Add ethernet feature-gate as default.

Disable ethernet-related features and framing based on a feature gate.

Add a no-ethernet option to Travis.

notes:
- allow(unused) is added when not using ethernet feature
- Don't run pretty-print doctest, ethernet is optional.

Closes: #308
Approved by: whitequark

.travis.yml

@@ -12,32 +12,35 @@ matrix:
       env: FEATURES='default' MODE='test'
     ### Test select feature permutations, chosen to be as orthogonal as possible
     - rust: nightly
-      env: FEATURES='std phy-raw_socket proto-ipv6 socket-udp' MODE='test'
+      env: FEATURES='std ethernet phy-raw_socket proto-ipv6 socket-udp' MODE='test'
     - rust: nightly
-      env: FEATURES='std phy-tap_interface proto-ipv6 socket-udp' MODE='test'
+      env: FEATURES='std ethernet phy-tap_interface proto-ipv6 socket-udp' MODE='test'
     - rust: nightly
-      env: FEATURES='std proto-ipv4 proto-igmp socket-raw' MODE='test'
+      env: FEATURES='std ethernet proto-ipv4 proto-igmp socket-raw' MODE='test'
     - rust: nightly
-      env: FEATURES='std proto-ipv4 socket-udp socket-tcp' MODE='test'
+      env: FEATURES='std ethernet proto-ipv4 socket-udp socket-tcp' MODE='test'
     - rust: nightly
-      env: FEATURES='std proto-ipv4 proto-dhcpv4 socket-udp' MODE='test'
+      env: FEATURES='std ethernet proto-ipv4 proto-dhcpv4 socket-udp' MODE='test'
     - rust: nightly
-      env: FEATURES='std proto-ipv6 socket-udp' MODE='test'
+      env: FEATURES='std ethernet proto-ipv6 socket-udp' MODE='test'
     - rust: nightly
-      env: FEATURES='std proto-ipv6 socket-tcp' MODE='test'
+      env: FEATURES='std ethernet proto-ipv6 socket-tcp' MODE='test'
     - rust: nightly
-      env: FEATURES='std proto-ipv4 socket-icmp socket-tcp' MODE='test'
+      env: FEATURES='std ethernet proto-ipv4 socket-icmp socket-tcp' MODE='test'
     - rust: nightly
-      env: FEATURES='std proto-ipv6 socket-icmp socket-tcp' MODE='test'
+      env: FEATURES='std ethernet proto-ipv6 socket-icmp socket-tcp' MODE='test'
     ### Test select feature permutations, chosen to be as aggressive as possible
     - rust: nightly
-      env: FEATURES='proto-ipv4 proto-ipv6 socket-raw socket-udp socket-tcp socket-icmp std'
+      env: FEATURES='ethernet proto-ipv4 proto-ipv6 socket-raw socket-udp socket-tcp socket-icmp std'
+        MODE='test'
+    - rust: nightly
+      env: FEATURES='ethernet proto-ipv4 proto-ipv6 socket-raw socket-udp socket-tcp socket-icmp alloc'
         MODE='test'
     - rust: nightly
       env: FEATURES='proto-ipv4 proto-ipv6 socket-raw socket-udp socket-tcp socket-icmp alloc'
         MODE='test'
     - rust: nightly
-      env: FEATURES='proto-ipv4 proto-ipv6 proto-igmp proto-dhcpv4 socket-raw socket-udp socket-tcp socket-icmp'
+      env: FEATURES='ethernet proto-ipv4 proto-ipv6 proto-igmp proto-dhcpv4 socket-raw socket-udp socket-tcp socket-icmp'
         MODE='build'
     - rust: nightly
       env: MODE='fuzz run' ARGS='packet_parser -- -max_len=1536 -max_total_time=30'

Cargo.toml

@@ -31,6 +31,7 @@ url = "1.0"
 std = ["managed/std"]
 alloc = ["managed/alloc"]
 verbose = []
+ethernet = []
 "phy-raw_socket" = ["std", "libc"]
 "phy-tap_interface" = ["std", "libc"]
 "proto-ipv4" = []
@@ -43,6 +44,7 @@ verbose = []
 "socket-icmp" = []
 default = [
   "std", "log", # needed for `cargo test --no-default-features --features default` :/
+  "ethernet",
   "phy-raw_socket", "phy-tap_interface",
   "proto-ipv4", "proto-igmp", "proto-ipv6",
   "socket-raw", "socket-icmp", "socket-udp", "socket-tcp"

src/iface/mod.rs

@@ -4,13 +4,19 @@ The `iface` module deals with the *network interfaces*. It filters incoming fram
 provides lookup and caching of hardware addresses, and handles management packets.
 */
 
+#[cfg(feature = "ethernet")]
 mod neighbor;
 mod route;
+#[cfg(feature = "ethernet")]
 mod ethernet;
 
+#[cfg(feature = "ethernet")]
 pub use self::neighbor::Neighbor as Neighbor;
+#[cfg(feature = "ethernet")]
 pub(crate) use self::neighbor::Answer as NeighborAnswer;
+#[cfg(feature = "ethernet")]
 pub use self::neighbor::Cache as NeighborCache;
 pub use self::route::{Route, Routes};
+#[cfg(feature = "ethernet")]
 pub use self::ethernet::{Interface as EthernetInterface,
                          InterfaceBuilder as EthernetInterfaceBuilder};

src/lib.rs

@@ -1,7 +1,7 @@
 #![cfg_attr(feature = "alloc", feature(alloc))]
 #![no_std]
 #![deny(unsafe_code)]
-#![cfg_attr(any(feature = "proto-ipv4", feature = "proto-ipv6"), deny(unused))]
+#![cfg_attr(all(any(feature = "proto-ipv4", feature = "proto-ipv6"), feature = "ethernet"), deny(unused))]
 
 //! The _smoltcp_ library is built in a layered structure, with the layers corresponding
 //! to the levels of API abstraction. Only the highest layers would be used by a typical
@@ -91,7 +91,7 @@ compile_error!("at least one socket needs to be enabled"); */
 // FIXME(dlrobertson): clippy fails with this lint
 #![cfg_attr(feature = "cargo-clippy", allow(if_same_then_else))]
 
-#[cfg(feature = "proto-ipv6")]
+#[cfg(all(feature = "proto-ipv6", feature = "ethernet"))]
 #[macro_use]
 extern crate bitflags;
 extern crate byteorder;

src/parsers.rs

@@ -3,7 +3,9 @@
 use core::str::FromStr;
 use core::result;
 
-use wire::{EthernetAddress, IpAddress, IpCidr, IpEndpoint};
+#[cfg(feature = "ethernet")]
+use wire::EthernetAddress;
+use wire::{IpAddress, IpCidr, IpEndpoint};
 #[cfg(feature = "proto-ipv4")]
 use wire::{Ipv4Address, Ipv4Cidr};
 #[cfg(feature = "proto-ipv6")]
@@ -116,6 +118,7 @@ impl<'a> Parser<'a> {
         }
     }
 
+    #[cfg(feature = "ethernet")]
     fn accept_mac_joined_with(&mut self, separator: u8) -> Result<EthernetAddress> {
         let mut octets = [0u8; 6];
         for n in 0..6 {
@@ -127,6 +130,7 @@ impl<'a> Parser<'a> {
         Ok(EthernetAddress(octets))
     }
 
+    #[cfg(feature = "ethernet")]
     fn accept_mac(&mut self) -> Result<EthernetAddress> {
         if let Some(mac) = self.try(|p| p.accept_mac_joined_with(b'-')) {
             return Ok(mac)
@@ -344,6 +348,7 @@ impl<'a> Parser<'a> {
     }
 }
 
+#[cfg(feature = "ethernet")]
 impl FromStr for EthernetAddress {
     type Err = ();
 
@@ -462,7 +467,7 @@ mod test {
     }
 
     #[test]
-    #[cfg(feature = "proto-ipv4")]
+    #[cfg(all(feature = "proto-ipv4", feature = "ethernet"))]
     fn test_mac() {
         assert_eq!(EthernetAddress::from_str(""), Err(()));
         assert_eq!(EthernetAddress::from_str("02:00:00:00:00:00"),

src/phy/mod.rs

@@ -115,6 +115,7 @@ pub use self::raw_socket::RawSocket;
 #[cfg(all(feature = "phy-tap_interface", target_os = "linux"))]
 pub use self::tap_interface::TapInterface;
 
+#[cfg(feature = "ethernet")]
 /// A tracer device for Ethernet frames.
 pub type EthernetTracer<T> = Tracer<T, super::wire::EthernetFrame<&'static [u8]>>;
 

src/wire/icmpv6.rs

@@ -5,7 +5,9 @@ use {Error, Result};
 use phy::ChecksumCapabilities;
 use super::ip::checksum;
 use super::{IpAddress, IpProtocol, Ipv6Packet, Ipv6Repr};
-use super::{MldRepr, NdiscRepr};
+use super::MldRepr;
+#[cfg(feature = "ethernet")]
+use super::NdiscRepr;
 
 enum_with_unknown! {
     /// Internet protocol control message type.
@@ -537,6 +539,7 @@ pub enum Repr<'a> {
         seq_no: u16,
         data:   &'a [u8]
     },
+    #[cfg(feature = "ethernet")]
     Ndisc(NdiscRepr<'a>),
     Mld(MldRepr<'a>),
     #[doc(hidden)]
@@ -619,6 +622,7 @@ impl<'a> Repr<'a> {
                     data:   packet.payload()
                 })
             },
+            #[cfg(feature = "ethernet")]
             (msg_type, 0) if msg_type.is_ndisc() => {
                 NdiscRepr::parse(packet).map(|repr| Repr::Ndisc(repr))
             },
@@ -640,6 +644,7 @@ impl<'a> Repr<'a> {
             &Repr::EchoReply { data, .. } => {
                 field::ECHO_SEQNO.end + data.len()
             },
+            #[cfg(feature = "ethernet")]
             &Repr::Ndisc(ndisc) => {
                 ndisc.buffer_len()
             },
@@ -711,6 +716,7 @@ impl<'a> Repr<'a> {
                 packet.payload_mut()[..data_len].copy_from_slice(&data[..data_len])
             },
 
+            #[cfg(feature = "ethernet")]
             &Repr::Ndisc(ndisc) => {
                 ndisc.emit(packet)
             },

src/wire/mod.rs

@@ -77,8 +77,9 @@ mod field {
 
 pub mod pretty_print;
 
+#[cfg(feature = "ethernet")]
 mod ethernet;
-#[cfg(feature = "proto-ipv4")]
+#[cfg(all(feature = "proto-ipv4", feature = "ethernet"))]
 mod arp;
 pub(crate) mod ip;
 #[cfg(feature = "proto-ipv4")]
@@ -101,9 +102,9 @@ mod icmpv6;
 mod icmp;
 #[cfg(feature = "proto-igmp")]
 mod igmp;
-#[cfg(feature = "proto-ipv6")]
+#[cfg(all(feature = "proto-ipv6", feature = "ethernet"))]
 mod ndisc;
-#[cfg(feature = "proto-ipv6")]
+#[cfg(all(feature = "proto-ipv6", feature = "ethernet"))]
 mod ndiscoption;
 #[cfg(feature = "proto-ipv6")]
 mod mld;
@@ -114,12 +115,13 @@ pub(crate) mod dhcpv4;
 
 pub use self::pretty_print::PrettyPrinter;
 
+#[cfg(feature = "ethernet")]
 pub use self::ethernet::{EtherType as EthernetProtocol,
                          Address as EthernetAddress,
                          Frame as EthernetFrame,
                          Repr as EthernetRepr};
 
-#[cfg(feature = "proto-ipv4")]
+#[cfg(all(feature = "proto-ipv4", feature = "ethernet"))]
 pub use self::arp::{Hardware as ArpHardware,
                     Operation as ArpOperation,
                     Packet as ArpPacket,
@@ -190,12 +192,12 @@ pub use self::icmpv6::{Message as Icmpv6Message,
 pub use self::icmp::Repr as IcmpRepr;
 
 
-#[cfg(feature = "proto-ipv6")]
+#[cfg(all(feature = "proto-ipv6", feature = "ethernet"))]
 pub use self::ndisc::{Repr as NdiscRepr,
                       RouterFlags as NdiscRouterFlags,
                       NeighborFlags as NdiscNeighborFlags};
 
-#[cfg(feature = "proto-ipv6")]
+#[cfg(all(feature = "proto-ipv6", feature = "ethernet"))]
 pub use self::ndiscoption::{NdiscOption,
                             Repr as NdiscOptionRepr,
                             Type as NdiscOptionType,

src/wire/pretty_print.rs

@@ -7,7 +7,7 @@ easily human readable packet listings.
 
 A packet can be formatted using the `PrettyPrinter` wrapper:
 
-```rust
+```rust,ignore
 use smoltcp::wire::*;
 let buffer = vec![
     // Ethernet II