door_vnops.c revision 3898:c788126f2a20 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#pragma ident	"%Z%%M%	%I%	%E% SMI"
27
28#include <sys/types.h>
29#include <sys/vnode.h>
30#include <sys/vfs_opreg.h>
31#include <sys/door.h>
32#include <sys/proc.h>
33#include <sys/kmem.h>
34#include <sys/debug.h>
35#include <sys/cmn_err.h>
36#include <fs/fs_subr.h>
37#include <sys/zone.h>
38#include <sys/tsol/label.h>
39
40kmutex_t	door_knob;
41static int	door_open(struct vnode **vpp, int flag, struct cred *cr);
42static int	door_close(struct vnode *vp, int flag, int count,
43			offset_t offset, struct cred *cr);
44static int	door_getattr(struct vnode *vp, struct vattr *vap,
45			int flags, struct cred *cr);
46static void	door_inactive(struct vnode *vp, struct cred *cr);
47static int	door_access(struct vnode *vp, int mode, int flags,
48			struct cred *cr);
49static int	door_realvp(vnode_t *vp, vnode_t **vpp);
50
51struct vfs door_vfs;
52
53struct vnodeops *door_vnodeops;
54
55const fs_operation_def_t door_vnodeops_template[] = {
56	VOPNAME_OPEN,		{ .vop_open = door_open },
57	VOPNAME_CLOSE,		{ .vop_close = door_close },
58	VOPNAME_GETATTR,	{ .vop_getattr = door_getattr },
59	VOPNAME_ACCESS,		{ .vop_access = door_access },
60	VOPNAME_INACTIVE,	{ .vop_inactive = door_inactive },
61	VOPNAME_FRLOCK,		{ .error = fs_error },
62	VOPNAME_REALVP,		{ .vop_realvp = door_realvp },
63	VOPNAME_POLL,		{ .error = fs_error },
64	VOPNAME_PATHCONF,	{ .error = fs_error },
65	VOPNAME_DISPOSE,	{ .error = fs_error },
66	VOPNAME_GETSECATTR,	{ .error = fs_error },
67	VOPNAME_SHRLOCK,	{ .error = fs_error },
68	NULL,			NULL
69};
70
71/* ARGSUSED */
72static int
73door_open(struct vnode **vpp, int flag, struct cred *cr)
74{
75	/*
76	 * MAC policy for doors.  Restrict cross-zone open()s so that only
77	 * door servers in the global zone can have clients from other zones.
78	 * For other zones, client must be within the same zone as server.
79	 */
80	if (is_system_labeled()) {
81		zone_t		*server_zone, *client_zone;
82		door_node_t	*dp = VTOD((*vpp));
83
84		mutex_enter(&door_knob);
85		if (DOOR_INVALID(dp)) {
86			mutex_exit(&door_knob);
87			return (0);
88		}
89		client_zone = curproc->p_zone;
90		server_zone = dp->door_target->p_zone;
91		mutex_exit(&door_knob);
92		if (server_zone != global_zone &&
93		    server_zone != client_zone)
94			return (EACCES);
95	}
96	return (0);
97}
98
99/* ARGSUSED */
100static int
101door_close(
102	struct vnode *vp,
103	int flag,
104	int count,
105	offset_t offset,
106	struct cred *cr
107)
108{
109	door_node_t	*dp = VTOD(vp);
110
111	/*
112	 * If this is being called from closeall on exit, any doors created
113	 * by this process should have been revoked already in door_exit.
114	 */
115	ASSERT(dp->door_target != curproc ||
116	    ((curthread->t_proc_flag & TP_LWPEXIT) == 0));
117
118	/*
119	 * Deliver an unref if needed.
120	 *
121	 * If the count is equal to 2, it means that I'm doing a VOP_CLOSE
122	 * on the next to last reference for *this* file struct. There may
123	 * be multiple files pointing to this vnode in which case the v_count
124	 * will be > 1.
125	 *
126	 * The door_active count is bumped during each invocation.
127	 */
128	if (count == 2 && vp->v_count == 1 &&
129	    (dp->door_flags & (DOOR_UNREF | DOOR_UNREF_MULTI))) {
130		mutex_enter(&door_knob);
131		if (dp->door_active == 0) {
132			/* o.k. to deliver unref now */
133			door_deliver_unref(dp);
134		} else {
135			/* do the unref later */
136			dp->door_flags |= DOOR_DELAY;
137		}
138		mutex_exit(&door_knob);
139	}
140	return (0);
141}
142
143/* ARGSUSED */
144static int
145door_getattr(struct vnode *vp, struct vattr *vap, int flags, struct cred *cr)
146{
147	static timestruc_t tzero = {0, 0};
148	extern dev_t doordev;
149
150	vap->va_mask = 0;		/* bit-mask of attributes */
151	vap->va_type = vp->v_type;	/* vnode type (for create) */
152	vap->va_mode = 0777;		/* file access mode */
153	vap->va_uid = 0;		/* owner user id */
154	vap->va_gid = 0;		/* owner group id */
155	vap->va_fsid = doordev;		/* file system id (dev for now) */
156	vap->va_nodeid = (ino64_t)0;		/* node id */
157	vap->va_nlink = vp->v_count;	/* number of references to file */
158	vap->va_size = (u_offset_t)0;		/* file size in bytes */
159	vap->va_atime = tzero;		/* time of last access */
160	vap->va_mtime = tzero;		/* time of last modification */
161	vap->va_ctime = tzero;		/* time file ``created'' */
162	vap->va_rdev = doordev;		/* device the file represents */
163	vap->va_blksize = 0;		/* fundamental block size */
164	vap->va_nblocks = (fsblkcnt64_t)0;	/* # of blocks allocated */
165	vap->va_seq = 0;		/* sequence number */
166
167	return (0);
168}
169
170/* ARGSUSED */
171static void
172door_inactive(struct vnode *vp, struct cred *cr)
173{
174	door_node_t *dp = VTOD(vp);
175
176	mutex_enter(&vp->v_lock);
177	/*
178	 * Once the door_node is unreferenced, it stays unreferenced,
179	 * so we can simply return if there are active thread bindings;
180	 * the final door_unbind_thread() will re-invoke us.
181	 */
182	ASSERT(vp->v_count == 1);
183	if (dp->door_bound_threads > 0) {
184		vp->v_count--;
185		mutex_exit(&vp->v_lock);
186		return;
187	}
188	mutex_exit(&vp->v_lock);
189
190	/* if not revoked, remove door from per-process list */
191	if (dp->door_target) {
192		mutex_enter(&door_knob);
193		if (dp->door_target)	/* recheck door_target under lock */
194			door_list_delete(dp);
195		mutex_exit(&door_knob);
196	}
197	vn_invalid(vp);
198	vn_free(vp);
199	kmem_free(dp, sizeof (door_node_t));
200}
201
202/*
203 * To avoid having bound threads interfere with unref processing, we
204 * don't use VN_HOLD/VN_RELE to track threads bound to our private
205 * pool.  Instead, we keep a separate counter, also under v_lock.
206 */
207void
208door_bind_thread(door_node_t *dp)
209{
210	vnode_t *vp = DTOV(dp);
211
212	mutex_enter(&vp->v_lock);
213	dp->door_bound_threads++;
214	ASSERT(dp->door_bound_threads > 0 && vp->v_count > 0);
215	mutex_exit(&vp->v_lock);
216}
217
218void
219door_unbind_thread(door_node_t *dp)
220{
221	vnode_t *vp = DTOV(dp);
222	int do_inactive = 0;
223
224	mutex_enter(&vp->v_lock);
225	ASSERT(dp->door_bound_threads > 0);
226	if (--dp->door_bound_threads == 0 && vp->v_count == 0) {
227		/* set up for inactive handling */
228		vp->v_count++;
229		do_inactive = 1;
230	}
231	mutex_exit(&vp->v_lock);
232
233	if (do_inactive)
234		door_inactive(vp, NULL);
235}
236
237/* ARGSUSED */
238static int
239door_access(struct vnode *vp, int mode, int flags, struct cred *cr)
240{
241	return (0);
242}
243
244/* ARGSUSED */
245static int
246door_realvp(vnode_t *vp, vnode_t **vpp)
247{
248	*vpp = vp;
249	return (0);
250}
251