xref: /freebsd/sys/netgraph/ng_iface.c (revision 81d1ffee089aab2652954909acbe6aadd8a1a72c)
1 /*
2  * ng_iface.c
3  *
4  * Copyright (c) 1996-1999 Whistle Communications, Inc.
5  * All rights reserved.
6  *
7  * Subject to the following obligations and disclaimer of warranty, use and
8  * redistribution of this software, in source or object code forms, with or
9  * without modifications are expressly permitted by Whistle Communications;
10  * provided, however, that:
11  * 1. Any and all reproductions of the source or object code must include the
12  *    copyright notice above and the following disclaimer of warranties; and
13  * 2. No rights are granted, in any manner or form, to use Whistle
14  *    Communications, Inc. trademarks, including the mark "WHISTLE
15  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
16  *    such appears in the above copyright notice or in the software.
17  *
18  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
19  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
20  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
21  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
23  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
24  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
25  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
26  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
27  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
28  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
29  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
30  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
34  * OF SUCH DAMAGE.
35  *
36  * Author: Archie Cobbs <archie@freebsd.org>
37  *
38  * $FreeBSD$
39  * $Whistle: ng_iface.c,v 1.33 1999/11/01 09:24:51 julian Exp $
40  */
41 
42 /*
43  * This node is also a system networking interface. It has
44  * a hook for each protocol (IP, AppleTalk, IPX, etc). Packets
45  * are simply relayed between the interface and the hooks.
46  *
47  * Interfaces are named ng0, ng1, etc.  New nodes take the
48  * first available interface name.
49  *
50  * This node also includes Berkeley packet filter support.
51  */
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/errno.h>
56 #include <sys/kernel.h>
57 #include <sys/malloc.h>
58 #include <sys/mbuf.h>
59 #include <sys/errno.h>
60 #include <sys/random.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/bpf.h>
69 #include <net/netisr.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 #ifdef NG_SEPARATE_MALLOC
80 MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node ");
81 #else
82 #define M_NETGRAPH_IFACE M_NETGRAPH
83 #endif
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 };
101 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*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 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
116 			struct sockaddr *dst, struct rtentry *rt0);
117 static void	ng_iface_bpftap(struct ifnet *ifp,
118 			struct mbuf *m, sa_family_t family);
119 #ifdef DEBUG
120 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
121 #endif
122 
123 /* Netgraph methods */
124 static ng_constructor_t	ng_iface_constructor;
125 static ng_rcvmsg_t	ng_iface_rcvmsg;
126 static ng_shutdown_t	ng_iface_shutdown;
127 static ng_newhook_t	ng_iface_newhook;
128 static ng_rcvdata_t	ng_iface_rcvdata;
129 static ng_disconnect_t	ng_iface_disconnect;
130 
131 /* Helper stuff */
132 static iffam_p	get_iffam_from_af(sa_family_t family);
133 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
134 static iffam_p	get_iffam_from_name(const char *name);
135 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
136 
137 /* Parse type for struct ng_iface_ifname */
138 static const struct ng_parse_fixedstring_info ng_iface_ifname_info = {
139 	NG_IFACE_IFACE_NAME_MAX + 1
140 };
141 static const struct ng_parse_type ng_iface_ifname_type = {
142 	&ng_parse_fixedstring_type,
143 	&ng_iface_ifname_info
144 };
145 
146 /* Parse type for struct ng_cisco_ipaddr */
147 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
148 	= NG_CISCO_IPADDR_TYPE_INFO;
149 static const struct ng_parse_type ng_cisco_ipaddr_type = {
150 	&ng_parse_struct_type,
151 	&ng_cisco_ipaddr_type_fields
152 };
153 
154 /* List of commands and how to convert arguments to/from ASCII */
155 static const struct ng_cmdlist ng_iface_cmds[] = {
156 	{
157 	  NGM_IFACE_COOKIE,
158 	  NGM_IFACE_GET_IFNAME,
159 	  "getifname",
160 	  NULL,
161 	  &ng_iface_ifname_type
162 	},
163 	{
164 	  NGM_IFACE_COOKIE,
165 	  NGM_IFACE_POINT2POINT,
166 	  "point2point",
167 	  NULL,
168 	  NULL
169 	},
170 	{
171 	  NGM_IFACE_COOKIE,
172 	  NGM_IFACE_BROADCAST,
173 	  "broadcast",
174 	  NULL,
175 	  NULL
176 	},
177 	{
178 	  NGM_CISCO_COOKIE,
179 	  NGM_CISCO_GET_IPADDR,
180 	  "getipaddr",
181 	  NULL,
182 	  &ng_cisco_ipaddr_type
183 	},
184 	{ 0 }
185 };
186 
187 /* Node type descriptor */
188 static struct ng_type typestruct = {
189 	NG_ABI_VERSION,
190 	NG_IFACE_NODE_TYPE,
191 	NULL,
192 	ng_iface_constructor,
193 	ng_iface_rcvmsg,
194 	ng_iface_shutdown,
195 	ng_iface_newhook,
196 	NULL,
197 	NULL,
198 	ng_iface_rcvdata,
199 	ng_iface_disconnect,
200 	ng_iface_cmds
201 };
202 NETGRAPH_INIT(iface, &typestruct);
203 
204 /* We keep a bitmap indicating which unit numbers are free.
205    One means the unit number is free, zero means it's taken. */
206 static int	*ng_iface_units = NULL;
207 static int	ng_iface_units_len = 0;
208 static int	ng_units_in_use = 0;
209 
210 #define UNITS_BITSPERWORD	(sizeof(*ng_iface_units) * NBBY)
211 
212 /************************************************************************
213 			HELPER STUFF
214  ************************************************************************/
215 
216 /*
217  * Get the family descriptor from the family ID
218  */
219 static __inline__ iffam_p
220 get_iffam_from_af(sa_family_t family)
221 {
222 	iffam_p iffam;
223 	int k;
224 
225 	for (k = 0; k < NUM_FAMILIES; k++) {
226 		iffam = &gFamilies[k];
227 		if (iffam->family == family)
228 			return (iffam);
229 	}
230 	return (NULL);
231 }
232 
233 /*
234  * Get the family descriptor from the hook
235  */
236 static __inline__ iffam_p
237 get_iffam_from_hook(priv_p priv, hook_p hook)
238 {
239 	int k;
240 
241 	for (k = 0; k < NUM_FAMILIES; k++)
242 		if (priv->hooks[k] == hook)
243 			return (&gFamilies[k]);
244 	return (NULL);
245 }
246 
247 /*
248  * Get the hook from the iffam descriptor
249  */
250 
251 static __inline__ hook_p *
252 get_hook_from_iffam(priv_p priv, iffam_p iffam)
253 {
254 	return (&priv->hooks[iffam - gFamilies]);
255 }
256 
257 /*
258  * Get the iffam descriptor from the name
259  */
260 static __inline__ iffam_p
261 get_iffam_from_name(const char *name)
262 {
263 	iffam_p iffam;
264 	int k;
265 
266 	for (k = 0; k < NUM_FAMILIES; k++) {
267 		iffam = &gFamilies[k];
268 		if (!strcmp(iffam->hookname, name))
269 			return (iffam);
270 	}
271 	return (NULL);
272 }
273 
274 /*
275  * Find the first free unit number for a new interface.
276  * Increase the size of the unit bitmap as necessary.
277  */
278 static __inline__ int
279 ng_iface_get_unit(int *unit)
280 {
281 	int index, bit;
282 
283 	for (index = 0; index < ng_iface_units_len
284 	    && ng_iface_units[index] == 0; index++);
285 	if (index == ng_iface_units_len) {		/* extend array */
286 		int i, *newarray, newlen;
287 
288 		newlen = (2 * ng_iface_units_len) + 4;
289 		MALLOC(newarray, int *, newlen * sizeof(*ng_iface_units),
290 		    M_NETGRAPH_IFACE, M_NOWAIT);
291 		if (newarray == NULL)
292 			return (ENOMEM);
293 		bcopy(ng_iface_units, newarray,
294 		    ng_iface_units_len * sizeof(*ng_iface_units));
295 		for (i = ng_iface_units_len; i < newlen; i++)
296 			newarray[i] = ~0;
297 		if (ng_iface_units != NULL)
298 			FREE(ng_iface_units, M_NETGRAPH_IFACE);
299 		ng_iface_units = newarray;
300 		ng_iface_units_len = newlen;
301 	}
302 	bit = ffs(ng_iface_units[index]) - 1;
303 	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
304 	    ("%s: word=%d bit=%d", __func__, ng_iface_units[index], bit));
305 	ng_iface_units[index] &= ~(1 << bit);
306 	*unit = (index * UNITS_BITSPERWORD) + bit;
307 	ng_units_in_use++;
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 	 * XXX At least free it if no more units.
330 	 * Needed if we are to eventually be able to unload.
331 	 */
332 	ng_units_in_use--;
333 	if (ng_units_in_use == 0) { /* XXX make SMP safe */
334 		FREE(ng_iface_units, M_NETGRAPH_IFACE);
335 		ng_iface_units_len = 0;
336 		ng_iface_units = NULL;
337 	}
338 }
339 
340 /************************************************************************
341 			INTERFACE STUFF
342  ************************************************************************/
343 
344 /*
345  * Process an ioctl for the virtual interface
346  */
347 static int
348 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
349 {
350 	struct ifreq *const ifr = (struct ifreq *) data;
351 	int s, error = 0;
352 
353 #ifdef DEBUG
354 	ng_iface_print_ioctl(ifp, command, data);
355 #endif
356 	s = splimp();
357 	switch (command) {
358 
359 	/* These two are mostly handled at a higher layer */
360 	case SIOCSIFADDR:
361 		ifp->if_flags |= (IFF_UP | IFF_RUNNING);
362 		ifp->if_flags &= ~(IFF_OACTIVE);
363 		break;
364 	case SIOCGIFADDR:
365 		break;
366 
367 	/* Set flags */
368 	case SIOCSIFFLAGS:
369 		/*
370 		 * If the interface is marked up and stopped, then start it.
371 		 * If it is marked down and running, then stop it.
372 		 */
373 		if (ifr->ifr_flags & IFF_UP) {
374 			if (!(ifp->if_flags & IFF_RUNNING)) {
375 				ifp->if_flags &= ~(IFF_OACTIVE);
376 				ifp->if_flags |= IFF_RUNNING;
377 			}
378 		} else {
379 			if (ifp->if_flags & IFF_RUNNING)
380 				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
381 		}
382 		break;
383 
384 	/* Set the interface MTU */
385 	case SIOCSIFMTU:
386 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
387 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
388 			error = EINVAL;
389 		else
390 			ifp->if_mtu = ifr->ifr_mtu;
391 		break;
392 
393 	/* Stuff that's not supported */
394 	case SIOCADDMULTI:
395 	case SIOCDELMULTI:
396 		error = 0;
397 		break;
398 	case SIOCSIFPHYS:
399 		error = EOPNOTSUPP;
400 		break;
401 
402 	default:
403 		error = EINVAL;
404 		break;
405 	}
406 	(void) splx(s);
407 	return (error);
408 }
409 
410 /*
411  * This routine is called to deliver a packet out the interface.
412  * We simply look at the address family and relay the packet to
413  * the corresponding hook, if it exists and is connected.
414  */
415 
416 static int
417 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
418 		struct sockaddr *dst, struct rtentry *rt0)
419 {
420 	const priv_p priv = (priv_p) ifp->if_softc;
421 	const iffam_p iffam = get_iffam_from_af(dst->sa_family);
422 	meta_p meta = NULL;
423 	int len, error = 0;
424 
425 	/* Check interface flags */
426 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
427 		m_freem(m);
428 		return (ENETDOWN);
429 	}
430 
431 	/* BPF writes need to be handled specially */
432 	if (dst->sa_family == AF_UNSPEC) {
433 		if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
434 			return (ENOBUFS);
435 		dst->sa_family = (sa_family_t)*mtod(m, int32_t *);
436 		m->m_data += 4;
437 		m->m_len -= 4;
438 		m->m_pkthdr.len -= 4;
439 	}
440 
441 	/* Berkeley packet filter */
442 	ng_iface_bpftap(ifp, m, dst->sa_family);
443 
444 	/* Check address family to determine hook (if known) */
445 	if (iffam == NULL) {
446 		m_freem(m);
447 		log(LOG_WARNING, "%s%d: can't handle af%d\n",
448 		       ifp->if_name, ifp->if_unit, (int)dst->sa_family);
449 		return (EAFNOSUPPORT);
450 	}
451 
452 	/* Copy length before the mbuf gets invalidated */
453 	len = m->m_pkthdr.len;
454 
455 	/* Send packet; if hook is not connected, mbuf will get freed. */
456 	NG_SEND_DATA(error, *get_hook_from_iffam(priv, iffam), m, meta);
457 
458 	/* Update stats */
459 	if (error == 0) {
460 		ifp->if_obytes += len;
461 		ifp->if_opackets++;
462 	}
463 	return (error);
464 }
465 
466 /*
467  * This routine should never be called
468  */
469 
470 static void
471 ng_iface_start(struct ifnet *ifp)
472 {
473 	if_printf(ifp, "%s called?", __func__);
474 }
475 
476 /*
477  * Flash a packet by the BPF (requires prepending 4 byte AF header)
478  * Note the phoney mbuf; this is OK because BPF treats it read-only.
479  */
480 static void
481 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
482 {
483 	int32_t family4 = (int32_t)family;
484 	struct mbuf m0;
485 
486 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
487 	if (ifp->if_bpf != NULL) {
488 		bzero(&m0, sizeof(m0));
489 		m0.m_next = m;
490 		m0.m_len = sizeof(family4);
491 		m0.m_data = (char *)&family4;
492 		BPF_MTAP(ifp, &m0);
493 	}
494 }
495 
496 #ifdef DEBUG
497 /*
498  * Display an ioctl to the virtual interface
499  */
500 
501 static void
502 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
503 {
504 	char   *str;
505 
506 	switch (command & IOC_DIRMASK) {
507 	case IOC_VOID:
508 		str = "IO";
509 		break;
510 	case IOC_OUT:
511 		str = "IOR";
512 		break;
513 	case IOC_IN:
514 		str = "IOW";
515 		break;
516 	case IOC_INOUT:
517 		str = "IORW";
518 		break;
519 	default:
520 		str = "IO??";
521 	}
522 	log(LOG_DEBUG, "%s%d: %s('%c', %d, char[%d])\n",
523 	       ifp->if_name, ifp->if_unit,
524 	       str,
525 	       IOCGROUP(command),
526 	       command & 0xff,
527 	       IOCPARM_LEN(command));
528 }
529 #endif /* DEBUG */
530 
531 /************************************************************************
532 			NETGRAPH NODE STUFF
533  ************************************************************************/
534 
535 /*
536  * Constructor for a node
537  */
538 static int
539 ng_iface_constructor(node_p node)
540 {
541 	char ifname[NG_IFACE_IFACE_NAME_MAX + 1];
542 	struct ifnet *ifp;
543 	priv_p priv;
544 	int error = 0;
545 
546 	/* Allocate node and interface private structures */
547 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_IFACE, M_NOWAIT|M_ZERO);
548 	if (priv == NULL)
549 		return (ENOMEM);
550 	MALLOC(ifp, struct ifnet *, sizeof(*ifp), M_NETGRAPH_IFACE, M_NOWAIT|M_ZERO);
551 	if (ifp == NULL) {
552 		FREE(priv, M_NETGRAPH_IFACE);
553 		return (ENOMEM);
554 	}
555 
556 	/* Link them together */
557 	ifp->if_softc = priv;
558 	priv->ifp = ifp;
559 
560 	/* Get an interface unit number */
561 	if ((error = ng_iface_get_unit(&priv->unit)) != 0) {
562 		FREE(ifp, M_NETGRAPH_IFACE);
563 		FREE(priv, M_NETGRAPH_IFACE);
564 		return (error);
565 	}
566 
567 	/* Link together node and private info */
568 	NG_NODE_SET_PRIVATE(node, priv);
569 	priv->node = node;
570 
571 	/* Initialize interface structure */
572 	ifp->if_name = NG_IFACE_IFACE_NAME;
573 	ifp->if_unit = priv->unit;
574 	ifp->if_output = ng_iface_output;
575 	ifp->if_start = ng_iface_start;
576 	ifp->if_ioctl = ng_iface_ioctl;
577 	ifp->if_watchdog = NULL;
578 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
579 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
580 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
581 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
582 	ifp->if_addrlen = 0;			/* XXX */
583 	ifp->if_hdrlen = 0;			/* XXX */
584 	ifp->if_baudrate = 64000;		/* XXX */
585 	TAILQ_INIT(&ifp->if_addrhead);
586 
587 	/* Give this node the same name as the interface (if possible) */
588 	bzero(ifname, sizeof(ifname));
589 	snprintf(ifname, sizeof(ifname), "%s%d", ifp->if_name, ifp->if_unit);
590 	if (ng_name_node(node, ifname) != 0)
591 		log(LOG_WARNING, "%s: can't acquire netgraph name\n", ifname);
592 
593 	/* Attach the interface */
594 	if_attach(ifp);
595 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
596 
597 	/* Done */
598 	return (0);
599 }
600 
601 /*
602  * Give our ok for a hook to be added
603  */
604 static int
605 ng_iface_newhook(node_p node, hook_p hook, const char *name)
606 {
607 	const iffam_p iffam = get_iffam_from_name(name);
608 	hook_p *hookptr;
609 
610 	if (iffam == NULL)
611 		return (EPFNOSUPPORT);
612 	hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
613 	if (*hookptr != NULL)
614 		return (EISCONN);
615 	*hookptr = hook;
616 	return (0);
617 }
618 
619 /*
620  * Receive a control message
621  */
622 static int
623 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
624 {
625 	const priv_p priv = NG_NODE_PRIVATE(node);
626 	struct ifnet *const ifp = priv->ifp;
627 	struct ng_mesg *resp = NULL;
628 	int error = 0;
629 	struct ng_mesg *msg;
630 
631 	NGI_GET_MSG(item, msg);
632 	switch (msg->header.typecookie) {
633 	case NGM_IFACE_COOKIE:
634 		switch (msg->header.cmd) {
635 		case NGM_IFACE_GET_IFNAME:
636 		    {
637 			struct ng_iface_ifname *arg;
638 
639 			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
640 			if (resp == NULL) {
641 				error = ENOMEM;
642 				break;
643 			}
644 			arg = (struct ng_iface_ifname *)resp->data;
645 			snprintf(arg->ngif_name, sizeof(arg->ngif_name),
646 			    "%s%d", ifp->if_name, ifp->if_unit);
647 			break;
648 		    }
649 
650 		case NGM_IFACE_POINT2POINT:
651 		case NGM_IFACE_BROADCAST:
652 		    {
653 
654 			/* Deny request if interface is UP */
655 			if ((ifp->if_flags & IFF_UP) != 0)
656 				return (EBUSY);
657 
658 			/* Change flags */
659 			switch (msg->header.cmd) {
660 			case NGM_IFACE_POINT2POINT:
661 				ifp->if_flags |= IFF_POINTOPOINT;
662 				ifp->if_flags &= ~IFF_BROADCAST;
663 				break;
664 			case NGM_IFACE_BROADCAST:
665 				ifp->if_flags &= ~IFF_POINTOPOINT;
666 				ifp->if_flags |= IFF_BROADCAST;
667 				break;
668 			}
669 			break;
670 		    }
671 
672 		default:
673 			error = EINVAL;
674 			break;
675 		}
676 		break;
677 	case NGM_CISCO_COOKIE:
678 		switch (msg->header.cmd) {
679 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
680 		    {
681 			struct ifaddr *ifa;
682 
683 			/* Return the first configured IP address */
684 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
685 				struct ng_cisco_ipaddr *ips;
686 
687 				if (ifa->ifa_addr->sa_family != AF_INET)
688 					continue;
689 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
690 				if (resp == NULL) {
691 					error = ENOMEM;
692 					break;
693 				}
694 				ips = (struct ng_cisco_ipaddr *)resp->data;
695 				ips->ipaddr = ((struct sockaddr_in *)
696 						ifa->ifa_addr)->sin_addr;
697 				ips->netmask = ((struct sockaddr_in *)
698 						ifa->ifa_netmask)->sin_addr;
699 				break;
700 			}
701 
702 			/* No IP addresses on this interface? */
703 			if (ifa == NULL)
704 				error = EADDRNOTAVAIL;
705 			break;
706 		    }
707 		default:
708 			error = EINVAL;
709 			break;
710 		}
711 		break;
712 	default:
713 		error = EINVAL;
714 		break;
715 	}
716 	NG_RESPOND_MSG(error, node, item, resp);
717 	NG_FREE_MSG(msg);
718 	return (error);
719 }
720 
721 /*
722  * Recive data from a hook. Pass the packet to the correct input routine.
723  */
724 static int
725 ng_iface_rcvdata(hook_p hook, item_p item)
726 {
727 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
728 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
729 	struct ifnet *const ifp = priv->ifp;
730 	struct mbuf *m;
731 	int isr;
732 
733 	NGI_GET_M(item, m);
734 	NG_FREE_ITEM(item);
735 	/* Sanity checks */
736 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
737 	KASSERT(m->m_flags & M_PKTHDR, ("%s: not pkthdr", __func__));
738 	if (m == NULL)
739 		return (EINVAL);
740 	if ((ifp->if_flags & IFF_UP) == 0) {
741 		NG_FREE_M(m);
742 		return (ENETDOWN);
743 	}
744 
745 	/* Update interface stats */
746 	ifp->if_ipackets++;
747 	ifp->if_ibytes += m->m_pkthdr.len;
748 
749 	/* Note receiving interface */
750 	m->m_pkthdr.rcvif = ifp;
751 
752 	/* Berkeley packet filter */
753 	ng_iface_bpftap(ifp, m, iffam->family);
754 
755 	/* Send packet */
756 	switch (iffam->family) {
757 #ifdef INET
758 	case AF_INET:
759 		isr = NETISR_IP;
760 		break;
761 #endif
762 #ifdef INET6
763 	case AF_INET6:
764 		isr = NETISR_IPV6;
765 		break;
766 #endif
767 #ifdef IPX
768 	case AF_IPX:
769 		isr = NETISR_IPX;
770 		break;
771 #endif
772 #ifdef NETATALK
773 	case AF_APPLETALK:
774 		isr = NETISR_ATALK2;
775 		break;
776 #endif
777 #ifdef NATM
778 	case AF_NATM:
779 		isr = NETISR_NATM;
780 		break;
781 #endif
782 #ifdef ATM_CORE
783 	case AF_ATM:
784 		isr = NETISR_ATM;
785 		break;
786 #endif
787 	default:
788 		m_freem(m);
789 		return (EAFNOSUPPORT);
790 	}
791 	/* First chunk of an mbuf contains good junk */
792 	if (harvest.point_to_point)
793 		random_harvest(m, 16, 3, 0, RANDOM_NET);
794 	netisr_dispatch(isr, m);
795 	return (0);
796 }
797 
798 /*
799  * Shutdown and remove the node and its associated interface.
800  */
801 static int
802 ng_iface_shutdown(node_p node)
803 {
804 	const priv_p priv = NG_NODE_PRIVATE(node);
805 
806 	bpfdetach(priv->ifp);
807 	if_detach(priv->ifp);
808 	FREE(priv->ifp, M_NETGRAPH_IFACE);
809 	priv->ifp = NULL;
810 	ng_iface_free_unit(priv->unit);
811 	FREE(priv, M_NETGRAPH_IFACE);
812 	NG_NODE_SET_PRIVATE(node, NULL);
813 	NG_NODE_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 = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
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