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 1.3 1994/08/02 07:42:57 davidg 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 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 50 51 /*ARGSUSED*/ 52 int 53 cttyopen(dev, flag, mode, p) 54 dev_t dev; 55 int flag, mode; 56 struct proc *p; 57 { 58 struct vnode *ttyvp = cttyvp(p); 59 int error; 60 61 if (ttyvp == NULL) 62 return (ENXIO); 63 VOP_LOCK(ttyvp); 64 #ifdef PARANOID 65 /* 66 * Since group is tty and mode is 620 on most terminal lines 67 * and since sessions protect terminals from processes outside 68 * your session, this check is probably no longer necessary. 69 * Since it inhibits setuid root programs that later switch 70 * to another user from accessing /dev/tty, we have decided 71 * to delete this test. (mckusick 5/93) 72 */ 73 error = VOP_ACCESS(ttyvp, 74 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 75 if (!error) 76 #endif /* PARANOID */ 77 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 78 VOP_UNLOCK(ttyvp); 79 return (error); 80 } 81 82 /*ARGSUSED*/ 83 int 84 cttyread(dev, uio, flag) 85 dev_t dev; 86 struct uio *uio; 87 int flag; 88 { 89 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 90 int error; 91 92 if (ttyvp == NULL) 93 return (EIO); 94 VOP_LOCK(ttyvp); 95 error = VOP_READ(ttyvp, uio, flag, NOCRED); 96 VOP_UNLOCK(ttyvp); 97 return (error); 98 } 99 100 /*ARGSUSED*/ 101 int 102 cttywrite(dev, uio, flag) 103 dev_t dev; 104 struct uio *uio; 105 int flag; 106 { 107 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 108 int error; 109 110 if (ttyvp == NULL) 111 return (EIO); 112 VOP_LOCK(ttyvp); 113 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 114 VOP_UNLOCK(ttyvp); 115 return (error); 116 } 117 118 /*ARGSUSED*/ 119 int 120 cttyioctl(dev, cmd, addr, flag, p) 121 dev_t dev; 122 int cmd; 123 caddr_t addr; 124 int flag; 125 struct proc *p; 126 { 127 struct vnode *ttyvp = cttyvp(p); 128 129 if (ttyvp == NULL) 130 return (EIO); 131 if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */ 132 return EINVAL; /* to controlling tty -- infinite recursion */ 133 if (cmd == TIOCNOTTY) { 134 if (!SESS_LEADER(p)) { 135 p->p_flag &= ~P_CONTROLT; 136 return (0); 137 } else 138 return (EINVAL); 139 } 140 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 141 } 142 143 /*ARGSUSED*/ 144 int 145 cttyselect(dev, flag, p) 146 dev_t dev; 147 int flag; 148 struct proc *p; 149 { 150 struct vnode *ttyvp = cttyvp(p); 151 152 if (ttyvp == NULL) 153 return (1); /* try operation to get EOF/failure */ 154 return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p)); 155 } 156