xref: /openbsd-src/usr.bin/mail/head.c (revision 3a3fbb3f2e2521ab7c4a56b7ff7462ebd9095ec5)
1 /*	$OpenBSD: head.c,v 1.7 2001/11/21 15:26:39 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 const char sccsid[] = "@(#)head.c	8.2 (Berkeley) 4/20/95";
40 #else
41 static const char rcsid[] = "$OpenBSD: head.c,v 1.7 2001/11/21 15:26:39 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(char *linebuf)
61 {
62 	char *cp;
63 	struct headline hl;
64 	char parbuf[BUFSIZ];
65 
66 	cp = linebuf;
67 	if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' ||
68 	    *cp++ != ' ')
69 		return(0);
70 	parse(linebuf, &hl, parbuf);
71 	if (hl.l_from == NULL || hl.l_date == NULL) {
72 		fail(linebuf, "No from or date field");
73 		return(0);
74 	}
75 	if (!isdate(hl.l_date)) {
76 		fail(linebuf, "Date field not legal date");
77 		return(0);
78 	}
79 	/*
80 	 * I guess we got it!
81 	 */
82 	return(1);
83 }
84 
85 /*ARGSUSED*/
86 void
87 fail(char *linebuf, char *reason)
88 {
89 
90 	/*
91 	if (value("debug") == NULL)
92 		return;
93 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
94 	*/
95 }
96 
97 /*
98  * Split a headline into its useful components.
99  * Copy the line into dynamic string space, then set
100  * pointers into the copied line in the passed headline
101  * structure.  Actually, it scans.
102  */
103 void
104 parse(char *line, struct headline *hl, char *pbuf)
105 {
106 	char *cp, *sp;
107 	char word[LINESIZE];
108 
109 	hl->l_from = NULL;
110 	hl->l_tty = NULL;
111 	hl->l_date = NULL;
112 	cp = line;
113 	sp = pbuf;
114 	/*
115 	 * Skip over "From" first.
116 	 */
117 	cp = nextword(cp, word);
118 	cp = nextword(cp, word);
119 	if (*word)
120 		hl->l_from = copyin(word, &sp);
121 	if (cp != NULL && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
122 		cp = nextword(cp, word);
123 		hl->l_tty = copyin(word, &sp);
124 	}
125 	if (cp != NULL)
126 		hl->l_date = copyin(cp, &sp);
127 }
128 
129 /*
130  * Copy the string on the left into the string on the right
131  * and bump the right (reference) string pointer by the length.
132  * Thus, dynamically allocate space in the right string, copying
133  * the left string into it.
134  */
135 char *
136 copyin(char *src, char **space)
137 {
138 	char *cp, *top;
139 
140 	top = cp = *space;
141 	while ((*cp++ = *src++) != '\0')
142 		;
143 	*space = cp;
144 	return(top);
145 }
146 
147 /*
148  * Test to see if the passed string is a ctime(3) generated
149  * date string as documented in the manual.  The template
150  * below is used as the criterion of correctness.
151  * Also, we check for a possible trailing time zone using
152  * the tmztype template.
153  */
154 
155 /*
156  * 'A'	An upper case char
157  * 'a'	A lower case char
158  * ' '	A space
159  * '0'	A digit
160  * 'O'	A digit or space
161  * 'p'	A punctuation char
162  * 'P'	A punctuation char or space
163  * ':'	A colon
164  * 'N'	A new line
165  */
166 
167 /*
168  * Yuck.  If the mail file is created by Sys V (Solaris),
169  * there are no seconds in the time...
170  */
171 
172 /*
173  * If the mail is created by another program such as imapd, it might
174  * have timezone as <-|+>nnnn (-0800 for instance) at the end.
175  */
176 
177 static char *date_formats[] = {
178 	"Aaa Aaa O0 00:00:00 0000",	   /* Mon Jan 01 23:59:59 2001 */
179 	"Aaa Aaa O0 00:00:00 AAA 0000",	   /* Mon Jan 01 23:59:59 PST 2001 */
180 	"Aaa Aaa O0 00:00:00 0000 p0000",  /* Mon Jan 01 23:59:59 2001 -0800 */
181 	"Aaa Aaa O0 00:00 0000",	   /* Mon Jan 01 23:59 2001 */
182 	"Aaa Aaa O0 00:00 AAA 0000",	   /* Mon Jan 01 23:59 PST 2001 */
183 	"Aaa Aaa O0 00:00 0000 p0000",	   /* Mon Jan 01 23:59 2001 -0800 */
184 	""
185 };
186 
187 int
188 isdate(char *date)
189 {
190 	int i;
191 
192 	for(i = 0; *date_formats[i]; i++) {
193 		if (cmatch(date, date_formats[i]))
194 			return 1;
195 	}
196 	return 0;
197 }
198 
199 /*
200  * Match the given string (cp) against the given template (tp).
201  * Return 1 if they match, 0 if they don't
202  */
203 int
204 cmatch(char *cp, char *tp)
205 {
206 
207 	while (*cp && *tp)
208 		switch (*tp++) {
209 		case 'a':
210 			if (!islower(*cp++))
211 				return(0);
212 			break;
213 		case 'A':
214 			if (!isupper(*cp++))
215 				return(0);
216 			break;
217 		case ' ':
218 			if (*cp++ != ' ')
219 				return(0);
220 			break;
221 		case '0':
222 			if (!isdigit(*cp++))
223 				return(0);
224 			break;
225 		case 'O':
226 			if (*cp != ' ' && !isdigit(*cp))
227 				return(0);
228 			cp++;
229 			break;
230 		case 'p':
231 			if (!ispunct(*cp++))
232 				return(0);
233 			break;
234 		case 'P':
235 			if (*cp != ' ' && !ispunct(*cp))
236 				return(0);
237 			cp++;
238 			break;
239 		case ':':
240 			if (*cp++ != ':')
241 				return(0);
242 			break;
243 		case 'N':
244 			if (*cp++ != '\n')
245 				return(0);
246 			break;
247 		}
248 	if (*cp || *tp)
249 		return(0);
250 	return(1);
251 }
252 
253 /*
254  * Collect a liberal (space, tab delimited) word into the word buffer
255  * passed.  Also, return a pointer to the next word following that,
256  * or NULL if none follow.
257  */
258 char *
259 nextword(char *wp, char *wbuf)
260 {
261 	int c;
262 
263 	if (wp == NULL) {
264 		*wbuf = 0;
265 		return(NULL);
266 	}
267 	while ((c = *wp++) && c != ' ' && c != '\t') {
268 		*wbuf++ = c;
269 		if (c == '"') {
270  			while ((c = *wp++) && c != '"')
271  				*wbuf++ = c;
272  			if (c == '"')
273  				*wbuf++ = c;
274 			else
275 				wp--;
276  		}
277 	}
278 	*wbuf = '\0';
279 	for (; c == ' ' || c == '\t'; c = *wp++)
280 		;
281 	if (c == 0)
282 		return(NULL);
283 	return(wp - 1);
284 }
285