xref: /freebsd/sys/netgraph/ng_iface.c (revision 62cfcf62f627e5093fb37026a6d8c98e4d2ef04c)
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/lock.h>
63 #include <sys/malloc.h>
64 #include <sys/mbuf.h>
65 #include <sys/errno.h>
66 #include <sys/proc.h>
67 #include <sys/random.h>
68 #include <sys/rmlock.h>
69 #include <sys/sockio.h>
70 #include <sys/socket.h>
71 #include <sys/sysctl.h>
72 #include <sys/syslog.h>
73 #include <sys/libkern.h>
74 
75 #include <net/if.h>
76 #include <net/if_var.h>
77 #include <net/if_types.h>
78 #include <net/bpf.h>
79 #include <net/netisr.h>
80 #include <net/route.h>
81 #include <net/vnet.h>
82 
83 #include <netinet/in.h>
84 
85 #include <netgraph/ng_message.h>
86 #include <netgraph/netgraph.h>
87 #include <netgraph/ng_parse.h>
88 #include <netgraph/ng_iface.h>
89 
90 #ifdef NG_SEPARATE_MALLOC
91 static MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node");
92 #else
93 #define M_NETGRAPH_IFACE M_NETGRAPH
94 #endif
95 
96 static SYSCTL_NODE(_net_graph, OID_AUTO, iface, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
97     "Point to point netgraph interface");
98 VNET_DEFINE_STATIC(int, ng_iface_max_nest) = 2;
99 #define	V_ng_iface_max_nest	VNET(ng_iface_max_nest)
100 SYSCTL_INT(_net_graph_iface, OID_AUTO, max_nesting, CTLFLAG_VNET | CTLFLAG_RW,
101     &VNET_NAME(ng_iface_max_nest), 0, "Max nested tunnels");
102 
103 /* This struct describes one address family */
104 struct iffam {
105 	sa_family_t	family;		/* Address family */
106 	const char	*hookname;	/* Name for hook */
107 };
108 typedef const struct iffam *iffam_p;
109 
110 /* List of address families supported by our interface */
111 const static struct iffam gFamilies[] = {
112 	{ AF_INET,	NG_IFACE_HOOK_INET	},
113 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
114 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
115 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
116 };
117 #define	NUM_FAMILIES		nitems(gFamilies)
118 
119 /* Node private data */
120 struct ng_iface_private {
121 	struct	ifnet *ifp;		/* Our interface */
122 	int	unit;			/* Interface unit number */
123 	node_p	node;			/* Our netgraph node */
124 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
125 	struct rmlock	lock;		/* Protect private data changes */
126 };
127 typedef struct ng_iface_private *priv_p;
128 
129 #define	PRIV_RLOCK(priv, t)	rm_rlock(&priv->lock, t)
130 #define	PRIV_RUNLOCK(priv, t)	rm_runlock(&priv->lock, t)
131 #define	PRIV_WLOCK(priv)	rm_wlock(&priv->lock)
132 #define	PRIV_WUNLOCK(priv)	rm_wunlock(&priv->lock)
133 
134 /* Interface methods */
135 static void	ng_iface_start(struct ifnet *ifp);
136 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
137 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
138     			const struct sockaddr *dst, struct route *ro);
139 static void	ng_iface_bpftap(struct ifnet *ifp,
140 			struct mbuf *m, sa_family_t family);
141 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
142 			sa_family_t sa);
143 #ifdef DEBUG
144 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
145 #endif
146 
147 /* Netgraph methods */
148 static int		ng_iface_mod_event(module_t, int, void *);
149 static ng_constructor_t	ng_iface_constructor;
150 static ng_rcvmsg_t	ng_iface_rcvmsg;
151 static ng_shutdown_t	ng_iface_shutdown;
152 static ng_newhook_t	ng_iface_newhook;
153 static ng_rcvdata_t	ng_iface_rcvdata;
154 static ng_disconnect_t	ng_iface_disconnect;
155 
156 /* Helper stuff */
157 static iffam_p	get_iffam_from_af(sa_family_t family);
158 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
159 static iffam_p	get_iffam_from_name(const char *name);
160 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
161 
162 /* List of commands and how to convert arguments to/from ASCII */
163 static const struct ng_cmdlist ng_iface_cmds[] = {
164 	{
165 	  NGM_IFACE_COOKIE,
166 	  NGM_IFACE_GET_IFNAME,
167 	  "getifname",
168 	  NULL,
169 	  &ng_parse_string_type
170 	},
171 	{
172 	  NGM_IFACE_COOKIE,
173 	  NGM_IFACE_POINT2POINT,
174 	  "point2point",
175 	  NULL,
176 	  NULL
177 	},
178 	{
179 	  NGM_IFACE_COOKIE,
180 	  NGM_IFACE_BROADCAST,
181 	  "broadcast",
182 	  NULL,
183 	  NULL
184 	},
185 	{
186 	  NGM_IFACE_COOKIE,
187 	  NGM_IFACE_GET_IFINDEX,
188 	  "getifindex",
189 	  NULL,
190 	  &ng_parse_uint32_type
191 	},
192 	{ 0 }
193 };
194 
195 /* Node type descriptor */
196 static struct ng_type typestruct = {
197 	.version =	NG_ABI_VERSION,
198 	.name =		NG_IFACE_NODE_TYPE,
199 	.mod_event =	ng_iface_mod_event,
200 	.constructor =	ng_iface_constructor,
201 	.rcvmsg =	ng_iface_rcvmsg,
202 	.shutdown =	ng_iface_shutdown,
203 	.newhook =	ng_iface_newhook,
204 	.rcvdata =	ng_iface_rcvdata,
205 	.disconnect =	ng_iface_disconnect,
206 	.cmdlist =	ng_iface_cmds,
207 };
208 NETGRAPH_INIT(iface, &typestruct);
209 
210 VNET_DEFINE_STATIC(struct unrhdr *, ng_iface_unit);
211 #define	V_ng_iface_unit			VNET(ng_iface_unit)
212 
213 /************************************************************************
214 			HELPER STUFF
215  ************************************************************************/
216 
217 /*
218  * Get the family descriptor from the family ID
219  */
220 static __inline iffam_p
221 get_iffam_from_af(sa_family_t family)
222 {
223 	iffam_p iffam;
224 	int k;
225 
226 	for (k = 0; k < NUM_FAMILIES; k++) {
227 		iffam = &gFamilies[k];
228 		if (iffam->family == family)
229 			return (iffam);
230 	}
231 	return (NULL);
232 }
233 
234 /*
235  * Get the family descriptor from the hook
236  */
237 static __inline iffam_p
238 get_iffam_from_hook(priv_p priv, hook_p hook)
239 {
240 	int k;
241 
242 	for (k = 0; k < NUM_FAMILIES; k++)
243 		if (priv->hooks[k] == hook)
244 			return (&gFamilies[k]);
245 	return (NULL);
246 }
247 
248 /*
249  * Get the hook from the iffam descriptor
250  */
251 
252 static __inline hook_p *
253 get_hook_from_iffam(priv_p priv, iffam_p iffam)
254 {
255 	return (&priv->hooks[iffam - gFamilies]);
256 }
257 
258 /*
259  * Get the iffam descriptor from the name
260  */
261 static __inline iffam_p
262 get_iffam_from_name(const char *name)
263 {
264 	iffam_p iffam;
265 	int k;
266 
267 	for (k = 0; k < NUM_FAMILIES; k++) {
268 		iffam = &gFamilies[k];
269 		if (!strcmp(iffam->hookname, name))
270 			return (iffam);
271 	}
272 	return (NULL);
273 }
274 
275 /************************************************************************
276 			INTERFACE STUFF
277  ************************************************************************/
278 
279 /*
280  * Process an ioctl for the virtual interface
281  */
282 static int
283 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
284 {
285 	struct ifreq *const ifr = (struct ifreq *) data;
286 	int error = 0;
287 
288 #ifdef DEBUG
289 	ng_iface_print_ioctl(ifp, command, data);
290 #endif
291 	switch (command) {
292 
293 	/* These two are mostly handled at a higher layer */
294 	case SIOCSIFADDR:
295 		ifp->if_flags |= IFF_UP;
296 		ifp->if_drv_flags |= IFF_DRV_RUNNING;
297 		ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
298 		break;
299 	case SIOCGIFADDR:
300 		break;
301 
302 	/* Set flags */
303 	case SIOCSIFFLAGS:
304 		/*
305 		 * If the interface is marked up and stopped, then start it.
306 		 * If it is marked down and running, then stop it.
307 		 */
308 		if (ifr->ifr_flags & IFF_UP) {
309 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
310 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
311 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
312 			}
313 		} else {
314 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
315 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
316 				    IFF_DRV_OACTIVE);
317 		}
318 		break;
319 
320 	/* Set the interface MTU */
321 	case SIOCSIFMTU:
322 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
323 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
324 			error = EINVAL;
325 		else
326 			ifp->if_mtu = ifr->ifr_mtu;
327 		break;
328 
329 	/* Stuff that's not supported */
330 	case SIOCADDMULTI:
331 	case SIOCDELMULTI:
332 		error = 0;
333 		break;
334 	case SIOCSIFPHYS:
335 		error = EOPNOTSUPP;
336 		break;
337 
338 	default:
339 		error = EINVAL;
340 		break;
341 	}
342 	return (error);
343 }
344 
345 /*
346  * This routine is called to deliver a packet out the interface.
347  * We simply look at the address family and relay the packet to
348  * the corresponding hook, if it exists and is connected.
349  */
350 
351 static int
352 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
353 	const struct sockaddr *dst, struct route *ro)
354 {
355 	uint32_t af;
356 	int error;
357 
358 	/* Check interface flags */
359 	if (!((ifp->if_flags & IFF_UP) &&
360 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
361 		m_freem(m);
362 		return (ENETDOWN);
363 	}
364 
365 	/* Protect from deadly infinite recursion. */
366 	error = if_tunnel_check_nesting(ifp, m, NGM_IFACE_COOKIE,
367 	    V_ng_iface_max_nest);
368 	if (error) {
369 		m_freem(m);
370 		return (error);
371 	}
372 
373 	/* BPF writes need to be handled specially. */
374 	if (dst->sa_family == AF_UNSPEC)
375 		bcopy(dst->sa_data, &af, sizeof(af));
376 	else
377 		af = dst->sa_family;
378 
379 	/* Berkeley packet filter */
380 	ng_iface_bpftap(ifp, m, af);
381 
382 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
383 		M_PREPEND(m, sizeof(sa_family_t), M_NOWAIT);
384 		if (m == NULL) {
385 			if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
386 			return (ENOBUFS);
387 		}
388 		*(sa_family_t *)m->m_data = af;
389 		error = (ifp->if_transmit)(ifp, m);
390 	} else
391 		error = ng_iface_send(ifp, m, af);
392 
393 	return (error);
394 }
395 
396 /*
397  * Start method is used only when ALTQ is enabled.
398  */
399 static void
400 ng_iface_start(struct ifnet *ifp)
401 {
402 	struct mbuf *m;
403 	sa_family_t sa;
404 
405 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
406 
407 	for(;;) {
408 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
409 		if (m == NULL)
410 			break;
411 		sa = *mtod(m, sa_family_t *);
412 		m_adj(m, sizeof(sa_family_t));
413 		ng_iface_send(ifp, m, sa);
414 	}
415 }
416 
417 /*
418  * Flash a packet by the BPF (requires prepending 4 byte AF header)
419  * Note the phoney mbuf; this is OK because BPF treats it read-only.
420  */
421 static void
422 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
423 {
424 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
425 	if (bpf_peers_present(ifp->if_bpf)) {
426 		int32_t family4 = (int32_t)family;
427 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
428 	}
429 }
430 
431 /*
432  * This routine does actual delivery of the packet into the
433  * netgraph(4). It is called from ng_iface_start() and
434  * ng_iface_output().
435  */
436 static int
437 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
438 {
439 	struct rm_priotracker priv_tracker;
440 	const priv_p priv = (priv_p) ifp->if_softc;
441 	const iffam_p iffam = get_iffam_from_af(sa);
442 	hook_p hook;
443 	int error;
444 	int len;
445 
446 	/* Check address family to determine hook (if known) */
447 	if (iffam == NULL) {
448 		m_freem(m);
449 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
450 		return (EAFNOSUPPORT);
451 	}
452 
453 	/* Copy length before the mbuf gets invalidated. */
454 	len = m->m_pkthdr.len;
455 
456 	PRIV_RLOCK(priv, &priv_tracker);
457 	hook = *get_hook_from_iffam(priv, iffam);
458 	if (hook == NULL) {
459 		NG_FREE_M(m);
460 		PRIV_RUNLOCK(priv, &priv_tracker);
461 		return ENETDOWN;
462 	}
463 	NG_HOOK_REF(hook);
464 	PRIV_RUNLOCK(priv, &priv_tracker);
465 
466 	NG_OUTBOUND_THREAD_REF();
467 	NG_SEND_DATA_ONLY(error, hook, m);
468 	NG_OUTBOUND_THREAD_UNREF();
469 	NG_HOOK_UNREF(hook);
470 
471 	/* Update stats. */
472 	if (error == 0) {
473 		if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
474 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
475 	}
476 
477 	return (error);
478 }
479 
480 #ifdef DEBUG
481 /*
482  * Display an ioctl to the virtual interface
483  */
484 
485 static void
486 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
487 {
488 	char   *str;
489 
490 	switch (command & IOC_DIRMASK) {
491 	case IOC_VOID:
492 		str = "IO";
493 		break;
494 	case IOC_OUT:
495 		str = "IOR";
496 		break;
497 	case IOC_IN:
498 		str = "IOW";
499 		break;
500 	case IOC_INOUT:
501 		str = "IORW";
502 		break;
503 	default:
504 		str = "IO??";
505 	}
506 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
507 	       ifp->if_xname,
508 	       str,
509 	       IOCGROUP(command),
510 	       command & 0xff,
511 	       IOCPARM_LEN(command));
512 }
513 #endif /* DEBUG */
514 
515 /************************************************************************
516 			NETGRAPH NODE STUFF
517  ************************************************************************/
518 
519 /*
520  * Constructor for a node
521  */
522 static int
523 ng_iface_constructor(node_p node)
524 {
525 	struct ifnet *ifp;
526 	priv_p priv;
527 
528 	/* Allocate node and interface private structures */
529 	priv = malloc(sizeof(*priv), M_NETGRAPH_IFACE, M_WAITOK | M_ZERO);
530 	ifp = if_alloc(IFT_PROPVIRTUAL);
531 	if (ifp == NULL) {
532 		free(priv, M_NETGRAPH_IFACE);
533 		return (ENOMEM);
534 	}
535 
536 	rm_init(&priv->lock, "ng_iface private rmlock");
537 
538 	/* Link them together */
539 	ifp->if_softc = priv;
540 	priv->ifp = ifp;
541 
542 	/* Get an interface unit number */
543 	priv->unit = alloc_unr(V_ng_iface_unit);
544 
545 	/* Link together node and private info */
546 	NG_NODE_SET_PRIVATE(node, priv);
547 	priv->node = node;
548 
549 	/* Initialize interface structure */
550 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
551 	ifp->if_output = ng_iface_output;
552 	ifp->if_start = ng_iface_start;
553 	ifp->if_ioctl = ng_iface_ioctl;
554 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
555 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
556 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
557 	ifp->if_addrlen = 0;			/* XXX */
558 	ifp->if_hdrlen = 0;			/* XXX */
559 	ifp->if_baudrate = 64000;		/* XXX */
560 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
561 	ifp->if_snd.ifq_drv_maxlen = ifqmaxlen;
562 	IFQ_SET_READY(&ifp->if_snd);
563 
564 	/* Give this node the same name as the interface (if possible) */
565 	if (ng_name_node(node, ifp->if_xname) != 0)
566 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
567 		    ifp->if_xname);
568 
569 	/* Attach the interface */
570 	if_attach(ifp);
571 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
572 
573 	/* Done */
574 	return (0);
575 }
576 
577 /*
578  * Give our ok for a hook to be added
579  */
580 static int
581 ng_iface_newhook(node_p node, hook_p hook, const char *name)
582 {
583 	const iffam_p iffam = get_iffam_from_name(name);
584 	const priv_p priv = NG_NODE_PRIVATE(node);
585 	hook_p *hookptr;
586 
587 	if (iffam == NULL)
588 		return (EPFNOSUPPORT);
589 	PRIV_WLOCK(priv);
590 	hookptr = get_hook_from_iffam(priv, iffam);
591 	if (*hookptr != NULL) {
592 		PRIV_WUNLOCK(priv);
593 		return (EISCONN);
594 	}
595 	*hookptr = hook;
596 	NG_HOOK_HI_STACK(hook);
597 	NG_HOOK_SET_TO_INBOUND(hook);
598 	PRIV_WUNLOCK(priv);
599 	return (0);
600 }
601 
602 /*
603  * Receive a control message
604  */
605 static int
606 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
607 {
608 	const priv_p priv = NG_NODE_PRIVATE(node);
609 	struct ifnet *const ifp = priv->ifp;
610 	struct ng_mesg *resp = NULL;
611 	int error = 0;
612 	struct ng_mesg *msg;
613 
614 	NGI_GET_MSG(item, msg);
615 	switch (msg->header.typecookie) {
616 	case NGM_IFACE_COOKIE:
617 		switch (msg->header.cmd) {
618 		case NGM_IFACE_GET_IFNAME:
619 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
620 			if (resp == NULL) {
621 				error = ENOMEM;
622 				break;
623 			}
624 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
625 			break;
626 
627 		case NGM_IFACE_POINT2POINT:
628 		case NGM_IFACE_BROADCAST:
629 		    {
630 
631 			/* Deny request if interface is UP */
632 			if ((ifp->if_flags & IFF_UP) != 0)
633 				return (EBUSY);
634 
635 			/* Change flags */
636 			switch (msg->header.cmd) {
637 			case NGM_IFACE_POINT2POINT:
638 				ifp->if_flags |= IFF_POINTOPOINT;
639 				ifp->if_flags &= ~IFF_BROADCAST;
640 				break;
641 			case NGM_IFACE_BROADCAST:
642 				ifp->if_flags &= ~IFF_POINTOPOINT;
643 				ifp->if_flags |= IFF_BROADCAST;
644 				break;
645 			}
646 			break;
647 		    }
648 
649 		case NGM_IFACE_GET_IFINDEX:
650 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
651 			if (resp == NULL) {
652 				error = ENOMEM;
653 				break;
654 			}
655 			*((uint32_t *)resp->data) = priv->ifp->if_index;
656 			break;
657 
658 		default:
659 			error = EINVAL;
660 			break;
661 		}
662 		break;
663 	case NGM_FLOW_COOKIE:
664 		switch (msg->header.cmd) {
665 		case NGM_LINK_IS_UP:
666 			if_link_state_change(ifp, LINK_STATE_UP);
667 			break;
668 		case NGM_LINK_IS_DOWN:
669 			if_link_state_change(ifp, LINK_STATE_DOWN);
670 			break;
671 		default:
672 			break;
673 		}
674 		break;
675 	default:
676 		error = EINVAL;
677 		break;
678 	}
679 	NG_RESPOND_MSG(error, node, item, resp);
680 	NG_FREE_MSG(msg);
681 	return (error);
682 }
683 
684 /*
685  * Recive data from a hook. Pass the packet to the correct input routine.
686  */
687 static int
688 ng_iface_rcvdata(hook_p hook, item_p item)
689 {
690 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
691 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
692 	struct ifnet *const ifp = priv->ifp;
693 	struct epoch_tracker et;
694 	struct mbuf *m;
695 	int isr;
696 
697 	NGI_GET_M(item, m);
698 	NG_FREE_ITEM(item);
699 	/* Sanity checks */
700 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
701 	M_ASSERTPKTHDR(m);
702 	if ((ifp->if_flags & IFF_UP) == 0) {
703 		NG_FREE_M(m);
704 		return (ENETDOWN);
705 	}
706 
707 	/* Update interface stats */
708 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
709 	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
710 
711 	/* Note receiving interface */
712 	m->m_pkthdr.rcvif = ifp;
713 
714 	/* Berkeley packet filter */
715 	ng_iface_bpftap(ifp, m, iffam->family);
716 
717 	/* Send packet */
718 	switch (iffam->family) {
719 #ifdef INET
720 	case AF_INET:
721 		isr = NETISR_IP;
722 		break;
723 #endif
724 #ifdef INET6
725 	case AF_INET6:
726 		isr = NETISR_IPV6;
727 		break;
728 #endif
729 	default:
730 		m_freem(m);
731 		return (EAFNOSUPPORT);
732 	}
733 	random_harvest_queue(m, sizeof(*m), RANDOM_NET_NG);
734 	M_SETFIB(m, ifp->if_fib);
735 	NET_EPOCH_ENTER(et);
736 	netisr_dispatch(isr, m);
737 	NET_EPOCH_EXIT(et);
738 	return (0);
739 }
740 
741 /*
742  * Shutdown and remove the node and its associated interface.
743  */
744 static int
745 ng_iface_shutdown(node_p node)
746 {
747 	const priv_p priv = NG_NODE_PRIVATE(node);
748 
749 	/*
750 	 * The ifnet may be in a different vnet than the netgraph node,
751 	 * hence we have to change the current vnet context here.
752 	 */
753 	CURVNET_SET_QUIET(priv->ifp->if_vnet);
754 	bpfdetach(priv->ifp);
755 	if_detach(priv->ifp);
756 	if_free(priv->ifp);
757 	CURVNET_RESTORE();
758 	priv->ifp = NULL;
759 	free_unr(V_ng_iface_unit, priv->unit);
760 	rm_destroy(&priv->lock);
761 	free(priv, M_NETGRAPH_IFACE);
762 	NG_NODE_SET_PRIVATE(node, NULL);
763 	NG_NODE_UNREF(node);
764 	return (0);
765 }
766 
767 /*
768  * Hook disconnection. Note that we do *not* shutdown when all
769  * hooks have been disconnected.
770  */
771 static int
772 ng_iface_disconnect(hook_p hook)
773 {
774 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
775 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
776 
777 	if (iffam == NULL)
778 		panic("%s", __func__);
779 	PRIV_WLOCK(priv);
780 	*get_hook_from_iffam(priv, iffam) = NULL;
781 	PRIV_WUNLOCK(priv);
782 	return (0);
783 }
784 
785 /*
786  * Handle loading and unloading for this node type.
787  */
788 static int
789 ng_iface_mod_event(module_t mod, int event, void *data)
790 {
791 	int error = 0;
792 
793 	switch (event) {
794 	case MOD_LOAD:
795 	case MOD_UNLOAD:
796 		break;
797 	default:
798 		error = EOPNOTSUPP;
799 		break;
800 	}
801 	return (error);
802 }
803 
804 static void
805 vnet_ng_iface_init(const void *unused)
806 {
807 
808 	V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
809 }
810 VNET_SYSINIT(vnet_ng_iface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
811     vnet_ng_iface_init, NULL);
812 
813 static void
814 vnet_ng_iface_uninit(const void *unused)
815 {
816 
817 	delete_unrhdr(V_ng_iface_unit);
818 }
819 VNET_SYSUNINIT(vnet_ng_iface_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
820     vnet_ng_iface_uninit, NULL);
821