| 1 | /* $NetBSD: ip_icmp.c,v 1.153 2016/10/25 02:45:09 ozaki-r Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * 3. Neither the name of the project nor the names of its contributors |
| 16 | * may be used to endorse or promote products derived from this software |
| 17 | * without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND |
| 20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE |
| 23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 29 | * SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | /*- |
| 33 | * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc. |
| 34 | * All rights reserved. |
| 35 | * |
| 36 | * This code is derived from software contributed to The NetBSD Foundation |
| 37 | * by Public Access Networks Corporation ("Panix"). It was developed under |
| 38 | * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. |
| 39 | * |
| 40 | * This code is derived from software contributed to The NetBSD Foundation |
| 41 | * by Jason R. Thorpe of Zembu Labs, Inc. |
| 42 | * |
| 43 | * Redistribution and use in source and binary forms, with or without |
| 44 | * modification, are permitted provided that the following conditions |
| 45 | * are met: |
| 46 | * 1. Redistributions of source code must retain the above copyright |
| 47 | * notice, this list of conditions and the following disclaimer. |
| 48 | * 2. Redistributions in binary form must reproduce the above copyright |
| 49 | * notice, this list of conditions and the following disclaimer in the |
| 50 | * documentation and/or other materials provided with the distribution. |
| 51 | * |
| 52 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 53 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 54 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 55 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 56 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 57 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 58 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 59 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 60 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 61 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 62 | * POSSIBILITY OF SUCH DAMAGE. |
| 63 | */ |
| 64 | |
| 65 | /* |
| 66 | * Copyright (c) 1982, 1986, 1988, 1993 |
| 67 | * The Regents of the University of California. All rights reserved. |
| 68 | * |
| 69 | * Redistribution and use in source and binary forms, with or without |
| 70 | * modification, are permitted provided that the following conditions |
| 71 | * are met: |
| 72 | * 1. Redistributions of source code must retain the above copyright |
| 73 | * notice, this list of conditions and the following disclaimer. |
| 74 | * 2. Redistributions in binary form must reproduce the above copyright |
| 75 | * notice, this list of conditions and the following disclaimer in the |
| 76 | * documentation and/or other materials provided with the distribution. |
| 77 | * 3. Neither the name of the University nor the names of its contributors |
| 78 | * may be used to endorse or promote products derived from this software |
| 79 | * without specific prior written permission. |
| 80 | * |
| 81 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 82 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 83 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 84 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 85 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 86 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 87 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 88 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 89 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 90 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 91 | * SUCH DAMAGE. |
| 92 | * |
| 93 | * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 |
| 94 | */ |
| 95 | |
| 96 | #include <sys/cdefs.h> |
| 97 | __KERNEL_RCSID(0, "$NetBSD: ip_icmp.c,v 1.153 2016/10/25 02:45:09 ozaki-r Exp $" ); |
| 98 | |
| 99 | #ifdef _KERNEL_OPT |
| 100 | #include "opt_ipsec.h" |
| 101 | #endif |
| 102 | |
| 103 | #include <sys/param.h> |
| 104 | #include <sys/systm.h> |
| 105 | #include <sys/mbuf.h> |
| 106 | #include <sys/protosw.h> |
| 107 | #include <sys/socket.h> |
| 108 | #include <sys/kmem.h> |
| 109 | #include <sys/time.h> |
| 110 | #include <sys/kernel.h> |
| 111 | #include <sys/syslog.h> |
| 112 | #include <sys/sysctl.h> |
| 113 | |
| 114 | #include <net/if.h> |
| 115 | #include <net/route.h> |
| 116 | |
| 117 | #include <netinet/in.h> |
| 118 | #include <netinet/in_systm.h> |
| 119 | #include <netinet/in_var.h> |
| 120 | #include <netinet/ip.h> |
| 121 | #include <netinet/ip_icmp.h> |
| 122 | #include <netinet/ip_var.h> |
| 123 | #include <netinet/in_pcb.h> |
| 124 | #include <netinet/in_proto.h> |
| 125 | #include <netinet/icmp_var.h> |
| 126 | #include <netinet/icmp_private.h> |
| 127 | |
| 128 | #ifdef IPSEC |
| 129 | #include <netipsec/ipsec.h> |
| 130 | #include <netipsec/key.h> |
| 131 | #endif /* IPSEC*/ |
| 132 | |
| 133 | /* |
| 134 | * ICMP routines: error generation, receive packet processing, and |
| 135 | * routines to turnaround packets back to the originator, and |
| 136 | * host table maintenance routines. |
| 137 | */ |
| 138 | |
| 139 | int icmpmaskrepl = 0; |
| 140 | int icmpbmcastecho = 0; |
| 141 | #ifdef ICMPPRINTFS |
| 142 | int icmpprintfs = 0; |
| 143 | #endif |
| 144 | int icmpreturndatabytes = 8; |
| 145 | |
| 146 | percpu_t *icmpstat_percpu; |
| 147 | |
| 148 | /* |
| 149 | * List of callbacks to notify when Path MTU changes are made. |
| 150 | */ |
| 151 | struct icmp_mtudisc_callback { |
| 152 | LIST_ENTRY(icmp_mtudisc_callback) mc_list; |
| 153 | void (*mc_func)(struct in_addr); |
| 154 | }; |
| 155 | |
| 156 | LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks = |
| 157 | LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks); |
| 158 | |
| 159 | #if 0 |
| 160 | static u_int ip_next_mtu(u_int, int); |
| 161 | #else |
| 162 | /*static*/ u_int ip_next_mtu(u_int, int); |
| 163 | #endif |
| 164 | |
| 165 | extern int icmperrppslim; |
| 166 | static int icmperrpps_count = 0; |
| 167 | static struct timeval icmperrppslim_last; |
| 168 | static int icmp_rediraccept = 1; |
| 169 | static int icmp_redirtimeout = 600; |
| 170 | static struct rttimer_queue *icmp_redirect_timeout_q = NULL; |
| 171 | |
| 172 | static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); |
| 173 | static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); |
| 174 | |
| 175 | static void sysctl_netinet_icmp_setup(struct sysctllog **); |
| 176 | |
| 177 | void |
| 178 | icmp_init(void) |
| 179 | { |
| 180 | |
| 181 | sysctl_netinet_icmp_setup(NULL); |
| 182 | |
| 183 | /* |
| 184 | * This is only useful if the user initializes redirtimeout to |
| 185 | * something other than zero. |
| 186 | */ |
| 187 | if (icmp_redirtimeout != 0) { |
| 188 | icmp_redirect_timeout_q = |
| 189 | rt_timer_queue_create(icmp_redirtimeout); |
| 190 | } |
| 191 | |
| 192 | icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); |
| 193 | } |
| 194 | |
| 195 | /* |
| 196 | * Register a Path MTU Discovery callback. |
| 197 | */ |
| 198 | void |
| 199 | icmp_mtudisc_callback_register(void (*func)(struct in_addr)) |
| 200 | { |
| 201 | struct icmp_mtudisc_callback *mc; |
| 202 | |
| 203 | for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; |
| 204 | mc = LIST_NEXT(mc, mc_list)) { |
| 205 | if (mc->mc_func == func) |
| 206 | return; |
| 207 | } |
| 208 | |
| 209 | mc = kmem_alloc(sizeof(*mc), KM_SLEEP); |
| 210 | mc->mc_func = func; |
| 211 | LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, mc, mc_list); |
| 212 | } |
| 213 | |
| 214 | /* |
| 215 | * Generate an error packet of type error |
| 216 | * in response to bad packet ip. |
| 217 | */ |
| 218 | void |
| 219 | icmp_error(struct mbuf *n, int type, int code, n_long dest, |
| 220 | int destmtu) |
| 221 | { |
| 222 | struct ip *oip = mtod(n, struct ip *), *nip; |
| 223 | unsigned oiplen = oip->ip_hl << 2; |
| 224 | struct icmp *icp; |
| 225 | struct mbuf *m; |
| 226 | struct m_tag *mtag; |
| 227 | unsigned icmplen, mblen; |
| 228 | |
| 229 | #ifdef ICMPPRINTFS |
| 230 | if (icmpprintfs) |
| 231 | printf("icmp_error(%p, type:%d, code:%d)\n" , oip, type, code); |
| 232 | #endif |
| 233 | if (type != ICMP_REDIRECT) |
| 234 | ICMP_STATINC(ICMP_STAT_ERROR); |
| 235 | /* |
| 236 | * Don't send error if the original packet was encrypted. |
| 237 | * Don't send error if not the first fragment of message. |
| 238 | * Don't error if the old packet protocol was ICMP |
| 239 | * error message, only known informational types. |
| 240 | */ |
| 241 | if (n->m_flags & M_DECRYPTED) |
| 242 | goto freeit; |
| 243 | if (oip->ip_off &~ htons(IP_MF|IP_DF)) |
| 244 | goto freeit; |
| 245 | if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && |
| 246 | n->m_len >= oiplen + ICMP_MINLEN && |
| 247 | !ICMP_INFOTYPE(((struct icmp *)((char *)oip + oiplen))->icmp_type)) { |
| 248 | ICMP_STATINC(ICMP_STAT_OLDICMP); |
| 249 | goto freeit; |
| 250 | } |
| 251 | /* Don't send error in response to a multicast or broadcast packet */ |
| 252 | if (n->m_flags & (M_BCAST|M_MCAST)) |
| 253 | goto freeit; |
| 254 | |
| 255 | /* |
| 256 | * First, do a rate limitation check. |
| 257 | */ |
| 258 | if (icmp_ratelimit(&oip->ip_src, type, code)) { |
| 259 | /* XXX stat */ |
| 260 | goto freeit; |
| 261 | } |
| 262 | |
| 263 | /* |
| 264 | * Now, formulate icmp message |
| 265 | */ |
| 266 | icmplen = oiplen + min(icmpreturndatabytes, |
| 267 | ntohs(oip->ip_len) - oiplen); |
| 268 | /* |
| 269 | * Defend against mbuf chains shorter than oip->ip_len - oiplen: |
| 270 | */ |
| 271 | mblen = 0; |
| 272 | for (m = n; m && (mblen < icmplen); m = m->m_next) |
| 273 | mblen += m->m_len; |
| 274 | icmplen = min(mblen, icmplen); |
| 275 | |
| 276 | /* |
| 277 | * As we are not required to return everything we have, |
| 278 | * we return whatever we can return at ease. |
| 279 | * |
| 280 | * Note that ICMP datagrams longer than 576 octets are out of spec |
| 281 | * according to RFC1812; the limit on icmpreturndatabytes below in |
| 282 | * icmp_sysctl will keep things below that limit. |
| 283 | */ |
| 284 | |
| 285 | KASSERT(ICMP_MINLEN <= MCLBYTES); |
| 286 | |
| 287 | if (icmplen + ICMP_MINLEN > MCLBYTES) |
| 288 | icmplen = MCLBYTES - ICMP_MINLEN; |
| 289 | |
| 290 | m = m_gethdr(M_DONTWAIT, MT_HEADER); |
| 291 | if (m && (icmplen + ICMP_MINLEN > MHLEN)) { |
| 292 | MCLGET(m, M_DONTWAIT); |
| 293 | if ((m->m_flags & M_EXT) == 0) { |
| 294 | m_freem(m); |
| 295 | m = NULL; |
| 296 | } |
| 297 | } |
| 298 | if (m == NULL) |
| 299 | goto freeit; |
| 300 | MCLAIM(m, n->m_owner); |
| 301 | m->m_len = icmplen + ICMP_MINLEN; |
| 302 | if ((m->m_flags & M_EXT) == 0) |
| 303 | MH_ALIGN(m, m->m_len); |
| 304 | else { |
| 305 | m->m_data += sizeof(struct ip); |
| 306 | m->m_len -= sizeof(struct ip); |
| 307 | } |
| 308 | icp = mtod(m, struct icmp *); |
| 309 | if ((u_int)type > ICMP_MAXTYPE) |
| 310 | panic("icmp_error" ); |
| 311 | ICMP_STATINC(ICMP_STAT_OUTHIST + type); |
| 312 | icp->icmp_type = type; |
| 313 | if (type == ICMP_REDIRECT) |
| 314 | icp->icmp_gwaddr.s_addr = dest; |
| 315 | else { |
| 316 | icp->icmp_void = 0; |
| 317 | /* |
| 318 | * The following assignments assume an overlay with the |
| 319 | * zeroed icmp_void field. |
| 320 | */ |
| 321 | if (type == ICMP_PARAMPROB) { |
| 322 | icp->icmp_pptr = code; |
| 323 | code = 0; |
| 324 | } else if (type == ICMP_UNREACH && |
| 325 | code == ICMP_UNREACH_NEEDFRAG && destmtu) |
| 326 | icp->icmp_nextmtu = htons(destmtu); |
| 327 | } |
| 328 | |
| 329 | icp->icmp_code = code; |
| 330 | m_copydata(n, 0, icmplen, (void *)&icp->icmp_ip); |
| 331 | |
| 332 | /* |
| 333 | * Now, copy old ip header (without options) |
| 334 | * in front of icmp message. |
| 335 | */ |
| 336 | if ((m->m_flags & M_EXT) == 0 && |
| 337 | m->m_data - sizeof(struct ip) < m->m_pktdat) |
| 338 | panic("icmp len" ); |
| 339 | m->m_data -= sizeof(struct ip); |
| 340 | m->m_len += sizeof(struct ip); |
| 341 | m->m_pkthdr.len = m->m_len; |
| 342 | m_copy_rcvif(m, n); |
| 343 | nip = mtod(m, struct ip *); |
| 344 | /* ip_v set in ip_output */ |
| 345 | nip->ip_hl = sizeof(struct ip) >> 2; |
| 346 | nip->ip_tos = 0; |
| 347 | nip->ip_len = htons(m->m_len); |
| 348 | /* ip_id set in ip_output */ |
| 349 | nip->ip_off = htons(0); |
| 350 | /* ip_ttl set in icmp_reflect */ |
| 351 | nip->ip_p = IPPROTO_ICMP; |
| 352 | nip->ip_src = oip->ip_src; |
| 353 | nip->ip_dst = oip->ip_dst; |
| 354 | /* move PF m_tag to new packet, if it exists */ |
| 355 | mtag = m_tag_find(n, PACKET_TAG_PF, NULL); |
| 356 | if (mtag != NULL) { |
| 357 | m_tag_unlink(n, mtag); |
| 358 | m_tag_prepend(m, mtag); |
| 359 | } |
| 360 | icmp_reflect(m); |
| 361 | |
| 362 | freeit: |
| 363 | m_freem(n); |
| 364 | } |
| 365 | |
| 366 | struct sockaddr_in icmpsrc = { |
| 367 | .sin_len = sizeof (struct sockaddr_in), |
| 368 | .sin_family = AF_INET, |
| 369 | }; |
| 370 | static struct sockaddr_in icmpdst = { |
| 371 | .sin_len = sizeof (struct sockaddr_in), |
| 372 | .sin_family = AF_INET, |
| 373 | }; |
| 374 | static struct sockaddr_in icmpgw = { |
| 375 | .sin_len = sizeof (struct sockaddr_in), |
| 376 | .sin_family = AF_INET, |
| 377 | }; |
| 378 | struct sockaddr_in icmpmask = { |
| 379 | .sin_len = 8, |
| 380 | .sin_family = 0, |
| 381 | }; |
| 382 | |
| 383 | /* |
| 384 | * Process a received ICMP message. |
| 385 | */ |
| 386 | void |
| 387 | icmp_input(struct mbuf *m, ...) |
| 388 | { |
| 389 | int proto; |
| 390 | struct icmp *icp; |
| 391 | struct ip *ip = mtod(m, struct ip *); |
| 392 | int icmplen; |
| 393 | int i; |
| 394 | struct in_ifaddr *ia; |
| 395 | void *(*ctlfunc)(int, const struct sockaddr *, void *); |
| 396 | int code; |
| 397 | int hlen; |
| 398 | va_list ap; |
| 399 | struct rtentry *rt; |
| 400 | |
| 401 | va_start(ap, m); |
| 402 | hlen = va_arg(ap, int); |
| 403 | proto = va_arg(ap, int); |
| 404 | va_end(ap); |
| 405 | |
| 406 | /* |
| 407 | * Locate icmp structure in mbuf, and check |
| 408 | * that not corrupted and of at least minimum length. |
| 409 | */ |
| 410 | icmplen = ntohs(ip->ip_len) - hlen; |
| 411 | #ifdef ICMPPRINTFS |
| 412 | if (icmpprintfs) { |
| 413 | char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; |
| 414 | printf("icmp_input from `%s' to `%s', len %d\n" , |
| 415 | IN_PRINT(sbuf, &ip->ip_src), IN_PRINT(dbuf, &ip->ip_dst), |
| 416 | icmplen); |
| 417 | } |
| 418 | #endif |
| 419 | if (icmplen < ICMP_MINLEN) { |
| 420 | ICMP_STATINC(ICMP_STAT_TOOSHORT); |
| 421 | goto freeit; |
| 422 | } |
| 423 | i = hlen + min(icmplen, ICMP_ADVLENMIN); |
| 424 | if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == NULL) { |
| 425 | ICMP_STATINC(ICMP_STAT_TOOSHORT); |
| 426 | return; |
| 427 | } |
| 428 | ip = mtod(m, struct ip *); |
| 429 | m->m_len -= hlen; |
| 430 | m->m_data += hlen; |
| 431 | icp = mtod(m, struct icmp *); |
| 432 | /* Don't need to assert alignment, here. */ |
| 433 | if (in_cksum(m, icmplen)) { |
| 434 | ICMP_STATINC(ICMP_STAT_CHECKSUM); |
| 435 | goto freeit; |
| 436 | } |
| 437 | m->m_len += hlen; |
| 438 | m->m_data -= hlen; |
| 439 | |
| 440 | #ifdef ICMPPRINTFS |
| 441 | /* |
| 442 | * Message type specific processing. |
| 443 | */ |
| 444 | if (icmpprintfs) |
| 445 | printf("icmp_input(type:%d, code:%d)\n" , icp->icmp_type, |
| 446 | icp->icmp_code); |
| 447 | #endif |
| 448 | if (icp->icmp_type > ICMP_MAXTYPE) |
| 449 | goto raw; |
| 450 | ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); |
| 451 | code = icp->icmp_code; |
| 452 | switch (icp->icmp_type) { |
| 453 | |
| 454 | case ICMP_UNREACH: |
| 455 | switch (code) { |
| 456 | case ICMP_UNREACH_PROTOCOL: |
| 457 | code = PRC_UNREACH_PROTOCOL; |
| 458 | break; |
| 459 | |
| 460 | case ICMP_UNREACH_PORT: |
| 461 | code = PRC_UNREACH_PORT; |
| 462 | break; |
| 463 | |
| 464 | case ICMP_UNREACH_SRCFAIL: |
| 465 | code = PRC_UNREACH_SRCFAIL; |
| 466 | break; |
| 467 | |
| 468 | case ICMP_UNREACH_NEEDFRAG: |
| 469 | code = PRC_MSGSIZE; |
| 470 | break; |
| 471 | |
| 472 | case ICMP_UNREACH_NET: |
| 473 | case ICMP_UNREACH_NET_UNKNOWN: |
| 474 | case ICMP_UNREACH_NET_PROHIB: |
| 475 | case ICMP_UNREACH_TOSNET: |
| 476 | code = PRC_UNREACH_NET; |
| 477 | break; |
| 478 | |
| 479 | case ICMP_UNREACH_HOST: |
| 480 | case ICMP_UNREACH_HOST_UNKNOWN: |
| 481 | case ICMP_UNREACH_ISOLATED: |
| 482 | case ICMP_UNREACH_HOST_PROHIB: |
| 483 | case ICMP_UNREACH_TOSHOST: |
| 484 | case ICMP_UNREACH_ADMIN_PROHIBIT: |
| 485 | case ICMP_UNREACH_HOST_PREC: |
| 486 | case ICMP_UNREACH_PREC_CUTOFF: |
| 487 | code = PRC_UNREACH_HOST; |
| 488 | break; |
| 489 | |
| 490 | default: |
| 491 | goto badcode; |
| 492 | } |
| 493 | goto deliver; |
| 494 | |
| 495 | case ICMP_TIMXCEED: |
| 496 | if (code > 1) |
| 497 | goto badcode; |
| 498 | code += PRC_TIMXCEED_INTRANS; |
| 499 | goto deliver; |
| 500 | |
| 501 | case ICMP_PARAMPROB: |
| 502 | if (code > 1) |
| 503 | goto badcode; |
| 504 | code = PRC_PARAMPROB; |
| 505 | goto deliver; |
| 506 | |
| 507 | case ICMP_SOURCEQUENCH: |
| 508 | if (code) |
| 509 | goto badcode; |
| 510 | code = PRC_QUENCH; |
| 511 | goto deliver; |
| 512 | |
| 513 | deliver: |
| 514 | /* |
| 515 | * Problem with datagram; advise higher level routines. |
| 516 | */ |
| 517 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || |
| 518 | icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { |
| 519 | ICMP_STATINC(ICMP_STAT_BADLEN); |
| 520 | goto freeit; |
| 521 | } |
| 522 | if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) |
| 523 | goto badcode; |
| 524 | #ifdef ICMPPRINTFS |
| 525 | if (icmpprintfs) |
| 526 | printf("deliver to protocol %d\n" , icp->icmp_ip.ip_p); |
| 527 | #endif |
| 528 | icmpsrc.sin_addr = icp->icmp_ip.ip_dst; |
| 529 | ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; |
| 530 | if (ctlfunc) |
| 531 | (void) (*ctlfunc)(code, sintosa(&icmpsrc), |
| 532 | &icp->icmp_ip); |
| 533 | break; |
| 534 | |
| 535 | badcode: |
| 536 | ICMP_STATINC(ICMP_STAT_BADCODE); |
| 537 | break; |
| 538 | |
| 539 | case ICMP_ECHO: |
| 540 | if (!icmpbmcastecho && |
| 541 | (m->m_flags & (M_MCAST | M_BCAST)) != 0) { |
| 542 | ICMP_STATINC(ICMP_STAT_BMCASTECHO); |
| 543 | break; |
| 544 | } |
| 545 | icp->icmp_type = ICMP_ECHOREPLY; |
| 546 | goto reflect; |
| 547 | |
| 548 | case ICMP_TSTAMP: |
| 549 | if (icmplen < ICMP_TSLEN) { |
| 550 | ICMP_STATINC(ICMP_STAT_BADLEN); |
| 551 | break; |
| 552 | } |
| 553 | if (!icmpbmcastecho && |
| 554 | (m->m_flags & (M_MCAST | M_BCAST)) != 0) { |
| 555 | ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); |
| 556 | break; |
| 557 | } |
| 558 | icp->icmp_type = ICMP_TSTAMPREPLY; |
| 559 | icp->icmp_rtime = iptime(); |
| 560 | icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ |
| 561 | goto reflect; |
| 562 | |
| 563 | case ICMP_MASKREQ: { |
| 564 | struct ifnet *rcvif; |
| 565 | int s, ss; |
| 566 | struct ifaddr *ifa; |
| 567 | |
| 568 | if (icmpmaskrepl == 0) |
| 569 | break; |
| 570 | /* |
| 571 | * We are not able to respond with all ones broadcast |
| 572 | * unless we receive it over a point-to-point interface. |
| 573 | */ |
| 574 | if (icmplen < ICMP_MASKLEN) { |
| 575 | ICMP_STATINC(ICMP_STAT_BADLEN); |
| 576 | break; |
| 577 | } |
| 578 | if (ip->ip_dst.s_addr == INADDR_BROADCAST || |
| 579 | in_nullhost(ip->ip_dst)) |
| 580 | icmpdst.sin_addr = ip->ip_src; |
| 581 | else |
| 582 | icmpdst.sin_addr = ip->ip_dst; |
| 583 | ss = pserialize_read_enter(); |
| 584 | rcvif = m_get_rcvif(m, &s); |
| 585 | ifa = ifaof_ifpforaddr(sintosa(&icmpdst), rcvif); |
| 586 | m_put_rcvif(rcvif, &s); |
| 587 | if (ifa == NULL) { |
| 588 | pserialize_read_exit(ss); |
| 589 | break; |
| 590 | } |
| 591 | ia = ifatoia(ifa); |
| 592 | icp->icmp_type = ICMP_MASKREPLY; |
| 593 | icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; |
| 594 | if (in_nullhost(ip->ip_src)) { |
| 595 | if (ia->ia_ifp->if_flags & IFF_BROADCAST) |
| 596 | ip->ip_src = ia->ia_broadaddr.sin_addr; |
| 597 | else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) |
| 598 | ip->ip_src = ia->ia_dstaddr.sin_addr; |
| 599 | } |
| 600 | pserialize_read_exit(ss); |
| 601 | reflect: |
| 602 | { |
| 603 | uint64_t *icps = percpu_getref(icmpstat_percpu); |
| 604 | icps[ICMP_STAT_REFLECT]++; |
| 605 | icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; |
| 606 | percpu_putref(icmpstat_percpu); |
| 607 | } |
| 608 | icmp_reflect(m); |
| 609 | return; |
| 610 | } |
| 611 | |
| 612 | case ICMP_REDIRECT: |
| 613 | if (code > 3) |
| 614 | goto badcode; |
| 615 | if (icmp_rediraccept == 0) |
| 616 | goto freeit; |
| 617 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || |
| 618 | icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { |
| 619 | ICMP_STATINC(ICMP_STAT_BADLEN); |
| 620 | break; |
| 621 | } |
| 622 | /* |
| 623 | * Short circuit routing redirects to force |
| 624 | * immediate change in the kernel's routing |
| 625 | * tables. The message is also handed to anyone |
| 626 | * listening on a raw socket (e.g. the routing |
| 627 | * daemon for use in updating its tables). |
| 628 | */ |
| 629 | icmpgw.sin_addr = ip->ip_src; |
| 630 | icmpdst.sin_addr = icp->icmp_gwaddr; |
| 631 | #ifdef ICMPPRINTFS |
| 632 | if (icmpprintfs) { |
| 633 | char gbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; |
| 634 | printf("redirect dst `%s' to `%s'\n" , |
| 635 | IN_PRINT(dbuf, &icp->icmp_ip.ip_dst), |
| 636 | IN_PRINT(gbuf, &icp->icmp_gwaddr)); |
| 637 | } |
| 638 | #endif |
| 639 | icmpsrc.sin_addr = icp->icmp_ip.ip_dst; |
| 640 | rt = NULL; |
| 641 | rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), |
| 642 | NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); |
| 643 | if (rt != NULL && icmp_redirtimeout != 0) { |
| 644 | i = rt_timer_add(rt, icmp_redirect_timeout, |
| 645 | icmp_redirect_timeout_q); |
| 646 | if (i) { |
| 647 | char buf[INET_ADDRSTRLEN]; |
| 648 | log(LOG_ERR, "ICMP: redirect failed to " |
| 649 | "register timeout for route to %s, " |
| 650 | "code %d\n" , |
| 651 | IN_PRINT(buf, &icp->icmp_ip.ip_dst), i); |
| 652 | } |
| 653 | } |
| 654 | if (rt != NULL) |
| 655 | rtfree(rt); |
| 656 | |
| 657 | pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); |
| 658 | #if defined(IPSEC) |
| 659 | if (ipsec_used) |
| 660 | key_sa_routechange((struct sockaddr *)&icmpsrc); |
| 661 | #endif |
| 662 | break; |
| 663 | |
| 664 | /* |
| 665 | * No kernel processing for the following; |
| 666 | * just fall through to send to raw listener. |
| 667 | */ |
| 668 | case ICMP_ECHOREPLY: |
| 669 | case ICMP_ROUTERADVERT: |
| 670 | case ICMP_ROUTERSOLICIT: |
| 671 | case ICMP_TSTAMPREPLY: |
| 672 | case ICMP_IREQREPLY: |
| 673 | case ICMP_MASKREPLY: |
| 674 | default: |
| 675 | break; |
| 676 | } |
| 677 | |
| 678 | raw: |
| 679 | rip_input(m, hlen, proto); |
| 680 | return; |
| 681 | |
| 682 | freeit: |
| 683 | m_freem(m); |
| 684 | return; |
| 685 | } |
| 686 | |
| 687 | /* |
| 688 | * Reflect the ip packet back to the source |
| 689 | */ |
| 690 | void |
| 691 | icmp_reflect(struct mbuf *m) |
| 692 | { |
| 693 | struct ip *ip = mtod(m, struct ip *); |
| 694 | struct in_ifaddr *ia; |
| 695 | struct ifaddr *ifa; |
| 696 | struct sockaddr_in *sin; |
| 697 | struct in_addr t; |
| 698 | struct mbuf *opts = NULL; |
| 699 | int optlen = (ip->ip_hl << 2) - sizeof(struct ip); |
| 700 | struct ifnet *rcvif; |
| 701 | struct psref psref, psref_ia; |
| 702 | int s; |
| 703 | int bound; |
| 704 | |
| 705 | bound = curlwp_bind(); |
| 706 | |
| 707 | if (!in_canforward(ip->ip_src) && |
| 708 | ((ip->ip_src.s_addr & IN_CLASSA_NET) != |
| 709 | htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { |
| 710 | m_freem(m); /* Bad return address */ |
| 711 | goto done; /* ip_output() will check for broadcast */ |
| 712 | } |
| 713 | t = ip->ip_dst; |
| 714 | ip->ip_dst = ip->ip_src; |
| 715 | /* |
| 716 | * If the incoming packet was addressed directly to us, use |
| 717 | * dst as the src for the reply. Otherwise (broadcast or |
| 718 | * anonymous), use an address which corresponds to the |
| 719 | * incoming interface, with a preference for the address which |
| 720 | * corresponds to the route to the destination of the ICMP. |
| 721 | */ |
| 722 | |
| 723 | /* Look for packet addressed to us */ |
| 724 | ia = in_get_ia_psref(t, &psref_ia); |
| 725 | if (ia && (ia->ia4_flags & IN_IFF_NOTREADY)) { |
| 726 | ia4_release(ia, &psref_ia); |
| 727 | ia = NULL; |
| 728 | } |
| 729 | |
| 730 | rcvif = m_get_rcvif_psref(m, &psref); |
| 731 | |
| 732 | /* look for packet sent to broadcast address */ |
| 733 | if (ia == NULL && rcvif && |
| 734 | (rcvif->if_flags & IFF_BROADCAST)) { |
| 735 | s = pserialize_read_enter(); |
| 736 | IFADDR_READER_FOREACH(ifa, rcvif) { |
| 737 | if (ifa->ifa_addr->sa_family != AF_INET) |
| 738 | continue; |
| 739 | if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { |
| 740 | ia = ifatoia(ifa); |
| 741 | if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0) |
| 742 | break; |
| 743 | ia = NULL; |
| 744 | } |
| 745 | } |
| 746 | if (ia != NULL) |
| 747 | ia4_acquire(ia, &psref_ia); |
| 748 | pserialize_read_exit(s); |
| 749 | } |
| 750 | |
| 751 | sin = ia ? &ia->ia_addr : NULL; |
| 752 | |
| 753 | icmpdst.sin_addr = t; |
| 754 | |
| 755 | /* |
| 756 | * if the packet is addressed somewhere else, compute the |
| 757 | * source address for packets routed back to the source, and |
| 758 | * use that, if it's an address on the interface which |
| 759 | * received the packet |
| 760 | */ |
| 761 | if (sin == NULL && rcvif) { |
| 762 | struct sockaddr_in sin_dst; |
| 763 | struct route icmproute; |
| 764 | int errornum; |
| 765 | |
| 766 | sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); |
| 767 | memset(&icmproute, 0, sizeof(icmproute)); |
| 768 | errornum = 0; |
| 769 | ia = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum, |
| 770 | &psref_ia); |
| 771 | /* errornum is never used */ |
| 772 | rtcache_free(&icmproute); |
| 773 | /* check to make sure sin is a source address on rcvif */ |
| 774 | if (ia != NULL) { |
| 775 | sin = &ia->ia_addr; |
| 776 | t = sin->sin_addr; |
| 777 | sin = NULL; |
| 778 | ia4_release(ia, &psref_ia); |
| 779 | ia = in_get_ia_on_iface_psref(t, rcvif, &psref_ia); |
| 780 | if (ia != NULL) |
| 781 | sin = &ia->ia_addr; |
| 782 | } |
| 783 | } |
| 784 | |
| 785 | /* |
| 786 | * if it was not addressed to us, but the route doesn't go out |
| 787 | * the source interface, pick an address on the source |
| 788 | * interface. This can happen when routing is asymmetric, or |
| 789 | * when the incoming packet was encapsulated |
| 790 | */ |
| 791 | if (sin == NULL && rcvif) { |
| 792 | KASSERT(ia == NULL); |
| 793 | s = pserialize_read_enter(); |
| 794 | IFADDR_READER_FOREACH(ifa, rcvif) { |
| 795 | if (ifa->ifa_addr->sa_family != AF_INET) |
| 796 | continue; |
| 797 | sin = &(ifatoia(ifa)->ia_addr); |
| 798 | ia = ifatoia(ifa); |
| 799 | ia4_acquire(ia, &psref_ia); |
| 800 | break; |
| 801 | } |
| 802 | pserialize_read_exit(s); |
| 803 | } |
| 804 | |
| 805 | m_put_rcvif_psref(rcvif, &psref); |
| 806 | |
| 807 | /* |
| 808 | * The following happens if the packet was not addressed to us, |
| 809 | * and was received on an interface with no IP address: |
| 810 | * We find the first AF_INET address on the first non-loopback |
| 811 | * interface. |
| 812 | */ |
| 813 | if (sin == NULL) { |
| 814 | KASSERT(ia == NULL); |
| 815 | s = pserialize_read_enter(); |
| 816 | IN_ADDRLIST_READER_FOREACH(ia) { |
| 817 | if (ia->ia_ifp->if_flags & IFF_LOOPBACK) |
| 818 | continue; |
| 819 | sin = &ia->ia_addr; |
| 820 | ia4_acquire(ia, &psref_ia); |
| 821 | break; |
| 822 | } |
| 823 | pserialize_read_exit(s); |
| 824 | } |
| 825 | |
| 826 | /* |
| 827 | * If we still didn't find an address, punt. We could have an |
| 828 | * interface up (and receiving packets) with no address. |
| 829 | */ |
| 830 | if (sin == NULL) { |
| 831 | KASSERT(ia == NULL); |
| 832 | m_freem(m); |
| 833 | goto done; |
| 834 | } |
| 835 | |
| 836 | ip->ip_src = sin->sin_addr; |
| 837 | ip->ip_ttl = MAXTTL; |
| 838 | |
| 839 | if (ia != NULL) |
| 840 | ia4_release(ia, &psref_ia); |
| 841 | |
| 842 | if (optlen > 0) { |
| 843 | u_char *cp; |
| 844 | int opt, cnt; |
| 845 | u_int len; |
| 846 | |
| 847 | /* |
| 848 | * Retrieve any source routing from the incoming packet; |
| 849 | * add on any record-route or timestamp options. |
| 850 | */ |
| 851 | cp = (u_char *) (ip + 1); |
| 852 | if ((opts = ip_srcroute()) == NULL && |
| 853 | (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { |
| 854 | MCLAIM(opts, m->m_owner); |
| 855 | opts->m_len = sizeof(struct in_addr); |
| 856 | *mtod(opts, struct in_addr *) = zeroin_addr; |
| 857 | } |
| 858 | if (opts) { |
| 859 | #ifdef ICMPPRINTFS |
| 860 | if (icmpprintfs) |
| 861 | printf("icmp_reflect optlen %d rt %d => " , |
| 862 | optlen, opts->m_len); |
| 863 | #endif |
| 864 | for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { |
| 865 | opt = cp[IPOPT_OPTVAL]; |
| 866 | if (opt == IPOPT_EOL) |
| 867 | break; |
| 868 | if (opt == IPOPT_NOP) |
| 869 | len = 1; |
| 870 | else { |
| 871 | if (cnt < IPOPT_OLEN + sizeof(*cp)) |
| 872 | break; |
| 873 | len = cp[IPOPT_OLEN]; |
| 874 | if (len < IPOPT_OLEN + sizeof(*cp) || |
| 875 | len > cnt) |
| 876 | break; |
| 877 | } |
| 878 | /* |
| 879 | * Should check for overflow, but it "can't happen" |
| 880 | */ |
| 881 | if (opt == IPOPT_RR || opt == IPOPT_TS || |
| 882 | opt == IPOPT_SECURITY) { |
| 883 | memmove(mtod(opts, char *) + opts->m_len, |
| 884 | cp, len); |
| 885 | opts->m_len += len; |
| 886 | } |
| 887 | } |
| 888 | /* Terminate & pad, if necessary */ |
| 889 | if ((cnt = opts->m_len % 4) != 0) { |
| 890 | for (; cnt < 4; cnt++) { |
| 891 | *(mtod(opts, char *) + opts->m_len) = |
| 892 | IPOPT_EOL; |
| 893 | opts->m_len++; |
| 894 | } |
| 895 | } |
| 896 | #ifdef ICMPPRINTFS |
| 897 | if (icmpprintfs) |
| 898 | printf("%d\n" , opts->m_len); |
| 899 | #endif |
| 900 | } |
| 901 | /* |
| 902 | * Now strip out original options by copying rest of first |
| 903 | * mbuf's data back, and adjust the IP length. |
| 904 | */ |
| 905 | ip->ip_len = htons(ntohs(ip->ip_len) - optlen); |
| 906 | ip->ip_hl = sizeof(struct ip) >> 2; |
| 907 | m->m_len -= optlen; |
| 908 | if (m->m_flags & M_PKTHDR) |
| 909 | m->m_pkthdr.len -= optlen; |
| 910 | optlen += sizeof(struct ip); |
| 911 | memmove(ip + 1, (char *)ip + optlen, |
| 912 | (unsigned)(m->m_len - sizeof(struct ip))); |
| 913 | } |
| 914 | m_tag_delete_nonpersistent(m); |
| 915 | m->m_flags &= ~(M_BCAST|M_MCAST); |
| 916 | |
| 917 | /* |
| 918 | * Clear any in-bound checksum flags for this packet. |
| 919 | */ |
| 920 | if (m->m_flags & M_PKTHDR) |
| 921 | m->m_pkthdr.csum_flags = 0; |
| 922 | |
| 923 | icmp_send(m, opts); |
| 924 | done: |
| 925 | curlwp_bindx(bound); |
| 926 | if (opts) |
| 927 | (void)m_free(opts); |
| 928 | } |
| 929 | |
| 930 | /* |
| 931 | * Send an icmp packet back to the ip level, |
| 932 | * after supplying a checksum. |
| 933 | */ |
| 934 | void |
| 935 | icmp_send(struct mbuf *m, struct mbuf *opts) |
| 936 | { |
| 937 | struct ip *ip = mtod(m, struct ip *); |
| 938 | int hlen; |
| 939 | struct icmp *icp; |
| 940 | |
| 941 | hlen = ip->ip_hl << 2; |
| 942 | m->m_data += hlen; |
| 943 | m->m_len -= hlen; |
| 944 | icp = mtod(m, struct icmp *); |
| 945 | icp->icmp_cksum = 0; |
| 946 | icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); |
| 947 | m->m_data -= hlen; |
| 948 | m->m_len += hlen; |
| 949 | #ifdef ICMPPRINTFS |
| 950 | if (icmpprintfs) { |
| 951 | char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; |
| 952 | printf("icmp_send to destination `%s' from `%s'\n" , |
| 953 | IN_PRINT(dbuf, &ip->ip_dst), IN_PRINT(sbuf, &ip->ip_src)); |
| 954 | } |
| 955 | #endif |
| 956 | (void)ip_output(m, opts, NULL, 0, NULL, NULL); |
| 957 | } |
| 958 | |
| 959 | n_time |
| 960 | iptime(void) |
| 961 | { |
| 962 | struct timeval atv; |
| 963 | u_long t; |
| 964 | |
| 965 | microtime(&atv); |
| 966 | t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; |
| 967 | return (htonl(t)); |
| 968 | } |
| 969 | |
| 970 | /* |
| 971 | * sysctl helper routine for net.inet.icmp.returndatabytes. ensures |
| 972 | * that the new value is in the correct range. |
| 973 | */ |
| 974 | static int |
| 975 | sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) |
| 976 | { |
| 977 | int error, t; |
| 978 | struct sysctlnode node; |
| 979 | |
| 980 | node = *rnode; |
| 981 | node.sysctl_data = &t; |
| 982 | t = icmpreturndatabytes; |
| 983 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
| 984 | if (error || newp == NULL) |
| 985 | return (error); |
| 986 | |
| 987 | if (t < 8 || t > 512) |
| 988 | return (EINVAL); |
| 989 | icmpreturndatabytes = t; |
| 990 | |
| 991 | return (0); |
| 992 | } |
| 993 | |
| 994 | /* |
| 995 | * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that |
| 996 | * the given value is not less than zero and then resets the timeout |
| 997 | * queue. |
| 998 | */ |
| 999 | static int |
| 1000 | sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) |
| 1001 | { |
| 1002 | int error, tmp; |
| 1003 | struct sysctlnode node; |
| 1004 | |
| 1005 | node = *rnode; |
| 1006 | node.sysctl_data = &tmp; |
| 1007 | tmp = icmp_redirtimeout; |
| 1008 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
| 1009 | if (error || newp == NULL) |
| 1010 | return (error); |
| 1011 | if (tmp < 0) |
| 1012 | return (EINVAL); |
| 1013 | icmp_redirtimeout = tmp; |
| 1014 | |
| 1015 | /* |
| 1016 | * was it a *defined* side-effect that anyone even *reading* |
| 1017 | * this value causes these things to happen? |
| 1018 | */ |
| 1019 | if (icmp_redirect_timeout_q != NULL) { |
| 1020 | if (icmp_redirtimeout == 0) { |
| 1021 | rt_timer_queue_destroy(icmp_redirect_timeout_q); |
| 1022 | icmp_redirect_timeout_q = NULL; |
| 1023 | } else { |
| 1024 | rt_timer_queue_change(icmp_redirect_timeout_q, |
| 1025 | icmp_redirtimeout); |
| 1026 | } |
| 1027 | } else if (icmp_redirtimeout > 0) { |
| 1028 | icmp_redirect_timeout_q = |
| 1029 | rt_timer_queue_create(icmp_redirtimeout); |
| 1030 | } |
| 1031 | |
| 1032 | return (0); |
| 1033 | } |
| 1034 | |
| 1035 | static int |
| 1036 | sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) |
| 1037 | { |
| 1038 | |
| 1039 | return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); |
| 1040 | } |
| 1041 | |
| 1042 | static void |
| 1043 | sysctl_netinet_icmp_setup(struct sysctllog **clog) |
| 1044 | { |
| 1045 | |
| 1046 | sysctl_createv(clog, 0, NULL, NULL, |
| 1047 | CTLFLAG_PERMANENT, |
| 1048 | CTLTYPE_NODE, "inet" , NULL, |
| 1049 | NULL, 0, NULL, 0, |
| 1050 | CTL_NET, PF_INET, CTL_EOL); |
| 1051 | sysctl_createv(clog, 0, NULL, NULL, |
| 1052 | CTLFLAG_PERMANENT, |
| 1053 | CTLTYPE_NODE, "icmp" , |
| 1054 | SYSCTL_DESCR("ICMPv4 related settings" ), |
| 1055 | NULL, 0, NULL, 0, |
| 1056 | CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); |
| 1057 | |
| 1058 | sysctl_createv(clog, 0, NULL, NULL, |
| 1059 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 1060 | CTLTYPE_INT, "maskrepl" , |
| 1061 | SYSCTL_DESCR("Respond to ICMP_MASKREQ messages" ), |
| 1062 | NULL, 0, &icmpmaskrepl, 0, |
| 1063 | CTL_NET, PF_INET, IPPROTO_ICMP, |
| 1064 | ICMPCTL_MASKREPL, CTL_EOL); |
| 1065 | sysctl_createv(clog, 0, NULL, NULL, |
| 1066 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 1067 | CTLTYPE_INT, "returndatabytes" , |
| 1068 | SYSCTL_DESCR("Number of bytes to return in an ICMP " |
| 1069 | "error message" ), |
| 1070 | sysctl_net_inet_icmp_returndatabytes, 0, |
| 1071 | &icmpreturndatabytes, 0, |
| 1072 | CTL_NET, PF_INET, IPPROTO_ICMP, |
| 1073 | ICMPCTL_RETURNDATABYTES, CTL_EOL); |
| 1074 | sysctl_createv(clog, 0, NULL, NULL, |
| 1075 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 1076 | CTLTYPE_INT, "errppslimit" , |
| 1077 | SYSCTL_DESCR("Maximum number of outgoing ICMP error " |
| 1078 | "messages per second" ), |
| 1079 | NULL, 0, &icmperrppslim, 0, |
| 1080 | CTL_NET, PF_INET, IPPROTO_ICMP, |
| 1081 | ICMPCTL_ERRPPSLIMIT, CTL_EOL); |
| 1082 | sysctl_createv(clog, 0, NULL, NULL, |
| 1083 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 1084 | CTLTYPE_INT, "rediraccept" , |
| 1085 | SYSCTL_DESCR("Accept ICMP_REDIRECT messages" ), |
| 1086 | NULL, 0, &icmp_rediraccept, 0, |
| 1087 | CTL_NET, PF_INET, IPPROTO_ICMP, |
| 1088 | ICMPCTL_REDIRACCEPT, CTL_EOL); |
| 1089 | sysctl_createv(clog, 0, NULL, NULL, |
| 1090 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 1091 | CTLTYPE_INT, "redirtimeout" , |
| 1092 | SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " |
| 1093 | "routes" ), |
| 1094 | sysctl_net_inet_icmp_redirtimeout, 0, |
| 1095 | &icmp_redirtimeout, 0, |
| 1096 | CTL_NET, PF_INET, IPPROTO_ICMP, |
| 1097 | ICMPCTL_REDIRTIMEOUT, CTL_EOL); |
| 1098 | sysctl_createv(clog, 0, NULL, NULL, |
| 1099 | CTLFLAG_PERMANENT, |
| 1100 | CTLTYPE_STRUCT, "stats" , |
| 1101 | SYSCTL_DESCR("ICMP statistics" ), |
| 1102 | sysctl_net_inet_icmp_stats, 0, NULL, 0, |
| 1103 | CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, |
| 1104 | CTL_EOL); |
| 1105 | sysctl_createv(clog, 0, NULL, NULL, |
| 1106 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
| 1107 | CTLTYPE_INT, "bmcastecho" , |
| 1108 | SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " |
| 1109 | "message to the broadcast or multicast" ), |
| 1110 | NULL, 0, &icmpbmcastecho, 0, |
| 1111 | CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, |
| 1112 | CTL_EOL); |
| 1113 | } |
| 1114 | |
| 1115 | void |
| 1116 | icmp_statinc(u_int stat) |
| 1117 | { |
| 1118 | |
| 1119 | KASSERT(stat < ICMP_NSTATS); |
| 1120 | ICMP_STATINC(stat); |
| 1121 | } |
| 1122 | |
| 1123 | /* Table of common MTUs: */ |
| 1124 | |
| 1125 | static const u_int mtu_table[] = { |
| 1126 | 65535, 65280, 32000, 17914, 9180, 8166, |
| 1127 | 4352, 2002, 1492, 1006, 508, 296, 68, 0 |
| 1128 | }; |
| 1129 | |
| 1130 | void |
| 1131 | icmp_mtudisc(struct icmp *icp, struct in_addr faddr) |
| 1132 | { |
| 1133 | struct icmp_mtudisc_callback *mc; |
| 1134 | struct sockaddr *dst = sintosa(&icmpsrc); |
| 1135 | struct rtentry *rt; |
| 1136 | u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ |
| 1137 | int error; |
| 1138 | |
| 1139 | rt = rtalloc1(dst, 1); |
| 1140 | if (rt == NULL) |
| 1141 | return; |
| 1142 | |
| 1143 | /* If we didn't get a host route, allocate one */ |
| 1144 | |
| 1145 | if ((rt->rt_flags & RTF_HOST) == 0) { |
| 1146 | struct rtentry *nrt; |
| 1147 | |
| 1148 | error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL, |
| 1149 | RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); |
| 1150 | if (error) { |
| 1151 | rtfree(rt); |
| 1152 | return; |
| 1153 | } |
| 1154 | nrt->rt_rmx = rt->rt_rmx; |
| 1155 | rtfree(rt); |
| 1156 | rt = nrt; |
| 1157 | } |
| 1158 | error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); |
| 1159 | if (error) { |
| 1160 | rtfree(rt); |
| 1161 | return; |
| 1162 | } |
| 1163 | |
| 1164 | if (mtu == 0) { |
| 1165 | int i = 0; |
| 1166 | |
| 1167 | mtu = ntohs(icp->icmp_ip.ip_len); |
| 1168 | /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ |
| 1169 | if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) |
| 1170 | mtu -= (icp->icmp_ip.ip_hl << 2); |
| 1171 | |
| 1172 | /* If we still can't guess a value, try the route */ |
| 1173 | |
| 1174 | if (mtu == 0) { |
| 1175 | mtu = rt->rt_rmx.rmx_mtu; |
| 1176 | |
| 1177 | /* If no route mtu, default to the interface mtu */ |
| 1178 | |
| 1179 | if (mtu == 0) |
| 1180 | mtu = rt->rt_ifp->if_mtu; |
| 1181 | } |
| 1182 | |
| 1183 | for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) |
| 1184 | if (mtu > mtu_table[i]) { |
| 1185 | mtu = mtu_table[i]; |
| 1186 | break; |
| 1187 | } |
| 1188 | } |
| 1189 | |
| 1190 | /* |
| 1191 | * XXX: RTV_MTU is overloaded, since the admin can set it |
| 1192 | * to turn off PMTU for a route, and the kernel can |
| 1193 | * set it to indicate a serious problem with PMTU |
| 1194 | * on a route. We should be using a separate flag |
| 1195 | * for the kernel to indicate this. |
| 1196 | */ |
| 1197 | |
| 1198 | if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { |
| 1199 | if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) |
| 1200 | rt->rt_rmx.rmx_locks |= RTV_MTU; |
| 1201 | else if (rt->rt_rmx.rmx_mtu > mtu || |
| 1202 | rt->rt_rmx.rmx_mtu == 0) { |
| 1203 | ICMP_STATINC(ICMP_STAT_PMTUCHG); |
| 1204 | rt->rt_rmx.rmx_mtu = mtu; |
| 1205 | } |
| 1206 | } |
| 1207 | |
| 1208 | if (rt) |
| 1209 | rtfree(rt); |
| 1210 | |
| 1211 | /* |
| 1212 | * Notify protocols that the MTU for this destination |
| 1213 | * has changed. |
| 1214 | */ |
| 1215 | for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; |
| 1216 | mc = LIST_NEXT(mc, mc_list)) |
| 1217 | (*mc->mc_func)(faddr); |
| 1218 | } |
| 1219 | |
| 1220 | /* |
| 1221 | * Return the next larger or smaller MTU plateau (table from RFC 1191) |
| 1222 | * given current value MTU. If DIR is less than zero, a larger plateau |
| 1223 | * is returned; otherwise, a smaller value is returned. |
| 1224 | */ |
| 1225 | u_int |
| 1226 | ip_next_mtu(u_int mtu, int dir) /* XXX */ |
| 1227 | { |
| 1228 | int i; |
| 1229 | |
| 1230 | for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { |
| 1231 | if (mtu >= mtu_table[i]) |
| 1232 | break; |
| 1233 | } |
| 1234 | |
| 1235 | if (dir < 0) { |
| 1236 | if (i == 0) { |
| 1237 | return 0; |
| 1238 | } else { |
| 1239 | return mtu_table[i - 1]; |
| 1240 | } |
| 1241 | } else { |
| 1242 | if (mtu_table[i] == 0) { |
| 1243 | return 0; |
| 1244 | } else if (mtu > mtu_table[i]) { |
| 1245 | return mtu_table[i]; |
| 1246 | } else { |
| 1247 | return mtu_table[i + 1]; |
| 1248 | } |
| 1249 | } |
| 1250 | } |
| 1251 | |
| 1252 | static void |
| 1253 | icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) |
| 1254 | { |
| 1255 | |
| 1256 | KASSERT(rt != NULL); |
| 1257 | rt_assert_referenced(rt); |
| 1258 | |
| 1259 | if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == |
| 1260 | (RTF_DYNAMIC | RTF_HOST)) { |
| 1261 | rtrequest(RTM_DELETE, rt_getkey(rt), |
| 1262 | rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); |
| 1263 | } else { |
| 1264 | if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { |
| 1265 | rt->rt_rmx.rmx_mtu = 0; |
| 1266 | } |
| 1267 | } |
| 1268 | } |
| 1269 | |
| 1270 | static void |
| 1271 | icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) |
| 1272 | { |
| 1273 | |
| 1274 | KASSERT(rt != NULL); |
| 1275 | rt_assert_referenced(rt); |
| 1276 | |
| 1277 | if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == |
| 1278 | (RTF_DYNAMIC | RTF_HOST)) { |
| 1279 | rtrequest(RTM_DELETE, rt_getkey(rt), |
| 1280 | rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); |
| 1281 | } |
| 1282 | } |
| 1283 | |
| 1284 | /* |
| 1285 | * Perform rate limit check. |
| 1286 | * Returns 0 if it is okay to send the icmp packet. |
| 1287 | * Returns 1 if the router SHOULD NOT send this icmp packet due to rate |
| 1288 | * limitation. |
| 1289 | * |
| 1290 | * XXX per-destination/type check necessary? |
| 1291 | */ |
| 1292 | int |
| 1293 | icmp_ratelimit(const struct in_addr *dst, const int type, |
| 1294 | const int code) |
| 1295 | { |
| 1296 | |
| 1297 | /* PPS limit */ |
| 1298 | if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, |
| 1299 | icmperrppslim)) { |
| 1300 | /* The packet is subject to rate limit */ |
| 1301 | return 1; |
| 1302 | } |
| 1303 | |
| 1304 | /* okay to send */ |
| 1305 | return 0; |
| 1306 | } |
| 1307 | |