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 this notice is preserved and that due credit is given 7 * to the University of California at Berkeley. The name of the University 8 * may not be used to endorse or promote products derived from this 9 * software without specific prior written permission. This software 10 * is provided ``as is'' without express or implied warranty. 11 * 12 * @(#)ns_input.c 7.2 (Berkeley) 01/20/88 13 */ 14 15 #include "param.h" 16 #include "systm.h" 17 #include "mbuf.h" 18 #include "domain.h" 19 #include "protosw.h" 20 #include "socket.h" 21 #include "socketvar.h" 22 #include "errno.h" 23 #include "time.h" 24 #include "kernel.h" 25 26 #include "../net/if.h" 27 #include "../net/route.h" 28 #include "../net/raw_cb.h" 29 30 #include "ns.h" 31 #include "ns_if.h" 32 #include "ns_pcb.h" 33 #include "idp.h" 34 #include "idp_var.h" 35 #include "ns_error.h" 36 37 /* 38 * NS initialization. 39 */ 40 union ns_host ns_thishost; 41 union ns_host ns_zerohost; 42 union ns_host ns_broadhost; 43 union ns_net ns_zeronet; 44 union ns_net ns_broadnet; 45 46 static u_short allones[] = {-1, -1, -1}; 47 48 struct nspcb nspcb; 49 struct nspcb nsrawpcb; 50 51 struct ifqueue nsintrq; 52 int nsqmaxlen = IFQ_MAXLEN; 53 54 int idpcksum = 1; 55 long ns_pexseq; 56 57 ns_init() 58 { 59 extern struct timeval time; 60 61 ns_broadhost = * (union ns_host *) allones; 62 ns_broadnet = * (union ns_net *) allones; 63 nspcb.nsp_next = nspcb.nsp_prev = &nspcb; 64 nsrawpcb.nsp_next = nsrawpcb.nsp_prev = &nsrawpcb; 65 nsintrq.ifq_maxlen = nsqmaxlen; 66 ns_pexseq = time.tv_usec; 67 } 68 69 /* 70 * Idp input routine. Pass to next level. 71 */ 72 int nsintr_getpck = 0; 73 int nsintr_swtch = 0; 74 nsintr() 75 { 76 register struct idp *idp; 77 register struct mbuf *m; 78 register struct nspcb *nsp; 79 struct ifnet *ifp; 80 struct mbuf *m0; 81 register int i; 82 int len, s, error; 83 char oddpacketp; 84 85 next: 86 /* 87 * Get next datagram off input queue and get IDP header 88 * in first mbuf. 89 */ 90 s = splimp(); 91 IF_DEQUEUEIF(&nsintrq, m, ifp); 92 splx(s); 93 nsintr_getpck++; 94 if (m == 0) 95 return; 96 if ((m->m_off > MMAXOFF || m->m_len < sizeof (struct idp)) && 97 (m = m_pullup(m, sizeof (struct idp))) == 0) { 98 idpstat.idps_toosmall++; 99 goto next; 100 } 101 102 /* 103 * Give any raw listeners a crack at the packet 104 */ 105 for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) { 106 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL); 107 if (m1) idp_input(m1, nsp, ifp); 108 } 109 110 idp = mtod(m, struct idp *); 111 len = ntohs(idp->idp_len); 112 if (oddpacketp = len & 1) { 113 len++; /* If this packet is of odd length, 114 preserve garbage byte for checksum */ 115 } 116 117 /* 118 * Check that the amount of data in the buffers 119 * is as at least much as the IDP header would have us expect. 120 * Trim mbufs if longer than we expect. 121 * Drop packet if shorter than we expect. 122 */ 123 i = -len; 124 m0 = m; 125 for (;;) { 126 i += m->m_len; 127 if (m->m_next == 0) 128 break; 129 m = m->m_next; 130 } 131 if (i != 0) { 132 if (i < 0) { 133 idpstat.idps_tooshort++; 134 m = m0; 135 goto bad; 136 } 137 if (i <= m->m_len) 138 m->m_len -= i; 139 else 140 m_adj(m0, -i); 141 } 142 m = m0; 143 if (idpcksum && ((i = idp->idp_sum)!=0xffff)) { 144 idp->idp_sum = 0; 145 if (i != (idp->idp_sum = ns_cksum(m,len))) { 146 idpstat.idps_badsum++; 147 idp->idp_sum = i; 148 if (ns_hosteqnh(ns_thishost, idp->idp_dna.x_host)) 149 error = NS_ERR_BADSUM; 150 else 151 error = NS_ERR_BADSUM_T; 152 ns_error(m, error, 0); 153 goto next; 154 } 155 } 156 /* 157 * Is this a directed broadcast? 158 */ 159 if (ns_hosteqnh(ns_broadhost,idp->idp_dna.x_host)) { 160 if ((!ns_neteq(idp->idp_dna, idp->idp_sna)) && 161 (!ns_neteqnn(idp->idp_dna.x_net, ns_broadnet)) && 162 (!ns_neteqnn(idp->idp_sna.x_net, ns_zeronet)) && 163 (!ns_neteqnn(idp->idp_dna.x_net, ns_zeronet)) ) { 164 /* 165 * Look to see if I need to eat this packet. 166 * Algorithm is to forward all young packets 167 * and prematurely age any packets which will 168 * by physically broadcasted. 169 * Any very old packets eaten without forwarding 170 * would die anyway. 171 * 172 * Suggestion of Bill Nesheim, Cornell U. 173 */ 174 if (idp->idp_tc < NS_MAXHOPS) { 175 idp_forward(idp); 176 goto next; 177 } 178 } 179 /* 180 * Is this our packet? If not, forward. 181 */ 182 } else if (!ns_hosteqnh(ns_thishost,idp->idp_dna.x_host)) { 183 idp_forward(idp); 184 goto next; 185 } 186 /* 187 * Locate pcb for datagram. 188 */ 189 nsp = ns_pcblookup(&idp->idp_sna, idp->idp_dna.x_port, NS_WILDCARD); 190 /* 191 * Switch out to protocol's input routine. 192 */ 193 nsintr_swtch++; 194 if (nsp) { 195 if (oddpacketp) { 196 m_adj(m0, -1); 197 } 198 if ((nsp->nsp_flags & NSP_ALL_PACKETS)==0) 199 switch (idp->idp_pt) { 200 201 case NSPROTO_SPP: 202 spp_input(m, nsp, ifp); 203 goto next; 204 205 case NSPROTO_ERROR: 206 ns_err_input(m); 207 goto next; 208 } 209 idp_input(m, nsp, ifp); 210 } else { 211 ns_error(m, NS_ERR_NOSOCK, 0); 212 } 213 goto next; 214 215 bad: 216 m_freem(m); 217 goto next; 218 } 219 220 u_char nsctlerrmap[PRC_NCMDS] = { 221 ECONNABORTED, ECONNABORTED, 0, 0, 222 0, 0, EHOSTDOWN, EHOSTUNREACH, 223 ENETUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, 224 EMSGSIZE, 0, 0, 0, 225 0, 0, 0, 0 226 }; 227 228 idp_donosocks = 1; 229 230 idp_ctlinput(cmd, arg) 231 int cmd; 232 caddr_t arg; 233 { 234 struct ns_addr *ns; 235 struct nspcb *nsp; 236 struct ns_errp *errp; 237 int idp_abort(); 238 extern struct nspcb *idp_drop(); 239 int type; 240 241 if (cmd < 0 || cmd > PRC_NCMDS) 242 return; 243 if (nsctlerrmap[cmd] == 0) 244 return; /* XXX */ 245 type = NS_ERR_UNREACH_HOST; 246 switch (cmd) { 247 struct sockaddr_ns *sns; 248 249 case PRC_IFDOWN: 250 case PRC_HOSTDEAD: 251 case PRC_HOSTUNREACH: 252 sns = (struct sockaddr_ns *)arg; 253 if (sns->sns_family != AF_INET) 254 return; 255 ns = &sns->sns_addr; 256 break; 257 258 default: 259 errp = (struct ns_errp *)arg; 260 ns = &errp->ns_err_idp.idp_dna; 261 type = errp->ns_err_num; 262 type = ntohs((u_short)type); 263 } 264 switch (type) { 265 266 case NS_ERR_UNREACH_HOST: 267 ns_pcbnotify(ns, (int)nsctlerrmap[cmd], idp_abort, (long)0); 268 break; 269 270 case NS_ERR_NOSOCK: 271 nsp = ns_pcblookup(ns, errp->ns_err_idp.idp_sna.x_port, 272 NS_WILDCARD); 273 if(nsp && idp_donosocks && ! ns_nullhost(nsp->nsp_faddr)) 274 (void) idp_drop(nsp, (int)nsctlerrmap[cmd]); 275 } 276 } 277 278 int idpprintfs = 0; 279 int idpforwarding = 1; 280 /* 281 * Forward a packet. If some error occurs return the sender 282 * an error packet. Note we can't always generate a meaningful 283 * error message because the NS errors don't have a large enough repetoire 284 * of codes and types. 285 */ 286 struct route idp_droute; 287 struct route idp_sroute; 288 289 idp_forward(idp) 290 register struct idp *idp; 291 { 292 register int error, type, code; 293 struct mbuf *mcopy = NULL; 294 int agedelta = 1; 295 int flags = NS_FORWARDING; 296 int ok_there = 0; 297 int ok_back = 0; 298 299 if (idpprintfs) { 300 printf("forward: src "); 301 ns_printhost(&idp->idp_sna); 302 printf(", dst "); 303 ns_printhost(&idp->idp_dna); 304 printf("hop count %d\n", idp->idp_tc); 305 } 306 if (idpforwarding == 0) { 307 /* can't tell difference between net and host */ 308 type = NS_ERR_UNREACH_HOST, code = 0; 309 goto senderror; 310 } 311 idp->idp_tc++; 312 if (idp->idp_tc > NS_MAXHOPS) { 313 type = NS_ERR_TOO_OLD, code = 0; 314 goto senderror; 315 } 316 /* 317 * Save at most 42 bytes of the packet in case 318 * we need to generate an NS error message to the src. 319 */ 320 mcopy = m_copy(dtom(idp), 0, imin((int)ntohs(idp->idp_len), 42)); 321 322 if ((ok_there = idp_do_route(&idp->idp_dna,&idp_droute))==0) { 323 type = NS_ERR_UNREACH_HOST, code = 0; 324 goto senderror; 325 } 326 /* 327 * Here we think about forwarding broadcast packets, 328 * so we try to insure that it doesn't go back out 329 * on the interface it came in on. Also, if we 330 * are going to physically broadcast this, let us 331 * age the packet so we can eat it safely the second time around. 332 */ 333 if (idp->idp_dna.x_host.c_host[0] & 0x1) { 334 struct ns_ifaddr *ia = ns_iaonnetof(&idp->idp_dna); 335 struct ifnet *ifp; 336 if (ia) { 337 /* I'm gonna hafta eat this packet */ 338 agedelta += NS_MAXHOPS - idp->idp_tc; 339 idp->idp_tc = NS_MAXHOPS; 340 } 341 if ((ok_back = idp_do_route(&idp->idp_sna,&idp_sroute))==0) { 342 /* error = ENETUNREACH; He'll never get it! */ 343 m_freem(dtom(idp)); 344 goto cleanup; 345 } 346 if (idp_droute.ro_rt && 347 (ifp=idp_droute.ro_rt->rt_ifp) && 348 idp_sroute.ro_rt && 349 (ifp!=idp_sroute.ro_rt->rt_ifp)) { 350 flags |= NS_ALLOWBROADCAST; 351 } else { 352 type = NS_ERR_UNREACH_HOST, code = 0; 353 goto senderror; 354 } 355 } 356 /* need to adjust checksum */ 357 if (idp->idp_sum!=0xffff) { 358 union bytes { 359 u_char c[4]; 360 u_short s[2]; 361 long l; 362 } x; 363 register int shift; 364 x.l = 0; x.c[0] = agedelta; 365 shift = (((((int)ntohs(idp->idp_len))+1)>>1)-2) & 0xf; 366 x.l = idp->idp_sum + (x.l << shift); 367 x.l = x.s[0] + x.s[1]; 368 x.l = x.s[0] + x.s[1]; 369 if (x.l==0xffff) idp->idp_sum = 0; else idp->idp_sum = x.l; 370 } 371 if ((error = ns_output(dtom(idp), &idp_droute, flags)) && 372 (mcopy!=NULL)) { 373 idp = mtod(mcopy, struct idp *); 374 type = NS_ERR_UNSPEC_T, code = 0; 375 switch (error) { 376 377 case ENETUNREACH: 378 case EHOSTDOWN: 379 case EHOSTUNREACH: 380 case ENETDOWN: 381 case EPERM: 382 type = NS_ERR_UNREACH_HOST; 383 break; 384 385 case EMSGSIZE: 386 type = NS_ERR_TOO_BIG; 387 code = 576; /* too hard to figure out mtu here */ 388 break; 389 390 case ENOBUFS: 391 type = NS_ERR_UNSPEC_T; 392 break; 393 } 394 mcopy = NULL; 395 senderror: 396 ns_error(dtom(idp), type, code); 397 } 398 cleanup: 399 if (ok_there) 400 idp_undo_route(&idp_droute); 401 if (ok_back) 402 idp_undo_route(&idp_sroute); 403 if (mcopy != NULL) 404 m_freem(mcopy); 405 } 406 407 idp_do_route(src, ro) 408 struct ns_addr *src; 409 struct route *ro; 410 { 411 412 struct sockaddr_ns *dst; 413 414 bzero((caddr_t)ro, sizeof (*ro)); 415 dst = (struct sockaddr_ns *)&ro->ro_dst; 416 417 dst->sns_family = AF_NS; 418 dst->sns_addr = *src; 419 dst->sns_addr.x_port = 0; 420 rtalloc(ro); 421 if (ro->ro_rt == 0 || ro->ro_rt->rt_ifp == 0) { 422 return (0); 423 } 424 ro->ro_rt->rt_use++; 425 return (1); 426 } 427 428 idp_undo_route(ro) 429 register struct route *ro; 430 { 431 if (ro->ro_rt) {RTFREE(ro->ro_rt);} 432 } 433 static union ns_net 434 ns_zeronet; 435 436 ns_watch_output(m, ifp) 437 struct mbuf *m; 438 struct ifnet *ifp; 439 { 440 register struct nspcb *nsp; 441 register struct ifaddr *ia; 442 /* 443 * Give any raw listeners a crack at the packet 444 */ 445 for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) { 446 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL); 447 if (m0) { 448 struct mbuf *m1 = m_get(M_DONTWAIT, MT_DATA); 449 450 if(m1 == NULL) 451 m_freem(m0); 452 else { 453 register struct idp *idp; 454 455 m1->m_off = MMINOFF; 456 m1->m_len = sizeof (*idp); 457 m1->m_next = m0; 458 idp = mtod(m1, struct idp *); 459 idp->idp_sna.x_net = ns_zeronet; 460 idp->idp_sna.x_host = ns_thishost; 461 if (ifp && (ifp->if_flags & IFF_POINTOPOINT)) 462 for(ia = ifp->if_addrlist; ia; 463 ia = ia->ifa_next) { 464 if (ia->ifa_addr.sa_family==AF_NS) { 465 idp->idp_sna = 466 satons_addr(ia->ifa_dstaddr); 467 break; 468 } 469 } 470 idp->idp_len = 0xffff; 471 idp_input(m1, nsp, ifp); 472 } 473 } 474 } 475 } 476