tty_tty.c revision 162705
11541Srgrimes/*- 2109524Sphk * Copyright (c) 2003 Poul-Henning Kamp. All rights reserved. 3109524Sphk * 4109524Sphk * Redistribution and use in source and binary forms, with or without 5109524Sphk * modification, are permitted provided that the following conditions 6109524Sphk * are met: 7109524Sphk * 1. Redistributions of source code must retain the above copyright 8109524Sphk * notice, this list of conditions and the following disclaimer. 9109524Sphk * 2. Redistributions in binary form must reproduce the above copyright 10109524Sphk * notice, this list of conditions and the following disclaimer in the 11109524Sphk * documentation and/or other materials provided with the distribution. 12109524Sphk * 13109524Sphk * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14109524Sphk * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15109524Sphk * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16109524Sphk * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17109524Sphk * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18109524Sphk * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19109524Sphk * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20109524Sphk * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21109524Sphk * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22109524Sphk * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23109524Sphk * SUCH DAMAGE. 24109524Sphk */ 25109524Sphk 26116182Sobrien#include <sys/cdefs.h> 27116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/tty_tty.c 162705 2006-09-27 16:41:15Z mbr $"); 28116182Sobrien 29109524Sphk#include <sys/param.h> 30109524Sphk#include <sys/systm.h> 31109524Sphk#include <sys/conf.h> 32109524Sphk#include <sys/kernel.h> 33109524Sphk#include <sys/proc.h> 34109524Sphk#include <sys/vnode.h> 35109524Sphk 36109524Sphkstatic d_open_t cttyopen; 37109524Sphk 38109524Sphkstatic struct cdevsw ctty_cdevsw = { 39126080Sphk .d_version = D_VERSION, 40111815Sphk .d_open = cttyopen, 41111815Sphk .d_name = "ctty", 42126080Sphk .d_flags = D_TTY | D_NEEDGIANT, 43109524Sphk}; 44109524Sphk 45130585Sphkstatic struct cdev *ctty; 46109524Sphk 47109524Sphkstatic int 48130585Sphkcttyopen(struct cdev *dev, int flag, int mode, struct thread *td) 49109524Sphk{ 50109524Sphk 51109524Sphk return (ENXIO); 52109524Sphk} 53109524Sphk 54109524Sphkstatic void 55148868Srwatsonctty_clone(void *arg, struct ucred *cred, char *name, int namelen, 56148868Srwatson struct cdev **dev) 57109524Sphk{ 58109524Sphk 59130640Sphk if (*dev != NULL) 60109524Sphk return; 61109524Sphk if (strcmp(name, "tty")) 62109524Sphk return; 63109940Sphk if (!(curthread->td_proc->p_flag & P_CONTROLT)) 64109940Sphk *dev = ctty; 65109940Sphk else if (curthread->td_proc->p_session->s_ttyvp == NULL) 66109940Sphk *dev = ctty; 67162573Smbr else if (curthread->td_proc->p_session->s_ttyvp->v_type == VBAD || 68162573Smbr curthread->td_proc->p_session->s_ttyvp->v_rdev == NULL) { 69162573Smbr /* e.g. s_ttyvp was revoked */ 70162705Smbr *dev = ctty; 71162573Smbr } else 72109524Sphk *dev = curthread->td_proc->p_session->s_ttyvp->v_rdev; 73144389Sphk dev_ref(*dev); 74109524Sphk} 75109524Sphk 76109524Sphkstatic void 77109524Sphkctty_drvinit(void *unused) 78109524Sphk{ 79109524Sphk 80109524Sphk EVENTHANDLER_REGISTER(dev_clone, ctty_clone, 0, 1000); 81109524Sphk ctty = make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "ctty"); 82109524Sphk} 83109524Sphk 84142709SphkSYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,ctty_drvinit,NULL) 85