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/cdefs.h> 33 __SCCSID("@(#)ttyname.c 8.2 (Berkeley) 1/27/94"); 34 #include "namespace.h" 35 #include <sys/types.h> 36 #include <sys/ioctl.h> 37 #include <sys/filio.h> 38 #include <fcntl.h> 39 #include <dirent.h> 40 #include <stdlib.h> 41 #include <termios.h> 42 #include <unistd.h> 43 #include <string.h> 44 #include <paths.h> 45 #include <errno.h> 46 #include "reentrant.h" 47 #include "un-namespace.h" 48 49 #include "libc_private.h" 50 51 static char ttyname_buf[sizeof(_PATH_DEV) + MAXNAMLEN]; 52 53 static once_t ttyname_init_once = ONCE_INITIALIZER; 54 static thread_key_t ttyname_key; 55 static int ttyname_keycreated = 0; 56 57 int 58 ttyname_r(int fd, char *buf, size_t len) 59 { 60 size_t used; 61 62 /* Don't write off the end of a zero-length buffer. */ 63 if (len < 1) 64 return (ERANGE); 65 66 *buf = '\0'; 67 68 /* Must be a terminal. */ 69 if (!isatty(fd)) 70 return (errno); 71 /* Must have enough room */ 72 if (len <= sizeof(_PATH_DEV)) 73 return (ERANGE); 74 75 strcpy(buf, _PATH_DEV); 76 used = strlen(buf); 77 if (fdevname_r(fd, buf + used, len - used) == NULL) 78 return (errno == EINVAL ? ERANGE : errno); 79 return (0); 80 } 81 82 static void 83 ttyname_keycreate(void) 84 { 85 ttyname_keycreated = (thr_keycreate(&ttyname_key, free) == 0); 86 } 87 88 char * 89 ttyname(int fd) 90 { 91 char *buf; 92 93 if (thr_main() != 0) 94 buf = ttyname_buf; 95 else { 96 if (thr_once(&ttyname_init_once, ttyname_keycreate) != 0 || 97 !ttyname_keycreated) 98 return (NULL); 99 if ((buf = thr_getspecific(ttyname_key)) == NULL) { 100 if ((buf = malloc(sizeof ttyname_buf)) == NULL) 101 return (NULL); 102 if (thr_setspecific(ttyname_key, buf) != 0) { 103 free(buf); 104 return (NULL); 105 } 106 } 107 } 108 109 if (ttyname_r(fd, buf, sizeof ttyname_buf) != 0) 110 return (NULL); 111 return (buf); 112 } 113