revise network integration and add support of futures

smoltcp 0.7 provides async/await waker support (smoltcp-rs/smoltcp#394).
I followed the example implementation https://github.com/embassy-rs/embassy/tree/net/embassy-net
to add waker support in hermit-sys.

However, hermit-sys can be used in a multi-threaded applications.
Consequently, the implementation must be thread safed. In addition,
we still have an "network thread", which is wakeup by an interrupt.
The thread wakeups all waiting future. If no future is available,
the thread calls directly the IP stack.

hermit-sys/Cargo.toml

@@ -34,8 +34,10 @@ llvm-tools = { version = "0.1" }
 
 [dependencies]
 log = { version = "0.4", default-features = false }
-lazy_static = "1.4.0"
 libm = { version = "0.2.1", default-features = false }
+futures = { version = "0.3.5" }
+futures-util = { version = "0.3.12" }
+lazy_static = "1.4"
 
 [target.'cfg(target_arch = "x86_64")'.dependencies.x86]
 version = "0.*"
@@ -49,9 +51,9 @@ default-features = false
 version = "0.7.0"
 optional = true
 default-features = false
-features = ["std", "ethernet", "socket-udp", "socket-tcp", "proto-ipv4", "proto-ipv6"]
+features = ["std", "ethernet", "socket-udp", "socket-tcp", "proto-ipv4", "proto-ipv6", "async"]
 # to increase the output the features log and verbose should be enabled
-#features = ["log", "verbose", "std", "ethernet", "socket-udp", "socket-tcp", "proto-ipv4", "proto-ipv6"]
+#features = ["log", "verbose", "std", "ethernet", "socket-udp", "socket-tcp", "proto-ipv4", "proto-ipv6", "async"]
 
 [dependencies.rftrace]
 version = "0.1.0"

hermit-sys/src/net/device.rs

@@ -7,6 +7,7 @@ use std::convert::TryInto;
 #[cfg(not(feature = "dhcpv4"))]
 use std::net::Ipv4Addr;
 use std::slice;
+use std::sync::Mutex;
 
 #[cfg(feature = "dhcpv4")]
 use smoltcp::dhcp::Dhcpv4Client;
@@ -24,7 +25,7 @@ use smoltcp::wire::IpAddress;
 use smoltcp::wire::Ipv4Cidr;
 use smoltcp::wire::{EthernetAddress, IpCidr, Ipv4Address};
 
-use crate::net::NetworkInterface;
+use crate::net::{NetworkInterface, NetworkState};
 
 extern "Rust" {
 	fn sys_get_mac_address() -> Result<[u8; 6], ()>;
@@ -44,18 +45,18 @@ pub struct HermitNet {
 }
 
 impl HermitNet {
-	pub fn new(mtu: u16) -> Self {
+	pub const fn new(mtu: u16) -> Self {
 		Self { mtu }
 	}
 }
 
 impl NetworkInterface<HermitNet> {
 	#[cfg(feature = "dhcpv4")]
-	pub fn new() -> Option<Self> {
+	pub fn new() -> NetworkState {
 		let mtu = match unsafe { sys_get_mtu() } {
 			Ok(mtu) => mtu,
 			Err(_) => {
-				return None;
+				return NetworkState::InitializationFailed;
 			}
 		};
 		let device = HermitNet::new(mtu);
@@ -67,7 +68,7 @@ impl NetworkInterface<HermitNet> {
 		let mac: [u8; 6] = match unsafe { sys_get_mac_address() } {
 			Ok(mac) => mac,
 			Err(_) => {
-				return None;
+				return NetworkState::InitializationFailed;
 			}
 		};
 
@@ -92,21 +93,20 @@ impl NetworkInterface<HermitNet> {
 			.routes(routes)
 			.finalize();
 
-		Some(Self {
+		NetworkState::Initialized(Mutex::new(Self {
 			iface,
 			sockets: sockets,
-			wait_for: BTreeMap::new(),
 			dhcp,
 			prev_cidr,
-		})
+		}))
 	}
 
 	#[cfg(not(feature = "dhcpv4"))]
-	pub fn new() -> Option<Self> {
+	pub fn new() -> NetworkState {
 		let mtu = match unsafe { sys_get_mtu() } {
 			Ok(mtu) => mtu,
 			Err(_) => {
-				return None;
+				return NetworkState::InitializationFailed;
 			}
 		};
 		let device = HermitNet::new(mtu);
@@ -118,7 +118,7 @@ impl NetworkInterface<HermitNet> {
 		let mac: [u8; 6] = match unsafe { sys_get_mac_address() } {
 			Ok(mac) => mac,
 			Err(_) => {
-				return None;
+				return NetworkState::InitializationFailed;
 			}
 		};
 		let myip: Ipv4Addr = HERMIT_IP.parse().expect("Unable to parse IPv4 address");
@@ -166,11 +166,10 @@ impl NetworkInterface<HermitNet> {
 			.routes(routes)
 			.finalize();
 
-		Some(Self {
+		NetworkState::Initialized(Mutex::new(Self {
 			iface,
 			sockets: SocketSet::new(vec![]),
-			wait_for: BTreeMap::new(),
-		})
+		}))
 	}
 }