1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_inet.h" 34 #include "opt_inet6.h" 35 #include "opt_sctp.h" 36 #ifndef INET 37 #error "IPDIVERT requires INET" 38 #endif 39 40 #include <sys/param.h> 41 #include <sys/eventhandler.h> 42 #include <sys/kernel.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/mbuf.h> 46 #include <sys/module.h> 47 #include <sys/kernel.h> 48 #include <sys/priv.h> 49 #include <sys/proc.h> 50 #include <sys/protosw.h> 51 #include <sys/socket.h> 52 #include <sys/socketvar.h> 53 #include <sys/sysctl.h> 54 #include <net/vnet.h> 55 56 #include <net/if.h> 57 #include <net/if_var.h> 58 #include <net/netisr.h> 59 60 #include <netinet/in.h> 61 #include <netinet/in_pcb.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/in_var.h> 64 #include <netinet/ip.h> 65 #include <netinet/ip_var.h> 66 #ifdef INET6 67 #include <netinet/ip6.h> 68 #include <netinet6/ip6_var.h> 69 #endif 70 #ifdef SCTP 71 #include <netinet/sctp_crc32.h> 72 #endif 73 74 #include <security/mac/mac_framework.h> 75 76 /* 77 * Divert sockets 78 */ 79 80 /* 81 * Allocate enough space to hold a full IP packet 82 */ 83 #define DIVSNDQ (65536 + 100) 84 #define DIVRCVQ (65536 + 100) 85 86 /* 87 * Divert sockets work in conjunction with ipfw or other packet filters, 88 * see the divert(4) manpage for features. 89 * Packets are selected by the packet filter and tagged with an 90 * MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by 91 * the packet filter) and information on the matching filter rule for 92 * subsequent reinjection. The divert_port is used to put the packet 93 * on the corresponding divert socket, while the rule number is passed 94 * up (at least partially) as the sin_port in the struct sockaddr. 95 * 96 * Packets written to the divert socket carry in sin_addr a 97 * destination address, and in sin_port the number of the filter rule 98 * after which to continue processing. 99 * If the destination address is INADDR_ANY, the packet is treated as 100 * as outgoing and sent to ip_output(); otherwise it is treated as 101 * incoming and sent to ip_input(). 102 * Further, sin_zero carries some information on the interface, 103 * which can be used in the reinject -- see comments in the code. 104 * 105 * On reinjection, processing in ip_input() and ip_output() 106 * will be exactly the same as for the original packet, except that 107 * packet filter processing will start at the rule number after the one 108 * written in the sin_port (ipfw does not allow a rule #0, so sin_port=0 109 * will apply the entire ruleset to the packet). 110 */ 111 112 /* Internal variables. */ 113 static VNET_DEFINE(struct inpcbhead, divcb); 114 static VNET_DEFINE(struct inpcbinfo, divcbinfo); 115 116 #define V_divcb VNET(divcb) 117 #define V_divcbinfo VNET(divcbinfo) 118 119 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 120 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 121 122 static eventhandler_tag ip_divert_event_tag; 123 124 /* 125 * Initialize divert connection block queue. 126 */ 127 static void 128 div_zone_change(void *tag) 129 { 130 131 uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets); 132 } 133 134 static int 135 div_inpcb_init(void *mem, int size, int flags) 136 { 137 struct inpcb *inp = mem; 138 139 INP_LOCK_INIT(inp, "inp", "divinp"); 140 return (0); 141 } 142 143 static void 144 div_inpcb_fini(void *mem, int size) 145 { 146 struct inpcb *inp = mem; 147 148 INP_LOCK_DESTROY(inp); 149 } 150 151 static void 152 div_init(void) 153 { 154 155 /* 156 * XXX We don't use the hash list for divert IP, but it's easier to 157 * allocate one-entry hash lists than it is to check all over the 158 * place for hashbase == NULL. 159 */ 160 in_pcbinfo_init(&V_divcbinfo, "div", &V_divcb, 1, 1, "divcb", 161 div_inpcb_init, div_inpcb_fini, 0, IPI_HASHFIELDS_NONE); 162 } 163 164 static void 165 div_destroy(void) 166 { 167 168 in_pcbinfo_destroy(&V_divcbinfo); 169 } 170 171 /* 172 * IPPROTO_DIVERT is not in the real IP protocol number space; this 173 * function should never be called. Just in case, drop any packets. 174 */ 175 static int 176 div_input(struct mbuf **mp, int *offp, int proto) 177 { 178 struct mbuf *m = *mp; 179 180 KMOD_IPSTAT_INC(ips_noproto); 181 m_freem(m); 182 return (IPPROTO_DONE); 183 } 184 185 /* 186 * Divert a packet by passing it up to the divert socket at port 'port'. 187 * 188 * Setup generic address and protocol structures for div_input routine, 189 * then pass them along with mbuf chain. 190 */ 191 static void 192 divert_packet(struct mbuf *m, int incoming) 193 { 194 struct ip *ip; 195 struct inpcb *inp; 196 struct socket *sa; 197 u_int16_t nport; 198 struct sockaddr_in divsrc; 199 struct m_tag *mtag; 200 201 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 202 if (mtag == NULL) { 203 m_freem(m); 204 return; 205 } 206 /* Assure header */ 207 if (m->m_len < sizeof(struct ip) && 208 (m = m_pullup(m, sizeof(struct ip))) == NULL) 209 return; 210 ip = mtod(m, struct ip *); 211 212 /* Delayed checksums are currently not compatible with divert. */ 213 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 214 in_delayed_cksum(m); 215 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 216 } 217 #ifdef SCTP 218 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 219 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 220 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 221 } 222 #endif 223 bzero(&divsrc, sizeof(divsrc)); 224 divsrc.sin_len = sizeof(divsrc); 225 divsrc.sin_family = AF_INET; 226 /* record matching rule, in host format */ 227 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 228 /* 229 * Record receive interface address, if any. 230 * But only for incoming packets. 231 */ 232 if (incoming) { 233 struct ifaddr *ifa; 234 struct ifnet *ifp; 235 236 /* Sanity check */ 237 M_ASSERTPKTHDR(m); 238 239 /* Find IP address for receive interface */ 240 ifp = m->m_pkthdr.rcvif; 241 if_addr_rlock(ifp); 242 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 243 if (ifa->ifa_addr->sa_family != AF_INET) 244 continue; 245 divsrc.sin_addr = 246 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 247 break; 248 } 249 if_addr_runlock(ifp); 250 } 251 /* 252 * Record the incoming interface name whenever we have one. 253 */ 254 if (m->m_pkthdr.rcvif) { 255 /* 256 * Hide the actual interface name in there in the 257 * sin_zero array. XXX This needs to be moved to a 258 * different sockaddr type for divert, e.g. 259 * sockaddr_div with multiple fields like 260 * sockaddr_dl. Presently we have only 7 bytes 261 * but that will do for now as most interfaces 262 * are 4 or less + 2 or less bytes for unit. 263 * There is probably a faster way of doing this, 264 * possibly taking it from the sockaddr_dl on the iface. 265 * This solves the problem of a P2P link and a LAN interface 266 * having the same address, which can result in the wrong 267 * interface being assigned to the packet when fed back 268 * into the divert socket. Theoretically if the daemon saves 269 * and re-uses the sockaddr_in as suggested in the man pages, 270 * this iface name will come along for the ride. 271 * (see div_output for the other half of this.) 272 */ 273 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 274 sizeof(divsrc.sin_zero)); 275 } 276 277 /* Put packet on socket queue, if any */ 278 sa = NULL; 279 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 280 INP_INFO_RLOCK(&V_divcbinfo); 281 LIST_FOREACH(inp, &V_divcb, inp_list) { 282 /* XXX why does only one socket match? */ 283 if (inp->inp_lport == nport) { 284 INP_RLOCK(inp); 285 sa = inp->inp_socket; 286 SOCKBUF_LOCK(&sa->so_rcv); 287 if (sbappendaddr_locked(&sa->so_rcv, 288 (struct sockaddr *)&divsrc, m, 289 (struct mbuf *)0) == 0) { 290 SOCKBUF_UNLOCK(&sa->so_rcv); 291 sa = NULL; /* force mbuf reclaim below */ 292 } else 293 sorwakeup_locked(sa); 294 INP_RUNLOCK(inp); 295 break; 296 } 297 } 298 INP_INFO_RUNLOCK(&V_divcbinfo); 299 if (sa == NULL) { 300 m_freem(m); 301 KMOD_IPSTAT_INC(ips_noproto); 302 KMOD_IPSTAT_DEC(ips_delivered); 303 } 304 } 305 306 /* 307 * Deliver packet back into the IP processing machinery. 308 * 309 * If no address specified, or address is 0.0.0.0, send to ip_output(); 310 * otherwise, send to ip_input() and mark as having been received on 311 * the interface with that address. 312 */ 313 static int 314 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 315 struct mbuf *control) 316 { 317 struct ip *const ip = mtod(m, struct ip *); 318 struct m_tag *mtag; 319 struct ipfw_rule_ref *dt; 320 int error = 0; 321 322 /* 323 * An mbuf may hasn't come from userland, but we pretend 324 * that it has. 325 */ 326 m->m_pkthdr.rcvif = NULL; 327 m->m_nextpkt = NULL; 328 M_SETFIB(m, so->so_fibnum); 329 330 if (control) 331 m_freem(control); /* XXX */ 332 333 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 334 if (mtag == NULL) { 335 /* this should be normal */ 336 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 337 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 338 if (mtag == NULL) { 339 error = ENOBUFS; 340 goto cantsend; 341 } 342 m_tag_prepend(m, mtag); 343 } 344 dt = (struct ipfw_rule_ref *)(mtag+1); 345 346 /* Loopback avoidance and state recovery */ 347 if (sin) { 348 int i; 349 350 /* set the starting point. We provide a non-zero slot, 351 * but a non_matching chain_id to skip that info and use 352 * the rulenum/rule_id. 353 */ 354 dt->slot = 1; /* dummy, chain_id is invalid */ 355 dt->chain_id = 0; 356 dt->rulenum = sin->sin_port+1; /* host format ? */ 357 dt->rule_id = 0; 358 /* 359 * Find receive interface with the given name, stuffed 360 * (if it exists) in the sin_zero[] field. 361 * The name is user supplied data so don't trust its size 362 * or that it is zero terminated. 363 */ 364 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 365 ; 366 if ( i > 0 && i < sizeof(sin->sin_zero)) 367 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 368 } 369 370 /* Reinject packet into the system as incoming or outgoing */ 371 if (!sin || sin->sin_addr.s_addr == 0) { 372 struct mbuf *options = NULL; 373 struct inpcb *inp; 374 375 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 376 inp = sotoinpcb(so); 377 INP_RLOCK(inp); 378 switch (ip->ip_v) { 379 case IPVERSION: 380 /* 381 * Don't allow both user specified and setsockopt 382 * options, and don't allow packet length sizes that 383 * will crash. 384 */ 385 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 386 inp->inp_options != NULL) || 387 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 388 error = EINVAL; 389 INP_RUNLOCK(inp); 390 goto cantsend; 391 } 392 break; 393 #ifdef INET6 394 case IPV6_VERSION >> 4: 395 { 396 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 397 398 /* Don't allow packet length sizes that will crash */ 399 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 400 error = EINVAL; 401 INP_RUNLOCK(inp); 402 goto cantsend; 403 } 404 break; 405 } 406 #endif 407 default: 408 error = EINVAL; 409 INP_RUNLOCK(inp); 410 goto cantsend; 411 } 412 413 /* Send packet to output processing */ 414 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 415 416 #ifdef MAC 417 mac_inpcb_create_mbuf(inp, m); 418 #endif 419 /* 420 * Get ready to inject the packet into ip_output(). 421 * Just in case socket options were specified on the 422 * divert socket, we duplicate them. This is done 423 * to avoid having to hold the PCB locks over the call 424 * to ip_output(), as doing this results in a number of 425 * lock ordering complexities. 426 * 427 * Note that we set the multicast options argument for 428 * ip_output() to NULL since it should be invariant that 429 * they are not present. 430 */ 431 KASSERT(inp->inp_moptions == NULL, 432 ("multicast options set on a divert socket")); 433 /* 434 * XXXCSJP: It is unclear to me whether or not it makes 435 * sense for divert sockets to have options. However, 436 * for now we will duplicate them with the INP locks 437 * held so we can use them in ip_output() without 438 * requring a reference to the pcb. 439 */ 440 if (inp->inp_options != NULL) { 441 options = m_dup(inp->inp_options, M_NOWAIT); 442 if (options == NULL) { 443 INP_RUNLOCK(inp); 444 error = ENOBUFS; 445 goto cantsend; 446 } 447 } 448 INP_RUNLOCK(inp); 449 450 switch (ip->ip_v) { 451 case IPVERSION: 452 error = ip_output(m, options, NULL, 453 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 454 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 455 break; 456 #ifdef INET6 457 case IPV6_VERSION >> 4: 458 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 459 break; 460 #endif 461 } 462 if (options != NULL) 463 m_freem(options); 464 } else { 465 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 466 if (m->m_pkthdr.rcvif == NULL) { 467 /* 468 * No luck with the name, check by IP address. 469 * Clear the port and the ifname to make sure 470 * there are no distractions for ifa_ifwithaddr. 471 */ 472 struct ifaddr *ifa; 473 474 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 475 sin->sin_port = 0; 476 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 477 if (ifa == NULL) { 478 error = EADDRNOTAVAIL; 479 goto cantsend; 480 } 481 m->m_pkthdr.rcvif = ifa->ifa_ifp; 482 ifa_free(ifa); 483 } 484 #ifdef MAC 485 mac_socket_create_mbuf(so, m); 486 #endif 487 /* Send packet to input processing via netisr */ 488 switch (ip->ip_v) { 489 case IPVERSION: 490 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 491 break; 492 #ifdef INET6 493 case IPV6_VERSION >> 4: 494 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 495 break; 496 #endif 497 default: 498 error = EINVAL; 499 goto cantsend; 500 } 501 } 502 503 return (error); 504 505 cantsend: 506 m_freem(m); 507 return (error); 508 } 509 510 static int 511 div_attach(struct socket *so, int proto, struct thread *td) 512 { 513 struct inpcb *inp; 514 int error; 515 516 inp = sotoinpcb(so); 517 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 518 if (td != NULL) { 519 error = priv_check(td, PRIV_NETINET_DIVERT); 520 if (error) 521 return (error); 522 } 523 error = soreserve(so, div_sendspace, div_recvspace); 524 if (error) 525 return error; 526 INP_INFO_WLOCK(&V_divcbinfo); 527 error = in_pcballoc(so, &V_divcbinfo); 528 if (error) { 529 INP_INFO_WUNLOCK(&V_divcbinfo); 530 return error; 531 } 532 inp = (struct inpcb *)so->so_pcb; 533 INP_INFO_WUNLOCK(&V_divcbinfo); 534 inp->inp_ip_p = proto; 535 inp->inp_vflag |= INP_IPV4; 536 inp->inp_flags |= INP_HDRINCL; 537 INP_WUNLOCK(inp); 538 return 0; 539 } 540 541 static void 542 div_detach(struct socket *so) 543 { 544 struct inpcb *inp; 545 546 inp = sotoinpcb(so); 547 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 548 INP_INFO_WLOCK(&V_divcbinfo); 549 INP_WLOCK(inp); 550 in_pcbdetach(inp); 551 in_pcbfree(inp); 552 INP_INFO_WUNLOCK(&V_divcbinfo); 553 } 554 555 static int 556 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 557 { 558 struct inpcb *inp; 559 int error; 560 561 inp = sotoinpcb(so); 562 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 563 /* in_pcbbind assumes that nam is a sockaddr_in 564 * and in_pcbbind requires a valid address. Since divert 565 * sockets don't we need to make sure the address is 566 * filled in properly. 567 * XXX -- divert should not be abusing in_pcbind 568 * and should probably have its own family. 569 */ 570 if (nam->sa_family != AF_INET) 571 return EAFNOSUPPORT; 572 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 573 INP_INFO_WLOCK(&V_divcbinfo); 574 INP_WLOCK(inp); 575 INP_HASH_WLOCK(&V_divcbinfo); 576 error = in_pcbbind(inp, nam, td->td_ucred); 577 INP_HASH_WUNLOCK(&V_divcbinfo); 578 INP_WUNLOCK(inp); 579 INP_INFO_WUNLOCK(&V_divcbinfo); 580 return error; 581 } 582 583 static int 584 div_shutdown(struct socket *so) 585 { 586 struct inpcb *inp; 587 588 inp = sotoinpcb(so); 589 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 590 INP_WLOCK(inp); 591 socantsendmore(so); 592 INP_WUNLOCK(inp); 593 return 0; 594 } 595 596 static int 597 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 598 struct mbuf *control, struct thread *td) 599 { 600 601 /* Packet must have a header (but that's about it) */ 602 if (m->m_len < sizeof (struct ip) && 603 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 604 KMOD_IPSTAT_INC(ips_toosmall); 605 m_freem(m); 606 return EINVAL; 607 } 608 609 /* Send packet */ 610 return div_output(so, m, (struct sockaddr_in *)nam, control); 611 } 612 613 static void 614 div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 615 { 616 struct in_addr faddr; 617 618 faddr = ((struct sockaddr_in *)sa)->sin_addr; 619 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 620 return; 621 if (PRC_IS_REDIRECT(cmd)) 622 return; 623 } 624 625 static int 626 div_pcblist(SYSCTL_HANDLER_ARGS) 627 { 628 int error, i, n; 629 struct inpcb *inp, **inp_list; 630 inp_gen_t gencnt; 631 struct xinpgen xig; 632 633 /* 634 * The process of preparing the TCB list is too time-consuming and 635 * resource-intensive to repeat twice on every request. 636 */ 637 if (req->oldptr == 0) { 638 n = V_divcbinfo.ipi_count; 639 n += imax(n / 8, 10); 640 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 641 return 0; 642 } 643 644 if (req->newptr != 0) 645 return EPERM; 646 647 /* 648 * OK, now we're committed to doing something. 649 */ 650 INP_INFO_RLOCK(&V_divcbinfo); 651 gencnt = V_divcbinfo.ipi_gencnt; 652 n = V_divcbinfo.ipi_count; 653 INP_INFO_RUNLOCK(&V_divcbinfo); 654 655 error = sysctl_wire_old_buffer(req, 656 2 * sizeof(xig) + n*sizeof(struct xinpcb)); 657 if (error != 0) 658 return (error); 659 660 xig.xig_len = sizeof xig; 661 xig.xig_count = n; 662 xig.xig_gen = gencnt; 663 xig.xig_sogen = so_gencnt; 664 error = SYSCTL_OUT(req, &xig, sizeof xig); 665 if (error) 666 return error; 667 668 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 669 if (inp_list == NULL) 670 return ENOMEM; 671 672 INP_INFO_RLOCK(&V_divcbinfo); 673 for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n; 674 inp = LIST_NEXT(inp, inp_list)) { 675 INP_WLOCK(inp); 676 if (inp->inp_gencnt <= gencnt && 677 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 678 in_pcbref(inp); 679 inp_list[i++] = inp; 680 } 681 INP_WUNLOCK(inp); 682 } 683 INP_INFO_RUNLOCK(&V_divcbinfo); 684 n = i; 685 686 error = 0; 687 for (i = 0; i < n; i++) { 688 inp = inp_list[i]; 689 INP_RLOCK(inp); 690 if (inp->inp_gencnt <= gencnt) { 691 struct xinpcb xi; 692 bzero(&xi, sizeof(xi)); 693 xi.xi_len = sizeof xi; 694 /* XXX should avoid extra copy */ 695 bcopy(inp, &xi.xi_inp, sizeof *inp); 696 if (inp->inp_socket) 697 sotoxsocket(inp->inp_socket, &xi.xi_socket); 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 #ifdef VIMAGE 759 .pr_destroy = div_destroy, 760 #endif 761 .pr_usrreqs = &div_usrreqs 762 }; 763 764 static int 765 div_modevent(module_t mod, int type, void *unused) 766 { 767 int err = 0; 768 #ifndef VIMAGE 769 int n; 770 #endif 771 772 switch (type) { 773 case MOD_LOAD: 774 /* 775 * Protocol will be initialized by pf_proto_register(). 776 * We don't have to register ip_protox because we are not 777 * a true IP protocol that goes over the wire. 778 */ 779 err = pf_proto_register(PF_INET, &div_protosw); 780 if (err != 0) 781 return (err); 782 ip_divert_ptr = divert_packet; 783 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 784 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 785 break; 786 case MOD_QUIESCE: 787 /* 788 * IPDIVERT may normally not be unloaded because of the 789 * potential race conditions. Tell kldunload we can't be 790 * unloaded unless the unload is forced. 791 */ 792 err = EPERM; 793 break; 794 case MOD_UNLOAD: 795 #ifdef VIMAGE 796 err = EPERM; 797 break; 798 #else 799 /* 800 * Forced unload. 801 * 802 * Module ipdivert can only be unloaded if no sockets are 803 * connected. Maybe this can be changed later to forcefully 804 * disconnect any open sockets. 805 * 806 * XXXRW: Note that there is a slight race here, as a new 807 * socket open request could be spinning on the lock and then 808 * we destroy the lock. 809 */ 810 INP_INFO_WLOCK(&V_divcbinfo); 811 n = V_divcbinfo.ipi_count; 812 if (n != 0) { 813 err = EBUSY; 814 INP_INFO_WUNLOCK(&V_divcbinfo); 815 break; 816 } 817 ip_divert_ptr = NULL; 818 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 819 INP_INFO_WUNLOCK(&V_divcbinfo); 820 div_destroy(); 821 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 822 break; 823 #endif /* !VIMAGE */ 824 default: 825 err = EOPNOTSUPP; 826 break; 827 } 828 return err; 829 } 830 831 static moduledata_t ipdivertmod = { 832 "ipdivert", 833 div_modevent, 834 0 835 }; 836 837 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 838 MODULE_DEPEND(ipdivert, ipfw, 3, 3, 3); 839 MODULE_VERSION(ipdivert, 1); 840