1 /*- 2 * Copyright (c) 1982, 1986, 1991, 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 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 34 * $Id: tty_tty.c,v 1.6 1995/11/29 10:48:30 julian Exp $ 35 */ 36 37 /* 38 * Indirect driver for controlling tty. 39 */ 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/conf.h> 43 #include <sys/ioctl.h> 44 #include <sys/proc.h> 45 #include <sys/tty.h> 46 #include <sys/vnode.h> 47 #include <sys/file.h> 48 49 #ifdef JREMOD 50 #include <sys/kernel.h> 51 #ifdef DEVFS 52 #include <sys/devfsext.h> 53 #endif /*DEVFS*/ 54 #define CDEV_MAJOR 1 55 #endif /*JREMOD*/ 56 57 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 58 59 /*ARGSUSED*/ 60 int 61 cttyopen(dev, flag, mode, p) 62 dev_t dev; 63 int flag, mode; 64 struct proc *p; 65 { 66 struct vnode *ttyvp = cttyvp(p); 67 int error; 68 69 if (ttyvp == NULL) 70 return (ENXIO); 71 VOP_LOCK(ttyvp); 72 #ifdef PARANOID 73 /* 74 * Since group is tty and mode is 620 on most terminal lines 75 * and since sessions protect terminals from processes outside 76 * your session, this check is probably no longer necessary. 77 * Since it inhibits setuid root programs that later switch 78 * to another user from accessing /dev/tty, we have decided 79 * to delete this test. (mckusick 5/93) 80 */ 81 error = VOP_ACCESS(ttyvp, 82 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 83 if (!error) 84 #endif /* PARANOID */ 85 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 86 VOP_UNLOCK(ttyvp); 87 return (error); 88 } 89 90 /*ARGSUSED*/ 91 int 92 cttyread(dev, uio, flag) 93 dev_t dev; 94 struct uio *uio; 95 int flag; 96 { 97 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 98 int error; 99 100 if (ttyvp == NULL) 101 return (EIO); 102 VOP_LOCK(ttyvp); 103 error = VOP_READ(ttyvp, uio, flag, NOCRED); 104 VOP_UNLOCK(ttyvp); 105 return (error); 106 } 107 108 /*ARGSUSED*/ 109 int 110 cttywrite(dev, uio, flag) 111 dev_t dev; 112 struct uio *uio; 113 int flag; 114 { 115 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 116 int error; 117 118 if (ttyvp == NULL) 119 return (EIO); 120 VOP_LOCK(ttyvp); 121 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 122 VOP_UNLOCK(ttyvp); 123 return (error); 124 } 125 126 /*ARGSUSED*/ 127 int 128 cttyioctl(dev, cmd, addr, flag, p) 129 dev_t dev; 130 int cmd; 131 caddr_t addr; 132 int flag; 133 struct proc *p; 134 { 135 struct vnode *ttyvp = cttyvp(p); 136 137 if (ttyvp == NULL) 138 return (EIO); 139 if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */ 140 return EINVAL; /* to controlling tty -- infinite recursion */ 141 if (cmd == TIOCNOTTY) { 142 if (!SESS_LEADER(p)) { 143 p->p_flag &= ~P_CONTROLT; 144 return (0); 145 } else 146 return (EINVAL); 147 } 148 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 149 } 150 151 /*ARGSUSED*/ 152 int 153 cttyselect(dev, flag, p) 154 dev_t dev; 155 int flag; 156 struct proc *p; 157 { 158 struct vnode *ttyvp = cttyvp(p); 159 160 if (ttyvp == NULL) 161 return (1); /* try operation to get EOF/failure */ 162 return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p)); 163 } 164 165 #ifdef JREMOD 166 struct cdevsw ctty_cdevsw = 167 { cttyopen, nullclose, cttyread, cttywrite, /*1*/ 168 cttyioctl, nullstop, nullreset, nodevtotty,/* tty */ 169 cttyselect, nommap, NULL }; 170 171 static ctty_devsw_installed = 0; 172 173 static void ctty_drvinit(void *unused) 174 { 175 dev_t dev; 176 177 if( ! ctty_devsw_installed ) { 178 dev = makedev(CDEV_MAJOR,0); 179 cdevsw_add(&dev,&ctty_cdevsw,NULL); 180 ctty_devsw_installed = 1; 181 #ifdef DEVFS 182 { 183 int x; 184 /* default for a simple device with no probe routine (usually delete this) */ 185 x=devfs_add_devsw( 186 /* path name devsw minor type uid gid perm*/ 187 "/", "tty", major(dev), 0, DV_CHR, 0, 0, 0600); 188 } 189 #endif 190 } 191 } 192 193 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL) 194 195 #endif /* JREMOD */ 196 197