o Document various sysctl's available for managing services available

within jail()
This commit is contained in:
Robert Watson 2000-10-31 01:47:59 +00:00
parent cb1f0db9db
commit 98965adac8
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=68026

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@ -281,6 +281,45 @@ jail.set_hostname_allowed=0
.Pp
In a future version of FreeBSD, the mechanisms for managing jails will be
more refined.
.Sh SYSCTL MIB ENTRIES
Certain aspects of the jail containments environment may be modified from
the host environment using
.Xr sysctl 8
MIB variables.
Currently, these variables affect all jails on the system, although in
the future this functionality may be finer grained.
.Pp
.Ss jail.set_hostname_allowed
This MIB entry determines whether or not processes within a jail are
allowed to change their hostname via
.Xr hostname 1
or
.Xr sethostname 3 .
In the current jail implementation, the ability to set the hostname from
within the jail can impact management tools relying on the accuracy of jail
information in /proc.
As such, this should be disabled in environments where privileged access to
jails is given out to untrusted parties.
.Ss jail.socket_unixiproute_only
The jail functionality binds an IPv4 address to each jail, and limits
access to other network addresses in the IPv4 space that may be available
in the host environment.
However, jail is not currently able to limit access to other network
protocol stacks that have not had jail functionality added to them.
As such, by default, processes within jails may only access protocols
in the following domains: PF_LOCAL, PF_INET, and PF_ROUTE, permitting
them access to UNIX domain sockets, IPv4 addresses, and routing sockets.
To enable access to other domains, this MIB variable may be set to
0.
.Ss jail.sysvipc_allowed
This MIB entry determines whether or not processes within a jail have access
to System V IPC primitives.
In the current jail implementation, System V primitives share a single
namespace across the host and jail environments, meaning that processes
within a jail would be able to communicate with (and potentially interfere
with) processes outside of the jail, and in other jails.
As such, this functionality is disabled by default, but can be enabled
by setting this MIB entry to 1.
.Sh SEE ALSO
.Xr newaliases 1 ,
.Xr ps 1 ,