xref: /netbsd-src/sys/net/link_proto.c (revision d909946ca08dceb44d7d0f22ec9488679695d976)
1 /*	$NetBSD: link_proto.c,v 1.31 2016/07/07 09:32:02 ozaki-r Exp $	*/
2 
3 /*-
4  * Copyright (c) 1982, 1986, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following 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  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)uipc_proto.c	8.2 (Berkeley) 2/14/95
32  */
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: link_proto.c,v 1.31 2016/07/07 09:32:02 ozaki-r Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/socket.h>
39 #include <sys/protosw.h>
40 #include <sys/domain.h>
41 #include <sys/mbuf.h>
42 #include <sys/un.h>
43 #include <sys/socketvar.h>
44 
45 #include <net/if.h>
46 #include <net/if_dl.h>
47 #include <net/raw_cb.h>
48 #include <net/route.h>
49 
50 static int sockaddr_dl_cmp(const struct sockaddr *, const struct sockaddr *);
51 static int link_attach(struct socket *, int);
52 static void link_detach(struct socket *);
53 static int link_accept(struct socket *, struct sockaddr *);
54 static int link_bind(struct socket *, struct sockaddr *, struct lwp *);
55 static int link_listen(struct socket *, struct lwp *);
56 static int link_connect(struct socket *, struct sockaddr *, struct lwp *);
57 static int link_connect2(struct socket *, struct socket *);
58 static int link_disconnect(struct socket *);
59 static int link_shutdown(struct socket *);
60 static int link_abort(struct socket *);
61 static int link_ioctl(struct socket *, u_long, void *, struct ifnet *);
62 static int link_stat(struct socket *, struct stat *);
63 static int link_peeraddr(struct socket *, struct sockaddr *);
64 static int link_sockaddr(struct socket *, struct sockaddr *);
65 static int link_rcvd(struct socket *, int, struct lwp *);
66 static int link_recvoob(struct socket *, struct mbuf *, int);
67 static int link_send(struct socket *, struct mbuf *, struct sockaddr *,
68     struct mbuf *, struct lwp *);
69 static int link_sendoob(struct socket *, struct mbuf *, struct mbuf *);
70 static int link_purgeif(struct socket *, struct ifnet *);
71 static void link_init(void);
72 
73 /*
74  * Definitions of protocols supported in the link-layer domain.
75  */
76 
77 DOMAIN_DEFINE(linkdomain);	/* forward define and add to link set */
78 
79 static const struct pr_usrreqs link_usrreqs = {
80 	.pr_attach	= link_attach,
81 	.pr_detach	= link_detach,
82 	.pr_accept	= link_accept,
83 	.pr_bind	= link_bind,
84 	.pr_listen	= link_listen,
85 	.pr_connect	= link_connect,
86 	.pr_connect2	= link_connect2,
87 	.pr_disconnect	= link_disconnect,
88 	.pr_shutdown	= link_shutdown,
89 	.pr_abort	= link_abort,
90 	.pr_ioctl	= link_ioctl,
91 	.pr_stat	= link_stat,
92 	.pr_peeraddr	= link_peeraddr,
93 	.pr_sockaddr	= link_sockaddr,
94 	.pr_rcvd	= link_rcvd,
95 	.pr_recvoob	= link_recvoob,
96 	.pr_send	= link_send,
97 	.pr_sendoob	= link_sendoob,
98 	.pr_purgeif	= link_purgeif,
99 };
100 
101 const struct protosw linksw[] = {
102 	{	.pr_type = SOCK_DGRAM,
103 		.pr_domain = &linkdomain,
104 		.pr_protocol = 0,	/* XXX */
105 		.pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
106 		.pr_input = NULL,
107 		.pr_ctlinput = NULL,
108 		.pr_ctloutput = NULL,
109 		.pr_usrreqs = &link_usrreqs,
110 		.pr_init = link_init,
111 	},
112 };
113 
114 struct domain linkdomain = {
115 	.dom_family = AF_LINK,
116 	.dom_name = "link",
117 	.dom_externalize = NULL,
118 	.dom_dispose = NULL,
119 	.dom_protosw = linksw,
120 	.dom_protoswNPROTOSW = &linksw[__arraycount(linksw)],
121 	.dom_sockaddr_cmp = sockaddr_dl_cmp
122 };
123 
124 static void
125 link_init(void)
126 {
127 	return;
128 }
129 
130 static int
131 link_control(struct socket *so, unsigned long cmd, void *data,
132     struct ifnet *ifp)
133 {
134 	int error, s;
135 	bool isactive, mkactive;
136 	struct if_laddrreq *iflr;
137 	union {
138 		struct sockaddr sa;
139 		struct sockaddr_dl sdl;
140 		struct sockaddr_storage ss;
141 	} u;
142 	struct ifaddr *ifa;
143 	const struct sockaddr_dl *asdl, *nsdl;
144 
145 	switch (cmd) {
146 	case SIOCALIFADDR:
147 	case SIOCDLIFADDR:
148 	case SIOCGLIFADDR:
149 		iflr = data;
150 
151 		if (iflr->addr.ss_family != AF_LINK)
152 			return EINVAL;
153 
154 		asdl = satocsdl(sstocsa(&iflr->addr));
155 
156 		if (asdl->sdl_alen != ifp->if_addrlen)
157 			return EINVAL;
158 
159 		if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), ifp->if_index,
160 		    ifp->if_type, ifp->if_xname, strlen(ifp->if_xname),
161 		    CLLADDR(asdl), asdl->sdl_alen) == NULL)
162 			return EINVAL;
163 
164 		if ((iflr->flags & IFLR_PREFIX) == 0)
165 			;
166 		else if (iflr->prefixlen != NBBY * ifp->if_addrlen)
167 			return EINVAL;	/* XXX match with prefix */
168 
169 		error = 0;
170 
171 		s = splnet();
172 
173 		IFADDR_READER_FOREACH(ifa, ifp) {
174 			if (sockaddr_cmp(&u.sa, ifa->ifa_addr) == 0)
175 				break;
176 		}
177 
178 		switch (cmd) {
179 		case SIOCGLIFADDR:
180 			if ((iflr->flags & IFLR_PREFIX) == 0) {
181 				IFADDR_READER_FOREACH(ifa, ifp) {
182 					if (ifa->ifa_addr->sa_family == AF_LINK)
183 						break;
184 				}
185 			}
186 			if (ifa == NULL) {
187 				error = EADDRNOTAVAIL;
188 				break;
189 			}
190 
191 			if (ifa == ifp->if_dl)
192 				iflr->flags = IFLR_ACTIVE;
193 			else
194 				iflr->flags = 0;
195 
196 			if (ifa == ifp->if_hwdl)
197 				iflr->flags |= IFLR_FACTORY;
198 
199 			sockaddr_copy(sstosa(&iflr->addr), sizeof(iflr->addr),
200 			    ifa->ifa_addr);
201 
202 			break;
203 		case SIOCDLIFADDR:
204 			if (ifa == NULL)
205 				error = EADDRNOTAVAIL;
206 			else if (ifa == ifp->if_dl || ifa == ifp->if_hwdl)
207 				error = EBUSY;
208 			else {
209 				/* TBD routing socket */
210 				rt_newaddrmsg(RTM_DELETE, ifa, 0, NULL);
211 				ifa_remove(ifp, ifa);
212 			}
213 			break;
214 		case SIOCALIFADDR:
215 			if (ifa != NULL)
216 				;
217 			else if ((ifa = if_dl_create(ifp, &nsdl)) == NULL) {
218 				error = ENOMEM;
219 				break;
220 			} else {
221 				sockaddr_copy(ifa->ifa_addr,
222 				    ifa->ifa_addr->sa_len, &u.sa);
223 				ifa_insert(ifp, ifa);
224 				rt_newaddrmsg(RTM_ADD, ifa, 0, NULL);
225 			}
226 
227 			mkactive = (iflr->flags & IFLR_ACTIVE) != 0;
228 			isactive = (ifa == ifp->if_dl);
229 
230 			if (!isactive && mkactive) {
231 				if_activate_sadl(ifp, ifa, nsdl);
232 				rt_newaddrmsg(RTM_CHANGE, ifa, 0, NULL);
233 				error = ENETRESET;
234 			}
235 			break;
236 		}
237 		splx(s);
238 		if (error != ENETRESET)
239 			return error;
240 		else if ((ifp->if_flags & IFF_RUNNING) != 0 &&
241 		         ifp->if_init != NULL)
242 			return (*ifp->if_init)(ifp);
243 		else
244 			return 0;
245 	default:
246 		return ENOTTY;
247 	}
248 }
249 
250 static int
251 link_attach(struct socket *so, int proto)
252 {
253 	sosetlock(so);
254 	KASSERT(solocked(so));
255 	return 0;
256 }
257 
258 static void
259 link_detach(struct socket *so)
260 {
261 	KASSERT(solocked(so));
262 	sofree(so);
263 }
264 
265 static int
266 link_accept(struct socket *so, struct sockaddr *nam)
267 {
268 	KASSERT(solocked(so));
269 
270 	return EOPNOTSUPP;
271 }
272 
273 static int
274 link_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
275 {
276 	KASSERT(solocked(so));
277 
278 	return EOPNOTSUPP;
279 }
280 
281 static int
282 link_listen(struct socket *so, struct lwp *l)
283 {
284 	KASSERT(solocked(so));
285 
286 	return EOPNOTSUPP;
287 }
288 
289 static int
290 link_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
291 {
292  	KASSERT(solocked(so));
293 
294 	return EOPNOTSUPP;
295 }
296 
297 static int
298 link_connect2(struct socket *so, struct socket *so2)
299 {
300  	KASSERT(solocked(so));
301 
302 	return EOPNOTSUPP;
303 }
304 
305 static int
306 link_disconnect(struct socket *so)
307 {
308 	KASSERT(solocked(so));
309 
310 	return EOPNOTSUPP;
311 }
312 
313 static int
314 link_shutdown(struct socket *so)
315 {
316 	KASSERT(solocked(so));
317 
318 	return EOPNOTSUPP;
319 }
320 
321 static int
322 link_abort(struct socket *so)
323 {
324 	KASSERT(solocked(so));
325 
326 	return EOPNOTSUPP;
327 }
328 
329 static int
330 link_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
331 {
332 	return link_control(so, cmd, nam, ifp);
333 }
334 
335 static int
336 link_stat(struct socket *so, struct stat *ub)
337 {
338 	KASSERT(solocked(so));
339 
340 	return EOPNOTSUPP;
341 }
342 
343 static int
344 link_peeraddr(struct socket *so, struct sockaddr *nam)
345 {
346 	KASSERT(solocked(so));
347 
348 	return EOPNOTSUPP;
349 }
350 
351 static int
352 link_sockaddr(struct socket *so, struct sockaddr *nam)
353 {
354  	KASSERT(solocked(so));
355 
356 	return EOPNOTSUPP;
357 }
358 
359 static int
360 link_rcvd(struct socket *so, int flags, struct lwp *l)
361 {
362 	KASSERT(solocked(so));
363 
364 	return EOPNOTSUPP;
365 }
366 
367 static int
368 link_recvoob(struct socket *so, struct mbuf *m, int flags)
369 {
370 	KASSERT(solocked(so));
371 
372 	return EOPNOTSUPP;
373 }
374 
375 static int
376 link_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
377     struct mbuf *control, struct lwp *l)
378 {
379 	KASSERT(solocked(so));
380 
381 	return EOPNOTSUPP;
382 }
383 
384 static int
385 link_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
386 {
387 	KASSERT(solocked(so));
388 
389 	return EOPNOTSUPP;
390 }
391 
392 static int
393 link_purgeif(struct socket *so, struct ifnet *ifp)
394 {
395 
396 	return EOPNOTSUPP;
397 }
398 
399 /* Compare the field at byte offsets [fieldstart, fieldend) in
400  * two memory regions, [l, l + llen) and [r, r + llen).
401  */
402 static inline int
403 submemcmp(const void *l, const void *r,
404     const uint_fast8_t llen, const uint_fast8_t rlen,
405     const uint_fast8_t fieldstart, const uint_fast8_t fieldend)
406 {
407 	uint_fast8_t cmpend, minlen;
408 	const uint8_t *lb = l, *rb = r;
409 	int rc;
410 
411 	minlen = MIN(llen, rlen);
412 
413 	/* The field is missing from one region.  The shorter region is the
414 	 * lesser region.
415 	 */
416 	if (fieldstart >= minlen)
417 		return llen - rlen;
418 
419 	/* Two empty, present fields are always equal. */
420 	if (fieldstart > fieldend)
421 		return 0;
422 
423 	cmpend = MIN(fieldend, minlen);
424 
425 	rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart);
426 
427 	if (rc != 0)
428 		return rc;
429 	/* If one or both fields are truncated, then the shorter is the lesser
430 	 * field.
431 	 */
432 	if (minlen < fieldend)
433 		return llen - rlen;
434 	/* Fields are full-length and equal.  The fields are equal. */
435 	return 0;
436 }
437 
438 uint8_t
439 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen)
440 {
441 	return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]);
442 }
443 
444 struct sockaddr *
445 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type,
446     const void *name, uint8_t namelen, const void *addr, uint8_t addrlen,
447     int flags)
448 {
449 	struct sockaddr *sa;
450 	socklen_t len;
451 
452 	len = sockaddr_dl_measure(namelen, addrlen);
453 	sa = sockaddr_alloc(AF_LINK, len, flags);
454 
455 	if (sa == NULL)
456 		return NULL;
457 
458 	if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen,
459 	    addr, addrlen) == NULL) {
460 		sockaddr_free(sa);
461 		return NULL;
462 	}
463 
464 	return sa;
465 }
466 
467 struct sockaddr_dl *
468 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex,
469     uint8_t type, const void *name, uint8_t namelen, const void *addr,
470     uint8_t addrlen)
471 {
472 	socklen_t len;
473 
474 	sdl->sdl_family = AF_LINK;
475 	sdl->sdl_slen = 0;
476 	len = sockaddr_dl_measure(namelen, addrlen);
477 	if (len > socklen) {
478 		sdl->sdl_len = socklen;
479 #ifdef DIAGNOSTIC
480 		printf("%s: too long: %u > %u\n", __func__, (u_int)len,
481 		    (u_int)socklen);
482 #endif
483 		return NULL;
484 	}
485 	sdl->sdl_len = len;
486 	sdl->sdl_index = ifindex;
487 	sdl->sdl_type = type;
488 	memset(&sdl->sdl_data[0], 0, namelen + addrlen);
489 	if (name != NULL) {
490 		memcpy(&sdl->sdl_data[0], name, namelen);
491 		sdl->sdl_nlen = namelen;
492 	} else
493 		sdl->sdl_nlen = 0;
494 	if (addr != NULL) {
495 		memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
496 		sdl->sdl_alen = addrlen;
497 	} else
498 		sdl->sdl_alen = 0;
499 	return sdl;
500 }
501 
502 static int
503 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
504 {
505 	int rc;
506 	const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index);
507 	const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen);
508 	uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]);
509 	const struct sockaddr_dl *sdl1, *sdl2;
510 
511 	sdl1 = satocsdl(sa1);
512 	sdl2 = satocsdl(sa2);
513 
514 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
515 	    indexofs, nlenofs);
516 
517 	if (rc != 0)
518 		return rc;
519 
520 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
521 	    dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen));
522 
523 	if (rc != 0)
524 		return rc;
525 
526 	if (sdl1->sdl_nlen != sdl2->sdl_nlen)
527 		return sdl1->sdl_nlen - sdl2->sdl_nlen;
528 
529 	dataofs += sdl1->sdl_nlen;
530 
531 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
532 	    dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen));
533 
534 	if (rc != 0)
535 		return rc;
536 
537 	if (sdl1->sdl_alen != sdl2->sdl_alen)
538 		return sdl1->sdl_alen - sdl2->sdl_alen;
539 
540 	dataofs += sdl1->sdl_alen;
541 
542 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
543 	    dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen));
544 
545 	if (sdl1->sdl_slen != sdl2->sdl_slen)
546 		return sdl1->sdl_slen - sdl2->sdl_slen;
547 
548 	return sdl1->sdl_len - sdl2->sdl_len;
549 }
550 
551 struct sockaddr_dl *
552 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen,
553     const void *addr, uint8_t addrlen)
554 {
555 	socklen_t len;
556 
557 	len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen);
558 	if (len > socklen) {
559 #ifdef DIAGNOSTIC
560 		printf("%s: too long: %u > %u\n", __func__, (u_int)len,
561 		    (u_int)socklen);
562 #endif
563 		return NULL;
564 	}
565 	memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
566 	sdl->sdl_alen = addrlen;
567 	sdl->sdl_len = len;
568 	return sdl;
569 }
570