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 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Copyright (c) 2014, Joyent, Inc.  All rights reserved.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/vnode.h>
33 #include <sys/vfs_opreg.h>
34 #include <sys/kmem.h>
35 #include <fs/fs_subr.h>
36 #include <sys/proc.h>
37 #include <sys/kstat.h>
38 #include <sys/port_impl.h>
39 
40 /* local functions */
41 static int port_open(struct vnode **, int, cred_t *, caller_context_t *);
42 static int port_close(struct vnode *, int, int, offset_t, cred_t *,
43 	caller_context_t *);
44 static int port_getattr(struct vnode *, struct vattr *, int, cred_t *,
45 	caller_context_t *);
46 static int port_access(struct vnode *, int, int, cred_t *, caller_context_t *);
47 static int port_realvp(vnode_t *, vnode_t **, caller_context_t *);
48 static int port_poll(vnode_t *, short, int, short *, struct pollhead **,
49 	caller_context_t *);
50 static void port_inactive(struct vnode *, cred_t *, caller_context_t *);
51 
52 const fs_operation_def_t port_vnodeops_template[] = {
53 	VOPNAME_OPEN,		{ .vop_open = port_open },
54 	VOPNAME_CLOSE,		{ .vop_close = port_close },
55 	VOPNAME_GETATTR,	{ .vop_getattr = port_getattr },
56 	VOPNAME_ACCESS,		{ .vop_access = port_access },
57 	VOPNAME_INACTIVE,	{ .vop_inactive = port_inactive },
58 	VOPNAME_FRLOCK,		{ .error = fs_error },
59 	VOPNAME_REALVP,		{ .vop_realvp = port_realvp },
60 	VOPNAME_POLL,		{ .vop_poll = port_poll },
61 	VOPNAME_PATHCONF,	{ .error = fs_error },
62 	VOPNAME_DISPOSE,	{ .error = fs_error },
63 	VOPNAME_GETSECATTR,	{ .error = fs_error },
64 	VOPNAME_SHRLOCK,	{ .error = fs_error },
65 	NULL,			NULL
66 };
67 
68 /* ARGSUSED */
69 static int
port_open(struct vnode ** vpp,int flag,cred_t * cr,caller_context_t * ct)70 port_open(struct vnode **vpp, int flag, cred_t *cr, caller_context_t *ct)
71 {
72 	return (0);
73 }
74 
75 /*
76  * port_discard_events() scans the port event queue for events owned
77  * by current proc. Non-shareable events will be discarded, all other
78  * events remain in the event queue.
79  */
80 void
port_discard_events(port_queue_t * portq)81 port_discard_events(port_queue_t *portq)
82 {
83 	port_kevent_t	*kevp;
84 	pid_t		pid = curproc->p_pid;
85 
86 	/*
87 	 * The call to port_block() is required to avoid interaction
88 	 * with other threads in port_get(n).
89 	 */
90 	mutex_enter(&portq->portq_mutex);
91 	port_block(portq);
92 	port_push_eventq(portq);	/* empty temporary queue */
93 	kevp = list_head(&portq->portq_list);
94 	while (kevp) {
95 		if (kevp->portkev_pid == pid) {
96 			/* own event, check if it is shareable */
97 			if (kevp->portkev_flags & PORT_KEV_NOSHARE)
98 				kevp->portkev_flags |= PORT_KEV_FREE;
99 		}
100 		kevp = list_next(&portq->portq_list, kevp);
101 	}
102 	port_unblock(portq);
103 	mutex_exit(&portq->portq_mutex);
104 }
105 
106 /*
107  * Called from port_close().
108  * Free all kernel events structures which are still in the event queue.
109  */
110 static void
port_close_events(port_queue_t * portq)111 port_close_events(port_queue_t *portq)
112 {
113 	port_kevent_t	*pkevp;
114 	int		events;		/* ignore events */
115 
116 	mutex_enter(&portq->portq_mutex);
117 	while (pkevp = list_head(&portq->portq_list)) {
118 		portq->portq_nent--;
119 		list_remove(&portq->portq_list, pkevp);
120 		if (pkevp->portkev_callback) {
121 			(void) (*pkevp->portkev_callback)(pkevp->portkev_arg,
122 			    &events, pkevp->portkev_pid, PORT_CALLBACK_CLOSE,
123 			    pkevp);
124 		}
125 		mutex_exit(&portq->portq_mutex);
126 		port_free_event_local(pkevp, 0);
127 		mutex_enter(&portq->portq_mutex);
128 	}
129 
130 	/*
131 	 * Wait for any thread in pollwakeup(), accessing this port to
132 	 * finish.
133 	 */
134 	while (portq->portq_flags & PORTQ_POLLWK_PEND) {
135 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
136 	}
137 	mutex_exit(&portq->portq_mutex);
138 }
139 
140 /*
141  * The port_close() function is called from standard close(2) when
142  * the file descriptor is of type S_IFPORT/VPORT.
143  * Port file descriptors behave like standard file descriptors. It means,
144  * the port file/vnode is only destroyed on last close.
145  * If the reference counter is > 1 then
146  * - sources associated with the port will be notified about the close,
147  * - objects associated with the port will be dissociated,
148  * - pending and delivered events will be discarded.
149  * On last close all references and caches will be removed. The vnode itself
150  * will be destroyed with VOP_RELE().
151  */
152 /* ARGSUSED */
153 static int
port_close(struct vnode * vp,int flag,int count,offset_t offset,cred_t * cr,caller_context_t * ct)154 port_close(struct vnode *vp, int flag, int count, offset_t offset, cred_t *cr,
155     caller_context_t *ct)
156 {
157 	port_t		*pp;
158 	port_queue_t	*portq;
159 	port_source_t	*ps;
160 	port_source_t	*ps_next;
161 	int		source;
162 
163 	pp = VTOEP(vp);
164 	mutex_enter(&pp->port_mutex);
165 	if (pp->port_flags & PORT_CLOSED) {
166 		mutex_exit(&pp->port_mutex);
167 		return (0);
168 	}
169 	mutex_exit(&pp->port_mutex);
170 
171 	portq = &pp->port_queue;
172 	if (count > 1) {
173 		/*
174 		 * It is not the last close.
175 		 * Remove/free all event resources owned by the current proc
176 		 * First notify all with the port associated sources about the
177 		 * close(2). The last argument of the close callback function
178 		 * advises the source about the type of of the close.
179 		 * If the port was set in alert mode by the curren process then
180 		 * remove the alert mode.
181 		 */
182 
183 		/* check alert mode of the port */
184 		mutex_enter(&portq->portq_mutex);
185 		if ((portq->portq_flags & PORTQ_ALERT) &&
186 		    (portq->portq_alert.portal_pid == curproc->p_pid))
187 			portq->portq_flags &= ~PORTQ_ALERT;
188 		mutex_exit(&portq->portq_mutex);
189 
190 		/* notify all event sources about port_close() */
191 		mutex_enter(&portq->portq_source_mutex);
192 		for (source = 0; source < PORT_SCACHE_SIZE; source++) {
193 			ps = portq->portq_scache[PORT_SHASH(source)];
194 			for (; ps != NULL; ps = ps->portsrc_next) {
195 				if (ps->portsrc_close != NULL)
196 					(*ps->portsrc_close)
197 					    (ps->portsrc_closearg, pp->port_fd,
198 					    curproc->p_pid, 0);
199 			}
200 		}
201 		mutex_exit(&portq->portq_source_mutex);
202 		port_discard_events(&pp->port_queue);
203 		return (0);
204 	}
205 
206 	/*
207 	 * We are executing the last close of the port -> discard everything
208 	 * Make sure that all threads/processes accessing this port leave
209 	 * the kernel immediately.
210 	 */
211 
212 	mutex_enter(&portq->portq_mutex);
213 	portq->portq_flags |= PORTQ_CLOSE;
214 	while (portq->portq_thrcnt > 0) {
215 		if (portq->portq_thread != NULL)
216 			cv_signal(&portq->portq_thread->portget_cv);
217 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
218 	}
219 	mutex_exit(&portq->portq_mutex);
220 
221 	/*
222 	 * Send "last close" message to associated sources.
223 	 * - new event allocation requests are being denied since uf_file entry
224 	 *   was set to NULL in closeandsetf().
225 	 * - all still allocated event structures must be returned to the
226 	 *   port immediately:
227 	 *	- call port_free_event(*event) or
228 	 *	- call port_send_event(*event) to complete event operations
229 	 *	  which need activities in a dedicated process environment.
230 	 * The port_close() function waits until all allocated event structures
231 	 * are delivered back to the port.
232 	 */
233 
234 	mutex_enter(&portq->portq_source_mutex);
235 	for (source = 0; source < PORT_SCACHE_SIZE; source++) {
236 		ps = portq->portq_scache[PORT_SHASH(source)];
237 		for (; ps != NULL; ps = ps_next) {
238 			ps_next = ps->portsrc_next;
239 			if (ps->portsrc_close != NULL)
240 				(*ps->portsrc_close)(ps->portsrc_closearg,
241 				    pp->port_fd, curproc->p_pid, 1);
242 			kmem_free(ps, sizeof (port_source_t));
243 		}
244 	}
245 	kmem_free(portq->portq_scache,
246 	    PORT_SCACHE_SIZE * sizeof (port_source_t *));
247 	portq->portq_scache = NULL;
248 	mutex_exit(&portq->portq_source_mutex);
249 
250 	mutex_enter(&portq->portq_mutex);
251 	/* Wait for outstanding events */
252 	while (pp->port_curr > portq->portq_nent)
253 		cv_wait(&portq->portq_closecv, &portq->portq_mutex);
254 	mutex_exit(&portq->portq_mutex);
255 
256 	/*
257 	 * If PORT_SOURCE_FD objects were not associated with the port then
258 	 * it is necessary to free the port_fdcache structure here.
259 	 */
260 
261 	if (portq->portq_pcp != NULL) {
262 		mutex_destroy(&portq->portq_pcp->pc_lock);
263 		kmem_free(portq->portq_pcp, sizeof (port_fdcache_t));
264 		portq->portq_pcp = NULL;
265 	}
266 
267 	/*
268 	 * Now all events are passed back to the port,
269 	 * discard remaining events in the port queue
270 	 */
271 
272 	port_close_events(portq);
273 	return (0);
274 }
275 
276 /*
277  * The port_poll() function is the VOP_POLL() entry of event ports.
278  * Event ports return:
279  * POLLIN  : events are available in the event queue
280  * POLLOUT : event queue can still accept events
281  */
282 /*ARGSUSED*/
283 static int
port_poll(vnode_t * vp,short events,int anyyet,short * reventsp,struct pollhead ** phpp,caller_context_t * ct)284 port_poll(vnode_t *vp, short events, int anyyet, short *reventsp,
285     struct pollhead **phpp, caller_context_t *ct)
286 {
287 	port_t		*pp;
288 	port_queue_t	*portq;
289 	short		levents;
290 
291 	pp = VTOEP(vp);
292 	portq = &pp->port_queue;
293 	levents = 0;
294 	mutex_enter(&portq->portq_mutex);
295 	if (portq->portq_nent)
296 		levents = POLLIN;
297 	if (pp->port_curr < pp->port_max_events)
298 		levents |= POLLOUT;
299 	levents &= events;
300 	*reventsp = levents;
301 	if ((levents == 0 && !anyyet) || (events & POLLET)) {
302 		*phpp = &pp->port_pollhd;
303 		portq->portq_flags |= events & POLLIN ? PORTQ_POLLIN : 0;
304 		portq->portq_flags |= events & POLLOUT ? PORTQ_POLLOUT : 0;
305 	}
306 	mutex_exit(&portq->portq_mutex);
307 	return (0);
308 }
309 
310 
311 /* ARGSUSED */
312 static int
port_getattr(struct vnode * vp,struct vattr * vap,int flags,cred_t * cr,caller_context_t * ct)313 port_getattr(struct vnode *vp, struct vattr *vap, int flags, cred_t *cr,
314     caller_context_t *ct)
315 {
316 	port_t	*pp;
317 	extern dev_t portdev;
318 
319 	pp = VTOEP(vp);
320 
321 	vap->va_type = vp->v_type;	/* vnode type (for create) */
322 	vap->va_mode = 0;		/* file access mode */
323 	vap->va_uid = pp->port_uid;	/* owner user id */
324 	vap->va_gid = pp->port_gid;	/* owner group id */
325 	vap->va_fsid = portdev;		/* file system id  */
326 	vap->va_nodeid = (ino64_t)0;	/* node id */
327 	vap->va_nlink = vp->v_count;	/* number of references to file */
328 	vap->va_size = (u_offset_t)pp->port_queue.portq_nent; /* file size */
329 	vap->va_atime = pp->port_ctime;	/* time of last access */
330 	vap->va_mtime = pp->port_ctime;	/* time of last modification */
331 	vap->va_ctime = pp->port_ctime;	/* time file ``created'' */
332 	vap->va_rdev = portdev;		/* device the file represents */
333 	vap->va_blksize = 0;		/* fundamental block size */
334 	vap->va_nblocks = (fsblkcnt64_t)0;	/* # of blocks allocated */
335 	vap->va_seq = 0;		/* sequence number */
336 
337 	return (0);
338 }
339 
340 /*
341  * Destroy the port.
342  */
343 /* ARGSUSED */
344 static void
port_inactive(struct vnode * vp,cred_t * cr,caller_context_t * ct)345 port_inactive(struct vnode *vp, cred_t *cr, caller_context_t *ct)
346 {
347 	port_t 	*pp = VTOEP(vp);
348 	extern 	port_kstat_t port_kstat;
349 
350 	mutex_enter(&port_control.pc_mutex);
351 	port_control.pc_nents--;
352 	curproc->p_portcnt--;
353 	port_kstat.pks_ports.value.ui32--;
354 	mutex_exit(&port_control.pc_mutex);
355 	vn_free(vp);
356 	mutex_destroy(&pp->port_mutex);
357 	mutex_destroy(&pp->port_queue.portq_mutex);
358 	mutex_destroy(&pp->port_queue.portq_source_mutex);
359 	kmem_free(pp, sizeof (port_t));
360 }
361 
362 /* ARGSUSED */
363 static int
port_access(struct vnode * vp,int mode,int flags,cred_t * cr,caller_context_t * ct)364 port_access(struct vnode *vp, int mode, int flags, cred_t *cr,
365     caller_context_t *ct)
366 {
367 	return (0);
368 }
369 
370 /* ARGSUSED */
371 static int
port_realvp(vnode_t * vp,vnode_t ** vpp,caller_context_t * ct)372 port_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct)
373 {
374 	*vpp = vp;
375 	return (0);
376 }
377