bsd/kern/tty_tty.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1997 Apple Computer, Inc. All Rights Reserved */
  23 /*-
  24  * Copyright (c) 1982, 1986, 1991, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  *      @(#)tty_tty.c   8.2 (Berkeley) 9/23/93
  56  */
  57
  58 /*
  59  * Indirect driver for controlling tty.
  60  */
  61 #include <sys/param.h>
  62 #include <sys/systm.h>
  63 #include <sys/conf.h>
  64 #include <sys/ioctl.h>
  65 #include <sys/proc.h>
  66 #include <sys/tty.h>
  67 #include <sys/vnode.h>
  68 #include <sys/file.h>
  69 #ifndef NeXT
  70 #include <sys/kernel.h>
  71 #ifdef DEVFS
  72 #include <sys/devfsext.h>
  73 #endif /*DEVFS*/
  74
  75 static  d_open_t        cttyopen;
  76 static  d_read_t        cttyread;
  77 static  d_write_t       cttywrite;
  78 static  d_ioctl_t       cttyioctl;
  79 static  d_select_t      cttyselect;
  80
  81 #define CDEV_MAJOR 1
  82 /* Don't make static, fdesc_vnops uses this. */
  83 struct cdevsw ctty_cdevsw =
  84         { cttyopen,     nullclose,      cttyread,       cttywrite,      /*1*/
  85           cttyioctl,    nullstop,       nullreset,      nodevtotty,/* tty */
  86           cttyselect,   nommap,         NULL,   "ctty", NULL,   -1 };
  87
  88 #endif /* !NeXT */
  89
  90 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
  91
  92 /*ARGSUSED*/
  93 int
  94 cttyopen(dev, flag, mode, p)
  95         dev_t dev;
  96         int flag, mode;
  97         struct proc *p;
  98 {
  99         struct vnode *ttyvp = cttyvp(p);
 100         int error;
 101
 102         if (ttyvp == NULL)
 103                 return (ENXIO);
 104 #ifndef NeXT
 105         VOP_LOCK(ttyvp);
 106 #else
 107         /*
 108          * This is the only place that NeXT Guarding has been used for
 109          * VOP_.*LOCK style calls.  Note all of the other diffs should
 110          * use the three paramater lock/unlock.
 111          */
 112         vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
 113 #endif
 114
 115 #ifdef PARANOID
 116         /*
 117          * Since group is tty and mode is 620 on most terminal lines
 118          * and since sessions protect terminals from processes outside
 119          * your session, this check is probably no longer necessary.
 120          * Since it inhibits setuid root programs that later switch
 121          * to another user from accessing /dev/tty, we have decided
 122          * to delete this test. (mckusick 5/93)
 123          */
 124         error = VOP_ACCESS(ttyvp,
 125           (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
 126         if (!error)
 127 #endif /* PARANOID */
 128                 error = VOP_OPEN(ttyvp, flag, NOCRED, p);
 129         VOP_UNLOCK(ttyvp, 0, p);
 130         return (error);
 131 }
 132
 133 /*ARGSUSED*/
 134 int
 135 cttyread(dev, uio, flag)
 136         dev_t dev;
 137         struct uio *uio;
 138         int flag;
 139 {
 140         struct proc *p = uio->uio_procp;
 141         register struct vnode *ttyvp = cttyvp(uio->uio_procp);
 142         int error;
 143
 144         if (ttyvp == NULL)
 145                 return (EIO);
 146         vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
 147         error = VOP_READ(ttyvp, uio, flag, NOCRED);
 148         VOP_UNLOCK(ttyvp, 0, p);
 149         return (error);
 150 }
 151
 152 /*ARGSUSED*/
 153 int
 154 cttywrite(dev, uio, flag)
 155         dev_t dev;
 156         struct uio *uio;
 157         int flag;
 158 {
 159         struct proc *p = uio->uio_procp;
 160         register struct vnode *ttyvp = cttyvp(uio->uio_procp);
 161         int error;
 162
 163         if (ttyvp == NULL)
 164                 return (EIO);
 165         vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
 166         error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
 167         VOP_UNLOCK(ttyvp, 0, p);
 168         return (error);
 169 }
 170
 171 /*ARGSUSED*/
 172 #ifndef NeXT
 173 static  int
 174 cttyioctl(dev, cmd, addr, flag, p)
 175         dev_t dev;
 176         int cmd;
 177         caddr_t addr;
 178         int flag;
 179         struct proc *p;
 180 #else
 181 int
 182 cttyioctl(dev, cmd, addr, flag, p)
 183         dev_t dev;
 184         u_long cmd;
 185         caddr_t addr;
 186         int flag;
 187         struct proc *p;
 188 #endif /* !NeXT */
 189 {
 190         struct vnode *ttyvp = cttyvp(p);
 191
 192         if (ttyvp == NULL)
 193                 return (EIO);
 194         if (cmd == TIOCSCTTY)  /* don't allow controlling tty to be set    */
 195                 return EINVAL; /* to controlling tty -- infinite recursion */
 196         if (cmd == TIOCNOTTY) {
 197                 if (!SESS_LEADER(p)) {
 198                         p->p_flag &= ~P_CONTROLT;
 199                         return (0);
 200                 } else
 201                         return (EINVAL);
 202         }
 203         return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
 204 }
 205
 206 /*ARGSUSED*/
 207 int
 208 cttyselect(dev, flag, p)
 209         dev_t dev;
 210         int flag;
 211         struct proc *p;
 212 {
 213         struct vnode *ttyvp = cttyvp(p);
 214
 215         if (ttyvp == NULL)
 216                 return (1);     /* try operation to get EOF/failure */
 217         return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p));
 218 }
 219
 220 #ifndef NeXT
 221 static ctty_devsw_installed = 0;
 222 #ifdef DEVFS
 223 static  void    *ctty_devfs_token;
 224 #endif
 225
 226 static void
 227 ctty_drvinit(void *unused)
 228 {
 229         dev_t dev;
 230
 231         if( ! ctty_devsw_installed ) {
 232                 dev = makedev(CDEV_MAJOR,0);
 233                 cdevsw_add(&dev,&ctty_cdevsw,NULL);
 234                 ctty_devsw_installed = 1;
 235 #ifdef DEVFS
 236                 ctty_devfs_token =
 237                         devfs_add_devswf(&ctty_cdevsw, 0, DV_CHR, 0, 0,
 238                                         0666, "tty");
 239 #endif
 240         }
 241 }
 242
 243 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL)
 244
 245
 246 #endif /* !NeXT */