Home | History | Annotate | Line # | Download | only in net
link_proto.c revision 1.12 
      1 /*	$NetBSD: link_proto.c,v 1.12 2014/07/01 05:49:18 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 1.12 2014/07/01 05:49:18 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_ioctl(struct socket *, u_long, void *, struct ifnet *);
     54 static int link_usrreq(struct socket *, int, struct mbuf *, struct mbuf *,
     55     struct mbuf *, struct lwp *);
     56 static void link_init(void);
     57 
     58 /*
     59  * Definitions of protocols supported in the link-layer domain.
     60  */
     61 
     62 DOMAIN_DEFINE(linkdomain);	/* forward define and add to link set */
     63 
     64 static const struct pr_usrreqs link_usrreqs = {
     65 	.pr_attach	= link_attach,
     66 	.pr_detach	= link_detach,
     67 	.pr_ioctl	= link_ioctl,
     68 	.pr_generic	= link_usrreq,
     69 };
     70 
     71 const struct protosw linksw[] = {
     72 	{	.pr_type = SOCK_DGRAM,
     73 		.pr_domain = &linkdomain,
     74 		.pr_protocol = 0,	/* XXX */
     75 		.pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
     76 		.pr_input = NULL,
     77 		.pr_ctlinput = NULL,
     78 		.pr_ctloutput = NULL,
     79 		.pr_usrreqs = &link_usrreqs,
     80 		.pr_init = link_init,
     81 	},
     82 };
     83 
     84 struct domain linkdomain = {
     85 	.dom_family = AF_LINK,
     86 	.dom_name = "link",
     87 	.dom_externalize = NULL,
     88 	.dom_dispose = NULL,
     89 	.dom_protosw = linksw,
     90 	.dom_protoswNPROTOSW = &linksw[__arraycount(linksw)],
     91 	.dom_sockaddr_cmp = sockaddr_dl_cmp
     92 };
     93 
     94 static void
     95 link_init(void)
     96 {
     97 	return;
     98 }
     99 
    100 static int
    101 link_control(struct socket *so, unsigned long cmd, void *data,
    102     struct ifnet *ifp)
    103 {
    104 	int error, s;
    105 	bool isactive, mkactive;
    106 	struct if_laddrreq *iflr;
    107 	union {
    108 		struct sockaddr sa;
    109 		struct sockaddr_dl sdl;
    110 		struct sockaddr_storage ss;
    111 	} u;
    112 	struct ifaddr *ifa;
    113 	const struct sockaddr_dl *asdl, *nsdl;
    114 
    115 	switch (cmd) {
    116 	case SIOCALIFADDR:
    117 	case SIOCDLIFADDR:
    118 	case SIOCGLIFADDR:
    119 		iflr = data;
    120 
    121 		if (iflr->addr.ss_family != AF_LINK)
    122 			return EINVAL;
    123 
    124 		asdl = satocsdl(sstocsa(&iflr->addr));
    125 
    126 		if (asdl->sdl_alen != ifp->if_addrlen)
    127 			return EINVAL;
    128 
    129 		if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), ifp->if_index,
    130 		    ifp->if_type, ifp->if_xname, strlen(ifp->if_xname),
    131 		    CLLADDR(asdl), asdl->sdl_alen) == NULL)
    132 			return EINVAL;
    133 
    134 		if ((iflr->flags & IFLR_PREFIX) == 0)
    135 			;
    136 		else if (iflr->prefixlen != NBBY * ifp->if_addrlen)
    137 			return EINVAL;	/* XXX match with prefix */
    138 
    139 		error = 0;
    140 
    141 		s = splnet();
    142 
    143 		IFADDR_FOREACH(ifa, ifp) {
    144 			if (sockaddr_cmp(&u.sa, ifa->ifa_addr) == 0)
    145 				break;
    146 		}
    147 
    148 		switch (cmd) {
    149 		case SIOCGLIFADDR:
    150 			if ((iflr->flags & IFLR_PREFIX) == 0) {
    151 				IFADDR_FOREACH(ifa, ifp) {
    152 					if (ifa->ifa_addr->sa_family == AF_LINK)
    153 						break;
    154 				}
    155 			}
    156 			if (ifa == NULL) {
    157 				error = EADDRNOTAVAIL;
    158 				break;
    159 			}
    160 
    161 			if (ifa == ifp->if_dl)
    162 				iflr->flags = IFLR_ACTIVE;
    163 			else
    164 				iflr->flags = 0;
    165 
    166 			if (ifa == ifp->if_hwdl)
    167 				iflr->flags |= IFLR_FACTORY;
    168 
    169 			sockaddr_copy(sstosa(&iflr->addr), sizeof(iflr->addr),
    170 			    ifa->ifa_addr);
    171 
    172 			break;
    173 		case SIOCDLIFADDR:
    174 			if (ifa == NULL)
    175 				error = EADDRNOTAVAIL;
    176 			else if (ifa == ifp->if_dl || ifa == ifp->if_hwdl)
    177 				error = EBUSY;
    178 			else {
    179 				/* TBD routing socket */
    180 				rt_newaddrmsg(RTM_DELETE, ifa, 0, NULL);
    181 				ifa_remove(ifp, ifa);
    182 			}
    183 			break;
    184 		case SIOCALIFADDR:
    185 			if (ifa != NULL)
    186 				;
    187 			else if ((ifa = if_dl_create(ifp, &nsdl)) == NULL) {
    188 				error = ENOMEM;
    189 				break;
    190 			} else {
    191 				sockaddr_copy(ifa->ifa_addr,
    192 				    ifa->ifa_addr->sa_len, &u.sa);
    193 				ifa_insert(ifp, ifa);
    194 				rt_newaddrmsg(RTM_ADD, ifa, 0, NULL);
    195 			}
    196 
    197 			mkactive = (iflr->flags & IFLR_ACTIVE) != 0;
    198 			isactive = (ifa == ifp->if_dl);
    199 
    200 			if (!isactive && mkactive) {
    201 				if_activate_sadl(ifp, ifa, nsdl);
    202 				rt_newaddrmsg(RTM_CHANGE, ifa, 0, NULL);
    203 				error = ENETRESET;
    204 			}
    205 			break;
    206 		}
    207 		splx(s);
    208 		if (error != ENETRESET)
    209 			return error;
    210 		else if ((ifp->if_flags & IFF_RUNNING) != 0)
    211 			return (*ifp->if_init)(ifp);
    212 		else
    213 			return 0;
    214 	default:
    215 		return ENOTTY;
    216 	}
    217 }
    218 
    219 static int
    220 link_attach(struct socket *so, int proto)
    221 {
    222 	sosetlock(so);
    223 	KASSERT(solocked(so));
    224 	return 0;
    225 }
    226 
    227 static void
    228 link_detach(struct socket *so)
    229 {
    230 	KASSERT(solocked(so));
    231 	sofree(so);
    232 }
    233 
    234 static int
    235 link_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
    236 {
    237 	return link_control(so, cmd, nam, ifp);
    238 }
    239 
    240 static int
    241 link_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
    242 	struct mbuf *control, struct lwp *l)
    243 {
    244 	KASSERT(req != PRU_ATTACH);
    245 	KASSERT(req != PRU_DETACH);
    246 	KASSERT(req != PRU_CONTROL);
    247 
    248 	return EOPNOTSUPP;
    249 }
    250 
    251 /* Compare the field at byte offsets [fieldstart, fieldend) in
    252  * two memory regions, [l, l + llen) and [r, r + llen).
    253  */
    254 static inline int
    255 submemcmp(const void *l, const void *r,
    256     const uint_fast8_t llen, const uint_fast8_t rlen,
    257     const uint_fast8_t fieldstart, const uint_fast8_t fieldend)
    258 {
    259 	uint_fast8_t cmpend, minlen;
    260 	const uint8_t *lb = l, *rb = r;
    261 	int rc;
    262 
    263 	minlen = MIN(llen, rlen);
    264 
    265 	/* The field is missing from one region.  The shorter region is the
    266 	 * lesser region.
    267 	 */
    268 	if (fieldstart >= minlen)
    269 		return llen - rlen;
    270 
    271 	/* Two empty, present fields are always equal. */
    272 	if (fieldstart > fieldend)
    273 		return 0;
    274 
    275 	cmpend = MIN(fieldend, minlen);
    276 
    277 	rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart);
    278 
    279 	if (rc != 0)
    280 		return rc;
    281 	/* If one or both fields are truncated, then the shorter is the lesser
    282 	 * field.
    283 	 */
    284 	if (minlen < fieldend)
    285 		return llen - rlen;
    286 	/* Fields are full-length and equal.  The fields are equal. */
    287 	return 0;
    288 }
    289 
    290 uint8_t
    291 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen)
    292 {
    293 	return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]);
    294 }
    295 
    296 struct sockaddr *
    297 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type,
    298     const void *name, uint8_t namelen, const void *addr, uint8_t addrlen,
    299     int flags)
    300 {
    301 	struct sockaddr *sa;
    302 	socklen_t len;
    303 
    304 	len = sockaddr_dl_measure(namelen, addrlen);
    305 	sa = sockaddr_alloc(AF_LINK, len, flags);
    306 
    307 	if (sa == NULL)
    308 		return NULL;
    309 
    310 	if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen,
    311 	    addr, addrlen) == NULL) {
    312 		sockaddr_free(sa);
    313 		return NULL;
    314 	}
    315 
    316 	return sa;
    317 }
    318 
    319 struct sockaddr_dl *
    320 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex,
    321     uint8_t type, const void *name, uint8_t namelen, const void *addr,
    322     uint8_t addrlen)
    323 {
    324 	socklen_t len;
    325 
    326 	sdl->sdl_family = AF_LINK;
    327 	sdl->sdl_slen = 0;
    328 	len = sockaddr_dl_measure(namelen, addrlen);
    329 	if (len > socklen) {
    330 		sdl->sdl_len = socklen;
    331 #ifdef DIAGNOSTIC
    332 		printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
    333 		    socklen);
    334 #endif
    335 		return NULL;
    336 	}
    337 	sdl->sdl_len = len;
    338 	sdl->sdl_index = ifindex;
    339 	sdl->sdl_type = type;
    340 	memset(&sdl->sdl_data[0], 0, namelen + addrlen);
    341 	if (name != NULL) {
    342 		memcpy(&sdl->sdl_data[0], name, namelen);
    343 		sdl->sdl_nlen = namelen;
    344 	} else
    345 		sdl->sdl_nlen = 0;
    346 	if (addr != NULL) {
    347 		memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
    348 		sdl->sdl_alen = addrlen;
    349 	} else
    350 		sdl->sdl_alen = 0;
    351 	return sdl;
    352 }
    353 
    354 static int
    355 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
    356 {
    357 	int rc;
    358 	const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index);
    359 	const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen);
    360 	uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]);
    361 	const struct sockaddr_dl *sdl1, *sdl2;
    362 
    363 	sdl1 = satocsdl(sa1);
    364 	sdl2 = satocsdl(sa2);
    365 
    366 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    367 	    indexofs, nlenofs);
    368 
    369 	if (rc != 0)
    370 		return rc;
    371 
    372 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    373 	    dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen));
    374 
    375 	if (rc != 0)
    376 		return rc;
    377 
    378 	if (sdl1->sdl_nlen != sdl2->sdl_nlen)
    379 		return sdl1->sdl_nlen - sdl2->sdl_nlen;
    380 
    381 	dataofs += sdl1->sdl_nlen;
    382 
    383 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    384 	    dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen));
    385 
    386 	if (rc != 0)
    387 		return rc;
    388 
    389 	if (sdl1->sdl_alen != sdl2->sdl_alen)
    390 		return sdl1->sdl_alen - sdl2->sdl_alen;
    391 
    392 	dataofs += sdl1->sdl_alen;
    393 
    394 	rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len,
    395 	    dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen));
    396 
    397 	if (sdl1->sdl_slen != sdl2->sdl_slen)
    398 		return sdl1->sdl_slen - sdl2->sdl_slen;
    399 
    400 	return sdl1->sdl_len - sdl2->sdl_len;
    401 }
    402 
    403 struct sockaddr_dl *
    404 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen,
    405     const void *addr, uint8_t addrlen)
    406 {
    407 	socklen_t len;
    408 
    409 	len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen);
    410 	if (len > socklen) {
    411 #ifdef DIAGNOSTIC
    412 		printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len,
    413 		    socklen);
    414 #endif
    415 		return NULL;
    416 	}
    417 	memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen);
    418 	sdl->sdl_alen = addrlen;
    419 	sdl->sdl_len = len;
    420 	return sdl;
    421 }
    422