bsd/kern/tty_pty.c

   1 /*
   2  * Copyright (c) 1997-2013 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * Copyright (c) 1982, 1986, 1989, 1993
  30  *      The Regents of the University of California.  All rights reserved.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)tty_pty.c   8.4 (Berkeley) 2/20/95
  61  */
  62
  63 /*
  64  * Pseudo-teletype Driver
  65  * (Actually two drivers, requiring two entries in 'cdevsw')
  66  */
  67 #include "pty.h"                /* XXX */
  68
  69 #include <sys/param.h>
  70 #include <sys/systm.h>
  71 #include <sys/ioctl.h>
  72 #include <sys/proc_internal.h>
  73 #include <sys/kauth.h>
  74 #include <sys/tty.h>
  75 #include <sys/conf.h>
  76 #include <sys/file_internal.h>
  77 #include <sys/uio_internal.h>
  78 #include <sys/kernel.h>
  79 #include <sys/vnode.h>
  80 #include <sys/user.h>
  81 #include <sys/signalvar.h>
  82
  83 #if CONFIG_MACF
  84 #include <security/mac_framework.h>
  85 #endif
  86
  87 #include "tty_dev.h"
  88
  89 #if NPTY == 1
  90 #undef NPTY
  91 #define NPTY    32              /* crude XXX */
  92 #warning        You have only one pty defined, redefining to 32.
  93 #endif
  94
  95 #define PTY_MAJOR 5
  96 #define TTY_MAJOR 4
  97
  98 /*
  99  * pts == /dev/tty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
 100  * ptc == /dev/pty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
 101  */
 102 static struct ptmx_ioctl pt_ioctl[NPTY];
 103
 104 int pty_init(int n_ptys);
 105
 106 #ifndef DEVFS
 107 int
 108 pty_init(__unused int n_ptys)
 109 {
 110         return 0;
 111 }
 112 #else // DEVFS
 113 #include <miscfs/devfs/devfs.h>
 114 #define START_CHAR      'p'
 115 #define HEX_BASE        16
 116
 117 static struct tty_dev_t _pty_driver;
 118
 119 static struct ptmx_ioctl *
 120 pty_get_ioctl(int minor, int open_flag)
 121 {
 122         if (minor >= NPTY) {
 123                 return NULL;
 124         }
 125         struct ptmx_ioctl *pti = &pt_ioctl[minor];
 126         if (open_flag & (PF_OPEN_M|PF_OPEN_S)) {
 127                 if (!pti->pt_tty) {
 128                         pti->pt_tty = ttymalloc();
 129                 }
 130                 if (!pti->pt_tty) {
 131                         return NULL;
 132                 }
 133         }
 134         return pti;
 135 }
 136
 137 static int
 138 pty_get_name(int minor, char *buffer, size_t size)
 139 {
 140         return snprintf(buffer, size, "/dev/tty%c%x",
 141                         START_CHAR + (minor / HEX_BASE),
 142                         minor % HEX_BASE);
 143 }
 144
 145 int
 146 pty_init(int n_ptys)
 147 {
 148         int i;
 149         int j;
 150
 151         n_ptys = min(n_ptys, NPTY); /* clamp to avoid pt_ioctl overflow */
 152
 153         /* create the pseudo tty device nodes */
 154         for (j = 0; j < 10; j++) {
 155                 for (i = 0; i < HEX_BASE; i++) {
 156                         int m = j * HEX_BASE + i;
 157                         if (m >= n_ptys)
 158                                 goto done;
 159                         pt_ioctl[m].pt_devhandle = devfs_make_node(makedev(TTY_MAJOR, m),
 160                                                                    DEVFS_CHAR, UID_ROOT, GID_WHEEL, 0666,
 161                                                                    "tty%c%x", j + START_CHAR, i);
 162                         (void)devfs_make_node(makedev(PTY_MAJOR, m),
 163                                               DEVFS_CHAR, UID_ROOT, GID_WHEEL, 0666,
 164                                               "pty%c%x", j + START_CHAR, i);
 165                 }
 166         }
 167 done:
 168         _pty_driver.master = PTY_MAJOR;
 169         _pty_driver.slave = TTY_MAJOR;
 170         _pty_driver.open_reset = 1;
 171         _pty_driver.open = &pty_get_ioctl;
 172         _pty_driver.name = &pty_get_name;
 173         tty_dev_register(&_pty_driver);
 174         return (0);
 175 }
 176 #endif // DEVFS