xref: /dragonfly/lib/libposix1e/acl_from_text.c (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)
1 /*-
2  * Copyright (c) 1999 Robert N. M. Watson
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  *$FreeBSD: src/lib/libposix1e/acl_from_text.c,v 1.1 2000/01/15 19:44:24 rwatson Exp $
27  *$DragonFly: src/lib/libposix1e/acl_from_text.c,v 1.3 2005/08/04 17:27:09 drhodus Exp $
28  */
29 /*
30  * acl_from_text: convert a text-form ACL from a string to an acl_t
31  */
32 
33 #include <sys/types.h>
34 #include <sys/acl.h>
35 #include <sys/errno.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 
40 #include "acl_support.h"
41 
42 enum PARSE_MODE {
43           PM_BASE,            /* initial, begin line, or after , */
44           PM_QUALIFIER,                 /* in qualifier field */
45           PM_PERM,            /* in permission field */
46           PM_COMMENT,                   /* in comment */
47 };
48 
49 static char *
string_skip_whitespace(char * string)50 string_skip_whitespace(char *string)
51 {
52 
53           while (*string && ((*string == ' ') || (*string == '\t'))) {
54                     string++;
55           }
56           return (string);
57 }
58 
59 static void
string_trim_trailing_whitespace(char * string)60 string_trim_trailing_whitespace(char *string)
61 {
62           char      *end;
63 
64           if (*string == '\0')
65                     return;
66 
67           end = string + strlen(string) - 1;
68 
69           while (end != string) {
70                     if ((*end == ' ') || (*end == '\t')) {
71                               *end = '\0';
72                               end--;
73                     } else {
74                               return;
75                     }
76           }
77 
78           return;
79 }
80 
81 acl_tag_t
acl_string_to_tag(char * tag,char * qualifier)82 acl_string_to_tag(char *tag, char *qualifier)
83 {
84 
85           if (*qualifier == '\0') {
86                     if ((!strcmp(tag, "user")) || (!strcmp(tag, "u"))) {
87                               return (ACL_USER_OBJ);
88                     } else
89                     if ((!strcmp(tag, "group")) || (!strcmp(tag, "g"))) {
90                               return (ACL_GROUP_OBJ);
91                     } else
92                     if ((!strcmp(tag, "mask")) || (!strcmp(tag, "m"))) {
93                               return (ACL_MASK);
94                     } else
95                     if ((!strcmp(tag, "other")) || (!strcmp(tag, "o"))) {
96                               return (ACL_OTHER);
97                     } else
98                               return(-1);
99           } else {
100                     if ((!strcmp(tag, "user")) || (!strcmp(tag, "u"))) {
101                               return(ACL_USER);
102                     } else
103                     if ((!strcmp(tag, "group")) || (!strcmp(tag, "g"))) {
104                               return(ACL_GROUP);
105                     } else
106                               return(-1);
107           }
108 }
109 
110 /*
111  * acl_from_text -- convert a string into an ACL
112  * postpone most validity checking until the end and cal acl_valid to do
113  * that.
114  */
115 acl_t
acl_from_text(const char * buf_p)116 acl_from_text(const char *buf_p)
117 {
118           acl_tag_t t;
119           acl_perm_t          p;
120           acl_t     acl;
121           uid_t     id;
122           char      *mybuf_p, *line, *cur, *notcomment, *comment, *entry;
123           char      *tag, *qualifier, *permission;
124           int       error;
125 
126           /* local copy we can mess up */
127           mybuf_p = strdup(buf_p);
128           if (!mybuf_p) {
129                     errno = ENOMEM;
130                     return(0);
131           }
132 
133           acl = acl_init(3);
134           if (!acl) {
135                     free(mybuf_p);
136                     errno = ENOMEM;
137                     return(0);
138           }
139 
140           /* outer loop: delimit at \n boundaries */
141           cur = mybuf_p;
142           while ((line = strsep(&cur, "\n"))) {
143                     /* now split the line on the first # to strip out comments */
144                     comment = line;
145                     notcomment = strsep(&comment, "#");
146 
147                     /* inner loop: delimit at , boundaries */
148                     while ((entry = strsep(&notcomment, ","))) {
149                               /* now split into three :-delimited fields */
150                               tag = strsep(&entry, ":");
151                               if (!tag) {
152                                         /* printf("no tag\n"); */
153                                         errno = EINVAL;
154                                         goto error_label;
155                               }
156                               tag = string_skip_whitespace(tag);
157                               if ((*tag == '\0') && (!entry)) {
158                                         /*
159                                          * is an entirely comment line, skip to next
160                                          * comma
161                                          */
162                                         continue;
163                               }
164                               string_trim_trailing_whitespace(tag);
165 
166                               qualifier = strsep(&entry, ":");
167                               if (!qualifier) {
168                                         /* printf("no qualifier\n"); */
169                                         errno = EINVAL;
170                                         goto error_label;
171                               }
172                               qualifier = string_skip_whitespace(qualifier);
173                               string_trim_trailing_whitespace(qualifier);
174 
175                               permission = strsep(&entry, ":");
176                               if ((!permission) || (entry)) {
177                                         /* printf("no permission, or more stuff\n"); */
178                                         errno = EINVAL;
179                                         goto error_label;
180                               }
181                               permission = string_skip_whitespace(permission);
182                               string_trim_trailing_whitespace(permission);
183 
184                               /* printf("[%s/%s/%s]\n", tag, qualifier,
185                                   permission); */
186 
187                               t = acl_string_to_tag(tag, qualifier);
188                               if (t == -1) {
189                                         errno = EINVAL;
190                                         goto error_label;
191                               }
192 
193                               error = acl_string_to_perm(permission, &p);
194                               if (error == -1) {
195                                         errno = EINVAL;
196                                         goto error_label;
197                               }
198 
199                               switch(t) {
200                               case ACL_USER_OBJ:
201                               case ACL_GROUP_OBJ:
202                               case ACL_MASK:
203                               case ACL_OTHER:
204                                         if (*qualifier != '\0') {
205                                                   errno = EINVAL;
206                                                   goto error_label;
207                                         }
208                                         id = 0;
209                                         break;
210 
211                               case ACL_USER:
212                               case ACL_GROUP:
213                                         error = acl_name_to_id(t, qualifier, &id);
214                                         if (error == -1)
215                                                   goto error_label;
216                                         break;
217 
218                               default:
219                                         errno = EINVAL;
220                                         goto error_label;
221                               }
222 
223                               error = acl_add_entry(acl, t, id, p);
224                               if (error == -1)
225                                         goto error_label;
226                     }
227           }
228 
229 #if 0
230           /* XXX should we only return ACLs valid according to acl_valid? */
231           /* verify validity of the ACL we read in */
232           if (acl_valid(acl) == -1) {
233                     errno = EINVAL;
234                     goto error_label;
235           }
236 #endif
237 
238           return(acl);
239 
240 error_label:
241           acl_free(acl);
242           free(mybuf_p);
243           return(0);
244 }
245 
246 
247 
248