xref: /freebsd/contrib/openbsm/libbsm/bsm_wrappers.c (revision ca0716f5714781ac39461f60647d795321921363)
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#14 $
30  */
31 
32 #include <sys/param.h>
33 #include <sys/stat.h>
34 #include <sys/sysctl.h>
35 
36 #include <bsm/libbsm.h>
37 
38 #include <unistd.h>
39 #include <syslog.h>
40 #include <string.h>
41 #include <errno.h>
42 
43 /* These are not advertised in libbsm.h */
44 int audit_set_terminal_port(dev_t *p);
45 int audit_set_terminal_host(uint32_t *m);
46 
47 int
48 audit_set_terminal_port(dev_t *p)
49 {
50 	struct stat st;
51 
52 	if (p == NULL)
53 		return (kAUBadParamErr);
54 
55 	*p = NODEV;
56 
57 	/* for /usr/bin/login, try fstat() first */
58 	if (fstat(STDIN_FILENO, &st) != 0) {
59 		if (errno != EBADF) {
60 			syslog(LOG_ERR, "fstat() failed (%s)",
61 			    strerror(errno));
62 			return (kAUStatErr);
63 		}
64 		if (stat("/dev/console", &st) != 0) {
65 			syslog(LOG_ERR, "stat() failed (%s)",
66 			    strerror(errno));
67 			return (kAUStatErr);
68 		}
69 	}
70 	*p = st.st_rdev;
71 	return (kAUNoErr);
72 }
73 
74 int
75 audit_set_terminal_host(uint32_t *m)
76 {
77 	int name[2] = { CTL_KERN, KERN_HOSTID };
78 	size_t len;
79 
80 	if (m == NULL)
81 		return (kAUBadParamErr);
82 	*m = 0;
83 	len = sizeof(*m);
84 	if (sysctl(name, 2, m, &len, NULL, 0) != 0) {
85 		syslog(LOG_ERR, "sysctl() failed (%s)", strerror(errno));
86 		return (kAUSysctlErr);
87 	}
88 	return (kAUNoErr);
89 }
90 
91 int
92 audit_set_terminal_id(au_tid_t *tid)
93 {
94 	int ret;
95 
96 	if (tid == NULL)
97 		return (kAUBadParamErr);
98 	if ((ret = audit_set_terminal_port(&tid->port)) != kAUNoErr)
99 		return (ret);
100 	return (audit_set_terminal_host(&tid->machine));
101 }
102 
103 /*
104  * This is OK for those callers who have only one token to write.  If you have
105  * multiple tokens that logically form part of the same audit record, you need
106  * to use the existing au_open()/au_write()/au_close() API:
107  *
108  * aufd = au_open();
109  * tok = au_to_random_token_1(...);
110  * au_write(aufd, tok);
111  * tok = au_to_random_token_2(...);
112  * au_write(aufd, tok);
113  * ...
114  * au_close(aufd, 1, AUE_your_event_type);
115  *
116  * Assumes, like all wrapper calls, that the caller has previously checked
117  * that auditing is enabled via the audit_get_state() call.
118  *
119  * XXX: Should be more robust against bad arguments.
120  */
121 int
122 audit_write(short event_code, token_t *subject, token_t *misctok, char retval,
123     int errcode)
124 {
125 	int aufd;
126 	char *func = "audit_write()";
127 	token_t *rettok;
128 
129 	if ((aufd = au_open()) == -1) {
130 		au_free_token(subject);
131 		au_free_token(misctok);
132 		syslog(LOG_ERR, "%s: au_open() failed", func);
133 		return (kAUOpenErr);
134 	}
135 
136 	/* Save subject. */
137 	if (subject && au_write(aufd, subject) == -1) {
138 		au_free_token(subject);
139 		au_free_token(misctok);
140 		(void)au_close(aufd, 0, event_code);
141 		syslog(LOG_ERR, "%s: write of subject failed", func);
142 		return (kAUWriteSubjectTokErr);
143 	}
144 
145 	/* Save the event-specific token. */
146 	if (misctok && au_write(aufd, misctok) == -1) {
147 		au_free_token(misctok);
148 		(void)au_close(aufd, 0, event_code);
149 		syslog(LOG_ERR, "%s: write of caller token failed", func);
150 		return (kAUWriteCallerTokErr);
151 	}
152 
153 	/* Tokenize and save the return value. */
154 	if ((rettok = au_to_return32(retval, errcode)) == NULL) {
155 		(void)au_close(aufd, 0, event_code);
156 		syslog(LOG_ERR, "%s: au_to_return32() failed", func);
157 		return (kAUMakeReturnTokErr);
158 	}
159 
160 	if (au_write(aufd, rettok) == -1) {
161 		au_free_token(rettok);
162 		(void)au_close(aufd, 0, event_code);
163 		syslog(LOG_ERR, "%s: write of return code failed", func);
164 		return (kAUWriteReturnTokErr);
165 	}
166 
167 	/*
168 	 * au_close()'s second argument is "keep": if keep == 0, the record is
169 	 * discarded.  We assume the caller wouldn't have bothered with this
170 	 * function if it hadn't already decided to keep the record.
171 	 */
172 	if (au_close(aufd, 1, event_code) < 0) {
173 		syslog(LOG_ERR, "%s: au_close() failed", func);
174 		return (kAUCloseErr);
175 	}
176 
177 	return (kAUNoErr);
178 }
179 
180 /*
181  * Same caveats as audit_write().  In addition, this function explicitly
182  * assumes success; use audit_write_failure() on error.
183  */
184 int
185 audit_write_success(short event_code, token_t *tok, au_id_t auid, uid_t euid,
186     gid_t egid, uid_t ruid, gid_t rgid, pid_t pid, au_asid_t sid,
187     au_tid_t *tid)
188 {
189 	char *func = "audit_write_success()";
190 	token_t *subject = NULL;
191 
192 	/* Tokenize and save subject. */
193 	subject = au_to_subject32(auid, euid, egid, ruid, rgid, pid, sid,
194 	    tid);
195 	if (subject == NULL) {
196 		syslog(LOG_ERR, "%s: au_to_subject32() failed", func);
197 		return kAUMakeSubjectTokErr;
198 	}
199 
200 	return (audit_write(event_code, subject, tok, 0, 0));
201 }
202 
203 /*
204  * Same caveats as audit_write().  In addition, this function explicitly
205  * assumes success; use audit_write_failure_self() on error.
206  */
207 int
208 audit_write_success_self(short event_code, token_t *tok)
209 {
210 	token_t *subject;
211 	char *func = "audit_write_success_self()";
212 
213 	if ((subject = au_to_me()) == NULL) {
214 		syslog(LOG_ERR, "%s: au_to_me() failed", func);
215 		return (kAUMakeSubjectTokErr);
216 	}
217 
218 	return (audit_write(event_code, subject, tok, 0, 0));
219 }
220 
221 /*
222  * Same caveats as audit_write().  In addition, this function explicitly
223  * assumes failure; use audit_write_success() otherwise.
224  *
225  * XXX  This should let the caller pass an error return value rather than
226  * hard-coding -1.
227  */
228 int
229 audit_write_failure(short event_code, char *errmsg, int errcode, au_id_t auid,
230     uid_t euid, gid_t egid, uid_t ruid, gid_t rgid, pid_t pid, au_asid_t sid,
231     au_tid_t *tid)
232 {
233 	char *func = "audit_write_failure()";
234 	token_t *subject, *errtok;
235 
236 	subject = au_to_subject32(auid, euid, egid, ruid, rgid, pid, sid, tid);
237 	if (subject == NULL) {
238 		syslog(LOG_ERR, "%s: au_to_subject32() failed", func);
239 		return (kAUMakeSubjectTokErr);
240 	}
241 
242 	/* tokenize and save the error message */
243 	if ((errtok = au_to_text(errmsg)) == NULL) {
244 		au_free_token(subject);
245 		syslog(LOG_ERR, "%s: au_to_text() failed", func);
246 		return (kAUMakeTextTokErr);
247 	}
248 
249 	return (audit_write(event_code, subject, errtok, -1, errcode));
250 }
251 
252 /*
253  * Same caveats as audit_write().  In addition, this function explicitly
254  * assumes failure; use audit_write_success_self() otherwise.
255  *
256  * XXX  This should let the caller pass an error return value rather than
257  * hard-coding -1.
258  */
259 int
260 audit_write_failure_self(short event_code, char *errmsg, int errret)
261 {
262 	char *func = "audit_write_failure_self()";
263 	token_t *subject, *errtok;
264 
265 	if ((subject = au_to_me()) == NULL) {
266 		syslog(LOG_ERR, "%s: au_to_me() failed", func);
267 		return (kAUMakeSubjectTokErr);
268 	}
269 	/* tokenize and save the error message */
270 	if ((errtok = au_to_text(errmsg)) == NULL) {
271 		au_free_token(subject);
272 		syslog(LOG_ERR, "%s: au_to_text() failed", func);
273 		return (kAUMakeTextTokErr);
274 	}
275 	return (audit_write(event_code, subject, errtok, -1, errret));
276 }
277 
278 /*
279  * For auditing errors during login.  Such errors are implicitly
280  * non-attributable (i.e., not ascribable to any user).
281  *
282  * Assumes, like all wrapper calls, that the caller has previously checked
283  * that auditing is enabled via the audit_get_state() call.
284  */
285 int
286 audit_write_failure_na(short event_code, char *errmsg, int errret, uid_t euid,
287     uid_t egid, pid_t pid, au_tid_t *tid)
288 {
289 
290 	return (audit_write_failure(event_code, errmsg, errret, -1, euid,
291 	    egid, -1, -1, pid, -1, tid));
292 }
293 
294 /* END OF au_write() WRAPPERS */
295 
296 #ifdef __APPLE__
297 void
298 audit_token_to_au32(audit_token_t atoken, uid_t *auidp, uid_t *euidp,
299     gid_t *egidp, uid_t *ruidp, gid_t *rgidp, pid_t *pidp, au_asid_t *asidp,
300     au_tid_t *tidp)
301 {
302 
303 	if (auidp != NULL)
304 		*auidp = (uid_t)atoken.val[0];
305 	if (euidp != NULL)
306 		*euidp = (uid_t)atoken.val[1];
307 	if (egidp != NULL)
308 		*egidp = (gid_t)atoken.val[2];
309 	if (ruidp != NULL)
310 		*ruidp = (uid_t)atoken.val[3];
311 	if (rgidp != NULL)
312 		*rgidp = (gid_t)atoken.val[4];
313 	if (pidp != NULL)
314 		*pidp = (pid_t)atoken.val[5];
315 	if (asidp != NULL)
316 		*asidp = (au_asid_t)atoken.val[6];
317 	if (tidp != NULL) {
318 		audit_set_terminal_host(&tidp->machine);
319 		tidp->port = (dev_t)atoken.val[7];
320 	}
321 }
322 #endif /* !__APPLE__ */
323