gen/FreeBSD/ttyname.c

   1 /*
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)ttyname.c   8.2 (Berkeley) 1/27/94";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/gen/ttyname.c,v 1.16 2004/01/06 18:26:14 nectar Exp $");
  39
  40 #include "namespace.h"
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <fcntl.h>
  44 #include <dirent.h>
  45 #include <stdlib.h>
  46 #include <termios.h>
  47 #include <unistd.h>
  48 #include <string.h>
  49 #include <paths.h>
  50 #include <pthread.h>
  51 #include "un-namespace.h"
  52
  53 #include "libc_private.h"
  54
  55 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN];
  56 static char *ttyname_threaded(int fd);
  57 static char *ttyname_unthreaded(int fd);
  58
  59 static pthread_mutex_t  ttyname_lock = PTHREAD_MUTEX_INITIALIZER;
  60 static pthread_key_t    ttyname_key;
  61 static int              ttyname_init = 0;
  62
  63 char *
  64 ttyname(int fd)
  65 {
  66         char           *ret;
  67
  68         if (__isthreaded == 0)
  69                 ret = ttyname_unthreaded(fd);
  70         else
  71                 ret = ttyname_threaded(fd);
  72         return (ret);
  73 }
  74
  75 char *
  76 ttyname_r(int fd, char *buf, size_t len)
  77 {
  78         struct stat     sb;
  79         char            *rval;
  80
  81         rval = NULL;
  82
  83         /* Must be a terminal. */
  84         if (!isatty(fd))
  85                 return (rval);
  86         /* Must be a character device. */
  87         if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
  88                 return (rval);
  89         /* Must have enough room */
  90         if (len <= sizeof(_PATH_DEV))
  91                 return (rval);
  92
  93         strcpy(buf, _PATH_DEV);
  94         devname_r(sb.st_rdev, S_IFCHR,
  95             buf + strlen(buf), sizeof(buf) - strlen(buf));
  96         return (buf);
  97 }
  98
  99 static char *
 100 ttyname_threaded(int fd)
 101 {
 102         char    *buf;
 103
 104         if (ttyname_init == 0) {
 105                 _pthread_mutex_lock(&ttyname_lock);
 106                 if (ttyname_init == 0) {
 107                         if (_pthread_key_create(&ttyname_key, free)) {
 108                                 _pthread_mutex_unlock(&ttyname_lock);
 109                                 return (NULL);
 110                         }
 111                         ttyname_init = 1;
 112                 }
 113                 _pthread_mutex_unlock(&ttyname_lock);
 114         }
 115
 116         /* Must have thread specific data field to put data */
 117         if ((buf = _pthread_getspecific(ttyname_key)) == NULL) {
 118                 if ((buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) {
 119                         if (_pthread_setspecific(ttyname_key, buf) != 0) {
 120                                 free(buf);
 121                                 return (NULL);
 122                         }
 123                 } else {
 124                         return (NULL);
 125                 }
 126         }
 127         return (ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN));
 128 }
 129
 130 static char *
 131 ttyname_unthreaded(int fd)
 132 {
 133         struct stat     sb;
 134         struct termios  ttyb;
 135
 136         /* Must be a terminal. */
 137         if (tcgetattr(fd, &ttyb) < 0)
 138                 return (NULL);
 139         /* Must be a character device. */
 140         if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
 141                 return (NULL);
 142
 143         strcpy(buf, _PATH_DEV);
 144         devname_r(sb.st_rdev, S_IFCHR,
 145             buf + strlen(buf), sizeof(buf) - strlen(buf));
 146         return (buf);
 147 }