net: don't depend directly on smoltcp outside embassy-net

examples/std/Cargo.toml

@@ -17,8 +17,3 @@ libc = "0.2.101"
 clap = { version = "3.0.0-beta.5", features = ["derive"] }
 rand_core   = { version = "0.6.3", features = ["std"] }
 heapless            = { version = "0.7.5", default-features = false }
-
-[dependencies.smoltcp]
-git = "https://github.com/bobmcwhirter/smoltcp"
-rev = "faf81d21daae16b650b16e59a8422a8283e8a302"
-default-features = false

examples/std/src/tuntap.rs

@@ -1,7 +1,5 @@
 use async_io::Async;
-use libc;
 use log::*;
-use smoltcp::wire::EthernetFrame;
 use std::io;
 use std::io::{Read, Write};
 use std::os::unix::io::{AsRawFd, RawFd};
@@ -14,6 +12,8 @@ pub const _IFF_TUN: libc::c_int = 0x0001;
 pub const IFF_TAP: libc::c_int = 0x0002;
 pub const IFF_NO_PI: libc::c_int = 0x1000;
 
+const ETHERNET_HEADER_LEN: usize = 14;
+
 #[repr(C)]
 #[derive(Debug)]
 struct ifreq {
@@ -85,7 +85,7 @@ impl TunTap {
 
             // 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.
-            let mtu = ip_mtu + EthernetFrame::<&[u8]>::header_len();
+            let mtu = ip_mtu + ETHERNET_HEADER_LEN;
 
             Ok(TunTap { fd, mtu })
         }

examples/stm32f7/Cargo.toml

@@ -25,15 +25,3 @@ heapless = { version = "0.7.5", default-features = false }
 nb = "1.0.0"
 rand_core = "0.6.3"
 critical-section = "0.2.3"
-
-
-[dependencies.smoltcp]
-git = "https://github.com/bobmcwhirter/smoltcp"
-rev = "faf81d21daae16b650b16e59a8422a8283e8a302"
-default-features = false
-features = [
-    "proto-ipv4",
-    "socket",
-    "async",
-    "defmt",
-]

examples/stm32h7/Cargo.toml

@@ -26,16 +26,4 @@ futures = { version = "0.3.17", default-features = false, features = ["async-awa
 heapless = { version = "0.7.5", default-features = false }
 rand_core = "0.6.3"
 critical-section = "0.2.5"
-
 micromath = "2.0.0"
-
-[dependencies.smoltcp]
-git = "https://github.com/bobmcwhirter/smoltcp"
-rev = "faf81d21daae16b650b16e59a8422a8283e8a302"
-default-features = false
-features = [
-  "proto-ipv4",
-  "socket",
-  "async",
-  "defmt",
-]