xref: /netbsd-src/sys/net/link_proto.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: link_proto.c,v 1.36 2017/04/06 03:55:00 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 1.36 2017/04/06 03:55:00 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 				/* We need to release psref for ifa_remove */
220 				ifaref(ifa);
221 				ifa_release(ifa, &psref);
222 				ifa_remove(ifp, ifa);
223 				KASSERT(ifa->ifa_refcnt == 1);
224 				ifafree(ifa);
225 				ifa = NULL;
226 			}
227 			break;
228 		case SIOCALIFADDR:
229 			if (ifa == NULL) {
230 				ifa = if_dl_create(ifp, &nsdl);
231 				if (ifa == NULL) {
232 					error = ENOMEM;
233 					break;
234 				}
235 				ifa_acquire(ifa, &psref);
236 				sockaddr_copy(ifa->ifa_addr,
237 				    ifa->ifa_addr->sa_len, &u.sa);
238 				ifa_insert(ifp, ifa);
239 				rt_newaddrmsg(RTM_ADD, ifa, 0, NULL);
240 			}
241 
242 			mkactive = (iflr->flags & IFLR_ACTIVE) != 0;
243 			isactive = (ifa == ifp->if_dl);
244 
245 			if (!isactive && mkactive) {
246 				if_activate_sadl(ifp, ifa, nsdl);
247 				rt_newaddrmsg(RTM_CHANGE, ifa, 0, NULL);
248 				error = ENETRESET;
249 			}
250 			break;
251 		}
252 		ifa_release(ifa, &psref);
253 		if (error != ENETRESET)
254 			return error;
255 		else if ((ifp->if_flags & IFF_RUNNING) != 0 &&
256 		         ifp->if_init != NULL)
257 			return (*ifp->if_init)(ifp);
258 		else
259 			return 0;
260 	default:
261 		return ENOTTY;
262 	}
263 }
264 
265 static int
266 link_attach(struct socket *so, int proto)
267 {
268 	sosetlock(so);
269 	KASSERT(solocked(so));
270 	return 0;
271 }
272 
273 static void
274 link_detach(struct socket *so)
275 {
276 	KASSERT(solocked(so));
277 	sofree(so);
278 }
279 
280 static int
281 link_accept(struct socket *so, struct sockaddr *nam)
282 {
283 	KASSERT(solocked(so));
284 
285 	return EOPNOTSUPP;
286 }
287 
288 static int
289 link_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
290 {
291 	KASSERT(solocked(so));
292 
293 	return EOPNOTSUPP;
294 }
295 
296 static int
297 link_listen(struct socket *so, struct lwp *l)
298 {
299 	KASSERT(solocked(so));
300 
301 	return EOPNOTSUPP;
302 }
303 
304 static int
305 link_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
306 {
307  	KASSERT(solocked(so));
308 
309 	return EOPNOTSUPP;
310 }
311 
312 static int
313 link_connect2(struct socket *so, struct socket *so2)
314 {
315  	KASSERT(solocked(so));
316 
317 	return EOPNOTSUPP;
318 }
319 
320 static int
321 link_disconnect(struct socket *so)
322 {
323 	KASSERT(solocked(so));
324 
325 	return EOPNOTSUPP;
326 }
327 
328 static int
329 link_shutdown(struct socket *so)
330 {
331 	KASSERT(solocked(so));
332 
333 	return EOPNOTSUPP;
334 }
335 
336 static int
337 link_abort(struct socket *so)
338 {
339 	KASSERT(solocked(so));
340 
341 	return EOPNOTSUPP;
342 }
343 
344 static int
345 link_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
346 {
347 	return link_control(so, cmd, nam, ifp);
348 }
349 
350 static int
351 link_stat(struct socket *so, struct stat *ub)
352 {
353 	KASSERT(solocked(so));
354 
355 	return 0;
356 }
357 
358 static int
359 link_peeraddr(struct socket *so, struct sockaddr *nam)
360 {
361 	KASSERT(solocked(so));
362 
363 	return EOPNOTSUPP;
364 }
365 
366 static int
367 link_sockaddr(struct socket *so, struct sockaddr *nam)
368 {
369  	KASSERT(solocked(so));
370 
371 	return EOPNOTSUPP;
372 }
373 
374 static int
375 link_rcvd(struct socket *so, int flags, struct lwp *l)
376 {
377 	KASSERT(solocked(so));
378 
379 	return EOPNOTSUPP;
380 }
381 
382 static int
383 link_recvoob(struct socket *so, struct mbuf *m, int flags)
384 {
385 	KASSERT(solocked(so));
386 
387 	return EOPNOTSUPP;
388 }
389 
390 static int
391 link_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
392     struct mbuf *control, struct lwp *l)
393 {
394 	KASSERT(solocked(so));
395 
396 	return EOPNOTSUPP;
397 }
398 
399 static int
400 link_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
401 {
402 	KASSERT(solocked(so));
403 
404 	return EOPNOTSUPP;
405 }
406 
407 static int
408 link_purgeif(struct socket *so, struct ifnet *ifp)
409 {
410 
411 	return EOPNOTSUPP;
412 }
413 
414 /* Compare the field at byte offsets [fieldstart, fieldend) in
415  * two memory regions, [l, l + llen) and [r, r + llen).
416  */
417 static inline int
418 submemcmp(const void *l, const void *r,
419     const uint_fast8_t llen, const uint_fast8_t rlen,
420     const uint_fast8_t fieldstart, const uint_fast8_t fieldend)
421 {
422 	uint_fast8_t cmpend, minlen;
423 	const uint8_t *lb = l, *rb = r;
424 	int rc;
425 
426 	minlen = MIN(llen, rlen);
427 
428 	/* The field is missing from one region.  The shorter region is the
429 	 * lesser region.
430 	 */
431 	if (fieldstart >= minlen)
432 		return llen - rlen;
433 
434 	/* Two empty, present fields are always equal. */
435 	if (fieldstart > fieldend)
436 		return 0;
437 
438 	cmpend = MIN(fieldend, minlen);
439 
440 	rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart);
441 
442 	if (rc != 0)
443 		return rc;
444 	/* If one or both fields are truncated, then the shorter is the lesser
445 	 * field.
446 	 */
447 	if (minlen < fieldend)
448 		return llen - rlen;
449 	/* Fields are full-length and equal.  The fields are equal. */
450 	return 0;
451 }
452 
453 uint8_t
454 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen)
455 {
456 	return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]);
457 }
458 
459 struct sockaddr *
460 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type,
461     const void *name, uint8_t namelen, const void *addr, uint8_t addrlen,
462     int flags)
463 {
464 	struct sockaddr *sa;
465 	socklen_t len;
466 
467 	len = sockaddr_dl_measure(namelen, addrlen);
468 	sa = sockaddr_alloc(AF_LINK, len, flags);
469 
470 	if (sa == NULL)
471 		return NULL;
472 
473 	if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen,
474 	    addr, addrlen) == NULL) {
475 		sockaddr_free(sa);
476 		return NULL;
477 	}
478 
479 	return sa;
480 }
481 
482 struct sockaddr_dl *
483 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex,
484     uint8_t type, const void *name, uint8_t namelen, const void *addr,
485     uint8_t addrlen)
486 {
487 	socklen_t len;
488 
489 	sdl->sdl_family = AF_LINK;
490 	sdl->sdl_slen = 0;
491 	len = sockaddr_dl_measure(namelen, addrlen);
492 	if (len > socklen) {
493 		sdl->sdl_len = socklen;
494 #ifdef DIAGNOSTIC
495 		printf("%s: too long: %u > %u\n", __func__, (u_int)len,
496 		    (u_int)socklen);
497 #endif
498 		return NULL;
499 	}
500 	sdl->sdl_len = len;
501 	sdl->sdl_index = ifindex;
502 	sdl->sdl_type = type;
503 	memset(&sdl->sdl_data[0], 0, namelen + addrlen);
504 	if (name != NULL) {
505 		memcpy(&sdl->sdl_data[0], name, namelen);
506 		sdl->sdl_nlen = namelen;
507 	} else
508 		sdl->sdl_nlen = 0;
509 	if (addr != NULL) {
510 		memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
511 		sdl->sdl_alen = addrlen;
512 	} else
513 		sdl->sdl_alen = 0;
514 	return sdl;
515 }
516 
517 static int
518 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
519 {
520 	int rc;
521 	const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index);
522 	const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen);
523 	uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]);
524 	const struct sockaddr_dl *sdl1, *sdl2;
525 
526 	sdl1 = satocsdl(sa1);
527 	sdl2 = satocsdl(sa2);
528 
529 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
530 	    indexofs, nlenofs);
531 
532 	if (rc != 0)
533 		return rc;
534 
535 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
536 	    dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen));
537 
538 	if (rc != 0)
539 		return rc;
540 
541 	if (sdl1->sdl_nlen != sdl2->sdl_nlen)
542 		return sdl1->sdl_nlen - sdl2->sdl_nlen;
543 
544 	dataofs += sdl1->sdl_nlen;
545 
546 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
547 	    dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen));
548 
549 	if (rc != 0)
550 		return rc;
551 
552 	if (sdl1->sdl_alen != sdl2->sdl_alen)
553 		return sdl1->sdl_alen - sdl2->sdl_alen;
554 
555 	dataofs += sdl1->sdl_alen;
556 
557 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
558 	    dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen));
559 
560 	if (sdl1->sdl_slen != sdl2->sdl_slen)
561 		return sdl1->sdl_slen - sdl2->sdl_slen;
562 
563 	return sdl1->sdl_len - sdl2->sdl_len;
564 }
565 
566 struct sockaddr_dl *
567 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen,
568     const void *addr, uint8_t addrlen)
569 {
570 	socklen_t len;
571 
572 	len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen);
573 	if (len > socklen) {
574 #ifdef DIAGNOSTIC
575 		printf("%s: too long: %u > %u\n", __func__, (u_int)len,
576 		    (u_int)socklen);
577 #endif
578 		return NULL;
579 	}
580 	memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
581 	sdl->sdl_alen = addrlen;
582 	sdl->sdl_len = len;
583 	return sdl;
584 }
585