bsd/kern/tty_tty.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1997 Apple Computer, Inc. All Rights Reserved */
  26 /*-
  27  * Copyright (c) 1982, 1986, 1991, 1993
  28  *      The Regents of the University of California.  All rights reserved.
  29  *
  30  * Redistribution and use in source and binary forms, with or without
  31  * modification, are permitted provided that the following conditions
  32  * are met:
  33  * 1. Redistributions of source code must retain the above copyright
  34  *    notice, this list of conditions and the following disclaimer.
  35  * 2. Redistributions in binary form must reproduce the above copyright
  36  *    notice, this list of conditions and the following disclaimer in the
  37  *    documentation and/or other materials provided with the distribution.
  38  * 3. All advertising materials mentioning features or use of this software
  39  *    must display the following acknowledgement:
  40  *      This product includes software developed by the University of
  41  *      California, Berkeley and its contributors.
  42  * 4. Neither the name of the University nor the names of its contributors
  43  *    may be used to endorse or promote products derived from this software
  44  *    without specific prior written permission.
  45  *
  46  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  56  * SUCH DAMAGE.
  57  *
  58  *      @(#)tty_tty.c   8.2 (Berkeley) 9/23/93
  59  */
  60
  61 /*
  62  * Indirect driver for controlling tty.
  63  */
  64 #include <sys/param.h>
  65 #include <sys/systm.h>
  66 #include <sys/conf.h>
  67 #include <sys/ioctl.h>
  68 #include <sys/proc.h>
  69 #include <sys/tty.h>
  70 #include <sys/vnode.h>
  71 #include <sys/file.h>
  72 #ifndef NeXT
  73 #include <sys/kernel.h>
  74 #ifdef DEVFS
  75 #include <sys/devfsext.h>
  76 #endif /*DEVFS*/
  77
  78 static  d_open_t        cttyopen;
  79 static  d_read_t        cttyread;
  80 static  d_write_t       cttywrite;
  81 static  d_ioctl_t       cttyioctl;
  82 static  d_select_t      cttyselect;
  83
  84 #define CDEV_MAJOR 1
  85 /* Don't make static, fdesc_vnops uses this. */
  86 struct cdevsw ctty_cdevsw =
  87         { cttyopen,     nullclose,      cttyread,       cttywrite,      /*1*/
  88           cttyioctl,    nullstop,       nullreset,      nodevtotty,/* tty */
  89           cttyselect,   nommap,         NULL,   "ctty", NULL,   -1 };
  90
  91 #endif /* !NeXT */
  92
  93 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
  94
  95 /*ARGSUSED*/
  96 int
  97 cttyopen(dev, flag, mode, p)
  98         dev_t dev;
  99         int flag, mode;
 100         struct proc *p;
 101 {
 102         struct vnode *ttyvp = cttyvp(p);
 103         int error;
 104
 105         if (ttyvp == NULL)
 106                 return (ENXIO);
 107 #ifndef NeXT
 108         VOP_LOCK(ttyvp);
 109 #else
 110         /*
 111          * This is the only place that NeXT Guarding has been used for
 112          * VOP_.*LOCK style calls.  Note all of the other diffs should
 113          * use the three paramater lock/unlock.
 114          */
 115         vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
 116 #endif
 117
 118 #ifdef PARANOID
 119         /*
 120          * Since group is tty and mode is 620 on most terminal lines
 121          * and since sessions protect terminals from processes outside
 122          * your session, this check is probably no longer necessary.
 123          * Since it inhibits setuid root programs that later switch
 124          * to another user from accessing /dev/tty, we have decided
 125          * to delete this test. (mckusick 5/93)
 126          */
 127         error = VOP_ACCESS(ttyvp,
 128           (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
 129         if (!error)
 130 #endif /* PARANOID */
 131                 error = VOP_OPEN(ttyvp, flag, NOCRED, p);
 132         VOP_UNLOCK(ttyvp, 0, p);
 133         return (error);
 134 }
 135
 136 /*ARGSUSED*/
 137 int
 138 cttyread(dev, uio, flag)
 139         dev_t dev;
 140         struct uio *uio;
 141         int flag;
 142 {
 143         struct proc *p = uio->uio_procp;
 144         register struct vnode *ttyvp = cttyvp(uio->uio_procp);
 145         int error;
 146
 147         if (ttyvp == NULL)
 148                 return (EIO);
 149         vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
 150         error = VOP_READ(ttyvp, uio, flag, NOCRED);
 151         VOP_UNLOCK(ttyvp, 0, p);
 152         return (error);
 153 }
 154
 155 /*ARGSUSED*/
 156 int
 157 cttywrite(dev, uio, flag)
 158         dev_t dev;
 159         struct uio *uio;
 160         int flag;
 161 {
 162         struct proc *p = uio->uio_procp;
 163         register struct vnode *ttyvp = cttyvp(uio->uio_procp);
 164         int error;
 165
 166         if (ttyvp == NULL)
 167                 return (EIO);
 168         vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
 169         error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
 170         VOP_UNLOCK(ttyvp, 0, p);
 171         return (error);
 172 }
 173
 174 /*ARGSUSED*/
 175 #ifndef NeXT
 176 static  int
 177 cttyioctl(dev, cmd, addr, flag, p)
 178         dev_t dev;
 179         int cmd;
 180         caddr_t addr;
 181         int flag;
 182         struct proc *p;
 183 #else
 184 int
 185 cttyioctl(dev, cmd, addr, flag, p)
 186         dev_t dev;
 187         u_long cmd;
 188         caddr_t addr;
 189         int flag;
 190         struct proc *p;
 191 #endif /* !NeXT */
 192 {
 193         struct vnode *ttyvp = cttyvp(p);
 194
 195         if (ttyvp == NULL)
 196                 return (EIO);
 197         if (cmd == TIOCSCTTY)  /* don't allow controlling tty to be set    */
 198                 return EINVAL; /* to controlling tty -- infinite recursion */
 199         if (cmd == TIOCNOTTY) {
 200                 if (!SESS_LEADER(p)) {
 201                         p->p_flag &= ~P_CONTROLT;
 202                         return (0);
 203                 } else
 204                         return (EINVAL);
 205         }
 206         return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
 207 }
 208
 209 /*ARGSUSED*/
 210 int
 211 cttyselect(dev, flag, wql, p)
 212         dev_t dev;
 213         int flag;
 214         void * wql;
 215         struct proc *p;
 216 {
 217         struct vnode *ttyvp = cttyvp(p);
 218
 219         if (ttyvp == NULL)
 220                 return (1);     /* try operation to get EOF/failure */
 221         return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, wql, p));
 222 }
 223
 224 #ifndef NeXT
 225 static ctty_devsw_installed = 0;
 226 #ifdef DEVFS
 227 static  void    *ctty_devfs_token;
 228 #endif
 229
 230 static void
 231 ctty_drvinit(void *unused)
 232 {
 233         dev_t dev;
 234
 235         if( ! ctty_devsw_installed ) {
 236                 dev = makedev(CDEV_MAJOR,0);
 237                 cdevsw_add(&dev,&ctty_cdevsw,NULL);
 238                 ctty_devsw_installed = 1;
 239 #ifdef DEVFS
 240                 ctty_devfs_token =
 241                         devfs_add_devswf(&ctty_cdevsw, 0, DV_CHR, 0, 0,
 242                                         0666, "tty");
 243 #endif
 244         }
 245 }
 246
 247 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL)
 248
 249
 250 #endif /* !NeXT */