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 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 34 */ 35 36 /* 37 * Indirect driver for controlling tty. 38 */ 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/conf.h> 42 #include <sys/ioctl.h> 43 #include <sys/proc.h> 44 #include <sys/tty.h> 45 #include <sys/vnode.h> 46 #include <sys/file.h> 47 48 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 49 50 /*ARGSUSED*/ 51 int 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 int 83 cttyread(dev, uio, flag) 84 dev_t dev; 85 struct uio *uio; 86 int flag; 87 { 88 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 89 int error; 90 91 if (ttyvp == NULL) 92 return (EIO); 93 VOP_LOCK(ttyvp); 94 error = VOP_READ(ttyvp, uio, flag, NOCRED); 95 VOP_UNLOCK(ttyvp); 96 return (error); 97 } 98 99 /*ARGSUSED*/ 100 int 101 cttywrite(dev, uio, flag) 102 dev_t dev; 103 struct uio *uio; 104 int flag; 105 { 106 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 107 int error; 108 109 if (ttyvp == NULL) 110 return (EIO); 111 VOP_LOCK(ttyvp); 112 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 113 VOP_UNLOCK(ttyvp); 114 return (error); 115 } 116 117 /*ARGSUSED*/ 118 int 119 cttyioctl(dev, cmd, addr, flag, p) 120 dev_t dev; 121 int cmd; 122 caddr_t addr; 123 int flag; 124 struct proc *p; 125 { 126 struct vnode *ttyvp = cttyvp(p); 127 128 if (ttyvp == NULL) 129 return (EIO); 130 if (cmd == TIOCNOTTY) { 131 if (!SESS_LEADER(p)) { 132 p->p_flag &= ~P_CONTROLT; 133 return (0); 134 } else 135 return (EINVAL); 136 } 137 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 138 } 139 140 /*ARGSUSED*/ 141 int 142 cttyselect(dev, flag, p) 143 dev_t dev; 144 int flag; 145 struct proc *p; 146 { 147 struct vnode *ttyvp = cttyvp(p); 148 149 if (ttyvp == NULL) 150 return (1); /* try operation to get EOF/failure */ 151 return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p)); 152 } 153