1 /* $NetBSD: tty_tty.c,v 1.14 1996/09/07 12:41:04 mycroft Exp $ */ 2 3 /*- 4 * Copyright (c) 1982, 1986, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 36 */ 37 38 /* 39 * Indirect driver for controlling tty. 40 */ 41 #include <sys/param.h> 42 #include <sys/systm.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 #include <sys/conf.h> 49 50 51 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 52 53 /*ARGSUSED*/ 54 int 55 cttyopen(dev, flag, mode, p) 56 dev_t dev; 57 int flag, mode; 58 struct proc *p; 59 { 60 struct vnode *ttyvp = cttyvp(p); 61 int error; 62 63 if (ttyvp == NULL) 64 return (ENXIO); 65 VOP_LOCK(ttyvp); 66 #ifdef PARANOID 67 /* 68 * Since group is tty and mode is 620 on most terminal lines 69 * and since sessions protect terminals from processes outside 70 * your session, this check is probably no longer necessary. 71 * Since it inhibits setuid root programs that later switch 72 * to another user from accessing /dev/tty, we have decided 73 * to delete this test. (mckusick 5/93) 74 */ 75 error = VOP_ACCESS(ttyvp, 76 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 77 if (!error) 78 #endif /* PARANOID */ 79 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 80 VOP_UNLOCK(ttyvp); 81 return (error); 82 } 83 84 /*ARGSUSED*/ 85 int 86 cttyread(dev, uio, flag) 87 dev_t dev; 88 struct uio *uio; 89 int flag; 90 { 91 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 92 int error; 93 94 if (ttyvp == NULL) 95 return (EIO); 96 VOP_LOCK(ttyvp); 97 error = VOP_READ(ttyvp, uio, flag, NOCRED); 98 VOP_UNLOCK(ttyvp); 99 return (error); 100 } 101 102 /*ARGSUSED*/ 103 int 104 cttywrite(dev, uio, flag) 105 dev_t dev; 106 struct uio *uio; 107 int flag; 108 { 109 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 110 int error; 111 112 if (ttyvp == NULL) 113 return (EIO); 114 VOP_LOCK(ttyvp); 115 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 116 VOP_UNLOCK(ttyvp); 117 return (error); 118 } 119 120 /*ARGSUSED*/ 121 int 122 cttyioctl(dev, cmd, addr, flag, p) 123 dev_t dev; 124 u_long cmd; 125 caddr_t addr; 126 int flag; 127 struct proc *p; 128 { 129 struct vnode *ttyvp = cttyvp(p); 130 131 if (ttyvp == NULL) 132 return (EIO); 133 if (cmd == TIOCSCTTY) /* XXX */ 134 return (EINVAL); 135 if (cmd == TIOCNOTTY) { 136 if (!SESS_LEADER(p)) { 137 p->p_flag &= ~P_CONTROLT; 138 return (0); 139 } else 140 return (EINVAL); 141 } 142 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 143 } 144 145 /*ARGSUSED*/ 146 int 147 cttypoll(dev, events, p) 148 dev_t dev; 149 int events; 150 struct proc *p; 151 { 152 struct vnode *ttyvp = cttyvp(p); 153 154 if (ttyvp == NULL) 155 return (seltrue(dev, events, p)); 156 return (VOP_POLL(ttyvp, events, p)); 157 } 158