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link_proto.c revision 1.8 
      1 /*	$NetBSD: link_proto.c,v 1.8 2014/05/18 14:46:16 rmind 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 1.8 2014/05/18 14:46:16 rmind 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 static const struct pr_usrreqs link_usrreqs = {
     62 	.pr_generic	= link_usrreq,
     63 };
     64 
     65 const struct protosw linksw[] = {
     66 	{	.pr_type = SOCK_DGRAM,
     67 		.pr_domain = &linkdomain,
     68 		.pr_protocol = 0,	/* XXX */
     69 		.pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
     70 		.pr_input = NULL,
     71 		.pr_ctlinput = NULL,
     72 		.pr_ctloutput = NULL,
     73 		.pr_usrreqs = &link_usrreqs,
     74 		.pr_init = link_init,
     75 	},
     76 };
     77 
     78 struct domain linkdomain = {
     79 	.dom_family = AF_LINK,
     80 	.dom_name = "link",
     81 	.dom_externalize = NULL,
     82 	.dom_dispose = NULL,
     83 	.dom_protosw = linksw,
     84 	.dom_protoswNPROTOSW = &linksw[__arraycount(linksw)],
     85 	.dom_sockaddr_cmp = sockaddr_dl_cmp
     86 };
     87 
     88 static void
     89 link_init(void)
     90 {
     91 	return;
     92 }
     93 
     94 static int
     95 link_control(struct socket *so, unsigned long cmd, void *data,
     96     struct ifnet *ifp, struct lwp *l)
     97 {
     98 	int error, s;
     99 	bool isactive, mkactive;
    100 	struct if_laddrreq *iflr;
    101 	union {
    102 		struct sockaddr sa;
    103 		struct sockaddr_dl sdl;
    104 		struct sockaddr_storage ss;
    105 	} u;
    106 	struct ifaddr *ifa;
    107 	const struct sockaddr_dl *asdl, *nsdl;
    108 
    109 	switch (cmd) {
    110 	case SIOCALIFADDR:
    111 	case SIOCDLIFADDR:
    112 	case SIOCGLIFADDR:
    113 		iflr = data;
    114 
    115 		if (iflr->addr.ss_family != AF_LINK)
    116 			return EINVAL;
    117 
    118 		asdl = satocsdl(sstocsa(&iflr->addr));
    119 
    120 		if (asdl->sdl_alen != ifp->if_addrlen)
    121 			return EINVAL;
    122 
    123 		if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), ifp->if_index,
    124 		    ifp->if_type, ifp->if_xname, strlen(ifp->if_xname),
    125 		    CLLADDR(asdl), asdl->sdl_alen) == NULL)
    126 			return EINVAL;
    127 
    128 		if ((iflr->flags & IFLR_PREFIX) == 0)
    129 			;
    130 		else if (iflr->prefixlen != NBBY * ifp->if_addrlen)
    131 			return EINVAL;	/* XXX match with prefix */
    132 
    133 		error = 0;
    134 
    135 		s = splnet();
    136 
    137 		IFADDR_FOREACH(ifa, ifp) {
    138 			if (sockaddr_cmp(&u.sa, ifa->ifa_addr) == 0)
    139 				break;
    140 		}
    141 
    142 		switch (cmd) {
    143 		case SIOCGLIFADDR:
    144 			if ((iflr->flags & IFLR_PREFIX) == 0) {
    145 				IFADDR_FOREACH(ifa, ifp) {
    146 					if (ifa->ifa_addr->sa_family == AF_LINK)
    147 						break;
    148 				}
    149 			}
    150 			if (ifa == NULL) {
    151 				error = EADDRNOTAVAIL;
    152 				break;
    153 			}
    154 
    155 			if (ifa == ifp->if_dl)
    156 				iflr->flags = IFLR_ACTIVE;
    157 			else
    158 				iflr->flags = 0;
    159 
    160 			if (ifa == ifp->if_hwdl)
    161 				iflr->flags |= IFLR_FACTORY;
    162 
    163 			sockaddr_copy(sstosa(&iflr->addr), sizeof(iflr->addr),
    164 			    ifa->ifa_addr);
    165 
    166 			break;
    167 		case SIOCDLIFADDR:
    168 			if (ifa == NULL)
    169 				error = EADDRNOTAVAIL;
    170 			else if (ifa == ifp->if_dl || ifa == ifp->if_hwdl)
    171 				error = EBUSY;
    172 			else {
    173 				/* TBD routing socket */
    174 				rt_newaddrmsg(RTM_DELETE, ifa, 0, NULL);
    175 				ifa_remove(ifp, ifa);
    176 			}
    177 			break;
    178 		case SIOCALIFADDR:
    179 			if (ifa != NULL)
    180 				;
    181 			else if ((ifa = if_dl_create(ifp, &nsdl)) == NULL) {
    182 				error = ENOMEM;
    183 				break;
    184 			} else {
    185 				sockaddr_copy(ifa->ifa_addr,
    186 				    ifa->ifa_addr->sa_len, &u.sa);
    187 				ifa_insert(ifp, ifa);
    188 				rt_newaddrmsg(RTM_ADD, ifa, 0, NULL);
    189 			}
    190 
    191 			mkactive = (iflr->flags & IFLR_ACTIVE) != 0;
    192 			isactive = (ifa == ifp->if_dl);
    193 
    194 			if (!isactive && mkactive) {
    195 				if_activate_sadl(ifp, ifa, nsdl);
    196 				rt_newaddrmsg(RTM_CHANGE, ifa, 0, NULL);
    197 				error = ENETRESET;
    198 			}
    199 			break;
    200 		}
    201 		splx(s);
    202 		if (error != ENETRESET)
    203 			return error;
    204 		else if ((ifp->if_flags & IFF_RUNNING) != 0)
    205 			return (*ifp->if_init)(ifp);
    206 		else
    207 			return 0;
    208 	default:
    209 		return ENOTTY;
    210 	}
    211 }
    212 
    213 static int
    214 link_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
    215 	struct mbuf *control, struct lwp *l)
    216 {
    217 	switch (req) {
    218 	case PRU_ATTACH:
    219 		sosetlock(so);
    220 		return 0;
    221 	case PRU_DETACH:
    222 		sofree(so);
    223 		return 0;
    224 	case PRU_CONTROL:
    225 		return link_control(so, (unsigned long)m, nam,
    226 		    (struct ifnet *)control, l);
    227 	default:
    228 		return EOPNOTSUPP;
    229 	}
    230 }
    231 
    232 /* Compare the field at byte offsets [fieldstart, fieldend) in
    233  * two memory regions, [l, l + llen) and [r, r + llen).
    234  */
    235 static inline int
    236 submemcmp(const void *l, const void *r,
    237     const uint_fast8_t llen, const uint_fast8_t rlen,
    238     const uint_fast8_t fieldstart, const uint_fast8_t fieldend)
    239 {
    240 	uint_fast8_t cmpend, minlen;
    241 	const uint8_t *lb = l, *rb = r;
    242 	int rc;
    243 
    244 	minlen = MIN(llen, rlen);
    245 
    246 	/* The field is missing from one region.  The shorter region is the
    247 	 * lesser region.
    248 	 */
    249 	if (fieldstart >= minlen)
    250 		return llen - rlen;
    251 
    252 	/* Two empty, present fields are always equal. */
    253 	if (fieldstart > fieldend)
    254 		return 0;
    255 
    256 	cmpend = MIN(fieldend, minlen);
    257 
    258 	rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart);
    259 
    260 	if (rc != 0)
    261 		return rc;
    262 	/* If one or both fields are truncated, then the shorter is the lesser
    263 	 * field.
    264 	 */
    265 	if (minlen < fieldend)
    266 		return llen - rlen;
    267 	/* Fields are full-length and equal.  The fields are equal. */
    268 	return 0;
    269 }
    270 
    271 uint8_t
    272 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen)
    273 {
    274 	return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]);
    275 }
    276 
    277 struct sockaddr *
    278 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type,
    279     const void *name, uint8_t namelen, const void *addr, uint8_t addrlen,
    280     int flags)
    281 {
    282 	struct sockaddr *sa;
    283 	socklen_t len;
    284 
    285 	len = sockaddr_dl_measure(namelen, addrlen);
    286 	sa = sockaddr_alloc(AF_LINK, len, flags);
    287 
    288 	if (sa == NULL)
    289 		return NULL;
    290 
    291 	if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen,
    292 	    addr, addrlen) == NULL) {
    293 		sockaddr_free(sa);
    294 		return NULL;
    295 	}
    296 
    297 	return sa;
    298 }
    299 
    300 struct sockaddr_dl *
    301 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex,
    302     uint8_t type, const void *name, uint8_t namelen, const void *addr,
    303     uint8_t addrlen)
    304 {
    305 	socklen_t len;
    306 
    307 	sdl->sdl_family = AF_LINK;
    308 	sdl->sdl_slen = 0;
    309 	len = sockaddr_dl_measure(namelen, addrlen);
    310 	if (len > socklen) {
    311 		sdl->sdl_len = socklen;
    312 #ifdef DIAGNOSTIC
    313 		printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
    314 		    socklen);
    315 #endif
    316 		return NULL;
    317 	}
    318 	sdl->sdl_len = len;
    319 	sdl->sdl_index = ifindex;
    320 	sdl->sdl_type = type;
    321 	memset(&sdl->sdl_data[0], 0, namelen + addrlen);
    322 	if (name != NULL) {
    323 		memcpy(&sdl->sdl_data[0], name, namelen);
    324 		sdl->sdl_nlen = namelen;
    325 	} else
    326 		sdl->sdl_nlen = 0;
    327 	if (addr != NULL) {
    328 		memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
    329 		sdl->sdl_alen = addrlen;
    330 	} else
    331 		sdl->sdl_alen = 0;
    332 	return sdl;
    333 }
    334 
    335 static int
    336 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
    337 {
    338 	int rc;
    339 	const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index);
    340 	const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen);
    341 	uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]);
    342 	const struct sockaddr_dl *sdl1, *sdl2;
    343 
    344 	sdl1 = satocsdl(sa1);
    345 	sdl2 = satocsdl(sa2);
    346 
    347 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    348 	    indexofs, nlenofs);
    349 
    350 	if (rc != 0)
    351 		return rc;
    352 
    353 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    354 	    dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen));
    355 
    356 	if (rc != 0)
    357 		return rc;
    358 
    359 	if (sdl1->sdl_nlen != sdl2->sdl_nlen)
    360 		return sdl1->sdl_nlen - sdl2->sdl_nlen;
    361 
    362 	dataofs += sdl1->sdl_nlen;
    363 
    364 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    365 	    dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen));
    366 
    367 	if (rc != 0)
    368 		return rc;
    369 
    370 	if (sdl1->sdl_alen != sdl2->sdl_alen)
    371 		return sdl1->sdl_alen - sdl2->sdl_alen;
    372 
    373 	dataofs += sdl1->sdl_alen;
    374 
    375 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    376 	    dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen));
    377 
    378 	if (sdl1->sdl_slen != sdl2->sdl_slen)
    379 		return sdl1->sdl_slen - sdl2->sdl_slen;
    380 
    381 	return sdl1->sdl_len - sdl2->sdl_len;
    382 }
    383 
    384 struct sockaddr_dl *
    385 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen,
    386     const void *addr, uint8_t addrlen)
    387 {
    388 	socklen_t len;
    389 
    390 	len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen);
    391 	if (len > socklen) {
    392 #ifdef DIAGNOSTIC
    393 		printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
    394 		    socklen);
    395 #endif
    396 		return NULL;
    397 	}
    398 	memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
    399 	sdl->sdl_alen = addrlen;
    400 	sdl->sdl_len = len;
    401 	return sdl;
    402 }
    403