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      1 /*-
      2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      3  *
      4  * Copyright (c) 1999, 2000, 2001 Robert N. M. Watson
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 /*
     29  * acl_from_text: Convert a text-form ACL from a string to an acl_t.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #if 0
     34 __FBSDID("$FreeBSD: head/lib/libc/posix1e/acl_from_text.c 326193 2017-11-25 17:12:48Z pfg $");
     35 #else
     36 __RCSID("$NetBSD: acl_from_text.c,v 1.2 2024/01/20 14:52:48 christos Exp $");
     37 #endif
     38 
     39 #include "namespace.h"
     40 #include <sys/types.h>
     41 #include <sys/acl.h>
     42 #include <errno.h>
     43 #include <grp.h>
     44 #include <pwd.h>
     45 #include <stdio.h>
     46 #include <stdlib.h>
     47 #include <string.h>
     48 #include <assert.h>
     49 
     50 #include "acl_support.h"
     51 
     52 static acl_tag_t acl_string_to_tag(char *tag, char *qualifier);
     53 
     54 static acl_tag_t
     55 acl_string_to_tag(char *tag, char *qualifier)
     56 {
     57 
     58 	if (*qualifier == '\0') {
     59 		if ((!strcmp(tag, "user")) || (!strcmp(tag, "u"))) {
     60 			return (ACL_USER_OBJ);
     61 		} else
     62 		if ((!strcmp(tag, "group")) || (!strcmp(tag, "g"))) {
     63 			return (ACL_GROUP_OBJ);
     64 		} else
     65 		if ((!strcmp(tag, "mask")) || (!strcmp(tag, "m"))) {
     66 			return (ACL_MASK);
     67 		} else
     68 		if ((!strcmp(tag, "other")) || (!strcmp(tag, "o"))) {
     69 			return (ACL_OTHER);
     70 		} else
     71 			return((acl_tag_t)-1);
     72 	} else {
     73 		if ((!strcmp(tag, "user")) || (!strcmp(tag, "u"))) {
     74 			return(ACL_USER);
     75 		} else
     76 		if ((!strcmp(tag, "group")) || (!strcmp(tag, "g"))) {
     77 			return(ACL_GROUP);
     78 		} else
     79 			return((acl_tag_t)-1);
     80 	}
     81 }
     82 
     83 static int
     84 _posix1e_acl_entry_from_text(acl_t aclp, char *entry)
     85 {
     86 	acl_tag_t	 t;
     87 	acl_perm_t	 p;
     88 	char		*tag, *qualifier, *permission;
     89 	uid_t		 id;
     90 	int		 error;
     91 
     92 	assert(_acl_brand(aclp) == ACL_BRAND_POSIX);
     93 
     94 	/* Split into three ':' delimited fields. */
     95 	tag = strsep(&entry, ":");
     96 	if (tag == NULL) {
     97 		errno = EINVAL;
     98 		return (-1);
     99 	}
    100 	tag = string_skip_whitespace(tag);
    101 	if ((*tag == '\0') && (!entry)) {
    102 		/*
    103 		 * Is an entirely comment line, skip to next
    104 		 * comma.
    105 		 */
    106 		return (0);
    107 	}
    108 	string_trim_trailing_whitespace(tag);
    109 
    110 	qualifier = strsep(&entry, ":");
    111 	if (qualifier == NULL) {
    112 		errno = EINVAL;
    113 		return (-1);
    114 	}
    115 	qualifier = string_skip_whitespace(qualifier);
    116 	string_trim_trailing_whitespace(qualifier);
    117 
    118 	permission = strsep(&entry, ":");
    119 	if (permission == NULL || entry) {
    120 		errno = EINVAL;
    121 		return (-1);
    122 	}
    123 	permission = string_skip_whitespace(permission);
    124 	string_trim_trailing_whitespace(permission);
    125 
    126 	t = acl_string_to_tag(tag, qualifier);
    127 	if (t == (acl_tag_t)-1) {
    128 		errno = EINVAL;
    129 		return (-1);
    130 	}
    131 
    132 	error = _posix1e_acl_string_to_perm(permission, &p);
    133 	if (error == -1) {
    134 		errno = EINVAL;
    135 		return (-1);
    136 	}
    137 
    138 	switch(t) {
    139 		case ACL_USER_OBJ:
    140 		case ACL_GROUP_OBJ:
    141 		case ACL_MASK:
    142 		case ACL_OTHER:
    143 			if (*qualifier != '\0') {
    144 				errno = EINVAL;
    145 				return (-1);
    146 			}
    147 			id = 0;
    148 			break;
    149 
    150 		case ACL_USER:
    151 		case ACL_GROUP:
    152 			error = _acl_name_to_id(t, qualifier, &id);
    153 			if (error == -1)
    154 				return (-1);
    155 			break;
    156 
    157 		default:
    158 			errno = EINVAL;
    159 			return (-1);
    160 	}
    161 
    162 	error = _posix1e_acl_add_entry(aclp, t, id, p);
    163 	if (error == -1)
    164 		return (-1);
    165 
    166 	return (0);
    167 }
    168 
    169 static int
    170 _text_is_nfs4_entry(const char *entry)
    171 {
    172 	int count = 0;
    173 
    174 	assert(strlen(entry) > 0);
    175 
    176 	while (*entry != '\0') {
    177 		if (*entry == ':' || *entry == '@')
    178 			count++;
    179 		entry++;
    180 	}
    181 
    182 	if (count <= 2)
    183 		return (0);
    184 
    185 	return (1);
    186 }
    187 
    188 /*
    189  * acl_from_text -- Convert a string into an ACL.
    190  * Postpone most validity checking until the end and call acl_valid() to do
    191  * that.
    192  */
    193 acl_t
    194 acl_from_text(const char *buf_p)
    195 {
    196 	acl_t		 acl;
    197 	char		*mybuf_p, *line, *cur, *notcomment, *comment, *entry;
    198 	int		 error;
    199 
    200 	/* Local copy we can mess up. */
    201 	mybuf_p = strdup(buf_p);
    202 	if (mybuf_p == NULL)
    203 		return(NULL);
    204 
    205 	acl = acl_init(3); /* XXX: WTF, 3? */
    206 	if (acl == NULL) {
    207 		free(mybuf_p);
    208 		return(NULL);
    209 	}
    210 
    211 	/* Outer loop: delimit at \n boundaries. */
    212 	cur = mybuf_p;
    213 	while ((line = strsep(&cur, "\n"))) {
    214 		/* Now split the line on the first # to strip out comments. */
    215 		comment = line;
    216 		notcomment = strsep(&comment, "#");
    217 
    218 		/* Inner loop: delimit at ',' boundaries. */
    219 		while ((entry = strsep(&notcomment, ","))) {
    220 
    221 			/* Skip empty lines. */
    222 			if (strlen(string_skip_whitespace(entry)) == 0)
    223 				continue;
    224 
    225 			if (_acl_brand(acl) == ACL_BRAND_UNKNOWN) {
    226 				if (_text_is_nfs4_entry(entry))
    227 					_acl_brand_as(acl, ACL_BRAND_NFS4);
    228 				else
    229 					_acl_brand_as(acl, ACL_BRAND_POSIX);
    230 			}
    231 
    232 			switch (_acl_brand(acl)) {
    233 			case ACL_BRAND_NFS4:
    234 				error = _nfs4_acl_entry_from_text(acl, entry);
    235 				break;
    236 
    237 			case ACL_BRAND_POSIX:
    238 				error = _posix1e_acl_entry_from_text(acl, entry);
    239 				break;
    240 
    241 			default:
    242 				error = EINVAL;
    243 				break;
    244 			}
    245 
    246 			if (error)
    247 				goto error_label;
    248 		}
    249 	}
    250 
    251 #if 0
    252 	/* XXX Should we only return ACLs valid according to acl_valid? */
    253 	/* Verify validity of the ACL we read in. */
    254 	if (acl_valid(acl) == -1) {
    255 		errno = EINVAL;
    256 		goto error_label;
    257 	}
    258 #endif
    259 
    260 	free(mybuf_p);
    261 	return(acl);
    262 
    263 error_label:
    264 	acl_free(acl);
    265 	free(mybuf_p);
    266 	return(NULL);
    267 }
    268 
    269 /*
    270  * Given a username/groupname from a text form of an ACL, return the uid/gid
    271  * XXX NOT THREAD SAFE, RELIES ON GETPWNAM, GETGRNAM
    272  * XXX USES *PW* AND *GR* WHICH ARE STATEFUL AND THEREFORE THIS ROUTINE
    273  * MAY HAVE SIDE-EFFECTS
    274  */
    275 int
    276 _acl_name_to_id(acl_tag_t tag, char *name, uid_t *id)
    277 {
    278 	struct group	*g;
    279 	struct passwd	*p;
    280 	unsigned long	l;
    281 	char 		*endp;
    282 
    283 	switch(tag) {
    284 	case ACL_USER:
    285 		p = getpwnam(name);
    286 		if (p == NULL) {
    287 			l = strtoul(name, &endp, 0);
    288 			if (*endp != '\0' || l != (unsigned long)(uid_t)l) {
    289 				errno = EINVAL;
    290 				return (-1);
    291 			}
    292 			*id = (uid_t)l;
    293 			return (0);
    294 		}
    295 		*id = p->pw_uid;
    296 		return (0);
    297 
    298 	case ACL_GROUP:
    299 		g = getgrnam(name);
    300 		if (g == NULL) {
    301 			l = strtoul(name, &endp, 0);
    302 			if (*endp != '\0' || l != (unsigned long)(gid_t)l) {
    303 				errno = EINVAL;
    304 				return (-1);
    305 			}
    306 			*id = (gid_t)l;
    307 			return (0);
    308 		}
    309 		*id = g->gr_gid;
    310 		return (0);
    311 
    312 	default:
    313 		return (EINVAL);
    314 	}
    315 }
    316