gen/ttyname.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1988, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58
  59 #include <sys/types.h>
  60 #include <sys/stat.h>
  61 #include <sys/ioctl.h>
  62 #include <sys/termios.h>
  63
  64 #include <fcntl.h>
  65 #include <dirent.h>
  66 #include <db.h>
  67 #include <string.h>
  68 #include <paths.h>
  69 #include <stdlib.h>
  70
  71 static char *buf = NULL;
  72 static char *oldttyname __P((int, struct stat *));
  73
  74 char *
  75 ttyname(fd)
  76         int fd;
  77 {
  78         struct stat sb;
  79         struct termios term;
  80         DB *db;
  81         DBT data, key;
  82         struct {
  83                 mode_t type;
  84                 dev_t dev;
  85         } bkey;
  86
  87         if( buf == NULL ) {
  88                 buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN);
  89                 if( buf == NULL )
  90                         return NULL;
  91                 strcpy(buf, _PATH_DEV);
  92         }
  93
  94         /* Must be a terminal. */
  95         if (ioctl(fd, TIOCGETA, &term) < 0)
  96                 return (NULL);
  97         /* Must be a character device. */
  98         if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
  99                 return (NULL);
 100
 101         db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL);
 102         if (db) {
 103                 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                         bcopy(data.data,
 110                             buf + sizeof(_PATH_DEV) - 1, data.size);
 111                         (void)(db->close)(db);
 112                         return (buf);
 113                 }
 114                 (void)(db->close)(db);
 115         }
 116         return (oldttyname(fd, &sb));
 117 }
 118
 119 static char *
 120 oldttyname(fd, sb)
 121         int fd;
 122         struct stat *sb;
 123 {
 124         register struct dirent *dirp;
 125         register DIR *dp;
 126         struct stat dsb;
 127
 128         if( buf == NULL ) {
 129                 buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN);
 130                 if( buf == NULL )
 131                         return NULL;
 132                 strcpy(buf, _PATH_DEV);
 133         }
 134         if ((dp = opendir(_PATH_DEV)) == NULL)
 135                 return (NULL);
 136
 137         while ( (dirp = readdir(dp)) ) {
 138                 if (dirp->d_fileno != sb->st_ino)
 139                         continue;
 140                 bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1,
 141                     dirp->d_namlen + 1);
 142                 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev ||
 143                     sb->st_ino != dsb.st_ino)
 144                         continue;
 145                 (void)closedir(dp);
 146                 return (buf);
 147         }
 148         (void)closedir(dp);
 149         return (NULL);
 150 }