freebsd-dev/sys/kern/kern_jail.c
rwatson d221b0006a o Move per-process jail pointer (p->pr_prison) to inside of the subject
credential structure, ucred (cr->cr_prison).
o Allow jail inheritence to be a function of credential inheritence.
o Abstract prison structure reference counting behind pr_hold() and
  pr_free(), invoked by the similarly named credential reference
  management functions, removing this code from per-ABI fork/exit code.
o Modify various jail() functions to use struct ucred arguments instead
  of struct proc arguments.
o Introduce jailed() function to determine if a credential is jailed,
  rather than directly checking pointers all over the place.
o Convert PRISON_CHECK() macro to prison_check() function.
o Move jail() function prototypes to jail.h.
o Emulate the P_JAILED flag in fill_kinfo_proc() and no longer set the
  flag in the process flags field itself.
o Eliminate that "const" qualifier from suser/p_can/etc to reflect
  mutex use.

Notes:

o Some further cleanup of the linux/jail code is still required.
o It's now possible to consider resolving some of the process vs
  credential based permission checking confusion in the socket code.
o Mutex protection of struct prison is still not present, and is
  required to protect the reference count plus some fields in the
  structure.

Reviewed by:	freebsd-arch
Obtained from:	TrustedBSD Project
2001-02-21 06:39:57 +00:00

197 lines
3.8 KiB
C

/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $FreeBSD$
*
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/sysproto.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/jail.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <netinet/in.h>
MALLOC_DEFINE(M_PRISON, "prison", "Prison structures");
SYSCTL_NODE(, OID_AUTO, jail, CTLFLAG_RW, 0,
"Jail rules");
int jail_set_hostname_allowed = 1;
SYSCTL_INT(_jail, OID_AUTO, set_hostname_allowed, CTLFLAG_RW,
&jail_set_hostname_allowed, 0,
"Processes in jail can set their hostnames");
int jail_socket_unixiproute_only = 1;
SYSCTL_INT(_jail, OID_AUTO, socket_unixiproute_only, CTLFLAG_RW,
&jail_socket_unixiproute_only, 0,
"Processes in jail are limited to creating UNIX/IPv4/route sockets only");
int jail_sysvipc_allowed = 0;
SYSCTL_INT(_jail, OID_AUTO, sysvipc_allowed, CTLFLAG_RW,
&jail_sysvipc_allowed, 0,
"Processes in jail can use System V IPC primitives");
int
jail(p, uap)
struct proc *p;
struct jail_args /* {
syscallarg(struct jail *) jail;
} */ *uap;
{
int error;
struct prison *pr;
struct jail j;
struct chroot_args ca;
/* Implicitly fail if already in jail. */
error = suser(p);
if (error)
return (error);
error = copyin(uap->jail, &j, sizeof j);
if (error)
return (error);
if (j.version != 0)
return (EINVAL);
MALLOC(pr, struct prison *, sizeof *pr , M_PRISON, M_WAITOK | M_ZERO);
error = copyinstr(j.hostname, &pr->pr_host, sizeof pr->pr_host, 0);
if (error)
goto bail;
pr->pr_ip = j.ip_number;
ca.path = j.path;
error = chroot(p, &ca);
if (error)
goto bail;
p->p_ucred = crcopy(p->p_ucred);
p->p_ucred->cr_prison = pr;
pr->pr_ref = 1;
return (0);
bail:
FREE(pr, M_PRISON);
return (error);
}
void
prison_free(struct prison *pr)
{
pr->pr_ref--;
if (pr->pr_ref == 0) {
if (pr->pr_linux != NULL)
FREE(pr->pr_linux, M_PRISON);
FREE(pr, M_PRISON);
}
}
void
prison_hold(struct prison *pr)
{
pr->pr_ref++;
}
int
prison_ip(struct ucred *cred, int flag, u_int32_t *ip)
{
u_int32_t tmp;
if (!jailed(cred))
return (0);
if (flag)
tmp = *ip;
else
tmp = ntohl(*ip);
if (tmp == INADDR_ANY) {
if (flag)
*ip = cred->cr_prison->pr_ip;
else
*ip = htonl(cred->cr_prison->pr_ip);
return (0);
}
if (cred->cr_prison->pr_ip != tmp)
return (1);
return (0);
}
void
prison_remote_ip(struct ucred *cred, int flag, u_int32_t *ip)
{
u_int32_t tmp;
if (!jailed(cred))
return;
if (flag)
tmp = *ip;
else
tmp = ntohl(*ip);
if (tmp == 0x7f000001) {
if (flag)
*ip = cred->cr_prison->pr_ip;
else
*ip = htonl(cred->cr_prison->pr_ip);
return;
}
return;
}
int
prison_if(struct ucred *cred, struct sockaddr *sa)
{
struct sockaddr_in *sai = (struct sockaddr_in*) sa;
int ok;
if ((sai->sin_family != AF_INET) && jail_socket_unixiproute_only)
ok = 1;
else if (sai->sin_family != AF_INET)
ok = 0;
else if (cred->cr_prison->pr_ip != ntohl(sai->sin_addr.s_addr))
ok = 1;
else
ok = 0;
return (ok);
}
/*
* Return 0 if jails permit p1 to frob p2, otherwise ESRCH.
*/
int
prison_check(cred1, cred2)
struct ucred *cred1, *cred2;
{
if (jailed(cred1)) {
if (!jailed(cred2))
return (ESRCH);
if (cred2->cr_prison != cred1->cr_prison)
return (ESRCH);
}
return (0);
}
/*
* Return 1 if the passed credential is in a jail, otherwise 0.
*/
int
jailed(cred)
struct ucred *cred;
{
return (cred->cr_prison != NULL);
}