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 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 224 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 225 } 226 #endif 227 #ifdef INET6 228 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 229 m = mb_unmapped_to_ext(m); 230 if (m == NULL) 231 return; 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 = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 298 CK_LIST_FOREACH(inp, &V_divcb, inp_list) { 299 /* XXX why does only one socket match? */ 300 if (inp->inp_lport == nport) { 301 INP_RLOCK(inp); 302 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 303 INP_RUNLOCK(inp); 304 continue; 305 } 306 sa = inp->inp_socket; 307 SOCKBUF_LOCK(&sa->so_rcv); 308 if (sbappendaddr_locked(&sa->so_rcv, 309 (struct sockaddr *)&divsrc, m, 310 (struct mbuf *)0) == 0) { 311 soroverflow_locked(sa); 312 sa = NULL; /* force mbuf reclaim below */ 313 } else 314 sorwakeup_locked(sa); 315 INP_RUNLOCK(inp); 316 break; 317 } 318 } 319 if (sa == NULL) { 320 m_freem(m); 321 KMOD_IPSTAT_INC(ips_noproto); 322 KMOD_IPSTAT_DEC(ips_delivered); 323 } 324 } 325 326 /* 327 * Deliver packet back into the IP processing machinery. 328 * 329 * If no address specified, or address is 0.0.0.0, send to ip_output(); 330 * otherwise, send to ip_input() and mark as having been received on 331 * the interface with that address. 332 */ 333 static int 334 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 335 struct mbuf *control) 336 { 337 struct epoch_tracker et; 338 const struct ip *ip; 339 struct m_tag *mtag; 340 struct ipfw_rule_ref *dt; 341 int error, family; 342 343 if (control) { 344 m_freem(control); /* XXX */ 345 control = NULL; 346 } 347 348 if (sin != NULL) { 349 if (sin->sin_family != AF_INET) { 350 m_freem(m); 351 return (EAFNOSUPPORT); 352 } 353 if (sin->sin_len != sizeof(*sin)) { 354 m_freem(m); 355 return (EINVAL); 356 } 357 } 358 359 /* 360 * An mbuf may hasn't come from userland, but we pretend 361 * that it has. 362 */ 363 m->m_pkthdr.rcvif = NULL; 364 m->m_nextpkt = NULL; 365 M_SETFIB(m, so->so_fibnum); 366 367 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 368 if (mtag == NULL) { 369 /* this should be normal */ 370 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 371 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 372 if (mtag == NULL) { 373 m_freem(m); 374 return (ENOBUFS); 375 } 376 m_tag_prepend(m, mtag); 377 } 378 dt = (struct ipfw_rule_ref *)(mtag+1); 379 380 /* Loopback avoidance and state recovery */ 381 if (sin) { 382 int i; 383 384 /* set the starting point. We provide a non-zero slot, 385 * but a non_matching chain_id to skip that info and use 386 * the rulenum/rule_id. 387 */ 388 dt->slot = 1; /* dummy, chain_id is invalid */ 389 dt->chain_id = 0; 390 dt->rulenum = sin->sin_port+1; /* host format ? */ 391 dt->rule_id = 0; 392 /* XXX: broken for IPv6 */ 393 /* 394 * Find receive interface with the given name, stuffed 395 * (if it exists) in the sin_zero[] field. 396 * The name is user supplied data so don't trust its size 397 * or that it is zero terminated. 398 */ 399 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 400 ; 401 if ( i > 0 && i < sizeof(sin->sin_zero)) 402 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 403 } 404 405 ip = mtod(m, struct ip *); 406 switch (ip->ip_v) { 407 case IPVERSION: 408 family = AF_INET; 409 break; 410 #ifdef INET6 411 case IPV6_VERSION >> 4: 412 family = AF_INET6; 413 break; 414 #endif 415 default: 416 m_freem(m); 417 return (EAFNOSUPPORT); 418 } 419 420 /* Reinject packet into the system as incoming or outgoing */ 421 NET_EPOCH_ENTER(et); 422 if (!sin || sin->sin_addr.s_addr == 0) { 423 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 424 error = div_output_outbound(family, so, m); 425 } else { 426 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 427 error = div_output_inbound(family, so, m, sin); 428 } 429 NET_EPOCH_EXIT(et); 430 431 return (error); 432 } 433 434 /* 435 * Sends mbuf @m to the wire via ip[6]_output(). 436 * 437 * Returns 0 on success or an errno value on failure. @m is always consumed. 438 */ 439 static int 440 div_output_outbound(int family, struct socket *so, struct mbuf *m) 441 { 442 struct ip *const ip = mtod(m, struct ip *); 443 struct mbuf *options; 444 struct inpcb *inp; 445 int error; 446 447 inp = sotoinpcb(so); 448 INP_RLOCK(inp); 449 switch (family) { 450 case AF_INET: 451 /* 452 * Don't allow both user specified and setsockopt 453 * options, and don't allow packet length sizes that 454 * will crash. 455 */ 456 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 457 inp->inp_options != NULL) || 458 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 459 INP_RUNLOCK(inp); 460 m_freem(m); 461 return (EINVAL); 462 } 463 break; 464 #ifdef INET6 465 case AF_INET6: 466 { 467 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 468 469 /* Don't allow packet length sizes that will crash */ 470 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 471 INP_RUNLOCK(inp); 472 m_freem(m); 473 return (EINVAL); 474 } 475 break; 476 } 477 #endif 478 } 479 480 /* Send packet to output processing */ 481 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 482 483 #ifdef MAC 484 mac_inpcb_create_mbuf(inp, m); 485 #endif 486 /* 487 * Get ready to inject the packet into ip_output(). 488 * Just in case socket options were specified on the 489 * divert socket, we duplicate them. This is done 490 * to avoid having to hold the PCB locks over the call 491 * to ip_output(), as doing this results in a number of 492 * lock ordering complexities. 493 * 494 * Note that we set the multicast options argument for 495 * ip_output() to NULL since it should be invariant that 496 * they are not present. 497 */ 498 KASSERT(inp->inp_moptions == NULL, 499 ("multicast options set on a divert socket")); 500 /* 501 * XXXCSJP: It is unclear to me whether or not it makes 502 * sense for divert sockets to have options. However, 503 * for now we will duplicate them with the INP locks 504 * held so we can use them in ip_output() without 505 * requring a reference to the pcb. 506 */ 507 options = NULL; 508 if (inp->inp_options != NULL) { 509 options = m_dup(inp->inp_options, M_NOWAIT); 510 if (options == NULL) { 511 INP_RUNLOCK(inp); 512 m_freem(m); 513 return (ENOBUFS); 514 } 515 } 516 INP_RUNLOCK(inp); 517 518 error = 0; 519 switch (family) { 520 case AF_INET: 521 error = ip_output(m, options, NULL, 522 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 523 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 524 break; 525 #ifdef INET6 526 case AF_INET6: 527 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 528 break; 529 #endif 530 } 531 if (options != NULL) 532 m_freem(options); 533 534 return (error); 535 } 536 537 /* 538 * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue. 539 * 540 * Returns 0 on success or an errno value on failure. @m is always consumed. 541 */ 542 static int 543 div_output_inbound(int family, struct socket *so, struct mbuf *m, 544 struct sockaddr_in *sin) 545 { 546 const struct ip *ip; 547 struct ifaddr *ifa; 548 549 if (m->m_pkthdr.rcvif == NULL) { 550 /* 551 * No luck with the name, check by IP address. 552 * Clear the port and the ifname to make sure 553 * there are no distractions for ifa_ifwithaddr. 554 */ 555 556 /* XXX: broken for IPv6 */ 557 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 558 sin->sin_port = 0; 559 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 560 if (ifa == NULL) { 561 m_freem(m); 562 return (EADDRNOTAVAIL); 563 } 564 m->m_pkthdr.rcvif = ifa->ifa_ifp; 565 } 566 #ifdef MAC 567 mac_socket_create_mbuf(so, m); 568 #endif 569 /* Send packet to input processing via netisr */ 570 switch (family) { 571 case AF_INET: 572 ip = mtod(m, struct ip *); 573 /* 574 * Restore M_BCAST flag when destination address is 575 * broadcast. It is expected by ip_tryforward(). 576 */ 577 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) 578 m->m_flags |= M_MCAST; 579 else if (in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) 580 m->m_flags |= M_BCAST; 581 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 582 break; 583 #ifdef INET6 584 case AF_INET6: 585 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 586 break; 587 #endif 588 default: 589 m_freem(m); 590 return (EINVAL); 591 } 592 593 return (0); 594 } 595 596 static int 597 div_attach(struct socket *so, int proto, struct thread *td) 598 { 599 struct inpcb *inp; 600 int error; 601 602 inp = sotoinpcb(so); 603 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 604 if (td != NULL) { 605 error = priv_check(td, PRIV_NETINET_DIVERT); 606 if (error) 607 return (error); 608 } 609 error = soreserve(so, div_sendspace, div_recvspace); 610 if (error) 611 return error; 612 INP_INFO_WLOCK(&V_divcbinfo); 613 error = in_pcballoc(so, &V_divcbinfo); 614 if (error) { 615 INP_INFO_WUNLOCK(&V_divcbinfo); 616 return error; 617 } 618 inp = (struct inpcb *)so->so_pcb; 619 INP_INFO_WUNLOCK(&V_divcbinfo); 620 inp->inp_ip_p = proto; 621 inp->inp_vflag |= INP_IPV4; 622 inp->inp_flags |= INP_HDRINCL; 623 INP_WUNLOCK(inp); 624 return 0; 625 } 626 627 static void 628 div_detach(struct socket *so) 629 { 630 struct inpcb *inp; 631 632 inp = sotoinpcb(so); 633 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 634 INP_INFO_WLOCK(&V_divcbinfo); 635 INP_WLOCK(inp); 636 in_pcbdetach(inp); 637 in_pcbfree(inp); 638 INP_INFO_WUNLOCK(&V_divcbinfo); 639 } 640 641 static int 642 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 643 { 644 struct inpcb *inp; 645 int error; 646 647 inp = sotoinpcb(so); 648 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 649 /* in_pcbbind assumes that nam is a sockaddr_in 650 * and in_pcbbind requires a valid address. Since divert 651 * sockets don't we need to make sure the address is 652 * filled in properly. 653 * XXX -- divert should not be abusing in_pcbind 654 * and should probably have its own family. 655 */ 656 if (nam->sa_family != AF_INET) 657 return EAFNOSUPPORT; 658 if (nam->sa_len != sizeof(struct sockaddr_in)) 659 return EINVAL; 660 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 661 INP_INFO_WLOCK(&V_divcbinfo); 662 INP_WLOCK(inp); 663 INP_HASH_WLOCK(&V_divcbinfo); 664 error = in_pcbbind(inp, nam, td->td_ucred); 665 INP_HASH_WUNLOCK(&V_divcbinfo); 666 INP_WUNLOCK(inp); 667 INP_INFO_WUNLOCK(&V_divcbinfo); 668 return error; 669 } 670 671 static int 672 div_shutdown(struct socket *so) 673 { 674 struct inpcb *inp; 675 676 inp = sotoinpcb(so); 677 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 678 INP_WLOCK(inp); 679 socantsendmore(so); 680 INP_WUNLOCK(inp); 681 return 0; 682 } 683 684 static int 685 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 686 struct mbuf *control, struct thread *td) 687 { 688 689 /* Packet must have a header (but that's about it) */ 690 if (m->m_len < sizeof (struct ip) && 691 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 692 KMOD_IPSTAT_INC(ips_toosmall); 693 if (control != NULL) 694 m_freem(control); 695 m_freem(m); 696 return EINVAL; 697 } 698 699 /* Send packet */ 700 return div_output(so, m, (struct sockaddr_in *)nam, control); 701 } 702 703 static int 704 div_pcblist(SYSCTL_HANDLER_ARGS) 705 { 706 struct xinpgen xig; 707 struct epoch_tracker et; 708 struct inpcb *inp; 709 int error; 710 711 if (req->newptr != 0) 712 return EPERM; 713 714 if (req->oldptr == 0) { 715 int n; 716 717 n = V_divcbinfo.ipi_count; 718 n += imax(n / 8, 10); 719 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 720 return 0; 721 } 722 723 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 724 return (error); 725 726 bzero(&xig, sizeof(xig)); 727 xig.xig_len = sizeof xig; 728 xig.xig_count = V_divcbinfo.ipi_count; 729 xig.xig_gen = V_divcbinfo.ipi_gencnt; 730 xig.xig_sogen = so_gencnt; 731 error = SYSCTL_OUT(req, &xig, sizeof xig); 732 if (error) 733 return error; 734 735 NET_EPOCH_ENTER(et); 736 for (inp = CK_LIST_FIRST(V_divcbinfo.ipi_listhead); 737 inp != NULL; 738 inp = CK_LIST_NEXT(inp, inp_list)) { 739 INP_RLOCK(inp); 740 if (inp->inp_gencnt <= xig.xig_gen) { 741 struct xinpcb xi; 742 743 in_pcbtoxinpcb(inp, &xi); 744 INP_RUNLOCK(inp); 745 error = SYSCTL_OUT(req, &xi, sizeof xi); 746 } else 747 INP_RUNLOCK(inp); 748 } 749 NET_EPOCH_EXIT(et); 750 751 if (!error) { 752 /* 753 * Give the user an updated idea of our state. 754 * If the generation differs from what we told 755 * her before, she knows that something happened 756 * while we were processing this request, and it 757 * might be necessary to retry. 758 */ 759 xig.xig_gen = V_divcbinfo.ipi_gencnt; 760 xig.xig_sogen = so_gencnt; 761 xig.xig_count = V_divcbinfo.ipi_count; 762 error = SYSCTL_OUT(req, &xig, sizeof xig); 763 } 764 765 return (error); 766 } 767 768 #ifdef SYSCTL_NODE 769 static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, 770 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 771 "IPDIVERT"); 772 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, 773 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 774 NULL, 0, div_pcblist, "S,xinpcb", 775 "List of active divert sockets"); 776 #endif 777 778 struct pr_usrreqs div_usrreqs = { 779 .pru_attach = div_attach, 780 .pru_bind = div_bind, 781 .pru_control = in_control, 782 .pru_detach = div_detach, 783 .pru_peeraddr = in_getpeeraddr, 784 .pru_send = div_send, 785 .pru_shutdown = div_shutdown, 786 .pru_sockaddr = in_getsockaddr, 787 .pru_sosetlabel = in_pcbsosetlabel 788 }; 789 790 struct protosw div_protosw = { 791 .pr_type = SOCK_RAW, 792 .pr_protocol = IPPROTO_DIVERT, 793 .pr_flags = PR_ATOMIC|PR_ADDR, 794 .pr_input = div_input, 795 .pr_init = div_init, 796 .pr_usrreqs = &div_usrreqs 797 }; 798 799 static int 800 div_modevent(module_t mod, int type, void *unused) 801 { 802 int err = 0; 803 804 switch (type) { 805 case MOD_LOAD: 806 /* 807 * Protocol will be initialized by pf_proto_register(). 808 * We don't have to register ip_protox because we are not 809 * a true IP protocol that goes over the wire. 810 */ 811 err = pf_proto_register(PF_INET, &div_protosw); 812 if (err != 0) 813 return (err); 814 ip_divert_ptr = divert_packet; 815 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 816 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 817 break; 818 case MOD_QUIESCE: 819 /* 820 * IPDIVERT may normally not be unloaded because of the 821 * potential race conditions. Tell kldunload we can't be 822 * unloaded unless the unload is forced. 823 */ 824 err = EPERM; 825 break; 826 case MOD_UNLOAD: 827 /* 828 * Forced unload. 829 * 830 * Module ipdivert can only be unloaded if no sockets are 831 * connected. Maybe this can be changed later to forcefully 832 * disconnect any open sockets. 833 * 834 * XXXRW: Note that there is a slight race here, as a new 835 * socket open request could be spinning on the lock and then 836 * we destroy the lock. 837 */ 838 INP_INFO_WLOCK(&V_divcbinfo); 839 if (V_divcbinfo.ipi_count != 0) { 840 err = EBUSY; 841 INP_INFO_WUNLOCK(&V_divcbinfo); 842 break; 843 } 844 ip_divert_ptr = NULL; 845 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 846 INP_INFO_WUNLOCK(&V_divcbinfo); 847 #ifndef VIMAGE 848 div_destroy(NULL); 849 #endif 850 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 851 break; 852 default: 853 err = EOPNOTSUPP; 854 break; 855 } 856 return err; 857 } 858 859 static moduledata_t ipdivertmod = { 860 "ipdivert", 861 div_modevent, 862 0 863 }; 864 865 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 866 MODULE_DEPEND(ipdivert, ipfw, 3, 3, 3); 867 MODULE_VERSION(ipdivert, 1); 868