1 /*	$OpenBSD: head.c,v 1.5 1996/06/08 19:48:26 christos Exp $	*/
2 /*	$NetBSD: head.c,v 1.5 1996/06/08 19:48:26 christos 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 /*#include "def.h"*/
38 #include "head.h"
39 
40 /*
41  * Mail -- a mail program
42  *
43  * Routines for processing and detecting headlines.
44  */
45 
46 /*
47  * See if the passed line buffer is a mail header.
48  * Return true if yes.  Note the extreme pains to
49  * accomodate all funny formats.
50  */
ishead(char * linebuf)51 int ishead(char *linebuf)
52 {
53 	register char *cp;
54 	struct headline hl;
55 	char parbuf[BUFSIZ];
56 
57 	cp = linebuf;
58 	if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' ||
59 	    *cp++ != ' ')
60 		return (0);
61 	parse(linebuf, &hl, parbuf);
62 	if (hl.l_from == NOSTR || hl.l_date == NOSTR) {
63 		fail(linebuf, "No from or date field");
64 		return (0);
65 	}
66 	if (!isdate(hl.l_date)) {
67 		fail(linebuf, "Date field not legal date");
68 		return (0);
69 	}
70 	/*
71 	 * I guess we got it!
72 	 */
73 	return (1);
74 }
75 
76 /*ARGSUSED*/
fail(char * linebuf,char * reason)77 void fail(char *linebuf, char *reason)
78 {
79 
80 	/*
81 	if (value("debug") == NOSTR)
82 		return;
83 	fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
84 	*/
85 }
86 
87 /*
88  * Split a headline into its useful components.
89  * Copy the line into dynamic string space, then set
90  * pointers into the copied line in the passed headline
91  * structure.  Actually, it scans.
92  */
parse(char * line,register struct headline * hl,char * pbuf)93 void parse(char *line, register struct headline *hl, char *pbuf)
94 {
95 	register char *cp;
96 	char *sp;
97 	char word[LINESIZE];
98 
99 	hl->l_from = NOSTR;
100 	hl->l_tty = NOSTR;
101 	hl->l_date = NOSTR;
102 	cp = line;
103 	sp = pbuf;
104 	/*
105 	 * Skip over "From" first.
106 	 */
107 	cp = nextword(cp, word);
108 	cp = nextword(cp, word);
109 	if (*word)
110 		hl->l_from = copyin(word, &sp);
111 	if (cp != NOSTR && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
112 		cp = nextword(cp, word);
113 		hl->l_tty = copyin(word, &sp);
114 	}
115 	if (cp != NOSTR)
116 		hl->l_date = copyin(cp, &sp);
117 }
118 
119 /*
120  * Copy the string on the left into the string on the right
121  * and bump the right (reference) string pointer by the length.
122  * Thus, dynamically allocate space in the right string, copying
123  * the left string into it.
124  */
copyin(register char * src,char ** space)125 char * copyin(register char *src, char **space)
126 {
127 	register char *cp;
128 	char *top;
129 
130 	top = cp = *space;
131 	while ((*cp++ = *src++) != '\0')
132 		;
133 	*space = cp;
134 	return (top);
135 }
136 
137 /*
138  * Test to see if the passed string is a ctime(3) generated
139  * date string as documented in the manual.  The template
140  * below is used as the criterion of correctness.
141  * Also, we check for a possible trailing time zone using
142  * the tmztype template.
143  */
144 
145 /*
146  * 'A'	An upper case char
147  * 'a'	A lower case char
148  * ' '	A space
149  * '0'	A digit
150  * 'O'	An optional digit or space
151  * ':'	A colon
152  * 'N'	A new line
153  */
154 char ctype[] = "Aaa Aaa O0 00:00:00 0000";
155 char ctype_without_secs[] = "Aaa Aaa O0 00:00 0000";
156 char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000";
157 char tmztype_without_secs[] = "Aaa Aaa O0 00:00 AAA 0000";
158 
isdate(char * date)159 int isdate(char *date)
160 {
161 	return cmatch(date, ctype_without_secs) ||
162 	       cmatch(date, tmztype_without_secs) ||
163 	       cmatch(date, ctype) || cmatch(date, tmztype);
164 }
165 
166 /*
167  * Match the given string (cp) against the given template (tp).
168  * Return 1 if they match, 0 if they don't
169  */
cmatch(register char * cp,register char * tp)170 int cmatch(register char *cp, register char *tp)
171 {
172 
173 	while (*cp && *tp)
174 		switch (*tp++) {
175 		case 'a':
176 			if (!islower(*cp++))
177 				return 0;
178 			break;
179 		case 'A':
180 			if (!isupper(*cp++))
181 				return 0;
182 			break;
183 		case ' ':
184 			if (*cp++ != ' ')
185 				return 0;
186 			break;
187 		case '0':
188 			if (!isdigit(*cp++))
189 				return 0;
190 			break;
191 		case 'O':
192 			if (*cp != ' ' && !isdigit(*cp))
193 				return 0;
194 			cp++;
195 			break;
196 		case ':':
197 			if (*cp++ != ':')
198 				return 0;
199 			break;
200 		case 'N':
201 			if (*cp++ != '\n')
202 				return 0;
203 			break;
204 		}
205 	if (*cp || *tp)
206 		return 0;
207 	return (1);
208 }
209 
210 /*
211  * Collect a liberal (space, tab delimited) word into the word buffer
212  * passed.  Also, return a pointer to the next word following that,
213  * or NOSTR if none follow.
214  */
nextword(register char * wp,register char * wbuf)215 char *nextword(register char *wp, register char *wbuf)
216 {
217 	register char c;
218 
219 	if (wp == NOSTR) {
220 		*wbuf = 0;
221 		return (NOSTR);
222 	}
223 	while ((c = *wp++) && c != ' ' && c != '\t') {
224 		*wbuf++ = c;
225 		if (c == '"') {
226  			while ((c = *wp++) && c != '"')
227  				*wbuf++ = c;
228  			if (c == '"')
229  				*wbuf++ = c;
230 			else
231 				wp--;
232  		}
233 	}
234 	*wbuf = '\0';
235 	for (; c == ' ' || c == '\t'; c = *wp++)
236 		;
237 	if (c == 0)
238 		return (NOSTR);
239 	return (wp - 1);
240 }
241