xref: /freebsd/sys/dev/usb/misc/udbp.c (revision bc96366c864c07ef352edb92017357917c75b36c)
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_RWTUN,
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 
252 	DEVMETHOD_END
253 };
254 
255 static driver_t udbp_driver = {
256 	.name = "udbp",
257 	.methods = udbp_methods,
258 	.size = sizeof(struct udbp_softc),
259 };
260 
261 DRIVER_MODULE(udbp, uhub, udbp_driver, udbp_devclass, udbp_modload, 0);
262 MODULE_DEPEND(udbp, netgraph, NG_ABI_VERSION, NG_ABI_VERSION, NG_ABI_VERSION);
263 MODULE_DEPEND(udbp, usb, 1, 1, 1);
264 MODULE_VERSION(udbp, 1);
265 
266 static int
267 udbp_modload(module_t mod, int event, void *data)
268 {
269 	int error;
270 
271 	switch (event) {
272 	case MOD_LOAD:
273 		error = ng_newtype(&ng_udbp_typestruct);
274 		if (error != 0) {
275 			printf("%s: Could not register "
276 			    "Netgraph node type, error=%d\n",
277 			    NG_UDBP_NODE_TYPE, error);
278 		}
279 		break;
280 
281 	case MOD_UNLOAD:
282 		error = ng_rmtype(&ng_udbp_typestruct);
283 		break;
284 
285 	default:
286 		error = EOPNOTSUPP;
287 		break;
288 	}
289 	return (error);
290 }
291 
292 static const STRUCT_USB_HOST_ID udbp_devs[] = {
293 	{USB_VPI(USB_VENDOR_NETCHIP, USB_PRODUCT_NETCHIP_TURBOCONNECT, 0)},
294 	{USB_VPI(USB_VENDOR_NETCHIP, USB_PRODUCT_NETCHIP_GADGETZERO, 0)},
295 	{USB_VPI(USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_PL2301, 0)},
296 	{USB_VPI(USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_PL2302, 0)},
297 	{USB_VPI(USB_VENDOR_ANCHOR, USB_PRODUCT_ANCHOR_EZLINK, 0)},
298 	{USB_VPI(USB_VENDOR_GENESYS, USB_PRODUCT_GENESYS_GL620USB, 0)},
299 };
300 
301 static int
302 udbp_probe(device_t dev)
303 {
304 	struct usb_attach_arg *uaa = device_get_ivars(dev);
305 
306 	if (uaa->usb_mode != USB_MODE_HOST)
307 		return (ENXIO);
308 	if (uaa->info.bConfigIndex != 0)
309 		return (ENXIO);
310 	if (uaa->info.bIfaceIndex != 0)
311 		return (ENXIO);
312 
313 	return (usbd_lookup_id_by_uaa(udbp_devs, sizeof(udbp_devs), uaa));
314 }
315 
316 static int
317 udbp_attach(device_t dev)
318 {
319 	struct usb_attach_arg *uaa = device_get_ivars(dev);
320 	struct udbp_softc *sc = device_get_softc(dev);
321 	int error;
322 
323 	device_set_usb_desc(dev);
324 
325 	snprintf(sc->sc_name, sizeof(sc->sc_name),
326 	    "%s", device_get_nameunit(dev));
327 
328 	mtx_init(&sc->sc_mtx, "udbp lock", NULL, MTX_DEF | MTX_RECURSE);
329 
330 	error = usbd_transfer_setup(uaa->device, &uaa->info.bIfaceIndex,
331 	    sc->sc_xfer, udbp_config, UDBP_T_MAX, sc, &sc->sc_mtx);
332 	if (error) {
333 		DPRINTF("error=%s\n", usbd_errstr(error));
334 		goto detach;
335 	}
336 	NG_BT_MBUFQ_INIT(&sc->sc_xmitq, UDBP_Q_MAXLEN);
337 
338 	NG_BT_MBUFQ_INIT(&sc->sc_xmitq_hipri, UDBP_Q_MAXLEN);
339 
340 	/* create Netgraph node */
341 
342 	if (ng_make_node_common(&ng_udbp_typestruct, &sc->sc_node) != 0) {
343 		printf("%s: Could not create Netgraph node\n",
344 		    sc->sc_name);
345 		sc->sc_node = NULL;
346 		goto detach;
347 	}
348 	/* name node */
349 
350 	if (ng_name_node(sc->sc_node, sc->sc_name) != 0) {
351 		printf("%s: Could not name node\n",
352 		    sc->sc_name);
353 		NG_NODE_UNREF(sc->sc_node);
354 		sc->sc_node = NULL;
355 		goto detach;
356 	}
357 	NG_NODE_SET_PRIVATE(sc->sc_node, sc);
358 
359 	/* the device is now operational */
360 
361 	return (0);			/* success */
362 
363 detach:
364 	udbp_detach(dev);
365 	return (ENOMEM);		/* failure */
366 }
367 
368 static int
369 udbp_detach(device_t dev)
370 {
371 	struct udbp_softc *sc = device_get_softc(dev);
372 
373 	/* destroy Netgraph node */
374 
375 	if (sc->sc_node != NULL) {
376 		NG_NODE_SET_PRIVATE(sc->sc_node, NULL);
377 		ng_rmnode_self(sc->sc_node);
378 		sc->sc_node = NULL;
379 	}
380 	/* free USB transfers, if any */
381 
382 	usbd_transfer_unsetup(sc->sc_xfer, UDBP_T_MAX);
383 
384 	mtx_destroy(&sc->sc_mtx);
385 
386 	/* destroy queues */
387 
388 	NG_BT_MBUFQ_DESTROY(&sc->sc_xmitq);
389 	NG_BT_MBUFQ_DESTROY(&sc->sc_xmitq_hipri);
390 
391 	/* extra check */
392 
393 	if (sc->sc_bulk_in_buffer) {
394 		m_freem(sc->sc_bulk_in_buffer);
395 		sc->sc_bulk_in_buffer = NULL;
396 	}
397 	return (0);			/* success */
398 }
399 
400 static void
401 udbp_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error)
402 {
403 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
404 	struct usb_page_cache *pc;
405 	struct mbuf *m;
406 	int actlen;
407 
408 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
409 
410 	switch (USB_GET_STATE(xfer)) {
411 	case USB_ST_TRANSFERRED:
412 
413 		/* allocate new mbuf */
414 
415 		MGETHDR(m, M_NOWAIT, MT_DATA);
416 
417 		if (m == NULL) {
418 			goto tr_setup;
419 		}
420 
421 		if (!(MCLGET(m, M_NOWAIT))) {
422 			m_freem(m);
423 			goto tr_setup;
424 		}
425 		m->m_pkthdr.len = m->m_len = actlen;
426 
427 		pc = usbd_xfer_get_frame(xfer, 0);
428 		usbd_copy_out(pc, 0, m->m_data, actlen);
429 
430 		sc->sc_bulk_in_buffer = m;
431 
432 		DPRINTF("received package %d bytes\n", actlen);
433 
434 	case USB_ST_SETUP:
435 tr_setup:
436 		if (sc->sc_bulk_in_buffer) {
437 			ng_send_fn(sc->sc_node, NULL, &udbp_bulk_read_complete, NULL, 0);
438 			return;
439 		}
440 		if (sc->sc_flags & UDBP_FLAG_READ_STALL) {
441 			usbd_transfer_start(sc->sc_xfer[UDBP_T_RD_CS]);
442 			return;
443 		}
444 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
445 		usbd_transfer_submit(xfer);
446 		return;
447 
448 	default:			/* Error */
449 		if (error != USB_ERR_CANCELLED) {
450 			/* try to clear stall first */
451 			sc->sc_flags |= UDBP_FLAG_READ_STALL;
452 			usbd_transfer_start(sc->sc_xfer[UDBP_T_RD_CS]);
453 		}
454 		return;
455 
456 	}
457 }
458 
459 static void
460 udbp_bulk_read_clear_stall_callback(struct usb_xfer *xfer, usb_error_t error)
461 {
462 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
463 	struct usb_xfer *xfer_other = sc->sc_xfer[UDBP_T_RD];
464 
465 	if (usbd_clear_stall_callback(xfer, xfer_other)) {
466 		DPRINTF("stall cleared\n");
467 		sc->sc_flags &= ~UDBP_FLAG_READ_STALL;
468 		usbd_transfer_start(xfer_other);
469 	}
470 }
471 
472 static void
473 udbp_bulk_read_complete(node_p node, hook_p hook, void *arg1, int arg2)
474 {
475 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
476 	struct mbuf *m;
477 	int error;
478 
479 	if (sc == NULL) {
480 		return;
481 	}
482 	mtx_lock(&sc->sc_mtx);
483 
484 	m = sc->sc_bulk_in_buffer;
485 
486 	if (m) {
487 
488 		sc->sc_bulk_in_buffer = NULL;
489 
490 		if ((sc->sc_hook == NULL) ||
491 		    NG_HOOK_NOT_VALID(sc->sc_hook)) {
492 			DPRINTF("No upstream hook\n");
493 			goto done;
494 		}
495 		sc->sc_packets_in++;
496 
497 		NG_SEND_DATA_ONLY(error, sc->sc_hook, m);
498 
499 		m = NULL;
500 	}
501 done:
502 	if (m) {
503 		m_freem(m);
504 	}
505 	/* start USB bulk-in transfer, if not already started */
506 
507 	usbd_transfer_start(sc->sc_xfer[UDBP_T_RD]);
508 
509 	mtx_unlock(&sc->sc_mtx);
510 }
511 
512 static void
513 udbp_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
514 {
515 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
516 	struct usb_page_cache *pc;
517 	struct mbuf *m;
518 
519 	switch (USB_GET_STATE(xfer)) {
520 	case USB_ST_TRANSFERRED:
521 
522 		sc->sc_packets_out++;
523 
524 	case USB_ST_SETUP:
525 		if (sc->sc_flags & UDBP_FLAG_WRITE_STALL) {
526 			usbd_transfer_start(sc->sc_xfer[UDBP_T_WR_CS]);
527 			return;
528 		}
529 		/* get next mbuf, if any */
530 
531 		NG_BT_MBUFQ_DEQUEUE(&sc->sc_xmitq_hipri, m);
532 		if (m == NULL) {
533 			NG_BT_MBUFQ_DEQUEUE(&sc->sc_xmitq, m);
534 			if (m == NULL) {
535 				DPRINTF("Data queue is empty\n");
536 				return;
537 			}
538 		}
539 		if (m->m_pkthdr.len > MCLBYTES) {
540 			DPRINTF("truncating large packet "
541 			    "from %d to %d bytes\n", m->m_pkthdr.len,
542 			    MCLBYTES);
543 			m->m_pkthdr.len = MCLBYTES;
544 		}
545 		pc = usbd_xfer_get_frame(xfer, 0);
546 		usbd_m_copy_in(pc, 0, m, 0, m->m_pkthdr.len);
547 
548 		usbd_xfer_set_frame_len(xfer, 0, m->m_pkthdr.len);
549 
550 		DPRINTF("packet out: %d bytes\n", m->m_pkthdr.len);
551 
552 		m_freem(m);
553 
554 		usbd_transfer_submit(xfer);
555 		return;
556 
557 	default:			/* Error */
558 		if (error != USB_ERR_CANCELLED) {
559 			/* try to clear stall first */
560 			sc->sc_flags |= UDBP_FLAG_WRITE_STALL;
561 			usbd_transfer_start(sc->sc_xfer[UDBP_T_WR_CS]);
562 		}
563 		return;
564 
565 	}
566 }
567 
568 static void
569 udbp_bulk_write_clear_stall_callback(struct usb_xfer *xfer, usb_error_t error)
570 {
571 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
572 	struct usb_xfer *xfer_other = sc->sc_xfer[UDBP_T_WR];
573 
574 	if (usbd_clear_stall_callback(xfer, xfer_other)) {
575 		DPRINTF("stall cleared\n");
576 		sc->sc_flags &= ~UDBP_FLAG_WRITE_STALL;
577 		usbd_transfer_start(xfer_other);
578 	}
579 }
580 
581 /***********************************************************************
582  * Start of Netgraph methods
583  **********************************************************************/
584 
585 /*
586  * If this is a device node so this work is done in the attach()
587  * routine and the constructor will return EINVAL as you should not be able
588  * to create nodes that depend on hardware (unless you can add the hardware :)
589  */
590 static int
591 ng_udbp_constructor(node_p node)
592 {
593 	return (EINVAL);
594 }
595 
596 /*
597  * Give our ok for a hook to be added...
598  * If we are not running this might kick a device into life.
599  * Possibly decode information out of the hook name.
600  * Add the hook's private info to the hook structure.
601  * (if we had some). In this example, we assume that there is a
602  * an array of structs, called 'channel' in the private info,
603  * one for each active channel. The private
604  * pointer of each hook points to the appropriate UDBP_hookinfo struct
605  * so that the source of an input packet is easily identified.
606  */
607 static int
608 ng_udbp_newhook(node_p node, hook_p hook, const char *name)
609 {
610 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
611 	int32_t error = 0;
612 
613 	if (strcmp(name, NG_UDBP_HOOK_NAME)) {
614 		return (EINVAL);
615 	}
616 	mtx_lock(&sc->sc_mtx);
617 
618 	if (sc->sc_hook != NULL) {
619 		error = EISCONN;
620 	} else {
621 		sc->sc_hook = hook;
622 		NG_HOOK_SET_PRIVATE(hook, NULL);
623 	}
624 
625 	mtx_unlock(&sc->sc_mtx);
626 
627 	return (error);
628 }
629 
630 /*
631  * Get a netgraph control message.
632  * Check it is one we understand. If needed, send a response.
633  * We could save the address for an async action later, but don't here.
634  * Always free the message.
635  * The response should be in a malloc'd region that the caller can 'free'.
636  * A response is not required.
637  * Theoretically you could respond defferently to old message types if
638  * the cookie in the header didn't match what we consider to be current
639  * (so that old userland programs could continue to work).
640  */
641 static int
642 ng_udbp_rcvmsg(node_p node, item_p item, hook_p lasthook)
643 {
644 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
645 	struct ng_mesg *resp = NULL;
646 	int error = 0;
647 	struct ng_mesg *msg;
648 
649 	NGI_GET_MSG(item, msg);
650 	/* Deal with message according to cookie and command */
651 	switch (msg->header.typecookie) {
652 	case NGM_UDBP_COOKIE:
653 		switch (msg->header.cmd) {
654 		case NGM_UDBP_GET_STATUS:
655 			{
656 				struct ngudbpstat *stats;
657 
658 				NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
659 				if (!resp) {
660 					error = ENOMEM;
661 					break;
662 				}
663 				stats = (struct ngudbpstat *)resp->data;
664 				mtx_lock(&sc->sc_mtx);
665 				stats->packets_in = sc->sc_packets_in;
666 				stats->packets_out = sc->sc_packets_out;
667 				mtx_unlock(&sc->sc_mtx);
668 				break;
669 			}
670 		case NGM_UDBP_SET_FLAG:
671 			if (msg->header.arglen != sizeof(uint32_t)) {
672 				error = EINVAL;
673 				break;
674 			}
675 			DPRINTF("flags = 0x%08x\n",
676 			    *((uint32_t *)msg->data));
677 			break;
678 		default:
679 			error = EINVAL;	/* unknown command */
680 			break;
681 		}
682 		break;
683 	default:
684 		error = EINVAL;		/* unknown cookie type */
685 		break;
686 	}
687 
688 	/* Take care of synchronous response, if any */
689 	NG_RESPOND_MSG(error, node, item, resp);
690 	NG_FREE_MSG(msg);
691 	return (error);
692 }
693 
694 /*
695  * Accept data from the hook and queue it for output.
696  */
697 static int
698 ng_udbp_rcvdata(hook_p hook, item_p item)
699 {
700 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
701 	struct ng_bt_mbufq *queue_ptr;
702 	struct mbuf *m;
703 	struct ng_tag_prio *ptag;
704 	int error;
705 
706 	if (sc == NULL) {
707 		NG_FREE_ITEM(item);
708 		return (EHOSTDOWN);
709 	}
710 	NGI_GET_M(item, m);
711 	NG_FREE_ITEM(item);
712 
713 	/*
714 	 * Now queue the data for when it can be sent
715 	 */
716 	ptag = (void *)m_tag_locate(m, NGM_GENERIC_COOKIE,
717 	    NG_TAG_PRIO, NULL);
718 
719 	if (ptag && (ptag->priority > NG_PRIO_CUTOFF))
720 		queue_ptr = &sc->sc_xmitq_hipri;
721 	else
722 		queue_ptr = &sc->sc_xmitq;
723 
724 	mtx_lock(&sc->sc_mtx);
725 
726 	if (NG_BT_MBUFQ_FULL(queue_ptr)) {
727 		NG_BT_MBUFQ_DROP(queue_ptr);
728 		NG_FREE_M(m);
729 		error = ENOBUFS;
730 	} else {
731 		NG_BT_MBUFQ_ENQUEUE(queue_ptr, m);
732 		/*
733 		 * start bulk-out transfer, if not already started:
734 		 */
735 		usbd_transfer_start(sc->sc_xfer[UDBP_T_WR]);
736 		error = 0;
737 	}
738 
739 	mtx_unlock(&sc->sc_mtx);
740 
741 	return (error);
742 }
743 
744 /*
745  * Do local shutdown processing..
746  * We are a persistant device, we refuse to go away, and
747  * only remove our links and reset ourself.
748  */
749 static int
750 ng_udbp_rmnode(node_p node)
751 {
752 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
753 
754 	/* Let old node go */
755 	NG_NODE_SET_PRIVATE(node, NULL);
756 	NG_NODE_UNREF(node);		/* forget it ever existed */
757 
758 	if (sc == NULL) {
759 		goto done;
760 	}
761 	/* Create Netgraph node */
762 	if (ng_make_node_common(&ng_udbp_typestruct, &sc->sc_node) != 0) {
763 		printf("%s: Could not create Netgraph node\n",
764 		    sc->sc_name);
765 		sc->sc_node = NULL;
766 		goto done;
767 	}
768 	/* Name node */
769 	if (ng_name_node(sc->sc_node, sc->sc_name) != 0) {
770 		printf("%s: Could not name Netgraph node\n",
771 		    sc->sc_name);
772 		NG_NODE_UNREF(sc->sc_node);
773 		sc->sc_node = NULL;
774 		goto done;
775 	}
776 	NG_NODE_SET_PRIVATE(sc->sc_node, sc);
777 
778 done:
779 	if (sc) {
780 		mtx_unlock(&sc->sc_mtx);
781 	}
782 	return (0);
783 }
784 
785 /*
786  * This is called once we've already connected a new hook to the other node.
787  * It gives us a chance to balk at the last minute.
788  */
789 static int
790 ng_udbp_connect(hook_p hook)
791 {
792 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
793 
794 	/* probably not at splnet, force outward queueing */
795 	NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
796 
797 	mtx_lock(&sc->sc_mtx);
798 
799 	sc->sc_flags |= (UDBP_FLAG_READ_STALL |
800 	    UDBP_FLAG_WRITE_STALL);
801 
802 	/* start bulk-in transfer */
803 	usbd_transfer_start(sc->sc_xfer[UDBP_T_RD]);
804 
805 	/* start bulk-out transfer */
806 	usbd_transfer_start(sc->sc_xfer[UDBP_T_WR]);
807 
808 	mtx_unlock(&sc->sc_mtx);
809 
810 	return (0);
811 }
812 
813 /*
814  * Dook disconnection
815  *
816  * For this type, removal of the last link destroys the node
817  */
818 static int
819 ng_udbp_disconnect(hook_p hook)
820 {
821 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
822 	int error = 0;
823 
824 	if (sc != NULL) {
825 
826 		mtx_lock(&sc->sc_mtx);
827 
828 		if (hook != sc->sc_hook) {
829 			error = EINVAL;
830 		} else {
831 
832 			/* stop bulk-in transfer */
833 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_RD_CS]);
834 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_RD]);
835 
836 			/* stop bulk-out transfer */
837 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_WR_CS]);
838 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_WR]);
839 
840 			/* cleanup queues */
841 			NG_BT_MBUFQ_DRAIN(&sc->sc_xmitq);
842 			NG_BT_MBUFQ_DRAIN(&sc->sc_xmitq_hipri);
843 
844 			if (sc->sc_bulk_in_buffer) {
845 				m_freem(sc->sc_bulk_in_buffer);
846 				sc->sc_bulk_in_buffer = NULL;
847 			}
848 			sc->sc_hook = NULL;
849 		}
850 
851 		mtx_unlock(&sc->sc_mtx);
852 	}
853 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
854 	    && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
855 		ng_rmnode_self(NG_HOOK_NODE(hook));
856 
857 	return (error);
858 }
859