xref: /dragonfly/usr.bin/mail/head.c (revision 1de703da)
1 /*
2  * Copyright (c) 1980, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#)head.c	8.2 (Berkeley) 4/20/95
34  * $FreeBSD: src/usr.bin/mail/head.c,v 1.1.1.1.14.4 2003/01/06 05:46:03 mikeh Exp $
35  * $DragonFly: src/usr.bin/mail/head.c,v 1.2 2003/06/17 04:29:28 dillon Exp $
36  */
37 
38 #include "rcv.h"
39 #include "extern.h"
40 
41 /*
42  * Mail -- a mail program
43  *
44  * Routines for processing and detecting headlines.
45  */
46 
47 /*
48  * See if the passed line buffer is a mail header.
49  * Return true if yes.  Note the extreme pains to
50  * accomodate all funny formats.
51  */
52 int
53 ishead(linebuf)
54 	char linebuf[];
55 {
56 	struct headline hl;
57 	char parbuf[BUFSIZ];
58 
59 	if (strncmp(linebuf, "From ", 5))
60 		return (0);
61 	parse(linebuf, &hl, parbuf);
62 	if (hl.l_from == NULL || hl.l_date == NULL) {
63 		fail(linebuf, "No from or date field");
64 		return (0);
65 	}
66 	if (!isdate(hl.l_date)) {
67 		fail(linebuf, "Date field not legal date");
68 		return (0);
69 	}
70 	/*
71 	 * I guess we got it!
72 	 */
73 	return (1);
74 }
75 
76 /*ARGSUSED*/
77 void
78 fail(linebuf, reason)
79 	const char *linebuf, *reason;
80 {
81 
82 	/*
83 	if (value("debug") == NULL)
84 		return;
85 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
86 	*/
87 }
88 
89 /*
90  * Split a headline into its useful components.
91  * Copy the line into dynamic string space, then set
92  * pointers into the copied line in the passed headline
93  * structure.  Actually, it scans.
94  */
95 void
96 parse(line, hl, pbuf)
97 	char line[], pbuf[];
98 	struct headline *hl;
99 {
100 	char *cp, *sp;
101 	char word[LINESIZE];
102 
103 	hl->l_from = NULL;
104 	hl->l_tty = NULL;
105 	hl->l_date = NULL;
106 	cp = line;
107 	sp = pbuf;
108 	/*
109 	 * Skip over "From" first.
110 	 */
111 	cp = nextword(cp, word);
112 	cp = nextword(cp, word);
113 	if (*word != '\0')
114 		hl->l_from = copyin(word, &sp);
115 	if (cp != NULL && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
116 		cp = nextword(cp, word);
117 		hl->l_tty = copyin(word, &sp);
118 	}
119 	if (cp != NULL)
120 		hl->l_date = copyin(cp, &sp);
121 }
122 
123 /*
124  * Copy the string on the left into the string on the right
125  * and bump the right (reference) string pointer by the length.
126  * Thus, dynamically allocate space in the right string, copying
127  * the left string into it.
128  */
129 char *
130 copyin(src, space)
131 	char *src;
132 	char **space;
133 {
134 	char *cp, *top;
135 
136 	top = cp = *space;
137 	while ((*cp++ = *src++) != '\0')
138 		;
139 	*space = cp;
140 	return (top);
141 }
142 
143 /*
144  * Test to see if the passed string is a ctime(3) generated
145  * date string as documented in the manual.  The template
146  * below is used as the criterion of correctness.
147  * Also, we check for a possible trailing time zone using
148  * the tmztype template.
149  *
150  * If the mail file is created by Sys V (Solaris), there are
151  * no seconds in the time. If the mail is created by another
152  * program such as imapd, it might have timezone as
153  * <-|+>nnnn (-0800 for instance) at the end.
154  */
155 
156 /*
157  * 'A'	An upper case char
158  * 'a'	A lower case char
159  * ' '	A space
160  * '0'	A digit
161  * 'O'	A digit or space
162  * 'p'	A punctuation char
163  * 'P'	A punctuation char or space
164  * ':'	A colon
165  * 'N'	A new line
166  */
167 
168 static char *date_formats[] = {
169 	"Aaa Aaa O0 00:00:00 0000",	   /* Mon Jan 01 23:59:59 2001 */
170 	"Aaa Aaa O0 00:00:00 AAA 0000",	   /* Mon Jan 01 23:59:59 PST 2001 */
171 	"Aaa Aaa O0 00:00:00 0000 p0000",  /* Mon Jan 01 23:59:59 2001 -0800 */
172 	"Aaa Aaa O0 00:00 0000",	   /* Mon Jan 01 23:59 2001 */
173 	"Aaa Aaa O0 00:00 AAA 0000",	   /* Mon Jan 01 23:59 PST 2001 */
174 	"Aaa Aaa O0 00:00 0000 p0000",	   /* Mon Jan 01 23:59 2001 -0800 */
175 	NULL
176 };
177 
178 int
179 isdate(date)
180 	char date[];
181 {
182 	int i;
183 
184 	for(i = 0; date_formats[i] != NULL; i++) {
185 		if (cmatch(date, date_formats[i]))
186 			return (1);
187 	}
188 	return (0);
189 }
190 
191 /*
192  * Match the given string (cp) against the given template (tp).
193  * Return 1 if they match, 0 if they don't
194  */
195 int
196 cmatch(cp, tp)
197 	char *cp, *tp;
198 {
199 
200 	while (*cp != '\0' && *tp != '\0')
201 		switch (*tp++) {
202 		case 'a':
203 			if (!islower((unsigned char)*cp++))
204 				return (0);
205 			break;
206 		case 'A':
207 			if (!isupper((unsigned char)*cp++))
208 				return (0);
209 			break;
210 		case ' ':
211 			if (*cp++ != ' ')
212 				return (0);
213 			break;
214 		case '0':
215 			if (!isdigit((unsigned char)*cp++))
216 				return (0);
217 			break;
218 		case 'O':
219 			if (*cp != ' ' && !isdigit((unsigned char)*cp))
220 				return (0);
221 			cp++;
222 			break;
223 		case 'p':
224 			if (!ispunct((unsigned char)*cp++))
225 				return (0);
226 			break;
227 		case 'P':
228 			if (*cp != ' ' && !ispunct((unsigned char)*cp))
229 				return (0);
230 			cp++;
231 			break;
232 		case ':':
233 			if (*cp++ != ':')
234 				return (0);
235 			break;
236 		case 'N':
237 			if (*cp++ != '\n')
238 				return (0);
239 			break;
240 		}
241 	if (*cp != '\0' || *tp != '\0')
242 		return (0);
243 	return (1);
244 }
245 
246 /*
247  * Collect a liberal (space, tab delimited) word into the word buffer
248  * passed.  Also, return a pointer to the next word following that,
249  * or NULL if none follow.
250  */
251 char *
252 nextword(wp, wbuf)
253 	char *wp, *wbuf;
254 {
255 	int c;
256 
257 	if (wp == NULL) {
258 		*wbuf = '\0';
259 		return (NULL);
260 	}
261 	while ((c = *wp++) != '\0' && c != ' ' && c != '\t') {
262 		*wbuf++ = c;
263 		if (c == '"') {
264  			while ((c = *wp++) != '\0' && c != '"')
265  				*wbuf++ = c;
266  			if (c == '"')
267  				*wbuf++ = c;
268 			else
269 				wp--;
270  		}
271 	}
272 	*wbuf = '\0';
273 	for (; c == ' ' || c == '\t'; c = *wp++)
274 		;
275 	if (c == '\0')
276 		return (NULL);
277 	return (wp - 1);
278 }
279