xref: /dragonfly/sys/netgraph/iface/ng_iface.c (revision ef9870ec)
1 
2 /*
3  * ng_iface.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Archie Cobbs <archie@freebsd.org>
38  *
39  * $FreeBSD: src/sys/netgraph/ng_iface.c,v 1.7.2.5 2002/07/02 23:44:02 archie Exp $
40  * $Whistle: ng_iface.c,v 1.33 1999/11/01 09:24:51 julian Exp $
41  */
42 
43 /*
44  * This node is also a system networking interface. It has
45  * a hook for each protocol (IP, AppleTalk, IPX, etc). Packets
46  * are simply relayed between the interface and the hooks.
47  *
48  * Interfaces are named ng0, ng1, etc.  New nodes take the
49  * first available interface name.
50  *
51  * This node also includes Berkeley packet filter support.
52  */
53 
54 #include "opt_inet.h"
55 #include "opt_inet6.h"
56 #include "opt_ipx.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/sockio.h>
66 #include <sys/socket.h>
67 #include <sys/syslog.h>
68 #include <sys/libkern.h>
69 #include <sys/thread2.h>
70 
71 #include <net/if.h>
72 #include <net/if_types.h>
73 #include <net/ifq_var.h>
74 #include <net/netisr.h>
75 #include <net/bpf.h>
76 
77 #include <netinet/in.h>
78 
79 #include <netgraph/ng_message.h>
80 #include <netgraph/netgraph.h>
81 #include <netgraph/ng_parse.h>
82 #include "ng_iface.h"
83 #include <netgraph/cisco/ng_cisco.h>
84 
85 /* This struct describes one address family */
86 struct iffam {
87 	sa_family_t	family;		/* Address family */
88 	const char	*hookname;	/* Name for hook */
89 };
90 typedef const struct iffam *iffam_p;
91 
92 /* List of address families supported by our interface */
93 static const struct iffam gFamilies[] = {
94 	{ AF_INET,	NG_IFACE_HOOK_INET	},
95 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
96 	{ AF_IPX,	NG_IFACE_HOOK_IPX	},
97 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
98 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
99 	{ AF_NS,	NG_IFACE_HOOK_NS	},
100 };
101 #define NUM_FAMILIES		NELEM(gFamilies)
102 
103 /* Node private data */
104 struct ng_iface_private {
105 	struct	ifnet *ifp;		/* Our interface */
106 	int	unit;			/* Interface unit number */
107 	node_p	node;			/* Our netgraph node */
108 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
109 };
110 typedef struct ng_iface_private *priv_p;
111 
112 /* Interface methods */
113 static void	ng_iface_start(struct ifnet *ifp);
114 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data,
115 			struct ucred *cr);
116 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
117 			struct sockaddr *dst, struct rtentry *rt0);
118 static void	ng_iface_bpftap(struct ifnet *ifp,
119 			struct mbuf *m, sa_family_t family);
120 #ifdef DEBUG
121 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
122 #endif
123 
124 /* Netgraph methods */
125 static ng_constructor_t	ng_iface_constructor;
126 static ng_rcvmsg_t	ng_iface_rcvmsg;
127 static ng_shutdown_t	ng_iface_rmnode;
128 static ng_newhook_t	ng_iface_newhook;
129 static ng_rcvdata_t	ng_iface_rcvdata;
130 static ng_disconnect_t	ng_iface_disconnect;
131 
132 /* Helper stuff */
133 static iffam_p	get_iffam_from_af(sa_family_t family);
134 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
135 static iffam_p	get_iffam_from_name(const char *name);
136 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
137 
138 /* Parse type for struct ng_iface_ifname */
139 static const struct ng_parse_fixedstring_info ng_iface_ifname_info = {
140 	NG_IFACE_IFACE_NAME_MAX + 1
141 };
142 static const struct ng_parse_type ng_iface_ifname_type = {
143 	&ng_parse_fixedstring_type,
144 	&ng_iface_ifname_info
145 };
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_iface_ifname_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 	{ 0 }
186 };
187 
188 /* Node type descriptor */
189 static struct ng_type typestruct = {
190 	NG_VERSION,
191 	NG_IFACE_NODE_TYPE,
192 	NULL,
193 	ng_iface_constructor,
194 	ng_iface_rcvmsg,
195 	ng_iface_rmnode,
196 	ng_iface_newhook,
197 	NULL,
198 	NULL,
199 	ng_iface_rcvdata,
200 	ng_iface_rcvdata,
201 	ng_iface_disconnect,
202 	ng_iface_cmds
203 };
204 NETGRAPH_INIT(iface, &typestruct);
205 
206 /* We keep a bitmap indicating which unit numbers are free.
207    One means the unit number is free, zero means it's taken. */
208 static int	*ng_iface_units = NULL;
209 static int	ng_iface_units_len = 0;
210 
211 #define UNITS_BITSPERWORD	(sizeof(*ng_iface_units) * NBBY)
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  * Find the first free unit number for a new interface.
277  * Increase the size of the unit bitmap as necessary.
278  */
279 static __inline__ int
280 ng_iface_get_unit(int *unit)
281 {
282 	int index, bit;
283 
284 	for (index = 0; index < ng_iface_units_len
285 	    && ng_iface_units[index] == 0; index++);
286 	if (index == ng_iface_units_len) {		/* extend array */
287 		int i, *newarray, newlen;
288 
289 		newlen = (2 * ng_iface_units_len) + 4;
290 		newarray = kmalloc(newlen * sizeof(*ng_iface_units),
291 				   M_NETGRAPH, M_NOWAIT);
292 		if (newarray == NULL)
293 			return (ENOMEM);
294 		bcopy(ng_iface_units, newarray,
295 		    ng_iface_units_len * sizeof(*ng_iface_units));
296 		for (i = ng_iface_units_len; i < newlen; i++)
297 			newarray[i] = ~0;
298 		if (ng_iface_units != NULL)
299 			kfree(ng_iface_units, M_NETGRAPH);
300 		ng_iface_units = newarray;
301 		ng_iface_units_len = newlen;
302 	}
303 	bit = ffs(ng_iface_units[index]) - 1;
304 	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
305 	    ("%s: word=%d bit=%d", __func__, ng_iface_units[index], bit));
306 	ng_iface_units[index] &= ~(1 << bit);
307 	*unit = (index * UNITS_BITSPERWORD) + bit;
308 	return (0);
309 }
310 
311 /*
312  * Free a no longer needed unit number.
313  */
314 static __inline__ void
315 ng_iface_free_unit(int unit)
316 {
317 	int index, bit;
318 
319 	index = unit / UNITS_BITSPERWORD;
320 	bit = unit % UNITS_BITSPERWORD;
321 	KASSERT(index < ng_iface_units_len,
322 	    ("%s: unit=%d len=%d", __func__, unit, ng_iface_units_len));
323 	KASSERT((ng_iface_units[index] & (1 << bit)) == 0,
324 	    ("%s: unit=%d is free", __func__, unit));
325 	ng_iface_units[index] |= (1 << bit);
326 	/*
327 	 * XXX We could think about reducing the size of ng_iface_units[]
328 	 * XXX here if the last portion is all ones
329 	 */
330 }
331 
332 /************************************************************************
333 			INTERFACE STUFF
334  ************************************************************************/
335 
336 /*
337  * Process an ioctl for the virtual interface
338  */
339 static int
340 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data,
341     struct ucred *cr)
342 {
343 	struct ifreq *const ifr = (struct ifreq *) data;
344 	int error = 0;
345 
346 #ifdef DEBUG
347 	ng_iface_print_ioctl(ifp, command, data);
348 #endif
349 	crit_enter();
350 	switch (command) {
351 
352 	/* These two are mostly handled at a higher layer */
353 	case SIOCSIFADDR:
354 		ifp->if_flags |= (IFF_UP | IFF_RUNNING);
355 		ifp->if_flags &= ~(IFF_OACTIVE);
356 		break;
357 	case SIOCGIFADDR:
358 		break;
359 
360 	/* Set flags */
361 	case SIOCSIFFLAGS:
362 		/*
363 		 * If the interface is marked up and stopped, then start it.
364 		 * If it is marked down and running, then stop it.
365 		 */
366 		if (ifr->ifr_flags & IFF_UP) {
367 			if (!(ifp->if_flags & IFF_RUNNING)) {
368 				ifp->if_flags &= ~(IFF_OACTIVE);
369 				ifp->if_flags |= IFF_RUNNING;
370 			}
371 		} else {
372 			if (ifp->if_flags & IFF_RUNNING)
373 				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
374 		}
375 		break;
376 
377 	/* Set the interface MTU */
378 	case SIOCSIFMTU:
379 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
380 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
381 			error = EINVAL;
382 		else
383 			ifp->if_mtu = ifr->ifr_mtu;
384 		break;
385 
386 	/* Stuff that's not supported */
387 	case SIOCADDMULTI:
388 	case SIOCDELMULTI:
389 		error = 0;
390 		break;
391 	case SIOCSIFPHYS:
392 		error = EOPNOTSUPP;
393 		break;
394 
395 	default:
396 		error = EINVAL;
397 		break;
398 	}
399 	crit_exit();
400 	return (error);
401 }
402 
403 /*
404  * This routine is called to deliver a packet out the interface.
405  * We simply look at the address family and relay the packet to
406  * the corresponding hook, if it exists and is connected.
407  */
408 
409 static int
410 ng_iface_output_serialized(struct ifnet *ifp, struct mbuf *m,
411 			   struct sockaddr *dst, struct rtentry *rt0)
412 {
413 	const priv_p priv = (priv_p) ifp->if_softc;
414 	const iffam_p iffam = get_iffam_from_af(dst->sa_family);
415 	meta_p meta = NULL;
416 	int len, error = 0;
417 
418 	/* Check interface flags */
419 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
420 		m_freem(m);
421 		return (ENETDOWN);
422 	}
423 
424 	/* BPF writes need to be handled specially */
425 	if (dst->sa_family == AF_UNSPEC) {
426 		if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
427 			return (ENOBUFS);
428 		dst->sa_family = (sa_family_t)*mtod(m, int32_t *);
429 		m->m_data += 4;
430 		m->m_len -= 4;
431 		m->m_pkthdr.len -= 4;
432 	}
433 
434 	/* Berkeley packet filter */
435 	ng_iface_bpftap(ifp, m, dst->sa_family);
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",
441 		       ifp->if_xname, (int)dst->sa_family);
442 		return (EAFNOSUPPORT);
443 	}
444 
445 	/* Copy length before the mbuf gets invalidated */
446 	len = m->m_pkthdr.len;
447 
448 	/* Send packet; if hook is not connected, mbuf will get freed. */
449 	NG_SEND_DATA(error, *get_hook_from_iffam(priv, iffam), m, meta);
450 
451 	/* Update stats */
452 	if (error == 0) {
453 		ifp->if_obytes += len;
454 		ifp->if_opackets++;
455 	}
456 	return (error);
457 }
458 
459 static int
460 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
461 		struct sockaddr *dst, struct rtentry *rt0)
462 {
463 	int error;
464 
465 	ifnet_serialize_tx(ifp);
466 	error = ng_iface_output_serialized(ifp, m, dst, rt0);
467 	ifnet_deserialize_tx(ifp);
468 
469 	return error;
470 }
471 
472 /*
473  * This routine should never be called
474  */
475 
476 static void
477 ng_iface_start(struct ifnet *ifp)
478 {
479 	kprintf("%s: %s called?", ifp->if_xname, __func__);
480 }
481 
482 /*
483  * Flash a packet by the BPF (requires prepending 4 byte AF header)
484  */
485 static void
486 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
487 {
488 	int32_t family4 = (int32_t)family;
489 
490 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
491 
492 	if (ifp->if_bpf) {
493 		bpf_gettoken();
494 		if (ifp->if_bpf)
495 			bpf_ptap(ifp->if_bpf, m, &family, sizeof(family4));
496 		bpf_reltoken();
497 	}
498 }
499 
500 #ifdef DEBUG
501 /*
502  * Display an ioctl to the virtual interface
503  */
504 
505 static void
506 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
507 {
508 	char   *str;
509 
510 	switch (command & IOC_DIRMASK) {
511 	case IOC_VOID:
512 		str = "IO";
513 		break;
514 	case IOC_OUT:
515 		str = "IOR";
516 		break;
517 	case IOC_IN:
518 		str = "IOW";
519 		break;
520 	case IOC_INOUT:
521 		str = "IORW";
522 		break;
523 	default:
524 		str = "IO??";
525 	}
526 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
527 	       ifp->if_xname,
528 	       str,
529 	       IOCGROUP(command),
530 	       command & 0xff,
531 	       IOCPARM_LEN(command));
532 }
533 #endif /* DEBUG */
534 
535 /************************************************************************
536 			NETGRAPH NODE STUFF
537  ************************************************************************/
538 
539 /*
540  * Constructor for a node
541  */
542 static int
543 ng_iface_constructor(node_p *nodep)
544 {
545 	char ifname[NG_IFACE_IFACE_NAME_MAX + 1];
546 	struct ifnet *ifp;
547 	node_p node;
548 	priv_p priv;
549 	int error = 0;
550 
551 	/* Allocate node and interface private structures */
552 	priv = kmalloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
553 	if (priv == NULL)
554 		return (ENOMEM);
555 	ifp = kmalloc(sizeof(*ifp), M_NETGRAPH, M_NOWAIT | M_ZERO);
556 	if (ifp == NULL) {
557 		kfree(priv, M_NETGRAPH);
558 		return (ENOMEM);
559 	}
560 
561 	/* Link them together */
562 	ifp->if_softc = priv;
563 	priv->ifp = ifp;
564 
565 	/* Get an interface unit number */
566 	if ((error = ng_iface_get_unit(&priv->unit)) != 0) {
567 		kfree(ifp, M_NETGRAPH);
568 		kfree(priv, M_NETGRAPH);
569 		return (error);
570 	}
571 
572 	/* Call generic node constructor */
573 	if ((error = ng_make_node_common(&typestruct, nodep)) != 0) {
574 		ng_iface_free_unit(priv->unit);
575 		kfree(ifp, M_NETGRAPH);
576 		kfree(priv, M_NETGRAPH);
577 		return (error);
578 	}
579 	node = *nodep;
580 
581 	/* Link together node and private info */
582 	node->private = priv;
583 	priv->node = node;
584 
585 	/* Initialize interface structure */
586 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
587 	ifp->if_output = ng_iface_output;
588 	ifp->if_start = ng_iface_start;
589 	ifp->if_ioctl = ng_iface_ioctl;
590 	ifp->if_watchdog = NULL;
591 	ifq_set_maxlen(&ifp->if_snd, IFQ_MAXLEN);
592 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
593 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
594 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
595 	ifp->if_addrlen = 0;			/* XXX */
596 	ifp->if_hdrlen = 0;			/* XXX */
597 	ifp->if_baudrate = 64000;		/* XXX */
598 
599 	/* Give this node the same name as the interface (if possible) */
600 	bzero(ifname, sizeof(ifname));
601 	strlcpy(ifname, ifp->if_xname, sizeof(ifname));
602 	if (ng_name_node(node, ifname) != 0)
603 		log(LOG_WARNING, "%s: can't acquire netgraph name\n", ifname);
604 
605 	/* Attach the interface */
606 	if_attach(ifp, NULL);
607 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
608 
609 	/* Done */
610 	return (0);
611 }
612 
613 /*
614  * Give our ok for a hook to be added
615  */
616 static int
617 ng_iface_newhook(node_p node, hook_p hook, const char *name)
618 {
619 	const iffam_p iffam = get_iffam_from_name(name);
620 	hook_p *hookptr;
621 
622 	if (iffam == NULL)
623 		return (EPFNOSUPPORT);
624 	hookptr = get_hook_from_iffam((priv_p) node->private, iffam);
625 	if (*hookptr != NULL)
626 		return (EISCONN);
627 	*hookptr = hook;
628 	return (0);
629 }
630 
631 /*
632  * Receive a control message
633  */
634 static int
635 ng_iface_rcvmsg(node_p node, struct ng_mesg *msg,
636 		const char *retaddr, struct ng_mesg **rptr)
637 {
638 	const priv_p priv = node->private;
639 	struct ifnet *const ifp = priv->ifp;
640 	struct ng_mesg *resp = NULL;
641 	int error = 0;
642 
643 	switch (msg->header.typecookie) {
644 	case NGM_IFACE_COOKIE:
645 		switch (msg->header.cmd) {
646 		case NGM_IFACE_GET_IFNAME:
647 		    {
648 			struct ng_iface_ifname *arg;
649 
650 			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
651 			if (resp == NULL) {
652 				error = ENOMEM;
653 				break;
654 			}
655 			arg = (struct ng_iface_ifname *)resp->data;
656 			strlcpy(arg->ngif_name, ifp->if_xname,
657 			    sizeof(arg->ngif_name));
658 			break;
659 		    }
660 
661 		case NGM_IFACE_POINT2POINT:
662 		case NGM_IFACE_BROADCAST:
663 		    {
664 
665 			/* Deny request if interface is UP */
666 			if ((ifp->if_flags & IFF_UP) != 0)
667 				return (EBUSY);
668 
669 			/* Change flags */
670 			switch (msg->header.cmd) {
671 			case NGM_IFACE_POINT2POINT:
672 				ifp->if_flags |= IFF_POINTOPOINT;
673 				ifp->if_flags &= ~IFF_BROADCAST;
674 				break;
675 			case NGM_IFACE_BROADCAST:
676 				ifp->if_flags &= ~IFF_POINTOPOINT;
677 				ifp->if_flags |= IFF_BROADCAST;
678 				break;
679 			}
680 			break;
681 		    }
682 
683 		default:
684 			error = EINVAL;
685 			break;
686 		}
687 		break;
688 	case NGM_CISCO_COOKIE:
689 		switch (msg->header.cmd) {
690 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
691 		    {
692 			struct ifaddr_container *ifac;
693 
694 			/* Return the first configured IP address */
695 			TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid],
696 				      ifa_link) {
697 				struct ifaddr *ifa = ifac->ifa;
698 				struct ng_cisco_ipaddr *ips;
699 
700 				if (ifa->ifa_addr->sa_family != AF_INET)
701 					continue;
702 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
703 				if (resp == NULL) {
704 					error = ENOMEM;
705 					break;
706 				}
707 				ips = (struct ng_cisco_ipaddr *)resp->data;
708 				ips->ipaddr = ((struct sockaddr_in *)
709 						ifa->ifa_addr)->sin_addr;
710 				ips->netmask = ((struct sockaddr_in *)
711 						ifa->ifa_netmask)->sin_addr;
712 				break;
713 			}
714 
715 			/* No IP addresses on this interface? */
716 			if (ifac == NULL)
717 				error = EADDRNOTAVAIL;
718 			break;
719 		    }
720 		default:
721 			error = EINVAL;
722 			break;
723 		}
724 		break;
725 	default:
726 		error = EINVAL;
727 		break;
728 	}
729 	if (rptr)
730 		*rptr = resp;
731 	else if (resp)
732 		kfree(resp, M_NETGRAPH);
733 	kfree(msg, M_NETGRAPH);
734 	return (error);
735 }
736 
737 /*
738  * Recive data from a hook. Pass the packet to the correct input routine.
739  */
740 static int
741 ng_iface_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
742 {
743 	const priv_p priv = hook->node->private;
744 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
745 	struct ifnet *const ifp = priv->ifp;
746 	int isr;
747 
748 	/* Sanity checks */
749 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
750 	KASSERT(m->m_flags & M_PKTHDR, ("%s: not pkthdr", __func__));
751 	if (m == NULL)
752 		return (EINVAL);
753 	if ((ifp->if_flags & IFF_UP) == 0) {
754 		NG_FREE_DATA(m, meta);
755 		return (ENETDOWN);
756 	}
757 
758 	/* Update interface stats */
759 	ifp->if_ipackets++;
760 	ifp->if_ibytes += m->m_pkthdr.len;
761 
762 	/* Note receiving interface */
763 	m->m_pkthdr.rcvif = ifp;
764 
765 	/* Berkeley packet filter */
766 	ng_iface_bpftap(ifp, m, iffam->family);
767 
768 	/* Ignore any meta-data */
769 	NG_FREE_META(meta);
770 
771 	/* Send packet */
772 	switch (iffam->family) {
773 #ifdef INET
774 	case AF_INET:
775 		isr = NETISR_IP;
776 		break;
777 #endif
778 #ifdef INET6
779 	case AF_INET6:
780 		isr = NETISR_IPV6;
781 		break;
782 #endif
783 #ifdef IPX
784 	case AF_IPX:
785 		isr = NETISR_IPX;
786 		break;
787 #endif
788 	default:
789 		m_freem(m);
790 		return (EAFNOSUPPORT);
791 	}
792 	netisr_queue(isr, m);
793 	return (0);
794 }
795 
796 /*
797  * Shutdown and remove the node and its associated interface.
798  */
799 static int
800 ng_iface_rmnode(node_p node)
801 {
802 	const priv_p priv = node->private;
803 
804 	ng_cutlinks(node);
805 	ng_unname(node);
806 	bpfdetach(priv->ifp);
807 	if_detach(priv->ifp);
808 	kfree(priv->ifp, M_NETGRAPH);
809 	priv->ifp = NULL;
810 	ng_iface_free_unit(priv->unit);
811 	kfree(priv, M_NETGRAPH);
812 	node->private = NULL;
813 	ng_unref(node);
814 	return (0);
815 }
816 
817 /*
818  * Hook disconnection. Note that we do *not* shutdown when all
819  * hooks have been disconnected.
820  */
821 static int
822 ng_iface_disconnect(hook_p hook)
823 {
824 	const priv_p priv = hook->node->private;
825 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
826 
827 	if (iffam == NULL)
828 		panic(__func__);
829 	*get_hook_from_iffam(priv, iffam) = NULL;
830 	return (0);
831 }
832 
833