hosts.allow revision 81890
155825Speter# 2218822Sdim# hosts.allow access control file for "tcp wrapped" applications. 3114370Speter# $FreeBSD: head/etc/hosts.allow 81890 2001-08-18 14:22:52Z dwmalone $ 439818Speter# 5114370Speter# NOTE: The hosts.deny file is deprecated. 639818Speter# Place both 'allow' and 'deny' rules in the hosts.allow file. 739818Speter# See hosts_options(5) for the format of this file. 839818Speter# hosts_access(5) no longer fully applies. 9220090Salc 10220090Salc# _____ _ _ 11114370Speter# | ____| __ __ __ _ _ __ ___ _ __ | | ___ | | 12114370Speter# | _| \ \/ / / _` | | '_ ` _ \ | '_ \ | | / _ \ | | 13218822Sdim# | |___ > < | (_| | | | | | | | | |_) | | | | __/ |_| 14114370Speter# |_____| /_/\_\ \__,_| |_| |_| |_| | .__/ |_| \___| (_) 15114370Speter# |_| 16114370Speter# !!! This is an example! You will need to modify it for your specific 17114370Speter# !!! requirements! 18114370Speter 19114370Speter 20114370Speter# Start by allowing everything (this prevents the rest of the file 21114370Speter# from working, so remove it when you need protection). 22114370Speter# The rules here work on a "First match wins" basis. 23114370SpeterALL : ALL : allow 24114370Speter 25114370Speter# Wrapping sshd(8) is not normally a good idea, but if you 26114370Speter# need to do it, here's how 27218822Sdim#sshd : .evil.cracker.example.com : deny 28218822Sdim 29114370Speter# Protect against simple DNS spoofing attacks by checking that the 30114370Speter# forward and reverse records for the remote host match. If a mismatch 31114370Speter# occurs, access is denied, and any positive ident response within 32114370Speter# 20 seconds is logged. No protection is afforded against DNS poisoning, 33114370Speter# IP spoofing or more complicated attacks. Hosts with no reverse DNS 34114370Speter# pass this rule. 35114370SpeterALL : PARANOID : RFC931 20 : deny 36114370Speter 37114370Speter# Allow anything from localhost. Note that an IP address (not a host 38114370Speter# name) *MUST* be specified for rpcbind(8). 39114370SpeterALL : localhost 127.0.0.1 : allow 40114370SpeterALL : my.machine.example.com 192.0.2.35 : allow 41114370Speter 42114370Speter# To use IPv6 addresses you must enclose them in []'s 43218822SdimALL : [fe80::%fxp0]/10 : allow 44218822SdimALL : [fe80::]/10 : deny 45218822SdimALL : [3ffe:fffe:2:1:2:3:4:3fe1] : deny 46218822SdimALL : [3ffe:fffe:2:1::]/64 : allow 47218822Sdim 48218822Sdim# Sendmail can help protect you against spammers and relay-rapers 49114370Spetersendmail : localhost : allow 50114370Spetersendmail : .nice.guy.example.com : allow 51114370Spetersendmail : .evil.cracker.example.com : deny 5239818Spetersendmail : ALL : allow 53114370Speter 54114370Speter# Exim is an alternative to sendmail, available in the ports tree 55114370Speterexim : localhost : allow 56114370Speterexim : .nice.guy.example.com : allow 57114370Speterexim : .evil.cracker.example.com : deny 58114370Speterexim : ALL : allow 59218822Sdim 6039818Speter# Rpcbind is used for all RPC services; protect your NFS! 6139818Speter# (IP addresses rather than hostnames *MUST* be used here) 62114370Speterrpcbind : 192.0.2.32/255.255.255.224 : allow 63114370Speterrpcbind : 192.0.2.96/255.255.255.224 : allow 64114370Speterrpcbind : ALL : deny 65114370Speter 66114370Speter# Provide a small amount of protection for ftpd 67114370Speterftpd : localhost : allow 68114370Speterftpd : .nice.guy.example.com : allow 6939818Speterftpd : .evil.cracker.example.com : deny 70114370Speterftpd : ALL : allow 71114370Speter 72114370Speter# You need to be clever with finger; do _not_ backfinger!! You can easily 73218822Sdim# start a "finger war". 74218822Sdimfingerd : ALL \ 7539818Speter : spawn (echo Finger. | \ 7639818Speter /usr/bin/mail -s "tcpd\: %u@%h[%a] fingered me!" root) & \ 77218822Sdim : deny 78218822Sdim 79218822Sdim# The rest of the daemons are protected. 80218822SdimALL : ALL \ 81218822Sdim : severity auth.info \ 82218822Sdim : twist /bin/echo "You are not welcome to use %d from %h." 83218822Sdim