New aport ldpath

Utility to add or remove paths from musl dynamic linker config file

main/ldpath/APKBUILD

@@ -0,0 +1,23 @@
+pkgname=ldpath
+pkgver=0.1
+pkgrel=0
+pkgdesc="Utility to add or remove paths from musl dynamic linker config file"
+url="https://postmarketos.org/"
+arch="noarch"
+license="MIT"
+source="
+	ldpath.sh
+	ldpath_test.sh
+	"
+
+check() {
+	sh ldpath_test.sh
+}
+
+package() {
+	install -Dm755 "$srcdir/ldpath.sh" \
+		"$pkgdir/usr/bin/ldpath"
+}
+
+sha512sums="0bf8a3bcbb314f54653921d1757b35dc582997a4c058033a390c8b8a520f44541ba1791775ef5a63706da1b8cb86018bb9c7c7effce1c4ea65a2d33896e583ff  ldpath.sh
+e9ac37e88bc8fb6def9d550a58da0cc8c62dc14c49d6119e95560ff7d4c36eeb6dbbbce8006de6a170f6833b3ca54c80a2f173f67fefad4bf0927dc0a3d692b7  ldpath_test.sh"

main/ldpath/ldpath.sh

@@ -0,0 +1,168 @@
+#!/bin/sh
+#
+# Add or remove paths from musl dynamic linker
+# path file (/etc/ld-musl-$ARCH.path)
+#
+# usage example:
+# $ ldpath.sh add /usr/lib/libdrm-grate
+
+default_ld_paths() {
+	echo "/lib:/usr/local/lib:/usr/lib"
+}
+
+###############################################
+# Processor arch in the convention used  by the
+# musl dynamic linker.
+#   See musl source code: ldso/dynlink.c
+# Arguments:
+#   kernel machine hardware name (uname -m)
+# Returns:
+#   musl ldso processor arch
+###############################################
+kernel_arch_to_ldso_arch() {
+	local karch=$1
+	local ld_arch=""
+	case "$karch" in
+		armv7l)
+			ld_arch=armhf
+			;;
+		*)
+			ld_arch="$karch"
+			;;
+	esac
+	echo "$ld_arch"
+}
+
+default_ld_musl_file() {
+	local ld_arch
+	ld_arch=$(kernel_arch_to_ldso_arch "$(uname -m)")
+	echo "/etc/ld-musl-${ld_arch}.path"
+}
+
+###############################################
+# Prepend a path to dynamic linker path file
+# Arguments:
+#   Shared library directory
+#   ld musl path file
+###############################################
+add_path() {
+	local ld_library_path=$1
+	local ld_musl_file=$2
+
+	# Don't allow duplicates
+	if [ -f "$ld_musl_file" ]; then
+		if grep -q "$ld_library_path" "$ld_musl_file"; then
+			return 0
+		fi
+	fi
+
+	if [ -f "$ld_musl_file" ]; then
+		echo "${ld_library_path}:$(cat "$ld_musl_file")" > \
+			"$ld_musl_file"
+	else
+		echo "${ld_library_path}:$(default_ld_paths)" > "$ld_musl_file"
+	fi
+}
+
+###############################################
+# Remove a path from dynamic linker path file
+# Arguments:
+#   Shared library directory
+#   ld musl path file
+###############################################
+remove_path() {
+	local ld_library_path=$1
+	local ld_musl_file=$2
+	local conf
+
+	if [ ! -f "$ld_musl_file" ]; then
+		return 0
+	fi
+
+	# Don't remove default paths
+	if default_ld_paths | grep -q "$ld_library_path"; then
+		return 0
+	fi
+
+	conf=$(awk -v ld_path="$ld_library_path" '{n=split($0, array, ":")} END {
+		for (i in array) {
+			if (array[i]!=ld_path) {
+				printf array[i]
+				if (i<n)
+					printf ":"
+			}
+		}
+	}' < "$ld_musl_file")
+	echo "$conf" > "$ld_musl_file"
+}
+
+print_usage() {
+	local ld_arch
+	ld_arch=$(kernel_arch_to_ldso_arch "$(uname -m)")
+	echo "usage: $(basename "$1") [-h] [-f FILE] {add,remove} LD_LIBRARY_PATH"
+	echo ""
+	echo "Add or remove LD_LIBRARY_PATH in $(default_ld_musl_file)"
+	echo ""
+	echo "optional arguments:"
+	echo "  -h, --help            show this help message and exit"
+	echo "  -f, --file            override ld musl path file"
+}
+
+parse_args() {
+	local have_file_arg=""
+	while [ "${1:-}" != "" ]; do
+		case $1 in
+		add|remove)
+			ldpath_func="$1"
+			ldpath_arg="$2"
+			shift
+			shift
+			;;
+		-f|--file)
+			have_file_arg="1"
+			ld_musl_file="$2"
+			shift
+			shift
+			;;
+		-h|--help)
+			shift
+			return 0
+			;;
+		*)
+			echo "Invalid argument: $1"
+			shift
+			return 0
+			;;
+		esac
+	done
+
+	if [ -z "$ldpath_func" ] || [ -z "$ldpath_arg" ]; then
+		return 0
+	fi
+
+	if [ "$have_file_arg" = "1" ] &&
+		[ -z "$ld_musl_file" ]; then
+		return 0
+	fi
+
+	return 1
+}
+
+main() {
+	if [ -z "$ld_musl_file" ]; then
+		ld_musl_file=$(default_ld_musl_file)
+	fi
+
+	if [ "$ldpath_func" = "add" ]; then
+		add_path "$ldpath_arg" "$ld_musl_file"
+	elif [ "$ldpath_func" = "remove" ]; then
+		remove_path "$ldpath_arg" "$ld_musl_file"
+	fi
+}
+
+if parse_args "$@"; then
+	print_usage "$0"
+	return 1
+fi
+
+main "$0"

main/ldpath/ldpath_test.sh

@@ -0,0 +1,73 @@
+#!/bin/sh
+
+testdir=$(mktemp -d)
+ld_musl_file="${testdir}/ld-musl-test.path"
+
+lib_path="/usr/lib/foo"
+lib_path2="/usr/lib/bar"
+
+# Create ldso config file and add a path to it.
+sh ldpath.sh -f "$ld_musl_file" add "$lib_path"
+
+if ! grep -q "$lib_path" "$ld_musl_file"; then
+	echo "ERROR: Did not find $lib_path in newly created config file."
+	exit 1
+fi
+
+# Add another path to config file.
+sh ldpath.sh -f "$ld_musl_file" add "$lib_path2"
+if ! grep -q "$lib_path2" "$ld_musl_file"; then
+	echo "ERROR: Did not find $lib_path2 in config file."
+	exit 1
+fi
+
+# Check that first path is still present
+if ! grep -q "$lib_path" "$ld_musl_file"; then
+	echo "ERROR: Did not find $lib_path in config file."
+	exit 1
+fi
+
+# Remove the first path
+sh ldpath.sh -f "$ld_musl_file" remove "$lib_path"
+if grep -q "$lib_path" "$ld_musl_file"; then
+	echo "ERROR: $lib_path was not removed from config file."
+	exit 1
+fi
+
+# Check that second path is still present
+if ! grep -q "$lib_path2" "$ld_musl_file"; then
+	echo "ERROR: $lib_path2 should not have been removed."
+	exit 1
+fi
+
+# Remove the second path
+sh ldpath.sh -f "$ld_musl_file" remove "$lib_path2"
+if grep -q "$lib_path2" "$ld_musl_file"; then
+	echo "ERROR: $lib_path2 was not removed from config file."
+	exit 1
+fi
+
+# Don't allow removal of default paths
+_default_paths="/lib /usr/local/lib /usr/lib"
+for _path in $_default_paths
+do
+	sh ldpath.sh -f "$ld_musl_file" remove "$_path"
+	if ! grep -q "$_path" "$ld_musl_file"; then
+		echo "ERROR: Default path $_path should not have been removed."
+		exit 1
+	fi
+done
+
+# Don't allow duplicates
+sh ldpath.sh -f "$ld_musl_file" add "$lib_path"
+sh ldpath.sh -f "$ld_musl_file" add "$lib_path"
+_count=$(grep -o "$lib_path" "$ld_musl_file" | wc -l)
+if [ "$_count" -ne 1 ]; then
+	echo "ERROR: Multiple entries of $lib_path."
+	exit 1
+fi
+
+# Cleanup
+rm -r "$testdir"
+
+exit 0