xref: /freebsd/sys/netgraph/ng_iface.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
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 #include <net/route.h>
79 
80 #include <netinet/in.h>
81 
82 #include <netgraph/ng_message.h>
83 #include <netgraph/netgraph.h>
84 #include <netgraph/ng_parse.h>
85 #include <netgraph/ng_iface.h>
86 #include <netgraph/ng_cisco.h>
87 
88 #ifdef NG_SEPARATE_MALLOC
89 MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node ");
90 #else
91 #define M_NETGRAPH_IFACE M_NETGRAPH
92 #endif
93 
94 /* This struct describes one address family */
95 struct iffam {
96 	sa_family_t	family;		/* Address family */
97 	const char	*hookname;	/* Name for hook */
98 };
99 typedef const struct iffam *iffam_p;
100 
101 /* List of address families supported by our interface */
102 const static struct iffam gFamilies[] = {
103 	{ AF_INET,	NG_IFACE_HOOK_INET	},
104 	{ AF_INET6,	NG_IFACE_HOOK_INET6	},
105 	{ AF_APPLETALK,	NG_IFACE_HOOK_ATALK	},
106 	{ AF_IPX,	NG_IFACE_HOOK_IPX	},
107 	{ AF_ATM,	NG_IFACE_HOOK_ATM	},
108 	{ AF_NATM,	NG_IFACE_HOOK_NATM	},
109 };
110 #define NUM_FAMILIES		(sizeof(gFamilies) / sizeof(*gFamilies))
111 
112 /* Node private data */
113 struct ng_iface_private {
114 	struct	ifnet *ifp;		/* Our interface */
115 	int	unit;			/* Interface unit number */
116 	node_p	node;			/* Our netgraph node */
117 	hook_p	hooks[NUM_FAMILIES];	/* Hook for each address family */
118 };
119 typedef struct ng_iface_private *priv_p;
120 
121 /* Interface methods */
122 static void	ng_iface_start(struct ifnet *ifp);
123 static int	ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
124 static int	ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
125     			struct sockaddr *dst, struct route *ro);
126 static void	ng_iface_bpftap(struct ifnet *ifp,
127 			struct mbuf *m, sa_family_t family);
128 static int	ng_iface_send(struct ifnet *ifp, struct mbuf *m,
129 			sa_family_t sa);
130 #ifdef DEBUG
131 static void	ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
132 #endif
133 
134 /* Netgraph methods */
135 static int		ng_iface_mod_event(module_t, int, void *);
136 static ng_constructor_t	ng_iface_constructor;
137 static ng_rcvmsg_t	ng_iface_rcvmsg;
138 static ng_shutdown_t	ng_iface_shutdown;
139 static ng_newhook_t	ng_iface_newhook;
140 static ng_rcvdata_t	ng_iface_rcvdata;
141 static ng_disconnect_t	ng_iface_disconnect;
142 
143 /* Helper stuff */
144 static iffam_p	get_iffam_from_af(sa_family_t family);
145 static iffam_p	get_iffam_from_hook(priv_p priv, hook_p hook);
146 static iffam_p	get_iffam_from_name(const char *name);
147 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
148 
149 /* Parse type for struct ng_cisco_ipaddr */
150 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
151 	= NG_CISCO_IPADDR_TYPE_INFO;
152 static const struct ng_parse_type ng_cisco_ipaddr_type = {
153 	&ng_parse_struct_type,
154 	&ng_cisco_ipaddr_type_fields
155 };
156 
157 /* List of commands and how to convert arguments to/from ASCII */
158 static const struct ng_cmdlist ng_iface_cmds[] = {
159 	{
160 	  NGM_IFACE_COOKIE,
161 	  NGM_IFACE_GET_IFNAME,
162 	  "getifname",
163 	  NULL,
164 	  &ng_parse_string_type
165 	},
166 	{
167 	  NGM_IFACE_COOKIE,
168 	  NGM_IFACE_POINT2POINT,
169 	  "point2point",
170 	  NULL,
171 	  NULL
172 	},
173 	{
174 	  NGM_IFACE_COOKIE,
175 	  NGM_IFACE_BROADCAST,
176 	  "broadcast",
177 	  NULL,
178 	  NULL
179 	},
180 	{
181 	  NGM_CISCO_COOKIE,
182 	  NGM_CISCO_GET_IPADDR,
183 	  "getipaddr",
184 	  NULL,
185 	  &ng_cisco_ipaddr_type
186 	},
187 	{
188 	  NGM_IFACE_COOKIE,
189 	  NGM_IFACE_GET_IFINDEX,
190 	  "getifindex",
191 	  NULL,
192 	  &ng_parse_uint32_type
193 	},
194 	{ 0 }
195 };
196 
197 /* Node type descriptor */
198 static struct ng_type typestruct = {
199 	.version =	NG_ABI_VERSION,
200 	.name =		NG_IFACE_NODE_TYPE,
201 	.mod_event =	ng_iface_mod_event,
202 	.constructor =	ng_iface_constructor,
203 	.rcvmsg =	ng_iface_rcvmsg,
204 	.shutdown =	ng_iface_shutdown,
205 	.newhook =	ng_iface_newhook,
206 	.rcvdata =	ng_iface_rcvdata,
207 	.disconnect =	ng_iface_disconnect,
208 	.cmdlist =	ng_iface_cmds,
209 };
210 NETGRAPH_INIT(iface, &typestruct);
211 
212 static vnet_attach_fn ng_iface_iattach;
213 static vnet_detach_fn ng_iface_idetach;
214 
215 #ifdef VIMAGE_GLOBALS
216 static struct unrhdr	*ng_iface_unit;
217 #endif
218 
219 #ifndef VIMAGE_GLOBALS
220 static vnet_modinfo_t vnet_ng_iface_modinfo = {
221 	.vmi_id		= VNET_MOD_NG_IFACE,
222 	.vmi_name	= "ng_iface",
223 	.vmi_dependson	= VNET_MOD_NETGRAPH,
224 	.vmi_iattach	= ng_iface_iattach,
225 	.vmi_idetach	= ng_iface_idetach
226 };
227 #endif
228 
229 /************************************************************************
230 			HELPER STUFF
231  ************************************************************************/
232 
233 /*
234  * Get the family descriptor from the family ID
235  */
236 static __inline iffam_p
237 get_iffam_from_af(sa_family_t family)
238 {
239 	iffam_p iffam;
240 	int k;
241 
242 	for (k = 0; k < NUM_FAMILIES; k++) {
243 		iffam = &gFamilies[k];
244 		if (iffam->family == family)
245 			return (iffam);
246 	}
247 	return (NULL);
248 }
249 
250 /*
251  * Get the family descriptor from the hook
252  */
253 static __inline iffam_p
254 get_iffam_from_hook(priv_p priv, hook_p hook)
255 {
256 	int k;
257 
258 	for (k = 0; k < NUM_FAMILIES; k++)
259 		if (priv->hooks[k] == hook)
260 			return (&gFamilies[k]);
261 	return (NULL);
262 }
263 
264 /*
265  * Get the hook from the iffam descriptor
266  */
267 
268 static __inline hook_p *
269 get_hook_from_iffam(priv_p priv, iffam_p iffam)
270 {
271 	return (&priv->hooks[iffam - gFamilies]);
272 }
273 
274 /*
275  * Get the iffam descriptor from the name
276  */
277 static __inline iffam_p
278 get_iffam_from_name(const char *name)
279 {
280 	iffam_p iffam;
281 	int k;
282 
283 	for (k = 0; k < NUM_FAMILIES; k++) {
284 		iffam = &gFamilies[k];
285 		if (!strcmp(iffam->hookname, name))
286 			return (iffam);
287 	}
288 	return (NULL);
289 }
290 
291 /************************************************************************
292 			INTERFACE STUFF
293  ************************************************************************/
294 
295 /*
296  * Process an ioctl for the virtual interface
297  */
298 static int
299 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
300 {
301 	struct ifreq *const ifr = (struct ifreq *) data;
302 	int s, error = 0;
303 
304 #ifdef DEBUG
305 	ng_iface_print_ioctl(ifp, command, data);
306 #endif
307 	s = splimp();
308 	switch (command) {
309 
310 	/* These two are mostly handled at a higher layer */
311 	case SIOCSIFADDR:
312 		ifp->if_flags |= IFF_UP;
313 		ifp->if_drv_flags |= IFF_DRV_RUNNING;
314 		ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
315 		break;
316 	case SIOCGIFADDR:
317 		break;
318 
319 	/* Set flags */
320 	case SIOCSIFFLAGS:
321 		/*
322 		 * If the interface is marked up and stopped, then start it.
323 		 * If it is marked down and running, then stop it.
324 		 */
325 		if (ifr->ifr_flags & IFF_UP) {
326 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
327 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
328 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
329 			}
330 		} else {
331 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
332 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
333 				    IFF_DRV_OACTIVE);
334 		}
335 		break;
336 
337 	/* Set the interface MTU */
338 	case SIOCSIFMTU:
339 		if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
340 		    || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
341 			error = EINVAL;
342 		else
343 			ifp->if_mtu = ifr->ifr_mtu;
344 		break;
345 
346 	/* Stuff that's not supported */
347 	case SIOCADDMULTI:
348 	case SIOCDELMULTI:
349 		error = 0;
350 		break;
351 	case SIOCSIFPHYS:
352 		error = EOPNOTSUPP;
353 		break;
354 
355 	default:
356 		error = EINVAL;
357 		break;
358 	}
359 	(void) splx(s);
360 	return (error);
361 }
362 
363 /*
364  * This routine is called to deliver a packet out the interface.
365  * We simply look at the address family and relay the packet to
366  * the corresponding hook, if it exists and is connected.
367  */
368 
369 static int
370 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
371     		struct sockaddr *dst, struct route *ro)
372 {
373 	struct m_tag *mtag;
374 	uint32_t af;
375 	int error;
376 
377 	/* Check interface flags */
378 	if (!((ifp->if_flags & IFF_UP) &&
379 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
380 		m_freem(m);
381 		return (ENETDOWN);
382 	}
383 
384 	/* Protect from deadly infinite recursion. */
385 	while ((mtag = m_tag_locate(m, MTAG_NGIF, MTAG_NGIF_CALLED, NULL))) {
386 		if (*(struct ifnet **)(mtag + 1) == ifp) {
387 			log(LOG_NOTICE, "Loop detected on %s\n", ifp->if_xname);
388 			m_freem(m);
389 			return (EDEADLK);
390 		}
391 	}
392 	mtag = m_tag_alloc(MTAG_NGIF, MTAG_NGIF_CALLED, sizeof(struct ifnet *),
393 	    M_NOWAIT);
394 	if (mtag == NULL) {
395 		m_freem(m);
396 		return (ENOMEM);
397 	}
398 	*(struct ifnet **)(mtag + 1) = ifp;
399 	m_tag_prepend(m, mtag);
400 
401 	/* BPF writes need to be handled specially. */
402 	if (dst->sa_family == AF_UNSPEC) {
403 		bcopy(dst->sa_data, &af, sizeof(af));
404 		dst->sa_family = af;
405 	}
406 
407 	/* Berkeley packet filter */
408 	ng_iface_bpftap(ifp, m, dst->sa_family);
409 
410 	if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
411 		M_PREPEND(m, sizeof(sa_family_t), M_DONTWAIT);
412 		if (m == NULL) {
413 			IFQ_LOCK(&ifp->if_snd);
414 			IFQ_INC_DROPS(&ifp->if_snd);
415 			IFQ_UNLOCK(&ifp->if_snd);
416 			ifp->if_oerrors++;
417 			return (ENOBUFS);
418 		}
419 		*(sa_family_t *)m->m_data = dst->sa_family;
420 		error = (ifp->if_transmit)(ifp, m);
421 	} else
422 		error = ng_iface_send(ifp, m, dst->sa_family);
423 
424 	return (error);
425 }
426 
427 /*
428  * Start method is used only when ALTQ is enabled.
429  */
430 static void
431 ng_iface_start(struct ifnet *ifp)
432 {
433 	struct mbuf *m;
434 	sa_family_t sa;
435 
436 	KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
437 
438 	for(;;) {
439 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
440 		if (m == NULL)
441 			break;
442 		sa = *mtod(m, sa_family_t *);
443 		m_adj(m, sizeof(sa_family_t));
444 		ng_iface_send(ifp, m, sa);
445 	}
446 }
447 
448 /*
449  * Flash a packet by the BPF (requires prepending 4 byte AF header)
450  * Note the phoney mbuf; this is OK because BPF treats it read-only.
451  */
452 static void
453 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
454 {
455 	KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
456 	if (bpf_peers_present(ifp->if_bpf)) {
457 		int32_t family4 = (int32_t)family;
458 		bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
459 	}
460 }
461 
462 /*
463  * This routine does actual delivery of the packet into the
464  * netgraph(4). It is called from ng_iface_start() and
465  * ng_iface_output().
466  */
467 static int
468 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
469 {
470 	const priv_p priv = (priv_p) ifp->if_softc;
471 	const iffam_p iffam = get_iffam_from_af(sa);
472 	int error;
473 	int len;
474 
475 	/* Check address family to determine hook (if known) */
476 	if (iffam == NULL) {
477 		m_freem(m);
478 		log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
479 		return (EAFNOSUPPORT);
480 	}
481 
482 	/* Copy length before the mbuf gets invalidated. */
483 	len = m->m_pkthdr.len;
484 
485 	/* Send packet. If hook is not connected,
486 	   mbuf will get freed. */
487 	NG_SEND_DATA_ONLY(error, *get_hook_from_iffam(priv, iffam), m);
488 
489 	/* Update stats. */
490 	if (error == 0) {
491 		ifp->if_obytes += len;
492 		ifp->if_opackets++;
493 	}
494 
495 	return (error);
496 }
497 
498 #ifdef DEBUG
499 /*
500  * Display an ioctl to the virtual interface
501  */
502 
503 static void
504 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
505 {
506 	char   *str;
507 
508 	switch (command & IOC_DIRMASK) {
509 	case IOC_VOID:
510 		str = "IO";
511 		break;
512 	case IOC_OUT:
513 		str = "IOR";
514 		break;
515 	case IOC_IN:
516 		str = "IOW";
517 		break;
518 	case IOC_INOUT:
519 		str = "IORW";
520 		break;
521 	default:
522 		str = "IO??";
523 	}
524 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
525 	       ifp->if_xname,
526 	       str,
527 	       IOCGROUP(command),
528 	       command & 0xff,
529 	       IOCPARM_LEN(command));
530 }
531 #endif /* DEBUG */
532 
533 /************************************************************************
534 			NETGRAPH NODE STUFF
535  ************************************************************************/
536 
537 /*
538  * Constructor for a node
539  */
540 static int
541 ng_iface_constructor(node_p node)
542 {
543 	INIT_VNET_NETGRAPH(curvnet);
544 	struct ifnet *ifp;
545 	priv_p priv;
546 
547 	/* Allocate node and interface private structures */
548 	priv = malloc(sizeof(*priv), M_NETGRAPH_IFACE, M_NOWAIT|M_ZERO);
549 	if (priv == NULL)
550 		return (ENOMEM);
551 	ifp = if_alloc(IFT_PROPVIRTUAL);
552 	if (ifp == NULL) {
553 		free(priv, M_NETGRAPH_IFACE);
554 		return (ENOMEM);
555 	}
556 
557 	/* Link them together */
558 	ifp->if_softc = priv;
559 	priv->ifp = ifp;
560 
561 	/* Get an interface unit number */
562 	priv->unit = alloc_unr(V_ng_iface_unit);
563 
564 	/* Link together node and private info */
565 	NG_NODE_SET_PRIVATE(node, priv);
566 	priv->node = node;
567 
568 	/* Initialize interface structure */
569 	if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
570 	ifp->if_output = ng_iface_output;
571 	ifp->if_start = ng_iface_start;
572 	ifp->if_ioctl = ng_iface_ioctl;
573 	ifp->if_watchdog = NULL;
574 	ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
575 	ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
576 	ifp->if_type = IFT_PROPVIRTUAL;		/* XXX */
577 	ifp->if_addrlen = 0;			/* XXX */
578 	ifp->if_hdrlen = 0;			/* XXX */
579 	ifp->if_baudrate = 64000;		/* XXX */
580 	IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
581 	ifp->if_snd.ifq_drv_maxlen = IFQ_MAXLEN;
582 	IFQ_SET_READY(&ifp->if_snd);
583 
584 	/* Give this node the same name as the interface (if possible) */
585 	if (ng_name_node(node, ifp->if_xname) != 0)
586 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
587 		    ifp->if_xname);
588 
589 	/* Attach the interface */
590 	if_attach(ifp);
591 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
592 
593 	/* Done */
594 	return (0);
595 }
596 
597 /*
598  * Give our ok for a hook to be added
599  */
600 static int
601 ng_iface_newhook(node_p node, hook_p hook, const char *name)
602 {
603 	const iffam_p iffam = get_iffam_from_name(name);
604 	hook_p *hookptr;
605 
606 	if (iffam == NULL)
607 		return (EPFNOSUPPORT);
608 	hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
609 	if (*hookptr != NULL)
610 		return (EISCONN);
611 	*hookptr = hook;
612 	NG_HOOK_HI_STACK(hook);
613 	return (0);
614 }
615 
616 /*
617  * Receive a control message
618  */
619 static int
620 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
621 {
622 	const priv_p priv = NG_NODE_PRIVATE(node);
623 	struct ifnet *const ifp = priv->ifp;
624 	struct ng_mesg *resp = NULL;
625 	int error = 0;
626 	struct ng_mesg *msg;
627 
628 	NGI_GET_MSG(item, msg);
629 	switch (msg->header.typecookie) {
630 	case NGM_IFACE_COOKIE:
631 		switch (msg->header.cmd) {
632 		case NGM_IFACE_GET_IFNAME:
633 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
634 			if (resp == NULL) {
635 				error = ENOMEM;
636 				break;
637 			}
638 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
639 			break;
640 
641 		case NGM_IFACE_POINT2POINT:
642 		case NGM_IFACE_BROADCAST:
643 		    {
644 
645 			/* Deny request if interface is UP */
646 			if ((ifp->if_flags & IFF_UP) != 0)
647 				return (EBUSY);
648 
649 			/* Change flags */
650 			switch (msg->header.cmd) {
651 			case NGM_IFACE_POINT2POINT:
652 				ifp->if_flags |= IFF_POINTOPOINT;
653 				ifp->if_flags &= ~IFF_BROADCAST;
654 				break;
655 			case NGM_IFACE_BROADCAST:
656 				ifp->if_flags &= ~IFF_POINTOPOINT;
657 				ifp->if_flags |= IFF_BROADCAST;
658 				break;
659 			}
660 			break;
661 		    }
662 
663 		case NGM_IFACE_GET_IFINDEX:
664 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
665 			if (resp == NULL) {
666 				error = ENOMEM;
667 				break;
668 			}
669 			*((uint32_t *)resp->data) = priv->ifp->if_index;
670 			break;
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 			IF_ADDR_LOCK(ifp);
685 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
686 				struct ng_cisco_ipaddr *ips;
687 
688 				if (ifa->ifa_addr->sa_family != AF_INET)
689 					continue;
690 				NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
691 				if (resp == NULL) {
692 					error = ENOMEM;
693 					break;
694 				}
695 				ips = (struct ng_cisco_ipaddr *)resp->data;
696 				ips->ipaddr = ((struct sockaddr_in *)
697 						ifa->ifa_addr)->sin_addr;
698 				ips->netmask = ((struct sockaddr_in *)
699 						ifa->ifa_netmask)->sin_addr;
700 				break;
701 			}
702 			IF_ADDR_UNLOCK(ifp);
703 
704 			/* No IP addresses on this interface? */
705 			if (ifa == NULL)
706 				error = EADDRNOTAVAIL;
707 			break;
708 		    }
709 		default:
710 			error = EINVAL;
711 			break;
712 		}
713 		break;
714 	case NGM_FLOW_COOKIE:
715 		switch (msg->header.cmd) {
716 		case NGM_LINK_IS_UP:
717 			ifp->if_drv_flags |= IFF_DRV_RUNNING;
718 			break;
719 		case NGM_LINK_IS_DOWN:
720 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
721 			break;
722 		default:
723 			break;
724 		}
725 		break;
726 	default:
727 		error = EINVAL;
728 		break;
729 	}
730 	NG_RESPOND_MSG(error, node, item, resp);
731 	NG_FREE_MSG(msg);
732 	return (error);
733 }
734 
735 /*
736  * Recive data from a hook. Pass the packet to the correct input routine.
737  */
738 static int
739 ng_iface_rcvdata(hook_p hook, item_p item)
740 {
741 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
742 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
743 	struct ifnet *const ifp = priv->ifp;
744 	struct mbuf *m;
745 	int isr;
746 
747 	NGI_GET_M(item, m);
748 	NG_FREE_ITEM(item);
749 	/* Sanity checks */
750 	KASSERT(iffam != NULL, ("%s: iffam", __func__));
751 	M_ASSERTPKTHDR(m);
752 	if ((ifp->if_flags & IFF_UP) == 0) {
753 		NG_FREE_M(m);
754 		return (ENETDOWN);
755 	}
756 
757 	/* Update interface stats */
758 	ifp->if_ipackets++;
759 	ifp->if_ibytes += m->m_pkthdr.len;
760 
761 	/* Note receiving interface */
762 	m->m_pkthdr.rcvif = ifp;
763 
764 	/* Berkeley packet filter */
765 	ng_iface_bpftap(ifp, m, iffam->family);
766 
767 	/* Send packet */
768 	switch (iffam->family) {
769 #ifdef INET
770 	case AF_INET:
771 		isr = NETISR_IP;
772 		break;
773 #endif
774 #ifdef INET6
775 	case AF_INET6:
776 		isr = NETISR_IPV6;
777 		break;
778 #endif
779 #ifdef IPX
780 	case AF_IPX:
781 		isr = NETISR_IPX;
782 		break;
783 #endif
784 #ifdef NETATALK
785 	case AF_APPLETALK:
786 		isr = NETISR_ATALK2;
787 		break;
788 #endif
789 	default:
790 		m_freem(m);
791 		return (EAFNOSUPPORT);
792 	}
793 	/* First chunk of an mbuf contains good junk */
794 	if (harvest.point_to_point)
795 		random_harvest(m, 16, 3, 0, RANDOM_NET);
796 	netisr_dispatch(isr, m);
797 	return (0);
798 }
799 
800 /*
801  * Shutdown and remove the node and its associated interface.
802  */
803 static int
804 ng_iface_shutdown(node_p node)
805 {
806 	INIT_VNET_NETGRAPH(curvnet);
807 	const priv_p priv = NG_NODE_PRIVATE(node);
808 
809 	/*
810 	 * The ifnet may be in a different vnet than the netgraph node,
811 	 * hence we have to change the current vnet context here.
812 	 */
813 	CURVNET_SET_QUIET(priv->ifp->if_vnet);
814 	bpfdetach(priv->ifp);
815 	if_detach(priv->ifp);
816 	if_free(priv->ifp);
817 	CURVNET_RESTORE();
818 	priv->ifp = NULL;
819 	free_unr(V_ng_iface_unit, priv->unit);
820 	free(priv, M_NETGRAPH_IFACE);
821 	NG_NODE_SET_PRIVATE(node, NULL);
822 	NG_NODE_UNREF(node);
823 	return (0);
824 }
825 
826 /*
827  * Hook disconnection. Note that we do *not* shutdown when all
828  * hooks have been disconnected.
829  */
830 static int
831 ng_iface_disconnect(hook_p hook)
832 {
833 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
834 	const iffam_p iffam = get_iffam_from_hook(priv, hook);
835 
836 	if (iffam == NULL)
837 		panic(__func__);
838 	*get_hook_from_iffam(priv, iffam) = NULL;
839 	return (0);
840 }
841 
842 /*
843  * Handle loading and unloading for this node type.
844  */
845 static int
846 ng_iface_mod_event(module_t mod, int event, void *data)
847 {
848 	int error = 0;
849 
850 	switch (event) {
851 	case MOD_LOAD:
852 #ifndef VIMAGE_GLOBALS
853 		vnet_mod_register(&vnet_ng_iface_modinfo);
854 #else
855 		ng_iface_iattach(NULL);
856 #endif
857 		break;
858 	case MOD_UNLOAD:
859 #ifndef VIMAGE_GLOBALS
860 		vnet_mod_deregister(&vnet_ng_iface_modinfo);
861 #else
862 		ng_iface_idetach(NULL);
863 #endif
864 		break;
865 	default:
866 		error = EOPNOTSUPP;
867 		break;
868 	}
869 	return (error);
870 }
871 
872 static int ng_iface_iattach(const void *unused)
873 {
874 	INIT_VNET_NETGRAPH(curvnet);
875 
876 	V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
877 
878 	return (0);
879 }
880 
881 static int ng_iface_idetach(const void *unused)
882 {
883 	INIT_VNET_NETGRAPH(curvnet);
884 
885 	delete_unrhdr(V_ng_iface_unit);
886 
887 	return (0);
888 }
889