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 */ 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94"; 38 #endif /* LIBC_SCCS and not lint */ 39 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <fcntl.h> 43 #include <dirent.h> 44 #include <stdlib.h> 45 #include <termios.h> 46 #include <unistd.h> 47 #include <db.h> 48 #include <string.h> 49 #include <paths.h> 50 51 #ifdef _THREAD_SAFE 52 #include <pthread.h> 53 #include "pthread_private.h" 54 static struct pthread_mutex _ttyname_lockd = PTHREAD_MUTEX_STATIC_INITIALIZER; 55 static pthread_mutex_t ttyname_lock = &_ttyname_lockd; 56 static pthread_key_t ttyname_key; 57 static int ttyname_init = 0; 58 59 char * 60 ttyname(int fd) 61 { 62 char *ret; 63 64 if (_FD_LOCK(fd, FD_READ, NULL) == 0) { 65 ret = __ttyname_basic(fd); 66 _FD_UNLOCK(fd, FD_READ); 67 } else { 68 ret = NULL; 69 } 70 71 return (ret); 72 } 73 74 char * 75 __ttyname_r_basic(int fd, char *buf, size_t len) 76 { 77 register struct dirent *dirp; 78 register DIR *dp; 79 struct stat dsb; 80 struct stat sb; 81 char *rval; 82 int minlen; 83 84 rval = NULL; 85 86 /* Must be a terminal. */ 87 if (!isatty(fd)) 88 return (rval); 89 /* Must be a character device. */ 90 if (__sys_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 91 return (rval); 92 /* Must have enough room */ 93 if (len <= sizeof(_PATH_DEV)) 94 return (rval); 95 96 if ((dp = opendir(_PATH_DEV)) != NULL) { 97 memcpy(buf, _PATH_DEV, sizeof(_PATH_DEV)); 98 for (rval = NULL; (dirp = readdir(dp)) != NULL;) { 99 if (dirp->d_fileno != sb.st_ino) 100 continue; 101 minlen = (len - (sizeof(_PATH_DEV) - 1)) < (dirp->d_namlen + 1) ? 102 (len - (sizeof(_PATH_DEV) - 1)) : (dirp->d_namlen + 1); 103 memcpy(buf + sizeof(_PATH_DEV) - 1, dirp->d_name, minlen); 104 if (stat(buf, &dsb) || sb.st_dev != dsb.st_dev || 105 sb.st_ino != dsb.st_ino) 106 continue; 107 rval = buf; 108 break; 109 } 110 (void) closedir(dp); 111 } 112 return (rval); 113 } 114 115 char * 116 __ttyname_basic(int fd) 117 { 118 char *buf; 119 120 pthread_mutex_lock(&ttyname_lock); 121 if (ttyname_init == 0) { 122 if (pthread_key_create(&ttyname_key, free)) { 123 pthread_mutex_unlock(&ttyname_lock); 124 return (NULL); 125 } 126 ttyname_init = 1; 127 } 128 pthread_mutex_unlock(&ttyname_lock); 129 130 /* Must have thread specific data field to put data */ 131 if ((buf = pthread_getspecific(ttyname_key)) == NULL) { 132 if ((buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) { 133 if (pthread_setspecific(ttyname_key, buf) != 0) { 134 free(buf); 135 return (NULL); 136 } 137 } else { 138 return (NULL); 139 } 140 } 141 return (__ttyname_r_basic(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN)); 142 } 143 144 char * 145 ttyname_r(int fd, char *buf, size_t len) 146 { 147 char *ret; 148 149 if (_FD_LOCK(fd, FD_READ, NULL) == 0) { 150 ret = __ttyname_r_basic(fd, buf, len); 151 _FD_UNLOCK(fd, FD_READ); 152 } else { 153 ret = NULL; 154 } 155 return (ret); 156 } 157 #else 158 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV; 159 static char *oldttyname __P((int, struct stat *)); 160 161 char * 162 ttyname(fd) 163 int fd; 164 { 165 struct stat sb; 166 struct termios ttyb; 167 DB *db; 168 DBT data, key; 169 struct { 170 mode_t type; 171 dev_t dev; 172 } bkey; 173 174 /* Must be a terminal. */ 175 if (tcgetattr(fd, &ttyb) < 0) 176 return (NULL); 177 /* Must be a character device. */ 178 if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 179 return (NULL); 180 181 if ( (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) ) { 182 memset(&bkey, 0, sizeof(bkey)); 183 bkey.type = S_IFCHR; 184 bkey.dev = sb.st_rdev; 185 key.data = &bkey; 186 key.size = sizeof(bkey); 187 if (!(db->get)(db, &key, &data, 0)) { 188 bcopy(data.data, 189 buf + sizeof(_PATH_DEV) - 1, data.size); 190 (void)(db->close)(db); 191 return (buf); 192 } 193 (void)(db->close)(db); 194 } 195 return (oldttyname(fd, &sb)); 196 } 197 198 static char * 199 oldttyname(fd, sb) 200 int fd; 201 struct stat *sb; 202 { 203 register struct dirent *dirp; 204 register DIR *dp; 205 struct stat dsb; 206 207 if ((dp = opendir(_PATH_DEV)) == NULL) 208 return (NULL); 209 210 while ( (dirp = readdir(dp)) ) { 211 if (dirp->d_fileno != sb->st_ino) 212 continue; 213 bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1, 214 dirp->d_namlen + 1); 215 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev || 216 sb->st_ino != dsb.st_ino) 217 continue; 218 (void)closedir(dp); 219 return (buf); 220 } 221 (void)closedir(dp); 222 return (NULL); 223 } 224 #endif 225