1 /* $OpenBSD: tty_tty.c,v 1.10 2007/03/15 10:22:30 art Exp $ */ 2 /* $NetBSD: tty_tty.c,v 1.13 1996/03/30 22:24:46 christos Exp $ */ 3 4 /*- 5 * Copyright (c) 1982, 1986, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 33 */ 34 35 /* 36 * Indirect driver for controlling tty. 37 */ 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/ioctl.h> 41 #include <sys/proc.h> 42 #include <sys/tty.h> 43 #include <sys/vnode.h> 44 #include <sys/file.h> 45 #include <sys/conf.h> 46 47 48 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 49 50 /*ARGSUSED*/ 51 int 52 cttyopen(dev_t dev, int flag, int mode, struct proc *p) 53 { 54 struct vnode *ttyvp = cttyvp(p); 55 int error; 56 57 if (ttyvp == NULL) 58 return (ENXIO); 59 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); 60 #ifdef PARANOID 61 /* 62 * Since group is tty and mode is 620 on most terminal lines 63 * and since sessions protect terminals from processes outside 64 * your session, this check is probably no longer necessary. 65 * Since it inhibits setuid root programs that later switch 66 * to another user from accessing /dev/tty, we have decided 67 * to delete this test. (mckusick 5/93) 68 */ 69 error = VOP_ACCESS(ttyvp, 70 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 71 if (!error) 72 #endif /* PARANOID */ 73 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 74 VOP_UNLOCK(ttyvp, 0, p); 75 return (error); 76 } 77 78 /*ARGSUSED*/ 79 int 80 cttyread(dev_t dev, struct uio *uio, int flag) 81 { 82 struct proc *p = uio->uio_procp; 83 struct vnode *ttyvp = cttyvp(uio->uio_procp); 84 int error; 85 86 if (ttyvp == NULL) 87 return (EIO); 88 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); 89 error = VOP_READ(ttyvp, uio, flag, NOCRED); 90 VOP_UNLOCK(ttyvp, 0, p); 91 return (error); 92 } 93 94 /*ARGSUSED*/ 95 int 96 cttywrite(dev_t dev, struct uio *uio, int flag) 97 { 98 struct proc *p = uio->uio_procp; 99 struct vnode *ttyvp = cttyvp(uio->uio_procp); 100 int error; 101 102 if (ttyvp == NULL) 103 return (EIO); 104 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); 105 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 106 VOP_UNLOCK(ttyvp, 0, p); 107 return (error); 108 } 109 110 /*ARGSUSED*/ 111 int 112 cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p) 113 { 114 struct vnode *ttyvp = cttyvp(p); 115 116 if (ttyvp == NULL) 117 return (EIO); 118 if (cmd == TIOCSCTTY) /* XXX */ 119 return (EINVAL); 120 if (cmd == TIOCNOTTY) { 121 if (!SESS_LEADER(p)) { 122 atomic_clearbits_int(&p->p_flag, P_CONTROLT); 123 return (0); 124 } else 125 return (EINVAL); 126 } 127 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 128 } 129 130 /*ARGSUSED*/ 131 int 132 cttypoll(dev_t dev, int events, struct proc *p) 133 { 134 struct vnode *ttyvp = cttyvp(p); 135 136 if (ttyvp == NULL) /* try operation to get EOF/failure */ 137 return (seltrue(dev, events, p)); 138 return (VOP_POLL(ttyvp, events, p)); 139 } 140