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 /* 199 * Create a new lltable. 200 */ 201 struct lltable * 202 lltable_init(struct ifnet *ifp, int af) 203 { 204 struct lltable *llt; 205 register int i; 206 207 llt = malloc(sizeof(struct lltable), M_LLTABLE, M_WAITOK); 208 if (llt == NULL) 209 return (NULL); 210 211 llt->llt_af = af; 212 llt->llt_ifp = ifp; 213 for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) 214 LIST_INIT(&llt->lle_head[i]); 215 216 IFNET_WLOCK(); 217 SLIST_INSERT_HEAD(&lltables, llt, llt_link); 218 IFNET_WUNLOCK(); 219 220 return (llt); 221 } 222 223 /* 224 * Called in route_output when adding/deleting a route to an interface. 225 */ 226 int 227 lla_rt_output(struct rt_msghdr *rtm, struct rt_addrinfo *info) 228 { 229 struct sockaddr_dl *dl = 230 (struct sockaddr_dl *)info->rti_info[RTAX_GATEWAY]; 231 struct sockaddr *dst = (struct sockaddr *)info->rti_info[RTAX_DST]; 232 struct ifnet *ifp; 233 struct lltable *llt; 234 struct llentry *lle; 235 u_int laflags = 0, flags = 0; 236 int error = 0; 237 238 if (dl == NULL || dl->sdl_family != AF_LINK) { 239 log(LOG_INFO, "%s: invalid dl\n", __func__); 240 return EINVAL; 241 } 242 ifp = ifnet_byindex(dl->sdl_index); 243 if (ifp == NULL) { 244 log(LOG_INFO, "%s: invalid ifp (sdl_index %d)\n", 245 __func__, dl->sdl_index); 246 return EINVAL; 247 } 248 249 switch (rtm->rtm_type) { 250 case RTM_ADD: 251 if (rtm->rtm_flags & RTF_ANNOUNCE) { 252 flags |= LLE_PUB; 253 #ifdef INET 254 if (dst->sa_family == AF_INET && 255 ((struct sockaddr_inarp *)dst)->sin_other != 0) { 256 struct rtentry *rt = rtalloc1(dst, 0, 0); 257 if (rt == NULL || !(rt->rt_flags & RTF_HOST)) { 258 log(LOG_INFO, "%s: RTM_ADD publish " 259 "(proxy only) is invalid\n", 260 __func__); 261 if (rt) 262 RTFREE_LOCKED(rt); 263 return EINVAL; 264 } 265 RTFREE_LOCKED(rt); 266 267 flags |= LLE_PROXY; 268 } 269 #endif 270 } 271 flags |= LLE_CREATE; 272 break; 273 274 case RTM_DELETE: 275 flags |= LLE_DELETE; 276 break; 277 278 case RTM_CHANGE: 279 break; 280 281 default: 282 return EINVAL; /* XXX not implemented yet */ 283 } 284 285 /* XXX linked list may be too expensive */ 286 IFNET_RLOCK(); 287 SLIST_FOREACH(llt, &lltables, llt_link) { 288 if (llt->llt_af == dst->sa_family && 289 llt->llt_ifp == ifp) 290 break; 291 } 292 IFNET_RUNLOCK(); 293 KASSERT(llt != NULL, ("Yep, ugly hacks are bad\n")); 294 295 if (flags && LLE_CREATE) 296 flags |= LLE_EXCLUSIVE; 297 298 IF_AFDATA_LOCK(ifp); 299 lle = lla_lookup(llt, flags, dst); 300 IF_AFDATA_UNLOCK(ifp); 301 if (LLE_IS_VALID(lle)) { 302 if (flags & LLE_CREATE) { 303 /* 304 * If we delay the delete, then a subsequent 305 * "arp add" should look up this entry, reset the 306 * LLE_DELETED flag, and reset the expiration timer 307 */ 308 bcopy(LLADDR(dl), &lle->ll_addr, ifp->if_addrlen); 309 lle->la_flags |= LLE_VALID; 310 lle->la_flags &= ~LLE_DELETED; 311 #ifdef INET6 312 /* 313 * ND6 314 */ 315 if (dst->sa_family == AF_INET6) 316 lle->ln_state = ND6_LLINFO_REACHABLE; 317 #endif 318 /* 319 * NB: arp and ndp always set (RTF_STATIC | RTF_HOST) 320 */ 321 322 if (rtm->rtm_rmx.rmx_expire == 0) { 323 lle->la_flags |= LLE_STATIC; 324 lle->la_expire = 0; 325 } else 326 lle->la_expire = rtm->rtm_rmx.rmx_expire; 327 laflags = lle->la_flags; 328 LLE_WUNLOCK(lle); 329 #ifdef INET 330 /* gratuitous ARP */ 331 if ((laflags & LLE_PUB) && dst->sa_family == AF_INET) { 332 arprequest(ifp, 333 &((struct sockaddr_in *)dst)->sin_addr, 334 &((struct sockaddr_in *)dst)->sin_addr, 335 ((laflags & LLE_PROXY) ? 336 (u_char *)IF_LLADDR(ifp) : 337 (u_char *)LLADDR(dl))); 338 } 339 #endif 340 } else { 341 if (flags & LLE_EXCLUSIVE) 342 LLE_WUNLOCK(lle); 343 else 344 LLE_RUNLOCK(lle); 345 } 346 } else if ((lle == NULL) && (flags & LLE_DELETE)) 347 error = EINVAL; 348 349 350 return (error); 351 } 352