| 1 | /* |
| 2 | * Copyright (c) 1982, 1986, 1988 Regents of the University of California. |
| 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 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by the University of |
| 16 | * California, Berkeley and its contributors. |
| 17 | * 4. Neither the name of the University nor the names of its contributors |
| 18 | * may be used to endorse or promote products derived from this software |
| 19 | * without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | * |
| 33 | * from: @(#)ip_input.c 7.19 (Berkeley) 5/25/91 |
| 34 | * $Id: ip_input.c,v 1.2 1993/10/16 18:26:14 rgrimes Exp $ |
| 35 | */ |
| 36 | |
| 37 | #include "param.h" |
| 38 | #include "systm.h" |
| 39 | #include "malloc.h" |
| 40 | #include "mbuf.h" |
| 41 | #include "domain.h" |
| 42 | #include "protosw.h" |
| 43 | #include "socket.h" |
| 44 | #include "errno.h" |
| 45 | #include "time.h" |
| 46 | #include "kernel.h" |
| 47 | |
| 48 | #include "../net/if.h" |
| 49 | #include "../net/route.h" |
| 50 | |
| 51 | #include "in.h" |
| 52 | #include "in_systm.h" |
| 53 | #include "ip.h" |
| 54 | #include "in_pcb.h" |
| 55 | #include "in_var.h" |
| 56 | #include "ip_var.h" |
| 57 | #include "ip_icmp.h" |
| 58 | |
| 59 | #ifndef IPFORWARDING |
| 60 | #ifdef GATEWAY |
| 61 | #define IPFORWARDING 1 /* forward IP packets not for us */ |
| 62 | #else /* GATEWAY */ |
| 63 | #define IPFORWARDING 0 /* don't forward IP packets not for us */ |
| 64 | #endif /* GATEWAY */ |
| 65 | #endif /* IPFORWARDING */ |
| 66 | #ifndef IPSENDREDIRECTS |
| 67 | #define IPSENDREDIRECTS 1 |
| 68 | #endif |
| 69 | int ipforwarding = IPFORWARDING; |
| 70 | int ipsendredirects = IPSENDREDIRECTS; |
| 71 | #ifdef DIAGNOSTIC |
| 72 | int ipprintfs = 0; |
| 73 | #endif |
| 74 | |
| 75 | extern struct domain inetdomain; |
| 76 | extern struct protosw inetsw[]; |
| 77 | u_char ip_protox[IPPROTO_MAX]; |
| 78 | int ipqmaxlen = IFQ_MAXLEN; |
| 79 | struct in_ifaddr *in_ifaddr; /* first inet address */ |
| 80 | struct ipstat ipstat; |
| 81 | struct ipq ipq; |
| 82 | u_short ip_id; |
| 83 | |
| 84 | /* |
| 85 | * We need to save the IP options in case a protocol wants to respond |
| 86 | * to an incoming packet over the same route if the packet got here |
| 87 | * using IP source routing. This allows connection establishment and |
| 88 | * maintenance when the remote end is on a network that is not known |
| 89 | * to us. |
| 90 | */ |
| 91 | int ip_nhops = 0; |
| 92 | static struct ip_srcrt { |
| 93 | struct in_addr dst; /* final destination */ |
| 94 | char nop; /* one NOP to align */ |
| 95 | char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ |
| 96 | struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; |
| 97 | } ip_srcrt; |
| 98 | |
| 99 | #ifdef GATEWAY |
| 100 | extern int if_index; |
| 101 | u_long *ip_ifmatrix; |
| 102 | #endif |
| 103 | |
| 104 | /* |
| 105 | * IP initialization: fill in IP protocol switch table. |
| 106 | * All protocols not implemented in kernel go to raw IP protocol handler. |
| 107 | */ |
| 108 | ip_init() |
| 109 | { |
| 110 | register struct protosw *pr; |
| 111 | register int i; |
| 112 | |
| 113 | pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); |
| 114 | if (pr == 0) |
| 115 | panic("ip_init"); |
| 116 | for (i = 0; i < IPPROTO_MAX; i++) |
| 117 | ip_protox[i] = pr - inetsw; |
| 118 | for (pr = inetdomain.dom_protosw; |
| 119 | pr < inetdomain.dom_protoswNPROTOSW; pr++) |
| 120 | if (pr->pr_domain->dom_family == PF_INET && |
| 121 | pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) |
| 122 | ip_protox[pr->pr_protocol] = pr - inetsw; |
| 123 | ipq.next = ipq.prev = &ipq; |
| 124 | ip_id = time.tv_sec & 0xffff; |
| 125 | ipintrq.ifq_maxlen = ipqmaxlen; |
| 126 | #ifdef GATEWAY |
| 127 | i = (if_index + 1) * (if_index + 1) * sizeof (u_long); |
| 128 | if ((ip_ifmatrix = (u_long *) malloc(i, M_RTABLE, M_WAITOK)) == 0) |
| 129 | panic("no memory for ip_ifmatrix"); |
| 130 | #endif |
| 131 | } |
| 132 | |
| 133 | struct ip *ip_reass(); |
| 134 | struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET }; |
| 135 | struct route ipforward_rt; |
| 136 | |
| 137 | /* |
| 138 | * Ip input routine. Checksum and byte swap header. If fragmented |
| 139 | * try to reassemble. Process options. Pass to next level. |
| 140 | */ |
| 141 | ipintr() |
| 142 | { |
| 143 | register struct ip *ip; |
| 144 | register struct mbuf *m; |
| 145 | register struct ipq *fp; |
| 146 | register struct in_ifaddr *ia; |
| 147 | int hlen, s; |
| 148 | |
| 149 | next: |
| 150 | /* |
| 151 | * Get next datagram off input queue and get IP header |
| 152 | * in first mbuf. |
| 153 | */ |
| 154 | s = splimp(); |
| 155 | IF_DEQUEUE(&ipintrq, m); |
| 156 | splx(s); |
| 157 | if (m == 0) |
| 158 | return; |
| 159 | #ifdef DIAGNOSTIC |
| 160 | if ((m->m_flags & M_PKTHDR) == 0) |
| 161 | panic("ipintr no HDR"); |
| 162 | #endif |
| 163 | /* |
| 164 | * If no IP addresses have been set yet but the interfaces |
| 165 | * are receiving, can't do anything with incoming packets yet. |
| 166 | */ |
| 167 | if (in_ifaddr == NULL) |
| 168 | goto bad; |
| 169 | ipstat.ips_total++; |
| 170 | if (m->m_len < sizeof (struct ip) && |
| 171 | (m = m_pullup(m, sizeof (struct ip))) == 0) { |
| 172 | ipstat.ips_toosmall++; |
| 173 | goto next; |
| 174 | } |
| 175 | ip = mtod(m, struct ip *); |
| 176 | hlen = ip->ip_hl << 2; |
| 177 | if (hlen < sizeof(struct ip)) { /* minimum header length */ |
| 178 | ipstat.ips_badhlen++; |
| 179 | goto bad; |
| 180 | } |
| 181 | if (hlen > m->m_len) { |
| 182 | if ((m = m_pullup(m, hlen)) == 0) { |
| 183 | ipstat.ips_badhlen++; |
| 184 | goto next; |
| 185 | } |
| 186 | ip = mtod(m, struct ip *); |
| 187 | } |
| 188 | if (ip->ip_sum = in_cksum(m, hlen)) { |
| 189 | ipstat.ips_badsum++; |
| 190 | goto bad; |
| 191 | } |
| 192 | |
| 193 | /* |
| 194 | * Convert fields to host representation. |
| 195 | */ |
| 196 | NTOHS(ip->ip_len); |
| 197 | if (ip->ip_len < hlen) { |
| 198 | ipstat.ips_badlen++; |
| 199 | goto bad; |
| 200 | } |
| 201 | NTOHS(ip->ip_id); |
| 202 | NTOHS(ip->ip_off); |
| 203 | |
| 204 | /* |
| 205 | * Check that the amount of data in the buffers |
| 206 | * is as at least much as the IP header would have us expect. |
| 207 | * Trim mbufs if longer than we expect. |
| 208 | * Drop packet if shorter than we expect. |
| 209 | */ |
| 210 | if (m->m_pkthdr.len < ip->ip_len) { |
| 211 | ipstat.ips_tooshort++; |
| 212 | goto bad; |
| 213 | } |
| 214 | if (m->m_pkthdr.len > ip->ip_len) { |
| 215 | if (m->m_len == m->m_pkthdr.len) { |
| 216 | m->m_len = ip->ip_len; |
| 217 | m->m_pkthdr.len = ip->ip_len; |
| 218 | } else |
| 219 | m_adj(m, ip->ip_len - m->m_pkthdr.len); |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * Process options and, if not destined for us, |
| 224 | * ship it on. ip_dooptions returns 1 when an |
| 225 | * error was detected (causing an icmp message |
| 226 | * to be sent and the original packet to be freed). |
| 227 | */ |
| 228 | ip_nhops = 0; /* for source routed packets */ |
| 229 | if (hlen > sizeof (struct ip) && ip_dooptions(m)) |
| 230 | goto next; |
| 231 | |
| 232 | /* |
| 233 | * Check our list of addresses, to see if the packet is for us. |
| 234 | */ |
| 235 | for (ia = in_ifaddr; ia; ia = ia->ia_next) { |
| 236 | #define satosin(sa) ((struct sockaddr_in *)(sa)) |
| 237 | |
| 238 | if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr) |
| 239 | goto ours; |
| 240 | if ( |
| 241 | #ifdef DIRECTED_BROADCAST |
| 242 | ia->ia_ifp == m->m_pkthdr.rcvif && |
| 243 | #endif |
| 244 | (ia->ia_ifp->if_flags & IFF_BROADCAST)) { |
| 245 | u_long t; |
| 246 | |
| 247 | if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == |
| 248 | ip->ip_dst.s_addr) |
| 249 | goto ours; |
| 250 | if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr) |
| 251 | goto ours; |
| 252 | /* |
| 253 | * Look for all-0's host part (old broadcast addr), |
| 254 | * either for subnet or net. |
| 255 | */ |
| 256 | t = ntohl(ip->ip_dst.s_addr); |
| 257 | if (t == ia->ia_subnet) |
| 258 | goto ours; |
| 259 | if (t == ia->ia_net) |
| 260 | goto ours; |
| 261 | } |
| 262 | } |
| 263 | if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST) |
| 264 | goto ours; |
| 265 | if (ip->ip_dst.s_addr == INADDR_ANY) |
| 266 | goto ours; |
| 267 | |
| 268 | /* |
| 269 | * Not for us; forward if possible and desirable. |
| 270 | */ |
| 271 | if (ipforwarding == 0) { |
| 272 | ipstat.ips_cantforward++; |
| 273 | m_freem(m); |
| 274 | } else |
| 275 | ip_forward(m, 0); |
| 276 | goto next; |
| 277 | |
| 278 | ours: |
| 279 | /* |
| 280 | * If offset or IP_MF are set, must reassemble. |
| 281 | * Otherwise, nothing need be done. |
| 282 | * (We could look in the reassembly queue to see |
| 283 | * if the packet was previously fragmented, |
| 284 | * but it's not worth the time; just let them time out.) |
| 285 | */ |
| 286 | if (ip->ip_off &~ IP_DF) { |
| 287 | if (m->m_flags & M_EXT) { /* XXX */ |
| 288 | if ((m = m_pullup(m, sizeof (struct ip))) == 0) { |
| 289 | ipstat.ips_toosmall++; |
| 290 | goto next; |
| 291 | } |
| 292 | ip = mtod(m, struct ip *); |
| 293 | } |
| 294 | /* |
| 295 | * Look for queue of fragments |
| 296 | * of this datagram. |
| 297 | */ |
| 298 | for (fp = ipq.next; fp != &ipq; fp = fp->next) |
| 299 | if (ip->ip_id == fp->ipq_id && |
| 300 | ip->ip_src.s_addr == fp->ipq_src.s_addr && |
| 301 | ip->ip_dst.s_addr == fp->ipq_dst.s_addr && |
| 302 | ip->ip_p == fp->ipq_p) |
| 303 | goto found; |
| 304 | fp = 0; |
| 305 | found: |
| 306 | |
| 307 | /* |
| 308 | * Adjust ip_len to not reflect header, |
| 309 | * set ip_mff if more fragments are expected, |
| 310 | * convert offset of this to bytes. |
| 311 | */ |
| 312 | ip->ip_len -= hlen; |
| 313 | ((struct ipasfrag *)ip)->ipf_mff = 0; |
| 314 | if (ip->ip_off & IP_MF) |
| 315 | ((struct ipasfrag *)ip)->ipf_mff = 1; |
| 316 | ip->ip_off <<= 3; |
| 317 | |
| 318 | /* |
| 319 | * If datagram marked as having more fragments |
| 320 | * or if this is not the first fragment, |
| 321 | * attempt reassembly; if it succeeds, proceed. |
| 322 | */ |
| 323 | if (((struct ipasfrag *)ip)->ipf_mff || ip->ip_off) { |
| 324 | ipstat.ips_fragments++; |
| 325 | ip = ip_reass((struct ipasfrag *)ip, fp); |
| 326 | if (ip == 0) |
| 327 | goto next; |
| 328 | else |
| 329 | ipstat.ips_reassembled++; |
| 330 | m = dtom(ip); |
| 331 | } else |
| 332 | if (fp) |
| 333 | ip_freef(fp); |
| 334 | } else |
| 335 | ip->ip_len -= hlen; |
| 336 | |
| 337 | /* |
| 338 | * Switch out to protocol's input routine. |
| 339 | */ |
| 340 | ipstat.ips_delivered++; |
| 341 | (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); |
| 342 | goto next; |
| 343 | bad: |
| 344 | m_freem(m); |
| 345 | goto next; |
| 346 | } |
| 347 | |
| 348 | /* |
| 349 | * Take incoming datagram fragment and try to |
| 350 | * reassemble it into whole datagram. If a chain for |
| 351 | * reassembly of this datagram already exists, then it |
| 352 | * is given as fp; otherwise have to make a chain. |
| 353 | */ |
| 354 | struct ip * |
| 355 | ip_reass(ip, fp) |
| 356 | register struct ipasfrag *ip; |
| 357 | register struct ipq *fp; |
| 358 | { |
| 359 | register struct mbuf *m = dtom(ip); |
| 360 | register struct ipasfrag *q; |
| 361 | struct mbuf *t; |
| 362 | int hlen = ip->ip_hl << 2; |
| 363 | int i, next; |
| 364 | |
| 365 | /* |
| 366 | * Presence of header sizes in mbufs |
| 367 | * would confuse code below. |
| 368 | */ |
| 369 | m->m_data += hlen; |
| 370 | m->m_len -= hlen; |
| 371 | |
| 372 | /* |
| 373 | * If first fragment to arrive, create a reassembly queue. |
| 374 | */ |
| 375 | if (fp == 0) { |
| 376 | if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL) |
| 377 | goto dropfrag; |
| 378 | fp = mtod(t, struct ipq *); |
| 379 | insque(fp, &ipq); |
| 380 | fp->ipq_ttl = IPFRAGTTL; |
| 381 | fp->ipq_p = ip->ip_p; |
| 382 | fp->ipq_id = ip->ip_id; |
| 383 | fp->ipq_next = fp->ipq_prev = (struct ipasfrag *)fp; |
| 384 | fp->ipq_src = ((struct ip *)ip)->ip_src; |
| 385 | fp->ipq_dst = ((struct ip *)ip)->ip_dst; |
| 386 | q = (struct ipasfrag *)fp; |
| 387 | goto insert; |
| 388 | } |
| 389 | |
| 390 | /* |
| 391 | * Find a segment which begins after this one does. |
| 392 | */ |
| 393 | for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) |
| 394 | if (q->ip_off > ip->ip_off) |
| 395 | break; |
| 396 | |
| 397 | /* |
| 398 | * If there is a preceding segment, it may provide some of |
| 399 | * our data already. If so, drop the data from the incoming |
| 400 | * segment. If it provides all of our data, drop us. |
| 401 | */ |
| 402 | if (q->ipf_prev != (struct ipasfrag *)fp) { |
| 403 | i = q->ipf_prev->ip_off + q->ipf_prev->ip_len - ip->ip_off; |
| 404 | if (i > 0) { |
| 405 | if (i >= ip->ip_len) |
| 406 | goto dropfrag; |
| 407 | m_adj(dtom(ip), i); |
| 408 | ip->ip_off += i; |
| 409 | ip->ip_len -= i; |
| 410 | } |
| 411 | } |
| 412 | |
| 413 | /* |
| 414 | * While we overlap succeeding segments trim them or, |
| 415 | * if they are completely covered, dequeue them. |
| 416 | */ |
| 417 | while (q != (struct ipasfrag *)fp && ip->ip_off + ip->ip_len > q->ip_off) { |
| 418 | i = (ip->ip_off + ip->ip_len) - q->ip_off; |
| 419 | if (i < q->ip_len) { |
| 420 | q->ip_len -= i; |
| 421 | q->ip_off += i; |
| 422 | m_adj(dtom(q), i); |
| 423 | break; |
| 424 | } |
| 425 | q = q->ipf_next; |
| 426 | m_freem(dtom(q->ipf_prev)); |
| 427 | ip_deq(q->ipf_prev); |
| 428 | } |
| 429 | |
| 430 | insert: |
| 431 | /* |
| 432 | * Stick new segment in its place; |
| 433 | * check for complete reassembly. |
| 434 | */ |
| 435 | ip_enq(ip, q->ipf_prev); |
| 436 | next = 0; |
| 437 | for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) { |
| 438 | if (q->ip_off != next) |
| 439 | return (0); |
| 440 | next += q->ip_len; |
| 441 | } |
| 442 | if (q->ipf_prev->ipf_mff) |
| 443 | return (0); |
| 444 | |
| 445 | /* |
| 446 | * Reassembly is complete; concatenate fragments. |
| 447 | */ |
| 448 | q = fp->ipq_next; |
| 449 | m = dtom(q); |
| 450 | t = m->m_next; |
| 451 | m->m_next = 0; |
| 452 | m_cat(m, t); |
| 453 | q = q->ipf_next; |
| 454 | while (q != (struct ipasfrag *)fp) { |
| 455 | t = dtom(q); |
| 456 | q = q->ipf_next; |
| 457 | m_cat(m, t); |
| 458 | } |
| 459 | |
| 460 | /* |
| 461 | * Create header for new ip packet by |
| 462 | * modifying header of first packet; |
| 463 | * dequeue and discard fragment reassembly header. |
| 464 | * Make header visible. |
| 465 | */ |
| 466 | ip = fp->ipq_next; |
| 467 | ip->ip_len = next; |
| 468 | ((struct ip *)ip)->ip_src = fp->ipq_src; |
| 469 | ((struct ip *)ip)->ip_dst = fp->ipq_dst; |
| 470 | remque(fp); |
| 471 | (void) m_free(dtom(fp)); |
| 472 | m = dtom(ip); |
| 473 | m->m_len += (ip->ip_hl << 2); |
| 474 | m->m_data -= (ip->ip_hl << 2); |
| 475 | /* some debugging cruft by sklower, below, will go away soon */ |
| 476 | if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ |
| 477 | register int plen = 0; |
| 478 | for (t = m; m; m = m->m_next) |
| 479 | plen += m->m_len; |
| 480 | t->m_pkthdr.len = plen; |
| 481 | } |
| 482 | return ((struct ip *)ip); |
| 483 | |
| 484 | dropfrag: |
| 485 | ipstat.ips_fragdropped++; |
| 486 | m_freem(m); |
| 487 | return (0); |
| 488 | } |
| 489 | |
| 490 | /* |
| 491 | * Free a fragment reassembly header and all |
| 492 | * associated datagrams. |
| 493 | */ |
| 494 | ip_freef(fp) |
| 495 | struct ipq *fp; |
| 496 | { |
| 497 | register struct ipasfrag *q, *p; |
| 498 | |
| 499 | for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = p) { |
| 500 | p = q->ipf_next; |
| 501 | ip_deq(q); |
| 502 | m_freem(dtom(q)); |
| 503 | } |
| 504 | remque(fp); |
| 505 | (void) m_free(dtom(fp)); |
| 506 | } |
| 507 | |
| 508 | /* |
| 509 | * Put an ip fragment on a reassembly chain. |
| 510 | * Like insque, but pointers in middle of structure. |
| 511 | */ |
| 512 | ip_enq(p, prev) |
| 513 | register struct ipasfrag *p, *prev; |
| 514 | { |
| 515 | |
| 516 | p->ipf_prev = prev; |
| 517 | p->ipf_next = prev->ipf_next; |
| 518 | prev->ipf_next->ipf_prev = p; |
| 519 | prev->ipf_next = p; |
| 520 | } |
| 521 | |
| 522 | /* |
| 523 | * To ip_enq as remque is to insque. |
| 524 | */ |
| 525 | ip_deq(p) |
| 526 | register struct ipasfrag *p; |
| 527 | { |
| 528 | |
| 529 | p->ipf_prev->ipf_next = p->ipf_next; |
| 530 | p->ipf_next->ipf_prev = p->ipf_prev; |
| 531 | } |
| 532 | |
| 533 | /* |
| 534 | * IP timer processing; |
| 535 | * if a timer expires on a reassembly |
| 536 | * queue, discard it. |
| 537 | */ |
| 538 | ip_slowtimo() |
| 539 | { |
| 540 | register struct ipq *fp; |
| 541 | int s = splnet(); |
| 542 | |
| 543 | fp = ipq.next; |
| 544 | if (fp == 0) { |
| 545 | splx(s); |
| 546 | return; |
| 547 | } |
| 548 | while (fp != &ipq) { |
| 549 | --fp->ipq_ttl; |
| 550 | fp = fp->next; |
| 551 | if (fp->prev->ipq_ttl == 0) { |
| 552 | ipstat.ips_fragtimeout++; |
| 553 | ip_freef(fp->prev); |
| 554 | } |
| 555 | } |
| 556 | splx(s); |
| 557 | } |
| 558 | |
| 559 | /* |
| 560 | * Drain off all datagram fragments. |
| 561 | */ |
| 562 | ip_drain() |
| 563 | { |
| 564 | |
| 565 | while (ipq.next != &ipq) { |
| 566 | ipstat.ips_fragdropped++; |
| 567 | ip_freef(ipq.next); |
| 568 | } |
| 569 | } |
| 570 | |
| 571 | extern struct in_ifaddr *ifptoia(); |
| 572 | struct in_ifaddr *ip_rtaddr(); |
| 573 | |
| 574 | /* |
| 575 | * Do option processing on a datagram, |
| 576 | * possibly discarding it if bad options are encountered, |
| 577 | * or forwarding it if source-routed. |
| 578 | * Returns 1 if packet has been forwarded/freed, |
| 579 | * 0 if the packet should be processed further. |
| 580 | */ |
| 581 | ip_dooptions(m) |
| 582 | struct mbuf *m; |
| 583 | { |
| 584 | register struct ip *ip = mtod(m, struct ip *); |
| 585 | register u_char *cp; |
| 586 | register struct ip_timestamp *ipt; |
| 587 | register struct in_ifaddr *ia; |
| 588 | int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; |
| 589 | struct in_addr *sin; |
| 590 | n_time ntime; |
| 591 | |
| 592 | cp = (u_char *)(ip + 1); |
| 593 | cnt = (ip->ip_hl << 2) - sizeof (struct ip); |
| 594 | for (; cnt > 0; cnt -= optlen, cp += optlen) { |
| 595 | opt = cp[IPOPT_OPTVAL]; |
| 596 | if (opt == IPOPT_EOL) |
| 597 | break; |
| 598 | if (opt == IPOPT_NOP) |
| 599 | optlen = 1; |
| 600 | else { |
| 601 | optlen = cp[IPOPT_OLEN]; |
| 602 | if (optlen <= 0 || optlen > cnt) { |
| 603 | code = &cp[IPOPT_OLEN] - (u_char *)ip; |
| 604 | goto bad; |
| 605 | } |
| 606 | } |
| 607 | switch (opt) { |
| 608 | |
| 609 | default: |
| 610 | break; |
| 611 | |
| 612 | /* |
| 613 | * Source routing with record. |
| 614 | * Find interface with current destination address. |
| 615 | * If none on this machine then drop if strictly routed, |
| 616 | * or do nothing if loosely routed. |
| 617 | * Record interface address and bring up next address |
| 618 | * component. If strictly routed make sure next |
| 619 | * address is on directly accessible net. |
| 620 | */ |
| 621 | case IPOPT_LSRR: |
| 622 | case IPOPT_SSRR: |
| 623 | if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { |
| 624 | code = &cp[IPOPT_OFFSET] - (u_char *)ip; |
| 625 | goto bad; |
| 626 | } |
| 627 | ipaddr.sin_addr = ip->ip_dst; |
| 628 | ia = (struct in_ifaddr *) |
| 629 | ifa_ifwithaddr((struct sockaddr *)&ipaddr); |
| 630 | if (ia == 0) { |
| 631 | if (opt == IPOPT_SSRR) { |
| 632 | type = ICMP_UNREACH; |
| 633 | code = ICMP_UNREACH_SRCFAIL; |
| 634 | goto bad; |
| 635 | } |
| 636 | /* |
| 637 | * Loose routing, and not at next destination |
| 638 | * yet; nothing to do except forward. |
| 639 | */ |
| 640 | break; |
| 641 | } |
| 642 | off--; /* 0 origin */ |
| 643 | if (off > optlen - sizeof(struct in_addr)) { |
| 644 | /* |
| 645 | * End of source route. Should be for us. |
| 646 | */ |
| 647 | save_rte(cp, ip->ip_src); |
| 648 | break; |
| 649 | } |
| 650 | /* |
| 651 | * locate outgoing interface |
| 652 | */ |
| 653 | bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, |
| 654 | sizeof(ipaddr.sin_addr)); |
| 655 | if (opt == IPOPT_SSRR) { |
| 656 | #define INA struct in_ifaddr * |
| 657 | #define SA struct sockaddr * |
| 658 | if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0) |
| 659 | ia = in_iaonnetof(in_netof(ipaddr.sin_addr)); |
| 660 | } else |
| 661 | ia = ip_rtaddr(ipaddr.sin_addr); |
| 662 | if (ia == 0) { |
| 663 | type = ICMP_UNREACH; |
| 664 | code = ICMP_UNREACH_SRCFAIL; |
| 665 | goto bad; |
| 666 | } |
| 667 | ip->ip_dst = ipaddr.sin_addr; |
| 668 | bcopy((caddr_t)&(IA_SIN(ia)->sin_addr), |
| 669 | (caddr_t)(cp + off), sizeof(struct in_addr)); |
| 670 | cp[IPOPT_OFFSET] += sizeof(struct in_addr); |
| 671 | forward = 1; |
| 672 | break; |
| 673 | |
| 674 | case IPOPT_RR: |
| 675 | if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { |
| 676 | code = &cp[IPOPT_OFFSET] - (u_char *)ip; |
| 677 | goto bad; |
| 678 | } |
| 679 | /* |
| 680 | * If no space remains, ignore. |
| 681 | */ |
| 682 | off--; /* 0 origin */ |
| 683 | if (off > optlen - sizeof(struct in_addr)) |
| 684 | break; |
| 685 | bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, |
| 686 | sizeof(ipaddr.sin_addr)); |
| 687 | /* |
| 688 | * locate outgoing interface; if we're the destination, |
| 689 | * use the incoming interface (should be same). |
| 690 | */ |
| 691 | if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && |
| 692 | (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { |
| 693 | type = ICMP_UNREACH; |
| 694 | code = ICMP_UNREACH_HOST; |
| 695 | goto bad; |
| 696 | } |
| 697 | bcopy((caddr_t)&(IA_SIN(ia)->sin_addr), |
| 698 | (caddr_t)(cp + off), sizeof(struct in_addr)); |
| 699 | cp[IPOPT_OFFSET] += sizeof(struct in_addr); |
| 700 | break; |
| 701 | |
| 702 | case IPOPT_TS: |
| 703 | code = cp - (u_char *)ip; |
| 704 | ipt = (struct ip_timestamp *)cp; |
| 705 | if (ipt->ipt_len < 5) |
| 706 | goto bad; |
| 707 | if (ipt->ipt_ptr > ipt->ipt_len - sizeof (long)) { |
| 708 | if (++ipt->ipt_oflw == 0) |
| 709 | goto bad; |
| 710 | break; |
| 711 | } |
| 712 | sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); |
| 713 | switch (ipt->ipt_flg) { |
| 714 | |
| 715 | case IPOPT_TS_TSONLY: |
| 716 | break; |
| 717 | |
| 718 | case IPOPT_TS_TSANDADDR: |
| 719 | if (ipt->ipt_ptr + sizeof(n_time) + |
| 720 | sizeof(struct in_addr) > ipt->ipt_len) |
| 721 | goto bad; |
| 722 | ia = ifptoia(m->m_pkthdr.rcvif); |
| 723 | bcopy((caddr_t)&IA_SIN(ia)->sin_addr, |
| 724 | (caddr_t)sin, sizeof(struct in_addr)); |
| 725 | ipt->ipt_ptr += sizeof(struct in_addr); |
| 726 | break; |
| 727 | |
| 728 | case IPOPT_TS_PRESPEC: |
| 729 | if (ipt->ipt_ptr + sizeof(n_time) + |
| 730 | sizeof(struct in_addr) > ipt->ipt_len) |
| 731 | goto bad; |
| 732 | bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr, |
| 733 | sizeof(struct in_addr)); |
| 734 | if (ifa_ifwithaddr((SA)&ipaddr) == 0) |
| 735 | continue; |
| 736 | ipt->ipt_ptr += sizeof(struct in_addr); |
| 737 | break; |
| 738 | |
| 739 | default: |
| 740 | goto bad; |
| 741 | } |
| 742 | ntime = iptime(); |
| 743 | bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1, |
| 744 | sizeof(n_time)); |
| 745 | ipt->ipt_ptr += sizeof(n_time); |
| 746 | } |
| 747 | } |
| 748 | if (forward) { |
| 749 | ip_forward(m, 1); |
| 750 | return (1); |
| 751 | } else |
| 752 | return (0); |
| 753 | bad: |
| 754 | icmp_error(m, type, code); |
| 755 | return (1); |
| 756 | } |
| 757 | |
| 758 | /* |
| 759 | * Given address of next destination (final or next hop), |
| 760 | * return internet address info of interface to be used to get there. |
| 761 | */ |
| 762 | struct in_ifaddr * |
| 763 | ip_rtaddr(dst) |
| 764 | struct in_addr dst; |
| 765 | { |
| 766 | register struct sockaddr_in *sin; |
| 767 | |
| 768 | sin = (struct sockaddr_in *) &ipforward_rt.ro_dst; |
| 769 | |
| 770 | if (ipforward_rt.ro_rt == 0 || dst.s_addr != sin->sin_addr.s_addr) { |
| 771 | if (ipforward_rt.ro_rt) { |
| 772 | RTFREE(ipforward_rt.ro_rt); |
| 773 | ipforward_rt.ro_rt = 0; |
| 774 | } |
| 775 | sin->sin_family = AF_INET; |
| 776 | sin->sin_len = sizeof(*sin); |
| 777 | sin->sin_addr = dst; |
| 778 | |
| 779 | rtalloc(&ipforward_rt); |
| 780 | } |
| 781 | if (ipforward_rt.ro_rt == 0) |
| 782 | return ((struct in_ifaddr *)0); |
| 783 | return ((struct in_ifaddr *) ipforward_rt.ro_rt->rt_ifa); |
| 784 | } |
| 785 | |
| 786 | /* |
| 787 | * Save incoming source route for use in replies, |
| 788 | * to be picked up later by ip_srcroute if the receiver is interested. |
| 789 | */ |
| 790 | save_rte(option, dst) |
| 791 | u_char *option; |
| 792 | struct in_addr dst; |
| 793 | { |
| 794 | unsigned olen; |
| 795 | |
| 796 | olen = option[IPOPT_OLEN]; |
| 797 | #ifdef DIAGNOSTIC |
| 798 | if (ipprintfs) |
| 799 | printf("save_rte: olen %d\n", olen); |
| 800 | #endif |
| 801 | if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) |
| 802 | return; |
| 803 | bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen); |
| 804 | ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); |
| 805 | ip_srcrt.dst = dst; |
| 806 | } |
| 807 | |
| 808 | /* |
| 809 | * Retrieve incoming source route for use in replies, |
| 810 | * in the same form used by setsockopt. |
| 811 | * The first hop is placed before the options, will be removed later. |
| 812 | */ |
| 813 | struct mbuf * |
| 814 | ip_srcroute() |
| 815 | { |
| 816 | register struct in_addr *p, *q; |
| 817 | register struct mbuf *m; |
| 818 | |
| 819 | if (ip_nhops == 0) |
| 820 | return ((struct mbuf *)0); |
| 821 | m = m_get(M_DONTWAIT, MT_SOOPTS); |
| 822 | if (m == 0) |
| 823 | return ((struct mbuf *)0); |
| 824 | |
| 825 | #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) |
| 826 | |
| 827 | /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ |
| 828 | m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + |
| 829 | OPTSIZ; |
| 830 | #ifdef DIAGNOSTIC |
| 831 | if (ipprintfs) |
| 832 | printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); |
| 833 | #endif |
| 834 | |
| 835 | /* |
| 836 | * First save first hop for return route |
| 837 | */ |
| 838 | p = &ip_srcrt.route[ip_nhops - 1]; |
| 839 | *(mtod(m, struct in_addr *)) = *p--; |
| 840 | #ifdef DIAGNOSTIC |
| 841 | if (ipprintfs) |
| 842 | printf(" hops %lx", ntohl(mtod(m, struct in_addr *)->s_addr)); |
| 843 | #endif |
| 844 | |
| 845 | /* |
| 846 | * Copy option fields and padding (nop) to mbuf. |
| 847 | */ |
| 848 | ip_srcrt.nop = IPOPT_NOP; |
| 849 | ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; |
| 850 | bcopy((caddr_t)&ip_srcrt.nop, |
| 851 | mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ); |
| 852 | q = (struct in_addr *)(mtod(m, caddr_t) + |
| 853 | sizeof(struct in_addr) + OPTSIZ); |
| 854 | #undef OPTSIZ |
| 855 | /* |
| 856 | * Record return path as an IP source route, |
| 857 | * reversing the path (pointers are now aligned). |
| 858 | */ |
| 859 | while (p >= ip_srcrt.route) { |
| 860 | #ifdef DIAGNOSTIC |
| 861 | if (ipprintfs) |
| 862 | printf(" %lx", ntohl(q->s_addr)); |
| 863 | #endif |
| 864 | *q++ = *p--; |
| 865 | } |
| 866 | /* |
| 867 | * Last hop goes to final destination. |
| 868 | */ |
| 869 | *q = ip_srcrt.dst; |
| 870 | #ifdef DIAGNOSTIC |
| 871 | if (ipprintfs) |
| 872 | printf(" %lx\n", ntohl(q->s_addr)); |
| 873 | #endif |
| 874 | return (m); |
| 875 | } |
| 876 | |
| 877 | /* |
| 878 | * Strip out IP options, at higher |
| 879 | * level protocol in the kernel. |
| 880 | * Second argument is buffer to which options |
| 881 | * will be moved, and return value is their length. |
| 882 | * XXX should be deleted; last arg currently ignored. |
| 883 | */ |
| 884 | ip_stripoptions(m, mopt) |
| 885 | register struct mbuf *m; |
| 886 | struct mbuf *mopt; |
| 887 | { |
| 888 | register int i; |
| 889 | struct ip *ip = mtod(m, struct ip *); |
| 890 | register caddr_t opts; |
| 891 | int olen; |
| 892 | |
| 893 | olen = (ip->ip_hl<<2) - sizeof (struct ip); |
| 894 | opts = (caddr_t)(ip + 1); |
| 895 | i = m->m_len - (sizeof (struct ip) + olen); |
| 896 | bcopy(opts + olen, opts, (unsigned)i); |
| 897 | m->m_len -= olen; |
| 898 | if (m->m_flags & M_PKTHDR) |
| 899 | m->m_pkthdr.len -= olen; |
| 900 | ip->ip_hl = sizeof(struct ip) >> 2; |
| 901 | } |
| 902 | |
| 903 | u_char inetctlerrmap[PRC_NCMDS] = { |
| 904 | 0, 0, 0, 0, |
| 905 | 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, |
| 906 | EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, |
| 907 | EMSGSIZE, EHOSTUNREACH, 0, 0, |
| 908 | 0, 0, 0, 0, |
| 909 | ENOPROTOOPT |
| 910 | }; |
| 911 | |
| 912 | /* |
| 913 | * Forward a packet. If some error occurs return the sender |
| 914 | * an icmp packet. Note we can't always generate a meaningful |
| 915 | * icmp message because icmp doesn't have a large enough repertoire |
| 916 | * of codes and types. |
| 917 | * |
| 918 | * If not forwarding, just drop the packet. This could be confusing |
| 919 | * if ipforwarding was zero but some routing protocol was advancing |
| 920 | * us as a gateway to somewhere. However, we must let the routing |
| 921 | * protocol deal with that. |
| 922 | * |
| 923 | * The srcrt parameter indicates whether the packet is being forwarded |
| 924 | * via a source route. |
| 925 | */ |
| 926 | ip_forward(m, srcrt) |
| 927 | struct mbuf *m; |
| 928 | int srcrt; |
| 929 | { |
| 930 | register struct ip *ip = mtod(m, struct ip *); |
| 931 | register struct sockaddr_in *sin; |
| 932 | register struct rtentry *rt; |
| 933 | int error, type = 0, code; |
| 934 | struct mbuf *mcopy; |
| 935 | struct in_addr dest; |
| 936 | |
| 937 | dest.s_addr = 0; |
| 938 | #ifdef DIAGNOSTIC |
| 939 | if (ipprintfs) |
| 940 | printf("forward: src %x dst %x ttl %x\n", ip->ip_src, |
| 941 | ip->ip_dst, ip->ip_ttl); |
| 942 | #endif |
| 943 | if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) { |
| 944 | ipstat.ips_cantforward++; |
| 945 | m_freem(m); |
| 946 | return; |
| 947 | } |
| 948 | HTONS(ip->ip_id); |
| 949 | if (ip->ip_ttl <= IPTTLDEC) { |
| 950 | icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest); |
| 951 | return; |
| 952 | } |
| 953 | ip->ip_ttl -= IPTTLDEC; |
| 954 | |
| 955 | sin = (struct sockaddr_in *)&ipforward_rt.ro_dst; |
| 956 | if ((rt = ipforward_rt.ro_rt) == 0 || |
| 957 | ip->ip_dst.s_addr != sin->sin_addr.s_addr) { |
| 958 | if (ipforward_rt.ro_rt) { |
| 959 | RTFREE(ipforward_rt.ro_rt); |
| 960 | ipforward_rt.ro_rt = 0; |
| 961 | } |
| 962 | sin->sin_family = AF_INET; |
| 963 | sin->sin_len = sizeof(*sin); |
| 964 | sin->sin_addr = ip->ip_dst; |
| 965 | |
| 966 | rtalloc(&ipforward_rt); |
| 967 | if (ipforward_rt.ro_rt == 0) { |
| 968 | icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest); |
| 969 | return; |
| 970 | } |
| 971 | rt = ipforward_rt.ro_rt; |
| 972 | } |
| 973 | |
| 974 | /* |
| 975 | * Save at most 64 bytes of the packet in case |
| 976 | * we need to generate an ICMP message to the src. |
| 977 | */ |
| 978 | mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64)); |
| 979 | |
| 980 | #ifdef GATEWAY |
| 981 | ip_ifmatrix[rt->rt_ifp->if_index + |
| 982 | if_index * m->m_pkthdr.rcvif->if_index]++; |
| 983 | #endif |
| 984 | /* |
| 985 | * If forwarding packet using same interface that it came in on, |
| 986 | * perhaps should send a redirect to sender to shortcut a hop. |
| 987 | * Only send redirect if source is sending directly to us, |
| 988 | * and if packet was not source routed (or has any options). |
| 989 | * Also, don't send redirect if forwarding using a default route |
| 990 | * or a route modified by a redirect. |
| 991 | */ |
| 992 | #define satosin(sa) ((struct sockaddr_in *)(sa)) |
| 993 | if (rt->rt_ifp == m->m_pkthdr.rcvif && |
| 994 | (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && |
| 995 | satosin(rt_key(rt))->sin_addr.s_addr != 0 && |
| 996 | ipsendredirects && !srcrt) { |
| 997 | struct in_ifaddr *ia; |
| 998 | u_long src = ntohl(ip->ip_src.s_addr); |
| 999 | u_long dst = ntohl(ip->ip_dst.s_addr); |
| 1000 | |
| 1001 | if ((ia = ifptoia(m->m_pkthdr.rcvif)) && |
| 1002 | (src & ia->ia_subnetmask) == ia->ia_subnet) { |
| 1003 | if (rt->rt_flags & RTF_GATEWAY) |
| 1004 | dest = satosin(rt->rt_gateway)->sin_addr; |
| 1005 | else |
| 1006 | dest = ip->ip_dst; |
| 1007 | /* |
| 1008 | * If the destination is reached by a route to host, |
| 1009 | * is on a subnet of a local net, or is directly |
| 1010 | * on the attached net (!), use host redirect. |
| 1011 | * (We may be the correct first hop for other subnets.) |
| 1012 | */ |
| 1013 | #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa)) |
| 1014 | type = ICMP_REDIRECT; |
| 1015 | if ((rt->rt_flags & RTF_HOST) || |
| 1016 | (rt->rt_flags & RTF_GATEWAY) == 0) |
| 1017 | code = ICMP_REDIRECT_HOST; |
| 1018 | else if (RTA(rt)->ia_subnetmask != RTA(rt)->ia_netmask && |
| 1019 | (dst & RTA(rt)->ia_netmask) == RTA(rt)->ia_net) |
| 1020 | code = ICMP_REDIRECT_HOST; |
| 1021 | else |
| 1022 | code = ICMP_REDIRECT_NET; |
| 1023 | #ifdef DIAGNOSTIC |
| 1024 | if (ipprintfs) |
| 1025 | printf("redirect (%d) to %x\n", code, dest.s_addr); |
| 1026 | #endif |
| 1027 | } |
| 1028 | } |
| 1029 | |
| 1030 | error = ip_output(m, (struct mbuf *)0, &ipforward_rt, IP_FORWARDING); |
| 1031 | if (error) |
| 1032 | ipstat.ips_cantforward++; |
| 1033 | else { |
| 1034 | ipstat.ips_forward++; |
| 1035 | if (type) |
| 1036 | ipstat.ips_redirectsent++; |
| 1037 | else { |
| 1038 | if (mcopy) |
| 1039 | m_freem(mcopy); |
| 1040 | return; |
| 1041 | } |
| 1042 | } |
| 1043 | if (mcopy == NULL) |
| 1044 | return; |
| 1045 | switch (error) { |
| 1046 | |
| 1047 | case 0: /* forwarded, but need redirect */ |
| 1048 | /* type, code set above */ |
| 1049 | break; |
| 1050 | |
| 1051 | case ENETUNREACH: /* shouldn't happen, checked above */ |
| 1052 | case EHOSTUNREACH: |
| 1053 | case ENETDOWN: |
| 1054 | case EHOSTDOWN: |
| 1055 | default: |
| 1056 | type = ICMP_UNREACH; |
| 1057 | code = ICMP_UNREACH_HOST; |
| 1058 | break; |
| 1059 | |
| 1060 | case EMSGSIZE: |
| 1061 | type = ICMP_UNREACH; |
| 1062 | code = ICMP_UNREACH_NEEDFRAG; |
| 1063 | ipstat.ips_cantfrag++; |
| 1064 | break; |
| 1065 | |
| 1066 | case ENOBUFS: |
| 1067 | type = ICMP_SOURCEQUENCH; |
| 1068 | code = 0; |
| 1069 | break; |
| 1070 | } |
| 1071 | icmp_error(mcopy, type, code, dest); |
| 1072 | } |