#!/bin/bash
#
# Copyright 2014 Red Hat, Inc.
#
# NAME
#     lab-smbmultiuser - setup/grading script for RH254/RH299 SMB practice
#
# SYNOPSIS
#     lab-smbmultiuser {setup|grade}
#
#     The setup function works on both desktopX and serverX.
#     The grade function only works on desktopX.example.com.
#
# DESCRIPTION
#     This script is the setup/grading script for a RH254 SMB
#     multiuser practice exercise.
#
# CHANGELOG
#   * Mon Jun 16 2014 George Hacker <ghacker@redhat.com>
#   - fixed a bug that caused check_cifs_multiuser_mount to always fail
#   * Tue Jun  3 2014 Rudy Kastl <rkastl@redhat.com>
#   - original code

# Initialize and set some variables
MYHOST=""
CMD=""
RUN_AS_ROOT=true

SERV_PKG="samba samba-client"
CLNT_PKG=""
SERV_ERR="Error running script. Did you reset the server before running this script? \
Contact your instructor if you continue to see this message."
CLNT_ERR="Error running script. Did you reset the desktop before running this script? \
Contact your instructor if you continue to see this message."

# Source library of functions
source /usr/local/bin/labtool.shlib
trap on_exit EXIT
LOG_TAG=$(basename $0)

# Additional functions for this shell script
function srv_exit {
  # call debug with msg and exit with code
  DEBUG=true
  debug "$1"
  exit $2
}

function install_pkgs {
  # install the package that provides the service
  echo "Installing packages ..."
  yum -y install $@ &> /dev/null || \
    srv_exit "yum failed: $?" 150
}

function setup_server_samba {
  echo "Setting up samba ..."
  groupadd -r marketing &>/dev/null
  mkdir -p /smbshare &>/dev/null
  chgrp marketing /smbshare &>/dev/null
  chmod 2775 /smbshare &>/dev/null
  semanage fcontext -a -t samba_share_t '/smbshare(/.*)?' &>/dev/null
  restorecon -vvFR /smbshare &>/dev/null
  
  echo "Adding Samba-only users brian and rob"
  useradd -s /sbin/nologin -G marketing brian &>/dev/null
  ((echo "redhat"; echo "redhat") | smbpasswd -s -a brian) &>/dev/null
  useradd -s /sbin/nologin rob &>/dev/null
  ((echo "redhat"; echo "redhat") | smbpasswd -s -a rob) &>/dev/null

  echo "Configuring Samba"
  (echo "[smbshare]" >> /etc/samba/smb.conf) &>/dev/null
  (echo "path = /smbshare" >> /etc/samba/smb.conf) &>/dev/null
  (echo "write list = @marketing" >> /etc/samba/smb.conf) &>/dev/null

  echo "Starting and enabling Samba ..."
  systemctl enable smb nmb &> /dev/null || srv_exit "systemctl enable failed: $?" 151
  systemctl start smb nmb &> /dev/null || srv_exit "systemctl start failed: $?" 152

  echo "Setting up firewall ..."
  firewall-cmd --permanent --add-service=samba &>/dev/null
  firewall-cmd --reload &>/dev/null
}

function setup_desktop_users {
  echo "Setting up users brian and rob ..."
  useradd brian &>/dev/null
  (echo redhat | passwd --stdin brian) &>/dev/null
  useradd rob &>/dev/null
  (echo redhat | passwd --stdin rob) &>/dev/null
}

# grading scripts desktop
function check_cifs_utils_installed {
  echo -n "Checking for cifs-utils rpm package... "
  if rpm -q cifs-utils &>/dev/null
  then
    print_PASS
  else
    print_FAIL
    echo "The rpm package cifs-utils is not installed."
    return 1
  fi
}

function check_cifs_multiuser_mountpoint {
  echo -n "Checking for /mnt/multiuser mountpoint... "
  if [ -d /mnt/multiuser ]
  then
    print_PASS
  else
    print_FAIL
    echo "The directory /mnt/multiuser does not exist."
    return 1
  fi
}

function check_cifs_multiuser_fstab {
  echo -n "Checking for multiuser fstab entry... "
  if ! grep '//server.*/smbshare.*/mnt/multiuser.*cifs.*' /etc/fstab &>/dev/null
  then
    print_FAIL
    echo "There is no fstab entry for the smb share //serverX/smbshare."
    return 1
  elif ! (grep '//server.*/smbshare.*/mnt/multiuser.*cifs.*' /etc/fstab |grep credentials) &>/dev/null
  then
    print_FAIL
    echo "No credentials directive present in the fstab entry for //serverX/smbshare."
    return 1
  elif ! (grep '//server.*/smbshare.*/mnt/multiuser.*cifs.*' /etc/fstab |grep multiuser) &>/dev/null
  then
    print_FAIL
    echo "The fstab entry for //serverX/smbshare is missing the multiuser mount option."
    return 1
  else
    print_PASS
  fi
}

function check_cifs_multiuser_mount {
  echo -n "Checking for multiuser mount... "
  if ! (mount | grep "//server${X}/smbshare.*/mnt/multiuser.*cifs.*") &>/dev/null
  then
    print_FAIL
    echo "The //serverX/smbshare share is not mounted on /mnt/multiuser"
    return 1
  else
    print_PASS
  fi
}

#function check_cifs_user_perm {
#  echo -n "Checking for user permissions on /mnt/multiuser... "
#  rm -f /mnt/multiuser/grade-brian.txt &>/dev/null
#  if ! (su - brian -c 'echo 'grade' >/mnt/multiuser/grade-brian.txt') &>/dev/null
#  then
#    print_FAIL
#    echo "User brian is not allowed to write to /mnt/multiuser. Are the permission correct #for /smbshare on server? Did you add the correct credentials with cifscreds?"
#    return 1
#  elif ! (su - rob -c 'grep grade /mnt/multiuser/grade-brian.txt') &>/dev/null
#  then
#    print_FAIL
#    echo "User rob is not allowed to read a file created by user brian. Did you set the SGID #bit on /smbshare on serverX? Did you add the correct credentials with cifscreds?"
#    return 1
#  else
#    print_PASS
#  fi
#}



function print_usage {
echo "This script controls the setup and grading of this lab."
echo "Usage: $(basename $0) COMMAND"
echo "       $(basename $0) -h|--help"
echo "COMMAND is one of:"
echo "    setup - perform any setup steps for this lab on this machine"
echo "    grade - perform any grading steps and report on this machine"

}

function lab_setup {
    VMNAME=$1
    case $VMNAME in
        desktop)
            ERROR_MESSAGE="$CLNT_ERR"
            setup_desktop_users
            print_SUCCESS
            ;;
        server)
            ERROR_MESSAGE="$SERV_ERR"
            install_pkgs $SERV_PKG
            setup_server_samba
            print_SUCCESS
            ;;
        *)
            # Should never get here, but what the hey....
            print_FAIL && echo "Please run the lab-smbshare script on both the desktop and server"
            ;;
    esac
}

function lab_grade {
    VMNAME=$1
    case $VMNAME in
        desktop)
            FAIL=0
            check_cifs_utils_installed || FAIL=1
            check_cifs_multiuser_mountpoint || FAIL=1
            check_cifs_multiuser_fstab || FAIL=1
            check_cifs_multiuser_mount || FAIL=1
            echo
            echo -n "Overall result: "
            if [ ${FAIL} -eq 0 ]; then
              print_PASS
              echo "Congratulations! You've passed all requirements."
            else
              print_FAIL
              echo "Please check your work and try again."
            fi
            ;;
        server)
            FAIL=0
            echo "Please run grade on the desktop system."
            ;;
        *)
            # Should never get here, but what the hey....
            print_FAIL && echo "Something went wrong. Ask your instructor for assistance."
            ;;
    esac
}

# Main area

# Check if to be run as root (must do this first)
if [[ "${RUN_AS_ROOT}" == 'true' ]] && [[ "${EUID}" -gt "0" ]] ; then
  if [[ -x /usr/bin/sudo ]] ; then
    ${SUDO:-sudo} $0 "$@"
    exit
  else
    # Fail out if not running as root
    check_root
  fi
fi

# Process command line
# Parse input
case $1 in
    setup|grade)
        CMD=$1
        ;;
    -h|--help)
        print_usage
        exit 0
        ;;
    *)
        echo Bad option $1
        print_usage
        exit 1
        ;;
esac
# Validation
[ -z "$CMD" ] && debug "Missing command" && print_usage && exit 1

# Get local system information
get_X

# Branch based on short (without number) hostname
case $MYHOST in
    desktop|server)
        lab_$CMD $MYHOST
        ;;
    *)
        debug "Bad or missing hostname - $MYHOST"
        debug "This command needs to be run on desktop or server"
        exit 3
        ;;
esac