ng_eiface.c revision 147256 
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 147256 2005-06-10 16:49:24Z brooks $
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
42#include <net/if.h>
43#include <net/if_dl.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 (ifr->ifr_flags & IFF_UP) {
150			if (!(ifp->if_flags & IFF_RUNNING)) {
151				ifp->if_flags &= ~(IFF_OACTIVE);
152				ifp->if_flags |= IFF_RUNNING;
153			}
154		} else {
155			if (ifp->if_flags & IFF_RUNNING)
156				ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
157		}
158		break;
159
160	/* Set the interface MTU */
161	case SIOCSIFMTU:
162		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX ||
163		    ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
164			error = EINVAL;
165		else
166			ifp->if_mtu = ifr->ifr_mtu;
167		break;
168
169	/* Stuff that's not supported */
170	case SIOCADDMULTI:
171	case SIOCDELMULTI:
172		error = 0;
173		break;
174	case SIOCSIFPHYS:
175		error = EOPNOTSUPP;
176		break;
177
178	default:
179		error = EINVAL;
180		break;
181	}
182	splx(s);
183	return (error);
184}
185
186static void
187ng_eiface_init(void *xsc)
188{
189	priv_p sc = xsc;
190	struct ifnet *ifp = sc->ifp;
191	int s;
192
193	s = splimp();
194
195	ifp->if_flags |= IFF_RUNNING;
196	ifp->if_flags &= ~IFF_OACTIVE;
197
198	splx(s);
199}
200
201/*
202 * We simply relay the packet to the "ether" hook, if it is connected.
203 * We have been through the netgraph locking and are guaranteed to
204 * be the only code running in this node at this time.
205 */
206static void
207ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
208{
209	struct ifnet *ifp = arg1;
210	const priv_p priv = (priv_p)ifp->if_softc;
211	int len, error = 0;
212	struct mbuf *m;
213
214	/* Check interface flags */
215	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
216		return;
217
218	/* Don't do anything if output is active */
219	if (ifp->if_flags & IFF_OACTIVE)
220		return;
221
222	ifp->if_flags |= IFF_OACTIVE;
223
224	/*
225	 * Grab a packet to transmit.
226	 */
227	IF_DEQUEUE(&ifp->if_snd, m);
228
229	/* If there's nothing to send, return. */
230	if (m == NULL) {
231		ifp->if_flags &= ~IFF_OACTIVE;
232		return;
233	}
234
235	/*
236	 * Berkeley packet filter.
237	 * Pass packet to bpf if there is a listener.
238	 * XXX is this safe? locking?
239	 */
240	BPF_MTAP(ifp, m);
241
242	/* Copy length before the mbuf gets invalidated */
243	len = m->m_pkthdr.len;
244
245	/*
246	 * Send packet; if hook is not connected, mbuf will get
247	 * freed.
248	 */
249	NG_SEND_DATA_ONLY(error, priv->ether, m);
250
251	/* Update stats */
252	if (error == 0) {
253		ifp->if_obytes += len;
254		ifp->if_opackets++;
255	}
256
257	ifp->if_flags &= ~IFF_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	ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0);
282}
283
284#ifdef DEBUG
285/*
286 * Display an ioctl to the virtual interface
287 */
288
289static void
290ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
291{
292	char *str;
293
294	switch (command & IOC_DIRMASK) {
295	case IOC_VOID:
296		str = "IO";
297		break;
298	case IOC_OUT:
299		str = "IOR";
300		break;
301	case IOC_IN:
302		str = "IOW";
303		break;
304	case IOC_INOUT:
305		str = "IORW";
306		break;
307	default:
308		str = "IO??";
309	}
310	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
311	    ifp->if_xname,
312	    str,
313	    IOCGROUP(command),
314	    command & 0xff,
315	    IOCPARM_LEN(command));
316}
317#endif /* DEBUG */
318
319/************************************************************************
320			NETGRAPH NODE STUFF
321 ************************************************************************/
322
323/*
324 * Constructor for a node
325 */
326static int
327ng_eiface_constructor(node_p node)
328{
329	struct ifnet *ifp;
330	priv_p priv;
331	u_char eaddr[6] = {0,0,0,0,0,0};
332
333	/* Allocate node and interface private structures */
334	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
335	if (priv == NULL)
336		return (ENOMEM);
337
338	ifp = priv->ifp = if_alloc(IFT_ETHER);
339	if (ifp == NULL) {
340		free(priv, M_NETGRAPH);
341		return (ENOSPC);
342	}
343
344	/* Link them together */
345	ifp->if_softc = priv;
346
347	/* Get an interface unit number */
348	priv->unit = alloc_unr(ng_eiface_unit);
349
350	/* Link together node and private info */
351	NG_NODE_SET_PRIVATE(node, priv);
352	priv->node = node;
353
354	/* Initialize interface structure */
355	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
356	ifp->if_init = ng_eiface_init;
357	ifp->if_output = ether_output;
358	ifp->if_start = ng_eiface_start;
359	ifp->if_ioctl = ng_eiface_ioctl;
360	ifp->if_watchdog = NULL;
361	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
362	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
363
364#if 0
365	/* Give this node name */
366	bzero(ifname, sizeof(ifname));
367	sprintf(ifname, "if%s", ifp->if_xname);
368	(void)ng_name_node(node, ifname);
369#endif
370
371	/* Attach the interface */
372	ether_ifattach(ifp, eaddr);
373
374	/* Done */
375	return (0);
376}
377
378/*
379 * Give our ok for a hook to be added
380 */
381static int
382ng_eiface_newhook(node_p node, hook_p hook, const char *name)
383{
384	priv_p priv = NG_NODE_PRIVATE(node);
385	struct ifnet *ifp = priv->ifp;
386
387	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
388		return (EPFNOSUPPORT);
389	if (priv->ether != NULL)
390		return (EISCONN);
391	priv->ether = hook;
392	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
393
394	if_link_state_change(ifp, LINK_STATE_UP);
395
396	return (0);
397}
398
399/*
400 * Receive a control message
401 */
402static int
403ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
404{
405	const priv_p priv = NG_NODE_PRIVATE(node);
406	struct ifnet *const ifp = priv->ifp;
407	struct ng_mesg *resp = NULL;
408	int error = 0;
409	struct ng_mesg *msg;
410
411	NGI_GET_MSG(item, msg);
412	switch (msg->header.typecookie) {
413	case NGM_EIFACE_COOKIE:
414		switch (msg->header.cmd) {
415
416		case NGM_EIFACE_SET:
417		    {
418			struct ether_addr *eaddr;
419			struct ifaddr *ifa;
420			struct sockaddr_dl *sdl;
421
422			if (msg->header.arglen != sizeof(struct ether_addr)) {
423				error = EINVAL;
424				break;
425			}
426			eaddr = (struct ether_addr *)(msg->data);
427			bcopy(eaddr, IFP2ENADDR(priv->ifp),
428			    ETHER_ADDR_LEN);
429
430			/* And put it in the ifaddr list */
431			TAILQ_FOREACH(ifa, &(ifp->if_addrhead), ifa_link) {
432				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
433				if (sdl->sdl_type == IFT_ETHER) {
434					bcopy(IFP2ENADDR(ifp),
435						LLADDR(sdl), ifp->if_addrlen);
436					break;
437				}
438			}
439			break;
440		    }
441
442		case NGM_EIFACE_GET_IFNAME:
443			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
444			if (resp == NULL) {
445				error = ENOMEM;
446				break;
447			}
448			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
449			break;
450
451		case NGM_EIFACE_GET_IFADDRS:
452		    {
453			struct ifaddr *ifa;
454			caddr_t ptr;
455			int buflen;
456
457#define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
458
459			/* Determine size of response and allocate it */
460			buflen = 0;
461			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
462				buflen += SA_SIZE(ifa->ifa_addr);
463			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
464			if (resp == NULL) {
465				error = ENOMEM;
466				break;
467			}
468
469			/* Add addresses */
470			ptr = resp->data;
471			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
472				const int len = SA_SIZE(ifa->ifa_addr);
473
474				if (buflen < len) {
475					log(LOG_ERR, "%s: len changed?\n",
476					    ifp->if_xname);
477					break;
478				}
479				bcopy(ifa->ifa_addr, ptr, len);
480				ptr += len;
481				buflen -= len;
482			}
483			break;
484#undef SA_SIZE
485		    }
486
487		default:
488			error = EINVAL;
489			break;
490		} /* end of inner switch() */
491		break;
492	case NGM_FLOW_COOKIE:
493		switch (msg->header.cmd) {
494		case NGM_LINK_IS_UP:
495			if_link_state_change(ifp, LINK_STATE_UP);
496			break;
497		case NGM_LINK_IS_DOWN:
498			if_link_state_change(ifp, LINK_STATE_DOWN);
499			break;
500		default:
501			break;
502		}
503		break;
504	default:
505		error = EINVAL;
506		break;
507	}
508	NG_RESPOND_MSG(error, node, item, resp);
509	NG_FREE_MSG(msg);
510	return (error);
511}
512
513/*
514 * Receive data from a hook. Pass the packet to the ether_input routine.
515 */
516static int
517ng_eiface_rcvdata(hook_p hook, item_p item)
518{
519	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
520	struct ifnet *const ifp = priv->ifp;
521	struct mbuf *m;
522
523	NGI_GET_M(item, m);
524	NG_FREE_ITEM(item);
525
526	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) !=
527	    (IFF_UP | IFF_RUNNING)) {
528		NG_FREE_M(m);
529		return (ENETDOWN);
530	}
531
532	if (m->m_len < ETHER_HDR_LEN) {
533		m = m_pullup(m, ETHER_HDR_LEN);
534		if (m == NULL)
535			return (EINVAL);
536	}
537
538	/* Note receiving interface */
539	m->m_pkthdr.rcvif = ifp;
540
541	/* Update interface stats */
542	ifp->if_ipackets++;
543
544	(*ifp->if_input)(ifp, m);
545
546	/* Done */
547	return (0);
548}
549
550/*
551 * Shutdown processing.
552 */
553static int
554ng_eiface_rmnode(node_p node)
555{
556	const priv_p priv = NG_NODE_PRIVATE(node);
557	struct ifnet *const ifp = priv->ifp;
558
559	ether_ifdetach(ifp);
560	if_free(ifp);
561	free_unr(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		ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
591		break;
592	case MOD_UNLOAD:
593		delete_unrhdr(ng_eiface_unit);
594		break;
595	default:
596		error = EOPNOTSUPP;
597		break;
598	}
599	return (error);
600}
601