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 * from: @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 34 * $Id: tty_tty.c,v 1.9 1994/05/12 03:48:37 cgd 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 cttyopen(dev, flag, mode, p) 53 dev_t dev; 54 int flag, mode; 55 struct proc *p; 56 { 57 struct vnode *ttyvp = cttyvp(p); 58 int error; 59 60 if (ttyvp == NULL) 61 return (ENXIO); 62 VOP_LOCK(ttyvp); 63 #ifdef PARANOID 64 /* 65 * Since group is tty and mode is 620 on most terminal lines 66 * and since sessions protect terminals from processes outside 67 * your session, this check is probably no longer necessary. 68 * Since it inhibits setuid root programs that later switch 69 * to another user from accessing /dev/tty, we have decided 70 * to delete this test. (mckusick 5/93) 71 */ 72 error = VOP_ACCESS(ttyvp, 73 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 74 if (!error) 75 #endif /* PARANOID */ 76 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 77 VOP_UNLOCK(ttyvp); 78 return (error); 79 } 80 81 /*ARGSUSED*/ 82 cttyread(dev, uio, flag) 83 dev_t dev; 84 struct uio *uio; 85 int flag; 86 { 87 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 88 int error; 89 90 if (ttyvp == NULL) 91 return (EIO); 92 VOP_LOCK(ttyvp); 93 error = VOP_READ(ttyvp, uio, flag, NOCRED); 94 VOP_UNLOCK(ttyvp); 95 return (error); 96 } 97 98 /*ARGSUSED*/ 99 cttywrite(dev, uio, flag) 100 dev_t dev; 101 struct uio *uio; 102 int flag; 103 { 104 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 105 int error; 106 107 if (ttyvp == NULL) 108 return (EIO); 109 VOP_LOCK(ttyvp); 110 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 111 VOP_UNLOCK(ttyvp); 112 return (error); 113 } 114 115 /*ARGSUSED*/ 116 cttyioctl(dev, cmd, addr, flag, p) 117 dev_t dev; 118 int cmd; 119 caddr_t addr; 120 int flag; 121 struct proc *p; 122 { 123 struct vnode *ttyvp = cttyvp(p); 124 125 if (ttyvp == NULL) 126 return (EIO); 127 if (cmd == TIOCSCTTY) /* XXX */ 128 return (EINVAL); 129 if (cmd == TIOCNOTTY) { 130 if (!SESS_LEADER(p)) { 131 p->p_flag &= ~P_CONTROLT; 132 return (0); 133 } else 134 return (EINVAL); 135 } 136 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 137 } 138 139 /*ARGSUSED*/ 140 cttyselect(dev, flag, p) 141 dev_t dev; 142 int flag; 143 struct proc *p; 144 { 145 struct vnode *ttyvp = cttyvp(p); 146 147 if (ttyvp == NULL) 148 return (1); /* try operation to get EOF/failure */ 149 return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p)); 150 } 151