1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1980, 1988, 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 #include <sys/types.h>
33
34 #include <capsicum_helpers.h>
35 #include <ctype.h>
36 #include <err.h>
37 #include <pwd.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <paths.h>
41 #include <string.h>
42 #include <unistd.h>
43
44 static int match(const char *, const char *);
45 static void usage(void) __dead2;
46
47 int
main(int argc,char ** argv)48 main(int argc, char **argv)
49 {
50 FILE *mbox;
51 struct passwd *pwd;
52 int ch, count, newline;
53 const char *file;
54 char *sender, *p;
55 #if MAXPATHLEN > BUFSIZ
56 char buf[MAXPATHLEN];
57 #else
58 char buf[BUFSIZ];
59 #endif
60
61 file = sender = NULL;
62 count = -1;
63 while ((ch = getopt(argc, argv, "cf:s:")) != -1)
64 switch (ch) {
65 case 'c':
66 count = 0;
67 break;
68 case 'f':
69 file = optarg;
70 break;
71 case 's':
72 sender = optarg;
73 for (p = sender; *p; ++p)
74 *p = tolower(*p);
75 break;
76 case '?':
77 default:
78 usage();
79 }
80 argc -= optind;
81 argv += optind;
82
83 if (file == NULL) {
84 if (argc) {
85 (void)snprintf(buf, sizeof(buf), "%s/%s", _PATH_MAILDIR, *argv);
86 file = buf;
87 } else {
88 if (!(file = getenv("MAIL"))) {
89 if (!(pwd = getpwuid(getuid())))
90 errx(1, "no password file entry for you");
91 file = pwd->pw_name;
92 (void)snprintf(buf, sizeof(buf),
93 "%s/%s", _PATH_MAILDIR, file);
94 file = buf;
95 }
96 }
97 }
98
99 /* read from stdin */
100 if (strcmp(file, "-") == 0) {
101 mbox = stdin;
102 }
103 else if ((mbox = fopen(file, "r")) == NULL) {
104 errx(EXIT_FAILURE, "can't read %s", file);
105 }
106 if (caph_limit_stdio() < 0 || caph_enter() < 0) {
107 err(EXIT_FAILURE, "capsicum");
108 }
109 for (newline = 1; fgets(buf, sizeof(buf), mbox);) {
110 if (*buf == '\n') {
111 newline = 1;
112 continue;
113 }
114 if (newline && !strncmp(buf, "From ", 5) &&
115 (!sender || match(buf + 5, sender))) {
116 if (count != -1)
117 count++;
118 else
119 printf("%s", buf);
120 }
121 newline = 0;
122 }
123 if (count != -1)
124 printf("There %s %d message%s in your incoming mailbox.\n",
125 count == 1 ? "is" : "are", count, count == 1 ? "" : "s");
126 fclose(mbox);
127 exit(EXIT_SUCCESS);
128 }
129
130 static void
usage(void)131 usage(void)
132 {
133 fprintf(stderr, "usage: from [-c] [-f file] [-s sender] [user]\n");
134 exit(EXIT_FAILURE);
135 }
136
137 static int
match(const char * line,const char * sender)138 match(const char *line, const char *sender)
139 {
140 char ch, pch, first;
141 const char *p, *t;
142
143 for (first = *sender++;;) {
144 if (isspace(ch = *line))
145 return (0);
146 ++line;
147 ch = tolower(ch);
148 if (ch != first)
149 continue;
150 for (p = sender, t = line;;) {
151 if (!(pch = *p++))
152 return (1);
153 ch = tolower(*t);
154 t++;
155 if (ch != pch)
156 break;
157 }
158 }
159 /* NOTREACHED */
160 }
161