freebsd-dev/sys/security/mac/mac_syscalls.c
Brooks Davis d88fe103eb Reduce duplication in __mac_*_(file|link)(2) implementation.
Reviewed by:	rwatson
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14175
2018-02-15 18:57:22 +00:00

662 lines
15 KiB
C

/*-
* Copyright (c) 1999-2002, 2006, 2009 Robert N. M. Watson
* Copyright (c) 2001 Ilmar S. Habibulin
* Copyright (c) 2001-2005 Networks Associates Technology, Inc.
* Copyright (c) 2005-2006 SPARTA, Inc.
* Copyright (c) 2008 Apple Inc.
* All rights reserved.
*
* This software was developed by Robert Watson and Ilmar Habibulin 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.
*
* This software was enhanced by SPARTA ISSO under SPAWAR contract
* N66001-04-C-6019 ("SEFOS").
*
* This software was developed at the University of Cambridge Computer
* Laboratory with support from a grant from Google, Inc.
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/capsicum.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mac.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/socket.h>
#include <sys/pipe.h>
#include <sys/socketvar.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
#include <security/mac/mac_policy.h>
#ifdef MAC
FEATURE(security_mac, "Mandatory Access Control Framework support");
static int kern___mac_get_path(struct thread *td, const char *path_p,
struct mac *mac_p, int follow);
static int kern___mac_set_path(struct thread *td, const char *path_p,
struct mac *mac_p, int follow);
int
sys___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_cred_externalize_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);
}
int
sys___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_cred_externalize_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);
}
int
sys___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;
if (!(mac_labeled & MPC_OBJECT_CRED))
return (EINVAL);
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_cred_internalize_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_cred_check_relabel(oldcred, intlabel);
if (error) {
PROC_UNLOCK(p);
crfree(newcred);
goto out;
}
setsugid(p);
crcopy(newcred, oldcred);
mac_cred_relabel(newcred, intlabel);
proc_set_cred(p, newcred);
PROC_UNLOCK(p);
crfree(oldcred);
mac_proc_vm_revoke(td);
out:
mac_cred_label_free(intlabel);
return (error);
}
int
sys___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;
cap_rights_t rights;
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 = fget(td, uap->fd, cap_rights_init(&rights, CAP_MAC_GET), &fp);
if (error)
goto out;
switch (fp->f_type) {
case DTYPE_FIFO:
case DTYPE_VNODE:
if (!(mac_labeled & MPC_OBJECT_VNODE)) {
error = EINVAL;
goto out_fdrop;
}
vp = fp->f_vnode;
intlabel = mac_vnode_label_alloc();
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
mac_vnode_copy_label(vp->v_label, intlabel);
VOP_UNLOCK(vp, 0);
error = mac_vnode_externalize_label(intlabel, elements,
buffer, mac.m_buflen);
mac_vnode_label_free(intlabel);
break;
case DTYPE_PIPE:
if (!(mac_labeled & MPC_OBJECT_PIPE)) {
error = EINVAL;
goto out_fdrop;
}
pipe = fp->f_data;
intlabel = mac_pipe_label_alloc();
PIPE_LOCK(pipe);
mac_pipe_copy_label(pipe->pipe_pair->pp_label, intlabel);
PIPE_UNLOCK(pipe);
error = mac_pipe_externalize_label(intlabel, elements,
buffer, mac.m_buflen);
mac_pipe_label_free(intlabel);
break;
case DTYPE_SOCKET:
if (!(mac_labeled & MPC_OBJECT_SOCKET)) {
error = EINVAL;
goto out_fdrop;
}
so = fp->f_data;
intlabel = mac_socket_label_alloc(M_WAITOK);
SOCK_LOCK(so);
mac_socket_copy_label(so->so_label, intlabel);
SOCK_UNLOCK(so);
error = mac_socket_externalize_label(intlabel, elements,
buffer, mac.m_buflen);
mac_socket_label_free(intlabel);
break;
default:
error = EINVAL;
}
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
out_fdrop:
fdrop(fp, td);
out:
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
int
sys___mac_get_file(struct thread *td, struct __mac_get_file_args *uap)
{
return (kern___mac_get_path(td, uap->path_p, uap->mac_p, FOLLOW));
}
int
sys___mac_get_link(struct thread *td, struct __mac_get_link_args *uap)
{
return (kern___mac_get_path(td, uap->path_p, uap->mac_p, NOFOLLOW));
}
static int
kern___mac_get_path(struct thread *td, const char *path_p, struct mac *mac_p,
int follow)
{
char *elements, *buffer;
struct nameidata nd;
struct label *intlabel;
struct mac mac;
int error;
if (!(mac_labeled & MPC_OBJECT_VNODE))
return (EINVAL);
error = copyin(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, LOCKLEAF | follow, UIO_USERSPACE, path_p, td);
error = namei(&nd);
if (error)
goto out;
intlabel = mac_vnode_label_alloc();
mac_vnode_copy_label(nd.ni_vp->v_label, intlabel);
error = mac_vnode_externalize_label(intlabel, elements, buffer,
mac.m_buflen);
NDFREE(&nd, 0);
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);
}
int
sys___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;
cap_rights_t rights;
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);
}
error = fget(td, uap->fd, cap_rights_init(&rights, CAP_MAC_SET), &fp);
if (error)
goto out;
switch (fp->f_type) {
case DTYPE_FIFO:
case DTYPE_VNODE:
if (!(mac_labeled & MPC_OBJECT_VNODE)) {
error = EINVAL;
goto out_fdrop;
}
intlabel = mac_vnode_label_alloc();
error = mac_vnode_internalize_label(intlabel, buffer);
if (error) {
mac_vnode_label_free(intlabel);
break;
}
vp = fp->f_vnode;
error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
if (error != 0) {
mac_vnode_label_free(intlabel);
break;
}
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
error = vn_setlabel(vp, intlabel, td->td_ucred);
VOP_UNLOCK(vp, 0);
vn_finished_write(mp);
mac_vnode_label_free(intlabel);
break;
case DTYPE_PIPE:
if (!(mac_labeled & MPC_OBJECT_PIPE)) {
error = EINVAL;
goto out_fdrop;
}
intlabel = mac_pipe_label_alloc();
error = mac_pipe_internalize_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:
if (!(mac_labeled & MPC_OBJECT_SOCKET)) {
error = EINVAL;
goto out_fdrop;
}
intlabel = mac_socket_label_alloc(M_WAITOK);
error = mac_socket_internalize_label(intlabel, buffer);
if (error == 0) {
so = fp->f_data;
error = mac_socket_label_set(td->td_ucred, so,
intlabel);
}
mac_socket_label_free(intlabel);
break;
default:
error = EINVAL;
}
out_fdrop:
fdrop(fp, td);
out:
free(buffer, M_MACTEMP);
return (error);
}
int
sys___mac_set_file(struct thread *td, struct __mac_set_file_args *uap)
{
return (kern___mac_set_path(td, uap->path_p, uap->mac_p, FOLLOW));
}
int
sys___mac_set_link(struct thread *td, struct __mac_set_link_args *uap)
{
return (kern___mac_set_path(td, uap->path_p, uap->mac_p, NOFOLLOW));
}
static int
kern___mac_set_path(struct thread *td, const char *path_p, struct mac *mac_p,
int follow)
{
struct label *intlabel;
struct nameidata nd;
struct mount *mp;
struct mac mac;
char *buffer;
int error;
if (!(mac_labeled & MPC_OBJECT_VNODE))
return (EINVAL);
error = copyin(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_vnode_internalize_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error)
goto out;
NDINIT(&nd, LOOKUP, LOCKLEAF | follow, UIO_USERSPACE, path_p, td);
error = namei(&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);
out:
mac_vnode_label_free(intlabel);
return (error);
}
int
sys_mac_syscall(struct thread *td, struct mac_syscall_args *uap)
{
struct mac_policy_conf *mpc;
char target[MAC_MAX_POLICY_NAME];
int 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 (!LIST_EMPTY(&mac_policy_list)) {
mac_policy_slock_sleep();
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_sunlock_sleep();
}
out:
return (error);
}
#else /* !MAC */
int
sys___mac_get_pid(struct thread *td, struct __mac_get_pid_args *uap)
{
return (ENOSYS);
}
int
sys___mac_get_proc(struct thread *td, struct __mac_get_proc_args *uap)
{
return (ENOSYS);
}
int
sys___mac_set_proc(struct thread *td, struct __mac_set_proc_args *uap)
{
return (ENOSYS);
}
int
sys___mac_get_fd(struct thread *td, struct __mac_get_fd_args *uap)
{
return (ENOSYS);
}
int
sys___mac_get_file(struct thread *td, struct __mac_get_file_args *uap)
{
return (ENOSYS);
}
int
sys___mac_get_link(struct thread *td, struct __mac_get_link_args *uap)
{
return (ENOSYS);
}
int
sys___mac_set_fd(struct thread *td, struct __mac_set_fd_args *uap)
{
return (ENOSYS);
}
int
sys___mac_set_file(struct thread *td, struct __mac_set_file_args *uap)
{
return (ENOSYS);
}
int
sys___mac_set_link(struct thread *td, struct __mac_set_link_args *uap)
{
return (ENOSYS);
}
int
sys_mac_syscall(struct thread *td, struct mac_syscall_args *uap)
{
return (ENOSYS);
}
#endif /* !MAC */