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jail_attach (2)

>> jail_attach (2) ( FreeBSD man: Системные вызовы )

BSD mandoc

NAME



jail , jail_attach

 - imprison current process and future descendants

LIBRARY

Lb libc

SYNOPSIS

#include <sys/param.h>
#include <sys/jail.h>
int jail (struct jail *jail);
int jail_attach (int jid);

DESCRIPTION

The jail ();
system call sets up a jail and locks the current process in it.

The argument is a pointer to a structure describing the prison:

struct jail {
        u_int32_t       version;
        char            *path;
        char            *hostname;
        u_int32_t       ip_number;
};

``version '' defines the version of the API in use. It should be set to zero at this time.

The ``path '' pointer should be set to the directory which is to be the root of the prison.

The ``hostname '' pointer can be set to the hostname of the prison. This can be changed from the inside of the prison.

The ``ip_number '' can be set to the IP number assigned to the prison.

The jail_attach ();
system call attaches the current process to an existing jail, identified by Fa jid .

RETURN VALUES

If successful, jail ();
returns a non-negative integer, termed the jail identifier (JID). It returns -1 on failure, and sets errno to indicate the error.

Rv -std jail_attach

PRISON?

Once a process has been put in a prison, it and its descendants cannot escape the prison.

Inside the prison, the concept of ``superuser'' is very diluted. In general, it can be assumed that nothing can be mangled from inside a prison which does not exist entirely inside that prison. For instance the directory tree below ``path '' can be manipulated all the ways a root can normally do it, including ``rm -rf /* '' but new device special nodes cannot be created because they reference shared resources (the device drivers in the kernel). The effective ``securelevel'' for a process is the greater of the global ``securelevel'' or, if present, the per-jail ``securelevel''

All IP activity will be forced to happen to/from the IP number specified, which should be an alias on one of the network interfaces.

It is possible to identify a process as jailed by examining ``/proc/<pid>/status '' it will show a field near the end of the line, either as a single hyphen for a process at large, or the hostname currently set for the prison for jailed processes.