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, UMA_ZONE_NOFREE, 162 IPI_HASHFIELDS_NONE); 163 } 164 165 static void 166 div_destroy(void) 167 { 168 169 in_pcbinfo_destroy(&V_divcbinfo); 170 } 171 172 /* 173 * IPPROTO_DIVERT is not in the real IP protocol number space; this 174 * function should never be called. Just in case, drop any packets. 175 */ 176 static void 177 div_input(struct mbuf *m, int off) 178 { 179 180 KMOD_IPSTAT_INC(ips_noproto); 181 m_freem(m); 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, int 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 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 201 if (mtag == NULL) { 202 m_freem(m); 203 return; 204 } 205 /* Assure header */ 206 if (m->m_len < sizeof(struct ip) && 207 (m = m_pullup(m, sizeof(struct ip))) == 0) 208 return; 209 ip = mtod(m, struct ip *); 210 211 /* Delayed checksums are currently not compatible with divert. */ 212 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 213 in_delayed_cksum(m); 214 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 215 } 216 #ifdef SCTP 217 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 218 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 219 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 220 } 221 #endif 222 bzero(&divsrc, sizeof(divsrc)); 223 divsrc.sin_len = sizeof(divsrc); 224 divsrc.sin_family = AF_INET; 225 /* record matching rule, in host format */ 226 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 227 /* 228 * Record receive interface address, if any. 229 * But only for incoming packets. 230 */ 231 if (incoming) { 232 struct ifaddr *ifa; 233 struct ifnet *ifp; 234 235 /* Sanity check */ 236 M_ASSERTPKTHDR(m); 237 238 /* Find IP address for receive interface */ 239 ifp = m->m_pkthdr.rcvif; 240 if_addr_rlock(ifp); 241 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 242 if (ifa->ifa_addr->sa_family != AF_INET) 243 continue; 244 divsrc.sin_addr = 245 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 246 break; 247 } 248 if_addr_runlock(ifp); 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 INP_INFO_RLOCK(&V_divcbinfo); 280 LIST_FOREACH(inp, &V_divcb, inp_list) { 281 /* XXX why does only one socket match? */ 282 if (inp->inp_lport == nport) { 283 INP_RLOCK(inp); 284 sa = inp->inp_socket; 285 SOCKBUF_LOCK(&sa->so_rcv); 286 if (sbappendaddr_locked(&sa->so_rcv, 287 (struct sockaddr *)&divsrc, m, 288 (struct mbuf *)0) == 0) { 289 SOCKBUF_UNLOCK(&sa->so_rcv); 290 sa = NULL; /* force mbuf reclaim below */ 291 } else 292 sorwakeup_locked(sa); 293 INP_RUNLOCK(inp); 294 break; 295 } 296 } 297 INP_INFO_RUNLOCK(&V_divcbinfo); 298 if (sa == NULL) { 299 m_freem(m); 300 KMOD_IPSTAT_INC(ips_noproto); 301 KMOD_IPSTAT_DEC(ips_delivered); 302 } 303 } 304 305 /* 306 * Deliver packet back into the IP processing machinery. 307 * 308 * If no address specified, or address is 0.0.0.0, send to ip_output(); 309 * otherwise, send to ip_input() and mark as having been received on 310 * the interface with that address. 311 */ 312 static int 313 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 314 struct mbuf *control) 315 { 316 struct ip *const ip = mtod(m, struct ip *); 317 struct m_tag *mtag; 318 struct ipfw_rule_ref *dt; 319 int error = 0; 320 321 /* 322 * An mbuf may hasn't come from userland, but we pretend 323 * that it has. 324 */ 325 m->m_pkthdr.rcvif = NULL; 326 m->m_nextpkt = NULL; 327 M_SETFIB(m, so->so_fibnum); 328 329 if (control) 330 m_freem(control); /* XXX */ 331 332 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 333 if (mtag == NULL) { 334 /* this should be normal */ 335 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 336 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 337 if (mtag == NULL) { 338 error = ENOBUFS; 339 goto cantsend; 340 } 341 m_tag_prepend(m, mtag); 342 } 343 dt = (struct ipfw_rule_ref *)(mtag+1); 344 345 /* Loopback avoidance and state recovery */ 346 if (sin) { 347 int i; 348 349 /* set the starting point. We provide a non-zero slot, 350 * but a non_matching chain_id to skip that info and use 351 * the rulenum/rule_id. 352 */ 353 dt->slot = 1; /* dummy, chain_id is invalid */ 354 dt->chain_id = 0; 355 dt->rulenum = sin->sin_port+1; /* host format ? */ 356 dt->rule_id = 0; 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 /* Reinject packet into the system as incoming or outgoing */ 370 if (!sin || sin->sin_addr.s_addr == 0) { 371 struct mbuf *options = NULL; 372 struct inpcb *inp; 373 374 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 375 inp = sotoinpcb(so); 376 INP_RLOCK(inp); 377 switch (ip->ip_v) { 378 case IPVERSION: 379 /* 380 * Don't allow both user specified and setsockopt 381 * options, and don't allow packet length sizes that 382 * will crash. 383 */ 384 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 385 inp->inp_options != NULL) || 386 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 387 error = EINVAL; 388 INP_RUNLOCK(inp); 389 goto cantsend; 390 } 391 break; 392 #ifdef INET6 393 case IPV6_VERSION >> 4: 394 { 395 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 396 397 /* Don't allow packet length sizes that will crash */ 398 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 399 error = EINVAL; 400 INP_RUNLOCK(inp); 401 goto cantsend; 402 } 403 break; 404 } 405 #endif 406 default: 407 error = EINVAL; 408 INP_RUNLOCK(inp); 409 goto cantsend; 410 } 411 412 /* Send packet to output processing */ 413 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 414 415 #ifdef MAC 416 mac_inpcb_create_mbuf(inp, m); 417 #endif 418 /* 419 * Get ready to inject the packet into ip_output(). 420 * Just in case socket options were specified on the 421 * divert socket, we duplicate them. This is done 422 * to avoid having to hold the PCB locks over the call 423 * to ip_output(), as doing this results in a number of 424 * lock ordering complexities. 425 * 426 * Note that we set the multicast options argument for 427 * ip_output() to NULL since it should be invariant that 428 * they are not present. 429 */ 430 KASSERT(inp->inp_moptions == NULL, 431 ("multicast options set on a divert socket")); 432 /* 433 * XXXCSJP: It is unclear to me whether or not it makes 434 * sense for divert sockets to have options. However, 435 * for now we will duplicate them with the INP locks 436 * held so we can use them in ip_output() without 437 * requring a reference to the pcb. 438 */ 439 if (inp->inp_options != NULL) { 440 options = m_dup(inp->inp_options, M_NOWAIT); 441 if (options == NULL) { 442 INP_RUNLOCK(inp); 443 error = ENOBUFS; 444 goto cantsend; 445 } 446 } 447 INP_RUNLOCK(inp); 448 449 switch (ip->ip_v) { 450 case IPVERSION: 451 error = ip_output(m, options, NULL, 452 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 453 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 454 break; 455 #ifdef INET6 456 case IPV6_VERSION >> 4: 457 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 458 break; 459 #endif 460 } 461 if (options != NULL) 462 m_freem(options); 463 } else { 464 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 465 if (m->m_pkthdr.rcvif == NULL) { 466 /* 467 * No luck with the name, check by IP address. 468 * Clear the port and the ifname to make sure 469 * there are no distractions for ifa_ifwithaddr. 470 */ 471 struct ifaddr *ifa; 472 473 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 474 sin->sin_port = 0; 475 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 476 if (ifa == NULL) { 477 error = EADDRNOTAVAIL; 478 goto cantsend; 479 } 480 m->m_pkthdr.rcvif = ifa->ifa_ifp; 481 ifa_free(ifa); 482 } 483 #ifdef MAC 484 mac_socket_create_mbuf(so, m); 485 #endif 486 /* Send packet to input processing via netisr */ 487 switch (ip->ip_v) { 488 case IPVERSION: 489 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 490 break; 491 #ifdef INET6 492 case IPV6_VERSION >> 4: 493 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 494 break; 495 #endif 496 default: 497 error = EINVAL; 498 goto cantsend; 499 } 500 } 501 502 return (error); 503 504 cantsend: 505 m_freem(m); 506 return (error); 507 } 508 509 static int 510 div_attach(struct socket *so, int proto, struct thread *td) 511 { 512 struct inpcb *inp; 513 int error; 514 515 inp = sotoinpcb(so); 516 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 517 if (td != NULL) { 518 error = priv_check(td, PRIV_NETINET_DIVERT); 519 if (error) 520 return (error); 521 } 522 error = soreserve(so, div_sendspace, div_recvspace); 523 if (error) 524 return error; 525 INP_INFO_WLOCK(&V_divcbinfo); 526 error = in_pcballoc(so, &V_divcbinfo); 527 if (error) { 528 INP_INFO_WUNLOCK(&V_divcbinfo); 529 return error; 530 } 531 inp = (struct inpcb *)so->so_pcb; 532 INP_INFO_WUNLOCK(&V_divcbinfo); 533 inp->inp_ip_p = proto; 534 inp->inp_vflag |= INP_IPV4; 535 inp->inp_flags |= INP_HDRINCL; 536 INP_WUNLOCK(inp); 537 return 0; 538 } 539 540 static void 541 div_detach(struct socket *so) 542 { 543 struct inpcb *inp; 544 545 inp = sotoinpcb(so); 546 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 547 INP_INFO_WLOCK(&V_divcbinfo); 548 INP_WLOCK(inp); 549 in_pcbdetach(inp); 550 in_pcbfree(inp); 551 INP_INFO_WUNLOCK(&V_divcbinfo); 552 } 553 554 static int 555 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 556 { 557 struct inpcb *inp; 558 int error; 559 560 inp = sotoinpcb(so); 561 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 562 /* in_pcbbind assumes that nam is a sockaddr_in 563 * and in_pcbbind requires a valid address. Since divert 564 * sockets don't we need to make sure the address is 565 * filled in properly. 566 * XXX -- divert should not be abusing in_pcbind 567 * and should probably have its own family. 568 */ 569 if (nam->sa_family != AF_INET) 570 return EAFNOSUPPORT; 571 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 572 INP_INFO_WLOCK(&V_divcbinfo); 573 INP_WLOCK(inp); 574 INP_HASH_WLOCK(&V_divcbinfo); 575 error = in_pcbbind(inp, nam, td->td_ucred); 576 INP_HASH_WUNLOCK(&V_divcbinfo); 577 INP_WUNLOCK(inp); 578 INP_INFO_WUNLOCK(&V_divcbinfo); 579 return error; 580 } 581 582 static int 583 div_shutdown(struct socket *so) 584 { 585 struct inpcb *inp; 586 587 inp = sotoinpcb(so); 588 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 589 INP_WLOCK(inp); 590 socantsendmore(so); 591 INP_WUNLOCK(inp); 592 return 0; 593 } 594 595 static int 596 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 597 struct mbuf *control, struct thread *td) 598 { 599 600 /* Packet must have a header (but that's about it) */ 601 if (m->m_len < sizeof (struct ip) && 602 (m = m_pullup(m, sizeof (struct ip))) == 0) { 603 KMOD_IPSTAT_INC(ips_toosmall); 604 m_freem(m); 605 return EINVAL; 606 } 607 608 /* Send packet */ 609 return div_output(so, m, (struct sockaddr_in *)nam, control); 610 } 611 612 static void 613 div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 614 { 615 struct in_addr faddr; 616 617 faddr = ((struct sockaddr_in *)sa)->sin_addr; 618 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 619 return; 620 if (PRC_IS_REDIRECT(cmd)) 621 return; 622 } 623 624 static int 625 div_pcblist(SYSCTL_HANDLER_ARGS) 626 { 627 int error, i, n; 628 struct inpcb *inp, **inp_list; 629 inp_gen_t gencnt; 630 struct xinpgen xig; 631 632 /* 633 * The process of preparing the TCB list is too time-consuming and 634 * resource-intensive to repeat twice on every request. 635 */ 636 if (req->oldptr == 0) { 637 n = V_divcbinfo.ipi_count; 638 n += imax(n / 8, 10); 639 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 640 return 0; 641 } 642 643 if (req->newptr != 0) 644 return EPERM; 645 646 /* 647 * OK, now we're committed to doing something. 648 */ 649 INP_INFO_RLOCK(&V_divcbinfo); 650 gencnt = V_divcbinfo.ipi_gencnt; 651 n = V_divcbinfo.ipi_count; 652 INP_INFO_RUNLOCK(&V_divcbinfo); 653 654 error = sysctl_wire_old_buffer(req, 655 2 * sizeof(xig) + n*sizeof(struct xinpcb)); 656 if (error != 0) 657 return (error); 658 659 xig.xig_len = sizeof xig; 660 xig.xig_count = n; 661 xig.xig_gen = gencnt; 662 xig.xig_sogen = so_gencnt; 663 error = SYSCTL_OUT(req, &xig, sizeof xig); 664 if (error) 665 return error; 666 667 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 668 if (inp_list == 0) 669 return ENOMEM; 670 671 INP_INFO_RLOCK(&V_divcbinfo); 672 for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n; 673 inp = LIST_NEXT(inp, inp_list)) { 674 INP_WLOCK(inp); 675 if (inp->inp_gencnt <= gencnt && 676 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 677 in_pcbref(inp); 678 inp_list[i++] = inp; 679 } 680 INP_WUNLOCK(inp); 681 } 682 INP_INFO_RUNLOCK(&V_divcbinfo); 683 n = i; 684 685 error = 0; 686 for (i = 0; i < n; i++) { 687 inp = inp_list[i]; 688 INP_RLOCK(inp); 689 if (inp->inp_gencnt <= gencnt) { 690 struct xinpcb xi; 691 bzero(&xi, sizeof(xi)); 692 xi.xi_len = sizeof xi; 693 /* XXX should avoid extra copy */ 694 bcopy(inp, &xi.xi_inp, sizeof *inp); 695 if (inp->inp_socket) 696 sotoxsocket(inp->inp_socket, &xi.xi_socket); 697 INP_RUNLOCK(inp); 698 error = SYSCTL_OUT(req, &xi, sizeof xi); 699 } else 700 INP_RUNLOCK(inp); 701 } 702 INP_INFO_WLOCK(&V_divcbinfo); 703 for (i = 0; i < n; i++) { 704 inp = inp_list[i]; 705 INP_RLOCK(inp); 706 if (!in_pcbrele_rlocked(inp)) 707 INP_RUNLOCK(inp); 708 } 709 INP_INFO_WUNLOCK(&V_divcbinfo); 710 711 if (!error) { 712 /* 713 * Give the user an updated idea of our state. 714 * If the generation differs from what we told 715 * her before, she knows that something happened 716 * while we were processing this request, and it 717 * might be necessary to retry. 718 */ 719 INP_INFO_RLOCK(&V_divcbinfo); 720 xig.xig_gen = V_divcbinfo.ipi_gencnt; 721 xig.xig_sogen = so_gencnt; 722 xig.xig_count = V_divcbinfo.ipi_count; 723 INP_INFO_RUNLOCK(&V_divcbinfo); 724 error = SYSCTL_OUT(req, &xig, sizeof xig); 725 } 726 free(inp_list, M_TEMP); 727 return error; 728 } 729 730 #ifdef SYSCTL_NODE 731 static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, 732 "IPDIVERT"); 733 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 734 NULL, 0, div_pcblist, "S,xinpcb", "List of active divert sockets"); 735 #endif 736 737 struct pr_usrreqs div_usrreqs = { 738 .pru_attach = div_attach, 739 .pru_bind = div_bind, 740 .pru_control = in_control, 741 .pru_detach = div_detach, 742 .pru_peeraddr = in_getpeeraddr, 743 .pru_send = div_send, 744 .pru_shutdown = div_shutdown, 745 .pru_sockaddr = in_getsockaddr, 746 .pru_sosetlabel = in_pcbsosetlabel 747 }; 748 749 struct protosw div_protosw = { 750 .pr_type = SOCK_RAW, 751 .pr_protocol = IPPROTO_DIVERT, 752 .pr_flags = PR_ATOMIC|PR_ADDR, 753 .pr_input = div_input, 754 .pr_ctlinput = div_ctlinput, 755 .pr_ctloutput = ip_ctloutput, 756 .pr_init = div_init, 757 #ifdef VIMAGE 758 .pr_destroy = div_destroy, 759 #endif 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 #ifndef VIMAGE 768 int n; 769 #endif 770 771 switch (type) { 772 case MOD_LOAD: 773 /* 774 * Protocol will be initialized by pf_proto_register(). 775 * We don't have to register ip_protox because we are not 776 * a true IP protocol that goes over the wire. 777 */ 778 err = pf_proto_register(PF_INET, &div_protosw); 779 if (err != 0) 780 return (err); 781 ip_divert_ptr = divert_packet; 782 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 783 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 784 break; 785 case MOD_QUIESCE: 786 /* 787 * IPDIVERT may normally not be unloaded because of the 788 * potential race conditions. Tell kldunload we can't be 789 * unloaded unless the unload is forced. 790 */ 791 err = EPERM; 792 break; 793 case MOD_UNLOAD: 794 #ifdef VIMAGE 795 err = EPERM; 796 break; 797 #else 798 /* 799 * Forced unload. 800 * 801 * Module ipdivert can only be unloaded if no sockets are 802 * connected. Maybe this can be changed later to forcefully 803 * disconnect any open sockets. 804 * 805 * XXXRW: Note that there is a slight race here, as a new 806 * socket open request could be spinning on the lock and then 807 * we destroy the lock. 808 */ 809 INP_INFO_WLOCK(&V_divcbinfo); 810 n = V_divcbinfo.ipi_count; 811 if (n != 0) { 812 err = EBUSY; 813 INP_INFO_WUNLOCK(&V_divcbinfo); 814 break; 815 } 816 ip_divert_ptr = NULL; 817 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 818 INP_INFO_WUNLOCK(&V_divcbinfo); 819 div_destroy(); 820 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 821 break; 822 #endif /* !VIMAGE */ 823 default: 824 err = EOPNOTSUPP; 825 break; 826 } 827 return err; 828 } 829 830 static moduledata_t ipdivertmod = { 831 "ipdivert", 832 div_modevent, 833 0 834 }; 835 836 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 837 MODULE_DEPEND(ipdivert, ipfw, 2, 2, 2); 838 MODULE_VERSION(ipdivert, 1); 839