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