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 7.4 (Berkeley) 06/29/88 18 */ 19 20 #include "param.h" 21 #include "systm.h" 22 #include "mbuf.h" 23 #include "domain.h" 24 #include "protosw.h" 25 #include "socket.h" 26 #include "socketvar.h" 27 #include "errno.h" 28 #include "time.h" 29 #include "kernel.h" 30 31 #include "../net/if.h" 32 #include "../net/route.h" 33 #include "../net/raw_cb.h" 34 35 #include "ns.h" 36 #include "ns_if.h" 37 #include "ns_pcb.h" 38 #include "idp.h" 39 #include "idp_var.h" 40 #include "ns_error.h" 41 42 /* 43 * NS initialization. 44 */ 45 union ns_host ns_thishost; 46 union ns_host ns_zerohost; 47 union ns_host ns_broadhost; 48 union ns_net ns_zeronet; 49 union ns_net ns_broadnet; 50 51 static u_short allones[] = {-1, -1, -1}; 52 53 struct nspcb nspcb; 54 struct nspcb nsrawpcb; 55 56 struct ifqueue nsintrq; 57 int nsqmaxlen = IFQ_MAXLEN; 58 59 int idpcksum = 1; 60 long ns_pexseq; 61 62 ns_init() 63 { 64 extern struct timeval time; 65 66 ns_broadhost = * (union ns_host *) allones; 67 ns_broadnet = * (union ns_net *) allones; 68 nspcb.nsp_next = nspcb.nsp_prev = &nspcb; 69 nsrawpcb.nsp_next = nsrawpcb.nsp_prev = &nsrawpcb; 70 nsintrq.ifq_maxlen = nsqmaxlen; 71 ns_pexseq = time.tv_usec; 72 } 73 74 /* 75 * Idp input routine. Pass to next level. 76 */ 77 int nsintr_getpck = 0; 78 int nsintr_swtch = 0; 79 nsintr() 80 { 81 register struct idp *idp; 82 register struct mbuf *m; 83 register struct nspcb *nsp; 84 struct ifnet *ifp; 85 struct mbuf *m0; 86 register int i; 87 int len, s, error; 88 char oddpacketp; 89 90 next: 91 /* 92 * Get next datagram off input queue and get IDP header 93 * in first mbuf. 94 */ 95 s = splimp(); 96 IF_DEQUEUEIF(&nsintrq, m, ifp); 97 splx(s); 98 nsintr_getpck++; 99 if (m == 0) 100 return; 101 if ((m->m_off > MMAXOFF || m->m_len < sizeof (struct idp)) && 102 (m = m_pullup(m, sizeof (struct idp))) == 0) { 103 idpstat.idps_toosmall++; 104 goto next; 105 } 106 107 /* 108 * Give any raw listeners a crack at the packet 109 */ 110 for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) { 111 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL); 112 if (m1) idp_input(m1, nsp, ifp); 113 } 114 115 idp = mtod(m, struct idp *); 116 len = ntohs(idp->idp_len); 117 if (oddpacketp = len & 1) { 118 len++; /* If this packet is of odd length, 119 preserve garbage byte for checksum */ 120 } 121 122 /* 123 * Check that the amount of data in the buffers 124 * is as at least much as the IDP header would have us expect. 125 * Trim mbufs if longer than we expect. 126 * Drop packet if shorter than we expect. 127 */ 128 i = -len; 129 m0 = m; 130 for (;;) { 131 i += m->m_len; 132 if (m->m_next == 0) 133 break; 134 m = m->m_next; 135 } 136 if (i != 0) { 137 if (i < 0) { 138 idpstat.idps_tooshort++; 139 m = m0; 140 goto bad; 141 } 142 if (i <= m->m_len) 143 m->m_len -= i; 144 else 145 m_adj(m0, -i); 146 } 147 m = m0; 148 if (idpcksum && ((i = idp->idp_sum)!=0xffff)) { 149 idp->idp_sum = 0; 150 if (i != (idp->idp_sum = ns_cksum(m,len))) { 151 idpstat.idps_badsum++; 152 idp->idp_sum = i; 153 if (ns_hosteqnh(ns_thishost, idp->idp_dna.x_host)) 154 error = NS_ERR_BADSUM; 155 else 156 error = NS_ERR_BADSUM_T; 157 ns_error(m, error, 0); 158 goto next; 159 } 160 } 161 /* 162 * Is this a directed broadcast? 163 */ 164 if (ns_hosteqnh(ns_broadhost,idp->idp_dna.x_host)) { 165 if ((!ns_neteq(idp->idp_dna, idp->idp_sna)) && 166 (!ns_neteqnn(idp->idp_dna.x_net, ns_broadnet)) && 167 (!ns_neteqnn(idp->idp_sna.x_net, ns_zeronet)) && 168 (!ns_neteqnn(idp->idp_dna.x_net, ns_zeronet)) ) { 169 /* 170 * Look to see if I need to eat this packet. 171 * Algorithm is to forward all young packets 172 * and prematurely age any packets which will 173 * by physically broadcasted. 174 * Any very old packets eaten without forwarding 175 * would die anyway. 176 * 177 * Suggestion of Bill Nesheim, Cornell U. 178 */ 179 if (idp->idp_tc < NS_MAXHOPS) { 180 idp_forward(idp); 181 goto next; 182 } 183 } 184 /* 185 * Is this our packet? If not, forward. 186 */ 187 } else if (!ns_hosteqnh(ns_thishost,idp->idp_dna.x_host)) { 188 idp_forward(idp); 189 goto next; 190 } 191 /* 192 * Locate pcb for datagram. 193 */ 194 nsp = ns_pcblookup(&idp->idp_sna, idp->idp_dna.x_port, NS_WILDCARD); 195 /* 196 * Switch out to protocol's input routine. 197 */ 198 nsintr_swtch++; 199 if (nsp) { 200 if (oddpacketp) { 201 m_adj(m0, -1); 202 } 203 if ((nsp->nsp_flags & NSP_ALL_PACKETS)==0) 204 switch (idp->idp_pt) { 205 206 case NSPROTO_SPP: 207 spp_input(m, nsp, ifp); 208 goto next; 209 210 case NSPROTO_ERROR: 211 ns_err_input(m); 212 goto next; 213 } 214 idp_input(m, nsp, ifp); 215 } else { 216 ns_error(m, NS_ERR_NOSOCK, 0); 217 } 218 goto next; 219 220 bad: 221 m_freem(m); 222 goto next; 223 } 224 225 u_char nsctlerrmap[PRC_NCMDS] = { 226 ECONNABORTED, ECONNABORTED, 0, 0, 227 0, 0, EHOSTDOWN, EHOSTUNREACH, 228 ENETUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 229 EMSGSIZE, 0, 0, 0, 230 0, 0, 0, 0 231 }; 232 233 idp_donosocks = 1; 234 235 idp_ctlinput(cmd, arg) 236 int cmd; 237 caddr_t arg; 238 { 239 struct ns_addr *ns; 240 struct nspcb *nsp; 241 struct ns_errp *errp; 242 int idp_abort(); 243 extern struct nspcb *idp_drop(); 244 int type; 245 246 if (cmd < 0 || cmd > PRC_NCMDS) 247 return; 248 if (nsctlerrmap[cmd] == 0) 249 return; /* XXX */ 250 type = NS_ERR_UNREACH_HOST; 251 switch (cmd) { 252 struct sockaddr_ns *sns; 253 254 case PRC_IFDOWN: 255 case PRC_HOSTDEAD: 256 case PRC_HOSTUNREACH: 257 sns = (struct sockaddr_ns *)arg; 258 if (sns->sns_family != AF_INET) 259 return; 260 ns = &sns->sns_addr; 261 break; 262 263 default: 264 errp = (struct ns_errp *)arg; 265 ns = &errp->ns_err_idp.idp_dna; 266 type = errp->ns_err_num; 267 type = ntohs((u_short)type); 268 } 269 switch (type) { 270 271 case NS_ERR_UNREACH_HOST: 272 ns_pcbnotify(ns, (int)nsctlerrmap[cmd], idp_abort, (long)0); 273 break; 274 275 case NS_ERR_NOSOCK: 276 nsp = ns_pcblookup(ns, errp->ns_err_idp.idp_sna.x_port, 277 NS_WILDCARD); 278 if(nsp && idp_donosocks && ! ns_nullhost(nsp->nsp_faddr)) 279 (void) idp_drop(nsp, (int)nsctlerrmap[cmd]); 280 } 281 } 282 283 int idpprintfs = 0; 284 int idpforwarding = 1; 285 /* 286 * Forward a packet. If some error occurs return the sender 287 * an error packet. Note we can't always generate a meaningful 288 * error message because the NS errors don't have a large enough repetoire 289 * of codes and types. 290 */ 291 struct route idp_droute; 292 struct route idp_sroute; 293 294 idp_forward(idp) 295 register struct idp *idp; 296 { 297 register int error, type, code; 298 struct mbuf *mcopy = NULL; 299 int agedelta = 1; 300 int flags = NS_FORWARDING; 301 int ok_there = 0; 302 int ok_back = 0; 303 304 if (idpprintfs) { 305 printf("forward: src "); 306 ns_printhost(&idp->idp_sna); 307 printf(", dst "); 308 ns_printhost(&idp->idp_dna); 309 printf("hop count %d\n", idp->idp_tc); 310 } 311 if (idpforwarding == 0) { 312 /* can't tell difference between net and host */ 313 type = NS_ERR_UNREACH_HOST, code = 0; 314 goto senderror; 315 } 316 idp->idp_tc++; 317 if (idp->idp_tc > NS_MAXHOPS) { 318 type = NS_ERR_TOO_OLD, code = 0; 319 goto senderror; 320 } 321 /* 322 * Save at most 42 bytes of the packet in case 323 * we need to generate an NS error message to the src. 324 */ 325 mcopy = m_copy(dtom(idp), 0, imin((int)ntohs(idp->idp_len), 42)); 326 327 if ((ok_there = idp_do_route(&idp->idp_dna,&idp_droute))==0) { 328 type = NS_ERR_UNREACH_HOST, code = 0; 329 goto senderror; 330 } 331 /* 332 * Here we think about forwarding broadcast packets, 333 * so we try to insure that it doesn't go back out 334 * on the interface it came in on. Also, if we 335 * are going to physically broadcast this, let us 336 * age the packet so we can eat it safely the second time around. 337 */ 338 if (idp->idp_dna.x_host.c_host[0] & 0x1) { 339 struct ns_ifaddr *ia = ns_iaonnetof(&idp->idp_dna); 340 struct ifnet *ifp; 341 if (ia) { 342 /* I'm gonna hafta eat this packet */ 343 agedelta += NS_MAXHOPS - idp->idp_tc; 344 idp->idp_tc = NS_MAXHOPS; 345 } 346 if ((ok_back = idp_do_route(&idp->idp_sna,&idp_sroute))==0) { 347 /* error = ENETUNREACH; He'll never get it! */ 348 m_freem(dtom(idp)); 349 goto cleanup; 350 } 351 if (idp_droute.ro_rt && 352 (ifp=idp_droute.ro_rt->rt_ifp) && 353 idp_sroute.ro_rt && 354 (ifp!=idp_sroute.ro_rt->rt_ifp)) { 355 flags |= NS_ALLOWBROADCAST; 356 } else { 357 type = NS_ERR_UNREACH_HOST, code = 0; 358 goto senderror; 359 } 360 } 361 /* need to adjust checksum */ 362 if (idp->idp_sum!=0xffff) { 363 union bytes { 364 u_char c[4]; 365 u_short s[2]; 366 long l; 367 } x; 368 register int shift; 369 x.l = 0; x.c[0] = agedelta; 370 shift = (((((int)ntohs(idp->idp_len))+1)>>1)-2) & 0xf; 371 x.l = idp->idp_sum + (x.s[0] << shift); 372 x.l = x.s[0] + x.s[1]; 373 x.l = x.s[0] + x.s[1]; 374 if (x.l==0xffff) idp->idp_sum = 0; else idp->idp_sum = x.l; 375 } 376 if ((error = ns_output(dtom(idp), &idp_droute, flags)) && 377 (mcopy!=NULL)) { 378 idp = mtod(mcopy, struct idp *); 379 type = NS_ERR_UNSPEC_T, code = 0; 380 switch (error) { 381 382 case ENETUNREACH: 383 case EHOSTDOWN: 384 case EHOSTUNREACH: 385 case ENETDOWN: 386 case EPERM: 387 type = NS_ERR_UNREACH_HOST; 388 break; 389 390 case EMSGSIZE: 391 type = NS_ERR_TOO_BIG; 392 code = 576; /* too hard to figure out mtu here */ 393 break; 394 395 case ENOBUFS: 396 type = NS_ERR_UNSPEC_T; 397 break; 398 } 399 mcopy = NULL; 400 senderror: 401 ns_error(dtom(idp), type, code); 402 } 403 cleanup: 404 if (ok_there) 405 idp_undo_route(&idp_droute); 406 if (ok_back) 407 idp_undo_route(&idp_sroute); 408 if (mcopy != NULL) 409 m_freem(mcopy); 410 } 411 412 idp_do_route(src, ro) 413 struct ns_addr *src; 414 struct route *ro; 415 { 416 417 struct sockaddr_ns *dst; 418 419 bzero((caddr_t)ro, sizeof (*ro)); 420 dst = (struct sockaddr_ns *)&ro->ro_dst; 421 422 dst->sns_family = AF_NS; 423 dst->sns_addr = *src; 424 dst->sns_addr.x_port = 0; 425 rtalloc(ro); 426 if (ro->ro_rt == 0 || ro->ro_rt->rt_ifp == 0) { 427 return (0); 428 } 429 ro->ro_rt->rt_use++; 430 return (1); 431 } 432 433 idp_undo_route(ro) 434 register struct route *ro; 435 { 436 if (ro->ro_rt) {RTFREE(ro->ro_rt);} 437 } 438 static union ns_net 439 ns_zeronet; 440 441 ns_watch_output(m, ifp) 442 struct mbuf *m; 443 struct ifnet *ifp; 444 { 445 register struct nspcb *nsp; 446 register struct ifaddr *ia; 447 /* 448 * Give any raw listeners a crack at the packet 449 */ 450 for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) { 451 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL); 452 if (m0) { 453 struct mbuf *m1 = m_get(M_DONTWAIT, MT_DATA); 454 455 if(m1 == NULL) 456 m_freem(m0); 457 else { 458 register struct idp *idp; 459 460 m1->m_off = MMINOFF; 461 m1->m_len = sizeof (*idp); 462 m1->m_next = m0; 463 idp = mtod(m1, struct idp *); 464 idp->idp_sna.x_net = ns_zeronet; 465 idp->idp_sna.x_host = ns_thishost; 466 if (ifp && (ifp->if_flags & IFF_POINTOPOINT)) 467 for(ia = ifp->if_addrlist; ia; 468 ia = ia->ifa_next) { 469 if (ia->ifa_addr.sa_family==AF_NS) { 470 idp->idp_sna = 471 satons_addr(ia->ifa_dstaddr); 472 break; 473 } 474 } 475 idp->idp_len = 0xffff; 476 idp_input(m1, nsp, ifp); 477 } 478 } 479 } 480 } 481