ng_eiface.c revision 73006 
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 73006 2001-02-25 05:46:52Z julian $
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_types.h>
45#include <net/netisr.h>
46
47#include <netinet/in.h>
48#include <netinet/if_ether.h>
49
50#include <netgraph/ng_message.h>
51#include <netgraph/netgraph.h>
52#include <netgraph/ng_parse.h>
53#include <netgraph/ng_eiface.h>
54
55#include <net/bpf.h>
56#include <net/ethernet.h>
57#include <net/if_arp.h>
58
59
60/* Node private data */
61struct ng_eiface_private {
62	struct ifnet   *ifp;	/* This interface */
63	int	unit;		/* Interface unit number */
64	struct arpcom   arpcom;	/* per-interface network data */
65	node_p		node;	/* Our netgraph node */
66	hook_p		ether;	/* Hook for ethernet stream */
67};
68typedef struct ng_eiface_private *priv_p;
69
70/* Interface methods */
71static void     ng_eiface_init(void *xsc);
72static void     ng_eiface_start(struct ifnet *ifp);
73static int      ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
74#ifdef DEBUG
75static void     ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
76#endif
77
78/* Netgraph methods */
79static ng_constructor_t ng_eiface_constructor;
80static ng_rcvmsg_t ng_eiface_rcvmsg;
81static ng_shutdown_t ng_eiface_rmnode;
82static ng_newhook_t ng_eiface_newhook;
83static ng_rcvdata_t ng_eiface_rcvdata;
84static ng_connect_t ng_eiface_connect;
85static ng_disconnect_t ng_eiface_disconnect;
86
87/* Node type descriptor */
88static struct ng_type typestruct = {
89	NG_VERSION,
90	NG_EIFACE_NODE_TYPE,
91	NULL,
92	ng_eiface_constructor,
93	ng_eiface_rcvmsg,
94	ng_eiface_rmnode,
95	ng_eiface_newhook,
96	NULL,
97	ng_eiface_connect,
98	ng_eiface_rcvdata,
99	ng_eiface_disconnect,
100	ng_eiface_cmdlist
101};
102NETGRAPH_INIT(eiface, &typestruct);
103
104static char     ng_eiface_ifname[] = NG_EIFACE_EIFACE_NAME;
105
106/* We keep a bitmap indicating which unit numbers are free.
107   One means the unit number is free, zero means it's taken. */
108static int	*ng_eiface_units = NULL;
109static int	ng_eiface_units_len = 0;
110static int	ng_units_in_use = 0;
111
112#define UNITS_BITSPERWORD	(sizeof(*ng_eiface_units) * NBBY)
113
114
115/************************************************************************
116			HELPER STUFF
117 ************************************************************************/
118/*
119 * Find the first free unit number for a new interface.
120 * Increase the size of the unit bitmap as necessary.
121 */
122static __inline__ int
123ng_eiface_get_unit(int *unit)
124{
125	int index, bit;
126
127	for (index = 0; index < ng_eiface_units_len
128	    && ng_eiface_units[index] == 0; index++);
129	if (index == ng_eiface_units_len) {		/* extend array */
130		int i, *newarray, newlen;
131
132		newlen = (2 * ng_eiface_units_len) + 4;
133		MALLOC(newarray, int *, newlen * sizeof(*ng_eiface_units),
134		    M_NETGRAPH, M_NOWAIT);
135		if (newarray == NULL)
136			return (ENOMEM);
137		bcopy(ng_eiface_units, newarray,
138		    ng_eiface_units_len * sizeof(*ng_eiface_units));
139		for (i = ng_eiface_units_len; i < newlen; i++)
140			newarray[i] = ~0;
141		if (ng_eiface_units != NULL)
142			FREE(ng_eiface_units, M_NETGRAPH);
143		ng_eiface_units = newarray;
144		ng_eiface_units_len = newlen;
145	}
146	bit = ffs(ng_eiface_units[index]) - 1;
147	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
148	    ("%s: word=%d bit=%d", __FUNCTION__, ng_eiface_units[index], bit));
149	ng_eiface_units[index] &= ~(1 << bit);
150	*unit = (index * UNITS_BITSPERWORD) + bit;
151	ng_units_in_use++;
152	return (0);
153}
154
155/*
156 * Free a no longer needed unit number.
157 */
158static __inline__ void
159ng_eiface_free_unit(int unit)
160{
161	int index, bit;
162
163	index = unit / UNITS_BITSPERWORD;
164	bit = unit % UNITS_BITSPERWORD;
165	KASSERT(index < ng_eiface_units_len,
166	    ("%s: unit=%d len=%d", __FUNCTION__, unit, ng_eiface_units_len));
167	KASSERT((ng_eiface_units[index] & (1 << bit)) == 0,
168	    ("%s: unit=%d is free", __FUNCTION__, unit));
169	ng_eiface_units[index] |= (1 << bit);
170	/*
171	 * XXX We could think about reducing the size of ng_eiface_units[]
172	 * XXX here if the last portion is all ones
173	 * XXX At least free it if no more units.
174	 * Needed if we are to eventually be able to unload.
175	 */
176	ng_units_in_use--;
177	if (ng_units_in_use == 0) { /* XXX make SMP safe */
178		FREE(ng_eiface_units, M_NETGRAPH);
179		ng_eiface_units_len = 0;
180		ng_eiface_units = NULL;
181	}
182}
183
184/************************************************************************
185			INTERFACE STUFF
186 ************************************************************************/
187
188/*
189 * Process an ioctl for the virtual interface
190 */
191static int
192ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
193{
194	struct ifreq   *const ifr = (struct ifreq *)data;
195	int		s, error = 0;
196
197#ifdef DEBUG
198	ng_eiface_print_ioctl(ifp, command, data);
199#endif
200	s = splimp();
201	switch (command)
202	{
203	/* These two are mostly handled at a higher layer */
204	case SIOCSIFADDR:
205		error = ether_ioctl(ifp, command, data);
206		break;
207	case SIOCGIFADDR:
208		break;
209
210	/* Set flags */
211	case SIOCSIFFLAGS:
212		/*
213		 * If the interface is marked up and stopped, then
214		 * start it. If it is marked down and running,
215		 * then stop it.
216		 */
217		if (ifr->ifr_flags & IFF_UP) {
218			if (!(ifp->if_flags & IFF_RUNNING)) {
219				ifp->if_flags &= ~(IFF_OACTIVE);
220				ifp->if_flags |= IFF_RUNNING;
221			}
222		} else {
223			if (ifp->if_flags & IFF_RUNNING)
224				ifp->if_flags
225					&= ~(IFF_RUNNING | IFF_OACTIVE);
226		}
227		break;
228
229	/* Set the interface MTU */
230	case SIOCSIFMTU:
231		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX
232		|| ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
233			error = EINVAL;
234		else
235			ifp->if_mtu = ifr->ifr_mtu;
236		break;
237
238	/* Stuff that's not supported */
239	case SIOCADDMULTI:
240	case SIOCDELMULTI:
241		error = 0;
242		break;
243	case SIOCSIFPHYS:
244		error = EOPNOTSUPP;
245		break;
246
247	default:
248		error = EINVAL;
249		break;
250	}
251	(void)splx(s);
252	return (error);
253}
254
255static void
256ng_eiface_init(void *xsc)
257{
258	priv_p		sc = xsc;
259	struct ifnet   *ifp = sc->ifp;
260	int		s;
261
262	s = splimp();
263
264	ifp->if_flags |= IFF_RUNNING;
265	ifp->if_flags &= ~IFF_OACTIVE;
266
267	splx(s);
268}
269
270/*
271 * This routine is called to deliver a packet out the interface. We simply
272 * relay the packet to the ether hook, if it is connected.
273 */
274static void
275ng_eiface_start(struct ifnet *ifp)
276{
277	const priv_p priv = (priv_p) ifp->if_softc;
278	int		len, error = 0;
279	struct mbuf    *m;
280
281	/* Check interface flags */
282	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
283		return;
284
285	/* Don't do anything if output is active */
286	if (ifp->if_flags & IFF_OACTIVE)
287		return;
288
289	ifp->if_flags |= IFF_OACTIVE;
290
291	/*
292	 * Grab a packet to transmit.
293	 */
294	IF_DEQUEUE(&ifp->if_snd, m);
295
296	/* If there's nothing to send, return. */
297	if (m == NULL) {
298		ifp->if_flags &= ~IFF_OACTIVE;
299		return;
300	}
301
302	/* Berkeley packet filter
303	 * Pass packet to bpf if there is a listener.
304	 */
305	if (ifp->if_bpf)
306		bpf_mtap(ifp, m);
307
308	/* Copy length before the mbuf gets invalidated */
309	len = m->m_pkthdr.len;
310
311	/*
312	 * Send packet; if hook is not connected, mbuf will get
313	 * freed.
314	 */
315	NG_SEND_DATA_ONLY(error, priv->ether, m);
316
317	/* Update stats */
318	if (error == 0) {
319		ifp->if_obytes += len;
320		ifp->if_opackets++;
321	}
322	ifp->if_flags &= ~IFF_OACTIVE;
323	return;
324}
325
326#ifdef DEBUG
327/*
328 * Display an ioctl to the virtual interface
329 */
330
331static void
332ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data){
333	char		*str;
334
335	switch (command & IOC_DIRMASK)
336	{
337	case IOC_VOID:
338		str = "IO";
339		break;
340	case IOC_OUT:
341		str = "IOR";
342		break;
343	case IOC_IN:
344		str = "IOW";
345		break;
346	case IOC_INOUT:
347		str = "IORW";
348		break;
349	default:
350		str = "IO??";
351	}
352	log(LOG_DEBUG, "%s%d: %s('%c', %d, char[%d])\n",
353			ifp->if_name, ifp->if_unit,
354			str,
355			IOCGROUP(command),
356			command & 0xff,
357			IOCPARM_LEN(command));
358}
359#endif	/* DEBUG */
360
361/************************************************************************
362			NETGRAPH NODE STUFF
363 ************************************************************************/
364
365/*
366 * Constructor for a node
367 */
368static int
369ng_eiface_constructor(node_p node)
370{
371	struct ifnet   *ifp;
372	priv_p		priv;
373	int		error = 0;
374
375	/* Allocate node and interface private structures */
376	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
377	if (priv == NULL) {
378		return (ENOMEM);
379	}
380	bzero(priv, sizeof(*priv));
381
382	ifp = &(priv->arpcom.ac_if);
383
384	/* Link them together */
385	ifp->if_softc = priv;
386	priv->ifp = ifp;
387
388	/* Get an interface unit number */
389	if ((error = ng_eiface_get_unit(&priv->unit)) != 0) {
390		FREE(priv, M_NETGRAPH);
391		return (error);
392	}
393
394	/* Link together node and private info */
395	NG_NODE_SET_PRIVATE(node, priv);
396	priv->node = node;
397
398	/* Initialize interface structure */
399	ifp->if_name = ng_eiface_ifname;
400	ifp->if_unit = priv->unit;
401	ifp->if_init = ng_eiface_init;
402	ifp->if_output = ether_output;
403	ifp->if_start = ng_eiface_start;
404	ifp->if_ioctl = ng_eiface_ioctl;
405	ifp->if_watchdog = NULL;
406	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
407	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
408
409	/*
410	 * Give this node name * bzero(ifname, sizeof(ifname));
411	 * sprintf(ifname, "if%s%d", ifp->if_name, ifp->if_unit); (void)
412	 * ng_name_node(node, ifname);
413	 */
414
415	/* Attach the interface */
416	ether_ifattach(ifp, ETHER_BPF_SUPPORTED);
417
418	/* Done */
419	return (0);
420}
421
422/*
423 * Give our ok for a hook to be added
424 */
425static int
426ng_eiface_newhook(node_p node, hook_p hook, const char *name)
427{
428	priv_p		priv = NG_NODE_PRIVATE(node);
429
430	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
431		return (EPFNOSUPPORT);
432	if (priv->ether != NULL)
433		return (EISCONN);
434	priv->ether = hook;
435	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
436
437	return (0);
438}
439
440/*
441 * Receive a control message
442 */
443static int
444ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
445{
446	priv_p		priv = NG_NODE_PRIVATE(node);
447	struct ifnet   *const ifp = priv->ifp;
448	struct ng_mesg *resp = NULL;
449	int		error = 0;
450	struct ng_mesg *msg;
451
452	NGI_GET_MSG(item, msg);
453	switch		(msg->header.typecookie) {
454	case NGM_EIFACE_COOKIE:
455		switch (msg->header.cmd) {
456		case NGM_EIFACE_SET:
457		{
458			struct ng_eiface_par *eaddr;
459
460			if (msg->header.arglen != sizeof(struct ng_eiface_par)){
461				error = EINVAL;
462				break;
463			}
464			eaddr = (struct ng_eiface_par *)(msg->data);
465
466			priv->arpcom.ac_enaddr[0] = eaddr->oct0;
467			priv->arpcom.ac_enaddr[1] = eaddr->oct1;
468			priv->arpcom.ac_enaddr[2] = eaddr->oct2;
469			priv->arpcom.ac_enaddr[3] = eaddr->oct3;
470			priv->arpcom.ac_enaddr[4] = eaddr->oct4;
471			priv->arpcom.ac_enaddr[5] = eaddr->oct5;
472
473			break;
474		}
475
476		case NGM_EIFACE_GET_IFNAME:
477		{
478			struct ng_eiface_ifname *arg;
479
480			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
481			if (resp == NULL) {
482				error = ENOMEM;
483				break;
484			}
485			arg = (struct ng_eiface_ifname *)resp->data;
486			sprintf(arg->ngif_name,
487				"%s%d", ifp->if_name, ifp->if_unit);
488			break;
489		}
490
491		case NGM_EIFACE_GET_IFADDRS:
492		{
493			struct ifaddr  *ifa;
494			caddr_t		ptr;
495			int		buflen;
496
497#define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
498
499			/* Determine size of response and allocate it */
500			buflen = 0;
501			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
502			buflen += SA_SIZE(ifa->ifa_addr);
503			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
504			if (resp == NULL) {
505				error = ENOMEM;
506				break;
507			}
508			/* Add addresses */
509			ptr = resp->data;
510			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
511				const int       len = SA_SIZE(ifa->ifa_addr);
512
513				if (buflen < len) {
514					log(LOG_ERR, "%s%d: len changed?\n",
515					ifp->if_name, ifp->if_unit);
516					break;
517				}
518				bcopy(ifa->ifa_addr, ptr, len);
519				ptr += len;
520				buflen -= len;
521			}
522			break;
523#undef SA_SIZE
524		}
525
526		default:
527			error = EINVAL;
528			break;
529		} /* end of inner switch() */
530		break;
531	default:
532		error = EINVAL;
533		break;
534	}
535	NG_RESPOND_MSG(error, node, item, resp);
536	NG_FREE_MSG(msg);
537	return (error);
538}
539
540/*
541 * Recive data from a hook. Pass the packet to the ether_input routine.
542 */
543static int
544ng_eiface_rcvdata(hook_p hook, item_p item)
545{
546	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
547	struct ifnet   *const ifp = priv->ifp;
548	int		s, error = 0;
549	struct ether_header *eh;
550	u_short		ether_type;
551	struct mbuf *m;
552
553	NGI_GET_M(item, m);
554	/* Meta-data ends its life here... */
555        NG_FREE_ITEM(item);
556
557	if (m == NULL)
558	{
559		printf("ng_eiface: mbuf is null.\n");
560		return (EINVAL);
561	}
562	if (!(ifp->if_flags & IFF_UP)) {
563		return (ENETDOWN);
564	}
565
566	/* Note receiving interface */
567	m->m_pkthdr.rcvif = ifp;
568
569	/* Update interface stats */
570	ifp->if_ipackets++;
571
572	eh = mtod(m, struct ether_header *);
573	ether_type = ntohs(eh->ether_type);
574
575	s = splimp();
576	m->m_pkthdr.len -= sizeof(*eh);
577	m->m_len -= sizeof(*eh);
578	if (m->m_len) {
579		m->m_data += sizeof(*eh);
580	} else {
581		if (ether_type == ETHERTYPE_ARP) {
582			m->m_len = m->m_next->m_len;
583			m->m_data = m->m_next->m_data;
584		}
585	}
586	splx(s);
587
588	ether_input(ifp, eh, m);
589
590	/* Done */
591	return (error);
592}
593
594/*
595 * the node.
596 */
597static int
598ng_eiface_rmnode(node_p node)
599{
600	priv_p		priv = NG_NODE_PRIVATE(node);
601	struct ifnet   *const ifp = priv->ifp;
602
603	ether_ifdetach(ifp, ETHER_BPF_SUPPORTED);
604	ng_eiface_free_unit(priv->unit);
605	FREE(priv, M_NETGRAPH);
606	NG_NODE_SET_PRIVATE(node, NULL);
607	NG_NODE_UNREF(node);
608	return (0);
609}
610
611
612/*
613 * This is called once we've already connected a new hook to the other node.
614 * It gives us a chance to balk at the last minute.
615 */
616static int
617ng_eiface_connect(hook_p hook)
618{
619	/* be really amiable and just say "YUP that's OK by me! " */
620	return (0);
621}
622
623/*
624 * Hook disconnection
625 */
626static int
627ng_eiface_disconnect(hook_p hook)
628{
629	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
630
631	priv->ether = NULL;
632	return (0);
633}
634