Initial creation of the end-user recovery tool.

user_tools/linux/recovery.sh

+#!/bin/sh
+#
+# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# This attempts to guide linux users through the process of putting a recovery
+# image onto a removeable USB drive.
+#
+# We may not need root privileges if we have the right permissions.

[Sumit, 2010/12/04 00:26:07]

Won't dd require sudo?

+#
+set -eu
+
+##############################################################################
+# Configuration goes here
+
+# Where should we do our work? Use 'WORKDIR=' to make a temporary directory,
+# but using a persistent location may let us resume interrupted downloads or
+# run again without needing to download a second time.
+WORKDIR=/tmp/tmp.crosrec
+
+# Where do we look for the config file?
+CONFIGURL='http://www.chromium.org/some/random/place.cfg'
+
+# What version is this script? It must match the 'recovery_tool_version=' value
+# in the config file that we'll download.
+MYVERSION='1.0'

[Sumit, 2010/12/04 00:26:07]

Lets decrease the version here, I will ask Scot to change this to 0.9.1

+
+
+##############################################################################
+# Some temporary filenames
+debug='debug.log'
+tmpfile='tmp.txt'
+config='config.txt'
+version='verson.txt'
+
+##############################################################################
+# Various warning messages
+
+DEBUG() {
+  echo "DEBUG: $@" >>"$debug"
+}
+
+warn() {
+  echo "$@" 1>&2
+}
+
+quit() {
+  warn "quitting..."
+  exit 1
+}
+
+fatal() {
+  warn "ERROR: $@"
+  exit 1
+}
+
+ufatal() {
+  warn "
+ERROR: $@
+
+You may need to run this program as a different user. If that doesn't help, try
+using a different computer, or ask a knowledgeable friend for help.
+
+"
+  exit 1
+}
+
+gfatal() {
+  warn "
+ERROR: $@
+
+You may need to run this program as a different user. If that doesn't help, it
+may be a networking problem or a problem with the images provided by Google.
+You might want to check to see if there is a newer version of this tool
+available, or if someone else has already reported a problem.
+
+If all else fails, you could try using a different computer, or ask a
+knowledgeable friend for help.
+
+"
+  exit 1
+}
+
+##############################################################################
+# Identify the external utilities that we MUST have available.
+#
+# I'd like to keep the set of external *NIX commands to an absolute minimum,
+# but I have to balance that against producing mysterious errors because the
+# shell can't always do everything. Let's make sure that these utilities are
+# all in our $PATH, or die with an error.
+#
+# This also sets the following global variables to select alternative utilities
+# when there is more than one equivalent tool available:
+#
+#   FETCH          = name of utility used to download files from the web
+#   FETCHNEW       = command to invoke to download fresh each time
+#   FETCHCONT      = command to invoke to download with resume if possible
+#   CHECK          = command to invoke to generate checksums on a file
+#
+require_utils() {
+  local external
+  local errors
+  local tool
+  local tmp
+
+  external='cat cut dd grep ls mkdir mount readlink sed sync umount unzip wc'
+  if [ -z "$WORKDIR" ]; then
+    external="$external mktemp"
+  fi
+  errors=
+
+  for tool in $external ; do
+    if ! type "$tool" >/dev/null 2>&1 ; then
+      warn "ERROR: can't find \"$tool\""
+      errors=yes
+    fi
+  done
+
+  # We also need to a way to fetch files from teh internets. Note that the args
+  # are different depending on which utility we find. We'll use two variants,
+  # one to fetch fresh every time and one to try again from where we left off.
+  FETCH=
+  if [ -z "$FETCH" ] && tmp=$(type curl 2>/dev/null) ; then
+    FETCH=curl
+    FETCHNEW="curl -f -s -S -o"
+    FETCHCONT="curl -f -C - -o"
+  fi
+  if [ -z "$FETCH" ] && tmp=$(type wget 2>/dev/null) ; then
+    FETCH=wget
+    FETCHNEW="wget -nv -O"
+    FETCHCONT="wget -c -O"
+  fi
+  if [ -z "$FETCH" ]; then
+    warn "ERROR: can't find \"curl\" or \"wget\""
+    errors=yes
+  fi
+
+  # Once we've fetched a file we need to compute its checksum. There are a
+  # couple of possiblities here too.
+  CHECK=
+  if [ -z "$CHECK" ] && tmp=$(type md5sum 2>/dev/null) ; then
+    CHECK="md5sum"
+  fi
+  if [ -z "$CHECK" ] && tmp=$(type sha1sum 2>/dev/null) ; then
+    CHECK="sha1sum"
+  fi
+  if [ -z "$CHECK" ]; then
+    warn "ERROR: can't find \"md5sum\" or \"sha1sum\""
+    errors=yes
+  fi
+
+  if [ -n "$errors" ]; then
+    ufatal "Some required linux utilities are missing."
+  fi
+}
+
+##############################################################################
+# Helper functions to handle the config file and image tarball.
+
+# Each paragraph in the config file should describe a new image. Let's make
+# sure it follows all the rules. This scans the config file and returns success
+# if it looks valid. As a side-effect, it lists the line numbers of the start
+# and end of each stanza in the global variables 'start_lines' and 'end_lines'
+# and saves the total number of images in the global variable 'num_images'.
+good_config() {
+  local line
+  local key
+  local val
+  local display_name
+  local file
+  local size
+  local url
+  local md5
+  local sha1
+  local skipping
+  local errors
+  local count
+  local line_num
+
+  display_name=
+  file=
+  size=
+  url=
+  md5=
+  sha1=
+  skipping=yes
+  errors=
+  count=0
+  line_num=0
+
+  # global
+  start_lines=
+  end_lines=
+
+  while read line; do
+    line_num=$(( line_num + 1 ))
+
+    # We might have some empty lines before the first stanza. Skip them.
+    if [ -n "$skipping" ] && [ -z "$line" ]; then
+      continue
+    fi
+
+    # Got something...
+    if [ -n "$line" ]; then
+      key=${line%=*}
+      val=${line#*=}
+      if [ -z "$key" ] || [ -z "$val" ] || [ "$key=$val" != "$line" ]; then
+        DEBUG "ignoring $line"
+        continue
+      fi
+
+      # right, looks good
+      if [ -n "$skipping" ]; then
+        skipping=
+        start_lines="$start_lines $line_num"
+      fi
+
+      case $key in
+        display_name)
+          if [ -n "$display_name" ]; then
+            DEBUG "duplicate $key"
+            errors=yes
+          fi
+          display_name="$val"
+          ;;
+        file)
+          if [ -n "$file" ]; then
+            DEBUG "duplicate $key"
+            errors=yes
+          fi
+          file="$val"
+          ;;
+        size)
+          if [ -n "$size" ]; then
+            DEBUG "duplicate $key"
+            errors=yes
+          fi
+          size="$val"
+          ;;
+        url)
+          url="$val"
+          ;;
+        md5)
+          md5="$val"
+          ;;
+        sha1)
+          sha1="$val"
+          ;;
+      esac
+    else
+      # Between paragraphs. Time to check what we've found so far.
+      end_lines="$end_lines $line_num"
+      count=$(( count + 1))
+
+      if [ -z "$display_name" ]; then
+        DEBUG "image $count is missing display_name"
+        errors=yes
+      fi
+      if [ -z "$file" ]; then
+        DEBUG "image $count is missing file"
+        errors=yes
+      fi
+      if [ -z "$size" ]; then
+        DEBUG "image $count is missing size"
+        errors=yes
+      fi
+      if [ -z "$url" ]; then
+        DEBUG "image $count is missing url"
+        errors=yes
+      fi
+      if [ "$CHECK" = "md5sum" ] && [ -z "$md5" ]; then
+        DEBUG "image $count is missing required md5"
+        errors=yes
+      fi
+      if [ "$CHECK" = "sha1sum" ] && [ -z "$sha1" ]; then
+        DEBUG "image $count is missing required sha1"
+        errors=yes
+      fi
+
+      # Prepare for next stanza
+      display_name=
+      file=
+      size=
+      url=
+      md5=
+      sha1=
+      skipping=yes
+    fi
+  done < "$config"
+
+  DEBUG "$count images found"
+  num_images="$count"
+
+  DEBUG "start_lines=($start_lines)"
+  DEBUG "end_lines=($end_lines)"
+
+  # return error status
+  [ "$count" != "0" ] && [ -z "$errors" ]
+}
+
+
+# Make the user pick an image to download. On success, it sets the global
+# variable 'user_choice' to the selected image number.
+choose_image() {
+  local show
+  local count
+  local line
+  local num
+
+  show=yes
+  while true; do
+    if [ -n "$show" ]; then
+      echo
+      echo "There are $num_images recovery images to choose from:"
+      echo
+      count=0
+      echo "0 - <quit>"
+      grep '^display_name=' "$config" | while read line; do
+        count=$(( count + 1 ))
+        echo "$line" | sed "s/display_name=/$count - /"
+      done
+      echo
+      show=
+    fi
+    echo -n "Please select a recovery image to download: "
+    read num
+    if [ -z "$num" ] || [ "$num" = "?" ]; then
+      show=yes
+    elif echo "$num" | grep -q '[^0-9]'; then
+      echo "Sorry, I didn't understand that."
+    else
+      if [ "$num" -lt "0" ] || [ "$num" -gt "$num_images" ]; then
+        echo "That's not one of the choices."
+      elif [ "$num" -eq 0 ]; then
+        quit
+      else
+        break;
+      fi
+    fi
+  done
+  echo
+
+  # global
+  user_choice="$num"
+}
+
+# Fetch and verify the user's chosen image. On success, it sets the global
+# variable 'image_file' to indicate the local name of the unpacked binary that
+# should be written to the USB drive.
+fetch_image() {
+  local start
+  local end
+  local line
+  local key
+  local val
+  local file
+  local size
+  local url
+  local md5
+  local sha1
+  local line_num
+  local tarball
+  local err
+  local sum
+
+  file=
+  size=
+  url=
+  md5=
+  sha1=
+  line_num="0"
+
+  # Convert image number to line numbers within config file.
+  start=$(echo $start_lines | cut -d' ' -f$1)
+  end=$(echo $end_lines | cut -d' ' -f$1)
+
+  while read line; do
+    # Skip to the start of the desired stanza
+    line_num=$(( line_num + 1 ))
+    if [ "$line_num" -lt "$start" ] || [ "$line_num" -ge "$end" ]; then
+      continue;
+    fi
+
+    # Process the stanza.
+    if [ -n "$line" ]; then
+      key=${line%=*}
+      val=${line#*=}
+      if [ -z "$key" ] || [ -z "$val" ] || [ "$key=$val" != "$line" ]; then
+        DEBUG "ignoring $line"
+        continue
+      fi
+
+      case $key in
+        # The descriptive stuff we'll just save for later.
+        file)
+          file="$val"
+          ;;
+        size)
+          size="$val"
+          ;;
+        md5)
+          md5="$val"
+          ;;
+        sha1)
+          sha1="$val"
+          ;;
+        url)
+          # Try to download each url until one works.
+          if [ -n "$url" ]; then
+            # We've already got one (it's very nice).
+            continue;
+          fi
+          warn "Downloading image tarball from $val"
+          warn
+          tarball=${val##*/}
+          if $FETCHCONT "$tarball" "$val"; then
+            # Got it.
+            url="$val"
+          else
+            # If you give curl the '-C -' option but the file you want is
+            # already complete and the server doesn't report the total size
+            # correctly, it will report an error instead of just doing nothing.
+            # We'll try to work around that.
+            err=$?
+            if [ "$FETCH" = "curl" ] && [ "$err" = "18" ]; then
+              warn "Ignoring spurious complaint"
+              url="$val"
+            fi
+          fi
+          ;;
+      esac
+    fi
+  done < "$config"
+
+  if [ -z "$url" ]; then
+    DEBUG "couldn't fetch tarball"
+    return 1
+  fi
+
+  # Verify the tarball
+  if ! ls -l "$tarball" | grep -q "$size"; then
+    DEBUG "size is wrong"
+    return 1
+  fi
+  sum=$($CHECK "$tarball" | cut -d' ' -f1)
+  DEBUG "$CHECK is $sum"
+  if [ "$CHECK" = "md5sum" ] && [ "$sum" != "$md5" ]; then
+    DEBUG "wrong $CHECK"
+    return 1
+  elif [ "$CHECK" = "sha1sum" ] && [ "$sum" != "$sha1" ]; then
+    DEBUG "wrong $CHECK"
+    return 1
+  fi
+
+  # Unpack the file
+  warn "Unpacking the tarball"
+  rm -f "$file"
+  if ! unzip "$tarball" "$file"; then
+    DEBUG "Can't unpack the tarball"
+    return 1
+  fi
+
+  # global
+  image_file="$file"
+}
+
+##############################################################################
+# Helper functions to manage USB drives.
+
+# Return a list of base device names ("sda sdb ...") for all USB drives
+get_devlist() {
+  local dev
+  local t
+  local r
+
+  for dev in $(cat /proc/partitions); do
+    [ -r "/sys/block/$dev/device/type" ] &&
+    t=$(cat "/sys/block/$dev/device/type") &&
+    [ "$t" = "0" ] &&
+    r=$(cat "/sys/block/$dev/removable") &&
+    [ "$r" = "1" ] &&
+    readlink -f "/sys/block/$dev" | grep -q -i usb &&
+    echo "$dev" || true
+  done
+}
+
+# Return descriptions for each provided base device name ("sda sdb ...")
+get_devinfo() {
+  local dev
+  local v
+  local m
+  local s
+  local ss
+
+  for dev in $1; do
+    v=$(cat "/sys/block/$dev/device/vendor") &&
+    m=$(cat "/sys/block/$dev/device/model") &&
+    s=$(cat "/sys/block/$dev/size") && ss=$(( $s * 512 / 1000000 )) &&
+    echo "/dev/$dev ${ss}MB $v $m"
+  done
+}
+
+# Enumerate and descript the specified base device names ("sda sdb ...")
+get_choices() {
+  local dev
+  local desc
+  local count
+
+  count=1
+  echo "0 - <quit>"
+  for dev in $1; do
+    desc=$(get_devinfo "$dev")
+    echo "$count - Use $desc"
+    count=$(( count + 1 ))
+  done
+}
+
+# Make the user pick a USB drive to write to. On success, it sets the global
+# variable 'user_choice' to the selected device name ("sda", "sdb", etc.)
+choose_drive() {
+  local show
+  local devlist
+  local choices
+  local num_drives
+  local msg
+  local num
+
+  show=yes
+  while true; do
+    if [ -n "$show" ]; then
+      devlist=$(get_devlist)
+      choices=$(get_choices "$devlist")
+      if [ -z "$devlist" ]; then
+        num_drives="0"
+        msg="I can't seem to find a valid USB drive."
+      else
+        num_drives=$(echo "$devlist" | wc -l)
+        if [ "$num_drives" != "1" ]; then
+          msg="I found $num_drives USB drives"
+        else
+          msg="I found $num_drives USB drive"
+        fi
+      fi
+      echo -n "
+
+$msg
+
+$choices
+
+"
+      show=
+    fi
+    echo -n "Tell me what to do (or just press Enter to scan again): "
+    read num
+    if [ -z "$num" ] || [ "$num" = "?" ]; then
+      show=yes
+    elif echo "$num" | grep -q '[^0-9]'; then
+      echo "Sorry, I didn't understand that."
+    else
+      if [ "$num" -lt "0" ] || [ "$num" -gt "$num_drives" ]; then
+        echo "That's not one of the choices."
+      elif [ "$num" -eq 0 ]; then
+        quit
+      else
+        break;
+      fi
+    fi
+  done
+
+  # global
+  user_choice=$(echo $devlist | cut -d' ' -f$num)
+}
+
+
+##############################################################################
+# Okay, do something...
+
+# Make sure we have the tools we need
+require_utils
+
+# Need a place to work. We prefer a fixed location so we can try to resume any
+# interrupted downloads.
+if [ -n "$WORKDIR" ]; then
+  if [ ! -d "$WORKDIR" ] && ! mkdir "$WORKDIR" ; then
+    warn "Using temporary directory"
+    WORKDIR=
+  fi
+fi
+if [ -z "$WORKDIR" ]; then
+  WORKDIR=$(mktemp -d)
+  # Clean up temporary directory afterwards
+  trap "cd; rm -rf ${WORKDIR}" EXIT
+fi
+
+cd "$WORKDIR"
+warn "Working in $WORKDIR/"
+rm -f "$debug"
+
+# Download the config file to see what choices we have.
+warn "Downloading config file from $CONFIGURL"
+$FETCHNEW "$tmpfile" "$CONFIGURL" || \
+  gfatal "Unable to download the config file"
+
+# Un-DOS-ify the config file and separate the version info from the images
+sed 's/\r//g' "$tmpfile" | grep '^recovery_tool' > "$version"
+sed 's/\r//g' "$tmpfile" | grep -v '^#' | grep -v '^recovery_tool' > "$config"
+# Add one empty line to the config file to terminate the last stanza
+echo >> "$config"
+
+# Make sure that the config file version matches this script version
+tmp=$(grep '^recovery_tool_version=' "$version") || \
+  gfatal "The config file doesn't contain a version string."
+filevers=${tmp#*=}
+if [ "$filevers" != "$MYVERSION" ]; then
+  tmp=$(grep '^recovery_tool_update=' "$version");
+  msg=${tmp#*=}
+  warn "This tool is version $MYVERSION." \
+    "The config file is for version $filevers."
+  fatal ${msg:-Please download a matching version of the tool and try again.}
+fi
+
+# Check the config file to be sure it's valid. As a side-effect, this sets the
+# global variable 'num_images' with the number of image stanzas read, but
+# that's independent of whether the config is valid.
+good_config || gfatal "The config file isn't valid."
+
+# Make the user pick an image to download, or exit.
+choose_image
+
+# Download the user's choice
+fetch_image "$user_choice" || \
+  gfatal "Unable to download a valid recovery image."
+
+# Make the user pick a USB drive, or exit.
+choose_drive
+
+# Be sure
+dev_desc=$(get_devinfo "$user_choice")
+echo "
+Is this the device you want to put the recovery image on?
+
+  $dev_desc
+"
+echo -n "You must enter 'YES' to continue: "
+read tmp
+if [ "$tmp" != "YES" ]; then
+  quit
+fi
+
+# Be very sure
+echo "
+
+I'm really going to erase this device. This will permanently ERASE
+whatever you may have on that drive. You won't be able to undo it.
+
+  $dev_desc
+"
+
+echo -n "If you're sure that's the device to use, enter 'DoIt' now:  "
+read tmp
+if [ "$tmp" != "DoIt" ]; then
+  quit
+fi
+echo "
+
+Installing the recovery image
+
+"
+
+# Unmount anything on that device.
+echo "unmounting..."
+for tmp in $(mount | grep ^"/dev/${user_choice}" | sed 's/[ \t].*//'); do
+  umount $tmp || ufatal "Unable to unmount $tmp."
+done
+
+# Write it.
+echo "copying... (this may take several minutes)"
+dd of=/dev/${user_choice} if="$image_file" ||
+  ufatal "Unable to write the image."
+sync
+
+echo "
+
+Done. Remove the USB drive and insert it in your Chrome OS netbook.
+
+"
+
+exit 0