xref: /freebsd/sys/netgraph/ng_eiface.c (revision bfe691b2f75de2224c7ceb304ebcdef2b42d4179) 
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 
42 #include <net/if.h>
43 #include <net/if_types.h>
44 #include <net/netisr.h>
45 
46 #include <netgraph/ng_message.h>
47 #include <netgraph/netgraph.h>
48 #include <netgraph/ng_parse.h>
49 #include <netgraph/ng_eiface.h>
50 
51 #include <net/bpf.h>
52 #include <net/ethernet.h>
53 #include <net/if_arp.h>
54 
55 static const struct ng_cmdlist ng_eiface_cmdlist[] = {
56 	{
57 	  NGM_EIFACE_COOKIE,
58 	  NGM_EIFACE_GET_IFNAME,
59 	  "getifname",
60 	  NULL,
61 	  &ng_parse_string_type
62 	},
63 	{
64 	  NGM_EIFACE_COOKIE,
65 	  NGM_EIFACE_SET,
66 	  "set",
67 	  &ng_parse_enaddr_type,
68 	  NULL
69 	},
70 	{ 0 }
71 };
72 
73 /* Node private data */
74 struct ng_eiface_private {
75 	struct ifnet	*ifp;		/* per-interface network data */
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 int		ng_eiface_mod_event(module_t, int, void *);
92 static ng_constructor_t	ng_eiface_constructor;
93 static ng_rcvmsg_t	ng_eiface_rcvmsg;
94 static ng_shutdown_t	ng_eiface_rmnode;
95 static ng_newhook_t	ng_eiface_newhook;
96 static ng_rcvdata_t	ng_eiface_rcvdata;
97 static ng_disconnect_t	ng_eiface_disconnect;
98 
99 /* Node type descriptor */
100 static struct ng_type typestruct = {
101 	.version =	NG_ABI_VERSION,
102 	.name =		NG_EIFACE_NODE_TYPE,
103 	.mod_event =	ng_eiface_mod_event,
104 	.constructor =	ng_eiface_constructor,
105 	.rcvmsg =	ng_eiface_rcvmsg,
106 	.shutdown =	ng_eiface_rmnode,
107 	.newhook =	ng_eiface_newhook,
108 	.rcvdata =	ng_eiface_rcvdata,
109 	.disconnect =	ng_eiface_disconnect,
110 	.cmdlist =	ng_eiface_cmdlist
111 };
112 NETGRAPH_INIT(eiface, &typestruct);
113 
114 static struct unrhdr	*ng_eiface_unit;
115 
116 /************************************************************************
117 			INTERFACE STUFF
118  ************************************************************************/
119 
120 /*
121  * Process an ioctl for the virtual interface
122  */
123 static int
124 ng_eiface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
125 {
126 	struct ifreq *const ifr = (struct ifreq *)data;
127 	int s, error = 0;
128 
129 #ifdef DEBUG
130 	ng_eiface_print_ioctl(ifp, command, data);
131 #endif
132 	s = splimp();
133 	switch (command) {
134 
135 	/* These two are mostly handled at a higher layer */
136 	case SIOCSIFADDR:
137 		error = ether_ioctl(ifp, command, data);
138 		break;
139 	case SIOCGIFADDR:
140 		break;
141 
142 	/* Set flags */
143 	case SIOCSIFFLAGS:
144 		/*
145 		 * If the interface is marked up and stopped, then start it.
146 		 * If it is marked down and running, then stop it.
147 		 */
148 		if (ifp->if_flags & IFF_UP) {
149 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
150 				ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
151 				ifp->if_drv_flags |= IFF_DRV_RUNNING;
152 			}
153 		} else {
154 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
155 				ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
156 				    IFF_DRV_OACTIVE);
157 		}
158 		break;
159 
160 	/* Set the interface MTU */
161 	case SIOCSIFMTU:
162 		if (ifr->ifr_mtu > NG_EIFACE_MTU_MAX ||
163 		    ifr->ifr_mtu < NG_EIFACE_MTU_MIN)
164 			error = EINVAL;
165 		else
166 			ifp->if_mtu = ifr->ifr_mtu;
167 		break;
168 
169 	/* Stuff that's not supported */
170 	case SIOCADDMULTI:
171 	case SIOCDELMULTI:
172 		error = 0;
173 		break;
174 	case SIOCSIFPHYS:
175 		error = EOPNOTSUPP;
176 		break;
177 
178 	default:
179 		error = EINVAL;
180 		break;
181 	}
182 	splx(s);
183 	return (error);
184 }
185 
186 static void
187 ng_eiface_init(void *xsc)
188 {
189 	priv_p sc = xsc;
190 	struct ifnet *ifp = sc->ifp;
191 	int s;
192 
193 	s = splimp();
194 
195 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
196 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
197 
198 	splx(s);
199 }
200 
201 /*
202  * We simply relay the packet to the "ether" hook, if it is connected.
203  * We have been through the netgraph locking and are guaranteed to
204  * be the only code running in this node at this time.
205  */
206 static void
207 ng_eiface_start2(node_p node, hook_p hook, void *arg1, int arg2)
208 {
209 	struct ifnet *ifp = arg1;
210 	const priv_p priv = (priv_p)ifp->if_softc;
211 	int error = 0;
212 	struct mbuf *m;
213 
214 	/* Check interface flags */
215 
216 	if (!((ifp->if_flags & IFF_UP) &&
217 	    (ifp->if_drv_flags & IFF_DRV_RUNNING)))
218 		return;
219 
220 	for (;;) {
221 		/*
222 		 * Grab a packet to transmit.
223 		 */
224 		IF_DEQUEUE(&ifp->if_snd, m);
225 
226 		/* If there's nothing to send, break. */
227 		if (m == NULL)
228 			break;
229 
230 		/*
231 		 * Berkeley packet filter.
232 		 * Pass packet to bpf if there is a listener.
233 		 * XXX is this safe? locking?
234 		 */
235 		BPF_MTAP(ifp, m);
236 
237 		/*
238 		 * Send packet; if hook is not connected, mbuf will get
239 		 * freed.
240 		 */
241 		NG_SEND_DATA_ONLY(error, priv->ether, m);
242 
243 		/* Update stats */
244 		if (error == 0)
245 			ifp->if_opackets++;
246 		else
247 			ifp->if_oerrors++;
248 	}
249 
250 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
251 
252 	return;
253 }
254 
255 /*
256  * This routine is called to deliver a packet out the interface.
257  * We simply queue the netgraph version to be called when netgraph locking
258  * allows it to happen.
259  * Until we know what the rest of the networking code is doing for
260  * locking, we don't know how we will interact with it.
261  * Take comfort from the fact that the ifnet struct is part of our
262  * private info and can't go away while we are queued.
263  * [Though we don't know it is still there now....]
264  * it is possible we don't gain anything from this because
265  * we would like to get the mbuf and queue it as data
266  * somehow, but we can't and if we did would we solve anything?
267  */
268 static void
269 ng_eiface_start(struct ifnet *ifp)
270 {
271 
272 	const priv_p priv = (priv_p)ifp->if_softc;
273 
274 	/* Don't do anything if output is active */
275 	if (ifp->if_drv_flags & IFF_DRV_OACTIVE)
276 		return;
277 
278 	ifp->if_drv_flags |= IFF_DRV_OACTIVE;
279 
280 	if (ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0) != 0)
281 		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
282 }
283 
284 #ifdef DEBUG
285 /*
286  * Display an ioctl to the virtual interface
287  */
288 
289 static void
290 ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
291 {
292 	char *str;
293 
294 	switch (command & IOC_DIRMASK) {
295 	case IOC_VOID:
296 		str = "IO";
297 		break;
298 	case IOC_OUT:
299 		str = "IOR";
300 		break;
301 	case IOC_IN:
302 		str = "IOW";
303 		break;
304 	case IOC_INOUT:
305 		str = "IORW";
306 		break;
307 	default:
308 		str = "IO??";
309 	}
310 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
311 	    ifp->if_xname,
312 	    str,
313 	    IOCGROUP(command),
314 	    command & 0xff,
315 	    IOCPARM_LEN(command));
316 }
317 #endif /* DEBUG */
318 
319 /************************************************************************
320 			NETGRAPH NODE STUFF
321  ************************************************************************/
322 
323 /*
324  * Constructor for a node
325  */
326 static int
327 ng_eiface_constructor(node_p node)
328 {
329 	struct ifnet *ifp;
330 	priv_p priv;
331 	u_char eaddr[6] = {0,0,0,0,0,0};
332 
333 	/* Allocate node and interface private structures */
334 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
335 	if (priv == NULL)
336 		return (ENOMEM);
337 
338 	ifp = priv->ifp = if_alloc(IFT_ETHER);
339 	if (ifp == NULL) {
340 		free(priv, M_NETGRAPH);
341 		return (ENOSPC);
342 	}
343 
344 	/* Link them together */
345 	ifp->if_softc = priv;
346 
347 	/* Get an interface unit number */
348 	priv->unit = alloc_unr(ng_eiface_unit);
349 
350 	/* Link together node and private info */
351 	NG_NODE_SET_PRIVATE(node, priv);
352 	priv->node = node;
353 
354 	/* Initialize interface structure */
355 	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
356 	ifp->if_init = ng_eiface_init;
357 	ifp->if_output = ether_output;
358 	ifp->if_start = ng_eiface_start;
359 	ifp->if_ioctl = ng_eiface_ioctl;
360 	ifp->if_watchdog = NULL;
361 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
362 	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
363 
364 #if 0
365 	/* Give this node name */
366 	bzero(ifname, sizeof(ifname));
367 	sprintf(ifname, "if%s", ifp->if_xname);
368 	(void)ng_name_node(node, ifname);
369 #endif
370 
371 	/* Attach the interface */
372 	ether_ifattach(ifp, eaddr);
373 
374 	/* Done */
375 	return (0);
376 }
377 
378 /*
379  * Give our ok for a hook to be added
380  */
381 static int
382 ng_eiface_newhook(node_p node, hook_p hook, const char *name)
383 {
384 	priv_p priv = NG_NODE_PRIVATE(node);
385 	struct ifnet *ifp = priv->ifp;
386 
387 	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
388 		return (EPFNOSUPPORT);
389 	if (priv->ether != NULL)
390 		return (EISCONN);
391 	priv->ether = hook;
392 	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
393 
394 	if_link_state_change(ifp, LINK_STATE_UP);
395 
396 	return (0);
397 }
398 
399 /*
400  * Receive a control message
401  */
402 static int
403 ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
404 {
405 	const priv_p priv = NG_NODE_PRIVATE(node);
406 	struct ifnet *const ifp = priv->ifp;
407 	struct ng_mesg *resp = NULL;
408 	int error = 0;
409 	struct ng_mesg *msg;
410 
411 	NGI_GET_MSG(item, msg);
412 	switch (msg->header.typecookie) {
413 	case NGM_EIFACE_COOKIE:
414 		switch (msg->header.cmd) {
415 
416 		case NGM_EIFACE_SET:
417 		    {
418 			if (msg->header.arglen != ETHER_ADDR_LEN) {
419 				error = EINVAL;
420 				break;
421 			}
422 			error = if_setlladdr(priv->ifp,
423 			    (u_char *)msg->data, ETHER_ADDR_LEN);
424 			break;
425 		    }
426 
427 		case NGM_EIFACE_GET_IFNAME:
428 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
429 			if (resp == NULL) {
430 				error = ENOMEM;
431 				break;
432 			}
433 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
434 			break;
435 
436 		case NGM_EIFACE_GET_IFADDRS:
437 		    {
438 			struct ifaddr *ifa;
439 			caddr_t ptr;
440 			int buflen;
441 
442 #define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
443 
444 			/* Determine size of response and allocate it */
445 			buflen = 0;
446 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
447 				buflen += SA_SIZE(ifa->ifa_addr);
448 			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
449 			if (resp == NULL) {
450 				error = ENOMEM;
451 				break;
452 			}
453 
454 			/* Add addresses */
455 			ptr = resp->data;
456 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
457 				const int len = SA_SIZE(ifa->ifa_addr);
458 
459 				if (buflen < len) {
460 					log(LOG_ERR, "%s: len changed?\n",
461 					    ifp->if_xname);
462 					break;
463 				}
464 				bcopy(ifa->ifa_addr, ptr, len);
465 				ptr += len;
466 				buflen -= len;
467 			}
468 			break;
469 #undef SA_SIZE
470 		    }
471 
472 		default:
473 			error = EINVAL;
474 			break;
475 		} /* end of inner switch() */
476 		break;
477 	case NGM_FLOW_COOKIE:
478 		switch (msg->header.cmd) {
479 		case NGM_LINK_IS_UP:
480 			if_link_state_change(ifp, LINK_STATE_UP);
481 			break;
482 		case NGM_LINK_IS_DOWN:
483 			if_link_state_change(ifp, LINK_STATE_DOWN);
484 			break;
485 		default:
486 			break;
487 		}
488 		break;
489 	default:
490 		error = EINVAL;
491 		break;
492 	}
493 	NG_RESPOND_MSG(error, node, item, resp);
494 	NG_FREE_MSG(msg);
495 	return (error);
496 }
497 
498 /*
499  * Receive data from a hook. Pass the packet to the ether_input routine.
500  */
501 static int
502 ng_eiface_rcvdata(hook_p hook, item_p item)
503 {
504 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
505 	struct ifnet *const ifp = priv->ifp;
506 	struct mbuf *m;
507 
508 	NGI_GET_M(item, m);
509 	NG_FREE_ITEM(item);
510 
511 	if (!((ifp->if_flags & IFF_UP) &&
512 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
513 		NG_FREE_M(m);
514 		return (ENETDOWN);
515 	}
516 
517 	if (m->m_len < ETHER_HDR_LEN) {
518 		m = m_pullup(m, ETHER_HDR_LEN);
519 		if (m == NULL)
520 			return (EINVAL);
521 	}
522 
523 	/* Note receiving interface */
524 	m->m_pkthdr.rcvif = ifp;
525 
526 	/* Update interface stats */
527 	ifp->if_ipackets++;
528 
529 	(*ifp->if_input)(ifp, m);
530 
531 	/* Done */
532 	return (0);
533 }
534 
535 /*
536  * Shutdown processing.
537  */
538 static int
539 ng_eiface_rmnode(node_p node)
540 {
541 	const priv_p priv = NG_NODE_PRIVATE(node);
542 	struct ifnet *const ifp = priv->ifp;
543 
544 	ether_ifdetach(ifp);
545 	if_free(ifp);
546 	free_unr(ng_eiface_unit, priv->unit);
547 	FREE(priv, M_NETGRAPH);
548 	NG_NODE_SET_PRIVATE(node, NULL);
549 	NG_NODE_UNREF(node);
550 	return (0);
551 }
552 
553 /*
554  * Hook disconnection
555  */
556 static int
557 ng_eiface_disconnect(hook_p hook)
558 {
559 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
560 
561 	priv->ether = NULL;
562 	return (0);
563 }
564 
565 /*
566  * Handle loading and unloading for this node type.
567  */
568 static int
569 ng_eiface_mod_event(module_t mod, int event, void *data)
570 {
571 	int error = 0;
572 
573 	switch (event) {
574 	case MOD_LOAD:
575 		ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
576 		break;
577 	case MOD_UNLOAD:
578 		delete_unrhdr(ng_eiface_unit);
579 		break;
580 	default:
581 		error = EOPNOTSUPP;
582 		break;
583 	}
584 	return (error);
585 }
586