1 /* $OpenBSD: tty_tty.c,v 1.11 2010/07/26 01:56:27 guenther 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) \ 49 ((p)->p_p->ps_flags & PS_CONTROLT ? \ 50 (p)->p_p->ps_session->s_ttyvp : NULL) 51 52 /*ARGSUSED*/ 53 int 54 cttyopen(dev_t dev, int flag, int mode, struct proc *p) 55 { 56 struct vnode *ttyvp = cttyvp(p); 57 int error; 58 59 if (ttyvp == NULL) 60 return (ENXIO); 61 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); 62 #ifdef PARANOID 63 /* 64 * Since group is tty and mode is 620 on most terminal lines 65 * and since sessions protect terminals from processes outside 66 * your session, this check is probably no longer necessary. 67 * Since it inhibits setuid root programs that later switch 68 * to another user from accessing /dev/tty, we have decided 69 * to delete this test. (mckusick 5/93) 70 */ 71 error = VOP_ACCESS(ttyvp, 72 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 73 if (!error) 74 #endif /* PARANOID */ 75 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 76 VOP_UNLOCK(ttyvp, 0, p); 77 return (error); 78 } 79 80 /*ARGSUSED*/ 81 int 82 cttyread(dev_t dev, struct uio *uio, int flag) 83 { 84 struct proc *p = uio->uio_procp; 85 struct vnode *ttyvp = cttyvp(uio->uio_procp); 86 int error; 87 88 if (ttyvp == NULL) 89 return (EIO); 90 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); 91 error = VOP_READ(ttyvp, uio, flag, NOCRED); 92 VOP_UNLOCK(ttyvp, 0, p); 93 return (error); 94 } 95 96 /*ARGSUSED*/ 97 int 98 cttywrite(dev_t dev, struct uio *uio, int flag) 99 { 100 struct proc *p = uio->uio_procp; 101 struct vnode *ttyvp = cttyvp(uio->uio_procp); 102 int error; 103 104 if (ttyvp == NULL) 105 return (EIO); 106 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); 107 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 108 VOP_UNLOCK(ttyvp, 0, p); 109 return (error); 110 } 111 112 /*ARGSUSED*/ 113 int 114 cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p) 115 { 116 struct vnode *ttyvp = cttyvp(p); 117 118 if (ttyvp == NULL) 119 return (EIO); 120 if (cmd == TIOCSCTTY) /* XXX */ 121 return (EINVAL); 122 if (cmd == TIOCNOTTY) { 123 if (!SESS_LEADER(p->p_p)) { 124 atomic_clearbits_int(&p->p_p->ps_flags, PS_CONTROLT); 125 return (0); 126 } else 127 return (EINVAL); 128 } 129 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 130 } 131 132 /*ARGSUSED*/ 133 int 134 cttypoll(dev_t dev, int events, struct proc *p) 135 { 136 struct vnode *ttyvp = cttyvp(p); 137 138 if (ttyvp == NULL) /* try operation to get EOF/failure */ 139 return (seltrue(dev, events, p)); 140 return (VOP_POLL(ttyvp, events, p)); 141 } 142