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 * $FreeBSD$ 30 */ 31 32 #if !defined(KLD_MODULE) 33 #include "opt_inet.h" 34 #include "opt_ipfw.h" 35 #include "opt_mac.h" 36 #ifndef INET 37 #error "IPDIVERT requires INET." 38 #endif 39 #ifndef IPFIREWALL 40 #error "IPDIVERT requires IPFIREWALL" 41 #endif 42 #endif 43 44 #include <sys/param.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/module.h> 50 #include <sys/kernel.h> 51 #include <sys/priv.h> 52 #include <sys/proc.h> 53 #include <sys/protosw.h> 54 #include <sys/signalvar.h> 55 #include <sys/socket.h> 56 #include <sys/socketvar.h> 57 #include <sys/sx.h> 58 #include <sys/sysctl.h> 59 #include <sys/systm.h> 60 61 #include <vm/uma.h> 62 63 #include <net/if.h> 64 #include <net/route.h> 65 66 #include <netinet/in.h> 67 #include <netinet/in_pcb.h> 68 #include <netinet/in_systm.h> 69 #include <netinet/in_var.h> 70 #include <netinet/ip.h> 71 #include <netinet/ip_divert.h> 72 #include <netinet/ip_var.h> 73 #include <netinet/ip_fw.h> 74 75 #include <security/mac/mac_framework.h> 76 77 /* 78 * Divert sockets 79 */ 80 81 /* 82 * Allocate enough space to hold a full IP packet 83 */ 84 #define DIVSNDQ (65536 + 100) 85 #define DIVRCVQ (65536 + 100) 86 87 /* 88 * Divert sockets work in conjunction with ipfw, see the divert(4) 89 * manpage for features. 90 * Internally, packets selected by ipfw in ip_input() or ip_output(), 91 * and never diverted before, are passed to the input queue of the 92 * divert socket with a given 'divert_port' number (as specified in 93 * the matching ipfw rule), and they are tagged with a 16 bit cookie 94 * (representing the rule number of the matching ipfw rule), which 95 * is passed to process reading from the socket. 96 * 97 * Packets written to the divert socket are again tagged with a cookie 98 * (usually the same as above) and a destination address. 99 * If the destination address is INADDR_ANY then the packet is 100 * treated as outgoing and sent to ip_output(), otherwise it is 101 * treated as incoming and sent to ip_input(). 102 * In both cases, the packet is tagged with the cookie. 103 * 104 * On reinjection, processing in ip_input() and ip_output() 105 * will be exactly the same as for the original packet, except that 106 * ipfw processing will start at the rule number after the one 107 * written in the cookie (so, tagging a packet with a cookie of 0 108 * will cause it to be effectively considered as a standard packet). 109 */ 110 111 /* Internal variables. */ 112 static struct inpcbhead divcb; 113 static struct inpcbinfo divcbinfo; 114 115 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 116 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 117 118 /* 119 * Initialize divert connection block queue. 120 */ 121 static void 122 div_zone_change(void *tag) 123 { 124 125 uma_zone_set_max(divcbinfo.ipi_zone, maxsockets); 126 } 127 128 static int 129 div_inpcb_init(void *mem, int size, int flags) 130 { 131 struct inpcb *inp = mem; 132 133 INP_LOCK_INIT(inp, "inp", "divinp"); 134 return (0); 135 } 136 137 static void 138 div_inpcb_fini(void *mem, int size) 139 { 140 struct inpcb *inp = mem; 141 142 INP_LOCK_DESTROY(inp); 143 } 144 145 void 146 div_init(void) 147 { 148 INP_INFO_LOCK_INIT(&divcbinfo, "div"); 149 LIST_INIT(&divcb); 150 divcbinfo.listhead = &divcb; 151 /* 152 * XXX We don't use the hash list for divert IP, but it's easier 153 * to allocate a one entry hash list than it is to check all 154 * over the place for hashbase == NULL. 155 */ 156 divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask); 157 divcbinfo.porthashbase = hashinit(1, M_PCB, &divcbinfo.porthashmask); 158 divcbinfo.ipi_zone = uma_zcreate("divcb", sizeof(struct inpcb), 159 NULL, NULL, div_inpcb_init, div_inpcb_fini, UMA_ALIGN_PTR, 160 UMA_ZONE_NOFREE); 161 uma_zone_set_max(divcbinfo.ipi_zone, maxsockets); 162 EVENTHANDLER_REGISTER(maxsockets_change, div_zone_change, 163 NULL, EVENTHANDLER_PRI_ANY); 164 } 165 166 /* 167 * IPPROTO_DIVERT is not in the real IP protocol number space; this 168 * function should never be called. Just in case, drop any packets. 169 */ 170 void 171 div_input(struct mbuf *m, int off) 172 { 173 ipstat.ips_noproto++; 174 m_freem(m); 175 } 176 177 /* 178 * Divert a packet by passing it up to the divert socket at port 'port'. 179 * 180 * Setup generic address and protocol structures for div_input routine, 181 * then pass them along with mbuf chain. 182 */ 183 static void 184 divert_packet(struct mbuf *m, int incoming) 185 { 186 struct ip *ip; 187 struct inpcb *inp; 188 struct socket *sa; 189 u_int16_t nport; 190 struct sockaddr_in divsrc; 191 struct m_tag *mtag; 192 193 mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL); 194 if (mtag == NULL) { 195 printf("%s: no divert tag\n", __func__); 196 m_freem(m); 197 return; 198 } 199 /* Assure header */ 200 if (m->m_len < sizeof(struct ip) && 201 (m = m_pullup(m, sizeof(struct ip))) == 0) 202 return; 203 ip = mtod(m, struct ip *); 204 205 /* Delayed checksums are currently not compatible with divert. */ 206 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 207 ip->ip_len = ntohs(ip->ip_len); 208 in_delayed_cksum(m); 209 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 210 ip->ip_len = htons(ip->ip_len); 211 } 212 213 /* 214 * Record receive interface address, if any. 215 * But only for incoming packets. 216 */ 217 bzero(&divsrc, sizeof(divsrc)); 218 divsrc.sin_len = sizeof(divsrc); 219 divsrc.sin_family = AF_INET; 220 divsrc.sin_port = divert_cookie(mtag); /* record matching rule */ 221 if (incoming) { 222 struct ifaddr *ifa; 223 224 /* Sanity check */ 225 M_ASSERTPKTHDR(m); 226 227 /* Find IP address for receive interface */ 228 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) { 229 if (ifa->ifa_addr->sa_family != AF_INET) 230 continue; 231 divsrc.sin_addr = 232 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 233 break; 234 } 235 } 236 /* 237 * Record the incoming interface name whenever we have one. 238 */ 239 if (m->m_pkthdr.rcvif) { 240 /* 241 * Hide the actual interface name in there in the 242 * sin_zero array. XXX This needs to be moved to a 243 * different sockaddr type for divert, e.g. 244 * sockaddr_div with multiple fields like 245 * sockaddr_dl. Presently we have only 7 bytes 246 * but that will do for now as most interfaces 247 * are 4 or less + 2 or less bytes for unit. 248 * There is probably a faster way of doing this, 249 * possibly taking it from the sockaddr_dl on the iface. 250 * This solves the problem of a P2P link and a LAN interface 251 * having the same address, which can result in the wrong 252 * interface being assigned to the packet when fed back 253 * into the divert socket. Theoretically if the daemon saves 254 * and re-uses the sockaddr_in as suggested in the man pages, 255 * this iface name will come along for the ride. 256 * (see div_output for the other half of this.) 257 */ 258 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 259 sizeof(divsrc.sin_zero)); 260 } 261 262 /* Put packet on socket queue, if any */ 263 sa = NULL; 264 nport = htons((u_int16_t)divert_info(mtag)); 265 INP_INFO_RLOCK(&divcbinfo); 266 LIST_FOREACH(inp, &divcb, inp_list) { 267 INP_LOCK(inp); 268 /* XXX why does only one socket match? */ 269 if (inp->inp_lport == nport) { 270 sa = inp->inp_socket; 271 SOCKBUF_LOCK(&sa->so_rcv); 272 if (sbappendaddr_locked(&sa->so_rcv, 273 (struct sockaddr *)&divsrc, m, 274 (struct mbuf *)0) == 0) { 275 SOCKBUF_UNLOCK(&sa->so_rcv); 276 sa = NULL; /* force mbuf reclaim below */ 277 } else 278 sorwakeup_locked(sa); 279 INP_UNLOCK(inp); 280 break; 281 } 282 INP_UNLOCK(inp); 283 } 284 INP_INFO_RUNLOCK(&divcbinfo); 285 if (sa == NULL) { 286 m_freem(m); 287 ipstat.ips_noproto++; 288 ipstat.ips_delivered--; 289 } 290 } 291 292 /* 293 * Deliver packet back into the IP processing machinery. 294 * 295 * If no address specified, or address is 0.0.0.0, send to ip_output(); 296 * otherwise, send to ip_input() and mark as having been received on 297 * the interface with that address. 298 */ 299 static int 300 div_output(struct socket *so, struct mbuf *m, 301 struct sockaddr_in *sin, struct mbuf *control) 302 { 303 struct m_tag *mtag; 304 struct divert_tag *dt; 305 int error = 0; 306 307 /* 308 * An mbuf may hasn't come from userland, but we pretend 309 * that it has. 310 */ 311 m->m_pkthdr.rcvif = NULL; 312 m->m_nextpkt = NULL; 313 314 if (control) 315 m_freem(control); /* XXX */ 316 317 if ((mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL)) == NULL) { 318 mtag = m_tag_get(PACKET_TAG_DIVERT, sizeof(struct divert_tag), 319 M_NOWAIT | M_ZERO); 320 if (mtag == NULL) { 321 error = ENOBUFS; 322 goto cantsend; 323 } 324 dt = (struct divert_tag *)(mtag+1); 325 m_tag_prepend(m, mtag); 326 } else 327 dt = (struct divert_tag *)(mtag+1); 328 329 /* Loopback avoidance and state recovery */ 330 if (sin) { 331 int i; 332 333 dt->cookie = sin->sin_port; 334 /* 335 * Find receive interface with the given name, stuffed 336 * (if it exists) in the sin_zero[] field. 337 * The name is user supplied data so don't trust its size 338 * or that it is zero terminated. 339 */ 340 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 341 ; 342 if ( i > 0 && i < sizeof(sin->sin_zero)) 343 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 344 } 345 346 /* Reinject packet into the system as incoming or outgoing */ 347 if (!sin || sin->sin_addr.s_addr == 0) { 348 struct ip *const ip = mtod(m, struct ip *); 349 struct inpcb *inp; 350 351 dt->info |= IP_FW_DIVERT_OUTPUT_FLAG; 352 INP_INFO_WLOCK(&divcbinfo); 353 inp = sotoinpcb(so); 354 INP_LOCK(inp); 355 /* 356 * Don't allow both user specified and setsockopt options, 357 * and don't allow packet length sizes that will crash 358 */ 359 if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) || 360 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 361 error = EINVAL; 362 m_freem(m); 363 } else { 364 /* Convert fields to host order for ip_output() */ 365 ip->ip_len = ntohs(ip->ip_len); 366 ip->ip_off = ntohs(ip->ip_off); 367 368 /* Send packet to output processing */ 369 ipstat.ips_rawout++; /* XXX */ 370 371 #ifdef MAC 372 mac_create_mbuf_from_inpcb(inp, m); 373 #endif 374 error = ip_output(m, 375 inp->inp_options, NULL, 376 ((so->so_options & SO_DONTROUTE) ? 377 IP_ROUTETOIF : 0) | 378 IP_ALLOWBROADCAST | IP_RAWOUTPUT, 379 inp->inp_moptions, NULL); 380 } 381 INP_UNLOCK(inp); 382 INP_INFO_WUNLOCK(&divcbinfo); 383 } else { 384 dt->info |= IP_FW_DIVERT_LOOPBACK_FLAG; 385 if (m->m_pkthdr.rcvif == NULL) { 386 /* 387 * No luck with the name, check by IP address. 388 * Clear the port and the ifname to make sure 389 * there are no distractions for ifa_ifwithaddr. 390 */ 391 struct ifaddr *ifa; 392 393 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 394 sin->sin_port = 0; 395 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 396 if (ifa == NULL) { 397 error = EADDRNOTAVAIL; 398 goto cantsend; 399 } 400 m->m_pkthdr.rcvif = ifa->ifa_ifp; 401 } 402 #ifdef MAC 403 SOCK_LOCK(so); 404 mac_create_mbuf_from_socket(so, m); 405 SOCK_UNLOCK(so); 406 #endif 407 /* Send packet to input processing */ 408 ip_input(m); 409 } 410 411 return error; 412 413 cantsend: 414 m_freem(m); 415 return error; 416 } 417 418 static int 419 div_attach(struct socket *so, int proto, struct thread *td) 420 { 421 struct inpcb *inp; 422 int error; 423 424 inp = sotoinpcb(so); 425 KASSERT(inp == NULL, ("div_attach: inp != NULL")); 426 if (td != NULL) { 427 error = priv_check(td, PRIV_NETINET_DIVERT); 428 if (error) 429 return (error); 430 } 431 error = soreserve(so, div_sendspace, div_recvspace); 432 if (error) 433 return error; 434 INP_INFO_WLOCK(&divcbinfo); 435 error = in_pcballoc(so, &divcbinfo); 436 if (error) { 437 INP_INFO_WUNLOCK(&divcbinfo); 438 return error; 439 } 440 inp = (struct inpcb *)so->so_pcb; 441 INP_INFO_WUNLOCK(&divcbinfo); 442 inp->inp_ip_p = proto; 443 inp->inp_vflag |= INP_IPV4; 444 inp->inp_flags |= INP_HDRINCL; 445 INP_UNLOCK(inp); 446 return 0; 447 } 448 449 static void 450 div_detach(struct socket *so) 451 { 452 struct inpcb *inp; 453 454 inp = sotoinpcb(so); 455 KASSERT(inp != NULL, ("div_detach: inp == NULL")); 456 INP_INFO_WLOCK(&divcbinfo); 457 INP_LOCK(inp); 458 in_pcbdetach(inp); 459 in_pcbfree(inp); 460 INP_INFO_WUNLOCK(&divcbinfo); 461 } 462 463 static int 464 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 465 { 466 struct inpcb *inp; 467 int error; 468 469 inp = sotoinpcb(so); 470 KASSERT(inp != NULL, ("div_bind: inp == NULL")); 471 /* in_pcbbind assumes that nam is a sockaddr_in 472 * and in_pcbbind requires a valid address. Since divert 473 * sockets don't we need to make sure the address is 474 * filled in properly. 475 * XXX -- divert should not be abusing in_pcbind 476 * and should probably have its own family. 477 */ 478 if (nam->sa_family != AF_INET) 479 return EAFNOSUPPORT; 480 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 481 INP_INFO_WLOCK(&divcbinfo); 482 INP_LOCK(inp); 483 error = in_pcbbind(inp, nam, td->td_ucred); 484 INP_UNLOCK(inp); 485 INP_INFO_WUNLOCK(&divcbinfo); 486 return error; 487 } 488 489 static int 490 div_shutdown(struct socket *so) 491 { 492 struct inpcb *inp; 493 494 inp = sotoinpcb(so); 495 KASSERT(inp != NULL, ("div_shutdown: inp == NULL")); 496 INP_LOCK(inp); 497 socantsendmore(so); 498 INP_UNLOCK(inp); 499 return 0; 500 } 501 502 static int 503 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 504 struct mbuf *control, struct thread *td) 505 { 506 /* Packet must have a header (but that's about it) */ 507 if (m->m_len < sizeof (struct ip) && 508 (m = m_pullup(m, sizeof (struct ip))) == 0) { 509 ipstat.ips_toosmall++; 510 m_freem(m); 511 return EINVAL; 512 } 513 514 /* Send packet */ 515 return div_output(so, m, (struct sockaddr_in *)nam, control); 516 } 517 518 void 519 div_ctlinput(int cmd, struct sockaddr *sa, void *vip) 520 { 521 struct in_addr faddr; 522 523 faddr = ((struct sockaddr_in *)sa)->sin_addr; 524 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 525 return; 526 if (PRC_IS_REDIRECT(cmd)) 527 return; 528 } 529 530 static int 531 div_pcblist(SYSCTL_HANDLER_ARGS) 532 { 533 int error, i, n; 534 struct inpcb *inp, **inp_list; 535 inp_gen_t gencnt; 536 struct xinpgen xig; 537 538 /* 539 * The process of preparing the TCB list is too time-consuming and 540 * resource-intensive to repeat twice on every request. 541 */ 542 if (req->oldptr == 0) { 543 n = divcbinfo.ipi_count; 544 req->oldidx = 2 * (sizeof xig) 545 + (n + n/8) * sizeof(struct xinpcb); 546 return 0; 547 } 548 549 if (req->newptr != 0) 550 return EPERM; 551 552 /* 553 * OK, now we're committed to doing something. 554 */ 555 INP_INFO_RLOCK(&divcbinfo); 556 gencnt = divcbinfo.ipi_gencnt; 557 n = divcbinfo.ipi_count; 558 INP_INFO_RUNLOCK(&divcbinfo); 559 560 error = sysctl_wire_old_buffer(req, 561 2 * sizeof(xig) + n*sizeof(struct xinpcb)); 562 if (error != 0) 563 return (error); 564 565 xig.xig_len = sizeof xig; 566 xig.xig_count = n; 567 xig.xig_gen = gencnt; 568 xig.xig_sogen = so_gencnt; 569 error = SYSCTL_OUT(req, &xig, sizeof xig); 570 if (error) 571 return error; 572 573 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 574 if (inp_list == 0) 575 return ENOMEM; 576 577 INP_INFO_RLOCK(&divcbinfo); 578 for (inp = LIST_FIRST(divcbinfo.listhead), i = 0; inp && i < n; 579 inp = LIST_NEXT(inp, inp_list)) { 580 INP_LOCK(inp); 581 if (inp->inp_gencnt <= gencnt && 582 cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0) 583 inp_list[i++] = inp; 584 INP_UNLOCK(inp); 585 } 586 INP_INFO_RUNLOCK(&divcbinfo); 587 n = i; 588 589 error = 0; 590 for (i = 0; i < n; i++) { 591 inp = inp_list[i]; 592 INP_LOCK(inp); 593 if (inp->inp_gencnt <= gencnt) { 594 struct xinpcb xi; 595 bzero(&xi, sizeof(xi)); 596 xi.xi_len = sizeof xi; 597 /* XXX should avoid extra copy */ 598 bcopy(inp, &xi.xi_inp, sizeof *inp); 599 if (inp->inp_socket) 600 sotoxsocket(inp->inp_socket, &xi.xi_socket); 601 INP_UNLOCK(inp); 602 error = SYSCTL_OUT(req, &xi, sizeof xi); 603 } else 604 INP_UNLOCK(inp); 605 } 606 if (!error) { 607 /* 608 * Give the user an updated idea of our state. 609 * If the generation differs from what we told 610 * her before, she knows that something happened 611 * while we were processing this request, and it 612 * might be necessary to retry. 613 */ 614 INP_INFO_RLOCK(&divcbinfo); 615 xig.xig_gen = divcbinfo.ipi_gencnt; 616 xig.xig_sogen = so_gencnt; 617 xig.xig_count = divcbinfo.ipi_count; 618 INP_INFO_RUNLOCK(&divcbinfo); 619 error = SYSCTL_OUT(req, &xig, sizeof xig); 620 } 621 free(inp_list, M_TEMP); 622 return error; 623 } 624 625 /* 626 * This is the wrapper function for in_setsockaddr. We just pass down 627 * the pcbinfo for in_setpeeraddr to lock. 628 */ 629 static int 630 div_sockaddr(struct socket *so, struct sockaddr **nam) 631 { 632 return (in_setsockaddr(so, nam, &divcbinfo)); 633 } 634 635 /* 636 * This is the wrapper function for in_setpeeraddr. We just pass down 637 * the pcbinfo for in_setpeeraddr to lock. 638 */ 639 static int 640 div_peeraddr(struct socket *so, struct sockaddr **nam) 641 { 642 return (in_setpeeraddr(so, nam, &divcbinfo)); 643 } 644 645 #ifdef SYSCTL_NODE 646 SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, "IPDIVERT"); 647 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLFLAG_RD, 0, 0, 648 div_pcblist, "S,xinpcb", "List of active divert sockets"); 649 #endif 650 651 struct pr_usrreqs div_usrreqs = { 652 .pru_attach = div_attach, 653 .pru_bind = div_bind, 654 .pru_control = in_control, 655 .pru_detach = div_detach, 656 .pru_peeraddr = div_peeraddr, 657 .pru_send = div_send, 658 .pru_shutdown = div_shutdown, 659 .pru_sockaddr = div_sockaddr, 660 .pru_sosetlabel = in_pcbsosetlabel 661 }; 662 663 struct protosw div_protosw = { 664 .pr_type = SOCK_RAW, 665 .pr_protocol = IPPROTO_DIVERT, 666 .pr_flags = PR_ATOMIC|PR_ADDR, 667 .pr_input = div_input, 668 .pr_ctlinput = div_ctlinput, 669 .pr_ctloutput = ip_ctloutput, 670 .pr_init = div_init, 671 .pr_usrreqs = &div_usrreqs 672 }; 673 674 static int 675 div_modevent(module_t mod, int type, void *unused) 676 { 677 int err = 0; 678 int n; 679 680 switch (type) { 681 case MOD_LOAD: 682 /* 683 * Protocol will be initialized by pf_proto_register(). 684 * We don't have to register ip_protox because we are not 685 * a true IP protocol that goes over the wire. 686 */ 687 err = pf_proto_register(PF_INET, &div_protosw); 688 ip_divert_ptr = divert_packet; 689 break; 690 case MOD_QUIESCE: 691 /* 692 * IPDIVERT may normally not be unloaded because of the 693 * potential race conditions. Tell kldunload we can't be 694 * unloaded unless the unload is forced. 695 */ 696 err = EPERM; 697 break; 698 case MOD_UNLOAD: 699 /* 700 * Forced unload. 701 * 702 * Module ipdivert can only be unloaded if no sockets are 703 * connected. Maybe this can be changed later to forcefully 704 * disconnect any open sockets. 705 * 706 * XXXRW: Note that there is a slight race here, as a new 707 * socket open request could be spinning on the lock and then 708 * we destroy the lock. 709 */ 710 INP_INFO_WLOCK(&divcbinfo); 711 n = divcbinfo.ipi_count; 712 if (n != 0) { 713 err = EBUSY; 714 INP_INFO_WUNLOCK(&divcbinfo); 715 break; 716 } 717 ip_divert_ptr = NULL; 718 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW); 719 INP_INFO_WUNLOCK(&divcbinfo); 720 INP_INFO_LOCK_DESTROY(&divcbinfo); 721 uma_zdestroy(divcbinfo.ipi_zone); 722 break; 723 default: 724 err = EOPNOTSUPP; 725 break; 726 } 727 return err; 728 } 729 730 static moduledata_t ipdivertmod = { 731 "ipdivert", 732 div_modevent, 733 0 734 }; 735 736 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 737 MODULE_DEPEND(dummynet, ipfw, 2, 2, 2); 738 MODULE_VERSION(ipdivert, 1); 739