xref: /freebsd/sys/netgraph/ng_iface.c (revision c68159a6d8eede11766cf13896d0f7670dbd51aa)
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_shutdown;
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_ABI_VERSION,
185 	NG_IFACE_NODE_TYPE,
186 	NULL,
187 	ng_iface_constructor,
188 	ng_iface_rcvmsg,
189 	ng_iface_shutdown,
190 	ng_iface_newhook,
191 	NULL,
192 	NULL,
193 	ng_iface_rcvdata,
194 	ng_iface_disconnect,
195 	ng_iface_cmds
196 };
197 NETGRAPH_INIT(iface, &typestruct);
198 
199 /* We keep a bitmap indicating which unit numbers are free.
200    One means the unit number is free, zero means it's taken. */
201 static int	*ng_iface_units = NULL;
202 static int	ng_iface_units_len = 0;
203 
204 #define UNITS_BITSPERWORD	(sizeof(*ng_iface_units) * NBBY)
205 
206 /************************************************************************
207 			HELPER STUFF
208  ************************************************************************/
209 
210 /*
211  * Get the family descriptor from the family ID
212  */
213 static __inline__ iffam_p
214 get_iffam_from_af(sa_family_t family)
215 {
216 	iffam_p iffam;
217 	int k;
218 
219 	for (k = 0; k < NUM_FAMILIES; k++) {
220 		iffam = &gFamilies[k];
221 		if (iffam->family == family)
222 			return (iffam);
223 	}
224 	return (NULL);
225 }
226 
227 /*
228  * Get the family descriptor from the hook
229  */
230 static __inline__ iffam_p
231 get_iffam_from_hook(priv_p priv, hook_p hook)
232 {
233 	int k;
234 
235 	for (k = 0; k < NUM_FAMILIES; k++)
236 		if (priv->hooks[k] == hook)
237 			return (&gFamilies[k]);
238 	return (NULL);
239 }
240 
241 /*
242  * Get the hook from the iffam descriptor
243  */
244 
245 static __inline__ hook_p *
246 get_hook_from_iffam(priv_p priv, iffam_p iffam)
247 {
248 	return (&priv->hooks[iffam - gFamilies]);
249 }
250 
251 /*
252  * Get the iffam descriptor from the name
253  */
254 static __inline__ iffam_p
255 get_iffam_from_name(const char *name)
256 {
257 	iffam_p iffam;
258 	int k;
259 
260 	for (k = 0; k < NUM_FAMILIES; k++) {
261 		iffam = &gFamilies[k];
262 		if (!strcmp(iffam->hookname, name))
263 			return (iffam);
264 	}
265 	return (NULL);
266 }
267 
268 /*
269  * Find the first free unit number for a new interface.
270  * Increase the size of the unit bitmap as necessary.
271  */
272 static __inline__ int
273 ng_iface_get_unit(int *unit)
274 {
275 	int index, bit;
276 
277 	for (index = 0; index < ng_iface_units_len
278 	    && ng_iface_units[index] == 0; index++);
279 	if (index == ng_iface_units_len) {		/* extend array */
280 		int i, *newarray, newlen;
281 
282 		newlen = (2 * ng_iface_units_len) + 4;
283 		MALLOC(newarray, int *, newlen * sizeof(*ng_iface_units),
284 		    M_NETGRAPH, M_NOWAIT);
285 		if (newarray == NULL)
286 			return (ENOMEM);
287 		bcopy(ng_iface_units, newarray,
288 		    ng_iface_units_len * sizeof(*ng_iface_units));
289 		for (i = ng_iface_units_len; i < newlen; i++)
290 			newarray[i] = ~0;
291 		if (ng_iface_units != NULL)
292 			FREE(ng_iface_units, M_NETGRAPH);
293 		ng_iface_units = newarray;
294 		ng_iface_units_len = newlen;
295 	}
296 	bit = ffs(ng_iface_units[index]) - 1;
297 	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
298 	    ("%s: word=%d bit=%d", __FUNCTION__, ng_iface_units[index], bit));
299 	ng_iface_units[index] &= ~(1 << bit);
300 	*unit = (index * UNITS_BITSPERWORD) + bit;
301 	return (0);
302 }
303 
304 /*
305  * Free a no longer needed unit number.
306  */
307 static __inline__ void
308 ng_iface_free_unit(int unit)
309 {
310 	int index, bit;
311 
312 	index = unit / UNITS_BITSPERWORD;
313 	bit = unit % UNITS_BITSPERWORD;
314 	KASSERT(index < ng_iface_units_len,
315 	    ("%s: unit=%d len=%d", __FUNCTION__, unit, ng_iface_units_len));
316 	KASSERT((ng_iface_units[index] & (1 << bit)) == 0,
317 	    ("%s: unit=%d is free", __FUNCTION__, unit));
318 	ng_iface_units[index] |= (1 << bit);
319 	/*
320 	 * XXX We could think about reducing the size of ng_iface_units[]
321 	 * XXX here if the last portion is all ones
322 	 */
323 }
324 
325 /************************************************************************
326 			INTERFACE STUFF
327  ************************************************************************/
328 
329 /*
330  * Process an ioctl for the virtual interface
331  */
332 static int
333 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
334 {
335 	struct ifreq *const ifr = (struct ifreq *) data;
336 	int s, error = 0;
337 
338 #ifdef DEBUG
339 	ng_iface_print_ioctl(ifp, command, data);
340 #endif
341 	s = splimp();
342 	switch (command) {
343 
344 	/* These two are mostly handled at a higher layer */
345 	case SIOCSIFADDR:
346 		ifp->if_flags |= (IFF_UP | IFF_RUNNING);
347 		ifp->if_flags &= ~(IFF_OACTIVE);
348 		break;
349 	case SIOCGIFADDR:
350 		break;
351 
352 	/* Set flags */
353 	case SIOCSIFFLAGS:
354 		/*
355 		 * If the interface is marked up and stopped, then start it.
356 		 * If it is marked down and running, then stop it.
357 		 */
358 		if (ifr->ifr_flags & IFF_UP) {
359 			if (!(ifp->if_flags & IFF_RUNNING)) {
360 				ifp->if_flags &= ~(IFF_OACTIVE);
361 				ifp->if_flags |= IFF_RUNNING;
362 			}
363 		} else {
364 			if (ifp->if_flags & IFF_RUNNING)
365 				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
366 		}
367 		break;
368 
369 	/* Set the interface MTU */
370 	case SIOCSIFMTU:
371 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
372 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
373 			error = EINVAL;
374 		else
375 			ifp->if_mtu = ifr->ifr_mtu;
376 		break;
377 
378 	/* Stuff that's not supported */
379 	case SIOCADDMULTI:
380 	case SIOCDELMULTI:
381 		error = 0;
382 		break;
383 	case SIOCSIFPHYS:
384 		error = EOPNOTSUPP;
385 		break;
386 
387 	default:
388 		error = EINVAL;
389 		break;
390 	}
391 	(void) splx(s);
392 	return (error);
393 }
394 
395 /*
396  * This routine is called to deliver a packet out the interface.
397  * We simply look at the address family and relay the packet to
398  * the corresponding hook, if it exists and is connected.
399  */
400 
401 static int
402 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
403 		struct sockaddr *dst, struct rtentry *rt0)
404 {
405 	const priv_p priv = (priv_p) ifp->if_softc;
406 	const iffam_p iffam = get_iffam_from_af(dst->sa_family);
407 	meta_p meta = NULL;
408 	int len, error = 0;
409 
410 	/* Check interface flags */
411 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
412 		m_freem(m);
413 		return (ENETDOWN);
414 	}
415 
416 	/* BPF writes need to be handled specially */
417 	if (dst->sa_family == AF_UNSPEC) {
418 		if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
419 			return (ENOBUFS);
420 		dst->sa_family = (sa_family_t)*mtod(m, int32_t *);
421 		m->m_data += 4;
422 		m->m_len -= 4;
423 		m->m_pkthdr.len -= 4;
424 	}
425 
426 	/* Berkeley packet filter */
427 	ng_iface_bpftap(ifp, m, dst->sa_family);
428 
429 	/* Check address family to determine hook (if known) */
430 	if (iffam == NULL) {
431 		m_freem(m);
432 		log(LOG_WARNING, "%s%d: can't handle af%d\n",
433 		       ifp->if_name, ifp->if_unit, (int)dst->sa_family);
434 		return (EAFNOSUPPORT);
435 	}
436 
437 	/* Copy length before the mbuf gets invalidated */
438 	len = m->m_pkthdr.len;
439 
440 	/* Send packet; if hook is not connected, mbuf will get freed. */
441 	NG_SEND_DATA(error, *get_hook_from_iffam(priv, iffam), m, meta);
442 
443 	/* Update stats */
444 	if (error == 0) {
445 		ifp->if_obytes += len;
446 		ifp->if_opackets++;
447 	}
448 	return (error);
449 }
450 
451 /*
452  * This routine should never be called
453  */
454 
455 static void
456 ng_iface_start(struct ifnet *ifp)
457 {
458 	printf("%s%d: %s called?", ifp->if_name, ifp->if_unit, __FUNCTION__);
459 }
460 
461 /*
462  * Flash a packet by the BPF (requires prepending 4 byte AF header)
463  * Note the phoney mbuf; this is OK because BPF treats it read-only.
464  */
465 static void
466 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
467 {
468 	int32_t family4 = (int32_t)family;
469 	struct mbuf m0;
470 
471 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __FUNCTION__));
472 	if (ifp->if_bpf != NULL) {
473 		bzero(&m0, sizeof(m0));
474 		m0.m_next = m;
475 		m0.m_len = sizeof(family4);
476 		m0.m_data = (char *)&family4;
477 		bpf_mtap(ifp, &m0);
478 	}
479 }
480 
481 #ifdef DEBUG
482 /*
483  * Display an ioctl to the virtual interface
484  */
485 
486 static void
487 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
488 {
489 	char   *str;
490 
491 	switch (command & IOC_DIRMASK) {
492 	case IOC_VOID:
493 		str = "IO";
494 		break;
495 	case IOC_OUT:
496 		str = "IOR";
497 		break;
498 	case IOC_IN:
499 		str = "IOW";
500 		break;
501 	case IOC_INOUT:
502 		str = "IORW";
503 		break;
504 	default:
505 		str = "IO??";
506 	}
507 	log(LOG_DEBUG, "%s%d: %s('%c', %d, char[%d])\n",
508 	       ifp->if_name, ifp->if_unit,
509 	       str,
510 	       IOCGROUP(command),
511 	       command & 0xff,
512 	       IOCPARM_LEN(command));
513 }
514 #endif /* DEBUG */
515 
516 /************************************************************************
517 			NETGRAPH NODE STUFF
518  ************************************************************************/
519 
520 /*
521  * Constructor for a node
522  */
523 static int
524 ng_iface_constructor(node_p node)
525 {
526 	char ifname[NG_IFACE_IFACE_NAME_MAX + 1];
527 	struct ifnet *ifp;
528 	priv_p priv;
529 	int error = 0;
530 
531 	/* Allocate node and interface private structures */
532 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT|M_ZERO);
533 	if (priv == NULL)
534 		return (ENOMEM);
535 	MALLOC(ifp, struct ifnet *, sizeof(*ifp), M_NETGRAPH, M_NOWAIT|M_ZERO);
536 	if (ifp == NULL) {
537 		FREE(priv, M_NETGRAPH);
538 		return (ENOMEM);
539 	}
540 
541 	/* Link them together */
542 	ifp->if_softc = priv;
543 	priv->ifp = ifp;
544 
545 	/* Get an interface unit number */
546 	if ((error = ng_iface_get_unit(&priv->unit)) != 0) {
547 		FREE(ifp, M_NETGRAPH);
548 		FREE(priv, M_NETGRAPH);
549 		return (error);
550 	}
551 
552 	/* Link together node and private info */
553 	node->private = priv;
554 	priv->node = node;
555 
556 	/* Initialize interface structure */
557 	ifp->if_name = NG_IFACE_IFACE_NAME;
558 	ifp->if_unit = priv->unit;
559 	ifp->if_output = ng_iface_output;
560 	ifp->if_start = ng_iface_start;
561 	ifp->if_ioctl = ng_iface_ioctl;
562 	ifp->if_watchdog = NULL;
563 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
564 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
565 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
566 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
567 	ifp->if_addrlen = 0;			/* XXX */
568 	ifp->if_hdrlen = 0;			/* XXX */
569 	ifp->if_baudrate = 64000;		/* XXX */
570 	TAILQ_INIT(&ifp->if_addrhead);
571 
572 	/* Give this node the same name as the interface (if possible) */
573 	bzero(ifname, sizeof(ifname));
574 	snprintf(ifname, sizeof(ifname), "%s%d", ifp->if_name, ifp->if_unit);
575 	if (ng_name_node(node, ifname) != 0)
576 		log(LOG_WARNING, "%s: can't acquire netgraph name\n", ifname);
577 
578 	/* Attach the interface */
579 	if_attach(ifp);
580 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
581 
582 	/* Done */
583 	return (0);
584 }
585 
586 /*
587  * Give our ok for a hook to be added
588  */
589 static int
590 ng_iface_newhook(node_p node, hook_p hook, const char *name)
591 {
592 	const iffam_p iffam = get_iffam_from_name(name);
593 	hook_p *hookptr;
594 
595 	if (iffam == NULL)
596 		return (EPFNOSUPPORT);
597 	hookptr = get_hook_from_iffam((priv_p) node->private, iffam);
598 	if (*hookptr != NULL)
599 		return (EISCONN);
600 	*hookptr = hook;
601 	return (0);
602 }
603 
604 /*
605  * Receive a control message
606  */
607 static int
608 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
609 {
610 	const priv_p priv = node->private;
611 	struct ifnet *const ifp = priv->ifp;
612 	struct ng_mesg *resp = NULL;
613 	int error = 0;
614 	struct ng_mesg *msg;
615 
616 	NGI_GET_MSG(item, msg);
617 	switch (msg->header.typecookie) {
618 	case NGM_IFACE_COOKIE:
619 		switch (msg->header.cmd) {
620 		case NGM_IFACE_GET_IFNAME:
621 		    {
622 			struct ng_iface_ifname *arg;
623 
624 			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
625 			if (resp == NULL) {
626 				error = ENOMEM;
627 				break;
628 			}
629 			arg = (struct ng_iface_ifname *)resp->data;
630 			snprintf(arg->ngif_name, sizeof(arg->ngif_name),
631 			    "%s%d", ifp->if_name, ifp->if_unit);
632 			break;
633 		    }
634 
635 		case NGM_IFACE_POINT2POINT:
636 		case NGM_IFACE_BROADCAST:
637 		    {
638 
639 			/* Deny request if interface is UP */
640 			if ((ifp->if_flags & IFF_UP) != 0)
641 				return (EBUSY);
642 
643 			/* Change flags */
644 			switch (msg->header.cmd) {
645 			case NGM_IFACE_POINT2POINT:
646 				ifp->if_flags |= IFF_POINTOPOINT;
647 				ifp->if_flags &= ~IFF_BROADCAST;
648 				break;
649 			case NGM_IFACE_BROADCAST:
650 				ifp->if_flags &= ~IFF_POINTOPOINT;
651 				ifp->if_flags |= IFF_BROADCAST;
652 				break;
653 			}
654 			break;
655 		    }
656 
657 		default:
658 			error = EINVAL;
659 			break;
660 		}
661 		break;
662 	case NGM_CISCO_COOKIE:
663 		switch (msg->header.cmd) {
664 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
665 		    {
666 			struct ifaddr *ifa;
667 
668 			/* Return the first configured IP address */
669 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
670 				struct ng_cisco_ipaddr *ips;
671 
672 				if (ifa->ifa_addr->sa_family != AF_INET)
673 					continue;
674 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
675 				if (resp == NULL) {
676 					error = ENOMEM;
677 					break;
678 				}
679 				ips = (struct ng_cisco_ipaddr *)resp->data;
680 				ips->ipaddr = ((struct sockaddr_in *)
681 						ifa->ifa_addr)->sin_addr;
682 				ips->netmask = ((struct sockaddr_in *)
683 						ifa->ifa_netmask)->sin_addr;
684 				break;
685 			}
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 	default:
698 		error = EINVAL;
699 		break;
700 	}
701 	NG_RESPOND_MSG(error, node, item, resp);
702 	NG_FREE_MSG(msg);
703 	return (error);
704 }
705 
706 /*
707  * Recive data from a hook. Pass the packet to the correct input routine.
708  */
709 static int
710 ng_iface_rcvdata(hook_p hook, item_p item)
711 {
712 	const priv_p priv = hook->node->private;
713 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
714 	struct ifnet *const ifp = priv->ifp;
715 	struct mbuf *m;
716 
717 	NGI_GET_M(item, m);
718 	NG_FREE_ITEM(item);
719 	/* Sanity checks */
720 	KASSERT(iffam != NULL, ("%s: iffam", __FUNCTION__));
721 	KASSERT(m->m_flags & M_PKTHDR, ("%s: not pkthdr", __FUNCTION__));
722 	if (m == NULL)
723 		return (EINVAL);
724 	if ((ifp->if_flags & IFF_UP) == 0) {
725 		NG_FREE_M(m);
726 		return (ENETDOWN);
727 	}
728 
729 	/* Update interface stats */
730 	ifp->if_ipackets++;
731 	ifp->if_ibytes += m->m_pkthdr.len;
732 
733 	/* Note receiving interface */
734 	m->m_pkthdr.rcvif = ifp;
735 
736 	/* Berkeley packet filter */
737 	ng_iface_bpftap(ifp, m, iffam->family);
738 
739 	/* Send packet */
740 	return family_enqueue(iffam->family, m);
741 }
742 
743 /*
744  * Shutdown and remove the node and its associated interface.
745  */
746 static int
747 ng_iface_shutdown(node_p node)
748 {
749 	const priv_p priv = node->private;
750 
751 	bpfdetach(priv->ifp);
752 	if_detach(priv->ifp);
753 	priv->ifp = NULL;
754 	ng_iface_free_unit(priv->unit);
755 	FREE(priv, M_NETGRAPH);
756 	node->private = NULL;
757 	ng_unref(node);
758 	return (0);
759 }
760 
761 /*
762  * Hook disconnection. Note that we do *not* shutdown when all
763  * hooks have been disconnected.
764  */
765 static int
766 ng_iface_disconnect(hook_p hook)
767 {
768 	const priv_p priv = hook->node->private;
769 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
770 
771 	if (iffam == NULL)
772 		panic(__FUNCTION__);
773 	*get_hook_from_iffam(priv, iffam) = NULL;
774 	return (0);
775 }
776 
777