xref: /freebsd/sys/netgraph/ng_eiface.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
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_parse_struct_field ng_eiface_par_fields[]
61 	= NG_EIFACE_PAR_FIELDS;
62 
63 static const struct ng_parse_type ng_eiface_par_type = {
64 	&ng_parse_struct_type,
65 	&ng_eiface_par_fields
66 };
67 
68 static const struct ng_cmdlist ng_eiface_cmdlist[] = {
69 	{
70 	  NGM_EIFACE_COOKIE,
71 	  NGM_EIFACE_SET,
72 	  "set",
73 	  &ng_eiface_par_type,
74 	  NULL
75 	},
76 	{ 0 }
77 };
78 
79 
80 /* Node private data */
81 struct ng_eiface_private {
82 	struct ifnet   *ifp;	/* This interface */
83 	int	unit;		/* Interface unit number */
84 	struct arpcom   arpcom;	/* per-interface network data */
85 	node_p		node;	/* Our netgraph node */
86 	hook_p		ether;	/* Hook for ethernet stream */
87 };
88 typedef struct ng_eiface_private *priv_p;
89 
90 /* Interface methods */
91 static void     ng_eiface_init(void *xsc);
92 static void     ng_eiface_start(struct ifnet *ifp);
93 static int      ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
94 #ifdef DEBUG
95 static void     ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
96 #endif
97 
98 /* Netgraph methods */
99 static ng_constructor_t ng_eiface_constructor;
100 static ng_rcvmsg_t ng_eiface_rcvmsg;
101 static ng_shutdown_t ng_eiface_rmnode;
102 static ng_newhook_t ng_eiface_newhook;
103 static ng_rcvdata_t ng_eiface_rcvdata;
104 static ng_connect_t ng_eiface_connect;
105 static ng_disconnect_t ng_eiface_disconnect;
106 
107 /* Node type descriptor */
108 static struct ng_type typestruct = {
109 	NG_ABI_VERSION,
110 	NG_EIFACE_NODE_TYPE,
111 	NULL,
112 	ng_eiface_constructor,
113 	ng_eiface_rcvmsg,
114 	ng_eiface_rmnode,
115 	ng_eiface_newhook,
116 	NULL,
117 	ng_eiface_connect,
118 	ng_eiface_rcvdata,
119 	ng_eiface_disconnect,
120 	ng_eiface_cmdlist
121 };
122 NETGRAPH_INIT(eiface, &typestruct);
123 
124 static char     ng_eiface_ifname[] = NG_EIFACE_EIFACE_NAME;
125 
126 /* We keep a bitmap indicating which unit numbers are free.
127    One means the unit number is free, zero means it's taken. */
128 static int	*ng_eiface_units = NULL;
129 static int	ng_eiface_units_len = 0;
130 static int	ng_units_in_use = 0;
131 
132 #define UNITS_BITSPERWORD	(sizeof(*ng_eiface_units) * NBBY)
133 
134 
135 /************************************************************************
136 			HELPER STUFF
137  ************************************************************************/
138 /*
139  * Find the first free unit number for a new interface.
140  * Increase the size of the unit bitmap as necessary.
141  */
142 static __inline__ int
143 ng_eiface_get_unit(int *unit)
144 {
145 	int index, bit;
146 
147 	for (index = 0; index < ng_eiface_units_len
148 	    && ng_eiface_units[index] == 0; index++);
149 	if (index == ng_eiface_units_len) {		/* extend array */
150 		int i, *newarray, newlen;
151 
152 		newlen = (2 * ng_eiface_units_len) + 4;
153 		MALLOC(newarray, int *, newlen * sizeof(*ng_eiface_units),
154 		    M_NETGRAPH, M_NOWAIT);
155 		if (newarray == NULL)
156 			return (ENOMEM);
157 		bcopy(ng_eiface_units, newarray,
158 		    ng_eiface_units_len * sizeof(*ng_eiface_units));
159 		for (i = ng_eiface_units_len; i < newlen; i++)
160 			newarray[i] = ~0;
161 		if (ng_eiface_units != NULL)
162 			FREE(ng_eiface_units, M_NETGRAPH);
163 		ng_eiface_units = newarray;
164 		ng_eiface_units_len = newlen;
165 	}
166 	bit = ffs(ng_eiface_units[index]) - 1;
167 	KASSERT(bit >= 0 && bit <= UNITS_BITSPERWORD - 1,
168 	    ("%s: word=%d bit=%d", __func__, ng_eiface_units[index], bit));
169 	ng_eiface_units[index] &= ~(1 << bit);
170 	*unit = (index * UNITS_BITSPERWORD) + bit;
171 	ng_units_in_use++;
172 	return (0);
173 }
174 
175 /*
176  * Free a no longer needed unit number.
177  */
178 static __inline__ void
179 ng_eiface_free_unit(int unit)
180 {
181 	int index, bit;
182 
183 	index = unit / UNITS_BITSPERWORD;
184 	bit = unit % UNITS_BITSPERWORD;
185 	KASSERT(index < ng_eiface_units_len,
186 	    ("%s: unit=%d len=%d", __func__, unit, ng_eiface_units_len));
187 	KASSERT((ng_eiface_units[index] & (1 << bit)) == 0,
188 	    ("%s: unit=%d is free", __func__, unit));
189 	ng_eiface_units[index] |= (1 << bit);
190 	/*
191 	 * XXX We could think about reducing the size of ng_eiface_units[]
192 	 * XXX here if the last portion is all ones
193 	 * XXX At least free it if no more units.
194 	 * Needed if we are to eventually be able to unload.
195 	 */
196 	ng_units_in_use--;
197 	if (ng_units_in_use == 0) { /* XXX make SMP safe */
198 		FREE(ng_eiface_units, M_NETGRAPH);
199 		ng_eiface_units_len = 0;
200 		ng_eiface_units = NULL;
201 	}
202 }
203 
204 /************************************************************************
205 			INTERFACE STUFF
206  ************************************************************************/
207 
208 /*
209  * Process an ioctl for the virtual interface
210  */
211 static int
212 ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
213 {
214 	struct ifreq   *const ifr = (struct ifreq *)data;
215 	int		s, error = 0;
216 
217 #ifdef DEBUG
218 	ng_eiface_print_ioctl(ifp, command, data);
219 #endif
220 	s = splimp();
221 	switch (command)
222 	{
223 	/* These two are mostly handled at a higher layer */
224 	case SIOCSIFADDR:
225 		error = ether_ioctl(ifp, command, data);
226 		break;
227 	case SIOCGIFADDR:
228 		break;
229 
230 	/* Set flags */
231 	case SIOCSIFFLAGS:
232 		/*
233 		 * If the interface is marked up and stopped, then
234 		 * start it. If it is marked down and running,
235 		 * then stop it.
236 		 */
237 		if (ifr->ifr_flags & IFF_UP) {
238 			if (!(ifp->if_flags & IFF_RUNNING)) {
239 				ifp->if_flags &= ~(IFF_OACTIVE);
240 				ifp->if_flags |= IFF_RUNNING;
241 			}
242 		} else {
243 			if (ifp->if_flags & IFF_RUNNING)
244 				ifp->if_flags
245 					&= ~(IFF_RUNNING | IFF_OACTIVE);
246 		}
247 		break;
248 
249 	/* Set the interface MTU */
250 	case SIOCSIFMTU:
251 		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX
252 		|| ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
253 			error = EINVAL;
254 		else
255 			ifp->if_mtu = ifr->ifr_mtu;
256 		break;
257 
258 	/* Stuff that's not supported */
259 	case SIOCADDMULTI:
260 	case SIOCDELMULTI:
261 		error = 0;
262 		break;
263 	case SIOCSIFPHYS:
264 		error = EOPNOTSUPP;
265 		break;
266 
267 	default:
268 		error = EINVAL;
269 		break;
270 	}
271 	(void)splx(s);
272 	return (error);
273 }
274 
275 static void
276 ng_eiface_init(void *xsc)
277 {
278 	priv_p		sc = xsc;
279 	struct ifnet   *ifp = sc->ifp;
280 	int		s;
281 
282 	s = splimp();
283 
284 	ifp->if_flags |= IFF_RUNNING;
285 	ifp->if_flags &= ~IFF_OACTIVE;
286 
287 	splx(s);
288 }
289 
290 /*
291  * We simply relay the packet to the ether hook, if it is connected.
292  * We have been throughthe netgraph locking an are guaranteed to
293  * be the only code running in this node at this time.
294  */
295 static void
296 ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
297 {
298 	struct ifnet *ifp = arg1;
299 	const priv_p priv = (priv_p) ifp->if_softc;
300 	int		len, error = 0;
301 	struct mbuf    *m;
302 
303 	/* Check interface flags */
304 	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
305 		return;
306 
307 	/* Don't do anything if output is active */
308 	if (ifp->if_flags & IFF_OACTIVE)
309 		return;
310 
311 	ifp->if_flags |= IFF_OACTIVE;
312 
313 	/*
314 	 * Grab a packet to transmit.
315 	 */
316 	IF_DEQUEUE(&ifp->if_snd, m);
317 
318 	/* If there's nothing to send, return. */
319 	if (m == NULL) {
320 		ifp->if_flags &= ~IFF_OACTIVE;
321 		return;
322 	}
323 
324 	/* Berkeley packet filter
325 	 * Pass packet to bpf if there is a listener.
326 	 * XXX is this safe? locking?
327 	 */
328 	BPF_MTAP(ifp, m);
329 
330 	/* Copy length before the mbuf gets invalidated */
331 	len = m->m_pkthdr.len;
332 
333 	/*
334 	 * Send packet; if hook is not connected, mbuf will get
335 	 * freed.
336 	 */
337 	NG_SEND_DATA_ONLY(error, priv->ether, m);
338 
339 	/* Update stats */
340 	if (error == 0) {
341 		ifp->if_obytes += len;
342 		ifp->if_opackets++;
343 	}
344 	ifp->if_flags &= ~IFF_OACTIVE;
345 	return;
346 }
347 
348 /*
349  * This routine is called to deliver a packet out the interface.
350  * We simply queue the netgraph version to be called when netgraph locking
351  * allows it to happen.
352  * Until we know what the rest of the networking code is doing for
353  * locking, we don't know how we will interact with it.
354  * Take comfort from the fact that the ifnet struct is part of our
355  * private info and can't go away while we are queued.
356  * [Though we don't know it is still there now....]
357  * it is possible we don't gain anything from this because
358  * we would like to get the mbuf and queue it as data
359  * somehow, but we can't and if we did would we solve anything?
360  */
361 static void
362 ng_eiface_start(struct ifnet *ifp)
363 {
364 
365 	const priv_p priv = (priv_p) ifp->if_softc;
366 
367 	ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0);
368 }
369 
370 #ifdef DEBUG
371 /*
372  * Display an ioctl to the virtual interface
373  */
374 
375 static void
376 ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data){
377 	char		*str;
378 
379 	switch (command & IOC_DIRMASK)
380 	{
381 	case IOC_VOID:
382 		str = "IO";
383 		break;
384 	case IOC_OUT:
385 		str = "IOR";
386 		break;
387 	case IOC_IN:
388 		str = "IOW";
389 		break;
390 	case IOC_INOUT:
391 		str = "IORW";
392 		break;
393 	default:
394 		str = "IO??";
395 	}
396 	log(LOG_DEBUG, "%s%d: %s('%c', %d, char[%d])\n",
397 			ifp->if_name, ifp->if_unit,
398 			str,
399 			IOCGROUP(command),
400 			command & 0xff,
401 			IOCPARM_LEN(command));
402 }
403 #endif	/* DEBUG */
404 
405 /************************************************************************
406 			NETGRAPH NODE STUFF
407  ************************************************************************/
408 
409 /*
410  * Constructor for a node
411  */
412 static int
413 ng_eiface_constructor(node_p node)
414 {
415 	struct ifnet   *ifp;
416 	priv_p		priv;
417 	int		error = 0;
418 
419 	/* Allocate node and interface private structures */
420 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, 0);
421 	if (priv == NULL) {
422 		return (ENOMEM);
423 	}
424 	bzero(priv, sizeof(*priv));
425 
426 	ifp = &(priv->arpcom.ac_if);
427 
428 	/* Link them together */
429 	ifp->if_softc = priv;
430 	priv->ifp = ifp;
431 
432 	/* Get an interface unit number */
433 	if ((error = ng_eiface_get_unit(&priv->unit)) != 0) {
434 		FREE(priv, M_NETGRAPH);
435 		return (error);
436 	}
437 
438 	/* Link together node and private info */
439 	NG_NODE_SET_PRIVATE(node, priv);
440 	priv->node = node;
441 
442 	/* Initialize interface structure */
443 	ifp->if_name = ng_eiface_ifname;
444 	ifp->if_unit = priv->unit;
445 	ifp->if_init = ng_eiface_init;
446 	ifp->if_output = ether_output;
447 	ifp->if_start = ng_eiface_start;
448 	ifp->if_ioctl = ng_eiface_ioctl;
449 	ifp->if_watchdog = NULL;
450 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
451 	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
452 
453 	/*
454 	 * Give this node name * bzero(ifname, sizeof(ifname));
455 	 * sprintf(ifname, "if%s%d", ifp->if_name, ifp->if_unit); (void)
456 	 * ng_name_node(node, ifname);
457 	 */
458 
459 	/* Attach the interface */
460 	ether_ifattach(ifp, priv->arpcom.ac_enaddr);
461 
462 	/* Done */
463 	return (0);
464 }
465 
466 /*
467  * Give our ok for a hook to be added
468  */
469 static int
470 ng_eiface_newhook(node_p node, hook_p hook, const char *name)
471 {
472 	priv_p		priv = NG_NODE_PRIVATE(node);
473 
474 	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
475 		return (EPFNOSUPPORT);
476 	if (priv->ether != NULL)
477 		return (EISCONN);
478 	priv->ether = hook;
479 	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
480 
481 	return (0);
482 }
483 
484 /*
485  * Receive a control message
486  */
487 static int
488 ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
489 {
490 	priv_p		priv = NG_NODE_PRIVATE(node);
491 	struct ifnet   *const ifp = priv->ifp;
492 	struct ng_mesg *resp = NULL;
493 	int		error = 0;
494 	struct ng_mesg *msg;
495 
496 	NGI_GET_MSG(item, msg);
497 	switch		(msg->header.typecookie) {
498 	case NGM_EIFACE_COOKIE:
499 		switch (msg->header.cmd) {
500 		case NGM_EIFACE_SET:
501 		{
502 			struct ng_eiface_par *eaddr;
503 			struct ifaddr *ifa;
504 			struct sockaddr_dl *sdl;
505 
506 			if (msg->header.arglen != sizeof(struct ng_eiface_par)){
507 				error = EINVAL;
508 				break;
509 			}
510 			eaddr = (struct ng_eiface_par *)(msg->data);
511 
512 			priv->arpcom.ac_enaddr[0] = eaddr->oct0;
513 			priv->arpcom.ac_enaddr[1] = eaddr->oct1;
514 			priv->arpcom.ac_enaddr[2] = eaddr->oct2;
515 			priv->arpcom.ac_enaddr[3] = eaddr->oct3;
516 			priv->arpcom.ac_enaddr[4] = eaddr->oct4;
517 			priv->arpcom.ac_enaddr[5] = eaddr->oct5;
518 
519 			/* And put it in the ifaddr list */
520 #define IFP2AC(IFP) ((struct arpcom *)IFP)
521 			TAILQ_FOREACH(ifa, &(ifp->if_addrhead), ifa_link) {
522 				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
523 				if (sdl->sdl_type == IFT_ETHER) {
524 					bcopy((IFP2AC(ifp))->ac_enaddr,
525 						LLADDR(sdl), ifp->if_addrlen);
526 					break;
527 				}
528 			}
529 			break;
530 		}
531 
532 		case NGM_EIFACE_GET_IFNAME:
533 		{
534 			struct ng_eiface_ifname *arg;
535 
536 			NG_MKRESPONSE(resp, msg, sizeof(*arg), M_NOWAIT);
537 			if (resp == NULL) {
538 				error = ENOMEM;
539 				break;
540 			}
541 			arg = (struct ng_eiface_ifname *)resp->data;
542 			sprintf(arg->ngif_name,
543 				"%s%d", ifp->if_name, ifp->if_unit);
544 			break;
545 		}
546 
547 		case NGM_EIFACE_GET_IFADDRS:
548 		{
549 			struct ifaddr  *ifa;
550 			caddr_t		ptr;
551 			int		buflen;
552 
553 #define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
554 
555 			/* Determine size of response and allocate it */
556 			buflen = 0;
557 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
558 			buflen += SA_SIZE(ifa->ifa_addr);
559 			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
560 			if (resp == NULL) {
561 				error = ENOMEM;
562 				break;
563 			}
564 			/* Add addresses */
565 			ptr = resp->data;
566 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
567 				const int       len = SA_SIZE(ifa->ifa_addr);
568 
569 				if (buflen < len) {
570 					log(LOG_ERR, "%s%d: len changed?\n",
571 					ifp->if_name, ifp->if_unit);
572 					break;
573 				}
574 				bcopy(ifa->ifa_addr, ptr, len);
575 				ptr += len;
576 				buflen -= len;
577 			}
578 			break;
579 #undef SA_SIZE
580 		}
581 
582 		default:
583 			error = EINVAL;
584 			break;
585 		} /* end of inner switch() */
586 		break;
587 	default:
588 		error = EINVAL;
589 		break;
590 	}
591 	NG_RESPOND_MSG(error, node, item, resp);
592 	NG_FREE_MSG(msg);
593 	return (error);
594 }
595 
596 /*
597  * Recive data from a hook. Pass the packet to the ether_input routine.
598  */
599 static int
600 ng_eiface_rcvdata(hook_p hook, item_p item)
601 {
602 	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
603 	struct ifnet   *const ifp = priv->ifp;
604 	struct mbuf *m;
605 
606 	NGI_GET_M(item, m);
607 	/* Meta-data ends its life here... */
608         NG_FREE_ITEM(item);
609 
610 	if (m == NULL)
611 	{
612 		printf("ng_eiface: mbuf is null.\n");
613 		return (EINVAL);
614 	}
615 	if (!(ifp->if_flags & IFF_UP)) {
616 		return (ENETDOWN);
617 	}
618 
619 	/* Note receiving interface */
620 	m->m_pkthdr.rcvif = ifp;
621 
622 	/* Update interface stats */
623 	ifp->if_ipackets++;
624 
625 	(*ifp->if_input)(ifp, m);
626 
627 	/* Done */
628 	return (0);
629 }
630 
631 /*
632  * the node.
633  */
634 static int
635 ng_eiface_rmnode(node_p node)
636 {
637 	priv_p		priv = NG_NODE_PRIVATE(node);
638 	struct ifnet   *const ifp = priv->ifp;
639 
640 	ether_ifdetach(ifp);
641 	ng_eiface_free_unit(priv->unit);
642 	FREE(priv, M_NETGRAPH);
643 	NG_NODE_SET_PRIVATE(node, NULL);
644 	NG_NODE_UNREF(node);
645 	return (0);
646 }
647 
648 
649 /*
650  * This is called once we've already connected a new hook to the other node.
651  * It gives us a chance to balk at the last minute.
652  */
653 static int
654 ng_eiface_connect(hook_p hook)
655 {
656 	/* be really amiable and just say "YUP that's OK by me! " */
657 	return (0);
658 }
659 
660 /*
661  * Hook disconnection
662  */
663 static int
664 ng_eiface_disconnect(hook_p hook)
665 {
666 	priv_p		priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
667 
668 	priv->ether = NULL;
669 	return (0);
670 }
671