xref: /freebsd/sys/netgraph/ng_eiface.c (revision 39beb93c) 
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/sockio.h>
39 #include <sys/socket.h>
40 #include <sys/syslog.h>
41 #include <sys/vimage.h>
42 
43 #include <net/if.h>
44 #include <net/if_types.h>
45 #include <net/netisr.h>
46 #include <net/route.h>
47 
48 #include <netgraph/ng_message.h>
49 #include <netgraph/netgraph.h>
50 #include <netgraph/ng_parse.h>
51 #include <netgraph/ng_eiface.h>
52 
53 #include <net/bpf.h>
54 #include <net/ethernet.h>
55 #include <net/if_arp.h>
56 
57 static const struct ng_cmdlist ng_eiface_cmdlist[] = {
58 	{
59 	  NGM_EIFACE_COOKIE,
60 	  NGM_EIFACE_GET_IFNAME,
61 	  "getifname",
62 	  NULL,
63 	  &ng_parse_string_type
64 	},
65 	{
66 	  NGM_EIFACE_COOKIE,
67 	  NGM_EIFACE_SET,
68 	  "set",
69 	  &ng_parse_enaddr_type,
70 	  NULL
71 	},
72 	{ 0 }
73 };
74 
75 /* Node private data */
76 struct ng_eiface_private {
77 	struct ifnet	*ifp;		/* per-interface network data */
78 	int		unit;		/* Interface unit number */
79 	node_p		node;		/* Our netgraph node */
80 	hook_p		ether;		/* Hook for ethernet stream */
81 };
82 typedef struct ng_eiface_private *priv_p;
83 
84 /* Interface methods */
85 static void	ng_eiface_init(void *xsc);
86 static void	ng_eiface_start(struct ifnet *ifp);
87 static int	ng_eiface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
88 #ifdef DEBUG
89 static void	ng_eiface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
90 #endif
91 
92 /* Netgraph methods */
93 static int		ng_eiface_mod_event(module_t, int, void *);
94 static ng_constructor_t	ng_eiface_constructor;
95 static ng_rcvmsg_t	ng_eiface_rcvmsg;
96 static ng_shutdown_t	ng_eiface_rmnode;
97 static ng_newhook_t	ng_eiface_newhook;
98 static ng_rcvdata_t	ng_eiface_rcvdata;
99 static ng_disconnect_t	ng_eiface_disconnect;
100 
101 /* Node type descriptor */
102 static struct ng_type typestruct = {
103 	.version =	NG_ABI_VERSION,
104 	.name =		NG_EIFACE_NODE_TYPE,
105 	.mod_event =	ng_eiface_mod_event,
106 	.constructor =	ng_eiface_constructor,
107 	.rcvmsg =	ng_eiface_rcvmsg,
108 	.shutdown =	ng_eiface_rmnode,
109 	.newhook =	ng_eiface_newhook,
110 	.rcvdata =	ng_eiface_rcvdata,
111 	.disconnect =	ng_eiface_disconnect,
112 	.cmdlist =	ng_eiface_cmdlist
113 };
114 NETGRAPH_INIT(eiface, &typestruct);
115 
116 #ifdef VIMAGE_GLOBALS
117 static struct unrhdr	*ng_eiface_unit;
118 #endif
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_SEND_DATA_ONLY(error, priv->ether, m);
252 
253 		/* Update stats */
254 		if (error == 0)
255 			ifp->if_opackets++;
256 		else
257 			ifp->if_oerrors++;
258 	}
259 
260 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
261 
262 	return;
263 }
264 
265 /*
266  * This routine is called to deliver a packet out the interface.
267  * We simply queue the netgraph version to be called when netgraph locking
268  * allows it to happen.
269  * Until we know what the rest of the networking code is doing for
270  * locking, we don't know how we will interact with it.
271  * Take comfort from the fact that the ifnet struct is part of our
272  * private info and can't go away while we are queued.
273  * [Though we don't know it is still there now....]
274  * it is possible we don't gain anything from this because
275  * we would like to get the mbuf and queue it as data
276  * somehow, but we can't and if we did would we solve anything?
277  */
278 static void
279 ng_eiface_start(struct ifnet *ifp)
280 {
281 
282 	const priv_p priv = (priv_p)ifp->if_softc;
283 
284 	/* Don't do anything if output is active */
285 	if (ifp->if_drv_flags & IFF_DRV_OACTIVE)
286 		return;
287 
288 	ifp->if_drv_flags |= IFF_DRV_OACTIVE;
289 
290 	if (ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0) != 0)
291 		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
292 }
293 
294 #ifdef DEBUG
295 /*
296  * Display an ioctl to the virtual interface
297  */
298 
299 static void
300 ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
301 {
302 	char *str;
303 
304 	switch (command & IOC_DIRMASK) {
305 	case IOC_VOID:
306 		str = "IO";
307 		break;
308 	case IOC_OUT:
309 		str = "IOR";
310 		break;
311 	case IOC_IN:
312 		str = "IOW";
313 		break;
314 	case IOC_INOUT:
315 		str = "IORW";
316 		break;
317 	default:
318 		str = "IO??";
319 	}
320 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
321 	    ifp->if_xname,
322 	    str,
323 	    IOCGROUP(command),
324 	    command & 0xff,
325 	    IOCPARM_LEN(command));
326 }
327 #endif /* DEBUG */
328 
329 /************************************************************************
330 			NETGRAPH NODE STUFF
331  ************************************************************************/
332 
333 /*
334  * Constructor for a node
335  */
336 static int
337 ng_eiface_constructor(node_p node)
338 {
339 	INIT_VNET_NETGRAPH(curvnet);
340 	struct ifnet *ifp;
341 	priv_p priv;
342 	u_char eaddr[6] = {0,0,0,0,0,0};
343 
344 	/* Allocate node and interface private structures */
345 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
346 	if (priv == NULL)
347 		return (ENOMEM);
348 
349 	ifp = priv->ifp = if_alloc(IFT_ETHER);
350 	if (ifp == NULL) {
351 		free(priv, M_NETGRAPH);
352 		return (ENOSPC);
353 	}
354 
355 	/* Link them together */
356 	ifp->if_softc = priv;
357 
358 	/* Get an interface unit number */
359 	priv->unit = alloc_unr(V_ng_eiface_unit);
360 
361 	/* Link together node and private info */
362 	NG_NODE_SET_PRIVATE(node, priv);
363 	priv->node = node;
364 
365 	/* Initialize interface structure */
366 	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
367 	ifp->if_init = ng_eiface_init;
368 	ifp->if_output = ether_output;
369 	ifp->if_start = ng_eiface_start;
370 	ifp->if_ioctl = ng_eiface_ioctl;
371 	ifp->if_watchdog = NULL;
372 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
373 	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
374 
375 #if 0
376 	/* Give this node name */
377 	bzero(ifname, sizeof(ifname));
378 	sprintf(ifname, "if%s", ifp->if_xname);
379 	(void)ng_name_node(node, ifname);
380 #endif
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 
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 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
456 				buflen += SA_SIZE(ifa->ifa_addr);
457 			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
458 			if (resp == NULL) {
459 				error = ENOMEM;
460 				break;
461 			}
462 
463 			/* Add addresses */
464 			ptr = resp->data;
465 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
466 				const int len = SA_SIZE(ifa->ifa_addr);
467 
468 				if (buflen < len) {
469 					log(LOG_ERR, "%s: len changed?\n",
470 					    ifp->if_xname);
471 					break;
472 				}
473 				bcopy(ifa->ifa_addr, ptr, len);
474 				ptr += len;
475 				buflen -= len;
476 			}
477 			break;
478 		    }
479 
480 		default:
481 			error = EINVAL;
482 			break;
483 		} /* end of inner switch() */
484 		break;
485 	case NGM_FLOW_COOKIE:
486 		switch (msg->header.cmd) {
487 		case NGM_LINK_IS_UP:
488 			if_link_state_change(ifp, LINK_STATE_UP);
489 			break;
490 		case NGM_LINK_IS_DOWN:
491 			if_link_state_change(ifp, LINK_STATE_DOWN);
492 			break;
493 		default:
494 			break;
495 		}
496 		break;
497 	default:
498 		error = EINVAL;
499 		break;
500 	}
501 	NG_RESPOND_MSG(error, node, item, resp);
502 	NG_FREE_MSG(msg);
503 	return (error);
504 }
505 
506 /*
507  * Receive data from a hook. Pass the packet to the ether_input routine.
508  */
509 static int
510 ng_eiface_rcvdata(hook_p hook, item_p item)
511 {
512 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
513 	struct ifnet *const ifp = priv->ifp;
514 	struct mbuf *m;
515 
516 	NGI_GET_M(item, m);
517 	NG_FREE_ITEM(item);
518 
519 	if (!((ifp->if_flags & IFF_UP) &&
520 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
521 		NG_FREE_M(m);
522 		return (ENETDOWN);
523 	}
524 
525 	if (m->m_len < ETHER_HDR_LEN) {
526 		m = m_pullup(m, ETHER_HDR_LEN);
527 		if (m == NULL)
528 			return (EINVAL);
529 	}
530 
531 	/* Note receiving interface */
532 	m->m_pkthdr.rcvif = ifp;
533 
534 	/* Update interface stats */
535 	ifp->if_ipackets++;
536 
537 	(*ifp->if_input)(ifp, m);
538 
539 	/* Done */
540 	return (0);
541 }
542 
543 /*
544  * Shutdown processing.
545  */
546 static int
547 ng_eiface_rmnode(node_p node)
548 {
549 	INIT_VNET_NETGRAPH(curvnet);
550 	const priv_p priv = NG_NODE_PRIVATE(node);
551 	struct ifnet *const ifp = priv->ifp;
552 
553 	/*
554 	 * the ifnet may be in a different vnet than the netgraph node,
555 	 * hence we have to change the current vnet context here.
556 	 */
557 	CURVNET_SET_QUIET(ifp->if_vnet);
558 	ether_ifdetach(ifp);
559 	if_free(ifp);
560 	CURVNET_RESTORE();
561 	free_unr(V_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  */
571 static int
572 ng_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  */
583 static int
584 ng_eiface_mod_event(module_t mod, int event, void *data)
585 {
586 	int error = 0;
587 
588 	switch (event) {
589 	case MOD_LOAD:
590 		V_ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
591 		break;
592 	case MOD_UNLOAD:
593 		delete_unrhdr(V_ng_eiface_unit);
594 		break;
595 	default:
596 		error = EOPNOTSUPP;
597 		break;
598 	}
599 	return (error);
600 }
601