xref: /freebsd/usr.bin/tee/tee.c (revision 9f44a47fd07924afc035991af15d84e6585dea4f)
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  #ifndef lint
33  static const char copyright[] =
34  "@(#) Copyright (c) 1988, 1993\n\
35  	The Regents of the University of California.  All rights reserved.\n";
36  #endif /* not lint */
37  
38  #ifndef lint
39  #if 0
40  static char sccsid[] = "@(#)tee.c	8.1 (Berkeley) 6/6/93";
41  #endif
42  static const char rcsid[] =
43    "$FreeBSD$";
44  #endif /* not lint */
45  
46  #include <sys/capsicum.h>
47  #include <sys/queue.h>
48  #include <sys/stat.h>
49  #include <sys/types.h>
50  
51  #include <capsicum_helpers.h>
52  #include <err.h>
53  #include <errno.h>
54  #include <fcntl.h>
55  #include <signal.h>
56  #include <stdio.h>
57  #include <stdlib.h>
58  #include <string.h>
59  #include <unistd.h>
60  
61  struct entry {
62  	int fd;
63  	const char *name;
64  	STAILQ_ENTRY(entry) entries;
65  };
66  static STAILQ_HEAD(, entry) head = STAILQ_HEAD_INITIALIZER(head);
67  
68  static void add(int, const char *);
69  static void usage(void);
70  
71  int
72  main(int argc, char *argv[])
73  {
74  	struct entry *p;
75  	int n, fd, rval, wval;
76  	char *bp;
77  	int append, ch, exitval;
78  	char *buf;
79  #define	BSIZE (8 * 1024)
80  
81  	append = 0;
82  	while ((ch = getopt(argc, argv, "ai")) != -1)
83  		switch((char)ch) {
84  		case 'a':
85  			append = 1;
86  			break;
87  		case 'i':
88  			(void)signal(SIGINT, SIG_IGN);
89  			break;
90  		case '?':
91  		default:
92  			usage();
93  		}
94  	argv += optind;
95  	argc -= optind;
96  
97  	if ((buf = malloc(BSIZE)) == NULL)
98  		err(1, "malloc");
99  
100  	if (caph_limit_stdin() == -1 || caph_limit_stderr() == -1)
101  		err(EXIT_FAILURE, "unable to limit stdio");
102  
103  	add(STDOUT_FILENO, "stdout");
104  
105  	for (exitval = 0; *argv; ++argv)
106  		if ((fd = open(*argv, append ? O_WRONLY|O_CREAT|O_APPEND :
107  		    O_WRONLY|O_CREAT|O_TRUNC, DEFFILEMODE)) < 0) {
108  			warn("%s", *argv);
109  			exitval = 1;
110  		} else
111  			add(fd, *argv);
112  
113  	if (caph_enter() < 0)
114  		err(EXIT_FAILURE, "unable to enter capability mode");
115  	while ((rval = read(STDIN_FILENO, buf, BSIZE)) > 0)
116  		STAILQ_FOREACH(p, &head, entries) {
117  			n = rval;
118  			bp = buf;
119  			do {
120  				if ((wval = write(p->fd, bp, n)) == -1) {
121  					warn("%s", p->name);
122  					exitval = 1;
123  					break;
124  				}
125  				bp += wval;
126  			} while (n -= wval);
127  		}
128  	if (rval < 0)
129  		err(1, "read");
130  	exit(exitval);
131  }
132  
133  static void
134  usage(void)
135  {
136  	(void)fprintf(stderr, "usage: tee [-ai] [file ...]\n");
137  	exit(1);
138  }
139  
140  static void
141  add(int fd, const char *name)
142  {
143  	struct entry *p;
144  	cap_rights_t rights;
145  
146  	if (fd == STDOUT_FILENO) {
147  		if (caph_limit_stdout() == -1)
148  			err(EXIT_FAILURE, "unable to limit stdout");
149  	} else {
150  		cap_rights_init(&rights, CAP_WRITE, CAP_FSTAT);
151  		if (caph_rights_limit(fd, &rights) < 0)
152  			err(EXIT_FAILURE, "unable to limit rights");
153  	}
154  
155  	if ((p = malloc(sizeof(struct entry))) == NULL)
156  		err(1, "malloc");
157  	p->fd = fd;
158  	p->name = name;
159  	STAILQ_INSERT_HEAD(&head, p, entries);
160  }
161