1/*- 2 * Copyright (c) 2004-2009 Robert N. M. Watson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * Copyright (c) 1990, 1994 Regents of The University of Michigan. 27 * 28 * Permission to use, copy, modify, and distribute this software and 29 * its documentation for any purpose and without fee is hereby granted, 30 * provided that the above copyright notice appears in all copies and 31 * that both that copyright notice and this permission notice appear 32 * in supporting documentation, and that the name of The University 33 * of Michigan not be used in advertising or publicity pertaining to 34 * distribution of the software without specific, written prior 35 * permission. This software is supplied as is without expressed or 36 * implied warranties of any kind. 37 * 38 * This product includes software developed by the University of 39 * California, Berkeley and its contributors. 40 * 41 * Research Systems Unix Group 42 * The University of Michigan 43 * c/o Wesley Craig 44 * 535 W. William Street 45 * Ann Arbor, Michigan 46 * +1-313-764-2278 47 * netatalk@umich.edu 48 * 49 * $FreeBSD$ 50 */ 51 52#include <sys/param.h> 53#include <sys/kernel.h> 54#include <sys/lock.h> 55#include <sys/mbuf.h> 56#include <sys/signalvar.h> 57#include <sys/socket.h> 58#include <sys/socketvar.h> 59#include <sys/sx.h> 60#include <sys/systm.h> 61#include <net/if.h> 62#include <net/route.h> 63 64#include <netatalk/at.h> 65#include <netatalk/at_var.h> 66#include <netatalk/ddp.h> 67#include <netatalk/ddp_var.h> 68#include <netatalk/ddp_pcb.h> 69#include <netatalk/at_extern.h> 70 71#include <security/mac/mac_framework.h> 72 73static volatile int ddp_forward = 1; 74static volatile int ddp_firewall = 0; 75static struct ddpstat ddpstat; 76 77static struct route forwro; 78 79static void ddp_input(struct mbuf *, struct ifnet *, struct elaphdr *, int); 80 81/* 82 * Could probably merge these two code segments a little better... 83 */ 84void 85at2intr(struct mbuf *m) 86{ 87 88 /* 89 * Phase 2 packet handling . 90 */ 91 ddp_input(m, m->m_pkthdr.rcvif, NULL, 2); 92} 93 94void 95at1intr(struct mbuf *m) 96{ 97 struct elaphdr *elhp, elh; 98 99 /* 100 * Phase 1 packet handling 101 */ 102 if (m->m_len < SZ_ELAPHDR && ((m = m_pullup(m, SZ_ELAPHDR)) == 103 NULL)) { 104 ddpstat.ddps_tooshort++; 105 return; 106 } 107 108 /* 109 * This seems a little dubious, but I don't know phase 1 so leave it. 110 */ 111 elhp = mtod(m, struct elaphdr *); 112 m_adj(m, SZ_ELAPHDR); 113 114 if (elhp->el_type != ELAP_DDPEXTEND) { 115 bcopy((caddr_t)elhp, (caddr_t)&elh, SZ_ELAPHDR); 116 ddp_input(m, m->m_pkthdr.rcvif, &elh, 1); 117 } else 118 ddp_input(m, m->m_pkthdr.rcvif, NULL, 1); 119} 120 121static void 122ddp_input(struct mbuf *m, struct ifnet *ifp, struct elaphdr *elh, int phase) 123{ 124 struct sockaddr_at from, to; 125 struct ddpshdr *dsh, ddps; 126 struct at_ifaddr *aa; 127 struct ddpehdr *deh = NULL, ddpe; 128 struct ddpcb *ddp; 129 int dlen, mlen; 130 u_short cksum = 0; 131 132 bzero((caddr_t)&from, sizeof(struct sockaddr_at)); 133 bzero((caddr_t)&to, sizeof(struct sockaddr_at)); 134 if (elh != NULL) { 135 /* 136 * Extract the information in the short header. Network 137 * information is defaulted to ATADDR_ANYNET and node 138 * information comes from the elh info. We must be phase 1. 139 */ 140 ddpstat.ddps_short++; 141 142 if (m->m_len < sizeof(struct ddpshdr) && 143 ((m = m_pullup(m, sizeof(struct ddpshdr))) == NULL)) { 144 ddpstat.ddps_tooshort++; 145 return; 146 } 147 148 dsh = mtod(m, struct ddpshdr *); 149 bcopy((caddr_t)dsh, (caddr_t)&ddps, sizeof(struct ddpshdr)); 150 ddps.dsh_bytes = ntohl(ddps.dsh_bytes); 151 dlen = ddps.dsh_len; 152 153 to.sat_addr.s_net = ATADDR_ANYNET; 154 to.sat_addr.s_node = elh->el_dnode; 155 to.sat_port = ddps.dsh_dport; 156 from.sat_addr.s_net = ATADDR_ANYNET; 157 from.sat_addr.s_node = elh->el_snode; 158 from.sat_port = ddps.dsh_sport; 159 160 /* 161 * Make sure that we point to the phase1 ifaddr info and that 162 * it's valid for this packet. 163 */ 164 AT_IFADDR_RLOCK(); 165 TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) { 166 if ((aa->aa_ifp == ifp) 167 && ((aa->aa_flags & AFA_PHASE2) == 0) 168 && ((to.sat_addr.s_node == 169 AA_SAT(aa)->sat_addr.s_node) || 170 (to.sat_addr.s_node == ATADDR_BCAST))) 171 break; 172 } 173 /* 174 * maybe we got a broadcast not meant for us.. ditch it. 175 */ 176 if (aa == NULL) { 177 AT_IFADDR_RUNLOCK(); 178 m_freem(m); 179 return; 180 } 181 } else { 182 /* 183 * There was no 'elh' passed on. This could still be either 184 * phase1 or phase2. We have a long header, but we may be 185 * running on a phase 1 net. Extract out all the info 186 * regarding this packet's src & dst. 187 */ 188 ddpstat.ddps_long++; 189 190 if (m->m_len < sizeof(struct ddpehdr) && 191 ((m = m_pullup(m, sizeof(struct ddpehdr))) == NULL)) { 192 AT_IFADDR_RUNLOCK(); 193 ddpstat.ddps_tooshort++; 194 return; 195 } 196 197 deh = mtod(m, struct ddpehdr *); 198 bcopy((caddr_t)deh, (caddr_t)&ddpe, sizeof(struct ddpehdr)); 199 ddpe.deh_bytes = ntohl(ddpe.deh_bytes); 200 dlen = ddpe.deh_len; 201 202 if ((cksum = ddpe.deh_sum) == 0) 203 ddpstat.ddps_nosum++; 204 205 from.sat_addr.s_net = ddpe.deh_snet; 206 from.sat_addr.s_node = ddpe.deh_snode; 207 from.sat_port = ddpe.deh_sport; 208 to.sat_addr.s_net = ddpe.deh_dnet; 209 to.sat_addr.s_node = ddpe.deh_dnode; 210 to.sat_port = ddpe.deh_dport; 211 212 AT_IFADDR_RLOCK(); 213 if (to.sat_addr.s_net == ATADDR_ANYNET) { 214 /* 215 * The TO address doesn't specify a net, so by 216 * definition it's for this net. Try find ifaddr 217 * info with the right phase, the right interface, 218 * and either to our node, a broadcast, or looped 219 * back (though that SHOULD be covered in the other 220 * cases). 221 * 222 * XXX If we have multiple interfaces, then the first 223 * with this node number will match (which may NOT be 224 * what we want, but it's probably safe in 99.999% of 225 * cases. 226 */ 227 TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) { 228 if (phase == 1 && (aa->aa_flags & 229 AFA_PHASE2)) 230 continue; 231 if (phase == 2 && (aa->aa_flags & 232 AFA_PHASE2) == 0) 233 continue; 234 if ((aa->aa_ifp == ifp) && 235 ((to.sat_addr.s_node == 236 AA_SAT(aa)->sat_addr.s_node) || 237 (to.sat_addr.s_node == ATADDR_BCAST) || 238 (ifp->if_flags & IFF_LOOPBACK))) 239 break; 240 } 241 } else { 242 /* 243 * A destination network was given. We just try to 244 * find which ifaddr info matches it. 245 */ 246 TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) { 247 /* 248 * This is a kludge. Accept packets that are 249 * for any router on a local netrange. 250 */ 251 if (to.sat_addr.s_net == aa->aa_firstnet && 252 to.sat_addr.s_node == 0) 253 break; 254 /* 255 * Don't use ifaddr info for which we are 256 * totally outside the netrange, and it's not 257 * a startup packet. Startup packets are 258 * always implicitly allowed on to the next 259 * test. 260 */ 261 if (((ntohs(to.sat_addr.s_net) < 262 ntohs(aa->aa_firstnet)) || 263 (ntohs(to.sat_addr.s_net) > 264 ntohs(aa->aa_lastnet))) && 265 ((ntohs(to.sat_addr.s_net) < 0xff00) || 266 (ntohs(to.sat_addr.s_net) > 0xfffe))) 267 continue; 268 269 /* 270 * Don't record a match either if we just 271 * don't have a match in the node address. 272 * This can have if the interface is in 273 * promiscuous mode for example. 274 */ 275 if ((to.sat_addr.s_node != 276 AA_SAT(aa)->sat_addr.s_node) && 277 (to.sat_addr.s_node != ATADDR_BCAST)) 278 continue; 279 break; 280 } 281 } 282 } 283 if (aa != NULL) 284 ifa_ref(&aa->aa_ifa); 285 AT_IFADDR_RUNLOCK(); 286 287 /* 288 * Adjust the length, removing any padding that may have been added 289 * at a link layer. We do this before we attempt to forward a 290 * packet, possibly on a different media. 291 */ 292 mlen = m->m_pkthdr.len; 293 if (mlen < dlen) { 294 ddpstat.ddps_toosmall++; 295 goto out; 296 } 297 if (mlen > dlen) 298 m_adj(m, dlen - mlen); 299 300 /* 301 * If it isn't for a net on any of our interfaces, or it IS for a net 302 * on a different interface than it came in on, (and it is not looped 303 * back) then consider if we should forward it. As we are not really 304 * a router this is a bit cheeky, but it may be useful some day. 305 */ 306 if ((aa == NULL) || ((to.sat_addr.s_node == ATADDR_BCAST) && 307 (aa->aa_ifp != ifp) && ((ifp->if_flags & IFF_LOOPBACK) == 0))) { 308 /* 309 * If we've explicitly disabled it, don't route anything. 310 */ 311 if (ddp_forward == 0) 312 goto out; 313 314 /* 315 * If the cached forwarding route is still valid, use it. 316 * 317 * XXXRW: Access to the cached route may not be properly 318 * synchronized for parallel input handling. 319 */ 320 if (forwro.ro_rt && 321 (satosat(&forwro.ro_dst)->sat_addr.s_net != 322 to.sat_addr.s_net || 323 satosat(&forwro.ro_dst)->sat_addr.s_node != 324 to.sat_addr.s_node)) { 325 RTFREE(forwro.ro_rt); 326 forwro.ro_rt = NULL; 327 } 328 329 /* 330 * If we don't have a cached one (any more) or it's useless, 331 * then get a new route. 332 * 333 * XXX this could cause a 'route leak'. Check this! 334 */ 335 if (forwro.ro_rt == NULL || forwro.ro_rt->rt_ifp == NULL) { 336 forwro.ro_dst.sa_len = sizeof(struct sockaddr_at); 337 forwro.ro_dst.sa_family = AF_APPLETALK; 338 satosat(&forwro.ro_dst)->sat_addr.s_net = 339 to.sat_addr.s_net; 340 satosat(&forwro.ro_dst)->sat_addr.s_node = 341 to.sat_addr.s_node; 342 rtalloc(&forwro); 343 } 344 345 /* 346 * If it's not going to get there on this hop, and it's 347 * already done too many hops, then throw it away. 348 */ 349 if ((to.sat_addr.s_net != 350 satosat(&forwro.ro_dst)->sat_addr.s_net) && 351 (ddpe.deh_hops == DDP_MAXHOPS)) 352 goto out; 353 354 /* 355 * A ddp router might use the same interface to forward the 356 * packet, which this would not effect. Don't allow packets 357 * to cross from one interface to another however. 358 */ 359 if (ddp_firewall && ((forwro.ro_rt == NULL) || 360 (forwro.ro_rt->rt_ifp != ifp))) 361 goto out; 362 363 /* 364 * Adjust the header. If it was a short header then it would 365 * have not gotten here, so we can assume there is room to 366 * drop the header in. 367 * 368 * XXX what about promiscuous mode, etc... 369 */ 370 ddpe.deh_hops++; 371 ddpe.deh_bytes = htonl(ddpe.deh_bytes); 372 /* XXX deh? */ 373 bcopy((caddr_t)&ddpe, (caddr_t)deh, sizeof(u_short)); 374 if (ddp_route(m, &forwro)) 375 ddpstat.ddps_cantforward++; 376 else 377 ddpstat.ddps_forward++; 378 if (aa != NULL) 379 ifa_free(&aa->aa_ifa); 380 return; 381 } 382 383 /* 384 * It was for us, and we have an ifaddr to use with it. 385 */ 386 from.sat_len = sizeof(struct sockaddr_at); 387 from.sat_family = AF_APPLETALK; 388 389 /* 390 * We are no longer interested in the link layer so cut it off. 391 */ 392 if (elh == NULL) { 393 if (ddp_cksum && cksum && cksum != 394 at_cksum(m, sizeof(int))) { 395 ddpstat.ddps_badsum++; 396 goto out; 397 } 398 m_adj(m, sizeof(struct ddpehdr)); 399 } else 400 m_adj(m, sizeof(struct ddpshdr)); 401 402 /* 403 * Search for ddp protocol control blocks that match these addresses. 404 */ 405 DDP_LIST_SLOCK(); 406 if ((ddp = ddp_search(&from, &to, aa)) == NULL) 407 goto out_unlock; 408 409#ifdef MAC 410 if (mac_socket_check_deliver(ddp->ddp_socket, m) != 0) 411 goto out_unlock; 412#endif 413 414 /* 415 * If we found one, deliver the packet to the socket 416 */ 417 SOCKBUF_LOCK(&ddp->ddp_socket->so_rcv); 418 if (sbappendaddr_locked(&ddp->ddp_socket->so_rcv, 419 (struct sockaddr *)&from, m, NULL) == 0) { 420 SOCKBUF_UNLOCK(&ddp->ddp_socket->so_rcv); 421 /* 422 * If the socket is full (or similar error) dump the packet. 423 */ 424 ddpstat.ddps_nosockspace++; 425 goto out_unlock; 426 } 427 428 /* 429 * And wake up whatever might be waiting for it 430 */ 431 sorwakeup_locked(ddp->ddp_socket); 432 m = NULL; 433out_unlock: 434 DDP_LIST_SUNLOCK(); 435out: 436 if (aa != NULL) 437 ifa_free(&aa->aa_ifa); 438 if (m != NULL) 439 m_freem(m); 440} 441