xref: /freebsd/usr.bin/mail/head.c (revision 6990ffd8a95caaba6858ad44ff1b3157d1efba8f)
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 
34 #ifndef lint
35 #if 0
36 static char sccsid[] = "@(#)head.c	8.1 (Berkeley) 6/6/93";
37 #endif
38 static const char rcsid[] =
39   "$FreeBSD$";
40 #endif /* not lint */
41 
42 #include "rcv.h"
43 #include "extern.h"
44 
45 /*
46  * Mail -- a mail program
47  *
48  * Routines for processing and detecting headlines.
49  */
50 
51 /*
52  * See if the passed line buffer is a mail header.
53  * Return true if yes.  Note the extreme pains to
54  * accomodate all funny formats.
55  */
56 int
57 ishead(linebuf)
58 	char linebuf[];
59 {
60 	struct headline hl;
61 	char parbuf[BUFSIZ];
62 
63 	if (strncmp(linebuf, "From ", 5))
64 		return (0);
65 	parse(linebuf, &hl, parbuf);
66 	if (hl.l_from == NULL || hl.l_date == NULL) {
67 		fail(linebuf, "No from or date field");
68 		return (0);
69 	}
70 	if (!isdate(hl.l_date)) {
71 		fail(linebuf, "Date field not legal date");
72 		return (0);
73 	}
74 	/*
75 	 * I guess we got it!
76 	 */
77 	return (1);
78 }
79 
80 /*ARGSUSED*/
81 void
82 fail(linebuf, reason)
83 	const char *linebuf, *reason;
84 {
85 
86 	/*
87 	if (value("debug") == NULL)
88 		return;
89 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
90 	*/
91 }
92 
93 /*
94  * Split a headline into its useful components.
95  * Copy the line into dynamic string space, then set
96  * pointers into the copied line in the passed headline
97  * structure.  Actually, it scans.
98  */
99 void
100 parse(line, hl, pbuf)
101 	char line[], pbuf[];
102 	struct headline *hl;
103 {
104 	char *cp, *sp;
105 	char word[LINESIZE];
106 
107 	hl->l_from = NULL;
108 	hl->l_tty = NULL;
109 	hl->l_date = NULL;
110 	cp = line;
111 	sp = pbuf;
112 	/*
113 	 * Skip over "From" first.
114 	 */
115 	cp = nextword(cp, word);
116 	cp = nextword(cp, word);
117 	if (*word != '\0')
118 		hl->l_from = copyin(word, &sp);
119 	if (cp != NULL && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
120 		cp = nextword(cp, word);
121 		hl->l_tty = copyin(word, &sp);
122 	}
123 	if (cp != NULL)
124 		hl->l_date = copyin(cp, &sp);
125 }
126 
127 /*
128  * Copy the string on the left into the string on the right
129  * and bump the right (reference) string pointer by the length.
130  * Thus, dynamically allocate space in the right string, copying
131  * the left string into it.
132  */
133 char *
134 copyin(src, space)
135 	char *src;
136 	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  * If the mail file is created by Sys V (Solaris), there are
155  * no seconds in the time. If the mail is created by another
156  * program such as imapd, it might have timezone as
157  * <-|+>nnnn (-0800 for instance) at the end.
158  */
159 
160 /*
161  * 'A'	An upper case char
162  * 'a'	A lower case char
163  * ' '	A space
164  * '0'	A digit
165  * 'O'	A digit or space
166  * 'p'	A punctuation char
167  * 'P'	A punctuation char or space
168  * ':'	A colon
169  * 'N'	A new line
170  */
171 
172 static char *date_formats[] = {
173 	"Aaa Aaa O0 00:00:00 0000",	   /* Mon Jan 01 23:59:59 2001 */
174 	"Aaa Aaa O0 00:00:00 AAA 0000",	   /* Mon Jan 01 23:59:59 PST 2001 */
175 	"Aaa Aaa O0 00:00:00 0000 p0000",  /* Mon Jan 01 23:59:59 2001 -0800 */
176 	"Aaa Aaa O0 00:00 0000",	   /* Mon Jan 01 23:59 2001 */
177 	"Aaa Aaa O0 00:00 AAA 0000",	   /* Mon Jan 01 23:59 PST 2001 */
178 	"Aaa Aaa O0 00:00 0000 p0000",	   /* Mon Jan 01 23:59 2001 -0800 */
179 	NULL
180 };
181 
182 int
183 isdate(date)
184 	char date[];
185 {
186 	int i;
187 
188 	for(i = 0; date_formats[i] != NULL; i++) {
189 		if (cmatch(date, date_formats[i]))
190 			return (1);
191 	}
192 	return (0);
193 }
194 
195 /*
196  * Match the given string (cp) against the given template (tp).
197  * Return 1 if they match, 0 if they don't
198  */
199 int
200 cmatch(cp, tp)
201 	char *cp, *tp;
202 {
203 
204 	while (*cp != '\0' && *tp != '\0')
205 		switch (*tp++) {
206 		case 'a':
207 			if (!islower(*cp++))
208 				return (0);
209 			break;
210 		case 'A':
211 			if (!isupper(*cp++))
212 				return (0);
213 			break;
214 		case ' ':
215 			if (*cp++ != ' ')
216 				return (0);
217 			break;
218 		case '0':
219 			if (!isdigit(*cp++))
220 				return (0);
221 			break;
222 		case 'O':
223 			if (*cp != ' ' && !isdigit(*cp))
224 				return (0);
225 			cp++;
226 			break;
227 		case 'p':
228 			if (!ispunct(*cp++))
229 				return (0);
230 			break;
231 		case 'P':
232 			if (*cp != ' ' && !ispunct(*cp))
233 				return (0);
234 			cp++;
235 			break;
236 		case ':':
237 			if (*cp++ != ':')
238 				return (0);
239 			break;
240 		case 'N':
241 			if (*cp++ != '\n')
242 				return (0);
243 			break;
244 		}
245 	if (*cp != '\0' || *tp != '\0')
246 		return (0);
247 	return (1);
248 }
249 
250 /*
251  * Collect a liberal (space, tab delimited) word into the word buffer
252  * passed.  Also, return a pointer to the next word following that,
253  * or NULL if none follow.
254  */
255 char *
256 nextword(wp, wbuf)
257 	char *wp, *wbuf;
258 {
259 	int c;
260 
261 	if (wp == NULL) {
262 		*wbuf = '\0';
263 		return (NULL);
264 	}
265 	while ((c = *wp++) != '\0' && c != ' ' && c != '\t') {
266 		*wbuf++ = c;
267 		if (c == '"') {
268  			while ((c = *wp++) != '\0' && c != '"')
269  				*wbuf++ = c;
270  			if (c == '"')
271  				*wbuf++ = c;
272 			else
273 				wp--;
274  		}
275 	}
276 	*wbuf = '\0';
277 	for (; c == ' ' || c == '\t'; c = *wp++)
278 		;
279 	if (c == '\0')
280 		return (NULL);
281 	return (wp - 1);
282 }
283