ng_eiface.c revision 202588 
1/*-
2 *
3 * Copyright (c) 1999-2001, Vitaly V Belekhov
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice unmodified, this list of conditions, and the following
11 *    disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: head/sys/netgraph/ng_eiface.c 202588 2010-01-18 20:34:00Z thompsa $
29 */
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/errno.h>
34#include <sys/kernel.h>
35#include <sys/malloc.h>
36#include <sys/mbuf.h>
37#include <sys/errno.h>
38#include <sys/proc.h>
39#include <sys/sockio.h>
40#include <sys/socket.h>
41#include <sys/syslog.h>
42
43#include <net/if.h>
44#include <net/if_types.h>
45#include <net/netisr.h>
46#include <net/route.h>
47#include <net/vnet.h>
48
49#include <netgraph/ng_message.h>
50#include <netgraph/netgraph.h>
51#include <netgraph/ng_parse.h>
52#include <netgraph/ng_eiface.h>
53
54#include <net/bpf.h>
55#include <net/ethernet.h>
56#include <net/if_arp.h>
57
58static const struct ng_cmdlist ng_eiface_cmdlist[] = {
59	{
60	  NGM_EIFACE_COOKIE,
61	  NGM_EIFACE_GET_IFNAME,
62	  "getifname",
63	  NULL,
64	  &ng_parse_string_type
65	},
66	{
67	  NGM_EIFACE_COOKIE,
68	  NGM_EIFACE_SET,
69	  "set",
70	  &ng_parse_enaddr_type,
71	  NULL
72	},
73	{ 0 }
74};
75
76/* Node private data */
77struct ng_eiface_private {
78	struct ifnet	*ifp;		/* per-interface network data */
79	int		unit;		/* Interface unit number */
80	node_p		node;		/* Our netgraph node */
81	hook_p		ether;		/* Hook for ethernet stream */
82};
83typedef struct ng_eiface_private *priv_p;
84
85/* Interface methods */
86static void	ng_eiface_init(void *xsc);
87static void	ng_eiface_start(struct ifnet *ifp);
88static int	ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
89#ifdef DEBUG
90static void	ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
91#endif
92
93/* Netgraph methods */
94static int		ng_eiface_mod_event(module_t, int, void *);
95static ng_constructor_t	ng_eiface_constructor;
96static ng_rcvmsg_t	ng_eiface_rcvmsg;
97static ng_shutdown_t	ng_eiface_rmnode;
98static ng_newhook_t	ng_eiface_newhook;
99static ng_rcvdata_t	ng_eiface_rcvdata;
100static ng_disconnect_t	ng_eiface_disconnect;
101
102/* Node type descriptor */
103static struct ng_type typestruct = {
104	.version =	NG_ABI_VERSION,
105	.name =		NG_EIFACE_NODE_TYPE,
106	.mod_event =	ng_eiface_mod_event,
107	.constructor =	ng_eiface_constructor,
108	.rcvmsg =	ng_eiface_rcvmsg,
109	.shutdown =	ng_eiface_rmnode,
110	.newhook =	ng_eiface_newhook,
111	.rcvdata =	ng_eiface_rcvdata,
112	.disconnect =	ng_eiface_disconnect,
113	.cmdlist =	ng_eiface_cmdlist
114};
115NETGRAPH_INIT(eiface, &typestruct);
116
117static VNET_DEFINE(struct unrhdr *, ng_eiface_unit);
118#define	V_ng_eiface_unit		VNET(ng_eiface_unit)
119
120/************************************************************************
121			INTERFACE STUFF
122 ************************************************************************/
123
124/*
125 * Process an ioctl for the virtual interface
126 */
127static int
128ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
129{
130	struct ifreq *const ifr = (struct ifreq *)data;
131	int s, error = 0;
132
133#ifdef DEBUG
134	ng_eiface_print_ioctl(ifp, command, data);
135#endif
136	s = splimp();
137	switch (command) {
138
139	/* These two are mostly handled at a higher layer */
140	case SIOCSIFADDR:
141		error = ether_ioctl(ifp, command, data);
142		break;
143	case SIOCGIFADDR:
144		break;
145
146	/* Set flags */
147	case SIOCSIFFLAGS:
148		/*
149		 * If the interface is marked up and stopped, then start it.
150		 * If it is marked down and running, then stop it.
151		 */
152		if (ifp->if_flags & IFF_UP) {
153			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
154				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
155				ifp->if_drv_flags |= IFF_DRV_RUNNING;
156			}
157		} else {
158			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
159				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
160				    IFF_DRV_OACTIVE);
161		}
162		break;
163
164	/* Set the interface MTU */
165	case SIOCSIFMTU:
166		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX ||
167		    ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
168			error = EINVAL;
169		else
170			ifp->if_mtu = ifr->ifr_mtu;
171		break;
172
173	/* Stuff that's not supported */
174	case SIOCADDMULTI:
175	case SIOCDELMULTI:
176		error = 0;
177		break;
178	case SIOCSIFPHYS:
179		error = EOPNOTSUPP;
180		break;
181
182	default:
183		error = EINVAL;
184		break;
185	}
186	splx(s);
187	return (error);
188}
189
190static void
191ng_eiface_init(void *xsc)
192{
193	priv_p sc = xsc;
194	struct ifnet *ifp = sc->ifp;
195	int s;
196
197	s = splimp();
198
199	ifp->if_drv_flags |= IFF_DRV_RUNNING;
200	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
201
202	splx(s);
203}
204
205/*
206 * We simply relay the packet to the "ether" hook, if it is connected.
207 * We have been through the netgraph locking and are guaranteed to
208 * be the only code running in this node at this time.
209 */
210static void
211ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
212{
213	struct ifnet *ifp = arg1;
214	const priv_p priv = (priv_p)ifp->if_softc;
215	int error = 0;
216	struct mbuf *m;
217
218	/* Check interface flags */
219
220	if (!((ifp->if_flags & IFF_UP) &&
221	    (ifp->if_drv_flags & IFF_DRV_RUNNING)))
222		return;
223
224	for (;;) {
225		/*
226		 * Grab a packet to transmit.
227		 */
228		IF_DEQUEUE(&ifp->if_snd, m);
229
230		/* If there's nothing to send, break. */
231		if (m == NULL)
232			break;
233
234		/*
235		 * Berkeley packet filter.
236		 * Pass packet to bpf if there is a listener.
237		 * XXX is this safe? locking?
238		 */
239		BPF_MTAP(ifp, m);
240
241		if (ifp->if_flags & IFF_MONITOR) {
242			ifp->if_ipackets++;
243			m_freem(m);
244			continue;
245		}
246
247		/*
248		 * Send packet; if hook is not connected, mbuf will get
249		 * freed.
250		 */
251		NG_OUTBOUND_THREAD_REF();
252		NG_SEND_DATA_ONLY(error, priv->ether, m);
253		NG_OUTBOUND_THREAD_UNREF();
254
255		/* Update stats */
256		if (error == 0)
257			ifp->if_opackets++;
258		else
259			ifp->if_oerrors++;
260	}
261
262	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
263
264	return;
265}
266
267/*
268 * This routine is called to deliver a packet out the interface.
269 * We simply queue the netgraph version to be called when netgraph locking
270 * allows it to happen.
271 * Until we know what the rest of the networking code is doing for
272 * locking, we don't know how we will interact with it.
273 * Take comfort from the fact that the ifnet struct is part of our
274 * private info and can't go away while we are queued.
275 * [Though we don't know it is still there now....]
276 * it is possible we don't gain anything from this because
277 * we would like to get the mbuf and queue it as data
278 * somehow, but we can't and if we did would we solve anything?
279 */
280static void
281ng_eiface_start(struct ifnet *ifp)
282{
283
284	const priv_p priv = (priv_p)ifp->if_softc;
285
286	/* Don't do anything if output is active */
287	if (ifp->if_drv_flags & IFF_DRV_OACTIVE)
288		return;
289
290	ifp->if_drv_flags |= IFF_DRV_OACTIVE;
291
292	if (ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0) != 0)
293		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
294}
295
296#ifdef DEBUG
297/*
298 * Display an ioctl to the virtual interface
299 */
300
301static void
302ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
303{
304	char *str;
305
306	switch (command & IOC_DIRMASK) {
307	case IOC_VOID:
308		str = "IO";
309		break;
310	case IOC_OUT:
311		str = "IOR";
312		break;
313	case IOC_IN:
314		str = "IOW";
315		break;
316	case IOC_INOUT:
317		str = "IORW";
318		break;
319	default:
320		str = "IO??";
321	}
322	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
323	    ifp->if_xname,
324	    str,
325	    IOCGROUP(command),
326	    command & 0xff,
327	    IOCPARM_LEN(command));
328}
329#endif /* DEBUG */
330
331/************************************************************************
332			NETGRAPH NODE STUFF
333 ************************************************************************/
334
335/*
336 * Constructor for a node
337 */
338static int
339ng_eiface_constructor(node_p node)
340{
341	struct ifnet *ifp;
342	priv_p priv;
343	u_char eaddr[6] = {0,0,0,0,0,0};
344
345	/* Allocate node and interface private structures */
346	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
347	if (priv == NULL)
348		return (ENOMEM);
349
350	ifp = priv->ifp = if_alloc(IFT_ETHER);
351	if (ifp == NULL) {
352		free(priv, M_NETGRAPH);
353		return (ENOSPC);
354	}
355
356	/* Link them together */
357	ifp->if_softc = priv;
358
359	/* Get an interface unit number */
360	priv->unit = alloc_unr(V_ng_eiface_unit);
361
362	/* Link together node and private info */
363	NG_NODE_SET_PRIVATE(node, priv);
364	priv->node = node;
365
366	/* Initialize interface structure */
367	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
368	ifp->if_init = ng_eiface_init;
369	ifp->if_output = ether_output;
370	ifp->if_start = ng_eiface_start;
371	ifp->if_ioctl = ng_eiface_ioctl;
372	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
373	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
374
375	/* Give this node the same name as the interface (if possible) */
376	if (ng_name_node(node, ifp->if_xname) != 0)
377		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
378		    ifp->if_xname);
379
380	/* Attach the interface */
381	ether_ifattach(ifp, eaddr);
382
383	/* Done */
384	return (0);
385}
386
387/*
388 * Give our ok for a hook to be added
389 */
390static int
391ng_eiface_newhook(node_p node, hook_p hook, const char *name)
392{
393	priv_p priv = NG_NODE_PRIVATE(node);
394	struct ifnet *ifp = priv->ifp;
395
396	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
397		return (EPFNOSUPPORT);
398	if (priv->ether != NULL)
399		return (EISCONN);
400	priv->ether = hook;
401	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
402	NG_HOOK_SET_TO_INBOUND(hook);
403
404	if_link_state_change(ifp, LINK_STATE_UP);
405
406	return (0);
407}
408
409/*
410 * Receive a control message
411 */
412static int
413ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
414{
415	const priv_p priv = NG_NODE_PRIVATE(node);
416	struct ifnet *const ifp = priv->ifp;
417	struct ng_mesg *resp = NULL;
418	int error = 0;
419	struct ng_mesg *msg;
420
421	NGI_GET_MSG(item, msg);
422	switch (msg->header.typecookie) {
423	case NGM_EIFACE_COOKIE:
424		switch (msg->header.cmd) {
425
426		case NGM_EIFACE_SET:
427		    {
428			if (msg->header.arglen != ETHER_ADDR_LEN) {
429				error = EINVAL;
430				break;
431			}
432			error = if_setlladdr(priv->ifp,
433			    (u_char *)msg->data, ETHER_ADDR_LEN);
434			EVENTHANDLER_INVOKE(iflladdr_event, priv->ifp);
435			break;
436		    }
437
438		case NGM_EIFACE_GET_IFNAME:
439			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
440			if (resp == NULL) {
441				error = ENOMEM;
442				break;
443			}
444			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
445			break;
446
447		case NGM_EIFACE_GET_IFADDRS:
448		    {
449			struct ifaddr *ifa;
450			caddr_t ptr;
451			int buflen;
452
453			/* Determine size of response and allocate it */
454			buflen = 0;
455			if_addr_rlock(ifp);
456			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
457				buflen += SA_SIZE(ifa->ifa_addr);
458			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
459			if (resp == NULL) {
460				if_addr_runlock(ifp);
461				error = ENOMEM;
462				break;
463			}
464
465			/* Add addresses */
466			ptr = resp->data;
467			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
468				const int len = SA_SIZE(ifa->ifa_addr);
469
470				if (buflen < len) {
471					log(LOG_ERR, "%s: len changed?\n",
472					    ifp->if_xname);
473					break;
474				}
475				bcopy(ifa->ifa_addr, ptr, len);
476				ptr += len;
477				buflen -= len;
478			}
479			if_addr_runlock(ifp);
480			break;
481		    }
482
483		default:
484			error = EINVAL;
485			break;
486		} /* end of inner switch() */
487		break;
488	case NGM_FLOW_COOKIE:
489		switch (msg->header.cmd) {
490		case NGM_LINK_IS_UP:
491			if_link_state_change(ifp, LINK_STATE_UP);
492			break;
493		case NGM_LINK_IS_DOWN:
494			if_link_state_change(ifp, LINK_STATE_DOWN);
495			break;
496		default:
497			break;
498		}
499		break;
500	default:
501		error = EINVAL;
502		break;
503	}
504	NG_RESPOND_MSG(error, node, item, resp);
505	NG_FREE_MSG(msg);
506	return (error);
507}
508
509/*
510 * Receive data from a hook. Pass the packet to the ether_input routine.
511 */
512static int
513ng_eiface_rcvdata(hook_p hook, item_p item)
514{
515	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
516	struct ifnet *const ifp = priv->ifp;
517	struct mbuf *m;
518
519	NGI_GET_M(item, m);
520	NG_FREE_ITEM(item);
521
522	if (!((ifp->if_flags & IFF_UP) &&
523	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
524		NG_FREE_M(m);
525		return (ENETDOWN);
526	}
527
528	if (m->m_len < ETHER_HDR_LEN) {
529		m = m_pullup(m, ETHER_HDR_LEN);
530		if (m == NULL)
531			return (EINVAL);
532	}
533
534	/* Note receiving interface */
535	m->m_pkthdr.rcvif = ifp;
536
537	/* Update interface stats */
538	ifp->if_ipackets++;
539
540	(*ifp->if_input)(ifp, m);
541
542	/* Done */
543	return (0);
544}
545
546/*
547 * Shutdown processing.
548 */
549static int
550ng_eiface_rmnode(node_p node)
551{
552	const priv_p priv = NG_NODE_PRIVATE(node);
553	struct ifnet *const ifp = priv->ifp;
554
555	/*
556	 * the ifnet may be in a different vnet than the netgraph node,
557	 * hence we have to change the current vnet context here.
558	 */
559	CURVNET_SET_QUIET(ifp->if_vnet);
560	ether_ifdetach(ifp);
561	if_free(ifp);
562	CURVNET_RESTORE();
563	free_unr(V_ng_eiface_unit, priv->unit);
564	free(priv, M_NETGRAPH);
565	NG_NODE_SET_PRIVATE(node, NULL);
566	NG_NODE_UNREF(node);
567	return (0);
568}
569
570/*
571 * Hook disconnection
572 */
573static int
574ng_eiface_disconnect(hook_p hook)
575{
576	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
577
578	priv->ether = NULL;
579	return (0);
580}
581
582/*
583 * Handle loading and unloading for this node type.
584 */
585static int
586ng_eiface_mod_event(module_t mod, int event, void *data)
587{
588	int error = 0;
589
590	switch (event) {
591	case MOD_LOAD:
592	case MOD_UNLOAD:
593		break;
594	default:
595		error = EOPNOTSUPP;
596		break;
597	}
598	return (error);
599}
600
601static void
602vnet_ng_eiface_init(const void *unused)
603{
604
605	V_ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
606}
607VNET_SYSINIT(vnet_ng_eiface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
608    vnet_ng_eiface_init, NULL);
609
610static void
611vnet_ng_eiface_uninit(const void *unused)
612{
613
614	delete_unrhdr(V_ng_eiface_unit);
615}
616VNET_SYSUNINIT(vnet_ng_eiface_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY,
617   vnet_ng_eiface_uninit, NULL);
618