ng_eiface.c revision 141140 
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 141140 2005-02-02 13:27:03Z ru $
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/lock.h>
36#include <sys/malloc.h>
37#include <sys/mbuf.h>
38#include <sys/mutex.h>
39#include <sys/errno.h>
40#include <sys/sockio.h>
41#include <sys/socket.h>
42#include <sys/syslog.h>
43
44#include <net/if.h>
45#include <net/if_dl.h>
46#include <net/if_types.h>
47#include <net/netisr.h>
48
49#include <netinet/in.h>
50#include <netinet/if_ether.h>
51
52#include <netgraph/ng_message.h>
53#include <netgraph/netgraph.h>
54#include <netgraph/ng_parse.h>
55#include <netgraph/ng_eiface.h>
56
57#include <net/bpf.h>
58#include <net/ethernet.h>
59#include <net/if_arp.h>
60
61static const struct ng_cmdlist ng_eiface_cmdlist[] = {
62	{
63	  NGM_EIFACE_COOKIE,
64	  NGM_EIFACE_SET,
65	  "set",
66	  &ng_parse_enaddr_type,
67	  NULL
68	},
69	{ 0 }
70};
71
72/* Node private data */
73struct ng_eiface_private {
74	struct arpcom	arpcom;		/* per-interface network data */
75	struct ifnet	*ifp;		/* This interface */
76	int		unit;		/* Interface unit number */
77	node_p		node;		/* Our netgraph node */
78	hook_p		ether;		/* Hook for ethernet stream */
79};
80typedef struct ng_eiface_private *priv_p;
81
82/* Interface methods */
83static void	ng_eiface_init(void *xsc);
84static void	ng_eiface_start(struct ifnet *ifp);
85static int	ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
86#ifdef DEBUG
87static void	ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
88#endif
89
90/* Netgraph methods */
91static ng_constructor_t	ng_eiface_constructor;
92static ng_rcvmsg_t	ng_eiface_rcvmsg;
93static ng_shutdown_t	ng_eiface_rmnode;
94static ng_newhook_t	ng_eiface_newhook;
95static ng_rcvdata_t	ng_eiface_rcvdata;
96static ng_connect_t	ng_eiface_connect;
97static ng_disconnect_t	ng_eiface_disconnect;
98
99/* Node type descriptor */
100static struct ng_type typestruct = {
101	.version =	NG_ABI_VERSION,
102	.name =		NG_EIFACE_NODE_TYPE,
103	.constructor =	ng_eiface_constructor,
104	.rcvmsg =	ng_eiface_rcvmsg,
105	.shutdown =	ng_eiface_rmnode,
106	.newhook =	ng_eiface_newhook,
107	.connect =	ng_eiface_connect,
108	.rcvdata =	ng_eiface_rcvdata,
109	.disconnect =	ng_eiface_disconnect,
110	.cmdlist =	ng_eiface_cmdlist
111};
112NETGRAPH_INIT(eiface, &typestruct);
113
114/* We keep a bitmap indicating which unit numbers are free.
115   One means the unit number is free, zero means it's taken. */
116static int	*ng_eiface_units = NULL;
117static int	ng_eiface_units_len = 0;
118static int	ng_units_in_use = 0;
119
120#define UNITS_BITSPERWORD	(sizeof(*ng_eiface_units) * NBBY)
121
122static struct mtx	ng_eiface_mtx;
123MTX_SYSINIT(ng_eiface, &ng_eiface_mtx, "ng_eiface", MTX_DEF);
124
125/************************************************************************
126			HELPER STUFF
127 ************************************************************************/
128/*
129 * Find the first free unit number for a new interface.
130 * Increase the size of the unit bitmap as necessary.
131 */
132static __inline int
133ng_eiface_get_unit(int *unit)
134{
135	int index, bit;
136
137	mtx_lock(&ng_eiface_mtx);
138	for (index = 0; index < ng_eiface_units_len
139	    && ng_eiface_units[index] == 0; index++);
140	if (index == ng_eiface_units_len) {		/* extend array */
141		int i, *newarray, newlen;
142
143		newlen = (2 * ng_eiface_units_len) + 4;
144		MALLOC(newarray, int *, newlen * sizeof(*ng_eiface_units),
145		    M_NETGRAPH, M_NOWAIT);
146		if (newarray == NULL) {
147			mtx_unlock(&ng_eiface_mtx);
148			return (ENOMEM);
149		}
150		bcopy(ng_eiface_units, newarray,
151		    ng_eiface_units_len * sizeof(*ng_eiface_units));
152		for (i = ng_eiface_units_len; i < newlen; i++)
153			newarray[i] = ~0;
154		if (ng_eiface_units != NULL)
155			FREE(ng_eiface_units, M_NETGRAPH);
156		ng_eiface_units = newarray;
157		ng_eiface_units_len = newlen;
158	}
159	bit = ffs(ng_eiface_units[index]) - 1;
160	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
161	    ("%s: word=%d bit=%d", __func__, ng_eiface_units[index], bit));
162	ng_eiface_units[index] &= ~(1 << bit);
163	*unit = (index * UNITS_BITSPERWORD) + bit;
164	ng_units_in_use++;
165	mtx_unlock(&ng_eiface_mtx);
166	return (0);
167}
168
169/*
170 * Free a no longer needed unit number.
171 */
172static __inline void
173ng_eiface_free_unit(int unit)
174{
175	int index, bit;
176
177	index = unit / UNITS_BITSPERWORD;
178	bit = unit % UNITS_BITSPERWORD;
179	mtx_lock(&ng_eiface_mtx);
180	KASSERT(index < ng_eiface_units_len,
181	    ("%s: unit=%d len=%d", __func__, unit, ng_eiface_units_len));
182	KASSERT((ng_eiface_units[index] & (1 << bit)) == 0,
183	    ("%s: unit=%d is free", __func__, unit));
184	ng_eiface_units[index] |= (1 << bit);
185	/*
186	 * XXX We could think about reducing the size of ng_eiface_units[]
187	 * XXX here if the last portion is all ones
188	 * XXX At least free it if no more units.
189	 * Needed if we are to eventually be able to unload.
190	 */
191	ng_units_in_use--;
192	if (ng_units_in_use == 0) { /* XXX make SMP safe */
193		FREE(ng_eiface_units, M_NETGRAPH);
194		ng_eiface_units_len = 0;
195		ng_eiface_units = NULL;
196	}
197	mtx_unlock(&ng_eiface_mtx);
198}
199
200/************************************************************************
201			INTERFACE STUFF
202 ************************************************************************/
203
204/*
205 * Process an ioctl for the virtual interface
206 */
207static int
208ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
209{
210	struct ifreq *const ifr = (struct ifreq *)data;
211	int s, error = 0;
212
213#ifdef DEBUG
214	ng_eiface_print_ioctl(ifp, command, data);
215#endif
216	s = splimp();
217	switch (command) {
218
219	/* These two are mostly handled at a higher layer */
220	case SIOCSIFADDR:
221		error = ether_ioctl(ifp, command, data);
222		break;
223	case SIOCGIFADDR:
224		break;
225
226	/* Set flags */
227	case SIOCSIFFLAGS:
228		/*
229		 * If the interface is marked up and stopped, then start it.
230		 * If it is marked down and running, then stop it.
231		 */
232		if (ifr->ifr_flags & IFF_UP) {
233			if (!(ifp->if_flags & IFF_RUNNING)) {
234				ifp->if_flags &= ~(IFF_OACTIVE);
235				ifp->if_flags |= IFF_RUNNING;
236			}
237		} else {
238			if (ifp->if_flags & IFF_RUNNING)
239				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
240		}
241		break;
242
243	/* Set the interface MTU */
244	case SIOCSIFMTU:
245		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX ||
246		    ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
247			error = EINVAL;
248		else
249			ifp->if_mtu = ifr->ifr_mtu;
250		break;
251
252	/* Stuff that's not supported */
253	case SIOCADDMULTI:
254	case SIOCDELMULTI:
255		error = 0;
256		break;
257	case SIOCSIFPHYS:
258		error = EOPNOTSUPP;
259		break;
260
261	default:
262		error = EINVAL;
263		break;
264	}
265	splx(s);
266	return (error);
267}
268
269static void
270ng_eiface_init(void *xsc)
271{
272	priv_p sc = xsc;
273	struct ifnet *ifp = sc->ifp;
274	int s;
275
276	s = splimp();
277
278	ifp->if_flags |= IFF_RUNNING;
279	ifp->if_flags &= ~IFF_OACTIVE;
280
281	splx(s);
282}
283
284/*
285 * We simply relay the packet to the ether hook, if it is connected.
286 * We have been throughthe netgraph locking an are guaranteed to
287 * be the only code running in this node at this time.
288 */
289static void
290ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
291{
292	struct ifnet *ifp = arg1;
293	const priv_p priv = (priv_p)ifp->if_softc;
294	int len, error = 0;
295	struct mbuf *m;
296
297	/* Check interface flags */
298	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
299		return;
300
301	/* Don't do anything if output is active */
302	if (ifp->if_flags & IFF_OACTIVE)
303		return;
304
305	ifp->if_flags |= IFF_OACTIVE;
306
307	/*
308	 * Grab a packet to transmit.
309	 */
310	IF_DEQUEUE(&ifp->if_snd, m);
311
312	/* If there's nothing to send, return. */
313	if (m == NULL) {
314		ifp->if_flags &= ~IFF_OACTIVE;
315		return;
316	}
317
318	/*
319	 * Berkeley packet filter.
320	 * Pass packet to bpf if there is a listener.
321	 * XXX is this safe? locking?
322	 */
323	BPF_MTAP(ifp, m);
324
325	/* Copy length before the mbuf gets invalidated */
326	len = m->m_pkthdr.len;
327
328	/*
329	 * Send packet; if hook is not connected, mbuf will get
330	 * freed.
331	 */
332	NG_SEND_DATA_ONLY(error, priv->ether, m);
333
334	/* Update stats */
335	if (error == 0) {
336		ifp->if_obytes += len;
337		ifp->if_opackets++;
338	}
339
340	ifp->if_flags &= ~IFF_OACTIVE;
341
342	return;
343}
344
345/*
346 * This routine is called to deliver a packet out the interface.
347 * We simply queue the netgraph version to be called when netgraph locking
348 * allows it to happen.
349 * Until we know what the rest of the networking code is doing for
350 * locking, we don't know how we will interact with it.
351 * Take comfort from the fact that the ifnet struct is part of our
352 * private info and can't go away while we are queued.
353 * [Though we don't know it is still there now....]
354 * it is possible we don't gain anything from this because
355 * we would like to get the mbuf and queue it as data
356 * somehow, but we can't and if we did would we solve anything?
357 */
358static void
359ng_eiface_start(struct ifnet *ifp)
360{
361
362	const priv_p priv = (priv_p)ifp->if_softc;
363
364	ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0);
365}
366
367#ifdef DEBUG
368/*
369 * Display an ioctl to the virtual interface
370 */
371
372static void
373ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
374{
375	char *str;
376
377	switch (command & IOC_DIRMASK) {
378	case IOC_VOID:
379		str = "IO";
380		break;
381	case IOC_OUT:
382		str = "IOR";
383		break;
384	case IOC_IN:
385		str = "IOW";
386		break;
387	case IOC_INOUT:
388		str = "IORW";
389		break;
390	default:
391		str = "IO??";
392	}
393	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
394	    ifp->if_xname,
395	    str,
396	    IOCGROUP(command),
397	    command & 0xff,
398	    IOCPARM_LEN(command));
399}
400#endif /* DEBUG */
401
402/************************************************************************
403			NETGRAPH NODE STUFF
404 ************************************************************************/
405
406/*
407 * Constructor for a node
408 */
409static int
410ng_eiface_constructor(node_p node)
411{
412	struct ifnet *ifp;
413	priv_p priv;
414	int error = 0;
415
416	/* Allocate node and interface private structures */
417	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
418	if (priv == NULL)
419		return (ENOMEM);
420	bzero(priv, sizeof(*priv));
421
422	ifp = &(priv->arpcom.ac_if);
423
424	/* Link them together */
425	ifp->if_softc = priv;
426	priv->ifp = ifp;
427
428	/* Get an interface unit number */
429	if ((error = ng_eiface_get_unit(&priv->unit)) != 0) {
430		FREE(priv, M_NETGRAPH);
431		return (error);
432	}
433
434	/* Link together node and private info */
435	NG_NODE_SET_PRIVATE(node, priv);
436	priv->node = node;
437
438	/* Initialize interface structure */
439	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
440	ifp->if_init = ng_eiface_init;
441	ifp->if_output = ether_output;
442	ifp->if_start = ng_eiface_start;
443	ifp->if_ioctl = ng_eiface_ioctl;
444	ifp->if_watchdog = NULL;
445	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
446	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
447
448#if 0
449	/* Give this node name */
450	bzero(ifname, sizeof(ifname));
451	sprintf(ifname, "if%s", ifp->if_xname);
452	(void)ng_name_node(node, ifname);
453#endif
454
455	/* Attach the interface */
456	ether_ifattach(ifp, priv->arpcom.ac_enaddr);
457
458	/* Done */
459	return (0);
460}
461
462/*
463 * Give our ok for a hook to be added
464 */
465static int
466ng_eiface_newhook(node_p node, hook_p hook, const char *name)
467{
468	priv_p priv = NG_NODE_PRIVATE(node);
469
470	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
471		return (EPFNOSUPPORT);
472	if (priv->ether != NULL)
473		return (EISCONN);
474	priv->ether = hook;
475	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
476
477	return (0);
478}
479
480/*
481 * Receive a control message
482 */
483static int
484ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
485{
486	const priv_p priv = NG_NODE_PRIVATE(node);
487	struct ifnet *const ifp = priv->ifp;
488	struct ng_mesg *resp = NULL;
489	int error = 0;
490	struct ng_mesg *msg;
491
492	NGI_GET_MSG(item, msg);
493	switch (msg->header.typecookie) {
494	case NGM_EIFACE_COOKIE:
495		switch (msg->header.cmd) {
496
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
555			/* Add addresses */
556			ptr = resp->data;
557			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
558				const int len = SA_SIZE(ifa->ifa_addr);
559
560				if (buflen < len) {
561					log(LOG_ERR, "%s: len changed?\n",
562					    ifp->if_xname);
563					break;
564				}
565				bcopy(ifa->ifa_addr, ptr, len);
566				ptr += len;
567				buflen -= len;
568			}
569			break;
570#undef SA_SIZE
571		    }
572
573		default:
574			error = EINVAL;
575			break;
576		} /* end of inner switch() */
577		break;
578	case NGM_FLOW_COOKIE:
579		switch (msg->header.cmd) {
580		case NGM_LINK_IS_UP:
581			ifp->if_flags |= IFF_RUNNING;
582			break;
583		case NGM_LINK_IS_DOWN:
584			ifp->if_flags &= ~IFF_RUNNING;
585			break;
586		default:
587			break;
588		}
589		break;
590	default:
591		error = EINVAL;
592		break;
593	}
594	NG_RESPOND_MSG(error, node, item, resp);
595	NG_FREE_MSG(msg);
596	return (error);
597}
598
599/*
600 * Receive data from a hook. Pass the packet to the ether_input routine.
601 */
602static int
603ng_eiface_rcvdata(hook_p hook, item_p item)
604{
605	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
606	struct ifnet *const ifp = priv->ifp;
607	struct mbuf *m;
608
609	NGI_GET_M(item, m);
610	NG_FREE_ITEM(item);
611
612	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) !=
613	    (IFF_UP | IFF_RUNNING)) {
614		NG_FREE_M(m);
615		return (ENETDOWN);
616	}
617
618	/* Note receiving interface */
619	m->m_pkthdr.rcvif = ifp;
620
621	/* Update interface stats */
622	ifp->if_ipackets++;
623
624	(*ifp->if_input)(ifp, m);
625
626	/* Done */
627	return (0);
628}
629
630/*
631 * Shutdown processing.
632 */
633static int
634ng_eiface_rmnode(node_p node)
635{
636	const priv_p priv = NG_NODE_PRIVATE(node);
637	struct ifnet *const ifp = priv->ifp;
638
639	ether_ifdetach(ifp);
640	ng_eiface_free_unit(priv->unit);
641	FREE(priv, M_NETGRAPH);
642	NG_NODE_SET_PRIVATE(node, NULL);
643	NG_NODE_UNREF(node);
644	return (0);
645}
646
647
648/*
649 * This is called once we've already connected a new hook to the other node.
650 * It gives us a chance to balk at the last minute.
651 */
652static int
653ng_eiface_connect(hook_p hook)
654{
655	/* be really amiable and just say "YUP that's OK by me! " */
656	return (0);
657}
658
659/*
660 * Hook disconnection
661 */
662static int
663ng_eiface_disconnect(hook_p hook)
664{
665	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
666
667	priv->ether = NULL;
668	return (0);
669}
670