xref: /openbsd-src/usr.bin/mail/head.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: head.c,v 1.6 2001/01/19 04:11:28 millert Exp $	*/
2 /*	$NetBSD: head.c,v 1.6 1996/12/28 07:11:03 tls Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 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. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)head.c	8.2 (Berkeley) 4/20/95";
40 #else
41 static char rcsid[] = "$OpenBSD: head.c,v 1.6 2001/01/19 04:11:28 millert Exp $";
42 #endif
43 #endif /* not lint */
44 
45 #include "rcv.h"
46 #include "extern.h"
47 
48 /*
49  * Mail -- a mail program
50  *
51  * Routines for processing and detecting headlines.
52  */
53 
54 /*
55  * See if the passed line buffer is a mail header.
56  * Return true if yes.  Note the extreme pains to
57  * accomodate all funny formats.
58  */
59 int
60 ishead(linebuf)
61 	char linebuf[];
62 {
63 	char *cp;
64 	struct headline hl;
65 	char parbuf[BUFSIZ];
66 
67 	cp = linebuf;
68 	if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' ||
69 	    *cp++ != ' ')
70 		return(0);
71 	parse(linebuf, &hl, parbuf);
72 	if (hl.l_from == NULL || hl.l_date == NULL) {
73 		fail(linebuf, "No from or date field");
74 		return(0);
75 	}
76 	if (!isdate(hl.l_date)) {
77 		fail(linebuf, "Date field not legal date");
78 		return(0);
79 	}
80 	/*
81 	 * I guess we got it!
82 	 */
83 	return(1);
84 }
85 
86 /*ARGSUSED*/
87 void
88 fail(linebuf, reason)
89 	char linebuf[], reason[];
90 {
91 
92 	/*
93 	if (value("debug") == NULL)
94 		return;
95 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
96 	*/
97 }
98 
99 /*
100  * Split a headline into its useful components.
101  * Copy the line into dynamic string space, then set
102  * pointers into the copied line in the passed headline
103  * structure.  Actually, it scans.
104  */
105 void
106 parse(line, hl, pbuf)
107 	char line[], pbuf[];
108 	struct headline *hl;
109 {
110 	char *cp, *sp;
111 	char word[LINESIZE];
112 
113 	hl->l_from = NULL;
114 	hl->l_tty = NULL;
115 	hl->l_date = NULL;
116 	cp = line;
117 	sp = pbuf;
118 	/*
119 	 * Skip over "From" first.
120 	 */
121 	cp = nextword(cp, word);
122 	cp = nextword(cp, word);
123 	if (*word)
124 		hl->l_from = copyin(word, &sp);
125 	if (cp != NULL && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
126 		cp = nextword(cp, word);
127 		hl->l_tty = copyin(word, &sp);
128 	}
129 	if (cp != NULL)
130 		hl->l_date = copyin(cp, &sp);
131 }
132 
133 /*
134  * Copy the string on the left into the string on the right
135  * and bump the right (reference) string pointer by the length.
136  * Thus, dynamically allocate space in the right string, copying
137  * the left string into it.
138  */
139 char *
140 copyin(src, space)
141 	char *src;
142 	char **space;
143 {
144 	char *cp, *top;
145 
146 	top = cp = *space;
147 	while ((*cp++ = *src++) != '\0')
148 		;
149 	*space = cp;
150 	return(top);
151 }
152 
153 /*
154  * Test to see if the passed string is a ctime(3) generated
155  * date string as documented in the manual.  The template
156  * below is used as the criterion of correctness.
157  * Also, we check for a possible trailing time zone using
158  * the tmztype template.
159  */
160 
161 /*
162  * 'A'	An upper case char
163  * 'a'	A lower case char
164  * ' '	A space
165  * '0'	A digit
166  * 'O'	A digit or space
167  * 'p'	A punctuation char
168  * 'P'	A punctuation char or space
169  * ':'	A colon
170  * 'N'	A new line
171  */
172 
173 /*
174  * Yuck.  If the mail file is created by Sys V (Solaris),
175  * there are no seconds in the time...
176  */
177 
178 /*
179  * If the mail is created by another program such as imapd, it might
180  * have timezone as <-|+>nnnn (-0800 for instance) at the end.
181  */
182 
183 static char *date_formats[] = {
184 	"Aaa Aaa O0 00:00:00 0000",	   /* Mon Jan 01 23:59:59 2001 */
185 	"Aaa Aaa O0 00:00:00 AAA 0000",	   /* Mon Jan 01 23:59:59 PST 2001 */
186 	"Aaa Aaa O0 00:00:00 0000 p0000",  /* Mon Jan 01 23:59:59 2001 -0800 */
187 	"Aaa Aaa O0 00:00 0000",	   /* Mon Jan 01 23:59 2001 */
188 	"Aaa Aaa O0 00:00 AAA 0000",	   /* Mon Jan 01 23:59 PST 2001 */
189 	"Aaa Aaa O0 00:00 0000 p0000",	   /* Mon Jan 01 23:59 2001 -0800 */
190 	""
191 };
192 
193 int
194 isdate(date)
195 	char date[];
196 {
197 	int i;
198 
199 	for(i = 0; *date_formats[i]; i++) {
200 		if (cmatch(date, date_formats[i]))
201 			return 1;
202 	}
203 	return 0;
204 }
205 
206 /*
207  * Match the given string (cp) against the given template (tp).
208  * Return 1 if they match, 0 if they don't
209  */
210 int
211 cmatch(cp, tp)
212 	char *cp, *tp;
213 {
214 
215 	while (*cp && *tp)
216 		switch (*tp++) {
217 		case 'a':
218 			if (!islower(*cp++))
219 				return(0);
220 			break;
221 		case 'A':
222 			if (!isupper(*cp++))
223 				return(0);
224 			break;
225 		case ' ':
226 			if (*cp++ != ' ')
227 				return(0);
228 			break;
229 		case '0':
230 			if (!isdigit(*cp++))
231 				return(0);
232 			break;
233 		case 'O':
234 			if (*cp != ' ' && !isdigit(*cp))
235 				return(0);
236 			cp++;
237 			break;
238 		case 'p':
239 			if (!ispunct(*cp++))
240 				return(0);
241 			break;
242 		case 'P':
243 			if (*cp != ' ' && !ispunct(*cp))
244 				return(0);
245 			cp++;
246 			break;
247 		case ':':
248 			if (*cp++ != ':')
249 				return(0);
250 			break;
251 		case 'N':
252 			if (*cp++ != '\n')
253 				return(0);
254 			break;
255 		}
256 	if (*cp || *tp)
257 		return(0);
258 	return(1);
259 }
260 
261 /*
262  * Collect a liberal (space, tab delimited) word into the word buffer
263  * passed.  Also, return a pointer to the next word following that,
264  * or NULL if none follow.
265  */
266 char *
267 nextword(wp, wbuf)
268 	char *wp, *wbuf;
269 {
270 	int c;
271 
272 	if (wp == NULL) {
273 		*wbuf = 0;
274 		return(NULL);
275 	}
276 	while ((c = *wp++) && c != ' ' && c != '\t') {
277 		*wbuf++ = c;
278 		if (c == '"') {
279  			while ((c = *wp++) && c != '"')
280  				*wbuf++ = c;
281  			if (c == '"')
282  				*wbuf++ = c;
283 			else
284 				wp--;
285  		}
286 	}
287 	*wbuf = '\0';
288 	for (; c == ' ' || c == '\t'; c = *wp++)
289 		;
290 	if (c == 0)
291 		return(NULL);
292 	return(wp - 1);
293 }
294