freebsd-dev/sys/security/mac_bsdextended/mac_bsdextended.c
Robert Watson 177142e458 Pass active_cred and file_cred into the MAC framework explicitly
for mac_check_vnode_{poll,read,stat,write}().  Pass in fp->f_cred
when calling these checks with a struct file available.  Otherwise,
pass NOCRED.  All currently MAC policies use active_cred, but
could now offer the cached credential semantic used for the base
system security model.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-08-19 19:04:53 +00:00

751 lines
19 KiB
C

/*-
* Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
* Copyright (c) 2001, 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by NAI Labs,
* the Security Research Division of Network Associates, Inc. under
* DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA
* CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* Developed by the TrustedBSD Project.
* "BSD Extended" MAC policy, allowing the administrator to impose
* mandatory rules regarding users and some system objects.
*
* XXX: Much locking support required here.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/acl.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <net/bpfdesc.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_var.h>
#include <vm/vm.h>
#include <sys/mac_policy.h>
#include <security/mac_bsdextended/mac_bsdextended.h>
SYSCTL_DECL(_security_mac);
SYSCTL_NODE(_security_mac, OID_AUTO, bsdextended, CTLFLAG_RW, 0,
"TrustedBSD extended BSD MAC policy controls");
static int mac_bsdextended_enabled = 1;
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, enabled, CTLFLAG_RW,
&mac_bsdextended_enabled, 0, "Enforce extended BSD policy");
TUNABLE_INT("security.mac.bsdextended.enabled", &mac_bsdextended_enabled);
MALLOC_DEFINE(M_MACBSDEXTENDED, "mac_bsdextended", "BSD Extended MAC rule");
#define MAC_BSDEXTENDED_MAXRULES 250
static struct mac_bsdextended_rule *rules[MAC_BSDEXTENDED_MAXRULES];
static int rule_count = 0;
static int rule_slots = 0;
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_count, CTLFLAG_RD,
&rule_count, 0, "Number of defined rules\n");
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_slots, CTLFLAG_RD,
&rule_slots, 0, "Number of used rule slots\n");
static int mac_bsdextended_debugging;
SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, debugging, CTLFLAG_RW,
&mac_bsdextended_debugging, 0, "Enable debugging on failure");
static int
mac_bsdextended_rule_valid(struct mac_bsdextended_rule *rule)
{
if ((rule->mbr_subject.mbi_flags | MBI_BITS) != MBI_BITS)
return (EINVAL);
if ((rule->mbr_object.mbi_flags | MBI_BITS) != MBI_BITS)
return (EINVAL);
if ((rule->mbr_mode | VALLPERM) != VALLPERM)
return (EINVAL);
return (0);
}
static int
sysctl_rule(SYSCTL_HANDLER_ARGS)
{
struct mac_bsdextended_rule temprule, *ruleptr;
u_int namelen;
int error, index, *name;
name = (int *)arg1;
namelen = arg2;
/* printf("bsdextended sysctl handler (namelen %d)\n", namelen); */
if (namelen != 1)
return (EINVAL);
index = name[0];
if (index < 0 || index > rule_slots + 1)
return (ENOENT);
if (rule_slots >= MAC_BSDEXTENDED_MAXRULES)
return (ENOENT);
if (req->oldptr) {
if (rules[index] == NULL)
return (ENOENT);
error = SYSCTL_OUT(req, rules[index], sizeof(*rules[index]));
if (error)
return (error);
}
if (req->newptr) {
if (req->newlen == 0) {
/* printf("deletion\n"); */
ruleptr = rules[index];
if (ruleptr == NULL)
return (ENOENT);
rule_count--;
rules[index] = NULL;
FREE(ruleptr, M_MACBSDEXTENDED);
return(0);
}
error = SYSCTL_IN(req, &temprule, sizeof(temprule));
if (error)
return (error);
error = mac_bsdextended_rule_valid(&temprule);
if (error)
return (error);
if (rules[index] == NULL) {
/* printf("addition\n"); */
MALLOC(ruleptr, struct mac_bsdextended_rule *,
sizeof(*ruleptr), M_MACBSDEXTENDED, M_WAITOK |
M_ZERO);
*ruleptr = temprule;
rules[index] = ruleptr;
if (index+1 > rule_slots)
rule_slots = index+1;
rule_count++;
} else {
/* printf("replacement\n"); */
*rules[index] = temprule;
}
}
return (0);
}
SYSCTL_NODE(_security_mac_bsdextended, OID_AUTO, rules,
CTLFLAG_RW, sysctl_rule, "BSD extended MAC rules");
static void
mac_bsdextended_init(struct mac_policy_conf *mpc)
{
/* Initialize ruleset lock. */
/* Register dynamic sysctl's for rules. */
}
static void
mac_bsdextended_destroy(struct mac_policy_conf *mpc)
{
/* Tear down sysctls. */
/* Destroy ruleset lock. */
}
static int
mac_bsdextended_rulecheck(struct mac_bsdextended_rule *rule,
struct ucred *cred, uid_t object_uid, gid_t object_gid, mode_t acc_mode)
{
int match;
/*
* Is there a subject match?
*/
if (rule->mbr_subject.mbi_flags & MBI_UID_DEFINED) {
match = (rule->mbr_subject.mbi_uid == cred->cr_uid ||
rule->mbr_subject.mbi_uid == cred->cr_ruid ||
rule->mbr_subject.mbi_uid == cred->cr_svuid);
if (rule->mbr_subject.mbi_flags & MBI_NEGATED)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_subject.mbi_flags & MBI_GID_DEFINED) {
match = (groupmember(rule->mbr_subject.mbi_gid, cred) ||
rule->mbr_subject.mbi_gid == cred->cr_rgid ||
rule->mbr_subject.mbi_gid == cred->cr_svgid);
if (rule->mbr_subject.mbi_flags & MBI_NEGATED)
match = !match;
if (!match)
return (0);
}
/*
* Is there an object match?
*/
if (rule->mbr_object.mbi_flags & MBI_UID_DEFINED) {
match = (rule->mbr_object.mbi_uid == object_uid);
if (rule->mbr_object.mbi_flags & MBI_NEGATED)
match = !match;
if (!match)
return (0);
}
if (rule->mbr_object.mbi_flags & MBI_GID_DEFINED) {
match = (rule->mbr_object.mbi_gid == object_gid);
if (rule->mbr_object.mbi_flags & MBI_NEGATED)
match = !match;
if (!match)
return (0);
}
/*
* Is the access permitted?
*/
if ((rule->mbr_mode & acc_mode) != acc_mode) {
if (mac_bsdextended_debugging)
printf("mac_bsdextended: %d:%d request %d on %d:%d"
" fails\n", cred->cr_ruid, cred->cr_rgid,
acc_mode, object_uid, object_gid);
return (EACCES);
}
return (0);
}
static int
mac_bsdextended_check(struct ucred *cred, uid_t object_uid, gid_t object_gid,
mode_t acc_mode)
{
int error, i;
for (i = 0; i < rule_slots; i++) {
if (rules[i] == NULL)
continue;
error = mac_bsdextended_rulecheck(rules[i], cred, object_uid,
object_gid, acc_mode);
if (error)
return (error);
}
return (0);
}
static int
mac_bsdextended_check_vnode_access(struct ucred *cred, struct vnode *vp,
struct label *label, mode_t flags)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, flags));
}
static int
mac_bsdextended_check_vnode_chdir(struct ucred *cred, struct vnode *dvp,
struct label *dlabel)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(dvp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VEXEC));
}
static int
mac_bsdextended_check_vnode_chroot(struct ucred *cred, struct vnode *dvp,
struct label *dlabel)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(dvp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VEXEC));
}
static int
mac_bsdextended_check_create_vnode(struct ucred *cred, struct vnode *dvp,
struct label *dlabel, struct componentname *cnp, struct vattr *vap)
{
struct vattr dvap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(dvp, &dvap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, dvap.va_uid, dvap.va_gid, VWRITE));
}
static int
mac_bsdextended_check_vnode_delete(struct ucred *cred, struct vnode *dvp,
struct label *dlabel, struct vnode *vp, struct label *label,
struct componentname *cnp)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(dvp, &vap, cred, curthread);
if (error)
return (error);
error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VWRITE);
if (error)
return (error);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VWRITE));
}
static int
mac_bsdextended_check_vnode_deleteacl(struct ucred *cred, struct vnode *vp,
struct label *label, acl_type_t type)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VADMIN));
}
static int
mac_bsdextended_check_vnode_exec(struct ucred *cred, struct vnode *vp,
struct label *label)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
VREAD|VEXEC));
}
static int
mac_bsdextended_check_vnode_getacl(struct ucred *cred, struct vnode *vp,
struct label *label, acl_type_t type)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VSTAT));
}
static int
mac_bsdextended_check_vnode_getextattr(struct ucred *cred, struct vnode *vp,
struct label *label, int attrnamespace, const char *name, struct uio *uio)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VREAD));
}
static int
mac_bsdextended_check_vnode_lookup(struct ucred *cred, struct vnode *dvp,
struct label *dlabel, struct componentname *cnp)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(dvp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VEXEC));
}
static int
mac_bsdextended_check_vnode_open(struct ucred *cred, struct vnode *vp,
struct label *filelabel, mode_t acc_mode)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, acc_mode));
}
static int
mac_bsdextended_check_vnode_readdir(struct ucred *cred, struct vnode *dvp,
struct label *dlabel)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(dvp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VREAD));
}
static int
mac_bsdextended_check_vnode_readdlink(struct ucred *cred, struct vnode *vp,
struct label *label)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VREAD));
}
static int
mac_bsdextended_check_vnode_rename_from(struct ucred *cred, struct vnode *dvp,
struct label *dlabel, struct vnode *vp, struct label *label,
struct componentname *cnp)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(dvp, &vap, cred, curthread);
if (error)
return (error);
error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VWRITE);
if (error)
return (error);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VWRITE);
return (error);
}
static int
mac_bsdextended_check_vnode_rename_to(struct ucred *cred, struct vnode *dvp,
struct label *dlabel, struct vnode *vp, struct label *label, int samedir,
struct componentname *cnp)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(dvp, &vap, cred, curthread);
if (error)
return (error);
error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VWRITE);
if (error)
return (error);
if (vp != NULL) {
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
VWRITE);
}
return (error);
}
static int
mac_bsdextended_check_vnode_revoke(struct ucred *cred, struct vnode *vp,
struct label *label)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VADMIN));
}
static int
mac_bsdextended_check_setacl_vnode(struct ucred *cred, struct vnode *vp,
struct label *label, acl_type_t type, struct acl *acl)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VADMIN));
}
static int
mac_bsdextended_check_vnode_setextattr(struct ucred *cred, struct vnode *vp,
struct label *label, int attrnamespace, const char *name, struct uio *uio)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VWRITE));
}
static int
mac_bsdextended_check_vnode_setflags(struct ucred *cred, struct vnode *vp,
struct label *label, u_long flags)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VADMIN));
}
static int
mac_bsdextended_check_vnode_setmode(struct ucred *cred, struct vnode *vp,
struct label *label, mode_t mode)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VADMIN));
}
static int
mac_bsdextended_check_vnode_setowner(struct ucred *cred, struct vnode *vp,
struct label *label, uid_t uid, gid_t gid)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VADMIN));
}
static int
mac_bsdextended_check_vnode_setutimes(struct ucred *cred, struct vnode *vp,
struct label *label, struct timespec atime, struct timespec utime)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, VADMIN));
}
static int
mac_bsdextended_check_vnode_stat(struct ucred *active_cred,
struct ucred *file_cred, struct vnode *vp, struct label *label)
{
struct vattr vap;
int error;
if (!mac_bsdextended_enabled)
return (0);
error = VOP_GETATTR(vp, &vap, active_cred, curthread);
if (error)
return (error);
return (mac_bsdextended_check(active_cred, vap.va_uid, vap.va_gid,
VSTAT));
}
static struct mac_policy_op_entry mac_bsdextended_ops[] =
{
{ MAC_DESTROY,
(macop_t)mac_bsdextended_destroy },
{ MAC_INIT,
(macop_t)mac_bsdextended_init },
{ MAC_CHECK_VNODE_ACCESS,
(macop_t)mac_bsdextended_check_vnode_access },
{ MAC_CHECK_VNODE_CHDIR,
(macop_t)mac_bsdextended_check_vnode_chdir },
{ MAC_CHECK_VNODE_CHROOT,
(macop_t)mac_bsdextended_check_vnode_chroot },
{ MAC_CHECK_VNODE_CREATE,
(macop_t)mac_bsdextended_check_create_vnode },
{ MAC_CHECK_VNODE_DELETE,
(macop_t)mac_bsdextended_check_vnode_delete },
{ MAC_CHECK_VNODE_DELETEACL,
(macop_t)mac_bsdextended_check_vnode_deleteacl },
{ MAC_CHECK_VNODE_EXEC,
(macop_t)mac_bsdextended_check_vnode_exec },
{ MAC_CHECK_VNODE_GETACL,
(macop_t)mac_bsdextended_check_vnode_getacl },
{ MAC_CHECK_VNODE_GETEXTATTR,
(macop_t)mac_bsdextended_check_vnode_getextattr },
{ MAC_CHECK_VNODE_LOOKUP,
(macop_t)mac_bsdextended_check_vnode_lookup },
{ MAC_CHECK_VNODE_OPEN,
(macop_t)mac_bsdextended_check_vnode_open },
{ MAC_CHECK_VNODE_READDIR,
(macop_t)mac_bsdextended_check_vnode_readdir },
{ MAC_CHECK_VNODE_READLINK,
(macop_t)mac_bsdextended_check_vnode_readdlink },
{ MAC_CHECK_VNODE_RENAME_FROM,
(macop_t)mac_bsdextended_check_vnode_rename_from },
{ MAC_CHECK_VNODE_RENAME_TO,
(macop_t)mac_bsdextended_check_vnode_rename_to },
{ MAC_CHECK_VNODE_REVOKE,
(macop_t)mac_bsdextended_check_vnode_revoke },
{ MAC_CHECK_VNODE_SETACL,
(macop_t)mac_bsdextended_check_setacl_vnode },
{ MAC_CHECK_VNODE_SETEXTATTR,
(macop_t)mac_bsdextended_check_vnode_setextattr },
{ MAC_CHECK_VNODE_SETFLAGS,
(macop_t)mac_bsdextended_check_vnode_setflags },
{ MAC_CHECK_VNODE_SETMODE,
(macop_t)mac_bsdextended_check_vnode_setmode },
{ MAC_CHECK_VNODE_SETOWNER,
(macop_t)mac_bsdextended_check_vnode_setowner },
{ MAC_CHECK_VNODE_SETUTIMES,
(macop_t)mac_bsdextended_check_vnode_setutimes },
{ MAC_CHECK_VNODE_STAT,
(macop_t)mac_bsdextended_check_vnode_stat },
{ MAC_OP_LAST, NULL }
};
MAC_POLICY_SET(mac_bsdextended_ops, trustedbsd_mac_bsdextended,
"TrustedBSD MAC/BSD Extended", MPC_LOADTIME_FLAG_UNLOADOK, NULL);