syslog.c revision b695575577bae0337af339d76949713bfe1c9013
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/*
23 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#include <sys/fm/protocol.h>
28#include <sys/strlog.h>
29#include <sys/log.h>
30
31#include <fm/fmd_api.h>
32#include <fm/fmd_msg.h>
33
34#include <stropts.h>
35#include <strings.h>
36#include <syslog.h>
37#include <alloca.h>
38#include <unistd.h>
39#include <stdlib.h>
40#include <errno.h>
41#include <fcntl.h>
42
43static struct stats {
44	fmd_stat_t bad_vers;
45	fmd_stat_t bad_code;
46	fmd_stat_t log_err;
47	fmd_stat_t msg_err;
48	fmd_stat_t no_msg;
49} syslog_stats = {
50	{ "bad_vers", FMD_TYPE_UINT64, "event version is missing or invalid" },
51	{ "bad_code", FMD_TYPE_UINT64, "event code has no dictionary name" },
52	{ "log_err", FMD_TYPE_UINT64, "failed to log message to log(7D)" },
53	{ "msg_err", FMD_TYPE_UINT64, "failed to log message to sysmsg(7D)" },
54	{ "no_msg", FMD_TYPE_UINT64, "message logging suppressed" }
55};
56
57static const struct facility {
58	const char *fac_name;
59	int fac_value;
60} syslog_facs[] = {
61	{ "LOG_DAEMON", LOG_DAEMON },
62	{ "LOG_LOCAL0", LOG_LOCAL0 },
63	{ "LOG_LOCAL1", LOG_LOCAL1 },
64	{ "LOG_LOCAL2", LOG_LOCAL2 },
65	{ "LOG_LOCAL3", LOG_LOCAL3 },
66	{ "LOG_LOCAL4", LOG_LOCAL4 },
67	{ "LOG_LOCAL5", LOG_LOCAL5 },
68	{ "LOG_LOCAL6", LOG_LOCAL6 },
69	{ "LOG_LOCAL7", LOG_LOCAL7 },
70	{ NULL, 0 }
71};
72
73static fmd_msg_hdl_t *syslog_msghdl; /* handle for libfmd_msg calls */
74static int syslog_msgall;	/* set to message all faults */
75static log_ctl_t syslog_ctl;	/* log(7D) meta-data for each msg */
76static int syslog_logfd = -1;	/* log(7D) file descriptor */
77static int syslog_msgfd = -1;	/* sysmsg(7D) file descriptor */
78static int syslog_file;		/* log to syslog_logfd */
79static int syslog_cons;		/* log to syslog_msgfd */
80static const char SYSLOG_POINTER[] = "syslog-msgs-pointer";
81
82/*
83 * Ideally we would just use syslog(3C) for outputting our messages, but our
84 * messaging standard defines a nice multi-line format and syslogd(1M) is very
85 * inflexible and stupid when it comes to multi-line messages.  It pulls data
86 * out of log(7D) and splits it up by \n, printing each line to the console
87 * with its usual prefix of date and sender; it uses the same behavior for the
88 * messages file as well.  Further, syslog(3C) provides no CE_CONT equivalent
89 * for userland callers (which at least works around repeated file prefixing).
90 * So with a multi-line message format, your file and console end up like this:
91 *
92 * Dec 02 18:08:40 hostname this is my nicely formatted
93 * Dec 02 18:08:40 hostname message designed for 80 cols
94 * ...
95 *
96 * To resolve these issues, we use our own syslog_emit() wrapper to emit
97 * messages and some knowledge of how the Solaris log drivers work.  We first
98 * construct an enlarged format string containing the appropriate msgid(1).
99 * We then format the caller's message using the provided format and buffer.
100 * We send this message to log(7D) using putmsg() with SL_CONSOLE | SL_LOGONLY
101 * set in the log_ctl_t.  The log driver allows us to set SL_LOGONLY when we
102 * construct messages ourself, indicating that syslogd should only emit the
103 * message to /var/adm/messages and any remote hosts, and skip the console.
104 * Then we emit the message a second time, without the special prefix, to the
105 * sysmsg(7D) device, which handles console redirection and also permits us
106 * to output any characters we like to the console, including \n and \r.
107 */
108static void
109syslog_emit(fmd_hdl_t *hdl, const char *msg)
110{
111	struct strbuf ctl, dat;
112	uint32_t msgid;
113
114	char *buf;
115	size_t buflen;
116
117	const char *format = "fmd: [ID %u FACILITY_AND_PRIORITY] %s";
118	STRLOG_MAKE_MSGID(format, msgid);
119
120	buflen = snprintf(NULL, 0, format, msgid, msg);
121	buf = alloca(buflen + 1);
122	(void) snprintf(buf, buflen + 1, format, msgid, msg);
123
124	ctl.buf = (void *)&syslog_ctl;
125	ctl.len = sizeof (syslog_ctl);
126
127	dat.buf = buf;
128	dat.len = buflen + 1;
129
130	/*
131	 * The underlying log driver won't accept messages longer than
132	 * LOG_MAXPS bytes.  Therefore, messages which exceed this limit will
133	 * be truncated and appended with a pointer to the full message.
134	 */
135	if (dat.len > LOG_MAXPS) {
136		char *syslog_pointer, *p;
137		size_t plen;
138
139		if ((syslog_pointer = fmd_msg_gettext_id(syslog_msghdl, NULL,
140		    SYSLOG_POINTER)) == NULL) {
141			/*
142			 * This shouldn't happen, but if it does we'll just
143			 * truncate the message.
144			 */
145			buf[LOG_MAXPS - 1] = '\0';
146			dat.len = LOG_MAXPS;
147		} else {
148			plen = strlen(syslog_pointer) + 1;
149			buf[LOG_MAXPS - plen] = '\0';
150			/*
151			 * If possible, the pointer is appended after a newline
152			 */
153			if ((p = strrchr(buf, '\n')) == NULL)
154				p = &buf[LOG_MAXPS - plen];
155
156			(void) strcpy(p, syslog_pointer);
157			free(syslog_pointer);
158			dat.len = strlen(buf) + 1;
159		}
160	}
161	if (syslog_file && putmsg(syslog_logfd, &ctl, &dat, 0) != 0) {
162		fmd_hdl_debug(hdl, "putmsg failed: %s\n", strerror(errno));
163		syslog_stats.log_err.fmds_value.ui64++;
164	}
165
166	dat.buf = strchr(buf, ']');
167	dat.len -= (size_t)(dat.buf - buf);
168
169	dat.buf[0] = '\r'; /* overwrite ']' with carriage return */
170	dat.buf[1] = '\n'; /* overwrite ' ' with newline */
171
172	if (syslog_cons && write(syslog_msgfd, dat.buf, dat.len) != dat.len) {
173		fmd_hdl_debug(hdl, "write failed: %s\n", strerror(errno));
174		syslog_stats.msg_err.fmds_value.ui64++;
175	}
176}
177
178/*ARGSUSED*/
179static void
180syslog_recv(fmd_hdl_t *hdl, fmd_event_t *ep, nvlist_t *nvl, const char *class)
181{
182	uint8_t version;
183	boolean_t domsg;
184	char *msg;
185
186	if (nvlist_lookup_uint8(nvl, FM_VERSION, &version) != 0 ||
187	    version > FM_SUSPECT_VERSION) {
188		fmd_hdl_debug(hdl, "invalid event version: %u\n", version);
189		syslog_stats.bad_vers.fmds_value.ui64++;
190		return; /* invalid event version */
191	}
192
193	if (!syslog_msgall && nvlist_lookup_boolean_value(nvl,
194	    FM_SUSPECT_MESSAGE, &domsg) == 0 && !domsg) {
195		fmd_hdl_debug(hdl, "%s requested no message\n", class);
196		syslog_stats.no_msg.fmds_value.ui64++;
197		return; /* event is not to be messaged */
198	}
199
200
201	if ((msg = fmd_msg_gettext_nv(syslog_msghdl, NULL, nvl)) == NULL) {
202		fmd_hdl_debug(hdl, "failed to format message");
203		syslog_stats.bad_code.fmds_value.ui64++;
204		return; /* libfmd_msg error */
205	}
206
207	syslog_emit(hdl, msg);
208	free(msg);
209}
210
211static const fmd_prop_t fmd_props[] = {
212	{ "console", FMD_TYPE_BOOL, "true" },
213	{ "facility", FMD_TYPE_STRING, "LOG_DAEMON" },
214	{ "gmt", FMD_TYPE_BOOL, "false" },
215	{ "syslogd", FMD_TYPE_BOOL, "true" },
216	{ "url", FMD_TYPE_STRING, "http://sun.com/msg/" },
217	{ "message_all", FMD_TYPE_BOOL, "false" },
218	{ NULL, 0, NULL }
219};
220
221static const fmd_hdl_ops_t fmd_ops = {
222	syslog_recv,	/* fmdo_recv */
223	NULL,		/* fmdo_timeout */
224	NULL,		/* fmdo_close */
225	NULL,		/* fmdo_stats */
226	NULL,		/* fmdo_gc */
227};
228
229static const fmd_hdl_info_t fmd_info = {
230	"Syslog Messaging Agent", "1.0", &fmd_ops, fmd_props
231};
232
233void
234_fmd_init(fmd_hdl_t *hdl)
235{
236	const struct facility *fp;
237	char *facname, *tz, *rootdir, *urlbase;
238
239	if (fmd_hdl_register(hdl, FMD_API_VERSION, &fmd_info) != 0)
240		return; /* invalid data in configuration file */
241
242	(void) fmd_stat_create(hdl, FMD_STAT_NOALLOC, sizeof (syslog_stats) /
243	    sizeof (fmd_stat_t), (fmd_stat_t *)&syslog_stats);
244
245	if ((syslog_logfd = open("/dev/conslog", O_WRONLY | O_NOCTTY)) == -1)
246		fmd_hdl_abort(hdl, "syslog-msgs failed to open /dev/conslog");
247
248	if ((syslog_msgfd = open("/dev/sysmsg", O_WRONLY | O_NOCTTY)) == -1)
249		fmd_hdl_abort(hdl, "syslog-msgs failed to open /dev/sysmsg");
250
251	/*
252	 * If the "gmt" property is set to true, force our EVENT-TIME to be
253	 * reported in GMT time; otherwise we use localtime.  tzset() affects
254	 * the results of subsequent calls to strftime(3C) above.
255	 */
256	if (fmd_prop_get_int32(hdl, "gmt") == FMD_B_TRUE &&
257	    ((tz = getenv("TZ")) == NULL || strcmp(tz, "GMT") != 0)) {
258		(void) putenv(fmd_hdl_strdup(hdl, "TZ=GMT", FMD_SLEEP));
259		tzset(); /* reload env */
260	}
261
262	/*
263	 * Look up the value of the "facility" property and use it to determine
264	 * what syslog LOG_* facility value we use to fill in our log_ctl_t.
265	 * The details of our logging method are described above syslog_emit().
266	 */
267	facname = fmd_prop_get_string(hdl, "facility");
268
269	for (fp = syslog_facs; fp->fac_name != NULL; fp++) {
270		if (strcmp(fp->fac_name, facname) == 0)
271			break;
272	}
273
274	if (fp->fac_name == NULL)
275		fmd_hdl_abort(hdl, "invalid 'facility' setting: %s\n", facname);
276
277	fmd_prop_free_string(hdl, facname);
278	syslog_ctl.pri = fp->fac_value;
279	syslog_ctl.flags = SL_CONSOLE | SL_LOGONLY;
280
281	/*
282	 * Cache any properties we use every time we receive an event and
283	 * subscribe to list.suspect events regardless of the .conf file.
284	 */
285	syslog_file = fmd_prop_get_int32(hdl, "syslogd");
286	syslog_cons = fmd_prop_get_int32(hdl, "console");
287	syslog_msgall = fmd_prop_get_int32(hdl, "message_all");
288
289	rootdir = fmd_prop_get_string(hdl, "fmd.rootdir");
290	syslog_msghdl = fmd_msg_init(rootdir, FMD_MSG_VERSION);
291	fmd_prop_free_string(hdl, rootdir);
292
293	if (syslog_msghdl == NULL)
294		fmd_hdl_abort(hdl, "failed to initialize libfmd_msg");
295
296	urlbase = fmd_prop_get_string(hdl, "url");
297	(void) fmd_msg_url_set(syslog_msghdl, urlbase);
298	fmd_prop_free_string(hdl, urlbase);
299
300	fmd_hdl_subscribe(hdl, FM_LIST_SUSPECT_CLASS);
301	fmd_hdl_subscribe(hdl, FM_LIST_REPAIRED_CLASS);
302	fmd_hdl_subscribe(hdl, FM_LIST_RESOLVED_CLASS);
303}
304
305/*ARGSUSED*/
306void
307_fmd_fini(fmd_hdl_t *hdl)
308{
309	fmd_msg_fini(syslog_msghdl);
310	(void) close(syslog_logfd);
311	(void) close(syslog_msgfd);
312}
313