xref: /openbsd/usr.bin/mail/head.c (revision cecf84d4)
1 /*	$OpenBSD: head.c,v 1.12 2014/01/17 18:42:30 okan 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. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "rcv.h"
34 #include "extern.h"
35 
36 /*
37  * Mail -- a mail program
38  *
39  * Routines for processing and detecting headlines.
40  */
41 
42 /*
43  * See if the passed line buffer is a mail header.
44  * Return true if yes.  Note the extreme pains to
45  * accommodate all funny formats.
46  */
47 int
48 ishead(char *linebuf)
49 {
50 	char *cp;
51 	struct headline hl;
52 	char parbuf[BUFSIZ];
53 
54 	cp = linebuf;
55 	if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' ||
56 	    *cp++ != ' ')
57 		return(0);
58 	parse(linebuf, &hl, parbuf);
59 	if (hl.l_from == NULL || hl.l_date == NULL) {
60 		fail(linebuf, "No from or date field");
61 		return(0);
62 	}
63 	if (!isdate(hl.l_date)) {
64 		fail(linebuf, "Date field not legal date");
65 		return(0);
66 	}
67 	/*
68 	 * I guess we got it!
69 	 */
70 	return(1);
71 }
72 
73 /*ARGSUSED*/
74 void
75 fail(char *linebuf, char *reason)
76 {
77 
78 	/*
79 	if (value("debug") == NULL)
80 		return;
81 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
82 	*/
83 }
84 
85 /*
86  * Split a headline into its useful components.
87  * Copy the line into dynamic string space, then set
88  * pointers into the copied line in the passed headline
89  * structure.  Actually, it scans.
90  */
91 void
92 parse(char *line, struct headline *hl, char *pbuf)
93 {
94 	char *cp, *sp;
95 	char word[LINESIZE];
96 
97 	hl->l_from = NULL;
98 	hl->l_tty = NULL;
99 	hl->l_date = NULL;
100 	cp = line;
101 	sp = pbuf;
102 	/*
103 	 * Skip over "From" first.
104 	 */
105 	cp = nextword(cp, word);
106 	cp = nextword(cp, word);
107 	if (*word)
108 		hl->l_from = copyin(word, &sp);
109 	if (cp != NULL && strncmp(cp, "tty", 3) == 0) {
110 		cp = nextword(cp, word);
111 		hl->l_tty = copyin(word, &sp);
112 	}
113 	if (cp != NULL)
114 		hl->l_date = copyin(cp, &sp);
115 }
116 
117 /*
118  * Copy the string on the left into the string on the right
119  * and bump the right (reference) string pointer by the length.
120  * Thus, dynamically allocate space in the right string, copying
121  * the left string into it.
122  */
123 char *
124 copyin(char *src, char **space)
125 {
126 	char *cp, *top;
127 
128 	top = cp = *space;
129 	while ((*cp++ = *src++) != '\0')
130 		;
131 	*space = cp;
132 	return(top);
133 }
134 
135 /*
136  * Test to see if the passed string is a ctime(3) generated
137  * date string as documented in the manual.  The template
138  * below is used as the criterion of correctness.
139  * Also, we check for a possible trailing time zone using
140  * the tmztype template.
141  */
142 
143 /*
144  * 'A'	An upper case char
145  * 'a'	A lower case char
146  * ' '	A space
147  * '0'	A digit
148  * 'O'	A digit or space
149  * 'p'	A punctuation char
150  * 'P'	A punctuation char or space
151  * ':'	A colon
152  * 'N'	A new line
153  */
154 
155 /*
156  * Yuck.  If the mail file is created by Sys V (Solaris),
157  * there are no seconds in the time...
158  */
159 
160 /*
161  * If the mail is created by another program such as imapd, it might
162  * have timezone as <-|+>nnnn (-0800 for instance) at the end.
163  */
164 
165 static char *date_formats[] = {
166 	"Aaa Aaa O0 00:00:00 0000",	   /* Mon Jan 01 23:59:59 2001 */
167 	"Aaa Aaa O0 00:00:00 AAA 0000",	   /* Mon Jan 01 23:59:59 PST 2001 */
168 	"Aaa Aaa O0 00:00:00 0000 p0000",  /* Mon Jan 01 23:59:59 2001 -0800 */
169 	"Aaa Aaa O0 00:00 0000",	   /* Mon Jan 01 23:59 2001 */
170 	"Aaa Aaa O0 00:00 AAA 0000",	   /* Mon Jan 01 23:59 PST 2001 */
171 	"Aaa Aaa O0 00:00 0000 p0000",	   /* Mon Jan 01 23:59 2001 -0800 */
172 	""
173 };
174 
175 int
176 isdate(char *date)
177 {
178 	int i;
179 
180 	for(i = 0; *date_formats[i]; i++) {
181 		if (cmatch(date, date_formats[i]))
182 			return 1;
183 	}
184 	return 0;
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(char *cp, char *tp)
193 {
194 
195 	while (*cp && *tp)
196 		switch (*tp++) {
197 		case 'a':
198 			if (!islower((unsigned char)*cp++))
199 				return(0);
200 			break;
201 		case 'A':
202 			if (!isupper((unsigned char)*cp++))
203 				return(0);
204 			break;
205 		case ' ':
206 			if (*cp++ != ' ')
207 				return(0);
208 			break;
209 		case '0':
210 			if (!isdigit((unsigned char)*cp++))
211 				return(0);
212 			break;
213 		case 'O':
214 			if (*cp != ' ' && !isdigit((unsigned char)*cp))
215 				return(0);
216 			cp++;
217 			break;
218 		case 'p':
219 			if (!ispunct((unsigned char)*cp++))
220 				return(0);
221 			break;
222 		case 'P':
223 			if (*cp != ' ' && !ispunct((unsigned char)*cp))
224 				return(0);
225 			cp++;
226 			break;
227 		case ':':
228 			if (*cp++ != ':')
229 				return(0);
230 			break;
231 		case 'N':
232 			if (*cp++ != '\n')
233 				return(0);
234 			break;
235 		}
236 	if (*cp || *tp)
237 		return(0);
238 	return(1);
239 }
240 
241 /*
242  * Collect a liberal (space, tab delimited) word into the word buffer
243  * passed.  Also, return a pointer to the next word following that,
244  * or NULL if none follow.
245  */
246 char *
247 nextword(char *wp, char *wbuf)
248 {
249 	int c;
250 
251 	if (wp == NULL) {
252 		*wbuf = 0;
253 		return(NULL);
254 	}
255 	while ((c = (unsigned char)*wp++) && c != ' ' && c != '\t') {
256 		*wbuf++ = c;
257 		if (c == '"') {
258  			while ((c = (unsigned char)*wp++) && c != '"')
259  				*wbuf++ = c;
260  			if (c == '"')
261  				*wbuf++ = c;
262 			else
263 				wp--;
264  		}
265 	}
266 	*wbuf = '\0';
267 	for (; c == ' ' || c == '\t'; c = (unsigned char)*wp++)
268 		;
269 	if (c == 0)
270 		return(NULL);
271 	return(wp - 1);
272 }
273