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 "opt_inet.h" 33 #include "opt_inet6.h" 34 #include "opt_sctp.h" 35 36 #include <sys/param.h> 37 #include <sys/ck.h> 38 #include <sys/eventhandler.h> 39 #include <sys/hash.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/mbuf.h> 44 #include <sys/module.h> 45 #include <sys/kernel.h> 46 #include <sys/priv.h> 47 #include <sys/proc.h> 48 #include <sys/domain.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/sysctl.h> 53 54 #include <machine/atomic.h> 55 56 #include <net/if.h> 57 #include <net/if_var.h> 58 #include <net/if_private.h> 59 #include <net/netisr.h> 60 #include <net/vnet.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 #include <netinet/ip_divert.h> 69 #ifdef INET6 70 #include <netinet/ip6.h> 71 #include <netinet6/ip6_var.h> 72 #endif 73 #if defined(SCTP) || defined(SCTP_SUPPORT) 74 #include <netinet/sctp_crc32.h> 75 #endif 76 77 #include <security/mac/mac_framework.h> 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 * Usually a system has very few divert ports. Previous implementation 90 * used a linked list. 91 */ 92 #define DIVHASHSIZE (1 << 3) /* 8 entries, one cache line. */ 93 #define DIVHASH(port) (port % DIVHASHSIZE) 94 #define DCBHASH(dcb) (DIVHASH((dcb)->dcb_port)) 95 96 /* 97 * Divert sockets work in conjunction with ipfw or other packet filters, 98 * see the divert(4) manpage for features. 99 * Packets are selected by the packet filter and tagged with an 100 * MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by 101 * the packet filter) and information on the matching filter rule for 102 * subsequent reinjection. The divert_port is used to put the packet 103 * on the corresponding divert socket, while the rule number is passed 104 * up (at least partially) as the sin_port in the struct sockaddr. 105 * 106 * Packets written to the divert socket carry in sin_addr a 107 * destination address, and in sin_port the number of the filter rule 108 * after which to continue processing. 109 * If the destination address is INADDR_ANY, the packet is treated as 110 * as outgoing and sent to ip_output(); otherwise it is treated as 111 * incoming and sent to ip_input(). 112 * Further, sin_zero carries some information on the interface, 113 * which can be used in the reinject -- see comments in the code. 114 * 115 * On reinjection, processing in ip_input() and ip_output() 116 * will be exactly the same as for the original packet, except that 117 * packet filter processing will start at the rule number after the one 118 * written in the sin_port (ipfw does not allow a rule #0, so sin_port=0 119 * will apply the entire ruleset to the packet). 120 */ 121 static SYSCTL_NODE(_net_inet, OID_AUTO, divert, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 122 "divert(4)"); 123 124 VNET_PCPUSTAT_DEFINE_STATIC(struct divstat, divstat); 125 VNET_PCPUSTAT_SYSINIT(divstat); 126 #ifdef VIMAGE 127 VNET_PCPUSTAT_SYSUNINIT(divstat); 128 #endif 129 SYSCTL_VNET_PCPUSTAT(_net_inet_divert, OID_AUTO, stats, struct divstat, 130 divstat, "divert(4) socket statistics"); 131 #define DIVSTAT_INC(name) \ 132 VNET_PCPUSTAT_ADD(struct divstat, divstat, div_ ## name, 1) 133 134 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 135 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 136 137 static int div_output_inbound(int fmaily, struct socket *so, struct mbuf *m, 138 struct sockaddr_in *sin); 139 static int div_output_outbound(int family, struct socket *so, struct mbuf *m); 140 141 struct divcb { 142 union { 143 CK_SLIST_ENTRY(divcb) dcb_next; 144 intptr_t dcb_bound; 145 #define DCB_UNBOUND ((intptr_t)-1) 146 }; 147 struct socket *dcb_socket; 148 uint16_t dcb_port; 149 uint64_t dcb_gencnt; 150 struct epoch_context dcb_epochctx; 151 }; 152 153 struct divcblbgroup { 154 CK_SLIST_ENTRY(divcblbgroup) dl_next; 155 struct epoch_context dl_epochctx; 156 uint16_t dl_port; 157 int dl_count; 158 #define DIVCBLBGROUP_SIZE 32 159 struct divcb *dl_dcb[DIVCBLBGROUP_SIZE]; 160 }; 161 162 CK_SLIST_HEAD(divhashhead, divcb); 163 CK_SLIST_HEAD(divlbgrouphashhead, divcblbgroup); 164 165 VNET_DEFINE_STATIC(struct divhashhead, divhash[DIVHASHSIZE]); 166 #define V_divhash VNET(divhash) 167 VNET_DEFINE_STATIC(struct divlbgrouphashhead, divlbhash[DIVHASHSIZE]); 168 #define V_divlbhash VNET(divlbhash) 169 VNET_DEFINE_STATIC(uint64_t, dcb_count) = 0; 170 #define V_dcb_count VNET(dcb_count) 171 VNET_DEFINE_STATIC(uint64_t, dcb_gencnt) = 0; 172 #define V_dcb_gencnt VNET(dcb_gencnt) 173 174 static struct mtx divert_mtx; 175 MTX_SYSINIT(divert, &divert_mtx, "divert(4) socket pcb lists", MTX_DEF); 176 #define DIVERT_LOCK() mtx_lock(&divert_mtx) 177 #define DIVERT_UNLOCK() mtx_unlock(&divert_mtx) 178 179 /* 180 * Divert a packet by passing it up to the divert socket at port 'port'. 181 * 182 * 'id' is an opaque identifier for the flow and is used to load-balance packets 183 * across multiple divert sockets bound to the same port. Packets with the same 184 * identifier will be delivered to the same socket. 185 */ 186 static void 187 divert_packet(struct mbuf *m, uint64_t id, bool incoming) 188 { 189 struct divcblbgroup *dlb; 190 struct divcb *dcb; 191 u_int16_t nport; 192 struct sockaddr_in divsrc; 193 struct m_tag *mtag; 194 uint16_t cookie; 195 196 NET_EPOCH_ASSERT(); 197 198 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 199 if (mtag != NULL) { 200 cookie = ((struct ipfw_rule_ref *)(mtag+1))->rulenum; 201 nport = htons((uint16_t) 202 (((struct ipfw_rule_ref *)(mtag+1))->info)); 203 } else if ((mtag = m_tag_locate(m, MTAG_PF_DIVERT, 0, NULL)) != NULL) { 204 cookie = ((struct pf_divert_mtag *)(mtag+1))->idir; 205 nport = htons(((struct pf_divert_mtag *)(mtag+1))->port); 206 } else { 207 m_freem(m); 208 return; 209 } 210 /* Assure header */ 211 if (m->m_len < sizeof(struct ip) && 212 (m = m_pullup(m, sizeof(struct ip))) == NULL) 213 return; 214 #ifdef INET 215 /* Delayed checksums are currently not compatible with divert. */ 216 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 217 in_delayed_cksum(m); 218 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 219 } 220 #if defined(SCTP) || defined(SCTP_SUPPORT) 221 if (m->m_pkthdr.csum_flags & CSUM_SCTP) { 222 struct ip *ip; 223 224 ip = mtod(m, struct ip *); 225 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 226 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 227 } 228 #endif 229 #endif 230 #ifdef INET6 231 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 232 in6_delayed_cksum(m, m->m_pkthdr.len - 233 sizeof(struct ip6_hdr), sizeof(struct ip6_hdr)); 234 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; 235 } 236 #if defined(SCTP) || defined(SCTP_SUPPORT) 237 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { 238 sctp_delayed_cksum(m, sizeof(struct ip6_hdr)); 239 m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; 240 } 241 #endif 242 #endif /* INET6 */ 243 bzero(&divsrc, sizeof(divsrc)); 244 divsrc.sin_len = sizeof(divsrc); 245 divsrc.sin_family = AF_INET; 246 /* record matching rule, in host format */ 247 divsrc.sin_port = cookie; 248 /* 249 * Record receive interface address, if any. 250 * But only for incoming packets. 251 */ 252 if (incoming) { 253 struct ifaddr *ifa; 254 struct ifnet *ifp; 255 256 /* Sanity check */ 257 M_ASSERTPKTHDR(m); 258 259 /* Find IP address for receive interface */ 260 ifp = m->m_pkthdr.rcvif; 261 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 262 if (ifa->ifa_addr->sa_family != AF_INET) 263 continue; 264 divsrc.sin_addr = 265 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 266 break; 267 } 268 } 269 /* 270 * Record the incoming interface name whenever we have one. 271 */ 272 if (m->m_pkthdr.rcvif) { 273 /* 274 * Hide the actual interface name in there in the 275 * sin_zero array. XXX This needs to be moved to a 276 * different sockaddr type for divert, e.g. 277 * sockaddr_div with multiple fields like 278 * sockaddr_dl. Presently we have only 7 bytes 279 * but that will do for now as most interfaces 280 * are 4 or less + 2 or less bytes for unit. 281 * There is probably a faster way of doing this, 282 * possibly taking it from the sockaddr_dl on the iface. 283 * This solves the problem of a P2P link and a LAN interface 284 * having the same address, which can result in the wrong 285 * interface being assigned to the packet when fed back 286 * into the divert socket. Theoretically if the daemon saves 287 * and re-uses the sockaddr_in as suggested in the man pages, 288 * this iface name will come along for the ride. 289 * (see div_output for the other half of this.) 290 */ 291 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname, 292 sizeof(divsrc.sin_zero)); 293 } 294 295 /* 296 * Look for a matching divert socket or socket group, and enqueue the 297 * packet. 298 */ 299 CK_SLIST_FOREACH(dlb, &V_divlbhash[DIVHASH(nport)], dl_next) { 300 uint16_t count; 301 302 count = atomic_load_acq_int(&dlb->dl_count); 303 if (dlb->dl_port == nport && count > 0) { 304 uint32_t hash; 305 306 hash = jenkins_hash(&id, sizeof(uint64_t), 0); 307 dcb = dlb->dl_dcb[hash % count]; 308 break; 309 } 310 } 311 if (dlb == NULL) { 312 CK_SLIST_FOREACH(dcb, &V_divhash[DIVHASH(nport)], dcb_next) 313 if (dcb->dcb_port == nport) 314 break; 315 } 316 317 if (dcb != NULL) { 318 struct socket *sa = dcb->dcb_socket; 319 320 SOCKBUF_LOCK(&sa->so_rcv); 321 if (sbappendaddr_locked(&sa->so_rcv, 322 (struct sockaddr *)&divsrc, m, NULL) == 0) { 323 soroverflow_locked(sa); 324 m_freem(m); 325 } else { 326 sorwakeup_locked(sa); 327 DIVSTAT_INC(diverted); 328 } 329 } else { 330 DIVSTAT_INC(noport); 331 m_freem(m); 332 } 333 } 334 335 /* 336 * Deliver packet back into the IP processing machinery. 337 * 338 * If no address specified, or address is 0.0.0.0, send to ip_output(); 339 * otherwise, send to ip_input() and mark as having been received on 340 * the interface with that address. 341 */ 342 static int 343 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 344 struct mbuf *control, struct thread *td) 345 { 346 struct epoch_tracker et; 347 struct sockaddr_in *sin = (struct sockaddr_in *)nam; 348 const struct ip *ip; 349 struct m_tag *mtag; 350 struct ipfw_rule_ref *dt; 351 struct pf_divert_mtag *pfdt; 352 int error, family; 353 354 if (control) 355 m_freem(control); 356 357 /* Packet must have a header (but that's about it) */ 358 if (m->m_len < sizeof (struct ip) && 359 (m = m_pullup(m, sizeof (struct ip))) == NULL) { 360 m_freem(m); 361 return (EINVAL); 362 } 363 364 if (sin != NULL) { 365 if (sin->sin_family != AF_INET) { 366 m_freem(m); 367 return (EAFNOSUPPORT); 368 } 369 if (sin->sin_len != sizeof(*sin)) { 370 m_freem(m); 371 return (EINVAL); 372 } 373 } 374 375 /* 376 * An mbuf may hasn't come from userland, but we pretend 377 * that it has. 378 */ 379 m->m_pkthdr.rcvif = NULL; 380 m->m_nextpkt = NULL; 381 M_SETFIB(m, so->so_fibnum); 382 383 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL); 384 if (mtag == NULL) { 385 /* this should be normal */ 386 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0, 387 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO); 388 if (mtag == NULL) { 389 m_freem(m); 390 return (ENOBUFS); 391 } 392 m_tag_prepend(m, mtag); 393 } 394 dt = (struct ipfw_rule_ref *)(mtag+1); 395 396 /* Loopback avoidance and state recovery */ 397 if (sin) { 398 int i; 399 400 /* set the starting point. We provide a non-zero slot, 401 * but a non_matching chain_id to skip that info and use 402 * the rulenum/rule_id. 403 */ 404 dt->slot = 1; /* dummy, chain_id is invalid */ 405 dt->chain_id = 0; 406 dt->rulenum = sin->sin_port+1; /* host format ? */ 407 dt->rule_id = 0; 408 /* XXX: broken for IPv6 */ 409 /* 410 * Find receive interface with the given name, stuffed 411 * (if it exists) in the sin_zero[] field. 412 * The name is user supplied data so don't trust its size 413 * or that it is zero terminated. 414 */ 415 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++) 416 ; 417 if ( i > 0 && i < sizeof(sin->sin_zero)) 418 m->m_pkthdr.rcvif = ifunit(sin->sin_zero); 419 } 420 421 ip = mtod(m, struct ip *); 422 switch (ip->ip_v) { 423 #ifdef INET 424 case IPVERSION: 425 family = AF_INET; 426 break; 427 #endif 428 #ifdef INET6 429 case IPV6_VERSION >> 4: 430 family = AF_INET6; 431 break; 432 #endif 433 default: 434 m_freem(m); 435 return (EAFNOSUPPORT); 436 } 437 438 mtag = m_tag_locate(m, MTAG_PF_DIVERT, 0, NULL); 439 if (mtag == NULL) { 440 /* this should be normal */ 441 mtag = m_tag_alloc(MTAG_PF_DIVERT, 0, 442 sizeof(struct pf_divert_mtag), M_NOWAIT | M_ZERO); 443 if (mtag == NULL) { 444 m_freem(m); 445 return (ENOBUFS); 446 } 447 m_tag_prepend(m, mtag); 448 } 449 pfdt = (struct pf_divert_mtag *)(mtag+1); 450 if (sin) 451 pfdt->idir = sin->sin_port; 452 453 /* Reinject packet into the system as incoming or outgoing */ 454 NET_EPOCH_ENTER(et); 455 if (!sin || sin->sin_addr.s_addr == 0) { 456 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT; 457 pfdt->ndir = PF_DIVERT_MTAG_DIR_OUT; 458 error = div_output_outbound(family, so, m); 459 } else { 460 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN; 461 pfdt->ndir = PF_DIVERT_MTAG_DIR_IN; 462 error = div_output_inbound(family, so, m, sin); 463 } 464 NET_EPOCH_EXIT(et); 465 466 return (error); 467 } 468 469 /* 470 * Sends mbuf @m to the wire via ip[6]_output(). 471 * 472 * Returns 0 on success or an errno value on failure. @m is always consumed. 473 */ 474 static int 475 div_output_outbound(int family, struct socket *so, struct mbuf *m) 476 { 477 int error; 478 479 switch (family) { 480 #ifdef INET 481 case AF_INET: 482 { 483 struct ip *const ip = mtod(m, struct ip *); 484 485 /* Don't allow packet length sizes that will crash. */ 486 if (((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { 487 m_freem(m); 488 return (EINVAL); 489 } 490 break; 491 } 492 #endif 493 #ifdef INET6 494 case AF_INET6: 495 { 496 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *); 497 498 /* Don't allow packet length sizes that will crash */ 499 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) { 500 m_freem(m); 501 return (EINVAL); 502 } 503 break; 504 } 505 #endif 506 } 507 508 #ifdef MAC 509 mac_socket_create_mbuf(so, m); 510 #endif 511 512 error = 0; 513 switch (family) { 514 #ifdef INET 515 case AF_INET: 516 error = ip_output(m, NULL, NULL, 517 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) 518 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL); 519 break; 520 #endif 521 #ifdef INET6 522 case AF_INET6: 523 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 524 break; 525 #endif 526 } 527 if (error == 0) 528 DIVSTAT_INC(outbound); 529 530 return (error); 531 } 532 533 /* 534 * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue. 535 * 536 * Returns 0 on success or an errno value on failure. @m is always consumed. 537 */ 538 static int 539 div_output_inbound(int family, struct socket *so, struct mbuf *m, 540 struct sockaddr_in *sin) 541 { 542 #if defined(INET) || defined(INET6) 543 struct divcb *dcb = so->so_pcb; 544 #endif 545 struct ifaddr *ifa; 546 547 if (m->m_pkthdr.rcvif == NULL) { 548 /* 549 * No luck with the name, check by IP address. 550 * Clear the port and the ifname to make sure 551 * there are no distractions for ifa_ifwithaddr. 552 */ 553 554 /* XXX: broken for IPv6 */ 555 bzero(sin->sin_zero, sizeof(sin->sin_zero)); 556 sin->sin_port = 0; 557 ifa = ifa_ifwithaddr((struct sockaddr *) sin); 558 if (ifa == NULL) { 559 m_freem(m); 560 return (EADDRNOTAVAIL); 561 } 562 m->m_pkthdr.rcvif = ifa->ifa_ifp; 563 } 564 #ifdef MAC 565 mac_socket_create_mbuf(so, m); 566 #endif 567 /* Send packet to input processing via netisr */ 568 switch (family) { 569 #ifdef INET 570 case AF_INET: 571 { 572 const struct ip *ip; 573 574 ip = mtod(m, struct ip *); 575 /* 576 * Restore M_BCAST flag when destination address is 577 * broadcast. It is expected by ip_tryforward(). 578 */ 579 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) 580 m->m_flags |= M_MCAST; 581 else if (in_ifnet_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) 582 m->m_flags |= M_BCAST; 583 netisr_queue_src(NETISR_IP, (uintptr_t)dcb->dcb_gencnt, m); 584 DIVSTAT_INC(inbound); 585 break; 586 } 587 #endif 588 #ifdef INET6 589 case AF_INET6: 590 netisr_queue_src(NETISR_IPV6, (uintptr_t)dcb->dcb_gencnt, m); 591 DIVSTAT_INC(inbound); 592 break; 593 #endif 594 default: 595 m_freem(m); 596 return (EINVAL); 597 } 598 599 return (0); 600 } 601 602 static int 603 div_attach(struct socket *so, int proto, struct thread *td) 604 { 605 struct divcb *dcb; 606 int error; 607 608 if (td != NULL) { 609 error = priv_check(td, PRIV_NETINET_DIVERT); 610 if (error) 611 return (error); 612 } 613 error = soreserve(so, div_sendspace, div_recvspace); 614 if (error) 615 return error; 616 dcb = malloc(sizeof(*dcb), M_PCB, M_WAITOK); 617 dcb->dcb_bound = DCB_UNBOUND; 618 dcb->dcb_socket = so; 619 DIVERT_LOCK(); 620 V_dcb_count++; 621 dcb->dcb_gencnt = ++V_dcb_gencnt; 622 DIVERT_UNLOCK(); 623 so->so_pcb = dcb; 624 625 return (0); 626 } 627 628 static void 629 div_free(epoch_context_t ctx) 630 { 631 struct divcb *dcb = __containerof(ctx, struct divcb, dcb_epochctx); 632 633 free(dcb, M_PCB); 634 } 635 636 static void 637 divlbgroup_free(epoch_context_t ctx) 638 { 639 struct divcblbgroup *dlb = __containerof(ctx, struct divcblbgroup, 640 dl_epochctx); 641 642 free(dlb, M_PCB); 643 } 644 645 static void 646 div_lbgroup_detach(struct divcb *dcb) 647 { 648 struct divcblbgroup *dlb; 649 650 CK_SLIST_FOREACH(dlb, &V_divlbhash[DCBHASH(dcb)], dl_next) { 651 if (dlb->dl_port != dcb->dcb_port) 652 continue; 653 654 /* 655 * Delicately remove the socket from its group, taking 656 * care to synchronize with lookups, which do not handle 657 * NULL slots in the group table. 658 * 659 * Note that the hash is not stable across different 660 * group sizes. 661 */ 662 for (int i = 0; i < dlb->dl_count; i++) { 663 unsigned int count; 664 665 if (dlb->dl_dcb[i] != dcb) 666 continue; 667 668 count = dlb->dl_count; 669 if (i != count - 1) 670 dlb->dl_dcb[i] = dlb->dl_dcb[count - 1]; 671 atomic_store_rel_int(&dlb->dl_count, count - 1); 672 if (count == 1) { 673 CK_SLIST_REMOVE(&V_divlbhash[DCBHASH(dcb)], dlb, 674 divcblbgroup, dl_next); 675 NET_EPOCH_CALL(divlbgroup_free, 676 &dlb->dl_epochctx); 677 } 678 return; 679 } 680 } 681 } 682 683 static void 684 div_detach(struct socket *so) 685 { 686 struct divcb *dcb = so->so_pcb; 687 688 so->so_pcb = NULL; 689 DIVERT_LOCK(); 690 if (dcb->dcb_bound != DCB_UNBOUND) { 691 CK_SLIST_REMOVE(&V_divhash[DCBHASH(dcb)], dcb, divcb, dcb_next); 692 div_lbgroup_detach(dcb); 693 } 694 V_dcb_count--; 695 V_dcb_gencnt++; 696 DIVERT_UNLOCK(); 697 NET_EPOCH_CALL(div_free, &dcb->dcb_epochctx); 698 } 699 700 static int 701 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 702 { 703 struct divcblbgroup *dlb; 704 struct divcb *dcb; 705 int error; 706 uint16_t port; 707 708 if (nam->sa_family != AF_INET) 709 return EAFNOSUPPORT; 710 if (nam->sa_len != sizeof(struct sockaddr_in)) 711 return EINVAL; 712 713 error = 0; 714 if ((so->so_options & SO_REUSEPORT_LB) != 0) 715 dlb = malloc(sizeof(*dlb), M_PCB, M_WAITOK | M_ZERO); 716 else 717 dlb = NULL; 718 719 port = ((struct sockaddr_in *)nam)->sin_port; 720 DIVERT_LOCK(); 721 if (dlb == NULL) { 722 CK_SLIST_FOREACH(dcb, &V_divhash[DIVHASH(port)], dcb_next) { 723 if (dcb->dcb_port == port) { 724 DIVERT_UNLOCK(); 725 return (EADDRINUSE); 726 } 727 } 728 } 729 dcb = so->so_pcb; 730 if (dlb != NULL) { 731 struct divcblbgroup *tmp; 732 733 CK_SLIST_FOREACH(tmp, &V_divlbhash[DIVHASH(port)], dl_next) { 734 if (tmp->dl_port == port) 735 break; 736 } 737 if (tmp == NULL) { 738 dlb->dl_port = port; 739 dlb->dl_count = 1; 740 dlb->dl_dcb[0] = dcb; 741 CK_SLIST_INSERT_HEAD(&V_divlbhash[DIVHASH(port)], dlb, 742 dl_next); 743 } else if (tmp->dl_count < DIVCBLBGROUP_SIZE) { 744 KASSERT(tmp->dl_count > 0, 745 ("div_bind: lbgroup %p has count 0", tmp)); 746 747 tmp->dl_dcb[tmp->dl_count] = dcb; 748 atomic_store_rel_int(&tmp->dl_count, tmp->dl_count + 1); 749 free(dlb, M_PCB); 750 } else { 751 error = ENOSPC; 752 free(dlb, M_PCB); 753 } 754 } 755 if (error == 0) { 756 if (dcb->dcb_bound != DCB_UNBOUND) { 757 CK_SLIST_REMOVE(&V_divhash[DCBHASH(dcb)], dcb, divcb, 758 dcb_next); 759 div_lbgroup_detach(dcb); 760 } 761 dcb->dcb_port = port; 762 CK_SLIST_INSERT_HEAD(&V_divhash[DIVHASH(port)], dcb, dcb_next); 763 } 764 DIVERT_UNLOCK(); 765 766 return (error); 767 } 768 769 static int 770 div_pcblist(SYSCTL_HANDLER_ARGS) 771 { 772 struct xinpgen xig; 773 struct divcb *dcb; 774 int error; 775 776 if (req->newptr != 0) 777 return EPERM; 778 779 if (req->oldptr == 0) { 780 u_int n; 781 782 n = V_dcb_count; 783 n += imax(n / 8, 10); 784 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb); 785 return 0; 786 } 787 788 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 789 return (error); 790 791 bzero(&xig, sizeof(xig)); 792 xig.xig_len = sizeof xig; 793 xig.xig_count = V_dcb_count; 794 xig.xig_gen = V_dcb_gencnt; 795 xig.xig_sogen = so_gencnt; 796 error = SYSCTL_OUT(req, &xig, sizeof xig); 797 if (error) 798 return error; 799 800 DIVERT_LOCK(); 801 for (int i = 0; i < DIVHASHSIZE; i++) 802 CK_SLIST_FOREACH(dcb, &V_divhash[i], dcb_next) { 803 if (dcb->dcb_gencnt <= xig.xig_gen) { 804 struct xinpcb xi; 805 806 bzero(&xi, sizeof(xi)); 807 xi.xi_len = sizeof(struct xinpcb); 808 sotoxsocket(dcb->dcb_socket, &xi.xi_socket); 809 xi.inp_gencnt = dcb->dcb_gencnt; 810 xi.inp_vflag = INP_IPV4; /* XXX: netstat(1) */ 811 xi.inp_inc.inc_ie.ie_lport = dcb->dcb_port; 812 error = SYSCTL_OUT(req, &xi, sizeof xi); 813 if (error) 814 goto errout; 815 } 816 } 817 818 /* 819 * Give the user an updated idea of our state. 820 * If the generation differs from what we told 821 * her before, she knows that something happened 822 * while we were processing this request, and it 823 * might be necessary to retry. 824 */ 825 xig.xig_gen = V_dcb_gencnt; 826 xig.xig_sogen = so_gencnt; 827 xig.xig_count = V_dcb_count; 828 error = SYSCTL_OUT(req, &xig, sizeof xig); 829 830 errout: 831 DIVERT_UNLOCK(); 832 833 return (error); 834 } 835 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, 836 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, div_pcblist, 837 "S,xinpcb", "List of active divert sockets"); 838 839 static struct protosw div_protosw = { 840 .pr_type = SOCK_RAW, 841 .pr_flags = PR_ATOMIC|PR_ADDR, 842 .pr_attach = div_attach, 843 .pr_bind = div_bind, 844 .pr_detach = div_detach, 845 .pr_send = div_send, 846 }; 847 848 static struct domain divertdomain = { 849 .dom_family = PF_DIVERT, 850 .dom_name = "divert", 851 .dom_nprotosw = 1, 852 .dom_protosw = { &div_protosw }, 853 }; 854 855 static int 856 div_modevent(module_t mod, int type, void *unused) 857 { 858 int err = 0; 859 860 switch (type) { 861 case MOD_LOAD: 862 domain_add(&divertdomain); 863 ip_divert_ptr = divert_packet; 864 break; 865 case MOD_QUIESCE: 866 /* 867 * IPDIVERT may normally not be unloaded because of the 868 * potential race conditions. Tell kldunload we can't be 869 * unloaded unless the unload is forced. 870 */ 871 err = EPERM; 872 break; 873 case MOD_UNLOAD: 874 /* 875 * Forced unload. 876 * 877 * Module ipdivert can only be unloaded if no sockets are 878 * connected. Maybe this can be changed later to forcefully 879 * disconnect any open sockets. 880 * 881 * XXXRW: Note that there is a slight race here, as a new 882 * socket open request could be spinning on the lock and then 883 * we destroy the lock. 884 * 885 * XXXGL: One more reason this code is incorrect is that it 886 * checks only the current vnet. 887 */ 888 DIVERT_LOCK(); 889 if (V_dcb_count != 0) { 890 DIVERT_UNLOCK(); 891 err = EBUSY; 892 break; 893 } 894 DIVERT_UNLOCK(); 895 ip_divert_ptr = NULL; 896 domain_remove(&divertdomain); 897 break; 898 default: 899 err = EOPNOTSUPP; 900 break; 901 } 902 return err; 903 } 904 905 static moduledata_t ipdivertmod = { 906 "ipdivert", 907 div_modevent, 908 0 909 }; 910 911 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 912 MODULE_VERSION(ipdivert, 1); 913