1 /* $NetBSD: ttyname.c,v 1.22 2005/09/25 20:43:54 christos 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94"; 36 #else 37 __RCSID("$NetBSD: ttyname.c,v 1.22 2005/09/25 20:43:54 christos Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 #include <sys/types.h> 43 #include <sys/param.h> 44 #include <sys/stat.h> 45 46 #include <assert.h> 47 #include <db.h> 48 #include <dirent.h> 49 #include <errno.h> 50 #include <fcntl.h> 51 #include <paths.h> 52 #include <string.h> 53 #include <termios.h> 54 #include <unistd.h> 55 #include <sys/ioctl.h> 56 57 #ifdef __weak_alias 58 __weak_alias(ttyname,_ttyname) 59 __weak_alias(ttyname_r,_ttyname_r) 60 #endif 61 62 static int oldttyname(const struct stat *, char *, size_t); 63 64 int 65 ttyname_r(int fd, char *buf, size_t len) 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 struct ptmget ptm; 76 #define DEVSZ (sizeof(_PATH_DEV) - 1) 77 78 _DIAGASSERT(fd != -1); 79 80 if (len <= DEVSZ) { 81 errno = ERANGE; 82 return -1; 83 } 84 85 /* If it is a pty, deal with it quickly */ 86 if (ioctl(fd, TIOCPTSNAME, &ptm) != -1) { 87 if (strlcpy(buf, ptm.sn, len) >= len) { 88 errno = ERANGE; 89 return -1; 90 } 91 return 0; 92 } 93 /* Must be a terminal. */ 94 if (tcgetattr(fd, &ttyb) == -1) 95 return -1; 96 97 /* Must be a character device. */ 98 if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 99 return -1; 100 101 (void)memcpy(buf, _PATH_DEV, DEVSZ); 102 if ((db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) != NULL) { 103 (void)memset(&bkey, 0, sizeof(bkey)); 104 bkey.type = S_IFCHR; 105 bkey.dev = sb.st_rdev; 106 key.data = &bkey; 107 key.size = sizeof(bkey); 108 if (!(db->get)(db, &key, &data, 0)) { 109 if (len - DEVSZ <= data.size) { 110 errno = ERANGE; 111 return -1; 112 } 113 (void)memcpy(buf + DEVSZ, data.data, data.size); 114 (void)(db->close)(db); 115 return 0; 116 } 117 (void)(db->close)(db); 118 } 119 return oldttyname(&sb, buf, len); 120 } 121 122 static int 123 oldttyname(const struct stat *sb, char *buf, size_t len) 124 { 125 struct dirent *dirp; 126 DIR *dp; 127 struct stat dsb; 128 size_t dlen; 129 130 _DIAGASSERT(sb != NULL); 131 132 if ((dp = opendir(_PATH_DEV)) == NULL) 133 return -1; 134 135 while ((dirp = readdir(dp)) != NULL) { 136 if (dirp->d_fileno != sb->st_ino) 137 continue; 138 dlen = dirp->d_namlen + 1; 139 if (len - DEVSZ <= dlen) { 140 /* 141 * XXX: we return an error if *any* entry does not 142 * fit 143 */ 144 errno = ERANGE; 145 return -1; 146 } 147 (void)memcpy(buf + DEVSZ, dirp->d_name, dlen); 148 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev || 149 sb->st_ino != dsb.st_ino) 150 continue; 151 (void)closedir(dp); 152 return 0; 153 } 154 (void)closedir(dp); 155 /* 156 * XXX: Documented by TOG to return EBADF or ENOTTY only; neither are 157 * applicable here. 158 */ 159 errno = ENOENT; 160 return -1; 161 } 162 163 char * 164 ttyname(int fd) 165 { 166 static char buf[MAXPATHLEN]; 167 return ttyname_r(fd, buf, sizeof(buf)) == -1 ? NULL : buf; 168 } 169