hosts.allow revision 50472
1178476Sjb# 2178476Sjb# hosts.allow access control file for "tcp wrapped" apps. 3178476Sjb# $FreeBSD: head/etc/hosts.allow 50472 1999-08-27 23:37:10Z peter $ 4178476Sjb# 5178476Sjb# NOTE: The hosts.deny file is not longer used. Instead, put both 'allow' 6178476Sjb# and 'deny' rules in the hosts.allow file. 7178476Sjb# see hosts_options(5) for the format of this file. 8178476Sjb# hosts_access(5) no longer fully applies. 9178476Sjb 10178476Sjb# This is an example! You will need to modify it for your specific 11178476Sjb# requirements! 12178476Sjb 13178476Sjb# Start by allowing everything (this prevents the rest of the file 14178476Sjb# from working, so remove it when you need protection). 15178476Sjb# The rules here work on a "First match wins" basis. 16178476SjbALL : ALL : allow 17178476Sjb 18178476Sjb# Wrapping sshd(8) is not normally a good idea, but if you 19178476Sjb# need to do it, here's how 20178476Sjb#sshd : .evil.cracker.example.com : deny 21178476Sjb 22178476Sjb# Prevent those with no reverse DNS from connecting. 23178476SjbALL : PARANOID : RFC931 20 : deny 24178476Sjb 25178476Sjb# Allow anything from localhost 26178476SjbALL : localhost : allow 27178476SjbALL : my.machine.example.com : allow 28178476Sjb 29178476Sjb# Sendmail can help protect you against spammers and relay-rapers 30178476Sjbsendmail : localhost : allow 31178476Sjbsendmail : .nice.guy.example.com : allow 32178476Sjbsendmail : .evil.cracker.example.com : deny 33178476Sjbsendmail : ALL : allow 34178476Sjb 35178476Sjb# Exim is an alternative to sendmail, available in the ports tree 36178476Sjbexim : localhost : allow 37178476Sjbexim : .nice.guy.example.com : allow 38178476Sjbexim : .evil.cracker.example.com : deny 39178476Sjbexim : ALL : allow 40178476Sjb 41178476Sjb# Portmapper is used for all RPC services; protect your NFS! 42178476Sjbportmap : localhost : allow 43178476Sjbportmap : .nice.guy.example.com : allow 44178476Sjbportmap : .evil.cracker.example.com : deny 45178476Sjbportmap : ALL : allow 46178476Sjb 47178476Sjb# Provide a small amount of protection for ftpd 48178476Sjbftpd : localhost : allow 49178476Sjbftpd : .nice.guy.example.com : allow 50178476Sjbftpd : .evil.cracker.example.com : deny 51178476Sjbftpd : ALL : allow 52178476Sjb 53178476Sjb# You need to be clever with finger; do _not_ backfinger!! You can easily 54178476Sjb# start a "finger war". 55178476Sjbfingerd : ALL \ 56178476Sjb : spawn (echo Finger. | \ 57178476Sjb /usr/bin/mail -s "tcpd\: %u@%h[%a] fingered me!" root) & \ 58178476Sjb : deny 59178476Sjb 60178476Sjb# The rest of the daemons are protected. Backfinger and log by email. 61178476SjbALL : ALL \ 62178476Sjb : severity auth.info : spawn (/usr/bin/finger -l @%h | \ 63178476Sjb /usr/bin/mail -s "tcpd\: %u@%h[%a] tried to use %d (denied)" root) & \ 64178476Sjb : twist /bin/echo "You are not welcome to use %d from %h." 65178476Sjb