ng_eiface.c revision 128376 
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 128376 2004-04-18 01:15:32Z luigi $
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_cmdlist ng_eiface_cmdlist[] = {
61	{
62	  NGM_EIFACE_COOKIE,
63	  NGM_EIFACE_SET,
64	  "set",
65	  &ng_parse_enaddr_type,
66	  NULL
67	},
68	{ 0 }
69};
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	NG_ABI_VERSION,
102	NG_EIFACE_NODE_TYPE,
103	NULL,
104	ng_eiface_constructor,
105	ng_eiface_rcvmsg,
106	ng_eiface_rmnode,
107	ng_eiface_newhook,
108	NULL,
109	ng_eiface_connect,
110	ng_eiface_rcvdata,
111	ng_eiface_disconnect,
112	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
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	for (index = 0; index < ng_eiface_units_len
138	    && ng_eiface_units[index] == 0; index++);
139	if (index == ng_eiface_units_len) {		/* extend array */
140		int i, *newarray, newlen;
141
142		newlen = (2 * ng_eiface_units_len) + 4;
143		MALLOC(newarray, int *, newlen * sizeof(*ng_eiface_units),
144		    M_NETGRAPH, M_NOWAIT);
145		if (newarray == NULL)
146			return (ENOMEM);
147		bcopy(ng_eiface_units, newarray,
148		    ng_eiface_units_len * sizeof(*ng_eiface_units));
149		for (i = ng_eiface_units_len; i < newlen; i++)
150			newarray[i] = ~0;
151		if (ng_eiface_units != NULL)
152			FREE(ng_eiface_units, M_NETGRAPH);
153		ng_eiface_units = newarray;
154		ng_eiface_units_len = newlen;
155	}
156	bit = ffs(ng_eiface_units[index]) - 1;
157	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
158	    ("%s: word=%d bit=%d", __func__, ng_eiface_units[index], bit));
159	ng_eiface_units[index] &= ~(1 << bit);
160	*unit = (index * UNITS_BITSPERWORD) + bit;
161	ng_units_in_use++;
162	return (0);
163}
164
165/*
166 * Free a no longer needed unit number.
167 */
168static __inline__ void
169ng_eiface_free_unit(int unit)
170{
171	int index, bit;
172
173	index = unit / UNITS_BITSPERWORD;
174	bit = unit % UNITS_BITSPERWORD;
175	KASSERT(index < ng_eiface_units_len,
176	    ("%s: unit=%d len=%d", __func__, unit, ng_eiface_units_len));
177	KASSERT((ng_eiface_units[index] & (1 << bit)) == 0,
178	    ("%s: unit=%d is free", __func__, unit));
179	ng_eiface_units[index] |= (1 << bit);
180	/*
181	 * XXX We could think about reducing the size of ng_eiface_units[]
182	 * XXX here if the last portion is all ones
183	 * XXX At least free it if no more units.
184	 * Needed if we are to eventually be able to unload.
185	 */
186	ng_units_in_use--;
187	if (ng_units_in_use == 0) { /* XXX make SMP safe */
188		FREE(ng_eiface_units, M_NETGRAPH);
189		ng_eiface_units_len = 0;
190		ng_eiface_units = NULL;
191	}
192}
193
194/************************************************************************
195			INTERFACE STUFF
196 ************************************************************************/
197
198/*
199 * Process an ioctl for the virtual interface
200 */
201static int
202ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
203{
204	struct ifreq   *const ifr = (struct ifreq *)data;
205	int		s, error = 0;
206
207#ifdef DEBUG
208	ng_eiface_print_ioctl(ifp, command, data);
209#endif
210	s = splimp();
211	switch (command)
212	{
213	/* These two are mostly handled at a higher layer */
214	case SIOCSIFADDR:
215		error = ether_ioctl(ifp, command, data);
216		break;
217	case SIOCGIFADDR:
218		break;
219
220	/* Set flags */
221	case SIOCSIFFLAGS:
222		/*
223		 * If the interface is marked up and stopped, then
224		 * start it. If it is marked down and running,
225		 * then stop it.
226		 */
227		if (ifr->ifr_flags & IFF_UP) {
228			if (!(ifp->if_flags & IFF_RUNNING)) {
229				ifp->if_flags &= ~(IFF_OACTIVE);
230				ifp->if_flags |= IFF_RUNNING;
231			}
232		} else {
233			if (ifp->if_flags & IFF_RUNNING)
234				ifp->if_flags
235					&= ~(IFF_RUNNING | IFF_OACTIVE);
236		}
237		break;
238
239	/* Set the interface MTU */
240	case SIOCSIFMTU:
241		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX
242		|| ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
243			error = EINVAL;
244		else
245			ifp->if_mtu = ifr->ifr_mtu;
246		break;
247
248	/* Stuff that's not supported */
249	case SIOCADDMULTI:
250	case SIOCDELMULTI:
251		error = 0;
252		break;
253	case SIOCSIFPHYS:
254		error = EOPNOTSUPP;
255		break;
256
257	default:
258		error = EINVAL;
259		break;
260	}
261	(void)splx(s);
262	return (error);
263}
264
265static void
266ng_eiface_init(void *xsc)
267{
268	priv_p		sc = xsc;
269	struct ifnet   *ifp = sc->ifp;
270	int		s;
271
272	s = splimp();
273
274	ifp->if_flags |= IFF_RUNNING;
275	ifp->if_flags &= ~IFF_OACTIVE;
276
277	splx(s);
278}
279
280/*
281 * We simply relay the packet to the ether hook, if it is connected.
282 * We have been throughthe netgraph locking an are guaranteed to
283 * be the only code running in this node at this time.
284 */
285static void
286ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
287{
288	struct ifnet *ifp = arg1;
289	const priv_p priv = (priv_p) ifp->if_softc;
290	int		len, error = 0;
291	struct mbuf    *m;
292
293	/* Check interface flags */
294	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
295		return;
296
297	/* Don't do anything if output is active */
298	if (ifp->if_flags & IFF_OACTIVE)
299		return;
300
301	ifp->if_flags |= IFF_OACTIVE;
302
303	/*
304	 * Grab a packet to transmit.
305	 */
306	IF_DEQUEUE(&ifp->if_snd, m);
307
308	/* If there's nothing to send, return. */
309	if (m == NULL) {
310		ifp->if_flags &= ~IFF_OACTIVE;
311		return;
312	}
313
314	/* Berkeley packet filter
315	 * Pass packet to bpf if there is a listener.
316	 * XXX is this safe? locking?
317	 */
318	BPF_MTAP(ifp, m);
319
320	/* Copy length before the mbuf gets invalidated */
321	len = m->m_pkthdr.len;
322
323	/*
324	 * Send packet; if hook is not connected, mbuf will get
325	 * freed.
326	 */
327	NG_SEND_DATA_ONLY(error, priv->ether, m);
328
329	/* Update stats */
330	if (error == 0) {
331		ifp->if_obytes += len;
332		ifp->if_opackets++;
333	}
334	ifp->if_flags &= ~IFF_OACTIVE;
335	return;
336}
337
338/*
339 * This routine is called to deliver a packet out the interface.
340 * We simply queue the netgraph version to be called when netgraph locking
341 * allows it to happen.
342 * Until we know what the rest of the networking code is doing for
343 * locking, we don't know how we will interact with it.
344 * Take comfort from the fact that the ifnet struct is part of our
345 * private info and can't go away while we are queued.
346 * [Though we don't know it is still there now....]
347 * it is possible we don't gain anything from this because
348 * we would like to get the mbuf and queue it as data
349 * somehow, but we can't and if we did would we solve anything?
350 */
351static void
352ng_eiface_start(struct ifnet *ifp)
353{
354
355	const priv_p priv = (priv_p) ifp->if_softc;
356
357	ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0);
358}
359
360#ifdef DEBUG
361/*
362 * Display an ioctl to the virtual interface
363 */
364
365static void
366ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data){
367	char		*str;
368
369	switch (command & IOC_DIRMASK)
370	{
371	case IOC_VOID:
372		str = "IO";
373		break;
374	case IOC_OUT:
375		str = "IOR";
376		break;
377	case IOC_IN:
378		str = "IOW";
379		break;
380	case IOC_INOUT:
381		str = "IORW";
382		break;
383	default:
384		str = "IO??";
385	}
386	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
387			ifp->if_xname,
388			str,
389			IOCGROUP(command),
390			command & 0xff,
391			IOCPARM_LEN(command));
392}
393#endif	/* DEBUG */
394
395/************************************************************************
396			NETGRAPH NODE STUFF
397 ************************************************************************/
398
399/*
400 * Constructor for a node
401 */
402static int
403ng_eiface_constructor(node_p node)
404{
405	struct ifnet   *ifp;
406	priv_p		priv;
407	int		error = 0;
408
409	/* Allocate node and interface private structures */
410	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
411	if (priv == NULL) {
412		return (ENOMEM);
413	}
414	bzero(priv, sizeof(*priv));
415
416	ifp = &(priv->arpcom.ac_if);
417
418	/* Link them together */
419	ifp->if_softc = priv;
420	priv->ifp = ifp;
421
422	/* Get an interface unit number */
423	if ((error = ng_eiface_get_unit(&priv->unit)) != 0) {
424		FREE(priv, M_NETGRAPH);
425		return (error);
426	}
427
428	/* Link together node and private info */
429	NG_NODE_SET_PRIVATE(node, priv);
430	priv->node = node;
431
432	/* Initialize interface structure */
433	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
434	ifp->if_init = ng_eiface_init;
435	ifp->if_output = ether_output;
436	ifp->if_start = ng_eiface_start;
437	ifp->if_ioctl = ng_eiface_ioctl;
438	ifp->if_watchdog = NULL;
439	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
440	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
441
442	/*
443	 * Give this node name * bzero(ifname, sizeof(ifname));
444	 * sprintf(ifname, "if%s", ifp->if_xname); (void)
445	 * ng_name_node(node, ifname);
446	 */
447
448	/* Attach the interface */
449	ether_ifattach(ifp, priv->arpcom.ac_enaddr);
450
451	/* Done */
452	return (0);
453}
454
455/*
456 * Give our ok for a hook to be added
457 */
458static int
459ng_eiface_newhook(node_p node, hook_p hook, const char *name)
460{
461	priv_p		priv = NG_NODE_PRIVATE(node);
462
463	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
464		return (EPFNOSUPPORT);
465	if (priv->ether != NULL)
466		return (EISCONN);
467	priv->ether = hook;
468	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
469
470	return (0);
471}
472
473/*
474 * Receive a control message
475 */
476static int
477ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
478{
479	priv_p		priv = NG_NODE_PRIVATE(node);
480	struct ifnet   *const ifp = priv->ifp;
481	struct ng_mesg *resp = NULL;
482	int		error = 0;
483	struct ng_mesg *msg;
484
485	NGI_GET_MSG(item, msg);
486	switch		(msg->header.typecookie) {
487	case NGM_EIFACE_COOKIE:
488		switch (msg->header.cmd) {
489		case NGM_EIFACE_SET:
490		{
491			struct ether_addr *eaddr;
492			struct ifaddr *ifa;
493			struct sockaddr_dl *sdl;
494
495			if (msg->header.arglen != sizeof(struct ether_addr)){
496				error = EINVAL;
497				break;
498			}
499			eaddr = (struct ether_addr *)(msg->data);
500			bcopy(eaddr, priv->arpcom.ac_enaddr, ETHER_ADDR_LEN);
501
502			/* And put it in the ifaddr list */
503			TAILQ_FOREACH(ifa, &(ifp->if_addrhead), ifa_link) {
504				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
505				if (sdl->sdl_type == IFT_ETHER) {
506					bcopy((IFP2AC(ifp))->ac_enaddr,
507						LLADDR(sdl), ifp->if_addrlen);
508					break;
509				}
510			}
511			break;
512		}
513
514		case NGM_EIFACE_GET_IFNAME:
515		{
516			struct ng_eiface_ifname *arg;
517
518			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
519			if (resp == NULL) {
520				error = ENOMEM;
521				break;
522			}
523			arg = (struct ng_eiface_ifname *)resp->data;
524			strlcpy(arg->ngif_name, ifp->if_xname,
525			    sizeof(arg->ngif_name));
526			break;
527		}
528
529		case NGM_EIFACE_GET_IFADDRS:
530		{
531			struct ifaddr  *ifa;
532			caddr_t		ptr;
533			int		buflen;
534
535#define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
536
537			/* Determine size of response and allocate it */
538			buflen = 0;
539			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
540			buflen += SA_SIZE(ifa->ifa_addr);
541			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
542			if (resp == NULL) {
543				error = ENOMEM;
544				break;
545			}
546			/* Add addresses */
547			ptr = resp->data;
548			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
549				const int       len = SA_SIZE(ifa->ifa_addr);
550
551				if (buflen < len) {
552					log(LOG_ERR, "%s: len changed?\n",
553					ifp->if_xname);
554					break;
555				}
556				bcopy(ifa->ifa_addr, ptr, len);
557				ptr += len;
558				buflen -= len;
559			}
560			break;
561#undef SA_SIZE
562		}
563
564		default:
565			error = EINVAL;
566			break;
567		} /* end of inner switch() */
568		break;
569	default:
570		error = EINVAL;
571		break;
572	}
573	NG_RESPOND_MSG(error, node, item, resp);
574	NG_FREE_MSG(msg);
575	return (error);
576}
577
578/*
579 * Recive data from a hook. Pass the packet to the ether_input routine.
580 */
581static int
582ng_eiface_rcvdata(hook_p hook, item_p item)
583{
584	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
585	struct ifnet   *const ifp = priv->ifp;
586	struct mbuf *m;
587
588	NGI_GET_M(item, m);
589	/* Meta-data ends its life here... */
590        NG_FREE_ITEM(item);
591
592	if (m == NULL)
593	{
594		printf("ng_eiface: mbuf is null.\n");
595		return (EINVAL);
596	}
597	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
598		NG_FREE_M(m);
599		return (ENETDOWN);
600	}
601
602	/* Note receiving interface */
603	m->m_pkthdr.rcvif = ifp;
604
605	/* Update interface stats */
606	ifp->if_ipackets++;
607
608	(*ifp->if_input)(ifp, m);
609
610	/* Done */
611	return (0);
612}
613
614/*
615 * the node.
616 */
617static int
618ng_eiface_rmnode(node_p node)
619{
620	priv_p		priv = NG_NODE_PRIVATE(node);
621	struct ifnet   *const ifp = priv->ifp;
622
623	ether_ifdetach(ifp);
624	ng_eiface_free_unit(priv->unit);
625	FREE(priv, M_NETGRAPH);
626	NG_NODE_SET_PRIVATE(node, NULL);
627	NG_NODE_UNREF(node);
628	return (0);
629}
630
631
632/*
633 * This is called once we've already connected a new hook to the other node.
634 * It gives us a chance to balk at the last minute.
635 */
636static int
637ng_eiface_connect(hook_p hook)
638{
639	/* be really amiable and just say "YUP that's OK by me! " */
640	return (0);
641}
642
643/*
644 * Hook disconnection
645 */
646static int
647ng_eiface_disconnect(hook_p hook)
648{
649	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
650
651	priv->ether = NULL;
652	return (0);
653}
654