Make guest account script more portable

1 files changed, 96 insertions, 69 deletions

diff --git a/debian/guest-account.sh b/debian/guest-account.sh
index ffc44eb5..675eb778 100644
--- a/debian/guest-account.sh
+++ b/debian/guest-account.sh
@@ -18,37 +18,55 @@ if [ -f /etc/default/locale ]; then
   export LANG LANGUAGE
 fi
 
+is_system_user ()
+{
+  UID_MIN=$(cat /etc/login.defs | grep UID_MIN | awk '{print $2}')
+  SYS_UID_MIN=$(cat /etc/login.defs | grep SYS_UID_MIN | awk '{print $2}')
+  SYS_UID_MAX=$(cat /etc/login.defs | grep SYS_UID_MAX | awk '{print $2}')
+
+  SYS_UID_MIN=${SYS_UID_MIN:-101}
+  SYS_UID_MAX=${SYS_UID_MAX:-$(( UID_MIN - 1 ))}
+
+  [ ${1} -ge ${SYS_UID_MIN} ] && [ ${1} -le ${SYS_UID_MAX} ]
+}
+
 add_account ()
 {
-  HOME=$(mktemp -td guest-XXXXXX)
-  USER=$(echo ${HOME} | sed 's/\(.*\)guest/guest/')
+  temp_home=$(mktemp -td guest-XXXXXX)
+  GUEST_HOME=$(echo ${temp_home} | tr '[:upper:]' '[:lower:]')
+  GUEST_USER=${GUEST_HOME#/tmp/}
+  [ ${GUEST_HOME} != ${temp_home} ] && mv ${temp_home} ${GUEST_HOME}
 
-  # if ${USER} already exists, it must be a locked system account with no existing
+  # if ${GUEST_USER} already exists, it must be a locked system account with no existing
   # home directory
-  if PWSTAT=$(passwd -S ${USER}) 2>/dev/null; then
+  if PWSTAT=$(passwd -S ${GUEST_USER}) 2>/dev/null; then
     if [ $(echo ${PWSTAT} | cut -f2 -d' ') != L ]; then
-      echo "User account ${USER} already exists and is not locked"
+      echo "User account ${GUEST_USER} already exists and is not locked"
       exit 1
     fi
-    PWENT=$(getent passwd ${USER}) || {
-      echo "getent passwd ${USER} failed"
+
+    PWENT=$(getent passwd ${GUEST_USER}) || {
+      echo "getent passwd ${GUEST_USER} failed"
       exit 1
     }
+
     GUEST_UID=$(echo ${PWENT} | cut -f3 -d:)
-    if [ ${GUEST_UID} -ge 500 ]; then
-      echo "Account ${USER} is not a system user"
+
+    if ! is_system_user ${GUEST_UID}; then
+      echo "Account ${GUEST_USER} is not a system user"
       exit 1
     fi
-    HOME=$(echo ${PWENT} | cut -f6 -d:)
-    if [ ${HOME} != / ] && [ ${HOME#/tmp} = ${HOME} ] && [ -d ${HOME} ]; then
-      echo "Home directory of ${USER} already exists"
+
+    GUEST_HOME=$(echo ${PWENT} | cut -f6 -d:)
+
+    if [ ${GUEST_HOME} != / ] && [ ${GUEST_HOME#/tmp} = ${GUEST_HOME} ] && [ -d ${GUEST_HOME} ]; then
+      echo "Home directory of ${GUEST_USER} already exists"
       exit 1
     fi
   else
     # does not exist, so create it
-    adduser --system --no-create-home --home / --gecos $(gettext "Guest") --group --shell /bin/bash ${USER} || {
-      umount ${HOME}
-      rm -rf ${HOME}
+    useradd --system --home-dir ${GUEST_HOME} --comment $(gettext "Guest") --user-group --shell /bin/bash ${GUEST_USER} || {
+      rm -rf ${GUEST_HOME}
       exit 1
     }
   fi
@@ -57,115 +75,122 @@ add_account ()
   site_gs=/etc/guest-session
 
   # create temporary home directory
-  mount -t tmpfs -o mode=700,uid=${USER} none ${HOME} || {
-    rm -rf ${HOME}
+  mount -t tmpfs -o mode=700,uid=${GUEST_USER} none ${GUEST_HOME} || {
+    rm -rf ${GUEST_HOME}
     exit 1
   }
 
-  if [ -d ${site_gs}/skel ] && [ -n $(find ${site_gs}/skel -type f) ]; then
+  if [ -d ${site_gs}/skel ] && [ "$(ls -A ${site_gs}/skel)" ]; then
     # Only perform union-mounting if BindFS is available
     if [ -x /usr/bin/bindfs ]; then
       bindfs_mount=true
 
       # Try OverlayFS first
       if modinfo -n overlay >/dev/null 2>&1; then
-        mkdir ${HOME}/upper ${HOME}/work
-        chown ${USER}:${USER} ${HOME}/upper ${HOME}/work
-        mount -t overlay -o lowerdir=${dist_gs}/skel:${site_gs}/skel,upperdir=${HOME}/upper,workdir=${HOME}/work overlay ${HOME} || {
-          umount ${HOME}
-          rm -rf ${HOME}
+        mkdir ${GUEST_HOME}/upper ${GUEST_HOME}/work
+        chown ${GUEST_USER}:${GUEST_USER} ${GUEST_HOME}/upper ${GUEST_HOME}/work
+
+        mount -t overlay -o lowerdir=${dist_gs}/skel:${site_gs}/skel,upperdir=${GUEST_HOME}/upper,workdir=${GUEST_HOME}/work overlay ${GUEST_HOME} || {
+          umount ${GUEST_HOME}
+          rm -rf ${GUEST_HOME}
           exit 1
         }
       # If OverlayFS is not available, try AuFS
       elif [ -x /sbin/mount.aufs ]; then
-        mount -t aufs -o br=${HOME}:${dist_gs}/skel:${site_gs}/skel none ${HOME} || {
-          umount ${HOME}
-          rm -rf ${HOME}
+        mount -t aufs -o br=${GUEST_HOME}:${dist_gs}/skel:${site_gs}/skel none ${GUEST_HOME} || {
+          umount ${GUEST_HOME}
+          rm -rf ${GUEST_HOME}
           exit 1
         }
       # If none of them is available, fall back to copy over
       else
-        cp -rT ${site_gs}/skel/ ${HOME}
-        cp -rT ${dist_gs}/skel/ ${HOME}
-        chown -R ${USER}:${USER} ${HOME}
+        cp -rT ${site_gs}/skel/ ${GUEST_HOME}
+        cp -rT ${dist_gs}/skel/ ${GUEST_HOME}
+        chown -R ${GUEST_USER}:${GUEST_USER} ${GUEST_HOME}
         bindfs_mount=false
       fi
 
       if ${bindfs_mount}; then
-        # Wrap ${HOME} in a BindFS mount, so that
-        # ${USER} will be seen as the owner of ${HOME}'s contents.
-        bindfs -u ${USER} -g ${USER} ${HOME} ${HOME} || {
-          umount ${HOME} # union mount
-          umount ${HOME} # tmpfs mount
-          rm -rf ${HOME}
+        # Wrap ${GUEST_HOME} in a BindFS mount, so that
+        # ${GUEST_USER} will be seen as the owner of ${GUEST_HOME}'s contents.
+        bindfs -u ${GUEST_USER} -g ${GUEST_USER} ${GUEST_HOME} ${GUEST_HOME} || {
+          umount ${GUEST_HOME} # union mount
+          umount ${GUEST_HOME} # tmpfs mount
+          rm -rf ${GUEST_HOME}
           exit 1
         }
       fi
     # If BindFS is not available, just fall back to copy over
     else
-      cp -rT ${site_gs}/skel/ ${HOME}
-      cp -rT ${dist_gs}/skel/ ${HOME}
-      chown -R ${USER}:${USER} ${HOME}
+      cp -rT ${site_gs}/skel/ ${GUEST_HOME}
+      cp -rT ${dist_gs}/skel/ ${GUEST_HOME}
+      chown -R ${GUEST_USER}:${GUEST_USER} ${GUEST_HOME}
     fi
   else
-    cp -rT /etc/skel/ ${HOME}
-    cp -rT ${dist_gs}/skel/ ${HOME}
-    chown -R ${USER}:${USER} ${HOME}
+    cp -rT /etc/skel/ ${GUEST_HOME}
+    cp -rT ${dist_gs}/skel/ ${GUEST_HOME}
+    chown -R ${GUEST_USER}:${GUEST_USER} ${GUEST_HOME}
   fi
 
-  usermod -d ${HOME} ${USER}
-
   # setup session
-  su ${USER} -c "env HOME=${HOME} site_gs=${site_gs} ${dist_gs}/setup.sh"
+  su ${GUEST_USER} -c "env HOME=${GUEST_HOME} site_gs=${site_gs} ${dist_gs}/setup.sh"
 
-  echo ${USER}
+  echo ${GUEST_USER}
 }
 
 remove_account ()
 {
   GUEST_USER=${1}
-  
+
   PWENT=$(getent passwd ${GUEST_USER}) || {
     echo "Error: invalid user ${GUEST_USER}"
     exit 1
   }
+
   GUEST_UID=$(echo ${PWENT} | cut -f3 -d:)
-  GUEST_HOME=$(echo ${PWENT} | cut -f6 -d:)
 
-  if [ ${GUEST_UID} -ge 500 ]; then
+  if ! is_system_user ${GUEST_UID}; then
     echo "Error: user ${GUEST_USER} is not a system user."
     exit 1
   fi
 
-  if [ ${GUEST_HOME} = ${GUEST_HOME#/tmp/} ]; then
-    echo "Error: home directory ${GUEST_HOME} is not in /tmp/."
-    exit 1
-  fi
+  GUEST_HOME=$(echo ${PWENT} | cut -f6 -d:)
 
   # kill all remaining processes
-  while ps h -u ${GUEST_USER} >/dev/null; do 
-    killall -9 -u ${GUEST_USER} || true
-    sleep 0.2; 
-  done
+  if [ -x /bin/loginctl ] || [ -x /usr/bin/loginctl ]; then
+    loginctl kill-user ${GUEST_USER} >/dev/null || true
+  else
+    while ps h -u ${GUEST_USER} >/dev/null
+    do
+      killall -9 -u ${GUEST_USER} || true
+      sleep 0.2;
+    done
+  fi
 
-  umount ${GUEST_HOME} || umount -l ${GUEST_HOME} || true # BindFS mount
-  umount ${GUEST_HOME} || umount -l ${GUEST_HOME} || true # union mount
-  umount ${GUEST_HOME} || umount -l ${GUEST_HOME} || true # tmpfs mount
-  rm -rf ${GUEST_HOME}
+  if [ ${GUEST_HOME} = ${GUEST_HOME#/tmp/} ]; then
+    echo "Warning: home directory ${GUEST_HOME} is not in /tmp/. It won't be removed."
+  else
+    umount ${GUEST_HOME} || umount -l ${GUEST_HOME} || true # BindFS mount
+    umount ${GUEST_HOME} || umount -l ${GUEST_HOME} || true # union mount
+    umount ${GUEST_HOME} || umount -l ${GUEST_HOME} || true # tmpfs mount
+    rm -rf ${GUEST_HOME}
+  fi
 
   # remove leftovers in /tmp
   find /tmp -mindepth 1 -maxdepth 1 -uid ${GUEST_UID} -print0 | xargs -0 rm -rf || true
 
-  # remove possible /media/guest-XXXXXX folder
-  if [ -d /media/${GUEST_USER} ]; then
-    for dir in $(find /media/${GUEST_USER} -mindepth 1 -maxdepth 1); do
-      umount ${dir} || true
-    done
+  # remove possible {/run,}/media/guest-XXXXXX folder
+  for media_dir in /run/media/${GUEST_USER} /media/${GUEST_USER}; do
+    if [ -d ${media_dir} ]; then
+      for dir in $(find ${media_dir} -mindepth 1 -maxdepth 1); do
+        umount ${dir} || true
+      done
 
-    rmdir /media/${GUEST_USER} || true
-  fi
+      rmdir ${media_dir} || true
+    fi
+  done
 
-  deluser --system ${GUEST_USER}
+  userdel ${GUEST_USER}
 }
 
 case ${1} in
@@ -177,9 +202,11 @@ case ${1} in
       echo "Usage: ${0} remove [account]"
       exit 1
     fi
+
     remove_account ${2}
     ;;
   *)
-    echo "Usage: ${0} add|remove"
+    echo "Usage: ${0} add"
+    echo "       ${0} remove [account]"
     exit 1
 esac