lib/libc/gen/ttyname.c

   1 /*      $NetBSD: ttyname.c,v 1.24 2008/06/25 11:47:29 ad 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 1.24 2008/06/25 11:47:29 ad 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 #ifndef __minix
  76         struct ptmget ptm;
  77 #endif
  78 #define DEVSZ (sizeof(_PATH_DEV) - 1)
  79
  80         _DIAGASSERT(fd != -1);
  81
  82         if (len <= DEVSZ) {
  83                 return ERANGE;
  84         }
  85
  86 #ifndef __minix
  87         /* If it is a pty, deal with it quickly */
  88         if (ioctl(fd, TIOCPTSNAME, &ptm) != -1) {
  89                 if (strlcpy(buf, ptm.sn, len) >= len) {
  90                         return ERANGE;
  91                 }
  92                 return 0;
  93         }
  94 #endif
  95         /* Must be a terminal. */
  96         if (tcgetattr(fd, &ttyb) == -1)
  97                 return errno;
  98
  99         /* Must be a character device. */
 100         if (fstat(fd, &sb))
 101                 return errno;
 102         if (!S_ISCHR(sb.st_mode))
 103                 return ENOTTY;
 104
 105         (void)memcpy(buf, _PATH_DEV, DEVSZ);
 106         if ((db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) != NULL) {
 107                 (void)memset(&bkey, 0, sizeof(bkey));
 108                 bkey.type = S_IFCHR;
 109                 bkey.dev = sb.st_rdev;
 110                 key.data = &bkey;
 111                 key.size = sizeof(bkey);
 112                 if (!(db->get)(db, &key, &data, 0)) {
 113                         if (len - DEVSZ <= data.size) {
 114                                 return ERANGE;
 115                         }
 116                         (void)memcpy(buf + DEVSZ, data.data, data.size);
 117                         (void)(db->close)(db);
 118                         return 0;
 119                 }
 120                 (void)(db->close)(db);
 121         }
 122         if (oldttyname(&sb, buf, len) == -1)
 123                 return errno;
 124         return 0;
 125 }
 126
 127 static int
 128 oldttyname(const struct stat *sb, char *buf, size_t len)
 129 {
 130         struct dirent *dirp;
 131         DIR *dp;
 132         struct stat dsb;
 133         size_t dlen;
 134
 135         _DIAGASSERT(sb != NULL);
 136
 137         if ((dp = opendir(_PATH_DEV)) == NULL)
 138                 return -1;
 139
 140         while ((dirp = readdir(dp)) != NULL) {
 141                 if (dirp->d_fileno != sb->st_ino)
 142                         continue;
 143 #ifdef __minix
 144                 dlen = strlen(dirp->d_name);
 145 #else
 146                 dlen = dirp->d_namlen + 1;
 147 #endif
 148                 if (len - DEVSZ <= dlen) {
 149                         /*
 150                          * XXX: we return an error if *any* entry does not
 151                          * fit
 152                          */
 153                         errno = ERANGE;
 154                         (void)closedir(dp);
 155                         return -1;
 156                 }
 157                 (void)memcpy(buf + DEVSZ, dirp->d_name, dlen);
 158                 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev ||
 159                     sb->st_ino != dsb.st_ino)
 160                         continue;
 161                 (void)closedir(dp);
 162                 return 0;
 163         }
 164         (void)closedir(dp);
 165         /*
 166          * XXX: Documented by TOG to return EBADF or ENOTTY only; neither are
 167          * applicable here.
 168          */
 169         errno = ENOENT;
 170         return -1;
 171 }
 172
 173 char *
 174 ttyname(int fd)
 175 {
 176         static char buf[MAXPATHLEN];
 177         int rv;
 178
 179         rv = ttyname_r(fd, buf, sizeof(buf));
 180         if (rv != 0) {
 181                 errno = rv;
 182                 return NULL;
 183         }
 184         return buf;
 185 }