tty_tty.c revision 171186
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 171186 2007-07-03 17:46:37Z kib $"); 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> 34171186Skib#include <sys/sx.h> 35109524Sphk#include <sys/vnode.h> 36109524Sphk 37171186Skib#include <fs/devfs/devfs.h> 38171186Skib#include <fs/devfs/devfs_int.h> 39171186Skib 40109524Sphkstatic d_open_t cttyopen; 41109524Sphk 42109524Sphkstatic struct cdevsw ctty_cdevsw = { 43126080Sphk .d_version = D_VERSION, 44111815Sphk .d_open = cttyopen, 45111815Sphk .d_name = "ctty", 46126080Sphk .d_flags = D_TTY | D_NEEDGIANT, 47109524Sphk}; 48109524Sphk 49130585Sphkstatic struct cdev *ctty; 50109524Sphk 51109524Sphkstatic int 52130585Sphkcttyopen(struct cdev *dev, int flag, int mode, struct thread *td) 53109524Sphk{ 54109524Sphk 55109524Sphk return (ENXIO); 56109524Sphk} 57109524Sphk 58109524Sphkstatic void 59148868Srwatsonctty_clone(void *arg, struct ucred *cred, char *name, int namelen, 60148868Srwatson struct cdev **dev) 61109524Sphk{ 62109524Sphk 63130640Sphk if (*dev != NULL) 64109524Sphk return; 65109524Sphk if (strcmp(name, "tty")) 66109524Sphk return; 67171186Skib sx_sunlock(&clone_drain_lock); 68171186Skib mtx_lock(&Giant); 69171186Skib sx_slock(&proctree_lock); 70171186Skib sx_slock(&clone_drain_lock); 71171186Skib dev_lock(); 72109940Sphk if (!(curthread->td_proc->p_flag & P_CONTROLT)) 73109940Sphk *dev = ctty; 74109940Sphk else if (curthread->td_proc->p_session->s_ttyvp == NULL) 75109940Sphk *dev = ctty; 76162573Smbr else if (curthread->td_proc->p_session->s_ttyvp->v_type == VBAD || 77162573Smbr curthread->td_proc->p_session->s_ttyvp->v_rdev == NULL) { 78162573Smbr /* e.g. s_ttyvp was revoked */ 79162705Smbr *dev = ctty; 80162573Smbr } else 81109524Sphk *dev = curthread->td_proc->p_session->s_ttyvp->v_rdev; 82171186Skib dev_refl(*dev); 83171186Skib dev_unlock(); 84171186Skib sx_sunlock(&proctree_lock); 85171186Skib mtx_unlock(&Giant); 86109524Sphk} 87109524Sphk 88109524Sphkstatic void 89109524Sphkctty_drvinit(void *unused) 90109524Sphk{ 91109524Sphk 92109524Sphk EVENTHANDLER_REGISTER(dev_clone, ctty_clone, 0, 1000); 93109524Sphk ctty = make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "ctty"); 94109524Sphk} 95109524Sphk 96142709SphkSYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,ctty_drvinit,NULL) 97