xref: /freebsd/sys/dev/usb/misc/udbp.c (revision 526e1dc1c0d052b9d2a6cd6da7a16eb09c971c54)
1 /*-
2  * Copyright (c) 1996-2000 Whistle Communications, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of author nor the names of its
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY NICK HIBMA AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  *
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 /* Driver for arbitrary double bulk pipe devices.
35  * The driver assumes that there will be the same driver on the other side.
36  *
37  * XXX Some more information on what the framing of the IP packets looks like.
38  *
39  * To take full advantage of bulk transmission, packets should be chosen
40  * between 1k and 5k in size (1k to make sure the sending side starts
41  * streaming, and <5k to avoid overflowing the system with small TDs).
42  */
43 
44 
45 /* probe/attach/detach:
46  *  Connect the driver to the hardware and netgraph
47  *
48  *  The reason we submit a bulk in transfer is that USB does not know about
49  *  interrupts. The bulk transfer continuously polls the device for data.
50  *  While the device has no data available, the device NAKs the TDs. As soon
51  *  as there is data, the transfer happens and the data comes flowing in.
52  *
53  *  In case you were wondering, interrupt transfers happen exactly that way.
54  *  It therefore doesn't make sense to use the interrupt pipe to signal
55  *  'data ready' and then schedule a bulk transfer to fetch it. That would
56  *  incur a 2ms delay at least, without reducing bandwidth requirements.
57  *
58  */
59 
60 #include <sys/stdint.h>
61 #include <sys/stddef.h>
62 #include <sys/param.h>
63 #include <sys/queue.h>
64 #include <sys/types.h>
65 #include <sys/systm.h>
66 #include <sys/kernel.h>
67 #include <sys/bus.h>
68 #include <sys/module.h>
69 #include <sys/lock.h>
70 #include <sys/mutex.h>
71 #include <sys/condvar.h>
72 #include <sys/sysctl.h>
73 #include <sys/sx.h>
74 #include <sys/unistd.h>
75 #include <sys/callout.h>
76 #include <sys/malloc.h>
77 #include <sys/priv.h>
78 
79 #include <dev/usb/usb.h>
80 #include <dev/usb/usbdi.h>
81 #include <dev/usb/usbdi_util.h>
82 #include "usbdevs.h"
83 
84 #define	USB_DEBUG_VAR udbp_debug
85 #include <dev/usb/usb_debug.h>
86 
87 #include <sys/mbuf.h>
88 
89 #include <netgraph/ng_message.h>
90 #include <netgraph/netgraph.h>
91 #include <netgraph/ng_parse.h>
92 #include <netgraph/bluetooth/include/ng_bluetooth.h>
93 
94 #include <dev/usb/misc/udbp.h>
95 
96 #ifdef USB_DEBUG
97 static int udbp_debug = 0;
98 
99 static SYSCTL_NODE(_hw_usb, OID_AUTO, udbp, CTLFLAG_RW, 0, "USB udbp");
100 SYSCTL_INT(_hw_usb_udbp, OID_AUTO, debug, CTLFLAG_RW,
101     &udbp_debug, 0, "udbp debug level");
102 #endif
103 
104 #define	UDBP_TIMEOUT	2000		/* timeout on outbound transfers, in
105 					 * msecs */
106 #define	UDBP_BUFFERSIZE	MCLBYTES	/* maximum number of bytes in one
107 					 * transfer */
108 #define	UDBP_T_WR       0
109 #define	UDBP_T_RD       1
110 #define	UDBP_T_WR_CS    2
111 #define	UDBP_T_RD_CS    3
112 #define	UDBP_T_MAX      4
113 #define	UDBP_Q_MAXLEN   50
114 
115 struct udbp_softc {
116 
117 	struct mtx sc_mtx;
118 	struct ng_bt_mbufq sc_xmitq_hipri;	/* hi-priority transmit queue */
119 	struct ng_bt_mbufq sc_xmitq;	/* low-priority transmit queue */
120 
121 	struct usb_xfer *sc_xfer[UDBP_T_MAX];
122 	node_p	sc_node;		/* back pointer to node */
123 	hook_p	sc_hook;		/* pointer to the hook */
124 	struct mbuf *sc_bulk_in_buffer;
125 
126 	uint32_t sc_packets_in;		/* packets in from downstream */
127 	uint32_t sc_packets_out;	/* packets out towards downstream */
128 
129 	uint8_t	sc_flags;
130 #define	UDBP_FLAG_READ_STALL    0x01	/* read transfer stalled */
131 #define	UDBP_FLAG_WRITE_STALL   0x02	/* write transfer stalled */
132 
133 	uint8_t	sc_name[16];
134 };
135 
136 /* prototypes */
137 
138 static int udbp_modload(module_t mod, int event, void *data);
139 
140 static device_probe_t udbp_probe;
141 static device_attach_t udbp_attach;
142 static device_detach_t udbp_detach;
143 
144 static usb_callback_t udbp_bulk_read_callback;
145 static usb_callback_t udbp_bulk_read_clear_stall_callback;
146 static usb_callback_t udbp_bulk_write_callback;
147 static usb_callback_t udbp_bulk_write_clear_stall_callback;
148 
149 static void	udbp_bulk_read_complete(node_p, hook_p, void *, int);
150 
151 static ng_constructor_t	ng_udbp_constructor;
152 static ng_rcvmsg_t	ng_udbp_rcvmsg;
153 static ng_shutdown_t	ng_udbp_rmnode;
154 static ng_newhook_t	ng_udbp_newhook;
155 static ng_connect_t	ng_udbp_connect;
156 static ng_rcvdata_t	ng_udbp_rcvdata;
157 static ng_disconnect_t	ng_udbp_disconnect;
158 
159 /* Parse type for struct ngudbpstat */
160 static const struct ng_parse_struct_field
161 	ng_udbp_stat_type_fields[] = NG_UDBP_STATS_TYPE_INFO;
162 
163 static const struct ng_parse_type ng_udbp_stat_type = {
164 	&ng_parse_struct_type,
165 	&ng_udbp_stat_type_fields
166 };
167 
168 /* List of commands and how to convert arguments to/from ASCII */
169 static const struct ng_cmdlist ng_udbp_cmdlist[] = {
170 	{
171 		NGM_UDBP_COOKIE,
172 		NGM_UDBP_GET_STATUS,
173 		"getstatus",
174 		NULL,
175 		&ng_udbp_stat_type,
176 	},
177 	{
178 		NGM_UDBP_COOKIE,
179 		NGM_UDBP_SET_FLAG,
180 		"setflag",
181 		&ng_parse_int32_type,
182 		NULL
183 	},
184 	{0}
185 };
186 
187 /* Netgraph node type descriptor */
188 static struct ng_type ng_udbp_typestruct = {
189 	.version = NG_ABI_VERSION,
190 	.name = NG_UDBP_NODE_TYPE,
191 	.constructor = ng_udbp_constructor,
192 	.rcvmsg = ng_udbp_rcvmsg,
193 	.shutdown = ng_udbp_rmnode,
194 	.newhook = ng_udbp_newhook,
195 	.connect = ng_udbp_connect,
196 	.rcvdata = ng_udbp_rcvdata,
197 	.disconnect = ng_udbp_disconnect,
198 	.cmdlist = ng_udbp_cmdlist,
199 };
200 
201 /* USB config */
202 static const struct usb_config udbp_config[UDBP_T_MAX] = {
203 
204 	[UDBP_T_WR] = {
205 		.type = UE_BULK,
206 		.endpoint = UE_ADDR_ANY,
207 		.direction = UE_DIR_OUT,
208 		.bufsize = UDBP_BUFFERSIZE,
209 		.flags = {.pipe_bof = 1,.force_short_xfer = 1,},
210 		.callback = &udbp_bulk_write_callback,
211 		.timeout = UDBP_TIMEOUT,
212 	},
213 
214 	[UDBP_T_RD] = {
215 		.type = UE_BULK,
216 		.endpoint = UE_ADDR_ANY,
217 		.direction = UE_DIR_IN,
218 		.bufsize = UDBP_BUFFERSIZE,
219 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
220 		.callback = &udbp_bulk_read_callback,
221 	},
222 
223 	[UDBP_T_WR_CS] = {
224 		.type = UE_CONTROL,
225 		.endpoint = 0x00,	/* Control pipe */
226 		.direction = UE_DIR_ANY,
227 		.bufsize = sizeof(struct usb_device_request),
228 		.callback = &udbp_bulk_write_clear_stall_callback,
229 		.timeout = 1000,	/* 1 second */
230 		.interval = 50,	/* 50ms */
231 	},
232 
233 	[UDBP_T_RD_CS] = {
234 		.type = UE_CONTROL,
235 		.endpoint = 0x00,	/* Control pipe */
236 		.direction = UE_DIR_ANY,
237 		.bufsize = sizeof(struct usb_device_request),
238 		.callback = &udbp_bulk_read_clear_stall_callback,
239 		.timeout = 1000,	/* 1 second */
240 		.interval = 50,	/* 50ms */
241 	},
242 };
243 
244 static devclass_t udbp_devclass;
245 
246 static device_method_t udbp_methods[] = {
247 	/* Device interface */
248 	DEVMETHOD(device_probe, udbp_probe),
249 	DEVMETHOD(device_attach, udbp_attach),
250 	DEVMETHOD(device_detach, udbp_detach),
251 	{0, 0}
252 };
253 
254 static driver_t udbp_driver = {
255 	.name = "udbp",
256 	.methods = udbp_methods,
257 	.size = sizeof(struct udbp_softc),
258 };
259 
260 DRIVER_MODULE(udbp, uhub, udbp_driver, udbp_devclass, udbp_modload, 0);
261 MODULE_DEPEND(udbp, netgraph, NG_ABI_VERSION, NG_ABI_VERSION, NG_ABI_VERSION);
262 MODULE_DEPEND(udbp, usb, 1, 1, 1);
263 MODULE_VERSION(udbp, 1);
264 
265 static int
266 udbp_modload(module_t mod, int event, void *data)
267 {
268 	int error;
269 
270 	switch (event) {
271 	case MOD_LOAD:
272 		error = ng_newtype(&ng_udbp_typestruct);
273 		if (error != 0) {
274 			printf("%s: Could not register "
275 			    "Netgraph node type, error=%d\n",
276 			    NG_UDBP_NODE_TYPE, error);
277 		}
278 		break;
279 
280 	case MOD_UNLOAD:
281 		error = ng_rmtype(&ng_udbp_typestruct);
282 		break;
283 
284 	default:
285 		error = EOPNOTSUPP;
286 		break;
287 	}
288 	return (error);
289 }
290 
291 static const STRUCT_USB_HOST_ID udbp_devs[] = {
292 	{USB_VPI(USB_VENDOR_NETCHIP, USB_PRODUCT_NETCHIP_TURBOCONNECT, 0)},
293 	{USB_VPI(USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_PL2301, 0)},
294 	{USB_VPI(USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_PL2302, 0)},
295 	{USB_VPI(USB_VENDOR_ANCHOR, USB_PRODUCT_ANCHOR_EZLINK, 0)},
296 	{USB_VPI(USB_VENDOR_GENESYS, USB_PRODUCT_GENESYS_GL620USB, 0)},
297 };
298 
299 static int
300 udbp_probe(device_t dev)
301 {
302 	struct usb_attach_arg *uaa = device_get_ivars(dev);
303 
304 	if (uaa->usb_mode != USB_MODE_HOST)
305 		return (ENXIO);
306 	if (uaa->info.bConfigIndex != 0)
307 		return (ENXIO);
308 	if (uaa->info.bIfaceIndex != 0)
309 		return (ENXIO);
310 
311 	return (usbd_lookup_id_by_uaa(udbp_devs, sizeof(udbp_devs), uaa));
312 }
313 
314 static int
315 udbp_attach(device_t dev)
316 {
317 	struct usb_attach_arg *uaa = device_get_ivars(dev);
318 	struct udbp_softc *sc = device_get_softc(dev);
319 	int error;
320 
321 	device_set_usb_desc(dev);
322 
323 	snprintf(sc->sc_name, sizeof(sc->sc_name),
324 	    "%s", device_get_nameunit(dev));
325 
326 	mtx_init(&sc->sc_mtx, "udbp lock", NULL, MTX_DEF | MTX_RECURSE);
327 
328 	error = usbd_transfer_setup(uaa->device, &uaa->info.bIfaceIndex,
329 	    sc->sc_xfer, udbp_config, UDBP_T_MAX, sc, &sc->sc_mtx);
330 	if (error) {
331 		DPRINTF("error=%s\n", usbd_errstr(error));
332 		goto detach;
333 	}
334 	NG_BT_MBUFQ_INIT(&sc->sc_xmitq, UDBP_Q_MAXLEN);
335 
336 	NG_BT_MBUFQ_INIT(&sc->sc_xmitq_hipri, UDBP_Q_MAXLEN);
337 
338 	/* create Netgraph node */
339 
340 	if (ng_make_node_common(&ng_udbp_typestruct, &sc->sc_node) != 0) {
341 		printf("%s: Could not create Netgraph node\n",
342 		    sc->sc_name);
343 		sc->sc_node = NULL;
344 		goto detach;
345 	}
346 	/* name node */
347 
348 	if (ng_name_node(sc->sc_node, sc->sc_name) != 0) {
349 		printf("%s: Could not name node\n",
350 		    sc->sc_name);
351 		NG_NODE_UNREF(sc->sc_node);
352 		sc->sc_node = NULL;
353 		goto detach;
354 	}
355 	NG_NODE_SET_PRIVATE(sc->sc_node, sc);
356 
357 	/* the device is now operational */
358 
359 	return (0);			/* success */
360 
361 detach:
362 	udbp_detach(dev);
363 	return (ENOMEM);		/* failure */
364 }
365 
366 static int
367 udbp_detach(device_t dev)
368 {
369 	struct udbp_softc *sc = device_get_softc(dev);
370 
371 	/* destroy Netgraph node */
372 
373 	if (sc->sc_node != NULL) {
374 		NG_NODE_SET_PRIVATE(sc->sc_node, NULL);
375 		ng_rmnode_self(sc->sc_node);
376 		sc->sc_node = NULL;
377 	}
378 	/* free USB transfers, if any */
379 
380 	usbd_transfer_unsetup(sc->sc_xfer, UDBP_T_MAX);
381 
382 	mtx_destroy(&sc->sc_mtx);
383 
384 	/* destroy queues */
385 
386 	NG_BT_MBUFQ_DESTROY(&sc->sc_xmitq);
387 	NG_BT_MBUFQ_DESTROY(&sc->sc_xmitq_hipri);
388 
389 	/* extra check */
390 
391 	if (sc->sc_bulk_in_buffer) {
392 		m_freem(sc->sc_bulk_in_buffer);
393 		sc->sc_bulk_in_buffer = NULL;
394 	}
395 	return (0);			/* success */
396 }
397 
398 static void
399 udbp_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error)
400 {
401 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
402 	struct usb_page_cache *pc;
403 	struct mbuf *m;
404 	int actlen;
405 
406 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
407 
408 	switch (USB_GET_STATE(xfer)) {
409 	case USB_ST_TRANSFERRED:
410 
411 		/* allocate new mbuf */
412 
413 		MGETHDR(m, M_NOWAIT, MT_DATA);
414 
415 		if (m == NULL) {
416 			goto tr_setup;
417 		}
418 		MCLGET(m, M_NOWAIT);
419 
420 		if (!(m->m_flags & M_EXT)) {
421 			m_freem(m);
422 			goto tr_setup;
423 		}
424 		m->m_pkthdr.len = m->m_len = actlen;
425 
426 		pc = usbd_xfer_get_frame(xfer, 0);
427 		usbd_copy_out(pc, 0, m->m_data, actlen);
428 
429 		sc->sc_bulk_in_buffer = m;
430 
431 		DPRINTF("received package %d bytes\n", actlen);
432 
433 	case USB_ST_SETUP:
434 tr_setup:
435 		if (sc->sc_bulk_in_buffer) {
436 			ng_send_fn(sc->sc_node, NULL, &udbp_bulk_read_complete, NULL, 0);
437 			return;
438 		}
439 		if (sc->sc_flags & UDBP_FLAG_READ_STALL) {
440 			usbd_transfer_start(sc->sc_xfer[UDBP_T_RD_CS]);
441 			return;
442 		}
443 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
444 		usbd_transfer_submit(xfer);
445 		return;
446 
447 	default:			/* Error */
448 		if (error != USB_ERR_CANCELLED) {
449 			/* try to clear stall first */
450 			sc->sc_flags |= UDBP_FLAG_READ_STALL;
451 			usbd_transfer_start(sc->sc_xfer[UDBP_T_RD_CS]);
452 		}
453 		return;
454 
455 	}
456 }
457 
458 static void
459 udbp_bulk_read_clear_stall_callback(struct usb_xfer *xfer, usb_error_t error)
460 {
461 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
462 	struct usb_xfer *xfer_other = sc->sc_xfer[UDBP_T_RD];
463 
464 	if (usbd_clear_stall_callback(xfer, xfer_other)) {
465 		DPRINTF("stall cleared\n");
466 		sc->sc_flags &= ~UDBP_FLAG_READ_STALL;
467 		usbd_transfer_start(xfer_other);
468 	}
469 }
470 
471 static void
472 udbp_bulk_read_complete(node_p node, hook_p hook, void *arg1, int arg2)
473 {
474 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
475 	struct mbuf *m;
476 	int error;
477 
478 	if (sc == NULL) {
479 		return;
480 	}
481 	mtx_lock(&sc->sc_mtx);
482 
483 	m = sc->sc_bulk_in_buffer;
484 
485 	if (m) {
486 
487 		sc->sc_bulk_in_buffer = NULL;
488 
489 		if ((sc->sc_hook == NULL) ||
490 		    NG_HOOK_NOT_VALID(sc->sc_hook)) {
491 			DPRINTF("No upstream hook\n");
492 			goto done;
493 		}
494 		sc->sc_packets_in++;
495 
496 		NG_SEND_DATA_ONLY(error, sc->sc_hook, m);
497 
498 		m = NULL;
499 	}
500 done:
501 	if (m) {
502 		m_freem(m);
503 	}
504 	/* start USB bulk-in transfer, if not already started */
505 
506 	usbd_transfer_start(sc->sc_xfer[UDBP_T_RD]);
507 
508 	mtx_unlock(&sc->sc_mtx);
509 }
510 
511 static void
512 udbp_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
513 {
514 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
515 	struct usb_page_cache *pc;
516 	struct mbuf *m;
517 
518 	switch (USB_GET_STATE(xfer)) {
519 	case USB_ST_TRANSFERRED:
520 
521 		sc->sc_packets_out++;
522 
523 	case USB_ST_SETUP:
524 		if (sc->sc_flags & UDBP_FLAG_WRITE_STALL) {
525 			usbd_transfer_start(sc->sc_xfer[UDBP_T_WR_CS]);
526 			return;
527 		}
528 		/* get next mbuf, if any */
529 
530 		NG_BT_MBUFQ_DEQUEUE(&sc->sc_xmitq_hipri, m);
531 		if (m == NULL) {
532 			NG_BT_MBUFQ_DEQUEUE(&sc->sc_xmitq, m);
533 			if (m == NULL) {
534 				DPRINTF("Data queue is empty\n");
535 				return;
536 			}
537 		}
538 		if (m->m_pkthdr.len > MCLBYTES) {
539 			DPRINTF("truncating large packet "
540 			    "from %d to %d bytes\n", m->m_pkthdr.len,
541 			    MCLBYTES);
542 			m->m_pkthdr.len = MCLBYTES;
543 		}
544 		pc = usbd_xfer_get_frame(xfer, 0);
545 		usbd_m_copy_in(pc, 0, m, 0, m->m_pkthdr.len);
546 
547 		usbd_xfer_set_frame_len(xfer, 0, m->m_pkthdr.len);
548 
549 		DPRINTF("packet out: %d bytes\n", m->m_pkthdr.len);
550 
551 		m_freem(m);
552 
553 		usbd_transfer_submit(xfer);
554 		return;
555 
556 	default:			/* Error */
557 		if (error != USB_ERR_CANCELLED) {
558 			/* try to clear stall first */
559 			sc->sc_flags |= UDBP_FLAG_WRITE_STALL;
560 			usbd_transfer_start(sc->sc_xfer[UDBP_T_WR_CS]);
561 		}
562 		return;
563 
564 	}
565 }
566 
567 static void
568 udbp_bulk_write_clear_stall_callback(struct usb_xfer *xfer, usb_error_t error)
569 {
570 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
571 	struct usb_xfer *xfer_other = sc->sc_xfer[UDBP_T_WR];
572 
573 	if (usbd_clear_stall_callback(xfer, xfer_other)) {
574 		DPRINTF("stall cleared\n");
575 		sc->sc_flags &= ~UDBP_FLAG_WRITE_STALL;
576 		usbd_transfer_start(xfer_other);
577 	}
578 }
579 
580 /***********************************************************************
581  * Start of Netgraph methods
582  **********************************************************************/
583 
584 /*
585  * If this is a device node so this work is done in the attach()
586  * routine and the constructor will return EINVAL as you should not be able
587  * to create nodes that depend on hardware (unless you can add the hardware :)
588  */
589 static int
590 ng_udbp_constructor(node_p node)
591 {
592 	return (EINVAL);
593 }
594 
595 /*
596  * Give our ok for a hook to be added...
597  * If we are not running this might kick a device into life.
598  * Possibly decode information out of the hook name.
599  * Add the hook's private info to the hook structure.
600  * (if we had some). In this example, we assume that there is a
601  * an array of structs, called 'channel' in the private info,
602  * one for each active channel. The private
603  * pointer of each hook points to the appropriate UDBP_hookinfo struct
604  * so that the source of an input packet is easily identified.
605  */
606 static int
607 ng_udbp_newhook(node_p node, hook_p hook, const char *name)
608 {
609 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
610 	int32_t error = 0;
611 
612 	if (strcmp(name, NG_UDBP_HOOK_NAME)) {
613 		return (EINVAL);
614 	}
615 	mtx_lock(&sc->sc_mtx);
616 
617 	if (sc->sc_hook != NULL) {
618 		error = EISCONN;
619 	} else {
620 		sc->sc_hook = hook;
621 		NG_HOOK_SET_PRIVATE(hook, NULL);
622 	}
623 
624 	mtx_unlock(&sc->sc_mtx);
625 
626 	return (error);
627 }
628 
629 /*
630  * Get a netgraph control message.
631  * Check it is one we understand. If needed, send a response.
632  * We could save the address for an async action later, but don't here.
633  * Always free the message.
634  * The response should be in a malloc'd region that the caller can 'free'.
635  * A response is not required.
636  * Theoretically you could respond defferently to old message types if
637  * the cookie in the header didn't match what we consider to be current
638  * (so that old userland programs could continue to work).
639  */
640 static int
641 ng_udbp_rcvmsg(node_p node, item_p item, hook_p lasthook)
642 {
643 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
644 	struct ng_mesg *resp = NULL;
645 	int error = 0;
646 	struct ng_mesg *msg;
647 
648 	NGI_GET_MSG(item, msg);
649 	/* Deal with message according to cookie and command */
650 	switch (msg->header.typecookie) {
651 	case NGM_UDBP_COOKIE:
652 		switch (msg->header.cmd) {
653 		case NGM_UDBP_GET_STATUS:
654 			{
655 				struct ngudbpstat *stats;
656 
657 				NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
658 				if (!resp) {
659 					error = ENOMEM;
660 					break;
661 				}
662 				stats = (struct ngudbpstat *)resp->data;
663 				mtx_lock(&sc->sc_mtx);
664 				stats->packets_in = sc->sc_packets_in;
665 				stats->packets_out = sc->sc_packets_out;
666 				mtx_unlock(&sc->sc_mtx);
667 				break;
668 			}
669 		case NGM_UDBP_SET_FLAG:
670 			if (msg->header.arglen != sizeof(uint32_t)) {
671 				error = EINVAL;
672 				break;
673 			}
674 			DPRINTF("flags = 0x%08x\n",
675 			    *((uint32_t *)msg->data));
676 			break;
677 		default:
678 			error = EINVAL;	/* unknown command */
679 			break;
680 		}
681 		break;
682 	default:
683 		error = EINVAL;		/* unknown cookie type */
684 		break;
685 	}
686 
687 	/* Take care of synchronous response, if any */
688 	NG_RESPOND_MSG(error, node, item, resp);
689 	NG_FREE_MSG(msg);
690 	return (error);
691 }
692 
693 /*
694  * Accept data from the hook and queue it for output.
695  */
696 static int
697 ng_udbp_rcvdata(hook_p hook, item_p item)
698 {
699 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
700 	struct ng_bt_mbufq *queue_ptr;
701 	struct mbuf *m;
702 	struct ng_tag_prio *ptag;
703 	int error;
704 
705 	if (sc == NULL) {
706 		NG_FREE_ITEM(item);
707 		return (EHOSTDOWN);
708 	}
709 	NGI_GET_M(item, m);
710 	NG_FREE_ITEM(item);
711 
712 	/*
713 	 * Now queue the data for when it can be sent
714 	 */
715 	ptag = (void *)m_tag_locate(m, NGM_GENERIC_COOKIE,
716 	    NG_TAG_PRIO, NULL);
717 
718 	if (ptag && (ptag->priority > NG_PRIO_CUTOFF))
719 		queue_ptr = &sc->sc_xmitq_hipri;
720 	else
721 		queue_ptr = &sc->sc_xmitq;
722 
723 	mtx_lock(&sc->sc_mtx);
724 
725 	if (NG_BT_MBUFQ_FULL(queue_ptr)) {
726 		NG_BT_MBUFQ_DROP(queue_ptr);
727 		NG_FREE_M(m);
728 		error = ENOBUFS;
729 	} else {
730 		NG_BT_MBUFQ_ENQUEUE(queue_ptr, m);
731 		/*
732 		 * start bulk-out transfer, if not already started:
733 		 */
734 		usbd_transfer_start(sc->sc_xfer[UDBP_T_WR]);
735 		error = 0;
736 	}
737 
738 	mtx_unlock(&sc->sc_mtx);
739 
740 	return (error);
741 }
742 
743 /*
744  * Do local shutdown processing..
745  * We are a persistant device, we refuse to go away, and
746  * only remove our links and reset ourself.
747  */
748 static int
749 ng_udbp_rmnode(node_p node)
750 {
751 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
752 
753 	/* Let old node go */
754 	NG_NODE_SET_PRIVATE(node, NULL);
755 	NG_NODE_UNREF(node);		/* forget it ever existed */
756 
757 	if (sc == NULL) {
758 		goto done;
759 	}
760 	/* Create Netgraph node */
761 	if (ng_make_node_common(&ng_udbp_typestruct, &sc->sc_node) != 0) {
762 		printf("%s: Could not create Netgraph node\n",
763 		    sc->sc_name);
764 		sc->sc_node = NULL;
765 		goto done;
766 	}
767 	/* Name node */
768 	if (ng_name_node(sc->sc_node, sc->sc_name) != 0) {
769 		printf("%s: Could not name Netgraph node\n",
770 		    sc->sc_name);
771 		NG_NODE_UNREF(sc->sc_node);
772 		sc->sc_node = NULL;
773 		goto done;
774 	}
775 	NG_NODE_SET_PRIVATE(sc->sc_node, sc);
776 
777 done:
778 	if (sc) {
779 		mtx_unlock(&sc->sc_mtx);
780 	}
781 	return (0);
782 }
783 
784 /*
785  * This is called once we've already connected a new hook to the other node.
786  * It gives us a chance to balk at the last minute.
787  */
788 static int
789 ng_udbp_connect(hook_p hook)
790 {
791 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
792 
793 	/* probably not at splnet, force outward queueing */
794 	NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
795 
796 	mtx_lock(&sc->sc_mtx);
797 
798 	sc->sc_flags |= (UDBP_FLAG_READ_STALL |
799 	    UDBP_FLAG_WRITE_STALL);
800 
801 	/* start bulk-in transfer */
802 	usbd_transfer_start(sc->sc_xfer[UDBP_T_RD]);
803 
804 	/* start bulk-out transfer */
805 	usbd_transfer_start(sc->sc_xfer[UDBP_T_WR]);
806 
807 	mtx_unlock(&sc->sc_mtx);
808 
809 	return (0);
810 }
811 
812 /*
813  * Dook disconnection
814  *
815  * For this type, removal of the last link destroys the node
816  */
817 static int
818 ng_udbp_disconnect(hook_p hook)
819 {
820 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
821 	int error = 0;
822 
823 	if (sc != NULL) {
824 
825 		mtx_lock(&sc->sc_mtx);
826 
827 		if (hook != sc->sc_hook) {
828 			error = EINVAL;
829 		} else {
830 
831 			/* stop bulk-in transfer */
832 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_RD_CS]);
833 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_RD]);
834 
835 			/* stop bulk-out transfer */
836 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_WR_CS]);
837 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_WR]);
838 
839 			/* cleanup queues */
840 			NG_BT_MBUFQ_DRAIN(&sc->sc_xmitq);
841 			NG_BT_MBUFQ_DRAIN(&sc->sc_xmitq_hipri);
842 
843 			if (sc->sc_bulk_in_buffer) {
844 				m_freem(sc->sc_bulk_in_buffer);
845 				sc->sc_bulk_in_buffer = NULL;
846 			}
847 			sc->sc_hook = NULL;
848 		}
849 
850 		mtx_unlock(&sc->sc_mtx);
851 	}
852 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
853 	    && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
854 		ng_rmnode_self(NG_HOOK_NODE(hook));
855 
856 	return (error);
857 }
858