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 #ifdef INET6 231 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 232 m = mb_unmapped_to_ext(m); 233 if (m == NULL) 234 return; 235 in6_delayed_cksum(m, m->m_pkthdr.len - 236 sizeof(struct ip6_hdr), sizeof(struct ip6_hdr)); 237 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; 238 } 239 #if defined(SCTP) || defined(SCTP_SUPPORT) 240 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { 241 m = mb_unmapped_to_ext(m); 242 if (m == NULL) 243 return; 244 sctp_delayed_cksum(m, sizeof(struct ip6_hdr)); 245 m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; 246 } 247 #endif 248 #endif /* INET6 */ 249 bzero(&divsrc, sizeof(divsrc)); 250 divsrc.sin_len = sizeof(divsrc); 251 divsrc.sin_family = AF_INET; 252 /* record matching rule, in host format */ 253 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 254 /* 255 * Record receive interface address, if any. 256 * But only for incoming packets. 257 */ 258 if (incoming) { 259 struct ifaddr *ifa; 260 struct ifnet *ifp; 261 262 /* Sanity check */ 263 M_ASSERTPKTHDR(m); 264 265 /* Find IP address for receive interface */ 266 ifp = m->m_pkthdr.rcvif; 267 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 268 if (ifa->ifa_addr->sa_family != AF_INET) 269 continue; 270 divsrc.sin_addr = 271 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 272 break; 273 } 274 } 275 /* 276 * Record the incoming interface name whenever we have one. 277 */ 278 if (m->m_pkthdr.rcvif) { 279 /* 280 * Hide the actual interface name in there in the 281 * sin_zero array. XXX This needs to be moved to a 282 * different sockaddr type for divert, e.g. 283 * sockaddr_div with multiple fields like 284 * sockaddr_dl. Presently we have only 7 bytes 285 * but that will do for now as most interfaces 286 * are 4 or less + 2 or less bytes for unit. 287 * There is probably a faster way of doing this, 288 * possibly taking it from the sockaddr_dl on the iface. 289 * This solves the problem of a P2P link and a LAN interface 290 * having the same address, which can result in the wrong 291 * interface being assigned to the packet when fed back 292 * into the divert socket. Theoretically if the daemon saves 293 * and re-uses the sockaddr_in as suggested in the man pages, 294 * this iface name will come along for the ride. 295 * (see div_output for the other half of this.) 296 */ 297 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 298 sizeof(divsrc.sin_zero)); 299 } 300 301 /* Put packet on socket queue, if any */ 302 sa = NULL; 303 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 304 CK_LIST_FOREACH(inp, &V_divcb, inp_list) { 305 /* XXX why does only one socket match? */ 306 if (inp->inp_lport == nport) { 307 INP_RLOCK(inp); 308 if (__predict_false(inp->inp_flags2 & INP_FREED)) { 309 INP_RUNLOCK(inp); 310 continue; 311 } 312 sa = inp->inp_socket; 313 SOCKBUF_LOCK(&sa->so_rcv); 314 if (sbappendaddr_locked(&sa->so_rcv, 315 (struct sockaddr *)&divsrc, m, 316 (struct mbuf *)0) == 0) { 317 soroverflow_locked(sa); 318 sa = NULL; /* force mbuf reclaim below */ 319 } else 320 sorwakeup_locked(sa); 321 INP_RUNLOCK(inp); 322 break; 323 } 324 } 325 if (sa == NULL) { 326 m_freem(m); 327 KMOD_IPSTAT_INC(ips_noproto); 328 KMOD_IPSTAT_DEC(ips_delivered); 329 } 330 } 331 332 /* 333 * Deliver packet back into the IP processing machinery. 334 * 335 * If no address specified, or address is 0.0.0.0, send to ip_output(); 336 * otherwise, send to ip_input() and mark as having been received on 337 * the interface with that address. 338 */ 339 static int 340 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 341 struct mbuf *control) 342 { 343 struct epoch_tracker et; 344 const struct ip *ip; 345 struct m_tag *mtag; 346 struct ipfw_rule_ref *dt; 347 int error, family; 348 349 if (control) { 350 m_freem(control); /* XXX */ 351 control = NULL; 352 } 353 354 if (sin != NULL) { 355 if (sin->sin_family != AF_INET) { 356 m_freem(m); 357 return (EAFNOSUPPORT); 358 } 359 if (sin->sin_len != sizeof(*sin)) { 360 m_freem(m); 361 return (EINVAL); 362 } 363 } 364 365 /* 366 * An mbuf may hasn't come from userland, but we pretend 367 * that it has. 368 */ 369 m->m_pkthdr.rcvif = NULL; 370 m->m_nextpkt = NULL; 371 M_SETFIB(m, so->so_fibnum); 372 373 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 374 if (mtag == NULL) { 375 /* this should be normal */ 376 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 377 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 378 if (mtag == NULL) { 379 m_freem(m); 380 return (ENOBUFS); 381 } 382 m_tag_prepend(m, mtag); 383 } 384 dt = (struct ipfw_rule_ref *)(mtag+1); 385 386 /* Loopback avoidance and state recovery */ 387 if (sin) { 388 int i; 389 390 /* set the starting point. We provide a non-zero slot, 391 * but a non_matching chain_id to skip that info and use 392 * the rulenum/rule_id. 393 */ 394 dt->slot = 1; /* dummy, chain_id is invalid */ 395 dt->chain_id = 0; 396 dt->rulenum = sin->sin_port+1; /* host format ? */ 397 dt->rule_id = 0; 398 /* XXX: broken for IPv6 */ 399 /* 400 * Find receive interface with the given name, stuffed 401 * (if it exists) in the sin_zero[] field. 402 * The name is user supplied data so don't trust its size 403 * or that it is zero terminated. 404 */ 405 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 406 ; 407 if ( i > 0 && i < sizeof(sin->sin_zero)) 408 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 409 } 410 411 ip = mtod(m, struct ip *); 412 switch (ip->ip_v) { 413 case IPVERSION: 414 family = AF_INET; 415 break; 416 #ifdef INET6 417 case IPV6_VERSION >> 4: 418 family = AF_INET6; 419 break; 420 #endif 421 default: 422 m_freem(m); 423 return (EAFNOSUPPORT); 424 } 425 426 /* Reinject packet into the system as incoming or outgoing */ 427 NET_EPOCH_ENTER(et); 428 if (!sin || sin->sin_addr.s_addr == 0) { 429 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 430 error = div_output_outbound(family, so, m); 431 } else { 432 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 433 error = div_output_inbound(family, so, m, sin); 434 } 435 NET_EPOCH_EXIT(et); 436 437 return (error); 438 } 439 440 /* 441 * Sends mbuf @m to the wire via ip[6]_output(). 442 * 443 * Returns 0 on success or an errno value on failure. @m is always consumed. 444 */ 445 static int 446 div_output_outbound(int family, struct socket *so, struct mbuf *m) 447 { 448 struct ip *const ip = mtod(m, struct ip *); 449 struct mbuf *options; 450 struct inpcb *inp; 451 int error; 452 453 inp = sotoinpcb(so); 454 INP_RLOCK(inp); 455 switch (family) { 456 case AF_INET: 457 /* 458 * Don't allow both user specified and setsockopt 459 * options, and don't allow packet length sizes that 460 * will crash. 461 */ 462 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 463 inp->inp_options != NULL) || 464 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 465 INP_RUNLOCK(inp); 466 m_freem(m); 467 return (EINVAL); 468 } 469 break; 470 #ifdef INET6 471 case AF_INET6: 472 { 473 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 474 475 /* Don't allow packet length sizes that will crash */ 476 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 477 INP_RUNLOCK(inp); 478 m_freem(m); 479 return (EINVAL); 480 } 481 break; 482 } 483 #endif 484 } 485 486 /* Send packet to output processing */ 487 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 488 489 #ifdef MAC 490 mac_inpcb_create_mbuf(inp, m); 491 #endif 492 /* 493 * Get ready to inject the packet into ip_output(). 494 * Just in case socket options were specified on the 495 * divert socket, we duplicate them. This is done 496 * to avoid having to hold the PCB locks over the call 497 * to ip_output(), as doing this results in a number of 498 * lock ordering complexities. 499 * 500 * Note that we set the multicast options argument for 501 * ip_output() to NULL since it should be invariant that 502 * they are not present. 503 */ 504 KASSERT(inp->inp_moptions == NULL, 505 ("multicast options set on a divert socket")); 506 /* 507 * XXXCSJP: It is unclear to me whether or not it makes 508 * sense for divert sockets to have options. However, 509 * for now we will duplicate them with the INP locks 510 * held so we can use them in ip_output() without 511 * requring a reference to the pcb. 512 */ 513 options = NULL; 514 if (inp->inp_options != NULL) { 515 options = m_dup(inp->inp_options, M_NOWAIT); 516 if (options == NULL) { 517 INP_RUNLOCK(inp); 518 m_freem(m); 519 return (ENOBUFS); 520 } 521 } 522 INP_RUNLOCK(inp); 523 524 error = 0; 525 switch (family) { 526 case AF_INET: 527 error = ip_output(m, options, NULL, 528 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 529 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 530 break; 531 #ifdef INET6 532 case AF_INET6: 533 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 534 break; 535 #endif 536 } 537 if (options != NULL) 538 m_freem(options); 539 540 return (error); 541 } 542 543 /* 544 * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue. 545 * 546 * Returns 0 on success or an errno value on failure. @m is always consumed. 547 */ 548 static int 549 div_output_inbound(int family, struct socket *so, struct mbuf *m, 550 struct sockaddr_in *sin) 551 { 552 const struct ip *ip; 553 struct ifaddr *ifa; 554 555 if (m->m_pkthdr.rcvif == NULL) { 556 /* 557 * No luck with the name, check by IP address. 558 * Clear the port and the ifname to make sure 559 * there are no distractions for ifa_ifwithaddr. 560 */ 561 562 /* XXX: broken for IPv6 */ 563 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 564 sin->sin_port = 0; 565 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 566 if (ifa == NULL) { 567 m_freem(m); 568 return (EADDRNOTAVAIL); 569 } 570 m->m_pkthdr.rcvif = ifa->ifa_ifp; 571 } 572 #ifdef MAC 573 mac_socket_create_mbuf(so, m); 574 #endif 575 /* Send packet to input processing via netisr */ 576 switch (family) { 577 case AF_INET: 578 ip = mtod(m, struct ip *); 579 /* 580 * Restore M_BCAST flag when destination address is 581 * broadcast. It is expected by ip_tryforward(). 582 */ 583 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) 584 m->m_flags |= M_MCAST; 585 else if (in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) 586 m->m_flags |= M_BCAST; 587 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 588 break; 589 #ifdef INET6 590 case AF_INET6: 591 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 592 break; 593 #endif 594 default: 595 m_freem(m); 596 return (EINVAL); 597 } 598 599 return (0); 600 } 601 602 static int 603 div_attach(struct socket *so, int proto, struct thread *td) 604 { 605 struct inpcb *inp; 606 int error; 607 608 inp = sotoinpcb(so); 609 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 610 if (td != NULL) { 611 error = priv_check(td, PRIV_NETINET_DIVERT); 612 if (error) 613 return (error); 614 } 615 error = soreserve(so, div_sendspace, div_recvspace); 616 if (error) 617 return error; 618 INP_INFO_WLOCK(&V_divcbinfo); 619 error = in_pcballoc(so, &V_divcbinfo); 620 if (error) { 621 INP_INFO_WUNLOCK(&V_divcbinfo); 622 return error; 623 } 624 inp = (struct inpcb *)so->so_pcb; 625 INP_INFO_WUNLOCK(&V_divcbinfo); 626 inp->inp_ip_p = proto; 627 inp->inp_vflag |= INP_IPV4; 628 inp->inp_flags |= INP_HDRINCL; 629 INP_WUNLOCK(inp); 630 return 0; 631 } 632 633 static void 634 div_detach(struct socket *so) 635 { 636 struct inpcb *inp; 637 638 inp = sotoinpcb(so); 639 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 640 INP_INFO_WLOCK(&V_divcbinfo); 641 INP_WLOCK(inp); 642 in_pcbdetach(inp); 643 in_pcbfree(inp); 644 INP_INFO_WUNLOCK(&V_divcbinfo); 645 } 646 647 static int 648 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 649 { 650 struct inpcb *inp; 651 int error; 652 653 inp = sotoinpcb(so); 654 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 655 /* in_pcbbind assumes that nam is a sockaddr_in 656 * and in_pcbbind requires a valid address. Since divert 657 * sockets don't we need to make sure the address is 658 * filled in properly. 659 * XXX -- divert should not be abusing in_pcbind 660 * and should probably have its own family. 661 */ 662 if (nam->sa_family != AF_INET) 663 return EAFNOSUPPORT; 664 if (nam->sa_len != sizeof(struct sockaddr_in)) 665 return EINVAL; 666 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 667 INP_INFO_WLOCK(&V_divcbinfo); 668 INP_WLOCK(inp); 669 INP_HASH_WLOCK(&V_divcbinfo); 670 error = in_pcbbind(inp, nam, td->td_ucred); 671 INP_HASH_WUNLOCK(&V_divcbinfo); 672 INP_WUNLOCK(inp); 673 INP_INFO_WUNLOCK(&V_divcbinfo); 674 return error; 675 } 676 677 static int 678 div_shutdown(struct socket *so) 679 { 680 struct inpcb *inp; 681 682 inp = sotoinpcb(so); 683 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 684 INP_WLOCK(inp); 685 socantsendmore(so); 686 INP_WUNLOCK(inp); 687 return 0; 688 } 689 690 static int 691 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 692 struct mbuf *control, struct thread *td) 693 { 694 695 /* Packet must have a header (but that's about it) */ 696 if (m->m_len < sizeof (struct ip) && 697 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 698 KMOD_IPSTAT_INC(ips_toosmall); 699 if (control != NULL) 700 m_freem(control); 701 m_freem(m); 702 return EINVAL; 703 } 704 705 /* Send packet */ 706 return div_output(so, m, (struct sockaddr_in *)nam, control); 707 } 708 709 static int 710 div_pcblist(SYSCTL_HANDLER_ARGS) 711 { 712 struct xinpgen xig; 713 struct epoch_tracker et; 714 struct inpcb *inp; 715 int error; 716 717 if (req->newptr != 0) 718 return EPERM; 719 720 if (req->oldptr == 0) { 721 int n; 722 723 n = V_divcbinfo.ipi_count; 724 n += imax(n / 8, 10); 725 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 726 return 0; 727 } 728 729 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 730 return (error); 731 732 bzero(&xig, sizeof(xig)); 733 xig.xig_len = sizeof xig; 734 xig.xig_count = V_divcbinfo.ipi_count; 735 xig.xig_gen = V_divcbinfo.ipi_gencnt; 736 xig.xig_sogen = so_gencnt; 737 error = SYSCTL_OUT(req, &xig, sizeof xig); 738 if (error) 739 return error; 740 741 NET_EPOCH_ENTER(et); 742 for (inp = CK_LIST_FIRST(V_divcbinfo.ipi_listhead); 743 inp != NULL; 744 inp = CK_LIST_NEXT(inp, inp_list)) { 745 INP_RLOCK(inp); 746 if (inp->inp_gencnt <= xig.xig_gen) { 747 struct xinpcb xi; 748 749 in_pcbtoxinpcb(inp, &xi); 750 INP_RUNLOCK(inp); 751 error = SYSCTL_OUT(req, &xi, sizeof xi); 752 } else 753 INP_RUNLOCK(inp); 754 } 755 NET_EPOCH_EXIT(et); 756 757 if (!error) { 758 /* 759 * Give the user an updated idea of our state. 760 * If the generation differs from what we told 761 * her before, she knows that something happened 762 * while we were processing this request, and it 763 * might be necessary to retry. 764 */ 765 xig.xig_gen = V_divcbinfo.ipi_gencnt; 766 xig.xig_sogen = so_gencnt; 767 xig.xig_count = V_divcbinfo.ipi_count; 768 error = SYSCTL_OUT(req, &xig, sizeof xig); 769 } 770 771 return (error); 772 } 773 774 #ifdef SYSCTL_NODE 775 static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, 776 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 777 "IPDIVERT"); 778 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, 779 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 780 NULL, 0, div_pcblist, "S,xinpcb", 781 "List of active divert sockets"); 782 #endif 783 784 struct pr_usrreqs div_usrreqs = { 785 .pru_attach = div_attach, 786 .pru_bind = div_bind, 787 .pru_control = in_control, 788 .pru_detach = div_detach, 789 .pru_peeraddr = in_getpeeraddr, 790 .pru_send = div_send, 791 .pru_shutdown = div_shutdown, 792 .pru_sockaddr = in_getsockaddr, 793 .pru_sosetlabel = in_pcbsosetlabel 794 }; 795 796 struct protosw div_protosw = { 797 .pr_type = SOCK_RAW, 798 .pr_protocol = IPPROTO_DIVERT, 799 .pr_flags = PR_ATOMIC|PR_ADDR, 800 .pr_input = div_input, 801 .pr_init = div_init, 802 .pr_usrreqs = &div_usrreqs 803 }; 804 805 static int 806 div_modevent(module_t mod, int type, void *unused) 807 { 808 int err = 0; 809 810 switch (type) { 811 case MOD_LOAD: 812 /* 813 * Protocol will be initialized by pf_proto_register(). 814 * We don't have to register ip_protox because we are not 815 * a true IP protocol that goes over the wire. 816 */ 817 err = pf_proto_register(PF_INET, &div_protosw); 818 if (err != 0) 819 return (err); 820 ip_divert_ptr = divert_packet; 821 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 822 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 823 break; 824 case MOD_QUIESCE: 825 /* 826 * IPDIVERT may normally not be unloaded because of the 827 * potential race conditions. Tell kldunload we can't be 828 * unloaded unless the unload is forced. 829 */ 830 err = EPERM; 831 break; 832 case MOD_UNLOAD: 833 /* 834 * Forced unload. 835 * 836 * Module ipdivert can only be unloaded if no sockets are 837 * connected. Maybe this can be changed later to forcefully 838 * disconnect any open sockets. 839 * 840 * XXXRW: Note that there is a slight race here, as a new 841 * socket open request could be spinning on the lock and then 842 * we destroy the lock. 843 */ 844 INP_INFO_WLOCK(&V_divcbinfo); 845 if (V_divcbinfo.ipi_count != 0) { 846 err = EBUSY; 847 INP_INFO_WUNLOCK(&V_divcbinfo); 848 break; 849 } 850 ip_divert_ptr = NULL; 851 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 852 INP_INFO_WUNLOCK(&V_divcbinfo); 853 #ifndef VIMAGE 854 div_destroy(NULL); 855 #endif 856 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 857 break; 858 default: 859 err = EOPNOTSUPP; 860 break; 861 } 862 return err; 863 } 864 865 static moduledata_t ipdivertmod = { 866 "ipdivert", 867 div_modevent, 868 0 869 }; 870 871 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 872 MODULE_DEPEND(ipdivert, ipfw, 3, 3, 3); 873 MODULE_VERSION(ipdivert, 1); 874