xref: /freebsd/sys/netgraph/ng_ether.c (revision ab2043b81eaba0d7d7769b4a58b2b6d17bc464a3)
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  * NOTE: this function will get called at splimp()
225  */
226 static void
227 ng_ether_input(struct ifnet *ifp, struct mbuf **mp)
228 {
229 	const node_p node = IFP2NG(ifp);
230 	const priv_p priv = NG_NODE_PRIVATE(node);
231 	int error;
232 
233 	/* If "lower" hook not connected, let packet continue */
234 	if (priv->lower == NULL)
235 		return;
236 	NG_SEND_DATA_ONLY(error, priv->lower, *mp);	/* sets *mp = NULL */
237 }
238 
239 /*
240  * Handle a packet that has come in on an interface, and which
241  * does not match any of our known protocols (an ``orphan'').
242  *
243  * NOTE: this function will get called at splimp()
244  */
245 static void
246 ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m)
247 {
248 	const node_p node = IFP2NG(ifp);
249 	const priv_p priv = NG_NODE_PRIVATE(node);
250 	int error;
251 
252 	/* If "orphan" hook not connected, discard packet */
253 	if (priv->orphan == NULL) {
254 		m_freem(m);
255 		return;
256 	}
257 	NG_SEND_DATA_ONLY(error, priv->orphan, m);
258 }
259 
260 /*
261  * Handle a packet that is going out on an interface.
262  * The Ethernet header is already attached to the mbuf.
263  */
264 static int
265 ng_ether_output(struct ifnet *ifp, struct mbuf **mp)
266 {
267 	const node_p node = IFP2NG(ifp);
268 	const priv_p priv = NG_NODE_PRIVATE(node);
269 	int error = 0;
270 
271 	/* If "upper" hook not connected, let packet continue */
272 	if (priv->upper == NULL)
273 		return (0);
274 
275 	/* Send it out "upper" hook */
276 	NG_OUTBOUND_THREAD_REF();
277 	NG_SEND_DATA_ONLY(error, priv->upper, *mp);
278 	NG_OUTBOUND_THREAD_UNREF();
279 	return (error);
280 }
281 
282 /*
283  * A new Ethernet interface has been attached.
284  * Create a new node for it, etc.
285  */
286 static void
287 ng_ether_attach(struct ifnet *ifp)
288 {
289 	priv_p priv;
290 	node_p node;
291 
292 	/*
293 	 * Do not create / attach an ether node to this ifnet if
294 	 * a netgraph node with the same name already exists.
295 	 * This should prevent ether nodes to become attached to
296 	 * eiface nodes, which may be problematic due to naming
297 	 * clashes.
298 	 */
299 	if ((node = ng_name2noderef(NULL, ifp->if_xname)) != NULL) {
300 		NG_NODE_UNREF(node);
301 		return;
302 	}
303 
304 	/* Create node */
305 	KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
306 	if (ng_make_node_common(&ng_ether_typestruct, &node) != 0) {
307 		log(LOG_ERR, "%s: can't %s for %s\n",
308 		    __func__, "create node", ifp->if_xname);
309 		return;
310 	}
311 
312 	/* Allocate private data */
313 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
314 	if (priv == NULL) {
315 		log(LOG_ERR, "%s: can't %s for %s\n",
316 		    __func__, "allocate memory", ifp->if_xname);
317 		NG_NODE_UNREF(node);
318 		return;
319 	}
320 	NG_NODE_SET_PRIVATE(node, priv);
321 	priv->ifp = ifp;
322 	IFP2NG(ifp) = node;
323 	priv->hwassist = ifp->if_hwassist;
324 
325 	/* Try to give the node the same name as the interface */
326 	if (ng_name_node(node, ifp->if_xname) != 0) {
327 		log(LOG_WARNING, "%s: can't name node %s\n",
328 		    __func__, ifp->if_xname);
329 	}
330 }
331 
332 /*
333  * An Ethernet interface is being detached.
334  * REALLY Destroy its node.
335  */
336 static void
337 ng_ether_detach(struct ifnet *ifp)
338 {
339 	const node_p node = IFP2NG(ifp);
340 	const priv_p priv = NG_NODE_PRIVATE(node);
341 
342 	taskqueue_drain(taskqueue_swi, &ifp->if_linktask);
343 	NG_NODE_REALLY_DIE(node);	/* Force real removal of node */
344 	/*
345 	 * We can't assume the ifnet is still around when we run shutdown
346 	 * So zap it now. XXX We HOPE that anything running at this time
347 	 * handles it (as it should in the non netgraph case).
348 	 */
349 	IFP2NG(ifp) = NULL;
350 	priv->ifp = NULL;	/* XXX race if interrupted an output packet */
351 	ng_rmnode_self(node);		/* remove all netgraph parts */
352 }
353 
354 /*
355  * Notify graph about link event.
356  * if_link_state_change() has already checked that the state has changed.
357  */
358 static void
359 ng_ether_link_state(struct ifnet *ifp, int state)
360 {
361 	const node_p node = IFP2NG(ifp);
362 	const priv_p priv = NG_NODE_PRIVATE(node);
363 	struct ng_mesg *msg;
364 	int cmd, dummy_error = 0;
365 
366 	if (state == LINK_STATE_UP)
367 		cmd = NGM_LINK_IS_UP;
368 	else if (state == LINK_STATE_DOWN)
369 		cmd = NGM_LINK_IS_DOWN;
370 	else
371 		return;
372 
373 	if (priv->lower != NULL) {
374 		NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
375 		if (msg != NULL)
376 			NG_SEND_MSG_HOOK(dummy_error, node, msg, priv->lower, 0);
377 	}
378 	if (priv->orphan != NULL) {
379 		NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
380 		if (msg != NULL)
381 			NG_SEND_MSG_HOOK(dummy_error, node, msg, priv->orphan, 0);
382 	}
383 }
384 
385 /******************************************************************
386 		    NETGRAPH NODE METHODS
387 ******************************************************************/
388 
389 /*
390  * It is not possible or allowable to create a node of this type.
391  * Nodes get created when the interface is attached (or, when
392  * this node type's KLD is loaded).
393  */
394 static int
395 ng_ether_constructor(node_p node)
396 {
397 	return (EINVAL);
398 }
399 
400 /*
401  * Check for attaching a new hook.
402  */
403 static	int
404 ng_ether_newhook(node_p node, hook_p hook, const char *name)
405 {
406 	const priv_p priv = NG_NODE_PRIVATE(node);
407 	hook_p *hookptr;
408 
409 	/* Divert hook is an alias for lower */
410 	if (strcmp(name, NG_ETHER_HOOK_DIVERT) == 0)
411 		name = NG_ETHER_HOOK_LOWER;
412 
413 	/* Which hook? */
414 	if (strcmp(name, NG_ETHER_HOOK_UPPER) == 0) {
415 		hookptr = &priv->upper;
416 		NG_HOOK_SET_RCVDATA(hook, ng_ether_rcv_upper);
417 		NG_HOOK_SET_TO_INBOUND(hook);
418 	} else if (strcmp(name, NG_ETHER_HOOK_LOWER) == 0) {
419 		hookptr = &priv->lower;
420 		NG_HOOK_SET_RCVDATA(hook, ng_ether_rcv_lower);
421 	} else if (strcmp(name, NG_ETHER_HOOK_ORPHAN) == 0) {
422 		hookptr = &priv->orphan;
423 		NG_HOOK_SET_RCVDATA(hook, ng_ether_rcv_lower);
424 	} else
425 		return (EINVAL);
426 
427 	/* Check if already connected (shouldn't be, but doesn't hurt) */
428 	if (*hookptr != NULL)
429 		return (EISCONN);
430 
431 	/* Disable hardware checksums while 'upper' hook is connected */
432 	if (hookptr == &priv->upper)
433 		priv->ifp->if_hwassist = 0;
434 	NG_HOOK_HI_STACK(hook);
435 	/* OK */
436 	*hookptr = hook;
437 	return (0);
438 }
439 
440 /*
441  * Receive an incoming control message.
442  */
443 static int
444 ng_ether_rcvmsg(node_p node, item_p item, hook_p lasthook)
445 {
446 	const priv_p priv = NG_NODE_PRIVATE(node);
447 	struct ng_mesg *resp = NULL;
448 	int error = 0;
449 	struct ng_mesg *msg;
450 
451 	NGI_GET_MSG(item, msg);
452 	switch (msg->header.typecookie) {
453 	case NGM_ETHER_COOKIE:
454 		switch (msg->header.cmd) {
455 		case NGM_ETHER_GET_IFNAME:
456 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
457 			if (resp == NULL) {
458 				error = ENOMEM;
459 				break;
460 			}
461 			strlcpy(resp->data, priv->ifp->if_xname, IFNAMSIZ);
462 			break;
463 		case NGM_ETHER_GET_IFINDEX:
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->ifp->if_index;
470 			break;
471 		case NGM_ETHER_GET_ENADDR:
472 			NG_MKRESPONSE(resp, msg, ETHER_ADDR_LEN, M_NOWAIT);
473 			if (resp == NULL) {
474 				error = ENOMEM;
475 				break;
476 			}
477 			bcopy(IF_LLADDR(priv->ifp),
478 			    resp->data, ETHER_ADDR_LEN);
479 			break;
480 		case NGM_ETHER_SET_ENADDR:
481 		    {
482 			if (msg->header.arglen != ETHER_ADDR_LEN) {
483 				error = EINVAL;
484 				break;
485 			}
486 			error = if_setlladdr(priv->ifp,
487 			    (u_char *)msg->data, ETHER_ADDR_LEN);
488 			EVENTHANDLER_INVOKE(iflladdr_event, priv->ifp);
489 			break;
490 		    }
491 		case NGM_ETHER_GET_PROMISC:
492 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
493 			if (resp == NULL) {
494 				error = ENOMEM;
495 				break;
496 			}
497 			*((u_int32_t *)resp->data) = priv->promisc;
498 			break;
499 		case NGM_ETHER_SET_PROMISC:
500 		    {
501 			u_char want;
502 
503 			if (msg->header.arglen != sizeof(u_int32_t)) {
504 				error = EINVAL;
505 				break;
506 			}
507 			want = !!*((u_int32_t *)msg->data);
508 			if (want ^ priv->promisc) {
509 				if ((error = ifpromisc(priv->ifp, want)) != 0)
510 					break;
511 				priv->promisc = want;
512 			}
513 			break;
514 		    }
515 		case NGM_ETHER_GET_AUTOSRC:
516 			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
517 			if (resp == NULL) {
518 				error = ENOMEM;
519 				break;
520 			}
521 			*((u_int32_t *)resp->data) = priv->autoSrcAddr;
522 			break;
523 		case NGM_ETHER_SET_AUTOSRC:
524 			if (msg->header.arglen != sizeof(u_int32_t)) {
525 				error = EINVAL;
526 				break;
527 			}
528 			priv->autoSrcAddr = !!*((u_int32_t *)msg->data);
529 			break;
530 		case NGM_ETHER_ADD_MULTI:
531 		    {
532 			struct sockaddr_dl sa_dl;
533 			struct ifmultiaddr *ifma;
534 
535 			if (msg->header.arglen != ETHER_ADDR_LEN) {
536 				error = EINVAL;
537 				break;
538 			}
539 			bzero(&sa_dl, sizeof(struct sockaddr_dl));
540 			sa_dl.sdl_len = sizeof(struct sockaddr_dl);
541 			sa_dl.sdl_family = AF_LINK;
542 			sa_dl.sdl_alen = ETHER_ADDR_LEN;
543 			bcopy((void *)msg->data, LLADDR(&sa_dl),
544 			    ETHER_ADDR_LEN);
545 			/*
546 			 * Netgraph is only permitted to join groups once
547 			 * via the if_addmulti() KPI, because it cannot hold
548 			 * struct ifmultiaddr * between calls. It may also
549 			 * lose a race while we check if the membership
550 			 * already exists.
551 			 */
552 			if_maddr_rlock(priv->ifp);
553 			ifma = if_findmulti(priv->ifp,
554 			    (struct sockaddr *)&sa_dl);
555 			if_maddr_runlock(priv->ifp);
556 			if (ifma != NULL) {
557 				error = EADDRINUSE;
558 			} else {
559 				error = if_addmulti(priv->ifp,
560 				    (struct sockaddr *)&sa_dl, &ifma);
561 			}
562 			break;
563 		    }
564 		case NGM_ETHER_DEL_MULTI:
565 		    {
566 			struct sockaddr_dl sa_dl;
567 
568 			if (msg->header.arglen != ETHER_ADDR_LEN) {
569 				error = EINVAL;
570 				break;
571 			}
572 			bzero(&sa_dl, sizeof(struct sockaddr_dl));
573 			sa_dl.sdl_len = sizeof(struct sockaddr_dl);
574 			sa_dl.sdl_family = AF_LINK;
575 			sa_dl.sdl_alen = ETHER_ADDR_LEN;
576 			bcopy((void *)msg->data, LLADDR(&sa_dl),
577 			    ETHER_ADDR_LEN);
578 			error = if_delmulti(priv->ifp,
579 			    (struct sockaddr *)&sa_dl);
580 			break;
581 		    }
582 		case NGM_ETHER_DETACH:
583 			ng_ether_detach(priv->ifp);
584 			break;
585 		default:
586 			error = EINVAL;
587 			break;
588 		}
589 		break;
590 	default:
591 		error = EINVAL;
592 		break;
593 	}
594 	NG_RESPOND_MSG(error, node, item, resp);
595 	NG_FREE_MSG(msg);
596 	return (error);
597 }
598 
599 /*
600  * Receive data on a hook.
601  * Since we use per-hook recveive methods this should never be called.
602  */
603 static int
604 ng_ether_rcvdata(hook_p hook, item_p item)
605 {
606 	NG_FREE_ITEM(item);
607 
608 	panic("%s: weird hook", __func__);
609 }
610 
611 /*
612  * Handle an mbuf received on the "lower" or "orphan" hook.
613  */
614 static int
615 ng_ether_rcv_lower(hook_p hook, item_p item)
616 {
617 	struct mbuf *m;
618 	const node_p node = NG_HOOK_NODE(hook);
619 	const priv_p priv = NG_NODE_PRIVATE(node);
620  	struct ifnet *const ifp = priv->ifp;
621 
622 	NGI_GET_M(item, m);
623 	NG_FREE_ITEM(item);
624 
625 	/* Check whether interface is ready for packets */
626 
627 	if (!((ifp->if_flags & IFF_UP) &&
628 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
629 		NG_FREE_M(m);
630 		return (ENETDOWN);
631 	}
632 
633 	/* Make sure header is fully pulled up */
634 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
635 		NG_FREE_M(m);
636 		return (EINVAL);
637 	}
638 	if (m->m_len < sizeof(struct ether_header)
639 	    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
640 		return (ENOBUFS);
641 
642 	/* Drop in the MAC address if desired */
643 	if (priv->autoSrcAddr) {
644 
645 		/* Make the mbuf writable if it's not already */
646 		if (!M_WRITABLE(m)
647 		    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
648 			return (ENOBUFS);
649 
650 		/* Overwrite source MAC address */
651 		bcopy(IF_LLADDR(ifp),
652 		    mtod(m, struct ether_header *)->ether_shost,
653 		    ETHER_ADDR_LEN);
654 	}
655 
656 	/* Send it on its way */
657 	return ether_output_frame(ifp, m);
658 }
659 
660 /*
661  * Handle an mbuf received on the "upper" hook.
662  */
663 static int
664 ng_ether_rcv_upper(hook_p hook, item_p item)
665 {
666 	struct mbuf *m;
667 	const node_p node = NG_HOOK_NODE(hook);
668 	const priv_p priv = NG_NODE_PRIVATE(node);
669 	struct ifnet *ifp = priv->ifp;
670 
671 	NGI_GET_M(item, m);
672 	NG_FREE_ITEM(item);
673 
674 	/* Check length and pull off header */
675 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
676 		NG_FREE_M(m);
677 		return (EINVAL);
678 	}
679 	if (m->m_len < sizeof(struct ether_header) &&
680 	    (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
681 		return (ENOBUFS);
682 
683 	m->m_pkthdr.rcvif = ifp;
684 
685 	/* Pass the packet to the bridge, it may come back to us */
686 	if (ifp->if_bridge) {
687 		BRIDGE_INPUT(ifp, m);
688 		if (m == NULL)
689 			return (0);
690 	}
691 
692 	/* Route packet back in */
693 	ether_demux(ifp, m);
694 	return (0);
695 }
696 
697 /*
698  * Shutdown node. This resets the node but does not remove it
699  * unless the REALLY_DIE flag is set.
700  */
701 static int
702 ng_ether_shutdown(node_p node)
703 {
704 	const priv_p priv = NG_NODE_PRIVATE(node);
705 
706 	if (node->nd_flags & NGF_REALLY_DIE) {
707 		/*
708 		 * WE came here because the ethernet card is being unloaded,
709 		 * so stop being persistant.
710 		 * Actually undo all the things we did on creation.
711 		 * Assume the ifp has already been freed.
712 		 */
713 		NG_NODE_SET_PRIVATE(node, NULL);
714 		free(priv, M_NETGRAPH);
715 		NG_NODE_UNREF(node);	/* free node itself */
716 		return (0);
717 	}
718 	if (priv->promisc) {		/* disable promiscuous mode */
719 		(void)ifpromisc(priv->ifp, 0);
720 		priv->promisc = 0;
721 	}
722 	NG_NODE_REVIVE(node);		/* Signal ng_rmnode we are persisant */
723 
724 	return (0);
725 }
726 
727 /*
728  * Hook disconnection.
729  */
730 static int
731 ng_ether_disconnect(hook_p hook)
732 {
733 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
734 
735 	if (hook == priv->upper) {
736 		priv->upper = NULL;
737 		if (priv->ifp != NULL)		/* restore h/w csum */
738 			priv->ifp->if_hwassist = priv->hwassist;
739 	} else if (hook == priv->lower)
740 		priv->lower = NULL;
741 	else if (hook == priv->orphan)
742 		priv->orphan = NULL;
743 	else
744 		panic("%s: weird hook", __func__);
745 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
746 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
747 		ng_rmnode_self(NG_HOOK_NODE(hook));	/* reset node */
748 	return (0);
749 }
750 
751 /******************************************************************
752 		    	INITIALIZATION
753 ******************************************************************/
754 
755 /*
756  * Handle loading and unloading for this node type.
757  */
758 static int
759 ng_ether_mod_event(module_t mod, int event, void *data)
760 {
761 	int error = 0;
762 	int s;
763 
764 	s = splnet();
765 	switch (event) {
766 	case MOD_LOAD:
767 
768 		/* Register function hooks */
769 		if (ng_ether_attach_p != NULL) {
770 			error = EEXIST;
771 			break;
772 		}
773 		ng_ether_attach_p = ng_ether_attach;
774 		ng_ether_detach_p = ng_ether_detach;
775 		ng_ether_output_p = ng_ether_output;
776 		ng_ether_input_p = ng_ether_input;
777 		ng_ether_input_orphan_p = ng_ether_input_orphan;
778 		ng_ether_link_state_p = ng_ether_link_state;
779 
780 		break;
781 
782 	case MOD_UNLOAD:
783 
784 		/*
785 		 * Note that the base code won't try to unload us until
786 		 * all nodes have been removed, and that can't happen
787 		 * until all Ethernet interfaces are removed. In any
788 		 * case, we know there are no nodes left if the action
789 		 * is MOD_UNLOAD, so there's no need to detach any nodes.
790 		 */
791 
792 		/* Unregister function hooks */
793 		ng_ether_attach_p = NULL;
794 		ng_ether_detach_p = NULL;
795 		ng_ether_output_p = NULL;
796 		ng_ether_input_p = NULL;
797 		ng_ether_input_orphan_p = NULL;
798 		ng_ether_link_state_p = NULL;
799 		break;
800 
801 	default:
802 		error = EOPNOTSUPP;
803 		break;
804 	}
805 	splx(s);
806 	return (error);
807 }
808 
809 static void
810 vnet_ng_ether_init(const void *unused)
811 {
812 	struct ifnet *ifp;
813 
814 	/* If module load was rejected, don't attach to vnets. */
815 	if (ng_ether_attach_p != ng_ether_attach)
816 		return;
817 
818 	/* Create nodes for any already-existing Ethernet interfaces. */
819 	IFNET_RLOCK();
820 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
821 		if (ifp->if_type == IFT_ETHER
822 		    || ifp->if_type == IFT_L2VLAN)
823 			ng_ether_attach(ifp);
824 	}
825 	IFNET_RUNLOCK();
826 }
827 VNET_SYSINIT(vnet_ng_ether_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
828     vnet_ng_ether_init, NULL);
829