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 * Copyright (c) 2017 by Delphix. All rights reserved.
27 */
28
29 #include <sys/types.h>
30 #include <sys/vnode.h>
31 #include <sys/vfs_opreg.h>
32 #include <sys/door.h>
33 #include <sys/proc.h>
34 #include <sys/kmem.h>
35 #include <sys/debug.h>
36 #include <sys/cmn_err.h>
37 #include <fs/fs_subr.h>
38 #include <sys/zone.h>
39 #include <sys/tsol/label.h>
40
41 kmutex_t door_knob;
42 static int door_open(struct vnode **vpp, int flag, struct cred *cr,
43 caller_context_t *ct);
44 static int door_close(struct vnode *vp, int flag, int count,
45 offset_t offset, struct cred *cr, caller_context_t *ct);
46 static int door_getattr(struct vnode *vp, struct vattr *vap,
47 int flags, struct cred *cr, caller_context_t *ct);
48 static void door_inactive(struct vnode *vp, struct cred *cr,
49 caller_context_t *ct);
50 static int door_access(struct vnode *vp, int mode, int flags,
51 struct cred *cr, caller_context_t *ct);
52 static int door_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct);
53
54 struct vfs door_vfs;
55
56 struct vnodeops *door_vnodeops;
57
58 const fs_operation_def_t door_vnodeops_template[] = {
59 VOPNAME_OPEN, { .vop_open = door_open },
60 VOPNAME_CLOSE, { .vop_close = door_close },
61 VOPNAME_GETATTR, { .vop_getattr = door_getattr },
62 VOPNAME_ACCESS, { .vop_access = door_access },
63 VOPNAME_INACTIVE, { .vop_inactive = door_inactive },
64 VOPNAME_FRLOCK, { .error = fs_error },
65 VOPNAME_REALVP, { .vop_realvp = door_realvp },
66 VOPNAME_POLL, { .error = fs_error },
67 VOPNAME_PATHCONF, { .error = fs_error },
68 VOPNAME_DISPOSE, { .error = fs_error },
69 VOPNAME_GETSECATTR, { .error = fs_error },
70 VOPNAME_SHRLOCK, { .error = fs_error },
71 NULL, NULL
72 };
73
74 /* ARGSUSED */
75 static int
door_open(struct vnode ** vpp,int flag,struct cred * cr,caller_context_t * ct)76 door_open(struct vnode **vpp, int flag, struct cred *cr, caller_context_t *ct)
77 {
78 /*
79 * MAC policy for doors. Restrict cross-zone open()s so that only
80 * door servers in the global zone can have clients from other zones.
81 * For other zones, client must be within the same zone as server.
82 */
83 if (is_system_labeled()) {
84 zone_t *server_zone, *client_zone;
85 door_node_t *dp = VTOD((*vpp));
86
87 mutex_enter(&door_knob);
88 if (DOOR_INVALID(dp)) {
89 mutex_exit(&door_knob);
90 return (0);
91 }
92 client_zone = curproc->p_zone;
93 server_zone = dp->door_target->p_zone;
94 mutex_exit(&door_knob);
95 if (server_zone != global_zone &&
96 server_zone != client_zone)
97 return (EACCES);
98 }
99 return (0);
100 }
101
102 /* ARGSUSED */
103 static int
door_close(struct vnode * vp,int flag,int count,offset_t offset,struct cred * cr,caller_context_t * ct)104 door_close(struct vnode *vp, int flag, int count, offset_t offset,
105 struct cred *cr, caller_context_t *ct)
106 {
107 door_node_t *dp = VTOD(vp);
108
109 /*
110 * If this is being called from closeall on exit, any doors created
111 * by this process should have been revoked already in door_exit.
112 */
113 ASSERT(dp->door_target != curproc ||
114 ((curthread->t_proc_flag & TP_LWPEXIT) == 0));
115
116 /*
117 * Deliver an unref if needed.
118 *
119 * If the count is equal to 2, it means that I'm doing a VOP_CLOSE
120 * on the next to last reference for *this* file struct. There may
121 * be multiple files pointing to this vnode in which case the v_count
122 * will be > 1.
123 *
124 * The door_active count is bumped during each invocation.
125 */
126 if (count == 2 && vp->v_count == 1 &&
127 (dp->door_flags & (DOOR_UNREF | DOOR_UNREF_MULTI))) {
128 mutex_enter(&door_knob);
129 if (dp->door_active == 0) {
130 /* o.k. to deliver unref now */
131 door_deliver_unref(dp);
132 } else {
133 /* do the unref later */
134 dp->door_flags |= DOOR_DELAY;
135 }
136 mutex_exit(&door_knob);
137 }
138 return (0);
139 }
140
141 /* ARGSUSED */
142 static int
door_getattr(struct vnode * vp,struct vattr * vap,int flags,struct cred * cr,caller_context_t * ct)143 door_getattr(struct vnode *vp, struct vattr *vap, int flags, struct cred *cr,
144 caller_context_t *ct)
145 {
146 static timestruc_t tzero = {0, 0};
147 extern dev_t doordev;
148
149 vap->va_mask = 0; /* bit-mask of attributes */
150 vap->va_type = vp->v_type; /* vnode type (for create) */
151 vap->va_mode = 0777; /* file access mode */
152 vap->va_uid = 0; /* owner user id */
153 vap->va_gid = 0; /* owner group id */
154 vap->va_fsid = doordev; /* file system id (dev for now) */
155 vap->va_nodeid = (ino64_t)0; /* node id */
156 vap->va_nlink = vp->v_count; /* number of references to file */
157 vap->va_size = (u_offset_t)0; /* file size in bytes */
158 vap->va_atime = tzero; /* time of last access */
159 vap->va_mtime = tzero; /* time of last modification */
160 vap->va_ctime = tzero; /* time file ``created'' */
161 vap->va_rdev = doordev; /* device the file represents */
162 vap->va_blksize = 0; /* fundamental block size */
163 vap->va_nblocks = (fsblkcnt64_t)0; /* # of blocks allocated */
164 vap->va_seq = 0; /* sequence number */
165
166 return (0);
167 }
168
169 /* ARGSUSED */
170 static void
door_inactive(struct vnode * vp,struct cred * cr,caller_context_t * ct)171 door_inactive(struct vnode *vp, struct cred *cr, caller_context_t *ct)
172 {
173 door_node_t *dp = VTOD(vp);
174
175 mutex_enter(&vp->v_lock);
176 /*
177 * Once the door_node is unreferenced, it stays unreferenced,
178 * so we can simply return if there are active thread bindings;
179 * the final door_unbind_thread() will re-invoke us.
180 */
181 ASSERT(vp->v_count == 1);
182 if (dp->door_bound_threads > 0) {
183 VN_RELE_LOCKED(vp);
184 mutex_exit(&vp->v_lock);
185 return;
186 }
187 mutex_exit(&vp->v_lock);
188
189 /* if not revoked, remove door from per-process list */
190 if (dp->door_target) {
191 mutex_enter(&door_knob);
192 if (dp->door_target) /* recheck door_target under lock */
193 door_list_delete(dp);
194 mutex_exit(&door_knob);
195 }
196 vn_invalid(vp);
197 vn_free(vp);
198 kmem_free(dp, sizeof (door_node_t));
199 }
200
201 /*
202 * To avoid having bound threads interfere with unref processing, we
203 * don't use VN_HOLD/VN_RELE to track threads bound to our private
204 * pool. Instead, we keep a separate counter, also under v_lock.
205 */
206 void
door_bind_thread(door_node_t * dp)207 door_bind_thread(door_node_t *dp)
208 {
209 vnode_t *vp = DTOV(dp);
210
211 mutex_enter(&vp->v_lock);
212 dp->door_bound_threads++;
213 ASSERT(dp->door_bound_threads > 0 && vp->v_count > 0);
214 mutex_exit(&vp->v_lock);
215 }
216
217 void
door_unbind_thread(door_node_t * dp)218 door_unbind_thread(door_node_t *dp)
219 {
220 vnode_t *vp = DTOV(dp);
221 int do_inactive = 0;
222
223 mutex_enter(&vp->v_lock);
224 ASSERT(dp->door_bound_threads > 0);
225 if (--dp->door_bound_threads == 0 && vp->v_count == 0) {
226 /* set up for inactive handling */
227 VN_HOLD_LOCKED(vp);
228 do_inactive = 1;
229 }
230 mutex_exit(&vp->v_lock);
231
232 if (do_inactive)
233 door_inactive(vp, NULL, NULL);
234 }
235
236 /* ARGSUSED */
237 static int
door_access(struct vnode * vp,int mode,int flags,struct cred * cr,caller_context_t * ct)238 door_access(struct vnode *vp, int mode, int flags, struct cred *cr,
239 caller_context_t *ct)
240 {
241 return (0);
242 }
243
244 /* ARGSUSED */
245 static int
door_realvp(vnode_t * vp,vnode_t ** vpp,caller_context_t * ct)246 door_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct)
247 {
248 *vpp = vp;
249 return (0);
250 }
251