freebsd-dev/sys/kern/vfs_acl.c
Edward Tomasz Napierala e0ee758989 When allocating 'struct acl' instances, use malloc(9) instead of uma(9).
This struct will get much bigger soon, and we don't want to waste too much
memory on UMA caches.

Reviewed by:	rwatson
2009-04-19 09:56:30 +00:00

443 lines
10 KiB
C

/*-
* 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.
*/
#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");
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,
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;
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;
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) {
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;
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;
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);
}