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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26
27 /*
28 * Zone Console Driver.
29 *
30 * This driver, derived from the pts/ptm drivers, is the pseudo console driver
31 * for system zones. Its implementation is straightforward. Each instance
32 * of the driver represents a global-zone/local-zone pair (this maps in a
33 * straightforward way to the commonly used terminal notion of "master side"
34 * and "slave side", and we use that terminology throughout).
35 *
36 * Instances of zcons are onlined as children of /pseudo/zconsnex@1/
37 * by zoneadmd in userland, using the devctl framework; thus the driver
38 * does not need to maintain any sort of "admin" node.
39 *
40 * The driver shuttles I/O from master side to slave side and back. In a break
41 * from the pts/ptm semantics, if one side is not open, I/O directed towards
42 * it will simply be discarded. This is so that if zoneadmd is not holding
43 * the master side console open (i.e. it has died somehow), processes in
44 * the zone do not experience any errors and I/O to the console does not
45 * hang.
46 *
47 * TODO: we may want to revisit the other direction; i.e. we may want
48 * zoneadmd to be able to detect whether no zone processes are holding the
49 * console open, an unusual situation.
50 *
51 *
52 *
53 * MASTER SIDE IOCTLS
54 *
55 * The ZC_HOLDSLAVE and ZC_RELEASESLAVE ioctls instruct the master side of the
56 * console to hold and release a reference to the slave side's vnode. They are
57 * meant to be issued by zoneadmd after the console device node is created and
58 * before it is destroyed so that the slave's STREAMS anchor, ptem, is
59 * preserved when ttymon starts popping STREAMS modules from within the
60 * associated zone. This guarantees that the zone console will always have
61 * terminal semantics while the zone is running.
62 *
63 * Here is the issue: the ptem module is anchored in the zone console
64 * (slave side) so that processes within the associated non-global zone will
65 * fail to pop it off, thus ensuring that the slave will retain terminal
66 * semantics. When a process attempts to pop the anchor off of a stream, the
67 * STREAMS subsystem checks whether the calling process' zone is the same as
68 * that of the process that pushed the anchor onto the stream and cancels the
69 * pop if they differ. zoneadmd used to hold an open file descriptor for the
70 * slave while the associated non-global zone ran, thus ensuring that the
71 * slave's STREAMS anchor would never be popped from within the non-global zone
72 * (because zoneadmd runs in the global zone). However, this file descriptor
73 * was removed to make zone console management more robust. sad(7D) is now
74 * used to automatically set up the slave's STREAMS modules when the zone
75 * console is freshly opened within the associated non-global zone. However,
76 * when a process within the non-global zone freshly opens the zone console, the
77 * anchor is pushed from within the non-global zone, making it possible for
78 * processes within the non-global zone (e.g., ttymon) to pop the anchor and
79 * destroy the zone console's terminal semantics.
80 *
81 * One solution is to make the zcons device hold the slave open while the
82 * associated non-global zone runs so that the STREAMS anchor will always be
83 * associated with the global zone. Unfortunately, the slave cannot be opened
84 * from within the zcons driver because the driver is not reentrant: it has
85 * an outer STREAMS perimeter. Therefore, the next best option is for zcons to
86 * provide an ioctl interface to zoneadmd to manage holding and releasing
87 * the slave side of the console. It is sufficient to hold the slave side's
88 * vnode and bump the associated snode's reference count to preserve the slave's
89 * STREAMS configuration while the associated zone runs, so that's what the
90 * ioctls do.
91 *
92 *
93 * ZC_HOLDSLAVE
94 *
95 * This ioctl takes a file descriptor as an argument. It effectively gets a
96 * reference to the slave side's minor node's vnode and bumps the associated
97 * snode's reference count. The vnode reference is stored in the zcons device
98 * node's soft state. This ioctl succeeds if the given file descriptor refers
99 * to the slave side's minor node or if there is already a reference to the
100 * slave side's minor node's vnode in the device's soft state.
101 *
102 *
103 * ZC_RELEASESLAVE
104 *
105 * This ioctl takes a file descriptor as an argument. It effectively releases
106 * the vnode reference stored in the zcons device node's soft state (which was
107 * previously acquired via ZC_HOLDSLAVE) and decrements the reference count of
108 * the snode associated with the vnode. This ioctl succeeds if the given file
109 * descriptor refers to the slave side's minor node or if no reference to the
110 * slave side's minor node's vnode is stored in the device's soft state.
111 *
112 *
113 * Note that the file descriptor arguments for both ioctls must be cast to
114 * integers of pointer width.
115 *
116 * Here's how the dance between zcons and zoneadmd works:
117 *
118 * Zone boot:
119 * 1. While booting the zone, zoneadmd creates an instance of zcons.
120 * 2. zoneadmd opens the master and slave sides of the new zone console
121 * and issues the ZC_HOLDSLAVE ioctl on the master side, passing its
122 * file descriptor for the slave side as the ioctl argument.
123 * 3. zcons holds the slave side's vnode, bumps the snode's reference
124 * count, and stores a pointer to the vnode in the device's soft
125 * state.
126 * 4. zoneadmd closes the master and slave sides and continues to boot
127 * the zone.
128 *
129 * Zone halt:
130 * 1. While halting the zone, zoneadmd opens the master and slave sides
131 * of the zone's console and issues the ZC_RELEASESLAVE ioctl on the
132 * master side, passing its file descriptor for the slave side as the
133 * ioctl argument.
134 * 2. zcons decrements the slave side's snode's reference count, releases
135 * the slave's vnode, and eliminates its reference to the vnode in the
136 * device's soft state.
137 * 3. zoneadmd closes the master and slave sides.
138 * 4. zoneadmd destroys the zcons device and continues to halt the zone.
139 *
140 * It is necessary for zoneadmd to hold the slave open while issuing
141 * ZC_RELEASESLAVE because zcons might otherwise release the last reference to
142 * the slave's vnode. If it does, then specfs will panic because it will expect
143 * that the STREAMS configuration for the vnode was destroyed, which VN_RELE
144 * doesn't do. Forcing zoneadmd to hold the slave open guarantees that zcons
145 * won't release the vnode's last reference. zoneadmd will properly destroy the
146 * vnode and the snode when it closes the file descriptor.
147 *
148 * Technically, any process that can access the master side can issue these
149 * ioctls, but they should be treated as private interfaces for zoneadmd.
150 */
151
152 #include <sys/types.h>
153 #include <sys/cmn_err.h>
154 #include <sys/conf.h>
155 #include <sys/cred.h>
156 #include <sys/ddi.h>
157 #include <sys/debug.h>
158 #include <sys/devops.h>
159 #include <sys/errno.h>
160 #include <sys/file.h>
161 #include <sys/kstr.h>
162 #include <sys/modctl.h>
163 #include <sys/param.h>
164 #include <sys/stat.h>
165 #include <sys/stream.h>
166 #include <sys/stropts.h>
167 #include <sys/strsun.h>
168 #include <sys/sunddi.h>
169 #include <sys/sysmacros.h>
170 #include <sys/systm.h>
171 #include <sys/types.h>
172 #include <sys/zcons.h>
173 #include <sys/vnode.h>
174 #include <sys/fs/snode.h>
175 #include <sys/zone.h>
176
177 static int zc_getinfo(dev_info_t *, ddi_info_cmd_t, void *, void **);
178 static int zc_attach(dev_info_t *, ddi_attach_cmd_t);
179 static int zc_detach(dev_info_t *, ddi_detach_cmd_t);
180
181 static int zc_open(queue_t *, dev_t *, int, int, cred_t *);
182 static int zc_close(queue_t *, int, cred_t *);
183 static void zc_wput(queue_t *, mblk_t *);
184 static void zc_rsrv(queue_t *);
185 static void zc_wsrv(queue_t *);
186
187 /*
188 * The instance number is encoded in the dev_t in the minor number; the lowest
189 * bit of the minor number is used to track the master vs. slave side of the
190 * virtual console. The rest of the bits in the minor number are the instance.
191 */
192 #define ZC_MASTER_MINOR 0
193 #define ZC_SLAVE_MINOR 1
194
195 #define ZC_INSTANCE(x) (getminor((x)) >> 1)
196 #define ZC_NODE(x) (getminor((x)) & 0x01)
197
198 /*
199 * This macro converts a zc_state_t pointer to the associated slave minor node's
200 * dev_t.
201 */
202 #define ZC_STATE_TO_SLAVEDEV(x) (makedevice(ddi_driver_major((x)->zc_devinfo), \
203 (minor_t)(ddi_get_instance((x)->zc_devinfo) << 1 | ZC_SLAVE_MINOR)))
204
205 int zcons_debug = 0;
206 #define DBG(a) if (zcons_debug) cmn_err(CE_NOTE, a)
207 #define DBG1(a, b) if (zcons_debug) cmn_err(CE_NOTE, a, b)
208
209
210 /*
211 * Zone Console Pseudo Terminal Module: stream data structure definitions
212 */
213 static struct module_info zc_info = {
214 31337, /* c0z we r hAx0rs */
215 "zcons",
216 0,
217 INFPSZ,
218 2048,
219 128
220 };
221
222 static struct qinit zc_rinit = {
223 NULL,
224 (int (*)()) zc_rsrv,
225 zc_open,
226 zc_close,
227 NULL,
228 &zc_info,
229 NULL
230 };
231
232 static struct qinit zc_winit = {
233 (int (*)()) zc_wput,
234 (int (*)()) zc_wsrv,
235 NULL,
236 NULL,
237 NULL,
238 &zc_info,
239 NULL
240 };
241
242 static struct streamtab zc_tab_info = {
243 &zc_rinit,
244 &zc_winit,
245 NULL,
246 NULL
247 };
248
249 #define ZC_CONF_FLAG (D_MP | D_MTQPAIR | D_MTOUTPERIM | D_MTOCEXCL)
250
251 /*
252 * this will define (struct cb_ops cb_zc_ops) and (struct dev_ops zc_ops)
253 */
254 DDI_DEFINE_STREAM_OPS(zc_ops, nulldev, nulldev, zc_attach, zc_detach, nodev, \
255 zc_getinfo, ZC_CONF_FLAG, &zc_tab_info, ddi_quiesce_not_needed);
256
257 /*
258 * Module linkage information for the kernel.
259 */
260
261 static struct modldrv modldrv = {
262 &mod_driverops, /* Type of module (this is a pseudo driver) */
263 "Zone console driver", /* description of module */
264 &zc_ops /* driver ops */
265 };
266
267 static struct modlinkage modlinkage = {
268 MODREV_1,
269 { &modldrv,
270 NULL }
271 };
272
273 typedef struct zc_state {
274 dev_info_t *zc_devinfo;
275 queue_t *zc_master_rdq;
276 queue_t *zc_slave_rdq;
277 vnode_t *zc_slave_vnode;
278 int zc_state;
279 } zc_state_t;
280
281 #define ZC_STATE_MOPEN 0x01
282 #define ZC_STATE_SOPEN 0x02
283
284 static void *zc_soft_state;
285
286 /*
287 * List of STREAMS modules that should be pushed onto every slave instance.
288 */
289 static char *zcons_mods[] = {
290 "ptem",
291 "ldterm",
292 "ttcompat",
293 NULL
294 };
295
296 int
297 _init(void)
298 {
299 int err;
300
301 if ((err = ddi_soft_state_init(&zc_soft_state,
302 sizeof (zc_state_t), 0)) != 0) {
303 return (err);
304 }
305
306 if ((err = mod_install(&modlinkage)) != 0)
307 ddi_soft_state_fini(zc_soft_state);
308
309 return (err);
310 }
311
312
313 int
314 _fini(void)
315 {
316 int err;
317
318 if ((err = mod_remove(&modlinkage)) != 0) {
319 return (err);
320 }
321
322 ddi_soft_state_fini(&zc_soft_state);
323 return (0);
324 }
325
326 int
327 _info(struct modinfo *modinfop)
328 {
329 return (mod_info(&modlinkage, modinfop));
330 }
331
332 static int
333 zc_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
334 {
335 zc_state_t *zcs;
336 int instance;
337
338 if (cmd != DDI_ATTACH)
339 return (DDI_FAILURE);
340
341 instance = ddi_get_instance(dip);
342 if (ddi_soft_state_zalloc(zc_soft_state, instance) != DDI_SUCCESS)
343 return (DDI_FAILURE);
344
345 /*
346 * Create the master and slave minor nodes.
347 */
348 if ((ddi_create_minor_node(dip, ZCONS_SLAVE_NAME, S_IFCHR,
349 instance << 1 | ZC_SLAVE_MINOR, DDI_PSEUDO, 0) == DDI_FAILURE) ||
350 (ddi_create_minor_node(dip, ZCONS_MASTER_NAME, S_IFCHR,
351 instance << 1 | ZC_MASTER_MINOR, DDI_PSEUDO, 0) == DDI_FAILURE)) {
352 ddi_remove_minor_node(dip, NULL);
353 ddi_soft_state_free(zc_soft_state, instance);
354 return (DDI_FAILURE);
355 }
356
357 VERIFY((zcs = ddi_get_soft_state(zc_soft_state, instance)) != NULL);
358 zcs->zc_devinfo = dip;
359 return (DDI_SUCCESS);
360 }
361
362 static int
363 zc_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
364 {
365 zc_state_t *zcs;
366 int instance;
367
368 if (cmd != DDI_DETACH)
369 return (DDI_FAILURE);
370
371 instance = ddi_get_instance(dip);
372 if ((zcs = ddi_get_soft_state(zc_soft_state, instance)) == NULL)
373 return (DDI_FAILURE);
374
375 if ((zcs->zc_state & ZC_STATE_MOPEN) ||
376 (zcs->zc_state & ZC_STATE_SOPEN)) {
377 DBG1("zc_detach: device (dip=%p) still open\n", (void *)dip);
378 return (DDI_FAILURE);
379 }
380
381 ddi_remove_minor_node(dip, NULL);
382 ddi_soft_state_free(zc_soft_state, instance);
383
384 return (DDI_SUCCESS);
385 }
386
387 /*
388 * zc_getinfo()
389 * getinfo(9e) entrypoint.
390 */
391 /*ARGSUSED*/
392 static int
393 zc_getinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
394 {
395 zc_state_t *zcs;
396 int instance = ZC_INSTANCE((dev_t)arg);
397
398 switch (infocmd) {
399 case DDI_INFO_DEVT2DEVINFO:
400 if ((zcs = ddi_get_soft_state(zc_soft_state, instance)) == NULL)
401 return (DDI_FAILURE);
402 *result = zcs->zc_devinfo;
403 return (DDI_SUCCESS);
404 case DDI_INFO_DEVT2INSTANCE:
405 *result = (void *)(uintptr_t)instance;
406 return (DDI_SUCCESS);
407 }
408 return (DDI_FAILURE);
409 }
410
411 /*
412 * Return the equivalent queue from the other side of the relationship.
413 * e.g.: given the slave's write queue, return the master's write queue.
414 */
415 static queue_t *
416 zc_switch(queue_t *qp)
417 {
418 zc_state_t *zcs = qp->q_ptr;
419 ASSERT(zcs != NULL);
420
421 if (qp == zcs->zc_master_rdq)
422 return (zcs->zc_slave_rdq);
423 else if (OTHERQ(qp) == zcs->zc_master_rdq && zcs->zc_slave_rdq != NULL)
424 return (OTHERQ(zcs->zc_slave_rdq));
425 else if (qp == zcs->zc_slave_rdq)
426 return (zcs->zc_master_rdq);
427 else if (OTHERQ(qp) == zcs->zc_slave_rdq && zcs->zc_master_rdq != NULL)
428 return (OTHERQ(zcs->zc_master_rdq));
429 else
430 return (NULL);
431 }
432
433 /*
434 * For debugging and outputting messages. Returns the name of the side of
435 * the relationship associated with this queue.
436 */
437 static const char *
438 zc_side(queue_t *qp)
439 {
440 zc_state_t *zcs = qp->q_ptr;
441 ASSERT(zcs != NULL);
442
443 if (qp == zcs->zc_master_rdq ||
444 OTHERQ(qp) == zcs->zc_master_rdq) {
445 return ("master");
446 }
447 ASSERT(qp == zcs->zc_slave_rdq || OTHERQ(qp) == zcs->zc_slave_rdq);
448 return ("slave");
449 }
450
451 /*ARGSUSED*/
452 static int
453 zc_master_open(zc_state_t *zcs,
454 queue_t *rqp, /* pointer to the read side queue */
455 dev_t *devp, /* pointer to stream tail's dev */
456 int oflag, /* the user open(2) supplied flags */
457 int sflag, /* open state flag */
458 cred_t *credp) /* credentials */
459 {
460 mblk_t *mop;
461 struct stroptions *sop;
462
463 /*
464 * Enforce exclusivity on the master side; the only consumer should
465 * be the zoneadmd for the zone.
466 */
467 if ((zcs->zc_state & ZC_STATE_MOPEN) != 0)
468 return (EBUSY);
469
470 if ((mop = allocb(sizeof (struct stroptions), BPRI_MED)) == NULL) {
471 DBG("zc_master_open(): mop allocation failed\n");
472 return (ENOMEM);
473 }
474
475 zcs->zc_state |= ZC_STATE_MOPEN;
476
477 /*
478 * q_ptr stores driver private data; stash the soft state data on both
479 * read and write sides of the queue.
480 */
481 WR(rqp)->q_ptr = rqp->q_ptr = zcs;
482 qprocson(rqp);
483
484 /*
485 * Following qprocson(), the master side is fully plumbed into the
486 * STREAM and may send/receive messages. Setting zcs->zc_master_rdq
487 * will allow the slave to send messages to us (the master).
488 * This cannot occur before qprocson() because the master is not
489 * ready to process them until that point.
490 */
491 zcs->zc_master_rdq = rqp;
492
493 /*
494 * set up hi/lo water marks on stream head read queue and add
495 * controlling tty as needed.
496 */
497 mop->b_datap->db_type = M_SETOPTS;
498 mop->b_wptr += sizeof (struct stroptions);
499 sop = (struct stroptions *)(void *)mop->b_rptr;
500 if (oflag & FNOCTTY)
501 sop->so_flags = SO_HIWAT | SO_LOWAT;
502 else
503 sop->so_flags = SO_HIWAT | SO_LOWAT | SO_ISTTY;
504 sop->so_hiwat = 512;
505 sop->so_lowat = 256;
506 putnext(rqp, mop);
507
508 return (0);
509 }
510
511 /*ARGSUSED*/
512 static int
513 zc_slave_open(zc_state_t *zcs,
514 queue_t *rqp, /* pointer to the read side queue */
515 dev_t *devp, /* pointer to stream tail's dev */
516 int oflag, /* the user open(2) supplied flags */
517 int sflag, /* open state flag */
518 cred_t *credp) /* credentials */
519 {
520 mblk_t *mop;
521 struct stroptions *sop;
522 major_t major;
523 minor_t minor;
524 minor_t lastminor;
525 uint_t anchorindex;
526
527 /*
528 * The slave side can be opened as many times as needed.
529 */
530 if ((zcs->zc_state & ZC_STATE_SOPEN) != 0) {
531 ASSERT((rqp != NULL) && (WR(rqp)->q_ptr == zcs));
532 return (0);
533 }
534
535 /*
536 * Set up sad(7D) so that the necessary STREAMS modules will be in
537 * place. A wrinkle is that 'ptem' must be anchored
538 * in place (see streamio(7i)) because we always want the console to
539 * have terminal semantics.
540 */
541 minor = ddi_get_instance(zcs->zc_devinfo) << 1 | ZC_SLAVE_MINOR;
542 major = ddi_driver_major(zcs->zc_devinfo);
543 lastminor = 0;
544 anchorindex = 1;
545 if (kstr_autopush(SET_AUTOPUSH, &major, &minor, &lastminor,
546 &anchorindex, zcons_mods) != 0) {
547 DBG("zc_slave_open(): kstr_autopush() failed\n");
548 return (EIO);
549 }
550
551 if ((mop = allocb(sizeof (struct stroptions), BPRI_MED)) == NULL) {
552 DBG("zc_slave_open(): mop allocation failed\n");
553 return (ENOMEM);
554 }
555
556 zcs->zc_state |= ZC_STATE_SOPEN;
557
558 /*
559 * q_ptr stores driver private data; stash the soft state data on both
560 * read and write sides of the queue.
561 */
562 WR(rqp)->q_ptr = rqp->q_ptr = zcs;
563
564 qprocson(rqp);
565
566 /*
567 * Must follow qprocson(), since we aren't ready to process until then.
568 */
569 zcs->zc_slave_rdq = rqp;
570
571 /*
572 * set up hi/lo water marks on stream head read queue and add
573 * controlling tty as needed.
574 */
575 mop->b_datap->db_type = M_SETOPTS;
576 mop->b_wptr += sizeof (struct stroptions);
577 sop = (struct stroptions *)(void *)mop->b_rptr;
578 sop->so_flags = SO_HIWAT | SO_LOWAT | SO_ISTTY;
579 sop->so_hiwat = 512;
580 sop->so_lowat = 256;
581 putnext(rqp, mop);
582
583 return (0);
584 }
585
586 /*
587 * open(9e) entrypoint; checks sflag, and rejects anything unordinary.
588 */
589 static int
590 zc_open(queue_t *rqp, /* pointer to the read side queue */
591 dev_t *devp, /* pointer to stream tail's dev */
592 int oflag, /* the user open(2) supplied flags */
593 int sflag, /* open state flag */
594 cred_t *credp) /* credentials */
595 {
596 int instance = ZC_INSTANCE(*devp);
597 int ret;
598 zc_state_t *zcs;
599
600 if (sflag != 0)
601 return (EINVAL);
602
603 if ((zcs = ddi_get_soft_state(zc_soft_state, instance)) == NULL)
604 return (ENXIO);
605
606 switch (ZC_NODE(*devp)) {
607 case ZC_MASTER_MINOR:
608 ret = zc_master_open(zcs, rqp, devp, oflag, sflag, credp);
609 break;
610 case ZC_SLAVE_MINOR:
611 ret = zc_slave_open(zcs, rqp, devp, oflag, sflag, credp);
612 break;
613 default:
614 ret = ENXIO;
615 break;
616 }
617
618 return (ret);
619 }
620
621 /*
622 * close(9e) entrypoint.
623 */
624 /*ARGSUSED1*/
625 static int
626 zc_close(queue_t *rqp, int flag, cred_t *credp)
627 {
628 queue_t *wqp;
629 mblk_t *bp;
630 zc_state_t *zcs;
631 major_t major;
632 minor_t minor;
633
634 zcs = (zc_state_t *)rqp->q_ptr;
635
636 if (rqp == zcs->zc_master_rdq) {
637 DBG("Closing master side");
638
639 zcs->zc_master_rdq = NULL;
640 zcs->zc_state &= ~ZC_STATE_MOPEN;
641
642 /*
643 * qenable slave side write queue so that it can flush
644 * its messages as master's read queue is going away
645 */
646 if (zcs->zc_slave_rdq != NULL) {
647 qenable(WR(zcs->zc_slave_rdq));
648 }
649
650 qprocsoff(rqp);
651 WR(rqp)->q_ptr = rqp->q_ptr = NULL;
652
653 } else if (rqp == zcs->zc_slave_rdq) {
654
655 DBG("Closing slave side");
656 zcs->zc_state &= ~ZC_STATE_SOPEN;
657 zcs->zc_slave_rdq = NULL;
658
659 wqp = WR(rqp);
660 while ((bp = getq(wqp)) != NULL) {
661 if (zcs->zc_master_rdq != NULL)
662 putnext(zcs->zc_master_rdq, bp);
663 else if (bp->b_datap->db_type == M_IOCTL)
664 miocnak(wqp, bp, 0, 0);
665 else
666 freemsg(bp);
667 }
668
669 /*
670 * Qenable master side write queue so that it can flush its
671 * messages as slaves's read queue is going away.
672 */
673 if (zcs->zc_master_rdq != NULL)
674 qenable(WR(zcs->zc_master_rdq));
675
676 qprocsoff(rqp);
677 WR(rqp)->q_ptr = rqp->q_ptr = NULL;
678
679 /*
680 * Clear the sad configuration so that reopening doesn't fail
681 * to set up sad configuration.
682 */
683 major = ddi_driver_major(zcs->zc_devinfo);
684 minor = ddi_get_instance(zcs->zc_devinfo) << 1 | ZC_SLAVE_MINOR;
685 (void) kstr_autopush(CLR_AUTOPUSH, &major, &minor, NULL, NULL,
686 NULL);
687 }
688
689 return (0);
690 }
691
692 static void
693 handle_mflush(queue_t *qp, mblk_t *mp)
694 {
695 mblk_t *nmp;
696 DBG1("M_FLUSH on %s side", zc_side(qp));
697
698 if (*mp->b_rptr & FLUSHW) {
699 DBG1("M_FLUSH, FLUSHW, %s side", zc_side(qp));
700 flushq(qp, FLUSHDATA);
701 *mp->b_rptr &= ~FLUSHW;
702 if ((*mp->b_rptr & FLUSHR) == 0) {
703 /*
704 * FLUSHW only. Change to FLUSHR and putnext other side,
705 * then we are done.
706 */
707 *mp->b_rptr |= FLUSHR;
708 if (zc_switch(RD(qp)) != NULL) {
709 putnext(zc_switch(RD(qp)), mp);
710 return;
711 }
712 } else if ((zc_switch(RD(qp)) != NULL) &&
713 (nmp = copyb(mp)) != NULL) {
714 /*
715 * It is a FLUSHRW; we copy the mblk and send
716 * it to the other side, since we still need to use
717 * the mblk in FLUSHR processing, below.
718 */
719 putnext(zc_switch(RD(qp)), nmp);
720 }
721 }
722
723 if (*mp->b_rptr & FLUSHR) {
724 DBG("qreply(qp) turning FLUSHR around\n");
725 qreply(qp, mp);
726 return;
727 }
728 freemsg(mp);
729 }
730
731 /*
732 * wput(9E) is symmetric for master and slave sides, so this handles both
733 * without splitting the codepath. (The only exception to this is the
734 * processing of zcons ioctls, which is restricted to the master side.)
735 *
736 * zc_wput() looks at the other side; if there is no process holding that
737 * side open, it frees the message. This prevents processes from hanging
738 * if no one is holding open the console. Otherwise, it putnext's high
739 * priority messages, putnext's normal messages if possible, and otherwise
740 * enqueues the messages; in the case that something is enqueued, wsrv(9E)
741 * will take care of eventually shuttling I/O to the other side.
742 */
743 static void
744 zc_wput(queue_t *qp, mblk_t *mp)
745 {
746 unsigned char type = mp->b_datap->db_type;
747 zc_state_t *zcs;
748 struct iocblk *iocbp;
749 file_t *slave_filep;
750 struct snode *slave_snodep;
751 int slave_fd;
752
753 ASSERT(qp->q_ptr);
754
755 DBG1("entering zc_wput, %s side", zc_side(qp));
756
757 /*
758 * Process zcons ioctl messages if qp is the master console's write
759 * queue.
760 */
761 zcs = (zc_state_t *)qp->q_ptr;
762 if (zcs->zc_master_rdq != NULL && qp == WR(zcs->zc_master_rdq) &&
763 type == M_IOCTL) {
764 iocbp = (struct iocblk *)(void *)mp->b_rptr;
765 switch (iocbp->ioc_cmd) {
766 case ZC_HOLDSLAVE:
767 /*
768 * Hold the slave's vnode and increment the refcount
769 * of the snode. If the vnode is already held, then
770 * indicate success.
771 */
772 if (iocbp->ioc_count != TRANSPARENT) {
773 miocack(qp, mp, 0, EINVAL);
774 return;
775 }
776 if (zcs->zc_slave_vnode != NULL) {
777 miocack(qp, mp, 0, 0);
778 return;
779 }
780
781 /*
782 * The process that passed the ioctl must be running in
783 * the global zone.
784 */
785 if (curzone != global_zone) {
786 miocack(qp, mp, 0, EINVAL);
787 return;
788 }
789
790 /*
791 * The calling process must pass a file descriptor for
792 * the slave device.
793 */
794 slave_fd =
795 (int)(intptr_t)*(caddr_t *)(void *)mp->b_cont->
796 b_rptr;
797 slave_filep = getf(slave_fd);
798 if (slave_filep == NULL) {
799 miocack(qp, mp, 0, EINVAL);
800 return;
801 }
802 if (ZC_STATE_TO_SLAVEDEV(zcs) !=
803 slave_filep->f_vnode->v_rdev) {
804 releasef(slave_fd);
805 miocack(qp, mp, 0, EINVAL);
806 return;
807 }
808
809 /*
810 * Get a reference to the slave's vnode. Also bump the
811 * reference count on the associated snode.
812 */
813 ASSERT(vn_matchops(slave_filep->f_vnode,
814 spec_getvnodeops()));
815 zcs->zc_slave_vnode = slave_filep->f_vnode;
816 VN_HOLD(zcs->zc_slave_vnode);
817 slave_snodep = VTOCS(zcs->zc_slave_vnode);
818 mutex_enter(&slave_snodep->s_lock);
819 ++slave_snodep->s_count;
820 mutex_exit(&slave_snodep->s_lock);
821 releasef(slave_fd);
822 miocack(qp, mp, 0, 0);
823 return;
824 case ZC_RELEASESLAVE:
825 /*
826 * Release the master's handle on the slave's vnode.
827 * If there isn't a handle for the vnode, then indicate
828 * success.
829 */
830 if (iocbp->ioc_count != TRANSPARENT) {
831 miocack(qp, mp, 0, EINVAL);
832 return;
833 }
834 if (zcs->zc_slave_vnode == NULL) {
835 miocack(qp, mp, 0, 0);
836 return;
837 }
838
839 /*
840 * The process that passed the ioctl must be running in
841 * the global zone.
842 */
843 if (curzone != global_zone) {
844 miocack(qp, mp, 0, EINVAL);
845 return;
846 }
847
848 /*
849 * The process that passed the ioctl must have provided
850 * a file descriptor for the slave device. Make sure
851 * this is correct.
852 */
853 slave_fd =
854 (int)(intptr_t)*(caddr_t *)(void *)mp->b_cont->
855 b_rptr;
856 slave_filep = getf(slave_fd);
857 if (slave_filep == NULL) {
858 miocack(qp, mp, 0, EINVAL);
859 return;
860 }
861 if (zcs->zc_slave_vnode->v_rdev !=
862 slave_filep->f_vnode->v_rdev) {
863 releasef(slave_fd);
864 miocack(qp, mp, 0, EINVAL);
865 return;
866 }
867
868 /*
869 * Decrement the snode's reference count and release the
870 * vnode.
871 */
872 ASSERT(vn_matchops(slave_filep->f_vnode,
873 spec_getvnodeops()));
874 slave_snodep = VTOCS(zcs->zc_slave_vnode);
875 mutex_enter(&slave_snodep->s_lock);
876 --slave_snodep->s_count;
877 mutex_exit(&slave_snodep->s_lock);
878 VN_RELE(zcs->zc_slave_vnode);
879 zcs->zc_slave_vnode = NULL;
880 releasef(slave_fd);
881 miocack(qp, mp, 0, 0);
882 return;
883 default:
884 break;
885 }
886 }
887
888 if (zc_switch(RD(qp)) == NULL) {
889 DBG1("wput to %s side (no one listening)", zc_side(qp));
890 switch (type) {
891 case M_FLUSH:
892 handle_mflush(qp, mp);
893 break;
894 case M_IOCTL:
895 miocnak(qp, mp, 0, 0);
896 break;
897 default:
898 freemsg(mp);
899 break;
900 }
901 return;
902 }
903
904 if (type >= QPCTL) {
905 DBG1("(hipri) wput, %s side", zc_side(qp));
906 switch (type) {
907 case M_READ: /* supposedly from ldterm? */
908 DBG("zc_wput: tossing M_READ\n");
909 freemsg(mp);
910 break;
911 case M_FLUSH:
912 handle_mflush(qp, mp);
913 break;
914 default:
915 /*
916 * Put this to the other side.
917 */
918 ASSERT(zc_switch(RD(qp)) != NULL);
919 putnext(zc_switch(RD(qp)), mp);
920 break;
921 }
922 DBG1("done (hipri) wput, %s side", zc_side(qp));
923 return;
924 }
925
926 /*
927 * Only putnext if there isn't already something in the queue.
928 * otherwise things would wind up out of order.
929 */
930 if (qp->q_first == NULL && bcanputnext(RD(zc_switch(qp)), mp->b_band)) {
931 DBG("wput: putting message to other side\n");
932 putnext(RD(zc_switch(qp)), mp);
933 } else {
934 DBG("wput: putting msg onto queue\n");
935 (void) putq(qp, mp);
936 }
937 DBG1("done wput, %s side", zc_side(qp));
938 }
939
940 /*
941 * rsrv(9E) is symmetric for master and slave, so zc_rsrv() handles both
942 * without splitting up the codepath.
943 *
944 * Enable the write side of the partner. This triggers the partner to send
945 * messages queued on its write side to this queue's read side.
946 */
947 static void
948 zc_rsrv(queue_t *qp)
949 {
950 zc_state_t *zcs;
951 zcs = (zc_state_t *)qp->q_ptr;
952
953 /*
954 * Care must be taken here, as either of the master or slave side
955 * qptr could be NULL.
956 */
957 ASSERT(qp == zcs->zc_master_rdq || qp == zcs->zc_slave_rdq);
958 if (zc_switch(qp) == NULL) {
959 DBG("zc_rsrv: other side isn't listening\n");
960 return;
961 }
962 qenable(WR(zc_switch(qp)));
963 }
964
965 /*
966 * This routine is symmetric for master and slave, so it handles both without
967 * splitting up the codepath.
968 *
969 * If there are messages on this queue that can be sent to the other, send
970 * them via putnext(). Else, if queued messages cannot be sent, leave them
971 * on this queue.
972 */
973 static void
974 zc_wsrv(queue_t *qp)
975 {
976 mblk_t *mp;
977
978 DBG1("zc_wsrv master (%s) side", zc_side(qp));
979
980 /*
981 * Partner has no read queue, so take the data, and throw it away.
982 */
983 if (zc_switch(RD(qp)) == NULL) {
984 DBG("zc_wsrv: other side isn't listening");
985 while ((mp = getq(qp)) != NULL) {
986 if (mp->b_datap->db_type == M_IOCTL)
987 miocnak(qp, mp, 0, 0);
988 else
989 freemsg(mp);
990 }
991 flushq(qp, FLUSHALL);
992 return;
993 }
994
995 /*
996 * while there are messages on this write queue...
997 */
998 while ((mp = getq(qp)) != NULL) {
999 /*
1000 * Due to the way zc_wput is implemented, we should never
1001 * see a control message here.
1002 */
1003 ASSERT(mp->b_datap->db_type < QPCTL);
1004
1005 if (bcanputnext(RD(zc_switch(qp)), mp->b_band)) {
1006 DBG("wsrv: send message to other side\n");
1007 putnext(RD(zc_switch(qp)), mp);
1008 } else {
1009 DBG("wsrv: putting msg back on queue\n");
1010 (void) putbq(qp, mp);
1011 break;
1012 }
1013 }
1014 }