net: add packet-trace feature.

ci.sh

@@ -35,7 +35,7 @@ cargo batch  \
     --- build --release --manifest-path embassy-executor/Cargo.toml --target riscv32imac-unknown-none-elf --features arch-riscv32,executor-thread,integrated-timers \
     --- build --release --manifest-path embassy-sync/Cargo.toml --target thumbv6m-none-eabi --features defmt \
     --- build --release --manifest-path embassy-time/Cargo.toml --target thumbv6m-none-eabi --features defmt,defmt-timestamp-uptime,generic-queue-8,mock-driver \
-    --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,proto-ipv4,medium-ethernet \
+    --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,proto-ipv4,medium-ethernet,packet-trace \
     --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,proto-ipv4,igmp,medium-ethernet \
     --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,dhcpv4,medium-ethernet \
     --- build --release --manifest-path embassy-net/Cargo.toml --target thumbv7em-none-eabi --features defmt,tcp,udp,dns,dhcpv4,medium-ethernet,dhcpv4-hostname \

embassy-net/Cargo.toml

@@ -28,6 +28,9 @@ std = []
 ## Enable defmt
 defmt = ["dep:defmt", "smoltcp/defmt", "embassy-net-driver/defmt", "heapless/defmt-03"]
 
+## Trace all raw received and transmitted packets using defmt or log.
+packet-trace = []
+
 #! Many of the following feature flags are re-exports of smoltcp feature flags. See 
 #! the [smoltcp feature flag documentation](https://github.com/smoltcp-rs/smoltcp#feature-flags)
 #! for more details

embassy-net/src/device.rs

@@ -76,7 +76,11 @@ where
     where
         F: FnOnce(&mut [u8]) -> R,
     {
-        self.0.consume(|buf| f(buf))
+        self.0.consume(|buf| {
+            #[cfg(feature = "packet-trace")]
+            trace!("rx: {:?}", buf);
+            f(buf)
+        })
     }
 }
 
@@ -92,6 +96,11 @@ where
     where
         F: FnOnce(&mut [u8]) -> R,
     {
-        self.0.consume(len, |buf| f(buf))
+        self.0.consume(len, |buf| {
+            let r = f(buf);
+            #[cfg(feature = "packet-trace")]
+            trace!("tx: {:?}", buf);
+            r
+        })
     }
 }