1 /* $NetBSD: ttyname.c,v 1.11 1997/07/21 14:07:41 jtc Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94"; 40 #else 41 __RCSID("$NetBSD: ttyname.c,v 1.11 1997/07/21 14:07:41 jtc Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <sys/types.h> 47 #include <sys/stat.h> 48 #include <fcntl.h> 49 #include <dirent.h> 50 #include <termios.h> 51 #include <db.h> 52 #include <string.h> 53 #include <unistd.h> 54 #include <paths.h> 55 56 #ifdef __weak_alias 57 __weak_alias(ttyname,_ttyname); 58 #endif 59 60 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV; 61 static char *oldttyname __P((int, struct stat *)); 62 63 char * 64 ttyname(fd) 65 int fd; 66 { 67 struct stat sb; 68 struct termios ttyb; 69 DB *db; 70 DBT data, key; 71 struct { 72 mode_t type; 73 dev_t dev; 74 } bkey; 75 76 /* Must be a terminal. */ 77 if (tcgetattr(fd, &ttyb) < 0) 78 return (NULL); 79 /* Must be a character device. */ 80 if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 81 return (NULL); 82 83 if ((db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) != NULL) { 84 memset(&bkey, 0, sizeof(bkey)); 85 bkey.type = S_IFCHR; 86 bkey.dev = sb.st_rdev; 87 key.data = &bkey; 88 key.size = sizeof(bkey); 89 if (!(db->get)(db, &key, &data, 0)) { 90 bcopy(data.data, 91 buf + sizeof(_PATH_DEV) - 1, data.size); 92 (void)(db->close)(db); 93 return (buf); 94 } 95 (void)(db->close)(db); 96 } 97 return (oldttyname(fd, &sb)); 98 } 99 100 static char * 101 oldttyname(fd, sb) 102 int fd; 103 struct stat *sb; 104 { 105 register struct dirent *dirp; 106 register DIR *dp; 107 struct stat dsb; 108 109 if ((dp = opendir(_PATH_DEV)) == NULL) 110 return (NULL); 111 112 while ((dirp = readdir(dp)) != NULL) { 113 if (dirp->d_fileno != sb->st_ino) 114 continue; 115 bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1, 116 dirp->d_namlen + 1); 117 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev || 118 sb->st_ino != dsb.st_ino) 119 continue; 120 (void)closedir(dp); 121 return (buf); 122 } 123 (void)closedir(dp); 124 return (NULL); 125 } 126