windows: automate update of external dependencies

Add a script which automatically fetches ebpf_structs.h and regenerates
asm/func_win.go from it.

Break out the stringer invocation into a separate step because efW made
a breaking change to function names, which breaks the subsequent build.

Signed-off-by: Lorenz Bauer <[email protected]>

Author: lmb

Makefile

@@ -98,8 +98,9 @@ all: format $(addsuffix -el.elf,$(TARGETS)) $(addsuffix -eb.elf,$(TARGETS)) gene
 	ln -srf testdata/loader-$(CLANG)-eb.elf testdata/loader-eb.elf
 
 generate:
+	go generate -run "stringer" ./...
 	go generate -run "gentypes" ./...
-	go generate -skip "gentypes" ./...
+	go generate -skip "(gentypes|stringer)" ./...
 
 testdata/loader-%-el.elf: testdata/loader.c
 	$* $(CFLAGS) -target bpfel -c $< -o $@
@@ -117,8 +118,10 @@ testdata/loader-%-eb.elf: testdata/loader.c
 	$(CLANG) $(CFLAGS) -target bpfeb -c $< -o $@
 	$(STRIP) -g $@
 
-.PHONY: update-kernel-deps
-update-kernel-deps: export KERNEL_VERSION?=6.16.0
-update-kernel-deps:
-	./testdata/sh/update-kernel-deps.sh
+.PHONY: update-external-deps
+update-external-deps: export KERNEL_VERSION=6.16.0
+update-external-deps: export EFW_VERSION=v1.0.0-rc1
+update-external-deps:
+	./scripts/update-kernel-deps.sh
+	./scripts/update-efw-deps.sh
 	$(MAKE) container-all

asm/func_string.go

@@ -61,15 +61,15 @@ variables:
 make CONTAINER_ENGINE=podman CONTAINER_RUN_ARGS=
 ```
 
-### Updating kernel dependencies
+### Updating external dependencies
 
 Syscall bindings and some parameters required to parse ELF sections are derived
 from upstream kernel versions. You can update them to the latest version by:
 
 1. Adjusting the `KERNEL_VERSION` variable in `Makefile`
 2. Running
     ```shell-session
-    make update-kernel-deps
+    make update-external-deps
     ```
 
 Finally, bump the tested kernels in `.github/workflows/ci.yml`

asm/func_win.go

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+set -euo pipefail
+
+tmp=$(mktemp -d)
+
+cleanup() {
+	rm -r "$tmp"
+}
+
+trap cleanup EXIT
+
+# Download and process ebpf_structs.h
+curl -fL "https://github.com/microsoft/ebpf-for-windows/raw/refs/tags/${EFW_VERSION}/include/ebpf_structs.h" -o "$tmp/ebpf_structs.h"
+"./internal/cmd/genwinfunctions.awk" "$tmp/ebpf_structs.h" | gofmt > "./asm/func_win.go"