scripts/bundle-libraries.sh

   1 #!/usr/bin/env bash
   2 #
   3 #   Script to install host system binaries along with required libraries.
   4 #
   5 #   Copyright (C) 2012-2017 Jo-Philipp Wich <jo@mein.io>
   6 #
   7 #   This program is free software; you can redistribute it and/or modify
   8 #   it under the terms of the GNU General Public License as published by
   9 #   the Free Software Foundation; either version 2 of the License, or
  10 #   (at your option) any later version.
  11 #
  12 #   This program is distributed in the hope that it will be useful,
  13 #   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 #   GNU General Public License for more details.
  16 #
  17 #   You should have received a copy of the GNU General Public License
  18 #   along with this program; if not, write to the Free Software
  19 #   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20
  21 DIR="$1"; shift
  22
  23 _cp() {
  24         cp ${VERBOSE:+-v} -L "$1" "$2" || {
  25                 echo "cp($1 $2) failed" >&2
  26                 exit 1
  27         }
  28 }
  29
  30 _mv() {
  31         mv ${VERBOSE:+-v} "$1" "$2" || {
  32                 echo "mv($1 $2) failed" >&2
  33                 exit 1
  34         }
  35 }
  36
  37 _md() {
  38         mkdir ${VERBOSE:+-v} -p "$1" || {
  39                 echo "mkdir($1) failed" >&2
  40                 exit 2
  41         }
  42 }
  43
  44 _ln() {
  45         ln ${VERBOSE:+-v} -sf "$1" "$2" || {
  46                 echo "ln($1 $2) failed" >&2
  47                 exit 3
  48         }
  49 }
  50
  51 _relpath() {
  52         local base="$(readlink -f "$1")"
  53         local dest="$(readlink -f "$2")"
  54         local up
  55
  56         [ -d "$base" ] || base="${base%/*}"
  57         [ -d "$dest" ] || dest="${dest%/*}"
  58
  59         while true; do
  60                 case "$base"
  61                         in "$dest"/*)
  62                                 echo "$up/${base#$dest/}"
  63                                 break
  64                         ;;
  65                         *)
  66                                 dest="${dest%/*}"
  67                                 up="${up:+$up/}.."
  68                         ;;
  69                 esac
  70         done
  71 }
  72
  73 _runas_so() {
  74         cat <<-EOT | ${CC:-gcc} -x c -fPIC -shared -o "$1" -
  75                 #include <unistd.h>
  76                 #include <stdio.h>
  77                 #include <stdlib.h>
  78
  79                 int mangle_arg0(int argc, char **argv, char **env) {
  80                         char *arg0 = getenv("RUNAS_ARG0");
  81
  82                         if (arg0)
  83                                 argv[0] = arg0;
  84
  85                         return 0;
  86                 }
  87
  88                 __attribute__((section(".init_array")))
  89                 static void *mangle_arg0_constructor = &mangle_arg0;
  90         EOT
  91
  92         [ -x "$1" ] || {
  93                 echo "compiling preload library failed" >&2
  94                 exit 5
  95         }
  96 }
  97
  98 for LDD in ${PATH//://ldd }/ldd; do
  99         "$LDD" --version >/dev/null 2>/dev/null && break
 100         LDD=""
 101 done
 102
 103 [ -n "$LDD" -a -x "$LDD" ] || LDD=
 104
 105 for BIN in "$@"; do
 106         [ -n "$BIN" -a -n "$DIR" ] || {
 107                 echo "Usage: $0 <destdir> <executable> ..." >&2
 108                 exit 1
 109         }
 110
 111         [ ! -d "$DIR/lib" ] && {
 112                 _md "$DIR/lib"
 113                 _md "$DIR/usr"
 114                 _ln "../lib" "$DIR/usr/lib"
 115         }
 116
 117         [ ! -x "$DIR/lib/runas.so" ] && {
 118                 _runas_so "$DIR/lib/runas.so"
 119         }
 120
 121         LDSO=""
 122
 123         [ -n "$LDD" ] && [ -x "$BIN" ] && file "$BIN" | grep -sqE "ELF.*(executable|interpreter)" && {
 124                 for token in $("$LDD" "$BIN" 2>/dev/null); do
 125                         case "$token" in */*.so*)
 126                                 case "$token" in
 127                                         *ld-*.so*) LDSO="${token##*/}" ;;
 128                                 esac
 129
 130                                 dest="$DIR/lib/${token##*/}"
 131                                 ddir="${dest%/*}"
 132
 133                                 [ -f "$token" -a ! -f "$dest" ] && {
 134                                         _md "$ddir"
 135                                         _cp "$token" "$dest"
 136                                 }
 137                         ;; esac
 138                 done
 139         }
 140
 141         # is a dynamically linked executable
 142         if [ -n "$LDSO" ]; then
 143                 echo "Bundling ${BIN##*/}"
 144
 145                 RUNDIR="$(readlink -f "$BIN")"; RUNDIR="${RUNDIR%/*}"
 146                 RUN="${LDSO#ld-}"; RUN="run-${RUN%%.so*}.sh"
 147                 REL="$(_relpath "$DIR/lib" "$BIN")"
 148
 149                 _mv "$BIN" "$RUNDIR/.${BIN##*/}.bin"
 150
 151                 cat <<-EOF > "$BIN"
 152                         #!/usr/bin/env bash
 153                         dir="\$(dirname "\$0")"
 154                         export RUNAS_ARG0="\$0"
 155                         export LD_PRELOAD="\$dir/${REL:+$REL/}runas.so"
 156                         exec "\$dir/${REL:+$REL/}$LDSO" --library-path "\$dir/${REL:+$REL/}" "\$dir/.${BIN##*/}.bin" "\$@"
 157                 EOF
 158
 159                 chmod ${VERBOSE:+-v} 0755 "$BIN"
 160         fi
 161 done