[apple/xnu.git] / bsd / kern / tty_tty.c

/*
 * Copyright (c) 1997-2012 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*-
 * 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
 */

/*
 * Indirect driver for controlling tty.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/proc_internal.h>
#include <sys/tty.h>
#include <sys/vnode_internal.h>
#include <sys/file_internal.h>
#include <sys/kauth.h>

/* Forward declarations for cdevsw[] entry */
/* XXX we should consider making these static */
int cttyopen(dev_t dev, int flag, int mode, proc_t p);
int cttyclose(dev_t dev, int flag, int mode, proc_t p);
int cttyread(dev_t dev, struct uio *uio, int flag);
int cttywrite(dev_t dev, struct uio *uio, int flag);
int cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, proc_t p);
int cttyselect(dev_t dev, int flag, void* wql, proc_t p);
static vnode_t cttyvp(proc_t p);

int
cttyopen(dev_t dev, int flag, __unused int mode, proc_t p)
{
	vnode_t ttyvp;
	int error;

	/*
	 * A little hack--this device, used by many processes,
	 * does an open on another device, which can cause unhappiness
	 * if the second-level open blocks indefinitely (e.g. if the
	 * master side has hung up).  This driver doesn't care
	 * about serializing opens and closes, so drop the lock.
	 */
	devsw_unlock(dev, S_IFCHR);

	if ((ttyvp = cttyvp(p)) == NULL) {
		error = ENXIO;
	} else {
		struct vfs_context context;

		context.vc_thread = current_thread();
		context.vc_ucred = kauth_cred_proc_ref(p);

		error = VNOP_OPEN(ttyvp, flag, &context);

		kauth_cred_unref(&context.vc_ucred);
		vnode_put(ttyvp);
	}

	devsw_lock(dev, S_IFCHR);
	return (error);
}

/*
 * This driver is marked D_TRACKCLOSE and so gets a close
 * for every open so that ttyvp->v_specinfo->si_count can be kept sane.
 */
int
cttyclose(dev_t dev, int flag, __unused int mode, proc_t p)
{
	vnode_t ttyvp;
	int error;

	/* See locking commentary above. */

	devsw_unlock(dev, S_IFCHR);

	if ((ttyvp = cttyvp(p)) == NULL) {
		error = ENXIO;
	} else {
		struct vfs_context context;

		context.vc_thread = current_thread();
		context.vc_ucred = kauth_cred_proc_ref(p);

		error = VNOP_CLOSE(ttyvp, flag, &context);

		kauth_cred_unref(&context.vc_ucred);
		vnode_put(ttyvp);
	}

	devsw_lock(dev, S_IFCHR);
	return (error);
}

int
cttyread(__unused dev_t dev, struct uio *uio, int flag)
{
	vnode_t ttyvp = cttyvp(current_proc());
	struct vfs_context context;
	int error;

	if (ttyvp == NULL)
		return (EIO);

	context.vc_thread = current_thread();
	context.vc_ucred = NOCRED;

	error = VNOP_READ(ttyvp, uio, flag, &context);
	vnode_put(ttyvp);

	return (error);
}

int
cttywrite(__unused dev_t dev, struct uio *uio, int flag)
{
	vnode_t ttyvp = cttyvp(current_proc());
	struct vfs_context context;
	int error;

	if (ttyvp == NULL)
		return (EIO);

	context.vc_thread = current_thread();
	context.vc_ucred = NOCRED;

	error = VNOP_WRITE(ttyvp, uio, flag, &context);
	vnode_put(ttyvp);

	return (error);
}

int
cttyioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flag, proc_t p)
{
	vnode_t ttyvp = cttyvp(current_proc());
	struct vfs_context context;
	struct session *sessp;
	int error = 0;

	if (ttyvp == NULL)
		return (EIO);
	if (cmd == TIOCSCTTY)  { /* don't allow controlling tty to be set    */
		error = EINVAL; /* to controlling tty -- infinite recursion */
		goto out;
	}
	if (cmd == TIOCNOTTY) {
		sessp = proc_session(p);
		if (!SESS_LEADER(p, sessp)) {
			OSBitAndAtomic(~((uint32_t)P_CONTROLT), &p->p_flag);
			if (sessp != SESSION_NULL)
				session_rele(sessp);
			error = 0;
			goto out;
		} else {
			if (sessp != SESSION_NULL)
				session_rele(sessp);
			error = EINVAL;
			goto out;
		}
	}
	context.vc_thread = current_thread();
	context.vc_ucred = NOCRED;

	error = VNOP_IOCTL(ttyvp, cmd, addr, flag, &context);
out:
	vnode_put(ttyvp);
	return (error);
}

int
cttyselect(__unused dev_t dev, int flag, void* wql, __unused proc_t p)
{
	vnode_t ttyvp = cttyvp(current_proc());
	struct vfs_context context;
	int error;

	context.vc_thread = current_thread();
	context.vc_ucred = NOCRED;

	if (ttyvp == NULL)
		return (1);	/* try operation to get EOF/failure */
	error = VNOP_SELECT(ttyvp, flag, FREAD|FWRITE, wql, &context);
	vnode_put(ttyvp);
	return (error);
}

/* This returns vnode with ioref */
static vnode_t
cttyvp(proc_t p)
{
	vnode_t vp;
	int vid;
	struct session *sessp;

	sessp = proc_session(p);

	session_lock(sessp);
	vp = (p->p_flag & P_CONTROLT ? sessp->s_ttyvp : NULLVP);
	vid = sessp->s_ttyvid;	
	session_unlock(sessp);

	session_rele(sessp);

	if (vp != NULLVP) {
		/* cannot get an IO reference, return NULLVP */
		if (vnode_getwithvid(vp, vid) != 0)
			vp = NULLVP;
	}
	return(vp);
}
Commit	Line	Data
1c79356b	1	/*
316670eb	2	* Copyright (c) 1997-2012 Apple Computer, Inc. All rights reserved.
5d5c5d0d	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b	27	*/
1c79356b A	28	/*-
	29	* Copyright (c) 1982, 1986, 1991, 1993
	30	* The Regents of the University of California. All rights reserved.
	31	*
	32	* Redistribution and use in source and binary forms, with or without
	33	* modification, are permitted provided that the following conditions
	34	* are met:
	35	* 1. Redistributions of source code must retain the above copyright
	36	* notice, this list of conditions and the following disclaimer.
	37	* 2. Redistributions in binary form must reproduce the above copyright
	38	* notice, this list of conditions and the following disclaimer in the
	39	* documentation and/or other materials provided with the distribution.
	40	* 3. All advertising materials mentioning features or use of this software
	41	* must display the following acknowledgement:
	42	* This product includes software developed by the University of
	43	* California, Berkeley and its contributors.
	44	* 4. Neither the name of the University nor the names of its contributors
	45	* may be used to endorse or promote products derived from this software
	46	* without specific prior written permission.
	47	*
	48	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	49	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	50	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	51	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	52	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	53	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	54	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	55	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	56	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	57	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	58	* SUCH DAMAGE.
	59	*
	60	* @(#)tty_tty.c 8.2 (Berkeley) 9/23/93
	61	*/
	62
	63	/*
	64	* Indirect driver for controlling tty.
	65	*/
	66	#include <sys/param.h>
	67	#include <sys/systm.h>
	68	#include <sys/conf.h>
	69	#include <sys/ioctl.h>
91447636	70	#include <sys/proc_internal.h>
1c79356b	71	#include <sys/tty.h>
91447636 A	72	#include <sys/vnode_internal.h>
91447636 A	73	#include <sys/file_internal.h>
2d21ac55	74	#include <sys/kauth.h>
91447636 A	75
	76	/* Forward declarations for cdevsw[] entry */
	77	/* XXX we should consider making these static */
2d21ac55	78	int cttyopen(dev_t dev, int flag, int mode, proc_t p);
316670eb	79	int cttyclose(dev_t dev, int flag, int mode, proc_t p);
91447636 A	80	int cttyread(dev_t dev, struct uio *uio, int flag);
91447636 A	81	int cttywrite(dev_t dev, struct uio *uio, int flag);
2d21ac55 A	82	int cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, proc_t p);
	83	int cttyselect(dev_t dev, int flag, void* wql, proc_t p);
	84	static vnode_t cttyvp(proc_t p);
1c79356b	85
1c79356b	86	int
6d2010ae	87	cttyopen(dev_t dev, int flag, __unused int mode, proc_t p)
1c79356b	88	{
316670eb	89	vnode_t ttyvp;
1c79356b A	90	int error;
1c79356b A	91
6d2010ae A	92	/*
6d2010ae A	93	* A little hack--this device, used by many processes,
316670eb A	94	* does an open on another device, which can cause unhappiness
	95	* if the second-level open blocks indefinitely (e.g. if the
	96	* master side has hung up). This driver doesn't care
	97	* about serializing opens and closes, so drop the lock.
6d2010ae A	98	*/
6d2010ae A	99	devsw_unlock(dev, S_IFCHR);
316670eb A	100
	101	if ((ttyvp = cttyvp(p)) == NULL) {
	102	error = ENXIO;
	103	} else {
	104	struct vfs_context context;
	105
	106	context.vc_thread = current_thread();
	107	context.vc_ucred = kauth_cred_proc_ref(p);
	108
	109	error = VNOP_OPEN(ttyvp, flag, &context);
	110
	111	kauth_cred_unref(&context.vc_ucred);
	112	vnode_put(ttyvp);
	113	}
	114
6d2010ae	115	devsw_lock(dev, S_IFCHR);
316670eb A	116	return (error);
316670eb A	117	}
6d2010ae	118
316670eb A	119	/*
	120	* This driver is marked D_TRACKCLOSE and so gets a close
	121	* for every open so that ttyvp->v_specinfo->si_count can be kept sane.
	122	*/
	123	int
	124	cttyclose(dev_t dev, int flag, __unused int mode, proc_t p)
	125	{
	126	vnode_t ttyvp;
	127	int error;
	128
	129	/* See locking commentary above. */
91447636	130
316670eb A	131	devsw_unlock(dev, S_IFCHR);
	132
	133	if ((ttyvp = cttyvp(p)) == NULL) {
	134	error = ENXIO;
	135	} else {
	136	struct vfs_context context;
	137
	138	context.vc_thread = current_thread();
	139	context.vc_ucred = kauth_cred_proc_ref(p);
	140
	141	error = VNOP_CLOSE(ttyvp, flag, &context);
	142
	143	kauth_cred_unref(&context.vc_ucred);
	144	vnode_put(ttyvp);
	145	}
	146
	147	devsw_lock(dev, S_IFCHR);
1c79356b A	148	return (error);
	149	}
	150
1c79356b	151	int
91447636	152	cttyread(__unused dev_t dev, struct uio *uio, int flag)
1c79356b	153	{
2d21ac55	154	vnode_t ttyvp = cttyvp(current_proc());
91447636	155	struct vfs_context context;
1c79356b A	156	int error;
	157
	158	if (ttyvp == NULL)
	159	return (EIO);
91447636	160
2d21ac55	161	context.vc_thread = current_thread();
91447636 A	162	context.vc_ucred = NOCRED;
	163
	164	error = VNOP_READ(ttyvp, uio, flag, &context);
2d21ac55	165	vnode_put(ttyvp);
91447636	166
1c79356b A	167	return (error);
	168	}
	169
1c79356b	170	int
91447636	171	cttywrite(__unused dev_t dev, struct uio *uio, int flag)
1c79356b	172	{
2d21ac55	173	vnode_t ttyvp = cttyvp(current_proc());
91447636	174	struct vfs_context context;
1c79356b A	175	int error;
	176
	177	if (ttyvp == NULL)
	178	return (EIO);
91447636	179
2d21ac55	180	context.vc_thread = current_thread();
91447636 A	181	context.vc_ucred = NOCRED;
	182
	183	error = VNOP_WRITE(ttyvp, uio, flag, &context);
2d21ac55	184	vnode_put(ttyvp);
91447636	185
1c79356b A	186	return (error);
	187	}
	188
1c79356b	189	int
2d21ac55	190	cttyioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flag, proc_t p)
1c79356b	191	{
2d21ac55	192	vnode_t ttyvp = cttyvp(current_proc());
91447636	193	struct vfs_context context;
2d21ac55 A	194	struct session *sessp;
2d21ac55 A	195	int error = 0;
1c79356b A	196
	197	if (ttyvp == NULL)
	198	return (EIO);
2d21ac55 A	199	if (cmd == TIOCSCTTY) { /* don't allow controlling tty to be set */
	200	error = EINVAL; /* to controlling tty -- infinite recursion */
	201	goto out;
	202	}
1c79356b	203	if (cmd == TIOCNOTTY) {
2d21ac55 A	204	sessp = proc_session(p);
2d21ac55 A	205	if (!SESS_LEADER(p, sessp)) {
b0d623f7	206	OSBitAndAtomic(~((uint32_t)P_CONTROLT), &p->p_flag);
2d21ac55 A	207	if (sessp != SESSION_NULL)
	208	session_rele(sessp);
	209	error = 0;
	210	goto out;
	211	} else {
	212	if (sessp != SESSION_NULL)
	213	session_rele(sessp);
	214	error = EINVAL;
	215	goto out;
	216	}
1c79356b	217	}
2d21ac55	218	context.vc_thread = current_thread();
91447636 A	219	context.vc_ucred = NOCRED;
91447636 A	220
2d21ac55 A	221	error = VNOP_IOCTL(ttyvp, cmd, addr, flag, &context);
	222	out:
	223	vnode_put(ttyvp);
	224	return (error);
1c79356b A	225	}
1c79356b A	226
1c79356b	227	int
2d21ac55	228	cttyselect(__unused dev_t dev, int flag, void* wql, __unused proc_t p)
1c79356b	229	{
2d21ac55	230	vnode_t ttyvp = cttyvp(current_proc());
91447636	231	struct vfs_context context;
2d21ac55	232	int error;
91447636	233
2d21ac55	234	context.vc_thread = current_thread();
91447636	235	context.vc_ucred = NOCRED;
1c79356b A	236
	237	if (ttyvp == NULL)
	238	return (1); /* try operation to get EOF/failure */
2d21ac55 A	239	error = VNOP_SELECT(ttyvp, flag, FREAD\|FWRITE, wql, &context);
	240	vnode_put(ttyvp);
	241	return (error);
1c79356b A	242	}
1c79356b A	243
2d21ac55 A	244	/* This returns vnode with ioref */
	245	static vnode_t
	246	cttyvp(proc_t p)
1c79356b	247	{
2d21ac55 A	248	vnode_t vp;
	249	int vid;
	250	struct session *sessp;
1c79356b	251
2d21ac55	252	sessp = proc_session(p);
1c79356b	253
2d21ac55 A	254	session_lock(sessp);
	255	vp = (p->p_flag & P_CONTROLT ? sessp->s_ttyvp : NULLVP);
	256	vid = sessp->s_ttyvid;
	257	session_unlock(sessp);
	258
	259	session_rele(sessp);
	260
	261	if (vp != NULLVP) {
	262	/* cannot get an IO reference, return NULLVP */
	263	if (vnode_getwithvid(vp, vid) != 0)
	264	vp = NULLVP;
	265	}
	266	return(vp);
	267	}
1c79356b	268