xref: /freebsd/sys/dev/usb/misc/udbp.c (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
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 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 int
292 udbp_probe(device_t dev)
293 {
294 	struct usb_attach_arg *uaa = device_get_ivars(dev);
295 
296 	if (uaa->usb_mode != USB_MODE_HOST) {
297 		return (ENXIO);
298 	}
299 	/*
300 	 * XXX Julian, add the id of the device if you have one to test
301 	 * things with. run 'usbdevs -v' and note the 3 ID's that appear.
302 	 * The Vendor Id and Product Id are in hex and the Revision Id is in
303 	 * bcd. But as usual if the revision is 0x101 then you should
304 	 * compare the revision id in the device descriptor with 0x101 Or go
305 	 * search the file usbdevs.h. Maybe the device is already in there.
306 	 */
307 	if (((uaa->info.idVendor == USB_VENDOR_NETCHIP) &&
308 	    (uaa->info.idProduct == USB_PRODUCT_NETCHIP_TURBOCONNECT)))
309 		return (0);
310 
311 	if (((uaa->info.idVendor == USB_VENDOR_PROLIFIC) &&
312 	    ((uaa->info.idProduct == USB_PRODUCT_PROLIFIC_PL2301) ||
313 	    (uaa->info.idProduct == USB_PRODUCT_PROLIFIC_PL2302))))
314 		return (0);
315 
316 	if ((uaa->info.idVendor == USB_VENDOR_ANCHOR) &&
317 	    (uaa->info.idProduct == USB_PRODUCT_ANCHOR_EZLINK))
318 		return (0);
319 
320 	if ((uaa->info.idVendor == USB_VENDOR_GENESYS) &&
321 	    (uaa->info.idProduct == USB_PRODUCT_GENESYS_GL620USB))
322 		return (0);
323 
324 	return (ENXIO);
325 }
326 
327 static int
328 udbp_attach(device_t dev)
329 {
330 	struct usb_attach_arg *uaa = device_get_ivars(dev);
331 	struct udbp_softc *sc = device_get_softc(dev);
332 	int error;
333 
334 	device_set_usb_desc(dev);
335 
336 	snprintf(sc->sc_name, sizeof(sc->sc_name),
337 	    "%s", device_get_nameunit(dev));
338 
339 	mtx_init(&sc->sc_mtx, "udbp lock", NULL, MTX_DEF | MTX_RECURSE);
340 
341 	error = usbd_transfer_setup(uaa->device, &uaa->info.bIfaceIndex,
342 	    sc->sc_xfer, udbp_config, UDBP_T_MAX, sc, &sc->sc_mtx);
343 	if (error) {
344 		DPRINTF("error=%s\n", usbd_errstr(error));
345 		goto detach;
346 	}
347 	NG_BT_MBUFQ_INIT(&sc->sc_xmitq, UDBP_Q_MAXLEN);
348 
349 	NG_BT_MBUFQ_INIT(&sc->sc_xmitq_hipri, UDBP_Q_MAXLEN);
350 
351 	/* create Netgraph node */
352 
353 	if (ng_make_node_common(&ng_udbp_typestruct, &sc->sc_node) != 0) {
354 		printf("%s: Could not create Netgraph node\n",
355 		    sc->sc_name);
356 		sc->sc_node = NULL;
357 		goto detach;
358 	}
359 	/* name node */
360 
361 	if (ng_name_node(sc->sc_node, sc->sc_name) != 0) {
362 		printf("%s: Could not name node\n",
363 		    sc->sc_name);
364 		NG_NODE_UNREF(sc->sc_node);
365 		sc->sc_node = NULL;
366 		goto detach;
367 	}
368 	NG_NODE_SET_PRIVATE(sc->sc_node, sc);
369 
370 	/* the device is now operational */
371 
372 	return (0);			/* success */
373 
374 detach:
375 	udbp_detach(dev);
376 	return (ENOMEM);		/* failure */
377 }
378 
379 static int
380 udbp_detach(device_t dev)
381 {
382 	struct udbp_softc *sc = device_get_softc(dev);
383 
384 	/* destroy Netgraph node */
385 
386 	if (sc->sc_node != NULL) {
387 		NG_NODE_SET_PRIVATE(sc->sc_node, NULL);
388 		ng_rmnode_self(sc->sc_node);
389 		sc->sc_node = NULL;
390 	}
391 	/* free USB transfers, if any */
392 
393 	usbd_transfer_unsetup(sc->sc_xfer, UDBP_T_MAX);
394 
395 	mtx_destroy(&sc->sc_mtx);
396 
397 	/* destroy queues */
398 
399 	NG_BT_MBUFQ_DESTROY(&sc->sc_xmitq);
400 	NG_BT_MBUFQ_DESTROY(&sc->sc_xmitq_hipri);
401 
402 	/* extra check */
403 
404 	if (sc->sc_bulk_in_buffer) {
405 		m_freem(sc->sc_bulk_in_buffer);
406 		sc->sc_bulk_in_buffer = NULL;
407 	}
408 	return (0);			/* success */
409 }
410 
411 static void
412 udbp_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error)
413 {
414 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
415 	struct usb_page_cache *pc;
416 	struct mbuf *m;
417 	int actlen;
418 
419 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
420 
421 	switch (USB_GET_STATE(xfer)) {
422 	case USB_ST_TRANSFERRED:
423 
424 		/* allocate new mbuf */
425 
426 		MGETHDR(m, M_DONTWAIT, MT_DATA);
427 
428 		if (m == NULL) {
429 			goto tr_setup;
430 		}
431 		MCLGET(m, M_DONTWAIT);
432 
433 		if (!(m->m_flags & M_EXT)) {
434 			m_freem(m);
435 			goto tr_setup;
436 		}
437 		m->m_pkthdr.len = m->m_len = actlen;
438 
439 		pc = usbd_xfer_get_frame(xfer, 0);
440 		usbd_copy_out(pc, 0, m->m_data, actlen);
441 
442 		sc->sc_bulk_in_buffer = m;
443 
444 		DPRINTF("received package %d bytes\n", actlen);
445 
446 	case USB_ST_SETUP:
447 tr_setup:
448 		if (sc->sc_bulk_in_buffer) {
449 			ng_send_fn(sc->sc_node, NULL, &udbp_bulk_read_complete, NULL, 0);
450 			return;
451 		}
452 		if (sc->sc_flags & UDBP_FLAG_READ_STALL) {
453 			usbd_transfer_start(sc->sc_xfer[UDBP_T_RD_CS]);
454 			return;
455 		}
456 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
457 		usbd_transfer_submit(xfer);
458 		return;
459 
460 	default:			/* Error */
461 		if (error != USB_ERR_CANCELLED) {
462 			/* try to clear stall first */
463 			sc->sc_flags |= UDBP_FLAG_READ_STALL;
464 			usbd_transfer_start(sc->sc_xfer[UDBP_T_RD_CS]);
465 		}
466 		return;
467 
468 	}
469 }
470 
471 static void
472 udbp_bulk_read_clear_stall_callback(struct usb_xfer *xfer, usb_error_t error)
473 {
474 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
475 	struct usb_xfer *xfer_other = sc->sc_xfer[UDBP_T_RD];
476 
477 	if (usbd_clear_stall_callback(xfer, xfer_other)) {
478 		DPRINTF("stall cleared\n");
479 		sc->sc_flags &= ~UDBP_FLAG_READ_STALL;
480 		usbd_transfer_start(xfer_other);
481 	}
482 }
483 
484 static void
485 udbp_bulk_read_complete(node_p node, hook_p hook, void *arg1, int arg2)
486 {
487 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
488 	struct mbuf *m;
489 	int error;
490 
491 	if (sc == NULL) {
492 		return;
493 	}
494 	mtx_lock(&sc->sc_mtx);
495 
496 	m = sc->sc_bulk_in_buffer;
497 
498 	if (m) {
499 
500 		sc->sc_bulk_in_buffer = NULL;
501 
502 		if ((sc->sc_hook == NULL) ||
503 		    NG_HOOK_NOT_VALID(sc->sc_hook)) {
504 			DPRINTF("No upstream hook\n");
505 			goto done;
506 		}
507 		sc->sc_packets_in++;
508 
509 		NG_SEND_DATA_ONLY(error, sc->sc_hook, m);
510 
511 		m = NULL;
512 	}
513 done:
514 	if (m) {
515 		m_freem(m);
516 	}
517 	/* start USB bulk-in transfer, if not already started */
518 
519 	usbd_transfer_start(sc->sc_xfer[UDBP_T_RD]);
520 
521 	mtx_unlock(&sc->sc_mtx);
522 }
523 
524 static void
525 udbp_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
526 {
527 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
528 	struct usb_page_cache *pc;
529 	struct mbuf *m;
530 
531 	switch (USB_GET_STATE(xfer)) {
532 	case USB_ST_TRANSFERRED:
533 
534 		sc->sc_packets_out++;
535 
536 	case USB_ST_SETUP:
537 		if (sc->sc_flags & UDBP_FLAG_WRITE_STALL) {
538 			usbd_transfer_start(sc->sc_xfer[UDBP_T_WR_CS]);
539 			return;
540 		}
541 		/* get next mbuf, if any */
542 
543 		NG_BT_MBUFQ_DEQUEUE(&sc->sc_xmitq_hipri, m);
544 		if (m == NULL) {
545 			NG_BT_MBUFQ_DEQUEUE(&sc->sc_xmitq, m);
546 			if (m == NULL) {
547 				DPRINTF("Data queue is empty\n");
548 				return;
549 			}
550 		}
551 		if (m->m_pkthdr.len > MCLBYTES) {
552 			DPRINTF("truncating large packet "
553 			    "from %d to %d bytes\n", m->m_pkthdr.len,
554 			    MCLBYTES);
555 			m->m_pkthdr.len = MCLBYTES;
556 		}
557 		pc = usbd_xfer_get_frame(xfer, 0);
558 		usbd_m_copy_in(pc, 0, m, 0, m->m_pkthdr.len);
559 
560 		usbd_xfer_set_frame_len(xfer, 0, m->m_pkthdr.len);
561 
562 		DPRINTF("packet out: %d bytes\n", m->m_pkthdr.len);
563 
564 		m_freem(m);
565 
566 		usbd_transfer_submit(xfer);
567 		return;
568 
569 	default:			/* Error */
570 		if (error != USB_ERR_CANCELLED) {
571 			/* try to clear stall first */
572 			sc->sc_flags |= UDBP_FLAG_WRITE_STALL;
573 			usbd_transfer_start(sc->sc_xfer[UDBP_T_WR_CS]);
574 		}
575 		return;
576 
577 	}
578 }
579 
580 static void
581 udbp_bulk_write_clear_stall_callback(struct usb_xfer *xfer, usb_error_t error)
582 {
583 	struct udbp_softc *sc = usbd_xfer_softc(xfer);
584 	struct usb_xfer *xfer_other = sc->sc_xfer[UDBP_T_WR];
585 
586 	if (usbd_clear_stall_callback(xfer, xfer_other)) {
587 		DPRINTF("stall cleared\n");
588 		sc->sc_flags &= ~UDBP_FLAG_WRITE_STALL;
589 		usbd_transfer_start(xfer_other);
590 	}
591 }
592 
593 /***********************************************************************
594  * Start of Netgraph methods
595  **********************************************************************/
596 
597 /*
598  * If this is a device node so this work is done in the attach()
599  * routine and the constructor will return EINVAL as you should not be able
600  * to create nodes that depend on hardware (unless you can add the hardware :)
601  */
602 static int
603 ng_udbp_constructor(node_p node)
604 {
605 	return (EINVAL);
606 }
607 
608 /*
609  * Give our ok for a hook to be added...
610  * If we are not running this might kick a device into life.
611  * Possibly decode information out of the hook name.
612  * Add the hook's private info to the hook structure.
613  * (if we had some). In this example, we assume that there is a
614  * an array of structs, called 'channel' in the private info,
615  * one for each active channel. The private
616  * pointer of each hook points to the appropriate UDBP_hookinfo struct
617  * so that the source of an input packet is easily identified.
618  */
619 static int
620 ng_udbp_newhook(node_p node, hook_p hook, const char *name)
621 {
622 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
623 	int32_t error = 0;
624 
625 	if (strcmp(name, NG_UDBP_HOOK_NAME)) {
626 		return (EINVAL);
627 	}
628 	mtx_lock(&sc->sc_mtx);
629 
630 	if (sc->sc_hook != NULL) {
631 		error = EISCONN;
632 	} else {
633 		sc->sc_hook = hook;
634 		NG_HOOK_SET_PRIVATE(hook, NULL);
635 	}
636 
637 	mtx_unlock(&sc->sc_mtx);
638 
639 	return (error);
640 }
641 
642 /*
643  * Get a netgraph control message.
644  * Check it is one we understand. If needed, send a response.
645  * We could save the address for an async action later, but don't here.
646  * Always free the message.
647  * The response should be in a malloc'd region that the caller can 'free'.
648  * A response is not required.
649  * Theoretically you could respond defferently to old message types if
650  * the cookie in the header didn't match what we consider to be current
651  * (so that old userland programs could continue to work).
652  */
653 static int
654 ng_udbp_rcvmsg(node_p node, item_p item, hook_p lasthook)
655 {
656 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
657 	struct ng_mesg *resp = NULL;
658 	int error = 0;
659 	struct ng_mesg *msg;
660 
661 	NGI_GET_MSG(item, msg);
662 	/* Deal with message according to cookie and command */
663 	switch (msg->header.typecookie) {
664 	case NGM_UDBP_COOKIE:
665 		switch (msg->header.cmd) {
666 		case NGM_UDBP_GET_STATUS:
667 			{
668 				struct ngudbpstat *stats;
669 
670 				NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
671 				if (!resp) {
672 					error = ENOMEM;
673 					break;
674 				}
675 				stats = (struct ngudbpstat *)resp->data;
676 				mtx_lock(&sc->sc_mtx);
677 				stats->packets_in = sc->sc_packets_in;
678 				stats->packets_out = sc->sc_packets_out;
679 				mtx_unlock(&sc->sc_mtx);
680 				break;
681 			}
682 		case NGM_UDBP_SET_FLAG:
683 			if (msg->header.arglen != sizeof(uint32_t)) {
684 				error = EINVAL;
685 				break;
686 			}
687 			DPRINTF("flags = 0x%08x\n",
688 			    *((uint32_t *)msg->data));
689 			break;
690 		default:
691 			error = EINVAL;	/* unknown command */
692 			break;
693 		}
694 		break;
695 	default:
696 		error = EINVAL;		/* unknown cookie type */
697 		break;
698 	}
699 
700 	/* Take care of synchronous response, if any */
701 	NG_RESPOND_MSG(error, node, item, resp);
702 	NG_FREE_MSG(msg);
703 	return (error);
704 }
705 
706 /*
707  * Accept data from the hook and queue it for output.
708  */
709 static int
710 ng_udbp_rcvdata(hook_p hook, item_p item)
711 {
712 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
713 	struct ng_bt_mbufq *queue_ptr;
714 	struct mbuf *m;
715 	struct ng_tag_prio *ptag;
716 	int error;
717 
718 	if (sc == NULL) {
719 		NG_FREE_ITEM(item);
720 		return (EHOSTDOWN);
721 	}
722 	NGI_GET_M(item, m);
723 	NG_FREE_ITEM(item);
724 
725 	/*
726 	 * Now queue the data for when it can be sent
727 	 */
728 	ptag = (void *)m_tag_locate(m, NGM_GENERIC_COOKIE,
729 	    NG_TAG_PRIO, NULL);
730 
731 	if (ptag && (ptag->priority > NG_PRIO_CUTOFF))
732 		queue_ptr = &sc->sc_xmitq_hipri;
733 	else
734 		queue_ptr = &sc->sc_xmitq;
735 
736 	mtx_lock(&sc->sc_mtx);
737 
738 	if (NG_BT_MBUFQ_FULL(queue_ptr)) {
739 		NG_BT_MBUFQ_DROP(queue_ptr);
740 		NG_FREE_M(m);
741 		error = ENOBUFS;
742 	} else {
743 		NG_BT_MBUFQ_ENQUEUE(queue_ptr, m);
744 		/*
745 		 * start bulk-out transfer, if not already started:
746 		 */
747 		usbd_transfer_start(sc->sc_xfer[UDBP_T_WR]);
748 		error = 0;
749 	}
750 
751 	mtx_unlock(&sc->sc_mtx);
752 
753 	return (error);
754 }
755 
756 /*
757  * Do local shutdown processing..
758  * We are a persistant device, we refuse to go away, and
759  * only remove our links and reset ourself.
760  */
761 static int
762 ng_udbp_rmnode(node_p node)
763 {
764 	struct udbp_softc *sc = NG_NODE_PRIVATE(node);
765 
766 	/* Let old node go */
767 	NG_NODE_SET_PRIVATE(node, NULL);
768 	NG_NODE_UNREF(node);		/* forget it ever existed */
769 
770 	if (sc == NULL) {
771 		goto done;
772 	}
773 	/* Create Netgraph node */
774 	if (ng_make_node_common(&ng_udbp_typestruct, &sc->sc_node) != 0) {
775 		printf("%s: Could not create Netgraph node\n",
776 		    sc->sc_name);
777 		sc->sc_node = NULL;
778 		goto done;
779 	}
780 	/* Name node */
781 	if (ng_name_node(sc->sc_node, sc->sc_name) != 0) {
782 		printf("%s: Could not name Netgraph node\n",
783 		    sc->sc_name);
784 		NG_NODE_UNREF(sc->sc_node);
785 		sc->sc_node = NULL;
786 		goto done;
787 	}
788 	NG_NODE_SET_PRIVATE(sc->sc_node, sc);
789 
790 done:
791 	if (sc) {
792 		mtx_unlock(&sc->sc_mtx);
793 	}
794 	return (0);
795 }
796 
797 /*
798  * This is called once we've already connected a new hook to the other node.
799  * It gives us a chance to balk at the last minute.
800  */
801 static int
802 ng_udbp_connect(hook_p hook)
803 {
804 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
805 
806 	/* probably not at splnet, force outward queueing */
807 	NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
808 
809 	mtx_lock(&sc->sc_mtx);
810 
811 	sc->sc_flags |= (UDBP_FLAG_READ_STALL |
812 	    UDBP_FLAG_WRITE_STALL);
813 
814 	/* start bulk-in transfer */
815 	usbd_transfer_start(sc->sc_xfer[UDBP_T_RD]);
816 
817 	/* start bulk-out transfer */
818 	usbd_transfer_start(sc->sc_xfer[UDBP_T_WR]);
819 
820 	mtx_unlock(&sc->sc_mtx);
821 
822 	return (0);
823 }
824 
825 /*
826  * Dook disconnection
827  *
828  * For this type, removal of the last link destroys the node
829  */
830 static int
831 ng_udbp_disconnect(hook_p hook)
832 {
833 	struct udbp_softc *sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
834 	int error = 0;
835 
836 	if (sc != NULL) {
837 
838 		mtx_lock(&sc->sc_mtx);
839 
840 		if (hook != sc->sc_hook) {
841 			error = EINVAL;
842 		} else {
843 
844 			/* stop bulk-in transfer */
845 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_RD_CS]);
846 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_RD]);
847 
848 			/* stop bulk-out transfer */
849 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_WR_CS]);
850 			usbd_transfer_stop(sc->sc_xfer[UDBP_T_WR]);
851 
852 			/* cleanup queues */
853 			NG_BT_MBUFQ_DRAIN(&sc->sc_xmitq);
854 			NG_BT_MBUFQ_DRAIN(&sc->sc_xmitq_hipri);
855 
856 			if (sc->sc_bulk_in_buffer) {
857 				m_freem(sc->sc_bulk_in_buffer);
858 				sc->sc_bulk_in_buffer = NULL;
859 			}
860 			sc->sc_hook = NULL;
861 		}
862 
863 		mtx_unlock(&sc->sc_mtx);
864 	}
865 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
866 	    && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
867 		ng_rmnode_self(NG_HOOK_NODE(hook));
868 
869 	return (error);
870 }
871