Initial commit

Makefile

@@ -0,0 +1,112 @@
+# SPDX-License-Identifier: MIT
+#
+# Makefile for eBPF Port Knocking Programs
+# Supports both Linux (using libbpf) and Windows eBPF (using eBPF for Windows)
+#
+
+# Detect platform
+ifeq ($(OS),Windows_NT)
+    PLATFORM := windows
+    EBPF_SDK_DIR := C:/Users/vagrant/Downloads/ebpf-for-windows
+else
+    UNAME_S := $(shell uname -s)
+    ifeq ($(UNAME_S),Linux)
+        PLATFORM := linux
+        EBPF_SDK_DIR := /home/tlh/VMs/ebpf-for-windows
+    else
+        $(error Unsupported platform: $(UNAME_S))
+    endif
+endif
+
+# Directories
+SRC_DIR := .
+OUT_DIR := out
+INCLUDE_DIR := include
+
+# Toolchain
+CLANG := clang
+
+# Output files
+BPF_OBJ_LINUX := $(OUT_DIR)/port_knock_linux.o
+BPF_OBJ_WINDOWS := $(OUT_DIR)/port_knock.o
+
+# Compiler flags
+COMMON_FLAGS := -Wall -Wextra -Wno-unused-value -O2 -g
+
+# Linux-specific flags
+LINUX_CFLAGS := -D__TARGET_ARCH_x86 -D__LINUX_BPF__ $(COMMON_FLAGS)
+LINUX_INCLUDES := -I/usr/include/bpf -I/usr/include -I$(INCLUDE_DIR)
+
+# Windows-specific flags
+# Point to eBPF for Windows SDK headers
+WINDOWS_CFLAGS := -D_WIN32 $(COMMON_FLAGS)
+WINDOWS_INCLUDES := -I$(INCLUDE_DIR) -I$(EBPF_SDK_DIR)/include -I$(EBPF_SDK_DIR)/tests/include
+
+.PHONY: all clean build-linux build-windows make-windows help
+
+# Default target - show help
+all: help
+
+# Linux build
+build-linux: $(BPF_OBJ_LINUX)
+
+make-windows: $(BPF_OBJ_WINDOWS)
+
+$(OUT_DIR):
+	mkdir -p $(OUT_DIR)
+
+$(BPF_OBJ_LINUX): $(SRC_DIR)/port_knock.c $(INCLUDE_DIR)/common.h | $(OUT_DIR)
+	@echo "=== Building eBPF for Linux ==="
+	$(CLANG) $(LINUX_CFLAGS) $(LINUX_INCLUDES) \
+		-target bpf \
+		-D__BPF_TRACING__ \
+		-c $< -o $@
+	@echo "Built: $@"
+	@echo "  Sections: $$(bpftool prog show $$@ 2>/dev/null || echo '  (use bpftool to inspect)')"
+
+# Windows build (using eBPF for Windows)
+build-windows: $(BPF_OBJ_WINDOWS)
+
+$(BPF_OBJ_WINDOWS): $(SRC_DIR)/port_knock.c $(INCLUDE_DIR)/common.h | $(OUT_DIR)
+	@echo "=== Building eBPF for Windows ==="
+	$(CLANG) $(WINDOWS_CFLAGS) $(WINDOWS_INCLUDES) \
+		-target bpf \
+		-c $< -o $@
+	@echo "Built: $@"
+
+# Verify program
+verify: $(BPF_OBJ_LINUX)
+	@echo "=== Verifying eBPF program ==="
+	@bpftool prog show $(BPF_OBJ_LINUX) 2>/dev/null || echo "Use bpftool to verify"
+
+# Show sections
+show-sections: $(BPF_OBJ_LINUX)
+	@bpftool prog show $(BPF_OBJ_LINUX)
+
+# Show disassembly
+show-disasm: $(BPF_OBJ_LINUX)
+	@bpftool prog disasm $(BPF_OBJ_LINUX)
+
+# Clean
+clean:
+	rm -rf $(OUT_DIR)
+
+# Help
+help:
+	@echo "eBPF Port Knocking Program - Build System"
+	@echo ""
+	@echo "Targets:"
+	@echo "  build-linux     Build for Linux eBPF (using libbpf/aya)"
+	@echo "  build-windows   Build for Windows eBPF (using eBPF for Windows)"
+	@echo "  verify          Verify the compiled program"
+	@echo "  show-sections   Show eBPF program sections"
+	@echo "  show-disasm     Show disassembly of the program"
+	@echo "  clean           Remove build artifacts"
+	@echo ""
+	@echo "Usage:"
+	@echo "  Linux:   make build-linux"
+	@echo "  Windows: make build-windows"
+	@echo ""
+	@echo "Prerequisites:"
+	@echo "  Linux:   clang, libbpf, bpftool"
+	@echo "  Windows: clang, eBPF for Windows SDK (at Z:/ebpf-for-windows)"