xref: /illumos-gate/usr/src/lib/libbsm/common/audit_rexd.c (revision 826ac02a0def83e0a41b29321470d299c7389aab)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 #include <sys/types.h>
26 #include <sys/param.h>
27 #include <stdio.h>
28 #include <unistd.h>
29 #include <sys/fcntl.h>
30 #include <bsm/audit.h>
31 #include <bsm/audit_record.h>
32 #include <bsm/audit_uevents.h>
33 #include <bsm/libbsm.h>
34 #include <bsm/audit_private.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <syslog.h>
38 #include <pwd.h>
39 #include <netinet/in.h>
40 #include <tsol/label.h>
41 #include <locale.h>
42 #include "generic.h"
43 
44 #ifdef C2_DEBUG
45 #define	dprintf(x) { (void) printf x; }
46 #else
47 #define	dprintf(x)
48 #endif
49 
50 #define	UNKNOWN_CMD	"???"
51 
52 static au_event_t	event;
53 static int		audit_rexd_status = 0;
54 
55 static char *
56 build_cmd(char **cmd)
57 {
58 	int i, l;
59 	char *r;
60 
61 	if (cmd == NULL)
62 		return (NULL);
63 	/* count the total length of command line */
64 	for (i = 0, l = 0; cmd[i] != NULL; i++)
65 		l += strlen(cmd[i]) + 1;
66 
67 	if (l == 0)
68 		return (NULL);
69 	r = malloc(l);
70 	if (r != NULL) {
71 		for (i = 0; cmd[i] != NULL; i++) {
72 			(void) strcat(r, cmd[i]);
73 			if (cmd[i + 1] != NULL)
74 				(void) strcat(r, " ");
75 		}
76 	}
77 	return (r);
78 }
79 
80 static int
81 selected(uid, user, event, sf)
82 uid_t uid;
83 char	*user;
84 au_event_t	event;
85 int	sf;
86 {
87 	int		sorf;
88 	struct au_mask	mask;
89 
90 	mask.am_success = mask.am_failure = 0;
91 	if (uid > MAXEPHUID) {
92 		/* get non-attrib flags */
93 		(void) auditon(A_GETKMASK, (caddr_t)&mask, sizeof (mask));
94 	} else {
95 		(void) au_user_mask(user, &mask);
96 	}
97 
98 	if (sf == 0) {
99 		sorf = AU_PRS_SUCCESS;
100 	} else if (sf == -1) {
101 		sorf = AU_PRS_FAILURE;
102 	} else {
103 		sorf = AU_PRS_BOTH;
104 	}
105 
106 	return (au_preselect(event, &mask, sorf, AU_PRS_REREAD));
107 }
108 
109 void
110 audit_rexd_setup()
111 {
112 	dprintf(("audit_rexd_setup()\n"));
113 
114 	event = AUE_rexd;
115 }
116 
117 /* ARGSUSED */
118 static void
119 audit_rexd_session_setup(char *name, char *mach, uid_t uid)
120 {
121 	int			rc;
122 	au_mask_t		mask;
123 	struct auditinfo_addr	info;
124 
125 	if (getaudit_addr(&info, sizeof (info)) < 0) {
126 		perror("getaudit_addr");
127 		exit(1);
128 	}
129 
130 	info.ai_auid = uid;
131 	info.ai_asid = getpid();
132 
133 	mask.am_success = 0;
134 	mask.am_failure = 0;
135 
136 	(void) au_user_mask(name, &mask);
137 
138 	info.ai_mask.am_success  = mask.am_success;
139 	info.ai_mask.am_failure  = mask.am_failure;
140 
141 	rc = setaudit_addr(&info, sizeof (info));
142 	if (rc < 0) {
143 		perror("setaudit_addr");
144 	}
145 }
146 
147 void
148 audit_rexd_fail(msg, hostname, user, uid, gid, shell, cmd)
149 	char	*msg;		/* message containing failure information */
150 	char	*hostname;	/* hostname of machine requesting service */
151 	char	*user;		/* username of user requesting service */
152 	uid_t 	uid;		/* user id of user requesting service */
153 	gid_t	gid;		/* group of user requesting service */
154 	char	*shell;		/* login shell of user requesting service */
155 	char	**cmd;		/* argv to be executed locally */
156 {
157 	int	rd;		/* audit record descriptor */
158 	char	buf[256];	/* temporary buffer */
159 	char	*tbuf;		/* temporary buffer */
160 	int	tlen;
161 	const char *gtxt;	/* gettext return value */
162 	pid_t	pid;
163 	char	*cmdbuf;
164 	char	*audit_cmd[2] = {NULL, NULL};
165 	int	dont_free = 0;
166 	struct auditinfo_addr info;
167 
168 	dprintf(("audit_rexd_fail()\n"));
169 
170 	/*
171 	 * check if audit_rexd_fail() or audit_rexd_success()
172 	 * have been called already.
173 	 */
174 	if (audit_rexd_status == 1) {
175 		return;
176 	}
177 
178 	if (cannot_audit(0)) {
179 		return;
180 	}
181 
182 	/*
183 	 * set status to prevent multiple calls
184 	 * to audit_rexd_fail() and audit_rexd_success()
185 	 */
186 	audit_rexd_status = 1;
187 
188 	/* determine if we're preselected */
189 	if (!selected(uid, user, event, -1))
190 		return;
191 
192 	pid = getpid();
193 
194 	if (getaudit_addr(&info, sizeof (info)) < 0) {
195 		perror("getaudit_addr");
196 		exit(1);
197 	}
198 
199 	rd = au_open();
200 
201 	/* add subject token */
202 	(void) au_write(rd,
203 		au_to_subject_ex(uid, uid, gid, uid, gid, pid, pid,
204 			&info.ai_termid));
205 	if (is_system_labeled())
206 		(void) au_write(rd, au_to_mylabel());
207 
208 	/* add reason for failure */
209 	(void) au_write(rd, au_to_text(msg));
210 
211 	/* add hostname of machine requesting service */
212 	(void) snprintf(buf, sizeof (buf), dgettext(bsm_dom,
213 		"Remote execution requested by: %s"), hostname);
214 	(void) au_write(rd, au_to_text(buf));
215 
216 	/* add username of user requesting service */
217 	if (user == NULL)
218 		user = "???";
219 	(void) snprintf(buf, sizeof (buf), dgettext(bsm_dom,
220 	    "Username: %s"), user);
221 	(void) au_write(rd, au_to_text(buf));
222 
223 	(void) snprintf(buf, sizeof (buf), dgettext(bsm_dom,
224 	    "User id: %d"), uid);
225 	(void) au_write(rd, au_to_text(buf));
226 
227 	if (cmd == NULL) {
228 		audit_cmd[0] = shell;
229 		cmd = audit_cmd;
230 	}
231 
232 	cmdbuf = build_cmd(cmd);
233 	if (cmdbuf == NULL) {
234 		cmdbuf = UNKNOWN_CMD;
235 		dont_free = 1;
236 	}
237 
238 	gtxt = dgettext(bsm_dom, "Command line: %s");
239 	/* over estimate of size of buffer needed (%s is replaced) */
240 	tlen = strlen(cmdbuf) + strlen(gtxt) + 1;
241 
242 	if ((tbuf = malloc(tlen)) == NULL) {
243 		(void) au_close(rd, 0, 0);
244 		return;
245 	}
246 	(void) snprintf(tbuf, tlen, gtxt, cmdbuf);
247 	(void) au_write(rd, au_to_text(tbuf));
248 	(void) free(tbuf);
249 	if (!dont_free)
250 		(void) free(cmdbuf);
251 
252 	/* add return token */
253 #ifdef _LP64
254 	(void) au_write(rd, au_to_return64(-1, (int64_t)0));
255 #else
256 	(void) au_write(rd, au_to_return32(-1, (int32_t)0));
257 #endif
258 
259 	/* write audit record */
260 	if (au_close(rd, 1, event) < 0) {
261 		(void) au_close(rd, 0, 0);
262 		return;
263 	}
264 }
265 
266 void
267 audit_rexd_success(hostname, user, uid, gid, shell, cmd)
268 char	*hostname;	/* hostname of machine requesting service */
269 char	*user;		/* username of user requesting service, may be NULL */
270 uid_t 	uid;		/* user id of user requesting service */
271 gid_t	gid;		/* group of user requesting service */
272 char	*shell;		/* login shell of user requesting service */
273 char	**cmd;		/* argv to be executed locally, may be NULL */
274 {
275 	int	rd;			/* audit record descriptor */
276 	char	buf[256];	/* temporary buffer */
277 	char	*tbuf;		/* temporary buffer */
278 	int	tlen;
279 	const char *gtxt;
280 	pid_t	pid;
281 	char	*cmdbuf;
282 	char	*audit_cmd[2] = {NULL, NULL};
283 	int	dont_free = 0;
284 	struct auditinfo_addr info;
285 	char	*empty = "";
286 
287 	dprintf(("audit_rexd_success()\n"));
288 
289 	/*
290 	 * check if audit_rexd_fail() or audit_rexd_success()
291 	 * have been called already.
292 	 */
293 	if (audit_rexd_status == 1) {
294 		return;
295 	}
296 
297 	if (cannot_audit(0)) {
298 		return;
299 	}
300 
301 	/* a little bullet proofing... */
302 
303 	if (hostname == NULL)
304 		hostname = empty;
305 	if (shell == NULL)
306 		shell = empty;
307 
308 	/*
309 	 * set status to prevent multiple calls
310 	 * to audit_rexd_fail() and audit_rexd_success()
311 	 */
312 	audit_rexd_status = 1;
313 
314 	/* determine if we're preselected */
315 	if (!selected(uid, user, event, 0))
316 		goto rexd_audit_session;
317 
318 	pid = getpid();
319 
320 	if (getaudit_addr(&info, sizeof (info)) < 0) {
321 		perror("getaudit_addr");
322 		exit(1);
323 	}
324 
325 	rd = au_open();
326 
327 	/* add subject token */
328 	(void) au_write(rd,
329 		au_to_subject_ex(uid, uid, gid, uid, gid, pid, pid,
330 			&info.ai_termid));
331 	if (is_system_labeled())
332 		(void) au_write(rd, au_to_mylabel());
333 
334 	/* add hostname of machine requesting service */
335 
336 	(void) snprintf(buf, sizeof (buf), dgettext(bsm_dom,
337 		"Remote execution requested by: %s"), hostname);
338 	(void) au_write(rd, au_to_text(buf));
339 
340 	/* add username at machine requesting service */
341 	(void) snprintf(buf, sizeof (buf), dgettext(bsm_dom,
342 	    "Username: %s"), user);
343 	(void) au_write(rd, au_to_text(buf));
344 
345 	if (cmd == NULL) {
346 		audit_cmd[0] = shell;
347 		cmd = audit_cmd;
348 	}
349 
350 	cmdbuf = build_cmd(cmd);
351 	if (cmdbuf == NULL) {
352 		cmdbuf = UNKNOWN_CMD;
353 		dont_free = 1;
354 	}
355 
356 	gtxt = dgettext(bsm_dom, "Command line: %s");
357 	tlen = strlen(cmdbuf) + strlen(gtxt) + 1;
358 
359 	if ((tbuf = malloc(tlen)) == NULL) {
360 		(void) au_close(rd, 0, 0);
361 		goto rexd_audit_session;
362 	}
363 
364 	(void) snprintf(tbuf, tlen, gtxt, cmdbuf);
365 	(void) au_write(rd, au_to_text(tbuf));
366 	(void) free(tbuf);
367 	if (!dont_free)
368 		(void) free(cmdbuf);
369 
370 	/* add return token */
371 #ifdef _LP64
372 	(void) au_write(rd, au_to_return64(0, (int64_t)0));
373 #else
374 	(void) au_write(rd, au_to_return32(0, (int32_t)0));
375 #endif
376 
377 	/* write audit record */
378 	if (au_close(rd, 1, event) < 0) {
379 		(void) au_close(rd, 0, 0);
380 	}
381 
382 rexd_audit_session:
383 	audit_rexd_session_setup(user, hostname, uid);
384 }
385