package/linux-tools: add support for bpftool

This tool is available to be compiled since kernel 4.15.

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/linux-tools/Config.in

@@ -5,6 +5,28 @@ menu "Linux Kernel Tools"
 config BR2_PACKAGE_LINUX_TOOLS
 	bool
 
+config BR2_PACKAGE_LINUX_TOOLS_BPFTOOL
+	bool "bpftool"
+	depends on !BR2_nios2 # binutils
+	depends on BR2_USE_WCHAR # binutils, elfutils
+	depends on !BR2_STATIC_LIBS # elfutils
+	depends on BR2_TOOLCHAIN_HAS_THREADS # elfutils
+	depends on BR2_TOOLCHAIN_USES_UCLIBC || BR2_TOOLCHAIN_USES_GLIBC # elfutils
+	select BR2_PACKAGE_LINUX_TOOLS
+	select BR2_PACKAGE_BINUTILS
+	select BR2_PACKAGE_ELFUTILS
+	help
+	  bpftool is a tool for for inspection and simple manipulation
+	  of eBPF programs and maps.
+
+	  These tools are available only from kernel version 4.15.
+
+comment "bpftool needs a uClibc or glibc toolchain w/ wchar, dynamic library, threads"
+	depends on !BR2_nios2
+	depends on !BR2_USE_WCHAR || BR2_STATIC_LIBS \
+		|| !BR2_TOOLCHAIN_HAS_THREADS \
+		|| !(BR2_TOOLCHAIN_USES_UCLIBC || BR2_TOOLCHAIN_USES_GLIBC)
+
 config BR2_PACKAGE_LINUX_TOOLS_CPUPOWER
 	bool "cpupower"
 	select BR2_PACKAGE_LINUX_TOOLS

package/linux-tools/linux-tool-bpftool.mk.in

@@ -0,0 +1,37 @@
+################################################################################
+#
+# bpftool
+#
+################################################################################
+
+LINUX_TOOLS += bpftool
+
+BPFTOOL_DEPENDENCIES = binutils elfutils
+
+ifeq ($(BR2_PACKAGE_LIBCAP),y)
+BPFTOOL_DEPENDENCIES += libcap
+endif
+
+ifeq ($(BR2_PACKAGE_ZLIB),y)
+BPFTOOL_DEPENDENCIES += zlib
+endif
+
+BPFTOOL_MAKE_OPTS = $(LINUX_MAKE_FLAGS)
+
+define BPFTOOL_BUILD_CMDS
+	$(Q)if ! grep install $(LINUX_DIR)/tools/bpf/bpftool/Makefile >/dev/null 2>&1 ; then \
+		echo "Your kernel version is too old and does not have install section in the bpf tools." ; \
+		echo "At least kernel 4.15 must be used." ; \
+		exit 1 ; \
+	fi
+
+	$(TARGET_MAKE_ENV) $(MAKE1) -C $(LINUX_DIR)/tools/bpf/bpftool \
+		$(BPFTOOL_MAKE_OPTS)
+endef
+
+define BPFTOOL_INSTALL_TARGET_CMDS
+	$(TARGET_MAKE_ENV) $(MAKE1) -C $(LINUX_DIR)/tools/bpf/bpftool \
+		$(BPFTOOL_MAKE_OPTS) \
+		DESTDIR=$(TARGET_DIR) \
+		install
+endef