lib/libc/gen/ttyname.c

   1 /*      $NetBSD: ttyname.c,v 1.26 2012/06/12 18:17:04 joerg 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 1.26 2012/06/12 18:17:04 joerg Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42 #include <sys/ioctl.h>
  43 #include <sys/stat.h>
  44
  45 #include <assert.h>
  46 #include <errno.h>
  47 #include <limits.h>
  48 #include <paths.h>
  49 #include <string.h>
  50 #include <stdlib.h>
  51 #include <termios.h>
  52 #include <unistd.h>
  53
  54 #ifdef __weak_alias
  55 __weak_alias(ttyname,_ttyname)
  56 __weak_alias(ttyname_r,_ttyname_r)
  57 #endif
  58
  59 #ifdef __minix
  60 /* LSC: We do not have devname functionality on Minix, so re-import for now
  61  * old, manual way of doing it.*/
  62 #include <dirent.h>
  63 static int
  64 oldttyname(const struct stat *sb, char *buf, size_t len)
  65 {
  66         struct dirent *dirp;
  67         DIR *dp;
  68         struct stat dsb;
  69         size_t dlen;
  70
  71         _DIAGASSERT(sb != NULL);
  72
  73         if ((dp = opendir(_PATH_DEV)) == NULL)
  74                 return -1;
  75
  76         while ((dirp = readdir(dp)) != NULL) {
  77 #define DEVSZ (sizeof(_PATH_DEV) - 1)
  78                 if (dirp->d_fileno != sb->st_ino)
  79                         continue;
  80                 dlen = strlen(dirp->d_name);
  81                 if (len - DEVSZ <= dlen) {
  82                         /*
  83                          * XXX: we return an error if *any* entry does not
  84                          * fit
  85                          */
  86                         errno = ERANGE;
  87                         (void)closedir(dp);
  88                         return -1;
  89                 }
  90                 (void)memcpy(buf + DEVSZ, dirp->d_name, dlen);
  91                 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev ||
  92                     sb->st_ino != dsb.st_ino)
  93                         continue;
  94                 (void)closedir(dp);
  95                 return 0;
  96 #undef DEVSZ
  97         }
  98         (void)closedir(dp);
  99         /*
 100          * XXX: Documented by TOG to return EBADF or ENOTTY only; neither are
 101          * applicable here.
 102          */
 103         errno = ENOENT;
 104         return -1;
 105 }
 106
 107 #endif
 108
 109 int
 110 ttyname_r(int fd, char *buf, size_t len)
 111 {
 112         struct stat sb;
 113         struct termios ttyb;
 114 #ifndef __minix
 115         struct ptmget ptm;
 116 #endif
 117
 118         _DIAGASSERT(fd != -1);
 119
 120 #ifndef __minix
 121         /* If it is a pty, deal with it quickly */
 122         if (ioctl(fd, TIOCPTSNAME, &ptm) != -1) {
 123                 if (strlcpy(buf, ptm.sn, len) >= len) {
 124                         return ERANGE;
 125                 }
 126                 return 0;
 127         }
 128 #endif
 129
 130         /* Must be a terminal. */
 131         if (tcgetattr(fd, &ttyb) == -1)
 132                 return errno;
 133
 134         if (fstat(fd, &sb))
 135                 return errno;
 136
 137         if (strlcpy(buf, _PATH_DEV, len) >= len)
 138                 return ERANGE;
 139
 140 #ifdef __minix
 141         if (oldttyname(&sb, buf, len) == -1)
 142                 return errno;
 143         return 0;
 144 #else
 145         buf += strlen(_PATH_DEV);
 146         len -= strlen(_PATH_DEV);
 147         return devname_r(sb.st_rdev, sb.st_mode & S_IFMT, buf, len);
 148 #endif
 149 }
 150
 151
 152 char *
 153 ttyname(int fd)
 154 {
 155         static char buf[PATH_MAX];
 156         int rv;
 157
 158         rv = ttyname_r(fd, buf, sizeof(buf));
 159         if (rv != 0) {
 160                 errno = rv;
 161                 return NULL;
 162         }
 163         return buf;
 164 }