xref: /freebsd/sys/netgraph/ng_eiface.c (revision 830940567b49bb0c08dfaed40418999e76616909) 
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 #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/proc.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_types.h>
45 #include <net/netisr.h>
46 #include <net/route.h>
47 #include <net/vnet.h>
48 
49 #include <netgraph/ng_message.h>
50 #include <netgraph/netgraph.h>
51 #include <netgraph/ng_parse.h>
52 #include <netgraph/ng_eiface.h>
53 
54 #include <net/bpf.h>
55 #include <net/ethernet.h>
56 #include <net/if_arp.h>
57 
58 static const struct ng_cmdlist ng_eiface_cmdlist[] = {
59 	{
60 	  NGM_EIFACE_COOKIE,
61 	  NGM_EIFACE_GET_IFNAME,
62 	  "getifname",
63 	  NULL,
64 	  &ng_parse_string_type
65 	},
66 	{
67 	  NGM_EIFACE_COOKIE,
68 	  NGM_EIFACE_SET,
69 	  "set",
70 	  &ng_parse_enaddr_type,
71 	  NULL
72 	},
73 	{ 0 }
74 };
75 
76 /* Node private data */
77 struct ng_eiface_private {
78 	struct ifnet	*ifp;		/* per-interface network data */
79 	int		unit;		/* Interface unit number */
80 	node_p		node;		/* Our netgraph node */
81 	hook_p		ether;		/* Hook for ethernet stream */
82 };
83 typedef struct ng_eiface_private *priv_p;
84 
85 /* Interface methods */
86 static void	ng_eiface_init(void *xsc);
87 static void	ng_eiface_start(struct ifnet *ifp);
88 static int	ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
89 #ifdef DEBUG
90 static void	ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
91 #endif
92 
93 /* Netgraph methods */
94 static int		ng_eiface_mod_event(module_t, int, void *);
95 static ng_constructor_t	ng_eiface_constructor;
96 static ng_rcvmsg_t	ng_eiface_rcvmsg;
97 static ng_shutdown_t	ng_eiface_rmnode;
98 static ng_newhook_t	ng_eiface_newhook;
99 static ng_rcvdata_t	ng_eiface_rcvdata;
100 static ng_disconnect_t	ng_eiface_disconnect;
101 
102 /* Node type descriptor */
103 static struct ng_type typestruct = {
104 	.version =	NG_ABI_VERSION,
105 	.name =		NG_EIFACE_NODE_TYPE,
106 	.mod_event =	ng_eiface_mod_event,
107 	.constructor =	ng_eiface_constructor,
108 	.rcvmsg =	ng_eiface_rcvmsg,
109 	.shutdown =	ng_eiface_rmnode,
110 	.newhook =	ng_eiface_newhook,
111 	.rcvdata =	ng_eiface_rcvdata,
112 	.disconnect =	ng_eiface_disconnect,
113 	.cmdlist =	ng_eiface_cmdlist
114 };
115 NETGRAPH_INIT(eiface, &typestruct);
116 
117 static VNET_DEFINE(struct unrhdr *, ng_eiface_unit);
118 #define	V_ng_eiface_unit		VNET(ng_eiface_unit)
119 
120 /************************************************************************
121 			INTERFACE STUFF
122  ************************************************************************/
123 
124 /*
125  * Process an ioctl for the virtual interface
126  */
127 static int
128 ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
129 {
130 	struct ifreq *const ifr = (struct ifreq *)data;
131 	int s, error = 0;
132 
133 #ifdef DEBUG
134 	ng_eiface_print_ioctl(ifp, command, data);
135 #endif
136 	s = splimp();
137 	switch (command) {
138 
139 	/* These two are mostly handled at a higher layer */
140 	case SIOCSIFADDR:
141 		error = ether_ioctl(ifp, command, data);
142 		break;
143 	case SIOCGIFADDR:
144 		break;
145 
146 	/* Set flags */
147 	case SIOCSIFFLAGS:
148 		/*
149 		 * If the interface is marked up and stopped, then start it.
150 		 * If it is marked down and running, then stop it.
151 		 */
152 		if (ifp->if_flags & IFF_UP) {
153 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
154 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
155 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
156 			}
157 		} else {
158 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
159 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
160 				    IFF_DRV_OACTIVE);
161 		}
162 		break;
163 
164 	/* Set the interface MTU */
165 	case SIOCSIFMTU:
166 		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX ||
167 		    ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
168 			error = EINVAL;
169 		else
170 			ifp->if_mtu = ifr->ifr_mtu;
171 		break;
172 
173 	/* Stuff that's not supported */
174 	case SIOCADDMULTI:
175 	case SIOCDELMULTI:
176 		error = 0;
177 		break;
178 	case SIOCSIFPHYS:
179 		error = EOPNOTSUPP;
180 		break;
181 
182 	default:
183 		error = EINVAL;
184 		break;
185 	}
186 	splx(s);
187 	return (error);
188 }
189 
190 static void
191 ng_eiface_init(void *xsc)
192 {
193 	priv_p sc = xsc;
194 	struct ifnet *ifp = sc->ifp;
195 	int s;
196 
197 	s = splimp();
198 
199 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
200 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
201 
202 	splx(s);
203 }
204 
205 /*
206  * We simply relay the packet to the "ether" hook, if it is connected.
207  * We have been through the netgraph locking and are guaranteed to
208  * be the only code running in this node at this time.
209  */
210 static void
211 ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
212 {
213 	struct ifnet *ifp = arg1;
214 	const priv_p priv = (priv_p)ifp->if_softc;
215 	int error = 0;
216 	struct mbuf *m;
217 
218 	/* Check interface flags */
219 
220 	if (!((ifp->if_flags & IFF_UP) &&
221 	    (ifp->if_drv_flags & IFF_DRV_RUNNING)))
222 		return;
223 
224 	for (;;) {
225 		/*
226 		 * Grab a packet to transmit.
227 		 */
228 		IF_DEQUEUE(&ifp->if_snd, m);
229 
230 		/* If there's nothing to send, break. */
231 		if (m == NULL)
232 			break;
233 
234 		/*
235 		 * Berkeley packet filter.
236 		 * Pass packet to bpf if there is a listener.
237 		 * XXX is this safe? locking?
238 		 */
239 		BPF_MTAP(ifp, m);
240 
241 		if (ifp->if_flags & IFF_MONITOR) {
242 			ifp->if_ipackets++;
243 			m_freem(m);
244 			continue;
245 		}
246 
247 		/*
248 		 * Send packet; if hook is not connected, mbuf will get
249 		 * freed.
250 		 */
251 		NG_OUTBOUND_THREAD_REF();
252 		NG_SEND_DATA_ONLY(error, priv->ether, m);
253 		NG_OUTBOUND_THREAD_UNREF();
254 
255 		/* Update stats */
256 		if (error == 0)
257 			ifp->if_opackets++;
258 		else
259 			ifp->if_oerrors++;
260 	}
261 
262 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
263 
264 	return;
265 }
266 
267 /*
268  * This routine is called to deliver a packet out the interface.
269  * We simply queue the netgraph version to be called when netgraph locking
270  * allows it to happen.
271  * Until we know what the rest of the networking code is doing for
272  * locking, we don't know how we will interact with it.
273  * Take comfort from the fact that the ifnet struct is part of our
274  * private info and can't go away while we are queued.
275  * [Though we don't know it is still there now....]
276  * it is possible we don't gain anything from this because
277  * we would like to get the mbuf and queue it as data
278  * somehow, but we can't and if we did would we solve anything?
279  */
280 static void
281 ng_eiface_start(struct ifnet *ifp)
282 {
283 
284 	const priv_p priv = (priv_p)ifp->if_softc;
285 
286 	/* Don't do anything if output is active */
287 	if (ifp->if_drv_flags & IFF_DRV_OACTIVE)
288 		return;
289 
290 	ifp->if_drv_flags |= IFF_DRV_OACTIVE;
291 
292 	if (ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0) != 0)
293 		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
294 }
295 
296 #ifdef DEBUG
297 /*
298  * Display an ioctl to the virtual interface
299  */
300 
301 static void
302 ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
303 {
304 	char *str;
305 
306 	switch (command & IOC_DIRMASK) {
307 	case IOC_VOID:
308 		str = "IO";
309 		break;
310 	case IOC_OUT:
311 		str = "IOR";
312 		break;
313 	case IOC_IN:
314 		str = "IOW";
315 		break;
316 	case IOC_INOUT:
317 		str = "IORW";
318 		break;
319 	default:
320 		str = "IO??";
321 	}
322 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
323 	    ifp->if_xname,
324 	    str,
325 	    IOCGROUP(command),
326 	    command & 0xff,
327 	    IOCPARM_LEN(command));
328 }
329 #endif /* DEBUG */
330 
331 /************************************************************************
332 			NETGRAPH NODE STUFF
333  ************************************************************************/
334 
335 /*
336  * Constructor for a node
337  */
338 static int
339 ng_eiface_constructor(node_p node)
340 {
341 	struct ifnet *ifp;
342 	priv_p priv;
343 	u_char eaddr[6] = {0,0,0,0,0,0};
344 
345 	/* Allocate node and interface private structures */
346 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
347 	if (priv == NULL)
348 		return (ENOMEM);
349 
350 	ifp = priv->ifp = if_alloc(IFT_ETHER);
351 	if (ifp == NULL) {
352 		free(priv, M_NETGRAPH);
353 		return (ENOSPC);
354 	}
355 
356 	/* Link them together */
357 	ifp->if_softc = priv;
358 
359 	/* Get an interface unit number */
360 	priv->unit = alloc_unr(V_ng_eiface_unit);
361 
362 	/* Link together node and private info */
363 	NG_NODE_SET_PRIVATE(node, priv);
364 	priv->node = node;
365 
366 	/* Initialize interface structure */
367 	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
368 	ifp->if_init = ng_eiface_init;
369 	ifp->if_output = ether_output;
370 	ifp->if_start = ng_eiface_start;
371 	ifp->if_ioctl = ng_eiface_ioctl;
372 	ifp->if_watchdog = NULL;
373 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
374 	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
375 
376 	/* Give this node the same name as the interface (if possible) */
377 	if (ng_name_node(node, ifp->if_xname) != 0)
378 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
379 		    ifp->if_xname);
380 
381 	/* Attach the interface */
382 	ether_ifattach(ifp, eaddr);
383 
384 	/* Done */
385 	return (0);
386 }
387 
388 /*
389  * Give our ok for a hook to be added
390  */
391 static int
392 ng_eiface_newhook(node_p node, hook_p hook, const char *name)
393 {
394 	priv_p priv = NG_NODE_PRIVATE(node);
395 	struct ifnet *ifp = priv->ifp;
396 
397 	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
398 		return (EPFNOSUPPORT);
399 	if (priv->ether != NULL)
400 		return (EISCONN);
401 	priv->ether = hook;
402 	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
403 	NG_HOOK_SET_TO_INBOUND(hook);
404 
405 	if_link_state_change(ifp, LINK_STATE_UP);
406 
407 	return (0);
408 }
409 
410 /*
411  * Receive a control message
412  */
413 static int
414 ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
415 {
416 	const priv_p priv = NG_NODE_PRIVATE(node);
417 	struct ifnet *const ifp = priv->ifp;
418 	struct ng_mesg *resp = NULL;
419 	int error = 0;
420 	struct ng_mesg *msg;
421 
422 	NGI_GET_MSG(item, msg);
423 	switch (msg->header.typecookie) {
424 	case NGM_EIFACE_COOKIE:
425 		switch (msg->header.cmd) {
426 
427 		case NGM_EIFACE_SET:
428 		    {
429 			if (msg->header.arglen != ETHER_ADDR_LEN) {
430 				error = EINVAL;
431 				break;
432 			}
433 			error = if_setlladdr(priv->ifp,
434 			    (u_char *)msg->data, ETHER_ADDR_LEN);
435 			break;
436 		    }
437 
438 		case NGM_EIFACE_GET_IFNAME:
439 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
440 			if (resp == NULL) {
441 				error = ENOMEM;
442 				break;
443 			}
444 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
445 			break;
446 
447 		case NGM_EIFACE_GET_IFADDRS:
448 		    {
449 			struct ifaddr *ifa;
450 			caddr_t ptr;
451 			int buflen;
452 
453 			/* Determine size of response and allocate it */
454 			buflen = 0;
455 			if_addr_rlock(ifp);
456 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
457 				buflen += SA_SIZE(ifa->ifa_addr);
458 			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
459 			if (resp == NULL) {
460 				if_addr_runlock(ifp);
461 				error = ENOMEM;
462 				break;
463 			}
464 
465 			/* Add addresses */
466 			ptr = resp->data;
467 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
468 				const int len = SA_SIZE(ifa->ifa_addr);
469 
470 				if (buflen < len) {
471 					log(LOG_ERR, "%s: len changed?\n",
472 					    ifp->if_xname);
473 					break;
474 				}
475 				bcopy(ifa->ifa_addr, ptr, len);
476 				ptr += len;
477 				buflen -= len;
478 			}
479 			if_addr_runlock(ifp);
480 			break;
481 		    }
482 
483 		default:
484 			error = EINVAL;
485 			break;
486 		} /* end of inner switch() */
487 		break;
488 	case NGM_FLOW_COOKIE:
489 		switch (msg->header.cmd) {
490 		case NGM_LINK_IS_UP:
491 			if_link_state_change(ifp, LINK_STATE_UP);
492 			break;
493 		case NGM_LINK_IS_DOWN:
494 			if_link_state_change(ifp, LINK_STATE_DOWN);
495 			break;
496 		default:
497 			break;
498 		}
499 		break;
500 	default:
501 		error = EINVAL;
502 		break;
503 	}
504 	NG_RESPOND_MSG(error, node, item, resp);
505 	NG_FREE_MSG(msg);
506 	return (error);
507 }
508 
509 /*
510  * Receive data from a hook. Pass the packet to the ether_input routine.
511  */
512 static int
513 ng_eiface_rcvdata(hook_p hook, item_p item)
514 {
515 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
516 	struct ifnet *const ifp = priv->ifp;
517 	struct mbuf *m;
518 
519 	NGI_GET_M(item, m);
520 	NG_FREE_ITEM(item);
521 
522 	if (!((ifp->if_flags & IFF_UP) &&
523 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
524 		NG_FREE_M(m);
525 		return (ENETDOWN);
526 	}
527 
528 	if (m->m_len < ETHER_HDR_LEN) {
529 		m = m_pullup(m, ETHER_HDR_LEN);
530 		if (m == NULL)
531 			return (EINVAL);
532 	}
533 
534 	/* Note receiving interface */
535 	m->m_pkthdr.rcvif = ifp;
536 
537 	/* Update interface stats */
538 	ifp->if_ipackets++;
539 
540 	(*ifp->if_input)(ifp, m);
541 
542 	/* Done */
543 	return (0);
544 }
545 
546 /*
547  * Shutdown processing.
548  */
549 static int
550 ng_eiface_rmnode(node_p node)
551 {
552 	const priv_p priv = NG_NODE_PRIVATE(node);
553 	struct ifnet *const ifp = priv->ifp;
554 
555 	/*
556 	 * the ifnet may be in a different vnet than the netgraph node,
557 	 * hence we have to change the current vnet context here.
558 	 */
559 	CURVNET_SET_QUIET(ifp->if_vnet);
560 	ether_ifdetach(ifp);
561 	if_free(ifp);
562 	CURVNET_RESTORE();
563 	free_unr(V_ng_eiface_unit, priv->unit);
564 	free(priv, M_NETGRAPH);
565 	NG_NODE_SET_PRIVATE(node, NULL);
566 	NG_NODE_UNREF(node);
567 	return (0);
568 }
569 
570 /*
571  * Hook disconnection
572  */
573 static int
574 ng_eiface_disconnect(hook_p hook)
575 {
576 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
577 
578 	priv->ether = NULL;
579 	return (0);
580 }
581 
582 /*
583  * Handle loading and unloading for this node type.
584  */
585 static int
586 ng_eiface_mod_event(module_t mod, int event, void *data)
587 {
588 	int error = 0;
589 
590 	switch (event) {
591 	case MOD_LOAD:
592 	case MOD_UNLOAD:
593 		break;
594 	default:
595 		error = EOPNOTSUPP;
596 		break;
597 	}
598 	return (error);
599 }
600 
601 static void
602 vnet_ng_eiface_init(const void *unused)
603 {
604 
605 	V_ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
606 }
607 VNET_SYSINIT(vnet_ng_eiface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
608     vnet_ng_eiface_init, NULL);
609 
610 static void
611 vnet_ng_eiface_uninit(const void *unused)
612 {
613 
614 	delete_unrhdr(V_ng_eiface_unit);
615 }
616 VNET_SYSUNINIT(vnet_ng_eiface_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY,
617    vnet_ng_eiface_uninit, NULL);
618