1 /* $NetBSD: link_proto.c,v 1.9 2014/05/19 02:51:24 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 1.9 2014/05/19 02:51:24 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_attach(struct socket *, int); 52 static void link_detach(struct socket *); 53 static int link_usrreq(struct socket *, int, struct mbuf *, struct mbuf *, 54 struct mbuf *, struct lwp *); 55 static void link_init(void); 56 57 /* 58 * Definitions of protocols supported in the link-layer domain. 59 */ 60 61 DOMAIN_DEFINE(linkdomain); /* forward define and add to link set */ 62 63 static const struct pr_usrreqs link_usrreqs = { 64 .pr_attach = link_attach, 65 .pr_detach = link_detach, 66 .pr_generic = link_usrreq, 67 }; 68 69 const struct protosw linksw[] = { 70 { .pr_type = SOCK_DGRAM, 71 .pr_domain = &linkdomain, 72 .pr_protocol = 0, /* XXX */ 73 .pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF, 74 .pr_input = NULL, 75 .pr_ctlinput = NULL, 76 .pr_ctloutput = NULL, 77 .pr_usrreqs = &link_usrreqs, 78 .pr_init = link_init, 79 }, 80 }; 81 82 struct domain linkdomain = { 83 .dom_family = AF_LINK, 84 .dom_name = "link", 85 .dom_externalize = NULL, 86 .dom_dispose = NULL, 87 .dom_protosw = linksw, 88 .dom_protoswNPROTOSW = &linksw[__arraycount(linksw)], 89 .dom_sockaddr_cmp = sockaddr_dl_cmp 90 }; 91 92 static void 93 link_init(void) 94 { 95 return; 96 } 97 98 static int 99 link_control(struct socket *so, unsigned long cmd, void *data, 100 struct ifnet *ifp, struct lwp *l) 101 { 102 int error, s; 103 bool isactive, mkactive; 104 struct if_laddrreq *iflr; 105 union { 106 struct sockaddr sa; 107 struct sockaddr_dl sdl; 108 struct sockaddr_storage ss; 109 } u; 110 struct ifaddr *ifa; 111 const struct sockaddr_dl *asdl, *nsdl; 112 113 switch (cmd) { 114 case SIOCALIFADDR: 115 case SIOCDLIFADDR: 116 case SIOCGLIFADDR: 117 iflr = data; 118 119 if (iflr->addr.ss_family != AF_LINK) 120 return EINVAL; 121 122 asdl = satocsdl(sstocsa(&iflr->addr)); 123 124 if (asdl->sdl_alen != ifp->if_addrlen) 125 return EINVAL; 126 127 if (sockaddr_dl_init(&u.sdl, sizeof(u.ss), ifp->if_index, 128 ifp->if_type, ifp->if_xname, strlen(ifp->if_xname), 129 CLLADDR(asdl), asdl->sdl_alen) == NULL) 130 return EINVAL; 131 132 if ((iflr->flags & IFLR_PREFIX) == 0) 133 ; 134 else if (iflr->prefixlen != NBBY * ifp->if_addrlen) 135 return EINVAL; /* XXX match with prefix */ 136 137 error = 0; 138 139 s = splnet(); 140 141 IFADDR_FOREACH(ifa, ifp) { 142 if (sockaddr_cmp(&u.sa, ifa->ifa_addr) == 0) 143 break; 144 } 145 146 switch (cmd) { 147 case SIOCGLIFADDR: 148 if ((iflr->flags & IFLR_PREFIX) == 0) { 149 IFADDR_FOREACH(ifa, ifp) { 150 if (ifa->ifa_addr->sa_family == AF_LINK) 151 break; 152 } 153 } 154 if (ifa == NULL) { 155 error = EADDRNOTAVAIL; 156 break; 157 } 158 159 if (ifa == ifp->if_dl) 160 iflr->flags = IFLR_ACTIVE; 161 else 162 iflr->flags = 0; 163 164 if (ifa == ifp->if_hwdl) 165 iflr->flags |= IFLR_FACTORY; 166 167 sockaddr_copy(sstosa(&iflr->addr), sizeof(iflr->addr), 168 ifa->ifa_addr); 169 170 break; 171 case SIOCDLIFADDR: 172 if (ifa == NULL) 173 error = EADDRNOTAVAIL; 174 else if (ifa == ifp->if_dl || ifa == ifp->if_hwdl) 175 error = EBUSY; 176 else { 177 /* TBD routing socket */ 178 rt_newaddrmsg(RTM_DELETE, ifa, 0, NULL); 179 ifa_remove(ifp, ifa); 180 } 181 break; 182 case SIOCALIFADDR: 183 if (ifa != NULL) 184 ; 185 else if ((ifa = if_dl_create(ifp, &nsdl)) == NULL) { 186 error = ENOMEM; 187 break; 188 } else { 189 sockaddr_copy(ifa->ifa_addr, 190 ifa->ifa_addr->sa_len, &u.sa); 191 ifa_insert(ifp, ifa); 192 rt_newaddrmsg(RTM_ADD, ifa, 0, NULL); 193 } 194 195 mkactive = (iflr->flags & IFLR_ACTIVE) != 0; 196 isactive = (ifa == ifp->if_dl); 197 198 if (!isactive && mkactive) { 199 if_activate_sadl(ifp, ifa, nsdl); 200 rt_newaddrmsg(RTM_CHANGE, ifa, 0, NULL); 201 error = ENETRESET; 202 } 203 break; 204 } 205 splx(s); 206 if (error != ENETRESET) 207 return error; 208 else if ((ifp->if_flags & IFF_RUNNING) != 0) 209 return (*ifp->if_init)(ifp); 210 else 211 return 0; 212 default: 213 return ENOTTY; 214 } 215 } 216 217 static int 218 link_attach(struct socket *so, int proto) 219 { 220 sosetlock(so); 221 KASSERT(solocked(so)); 222 return 0; 223 } 224 225 static void 226 link_detach(struct socket *so) 227 { 228 KASSERT(solocked(so)); 229 sofree(so); 230 } 231 232 static int 233 link_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, 234 struct mbuf *control, struct lwp *l) 235 { 236 KASSERT(req != PRU_ATTACH); 237 KASSERT(req != PRU_DETACH); 238 239 switch (req) { 240 case PRU_CONTROL: 241 return link_control(so, (unsigned long)m, nam, 242 (struct ifnet *)control, l); 243 default: 244 return EOPNOTSUPP; 245 } 246 } 247 248 /* Compare the field at byte offsets [fieldstart, fieldend) in 249 * two memory regions, [l, l + llen) and [r, r + llen). 250 */ 251 static inline int 252 submemcmp(const void *l, const void *r, 253 const uint_fast8_t llen, const uint_fast8_t rlen, 254 const uint_fast8_t fieldstart, const uint_fast8_t fieldend) 255 { 256 uint_fast8_t cmpend, minlen; 257 const uint8_t *lb = l, *rb = r; 258 int rc; 259 260 minlen = MIN(llen, rlen); 261 262 /* The field is missing from one region. The shorter region is the 263 * lesser region. 264 */ 265 if (fieldstart >= minlen) 266 return llen - rlen; 267 268 /* Two empty, present fields are always equal. */ 269 if (fieldstart > fieldend) 270 return 0; 271 272 cmpend = MIN(fieldend, minlen); 273 274 rc = memcmp(&lb[fieldstart], &rb[fieldstart], cmpend - fieldstart); 275 276 if (rc != 0) 277 return rc; 278 /* If one or both fields are truncated, then the shorter is the lesser 279 * field. 280 */ 281 if (minlen < fieldend) 282 return llen - rlen; 283 /* Fields are full-length and equal. The fields are equal. */ 284 return 0; 285 } 286 287 uint8_t 288 sockaddr_dl_measure(uint8_t namelen, uint8_t addrlen) 289 { 290 return offsetof(struct sockaddr_dl, sdl_data[namelen + addrlen]); 291 } 292 293 struct sockaddr * 294 sockaddr_dl_alloc(uint16_t ifindex, uint8_t type, 295 const void *name, uint8_t namelen, const void *addr, uint8_t addrlen, 296 int flags) 297 { 298 struct sockaddr *sa; 299 socklen_t len; 300 301 len = sockaddr_dl_measure(namelen, addrlen); 302 sa = sockaddr_alloc(AF_LINK, len, flags); 303 304 if (sa == NULL) 305 return NULL; 306 307 if (sockaddr_dl_init(satosdl(sa), len, ifindex, type, name, namelen, 308 addr, addrlen) == NULL) { 309 sockaddr_free(sa); 310 return NULL; 311 } 312 313 return sa; 314 } 315 316 struct sockaddr_dl * 317 sockaddr_dl_init(struct sockaddr_dl *sdl, socklen_t socklen, uint16_t ifindex, 318 uint8_t type, const void *name, uint8_t namelen, const void *addr, 319 uint8_t addrlen) 320 { 321 socklen_t len; 322 323 sdl->sdl_family = AF_LINK; 324 sdl->sdl_slen = 0; 325 len = sockaddr_dl_measure(namelen, addrlen); 326 if (len > socklen) { 327 sdl->sdl_len = socklen; 328 #ifdef DIAGNOSTIC 329 printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len, 330 socklen); 331 #endif 332 return NULL; 333 } 334 sdl->sdl_len = len; 335 sdl->sdl_index = ifindex; 336 sdl->sdl_type = type; 337 memset(&sdl->sdl_data[0], 0, namelen + addrlen); 338 if (name != NULL) { 339 memcpy(&sdl->sdl_data[0], name, namelen); 340 sdl->sdl_nlen = namelen; 341 } else 342 sdl->sdl_nlen = 0; 343 if (addr != NULL) { 344 memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen); 345 sdl->sdl_alen = addrlen; 346 } else 347 sdl->sdl_alen = 0; 348 return sdl; 349 } 350 351 static int 352 sockaddr_dl_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2) 353 { 354 int rc; 355 const uint_fast8_t indexofs = offsetof(struct sockaddr_dl, sdl_index); 356 const uint_fast8_t nlenofs = offsetof(struct sockaddr_dl, sdl_nlen); 357 uint_fast8_t dataofs = offsetof(struct sockaddr_dl, sdl_data[0]); 358 const struct sockaddr_dl *sdl1, *sdl2; 359 360 sdl1 = satocsdl(sa1); 361 sdl2 = satocsdl(sa2); 362 363 rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len, 364 indexofs, nlenofs); 365 366 if (rc != 0) 367 return rc; 368 369 rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len, 370 dataofs, dataofs + MIN(sdl1->sdl_nlen, sdl2->sdl_nlen)); 371 372 if (rc != 0) 373 return rc; 374 375 if (sdl1->sdl_nlen != sdl2->sdl_nlen) 376 return sdl1->sdl_nlen - sdl2->sdl_nlen; 377 378 dataofs += sdl1->sdl_nlen; 379 380 rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len, 381 dataofs, dataofs + MIN(sdl1->sdl_alen, sdl2->sdl_alen)); 382 383 if (rc != 0) 384 return rc; 385 386 if (sdl1->sdl_alen != sdl2->sdl_alen) 387 return sdl1->sdl_alen - sdl2->sdl_alen; 388 389 dataofs += sdl1->sdl_alen; 390 391 rc = submemcmp(sdl1, sdl2, sdl1->sdl_len, sdl2->sdl_len, 392 dataofs, dataofs + MIN(sdl1->sdl_slen, sdl2->sdl_slen)); 393 394 if (sdl1->sdl_slen != sdl2->sdl_slen) 395 return sdl1->sdl_slen - sdl2->sdl_slen; 396 397 return sdl1->sdl_len - sdl2->sdl_len; 398 } 399 400 struct sockaddr_dl * 401 sockaddr_dl_setaddr(struct sockaddr_dl *sdl, socklen_t socklen, 402 const void *addr, uint8_t addrlen) 403 { 404 socklen_t len; 405 406 len = sockaddr_dl_measure(sdl->sdl_nlen, addrlen); 407 if (len > socklen) { 408 #ifdef DIAGNOSTIC 409 printf("%s: too long: %" PRIu8 " > %" PRIu8 "\n", __func__, len, 410 socklen); 411 #endif 412 return NULL; 413 } 414 memcpy(&sdl->sdl_data[sdl->sdl_nlen], addr, addrlen); 415 sdl->sdl_alen = addrlen; 416 sdl->sdl_len = len; 417 return sdl; 418 } 419