2 .\"----------------------------------------------------------------------------
3 .\""THE BEER-WARE LICENSE" (Revision 42):
4 .\"<phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
5 .\"can do whatever you want with this stuff. If we meet some day, and you think
6 .\"this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
7 .\"----------------------------------------------------------------------------
9 .\"$FreeBSD: src/lib/libc/sys/jail.2,v 1.10.2.10 2002/12/12 05:26:38 trhodes Exp $
10 .\"$DragonFly: src/lib/libc/sys/jail.2,v 1.2 2003/06/17 04:26:47 dillon Exp $
17 .Nd imprison current process and future decendants
24 .Fn jail "struct jail *jail"
28 system call sets up a jail and locks the current process in it.
30 The argument is a pointer to a structure describing the prison:
31 .Bd -literal -offset indent
41 defines the version of the API in use. It should be set to zero at this time.
45 pointer should be set to the directory which is to be the root of the
50 pointer can be set to the hostname of the prison. This can be changed
51 from the inside of the prison.
55 can be set to the IP number assigned to the prison.
57 Once a process has been put in a prison, it and its decendants cannot escape
58 the prison. It is not possible to add a process to a preexisting prison.
60 Inside the prison, the concept of "superuser" is very diluted. In general,
61 it can be assumed that nothing can be mangled from inside a prison which
62 does not exist entirely inside that prison. For instance the directory
65 can be manipulated all the ways a root can normally do it, including
67 but new device special nodes cannot be created because they reference
68 shared resources (the device drivers in the kernel).
70 All IP activity will be forced to happen to/from the IP number specified,
71 which should be an alias on one of the network interfaces.
73 It is possible to identify a process as jailed by examining
74 .Dq Li /proc/<pid>/status :
75 it will show a field near the end of the line, either as
76 a single hyphen for a process at large, or the hostname currently
77 set for the prison for jailed processes.
83 The version number of the argument is not correct.
90 internally, so it can fail for all the same reasons.
93 manual page for details.
100 function call appeared in
103 The jail feature was written by
104 .An Poul-Henning Kamp
106 .Dq Li http://www.rndassociates.com/
107 who contributed it to