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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94"; 36 #endif /* LIBC_SCCS and not lint */ 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "namespace.h" 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <fcntl.h> 44 #include <dirent.h> 45 #include <stdlib.h> 46 #include <termios.h> 47 #include <unistd.h> 48 #include <string.h> 49 #include <paths.h> 50 #include <pthread.h> 51 #include "un-namespace.h" 52 53 #include "libc_private.h" 54 55 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN]; 56 static char *ttyname_threaded(int fd); 57 static char *ttyname_unthreaded(int fd); 58 59 static pthread_mutex_t ttyname_lock = PTHREAD_MUTEX_INITIALIZER; 60 static pthread_key_t ttyname_key; 61 static int ttyname_init = 0; 62 63 char * 64 ttyname(int fd) 65 { 66 char *ret; 67 68 if (__isthreaded == 0) 69 ret = ttyname_unthreaded(fd); 70 else 71 ret = ttyname_threaded(fd); 72 return (ret); 73 } 74 75 char * 76 ttyname_r(int fd, char *buf, size_t len) 77 { 78 struct stat sb; 79 char *rval; 80 81 rval = NULL; 82 83 /* Must be a terminal. */ 84 if (!isatty(fd)) 85 return (rval); 86 /* Must be a character device. */ 87 if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 88 return (rval); 89 /* Must have enough room */ 90 if (len <= sizeof(_PATH_DEV)) 91 return (rval); 92 93 strcpy(buf, _PATH_DEV); 94 devname_r(sb.st_rdev, S_IFCHR, 95 buf + strlen(buf), sizeof(buf) - strlen(buf)); 96 return (buf); 97 } 98 99 static char * 100 ttyname_threaded(int fd) 101 { 102 char *buf; 103 104 if (ttyname_init == 0) { 105 _pthread_mutex_lock(&ttyname_lock); 106 if (ttyname_init == 0) { 107 if (_pthread_key_create(&ttyname_key, free)) { 108 _pthread_mutex_unlock(&ttyname_lock); 109 return (NULL); 110 } 111 ttyname_init = 1; 112 } 113 _pthread_mutex_unlock(&ttyname_lock); 114 } 115 116 /* Must have thread specific data field to put data */ 117 if ((buf = _pthread_getspecific(ttyname_key)) == NULL) { 118 if ((buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) { 119 if (_pthread_setspecific(ttyname_key, buf) != 0) { 120 free(buf); 121 return (NULL); 122 } 123 } else { 124 return (NULL); 125 } 126 } 127 return (ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN)); 128 } 129 130 static char * 131 ttyname_unthreaded(int fd) 132 { 133 struct stat sb; 134 struct termios ttyb; 135 136 /* Must be a terminal. */ 137 if (tcgetattr(fd, &ttyb) < 0) 138 return (NULL); 139 /* Must be a character device. */ 140 if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 141 return (NULL); 142 143 strcpy(buf, _PATH_DEV); 144 devname_r(sb.st_rdev, S_IFCHR, 145 buf + strlen(buf), sizeof(buf) - strlen(buf)); 146 return (buf); 147 } 148