xref: /freebsd/sys/netgraph/ng_eiface.c (revision 2357939bc239bd5334a169b62313806178dd8f30) 
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  * $FreeBSD$
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 
60 static 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 */
73 struct 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 };
80 typedef struct ng_eiface_private *priv_p;
81 
82 /* Interface methods */
83 static void     ng_eiface_init(void *xsc);
84 static void     ng_eiface_start(struct ifnet *ifp);
85 static int      ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
86 #ifdef DEBUG
87 static void     ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
88 #endif
89 
90 /* Netgraph methods */
91 static ng_constructor_t ng_eiface_constructor;
92 static ng_rcvmsg_t ng_eiface_rcvmsg;
93 static ng_shutdown_t ng_eiface_rmnode;
94 static ng_newhook_t ng_eiface_newhook;
95 static ng_rcvdata_t ng_eiface_rcvdata;
96 static ng_connect_t ng_eiface_connect;
97 static ng_disconnect_t ng_eiface_disconnect;
98 
99 /* Node type descriptor */
100 static 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 };
114 NETGRAPH_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. */
118 static int	*ng_eiface_units = NULL;
119 static int	ng_eiface_units_len = 0;
120 static 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  */
132 static __inline__ int
133 ng_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  */
168 static __inline__ void
169 ng_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  */
201 static int
202 ng_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 
265 static void
266 ng_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  */
285 static void
286 ng_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  */
351 static void
352 ng_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 
365 static void
366 ng_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  */
402 static int
403 ng_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  */
458 static int
459 ng_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  */
476 static int
477 ng_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  */
581 static int
582 ng_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  */
617 static int
618 ng_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  */
636 static int
637 ng_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  */
646 static int
647 ng_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