shill/bin/shill_login_user

#!/bin/sh

# Copyright 2018 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.

# Perform login tasks for shill.  This script is called by the "login"
# init script.

# Shill expects to find a user profile in /run/shill/user_profiles. We
# link this path to the user profile in the user's cryptohome store so
# if shill restarts while the user is logged in, shill can regain access
# to the profile.

set -e
# The login init script calls this script with the login name of the
# user whose profile is being loaded.
user="$1"
script_name="$(basename "$0")"

profile_user=chronos
profile_name="~${profile_user}/shill"
shill_state_root=/run/shill
profile_link_root="${shill_state_root}/user_profiles"
profile_link_dir="$profile_link_root/$profile_user"
log_link_dir="${shill_state_root}/log"
username_hash=""

# We should not load multiple network profiles.  If a profile link
# directory already exists, we should go no further.
if [ -e "$profile_link_dir" ]; then
  logger -t "$script_name" "User already logged in; doing nothing."
  exit 0
fi

if [ -n "${user}" ]; then
  profile_base="$(cryptohome-path system "${user}")"
  if [ ! -d "${profile_base}" ]; then
    logger -t "$script_name" \
      "User cryptohome dir ${profile_base} does not exist"
    exit 1
  fi
  username_hash="$(basename "${profile_base}")"
else
  # If no user is given, create a temporary profile directory which will
  # be erased on logout.
  profile_base="${shill_state_root}/guest_user_profile"
  rm -rf "${profile_base}"
fi

profile_dir="${profile_base}/shill"
profile="${profile_dir}/shill.profile"
log_dir="${profile_base}/shill_logs"

if [ ! -d "${profile_dir}" ]; then
  if ! mkdir -p --mode=700 "${profile_dir}"; then
    logger -t "$script_name" \
      "Failed to create shill user profile directory ${profile_dir}"
    exit 1
  fi
fi

# We need to ensure this dir (and files within it) are owned by shill:shill,
# regardless of whether we are creating it on this login or it already existed
# before now. By default, the 'chown -R' command does not follow symlinks, so
# there is no way shill can put a symlink in this dir as means of tricking the
# system into making other files owned by 'shill'. Also, this being the "shill
# user profile directory", it is fine to give shill ownership of all of its
# contents. Although 'chown -R' doesn't follow symlinks, it does affect bind
# mounts, so this code is only safe as long as shill runs without
# CAP_SYS_ADMIN. Ideally we should have some kind of test to make sure shill
# capabilities are never widened to include CAP_SYS_ADMIN -- filed
# crbug.com/869170 to track this issue in the general sense for CrOS system
# services.
if ! chown -R shill:shill "${profile_dir}"; then
  logger -t "$script_name" \
    "Failed to chown shill user profile directory ${profile_dir}"
  exit 1
fi

if ! mkdir -p --mode 0700 "$profile_link_root"; then
  logger -t "$script_name" \
    "Unable to create shill user profile link directory"
else
  if ! chown shill:shill "$profile_link_root"; then
    logger -t "$script_name" "Unable to chown shill user profile link directory"
  fi
fi

ln -s "${profile_dir}" "$profile_link_dir" ||
  logger -t "$script_name" \
    "Failed to create shill user cryptohome link $profile_link_dir"

if ! mkdir -p --mode 0700 "$log_dir"; then
  logger -t "$script_name" \
    "Unable to create shill log directory"
else
  if ! chown shill:shill "$log_dir"; then
    logger -t "$script_name" "Unable to chown shill log directory"
  fi
fi

if [ ! -h "$log_link_dir" ]; then
  ln -s "$log_dir" "$log_link_dir" ||
    logger -t "$script_name" \
      "Failed to create shill logs link $log_link_dir"
fi

if [ ! -f "$profile" ]; then
  # If profile does not exist, ask shill to create one.
  dbus-send --system --dest=org.chromium.flimflam --print-reply / \
    org.chromium.flimflam.Manager.CreateProfile string:$profile_name ||
      logger -t "$script_name" "Failed to create $profile_name profile"
fi

# Push user's network profile
dbus-send --system --dest=org.chromium.flimflam --print-reply / \
  org.chromium.flimflam.Manager.InsertUserProfile \
      string:"${profile_name}" string:"${username_hash}" ||
    logger -t "$script_name" "Failed to push $profile_name profile"