2 * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/sysproto.h>
46 #include <sys/capsicum.h>
47 #include <sys/fcntl.h>
48 #include <sys/kernel.h>
49 #include <sys/malloc.h>
50 #include <sys/mount.h>
51 #include <sys/vnode.h>
53 #include <sys/mutex.h>
54 #include <sys/namei.h>
56 #include <sys/filedesc.h>
60 #include <security/audit/audit.h>
61 #include <security/mac/mac_framework.h>
63 CTASSERT(ACL_MAX_ENTRIES >= OLDACL_MAX_ENTRIES);
65 MALLOC_DEFINE(M_ACL, "acl", "Access Control Lists");
67 static int kern___acl_aclcheck_path(struct thread *td, const char *path,
68 acl_type_t type, struct acl *aclp, int follow);
69 static int kern___acl_delete_path(struct thread *td, const char *path,
70 acl_type_t type, int follow);
71 static int kern___acl_get_path(struct thread *td, const char *path,
72 acl_type_t type, struct acl *aclp, int follow);
73 static int kern___acl_set_path(struct thread *td, const char *path,
74 acl_type_t type, const struct acl *aclp, int follow);
75 static int vacl_set_acl(struct thread *td, struct vnode *vp,
76 acl_type_t type, const struct acl *aclp);
77 static int vacl_get_acl(struct thread *td, struct vnode *vp,
78 acl_type_t type, struct acl *aclp);
79 static int vacl_aclcheck(struct thread *td, struct vnode *vp,
80 acl_type_t type, const struct acl *aclp);
83 acl_copy_oldacl_into_acl(const struct oldacl *source, struct acl *dest)
87 if (source->acl_cnt < 0 || source->acl_cnt > OLDACL_MAX_ENTRIES)
90 bzero(dest, sizeof(*dest));
92 dest->acl_cnt = source->acl_cnt;
93 dest->acl_maxcnt = ACL_MAX_ENTRIES;
95 for (i = 0; i < dest->acl_cnt; i++) {
96 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
97 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
98 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
105 acl_copy_acl_into_oldacl(const struct acl *source, struct oldacl *dest)
109 if (source->acl_cnt > OLDACL_MAX_ENTRIES)
112 bzero(dest, sizeof(*dest));
114 dest->acl_cnt = source->acl_cnt;
116 for (i = 0; i < dest->acl_cnt; i++) {
117 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
118 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
119 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
126 * At one time, "struct ACL" was extended in order to add support for NFSv4
127 * ACLs. Instead of creating compatibility versions of all the ACL-related
128 * syscalls, they were left intact. It's possible to find out what the code
129 * calling these syscalls (libc) expects basing on "type" argument - if it's
130 * either ACL_TYPE_ACCESS_OLD or ACL_TYPE_DEFAULT_OLD (which previously were
131 * known as ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT), then it's the "struct
132 * oldacl". If it's something else, then it's the new "struct acl". In the
133 * latter case, the routines below just copyin/copyout the contents. In the
134 * former case, they copyin the "struct oldacl" and convert it to the new
138 acl_copyin(const void *user_acl, struct acl *kernel_acl, acl_type_t type)
144 case ACL_TYPE_ACCESS_OLD:
145 case ACL_TYPE_DEFAULT_OLD:
146 error = copyin(user_acl, &old, sizeof(old));
149 acl_copy_oldacl_into_acl(&old, kernel_acl);
153 error = copyin(user_acl, kernel_acl, sizeof(*kernel_acl));
154 if (kernel_acl->acl_maxcnt != ACL_MAX_ENTRIES)
162 acl_copyout(const struct acl *kernel_acl, void *user_acl, acl_type_t type)
169 case ACL_TYPE_ACCESS_OLD:
170 case ACL_TYPE_DEFAULT_OLD:
171 error = acl_copy_acl_into_oldacl(kernel_acl, &old);
175 error = copyout(&old, user_acl, sizeof(old));
179 error = fueword32((char *)user_acl +
180 offsetof(struct acl, acl_maxcnt), &am);
183 if (am != ACL_MAX_ENTRIES)
186 error = copyout(kernel_acl, user_acl, sizeof(*kernel_acl));
193 * Convert "old" type - ACL_TYPE_{ACCESS,DEFAULT}_OLD - into its "new"
194 * counterpart. It's required for old (pre-NFSv4 ACLs) libc to work
195 * with new kernel. Fixing 'type' for old binaries with new libc
196 * is being done in lib/libc/posix1e/acl_support.c:_acl_type_unold().
199 acl_type_unold(int type)
202 case ACL_TYPE_ACCESS_OLD:
203 return (ACL_TYPE_ACCESS);
205 case ACL_TYPE_DEFAULT_OLD:
206 return (ACL_TYPE_DEFAULT);
214 * These calls wrap the real vnode operations, and are called by the syscall
215 * code once the syscall has converted the path or file descriptor to a vnode
216 * (unlocked). The aclp pointer is assumed still to point to userland, so
217 * this should not be consumed within the kernel except by syscall code.
218 * Other code should directly invoke VOP_{SET,GET}ACL.
222 * Given a vnode, set its ACL.
225 vacl_set_acl(struct thread *td, struct vnode *vp, acl_type_t type,
226 const struct acl *aclp)
228 struct acl *inkernelacl;
232 AUDIT_ARG_VALUE(type);
233 inkernelacl = acl_alloc(M_WAITOK);
234 error = acl_copyin(aclp, inkernelacl, type);
237 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
240 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
241 AUDIT_ARG_VNODE1(vp);
243 error = mac_vnode_check_setacl(td->td_ucred, vp, type, inkernelacl);
247 error = VOP_SETACL(vp, acl_type_unold(type), inkernelacl,
253 vn_finished_write(mp);
255 acl_free(inkernelacl);
260 * Given a vnode, get its ACL.
263 vacl_get_acl(struct thread *td, struct vnode *vp, acl_type_t type,
266 struct acl *inkernelacl;
269 AUDIT_ARG_VALUE(type);
270 inkernelacl = acl_alloc(M_WAITOK | M_ZERO);
271 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
272 AUDIT_ARG_VNODE1(vp);
274 error = mac_vnode_check_getacl(td->td_ucred, vp, type);
278 error = VOP_GETACL(vp, acl_type_unold(type), inkernelacl,
286 error = acl_copyout(inkernelacl, aclp, type);
287 acl_free(inkernelacl);
292 * Given a vnode, delete its ACL.
295 vacl_delete(struct thread *td, struct vnode *vp, acl_type_t type)
300 AUDIT_ARG_VALUE(type);
301 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
304 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
305 AUDIT_ARG_VNODE1(vp);
307 error = mac_vnode_check_deleteacl(td->td_ucred, vp, type);
311 error = VOP_SETACL(vp, acl_type_unold(type), 0, td->td_ucred, td);
316 vn_finished_write(mp);
321 * Given a vnode, check whether an ACL is appropriate for it
323 * XXXRW: No vnode lock held so can't audit vnode state...?
326 vacl_aclcheck(struct thread *td, struct vnode *vp, acl_type_t type,
327 const struct acl *aclp)
329 struct acl *inkernelacl;
332 inkernelacl = acl_alloc(M_WAITOK);
333 error = acl_copyin(aclp, inkernelacl, type);
336 error = VOP_ACLCHECK(vp, acl_type_unold(type), inkernelacl,
339 acl_free(inkernelacl);
344 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. Don't
345 * need to lock, as the vacl_ code will get/release any locks required.
349 * Given a file path, get an ACL for it
352 sys___acl_get_file(struct thread *td, struct __acl_get_file_args *uap)
355 return (kern___acl_get_path(td, uap->path, uap->type, uap->aclp,
360 * Given a file path, get an ACL for it; don't follow links.
363 sys___acl_get_link(struct thread *td, struct __acl_get_link_args *uap)
366 return(kern___acl_get_path(td, uap->path, uap->type, uap->aclp,
371 kern___acl_get_path(struct thread *td, const char *path, acl_type_t type,
372 struct acl *aclp, int follow)
377 NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, UIO_USERSPACE, path, td);
380 error = vacl_get_acl(td, nd.ni_vp, type, aclp);
387 * Given a file path, set an ACL for it.
390 sys___acl_set_file(struct thread *td, struct __acl_set_file_args *uap)
393 return(kern___acl_set_path(td, uap->path, uap->type, uap->aclp,
398 * Given a file path, set an ACL for it; don't follow links.
401 sys___acl_set_link(struct thread *td, struct __acl_set_link_args *uap)
404 return(kern___acl_set_path(td, uap->path, uap->type, uap->aclp,
409 kern___acl_set_path(struct thread *td, const char *path,
410 acl_type_t type, const struct acl *aclp, int follow)
415 NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, UIO_USERSPACE, path, td);
418 error = vacl_set_acl(td, nd.ni_vp, type, aclp);
425 * Given a file descriptor, get an ACL for it.
428 sys___acl_get_fd(struct thread *td, struct __acl_get_fd_args *uap)
434 AUDIT_ARG_FD(uap->filedes);
435 error = getvnode_path(td, uap->filedes,
436 cap_rights_init_one(&rights, CAP_ACL_GET), &fp);
438 error = vacl_get_acl(td, fp->f_vnode, uap->type, uap->aclp);
445 * Given a file descriptor, set an ACL for it.
448 sys___acl_set_fd(struct thread *td, struct __acl_set_fd_args *uap)
454 AUDIT_ARG_FD(uap->filedes);
455 error = getvnode(td, uap->filedes,
456 cap_rights_init_one(&rights, CAP_ACL_SET), &fp);
458 error = vacl_set_acl(td, fp->f_vnode, uap->type, uap->aclp);
465 * Given a file path, delete an ACL from it.
468 sys___acl_delete_file(struct thread *td, struct __acl_delete_file_args *uap)
471 return (kern___acl_delete_path(td, uap->path, uap->type, FOLLOW));
475 * Given a file path, delete an ACL from it; don't follow links.
478 sys___acl_delete_link(struct thread *td, struct __acl_delete_link_args *uap)
481 return (kern___acl_delete_path(td, uap->path, uap->type, NOFOLLOW));
485 kern___acl_delete_path(struct thread *td, const char *path,
486 acl_type_t type, int follow)
491 NDINIT(&nd, LOOKUP, follow, UIO_USERSPACE, path, td);
494 error = vacl_delete(td, nd.ni_vp, type);
501 * Given a file path, delete an ACL from it.
504 sys___acl_delete_fd(struct thread *td, struct __acl_delete_fd_args *uap)
510 AUDIT_ARG_FD(uap->filedes);
511 error = getvnode(td, uap->filedes,
512 cap_rights_init_one(&rights, CAP_ACL_DELETE), &fp);
514 error = vacl_delete(td, fp->f_vnode, uap->type);
521 * Given a file path, check an ACL for it.
524 sys___acl_aclcheck_file(struct thread *td, struct __acl_aclcheck_file_args *uap)
527 return (kern___acl_aclcheck_path(td, uap->path, uap->type, uap->aclp,
532 * Given a file path, check an ACL for it; don't follow links.
535 sys___acl_aclcheck_link(struct thread *td, struct __acl_aclcheck_link_args *uap)
537 return (kern___acl_aclcheck_path(td, uap->path, uap->type, uap->aclp,
542 kern___acl_aclcheck_path(struct thread *td, const char *path, acl_type_t type,
543 struct acl *aclp, int follow)
548 NDINIT(&nd, LOOKUP, follow, UIO_USERSPACE, path, td);
551 error = vacl_aclcheck(td, nd.ni_vp, type, aclp);
558 * Given a file descriptor, check an ACL for it.
561 sys___acl_aclcheck_fd(struct thread *td, struct __acl_aclcheck_fd_args *uap)
567 AUDIT_ARG_FD(uap->filedes);
568 error = getvnode_path(td, uap->filedes,
569 cap_rights_init_one(&rights, CAP_ACL_CHECK), &fp);
571 error = vacl_aclcheck(td, fp->f_vnode, uap->type, uap->aclp);
582 aclp = malloc(sizeof(*aclp), M_ACL, flags);
586 aclp->acl_maxcnt = ACL_MAX_ENTRIES;
592 acl_free(struct acl *aclp)