1/*
2 * Copyright (c) 1998-2001 Sendmail, Inc. and its suppliers.
3 *	All rights reserved.
4 * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
5 * Copyright (c) 1988, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * By using this file, you agree to the terms and conditions set
9 * forth in the LICENSE file which can be found at the top level of
10 * the sendmail distribution.
11 *
12 */
13
14#pragma ident	"%Z%%M%	%I%	%E% SMI"
15
16#include <sendmail.h>
17
18SM_RCSID("@(#)$Id: arpadate.c,v 8.31 2006/08/15 23:24:55 ca Exp $")
19
20/*
21**  ARPADATE -- Create date in ARPANET format
22**
23**	Parameters:
24**		ud -- unix style date string.  if NULL, one is created.
25**
26**	Returns:
27**		pointer to an ARPANET date field
28**
29**	Side Effects:
30**		none
31**
32**	WARNING:
33**		date is stored in a local buffer -- subsequent
34**		calls will overwrite.
35**
36**	Bugs:
37**		Timezone is computed from local time, rather than
38**		from wherever (and whenever) the message was sent.
39**		To do better is very hard.
40**
41**		Some sites are now inserting the timezone into the
42**		local date.  This routine should figure out what
43**		the format is and work appropriately.
44*/
45
46#ifndef TZNAME_MAX
47# define TZNAME_MAX	50	/* max size of timezone */
48#endif /* ! TZNAME_MAX */
49
50/* values for TZ_TYPE */
51#define TZ_NONE		0	/* no character timezone support */
52#define TZ_TM_NAME	1	/* use tm->tm_name */
53#define TZ_TM_ZONE	2	/* use tm->tm_zone */
54#define TZ_TZNAME	3	/* use tzname[] */
55#define TZ_TIMEZONE	4	/* use timezone() */
56
57char *
58arpadate(ud)
59	register char *ud;
60{
61	register char *p;
62	register char *q;
63	register int off;
64	register int i;
65	register struct tm *lt;
66	time_t t;
67	struct tm gmt;
68	char *tz;
69	static char b[43 + TZNAME_MAX];
70
71	/*
72	**  Get current time.
73	**	This will be used if a null argument is passed and
74	**	to resolve the timezone.
75	*/
76
77	/* SM_REQUIRE(ud == NULL || strlen(ud) >= 23); */
78	t = curtime();
79	if (ud == NULL)
80		ud = ctime(&t);
81
82	/*
83	**  Crack the UNIX date line in a singularly unoriginal way.
84	*/
85
86	q = b;
87
88	p = &ud[0];		/* Mon */
89	*q++ = *p++;
90	*q++ = *p++;
91	*q++ = *p++;
92	*q++ = ',';
93	*q++ = ' ';
94
95	p = &ud[8];		/* 16 */
96	if (*p == ' ')
97		p++;
98	else
99		*q++ = *p++;
100	*q++ = *p++;
101	*q++ = ' ';
102
103	p = &ud[4];		/* Sep */
104	*q++ = *p++;
105	*q++ = *p++;
106	*q++ = *p++;
107	*q++ = ' ';
108
109	p = &ud[20];		/* 1979 */
110	*q++ = *p++;
111	*q++ = *p++;
112	*q++ = *p++;
113	*q++ = *p++;
114	*q++ = ' ';
115
116	p = &ud[11];		/* 01:03:52 */
117	for (i = 8; i > 0; i--)
118		*q++ = *p++;
119
120	/*
121	**  should really get the timezone from the time in "ud" (which
122	**  is only different if a non-null arg was passed which is different
123	**  from the current time), but for all practical purposes, returning
124	**  the current local zone will do (its all that is ever needed).
125	*/
126
127	gmt = *gmtime(&t);
128	lt = localtime(&t);
129
130	off = (lt->tm_hour - gmt.tm_hour) * 60 + lt->tm_min - gmt.tm_min;
131
132	/* assume that offset isn't more than a day ... */
133	if (lt->tm_year < gmt.tm_year)
134		off -= 24 * 60;
135	else if (lt->tm_year > gmt.tm_year)
136		off += 24 * 60;
137	else if (lt->tm_yday < gmt.tm_yday)
138		off -= 24 * 60;
139	else if (lt->tm_yday > gmt.tm_yday)
140		off += 24 * 60;
141
142	*q++ = ' ';
143	if (off == 0)
144	{
145		*q++ = 'G';
146		*q++ = 'M';
147		*q++ = 'T';
148	}
149	else
150	{
151		tz = NULL;
152#if TZ_TYPE == TZ_TM_NAME
153		tz = lt->tm_name;
154#endif /* TZ_TYPE == TZ_TM_NAME */
155#if TZ_TYPE == TZ_TM_ZONE
156		tz = lt->tm_zone;
157#endif /* TZ_TYPE == TZ_TM_ZONE */
158#if TZ_TYPE == TZ_TZNAME
159		{
160			extern char *tzname[];
161
162			if (lt->tm_isdst > 0)
163				tz = tzname[1];
164			else if (lt->tm_isdst == 0)
165				tz = tzname[0];
166			else
167				tz = NULL;
168		}
169#endif /* TZ_TYPE == TZ_TZNAME */
170#if TZ_TYPE == TZ_TIMEZONE
171		{
172			extern char *timezone();
173
174			tz = timezone(off, lt->tm_isdst);
175		}
176#endif /* TZ_TYPE == TZ_TIMEZONE */
177		if (off < 0)
178		{
179			off = -off;
180			*q++ = '-';
181		}
182		else
183			*q++ = '+';
184
185		if (off >= 24*60)		/* should be impossible */
186			off = 23*60+59;		/* if not, insert silly value */
187
188		*q++ = (off / 600) + '0';
189		*q++ = (off / 60) % 10 + '0';
190		off %= 60;
191		*q++ = (off / 10) + '0';
192		*q++ = (off % 10) + '0';
193		if (tz != NULL && *tz != '\0')
194		{
195			*q++ = ' ';
196			*q++ = '(';
197			while (*tz != '\0' && q < &b[sizeof(b) - 3])
198				*q++ = *tz++;
199			*q++ = ')';
200		}
201	}
202	*q = '\0';
203
204	return b;
205}
206