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 * $FreeBSD: src/lib/libc/gen/ttyname.c,v 1.10.6.2 2002/10/15 19:46:46 fjoe Exp $ 34 * $DragonFly: src/lib/libc/gen/ttyname.c,v 1.14 2005/11/19 22:32:53 swildner Exp $ 35 * 36 * @(#)ttyname.c 8.2 (Berkeley) 1/27/94 37 */ 38 39 #include "namespace.h" 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <fcntl.h> 43 #include <dirent.h> 44 #include <limits.h> 45 #include <stdlib.h> 46 #include <termios.h> 47 #include <unistd.h> 48 #include <string.h> 49 #include <paths.h> 50 51 #include <pthread.h> 52 #include "un-namespace.h" 53 54 #include <db.h> 55 #include "libc_private.h" 56 57 static char static_buf[TTY_PATH_MAX] = _PATH_DEV; 58 static char *oldttyname(int, struct stat *); 59 static char *ttyname_threaded(int fd); 60 static char *ttyname_unthreaded(int fd); 61 extern int __sys_fstat(int, struct stat *); 62 63 static pthread_mutex_t ttyname_lock = PTHREAD_MUTEX_INITIALIZER; 64 static pthread_key_t ttyname_key; 65 static int ttyname_init = 0; 66 67 char * 68 ttyname(int fd) 69 { 70 char *ret; 71 72 if (__isthreaded == 0) 73 ret = ttyname_unthreaded(fd); 74 else 75 ret = ttyname_threaded(fd); 76 return (ret); 77 } 78 79 char * 80 ttyname_r(int fd, char *buf, size_t len) 81 { 82 struct dirent *dirp; 83 DIR *dp; 84 struct stat dsb; 85 struct stat sb; 86 char *rval; 87 int minlen; 88 89 rval = NULL; 90 91 /* Must be a terminal. */ 92 if (!isatty(fd)) 93 return (rval); 94 /* Must be a character device. */ 95 if (__sys_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 96 return (rval); 97 /* Must have enough room */ 98 if (len <= sizeof(_PATH_DEV)) 99 return (rval); 100 101 if ((dp = opendir(_PATH_DEV)) != NULL) { 102 memcpy(buf, _PATH_DEV, sizeof(_PATH_DEV)); 103 for (rval = NULL; (dirp = readdir(dp)) != NULL;) { 104 if (dirp->d_ino != sb.st_ino) 105 continue; 106 minlen = (len - (sizeof(_PATH_DEV) - 1)) < (dirp->d_namlen + 1) ? 107 (len - (sizeof(_PATH_DEV) - 1)) : (dirp->d_namlen + 1); 108 memcpy(buf + sizeof(_PATH_DEV) - 1, dirp->d_name, minlen); 109 if (stat(buf, &dsb) || sb.st_dev != dsb.st_dev || 110 sb.st_ino != dsb.st_ino) 111 continue; 112 rval = buf; 113 break; 114 } 115 closedir(dp); 116 } 117 return (rval); 118 } 119 120 char * 121 ttyname_threaded(int fd) 122 { 123 char *buf; 124 125 if (ttyname_init == 0) { 126 _pthread_mutex_lock(&ttyname_lock); 127 if (ttyname_init == 0) { 128 if (_pthread_key_create(&ttyname_key, free)) { 129 _pthread_mutex_unlock(&ttyname_lock); 130 return (NULL); 131 } 132 ttyname_init = 1; 133 } 134 _pthread_mutex_unlock(&ttyname_lock); 135 } 136 137 /* Must have thread specific data field to put data */ 138 if ((buf = _pthread_getspecific(ttyname_key)) == NULL) { 139 if ((buf = malloc(TTY_PATH_MAX)) != NULL) { 140 if (_pthread_setspecific(ttyname_key, buf) != 0) { 141 free(buf); 142 return (NULL); 143 } 144 } else { 145 return (NULL); 146 } 147 } 148 return (ttyname_r(fd, buf, TTY_PATH_MAX)); 149 } 150 151 static char * 152 ttyname_unthreaded(int fd) 153 { 154 struct stat sb; 155 struct termios ttyb; 156 DB *db; 157 DBT data, key; 158 struct { 159 mode_t type; 160 dev_t dev; 161 } bkey; 162 163 /* Must be a terminal. */ 164 if (tcgetattr(fd, &ttyb) < 0) 165 return (NULL); 166 /* Must be a character device. */ 167 if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 168 return (NULL); 169 170 if ( (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) ) { 171 memset(&bkey, 0, sizeof(bkey)); 172 bkey.type = S_IFCHR; 173 bkey.dev = sb.st_rdev; 174 key.data = &bkey; 175 key.size = sizeof(bkey); 176 if (!(db->get)(db, &key, &data, 0) && 177 (sizeof(_PATH_DEV) + data.size - 1 < sizeof(static_buf))) { 178 bcopy(data.data, 179 static_buf + sizeof(_PATH_DEV) - 1, data.size); 180 (db->close)(db); 181 return (static_buf); 182 } 183 (db->close)(db); 184 } 185 return (oldttyname(fd, &sb)); 186 } 187 188 static char * 189 oldttyname(int fd __unused, struct stat *sb) 190 { 191 struct dirent *dirp; 192 DIR *dp; 193 struct stat dsb; 194 195 if ((dp = opendir(_PATH_DEV)) == NULL) 196 return (NULL); 197 198 while ( (dirp = readdir(dp)) ) { 199 if (dirp->d_ino != sb->st_ino) 200 continue; 201 if (sizeof(_PATH_DEV) + dirp->d_namlen >= sizeof(static_buf)) 202 continue; 203 bcopy(dirp->d_name, static_buf + sizeof(_PATH_DEV) - 1, 204 dirp->d_namlen + 1); 205 if (stat(static_buf, &dsb) || sb->st_dev != dsb.st_dev || 206 sb->st_ino != dsb.st_ino) 207 continue; 208 closedir(dp); 209 return (static_buf); 210 } 211 closedir(dp); 212 return (NULL); 213 } 214