xref: /freebsd/contrib/openbsm/libbsm/bsm_wrappers.c (revision 87569f75a91f298c52a71823c04d41cf53c88889)
1 /*
2  * Copyright (c) 2004 Apple Computer, Inc.
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  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14  *     its contributors may be used to endorse or promote products derived
15  *     from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $P4: //depot/projects/trustedbsd/openbsm/libbsm/bsm_wrappers.c#18 $
30  */
31 
32 #ifdef __APPLE__
33 #define	_SYS_AUDIT_H		/* Prevent include of sys/audit.h. */
34 #endif
35 
36 #include <sys/param.h>
37 #include <sys/stat.h>
38 
39 #ifdef __APPLE__
40 #include <sys/queue.h>		/* Our bsm/audit.h doesn't include queue.h. */
41 #endif
42 
43 #include <sys/sysctl.h>
44 
45 #include <bsm/libbsm.h>
46 
47 #include <unistd.h>
48 #include <syslog.h>
49 #include <string.h>
50 #include <errno.h>
51 
52 /* These are not advertised in libbsm.h */
53 int audit_set_terminal_port(dev_t *p);
54 int audit_set_terminal_host(uint32_t *m);
55 
56 int
57 audit_set_terminal_port(dev_t *p)
58 {
59 	struct stat st;
60 
61 	if (p == NULL)
62 		return (kAUBadParamErr);
63 
64 #ifdef NODEV
65 	*p = NODEV;
66 #else
67 	*p = -1;
68 #endif
69 
70 	/* for /usr/bin/login, try fstat() first */
71 	if (fstat(STDIN_FILENO, &st) != 0) {
72 		if (errno != EBADF) {
73 			syslog(LOG_ERR, "fstat() failed (%s)",
74 			    strerror(errno));
75 			return (kAUStatErr);
76 		}
77 		if (stat("/dev/console", &st) != 0) {
78 			syslog(LOG_ERR, "stat() failed (%s)",
79 			    strerror(errno));
80 			return (kAUStatErr);
81 		}
82 	}
83 	*p = st.st_rdev;
84 	return (kAUNoErr);
85 }
86 
87 int
88 audit_set_terminal_host(uint32_t *m)
89 {
90 
91 #ifdef KERN_HOSTID
92 	int name[2] = { CTL_KERN, KERN_HOSTID };
93 	size_t len;
94 
95 	if (m == NULL)
96 		return (kAUBadParamErr);
97 	*m = 0;
98 	len = sizeof(*m);
99 	if (sysctl(name, 2, m, &len, NULL, 0) != 0) {
100 		syslog(LOG_ERR, "sysctl() failed (%s)", strerror(errno));
101 		return (kAUSysctlErr);
102 	}
103 	return (kAUNoErr);
104 #else
105 	*m = -1;
106 	return (kAUNoErr);
107 #endif
108 }
109 
110 int
111 audit_set_terminal_id(au_tid_t *tid)
112 {
113 	int ret;
114 
115 	if (tid == NULL)
116 		return (kAUBadParamErr);
117 	if ((ret = audit_set_terminal_port(&tid->port)) != kAUNoErr)
118 		return (ret);
119 	return (audit_set_terminal_host(&tid->machine));
120 }
121 
122 /*
123  * This is OK for those callers who have only one token to write.  If you have
124  * multiple tokens that logically form part of the same audit record, you need
125  * to use the existing au_open()/au_write()/au_close() API:
126  *
127  * aufd = au_open();
128  * tok = au_to_random_token_1(...);
129  * au_write(aufd, tok);
130  * tok = au_to_random_token_2(...);
131  * au_write(aufd, tok);
132  * ...
133  * au_close(aufd, 1, AUE_your_event_type);
134  *
135  * Assumes, like all wrapper calls, that the caller has previously checked
136  * that auditing is enabled via the audit_get_state() call.
137  *
138  * XXX: Should be more robust against bad arguments.
139  */
140 int
141 audit_write(short event_code, token_t *subject, token_t *misctok, char retval,
142     int errcode)
143 {
144 	int aufd;
145 	char *func = "audit_write()";
146 	token_t *rettok;
147 
148 	if ((aufd = au_open()) == -1) {
149 		au_free_token(subject);
150 		au_free_token(misctok);
151 		syslog(LOG_ERR, "%s: au_open() failed", func);
152 		return (kAUOpenErr);
153 	}
154 
155 	/* Save subject. */
156 	if (subject && au_write(aufd, subject) == -1) {
157 		au_free_token(subject);
158 		au_free_token(misctok);
159 		(void)au_close(aufd, 0, event_code);
160 		syslog(LOG_ERR, "%s: write of subject failed", func);
161 		return (kAUWriteSubjectTokErr);
162 	}
163 
164 	/* Save the event-specific token. */
165 	if (misctok && au_write(aufd, misctok) == -1) {
166 		au_free_token(misctok);
167 		(void)au_close(aufd, 0, event_code);
168 		syslog(LOG_ERR, "%s: write of caller token failed", func);
169 		return (kAUWriteCallerTokErr);
170 	}
171 
172 	/* Tokenize and save the return value. */
173 	if ((rettok = au_to_return32(retval, errcode)) == NULL) {
174 		(void)au_close(aufd, 0, event_code);
175 		syslog(LOG_ERR, "%s: au_to_return32() failed", func);
176 		return (kAUMakeReturnTokErr);
177 	}
178 
179 	if (au_write(aufd, rettok) == -1) {
180 		au_free_token(rettok);
181 		(void)au_close(aufd, 0, event_code);
182 		syslog(LOG_ERR, "%s: write of return code failed", func);
183 		return (kAUWriteReturnTokErr);
184 	}
185 
186 	/*
187 	 * au_close()'s second argument is "keep": if keep == 0, the record is
188 	 * discarded.  We assume the caller wouldn't have bothered with this
189 	 * function if it hadn't already decided to keep the record.
190 	 */
191 	if (au_close(aufd, 1, event_code) < 0) {
192 		syslog(LOG_ERR, "%s: au_close() failed", func);
193 		return (kAUCloseErr);
194 	}
195 
196 	return (kAUNoErr);
197 }
198 
199 /*
200  * Same caveats as audit_write().  In addition, this function explicitly
201  * assumes success; use audit_write_failure() on error.
202  */
203 int
204 audit_write_success(short event_code, token_t *tok, au_id_t auid, uid_t euid,
205     gid_t egid, uid_t ruid, gid_t rgid, pid_t pid, au_asid_t sid,
206     au_tid_t *tid)
207 {
208 	char *func = "audit_write_success()";
209 	token_t *subject = NULL;
210 
211 	/* Tokenize and save subject. */
212 	subject = au_to_subject32(auid, euid, egid, ruid, rgid, pid, sid,
213 	    tid);
214 	if (subject == NULL) {
215 		syslog(LOG_ERR, "%s: au_to_subject32() failed", func);
216 		return kAUMakeSubjectTokErr;
217 	}
218 
219 	return (audit_write(event_code, subject, tok, 0, 0));
220 }
221 
222 /*
223  * Same caveats as audit_write().  In addition, this function explicitly
224  * assumes success; use audit_write_failure_self() on error.
225  */
226 int
227 audit_write_success_self(short event_code, token_t *tok)
228 {
229 	token_t *subject;
230 	char *func = "audit_write_success_self()";
231 
232 	if ((subject = au_to_me()) == NULL) {
233 		syslog(LOG_ERR, "%s: au_to_me() failed", func);
234 		return (kAUMakeSubjectTokErr);
235 	}
236 
237 	return (audit_write(event_code, subject, tok, 0, 0));
238 }
239 
240 /*
241  * Same caveats as audit_write().  In addition, this function explicitly
242  * assumes failure; use audit_write_success() otherwise.
243  *
244  * XXX  This should let the caller pass an error return value rather than
245  * hard-coding -1.
246  */
247 int
248 audit_write_failure(short event_code, char *errmsg, int errcode, au_id_t auid,
249     uid_t euid, gid_t egid, uid_t ruid, gid_t rgid, pid_t pid, au_asid_t sid,
250     au_tid_t *tid)
251 {
252 	char *func = "audit_write_failure()";
253 	token_t *subject, *errtok;
254 
255 	subject = au_to_subject32(auid, euid, egid, ruid, rgid, pid, sid, tid);
256 	if (subject == NULL) {
257 		syslog(LOG_ERR, "%s: au_to_subject32() failed", func);
258 		return (kAUMakeSubjectTokErr);
259 	}
260 
261 	/* tokenize and save the error message */
262 	if ((errtok = au_to_text(errmsg)) == NULL) {
263 		au_free_token(subject);
264 		syslog(LOG_ERR, "%s: au_to_text() failed", func);
265 		return (kAUMakeTextTokErr);
266 	}
267 
268 	return (audit_write(event_code, subject, errtok, -1, errcode));
269 }
270 
271 /*
272  * Same caveats as audit_write().  In addition, this function explicitly
273  * assumes failure; use audit_write_success_self() otherwise.
274  *
275  * XXX  This should let the caller pass an error return value rather than
276  * hard-coding -1.
277  */
278 int
279 audit_write_failure_self(short event_code, char *errmsg, int errret)
280 {
281 	char *func = "audit_write_failure_self()";
282 	token_t *subject, *errtok;
283 
284 	if ((subject = au_to_me()) == NULL) {
285 		syslog(LOG_ERR, "%s: au_to_me() failed", func);
286 		return (kAUMakeSubjectTokErr);
287 	}
288 	/* tokenize and save the error message */
289 	if ((errtok = au_to_text(errmsg)) == NULL) {
290 		au_free_token(subject);
291 		syslog(LOG_ERR, "%s: au_to_text() failed", func);
292 		return (kAUMakeTextTokErr);
293 	}
294 	return (audit_write(event_code, subject, errtok, -1, errret));
295 }
296 
297 /*
298  * For auditing errors during login.  Such errors are implicitly
299  * non-attributable (i.e., not ascribable to any user).
300  *
301  * Assumes, like all wrapper calls, that the caller has previously checked
302  * that auditing is enabled via the audit_get_state() call.
303  */
304 int
305 audit_write_failure_na(short event_code, char *errmsg, int errret, uid_t euid,
306     uid_t egid, pid_t pid, au_tid_t *tid)
307 {
308 
309 	return (audit_write_failure(event_code, errmsg, errret, -1, euid,
310 	    egid, -1, -1, pid, -1, tid));
311 }
312 
313 /* END OF au_write() WRAPPERS */
314 
315 #ifdef __APPLE__
316 void
317 audit_token_to_au32(audit_token_t atoken, uid_t *auidp, uid_t *euidp,
318     gid_t *egidp, uid_t *ruidp, gid_t *rgidp, pid_t *pidp, au_asid_t *asidp,
319     au_tid_t *tidp)
320 {
321 
322 	if (auidp != NULL)
323 		*auidp = (uid_t)atoken.val[0];
324 	if (euidp != NULL)
325 		*euidp = (uid_t)atoken.val[1];
326 	if (egidp != NULL)
327 		*egidp = (gid_t)atoken.val[2];
328 	if (ruidp != NULL)
329 		*ruidp = (uid_t)atoken.val[3];
330 	if (rgidp != NULL)
331 		*rgidp = (gid_t)atoken.val[4];
332 	if (pidp != NULL)
333 		*pidp = (pid_t)atoken.val[5];
334 	if (asidp != NULL)
335 		*asidp = (au_asid_t)atoken.val[6];
336 	if (tidp != NULL) {
337 		audit_set_terminal_host(&tidp->machine);
338 		tidp->port = (dev_t)atoken.val[7];
339 	}
340 }
341 #endif /* !__APPLE__ */
342