Merge branch 'config-libdir' into next

Andrea Claudi  says:

====================

This series add support for the libdir parameter in iproute2 configure
script. The idea is to make use of the fact that packaging systems may
assume that 'configure' comes from autotools allowing a syntax similar
to the autotools one, and using it to tell iproute2 where the distro
expects to find its lib files.

Patches 1-2 fix a parsing issue on current configure options, that may
trigger an endless loop when no value is provided with some options;

Patch 3 fixes a parsing issue bailing out when more than one value is
provided for a single option;

Patch 4 simplifies options parsing, moving semantic checks out of the
while loop processing options;

Patch 5 introduces support for the --opt=value style on current options,
for uniformity;

Patch 6 adds the --prefix option, that may be used by some packaging
systems when calling the configure script;

Patch 7 finally adds the --libdir option, and also drops the static
LIBDIR var from the Makefile.

Changelog:
----------
v4 -> v5
  - bail out when multiple values are provided with a single option
  - simplify option parsing and reduce code duplication, as suggested
    by Phil Sutter
  - remove a nasty eval on libdir option processing

v3 -> v4
  - fix parsing issue on '--include_dir' and '--libbpf_dir'
  - split '--opt value' and '--opt=value' use cases, avoid code
    duplication moving semantic checks on value to dedicated functions

v2 -> v3
  - fix parsing error on prefix and libdir options.

v1 -> v2
  - consolidate '--opt value' and '--opt=value' use cases, as suggested
    by David Ahern.
  - added patch 2 to manage the --prefix option, used by the Debian
    packaging system, as reported by Luca Boccassi, and use it when
    setting lib directory.

====================

Signed-off-by: David Ahern <dsahern@kernel.org>

Makefile

@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 # Top level Makefile for iproute2
 
+-include config.mk
+
 ifeq ("$(origin V)", "command line")
 VERBOSE = $(V)
 endif
@@ -13,7 +15,6 @@ MAKEFLAGS += --no-print-directory
 endif
 
 PREFIX?=/usr
-LIBDIR?=$(PREFIX)/lib
 SBINDIR?=/sbin
 CONFDIR?=/etc/iproute2
 NETNS_RUN_DIR?=/var/run/netns
@@ -69,7 +70,7 @@ SUBDIRS=lib ip tc bridge misc netem genl tipc devlink rdma dcb man vdpa
 LIBNETLINK=../lib/libutil.a ../lib/libnetlink.a
 LDLIBS += $(LIBNETLINK)
 
-all: config
+all: config.mk
 	@set -e; \
 	for i in $(SUBDIRS); \
 	do echo; echo $$i; $(MAKE) -C $$i; done
@@ -89,7 +90,7 @@ help:
 	@echo "Make Arguments:"
 	@echo " V=[0|1]             - set build verbosity level"
 
-config:
+config.mk:
 	@if [ ! -f config.mk -o configure -nt config.mk ]; then \
 		sh configure $(KERNEL_INCLUDE); \
 	fi

configure

@@ -3,6 +3,8 @@
 # This is not an autoconf generated configure
 
 INCLUDE="$PWD/include"
+PREFIX="/usr"
+LIBDIR="\${prefix}/lib"
 
 # Output file which is input to Makefile
 CONFIG=config.mk
@@ -148,6 +150,15 @@ EOF
 	rm -f $TMPDIR/ipttest.c $TMPDIR/ipttest
 }
 
+check_lib_dir()
+{
+	LIBDIR=$(echo $LIBDIR | sed "s|\${prefix}|$PREFIX|")
+
+	echo -n "lib directory: "
+	echo "$LIBDIR"
+	echo "LIBDIR:=$LIBDIR" >> $CONFIG
+}
+
 check_ipt()
 {
 	if ! grep TC_CONFIG_XT $CONFIG > /dev/null; then
@@ -485,12 +496,14 @@ usage()
 {
 	cat <<EOF
 Usage: $0 [OPTIONS]
-	--include_dir		Path to iproute2 include dir
-	--libbpf_dir		Path to libbpf DESTDIR
-	--libbpf_force		Enable/disable libbpf by force. Available options:
-				  on: require link against libbpf, quit config if no libbpf support
-				  off: disable libbpf probing
-	-h | --help		Show this usage info
+	--include_dir <dir>		Path to iproute2 include dir
+	--libdir <dir>			Path to iproute2 lib dir
+	--libbpf_dir <dir>		Path to libbpf DESTDIR
+	--libbpf_force <on|off>		Enable/disable libbpf by force. Available options:
+					  on: require link against libbpf, quit config if no libbpf support
+					  off: disable libbpf probing
+	--prefix <dir>			Path prefix of the lib files to install
+	-h | --help			Show this usage info
 EOF
 	exit $1
 }
@@ -499,30 +512,56 @@ EOF
 if [ $# -eq 1 ] && [ "$(echo $1 | cut -c 1)" != '-' ]; then
 	INCLUDE="$1"
 else
-	while true; do
+	while [ "$#" -gt 0 ]; do
 		case "$1" in
 			--include_dir)
-				INCLUDE=$2
-				shift 2 ;;
+				shift
+				INCLUDE="$1" ;;
+			--include_dir=*)
+				INCLUDE="${1#*=}" ;;
+			--libdir)
+				shift
+				LIBDIR="$1" ;;
+			--libdir=*)
+				LIBDIR="${1#*=}" ;;
 			--libbpf_dir)
-				LIBBPF_DIR="$2"
-				shift 2 ;;
+				shift
+				LIBBPF_DIR="$1" ;;
+			--libbpf_dir=*)
+				LIBBPF_DIR="${1#*=}" ;;
 			--libbpf_force)
-				if [ "$2" != 'on' ] && [ "$2" != 'off' ]; then
-					usage 1
-				fi
-				LIBBPF_FORCE=$2
-				shift 2 ;;
+				shift
+				LIBBPF_FORCE="$1" ;;
+			--libbpf_force=*)
+				LIBBPF_FORCE="${1#*=}" ;;
+			--prefix)
+				shift
+				PREFIX="$1" ;;
+			--prefix=*)
+				PREFIX="${1#*=}" ;;
 			-h | --help)
 				usage 0 ;;
-			"")
-				break ;;
+			--*)
+				;;
 			*)
-				shift 1 ;;
+				usage 1 ;;
 		esac
+		[ "$#" -gt 0 ] && shift
 	done
 fi
 
+[ -d "$INCLUDE" ] || usage 1
+if [ "${LIBBPF_DIR-unused}" != "unused" ]; then
+	[ -d "$LIBBPF_DIR" ] || usage 1
+fi
+if [ "${LIBBPF_FORCE-unused}" != "unused" ]; then
+	if [ "$LIBBPF_FORCE" != 'on' ] && [ "$LIBBPF_FORCE" != 'off' ]; then
+		usage 1
+	fi
+fi
+[ -z "$PREFIX" ] && usage 1
+[ -z "$LIBDIR" ] && usage 1
+
 echo "# Generated config based on" $INCLUDE >$CONFIG
 quiet_config >> $CONFIG
 
@@ -546,6 +585,7 @@ if ! grep -q TC_CONFIG_NO_XT $CONFIG; then
 fi
 
 echo
+check_lib_dir
 if ! grep -q TC_CONFIG_NO_XT $CONFIG; then
 	echo -n "iptables modules directory: "
 	check_ipt_lib_dir