ng_eiface.c revision 135075 
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 135075 2004-09-11 08:59:06Z glebius $
29 */
30
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/errno.h>
35#include <sys/kernel.h>
36#include <sys/lock.h>
37#include <sys/malloc.h>
38#include <sys/mbuf.h>
39#include <sys/mutex.h>
40#include <sys/errno.h>
41#include <sys/sockio.h>
42#include <sys/socket.h>
43#include <sys/syslog.h>
44
45#include <net/if.h>
46#include <net/if_dl.h>
47#include <net/if_types.h>
48#include <net/netisr.h>
49
50#include <netinet/in.h>
51#include <netinet/if_ether.h>
52
53#include <netgraph/ng_message.h>
54#include <netgraph/netgraph.h>
55#include <netgraph/ng_parse.h>
56#include <netgraph/ng_eiface.h>
57
58#include <net/bpf.h>
59#include <net/ethernet.h>
60#include <net/if_arp.h>
61
62static const struct ng_cmdlist ng_eiface_cmdlist[] = {
63	{
64	  NGM_EIFACE_COOKIE,
65	  NGM_EIFACE_SET,
66	  "set",
67	  &ng_parse_enaddr_type,
68	  NULL
69	},
70	{ 0 }
71};
72
73
74/* Node private data */
75struct ng_eiface_private {
76	struct arpcom   arpcom;	/* per-interface network data */
77	struct ifnet   *ifp;	/* This interface */
78	int	unit;		/* Interface unit number */
79	node_p		node;	/* Our netgraph node */
80	hook_p		ether;	/* Hook for ethernet stream */
81};
82typedef struct ng_eiface_private *priv_p;
83
84/* Interface methods */
85static void     ng_eiface_init(void *xsc);
86static void     ng_eiface_start(struct ifnet *ifp);
87static int      ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
88#ifdef DEBUG
89static void     ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
90#endif
91
92/* Netgraph methods */
93static ng_constructor_t ng_eiface_constructor;
94static ng_rcvmsg_t ng_eiface_rcvmsg;
95static ng_shutdown_t ng_eiface_rmnode;
96static ng_newhook_t ng_eiface_newhook;
97static ng_rcvdata_t ng_eiface_rcvdata;
98static ng_connect_t ng_eiface_connect;
99static ng_disconnect_t ng_eiface_disconnect;
100
101/* Node type descriptor */
102static struct ng_type typestruct = {
103	.version =	NG_ABI_VERSION,
104	.name =		NG_EIFACE_NODE_TYPE,
105	.constructor =	ng_eiface_constructor,
106	.rcvmsg =	ng_eiface_rcvmsg,
107	.shutdown =	ng_eiface_rmnode,
108	.newhook =	ng_eiface_newhook,
109	.connect =	ng_eiface_connect,
110	.rcvdata =	ng_eiface_rcvdata,
111	.disconnect =	ng_eiface_disconnect,
112	.cmdlist =	ng_eiface_cmdlist
113};
114NETGRAPH_INIT(eiface, &typestruct);
115
116/* We keep a bitmap indicating which unit numbers are free.
117   One means the unit number is free, zero means it's taken. */
118static int	*ng_eiface_units = NULL;
119static int	ng_eiface_units_len = 0;
120static int	ng_units_in_use = 0;
121
122#define UNITS_BITSPERWORD	(sizeof(*ng_eiface_units) * NBBY)
123
124static struct mtx	ng_eiface_mtx;
125MTX_SYSINIT(ng_eiface, &ng_eiface_mtx, "ng_eiface", MTX_DEF);
126
127/************************************************************************
128			HELPER STUFF
129 ************************************************************************/
130/*
131 * Find the first free unit number for a new interface.
132 * Increase the size of the unit bitmap as necessary.
133 */
134static __inline int
135ng_eiface_get_unit(int *unit)
136{
137	int index, bit;
138
139	mtx_lock(&ng_eiface_mtx);
140	for (index = 0; index < ng_eiface_units_len
141	    && ng_eiface_units[index] == 0; index++);
142	if (index == ng_eiface_units_len) {		/* extend array */
143		int i, *newarray, newlen;
144
145		newlen = (2 * ng_eiface_units_len) + 4;
146		MALLOC(newarray, int *, newlen * sizeof(*ng_eiface_units),
147		    M_NETGRAPH, M_NOWAIT);
148		if (newarray == NULL) {
149			mtx_unlock(&ng_eiface_mtx);
150			return (ENOMEM);
151		}
152		bcopy(ng_eiface_units, newarray,
153		    ng_eiface_units_len * sizeof(*ng_eiface_units));
154		for (i = ng_eiface_units_len; i < newlen; i++)
155			newarray[i] = ~0;
156		if (ng_eiface_units != NULL)
157			FREE(ng_eiface_units, M_NETGRAPH);
158		ng_eiface_units = newarray;
159		ng_eiface_units_len = newlen;
160	}
161	bit = ffs(ng_eiface_units[index]) - 1;
162	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
163	    ("%s: word=%d bit=%d", __func__, ng_eiface_units[index], bit));
164	ng_eiface_units[index] &= ~(1 << bit);
165	*unit = (index * UNITS_BITSPERWORD) + bit;
166	ng_units_in_use++;
167	mtx_unlock(&ng_eiface_mtx);
168	return (0);
169}
170
171/*
172 * Free a no longer needed unit number.
173 */
174static __inline void
175ng_eiface_free_unit(int unit)
176{
177	int index, bit;
178
179	index = unit / UNITS_BITSPERWORD;
180	bit = unit % UNITS_BITSPERWORD;
181	mtx_lock(&ng_eiface_mtx);
182	KASSERT(index < ng_eiface_units_len,
183	    ("%s: unit=%d len=%d", __func__, unit, ng_eiface_units_len));
184	KASSERT((ng_eiface_units[index] & (1 << bit)) == 0,
185	    ("%s: unit=%d is free", __func__, unit));
186	ng_eiface_units[index] |= (1 << bit);
187	/*
188	 * XXX We could think about reducing the size of ng_eiface_units[]
189	 * XXX here if the last portion is all ones
190	 * XXX At least free it if no more units.
191	 * Needed if we are to eventually be able to unload.
192	 */
193	ng_units_in_use--;
194	if (ng_units_in_use == 0) { /* XXX make SMP safe */
195		FREE(ng_eiface_units, M_NETGRAPH);
196		ng_eiface_units_len = 0;
197		ng_eiface_units = NULL;
198	}
199	mtx_unlock(&ng_eiface_mtx);
200}
201
202/************************************************************************
203			INTERFACE STUFF
204 ************************************************************************/
205
206/*
207 * Process an ioctl for the virtual interface
208 */
209static int
210ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
211{
212	struct ifreq   *const ifr = (struct ifreq *)data;
213	int		s, error = 0;
214
215#ifdef DEBUG
216	ng_eiface_print_ioctl(ifp, command, data);
217#endif
218	s = splimp();
219	switch (command)
220	{
221	/* These two are mostly handled at a higher layer */
222	case SIOCSIFADDR:
223		error = ether_ioctl(ifp, command, data);
224		break;
225	case SIOCGIFADDR:
226		break;
227
228	/* Set flags */
229	case SIOCSIFFLAGS:
230		/*
231		 * If the interface is marked up and stopped, then
232		 * start it. If it is marked down and running,
233		 * then stop it.
234		 */
235		if (ifr->ifr_flags & IFF_UP) {
236			if (!(ifp->if_flags & IFF_RUNNING)) {
237				ifp->if_flags &= ~(IFF_OACTIVE);
238				ifp->if_flags |= IFF_RUNNING;
239			}
240		} else {
241			if (ifp->if_flags & IFF_RUNNING)
242				ifp->if_flags
243					&= ~(IFF_RUNNING | IFF_OACTIVE);
244		}
245		break;
246
247	/* Set the interface MTU */
248	case SIOCSIFMTU:
249		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX
250		|| ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
251			error = EINVAL;
252		else
253			ifp->if_mtu = ifr->ifr_mtu;
254		break;
255
256	/* Stuff that's not supported */
257	case SIOCADDMULTI:
258	case SIOCDELMULTI:
259		error = 0;
260		break;
261	case SIOCSIFPHYS:
262		error = EOPNOTSUPP;
263		break;
264
265	default:
266		error = EINVAL;
267		break;
268	}
269	(void)splx(s);
270	return (error);
271}
272
273static void
274ng_eiface_init(void *xsc)
275{
276	priv_p		sc = xsc;
277	struct ifnet   *ifp = sc->ifp;
278	int		s;
279
280	s = splimp();
281
282	ifp->if_flags |= IFF_RUNNING;
283	ifp->if_flags &= ~IFF_OACTIVE;
284
285	splx(s);
286}
287
288/*
289 * We simply relay the packet to the ether hook, if it is connected.
290 * We have been throughthe netgraph locking an are guaranteed to
291 * be the only code running in this node at this time.
292 */
293static void
294ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
295{
296	struct ifnet *ifp = arg1;
297	const priv_p priv = (priv_p) ifp->if_softc;
298	int		len, error = 0;
299	struct mbuf    *m;
300
301	/* Check interface flags */
302	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
303		return;
304
305	/* Don't do anything if output is active */
306	if (ifp->if_flags & IFF_OACTIVE)
307		return;
308
309	ifp->if_flags |= IFF_OACTIVE;
310
311	/*
312	 * Grab a packet to transmit.
313	 */
314	IF_DEQUEUE(&ifp->if_snd, m);
315
316	/* If there's nothing to send, return. */
317	if (m == NULL) {
318		ifp->if_flags &= ~IFF_OACTIVE;
319		return;
320	}
321
322	/* Berkeley packet filter
323	 * Pass packet to bpf if there is a listener.
324	 * XXX is this safe? locking?
325	 */
326	BPF_MTAP(ifp, m);
327
328	/* Copy length before the mbuf gets invalidated */
329	len = m->m_pkthdr.len;
330
331	/*
332	 * Send packet; if hook is not connected, mbuf will get
333	 * freed.
334	 */
335	NG_SEND_DATA_ONLY(error, priv->ether, m);
336
337	/* Update stats */
338	if (error == 0) {
339		ifp->if_obytes += len;
340		ifp->if_opackets++;
341	}
342	ifp->if_flags &= ~IFF_OACTIVE;
343	return;
344}
345
346/*
347 * This routine is called to deliver a packet out the interface.
348 * We simply queue the netgraph version to be called when netgraph locking
349 * allows it to happen.
350 * Until we know what the rest of the networking code is doing for
351 * locking, we don't know how we will interact with it.
352 * Take comfort from the fact that the ifnet struct is part of our
353 * private info and can't go away while we are queued.
354 * [Though we don't know it is still there now....]
355 * it is possible we don't gain anything from this because
356 * we would like to get the mbuf and queue it as data
357 * somehow, but we can't and if we did would we solve anything?
358 */
359static void
360ng_eiface_start(struct ifnet *ifp)
361{
362
363	const priv_p priv = (priv_p) ifp->if_softc;
364
365	ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0);
366}
367
368#ifdef DEBUG
369/*
370 * Display an ioctl to the virtual interface
371 */
372
373static void
374ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data){
375	char		*str;
376
377	switch (command & IOC_DIRMASK)
378	{
379	case IOC_VOID:
380		str = "IO";
381		break;
382	case IOC_OUT:
383		str = "IOR";
384		break;
385	case IOC_IN:
386		str = "IOW";
387		break;
388	case IOC_INOUT:
389		str = "IORW";
390		break;
391	default:
392		str = "IO??";
393	}
394	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
395			ifp->if_xname,
396			str,
397			IOCGROUP(command),
398			command & 0xff,
399			IOCPARM_LEN(command));
400}
401#endif	/* DEBUG */
402
403/************************************************************************
404			NETGRAPH NODE STUFF
405 ************************************************************************/
406
407/*
408 * Constructor for a node
409 */
410static int
411ng_eiface_constructor(node_p node)
412{
413	struct ifnet   *ifp;
414	priv_p		priv;
415	int		error = 0;
416
417	/* Allocate node and interface private structures */
418	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
419	if (priv == NULL) {
420		return (ENOMEM);
421	}
422	bzero(priv, sizeof(*priv));
423
424	ifp = &(priv->arpcom.ac_if);
425
426	/* Link them together */
427	ifp->if_softc = priv;
428	priv->ifp = ifp;
429
430	/* Get an interface unit number */
431	if ((error = ng_eiface_get_unit(&priv->unit)) != 0) {
432		FREE(priv, M_NETGRAPH);
433		return (error);
434	}
435
436	/* Link together node and private info */
437	NG_NODE_SET_PRIVATE(node, priv);
438	priv->node = node;
439
440	/* Initialize interface structure */
441	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
442	ifp->if_init = ng_eiface_init;
443	ifp->if_output = ether_output;
444	ifp->if_start = ng_eiface_start;
445	ifp->if_ioctl = ng_eiface_ioctl;
446	ifp->if_watchdog = NULL;
447	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
448	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
449
450	/*
451	 * Give this node name * bzero(ifname, sizeof(ifname));
452	 * sprintf(ifname, "if%s", ifp->if_xname); (void)
453	 * ng_name_node(node, ifname);
454	 */
455
456	/* Attach the interface */
457	ether_ifattach(ifp, priv->arpcom.ac_enaddr);
458
459	/* Done */
460	return (0);
461}
462
463/*
464 * Give our ok for a hook to be added
465 */
466static int
467ng_eiface_newhook(node_p node, hook_p hook, const char *name)
468{
469	priv_p		priv = NG_NODE_PRIVATE(node);
470
471	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
472		return (EPFNOSUPPORT);
473	if (priv->ether != NULL)
474		return (EISCONN);
475	priv->ether = hook;
476	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
477
478	return (0);
479}
480
481/*
482 * Receive a control message
483 */
484static int
485ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
486{
487	priv_p		priv = NG_NODE_PRIVATE(node);
488	struct ifnet   *const ifp = priv->ifp;
489	struct ng_mesg *resp = NULL;
490	int		error = 0;
491	struct ng_mesg *msg;
492
493	NGI_GET_MSG(item, msg);
494	switch		(msg->header.typecookie) {
495	case NGM_EIFACE_COOKIE:
496		switch (msg->header.cmd) {
497		case NGM_EIFACE_SET:
498		{
499			struct ether_addr *eaddr;
500			struct ifaddr *ifa;
501			struct sockaddr_dl *sdl;
502
503			if (msg->header.arglen != sizeof(struct ether_addr)){
504				error = EINVAL;
505				break;
506			}
507			eaddr = (struct ether_addr *)(msg->data);
508			bcopy(eaddr, priv->arpcom.ac_enaddr, ETHER_ADDR_LEN);
509
510			/* And put it in the ifaddr list */
511			TAILQ_FOREACH(ifa, &(ifp->if_addrhead), ifa_link) {
512				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
513				if (sdl->sdl_type == IFT_ETHER) {
514					bcopy((IFP2AC(ifp))->ac_enaddr,
515						LLADDR(sdl), ifp->if_addrlen);
516					break;
517				}
518			}
519			break;
520		}
521
522		case NGM_EIFACE_GET_IFNAME:
523		{
524			struct ng_eiface_ifname *arg;
525
526			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
527			if (resp == NULL) {
528				error = ENOMEM;
529				break;
530			}
531			arg = (struct ng_eiface_ifname *)resp->data;
532			strlcpy(arg->ngif_name, ifp->if_xname,
533			    sizeof(arg->ngif_name));
534			break;
535		}
536
537		case NGM_EIFACE_GET_IFADDRS:
538		{
539			struct ifaddr  *ifa;
540			caddr_t		ptr;
541			int		buflen;
542
543#define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
544
545			/* Determine size of response and allocate it */
546			buflen = 0;
547			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
548			buflen += SA_SIZE(ifa->ifa_addr);
549			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
550			if (resp == NULL) {
551				error = ENOMEM;
552				break;
553			}
554			/* Add addresses */
555			ptr = resp->data;
556			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
557				const int       len = SA_SIZE(ifa->ifa_addr);
558
559				if (buflen < len) {
560					log(LOG_ERR, "%s: len changed?\n",
561					ifp->if_xname);
562					break;
563				}
564				bcopy(ifa->ifa_addr, ptr, len);
565				ptr += len;
566				buflen -= len;
567			}
568			break;
569#undef SA_SIZE
570		}
571
572		default:
573			error = EINVAL;
574			break;
575		} /* end of inner switch() */
576		break;
577	default:
578		error = EINVAL;
579		break;
580	}
581	NG_RESPOND_MSG(error, node, item, resp);
582	NG_FREE_MSG(msg);
583	return (error);
584}
585
586/*
587 * Recive data from a hook. Pass the packet to the ether_input routine.
588 */
589static int
590ng_eiface_rcvdata(hook_p hook, item_p item)
591{
592	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
593	struct ifnet   *const ifp = priv->ifp;
594	struct mbuf *m;
595
596	NGI_GET_M(item, m);
597        NG_FREE_ITEM(item);
598
599	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
600		NG_FREE_M(m);
601		return (ENETDOWN);
602	}
603
604	/* Note receiving interface */
605	m->m_pkthdr.rcvif = ifp;
606
607	/* Update interface stats */
608	ifp->if_ipackets++;
609
610	(*ifp->if_input)(ifp, m);
611
612	/* Done */
613	return (0);
614}
615
616/*
617 * the node.
618 */
619static int
620ng_eiface_rmnode(node_p node)
621{
622	priv_p		priv = NG_NODE_PRIVATE(node);
623	struct ifnet   *const ifp = priv->ifp;
624
625	ether_ifdetach(ifp);
626	ng_eiface_free_unit(priv->unit);
627	FREE(priv, M_NETGRAPH);
628	NG_NODE_SET_PRIVATE(node, NULL);
629	NG_NODE_UNREF(node);
630	return (0);
631}
632
633
634/*
635 * This is called once we've already connected a new hook to the other node.
636 * It gives us a chance to balk at the last minute.
637 */
638static int
639ng_eiface_connect(hook_p hook)
640{
641	/* be really amiable and just say "YUP that's OK by me! " */
642	return (0);
643}
644
645/*
646 * Hook disconnection
647 */
648static int
649ng_eiface_disconnect(hook_p hook)
650{
651	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
652
653	priv->ether = NULL;
654	return (0);
655}
656