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 #if defined(LIBC_SCCS) && !defined(lint) 33 static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94"; 34 #endif /* LIBC_SCCS and not lint */ 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include "namespace.h" 39 #include <sys/types.h> 40 #include <sys/ioctl.h> 41 #include <sys/filio.h> 42 #include <fcntl.h> 43 #include <dirent.h> 44 #include <stdlib.h> 45 #include <termios.h> 46 #include <unistd.h> 47 #include <string.h> 48 #include <paths.h> 49 #include <errno.h> 50 #include "reentrant.h" 51 #include "un-namespace.h" 52 53 #include "libc_private.h" 54 55 static char ttyname_buf[sizeof(_PATH_DEV) + MAXNAMLEN]; 56 57 static once_t ttyname_init_once = ONCE_INITIALIZER; 58 static thread_key_t ttyname_key; 59 static int ttyname_keycreated = 0; 60 61 int 62 ttyname_r(int fd, char *buf, size_t len) 63 { 64 size_t used; 65 66 /* Don't write off the end of a zero-length buffer. */ 67 if (len < 1) 68 return (ERANGE); 69 70 *buf = '\0'; 71 72 /* Must be a terminal. */ 73 if (!isatty(fd)) 74 return (errno); 75 /* Must have enough room */ 76 if (len <= sizeof(_PATH_DEV)) 77 return (ERANGE); 78 79 strcpy(buf, _PATH_DEV); 80 used = strlen(buf); 81 if (fdevname_r(fd, buf + used, len - used) == NULL) 82 return (errno == EINVAL ? ERANGE : errno); 83 return (0); 84 } 85 86 static void 87 ttyname_keycreate(void) 88 { 89 ttyname_keycreated = (thr_keycreate(&ttyname_key, free) == 0); 90 } 91 92 char * 93 ttyname(int fd) 94 { 95 char *buf; 96 97 if (thr_main() != 0) 98 buf = ttyname_buf; 99 else { 100 if (thr_once(&ttyname_init_once, ttyname_keycreate) != 0 || 101 !ttyname_keycreated) 102 return (NULL); 103 if ((buf = thr_getspecific(ttyname_key)) == NULL) { 104 if ((buf = malloc(sizeof ttyname_buf)) == NULL) 105 return (NULL); 106 if (thr_setspecific(ttyname_key, buf) != 0) { 107 free(buf); 108 return (NULL); 109 } 110 } 111 } 112 113 if (ttyname_r(fd, buf, sizeof ttyname_buf) != 0) 114 return (NULL); 115 return (buf); 116 } 117