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link_proto.c revision 1.23
      1 /*	$NetBSD: link_proto.c,v 1.23 2014/08/08 03:05:45 rtr 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 1.23 2014/08/08 03:05:45 rtr 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 mbuf *);
     54 static int link_bind(struct socket *, struct mbuf *, struct lwp *);
     55 static int link_listen(struct socket *, struct lwp *);
     56 static int link_connect(struct socket *, struct mbuf *, struct lwp *);
     57 static int link_disconnect(struct socket *);
     58 static int link_shutdown(struct socket *);
     59 static int link_abort(struct socket *);
     60 static int link_ioctl(struct socket *, u_long, void *, struct ifnet *);
     61 static int link_stat(struct socket *, struct stat *);
     62 static int link_peeraddr(struct socket *, struct mbuf *);
     63 static int link_sockaddr(struct socket *, struct mbuf *);
     64 static int link_rcvd(struct socket *, int, struct lwp *);
     65 static int link_recvoob(struct socket *, struct mbuf *, int);
     66 static int link_send(struct socket *, struct mbuf *, struct mbuf *,
     67     struct mbuf *, struct lwp *);
     68 static int link_sendoob(struct socket *, struct mbuf *, struct mbuf *);
     69 static int link_usrreq(struct socket *, int, struct mbuf *, struct mbuf *,
     70     struct mbuf *, struct lwp *);
     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_disconnect	= link_disconnect,
     87 	.pr_shutdown	= link_shutdown,
     88 	.pr_abort	= link_abort,
     89 	.pr_ioctl	= link_ioctl,
     90 	.pr_stat	= link_stat,
     91 	.pr_peeraddr	= link_peeraddr,
     92 	.pr_sockaddr	= link_sockaddr,
     93 	.pr_rcvd	= link_rcvd,
     94 	.pr_recvoob	= link_recvoob,
     95 	.pr_send	= link_send,
     96 	.pr_sendoob	= link_sendoob,
     97 	.pr_generic	= link_usrreq,
     98 };
     99 
    100 const struct protosw linksw[] = {
    101 	{	.pr_type = SOCK_DGRAM,
    102 		.pr_domain = &linkdomain,
    103 		.pr_protocol = 0,	/* XXX */
    104 		.pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
    105 		.pr_input = NULL,
    106 		.pr_ctlinput = NULL,
    107 		.pr_ctloutput = NULL,
    108 		.pr_usrreqs = &link_usrreqs,
    109 		.pr_init = link_init,
    110 	},
    111 };
    112 
    113 struct domain linkdomain = {
    114 	.dom_family = AF_LINK,
    115 	.dom_name = "link",
    116 	.dom_externalize = NULL,
    117 	.dom_dispose = NULL,
    118 	.dom_protosw = linksw,
    119 	.dom_protoswNPROTOSW = &linksw[__arraycount(linksw)],
    120 	.dom_sockaddr_cmp = sockaddr_dl_cmp
    121 };
    122 
    123 static void
    124 link_init(void)
    125 {
    126 	return;
    127 }
    128 
    129 static int
    130 link_control(struct socket *so, unsigned long cmd, void *data,
    131     struct ifnet *ifp)
    132 {
    133 	int error, s;
    134 	bool isactive, mkactive;
    135 	struct if_laddrreq *iflr;
    136 	union {
    137 		struct sockaddr sa;
    138 		struct sockaddr_dl sdl;
    139 		struct sockaddr_storage ss;
    140 	} u;
    141 	struct ifaddr *ifa;
    142 	const struct sockaddr_dl *asdl, *nsdl;
    143 
    144 	switch (cmd) {
    145 	case SIOCALIFADDR:
    146 	case SIOCDLIFADDR:
    147 	case SIOCGLIFADDR:
    148 		iflr = data;
    149 
    150 		if (iflr->addr.ss_family != AF_LINK)
    151 			return EINVAL;
    152 
    153 		asdl = satocsdl(sstocsa(&iflr->addr));
    154 
    155 		if (asdl->sdl_alen != ifp->if_addrlen)
    156 			return EINVAL;
    157 
    158 		if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), ifp->if_index,
    159 		    ifp->if_type, ifp->if_xname, strlen(ifp->if_xname),
    160 		    CLLADDR(asdl), asdl->sdl_alen) == NULL)
    161 			return EINVAL;
    162 
    163 		if ((iflr->flags & IFLR_PREFIX) == 0)
    164 			;
    165 		else if (iflr->prefixlen != NBBY * ifp->if_addrlen)
    166 			return EINVAL;	/* XXX match with prefix */
    167 
    168 		error = 0;
    169 
    170 		s = splnet();
    171 
    172 		IFADDR_FOREACH(ifa, ifp) {
    173 			if (sockaddr_cmp(&u.sa, ifa->ifa_addr) == 0)
    174 				break;
    175 		}
    176 
    177 		switch (cmd) {
    178 		case SIOCGLIFADDR:
    179 			if ((iflr->flags & IFLR_PREFIX) == 0) {
    180 				IFADDR_FOREACH(ifa, ifp) {
    181 					if (ifa->ifa_addr->sa_family == AF_LINK)
    182 						break;
    183 				}
    184 			}
    185 			if (ifa == NULL) {
    186 				error = EADDRNOTAVAIL;
    187 				break;
    188 			}
    189 
    190 			if (ifa == ifp->if_dl)
    191 				iflr->flags = IFLR_ACTIVE;
    192 			else
    193 				iflr->flags = 0;
    194 
    195 			if (ifa == ifp->if_hwdl)
    196 				iflr->flags |= IFLR_FACTORY;
    197 
    198 			sockaddr_copy(sstosa(&iflr->addr), sizeof(iflr->addr),
    199 			    ifa->ifa_addr);
    200 
    201 			break;
    202 		case SIOCDLIFADDR:
    203 			if (ifa == NULL)
    204 				error = EADDRNOTAVAIL;
    205 			else if (ifa == ifp->if_dl || ifa == ifp->if_hwdl)
    206 				error = EBUSY;
    207 			else {
    208 				/* TBD routing socket */
    209 				rt_newaddrmsg(RTM_DELETE, ifa, 0, NULL);
    210 				ifa_remove(ifp, ifa);
    211 			}
    212 			break;
    213 		case SIOCALIFADDR:
    214 			if (ifa != NULL)
    215 				;
    216 			else if ((ifa = if_dl_create(ifp, &nsdl)) == NULL) {
    217 				error = ENOMEM;
    218 				break;
    219 			} else {
    220 				sockaddr_copy(ifa->ifa_addr,
    221 				    ifa->ifa_addr->sa_len, &u.sa);
    222 				ifa_insert(ifp, ifa);
    223 				rt_newaddrmsg(RTM_ADD, ifa, 0, NULL);
    224 			}
    225 
    226 			mkactive = (iflr->flags & IFLR_ACTIVE) != 0;
    227 			isactive = (ifa == ifp->if_dl);
    228 
    229 			if (!isactive && mkactive) {
    230 				if_activate_sadl(ifp, ifa, nsdl);
    231 				rt_newaddrmsg(RTM_CHANGE, ifa, 0, NULL);
    232 				error = ENETRESET;
    233 			}
    234 			break;
    235 		}
    236 		splx(s);
    237 		if (error != ENETRESET)
    238 			return error;
    239 		else if ((ifp->if_flags & IFF_RUNNING) != 0 &&
    240 		         ifp->if_init != NULL)
    241 			return (*ifp->if_init)(ifp);
    242 		else
    243 			return 0;
    244 	default:
    245 		return ENOTTY;
    246 	}
    247 }
    248 
    249 static int
    250 link_attach(struct socket *so, int proto)
    251 {
    252 	sosetlock(so);
    253 	KASSERT(solocked(so));
    254 	return 0;
    255 }
    256 
    257 static void
    258 link_detach(struct socket *so)
    259 {
    260 	KASSERT(solocked(so));
    261 	sofree(so);
    262 }
    263 
    264 static int
    265 link_accept(struct socket *so, struct mbuf *nam)
    266 {
    267 	KASSERT(solocked(so));
    268 
    269 	return EOPNOTSUPP;
    270 }
    271 
    272 static int
    273 link_bind(struct socket *so, struct mbuf *nam, struct lwp *l)
    274 {
    275 	KASSERT(solocked(so));
    276 
    277 	return EOPNOTSUPP;
    278 }
    279 
    280 static int
    281 link_listen(struct socket *so, struct lwp *l)
    282 {
    283 	KASSERT(solocked(so));
    284 
    285 	return EOPNOTSUPP;
    286 }
    287 
    288 static int
    289 link_connect(struct socket *so, struct mbuf *nam, struct lwp *l)
    290 {
    291  	KASSERT(solocked(so));
    292 
    293 	return EOPNOTSUPP;
    294 }
    295 
    296 static int
    297 link_disconnect(struct socket *so)
    298 {
    299 	KASSERT(solocked(so));
    300 
    301 	return EOPNOTSUPP;
    302 }
    303 
    304 static int
    305 link_shutdown(struct socket *so)
    306 {
    307 	KASSERT(solocked(so));
    308 
    309 	return EOPNOTSUPP;
    310 }
    311 
    312 static int
    313 link_abort(struct socket *so)
    314 {
    315 	KASSERT(solocked(so));
    316 
    317 	return EOPNOTSUPP;
    318 }
    319 
    320 static int
    321 link_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
    322 {
    323 	return link_control(so, cmd, nam, ifp);
    324 }
    325 
    326 static int
    327 link_stat(struct socket *so, struct stat *ub)
    328 {
    329 	KASSERT(solocked(so));
    330 
    331 	return EOPNOTSUPP;
    332 }
    333 
    334 static int
    335 link_peeraddr(struct socket *so, struct mbuf *nam)
    336 {
    337 	KASSERT(solocked(so));
    338 
    339 	return EOPNOTSUPP;
    340 }
    341 
    342 static int
    343 link_sockaddr(struct socket *so, struct mbuf *nam)
    344 {
    345  	KASSERT(solocked(so));
    346 
    347 	return EOPNOTSUPP;
    348 }
    349 
    350 static int
    351 link_rcvd(struct socket *so, int flags, struct lwp *l)
    352 {
    353 	KASSERT(solocked(so));
    354 
    355 	return EOPNOTSUPP;
    356 }
    357 
    358 static int
    359 link_recvoob(struct socket *so, struct mbuf *m, int flags)
    360 {
    361 	KASSERT(solocked(so));
    362 
    363 	return EOPNOTSUPP;
    364 }
    365 
    366 static int
    367 link_send(struct socket *so, struct mbuf *m, struct mbuf *nam,
    368     struct mbuf *control, struct lwp *l)
    369 {
    370 	KASSERT(solocked(so));
    371 
    372 	return EOPNOTSUPP;
    373 }
    374 
    375 static int
    376 link_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
    377 {
    378 	KASSERT(solocked(so));
    379 
    380 	return EOPNOTSUPP;
    381 }
    382 
    383 static int
    384 link_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
    385 	struct mbuf *control, struct lwp *l)
    386 {
    387 	KASSERT(req != PRU_ATTACH);
    388 	KASSERT(req != PRU_DETACH);
    389 	KASSERT(req != PRU_ACCEPT);
    390 	KASSERT(req != PRU_BIND);
    391 	KASSERT(req != PRU_LISTEN);
    392 	KASSERT(req != PRU_CONNECT);
    393 	KASSERT(req != PRU_DISCONNECT);
    394 	KASSERT(req != PRU_SHUTDOWN);
    395 	KASSERT(req != PRU_ABORT);
    396 	KASSERT(req != PRU_CONTROL);
    397 	KASSERT(req != PRU_SENSE);
    398 	KASSERT(req != PRU_PEERADDR);
    399 	KASSERT(req != PRU_SOCKADDR);
    400 	KASSERT(req != PRU_RCVD);
    401 	KASSERT(req != PRU_RCVOOB);
    402 	KASSERT(req != PRU_SEND);
    403 	KASSERT(req != PRU_SENDOOB);
    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