xref: /freebsd/sys/netgraph/ng_ether.c (revision 6c6c03be2ddb04c54e455122799923deaefa4114)
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 #include <sys/vimage.h>
58 
59 #include <net/if.h>
60 #include <net/if_dl.h>
61 #include <net/if_types.h>
62 #include <net/if_arp.h>
63 #include <net/if_var.h>
64 #include <net/ethernet.h>
65 #include <net/if_bridgevar.h>
66 
67 #include <netgraph/ng_message.h>
68 #include <netgraph/netgraph.h>
69 #include <netgraph/ng_parse.h>
70 #include <netgraph/ng_ether.h>
71 
72 #define IFP2NG(ifp)  (IFP2AC((ifp))->ac_netgraph)
73 
74 /* Per-node private data */
75 struct private {
76 	struct ifnet	*ifp;		/* associated interface */
77 	hook_p		upper;		/* upper hook connection */
78 	hook_p		lower;		/* lower hook connection */
79 	hook_p		orphan;		/* orphan hook connection */
80 	u_char		autoSrcAddr;	/* always overwrite source address */
81 	u_char		promisc;	/* promiscuous mode enabled */
82 	u_long		hwassist;	/* hardware checksum capabilities */
83 	u_int		flags;		/* flags e.g. really die */
84 };
85 typedef struct private *priv_p;
86 
87 /* Hook pointers used by if_ethersubr.c to callback to netgraph */
88 extern	void	(*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
89 extern	void	(*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
90 extern	int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
91 extern	void	(*ng_ether_attach_p)(struct ifnet *ifp);
92 extern	void	(*ng_ether_detach_p)(struct ifnet *ifp);
93 extern	void	(*ng_ether_link_state_p)(struct ifnet *ifp, int state);
94 
95 /* Functional hooks called from if_ethersubr.c */
96 static void	ng_ether_input(struct ifnet *ifp, struct mbuf **mp);
97 static void	ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m);
98 static int	ng_ether_output(struct ifnet *ifp, struct mbuf **mp);
99 static void	ng_ether_attach(struct ifnet *ifp);
100 static void	ng_ether_detach(struct ifnet *ifp);
101 static void	ng_ether_link_state(struct ifnet *ifp, int state);
102 
103 /* Other functions */
104 static int	ng_ether_rcv_lower(node_p node, struct mbuf *m);
105 static int	ng_ether_rcv_upper(node_p node, struct mbuf *m);
106 
107 /* Netgraph node methods */
108 static ng_constructor_t	ng_ether_constructor;
109 static ng_rcvmsg_t	ng_ether_rcvmsg;
110 static ng_shutdown_t	ng_ether_shutdown;
111 static ng_newhook_t	ng_ether_newhook;
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 	.rcvdata =	ng_ether_rcvdata,
207 	.disconnect =	ng_ether_disconnect,
208 	.cmdlist =	ng_ether_cmdlist,
209 };
210 NETGRAPH_INIT(ether, &ng_ether_typestruct);
211 
212 /******************************************************************
213 		    ETHERNET FUNCTION HOOKS
214 ******************************************************************/
215 
216 /*
217  * Handle a packet that has come in on an interface. We get to
218  * look at it here before any upper layer protocols do.
219  *
220  * NOTE: this function will get called at splimp()
221  */
222 static void
223 ng_ether_input(struct ifnet *ifp, struct mbuf **mp)
224 {
225 	const node_p node = IFP2NG(ifp);
226 	const priv_p priv = NG_NODE_PRIVATE(node);
227 	int error;
228 
229 	/* If "lower" hook not connected, let packet continue */
230 	if (priv->lower == NULL)
231 		return;
232 	NG_SEND_DATA_ONLY(error, priv->lower, *mp);	/* sets *mp = NULL */
233 }
234 
235 /*
236  * Handle a packet that has come in on an interface, and which
237  * does not match any of our known protocols (an ``orphan'').
238  *
239  * NOTE: this function will get called at splimp()
240  */
241 static void
242 ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m)
243 {
244 	const node_p node = IFP2NG(ifp);
245 	const priv_p priv = NG_NODE_PRIVATE(node);
246 	int error;
247 
248 	/* If "orphan" hook not connected, discard packet */
249 	if (priv->orphan == NULL) {
250 		m_freem(m);
251 		return;
252 	}
253 	NG_SEND_DATA_ONLY(error, priv->orphan, m);
254 }
255 
256 /*
257  * Handle a packet that is going out on an interface.
258  * The Ethernet header is already attached to the mbuf.
259  */
260 static int
261 ng_ether_output(struct ifnet *ifp, struct mbuf **mp)
262 {
263 	const node_p node = IFP2NG(ifp);
264 	const priv_p priv = NG_NODE_PRIVATE(node);
265 	int error = 0;
266 
267 	/* If "upper" hook not connected, let packet continue */
268 	if (priv->upper == NULL)
269 		return (0);
270 
271 	/* Send it out "upper" hook */
272 	NG_SEND_DATA_ONLY(error, priv->upper, *mp);
273 	return (error);
274 }
275 
276 /*
277  * A new Ethernet interface has been attached.
278  * Create a new node for it, etc.
279  */
280 static void
281 ng_ether_attach(struct ifnet *ifp)
282 {
283 	priv_p priv;
284 	node_p node;
285 
286 	/* Create node */
287 	KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
288 	if (ng_make_node_common(&ng_ether_typestruct, &node) != 0) {
289 		log(LOG_ERR, "%s: can't %s for %s\n",
290 		    __func__, "create node", ifp->if_xname);
291 		return;
292 	}
293 
294 	/* Allocate private data */
295 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
296 	if (priv == NULL) {
297 		log(LOG_ERR, "%s: can't %s for %s\n",
298 		    __func__, "allocate memory", ifp->if_xname);
299 		NG_NODE_UNREF(node);
300 		return;
301 	}
302 	NG_NODE_SET_PRIVATE(node, priv);
303 	priv->ifp = ifp;
304 	IFP2NG(ifp) = node;
305 	priv->hwassist = ifp->if_hwassist;
306 
307 	/* Try to give the node the same name as the interface */
308 	if (ng_name_node(node, ifp->if_xname) != 0) {
309 		log(LOG_WARNING, "%s: can't name node %s\n",
310 		    __func__, ifp->if_xname);
311 	}
312 }
313 
314 /*
315  * An Ethernet interface is being detached.
316  * REALLY Destroy its node.
317  */
318 static void
319 ng_ether_detach(struct ifnet *ifp)
320 {
321 	const node_p node = IFP2NG(ifp);
322 	const priv_p priv = NG_NODE_PRIVATE(node);
323 
324 	NG_NODE_REALLY_DIE(node);	/* Force real removal of node */
325 	/*
326 	 * We can't assume the ifnet is still around when we run shutdown
327 	 * So zap it now. XXX We HOPE that anything running at this time
328 	 * handles it (as it should in the non netgraph case).
329 	 */
330 	IFP2NG(ifp) = NULL;
331 	priv->ifp = NULL;	/* XXX race if interrupted an output packet */
332 	ng_rmnode_self(node);		/* remove all netgraph parts */
333 }
334 
335 /*
336  * Notify graph about link event.
337  * if_link_state_change() has already checked that the state has changed.
338  */
339 static void
340 ng_ether_link_state(struct ifnet *ifp, int state)
341 {
342 	const node_p node = IFP2NG(ifp);
343 	const priv_p priv = NG_NODE_PRIVATE(node);
344 	struct ng_mesg *msg;
345 	int cmd, dummy_error = 0;
346 
347 	if (priv->lower == NULL)
348                 return;
349 
350 	if (state == LINK_STATE_UP)
351 		cmd = NGM_LINK_IS_UP;
352 	else if (state == LINK_STATE_DOWN)
353 		cmd = NGM_LINK_IS_DOWN;
354 	else
355 		return;
356 
357 	NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
358 	if (msg != NULL)
359 		NG_SEND_MSG_HOOK(dummy_error, node, msg, priv->lower, 0);
360 }
361 
362 /******************************************************************
363 		    NETGRAPH NODE METHODS
364 ******************************************************************/
365 
366 /*
367  * It is not possible or allowable to create a node of this type.
368  * Nodes get created when the interface is attached (or, when
369  * this node type's KLD is loaded).
370  */
371 static int
372 ng_ether_constructor(node_p node)
373 {
374 	return (EINVAL);
375 }
376 
377 /*
378  * Check for attaching a new hook.
379  */
380 static	int
381 ng_ether_newhook(node_p node, hook_p hook, const char *name)
382 {
383 	const priv_p priv = NG_NODE_PRIVATE(node);
384 	hook_p *hookptr;
385 
386 	/* Divert hook is an alias for lower */
387 	if (strcmp(name, NG_ETHER_HOOK_DIVERT) == 0)
388 		name = NG_ETHER_HOOK_LOWER;
389 
390 	/* Which hook? */
391 	if (strcmp(name, NG_ETHER_HOOK_UPPER) == 0)
392 		hookptr = &priv->upper;
393 	else if (strcmp(name, NG_ETHER_HOOK_LOWER) == 0)
394 		hookptr = &priv->lower;
395 	else if (strcmp(name, NG_ETHER_HOOK_ORPHAN) == 0)
396 		hookptr = &priv->orphan;
397 	else
398 		return (EINVAL);
399 
400 	/* Check if already connected (shouldn't be, but doesn't hurt) */
401 	if (*hookptr != NULL)
402 		return (EISCONN);
403 
404 	/* Disable hardware checksums while 'upper' hook is connected */
405 	if (hookptr == &priv->upper)
406 		priv->ifp->if_hwassist = 0;
407 
408 	/* OK */
409 	*hookptr = hook;
410 	return (0);
411 }
412 
413 /*
414  * Receive an incoming control message.
415  */
416 static int
417 ng_ether_rcvmsg(node_p node, item_p item, hook_p lasthook)
418 {
419 	const priv_p priv = NG_NODE_PRIVATE(node);
420 	struct ng_mesg *resp = NULL;
421 	int error = 0;
422 	struct ng_mesg *msg;
423 
424 	NGI_GET_MSG(item, msg);
425 	switch (msg->header.typecookie) {
426 	case NGM_ETHER_COOKIE:
427 		switch (msg->header.cmd) {
428 		case NGM_ETHER_GET_IFNAME:
429 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
430 			if (resp == NULL) {
431 				error = ENOMEM;
432 				break;
433 			}
434 			strlcpy(resp->data, priv->ifp->if_xname, IFNAMSIZ);
435 			break;
436 		case NGM_ETHER_GET_IFINDEX:
437 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
438 			if (resp == NULL) {
439 				error = ENOMEM;
440 				break;
441 			}
442 			*((u_int32_t *)resp->data) = priv->ifp->if_index;
443 			break;
444 		case NGM_ETHER_GET_ENADDR:
445 			NG_MKRESPONSE(resp, msg, ETHER_ADDR_LEN, M_NOWAIT);
446 			if (resp == NULL) {
447 				error = ENOMEM;
448 				break;
449 			}
450 			bcopy(IF_LLADDR(priv->ifp),
451 			    resp->data, ETHER_ADDR_LEN);
452 			break;
453 		case NGM_ETHER_SET_ENADDR:
454 		    {
455 			if (msg->header.arglen != ETHER_ADDR_LEN) {
456 				error = EINVAL;
457 				break;
458 			}
459 			error = if_setlladdr(priv->ifp,
460 			    (u_char *)msg->data, ETHER_ADDR_LEN);
461 			break;
462 		    }
463 		case NGM_ETHER_GET_PROMISC:
464 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
465 			if (resp == NULL) {
466 				error = ENOMEM;
467 				break;
468 			}
469 			*((u_int32_t *)resp->data) = priv->promisc;
470 			break;
471 		case NGM_ETHER_SET_PROMISC:
472 		    {
473 			u_char want;
474 
475 			if (msg->header.arglen != sizeof(u_int32_t)) {
476 				error = EINVAL;
477 				break;
478 			}
479 			want = !!*((u_int32_t *)msg->data);
480 			if (want ^ priv->promisc) {
481 				if ((error = ifpromisc(priv->ifp, want)) != 0)
482 					break;
483 				priv->promisc = want;
484 			}
485 			break;
486 		    }
487 		case NGM_ETHER_GET_AUTOSRC:
488 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
489 			if (resp == NULL) {
490 				error = ENOMEM;
491 				break;
492 			}
493 			*((u_int32_t *)resp->data) = priv->autoSrcAddr;
494 			break;
495 		case NGM_ETHER_SET_AUTOSRC:
496 			if (msg->header.arglen != sizeof(u_int32_t)) {
497 				error = EINVAL;
498 				break;
499 			}
500 			priv->autoSrcAddr = !!*((u_int32_t *)msg->data);
501 			break;
502 		case NGM_ETHER_ADD_MULTI:
503 		    {
504 			struct sockaddr_dl sa_dl;
505 			struct ifmultiaddr *ifma;
506 
507 			if (msg->header.arglen != ETHER_ADDR_LEN) {
508 				error = EINVAL;
509 				break;
510 			}
511 			bzero(&sa_dl, sizeof(struct sockaddr_dl));
512 			sa_dl.sdl_len = sizeof(struct sockaddr_dl);
513 			sa_dl.sdl_family = AF_LINK;
514 			sa_dl.sdl_alen = ETHER_ADDR_LEN;
515 			bcopy((void *)msg->data, LLADDR(&sa_dl),
516 			    ETHER_ADDR_LEN);
517 			/*
518 			 * Netgraph is only permitted to join groups once
519 			 * via the if_addmulti() KPI, because it cannot hold
520 			 * struct ifmultiaddr * between calls. It may also
521 			 * lose a race while we check if the membership
522 			 * already exists.
523 			 */
524 			IF_ADDR_LOCK(priv->ifp);
525 			ifma = if_findmulti(priv->ifp,
526 			    (struct sockaddr *)&sa_dl);
527 			IF_ADDR_UNLOCK(priv->ifp);
528 			if (ifma != NULL) {
529 				error = EADDRINUSE;
530 			} else {
531 				error = if_addmulti(priv->ifp,
532 				    (struct sockaddr *)&sa_dl, &ifma);
533 			}
534 			break;
535 		    }
536 		case NGM_ETHER_DEL_MULTI:
537 		    {
538 			struct sockaddr_dl sa_dl;
539 
540 			if (msg->header.arglen != ETHER_ADDR_LEN) {
541 				error = EINVAL;
542 				break;
543 			}
544 			bzero(&sa_dl, sizeof(struct sockaddr_dl));
545 			sa_dl.sdl_len = sizeof(struct sockaddr_dl);
546 			sa_dl.sdl_family = AF_LINK;
547 			sa_dl.sdl_alen = ETHER_ADDR_LEN;
548 			bcopy((void *)msg->data, LLADDR(&sa_dl),
549 			    ETHER_ADDR_LEN);
550 			error = if_delmulti(priv->ifp,
551 			    (struct sockaddr *)&sa_dl);
552 			break;
553 		    }
554 		case NGM_ETHER_DETACH:
555 			ng_ether_detach(priv->ifp);
556 			break;
557 		default:
558 			error = EINVAL;
559 			break;
560 		}
561 		break;
562 	default:
563 		error = EINVAL;
564 		break;
565 	}
566 	NG_RESPOND_MSG(error, node, item, resp);
567 	NG_FREE_MSG(msg);
568 	return (error);
569 }
570 
571 /*
572  * Receive data on a hook.
573  */
574 static int
575 ng_ether_rcvdata(hook_p hook, item_p item)
576 {
577 	const node_p node = NG_HOOK_NODE(hook);
578 	const priv_p priv = NG_NODE_PRIVATE(node);
579 	struct mbuf *m;
580 
581 	NGI_GET_M(item, m);
582 	NG_FREE_ITEM(item);
583 
584 	if (hook == priv->lower || hook == priv->orphan)
585 		return ng_ether_rcv_lower(node, m);
586 	if (hook == priv->upper)
587 		return ng_ether_rcv_upper(node, m);
588 	panic("%s: weird hook", __func__);
589 #ifdef RESTARTABLE_PANICS /* so we don't get an error msg in LINT */
590 	return (0);
591 #endif
592 }
593 
594 /*
595  * Handle an mbuf received on the "lower" or "orphan" hook.
596  */
597 static int
598 ng_ether_rcv_lower(node_p node, struct mbuf *m)
599 {
600 	const priv_p priv = NG_NODE_PRIVATE(node);
601  	struct ifnet *const ifp = priv->ifp;
602 
603 	/* Check whether interface is ready for packets */
604 	if (!((ifp->if_flags & IFF_UP) &&
605 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
606 		NG_FREE_M(m);
607 		return (ENETDOWN);
608 	}
609 
610 	/* Make sure header is fully pulled up */
611 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
612 		NG_FREE_M(m);
613 		return (EINVAL);
614 	}
615 	if (m->m_len < sizeof(struct ether_header)
616 	    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
617 		return (ENOBUFS);
618 
619 	/* Drop in the MAC address if desired */
620 	if (priv->autoSrcAddr) {
621 
622 		/* Make the mbuf writable if it's not already */
623 		if (!M_WRITABLE(m)
624 		    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
625 			return (ENOBUFS);
626 
627 		/* Overwrite source MAC address */
628 		bcopy(IF_LLADDR(ifp),
629 		    mtod(m, struct ether_header *)->ether_shost,
630 		    ETHER_ADDR_LEN);
631 	}
632 
633 	/* Send it on its way */
634 	return ether_output_frame(ifp, m);
635 }
636 
637 /*
638  * Handle an mbuf received on the "upper" hook.
639  */
640 static int
641 ng_ether_rcv_upper(node_p node, struct mbuf *m)
642 {
643 	const priv_p priv = NG_NODE_PRIVATE(node);
644 	struct ifnet *ifp = priv->ifp;
645 
646 	/* Check length and pull off header */
647 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
648 		NG_FREE_M(m);
649 		return (EINVAL);
650 	}
651 	if (m->m_len < sizeof(struct ether_header) &&
652 	    (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
653 		return (ENOBUFS);
654 
655 	m->m_pkthdr.rcvif = ifp;
656 
657 	/* Pass the packet to the bridge, it may come back to us */
658 	if (ifp->if_bridge) {
659 		BRIDGE_INPUT(ifp, m);
660 		if (m == NULL)
661 			return (0);
662 	}
663 
664 	/* Route packet back in */
665 	ether_demux(ifp, m);
666 	return (0);
667 }
668 
669 /*
670  * Shutdown node. This resets the node but does not remove it
671  * unless the REALLY_DIE flag is set.
672  */
673 static int
674 ng_ether_shutdown(node_p node)
675 {
676 	const priv_p priv = NG_NODE_PRIVATE(node);
677 
678 	if (node->nd_flags & NGF_REALLY_DIE) {
679 		/*
680 		 * WE came here because the ethernet card is being unloaded,
681 		 * so stop being persistant.
682 		 * Actually undo all the things we did on creation.
683 		 * Assume the ifp has already been freed.
684 		 */
685 		NG_NODE_SET_PRIVATE(node, NULL);
686 		free(priv, M_NETGRAPH);
687 		NG_NODE_UNREF(node);	/* free node itself */
688 		return (0);
689 	}
690 	if (priv->promisc) {		/* disable promiscuous mode */
691 		(void)ifpromisc(priv->ifp, 0);
692 		priv->promisc = 0;
693 	}
694 	priv->autoSrcAddr = 1;		/* reset auto-src-addr flag */
695 	NG_NODE_REVIVE(node);		/* Signal ng_rmnode we are persisant */
696 
697 	return (0);
698 }
699 
700 /*
701  * Hook disconnection.
702  */
703 static int
704 ng_ether_disconnect(hook_p hook)
705 {
706 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
707 
708 	if (hook == priv->upper) {
709 		priv->upper = NULL;
710 		if (priv->ifp != NULL)		/* restore h/w csum */
711 			priv->ifp->if_hwassist = priv->hwassist;
712 	} else if (hook == priv->lower)
713 		priv->lower = NULL;
714 	else if (hook == priv->orphan)
715 		priv->orphan = NULL;
716 	else
717 		panic("%s: weird hook", __func__);
718 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
719 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
720 		ng_rmnode_self(NG_HOOK_NODE(hook));	/* reset node */
721 	return (0);
722 }
723 
724 /******************************************************************
725 		    	INITIALIZATION
726 ******************************************************************/
727 
728 /*
729  * Handle loading and unloading for this node type.
730  */
731 static int
732 ng_ether_mod_event(module_t mod, int event, void *data)
733 {
734 	struct ifnet *ifp;
735 	int error = 0;
736 	int s;
737 
738 	s = splnet();
739 	switch (event) {
740 	case MOD_LOAD:
741 
742 		/* Register function hooks */
743 		if (ng_ether_attach_p != NULL) {
744 			error = EEXIST;
745 			break;
746 		}
747 		ng_ether_attach_p = ng_ether_attach;
748 		ng_ether_detach_p = ng_ether_detach;
749 		ng_ether_output_p = ng_ether_output;
750 		ng_ether_input_p = ng_ether_input;
751 		ng_ether_input_orphan_p = ng_ether_input_orphan;
752 		ng_ether_link_state_p = ng_ether_link_state;
753 
754 		/* Create nodes for any already-existing Ethernet interfaces */
755 		IFNET_RLOCK();
756 		TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
757 			if (ifp->if_type == IFT_ETHER
758 			    || ifp->if_type == IFT_L2VLAN)
759 				ng_ether_attach(ifp);
760 		}
761 		IFNET_RUNLOCK();
762 		break;
763 
764 	case MOD_UNLOAD:
765 
766 		/*
767 		 * Note that the base code won't try to unload us until
768 		 * all nodes have been removed, and that can't happen
769 		 * until all Ethernet interfaces are removed. In any
770 		 * case, we know there are no nodes left if the action
771 		 * is MOD_UNLOAD, so there's no need to detach any nodes.
772 		 */
773 
774 		/* Unregister function hooks */
775 		ng_ether_attach_p = NULL;
776 		ng_ether_detach_p = NULL;
777 		ng_ether_output_p = NULL;
778 		ng_ether_input_p = NULL;
779 		ng_ether_input_orphan_p = NULL;
780 		ng_ether_link_state_p = NULL;
781 		break;
782 
783 	default:
784 		error = EOPNOTSUPP;
785 		break;
786 	}
787 	splx(s);
788 	return (error);
789 }
790 
791