1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_inet.h" 34 #include "opt_inet6.h" 35 #include "opt_sctp.h" 36 #ifndef INET 37 #error "IPDIVERT requires INET" 38 #endif 39 40 #include <sys/param.h> 41 #include <sys/eventhandler.h> 42 #include <sys/kernel.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/mbuf.h> 46 #include <sys/module.h> 47 #include <sys/kernel.h> 48 #include <sys/priv.h> 49 #include <sys/proc.h> 50 #include <sys/protosw.h> 51 #include <sys/socket.h> 52 #include <sys/socketvar.h> 53 #include <sys/sysctl.h> 54 #include <net/vnet.h> 55 56 #include <net/if.h> 57 #include <net/if_var.h> 58 #include <net/netisr.h> 59 60 #include <netinet/in.h> 61 #include <netinet/in_pcb.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/in_var.h> 64 #include <netinet/ip.h> 65 #include <netinet/ip_var.h> 66 #ifdef INET6 67 #include <netinet/ip6.h> 68 #include <netinet6/ip6_var.h> 69 #endif 70 #ifdef SCTP 71 #include <netinet/sctp_crc32.h> 72 #endif 73 74 #include <security/mac/mac_framework.h> 75 76 /* 77 * Divert sockets 78 */ 79 80 /* 81 * Allocate enough space to hold a full IP packet 82 */ 83 #define DIVSNDQ (65536 + 100) 84 #define DIVRCVQ (65536 + 100) 85 86 /* 87 * Divert sockets work in conjunction with ipfw or other packet filters, 88 * see the divert(4) manpage for features. 89 * Packets are selected by the packet filter and tagged with an 90 * MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by 91 * the packet filter) and information on the matching filter rule for 92 * subsequent reinjection. The divert_port is used to put the packet 93 * on the corresponding divert socket, while the rule number is passed 94 * up (at least partially) as the sin_port in the struct sockaddr. 95 * 96 * Packets written to the divert socket carry in sin_addr a 97 * destination address, and in sin_port the number of the filter rule 98 * after which to continue processing. 99 * If the destination address is INADDR_ANY, the packet is treated as 100 * as outgoing and sent to ip_output(); otherwise it is treated as 101 * incoming and sent to ip_input(). 102 * Further, sin_zero carries some information on the interface, 103 * which can be used in the reinject -- see comments in the code. 104 * 105 * On reinjection, processing in ip_input() and ip_output() 106 * will be exactly the same as for the original packet, except that 107 * packet filter processing will start at the rule number after the one 108 * written in the sin_port (ipfw does not allow a rule #0, so sin_port=0 109 * will apply the entire ruleset to the packet). 110 */ 111 112 /* Internal variables. */ 113 static VNET_DEFINE(struct inpcbhead, divcb); 114 static VNET_DEFINE(struct inpcbinfo, divcbinfo); 115 116 #define V_divcb VNET(divcb) 117 #define V_divcbinfo VNET(divcbinfo) 118 119 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 120 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 121 122 static eventhandler_tag ip_divert_event_tag; 123 124 /* 125 * Initialize divert connection block queue. 126 */ 127 static void 128 div_zone_change(void *tag) 129 { 130 131 uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets); 132 } 133 134 static int 135 div_inpcb_init(void *mem, int size, int flags) 136 { 137 struct inpcb *inp = mem; 138 139 INP_LOCK_INIT(inp, "inp", "divinp"); 140 return (0); 141 } 142 143 static void 144 div_inpcb_fini(void *mem, int size) 145 { 146 struct inpcb *inp = mem; 147 148 INP_LOCK_DESTROY(inp); 149 } 150 151 static void 152 div_init(void) 153 { 154 155 /* 156 * XXX We don't use the hash list for divert IP, but it's easier to 157 * allocate one-entry hash lists than it is to check all over the 158 * place for hashbase == NULL. 159 */ 160 in_pcbinfo_init(&V_divcbinfo, "div", &V_divcb, 1, 1, "divcb", 161 div_inpcb_init, div_inpcb_fini, 0, IPI_HASHFIELDS_NONE); 162 } 163 164 static void 165 div_destroy(void *unused __unused) 166 { 167 168 in_pcbinfo_destroy(&V_divcbinfo); 169 } 170 VNET_SYSUNINIT(divert, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, 171 div_destroy, NULL); 172 173 /* 174 * IPPROTO_DIVERT is not in the real IP protocol number space; this 175 * function should never be called. Just in case, drop any packets. 176 */ 177 static int 178 div_input(struct mbuf **mp, int *offp, int proto) 179 { 180 struct mbuf *m = *mp; 181 182 KMOD_IPSTAT_INC(ips_noproto); 183 m_freem(m); 184 return (IPPROTO_DONE); 185 } 186 187 /* 188 * Divert a packet by passing it up to the divert socket at port 'port'. 189 * 190 * Setup generic address and protocol structures for div_input routine, 191 * then pass them along with mbuf chain. 192 */ 193 static void 194 divert_packet(struct mbuf *m, int incoming) 195 { 196 struct ip *ip; 197 struct inpcb *inp; 198 struct socket *sa; 199 u_int16_t nport; 200 struct sockaddr_in divsrc; 201 struct m_tag *mtag; 202 203 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 204 if (mtag == NULL) { 205 m_freem(m); 206 return; 207 } 208 /* Assure header */ 209 if (m->m_len < sizeof(struct ip) && 210 (m = m_pullup(m, sizeof(struct ip))) == NULL) 211 return; 212 ip = mtod(m, struct ip *); 213 214 /* Delayed checksums are currently not compatible with divert. */ 215 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 216 in_delayed_cksum(m); 217 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 218 } 219 #ifdef SCTP 220 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 221 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 222 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 223 } 224 #endif 225 bzero(&divsrc, sizeof(divsrc)); 226 divsrc.sin_len = sizeof(divsrc); 227 divsrc.sin_family = AF_INET; 228 /* record matching rule, in host format */ 229 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 230 /* 231 * Record receive interface address, if any. 232 * But only for incoming packets. 233 */ 234 if (incoming) { 235 struct ifaddr *ifa; 236 struct ifnet *ifp; 237 238 /* Sanity check */ 239 M_ASSERTPKTHDR(m); 240 241 /* Find IP address for receive interface */ 242 ifp = m->m_pkthdr.rcvif; 243 if_addr_rlock(ifp); 244 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 245 if (ifa->ifa_addr->sa_family != AF_INET) 246 continue; 247 divsrc.sin_addr = 248 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 249 break; 250 } 251 if_addr_runlock(ifp); 252 } 253 /* 254 * Record the incoming interface name whenever we have one. 255 */ 256 if (m->m_pkthdr.rcvif) { 257 /* 258 * Hide the actual interface name in there in the 259 * sin_zero array. XXX This needs to be moved to a 260 * different sockaddr type for divert, e.g. 261 * sockaddr_div with multiple fields like 262 * sockaddr_dl. Presently we have only 7 bytes 263 * but that will do for now as most interfaces 264 * are 4 or less + 2 or less bytes for unit. 265 * There is probably a faster way of doing this, 266 * possibly taking it from the sockaddr_dl on the iface. 267 * This solves the problem of a P2P link and a LAN interface 268 * having the same address, which can result in the wrong 269 * interface being assigned to the packet when fed back 270 * into the divert socket. Theoretically if the daemon saves 271 * and re-uses the sockaddr_in as suggested in the man pages, 272 * this iface name will come along for the ride. 273 * (see div_output for the other half of this.) 274 */ 275 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 276 sizeof(divsrc.sin_zero)); 277 } 278 279 /* Put packet on socket queue, if any */ 280 sa = NULL; 281 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 282 INP_INFO_RLOCK(&V_divcbinfo); 283 LIST_FOREACH(inp, &V_divcb, inp_list) { 284 /* XXX why does only one socket match? */ 285 if (inp->inp_lport == nport) { 286 INP_RLOCK(inp); 287 sa = inp->inp_socket; 288 SOCKBUF_LOCK(&sa->so_rcv); 289 if (sbappendaddr_locked(&sa->so_rcv, 290 (struct sockaddr *)&divsrc, m, 291 (struct mbuf *)0) == 0) { 292 SOCKBUF_UNLOCK(&sa->so_rcv); 293 sa = NULL; /* force mbuf reclaim below */ 294 } else 295 sorwakeup_locked(sa); 296 INP_RUNLOCK(inp); 297 break; 298 } 299 } 300 INP_INFO_RUNLOCK(&V_divcbinfo); 301 if (sa == NULL) { 302 m_freem(m); 303 KMOD_IPSTAT_INC(ips_noproto); 304 KMOD_IPSTAT_DEC(ips_delivered); 305 } 306 } 307 308 /* 309 * Deliver packet back into the IP processing machinery. 310 * 311 * If no address specified, or address is 0.0.0.0, send to ip_output(); 312 * otherwise, send to ip_input() and mark as having been received on 313 * the interface with that address. 314 */ 315 static int 316 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 317 struct mbuf *control) 318 { 319 struct ip *const ip = mtod(m, struct ip *); 320 struct m_tag *mtag; 321 struct ipfw_rule_ref *dt; 322 int error = 0; 323 324 /* 325 * An mbuf may hasn't come from userland, but we pretend 326 * that it has. 327 */ 328 m->m_pkthdr.rcvif = NULL; 329 m->m_nextpkt = NULL; 330 M_SETFIB(m, so->so_fibnum); 331 332 if (control) 333 m_freem(control); /* XXX */ 334 335 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 336 if (mtag == NULL) { 337 /* this should be normal */ 338 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 339 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 340 if (mtag == NULL) { 341 error = ENOBUFS; 342 goto cantsend; 343 } 344 m_tag_prepend(m, mtag); 345 } 346 dt = (struct ipfw_rule_ref *)(mtag+1); 347 348 /* Loopback avoidance and state recovery */ 349 if (sin) { 350 int i; 351 352 /* set the starting point. We provide a non-zero slot, 353 * but a non_matching chain_id to skip that info and use 354 * the rulenum/rule_id. 355 */ 356 dt->slot = 1; /* dummy, chain_id is invalid */ 357 dt->chain_id = 0; 358 dt->rulenum = sin->sin_port+1; /* host format ? */ 359 dt->rule_id = 0; 360 /* 361 * Find receive interface with the given name, stuffed 362 * (if it exists) in the sin_zero[] field. 363 * The name is user supplied data so don't trust its size 364 * or that it is zero terminated. 365 */ 366 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 367 ; 368 if ( i > 0 && i < sizeof(sin->sin_zero)) 369 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 370 } 371 372 /* Reinject packet into the system as incoming or outgoing */ 373 if (!sin || sin->sin_addr.s_addr == 0) { 374 struct mbuf *options = NULL; 375 struct inpcb *inp; 376 377 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 378 inp = sotoinpcb(so); 379 INP_RLOCK(inp); 380 switch (ip->ip_v) { 381 case IPVERSION: 382 /* 383 * Don't allow both user specified and setsockopt 384 * options, and don't allow packet length sizes that 385 * will crash. 386 */ 387 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 388 inp->inp_options != NULL) || 389 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 390 error = EINVAL; 391 INP_RUNLOCK(inp); 392 goto cantsend; 393 } 394 break; 395 #ifdef INET6 396 case IPV6_VERSION >> 4: 397 { 398 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 399 400 /* Don't allow packet length sizes that will crash */ 401 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 402 error = EINVAL; 403 INP_RUNLOCK(inp); 404 goto cantsend; 405 } 406 break; 407 } 408 #endif 409 default: 410 error = EINVAL; 411 INP_RUNLOCK(inp); 412 goto cantsend; 413 } 414 415 /* Send packet to output processing */ 416 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 417 418 #ifdef MAC 419 mac_inpcb_create_mbuf(inp, m); 420 #endif 421 /* 422 * Get ready to inject the packet into ip_output(). 423 * Just in case socket options were specified on the 424 * divert socket, we duplicate them. This is done 425 * to avoid having to hold the PCB locks over the call 426 * to ip_output(), as doing this results in a number of 427 * lock ordering complexities. 428 * 429 * Note that we set the multicast options argument for 430 * ip_output() to NULL since it should be invariant that 431 * they are not present. 432 */ 433 KASSERT(inp->inp_moptions == NULL, 434 ("multicast options set on a divert socket")); 435 /* 436 * XXXCSJP: It is unclear to me whether or not it makes 437 * sense for divert sockets to have options. However, 438 * for now we will duplicate them with the INP locks 439 * held so we can use them in ip_output() without 440 * requring a reference to the pcb. 441 */ 442 if (inp->inp_options != NULL) { 443 options = m_dup(inp->inp_options, M_NOWAIT); 444 if (options == NULL) { 445 INP_RUNLOCK(inp); 446 error = ENOBUFS; 447 goto cantsend; 448 } 449 } 450 INP_RUNLOCK(inp); 451 452 switch (ip->ip_v) { 453 case IPVERSION: 454 error = ip_output(m, options, NULL, 455 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 456 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 457 break; 458 #ifdef INET6 459 case IPV6_VERSION >> 4: 460 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 461 break; 462 #endif 463 } 464 if (options != NULL) 465 m_freem(options); 466 } else { 467 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 468 if (m->m_pkthdr.rcvif == NULL) { 469 /* 470 * No luck with the name, check by IP address. 471 * Clear the port and the ifname to make sure 472 * there are no distractions for ifa_ifwithaddr. 473 */ 474 struct ifaddr *ifa; 475 476 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 477 sin->sin_port = 0; 478 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 479 if (ifa == NULL) { 480 error = EADDRNOTAVAIL; 481 goto cantsend; 482 } 483 m->m_pkthdr.rcvif = ifa->ifa_ifp; 484 ifa_free(ifa); 485 } 486 #ifdef MAC 487 mac_socket_create_mbuf(so, m); 488 #endif 489 /* Send packet to input processing via netisr */ 490 switch (ip->ip_v) { 491 case IPVERSION: 492 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 493 break; 494 #ifdef INET6 495 case IPV6_VERSION >> 4: 496 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 497 break; 498 #endif 499 default: 500 error = EINVAL; 501 goto cantsend; 502 } 503 } 504 505 return (error); 506 507 cantsend: 508 m_freem(m); 509 return (error); 510 } 511 512 static int 513 div_attach(struct socket *so, int proto, struct thread *td) 514 { 515 struct inpcb *inp; 516 int error; 517 518 inp = sotoinpcb(so); 519 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 520 if (td != NULL) { 521 error = priv_check(td, PRIV_NETINET_DIVERT); 522 if (error) 523 return (error); 524 } 525 error = soreserve(so, div_sendspace, div_recvspace); 526 if (error) 527 return error; 528 INP_INFO_WLOCK(&V_divcbinfo); 529 error = in_pcballoc(so, &V_divcbinfo); 530 if (error) { 531 INP_INFO_WUNLOCK(&V_divcbinfo); 532 return error; 533 } 534 inp = (struct inpcb *)so->so_pcb; 535 INP_INFO_WUNLOCK(&V_divcbinfo); 536 inp->inp_ip_p = proto; 537 inp->inp_vflag |= INP_IPV4; 538 inp->inp_flags |= INP_HDRINCL; 539 INP_WUNLOCK(inp); 540 return 0; 541 } 542 543 static void 544 div_detach(struct socket *so) 545 { 546 struct inpcb *inp; 547 548 inp = sotoinpcb(so); 549 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 550 INP_INFO_WLOCK(&V_divcbinfo); 551 INP_WLOCK(inp); 552 in_pcbdetach(inp); 553 in_pcbfree(inp); 554 INP_INFO_WUNLOCK(&V_divcbinfo); 555 } 556 557 static int 558 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 559 { 560 struct inpcb *inp; 561 int error; 562 563 inp = sotoinpcb(so); 564 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 565 /* in_pcbbind assumes that nam is a sockaddr_in 566 * and in_pcbbind requires a valid address. Since divert 567 * sockets don't we need to make sure the address is 568 * filled in properly. 569 * XXX -- divert should not be abusing in_pcbind 570 * and should probably have its own family. 571 */ 572 if (nam->sa_family != AF_INET) 573 return EAFNOSUPPORT; 574 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 575 INP_INFO_WLOCK(&V_divcbinfo); 576 INP_WLOCK(inp); 577 INP_HASH_WLOCK(&V_divcbinfo); 578 error = in_pcbbind(inp, nam, td->td_ucred); 579 INP_HASH_WUNLOCK(&V_divcbinfo); 580 INP_WUNLOCK(inp); 581 INP_INFO_WUNLOCK(&V_divcbinfo); 582 return error; 583 } 584 585 static int 586 div_shutdown(struct socket *so) 587 { 588 struct inpcb *inp; 589 590 inp = sotoinpcb(so); 591 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 592 INP_WLOCK(inp); 593 socantsendmore(so); 594 INP_WUNLOCK(inp); 595 return 0; 596 } 597 598 static int 599 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 600 struct mbuf *control, struct thread *td) 601 { 602 603 /* Packet must have a header (but that's about it) */ 604 if (m->m_len < sizeof (struct ip) && 605 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 606 KMOD_IPSTAT_INC(ips_toosmall); 607 m_freem(m); 608 return EINVAL; 609 } 610 611 /* Send packet */ 612 return div_output(so, m, (struct sockaddr_in *)nam, control); 613 } 614 615 static void 616 div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 617 { 618 struct in_addr faddr; 619 620 faddr = ((struct sockaddr_in *)sa)->sin_addr; 621 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 622 return; 623 if (PRC_IS_REDIRECT(cmd)) 624 return; 625 } 626 627 static int 628 div_pcblist(SYSCTL_HANDLER_ARGS) 629 { 630 int error, i, n; 631 struct inpcb *inp, **inp_list; 632 inp_gen_t gencnt; 633 struct xinpgen xig; 634 635 /* 636 * The process of preparing the TCB list is too time-consuming and 637 * resource-intensive to repeat twice on every request. 638 */ 639 if (req->oldptr == 0) { 640 n = V_divcbinfo.ipi_count; 641 n += imax(n / 8, 10); 642 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 643 return 0; 644 } 645 646 if (req->newptr != 0) 647 return EPERM; 648 649 /* 650 * OK, now we're committed to doing something. 651 */ 652 INP_INFO_RLOCK(&V_divcbinfo); 653 gencnt = V_divcbinfo.ipi_gencnt; 654 n = V_divcbinfo.ipi_count; 655 INP_INFO_RUNLOCK(&V_divcbinfo); 656 657 error = sysctl_wire_old_buffer(req, 658 2 * sizeof(xig) + n*sizeof(struct xinpcb)); 659 if (error != 0) 660 return (error); 661 662 xig.xig_len = sizeof xig; 663 xig.xig_count = n; 664 xig.xig_gen = gencnt; 665 xig.xig_sogen = so_gencnt; 666 error = SYSCTL_OUT(req, &xig, sizeof xig); 667 if (error) 668 return error; 669 670 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 671 if (inp_list == NULL) 672 return ENOMEM; 673 674 INP_INFO_RLOCK(&V_divcbinfo); 675 for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n; 676 inp = LIST_NEXT(inp, inp_list)) { 677 INP_WLOCK(inp); 678 if (inp->inp_gencnt <= gencnt && 679 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 680 in_pcbref(inp); 681 inp_list[i++] = inp; 682 } 683 INP_WUNLOCK(inp); 684 } 685 INP_INFO_RUNLOCK(&V_divcbinfo); 686 n = i; 687 688 error = 0; 689 for (i = 0; i < n; i++) { 690 inp = inp_list[i]; 691 INP_RLOCK(inp); 692 if (inp->inp_gencnt <= gencnt) { 693 struct xinpcb xi; 694 bzero(&xi, sizeof(xi)); 695 xi.xi_len = sizeof xi; 696 /* XXX should avoid extra copy */ 697 bcopy(inp, &xi.xi_inp, sizeof *inp); 698 if (inp->inp_socket) 699 sotoxsocket(inp->inp_socket, &xi.xi_socket); 700 INP_RUNLOCK(inp); 701 error = SYSCTL_OUT(req, &xi, sizeof xi); 702 } else 703 INP_RUNLOCK(inp); 704 } 705 INP_INFO_WLOCK(&V_divcbinfo); 706 for (i = 0; i < n; i++) { 707 inp = inp_list[i]; 708 INP_RLOCK(inp); 709 if (!in_pcbrele_rlocked(inp)) 710 INP_RUNLOCK(inp); 711 } 712 INP_INFO_WUNLOCK(&V_divcbinfo); 713 714 if (!error) { 715 /* 716 * Give the user an updated idea of our state. 717 * If the generation differs from what we told 718 * her before, she knows that something happened 719 * while we were processing this request, and it 720 * might be necessary to retry. 721 */ 722 INP_INFO_RLOCK(&V_divcbinfo); 723 xig.xig_gen = V_divcbinfo.ipi_gencnt; 724 xig.xig_sogen = so_gencnt; 725 xig.xig_count = V_divcbinfo.ipi_count; 726 INP_INFO_RUNLOCK(&V_divcbinfo); 727 error = SYSCTL_OUT(req, &xig, sizeof xig); 728 } 729 free(inp_list, M_TEMP); 730 return error; 731 } 732 733 #ifdef SYSCTL_NODE 734 static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, 735 "IPDIVERT"); 736 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 737 NULL, 0, div_pcblist, "S,xinpcb", "List of active divert sockets"); 738 #endif 739 740 struct pr_usrreqs div_usrreqs = { 741 .pru_attach = div_attach, 742 .pru_bind = div_bind, 743 .pru_control = in_control, 744 .pru_detach = div_detach, 745 .pru_peeraddr = in_getpeeraddr, 746 .pru_send = div_send, 747 .pru_shutdown = div_shutdown, 748 .pru_sockaddr = in_getsockaddr, 749 .pru_sosetlabel = in_pcbsosetlabel 750 }; 751 752 struct protosw div_protosw = { 753 .pr_type = SOCK_RAW, 754 .pr_protocol = IPPROTO_DIVERT, 755 .pr_flags = PR_ATOMIC|PR_ADDR, 756 .pr_input = div_input, 757 .pr_ctlinput = div_ctlinput, 758 .pr_ctloutput = ip_ctloutput, 759 .pr_init = div_init, 760 .pr_usrreqs = &div_usrreqs 761 }; 762 763 static int 764 div_modevent(module_t mod, int type, void *unused) 765 { 766 int err = 0; 767 768 switch (type) { 769 case MOD_LOAD: 770 /* 771 * Protocol will be initialized by pf_proto_register(). 772 * We don't have to register ip_protox because we are not 773 * a true IP protocol that goes over the wire. 774 */ 775 err = pf_proto_register(PF_INET, &div_protosw); 776 if (err != 0) 777 return (err); 778 ip_divert_ptr = divert_packet; 779 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 780 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 781 break; 782 case MOD_QUIESCE: 783 /* 784 * IPDIVERT may normally not be unloaded because of the 785 * potential race conditions. Tell kldunload we can't be 786 * unloaded unless the unload is forced. 787 */ 788 err = EPERM; 789 break; 790 case MOD_UNLOAD: 791 /* 792 * Forced unload. 793 * 794 * Module ipdivert can only be unloaded if no sockets are 795 * connected. Maybe this can be changed later to forcefully 796 * disconnect any open sockets. 797 * 798 * XXXRW: Note that there is a slight race here, as a new 799 * socket open request could be spinning on the lock and then 800 * we destroy the lock. 801 */ 802 INP_INFO_WLOCK(&V_divcbinfo); 803 if (V_divcbinfo.ipi_count != 0) { 804 err = EBUSY; 805 INP_INFO_WUNLOCK(&V_divcbinfo); 806 break; 807 } 808 ip_divert_ptr = NULL; 809 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 810 INP_INFO_WUNLOCK(&V_divcbinfo); 811 #ifndef VIMAGE 812 div_destroy(NULL); 813 #endif 814 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 815 break; 816 default: 817 err = EOPNOTSUPP; 818 break; 819 } 820 return err; 821 } 822 823 static moduledata_t ipdivertmod = { 824 "ipdivert", 825 div_modevent, 826 0 827 }; 828 829 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 830 MODULE_DEPEND(ipdivert, ipfw, 3, 3, 3); 831 MODULE_VERSION(ipdivert, 1); 832