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 1.12 2005/08/27 20:23:05 joerg 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 __P((int, struct stat *)); 59 static char *ttyname_threaded(int fd); 60 static char *ttyname_unthreaded(int fd); 61 62 static pthread_mutex_t ttyname_lock = PTHREAD_MUTEX_INITIALIZER; 63 static pthread_key_t ttyname_key; 64 static int ttyname_init = 0; 65 66 char * 67 ttyname(int fd) 68 { 69 char *ret; 70 71 if (__isthreaded == 0) 72 ret = ttyname_unthreaded(fd); 73 else 74 ret = ttyname_threaded(fd); 75 return (ret); 76 } 77 78 char * 79 ttyname_r(int fd, char *buf, size_t len) 80 { 81 struct dirent *dirp; 82 DIR *dp; 83 struct stat dsb; 84 struct stat sb; 85 char *rval; 86 int minlen; 87 88 rval = NULL; 89 90 /* Must be a terminal. */ 91 if (!isatty(fd)) 92 return (rval); 93 /* Must be a character device. */ 94 if (__sys_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 95 return (rval); 96 /* Must have enough room */ 97 if (len <= sizeof(_PATH_DEV)) 98 return (rval); 99 100 if ((dp = opendir(_PATH_DEV)) != NULL) { 101 memcpy(buf, _PATH_DEV, sizeof(_PATH_DEV)); 102 for (rval = NULL; (dirp = readdir(dp)) != NULL;) { 103 if (dirp->d_ino != sb.st_ino) 104 continue; 105 minlen = (len - (sizeof(_PATH_DEV) - 1)) < (dirp->d_namlen + 1) ? 106 (len - (sizeof(_PATH_DEV) - 1)) : (dirp->d_namlen + 1); 107 memcpy(buf + sizeof(_PATH_DEV) - 1, dirp->d_name, minlen); 108 if (stat(buf, &dsb) || sb.st_dev != dsb.st_dev || 109 sb.st_ino != dsb.st_ino) 110 continue; 111 rval = buf; 112 break; 113 } 114 (void) closedir(dp); 115 } 116 return (rval); 117 } 118 119 char * 120 ttyname_threaded(int fd) 121 { 122 char *buf; 123 124 if (ttyname_init == 0) { 125 _pthread_mutex_lock(&ttyname_lock); 126 if (ttyname_init == 0) { 127 if (_pthread_key_create(&ttyname_key, free)) { 128 _pthread_mutex_unlock(&ttyname_lock); 129 return (NULL); 130 } 131 ttyname_init = 1; 132 } 133 _pthread_mutex_unlock(&ttyname_lock); 134 } 135 136 /* Must have thread specific data field to put data */ 137 if ((buf = _pthread_getspecific(ttyname_key)) == NULL) { 138 if ((buf = malloc(TTY_PATH_MAX)) != NULL) { 139 if (_pthread_setspecific(ttyname_key, buf) != 0) { 140 free(buf); 141 return (NULL); 142 } 143 } else { 144 return (NULL); 145 } 146 } 147 return (ttyname_r(fd, buf, TTY_PATH_MAX)); 148 } 149 150 static char * 151 ttyname_unthreaded(int fd) 152 { 153 struct stat sb; 154 struct termios ttyb; 155 DB *db; 156 DBT data, key; 157 struct { 158 mode_t type; 159 dev_t dev; 160 } bkey; 161 162 /* Must be a terminal. */ 163 if (tcgetattr(fd, &ttyb) < 0) 164 return (NULL); 165 /* Must be a character device. */ 166 if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 167 return (NULL); 168 169 if ( (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) ) { 170 memset(&bkey, 0, sizeof(bkey)); 171 bkey.type = S_IFCHR; 172 bkey.dev = sb.st_rdev; 173 key.data = &bkey; 174 key.size = sizeof(bkey); 175 if (!(db->get)(db, &key, &data, 0) && 176 (sizeof(_PATH_DEV) + data.size - 1 < sizeof(static_buf))) { 177 bcopy(data.data, 178 static_buf + sizeof(_PATH_DEV) - 1, data.size); 179 (void)(db->close)(db); 180 return (static_buf); 181 } 182 (void)(db->close)(db); 183 } 184 return (oldttyname(fd, &sb)); 185 } 186 187 static char * 188 oldttyname(fd, sb) 189 int fd __unused; 190 struct stat *sb; 191 { 192 struct dirent *dirp; 193 DIR *dp; 194 struct stat dsb; 195 196 if ((dp = opendir(_PATH_DEV)) == NULL) 197 return (NULL); 198 199 while ( (dirp = readdir(dp)) ) { 200 if (dirp->d_ino != sb->st_ino) 201 continue; 202 if (sizeof(_PATH_DEV) + dirp->d_namlen >= sizeof(static_buf)) 203 continue; 204 bcopy(dirp->d_name, static_buf + sizeof(_PATH_DEV) - 1, 205 dirp->d_namlen + 1); 206 if (stat(static_buf, &dsb) || sb->st_dev != dsb.st_dev || 207 sb->st_ino != dsb.st_ino) 208 continue; 209 (void)closedir(dp); 210 return (static_buf); 211 } 212 (void)closedir(dp); 213 return (NULL); 214 } 215