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Break contents of kern_mac.c out into two files following a repo-copy:

Browse Source 
mac_framework.c   Contains basic MAC Framework functions, policy
                  registration, sysinits, etc.

mac_syscalls.c    Contains implementations of various MAC system calls,
                  including ENOSYS stubs when compiling without options
                  MAC.

Obtained from:	TrustedBSD Project
This commit is contained in:
Robert Watson 2006-12-28 20:52:02 +00:00
parent cd457d4e39
commit 224a974b9b
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=165590
4 changed files with 2 additions and 2503 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
sys/conf/files
View File

@ -1343,7 +1343,6 @@ kern/kern_ktrace.c standard
kern/kern_linker.c standard
kern/kern_lock.c standard
kern/kern_lockf.c standard
kern/kern_mac.c standard
kern/kern_malloc.c standard
kern/kern_mbuf.c standard
kern/kern_mib.c standard
@ -1937,6 +1936,7 @@ security/audit/audit_pipe.c optional audit
security/audit/audit_syscalls.c standard
security/audit/audit_trigger.c optional audit
security/audit/audit_worker.c optional audit
security/mac/mac_framework.c optional mac
security/mac/mac_inet.c optional mac inet
security/mac/mac_label.c optional mac
security/mac/mac_net.c optional mac
@ -1945,6 +1945,7 @@ security/mac/mac_posix_sem.c optional mac
security/mac/mac_priv.c optional mac
security/mac/mac_process.c optional mac
security/mac/mac_socket.c optional mac
security/mac/mac_syscalls.c standard
security/mac/mac_system.c optional mac
security/mac/mac_sysv_msg.c optional mac
security/mac/mac_sysv_sem.c optional mac

1293
sys/kern/kern_mac.c
View File

File diff suppressed because it is too large Load Diff

672
sys/security/mac/mac_framework.c
View File

@ -65,8 +65,6 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/condvar.h>
#include <sys/extattr.h>
@ -109,8 +107,6 @@ __FBSDID("$FreeBSD$");
#include <security/mac/mac_internal.h>
#include <security/mac/mac_policy.h>
#ifdef MAC
/*
* Root sysctl node for all MAC and MAC policy controls.
*/
@ -621,673 +617,5 @@ mac_check_structmac_consistent(struct mac *mac)
return (0);
}
/*
* MPSAFE
*/
int
__mac_get_pid(struct thread *td, struct __mac_get_pid_args *uap)
{
char *elements, *buffer;
struct mac mac;
struct proc *tproc;
struct ucred *tcred;
int error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
tproc = pfind(uap->pid);
if (tproc == NULL)
return (ESRCH);
tcred = NULL; /* Satisfy gcc. */
error = p_cansee(td, tproc);
if (error == 0)
tcred = crhold(tproc->p_ucred);
PROC_UNLOCK(tproc);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
crfree(tcred);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
error = mac_externalize_cred_label(tcred->cr_label, elements,
buffer, mac.m_buflen);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
crfree(tcred);
return (error);
}
/*
* MPSAFE
*/
int
__mac_get_proc(struct thread *td, struct __mac_get_proc_args *uap)
{
char *elements, *buffer;
struct mac mac;
int error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
error = mac_externalize_cred_label(td->td_ucred->cr_label,
elements, buffer, mac.m_buflen);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
/*
* MPSAFE
*/
int
__mac_set_proc(struct thread *td, struct __mac_set_proc_args *uap)
{
struct ucred *newcred, *oldcred;
struct label *intlabel;
struct proc *p;
struct mac mac;
char *buffer;
int error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
intlabel = mac_cred_label_alloc();
error = mac_internalize_cred_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error)
goto out;
newcred = crget();
p = td->td_proc;
PROC_LOCK(p);
oldcred = p->p_ucred;
error = mac_check_cred_relabel(oldcred, intlabel);
if (error) {
PROC_UNLOCK(p);
crfree(newcred);
goto out;
}
setsugid(p);
crcopy(newcred, oldcred);
mac_relabel_cred(newcred, intlabel);
p->p_ucred = newcred;
/*
* Grab additional reference for use while revoking mmaps, prior to
* releasing the proc lock and sharing the cred.
*/
crhold(newcred);
PROC_UNLOCK(p);
mac_cred_mmapped_drop_perms(td, newcred);
crfree(newcred); /* Free revocation reference. */
crfree(oldcred);
out:
mac_cred_label_free(intlabel);
return (error);
}
/*
* MPSAFE
*/
int
__mac_get_fd(struct thread *td, struct __mac_get_fd_args *uap)
{
char *elements, *buffer;
struct label *intlabel;
struct file *fp;
struct mac mac;
struct vnode *vp;
struct pipe *pipe;
struct socket *so;
short label_type;
int vfslocked, error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
error = fget(td, uap->fd, &fp);
if (error)
goto out;
label_type = fp->f_type;
switch (fp->f_type) {
case DTYPE_FIFO:
case DTYPE_VNODE:
vp = fp->f_vnode;
intlabel = mac_vnode_label_alloc();
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
mac_copy_vnode_label(vp->v_label, intlabel);
VOP_UNLOCK(vp, 0, td);
VFS_UNLOCK_GIANT(vfslocked);
error = mac_externalize_vnode_label(intlabel, elements,
buffer, mac.m_buflen);
mac_vnode_label_free(intlabel);
break;
case DTYPE_PIPE:
pipe = fp->f_data;
intlabel = mac_pipe_label_alloc();
PIPE_LOCK(pipe);
mac_copy_pipe_label(pipe->pipe_pair->pp_label, intlabel);
PIPE_UNLOCK(pipe);
error = mac_externalize_pipe_label(intlabel, elements,
buffer, mac.m_buflen);
mac_pipe_label_free(intlabel);
break;
case DTYPE_SOCKET:
so = fp->f_data;
intlabel = mac_socket_label_alloc(M_WAITOK);
NET_LOCK_GIANT();
SOCK_LOCK(so);
mac_copy_socket_label(so->so_label, intlabel);
SOCK_UNLOCK(so);
NET_UNLOCK_GIANT();
error = mac_externalize_socket_label(intlabel, elements,
buffer, mac.m_buflen);
mac_socket_label_free(intlabel);
break;
default:
error = EINVAL;
}
fdrop(fp, td);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
out:
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
/*
* MPSAFE
*/
int
__mac_get_file(struct thread *td, struct __mac_get_file_args *uap)
{
char *elements, *buffer;
struct nameidata nd;
struct label *intlabel;
struct mac mac;
int vfslocked, error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
NDINIT(&nd, LOOKUP, MPSAFE | LOCKLEAF | FOLLOW, UIO_USERSPACE,
uap->path_p, td);
error = namei(&nd);
if (error)
goto out;
intlabel = mac_vnode_label_alloc();
vfslocked = NDHASGIANT(&nd);
mac_copy_vnode_label(nd.ni_vp->v_label, intlabel);
error = mac_externalize_vnode_label(intlabel, elements, buffer,
mac.m_buflen);
NDFREE(&nd, 0);
VFS_UNLOCK_GIANT(vfslocked);
mac_vnode_label_free(intlabel);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
out:
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
/*
* MPSAFE
*/
int
__mac_get_link(struct thread *td, struct __mac_get_link_args *uap)
{
char *elements, *buffer;
struct nameidata nd;
struct label *intlabel;
struct mac mac;
int vfslocked, error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
NDINIT(&nd, LOOKUP, MPSAFE | LOCKLEAF | NOFOLLOW, UIO_USERSPACE,
uap->path_p, td);
error = namei(&nd);
if (error)
goto out;
intlabel = mac_vnode_label_alloc();
vfslocked = NDHASGIANT(&nd);
mac_copy_vnode_label(nd.ni_vp->v_label, intlabel);
error = mac_externalize_vnode_label(intlabel, elements, buffer,
mac.m_buflen);
NDFREE(&nd, 0);
VFS_UNLOCK_GIANT(vfslocked);
mac_vnode_label_free(intlabel);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
out:
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
/*
* MPSAFE
*/
int
__mac_set_fd(struct thread *td, struct __mac_set_fd_args *uap)
{
struct label *intlabel;
struct pipe *pipe;
struct socket *so;
struct file *fp;
struct mount *mp;
struct vnode *vp;
struct mac mac;
char *buffer;
int error, vfslocked;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
error = fget(td, uap->fd, &fp);
if (error)
goto out;
switch (fp->f_type) {
case DTYPE_FIFO:
case DTYPE_VNODE:
intlabel = mac_vnode_label_alloc();
error = mac_internalize_vnode_label(intlabel, buffer);
if (error) {
mac_vnode_label_free(intlabel);
break;
}
vp = fp->f_vnode;
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
if (error != 0) {
VFS_UNLOCK_GIANT(vfslocked);
mac_vnode_label_free(intlabel);
break;
}
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
error = vn_setlabel(vp, intlabel, td->td_ucred);
VOP_UNLOCK(vp, 0, td);
vn_finished_write(mp);
VFS_UNLOCK_GIANT(vfslocked);
mac_vnode_label_free(intlabel);
break;
case DTYPE_PIPE:
intlabel = mac_pipe_label_alloc();
error = mac_internalize_pipe_label(intlabel, buffer);
if (error == 0) {
pipe = fp->f_data;
PIPE_LOCK(pipe);
error = mac_pipe_label_set(td->td_ucred,
pipe->pipe_pair, intlabel);
PIPE_UNLOCK(pipe);
}
mac_pipe_label_free(intlabel);
break;
case DTYPE_SOCKET:
intlabel = mac_socket_label_alloc(M_WAITOK);
error = mac_internalize_socket_label(intlabel, buffer);
if (error == 0) {
so = fp->f_data;
NET_LOCK_GIANT();
error = mac_socket_label_set(td->td_ucred, so,
intlabel);
NET_UNLOCK_GIANT();
}
mac_socket_label_free(intlabel);
break;
default:
error = EINVAL;
}
fdrop(fp, td);
out:
free(buffer, M_MACTEMP);
return (error);
}
/*
* MPSAFE
*/
int
__mac_set_file(struct thread *td, struct __mac_set_file_args *uap)
{
struct label *intlabel;
struct nameidata nd;
struct mount *mp;
struct mac mac;
char *buffer;
int vfslocked, error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
intlabel = mac_vnode_label_alloc();
error = mac_internalize_vnode_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error)
goto out;
NDINIT(&nd, LOOKUP, MPSAFE | LOCKLEAF | FOLLOW, UIO_USERSPACE,
uap->path_p, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH);
if (error == 0) {
error = vn_setlabel(nd.ni_vp, intlabel,
td->td_ucred);
vn_finished_write(mp);
}
}
NDFREE(&nd, 0);
VFS_UNLOCK_GIANT(vfslocked);
out:
mac_vnode_label_free(intlabel);
return (error);
}
/*
* MPSAFE
*/
int
__mac_set_link(struct thread *td, struct __mac_set_link_args *uap)
{
struct label *intlabel;
struct nameidata nd;
struct mount *mp;
struct mac mac;
char *buffer;
int vfslocked, error;
error = copyin(uap->mac_p, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
intlabel = mac_vnode_label_alloc();
error = mac_internalize_vnode_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error)
goto out;
NDINIT(&nd, LOOKUP, MPSAFE | LOCKLEAF | NOFOLLOW, UIO_USERSPACE,
uap->path_p, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH);
if (error == 0) {
error = vn_setlabel(nd.ni_vp, intlabel,
td->td_ucred);
vn_finished_write(mp);
}
}
NDFREE(&nd, 0);
VFS_UNLOCK_GIANT(vfslocked);
out:
mac_vnode_label_free(intlabel);
return (error);
}
/*
* MPSAFE
*/
int
mac_syscall(struct thread *td, struct mac_syscall_args *uap)
{
struct mac_policy_conf *mpc;
char target[MAC_MAX_POLICY_NAME];
int entrycount, error;
error = copyinstr(uap->policy, target, sizeof(target), NULL);
if (error)
return (error);
error = ENOSYS;
LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {
if (strcmp(mpc->mpc_name, target) == 0 &&
mpc->mpc_ops->mpo_syscall != NULL) {
error = mpc->mpc_ops->mpo_syscall(td,
uap->call, uap->arg);
goto out;
}
}
if ((entrycount = mac_policy_list_conditional_busy()) != 0) {
LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {
if (strcmp(mpc->mpc_name, target) == 0 &&
mpc->mpc_ops->mpo_syscall != NULL) {
error = mpc->mpc_ops->mpo_syscall(td,
uap->call, uap->arg);
break;
}
}
mac_policy_list_unbusy();
}
out:
return (error);
}
SYSINIT(mac, SI_SUB_MAC, SI_ORDER_FIRST, mac_init, NULL);
SYSINIT(mac_late, SI_SUB_MAC_LATE, SI_ORDER_FIRST, mac_late_init, NULL);
#else /* !MAC */
int
__mac_get_pid(struct thread *td, struct __mac_get_pid_args *uap)
{
return (ENOSYS);
}
int
__mac_get_proc(struct thread *td, struct __mac_get_proc_args *uap)
{
return (ENOSYS);
}
int
__mac_set_proc(struct thread *td, struct __mac_set_proc_args *uap)
{
return (ENOSYS);
}
int
__mac_get_fd(struct thread *td, struct __mac_get_fd_args *uap)
{
return (ENOSYS);
}
int
__mac_get_file(struct thread *td, struct __mac_get_file_args *uap)
{
return (ENOSYS);
}
int
__mac_get_link(struct thread *td, struct __mac_get_link_args *uap)
{
return (ENOSYS);
}
int
__mac_set_fd(struct thread *td, struct __mac_set_fd_args *uap)
{
return (ENOSYS);
}
int
__mac_set_file(struct thread *td, struct __mac_set_file_args *uap)
{
return (ENOSYS);
}
int
__mac_set_link(struct thread *td, struct __mac_set_link_args *uap)
{
return (ENOSYS);
}
int
mac_syscall(struct thread *td, struct mac_syscall_args *uap)
{
return (ENOSYS);
}
#endif /* !MAC */

537
sys/security/mac/mac_syscalls.c
View File

@ -38,30 +38,6 @@
* SUCH DAMAGE.
*/
/*-
* Framework for extensible kernel access control. This file contains core
* kernel infrastructure for the TrustedBSD MAC Framework, including policy
* registration, versioning, locking, error composition operator, and system
* calls.
*
* The MAC Framework implements three programming interfaces:
*
* - The kernel MAC interface, defined in mac_framework.h, and invoked
* throughout the kernel to request security decisions, notify of security
* related events, etc.
*
* - The MAC policy module interface, defined in mac_policy.h, which is
* implemented by MAC policy modules and invoked by the MAC Framework to
* forward kernel security requests and notifications to policy modules.
*
* - The user MAC API, defined in mac.h, which allows user programs to query
* and set label state on objects.
*
* The majority of the MAC Framework implementation may be found in
* src/sys/security/mac. Sample policy modules may be found in
* src/sys/security/mac_*.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
@ -111,516 +87,6 @@ __FBSDID("$FreeBSD$");
#ifdef MAC
/*
* Root sysctl node for all MAC and MAC policy controls.
*/
SYSCTL_NODE(_security, OID_AUTO, mac, CTLFLAG_RW, 0,
"TrustedBSD MAC policy controls");
/*
* Declare that the kernel provides MAC support, version 3 (FreeBSD 7.x).
* This permits modules to refuse to be loaded if the necessary support isn't
* present, even if it's pre-boot.
*/
#define MAC_VERSION 3
static unsigned int mac_version = MAC_VERSION;
MODULE_VERSION(kernel_mac_support, MAC_VERSION);
SYSCTL_UINT(_security_mac, OID_AUTO, version, CTLFLAG_RD, &mac_version, 0,
"");
/*
* Labels consist of a indexed set of "slots", which are allocated policies
* as required. The MAC Framework maintains a bitmask of slots allocated so
* far to prevent reuse. Slots cannot be reused, as the MAC Framework
* guarantees that newly allocated slots in labels will be NULL unless
* otherwise initialized, and because we do not have a mechanism to garbage
* collect slots on policy unload. As labeled policies tend to be statically
* loaded during boot, and not frequently unloaded and reloaded, this is not
* generally an issue.
*/
#if MAC_MAX_SLOTS > 32
#error "MAC_MAX_SLOTS too large"
#endif
static unsigned int mac_max_slots = MAC_MAX_SLOTS;
static unsigned int mac_slot_offsets_free = (1 << MAC_MAX_SLOTS) - 1;
SYSCTL_UINT(_security_mac, OID_AUTO, max_slots, CTLFLAG_RD, &mac_max_slots,
0, "");
/*
* Has the kernel started generating labeled objects yet? All read/write
* access to this variable is serialized during the boot process. Following
* the end of serialization, we don't update this flag; no locking.
*/
int mac_late = 0;
/*
* Flag to indicate whether or not we should allocate label storage for new
* mbufs. Since most dynamic policies we currently work with don't rely on
* mbuf labeling, try to avoid paying the cost of mtag allocation unless
* specifically notified of interest. One result of this is that if a
* dynamically loaded policy requests mbuf labels, it must be able to deal
* with a NULL label being returned on any mbufs that were already in flight
* when the policy was loaded. Since the policy already has to deal with
* uninitialized labels, this probably won't be a problem. Note: currently
* no locking. Will this be a problem?
*
* In the future, we may want to allow objects to request labeling on a per-
* object type basis, rather than globally for all objects.
*/
#ifndef MAC_ALWAYS_LABEL_MBUF
int mac_labelmbufs = 0;
#endif
static int mac_policy_register(struct mac_policy_conf *mpc);
static int mac_policy_unregister(struct mac_policy_conf *mpc);
MALLOC_DEFINE(M_MACTEMP, "mactemp", "MAC temporary label storage");
/*
* mac_static_policy_list holds a list of policy modules that are not loaded
* while the system is "live", and cannot be unloaded. These policies can be
* invoked without holding the busy count.
*
* mac_policy_list stores the list of dynamic policies. A busy count is
* maintained for the list, stored in mac_policy_busy. The busy count is
* protected by mac_policy_mtx; the list may be modified only while the busy
* count is 0, requiring that the lock be held to prevent new references to
* the list from being acquired. For almost all operations, incrementing the
* busy count is sufficient to guarantee consistency, as the list cannot be
* modified while the busy count is elevated. For a few special operations
* involving a change to the list of active policies, the mtx itself must be
* held. A condition variable, mac_policy_cv, is used to signal potential
* exclusive consumers that they should try to acquire the lock if a first
* attempt at exclusive access fails.
*
* This design intentionally avoids fairness, and may starve attempts to
* acquire an exclusive lock on a busy system. This is required because we
* do not ever want acquiring a read reference to perform an unbounded length
* sleep. Read references are acquired in ithreads, network isrs, etc, and
* any unbounded blocking could lead quickly to deadlock.
*
* Another reason for never blocking on read references is that the MAC
* Framework may recurse: if a policy calls a VOP, for example, this might
* lead to vnode life cycle operations (such as init/destroy).
*
* If the kernel option MAC_STATIC has been compiled in, all locking becomes
* a no-op, and the global list of policies is not allowed to change after
* early boot.
*/
#ifndef MAC_STATIC
static struct mtx mac_policy_mtx;
static struct cv mac_policy_cv;
static int mac_policy_count;
#endif
struct mac_policy_list_head mac_policy_list;
struct mac_policy_list_head mac_static_policy_list;
/*
* We manually invoke WITNESS_WARN() to allow Witness to generate warnings
* even if we don't end up ever triggering the wait at run-time. The
* consumer of the exclusive interface must not hold any locks (other than
* potentially Giant) since we may sleep for long (potentially indefinite)
* periods of time waiting for the framework to become quiescent so that a
* policy list change may be made.
*/
void
mac_policy_grab_exclusive(void)
{
#ifndef MAC_STATIC
if (!mac_late)
return;
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"mac_policy_grab_exclusive() at %s:%d", __FILE__, __LINE__);
mtx_lock(&mac_policy_mtx);
while (mac_policy_count != 0)
cv_wait(&mac_policy_cv, &mac_policy_mtx);
#endif
}
void
mac_policy_assert_exclusive(void)
{
#ifndef MAC_STATIC
if (!mac_late)
return;
mtx_assert(&mac_policy_mtx, MA_OWNED);
KASSERT(mac_policy_count == 0,
("mac_policy_assert_exclusive(): not exclusive"));
#endif
}
void
mac_policy_release_exclusive(void)
{
#ifndef MAC_STATIC
if (!mac_late)
return;
KASSERT(mac_policy_count == 0,
("mac_policy_release_exclusive(): not exclusive"));
mtx_unlock(&mac_policy_mtx);
cv_signal(&mac_policy_cv);
#endif
}
void
mac_policy_list_busy(void)
{
#ifndef MAC_STATIC
if (!mac_late)
return;
mtx_lock(&mac_policy_mtx);
mac_policy_count++;
mtx_unlock(&mac_policy_mtx);
#endif
}
int
mac_policy_list_conditional_busy(void)
{
#ifndef MAC_STATIC
int ret;
if (!mac_late)
return (1);
mtx_lock(&mac_policy_mtx);
if (!LIST_EMPTY(&mac_policy_list)) {
mac_policy_count++;
ret = 1;
} else
ret = 0;
mtx_unlock(&mac_policy_mtx);
return (ret);
#else
if (!mac_late)
return (1);
return (1);
#endif
}
void
mac_policy_list_unbusy(void)
{
#ifndef MAC_STATIC
if (!mac_late)
return;
mtx_lock(&mac_policy_mtx);
mac_policy_count--;
KASSERT(mac_policy_count >= 0, ("MAC_POLICY_LIST_LOCK"));
if (mac_policy_count == 0)
cv_signal(&mac_policy_cv);
mtx_unlock(&mac_policy_mtx);
#endif
}
/*
* Initialize the MAC subsystem, including appropriate SMP locks.
*/
static void
mac_init(void)
{
LIST_INIT(&mac_static_policy_list);
LIST_INIT(&mac_policy_list);
mac_labelzone_init();
#ifndef MAC_STATIC
mtx_init(&mac_policy_mtx, "mac_policy_mtx", NULL, MTX_DEF);
cv_init(&mac_policy_cv, "mac_policy_cv");
#endif
}
/*
* For the purposes of modules that want to know if they were loaded "early",
* set the mac_late flag once we've processed modules either linked into the
* kernel, or loaded before the kernel startup.
*/
static void
mac_late_init(void)
{
mac_late = 1;
}
/*
* After the policy list has changed, walk the list to update any global
* flags. Currently, we support only one flag, and it's conditionally
* defined; as a result, the entire function is conditional. Eventually, the
* #else case might also iterate across the policies.
*/
static void
mac_policy_updateflags(void)
{
#ifndef MAC_ALWAYS_LABEL_MBUF
struct mac_policy_conf *tmpc;
int labelmbufs;
mac_policy_assert_exclusive();
labelmbufs = 0;
LIST_FOREACH(tmpc, &mac_static_policy_list, mpc_list) {
if (tmpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_LABELMBUFS)
labelmbufs++;
}
LIST_FOREACH(tmpc, &mac_policy_list, mpc_list) {
if (tmpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_LABELMBUFS)
labelmbufs++;
}
mac_labelmbufs = (labelmbufs != 0);
#endif
}
/*
* Allow MAC policy modules to register during boot, etc.
*/
int
mac_policy_modevent(module_t mod, int type, void *data)
{
struct mac_policy_conf *mpc;
int error;
error = 0;
mpc = (struct mac_policy_conf *) data;
#ifdef MAC_STATIC
if (mac_late) {
printf("mac_policy_modevent: MAC_STATIC and late\n");
return (EBUSY);
}
#endif
switch (type) {
case MOD_LOAD:
if (mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_NOTLATE &&
mac_late) {
printf("mac_policy_modevent: can't load %s policy "
"after booting\n", mpc->mpc_name);
error = EBUSY;
break;
}
error = mac_policy_register(mpc);
break;
case MOD_UNLOAD:
/* Don't unregister the module if it was never registered. */
if ((mpc->mpc_runtime_flags & MPC_RUNTIME_FLAG_REGISTERED)
!= 0)
error = mac_policy_unregister(mpc);
else
error = 0;
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static int
mac_policy_register(struct mac_policy_conf *mpc)
{
struct mac_policy_conf *tmpc;
int error, slot, static_entry;
error = 0;
/*
* We don't technically need exclusive access while !mac_late, but
* hold it for assertion consistency.
*/
mac_policy_grab_exclusive();
/*
* If the module can potentially be unloaded, or we're loading late,
* we have to stick it in the non-static list and pay an extra
* performance overhead. Otherwise, we can pay a light locking cost
* and stick it in the static list.
*/
static_entry = (!mac_late &&
!(mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_UNLOADOK));
if (static_entry) {
LIST_FOREACH(tmpc, &mac_static_policy_list, mpc_list) {
if (strcmp(tmpc->mpc_name, mpc->mpc_name) == 0) {
error = EEXIST;
goto out;
}
}
} else {
LIST_FOREACH(tmpc, &mac_policy_list, mpc_list) {
if (strcmp(tmpc->mpc_name, mpc->mpc_name) == 0) {
error = EEXIST;
goto out;
}
}
}
if (mpc->mpc_field_off != NULL) {
slot = ffs(mac_slot_offsets_free);
if (slot == 0) {
error = ENOMEM;
goto out;
}
slot--;
mac_slot_offsets_free &= ~(1 << slot);
*mpc->mpc_field_off = slot;
}
mpc->mpc_runtime_flags |= MPC_RUNTIME_FLAG_REGISTERED;
/*
* If we're loading a MAC module after the framework has initialized,
* it has to go into the dynamic list. If we're loading it before
* we've finished initializing, it can go into the static list with
* weaker locker requirements.
*/
if (static_entry)
LIST_INSERT_HEAD(&mac_static_policy_list, mpc, mpc_list);
else
LIST_INSERT_HEAD(&mac_policy_list, mpc, mpc_list);
/*
* Per-policy initialization. Currently, this takes place under the
* exclusive lock, so policies must not sleep in their init method.
* In the future, we may want to separate "init" from "start", with
* "init" occuring without the lock held. Likewise, on tear-down,
* breaking out "stop" from "destroy".
*/
if (mpc->mpc_ops->mpo_init != NULL)
(*(mpc->mpc_ops->mpo_init))(mpc);
mac_policy_updateflags();
printf("Security policy loaded: %s (%s)\n", mpc->mpc_fullname,
mpc->mpc_name);
out:
mac_policy_release_exclusive();
return (error);
}
static int
mac_policy_unregister(struct mac_policy_conf *mpc)
{
/*
* If we fail the load, we may get a request to unload. Check to see
* if we did the run-time registration, and if not, silently succeed.
*/
mac_policy_grab_exclusive();
if ((mpc->mpc_runtime_flags & MPC_RUNTIME_FLAG_REGISTERED) == 0) {
mac_policy_release_exclusive();
return (0);
}
#if 0
/*
* Don't allow unloading modules with private data.
*/
if (mpc->mpc_field_off != NULL) {
MAC_POLICY_LIST_UNLOCK();
return (EBUSY);
}
#endif
/*
* Only allow the unload to proceed if the module is unloadable by
* its own definition.
*/
if ((mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_UNLOADOK) == 0) {
mac_policy_release_exclusive();
return (EBUSY);
}
if (mpc->mpc_ops->mpo_destroy != NULL)
(*(mpc->mpc_ops->mpo_destroy))(mpc);
LIST_REMOVE(mpc, mpc_list);
mpc->mpc_runtime_flags &= ~MPC_RUNTIME_FLAG_REGISTERED;
mac_policy_updateflags();
mac_policy_release_exclusive();
printf("Security policy unload: %s (%s)\n", mpc->mpc_fullname,
mpc->mpc_name);
return (0);
}
/*
* Define an error value precedence, and given two arguments, selects the
* value with the higher precedence.
*/
int
mac_error_select(int error1, int error2)
{
/* Certain decision-making errors take top priority. */
if (error1 == EDEADLK || error2 == EDEADLK)
return (EDEADLK);
/* Invalid arguments should be reported where possible. */
if (error1 == EINVAL || error2 == EINVAL)
return (EINVAL);
/* Precedence goes to "visibility", with both process and file. */
if (error1 == ESRCH || error2 == ESRCH)
return (ESRCH);
if (error1 == ENOENT || error2 == ENOENT)
return (ENOENT);
/* Precedence goes to DAC/MAC protections. */
if (error1 == EACCES || error2 == EACCES)
return (EACCES);
/* Precedence goes to privilege. */
if (error1 == EPERM || error2 == EPERM)
return (EPERM);
/* Precedence goes to error over success; otherwise, arbitrary. */
if (error1 != 0)
return (error1);
return (error2);
}
void
mac_init_label(struct label *label)
{
bzero(label, sizeof(*label));
label->l_flags = MAC_FLAG_INITIALIZED;
}
void
mac_destroy_label(struct label *label)
{
KASSERT(label->l_flags & MAC_FLAG_INITIALIZED,
("destroying uninitialized label"));
bzero(label, sizeof(*label));
/* implicit: label->l_flags &= ~MAC_FLAG_INITIALIZED; */
}
int
mac_check_structmac_consistent(struct mac *mac)
{
if (mac->m_buflen < 0 ||
mac->m_buflen > MAC_MAX_LABEL_BUF_LEN)
return (EINVAL);
return (0);
}
/*
* MPSAFE
*/
@ -1215,9 +681,6 @@ mac_syscall(struct thread *td, struct mac_syscall_args *uap)
return (error);
}
SYSINIT(mac, SI_SUB_MAC, SI_ORDER_FIRST, mac_init, NULL);
SYSINIT(mac_late, SI_SUB_MAC_LATE, SI_ORDER_FIRST, mac_late_init, NULL);
#else /* !MAC */
int