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 __FBSDID("$FreeBSD: stable/12/usr.bin/mail/head.c 326025 2017-11-20 19:49:47Z pfg $");
39
40 #include "rcv.h"
41 #include "extern.h"
42
43 /*
44 * Mail -- a mail program
45 *
46 * Routines for processing and detecting headlines.
47 */
48
49 /*
50 * See if the passed line buffer is a mail header.
51 * Return true if yes. Note the extreme pains to
52 * accommodate all funny formats.
53 */
54 int
ishead(char linebuf[])55 ishead(char linebuf[])
56 {
57 struct headline hl;
58 char parbuf[BUFSIZ];
59
60 if (strncmp(linebuf, "From ", 5) != 0)
61 return (0);
62 parse(linebuf, &hl, parbuf);
63 if (hl.l_date == NULL) {
64 fail(linebuf, "No date field");
65 return (0);
66 }
67 if (!isdate(hl.l_date)) {
68 fail(linebuf, "Date field not legal date");
69 return (0);
70 }
71 /*
72 * I guess we got it!
73 */
74 return (1);
75 }
76
77 void
fail(const char * linebuf __unused,const char * reason __unused)78 fail(const char *linebuf __unused, const char *reason __unused)
79 {
80
81 /*
82 if (value("debug") == NULL)
83 return;
84 fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
85 */
86 }
87
88 /*
89 * Split a headline into its useful components.
90 * Copy the line into dynamic string space, then set
91 * pointers into the copied line in the passed headline
92 * structure. Actually, it scans.
93 */
94 void
parse(char line[],struct headline * hl,char pbuf[])95 parse(char line[], struct headline *hl, char pbuf[])
96 {
97 char *cp, *sp;
98 char word[LINESIZE];
99
100 hl->l_from = NULL;
101 hl->l_tty = NULL;
102 hl->l_date = NULL;
103 cp = line;
104 sp = pbuf;
105 /*
106 * Skip over "From" first.
107 */
108 cp = nextword(cp, word);
109 /*
110 * Check for missing return-path.
111 */
112 if (isdate(cp)) {
113 hl->l_date = copyin(cp, &sp);
114 return;
115 }
116 cp = nextword(cp, word);
117 if (strlen(word) > 0)
118 hl->l_from = copyin(word, &sp);
119 if (cp != NULL && strncmp(cp, "tty", 3) == 0) {
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 *
copyin(char * src,char ** space)134 copyin(char *src, char **space)
135 {
136 char *cp, *top;
137
138 top = cp = *space;
139 while ((*cp++ = *src++) != '\0')
140 ;
141 *space = cp;
142 return (top);
143 }
144
145 /*
146 * Test to see if the passed string is a ctime(3) generated
147 * date string as documented in the manual. The template
148 * below is used as the criterion of correctness.
149 * Also, we check for a possible trailing time zone using
150 * the tmztype template.
151 *
152 * If the mail file is created by Sys V (Solaris), there are
153 * no seconds in the time. If the mail is created by another
154 * program such as imapd, it might have timezone as
155 * <-|+>nnnn (-0800 for instance) at the end.
156 */
157
158 /*
159 * 'A' An upper case char
160 * 'a' A lower case char
161 * ' ' A space
162 * '0' A digit
163 * 'O' A digit or space
164 * 'p' A punctuation char
165 * 'P' A punctuation char or space
166 * ':' A colon
167 * 'N' A new line
168 */
169
170 static char *date_formats[] = {
171 "Aaa Aaa O0 00:00:00 0000", /* Mon Jan 01 23:59:59 2001 */
172 "Aaa Aaa O0 00:00:00 AAA 0000", /* Mon Jan 01 23:59:59 PST 2001 */
173 "Aaa Aaa O0 00:00:00 0000 p0000", /* Mon Jan 01 23:59:59 2001 -0800 */
174 "Aaa Aaa O0 00:00 0000", /* Mon Jan 01 23:59 2001 */
175 "Aaa Aaa O0 00:00 AAA 0000", /* Mon Jan 01 23:59 PST 2001 */
176 "Aaa Aaa O0 00:00 0000 p0000", /* Mon Jan 01 23:59 2001 -0800 */
177 NULL
178 };
179
180 int
isdate(char date[])181 isdate(char date[])
182 {
183 int i;
184
185 for(i = 0; date_formats[i] != NULL; i++) {
186 if (cmatch(date, date_formats[i]))
187 return (1);
188 }
189 return (0);
190 }
191
192 /*
193 * Match the given string (cp) against the given template (tp).
194 * Return 1 if they match, 0 if they don't
195 */
196 int
cmatch(char * cp,char * tp)197 cmatch(char *cp, char *tp)
198 {
199
200 while (*cp != '\0' && *tp != '\0')
201 switch (*tp++) {
202 case 'a':
203 if (!islower((unsigned char)*cp++))
204 return (0);
205 break;
206 case 'A':
207 if (!isupper((unsigned char)*cp++))
208 return (0);
209 break;
210 case ' ':
211 if (*cp++ != ' ')
212 return (0);
213 break;
214 case '0':
215 if (!isdigit((unsigned char)*cp++))
216 return (0);
217 break;
218 case 'O':
219 if (*cp != ' ' && !isdigit((unsigned char)*cp))
220 return (0);
221 cp++;
222 break;
223 case 'p':
224 if (!ispunct((unsigned char)*cp++))
225 return (0);
226 break;
227 case 'P':
228 if (*cp != ' ' && !ispunct((unsigned char)*cp))
229 return (0);
230 cp++;
231 break;
232 case ':':
233 if (*cp++ != ':')
234 return (0);
235 break;
236 case 'N':
237 if (*cp++ != '\n')
238 return (0);
239 break;
240 }
241 if (*cp != '\0' || *tp != '\0')
242 return (0);
243 return (1);
244 }
245
246 /*
247 * Collect a liberal (space, tab delimited) word into the word buffer
248 * passed. Also, return a pointer to the next word following that,
249 * or NULL if none follow.
250 */
251 char *
nextword(char * wp,char * wbuf)252 nextword(char *wp, char *wbuf)
253 {
254 int c;
255
256 if (wp == NULL) {
257 *wbuf = '\0';
258 return (NULL);
259 }
260 while ((c = *wp++) != '\0' && c != ' ' && c != '\t') {
261 *wbuf++ = c;
262 if (c == '"') {
263 while ((c = *wp++) != '\0' && c != '"')
264 *wbuf++ = c;
265 if (c == '"')
266 *wbuf++ = c;
267 else
268 wp--;
269 }
270 }
271 *wbuf = '\0';
272 for (; c == ' ' || c == '\t'; c = *wp++)
273 ;
274 if (c == '\0')
275 return (NULL);
276 return (wp - 1);
277 }
278