xref: /netbsd-src/usr.bin/mail/head.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: head.c,v 1.7 1997/10/19 05:03:26 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1980, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)head.c	8.2 (Berkeley) 4/20/95";
40 #else
41 __RCSID("$NetBSD: head.c,v 1.7 1997/10/19 05:03:26 lukem 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 == NOSTR || hl.l_date == NOSTR) {
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") == NOSTR)
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;
111 	char *sp;
112 	char word[LINESIZE];
113 
114 	hl->l_from = NOSTR;
115 	hl->l_tty = NOSTR;
116 	hl->l_date = NOSTR;
117 	cp = line;
118 	sp = pbuf;
119 	/*
120 	 * Skip over "From" first.
121 	 */
122 	cp = nextword(cp, word);
123 	cp = nextword(cp, word);
124 	if (*word)
125 		hl->l_from = copyin(word, &sp);
126 	if (cp != NOSTR && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
127 		cp = nextword(cp, word);
128 		hl->l_tty = copyin(word, &sp);
129 	}
130 	if (cp != NOSTR)
131 		hl->l_date = copyin(cp, &sp);
132 }
133 
134 /*
135  * Copy the string on the left into the string on the right
136  * and bump the right (reference) string pointer by the length.
137  * Thus, dynamically allocate space in the right string, copying
138  * the left string into it.
139  */
140 char *
141 copyin(src, space)
142 	char *src;
143 	char **space;
144 {
145 	char *cp;
146 	char *top;
147 
148 	top = cp = *space;
149 	while ((*cp++ = *src++) != '\0')
150 		;
151 	*space = cp;
152 	return (top);
153 }
154 
155 /*
156  * Test to see if the passed string is a ctime(3) generated
157  * date string as documented in the manual.  The template
158  * below is used as the criterion of correctness.
159  * Also, we check for a possible trailing time zone using
160  * the tmztype template.
161  */
162 
163 /*
164  * 'A'	An upper case char
165  * 'a'	A lower case char
166  * ' '	A space
167  * '0'	A digit
168  * 'O'	An optional digit or space
169  * ':'	A colon
170  * 'N'	A new line
171  */
172 char ctype[] = "Aaa Aaa O0 00:00:00 0000";
173 char SysV_ctype[] = "Aaa Aaa O0 00:00 0000";
174 char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000";
175 char SysV_tmztype[] = "Aaa Aaa O0 00:00 AAA 0000";
176 
177 int
178 isdate(date)
179 	char date[];
180 {
181 
182 	return cmatch(date, ctype) ||
183 	       cmatch(date, tmztype) ||
184 	       cmatch(date, SysV_tmztype) || cmatch(date, SysV_ctype);
185 }
186 
187 /*
188  * Match the given string (cp) against the given template (tp).
189  * Return 1 if they match, 0 if they don't
190  */
191 int
192 cmatch(cp, tp)
193 	char *cp, *tp;
194 {
195 
196 	while (*cp && *tp)
197 		switch (*tp++) {
198 		case 'a':
199 			if (!islower(*cp++))
200 				return 0;
201 			break;
202 		case 'A':
203 			if (!isupper(*cp++))
204 				return 0;
205 			break;
206 		case ' ':
207 			if (*cp++ != ' ')
208 				return 0;
209 			break;
210 		case '0':
211 			if (!isdigit(*cp++))
212 				return 0;
213 			break;
214 		case 'O':
215 			if (*cp != ' ' && !isdigit(*cp))
216 				return 0;
217 			cp++;
218 			break;
219 		case ':':
220 			if (*cp++ != ':')
221 				return 0;
222 			break;
223 		case 'N':
224 			if (*cp++ != '\n')
225 				return 0;
226 			break;
227 		}
228 	if (*cp || *tp)
229 		return 0;
230 	return (1);
231 }
232 
233 /*
234  * Collect a liberal (space, tab delimited) word into the word buffer
235  * passed.  Also, return a pointer to the next word following that,
236  * or NOSTR if none follow.
237  */
238 char *
239 nextword(wp, wbuf)
240 	char *wp, *wbuf;
241 {
242 	int c;
243 
244 	if (wp == NOSTR) {
245 		*wbuf = 0;
246 		return (NOSTR);
247 	}
248 	while ((c = *wp++) && c != ' ' && c != '\t') {
249 		*wbuf++ = c;
250 		if (c == '"') {
251  			while ((c = *wp++) && c != '"')
252  				*wbuf++ = c;
253  			if (c == '"')
254  				*wbuf++ = c;
255 			else
256 				wp--;
257  		}
258 	}
259 	*wbuf = '\0';
260 	for (; c == ' ' || c == '\t'; c = *wp++)
261 		;
262 	if (c == 0)
263 		return (NOSTR);
264 	return (wp - 1);
265 }
266