ip_divert.c revision 222748
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 222748 2011-06-06 12:55:02Z rwatson $"); 32 33#if !defined(KLD_MODULE) 34#include "opt_inet.h" 35#include "opt_sctp.h" 36#ifndef INET 37#error "IPDIVERT requires INET." 38#endif 39#endif 40 41#include <sys/param.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/netisr.h> 58 59#include <netinet/in.h> 60#include <netinet/in_pcb.h> 61#include <netinet/in_systm.h> 62#include <netinet/in_var.h> 63#include <netinet/ip.h> 64#include <netinet/ip_var.h> 65#ifdef SCTP 66#include <netinet/sctp_crc32.h> 67#endif 68 69#include <security/mac/mac_framework.h> 70 71/* 72 * Divert sockets 73 */ 74 75/* 76 * Allocate enough space to hold a full IP packet 77 */ 78#define DIVSNDQ (65536 + 100) 79#define DIVRCVQ (65536 + 100) 80 81/* 82 * Divert sockets work in conjunction with ipfw or other packet filters, 83 * see the divert(4) manpage for features. 84 * Packets are selected by the packet filter and tagged with an 85 * MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by 86 * the packet filter) and information on the matching filter rule for 87 * subsequent reinjection. The divert_port is used to put the packet 88 * on the corresponding divert socket, while the rule number is passed 89 * up (at least partially) as the sin_port in the struct sockaddr. 90 * 91 * Packets written to the divert socket carry in sin_addr a 92 * destination address, and in sin_port the number of the filter rule 93 * after which to continue processing. 94 * If the destination address is INADDR_ANY, the packet is treated as 95 * as outgoing and sent to ip_output(); otherwise it is treated as 96 * incoming and sent to ip_input(). 97 * Further, sin_zero carries some information on the interface, 98 * which can be used in the reinject -- see comments in the code. 99 * 100 * On reinjection, processing in ip_input() and ip_output() 101 * will be exactly the same as for the original packet, except that 102 * packet filter processing will start at the rule number after the one 103 * written in the sin_port (ipfw does not allow a rule #0, so sin_port=0 104 * will apply the entire ruleset to the packet). 105 */ 106 107/* Internal variables. */ 108static VNET_DEFINE(struct inpcbhead, divcb); 109static VNET_DEFINE(struct inpcbinfo, divcbinfo); 110 111#define V_divcb VNET(divcb) 112#define V_divcbinfo VNET(divcbinfo) 113 114static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 115static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 116 117static eventhandler_tag ip_divert_event_tag; 118 119/* 120 * Initialize divert connection block queue. 121 */ 122static void 123div_zone_change(void *tag) 124{ 125 126 uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets); 127} 128 129static int 130div_inpcb_init(void *mem, int size, int flags) 131{ 132 struct inpcb *inp = mem; 133 134 INP_LOCK_INIT(inp, "inp", "divinp"); 135 return (0); 136} 137 138static void 139div_inpcb_fini(void *mem, int size) 140{ 141 struct inpcb *inp = mem; 142 143 INP_LOCK_DESTROY(inp); 144} 145 146static void 147div_init(void) 148{ 149 150 /* 151 * XXX We don't use the hash list for divert IP, but it's easier to 152 * allocate one-entry hash lists than it is to check all over the 153 * place for hashbase == NULL. 154 */ 155 in_pcbinfo_init(&V_divcbinfo, "div", &V_divcb, 1, 1, "divcb", 156 div_inpcb_init, div_inpcb_fini, UMA_ZONE_NOFREE, 157 IPI_HASHFIELDS_NONE); 158} 159 160static void 161div_destroy(void) 162{ 163 164 in_pcbinfo_destroy(&V_divcbinfo); 165} 166 167/* 168 * IPPROTO_DIVERT is not in the real IP protocol number space; this 169 * function should never be called. Just in case, drop any packets. 170 */ 171static void 172div_input(struct mbuf *m, int off) 173{ 174 175 KMOD_IPSTAT_INC(ips_noproto); 176 m_freem(m); 177} 178 179/* 180 * Divert a packet by passing it up to the divert socket at port 'port'. 181 * 182 * Setup generic address and protocol structures for div_input routine, 183 * then pass them along with mbuf chain. 184 */ 185static void 186divert_packet(struct mbuf *m, int incoming) 187{ 188 struct ip *ip; 189 struct inpcb *inp; 190 struct socket *sa; 191 u_int16_t nport; 192 struct sockaddr_in divsrc; 193 struct m_tag *mtag; 194 195 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 196 if (mtag == NULL) { 197 m_freem(m); 198 return; 199 } 200 /* Assure header */ 201 if (m->m_len < sizeof(struct ip) && 202 (m = m_pullup(m, sizeof(struct ip))) == 0) 203 return; 204 ip = mtod(m, struct ip *); 205 206 /* Delayed checksums are currently not compatible with divert. */ 207 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 208 ip->ip_len = ntohs(ip->ip_len); 209 in_delayed_cksum(m); 210 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 211 ip->ip_len = htons(ip->ip_len); 212 } 213#ifdef SCTP 214 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 215 ip->ip_len = ntohs(ip->ip_len); 216 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 217 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 218 ip->ip_len = htons(ip->ip_len); 219 } 220#endif 221 bzero(&divsrc, sizeof(divsrc)); 222 divsrc.sin_len = sizeof(divsrc); 223 divsrc.sin_family = AF_INET; 224 /* record matching rule, in host format */ 225 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 226 /* 227 * Record receive interface address, if any. 228 * But only for incoming packets. 229 */ 230 if (incoming) { 231 struct ifaddr *ifa; 232 struct ifnet *ifp; 233 234 /* Sanity check */ 235 M_ASSERTPKTHDR(m); 236 237 /* Find IP address for receive interface */ 238 ifp = m->m_pkthdr.rcvif; 239 if_addr_rlock(ifp); 240 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 241 if (ifa->ifa_addr->sa_family != AF_INET) 242 continue; 243 divsrc.sin_addr = 244 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 245 break; 246 } 247 if_addr_runlock(ifp); 248 } 249 /* 250 * Record the incoming interface name whenever we have one. 251 */ 252 if (m->m_pkthdr.rcvif) { 253 /* 254 * Hide the actual interface name in there in the 255 * sin_zero array. XXX This needs to be moved to a 256 * different sockaddr type for divert, e.g. 257 * sockaddr_div with multiple fields like 258 * sockaddr_dl. Presently we have only 7 bytes 259 * but that will do for now as most interfaces 260 * are 4 or less + 2 or less bytes for unit. 261 * There is probably a faster way of doing this, 262 * possibly taking it from the sockaddr_dl on the iface. 263 * This solves the problem of a P2P link and a LAN interface 264 * having the same address, which can result in the wrong 265 * interface being assigned to the packet when fed back 266 * into the divert socket. Theoretically if the daemon saves 267 * and re-uses the sockaddr_in as suggested in the man pages, 268 * this iface name will come along for the ride. 269 * (see div_output for the other half of this.) 270 */ 271 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 272 sizeof(divsrc.sin_zero)); 273 } 274 275 /* Put packet on socket queue, if any */ 276 sa = NULL; 277 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 278 INP_INFO_RLOCK(&V_divcbinfo); 279 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 INP_INFO_RUNLOCK(&V_divcbinfo); 297 if (sa == NULL) { 298 m_freem(m); 299 KMOD_IPSTAT_INC(ips_noproto); 300 KMOD_IPSTAT_DEC(ips_delivered); 301 } 302} 303 304/* 305 * Deliver packet back into the IP processing machinery. 306 * 307 * If no address specified, or address is 0.0.0.0, send to ip_output(); 308 * otherwise, send to ip_input() and mark as having been received on 309 * the interface with that address. 310 */ 311static int 312div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 313 struct mbuf *control) 314{ 315 struct m_tag *mtag; 316 struct ipfw_rule_ref *dt; 317 int error = 0; 318 struct mbuf *options; 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 error = ENOBUFS; 338 goto cantsend; 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 /* 357 * Find receive interface with the given name, stuffed 358 * (if it exists) in the sin_zero[] field. 359 * The name is user supplied data so don't trust its size 360 * or that it is zero terminated. 361 */ 362 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 363 ; 364 if ( i > 0 && i < sizeof(sin->sin_zero)) 365 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 366 } 367 368 /* Reinject packet into the system as incoming or outgoing */ 369 if (!sin || sin->sin_addr.s_addr == 0) { 370 struct ip *const ip = mtod(m, struct ip *); 371 struct inpcb *inp; 372 373 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 374 inp = sotoinpcb(so); 375 INP_RLOCK(inp); 376 /* 377 * Don't allow both user specified and setsockopt options, 378 * and don't allow packet length sizes that will crash 379 */ 380 if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) || 381 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 382 error = EINVAL; 383 INP_RUNLOCK(inp); 384 m_freem(m); 385 } else { 386 /* Convert fields to host order for ip_output() */ 387 ip->ip_len = ntohs(ip->ip_len); 388 ip->ip_off = ntohs(ip->ip_off); 389 390 /* Send packet to output processing */ 391 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 392 393#ifdef MAC 394 mac_inpcb_create_mbuf(inp, m); 395#endif 396 /* 397 * Get ready to inject the packet into ip_output(). 398 * Just in case socket options were specified on the 399 * divert socket, we duplicate them. This is done 400 * to avoid having to hold the PCB locks over the call 401 * to ip_output(), as doing this results in a number of 402 * lock ordering complexities. 403 * 404 * Note that we set the multicast options argument for 405 * ip_output() to NULL since it should be invariant that 406 * they are not present. 407 */ 408 KASSERT(inp->inp_moptions == NULL, 409 ("multicast options set on a divert socket")); 410 options = NULL; 411 /* 412 * XXXCSJP: It is unclear to me whether or not it makes 413 * sense for divert sockets to have options. However, 414 * for now we will duplicate them with the INP locks 415 * held so we can use them in ip_output() without 416 * requring a reference to the pcb. 417 */ 418 if (inp->inp_options != NULL) { 419 options = m_dup(inp->inp_options, M_DONTWAIT); 420 if (options == NULL) 421 error = ENOBUFS; 422 } 423 INP_RUNLOCK(inp); 424 if (error == ENOBUFS) { 425 m_freem(m); 426 return (error); 427 } 428 error = ip_output(m, options, NULL, 429 ((so->so_options & SO_DONTROUTE) ? 430 IP_ROUTETOIF : 0) | IP_ALLOWBROADCAST | 431 IP_RAWOUTPUT, NULL, NULL); 432 if (options != NULL) 433 m_freem(options); 434 } 435 } else { 436 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 437 if (m->m_pkthdr.rcvif == NULL) { 438 /* 439 * No luck with the name, check by IP address. 440 * Clear the port and the ifname to make sure 441 * there are no distractions for ifa_ifwithaddr. 442 */ 443 struct ifaddr *ifa; 444 445 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 446 sin->sin_port = 0; 447 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 448 if (ifa == NULL) { 449 error = EADDRNOTAVAIL; 450 goto cantsend; 451 } 452 m->m_pkthdr.rcvif = ifa->ifa_ifp; 453 ifa_free(ifa); 454 } 455#ifdef MAC 456 mac_socket_create_mbuf(so, m); 457#endif 458 /* Send packet to input processing via netisr */ 459 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 460 } 461 462 return error; 463 464cantsend: 465 m_freem(m); 466 return error; 467} 468 469static int 470div_attach(struct socket *so, int proto, struct thread *td) 471{ 472 struct inpcb *inp; 473 int error; 474 475 inp = sotoinpcb(so); 476 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 477 if (td != NULL) { 478 error = priv_check(td, PRIV_NETINET_DIVERT); 479 if (error) 480 return (error); 481 } 482 error = soreserve(so, div_sendspace, div_recvspace); 483 if (error) 484 return error; 485 INP_INFO_WLOCK(&V_divcbinfo); 486 error = in_pcballoc(so, &V_divcbinfo); 487 if (error) { 488 INP_INFO_WUNLOCK(&V_divcbinfo); 489 return error; 490 } 491 inp = (struct inpcb *)so->so_pcb; 492 INP_INFO_WUNLOCK(&V_divcbinfo); 493 inp->inp_ip_p = proto; 494 inp->inp_vflag |= INP_IPV4; 495 inp->inp_flags |= INP_HDRINCL; 496 INP_WUNLOCK(inp); 497 return 0; 498} 499 500static void 501div_detach(struct socket *so) 502{ 503 struct inpcb *inp; 504 505 inp = sotoinpcb(so); 506 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 507 INP_INFO_WLOCK(&V_divcbinfo); 508 INP_WLOCK(inp); 509 in_pcbdetach(inp); 510 in_pcbfree(inp); 511 INP_INFO_WUNLOCK(&V_divcbinfo); 512} 513 514static int 515div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 516{ 517 struct inpcb *inp; 518 int error; 519 520 inp = sotoinpcb(so); 521 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 522 /* in_pcbbind assumes that nam is a sockaddr_in 523 * and in_pcbbind requires a valid address. Since divert 524 * sockets don't we need to make sure the address is 525 * filled in properly. 526 * XXX -- divert should not be abusing in_pcbind 527 * and should probably have its own family. 528 */ 529 if (nam->sa_family != AF_INET) 530 return EAFNOSUPPORT; 531 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 532 INP_INFO_WLOCK(&V_divcbinfo); 533 INP_WLOCK(inp); 534 INP_HASH_WLOCK(&V_divcbinfo); 535 error = in_pcbbind(inp, nam, td->td_ucred); 536 INP_HASH_WUNLOCK(&V_divcbinfo); 537 INP_WUNLOCK(inp); 538 INP_INFO_WUNLOCK(&V_divcbinfo); 539 return error; 540} 541 542static int 543div_shutdown(struct socket *so) 544{ 545 struct inpcb *inp; 546 547 inp = sotoinpcb(so); 548 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 549 INP_WLOCK(inp); 550 socantsendmore(so); 551 INP_WUNLOCK(inp); 552 return 0; 553} 554 555static int 556div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 557 struct mbuf *control, struct thread *td) 558{ 559 560 /* Packet must have a header (but that's about it) */ 561 if (m->m_len < sizeof (struct ip) && 562 (m = m_pullup(m, sizeof (struct ip))) == 0) { 563 KMOD_IPSTAT_INC(ips_toosmall); 564 m_freem(m); 565 return EINVAL; 566 } 567 568 /* Send packet */ 569 return div_output(so, m, (struct sockaddr_in *)nam, control); 570} 571 572static void 573div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 574{ 575 struct in_addr faddr; 576 577 faddr = ((struct sockaddr_in *)sa)->sin_addr; 578 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 579 return; 580 if (PRC_IS_REDIRECT(cmd)) 581 return; 582} 583 584static int 585div_pcblist(SYSCTL_HANDLER_ARGS) 586{ 587 int error, i, n; 588 struct inpcb *inp, **inp_list; 589 inp_gen_t gencnt; 590 struct xinpgen xig; 591 592 /* 593 * The process of preparing the TCB list is too time-consuming and 594 * resource-intensive to repeat twice on every request. 595 */ 596 if (req->oldptr == 0) { 597 n = V_divcbinfo.ipi_count; 598 n += imax(n / 8, 10); 599 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 600 return 0; 601 } 602 603 if (req->newptr != 0) 604 return EPERM; 605 606 /* 607 * OK, now we're committed to doing something. 608 */ 609 INP_INFO_RLOCK(&V_divcbinfo); 610 gencnt = V_divcbinfo.ipi_gencnt; 611 n = V_divcbinfo.ipi_count; 612 INP_INFO_RUNLOCK(&V_divcbinfo); 613 614 error = sysctl_wire_old_buffer(req, 615 2 * sizeof(xig) + n*sizeof(struct xinpcb)); 616 if (error != 0) 617 return (error); 618 619 xig.xig_len = sizeof xig; 620 xig.xig_count = n; 621 xig.xig_gen = gencnt; 622 xig.xig_sogen = so_gencnt; 623 error = SYSCTL_OUT(req, &xig, sizeof xig); 624 if (error) 625 return error; 626 627 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 628 if (inp_list == 0) 629 return ENOMEM; 630 631 INP_INFO_RLOCK(&V_divcbinfo); 632 for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n; 633 inp = LIST_NEXT(inp, inp_list)) { 634 INP_WLOCK(inp); 635 if (inp->inp_gencnt <= gencnt && 636 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 637 in_pcbref(inp); 638 inp_list[i++] = inp; 639 } 640 INP_WUNLOCK(inp); 641 } 642 INP_INFO_RUNLOCK(&V_divcbinfo); 643 n = i; 644 645 error = 0; 646 for (i = 0; i < n; i++) { 647 inp = inp_list[i]; 648 INP_RLOCK(inp); 649 if (inp->inp_gencnt <= gencnt) { 650 struct xinpcb xi; 651 bzero(&xi, sizeof(xi)); 652 xi.xi_len = sizeof xi; 653 /* XXX should avoid extra copy */ 654 bcopy(inp, &xi.xi_inp, sizeof *inp); 655 if (inp->inp_socket) 656 sotoxsocket(inp->inp_socket, &xi.xi_socket); 657 INP_RUNLOCK(inp); 658 error = SYSCTL_OUT(req, &xi, sizeof xi); 659 } else 660 INP_RUNLOCK(inp); 661 } 662 INP_INFO_WLOCK(&V_divcbinfo); 663 for (i = 0; i < n; i++) { 664 inp = inp_list[i]; 665 INP_RLOCK(inp); 666 if (!in_pcbrele_rlocked(inp)) 667 INP_RUNLOCK(inp); 668 } 669 INP_INFO_WUNLOCK(&V_divcbinfo); 670 671 if (!error) { 672 /* 673 * Give the user an updated idea of our state. 674 * If the generation differs from what we told 675 * her before, she knows that something happened 676 * while we were processing this request, and it 677 * might be necessary to retry. 678 */ 679 INP_INFO_RLOCK(&V_divcbinfo); 680 xig.xig_gen = V_divcbinfo.ipi_gencnt; 681 xig.xig_sogen = so_gencnt; 682 xig.xig_count = V_divcbinfo.ipi_count; 683 INP_INFO_RUNLOCK(&V_divcbinfo); 684 error = SYSCTL_OUT(req, &xig, sizeof xig); 685 } 686 free(inp_list, M_TEMP); 687 return error; 688} 689 690#ifdef SYSCTL_NODE 691SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, "IPDIVERT"); 692SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 693 NULL, 0, div_pcblist, "S,xinpcb", "List of active divert sockets"); 694#endif 695 696struct pr_usrreqs div_usrreqs = { 697 .pru_attach = div_attach, 698 .pru_bind = div_bind, 699 .pru_control = in_control, 700 .pru_detach = div_detach, 701 .pru_peeraddr = in_getpeeraddr, 702 .pru_send = div_send, 703 .pru_shutdown = div_shutdown, 704 .pru_sockaddr = in_getsockaddr, 705 .pru_sosetlabel = in_pcbsosetlabel 706}; 707 708struct protosw div_protosw = { 709 .pr_type = SOCK_RAW, 710 .pr_protocol = IPPROTO_DIVERT, 711 .pr_flags = PR_ATOMIC|PR_ADDR, 712 .pr_input = div_input, 713 .pr_ctlinput = div_ctlinput, 714 .pr_ctloutput = ip_ctloutput, 715 .pr_init = div_init, 716#ifdef VIMAGE 717 .pr_destroy = div_destroy, 718#endif 719 .pr_usrreqs = &div_usrreqs 720}; 721 722static int 723div_modevent(module_t mod, int type, void *unused) 724{ 725 int err = 0; 726#ifndef VIMAGE 727 int n; 728#endif 729 730 switch (type) { 731 case MOD_LOAD: 732 /* 733 * Protocol will be initialized by pf_proto_register(). 734 * We don't have to register ip_protox because we are not 735 * a true IP protocol that goes over the wire. 736 */ 737 err = pf_proto_register(PF_INET, &div_protosw); 738 if (err != 0) 739 return (err); 740 ip_divert_ptr = divert_packet; 741 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 742 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 743 break; 744 case MOD_QUIESCE: 745 /* 746 * IPDIVERT may normally not be unloaded because of the 747 * potential race conditions. Tell kldunload we can't be 748 * unloaded unless the unload is forced. 749 */ 750 err = EPERM; 751 break; 752 case MOD_UNLOAD: 753#ifdef VIMAGE 754 err = EPERM; 755 break; 756#else 757 /* 758 * Forced unload. 759 * 760 * Module ipdivert can only be unloaded if no sockets are 761 * connected. Maybe this can be changed later to forcefully 762 * disconnect any open sockets. 763 * 764 * XXXRW: Note that there is a slight race here, as a new 765 * socket open request could be spinning on the lock and then 766 * we destroy the lock. 767 */ 768 INP_INFO_WLOCK(&V_divcbinfo); 769 n = V_divcbinfo.ipi_count; 770 if (n != 0) { 771 err = EBUSY; 772 INP_INFO_WUNLOCK(&V_divcbinfo); 773 break; 774 } 775 ip_divert_ptr = NULL; 776 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 777 INP_INFO_WUNLOCK(&V_divcbinfo); 778 div_destroy(); 779 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 780 break; 781#endif /* !VIMAGE */ 782 default: 783 err = EOPNOTSUPP; 784 break; 785 } 786 return err; 787} 788 789static moduledata_t ipdivertmod = { 790 "ipdivert", 791 div_modevent, 792 0 793}; 794 795DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 796MODULE_DEPEND(ipdivert, ipfw, 2, 2, 2); 797MODULE_VERSION(ipdivert, 1); 798