xref: /freebsd/sys/netgraph/ng_eiface.c (revision aa0a1e58) 
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_snd.ifq_maxlen = ifqmaxlen;
373 	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
374 	ifp->if_capabilities = IFCAP_VLAN_MTU | IFCAP_JUMBO_MTU;
375 	ifp->if_capenable = IFCAP_VLAN_MTU | IFCAP_JUMBO_MTU;
376 
377 	/* Give this node the same name as the interface (if possible) */
378 	if (ng_name_node(node, ifp->if_xname) != 0)
379 		log(LOG_WARNING, "%s: can't acquire netgraph name\n",
380 		    ifp->if_xname);
381 
382 	/* Attach the interface */
383 	ether_ifattach(ifp, eaddr);
384 
385 	/* Done */
386 	return (0);
387 }
388 
389 /*
390  * Give our ok for a hook to be added
391  */
392 static int
393 ng_eiface_newhook(node_p node, hook_p hook, const char *name)
394 {
395 	priv_p priv = NG_NODE_PRIVATE(node);
396 	struct ifnet *ifp = priv->ifp;
397 
398 	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
399 		return (EPFNOSUPPORT);
400 	if (priv->ether != NULL)
401 		return (EISCONN);
402 	priv->ether = hook;
403 	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
404 	NG_HOOK_SET_TO_INBOUND(hook);
405 
406 	if_link_state_change(ifp, LINK_STATE_UP);
407 
408 	return (0);
409 }
410 
411 /*
412  * Receive a control message
413  */
414 static int
415 ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
416 {
417 	const priv_p priv = NG_NODE_PRIVATE(node);
418 	struct ifnet *const ifp = priv->ifp;
419 	struct ng_mesg *resp = NULL;
420 	int error = 0;
421 	struct ng_mesg *msg;
422 
423 	NGI_GET_MSG(item, msg);
424 	switch (msg->header.typecookie) {
425 	case NGM_EIFACE_COOKIE:
426 		switch (msg->header.cmd) {
427 
428 		case NGM_EIFACE_SET:
429 		    {
430 			if (msg->header.arglen != ETHER_ADDR_LEN) {
431 				error = EINVAL;
432 				break;
433 			}
434 			error = if_setlladdr(priv->ifp,
435 			    (u_char *)msg->data, ETHER_ADDR_LEN);
436 			EVENTHANDLER_INVOKE(iflladdr_event, priv->ifp);
437 			break;
438 		    }
439 
440 		case NGM_EIFACE_GET_IFNAME:
441 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
442 			if (resp == NULL) {
443 				error = ENOMEM;
444 				break;
445 			}
446 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
447 			break;
448 
449 		case NGM_EIFACE_GET_IFADDRS:
450 		    {
451 			struct ifaddr *ifa;
452 			caddr_t ptr;
453 			int buflen;
454 
455 			/* Determine size of response and allocate it */
456 			buflen = 0;
457 			if_addr_rlock(ifp);
458 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
459 				buflen += SA_SIZE(ifa->ifa_addr);
460 			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
461 			if (resp == NULL) {
462 				if_addr_runlock(ifp);
463 				error = ENOMEM;
464 				break;
465 			}
466 
467 			/* Add addresses */
468 			ptr = resp->data;
469 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
470 				const int len = SA_SIZE(ifa->ifa_addr);
471 
472 				if (buflen < len) {
473 					log(LOG_ERR, "%s: len changed?\n",
474 					    ifp->if_xname);
475 					break;
476 				}
477 				bcopy(ifa->ifa_addr, ptr, len);
478 				ptr += len;
479 				buflen -= len;
480 			}
481 			if_addr_runlock(ifp);
482 			break;
483 		    }
484 
485 		default:
486 			error = EINVAL;
487 			break;
488 		} /* end of inner switch() */
489 		break;
490 	case NGM_FLOW_COOKIE:
491 		switch (msg->header.cmd) {
492 		case NGM_LINK_IS_UP:
493 			if_link_state_change(ifp, LINK_STATE_UP);
494 			break;
495 		case NGM_LINK_IS_DOWN:
496 			if_link_state_change(ifp, LINK_STATE_DOWN);
497 			break;
498 		default:
499 			break;
500 		}
501 		break;
502 	default:
503 		error = EINVAL;
504 		break;
505 	}
506 	NG_RESPOND_MSG(error, node, item, resp);
507 	NG_FREE_MSG(msg);
508 	return (error);
509 }
510 
511 /*
512  * Receive data from a hook. Pass the packet to the ether_input routine.
513  */
514 static int
515 ng_eiface_rcvdata(hook_p hook, item_p item)
516 {
517 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
518 	struct ifnet *const ifp = priv->ifp;
519 	struct mbuf *m;
520 
521 	NGI_GET_M(item, m);
522 	NG_FREE_ITEM(item);
523 
524 	if (!((ifp->if_flags & IFF_UP) &&
525 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
526 		NG_FREE_M(m);
527 		return (ENETDOWN);
528 	}
529 
530 	if (m->m_len < ETHER_HDR_LEN) {
531 		m = m_pullup(m, ETHER_HDR_LEN);
532 		if (m == NULL)
533 			return (EINVAL);
534 	}
535 
536 	/* Note receiving interface */
537 	m->m_pkthdr.rcvif = ifp;
538 
539 	/* Update interface stats */
540 	ifp->if_ipackets++;
541 
542 	(*ifp->if_input)(ifp, m);
543 
544 	/* Done */
545 	return (0);
546 }
547 
548 /*
549  * Shutdown processing.
550  */
551 static int
552 ng_eiface_rmnode(node_p node)
553 {
554 	const priv_p priv = NG_NODE_PRIVATE(node);
555 	struct ifnet *const ifp = priv->ifp;
556 
557 	/*
558 	 * the ifnet may be in a different vnet than the netgraph node,
559 	 * hence we have to change the current vnet context here.
560 	 */
561 	CURVNET_SET_QUIET(ifp->if_vnet);
562 	ether_ifdetach(ifp);
563 	if_free(ifp);
564 	CURVNET_RESTORE();
565 	free_unr(V_ng_eiface_unit, priv->unit);
566 	free(priv, M_NETGRAPH);
567 	NG_NODE_SET_PRIVATE(node, NULL);
568 	NG_NODE_UNREF(node);
569 	return (0);
570 }
571 
572 /*
573  * Hook disconnection
574  */
575 static int
576 ng_eiface_disconnect(hook_p hook)
577 {
578 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
579 
580 	priv->ether = NULL;
581 	return (0);
582 }
583 
584 /*
585  * Handle loading and unloading for this node type.
586  */
587 static int
588 ng_eiface_mod_event(module_t mod, int event, void *data)
589 {
590 	int error = 0;
591 
592 	switch (event) {
593 	case MOD_LOAD:
594 	case MOD_UNLOAD:
595 		break;
596 	default:
597 		error = EOPNOTSUPP;
598 		break;
599 	}
600 	return (error);
601 }
602 
603 static void
604 vnet_ng_eiface_init(const void *unused)
605 {
606 
607 	V_ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
608 }
609 VNET_SYSINIT(vnet_ng_eiface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
610     vnet_ng_eiface_init, NULL);
611 
612 static void
613 vnet_ng_eiface_uninit(const void *unused)
614 {
615 
616 	delete_unrhdr(V_ng_eiface_unit);
617 }
618 VNET_SYSUNINIT(vnet_ng_eiface_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY,
619    vnet_ng_eiface_uninit, NULL);
620