1 /* 2 * Copyright (c) 1984, 1985, 1986, 1987 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 * 17 * @(#)ns_input.c 7.6 (Berkeley) 04/22/89 18 */ 19 20 #include "param.h" 21 #include "systm.h" 22 #include "malloc.h" 23 #include "mbuf.h" 24 #include "domain.h" 25 #include "protosw.h" 26 #include "socket.h" 27 #include "socketvar.h" 28 #include "errno.h" 29 #include "time.h" 30 #include "kernel.h" 31 32 #include "../net/if.h" 33 #include "../net/route.h" 34 #include "../net/raw_cb.h" 35 36 #include "ns.h" 37 #include "ns_if.h" 38 #include "ns_pcb.h" 39 #include "idp.h" 40 #include "idp_var.h" 41 #include "ns_error.h" 42 43 /* 44 * NS initialization. 45 */ 46 union ns_host ns_thishost; 47 union ns_host ns_zerohost; 48 union ns_host ns_broadhost; 49 union ns_net ns_zeronet; 50 union ns_net ns_broadnet; 51 struct sockaddr_ns ns_netmask, ns_hostmask; 52 53 static u_short allones[] = {-1, -1, -1}; 54 55 struct nspcb nspcb; 56 struct nspcb nsrawpcb; 57 58 struct ifqueue nsintrq; 59 int nsqmaxlen = IFQ_MAXLEN; 60 61 int idpcksum = 1; 62 long ns_pexseq; 63 64 ns_init() 65 { 66 extern struct timeval time; 67 68 ns_broadhost = * (union ns_host *) allones; 69 ns_broadnet = * (union ns_net *) allones; 70 nspcb.nsp_next = nspcb.nsp_prev = &nspcb; 71 nsrawpcb.nsp_next = nsrawpcb.nsp_prev = &nsrawpcb; 72 nsintrq.ifq_maxlen = nsqmaxlen; 73 ns_pexseq = time.tv_usec; 74 ns_netmask.sns_len = 6; 75 ns_netmask.sns_addr.x_net = ns_broadnet; 76 ns_hostmask.sns_len = 12; 77 ns_hostmask.sns_addr.x_net = ns_broadnet; 78 ns_hostmask.sns_addr.x_host = ns_broadhost; 79 } 80 81 /* 82 * Idp input routine. Pass to next level. 83 */ 84 int nsintr_getpck = 0; 85 int nsintr_swtch = 0; 86 nsintr() 87 { 88 register struct idp *idp; 89 register struct mbuf *m; 90 register struct nspcb *nsp; 91 register int i; 92 int len, s, error; 93 char oddpacketp; 94 95 next: 96 /* 97 * Get next datagram off input queue and get IDP header 98 * in first mbuf. 99 */ 100 s = splimp(); 101 IF_DEQUEUE(&nsintrq, m); 102 splx(s); 103 nsintr_getpck++; 104 if (m == 0) 105 return; 106 if ((m->m_flags & M_EXT || m->m_len < sizeof (struct idp)) && 107 (m = m_pullup(m, sizeof (struct idp))) == 0) { 108 idpstat.idps_toosmall++; 109 goto next; 110 } 111 112 /* 113 * Give any raw listeners a crack at the packet 114 */ 115 for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) { 116 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL); 117 if (m1) idp_input(m1, nsp); 118 } 119 120 idp = mtod(m, struct idp *); 121 len = ntohs(idp->idp_len); 122 if (oddpacketp = len & 1) { 123 len++; /* If this packet is of odd length, 124 preserve garbage byte for checksum */ 125 } 126 127 /* 128 * Check that the amount of data in the buffers 129 * is as at least much as the IDP header would have us expect. 130 * Trim mbufs if longer than we expect. 131 * Drop packet if shorter than we expect. 132 */ 133 if (m->m_pkthdr.len < len) { 134 idpstat.idps_tooshort++; 135 goto bad; 136 } 137 if (m->m_pkthdr.len > len) { 138 if (m->m_len == m->m_pkthdr.len) { 139 m->m_len = len; 140 m->m_pkthdr.len = len; 141 } else 142 m_adj(m, len - m->m_pkthdr.len); 143 } 144 if (idpcksum && ((i = idp->idp_sum)!=0xffff)) { 145 idp->idp_sum = 0; 146 if (i != (idp->idp_sum = ns_cksum(m, len))) { 147 idpstat.idps_badsum++; 148 idp->idp_sum = i; 149 if (ns_hosteqnh(ns_thishost, idp->idp_dna.x_host)) 150 error = NS_ERR_BADSUM; 151 else 152 error = NS_ERR_BADSUM_T; 153 ns_error(m, error, 0); 154 goto next; 155 } 156 } 157 /* 158 * Is this a directed broadcast? 159 */ 160 if (ns_hosteqnh(ns_broadhost,idp->idp_dna.x_host)) { 161 if ((!ns_neteq(idp->idp_dna, idp->idp_sna)) && 162 (!ns_neteqnn(idp->idp_dna.x_net, ns_broadnet)) && 163 (!ns_neteqnn(idp->idp_sna.x_net, ns_zeronet)) && 164 (!ns_neteqnn(idp->idp_dna.x_net, ns_zeronet)) ) { 165 /* 166 * Look to see if I need to eat this packet. 167 * Algorithm is to forward all young packets 168 * and prematurely age any packets which will 169 * by physically broadcasted. 170 * Any very old packets eaten without forwarding 171 * would die anyway. 172 * 173 * Suggestion of Bill Nesheim, Cornell U. 174 */ 175 if (idp->idp_tc < NS_MAXHOPS) { 176 idp_forward(m); 177 goto next; 178 } 179 } 180 /* 181 * Is this our packet? If not, forward. 182 */ 183 } else if (!ns_hosteqnh(ns_thishost,idp->idp_dna.x_host)) { 184 idp_forward(m); 185 goto next; 186 } 187 /* 188 * Locate pcb for datagram. 189 */ 190 nsp = ns_pcblookup(&idp->idp_sna, idp->idp_dna.x_port, NS_WILDCARD); 191 /* 192 * Switch out to protocol's input routine. 193 */ 194 nsintr_swtch++; 195 if (nsp) { 196 if (oddpacketp) { 197 m_adj(m, -1); 198 } 199 if ((nsp->nsp_flags & NSP_ALL_PACKETS)==0) 200 switch (idp->idp_pt) { 201 202 case NSPROTO_SPP: 203 spp_input(m, nsp); 204 goto next; 205 206 case NSPROTO_ERROR: 207 ns_err_input(m); 208 goto next; 209 } 210 idp_input(m, nsp); 211 } else { 212 ns_error(m, NS_ERR_NOSOCK, 0); 213 } 214 goto next; 215 216 bad: 217 m_freem(m); 218 goto next; 219 } 220 221 u_char nsctlerrmap[PRC_NCMDS] = { 222 ECONNABORTED, ECONNABORTED, 0, 0, 223 0, 0, EHOSTDOWN, EHOSTUNREACH, 224 ENETUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 225 EMSGSIZE, 0, 0, 0, 226 0, 0, 0, 0 227 }; 228 229 idp_donosocks = 1; 230 231 idp_ctlinput(cmd, arg) 232 int cmd; 233 caddr_t arg; 234 { 235 struct ns_addr *ns; 236 struct nspcb *nsp; 237 struct ns_errp *errp; 238 int idp_abort(); 239 extern struct nspcb *idp_drop(); 240 int type; 241 242 if (cmd < 0 || cmd > PRC_NCMDS) 243 return; 244 if (nsctlerrmap[cmd] == 0) 245 return; /* XXX */ 246 type = NS_ERR_UNREACH_HOST; 247 switch (cmd) { 248 struct sockaddr_ns *sns; 249 250 case PRC_IFDOWN: 251 case PRC_HOSTDEAD: 252 case PRC_HOSTUNREACH: 253 sns = (struct sockaddr_ns *)arg; 254 if (sns->sns_family != AF_NS) 255 return; 256 ns = &sns->sns_addr; 257 break; 258 259 default: 260 errp = (struct ns_errp *)arg; 261 ns = &errp->ns_err_idp.idp_dna; 262 type = errp->ns_err_num; 263 type = ntohs((u_short)type); 264 } 265 switch (type) { 266 267 case NS_ERR_UNREACH_HOST: 268 ns_pcbnotify(ns, (int)nsctlerrmap[cmd], idp_abort, (long)0); 269 break; 270 271 case NS_ERR_NOSOCK: 272 nsp = ns_pcblookup(ns, errp->ns_err_idp.idp_sna.x_port, 273 NS_WILDCARD); 274 if(nsp && idp_donosocks && ! ns_nullhost(nsp->nsp_faddr)) 275 (void) idp_drop(nsp, (int)nsctlerrmap[cmd]); 276 } 277 } 278 279 int idpprintfs = 0; 280 int idpforwarding = 1; 281 /* 282 * Forward a packet. If some error occurs return the sender 283 * an error packet. Note we can't always generate a meaningful 284 * error message because the NS errors don't have a large enough repetoire 285 * of codes and types. 286 */ 287 struct route idp_droute; 288 struct route idp_sroute; 289 290 idp_forward(m) 291 struct mbuf *m; 292 { 293 register struct idp *idp = mtod(m, struct idp *); 294 register int error, type, code; 295 struct mbuf *mcopy = NULL; 296 int agedelta = 1; 297 int flags = NS_FORWARDING; 298 int ok_there = 0; 299 int ok_back = 0; 300 301 if (idpprintfs) { 302 printf("forward: src "); 303 ns_printhost(&idp->idp_sna); 304 printf(", dst "); 305 ns_printhost(&idp->idp_dna); 306 printf("hop count %d\n", idp->idp_tc); 307 } 308 if (idpforwarding == 0) { 309 /* can't tell difference between net and host */ 310 type = NS_ERR_UNREACH_HOST, code = 0; 311 goto senderror; 312 } 313 idp->idp_tc++; 314 if (idp->idp_tc > NS_MAXHOPS) { 315 type = NS_ERR_TOO_OLD, code = 0; 316 goto senderror; 317 } 318 /* 319 * Save at most 42 bytes of the packet in case 320 * we need to generate an NS error message to the src. 321 */ 322 mcopy = m_copy(m, 0, imin((int)ntohs(idp->idp_len), 42)); 323 324 if ((ok_there = idp_do_route(&idp->idp_dna,&idp_droute))==0) { 325 type = NS_ERR_UNREACH_HOST, code = 0; 326 goto senderror; 327 } 328 /* 329 * Here we think about forwarding broadcast packets, 330 * so we try to insure that it doesn't go back out 331 * on the interface it came in on. Also, if we 332 * are going to physically broadcast this, let us 333 * age the packet so we can eat it safely the second time around. 334 */ 335 if (idp->idp_dna.x_host.c_host[0] & 0x1) { 336 struct ns_ifaddr *ia = ns_iaonnetof(&idp->idp_dna); 337 struct ifnet *ifp; 338 if (ia) { 339 /* I'm gonna hafta eat this packet */ 340 agedelta += NS_MAXHOPS - idp->idp_tc; 341 idp->idp_tc = NS_MAXHOPS; 342 } 343 if ((ok_back = idp_do_route(&idp->idp_sna,&idp_sroute))==0) { 344 /* error = ENETUNREACH; He'll never get it! */ 345 m_freem(m); 346 goto cleanup; 347 } 348 if (idp_droute.ro_rt && 349 (ifp=idp_droute.ro_rt->rt_ifp) && 350 idp_sroute.ro_rt && 351 (ifp!=idp_sroute.ro_rt->rt_ifp)) { 352 flags |= NS_ALLOWBROADCAST; 353 } else { 354 type = NS_ERR_UNREACH_HOST, code = 0; 355 goto senderror; 356 } 357 } 358 /* need to adjust checksum */ 359 if (idp->idp_sum!=0xffff) { 360 union bytes { 361 u_char c[4]; 362 u_short s[2]; 363 long l; 364 } x; 365 register int shift; 366 x.l = 0; x.c[0] = agedelta; 367 shift = (((((int)ntohs(idp->idp_len))+1)>>1)-2) & 0xf; 368 x.l = idp->idp_sum + (x.s[0] << shift); 369 x.l = x.s[0] + x.s[1]; 370 x.l = x.s[0] + x.s[1]; 371 if (x.l==0xffff) idp->idp_sum = 0; else idp->idp_sum = x.l; 372 } 373 if ((error = ns_output(m, &idp_droute, flags)) && 374 (mcopy!=NULL)) { 375 idp = mtod(mcopy, struct idp *); 376 type = NS_ERR_UNSPEC_T, code = 0; 377 switch (error) { 378 379 case ENETUNREACH: 380 case EHOSTDOWN: 381 case EHOSTUNREACH: 382 case ENETDOWN: 383 case EPERM: 384 type = NS_ERR_UNREACH_HOST; 385 break; 386 387 case EMSGSIZE: 388 type = NS_ERR_TOO_BIG; 389 code = 576; /* too hard to figure out mtu here */ 390 break; 391 392 case ENOBUFS: 393 type = NS_ERR_UNSPEC_T; 394 break; 395 } 396 mcopy = NULL; 397 senderror: 398 ns_error(m, type, code); 399 } 400 cleanup: 401 if (ok_there) 402 idp_undo_route(&idp_droute); 403 if (ok_back) 404 idp_undo_route(&idp_sroute); 405 if (mcopy != NULL) 406 m_freem(mcopy); 407 } 408 409 idp_do_route(src, ro) 410 struct ns_addr *src; 411 struct route *ro; 412 { 413 414 struct sockaddr_ns *dst; 415 416 bzero((caddr_t)ro, sizeof (*ro)); 417 dst = (struct sockaddr_ns *)&ro->ro_dst; 418 419 dst->sns_len = sizeof(*dst); 420 dst->sns_family = AF_NS; 421 dst->sns_addr = *src; 422 dst->sns_addr.x_port = 0; 423 rtalloc(ro); 424 if (ro->ro_rt == 0 || ro->ro_rt->rt_ifp == 0) { 425 return (0); 426 } 427 ro->ro_rt->rt_use++; 428 return (1); 429 } 430 431 idp_undo_route(ro) 432 register struct route *ro; 433 { 434 if (ro->ro_rt) {RTFREE(ro->ro_rt);} 435 } 436 static union ns_net 437 ns_zeronet; 438 439 ns_watch_output(m, ifp) 440 struct mbuf *m; 441 struct ifnet *ifp; 442 { 443 register struct nspcb *nsp; 444 register struct ifaddr *ifa; 445 /* 446 * Give any raw listeners a crack at the packet 447 */ 448 for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) { 449 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL); 450 if (m0) { 451 register struct idp *idp; 452 453 M_PREPEND(m0, sizeof (*idp), M_DONTWAIT); 454 if (m0 == NULL) 455 continue; 456 idp = mtod(m0, struct idp *); 457 idp->idp_sna.x_net = ns_zeronet; 458 idp->idp_sna.x_host = ns_thishost; 459 if (ifp && (ifp->if_flags & IFF_POINTOPOINT)) 460 for(ifa = ifp->if_addrlist; ifa; 461 ifa = ifa->ifa_next) { 462 if (ifa->ifa_addr->sa_family==AF_NS) { 463 idp->idp_sna = IA_SNS(ifa)->sns_addr; 464 break; 465 } 466 } 467 idp->idp_len = ntohl(m0->m_pkthdr.len); 468 idp_input(m0, nsp); 469 } 470 } 471 } 472