xref: /dragonfly/sys/netgraph/iface/ng_iface.c (revision 28c7b939)
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  * $DragonFly: src/sys/netgraph/iface/ng_iface.c,v 1.6 2004/01/06 03:17:27 dillon Exp $
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, IPX, 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 #include "opt_ipx.h"
59 
60 #include <sys/param.h>
61 #include <sys/systm.h>
62 #include <sys/errno.h>
63 #include <sys/kernel.h>
64 #include <sys/malloc.h>
65 #include <sys/mbuf.h>
66 #include <sys/errno.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_types.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 const static struct iffam gFamilies[] = {
94 	{ AF_INET,	NG_IFACE_HOOK_INET	},
95 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
96 	{ AF_APPLETALK,	NG_IFACE_HOOK_ATALK	},
97 	{ AF_IPX,	NG_IFACE_HOOK_IPX	},
98 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
99 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
100 	{ AF_NS,	NG_IFACE_HOOK_NS	},
101 };
102 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
103 
104 /* Node private data */
105 struct ng_iface_private {
106 	struct	ifnet *ifp;		/* Our interface */
107 	int	unit;			/* Interface unit number */
108 	node_p	node;			/* Our netgraph node */
109 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
110 };
111 typedef struct ng_iface_private *priv_p;
112 
113 /* Interface methods */
114 static void	ng_iface_start(struct ifnet *ifp);
115 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
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 		MALLOC(newarray, int *, 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 			FREE(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", __FUNCTION__, 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", __FUNCTION__, unit, ng_iface_units_len));
323 	KASSERT((ng_iface_units[index] & (1 << bit)) == 0,
324 	    ("%s: unit=%d is free", __FUNCTION__, 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 {
342 	struct ifreq *const ifr = (struct ifreq *) data;
343 	int s, error = 0;
344 
345 #ifdef DEBUG
346 	ng_iface_print_ioctl(ifp, command, data);
347 #endif
348 	s = splimp();
349 	switch (command) {
350 
351 	/* These two are mostly handled at a higher layer */
352 	case SIOCSIFADDR:
353 		ifp->if_flags |= (IFF_UP | IFF_RUNNING);
354 		ifp->if_flags &= ~(IFF_OACTIVE);
355 		break;
356 	case SIOCGIFADDR:
357 		break;
358 
359 	/* Set flags */
360 	case SIOCSIFFLAGS:
361 		/*
362 		 * If the interface is marked up and stopped, then start it.
363 		 * If it is marked down and running, then stop it.
364 		 */
365 		if (ifr->ifr_flags & IFF_UP) {
366 			if (!(ifp->if_flags & IFF_RUNNING)) {
367 				ifp->if_flags &= ~(IFF_OACTIVE);
368 				ifp->if_flags |= IFF_RUNNING;
369 			}
370 		} else {
371 			if (ifp->if_flags & IFF_RUNNING)
372 				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
373 		}
374 		break;
375 
376 	/* Set the interface MTU */
377 	case SIOCSIFMTU:
378 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
379 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
380 			error = EINVAL;
381 		else
382 			ifp->if_mtu = ifr->ifr_mtu;
383 		break;
384 
385 	/* Stuff that's not supported */
386 	case SIOCADDMULTI:
387 	case SIOCDELMULTI:
388 		error = 0;
389 		break;
390 	case SIOCSIFPHYS:
391 		error = EOPNOTSUPP;
392 		break;
393 
394 	default:
395 		error = EINVAL;
396 		break;
397 	}
398 	(void) splx(s);
399 	return (error);
400 }
401 
402 /*
403  * This routine is called to deliver a packet out the interface.
404  * We simply look at the address family and relay the packet to
405  * the corresponding hook, if it exists and is connected.
406  */
407 
408 static int
409 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
410 		struct sockaddr *dst, struct rtentry *rt0)
411 {
412 	const priv_p priv = (priv_p) ifp->if_softc;
413 	const iffam_p iffam = get_iffam_from_af(dst->sa_family);
414 	meta_p meta = NULL;
415 	int len, error = 0;
416 
417 	/* Check interface flags */
418 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
419 		m_freem(m);
420 		return (ENETDOWN);
421 	}
422 
423 	/* BPF writes need to be handled specially */
424 	if (dst->sa_family == AF_UNSPEC) {
425 		if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
426 			return (ENOBUFS);
427 		dst->sa_family = (sa_family_t)*mtod(m, int32_t *);
428 		m->m_data += 4;
429 		m->m_len -= 4;
430 		m->m_pkthdr.len -= 4;
431 	}
432 
433 	/* Berkeley packet filter */
434 	ng_iface_bpftap(ifp, m, dst->sa_family);
435 
436 	/* Check address family to determine hook (if known) */
437 	if (iffam == NULL) {
438 		m_freem(m);
439 		log(LOG_WARNING, "%s: can't handle af%d\n",
440 		       ifp->if_xname, (int)dst->sa_family);
441 		return (EAFNOSUPPORT);
442 	}
443 
444 	/* Copy length before the mbuf gets invalidated */
445 	len = m->m_pkthdr.len;
446 
447 	/* Send packet; if hook is not connected, mbuf will get freed. */
448 	NG_SEND_DATA(error, *get_hook_from_iffam(priv, iffam), m, meta);
449 
450 	/* Update stats */
451 	if (error == 0) {
452 		ifp->if_obytes += len;
453 		ifp->if_opackets++;
454 	}
455 	return (error);
456 }
457 
458 /*
459  * This routine should never be called
460  */
461 
462 static void
463 ng_iface_start(struct ifnet *ifp)
464 {
465 	printf("%s: %s called?", ifp->if_xname, __FUNCTION__);
466 }
467 
468 /*
469  * Flash a packet by the BPF (requires prepending 4 byte AF header)
470  * Note the phoney mbuf; this is OK because BPF treats it read-only.
471  */
472 static void
473 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
474 {
475 	int32_t family4 = (int32_t)family;
476 	struct mbuf m0;
477 
478 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __FUNCTION__));
479 	if (ifp->if_bpf != NULL) {
480 		bzero(&m0, sizeof(m0));
481 		m0.m_next = m;
482 		m0.m_len = sizeof(family4);
483 		m0.m_data = (char *)&family4;
484 		bpf_mtap(ifp, &m0);
485 	}
486 }
487 
488 #ifdef DEBUG
489 /*
490  * Display an ioctl to the virtual interface
491  */
492 
493 static void
494 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
495 {
496 	char   *str;
497 
498 	switch (command & IOC_DIRMASK) {
499 	case IOC_VOID:
500 		str = "IO";
501 		break;
502 	case IOC_OUT:
503 		str = "IOR";
504 		break;
505 	case IOC_IN:
506 		str = "IOW";
507 		break;
508 	case IOC_INOUT:
509 		str = "IORW";
510 		break;
511 	default:
512 		str = "IO??";
513 	}
514 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
515 	       ifp->if_xname,
516 	       str,
517 	       IOCGROUP(command),
518 	       command & 0xff,
519 	       IOCPARM_LEN(command));
520 }
521 #endif /* DEBUG */
522 
523 /************************************************************************
524 			NETGRAPH NODE STUFF
525  ************************************************************************/
526 
527 /*
528  * Constructor for a node
529  */
530 static int
531 ng_iface_constructor(node_p *nodep)
532 {
533 	char ifname[NG_IFACE_IFACE_NAME_MAX + 1];
534 	struct ifnet *ifp;
535 	node_p node;
536 	priv_p priv;
537 	int error = 0;
538 
539 	/* Allocate node and interface private structures */
540 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT);
541 	if (priv == NULL)
542 		return (ENOMEM);
543 	bzero(priv, sizeof(*priv));
544 	MALLOC(ifp, struct ifnet *, sizeof(*ifp), M_NETGRAPH, M_NOWAIT);
545 	if (ifp == NULL) {
546 		FREE(priv, M_NETGRAPH);
547 		return (ENOMEM);
548 	}
549 	bzero(ifp, sizeof(*ifp));
550 
551 	/* Link them together */
552 	ifp->if_softc = priv;
553 	priv->ifp = ifp;
554 
555 	/* Get an interface unit number */
556 	if ((error = ng_iface_get_unit(&priv->unit)) != 0) {
557 		FREE(ifp, M_NETGRAPH);
558 		FREE(priv, M_NETGRAPH);
559 		return (error);
560 	}
561 
562 	/* Call generic node constructor */
563 	if ((error = ng_make_node_common(&typestruct, nodep)) != 0) {
564 		ng_iface_free_unit(priv->unit);
565 		FREE(ifp, M_NETGRAPH);
566 		FREE(priv, M_NETGRAPH);
567 		return (error);
568 	}
569 	node = *nodep;
570 
571 	/* Link together node and private info */
572 	node->private = priv;
573 	priv->node = node;
574 
575 	/* Initialize interface structure */
576 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
577 	ifp->if_output = ng_iface_output;
578 	ifp->if_start = ng_iface_start;
579 	ifp->if_ioctl = ng_iface_ioctl;
580 	ifp->if_watchdog = NULL;
581 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
582 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
583 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
584 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
585 	ifp->if_addrlen = 0;			/* XXX */
586 	ifp->if_hdrlen = 0;			/* XXX */
587 	ifp->if_baudrate = 64000;		/* XXX */
588 	TAILQ_INIT(&ifp->if_addrhead);
589 
590 	/* Give this node the same name as the interface (if possible) */
591 	bzero(ifname, sizeof(ifname));
592 	strlcpy(ifname, ifp->if_xname, sizeof(ifname));
593 	if (ng_name_node(node, ifname) != 0)
594 		log(LOG_WARNING, "%s: can't acquire netgraph name\n", ifname);
595 
596 	/* Attach the interface */
597 	if_attach(ifp);
598 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
599 
600 	/* Done */
601 	return (0);
602 }
603 
604 /*
605  * Give our ok for a hook to be added
606  */
607 static int
608 ng_iface_newhook(node_p node, hook_p hook, const char *name)
609 {
610 	const iffam_p iffam = get_iffam_from_name(name);
611 	hook_p *hookptr;
612 
613 	if (iffam == NULL)
614 		return (EPFNOSUPPORT);
615 	hookptr = get_hook_from_iffam((priv_p) node->private, iffam);
616 	if (*hookptr != NULL)
617 		return (EISCONN);
618 	*hookptr = hook;
619 	return (0);
620 }
621 
622 /*
623  * Receive a control message
624  */
625 static int
626 ng_iface_rcvmsg(node_p node, struct ng_mesg *msg,
627 		const char *retaddr, struct ng_mesg **rptr)
628 {
629 	const priv_p priv = node->private;
630 	struct ifnet *const ifp = priv->ifp;
631 	struct ng_mesg *resp = NULL;
632 	int error = 0;
633 
634 	switch (msg->header.typecookie) {
635 	case NGM_IFACE_COOKIE:
636 		switch (msg->header.cmd) {
637 		case NGM_IFACE_GET_IFNAME:
638 		    {
639 			struct ng_iface_ifname *arg;
640 
641 			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
642 			if (resp == NULL) {
643 				error = ENOMEM;
644 				break;
645 			}
646 			arg = (struct ng_iface_ifname *)resp->data;
647 			strlcpy(arg->ngif_name, ifp->if_xname,
648 			    sizeof(arg->ngif_name));
649 			break;
650 		    }
651 
652 		case NGM_IFACE_POINT2POINT:
653 		case NGM_IFACE_BROADCAST:
654 		    {
655 
656 			/* Deny request if interface is UP */
657 			if ((ifp->if_flags & IFF_UP) != 0)
658 				return (EBUSY);
659 
660 			/* Change flags */
661 			switch (msg->header.cmd) {
662 			case NGM_IFACE_POINT2POINT:
663 				ifp->if_flags |= IFF_POINTOPOINT;
664 				ifp->if_flags &= ~IFF_BROADCAST;
665 				break;
666 			case NGM_IFACE_BROADCAST:
667 				ifp->if_flags &= ~IFF_POINTOPOINT;
668 				ifp->if_flags |= IFF_BROADCAST;
669 				break;
670 			}
671 			break;
672 		    }
673 
674 		default:
675 			error = EINVAL;
676 			break;
677 		}
678 		break;
679 	case NGM_CISCO_COOKIE:
680 		switch (msg->header.cmd) {
681 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
682 		    {
683 			struct ifaddr *ifa;
684 
685 			/* Return the first configured IP address */
686 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
687 				struct ng_cisco_ipaddr *ips;
688 
689 				if (ifa->ifa_addr->sa_family != AF_INET)
690 					continue;
691 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
692 				if (resp == NULL) {
693 					error = ENOMEM;
694 					break;
695 				}
696 				ips = (struct ng_cisco_ipaddr *)resp->data;
697 				ips->ipaddr = ((struct sockaddr_in *)
698 						ifa->ifa_addr)->sin_addr;
699 				ips->netmask = ((struct sockaddr_in *)
700 						ifa->ifa_netmask)->sin_addr;
701 				break;
702 			}
703 
704 			/* No IP addresses on this interface? */
705 			if (ifa == NULL)
706 				error = EADDRNOTAVAIL;
707 			break;
708 		    }
709 		default:
710 			error = EINVAL;
711 			break;
712 		}
713 		break;
714 	default:
715 		error = EINVAL;
716 		break;
717 	}
718 	if (rptr)
719 		*rptr = resp;
720 	else if (resp)
721 		FREE(resp, M_NETGRAPH);
722 	FREE(msg, M_NETGRAPH);
723 	return (error);
724 }
725 
726 /*
727  * Recive data from a hook. Pass the packet to the correct input routine.
728  */
729 static int
730 ng_iface_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
731 {
732 	const priv_p priv = hook->node->private;
733 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
734 	struct ifnet *const ifp = priv->ifp;
735 	int isr;
736 
737 	/* Sanity checks */
738 	KASSERT(iffam != NULL, ("%s: iffam", __FUNCTION__));
739 	KASSERT(m->m_flags & M_PKTHDR, ("%s: not pkthdr", __FUNCTION__));
740 	if (m == NULL)
741 		return (EINVAL);
742 	if ((ifp->if_flags & IFF_UP) == 0) {
743 		NG_FREE_DATA(m, meta);
744 		return (ENETDOWN);
745 	}
746 
747 	/* Update interface stats */
748 	ifp->if_ipackets++;
749 	ifp->if_ibytes += m->m_pkthdr.len;
750 
751 	/* Note receiving interface */
752 	m->m_pkthdr.rcvif = ifp;
753 
754 	/* Berkeley packet filter */
755 	ng_iface_bpftap(ifp, m, iffam->family);
756 
757 	/* Ignore any meta-data */
758 	NG_FREE_META(meta);
759 
760 	/* Send packet */
761 	switch (iffam->family) {
762 #ifdef INET
763 	case AF_INET:
764 		isr = NETISR_IP;
765 		break;
766 #endif
767 #ifdef INET6
768 	case AF_INET6:
769 		isr = NETISR_IPV6;
770 		break;
771 #endif
772 #ifdef IPX
773 	case AF_IPX:
774 		isr = NETISR_IPX;
775 		break;
776 #endif
777 #ifdef NETATALK
778 	case AF_APPLETALK:
779 		isr = NETISR_ATALK2;
780 		break;
781 #endif
782 	default:
783 		m_freem(m);
784 		return (EAFNOSUPPORT);
785 	}
786 	netisr_dispatch(isr, m);
787 	return (0);
788 }
789 
790 /*
791  * Shutdown and remove the node and its associated interface.
792  */
793 static int
794 ng_iface_rmnode(node_p node)
795 {
796 	const priv_p priv = node->private;
797 
798 	ng_cutlinks(node);
799 	ng_unname(node);
800 	bpfdetach(priv->ifp);
801 	if_detach(priv->ifp);
802 	FREE(priv->ifp, M_NETGRAPH);
803 	priv->ifp = NULL;
804 	ng_iface_free_unit(priv->unit);
805 	FREE(priv, M_NETGRAPH);
806 	node->private = NULL;
807 	ng_unref(node);
808 	return (0);
809 }
810 
811 /*
812  * Hook disconnection. Note that we do *not* shutdown when all
813  * hooks have been disconnected.
814  */
815 static int
816 ng_iface_disconnect(hook_p hook)
817 {
818 	const priv_p priv = hook->node->private;
819 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
820 
821 	if (iffam == NULL)
822 		panic(__FUNCTION__);
823 	*get_hook_from_iffam(priv, iffam) = NULL;
824 	return (0);
825 }
826 
827