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, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 * Copyright (c) 2016 by Delphix. All rights reserved.
26 */
27#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29#include <sys/types.h>
30#include <sys/stat.h>
31#include <sys/systeminfo.h>
32#include <bsm/audit.h>
33#include <bsm/libbsm.h>
34#include <bsm/audit_uevents.h>
35#include <bsm/audit_private.h>
36#include <unistd.h>
37#include <stdlib.h>
38#include <string.h>
39#include <pwd.h>
40
41#include <locale.h>
42#include "generic.h"
43
44#define	AUDIT_GET_DIFFS_NO_CRONTAB	1
45#define	AUDIT_GET_DIFFS_CRONTAB		0
46#define	AUDIT_GET_DIFFS_ERR		-1
47#define	AUDIT_GET_DIFFS_NO_DIFFS	-2
48
49static int	audit_crontab_get_diffs(char *cf, char *tmp_name,
50		    char **bufptr);
51
52int
53audit_crontab_modify(char *path, char *tmp_path, int sorf)
54{
55	int r, create = 0;
56	char *diffs = NULL;
57
58	if (cannot_audit(0)) {
59		return (0);
60	} else {
61		au_event_t event;
62		char *anc_name;
63		auditinfo_addr_t ai;
64
65		if (getaudit_addr(&ai, sizeof (ai))) {
66			return (-1);
67		}
68
69		r = audit_crontab_get_diffs(path, tmp_path, &diffs);
70
71		if (r == AUDIT_GET_DIFFS_NO_DIFFS) {
72			return (0);
73		}
74		if (diffs != NULL && r != AUDIT_GET_DIFFS_ERR) {
75			aug_save_text(diffs);
76			free(diffs);
77		}
78
79		if (r == AUDIT_GET_DIFFS_NO_CRONTAB) {
80			create = 1;
81			if (diffs == NULL)
82				aug_save_text("");
83		}
84
85		/*
86		 * create an ancilary file if audit characteristics exist
87		 * else delete an ancilary if if one exists
88		 */
89
90		anc_name = audit_cron_make_anc_name(path);
91		if (anc_name == NULL)
92			r = -1;
93		else if (audit_crontab_process_not_audited()) {
94			(void) unlink(anc_name);
95			free(anc_name);
96		} else {
97			r = audit_cron_setinfo(anc_name, &ai);
98			free(anc_name);
99		}
100		aug_init();
101		aug_save_auid(ai.ai_auid);
102		aug_save_euid(geteuid());
103		aug_save_egid(getegid());
104		aug_save_uid(getuid());
105		aug_save_gid(getgid());
106		aug_save_pid(getpid());
107		aug_save_asid(ai.ai_asid);
108		aug_save_tid_ex(ai.ai_termid.at_port, ai.ai_termid.at_addr,
109			ai.ai_termid.at_type);
110
111
112		aug_save_path(path);
113		event = (create) ? AUE_crontab_create : AUE_crontab_mod;
114		aug_save_event(event);
115		aug_save_sorf(sorf);
116
117		if (aug_audit() != 0)
118			return (-1);
119		return (r);
120	}
121}
122
123int
124audit_crontab_delete(char *path, int sorf)
125{
126	int r = 0;
127
128	if (cannot_audit(0)) {
129		return (0);
130	} else {
131		char *anc_name;
132		anc_name = audit_cron_make_anc_name(path);
133		if (anc_name != NULL) {
134			r = unlink(anc_name);
135			free(anc_name);
136		} else
137			r = -1;
138
139		aug_init();
140		(void) aug_save_me();
141
142		aug_save_path(path);
143		aug_save_event(AUE_crontab_delete);
144		aug_save_sorf(sorf);
145		if (aug_audit() != 0)
146			return (-1);
147		return (r);
148	}
149}
150
151/*
152 * gets differences between old and new crontab files.
153 * arguments:
154 * cf        - name of crontab file
155 * tmp_name  - name of new crontab file
156 * bufptr    - pointer to an array of characters with
157 *             either an error message or an output of "diff" command.
158 *
159 * results:
160 * AUDIT_GET_DIFFS_ERR       - errors;
161 *			file not exists (do not free *bufptr in this case)
162 * AUDIT_GET_DIFFS_NO_DIFFS  - errors;
163 *			file exists (do not free *bufptr in this case)
164 * AUDIT_GET_DIFFS_CRONTAB      - OK, old crontab file exists.
165 * AUDIT_GET_DIFFS_NO_CRONTAB   - OK. there is no crontab file.
166 */
167static int
168audit_crontab_get_diffs(char *cf, char *tmp_name, char **bufptr)
169{
170	struct stat st, st_tmp;
171	uid_t	euid;
172	int	len, r = AUDIT_GET_DIFFS_CRONTAB;
173	char	*buf = NULL, err_buf[128];
174
175	(void) memset(err_buf, 0, 128);
176	euid = geteuid();
177	if (seteuid(0) == -1) {
178		r = AUDIT_GET_DIFFS_ERR;
179		(void) snprintf(err_buf, sizeof (err_buf),
180		    "crontab: seteuid: %s\n", strerror(errno));
181		goto exit_diff;
182	}
183	if (stat(cf, &st) == -1) {
184		if (errno == ENOENT) {
185			r = AUDIT_GET_DIFFS_NO_CRONTAB;
186		} else {
187			r = AUDIT_GET_DIFFS_ERR;
188			(void) snprintf(err_buf, sizeof (err_buf),
189				"crontab: %s: stat: %s\n",
190				cf, strerror(errno));
191			goto exit_diff;
192		}
193		len = 0;
194	} else
195		len = st.st_size;
196
197	if (stat(tmp_name, &st_tmp) == -1) {
198		r = AUDIT_GET_DIFFS_ERR;
199		(void) snprintf(err_buf, sizeof (err_buf),
200			"crontab: %s: stat: %s\n",
201			tmp_name, strerror(errno));
202		goto exit_diff;
203	}
204
205	if (st_tmp.st_size == 0 && len == 0) {
206	/* there is no difference */
207		r = AUDIT_GET_DIFFS_NO_DIFFS;
208		*bufptr = NULL;
209		goto exit_diff;
210	}
211
212exit_diff:
213	/* return information on create or update crontab */
214	(void) seteuid(euid);
215	switch (r) {
216	case AUDIT_GET_DIFFS_ERR:
217		if (buf != NULL)
218			free(buf);
219		*bufptr = err_buf;
220		break;
221	case AUDIT_GET_DIFFS_NO_DIFFS:
222		if (buf != NULL)
223			free(buf);
224		*bufptr = NULL;
225		break;
226	case AUDIT_GET_DIFFS_CRONTAB:
227		if (buf != NULL) {
228			if (strlen(buf) != 0) {
229				*bufptr = buf;
230			} else {
231				r = AUDIT_GET_DIFFS_NO_DIFFS;
232				*bufptr = NULL;
233			}
234		}
235		break;
236	case AUDIT_GET_DIFFS_NO_CRONTAB:
237		if (buf != NULL) {
238			if (strlen(buf) != 0) {
239				*bufptr = buf;
240			} else {
241				*bufptr = NULL;
242				free(buf);
243			}
244		}
245		break;
246	}
247
248	return (r);
249}
250
251/*
252 * audit_crontab_not_allowed determines if we have a case that should be audited
253 * but we can't.  If auditing is enabled but the current process is not
254 * audited, then the ruid of the user doing the editing must be the owner
255 * id of the file to be edited.
256 *
257 * When audit_crontab_not_allowed is called, ruid is for the crontab file
258 * to be modified or created.
259 */
260
261#define	PWD_BUFFER_SIZE	512
262
263int
264audit_crontab_not_allowed(uid_t ruid, char *user) {
265	struct passwd		pwd;
266	char			buffer[PWD_BUFFER_SIZE];
267	int			rc = 0;		/* 0 == allow */
268
269	if (!cannot_audit(0)) {			/* allow access if audit off */
270		if (getpwnam_r(user, &pwd, buffer, PWD_BUFFER_SIZE) == NULL) {
271			rc = 1;			/* deny access if invalid */
272		} else if (ruid == pwd.pw_uid)
273			rc = 0;			/* editing their own crontab */
274		else
275			rc = audit_crontab_process_not_audited();
276	}
277	return (rc);
278}
279
280int
281audit_crontab_process_not_audited() {
282	struct auditpinfo_addr	info;
283	int	rc;
284
285	info.ap_pid = getpid();
286	if (auditon(A_GETPINFO_ADDR, (caddr_t)&info, sizeof (info)) != 0)
287		rc = 0;			/* audit failure: not enabled */
288	else
289		rc = (info.ap_auid == AU_NOAUDITID);
290
291	return (rc);
292}
293