freebsd-dev/sys/kern/vfs_acl.c

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/*-
* Copyright (c) 1999-2006 Robert N. M. Watson
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
*
* 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.
*/
/*
* Developed by the TrustedBSD Project.
*
* ACL system calls and other functions common across different ACL types.
* Type-specific routines go into subr_acl_<type>.c.
*/
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#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/proc.h>
#include <sys/sysent.h>
#include <sys/acl.h>
#include <security/mac/mac_framework.h>
static MALLOC_DEFINE(M_ACL, "acl", "Access Control Lists");
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static int vacl_set_acl(struct thread *td, struct vnode *vp,
acl_type_t type, struct acl *aclp);
static int vacl_get_acl(struct thread *td, struct vnode *vp,
acl_type_t type, struct acl *aclp);
static int vacl_aclcheck(struct thread *td, struct vnode *vp,
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acl_type_t type, struct acl *aclp);
/*
* These calls wrap the real vnode operations, and are called by the syscall
* code once the syscall has converted the path or file descriptor to a vnode
* (unlocked). The aclp pointer is assumed still to point to userland, so
* this should not be consumed within the kernel except by syscall code.
* Other code should directly invoke VOP_{SET,GET}ACL.
*/
/*
* Given a vnode, set its ACL.
*/
static int
vacl_set_acl(struct thread *td, struct vnode *vp, acl_type_t type,
struct acl *aclp)
{
struct acl *inkernelacl;
struct mount *mp;
int error;
inkernelacl = acl_alloc(M_WAITOK);
error = copyin(aclp, inkernelacl, sizeof(struct acl));
if (error)
goto out;
error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
if (error != 0)
goto out;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
#ifdef MAC
error = mac_vnode_check_setacl(td->td_ucred, vp, type, inkernelacl);
if (error != 0)
goto out_unlock;
#endif
error = VOP_SETACL(vp, type, inkernelacl, td->td_ucred, td);
#ifdef MAC
out_unlock:
#endif
VOP_UNLOCK(vp, 0);
vn_finished_write(mp);
out:
acl_free(inkernelacl);
return(error);
}
/*
* Given a vnode, get its ACL.
*/
static int
vacl_get_acl(struct thread *td, struct vnode *vp, acl_type_t type,
struct acl *aclp)
{
struct acl *inkernelacl;
int error;
inkernelacl = acl_alloc(M_WAITOK);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
#ifdef MAC
error = mac_vnode_check_getacl(td->td_ucred, vp, type);
if (error != 0)
goto out;
#endif
error = VOP_GETACL(vp, type, inkernelacl, td->td_ucred, td);
#ifdef MAC
out:
#endif
VOP_UNLOCK(vp, 0);
if (error == 0)
error = copyout(inkernelacl, aclp, sizeof(struct acl));
acl_free(inkernelacl);
return (error);
}
/*
* Given a vnode, delete its ACL.
*/
static int
vacl_delete(struct thread *td, struct vnode *vp, acl_type_t type)
{
struct mount *mp;
int error;
error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
if (error)
return (error);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
#ifdef MAC
error = mac_vnode_check_deleteacl(td->td_ucred, vp, type);
if (error)
goto out;
#endif
error = VOP_SETACL(vp, type, 0, td->td_ucred, td);
#ifdef MAC
out:
#endif
VOP_UNLOCK(vp, 0);
vn_finished_write(mp);
return (error);
}
/*
* Given a vnode, check whether an ACL is appropriate for it
*/
static int
vacl_aclcheck(struct thread *td, struct vnode *vp, acl_type_t type,
struct acl *aclp)
{
struct acl *inkernelacl;
int error;
inkernelacl = acl_alloc(M_WAITOK);
error = copyin(aclp, inkernelacl, sizeof(struct acl));
if (error)
goto out;
error = VOP_ACLCHECK(vp, type, inkernelacl, td->td_ucred, td);
out:
acl_free(inkernelacl);
return (error);
}
/*
* syscalls -- convert the path/fd to a vnode, and call vacl_whatever. Don't
* need to lock, as the vacl_ code will get/release any locks required.
*/
/*
* Given a file path, get an ACL for it
*/
int
__acl_get_file(struct thread *td, struct __acl_get_file_args *uap)
{
struct nameidata nd;
int vfslocked, error;
NDINIT(&nd, LOOKUP, MPSAFE|FOLLOW, UIO_USERSPACE, uap->path, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vacl_get_acl(td, nd.ni_vp, uap->type, uap->aclp);
NDFREE(&nd, 0);
}
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
/*
* Given a file path, get an ACL for it; don't follow links.
*/
int
__acl_get_link(struct thread *td, struct __acl_get_link_args *uap)
{
struct nameidata nd;
int vfslocked, error;
NDINIT(&nd, LOOKUP, MPSAFE|NOFOLLOW, UIO_USERSPACE, uap->path, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vacl_get_acl(td, nd.ni_vp, uap->type, uap->aclp);
NDFREE(&nd, 0);
}
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
/*
* Given a file path, set an ACL for it.
*/
int
__acl_set_file(struct thread *td, struct __acl_set_file_args *uap)
{
struct nameidata nd;
int vfslocked, error;
NDINIT(&nd, LOOKUP, MPSAFE|FOLLOW, UIO_USERSPACE, uap->path, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vacl_set_acl(td, nd.ni_vp, uap->type, uap->aclp);
NDFREE(&nd, 0);
}
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
/*
* Given a file path, set an ACL for it; don't follow links.
*/
int
__acl_set_link(struct thread *td, struct __acl_set_link_args *uap)
{
struct nameidata nd;
int vfslocked, error;
NDINIT(&nd, LOOKUP, MPSAFE|NOFOLLOW, UIO_USERSPACE, uap->path, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vacl_set_acl(td, nd.ni_vp, uap->type, uap->aclp);
NDFREE(&nd, 0);
}
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
/*
* Given a file descriptor, get an ACL for it.
*/
int
__acl_get_fd(struct thread *td, struct __acl_get_fd_args *uap)
{
struct file *fp;
int vfslocked, error;
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error = getvnode(td->td_proc->p_fd, uap->filedes, &fp);
if (error == 0) {
vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
error = vacl_get_acl(td, fp->f_vnode, uap->type, uap->aclp);
fdrop(fp, td);
VFS_UNLOCK_GIANT(vfslocked);
}
return (error);
}
/*
* Given a file descriptor, set an ACL for it.
*/
int
__acl_set_fd(struct thread *td, struct __acl_set_fd_args *uap)
{
struct file *fp;
int vfslocked, error;
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error = getvnode(td->td_proc->p_fd, uap->filedes, &fp);
if (error == 0) {
vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
error = vacl_set_acl(td, fp->f_vnode, uap->type, uap->aclp);
fdrop(fp, td);
VFS_UNLOCK_GIANT(vfslocked);
}
return (error);
}
/*
* Given a file path, delete an ACL from it.
*/
int
__acl_delete_file(struct thread *td, struct __acl_delete_file_args *uap)
{
struct nameidata nd;
int vfslocked, error;
NDINIT(&nd, LOOKUP, MPSAFE|FOLLOW, UIO_USERSPACE, uap->path, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
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error = vacl_delete(td, nd.ni_vp, uap->type);
NDFREE(&nd, 0);
}
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
/*
* Given a file path, delete an ACL from it; don't follow links.
*/
int
__acl_delete_link(struct thread *td, struct __acl_delete_link_args *uap)
{
struct nameidata nd;
int vfslocked, error;
NDINIT(&nd, LOOKUP, MPSAFE|NOFOLLOW, UIO_USERSPACE, uap->path, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vacl_delete(td, nd.ni_vp, uap->type);
NDFREE(&nd, 0);
}
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
/*
* Given a file path, delete an ACL from it.
*/
int
__acl_delete_fd(struct thread *td, struct __acl_delete_fd_args *uap)
{
struct file *fp;
int vfslocked, error;
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error = getvnode(td->td_proc->p_fd, uap->filedes, &fp);
if (error == 0) {
vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
error = vacl_delete(td, fp->f_vnode, uap->type);
fdrop(fp, td);
VFS_UNLOCK_GIANT(vfslocked);
}
return (error);
}
/*
* Given a file path, check an ACL for it.
*/
int
__acl_aclcheck_file(struct thread *td, struct __acl_aclcheck_file_args *uap)
{
struct nameidata nd;
int vfslocked, error;
NDINIT(&nd, LOOKUP, MPSAFE|FOLLOW, UIO_USERSPACE, uap->path, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vacl_aclcheck(td, nd.ni_vp, uap->type, uap->aclp);
NDFREE(&nd, 0);
}
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
/*
* Given a file path, check an ACL for it; don't follow links.
*/
int
__acl_aclcheck_link(struct thread *td, struct __acl_aclcheck_link_args *uap)
{
struct nameidata nd;
int vfslocked, error;
NDINIT(&nd, LOOKUP, MPSAFE|NOFOLLOW, UIO_USERSPACE, uap->path, td);
error = namei(&nd);
vfslocked = NDHASGIANT(&nd);
if (error == 0) {
error = vacl_aclcheck(td, nd.ni_vp, uap->type, uap->aclp);
NDFREE(&nd, 0);
}
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
/*
* Given a file descriptor, check an ACL for it.
*/
int
__acl_aclcheck_fd(struct thread *td, struct __acl_aclcheck_fd_args *uap)
{
struct file *fp;
int vfslocked, error;
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error = getvnode(td->td_proc->p_fd, uap->filedes, &fp);
if (error == 0) {
vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
error = vacl_aclcheck(td, fp->f_vnode, uap->type, uap->aclp);
fdrop(fp, td);
VFS_UNLOCK_GIANT(vfslocked);
}
return (error);
}
struct acl *
acl_alloc(int flags)
{
struct acl *aclp;
aclp = malloc(sizeof(*aclp), M_ACL, flags);
return (aclp);
}
void
acl_free(struct acl *aclp)
{
free(aclp, M_ACL);
}