create an empty jail with libjail

[joris dedieu]

Hi,
I try to create an empty jail using libjail. Something equivalent to
"jail -c name=empty host.hostname=empty path=/var/empty persist". I've
tried with jailparam_import and jail_setv on 8.3 and 9.1 but both
failed. I can't find where my code is wrong.

Eg 1:

#include <sys/param.h>
#include <sys/jail.h>
#include <jail.h>

int
main(int argc, char **argv)
{
        struct jailparam params[4];
        int jid;
        jailparam_init(&params[0], "name");
        jailparam_import(&params[0], "empty");
        jailparam_init(&params[1], "host.hostname");
        jailparam_import(&params[1], "empty.rmdir.fr");
        jailparam_init(&params[2], "path");
        jailparam_import(&params[2], "/var/empty");
        /*jailparam_init(&params[3], "persist");
        jailparam_import(&params[3], NULL);*/

        if((jid = jailparam_set(params, 4, JAIL_CREATE)) == -1)
                err(1, "jailparam_set");
        printf("jid is %d", jid);
        return 0;
}


 jailparam_import fails with EINVAL  (from libc's jail_set but i don't
know why)


Eg 2:

#include <sys/param.h>
#include <sys/jail.h>
#include <jail.h>

int
main(int argc, char **argv)
{
        int jid;
        if((jid = jail_setv(JAIL_CREATE,
                        "name", "empty"
                        "host.hostname", "empty",
                        "path", "/var/empty",
                        "persist", NULL, NULL
                        )) == -1)
                err(1, "jail_setv");
        printf("jid is %d", jid);
        return 0;
}

jail_setv fails with ENOENT. I think it comes from  libjail's
jailparam_type as persist is not in security.jail.param's mib in
prison 0 (see .lib/libjail/jail.c:854).


I really don't understand why it doesn't work. If someone could have a
little look, it would be grate.

Regards
Joris