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. */ 114VNET_DEFINE_STATIC(struct inpcbhead, divcb); 115VNET_DEFINE_STATIC(struct inpcbinfo, divcbinfo); 116 117#define V_divcb VNET(divcb) 118#define V_divcbinfo VNET(divcbinfo) 119 120static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 121static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 122 123static eventhandler_tag ip_divert_event_tag; 124 125static int div_output_inbound(int fmaily, struct socket *so, struct mbuf *m, 126 struct sockaddr_in *sin); 127static int div_output_outbound(int family, struct socket *so, struct mbuf *m); 128 129/* 130 * Initialize divert connection block queue. 131 */ 132static void 133div_zone_change(void *tag) 134{ 135 136 uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets); 137} 138 139static int 140div_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 148static void 149div_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 161static void 162div_destroy(void *unused __unused) 163{ 164 165 in_pcbinfo_destroy(&V_divcbinfo); 166} 167VNET_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 */ 174static int 175div_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 */ 190static void 191divert_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 */ 320static int 321div_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 if (control) { 331 m_freem(control); /* XXX */ 332 control = NULL; 333 } 334 335 if (sin != NULL) { 336 if (sin->sin_family != AF_INET) { 337 m_freem(m); 338 return (EAFNOSUPPORT); 339 } 340 if (sin->sin_len != sizeof(*sin)) { 341 m_freem(m); 342 return (EINVAL); 343 } 344 } 345 346 /* 347 * An mbuf may hasn't come from userland, but we pretend 348 * that it has. 349 */ 350 m->m_pkthdr.rcvif = NULL; 351 m->m_nextpkt = NULL; 352 M_SETFIB(m, so->so_fibnum); 353 354 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 355 if (mtag == NULL) { 356 /* this should be normal */ 357 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 358 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 359 if (mtag == NULL) { 360 m_freem(m); 361 return (ENOBUFS); 362 } 363 m_tag_prepend(m, mtag); 364 } 365 dt = (struct ipfw_rule_ref *)(mtag+1); 366 367 /* Loopback avoidance and state recovery */ 368 if (sin) { 369 int i; 370 371 /* set the starting point. We provide a non-zero slot, 372 * but a non_matching chain_id to skip that info and use 373 * the rulenum/rule_id. 374 */ 375 dt->slot = 1; /* dummy, chain_id is invalid */ 376 dt->chain_id = 0; 377 dt->rulenum = sin->sin_port+1; /* host format ? */ 378 dt->rule_id = 0; 379 /* XXX: broken for IPv6 */ 380 /* 381 * Find receive interface with the given name, stuffed 382 * (if it exists) in the sin_zero[] field. 383 * The name is user supplied data so don't trust its size 384 * or that it is zero terminated. 385 */ 386 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 387 ; 388 if ( i > 0 && i < sizeof(sin->sin_zero)) 389 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 390 } 391 392 ip = mtod(m, struct ip *); 393 switch (ip->ip_v) { 394 case IPVERSION: 395 family = AF_INET; 396 break; 397#ifdef INET6 398 case IPV6_VERSION >> 4: 399 family = AF_INET6; 400 break; 401#endif 402 default: 403 m_freem(m); 404 return (EAFNOSUPPORT); 405 } 406 407 /* Reinject packet into the system as incoming or outgoing */ 408 NET_EPOCH_ENTER(et); 409 if (!sin || sin->sin_addr.s_addr == 0) { 410 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 411 error = div_output_outbound(family, so, m); 412 } else { 413 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 414 error = div_output_inbound(family, so, m, sin); 415 } 416 NET_EPOCH_EXIT(et); 417 418 return (error); 419} 420 421/* 422 * Sends mbuf @m to the wire via ip[6]_output(). 423 * 424 * Returns 0 on success or an errno value on failure. @m is always consumed. 425 */ 426static int 427div_output_outbound(int family, struct socket *so, struct mbuf *m) 428{ 429 struct ip *const ip = mtod(m, struct ip *); 430 struct mbuf *options; 431 struct inpcb *inp; 432 int error; 433 434 inp = sotoinpcb(so); 435 INP_RLOCK(inp); 436 switch (family) { 437 case AF_INET: 438 /* 439 * Don't allow both user specified and setsockopt 440 * options, and don't allow packet length sizes that 441 * will crash. 442 */ 443 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 444 inp->inp_options != NULL) || 445 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 446 INP_RUNLOCK(inp); 447 m_freem(m); 448 return (EINVAL); 449 } 450 break; 451#ifdef INET6 452 case AF_INET6: 453 { 454 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 455 456 /* Don't allow packet length sizes that will crash */ 457 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 458 INP_RUNLOCK(inp); 459 m_freem(m); 460 return (EINVAL); 461 } 462 break; 463 } 464#endif 465 } 466 467 /* Send packet to output processing */ 468 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 469 470#ifdef MAC 471 mac_inpcb_create_mbuf(inp, m); 472#endif 473 /* 474 * Get ready to inject the packet into ip_output(). 475 * Just in case socket options were specified on the 476 * divert socket, we duplicate them. This is done 477 * to avoid having to hold the PCB locks over the call 478 * to ip_output(), as doing this results in a number of 479 * lock ordering complexities. 480 * 481 * Note that we set the multicast options argument for 482 * ip_output() to NULL since it should be invariant that 483 * they are not present. 484 */ 485 KASSERT(inp->inp_moptions == NULL, 486 ("multicast options set on a divert socket")); 487 /* 488 * XXXCSJP: It is unclear to me whether or not it makes 489 * sense for divert sockets to have options. However, 490 * for now we will duplicate them with the INP locks 491 * held so we can use them in ip_output() without 492 * requring a reference to the pcb. 493 */ 494 options = NULL; 495 if (inp->inp_options != NULL) { 496 options = m_dup(inp->inp_options, M_NOWAIT); 497 if (options == NULL) { 498 INP_RUNLOCK(inp); 499 m_freem(m); 500 return (ENOBUFS); 501 } 502 } 503 INP_RUNLOCK(inp); 504 505 error = 0; 506 switch (family) { 507 case AF_INET: 508 error = ip_output(m, options, NULL, 509 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 510 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 511 break; 512#ifdef INET6 513 case AF_INET6: 514 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 515 break; 516#endif 517 } 518 if (options != NULL) 519 m_freem(options); 520 521 return (error); 522} 523 524/* 525 * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue. 526 * 527 * Returns 0 on success or an errno value on failure. @m is always consumed. 528 */ 529static int 530div_output_inbound(int family, struct socket *so, struct mbuf *m, 531 struct sockaddr_in *sin) 532{ 533 const struct ip *ip; 534 struct ifaddr *ifa; 535 536 if (m->m_pkthdr.rcvif == NULL) { 537 /* 538 * No luck with the name, check by IP address. 539 * Clear the port and the ifname to make sure 540 * there are no distractions for ifa_ifwithaddr. 541 */ 542 543 /* XXX: broken for IPv6 */ 544 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 545 sin->sin_port = 0; 546 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 547 if (ifa == NULL) { 548 m_freem(m); 549 return (EADDRNOTAVAIL); 550 } 551 m->m_pkthdr.rcvif = ifa->ifa_ifp; 552 } 553#ifdef MAC 554 mac_socket_create_mbuf(so, m); 555#endif 556 /* Send packet to input processing via netisr */ 557 switch (family) { 558 case AF_INET: 559 ip = mtod(m, struct ip *); 560 /* 561 * Restore M_BCAST flag when destination address is 562 * broadcast. It is expected by ip_tryforward(). 563 */ 564 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) 565 m->m_flags |= M_MCAST; 566 else if (in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) 567 m->m_flags |= M_BCAST; 568 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 569 break; 570#ifdef INET6 571 case AF_INET6: 572 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 573 break; 574#endif 575 default: 576 m_freem(m); 577 return (EINVAL); 578 } 579 580 return (0); 581} 582 583static int 584div_attach(struct socket *so, int proto, struct thread *td) 585{ 586 struct inpcb *inp; 587 int error; 588 589 inp = sotoinpcb(so); 590 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 591 if (td != NULL) { 592 error = priv_check(td, PRIV_NETINET_DIVERT); 593 if (error) 594 return (error); 595 } 596 error = soreserve(so, div_sendspace, div_recvspace); 597 if (error) 598 return error; 599 INP_INFO_WLOCK(&V_divcbinfo); 600 error = in_pcballoc(so, &V_divcbinfo); 601 if (error) { 602 INP_INFO_WUNLOCK(&V_divcbinfo); 603 return error; 604 } 605 inp = (struct inpcb *)so->so_pcb; 606 INP_INFO_WUNLOCK(&V_divcbinfo); 607 inp->inp_ip_p = proto; 608 inp->inp_vflag |= INP_IPV4; 609 inp->inp_flags |= INP_HDRINCL; 610 INP_WUNLOCK(inp); 611 return 0; 612} 613 614static void 615div_detach(struct socket *so) 616{ 617 struct inpcb *inp; 618 619 inp = sotoinpcb(so); 620 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 621 INP_INFO_WLOCK(&V_divcbinfo); 622 INP_WLOCK(inp); 623 in_pcbdetach(inp); 624 in_pcbfree(inp); 625 INP_INFO_WUNLOCK(&V_divcbinfo); 626} 627 628static int 629div_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_INFO_WLOCK(&V_divcbinfo); 649 INP_WLOCK(inp); 650 INP_HASH_WLOCK(&V_divcbinfo); 651 error = in_pcbbind(inp, nam, td->td_ucred); 652 INP_HASH_WUNLOCK(&V_divcbinfo); 653 INP_WUNLOCK(inp); 654 INP_INFO_WUNLOCK(&V_divcbinfo); 655 return error; 656} 657 658static int 659div_shutdown(struct socket *so) 660{ 661 struct inpcb *inp; 662 663 inp = sotoinpcb(so); 664 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 665 INP_WLOCK(inp); 666 socantsendmore(so); 667 INP_WUNLOCK(inp); 668 return 0; 669} 670 671static int 672div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 673 struct mbuf *control, struct thread *td) 674{ 675 676 /* Packet must have a header (but that's about it) */ 677 if (m->m_len < sizeof (struct ip) && 678 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 679 KMOD_IPSTAT_INC(ips_toosmall); 680 if (control != NULL) 681 m_freem(control); 682 m_freem(m); 683 return EINVAL; 684 } 685 686 /* Send packet */ 687 return div_output(so, m, (struct sockaddr_in *)nam, control); 688} 689 690static void 691div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 692{ 693 struct in_addr faddr; 694 695 faddr = ((struct sockaddr_in *)sa)->sin_addr; 696 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 697 return; 698 if (PRC_IS_REDIRECT(cmd)) 699 return; 700} 701 702static int 703div_pcblist(SYSCTL_HANDLER_ARGS) 704{ 705 struct xinpgen xig; 706 struct epoch_tracker et; 707 struct inpcb *inp; 708 int error; 709 710 if (req->newptr != 0) 711 return EPERM; 712 713 if (req->oldptr == 0) { 714 int n; 715 716 n = V_divcbinfo.ipi_count; 717 n += imax(n / 8, 10); 718 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 719 return 0; 720 } 721 722 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 723 return (error); 724 725 bzero(&xig, sizeof(xig)); 726 xig.xig_len = sizeof xig; 727 xig.xig_count = V_divcbinfo.ipi_count; 728 xig.xig_gen = V_divcbinfo.ipi_gencnt; 729 xig.xig_sogen = so_gencnt; 730 error = SYSCTL_OUT(req, &xig, sizeof xig); 731 if (error) 732 return error; 733 734 NET_EPOCH_ENTER(et); 735 for (inp = CK_LIST_FIRST(V_divcbinfo.ipi_listhead); 736 inp != NULL; 737 inp = CK_LIST_NEXT(inp, inp_list)) { 738 INP_RLOCK(inp); 739 if (inp->inp_gencnt <= xig.xig_gen) { 740 struct xinpcb xi; 741 742 in_pcbtoxinpcb(inp, &xi); 743 INP_RUNLOCK(inp); 744 error = SYSCTL_OUT(req, &xi, sizeof xi); 745 } else 746 INP_RUNLOCK(inp); 747 } 748 NET_EPOCH_EXIT(et); 749 750 if (!error) { 751 /* 752 * Give the user an updated idea of our state. 753 * If the generation differs from what we told 754 * her before, she knows that something happened 755 * while we were processing this request, and it 756 * might be necessary to retry. 757 */ 758 xig.xig_gen = V_divcbinfo.ipi_gencnt; 759 xig.xig_sogen = so_gencnt; 760 xig.xig_count = V_divcbinfo.ipi_count; 761 error = SYSCTL_OUT(req, &xig, sizeof xig); 762 } 763 764 return (error); 765} 766 767#ifdef SYSCTL_NODE 768static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, 769 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 770 "IPDIVERT"); 771SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, 772 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 773 NULL, 0, div_pcblist, "S,xinpcb", 774 "List of active divert sockets"); 775#endif 776 777struct pr_usrreqs div_usrreqs = { 778 .pru_attach = div_attach, 779 .pru_bind = div_bind, 780 .pru_control = in_control, 781 .pru_detach = div_detach, 782 .pru_peeraddr = in_getpeeraddr, 783 .pru_send = div_send, 784 .pru_shutdown = div_shutdown, 785 .pru_sockaddr = in_getsockaddr, 786 .pru_sosetlabel = in_pcbsosetlabel 787}; 788 789struct protosw div_protosw = { 790 .pr_type = SOCK_RAW, 791 .pr_protocol = IPPROTO_DIVERT, 792 .pr_flags = PR_ATOMIC|PR_ADDR, 793 .pr_input = div_input, 794 .pr_ctlinput = div_ctlinput, 795 .pr_ctloutput = ip_ctloutput, 796 .pr_init = div_init, 797 .pr_usrreqs = &div_usrreqs 798}; 799 800static int 801div_modevent(module_t mod, int type, void *unused) 802{ 803 int err = 0; 804 805 switch (type) { 806 case MOD_LOAD: 807 /* 808 * Protocol will be initialized by pf_proto_register(). 809 * We don't have to register ip_protox because we are not 810 * a true IP protocol that goes over the wire. 811 */ 812 err = pf_proto_register(PF_INET, &div_protosw); 813 if (err != 0) 814 return (err); 815 ip_divert_ptr = divert_packet; 816 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 817 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 818 break; 819 case MOD_QUIESCE: 820 /* 821 * IPDIVERT may normally not be unloaded because of the 822 * potential race conditions. Tell kldunload we can't be 823 * unloaded unless the unload is forced. 824 */ 825 err = EPERM; 826 break; 827 case MOD_UNLOAD: 828 /* 829 * Forced unload. 830 * 831 * Module ipdivert can only be unloaded if no sockets are 832 * connected. Maybe this can be changed later to forcefully 833 * disconnect any open sockets. 834 * 835 * XXXRW: Note that there is a slight race here, as a new 836 * socket open request could be spinning on the lock and then 837 * we destroy the lock. 838 */ 839 INP_INFO_WLOCK(&V_divcbinfo); 840 if (V_divcbinfo.ipi_count != 0) { 841 err = EBUSY; 842 INP_INFO_WUNLOCK(&V_divcbinfo); 843 break; 844 } 845 ip_divert_ptr = NULL; 846 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 847 INP_INFO_WUNLOCK(&V_divcbinfo); 848#ifndef VIMAGE 849 div_destroy(NULL); 850#endif 851 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 852 break; 853 default: 854 err = EOPNOTSUPP; 855 break; 856 } 857 return err; 858} 859 860static moduledata_t ipdivertmod = { 861 "ipdivert", 862 div_modevent, 863 0 864}; 865 866DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 867MODULE_DEPEND(ipdivert, ipfw, 3, 3, 3); 868MODULE_VERSION(ipdivert, 1); 869