diff options
Diffstat (limited to 'sys/kern/tty_tty.c')
| -rw-r--r-- | sys/kern/tty_tty.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/sys/kern/tty_tty.c b/sys/kern/tty_tty.c new file mode 100644 index 0000000..e1e03bd --- /dev/null +++ b/sys/kern/tty_tty.c @@ -0,0 +1,252 @@ +/*- + * Copyright (c) 1982, 1986, 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 + * $FreeBSD$ + */ + +/* + * Indirect driver for controlling tty. + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/conf.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/sx.h> +#include <sys/proc.h> +#include <sys/ttycom.h> +#include <sys/vnode.h> + +static d_open_t cttyopen; +static d_read_t cttyread; +static d_write_t cttywrite; +static d_ioctl_t cttyioctl; +static d_poll_t cttypoll; + +#define CDEV_MAJOR 1 + +static struct cdevsw ctty_cdevsw = { + /* open */ cttyopen, + /* close */ nullclose, + /* read */ cttyread, + /* write */ cttywrite, + /* ioctl */ cttyioctl, + /* poll */ cttypoll, + /* mmap */ nommap, + /* strategy */ nostrategy, + /* name */ "ctty", + /* maj */ CDEV_MAJOR, + /* dump */ nodump, + /* psize */ nopsize, + /* flags */ D_TTY, +}; + +#define cttyvp(td) ((td)->td_proc->p_flag & P_CONTROLT ? (td)->td_proc->p_session->s_ttyvp : NULL) + +/*ARGSUSED*/ +static int +cttyopen(dev, flag, mode, td) + dev_t dev; + int flag, mode; + struct thread *td; +{ + struct vnode *ttyvp; + int error; + + PROC_LOCK(td->td_proc); + SESS_LOCK(td->td_proc->p_session); + ttyvp = cttyvp(td); + SESS_UNLOCK(td->td_proc->p_session); + PROC_UNLOCK(td->td_proc); + + if (ttyvp == NULL) + return (ENXIO); + vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td); + error = VOP_OPEN(ttyvp, flag, NOCRED, td); + VOP_UNLOCK(ttyvp, 0, td); + return (error); +} + +/*ARGSUSED*/ +static int +cttyread(dev, uio, flag) + dev_t dev; + struct uio *uio; + int flag; +{ + struct thread *td = uio->uio_td; + register struct vnode *ttyvp; + int error; + + PROC_LOCK(td->td_proc); + SESS_LOCK(td->td_proc->p_session); + ttyvp = cttyvp(td); + SESS_UNLOCK(td->td_proc->p_session); + PROC_UNLOCK(td->td_proc); + + if (ttyvp == NULL) + return (EIO); + vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td); + error = VOP_READ(ttyvp, uio, flag, NOCRED); + VOP_UNLOCK(ttyvp, 0, td); + return (error); +} + +/*ARGSUSED*/ +static int +cttywrite(dev, uio, flag) + dev_t dev; + struct uio *uio; + int flag; +{ + struct thread *td = uio->uio_td; + struct vnode *ttyvp; + struct mount *mp; + int error; + + PROC_LOCK(td->td_proc); + SESS_LOCK(td->td_proc->p_session); + ttyvp = cttyvp(td); + SESS_UNLOCK(td->td_proc->p_session); + PROC_UNLOCK(td->td_proc); + + if (ttyvp == NULL) + return (EIO); + mp = NULL; + if (ttyvp->v_type != VCHR && + (error = vn_start_write(ttyvp, &mp, V_WAIT | PCATCH)) != 0) + return (error); + vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, td); + error = VOP_WRITE(ttyvp, uio, flag, NOCRED); + VOP_UNLOCK(ttyvp, 0, td); + vn_finished_write(mp); + return (error); +} + +/*ARGSUSED*/ +static int +cttyioctl(dev, cmd, addr, flag, td) + dev_t dev; + u_long cmd; + caddr_t addr; + int flag; + struct thread *td; +{ + struct vnode *ttyvp; + int error; + + PROC_LOCK(td->td_proc); + SESS_LOCK(td->td_proc->p_session); + ttyvp = cttyvp(td); + SESS_UNLOCK(td->td_proc->p_session); + PROC_UNLOCK(td->td_proc); + + if (ttyvp == NULL) + return (EIO); + if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */ + return EINVAL; /* to controlling tty -- infinite recursion */ + if (cmd == TIOCNOTTY) { + PROC_LOCK(td->td_proc); + SESS_LOCK(td->td_proc->p_session); + error = 0; + if (!SESS_LEADER(td->td_proc)) + td->td_proc->p_flag &= ~P_CONTROLT; + else + error = EINVAL; + SESS_UNLOCK(td->td_proc->p_session); + PROC_UNLOCK(td->td_proc); + return (error); + } + return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, td)); +} + +/*ARGSUSED*/ +static int +cttypoll(dev, events, td) + dev_t dev; + int events; + struct thread *td; +{ + struct vnode *ttyvp; + + PROC_LOCK(td->td_proc); + SESS_LOCK(td->td_proc->p_session); + ttyvp = cttyvp(td); + SESS_UNLOCK(td->td_proc->p_session); + PROC_UNLOCK(td->td_proc); + + if (ttyvp == NULL) + /* try operation to get EOF/failure */ + return (seltrue(dev, events, td)); + return (VOP_POLL(ttyvp, events, td->td_ucred, td)); +} + +static void ctty_clone(void *arg, char *name, int namelen, dev_t *dev); + +static dev_t ctty; + +static void +ctty_clone(void *arg, char *name, int namelen, dev_t *dev) +{ + struct vnode *vp; + + if (*dev != NODEV) + return; + if (strcmp(name, "tty")) + return; + vp = cttyvp(curthread); + if (vp == NULL) { + if (ctty) + *dev = ctty; + } else + *dev = vp->v_rdev; +} + + +static void ctty_drvinit(void *unused); +static void +ctty_drvinit(unused) + void *unused; +{ + + if (devfs_present) { + EVENTHANDLER_REGISTER(dev_clone, ctty_clone, 0, 1000); + ctty = make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "ctty"); + } else { + make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "tty"); + } +} + +SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL) |
