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