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 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/vnode.h>
31 #include <sys/vfs_opreg.h>
32 #include <sys/kmem.h>
33 #include <fs/fs_subr.h>
34 #include <sys/proc.h>
35 #include <sys/kstat.h>
36 #include <sys/port_impl.h>
37 
38 /* local functions */
39 static int port_open(struct vnode **, int, cred_t *, caller_context_t *);
40 static int port_close(struct vnode *, int, int, offset_t, cred_t *,
41 	caller_context_t *);
42 static int port_getattr(struct vnode *, struct vattr *, int, cred_t *,
43 	caller_context_t *);
44 static int port_access(struct vnode *, int, int, cred_t *, caller_context_t *);
45 static int port_realvp(vnode_t *, vnode_t **, caller_context_t *);
46 static int port_poll(vnode_t *, short, int, short *, struct pollhead **,
47 	caller_context_t *);
48 static void port_inactive(struct vnode *, cred_t *, caller_context_t *);
49 
50 const fs_operation_def_t port_vnodeops_template[] = {
51 	VOPNAME_OPEN,		{ .vop_open = port_open },
52 	VOPNAME_CLOSE,		{ .vop_close = port_close },
53 	VOPNAME_GETATTR,	{ .vop_getattr = port_getattr },
54 	VOPNAME_ACCESS,		{ .vop_access = port_access },
55 	VOPNAME_INACTIVE,	{ .vop_inactive = port_inactive },
56 	VOPNAME_FRLOCK,		{ .error = fs_error },
57 	VOPNAME_REALVP,		{ .vop_realvp = port_realvp },
58 	VOPNAME_POLL,		{ .vop_poll = port_poll },
59 	VOPNAME_PATHCONF,	{ .error = fs_error },
60 	VOPNAME_DISPOSE,	{ .error = fs_error },
61 	VOPNAME_GETSECATTR,	{ .error = fs_error },
62 	VOPNAME_SHRLOCK,	{ .error = fs_error },
63 	NULL,			NULL
64 };
65 
66 /* ARGSUSED */
67 static int
68 port_open(struct vnode **vpp, int flag, cred_t *cr, caller_context_t *ct)
69 {
70 	return (0);
71 }
72 
73 /*
74  * port_discard_events() scans the port event queue for events owned
75  * by current proc. Non-shareable events will be discarded, all other
76  * events remain in the event queue.
77  */
78 void
79 port_discard_events(port_queue_t *portq)
80 {
81 	port_kevent_t	*kevp;
82 	pid_t		pid = curproc->p_pid;
83 
84 	/*
85 	 * The call to port_block() is required to avoid interaction
86 	 * with other threads in port_get(n).
87 	 */
88 	mutex_enter(&portq->portq_mutex);
89 	port_block(portq);
90 	port_push_eventq(portq);	/* empty temporary queue */
91 	kevp = list_head(&portq->portq_list);
92 	while (kevp) {
93 		if (kevp->portkev_pid == pid) {
94 			/* own event, check if it is shareable */
95 			if (kevp->portkev_flags & PORT_KEV_NOSHARE)
96 				kevp->portkev_flags |= PORT_KEV_FREE;
97 		}
98 		kevp = list_next(&portq->portq_list, kevp);
99 	}
100 	port_unblock(portq);
101 	mutex_exit(&portq->portq_mutex);
102 }
103 
104 /*
105  * Called from port_close().
106  * Free all kernel events structures which are still in the event queue.
107  */
108 static void
109 port_close_events(port_queue_t *portq)
110 {
111 	port_kevent_t	*pkevp;
112 	int		events;		/* ignore events */
113 
114 	mutex_enter(&portq->portq_mutex);
115 	while (pkevp = list_head(&portq->portq_list)) {
116 		portq->portq_nent--;
117 		list_remove(&portq->portq_list, pkevp);
118 		if (pkevp->portkev_callback) {
119 			(void) (*pkevp->portkev_callback)(pkevp->portkev_arg,
120 			    &events, pkevp->portkev_pid, PORT_CALLBACK_CLOSE,
121 			    pkevp);
122 		}
123 		mutex_exit(&portq->portq_mutex);
124 		port_free_event_local(pkevp, 0);
125 		mutex_enter(&portq->portq_mutex);
126 	}
127 
128 	/*
129 	 * Wait for any thread in pollwakeup(), accessing this port to
130 	 * finish.
131 	 */
132 	while (portq->portq_flags & PORTQ_POLLWK_PEND) {
133 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
134 	}
135 	mutex_exit(&portq->portq_mutex);
136 }
137 
138 /*
139  * The port_close() function is called from standard close(2) when
140  * the file descriptor is of type S_IFPORT/VPORT.
141  * Port file descriptors behave like standard file descriptors. It means,
142  * the port file/vnode is only destroyed on last close.
143  * If the reference counter is > 1 then
144  * - sources associated with the port will be notified about the close,
145  * - objects associated with the port will be dissociated,
146  * - pending and delivered events will be discarded.
147  * On last close all references and caches will be removed. The vnode itself
148  * will be destroyed with VOP_RELE().
149  */
150 /* ARGSUSED */
151 static int
152 port_close(struct vnode *vp, int flag, int count, offset_t offset, cred_t *cr,
153     caller_context_t *ct)
154 {
155 	port_t		*pp;
156 	port_queue_t	*portq;
157 	port_source_t	*ps;
158 	port_source_t	*ps_next;
159 	int		source;
160 
161 	pp = VTOEP(vp);
162 	mutex_enter(&pp->port_mutex);
163 	if (pp->port_flags & PORT_CLOSED) {
164 		mutex_exit(&pp->port_mutex);
165 		return (0);
166 	}
167 	mutex_exit(&pp->port_mutex);
168 
169 	portq = &pp->port_queue;
170 	if (count > 1) {
171 		/*
172 		 * It is not the last close.
173 		 * Remove/free all event resources owned by the current proc
174 		 * First notify all with the port associated sources about the
175 		 * close(2). The last argument of the close callback function
176 		 * advises the source about the type of of the close.
177 		 * If the port was set in alert mode by the curren process then
178 		 * remove the alert mode.
179 		 */
180 
181 		/* check alert mode of the port */
182 		mutex_enter(&portq->portq_mutex);
183 		if ((portq->portq_flags & PORTQ_ALERT) &&
184 		    (portq->portq_alert.portal_pid == curproc->p_pid))
185 			portq->portq_flags &= ~PORTQ_ALERT;
186 		mutex_exit(&portq->portq_mutex);
187 
188 		/* notify all event sources about port_close() */
189 		mutex_enter(&portq->portq_source_mutex);
190 		for (source = 0; source < PORT_SCACHE_SIZE; source++) {
191 			ps = portq->portq_scache[PORT_SHASH(source)];
192 			for (; ps != NULL; ps = ps->portsrc_next) {
193 				if (ps->portsrc_close != NULL)
194 					(*ps->portsrc_close)
195 					    (ps->portsrc_closearg, pp->port_fd,
196 					    curproc->p_pid, 0);
197 			}
198 		}
199 		mutex_exit(&portq->portq_source_mutex);
200 		port_discard_events(&pp->port_queue);
201 		return (0);
202 	}
203 
204 	/*
205 	 * We are executing the last close of the port -> discard everything
206 	 * Make sure that all threads/processes accessing this port leave
207 	 * the kernel immediately.
208 	 */
209 
210 	mutex_enter(&portq->portq_mutex);
211 	portq->portq_flags |= PORTQ_CLOSE;
212 	while (portq->portq_thrcnt > 0) {
213 		if (portq->portq_thread != NULL)
214 			cv_signal(&portq->portq_thread->portget_cv);
215 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
216 	}
217 	mutex_exit(&portq->portq_mutex);
218 
219 	/*
220 	 * Send "last close" message to associated sources.
221 	 * - new event allocation requests are being denied since uf_file entry
222 	 *   was set to NULL in closeandsetf().
223 	 * - all still allocated event structures must be returned to the
224 	 *   port immediately:
225 	 *	- call port_free_event(*event) or
226 	 *	- call port_send_event(*event) to complete event operations
227 	 *	  which need activities in a dedicated process environment.
228 	 * The port_close() function waits until all allocated event structures
229 	 * are delivered back to the port.
230 	 */
231 
232 	mutex_enter(&portq->portq_source_mutex);
233 	for (source = 0; source < PORT_SCACHE_SIZE; source++) {
234 		ps = portq->portq_scache[PORT_SHASH(source)];
235 		for (; ps != NULL; ps = ps_next) {
236 			ps_next = ps->portsrc_next;
237 			if (ps->portsrc_close != NULL)
238 				(*ps->portsrc_close)(ps->portsrc_closearg,
239 				    pp->port_fd, curproc->p_pid, 1);
240 			kmem_free(ps, sizeof (port_source_t));
241 		}
242 	}
243 	kmem_free(portq->portq_scache,
244 	    PORT_SCACHE_SIZE * sizeof (port_source_t *));
245 	portq->portq_scache = NULL;
246 	mutex_exit(&portq->portq_source_mutex);
247 
248 	mutex_enter(&portq->portq_mutex);
249 	/* Wait for outstanding events */
250 	while (pp->port_curr > portq->portq_nent)
251 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
252 	mutex_exit(&portq->portq_mutex);
253 
254 	/*
255 	 * If PORT_SOURCE_FD objects were not associated with the port then
256 	 * it is necessary to free the port_fdcache structure here.
257 	 */
258 
259 	if (portq->portq_pcp != NULL) {
260 		mutex_destroy(&portq->portq_pcp->pc_lock);
261 		kmem_free(portq->portq_pcp, sizeof (port_fdcache_t));
262 		portq->portq_pcp = NULL;
263 	}
264 
265 	/*
266 	 * Now all events are passed back to the port,
267 	 * discard remaining events in the port queue
268 	 */
269 
270 	port_close_events(portq);
271 	return (0);
272 }
273 
274 /*
275  * The port_poll() function is the VOP_POLL() entry of event ports.
276  * Event ports return:
277  * POLLIN  : events are available in the event queue
278  * POLLOUT : event queue can still accept events
279  */
280 /*ARGSUSED*/
281 static int
282 port_poll(vnode_t *vp, short events, int anyyet, short *reventsp,
283     struct pollhead **phpp, caller_context_t *ct)
284 {
285 	port_t		*pp;
286 	port_queue_t	*portq;
287 	short		levents;
288 
289 	pp = VTOEP(vp);
290 	portq = &pp->port_queue;
291 	levents = 0;
292 	mutex_enter(&portq->portq_mutex);
293 	if (portq->portq_nent)
294 		levents = POLLIN;
295 	if (pp->port_curr < pp->port_max_events)
296 		levents |= POLLOUT;
297 	levents &= events;
298 	*reventsp = levents;
299 	if (levents == 0) {
300 		if (!anyyet) {
301 			*phpp = &pp->port_pollhd;
302 			portq->portq_flags |=
303 			    events & POLLIN ? PORTQ_POLLIN : 0;
304 			portq->portq_flags |=
305 			    events & POLLOUT ? PORTQ_POLLOUT : 0;
306 		}
307 	}
308 	mutex_exit(&portq->portq_mutex);
309 	return (0);
310 }
311 
312 
313 /* ARGSUSED */
314 static int
315 port_getattr(struct vnode *vp, struct vattr *vap, int flags, cred_t *cr,
316     caller_context_t *ct)
317 {
318 	port_t	*pp;
319 	extern dev_t portdev;
320 
321 	pp = VTOEP(vp);
322 
323 	vap->va_mask = 0;		/* bit-mask of attributes */
324 	vap->va_type = vp->v_type;	/* vnode type (for create) */
325 	vap->va_mode = 0;		/* file access mode */
326 	vap->va_uid = pp->port_uid;	/* owner user id */
327 	vap->va_gid = pp->port_gid;	/* owner group id */
328 	vap->va_fsid = portdev;		/* file system id  */
329 	vap->va_nodeid = (ino64_t)0;	/* node id */
330 	vap->va_nlink = vp->v_count;	/* number of references to file */
331 	vap->va_size = (u_offset_t)pp->port_queue.portq_nent; /* file size */
332 	vap->va_atime = pp->port_ctime;	/* time of last access */
333 	vap->va_mtime = pp->port_ctime;	/* time of last modification */
334 	vap->va_ctime = pp->port_ctime;	/* time file ``created'' */
335 	vap->va_rdev = portdev;		/* device the file represents */
336 	vap->va_blksize = 0;		/* fundamental block size */
337 	vap->va_nblocks = (fsblkcnt64_t)0;	/* # of blocks allocated */
338 	vap->va_seq = 0;		/* sequence number */
339 
340 	return (0);
341 }
342 
343 /*
344  * Destroy the port.
345  */
346 /* ARGSUSED */
347 static void
348 port_inactive(struct vnode *vp, cred_t *cr, caller_context_t *ct)
349 {
350 	port_t 	*pp = VTOEP(vp);
351 	extern 	port_kstat_t port_kstat;
352 
353 	mutex_enter(&port_control.pc_mutex);
354 	port_control.pc_nents--;
355 	curproc->p_portcnt--;
356 	port_kstat.pks_ports.value.ui32--;
357 	mutex_exit(&port_control.pc_mutex);
358 	vn_free(vp);
359 	mutex_destroy(&pp->port_mutex);
360 	mutex_destroy(&pp->port_queue.portq_mutex);
361 	mutex_destroy(&pp->port_queue.portq_source_mutex);
362 	kmem_free(pp, sizeof (port_t));
363 }
364 
365 /* ARGSUSED */
366 static int
367 port_access(struct vnode *vp, int mode, int flags, cred_t *cr,
368     caller_context_t *ct)
369 {
370 	return (0);
371 }
372 
373 /* ARGSUSED */
374 static int
375 port_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct)
376 {
377 	*vpp = vp;
378 	return (0);
379 }
380