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 kern___acl_aclcheck_path(struct thread *td, const char *path,
71 acl_type_t type, struct acl *aclp, int follow);
72 static int kern___acl_delete_path(struct thread *td, const char *path,
73 acl_type_t type, int follow);
74 static int kern___acl_get_path(struct thread *td, const char *path,
75 acl_type_t type, struct acl *aclp, int follow);
76 static int kern___acl_set_path(struct thread *td, const char *path,
77 acl_type_t type, const struct acl *aclp, int follow);
78 static int vacl_set_acl(struct thread *td, struct vnode *vp,
79 acl_type_t type, const struct acl *aclp);
80 static int vacl_get_acl(struct thread *td, struct vnode *vp,
81 acl_type_t type, struct acl *aclp);
82 static int vacl_aclcheck(struct thread *td, struct vnode *vp,
83 acl_type_t type, const struct acl *aclp);
86 acl_copy_oldacl_into_acl(const struct oldacl *source, struct acl *dest)
90 if (source->acl_cnt < 0 || source->acl_cnt > OLDACL_MAX_ENTRIES)
93 bzero(dest, sizeof(*dest));
95 dest->acl_cnt = source->acl_cnt;
96 dest->acl_maxcnt = ACL_MAX_ENTRIES;
98 for (i = 0; i < dest->acl_cnt; i++) {
99 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
100 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
101 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
108 acl_copy_acl_into_oldacl(const struct acl *source, struct oldacl *dest)
112 if (source->acl_cnt > OLDACL_MAX_ENTRIES)
115 bzero(dest, sizeof(*dest));
117 dest->acl_cnt = source->acl_cnt;
119 for (i = 0; i < dest->acl_cnt; i++) {
120 dest->acl_entry[i].ae_tag = source->acl_entry[i].ae_tag;
121 dest->acl_entry[i].ae_id = source->acl_entry[i].ae_id;
122 dest->acl_entry[i].ae_perm = source->acl_entry[i].ae_perm;
129 * At one time, "struct ACL" was extended in order to add support for NFSv4
130 * ACLs. Instead of creating compatibility versions of all the ACL-related
131 * syscalls, they were left intact. It's possible to find out what the code
132 * calling these syscalls (libc) expects basing on "type" argument - if it's
133 * either ACL_TYPE_ACCESS_OLD or ACL_TYPE_DEFAULT_OLD (which previously were
134 * known as ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT), then it's the "struct
135 * oldacl". If it's something else, then it's the new "struct acl". In the
136 * latter case, the routines below just copyin/copyout the contents. In the
137 * former case, they copyin the "struct oldacl" and convert it to the new
141 acl_copyin(const void *user_acl, struct acl *kernel_acl, acl_type_t type)
147 case ACL_TYPE_ACCESS_OLD:
148 case ACL_TYPE_DEFAULT_OLD:
149 error = copyin(user_acl, &old, sizeof(old));
152 acl_copy_oldacl_into_acl(&old, kernel_acl);
156 error = copyin(user_acl, kernel_acl, sizeof(*kernel_acl));
157 if (kernel_acl->acl_maxcnt != ACL_MAX_ENTRIES)
165 acl_copyout(const struct acl *kernel_acl, void *user_acl, acl_type_t type)
172 case ACL_TYPE_ACCESS_OLD:
173 case ACL_TYPE_DEFAULT_OLD:
174 error = acl_copy_acl_into_oldacl(kernel_acl, &old);
178 error = copyout(&old, user_acl, sizeof(old));
182 error = fueword32((char *)user_acl +
183 offsetof(struct acl, acl_maxcnt), &am);
186 if (am != ACL_MAX_ENTRIES)
189 error = copyout(kernel_acl, user_acl, sizeof(*kernel_acl));
196 * Convert "old" type - ACL_TYPE_{ACCESS,DEFAULT}_OLD - into its "new"
197 * counterpart. It's required for old (pre-NFSv4 ACLs) libc to work
198 * with new kernel. Fixing 'type' for old binaries with new libc
199 * is being done in lib/libc/posix1e/acl_support.c:_acl_type_unold().
202 acl_type_unold(int type)
205 case ACL_TYPE_ACCESS_OLD:
206 return (ACL_TYPE_ACCESS);
208 case ACL_TYPE_DEFAULT_OLD:
209 return (ACL_TYPE_DEFAULT);
217 * These calls wrap the real vnode operations, and are called by the syscall
218 * code once the syscall has converted the path or file descriptor to a vnode
219 * (unlocked). The aclp pointer is assumed still to point to userland, so
220 * this should not be consumed within the kernel except by syscall code.
221 * Other code should directly invoke VOP_{SET,GET}ACL.
225 * Given a vnode, set its ACL.
228 vacl_set_acl(struct thread *td, struct vnode *vp, acl_type_t type,
229 const struct acl *aclp)
231 struct acl *inkernelacl;
235 AUDIT_ARG_VALUE(type);
236 inkernelacl = acl_alloc(M_WAITOK);
237 error = acl_copyin(aclp, inkernelacl, type);
240 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
243 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
244 AUDIT_ARG_VNODE1(vp);
246 error = mac_vnode_check_setacl(td->td_ucred, vp, type, inkernelacl);
250 error = VOP_SETACL(vp, acl_type_unold(type), inkernelacl,
256 vn_finished_write(mp);
258 acl_free(inkernelacl);
263 * Given a vnode, get its ACL.
266 vacl_get_acl(struct thread *td, struct vnode *vp, acl_type_t type,
269 struct acl *inkernelacl;
272 AUDIT_ARG_VALUE(type);
273 inkernelacl = acl_alloc(M_WAITOK | M_ZERO);
274 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
275 AUDIT_ARG_VNODE1(vp);
277 error = mac_vnode_check_getacl(td->td_ucred, vp, type);
281 error = VOP_GETACL(vp, acl_type_unold(type), inkernelacl,
289 error = acl_copyout(inkernelacl, aclp, type);
290 acl_free(inkernelacl);
295 * Given a vnode, delete its ACL.
298 vacl_delete(struct thread *td, struct vnode *vp, acl_type_t type)
303 AUDIT_ARG_VALUE(type);
304 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
307 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
308 AUDIT_ARG_VNODE1(vp);
310 error = mac_vnode_check_deleteacl(td->td_ucred, vp, type);
314 error = VOP_SETACL(vp, acl_type_unold(type), 0, td->td_ucred, td);
319 vn_finished_write(mp);
324 * Given a vnode, check whether an ACL is appropriate for it
326 * XXXRW: No vnode lock held so can't audit vnode state...?
329 vacl_aclcheck(struct thread *td, struct vnode *vp, acl_type_t type,
330 const struct acl *aclp)
332 struct acl *inkernelacl;
335 inkernelacl = acl_alloc(M_WAITOK);
336 error = acl_copyin(aclp, inkernelacl, type);
339 error = VOP_ACLCHECK(vp, acl_type_unold(type), inkernelacl,
342 acl_free(inkernelacl);
347 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. Don't
348 * need to lock, as the vacl_ code will get/release any locks required.
352 * Given a file path, get an ACL for it
355 sys___acl_get_file(struct thread *td, struct __acl_get_file_args *uap)
358 return (kern___acl_get_path(td, uap->path, 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)
369 return(kern___acl_get_path(td, uap->path, uap->type, uap->aclp,
374 kern___acl_get_path(struct thread *td, const char *path, acl_type_t type,
375 struct acl *aclp, int follow)
380 NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, UIO_USERSPACE, path, td);
383 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, td);
421 error = vacl_set_acl(td, nd.ni_vp, type, aclp);
428 * Given a file descriptor, get an ACL for it.
431 sys___acl_get_fd(struct thread *td, struct __acl_get_fd_args *uap)
437 AUDIT_ARG_FD(uap->filedes);
438 error = getvnode(td, uap->filedes,
439 cap_rights_init_one(&rights, CAP_ACL_GET), &fp);
441 error = vacl_get_acl(td, fp->f_vnode, uap->type, uap->aclp);
448 * Given a file descriptor, set an ACL for it.
451 sys___acl_set_fd(struct thread *td, struct __acl_set_fd_args *uap)
457 AUDIT_ARG_FD(uap->filedes);
458 error = getvnode(td, uap->filedes,
459 cap_rights_init_one(&rights, CAP_ACL_SET), &fp);
461 error = vacl_set_acl(td, fp->f_vnode, uap->type, uap->aclp);
468 * Given a file path, delete an ACL from it.
471 sys___acl_delete_file(struct thread *td, struct __acl_delete_file_args *uap)
474 return (kern___acl_delete_path(td, uap->path, uap->type, FOLLOW));
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)
484 return (kern___acl_delete_path(td, uap->path, uap->type, NOFOLLOW));
488 kern___acl_delete_path(struct thread *td, const char *path,
489 acl_type_t type, int follow)
494 NDINIT(&nd, LOOKUP, follow, UIO_USERSPACE, path, td);
497 error = vacl_delete(td, nd.ni_vp, type);
504 * Given a file path, delete an ACL from it.
507 sys___acl_delete_fd(struct thread *td, struct __acl_delete_fd_args *uap)
513 AUDIT_ARG_FD(uap->filedes);
514 error = getvnode(td, uap->filedes,
515 cap_rights_init_one(&rights, CAP_ACL_DELETE), &fp);
517 error = vacl_delete(td, fp->f_vnode, uap->type);
524 * Given a file path, check an ACL for it.
527 sys___acl_aclcheck_file(struct thread *td, struct __acl_aclcheck_file_args *uap)
530 return (kern___acl_aclcheck_path(td, uap->path, uap->type, uap->aclp,
535 * Given a file path, check an ACL for it; don't follow links.
538 sys___acl_aclcheck_link(struct thread *td, struct __acl_aclcheck_link_args *uap)
540 return (kern___acl_aclcheck_path(td, uap->path, uap->type, uap->aclp,
545 kern___acl_aclcheck_path(struct thread *td, const char *path, acl_type_t type,
546 struct acl *aclp, int follow)
551 NDINIT(&nd, LOOKUP, follow, UIO_USERSPACE, path, td);
554 error = vacl_aclcheck(td, nd.ni_vp, type, aclp);
561 * Given a file descriptor, check an ACL for it.
564 sys___acl_aclcheck_fd(struct thread *td, struct __acl_aclcheck_fd_args *uap)
570 AUDIT_ARG_FD(uap->filedes);
571 error = getvnode(td, uap->filedes,
572 cap_rights_init_one(&rights, CAP_ACL_CHECK), &fp);
574 error = vacl_aclcheck(td, fp->f_vnode, uap->type, uap->aclp);
585 aclp = malloc(sizeof(*aclp), M_ACL, flags);
589 aclp->acl_maxcnt = ACL_MAX_ENTRIES;
595 acl_free(struct acl *aclp)