xref: /freebsd/sys/netgraph/ng_iface.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
1 
2 /*
3  * ng_iface.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Archie Cobbs <archie@whistle.com>
38  *
39  * $FreeBSD$
40  * $Whistle: ng_iface.c,v 1.33 1999/11/01 09:24:51 julian Exp $
41  */
42 
43 /*
44  * This node is also a system networking interface. It has
45  * a hook for each protocol (IP, AppleTalk, IPX, etc). Packets
46  * are simply relayed between the interface and the hooks.
47  *
48  * Interfaces are named ng0, ng1, .... FreeBSD does not support
49  * the removal of interfaces, so iface nodes are persistent.
50  *
51  * This node also includes Berkeley packet filter support.
52  */
53 
54 #include "opt_inet.h"
55 #include "opt_atalk.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/sockio.h>
66 #include <sys/socket.h>
67 #include <sys/syslog.h>
68 
69 #include <net/if.h>
70 #include <net/if_types.h>
71 #include <net/netisr.h>
72 
73 #include <netinet/in.h>
74 
75 #include <netgraph/ng_message.h>
76 #include <netgraph/netgraph.h>
77 #include <netgraph/ng_iface.h>
78 #include <netgraph/ng_cisco.h>
79 
80 #ifdef INET
81 #include <netinet/in_systm.h>
82 #include <netinet/in_var.h>
83 #include <netinet/in_var.h>
84 #endif
85 
86 #ifdef NETATALK
87 #include <netatalk/at.h>
88 #include <netatalk/at_var.h>
89 #endif
90 
91 #ifdef IPX
92 #include <netipx/ipx.h>
93 #include <netipx/ipx_if.h>
94 #endif
95 
96 #ifdef NS
97 #include <netns/ns.h>
98 #include <netns/ns_if.h>
99 #endif
100 
101 #include <net/bpf.h>
102 
103 /* This struct describes one address family */
104 struct iffam {
105 	char   *hookname;	/* Name for hook */
106 	u_char  af;		/* Family number */
107 	u_char  netisr;		/* or NETISR_NONE */
108 	union {
109 		void	*_dummy;			/* avoid warning */
110 		struct	ifqueue *inq;			/* if netisr */
111 		void	(*input)(struct mbuf *m);	/* if direct input */
112 	}       u;
113 };
114 typedef const struct iffam *iffam_p;
115 
116 #define NETISR_NONE	0xff
117 
118 /* List of address families supported by our interface. Each address
119    family has a way to input packets to it, either by calling a function
120    directly (such as ip_input()) or by adding the packet to a queue and
121    setting a NETISR bit. */
122 const static struct iffam gFamilies[] = {
123 #ifdef INET
124 	{
125 		NG_IFACE_HOOK_INET,
126 		AF_INET,
127 		NETISR_NONE,
128 		{ ip_input }
129 	},
130 #endif
131 #ifdef NETATALK
132 	{
133 		NG_IFACE_HOOK_ATALK,
134 		AF_APPLETALK,
135 		NETISR_ATALK,
136 		{ &atintrq2 }
137 	},
138 #endif
139 #ifdef IPX
140 	{
141 		NG_IFACE_HOOK_IPX,
142 		AF_IPX,
143 		NETISR_IPX,
144 		{ &ipxintrq }
145 	},
146 #endif
147 #ifdef NS
148 	{
149 		NG_IFACE_HOOK_NS,
150 		AF_NS,
151 		NETISR_NS,
152 		{ &nsintrq }
153 	},
154 #endif
155 };
156 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
157 
158 /* Node private data */
159 struct ng_iface_private {
160 	struct	ifnet *ifp;		/* This interface */
161 	node_p	node;			/* Our netgraph node */
162 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
163 	struct	private *next;		/* When hung on the free list */
164 };
165 typedef struct ng_iface_private *priv_p;
166 
167 /* Interface methods */
168 static void	ng_iface_start(struct ifnet *ifp);
169 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
170 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
171 		struct sockaddr *dst, struct rtentry *rt0);
172 static void	ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, u_int af);
173 #ifdef DEBUG
174 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
175 #endif
176 
177 /* Netgraph methods */
178 static ng_constructor_t	ng_iface_constructor;
179 static ng_rcvmsg_t	ng_iface_rcvmsg;
180 static ng_shutdown_t	ng_iface_rmnode;
181 static ng_newhook_t	ng_iface_newhook;
182 static ng_rcvdata_t	ng_iface_rcvdata;
183 static ng_disconnect_t	ng_iface_disconnect;
184 
185 /* Helper stuff */
186 static iffam_p	get_iffam_from_af(int af);
187 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
188 static iffam_p	get_iffam_from_name(const char *name);
189 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
190 
191 /* Node type descriptor */
192 static struct ng_type typestruct = {
193 	NG_VERSION,
194 	NG_IFACE_NODE_TYPE,
195 	NULL,
196 	ng_iface_constructor,
197 	ng_iface_rcvmsg,
198 	ng_iface_rmnode,
199 	ng_iface_newhook,
200 	NULL,
201 	NULL,
202 	ng_iface_rcvdata,
203 	ng_iface_rcvdata,
204 	ng_iface_disconnect,
205 	NULL
206 };
207 NETGRAPH_INIT(iface, &typestruct);
208 
209 static char ng_iface_ifname[] = NG_IFACE_IFACE_NAME;
210 static int ng_iface_next_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(int af)
221 {
222 	iffam_p iffam;
223 	int k;
224 
225 	for (k = 0; k < NUM_FAMILIES; k++) {
226 		iffam = &gFamilies[k];
227 		if (iffam->af == af)
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 | IFF_RUNNING);
296 		ifp->if_flags &= ~(IFF_OACTIVE);
297 		break;
298 	case SIOCGIFADDR:
299 		break;
300 
301 	/* Set flags */
302 	case SIOCSIFFLAGS:
303 		/*
304 		 * If the interface is marked up and stopped, then start it.
305 		 * If it is marked down and running, then stop it.
306 		 */
307 		if (ifr->ifr_flags & IFF_UP) {
308 			if (!(ifp->if_flags & IFF_RUNNING)) {
309 				ifp->if_flags &= ~(IFF_OACTIVE);
310 				ifp->if_flags |= IFF_RUNNING;
311 			}
312 		} else {
313 			if (ifp->if_flags & IFF_RUNNING)
314 				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
315 		}
316 		break;
317 
318 	/* Set the interface MTU */
319 	case SIOCSIFMTU:
320 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
321 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
322 			error = EINVAL;
323 		else
324 			ifp->if_mtu = ifr->ifr_mtu;
325 		break;
326 
327 	/* Stuff that's not supported */
328 	case SIOCADDMULTI:
329 	case SIOCDELMULTI:
330 		error = 0;
331 		break;
332 	case SIOCSIFPHYS:
333 		error = EOPNOTSUPP;
334 		break;
335 
336 	default:
337 		error = EINVAL;
338 		break;
339 	}
340 	(void) splx(s);
341 	return (error);
342 }
343 
344 /*
345  * This routine is called to deliver a packet out the interface.
346  * We simply look at the address family and relay the packet to
347  * the corresponding hook, if it exists and is connected.
348  */
349 
350 static int
351 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
352 		struct sockaddr *dst, struct rtentry *rt0)
353 {
354 	const priv_p priv = (priv_p) ifp->if_softc;
355 	const iffam_p iffam = get_iffam_from_af(dst->sa_family);
356 	meta_p meta = NULL;
357 	int len, error = 0;
358 
359 	/* Check interface flags */
360 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
361 		m_freem(m);
362 		return (ENETDOWN);
363 	}
364 
365 	/* Berkeley packet filter */
366 	ng_iface_bpftap(ifp, m, dst->sa_family);
367 
368 	/* Check address family to determine hook (if known) */
369 	if (iffam == NULL) {
370 		m_freem(m);
371 		log(LOG_WARNING, "%s%d: can't handle af%d\n",
372 		       ifp->if_name, ifp->if_unit, dst->sa_family);
373 		return (EAFNOSUPPORT);
374 	}
375 
376 	/* Copy length before the mbuf gets invalidated */
377 	len = m->m_pkthdr.len;
378 
379 	/* Send packet; if hook is not connected, mbuf will get freed. */
380 	NG_SEND_DATA(error, *get_hook_from_iffam(priv, iffam), m, meta);
381 
382 	/* Update stats */
383 	if (error == 0) {
384 		ifp->if_obytes += len;
385 		ifp->if_opackets++;
386 	}
387 	return (error);
388 }
389 
390 /*
391  * This routine should never be called
392  */
393 
394 static void
395 ng_iface_start(struct ifnet *ifp)
396 {
397 	printf("%s%d: %s called?", ifp->if_name, ifp->if_unit, __FUNCTION__);
398 }
399 
400 /*
401  * Flash a packet by the BPF (requires prepending 4 byte AF header)
402  * Note the phoney mbuf; this is OK because BPF treats it read-only.
403  */
404 static void
405 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, u_int af)
406 {
407 	struct mbuf m2;
408 
409 	if (ifp->if_bpf) {
410 		if (af == AF_UNSPEC) {
411 			af = *(mtod(m, int *));
412 			m->m_len -= sizeof(int);
413 			m->m_pkthdr.len -= sizeof(int);
414 			m->m_data += sizeof(int);
415 		}
416 		if (!ifp->if_bpf)
417 			return;
418 		m2.m_next = m;
419 		m2.m_len = 4;
420 		m2.m_data = (char *) &af;
421 		bpf_mtap(ifp, &m2);
422 	}
423 }
424 
425 #ifdef DEBUG
426 /*
427  * Display an ioctl to the virtual interface
428  */
429 
430 static void
431 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
432 {
433 	char   *str;
434 
435 	switch (command & IOC_DIRMASK) {
436 	case IOC_VOID:
437 		str = "IO";
438 		break;
439 	case IOC_OUT:
440 		str = "IOR";
441 		break;
442 	case IOC_IN:
443 		str = "IOW";
444 		break;
445 	case IOC_INOUT:
446 		str = "IORW";
447 		break;
448 	default:
449 		str = "IO??";
450 	}
451 	log(LOG_DEBUG, "%s%d: %s('%c', %d, char[%d])\n",
452 	       ifp->if_name, ifp->if_unit,
453 	       str,
454 	       IOCGROUP(command),
455 	       command & 0xff,
456 	       IOCPARM_LEN(command));
457 }
458 #endif /* DEBUG */
459 
460 /************************************************************************
461 			NETGRAPH NODE STUFF
462  ************************************************************************/
463 
464 /*
465  * Constructor for a node
466  */
467 static int
468 ng_iface_constructor(node_p *nodep)
469 {
470 	char ifname[NG_IFACE_IFACE_NAME_MAX + 1];
471 	struct ifnet *ifp;
472 	node_p node;
473 	priv_p priv;
474 	int error = 0;
475 
476 	/* Allocate node and interface private structures */
477 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
478 	if (priv == NULL)
479 		return (ENOMEM);
480 	bzero(priv, sizeof(*priv));
481 	MALLOC(ifp, struct ifnet *, sizeof(*ifp), M_NETGRAPH, M_WAITOK);
482 	if (ifp == NULL) {
483 		FREE(priv, M_NETGRAPH);
484 		return (ENOMEM);
485 	}
486 	bzero(ifp, sizeof(*ifp));
487 
488 	/* Link them together */
489 	ifp->if_softc = priv;
490 	priv->ifp = ifp;
491 
492 	/* Call generic node constructor */
493 	if ((error = ng_make_node_common(&typestruct, nodep))) {
494 		FREE(priv, M_NETGRAPH);
495 		FREE(ifp, M_NETGRAPH);
496 		return (error);
497 	}
498 	node = *nodep;
499 
500 	/* Link together node and private info */
501 	node->private = priv;
502 	priv->node = node;
503 
504 	/* Initialize interface structure */
505 	ifp->if_name = ng_iface_ifname;
506 	ifp->if_unit = ng_iface_next_unit++;
507 	ifp->if_output = ng_iface_output;
508 	ifp->if_start = ng_iface_start;
509 	ifp->if_ioctl = ng_iface_ioctl;
510 	ifp->if_watchdog = NULL;
511 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
512 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
513 	ifp->if_flags = (IFF_SIMPLEX | IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST);
514 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
515 	ifp->if_addrlen = 0;			/* XXX */
516 	ifp->if_hdrlen = 0;			/* XXX */
517 	ifp->if_baudrate = 64000;		/* XXX */
518 	TAILQ_INIT(&ifp->if_addrhead);
519 
520 	/* Give this node the same name as the interface (if possible) */
521 	bzero(ifname, sizeof(ifname));
522 	sprintf(ifname, "%s%d", ifp->if_name, ifp->if_unit);
523 	(void) ng_name_node(node, ifname);
524 
525 	/* Attach the interface */
526 	if_attach(ifp);
527 	bpfattach(ifp, DLT_NULL, sizeof(u_int));
528 
529 	/* Done */
530 	return (0);
531 }
532 
533 /*
534  * Give our ok for a hook to be added
535  */
536 static int
537 ng_iface_newhook(node_p node, hook_p hook, const char *name)
538 {
539 	const iffam_p iffam = get_iffam_from_name(name);
540 	hook_p *hookptr;
541 
542 	if (iffam == NULL)
543 		return (EPFNOSUPPORT);
544 	hookptr = get_hook_from_iffam((priv_p) node->private, iffam);
545 	if (*hookptr != NULL)
546 		return (EISCONN);
547 	*hookptr = hook;
548 	return (0);
549 }
550 
551 /*
552  * Receive a control message
553  */
554 static int
555 ng_iface_rcvmsg(node_p node, struct ng_mesg *msg,
556 		const char *retaddr, struct ng_mesg **rptr)
557 {
558 	const priv_p priv = node->private;
559 	struct ifnet *const ifp = priv->ifp;
560 	struct ng_mesg *resp = NULL;
561 	int error = 0;
562 
563 	switch (msg->header.typecookie) {
564 	case NGM_IFACE_COOKIE:
565 		switch (msg->header.cmd) {
566 		case NGM_IFACE_GET_IFNAME:
567 		    {
568 			struct ng_iface_ifname *arg;
569 
570 			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
571 			if (resp == NULL) {
572 				error = ENOMEM;
573 				break;
574 			}
575 			arg = (struct ng_iface_ifname *) resp->data;
576 			sprintf(arg->ngif_name,
577 			    "%s%d", ifp->if_name, ifp->if_unit);
578 			break;
579 		    }
580 
581 		case NGM_IFACE_GET_IFADDRS:
582 		    {
583 			struct ifaddr *ifa;
584 			caddr_t ptr;
585 			int buflen;
586 
587 #define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
588 
589 			/* Determine size of response and allocate it */
590 			buflen = 0;
591 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
592 				buflen += SA_SIZE(ifa->ifa_addr);
593 			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
594 			if (resp == NULL) {
595 				error = ENOMEM;
596 				break;
597 			}
598 
599 			/* Add addresses */
600 			ptr = resp->data;
601 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
602 				const int len = SA_SIZE(ifa->ifa_addr);
603 
604 				if (buflen < len) {
605 					log(LOG_ERR, "%s%d: len changed?\n",
606 					    ifp->if_name, ifp->if_unit);
607 					break;
608 				}
609 				bcopy(ifa->ifa_addr, ptr, len);
610 				ptr += len;
611 				buflen -= len;
612 			}
613 			break;
614 #undef SA_SIZE
615 		    }
616 
617 		default:
618 			error = EINVAL;
619 			break;
620 		}
621 		break;
622 	case NGM_CISCO_COOKIE:
623 		switch (msg->header.cmd) {
624 		case NGM_CISCO_GET_IPADDR:	/* we understand this too */
625 		    {
626 			struct ifaddr *ifa;
627 
628 			/* Return the first configured IP address */
629 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
630 				struct in_addr *ips;
631 
632 				if (ifa->ifa_addr->sa_family != AF_INET)
633 					continue;
634 				NG_MKRESPONSE(resp, msg,
635 				    2 * sizeof(*ips), M_NOWAIT);
636 				if (resp == NULL) {
637 					error = ENOMEM;
638 					break;
639 				}
640 				ips = (struct in_addr *) resp->data;
641 				ips[0] = ((struct sockaddr_in *)
642 						ifa->ifa_addr)->sin_addr;
643 				ips[1] = ((struct sockaddr_in *)
644 						ifa->ifa_netmask)->sin_addr;
645 				break;
646 			}
647 
648 			/* No IP addresses on this interface? */
649 			if (ifa == NULL)
650 				error = EADDRNOTAVAIL;
651 			break;
652 		    }
653 		default:
654 			error = EINVAL;
655 			break;
656 		}
657 		break;
658 	default:
659 		error = EINVAL;
660 		break;
661 	}
662 	if (rptr)
663 		*rptr = resp;
664 	else if (resp)
665 		FREE(resp, M_NETGRAPH);
666 	FREE(msg, M_NETGRAPH);
667 	return (error);
668 }
669 
670 /*
671  * Recive data from a hook. Pass the packet to the correct input routine.
672  */
673 static int
674 ng_iface_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
675 {
676 	const priv_p priv = hook->node->private;
677 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
678 	struct ifnet *const ifp = priv->ifp;
679 	int s, error = 0;
680 
681 	/* Sanity checks */
682 	KASSERT(iffam != NULL, ("%s: iffam", __FUNCTION__));
683 	KASSERT(m->m_flags & M_PKTHDR, ("%s: not pkthdr", __FUNCTION__));
684 	if (m == NULL)
685 		return (EINVAL);
686 	if ((ifp->if_flags & IFF_UP) == 0) {
687 		NG_FREE_DATA(m, meta);
688 		return (ENETDOWN);
689 	}
690 
691 	/* Update interface stats */
692 	ifp->if_ipackets++;
693 	ifp->if_ibytes += m->m_pkthdr.len;
694 
695 	/* Note receiving interface */
696 	m->m_pkthdr.rcvif = ifp;
697 
698 	/* Berkeley packet filter */
699 	ng_iface_bpftap(ifp, m, iffam->af);
700 
701 	/* Ignore any meta-data */
702 	NG_FREE_META(meta);
703 
704 	/* Send packet, either by NETISR or use a direct input function */
705 	switch (iffam->netisr) {
706 	case NETISR_NONE:
707 		(*iffam->u.input)(m);
708 		break;
709 	default:
710 		s = splimp();
711 		schednetisr(iffam->netisr);
712 		if (IF_QFULL(iffam->u.inq)) {
713 			IF_DROP(iffam->u.inq);
714 			m_freem(m);
715 			error = ENOBUFS;
716 		} else
717 			IF_ENQUEUE(iffam->u.inq, m);
718 		splx(s);
719 		break;
720 	}
721 
722 	/* Done */
723 	return (error);
724 }
725 
726 /*
727  * Because the BSD networking code doesn't support the removal of
728  * networking interfaces, iface nodes (once created) are persistent.
729  * So this method breaks all connections and marks the interface
730  * down, but does not remove the node.
731  */
732 static int
733 ng_iface_rmnode(node_p node)
734 {
735 	const priv_p priv = node->private;
736 	struct ifnet *const ifp = priv->ifp;
737 
738 	ng_cutlinks(node);
739 	node->flags &= ~NG_INVALID;
740 	ifp->if_flags &= ~(IFF_UP | IFF_RUNNING | IFF_OACTIVE);
741 	return (0);
742 }
743 
744 /*
745  * Hook disconnection
746  */
747 static int
748 ng_iface_disconnect(hook_p hook)
749 {
750 	const priv_p priv = hook->node->private;
751 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
752 
753 	if (iffam == NULL)
754 		panic(__FUNCTION__);
755 	*get_hook_from_iffam(priv, iffam) = NULL;
756 	return (0);
757 }
758 
759