xref: /freebsd/sys/netgraph/ng_ether.c (revision 262e143bd46171a6415a5b28af260a5efa2a3db8)
1 
2 /*
3  * ng_ether.c
4  */
5 
6 /*-
7  * Copyright (c) 1996-2000 Whistle Communications, Inc.
8  * All rights reserved.
9  *
10  * Subject to the following obligations and disclaimer of warranty, use and
11  * redistribution of this software, in source or object code forms, with or
12  * without modifications are expressly permitted by Whistle Communications;
13  * provided, however, that:
14  * 1. Any and all reproductions of the source or object code must include the
15  *    copyright notice above and the following disclaimer of warranties; and
16  * 2. No rights are granted, in any manner or form, to use Whistle
17  *    Communications, Inc. trademarks, including the mark "WHISTLE
18  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
19  *    such appears in the above copyright notice or in the software.
20  *
21  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
22  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
23  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
24  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
26  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
27  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
28  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
29  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
30  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
31  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
32  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
33  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
34  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
36  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
37  * OF SUCH DAMAGE.
38  *
39  * Authors: Archie Cobbs <archie@freebsd.org>
40  *	    Julian Elischer <julian@freebsd.org>
41  *
42  * $FreeBSD$
43  */
44 
45 /*
46  * ng_ether(4) netgraph node type
47  */
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/errno.h>
55 #include <sys/syslog.h>
56 #include <sys/socket.h>
57 
58 #include <net/if.h>
59 #include <net/if_dl.h>
60 #include <net/if_types.h>
61 #include <net/if_arp.h>
62 #include <net/if_var.h>
63 #include <net/ethernet.h>
64 #include <net/if_bridgevar.h>
65 
66 #include <netgraph/ng_message.h>
67 #include <netgraph/netgraph.h>
68 #include <netgraph/ng_parse.h>
69 #include <netgraph/ng_ether.h>
70 
71 #define IFP2NG(ifp)  (IFP2AC((ifp))->ac_netgraph)
72 
73 /* Per-node private data */
74 struct private {
75 	struct ifnet	*ifp;		/* associated interface */
76 	hook_p		upper;		/* upper hook connection */
77 	hook_p		lower;		/* lower hook connection */
78 	hook_p		orphan;		/* orphan hook connection */
79 	u_char		autoSrcAddr;	/* always overwrite source address */
80 	u_char		promisc;	/* promiscuous mode enabled */
81 	u_long		hwassist;	/* hardware checksum capabilities */
82 	u_int		flags;		/* flags e.g. really die */
83 };
84 typedef struct private *priv_p;
85 
86 /* Hook pointers used by if_ethersubr.c to callback to netgraph */
87 extern	void	(*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
88 extern	void	(*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
89 extern	int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
90 extern	void	(*ng_ether_attach_p)(struct ifnet *ifp);
91 extern	void	(*ng_ether_detach_p)(struct ifnet *ifp);
92 extern	void	(*ng_ether_link_state_p)(struct ifnet *ifp, int state);
93 
94 /* Functional hooks called from if_ethersubr.c */
95 static void	ng_ether_input(struct ifnet *ifp, struct mbuf **mp);
96 static void	ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m);
97 static int	ng_ether_output(struct ifnet *ifp, struct mbuf **mp);
98 static void	ng_ether_attach(struct ifnet *ifp);
99 static void	ng_ether_detach(struct ifnet *ifp);
100 static void	ng_ether_link_state(struct ifnet *ifp, int state);
101 
102 /* Other functions */
103 static int	ng_ether_rcv_lower(node_p node, struct mbuf *m);
104 static int	ng_ether_rcv_upper(node_p node, struct mbuf *m);
105 
106 /* Netgraph node methods */
107 static ng_constructor_t	ng_ether_constructor;
108 static ng_rcvmsg_t	ng_ether_rcvmsg;
109 static ng_shutdown_t	ng_ether_shutdown;
110 static ng_newhook_t	ng_ether_newhook;
111 static ng_connect_t	ng_ether_connect;
112 static ng_rcvdata_t	ng_ether_rcvdata;
113 static ng_disconnect_t	ng_ether_disconnect;
114 static int		ng_ether_mod_event(module_t mod, int event, void *data);
115 
116 /* List of commands and how to convert arguments to/from ASCII */
117 static const struct ng_cmdlist ng_ether_cmdlist[] = {
118 	{
119 	  NGM_ETHER_COOKIE,
120 	  NGM_ETHER_GET_IFNAME,
121 	  "getifname",
122 	  NULL,
123 	  &ng_parse_string_type
124 	},
125 	{
126 	  NGM_ETHER_COOKIE,
127 	  NGM_ETHER_GET_IFINDEX,
128 	  "getifindex",
129 	  NULL,
130 	  &ng_parse_int32_type
131 	},
132 	{
133 	  NGM_ETHER_COOKIE,
134 	  NGM_ETHER_GET_ENADDR,
135 	  "getenaddr",
136 	  NULL,
137 	  &ng_parse_enaddr_type
138 	},
139 	{
140 	  NGM_ETHER_COOKIE,
141 	  NGM_ETHER_SET_ENADDR,
142 	  "setenaddr",
143 	  &ng_parse_enaddr_type,
144 	  NULL
145 	},
146 	{
147 	  NGM_ETHER_COOKIE,
148 	  NGM_ETHER_GET_PROMISC,
149 	  "getpromisc",
150 	  NULL,
151 	  &ng_parse_int32_type
152 	},
153 	{
154 	  NGM_ETHER_COOKIE,
155 	  NGM_ETHER_SET_PROMISC,
156 	  "setpromisc",
157 	  &ng_parse_int32_type,
158 	  NULL
159 	},
160 	{
161 	  NGM_ETHER_COOKIE,
162 	  NGM_ETHER_GET_AUTOSRC,
163 	  "getautosrc",
164 	  NULL,
165 	  &ng_parse_int32_type
166 	},
167 	{
168 	  NGM_ETHER_COOKIE,
169 	  NGM_ETHER_SET_AUTOSRC,
170 	  "setautosrc",
171 	  &ng_parse_int32_type,
172 	  NULL
173 	},
174 	{
175 	  NGM_ETHER_COOKIE,
176 	  NGM_ETHER_ADD_MULTI,
177 	  "addmulti",
178 	  &ng_parse_enaddr_type,
179 	  NULL
180 	},
181 	{
182 	  NGM_ETHER_COOKIE,
183 	  NGM_ETHER_DEL_MULTI,
184 	  "delmulti",
185 	  &ng_parse_enaddr_type,
186 	  NULL
187 	},
188 	{
189 	  NGM_ETHER_COOKIE,
190 	  NGM_ETHER_DETACH,
191 	  "detach",
192 	  NULL,
193 	  NULL
194 	},
195 	{ 0 }
196 };
197 
198 static struct ng_type ng_ether_typestruct = {
199 	.version =	NG_ABI_VERSION,
200 	.name =		NG_ETHER_NODE_TYPE,
201 	.mod_event =	ng_ether_mod_event,
202 	.constructor =	ng_ether_constructor,
203 	.rcvmsg =	ng_ether_rcvmsg,
204 	.shutdown =	ng_ether_shutdown,
205 	.newhook =	ng_ether_newhook,
206 	.connect =	ng_ether_connect,
207 	.rcvdata =	ng_ether_rcvdata,
208 	.disconnect =	ng_ether_disconnect,
209 	.cmdlist =	ng_ether_cmdlist,
210 };
211 NETGRAPH_INIT(ether, &ng_ether_typestruct);
212 
213 /******************************************************************
214 		    ETHERNET FUNCTION HOOKS
215 ******************************************************************/
216 
217 /*
218  * Handle a packet that has come in on an interface. We get to
219  * look at it here before any upper layer protocols do.
220  *
221  * NOTE: this function will get called at splimp()
222  */
223 static void
224 ng_ether_input(struct ifnet *ifp, struct mbuf **mp)
225 {
226 	const node_p node = IFP2NG(ifp);
227 	const priv_p priv = NG_NODE_PRIVATE(node);
228 	int error;
229 
230 	/* If "lower" hook not connected, let packet continue */
231 	if (priv->lower == NULL)
232 		return;
233 	NG_SEND_DATA_ONLY(error, priv->lower, *mp);	/* sets *mp = NULL */
234 }
235 
236 /*
237  * Handle a packet that has come in on an interface, and which
238  * does not match any of our known protocols (an ``orphan'').
239  *
240  * NOTE: this function will get called at splimp()
241  */
242 static void
243 ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m)
244 {
245 	const node_p node = IFP2NG(ifp);
246 	const priv_p priv = NG_NODE_PRIVATE(node);
247 	int error;
248 
249 	/* If "orphan" hook not connected, discard packet */
250 	if (priv->orphan == NULL) {
251 		m_freem(m);
252 		return;
253 	}
254 	NG_SEND_DATA_ONLY(error, priv->orphan, m);
255 }
256 
257 /*
258  * Handle a packet that is going out on an interface.
259  * The Ethernet header is already attached to the mbuf.
260  */
261 static int
262 ng_ether_output(struct ifnet *ifp, struct mbuf **mp)
263 {
264 	const node_p node = IFP2NG(ifp);
265 	const priv_p priv = NG_NODE_PRIVATE(node);
266 	int error = 0;
267 
268 	/* If "upper" hook not connected, let packet continue */
269 	if (priv->upper == NULL)
270 		return (0);
271 
272 	/* Send it out "upper" hook */
273 	NG_SEND_DATA_ONLY(error, priv->upper, *mp);
274 	return (error);
275 }
276 
277 /*
278  * A new Ethernet interface has been attached.
279  * Create a new node for it, etc.
280  */
281 static void
282 ng_ether_attach(struct ifnet *ifp)
283 {
284 	priv_p priv;
285 	node_p node;
286 
287 	/* Create node */
288 	KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
289 	if (ng_make_node_common(&ng_ether_typestruct, &node) != 0) {
290 		log(LOG_ERR, "%s: can't %s for %s\n",
291 		    __func__, "create node", ifp->if_xname);
292 		return;
293 	}
294 
295 	/* Allocate private data */
296 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
297 	if (priv == NULL) {
298 		log(LOG_ERR, "%s: can't %s for %s\n",
299 		    __func__, "allocate memory", ifp->if_xname);
300 		NG_NODE_UNREF(node);
301 		return;
302 	}
303 	NG_NODE_SET_PRIVATE(node, priv);
304 	priv->ifp = ifp;
305 	IFP2NG(ifp) = node;
306 	priv->autoSrcAddr = 1;
307 	priv->hwassist = ifp->if_hwassist;
308 
309 	/* Try to give the node the same name as the interface */
310 	if (ng_name_node(node, ifp->if_xname) != 0) {
311 		log(LOG_WARNING, "%s: can't name node %s\n",
312 		    __func__, ifp->if_xname);
313 	}
314 }
315 
316 /*
317  * An Ethernet interface is being detached.
318  * REALLY Destroy its node.
319  */
320 static void
321 ng_ether_detach(struct ifnet *ifp)
322 {
323 	const node_p node = IFP2NG(ifp);
324 	const priv_p priv = NG_NODE_PRIVATE(node);
325 
326 	NG_NODE_REALLY_DIE(node);	/* Force real removal of node */
327 	/*
328 	 * We can't assume the ifnet is still around when we run shutdown
329 	 * So zap it now. XXX We HOPE that anything running at this time
330 	 * handles it (as it should in the non netgraph case).
331 	 */
332 	IFP2NG(ifp) = NULL;
333 	priv->ifp = NULL;	/* XXX race if interrupted an output packet */
334 	ng_rmnode_self(node);		/* remove all netgraph parts */
335 }
336 
337 /*
338  * Notify graph about link event.
339  * if_link_state_change() has already checked that the state has changed.
340  */
341 static void
342 ng_ether_link_state(struct ifnet *ifp, int state)
343 {
344 	const node_p node = IFP2NG(ifp);
345 	const priv_p priv = NG_NODE_PRIVATE(node);
346 	struct ng_mesg *msg;
347 	int cmd, dummy_error = 0;
348 
349 	if (priv->lower == NULL)
350                 return;
351 
352 	if (state == LINK_STATE_UP)
353 		cmd = NGM_LINK_IS_UP;
354 	else if (state == LINK_STATE_DOWN)
355 		cmd = NGM_LINK_IS_DOWN;
356 	else
357 		return;
358 
359 	NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
360 	if (msg != NULL)
361 		NG_SEND_MSG_HOOK(dummy_error, node, msg, priv->lower, 0);
362 }
363 
364 /******************************************************************
365 		    NETGRAPH NODE METHODS
366 ******************************************************************/
367 
368 /*
369  * It is not possible or allowable to create a node of this type.
370  * Nodes get created when the interface is attached (or, when
371  * this node type's KLD is loaded).
372  */
373 static int
374 ng_ether_constructor(node_p node)
375 {
376 	return (EINVAL);
377 }
378 
379 /*
380  * Check for attaching a new hook.
381  */
382 static	int
383 ng_ether_newhook(node_p node, hook_p hook, const char *name)
384 {
385 	const priv_p priv = NG_NODE_PRIVATE(node);
386 	hook_p *hookptr;
387 
388 	/* Divert hook is an alias for lower */
389 	if (strcmp(name, NG_ETHER_HOOK_DIVERT) == 0)
390 		name = NG_ETHER_HOOK_LOWER;
391 
392 	/* Which hook? */
393 	if (strcmp(name, NG_ETHER_HOOK_UPPER) == 0)
394 		hookptr = &priv->upper;
395 	else if (strcmp(name, NG_ETHER_HOOK_LOWER) == 0)
396 		hookptr = &priv->lower;
397 	else if (strcmp(name, NG_ETHER_HOOK_ORPHAN) == 0)
398 		hookptr = &priv->orphan;
399 	else
400 		return (EINVAL);
401 
402 	/* Check if already connected (shouldn't be, but doesn't hurt) */
403 	if (*hookptr != NULL)
404 		return (EISCONN);
405 
406 	/* Disable hardware checksums while 'upper' hook is connected */
407 	if (hookptr == &priv->upper)
408 		priv->ifp->if_hwassist = 0;
409 
410 	/* OK */
411 	*hookptr = hook;
412 	return (0);
413 }
414 
415 /*
416  * Hooks are attached, adjust to force queueing.
417  * We don't really care which hook it is.
418  * they should all be queuing for outgoing data.
419  */
420 static	int
421 ng_ether_connect(hook_p hook)
422 {
423 	NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
424 	return (0);
425 }
426 
427 /*
428  * Receive an incoming control message.
429  */
430 static int
431 ng_ether_rcvmsg(node_p node, item_p item, hook_p lasthook)
432 {
433 	const priv_p priv = NG_NODE_PRIVATE(node);
434 	struct ng_mesg *resp = NULL;
435 	int error = 0;
436 	struct ng_mesg *msg;
437 
438 	NGI_GET_MSG(item, msg);
439 	switch (msg->header.typecookie) {
440 	case NGM_ETHER_COOKIE:
441 		switch (msg->header.cmd) {
442 		case NGM_ETHER_GET_IFNAME:
443 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
444 			if (resp == NULL) {
445 				error = ENOMEM;
446 				break;
447 			}
448 			strlcpy(resp->data, priv->ifp->if_xname, IFNAMSIZ);
449 			break;
450 		case NGM_ETHER_GET_IFINDEX:
451 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
452 			if (resp == NULL) {
453 				error = ENOMEM;
454 				break;
455 			}
456 			*((u_int32_t *)resp->data) = priv->ifp->if_index;
457 			break;
458 		case NGM_ETHER_GET_ENADDR:
459 			NG_MKRESPONSE(resp, msg, ETHER_ADDR_LEN, M_NOWAIT);
460 			if (resp == NULL) {
461 				error = ENOMEM;
462 				break;
463 			}
464 			bcopy(IF_LLADDR(priv->ifp),
465 			    resp->data, ETHER_ADDR_LEN);
466 			break;
467 		case NGM_ETHER_SET_ENADDR:
468 		    {
469 			if (msg->header.arglen != ETHER_ADDR_LEN) {
470 				error = EINVAL;
471 				break;
472 			}
473 			error = if_setlladdr(priv->ifp,
474 			    (u_char *)msg->data, ETHER_ADDR_LEN);
475 			break;
476 		    }
477 		case NGM_ETHER_GET_PROMISC:
478 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
479 			if (resp == NULL) {
480 				error = ENOMEM;
481 				break;
482 			}
483 			*((u_int32_t *)resp->data) = priv->promisc;
484 			break;
485 		case NGM_ETHER_SET_PROMISC:
486 		    {
487 			u_char want;
488 
489 			if (msg->header.arglen != sizeof(u_int32_t)) {
490 				error = EINVAL;
491 				break;
492 			}
493 			want = !!*((u_int32_t *)msg->data);
494 			if (want ^ priv->promisc) {
495 				if ((error = ifpromisc(priv->ifp, want)) != 0)
496 					break;
497 				priv->promisc = want;
498 			}
499 			break;
500 		    }
501 		case NGM_ETHER_GET_AUTOSRC:
502 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
503 			if (resp == NULL) {
504 				error = ENOMEM;
505 				break;
506 			}
507 			*((u_int32_t *)resp->data) = priv->autoSrcAddr;
508 			break;
509 		case NGM_ETHER_SET_AUTOSRC:
510 			if (msg->header.arglen != sizeof(u_int32_t)) {
511 				error = EINVAL;
512 				break;
513 			}
514 			priv->autoSrcAddr = !!*((u_int32_t *)msg->data);
515 			break;
516 		case NGM_ETHER_ADD_MULTI:
517 		    {
518 			struct sockaddr_dl sa_dl;
519 			struct ifmultiaddr *ifm;
520 
521 			if (msg->header.arglen != ETHER_ADDR_LEN) {
522 				error = EINVAL;
523 				break;
524 			}
525 			bzero(&sa_dl, sizeof(struct sockaddr_dl));
526 			sa_dl.sdl_len = sizeof(struct sockaddr_dl);
527 			sa_dl.sdl_family = AF_LINK;
528 			sa_dl.sdl_alen = ETHER_ADDR_LEN;
529 			bcopy((void *)msg->data, LLADDR(&sa_dl),
530 			    ETHER_ADDR_LEN);
531 			error = if_addmulti(priv->ifp,
532 			    (struct sockaddr *)&sa_dl, &ifm);
533 			break;
534 		    }
535 		case NGM_ETHER_DEL_MULTI:
536 		    {
537 			struct sockaddr_dl sa_dl;
538 
539 			if (msg->header.arglen != ETHER_ADDR_LEN) {
540 				error = EINVAL;
541 				break;
542 			}
543 			bzero(&sa_dl, sizeof(struct sockaddr_dl));
544 			sa_dl.sdl_len = sizeof(struct sockaddr_dl);
545 			sa_dl.sdl_family = AF_LINK;
546 			sa_dl.sdl_alen = ETHER_ADDR_LEN;
547 			bcopy((void *)msg->data, LLADDR(&sa_dl),
548 			    ETHER_ADDR_LEN);
549 			error = if_delmulti(priv->ifp,
550 			    (struct sockaddr *)&sa_dl);
551 			break;
552 		    }
553 		case NGM_ETHER_DETACH:
554 			ng_ether_detach(priv->ifp);
555 			break;
556 		default:
557 			error = EINVAL;
558 			break;
559 		}
560 		break;
561 	default:
562 		error = EINVAL;
563 		break;
564 	}
565 	NG_RESPOND_MSG(error, node, item, resp);
566 	NG_FREE_MSG(msg);
567 	return (error);
568 }
569 
570 /*
571  * Receive data on a hook.
572  */
573 static int
574 ng_ether_rcvdata(hook_p hook, item_p item)
575 {
576 	const node_p node = NG_HOOK_NODE(hook);
577 	const priv_p priv = NG_NODE_PRIVATE(node);
578 	struct mbuf *m;
579 
580 	NGI_GET_M(item, m);
581 	NG_FREE_ITEM(item);
582 
583 	if (hook == priv->lower || hook == priv->orphan)
584 		return ng_ether_rcv_lower(node, m);
585 	if (hook == priv->upper)
586 		return ng_ether_rcv_upper(node, m);
587 	panic("%s: weird hook", __func__);
588 #ifdef RESTARTABLE_PANICS /* so we don't get an error msg in LINT */
589 	return (0);
590 #endif
591 }
592 
593 /*
594  * Handle an mbuf received on the "lower" or "orphan" hook.
595  */
596 static int
597 ng_ether_rcv_lower(node_p node, struct mbuf *m)
598 {
599 	const priv_p priv = NG_NODE_PRIVATE(node);
600  	struct ifnet *const ifp = priv->ifp;
601 
602 	/* Check whether interface is ready for packets */
603 	if (!((ifp->if_flags & IFF_UP) &&
604 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
605 		NG_FREE_M(m);
606 		return (ENETDOWN);
607 	}
608 
609 	/* Make sure header is fully pulled up */
610 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
611 		NG_FREE_M(m);
612 		return (EINVAL);
613 	}
614 	if (m->m_len < sizeof(struct ether_header)
615 	    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
616 		return (ENOBUFS);
617 
618 	/* Drop in the MAC address if desired */
619 	if (priv->autoSrcAddr) {
620 
621 		/* Make the mbuf writable if it's not already */
622 		if (!M_WRITABLE(m)
623 		    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
624 			return (ENOBUFS);
625 
626 		/* Overwrite source MAC address */
627 		bcopy(IF_LLADDR(ifp),
628 		    mtod(m, struct ether_header *)->ether_shost,
629 		    ETHER_ADDR_LEN);
630 	}
631 
632 	/* Send it on its way */
633 	return ether_output_frame(ifp, m);
634 }
635 
636 /*
637  * Handle an mbuf received on the "upper" hook.
638  */
639 static int
640 ng_ether_rcv_upper(node_p node, struct mbuf *m)
641 {
642 	const priv_p priv = NG_NODE_PRIVATE(node);
643 	struct ifnet *ifp = priv->ifp;
644 
645 	/* Check length and pull off header */
646 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
647 		NG_FREE_M(m);
648 		return (EINVAL);
649 	}
650 	if (m->m_len < sizeof(struct ether_header) &&
651 	    (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
652 		return (ENOBUFS);
653 
654 	m->m_pkthdr.rcvif = ifp;
655 
656 	/* Pass the packet to the bridge, it may come back to us */
657 	if (ifp->if_bridge) {
658 		BRIDGE_INPUT(ifp, m);
659 		if (m == NULL)
660 			return (0);
661 	}
662 
663 	/* Route packet back in */
664 	ether_demux(ifp, m);
665 	return (0);
666 }
667 
668 /*
669  * Shutdown node. This resets the node but does not remove it
670  * unless the REALLY_DIE flag is set.
671  */
672 static int
673 ng_ether_shutdown(node_p node)
674 {
675 	const priv_p priv = NG_NODE_PRIVATE(node);
676 
677 	if (node->nd_flags & NGF_REALLY_DIE) {
678 		/*
679 		 * WE came here because the ethernet card is being unloaded,
680 		 * so stop being persistant.
681 		 * Actually undo all the things we did on creation.
682 		 * Assume the ifp has already been freed.
683 		 */
684 		NG_NODE_SET_PRIVATE(node, NULL);
685 		FREE(priv, M_NETGRAPH);
686 		NG_NODE_UNREF(node);	/* free node itself */
687 		return (0);
688 	}
689 	if (priv->promisc) {		/* disable promiscuous mode */
690 		(void)ifpromisc(priv->ifp, 0);
691 		priv->promisc = 0;
692 	}
693 	priv->autoSrcAddr = 1;		/* reset auto-src-addr flag */
694 	NG_NODE_REVIVE(node);		/* Signal ng_rmnode we are persisant */
695 
696 	return (0);
697 }
698 
699 /*
700  * Hook disconnection.
701  */
702 static int
703 ng_ether_disconnect(hook_p hook)
704 {
705 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
706 
707 	if (hook == priv->upper) {
708 		priv->upper = NULL;
709 		if (priv->ifp != NULL)		/* restore h/w csum */
710 			priv->ifp->if_hwassist = priv->hwassist;
711 	} else if (hook == priv->lower)
712 		priv->lower = NULL;
713 	else if (hook == priv->orphan)
714 		priv->orphan = NULL;
715 	else
716 		panic("%s: weird hook", __func__);
717 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
718 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
719 		ng_rmnode_self(NG_HOOK_NODE(hook));	/* reset node */
720 	return (0);
721 }
722 
723 /******************************************************************
724 		    	INITIALIZATION
725 ******************************************************************/
726 
727 /*
728  * Handle loading and unloading for this node type.
729  */
730 static int
731 ng_ether_mod_event(module_t mod, int event, void *data)
732 {
733 	struct ifnet *ifp;
734 	int error = 0;
735 	int s;
736 
737 	s = splnet();
738 	switch (event) {
739 	case MOD_LOAD:
740 
741 		/* Register function hooks */
742 		if (ng_ether_attach_p != NULL) {
743 			error = EEXIST;
744 			break;
745 		}
746 		ng_ether_attach_p = ng_ether_attach;
747 		ng_ether_detach_p = ng_ether_detach;
748 		ng_ether_output_p = ng_ether_output;
749 		ng_ether_input_p = ng_ether_input;
750 		ng_ether_input_orphan_p = ng_ether_input_orphan;
751 		ng_ether_link_state_p = ng_ether_link_state;
752 
753 		/* Create nodes for any already-existing Ethernet interfaces */
754 		IFNET_RLOCK();
755 		TAILQ_FOREACH(ifp, &ifnet, if_link) {
756 			if (ifp->if_type == IFT_ETHER
757 			    || ifp->if_type == IFT_L2VLAN)
758 				ng_ether_attach(ifp);
759 		}
760 		IFNET_RUNLOCK();
761 		break;
762 
763 	case MOD_UNLOAD:
764 
765 		/*
766 		 * Note that the base code won't try to unload us until
767 		 * all nodes have been removed, and that can't happen
768 		 * until all Ethernet interfaces are removed. In any
769 		 * case, we know there are no nodes left if the action
770 		 * is MOD_UNLOAD, so there's no need to detach any nodes.
771 		 */
772 
773 		/* Unregister function hooks */
774 		ng_ether_attach_p = NULL;
775 		ng_ether_detach_p = NULL;
776 		ng_ether_output_p = NULL;
777 		ng_ether_input_p = NULL;
778 		ng_ether_input_orphan_p = NULL;
779 		ng_ether_link_state_p = NULL;
780 		break;
781 
782 	default:
783 		error = EOPNOTSUPP;
784 		break;
785 	}
786 	splx(s);
787 	return (error);
788 }
789 
790