xref: /freebsd/contrib/openbsm/libbsm/bsm_user.c (revision b740c88bfb6453416926271c089262e7164dace3)
1 /*-
2  * Copyright (c) 2004 Apple Inc.
3  * Copyright (c) 2006 Robert N. M. Watson
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1.  Redistributions of source code must retain the above copyright
10  *     notice, this list of conditions and the following disclaimer.
11  * 2.  Redistributions in binary form must reproduce the above copyright
12  *     notice, this list of conditions and the following disclaimer in the
13  *     documentation and/or other materials provided with the distribution.
14  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
15  *     its contributors may be used to endorse or promote products derived
16  *     from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR
22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  *
30  * $P4: //depot/projects/trustedbsd/openbsm/libbsm/bsm_user.c#20 $
31  */
32 
33 #include <config/config.h>
34 
35 #include <bsm/libbsm.h>
36 
37 #include <string.h>
38 #ifdef HAVE_PTHREAD_MUTEX_LOCK
39 #include <pthread.h>
40 #endif
41 #include <stdio.h>
42 #include <stdlib.h>
43 
44 #ifndef HAVE_STRLCPY
45 #include <compat/strlcpy.h>
46 #endif
47 
48 /*
49  * Parse the contents of the audit_user file into au_user_ent structures.
50  */
51 
52 static FILE		*fp = NULL;
53 static char		 linestr[AU_LINE_MAX];
54 static const char	*user_delim = ":";
55 
56 #ifdef HAVE_PTHREAD_MUTEX_LOCK
57 static pthread_mutex_t	mutex = PTHREAD_MUTEX_INITIALIZER;
58 #endif
59 
60 /*
61  * Parse one line from the audit_user file into the au_user_ent structure.
62  */
63 static struct au_user_ent *
64 userfromstr(char *str, struct au_user_ent *u)
65 {
66 	char *username, *always, *never;
67 	char *last;
68 
69 	username = strtok_r(str, user_delim, &last);
70 	always = strtok_r(NULL, user_delim, &last);
71 	never = strtok_r(NULL, user_delim, &last);
72 
73 	if ((username == NULL) || (always == NULL) || (never == NULL))
74 		return (NULL);
75 
76 	if (strlen(username) >= AU_USER_NAME_MAX)
77 		return (NULL);
78 
79 	strlcpy(u->au_name, username, AU_USER_NAME_MAX);
80 	if (getauditflagsbin(always, &(u->au_always)) == -1)
81 		return (NULL);
82 
83 	if (getauditflagsbin(never, &(u->au_never)) == -1)
84 		return (NULL);
85 
86 	return (u);
87 }
88 
89 /*
90  * Rewind to beginning of the file
91  */
92 static void
93 setauuser_locked(void)
94 {
95 
96 	if (fp != NULL)
97 		fseek(fp, 0, SEEK_SET);
98 }
99 
100 void
101 setauuser(void)
102 {
103 
104 #ifdef HAVE_PTHREAD_MUTEX_LOCK
105 	pthread_mutex_lock(&mutex);
106 #endif
107 	setauuser_locked();
108 #ifdef HAVE_PTHREAD_MUTEX_LOCK
109 	pthread_mutex_unlock(&mutex);
110 #endif
111 }
112 
113 /*
114  * Close the file descriptor
115  */
116 void
117 endauuser(void)
118 {
119 
120 #ifdef HAVE_PTHREAD_MUTEX_LOCK
121 	pthread_mutex_lock(&mutex);
122 #endif
123 	if (fp != NULL) {
124 		fclose(fp);
125 		fp = NULL;
126 	}
127 #ifdef HAVE_PTHREAD_MUTEX_LOCK
128 	pthread_mutex_unlock(&mutex);
129 #endif
130 }
131 
132 /*
133  * Enumerate the au_user_ent structures from the file
134  */
135 static struct au_user_ent *
136 getauuserent_r_locked(struct au_user_ent *u)
137 {
138 	char *nl;
139 
140 	if ((fp == NULL) && ((fp = fopen(AUDIT_USER_FILE, "r")) == NULL))
141 		return (NULL);
142 
143 	while (1) {
144 		if (fgets(linestr, AU_LINE_MAX, fp) == NULL)
145 			return (NULL);
146 
147 		/* Remove new lines. */
148 		if ((nl = strrchr(linestr, '\n')) != NULL)
149 			*nl = '\0';
150 
151 		/* Skip comments. */
152 		if (linestr[0] == '#')
153 			continue;
154 
155 		/* Get the next structure. */
156 		if (userfromstr(linestr, u) == NULL)
157 			return (NULL);
158 		break;
159 	}
160 
161 	return (u);
162 }
163 
164 struct au_user_ent *
165 getauuserent_r(struct au_user_ent *u)
166 {
167 	struct au_user_ent *up;
168 
169 #ifdef HAVE_PTHREAD_MUTEX_LOCK
170 	pthread_mutex_lock(&mutex);
171 #endif
172 	up = getauuserent_r_locked(u);
173 #ifdef HAVE_PTHREAD_MUTEX_LOCK
174 	pthread_mutex_unlock(&mutex);
175 #endif
176 	return (up);
177 }
178 
179 struct au_user_ent *
180 getauuserent(void)
181 {
182 	static char user_ent_name[AU_USER_NAME_MAX];
183 	static struct au_user_ent u;
184 
185 	bzero(&u, sizeof(u));
186 	bzero(user_ent_name, sizeof(user_ent_name));
187 	u.au_name = user_ent_name;
188 
189 	return (getauuserent_r(&u));
190 }
191 
192 /*
193  * Find a au_user_ent structure matching the given user name.
194  */
195 struct au_user_ent *
196 getauusernam_r(struct au_user_ent *u, const char *name)
197 {
198 	struct au_user_ent *up;
199 
200 	if (name == NULL)
201 		return (NULL);
202 
203 #ifdef HAVE_PTHREAD_MUTEX_LOCK
204 	pthread_mutex_lock(&mutex);
205 #endif
206 
207 	setauuser_locked();
208 	while ((up = getauuserent_r_locked(u)) != NULL) {
209 		if (strcmp(name, u->au_name) == 0) {
210 #ifdef HAVE_PTHREAD_MUTEX_LOCK
211 			pthread_mutex_unlock(&mutex);
212 #endif
213 			return (up);
214 		}
215 	}
216 
217 #ifdef HAVE_PTHREAD_MUTEX_LOCK
218 	pthread_mutex_unlock(&mutex);
219 #endif
220 	return (NULL);
221 
222 }
223 
224 struct au_user_ent *
225 getauusernam(const char *name)
226 {
227 	static char user_ent_name[AU_USER_NAME_MAX];
228 	static struct au_user_ent u;
229 
230 	bzero(&u, sizeof(u));
231 	bzero(user_ent_name, sizeof(user_ent_name));
232 	u.au_name = user_ent_name;
233 
234 	return (getauusernam_r(&u, name));
235 }
236 
237 /*
238  * Read the default system wide audit classes from audit_control, combine with
239  * the per-user audit class and update the binary preselection mask.
240  */
241 int
242 au_user_mask(char *username, au_mask_t *mask_p)
243 {
244 	char auditstring[MAX_AUDITSTRING_LEN + 1];
245 	char user_ent_name[AU_USER_NAME_MAX];
246 	struct au_user_ent u, *up;
247 
248 	bzero(&u, sizeof(u));
249 	bzero(user_ent_name, sizeof(user_ent_name));
250 	u.au_name = user_ent_name;
251 
252 	/* Get user mask. */
253 	if ((up = getauusernam_r(&u, username)) != NULL) {
254 		if (-1 == getfauditflags(&up->au_always, &up->au_never,
255 		    mask_p))
256 			return (-1);
257 		return (0);
258 	}
259 
260 	/* Read the default system mask. */
261 	if (getacflg(auditstring, MAX_AUDITSTRING_LEN) == 0) {
262 		if (-1 == getauditflagsbin(auditstring, mask_p))
263 			return (-1);
264 		return (0);
265 	}
266 
267 	/* No masks defined. */
268 	return (-1);
269 }
270 
271 /*
272  * Generate the process audit state by combining the audit masks passed as
273  * parameters with the system audit masks.
274  */
275 int
276 getfauditflags(au_mask_t *usremask, au_mask_t *usrdmask, au_mask_t *lastmask)
277 {
278 	char auditstring[MAX_AUDITSTRING_LEN + 1];
279 
280 	if ((usremask == NULL) || (usrdmask == NULL) || (lastmask == NULL))
281 		return (-1);
282 
283 	lastmask->am_success = 0;
284 	lastmask->am_failure = 0;
285 
286 	/* Get the system mask. */
287 	if (getacflg(auditstring, MAX_AUDITSTRING_LEN) == 0) {
288 		if (getauditflagsbin(auditstring, lastmask) != 0)
289 			return (-1);
290 	}
291 
292 	ADDMASK(lastmask, usremask);
293 	SUBMASK(lastmask, usrdmask);
294 
295 	return (0);
296 }
297