xref: /freebsd/usr.bin/mail/head.c (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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	8.2 (Berkeley) 4/20/95";
37 #endif
38 #endif /* not lint */
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
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) != 0)
64 		return (0);
65 	parse(linebuf, &hl, parbuf);
66 	if (hl.l_date == NULL) {
67 		fail(linebuf, "No 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 	/*
117 	 * Check for missing return-path.
118 	 */
119 	if (isdate(cp)) {
120 		hl->l_date = copyin(cp, &sp);
121 		return;
122 	}
123 	cp = nextword(cp, word);
124 	if (strlen(word) > 0)
125 		hl->l_from = copyin(word, &sp);
126 	if (cp != NULL && strncmp(cp, "tty", 3) == 0) {
127 		cp = nextword(cp, word);
128 		hl->l_tty = copyin(word, &sp);
129 	}
130 	if (cp != NULL)
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, *top;
146 
147 	top = cp = *space;
148 	while ((*cp++ = *src++) != '\0')
149 		;
150 	*space = cp;
151 	return (top);
152 }
153 
154 /*
155  * Test to see if the passed string is a ctime(3) generated
156  * date string as documented in the manual.  The template
157  * below is used as the criterion of correctness.
158  * Also, we check for a possible trailing time zone using
159  * the tmztype template.
160  *
161  * If the mail file is created by Sys V (Solaris), there are
162  * no seconds in the time. If the mail is created by another
163  * program such as imapd, it might have timezone as
164  * <-|+>nnnn (-0800 for instance) at the end.
165  */
166 
167 /*
168  * 'A'	An upper case char
169  * 'a'	A lower case char
170  * ' '	A space
171  * '0'	A digit
172  * 'O'	A digit or space
173  * 'p'	A punctuation char
174  * 'P'	A punctuation char or space
175  * ':'	A colon
176  * 'N'	A new line
177  */
178 
179 static char *date_formats[] = {
180 	"Aaa Aaa O0 00:00:00 0000",	   /* Mon Jan 01 23:59:59 2001 */
181 	"Aaa Aaa O0 00:00:00 AAA 0000",	   /* Mon Jan 01 23:59:59 PST 2001 */
182 	"Aaa Aaa O0 00:00:00 0000 p0000",  /* Mon Jan 01 23:59:59 2001 -0800 */
183 	"Aaa Aaa O0 00:00 0000",	   /* Mon Jan 01 23:59 2001 */
184 	"Aaa Aaa O0 00:00 AAA 0000",	   /* Mon Jan 01 23:59 PST 2001 */
185 	"Aaa Aaa O0 00:00 0000 p0000",	   /* Mon Jan 01 23:59 2001 -0800 */
186 	NULL
187 };
188 
189 int
190 isdate(date)
191 	char date[];
192 {
193 	int i;
194 
195 	for(i = 0; date_formats[i] != NULL; i++) {
196 		if (cmatch(date, date_formats[i]))
197 			return (1);
198 	}
199 	return (0);
200 }
201 
202 /*
203  * Match the given string (cp) against the given template (tp).
204  * Return 1 if they match, 0 if they don't
205  */
206 int
207 cmatch(cp, tp)
208 	char *cp, *tp;
209 {
210 
211 	while (*cp != '\0' && *tp != '\0')
212 		switch (*tp++) {
213 		case 'a':
214 			if (!islower((unsigned char)*cp++))
215 				return (0);
216 			break;
217 		case 'A':
218 			if (!isupper((unsigned char)*cp++))
219 				return (0);
220 			break;
221 		case ' ':
222 			if (*cp++ != ' ')
223 				return (0);
224 			break;
225 		case '0':
226 			if (!isdigit((unsigned char)*cp++))
227 				return (0);
228 			break;
229 		case 'O':
230 			if (*cp != ' ' && !isdigit((unsigned char)*cp))
231 				return (0);
232 			cp++;
233 			break;
234 		case 'p':
235 			if (!ispunct((unsigned char)*cp++))
236 				return (0);
237 			break;
238 		case 'P':
239 			if (*cp != ' ' && !ispunct((unsigned char)*cp))
240 				return (0);
241 			cp++;
242 			break;
243 		case ':':
244 			if (*cp++ != ':')
245 				return (0);
246 			break;
247 		case 'N':
248 			if (*cp++ != '\n')
249 				return (0);
250 			break;
251 		}
252 	if (*cp != '\0' || *tp != '\0')
253 		return (0);
254 	return (1);
255 }
256 
257 /*
258  * Collect a liberal (space, tab delimited) word into the word buffer
259  * passed.  Also, return a pointer to the next word following that,
260  * or NULL if none follow.
261  */
262 char *
263 nextword(wp, wbuf)
264 	char *wp, *wbuf;
265 {
266 	int c;
267 
268 	if (wp == NULL) {
269 		*wbuf = '\0';
270 		return (NULL);
271 	}
272 	while ((c = *wp++) != '\0' && c != ' ' && c != '\t') {
273 		*wbuf++ = c;
274 		if (c == '"') {
275  			while ((c = *wp++) != '\0' && c != '"')
276  				*wbuf++ = c;
277  			if (c == '"')
278  				*wbuf++ = c;
279 			else
280 				wp--;
281  		}
282 	}
283 	*wbuf = '\0';
284 	for (; c == ' ' || c == '\t'; c = *wp++)
285 		;
286 	if (c == '\0')
287 		return (NULL);
288 	return (wp - 1);
289 }
290