xref: /freebsd/usr.bin/tee/tee.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*
2  * Copyright (c) 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1988, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif /* not lint */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)tee.c	8.1 (Berkeley) 6/6/93";
39 #endif
40 static const char rcsid[] =
41   "$FreeBSD$";
42 #endif /* not lint */
43 
44 #include <sys/capsicum.h>
45 #include <sys/stat.h>
46 #include <sys/types.h>
47 
48 #include <capsicum_helpers.h>
49 #include <err.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <signal.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 
58 typedef struct _list {
59 	struct _list *next;
60 	int fd;
61 	const char *name;
62 } LIST;
63 static LIST *head;
64 
65 static void add(int, const char *);
66 static void usage(void);
67 
68 int
69 main(int argc, char *argv[])
70 {
71 	LIST *p;
72 	int n, fd, rval, wval;
73 	char *bp;
74 	int append, ch, exitval;
75 	char *buf;
76 #define	BSIZE (8 * 1024)
77 
78 	append = 0;
79 	while ((ch = getopt(argc, argv, "ai")) != -1)
80 		switch((char)ch) {
81 		case 'a':
82 			append = 1;
83 			break;
84 		case 'i':
85 			(void)signal(SIGINT, SIG_IGN);
86 			break;
87 		case '?':
88 		default:
89 			usage();
90 		}
91 	argv += optind;
92 	argc -= optind;
93 
94 	if ((buf = malloc(BSIZE)) == NULL)
95 		err(1, "malloc");
96 
97 	if (caph_limit_stdin() == -1 || caph_limit_stderr() == -1)
98 		err(EXIT_FAILURE, "unable to limit stdio");
99 
100 	add(STDOUT_FILENO, "stdout");
101 
102 	for (exitval = 0; *argv; ++argv)
103 		if ((fd = open(*argv, append ? O_WRONLY|O_CREAT|O_APPEND :
104 		    O_WRONLY|O_CREAT|O_TRUNC, DEFFILEMODE)) < 0) {
105 			warn("%s", *argv);
106 			exitval = 1;
107 		} else
108 			add(fd, *argv);
109 
110 	if (cap_enter() < 0 && errno != ENOSYS)
111 		err(EXIT_FAILURE, "unable to enter capability mode");
112 	while ((rval = read(STDIN_FILENO, buf, BSIZE)) > 0)
113 		for (p = head; p; p = p->next) {
114 			n = rval;
115 			bp = buf;
116 			do {
117 				if ((wval = write(p->fd, bp, n)) == -1) {
118 					warn("%s", p->name);
119 					exitval = 1;
120 					break;
121 				}
122 				bp += wval;
123 			} while (n -= wval);
124 		}
125 	if (rval < 0)
126 		err(1, "read");
127 	exit(exitval);
128 }
129 
130 static void
131 usage(void)
132 {
133 	(void)fprintf(stderr, "usage: tee [-ai] [file ...]\n");
134 	exit(1);
135 }
136 
137 static void
138 add(int fd, const char *name)
139 {
140 	LIST *p;
141 	cap_rights_t rights;
142 
143 	if (fd == STDOUT_FILENO) {
144 		if (caph_limit_stdout() == -1)
145 			err(EXIT_FAILURE, "unable to limit stdout");
146 	} else {
147 		cap_rights_init(&rights, CAP_WRITE, CAP_FSTAT);
148 		if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS)
149 			err(EXIT_FAILURE, "unable to limit rights");
150 	}
151 
152 	if ((p = malloc(sizeof(LIST))) == NULL)
153 		err(1, "malloc");
154 	p->fd = fd;
155 	p->name = name;
156 	p->next = head;
157 	head = p;
158 }
159