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link_proto.c revision 1.5 
      1 /*	$NetBSD: link_proto.c,v 1.5 2008/11/07 00:20:13 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 1.5 2008/11/07 00:20:13 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 				error = ENETRESET;
    193 			}
    194 			break;
    195 		}
    196 		splx(s);
    197 		if (error != ENETRESET)
    198 			return error;
    199 		else if ((ifp->if_flags & IFF_RUNNING) != 0)
    200 			return (*ifp->if_init)(ifp);
    201 		else
    202 			return 0;
    203 	default:
    204 		return ENOTTY;
    205 	}
    206 }
    207 
    208 static int
    209 link_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
    210 	struct mbuf *control, struct lwp *l)
    211 {
    212 	switch (req) {
    213 	case PRU_ATTACH:
    214 		sosetlock(so);
    215 		return 0;
    216 	case PRU_DETACH:
    217 		sofree(so);
    218 		return 0;
    219 	case PRU_CONTROL:
    220 		return link_control(so, (unsigned long)m, nam,
    221 		    (struct ifnet *)control, l);
    222 	default:
    223 		return EOPNOTSUPP;
    224 	}
    225 }
    226 
    227 /* Compare the field at byte offsets [fieldstart, fieldend) in
    228  * two memory regions, [l, l + llen) and [r, r + llen).
    229  */
    230 static inline int
    231 submemcmp(const void *l, const void *r,
    232     const uint_fast8_t llen, const uint_fast8_t rlen,
    233     const uint_fast8_t fieldstart, const uint_fast8_t fieldend)
    234 {
    235 	uint_fast8_t cmpend, minlen;
    236 	const uint8_t *lb = l, *rb = r;
    237 	int rc;
    238 
    239 	minlen = MIN(llen, rlen);
    240 
    241 	/* The field is missing from one region.  The shorter region is the
    242 	 * lesser region.
    243 	 */
    244 	if (fieldstart >= minlen)
    245 		return llen - rlen;
    246 
    247 	/* Two empty, present fields are always equal. */
    248 	if (fieldstart > fieldend)
    249 		return 0;
    250 
    251 	cmpend = MIN(fieldend, minlen);
    252 
    253 	rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart);
    254 
    255 	if (rc != 0)
    256 		return rc;
    257 	/* If one or both fields are truncated, then the shorter is the lesser
    258 	 * field.
    259 	 */
    260 	if (minlen < fieldend)
    261 		return llen - rlen;
    262 	/* Fields are full-length and equal.  The fields are equal. */
    263 	return 0;
    264 }
    265 
    266 uint8_t
    267 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen)
    268 {
    269 	return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]);
    270 }
    271 
    272 struct sockaddr *
    273 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type,
    274     const void *name, uint8_t namelen, const void *addr, uint8_t addrlen,
    275     int flags)
    276 {
    277 	struct sockaddr *sa;
    278 	socklen_t len;
    279 
    280 	len = sockaddr_dl_measure(namelen, addrlen);
    281 	sa = sockaddr_alloc(AF_LINK, len, flags);
    282 
    283 	if (sa == NULL)
    284 		return NULL;
    285 
    286 	if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen,
    287 	    addr, addrlen) == NULL) {
    288 		sockaddr_free(sa);
    289 		return NULL;
    290 	}
    291 
    292 	return sa;
    293 }
    294 
    295 struct sockaddr_dl *
    296 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex,
    297     uint8_t type, const void *name, uint8_t namelen, const void *addr,
    298     uint8_t addrlen)
    299 {
    300 	socklen_t len;
    301 
    302 	sdl->sdl_family = AF_LINK;
    303 	sdl->sdl_slen = 0;
    304 	len = sockaddr_dl_measure(namelen, addrlen);
    305 	if (len > socklen) {
    306 		sdl->sdl_len = socklen;
    307 #ifdef DIAGNOSTIC
    308 		printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
    309 		    socklen);
    310 #endif
    311 		return NULL;
    312 	}
    313 	sdl->sdl_len = len;
    314 	sdl->sdl_index = ifindex;
    315 	sdl->sdl_type = type;
    316 	memset(&sdl->sdl_data[0], 0, namelen + addrlen);
    317 	if (name != NULL) {
    318 		memcpy(&sdl->sdl_data[0], name, namelen);
    319 		sdl->sdl_nlen = namelen;
    320 	} else
    321 		sdl->sdl_nlen = 0;
    322 	if (addr != NULL) {
    323 		memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
    324 		sdl->sdl_alen = addrlen;
    325 	} else
    326 		sdl->sdl_alen = 0;
    327 	return sdl;
    328 }
    329 
    330 static int
    331 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
    332 {
    333 	int rc;
    334 	const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index);
    335 	const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen);
    336 	uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]);
    337 	const struct sockaddr_dl *sdl1, *sdl2;
    338 
    339 	sdl1 = satocsdl(sa1);
    340 	sdl2 = satocsdl(sa2);
    341 
    342 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    343 	    indexofs, nlenofs);
    344 
    345 	if (rc != 0)
    346 		return rc;
    347 
    348 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    349 	    dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen));
    350 
    351 	if (rc != 0)
    352 		return rc;
    353 
    354 	if (sdl1->sdl_nlen != sdl2->sdl_nlen)
    355 		return sdl1->sdl_nlen - sdl2->sdl_nlen;
    356 
    357 	dataofs += sdl1->sdl_nlen;
    358 
    359 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    360 	    dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen));
    361 
    362 	if (rc != 0)
    363 		return rc;
    364 
    365 	if (sdl1->sdl_alen != sdl2->sdl_alen)
    366 		return sdl1->sdl_alen - sdl2->sdl_alen;
    367 
    368 	dataofs += sdl1->sdl_alen;
    369 
    370 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    371 	    dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen));
    372 
    373 	if (sdl1->sdl_slen != sdl2->sdl_slen)
    374 		return sdl1->sdl_slen - sdl2->sdl_slen;
    375 
    376 	return sdl1->sdl_len - sdl2->sdl_len;
    377 }
    378 
    379 struct sockaddr_dl *
    380 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen,
    381     const void *addr, uint8_t addrlen)
    382 {
    383 	socklen_t len;
    384 
    385 	len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen);
    386 	if (len > socklen) {
    387 #ifdef DIAGNOSTIC
    388 		printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
    389 		    socklen);
    390 #endif
    391 		return NULL;
    392 	}
    393 	memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
    394 	sdl->sdl_alen = addrlen;
    395 	sdl->sdl_len = len;
    396 	return sdl;
    397 }
    398