq!(packet.next_header(), NextHeader::Compressed);
+
+            assert_eq!(packet.src_address_size(), 0);
+            assert_eq!(packet.dst_address_size(), 0);
+            assert_eq!(packet.hop_limit(), 64);
+
+            assert_eq!(packet.src_addr(), Ok(Address::WithContext(&[])));
+            assert_eq!(packet.dst_addr(), Ok(Address::WithContext(&[])));
+        }
+    }
+}
+
+pub mod nhc {
+    use crate::wire::ip::checksum;
+    use crate::wire::ip::Address as IpAddress;
+    use crate::wire::ipv6;
+    use crate::wire::udp::Repr as UdpRepr;
+    use crate::wire::IpProtocol;
+    use crate::Error;
+    use crate::Result;
+    use byteorder::{ByteOrder, NetworkEndian};
+    use ipv6::Address;
+
+    use super::NextHeader;
+
+    macro_rules! get_field {
+        ($name:ident, $mask:expr, $shift:expr) => {
+            fn $name(&self) -> u8 {
+                let data = self.buffer.as_ref();
+                let raw = &data[0];
+                ((raw >> $shift) & $mask) as u8
+            }
+        };
+    }
+
+    macro_rules! set_field {
+        ($name:ident, $mask:expr, $shift:expr) => {
+            fn $name(&mut self, val: u8) {
+                let data = self.buffer.as_mut();
+                let mut raw = data[0];
+                raw = (raw & !($mask << $shift)) | (val << $shift);
+                data[0] = raw;
+            }
+        };
+    }
+
+    /// A read/write wrapper around a LOWPAN_NHC frame buffer.
+    #[derive(Debug, Clone)]
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+    pub enum Packet<T: AsRef<[u8]>> {
+        ExtensionHeader(ExtensionHeaderPacket<T>),
+        UdpHeader(UdpPacket<T>),
+    }
+
+    impl<T: AsRef<[u8]>> Packet<T> {
+        pub fn dispatch(buffer: T) -> Result<Packet<T>> {
+            let raw = buffer.as_ref();
+
+            #[cfg(feature = "std")]
+            println!("{:02x?}", raw[0]);
+
+            if raw[0] >> 4 == 0b1110 {
+                // We have a compressed IPv6 Extension Header.
+                Ok(Packet::ExtensionHeader(ExtensionHeaderPacket::new_checked(
+                    buffer,
+                )?))
+            } else if raw[0] >> 3 == 0b11110 {
+                // We have a compressed UDP header.
+                Ok(Packet::UdpHeader(UdpPacket::new_checked(buffer)?))
+            } else {
+                Err(Error::Unrecognized)
+            }
+        }
+    }
+
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+    pub enum ExtensionHeaderId {
+        HopByHopHeader,
+        RoutingHeader,
+        FragmentHeader,
+        DestinationOptionsHeader,
+        MobilityHeader,
+        Header,
+        Reserved,
+    }
+
+    impl From<ExtensionHeaderId> for IpProtocol {
+        fn from(val: ExtensionHeaderId) -> Self {
+            match val {
+                ExtensionHeaderId::HopByHopHeader => IpProtocol::HopByHop,
+                ExtensionHeaderId::RoutingHeader => IpProtocol::Ipv6Route,
+                ExtensionHeaderId::FragmentHeader => IpProtocol::Ipv6Frag,
+                ExtensionHeaderId::DestinationOptionsHeader => IpProtocol::Ipv6Opts,
+                ExtensionHeaderId::MobilityHeader => IpProtocol::Unknown(0),
+                ExtensionHeaderId::Header => IpProtocol::Unknown(0),
+                ExtensionHeaderId::Reserved => IpProtocol::Unknown(0),
+            }
+        }
+    }
+
+    pub(crate) const EXT_HEADER_DISPATCH: u8 = 0b1110;
+
+    /// A read/write wrapper around a LOWPAN_NHC Next Header frame buffer.
+    #[derive(Debug, Clone)]
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+    pub struct ExtensionHeaderPacket<T: AsRef<[u8]>> {
+        buffer: T,
+    }
+
+    impl<T: AsRef<[u8]>> ExtensionHeaderPacket<T> {
+        /// Input a raw octet buffer with a LOWPAN_NHC Extension Header frame structure.
+        pub fn new_unchecked(buffer: T) -> ExtensionHeaderPacket<T> {
+            ExtensionHeaderPacket { buffer }
+        }
+
+        /// Shorthand for a combination of [new_unchecked] and [check_len].
+        ///
+        /// [new_unchecked]: #method.new_unchecked
+        /// [check_len]: #method.check_len
+        pub fn new_checked(buffer: T) -> Result<ExtensionHeaderPacket<T>> {
+            let packet = Self::new_unchecked(buffer);
+            packet.check_len()?;
+            Ok(packet)
+        }
+
+        /// Ensure that no accessor method will panic if called.
+        /// Returns `Err(Error::Truncated)` if the buffer is too short.
+        pub fn check_len(&self) -> Result<()> {
+            let buffer = self.buffer.as_ref();
+            if buffer.is_empty() {
+                Err(Error::Truncated)
+            } else {
+                Ok(())
+            }
+        }
+
+        /// Consumes the frame, returning the underlying buffer.
+        pub fn into_inner(self) -> T {
+            self.buffer
+        }
+
+        get_field!(dispatch_field, 0b1111, 4);
+        get_field!(eid_field, 0b111, 1);
+        get_field!(nh_field, 0b1, 0);
+
+        /// Return the Extension Header ID.
+        pub fn extension_header_id(&self) -> ExtensionHeaderId {
+            match self.eid_field() {
+                0 => ExtensionHeaderId::HopByHopHeader,
+                1 => ExtensionHeaderId::RoutingHeader,
+                2 => ExtensionHeaderId::FragmentHeader,
+                3 => ExtensionHeaderId::DestinationOptionsHeader,
+                4 => ExtensionHeaderId::MobilityHeader,
+                5 | 6 => ExtensionHeaderId::Reserved,
+                7 => ExtensionHeaderId::Header,
+                _ => unreachable!(),
+            }
+        }
+
+        /// Return the length field.
+        pub fn length_field(&self) -> u8 {
+            let start = 1 + self.next_header_size();
+
+            let data = self.buffer.as_ref();
+            data[start]
+        }
+
+        /// Parse the next header field.
+        pub fn next_header(&self) -> NextHeader {
+            if self.nh_field() == 1 {
+                NextHeader::Compressed
+            } else {
+                // The full 8 bits for Next Header are carried in-line.
+                let start = 1;
+
+                let data = self.buffer.as_ref();
+                let nh = data[start];
+                NextHeader::Uncompressed(IpProtocol::from(nh))
+            }
+        }
+
+        /// Return the size of the Next Header field.
+        fn next_header_size(&self) -> usize {
+            // If nh is set, then the Next Header is compressed using LOWPAN_NHC
+            if self.nh_field() == 1 {
+                0
+            } else {
+                1
+            }
+        }
+    }
+
+    impl<'a, T: AsRef<[u8]> + ?Sized> ExtensionHeaderPacket<&'a T> {
+        /// Return a pointer to the payload.
+        pub fn payload(&self) -> &'a [u8] {
+            let start = 2 + self.next_header_size();
+            &self.buffer.as_ref()[start..]
+        }
+    }
+
+    impl<'a, T: AsRef<[u8]> + AsMut<[u8]>> ExtensionHeaderPacket<T> {
+        /// Return a mutable pointer to the payload.
+        pub fn payload_mut(&mut self) -> &mut [u8] {
+            let start = 2 + self.next_header_size();
+            &mut self.buffer.as_mut()[start..]
+        }
+
+        /// Set the dispatch field to `0b1110`.
+        fn set_dispatch_field(&mut self) {
+            let data = self.buffer.as_mut();
+            data[0] = (data[0] & !(0b1111 << 4)) | (EXT_HEADER_DISPATCH << 4);
+        }
+
+        set_field!(set_eid_field, 0b111, 1);
+        set_field!(set_nh_field, 0b1, 0);
+
+        /// Set the Extension Header ID field.
+        fn set_extension_header_id(&mut self, ext_header_id: ExtensionHeaderId) {
+            let id = match ext_header_id {
+                ExtensionHeaderId::HopByHopHeader => 0,
+                ExtensionHeaderId::RoutingHeader => 1,
+                ExtensionHeaderId::FragmentHeader => 2,
+                ExtensionHeaderId::DestinationOptionsHeader => 3,
+                ExtensionHeaderId::MobilityHeader => 4,
+                ExtensionHeaderId::Header => 7,
+                _ => unreachable!(),
+            };
+
+            self.set_eid_field(id);
+        }
+
+        /// Set the Next Header.
+        fn set_next_header(&mut self, next_header: NextHeader) {
+            match next_header {
+                NextHeader::Compressed => self.set_nh_field(0b1),
+                NextHeader::Uncompressed(nh) => {
+                    self.set_nh_field(0b0);
+
+                    let start = 1;
+                    let data = self.buffer.as_mut();
+                    data[start] = nh.into();
+                }
+            }
+        }
+
+        /// Set the length.
+        fn set_length(&mut self, length: u8) {
+            let start = 1 + self.next_header_size();
+
+            let data = self.buffer.as_mut();
+            data[start] = length;
+        }
+    }
+
+    /// A high-level representation of an LOWPAN_NHC Extension Header header.
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+    pub struct ExtensionHeaderRepr {
+        ext_header_id: ExtensionHeaderId,
+        next_header: NextHeader,
+        length: u8,
+    }
+
+    impl ExtensionHeaderRepr {
+        /// Parse a LOWPAN_NHC Extension Header packet and return a high-level representation.
+        pub fn parse<T: AsRef<[u8]> + ?Sized>(
+            packet: &ExtensionHeaderPacket<&T>,
+        ) -> Result<ExtensionHeaderRepr> {
+            // Ensure basic accessors will work.
+            packet.check_len()?;
+
+            if packet.dispatch_field() != EXT_HEADER_DISPATCH {
+                return Err(Error::Malformed);
+            }
+
+            Ok(ExtensionHeaderRepr {
+                ext_header_id: packet.extension_header_id(),
+                next_header: packet.next_header(),
+                length: packet.payload().len() as u8,
+            })
+        }
+
+        /// Return the length of a header that will be emitted from this high-level representation.
+        pub fn buffer_len(&self) -> usize {
+            let mut len = 1; // The minimal header size
+
+            if self.next_header != NextHeader::Compressed {
+                len += 1;
+            }
+
+            len += 1; // The length
+
+            len
+        }
+
+        /// Emit a high-level representaiton into a LOWPAN_NHC Extension Header packet.
+        pub fn emit<T: AsRef<[u8]> + AsMut<[u8]>>(&self, packet: &mut ExtensionHeaderPacket<T>) {
+            packet.set_dispatch_field();
+            packet.set_extension_header_id(self.ext_header_id);
+            packet.set_next_header(self.next_header);
+            packet.set_length(self.length);
+        }
+    }
+
+    pub(crate) const UDP_DISPATCH: u8 = 0b11110;
+
+    /// A read/write wrapper around a 6LoWPAN_NHC_UDP frame buffer.
+    #[derive(Debug, Clone)]
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+    pub struct UdpPacket<T: AsRef<[u8]>> {
+        buffer: T,
+    }
+
+    impl<T: AsRef<[u8]>> UdpPacket<T> {
+        /// Input a raw octet buffer with a LOWPAN_NHC frame structure for UDP.
+        pub fn new_unchecked(buffer: T) -> UdpPacket<T> {
+            UdpPacket { buffer }
+        }
+
+        /// Shorthand for a combination of [new_unchecked] and [check_len].
+        ///
+        /// [new_unchecked]: #method.new_unchecked
+        /// [check_len]: #method.check_len
+        pub fn new_checked(buffer: T) -> Result<UdpPacket<T>> {
+            let packet = Self::new_unchecked(buffer);
+            packet.check_len()?;
+            Ok(packet)
+        }
+
+        /// Ensure that no accessor method will panic if called.
+        /// Returns `Err(Error::Truncated)` if the buffer is too short.
+        pub fn check_len(&self) -> Result<()> {
+            let buffer = self.buffer.as_ref();
+            if buffer.is_empty() {
+                Err(Error::Truncated)
+            } else {
+                Ok(())
+            }
+        }
+
+        /// Consumes the frame, returning the underlying buffer.
+        pub fn into_inner(self) -> T {
+            self.buffer
+        }
+
+        get_field!(dispatch_field, 0b11111, 3);
+        get_field!(checksum_field, 0b1, 2);
+        get_field!(ports_field, 0b11, 0);
+
+        /// Returns the index of the start of the next header compressed fields.
+        fn nhc_fields_start(&self) -> usize {
+            1
+        }
+
+        /// Return the source port number.
+        pub fn src_port(&self) -> u16 {
+            match self.ports_field() {
+                0b00 | 0b01 => {
+                    // The full 16 bits are carried in-line.
+                    let data = self.buffer.as_ref();
+                    let start = self.nhc_fields_start();
+
+                    NetworkEndian::read_u16(&data[start..start + 2])
+                }
+                0b10 => {
+                    // The first 8 bits are elided.
+                    let data = self.buffer.as_ref();
+                    let start = self.nhc_fields_start();
+
+                    0xf000 + data[start] as u16
+                }
+                0b11 => {
+                    // The first 12 bits are elided.
+                    let data = self.buffer.as_ref();
+                    let start = self.nhc_fields_start();
+
+                    0xf0b0 + (data[start] >> 4) as u16
+                }
+                _ => unreachable!(),
+            }
+        }
+
+        /// Return the destination port number.
+        pub fn dst_port(&self) -> u16 {
+            match self.ports_field() {
+                0b00 => {
+                    // The full 16 bits are carried in-line.
+                    let data = self.buffer.as_ref();
+                    let idx = self.nhc_fields_start();
+
+                    NetworkEndian::read_u16(&data[idx + 2..idx + 4])
+                }
+                0b01 => {
+                    // The first 8 bits are elided.
+                    let data = self.buffer.as_ref();
+                    let idx = self.nhc_fields_start();
+
+                    0xf000 + data[idx] as u16
+                }
+                0b10 => {
+                    // The full 16 bits are carried in-line.
+                    let data = self.buffer.as_ref();
+                    let idx = self.nhc_fields_start();
+
+                    NetworkEndian::read_u16(&data[idx + 1..idx + 1 + 2])
+                }
+                0b11 => {
+                    // The first 12 bits are elided.
+                    let data = self.buffer.as_ref();
+                    let start = self.nhc_fields_start();
+
+                    0xf0b0 + (NetworkEndian::read_u16(&data[start..start + 1]) & 0xff)
+                }
+                _ => unreachable!(),
+            }
+        }
+
+        /// Return the checksum.
+        pub fn checksum(&self) -> Option<u16> {
+            if self.checksum_field() == 0b0 {
+                // The first 12 bits are elided.
+                let data = self.buffer.as_ref();
+                let start = self.nhc_fields_start() + self.ports_size();
+                Some(NetworkEndian::read_u16(&data[start..start + 2]))
+            } else {
+                // The checksum is ellided and needs to be recomputed on the 6LoWPAN termination point.
+                None
+            }
+        }
+
+        // Return the size of the checksum field.
+        fn checksum_size(&self) -> usize {
+            match self.checksum_field() {
+                0b0 => 2,
+                0b1 => 0,
+                _ => unreachable!(),
+            }
+        }
+
+        /// Returns the total size of both port numbers.
+        fn ports_size(&self) -> usize {
+            match self.ports_field() {
+                0b00 => 4, // 16 bits + 16 bits
+                0b01 => 3, // 16 bits + 8 bits
+                0b10 => 3, // 8 bits + 16 bits
+                0b11 => 1, // 4 bits + 4 bits
+                _ => unreachable!(),
+            }
+        }
+    }
+
+    impl<'a, T: AsRef<[u8]> + ?Sized> UdpPacket<&'a T> {
+        /// Return a pointer to the payload.
+        pub fn payload(&self) -> &'a [u8] {
+            let start = 1 + self.ports_size() + self.checksum_size();
+            &self.buffer.as_ref()[start..]
+        }
+    }
+
+    impl<'a, T: AsRef<[u8]> + AsMut<[u8]>> UdpPacket<T> {
+        /// Return a mutable pointer to the payload.
+        pub fn payload_mut(&mut self) -> &mut [u8] {
+            let start = 1 + self.ports_size() + 2; // XXX(thvdveld): we assume we put the checksum inlined.
+            &mut self.buffer.as_mut()[start..]
+        }
+
+        /// Set the dispatch field to `0b11110`.
+        fn set_dispatch_field(&mut self) {
+            let data = self.buffer.as_mut();
+            data[0] = (data[0] & !(0b11111 << 3)) | (UDP_DISPATCH << 3);
+        }
+
+        set_field!(set_checksum_field, 0b1, 2);
+        set_field!(set_ports_field, 0b11, 0);
+
+        fn set_ports(&mut self, src_port: u16, dst_port: u16) {
+            let mut idx = 1;
+
+            match (src_port, dst_port) {
+                (0xf0b0..=0xf0bf, 0xf0b0..=0xf0bf) => {
+                    // We can compress both the source and destination ports.
+                    self.set_ports_field(0b11);
+                    let data = self.buffer.as_mut();
+                    data[idx] = (((src_port - 0xf0b0) as u8) << 4) & ((dst_port - 0xf0b0) as u8);
+                }
+                (0xf000..=0xf0ff, _) => {
+                    // We can compress the source port, but not the destination port.
+                    self.set_ports_field(0b10);
+                    let data = self.buffer.as_mut();
+                    data[idx] = (src_port - 0xf000) as u8;
+                    idx += 1;
+
+                    NetworkEndian::write_u16(&mut data[idx..idx + 2], dst_port);
+                }
+                (_, 0xf000..=0xf0ff) => {
+                    // We can compress the destination port, but not the source port.
+                    self.set_ports_field(0b01);
+                    let data = self.buffer.as_mut();
+                    NetworkEndian::write_u16(&mut data[idx..idx + 2], src_port);
+                    idx += 2;
+                    data[idx] = (dst_port - 0xf000) as u8;
+                }
+                (_, _) => {
+                    // We cannot compress any port.
+                    self.set_ports_field(0b00);
+                    let data = self.buffer.as_mut();
+                    NetworkEndian::write_u16(&mut data[idx..idx + 2], src_port);
+                    idx += 2;
+                    NetworkEndian::write_u16(&mut data[idx..idx + 2], dst_port);
+                }
+            };
+        }
+
+        fn set_checksum(&mut self, checksum: u16) {
+            self.set_checksum_field(0b0);
+            let idx = 1 + self.ports_size();
+            let data = self.buffer.as_mut();
+            NetworkEndian::write_u16(&mut data[idx..idx + 2], checksum);
+        }
+    }
+
+    /// A high-level representation of a LOWPAN_NHC UDP header.
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+    pub struct UdpNhcRepr(pub UdpRepr);
+
+    impl<'a> UdpNhcRepr {
+        /// Parse a LOWWPAN_NHC UDP packet and return a high-level representation.
+        pub fn parse<T: AsRef<[u8]> + ?Sized>(
+            packet: &UdpPacket<&'a T>,
+            src_addr: &ipv6::Address,
+            dst_addr: &ipv6::Address,
+            _checksum: Option<u16>,
+        ) -> Result<UdpNhcRepr> {
+            // Ensure basic accessors will work.
+            packet.check_len()?;
+
+            if packet.dispatch_field() != UDP_DISPATCH {
+                return Err(Error::Malformed);
+            }
+
+            let payload_len = packet.payload().len();
+            let chk_sum = !checksum::combine(&[
+                checksum::pseudo_header(
+                    &IpAddress::Ipv6(*src_addr),
+                    &IpAddress::Ipv6(*dst_addr),
+                    crate::wire::ip::Protocol::Udp,
+                    payload_len as u32 + 8,
+                ),
+                packet.src_port(),
+                packet.dst_port(),
+                payload_len as u16 + 8,
+                checksum::data(packet.payload()),
+            ]);
+
+            // TODO(thvdveld): remove the unwrap
+            if chk_sum != packet.checksum().unwrap() {
+                return Err(Error::Checksum);
+            }
+
+            Ok(UdpNhcRepr(UdpRepr {
+                src_port: packet.src_port(),
+                dst_port: packet.dst_port(),
+            }))
+        }
+
+        /// Return the length of a packet that will be emitted from this high-level representation.
+        pub fn header_len(&self) -> usize {
+            let mut len = 1; // The minimal header size
+
+            len += 2; // XXX We assume we will add the checksum at the end
+
+            // Check if we can compress the source and destination ports
+            match (self.src_port, self.dst_port) {
+                (0xf0b0..=0xf0bf, 0xf0b0..=0xf0bf) => len + 1,
+                (0xf000..=0xf0ff, _) | (_, 0xf000..=0xf0ff) => len + 3,
+                (_, _) => len + 4,
+            }
+        }
+
+        /// Emit a high-level representation into a LOWPAN_NHC UDP header.
+        pub fn emit<T: AsRef<[u8]> + AsMut<[u8]>>(
+            &self,
+            packet: &mut UdpPacket<T>,
+            src_addr: &Address,
+            dst_addr: &Address,
+            payload_len: usize,
+            emit_payload: impl FnOnce(&mut [u8]),
+        ) {
+            packet.set_dispatch_field();
+            packet.set_ports(self.src_port, self.dst_port);
+            emit_payload(packet.payload_mut());
+
+            let chk_sum = !checksum::combine(&[
+                checksum::pseudo_header(
+                    &IpAddress::Ipv6(*src_addr),
+                    &IpAddress::Ipv6(*dst_addr),
+                    crate::wire::ip::Protocol::Udp,
+                    payload_len as u32 + 8,
+                ),
+                self.src_port,
+                self.dst_port,
+                payload_len as u16 + 8,
+                checksum::data(packet.payload_mut()),
+            ]);
+
+            packet.set_checksum(chk_sum);
+        }
+    }
+
+    impl core::ops::Deref for UdpNhcRepr {
+        type Target = UdpRepr;
+
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+
+    impl core::ops::DerefMut for UdpNhcRepr {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+
+    #[cfg(test)]
+    mod test {
+        use super::*;
+
+        #[test]
+        fn ext_header_nhc_fields() {
+            let bytes = [0xe3, 0x06, 0x03, 0x00, 0xff, 0x00, 0x00, 0x00];
+
+            let packet = ExtensionHeaderPacket::new_checked(&bytes[..]).unwrap();
+            assert_eq!(packet.dispatch_field(), EXT_HEADER_DISPATCH);
+            assert_eq!(packet.length_field(), 6);
+            assert_eq!(
+                packet.extension_header_id(),
+                ExtensionHeaderId::RoutingHeader
+            );
+
+            assert_eq!(packet.payload(), [0x03, 0x00, 0xff, 0x00, 0x00, 0x00]);
+        }
+
+        #[test]
+        fn ext_header_emit() {
+            let ext_header = ExtensionHeaderRepr {
+                ext_header_id: ExtensionHeaderId::RoutingHeader,
+                next_header: NextHeader::Compressed,
+                length: 6,
+            };
+
+            let len = ext_header.buffer_len();
+            let mut buffer = [0u8; 127];
+            let mut packet = ExtensionHeaderPacket::new_unchecked(&mut buffer[..len]);
+            ext_header.emit(&mut packet);
+
+            assert_eq!(packet.dispatch_field(), EXT_HEADER_DISPATCH);
+            assert_eq!(packet.next_header(), NextHeader::Compressed);
+            assert_eq!(packet.length_field(), 6);
+            assert_eq!(
+                packet.extension_header_id(),
+                ExtensionHeaderId::RoutingHeader
+            );
+        }
+
+        #[test]
+        fn udp_nhc_fields() {
+            let bytes = [0xf0, 0x16, 0x2e, 0x22, 0x3d, 0x28, 0xc4];
+
+            let packet = UdpPacket::new_checked(&bytes[..]).unwrap();
+            assert_eq!(packet.dispatch_field(), UDP_DISPATCH);
+            assert_eq!(packet.checksum(), Some(0x28c4));
+            assert_eq!(packet.src_port(), 5678);
+            assert_eq!(packet.dst_port(), 8765);
+        }
+
+        #[test]
+        fn udp_emit() {
+            let udp = UdpNhcRepr(UdpRepr {
+                src_port: 0xf0b1,
+                dst_port: 0xf001,
+            });
+
+            let payload = b"Hello World!";
+
+            let src_addr = ipv6::Address::default();
+            let dst_addr = ipv6::Address::default();
+
+            let len = udp.header_len() + payload.len();
+            let mut buffer = [0u8; 127];
+            let mut packet = UdpPacket::new_unchecked(&mut buffer[..len]);
+            udp.emit(&mut packet, &src_addr, &dst_addr, payload.len(), |buf| {
+                buf.copy_from_slice(&payload[..])
+            });
+
+            assert_eq!(packet.dispatch_field(), UDP_DISPATCH);
+            assert_eq!(packet.src_port(), 0xf0b1);
+            assert_eq!(packet.dst_port(), 0xf001);
+            assert_eq!(packet.payload_mut(), b"Hello World!");
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    //use super::*;
+
+    //#[test]
+    //fn ieee802154_udp() {
+    //use crate::wire::ieee802154::Frame as Ieee802154Frame;
+    //use crate::wire::ieee802154::Repr as Ieee802154Repr;
+    //use crate::wire::ipv6routing;
+
+    //// This data is captured using Wireshark from the communication between a RPL 6LoWPAN server
+    //// and a RPL 6LoWPAN client.
+    //// The frame is thus an IEEE802.15.4 frame, containing a 6LoWPAN packet,
+    //// containing a RPL extension header and an UDP header.
+    //let bytes: &[u8] = &[
+    //0x61, 0xdc, 0xdd, 0xcd, 0xab, 0xc7, 0xd9, 0xb5, 0x14, 0x00, 0x4b, 0x12, 0x00, 0xbf,
+    //0x9b, 0x15, 0x06, 0x00, 0x4b, 0x12, 0x00, 0x7e, 0xf7, 0x00, 0xe3, 0x06, 0x03, 0x00,
+    //0xff, 0x00, 0x00, 0x00, 0xf0, 0x16, 0x2e, 0x22, 0x3d, 0x28, 0xc4, 0x68, 0x65, 0x6c,
+    //0x6c, 0x6f, 0x20, 0x36, 0x35, 0x18, 0xb9,
+    //];
+
+    //let ieee802154_frame = Ieee802154Frame::new_checked(bytes).unwrap();
+    //let ieee802154_repr = Ieee802154Repr::parse(&ieee802154_frame).unwrap();
+
+    //let iphc_frame = iphc::Packet::new_checked(ieee802154_frame.payload().unwrap()).unwrap();
+    //let iphc_repr = iphc::Repr::parse(
+    //&iphc_frame,
+    //ieee802154_repr.src_addr,
+    //ieee802154_repr.dst_addr,
+    //)
+    //.unwrap();
+
+    //// The next header is compressed.
+    //assert_eq!(iphc_repr.next_header, NextHeader::Compressed);
+
+    //// We dispatch the NHC packet.
+    //let nhc_packet = nhc::Packet::dispatch(iphc_frame.payload()).unwrap();
+
+    //let udp_payload = match nhc_packet {
+    //nhc::Packet::ExtensionHeader(ext_packet) => {
+    //// The next header is compressed (it is the UDP NHC compressed header).
+    //assert_eq!(ext_packet.next_header(), NextHeader::Compressed);
+    //assert_eq!(ext_packet.length_field(), 6);
+    //let payload = ext_packet.payload();
+
+    //let length = ext_packet.length_field() as usize;
+    //let ext_packet_payload = &payload[..length];
+
+    //match ext_packet.extension_header_id() {
+    //nhc::ExtensionHeaderId::RoutingHeader => {
+    //// We are not intersted in the Next Header protocol.
+    //let proto = ipv6::Protocol::Unknown(0);
+    //let mut new_payload = [0; 8];
+
+    //new_payload[0] = proto.into();
+    //new_payload[1] = (2 + length - 8) as u8;
+    //new_payload[2..].copy_from_slice(ext_packet_payload);
+
+    //let routing = ipv6routing::Header::new_checked(new_payload).unwrap();
+
+    //assert_eq!(routing.routing_type(), ipv6routing::Type::Rpl);
+    //assert_eq!(routing.segments_left(), 0);
+    //assert_eq!(routing.cmpr_e(), 0xf);
+    //assert_eq!(routing.cmpr_i(), 0xf);
+    //}
+    //_ => unreachable!(),
+    //}
+
+    //&payload[length..]
+    //}
+    //_ => unreachable!(),
+    //};
+
+    //let udp_nhc_frame = nhc::UdpPacket::new_checked(udp_payload).unwrap();
+    //let udp_repr = nhc::UdpNhcRepr::parse(
+    //&udp_nhc_frame,
+    //&iphc_repr.src_addr,
+    //&iphc_repr.dst_addr,
+    //None,
+    //)
+    //.unwrap();
+
+    //assert_eq!(udp_repr.src_port, 5678);
+    //assert_eq!(udp_repr.dst_port, 8765);
+    //assert_eq!(udp_nhc_frame.checksum(), Some(0x28c4));
+    //}
+}