1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1980, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)head.c 8.2 (Berkeley) 4/20/95";
35 #endif
36 #endif /* not lint */
37 #include <sys/cdefs.h>
38 #include "rcv.h"
39 #include "extern.h"
40
41 /*
42 * Mail -- a mail program
43 *
44 * Routines for processing and detecting headlines.
45 */
46
47 /*
48 * See if the passed line buffer is a mail header.
49 * Return true if yes. Note the extreme pains to
50 * accommodate all funny formats.
51 */
52 int
ishead(char linebuf[])53 ishead(char linebuf[])
54 {
55 struct headline hl;
56 char parbuf[BUFSIZ];
57
58 if (strncmp(linebuf, "From ", 5) != 0)
59 return (0);
60 parse(linebuf, &hl, parbuf);
61 if (hl.l_date == NULL) {
62 fail(linebuf, "No date field");
63 return (0);
64 }
65 if (!isdate(hl.l_date)) {
66 fail(linebuf, "Date field not legal date");
67 return (0);
68 }
69 /*
70 * I guess we got it!
71 */
72 return (1);
73 }
74
75 void
fail(const char * linebuf __unused,const char * reason __unused)76 fail(const char *linebuf __unused, const char *reason __unused)
77 {
78
79 /*
80 if (value("debug") == NULL)
81 return;
82 fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
83 */
84 }
85
86 /*
87 * Split a headline into its useful components.
88 * Copy the line into dynamic string space, then set
89 * pointers into the copied line in the passed headline
90 * structure. Actually, it scans.
91 */
92 void
parse(char line[],struct headline * hl,char pbuf[])93 parse(char line[], struct headline *hl, char pbuf[])
94 {
95 char *cp, *sp;
96 char word[LINESIZE];
97
98 hl->l_from = NULL;
99 hl->l_tty = NULL;
100 hl->l_date = NULL;
101 cp = line;
102 sp = pbuf;
103 /*
104 * Skip over "From" first.
105 */
106 cp = nextword(cp, word);
107 /*
108 * Check for missing return-path.
109 */
110 if (isdate(cp)) {
111 hl->l_date = copyin(cp, &sp);
112 return;
113 }
114 cp = nextword(cp, word);
115 if (strlen(word) > 0)
116 hl->l_from = copyin(word, &sp);
117 if (cp != NULL && strncmp(cp, "tty", 3) == 0) {
118 cp = nextword(cp, word);
119 hl->l_tty = copyin(word, &sp);
120 }
121 if (cp != NULL)
122 hl->l_date = copyin(cp, &sp);
123 }
124
125 /*
126 * Copy the string on the left into the string on the right
127 * and bump the right (reference) string pointer by the length.
128 * Thus, dynamically allocate space in the right string, copying
129 * the left string into it.
130 */
131 char *
copyin(char * src,char ** space)132 copyin(char *src, char **space)
133 {
134 char *cp, *top;
135
136 top = cp = *space;
137 while ((*cp++ = *src++) != '\0')
138 ;
139 *space = cp;
140 return (top);
141 }
142
143 /*
144 * Test to see if the passed string is a ctime(3) generated
145 * date string as documented in the manual. The template
146 * below is used as the criterion of correctness.
147 * Also, we check for a possible trailing time zone using
148 * the tmztype template.
149 *
150 * If the mail file is created by Sys V (Solaris), there are
151 * no seconds in the time. If the mail is created by another
152 * program such as imapd, it might have timezone as
153 * <-|+>nnnn (-0800 for instance) at the end.
154 */
155
156 /*
157 * 'A' An upper case char
158 * 'a' A lower case char
159 * ' ' A space
160 * '0' A digit
161 * 'O' A digit or space
162 * 'p' A punctuation char
163 * 'P' A punctuation char or space
164 * ':' A colon
165 * 'N' A new line
166 */
167
168 static char *date_formats[] = {
169 "Aaa Aaa O0 00:00:00 0000", /* Mon Jan 01 23:59:59 2001 */
170 "Aaa Aaa O0 00:00:00 AAA 0000", /* Mon Jan 01 23:59:59 PST 2001 */
171 "Aaa Aaa O0 00:00:00 0000 p0000", /* Mon Jan 01 23:59:59 2001 -0800 */
172 "Aaa Aaa O0 00:00 0000", /* Mon Jan 01 23:59 2001 */
173 "Aaa Aaa O0 00:00 AAA 0000", /* Mon Jan 01 23:59 PST 2001 */
174 "Aaa Aaa O0 00:00 0000 p0000", /* Mon Jan 01 23:59 2001 -0800 */
175 NULL
176 };
177
178 int
isdate(char date[])179 isdate(char date[])
180 {
181 int i;
182
183 for(i = 0; date_formats[i] != NULL; i++) {
184 if (cmatch(date, date_formats[i]))
185 return (1);
186 }
187 return (0);
188 }
189
190 /*
191 * Match the given string (cp) against the given template (tp).
192 * Return 1 if they match, 0 if they don't
193 */
194 int
cmatch(char * cp,char * tp)195 cmatch(char *cp, char *tp)
196 {
197
198 while (*cp != '\0' && *tp != '\0')
199 switch (*tp++) {
200 case 'a':
201 if (!islower((unsigned char)*cp++))
202 return (0);
203 break;
204 case 'A':
205 if (!isupper((unsigned char)*cp++))
206 return (0);
207 break;
208 case ' ':
209 if (*cp++ != ' ')
210 return (0);
211 break;
212 case '0':
213 if (!isdigit((unsigned char)*cp++))
214 return (0);
215 break;
216 case 'O':
217 if (*cp != ' ' && !isdigit((unsigned char)*cp))
218 return (0);
219 cp++;
220 break;
221 case 'p':
222 if (!ispunct((unsigned char)*cp++))
223 return (0);
224 break;
225 case 'P':
226 if (*cp != ' ' && !ispunct((unsigned char)*cp))
227 return (0);
228 cp++;
229 break;
230 case ':':
231 if (*cp++ != ':')
232 return (0);
233 break;
234 case 'N':
235 if (*cp++ != '\n')
236 return (0);
237 break;
238 }
239 if (*cp != '\0' || *tp != '\0')
240 return (0);
241 return (1);
242 }
243
244 /*
245 * Collect a liberal (space, tab delimited) word into the word buffer
246 * passed. Also, return a pointer to the next word following that,
247 * or NULL if none follow.
248 */
249 char *
nextword(char * wp,char * wbuf)250 nextword(char *wp, char *wbuf)
251 {
252 int c;
253
254 if (wp == NULL) {
255 *wbuf = '\0';
256 return (NULL);
257 }
258 while ((c = *wp++) != '\0' && c != ' ' && c != '\t') {
259 *wbuf++ = c;
260 if (c == '"') {
261 while ((c = *wp++) != '\0' && c != '"')
262 *wbuf++ = c;
263 if (c == '"')
264 *wbuf++ = c;
265 else
266 wp--;
267 }
268 }
269 *wbuf = '\0';
270 for (; c == ' ' || c == '\t'; c = *wp++)
271 ;
272 if (c == '\0')
273 return (NULL);
274 return (wp - 1);
275 }
276