Revert "iproute2: simplify linking libelf for eBFP/XDP object file support"

This reverts commit 26681fa6a6 as it breaks the
installation of the iproute2 utilities ip-bridge, ss, nstat, devlink and rdma
for the ip-full variant

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

package/network/utils/iproute2/Makefile

@@ -49,7 +49,7 @@ $(call Package/iproute2/Default)
  VARIANT:=full
  PROVIDES:=ip
  ALTERNATIVES:=300:/sbin/ip:/usr/libexec/ip-full
- DEPENDS:=+libnl-tiny +libelf +(PACKAGE_devlink||PACKAGE_rdma):libmnl
+ DEPENDS:=+libnl-tiny +(PACKAGE_devlink||PACKAGE_rdma):libmnl
 endef
 
 define Package/tc
@@ -100,14 +100,6 @@ ifeq ($(BUILD_VARIANT),tiny)
   IP_CONFIG_TINY:=y
 endif
 
-ifeq ($(BUILD_VARIANT),full)
-  HAVE_ELF:=y
-endif
-
-ifeq ($(BUILD_VARIANT),tc)
-  HAVE_ELF:=y
-endif
-
 ifdef CONFIG_PACKAGE_devlink
   HAVE_MNL:=y
 endif
@@ -129,7 +121,6 @@ MAKE_FLAGS += \
 	KERNEL_INCLUDE="$(LINUX_DIR)/user_headers/include" \
 	SHARED_LIBS="" \
 	IP_CONFIG_TINY=$(IP_CONFIG_TINY) \
-	HAVE_ELF=$(HAVE_ELF) \
 	HAVE_MNL=$(HAVE_MNL) \
 	IPT_LIB_DIR=/usr/lib/iptables \
 	XT_LIB_DIR=/usr/lib/iptables \

package/network/utils/iproute2/patches/145-keep_libelf_optional.patch

@@ -1,11 +0,0 @@
---- a/configure
-+++ b/configure
-@@ -228,7 +228,7 @@ EOF
- 
- check_elf()
- {
--    if ${PKG_CONFIG} libelf --exists; then
-+    if [ "${HAVE_ELF}" = "y" ] && ${PKG_CONFIG} libelf --exists; then
- 	echo "HAVE_ELF:=y" >>$CONFIG
- 	echo "yes"
- 

package/network/utils/iproute2/patches/190-link-libelf-to-tc-only.patch

@@ -0,0 +1,60 @@
+--- a/configure
++++ b/configure
+@@ -231,8 +231,9 @@ check_elf()
+ 	echo "HAVE_ELF:=y" >>$CONFIG
+ 	echo "yes"
+ 
+-	echo 'CFLAGS += -DHAVE_ELF' `${PKG_CONFIG} libelf --cflags` >> $CONFIG
+-	echo 'LDLIBS += ' `${PKG_CONFIG} libelf --libs` >>$CONFIG
++	echo 'CFLAGS += -DHAVE_ELF' >> $CONFIG
++	echo 'ELF_CFLAGS += ' `${PKG_CONFIG} libelf --cflags` >> $CONFIG
++	echo 'ELF_LDLIBS += ' `${PKG_CONFIG} libelf --libs` >>$CONFIG
+     else
+ 	echo "no"
+     fi
+--- a/lib/Makefile
++++ b/lib/Makefile
+@@ -11,9 +11,17 @@ UTILOBJ = utils.o rt_names.o ll_map.o ll
+ 	inet_proto.o namespace.o json_writer.o json_print.o \
+ 	names.o color.o bpf.o exec.o fs.o
+ 
++ELFOBJ=$(patsubst %.o,%.elf.o,$(UTILOBJ))
++
+ NLOBJ=libgenl.o libnetlink.o
+ 
+-all: libnetlink.a libutil.a
++all: libnetlink.a libutil.a libutil-elf.a
++
++%.o: %.c
++	$(QUIET_CC)$(CC) $(CFLAGS) -UHAVE_ELF $(EXTRA_CFLAGS) -c -o $@ $<
++
++%.elf.o: %.c
++	$(QUIET_CC)$(CC) $(CFLAGS) $(ELF_CFLAGS) $(EXTRA_CFLAGS) -c -o $@ $<
+ 
+ libnetlink.a: $(NLOBJ)
+ 	$(QUIET_AR)$(AR) rcs $@ $^
+@@ -21,7 +29,10 @@ libnetlink.a: $(NLOBJ)
+ libutil.a: $(UTILOBJ) $(ADDLIB)
+ 	$(QUIET_AR)$(AR) rcs $@ $^
+ 
++libutil-elf.a: $(ELFOBJ) $(ADDLIB)
++	$(QUIET_AR)$(AR) rcs $@ $^
++
+ install:
+ 
+ clean:
+-	rm -f $(NLOBJ) $(UTILOBJ) $(ADDLIB) libnetlink.a libutil.a
++	rm -f $(NLOBJ) $(UTILOBJ) $(ELFOBJ) $(ADDLIB) libnetlink.a libutil.a libutil-elf.a
+--- a/tc/Makefile
++++ b/tc/Makefile
+@@ -133,8 +133,8 @@ MODDESTDIR := $(DESTDIR)$(LIBDIR)/tc
+ 
+ all: tc $(TCSO)
+ 
+-tc: $(TCOBJ) $(LIBNETLINK) libtc.a
+-	$(QUIET_LINK)$(CC) $^ $(LDFLAGS) $(LDLIBS) -o $@
++tc: $(TCOBJ) $(subst libutil.a,libutil-elf.a,$(LIBNETLINK)) libtc.a
++	$(QUIET_LINK)$(CC) $^ $(LDFLAGS) $(LDLIBS) $(ELF_LDLIBS) -o $@
+ 
+ libtc.a: $(TCLIB)
+ 	$(QUIET_AR)$(AR) rcs $@ $^