stdlib/grantpt.c

   1 /*
   2  * Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <stdlib.h>
  25 #include <sys/ioctl.h>
  26 #include <sys/stat.h>
  27 #include <fcntl.h>
  28 #include <errno.h>
  29
  30 /*
  31  * posix_openpt call for cloning pty implementation.
  32  *
  33  * Just open /dev/ptmx
  34  */
  35 int
  36 posix_openpt(int flags)
  37 {
  38         int fd = open("/dev/ptmx", flags);
  39         if (fd >= 0)
  40                 return fd;
  41         return -1;
  42 }
  43
  44 /*
  45  * grantpt call for cloning pty implementation.
  46  *
  47  * Change UID and GID of slave pty associated with master pty whose
  48  * fd is provided, to the real UID and real GID of the calling thread.
  49  */
  50 int
  51 grantpt(int fd)
  52 {
  53         return ioctl(fd, TIOCPTYGRANT);
  54 }
  55
  56 /*
  57  * ptsname call for cloning pty implementation.
  58  *
  59  * NOTE: Returns a pointer to a static buffer, which will be overwritten on
  60  * subsequent calls.
  61  */
  62 char *
  63 ptsname(int fd)
  64 {
  65         static char ptsnamebuf[ 128];   /* ioctl knows length */
  66         int error;
  67         char *retval = NULL;
  68         struct stat sbuf;
  69
  70         error = ioctl(fd, TIOCPTYGNAME, ptsnamebuf);
  71         if (!error) {
  72                 /*
  73                  * XXX TSD
  74                  *
  75                  * POSIX: Handle device rename test case, which is expected
  76                  * to fail if the pty has been renamed.
  77                  */
  78                 if (stat(ptsnamebuf, &sbuf) == 0)
  79                         retval = ptsnamebuf;
  80         }
  81
  82         return (retval);
  83 }
  84
  85 /*
  86  * unlockpt call for cloning pty implementation.
  87  *
  88  * Unlock the slave pty associated with the master to which fd refers.
  89  */
  90 int
  91 unlockpt(int fd)
  92 {
  93         return ioctl(fd, TIOCPTYUNLK);
  94 }