xref: /freebsd/sys/netgraph/ng_ether.c (revision 48c5129f93c5eb5419c87b08e4677d51513f1dc0)
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/proc.h>
56 #include <sys/syslog.h>
57 #include <sys/socket.h>
58 #include <sys/taskqueue.h>
59 
60 #include <net/if.h>
61 #include <net/if_dl.h>
62 #include <net/if_types.h>
63 #include <net/if_arp.h>
64 #include <net/if_var.h>
65 #include <net/ethernet.h>
66 #include <net/if_bridgevar.h>
67 #include <net/vnet.h>
68 
69 #include <netgraph/ng_message.h>
70 #include <netgraph/netgraph.h>
71 #include <netgraph/ng_parse.h>
72 #include <netgraph/ng_ether.h>
73 
74 MODULE_VERSION(ng_ether, 1);
75 
76 #define IFP2NG(ifp)  (IFP2AC((ifp))->ac_netgraph)
77 
78 /* Per-node private data */
79 struct private {
80 	struct ifnet	*ifp;		/* associated interface */
81 	hook_p		upper;		/* upper hook connection */
82 	hook_p		lower;		/* lower hook connection */
83 	hook_p		orphan;		/* orphan hook connection */
84 	u_char		autoSrcAddr;	/* always overwrite source address */
85 	u_char		promisc;	/* promiscuous mode enabled */
86 	u_long		hwassist;	/* hardware checksum capabilities */
87 	u_int		flags;		/* flags e.g. really die */
88 };
89 typedef struct private *priv_p;
90 
91 /* Hook pointers used by if_ethersubr.c to callback to netgraph */
92 extern	void	(*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
93 extern	void	(*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
94 extern	int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
95 extern	void	(*ng_ether_attach_p)(struct ifnet *ifp);
96 extern	void	(*ng_ether_detach_p)(struct ifnet *ifp);
97 extern	void	(*ng_ether_link_state_p)(struct ifnet *ifp, int state);
98 
99 /* Functional hooks called from if_ethersubr.c */
100 static void	ng_ether_input(struct ifnet *ifp, struct mbuf **mp);
101 static void	ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m);
102 static int	ng_ether_output(struct ifnet *ifp, struct mbuf **mp);
103 static void	ng_ether_attach(struct ifnet *ifp);
104 static void	ng_ether_detach(struct ifnet *ifp);
105 static void	ng_ether_link_state(struct ifnet *ifp, int state);
106 
107 /* Other functions */
108 static int	ng_ether_rcv_lower(hook_p node, item_p item);
109 static int	ng_ether_rcv_upper(hook_p node, item_p item);
110 
111 /* Netgraph node methods */
112 static ng_constructor_t	ng_ether_constructor;
113 static ng_rcvmsg_t	ng_ether_rcvmsg;
114 static ng_shutdown_t	ng_ether_shutdown;
115 static ng_newhook_t	ng_ether_newhook;
116 static ng_rcvdata_t	ng_ether_rcvdata;
117 static ng_disconnect_t	ng_ether_disconnect;
118 static int		ng_ether_mod_event(module_t mod, int event, void *data);
119 
120 /* List of commands and how to convert arguments to/from ASCII */
121 static const struct ng_cmdlist ng_ether_cmdlist[] = {
122 	{
123 	  NGM_ETHER_COOKIE,
124 	  NGM_ETHER_GET_IFNAME,
125 	  "getifname",
126 	  NULL,
127 	  &ng_parse_string_type
128 	},
129 	{
130 	  NGM_ETHER_COOKIE,
131 	  NGM_ETHER_GET_IFINDEX,
132 	  "getifindex",
133 	  NULL,
134 	  &ng_parse_int32_type
135 	},
136 	{
137 	  NGM_ETHER_COOKIE,
138 	  NGM_ETHER_GET_ENADDR,
139 	  "getenaddr",
140 	  NULL,
141 	  &ng_parse_enaddr_type
142 	},
143 	{
144 	  NGM_ETHER_COOKIE,
145 	  NGM_ETHER_SET_ENADDR,
146 	  "setenaddr",
147 	  &ng_parse_enaddr_type,
148 	  NULL
149 	},
150 	{
151 	  NGM_ETHER_COOKIE,
152 	  NGM_ETHER_GET_PROMISC,
153 	  "getpromisc",
154 	  NULL,
155 	  &ng_parse_int32_type
156 	},
157 	{
158 	  NGM_ETHER_COOKIE,
159 	  NGM_ETHER_SET_PROMISC,
160 	  "setpromisc",
161 	  &ng_parse_int32_type,
162 	  NULL
163 	},
164 	{
165 	  NGM_ETHER_COOKIE,
166 	  NGM_ETHER_GET_AUTOSRC,
167 	  "getautosrc",
168 	  NULL,
169 	  &ng_parse_int32_type
170 	},
171 	{
172 	  NGM_ETHER_COOKIE,
173 	  NGM_ETHER_SET_AUTOSRC,
174 	  "setautosrc",
175 	  &ng_parse_int32_type,
176 	  NULL
177 	},
178 	{
179 	  NGM_ETHER_COOKIE,
180 	  NGM_ETHER_ADD_MULTI,
181 	  "addmulti",
182 	  &ng_parse_enaddr_type,
183 	  NULL
184 	},
185 	{
186 	  NGM_ETHER_COOKIE,
187 	  NGM_ETHER_DEL_MULTI,
188 	  "delmulti",
189 	  &ng_parse_enaddr_type,
190 	  NULL
191 	},
192 	{
193 	  NGM_ETHER_COOKIE,
194 	  NGM_ETHER_DETACH,
195 	  "detach",
196 	  NULL,
197 	  NULL
198 	},
199 	{ 0 }
200 };
201 
202 static struct ng_type ng_ether_typestruct = {
203 	.version =	NG_ABI_VERSION,
204 	.name =		NG_ETHER_NODE_TYPE,
205 	.mod_event =	ng_ether_mod_event,
206 	.constructor =	ng_ether_constructor,
207 	.rcvmsg =	ng_ether_rcvmsg,
208 	.shutdown =	ng_ether_shutdown,
209 	.newhook =	ng_ether_newhook,
210 	.rcvdata =	ng_ether_rcvdata,
211 	.disconnect =	ng_ether_disconnect,
212 	.cmdlist =	ng_ether_cmdlist,
213 };
214 NETGRAPH_INIT(ether, &ng_ether_typestruct);
215 
216 /******************************************************************
217 		    ETHERNET FUNCTION HOOKS
218 ******************************************************************/
219 
220 /*
221  * Handle a packet that has come in on an interface. We get to
222  * look at it here before any upper layer protocols do.
223  */
224 static void
225 ng_ether_input(struct ifnet *ifp, struct mbuf **mp)
226 {
227 	const node_p node = IFP2NG(ifp);
228 	const priv_p priv = NG_NODE_PRIVATE(node);
229 	int error;
230 
231 	/* If "lower" hook not connected, let packet continue */
232 	if (priv->lower == NULL)
233 		return;
234 	NG_SEND_DATA_ONLY(error, priv->lower, *mp);	/* sets *mp = NULL */
235 }
236 
237 /*
238  * Handle a packet that has come in on an interface, and which
239  * does not match any of our known protocols (an ``orphan'').
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_OUTBOUND_THREAD_REF();
273 	NG_SEND_DATA_ONLY(error, priv->upper, *mp);
274 	NG_OUTBOUND_THREAD_UNREF();
275 	return (error);
276 }
277 
278 /*
279  * A new Ethernet interface has been attached.
280  * Create a new node for it, etc.
281  */
282 static void
283 ng_ether_attach(struct ifnet *ifp)
284 {
285 	priv_p priv;
286 	node_p node;
287 
288 	/*
289 	 * Do not create / attach an ether node to this ifnet if
290 	 * a netgraph node with the same name already exists.
291 	 * This should prevent ether nodes to become attached to
292 	 * eiface nodes, which may be problematic due to naming
293 	 * clashes.
294 	 */
295 	if ((node = ng_name2noderef(NULL, ifp->if_xname)) != NULL) {
296 		NG_NODE_UNREF(node);
297 		return;
298 	}
299 
300 	/* Create node */
301 	KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
302 	if (ng_make_node_common(&ng_ether_typestruct, &node) != 0) {
303 		log(LOG_ERR, "%s: can't %s for %s\n",
304 		    __func__, "create node", ifp->if_xname);
305 		return;
306 	}
307 
308 	/* Allocate private data */
309 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
310 	if (priv == NULL) {
311 		log(LOG_ERR, "%s: can't %s for %s\n",
312 		    __func__, "allocate memory", ifp->if_xname);
313 		NG_NODE_UNREF(node);
314 		return;
315 	}
316 	NG_NODE_SET_PRIVATE(node, priv);
317 	priv->ifp = ifp;
318 	IFP2NG(ifp) = node;
319 	priv->hwassist = ifp->if_hwassist;
320 
321 	/* Try to give the node the same name as the interface */
322 	if (ng_name_node(node, ifp->if_xname) != 0) {
323 		log(LOG_WARNING, "%s: can't name node %s\n",
324 		    __func__, ifp->if_xname);
325 	}
326 }
327 
328 /*
329  * An Ethernet interface is being detached.
330  * REALLY Destroy its node.
331  */
332 static void
333 ng_ether_detach(struct ifnet *ifp)
334 {
335 	const node_p node = IFP2NG(ifp);
336 	const priv_p priv = NG_NODE_PRIVATE(node);
337 
338 	taskqueue_drain(taskqueue_swi, &ifp->if_linktask);
339 	NG_NODE_REALLY_DIE(node);	/* Force real removal of node */
340 	/*
341 	 * We can't assume the ifnet is still around when we run shutdown
342 	 * So zap it now. XXX We HOPE that anything running at this time
343 	 * handles it (as it should in the non netgraph case).
344 	 */
345 	IFP2NG(ifp) = NULL;
346 	priv->ifp = NULL;	/* XXX race if interrupted an output packet */
347 	ng_rmnode_self(node);		/* remove all netgraph parts */
348 }
349 
350 /*
351  * Notify graph about link event.
352  * if_link_state_change() has already checked that the state has changed.
353  */
354 static void
355 ng_ether_link_state(struct ifnet *ifp, int state)
356 {
357 	const node_p node = IFP2NG(ifp);
358 	const priv_p priv = NG_NODE_PRIVATE(node);
359 	struct ng_mesg *msg;
360 	int cmd, dummy_error = 0;
361 
362 	if (state == LINK_STATE_UP)
363 		cmd = NGM_LINK_IS_UP;
364 	else if (state == LINK_STATE_DOWN)
365 		cmd = NGM_LINK_IS_DOWN;
366 	else
367 		return;
368 
369 	if (priv->lower != NULL) {
370 		NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
371 		if (msg != NULL)
372 			NG_SEND_MSG_HOOK(dummy_error, node, msg, priv->lower, 0);
373 	}
374 	if (priv->orphan != NULL) {
375 		NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
376 		if (msg != NULL)
377 			NG_SEND_MSG_HOOK(dummy_error, node, msg, priv->orphan, 0);
378 	}
379 }
380 
381 /******************************************************************
382 		    NETGRAPH NODE METHODS
383 ******************************************************************/
384 
385 /*
386  * It is not possible or allowable to create a node of this type.
387  * Nodes get created when the interface is attached (or, when
388  * this node type's KLD is loaded).
389  */
390 static int
391 ng_ether_constructor(node_p node)
392 {
393 	return (EINVAL);
394 }
395 
396 /*
397  * Check for attaching a new hook.
398  */
399 static	int
400 ng_ether_newhook(node_p node, hook_p hook, const char *name)
401 {
402 	const priv_p priv = NG_NODE_PRIVATE(node);
403 	hook_p *hookptr;
404 
405 	/* Divert hook is an alias for lower */
406 	if (strcmp(name, NG_ETHER_HOOK_DIVERT) == 0)
407 		name = NG_ETHER_HOOK_LOWER;
408 
409 	/* Which hook? */
410 	if (strcmp(name, NG_ETHER_HOOK_UPPER) == 0) {
411 		hookptr = &priv->upper;
412 		NG_HOOK_SET_RCVDATA(hook, ng_ether_rcv_upper);
413 		NG_HOOK_SET_TO_INBOUND(hook);
414 	} else if (strcmp(name, NG_ETHER_HOOK_LOWER) == 0) {
415 		hookptr = &priv->lower;
416 		NG_HOOK_SET_RCVDATA(hook, ng_ether_rcv_lower);
417 	} else if (strcmp(name, NG_ETHER_HOOK_ORPHAN) == 0) {
418 		hookptr = &priv->orphan;
419 		NG_HOOK_SET_RCVDATA(hook, ng_ether_rcv_lower);
420 	} else
421 		return (EINVAL);
422 
423 	/* Check if already connected (shouldn't be, but doesn't hurt) */
424 	if (*hookptr != NULL)
425 		return (EISCONN);
426 
427 	/* Disable hardware checksums while 'upper' hook is connected */
428 	if (hookptr == &priv->upper)
429 		priv->ifp->if_hwassist = 0;
430 	NG_HOOK_HI_STACK(hook);
431 	/* OK */
432 	*hookptr = hook;
433 	return (0);
434 }
435 
436 /*
437  * Receive an incoming control message.
438  */
439 static int
440 ng_ether_rcvmsg(node_p node, item_p item, hook_p lasthook)
441 {
442 	const priv_p priv = NG_NODE_PRIVATE(node);
443 	struct ng_mesg *resp = NULL;
444 	int error = 0;
445 	struct ng_mesg *msg;
446 
447 	NGI_GET_MSG(item, msg);
448 	switch (msg->header.typecookie) {
449 	case NGM_ETHER_COOKIE:
450 		switch (msg->header.cmd) {
451 		case NGM_ETHER_GET_IFNAME:
452 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
453 			if (resp == NULL) {
454 				error = ENOMEM;
455 				break;
456 			}
457 			strlcpy(resp->data, priv->ifp->if_xname, IFNAMSIZ);
458 			break;
459 		case NGM_ETHER_GET_IFINDEX:
460 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
461 			if (resp == NULL) {
462 				error = ENOMEM;
463 				break;
464 			}
465 			*((u_int32_t *)resp->data) = priv->ifp->if_index;
466 			break;
467 		case NGM_ETHER_GET_ENADDR:
468 			NG_MKRESPONSE(resp, msg, ETHER_ADDR_LEN, M_NOWAIT);
469 			if (resp == NULL) {
470 				error = ENOMEM;
471 				break;
472 			}
473 			bcopy(IF_LLADDR(priv->ifp),
474 			    resp->data, ETHER_ADDR_LEN);
475 			break;
476 		case NGM_ETHER_SET_ENADDR:
477 		    {
478 			if (msg->header.arglen != ETHER_ADDR_LEN) {
479 				error = EINVAL;
480 				break;
481 			}
482 			error = if_setlladdr(priv->ifp,
483 			    (u_char *)msg->data, ETHER_ADDR_LEN);
484 			EVENTHANDLER_INVOKE(iflladdr_event, priv->ifp);
485 			break;
486 		    }
487 		case NGM_ETHER_GET_PROMISC:
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->promisc;
494 			break;
495 		case NGM_ETHER_SET_PROMISC:
496 		    {
497 			u_char want;
498 
499 			if (msg->header.arglen != sizeof(u_int32_t)) {
500 				error = EINVAL;
501 				break;
502 			}
503 			want = !!*((u_int32_t *)msg->data);
504 			if (want ^ priv->promisc) {
505 				if ((error = ifpromisc(priv->ifp, want)) != 0)
506 					break;
507 				priv->promisc = want;
508 			}
509 			break;
510 		    }
511 		case NGM_ETHER_GET_AUTOSRC:
512 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
513 			if (resp == NULL) {
514 				error = ENOMEM;
515 				break;
516 			}
517 			*((u_int32_t *)resp->data) = priv->autoSrcAddr;
518 			break;
519 		case NGM_ETHER_SET_AUTOSRC:
520 			if (msg->header.arglen != sizeof(u_int32_t)) {
521 				error = EINVAL;
522 				break;
523 			}
524 			priv->autoSrcAddr = !!*((u_int32_t *)msg->data);
525 			break;
526 		case NGM_ETHER_ADD_MULTI:
527 		    {
528 			struct sockaddr_dl sa_dl;
529 			struct ifmultiaddr *ifma;
530 
531 			if (msg->header.arglen != ETHER_ADDR_LEN) {
532 				error = EINVAL;
533 				break;
534 			}
535 			bzero(&sa_dl, sizeof(struct sockaddr_dl));
536 			sa_dl.sdl_len = sizeof(struct sockaddr_dl);
537 			sa_dl.sdl_family = AF_LINK;
538 			sa_dl.sdl_alen = ETHER_ADDR_LEN;
539 			bcopy((void *)msg->data, LLADDR(&sa_dl),
540 			    ETHER_ADDR_LEN);
541 			/*
542 			 * Netgraph is only permitted to join groups once
543 			 * via the if_addmulti() KPI, because it cannot hold
544 			 * struct ifmultiaddr * between calls. It may also
545 			 * lose a race while we check if the membership
546 			 * already exists.
547 			 */
548 			if_maddr_rlock(priv->ifp);
549 			ifma = if_findmulti(priv->ifp,
550 			    (struct sockaddr *)&sa_dl);
551 			if_maddr_runlock(priv->ifp);
552 			if (ifma != NULL) {
553 				error = EADDRINUSE;
554 			} else {
555 				error = if_addmulti(priv->ifp,
556 				    (struct sockaddr *)&sa_dl, &ifma);
557 			}
558 			break;
559 		    }
560 		case NGM_ETHER_DEL_MULTI:
561 		    {
562 			struct sockaddr_dl sa_dl;
563 
564 			if (msg->header.arglen != ETHER_ADDR_LEN) {
565 				error = EINVAL;
566 				break;
567 			}
568 			bzero(&sa_dl, sizeof(struct sockaddr_dl));
569 			sa_dl.sdl_len = sizeof(struct sockaddr_dl);
570 			sa_dl.sdl_family = AF_LINK;
571 			sa_dl.sdl_alen = ETHER_ADDR_LEN;
572 			bcopy((void *)msg->data, LLADDR(&sa_dl),
573 			    ETHER_ADDR_LEN);
574 			error = if_delmulti(priv->ifp,
575 			    (struct sockaddr *)&sa_dl);
576 			break;
577 		    }
578 		case NGM_ETHER_DETACH:
579 			ng_ether_detach(priv->ifp);
580 			break;
581 		default:
582 			error = EINVAL;
583 			break;
584 		}
585 		break;
586 	default:
587 		error = EINVAL;
588 		break;
589 	}
590 	NG_RESPOND_MSG(error, node, item, resp);
591 	NG_FREE_MSG(msg);
592 	return (error);
593 }
594 
595 /*
596  * Receive data on a hook.
597  * Since we use per-hook recveive methods this should never be called.
598  */
599 static int
600 ng_ether_rcvdata(hook_p hook, item_p item)
601 {
602 	NG_FREE_ITEM(item);
603 
604 	panic("%s: weird hook", __func__);
605 }
606 
607 /*
608  * Handle an mbuf received on the "lower" or "orphan" hook.
609  */
610 static int
611 ng_ether_rcv_lower(hook_p hook, item_p item)
612 {
613 	struct mbuf *m;
614 	const node_p node = NG_HOOK_NODE(hook);
615 	const priv_p priv = NG_NODE_PRIVATE(node);
616  	struct ifnet *const ifp = priv->ifp;
617 
618 	NGI_GET_M(item, m);
619 	NG_FREE_ITEM(item);
620 
621 	/* Check whether interface is ready for packets */
622 
623 	if (!((ifp->if_flags & IFF_UP) &&
624 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
625 		NG_FREE_M(m);
626 		return (ENETDOWN);
627 	}
628 
629 	/* Make sure header is fully pulled up */
630 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
631 		NG_FREE_M(m);
632 		return (EINVAL);
633 	}
634 	if (m->m_len < sizeof(struct ether_header)
635 	    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
636 		return (ENOBUFS);
637 
638 	/* Drop in the MAC address if desired */
639 	if (priv->autoSrcAddr) {
640 
641 		/* Make the mbuf writable if it's not already */
642 		if (!M_WRITABLE(m)
643 		    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
644 			return (ENOBUFS);
645 
646 		/* Overwrite source MAC address */
647 		bcopy(IF_LLADDR(ifp),
648 		    mtod(m, struct ether_header *)->ether_shost,
649 		    ETHER_ADDR_LEN);
650 	}
651 
652 	/* Send it on its way */
653 	return ether_output_frame(ifp, m);
654 }
655 
656 /*
657  * Handle an mbuf received on the "upper" hook.
658  */
659 static int
660 ng_ether_rcv_upper(hook_p hook, item_p item)
661 {
662 	struct mbuf *m;
663 	const node_p node = NG_HOOK_NODE(hook);
664 	const priv_p priv = NG_NODE_PRIVATE(node);
665 	struct ifnet *ifp = priv->ifp;
666 
667 	NGI_GET_M(item, m);
668 	NG_FREE_ITEM(item);
669 
670 	/* Check length and pull off header */
671 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
672 		NG_FREE_M(m);
673 		return (EINVAL);
674 	}
675 	if (m->m_len < sizeof(struct ether_header) &&
676 	    (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
677 		return (ENOBUFS);
678 
679 	m->m_pkthdr.rcvif = ifp;
680 
681 	/* Pass the packet to the bridge, it may come back to us */
682 	if (ifp->if_bridge) {
683 		BRIDGE_INPUT(ifp, m);
684 		if (m == NULL)
685 			return (0);
686 	}
687 
688 	/* Route packet back in */
689 	ether_demux(ifp, m);
690 	return (0);
691 }
692 
693 /*
694  * Shutdown node. This resets the node but does not remove it
695  * unless the REALLY_DIE flag is set.
696  */
697 static int
698 ng_ether_shutdown(node_p node)
699 {
700 	const priv_p priv = NG_NODE_PRIVATE(node);
701 
702 	if (node->nd_flags & NGF_REALLY_DIE) {
703 		/*
704 		 * WE came here because the ethernet card is being unloaded,
705 		 * so stop being persistant.
706 		 * Actually undo all the things we did on creation.
707 		 * Assume the ifp has already been freed.
708 		 */
709 		NG_NODE_SET_PRIVATE(node, NULL);
710 		free(priv, M_NETGRAPH);
711 		NG_NODE_UNREF(node);	/* free node itself */
712 		return (0);
713 	}
714 	if (priv->promisc) {		/* disable promiscuous mode */
715 		(void)ifpromisc(priv->ifp, 0);
716 		priv->promisc = 0;
717 	}
718 	NG_NODE_REVIVE(node);		/* Signal ng_rmnode we are persisant */
719 
720 	return (0);
721 }
722 
723 /*
724  * Hook disconnection.
725  */
726 static int
727 ng_ether_disconnect(hook_p hook)
728 {
729 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
730 
731 	if (hook == priv->upper) {
732 		priv->upper = NULL;
733 		if (priv->ifp != NULL)		/* restore h/w csum */
734 			priv->ifp->if_hwassist = priv->hwassist;
735 	} else if (hook == priv->lower)
736 		priv->lower = NULL;
737 	else if (hook == priv->orphan)
738 		priv->orphan = NULL;
739 	else
740 		panic("%s: weird hook", __func__);
741 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
742 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
743 		ng_rmnode_self(NG_HOOK_NODE(hook));	/* reset node */
744 	return (0);
745 }
746 
747 /******************************************************************
748 		    	INITIALIZATION
749 ******************************************************************/
750 
751 /*
752  * Handle loading and unloading for this node type.
753  */
754 static int
755 ng_ether_mod_event(module_t mod, int event, void *data)
756 {
757 	int error = 0;
758 
759 	switch (event) {
760 	case MOD_LOAD:
761 
762 		/* Register function hooks */
763 		if (ng_ether_attach_p != NULL) {
764 			error = EEXIST;
765 			break;
766 		}
767 		ng_ether_attach_p = ng_ether_attach;
768 		ng_ether_detach_p = ng_ether_detach;
769 		ng_ether_output_p = ng_ether_output;
770 		ng_ether_input_p = ng_ether_input;
771 		ng_ether_input_orphan_p = ng_ether_input_orphan;
772 		ng_ether_link_state_p = ng_ether_link_state;
773 
774 		break;
775 
776 	case MOD_UNLOAD:
777 
778 		/*
779 		 * Note that the base code won't try to unload us until
780 		 * all nodes have been removed, and that can't happen
781 		 * until all Ethernet interfaces are removed. In any
782 		 * case, we know there are no nodes left if the action
783 		 * is MOD_UNLOAD, so there's no need to detach any nodes.
784 		 */
785 
786 		/* Unregister function hooks */
787 		ng_ether_attach_p = NULL;
788 		ng_ether_detach_p = NULL;
789 		ng_ether_output_p = NULL;
790 		ng_ether_input_p = NULL;
791 		ng_ether_input_orphan_p = NULL;
792 		ng_ether_link_state_p = NULL;
793 		break;
794 
795 	default:
796 		error = EOPNOTSUPP;
797 		break;
798 	}
799 	return (error);
800 }
801 
802 static void
803 vnet_ng_ether_init(const void *unused)
804 {
805 	struct ifnet *ifp;
806 
807 	/* If module load was rejected, don't attach to vnets. */
808 	if (ng_ether_attach_p != ng_ether_attach)
809 		return;
810 
811 	/* Create nodes for any already-existing Ethernet interfaces. */
812 	IFNET_RLOCK();
813 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
814 		if (ifp->if_type == IFT_ETHER
815 		    || ifp->if_type == IFT_L2VLAN)
816 			ng_ether_attach(ifp);
817 	}
818 	IFNET_RUNLOCK();
819 }
820 VNET_SYSINIT(vnet_ng_ether_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
821     vnet_ng_ether_init, NULL);
822