xref: /freebsd/sys/netgraph/ng_iface.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
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 #include <netgraph/ng_cisco.h>
87 
88 #ifdef NG_SEPARATE_MALLOC
89 static MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node");
90 #else
91 #define M_NETGRAPH_IFACE M_NETGRAPH
92 #endif
93 
94 /* This struct describes one address family */
95 struct iffam {
96 	sa_family_t	family;		/* Address family */
97 	const char	*hookname;	/* Name for hook */
98 };
99 typedef const struct iffam *iffam_p;
100 
101 /* List of address families supported by our interface */
102 const static struct iffam gFamilies[] = {
103 	{ AF_INET,	NG_IFACE_HOOK_INET	},
104 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
105 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
106 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
107 };
108 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
109 
110 /* Node private data */
111 struct ng_iface_private {
112 	struct	ifnet *ifp;		/* Our interface */
113 	int	unit;			/* Interface unit number */
114 	node_p	node;			/* Our netgraph node */
115 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
116 };
117 typedef struct ng_iface_private *priv_p;
118 
119 /* Interface methods */
120 static void	ng_iface_start(struct ifnet *ifp);
121 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
122 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
123     			const struct sockaddr *dst, struct route *ro);
124 static void	ng_iface_bpftap(struct ifnet *ifp,
125 			struct mbuf *m, sa_family_t family);
126 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
127 			sa_family_t sa);
128 #ifdef DEBUG
129 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
130 #endif
131 
132 /* Netgraph methods */
133 static int		ng_iface_mod_event(module_t, int, void *);
134 static ng_constructor_t	ng_iface_constructor;
135 static ng_rcvmsg_t	ng_iface_rcvmsg;
136 static ng_shutdown_t	ng_iface_shutdown;
137 static ng_newhook_t	ng_iface_newhook;
138 static ng_rcvdata_t	ng_iface_rcvdata;
139 static ng_disconnect_t	ng_iface_disconnect;
140 
141 /* Helper stuff */
142 static iffam_p	get_iffam_from_af(sa_family_t family);
143 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
144 static iffam_p	get_iffam_from_name(const char *name);
145 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
146 
147 /* Parse type for struct ng_cisco_ipaddr */
148 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
149 	= NG_CISCO_IPADDR_TYPE_INFO;
150 static const struct ng_parse_type ng_cisco_ipaddr_type = {
151 	&ng_parse_struct_type,
152 	&ng_cisco_ipaddr_type_fields
153 };
154 
155 /* List of commands and how to convert arguments to/from ASCII */
156 static const struct ng_cmdlist ng_iface_cmds[] = {
157 	{
158 	  NGM_IFACE_COOKIE,
159 	  NGM_IFACE_GET_IFNAME,
160 	  "getifname",
161 	  NULL,
162 	  &ng_parse_string_type
163 	},
164 	{
165 	  NGM_IFACE_COOKIE,
166 	  NGM_IFACE_POINT2POINT,
167 	  "point2point",
168 	  NULL,
169 	  NULL
170 	},
171 	{
172 	  NGM_IFACE_COOKIE,
173 	  NGM_IFACE_BROADCAST,
174 	  "broadcast",
175 	  NULL,
176 	  NULL
177 	},
178 	{
179 	  NGM_CISCO_COOKIE,
180 	  NGM_CISCO_GET_IPADDR,
181 	  "getipaddr",
182 	  NULL,
183 	  &ng_cisco_ipaddr_type
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 static VNET_DEFINE(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 	struct m_tag *mtag;
356 	uint32_t af;
357 	int error;
358 
359 	/* Check interface flags */
360 	if (!((ifp->if_flags & IFF_UP) &&
361 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
362 		m_freem(m);
363 		return (ENETDOWN);
364 	}
365 
366 	/* Protect from deadly infinite recursion. */
367 	mtag = NULL;
368 	while ((mtag = m_tag_locate(m, MTAG_NGIF, MTAG_NGIF_CALLED, mtag))) {
369 		if (*(struct ifnet **)(mtag + 1) == ifp) {
370 			log(LOG_NOTICE, "Loop detected on %s\n", ifp->if_xname);
371 			m_freem(m);
372 			return (EDEADLK);
373 		}
374 	}
375 	mtag = m_tag_alloc(MTAG_NGIF, MTAG_NGIF_CALLED, sizeof(struct ifnet *),
376 	    M_NOWAIT);
377 	if (mtag == NULL) {
378 		m_freem(m);
379 		return (ENOMEM);
380 	}
381 	*(struct ifnet **)(mtag + 1) = ifp;
382 	m_tag_prepend(m, mtag);
383 
384 	/* BPF writes need to be handled specially. */
385 	if (dst->sa_family == AF_UNSPEC)
386 		bcopy(dst->sa_data, &af, sizeof(af));
387 	else
388 		af = dst->sa_family;
389 
390 	/* Berkeley packet filter */
391 	ng_iface_bpftap(ifp, m, af);
392 
393 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
394 		M_PREPEND(m, sizeof(sa_family_t), M_NOWAIT);
395 		if (m == NULL) {
396 			IFQ_LOCK(&ifp->if_snd);
397 			IFQ_INC_DROPS(&ifp->if_snd);
398 			IFQ_UNLOCK(&ifp->if_snd);
399 			ifp->if_oerrors++;
400 			return (ENOBUFS);
401 		}
402 		*(sa_family_t *)m->m_data = af;
403 		error = (ifp->if_transmit)(ifp, m);
404 	} else
405 		error = ng_iface_send(ifp, m, af);
406 
407 	return (error);
408 }
409 
410 /*
411  * Start method is used only when ALTQ is enabled.
412  */
413 static void
414 ng_iface_start(struct ifnet *ifp)
415 {
416 	struct mbuf *m;
417 	sa_family_t sa;
418 
419 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
420 
421 	for(;;) {
422 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
423 		if (m == NULL)
424 			break;
425 		sa = *mtod(m, sa_family_t *);
426 		m_adj(m, sizeof(sa_family_t));
427 		ng_iface_send(ifp, m, sa);
428 	}
429 }
430 
431 /*
432  * Flash a packet by the BPF (requires prepending 4 byte AF header)
433  * Note the phoney mbuf; this is OK because BPF treats it read-only.
434  */
435 static void
436 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
437 {
438 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
439 	if (bpf_peers_present(ifp->if_bpf)) {
440 		int32_t family4 = (int32_t)family;
441 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
442 	}
443 }
444 
445 /*
446  * This routine does actual delivery of the packet into the
447  * netgraph(4). It is called from ng_iface_start() and
448  * ng_iface_output().
449  */
450 static int
451 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
452 {
453 	const priv_p priv = (priv_p) ifp->if_softc;
454 	const iffam_p iffam = get_iffam_from_af(sa);
455 	int error;
456 	int len;
457 
458 	/* Check address family to determine hook (if known) */
459 	if (iffam == NULL) {
460 		m_freem(m);
461 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
462 		return (EAFNOSUPPORT);
463 	}
464 
465 	/* Copy length before the mbuf gets invalidated. */
466 	len = m->m_pkthdr.len;
467 
468 	/* Send packet. If hook is not connected, mbuf will get freed. */
469 	NG_OUTBOUND_THREAD_REF();
470 	NG_SEND_DATA_ONLY(error, *get_hook_from_iffam(priv, iffam), m);
471 	NG_OUTBOUND_THREAD_UNREF();
472 
473 	/* Update stats. */
474 	if (error == 0) {
475 		ifp->if_obytes += len;
476 		ifp->if_opackets++;
477 	}
478 
479 	return (error);
480 }
481 
482 #ifdef DEBUG
483 /*
484  * Display an ioctl to the virtual interface
485  */
486 
487 static void
488 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
489 {
490 	char   *str;
491 
492 	switch (command & IOC_DIRMASK) {
493 	case IOC_VOID:
494 		str = "IO";
495 		break;
496 	case IOC_OUT:
497 		str = "IOR";
498 		break;
499 	case IOC_IN:
500 		str = "IOW";
501 		break;
502 	case IOC_INOUT:
503 		str = "IORW";
504 		break;
505 	default:
506 		str = "IO??";
507 	}
508 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
509 	       ifp->if_xname,
510 	       str,
511 	       IOCGROUP(command),
512 	       command & 0xff,
513 	       IOCPARM_LEN(command));
514 }
515 #endif /* DEBUG */
516 
517 /************************************************************************
518 			NETGRAPH NODE STUFF
519  ************************************************************************/
520 
521 /*
522  * Constructor for a node
523  */
524 static int
525 ng_iface_constructor(node_p node)
526 {
527 	struct ifnet *ifp;
528 	priv_p priv;
529 
530 	/* Allocate node and interface private structures */
531 	priv = malloc(sizeof(*priv), M_NETGRAPH_IFACE, M_WAITOK | M_ZERO);
532 	ifp = if_alloc(IFT_PROPVIRTUAL);
533 	if (ifp == NULL) {
534 		free(priv, M_NETGRAPH_IFACE);
535 		return (ENOMEM);
536 	}
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 	hook_p *hookptr;
585 
586 	if (iffam == NULL)
587 		return (EPFNOSUPPORT);
588 	hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
589 	if (*hookptr != NULL)
590 		return (EISCONN);
591 	*hookptr = hook;
592 	NG_HOOK_HI_STACK(hook);
593 	NG_HOOK_SET_TO_INBOUND(hook);
594 	return (0);
595 }
596 
597 /*
598  * Receive a control message
599  */
600 static int
601 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
602 {
603 	const priv_p priv = NG_NODE_PRIVATE(node);
604 	struct ifnet *const ifp = priv->ifp;
605 	struct ng_mesg *resp = NULL;
606 	int error = 0;
607 	struct ng_mesg *msg;
608 
609 	NGI_GET_MSG(item, msg);
610 	switch (msg->header.typecookie) {
611 	case NGM_IFACE_COOKIE:
612 		switch (msg->header.cmd) {
613 		case NGM_IFACE_GET_IFNAME:
614 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
615 			if (resp == NULL) {
616 				error = ENOMEM;
617 				break;
618 			}
619 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
620 			break;
621 
622 		case NGM_IFACE_POINT2POINT:
623 		case NGM_IFACE_BROADCAST:
624 		    {
625 
626 			/* Deny request if interface is UP */
627 			if ((ifp->if_flags & IFF_UP) != 0)
628 				return (EBUSY);
629 
630 			/* Change flags */
631 			switch (msg->header.cmd) {
632 			case NGM_IFACE_POINT2POINT:
633 				ifp->if_flags |= IFF_POINTOPOINT;
634 				ifp->if_flags &= ~IFF_BROADCAST;
635 				break;
636 			case NGM_IFACE_BROADCAST:
637 				ifp->if_flags &= ~IFF_POINTOPOINT;
638 				ifp->if_flags |= IFF_BROADCAST;
639 				break;
640 			}
641 			break;
642 		    }
643 
644 		case NGM_IFACE_GET_IFINDEX:
645 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
646 			if (resp == NULL) {
647 				error = ENOMEM;
648 				break;
649 			}
650 			*((uint32_t *)resp->data) = priv->ifp->if_index;
651 			break;
652 
653 		default:
654 			error = EINVAL;
655 			break;
656 		}
657 		break;
658 	case NGM_CISCO_COOKIE:
659 		switch (msg->header.cmd) {
660 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
661 		    {
662 			struct ifaddr *ifa;
663 
664 			/* Return the first configured IP address */
665 			if_addr_rlock(ifp);
666 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
667 				struct ng_cisco_ipaddr *ips;
668 
669 				if (ifa->ifa_addr->sa_family != AF_INET)
670 					continue;
671 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
672 				if (resp == NULL) {
673 					error = ENOMEM;
674 					break;
675 				}
676 				ips = (struct ng_cisco_ipaddr *)resp->data;
677 				ips->ipaddr = ((struct sockaddr_in *)
678 						ifa->ifa_addr)->sin_addr;
679 				ips->netmask = ((struct sockaddr_in *)
680 						ifa->ifa_netmask)->sin_addr;
681 				break;
682 			}
683 			if_addr_runlock(ifp);
684 
685 			/* No IP addresses on this interface? */
686 			if (ifa == NULL)
687 				error = EADDRNOTAVAIL;
688 			break;
689 		    }
690 		default:
691 			error = EINVAL;
692 			break;
693 		}
694 		break;
695 	case NGM_FLOW_COOKIE:
696 		switch (msg->header.cmd) {
697 		case NGM_LINK_IS_UP:
698 			ifp->if_drv_flags |= IFF_DRV_RUNNING;
699 			break;
700 		case NGM_LINK_IS_DOWN:
701 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
702 			break;
703 		default:
704 			break;
705 		}
706 		break;
707 	default:
708 		error = EINVAL;
709 		break;
710 	}
711 	NG_RESPOND_MSG(error, node, item, resp);
712 	NG_FREE_MSG(msg);
713 	return (error);
714 }
715 
716 /*
717  * Recive data from a hook. Pass the packet to the correct input routine.
718  */
719 static int
720 ng_iface_rcvdata(hook_p hook, item_p item)
721 {
722 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
723 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
724 	struct ifnet *const ifp = priv->ifp;
725 	struct mbuf *m;
726 	int isr;
727 
728 	NGI_GET_M(item, m);
729 	NG_FREE_ITEM(item);
730 	/* Sanity checks */
731 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
732 	M_ASSERTPKTHDR(m);
733 	if ((ifp->if_flags & IFF_UP) == 0) {
734 		NG_FREE_M(m);
735 		return (ENETDOWN);
736 	}
737 
738 	/* Update interface stats */
739 	ifp->if_ipackets++;
740 	ifp->if_ibytes += m->m_pkthdr.len;
741 
742 	/* Note receiving interface */
743 	m->m_pkthdr.rcvif = ifp;
744 
745 	/* Berkeley packet filter */
746 	ng_iface_bpftap(ifp, m, iffam->family);
747 
748 	/* Send packet */
749 	switch (iffam->family) {
750 #ifdef INET
751 	case AF_INET:
752 		isr = NETISR_IP;
753 		break;
754 #endif
755 #ifdef INET6
756 	case AF_INET6:
757 		isr = NETISR_IPV6;
758 		break;
759 #endif
760 	default:
761 		m_freem(m);
762 		return (EAFNOSUPPORT);
763 	}
764 	if (harvest.point_to_point)
765 		random_harvest(&(m->m_data), 12, 2, RANDOM_NET_NG);
766 	M_SETFIB(m, ifp->if_fib);
767 	netisr_dispatch(isr, m);
768 	return (0);
769 }
770 
771 /*
772  * Shutdown and remove the node and its associated interface.
773  */
774 static int
775 ng_iface_shutdown(node_p node)
776 {
777 	const priv_p priv = NG_NODE_PRIVATE(node);
778 
779 	/*
780 	 * The ifnet may be in a different vnet than the netgraph node,
781 	 * hence we have to change the current vnet context here.
782 	 */
783 	CURVNET_SET_QUIET(priv->ifp->if_vnet);
784 	bpfdetach(priv->ifp);
785 	if_detach(priv->ifp);
786 	if_free(priv->ifp);
787 	CURVNET_RESTORE();
788 	priv->ifp = NULL;
789 	free_unr(V_ng_iface_unit, priv->unit);
790 	free(priv, M_NETGRAPH_IFACE);
791 	NG_NODE_SET_PRIVATE(node, NULL);
792 	NG_NODE_UNREF(node);
793 	return (0);
794 }
795 
796 /*
797  * Hook disconnection. Note that we do *not* shutdown when all
798  * hooks have been disconnected.
799  */
800 static int
801 ng_iface_disconnect(hook_p hook)
802 {
803 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
804 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
805 
806 	if (iffam == NULL)
807 		panic("%s", __func__);
808 	*get_hook_from_iffam(priv, iffam) = NULL;
809 	return (0);
810 }
811 
812 /*
813  * Handle loading and unloading for this node type.
814  */
815 static int
816 ng_iface_mod_event(module_t mod, int event, void *data)
817 {
818 	int error = 0;
819 
820 	switch (event) {
821 	case MOD_LOAD:
822 	case MOD_UNLOAD:
823 		break;
824 	default:
825 		error = EOPNOTSUPP;
826 		break;
827 	}
828 	return (error);
829 }
830 
831 static void
832 vnet_ng_iface_init(const void *unused)
833 {
834 
835 	V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
836 }
837 VNET_SYSINIT(vnet_ng_iface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
838     vnet_ng_iface_init, NULL);
839 
840 static void
841 vnet_ng_iface_uninit(const void *unused)
842 {
843 
844 	delete_unrhdr(V_ng_iface_unit);
845 }
846 VNET_SYSUNINIT(vnet_ng_iface_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY,
847     vnet_ng_iface_uninit, NULL);
848