xref: /openbsd-src/usr.bin/mail/head.c (revision 62a742911104f98b9185b2c6b6007d9b1c36396c)
1 /*	$OpenBSD: head.c,v 1.5 1997/11/14 00:23:48 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 1.5 1997/11/14 00:23:48 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'	An optional digit or space
167  * ':'	A colon
168  * 'N'	A new line
169  */
170 char ctype[] = "Aaa Aaa O0 00:00:00 0000";
171 char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000";
172 /*
173  * Yuck.  If the mail file is created by Sys V (Solaris),
174  * there are no seconds in the time...
175  */
176 char SysV_ctype[] = "Aaa Aaa O0 00:00 0000";
177 char SysV_tmztype[] = "Aaa Aaa O0 00:00 AAA 0000";
178 
179 int
180 isdate(date)
181 	char date[];
182 {
183 
184 	return(cmatch(date, ctype) || cmatch(date, tmztype)
185 	    || cmatch(date, SysV_tmztype) || cmatch(date, SysV_ctype));
186 }
187 
188 /*
189  * Match the given string (cp) against the given template (tp).
190  * Return 1 if they match, 0 if they don't
191  */
192 int
193 cmatch(cp, tp)
194 	char *cp, *tp;
195 {
196 
197 	while (*cp && *tp)
198 		switch (*tp++) {
199 		case 'a':
200 			if (!islower(*cp++))
201 				return(0);
202 			break;
203 		case 'A':
204 			if (!isupper(*cp++))
205 				return(0);
206 			break;
207 		case ' ':
208 			if (*cp++ != ' ')
209 				return(0);
210 			break;
211 		case '0':
212 			if (!isdigit(*cp++))
213 				return(0);
214 			break;
215 		case 'O':
216 			if (*cp != ' ' && !isdigit(*cp))
217 				return(0);
218 			cp++;
219 			break;
220 		case ':':
221 			if (*cp++ != ':')
222 				return(0);
223 			break;
224 		case 'N':
225 			if (*cp++ != '\n')
226 				return(0);
227 			break;
228 		}
229 	if (*cp || *tp)
230 		return(0);
231 	return(1);
232 }
233 
234 /*
235  * Collect a liberal (space, tab delimited) word into the word buffer
236  * passed.  Also, return a pointer to the next word following that,
237  * or NULL if none follow.
238  */
239 char *
240 nextword(wp, wbuf)
241 	char *wp, *wbuf;
242 {
243 	int c;
244 
245 	if (wp == NULL) {
246 		*wbuf = 0;
247 		return(NULL);
248 	}
249 	while ((c = *wp++) && c != ' ' && c != '\t') {
250 		*wbuf++ = c;
251 		if (c == '"') {
252  			while ((c = *wp++) && c != '"')
253  				*wbuf++ = c;
254  			if (c == '"')
255  				*wbuf++ = c;
256 			else
257 				wp--;
258  		}
259 	}
260 	*wbuf = '\0';
261 	for (; c == ' ' || c == '\t'; c = *wp++)
262 		;
263 	if (c == 0)
264 		return(NULL);
265 	return(wp - 1);
266 }
267