xref: /freebsd/sys/netgraph/ng_ether.c (revision 3157ba21)
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 
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 #include <net/vnet.h>
67 
68 #include <netgraph/ng_message.h>
69 #include <netgraph/netgraph.h>
70 #include <netgraph/ng_parse.h>
71 #include <netgraph/ng_ether.h>
72 
73 #define IFP2NG(ifp)  (IFP2AC((ifp))->ac_netgraph)
74 
75 /* Per-node private data */
76 struct private {
77 	struct ifnet	*ifp;		/* associated interface */
78 	hook_p		upper;		/* upper hook connection */
79 	hook_p		lower;		/* lower hook connection */
80 	hook_p		orphan;		/* orphan hook connection */
81 	u_char		autoSrcAddr;	/* always overwrite source address */
82 	u_char		promisc;	/* promiscuous mode enabled */
83 	u_long		hwassist;	/* hardware checksum capabilities */
84 	u_int		flags;		/* flags e.g. really die */
85 };
86 typedef struct private *priv_p;
87 
88 /* Hook pointers used by if_ethersubr.c to callback to netgraph */
89 extern	void	(*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
90 extern	void	(*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
91 extern	int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
92 extern	void	(*ng_ether_attach_p)(struct ifnet *ifp);
93 extern	void	(*ng_ether_detach_p)(struct ifnet *ifp);
94 extern	void	(*ng_ether_link_state_p)(struct ifnet *ifp, int state);
95 
96 /* Functional hooks called from if_ethersubr.c */
97 static void	ng_ether_input(struct ifnet *ifp, struct mbuf **mp);
98 static void	ng_ether_input_orphan(struct ifnet *ifp, struct mbuf *m);
99 static int	ng_ether_output(struct ifnet *ifp, struct mbuf **mp);
100 static void	ng_ether_attach(struct ifnet *ifp);
101 static void	ng_ether_detach(struct ifnet *ifp);
102 static void	ng_ether_link_state(struct ifnet *ifp, int state);
103 
104 /* Other functions */
105 static int	ng_ether_rcv_lower(hook_p node, item_p item);
106 static int	ng_ether_rcv_upper(hook_p node, item_p item);
107 
108 /* Netgraph node methods */
109 static ng_constructor_t	ng_ether_constructor;
110 static ng_rcvmsg_t	ng_ether_rcvmsg;
111 static ng_shutdown_t	ng_ether_shutdown;
112 static ng_newhook_t	ng_ether_newhook;
113 static ng_rcvdata_t	ng_ether_rcvdata;
114 static ng_disconnect_t	ng_ether_disconnect;
115 static int		ng_ether_mod_event(module_t mod, int event, void *data);
116 
117 /* List of commands and how to convert arguments to/from ASCII */
118 static const struct ng_cmdlist ng_ether_cmdlist[] = {
119 	{
120 	  NGM_ETHER_COOKIE,
121 	  NGM_ETHER_GET_IFNAME,
122 	  "getifname",
123 	  NULL,
124 	  &ng_parse_string_type
125 	},
126 	{
127 	  NGM_ETHER_COOKIE,
128 	  NGM_ETHER_GET_IFINDEX,
129 	  "getifindex",
130 	  NULL,
131 	  &ng_parse_int32_type
132 	},
133 	{
134 	  NGM_ETHER_COOKIE,
135 	  NGM_ETHER_GET_ENADDR,
136 	  "getenaddr",
137 	  NULL,
138 	  &ng_parse_enaddr_type
139 	},
140 	{
141 	  NGM_ETHER_COOKIE,
142 	  NGM_ETHER_SET_ENADDR,
143 	  "setenaddr",
144 	  &ng_parse_enaddr_type,
145 	  NULL
146 	},
147 	{
148 	  NGM_ETHER_COOKIE,
149 	  NGM_ETHER_GET_PROMISC,
150 	  "getpromisc",
151 	  NULL,
152 	  &ng_parse_int32_type
153 	},
154 	{
155 	  NGM_ETHER_COOKIE,
156 	  NGM_ETHER_SET_PROMISC,
157 	  "setpromisc",
158 	  &ng_parse_int32_type,
159 	  NULL
160 	},
161 	{
162 	  NGM_ETHER_COOKIE,
163 	  NGM_ETHER_GET_AUTOSRC,
164 	  "getautosrc",
165 	  NULL,
166 	  &ng_parse_int32_type
167 	},
168 	{
169 	  NGM_ETHER_COOKIE,
170 	  NGM_ETHER_SET_AUTOSRC,
171 	  "setautosrc",
172 	  &ng_parse_int32_type,
173 	  NULL
174 	},
175 	{
176 	  NGM_ETHER_COOKIE,
177 	  NGM_ETHER_ADD_MULTI,
178 	  "addmulti",
179 	  &ng_parse_enaddr_type,
180 	  NULL
181 	},
182 	{
183 	  NGM_ETHER_COOKIE,
184 	  NGM_ETHER_DEL_MULTI,
185 	  "delmulti",
186 	  &ng_parse_enaddr_type,
187 	  NULL
188 	},
189 	{
190 	  NGM_ETHER_COOKIE,
191 	  NGM_ETHER_DETACH,
192 	  "detach",
193 	  NULL,
194 	  NULL
195 	},
196 	{ 0 }
197 };
198 
199 static struct ng_type ng_ether_typestruct = {
200 	.version =	NG_ABI_VERSION,
201 	.name =		NG_ETHER_NODE_TYPE,
202 	.mod_event =	ng_ether_mod_event,
203 	.constructor =	ng_ether_constructor,
204 	.rcvmsg =	ng_ether_rcvmsg,
205 	.shutdown =	ng_ether_shutdown,
206 	.newhook =	ng_ether_newhook,
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_OUTBOUND_THREAD_REF();
274 	NG_SEND_DATA_ONLY(error, priv->upper, *mp);
275 	NG_OUTBOUND_THREAD_UNREF();
276 	return (error);
277 }
278 
279 /*
280  * A new Ethernet interface has been attached.
281  * Create a new node for it, etc.
282  */
283 static void
284 ng_ether_attach(struct ifnet *ifp)
285 {
286 	priv_p priv;
287 	node_p node;
288 
289 	/*
290 	 * Do not create / attach an ether node to this ifnet if
291 	 * a netgraph node with the same name already exists.
292 	 * This should prevent ether nodes to become attached to
293 	 * eiface nodes, which may be problematic due to naming
294 	 * clashes.
295 	 */
296 	if ((node = ng_name2noderef(NULL, ifp->if_xname)) != NULL) {
297 		NG_NODE_UNREF(node);
298 		return;
299 	}
300 
301 	/* Create node */
302 	KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
303 	if (ng_make_node_common(&ng_ether_typestruct, &node) != 0) {
304 		log(LOG_ERR, "%s: can't %s for %s\n",
305 		    __func__, "create node", ifp->if_xname);
306 		return;
307 	}
308 
309 	/* Allocate private data */
310 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
311 	if (priv == NULL) {
312 		log(LOG_ERR, "%s: can't %s for %s\n",
313 		    __func__, "allocate memory", ifp->if_xname);
314 		NG_NODE_UNREF(node);
315 		return;
316 	}
317 	NG_NODE_SET_PRIVATE(node, priv);
318 	priv->ifp = ifp;
319 	IFP2NG(ifp) = node;
320 	priv->hwassist = ifp->if_hwassist;
321 
322 	/* Try to give the node the same name as the interface */
323 	if (ng_name_node(node, ifp->if_xname) != 0) {
324 		log(LOG_WARNING, "%s: can't name node %s\n",
325 		    __func__, ifp->if_xname);
326 	}
327 }
328 
329 /*
330  * An Ethernet interface is being detached.
331  * REALLY Destroy its node.
332  */
333 static void
334 ng_ether_detach(struct ifnet *ifp)
335 {
336 	const node_p node = IFP2NG(ifp);
337 	const priv_p priv = NG_NODE_PRIVATE(node);
338 
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 #ifdef RESTARTABLE_PANICS /* so we don't get an error msg in LINT */
606 	return (0);
607 #endif
608 }
609 
610 /*
611  * Handle an mbuf received on the "lower" or "orphan" hook.
612  */
613 static int
614 ng_ether_rcv_lower(hook_p hook, item_p item)
615 {
616 	struct mbuf *m;
617 	const node_p node = NG_HOOK_NODE(hook);
618 	const priv_p priv = NG_NODE_PRIVATE(node);
619  	struct ifnet *const ifp = priv->ifp;
620 
621 	NGI_GET_M(item, m);
622 	NG_FREE_ITEM(item);
623 
624 	/* Check whether interface is ready for packets */
625 
626 	if (!((ifp->if_flags & IFF_UP) &&
627 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
628 		NG_FREE_M(m);
629 		return (ENETDOWN);
630 	}
631 
632 	/* Make sure header is fully pulled up */
633 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
634 		NG_FREE_M(m);
635 		return (EINVAL);
636 	}
637 	if (m->m_len < sizeof(struct ether_header)
638 	    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
639 		return (ENOBUFS);
640 
641 	/* Drop in the MAC address if desired */
642 	if (priv->autoSrcAddr) {
643 
644 		/* Make the mbuf writable if it's not already */
645 		if (!M_WRITABLE(m)
646 		    && (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
647 			return (ENOBUFS);
648 
649 		/* Overwrite source MAC address */
650 		bcopy(IF_LLADDR(ifp),
651 		    mtod(m, struct ether_header *)->ether_shost,
652 		    ETHER_ADDR_LEN);
653 	}
654 
655 	/* Send it on its way */
656 	return ether_output_frame(ifp, m);
657 }
658 
659 /*
660  * Handle an mbuf received on the "upper" hook.
661  */
662 static int
663 ng_ether_rcv_upper(hook_p hook, item_p item)
664 {
665 	struct mbuf *m;
666 	const node_p node = NG_HOOK_NODE(hook);
667 	const priv_p priv = NG_NODE_PRIVATE(node);
668 	struct ifnet *ifp = priv->ifp;
669 
670 	NGI_GET_M(item, m);
671 	NG_FREE_ITEM(item);
672 
673 	/* Check length and pull off header */
674 	if (m->m_pkthdr.len < sizeof(struct ether_header)) {
675 		NG_FREE_M(m);
676 		return (EINVAL);
677 	}
678 	if (m->m_len < sizeof(struct ether_header) &&
679 	    (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
680 		return (ENOBUFS);
681 
682 	m->m_pkthdr.rcvif = ifp;
683 
684 	/* Pass the packet to the bridge, it may come back to us */
685 	if (ifp->if_bridge) {
686 		BRIDGE_INPUT(ifp, m);
687 		if (m == NULL)
688 			return (0);
689 	}
690 
691 	/* Route packet back in */
692 	ether_demux(ifp, m);
693 	return (0);
694 }
695 
696 /*
697  * Shutdown node. This resets the node but does not remove it
698  * unless the REALLY_DIE flag is set.
699  */
700 static int
701 ng_ether_shutdown(node_p node)
702 {
703 	const priv_p priv = NG_NODE_PRIVATE(node);
704 
705 	if (node->nd_flags & NGF_REALLY_DIE) {
706 		/*
707 		 * WE came here because the ethernet card is being unloaded,
708 		 * so stop being persistant.
709 		 * Actually undo all the things we did on creation.
710 		 * Assume the ifp has already been freed.
711 		 */
712 		NG_NODE_SET_PRIVATE(node, NULL);
713 		free(priv, M_NETGRAPH);
714 		NG_NODE_UNREF(node);	/* free node itself */
715 		return (0);
716 	}
717 	if (priv->promisc) {		/* disable promiscuous mode */
718 		(void)ifpromisc(priv->ifp, 0);
719 		priv->promisc = 0;
720 	}
721 	priv->autoSrcAddr = 1;		/* reset auto-src-addr flag */
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