xref: /freebsd/sys/netgraph/ng_iface.c (revision e9b1dc32c9bd2ebae5f9e140bfa0e0321bc366b5)
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/syslog.h>
72 #include <sys/libkern.h>
73 
74 #include <net/if.h>
75 #include <net/if_var.h>
76 #include <net/if_types.h>
77 #include <net/bpf.h>
78 #include <net/netisr.h>
79 #include <net/route.h>
80 #include <net/vnet.h>
81 
82 #include <netinet/in.h>
83 
84 #include <netgraph/ng_message.h>
85 #include <netgraph/netgraph.h>
86 #include <netgraph/ng_parse.h>
87 #include <netgraph/ng_iface.h>
88 
89 #ifdef NG_SEPARATE_MALLOC
90 static MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node");
91 #else
92 #define M_NETGRAPH_IFACE M_NETGRAPH
93 #endif
94 
95 /* This struct describes one address family */
96 struct iffam {
97 	sa_family_t	family;		/* Address family */
98 	const char	*hookname;	/* Name for hook */
99 };
100 typedef const struct iffam *iffam_p;
101 
102 /* List of address families supported by our interface */
103 const static struct iffam gFamilies[] = {
104 	{ AF_INET,	NG_IFACE_HOOK_INET	},
105 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
106 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
107 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
108 };
109 #define	NUM_FAMILIES		nitems(gFamilies)
110 
111 /* Node private data */
112 struct ng_iface_private {
113 	struct	ifnet *ifp;		/* Our interface */
114 	int	unit;			/* Interface unit number */
115 	node_p	node;			/* Our netgraph node */
116 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
117 	struct rmlock	lock;		/* Protect private data changes */
118 };
119 typedef struct ng_iface_private *priv_p;
120 
121 #define	PRIV_RLOCK(priv, t)	rm_rlock(&priv->lock, t)
122 #define	PRIV_RUNLOCK(priv, t)	rm_runlock(&priv->lock, t)
123 #define	PRIV_WLOCK(priv)	rm_wlock(&priv->lock)
124 #define	PRIV_WUNLOCK(priv)	rm_wunlock(&priv->lock)
125 
126 /* Interface methods */
127 static void	ng_iface_start(struct ifnet *ifp);
128 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
129 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
130     			const struct sockaddr *dst, struct route *ro);
131 static void	ng_iface_bpftap(struct ifnet *ifp,
132 			struct mbuf *m, sa_family_t family);
133 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
134 			sa_family_t sa);
135 #ifdef DEBUG
136 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
137 #endif
138 
139 /* Netgraph methods */
140 static int		ng_iface_mod_event(module_t, int, void *);
141 static ng_constructor_t	ng_iface_constructor;
142 static ng_rcvmsg_t	ng_iface_rcvmsg;
143 static ng_shutdown_t	ng_iface_shutdown;
144 static ng_newhook_t	ng_iface_newhook;
145 static ng_rcvdata_t	ng_iface_rcvdata;
146 static ng_disconnect_t	ng_iface_disconnect;
147 
148 /* Helper stuff */
149 static iffam_p	get_iffam_from_af(sa_family_t family);
150 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
151 static iffam_p	get_iffam_from_name(const char *name);
152 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
153 
154 /* List of commands and how to convert arguments to/from ASCII */
155 static const struct ng_cmdlist ng_iface_cmds[] = {
156 	{
157 	  NGM_IFACE_COOKIE,
158 	  NGM_IFACE_GET_IFNAME,
159 	  "getifname",
160 	  NULL,
161 	  &ng_parse_string_type
162 	},
163 	{
164 	  NGM_IFACE_COOKIE,
165 	  NGM_IFACE_POINT2POINT,
166 	  "point2point",
167 	  NULL,
168 	  NULL
169 	},
170 	{
171 	  NGM_IFACE_COOKIE,
172 	  NGM_IFACE_BROADCAST,
173 	  "broadcast",
174 	  NULL,
175 	  NULL
176 	},
177 	{
178 	  NGM_IFACE_COOKIE,
179 	  NGM_IFACE_GET_IFINDEX,
180 	  "getifindex",
181 	  NULL,
182 	  &ng_parse_uint32_type
183 	},
184 	{ 0 }
185 };
186 
187 /* Node type descriptor */
188 static struct ng_type typestruct = {
189 	.version =	NG_ABI_VERSION,
190 	.name =		NG_IFACE_NODE_TYPE,
191 	.mod_event =	ng_iface_mod_event,
192 	.constructor =	ng_iface_constructor,
193 	.rcvmsg =	ng_iface_rcvmsg,
194 	.shutdown =	ng_iface_shutdown,
195 	.newhook =	ng_iface_newhook,
196 	.rcvdata =	ng_iface_rcvdata,
197 	.disconnect =	ng_iface_disconnect,
198 	.cmdlist =	ng_iface_cmds,
199 };
200 NETGRAPH_INIT(iface, &typestruct);
201 
202 VNET_DEFINE_STATIC(struct unrhdr *, ng_iface_unit);
203 #define	V_ng_iface_unit			VNET(ng_iface_unit)
204 
205 /************************************************************************
206 			HELPER STUFF
207  ************************************************************************/
208 
209 /*
210  * Get the family descriptor from the family ID
211  */
212 static __inline iffam_p
213 get_iffam_from_af(sa_family_t family)
214 {
215 	iffam_p iffam;
216 	int k;
217 
218 	for (k = 0; k < NUM_FAMILIES; k++) {
219 		iffam = &gFamilies[k];
220 		if (iffam->family == family)
221 			return (iffam);
222 	}
223 	return (NULL);
224 }
225 
226 /*
227  * Get the family descriptor from the hook
228  */
229 static __inline iffam_p
230 get_iffam_from_hook(priv_p priv, hook_p hook)
231 {
232 	int k;
233 
234 	for (k = 0; k < NUM_FAMILIES; k++)
235 		if (priv->hooks[k] == hook)
236 			return (&gFamilies[k]);
237 	return (NULL);
238 }
239 
240 /*
241  * Get the hook from the iffam descriptor
242  */
243 
244 static __inline hook_p *
245 get_hook_from_iffam(priv_p priv, iffam_p iffam)
246 {
247 	return (&priv->hooks[iffam - gFamilies]);
248 }
249 
250 /*
251  * Get the iffam descriptor from the name
252  */
253 static __inline iffam_p
254 get_iffam_from_name(const char *name)
255 {
256 	iffam_p iffam;
257 	int k;
258 
259 	for (k = 0; k < NUM_FAMILIES; k++) {
260 		iffam = &gFamilies[k];
261 		if (!strcmp(iffam->hookname, name))
262 			return (iffam);
263 	}
264 	return (NULL);
265 }
266 
267 /************************************************************************
268 			INTERFACE STUFF
269  ************************************************************************/
270 
271 /*
272  * Process an ioctl for the virtual interface
273  */
274 static int
275 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
276 {
277 	struct ifreq *const ifr = (struct ifreq *) data;
278 	int error = 0;
279 
280 #ifdef DEBUG
281 	ng_iface_print_ioctl(ifp, command, data);
282 #endif
283 	switch (command) {
284 
285 	/* These two are mostly handled at a higher layer */
286 	case SIOCSIFADDR:
287 		ifp->if_flags |= IFF_UP;
288 		ifp->if_drv_flags |= IFF_DRV_RUNNING;
289 		ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
290 		break;
291 	case SIOCGIFADDR:
292 		break;
293 
294 	/* Set flags */
295 	case SIOCSIFFLAGS:
296 		/*
297 		 * If the interface is marked up and stopped, then start it.
298 		 * If it is marked down and running, then stop it.
299 		 */
300 		if (ifr->ifr_flags & IFF_UP) {
301 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
302 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
303 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
304 			}
305 		} else {
306 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
307 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
308 				    IFF_DRV_OACTIVE);
309 		}
310 		break;
311 
312 	/* Set the interface MTU */
313 	case SIOCSIFMTU:
314 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
315 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
316 			error = EINVAL;
317 		else
318 			ifp->if_mtu = ifr->ifr_mtu;
319 		break;
320 
321 	/* Stuff that's not supported */
322 	case SIOCADDMULTI:
323 	case SIOCDELMULTI:
324 		error = 0;
325 		break;
326 	case SIOCSIFPHYS:
327 		error = EOPNOTSUPP;
328 		break;
329 
330 	default:
331 		error = EINVAL;
332 		break;
333 	}
334 	return (error);
335 }
336 
337 /*
338  * This routine is called to deliver a packet out the interface.
339  * We simply look at the address family and relay the packet to
340  * the corresponding hook, if it exists and is connected.
341  */
342 
343 static int
344 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
345 	const struct sockaddr *dst, struct route *ro)
346 {
347 	uint32_t af;
348 	int error;
349 
350 	/* Check interface flags */
351 	if (!((ifp->if_flags & IFF_UP) &&
352 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
353 		m_freem(m);
354 		return (ENETDOWN);
355 	}
356 
357 	/* Protect from deadly infinite recursion. */
358 	error = if_tunnel_check_nesting(ifp, m, NGM_IFACE_COOKIE, 1);
359 	if (error) {
360 		m_freem(m);
361 		return (error);
362 	}
363 
364 	/* BPF writes need to be handled specially. */
365 	if (dst->sa_family == AF_UNSPEC)
366 		bcopy(dst->sa_data, &af, sizeof(af));
367 	else
368 		af = dst->sa_family;
369 
370 	/* Berkeley packet filter */
371 	ng_iface_bpftap(ifp, m, af);
372 
373 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
374 		M_PREPEND(m, sizeof(sa_family_t), M_NOWAIT);
375 		if (m == NULL) {
376 			if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
377 			return (ENOBUFS);
378 		}
379 		*(sa_family_t *)m->m_data = af;
380 		error = (ifp->if_transmit)(ifp, m);
381 	} else
382 		error = ng_iface_send(ifp, m, af);
383 
384 	return (error);
385 }
386 
387 /*
388  * Start method is used only when ALTQ is enabled.
389  */
390 static void
391 ng_iface_start(struct ifnet *ifp)
392 {
393 	struct mbuf *m;
394 	sa_family_t sa;
395 
396 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
397 
398 	for(;;) {
399 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
400 		if (m == NULL)
401 			break;
402 		sa = *mtod(m, sa_family_t *);
403 		m_adj(m, sizeof(sa_family_t));
404 		ng_iface_send(ifp, m, sa);
405 	}
406 }
407 
408 /*
409  * Flash a packet by the BPF (requires prepending 4 byte AF header)
410  * Note the phoney mbuf; this is OK because BPF treats it read-only.
411  */
412 static void
413 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
414 {
415 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
416 	if (bpf_peers_present(ifp->if_bpf)) {
417 		int32_t family4 = (int32_t)family;
418 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
419 	}
420 }
421 
422 /*
423  * This routine does actual delivery of the packet into the
424  * netgraph(4). It is called from ng_iface_start() and
425  * ng_iface_output().
426  */
427 static int
428 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
429 {
430 	struct rm_priotracker priv_tracker;
431 	const priv_p priv = (priv_p) ifp->if_softc;
432 	const iffam_p iffam = get_iffam_from_af(sa);
433 	hook_p hook;
434 	int error;
435 	int len;
436 
437 	/* Check address family to determine hook (if known) */
438 	if (iffam == NULL) {
439 		m_freem(m);
440 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
441 		return (EAFNOSUPPORT);
442 	}
443 
444 	/* Copy length before the mbuf gets invalidated. */
445 	len = m->m_pkthdr.len;
446 
447 	PRIV_RLOCK(priv, &priv_tracker);
448 	hook = *get_hook_from_iffam(priv, iffam);
449 	if (hook == NULL) {
450 		NG_FREE_M(m);
451 		PRIV_RUNLOCK(priv, &priv_tracker);
452 		return ENETDOWN;
453 	}
454 	NG_HOOK_REF(hook);
455 	PRIV_RUNLOCK(priv, &priv_tracker);
456 
457 	NG_OUTBOUND_THREAD_REF();
458 	NG_SEND_DATA_ONLY(error, hook, m);
459 	NG_OUTBOUND_THREAD_UNREF();
460 	NG_HOOK_UNREF(hook);
461 
462 	/* Update stats. */
463 	if (error == 0) {
464 		if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
465 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
466 	}
467 
468 	return (error);
469 }
470 
471 #ifdef DEBUG
472 /*
473  * Display an ioctl to the virtual interface
474  */
475 
476 static void
477 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
478 {
479 	char   *str;
480 
481 	switch (command & IOC_DIRMASK) {
482 	case IOC_VOID:
483 		str = "IO";
484 		break;
485 	case IOC_OUT:
486 		str = "IOR";
487 		break;
488 	case IOC_IN:
489 		str = "IOW";
490 		break;
491 	case IOC_INOUT:
492 		str = "IORW";
493 		break;
494 	default:
495 		str = "IO??";
496 	}
497 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
498 	       ifp->if_xname,
499 	       str,
500 	       IOCGROUP(command),
501 	       command & 0xff,
502 	       IOCPARM_LEN(command));
503 }
504 #endif /* DEBUG */
505 
506 /************************************************************************
507 			NETGRAPH NODE STUFF
508  ************************************************************************/
509 
510 /*
511  * Constructor for a node
512  */
513 static int
514 ng_iface_constructor(node_p node)
515 {
516 	struct ifnet *ifp;
517 	priv_p priv;
518 
519 	/* Allocate node and interface private structures */
520 	priv = malloc(sizeof(*priv), M_NETGRAPH_IFACE, M_WAITOK | M_ZERO);
521 	ifp = if_alloc(IFT_PROPVIRTUAL);
522 	if (ifp == NULL) {
523 		free(priv, M_NETGRAPH_IFACE);
524 		return (ENOMEM);
525 	}
526 
527 	rm_init(&priv->lock, "ng_iface private rmlock");
528 
529 	/* Link them together */
530 	ifp->if_softc = priv;
531 	priv->ifp = ifp;
532 
533 	/* Get an interface unit number */
534 	priv->unit = alloc_unr(V_ng_iface_unit);
535 
536 	/* Link together node and private info */
537 	NG_NODE_SET_PRIVATE(node, priv);
538 	priv->node = node;
539 
540 	/* Initialize interface structure */
541 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
542 	ifp->if_output = ng_iface_output;
543 	ifp->if_start = ng_iface_start;
544 	ifp->if_ioctl = ng_iface_ioctl;
545 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
546 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
547 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
548 	ifp->if_addrlen = 0;			/* XXX */
549 	ifp->if_hdrlen = 0;			/* XXX */
550 	ifp->if_baudrate = 64000;		/* XXX */
551 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
552 	ifp->if_snd.ifq_drv_maxlen = ifqmaxlen;
553 	IFQ_SET_READY(&ifp->if_snd);
554 
555 	/* Give this node the same name as the interface (if possible) */
556 	if (ng_name_node(node, ifp->if_xname) != 0)
557 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
558 		    ifp->if_xname);
559 
560 	/* Attach the interface */
561 	if_attach(ifp);
562 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
563 
564 	/* Done */
565 	return (0);
566 }
567 
568 /*
569  * Give our ok for a hook to be added
570  */
571 static int
572 ng_iface_newhook(node_p node, hook_p hook, const char *name)
573 {
574 	const iffam_p iffam = get_iffam_from_name(name);
575 	const priv_p priv = NG_NODE_PRIVATE(node);
576 	hook_p *hookptr;
577 
578 	if (iffam == NULL)
579 		return (EPFNOSUPPORT);
580 	PRIV_WLOCK(priv);
581 	hookptr = get_hook_from_iffam(priv, iffam);
582 	if (*hookptr != NULL) {
583 		PRIV_WUNLOCK(priv);
584 		return (EISCONN);
585 	}
586 	*hookptr = hook;
587 	NG_HOOK_HI_STACK(hook);
588 	NG_HOOK_SET_TO_INBOUND(hook);
589 	PRIV_WUNLOCK(priv);
590 	return (0);
591 }
592 
593 /*
594  * Receive a control message
595  */
596 static int
597 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
598 {
599 	const priv_p priv = NG_NODE_PRIVATE(node);
600 	struct ifnet *const ifp = priv->ifp;
601 	struct ng_mesg *resp = NULL;
602 	int error = 0;
603 	struct ng_mesg *msg;
604 
605 	NGI_GET_MSG(item, msg);
606 	switch (msg->header.typecookie) {
607 	case NGM_IFACE_COOKIE:
608 		switch (msg->header.cmd) {
609 		case NGM_IFACE_GET_IFNAME:
610 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
611 			if (resp == NULL) {
612 				error = ENOMEM;
613 				break;
614 			}
615 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
616 			break;
617 
618 		case NGM_IFACE_POINT2POINT:
619 		case NGM_IFACE_BROADCAST:
620 		    {
621 
622 			/* Deny request if interface is UP */
623 			if ((ifp->if_flags & IFF_UP) != 0)
624 				return (EBUSY);
625 
626 			/* Change flags */
627 			switch (msg->header.cmd) {
628 			case NGM_IFACE_POINT2POINT:
629 				ifp->if_flags |= IFF_POINTOPOINT;
630 				ifp->if_flags &= ~IFF_BROADCAST;
631 				break;
632 			case NGM_IFACE_BROADCAST:
633 				ifp->if_flags &= ~IFF_POINTOPOINT;
634 				ifp->if_flags |= IFF_BROADCAST;
635 				break;
636 			}
637 			break;
638 		    }
639 
640 		case NGM_IFACE_GET_IFINDEX:
641 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
642 			if (resp == NULL) {
643 				error = ENOMEM;
644 				break;
645 			}
646 			*((uint32_t *)resp->data) = priv->ifp->if_index;
647 			break;
648 
649 		default:
650 			error = EINVAL;
651 			break;
652 		}
653 		break;
654 	case NGM_FLOW_COOKIE:
655 		switch (msg->header.cmd) {
656 		case NGM_LINK_IS_UP:
657 			if_link_state_change(ifp, LINK_STATE_UP);
658 			break;
659 		case NGM_LINK_IS_DOWN:
660 			if_link_state_change(ifp, LINK_STATE_DOWN);
661 			break;
662 		default:
663 			break;
664 		}
665 		break;
666 	default:
667 		error = EINVAL;
668 		break;
669 	}
670 	NG_RESPOND_MSG(error, node, item, resp);
671 	NG_FREE_MSG(msg);
672 	return (error);
673 }
674 
675 /*
676  * Recive data from a hook. Pass the packet to the correct input routine.
677  */
678 static int
679 ng_iface_rcvdata(hook_p hook, item_p item)
680 {
681 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
682 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
683 	struct ifnet *const ifp = priv->ifp;
684 	struct mbuf *m;
685 	int isr;
686 
687 	NGI_GET_M(item, m);
688 	NG_FREE_ITEM(item);
689 	/* Sanity checks */
690 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
691 	M_ASSERTPKTHDR(m);
692 	if ((ifp->if_flags & IFF_UP) == 0) {
693 		NG_FREE_M(m);
694 		return (ENETDOWN);
695 	}
696 
697 	/* Update interface stats */
698 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
699 	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
700 
701 	/* Note receiving interface */
702 	m->m_pkthdr.rcvif = ifp;
703 
704 	/* Berkeley packet filter */
705 	ng_iface_bpftap(ifp, m, iffam->family);
706 
707 	/* Send packet */
708 	switch (iffam->family) {
709 #ifdef INET
710 	case AF_INET:
711 		isr = NETISR_IP;
712 		break;
713 #endif
714 #ifdef INET6
715 	case AF_INET6:
716 		isr = NETISR_IPV6;
717 		break;
718 #endif
719 	default:
720 		m_freem(m);
721 		return (EAFNOSUPPORT);
722 	}
723 	random_harvest_queue(m, sizeof(*m), RANDOM_NET_NG);
724 	M_SETFIB(m, ifp->if_fib);
725 	netisr_dispatch(isr, m);
726 	return (0);
727 }
728 
729 /*
730  * Shutdown and remove the node and its associated interface.
731  */
732 static int
733 ng_iface_shutdown(node_p node)
734 {
735 	const priv_p priv = NG_NODE_PRIVATE(node);
736 
737 	/*
738 	 * The ifnet may be in a different vnet than the netgraph node,
739 	 * hence we have to change the current vnet context here.
740 	 */
741 	CURVNET_SET_QUIET(priv->ifp->if_vnet);
742 	bpfdetach(priv->ifp);
743 	if_detach(priv->ifp);
744 	if_free(priv->ifp);
745 	CURVNET_RESTORE();
746 	priv->ifp = NULL;
747 	free_unr(V_ng_iface_unit, priv->unit);
748 	rm_destroy(&priv->lock);
749 	free(priv, M_NETGRAPH_IFACE);
750 	NG_NODE_SET_PRIVATE(node, NULL);
751 	NG_NODE_UNREF(node);
752 	return (0);
753 }
754 
755 /*
756  * Hook disconnection. Note that we do *not* shutdown when all
757  * hooks have been disconnected.
758  */
759 static int
760 ng_iface_disconnect(hook_p hook)
761 {
762 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
763 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
764 
765 	if (iffam == NULL)
766 		panic("%s", __func__);
767 	PRIV_WLOCK(priv);
768 	*get_hook_from_iffam(priv, iffam) = NULL;
769 	PRIV_WUNLOCK(priv);
770 	return (0);
771 }
772 
773 /*
774  * Handle loading and unloading for this node type.
775  */
776 static int
777 ng_iface_mod_event(module_t mod, int event, void *data)
778 {
779 	int error = 0;
780 
781 	switch (event) {
782 	case MOD_LOAD:
783 	case MOD_UNLOAD:
784 		break;
785 	default:
786 		error = EOPNOTSUPP;
787 		break;
788 	}
789 	return (error);
790 }
791 
792 static void
793 vnet_ng_iface_init(const void *unused)
794 {
795 
796 	V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
797 }
798 VNET_SYSINIT(vnet_ng_iface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
799     vnet_ng_iface_init, NULL);
800 
801 static void
802 vnet_ng_iface_uninit(const void *unused)
803 {
804 
805 	delete_unrhdr(V_ng_iface_unit);
806 }
807 VNET_SYSUNINIT(vnet_ng_iface_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
808     vnet_ng_iface_uninit, NULL);
809