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>
62 #include <security/audit/audit.h>
63 #include <security/mac/mac_framework.h>
65 CTASSERT(ACL_MAX_ENTRIES >= OLDACL_MAX_ENTRIES);
67 MALLOC_DEFINE(M_ACL, "acl", "Access Control Lists");
69 static int kern___acl_aclcheck_path(struct thread *td, const char *path,
70 acl_type_t type, struct acl *aclp, int follow);
71 static int kern___acl_delete_path(struct thread *td, const char *path,
72 acl_type_t type, int follow);
73 static int kern___acl_get_path(struct thread *td, const char *path,
74 acl_type_t type, struct acl *aclp, int follow);
75 static int kern___acl_set_path(struct thread *td, const char *path,
76 acl_type_t type, const struct acl *aclp, int follow);
77 static int vacl_set_acl(struct thread *td, struct vnode *vp,
78 acl_type_t type, const struct acl *aclp);
79 static int vacl_get_acl(struct thread *td, struct vnode *vp,
80 acl_type_t type, struct acl *aclp);
81 static int vacl_aclcheck(struct thread *td, struct vnode *vp,
82 acl_type_t type, const struct acl *aclp);
85 acl_copy_oldacl_into_acl(const struct oldacl *source, struct acl *dest)
89 if (source->acl_cnt < 0 || source->acl_cnt > OLDACL_MAX_ENTRIES)
92 bzero(dest, sizeof(*dest));
94 dest->acl_cnt = source->acl_cnt;
95 dest->acl_maxcnt = ACL_MAX_ENTRIES;
97 for (i = 0; i < dest->acl_cnt; i++) {
98 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
99 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
100 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
107 acl_copy_acl_into_oldacl(const struct acl *source, struct oldacl *dest)
111 if (source->acl_cnt > OLDACL_MAX_ENTRIES)
114 bzero(dest, sizeof(*dest));
116 dest->acl_cnt = source->acl_cnt;
118 for (i = 0; i < dest->acl_cnt; i++) {
119 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
120 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
121 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
128 * At one time, "struct ACL" was extended in order to add support for NFSv4
129 * ACLs. Instead of creating compatibility versions of all the ACL-related
130 * syscalls, they were left intact. It's possible to find out what the code
131 * calling these syscalls (libc) expects basing on "type" argument - if it's
132 * either ACL_TYPE_ACCESS_OLD or ACL_TYPE_DEFAULT_OLD (which previously were
133 * known as ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT), then it's the "struct
134 * oldacl". If it's something else, then it's the new "struct acl". In the
135 * latter case, the routines below just copyin/copyout the contents. In the
136 * former case, they copyin the "struct oldacl" and convert it to the new
140 acl_copyin(const void *user_acl, struct acl *kernel_acl, acl_type_t type)
146 case ACL_TYPE_ACCESS_OLD:
147 case ACL_TYPE_DEFAULT_OLD:
148 error = copyin(user_acl, &old, sizeof(old));
151 acl_copy_oldacl_into_acl(&old, kernel_acl);
155 error = copyin(user_acl, kernel_acl, sizeof(*kernel_acl));
156 if (kernel_acl->acl_maxcnt != ACL_MAX_ENTRIES)
164 acl_copyout(const struct acl *kernel_acl, void *user_acl, acl_type_t type)
171 case ACL_TYPE_ACCESS_OLD:
172 case ACL_TYPE_DEFAULT_OLD:
173 error = acl_copy_acl_into_oldacl(kernel_acl, &old);
177 error = copyout(&old, user_acl, sizeof(old));
181 error = fueword32((char *)user_acl +
182 offsetof(struct acl, acl_maxcnt), &am);
185 if (am != ACL_MAX_ENTRIES)
188 error = copyout(kernel_acl, user_acl, sizeof(*kernel_acl));
195 * Convert "old" type - ACL_TYPE_{ACCESS,DEFAULT}_OLD - into its "new"
196 * counterpart. It's required for old (pre-NFSv4 ACLs) libc to work
197 * with new kernel. Fixing 'type' for old binaries with new libc
198 * is being done in lib/libc/posix1e/acl_support.c:_acl_type_unold().
201 acl_type_unold(int type)
204 case ACL_TYPE_ACCESS_OLD:
205 return (ACL_TYPE_ACCESS);
207 case ACL_TYPE_DEFAULT_OLD:
208 return (ACL_TYPE_DEFAULT);
216 * These calls wrap the real vnode operations, and are called by the syscall
217 * code once the syscall has converted the path or file descriptor to a vnode
218 * (unlocked). The aclp pointer is assumed still to point to userland, so
219 * this should not be consumed within the kernel except by syscall code.
220 * Other code should directly invoke VOP_{SET,GET}ACL.
224 * Given a vnode, set its ACL.
227 vacl_set_acl(struct thread *td, struct vnode *vp, acl_type_t type,
228 const struct acl *aclp)
230 struct acl *inkernelacl;
234 AUDIT_ARG_VALUE(type);
235 inkernelacl = acl_alloc(M_WAITOK);
236 error = acl_copyin(aclp, inkernelacl, type);
239 error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH);
242 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
243 AUDIT_ARG_VNODE1(vp);
245 error = mac_vnode_check_setacl(td->td_ucred, vp, type, inkernelacl);
249 error = VOP_SETACL(vp, acl_type_unold(type), inkernelacl,
255 vn_finished_write(mp);
257 acl_free(inkernelacl);
262 * Given a vnode, get its ACL.
265 vacl_get_acl(struct thread *td, struct vnode *vp, acl_type_t type,
268 struct acl *inkernelacl;
271 AUDIT_ARG_VALUE(type);
272 inkernelacl = acl_alloc(M_WAITOK | M_ZERO);
273 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
274 AUDIT_ARG_VNODE1(vp);
276 error = mac_vnode_check_getacl(td->td_ucred, vp, type);
280 error = VOP_GETACL(vp, acl_type_unold(type), inkernelacl,
288 error = acl_copyout(inkernelacl, aclp, type);
289 acl_free(inkernelacl);
294 * Given a vnode, delete its ACL.
297 vacl_delete(struct thread *td, struct vnode *vp, acl_type_t type)
302 AUDIT_ARG_VALUE(type);
303 error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH);
306 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
307 AUDIT_ARG_VNODE1(vp);
309 error = mac_vnode_check_deleteacl(td->td_ucred, vp, type);
313 error = VOP_SETACL(vp, acl_type_unold(type), 0, td->td_ucred, td);
318 vn_finished_write(mp);
323 * Given a vnode, check whether an ACL is appropriate for it
325 * XXXRW: No vnode lock held so can't audit vnode state...?
328 vacl_aclcheck(struct thread *td, struct vnode *vp, acl_type_t type,
329 const struct acl *aclp)
331 struct acl *inkernelacl;
334 inkernelacl = acl_alloc(M_WAITOK);
335 error = acl_copyin(aclp, inkernelacl, type);
338 error = VOP_ACLCHECK(vp, acl_type_unold(type), inkernelacl,
341 acl_free(inkernelacl);
346 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. Don't
347 * need to lock, as the vacl_ code will get/release any locks required.
351 * Given a file path, get an ACL for it
354 sys___acl_get_file(struct thread *td, struct __acl_get_file_args *uap)
357 return (kern___acl_get_path(td, uap->path, uap->type, uap->aclp,
362 * Given a file path, get an ACL for it; don't follow links.
365 sys___acl_get_link(struct thread *td, struct __acl_get_link_args *uap)
368 return(kern___acl_get_path(td, uap->path, uap->type, uap->aclp,
373 kern___acl_get_path(struct thread *td, const char *path, acl_type_t type,
374 struct acl *aclp, int follow)
379 NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, UIO_USERSPACE, path);
382 error = vacl_get_acl(td, nd.ni_vp, type, aclp);
390 * Given a file path, set an ACL for it.
393 sys___acl_set_file(struct thread *td, struct __acl_set_file_args *uap)
396 return(kern___acl_set_path(td, uap->path, 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)
407 return(kern___acl_set_path(td, uap->path, uap->type, uap->aclp,
412 kern___acl_set_path(struct thread *td, const char *path,
413 acl_type_t type, const struct acl *aclp, int follow)
418 NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, UIO_USERSPACE, path);
421 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_one(&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_one(&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);
498 error = vacl_delete(td, nd.ni_vp, type);
506 * Given a file path, delete an ACL from it.
509 sys___acl_delete_fd(struct thread *td, struct __acl_delete_fd_args *uap)
515 AUDIT_ARG_FD(uap->filedes);
516 error = getvnode(td, uap->filedes,
517 cap_rights_init_one(&rights, CAP_ACL_DELETE), &fp);
519 error = vacl_delete(td, fp->f_vnode, uap->type);
526 * Given a file path, check an ACL for it.
529 sys___acl_aclcheck_file(struct thread *td, struct __acl_aclcheck_file_args *uap)
532 return (kern___acl_aclcheck_path(td, uap->path, uap->type, uap->aclp,
537 * Given a file path, check an ACL for it; don't follow links.
540 sys___acl_aclcheck_link(struct thread *td, struct __acl_aclcheck_link_args *uap)
542 return (kern___acl_aclcheck_path(td, uap->path, uap->type, uap->aclp,
547 kern___acl_aclcheck_path(struct thread *td, const char *path, acl_type_t type,
548 struct acl *aclp, int follow)
553 NDINIT(&nd, LOOKUP, follow, UIO_USERSPACE, path);
556 error = vacl_aclcheck(td, nd.ni_vp, type, aclp);
563 * Given a file descriptor, check an ACL for it.
566 sys___acl_aclcheck_fd(struct thread *td, struct __acl_aclcheck_fd_args *uap)
572 AUDIT_ARG_FD(uap->filedes);
573 error = getvnode(td, uap->filedes,
574 cap_rights_init_one(&rights, CAP_ACL_CHECK), &fp);
576 error = vacl_aclcheck(td, fp->f_vnode, uap->type, uap->aclp);
587 aclp = malloc(sizeof(*aclp), M_ACL, flags);
591 aclp->acl_maxcnt = ACL_MAX_ENTRIES;
597 acl_free(struct acl *aclp)