xref: /freebsd/sys/netgraph/ng_eiface.c (revision 84ee9401a3fc8d3c22424266f421a928989cd692) 
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 	ng_send_fn(priv->node, NULL, &ng_eiface_start2, ifp, 0);
281 }
282 
283 #ifdef DEBUG
284 /*
285  * Display an ioctl to the virtual interface
286  */
287 
288 static void
289 ng_eiface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
290 {
291 	char *str;
292 
293 	switch (command & IOC_DIRMASK) {
294 	case IOC_VOID:
295 		str = "IO";
296 		break;
297 	case IOC_OUT:
298 		str = "IOR";
299 		break;
300 	case IOC_IN:
301 		str = "IOW";
302 		break;
303 	case IOC_INOUT:
304 		str = "IORW";
305 		break;
306 	default:
307 		str = "IO??";
308 	}
309 	log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
310 	    ifp->if_xname,
311 	    str,
312 	    IOCGROUP(command),
313 	    command & 0xff,
314 	    IOCPARM_LEN(command));
315 }
316 #endif /* DEBUG */
317 
318 /************************************************************************
319 			NETGRAPH NODE STUFF
320  ************************************************************************/
321 
322 /*
323  * Constructor for a node
324  */
325 static int
326 ng_eiface_constructor(node_p node)
327 {
328 	struct ifnet *ifp;
329 	priv_p priv;
330 	u_char eaddr[6] = {0,0,0,0,0,0};
331 
332 	/* Allocate node and interface private structures */
333 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
334 	if (priv == NULL)
335 		return (ENOMEM);
336 
337 	ifp = priv->ifp = if_alloc(IFT_ETHER);
338 	if (ifp == NULL) {
339 		free(priv, M_NETGRAPH);
340 		return (ENOSPC);
341 	}
342 
343 	/* Link them together */
344 	ifp->if_softc = priv;
345 
346 	/* Get an interface unit number */
347 	priv->unit = alloc_unr(ng_eiface_unit);
348 
349 	/* Link together node and private info */
350 	NG_NODE_SET_PRIVATE(node, priv);
351 	priv->node = node;
352 
353 	/* Initialize interface structure */
354 	if_initname(ifp, NG_EIFACE_EIFACE_NAME, priv->unit);
355 	ifp->if_init = ng_eiface_init;
356 	ifp->if_output = ether_output;
357 	ifp->if_start = ng_eiface_start;
358 	ifp->if_ioctl = ng_eiface_ioctl;
359 	ifp->if_watchdog = NULL;
360 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
361 	ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
362 
363 #if 0
364 	/* Give this node name */
365 	bzero(ifname, sizeof(ifname));
366 	sprintf(ifname, "if%s", ifp->if_xname);
367 	(void)ng_name_node(node, ifname);
368 #endif
369 
370 	/* Attach the interface */
371 	ether_ifattach(ifp, eaddr);
372 
373 	/* Done */
374 	return (0);
375 }
376 
377 /*
378  * Give our ok for a hook to be added
379  */
380 static int
381 ng_eiface_newhook(node_p node, hook_p hook, const char *name)
382 {
383 	priv_p priv = NG_NODE_PRIVATE(node);
384 	struct ifnet *ifp = priv->ifp;
385 
386 	if (strcmp(name, NG_EIFACE_HOOK_ETHER))
387 		return (EPFNOSUPPORT);
388 	if (priv->ether != NULL)
389 		return (EISCONN);
390 	priv->ether = hook;
391 	NG_HOOK_SET_PRIVATE(hook, &priv->ether);
392 
393 	if_link_state_change(ifp, LINK_STATE_UP);
394 
395 	return (0);
396 }
397 
398 /*
399  * Receive a control message
400  */
401 static int
402 ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
403 {
404 	const priv_p priv = NG_NODE_PRIVATE(node);
405 	struct ifnet *const ifp = priv->ifp;
406 	struct ng_mesg *resp = NULL;
407 	int error = 0;
408 	struct ng_mesg *msg;
409 
410 	NGI_GET_MSG(item, msg);
411 	switch (msg->header.typecookie) {
412 	case NGM_EIFACE_COOKIE:
413 		switch (msg->header.cmd) {
414 
415 		case NGM_EIFACE_SET:
416 		    {
417 			if (msg->header.arglen != ETHER_ADDR_LEN) {
418 				error = EINVAL;
419 				break;
420 			}
421 			error = if_setlladdr(priv->ifp,
422 			    (u_char *)msg->data, ETHER_ADDR_LEN);
423 			break;
424 		    }
425 
426 		case NGM_EIFACE_GET_IFNAME:
427 			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
428 			if (resp == NULL) {
429 				error = ENOMEM;
430 				break;
431 			}
432 			strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
433 			break;
434 
435 		case NGM_EIFACE_GET_IFADDRS:
436 		    {
437 			struct ifaddr *ifa;
438 			caddr_t ptr;
439 			int buflen;
440 
441 #define SA_SIZE(s)	((s)->sa_len<sizeof(*(s))? sizeof(*(s)):(s)->sa_len)
442 
443 			/* Determine size of response and allocate it */
444 			buflen = 0;
445 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
446 				buflen += SA_SIZE(ifa->ifa_addr);
447 			NG_MKRESPONSE(resp, msg, buflen, M_NOWAIT);
448 			if (resp == NULL) {
449 				error = ENOMEM;
450 				break;
451 			}
452 
453 			/* Add addresses */
454 			ptr = resp->data;
455 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
456 				const int len = SA_SIZE(ifa->ifa_addr);
457 
458 				if (buflen < len) {
459 					log(LOG_ERR, "%s: len changed?\n",
460 					    ifp->if_xname);
461 					break;
462 				}
463 				bcopy(ifa->ifa_addr, ptr, len);
464 				ptr += len;
465 				buflen -= len;
466 			}
467 			break;
468 #undef SA_SIZE
469 		    }
470 
471 		default:
472 			error = EINVAL;
473 			break;
474 		} /* end of inner switch() */
475 		break;
476 	case NGM_FLOW_COOKIE:
477 		switch (msg->header.cmd) {
478 		case NGM_LINK_IS_UP:
479 			if_link_state_change(ifp, LINK_STATE_UP);
480 			break;
481 		case NGM_LINK_IS_DOWN:
482 			if_link_state_change(ifp, LINK_STATE_DOWN);
483 			break;
484 		default:
485 			break;
486 		}
487 		break;
488 	default:
489 		error = EINVAL;
490 		break;
491 	}
492 	NG_RESPOND_MSG(error, node, item, resp);
493 	NG_FREE_MSG(msg);
494 	return (error);
495 }
496 
497 /*
498  * Receive data from a hook. Pass the packet to the ether_input routine.
499  */
500 static int
501 ng_eiface_rcvdata(hook_p hook, item_p item)
502 {
503 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
504 	struct ifnet *const ifp = priv->ifp;
505 	struct mbuf *m;
506 
507 	NGI_GET_M(item, m);
508 	NG_FREE_ITEM(item);
509 
510 	if (!((ifp->if_flags & IFF_UP) &&
511 	    (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
512 		NG_FREE_M(m);
513 		return (ENETDOWN);
514 	}
515 
516 	if (m->m_len < ETHER_HDR_LEN) {
517 		m = m_pullup(m, ETHER_HDR_LEN);
518 		if (m == NULL)
519 			return (EINVAL);
520 	}
521 
522 	/* Note receiving interface */
523 	m->m_pkthdr.rcvif = ifp;
524 
525 	/* Update interface stats */
526 	ifp->if_ipackets++;
527 
528 	(*ifp->if_input)(ifp, m);
529 
530 	/* Done */
531 	return (0);
532 }
533 
534 /*
535  * Shutdown processing.
536  */
537 static int
538 ng_eiface_rmnode(node_p node)
539 {
540 	const priv_p priv = NG_NODE_PRIVATE(node);
541 	struct ifnet *const ifp = priv->ifp;
542 
543 	ether_ifdetach(ifp);
544 	if_free(ifp);
545 	free_unr(ng_eiface_unit, priv->unit);
546 	FREE(priv, M_NETGRAPH);
547 	NG_NODE_SET_PRIVATE(node, NULL);
548 	NG_NODE_UNREF(node);
549 	return (0);
550 }
551 
552 /*
553  * Hook disconnection
554  */
555 static int
556 ng_eiface_disconnect(hook_p hook)
557 {
558 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
559 
560 	priv->ether = NULL;
561 	return (0);
562 }
563 
564 /*
565  * Handle loading and unloading for this node type.
566  */
567 static int
568 ng_eiface_mod_event(module_t mod, int event, void *data)
569 {
570 	int error = 0;
571 
572 	switch (event) {
573 	case MOD_LOAD:
574 		ng_eiface_unit = new_unrhdr(0, 0xffff, NULL);
575 		break;
576 	case MOD_UNLOAD:
577 		delete_unrhdr(ng_eiface_unit);
578 		break;
579 	default:
580 		error = EOPNOTSUPP;
581 		break;
582 	}
583 	return (error);
584 }
585