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 38 #include <sys/types.h> 39 #include <sys/stat.h> 40 #include <fcntl.h> 41 #include <dirent.h> 42 #include <stdlib.h> 43 #include <termios.h> 44 #include <unistd.h> 45 #include <db.h> 46 #include <string.h> 47 #include <paths.h> 48 49 #ifdef _THREAD_SAFE 50 #include <pthread.h> 51 #include "pthread_private.h" 52 static pthread_mutex_t ttyname_lock = PTHREAD_MUTEX_INITIALIZER; 53 static pthread_key_t ttyname_key; 54 static int ttyname_init = 0; 55 56 char * 57 ttyname(int fd) 58 { 59 char *ret; 60 61 if (_thread_fd_lock(fd, FD_READ, NULL, __FILE__, __LINE__) == 0) { 62 ret = __ttyname_basic(fd); 63 _thread_fd_unlock(fd, FD_READ); 64 } else { 65 ret = NULL; 66 } 67 68 return (ret); 69 } 70 71 char * 72 __ttyname_r_basic(int fd, char *buf, size_t len) 73 { 74 register struct dirent *dirp; 75 register DIR *dp; 76 struct stat dsb; 77 struct stat sb; 78 char *rval; 79 int minlen; 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 (_thread_sys_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 if ((dp = opendir(_PATH_DEV)) != NULL) { 94 memcpy(buf, _PATH_DEV, sizeof(_PATH_DEV)); 95 for (rval = NULL; (dirp = readdir(dp)) != NULL;) { 96 if (dirp->d_fileno != sb.st_ino) 97 continue; 98 minlen = (len - (sizeof(_PATH_DEV) - 1)) < (dirp->d_namlen + 1) ? 99 (len - (sizeof(_PATH_DEV) - 1)) : (dirp->d_namlen + 1); 100 memcpy(buf + sizeof(_PATH_DEV) - 1, dirp->d_name, minlen); 101 if (stat(buf, &dsb) || sb.st_dev != dsb.st_dev || 102 sb.st_ino != dsb.st_ino) 103 continue; 104 rval = buf; 105 break; 106 } 107 (void) closedir(dp); 108 } 109 return (rval); 110 } 111 112 char * 113 __ttyname_basic(int fd) 114 { 115 char *buf; 116 117 pthread_mutex_lock(&ttyname_lock); 118 if (ttyname_init == 0) { 119 if (pthread_keycreate(&ttyname_key, free)) { 120 pthread_mutex_unlock(&ttyname_lock); 121 return (NULL); 122 } 123 ttyname_init = 1; 124 } 125 pthread_mutex_unlock(&ttyname_lock); 126 127 /* Must have thread specific data field to put data */ 128 if (pthread_getspecific(ttyname_key, (void **) &buf) != 0) { 129 return (NULL); 130 } else if (buf == NULL) { 131 if ((buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) { 132 if (pthread_setspecific(ttyname_key, buf) != 0) { 133 free(buf); 134 return (NULL); 135 } 136 } else { 137 return (NULL); 138 } 139 } 140 return (__ttyname_r_basic(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN)); 141 } 142 143 char * 144 ttyname_r(int fd, char *buf, size_t len) 145 { 146 char *ret; 147 148 if (_thread_fd_lock(fd, FD_READ, NULL, __FILE__, __LINE__) == 0) { 149 ret = __ttyname_r_basic(fd, buf, len); 150 _thread_fd_unlock(fd, FD_READ); 151 } else { 152 ret = NULL; 153 } 154 return (ret); 155 } 156 #else 157 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV; 158 static char *oldttyname __P((int, struct stat *)); 159 160 char * 161 ttyname(fd) 162 int fd; 163 { 164 struct stat sb; 165 struct termios ttyb; 166 DB *db; 167 DBT data, key; 168 struct { 169 mode_t type; 170 dev_t dev; 171 } bkey; 172 173 /* Must be a terminal. */ 174 if (tcgetattr(fd, &ttyb) < 0) 175 return (NULL); 176 /* Must be a character device. */ 177 if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 178 return (NULL); 179 180 if (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) { 181 memset(&bkey, 0, sizeof(bkey)); 182 bkey.type = S_IFCHR; 183 bkey.dev = sb.st_rdev; 184 key.data = &bkey; 185 key.size = sizeof(bkey); 186 if (!(db->get)(db, &key, &data, 0)) { 187 bcopy(data.data, 188 buf + sizeof(_PATH_DEV) - 1, data.size); 189 (void)(db->close)(db); 190 return (buf); 191 } 192 (void)(db->close)(db); 193 } 194 return (oldttyname(fd, &sb)); 195 } 196 197 static char * 198 oldttyname(fd, sb) 199 int fd; 200 struct stat *sb; 201 { 202 register struct dirent *dirp; 203 register DIR *dp; 204 struct stat dsb; 205 206 if ((dp = opendir(_PATH_DEV)) == NULL) 207 return (NULL); 208 209 while (dirp = readdir(dp)) { 210 if (dirp->d_fileno != sb->st_ino) 211 continue; 212 bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1, 213 dirp->d_namlen + 1); 214 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev || 215 sb->st_ino != dsb.st_ino) 216 continue; 217 (void)closedir(dp); 218 return (buf); 219 } 220 (void)closedir(dp); 221 return (NULL); 222 } 223 #endif 224