xref: /netbsd-src/sys/net/link_proto.c (revision c34236556bea94afcaca1782d7d228301edc3ea0)
1 /*	$NetBSD: link_proto.c,v 1.33 2016/12/26 07:25:00 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 1.33 2016/12/26 07:25:00 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 	struct psref psref;
145 
146 	switch (cmd) {
147 	case SIOCALIFADDR:
148 	case SIOCDLIFADDR:
149 	case SIOCGLIFADDR:
150 		iflr = data;
151 
152 		if (iflr->addr.ss_family != AF_LINK)
153 			return EINVAL;
154 
155 		asdl = satocsdl(sstocsa(&iflr->addr));
156 
157 		if (asdl->sdl_alen != ifp->if_addrlen)
158 			return EINVAL;
159 
160 		if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), ifp->if_index,
161 		    ifp->if_type, ifp->if_xname, strlen(ifp->if_xname),
162 		    CLLADDR(asdl), asdl->sdl_alen) == NULL)
163 			return EINVAL;
164 
165 		if ((iflr->flags & IFLR_PREFIX) == 0)
166 			;
167 		else if (iflr->prefixlen != NBBY * ifp->if_addrlen)
168 			return EINVAL;	/* XXX match with prefix */
169 
170 		error = 0;
171 
172 		s = pserialize_read_enter();
173 		IFADDR_READER_FOREACH(ifa, ifp) {
174 			if (sockaddr_cmp(&u.sa, ifa->ifa_addr) == 0) {
175 				ifa_acquire(ifa, &psref);
176 				break;
177 			}
178 		}
179 		pserialize_read_exit(s);
180 
181 		switch (cmd) {
182 		case SIOCGLIFADDR:
183 			ifa_release(ifa, &psref);
184 			s = pserialize_read_enter();
185 			if ((iflr->flags & IFLR_PREFIX) == 0) {
186 				IFADDR_READER_FOREACH(ifa, ifp) {
187 					if (ifa->ifa_addr->sa_family == AF_LINK)
188 						break;
189 				}
190 			}
191 			if (ifa == NULL) {
192 				pserialize_read_exit(s);
193 				error = EADDRNOTAVAIL;
194 				break;
195 			}
196 
197 			if (ifa == ifp->if_dl)
198 				iflr->flags = IFLR_ACTIVE;
199 			else
200 				iflr->flags = 0;
201 
202 			if (ifa == ifp->if_hwdl)
203 				iflr->flags |= IFLR_FACTORY;
204 
205 			sockaddr_copy(sstosa(&iflr->addr), sizeof(iflr->addr),
206 			    ifa->ifa_addr);
207 			pserialize_read_exit(s);
208 			ifa = NULL;
209 
210 			break;
211 		case SIOCDLIFADDR:
212 			if (ifa == NULL)
213 				error = EADDRNOTAVAIL;
214 			else if (ifa == ifp->if_dl || ifa == ifp->if_hwdl)
215 				error = EBUSY;
216 			else {
217 				/* TBD routing socket */
218 				rt_newaddrmsg(RTM_DELETE, ifa, 0, NULL);
219 				ifa_remove(ifp, ifa);
220 			}
221 			break;
222 		case SIOCALIFADDR:
223 			if (ifa == NULL) {
224 				ifa = if_dl_create(ifp, &nsdl);
225 				if (ifa == NULL) {
226 					error = ENOMEM;
227 					break;
228 				}
229 				ifa_acquire(ifa, &psref);
230 				sockaddr_copy(ifa->ifa_addr,
231 				    ifa->ifa_addr->sa_len, &u.sa);
232 				ifa_insert(ifp, ifa);
233 				rt_newaddrmsg(RTM_ADD, ifa, 0, NULL);
234 			}
235 
236 			mkactive = (iflr->flags & IFLR_ACTIVE) != 0;
237 			isactive = (ifa == ifp->if_dl);
238 
239 			if (!isactive && mkactive) {
240 				if_activate_sadl(ifp, ifa, nsdl);
241 				rt_newaddrmsg(RTM_CHANGE, ifa, 0, NULL);
242 				error = ENETRESET;
243 			}
244 			break;
245 		}
246 		ifa_release(ifa, &psref);
247 		if (error != ENETRESET)
248 			return error;
249 		else if ((ifp->if_flags & IFF_RUNNING) != 0 &&
250 		         ifp->if_init != NULL)
251 			return (*ifp->if_init)(ifp);
252 		else
253 			return 0;
254 	default:
255 		return ENOTTY;
256 	}
257 }
258 
259 static int
260 link_attach(struct socket *so, int proto)
261 {
262 	sosetlock(so);
263 	KASSERT(solocked(so));
264 	return 0;
265 }
266 
267 static void
268 link_detach(struct socket *so)
269 {
270 	KASSERT(solocked(so));
271 	sofree(so);
272 }
273 
274 static int
275 link_accept(struct socket *so, struct sockaddr *nam)
276 {
277 	KASSERT(solocked(so));
278 
279 	return EOPNOTSUPP;
280 }
281 
282 static int
283 link_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
284 {
285 	KASSERT(solocked(so));
286 
287 	return EOPNOTSUPP;
288 }
289 
290 static int
291 link_listen(struct socket *so, struct lwp *l)
292 {
293 	KASSERT(solocked(so));
294 
295 	return EOPNOTSUPP;
296 }
297 
298 static int
299 link_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
300 {
301  	KASSERT(solocked(so));
302 
303 	return EOPNOTSUPP;
304 }
305 
306 static int
307 link_connect2(struct socket *so, struct socket *so2)
308 {
309  	KASSERT(solocked(so));
310 
311 	return EOPNOTSUPP;
312 }
313 
314 static int
315 link_disconnect(struct socket *so)
316 {
317 	KASSERT(solocked(so));
318 
319 	return EOPNOTSUPP;
320 }
321 
322 static int
323 link_shutdown(struct socket *so)
324 {
325 	KASSERT(solocked(so));
326 
327 	return EOPNOTSUPP;
328 }
329 
330 static int
331 link_abort(struct socket *so)
332 {
333 	KASSERT(solocked(so));
334 
335 	return EOPNOTSUPP;
336 }
337 
338 static int
339 link_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
340 {
341 	return link_control(so, cmd, nam, ifp);
342 }
343 
344 static int
345 link_stat(struct socket *so, struct stat *ub)
346 {
347 	KASSERT(solocked(so));
348 
349 	return 0;
350 }
351 
352 static int
353 link_peeraddr(struct socket *so, struct sockaddr *nam)
354 {
355 	KASSERT(solocked(so));
356 
357 	return EOPNOTSUPP;
358 }
359 
360 static int
361 link_sockaddr(struct socket *so, struct sockaddr *nam)
362 {
363  	KASSERT(solocked(so));
364 
365 	return EOPNOTSUPP;
366 }
367 
368 static int
369 link_rcvd(struct socket *so, int flags, struct lwp *l)
370 {
371 	KASSERT(solocked(so));
372 
373 	return EOPNOTSUPP;
374 }
375 
376 static int
377 link_recvoob(struct socket *so, struct mbuf *m, int flags)
378 {
379 	KASSERT(solocked(so));
380 
381 	return EOPNOTSUPP;
382 }
383 
384 static int
385 link_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
386     struct mbuf *control, struct lwp *l)
387 {
388 	KASSERT(solocked(so));
389 
390 	return EOPNOTSUPP;
391 }
392 
393 static int
394 link_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
395 {
396 	KASSERT(solocked(so));
397 
398 	return EOPNOTSUPP;
399 }
400 
401 static int
402 link_purgeif(struct socket *so, struct ifnet *ifp)
403 {
404 
405 	return EOPNOTSUPP;
406 }
407 
408 /* Compare the field at byte offsets [fieldstart, fieldend) in
409  * two memory regions, [l, l + llen) and [r, r + llen).
410  */
411 static inline int
412 submemcmp(const void *l, const void *r,
413     const uint_fast8_t llen, const uint_fast8_t rlen,
414     const uint_fast8_t fieldstart, const uint_fast8_t fieldend)
415 {
416 	uint_fast8_t cmpend, minlen;
417 	const uint8_t *lb = l, *rb = r;
418 	int rc;
419 
420 	minlen = MIN(llen, rlen);
421 
422 	/* The field is missing from one region.  The shorter region is the
423 	 * lesser region.
424 	 */
425 	if (fieldstart >= minlen)
426 		return llen - rlen;
427 
428 	/* Two empty, present fields are always equal. */
429 	if (fieldstart > fieldend)
430 		return 0;
431 
432 	cmpend = MIN(fieldend, minlen);
433 
434 	rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart);
435 
436 	if (rc != 0)
437 		return rc;
438 	/* If one or both fields are truncated, then the shorter is the lesser
439 	 * field.
440 	 */
441 	if (minlen < fieldend)
442 		return llen - rlen;
443 	/* Fields are full-length and equal.  The fields are equal. */
444 	return 0;
445 }
446 
447 uint8_t
448 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen)
449 {
450 	return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]);
451 }
452 
453 struct sockaddr *
454 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type,
455     const void *name, uint8_t namelen, const void *addr, uint8_t addrlen,
456     int flags)
457 {
458 	struct sockaddr *sa;
459 	socklen_t len;
460 
461 	len = sockaddr_dl_measure(namelen, addrlen);
462 	sa = sockaddr_alloc(AF_LINK, len, flags);
463 
464 	if (sa == NULL)
465 		return NULL;
466 
467 	if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen,
468 	    addr, addrlen) == NULL) {
469 		sockaddr_free(sa);
470 		return NULL;
471 	}
472 
473 	return sa;
474 }
475 
476 struct sockaddr_dl *
477 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex,
478     uint8_t type, const void *name, uint8_t namelen, const void *addr,
479     uint8_t addrlen)
480 {
481 	socklen_t len;
482 
483 	sdl->sdl_family = AF_LINK;
484 	sdl->sdl_slen = 0;
485 	len = sockaddr_dl_measure(namelen, addrlen);
486 	if (len > socklen) {
487 		sdl->sdl_len = socklen;
488 #ifdef DIAGNOSTIC
489 		printf("%s: too long: %u > %u\n", __func__, (u_int)len,
490 		    (u_int)socklen);
491 #endif
492 		return NULL;
493 	}
494 	sdl->sdl_len = len;
495 	sdl->sdl_index = ifindex;
496 	sdl->sdl_type = type;
497 	memset(&sdl->sdl_data[0], 0, namelen + addrlen);
498 	if (name != NULL) {
499 		memcpy(&sdl->sdl_data[0], name, namelen);
500 		sdl->sdl_nlen = namelen;
501 	} else
502 		sdl->sdl_nlen = 0;
503 	if (addr != NULL) {
504 		memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
505 		sdl->sdl_alen = addrlen;
506 	} else
507 		sdl->sdl_alen = 0;
508 	return sdl;
509 }
510 
511 static int
512 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
513 {
514 	int rc;
515 	const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index);
516 	const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen);
517 	uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]);
518 	const struct sockaddr_dl *sdl1, *sdl2;
519 
520 	sdl1 = satocsdl(sa1);
521 	sdl2 = satocsdl(sa2);
522 
523 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
524 	    indexofs, nlenofs);
525 
526 	if (rc != 0)
527 		return rc;
528 
529 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
530 	    dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen));
531 
532 	if (rc != 0)
533 		return rc;
534 
535 	if (sdl1->sdl_nlen != sdl2->sdl_nlen)
536 		return sdl1->sdl_nlen - sdl2->sdl_nlen;
537 
538 	dataofs += sdl1->sdl_nlen;
539 
540 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
541 	    dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen));
542 
543 	if (rc != 0)
544 		return rc;
545 
546 	if (sdl1->sdl_alen != sdl2->sdl_alen)
547 		return sdl1->sdl_alen - sdl2->sdl_alen;
548 
549 	dataofs += sdl1->sdl_alen;
550 
551 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
552 	    dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen));
553 
554 	if (sdl1->sdl_slen != sdl2->sdl_slen)
555 		return sdl1->sdl_slen - sdl2->sdl_slen;
556 
557 	return sdl1->sdl_len - sdl2->sdl_len;
558 }
559 
560 struct sockaddr_dl *
561 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen,
562     const void *addr, uint8_t addrlen)
563 {
564 	socklen_t len;
565 
566 	len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen);
567 	if (len > socklen) {
568 #ifdef DIAGNOSTIC
569 		printf("%s: too long: %u > %u\n", __func__, (u_int)len,
570 		    (u_int)socklen);
571 #endif
572 		return NULL;
573 	}
574 	memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
575 	sdl->sdl_alen = addrlen;
576 	sdl->sdl_len = len;
577 	return sdl;
578 }
579