xref: /freebsd/sys/netgraph/ng_iface.c (revision 4a5216a6dc0c3ce4cf5f2d3ee8af0c3ff3402c4f)
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 #include <sys/vimage.h>
73 
74 #include <net/if.h>
75 #include <net/if_types.h>
76 #include <net/bpf.h>
77 #include <net/netisr.h>
78 
79 #include <netinet/in.h>
80 
81 #include <netgraph/ng_message.h>
82 #include <netgraph/netgraph.h>
83 #include <netgraph/ng_parse.h>
84 #include <netgraph/ng_iface.h>
85 #include <netgraph/ng_cisco.h>
86 
87 #ifdef NG_SEPARATE_MALLOC
88 MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node ");
89 #else
90 #define M_NETGRAPH_IFACE M_NETGRAPH
91 #endif
92 
93 /* This struct describes one address family */
94 struct iffam {
95 	sa_family_t	family;		/* Address family */
96 	const char	*hookname;	/* Name for hook */
97 };
98 typedef const struct iffam *iffam_p;
99 
100 /* List of address families supported by our interface */
101 const static struct iffam gFamilies[] = {
102 	{ AF_INET,	NG_IFACE_HOOK_INET	},
103 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
104 	{ AF_APPLETALK,	NG_IFACE_HOOK_ATALK	},
105 	{ AF_IPX,	NG_IFACE_HOOK_IPX	},
106 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
107 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
108 };
109 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
110 
111 /* Node private data */
112 struct ng_iface_private {
113 	struct	ifnet *ifp;		/* Our interface */
114 	int	unit;			/* Interface unit number */
115 	node_p	node;			/* Our netgraph node */
116 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
117 };
118 typedef struct ng_iface_private *priv_p;
119 
120 /* Interface methods */
121 static void	ng_iface_start(struct ifnet *ifp);
122 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
123 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
124 			struct sockaddr *dst, struct rtentry *rt0);
125 static void	ng_iface_bpftap(struct ifnet *ifp,
126 			struct mbuf *m, sa_family_t family);
127 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
128 			sa_family_t sa);
129 #ifdef DEBUG
130 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
131 #endif
132 
133 /* Netgraph methods */
134 static int		ng_iface_mod_event(module_t, int, void *);
135 static ng_constructor_t	ng_iface_constructor;
136 static ng_rcvmsg_t	ng_iface_rcvmsg;
137 static ng_shutdown_t	ng_iface_shutdown;
138 static ng_newhook_t	ng_iface_newhook;
139 static ng_rcvdata_t	ng_iface_rcvdata;
140 static ng_disconnect_t	ng_iface_disconnect;
141 
142 /* Helper stuff */
143 static iffam_p	get_iffam_from_af(sa_family_t family);
144 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
145 static iffam_p	get_iffam_from_name(const char *name);
146 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
147 
148 /* Parse type for struct ng_cisco_ipaddr */
149 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
150 	= NG_CISCO_IPADDR_TYPE_INFO;
151 static const struct ng_parse_type ng_cisco_ipaddr_type = {
152 	&ng_parse_struct_type,
153 	&ng_cisco_ipaddr_type_fields
154 };
155 
156 /* List of commands and how to convert arguments to/from ASCII */
157 static const struct ng_cmdlist ng_iface_cmds[] = {
158 	{
159 	  NGM_IFACE_COOKIE,
160 	  NGM_IFACE_GET_IFNAME,
161 	  "getifname",
162 	  NULL,
163 	  &ng_parse_string_type
164 	},
165 	{
166 	  NGM_IFACE_COOKIE,
167 	  NGM_IFACE_POINT2POINT,
168 	  "point2point",
169 	  NULL,
170 	  NULL
171 	},
172 	{
173 	  NGM_IFACE_COOKIE,
174 	  NGM_IFACE_BROADCAST,
175 	  "broadcast",
176 	  NULL,
177 	  NULL
178 	},
179 	{
180 	  NGM_CISCO_COOKIE,
181 	  NGM_CISCO_GET_IPADDR,
182 	  "getipaddr",
183 	  NULL,
184 	  &ng_cisco_ipaddr_type
185 	},
186 	{
187 	  NGM_IFACE_COOKIE,
188 	  NGM_IFACE_GET_IFINDEX,
189 	  "getifindex",
190 	  NULL,
191 	  &ng_parse_uint32_type
192 	},
193 	{ 0 }
194 };
195 
196 /* Node type descriptor */
197 static struct ng_type typestruct = {
198 	.version =	NG_ABI_VERSION,
199 	.name =		NG_IFACE_NODE_TYPE,
200 	.mod_event =	ng_iface_mod_event,
201 	.constructor =	ng_iface_constructor,
202 	.rcvmsg =	ng_iface_rcvmsg,
203 	.shutdown =	ng_iface_shutdown,
204 	.newhook =	ng_iface_newhook,
205 	.rcvdata =	ng_iface_rcvdata,
206 	.disconnect =	ng_iface_disconnect,
207 	.cmdlist =	ng_iface_cmds,
208 };
209 NETGRAPH_INIT(iface, &typestruct);
210 
211 static struct unrhdr	*ng_iface_unit;
212 
213 /************************************************************************
214 			HELPER STUFF
215  ************************************************************************/
216 
217 /*
218  * Get the family descriptor from the family ID
219  */
220 static __inline iffam_p
221 get_iffam_from_af(sa_family_t family)
222 {
223 	iffam_p iffam;
224 	int k;
225 
226 	for (k = 0; k < NUM_FAMILIES; k++) {
227 		iffam = &gFamilies[k];
228 		if (iffam->family == family)
229 			return (iffam);
230 	}
231 	return (NULL);
232 }
233 
234 /*
235  * Get the family descriptor from the hook
236  */
237 static __inline iffam_p
238 get_iffam_from_hook(priv_p priv, hook_p hook)
239 {
240 	int k;
241 
242 	for (k = 0; k < NUM_FAMILIES; k++)
243 		if (priv->hooks[k] == hook)
244 			return (&gFamilies[k]);
245 	return (NULL);
246 }
247 
248 /*
249  * Get the hook from the iffam descriptor
250  */
251 
252 static __inline hook_p *
253 get_hook_from_iffam(priv_p priv, iffam_p iffam)
254 {
255 	return (&priv->hooks[iffam - gFamilies]);
256 }
257 
258 /*
259  * Get the iffam descriptor from the name
260  */
261 static __inline iffam_p
262 get_iffam_from_name(const char *name)
263 {
264 	iffam_p iffam;
265 	int k;
266 
267 	for (k = 0; k < NUM_FAMILIES; k++) {
268 		iffam = &gFamilies[k];
269 		if (!strcmp(iffam->hookname, name))
270 			return (iffam);
271 	}
272 	return (NULL);
273 }
274 
275 /************************************************************************
276 			INTERFACE STUFF
277  ************************************************************************/
278 
279 /*
280  * Process an ioctl for the virtual interface
281  */
282 static int
283 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
284 {
285 	struct ifreq *const ifr = (struct ifreq *) data;
286 	int s, error = 0;
287 
288 #ifdef DEBUG
289 	ng_iface_print_ioctl(ifp, command, data);
290 #endif
291 	s = splimp();
292 	switch (command) {
293 
294 	/* These two are mostly handled at a higher layer */
295 	case SIOCSIFADDR:
296 		ifp->if_flags |= IFF_UP;
297 		ifp->if_drv_flags |= IFF_DRV_RUNNING;
298 		ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
299 		break;
300 	case SIOCGIFADDR:
301 		break;
302 
303 	/* Set flags */
304 	case SIOCSIFFLAGS:
305 		/*
306 		 * If the interface is marked up and stopped, then start it.
307 		 * If it is marked down and running, then stop it.
308 		 */
309 		if (ifr->ifr_flags & IFF_UP) {
310 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
311 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
312 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
313 			}
314 		} else {
315 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
316 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
317 				    IFF_DRV_OACTIVE);
318 		}
319 		break;
320 
321 	/* Set the interface MTU */
322 	case SIOCSIFMTU:
323 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
324 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
325 			error = EINVAL;
326 		else
327 			ifp->if_mtu = ifr->ifr_mtu;
328 		break;
329 
330 	/* Stuff that's not supported */
331 	case SIOCADDMULTI:
332 	case SIOCDELMULTI:
333 		error = 0;
334 		break;
335 	case SIOCSIFPHYS:
336 		error = EOPNOTSUPP;
337 		break;
338 
339 	default:
340 		error = EINVAL;
341 		break;
342 	}
343 	(void) splx(s);
344 	return (error);
345 }
346 
347 /*
348  * This routine is called to deliver a packet out the interface.
349  * We simply look at the address family and relay the packet to
350  * the corresponding hook, if it exists and is connected.
351  */
352 
353 static int
354 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
355 		struct sockaddr *dst, struct rtentry *rt0)
356 {
357 	uint32_t af;
358 	int error;
359 
360 	/* Check interface flags */
361 	if (!((ifp->if_flags & IFF_UP) &&
362 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
363 		m_freem(m);
364 		return (ENETDOWN);
365 	}
366 
367 	/* BPF writes need to be handled specially. */
368 	if (dst->sa_family == AF_UNSPEC) {
369 		bcopy(dst->sa_data, &af, sizeof(af));
370 		dst->sa_family = af;
371 	}
372 
373 	/* Berkeley packet filter */
374 	ng_iface_bpftap(ifp, m, dst->sa_family);
375 
376 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
377 		M_PREPEND(m, sizeof(sa_family_t), M_DONTWAIT);
378 		if (m == NULL) {
379 			IFQ_LOCK(&ifp->if_snd);
380 			IFQ_INC_DROPS(&ifp->if_snd);
381 			IFQ_UNLOCK(&ifp->if_snd);
382 			ifp->if_oerrors++;
383 			return (ENOBUFS);
384 		}
385 		*(sa_family_t *)m->m_data = dst->sa_family;
386 		IFQ_HANDOFF(ifp, m, error);
387 	} else
388 		error = ng_iface_send(ifp, m, dst->sa_family);
389 
390 	return (error);
391 }
392 
393 /*
394  * Start method is used only when ALTQ is enabled.
395  */
396 static void
397 ng_iface_start(struct ifnet *ifp)
398 {
399 	struct mbuf *m;
400 	sa_family_t sa;
401 
402 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
403 
404 	for(;;) {
405 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
406 		if (m == NULL)
407 			break;
408 		sa = *mtod(m, sa_family_t *);
409 		m_adj(m, sizeof(sa_family_t));
410 		ng_iface_send(ifp, m, sa);
411 	}
412 }
413 
414 /*
415  * Flash a packet by the BPF (requires prepending 4 byte AF header)
416  * Note the phoney mbuf; this is OK because BPF treats it read-only.
417  */
418 static void
419 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
420 {
421 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
422 	if (bpf_peers_present(ifp->if_bpf)) {
423 		int32_t family4 = (int32_t)family;
424 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
425 	}
426 }
427 
428 /*
429  * This routine does actual delivery of the packet into the
430  * netgraph(4). It is called from ng_iface_start() and
431  * ng_iface_output().
432  */
433 static int
434 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
435 {
436 	const priv_p priv = (priv_p) ifp->if_softc;
437 	const iffam_p iffam = get_iffam_from_af(sa);
438 	int error;
439 	int len;
440 
441 	/* Check address family to determine hook (if known) */
442 	if (iffam == NULL) {
443 		m_freem(m);
444 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
445 		return (EAFNOSUPPORT);
446 	}
447 
448 	/* Copy length before the mbuf gets invalidated. */
449 	len = m->m_pkthdr.len;
450 
451 	/* Send packet. If hook is not connected,
452 	   mbuf will get freed. */
453 	NG_SEND_DATA_ONLY(error, *get_hook_from_iffam(priv, iffam), m);
454 
455 	/* Update stats. */
456 	if (error == 0) {
457 		ifp->if_obytes += len;
458 		ifp->if_opackets++;
459 	}
460 
461 	return (error);
462 }
463 
464 #ifdef DEBUG
465 /*
466  * Display an ioctl to the virtual interface
467  */
468 
469 static void
470 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
471 {
472 	char   *str;
473 
474 	switch (command & IOC_DIRMASK) {
475 	case IOC_VOID:
476 		str = "IO";
477 		break;
478 	case IOC_OUT:
479 		str = "IOR";
480 		break;
481 	case IOC_IN:
482 		str = "IOW";
483 		break;
484 	case IOC_INOUT:
485 		str = "IORW";
486 		break;
487 	default:
488 		str = "IO??";
489 	}
490 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
491 	       ifp->if_xname,
492 	       str,
493 	       IOCGROUP(command),
494 	       command & 0xff,
495 	       IOCPARM_LEN(command));
496 }
497 #endif /* DEBUG */
498 
499 /************************************************************************
500 			NETGRAPH NODE STUFF
501  ************************************************************************/
502 
503 /*
504  * Constructor for a node
505  */
506 static int
507 ng_iface_constructor(node_p node)
508 {
509 	INIT_VNET_NETGRAPH(curvnet);
510 	struct ifnet *ifp;
511 	priv_p priv;
512 
513 	/* Allocate node and interface private structures */
514 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_IFACE, M_NOWAIT|M_ZERO);
515 	if (priv == NULL)
516 		return (ENOMEM);
517 	ifp = if_alloc(IFT_PROPVIRTUAL);
518 	if (ifp == NULL) {
519 		FREE(priv, M_NETGRAPH_IFACE);
520 		return (ENOMEM);
521 	}
522 
523 	/* Link them together */
524 	ifp->if_softc = priv;
525 	priv->ifp = ifp;
526 
527 	/* Get an interface unit number */
528 	priv->unit = alloc_unr(V_ng_iface_unit);
529 
530 	/* Link together node and private info */
531 	NG_NODE_SET_PRIVATE(node, priv);
532 	priv->node = node;
533 
534 	/* Initialize interface structure */
535 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
536 	ifp->if_output = ng_iface_output;
537 	ifp->if_start = ng_iface_start;
538 	ifp->if_ioctl = ng_iface_ioctl;
539 	ifp->if_watchdog = NULL;
540 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
541 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
542 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
543 	ifp->if_addrlen = 0;			/* XXX */
544 	ifp->if_hdrlen = 0;			/* XXX */
545 	ifp->if_baudrate = 64000;		/* XXX */
546 	IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
547 	ifp->if_snd.ifq_drv_maxlen = IFQ_MAXLEN;
548 	IFQ_SET_READY(&ifp->if_snd);
549 
550 	/* Give this node the same name as the interface (if possible) */
551 	if (ng_name_node(node, ifp->if_xname) != 0)
552 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
553 		    ifp->if_xname);
554 
555 	/* Attach the interface */
556 	if_attach(ifp);
557 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
558 
559 	/* Done */
560 	return (0);
561 }
562 
563 /*
564  * Give our ok for a hook to be added
565  */
566 static int
567 ng_iface_newhook(node_p node, hook_p hook, const char *name)
568 {
569 	const iffam_p iffam = get_iffam_from_name(name);
570 	hook_p *hookptr;
571 
572 	if (iffam == NULL)
573 		return (EPFNOSUPPORT);
574 	hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
575 	if (*hookptr != NULL)
576 		return (EISCONN);
577 	*hookptr = hook;
578 	NG_HOOK_HI_STACK(hook);
579 	return (0);
580 }
581 
582 /*
583  * Receive a control message
584  */
585 static int
586 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
587 {
588 	const priv_p priv = NG_NODE_PRIVATE(node);
589 	struct ifnet *const ifp = priv->ifp;
590 	struct ng_mesg *resp = NULL;
591 	int error = 0;
592 	struct ng_mesg *msg;
593 
594 	NGI_GET_MSG(item, msg);
595 	switch (msg->header.typecookie) {
596 	case NGM_IFACE_COOKIE:
597 		switch (msg->header.cmd) {
598 		case NGM_IFACE_GET_IFNAME:
599 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
600 			if (resp == NULL) {
601 				error = ENOMEM;
602 				break;
603 			}
604 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
605 			break;
606 
607 		case NGM_IFACE_POINT2POINT:
608 		case NGM_IFACE_BROADCAST:
609 		    {
610 
611 			/* Deny request if interface is UP */
612 			if ((ifp->if_flags & IFF_UP) != 0)
613 				return (EBUSY);
614 
615 			/* Change flags */
616 			switch (msg->header.cmd) {
617 			case NGM_IFACE_POINT2POINT:
618 				ifp->if_flags |= IFF_POINTOPOINT;
619 				ifp->if_flags &= ~IFF_BROADCAST;
620 				break;
621 			case NGM_IFACE_BROADCAST:
622 				ifp->if_flags &= ~IFF_POINTOPOINT;
623 				ifp->if_flags |= IFF_BROADCAST;
624 				break;
625 			}
626 			break;
627 		    }
628 
629 		case NGM_IFACE_GET_IFINDEX:
630 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
631 			if (resp == NULL) {
632 				error = ENOMEM;
633 				break;
634 			}
635 			*((uint32_t *)resp->data) = priv->ifp->if_index;
636 			break;
637 
638 		default:
639 			error = EINVAL;
640 			break;
641 		}
642 		break;
643 	case NGM_CISCO_COOKIE:
644 		switch (msg->header.cmd) {
645 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
646 		    {
647 			struct ifaddr *ifa;
648 
649 			/* Return the first configured IP address */
650 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
651 				struct ng_cisco_ipaddr *ips;
652 
653 				if (ifa->ifa_addr->sa_family != AF_INET)
654 					continue;
655 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
656 				if (resp == NULL) {
657 					error = ENOMEM;
658 					break;
659 				}
660 				ips = (struct ng_cisco_ipaddr *)resp->data;
661 				ips->ipaddr = ((struct sockaddr_in *)
662 						ifa->ifa_addr)->sin_addr;
663 				ips->netmask = ((struct sockaddr_in *)
664 						ifa->ifa_netmask)->sin_addr;
665 				break;
666 			}
667 
668 			/* No IP addresses on this interface? */
669 			if (ifa == NULL)
670 				error = EADDRNOTAVAIL;
671 			break;
672 		    }
673 		default:
674 			error = EINVAL;
675 			break;
676 		}
677 		break;
678 	case NGM_FLOW_COOKIE:
679 		switch (msg->header.cmd) {
680 		case NGM_LINK_IS_UP:
681 			ifp->if_drv_flags |= IFF_DRV_RUNNING;
682 			break;
683 		case NGM_LINK_IS_DOWN:
684 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
685 			break;
686 		default:
687 			break;
688 		}
689 		break;
690 	default:
691 		error = EINVAL;
692 		break;
693 	}
694 	NG_RESPOND_MSG(error, node, item, resp);
695 	NG_FREE_MSG(msg);
696 	return (error);
697 }
698 
699 /*
700  * Recive data from a hook. Pass the packet to the correct input routine.
701  */
702 static int
703 ng_iface_rcvdata(hook_p hook, item_p item)
704 {
705 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
706 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
707 	struct ifnet *const ifp = priv->ifp;
708 	struct mbuf *m;
709 	int isr;
710 
711 	NGI_GET_M(item, m);
712 	NG_FREE_ITEM(item);
713 	/* Sanity checks */
714 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
715 	M_ASSERTPKTHDR(m);
716 	if ((ifp->if_flags & IFF_UP) == 0) {
717 		NG_FREE_M(m);
718 		return (ENETDOWN);
719 	}
720 
721 	/* Update interface stats */
722 	ifp->if_ipackets++;
723 	ifp->if_ibytes += m->m_pkthdr.len;
724 
725 	/* Note receiving interface */
726 	m->m_pkthdr.rcvif = ifp;
727 
728 	/* Berkeley packet filter */
729 	ng_iface_bpftap(ifp, m, iffam->family);
730 
731 	/* Send packet */
732 	switch (iffam->family) {
733 #ifdef INET
734 	case AF_INET:
735 		isr = NETISR_IP;
736 		break;
737 #endif
738 #ifdef INET6
739 	case AF_INET6:
740 		isr = NETISR_IPV6;
741 		break;
742 #endif
743 #ifdef IPX
744 	case AF_IPX:
745 		isr = NETISR_IPX;
746 		break;
747 #endif
748 #ifdef NETATALK
749 	case AF_APPLETALK:
750 		isr = NETISR_ATALK2;
751 		break;
752 #endif
753 	default:
754 		m_freem(m);
755 		return (EAFNOSUPPORT);
756 	}
757 	/* First chunk of an mbuf contains good junk */
758 	if (harvest.point_to_point)
759 		random_harvest(m, 16, 3, 0, RANDOM_NET);
760 	netisr_dispatch(isr, m);
761 	return (0);
762 }
763 
764 /*
765  * Shutdown and remove the node and its associated interface.
766  */
767 static int
768 ng_iface_shutdown(node_p node)
769 {
770 	INIT_VNET_NETGRAPH(curvnet);
771 	const priv_p priv = NG_NODE_PRIVATE(node);
772 
773 	/*
774 	 * The ifnet may be in a different vnet than the netgraph node,
775 	 * hence we have to change the current vnet context here.
776 	 */
777 	CURVNET_SET_QUIET(priv->ifp->if_vnet);
778 	bpfdetach(priv->ifp);
779 	if_detach(priv->ifp);
780 	if_free(priv->ifp);
781 	CURVNET_RESTORE();
782 	priv->ifp = NULL;
783 	free_unr(V_ng_iface_unit, priv->unit);
784 	FREE(priv, M_NETGRAPH_IFACE);
785 	NG_NODE_SET_PRIVATE(node, NULL);
786 	NG_NODE_UNREF(node);
787 	return (0);
788 }
789 
790 /*
791  * Hook disconnection. Note that we do *not* shutdown when all
792  * hooks have been disconnected.
793  */
794 static int
795 ng_iface_disconnect(hook_p hook)
796 {
797 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
798 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
799 
800 	if (iffam == NULL)
801 		panic(__func__);
802 	*get_hook_from_iffam(priv, iffam) = NULL;
803 	return (0);
804 }
805 
806 /*
807  * Handle loading and unloading for this node type.
808  */
809 static int
810 ng_iface_mod_event(module_t mod, int event, void *data)
811 {
812 	int error = 0;
813 
814 	switch (event) {
815 	case MOD_LOAD:
816 		V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
817 		break;
818 	case MOD_UNLOAD:
819 		delete_unrhdr(V_ng_iface_unit);
820 		break;
821 	default:
822 		error = EOPNOTSUPP;
823 		break;
824 	}
825 	return (error);
826 }
827