1 /* $NetBSD: tty_tty.c,v 1.17 2001/11/12 15:25:30 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1982, 1986, 1991, 1993, 1995 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 42 #include <sys/cdefs.h> 43 __KERNEL_RCSID(0, "$NetBSD: tty_tty.c,v 1.17 2001/11/12 15:25:30 lukem Exp $"); 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/ioctl.h> 48 #include <sys/proc.h> 49 #include <sys/tty.h> 50 #include <sys/vnode.h> 51 #include <sys/file.h> 52 #include <sys/conf.h> 53 54 55 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 56 57 /*ARGSUSED*/ 58 int 59 cttyopen(dev, flag, mode, p) 60 dev_t dev; 61 int flag, mode; 62 struct proc *p; 63 { 64 struct vnode *ttyvp = cttyvp(p); 65 int error; 66 67 if (ttyvp == NULL) 68 return (ENXIO); 69 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); 70 #ifdef PARANOID 71 /* 72 * Since group is tty and mode is 620 on most terminal lines 73 * and since sessions protect terminals from processes outside 74 * your session, this check is probably no longer necessary. 75 * Since it inhibits setuid root programs that later switch 76 * to another user from accessing /dev/tty, we have decided 77 * to delete this test. (mckusick 5/93) 78 */ 79 error = VOP_ACCESS(ttyvp, 80 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 81 if (!error) 82 #endif /* PARANOID */ 83 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 84 VOP_UNLOCK(ttyvp, 0); 85 return (error); 86 } 87 88 /*ARGSUSED*/ 89 int 90 cttyread(dev, uio, flag) 91 dev_t dev; 92 struct uio *uio; 93 int flag; 94 { 95 struct vnode *ttyvp = cttyvp(uio->uio_procp); 96 int error; 97 98 if (ttyvp == NULL) 99 return (EIO); 100 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); 101 error = VOP_READ(ttyvp, uio, flag, NOCRED); 102 VOP_UNLOCK(ttyvp, 0); 103 return (error); 104 } 105 106 /*ARGSUSED*/ 107 int 108 cttywrite(dev, uio, flag) 109 dev_t dev; 110 struct uio *uio; 111 int flag; 112 { 113 struct vnode *ttyvp = cttyvp(uio->uio_procp); 114 int error; 115 116 if (ttyvp == NULL) 117 return (EIO); 118 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY); 119 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 120 VOP_UNLOCK(ttyvp, 0); 121 return (error); 122 } 123 124 /*ARGSUSED*/ 125 int 126 cttyioctl(dev, cmd, addr, flag, p) 127 dev_t dev; 128 u_long cmd; 129 caddr_t addr; 130 int flag; 131 struct proc *p; 132 { 133 struct vnode *ttyvp = cttyvp(p); 134 135 if (ttyvp == NULL) 136 return (EIO); 137 if (cmd == TIOCSCTTY) /* XXX */ 138 return (EINVAL); 139 if (cmd == TIOCNOTTY) { 140 if (!SESS_LEADER(p)) { 141 p->p_flag &= ~P_CONTROLT; 142 return (0); 143 } else 144 return (EINVAL); 145 } 146 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 147 } 148 149 /*ARGSUSED*/ 150 int 151 cttypoll(dev, events, p) 152 dev_t dev; 153 int events; 154 struct proc *p; 155 { 156 struct vnode *ttyvp = cttyvp(p); 157 158 if (ttyvp == NULL) 159 return (seltrue(dev, events, p)); 160 return (VOP_POLL(ttyvp, events, p)); 161 } 162