xref: /freebsd/sys/netgraph/ng_iface.c (revision 817420dc8eac7df799c78f5309b75092b7f7cd40)
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  * $FreeBSD$
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 <sys/param.h>
55 #include <sys/systm.h>
56 #include <sys/errno.h>
57 #include <sys/kernel.h>
58 #include <sys/malloc.h>
59 #include <sys/mbuf.h>
60 #include <sys/errno.h>
61 #include <sys/sockio.h>
62 #include <sys/socket.h>
63 #include <sys/syslog.h>
64 #include <sys/libkern.h>
65 
66 #include <net/if.h>
67 #include <net/if_types.h>
68 #include <net/intrq.h>
69 #include <net/bpf.h>
70 
71 #include <netinet/in.h>
72 
73 #include <netgraph/ng_message.h>
74 #include <netgraph/netgraph.h>
75 #include <netgraph/ng_parse.h>
76 #include <netgraph/ng_iface.h>
77 #include <netgraph/ng_cisco.h>
78 
79 /* This struct describes one address family */
80 struct iffam {
81 	sa_family_t	family;		/* Address family */
82 	const char	*hookname;	/* Name for hook */
83 };
84 typedef const struct iffam *iffam_p;
85 
86 /* List of address families supported by our interface */
87 const static struct iffam gFamilies[] = {
88 	{ AF_INET,	NG_IFACE_HOOK_INET	},
89 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
90 	{ AF_APPLETALK,	NG_IFACE_HOOK_ATALK	},
91 	{ AF_IPX,	NG_IFACE_HOOK_IPX	},
92 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
93 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
94 	{ AF_NS,	NG_IFACE_HOOK_NS	},
95 };
96 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
97 
98 /* Node private data */
99 struct ng_iface_private {
100 	struct	ifnet *ifp;		/* Our interface */
101 	int	unit;			/* Interface unit number */
102 	node_p	node;			/* Our netgraph node */
103 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
104 };
105 typedef struct ng_iface_private *priv_p;
106 
107 /* Interface methods */
108 static void	ng_iface_start(struct ifnet *ifp);
109 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
110 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
111 			struct sockaddr *dst, struct rtentry *rt0);
112 static void	ng_iface_bpftap(struct ifnet *ifp,
113 			struct mbuf *m, sa_family_t family);
114 #ifdef DEBUG
115 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
116 #endif
117 
118 /* Netgraph methods */
119 static ng_constructor_t	ng_iface_constructor;
120 static ng_rcvmsg_t	ng_iface_rcvmsg;
121 static ng_shutdown_t	ng_iface_rmnode;
122 static ng_newhook_t	ng_iface_newhook;
123 static ng_rcvdata_t	ng_iface_rcvdata;
124 static ng_disconnect_t	ng_iface_disconnect;
125 
126 /* Helper stuff */
127 static iffam_p	get_iffam_from_af(sa_family_t family);
128 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
129 static iffam_p	get_iffam_from_name(const char *name);
130 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
131 
132 /* Parse type for struct ng_iface_ifname */
133 static const struct ng_parse_fixedstring_info ng_iface_ifname_info = {
134 	NG_IFACE_IFACE_NAME_MAX + 1
135 };
136 static const struct ng_parse_type ng_iface_ifname_type = {
137 	&ng_parse_fixedstring_type,
138 	&ng_iface_ifname_info
139 };
140 
141 /* Parse type for struct ng_cisco_ipaddr */
142 static const struct ng_parse_struct_info
143 	ng_cisco_ipaddr_type_info = NG_CISCO_IPADDR_TYPE_INFO;
144 static const struct ng_parse_type ng_cisco_ipaddr_type = {
145 	&ng_parse_struct_type,
146 	&ng_cisco_ipaddr_type_info
147 };
148 
149 /* List of commands and how to convert arguments to/from ASCII */
150 static const struct ng_cmdlist ng_iface_cmds[] = {
151 	{
152 	  NGM_IFACE_COOKIE,
153 	  NGM_IFACE_GET_IFNAME,
154 	  "getifname",
155 	  NULL,
156 	  &ng_iface_ifname_type
157 	},
158 	{
159 	  NGM_IFACE_COOKIE,
160 	  NGM_IFACE_POINT2POINT,
161 	  "point2point",
162 	  NULL,
163 	  NULL
164 	},
165 	{
166 	  NGM_IFACE_COOKIE,
167 	  NGM_IFACE_BROADCAST,
168 	  "broadcast",
169 	  NULL,
170 	  NULL
171 	},
172 	{
173 	  NGM_CISCO_COOKIE,
174 	  NGM_CISCO_GET_IPADDR,
175 	  "getipaddr",
176 	  NULL,
177 	  &ng_cisco_ipaddr_type
178 	},
179 	{ 0 }
180 };
181 
182 /* Node type descriptor */
183 static struct ng_type typestruct = {
184 	NG_VERSION,
185 	NG_IFACE_NODE_TYPE,
186 	NULL,
187 	ng_iface_constructor,
188 	ng_iface_rcvmsg,
189 	ng_iface_rmnode,
190 	ng_iface_newhook,
191 	NULL,
192 	NULL,
193 	ng_iface_rcvdata,
194 	ng_iface_rcvdata,
195 	ng_iface_disconnect,
196 	ng_iface_cmds
197 };
198 NETGRAPH_INIT(iface, &typestruct);
199 
200 /* We keep a bitmap indicating which unit numbers are free.
201    One means the unit number is free, zero means it's taken. */
202 static int	*ng_iface_units = NULL;
203 static int	ng_iface_units_len = 0;
204 
205 #define UNITS_BITSPERWORD	(sizeof(*ng_iface_units) * NBBY)
206 
207 /************************************************************************
208 			HELPER STUFF
209  ************************************************************************/
210 
211 /*
212  * Get the family descriptor from the family ID
213  */
214 static __inline__ iffam_p
215 get_iffam_from_af(sa_family_t family)
216 {
217 	iffam_p iffam;
218 	int k;
219 
220 	for (k = 0; k < NUM_FAMILIES; k++) {
221 		iffam = &gFamilies[k];
222 		if (iffam->family == family)
223 			return (iffam);
224 	}
225 	return (NULL);
226 }
227 
228 /*
229  * Get the family descriptor from the hook
230  */
231 static __inline__ iffam_p
232 get_iffam_from_hook(priv_p priv, hook_p hook)
233 {
234 	int k;
235 
236 	for (k = 0; k < NUM_FAMILIES; k++)
237 		if (priv->hooks[k] == hook)
238 			return (&gFamilies[k]);
239 	return (NULL);
240 }
241 
242 /*
243  * Get the hook from the iffam descriptor
244  */
245 
246 static __inline__ hook_p *
247 get_hook_from_iffam(priv_p priv, iffam_p iffam)
248 {
249 	return (&priv->hooks[iffam - gFamilies]);
250 }
251 
252 /*
253  * Get the iffam descriptor from the name
254  */
255 static __inline__ iffam_p
256 get_iffam_from_name(const char *name)
257 {
258 	iffam_p iffam;
259 	int k;
260 
261 	for (k = 0; k < NUM_FAMILIES; k++) {
262 		iffam = &gFamilies[k];
263 		if (!strcmp(iffam->hookname, name))
264 			return (iffam);
265 	}
266 	return (NULL);
267 }
268 
269 /*
270  * Find the first free unit number for a new interface.
271  * Increase the size of the unit bitmap as necessary.
272  */
273 static __inline__ int
274 ng_iface_get_unit(int *unit)
275 {
276 	int index, bit;
277 
278 	for (index = 0; index < ng_iface_units_len
279 	    && ng_iface_units[index] == 0; index++);
280 	if (index == ng_iface_units_len) {		/* extend array */
281 		int i, *newarray, newlen;
282 
283 		newlen = (2 * ng_iface_units_len) + 4;
284 		MALLOC(newarray, int *, newlen * sizeof(*ng_iface_units),
285 		    M_NETGRAPH, M_NOWAIT);
286 		if (newarray == NULL)
287 			return (ENOMEM);
288 		bcopy(ng_iface_units, newarray,
289 		    ng_iface_units_len * sizeof(*ng_iface_units));
290 		for (i = ng_iface_units_len; i < newlen; i++)
291 			newarray[i] = ~0;
292 		if (ng_iface_units != NULL)
293 			FREE(ng_iface_units, M_NETGRAPH);
294 		ng_iface_units = newarray;
295 		ng_iface_units_len = newlen;
296 	}
297 	bit = ffs(ng_iface_units[index]) - 1;
298 	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
299 	    ("%s: word=%d bit=%d", __FUNCTION__, ng_iface_units[index], bit));
300 	ng_iface_units[index] &= ~(1 << bit);
301 	*unit = (index * UNITS_BITSPERWORD) + bit;
302 	return (0);
303 }
304 
305 /*
306  * Free a no longer needed unit number.
307  */
308 static __inline__ void
309 ng_iface_free_unit(int unit)
310 {
311 	int index, bit;
312 
313 	index = unit / UNITS_BITSPERWORD;
314 	bit = unit % UNITS_BITSPERWORD;
315 	KASSERT(index < ng_iface_units_len,
316 	    ("%s: unit=%d len=%d", __FUNCTION__, unit, ng_iface_units_len));
317 	KASSERT((ng_iface_units[index] & (1 << bit)) == 0,
318 	    ("%s: unit=%d is free", __FUNCTION__, unit));
319 	ng_iface_units[index] |= (1 << bit);
320 	/*
321 	 * XXX We could think about reducing the size of ng_iface_units[]
322 	 * XXX here if the last portion is all ones
323 	 */
324 }
325 
326 /************************************************************************
327 			INTERFACE STUFF
328  ************************************************************************/
329 
330 /*
331  * Process an ioctl for the virtual interface
332  */
333 static int
334 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
335 {
336 	struct ifreq *const ifr = (struct ifreq *) data;
337 	int s, error = 0;
338 
339 #ifdef DEBUG
340 	ng_iface_print_ioctl(ifp, command, data);
341 #endif
342 	s = splimp();
343 	switch (command) {
344 
345 	/* These two are mostly handled at a higher layer */
346 	case SIOCSIFADDR:
347 		ifp->if_flags |= (IFF_UP | IFF_RUNNING);
348 		ifp->if_flags &= ~(IFF_OACTIVE);
349 		break;
350 	case SIOCGIFADDR:
351 		break;
352 
353 	/* Set flags */
354 	case SIOCSIFFLAGS:
355 		/*
356 		 * If the interface is marked up and stopped, then start it.
357 		 * If it is marked down and running, then stop it.
358 		 */
359 		if (ifr->ifr_flags & IFF_UP) {
360 			if (!(ifp->if_flags & IFF_RUNNING)) {
361 				ifp->if_flags &= ~(IFF_OACTIVE);
362 				ifp->if_flags |= IFF_RUNNING;
363 			}
364 		} else {
365 			if (ifp->if_flags & IFF_RUNNING)
366 				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
367 		}
368 		break;
369 
370 	/* Set the interface MTU */
371 	case SIOCSIFMTU:
372 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
373 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
374 			error = EINVAL;
375 		else
376 			ifp->if_mtu = ifr->ifr_mtu;
377 		break;
378 
379 	/* Stuff that's not supported */
380 	case SIOCADDMULTI:
381 	case SIOCDELMULTI:
382 		error = 0;
383 		break;
384 	case SIOCSIFPHYS:
385 		error = EOPNOTSUPP;
386 		break;
387 
388 	default:
389 		error = EINVAL;
390 		break;
391 	}
392 	(void) splx(s);
393 	return (error);
394 }
395 
396 /*
397  * This routine is called to deliver a packet out the interface.
398  * We simply look at the address family and relay the packet to
399  * the corresponding hook, if it exists and is connected.
400  */
401 
402 static int
403 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
404 		struct sockaddr *dst, struct rtentry *rt0)
405 {
406 	const priv_p priv = (priv_p) ifp->if_softc;
407 	const iffam_p iffam = get_iffam_from_af(dst->sa_family);
408 	meta_p meta = NULL;
409 	int len, error = 0;
410 
411 	/* Check interface flags */
412 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
413 		m_freem(m);
414 		return (ENETDOWN);
415 	}
416 
417 	/* BPF writes need to be handled specially */
418 	if (dst->sa_family == AF_UNSPEC) {
419 		if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
420 			return (ENOBUFS);
421 		dst->sa_family = (sa_family_t)*mtod(m, int32_t *);
422 		m->m_data += 4;
423 		m->m_len -= 4;
424 		m->m_pkthdr.len -= 4;
425 	}
426 
427 	/* Berkeley packet filter */
428 	ng_iface_bpftap(ifp, m, dst->sa_family);
429 
430 	/* Check address family to determine hook (if known) */
431 	if (iffam == NULL) {
432 		m_freem(m);
433 		log(LOG_WARNING, "%s%d: can't handle af%d\n",
434 		       ifp->if_name, ifp->if_unit, (int)dst->sa_family);
435 		return (EAFNOSUPPORT);
436 	}
437 
438 	/* Copy length before the mbuf gets invalidated */
439 	len = m->m_pkthdr.len;
440 
441 	/* Send packet; if hook is not connected, mbuf will get freed. */
442 	NG_SEND_DATA(error, *get_hook_from_iffam(priv, iffam), m, meta);
443 
444 	/* Update stats */
445 	if (error == 0) {
446 		ifp->if_obytes += len;
447 		ifp->if_opackets++;
448 	}
449 	return (error);
450 }
451 
452 /*
453  * This routine should never be called
454  */
455 
456 static void
457 ng_iface_start(struct ifnet *ifp)
458 {
459 	printf("%s%d: %s called?", ifp->if_name, ifp->if_unit, __FUNCTION__);
460 }
461 
462 /*
463  * Flash a packet by the BPF (requires prepending 4 byte AF header)
464  * Note the phoney mbuf; this is OK because BPF treats it read-only.
465  */
466 static void
467 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
468 {
469 	int32_t family4 = (int32_t)family;
470 	struct mbuf m0;
471 
472 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __FUNCTION__));
473 	if (ifp->if_bpf != NULL) {
474 		bzero(&m0, sizeof(m0));
475 		m0.m_next = m;
476 		m0.m_len = sizeof(family4);
477 		m0.m_data = (char *)&family4;
478 		bpf_mtap(ifp, &m0);
479 	}
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%d: %s('%c', %d, char[%d])\n",
509 	       ifp->if_name, ifp->if_unit,
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 *nodep)
526 {
527 	char ifname[NG_IFACE_IFACE_NAME_MAX + 1];
528 	struct ifnet *ifp;
529 	node_p node;
530 	priv_p priv;
531 	int error = 0;
532 
533 	/* Allocate node and interface private structures */
534 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT|M_ZERO);
535 	if (priv == NULL)
536 		return (ENOMEM);
537 	MALLOC(ifp, struct ifnet *, sizeof(*ifp), M_NETGRAPH, M_NOWAIT|M_ZERO);
538 	if (ifp == NULL) {
539 		FREE(priv, M_NETGRAPH);
540 		return (ENOMEM);
541 	}
542 
543 	/* Link them together */
544 	ifp->if_softc = priv;
545 	priv->ifp = ifp;
546 
547 	/* Get an interface unit number */
548 	if ((error = ng_iface_get_unit(&priv->unit)) != 0) {
549 		FREE(ifp, M_NETGRAPH);
550 		FREE(priv, M_NETGRAPH);
551 		return (error);
552 	}
553 
554 	/* Call generic node constructor */
555 	if ((error = ng_make_node_common(&typestruct, nodep)) != 0) {
556 		ng_iface_free_unit(priv->unit);
557 		FREE(ifp, M_NETGRAPH);
558 		FREE(priv, M_NETGRAPH);
559 		return (error);
560 	}
561 	node = *nodep;
562 
563 	/* Link together node and private info */
564 	node->private = priv;
565 	priv->node = node;
566 
567 	/* Initialize interface structure */
568 	ifp->if_name = NG_IFACE_IFACE_NAME;
569 	ifp->if_unit = priv->unit;
570 	ifp->if_output = ng_iface_output;
571 	ifp->if_start = ng_iface_start;
572 	ifp->if_ioctl = ng_iface_ioctl;
573 	ifp->if_watchdog = NULL;
574 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
575 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
576 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
577 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
578 	ifp->if_addrlen = 0;			/* XXX */
579 	ifp->if_hdrlen = 0;			/* XXX */
580 	ifp->if_baudrate = 64000;		/* XXX */
581 	TAILQ_INIT(&ifp->if_addrhead);
582 
583 	/* Give this node the same name as the interface (if possible) */
584 	bzero(ifname, sizeof(ifname));
585 	snprintf(ifname, sizeof(ifname), "%s%d", ifp->if_name, ifp->if_unit);
586 	if (ng_name_node(node, ifname) != 0)
587 		log(LOG_WARNING, "%s: can't acquire netgraph name\n", ifname);
588 
589 	/* Attach the interface */
590 	if_attach(ifp);
591 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
592 
593 	/* Done */
594 	return (0);
595 }
596 
597 /*
598  * Give our ok for a hook to be added
599  */
600 static int
601 ng_iface_newhook(node_p node, hook_p hook, const char *name)
602 {
603 	const iffam_p iffam = get_iffam_from_name(name);
604 	hook_p *hookptr;
605 
606 	if (iffam == NULL)
607 		return (EPFNOSUPPORT);
608 	hookptr = get_hook_from_iffam((priv_p) node->private, iffam);
609 	if (*hookptr != NULL)
610 		return (EISCONN);
611 	*hookptr = hook;
612 	return (0);
613 }
614 
615 /*
616  * Receive a control message
617  */
618 static int
619 ng_iface_rcvmsg(node_p node, struct ng_mesg *msg,
620 		const char *retaddr, struct ng_mesg **rptr, hook_p lasthook)
621 {
622 	const priv_p priv = node->private;
623 	struct ifnet *const ifp = priv->ifp;
624 	struct ng_mesg *resp = NULL;
625 	int error = 0;
626 
627 	switch (msg->header.typecookie) {
628 	case NGM_IFACE_COOKIE:
629 		switch (msg->header.cmd) {
630 		case NGM_IFACE_GET_IFNAME:
631 		    {
632 			struct ng_iface_ifname *arg;
633 
634 			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
635 			if (resp == NULL) {
636 				error = ENOMEM;
637 				break;
638 			}
639 			arg = (struct ng_iface_ifname *)resp->data;
640 			snprintf(arg->ngif_name, sizeof(arg->ngif_name),
641 			    "%s%d", ifp->if_name, ifp->if_unit);
642 			break;
643 		    }
644 
645 		case NGM_IFACE_POINT2POINT:
646 		case NGM_IFACE_BROADCAST:
647 		    {
648 
649 			/* Deny request if interface is UP */
650 			if ((ifp->if_flags & IFF_UP) != 0)
651 				return (EBUSY);
652 
653 			/* Change flags */
654 			switch (msg->header.cmd) {
655 			case NGM_IFACE_POINT2POINT:
656 				ifp->if_flags |= IFF_POINTOPOINT;
657 				ifp->if_flags &= ~IFF_BROADCAST;
658 				break;
659 			case NGM_IFACE_BROADCAST:
660 				ifp->if_flags &= ~IFF_POINTOPOINT;
661 				ifp->if_flags |= IFF_BROADCAST;
662 				break;
663 			}
664 			break;
665 		    }
666 
667 		default:
668 			error = EINVAL;
669 			break;
670 		}
671 		break;
672 	case NGM_CISCO_COOKIE:
673 		switch (msg->header.cmd) {
674 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
675 		    {
676 			struct ifaddr *ifa;
677 
678 			/* Return the first configured IP address */
679 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
680 				struct ng_cisco_ipaddr *ips;
681 
682 				if (ifa->ifa_addr->sa_family != AF_INET)
683 					continue;
684 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
685 				if (resp == NULL) {
686 					error = ENOMEM;
687 					break;
688 				}
689 				ips = (struct ng_cisco_ipaddr *)resp->data;
690 				ips->ipaddr = ((struct sockaddr_in *)
691 						ifa->ifa_addr)->sin_addr;
692 				ips->netmask = ((struct sockaddr_in *)
693 						ifa->ifa_netmask)->sin_addr;
694 				break;
695 			}
696 
697 			/* No IP addresses on this interface? */
698 			if (ifa == NULL)
699 				error = EADDRNOTAVAIL;
700 			break;
701 		    }
702 		default:
703 			error = EINVAL;
704 			break;
705 		}
706 		break;
707 	default:
708 		error = EINVAL;
709 		break;
710 	}
711 	if (rptr)
712 		*rptr = resp;
713 	else if (resp)
714 		FREE(resp, M_NETGRAPH);
715 	FREE(msg, M_NETGRAPH);
716 	return (error);
717 }
718 
719 /*
720  * Recive data from a hook. Pass the packet to the correct input routine.
721  */
722 static int
723 ng_iface_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
724 		struct mbuf **ret_m, meta_p *ret_meta)
725 {
726 	const priv_p priv = hook->node->private;
727 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
728 	struct ifnet *const ifp = priv->ifp;
729 
730 	/* Sanity checks */
731 	KASSERT(iffam != NULL, ("%s: iffam", __FUNCTION__));
732 	KASSERT(m->m_flags & M_PKTHDR, ("%s: not pkthdr", __FUNCTION__));
733 	if (m == NULL)
734 		return (EINVAL);
735 	if ((ifp->if_flags & IFF_UP) == 0) {
736 		NG_FREE_DATA(m, meta);
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 	/* Ignore any meta-data */
751 	NG_FREE_META(meta);
752 
753 	/* Send packet */
754 	return family_enqueue(iffam->family, m);
755 }
756 
757 /*
758  * Shutdown and remove the node and its associated interface.
759  */
760 static int
761 ng_iface_rmnode(node_p node)
762 {
763 	const priv_p priv = node->private;
764 
765 	ng_cutlinks(node);
766 	ng_unname(node);
767 	bpfdetach(priv->ifp);
768 	if_detach(priv->ifp);
769 	priv->ifp = NULL;
770 	ng_iface_free_unit(priv->unit);
771 	FREE(priv, M_NETGRAPH);
772 	node->private = NULL;
773 	ng_unref(node);
774 	return (0);
775 }
776 
777 /*
778  * Hook disconnection. Note that we do *not* shutdown when all
779  * hooks have been disconnected.
780  */
781 static int
782 ng_iface_disconnect(hook_p hook)
783 {
784 	const priv_p priv = hook->node->private;
785 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
786 
787 	if (iffam == NULL)
788 		panic(__FUNCTION__);
789 	*get_hook_from_iffam(priv, iffam) = NULL;
790 	return (0);
791 }
792 
793