xref: /freebsd/sys/netgraph/ng_iface.c (revision 437ffe182391fbcd9826ce327abbd175515b687d)
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 "opt_atalk.h"
54 #include "opt_inet.h"
55 #include "opt_inet6.h"
56 #include "opt_ipx.h"
57 
58 #include <sys/param.h>
59 #include <sys/systm.h>
60 #include <sys/errno.h>
61 #include <sys/kernel.h>
62 #include <sys/malloc.h>
63 #include <sys/mbuf.h>
64 #include <sys/errno.h>
65 #include <sys/random.h>
66 #include <sys/sockio.h>
67 #include <sys/socket.h>
68 #include <sys/syslog.h>
69 #include <sys/libkern.h>
70 
71 #include <net/if.h>
72 #include <net/if_types.h>
73 #include <net/bpf.h>
74 #include <net/netisr.h>
75 
76 #include <netinet/in.h>
77 
78 #include <netgraph/ng_message.h>
79 #include <netgraph/netgraph.h>
80 #include <netgraph/ng_parse.h>
81 #include <netgraph/ng_iface.h>
82 #include <netgraph/ng_cisco.h>
83 
84 #ifdef NG_SEPARATE_MALLOC
85 MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node ");
86 #else
87 #define M_NETGRAPH_IFACE M_NETGRAPH
88 #endif
89 
90 /* This struct describes one address family */
91 struct iffam {
92 	sa_family_t	family;		/* Address family */
93 	const char	*hookname;	/* Name for hook */
94 };
95 typedef const struct iffam *iffam_p;
96 
97 /* List of address families supported by our interface */
98 const static struct iffam gFamilies[] = {
99 	{ AF_INET,	NG_IFACE_HOOK_INET	},
100 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
101 	{ AF_APPLETALK,	NG_IFACE_HOOK_ATALK	},
102 	{ AF_IPX,	NG_IFACE_HOOK_IPX	},
103 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
104 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
105 };
106 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
107 
108 /* Node private data */
109 struct ng_iface_private {
110 	struct	ifnet *ifp;		/* Our interface */
111 	int	unit;			/* Interface unit number */
112 	node_p	node;			/* Our netgraph node */
113 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
114 };
115 typedef struct ng_iface_private *priv_p;
116 
117 /* Interface methods */
118 static void	ng_iface_start(struct ifnet *ifp);
119 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
120 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
121 			struct sockaddr *dst, struct rtentry *rt0);
122 static void	ng_iface_bpftap(struct ifnet *ifp,
123 			struct mbuf *m, sa_family_t family);
124 #ifdef DEBUG
125 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
126 #endif
127 
128 /* Netgraph methods */
129 static ng_constructor_t	ng_iface_constructor;
130 static ng_rcvmsg_t	ng_iface_rcvmsg;
131 static ng_shutdown_t	ng_iface_shutdown;
132 static ng_newhook_t	ng_iface_newhook;
133 static ng_rcvdata_t	ng_iface_rcvdata;
134 static ng_disconnect_t	ng_iface_disconnect;
135 
136 /* Helper stuff */
137 static iffam_p	get_iffam_from_af(sa_family_t family);
138 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
139 static iffam_p	get_iffam_from_name(const char *name);
140 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
141 
142 /* Parse type for struct ng_iface_ifname */
143 static const struct ng_parse_fixedstring_info ng_iface_ifname_info = {
144 	NG_IFACE_IFACE_NAME_MAX + 1
145 };
146 static const struct ng_parse_type ng_iface_ifname_type = {
147 	&ng_parse_fixedstring_type,
148 	&ng_iface_ifname_info
149 };
150 
151 /* Parse type for struct ng_cisco_ipaddr */
152 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
153 	= NG_CISCO_IPADDR_TYPE_INFO;
154 static const struct ng_parse_type ng_cisco_ipaddr_type = {
155 	&ng_parse_struct_type,
156 	&ng_cisco_ipaddr_type_fields
157 };
158 
159 /* List of commands and how to convert arguments to/from ASCII */
160 static const struct ng_cmdlist ng_iface_cmds[] = {
161 	{
162 	  NGM_IFACE_COOKIE,
163 	  NGM_IFACE_GET_IFNAME,
164 	  "getifname",
165 	  NULL,
166 	  &ng_iface_ifname_type
167 	},
168 	{
169 	  NGM_IFACE_COOKIE,
170 	  NGM_IFACE_POINT2POINT,
171 	  "point2point",
172 	  NULL,
173 	  NULL
174 	},
175 	{
176 	  NGM_IFACE_COOKIE,
177 	  NGM_IFACE_BROADCAST,
178 	  "broadcast",
179 	  NULL,
180 	  NULL
181 	},
182 	{
183 	  NGM_CISCO_COOKIE,
184 	  NGM_CISCO_GET_IPADDR,
185 	  "getipaddr",
186 	  NULL,
187 	  &ng_cisco_ipaddr_type
188 	},
189 	{ 0 }
190 };
191 
192 /* Node type descriptor */
193 static struct ng_type typestruct = {
194 	NG_ABI_VERSION,
195 	NG_IFACE_NODE_TYPE,
196 	NULL,
197 	ng_iface_constructor,
198 	ng_iface_rcvmsg,
199 	ng_iface_shutdown,
200 	ng_iface_newhook,
201 	NULL,
202 	NULL,
203 	ng_iface_rcvdata,
204 	ng_iface_disconnect,
205 	ng_iface_cmds
206 };
207 NETGRAPH_INIT(iface, &typestruct);
208 
209 /* We keep a bitmap indicating which unit numbers are free.
210    One means the unit number is free, zero means it's taken. */
211 static int	*ng_iface_units = NULL;
212 static int	ng_iface_units_len = 0;
213 static int	ng_units_in_use = 0;
214 
215 #define UNITS_BITSPERWORD	(sizeof(*ng_iface_units) * NBBY)
216 
217 /************************************************************************
218 			HELPER STUFF
219  ************************************************************************/
220 
221 /*
222  * Get the family descriptor from the family ID
223  */
224 static __inline__ iffam_p
225 get_iffam_from_af(sa_family_t family)
226 {
227 	iffam_p iffam;
228 	int k;
229 
230 	for (k = 0; k < NUM_FAMILIES; k++) {
231 		iffam = &gFamilies[k];
232 		if (iffam->family == family)
233 			return (iffam);
234 	}
235 	return (NULL);
236 }
237 
238 /*
239  * Get the family descriptor from the hook
240  */
241 static __inline__ iffam_p
242 get_iffam_from_hook(priv_p priv, hook_p hook)
243 {
244 	int k;
245 
246 	for (k = 0; k < NUM_FAMILIES; k++)
247 		if (priv->hooks[k] == hook)
248 			return (&gFamilies[k]);
249 	return (NULL);
250 }
251 
252 /*
253  * Get the hook from the iffam descriptor
254  */
255 
256 static __inline__ hook_p *
257 get_hook_from_iffam(priv_p priv, iffam_p iffam)
258 {
259 	return (&priv->hooks[iffam - gFamilies]);
260 }
261 
262 /*
263  * Get the iffam descriptor from the name
264  */
265 static __inline__ iffam_p
266 get_iffam_from_name(const char *name)
267 {
268 	iffam_p iffam;
269 	int k;
270 
271 	for (k = 0; k < NUM_FAMILIES; k++) {
272 		iffam = &gFamilies[k];
273 		if (!strcmp(iffam->hookname, name))
274 			return (iffam);
275 	}
276 	return (NULL);
277 }
278 
279 /*
280  * Find the first free unit number for a new interface.
281  * Increase the size of the unit bitmap as necessary.
282  */
283 static __inline__ int
284 ng_iface_get_unit(int *unit)
285 {
286 	int index, bit;
287 
288 	for (index = 0; index < ng_iface_units_len
289 	    && ng_iface_units[index] == 0; index++);
290 	if (index == ng_iface_units_len) {		/* extend array */
291 		int i, *newarray, newlen;
292 
293 		newlen = (2 * ng_iface_units_len) + 4;
294 		MALLOC(newarray, int *, newlen * sizeof(*ng_iface_units),
295 		    M_NETGRAPH_IFACE, M_NOWAIT);
296 		if (newarray == NULL)
297 			return (ENOMEM);
298 		bcopy(ng_iface_units, newarray,
299 		    ng_iface_units_len * sizeof(*ng_iface_units));
300 		for (i = ng_iface_units_len; i < newlen; i++)
301 			newarray[i] = ~0;
302 		if (ng_iface_units != NULL)
303 			FREE(ng_iface_units, M_NETGRAPH_IFACE);
304 		ng_iface_units = newarray;
305 		ng_iface_units_len = newlen;
306 	}
307 	bit = ffs(ng_iface_units[index]) - 1;
308 	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
309 	    ("%s: word=%d bit=%d", __func__, ng_iface_units[index], bit));
310 	ng_iface_units[index] &= ~(1 << bit);
311 	*unit = (index * UNITS_BITSPERWORD) + bit;
312 	ng_units_in_use++;
313 	return (0);
314 }
315 
316 /*
317  * Free a no longer needed unit number.
318  */
319 static __inline__ void
320 ng_iface_free_unit(int unit)
321 {
322 	int index, bit;
323 
324 	index = unit / UNITS_BITSPERWORD;
325 	bit = unit % UNITS_BITSPERWORD;
326 	KASSERT(index < ng_iface_units_len,
327 	    ("%s: unit=%d len=%d", __func__, unit, ng_iface_units_len));
328 	KASSERT((ng_iface_units[index] & (1 << bit)) == 0,
329 	    ("%s: unit=%d is free", __func__, unit));
330 	ng_iface_units[index] |= (1 << bit);
331 	/*
332 	 * XXX We could think about reducing the size of ng_iface_units[]
333 	 * XXX here if the last portion is all ones
334 	 * XXX At least free it if no more units.
335 	 * Needed if we are to eventually be able to unload.
336 	 */
337 	ng_units_in_use--;
338 	if (ng_units_in_use == 0) { /* XXX make SMP safe */
339 		FREE(ng_iface_units, M_NETGRAPH_IFACE);
340 		ng_iface_units_len = 0;
341 		ng_iface_units = NULL;
342 	}
343 }
344 
345 /************************************************************************
346 			INTERFACE STUFF
347  ************************************************************************/
348 
349 /*
350  * Process an ioctl for the virtual interface
351  */
352 static int
353 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
354 {
355 	struct ifreq *const ifr = (struct ifreq *) data;
356 	int s, error = 0;
357 
358 #ifdef DEBUG
359 	ng_iface_print_ioctl(ifp, command, data);
360 #endif
361 	s = splimp();
362 	switch (command) {
363 
364 	/* These two are mostly handled at a higher layer */
365 	case SIOCSIFADDR:
366 		ifp->if_flags |= (IFF_UP | IFF_RUNNING);
367 		ifp->if_flags &= ~(IFF_OACTIVE);
368 		break;
369 	case SIOCGIFADDR:
370 		break;
371 
372 	/* Set flags */
373 	case SIOCSIFFLAGS:
374 		/*
375 		 * If the interface is marked up and stopped, then start it.
376 		 * If it is marked down and running, then stop it.
377 		 */
378 		if (ifr->ifr_flags & IFF_UP) {
379 			if (!(ifp->if_flags & IFF_RUNNING)) {
380 				ifp->if_flags &= ~(IFF_OACTIVE);
381 				ifp->if_flags |= IFF_RUNNING;
382 			}
383 		} else {
384 			if (ifp->if_flags & IFF_RUNNING)
385 				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
386 		}
387 		break;
388 
389 	/* Set the interface MTU */
390 	case SIOCSIFMTU:
391 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
392 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
393 			error = EINVAL;
394 		else
395 			ifp->if_mtu = ifr->ifr_mtu;
396 		break;
397 
398 	/* Stuff that's not supported */
399 	case SIOCADDMULTI:
400 	case SIOCDELMULTI:
401 		error = 0;
402 		break;
403 	case SIOCSIFPHYS:
404 		error = EOPNOTSUPP;
405 		break;
406 
407 	default:
408 		error = EINVAL;
409 		break;
410 	}
411 	(void) splx(s);
412 	return (error);
413 }
414 
415 /*
416  * This routine is called to deliver a packet out the interface.
417  * We simply look at the address family and relay the packet to
418  * the corresponding hook, if it exists and is connected.
419  */
420 
421 static int
422 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
423 		struct sockaddr *dst, struct rtentry *rt0)
424 {
425 	const priv_p priv = (priv_p) ifp->if_softc;
426 	const iffam_p iffam = get_iffam_from_af(dst->sa_family);
427 	meta_p meta = NULL;
428 	int len, error = 0;
429 
430 	/* Check interface flags */
431 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
432 		m_freem(m);
433 		return (ENETDOWN);
434 	}
435 
436 	/* BPF writes need to be handled specially */
437 	if (dst->sa_family == AF_UNSPEC) {
438 		if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
439 			return (ENOBUFS);
440 		dst->sa_family = (sa_family_t)*mtod(m, int32_t *);
441 		m->m_data += 4;
442 		m->m_len -= 4;
443 		m->m_pkthdr.len -= 4;
444 	}
445 
446 	/* Berkeley packet filter */
447 	ng_iface_bpftap(ifp, m, dst->sa_family);
448 
449 	/* Check address family to determine hook (if known) */
450 	if (iffam == NULL) {
451 		m_freem(m);
452 		log(LOG_WARNING, "%s: can't handle af%d\n",
453 		       ifp->if_xname, (int)dst->sa_family);
454 		return (EAFNOSUPPORT);
455 	}
456 
457 	/* Copy length before the mbuf gets invalidated */
458 	len = m->m_pkthdr.len;
459 
460 	/* Send packet; if hook is not connected, mbuf will get freed. */
461 	NG_SEND_DATA(error, *get_hook_from_iffam(priv, iffam), m, meta);
462 
463 	/* Update stats */
464 	if (error == 0) {
465 		ifp->if_obytes += len;
466 		ifp->if_opackets++;
467 	}
468 	return (error);
469 }
470 
471 /*
472  * This routine should never be called
473  */
474 
475 static void
476 ng_iface_start(struct ifnet *ifp)
477 {
478 	if_printf(ifp, "%s called?", __func__);
479 }
480 
481 /*
482  * Flash a packet by the BPF (requires prepending 4 byte AF header)
483  * Note the phoney mbuf; this is OK because BPF treats it read-only.
484  */
485 static void
486 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
487 {
488 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
489 	if (ifp->if_bpf != NULL) {
490 		int32_t family4 = (int32_t)family;
491 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
492 	}
493 }
494 
495 #ifdef DEBUG
496 /*
497  * Display an ioctl to the virtual interface
498  */
499 
500 static void
501 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
502 {
503 	char   *str;
504 
505 	switch (command & IOC_DIRMASK) {
506 	case IOC_VOID:
507 		str = "IO";
508 		break;
509 	case IOC_OUT:
510 		str = "IOR";
511 		break;
512 	case IOC_IN:
513 		str = "IOW";
514 		break;
515 	case IOC_INOUT:
516 		str = "IORW";
517 		break;
518 	default:
519 		str = "IO??";
520 	}
521 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
522 	       ifp->if_xname,
523 	       str,
524 	       IOCGROUP(command),
525 	       command & 0xff,
526 	       IOCPARM_LEN(command));
527 }
528 #endif /* DEBUG */
529 
530 /************************************************************************
531 			NETGRAPH NODE STUFF
532  ************************************************************************/
533 
534 /*
535  * Constructor for a node
536  */
537 static int
538 ng_iface_constructor(node_p node)
539 {
540 	char ifname[NG_IFACE_IFACE_NAME_MAX + 1];
541 	struct ifnet *ifp;
542 	priv_p priv;
543 	int error = 0;
544 
545 	/* Allocate node and interface private structures */
546 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_IFACE, M_NOWAIT|M_ZERO);
547 	if (priv == NULL)
548 		return (ENOMEM);
549 	MALLOC(ifp, struct ifnet *, sizeof(*ifp), M_NETGRAPH_IFACE, M_NOWAIT|M_ZERO);
550 	if (ifp == NULL) {
551 		FREE(priv, M_NETGRAPH_IFACE);
552 		return (ENOMEM);
553 	}
554 
555 	/* Link them together */
556 	ifp->if_softc = priv;
557 	priv->ifp = ifp;
558 
559 	/* Get an interface unit number */
560 	if ((error = ng_iface_get_unit(&priv->unit)) != 0) {
561 		FREE(ifp, M_NETGRAPH_IFACE);
562 		FREE(priv, M_NETGRAPH_IFACE);
563 		return (error);
564 	}
565 
566 	/* Link together node and private info */
567 	NG_NODE_SET_PRIVATE(node, priv);
568 	priv->node = node;
569 
570 	/* Initialize interface structure */
571 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
572 	ifp->if_output = ng_iface_output;
573 	ifp->if_start = ng_iface_start;
574 	ifp->if_ioctl = ng_iface_ioctl;
575 	ifp->if_watchdog = NULL;
576 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
577 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
578 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
579 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
580 	ifp->if_addrlen = 0;			/* XXX */
581 	ifp->if_hdrlen = 0;			/* XXX */
582 	ifp->if_baudrate = 64000;		/* XXX */
583 	TAILQ_INIT(&ifp->if_addrhead);
584 
585 	/* Give this node the same name as the interface (if possible) */
586 	bzero(ifname, sizeof(ifname));
587 	strlcpy(ifname, ifp->if_xname, sizeof(ifname));
588 	if (ng_name_node(node, ifname) != 0)
589 		log(LOG_WARNING, "%s: can't acquire netgraph name\n", ifname);
590 
591 	/* Attach the interface */
592 	if_attach(ifp);
593 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
594 
595 	/* Done */
596 	return (0);
597 }
598 
599 /*
600  * Give our ok for a hook to be added
601  */
602 static int
603 ng_iface_newhook(node_p node, hook_p hook, const char *name)
604 {
605 	const iffam_p iffam = get_iffam_from_name(name);
606 	hook_p *hookptr;
607 
608 	if (iffam == NULL)
609 		return (EPFNOSUPPORT);
610 	hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
611 	if (*hookptr != NULL)
612 		return (EISCONN);
613 	*hookptr = hook;
614 	return (0);
615 }
616 
617 /*
618  * Receive a control message
619  */
620 static int
621 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
622 {
623 	const priv_p priv = NG_NODE_PRIVATE(node);
624 	struct ifnet *const ifp = priv->ifp;
625 	struct ng_mesg *resp = NULL;
626 	int error = 0;
627 	struct ng_mesg *msg;
628 
629 	NGI_GET_MSG(item, msg);
630 	switch (msg->header.typecookie) {
631 	case NGM_IFACE_COOKIE:
632 		switch (msg->header.cmd) {
633 		case NGM_IFACE_GET_IFNAME:
634 		    {
635 			struct ng_iface_ifname *arg;
636 
637 			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
638 			if (resp == NULL) {
639 				error = ENOMEM;
640 				break;
641 			}
642 			arg = (struct ng_iface_ifname *)resp->data;
643 			strlcpy(arg->ngif_name, ifp->if_xname,
644 			    sizeof(arg->ngif_name));
645 			break;
646 		    }
647 
648 		case NGM_IFACE_POINT2POINT:
649 		case NGM_IFACE_BROADCAST:
650 		    {
651 
652 			/* Deny request if interface is UP */
653 			if ((ifp->if_flags & IFF_UP) != 0)
654 				return (EBUSY);
655 
656 			/* Change flags */
657 			switch (msg->header.cmd) {
658 			case NGM_IFACE_POINT2POINT:
659 				ifp->if_flags |= IFF_POINTOPOINT;
660 				ifp->if_flags &= ~IFF_BROADCAST;
661 				break;
662 			case NGM_IFACE_BROADCAST:
663 				ifp->if_flags &= ~IFF_POINTOPOINT;
664 				ifp->if_flags |= IFF_BROADCAST;
665 				break;
666 			}
667 			break;
668 		    }
669 
670 		default:
671 			error = EINVAL;
672 			break;
673 		}
674 		break;
675 	case NGM_CISCO_COOKIE:
676 		switch (msg->header.cmd) {
677 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
678 		    {
679 			struct ifaddr *ifa;
680 
681 			/* Return the first configured IP address */
682 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
683 				struct ng_cisco_ipaddr *ips;
684 
685 				if (ifa->ifa_addr->sa_family != AF_INET)
686 					continue;
687 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
688 				if (resp == NULL) {
689 					error = ENOMEM;
690 					break;
691 				}
692 				ips = (struct ng_cisco_ipaddr *)resp->data;
693 				ips->ipaddr = ((struct sockaddr_in *)
694 						ifa->ifa_addr)->sin_addr;
695 				ips->netmask = ((struct sockaddr_in *)
696 						ifa->ifa_netmask)->sin_addr;
697 				break;
698 			}
699 
700 			/* No IP addresses on this interface? */
701 			if (ifa == NULL)
702 				error = EADDRNOTAVAIL;
703 			break;
704 		    }
705 		default:
706 			error = EINVAL;
707 			break;
708 		}
709 		break;
710 	default:
711 		error = EINVAL;
712 		break;
713 	}
714 	NG_RESPOND_MSG(error, node, item, resp);
715 	NG_FREE_MSG(msg);
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, item_p item)
724 {
725 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
726 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
727 	struct ifnet *const ifp = priv->ifp;
728 	struct mbuf *m;
729 	int isr;
730 
731 	NGI_GET_M(item, m);
732 	NG_FREE_ITEM(item);
733 	/* Sanity checks */
734 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
735 	M_ASSERTPKTHDR(m);
736 	if (m == NULL)
737 		return (EINVAL);
738 	if ((ifp->if_flags & IFF_UP) == 0) {
739 		NG_FREE_M(m);
740 		return (ENETDOWN);
741 	}
742 
743 	/* Update interface stats */
744 	ifp->if_ipackets++;
745 	ifp->if_ibytes += m->m_pkthdr.len;
746 
747 	/* Note receiving interface */
748 	m->m_pkthdr.rcvif = ifp;
749 
750 	/* Berkeley packet filter */
751 	ng_iface_bpftap(ifp, m, iffam->family);
752 
753 	/* Send packet */
754 	switch (iffam->family) {
755 #ifdef INET
756 	case AF_INET:
757 		isr = NETISR_IP;
758 		break;
759 #endif
760 #ifdef INET6
761 	case AF_INET6:
762 		isr = NETISR_IPV6;
763 		break;
764 #endif
765 #ifdef IPX
766 	case AF_IPX:
767 		isr = NETISR_IPX;
768 		break;
769 #endif
770 #ifdef NETATALK
771 	case AF_APPLETALK:
772 		isr = NETISR_ATALK2;
773 		break;
774 #endif
775 	default:
776 		m_freem(m);
777 		return (EAFNOSUPPORT);
778 	}
779 	/* First chunk of an mbuf contains good junk */
780 	if (harvest.point_to_point)
781 		random_harvest(m, 16, 3, 0, RANDOM_NET);
782 	netisr_dispatch(isr, m);
783 	return (0);
784 }
785 
786 /*
787  * Shutdown and remove the node and its associated interface.
788  */
789 static int
790 ng_iface_shutdown(node_p node)
791 {
792 	const priv_p priv = NG_NODE_PRIVATE(node);
793 
794 	bpfdetach(priv->ifp);
795 	if_detach(priv->ifp);
796 	FREE(priv->ifp, M_NETGRAPH_IFACE);
797 	priv->ifp = NULL;
798 	ng_iface_free_unit(priv->unit);
799 	FREE(priv, M_NETGRAPH_IFACE);
800 	NG_NODE_SET_PRIVATE(node, NULL);
801 	NG_NODE_UNREF(node);
802 	return (0);
803 }
804 
805 /*
806  * Hook disconnection. Note that we do *not* shutdown when all
807  * hooks have been disconnected.
808  */
809 static int
810 ng_iface_disconnect(hook_p hook)
811 {
812 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
813 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
814 
815 	if (iffam == NULL)
816 		panic(__func__);
817 	*get_hook_from_iffam(priv, iffam) = NULL;
818 	return (0);
819 }
820 
821