1 /* 2 * Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved. 3 * Copyright (c) 2004-2008 Qing Li. All rights reserved. 4 * Copyright (c) 2008 Kip Macy. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_inet.h" 31 #include "opt_inet6.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/malloc.h> 36 #include <sys/mbuf.h> 37 #include <sys/syslog.h> 38 #include <sys/sysctl.h> 39 #include <sys/socket.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/mutex.h> 43 #include <sys/rwlock.h> 44 #include <sys/vimage.h> 45 46 #include <vm/uma.h> 47 48 #include <netinet/in.h> 49 #include <net/if_llatbl.h> 50 #include <net/if.h> 51 #include <net/if_dl.h> 52 #include <net/if_var.h> 53 #include <net/route.h> 54 #include <netinet/if_ether.h> 55 #include <netinet6/in6_var.h> 56 #include <netinet6/nd6.h> 57 58 MALLOC_DEFINE(M_LLTABLE, "lltable", "link level address tables"); 59 60 static SLIST_HEAD(, lltable) lltables = SLIST_HEAD_INITIALIZER(lltables); 61 62 extern void arprequest(struct ifnet *, struct in_addr *, struct in_addr *, 63 u_char *); 64 65 /* 66 * Dump arp state for a specific address family. 67 */ 68 int 69 lltable_sysctl_dumparp(int af, struct sysctl_req *wr) 70 { 71 struct lltable *llt; 72 int error = 0; 73 74 IFNET_RLOCK(); 75 SLIST_FOREACH(llt, &lltables, llt_link) { 76 if (llt->llt_af == af) { 77 error = llt->llt_dump(llt, wr); 78 if (error != 0) 79 goto done; 80 } 81 } 82 done: 83 IFNET_RUNLOCK(); 84 return (error); 85 } 86 87 /* 88 * Deletes an address from the address table. 89 * This function is called by the timer functions 90 * such as arptimer() and nd6_llinfo_timer(), and 91 * the caller does the locking. 92 */ 93 void 94 llentry_free(struct llentry *lle) 95 { 96 97 LLE_WLOCK_ASSERT(lle); 98 LIST_REMOVE(lle, lle_next); 99 100 if (lle->la_hold != NULL) 101 m_freem(lle->la_hold); 102 103 LLE_FREE_LOCKED(lle); 104 } 105 106 /* 107 * Update an llentry for address dst (equivalent to rtalloc for new-arp) 108 * Caller must pass in a valid struct llentry * 109 * 110 * if found the llentry * is returned referenced and unlocked 111 */ 112 int 113 llentry_update(struct llentry **llep, struct lltable *lt, 114 struct sockaddr *dst, struct ifnet *ifp) 115 { 116 struct llentry *la; 117 118 IF_AFDATA_RLOCK(ifp); 119 la = lla_lookup(lt, LLE_EXCLUSIVE, 120 (struct sockaddr *)dst); 121 IF_AFDATA_RUNLOCK(ifp); 122 if ((la == NULL) && 123 (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0) { 124 IF_AFDATA_WLOCK(ifp); 125 la = lla_lookup(lt, 126 (LLE_CREATE | LLE_EXCLUSIVE), 127 (struct sockaddr *)dst); 128 IF_AFDATA_WUNLOCK(ifp); 129 } 130 if (la != NULL && (*llep != la)) { 131 if (*llep != NULL) 132 LLE_FREE(*llep); 133 LLE_ADDREF(la); 134 LLE_WUNLOCK(la); 135 *llep = la; 136 } else if (la != NULL) 137 LLE_WUNLOCK(la); 138 139 if (la == NULL) 140 return (ENOENT); 141 142 return (0); 143 } 144 145 /* 146 * Free all entries from given table and free itself. 147 * Since lltables collects from all of the intefaces, 148 * the caller of this function must acquire IFNET_WLOCK(). 149 */ 150 void 151 lltable_free(struct lltable *llt) 152 { 153 struct llentry *lle, *next; 154 int i; 155 156 KASSERT(llt != NULL, ("%s: llt is NULL", __func__)); 157 158 IFNET_WLOCK(); 159 SLIST_REMOVE(&lltables, llt, lltable, llt_link); 160 IFNET_WUNLOCK(); 161 162 for (i=0; i < LLTBL_HASHTBL_SIZE; i++) { 163 LIST_FOREACH_SAFE(lle, &llt->lle_head[i], lle_next, next) { 164 165 callout_drain(&lle->la_timer); 166 LLE_WLOCK(lle); 167 llentry_free(lle); 168 } 169 } 170 171 free(llt, M_LLTABLE); 172 } 173 174 void 175 lltable_drain(int af) 176 { 177 struct lltable *llt; 178 struct llentry *lle; 179 register int i; 180 181 IFNET_RLOCK(); 182 SLIST_FOREACH(llt, &lltables, llt_link) { 183 if (llt->llt_af != af) 184 continue; 185 186 for (i=0; i < LLTBL_HASHTBL_SIZE; i++) { 187 LIST_FOREACH(lle, &llt->lle_head[i], lle_next) { 188 if (lle->la_hold) { 189 m_freem(lle->la_hold); 190 lle->la_hold = NULL; 191 } 192 } 193 } 194 } 195 IFNET_RUNLOCK(); 196 } 197 198 void 199 lltable_prefix_free(int af, struct sockaddr *prefix, struct sockaddr *mask) 200 { 201 struct lltable *llt; 202 203 IFNET_RLOCK(); 204 SLIST_FOREACH(llt, &lltables, llt_link) { 205 if (llt->llt_af != af) 206 continue; 207 208 llt->llt_prefix_free(llt, prefix, mask); 209 } 210 IFNET_RUNLOCK(); 211 } 212 213 214 215 /* 216 * Create a new lltable. 217 */ 218 struct lltable * 219 lltable_init(struct ifnet *ifp, int af) 220 { 221 struct lltable *llt; 222 register int i; 223 224 llt = malloc(sizeof(struct lltable), M_LLTABLE, M_WAITOK); 225 if (llt == NULL) 226 return (NULL); 227 228 llt->llt_af = af; 229 llt->llt_ifp = ifp; 230 for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) 231 LIST_INIT(&llt->lle_head[i]); 232 233 IFNET_WLOCK(); 234 SLIST_INSERT_HEAD(&lltables, llt, llt_link); 235 IFNET_WUNLOCK(); 236 237 return (llt); 238 } 239 240 /* 241 * Called in route_output when adding/deleting a route to an interface. 242 */ 243 int 244 lla_rt_output(struct rt_msghdr *rtm, struct rt_addrinfo *info) 245 { 246 struct sockaddr_dl *dl = 247 (struct sockaddr_dl *)info->rti_info[RTAX_GATEWAY]; 248 struct sockaddr *dst = (struct sockaddr *)info->rti_info[RTAX_DST]; 249 struct ifnet *ifp; 250 struct lltable *llt; 251 struct llentry *lle; 252 u_int laflags = 0, flags = 0; 253 int error = 0; 254 255 if (dl == NULL || dl->sdl_family != AF_LINK) { 256 log(LOG_INFO, "%s: invalid dl\n", __func__); 257 return EINVAL; 258 } 259 ifp = ifnet_byindex(dl->sdl_index); 260 if (ifp == NULL) { 261 log(LOG_INFO, "%s: invalid ifp (sdl_index %d)\n", 262 __func__, dl->sdl_index); 263 return EINVAL; 264 } 265 266 switch (rtm->rtm_type) { 267 case RTM_ADD: 268 if (rtm->rtm_flags & RTF_ANNOUNCE) { 269 flags |= LLE_PUB; 270 #ifdef INET 271 if (dst->sa_family == AF_INET && 272 ((struct sockaddr_inarp *)dst)->sin_other != 0) { 273 struct rtentry *rt = rtalloc1(dst, 0, 0); 274 if (rt == NULL || !(rt->rt_flags & RTF_HOST)) { 275 log(LOG_INFO, "%s: RTM_ADD publish " 276 "(proxy only) is invalid\n", 277 __func__); 278 if (rt) 279 RTFREE_LOCKED(rt); 280 return EINVAL; 281 } 282 RTFREE_LOCKED(rt); 283 284 flags |= LLE_PROXY; 285 } 286 #endif 287 } 288 flags |= LLE_CREATE; 289 break; 290 291 case RTM_DELETE: 292 flags |= LLE_DELETE; 293 break; 294 295 case RTM_CHANGE: 296 break; 297 298 default: 299 return EINVAL; /* XXX not implemented yet */ 300 } 301 302 /* XXX linked list may be too expensive */ 303 IFNET_RLOCK(); 304 SLIST_FOREACH(llt, &lltables, llt_link) { 305 if (llt->llt_af == dst->sa_family && 306 llt->llt_ifp == ifp) 307 break; 308 } 309 IFNET_RUNLOCK(); 310 KASSERT(llt != NULL, ("Yep, ugly hacks are bad\n")); 311 312 if (flags && LLE_CREATE) 313 flags |= LLE_EXCLUSIVE; 314 315 IF_AFDATA_LOCK(ifp); 316 lle = lla_lookup(llt, flags, dst); 317 IF_AFDATA_UNLOCK(ifp); 318 if (LLE_IS_VALID(lle)) { 319 if (flags & LLE_CREATE) { 320 /* 321 * If we delay the delete, then a subsequent 322 * "arp add" should look up this entry, reset the 323 * LLE_DELETED flag, and reset the expiration timer 324 */ 325 bcopy(LLADDR(dl), &lle->ll_addr, ifp->if_addrlen); 326 lle->la_flags |= LLE_VALID; 327 lle->la_flags &= ~LLE_DELETED; 328 #ifdef INET6 329 /* 330 * ND6 331 */ 332 if (dst->sa_family == AF_INET6) 333 lle->ln_state = ND6_LLINFO_REACHABLE; 334 #endif 335 /* 336 * NB: arp and ndp always set (RTF_STATIC | RTF_HOST) 337 */ 338 339 if (rtm->rtm_rmx.rmx_expire == 0) { 340 lle->la_flags |= LLE_STATIC; 341 lle->la_expire = 0; 342 } else 343 lle->la_expire = rtm->rtm_rmx.rmx_expire; 344 laflags = lle->la_flags; 345 LLE_WUNLOCK(lle); 346 #ifdef INET 347 /* gratuitous ARP */ 348 if ((laflags & LLE_PUB) && dst->sa_family == AF_INET) { 349 arprequest(ifp, 350 &((struct sockaddr_in *)dst)->sin_addr, 351 &((struct sockaddr_in *)dst)->sin_addr, 352 ((laflags & LLE_PROXY) ? 353 (u_char *)IF_LLADDR(ifp) : 354 (u_char *)LLADDR(dl))); 355 } 356 #endif 357 } else { 358 if (flags & LLE_EXCLUSIVE) 359 LLE_WUNLOCK(lle); 360 else 361 LLE_RUNLOCK(lle); 362 } 363 } else if ((lle == NULL) && (flags & LLE_DELETE)) 364 error = EINVAL; 365 366 367 return (error); 368 } 369