1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1993 5 * The Regents of the University of California. 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 University 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 REGENTS 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 REGENTS 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 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 #include "opt_sctp.h" 38 #ifndef INET 39 #error "IPDIVERT requires INET" 40 #endif 41 42 #include <sys/param.h> 43 #include <sys/eventhandler.h> 44 #include <sys/kernel.h> 45 #include <sys/lock.h> 46 #include <sys/malloc.h> 47 #include <sys/mbuf.h> 48 #include <sys/module.h> 49 #include <sys/kernel.h> 50 #include <sys/priv.h> 51 #include <sys/proc.h> 52 #include <sys/protosw.h> 53 #include <sys/socket.h> 54 #include <sys/socketvar.h> 55 #include <sys/sysctl.h> 56 #include <net/vnet.h> 57 58 #include <net/if.h> 59 #include <net/if_var.h> 60 #include <net/netisr.h> 61 62 #include <netinet/in.h> 63 #include <netinet/in_pcb.h> 64 #include <netinet/in_systm.h> 65 #include <netinet/in_var.h> 66 #include <netinet/ip.h> 67 #include <netinet/ip_var.h> 68 #ifdef INET6 69 #include <netinet/ip6.h> 70 #include <netinet6/ip6_var.h> 71 #endif 72 #if defined(SCTP) || defined(SCTP_SUPPORT) 73 #include <netinet/sctp_crc32.h> 74 #endif 75 76 #include <security/mac/mac_framework.h> 77 /* 78 * Divert sockets 79 */ 80 81 /* 82 * Allocate enough space to hold a full IP packet 83 */ 84 #define DIVSNDQ (65536 + 100) 85 #define DIVRCVQ (65536 + 100) 86 87 /* 88 * Divert sockets work in conjunction with ipfw or other packet filters, 89 * see the divert(4) manpage for features. 90 * Packets are selected by the packet filter and tagged with an 91 * MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by 92 * the packet filter) and information on the matching filter rule for 93 * subsequent reinjection. The divert_port is used to put the packet 94 * on the corresponding divert socket, while the rule number is passed 95 * up (at least partially) as the sin_port in the struct sockaddr. 96 * 97 * Packets written to the divert socket carry in sin_addr a 98 * destination address, and in sin_port the number of the filter rule 99 * after which to continue processing. 100 * If the destination address is INADDR_ANY, the packet is treated as 101 * as outgoing and sent to ip_output(); otherwise it is treated as 102 * incoming and sent to ip_input(). 103 * Further, sin_zero carries some information on the interface, 104 * which can be used in the reinject -- see comments in the code. 105 * 106 * On reinjection, processing in ip_input() and ip_output() 107 * will be exactly the same as for the original packet, except that 108 * packet filter processing will start at the rule number after the one 109 * written in the sin_port (ipfw does not allow a rule #0, so sin_port=0 110 * will apply the entire ruleset to the packet). 111 */ 112 113 /* Internal variables. */ 114 VNET_DEFINE_STATIC(struct inpcbhead, divcb); 115 VNET_DEFINE_STATIC(struct inpcbinfo, divcbinfo); 116 117 #define V_divcb VNET(divcb) 118 #define V_divcbinfo VNET(divcbinfo) 119 120 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 121 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 122 123 static eventhandler_tag ip_divert_event_tag; 124 125 static int div_output_inbound(int fmaily, struct socket *so, struct mbuf *m, 126 struct sockaddr_in *sin); 127 static int div_output_outbound(int family, struct socket *so, struct mbuf *m); 128 129 /* 130 * Initialize divert connection block queue. 131 */ 132 static void 133 div_zone_change(void *tag) 134 { 135 136 uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets); 137 } 138 139 static int 140 div_inpcb_init(void *mem, int size, int flags) 141 { 142 struct inpcb *inp = mem; 143 144 INP_LOCK_INIT(inp, "inp", "divinp"); 145 return (0); 146 } 147 148 static void 149 div_init(void) 150 { 151 152 /* 153 * XXX We don't use the hash list for divert IP, but it's easier to 154 * allocate one-entry hash lists than it is to check all over the 155 * place for hashbase == NULL. 156 */ 157 in_pcbinfo_init(&V_divcbinfo, "div", &V_divcb, 1, 1, "divcb", 158 div_inpcb_init, IPI_HASHFIELDS_NONE); 159 } 160 161 static void 162 div_destroy(void *unused __unused) 163 { 164 165 in_pcbinfo_destroy(&V_divcbinfo); 166 } 167 VNET_SYSUNINIT(divert, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, 168 div_destroy, NULL); 169 170 /* 171 * IPPROTO_DIVERT is not in the real IP protocol number space; this 172 * function should never be called. Just in case, drop any packets. 173 */ 174 static int 175 div_input(struct mbuf **mp, int *offp, int proto) 176 { 177 struct mbuf *m = *mp; 178 179 KMOD_IPSTAT_INC(ips_noproto); 180 m_freem(m); 181 return (IPPROTO_DONE); 182 } 183 184 /* 185 * Divert a packet by passing it up to the divert socket at port 'port'. 186 * 187 * Setup generic address and protocol structures for div_input routine, 188 * then pass them along with mbuf chain. 189 */ 190 static void 191 divert_packet(struct mbuf *m, bool incoming) 192 { 193 struct ip *ip; 194 struct inpcb *inp; 195 struct socket *sa; 196 u_int16_t nport; 197 struct sockaddr_in divsrc; 198 struct m_tag *mtag; 199 200 NET_EPOCH_ASSERT(); 201 202 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 203 if (mtag == NULL) { 204 m_freem(m); 205 return; 206 } 207 /* Assure header */ 208 if (m->m_len < sizeof(struct ip) && 209 (m = m_pullup(m, sizeof(struct ip))) == NULL) 210 return; 211 ip = mtod(m, struct ip *); 212 213 /* Delayed checksums are currently not compatible with divert. */ 214 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 215 m = mb_unmapped_to_ext(m); 216 if (m == NULL) 217 return; 218 in_delayed_cksum(m); 219 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 220 } 221 #if defined(SCTP) || defined(SCTP_SUPPORT) 222 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 223 m = mb_unmapped_to_ext(m); 224 if (m == NULL) 225 return; 226 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 227 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 228 } 229 #endif 230 bzero(&divsrc, sizeof(divsrc)); 231 divsrc.sin_len = sizeof(divsrc); 232 divsrc.sin_family = AF_INET; 233 /* record matching rule, in host format */ 234 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 235 /* 236 * Record receive interface address, if any. 237 * But only for incoming packets. 238 */ 239 if (incoming) { 240 struct ifaddr *ifa; 241 struct ifnet *ifp; 242 243 /* Sanity check */ 244 M_ASSERTPKTHDR(m); 245 246 /* Find IP address for receive interface */ 247 ifp = m->m_pkthdr.rcvif; 248 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 249 if (ifa->ifa_addr->sa_family != AF_INET) 250 continue; 251 divsrc.sin_addr = 252 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 253 break; 254 } 255 } 256 /* 257 * Record the incoming interface name whenever we have one. 258 */ 259 if (m->m_pkthdr.rcvif) { 260 /* 261 * Hide the actual interface name in there in the 262 * sin_zero array. XXX This needs to be moved to a 263 * different sockaddr type for divert, e.g. 264 * sockaddr_div with multiple fields like 265 * sockaddr_dl. Presently we have only 7 bytes 266 * but that will do for now as most interfaces 267 * are 4 or less + 2 or less bytes for unit. 268 * There is probably a faster way of doing this, 269 * possibly taking it from the sockaddr_dl on the iface. 270 * This solves the problem of a P2P link and a LAN interface 271 * having the same address, which can result in the wrong 272 * interface being assigned to the packet when fed back 273 * into the divert socket. Theoretically if the daemon saves 274 * and re-uses the sockaddr_in as suggested in the man pages, 275 * this iface name will come along for the ride. 276 * (see div_output for the other half of this.) 277 */ 278 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 279 sizeof(divsrc.sin_zero)); 280 } 281 282 /* Put packet on socket queue, if any */ 283 sa = NULL; 284 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 285 CK_LIST_FOREACH(inp, &V_divcb, inp_list) { 286 /* XXX why does only one socket match? */ 287 if (inp->inp_lport == nport) { 288 INP_RLOCK(inp); 289 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 290 INP_RUNLOCK(inp); 291 continue; 292 } 293 sa = inp->inp_socket; 294 SOCKBUF_LOCK(&sa->so_rcv); 295 if (sbappendaddr_locked(&sa->so_rcv, 296 (struct sockaddr *)&divsrc, m, 297 (struct mbuf *)0) == 0) { 298 SOCKBUF_UNLOCK(&sa->so_rcv); 299 sa = NULL; /* force mbuf reclaim below */ 300 } else 301 sorwakeup_locked(sa); 302 INP_RUNLOCK(inp); 303 break; 304 } 305 } 306 if (sa == NULL) { 307 m_freem(m); 308 KMOD_IPSTAT_INC(ips_noproto); 309 KMOD_IPSTAT_DEC(ips_delivered); 310 } 311 } 312 313 /* 314 * Deliver packet back into the IP processing machinery. 315 * 316 * If no address specified, or address is 0.0.0.0, send to ip_output(); 317 * otherwise, send to ip_input() and mark as having been received on 318 * the interface with that address. 319 */ 320 static int 321 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 322 struct mbuf *control) 323 { 324 struct epoch_tracker et; 325 const struct ip *ip; 326 struct m_tag *mtag; 327 struct ipfw_rule_ref *dt; 328 int error, family; 329 330 /* 331 * An mbuf may hasn't come from userland, but we pretend 332 * that it has. 333 */ 334 m->m_pkthdr.rcvif = NULL; 335 m->m_nextpkt = NULL; 336 M_SETFIB(m, so->so_fibnum); 337 338 if (control) 339 m_freem(control); /* XXX */ 340 341 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 342 if (mtag == NULL) { 343 /* this should be normal */ 344 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 345 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 346 if (mtag == NULL) { 347 m_freem(m); 348 return (ENOBUFS); 349 } 350 m_tag_prepend(m, mtag); 351 } 352 dt = (struct ipfw_rule_ref *)(mtag+1); 353 354 /* Loopback avoidance and state recovery */ 355 if (sin) { 356 int i; 357 358 /* set the starting point. We provide a non-zero slot, 359 * but a non_matching chain_id to skip that info and use 360 * the rulenum/rule_id. 361 */ 362 dt->slot = 1; /* dummy, chain_id is invalid */ 363 dt->chain_id = 0; 364 dt->rulenum = sin->sin_port+1; /* host format ? */ 365 dt->rule_id = 0; 366 /* XXX: broken for IPv6 */ 367 /* 368 * Find receive interface with the given name, stuffed 369 * (if it exists) in the sin_zero[] field. 370 * The name is user supplied data so don't trust its size 371 * or that it is zero terminated. 372 */ 373 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 374 ; 375 if ( i > 0 && i < sizeof(sin->sin_zero)) 376 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 377 } 378 379 ip = mtod(m, struct ip *); 380 switch (ip->ip_v) { 381 case IPVERSION: 382 family = AF_INET; 383 break; 384 #ifdef INET6 385 case IPV6_VERSION >> 4: 386 family = AF_INET6; 387 break; 388 #endif 389 default: 390 m_freem(m); 391 return (EAFNOSUPPORT); 392 } 393 394 /* Reinject packet into the system as incoming or outgoing */ 395 NET_EPOCH_ENTER(et); 396 if (!sin || sin->sin_addr.s_addr == 0) { 397 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 398 error = div_output_outbound(family, so, m); 399 } else { 400 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 401 error = div_output_inbound(family, so, m, sin); 402 } 403 NET_EPOCH_EXIT(et); 404 405 if (error != 0) 406 m_freem(m); 407 408 return (error); 409 } 410 411 /* 412 * Sends mbuf @m to the wire via ip[6]_output(). 413 * 414 * Returns 0 on success, @m is consumed. 415 * On failure, returns error code. It is caller responsibility to free @m. 416 */ 417 static int 418 div_output_outbound(int family, struct socket *so, struct mbuf *m) 419 { 420 struct ip *const ip = mtod(m, struct ip *); 421 struct mbuf *options; 422 struct inpcb *inp; 423 int error; 424 425 inp = sotoinpcb(so); 426 INP_RLOCK(inp); 427 switch (family) { 428 case AF_INET: 429 /* 430 * Don't allow both user specified and setsockopt 431 * options, and don't allow packet length sizes that 432 * will crash. 433 */ 434 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 435 inp->inp_options != NULL) || 436 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 437 INP_RUNLOCK(inp); 438 return (EINVAL); 439 } 440 break; 441 #ifdef INET6 442 case AF_INET6: 443 { 444 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 445 446 /* Don't allow packet length sizes that will crash */ 447 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 448 INP_RUNLOCK(inp); 449 return (EINVAL); 450 } 451 break; 452 } 453 #endif 454 } 455 456 /* Send packet to output processing */ 457 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 458 459 #ifdef MAC 460 mac_inpcb_create_mbuf(inp, m); 461 #endif 462 /* 463 * Get ready to inject the packet into ip_output(). 464 * Just in case socket options were specified on the 465 * divert socket, we duplicate them. This is done 466 * to avoid having to hold the PCB locks over the call 467 * to ip_output(), as doing this results in a number of 468 * lock ordering complexities. 469 * 470 * Note that we set the multicast options argument for 471 * ip_output() to NULL since it should be invariant that 472 * they are not present. 473 */ 474 KASSERT(inp->inp_moptions == NULL, 475 ("multicast options set on a divert socket")); 476 /* 477 * XXXCSJP: It is unclear to me whether or not it makes 478 * sense for divert sockets to have options. However, 479 * for now we will duplicate them with the INP locks 480 * held so we can use them in ip_output() without 481 * requring a reference to the pcb. 482 */ 483 options = NULL; 484 if (inp->inp_options != NULL) { 485 options = m_dup(inp->inp_options, M_NOWAIT); 486 if (options == NULL) { 487 INP_RUNLOCK(inp); 488 return (ENOBUFS); 489 } 490 } 491 INP_RUNLOCK(inp); 492 493 error = 0; 494 switch (family) { 495 case AF_INET: 496 error = ip_output(m, options, NULL, 497 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 498 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 499 break; 500 #ifdef INET6 501 case AF_INET6: 502 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 503 break; 504 #endif 505 } 506 if (options != NULL) 507 m_freem(options); 508 509 return (error); 510 } 511 512 /* 513 * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue. 514 * 515 * Returns 0 on success, @m is consumed. 516 * Returns error code on failure. It is caller responsibility to free @m. 517 */ 518 static int 519 div_output_inbound(int family, struct socket *so, struct mbuf *m, 520 struct sockaddr_in *sin) 521 { 522 const struct ip *ip; 523 struct ifaddr *ifa; 524 525 if (m->m_pkthdr.rcvif == NULL) { 526 /* 527 * No luck with the name, check by IP address. 528 * Clear the port and the ifname to make sure 529 * there are no distractions for ifa_ifwithaddr. 530 */ 531 532 /* XXX: broken for IPv6 */ 533 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 534 sin->sin_port = 0; 535 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 536 if (ifa == NULL) 537 return (EADDRNOTAVAIL); 538 m->m_pkthdr.rcvif = ifa->ifa_ifp; 539 } 540 #ifdef MAC 541 mac_socket_create_mbuf(so, m); 542 #endif 543 /* Send packet to input processing via netisr */ 544 switch (family) { 545 case AF_INET: 546 ip = mtod(m, struct ip *); 547 /* 548 * Restore M_BCAST flag when destination address is 549 * broadcast. It is expected by ip_tryforward(). 550 */ 551 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) 552 m->m_flags |= M_MCAST; 553 else if (in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) 554 m->m_flags |= M_BCAST; 555 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 556 break; 557 #ifdef INET6 558 case AF_INET6: 559 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 560 break; 561 #endif 562 default: 563 return (EINVAL); 564 } 565 566 return (0); 567 } 568 569 static int 570 div_attach(struct socket *so, int proto, struct thread *td) 571 { 572 struct inpcb *inp; 573 int error; 574 575 inp = sotoinpcb(so); 576 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 577 if (td != NULL) { 578 error = priv_check(td, PRIV_NETINET_DIVERT); 579 if (error) 580 return (error); 581 } 582 error = soreserve(so, div_sendspace, div_recvspace); 583 if (error) 584 return error; 585 INP_INFO_WLOCK(&V_divcbinfo); 586 error = in_pcballoc(so, &V_divcbinfo); 587 if (error) { 588 INP_INFO_WUNLOCK(&V_divcbinfo); 589 return error; 590 } 591 inp = (struct inpcb *)so->so_pcb; 592 INP_INFO_WUNLOCK(&V_divcbinfo); 593 inp->inp_ip_p = proto; 594 inp->inp_vflag |= INP_IPV4; 595 inp->inp_flags |= INP_HDRINCL; 596 INP_WUNLOCK(inp); 597 return 0; 598 } 599 600 static void 601 div_detach(struct socket *so) 602 { 603 struct inpcb *inp; 604 605 inp = sotoinpcb(so); 606 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 607 INP_INFO_WLOCK(&V_divcbinfo); 608 INP_WLOCK(inp); 609 in_pcbdetach(inp); 610 in_pcbfree(inp); 611 INP_INFO_WUNLOCK(&V_divcbinfo); 612 } 613 614 static int 615 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 616 { 617 struct inpcb *inp; 618 int error; 619 620 inp = sotoinpcb(so); 621 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 622 /* in_pcbbind assumes that nam is a sockaddr_in 623 * and in_pcbbind requires a valid address. Since divert 624 * sockets don't we need to make sure the address is 625 * filled in properly. 626 * XXX -- divert should not be abusing in_pcbind 627 * and should probably have its own family. 628 */ 629 if (nam->sa_family != AF_INET) 630 return EAFNOSUPPORT; 631 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 632 INP_INFO_WLOCK(&V_divcbinfo); 633 INP_WLOCK(inp); 634 INP_HASH_WLOCK(&V_divcbinfo); 635 error = in_pcbbind(inp, nam, td->td_ucred); 636 INP_HASH_WUNLOCK(&V_divcbinfo); 637 INP_WUNLOCK(inp); 638 INP_INFO_WUNLOCK(&V_divcbinfo); 639 return error; 640 } 641 642 static int 643 div_shutdown(struct socket *so) 644 { 645 struct inpcb *inp; 646 647 inp = sotoinpcb(so); 648 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 649 INP_WLOCK(inp); 650 socantsendmore(so); 651 INP_WUNLOCK(inp); 652 return 0; 653 } 654 655 static int 656 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 657 struct mbuf *control, struct thread *td) 658 { 659 660 /* Packet must have a header (but that's about it) */ 661 if (m->m_len < sizeof (struct ip) && 662 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 663 KMOD_IPSTAT_INC(ips_toosmall); 664 m_freem(m); 665 return EINVAL; 666 } 667 668 /* Send packet */ 669 return div_output(so, m, (struct sockaddr_in *)nam, control); 670 } 671 672 static void 673 div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 674 { 675 struct in_addr faddr; 676 677 faddr = ((struct sockaddr_in *)sa)->sin_addr; 678 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 679 return; 680 if (PRC_IS_REDIRECT(cmd)) 681 return; 682 } 683 684 static int 685 div_pcblist(SYSCTL_HANDLER_ARGS) 686 { 687 struct xinpgen xig; 688 struct epoch_tracker et; 689 struct inpcb *inp; 690 int error; 691 692 if (req->newptr != 0) 693 return EPERM; 694 695 if (req->oldptr == 0) { 696 int n; 697 698 n = V_divcbinfo.ipi_count; 699 n += imax(n / 8, 10); 700 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 701 return 0; 702 } 703 704 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 705 return (error); 706 707 bzero(&xig, sizeof(xig)); 708 xig.xig_len = sizeof xig; 709 xig.xig_count = V_divcbinfo.ipi_count; 710 xig.xig_gen = V_divcbinfo.ipi_gencnt; 711 xig.xig_sogen = so_gencnt; 712 error = SYSCTL_OUT(req, &xig, sizeof xig); 713 if (error) 714 return error; 715 716 NET_EPOCH_ENTER(et); 717 for (inp = CK_LIST_FIRST(V_divcbinfo.ipi_listhead); 718 inp != NULL; 719 inp = CK_LIST_NEXT(inp, inp_list)) { 720 INP_RLOCK(inp); 721 if (inp->inp_gencnt <= xig.xig_gen) { 722 struct xinpcb xi; 723 724 in_pcbtoxinpcb(inp, &xi); 725 INP_RUNLOCK(inp); 726 error = SYSCTL_OUT(req, &xi, sizeof xi); 727 } else 728 INP_RUNLOCK(inp); 729 } 730 NET_EPOCH_EXIT(et); 731 732 if (!error) { 733 /* 734 * Give the user an updated idea of our state. 735 * If the generation differs from what we told 736 * her before, she knows that something happened 737 * while we were processing this request, and it 738 * might be necessary to retry. 739 */ 740 xig.xig_gen = V_divcbinfo.ipi_gencnt; 741 xig.xig_sogen = so_gencnt; 742 xig.xig_count = V_divcbinfo.ipi_count; 743 error = SYSCTL_OUT(req, &xig, sizeof xig); 744 } 745 746 return (error); 747 } 748 749 #ifdef SYSCTL_NODE 750 static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, 751 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 752 "IPDIVERT"); 753 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, 754 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 755 NULL, 0, div_pcblist, "S,xinpcb", 756 "List of active divert sockets"); 757 #endif 758 759 struct pr_usrreqs div_usrreqs = { 760 .pru_attach = div_attach, 761 .pru_bind = div_bind, 762 .pru_control = in_control, 763 .pru_detach = div_detach, 764 .pru_peeraddr = in_getpeeraddr, 765 .pru_send = div_send, 766 .pru_shutdown = div_shutdown, 767 .pru_sockaddr = in_getsockaddr, 768 .pru_sosetlabel = in_pcbsosetlabel 769 }; 770 771 struct protosw div_protosw = { 772 .pr_type = SOCK_RAW, 773 .pr_protocol = IPPROTO_DIVERT, 774 .pr_flags = PR_ATOMIC|PR_ADDR, 775 .pr_input = div_input, 776 .pr_ctlinput = div_ctlinput, 777 .pr_ctloutput = ip_ctloutput, 778 .pr_init = div_init, 779 .pr_usrreqs = &div_usrreqs 780 }; 781 782 static int 783 div_modevent(module_t mod, int type, void *unused) 784 { 785 int err = 0; 786 787 switch (type) { 788 case MOD_LOAD: 789 /* 790 * Protocol will be initialized by pf_proto_register(). 791 * We don't have to register ip_protox because we are not 792 * a true IP protocol that goes over the wire. 793 */ 794 err = pf_proto_register(PF_INET, &div_protosw); 795 if (err != 0) 796 return (err); 797 ip_divert_ptr = divert_packet; 798 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 799 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 800 break; 801 case MOD_QUIESCE: 802 /* 803 * IPDIVERT may normally not be unloaded because of the 804 * potential race conditions. Tell kldunload we can't be 805 * unloaded unless the unload is forced. 806 */ 807 err = EPERM; 808 break; 809 case MOD_UNLOAD: 810 /* 811 * Forced unload. 812 * 813 * Module ipdivert can only be unloaded if no sockets are 814 * connected. Maybe this can be changed later to forcefully 815 * disconnect any open sockets. 816 * 817 * XXXRW: Note that there is a slight race here, as a new 818 * socket open request could be spinning on the lock and then 819 * we destroy the lock. 820 */ 821 INP_INFO_WLOCK(&V_divcbinfo); 822 if (V_divcbinfo.ipi_count != 0) { 823 err = EBUSY; 824 INP_INFO_WUNLOCK(&V_divcbinfo); 825 break; 826 } 827 ip_divert_ptr = NULL; 828 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 829 INP_INFO_WUNLOCK(&V_divcbinfo); 830 #ifndef VIMAGE 831 div_destroy(NULL); 832 #endif 833 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 834 break; 835 default: 836 err = EOPNOTSUPP; 837 break; 838 } 839 return err; 840 } 841 842 static moduledata_t ipdivertmod = { 843 "ipdivert", 844 div_modevent, 845 0 846 }; 847 848 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 849 MODULE_DEPEND(ipdivert, ipfw, 3, 3, 3); 850 MODULE_VERSION(ipdivert, 1); 851