First pass constification of the wire module

Author: Nicholas Cyprus

src/wire/arp.rs

@@ -39,33 +39,33 @@ mod field {
     pub const OPER: Field = 6..8;
 
     #[inline]
-    pub fn SHA(hardware_len: u8, _protocol_len: u8) -> Field {
+    pub const fn SHA(hardware_len: u8, _protocol_len: u8) -> Field {
         let start = OPER.end;
         start..(start + hardware_len as usize)
     }
 
     #[inline]
-    pub fn SPA(hardware_len: u8, protocol_len: u8) -> Field {
+    pub const fn SPA(hardware_len: u8, protocol_len: u8) -> Field {
         let start = SHA(hardware_len, protocol_len).end;
         start..(start + protocol_len as usize)
     }
 
     #[inline]
-    pub fn THA(hardware_len: u8, protocol_len: u8) -> Field {
+    pub const fn THA(hardware_len: u8, protocol_len: u8) -> Field {
         let start = SPA(hardware_len, protocol_len).end;
         start..(start + hardware_len as usize)
     }
 
     #[inline]
-    pub fn TPA(hardware_len: u8, protocol_len: u8) -> Field {
+    pub const fn TPA(hardware_len: u8, protocol_len: u8) -> Field {
         let start = THA(hardware_len, protocol_len).end;
         start..(start + protocol_len as usize)
     }
 }
 
 impl<T: AsRef<[u8]>> Packet<T> {
     /// Imbue a raw octet buffer with ARP packet structure.
-    pub fn new_unchecked(buffer: T) -> Packet<T> {
+    pub const fn new_unchecked(buffer: T) -> Packet<T> {
         Packet { buffer }
     }
 
@@ -289,7 +289,7 @@ impl Repr {
     }
 
     /// Return the length of a packet that will be emitted from this high-level representation.
-    pub fn buffer_len(&self) -> usize {
+    pub const fn buffer_len(&self) -> usize {
         match *self {
             Repr::EthernetIpv4 { .. } => field::TPA(6, 4).end,
         }

src/wire/dhcpv4.rs

@@ -44,7 +44,7 @@ bitflags! {
 }
 
 impl MessageType {
-    fn opcode(&self) -> OpCode {
+    const fn opcode(&self) -> OpCode {
         match *self {
             MessageType::Discover
             | MessageType::Inform
@@ -233,7 +233,7 @@ pub(crate) mod field {
 
 impl<T: AsRef<[u8]>> Packet<T> {
     /// Imbue a raw octet buffer with DHCP packet structure.
-    pub fn new_unchecked(buffer: T) -> Packet<T> {
+    pub const fn new_unchecked(buffer: T) -> Packet<T> {
         Packet { buffer }
     }
 
@@ -1143,7 +1143,7 @@ mod test {
         assert_eq!(packet, DISCOVER_BYTES);
     }
 
-    fn offer_repr() -> Repr<'static> {
+    const fn offer_repr() -> Repr<'static> {
         Repr {
             message_type: MessageType::Offer,
             transaction_id: 0x3d1d,
@@ -1169,7 +1169,7 @@ mod test {
         }
     }
 
-    fn discover_repr() -> Repr<'static> {
+    const fn discover_repr() -> Repr<'static> {
         Repr {
             message_type: MessageType::Discover,
             transaction_id: 0x3d1d,

src/wire/dns.rs

@@ -83,7 +83,7 @@ pub struct Packet<T: AsRef<[u8]>> {
 
 impl<T: AsRef<[u8]>> Packet<T> {
     /// Imbue a raw octet buffer with DNS packet structure.
-    pub fn new_unchecked(buffer: T) -> Packet<T> {
+    pub const fn new_unchecked(buffer: T) -> Packet<T> {
         Packet { buffer }
     }
 
@@ -311,7 +311,7 @@ impl<'a> Question<'a> {
     }
 
     /// Return the length of a packet that will be emitted from this high-level representation.
-    pub fn buffer_len(&self) -> usize {
+    pub const fn buffer_len(&self) -> usize {
         self.name.len() + 4
     }
 
@@ -412,7 +412,7 @@ pub struct Repr<'a> {
 
 impl<'a> Repr<'a> {
     /// Return the length of a packet that will be emitted from this high-level representation.
-    pub fn buffer_len(&self) -> usize {
+    pub const fn buffer_len(&self) -> usize {
         field::HEADER_END + self.question.buffer_len()
     }
 

src/wire/ethernet.rs

@@ -43,7 +43,7 @@ impl Address {
     }
 
     /// Return an Ethernet address as a sequence of octets, in big-endian.
-    pub fn as_bytes(&self) -> &[u8] {
+    pub const fn as_bytes(&self) -> &[u8] {
         &self.0
     }
 
@@ -58,12 +58,12 @@ impl Address {
     }
 
     /// Query whether the "multicast" bit in the OUI is set.
-    pub fn is_multicast(&self) -> bool {
+    pub const fn is_multicast(&self) -> bool {
         self.0[0] & 0x01 != 0
     }
 
     /// Query whether the "locally administered" bit in the OUI is set.
-    pub fn is_local(&self) -> bool {
+    pub const fn is_local(&self) -> bool {
         self.0[0] & 0x02 != 0
     }
 }
@@ -100,7 +100,7 @@ pub const HEADER_LEN: usize = field::PAYLOAD.start;
 
 impl<T: AsRef<[u8]>> Frame<T> {
     /// Imbue a raw octet buffer with Ethernet frame structure.
-    pub fn new_unchecked(buffer: T) -> Frame<T> {
+    pub const fn new_unchecked(buffer: T) -> Frame<T> {
         Frame { buffer }
     }
 
@@ -131,13 +131,13 @@ impl<T: AsRef<[u8]>> Frame<T> {
     }
 
     /// Return the length of a frame header.
-    pub fn header_len() -> usize {
+    pub const fn header_len() -> usize {
         HEADER_LEN
     }
 
     /// Return the length of a buffer required to hold a packet with the payload
     /// of a given length.
-    pub fn buffer_len(payload_len: usize) -> usize {
+    pub const fn buffer_len(payload_len: usize) -> usize {
         HEADER_LEN + payload_len
     }
 
@@ -277,7 +277,7 @@ impl Repr {
     }
 
     /// Return the length of a header that will be emitted from this high-level representation.
-    pub fn buffer_len(&self) -> usize {
+    pub const fn buffer_len(&self) -> usize {
         HEADER_LEN
     }
 

src/wire/icmpv4.rs

@@ -184,7 +184,7 @@ mod field {
 
 impl<T: AsRef<[u8]>> Packet<T> {
     /// Imbue a raw octet buffer with ICMPv4 packet structure.
-    pub fn new_unchecked(buffer: T) -> Packet<T> {
+    pub const fn new_unchecked(buffer: T) -> Packet<T> {
         Packet { buffer }
     }
 
@@ -468,7 +468,7 @@ impl<'a> Repr<'a> {
     }
 
     /// Return the length of a packet that will be emitted from this high-level representation.
-    pub fn buffer_len(&self) -> usize {
+    pub const fn buffer_len(&self) -> usize {
         match self {
             &Repr::EchoRequest { data, .. } | &Repr::EchoReply { data, .. } => {
                 field::ECHO_SEQNO.end + data.len()

src/wire/icmpv6.rs

@@ -55,7 +55,7 @@ impl Message {
     /// is an [NDISC] message type.
     ///
     /// [NDISC]: https://tools.ietf.org/html/rfc4861
-    pub fn is_ndisc(&self) -> bool {
+    pub const fn is_ndisc(&self) -> bool {
         match *self {
             Message::RouterSolicit
             | Message::RouterAdvert
@@ -70,7 +70,7 @@ impl Message {
     /// is an [MLD] message type.
     ///
     /// [MLD]: https://tools.ietf.org/html/rfc3810
-    pub fn is_mld(&self) -> bool {
+    pub const fn is_mld(&self) -> bool {
         match *self {
             Message::MldQuery | Message::MldReport => true,
             _ => false,
@@ -247,7 +247,7 @@ pub(super) mod field {
 
 impl<T: AsRef<[u8]>> Packet<T> {
     /// Imbue a raw octet buffer with ICMPv6 packet structure.
-    pub fn new_unchecked(buffer: T) -> Packet<T> {
+    pub const fn new_unchecked(buffer: T) -> Packet<T> {
         Packet { buffer }
     }
 
@@ -625,7 +625,7 @@ impl<'a> Repr<'a> {
     }
 
     /// Return the length of a packet that will be emitted from this high-level representation.
-    pub fn buffer_len(&self) -> usize {
+    pub const fn buffer_len(&self) -> usize {
         match self {
             &Repr::DstUnreachable { header, data, .. }
             | &Repr::PktTooBig { header, data, .. }

src/wire/ieee802154.rs

@@ -43,7 +43,7 @@ enum_with_unknown! {
 
 impl AddressingMode {
     /// Return the size in octets of the address.
-    fn size(&self) -> usize {
+    const fn size(&self) -> usize {
         match self {
             AddressingMode::Absent => 0,
             AddressingMode::Short => 2,
@@ -103,11 +103,11 @@ impl Address {
         *self == Self::BROADCAST
     }
 
-    fn short_from_bytes(a: [u8; 2]) -> Self {
+    const fn short_from_bytes(a: [u8; 2]) -> Self {
         Self::Short(a)
     }
 
-    fn extended_from_bytes(a: [u8; 8]) -> Self {
+    const fn extended_from_bytes(a: [u8; 8]) -> Self {
         Self::Extended(a)
     }
 
@@ -125,7 +125,7 @@ impl Address {
         }
     }
 
-    pub fn as_bytes(&self) -> &[u8] {
+    pub const fn as_bytes(&self) -> &[u8] {
         match self {
             Address::Absent => &[],
             Address::Short(value) => value,
@@ -224,7 +224,7 @@ macro_rules! set_fc_bit_field {
 
 impl<T: AsRef<[u8]>> Frame<T> {
     /// Input a raw octet buffer with Ethernet frame structure.
-    pub fn new_unchecked(buffer: T) -> Frame<T> {
+    pub const fn new_unchecked(buffer: T) -> Frame<T> {
         Frame { buffer }
     }
 
@@ -784,7 +784,7 @@ impl Repr {
 
     /// 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 {
+    pub const fn buffer_len(&self) -> usize {
         3 + 2
             + match self.dst_addr {
                 Some(Address::Absent) | None => 0,

src/wire/igmp.rs

@@ -54,7 +54,7 @@ impl fmt::Display for Message {
 /// [RFC 2236]: https://tools.ietf.org/html/rfc2236
 impl<T: AsRef<[u8]>> Packet<T> {
     /// Imbue a raw octet buffer with IGMPv2 packet structure.
-    pub fn new_unchecked(buffer: T) -> Packet<T> {
+    pub const fn new_unchecked(buffer: T) -> Packet<T> {
         Packet { buffer }
     }
 
@@ -246,7 +246,7 @@ impl Repr {
     }
 
     /// Return the length of a packet that will be emitted from this high-level representation.
-    pub fn buffer_len(&self) -> usize {
+    pub const fn buffer_len(&self) -> usize {
         // always 8 bytes
         field::GROUP_ADDRESS.end
     }
@@ -304,7 +304,7 @@ fn max_resp_code_to_duration(value: u8) -> Duration {
     Duration::from_millis(decisecs * 100)
 }
 
-fn duration_to_max_resp_code(duration: Duration) -> u8 {
+const fn duration_to_max_resp_code(duration: Duration) -> u8 {
     let decisecs = duration.total_millis() / 100;
     if decisecs < 128 {
         decisecs as u8