2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1999-2006, 2016-2017 Robert N. M. Watson
7 * This software was developed by Robert Watson for the TrustedBSD Project.
9 * Portions of this software were developed by BAE Systems, the University of
10 * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
11 * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
12 * Computing (TC) research program.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * Developed by the TrustedBSD Project.
38 * ACL system calls and other functions common across different ACL types.
39 * Type-specific routines go into subr_acl_<type>.c.
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/sysproto.h>
48 #include <sys/capsicum.h>
49 #include <sys/fcntl.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.h>
52 #include <sys/mount.h>
53 #include <sys/vnode.h>
55 #include <sys/mutex.h>
56 #include <sys/namei.h>
58 #include <sys/filedesc.h>
60 #include <sys/sysent.h>
63 #include <security/audit/audit.h>
64 #include <security/mac/mac_framework.h>
66 CTASSERT(ACL_MAX_ENTRIES >= OLDACL_MAX_ENTRIES);
68 MALLOC_DEFINE(M_ACL, "acl", "Access Control Lists");
70 static int vacl_set_acl(struct thread *td, struct vnode *vp,
71 acl_type_t type, struct acl *aclp);
72 static int vacl_get_acl(struct thread *td, struct vnode *vp,
73 acl_type_t type, struct acl *aclp);
74 static int vacl_aclcheck(struct thread *td, struct vnode *vp,
75 acl_type_t type, struct acl *aclp);
78 acl_copy_oldacl_into_acl(const struct oldacl *source, struct acl *dest)
82 if (source->acl_cnt < 0 || source->acl_cnt > OLDACL_MAX_ENTRIES)
85 bzero(dest, sizeof(*dest));
87 dest->acl_cnt = source->acl_cnt;
88 dest->acl_maxcnt = ACL_MAX_ENTRIES;
90 for (i = 0; i < dest->acl_cnt; i++) {
91 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
92 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
93 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
100 acl_copy_acl_into_oldacl(const struct acl *source, struct oldacl *dest)
104 if (source->acl_cnt > OLDACL_MAX_ENTRIES)
107 bzero(dest, sizeof(*dest));
109 dest->acl_cnt = source->acl_cnt;
111 for (i = 0; i < dest->acl_cnt; i++) {
112 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
113 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
114 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
121 * At one time, "struct ACL" was extended in order to add support for NFSv4
122 * ACLs. Instead of creating compatibility versions of all the ACL-related
123 * syscalls, they were left intact. It's possible to find out what the code
124 * calling these syscalls (libc) expects basing on "type" argument - if it's
125 * either ACL_TYPE_ACCESS_OLD or ACL_TYPE_DEFAULT_OLD (which previously were
126 * known as ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT), then it's the "struct
127 * oldacl". If it's something else, then it's the new "struct acl". In the
128 * latter case, the routines below just copyin/copyout the contents. In the
129 * former case, they copyin the "struct oldacl" and convert it to the new
133 acl_copyin(void *user_acl, struct acl *kernel_acl, acl_type_t type)
139 case ACL_TYPE_ACCESS_OLD:
140 case ACL_TYPE_DEFAULT_OLD:
141 error = copyin(user_acl, &old, sizeof(old));
144 acl_copy_oldacl_into_acl(&old, kernel_acl);
148 error = copyin(user_acl, kernel_acl, sizeof(*kernel_acl));
149 if (kernel_acl->acl_maxcnt != ACL_MAX_ENTRIES)
157 acl_copyout(struct acl *kernel_acl, void *user_acl, acl_type_t type)
164 case ACL_TYPE_ACCESS_OLD:
165 case ACL_TYPE_DEFAULT_OLD:
166 error = acl_copy_acl_into_oldacl(kernel_acl, &old);
170 error = copyout(&old, user_acl, sizeof(old));
174 error = fueword32((char *)user_acl +
175 offsetof(struct acl, acl_maxcnt), &am);
178 if (am != ACL_MAX_ENTRIES)
181 error = copyout(kernel_acl, user_acl, sizeof(*kernel_acl));
188 * Convert "old" type - ACL_TYPE_{ACCESS,DEFAULT}_OLD - into its "new"
189 * counterpart. It's required for old (pre-NFSv4 ACLs) libc to work
190 * with new kernel. Fixing 'type' for old binaries with new libc
191 * is being done in lib/libc/posix1e/acl_support.c:_acl_type_unold().
194 acl_type_unold(int type)
197 case ACL_TYPE_ACCESS_OLD:
198 return (ACL_TYPE_ACCESS);
200 case ACL_TYPE_DEFAULT_OLD:
201 return (ACL_TYPE_DEFAULT);
209 * These calls wrap the real vnode operations, and are called by the syscall
210 * code once the syscall has converted the path or file descriptor to a vnode
211 * (unlocked). The aclp pointer is assumed still to point to userland, so
212 * this should not be consumed within the kernel except by syscall code.
213 * Other code should directly invoke VOP_{SET,GET}ACL.
217 * Given a vnode, set its ACL.
220 vacl_set_acl(struct thread *td, struct vnode *vp, acl_type_t type,
223 struct acl *inkernelacl;
227 AUDIT_ARG_VALUE(type);
228 inkernelacl = acl_alloc(M_WAITOK);
229 error = acl_copyin(aclp, inkernelacl, type);
232 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
235 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
236 AUDIT_ARG_VNODE1(vp);
238 error = mac_vnode_check_setacl(td->td_ucred, vp, type, inkernelacl);
242 error = VOP_SETACL(vp, acl_type_unold(type), inkernelacl,
248 vn_finished_write(mp);
250 acl_free(inkernelacl);
255 * Given a vnode, get its ACL.
258 vacl_get_acl(struct thread *td, struct vnode *vp, acl_type_t type,
261 struct acl *inkernelacl;
264 AUDIT_ARG_VALUE(type);
265 inkernelacl = acl_alloc(M_WAITOK | M_ZERO);
266 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
267 AUDIT_ARG_VNODE1(vp);
269 error = mac_vnode_check_getacl(td->td_ucred, vp, type);
273 error = VOP_GETACL(vp, acl_type_unold(type), inkernelacl,
281 error = acl_copyout(inkernelacl, aclp, type);
282 acl_free(inkernelacl);
287 * Given a vnode, delete its ACL.
290 vacl_delete(struct thread *td, struct vnode *vp, acl_type_t type)
295 AUDIT_ARG_VALUE(type);
296 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
299 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
300 AUDIT_ARG_VNODE1(vp);
302 error = mac_vnode_check_deleteacl(td->td_ucred, vp, type);
306 error = VOP_SETACL(vp, acl_type_unold(type), 0, td->td_ucred, td);
311 vn_finished_write(mp);
316 * Given a vnode, check whether an ACL is appropriate for it
318 * XXXRW: No vnode lock held so can't audit vnode state...?
321 vacl_aclcheck(struct thread *td, struct vnode *vp, acl_type_t type,
324 struct acl *inkernelacl;
327 inkernelacl = acl_alloc(M_WAITOK);
328 error = acl_copyin(aclp, inkernelacl, type);
331 error = VOP_ACLCHECK(vp, acl_type_unold(type), inkernelacl,
334 acl_free(inkernelacl);
339 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. Don't
340 * need to lock, as the vacl_ code will get/release any locks required.
344 * Given a file path, get an ACL for it
347 sys___acl_get_file(struct thread *td, struct __acl_get_file_args *uap)
352 NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, UIO_USERSPACE, uap->path,
356 error = vacl_get_acl(td, nd.ni_vp, uap->type, uap->aclp);
363 * Given a file path, get an ACL for it; don't follow links.
366 sys___acl_get_link(struct thread *td, struct __acl_get_link_args *uap)
371 NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, UIO_USERSPACE, uap->path,
375 error = vacl_get_acl(td, nd.ni_vp, uap->type, uap->aclp);
382 * Given a file path, set an ACL for it.
385 sys___acl_set_file(struct thread *td, struct __acl_set_file_args *uap)
390 NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, UIO_USERSPACE, uap->path,
394 error = vacl_set_acl(td, nd.ni_vp, uap->type, uap->aclp);
401 * Given a file path, set an ACL for it; don't follow links.
404 sys___acl_set_link(struct thread *td, struct __acl_set_link_args *uap)
409 NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, UIO_USERSPACE, uap->path,
413 error = vacl_set_acl(td, nd.ni_vp, uap->type, uap->aclp);
420 * Given a file descriptor, get an ACL for it.
423 sys___acl_get_fd(struct thread *td, struct __acl_get_fd_args *uap)
429 AUDIT_ARG_FD(uap->filedes);
430 error = getvnode(td, uap->filedes,
431 cap_rights_init(&rights, CAP_ACL_GET), &fp);
433 error = vacl_get_acl(td, fp->f_vnode, uap->type, uap->aclp);
440 * Given a file descriptor, set an ACL for it.
443 sys___acl_set_fd(struct thread *td, struct __acl_set_fd_args *uap)
449 AUDIT_ARG_FD(uap->filedes);
450 error = getvnode(td, uap->filedes,
451 cap_rights_init(&rights, CAP_ACL_SET), &fp);
453 error = vacl_set_acl(td, fp->f_vnode, uap->type, uap->aclp);
460 * Given a file path, delete an ACL from it.
463 sys___acl_delete_file(struct thread *td, struct __acl_delete_file_args *uap)
468 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->path, td);
471 error = vacl_delete(td, nd.ni_vp, uap->type);
478 * Given a file path, delete an ACL from it; don't follow links.
481 sys___acl_delete_link(struct thread *td, struct __acl_delete_link_args *uap)
486 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->path, td);
489 error = vacl_delete(td, nd.ni_vp, uap->type);
496 * Given a file path, delete an ACL from it.
499 sys___acl_delete_fd(struct thread *td, struct __acl_delete_fd_args *uap)
505 AUDIT_ARG_FD(uap->filedes);
506 error = getvnode(td, uap->filedes,
507 cap_rights_init(&rights, CAP_ACL_DELETE), &fp);
509 error = vacl_delete(td, fp->f_vnode, uap->type);
516 * Given a file path, check an ACL for it.
519 sys___acl_aclcheck_file(struct thread *td, struct __acl_aclcheck_file_args *uap)
524 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->path, td);
527 error = vacl_aclcheck(td, nd.ni_vp, uap->type, uap->aclp);
534 * Given a file path, check an ACL for it; don't follow links.
537 sys___acl_aclcheck_link(struct thread *td, struct __acl_aclcheck_link_args *uap)
542 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->path, td);
545 error = vacl_aclcheck(td, nd.ni_vp, uap->type, uap->aclp);
552 * Given a file descriptor, check an ACL for it.
555 sys___acl_aclcheck_fd(struct thread *td, struct __acl_aclcheck_fd_args *uap)
561 AUDIT_ARG_FD(uap->filedes);
562 error = getvnode(td, uap->filedes,
563 cap_rights_init(&rights, CAP_ACL_CHECK), &fp);
565 error = vacl_aclcheck(td, fp->f_vnode, uap->type, uap->aclp);
576 aclp = malloc(sizeof(*aclp), M_ACL, flags);
580 aclp->acl_maxcnt = ACL_MAX_ENTRIES;
586 acl_free(struct acl *aclp)