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 * $FreeBSD: src/sys/kern/tty_tty.c,v 1.30 1999/09/25 18:24:24 phk Exp $ 35 * $DragonFly: src/sys/kern/tty_tty.c,v 1.9 2004/05/19 22:52:58 dillon Exp $ 36 */ 37 38 /* 39 * Indirect driver for controlling tty. 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/conf.h> 45 #include <sys/lock.h> 46 #include <sys/proc.h> 47 #include <sys/ttycom.h> 48 #include <sys/vnode.h> 49 #include <sys/kernel.h> 50 51 static d_open_t cttyopen; 52 static d_close_t cttyclose; 53 static d_read_t cttyread; 54 static d_write_t cttywrite; 55 static d_ioctl_t cttyioctl; 56 static d_poll_t cttypoll; 57 58 #define CDEV_MAJOR 1 59 /* Don't make this static, since fdesc_vnops uses it. */ 60 struct cdevsw ctty_cdevsw = { 61 /* name */ "ctty", 62 /* maj */ CDEV_MAJOR, 63 /* flags */ D_TTY, 64 /* port */ NULL, 65 /* clone */ NULL, 66 67 /* open */ cttyopen, 68 /* close */ cttyclose, 69 /* read */ cttyread, 70 /* write */ cttywrite, 71 /* ioctl */ cttyioctl, 72 /* poll */ cttypoll, 73 /* mmap */ nommap, 74 /* strategy */ nostrategy, 75 /* dump */ nodump, 76 /* psize */ nopsize 77 }; 78 79 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 80 81 /*ARGSUSED*/ 82 static int 83 cttyopen(dev_t dev, int flag, int mode, struct thread *td) 84 { 85 struct proc *p = td->td_proc; 86 struct vnode *ttyvp; 87 int error; 88 89 KKASSERT(p); 90 ttyvp = cttyvp(p); 91 if (ttyvp) { 92 vn_lock(ttyvp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 93 error = VOP_OPEN(ttyvp, flag, NOCRED, td); 94 VOP_UNLOCK(ttyvp, NULL, 0, td); 95 } else { 96 error = ENXIO; 97 } 98 return (error); 99 } 100 101 static int 102 cttyclose(dev_t dev, int fflag, int devtype, struct thread *td) 103 { 104 struct proc *p = td->td_proc; 105 struct vnode *ttyvp; 106 int error; 107 108 KKASSERT(p); 109 ttyvp = cttyvp(p); 110 if (ttyvp == NULL) 111 error = EIO; 112 else 113 error = VOP_CLOSE(ttyvp, fflag, td); 114 return(error); 115 } 116 117 /*ARGSUSED*/ 118 static int 119 cttyread(dev, uio, flag) 120 dev_t dev; 121 struct uio *uio; 122 int flag; 123 { 124 struct thread *td = uio->uio_td; 125 struct proc *p = td->td_proc; 126 struct vnode *ttyvp; 127 int error; 128 129 KKASSERT(p); 130 ttyvp = cttyvp(p); 131 if (ttyvp == NULL) 132 return (EIO); 133 vn_lock(ttyvp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 134 error = VOP_READ(ttyvp, uio, flag, NOCRED); 135 VOP_UNLOCK(ttyvp, NULL, 0, td); 136 return (error); 137 } 138 139 /*ARGSUSED*/ 140 static int 141 cttywrite(dev, uio, flag) 142 dev_t dev; 143 struct uio *uio; 144 int flag; 145 { 146 struct thread *td = uio->uio_td; 147 struct proc *p = td->td_proc; 148 struct vnode *ttyvp; 149 int error; 150 151 KKASSERT(p); 152 ttyvp = cttyvp(p); 153 if (ttyvp == NULL) 154 return (EIO); 155 vn_lock(ttyvp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 156 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 157 VOP_UNLOCK(ttyvp, NULL, 0, td); 158 return (error); 159 } 160 161 /*ARGSUSED*/ 162 static int 163 cttyioctl(dev, cmd, addr, flag, td) 164 dev_t dev; 165 u_long cmd; 166 caddr_t addr; 167 int flag; 168 struct thread *td; 169 { 170 struct vnode *ttyvp; 171 struct proc *p = td->td_proc; 172 173 KKASSERT(p); 174 ttyvp = cttyvp(p); 175 if (ttyvp == NULL) 176 return (EIO); 177 if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */ 178 return EINVAL; /* to controlling tty -- infinite recursion */ 179 if (cmd == TIOCNOTTY) { 180 if (!SESS_LEADER(p)) { 181 p->p_flag &= ~P_CONTROLT; 182 return (0); 183 } else 184 return (EINVAL); 185 } 186 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, td)); 187 } 188 189 /*ARGSUSED*/ 190 static int 191 cttypoll(dev_t dev, int events, struct thread *td) 192 { 193 struct vnode *ttyvp; 194 struct proc *p = td->td_proc; 195 196 KKASSERT(p); 197 ttyvp = cttyvp(p); 198 if (ttyvp == NULL) 199 /* try operation to get EOF/failure */ 200 return (seltrue(dev, events, td)); 201 return (VOP_POLL(ttyvp, events, p->p_ucred, td)); 202 } 203 204 static void ctty_drvinit (void *unused); 205 static void 206 ctty_drvinit(unused) 207 void *unused; 208 { 209 cdevsw_add(&ctty_cdevsw, 0, 0); 210 make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "tty"); 211 } 212 213 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL) 214