xref: /freebsd/sys/netgraph/ng_iface.c (revision db612abe8df3355d1eb23bb3b50fdd97bc21e979)
1 /*
2  * ng_iface.c
3  */
4 
5 /*-
6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
7  * All rights reserved.
8  *
9  * Subject to the following obligations and disclaimer of warranty, use and
10  * redistribution of this software, in source or object code forms, with or
11  * without modifications are expressly permitted by Whistle Communications;
12  * provided, however, that:
13  * 1. Any and all reproductions of the source or object code must include the
14  *    copyright notice above and the following disclaimer of warranties; and
15  * 2. No rights are granted, in any manner or form, to use Whistle
16  *    Communications, Inc. trademarks, including the mark "WHISTLE
17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18  *    such appears in the above copyright notice or in the software.
19  *
20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36  * OF SUCH DAMAGE.
37  *
38  * Author: Archie Cobbs <archie@freebsd.org>
39  *
40  * $FreeBSD$
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/random.h>
68 #include <sys/sockio.h>
69 #include <sys/socket.h>
70 #include <sys/syslog.h>
71 #include <sys/libkern.h>
72 
73 #include <net/if.h>
74 #include <net/if_types.h>
75 #include <net/bpf.h>
76 #include <net/netisr.h>
77 
78 #include <netinet/in.h>
79 
80 #include <netgraph/ng_message.h>
81 #include <netgraph/netgraph.h>
82 #include <netgraph/ng_parse.h>
83 #include <netgraph/ng_iface.h>
84 #include <netgraph/ng_cisco.h>
85 
86 #ifdef NG_SEPARATE_MALLOC
87 MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node ");
88 #else
89 #define M_NETGRAPH_IFACE M_NETGRAPH
90 #endif
91 
92 /* This struct describes one address family */
93 struct iffam {
94 	sa_family_t	family;		/* Address family */
95 	const char	*hookname;	/* Name for hook */
96 };
97 typedef const struct iffam *iffam_p;
98 
99 /* List of address families supported by our interface */
100 const static struct iffam gFamilies[] = {
101 	{ AF_INET,	NG_IFACE_HOOK_INET	},
102 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
103 	{ AF_APPLETALK,	NG_IFACE_HOOK_ATALK	},
104 	{ AF_IPX,	NG_IFACE_HOOK_IPX	},
105 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
106 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
107 };
108 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
109 
110 /* Node private data */
111 struct ng_iface_private {
112 	struct	ifnet *ifp;		/* Our interface */
113 	int	unit;			/* Interface unit number */
114 	node_p	node;			/* Our netgraph node */
115 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
116 };
117 typedef struct ng_iface_private *priv_p;
118 
119 /* Interface methods */
120 static void	ng_iface_start(struct ifnet *ifp);
121 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
122 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
123 			struct sockaddr *dst, struct rtentry *rt0);
124 static void	ng_iface_bpftap(struct ifnet *ifp,
125 			struct mbuf *m, sa_family_t family);
126 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
127 			sa_family_t sa);
128 #ifdef DEBUG
129 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
130 #endif
131 
132 /* Netgraph methods */
133 static int		ng_iface_mod_event(module_t, int, void *);
134 static ng_constructor_t	ng_iface_constructor;
135 static ng_rcvmsg_t	ng_iface_rcvmsg;
136 static ng_shutdown_t	ng_iface_shutdown;
137 static ng_newhook_t	ng_iface_newhook;
138 static ng_rcvdata_t	ng_iface_rcvdata;
139 static ng_disconnect_t	ng_iface_disconnect;
140 
141 /* Helper stuff */
142 static iffam_p	get_iffam_from_af(sa_family_t family);
143 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
144 static iffam_p	get_iffam_from_name(const char *name);
145 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
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_parse_string_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 	{
186 	  NGM_IFACE_COOKIE,
187 	  NGM_IFACE_GET_IFINDEX,
188 	  "getifindex",
189 	  NULL,
190 	  &ng_parse_uint32_type
191 	},
192 	{ 0 }
193 };
194 
195 /* Node type descriptor */
196 static struct ng_type typestruct = {
197 	.version =	NG_ABI_VERSION,
198 	.name =		NG_IFACE_NODE_TYPE,
199 	.mod_event =	ng_iface_mod_event,
200 	.constructor =	ng_iface_constructor,
201 	.rcvmsg =	ng_iface_rcvmsg,
202 	.shutdown =	ng_iface_shutdown,
203 	.newhook =	ng_iface_newhook,
204 	.rcvdata =	ng_iface_rcvdata,
205 	.disconnect =	ng_iface_disconnect,
206 	.cmdlist =	ng_iface_cmds,
207 };
208 NETGRAPH_INIT(iface, &typestruct);
209 
210 static struct unrhdr	*ng_iface_unit;
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 			INTERFACE STUFF
276  ************************************************************************/
277 
278 /*
279  * Process an ioctl for the virtual interface
280  */
281 static int
282 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
283 {
284 	struct ifreq *const ifr = (struct ifreq *) data;
285 	int s, error = 0;
286 
287 #ifdef DEBUG
288 	ng_iface_print_ioctl(ifp, command, data);
289 #endif
290 	s = splimp();
291 	switch (command) {
292 
293 	/* These two are mostly handled at a higher layer */
294 	case SIOCSIFADDR:
295 		ifp->if_flags |= IFF_UP;
296 		ifp->if_drv_flags |= IFF_DRV_RUNNING;
297 		ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
298 		break;
299 	case SIOCGIFADDR:
300 		break;
301 
302 	/* Set flags */
303 	case SIOCSIFFLAGS:
304 		/*
305 		 * If the interface is marked up and stopped, then start it.
306 		 * If it is marked down and running, then stop it.
307 		 */
308 		if (ifr->ifr_flags & IFF_UP) {
309 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
310 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
311 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
312 			}
313 		} else {
314 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
315 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
316 				    IFF_DRV_OACTIVE);
317 		}
318 		break;
319 
320 	/* Set the interface MTU */
321 	case SIOCSIFMTU:
322 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
323 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
324 			error = EINVAL;
325 		else
326 			ifp->if_mtu = ifr->ifr_mtu;
327 		break;
328 
329 	/* Stuff that's not supported */
330 	case SIOCADDMULTI:
331 	case SIOCDELMULTI:
332 		error = 0;
333 		break;
334 	case SIOCSIFPHYS:
335 		error = EOPNOTSUPP;
336 		break;
337 
338 	default:
339 		error = EINVAL;
340 		break;
341 	}
342 	(void) splx(s);
343 	return (error);
344 }
345 
346 /*
347  * This routine is called to deliver a packet out the interface.
348  * We simply look at the address family and relay the packet to
349  * the corresponding hook, if it exists and is connected.
350  */
351 
352 static int
353 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
354 		struct sockaddr *dst, struct rtentry *rt0)
355 {
356 	uint32_t af;
357 	int error;
358 
359 	/* Check interface flags */
360 	if (!((ifp->if_flags & IFF_UP) &&
361 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
362 		m_freem(m);
363 		return (ENETDOWN);
364 	}
365 
366 	/* BPF writes need to be handled specially. */
367 	if (dst->sa_family == AF_UNSPEC) {
368 		bcopy(dst->sa_data, &af, sizeof(af));
369 		dst->sa_family = af;
370 	}
371 
372 	/* Berkeley packet filter */
373 	ng_iface_bpftap(ifp, m, dst->sa_family);
374 
375 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
376 		M_PREPEND(m, sizeof(sa_family_t), M_DONTWAIT);
377 		if (m == NULL) {
378 			IFQ_LOCK(&ifp->if_snd);
379 			IFQ_INC_DROPS(&ifp->if_snd);
380 			IFQ_UNLOCK(&ifp->if_snd);
381 			ifp->if_oerrors++;
382 			return (ENOBUFS);
383 		}
384 		*(sa_family_t *)m->m_data = dst->sa_family;
385 		IFQ_HANDOFF(ifp, m, error);
386 	} else
387 		error = ng_iface_send(ifp, m, dst->sa_family);
388 
389 	return (error);
390 }
391 
392 /*
393  * Start method is used only when ALTQ is enabled.
394  */
395 static void
396 ng_iface_start(struct ifnet *ifp)
397 {
398 	struct mbuf *m;
399 	sa_family_t sa;
400 
401 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
402 
403 	for(;;) {
404 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
405 		if (m == NULL)
406 			break;
407 		sa = *mtod(m, sa_family_t *);
408 		m_adj(m, sizeof(sa_family_t));
409 		ng_iface_send(ifp, m, sa);
410 	}
411 }
412 
413 /*
414  * Flash a packet by the BPF (requires prepending 4 byte AF header)
415  * Note the phoney mbuf; this is OK because BPF treats it read-only.
416  */
417 static void
418 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
419 {
420 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
421 	if (bpf_peers_present(ifp->if_bpf)) {
422 		int32_t family4 = (int32_t)family;
423 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
424 	}
425 }
426 
427 /*
428  * This routine does actual delivery of the packet into the
429  * netgraph(4). It is called from ng_iface_start() and
430  * ng_iface_output().
431  */
432 static int
433 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
434 {
435 	const priv_p priv = (priv_p) ifp->if_softc;
436 	const iffam_p iffam = get_iffam_from_af(sa);
437 	int error;
438 	int len;
439 
440 	/* Check address family to determine hook (if known) */
441 	if (iffam == NULL) {
442 		m_freem(m);
443 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
444 		return (EAFNOSUPPORT);
445 	}
446 
447 	/* Copy length before the mbuf gets invalidated. */
448 	len = m->m_pkthdr.len;
449 
450 	/* Send packet. If hook is not connected,
451 	   mbuf will get freed. */
452 	NG_SEND_DATA_ONLY(error, *get_hook_from_iffam(priv, iffam), m);
453 
454 	/* Update stats. */
455 	if (error == 0) {
456 		ifp->if_obytes += len;
457 		ifp->if_opackets++;
458 	}
459 
460 	return (error);
461 }
462 
463 #ifdef DEBUG
464 /*
465  * Display an ioctl to the virtual interface
466  */
467 
468 static void
469 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
470 {
471 	char   *str;
472 
473 	switch (command & IOC_DIRMASK) {
474 	case IOC_VOID:
475 		str = "IO";
476 		break;
477 	case IOC_OUT:
478 		str = "IOR";
479 		break;
480 	case IOC_IN:
481 		str = "IOW";
482 		break;
483 	case IOC_INOUT:
484 		str = "IORW";
485 		break;
486 	default:
487 		str = "IO??";
488 	}
489 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
490 	       ifp->if_xname,
491 	       str,
492 	       IOCGROUP(command),
493 	       command & 0xff,
494 	       IOCPARM_LEN(command));
495 }
496 #endif /* DEBUG */
497 
498 /************************************************************************
499 			NETGRAPH NODE STUFF
500  ************************************************************************/
501 
502 /*
503  * Constructor for a node
504  */
505 static int
506 ng_iface_constructor(node_p node)
507 {
508 	struct ifnet *ifp;
509 	priv_p priv;
510 
511 	/* Allocate node and interface private structures */
512 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_IFACE, M_NOWAIT|M_ZERO);
513 	if (priv == NULL)
514 		return (ENOMEM);
515 	ifp = if_alloc(IFT_PROPVIRTUAL);
516 	if (ifp == NULL) {
517 		FREE(priv, M_NETGRAPH_IFACE);
518 		return (ENOMEM);
519 	}
520 
521 	/* Link them together */
522 	ifp->if_softc = priv;
523 	priv->ifp = ifp;
524 
525 	/* Get an interface unit number */
526 	priv->unit = alloc_unr(ng_iface_unit);
527 
528 	/* Link together node and private info */
529 	NG_NODE_SET_PRIVATE(node, priv);
530 	priv->node = node;
531 
532 	/* Initialize interface structure */
533 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
534 	ifp->if_output = ng_iface_output;
535 	ifp->if_start = ng_iface_start;
536 	ifp->if_ioctl = ng_iface_ioctl;
537 	ifp->if_watchdog = NULL;
538 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
539 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
540 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
541 	ifp->if_addrlen = 0;			/* XXX */
542 	ifp->if_hdrlen = 0;			/* XXX */
543 	ifp->if_baudrate = 64000;		/* XXX */
544 	IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
545 	ifp->if_snd.ifq_drv_maxlen = IFQ_MAXLEN;
546 	IFQ_SET_READY(&ifp->if_snd);
547 
548 	/* Give this node the same name as the interface (if possible) */
549 	if (ng_name_node(node, ifp->if_xname) != 0)
550 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
551 		    ifp->if_xname);
552 
553 	/* Attach the interface */
554 	if_attach(ifp);
555 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
556 
557 	/* Done */
558 	return (0);
559 }
560 
561 /*
562  * Give our ok for a hook to be added
563  */
564 static int
565 ng_iface_newhook(node_p node, hook_p hook, const char *name)
566 {
567 	const iffam_p iffam = get_iffam_from_name(name);
568 	hook_p *hookptr;
569 
570 	if (iffam == NULL)
571 		return (EPFNOSUPPORT);
572 	hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
573 	if (*hookptr != NULL)
574 		return (EISCONN);
575 	*hookptr = hook;
576 	NG_HOOK_HI_STACK(hook);
577 	return (0);
578 }
579 
580 /*
581  * Receive a control message
582  */
583 static int
584 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
585 {
586 	const priv_p priv = NG_NODE_PRIVATE(node);
587 	struct ifnet *const ifp = priv->ifp;
588 	struct ng_mesg *resp = NULL;
589 	int error = 0;
590 	struct ng_mesg *msg;
591 
592 	NGI_GET_MSG(item, msg);
593 	switch (msg->header.typecookie) {
594 	case NGM_IFACE_COOKIE:
595 		switch (msg->header.cmd) {
596 		case NGM_IFACE_GET_IFNAME:
597 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
598 			if (resp == NULL) {
599 				error = ENOMEM;
600 				break;
601 			}
602 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
603 			break;
604 
605 		case NGM_IFACE_POINT2POINT:
606 		case NGM_IFACE_BROADCAST:
607 		    {
608 
609 			/* Deny request if interface is UP */
610 			if ((ifp->if_flags & IFF_UP) != 0)
611 				return (EBUSY);
612 
613 			/* Change flags */
614 			switch (msg->header.cmd) {
615 			case NGM_IFACE_POINT2POINT:
616 				ifp->if_flags |= IFF_POINTOPOINT;
617 				ifp->if_flags &= ~IFF_BROADCAST;
618 				break;
619 			case NGM_IFACE_BROADCAST:
620 				ifp->if_flags &= ~IFF_POINTOPOINT;
621 				ifp->if_flags |= IFF_BROADCAST;
622 				break;
623 			}
624 			break;
625 		    }
626 
627 		case NGM_IFACE_GET_IFINDEX:
628 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
629 			if (resp == NULL) {
630 				error = ENOMEM;
631 				break;
632 			}
633 			*((uint32_t *)resp->data) = priv->ifp->if_index;
634 			break;
635 
636 		default:
637 			error = EINVAL;
638 			break;
639 		}
640 		break;
641 	case NGM_CISCO_COOKIE:
642 		switch (msg->header.cmd) {
643 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
644 		    {
645 			struct ifaddr *ifa;
646 
647 			/* Return the first configured IP address */
648 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
649 				struct ng_cisco_ipaddr *ips;
650 
651 				if (ifa->ifa_addr->sa_family != AF_INET)
652 					continue;
653 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
654 				if (resp == NULL) {
655 					error = ENOMEM;
656 					break;
657 				}
658 				ips = (struct ng_cisco_ipaddr *)resp->data;
659 				ips->ipaddr = ((struct sockaddr_in *)
660 						ifa->ifa_addr)->sin_addr;
661 				ips->netmask = ((struct sockaddr_in *)
662 						ifa->ifa_netmask)->sin_addr;
663 				break;
664 			}
665 
666 			/* No IP addresses on this interface? */
667 			if (ifa == NULL)
668 				error = EADDRNOTAVAIL;
669 			break;
670 		    }
671 		default:
672 			error = EINVAL;
673 			break;
674 		}
675 		break;
676 	case NGM_FLOW_COOKIE:
677 		switch (msg->header.cmd) {
678 		case NGM_LINK_IS_UP:
679 			ifp->if_drv_flags |= IFF_DRV_RUNNING;
680 			break;
681 		case NGM_LINK_IS_DOWN:
682 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
683 			break;
684 		default:
685 			break;
686 		}
687 		break;
688 	default:
689 		error = EINVAL;
690 		break;
691 	}
692 	NG_RESPOND_MSG(error, node, item, resp);
693 	NG_FREE_MSG(msg);
694 	return (error);
695 }
696 
697 /*
698  * Recive data from a hook. Pass the packet to the correct input routine.
699  */
700 static int
701 ng_iface_rcvdata(hook_p hook, item_p item)
702 {
703 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
704 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
705 	struct ifnet *const ifp = priv->ifp;
706 	struct mbuf *m;
707 	int isr;
708 
709 	NGI_GET_M(item, m);
710 	NG_FREE_ITEM(item);
711 	/* Sanity checks */
712 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
713 	M_ASSERTPKTHDR(m);
714 	if ((ifp->if_flags & IFF_UP) == 0) {
715 		NG_FREE_M(m);
716 		return (ENETDOWN);
717 	}
718 
719 	/* Update interface stats */
720 	ifp->if_ipackets++;
721 	ifp->if_ibytes += m->m_pkthdr.len;
722 
723 	/* Note receiving interface */
724 	m->m_pkthdr.rcvif = ifp;
725 
726 	/* Berkeley packet filter */
727 	ng_iface_bpftap(ifp, m, iffam->family);
728 
729 	/* Send packet */
730 	switch (iffam->family) {
731 #ifdef INET
732 	case AF_INET:
733 		isr = NETISR_IP;
734 		break;
735 #endif
736 #ifdef INET6
737 	case AF_INET6:
738 		isr = NETISR_IPV6;
739 		break;
740 #endif
741 #ifdef IPX
742 	case AF_IPX:
743 		isr = NETISR_IPX;
744 		break;
745 #endif
746 #ifdef NETATALK
747 	case AF_APPLETALK:
748 		isr = NETISR_ATALK2;
749 		break;
750 #endif
751 	default:
752 		m_freem(m);
753 		return (EAFNOSUPPORT);
754 	}
755 	/* First chunk of an mbuf contains good junk */
756 	if (harvest.point_to_point)
757 		random_harvest(m, 16, 3, 0, RANDOM_NET);
758 	netisr_dispatch(isr, m);
759 	return (0);
760 }
761 
762 /*
763  * Shutdown and remove the node and its associated interface.
764  */
765 static int
766 ng_iface_shutdown(node_p node)
767 {
768 	const priv_p priv = NG_NODE_PRIVATE(node);
769 
770 	bpfdetach(priv->ifp);
771 	if_detach(priv->ifp);
772 	if_free(priv->ifp);
773 	priv->ifp = NULL;
774 	free_unr(ng_iface_unit, priv->unit);
775 	FREE(priv, M_NETGRAPH_IFACE);
776 	NG_NODE_SET_PRIVATE(node, NULL);
777 	NG_NODE_UNREF(node);
778 	return (0);
779 }
780 
781 /*
782  * Hook disconnection. Note that we do *not* shutdown when all
783  * hooks have been disconnected.
784  */
785 static int
786 ng_iface_disconnect(hook_p hook)
787 {
788 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
789 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
790 
791 	if (iffam == NULL)
792 		panic(__func__);
793 	*get_hook_from_iffam(priv, iffam) = NULL;
794 	return (0);
795 }
796 
797 /*
798  * Handle loading and unloading for this node type.
799  */
800 static int
801 ng_iface_mod_event(module_t mod, int event, void *data)
802 {
803 	int error = 0;
804 
805 	switch (event) {
806 	case MOD_LOAD:
807 		ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
808 		break;
809 	case MOD_UNLOAD:
810 		delete_unrhdr(ng_iface_unit);
811 		break;
812 	default:
813 		error = EOPNOTSUPP;
814 		break;
815 	}
816 	return (error);
817 }
818