ip_divert.c revision 241370
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: head/sys/netinet/ip_divert.c 241370 2012-10-09 08:27:40Z kevlo $"); 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/kernel.h> 42#include <sys/lock.h> 43#include <sys/malloc.h> 44#include <sys/mbuf.h> 45#include <sys/module.h> 46#include <sys/kernel.h> 47#include <sys/priv.h> 48#include <sys/proc.h> 49#include <sys/protosw.h> 50#include <sys/socket.h> 51#include <sys/socketvar.h> 52#include <sys/sysctl.h> 53#include <net/vnet.h> 54 55#include <net/if.h> 56#include <net/netisr.h> 57 58#include <netinet/in.h> 59#include <netinet/in_pcb.h> 60#include <netinet/in_systm.h> 61#include <netinet/in_var.h> 62#include <netinet/ip.h> 63#include <netinet/ip_var.h> 64#ifdef INET6 65#include <netinet/ip6.h> 66#include <netinet6/ip6_var.h> 67#endif 68#ifdef SCTP 69#include <netinet/sctp_crc32.h> 70#endif 71 72#include <security/mac/mac_framework.h> 73 74/* 75 * Divert sockets 76 */ 77 78/* 79 * Allocate enough space to hold a full IP packet 80 */ 81#define DIVSNDQ (65536 + 100) 82#define DIVRCVQ (65536 + 100) 83 84/* 85 * Divert sockets work in conjunction with ipfw or other packet filters, 86 * see the divert(4) manpage for features. 87 * Packets are selected by the packet filter and tagged with an 88 * MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by 89 * the packet filter) and information on the matching filter rule for 90 * subsequent reinjection. The divert_port is used to put the packet 91 * on the corresponding divert socket, while the rule number is passed 92 * up (at least partially) as the sin_port in the struct sockaddr. 93 * 94 * Packets written to the divert socket carry in sin_addr a 95 * destination address, and in sin_port the number of the filter rule 96 * after which to continue processing. 97 * If the destination address is INADDR_ANY, the packet is treated as 98 * as outgoing and sent to ip_output(); otherwise it is treated as 99 * incoming and sent to ip_input(). 100 * Further, sin_zero carries some information on the interface, 101 * which can be used in the reinject -- see comments in the code. 102 * 103 * On reinjection, processing in ip_input() and ip_output() 104 * will be exactly the same as for the original packet, except that 105 * packet filter processing will start at the rule number after the one 106 * written in the sin_port (ipfw does not allow a rule #0, so sin_port=0 107 * will apply the entire ruleset to the packet). 108 */ 109 110/* Internal variables. */ 111static VNET_DEFINE(struct inpcbhead, divcb); 112static VNET_DEFINE(struct inpcbinfo, divcbinfo); 113 114#define V_divcb VNET(divcb) 115#define V_divcbinfo VNET(divcbinfo) 116 117static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 118static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 119 120static eventhandler_tag ip_divert_event_tag; 121 122/* 123 * Initialize divert connection block queue. 124 */ 125static void 126div_zone_change(void *tag) 127{ 128 129 uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets); 130} 131 132static int 133div_inpcb_init(void *mem, int size, int flags) 134{ 135 struct inpcb *inp = mem; 136 137 INP_LOCK_INIT(inp, "inp", "divinp"); 138 return (0); 139} 140 141static void 142div_inpcb_fini(void *mem, int size) 143{ 144 struct inpcb *inp = mem; 145 146 INP_LOCK_DESTROY(inp); 147} 148 149static void 150div_init(void) 151{ 152 153 /* 154 * XXX We don't use the hash list for divert IP, but it's easier to 155 * allocate one-entry hash lists than it is to check all over the 156 * place for hashbase == NULL. 157 */ 158 in_pcbinfo_init(&V_divcbinfo, "div", &V_divcb, 1, 1, "divcb", 159 div_inpcb_init, div_inpcb_fini, UMA_ZONE_NOFREE, 160 IPI_HASHFIELDS_NONE); 161} 162 163static void 164div_destroy(void) 165{ 166 167 in_pcbinfo_destroy(&V_divcbinfo); 168} 169 170/* 171 * IPPROTO_DIVERT is not in the real IP protocol number space; this 172 * function should never be called. Just in case, drop any packets. 173 */ 174static void 175div_input(struct mbuf *m, int off) 176{ 177 178 KMOD_IPSTAT_INC(ips_noproto); 179 m_freem(m); 180} 181 182/* 183 * Divert a packet by passing it up to the divert socket at port 'port'. 184 * 185 * Setup generic address and protocol structures for div_input routine, 186 * then pass them along with mbuf chain. 187 */ 188static void 189divert_packet(struct mbuf *m, int incoming) 190{ 191 struct ip *ip; 192 struct inpcb *inp; 193 struct socket *sa; 194 u_int16_t nport; 195 struct sockaddr_in divsrc; 196 struct m_tag *mtag; 197 198 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 199 if (mtag == NULL) { 200 m_freem(m); 201 return; 202 } 203 /* Assure header */ 204 if (m->m_len < sizeof(struct ip) && 205 (m = m_pullup(m, sizeof(struct ip))) == 0) 206 return; 207 ip = mtod(m, struct ip *); 208 209 /* Delayed checksums are currently not compatible with divert. */ 210 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 211 in_delayed_cksum(m); 212 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 213 } 214#ifdef SCTP 215 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 216 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 217 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 218 } 219#endif 220 bzero(&divsrc, sizeof(divsrc)); 221 divsrc.sin_len = sizeof(divsrc); 222 divsrc.sin_family = AF_INET; 223 /* record matching rule, in host format */ 224 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 225 /* 226 * Record receive interface address, if any. 227 * But only for incoming packets. 228 */ 229 if (incoming) { 230 struct ifaddr *ifa; 231 struct ifnet *ifp; 232 233 /* Sanity check */ 234 M_ASSERTPKTHDR(m); 235 236 /* Find IP address for receive interface */ 237 ifp = m->m_pkthdr.rcvif; 238 if_addr_rlock(ifp); 239 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 240 if (ifa->ifa_addr->sa_family != AF_INET) 241 continue; 242 divsrc.sin_addr = 243 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 244 break; 245 } 246 if_addr_runlock(ifp); 247 } 248 /* 249 * Record the incoming interface name whenever we have one. 250 */ 251 if (m->m_pkthdr.rcvif) { 252 /* 253 * Hide the actual interface name in there in the 254 * sin_zero array. XXX This needs to be moved to a 255 * different sockaddr type for divert, e.g. 256 * sockaddr_div with multiple fields like 257 * sockaddr_dl. Presently we have only 7 bytes 258 * but that will do for now as most interfaces 259 * are 4 or less + 2 or less bytes for unit. 260 * There is probably a faster way of doing this, 261 * possibly taking it from the sockaddr_dl on the iface. 262 * This solves the problem of a P2P link and a LAN interface 263 * having the same address, which can result in the wrong 264 * interface being assigned to the packet when fed back 265 * into the divert socket. Theoretically if the daemon saves 266 * and re-uses the sockaddr_in as suggested in the man pages, 267 * this iface name will come along for the ride. 268 * (see div_output for the other half of this.) 269 */ 270 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 271 sizeof(divsrc.sin_zero)); 272 } 273 274 /* Put packet on socket queue, if any */ 275 sa = NULL; 276 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 277 INP_INFO_RLOCK(&V_divcbinfo); 278 LIST_FOREACH(inp, &V_divcb, inp_list) { 279 /* XXX why does only one socket match? */ 280 if (inp->inp_lport == nport) { 281 INP_RLOCK(inp); 282 sa = inp->inp_socket; 283 SOCKBUF_LOCK(&sa->so_rcv); 284 if (sbappendaddr_locked(&sa->so_rcv, 285 (struct sockaddr *)&divsrc, m, 286 (struct mbuf *)0) == 0) { 287 SOCKBUF_UNLOCK(&sa->so_rcv); 288 sa = NULL; /* force mbuf reclaim below */ 289 } else 290 sorwakeup_locked(sa); 291 INP_RUNLOCK(inp); 292 break; 293 } 294 } 295 INP_INFO_RUNLOCK(&V_divcbinfo); 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 */ 310static int 311div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 312 struct mbuf *control) 313{ 314 struct ip *const ip = mtod(m, struct ip *); 315 struct m_tag *mtag; 316 struct ipfw_rule_ref *dt; 317 int error = 0; 318 319 /* 320 * An mbuf may hasn't come from userland, but we pretend 321 * that it has. 322 */ 323 m->m_pkthdr.rcvif = NULL; 324 m->m_nextpkt = NULL; 325 M_SETFIB(m, so->so_fibnum); 326 327 if (control) 328 m_freem(control); /* XXX */ 329 330 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 331 if (mtag == NULL) { 332 /* this should be normal */ 333 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 334 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 335 if (mtag == NULL) { 336 error = ENOBUFS; 337 goto cantsend; 338 } 339 m_tag_prepend(m, mtag); 340 } 341 dt = (struct ipfw_rule_ref *)(mtag+1); 342 343 /* Loopback avoidance and state recovery */ 344 if (sin) { 345 int i; 346 347 /* set the starting point. We provide a non-zero slot, 348 * but a non_matching chain_id to skip that info and use 349 * the rulenum/rule_id. 350 */ 351 dt->slot = 1; /* dummy, chain_id is invalid */ 352 dt->chain_id = 0; 353 dt->rulenum = sin->sin_port+1; /* host format ? */ 354 dt->rule_id = 0; 355 /* 356 * Find receive interface with the given name, stuffed 357 * (if it exists) in the sin_zero[] field. 358 * The name is user supplied data so don't trust its size 359 * or that it is zero terminated. 360 */ 361 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 362 ; 363 if ( i > 0 && i < sizeof(sin->sin_zero)) 364 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 365 } 366 367 /* Reinject packet into the system as incoming or outgoing */ 368 if (!sin || sin->sin_addr.s_addr == 0) { 369 struct mbuf *options = NULL; 370 struct inpcb *inp; 371 372 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 373 inp = sotoinpcb(so); 374 INP_RLOCK(inp); 375 switch (ip->ip_v) { 376 case IPVERSION: 377 /* 378 * Don't allow both user specified and setsockopt 379 * options, and don't allow packet length sizes that 380 * will crash. 381 */ 382 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 383 inp->inp_options != NULL) || 384 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 385 error = EINVAL; 386 INP_RUNLOCK(inp); 387 goto cantsend; 388 } 389 390 /* Convert fields to host order for ip_output() */ 391 ip->ip_len = ntohs(ip->ip_len); 392 ip->ip_off = ntohs(ip->ip_off); 393 break; 394#ifdef INET6 395 case IPV6_VERSION >> 4: 396 { 397 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 398 399 /* Don't allow packet length sizes that will crash */ 400 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 401 error = EINVAL; 402 INP_RUNLOCK(inp); 403 goto cantsend; 404 } 405 406 ip6->ip6_plen = ntohs(ip6->ip6_plen); 407 break; 408 } 409#endif 410 default: 411 error = EINVAL; 412 INP_RUNLOCK(inp); 413 goto cantsend; 414 } 415 416 /* Send packet to output processing */ 417 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 418 419#ifdef MAC 420 mac_inpcb_create_mbuf(inp, m); 421#endif 422 /* 423 * Get ready to inject the packet into ip_output(). 424 * Just in case socket options were specified on the 425 * divert socket, we duplicate them. This is done 426 * to avoid having to hold the PCB locks over the call 427 * to ip_output(), as doing this results in a number of 428 * lock ordering complexities. 429 * 430 * Note that we set the multicast options argument for 431 * ip_output() to NULL since it should be invariant that 432 * they are not present. 433 */ 434 KASSERT(inp->inp_moptions == NULL, 435 ("multicast options set on a divert socket")); 436 /* 437 * XXXCSJP: It is unclear to me whether or not it makes 438 * sense for divert sockets to have options. However, 439 * for now we will duplicate them with the INP locks 440 * held so we can use them in ip_output() without 441 * requring a reference to the pcb. 442 */ 443 if (inp->inp_options != NULL) { 444 options = m_dup(inp->inp_options, M_NOWAIT); 445 if (options == NULL) { 446 INP_RUNLOCK(inp); 447 error = ENOBUFS; 448 goto cantsend; 449 } 450 } 451 INP_RUNLOCK(inp); 452 453 switch (ip->ip_v) { 454 case IPVERSION: 455 error = ip_output(m, options, NULL, 456 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 457 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 458 break; 459#ifdef INET6 460 case IPV6_VERSION >> 4: 461 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 462 break; 463#endif 464 } 465 if (options != NULL) 466 m_freem(options); 467 } else { 468 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 469 if (m->m_pkthdr.rcvif == NULL) { 470 /* 471 * No luck with the name, check by IP address. 472 * Clear the port and the ifname to make sure 473 * there are no distractions for ifa_ifwithaddr. 474 */ 475 struct ifaddr *ifa; 476 477 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 478 sin->sin_port = 0; 479 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 480 if (ifa == NULL) { 481 error = EADDRNOTAVAIL; 482 goto cantsend; 483 } 484 m->m_pkthdr.rcvif = ifa->ifa_ifp; 485 ifa_free(ifa); 486 } 487#ifdef MAC 488 mac_socket_create_mbuf(so, m); 489#endif 490 /* Send packet to input processing via netisr */ 491 switch (ip->ip_v) { 492 case IPVERSION: 493 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 494 break; 495#ifdef INET6 496 case IPV6_VERSION >> 4: 497 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 498 break; 499#endif 500 default: 501 error = EINVAL; 502 goto cantsend; 503 } 504 } 505 506 return (error); 507 508cantsend: 509 m_freem(m); 510 return (error); 511} 512 513static int 514div_attach(struct socket *so, int proto, struct thread *td) 515{ 516 struct inpcb *inp; 517 int error; 518 519 inp = sotoinpcb(so); 520 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 521 if (td != NULL) { 522 error = priv_check(td, PRIV_NETINET_DIVERT); 523 if (error) 524 return (error); 525 } 526 error = soreserve(so, div_sendspace, div_recvspace); 527 if (error) 528 return error; 529 INP_INFO_WLOCK(&V_divcbinfo); 530 error = in_pcballoc(so, &V_divcbinfo); 531 if (error) { 532 INP_INFO_WUNLOCK(&V_divcbinfo); 533 return error; 534 } 535 inp = (struct inpcb *)so->so_pcb; 536 INP_INFO_WUNLOCK(&V_divcbinfo); 537 inp->inp_ip_p = proto; 538 inp->inp_vflag |= INP_IPV4; 539 inp->inp_flags |= INP_HDRINCL; 540 INP_WUNLOCK(inp); 541 return 0; 542} 543 544static void 545div_detach(struct socket *so) 546{ 547 struct inpcb *inp; 548 549 inp = sotoinpcb(so); 550 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 551 INP_INFO_WLOCK(&V_divcbinfo); 552 INP_WLOCK(inp); 553 in_pcbdetach(inp); 554 in_pcbfree(inp); 555 INP_INFO_WUNLOCK(&V_divcbinfo); 556} 557 558static int 559div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 560{ 561 struct inpcb *inp; 562 int error; 563 564 inp = sotoinpcb(so); 565 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 566 /* in_pcbbind assumes that nam is a sockaddr_in 567 * and in_pcbbind requires a valid address. Since divert 568 * sockets don't we need to make sure the address is 569 * filled in properly. 570 * XXX -- divert should not be abusing in_pcbind 571 * and should probably have its own family. 572 */ 573 if (nam->sa_family != AF_INET) 574 return EAFNOSUPPORT; 575 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 576 INP_INFO_WLOCK(&V_divcbinfo); 577 INP_WLOCK(inp); 578 INP_HASH_WLOCK(&V_divcbinfo); 579 error = in_pcbbind(inp, nam, td->td_ucred); 580 INP_HASH_WUNLOCK(&V_divcbinfo); 581 INP_WUNLOCK(inp); 582 INP_INFO_WUNLOCK(&V_divcbinfo); 583 return error; 584} 585 586static int 587div_shutdown(struct socket *so) 588{ 589 struct inpcb *inp; 590 591 inp = sotoinpcb(so); 592 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 593 INP_WLOCK(inp); 594 socantsendmore(so); 595 INP_WUNLOCK(inp); 596 return 0; 597} 598 599static int 600div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 601 struct mbuf *control, struct thread *td) 602{ 603 604 /* Packet must have a header (but that's about it) */ 605 if (m->m_len < sizeof (struct ip) && 606 (m = m_pullup(m, sizeof (struct ip))) == 0) { 607 KMOD_IPSTAT_INC(ips_toosmall); 608 m_freem(m); 609 return EINVAL; 610 } 611 612 /* Send packet */ 613 return div_output(so, m, (struct sockaddr_in *)nam, control); 614} 615 616static void 617div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 618{ 619 struct in_addr faddr; 620 621 faddr = ((struct sockaddr_in *)sa)->sin_addr; 622 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 623 return; 624 if (PRC_IS_REDIRECT(cmd)) 625 return; 626} 627 628static int 629div_pcblist(SYSCTL_HANDLER_ARGS) 630{ 631 int error, i, n; 632 struct inpcb *inp, **inp_list; 633 inp_gen_t gencnt; 634 struct xinpgen xig; 635 636 /* 637 * The process of preparing the TCB list is too time-consuming and 638 * resource-intensive to repeat twice on every request. 639 */ 640 if (req->oldptr == 0) { 641 n = V_divcbinfo.ipi_count; 642 n += imax(n / 8, 10); 643 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 644 return 0; 645 } 646 647 if (req->newptr != 0) 648 return EPERM; 649 650 /* 651 * OK, now we're committed to doing something. 652 */ 653 INP_INFO_RLOCK(&V_divcbinfo); 654 gencnt = V_divcbinfo.ipi_gencnt; 655 n = V_divcbinfo.ipi_count; 656 INP_INFO_RUNLOCK(&V_divcbinfo); 657 658 error = sysctl_wire_old_buffer(req, 659 2 * sizeof(xig) + n*sizeof(struct xinpcb)); 660 if (error != 0) 661 return (error); 662 663 xig.xig_len = sizeof xig; 664 xig.xig_count = n; 665 xig.xig_gen = gencnt; 666 xig.xig_sogen = so_gencnt; 667 error = SYSCTL_OUT(req, &xig, sizeof xig); 668 if (error) 669 return error; 670 671 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 672 if (inp_list == 0) 673 return ENOMEM; 674 675 INP_INFO_RLOCK(&V_divcbinfo); 676 for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n; 677 inp = LIST_NEXT(inp, inp_list)) { 678 INP_WLOCK(inp); 679 if (inp->inp_gencnt <= gencnt && 680 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 681 in_pcbref(inp); 682 inp_list[i++] = inp; 683 } 684 INP_WUNLOCK(inp); 685 } 686 INP_INFO_RUNLOCK(&V_divcbinfo); 687 n = i; 688 689 error = 0; 690 for (i = 0; i < n; i++) { 691 inp = inp_list[i]; 692 INP_RLOCK(inp); 693 if (inp->inp_gencnt <= gencnt) { 694 struct xinpcb xi; 695 bzero(&xi, sizeof(xi)); 696 xi.xi_len = sizeof xi; 697 /* XXX should avoid extra copy */ 698 bcopy(inp, &xi.xi_inp, sizeof *inp); 699 if (inp->inp_socket) 700 sotoxsocket(inp->inp_socket, &xi.xi_socket); 701 INP_RUNLOCK(inp); 702 error = SYSCTL_OUT(req, &xi, sizeof xi); 703 } else 704 INP_RUNLOCK(inp); 705 } 706 INP_INFO_WLOCK(&V_divcbinfo); 707 for (i = 0; i < n; i++) { 708 inp = inp_list[i]; 709 INP_RLOCK(inp); 710 if (!in_pcbrele_rlocked(inp)) 711 INP_RUNLOCK(inp); 712 } 713 INP_INFO_WUNLOCK(&V_divcbinfo); 714 715 if (!error) { 716 /* 717 * Give the user an updated idea of our state. 718 * If the generation differs from what we told 719 * her before, she knows that something happened 720 * while we were processing this request, and it 721 * might be necessary to retry. 722 */ 723 INP_INFO_RLOCK(&V_divcbinfo); 724 xig.xig_gen = V_divcbinfo.ipi_gencnt; 725 xig.xig_sogen = so_gencnt; 726 xig.xig_count = V_divcbinfo.ipi_count; 727 INP_INFO_RUNLOCK(&V_divcbinfo); 728 error = SYSCTL_OUT(req, &xig, sizeof xig); 729 } 730 free(inp_list, M_TEMP); 731 return error; 732} 733 734#ifdef SYSCTL_NODE 735static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, 736 "IPDIVERT"); 737SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 738 NULL, 0, div_pcblist, "S,xinpcb", "List of active divert sockets"); 739#endif 740 741struct pr_usrreqs div_usrreqs = { 742 .pru_attach = div_attach, 743 .pru_bind = div_bind, 744 .pru_control = in_control, 745 .pru_detach = div_detach, 746 .pru_peeraddr = in_getpeeraddr, 747 .pru_send = div_send, 748 .pru_shutdown = div_shutdown, 749 .pru_sockaddr = in_getsockaddr, 750 .pru_sosetlabel = in_pcbsosetlabel 751}; 752 753struct protosw div_protosw = { 754 .pr_type = SOCK_RAW, 755 .pr_protocol = IPPROTO_DIVERT, 756 .pr_flags = PR_ATOMIC|PR_ADDR, 757 .pr_input = div_input, 758 .pr_ctlinput = div_ctlinput, 759 .pr_ctloutput = ip_ctloutput, 760 .pr_init = div_init, 761#ifdef VIMAGE 762 .pr_destroy = div_destroy, 763#endif 764 .pr_usrreqs = &div_usrreqs 765}; 766 767static int 768div_modevent(module_t mod, int type, void *unused) 769{ 770 int err = 0; 771#ifndef VIMAGE 772 int n; 773#endif 774 775 switch (type) { 776 case MOD_LOAD: 777 /* 778 * Protocol will be initialized by pf_proto_register(). 779 * We don't have to register ip_protox because we are not 780 * a true IP protocol that goes over the wire. 781 */ 782 err = pf_proto_register(PF_INET, &div_protosw); 783 if (err != 0) 784 return (err); 785 ip_divert_ptr = divert_packet; 786 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 787 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 788 break; 789 case MOD_QUIESCE: 790 /* 791 * IPDIVERT may normally not be unloaded because of the 792 * potential race conditions. Tell kldunload we can't be 793 * unloaded unless the unload is forced. 794 */ 795 err = EPERM; 796 break; 797 case MOD_UNLOAD: 798#ifdef VIMAGE 799 err = EPERM; 800 break; 801#else 802 /* 803 * Forced unload. 804 * 805 * Module ipdivert can only be unloaded if no sockets are 806 * connected. Maybe this can be changed later to forcefully 807 * disconnect any open sockets. 808 * 809 * XXXRW: Note that there is a slight race here, as a new 810 * socket open request could be spinning on the lock and then 811 * we destroy the lock. 812 */ 813 INP_INFO_WLOCK(&V_divcbinfo); 814 n = V_divcbinfo.ipi_count; 815 if (n != 0) { 816 err = EBUSY; 817 INP_INFO_WUNLOCK(&V_divcbinfo); 818 break; 819 } 820 ip_divert_ptr = NULL; 821 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 822 INP_INFO_WUNLOCK(&V_divcbinfo); 823 div_destroy(); 824 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 825 break; 826#endif /* !VIMAGE */ 827 default: 828 err = EOPNOTSUPP; 829 break; 830 } 831 return err; 832} 833 834static moduledata_t ipdivertmod = { 835 "ipdivert", 836 div_modevent, 837 NULL 838}; 839 840DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 841MODULE_DEPEND(ipdivert, ipfw, 2, 2, 2); 842MODULE_VERSION(ipdivert, 1); 843