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");
71 static int kern___acl_aclcheck_path(struct thread *td, const char *path,
72 acl_type_t type, struct acl *aclp, int follow);
73 static int kern___acl_delete_path(struct thread *td, const char *path,
74 acl_type_t type, int follow);
75 static int kern___acl_get_path(struct thread *td, const char *path,
76 acl_type_t type, struct acl *aclp, int follow);
77 static int kern___acl_set_path(struct thread *td, const char *path,
78 acl_type_t type, const struct acl *aclp, int follow);
79 static int vacl_set_acl(struct thread *td, struct vnode *vp,
80 acl_type_t type, const struct acl *aclp);
81 static int vacl_get_acl(struct thread *td, struct vnode *vp,
82 acl_type_t type, struct acl *aclp);
83 static int vacl_aclcheck(struct thread *td, struct vnode *vp,
84 acl_type_t type, const struct acl *aclp);
87 acl_copy_oldacl_into_acl(const struct oldacl *source, struct acl *dest)
91 if (source->acl_cnt < 0 || source->acl_cnt > OLDACL_MAX_ENTRIES)
94 bzero(dest, sizeof(*dest));
96 dest->acl_cnt = source->acl_cnt;
97 dest->acl_maxcnt = ACL_MAX_ENTRIES;
99 for (i = 0; i < dest->acl_cnt; i++) {
100 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
101 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
102 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
109 acl_copy_acl_into_oldacl(const struct acl *source, struct oldacl *dest)
113 if (source->acl_cnt > OLDACL_MAX_ENTRIES)
116 bzero(dest, sizeof(*dest));
118 dest->acl_cnt = source->acl_cnt;
120 for (i = 0; i < dest->acl_cnt; i++) {
121 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
122 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
123 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
130 * At one time, "struct ACL" was extended in order to add support for NFSv4
131 * ACLs. Instead of creating compatibility versions of all the ACL-related
132 * syscalls, they were left intact. It's possible to find out what the code
133 * calling these syscalls (libc) expects basing on "type" argument - if it's
134 * either ACL_TYPE_ACCESS_OLD or ACL_TYPE_DEFAULT_OLD (which previously were
135 * known as ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT), then it's the "struct
136 * oldacl". If it's something else, then it's the new "struct acl". In the
137 * latter case, the routines below just copyin/copyout the contents. In the
138 * former case, they copyin the "struct oldacl" and convert it to the new
142 acl_copyin(const void *user_acl, struct acl *kernel_acl, acl_type_t type)
148 case ACL_TYPE_ACCESS_OLD:
149 case ACL_TYPE_DEFAULT_OLD:
150 error = copyin(user_acl, &old, sizeof(old));
153 acl_copy_oldacl_into_acl(&old, kernel_acl);
157 error = copyin(user_acl, kernel_acl, sizeof(*kernel_acl));
158 if (kernel_acl->acl_maxcnt != ACL_MAX_ENTRIES)
166 acl_copyout(const struct acl *kernel_acl, void *user_acl, acl_type_t type)
173 case ACL_TYPE_ACCESS_OLD:
174 case ACL_TYPE_DEFAULT_OLD:
175 error = acl_copy_acl_into_oldacl(kernel_acl, &old);
179 error = copyout(&old, user_acl, sizeof(old));
183 error = fueword32((char *)user_acl +
184 offsetof(struct acl, acl_maxcnt), &am);
187 if (am != ACL_MAX_ENTRIES)
190 error = copyout(kernel_acl, user_acl, sizeof(*kernel_acl));
197 * Convert "old" type - ACL_TYPE_{ACCESS,DEFAULT}_OLD - into its "new"
198 * counterpart. It's required for old (pre-NFSv4 ACLs) libc to work
199 * with new kernel. Fixing 'type' for old binaries with new libc
200 * is being done in lib/libc/posix1e/acl_support.c:_acl_type_unold().
203 acl_type_unold(int type)
206 case ACL_TYPE_ACCESS_OLD:
207 return (ACL_TYPE_ACCESS);
209 case ACL_TYPE_DEFAULT_OLD:
210 return (ACL_TYPE_DEFAULT);
218 * These calls wrap the real vnode operations, and are called by the syscall
219 * code once the syscall has converted the path or file descriptor to a vnode
220 * (unlocked). The aclp pointer is assumed still to point to userland, so
221 * this should not be consumed within the kernel except by syscall code.
222 * Other code should directly invoke VOP_{SET,GET}ACL.
226 * Given a vnode, set its ACL.
229 vacl_set_acl(struct thread *td, struct vnode *vp, acl_type_t type,
230 const struct acl *aclp)
232 struct acl *inkernelacl;
236 AUDIT_ARG_VALUE(type);
237 inkernelacl = acl_alloc(M_WAITOK);
238 error = acl_copyin(aclp, inkernelacl, type);
241 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
244 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
245 AUDIT_ARG_VNODE1(vp);
247 error = mac_vnode_check_setacl(td->td_ucred, vp, type, inkernelacl);
251 error = VOP_SETACL(vp, acl_type_unold(type), inkernelacl,
257 vn_finished_write(mp);
259 acl_free(inkernelacl);
264 * Given a vnode, get its ACL.
267 vacl_get_acl(struct thread *td, struct vnode *vp, acl_type_t type,
270 struct acl *inkernelacl;
273 AUDIT_ARG_VALUE(type);
274 inkernelacl = acl_alloc(M_WAITOK | M_ZERO);
275 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
276 AUDIT_ARG_VNODE1(vp);
278 error = mac_vnode_check_getacl(td->td_ucred, vp, type);
282 error = VOP_GETACL(vp, acl_type_unold(type), inkernelacl,
290 error = acl_copyout(inkernelacl, aclp, type);
291 acl_free(inkernelacl);
296 * Given a vnode, delete its ACL.
299 vacl_delete(struct thread *td, struct vnode *vp, acl_type_t type)
304 AUDIT_ARG_VALUE(type);
305 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
308 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
309 AUDIT_ARG_VNODE1(vp);
311 error = mac_vnode_check_deleteacl(td->td_ucred, vp, type);
315 error = VOP_SETACL(vp, acl_type_unold(type), 0, td->td_ucred, td);
320 vn_finished_write(mp);
325 * Given a vnode, check whether an ACL is appropriate for it
327 * XXXRW: No vnode lock held so can't audit vnode state...?
330 vacl_aclcheck(struct thread *td, struct vnode *vp, acl_type_t type,
331 const struct acl *aclp)
333 struct acl *inkernelacl;
336 inkernelacl = acl_alloc(M_WAITOK);
337 error = acl_copyin(aclp, inkernelacl, type);
340 error = VOP_ACLCHECK(vp, acl_type_unold(type), inkernelacl,
343 acl_free(inkernelacl);
348 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. Don't
349 * need to lock, as the vacl_ code will get/release any locks required.
353 * Given a file path, get an ACL for it
356 sys___acl_get_file(struct thread *td, struct __acl_get_file_args *uap)
359 return (kern___acl_get_path(td, uap->path, uap->type, uap->aclp,
364 * Given a file path, get an ACL for it; don't follow links.
367 sys___acl_get_link(struct thread *td, struct __acl_get_link_args *uap)
370 return(kern___acl_get_path(td, uap->path, uap->type, uap->aclp,
375 kern___acl_get_path(struct thread *td, const char *path, acl_type_t type,
376 struct acl *aclp, int follow)
381 NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, UIO_USERSPACE, path, td);
384 error = vacl_get_acl(td, nd.ni_vp, type, aclp);
391 * Given a file path, set an ACL for it.
394 sys___acl_set_file(struct thread *td, struct __acl_set_file_args *uap)
397 return(kern___acl_set_path(td, uap->path, uap->type, uap->aclp,
402 * Given a file path, set an ACL for it; don't follow links.
405 sys___acl_set_link(struct thread *td, struct __acl_set_link_args *uap)
408 return(kern___acl_set_path(td, uap->path, uap->type, uap->aclp,
413 kern___acl_set_path(struct thread *td, const char *path,
414 acl_type_t type, const struct acl *aclp, int follow)
419 NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, UIO_USERSPACE, path, td);
422 error = vacl_set_acl(td, nd.ni_vp, type, aclp);
429 * Given a file descriptor, get an ACL for it.
432 sys___acl_get_fd(struct thread *td, struct __acl_get_fd_args *uap)
438 AUDIT_ARG_FD(uap->filedes);
439 error = getvnode(td, uap->filedes,
440 cap_rights_init(&rights, CAP_ACL_GET), &fp);
442 error = vacl_get_acl(td, fp->f_vnode, uap->type, uap->aclp);
449 * Given a file descriptor, set an ACL for it.
452 sys___acl_set_fd(struct thread *td, struct __acl_set_fd_args *uap)
458 AUDIT_ARG_FD(uap->filedes);
459 error = getvnode(td, uap->filedes,
460 cap_rights_init(&rights, CAP_ACL_SET), &fp);
462 error = vacl_set_acl(td, fp->f_vnode, uap->type, uap->aclp);
469 * Given a file path, delete an ACL from it.
472 sys___acl_delete_file(struct thread *td, struct __acl_delete_file_args *uap)
475 return (kern___acl_delete_path(td, uap->path, uap->type, FOLLOW));
479 * Given a file path, delete an ACL from it; don't follow links.
482 sys___acl_delete_link(struct thread *td, struct __acl_delete_link_args *uap)
485 return (kern___acl_delete_path(td, uap->path, uap->type, NOFOLLOW));
489 kern___acl_delete_path(struct thread *td, const char *path,
490 acl_type_t type, int follow)
495 NDINIT(&nd, LOOKUP, follow, UIO_USERSPACE, path, td);
498 error = vacl_delete(td, nd.ni_vp, type);
505 * Given a file path, delete an ACL from it.
508 sys___acl_delete_fd(struct thread *td, struct __acl_delete_fd_args *uap)
514 AUDIT_ARG_FD(uap->filedes);
515 error = getvnode(td, uap->filedes,
516 cap_rights_init(&rights, CAP_ACL_DELETE), &fp);
518 error = vacl_delete(td, fp->f_vnode, uap->type);
525 * Given a file path, check an ACL for it.
528 sys___acl_aclcheck_file(struct thread *td, struct __acl_aclcheck_file_args *uap)
531 return (kern___acl_aclcheck_path(td, uap->path, uap->type, uap->aclp,
536 * Given a file path, check an ACL for it; don't follow links.
539 sys___acl_aclcheck_link(struct thread *td, struct __acl_aclcheck_link_args *uap)
541 return (kern___acl_aclcheck_path(td, uap->path, uap->type, uap->aclp,
546 kern___acl_aclcheck_path(struct thread *td, const char *path, acl_type_t type,
547 struct acl *aclp, int follow)
552 NDINIT(&nd, LOOKUP, follow, UIO_USERSPACE, path, td);
555 error = vacl_aclcheck(td, nd.ni_vp, type, aclp);
562 * Given a file descriptor, check an ACL for it.
565 sys___acl_aclcheck_fd(struct thread *td, struct __acl_aclcheck_fd_args *uap)
571 AUDIT_ARG_FD(uap->filedes);
572 error = getvnode(td, uap->filedes,
573 cap_rights_init(&rights, CAP_ACL_CHECK), &fp);
575 error = vacl_aclcheck(td, fp->f_vnode, uap->type, uap->aclp);
586 aclp = malloc(sizeof(*aclp), M_ACL, flags);
590 aclp->acl_maxcnt = ACL_MAX_ENTRIES;
596 acl_free(struct acl *aclp)