freebsd-dev/sys/security/mac_bsdextended/mac_bsdextended.c
Robert Watson 939b97cba6 Update policy modules for changes in arguments associated with support
for label access on the interpreter, not just the shell script.  No
policies currently present in the system rely on the new labels.
2002-11-05 17:52:42 +00:00

750 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 Network
* Associates Laboratories, 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.
*
* 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, int 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,
int 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, int 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_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 image_params *imgp)
{
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_link(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);
if (error)
return (error);
return (0);
}
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, int 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_ops mac_bsdextended_ops =
{
.mpo_destroy = mac_bsdextended_destroy,
.mpo_init = mac_bsdextended_init,
.mpo_check_vnode_access = mac_bsdextended_check_vnode_access,
.mpo_check_vnode_chdir = mac_bsdextended_check_vnode_chdir,
.mpo_check_vnode_chroot = mac_bsdextended_check_vnode_chroot,
.mpo_check_vnode_create = mac_bsdextended_check_create_vnode,
.mpo_check_vnode_delete = mac_bsdextended_check_vnode_delete,
.mpo_check_vnode_deleteacl = mac_bsdextended_check_vnode_deleteacl,
.mpo_check_vnode_exec = mac_bsdextended_check_vnode_exec,
.mpo_check_vnode_getacl = mac_bsdextended_check_vnode_getacl,
.mpo_check_vnode_getextattr = mac_bsdextended_check_vnode_getextattr,
.mpo_check_vnode_link = mac_bsdextended_check_vnode_link,
.mpo_check_vnode_lookup = mac_bsdextended_check_vnode_lookup,
.mpo_check_vnode_open = mac_bsdextended_check_vnode_open,
.mpo_check_vnode_readdir = mac_bsdextended_check_vnode_readdir,
.mpo_check_vnode_readlink = mac_bsdextended_check_vnode_readdlink,
.mpo_check_vnode_rename_from = mac_bsdextended_check_vnode_rename_from,
.mpo_check_vnode_rename_to = mac_bsdextended_check_vnode_rename_to,
.mpo_check_vnode_revoke = mac_bsdextended_check_vnode_revoke,
.mpo_check_vnode_setacl = mac_bsdextended_check_setacl_vnode,
.mpo_check_vnode_setextattr = mac_bsdextended_check_vnode_setextattr,
.mpo_check_vnode_setflags = mac_bsdextended_check_vnode_setflags,
.mpo_check_vnode_setmode = mac_bsdextended_check_vnode_setmode,
.mpo_check_vnode_setowner = mac_bsdextended_check_vnode_setowner,
.mpo_check_vnode_setutimes = mac_bsdextended_check_vnode_setutimes,
.mpo_check_vnode_stat = mac_bsdextended_check_vnode_stat,
};
MAC_POLICY_SET(&mac_bsdextended_ops, trustedbsd_mac_bsdextended,
"TrustedBSD MAC/BSD Extended", MPC_LOADTIME_FLAG_UNLOADOK, NULL);