1 /*- 2 * Copyright (c) 2003 Poul-Henning Kamp. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 * $FreeBSD$ 26 */ 27 28 #include <sys/param.h> 29 #include <sys/systm.h> 30 #include <sys/conf.h> 31 #include <sys/kernel.h> 32 #include <sys/proc.h> 33 #include <sys/vnode.h> 34 35 static d_open_t cttyopen; 36 37 #define CDEV_MAJOR 1 38 39 static struct cdevsw ctty_cdevsw = { 40 /* open */ cttyopen, 41 /* close */ nullclose, 42 /* read */ noread, 43 /* write */ nowrite, 44 /* ioctl */ noioctl, 45 /* poll */ nopoll, 46 /* mmap */ nommap, 47 /* strategy */ nostrategy, 48 /* name */ "ctty", 49 /* maj */ CDEV_MAJOR, 50 /* dump */ nodump, 51 /* psize */ nopsize, 52 /* flags */ D_TTY, 53 }; 54 55 static dev_t ctty; 56 57 static int 58 cttyopen(dev_t dev, int flag, int mode, struct thread *td) 59 { 60 61 return (ENXIO); 62 } 63 64 static void 65 ctty_clone(void *arg, char *name, int namelen, dev_t *dev) 66 { 67 68 if (*dev != NODEV) 69 return; 70 if (strcmp(name, "tty")) 71 return; 72 if (!(curthread->td_proc->p_flag & P_CONTROLT)) 73 *dev = ctty; 74 else if (curthread->td_proc->p_session->s_ttyvp == NULL) 75 *dev = ctty; 76 else 77 *dev = curthread->td_proc->p_session->s_ttyvp->v_rdev; 78 } 79 80 static void 81 ctty_drvinit(void *unused) 82 { 83 84 EVENTHANDLER_REGISTER(dev_clone, ctty_clone, 0, 1000); 85 ctty = make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "ctty"); 86 } 87 88 SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL) 89