ng_eiface.c revision 121816 
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 121816 2003-10-31 18:32:15Z brooks $
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/malloc.h>
37#include <sys/mbuf.h>
38#include <sys/errno.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_dl.h>
45#include <net/if_types.h>
46#include <net/netisr.h>
47
48#include <netinet/in.h>
49#include <netinet/if_ether.h>
50
51#include <netgraph/ng_message.h>
52#include <netgraph/netgraph.h>
53#include <netgraph/ng_parse.h>
54#include <netgraph/ng_eiface.h>
55
56#include <net/bpf.h>
57#include <net/ethernet.h>
58#include <net/if_arp.h>
59
60static const struct ng_parse_struct_field ng_eiface_par_fields[]
61	= NG_EIFACE_PAR_FIELDS;
62
63static const struct ng_parse_type ng_eiface_par_type = {
64	&ng_parse_struct_type,
65	&ng_eiface_par_fields
66};
67
68static const struct ng_cmdlist ng_eiface_cmdlist[] = {
69	{
70	  NGM_EIFACE_COOKIE,
71	  NGM_EIFACE_SET,
72	  "set",
73	  &ng_eiface_par_type,
74	  NULL
75	},
76	{ 0 }
77};
78
79
80/* Node private data */
81struct ng_eiface_private {
82	struct ifnet   *ifp;	/* This interface */
83	int	unit;		/* Interface unit number */
84	struct arpcom   arpcom;	/* per-interface network data */
85	node_p		node;	/* Our netgraph node */
86	hook_p		ether;	/* Hook for ethernet stream */
87};
88typedef struct ng_eiface_private *priv_p;
89
90/* Interface methods */
91static void     ng_eiface_init(void *xsc);
92static void     ng_eiface_start(struct ifnet *ifp);
93static int      ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
94#ifdef DEBUG
95static void     ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
96#endif
97
98/* Netgraph methods */
99static ng_constructor_t ng_eiface_constructor;
100static ng_rcvmsg_t ng_eiface_rcvmsg;
101static ng_shutdown_t ng_eiface_rmnode;
102static ng_newhook_t ng_eiface_newhook;
103static ng_rcvdata_t ng_eiface_rcvdata;
104static ng_connect_t ng_eiface_connect;
105static ng_disconnect_t ng_eiface_disconnect;
106
107/* Node type descriptor */
108static struct ng_type typestruct = {
109	NG_ABI_VERSION,
110	NG_EIFACE_NODE_TYPE,
111	NULL,
112	ng_eiface_constructor,
113	ng_eiface_rcvmsg,
114	ng_eiface_rmnode,
115	ng_eiface_newhook,
116	NULL,
117	ng_eiface_connect,
118	ng_eiface_rcvdata,
119	ng_eiface_disconnect,
120	ng_eiface_cmdlist
121};
122NETGRAPH_INIT(eiface, &typestruct);
123
124/* We keep a bitmap indicating which unit numbers are free.
125   One means the unit number is free, zero means it's taken. */
126static int	*ng_eiface_units = NULL;
127static int	ng_eiface_units_len = 0;
128static int	ng_units_in_use = 0;
129
130#define UNITS_BITSPERWORD	(sizeof(*ng_eiface_units) * NBBY)
131
132
133/************************************************************************
134			HELPER STUFF
135 ************************************************************************/
136/*
137 * Find the first free unit number for a new interface.
138 * Increase the size of the unit bitmap as necessary.
139 */
140static __inline__ int
141ng_eiface_get_unit(int *unit)
142{
143	int index, bit;
144
145	for (index = 0; index < ng_eiface_units_len
146	    && ng_eiface_units[index] == 0; index++);
147	if (index == ng_eiface_units_len) {		/* extend array */
148		int i, *newarray, newlen;
149
150		newlen = (2 * ng_eiface_units_len) + 4;
151		MALLOC(newarray, int *, newlen * sizeof(*ng_eiface_units),
152		    M_NETGRAPH, M_NOWAIT);
153		if (newarray == NULL)
154			return (ENOMEM);
155		bcopy(ng_eiface_units, newarray,
156		    ng_eiface_units_len * sizeof(*ng_eiface_units));
157		for (i = ng_eiface_units_len; i < newlen; i++)
158			newarray[i] = ~0;
159		if (ng_eiface_units != NULL)
160			FREE(ng_eiface_units, M_NETGRAPH);
161		ng_eiface_units = newarray;
162		ng_eiface_units_len = newlen;
163	}
164	bit = ffs(ng_eiface_units[index]) - 1;
165	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
166	    ("%s: word=%d bit=%d", __func__, ng_eiface_units[index], bit));
167	ng_eiface_units[index] &= ~(1 << bit);
168	*unit = (index * UNITS_BITSPERWORD) + bit;
169	ng_units_in_use++;
170	return (0);
171}
172
173/*
174 * Free a no longer needed unit number.
175 */
176static __inline__ void
177ng_eiface_free_unit(int unit)
178{
179	int index, bit;
180
181	index = unit / UNITS_BITSPERWORD;
182	bit = unit % UNITS_BITSPERWORD;
183	KASSERT(index < ng_eiface_units_len,
184	    ("%s: unit=%d len=%d", __func__, unit, ng_eiface_units_len));
185	KASSERT((ng_eiface_units[index] & (1 << bit)) == 0,
186	    ("%s: unit=%d is free", __func__, unit));
187	ng_eiface_units[index] |= (1 << bit);
188	/*
189	 * XXX We could think about reducing the size of ng_eiface_units[]
190	 * XXX here if the last portion is all ones
191	 * XXX At least free it if no more units.
192	 * Needed if we are to eventually be able to unload.
193	 */
194	ng_units_in_use--;
195	if (ng_units_in_use == 0) { /* XXX make SMP safe */
196		FREE(ng_eiface_units, M_NETGRAPH);
197		ng_eiface_units_len = 0;
198		ng_eiface_units = NULL;
199	}
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 ng_eiface_par *eaddr;
500			struct ifaddr *ifa;
501			struct sockaddr_dl *sdl;
502
503			if (msg->header.arglen != sizeof(struct ng_eiface_par)){
504				error = EINVAL;
505				break;
506			}
507			eaddr = (struct ng_eiface_par *)(msg->data);
508
509			priv->arpcom.ac_enaddr[0] = eaddr->oct0;
510			priv->arpcom.ac_enaddr[1] = eaddr->oct1;
511			priv->arpcom.ac_enaddr[2] = eaddr->oct2;
512			priv->arpcom.ac_enaddr[3] = eaddr->oct3;
513			priv->arpcom.ac_enaddr[4] = eaddr->oct4;
514			priv->arpcom.ac_enaddr[5] = eaddr->oct5;
515
516			/* And put it in the ifaddr list */
517#define IFP2AC(IFP) ((struct arpcom *)IFP)
518			TAILQ_FOREACH(ifa, &(ifp->if_addrhead), ifa_link) {
519				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
520				if (sdl->sdl_type == IFT_ETHER) {
521					bcopy((IFP2AC(ifp))->ac_enaddr,
522						LLADDR(sdl), ifp->if_addrlen);
523					break;
524				}
525			}
526			break;
527		}
528
529		case NGM_EIFACE_GET_IFNAME:
530		{
531			struct ng_eiface_ifname *arg;
532
533			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
534			if (resp == NULL) {
535				error = ENOMEM;
536				break;
537			}
538			arg = (struct ng_eiface_ifname *)resp->data;
539			strlcpy(arg->ngif_name, ifp->if_xname,
540			    sizeof(arg->ngif_name));
541			break;
542		}
543
544		case NGM_EIFACE_GET_IFADDRS:
545		{
546			struct ifaddr  *ifa;
547			caddr_t		ptr;
548			int		buflen;
549
550#define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
551
552			/* Determine size of response and allocate it */
553			buflen = 0;
554			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
555			buflen += SA_SIZE(ifa->ifa_addr);
556			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
557			if (resp == NULL) {
558				error = ENOMEM;
559				break;
560			}
561			/* Add addresses */
562			ptr = resp->data;
563			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
564				const int       len = SA_SIZE(ifa->ifa_addr);
565
566				if (buflen < len) {
567					log(LOG_ERR, "%s: len changed?\n",
568					ifp->if_xname);
569					break;
570				}
571				bcopy(ifa->ifa_addr, ptr, len);
572				ptr += len;
573				buflen -= len;
574			}
575			break;
576#undef SA_SIZE
577		}
578
579		default:
580			error = EINVAL;
581			break;
582		} /* end of inner switch() */
583		break;
584	default:
585		error = EINVAL;
586		break;
587	}
588	NG_RESPOND_MSG(error, node, item, resp);
589	NG_FREE_MSG(msg);
590	return (error);
591}
592
593/*
594 * Recive data from a hook. Pass the packet to the ether_input routine.
595 */
596static int
597ng_eiface_rcvdata(hook_p hook, item_p item)
598{
599	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
600	struct ifnet   *const ifp = priv->ifp;
601	struct mbuf *m;
602
603	NGI_GET_M(item, m);
604	/* Meta-data ends its life here... */
605        NG_FREE_ITEM(item);
606
607	if (m == NULL)
608	{
609		printf("ng_eiface: mbuf is null.\n");
610		return (EINVAL);
611	}
612	if (!(ifp->if_flags & IFF_UP)) {
613		return (ENETDOWN);
614	}
615
616	/* Note receiving interface */
617	m->m_pkthdr.rcvif = ifp;
618
619	/* Update interface stats */
620	ifp->if_ipackets++;
621
622	(*ifp->if_input)(ifp, m);
623
624	/* Done */
625	return (0);
626}
627
628/*
629 * the node.
630 */
631static int
632ng_eiface_rmnode(node_p node)
633{
634	priv_p		priv = NG_NODE_PRIVATE(node);
635	struct ifnet   *const ifp = priv->ifp;
636
637	ether_ifdetach(ifp);
638	ng_eiface_free_unit(priv->unit);
639	FREE(priv, M_NETGRAPH);
640	NG_NODE_SET_PRIVATE(node, NULL);
641	NG_NODE_UNREF(node);
642	return (0);
643}
644
645
646/*
647 * This is called once we've already connected a new hook to the other node.
648 * It gives us a chance to balk at the last minute.
649 */
650static int
651ng_eiface_connect(hook_p hook)
652{
653	/* be really amiable and just say "YUP that's OK by me! " */
654	return (0);
655}
656
657/*
658 * Hook disconnection
659 */
660static int
661ng_eiface_disconnect(hook_p hook)
662{
663	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
664
665	priv->ether = NULL;
666	return (0);
667}
668