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 #ifdef SCTP 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 in_delayed_cksum(m); 216 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 217 } 218 #ifdef SCTP 219 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 220 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 221 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 222 } 223 #endif 224 bzero(&divsrc, sizeof(divsrc)); 225 divsrc.sin_len = sizeof(divsrc); 226 divsrc.sin_family = AF_INET; 227 /* record matching rule, in host format */ 228 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 229 /* 230 * Record receive interface address, if any. 231 * But only for incoming packets. 232 */ 233 if (incoming) { 234 struct ifaddr *ifa; 235 struct ifnet *ifp; 236 237 /* Sanity check */ 238 M_ASSERTPKTHDR(m); 239 240 /* Find IP address for receive interface */ 241 ifp = m->m_pkthdr.rcvif; 242 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 243 if (ifa->ifa_addr->sa_family != AF_INET) 244 continue; 245 divsrc.sin_addr = 246 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 247 break; 248 } 249 } 250 /* 251 * Record the incoming interface name whenever we have one. 252 */ 253 if (m->m_pkthdr.rcvif) { 254 /* 255 * Hide the actual interface name in there in the 256 * sin_zero array. XXX This needs to be moved to a 257 * different sockaddr type for divert, e.g. 258 * sockaddr_div with multiple fields like 259 * sockaddr_dl. Presently we have only 7 bytes 260 * but that will do for now as most interfaces 261 * are 4 or less + 2 or less bytes for unit. 262 * There is probably a faster way of doing this, 263 * possibly taking it from the sockaddr_dl on the iface. 264 * This solves the problem of a P2P link and a LAN interface 265 * having the same address, which can result in the wrong 266 * interface being assigned to the packet when fed back 267 * into the divert socket. Theoretically if the daemon saves 268 * and re-uses the sockaddr_in as suggested in the man pages, 269 * this iface name will come along for the ride. 270 * (see div_output for the other half of this.) 271 */ 272 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 273 sizeof(divsrc.sin_zero)); 274 } 275 276 /* Put packet on socket queue, if any */ 277 sa = NULL; 278 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 279 CK_LIST_FOREACH(inp, &V_divcb, inp_list) { 280 /* XXX why does only one socket match? */ 281 if (inp->inp_lport == nport) { 282 INP_RLOCK(inp); 283 sa = inp->inp_socket; 284 SOCKBUF_LOCK(&sa->so_rcv); 285 if (sbappendaddr_locked(&sa->so_rcv, 286 (struct sockaddr *)&divsrc, m, 287 (struct mbuf *)0) == 0) { 288 SOCKBUF_UNLOCK(&sa->so_rcv); 289 sa = NULL; /* force mbuf reclaim below */ 290 } else 291 sorwakeup_locked(sa); 292 INP_RUNLOCK(inp); 293 break; 294 } 295 } 296 if (sa == NULL) { 297 m_freem(m); 298 KMOD_IPSTAT_INC(ips_noproto); 299 KMOD_IPSTAT_DEC(ips_delivered); 300 } 301 } 302 303 /* 304 * Deliver packet back into the IP processing machinery. 305 * 306 * If no address specified, or address is 0.0.0.0, send to ip_output(); 307 * otherwise, send to ip_input() and mark as having been received on 308 * the interface with that address. 309 */ 310 static int 311 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 312 struct mbuf *control) 313 { 314 struct epoch_tracker et; 315 const struct ip *ip; 316 struct m_tag *mtag; 317 struct ipfw_rule_ref *dt; 318 int error, family; 319 320 /* 321 * An mbuf may hasn't come from userland, but we pretend 322 * that it has. 323 */ 324 m->m_pkthdr.rcvif = NULL; 325 m->m_nextpkt = NULL; 326 M_SETFIB(m, so->so_fibnum); 327 328 if (control) 329 m_freem(control); /* XXX */ 330 331 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 332 if (mtag == NULL) { 333 /* this should be normal */ 334 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 335 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 336 if (mtag == NULL) { 337 m_freem(m); 338 return (ENOBUFS); 339 } 340 m_tag_prepend(m, mtag); 341 } 342 dt = (struct ipfw_rule_ref *)(mtag+1); 343 344 /* Loopback avoidance and state recovery */ 345 if (sin) { 346 int i; 347 348 /* set the starting point. We provide a non-zero slot, 349 * but a non_matching chain_id to skip that info and use 350 * the rulenum/rule_id. 351 */ 352 dt->slot = 1; /* dummy, chain_id is invalid */ 353 dt->chain_id = 0; 354 dt->rulenum = sin->sin_port+1; /* host format ? */ 355 dt->rule_id = 0; 356 /* XXX: broken for IPv6 */ 357 /* 358 * Find receive interface with the given name, stuffed 359 * (if it exists) in the sin_zero[] field. 360 * The name is user supplied data so don't trust its size 361 * or that it is zero terminated. 362 */ 363 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 364 ; 365 if ( i > 0 && i < sizeof(sin->sin_zero)) 366 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 367 } 368 369 ip = mtod(m, struct ip *); 370 switch (ip->ip_v) { 371 case IPVERSION: 372 family = AF_INET; 373 break; 374 #ifdef INET6 375 case IPV6_VERSION >> 4: 376 family = AF_INET6; 377 break; 378 #endif 379 default: 380 m_freem(m); 381 return (EAFNOSUPPORT); 382 } 383 384 /* Reinject packet into the system as incoming or outgoing */ 385 NET_EPOCH_ENTER(et); 386 if (!sin || sin->sin_addr.s_addr == 0) { 387 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 388 error = div_output_outbound(family, so, m); 389 } else { 390 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 391 error = div_output_inbound(family, so, m, sin); 392 } 393 NET_EPOCH_EXIT(et); 394 395 if (error != 0) 396 m_freem(m); 397 398 return (error); 399 } 400 401 /* 402 * Sends mbuf @m to the wire via ip[6]_output(). 403 * 404 * Returns 0 on success, @m is consumed. 405 * On failure, returns error code. It is caller responsibility to free @m. 406 */ 407 static int 408 div_output_outbound(int family, struct socket *so, struct mbuf *m) 409 { 410 struct ip *const ip = mtod(m, struct ip *); 411 struct mbuf *options; 412 struct inpcb *inp; 413 int error; 414 415 inp = sotoinpcb(so); 416 INP_RLOCK(inp); 417 switch (family) { 418 case AF_INET: 419 /* 420 * Don't allow both user specified and setsockopt 421 * options, and don't allow packet length sizes that 422 * will crash. 423 */ 424 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 425 inp->inp_options != NULL) || 426 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 427 INP_RUNLOCK(inp); 428 return (EINVAL); 429 } 430 break; 431 #ifdef INET6 432 case AF_INET6: 433 { 434 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 435 436 /* Don't allow packet length sizes that will crash */ 437 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 438 INP_RUNLOCK(inp); 439 return (EINVAL); 440 } 441 break; 442 } 443 #endif 444 } 445 446 /* Send packet to output processing */ 447 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 448 449 #ifdef MAC 450 mac_inpcb_create_mbuf(inp, m); 451 #endif 452 /* 453 * Get ready to inject the packet into ip_output(). 454 * Just in case socket options were specified on the 455 * divert socket, we duplicate them. This is done 456 * to avoid having to hold the PCB locks over the call 457 * to ip_output(), as doing this results in a number of 458 * lock ordering complexities. 459 * 460 * Note that we set the multicast options argument for 461 * ip_output() to NULL since it should be invariant that 462 * they are not present. 463 */ 464 KASSERT(inp->inp_moptions == NULL, 465 ("multicast options set on a divert socket")); 466 /* 467 * XXXCSJP: It is unclear to me whether or not it makes 468 * sense for divert sockets to have options. However, 469 * for now we will duplicate them with the INP locks 470 * held so we can use them in ip_output() without 471 * requring a reference to the pcb. 472 */ 473 options = NULL; 474 if (inp->inp_options != NULL) { 475 options = m_dup(inp->inp_options, M_NOWAIT); 476 if (options == NULL) { 477 INP_RUNLOCK(inp); 478 return (ENOBUFS); 479 } 480 } 481 INP_RUNLOCK(inp); 482 483 error = 0; 484 switch (family) { 485 case AF_INET: 486 error = ip_output(m, options, NULL, 487 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 488 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 489 break; 490 #ifdef INET6 491 case AF_INET6: 492 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 493 break; 494 #endif 495 } 496 if (options != NULL) 497 m_freem(options); 498 499 return (error); 500 } 501 502 /* 503 * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue. 504 * 505 * Returns 0 on success, @m is consumed. 506 * Returns error code on failure. It is caller responsibility to free @m. 507 */ 508 static int 509 div_output_inbound(int family, struct socket *so, struct mbuf *m, 510 struct sockaddr_in *sin) 511 { 512 const struct ip *ip; 513 struct ifaddr *ifa; 514 515 if (m->m_pkthdr.rcvif == NULL) { 516 /* 517 * No luck with the name, check by IP address. 518 * Clear the port and the ifname to make sure 519 * there are no distractions for ifa_ifwithaddr. 520 */ 521 522 /* XXX: broken for IPv6 */ 523 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 524 sin->sin_port = 0; 525 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 526 if (ifa == NULL) 527 return (EADDRNOTAVAIL); 528 m->m_pkthdr.rcvif = ifa->ifa_ifp; 529 } 530 #ifdef MAC 531 mac_socket_create_mbuf(so, m); 532 #endif 533 /* Send packet to input processing via netisr */ 534 switch (family) { 535 case AF_INET: 536 ip = mtod(m, struct ip *); 537 /* 538 * Restore M_BCAST flag when destination address is 539 * broadcast. It is expected by ip_tryforward(). 540 */ 541 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) 542 m->m_flags |= M_MCAST; 543 else if (in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) 544 m->m_flags |= M_BCAST; 545 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 546 break; 547 #ifdef INET6 548 case AF_INET6: 549 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 550 break; 551 #endif 552 default: 553 return (EINVAL); 554 } 555 556 return (0); 557 } 558 559 static int 560 div_attach(struct socket *so, int proto, struct thread *td) 561 { 562 struct inpcb *inp; 563 int error; 564 565 inp = sotoinpcb(so); 566 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 567 if (td != NULL) { 568 error = priv_check(td, PRIV_NETINET_DIVERT); 569 if (error) 570 return (error); 571 } 572 error = soreserve(so, div_sendspace, div_recvspace); 573 if (error) 574 return error; 575 INP_INFO_WLOCK(&V_divcbinfo); 576 error = in_pcballoc(so, &V_divcbinfo); 577 if (error) { 578 INP_INFO_WUNLOCK(&V_divcbinfo); 579 return error; 580 } 581 inp = (struct inpcb *)so->so_pcb; 582 INP_INFO_WUNLOCK(&V_divcbinfo); 583 inp->inp_ip_p = proto; 584 inp->inp_vflag |= INP_IPV4; 585 inp->inp_flags |= INP_HDRINCL; 586 INP_WUNLOCK(inp); 587 return 0; 588 } 589 590 static void 591 div_detach(struct socket *so) 592 { 593 struct inpcb *inp; 594 595 inp = sotoinpcb(so); 596 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 597 INP_INFO_WLOCK(&V_divcbinfo); 598 INP_WLOCK(inp); 599 in_pcbdetach(inp); 600 in_pcbfree(inp); 601 INP_INFO_WUNLOCK(&V_divcbinfo); 602 } 603 604 static int 605 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 606 { 607 struct inpcb *inp; 608 int error; 609 610 inp = sotoinpcb(so); 611 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 612 /* in_pcbbind assumes that nam is a sockaddr_in 613 * and in_pcbbind requires a valid address. Since divert 614 * sockets don't we need to make sure the address is 615 * filled in properly. 616 * XXX -- divert should not be abusing in_pcbind 617 * and should probably have its own family. 618 */ 619 if (nam->sa_family != AF_INET) 620 return EAFNOSUPPORT; 621 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 622 INP_INFO_WLOCK(&V_divcbinfo); 623 INP_WLOCK(inp); 624 INP_HASH_WLOCK(&V_divcbinfo); 625 error = in_pcbbind(inp, nam, td->td_ucred); 626 INP_HASH_WUNLOCK(&V_divcbinfo); 627 INP_WUNLOCK(inp); 628 INP_INFO_WUNLOCK(&V_divcbinfo); 629 return error; 630 } 631 632 static int 633 div_shutdown(struct socket *so) 634 { 635 struct inpcb *inp; 636 637 inp = sotoinpcb(so); 638 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 639 INP_WLOCK(inp); 640 socantsendmore(so); 641 INP_WUNLOCK(inp); 642 return 0; 643 } 644 645 static int 646 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 647 struct mbuf *control, struct thread *td) 648 { 649 650 /* Packet must have a header (but that's about it) */ 651 if (m->m_len < sizeof (struct ip) && 652 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 653 KMOD_IPSTAT_INC(ips_toosmall); 654 m_freem(m); 655 return EINVAL; 656 } 657 658 /* Send packet */ 659 return div_output(so, m, (struct sockaddr_in *)nam, control); 660 } 661 662 static void 663 div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 664 { 665 struct in_addr faddr; 666 667 faddr = ((struct sockaddr_in *)sa)->sin_addr; 668 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 669 return; 670 if (PRC_IS_REDIRECT(cmd)) 671 return; 672 } 673 674 static int 675 div_pcblist(SYSCTL_HANDLER_ARGS) 676 { 677 struct xinpgen xig; 678 struct epoch_tracker et; 679 struct inpcb *inp; 680 int error; 681 682 if (req->newptr != 0) 683 return EPERM; 684 685 if (req->oldptr == 0) { 686 int n; 687 688 n = V_divcbinfo.ipi_count; 689 n += imax(n / 8, 10); 690 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 691 return 0; 692 } 693 694 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 695 return (error); 696 697 bzero(&xig, sizeof(xig)); 698 xig.xig_len = sizeof xig; 699 xig.xig_count = V_divcbinfo.ipi_count; 700 xig.xig_gen = V_divcbinfo.ipi_gencnt; 701 xig.xig_sogen = so_gencnt; 702 error = SYSCTL_OUT(req, &xig, sizeof xig); 703 if (error) 704 return error; 705 706 NET_EPOCH_ENTER(et); 707 for (inp = CK_LIST_FIRST(V_divcbinfo.ipi_listhead); 708 inp != NULL; 709 inp = CK_LIST_NEXT(inp, inp_list)) { 710 INP_RLOCK(inp); 711 if (inp->inp_gencnt <= xig.xig_gen) { 712 struct xinpcb xi; 713 714 in_pcbtoxinpcb(inp, &xi); 715 INP_RUNLOCK(inp); 716 error = SYSCTL_OUT(req, &xi, sizeof xi); 717 } else 718 INP_RUNLOCK(inp); 719 } 720 NET_EPOCH_EXIT(et); 721 722 if (!error) { 723 /* 724 * Give the user an updated idea of our state. 725 * If the generation differs from what we told 726 * her before, she knows that something happened 727 * while we were processing this request, and it 728 * might be necessary to retry. 729 */ 730 xig.xig_gen = V_divcbinfo.ipi_gencnt; 731 xig.xig_sogen = so_gencnt; 732 xig.xig_count = V_divcbinfo.ipi_count; 733 error = SYSCTL_OUT(req, &xig, sizeof xig); 734 } 735 736 return (error); 737 } 738 739 #ifdef SYSCTL_NODE 740 static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, 741 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 742 "IPDIVERT"); 743 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, 744 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 745 NULL, 0, div_pcblist, "S,xinpcb", 746 "List of active divert sockets"); 747 #endif 748 749 struct pr_usrreqs div_usrreqs = { 750 .pru_attach = div_attach, 751 .pru_bind = div_bind, 752 .pru_control = in_control, 753 .pru_detach = div_detach, 754 .pru_peeraddr = in_getpeeraddr, 755 .pru_send = div_send, 756 .pru_shutdown = div_shutdown, 757 .pru_sockaddr = in_getsockaddr, 758 .pru_sosetlabel = in_pcbsosetlabel 759 }; 760 761 struct protosw div_protosw = { 762 .pr_type = SOCK_RAW, 763 .pr_protocol = IPPROTO_DIVERT, 764 .pr_flags = PR_ATOMIC|PR_ADDR, 765 .pr_input = div_input, 766 .pr_ctlinput = div_ctlinput, 767 .pr_ctloutput = ip_ctloutput, 768 .pr_init = div_init, 769 .pr_usrreqs = &div_usrreqs 770 }; 771 772 static int 773 div_modevent(module_t mod, int type, void *unused) 774 { 775 int err = 0; 776 777 switch (type) { 778 case MOD_LOAD: 779 /* 780 * Protocol will be initialized by pf_proto_register(). 781 * We don't have to register ip_protox because we are not 782 * a true IP protocol that goes over the wire. 783 */ 784 err = pf_proto_register(PF_INET, &div_protosw); 785 if (err != 0) 786 return (err); 787 ip_divert_ptr = divert_packet; 788 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 789 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 790 break; 791 case MOD_QUIESCE: 792 /* 793 * IPDIVERT may normally not be unloaded because of the 794 * potential race conditions. Tell kldunload we can't be 795 * unloaded unless the unload is forced. 796 */ 797 err = EPERM; 798 break; 799 case MOD_UNLOAD: 800 /* 801 * Forced unload. 802 * 803 * Module ipdivert can only be unloaded if no sockets are 804 * connected. Maybe this can be changed later to forcefully 805 * disconnect any open sockets. 806 * 807 * XXXRW: Note that there is a slight race here, as a new 808 * socket open request could be spinning on the lock and then 809 * we destroy the lock. 810 */ 811 INP_INFO_WLOCK(&V_divcbinfo); 812 if (V_divcbinfo.ipi_count != 0) { 813 err = EBUSY; 814 INP_INFO_WUNLOCK(&V_divcbinfo); 815 break; 816 } 817 ip_divert_ptr = NULL; 818 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 819 INP_INFO_WUNLOCK(&V_divcbinfo); 820 #ifndef VIMAGE 821 div_destroy(NULL); 822 #endif 823 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 824 break; 825 default: 826 err = EOPNOTSUPP; 827 break; 828 } 829 return err; 830 } 831 832 static moduledata_t ipdivertmod = { 833 "ipdivert", 834 div_modevent, 835 0 836 }; 837 838 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 839 MODULE_DEPEND(ipdivert, ipfw, 3, 3, 3); 840 MODULE_VERSION(ipdivert, 1); 841