.\" Copyright (c) 2019, 2023 Shivank Garg .\" .\" This code was developed as a Google Summer of Code 2019 project .\" under the guidance of Bjoern A. Zeeb. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .Dd July 25, 2023 .Dt MAC_IPACL 4 .Os .Sh NAME .Nm mac_ipacl .Nd "IP Address access control policy" .Sh SYNOPSIS Add the following lines in your kernel configuration file to compile the IP address access control policy into your kernel: .Bd -ragged -offset indent .Cd "options MAC" .Cd "options MAC_IPACL" .Ed .Pp To load the mac_ipacl policy module at boot time, add the following line in your kernel configuration file: .Bd -ragged -offset indent .Cd "options MAC" .Ed .Pp and in .Xr loader.conf 5 add: .Pp .Dl "mac_ipacl_load=""YES""" .Sh DESCRIPTION The .Nm policy allows the root of the host to use the .Xr sysctl 8 interface to limit the .Xr VNET 9 jail's ability to set IPv4 and IPv6 addresses. So, the host can define rules for jails and their interfaces about IP addresses with .Xr sysctl 8 MIBs. .Pp Its default behavior is to deny all IP addresses for the jail if .Nm policy is enforced and allow/deny IP (or subnets) according to the .Va security.mac.ipacl.rules string specified with .Xr sysctl 8 .Ss Runtime Configuration The following .Xr sysctl 8 MIBs are used to control enforcement and behavior of this MAC Policy. .Bl -tag -width indent .It Va security.mac.ipacl.ipv4 Enforce .Nm for IPv4 addresses. (Default: 1). .It Va security.mac.ipacl.ipv6 Enforce .Nm for IPv6 addresses. (Default: 1). .It Va security.mac.ipacl.rules The IP address access control list is specified in the following format: .Pp .Sm off .D1 jid , allow , interface , addr_family , IP_addr / prefix Op @ jid , ... .Sm on .Bl -tag -width "interface" .It jid Describe the jail id of the jail for which the rule is written. .It allow 1 for allow and 0 for deny. Decides action performed for the rule. .It interface Name of the interface the rule is enforced for. If the interface is left empty then it is a wildcard to enforce the rule for all interfaces. .It addr_family Address family of the IP_addr. The input to be given as AF_INET or AF_INET6 string only. .It IP_addr IP address (or subnet) to be allowed/denied. Action depends on the prefix length. .It prefix Prefix length of the subnet to be enforced by the policy. -1 implies the policy is enforced for the individual IP address. For a non-negative value, a range of IP addresses (present in subnet) which is calculated as subnet = IP_addr & mask. .El .El .Sh EXAMPLES Behavior of the .Nm policy module for different inputs of sysctl variable: .Bl -tag -width "1." .It 1. Assign ipv4=1, ipv6=0 and rules="1,1,,AF_INET,169.254.123.123/-1" .Pp It allow only 169.254.123.123 IPv4 address for all interfaces (wildcard) of jail 1. It allows all IPv6 addresses since the policy is not enforced for IPv6. .It 2. Assign ipv4=1, ipv6=1 and rules="1,1,epair0b,AF_INET6,fe80::/32@1,0,epair0b,AF_INET6,fe80::abcd/-1" .Pp It denies all IPv4 addresses as the policy is enforced but no rules are specified about it. It allows all IPv6 addresses in subnet fe80::/32 except fe80::abcd for interface epair0b only. .It 3. Assign ipv4=1, ipv6=1, rules="2,1,,AF_INET6,fc00::/7@2,0,,AF_INET6,fc00::1111:2200/120@2,1,,AF_INET6,fc00::1111:2299/-1@1,1,,AF_INET,198.51.100.0/24" .Pp It allows IPv4 in subnet 198.51.100.0/24 for jail 2 and all interfaces. It allows IPv6 addresses in subnet fc00::/7 but denies subnet fc00::1111:2200/120, and allows individual IP fc00::1111:2299 from the denied subnet for all interfaces in jail 2. .El Please refer to mac/ipacl tests-framework for wide variety of examples on using the ipacl module. .Sh LIMITATIONS/PRECAUTIONS In the case where multiple rules are applicable to an IP address or a set of IP addresses, the rule that is defined later in the list determines the outcome, disregarding any previous rule for that IP address. .Sh FUTURE WORKS Rules are given with sysctl interface which gets very complex to give them all in command line. It has to be simplified with a better way to input those rules. .Sh SEE ALSO .Xr mac 4 , .Xr mac 9 .Sh AUTHORS The .Nm policy module was developed as a Google Summer of Code Project in 2019 by .An -nosplit .An "Shivank Garg" Aq Mt shivank@FreeBSD.org under the guidance of .An "Bjoern A. Zeeb" Aq Mt bz@FreeBSD.org .