#!/bin/bash

#DESC Configures OS email relay for sendmail.

#HELP usage: updateos config_relay {server_name} {login} {password} {port} {email_from} {y}
#HELP
#HELP First 4 are required. Email from (5th) can be "None". If it is, the generics table is not built.
#HELP The 6th clv anything to not prompt for vars.

#isRoot
ID=$(/usr/bin/id -u)
[ $ID -ne 0 ] && echo "You must be root to run $0." && exit 1

#a. Get Server.
[ "$1" == "" ] && echo -n "Enter SMTP Server Name/IP: " && read SERVER || SERVER="$1"
[ $"SERVER" == "" ] && echo "Server can't be null" && exit 1

#b. Get Login.
[ "$2" == "" ] && echo -n "Enter SMTP Server Login: " && read LOGIN || LOGIN="$2"
[ $"LOGIN" == "" ] && echo "Login can't be null" && exit 1

#c. Get SMTP Server Password.
[ "$3" == "" ] && echo -n "Enter SMTP Server Password: " && read PASSWD || PASSWD="$3"
[ $"PASSWD" == "" ] && echo "Password can't be null" && exit 1

#d. SMTP port.
[ "$4" == "" ] && echo -n "Enter Server SMTP port (Enter for none): " && read SMTP_PORT || SMTP_PORT="$4"
[ $"SMTP_PORT" == "" ] && echo "SMTP port can't be null" && exit 1

#e. Get Email From Address.
[ "$5" == "" ] && echo -n "Enter Server Email From Address (Enter for none): " && read EMAIL_FROM || EMAIL_FROM="$5"
[ "$EMAIL_FROM" == "" ] && EMAIL_FROM="None"

#f. Be Sure.
echo "SERVER: $SERVER"
echo "LOGIN: $LOGIN"
echo "PASSWORD: $PASSWD"
echo "SERVER EMAIL FROM ADDRESS: $EMAIL_FROM"

REPLY="$6"
[ "$REPLY" == "" ] && echo -n "Are these correct? (y/n):" && read REPLY
[ "$REPLY" != "y" ] && exit 1

#1. Remove postfix if there and install and enable sendmail instead.
yum repolist
[ "$?" != "0" ] && echo "Server needs to be registered with Redhat." && exit 1
yum -y remove postfix
yum -y install sendmail sendmail-cf
[ "$?" != "0" ] && echo "Unable to install the required packages." && exit 1
chkconfig sendmail on

#2. Create mail auth folder.
rm -rf /etc/mail/auth
mkdir /etc/mail/auth
chmod 777 /etc/mail/auth

#3. Backup config files just in case.
cp -f /etc/mail/sendmail.mc /tmp/sendmail.mc.`date +"%m%d%H%M%S"`
cp -f /etc/mail/sendmail.cf /tmp/sendmail.cf.`date +"%m%d%H%M%S"`

#4. Create generics table.
if [ "$EMAIL_FROM" != "None" ] && [ "`cat /etc/mail/genericstable | grep $EMAIL_FROM`" == "" ] ; then
     echo "root $EMAIL_FROM">/etc/mail/genericstable
     echo "root@localhost $EMAIL_FROM">>/etc/mail/genericstable
     echo "root@`hostname`    $EMAIL_FROM">>/etc/mail/genericstable
     echo "root@`hostname`.teleflora.com   $EMAIL_FROM">>/etc/mail/genericstable
     echo "rti $EMAIL_FROM">>/etc/mail/genericstable
     echo "rti@localhost $EMAIL_FROM">>/etc/mail/genericstable
     echo "rti@`hostname`    $EMAIL_FROM">>/etc/mail/genericstable
     echo "rti@`hostname`.teleflora.com    $EMAIL_FROM">>/etc/mail/genericstable
     echo "tfsupport $EMAIL_FROM">>/etc/mail/genericstable
     echo "tfsupport@localhost $EMAIL_FROM">>/etc/mail/genericstable
     echo "tfsupport@`hostname`    $EMAIL_FROM">>/etc/mail/genericstable
     echo "tfsupport@`hostname`.teleflora.com    $EMAIL_FROM">>/etc/mail/genericstable
fi

#5. Make changes to sendmail.mc and build new sendmail.cf.
cp -f /etc/mail/sendmail.mc /etc/mail/sendmail.mc.new
sed -i '/^MAILER/d' /etc/mail/sendmail.mc.new
sed -i '/MAILER(cyrusv2)/d' /etc/mail/sendmail.mc.new
echo "GENERICS_DOMAIN(\`localhost')dnl">>/etc/mail/sendmail.mc.new
echo "GENERICS_DOMAIN(\``hostname`')dnl">>/etc/mail/sendmail.mc.new
echo "GENERICS_DOMAIN(\``hostname`.teleflora.com')dnl">>/etc/mail/sendmail.mc.new
echo "define(\`RELAY_MAILER_ARGS',\`TCP \$h $SMTP_PORT')dnl">>/etc/mail/sendmail.mc.new
echo "define(\`ESMTP_MAILER_ARGS',\`TCP \$h $SMTP_PORT')dnl">>/etc/mail/sendmail.mc.new
echo "define(\`SMART_HOST',\`$SERVER')dnl">>/etc/mail/sendmail.mc.new
echo "define(\`confAUTH_MECHANISMS',\`EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl">>/etc/mail/sendmail.mc.new
echo "FEATURE(authinfo,\`hash /etc/mail/auth/authinfo')dnl">>/etc/mail/sendmail.mc.new
echo "FEATURE(\`genericstable')dnl">>/etc/mail/sendmail.mc.new
echo "MAILER(smtp)dnl">>/etc/mail/sendmail.mc.new
echo "MAILER(procmail)dnl">>/etc/mail/sendmail.mc.new
m4 /etc/mail/sendmail.mc.new > /etc/mail/sendmail.cf
mv -f /etc/mail/sendmail.mc.new /etc/mail/sendmail.mc

#6. Create authentication file and build authentication db.
echo "AuthInfo:$SERVER \"U:$LOGIN\"  \"P:$PASSWD\"   \"M:PLAIN\"">/etc/mail/auth/authinfo
makemap hash /etc/mail/auth/authinfo < /etc/mail/auth/authinfo

#7. Set permissions on authentication files.
chmod 600 /etc/mail/auth/authinfo
chmod 700 /etc/mail/auth

#8. Restart sendmail.
service sendmail restart

echo "Done."
exit 0