xref: /freebsd/sys/netgraph/ng_iface.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*
2  * ng_iface.c
3  */
4 
5 /*-
6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
7  * All rights reserved.
8  *
9  * Subject to the following obligations and disclaimer of warranty, use and
10  * redistribution of this software, in source or object code forms, with or
11  * without modifications are expressly permitted by Whistle Communications;
12  * provided, however, that:
13  * 1. Any and all reproductions of the source or object code must include the
14  *    copyright notice above and the following disclaimer of warranties; and
15  * 2. No rights are granted, in any manner or form, to use Whistle
16  *    Communications, Inc. trademarks, including the mark "WHISTLE
17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18  *    such appears in the above copyright notice or in the software.
19  *
20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36  * OF SUCH DAMAGE.
37  *
38  * Author: Archie Cobbs <archie@freebsd.org>
39  *
40  * $FreeBSD$
41  * $Whistle: ng_iface.c,v 1.33 1999/11/01 09:24:51 julian Exp $
42  */
43 
44 /*
45  * This node is also a system networking interface. It has
46  * a hook for each protocol (IP, AppleTalk, etc). Packets
47  * are simply relayed between the interface and the hooks.
48  *
49  * Interfaces are named ng0, ng1, etc.  New nodes take the
50  * first available interface name.
51  *
52  * This node also includes Berkeley packet filter support.
53  */
54 
55 #include "opt_inet.h"
56 #include "opt_inet6.h"
57 
58 #include <sys/param.h>
59 #include <sys/systm.h>
60 #include <sys/errno.h>
61 #include <sys/kernel.h>
62 #include <sys/malloc.h>
63 #include <sys/mbuf.h>
64 #include <sys/errno.h>
65 #include <sys/proc.h>
66 #include <sys/random.h>
67 #include <sys/sockio.h>
68 #include <sys/socket.h>
69 #include <sys/syslog.h>
70 #include <sys/libkern.h>
71 
72 #include <net/if.h>
73 #include <net/if_var.h>
74 #include <net/if_types.h>
75 #include <net/bpf.h>
76 #include <net/netisr.h>
77 #include <net/route.h>
78 #include <net/vnet.h>
79 
80 #include <netinet/in.h>
81 
82 #include <netgraph/ng_message.h>
83 #include <netgraph/netgraph.h>
84 #include <netgraph/ng_parse.h>
85 #include <netgraph/ng_iface.h>
86 
87 #ifdef NG_SEPARATE_MALLOC
88 static MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node");
89 #else
90 #define M_NETGRAPH_IFACE M_NETGRAPH
91 #endif
92 
93 /* This struct describes one address family */
94 struct iffam {
95 	sa_family_t	family;		/* Address family */
96 	const char	*hookname;	/* Name for hook */
97 };
98 typedef const struct iffam *iffam_p;
99 
100 /* List of address families supported by our interface */
101 const static struct iffam gFamilies[] = {
102 	{ AF_INET,	NG_IFACE_HOOK_INET	},
103 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
104 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
105 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
106 };
107 #define	NUM_FAMILIES		nitems(gFamilies)
108 
109 /* Node private data */
110 struct ng_iface_private {
111 	struct	ifnet *ifp;		/* Our interface */
112 	int	unit;			/* Interface unit number */
113 	node_p	node;			/* Our netgraph node */
114 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
115 };
116 typedef struct ng_iface_private *priv_p;
117 
118 /* Interface methods */
119 static void	ng_iface_start(struct ifnet *ifp);
120 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
121 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
122     			const struct sockaddr *dst, struct route *ro);
123 static void	ng_iface_bpftap(struct ifnet *ifp,
124 			struct mbuf *m, sa_family_t family);
125 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
126 			sa_family_t sa);
127 #ifdef DEBUG
128 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
129 #endif
130 
131 /* Netgraph methods */
132 static int		ng_iface_mod_event(module_t, int, void *);
133 static ng_constructor_t	ng_iface_constructor;
134 static ng_rcvmsg_t	ng_iface_rcvmsg;
135 static ng_shutdown_t	ng_iface_shutdown;
136 static ng_newhook_t	ng_iface_newhook;
137 static ng_rcvdata_t	ng_iface_rcvdata;
138 static ng_disconnect_t	ng_iface_disconnect;
139 
140 /* Helper stuff */
141 static iffam_p	get_iffam_from_af(sa_family_t family);
142 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
143 static iffam_p	get_iffam_from_name(const char *name);
144 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
145 
146 /* List of commands and how to convert arguments to/from ASCII */
147 static const struct ng_cmdlist ng_iface_cmds[] = {
148 	{
149 	  NGM_IFACE_COOKIE,
150 	  NGM_IFACE_GET_IFNAME,
151 	  "getifname",
152 	  NULL,
153 	  &ng_parse_string_type
154 	},
155 	{
156 	  NGM_IFACE_COOKIE,
157 	  NGM_IFACE_POINT2POINT,
158 	  "point2point",
159 	  NULL,
160 	  NULL
161 	},
162 	{
163 	  NGM_IFACE_COOKIE,
164 	  NGM_IFACE_BROADCAST,
165 	  "broadcast",
166 	  NULL,
167 	  NULL
168 	},
169 	{
170 	  NGM_IFACE_COOKIE,
171 	  NGM_IFACE_GET_IFINDEX,
172 	  "getifindex",
173 	  NULL,
174 	  &ng_parse_uint32_type
175 	},
176 	{ 0 }
177 };
178 
179 /* Node type descriptor */
180 static struct ng_type typestruct = {
181 	.version =	NG_ABI_VERSION,
182 	.name =		NG_IFACE_NODE_TYPE,
183 	.mod_event =	ng_iface_mod_event,
184 	.constructor =	ng_iface_constructor,
185 	.rcvmsg =	ng_iface_rcvmsg,
186 	.shutdown =	ng_iface_shutdown,
187 	.newhook =	ng_iface_newhook,
188 	.rcvdata =	ng_iface_rcvdata,
189 	.disconnect =	ng_iface_disconnect,
190 	.cmdlist =	ng_iface_cmds,
191 };
192 NETGRAPH_INIT(iface, &typestruct);
193 
194 static VNET_DEFINE(struct unrhdr *, ng_iface_unit);
195 #define	V_ng_iface_unit			VNET(ng_iface_unit)
196 
197 /************************************************************************
198 			HELPER STUFF
199  ************************************************************************/
200 
201 /*
202  * Get the family descriptor from the family ID
203  */
204 static __inline iffam_p
205 get_iffam_from_af(sa_family_t family)
206 {
207 	iffam_p iffam;
208 	int k;
209 
210 	for (k = 0; k < NUM_FAMILIES; k++) {
211 		iffam = &gFamilies[k];
212 		if (iffam->family == family)
213 			return (iffam);
214 	}
215 	return (NULL);
216 }
217 
218 /*
219  * Get the family descriptor from the hook
220  */
221 static __inline iffam_p
222 get_iffam_from_hook(priv_p priv, hook_p hook)
223 {
224 	int k;
225 
226 	for (k = 0; k < NUM_FAMILIES; k++)
227 		if (priv->hooks[k] == hook)
228 			return (&gFamilies[k]);
229 	return (NULL);
230 }
231 
232 /*
233  * Get the hook from the iffam descriptor
234  */
235 
236 static __inline hook_p *
237 get_hook_from_iffam(priv_p priv, iffam_p iffam)
238 {
239 	return (&priv->hooks[iffam - gFamilies]);
240 }
241 
242 /*
243  * Get the iffam descriptor from the name
244  */
245 static __inline iffam_p
246 get_iffam_from_name(const char *name)
247 {
248 	iffam_p iffam;
249 	int k;
250 
251 	for (k = 0; k < NUM_FAMILIES; k++) {
252 		iffam = &gFamilies[k];
253 		if (!strcmp(iffam->hookname, name))
254 			return (iffam);
255 	}
256 	return (NULL);
257 }
258 
259 /************************************************************************
260 			INTERFACE STUFF
261  ************************************************************************/
262 
263 /*
264  * Process an ioctl for the virtual interface
265  */
266 static int
267 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
268 {
269 	struct ifreq *const ifr = (struct ifreq *) data;
270 	int error = 0;
271 
272 #ifdef DEBUG
273 	ng_iface_print_ioctl(ifp, command, data);
274 #endif
275 	switch (command) {
276 
277 	/* These two are mostly handled at a higher layer */
278 	case SIOCSIFADDR:
279 		ifp->if_flags |= IFF_UP;
280 		ifp->if_drv_flags |= IFF_DRV_RUNNING;
281 		ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
282 		break;
283 	case SIOCGIFADDR:
284 		break;
285 
286 	/* Set flags */
287 	case SIOCSIFFLAGS:
288 		/*
289 		 * If the interface is marked up and stopped, then start it.
290 		 * If it is marked down and running, then stop it.
291 		 */
292 		if (ifr->ifr_flags & IFF_UP) {
293 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
294 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
295 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
296 			}
297 		} else {
298 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
299 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
300 				    IFF_DRV_OACTIVE);
301 		}
302 		break;
303 
304 	/* Set the interface MTU */
305 	case SIOCSIFMTU:
306 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
307 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
308 			error = EINVAL;
309 		else
310 			ifp->if_mtu = ifr->ifr_mtu;
311 		break;
312 
313 	/* Stuff that's not supported */
314 	case SIOCADDMULTI:
315 	case SIOCDELMULTI:
316 		error = 0;
317 		break;
318 	case SIOCSIFPHYS:
319 		error = EOPNOTSUPP;
320 		break;
321 
322 	default:
323 		error = EINVAL;
324 		break;
325 	}
326 	return (error);
327 }
328 
329 /*
330  * This routine is called to deliver a packet out the interface.
331  * We simply look at the address family and relay the packet to
332  * the corresponding hook, if it exists and is connected.
333  */
334 
335 static int
336 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
337 	const struct sockaddr *dst, struct route *ro)
338 {
339 	struct m_tag *mtag;
340 	uint32_t af;
341 	int error;
342 
343 	/* Check interface flags */
344 	if (!((ifp->if_flags & IFF_UP) &&
345 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
346 		m_freem(m);
347 		return (ENETDOWN);
348 	}
349 
350 	/* Protect from deadly infinite recursion. */
351 	mtag = NULL;
352 	while ((mtag = m_tag_locate(m, MTAG_NGIF, MTAG_NGIF_CALLED, mtag))) {
353 		if (*(struct ifnet **)(mtag + 1) == ifp) {
354 			log(LOG_NOTICE, "Loop detected on %s\n", ifp->if_xname);
355 			m_freem(m);
356 			return (EDEADLK);
357 		}
358 	}
359 	mtag = m_tag_alloc(MTAG_NGIF, MTAG_NGIF_CALLED, sizeof(struct ifnet *),
360 	    M_NOWAIT);
361 	if (mtag == NULL) {
362 		m_freem(m);
363 		return (ENOMEM);
364 	}
365 	*(struct ifnet **)(mtag + 1) = ifp;
366 	m_tag_prepend(m, mtag);
367 
368 	/* BPF writes need to be handled specially. */
369 	if (dst->sa_family == AF_UNSPEC)
370 		bcopy(dst->sa_data, &af, sizeof(af));
371 	else
372 		af = dst->sa_family;
373 
374 	/* Berkeley packet filter */
375 	ng_iface_bpftap(ifp, m, af);
376 
377 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
378 		M_PREPEND(m, sizeof(sa_family_t), M_NOWAIT);
379 		if (m == NULL) {
380 			if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
381 			return (ENOBUFS);
382 		}
383 		*(sa_family_t *)m->m_data = af;
384 		error = (ifp->if_transmit)(ifp, m);
385 	} else
386 		error = ng_iface_send(ifp, m, af);
387 
388 	return (error);
389 }
390 
391 /*
392  * Start method is used only when ALTQ is enabled.
393  */
394 static void
395 ng_iface_start(struct ifnet *ifp)
396 {
397 	struct mbuf *m;
398 	sa_family_t sa;
399 
400 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
401 
402 	for(;;) {
403 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
404 		if (m == NULL)
405 			break;
406 		sa = *mtod(m, sa_family_t *);
407 		m_adj(m, sizeof(sa_family_t));
408 		ng_iface_send(ifp, m, sa);
409 	}
410 }
411 
412 /*
413  * Flash a packet by the BPF (requires prepending 4 byte AF header)
414  * Note the phoney mbuf; this is OK because BPF treats it read-only.
415  */
416 static void
417 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
418 {
419 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
420 	if (bpf_peers_present(ifp->if_bpf)) {
421 		int32_t family4 = (int32_t)family;
422 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
423 	}
424 }
425 
426 /*
427  * This routine does actual delivery of the packet into the
428  * netgraph(4). It is called from ng_iface_start() and
429  * ng_iface_output().
430  */
431 static int
432 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
433 {
434 	const priv_p priv = (priv_p) ifp->if_softc;
435 	const iffam_p iffam = get_iffam_from_af(sa);
436 	int error;
437 	int len;
438 
439 	/* Check address family to determine hook (if known) */
440 	if (iffam == NULL) {
441 		m_freem(m);
442 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
443 		return (EAFNOSUPPORT);
444 	}
445 
446 	/* Copy length before the mbuf gets invalidated. */
447 	len = m->m_pkthdr.len;
448 
449 	/* Send packet. If hook is not connected, mbuf will get freed. */
450 	NG_OUTBOUND_THREAD_REF();
451 	NG_SEND_DATA_ONLY(error, *get_hook_from_iffam(priv, iffam), m);
452 	NG_OUTBOUND_THREAD_UNREF();
453 
454 	/* Update stats. */
455 	if (error == 0) {
456 		if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
457 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
458 	}
459 
460 	return (error);
461 }
462 
463 #ifdef DEBUG
464 /*
465  * Display an ioctl to the virtual interface
466  */
467 
468 static void
469 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
470 {
471 	char   *str;
472 
473 	switch (command & IOC_DIRMASK) {
474 	case IOC_VOID:
475 		str = "IO";
476 		break;
477 	case IOC_OUT:
478 		str = "IOR";
479 		break;
480 	case IOC_IN:
481 		str = "IOW";
482 		break;
483 	case IOC_INOUT:
484 		str = "IORW";
485 		break;
486 	default:
487 		str = "IO??";
488 	}
489 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
490 	       ifp->if_xname,
491 	       str,
492 	       IOCGROUP(command),
493 	       command & 0xff,
494 	       IOCPARM_LEN(command));
495 }
496 #endif /* DEBUG */
497 
498 /************************************************************************
499 			NETGRAPH NODE STUFF
500  ************************************************************************/
501 
502 /*
503  * Constructor for a node
504  */
505 static int
506 ng_iface_constructor(node_p node)
507 {
508 	struct ifnet *ifp;
509 	priv_p priv;
510 
511 	/* Allocate node and interface private structures */
512 	priv = malloc(sizeof(*priv), M_NETGRAPH_IFACE, M_WAITOK | M_ZERO);
513 	ifp = if_alloc(IFT_PROPVIRTUAL);
514 	if (ifp == NULL) {
515 		free(priv, M_NETGRAPH_IFACE);
516 		return (ENOMEM);
517 	}
518 
519 	/* Link them together */
520 	ifp->if_softc = priv;
521 	priv->ifp = ifp;
522 
523 	/* Get an interface unit number */
524 	priv->unit = alloc_unr(V_ng_iface_unit);
525 
526 	/* Link together node and private info */
527 	NG_NODE_SET_PRIVATE(node, priv);
528 	priv->node = node;
529 
530 	/* Initialize interface structure */
531 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
532 	ifp->if_output = ng_iface_output;
533 	ifp->if_start = ng_iface_start;
534 	ifp->if_ioctl = ng_iface_ioctl;
535 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
536 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
537 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
538 	ifp->if_addrlen = 0;			/* XXX */
539 	ifp->if_hdrlen = 0;			/* XXX */
540 	ifp->if_baudrate = 64000;		/* XXX */
541 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
542 	ifp->if_snd.ifq_drv_maxlen = ifqmaxlen;
543 	IFQ_SET_READY(&ifp->if_snd);
544 
545 	/* Give this node the same name as the interface (if possible) */
546 	if (ng_name_node(node, ifp->if_xname) != 0)
547 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
548 		    ifp->if_xname);
549 
550 	/* Attach the interface */
551 	if_attach(ifp);
552 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
553 
554 	/* Done */
555 	return (0);
556 }
557 
558 /*
559  * Give our ok for a hook to be added
560  */
561 static int
562 ng_iface_newhook(node_p node, hook_p hook, const char *name)
563 {
564 	const iffam_p iffam = get_iffam_from_name(name);
565 	hook_p *hookptr;
566 
567 	if (iffam == NULL)
568 		return (EPFNOSUPPORT);
569 	hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
570 	if (*hookptr != NULL)
571 		return (EISCONN);
572 	*hookptr = hook;
573 	NG_HOOK_HI_STACK(hook);
574 	NG_HOOK_SET_TO_INBOUND(hook);
575 	return (0);
576 }
577 
578 /*
579  * Receive a control message
580  */
581 static int
582 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
583 {
584 	const priv_p priv = NG_NODE_PRIVATE(node);
585 	struct ifnet *const ifp = priv->ifp;
586 	struct ng_mesg *resp = NULL;
587 	int error = 0;
588 	struct ng_mesg *msg;
589 
590 	NGI_GET_MSG(item, msg);
591 	switch (msg->header.typecookie) {
592 	case NGM_IFACE_COOKIE:
593 		switch (msg->header.cmd) {
594 		case NGM_IFACE_GET_IFNAME:
595 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
596 			if (resp == NULL) {
597 				error = ENOMEM;
598 				break;
599 			}
600 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
601 			break;
602 
603 		case NGM_IFACE_POINT2POINT:
604 		case NGM_IFACE_BROADCAST:
605 		    {
606 
607 			/* Deny request if interface is UP */
608 			if ((ifp->if_flags & IFF_UP) != 0)
609 				return (EBUSY);
610 
611 			/* Change flags */
612 			switch (msg->header.cmd) {
613 			case NGM_IFACE_POINT2POINT:
614 				ifp->if_flags |= IFF_POINTOPOINT;
615 				ifp->if_flags &= ~IFF_BROADCAST;
616 				break;
617 			case NGM_IFACE_BROADCAST:
618 				ifp->if_flags &= ~IFF_POINTOPOINT;
619 				ifp->if_flags |= IFF_BROADCAST;
620 				break;
621 			}
622 			break;
623 		    }
624 
625 		case NGM_IFACE_GET_IFINDEX:
626 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
627 			if (resp == NULL) {
628 				error = ENOMEM;
629 				break;
630 			}
631 			*((uint32_t *)resp->data) = priv->ifp->if_index;
632 			break;
633 
634 		default:
635 			error = EINVAL;
636 			break;
637 		}
638 		break;
639 	case NGM_FLOW_COOKIE:
640 		switch (msg->header.cmd) {
641 		case NGM_LINK_IS_UP:
642 			if_link_state_change(ifp, LINK_STATE_UP);
643 			break;
644 		case NGM_LINK_IS_DOWN:
645 			if_link_state_change(ifp, LINK_STATE_DOWN);
646 			break;
647 		default:
648 			break;
649 		}
650 		break;
651 	default:
652 		error = EINVAL;
653 		break;
654 	}
655 	NG_RESPOND_MSG(error, node, item, resp);
656 	NG_FREE_MSG(msg);
657 	return (error);
658 }
659 
660 /*
661  * Recive data from a hook. Pass the packet to the correct input routine.
662  */
663 static int
664 ng_iface_rcvdata(hook_p hook, item_p item)
665 {
666 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
667 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
668 	struct ifnet *const ifp = priv->ifp;
669 	struct mbuf *m;
670 	int isr;
671 
672 	NGI_GET_M(item, m);
673 	NG_FREE_ITEM(item);
674 	/* Sanity checks */
675 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
676 	M_ASSERTPKTHDR(m);
677 	if ((ifp->if_flags & IFF_UP) == 0) {
678 		NG_FREE_M(m);
679 		return (ENETDOWN);
680 	}
681 
682 	/* Update interface stats */
683 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
684 	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
685 
686 	/* Note receiving interface */
687 	m->m_pkthdr.rcvif = ifp;
688 
689 	/* Berkeley packet filter */
690 	ng_iface_bpftap(ifp, m, iffam->family);
691 
692 	/* Send packet */
693 	switch (iffam->family) {
694 #ifdef INET
695 	case AF_INET:
696 		isr = NETISR_IP;
697 		break;
698 #endif
699 #ifdef INET6
700 	case AF_INET6:
701 		isr = NETISR_IPV6;
702 		break;
703 #endif
704 	default:
705 		m_freem(m);
706 		return (EAFNOSUPPORT);
707 	}
708 	random_harvest_queue(m, sizeof(*m), 2, RANDOM_NET_NG);
709 	M_SETFIB(m, ifp->if_fib);
710 	netisr_dispatch(isr, m);
711 	return (0);
712 }
713 
714 /*
715  * Shutdown and remove the node and its associated interface.
716  */
717 static int
718 ng_iface_shutdown(node_p node)
719 {
720 	const priv_p priv = NG_NODE_PRIVATE(node);
721 
722 	/*
723 	 * The ifnet may be in a different vnet than the netgraph node,
724 	 * hence we have to change the current vnet context here.
725 	 */
726 	CURVNET_SET_QUIET(priv->ifp->if_vnet);
727 	bpfdetach(priv->ifp);
728 	if_detach(priv->ifp);
729 	if_free(priv->ifp);
730 	CURVNET_RESTORE();
731 	priv->ifp = NULL;
732 	free_unr(V_ng_iface_unit, priv->unit);
733 	free(priv, M_NETGRAPH_IFACE);
734 	NG_NODE_SET_PRIVATE(node, NULL);
735 	NG_NODE_UNREF(node);
736 	return (0);
737 }
738 
739 /*
740  * Hook disconnection. Note that we do *not* shutdown when all
741  * hooks have been disconnected.
742  */
743 static int
744 ng_iface_disconnect(hook_p hook)
745 {
746 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
747 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
748 
749 	if (iffam == NULL)
750 		panic("%s", __func__);
751 	*get_hook_from_iffam(priv, iffam) = NULL;
752 	return (0);
753 }
754 
755 /*
756  * Handle loading and unloading for this node type.
757  */
758 static int
759 ng_iface_mod_event(module_t mod, int event, void *data)
760 {
761 	int error = 0;
762 
763 	switch (event) {
764 	case MOD_LOAD:
765 	case MOD_UNLOAD:
766 		break;
767 	default:
768 		error = EOPNOTSUPP;
769 		break;
770 	}
771 	return (error);
772 }
773 
774 static void
775 vnet_ng_iface_init(const void *unused)
776 {
777 
778 	V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
779 }
780 VNET_SYSINIT(vnet_ng_iface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
781     vnet_ng_iface_init, NULL);
782 
783 static void
784 vnet_ng_iface_uninit(const void *unused)
785 {
786 
787 	delete_unrhdr(V_ng_iface_unit);
788 }
789 VNET_SYSUNINIT(vnet_ng_iface_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
790     vnet_ng_iface_uninit, NULL);
791