1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 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/capsicum.h>
33 #include <sys/queue.h>
34 #include <sys/stat.h>
35 #include <sys/types.h>
36
37 #include <capsicum_helpers.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <signal.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46
47 struct entry {
48 int fd;
49 const char *name;
50 STAILQ_ENTRY(entry) entries;
51 };
52 static STAILQ_HEAD(, entry) head = STAILQ_HEAD_INITIALIZER(head);
53
54 static void add(int, const char *);
55 static void usage(void) __dead2;
56
57 int
main(int argc,char * argv[])58 main(int argc, char *argv[])
59 {
60 struct entry *p;
61 int n, fd, rval, wval;
62 char *bp;
63 int append, ch, exitval;
64 char *buf;
65 #define BSIZE (8 * 1024)
66
67 append = 0;
68 while ((ch = getopt(argc, argv, "ai")) != -1)
69 switch((char)ch) {
70 case 'a':
71 append = 1;
72 break;
73 case 'i':
74 (void)signal(SIGINT, SIG_IGN);
75 break;
76 case '?':
77 default:
78 usage();
79 }
80 argv += optind;
81 argc -= optind;
82
83 if ((buf = malloc(BSIZE)) == NULL)
84 err(1, "malloc");
85
86 if (caph_limit_stdin() == -1 || caph_limit_stderr() == -1)
87 err(EXIT_FAILURE, "unable to limit stdio");
88
89 add(STDOUT_FILENO, "stdout");
90
91 for (exitval = 0; *argv; ++argv)
92 if ((fd = open(*argv, append ? O_WRONLY|O_CREAT|O_APPEND :
93 O_WRONLY|O_CREAT|O_TRUNC, DEFFILEMODE)) < 0) {
94 warn("%s", *argv);
95 exitval = 1;
96 } else
97 add(fd, *argv);
98
99 if (caph_enter() < 0)
100 err(EXIT_FAILURE, "unable to enter capability mode");
101 while ((rval = read(STDIN_FILENO, buf, BSIZE)) > 0)
102 STAILQ_FOREACH(p, &head, entries) {
103 n = rval;
104 bp = buf;
105 do {
106 if ((wval = write(p->fd, bp, n)) == -1) {
107 warn("%s", p->name);
108 exitval = 1;
109 break;
110 }
111 bp += wval;
112 } while (n -= wval);
113 }
114 if (rval < 0)
115 err(1, "read");
116 exit(exitval);
117 }
118
119 static void
usage(void)120 usage(void)
121 {
122 (void)fprintf(stderr, "usage: tee [-ai] [file ...]\n");
123 exit(1);
124 }
125
126 static void
add(int fd,const char * name)127 add(int fd, const char *name)
128 {
129 struct entry *p;
130 cap_rights_t rights;
131
132 if (fd == STDOUT_FILENO) {
133 if (caph_limit_stdout() == -1)
134 err(EXIT_FAILURE, "unable to limit stdout");
135 } else {
136 cap_rights_init(&rights, CAP_WRITE, CAP_FSTAT);
137 if (caph_rights_limit(fd, &rights) < 0)
138 err(EXIT_FAILURE, "unable to limit rights");
139 }
140
141 if ((p = malloc(sizeof(struct entry))) == NULL)
142 err(1, "malloc");
143 p->fd = fd;
144 p->name = name;
145 STAILQ_INSERT_HEAD(&head, p, entries);
146 }
147