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 #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 #include "opt_inet6.h" 41 42 #include <sys/param.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/mbuf.h> 47 #include <sys/module.h> 48 #include <sys/kernel.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/protosw.h> 52 #include <sys/socket.h> 53 #include <sys/socketvar.h> 54 #include <sys/sysctl.h> 55 #include <net/vnet.h> 56 57 #include <net/if.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 ip->ip_len = ntohs(ip->ip_len); 214 in_delayed_cksum(m); 215 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 216 ip->ip_len = htons(ip->ip_len); 217 } 218 #ifdef SCTP 219 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 220 ip->ip_len = ntohs(ip->ip_len); 221 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 222 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 223 ip->ip_len = htons(ip->ip_len); 224 } 225 #endif 226 bzero(&divsrc, sizeof(divsrc)); 227 divsrc.sin_len = sizeof(divsrc); 228 divsrc.sin_family = AF_INET; 229 /* record matching rule, in host format */ 230 divsrc.sin_port = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 231 /* 232 * Record receive interface address, if any. 233 * But only for incoming packets. 234 */ 235 if (incoming) { 236 struct ifaddr *ifa; 237 struct ifnet *ifp; 238 239 /* Sanity check */ 240 M_ASSERTPKTHDR(m); 241 242 /* Find IP address for receive interface */ 243 ifp = m->m_pkthdr.rcvif; 244 if_addr_rlock(ifp); 245 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 246 if (ifa->ifa_addr->sa_family != AF_INET) 247 continue; 248 divsrc.sin_addr = 249 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 250 break; 251 } 252 if_addr_runlock(ifp); 253 } 254 /* 255 * Record the incoming interface name whenever we have one. 256 */ 257 if (m->m_pkthdr.rcvif) { 258 /* 259 * Hide the actual interface name in there in the 260 * sin_zero array. XXX This needs to be moved to a 261 * different sockaddr type for divert, e.g. 262 * sockaddr_div with multiple fields like 263 * sockaddr_dl. Presently we have only 7 bytes 264 * but that will do for now as most interfaces 265 * are 4 or less + 2 or less bytes for unit. 266 * There is probably a faster way of doing this, 267 * possibly taking it from the sockaddr_dl on the iface. 268 * This solves the problem of a P2P link and a LAN interface 269 * having the same address, which can result in the wrong 270 * interface being assigned to the packet when fed back 271 * into the divert socket. Theoretically if the daemon saves 272 * and re-uses the sockaddr_in as suggested in the man pages, 273 * this iface name will come along for the ride. 274 * (see div_output for the other half of this.) 275 */ 276 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 277 sizeof(divsrc.sin_zero)); 278 } 279 280 /* Put packet on socket queue, if any */ 281 sa = NULL; 282 nport = htons((u_int16_t)(((struct ipfw_rule_ref *)(mtag+1))->info)); 283 INP_INFO_RLOCK(&V_divcbinfo); 284 LIST_FOREACH(inp, &V_divcb, inp_list) { 285 /* XXX why does only one socket match? */ 286 if (inp->inp_lport == nport) { 287 INP_RLOCK(inp); 288 sa = inp->inp_socket; 289 SOCKBUF_LOCK(&sa->so_rcv); 290 if (sbappendaddr_locked(&sa->so_rcv, 291 (struct sockaddr *)&divsrc, m, 292 (struct mbuf *)0) == 0) { 293 SOCKBUF_UNLOCK(&sa->so_rcv); 294 sa = NULL; /* force mbuf reclaim below */ 295 } else 296 sorwakeup_locked(sa); 297 INP_RUNLOCK(inp); 298 break; 299 } 300 } 301 INP_INFO_RUNLOCK(&V_divcbinfo); 302 if (sa == NULL) { 303 m_freem(m); 304 KMOD_IPSTAT_INC(ips_noproto); 305 KMOD_IPSTAT_DEC(ips_delivered); 306 } 307 } 308 309 /* 310 * Deliver packet back into the IP processing machinery. 311 * 312 * If no address specified, or address is 0.0.0.0, send to ip_output(); 313 * otherwise, send to ip_input() and mark as having been received on 314 * the interface with that address. 315 */ 316 static int 317 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin, 318 struct mbuf *control) 319 { 320 struct ip *const ip = mtod(m, struct ip *); 321 struct m_tag *mtag; 322 struct ipfw_rule_ref *dt; 323 int error = 0; 324 325 /* 326 * An mbuf may hasn't come from userland, but we pretend 327 * that it has. 328 */ 329 m->m_pkthdr.rcvif = NULL; 330 m->m_nextpkt = NULL; 331 M_SETFIB(m, so->so_fibnum); 332 333 if (control) 334 m_freem(control); /* XXX */ 335 336 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 337 if (mtag == NULL) { 338 /* this should be normal */ 339 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 340 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 341 if (mtag == NULL) { 342 error = ENOBUFS; 343 goto cantsend; 344 } 345 m_tag_prepend(m, mtag); 346 } 347 dt = (struct ipfw_rule_ref *)(mtag+1); 348 349 /* Loopback avoidance and state recovery */ 350 if (sin) { 351 int i; 352 353 /* set the starting point. We provide a non-zero slot, 354 * but a non_matching chain_id to skip that info and use 355 * the rulenum/rule_id. 356 */ 357 dt->slot = 1; /* dummy, chain_id is invalid */ 358 dt->chain_id = 0; 359 dt->rulenum = sin->sin_port+1; /* host format ? */ 360 dt->rule_id = 0; 361 /* 362 * Find receive interface with the given name, stuffed 363 * (if it exists) in the sin_zero[] field. 364 * The name is user supplied data so don't trust its size 365 * or that it is zero terminated. 366 */ 367 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 368 ; 369 if ( i > 0 && i < sizeof(sin->sin_zero)) 370 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 371 } 372 373 /* Reinject packet into the system as incoming or outgoing */ 374 if (!sin || sin->sin_addr.s_addr == 0) { 375 struct mbuf *options = NULL; 376 struct inpcb *inp; 377 378 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 379 inp = sotoinpcb(so); 380 INP_RLOCK(inp); 381 switch (ip->ip_v) { 382 case IPVERSION: 383 /* 384 * Don't allow both user specified and setsockopt 385 * options, and don't allow packet length sizes that 386 * will crash. 387 */ 388 if ((((ip->ip_hl << 2) != sizeof(struct ip)) && 389 inp->inp_options != NULL) || 390 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 391 error = EINVAL; 392 INP_RUNLOCK(inp); 393 goto cantsend; 394 } 395 396 /* Convert fields to host order for ip_output() */ 397 ip->ip_len = ntohs(ip->ip_len); 398 ip->ip_off = ntohs(ip->ip_off); 399 break; 400 #ifdef INET6 401 case IPV6_VERSION >> 4: 402 { 403 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 404 405 /* Don't allow packet length sizes that will crash */ 406 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 407 error = EINVAL; 408 INP_RUNLOCK(inp); 409 goto cantsend; 410 } 411 412 ip6->ip6_plen = ntohs(ip6->ip6_plen); 413 break; 414 } 415 #endif 416 default: 417 error = EINVAL; 418 INP_RUNLOCK(inp); 419 goto cantsend; 420 } 421 422 /* Send packet to output processing */ 423 KMOD_IPSTAT_INC(ips_rawout); /* XXX */ 424 425 #ifdef MAC 426 mac_inpcb_create_mbuf(inp, m); 427 #endif 428 /* 429 * Get ready to inject the packet into ip_output(). 430 * Just in case socket options were specified on the 431 * divert socket, we duplicate them. This is done 432 * to avoid having to hold the PCB locks over the call 433 * to ip_output(), as doing this results in a number of 434 * lock ordering complexities. 435 * 436 * Note that we set the multicast options argument for 437 * ip_output() to NULL since it should be invariant that 438 * they are not present. 439 */ 440 KASSERT(inp->inp_moptions == NULL, 441 ("multicast options set on a divert socket")); 442 /* 443 * XXXCSJP: It is unclear to me whether or not it makes 444 * sense for divert sockets to have options. However, 445 * for now we will duplicate them with the INP locks 446 * held so we can use them in ip_output() without 447 * requring a reference to the pcb. 448 */ 449 if (inp->inp_options != NULL) { 450 options = m_dup(inp->inp_options, M_NOWAIT); 451 if (options == NULL) { 452 INP_RUNLOCK(inp); 453 error = ENOBUFS; 454 goto cantsend; 455 } 456 } 457 INP_RUNLOCK(inp); 458 459 switch (ip->ip_v) { 460 case IPVERSION: 461 error = ip_output(m, options, NULL, 462 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 463 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 464 break; 465 #ifdef INET6 466 case IPV6_VERSION >> 4: 467 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 468 break; 469 #endif 470 } 471 if (options != NULL) 472 m_freem(options); 473 } else { 474 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 475 if (m->m_pkthdr.rcvif == NULL) { 476 /* 477 * No luck with the name, check by IP address. 478 * Clear the port and the ifname to make sure 479 * there are no distractions for ifa_ifwithaddr. 480 */ 481 struct ifaddr *ifa; 482 483 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 484 sin->sin_port = 0; 485 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 486 if (ifa == NULL) { 487 error = EADDRNOTAVAIL; 488 goto cantsend; 489 } 490 m->m_pkthdr.rcvif = ifa->ifa_ifp; 491 ifa_free(ifa); 492 } 493 #ifdef MAC 494 mac_socket_create_mbuf(so, m); 495 #endif 496 /* Send packet to input processing via netisr */ 497 switch (ip->ip_v) { 498 case IPVERSION: 499 netisr_queue_src(NETISR_IP, (uintptr_t)so, m); 500 break; 501 #ifdef INET6 502 case IPV6_VERSION >> 4: 503 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m); 504 break; 505 #endif 506 default: 507 error = EINVAL; 508 goto cantsend; 509 } 510 } 511 512 return (error); 513 514 cantsend: 515 m_freem(m); 516 return (error); 517 } 518 519 static int 520 div_attach(struct socket *so, int proto, struct thread *td) 521 { 522 struct inpcb *inp; 523 int error; 524 525 inp = sotoinpcb(so); 526 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 527 if (td != NULL) { 528 error = priv_check(td, PRIV_NETINET_DIVERT); 529 if (error) 530 return (error); 531 } 532 error = soreserve(so, div_sendspace, div_recvspace); 533 if (error) 534 return error; 535 INP_INFO_WLOCK(&V_divcbinfo); 536 error = in_pcballoc(so, &V_divcbinfo); 537 if (error) { 538 INP_INFO_WUNLOCK(&V_divcbinfo); 539 return error; 540 } 541 inp = (struct inpcb *)so->so_pcb; 542 INP_INFO_WUNLOCK(&V_divcbinfo); 543 inp->inp_ip_p = proto; 544 inp->inp_vflag |= INP_IPV4; 545 inp->inp_flags |= INP_HDRINCL; 546 INP_WUNLOCK(inp); 547 return 0; 548 } 549 550 static void 551 div_detach(struct socket *so) 552 { 553 struct inpcb *inp; 554 555 inp = sotoinpcb(so); 556 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 557 INP_INFO_WLOCK(&V_divcbinfo); 558 INP_WLOCK(inp); 559 in_pcbdetach(inp); 560 in_pcbfree(inp); 561 INP_INFO_WUNLOCK(&V_divcbinfo); 562 } 563 564 static int 565 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 566 { 567 struct inpcb *inp; 568 int error; 569 570 inp = sotoinpcb(so); 571 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 572 /* in_pcbbind assumes that nam is a sockaddr_in 573 * and in_pcbbind requires a valid address. Since divert 574 * sockets don't we need to make sure the address is 575 * filled in properly. 576 * XXX -- divert should not be abusing in_pcbind 577 * and should probably have its own family. 578 */ 579 if (nam->sa_family != AF_INET) 580 return EAFNOSUPPORT; 581 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 582 INP_INFO_WLOCK(&V_divcbinfo); 583 INP_WLOCK(inp); 584 INP_HASH_WLOCK(&V_divcbinfo); 585 error = in_pcbbind(inp, nam, td->td_ucred); 586 INP_HASH_WUNLOCK(&V_divcbinfo); 587 INP_WUNLOCK(inp); 588 INP_INFO_WUNLOCK(&V_divcbinfo); 589 return error; 590 } 591 592 static int 593 div_shutdown(struct socket *so) 594 { 595 struct inpcb *inp; 596 597 inp = sotoinpcb(so); 598 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 599 INP_WLOCK(inp); 600 socantsendmore(so); 601 INP_WUNLOCK(inp); 602 return 0; 603 } 604 605 static int 606 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 607 struct mbuf *control, struct thread *td) 608 { 609 610 /* Packet must have a header (but that's about it) */ 611 if (m->m_len < sizeof (struct ip) && 612 (m = m_pullup(m, sizeof (struct ip))) == 0) { 613 KMOD_IPSTAT_INC(ips_toosmall); 614 m_freem(m); 615 return EINVAL; 616 } 617 618 /* Send packet */ 619 return div_output(so, m, (struct sockaddr_in *)nam, control); 620 } 621 622 static void 623 div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 624 { 625 struct in_addr faddr; 626 627 faddr = ((struct sockaddr_in *)sa)->sin_addr; 628 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 629 return; 630 if (PRC_IS_REDIRECT(cmd)) 631 return; 632 } 633 634 static int 635 div_pcblist(SYSCTL_HANDLER_ARGS) 636 { 637 int error, i, n; 638 struct inpcb *inp, **inp_list; 639 inp_gen_t gencnt; 640 struct xinpgen xig; 641 642 /* 643 * The process of preparing the TCB list is too time-consuming and 644 * resource-intensive to repeat twice on every request. 645 */ 646 if (req->oldptr == 0) { 647 n = V_divcbinfo.ipi_count; 648 n += imax(n / 8, 10); 649 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 650 return 0; 651 } 652 653 if (req->newptr != 0) 654 return EPERM; 655 656 /* 657 * OK, now we're committed to doing something. 658 */ 659 INP_INFO_RLOCK(&V_divcbinfo); 660 gencnt = V_divcbinfo.ipi_gencnt; 661 n = V_divcbinfo.ipi_count; 662 INP_INFO_RUNLOCK(&V_divcbinfo); 663 664 error = sysctl_wire_old_buffer(req, 665 2 * sizeof(xig) + n*sizeof(struct xinpcb)); 666 if (error != 0) 667 return (error); 668 669 xig.xig_len = sizeof xig; 670 xig.xig_count = n; 671 xig.xig_gen = gencnt; 672 xig.xig_sogen = so_gencnt; 673 error = SYSCTL_OUT(req, &xig, sizeof xig); 674 if (error) 675 return error; 676 677 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 678 if (inp_list == 0) 679 return ENOMEM; 680 681 INP_INFO_RLOCK(&V_divcbinfo); 682 for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n; 683 inp = LIST_NEXT(inp, inp_list)) { 684 INP_WLOCK(inp); 685 if (inp->inp_gencnt <= gencnt && 686 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 687 in_pcbref(inp); 688 inp_list[i++] = inp; 689 } 690 INP_WUNLOCK(inp); 691 } 692 INP_INFO_RUNLOCK(&V_divcbinfo); 693 n = i; 694 695 error = 0; 696 for (i = 0; i < n; i++) { 697 inp = inp_list[i]; 698 INP_RLOCK(inp); 699 if (inp->inp_gencnt <= gencnt) { 700 struct xinpcb xi; 701 bzero(&xi, sizeof(xi)); 702 xi.xi_len = sizeof xi; 703 /* XXX should avoid extra copy */ 704 bcopy(inp, &xi.xi_inp, sizeof *inp); 705 if (inp->inp_socket) 706 sotoxsocket(inp->inp_socket, &xi.xi_socket); 707 INP_RUNLOCK(inp); 708 error = SYSCTL_OUT(req, &xi, sizeof xi); 709 } else 710 INP_RUNLOCK(inp); 711 } 712 INP_INFO_WLOCK(&V_divcbinfo); 713 for (i = 0; i < n; i++) { 714 inp = inp_list[i]; 715 INP_RLOCK(inp); 716 if (!in_pcbrele_rlocked(inp)) 717 INP_RUNLOCK(inp); 718 } 719 INP_INFO_WUNLOCK(&V_divcbinfo); 720 721 if (!error) { 722 /* 723 * Give the user an updated idea of our state. 724 * If the generation differs from what we told 725 * her before, she knows that something happened 726 * while we were processing this request, and it 727 * might be necessary to retry. 728 */ 729 INP_INFO_RLOCK(&V_divcbinfo); 730 xig.xig_gen = V_divcbinfo.ipi_gencnt; 731 xig.xig_sogen = so_gencnt; 732 xig.xig_count = V_divcbinfo.ipi_count; 733 INP_INFO_RUNLOCK(&V_divcbinfo); 734 error = SYSCTL_OUT(req, &xig, sizeof xig); 735 } 736 free(inp_list, M_TEMP); 737 return error; 738 } 739 740 #ifdef SYSCTL_NODE 741 static SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, 742 "IPDIVERT"); 743 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 744 NULL, 0, div_pcblist, "S,xinpcb", "List of active divert sockets"); 745 #endif 746 747 struct pr_usrreqs div_usrreqs = { 748 .pru_attach = div_attach, 749 .pru_bind = div_bind, 750 .pru_control = in_control, 751 .pru_detach = div_detach, 752 .pru_peeraddr = in_getpeeraddr, 753 .pru_send = div_send, 754 .pru_shutdown = div_shutdown, 755 .pru_sockaddr = in_getsockaddr, 756 .pru_sosetlabel = in_pcbsosetlabel 757 }; 758 759 struct protosw div_protosw = { 760 .pr_type = SOCK_RAW, 761 .pr_protocol = IPPROTO_DIVERT, 762 .pr_flags = PR_ATOMIC|PR_ADDR, 763 .pr_input = div_input, 764 .pr_ctlinput = div_ctlinput, 765 .pr_ctloutput = ip_ctloutput, 766 .pr_init = div_init, 767 #ifdef VIMAGE 768 .pr_destroy = div_destroy, 769 #endif 770 .pr_usrreqs = &div_usrreqs 771 }; 772 773 static int 774 div_modevent(module_t mod, int type, void *unused) 775 { 776 int err = 0; 777 #ifndef VIMAGE 778 int n; 779 #endif 780 781 switch (type) { 782 case MOD_LOAD: 783 /* 784 * Protocol will be initialized by pf_proto_register(). 785 * We don't have to register ip_protox because we are not 786 * a true IP protocol that goes over the wire. 787 */ 788 err = pf_proto_register(PF_INET, &div_protosw); 789 if (err != 0) 790 return (err); 791 ip_divert_ptr = divert_packet; 792 ip_divert_event_tag = EVENTHANDLER_REGISTER(maxsockets_change, 793 div_zone_change, NULL, EVENTHANDLER_PRI_ANY); 794 break; 795 case MOD_QUIESCE: 796 /* 797 * IPDIVERT may normally not be unloaded because of the 798 * potential race conditions. Tell kldunload we can't be 799 * unloaded unless the unload is forced. 800 */ 801 err = EPERM; 802 break; 803 case MOD_UNLOAD: 804 #ifdef VIMAGE 805 err = EPERM; 806 break; 807 #else 808 /* 809 * Forced unload. 810 * 811 * Module ipdivert can only be unloaded if no sockets are 812 * connected. Maybe this can be changed later to forcefully 813 * disconnect any open sockets. 814 * 815 * XXXRW: Note that there is a slight race here, as a new 816 * socket open request could be spinning on the lock and then 817 * we destroy the lock. 818 */ 819 INP_INFO_WLOCK(&V_divcbinfo); 820 n = V_divcbinfo.ipi_count; 821 if (n != 0) { 822 err = EBUSY; 823 INP_INFO_WUNLOCK(&V_divcbinfo); 824 break; 825 } 826 ip_divert_ptr = NULL; 827 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 828 INP_INFO_WUNLOCK(&V_divcbinfo); 829 div_destroy(); 830 EVENTHANDLER_DEREGISTER(maxsockets_change, ip_divert_event_tag); 831 break; 832 #endif /* !VIMAGE */ 833 default: 834 err = EOPNOTSUPP; 835 break; 836 } 837 return err; 838 } 839 840 static moduledata_t ipdivertmod = { 841 "ipdivert", 842 div_modevent, 843 0 844 }; 845 846 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 847 MODULE_DEPEND(ipdivert, ipfw, 2, 2, 2); 848 MODULE_VERSION(ipdivert, 1); 849