jail_getid
, jail_getname
,
jail_setv
, jail_getv
,
jailparam_all
, jailparam_init
,
jailparam_import
,
jailparam_import_raw
,
jailparam_set
, jailparam_get
,
jailparam_export
,
jailparam_free
—
create and manage system jails
Jail Library (libjail, -ljail)
#include <sys/param.h>
#include <sys/jail.h>
#include <jail.h>
extern char jail_errmsg[];
int
jail_getid
(const
char *name);
char *
jail_getname
(int
jid);
int
jail_setv
(int
flags, ...);
int
jail_getv
(int
flags, ...);
int
jailparam_all
(struct
jailparam **jpp);
int
jailparam_init
(struct
jailparam *jp, const char
*name);
int
jailparam_import
(struct
jailparam *jp, const char
*value);
int
jailparam_import_raw
(struct
jailparam *jp, void
*value, size_t
valuelen);
int
jailparam_set
(struct
jailparam *jp, unsigned
njp, int
flags);
int
jailparam_get
(struct
jailparam *jp, unsigned
njp, int
flags);
char *
jailparam_export
(struct
jailparam *jp);
void
jailparam_free
(struct
jailparam *jp, unsigned
njp);
The jail
library is an interface to the
jail_set(2)
and
jail_get(2)
system calls, and the security.jail.param MIB entries.
It simplifies the conversion of prison parameters between internal and string
formats, allowing the setting and querying of prisons without knowing the
parameter formats.
The jail_getid
() function returns the JID
of the jail identified by name, or -1 if the jail does
not exist.
The jail_getname
() function returns the
name of the jail identified by jid, or
NULL
if the jail does not exist.
The jail_setv
() function takes a
null-terminated list of name and value strings, and passes it to
jail_set(2).
The jail_getv
() function takes a
null-terminated list of name and value strings, and passes it to
jail_get(2).
It is the caller's responsibility to ensure that the value strings point to
buffers large enough to hold the string representation of the returned
parameters.
The jailparam_all
() function sets
jpp to a list of all known jail parameters, and
returns the number of parameters. The list should later be freed with
jailparam_free
() and
free(3).
The jailparam_init
() function clears a
parameter record and copies the name to it. After use,
it should be freed with jailparam_free
().
The jailparam_import
() function adds a
value to a parameter record, converting it from a
string to its native form. The
jailparam_import_raw
() function adds a value without
performing any conversion.
The jailparam_set
() function passes a list
of parameters to
jail_set(2).
The parameters are assumed to have been created with
jailparam_init
() and
jailparam_import
().
The jailparam_get
() function passes a list
of parameters to
jail_get(2).
The parameters are assumed to have been created with
jailparam_init
() or
jailparam_list
(), with one parameter (the key)
having been given a value with
jailparam_import
().
The jailparam_export
() function returns
the string equivalent of a parameter value. The returned string should be
freed after use.
The jailparam_free
() function frees the
stored names and values in a parameter list. If the list itself came from
jailparam_all
(), it should be freed as well.
The jail_getid
(), jail_setv
(),
jail_getv
(), jailparam_set
()
and jailparam_get
() functions return a JID on success,
or -1 on error.
The jail_getname
() and
jailparam_export
() functions return a dynamically
allocated string on success, or NULL
on error.
The jailparam_all
() function returns the
number of parameters on success, or -1 on error.
The jailparam_init
(),
jailparam_import
() and
jailparam_import_raw
() functions return 0 on
success, or -1 on error.
Whenever an error is returned, errno is set,
and the global string jail_errmsg contains a
description of the error, possibly from
jail_set(2)
or
jail_get(2).
Set the hostname of jail “foo” to “foo.bar”:
jail_setv(JAIL_UPDATE, "name", "foo", "host.hostname", "foo.bar",
NULL);
OR:
struct jailparam params[2];
jailparam_init(¶ms[0], "name");
jailparam_import(¶ms[0], "foo");
jailparam_init(¶ms[1], "host.hostname");
jailparam_import(¶ms[1], "foo.bar");
jailparam_set(params, 2, JAIL_UPDATE);
jailparam_free(params, 2);
Retrieve the hostname of jail “foo”:
char hostname[MAXHOSTNAMELEN];
jail_getv(0, "name", "foo", "host.hostname", hostname, NULL);
OR:
struct jailparam params[2];
jailparam_init(¶ms[0], "name");
jailparam_import(¶ms[0], "foo");
jailparam_init(¶ms[1], "host.hostname");
jailparam_get(params, 2, 0);
hostname = jailparam_export(¶ms[1]);
jailparam_free(params, 2);
...
free(hostname);
The jail
functions may return errors from
jail_set(2),
jail_get(2),
malloc(3)
or
sysctl(3).
In addition, the following errors are possible:
- [
EINVAL
]
- A parameter value cannot be converted from the passed string to its
internal form.
- [
ENOENT
]
- The named parameter does not exist.
- [
ENOENT
]
- A parameter is of an unknown type.
The jail
library first appeared in
FreeBSD 8.0.