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link_proto.c revision 1.7 
      1 /*	$NetBSD: link_proto.c,v 1.7 2011/10/07 16:34:31 dyoung 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 1.7 2011/10/07 16:34:31 dyoung 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_usrreq(struct socket *, int, struct mbuf *, struct mbuf *,
     52     struct mbuf *, struct lwp *);
     53 static void link_init(void);
     54 
     55 /*
     56  * Definitions of protocols supported in the link-layer domain.
     57  */
     58 
     59 DOMAIN_DEFINE(linkdomain);	/* forward define and add to link set */
     60 
     61 const struct protosw linksw[] = {
     62 	{	.pr_type = SOCK_DGRAM,
     63 		.pr_domain = &linkdomain,
     64 		.pr_protocol = 0,	/* XXX */
     65 		.pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
     66 		.pr_input = NULL,
     67 		.pr_ctlinput = NULL,
     68 		.pr_ctloutput = NULL,
     69 		.pr_usrreq = link_usrreq,
     70 		.pr_init = link_init,
     71 	},
     72 };
     73 
     74 struct domain linkdomain = {
     75 	.dom_family = AF_LINK,
     76 	.dom_name = "link",
     77 	.dom_externalize = NULL,
     78 	.dom_dispose = NULL,
     79 	.dom_protosw = linksw,
     80 	.dom_protoswNPROTOSW = &linksw[__arraycount(linksw)],
     81 	.dom_sockaddr_cmp = sockaddr_dl_cmp
     82 };
     83 
     84 static void
     85 link_init(void)
     86 {
     87 	return;
     88 }
     89 
     90 static int
     91 link_control(struct socket *so, unsigned long cmd, void *data,
     92     struct ifnet *ifp, struct lwp *l)
     93 {
     94 	int error, s;
     95 	bool isactive, mkactive;
     96 	struct if_laddrreq *iflr;
     97 	union {
     98 		struct sockaddr sa;
     99 		struct sockaddr_dl sdl;
    100 		struct sockaddr_storage ss;
    101 	} u;
    102 	struct ifaddr *ifa;
    103 	const struct sockaddr_dl *asdl, *nsdl;
    104 
    105 	switch (cmd) {
    106 	case SIOCALIFADDR:
    107 	case SIOCDLIFADDR:
    108 	case SIOCGLIFADDR:
    109 		iflr = data;
    110 
    111 		if (iflr->addr.ss_family != AF_LINK)
    112 			return EINVAL;
    113 
    114 		asdl = satocsdl(sstocsa(&iflr->addr));
    115 
    116 		if (asdl->sdl_alen != ifp->if_addrlen)
    117 			return EINVAL;
    118 
    119 		if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), ifp->if_index,
    120 		    ifp->if_type, ifp->if_xname, strlen(ifp->if_xname),
    121 		    CLLADDR(asdl), asdl->sdl_alen) == NULL)
    122 			return EINVAL;
    123 
    124 		if ((iflr->flags & IFLR_PREFIX) == 0)
    125 			;
    126 		else if (iflr->prefixlen != NBBY * ifp->if_addrlen)
    127 			return EINVAL;	/* XXX match with prefix */
    128 
    129 		error = 0;
    130 
    131 		s = splnet();
    132 
    133 		IFADDR_FOREACH(ifa, ifp) {
    134 			if (sockaddr_cmp(&u.sa, ifa->ifa_addr) == 0)
    135 				break;
    136 		}
    137 
    138 		switch (cmd) {
    139 		case SIOCGLIFADDR:
    140 			if ((iflr->flags & IFLR_PREFIX) == 0) {
    141 				IFADDR_FOREACH(ifa, ifp) {
    142 					if (ifa->ifa_addr->sa_family == AF_LINK)
    143 						break;
    144 				}
    145 			}
    146 			if (ifa == NULL) {
    147 				error = EADDRNOTAVAIL;
    148 				break;
    149 			}
    150 
    151 			if (ifa == ifp->if_dl)
    152 				iflr->flags = IFLR_ACTIVE;
    153 			else
    154 				iflr->flags = 0;
    155 
    156 			if (ifa == ifp->if_hwdl)
    157 				iflr->flags |= IFLR_FACTORY;
    158 
    159 			sockaddr_copy(sstosa(&iflr->addr), sizeof(iflr->addr),
    160 			    ifa->ifa_addr);
    161 
    162 			break;
    163 		case SIOCDLIFADDR:
    164 			if (ifa == NULL)
    165 				error = EADDRNOTAVAIL;
    166 			else if (ifa == ifp->if_dl || ifa == ifp->if_hwdl)
    167 				error = EBUSY;
    168 			else {
    169 				/* TBD routing socket */
    170 				rt_newaddrmsg(RTM_DELETE, ifa, 0, NULL);
    171 				ifa_remove(ifp, ifa);
    172 			}
    173 			break;
    174 		case SIOCALIFADDR:
    175 			if (ifa != NULL)
    176 				;
    177 			else if ((ifa = if_dl_create(ifp, &nsdl)) == NULL) {
    178 				error = ENOMEM;
    179 				break;
    180 			} else {
    181 				sockaddr_copy(ifa->ifa_addr,
    182 				    ifa->ifa_addr->sa_len, &u.sa);
    183 				ifa_insert(ifp, ifa);
    184 				rt_newaddrmsg(RTM_ADD, ifa, 0, NULL);
    185 			}
    186 
    187 			mkactive = (iflr->flags & IFLR_ACTIVE) != 0;
    188 			isactive = (ifa == ifp->if_dl);
    189 
    190 			if (!isactive && mkactive) {
    191 				if_activate_sadl(ifp, ifa, nsdl);
    192 				rt_newaddrmsg(RTM_CHANGE, ifa, 0, NULL);
    193 				error = ENETRESET;
    194 			}
    195 			break;
    196 		}
    197 		splx(s);
    198 		if (error != ENETRESET)
    199 			return error;
    200 		else if ((ifp->if_flags & IFF_RUNNING) != 0)
    201 			return (*ifp->if_init)(ifp);
    202 		else
    203 			return 0;
    204 	default:
    205 		return ENOTTY;
    206 	}
    207 }
    208 
    209 static int
    210 link_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
    211 	struct mbuf *control, struct lwp *l)
    212 {
    213 	switch (req) {
    214 	case PRU_ATTACH:
    215 		sosetlock(so);
    216 		return 0;
    217 	case PRU_DETACH:
    218 		sofree(so);
    219 		return 0;
    220 	case PRU_CONTROL:
    221 		return link_control(so, (unsigned long)m, nam,
    222 		    (struct ifnet *)control, l);
    223 	default:
    224 		return EOPNOTSUPP;
    225 	}
    226 }
    227 
    228 /* Compare the field at byte offsets [fieldstart, fieldend) in
    229  * two memory regions, [l, l + llen) and [r, r + llen).
    230  */
    231 static inline int
    232 submemcmp(const void *l, const void *r,
    233     const uint_fast8_t llen, const uint_fast8_t rlen,
    234     const uint_fast8_t fieldstart, const uint_fast8_t fieldend)
    235 {
    236 	uint_fast8_t cmpend, minlen;
    237 	const uint8_t *lb = l, *rb = r;
    238 	int rc;
    239 
    240 	minlen = MIN(llen, rlen);
    241 
    242 	/* The field is missing from one region.  The shorter region is the
    243 	 * lesser region.
    244 	 */
    245 	if (fieldstart >= minlen)
    246 		return llen - rlen;
    247 
    248 	/* Two empty, present fields are always equal. */
    249 	if (fieldstart > fieldend)
    250 		return 0;
    251 
    252 	cmpend = MIN(fieldend, minlen);
    253 
    254 	rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart);
    255 
    256 	if (rc != 0)
    257 		return rc;
    258 	/* If one or both fields are truncated, then the shorter is the lesser
    259 	 * field.
    260 	 */
    261 	if (minlen < fieldend)
    262 		return llen - rlen;
    263 	/* Fields are full-length and equal.  The fields are equal. */
    264 	return 0;
    265 }
    266 
    267 uint8_t
    268 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen)
    269 {
    270 	return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]);
    271 }
    272 
    273 struct sockaddr *
    274 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type,
    275     const void *name, uint8_t namelen, const void *addr, uint8_t addrlen,
    276     int flags)
    277 {
    278 	struct sockaddr *sa;
    279 	socklen_t len;
    280 
    281 	len = sockaddr_dl_measure(namelen, addrlen);
    282 	sa = sockaddr_alloc(AF_LINK, len, flags);
    283 
    284 	if (sa == NULL)
    285 		return NULL;
    286 
    287 	if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen,
    288 	    addr, addrlen) == NULL) {
    289 		sockaddr_free(sa);
    290 		return NULL;
    291 	}
    292 
    293 	return sa;
    294 }
    295 
    296 struct sockaddr_dl *
    297 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex,
    298     uint8_t type, const void *name, uint8_t namelen, const void *addr,
    299     uint8_t addrlen)
    300 {
    301 	socklen_t len;
    302 
    303 	sdl->sdl_family = AF_LINK;
    304 	sdl->sdl_slen = 0;
    305 	len = sockaddr_dl_measure(namelen, addrlen);
    306 	if (len > socklen) {
    307 		sdl->sdl_len = socklen;
    308 #ifdef DIAGNOSTIC
    309 		printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
    310 		    socklen);
    311 #endif
    312 		return NULL;
    313 	}
    314 	sdl->sdl_len = len;
    315 	sdl->sdl_index = ifindex;
    316 	sdl->sdl_type = type;
    317 	memset(&sdl->sdl_data[0], 0, namelen + addrlen);
    318 	if (name != NULL) {
    319 		memcpy(&sdl->sdl_data[0], name, namelen);
    320 		sdl->sdl_nlen = namelen;
    321 	} else
    322 		sdl->sdl_nlen = 0;
    323 	if (addr != NULL) {
    324 		memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
    325 		sdl->sdl_alen = addrlen;
    326 	} else
    327 		sdl->sdl_alen = 0;
    328 	return sdl;
    329 }
    330 
    331 static int
    332 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
    333 {
    334 	int rc;
    335 	const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index);
    336 	const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen);
    337 	uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]);
    338 	const struct sockaddr_dl *sdl1, *sdl2;
    339 
    340 	sdl1 = satocsdl(sa1);
    341 	sdl2 = satocsdl(sa2);
    342 
    343 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    344 	    indexofs, nlenofs);
    345 
    346 	if (rc != 0)
    347 		return rc;
    348 
    349 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    350 	    dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen));
    351 
    352 	if (rc != 0)
    353 		return rc;
    354 
    355 	if (sdl1->sdl_nlen != sdl2->sdl_nlen)
    356 		return sdl1->sdl_nlen - sdl2->sdl_nlen;
    357 
    358 	dataofs += sdl1->sdl_nlen;
    359 
    360 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    361 	    dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen));
    362 
    363 	if (rc != 0)
    364 		return rc;
    365 
    366 	if (sdl1->sdl_alen != sdl2->sdl_alen)
    367 		return sdl1->sdl_alen - sdl2->sdl_alen;
    368 
    369 	dataofs += sdl1->sdl_alen;
    370 
    371 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    372 	    dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen));
    373 
    374 	if (sdl1->sdl_slen != sdl2->sdl_slen)
    375 		return sdl1->sdl_slen - sdl2->sdl_slen;
    376 
    377 	return sdl1->sdl_len - sdl2->sdl_len;
    378 }
    379 
    380 struct sockaddr_dl *
    381 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen,
    382     const void *addr, uint8_t addrlen)
    383 {
    384 	socklen_t len;
    385 
    386 	len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen);
    387 	if (len > socklen) {
    388 #ifdef DIAGNOSTIC
    389 		printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
    390 		    socklen);
    391 #endif
    392 		return NULL;
    393 	}
    394 	memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
    395 	sdl->sdl_alen = addrlen;
    396 	sdl->sdl_len = len;
    397 	return sdl;
    398 }
    399