ng_eiface.c revision 184205 
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 184205 2008-10-23 15:53:51Z des $
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/malloc.h>
36#include <sys/mbuf.h>
37#include <sys/errno.h>
38#include <sys/sockio.h>
39#include <sys/socket.h>
40#include <sys/syslog.h>
41#include <sys/vimage.h>
42
43#include <net/if.h>
44#include <net/if_types.h>
45#include <net/netisr.h>
46
47#include <netgraph/ng_message.h>
48#include <netgraph/netgraph.h>
49#include <netgraph/ng_parse.h>
50#include <netgraph/ng_eiface.h>
51
52#include <net/bpf.h>
53#include <net/ethernet.h>
54#include <net/if_arp.h>
55
56static const struct ng_cmdlist ng_eiface_cmdlist[] = {
57	{
58	  NGM_EIFACE_COOKIE,
59	  NGM_EIFACE_GET_IFNAME,
60	  "getifname",
61	  NULL,
62	  &ng_parse_string_type
63	},
64	{
65	  NGM_EIFACE_COOKIE,
66	  NGM_EIFACE_SET,
67	  "set",
68	  &ng_parse_enaddr_type,
69	  NULL
70	},
71	{ 0 }
72};
73
74/* Node private data */
75struct ng_eiface_private {
76	struct ifnet	*ifp;		/* per-interface network data */
77	int		unit;		/* Interface unit number */
78	node_p		node;		/* Our netgraph node */
79	hook_p		ether;		/* Hook for ethernet stream */
80};
81typedef struct ng_eiface_private *priv_p;
82
83/* Interface methods */
84static void	ng_eiface_init(void *xsc);
85static void	ng_eiface_start(struct ifnet *ifp);
86static int	ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
87#ifdef DEBUG
88static void	ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
89#endif
90
91/* Netgraph methods */
92static int		ng_eiface_mod_event(module_t, int, void *);
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_disconnect_t	ng_eiface_disconnect;
99
100/* Node type descriptor */
101static struct ng_type typestruct = {
102	.version =	NG_ABI_VERSION,
103	.name =		NG_EIFACE_NODE_TYPE,
104	.mod_event =	ng_eiface_mod_event,
105	.constructor =	ng_eiface_constructor,
106	.rcvmsg =	ng_eiface_rcvmsg,
107	.shutdown =	ng_eiface_rmnode,
108	.newhook =	ng_eiface_newhook,
109	.rcvdata =	ng_eiface_rcvdata,
110	.disconnect =	ng_eiface_disconnect,
111	.cmdlist =	ng_eiface_cmdlist
112};
113NETGRAPH_INIT(eiface, &typestruct);
114
115static struct unrhdr	*ng_eiface_unit;
116
117/************************************************************************
118			INTERFACE STUFF
119 ************************************************************************/
120
121/*
122 * Process an ioctl for the virtual interface
123 */
124static int
125ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
126{
127	struct ifreq *const ifr = (struct ifreq *)data;
128	int s, error = 0;
129
130#ifdef DEBUG
131	ng_eiface_print_ioctl(ifp, command, data);
132#endif
133	s = splimp();
134	switch (command) {
135
136	/* These two are mostly handled at a higher layer */
137	case SIOCSIFADDR:
138		error = ether_ioctl(ifp, command, data);
139		break;
140	case SIOCGIFADDR:
141		break;
142
143	/* Set flags */
144	case SIOCSIFFLAGS:
145		/*
146		 * If the interface is marked up and stopped, then start it.
147		 * If it is marked down and running, then stop it.
148		 */
149		if (ifp->if_flags & IFF_UP) {
150			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
151				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
152				ifp->if_drv_flags |= IFF_DRV_RUNNING;
153			}
154		} else {
155			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
156				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
157				    IFF_DRV_OACTIVE);
158		}
159		break;
160
161	/* Set the interface MTU */
162	case SIOCSIFMTU:
163		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX ||
164		    ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
165			error = EINVAL;
166		else
167			ifp->if_mtu = ifr->ifr_mtu;
168		break;
169
170	/* Stuff that's not supported */
171	case SIOCADDMULTI:
172	case SIOCDELMULTI:
173		error = 0;
174		break;
175	case SIOCSIFPHYS:
176		error = EOPNOTSUPP;
177		break;
178
179	default:
180		error = EINVAL;
181		break;
182	}
183	splx(s);
184	return (error);
185}
186
187static void
188ng_eiface_init(void *xsc)
189{
190	priv_p sc = xsc;
191	struct ifnet *ifp = sc->ifp;
192	int s;
193
194	s = splimp();
195
196	ifp->if_drv_flags |= IFF_DRV_RUNNING;
197	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
198
199	splx(s);
200}
201
202/*
203 * We simply relay the packet to the "ether" hook, if it is connected.
204 * We have been through the netgraph locking and are guaranteed to
205 * be the only code running in this node at this time.
206 */
207static void
208ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
209{
210	struct ifnet *ifp = arg1;
211	const priv_p priv = (priv_p)ifp->if_softc;
212	int error = 0;
213	struct mbuf *m;
214
215	/* Check interface flags */
216
217	if (!((ifp->if_flags & IFF_UP) &&
218	    (ifp->if_drv_flags & IFF_DRV_RUNNING)))
219		return;
220
221	for (;;) {
222		/*
223		 * Grab a packet to transmit.
224		 */
225		IF_DEQUEUE(&ifp->if_snd, m);
226
227		/* If there's nothing to send, break. */
228		if (m == NULL)
229			break;
230
231		/*
232		 * Berkeley packet filter.
233		 * Pass packet to bpf if there is a listener.
234		 * XXX is this safe? locking?
235		 */
236		BPF_MTAP(ifp, m);
237
238		if (ifp->if_flags & IFF_MONITOR) {
239			ifp->if_ipackets++;
240			m_freem(m);
241			continue;
242		}
243
244		/*
245		 * Send packet; if hook is not connected, mbuf will get
246		 * freed.
247		 */
248		NG_SEND_DATA_ONLY(error, priv->ether, m);
249
250		/* Update stats */
251		if (error == 0)
252			ifp->if_opackets++;
253		else
254			ifp->if_oerrors++;
255	}
256
257	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
258
259	return;
260}
261
262/*
263 * This routine is called to deliver a packet out the interface.
264 * We simply queue the netgraph version to be called when netgraph locking
265 * allows it to happen.
266 * Until we know what the rest of the networking code is doing for
267 * locking, we don't know how we will interact with it.
268 * Take comfort from the fact that the ifnet struct is part of our
269 * private info and can't go away while we are queued.
270 * [Though we don't know it is still there now....]
271 * it is possible we don't gain anything from this because
272 * we would like to get the mbuf and queue it as data
273 * somehow, but we can't and if we did would we solve anything?
274 */
275static void
276ng_eiface_start(struct ifnet *ifp)
277{
278
279	const priv_p priv = (priv_p)ifp->if_softc;
280
281	/* Don't do anything if output is active */
282	if (ifp->if_drv_flags & IFF_DRV_OACTIVE)
283		return;
284
285	ifp->if_drv_flags |= IFF_DRV_OACTIVE;
286
287	if (ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0) != 0)
288		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
289}
290
291#ifdef DEBUG
292/*
293 * Display an ioctl to the virtual interface
294 */
295
296static void
297ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
298{
299	char *str;
300
301	switch (command & IOC_DIRMASK) {
302	case IOC_VOID:
303		str = "IO";
304		break;
305	case IOC_OUT:
306		str = "IOR";
307		break;
308	case IOC_IN:
309		str = "IOW";
310		break;
311	case IOC_INOUT:
312		str = "IORW";
313		break;
314	default:
315		str = "IO??";
316	}
317	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
318	    ifp->if_xname,
319	    str,
320	    IOCGROUP(command),
321	    command & 0xff,
322	    IOCPARM_LEN(command));
323}
324#endif /* DEBUG */
325
326/************************************************************************
327			NETGRAPH NODE STUFF
328 ************************************************************************/
329
330/*
331 * Constructor for a node
332 */
333static int
334ng_eiface_constructor(node_p node)
335{
336	INIT_VNET_NETGRAPH(curvnet);
337	struct ifnet *ifp;
338	priv_p priv;
339	u_char eaddr[6] = {0,0,0,0,0,0};
340
341	/* Allocate node and interface private structures */
342	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
343	if (priv == NULL)
344		return (ENOMEM);
345
346	ifp = priv->ifp = if_alloc(IFT_ETHER);
347	if (ifp == NULL) {
348		free(priv, M_NETGRAPH);
349		return (ENOSPC);
350	}
351
352	/* Link them together */
353	ifp->if_softc = priv;
354
355	/* Get an interface unit number */
356	priv->unit = alloc_unr(V_ng_eiface_unit);
357
358	/* Link together node and private info */
359	NG_NODE_SET_PRIVATE(node, priv);
360	priv->node = node;
361
362	/* Initialize interface structure */
363	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
364	ifp->if_init = ng_eiface_init;
365	ifp->if_output = ether_output;
366	ifp->if_start = ng_eiface_start;
367	ifp->if_ioctl = ng_eiface_ioctl;
368	ifp->if_watchdog = NULL;
369	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
370	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
371
372#if 0
373	/* Give this node name */
374	bzero(ifname, sizeof(ifname));
375	sprintf(ifname, "if%s", ifp->if_xname);
376	(void)ng_name_node(node, ifname);
377#endif
378
379	/* Attach the interface */
380	ether_ifattach(ifp, eaddr);
381
382	/* Done */
383	return (0);
384}
385
386/*
387 * Give our ok for a hook to be added
388 */
389static int
390ng_eiface_newhook(node_p node, hook_p hook, const char *name)
391{
392	priv_p priv = NG_NODE_PRIVATE(node);
393	struct ifnet *ifp = priv->ifp;
394
395	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
396		return (EPFNOSUPPORT);
397	if (priv->ether != NULL)
398		return (EISCONN);
399	priv->ether = hook;
400	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
401
402	if_link_state_change(ifp, LINK_STATE_UP);
403
404	return (0);
405}
406
407/*
408 * Receive a control message
409 */
410static int
411ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
412{
413	const priv_p priv = NG_NODE_PRIVATE(node);
414	struct ifnet *const ifp = priv->ifp;
415	struct ng_mesg *resp = NULL;
416	int error = 0;
417	struct ng_mesg *msg;
418
419	NGI_GET_MSG(item, msg);
420	switch (msg->header.typecookie) {
421	case NGM_EIFACE_COOKIE:
422		switch (msg->header.cmd) {
423
424		case NGM_EIFACE_SET:
425		    {
426			if (msg->header.arglen != ETHER_ADDR_LEN) {
427				error = EINVAL;
428				break;
429			}
430			error = if_setlladdr(priv->ifp,
431			    (u_char *)msg->data, ETHER_ADDR_LEN);
432			break;
433		    }
434
435		case NGM_EIFACE_GET_IFNAME:
436			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
437			if (resp == NULL) {
438				error = ENOMEM;
439				break;
440			}
441			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
442			break;
443
444		case NGM_EIFACE_GET_IFADDRS:
445		    {
446			struct ifaddr *ifa;
447			caddr_t ptr;
448			int buflen;
449
450#define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
451
452			/* Determine size of response and allocate it */
453			buflen = 0;
454			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
455				buflen += SA_SIZE(ifa->ifa_addr);
456			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
457			if (resp == NULL) {
458				error = ENOMEM;
459				break;
460			}
461
462			/* Add addresses */
463			ptr = resp->data;
464			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
465				const int len = SA_SIZE(ifa->ifa_addr);
466
467				if (buflen < len) {
468					log(LOG_ERR, "%s: len changed?\n",
469					    ifp->if_xname);
470					break;
471				}
472				bcopy(ifa->ifa_addr, ptr, len);
473				ptr += len;
474				buflen -= len;
475			}
476			break;
477#undef SA_SIZE
478		    }
479
480		default:
481			error = EINVAL;
482			break;
483		} /* end of inner switch() */
484		break;
485	case NGM_FLOW_COOKIE:
486		switch (msg->header.cmd) {
487		case NGM_LINK_IS_UP:
488			if_link_state_change(ifp, LINK_STATE_UP);
489			break;
490		case NGM_LINK_IS_DOWN:
491			if_link_state_change(ifp, LINK_STATE_DOWN);
492			break;
493		default:
494			break;
495		}
496		break;
497	default:
498		error = EINVAL;
499		break;
500	}
501	NG_RESPOND_MSG(error, node, item, resp);
502	NG_FREE_MSG(msg);
503	return (error);
504}
505
506/*
507 * Receive data from a hook. Pass the packet to the ether_input routine.
508 */
509static int
510ng_eiface_rcvdata(hook_p hook, item_p item)
511{
512	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
513	struct ifnet *const ifp = priv->ifp;
514	struct mbuf *m;
515
516	NGI_GET_M(item, m);
517	NG_FREE_ITEM(item);
518
519	if (!((ifp->if_flags & IFF_UP) &&
520	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
521		NG_FREE_M(m);
522		return (ENETDOWN);
523	}
524
525	if (m->m_len < ETHER_HDR_LEN) {
526		m = m_pullup(m, ETHER_HDR_LEN);
527		if (m == NULL)
528			return (EINVAL);
529	}
530
531	/* Note receiving interface */
532	m->m_pkthdr.rcvif = ifp;
533
534	/* Update interface stats */
535	ifp->if_ipackets++;
536
537	(*ifp->if_input)(ifp, m);
538
539	/* Done */
540	return (0);
541}
542
543/*
544 * Shutdown processing.
545 */
546static int
547ng_eiface_rmnode(node_p node)
548{
549	INIT_VNET_NETGRAPH(curvnet);
550	const priv_p priv = NG_NODE_PRIVATE(node);
551	struct ifnet *const ifp = priv->ifp;
552
553	/*
554	 * the ifnet may be in a different vnet than the netgraph node,
555	 * hence we have to change the current vnet context here.
556	 */
557	CURVNET_SET_QUIET(ifp->if_vnet);
558	ether_ifdetach(ifp);
559	if_free(ifp);
560	CURVNET_RESTORE();
561	free_unr(V_ng_eiface_unit, priv->unit);
562	free(priv, M_NETGRAPH);
563	NG_NODE_SET_PRIVATE(node, NULL);
564	NG_NODE_UNREF(node);
565	return (0);
566}
567
568/*
569 * Hook disconnection
570 */
571static int
572ng_eiface_disconnect(hook_p hook)
573{
574	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
575
576	priv->ether = NULL;
577	return (0);
578}
579
580/*
581 * Handle loading and unloading for this node type.
582 */
583static int
584ng_eiface_mod_event(module_t mod, int event, void *data)
585{
586	int error = 0;
587
588	switch (event) {
589	case MOD_LOAD:
590		V_ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
591		break;
592	case MOD_UNLOAD:
593		delete_unrhdr(V_ng_eiface_unit);
594		break;
595	default:
596		error = EOPNOTSUPP;
597		break;
598	}
599	return (error);
600}
601