OpenWrt – Rev 1

?pathlinks?

Blame – Last modification – View Log – Download

#!/usr/bin/env bash
#
#   Script to install host system binaries along with required libraries.
#
#   Copyright (C) 2012-2017 Jo-Philipp Wich <jo@mein.io>
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

DIR="$1"; shift

_cp() {
        cp ${VERBOSE:+-v} -L "$1" "$2" || {
                echo "cp($1 $2) failed" >&2
                exit 1
        }
}

_mv() {
        mv ${VERBOSE:+-v} "$1" "$2" || {
                echo "mv($1 $2) failed" >&2
                exit 1
        }
}

_md() {
        mkdir ${VERBOSE:+-v} -p "$1" || {
                echo "mkdir($1) failed" >&2
                exit 2
        }
}

_ln() {
        ln ${VERBOSE:+-v} -sf "$1" "$2" || {
                echo "ln($1 $2) failed" >&2
                exit 3
        }
}

_relpath() {
        local base="$(readlink -f "$1")"
        local dest="$(readlink -f "$2")"
        local up

        [ -d "$base" ] || base="${base%/*}"
        [ -d "$dest" ] || dest="${dest%/*}"

        while true; do
                case "$base"
                        in "$dest"/*)
                                echo "$up/${base#$dest/}"
                                break
                        ;;
                        *)
                                dest="${dest%/*}"
                                up="${up:+$up/}.."
                        ;;
                esac
        done
}

_runas_so() {
        cat <<-EOT | ${CC:-gcc} -x c -fPIC -shared -o "$1" -
                #include <unistd.h>
                #include <stdio.h>
                #include <stdlib.h>

                int mangle_arg0(int argc, char **argv, char **env) {
                        char *arg0 = getenv("RUNAS_ARG0");

                        if (arg0) {
                                argv[0] = arg0;
                                unsetenv("RUNAS_ARG0");
                        }

                        return 0;
                }

                #ifdef __APPLE__
                __attribute__((section("__DATA,__mod_init_func")))
                #else
                __attribute__((section(".init_array")))
                #endif
                static void *mangle_arg0_constructor = &mangle_arg0;
        EOT

        [ -x "$1" ] || {
                echo "compiling preload library failed" >&2
                exit 5
        }
}

_patch_ldso() {
        _cp "$1" "$1.patched"
        sed -i -e 's,/\(usr\|lib\|etc\)/,/###/,g' "$1.patched"

        if "$1.patched" 2>&1 | grep -q -- --library-path; then
                _mv "$1.patched" "$1"
        else
                echo "binary patched ${1##*/} not executable, using original" >&2
                rm -f "$1.patched"
        fi
}

_patch_glibc() {
        _cp "$1" "$1.patched"
        sed -i -e 's,/usr/\(\(lib\|share\)/locale\),/###/\1,g' "$1.patched"

        if "$1.patched" 2>&1 | grep -q -- GNU; then
                _mv "$1.patched" "$1"
        else
                echo "binary patched ${1##*/} not executable, using original" >&2
                rm -f "$1.patched"
        fi
}

for LDD in ${PATH//://ldd }/ldd; do
        "$LDD" --version >/dev/null 2>/dev/null && break
        LDD=""
done

[ -n "$LDD" -a -x "$LDD" ] || LDD=

for BIN in "$@"; do
        [ -n "$BIN" -a -n "$DIR" ] || {
                echo "Usage: $0 <destdir> <executable> ..." >&2
                exit 1
        }

        [ ! -d "$DIR/lib" ] && {
                _md "$DIR/lib"
                _md "$DIR/usr"
                _ln "../lib" "$DIR/usr/lib"
        }

        [ ! -x "$DIR/lib/runas.so" ] && {
                _runas_so "$DIR/lib/runas.so"
        }

        LDSO=""

        [ -n "$LDD" ] && [ -x "$BIN" ] && file "$BIN" | grep -sqE "ELF.*(executable|interpreter)" && {
                for token in $("$LDD" "$BIN" 2>/dev/null); do
                        case "$token" in */*.so*)
                                dest="$DIR/lib/${token##*/}"
                                ddir="${dest%/*}"

                                case "$token" in
                                        */ld-*.so*) LDSO="${token##*/}" ;;
                                esac

                                [ -f "$token" -a ! -f "$dest" ] && {
                                        _md "$ddir"
                                        _cp "$token" "$dest"
                                        case "$token" in
                                                */ld-*.so*) _patch_ldso "$dest" ;;
                                                */libc.so.6) _patch_glibc "$dest" ;;
                                        esac
                                }
                        ;; esac
                done
        }

        # is a dynamically linked executable
        if [ -n "$LDSO" ]; then
                echo "Bundling ${BIN##*/}"

                RUNDIR="$(readlink -f "$BIN")"; RUNDIR="${RUNDIR%/*}"
                RUN="${LDSO#ld-}"; RUN="run-${RUN%%.so*}.sh"
                REL="$(_relpath "$DIR/lib" "$BIN")"

                _mv "$BIN" "$RUNDIR/.${BIN##*/}.bin"

                cat <<-EOF > "$BIN"
                        #!/usr/bin/env bash
                        dir="\$(dirname "\$0")"
                        export RUNAS_ARG0="\$0"
                        export LD_PRELOAD="\$dir/${REL:+$REL/}runas.so"
                        exec "\$dir/${REL:+$REL/}$LDSO" --library-path "\$dir/${REL:+$REL/}" "\$dir/.${BIN##*/}.bin" "\$@"
                EOF

                chmod ${VERBOSE:+-v} 0755 "$BIN"
        fi
done