1 /* $NetBSD: syslog.c,v 1.2 2021/08/14 16:14:58 christos Exp $ */
2
3 /* $OpenBSD: syslog.c,v 1.29 2007/11/09 18:40:19 millert Exp $ */
4 /*
5 * Copyright (c) 1983, 1988, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
34 __RCSID("$NetBSD: syslog.c,v 1.2 2021/08/14 16:14:58 christos Exp $");
35
36 #include "portable.h"
37
38 #include <sys/types.h>
39 #include <ac/socket.h>
40 #include <ac/syslog.h>
41 #include <sys/uio.h>
42 #include <sys/un.h>
43 #include <netdb.h>
44
45 #include <ac/errno.h>
46 #include <fcntl.h>
47 #include <paths.h>
48 #include <stdio.h>
49 #include <ac/string.h>
50 #include <ac/time.h>
51 #include <ac/unistd.h>
52 #include <ac/stdarg.h>
53
54 #include "slap.h"
55 #include "lutil.h"
56
57 static int LogType = SOCK_DGRAM; /* type of socket connection */
58 static int LogFile = -1; /* fd for log */
59 static int connected; /* have done connect */
60 static int LogStat; /* status bits, set by openlog() */
61 static const char *LogTag; /* string to tag the entry with */
62 static int LogFacility = LOG_USER; /* default facility code */
63
64 static void disconnectlog(void);
65 static void connectlog(void);
66
67 static void my_localtime(const time_t *t, struct tm *tm);
68
69 /*
70 * syslog
71 * print message on log file; output is intended for syslogd(8).
72 */
73 void
syslog(int pri,const char * fmt,...)74 syslog(int pri, const char *fmt, ...)
75 {
76 va_list ap;
77 char *p, *pend;
78 #define TBUF_LEN 2048
79 #define FMT_LEN 1024
80 char tbuf[TBUF_LEN];
81 int cnt;
82 int error;
83 int tbuf_left, prlen;
84
85 va_start(ap, fmt);
86
87 /* Check for invalid bits. */
88 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
89 if (LogTest(LOG_ERR))
90 lutil_debug(slap_debug, LOG_ERR,
91 "syslog: unknown facility/priority: %x", pri);
92 pri &= LOG_PRIMASK|LOG_FACMASK;
93 }
94
95 /* Set default facility if none specified. */
96 if ((pri & LOG_FACMASK) == 0)
97 pri |= LogFacility;
98
99 p = tbuf;
100 pend = p + TBUF_LEN;
101
102 *p++ = '<';
103 p += sprintf(p, "%d", pri);
104 *p++ = '>';
105
106 #if 0
107 (void)time(&now);
108 my_localtime(&now, &tm);
109 p += strftime(p, tbuf_left, "%h %e %T ", &tm);
110 #endif
111
112 if (LogTag != NULL) {
113 p = lutil_strcopy(p, LogTag);
114 }
115 if (LogStat & LOG_PID) {
116 *p++ = '[';
117 p += sprintf(p, "%ld", (long)getpid());
118 *p++ = ']';
119 }
120 if (LogTag != NULL) {
121 *p++ = ':';
122 *p++ = ' ';
123 }
124
125 tbuf_left = pend - p;
126 prlen = vsnprintf(p, tbuf_left, fmt, ap);
127 va_end(ap);
128 if (prlen < 0)
129 prlen = 0;
130 else if (prlen >= tbuf_left)
131 prlen = tbuf_left - 1;
132 p += prlen;
133 cnt = p - tbuf;
134
135 /* Get connected, output the message to the local logger. */
136 if (LogFile == -1)
137 openlog(LogTag, LogStat, 0);
138 connectlog();
139
140 /*
141 * If the send() failed, there are two likely scenarios:
142 * 1) syslogd was restarted
143 * 2) /dev/log is out of socket buffer space
144 * We attempt to reconnect to /dev/log to take care of
145 * case #1 and keep send()ing data to cover case #2
146 * to give syslogd a chance to empty its socket buffer.
147 */
148 if ((error = send(LogFile, tbuf, cnt, 0)) < 0) {
149 if (errno != ENOBUFS) {
150 disconnectlog();
151 connectlog();
152 }
153 do {
154 usleep(1);
155 if ((error = send(LogFile, tbuf, cnt, 0)) >= 0)
156 break;
157 } while (errno == ENOBUFS);
158 }
159 }
160
161 static void
disconnectlog(void)162 disconnectlog(void)
163 {
164 /*
165 * If the user closed the FD and opened another in the same slot,
166 * that's their problem. They should close it before calling on
167 * system services.
168 */
169 if (LogFile != -1) {
170 close(LogFile);
171 LogFile = -1;
172 }
173 connected = 0; /* retry connect */
174 }
175
176 static void
connectlog(void)177 connectlog(void)
178 {
179 struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */
180
181 if (LogFile == -1) {
182 if ((LogFile = socket(AF_UNIX, LogType, 0)) == -1)
183 return;
184 (void)fcntl(LogFile, F_SETFD, FD_CLOEXEC);
185 }
186 if (LogFile != -1 && !connected) {
187 memset(&SyslogAddr, '\0', sizeof(SyslogAddr));
188 #ifdef _BSD
189 SyslogAddr.sun_len = sizeof(SyslogAddr);
190 #endif
191 SyslogAddr.sun_family = AF_UNIX;
192 strncpy(SyslogAddr.sun_path, _PATH_LOG,
193 sizeof(SyslogAddr.sun_path));
194 if (connect(LogFile, (struct sockaddr *)&SyslogAddr,
195 sizeof(SyslogAddr)) == -1) {
196 (void)close(LogFile);
197 LogFile = -1;
198 } else
199 connected = 1;
200 }
201 }
202
203 void
openlog(const char * ident,int logstat,int logfac)204 openlog(const char *ident, int logstat, int logfac)
205 {
206 if (ident != NULL)
207 LogTag = ident;
208 LogStat = logstat;
209 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
210 LogFacility = logfac;
211
212 if (LogStat & LOG_NDELAY) /* open immediately */
213 connectlog();
214 }
215
216 void
closelog()217 closelog()
218 {
219 (void)close(LogFile);
220 LogFile = -1;
221 connected = 0;
222 LogTag = NULL;
223 }
224
225 #if 0
226 #define SECS_PER_HOUR (60 * 60)
227 #define SECS_PER_DAY (SECS_PER_HOUR * 24)
228
229 /* How many days come before each month (0-12). */
230 static const unsigned short int __mon_yday[2][13] =
231 {
232 /* Normal years. */
233 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
234 /* Leap years. */
235 { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
236 };
237
238 /* Compute the `struct tm' representation of *T,
239 and store year, yday, mon, mday, wday, hour, min, sec into *TP */
240 static void my_localtime(const time_t *t, struct tm *tm)
241 {
242 time_t days, rem, y;
243 const unsigned short int *ip;
244 int leap;
245
246 days = *t / SECS_PER_DAY;
247 rem = *t % SECS_PER_DAY;
248 rem -= timezone;
249 while (rem < 0)
250 {
251 rem += SECS_PER_DAY;
252 --days;
253 }
254 while (rem >= SECS_PER_DAY)
255 {
256 rem -= SECS_PER_DAY;
257 ++days;
258 }
259 tm->tm_hour = rem / SECS_PER_HOUR;
260 rem %= SECS_PER_HOUR;
261 tm->tm_min = rem / 60;
262 tm->tm_sec = rem % 60;
263 /* January 1, 1970 was a Thursday. */
264 tm->tm_wday = (4 + days) % 7;
265 if (tm->tm_wday < 0)
266 tm->tm_wday += 7;
267 y = 1970;
268
269 #define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
270 #define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
271 #define ISLEAP(y) ((y) % 4 == 0 && ((y) % 100 != 0 || (y) % 400 == 0))
272
273 leap = ISLEAP(y);
274 while (days < 0 || days >= (leap ? 366 : 365))
275 {
276 /* Guess a corrected year, assuming 365 days per year. */
277 time_t yg = y + days / 365 - (days % 365 < 0);
278
279 /* Adjust DAYS and Y to match the guessed year. */
280 days -= ((yg - y) * 365
281 + LEAPS_THRU_END_OF (yg - 1)
282 - LEAPS_THRU_END_OF (y - 1));
283 y = yg;
284 }
285 tm->tm_year = y - 1900;
286 tm->tm_yday = days;
287 ip = __mon_yday[leap];
288 for (y = 11; days < (long int) ip[y]; --y)
289 continue;
290 days -= ip[y];
291 tm->tm_mon = y;
292 tm->tm_mday = days + 1;
293 }
294 #endif
295