Add README and support build for all families

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

Makefile.deps

@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Try to include uAPI headers from the kernel uapi/ path.
+# Most code under tools/ requires the respective kernel uAPI headers
+# to be copied to tools/include. The duplication is annoying.
+# All the family headers should be self-contained. We avoid the copying
+# by selectively including just the uAPI header of the family directly
+# from the kernel sources.
+
+UAPI_PATH:=../
+
+# scripts/headers_install.sh strips "_UAPI" from header guards so we
+# need the explicit -D matching what's in /usr, to avoid multiple definitions.
+
+get_hdr_inc=-D$(1) -include $(UAPI_PATH)/linux/$(2)
+
+CFLAGS_devlink:=$(call get_hdr_inc,_LINUX_DEVLINK_H_,devlink.h)
+CFLAGS_dpll:=$(call get_hdr_inc,_LINUX_DPLL_H,dpll.h)
+CFLAGS_ethtool:=$(call get_hdr_inc,_LINUX_ETHTOOL_H,ethtool.h) \
+		$(call get_hdr_inc,_LINUX_ETHTOOL_NETLINK_H_,ethtool_netlink.h)
+CFLAGS_handshake:=$(call get_hdr_inc,_LINUX_HANDSHAKE_H,handshake.h)
+CFLAGS_mptcp_pm:=$(call get_hdr_inc,_LINUX_MPTCP_PM_H,mptcp_pm.h)
+CFLAGS_netdev:=$(call get_hdr_inc,_LINUX_NETDEV_H,netdev.h)
+CFLAGS_nlctrl:=$(call get_hdr_inc,__LINUX_GENERIC_NETLINK_H,genetlink.h)
+CFLAGS_nfsd:=$(call get_hdr_inc,_LINUX_NFSD_NETLINK_H,nfsd_netlink.h)
+CFLAGS_ovs_datapath:=$(call get_hdr_inc,__LINUX_OPENVSWITCH_H,openvswitch.h)
+CFLAGS_ovs_flow:=$(call get_hdr_inc,__LINUX_OPENVSWITCH_H,openvswitch.h)
+CFLAGS_ovs_vport:=$(call get_hdr_inc,__LINUX_OPENVSWITCH_H,openvswitch.h)
+CFLAGS_psp:=$(call get_hdr_inc,_LINUX_PSP_H,psp.h)
+CFLAGS_tcp_metrics:=$(call get_hdr_inc,_LINUX_TCP_METRICS_H,tcp_metrics.h)

README.rst

@@ -0,0 +1,26 @@
+Using ynl-cpp
+-------------
+
+YNL CPP is a best effort port of YNL C. Like YNL C is only supports
+static linking (because structs are auto-generated and may change
+version to version).
+
+The best way of using it in your project is probably git submodule.
+
+Building ynl-cpp
+----------------
+
+The repo supports building code for a specific family::
+
+  make -C generated/ netdev_lib.a
+
+or a big archive with code for all families::
+
+  make -C generated/
+
+Updating to latest kernel versions
+----------------------------------
+
+::
+
+   ./update-from-kernel.sh ../linux/

generated/Makefile

@@ -3,29 +3,58 @@
 CC=gcc
 CXX=g++
 CFLAGS=-std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow -I../lib/
-CXXFLAGS=-D_LINUX_ETHTOOL_H -I../lib/ -include../linux/ethtool_netlink.h  -include../linux/ethtool.h
 ifeq ("$(DEBUG)","1")
   CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan
 endif
 
-SRCS_ETHTOOL_CPP=$(wildcard ethtool-user.cpp)
-OBJS_ETHTOOL_CPP=$(patsubst %.cpp,%.o,${SRCS_ETHTOOL_CPP})
+CXXFLAGS=-I../lib/ -I../
+
+include ../Makefile.deps
+
+TOOL:=../ynl-gen-cpp.py
+
+GENS_PATHS=$(shell grep -nrI --files-without-match \
+		'protocol: netlink' ../Documentation/netlink/specs/)
+GENS_ALL=$(patsubst ../Documentation/netlink/specs/%.yaml,%,${GENS_PATHS})
+GENS=$(filter-out devlink ovs_datapath ovs_flow ovs_vport nlctrl,${GENS_ALL})
+SRCS=$(patsubst %,%-user.cpp,${GENS})
+HDRS=$(patsubst %,%-user.hpp,${GENS})
+OBJS=$(patsubst %,%-user.cpp.o,${GENS})
+LIBS=$(patsubst %,%_lib.a,${GENS})
 
 include $(wildcard *.d)
 
-all: ethtool_lib.a
+ifeq ($(V),1)
+Q =
+else
+Q = @
+endif
+
+all: $(LIBS)
+	@echo -e "\tAR libynl.a"
+	$(Q)ar rcs libynl.a $(OBJS)
+
+%-user.hpp: ../Documentation/netlink/specs/%.yaml $(TOOL)
+	@echo -e "\tGEN $@"
+	$(Q)$(TOOL) --mode user --header --spec $< -o $@ $(YNL_GEN_ARG_$*)
+
+%-user.cpp: ../Documentation/netlink/specs/%.yaml $(TOOL)
+	@echo -e "\tGEN $@"
+	$(Q)$(TOOL) --mode user --source --spec $< -o $@ $(YNL_GEN_ARG_$*)
 
-ethtool_lib.a: $@ $(OBJS_ETHTOOL_CPP)
-	ar rcs $@ $(OBJS_ETHTOOL_CPP)
+%-user.cpp.o: %-user.cpp %-user.hpp
+	@echo -e "\tCXX $@ "
+	$(Q)$(COMPILE.cpp) $(CFLAGS_$*) -MMD -c -o $@ $<
 
 clean:
 	rm -f *.o *.d *~
 
 distclean: clean
 	rm -f *.a
 
-%.cpp.o: %.cpp
-	$(COMPILE.cxx) -MMD -c -o $@ $<
+%_lib.a: $@ %-user.cpp.o
+	@echo -e "\tAR $@"
+	$(Q)ar rcs $@ $<
 
 .PHONY: all clean distclean
 .DEFAULT_GOAL=all