1/*-
2 * Copyright (c) 2001 Chris D. Faulhaber
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <errno.h>
31#include <stdio.h>
32#include <assert.h>
33#include <sys/acl.h>
34#include <sys/stat.h>
35
36#include "acl_support.h"
37
38/*
39 * These routines from sys/kern/subr_acl_nfs4.c are used by both kernel
40 * and libc.
41 */
42void	acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp);
43void	acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int file_owner_id,
44	    int canonical_six);
45
46static acl_t
47_nfs4_acl_strip_np(const acl_t aclp, int canonical_six)
48{
49	acl_t newacl;
50	mode_t mode = 0;
51
52	newacl = acl_init(ACL_MAX_ENTRIES);
53	if (newacl == NULL) {
54		errno = ENOMEM;
55		return (NULL);
56	}
57
58	_acl_brand_as(newacl, ACL_BRAND_NFS4);
59
60	acl_nfs4_sync_mode_from_acl(&mode, &(aclp->ats_acl));
61	acl_nfs4_trivial_from_mode_libc(&(newacl->ats_acl), mode, canonical_six);
62
63	return (newacl);
64}
65
66static acl_t
67_posix1e_acl_strip_np(const acl_t aclp, int recalculate_mask)
68{
69	acl_t acl_new, acl_old;
70	acl_entry_t entry, entry_new;
71	acl_permset_t perm;
72	acl_tag_t tag;
73	int entry_id, have_mask_entry;
74
75	assert(_acl_brand(aclp) == ACL_BRAND_POSIX);
76
77	acl_old = acl_dup(aclp);
78	if (acl_old == NULL)
79		return (NULL);
80
81	assert(_acl_brand(acl_old) == ACL_BRAND_POSIX);
82
83	have_mask_entry = 0;
84	acl_new = acl_init(ACL_MAX_ENTRIES);
85	if (acl_new == NULL) {
86		acl_free(acl_old);
87		return (NULL);
88	}
89	tag = ACL_UNDEFINED_TAG;
90
91	/* only save the default user/group/other entries */
92	entry_id = ACL_FIRST_ENTRY;
93	while (acl_get_entry(acl_old, entry_id, &entry) == 1) {
94		entry_id = ACL_NEXT_ENTRY;
95
96		assert(_entry_brand(entry) == ACL_BRAND_POSIX);
97
98		if (acl_get_tag_type(entry, &tag) == -1)
99			goto fail;
100
101		switch(tag) {
102		case ACL_USER_OBJ:
103		case ACL_GROUP_OBJ:
104		case ACL_OTHER:
105			if (acl_get_tag_type(entry, &tag) == -1)
106				goto fail;
107			if (acl_get_permset(entry, &perm) == -1)
108				goto fail;
109			if (acl_create_entry(&acl_new, &entry_new) == -1)
110				goto fail;
111			if (acl_set_tag_type(entry_new, tag) == -1)
112				goto fail;
113			if (acl_set_permset(entry_new, perm) == -1)
114				goto fail;
115			if (acl_copy_entry(entry_new, entry) == -1)
116				goto fail;
117			assert(_entry_brand(entry_new) == ACL_BRAND_POSIX);
118			break;
119		case ACL_MASK:
120			have_mask_entry = 1;
121			break;
122		default:
123			break;
124		}
125	}
126
127	assert(_acl_brand(acl_new) == ACL_BRAND_POSIX);
128
129	if (have_mask_entry && recalculate_mask) {
130		if (acl_calc_mask(&acl_new) == -1)
131			goto fail;
132	}
133
134	return (acl_new);
135
136fail:
137	acl_free(acl_new);
138	acl_free(acl_old);
139
140	return (NULL);
141}
142
143acl_t
144acl_strip_np(const acl_t aclp, int recalculate_mask)
145{
146	switch (_acl_brand(aclp)) {
147	case ACL_BRAND_NFS4:
148		return (_nfs4_acl_strip_np(aclp, 0));
149
150	case ACL_BRAND_POSIX:
151		return (_posix1e_acl_strip_np(aclp, recalculate_mask));
152
153	default:
154		errno = EINVAL;
155		return (NULL);
156	}
157}
158
159/*
160 * Return 1, if ACL is trivial, 0 otherwise.
161 *
162 * ACL is trivial, iff its meaning could be fully expressed using just file
163 * mode.  In other words, ACL is trivial iff it doesn't have "+" to the right
164 * of the mode bits in "ls -l" output ;-)
165 */
166int
167acl_is_trivial_np(const acl_t aclp, int *trivialp)
168{
169	acl_t tmpacl;
170	int differs;
171
172	if (aclp == NULL || trivialp == NULL) {
173		errno = EINVAL;
174		return (-1);
175	}
176
177	switch (_acl_brand(aclp)) {
178	case ACL_BRAND_POSIX:
179		if (aclp->ats_acl.acl_cnt == 3)
180			*trivialp = 1;
181		else
182			*trivialp = 0;
183
184		return (0);
185
186	case ACL_BRAND_NFS4:
187		/*
188		 * If the ACL has more than canonical six entries,
189		 * it's non trivial by definition.
190		 */
191		if (aclp->ats_acl.acl_cnt > 6) {
192			*trivialp = 0;
193			return (0);
194		}
195
196		/*
197		 * Calculate trivial ACL - using acl_strip_np(3) - and compare
198		 * with the original.
199		 */
200		tmpacl = _nfs4_acl_strip_np(aclp, 0);
201		if (tmpacl == NULL)
202			return (-1);
203
204		differs = _acl_differs(aclp, tmpacl);
205		acl_free(tmpacl);
206
207		if (differs == 0) {
208			*trivialp = 1;
209			return (0);
210		}
211
212		/*
213		 * Try again with an old-style, "canonical six" trivial ACL.
214		 */
215		tmpacl = _nfs4_acl_strip_np(aclp, 1);
216		if (tmpacl == NULL)
217			return (-1);
218
219		differs = _acl_differs(aclp, tmpacl);
220		acl_free(tmpacl);
221
222		if (differs)
223			*trivialp = 0;
224		else
225			*trivialp = 1;
226
227		return (0);
228
229	default:
230		errno = EINVAL;
231		return (-1);
232	}
233}
234