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 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 120 usage(void) 121 { 122 (void)fprintf(stderr, "usage: tee [-ai] [file ...]\n"); 123 exit(1); 124 } 125 126 static void 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