diff options
Diffstat (limited to 'sys/kern/tty_tty.c')
| -rw-r--r-- | sys/kern/tty_tty.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/sys/kern/tty_tty.c b/sys/kern/tty_tty.c new file mode 100644 index 0000000..2d15c70 --- /dev/null +++ b/sys/kern/tty_tty.c @@ -0,0 +1,195 @@ +/*- + * 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/lock.h> +#include <sys/proc.h> +#include <sys/ttycom.h> +#include <sys/vnode.h> +#include <sys/kernel.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 +/* Don't make this static, since fdesc_vnops uses it. */ +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, + /* bmaj */ -1 +}; + +#define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) + +/*ARGSUSED*/ +static int +cttyopen(dev, flag, mode, p) + dev_t dev; + int flag, mode; + struct proc *p; +{ + struct vnode *ttyvp = cttyvp(p); + int error; + + if (ttyvp == NULL) + return (ENXIO); + vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); +#ifdef PARANOID + /* + * Since group is tty and mode is 620 on most terminal lines + * and since sessions protect terminals from processes outside + * your session, this check is probably no longer necessary. + * Since it inhibits setuid root programs that later switch + * to another user from accessing /dev/tty, we have decided + * to delete this test. (mckusick 5/93) + */ + error = VOP_ACCESS(ttyvp, + (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); + if (!error) +#endif /* PARANOID */ + error = VOP_OPEN(ttyvp, flag, NOCRED, p); + VOP_UNLOCK(ttyvp, 0, p); + return (error); +} + +/*ARGSUSED*/ +static int +cttyread(dev, uio, flag) + dev_t dev; + struct uio *uio; + int flag; +{ + struct proc *p = uio->uio_procp; + register struct vnode *ttyvp = cttyvp(p); + int error; + + if (ttyvp == NULL) + return (EIO); + vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); + error = VOP_READ(ttyvp, uio, flag, NOCRED); + VOP_UNLOCK(ttyvp, 0, p); + return (error); +} + +/*ARGSUSED*/ +static int +cttywrite(dev, uio, flag) + dev_t dev; + struct uio *uio; + int flag; +{ + struct proc *p = uio->uio_procp; + struct vnode *ttyvp = cttyvp(uio->uio_procp); + int error; + + if (ttyvp == NULL) + return (EIO); + vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p); + error = VOP_WRITE(ttyvp, uio, flag, NOCRED); + VOP_UNLOCK(ttyvp, 0, p); + return (error); +} + +/*ARGSUSED*/ +static int +cttyioctl(dev, cmd, addr, flag, p) + dev_t dev; + u_long cmd; + caddr_t addr; + int flag; + struct proc *p; +{ + struct vnode *ttyvp = cttyvp(p); + + 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) { + if (!SESS_LEADER(p)) { + p->p_flag &= ~P_CONTROLT; + return (0); + } else + return (EINVAL); + } + return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); +} + +/*ARGSUSED*/ +static int +cttypoll(dev, events, p) + dev_t dev; + int events; + struct proc *p; +{ + struct vnode *ttyvp = cttyvp(p); + + if (ttyvp == NULL) + /* try operation to get EOF/failure */ + return (seltrue(dev, events, p)); + return (VOP_POLL(ttyvp, events, p->p_ucred, p)); +} + +static void ctty_drvinit __P((void *unused)); +static void +ctty_drvinit(unused) + void *unused; +{ + + make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "tty"); +} + +SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL) |
