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 inpcbinfo, divcbinfo); 115 #define V_divcbinfo VNET(divcbinfo) 116 117 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 118 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 119 120 static eventhandler_tag ip_divert_event_tag; 121 122 static int div_output_inbound(int fmaily, struct socket *so, struct mbuf *m, 123 struct sockaddr_in *sin); 124 static int div_output_outbound(int family, struct socket *so, struct mbuf *m); 125 126 /* 127 * Initialize divert connection block queue. 128 */ 129 static void 130 div_zone_change(void *tag) 131 { 132 133 uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets); 134 } 135 136 static int 137 div_inpcb_init(void *mem, int size, int flags) 138 { 139 struct inpcb *inp = mem; 140 141 INP_LOCK_INIT(inp, "inp", "divinp"); 142 return (0); 143 } 144 145 static void 146 div_init(void) 147 { 148 149 /* 150 * XXX We don't use the hash list for divert IP, but it's easier to 151 * allocate one-entry hash lists than it is to check all over the 152 * place for hashbase == NULL. 153 */ 154 in_pcbinfo_init(&V_divcbinfo, "div", 1, 1, "divcb", div_inpcb_init); 155 } 156 157 static void 158 div_destroy(void *unused __unused) 159 { 160 161 in_pcbinfo_destroy(&V_divcbinfo); 162 } 163 VNET_SYSUNINIT(divert, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, 164 div_destroy, NULL); 165 166 /* 167 * IPPROTO_DIVERT is not in the real IP protocol number space; this 168 * function should never be called. Just in case, drop any packets. 169 */ 170 static int 171 div_input(struct mbuf **mp, int *offp, int proto) 172 { 173 struct mbuf *m = *mp; 174 175 KMOD_IPSTAT_INC(ips_noproto); 176 m_freem(m); 177 return (IPPROTO_DONE); 178 } 179 180 static bool 181 div_port_match(const struct inpcb *inp, void *v) 182 { 183 uint16_t nport = *(uint16_t *)v; 184 185 return (inp->inp_lport == nport); 186 } 187 188 /* 189 * Divert a packet by passing it up to the divert socket at port 'port'. 190 * 191 * Setup generic address and protocol structures for div_input routine, 192 * then pass them along with mbuf chain. 193 */ 194 static void 195 divert_packet(struct mbuf *m, bool incoming) 196 { 197 struct ip *ip; 198 struct inpcb *inp; 199 struct socket *sa; 200 u_int16_t nport; 201 struct sockaddr_in divsrc; 202 struct inpcb_iterator inpi = INP_ITERATOR(&V_divcbinfo, 203 INPLOOKUP_RLOCKPCB, div_port_match, &nport); 204 struct m_tag *mtag; 205 206 NET_EPOCH_ASSERT(); 207 208 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 209 if (mtag == NULL) { 210 m_freem(m); 211 return; 212 } 213 /* Assure header */ 214 if (m->m_len < sizeof(struct ip) && 215 (m = m_pullup(m, sizeof(struct ip))) == NULL) 216 return; 217 ip = mtod(m, struct ip *); 218 219 /* Delayed checksums are currently not compatible with divert. */ 220 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 221 in_delayed_cksum(m); 222 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 223 } 224 #if defined(SCTP) || defined(SCTP_SUPPORT) 225 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 226 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 227 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 228 } 229 #endif 230 #ifdef INET6 231 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 232 in6_delayed_cksum(m, m->m_pkthdr.len - 233 sizeof(struct ip6_hdr), sizeof(struct ip6_hdr)); 234 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; 235 } 236 #if defined(SCTP) || defined(SCTP_SUPPORT) 237 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { 238 sctp_delayed_cksum(m, sizeof(struct ip6_hdr)); 239 m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; 240 } 241 #endif 242 #endif /* INET6 */ 243 bzero(&divsrc, sizeof(divsrc)); 244 divsrc.sin_len = sizeof(divsrc); 245 divsrc.sin_family = AF_INET; 246 /* record matching rule, in host format */ 247 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 248 /* 249 * Record receive interface address, if any. 250 * But only for incoming packets. 251 */ 252 if (incoming) { 253 struct ifaddr *ifa; 254 struct ifnet *ifp; 255 256 /* Sanity check */ 257 M_ASSERTPKTHDR(m); 258 259 /* Find IP address for receive interface */ 260 ifp = m->m_pkthdr.rcvif; 261 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 262 if (ifa->ifa_addr->sa_family != AF_INET) 263 continue; 264 divsrc.sin_addr = 265 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 266 break; 267 } 268 } 269 /* 270 * Record the incoming interface name whenever we have one. 271 */ 272 if (m->m_pkthdr.rcvif) { 273 /* 274 * Hide the actual interface name in there in the 275 * sin_zero array. XXX This needs to be moved to a 276 * different sockaddr type for divert, e.g. 277 * sockaddr_div with multiple fields like 278 * sockaddr_dl. Presently we have only 7 bytes 279 * but that will do for now as most interfaces 280 * are 4 or less + 2 or less bytes for unit. 281 * There is probably a faster way of doing this, 282 * possibly taking it from the sockaddr_dl on the iface. 283 * This solves the problem of a P2P link and a LAN interface 284 * having the same address, which can result in the wrong 285 * interface being assigned to the packet when fed back 286 * into the divert socket. Theoretically if the daemon saves 287 * and re-uses the sockaddr_in as suggested in the man pages, 288 * this iface name will come along for the ride. 289 * (see div_output for the other half of this.) 290 */ 291 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 292 sizeof(divsrc.sin_zero)); 293 } 294 295 /* Put packet on socket queue, if any */ 296 sa = NULL; 297 /* nport is inp_next's context. */ 298 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 299 while ((inp = inp_next(&inpi)) != NULL) { 300 sa = inp->inp_socket; 301 SOCKBUF_LOCK(&sa->so_rcv); 302 if (sbappendaddr_locked(&sa->so_rcv, 303 (struct sockaddr *)&divsrc, m, NULL) == 0) { 304 soroverflow_locked(sa); 305 sa = NULL; /* force mbuf reclaim below */ 306 } else 307 sorwakeup_locked(sa); 308 /* XXX why does only one socket match? */ 309 INP_RUNLOCK(inp); 310 break; 311 } 312 if (sa == NULL) { 313 m_freem(m); 314 KMOD_IPSTAT_INC(ips_noproto); 315 KMOD_IPSTAT_DEC(ips_delivered); 316 } 317 } 318 319 /* 320 * Deliver packet back into the IP processing machinery. 321 * 322 * If no address specified, or address is 0.0.0.0, send to ip_output(); 323 * otherwise, send to ip_input() and mark as having been received on 324 * the interface with that address. 325 */ 326 static int 327 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 328 struct mbuf *control) 329 { 330 struct epoch_tracker et; 331 const struct ip *ip; 332 struct m_tag *mtag; 333 struct ipfw_rule_ref *dt; 334 int error, family; 335 336 if (control) { 337 m_freem(control); /* XXX */ 338 control = NULL; 339 } 340 341 if (sin != NULL) { 342 if (sin->sin_family != AF_INET) { 343 m_freem(m); 344 return (EAFNOSUPPORT); 345 } 346 if (sin->sin_len != sizeof(*sin)) { 347 m_freem(m); 348 return (EINVAL); 349 } 350 } 351 352 /* 353 * An mbuf may hasn't come from userland, but we pretend 354 * that it has. 355 */ 356 m->m_pkthdr.rcvif = NULL; 357 m->m_nextpkt = NULL; 358 M_SETFIB(m, so->so_fibnum); 359 360 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 361 if (mtag == NULL) { 362 /* this should be normal */ 363 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 364 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 365 if (mtag == NULL) { 366 m_freem(m); 367 return (ENOBUFS); 368 } 369 m_tag_prepend(m, mtag); 370 } 371 dt = (struct ipfw_rule_ref *)(mtag+1); 372 373 /* Loopback avoidance and state recovery */ 374 if (sin) { 375 int i; 376 377 /* set the starting point. We provide a non-zero slot, 378 * but a non_matching chain_id to skip that info and use 379 * the rulenum/rule_id. 380 */ 381 dt->slot = 1; /* dummy, chain_id is invalid */ 382 dt->chain_id = 0; 383 dt->rulenum = sin->sin_port+1; /* host format ? */ 384 dt->rule_id = 0; 385 /* XXX: broken for IPv6 */ 386 /* 387 * Find receive interface with the given name, stuffed 388 * (if it exists) in the sin_zero[] field. 389 * The name is user supplied data so don't trust its size 390 * or that it is zero terminated. 391 */ 392 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 393 ; 394 if ( i > 0 && i < sizeof(sin->sin_zero)) 395 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 396 } 397 398 ip = mtod(m, struct ip *); 399 switch (ip->ip_v) { 400 case IPVERSION: 401 family = AF_INET; 402 break; 403 #ifdef INET6 404 case IPV6_VERSION >> 4: 405 family = AF_INET6; 406 break; 407 #endif 408 default: 409 m_freem(m); 410 return (EAFNOSUPPORT); 411 } 412 413 /* Reinject packet into the system as incoming or outgoing */ 414 NET_EPOCH_ENTER(et); 415 if (!sin || sin->sin_addr.s_addr == 0) { 416 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 417 error = div_output_outbound(family, so, m); 418 } else { 419 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 420 error = div_output_inbound(family, so, m, sin); 421 } 422 NET_EPOCH_EXIT(et); 423 424 return (error); 425 } 426 427 /* 428 * Sends mbuf @m to the wire via ip[6]_output(). 429 * 430 * Returns 0 on success or an errno value on failure. @m is always consumed. 431 */ 432 static int 433 div_output_outbound(int family, struct socket *so, struct mbuf *m) 434 { 435 struct ip *const ip = mtod(m, struct ip *); 436 struct mbuf *options; 437 struct inpcb *inp; 438 int error; 439 440 inp = sotoinpcb(so); 441 INP_RLOCK(inp); 442 switch (family) { 443 case AF_INET: 444 /* 445 * Don't allow both user specified and setsockopt 446 * options, and don't allow packet length sizes that 447 * will crash. 448 */ 449 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 450 inp->inp_options != NULL) || 451 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 452 INP_RUNLOCK(inp); 453 m_freem(m); 454 return (EINVAL); 455 } 456 break; 457 #ifdef INET6 458 case AF_INET6: 459 { 460 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 461 462 /* Don't allow packet length sizes that will crash */ 463 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 464 INP_RUNLOCK(inp); 465 m_freem(m); 466 return (EINVAL); 467 } 468 break; 469 } 470 #endif 471 } 472 473 /* Send packet to output processing */ 474 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 475 476 #ifdef MAC 477 mac_inpcb_create_mbuf(inp, m); 478 #endif 479 /* 480 * Get ready to inject the packet into ip_output(). 481 * Just in case socket options were specified on the 482 * divert socket, we duplicate them. This is done 483 * to avoid having to hold the PCB locks over the call 484 * to ip_output(), as doing this results in a number of 485 * lock ordering complexities. 486 * 487 * Note that we set the multicast options argument for 488 * ip_output() to NULL since it should be invariant that 489 * they are not present. 490 */ 491 KASSERT(inp->inp_moptions == NULL, 492 ("multicast options set on a divert socket")); 493 /* 494 * XXXCSJP: It is unclear to me whether or not it makes 495 * sense for divert sockets to have options. However, 496 * for now we will duplicate them with the INP locks 497 * held so we can use them in ip_output() without 498 * requring a reference to the pcb. 499 */ 500 options = NULL; 501 if (inp->inp_options != NULL) { 502 options = m_dup(inp->inp_options, M_NOWAIT); 503 if (options == NULL) { 504 INP_RUNLOCK(inp); 505 m_freem(m); 506 return (ENOBUFS); 507 } 508 } 509 INP_RUNLOCK(inp); 510 511 error = 0; 512 switch (family) { 513 case AF_INET: 514 error = ip_output(m, options, NULL, 515 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 516 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 517 break; 518 #ifdef INET6 519 case AF_INET6: 520 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 521 break; 522 #endif 523 } 524 if (options != NULL) 525 m_freem(options); 526 527 return (error); 528 } 529 530 /* 531 * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue. 532 * 533 * Returns 0 on success or an errno value on failure. @m is always consumed. 534 */ 535 static int 536 div_output_inbound(int family, struct socket *so, struct mbuf *m, 537 struct sockaddr_in *sin) 538 { 539 const struct ip *ip; 540 struct ifaddr *ifa; 541 542 if (m->m_pkthdr.rcvif == NULL) { 543 /* 544 * No luck with the name, check by IP address. 545 * Clear the port and the ifname to make sure 546 * there are no distractions for ifa_ifwithaddr. 547 */ 548 549 /* XXX: broken for IPv6 */ 550 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 551 sin->sin_port = 0; 552 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 553 if (ifa == NULL) { 554 m_freem(m); 555 return (EADDRNOTAVAIL); 556 } 557 m->m_pkthdr.rcvif = ifa->ifa_ifp; 558 } 559 #ifdef MAC 560 mac_socket_create_mbuf(so, m); 561 #endif 562 /* Send packet to input processing via netisr */ 563 switch (family) { 564 case AF_INET: 565 ip = mtod(m, struct ip *); 566 /* 567 * Restore M_BCAST flag when destination address is 568 * broadcast. It is expected by ip_tryforward(). 569 */ 570 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) 571 m->m_flags |= M_MCAST; 572 else if (in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) 573 m->m_flags |= M_BCAST; 574 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 575 break; 576 #ifdef INET6 577 case AF_INET6: 578 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 579 break; 580 #endif 581 default: 582 m_freem(m); 583 return (EINVAL); 584 } 585 586 return (0); 587 } 588 589 static int 590 div_attach(struct socket *so, int proto, struct thread *td) 591 { 592 struct inpcb *inp; 593 int error; 594 595 inp = sotoinpcb(so); 596 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 597 if (td != NULL) { 598 error = priv_check(td, PRIV_NETINET_DIVERT); 599 if (error) 600 return (error); 601 } 602 error = soreserve(so, div_sendspace, div_recvspace); 603 if (error) 604 return error; 605 error = in_pcballoc(so, &V_divcbinfo); 606 if (error) 607 return error; 608 inp = (struct inpcb *)so->so_pcb; 609 inp->inp_ip_p = proto; 610 inp->inp_vflag |= INP_IPV4; 611 inp->inp_flags |= INP_HDRINCL; 612 INP_WUNLOCK(inp); 613 return 0; 614 } 615 616 static void 617 div_detach(struct socket *so) 618 { 619 struct inpcb *inp; 620 621 inp = sotoinpcb(so); 622 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 623 INP_WLOCK(inp); 624 in_pcbdetach(inp); 625 in_pcbfree(inp); 626 } 627 628 static int 629 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 630 { 631 struct inpcb *inp; 632 int error; 633 634 inp = sotoinpcb(so); 635 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 636 /* in_pcbbind assumes that nam is a sockaddr_in 637 * and in_pcbbind requires a valid address. Since divert 638 * sockets don't we need to make sure the address is 639 * filled in properly. 640 * XXX -- divert should not be abusing in_pcbind 641 * and should probably have its own family. 642 */ 643 if (nam->sa_family != AF_INET) 644 return EAFNOSUPPORT; 645 if (nam->sa_len != sizeof(struct sockaddr_in)) 646 return EINVAL; 647 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 648 INP_WLOCK(inp); 649 INP_HASH_WLOCK(&V_divcbinfo); 650 error = in_pcbbind(inp, nam, td->td_ucred); 651 INP_HASH_WUNLOCK(&V_divcbinfo); 652 INP_WUNLOCK(inp); 653 return error; 654 } 655 656 static int 657 div_shutdown(struct socket *so) 658 { 659 struct inpcb *inp; 660 661 inp = sotoinpcb(so); 662 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 663 INP_WLOCK(inp); 664 socantsendmore(so); 665 INP_WUNLOCK(inp); 666 return 0; 667 } 668 669 static int 670 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 671 struct mbuf *control, struct thread *td) 672 { 673 674 /* Packet must have a header (but that's about it) */ 675 if (m->m_len < sizeof (struct ip) && 676 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 677 KMOD_IPSTAT_INC(ips_toosmall); 678 if (control != NULL) 679 m_freem(control); 680 m_freem(m); 681 return EINVAL; 682 } 683 684 /* Send packet */ 685 return div_output(so, m, (struct sockaddr_in *)nam, control); 686 } 687 688 static int 689 div_pcblist(SYSCTL_HANDLER_ARGS) 690 { 691 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_divcbinfo, 692 INPLOOKUP_RLOCKPCB); 693 struct xinpgen xig; 694 struct inpcb *inp; 695 int error; 696 697 if (req->newptr != 0) 698 return EPERM; 699 700 if (req->oldptr == 0) { 701 int n; 702 703 n = V_divcbinfo.ipi_count; 704 n += imax(n / 8, 10); 705 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 706 return 0; 707 } 708 709 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 710 return (error); 711 712 bzero(&xig, sizeof(xig)); 713 xig.xig_len = sizeof xig; 714 xig.xig_count = V_divcbinfo.ipi_count; 715 xig.xig_gen = V_divcbinfo.ipi_gencnt; 716 xig.xig_sogen = so_gencnt; 717 error = SYSCTL_OUT(req, &xig, sizeof xig); 718 if (error) 719 return error; 720 721 while ((inp = inp_next(&inpi)) != NULL) { 722 if (inp->inp_gencnt <= xig.xig_gen) { 723 struct xinpcb xi; 724 725 in_pcbtoxinpcb(inp, &xi); 726 error = SYSCTL_OUT(req, &xi, sizeof xi); 727 if (error) { 728 INP_RUNLOCK(inp); 729 break; 730 } 731 } 732 } 733 734 if (!error) { 735 /* 736 * Give the user an updated idea of our state. 737 * If the generation differs from what we told 738 * her before, she knows that something happened 739 * while we were processing this request, and it 740 * might be necessary to retry. 741 */ 742 xig.xig_gen = V_divcbinfo.ipi_gencnt; 743 xig.xig_sogen = so_gencnt; 744 xig.xig_count = V_divcbinfo.ipi_count; 745 error = SYSCTL_OUT(req, &xig, sizeof xig); 746 } 747 748 return (error); 749 } 750 751 #ifdef SYSCTL_NODE 752 static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, 753 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 754 "IPDIVERT"); 755 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, 756 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 757 NULL, 0, div_pcblist, "S,xinpcb", 758 "List of active divert sockets"); 759 #endif 760 761 struct pr_usrreqs div_usrreqs = { 762 .pru_attach = div_attach, 763 .pru_bind = div_bind, 764 .pru_control = in_control, 765 .pru_detach = div_detach, 766 .pru_peeraddr = in_getpeeraddr, 767 .pru_send = div_send, 768 .pru_shutdown = div_shutdown, 769 .pru_sockaddr = in_getsockaddr, 770 .pru_sosetlabel = in_pcbsosetlabel 771 }; 772 773 struct protosw div_protosw = { 774 .pr_type = SOCK_RAW, 775 .pr_protocol = IPPROTO_DIVERT, 776 .pr_flags = PR_ATOMIC|PR_ADDR, 777 .pr_input = div_input, 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