1/*
2 * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
3 * Copyright (c) 2009 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Brian Ginsbach.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "lint.h"
32#include "file64.h"
33#include <sys/types.h>
34#include <errno.h>
35#include <stdio.h>
36#include <stdlib.h>
37#include <string.h>
38#include <time.h>
39#include <unistd.h>
40#include <sys/stat.h>
41
42#define	TMSENTINEL	(-1)
43
44
45/*
46 * getdate_err is set to one of the following values on error.
47 *
48 * 1	The DATEMSK environment variable is null or undefined.
49 * 2	The template file cannot be opened for reading.
50 * 3	Failed to get file status information.
51 * 4	Template file is not a regular file.
52 * 5	Encountered an error while reading the template file.
53 * 6	Cannot allocate memory.
54 * 7	Input string does not match any line in the template.
55 * 8	Input string is invalid (for example, February 31) or could not
56 *	be represented in a time_t.
57 *
58 * Note that on Solaris, getdate_err is possibly a function, to account
59 * for reentrancy.  See the code for getdate_err.c for details.
60 */
61
62
63#pragma	weak	_getdate = getdate
64struct tm *
65getdate(const char *str)
66{
67	char *datemsk, *line, *rp;
68	FILE *fp;
69	struct stat sb;
70	static struct tm rtm, tmnow;
71	struct tm *tmp, *rtmp = &rtm;
72	time_t now;
73	char buf[514];
74
75	if (((datemsk = getenv("DATEMSK")) == NULL) || *datemsk == '\0') {
76		getdate_err = 1;
77		return (NULL);
78	}
79
80	if (stat(datemsk, &sb) < 0) {
81		getdate_err = 3;
82		return (NULL);
83	}
84
85	if ((sb.st_mode & S_IFMT) != S_IFREG) {
86		getdate_err = 4;
87		return (NULL);
88	}
89
90	if ((fp = fopen(datemsk, "r")) == NULL) {
91		getdate_err = 2;
92		return (NULL);
93	}
94
95	/* loop through datemsk file */
96	errno = 0;
97	rp = NULL;
98
99	/*
100	 * The NetBSD implementation supports a rich flexible file format
101	 * with embedded escapes, etc.  We don't need any of that.  Solaris
102	 * just reads the template file and (undocumented!) requires that
103	 * each line not exceed 512 bytes, using a fixed buffer.   We could
104	 * improve on that, but this may grow the stack unreasonably, so
105	 * we keep it to the same 512 limit.  Some day we can be smarter.
106	 * (Note FreeBSD doesn't even have getdate(), and IMO nobody sane
107	 * should be using this crufty API.  strptime is better.)
108	 */
109
110	(void) memset(buf, 0, sizeof (buf));
111	while ((line = fgets(buf, sizeof (buf), fp)) != NULL) {
112		/*
113		 * If the buffer consumed the entire string, then
114		 * the input line was too long.  We just check to
115		 * see if the 2nd to last byte is set.  If it isn't,
116		 * then we hit a null byte first, and the line is
117		 * short enough.
118		 */
119		if (buf[sizeof (buf) - 2] != 0) {
120			getdate_err = 5;
121			(void) fclose(fp);
122			return (NULL);
123		}
124		/* initialize tmp with sentinels */
125		rtm.tm_sec = rtm.tm_min = rtm.tm_hour = TMSENTINEL;
126		rtm.tm_mday = rtm.tm_mon = rtm.tm_year = TMSENTINEL;
127		rtm.tm_wday = rtm.tm_yday = rtm.tm_isdst = TMSENTINEL;
128		rp = strptime(str, line, rtmp);
129		if (rp != NULL)
130			break;
131		errno = 0;
132	}
133	if (errno != 0 || ferror(fp)) {
134		if (errno == ENOMEM)
135			getdate_err = 6;
136		else
137			getdate_err = 5;
138		(void) fclose(fp);
139		return (NULL);
140	}
141	if (feof(fp) || (rp != NULL && *rp != '\0')) {
142		getdate_err = 7;
143		return (NULL);
144	}
145	(void) fclose(fp);
146
147	(void) time(&now);
148	tmp = localtime(&now);
149	tmnow = *tmp;
150
151	/*
152	 * This implementation does not accept setting the broken-down time
153	 * to anything other than the localtime().  It is not possible to
154	 * change the scanned timezone with %Z.
155	 *
156	 * Note IRIX and Solaris accept only the current zone for %Z.
157	 * XXX Is there any implementation that matches the standard?
158	 * XXX (Or am I reading the standard wrong?)
159	 *
160	 * Note: Neither XPG 6 (POSIX 2004) nor XPG 7 (POSIX 2008)
161	 * requires strptime(3) support for %Z.
162	 */
163
164	/*
165	 * Given only a weekday find the first matching weekday starting
166	 * with the current weekday and moving into the future.
167	 */
168	if (rtm.tm_wday != TMSENTINEL && rtm.tm_year == TMSENTINEL &&
169	    rtm.tm_mon == TMSENTINEL && rtm.tm_mday == TMSENTINEL) {
170		rtm.tm_year = tmnow.tm_year;
171		rtm.tm_mon = tmnow.tm_mon;
172		rtm.tm_mday = tmnow.tm_mday +
173		    (rtm.tm_wday - tmnow.tm_wday + 7) % 7;
174	}
175
176	/*
177	 * Given only a month (and no year) find the first matching month
178	 * starting with the current month and moving into the future.
179	 */
180	if (rtm.tm_mon != TMSENTINEL) {
181		if (rtm.tm_year == TMSENTINEL) {
182			rtm.tm_year = tmnow.tm_year +
183			    ((rtm.tm_mon < tmnow.tm_mon)? 1 : 0);
184		}
185		if (rtm.tm_mday == TMSENTINEL) {
186			/* assume the first of the month */
187			rtm.tm_mday = 1;
188			/*
189			 * XXX This isn't documented! Just observed behavior.
190			 *
191			 * Given the weekday find the first matching weekday
192			 * starting with the weekday of the first day of the
193			 * the month and moving into the future.
194			 */
195			if (rtm.tm_wday != TMSENTINEL) {
196				struct tm tm;
197
198				(void) memset(&tm, 0, sizeof (struct tm));
199				tm.tm_year = rtm.tm_year;
200				tm.tm_mon = rtm.tm_mon;
201				tm.tm_mday = 1;
202				(void) mktime(&tm);
203				rtm.tm_mday +=
204				    (rtm.tm_wday - tm.tm_wday + 7) % 7;
205			}
206		}
207	}
208
209	/*
210	 * Given no time of day assume the current time of day.
211	 */
212	if (rtm.tm_hour == TMSENTINEL &&
213	    rtm.tm_min == TMSENTINEL && rtm.tm_sec == TMSENTINEL) {
214		rtm.tm_hour = tmnow.tm_hour;
215		rtm.tm_min = tmnow.tm_min;
216		rtm.tm_sec = tmnow.tm_sec;
217	}
218	/*
219	 * Given an hour and no date, find the first matching hour starting
220	 * with the current hour and moving into the future
221	 */
222	if (rtm.tm_hour != TMSENTINEL &&
223	    rtm.tm_year == TMSENTINEL && rtm.tm_mon == TMSENTINEL &&
224	    rtm.tm_mday == TMSENTINEL) {
225		rtm.tm_year = tmnow.tm_year;
226		rtm.tm_mon = tmnow.tm_mon;
227		rtm.tm_mday = tmnow.tm_mday;
228		if (rtm.tm_hour < tmnow.tm_hour)
229			rtm.tm_hour += 24;
230	}
231
232	/*
233	 * Set to 'sane' values; mktime(3) does funny things otherwise.
234	 * No hours, no minutes, no seconds, no service.
235	 */
236	if (rtm.tm_hour == TMSENTINEL)
237		rtm.tm_hour = 0;
238	if (rtm.tm_min == TMSENTINEL)
239		rtm.tm_min = 0;
240	if (rtm.tm_sec == TMSENTINEL)
241		rtm.tm_sec = 0;
242
243	/*
244	 * Given only a year the values of month, day of month, day of year,
245	 * week day and is daylight (summer) time are unspecified.
246	 * (Specified on the Solaris man page not POSIX.)
247	 */
248	if (rtm.tm_year != TMSENTINEL &&
249	    rtm.tm_mon == TMSENTINEL && rtm.tm_mday == TMSENTINEL) {
250		rtm.tm_mon = 0;
251		rtm.tm_mday = 1;
252		/*
253		 * XXX More undocumented functionality but observed.
254		 *
255		 * Given the weekday find the first matching weekday
256		 * starting with the weekday of the first day of the
257		 * month and moving into the future.
258		 */
259		if (rtm.tm_wday != TMSENTINEL) {
260			struct tm tm;
261
262			(void) memset(&tm, 0, sizeof (struct tm));
263			tm.tm_year = rtm.tm_year;
264			tm.tm_mon = rtm.tm_mon;
265			tm.tm_mday = 1;
266			(void) mktime(&tm);
267			rtm.tm_mday += (rtm.tm_wday - tm.tm_wday + 7) % 7;
268		}
269	}
270
271	/*
272	 * Given only the century but no year within, the current year
273	 * is assumed.  (Specified on the Solaris man page not POSIX.)
274	 *
275	 * Warning ugly end case
276	 *
277	 * This is more work since strptime(3) doesn't "do the right thing".
278	 */
279	if (rtm.tm_year != TMSENTINEL && (rtm.tm_year - 1900) >= 0) {
280		rtm.tm_year -= 1900;
281		rtm.tm_year += (tmnow.tm_year % 100);
282	}
283
284	/*
285	 * mktime() will normalize all values and also check that the
286	 * value will fit into a time_t.
287	 *
288	 * This is only for POSIX correctness.	A date >= 1900 is
289	 * really ok, but using a time_t limits things.
290	 */
291	if (mktime(rtmp) < 0) {
292		getdate_err = 8;
293		return (NULL);
294	}
295
296	return (rtmp);
297}
298