# # hosts.allow access control file for "tcp wrapped" apps. # $FreeBSD$ # # NOTE: The hosts.deny file is not longer used. Instead, put both 'allow' # and 'deny' rules in the hosts.allow file. # see hosts_options(5) for the format of this file. # hosts_access(5) no longer fully applies. # _____ _ _ # | ____| __ __ __ _ _ __ ___ _ __ | | ___ | | # | _| \ \/ / / _` | | '_ ` _ \ | '_ \ | | / _ \ | | # | |___ > < | (_| | | | | | | | | |_) | | | | __/ |_| # |_____| /_/\_\ \__,_| |_| |_| |_| | .__/ |_| \___| (_) # |_| # !!! This is an example! You will need to modify it for your specific # !!! requirements! # Start by allowing everything (this prevents the rest of the file # from working, so remove it when you need protection). # The rules here work on a "First match wins" basis. ALL : ALL : allow # Wrapping sshd(8) is not normally a good idea, but if you # need to do it, here's how #sshd : .evil.cracker.example.com : deny # Prevent those with no reverse DNS from connecting. ALL : PARANOID : RFC931 20 : deny # Allow anything from localhost ALL : localhost : allow ALL : my.machine.example.com : allow # Sendmail can help protect you against spammers and relay-rapers sendmail : localhost : allow sendmail : .nice.guy.example.com : allow sendmail : .evil.cracker.example.com : deny sendmail : ALL : allow # Exim is an alternative to sendmail, available in the ports tree exim : localhost : allow exim : .nice.guy.example.com : allow exim : .evil.cracker.example.com : deny exim : ALL : allow # Portmapper is used for all RPC services; protect your NFS! # (IP addresses rather than hostnames *MUST* be used here) portmap : localhost : allow portmap : .nice.guy.example.com : allow portmap : .evil.cracker.example.com : deny portmap : ALL : allow # Provide a small amount of protection for ftpd ftpd : localhost : allow ftpd : .nice.guy.example.com : allow ftpd : .evil.cracker.example.com : deny ftpd : ALL : allow # You need to be clever with finger; do _not_ backfinger!! You can easily # start a "finger war". fingerd : ALL \ : spawn (echo Finger. | \ /usr/bin/mail -s "tcpd\: %u@%h[%a] fingered me!" root) & \ : deny # The rest of the daemons are protected. Backfinger and log by email. ALL : ALL \ : severity auth.info : spawn (/usr/bin/finger -l @%h | \ /usr/bin/mail -s "tcpd\: %u@%h[%a] tried to use %d (denied)" root) & \ : twist /bin/echo "You are not welcome to use %d from %h."