xref: /titanic_41/usr/src/lib/libbsm/common/audit_plugin.c (revision fcf3ce441efd61da9bb2884968af01cb7c1452cc)
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 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  *
25  * private interfaces for auditd plugins and auditd.
26  */
27 
28 #include <bsm/audit.h>
29 #include <bsm/audit_record.h>
30 #include <bsm/audit_uevents.h>
31 #include <bsm/libbsm.h>
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <libintl.h>
35 #include <pthread.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <sys/file.h>
40 #include <sys/stat.h>
41 #include <sys/types.h>
42 #include <syslog.h>
43 #include <unistd.h>
44 #include <wait.h>
45 #include "audit_plugin.h"
46 
47 static char	auditwarn[] = "/etc/security/audit_warn";
48 static pthread_mutex_t	syslog_lock;
49 
50 static void
51 init_syslog_mutex()
52 {
53 	(void) pthread_mutex_init(&syslog_lock, NULL);
54 }
55 
56 /*
57  * audit_syslog() -- generate syslog messages from threads that use
58  * different severity, facility code, and application names.
59  *
60  * syslog(3C) is thread safe, but the set openlog() / syslog() /
61  * closelog() is not.
62  *
63  * Assumption:  the app_name and facility code are paired, i.e.,
64  * if the facility code for this call is the same as for the
65  * the previous, the app_name hasn't changed.
66  */
67 void
68 __audit_syslog(
69 	const char *app_name,
70 	int flags,
71 	int facility,
72 	int severity,
73 	const char *message)
74 {
75 	static pthread_once_t	once_control = PTHREAD_ONCE_INIT;
76 	static int		logopen = 0;
77 	static int		prev_facility = -1;
78 
79 	(void) pthread_once(&once_control, init_syslog_mutex);
80 
81 	(void) pthread_mutex_lock(&syslog_lock);
82 	if (prev_facility != facility) {
83 		if (logopen)
84 			closelog();
85 		openlog(app_name, flags, facility);
86 		syslog(severity, "%s", message);
87 		(void) pthread_mutex_unlock(&syslog_lock);
88 	} else {
89 		syslog(severity, "%s", message);
90 		(void) pthread_mutex_unlock(&syslog_lock);
91 	}
92 }
93 
94 /*
95  * __audit_dowarn - invoke the shell script auditwarn to notify the
96  *	adminstrator about a given problem.
97  * parameters -
98  *	option - what the problem is
99  *	text - when used with options soft and hard: which file was being
100  *		   used when the filesystem filled up
101  *	       when used with the plugin option:  error detail
102  *	count - used with various options: how many times auditwarn has
103  *		been called for this problem since it was last cleared.
104  */
105 void
106 __audit_dowarn(char *option, char *text, int count)
107 {
108 	pid_t		pid;
109 	int		st;
110 	char		countstr[5];
111 	char		warnstring[80];
112 	char		empty[1] = "";
113 
114 	if ((pid = fork1()) == -1) {
115 		__audit_syslog("auditd", LOG_PID | LOG_ODELAY | LOG_CONS,
116 		    LOG_DAEMON, LOG_ALERT, gettext("audit_warn fork failed\n"));
117 		return;
118 	}
119 	if (pid != 0) {
120 		(void) waitpid(pid, &st, 0);
121 		return;
122 	}
123 	(void) sprintf(countstr, "%d", count);
124 	if (text == NULL)
125 		text = empty;
126 
127 	if (strcmp(option, "soft") == 0 || strcmp(option, "hard") == 0)
128 		(void) execl(auditwarn, auditwarn, option, text, 0);
129 
130 	else if (strcmp(option, "allhard") == 0 ||
131 	    strcmp(option, "getacdir") == 0)
132 		(void) execl(auditwarn, auditwarn, option, countstr, 0);
133 	else if (strcmp(option, "plugin") == 0)
134 		(void) execl(auditwarn, auditwarn, option, text, countstr, 0);
135 	else
136 		(void) execl(auditwarn, auditwarn, option, 0);
137 	/*
138 	 * (execl failed)
139 	 */
140 	if (strcmp(option, "soft") == 0)
141 		(void) sprintf(warnstring,
142 		    gettext("soft limit in %s.\n"), text);
143 	else if (strcmp(option, "hard") == 0)
144 		(void) sprintf(warnstring,
145 		    gettext("hard limit in %s.\n"), text);
146 	else if (strcmp(option, "allhard") == 0)
147 		(void) sprintf(warnstring,
148 		    gettext("All audit filesystems are full.\n"));
149 	else if (strcmp(option, "getacmin") == 0)
150 		(void) sprintf(warnstring,
151 		    gettext("audit_control minfree error.\n"));
152 	else if (strcmp(option, "getacdir") == 0)
153 		(void) sprintf(warnstring,
154 		    gettext("audit_control directory error.\n"));
155 	else
156 		(void) sprintf(warnstring,
157 		    gettext("error %s.\n"), option);
158 
159 	__audit_syslog("auditd", LOG_PID | LOG_ODELAY | LOG_CONS, LOG_AUTH,
160 	    LOG_ALERT, (const char *)warnstring);
161 
162 	exit(1);
163 }
164 
165 /*
166  * __audit_dowarn2 - invoke the shell script auditwarn to notify the
167  *	adminstrator about a given problem.
168  * parameters -
169  *	option - what the problem is
170  *	name - entity reporting the problem (ie, plugin name)
171  *	error - error string
172  *	text - when used with options soft and hard: which file was being
173  *		   used when the filesystem filled up
174  *	       when used with the plugin option:  error detail
175  *	count - used with various options: how many times auditwarn has
176  *		been called for this problem since it was last cleared.
177  */
178 void
179 __audit_dowarn2(char *option, char *name, char *error, char *text, int count)
180 {
181 	pid_t		pid;
182 	int		st;
183 	char		countstr[5];
184 	char		warnstring[80];
185 	char		empty[4] = "...";
186 	char		none[3] = "--";
187 
188 	if ((pid = fork()) == -1) {
189 		__audit_syslog("auditd", LOG_PID | LOG_ODELAY | LOG_CONS,
190 		    LOG_DAEMON, LOG_ALERT, gettext("audit_warn fork failed\n"));
191 		return;
192 	}
193 	if (pid != 0) {
194 		(void) waitpid(pid, &st, 0);
195 		return;
196 	}
197 	(void) sprintf(countstr, "%d", count);
198 	if ((text == NULL) || (*text == '\0'))
199 		text = empty;
200 	if ((name == NULL) || (*name == '\0'))
201 		name = none;
202 
203 	(void) execl(auditwarn, auditwarn, option, name, error, text,
204 	    countstr, 0);
205 
206 	/*
207 	 * (execl failed)
208 	 */
209 	(void) sprintf(warnstring,
210 	    gettext("audit_control plugin error: %s\n"), text);
211 
212 	__audit_syslog("auditd", LOG_PID | LOG_ODELAY | LOG_CONS, LOG_AUTH,
213 	    LOG_ALERT, (const char *)warnstring);
214 
215 	exit(1);
216 }
217 
218 /*
219  * logpost - post the new audit log file name to audit_data.
220  *
221  * This is not re-entrant code; it is called from auditd.c when
222  * audit_binfile.so is not running and from binfile after auditd
223  * is done.
224  */
225 int
226 __logpost(char *name)
227 {
228 	char	buffer[MAXPATHLEN];
229 	char	empty[] = "";
230 
231 	static int	first = 1;
232 	static char	auditdata[] = AUDITDATAFILE;
233 	static int	audit_data_fd; /* file descriptor of audit_data */
234 
235 	if (first) {
236 		first = 0;
237 		/*
238 		 * Open the audit_data file. Use O_APPEND so that the contents
239 		 * are not destroyed if there is another auditd running.
240 		 */
241 		if ((audit_data_fd = open(auditdata,
242 		    O_RDWR | O_APPEND | O_CREAT, 0660)) < 0) {
243 			__audit_dowarn("tmpfile", "", 0);
244 			return (1);
245 		}
246 	}
247 	if (name == NULL)
248 		name = empty;
249 
250 	(void) snprintf(buffer, sizeof (buffer), "%d:%s\n",
251 	    (int)getpid(), name);
252 
253 	(void) ftruncate(audit_data_fd, (off_t)0);
254 	(void) write(audit_data_fd, buffer, strlen(buffer));
255 	(void) fsync(audit_data_fd);
256 
257 	return (0);
258 }
259 
260 /*
261  * debug use - open a file for auditd and its plugins for debug
262  */
263 FILE *
264 __auditd_debug_file_open() {
265 	static FILE	*fp = NULL;
266 
267 	if (fp != NULL)
268 		return (fp);
269 	if ((fp = fopen("/var/audit/dump", "aF")) == NULL)
270 		(void) fprintf(stderr, "failed to open debug file:  %s\n",
271 		    strerror(errno));
272 
273 	return (fp);
274 }
275