xref: /freebsd/sys/netgraph/ng_iface.c (revision a96ef4501919d7ac08e94e98dc34b0bdd744802b)
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 };
115 #define	NUM_FAMILIES		nitems(gFamilies)
116 
117 /* Node private data */
118 struct ng_iface_private {
119 	struct	ifnet *ifp;		/* Our interface */
120 	int	unit;			/* Interface unit number */
121 	node_p	node;			/* Our netgraph node */
122 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
123 	struct rmlock	lock;		/* Protect private data changes */
124 };
125 typedef struct ng_iface_private *priv_p;
126 
127 #define	PRIV_RLOCK(priv, t)	rm_rlock(&priv->lock, t)
128 #define	PRIV_RUNLOCK(priv, t)	rm_runlock(&priv->lock, t)
129 #define	PRIV_WLOCK(priv)	rm_wlock(&priv->lock)
130 #define	PRIV_WUNLOCK(priv)	rm_wunlock(&priv->lock)
131 
132 /* Interface methods */
133 static void	ng_iface_start(struct ifnet *ifp);
134 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
135 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
136     			const struct sockaddr *dst, struct route *ro);
137 static void	ng_iface_bpftap(struct ifnet *ifp,
138 			struct mbuf *m, sa_family_t family);
139 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
140 			sa_family_t sa);
141 #ifdef DEBUG
142 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
143 #endif
144 
145 /* Netgraph methods */
146 static int		ng_iface_mod_event(module_t, int, void *);
147 static ng_constructor_t	ng_iface_constructor;
148 static ng_rcvmsg_t	ng_iface_rcvmsg;
149 static ng_shutdown_t	ng_iface_shutdown;
150 static ng_newhook_t	ng_iface_newhook;
151 static ng_rcvdata_t	ng_iface_rcvdata;
152 static ng_disconnect_t	ng_iface_disconnect;
153 
154 /* Helper stuff */
155 static iffam_p	get_iffam_from_af(sa_family_t family);
156 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
157 static iffam_p	get_iffam_from_name(const char *name);
158 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
159 
160 /* List of commands and how to convert arguments to/from ASCII */
161 static const struct ng_cmdlist ng_iface_cmds[] = {
162 	{
163 	  NGM_IFACE_COOKIE,
164 	  NGM_IFACE_GET_IFNAME,
165 	  "getifname",
166 	  NULL,
167 	  &ng_parse_string_type
168 	},
169 	{
170 	  NGM_IFACE_COOKIE,
171 	  NGM_IFACE_POINT2POINT,
172 	  "point2point",
173 	  NULL,
174 	  NULL
175 	},
176 	{
177 	  NGM_IFACE_COOKIE,
178 	  NGM_IFACE_BROADCAST,
179 	  "broadcast",
180 	  NULL,
181 	  NULL
182 	},
183 	{
184 	  NGM_IFACE_COOKIE,
185 	  NGM_IFACE_GET_IFINDEX,
186 	  "getifindex",
187 	  NULL,
188 	  &ng_parse_uint32_type
189 	},
190 	{ 0 }
191 };
192 
193 /* Node type descriptor */
194 static struct ng_type typestruct = {
195 	.version =	NG_ABI_VERSION,
196 	.name =		NG_IFACE_NODE_TYPE,
197 	.mod_event =	ng_iface_mod_event,
198 	.constructor =	ng_iface_constructor,
199 	.rcvmsg =	ng_iface_rcvmsg,
200 	.shutdown =	ng_iface_shutdown,
201 	.newhook =	ng_iface_newhook,
202 	.rcvdata =	ng_iface_rcvdata,
203 	.disconnect =	ng_iface_disconnect,
204 	.cmdlist =	ng_iface_cmds,
205 };
206 NETGRAPH_INIT(iface, &typestruct);
207 
208 VNET_DEFINE_STATIC(struct unrhdr *, ng_iface_unit);
209 #define	V_ng_iface_unit			VNET(ng_iface_unit)
210 
211 /************************************************************************
212 			HELPER STUFF
213  ************************************************************************/
214 
215 /*
216  * Get the family descriptor from the family ID
217  */
218 static __inline iffam_p
219 get_iffam_from_af(sa_family_t family)
220 {
221 	iffam_p iffam;
222 	int k;
223 
224 	for (k = 0; k < NUM_FAMILIES; k++) {
225 		iffam = &gFamilies[k];
226 		if (iffam->family == family)
227 			return (iffam);
228 	}
229 	return (NULL);
230 }
231 
232 /*
233  * Get the family descriptor from the hook
234  */
235 static __inline iffam_p
236 get_iffam_from_hook(priv_p priv, hook_p hook)
237 {
238 	int k;
239 
240 	for (k = 0; k < NUM_FAMILIES; k++)
241 		if (priv->hooks[k] == hook)
242 			return (&gFamilies[k]);
243 	return (NULL);
244 }
245 
246 /*
247  * Get the hook from the iffam descriptor
248  */
249 
250 static __inline hook_p *
251 get_hook_from_iffam(priv_p priv, iffam_p iffam)
252 {
253 	return (&priv->hooks[iffam - gFamilies]);
254 }
255 
256 /*
257  * Get the iffam descriptor from the name
258  */
259 static __inline iffam_p
260 get_iffam_from_name(const char *name)
261 {
262 	iffam_p iffam;
263 	int k;
264 
265 	for (k = 0; k < NUM_FAMILIES; k++) {
266 		iffam = &gFamilies[k];
267 		if (!strcmp(iffam->hookname, name))
268 			return (iffam);
269 	}
270 	return (NULL);
271 }
272 
273 /************************************************************************
274 			INTERFACE STUFF
275  ************************************************************************/
276 
277 /*
278  * Process an ioctl for the virtual interface
279  */
280 static int
281 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
282 {
283 	struct ifreq *const ifr = (struct ifreq *) data;
284 	int error = 0;
285 
286 #ifdef DEBUG
287 	ng_iface_print_ioctl(ifp, command, data);
288 #endif
289 	switch (command) {
290 	/* These two are mostly handled at a higher layer */
291 	case SIOCSIFADDR:
292 		ifp->if_flags |= IFF_UP;
293 		ifp->if_drv_flags |= IFF_DRV_RUNNING;
294 		ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
295 		break;
296 	case SIOCGIFADDR:
297 		break;
298 
299 	/* Set flags */
300 	case SIOCSIFFLAGS:
301 		/*
302 		 * If the interface is marked up and stopped, then start it.
303 		 * If it is marked down and running, then stop it.
304 		 */
305 		if (ifr->ifr_flags & IFF_UP) {
306 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
307 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
308 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
309 			}
310 		} else {
311 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
312 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
313 				    IFF_DRV_OACTIVE);
314 		}
315 		break;
316 
317 	/* Set the interface MTU */
318 	case SIOCSIFMTU:
319 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
320 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
321 			error = EINVAL;
322 		else
323 			ifp->if_mtu = ifr->ifr_mtu;
324 		break;
325 
326 	/* Stuff that's not supported */
327 	case SIOCADDMULTI:
328 	case SIOCDELMULTI:
329 		error = 0;
330 		break;
331 	case SIOCSIFPHYS:
332 		error = EOPNOTSUPP;
333 		break;
334 
335 	default:
336 		error = EINVAL;
337 		break;
338 	}
339 	return (error);
340 }
341 
342 /*
343  * This routine is called to deliver a packet out the interface.
344  * We simply look at the address family and relay the packet to
345  * the corresponding hook, if it exists and is connected.
346  */
347 
348 static int
349 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
350 	const struct sockaddr *dst, struct route *ro)
351 {
352 	uint32_t af;
353 	int error;
354 
355 	/* Check interface flags */
356 	if (!((ifp->if_flags & IFF_UP) &&
357 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
358 		m_freem(m);
359 		return (ENETDOWN);
360 	}
361 
362 	/* Protect from deadly infinite recursion. */
363 	error = if_tunnel_check_nesting(ifp, m, NGM_IFACE_COOKIE,
364 	    V_ng_iface_max_nest);
365 	if (error) {
366 		m_freem(m);
367 		return (error);
368 	}
369 
370 	/* BPF writes need to be handled specially. */
371 	if (dst->sa_family == AF_UNSPEC)
372 		bcopy(dst->sa_data, &af, sizeof(af));
373 	else
374 		af = dst->sa_family;
375 
376 	/* Berkeley packet filter */
377 	ng_iface_bpftap(ifp, m, af);
378 
379 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
380 		M_PREPEND(m, sizeof(sa_family_t), M_NOWAIT);
381 		if (m == NULL) {
382 			if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
383 			return (ENOBUFS);
384 		}
385 		*(sa_family_t *)m->m_data = af;
386 		error = (ifp->if_transmit)(ifp, m);
387 	} else
388 		error = ng_iface_send(ifp, m, af);
389 
390 	return (error);
391 }
392 
393 /*
394  * Start method is used only when ALTQ is enabled.
395  */
396 static void
397 ng_iface_start(struct ifnet *ifp)
398 {
399 	struct mbuf *m;
400 	sa_family_t sa;
401 
402 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
403 
404 	for(;;) {
405 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
406 		if (m == NULL)
407 			break;
408 		sa = *mtod(m, sa_family_t *);
409 		m_adj(m, sizeof(sa_family_t));
410 		ng_iface_send(ifp, m, sa);
411 	}
412 }
413 
414 /*
415  * Flash a packet by the BPF (requires prepending 4 byte AF header)
416  * Note the phoney mbuf; this is OK because BPF treats it read-only.
417  */
418 static void
419 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
420 {
421 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
422 	if (bpf_peers_present(ifp->if_bpf)) {
423 		int32_t family4 = (int32_t)family;
424 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
425 	}
426 }
427 
428 /*
429  * This routine does actual delivery of the packet into the
430  * netgraph(4). It is called from ng_iface_start() and
431  * ng_iface_output().
432  */
433 static int
434 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
435 {
436 	struct rm_priotracker priv_tracker;
437 	const priv_p priv = (priv_p) ifp->if_softc;
438 	const iffam_p iffam = get_iffam_from_af(sa);
439 	hook_p hook;
440 	int error;
441 	int len;
442 
443 	/* Check address family to determine hook (if known) */
444 	if (iffam == NULL) {
445 		m_freem(m);
446 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
447 		return (EAFNOSUPPORT);
448 	}
449 
450 	/* Copy length before the mbuf gets invalidated. */
451 	len = m->m_pkthdr.len;
452 
453 	PRIV_RLOCK(priv, &priv_tracker);
454 	hook = *get_hook_from_iffam(priv, iffam);
455 	if (hook == NULL) {
456 		NG_FREE_M(m);
457 		PRIV_RUNLOCK(priv, &priv_tracker);
458 		return ENETDOWN;
459 	}
460 	NG_HOOK_REF(hook);
461 	PRIV_RUNLOCK(priv, &priv_tracker);
462 
463 	NG_OUTBOUND_THREAD_REF();
464 	NG_SEND_DATA_ONLY(error, hook, m);
465 	NG_OUTBOUND_THREAD_UNREF();
466 	NG_HOOK_UNREF(hook);
467 
468 	/* Update stats. */
469 	if (error == 0) {
470 		if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
471 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
472 	}
473 
474 	return (error);
475 }
476 
477 #ifdef DEBUG
478 /*
479  * Display an ioctl to the virtual interface
480  */
481 
482 static void
483 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
484 {
485 	char   *str;
486 
487 	switch (command & IOC_DIRMASK) {
488 	case IOC_VOID:
489 		str = "IO";
490 		break;
491 	case IOC_OUT:
492 		str = "IOR";
493 		break;
494 	case IOC_IN:
495 		str = "IOW";
496 		break;
497 	case IOC_INOUT:
498 		str = "IORW";
499 		break;
500 	default:
501 		str = "IO??";
502 	}
503 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
504 	       ifp->if_xname,
505 	       str,
506 	       IOCGROUP(command),
507 	       command & 0xff,
508 	       IOCPARM_LEN(command));
509 }
510 #endif /* DEBUG */
511 
512 /************************************************************************
513 			NETGRAPH NODE STUFF
514  ************************************************************************/
515 
516 /*
517  * Constructor for a node
518  */
519 static int
520 ng_iface_constructor(node_p node)
521 {
522 	struct ifnet *ifp;
523 	priv_p priv;
524 
525 	/* Allocate node and interface private structures */
526 	priv = malloc(sizeof(*priv), M_NETGRAPH_IFACE, M_WAITOK | M_ZERO);
527 	ifp = if_alloc(IFT_PROPVIRTUAL);
528 	if (ifp == NULL) {
529 		free(priv, M_NETGRAPH_IFACE);
530 		return (ENOMEM);
531 	}
532 
533 	rm_init(&priv->lock, "ng_iface private rmlock");
534 
535 	/* Link them together */
536 	ifp->if_softc = priv;
537 	priv->ifp = ifp;
538 
539 	/* Get an interface unit number */
540 	priv->unit = alloc_unr(V_ng_iface_unit);
541 
542 	/* Link together node and private info */
543 	NG_NODE_SET_PRIVATE(node, priv);
544 	priv->node = node;
545 
546 	/* Initialize interface structure */
547 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
548 	ifp->if_output = ng_iface_output;
549 	ifp->if_start = ng_iface_start;
550 	ifp->if_ioctl = ng_iface_ioctl;
551 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
552 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
553 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
554 	ifp->if_addrlen = 0;			/* XXX */
555 	ifp->if_hdrlen = 0;			/* XXX */
556 	ifp->if_baudrate = 64000;		/* XXX */
557 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
558 	ifp->if_snd.ifq_drv_maxlen = ifqmaxlen;
559 	IFQ_SET_READY(&ifp->if_snd);
560 
561 	/* Give this node the same name as the interface (if possible) */
562 	if (ng_name_node(node, ifp->if_xname) != 0)
563 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
564 		    ifp->if_xname);
565 
566 	/* Attach the interface */
567 	if_attach(ifp);
568 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
569 
570 	/* Done */
571 	return (0);
572 }
573 
574 /*
575  * Give our ok for a hook to be added
576  */
577 static int
578 ng_iface_newhook(node_p node, hook_p hook, const char *name)
579 {
580 	const iffam_p iffam = get_iffam_from_name(name);
581 	const priv_p priv = NG_NODE_PRIVATE(node);
582 	hook_p *hookptr;
583 
584 	if (iffam == NULL)
585 		return (EPFNOSUPPORT);
586 	PRIV_WLOCK(priv);
587 	hookptr = get_hook_from_iffam(priv, iffam);
588 	if (*hookptr != NULL) {
589 		PRIV_WUNLOCK(priv);
590 		return (EISCONN);
591 	}
592 	*hookptr = hook;
593 	NG_HOOK_HI_STACK(hook);
594 	NG_HOOK_SET_TO_INBOUND(hook);
595 	PRIV_WUNLOCK(priv);
596 	return (0);
597 }
598 
599 /*
600  * Receive a control message
601  */
602 static int
603 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
604 {
605 	const priv_p priv = NG_NODE_PRIVATE(node);
606 	struct ifnet *const ifp = priv->ifp;
607 	struct ng_mesg *resp = NULL;
608 	int error = 0;
609 	struct ng_mesg *msg;
610 
611 	NGI_GET_MSG(item, msg);
612 	switch (msg->header.typecookie) {
613 	case NGM_IFACE_COOKIE:
614 		switch (msg->header.cmd) {
615 		case NGM_IFACE_GET_IFNAME:
616 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
617 			if (resp == NULL) {
618 				error = ENOMEM;
619 				break;
620 			}
621 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
622 			break;
623 
624 		case NGM_IFACE_POINT2POINT:
625 		case NGM_IFACE_BROADCAST:
626 		    {
627 			/* Deny request if interface is UP */
628 			if ((ifp->if_flags & IFF_UP) != 0)
629 				return (EBUSY);
630 
631 			/* Change flags */
632 			switch (msg->header.cmd) {
633 			case NGM_IFACE_POINT2POINT:
634 				ifp->if_flags |= IFF_POINTOPOINT;
635 				ifp->if_flags &= ~IFF_BROADCAST;
636 				break;
637 			case NGM_IFACE_BROADCAST:
638 				ifp->if_flags &= ~IFF_POINTOPOINT;
639 				ifp->if_flags |= IFF_BROADCAST;
640 				break;
641 			}
642 			break;
643 		    }
644 
645 		case NGM_IFACE_GET_IFINDEX:
646 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
647 			if (resp == NULL) {
648 				error = ENOMEM;
649 				break;
650 			}
651 			*((uint32_t *)resp->data) = priv->ifp->if_index;
652 			break;
653 
654 		default:
655 			error = EINVAL;
656 			break;
657 		}
658 		break;
659 	case NGM_FLOW_COOKIE:
660 		switch (msg->header.cmd) {
661 		case NGM_LINK_IS_UP:
662 			if_link_state_change(ifp, LINK_STATE_UP);
663 			break;
664 		case NGM_LINK_IS_DOWN:
665 			if_link_state_change(ifp, LINK_STATE_DOWN);
666 			break;
667 		default:
668 			break;
669 		}
670 		break;
671 	default:
672 		error = EINVAL;
673 		break;
674 	}
675 	NG_RESPOND_MSG(error, node, item, resp);
676 	NG_FREE_MSG(msg);
677 	return (error);
678 }
679 
680 /*
681  * Recive data from a hook. Pass the packet to the correct input routine.
682  */
683 static int
684 ng_iface_rcvdata(hook_p hook, item_p item)
685 {
686 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
687 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
688 	struct ifnet *const ifp = priv->ifp;
689 	struct epoch_tracker et;
690 	struct mbuf *m;
691 	int isr;
692 
693 	NGI_GET_M(item, m);
694 	NG_FREE_ITEM(item);
695 	/* Sanity checks */
696 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
697 	M_ASSERTPKTHDR(m);
698 	if ((ifp->if_flags & IFF_UP) == 0) {
699 		NG_FREE_M(m);
700 		return (ENETDOWN);
701 	}
702 
703 	/* Update interface stats */
704 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
705 	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
706 
707 	/* Note receiving interface */
708 	m->m_pkthdr.rcvif = ifp;
709 
710 	/* Berkeley packet filter */
711 	ng_iface_bpftap(ifp, m, iffam->family);
712 
713 	/* Send packet */
714 	switch (iffam->family) {
715 #ifdef INET
716 	case AF_INET:
717 		isr = NETISR_IP;
718 		break;
719 #endif
720 #ifdef INET6
721 	case AF_INET6:
722 		isr = NETISR_IPV6;
723 		break;
724 #endif
725 	default:
726 		m_freem(m);
727 		return (EAFNOSUPPORT);
728 	}
729 	random_harvest_queue(m, sizeof(*m), RANDOM_NET_NG);
730 	M_SETFIB(m, ifp->if_fib);
731 	CURVNET_SET(ifp->if_vnet);
732 	NET_EPOCH_ENTER(et);
733 	netisr_dispatch(isr, m);
734 	NET_EPOCH_EXIT(et);
735 	CURVNET_RESTORE();
736 	return (0);
737 }
738 
739 /*
740  * Shutdown and remove the node and its associated interface.
741  */
742 static int
743 ng_iface_shutdown(node_p node)
744 {
745 	const priv_p priv = NG_NODE_PRIVATE(node);
746 
747 	/*
748 	 * The ifnet may be in a different vnet than the netgraph node,
749 	 * hence we have to change the current vnet context here.
750 	 */
751 	CURVNET_SET_QUIET(priv->ifp->if_vnet);
752 	bpfdetach(priv->ifp);
753 	if_detach(priv->ifp);
754 	if_free(priv->ifp);
755 	CURVNET_RESTORE();
756 	priv->ifp = NULL;
757 	free_unr(V_ng_iface_unit, priv->unit);
758 	rm_destroy(&priv->lock);
759 	free(priv, M_NETGRAPH_IFACE);
760 	NG_NODE_SET_PRIVATE(node, NULL);
761 	NG_NODE_UNREF(node);
762 	return (0);
763 }
764 
765 /*
766  * Hook disconnection. Note that we do *not* shutdown when all
767  * hooks have been disconnected.
768  */
769 static int
770 ng_iface_disconnect(hook_p hook)
771 {
772 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
773 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
774 
775 	if (iffam == NULL)
776 		panic("%s", __func__);
777 	PRIV_WLOCK(priv);
778 	*get_hook_from_iffam(priv, iffam) = NULL;
779 	PRIV_WUNLOCK(priv);
780 	return (0);
781 }
782 
783 /*
784  * Handle loading and unloading for this node type.
785  */
786 static int
787 ng_iface_mod_event(module_t mod, int event, void *data)
788 {
789 	int error = 0;
790 
791 	switch (event) {
792 	case MOD_LOAD:
793 	case MOD_UNLOAD:
794 		break;
795 	default:
796 		error = EOPNOTSUPP;
797 		break;
798 	}
799 	return (error);
800 }
801 
802 static void
803 vnet_ng_iface_init(const void *unused)
804 {
805 
806 	V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
807 }
808 VNET_SYSINIT(vnet_ng_iface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
809     vnet_ng_iface_init, NULL);
810 
811 static void
812 vnet_ng_iface_uninit(const void *unused)
813 {
814 
815 	delete_unrhdr(V_ng_iface_unit);
816 }
817 VNET_SYSUNINIT(vnet_ng_iface_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
818     vnet_ng_iface_uninit, NULL);
819