xref: /freebsd/sys/netgraph/ng_iface.c (revision dda5b39711dab90ae1c5624bdd6ff7453177df31)
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_atalk.h"
56 #include "opt_inet.h"
57 #include "opt_inet6.h"
58 
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/errno.h>
62 #include <sys/kernel.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/sockio.h>
69 #include <sys/socket.h>
70 #include <sys/syslog.h>
71 #include <sys/libkern.h>
72 
73 #include <net/if.h>
74 #include <net/if_var.h>
75 #include <net/if_types.h>
76 #include <net/bpf.h>
77 #include <net/netisr.h>
78 #include <net/route.h>
79 #include <net/vnet.h>
80 
81 #include <netinet/in.h>
82 
83 #include <netgraph/ng_message.h>
84 #include <netgraph/netgraph.h>
85 #include <netgraph/ng_parse.h>
86 #include <netgraph/ng_iface.h>
87 #include <netgraph/ng_cisco.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_APPLETALK,	NG_IFACE_HOOK_ATALK	},
107 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
108 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
109 };
110 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
111 
112 /* Node private data */
113 struct ng_iface_private {
114 	struct	ifnet *ifp;		/* Our interface */
115 	int	unit;			/* Interface unit number */
116 	node_p	node;			/* Our netgraph node */
117 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
118 };
119 typedef struct ng_iface_private *priv_p;
120 
121 /* Interface methods */
122 static void	ng_iface_start(struct ifnet *ifp);
123 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
124 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
125     			const struct sockaddr *dst, struct route *ro);
126 static void	ng_iface_bpftap(struct ifnet *ifp,
127 			struct mbuf *m, sa_family_t family);
128 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
129 			sa_family_t sa);
130 #ifdef DEBUG
131 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
132 #endif
133 
134 /* Netgraph methods */
135 static int		ng_iface_mod_event(module_t, int, void *);
136 static ng_constructor_t	ng_iface_constructor;
137 static ng_rcvmsg_t	ng_iface_rcvmsg;
138 static ng_shutdown_t	ng_iface_shutdown;
139 static ng_newhook_t	ng_iface_newhook;
140 static ng_rcvdata_t	ng_iface_rcvdata;
141 static ng_disconnect_t	ng_iface_disconnect;
142 
143 /* Helper stuff */
144 static iffam_p	get_iffam_from_af(sa_family_t family);
145 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
146 static iffam_p	get_iffam_from_name(const char *name);
147 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
148 
149 /* Parse type for struct ng_cisco_ipaddr */
150 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
151 	= NG_CISCO_IPADDR_TYPE_INFO;
152 static const struct ng_parse_type ng_cisco_ipaddr_type = {
153 	&ng_parse_struct_type,
154 	&ng_cisco_ipaddr_type_fields
155 };
156 
157 /* List of commands and how to convert arguments to/from ASCII */
158 static const struct ng_cmdlist ng_iface_cmds[] = {
159 	{
160 	  NGM_IFACE_COOKIE,
161 	  NGM_IFACE_GET_IFNAME,
162 	  "getifname",
163 	  NULL,
164 	  &ng_parse_string_type
165 	},
166 	{
167 	  NGM_IFACE_COOKIE,
168 	  NGM_IFACE_POINT2POINT,
169 	  "point2point",
170 	  NULL,
171 	  NULL
172 	},
173 	{
174 	  NGM_IFACE_COOKIE,
175 	  NGM_IFACE_BROADCAST,
176 	  "broadcast",
177 	  NULL,
178 	  NULL
179 	},
180 	{
181 	  NGM_CISCO_COOKIE,
182 	  NGM_CISCO_GET_IPADDR,
183 	  "getipaddr",
184 	  NULL,
185 	  &ng_cisco_ipaddr_type
186 	},
187 	{
188 	  NGM_IFACE_COOKIE,
189 	  NGM_IFACE_GET_IFINDEX,
190 	  "getifindex",
191 	  NULL,
192 	  &ng_parse_uint32_type
193 	},
194 	{ 0 }
195 };
196 
197 /* Node type descriptor */
198 static struct ng_type typestruct = {
199 	.version =	NG_ABI_VERSION,
200 	.name =		NG_IFACE_NODE_TYPE,
201 	.mod_event =	ng_iface_mod_event,
202 	.constructor =	ng_iface_constructor,
203 	.rcvmsg =	ng_iface_rcvmsg,
204 	.shutdown =	ng_iface_shutdown,
205 	.newhook =	ng_iface_newhook,
206 	.rcvdata =	ng_iface_rcvdata,
207 	.disconnect =	ng_iface_disconnect,
208 	.cmdlist =	ng_iface_cmds,
209 };
210 NETGRAPH_INIT(iface, &typestruct);
211 
212 static VNET_DEFINE(struct unrhdr *, ng_iface_unit);
213 #define	V_ng_iface_unit			VNET(ng_iface_unit)
214 
215 /************************************************************************
216 			HELPER STUFF
217  ************************************************************************/
218 
219 /*
220  * Get the family descriptor from the family ID
221  */
222 static __inline iffam_p
223 get_iffam_from_af(sa_family_t family)
224 {
225 	iffam_p iffam;
226 	int k;
227 
228 	for (k = 0; k < NUM_FAMILIES; k++) {
229 		iffam = &gFamilies[k];
230 		if (iffam->family == family)
231 			return (iffam);
232 	}
233 	return (NULL);
234 }
235 
236 /*
237  * Get the family descriptor from the hook
238  */
239 static __inline iffam_p
240 get_iffam_from_hook(priv_p priv, hook_p hook)
241 {
242 	int k;
243 
244 	for (k = 0; k < NUM_FAMILIES; k++)
245 		if (priv->hooks[k] == hook)
246 			return (&gFamilies[k]);
247 	return (NULL);
248 }
249 
250 /*
251  * Get the hook from the iffam descriptor
252  */
253 
254 static __inline hook_p *
255 get_hook_from_iffam(priv_p priv, iffam_p iffam)
256 {
257 	return (&priv->hooks[iffam - gFamilies]);
258 }
259 
260 /*
261  * Get the iffam descriptor from the name
262  */
263 static __inline iffam_p
264 get_iffam_from_name(const char *name)
265 {
266 	iffam_p iffam;
267 	int k;
268 
269 	for (k = 0; k < NUM_FAMILIES; k++) {
270 		iffam = &gFamilies[k];
271 		if (!strcmp(iffam->hookname, name))
272 			return (iffam);
273 	}
274 	return (NULL);
275 }
276 
277 /************************************************************************
278 			INTERFACE STUFF
279  ************************************************************************/
280 
281 /*
282  * Process an ioctl for the virtual interface
283  */
284 static int
285 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
286 {
287 	struct ifreq *const ifr = (struct ifreq *) data;
288 	int error = 0;
289 
290 #ifdef DEBUG
291 	ng_iface_print_ioctl(ifp, command, data);
292 #endif
293 	switch (command) {
294 
295 	/* These two are mostly handled at a higher layer */
296 	case SIOCSIFADDR:
297 		ifp->if_flags |= IFF_UP;
298 		ifp->if_drv_flags |= IFF_DRV_RUNNING;
299 		ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
300 		break;
301 	case SIOCGIFADDR:
302 		break;
303 
304 	/* Set flags */
305 	case SIOCSIFFLAGS:
306 		/*
307 		 * If the interface is marked up and stopped, then start it.
308 		 * If it is marked down and running, then stop it.
309 		 */
310 		if (ifr->ifr_flags & IFF_UP) {
311 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
312 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
313 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
314 			}
315 		} else {
316 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
317 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
318 				    IFF_DRV_OACTIVE);
319 		}
320 		break;
321 
322 	/* Set the interface MTU */
323 	case SIOCSIFMTU:
324 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
325 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
326 			error = EINVAL;
327 		else
328 			ifp->if_mtu = ifr->ifr_mtu;
329 		break;
330 
331 	/* Stuff that's not supported */
332 	case SIOCADDMULTI:
333 	case SIOCDELMULTI:
334 		error = 0;
335 		break;
336 	case SIOCSIFPHYS:
337 		error = EOPNOTSUPP;
338 		break;
339 
340 	default:
341 		error = EINVAL;
342 		break;
343 	}
344 	return (error);
345 }
346 
347 /*
348  * This routine is called to deliver a packet out the interface.
349  * We simply look at the address family and relay the packet to
350  * the corresponding hook, if it exists and is connected.
351  */
352 
353 static int
354 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
355 	const struct sockaddr *dst, struct route *ro)
356 {
357 	struct m_tag *mtag;
358 	uint32_t af;
359 	int error;
360 
361 	/* Check interface flags */
362 	if (!((ifp->if_flags & IFF_UP) &&
363 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
364 		m_freem(m);
365 		return (ENETDOWN);
366 	}
367 
368 	/* Protect from deadly infinite recursion. */
369 	mtag = NULL;
370 	while ((mtag = m_tag_locate(m, MTAG_NGIF, MTAG_NGIF_CALLED, mtag))) {
371 		if (*(struct ifnet **)(mtag + 1) == ifp) {
372 			log(LOG_NOTICE, "Loop detected on %s\n", ifp->if_xname);
373 			m_freem(m);
374 			return (EDEADLK);
375 		}
376 	}
377 	mtag = m_tag_alloc(MTAG_NGIF, MTAG_NGIF_CALLED, sizeof(struct ifnet *),
378 	    M_NOWAIT);
379 	if (mtag == NULL) {
380 		m_freem(m);
381 		return (ENOMEM);
382 	}
383 	*(struct ifnet **)(mtag + 1) = ifp;
384 	m_tag_prepend(m, mtag);
385 
386 	/* BPF writes need to be handled specially. */
387 	if (dst->sa_family == AF_UNSPEC)
388 		bcopy(dst->sa_data, &af, sizeof(af));
389 	else
390 		af = dst->sa_family;
391 
392 	/* Berkeley packet filter */
393 	ng_iface_bpftap(ifp, m, af);
394 
395 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
396 		M_PREPEND(m, sizeof(sa_family_t), M_NOWAIT);
397 		if (m == NULL) {
398 			IFQ_LOCK(&ifp->if_snd);
399 			IFQ_INC_DROPS(&ifp->if_snd);
400 			IFQ_UNLOCK(&ifp->if_snd);
401 			ifp->if_oerrors++;
402 			return (ENOBUFS);
403 		}
404 		*(sa_family_t *)m->m_data = af;
405 		error = (ifp->if_transmit)(ifp, m);
406 	} else
407 		error = ng_iface_send(ifp, m, af);
408 
409 	return (error);
410 }
411 
412 /*
413  * Start method is used only when ALTQ is enabled.
414  */
415 static void
416 ng_iface_start(struct ifnet *ifp)
417 {
418 	struct mbuf *m;
419 	sa_family_t sa;
420 
421 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
422 
423 	for(;;) {
424 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
425 		if (m == NULL)
426 			break;
427 		sa = *mtod(m, sa_family_t *);
428 		m_adj(m, sizeof(sa_family_t));
429 		ng_iface_send(ifp, m, sa);
430 	}
431 }
432 
433 /*
434  * Flash a packet by the BPF (requires prepending 4 byte AF header)
435  * Note the phoney mbuf; this is OK because BPF treats it read-only.
436  */
437 static void
438 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
439 {
440 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
441 	if (bpf_peers_present(ifp->if_bpf)) {
442 		int32_t family4 = (int32_t)family;
443 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
444 	}
445 }
446 
447 /*
448  * This routine does actual delivery of the packet into the
449  * netgraph(4). It is called from ng_iface_start() and
450  * ng_iface_output().
451  */
452 static int
453 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
454 {
455 	const priv_p priv = (priv_p) ifp->if_softc;
456 	const iffam_p iffam = get_iffam_from_af(sa);
457 	int error;
458 	int len;
459 
460 	/* Check address family to determine hook (if known) */
461 	if (iffam == NULL) {
462 		m_freem(m);
463 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
464 		return (EAFNOSUPPORT);
465 	}
466 
467 	/* Copy length before the mbuf gets invalidated. */
468 	len = m->m_pkthdr.len;
469 
470 	/* Send packet. If hook is not connected, mbuf will get freed. */
471 	NG_OUTBOUND_THREAD_REF();
472 	NG_SEND_DATA_ONLY(error, *get_hook_from_iffam(priv, iffam), m);
473 	NG_OUTBOUND_THREAD_UNREF();
474 
475 	/* Update stats. */
476 	if (error == 0) {
477 		ifp->if_obytes += len;
478 		ifp->if_opackets++;
479 	}
480 
481 	return (error);
482 }
483 
484 #ifdef DEBUG
485 /*
486  * Display an ioctl to the virtual interface
487  */
488 
489 static void
490 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
491 {
492 	char   *str;
493 
494 	switch (command & IOC_DIRMASK) {
495 	case IOC_VOID:
496 		str = "IO";
497 		break;
498 	case IOC_OUT:
499 		str = "IOR";
500 		break;
501 	case IOC_IN:
502 		str = "IOW";
503 		break;
504 	case IOC_INOUT:
505 		str = "IORW";
506 		break;
507 	default:
508 		str = "IO??";
509 	}
510 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
511 	       ifp->if_xname,
512 	       str,
513 	       IOCGROUP(command),
514 	       command & 0xff,
515 	       IOCPARM_LEN(command));
516 }
517 #endif /* DEBUG */
518 
519 /************************************************************************
520 			NETGRAPH NODE STUFF
521  ************************************************************************/
522 
523 /*
524  * Constructor for a node
525  */
526 static int
527 ng_iface_constructor(node_p node)
528 {
529 	struct ifnet *ifp;
530 	priv_p priv;
531 
532 	/* Allocate node and interface private structures */
533 	priv = malloc(sizeof(*priv), M_NETGRAPH_IFACE, M_WAITOK | M_ZERO);
534 	ifp = if_alloc(IFT_PROPVIRTUAL);
535 	if (ifp == NULL) {
536 		free(priv, M_NETGRAPH_IFACE);
537 		return (ENOMEM);
538 	}
539 
540 	/* Link them together */
541 	ifp->if_softc = priv;
542 	priv->ifp = ifp;
543 
544 	/* Get an interface unit number */
545 	priv->unit = alloc_unr(V_ng_iface_unit);
546 
547 	/* Link together node and private info */
548 	NG_NODE_SET_PRIVATE(node, priv);
549 	priv->node = node;
550 
551 	/* Initialize interface structure */
552 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
553 	ifp->if_output = ng_iface_output;
554 	ifp->if_start = ng_iface_start;
555 	ifp->if_ioctl = ng_iface_ioctl;
556 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
557 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
558 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
559 	ifp->if_addrlen = 0;			/* XXX */
560 	ifp->if_hdrlen = 0;			/* XXX */
561 	ifp->if_baudrate = 64000;		/* XXX */
562 	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
563 	ifp->if_snd.ifq_drv_maxlen = ifqmaxlen;
564 	IFQ_SET_READY(&ifp->if_snd);
565 
566 	/* Give this node the same name as the interface (if possible) */
567 	if (ng_name_node(node, ifp->if_xname) != 0)
568 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
569 		    ifp->if_xname);
570 
571 	/* Attach the interface */
572 	if_attach(ifp);
573 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
574 
575 	/* Done */
576 	return (0);
577 }
578 
579 /*
580  * Give our ok for a hook to be added
581  */
582 static int
583 ng_iface_newhook(node_p node, hook_p hook, const char *name)
584 {
585 	const iffam_p iffam = get_iffam_from_name(name);
586 	hook_p *hookptr;
587 
588 	if (iffam == NULL)
589 		return (EPFNOSUPPORT);
590 	hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
591 	if (*hookptr != NULL)
592 		return (EISCONN);
593 	*hookptr = hook;
594 	NG_HOOK_HI_STACK(hook);
595 	NG_HOOK_SET_TO_INBOUND(hook);
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 
628 			/* Deny request if interface is UP */
629 			if ((ifp->if_flags & IFF_UP) != 0)
630 				return (EBUSY);
631 
632 			/* Change flags */
633 			switch (msg->header.cmd) {
634 			case NGM_IFACE_POINT2POINT:
635 				ifp->if_flags |= IFF_POINTOPOINT;
636 				ifp->if_flags &= ~IFF_BROADCAST;
637 				break;
638 			case NGM_IFACE_BROADCAST:
639 				ifp->if_flags &= ~IFF_POINTOPOINT;
640 				ifp->if_flags |= IFF_BROADCAST;
641 				break;
642 			}
643 			break;
644 		    }
645 
646 		case NGM_IFACE_GET_IFINDEX:
647 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
648 			if (resp == NULL) {
649 				error = ENOMEM;
650 				break;
651 			}
652 			*((uint32_t *)resp->data) = priv->ifp->if_index;
653 			break;
654 
655 		default:
656 			error = EINVAL;
657 			break;
658 		}
659 		break;
660 	case NGM_CISCO_COOKIE:
661 		switch (msg->header.cmd) {
662 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
663 		    {
664 			struct ifaddr *ifa;
665 
666 			/* Return the first configured IP address */
667 			if_addr_rlock(ifp);
668 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
669 				struct ng_cisco_ipaddr *ips;
670 
671 				if (ifa->ifa_addr->sa_family != AF_INET)
672 					continue;
673 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
674 				if (resp == NULL) {
675 					error = ENOMEM;
676 					break;
677 				}
678 				ips = (struct ng_cisco_ipaddr *)resp->data;
679 				ips->ipaddr = ((struct sockaddr_in *)
680 						ifa->ifa_addr)->sin_addr;
681 				ips->netmask = ((struct sockaddr_in *)
682 						ifa->ifa_netmask)->sin_addr;
683 				break;
684 			}
685 			if_addr_runlock(ifp);
686 
687 			/* No IP addresses on this interface? */
688 			if (ifa == NULL)
689 				error = EADDRNOTAVAIL;
690 			break;
691 		    }
692 		default:
693 			error = EINVAL;
694 			break;
695 		}
696 		break;
697 	case NGM_FLOW_COOKIE:
698 		switch (msg->header.cmd) {
699 		case NGM_LINK_IS_UP:
700 			ifp->if_drv_flags |= IFF_DRV_RUNNING;
701 			break;
702 		case NGM_LINK_IS_DOWN:
703 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
704 			break;
705 		default:
706 			break;
707 		}
708 		break;
709 	default:
710 		error = EINVAL;
711 		break;
712 	}
713 	NG_RESPOND_MSG(error, node, item, resp);
714 	NG_FREE_MSG(msg);
715 	return (error);
716 }
717 
718 /*
719  * Recive data from a hook. Pass the packet to the correct input routine.
720  */
721 static int
722 ng_iface_rcvdata(hook_p hook, item_p item)
723 {
724 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
725 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
726 	struct ifnet *const ifp = priv->ifp;
727 	struct mbuf *m;
728 	int isr;
729 
730 	NGI_GET_M(item, m);
731 	NG_FREE_ITEM(item);
732 	/* Sanity checks */
733 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
734 	M_ASSERTPKTHDR(m);
735 	if ((ifp->if_flags & IFF_UP) == 0) {
736 		NG_FREE_M(m);
737 		return (ENETDOWN);
738 	}
739 
740 	/* Update interface stats */
741 	ifp->if_ipackets++;
742 	ifp->if_ibytes += m->m_pkthdr.len;
743 
744 	/* Note receiving interface */
745 	m->m_pkthdr.rcvif = ifp;
746 
747 	/* Berkeley packet filter */
748 	ng_iface_bpftap(ifp, m, iffam->family);
749 
750 	/* Send packet */
751 	switch (iffam->family) {
752 #ifdef INET
753 	case AF_INET:
754 		isr = NETISR_IP;
755 		break;
756 #endif
757 #ifdef INET6
758 	case AF_INET6:
759 		isr = NETISR_IPV6;
760 		break;
761 #endif
762 #ifdef NETATALK
763 	case AF_APPLETALK:
764 		isr = NETISR_ATALK2;
765 		break;
766 #endif
767 	default:
768 		m_freem(m);
769 		return (EAFNOSUPPORT);
770 	}
771 	if (harvest.point_to_point)
772 		random_harvest(&(m->m_data), 12, 2, RANDOM_NET_NG);
773 	M_SETFIB(m, ifp->if_fib);
774 	netisr_dispatch(isr, m);
775 	return (0);
776 }
777 
778 /*
779  * Shutdown and remove the node and its associated interface.
780  */
781 static int
782 ng_iface_shutdown(node_p node)
783 {
784 	const priv_p priv = NG_NODE_PRIVATE(node);
785 
786 	/*
787 	 * The ifnet may be in a different vnet than the netgraph node,
788 	 * hence we have to change the current vnet context here.
789 	 */
790 	CURVNET_SET_QUIET(priv->ifp->if_vnet);
791 	bpfdetach(priv->ifp);
792 	if_detach(priv->ifp);
793 	if_free(priv->ifp);
794 	CURVNET_RESTORE();
795 	priv->ifp = NULL;
796 	free_unr(V_ng_iface_unit, priv->unit);
797 	free(priv, M_NETGRAPH_IFACE);
798 	NG_NODE_SET_PRIVATE(node, NULL);
799 	NG_NODE_UNREF(node);
800 	return (0);
801 }
802 
803 /*
804  * Hook disconnection. Note that we do *not* shutdown when all
805  * hooks have been disconnected.
806  */
807 static int
808 ng_iface_disconnect(hook_p hook)
809 {
810 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
811 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
812 
813 	if (iffam == NULL)
814 		panic("%s", __func__);
815 	*get_hook_from_iffam(priv, iffam) = NULL;
816 	return (0);
817 }
818 
819 /*
820  * Handle loading and unloading for this node type.
821  */
822 static int
823 ng_iface_mod_event(module_t mod, int event, void *data)
824 {
825 	int error = 0;
826 
827 	switch (event) {
828 	case MOD_LOAD:
829 	case MOD_UNLOAD:
830 		break;
831 	default:
832 		error = EOPNOTSUPP;
833 		break;
834 	}
835 	return (error);
836 }
837 
838 static void
839 vnet_ng_iface_init(const void *unused)
840 {
841 
842 	V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
843 }
844 VNET_SYSINIT(vnet_ng_iface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
845     vnet_ng_iface_init, NULL);
846 
847 static void
848 vnet_ng_iface_uninit(const void *unused)
849 {
850 
851 	delete_unrhdr(V_ng_iface_unit);
852 }
853 VNET_SYSUNINIT(vnet_ng_iface_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY,
854     vnet_ng_iface_uninit, NULL);
855