xref: /freebsd/lib/libc/posix1e/acl_strip.c (revision d915a14ef094c8dfc1a5aee70e135abfec01d0f1) 
1aa015c8eSEdward Tomasz Napierala /*-
2*d915a14eSPedro F. Giffuni  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3*d915a14eSPedro F. Giffuni  *
4aa015c8eSEdward Tomasz Napierala  * Copyright (c) 2001 Chris D. Faulhaber
5aa015c8eSEdward Tomasz Napierala  * All rights reserved.
6aa015c8eSEdward Tomasz Napierala  *
7aa015c8eSEdward Tomasz Napierala  * Redistribution and use in source and binary forms, with or without
8aa015c8eSEdward Tomasz Napierala  * modification, are permitted provided that the following conditions
9aa015c8eSEdward Tomasz Napierala  * are met:
10aa015c8eSEdward Tomasz Napierala  * 1. Redistributions of source code must retain the above copyright
11aa015c8eSEdward Tomasz Napierala  *    notice, this list of conditions and the following disclaimer.
12aa015c8eSEdward Tomasz Napierala  * 2. Redistributions in binary form must reproduce the above copyright
13aa015c8eSEdward Tomasz Napierala  *    notice, this list of conditions and the following disclaimer in the
14aa015c8eSEdward Tomasz Napierala  *    documentation and/or other materials provided with the distribution.
15aa015c8eSEdward Tomasz Napierala  *
16aa015c8eSEdward Tomasz Napierala  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17aa015c8eSEdward Tomasz Napierala  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18aa015c8eSEdward Tomasz Napierala  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19a303eae7SJoel Dahl  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20a303eae7SJoel Dahl  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21a303eae7SJoel Dahl  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22a303eae7SJoel Dahl  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23a303eae7SJoel Dahl  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24a303eae7SJoel Dahl  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25a303eae7SJoel Dahl  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26a303eae7SJoel Dahl  * SUCH DAMAGE.
27aa015c8eSEdward Tomasz Napierala  */
28aa015c8eSEdward Tomasz Napierala 
29aa015c8eSEdward Tomasz Napierala #include <sys/cdefs.h>
30aa015c8eSEdward Tomasz Napierala __FBSDID("$FreeBSD$");
31aa015c8eSEdward Tomasz Napierala 
32aa015c8eSEdward Tomasz Napierala #include <errno.h>
33aa015c8eSEdward Tomasz Napierala #include <stdio.h>
34aa015c8eSEdward Tomasz Napierala #include <assert.h>
35aa015c8eSEdward Tomasz Napierala #include <sys/acl.h>
364089cc8aSEdward Tomasz Napierala #include <sys/stat.h>
37aa015c8eSEdward Tomasz Napierala 
38aa015c8eSEdward Tomasz Napierala #include "acl_support.h"
39aa015c8eSEdward Tomasz Napierala 
40aa015c8eSEdward Tomasz Napierala /*
41cdec3856SEdward Tomasz Napierala  * These routines from sys/kern/subr_acl_nfs4.c are used by both kernel
42aa015c8eSEdward Tomasz Napierala  * and libc.
43aa015c8eSEdward Tomasz Napierala  */
44aa015c8eSEdward Tomasz Napierala void	acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp);
45cdec3856SEdward Tomasz Napierala void	acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int file_owner_id,
46cdec3856SEdward Tomasz Napierala 	    int canonical_six);
47aa015c8eSEdward Tomasz Napierala 
48aa015c8eSEdward Tomasz Napierala static acl_t
494089cc8aSEdward Tomasz Napierala _nfs4_acl_strip_np(const acl_t aclp, int canonical_six)
50aa015c8eSEdward Tomasz Napierala {
51aa015c8eSEdward Tomasz Napierala 	acl_t newacl;
527945d60dSEdward Tomasz Napierala 	mode_t mode = 0;
53aa015c8eSEdward Tomasz Napierala 
54aa015c8eSEdward Tomasz Napierala 	newacl = acl_init(ACL_MAX_ENTRIES);
55aa015c8eSEdward Tomasz Napierala 	if (newacl == NULL) {
56aa015c8eSEdward Tomasz Napierala 		errno = ENOMEM;
57aa015c8eSEdward Tomasz Napierala 		return (NULL);
58aa015c8eSEdward Tomasz Napierala 	}
59aa015c8eSEdward Tomasz Napierala 
60aa015c8eSEdward Tomasz Napierala 	_acl_brand_as(newacl, ACL_BRAND_NFS4);
61aa015c8eSEdward Tomasz Napierala 
62aa015c8eSEdward Tomasz Napierala 	acl_nfs4_sync_mode_from_acl(&mode, &(aclp->ats_acl));
63cdec3856SEdward Tomasz Napierala 	acl_nfs4_trivial_from_mode_libc(&(newacl->ats_acl), mode, canonical_six);
64aa015c8eSEdward Tomasz Napierala 
65aa015c8eSEdward Tomasz Napierala 	return (newacl);
66aa015c8eSEdward Tomasz Napierala }
67aa015c8eSEdward Tomasz Napierala 
68aa015c8eSEdward Tomasz Napierala static acl_t
69aa015c8eSEdward Tomasz Napierala _posix1e_acl_strip_np(const acl_t aclp, int recalculate_mask)
70aa015c8eSEdward Tomasz Napierala {
71aa015c8eSEdward Tomasz Napierala 	acl_t acl_new, acl_old;
72aa015c8eSEdward Tomasz Napierala 	acl_entry_t entry, entry_new;
73aa015c8eSEdward Tomasz Napierala 	acl_permset_t perm;
74aa015c8eSEdward Tomasz Napierala 	acl_tag_t tag;
75aa015c8eSEdward Tomasz Napierala 	int entry_id, have_mask_entry;
76aa015c8eSEdward Tomasz Napierala 
77aa015c8eSEdward Tomasz Napierala 	assert(_acl_brand(aclp) == ACL_BRAND_POSIX);
78aa015c8eSEdward Tomasz Napierala 
79aa015c8eSEdward Tomasz Napierala 	acl_old = acl_dup(aclp);
80aa015c8eSEdward Tomasz Napierala 	if (acl_old == NULL)
81aa015c8eSEdward Tomasz Napierala 		return (NULL);
82aa015c8eSEdward Tomasz Napierala 
83aa015c8eSEdward Tomasz Napierala 	assert(_acl_brand(acl_old) == ACL_BRAND_POSIX);
84aa015c8eSEdward Tomasz Napierala 
85aa015c8eSEdward Tomasz Napierala 	have_mask_entry = 0;
86aa015c8eSEdward Tomasz Napierala 	acl_new = acl_init(ACL_MAX_ENTRIES);
87cf0f0b80SPedro F. Giffuni 	if (acl_new == NULL) {
88cf0f0b80SPedro F. Giffuni 		acl_free(acl_old);
89aa015c8eSEdward Tomasz Napierala 		return (NULL);
90cf0f0b80SPedro F. Giffuni 	}
91aa015c8eSEdward Tomasz Napierala 	tag = ACL_UNDEFINED_TAG;
92aa015c8eSEdward Tomasz Napierala 
93aa015c8eSEdward Tomasz Napierala 	/* only save the default user/group/other entries */
94aa015c8eSEdward Tomasz Napierala 	entry_id = ACL_FIRST_ENTRY;
95aa015c8eSEdward Tomasz Napierala 	while (acl_get_entry(acl_old, entry_id, &entry) == 1) {
96aa015c8eSEdward Tomasz Napierala 		entry_id = ACL_NEXT_ENTRY;
97aa015c8eSEdward Tomasz Napierala 
98aa015c8eSEdward Tomasz Napierala 		assert(_entry_brand(entry) == ACL_BRAND_POSIX);
99aa015c8eSEdward Tomasz Napierala 
100aa015c8eSEdward Tomasz Napierala 		if (acl_get_tag_type(entry, &tag) == -1)
101cf0f0b80SPedro F. Giffuni 			goto fail;
102aa015c8eSEdward Tomasz Napierala 
103aa015c8eSEdward Tomasz Napierala 		switch(tag) {
104aa015c8eSEdward Tomasz Napierala 		case ACL_USER_OBJ:
105aa015c8eSEdward Tomasz Napierala 		case ACL_GROUP_OBJ:
106aa015c8eSEdward Tomasz Napierala 		case ACL_OTHER:
107aa015c8eSEdward Tomasz Napierala 			if (acl_get_tag_type(entry, &tag) == -1)
108cf0f0b80SPedro F. Giffuni 				goto fail;
109aa015c8eSEdward Tomasz Napierala 			if (acl_get_permset(entry, &perm) == -1)
110cf0f0b80SPedro F. Giffuni 				goto fail;
111aa015c8eSEdward Tomasz Napierala 			if (acl_create_entry(&acl_new, &entry_new) == -1)
1128e6acc53SEdward Tomasz Napierala 				goto fail;
113aa015c8eSEdward Tomasz Napierala 			if (acl_set_tag_type(entry_new, tag) == -1)
1148e6acc53SEdward Tomasz Napierala 				goto fail;
115aa015c8eSEdward Tomasz Napierala 			if (acl_set_permset(entry_new, perm) == -1)
1168e6acc53SEdward Tomasz Napierala 				goto fail;
117aa015c8eSEdward Tomasz Napierala 			if (acl_copy_entry(entry_new, entry) == -1)
1188e6acc53SEdward Tomasz Napierala 				goto fail;
119aa015c8eSEdward Tomasz Napierala 			assert(_entry_brand(entry_new) == ACL_BRAND_POSIX);
120aa015c8eSEdward Tomasz Napierala 			break;
121aa015c8eSEdward Tomasz Napierala 		case ACL_MASK:
122aa015c8eSEdward Tomasz Napierala 			have_mask_entry = 1;
123aa015c8eSEdward Tomasz Napierala 			break;
124aa015c8eSEdward Tomasz Napierala 		default:
125aa015c8eSEdward Tomasz Napierala 			break;
126aa015c8eSEdward Tomasz Napierala 		}
127aa015c8eSEdward Tomasz Napierala 	}
128aa015c8eSEdward Tomasz Napierala 
129aa015c8eSEdward Tomasz Napierala 	assert(_acl_brand(acl_new) == ACL_BRAND_POSIX);
130aa015c8eSEdward Tomasz Napierala 
131aa015c8eSEdward Tomasz Napierala 	if (have_mask_entry && recalculate_mask) {
132aa015c8eSEdward Tomasz Napierala 		if (acl_calc_mask(&acl_new) == -1)
1338e6acc53SEdward Tomasz Napierala 			goto fail;
134aa015c8eSEdward Tomasz Napierala 	}
135aa015c8eSEdward Tomasz Napierala 
136aa015c8eSEdward Tomasz Napierala 	return (acl_new);
1378e6acc53SEdward Tomasz Napierala 
1388e6acc53SEdward Tomasz Napierala fail:
1398e6acc53SEdward Tomasz Napierala 	acl_free(acl_new);
1408e6acc53SEdward Tomasz Napierala 	acl_free(acl_old);
1418e6acc53SEdward Tomasz Napierala 
1428e6acc53SEdward Tomasz Napierala 	return (NULL);
143aa015c8eSEdward Tomasz Napierala }
144aa015c8eSEdward Tomasz Napierala 
145aa015c8eSEdward Tomasz Napierala acl_t
146aa015c8eSEdward Tomasz Napierala acl_strip_np(const acl_t aclp, int recalculate_mask)
147aa015c8eSEdward Tomasz Napierala {
148aa015c8eSEdward Tomasz Napierala 	switch (_acl_brand(aclp)) {
149aa015c8eSEdward Tomasz Napierala 	case ACL_BRAND_NFS4:
150e43af6d3SEdward Tomasz Napierala 		return (_nfs4_acl_strip_np(aclp, 0));
151aa015c8eSEdward Tomasz Napierala 
152aa015c8eSEdward Tomasz Napierala 	case ACL_BRAND_POSIX:
153aa015c8eSEdward Tomasz Napierala 		return (_posix1e_acl_strip_np(aclp, recalculate_mask));
154aa015c8eSEdward Tomasz Napierala 
155aa015c8eSEdward Tomasz Napierala 	default:
156aa015c8eSEdward Tomasz Napierala 		errno = EINVAL;
157aa015c8eSEdward Tomasz Napierala 		return (NULL);
158aa015c8eSEdward Tomasz Napierala 	}
159aa015c8eSEdward Tomasz Napierala }
160aa015c8eSEdward Tomasz Napierala 
161aa015c8eSEdward Tomasz Napierala /*
162aa015c8eSEdward Tomasz Napierala  * Return 1, if ACL is trivial, 0 otherwise.
163aa015c8eSEdward Tomasz Napierala  *
164aa015c8eSEdward Tomasz Napierala  * ACL is trivial, iff its meaning could be fully expressed using just file
165aa015c8eSEdward Tomasz Napierala  * mode.  In other words, ACL is trivial iff it doesn't have "+" to the right
166aa015c8eSEdward Tomasz Napierala  * of the mode bits in "ls -l" output ;-)
167aa015c8eSEdward Tomasz Napierala  */
168aa015c8eSEdward Tomasz Napierala int
169aa015c8eSEdward Tomasz Napierala acl_is_trivial_np(const acl_t aclp, int *trivialp)
170aa015c8eSEdward Tomasz Napierala {
171aa015c8eSEdward Tomasz Napierala 	acl_t tmpacl;
172aa015c8eSEdward Tomasz Napierala 	int differs;
173aa015c8eSEdward Tomasz Napierala 
174aa015c8eSEdward Tomasz Napierala 	if (aclp == NULL || trivialp == NULL) {
175aa015c8eSEdward Tomasz Napierala 		errno = EINVAL;
176aa015c8eSEdward Tomasz Napierala 		return (-1);
177aa015c8eSEdward Tomasz Napierala 	}
178aa015c8eSEdward Tomasz Napierala 
179aa015c8eSEdward Tomasz Napierala 	switch (_acl_brand(aclp)) {
180aa015c8eSEdward Tomasz Napierala 	case ACL_BRAND_POSIX:
181aa015c8eSEdward Tomasz Napierala 		if (aclp->ats_acl.acl_cnt == 3)
182aa015c8eSEdward Tomasz Napierala 			*trivialp = 1;
183aa015c8eSEdward Tomasz Napierala 		else
184aa015c8eSEdward Tomasz Napierala 			*trivialp = 0;
185aa015c8eSEdward Tomasz Napierala 
186aa015c8eSEdward Tomasz Napierala 		return (0);
187aa015c8eSEdward Tomasz Napierala 
188aa015c8eSEdward Tomasz Napierala 	case ACL_BRAND_NFS4:
189aa015c8eSEdward Tomasz Napierala 		/*
1907eaa29b5SEdward Tomasz Napierala 		 * If the ACL has more than canonical six entries,
1917eaa29b5SEdward Tomasz Napierala 		 * it's non trivial by definition.
1927eaa29b5SEdward Tomasz Napierala 		 */
1937eaa29b5SEdward Tomasz Napierala 		if (aclp->ats_acl.acl_cnt > 6) {
19478141351SEdward Tomasz Napierala 			*trivialp = 0;
1957eaa29b5SEdward Tomasz Napierala 			return (0);
1967eaa29b5SEdward Tomasz Napierala 		}
1977eaa29b5SEdward Tomasz Napierala 
1987eaa29b5SEdward Tomasz Napierala 		/*
1994089cc8aSEdward Tomasz Napierala 		 * Calculate trivial ACL - using acl_strip_np(3) - and compare
200aa015c8eSEdward Tomasz Napierala 		 * with the original.
201aa015c8eSEdward Tomasz Napierala 		 */
2024089cc8aSEdward Tomasz Napierala 		tmpacl = _nfs4_acl_strip_np(aclp, 0);
2034089cc8aSEdward Tomasz Napierala 		if (tmpacl == NULL)
2044089cc8aSEdward Tomasz Napierala 			return (-1);
2054089cc8aSEdward Tomasz Napierala 
2064089cc8aSEdward Tomasz Napierala 		differs = _acl_differs(aclp, tmpacl);
2074089cc8aSEdward Tomasz Napierala 		acl_free(tmpacl);
2084089cc8aSEdward Tomasz Napierala 
2094089cc8aSEdward Tomasz Napierala 		if (differs == 0) {
2104089cc8aSEdward Tomasz Napierala 			*trivialp = 1;
2114089cc8aSEdward Tomasz Napierala 			return (0);
2124089cc8aSEdward Tomasz Napierala 		}
2134089cc8aSEdward Tomasz Napierala 
2144089cc8aSEdward Tomasz Napierala 		/*
2154089cc8aSEdward Tomasz Napierala 		 * Try again with an old-style, "canonical six" trivial ACL.
2164089cc8aSEdward Tomasz Napierala 		 */
2174089cc8aSEdward Tomasz Napierala 		tmpacl = _nfs4_acl_strip_np(aclp, 1);
218aa015c8eSEdward Tomasz Napierala 		if (tmpacl == NULL)
219aa015c8eSEdward Tomasz Napierala 			return (-1);
220aa015c8eSEdward Tomasz Napierala 
221aa015c8eSEdward Tomasz Napierala 		differs = _acl_differs(aclp, tmpacl);
222aa015c8eSEdward Tomasz Napierala 		acl_free(tmpacl);
223aa015c8eSEdward Tomasz Napierala 
224aa015c8eSEdward Tomasz Napierala 		if (differs)
225aa015c8eSEdward Tomasz Napierala 			*trivialp = 0;
226aa015c8eSEdward Tomasz Napierala 		else
227aa015c8eSEdward Tomasz Napierala 			*trivialp = 1;
228aa015c8eSEdward Tomasz Napierala 
229aa015c8eSEdward Tomasz Napierala 		return (0);
230aa015c8eSEdward Tomasz Napierala 
231aa015c8eSEdward Tomasz Napierala 	default:
232aa015c8eSEdward Tomasz Napierala 		errno = EINVAL;
233aa015c8eSEdward Tomasz Napierala 		return (-1);
234aa015c8eSEdward Tomasz Napierala 	}
235aa015c8eSEdward Tomasz Napierala }
236