1 /* 2 * IPVS An implementation of the IP virtual server support for the 3 * LINUX operating system. IPVS is now implemented as a module 4 * over the Netfilter framework. IPVS can be used to build a 5 * high-performance and highly available server based on a 6 * cluster of servers. 7 * 8 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> 9 * Peter Kese <peter.kese@ijs.si> 10 * Julian Anastasov <ja@ssi.bg> 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 * 17 * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese, 18 * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms 19 * and others. 20 * 21 * Changes: 22 * Paul `Rusty' Russell properly handle non-linear skbs 23 * Harald Welte don't use nfcache 24 * 25 */ 26 27 #define KMSG_COMPONENT "IPVS" 28 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 29 30 #include <linux/module.h> 31 #include <linux/kernel.h> 32 #include <linux/ip.h> 33 #include <linux/tcp.h> 34 #include <linux/sctp.h> 35 #include <linux/icmp.h> 36 #include <linux/slab.h> 37 38 #include <net/ip.h> 39 #include <net/tcp.h> 40 #include <net/udp.h> 41 #include <net/icmp.h> /* for icmp_send */ 42 #include <net/route.h> 43 #include <net/ip6_checksum.h> 44 #include <net/netns/generic.h> /* net_generic() */ 45 46 #include <linux/netfilter.h> 47 #include <linux/netfilter_ipv4.h> 48 49 #ifdef CONFIG_IP_VS_IPV6 50 #include <net/ipv6.h> 51 #include <linux/netfilter_ipv6.h> 52 #include <net/ip6_route.h> 53 #endif 54 55 #include <net/ip_vs.h> 56 57 58 EXPORT_SYMBOL(register_ip_vs_scheduler); 59 EXPORT_SYMBOL(unregister_ip_vs_scheduler); 60 EXPORT_SYMBOL(ip_vs_proto_name); 61 EXPORT_SYMBOL(ip_vs_conn_new); 62 EXPORT_SYMBOL(ip_vs_conn_in_get); 63 EXPORT_SYMBOL(ip_vs_conn_out_get); 64 #ifdef CONFIG_IP_VS_PROTO_TCP 65 EXPORT_SYMBOL(ip_vs_tcp_conn_listen); 66 #endif 67 EXPORT_SYMBOL(ip_vs_conn_put); 68 #ifdef CONFIG_IP_VS_DEBUG 69 EXPORT_SYMBOL(ip_vs_get_debug_level); 70 #endif 71 72 static int ip_vs_net_id __read_mostly; 73 /* netns cnt used for uniqueness */ 74 static atomic_t ipvs_netns_cnt = ATOMIC_INIT(0); 75 76 /* ID used in ICMP lookups */ 77 #define icmp_id(icmph) (((icmph)->un).echo.id) 78 #define icmpv6_id(icmph) (icmph->icmp6_dataun.u_echo.identifier) 79 80 const char *ip_vs_proto_name(unsigned int proto) 81 { 82 static char buf[20]; 83 84 switch (proto) { 85 case IPPROTO_IP: 86 return "IP"; 87 case IPPROTO_UDP: 88 return "UDP"; 89 case IPPROTO_TCP: 90 return "TCP"; 91 case IPPROTO_SCTP: 92 return "SCTP"; 93 case IPPROTO_ICMP: 94 return "ICMP"; 95 #ifdef CONFIG_IP_VS_IPV6 96 case IPPROTO_ICMPV6: 97 return "ICMPv6"; 98 #endif 99 default: 100 sprintf(buf, "IP_%u", proto); 101 return buf; 102 } 103 } 104 105 void ip_vs_init_hash_table(struct list_head *table, int rows) 106 { 107 while (--rows >= 0) 108 INIT_LIST_HEAD(&table[rows]); 109 } 110 111 static inline void 112 ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb) 113 { 114 struct ip_vs_dest *dest = cp->dest; 115 struct netns_ipvs *ipvs = cp->ipvs; 116 117 if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { 118 struct ip_vs_cpu_stats *s; 119 struct ip_vs_service *svc; 120 121 s = this_cpu_ptr(dest->stats.cpustats); 122 u64_stats_update_begin(&s->syncp); 123 s->cnt.inpkts++; 124 s->cnt.inbytes += skb->len; 125 u64_stats_update_end(&s->syncp); 126 127 rcu_read_lock(); 128 svc = rcu_dereference(dest->svc); 129 s = this_cpu_ptr(svc->stats.cpustats); 130 u64_stats_update_begin(&s->syncp); 131 s->cnt.inpkts++; 132 s->cnt.inbytes += skb->len; 133 u64_stats_update_end(&s->syncp); 134 rcu_read_unlock(); 135 136 s = this_cpu_ptr(ipvs->tot_stats.cpustats); 137 u64_stats_update_begin(&s->syncp); 138 s->cnt.inpkts++; 139 s->cnt.inbytes += skb->len; 140 u64_stats_update_end(&s->syncp); 141 } 142 } 143 144 145 static inline void 146 ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb) 147 { 148 struct ip_vs_dest *dest = cp->dest; 149 struct netns_ipvs *ipvs = cp->ipvs; 150 151 if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { 152 struct ip_vs_cpu_stats *s; 153 struct ip_vs_service *svc; 154 155 s = this_cpu_ptr(dest->stats.cpustats); 156 u64_stats_update_begin(&s->syncp); 157 s->cnt.outpkts++; 158 s->cnt.outbytes += skb->len; 159 u64_stats_update_end(&s->syncp); 160 161 rcu_read_lock(); 162 svc = rcu_dereference(dest->svc); 163 s = this_cpu_ptr(svc->stats.cpustats); 164 u64_stats_update_begin(&s->syncp); 165 s->cnt.outpkts++; 166 s->cnt.outbytes += skb->len; 167 u64_stats_update_end(&s->syncp); 168 rcu_read_unlock(); 169 170 s = this_cpu_ptr(ipvs->tot_stats.cpustats); 171 u64_stats_update_begin(&s->syncp); 172 s->cnt.outpkts++; 173 s->cnt.outbytes += skb->len; 174 u64_stats_update_end(&s->syncp); 175 } 176 } 177 178 179 static inline void 180 ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc) 181 { 182 struct netns_ipvs *ipvs = svc->ipvs; 183 struct ip_vs_cpu_stats *s; 184 185 s = this_cpu_ptr(cp->dest->stats.cpustats); 186 u64_stats_update_begin(&s->syncp); 187 s->cnt.conns++; 188 u64_stats_update_end(&s->syncp); 189 190 s = this_cpu_ptr(svc->stats.cpustats); 191 u64_stats_update_begin(&s->syncp); 192 s->cnt.conns++; 193 u64_stats_update_end(&s->syncp); 194 195 s = this_cpu_ptr(ipvs->tot_stats.cpustats); 196 u64_stats_update_begin(&s->syncp); 197 s->cnt.conns++; 198 u64_stats_update_end(&s->syncp); 199 } 200 201 202 static inline void 203 ip_vs_set_state(struct ip_vs_conn *cp, int direction, 204 const struct sk_buff *skb, 205 struct ip_vs_proto_data *pd) 206 { 207 if (likely(pd->pp->state_transition)) 208 pd->pp->state_transition(cp, direction, skb, pd); 209 } 210 211 static inline int 212 ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc, 213 struct sk_buff *skb, int protocol, 214 const union nf_inet_addr *caddr, __be16 cport, 215 const union nf_inet_addr *vaddr, __be16 vport, 216 struct ip_vs_conn_param *p) 217 { 218 ip_vs_conn_fill_param(svc->ipvs, svc->af, protocol, caddr, cport, vaddr, 219 vport, p); 220 p->pe = rcu_dereference(svc->pe); 221 if (p->pe && p->pe->fill_param) 222 return p->pe->fill_param(p, skb); 223 224 return 0; 225 } 226 227 /* 228 * IPVS persistent scheduling function 229 * It creates a connection entry according to its template if exists, 230 * or selects a server and creates a connection entry plus a template. 231 * Locking: we are svc user (svc->refcnt), so we hold all dests too 232 * Protocols supported: TCP, UDP 233 */ 234 static struct ip_vs_conn * 235 ip_vs_sched_persist(struct ip_vs_service *svc, 236 struct sk_buff *skb, __be16 src_port, __be16 dst_port, 237 int *ignored, struct ip_vs_iphdr *iph) 238 { 239 struct ip_vs_conn *cp = NULL; 240 struct ip_vs_dest *dest; 241 struct ip_vs_conn *ct; 242 __be16 dport = 0; /* destination port to forward */ 243 unsigned int flags; 244 struct ip_vs_conn_param param; 245 const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) }; 246 union nf_inet_addr snet; /* source network of the client, 247 after masking */ 248 const union nf_inet_addr *src_addr, *dst_addr; 249 250 if (likely(!ip_vs_iph_inverse(iph))) { 251 src_addr = &iph->saddr; 252 dst_addr = &iph->daddr; 253 } else { 254 src_addr = &iph->daddr; 255 dst_addr = &iph->saddr; 256 } 257 258 259 /* Mask saddr with the netmask to adjust template granularity */ 260 #ifdef CONFIG_IP_VS_IPV6 261 if (svc->af == AF_INET6) 262 ipv6_addr_prefix(&snet.in6, &src_addr->in6, 263 (__force __u32) svc->netmask); 264 else 265 #endif 266 snet.ip = src_addr->ip & svc->netmask; 267 268 IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u " 269 "mnet %s\n", 270 IP_VS_DBG_ADDR(svc->af, src_addr), ntohs(src_port), 271 IP_VS_DBG_ADDR(svc->af, dst_addr), ntohs(dst_port), 272 IP_VS_DBG_ADDR(svc->af, &snet)); 273 274 /* 275 * As far as we know, FTP is a very complicated network protocol, and 276 * it uses control connection and data connections. For active FTP, 277 * FTP server initialize data connection to the client, its source port 278 * is often 20. For passive FTP, FTP server tells the clients the port 279 * that it passively listens to, and the client issues the data 280 * connection. In the tunneling or direct routing mode, the load 281 * balancer is on the client-to-server half of connection, the port 282 * number is unknown to the load balancer. So, a conn template like 283 * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP 284 * service, and a template like <caddr, 0, vaddr, vport, daddr, dport> 285 * is created for other persistent services. 286 */ 287 { 288 int protocol = iph->protocol; 289 const union nf_inet_addr *vaddr = dst_addr; 290 __be16 vport = 0; 291 292 if (dst_port == svc->port) { 293 /* non-FTP template: 294 * <protocol, caddr, 0, vaddr, vport, daddr, dport> 295 * FTP template: 296 * <protocol, caddr, 0, vaddr, 0, daddr, 0> 297 */ 298 if (svc->port != FTPPORT) 299 vport = dst_port; 300 } else { 301 /* Note: persistent fwmark-based services and 302 * persistent port zero service are handled here. 303 * fwmark template: 304 * <IPPROTO_IP,caddr,0,fwmark,0,daddr,0> 305 * port zero template: 306 * <protocol,caddr,0,vaddr,0,daddr,0> 307 */ 308 if (svc->fwmark) { 309 protocol = IPPROTO_IP; 310 vaddr = &fwmark; 311 } 312 } 313 /* return *ignored = -1 so NF_DROP can be used */ 314 if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0, 315 vaddr, vport, ¶m) < 0) { 316 *ignored = -1; 317 return NULL; 318 } 319 } 320 321 /* Check if a template already exists */ 322 ct = ip_vs_ct_in_get(¶m); 323 if (!ct || !ip_vs_check_template(ct)) { 324 struct ip_vs_scheduler *sched; 325 326 /* 327 * No template found or the dest of the connection 328 * template is not available. 329 * return *ignored=0 i.e. ICMP and NF_DROP 330 */ 331 sched = rcu_dereference(svc->scheduler); 332 if (sched) { 333 /* read svc->sched_data after svc->scheduler */ 334 smp_rmb(); 335 dest = sched->schedule(svc, skb, iph); 336 } else { 337 dest = NULL; 338 } 339 if (!dest) { 340 IP_VS_DBG(1, "p-schedule: no dest found.\n"); 341 kfree(param.pe_data); 342 *ignored = 0; 343 return NULL; 344 } 345 346 if (dst_port == svc->port && svc->port != FTPPORT) 347 dport = dest->port; 348 349 /* Create a template 350 * This adds param.pe_data to the template, 351 * and thus param.pe_data will be destroyed 352 * when the template expires */ 353 ct = ip_vs_conn_new(¶m, dest->af, &dest->addr, dport, 354 IP_VS_CONN_F_TEMPLATE, dest, skb->mark); 355 if (ct == NULL) { 356 kfree(param.pe_data); 357 *ignored = -1; 358 return NULL; 359 } 360 361 ct->timeout = svc->timeout; 362 } else { 363 /* set destination with the found template */ 364 dest = ct->dest; 365 kfree(param.pe_data); 366 } 367 368 dport = dst_port; 369 if (dport == svc->port && dest->port) 370 dport = dest->port; 371 372 flags = (svc->flags & IP_VS_SVC_F_ONEPACKET 373 && iph->protocol == IPPROTO_UDP) ? 374 IP_VS_CONN_F_ONE_PACKET : 0; 375 376 /* 377 * Create a new connection according to the template 378 */ 379 ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol, src_addr, 380 src_port, dst_addr, dst_port, ¶m); 381 382 cp = ip_vs_conn_new(¶m, dest->af, &dest->addr, dport, flags, dest, 383 skb->mark); 384 if (cp == NULL) { 385 ip_vs_conn_put(ct); 386 *ignored = -1; 387 return NULL; 388 } 389 390 /* 391 * Add its control 392 */ 393 ip_vs_control_add(cp, ct); 394 ip_vs_conn_put(ct); 395 396 ip_vs_conn_stats(cp, svc); 397 return cp; 398 } 399 400 401 /* 402 * IPVS main scheduling function 403 * It selects a server according to the virtual service, and 404 * creates a connection entry. 405 * Protocols supported: TCP, UDP 406 * 407 * Usage of *ignored 408 * 409 * 1 : protocol tried to schedule (eg. on SYN), found svc but the 410 * svc/scheduler decides that this packet should be accepted with 411 * NF_ACCEPT because it must not be scheduled. 412 * 413 * 0 : scheduler can not find destination, so try bypass or 414 * return ICMP and then NF_DROP (ip_vs_leave). 415 * 416 * -1 : scheduler tried to schedule but fatal error occurred, eg. 417 * ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param 418 * failure such as missing Call-ID, ENOMEM on skb_linearize 419 * or pe_data. In this case we should return NF_DROP without 420 * any attempts to send ICMP with ip_vs_leave. 421 */ 422 struct ip_vs_conn * 423 ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb, 424 struct ip_vs_proto_data *pd, int *ignored, 425 struct ip_vs_iphdr *iph) 426 { 427 struct ip_vs_protocol *pp = pd->pp; 428 struct ip_vs_conn *cp = NULL; 429 struct ip_vs_scheduler *sched; 430 struct ip_vs_dest *dest; 431 __be16 _ports[2], *pptr, cport, vport; 432 const void *caddr, *vaddr; 433 unsigned int flags; 434 435 *ignored = 1; 436 /* 437 * IPv6 frags, only the first hit here. 438 */ 439 pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph); 440 if (pptr == NULL) 441 return NULL; 442 443 if (likely(!ip_vs_iph_inverse(iph))) { 444 cport = pptr[0]; 445 caddr = &iph->saddr; 446 vport = pptr[1]; 447 vaddr = &iph->daddr; 448 } else { 449 cport = pptr[1]; 450 caddr = &iph->daddr; 451 vport = pptr[0]; 452 vaddr = &iph->saddr; 453 } 454 455 /* 456 * FTPDATA needs this check when using local real server. 457 * Never schedule Active FTPDATA connections from real server. 458 * For LVS-NAT they must be already created. For other methods 459 * with persistence the connection is created on SYN+ACK. 460 */ 461 if (cport == FTPDATA) { 462 IP_VS_DBG_PKT(12, svc->af, pp, skb, iph->off, 463 "Not scheduling FTPDATA"); 464 return NULL; 465 } 466 467 /* 468 * Do not schedule replies from local real server. 469 */ 470 if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK)) { 471 iph->hdr_flags ^= IP_VS_HDR_INVERSE; 472 cp = pp->conn_in_get(svc->ipvs, svc->af, skb, iph); 473 iph->hdr_flags ^= IP_VS_HDR_INVERSE; 474 475 if (cp) { 476 IP_VS_DBG_PKT(12, svc->af, pp, skb, iph->off, 477 "Not scheduling reply for existing" 478 " connection"); 479 __ip_vs_conn_put(cp); 480 return NULL; 481 } 482 } 483 484 /* 485 * Persistent service 486 */ 487 if (svc->flags & IP_VS_SVC_F_PERSISTENT) 488 return ip_vs_sched_persist(svc, skb, cport, vport, ignored, 489 iph); 490 491 *ignored = 0; 492 493 /* 494 * Non-persistent service 495 */ 496 if (!svc->fwmark && vport != svc->port) { 497 if (!svc->port) 498 pr_err("Schedule: port zero only supported " 499 "in persistent services, " 500 "check your ipvs configuration\n"); 501 return NULL; 502 } 503 504 sched = rcu_dereference(svc->scheduler); 505 if (sched) { 506 /* read svc->sched_data after svc->scheduler */ 507 smp_rmb(); 508 dest = sched->schedule(svc, skb, iph); 509 } else { 510 dest = NULL; 511 } 512 if (dest == NULL) { 513 IP_VS_DBG(1, "Schedule: no dest found.\n"); 514 return NULL; 515 } 516 517 flags = (svc->flags & IP_VS_SVC_F_ONEPACKET 518 && iph->protocol == IPPROTO_UDP) ? 519 IP_VS_CONN_F_ONE_PACKET : 0; 520 521 /* 522 * Create a connection entry. 523 */ 524 { 525 struct ip_vs_conn_param p; 526 527 ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol, 528 caddr, cport, vaddr, vport, &p); 529 cp = ip_vs_conn_new(&p, dest->af, &dest->addr, 530 dest->port ? dest->port : vport, 531 flags, dest, skb->mark); 532 if (!cp) { 533 *ignored = -1; 534 return NULL; 535 } 536 } 537 538 IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u " 539 "d:%s:%u conn->flags:%X conn->refcnt:%d\n", 540 ip_vs_fwd_tag(cp), 541 IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport), 542 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport), 543 IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport), 544 cp->flags, atomic_read(&cp->refcnt)); 545 546 ip_vs_conn_stats(cp, svc); 547 return cp; 548 } 549 550 static inline int ip_vs_addr_is_unicast(struct net *net, int af, 551 union nf_inet_addr *addr) 552 { 553 #ifdef CONFIG_IP_VS_IPV6 554 if (af == AF_INET6) 555 return ipv6_addr_type(&addr->in6) & IPV6_ADDR_UNICAST; 556 #endif 557 return (inet_addr_type(net, addr->ip) == RTN_UNICAST); 558 } 559 560 /* 561 * Pass or drop the packet. 562 * Called by ip_vs_in, when the virtual service is available but 563 * no destination is available for a new connection. 564 */ 565 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb, 566 struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph) 567 { 568 __be16 _ports[2], *pptr, dport; 569 struct netns_ipvs *ipvs = svc->ipvs; 570 struct net *net = ipvs->net; 571 572 pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph); 573 if (!pptr) 574 return NF_DROP; 575 dport = likely(!ip_vs_iph_inverse(iph)) ? pptr[1] : pptr[0]; 576 577 /* if it is fwmark-based service, the cache_bypass sysctl is up 578 and the destination is a non-local unicast, then create 579 a cache_bypass connection entry */ 580 if (sysctl_cache_bypass(ipvs) && svc->fwmark && 581 !(iph->hdr_flags & (IP_VS_HDR_INVERSE | IP_VS_HDR_ICMP)) && 582 ip_vs_addr_is_unicast(net, svc->af, &iph->daddr)) { 583 int ret; 584 struct ip_vs_conn *cp; 585 unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET && 586 iph->protocol == IPPROTO_UDP) ? 587 IP_VS_CONN_F_ONE_PACKET : 0; 588 union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } }; 589 590 /* create a new connection entry */ 591 IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__); 592 { 593 struct ip_vs_conn_param p; 594 ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol, 595 &iph->saddr, pptr[0], 596 &iph->daddr, pptr[1], &p); 597 cp = ip_vs_conn_new(&p, svc->af, &daddr, 0, 598 IP_VS_CONN_F_BYPASS | flags, 599 NULL, skb->mark); 600 if (!cp) 601 return NF_DROP; 602 } 603 604 /* statistics */ 605 ip_vs_in_stats(cp, skb); 606 607 /* set state */ 608 ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd); 609 610 /* transmit the first SYN packet */ 611 ret = cp->packet_xmit(skb, cp, pd->pp, iph); 612 /* do not touch skb anymore */ 613 614 atomic_inc(&cp->in_pkts); 615 ip_vs_conn_put(cp); 616 return ret; 617 } 618 619 /* 620 * When the virtual ftp service is presented, packets destined 621 * for other services on the VIP may get here (except services 622 * listed in the ipvs table), pass the packets, because it is 623 * not ipvs job to decide to drop the packets. 624 */ 625 if (svc->port == FTPPORT && dport != FTPPORT) 626 return NF_ACCEPT; 627 628 if (unlikely(ip_vs_iph_icmp(iph))) 629 return NF_DROP; 630 631 /* 632 * Notify the client that the destination is unreachable, and 633 * release the socket buffer. 634 * Since it is in IP layer, the TCP socket is not actually 635 * created, the TCP RST packet cannot be sent, instead that 636 * ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ 637 */ 638 #ifdef CONFIG_IP_VS_IPV6 639 if (svc->af == AF_INET6) { 640 if (!skb->dev) 641 skb->dev = net->loopback_dev; 642 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 643 } else 644 #endif 645 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 646 647 return NF_DROP; 648 } 649 650 #ifdef CONFIG_SYSCTL 651 652 static int sysctl_snat_reroute(struct netns_ipvs *ipvs) 653 { 654 return ipvs->sysctl_snat_reroute; 655 } 656 657 static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs) 658 { 659 return ipvs->sysctl_nat_icmp_send; 660 } 661 662 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) 663 { 664 return ipvs->sysctl_expire_nodest_conn; 665 } 666 667 #else 668 669 static int sysctl_snat_reroute(struct netns_ipvs *ipvs) { return 0; } 670 static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs) { return 0; } 671 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) { return 0; } 672 673 #endif 674 675 __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset) 676 { 677 return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0)); 678 } 679 680 static inline enum ip_defrag_users ip_vs_defrag_user(unsigned int hooknum) 681 { 682 if (NF_INET_LOCAL_IN == hooknum) 683 return IP_DEFRAG_VS_IN; 684 if (NF_INET_FORWARD == hooknum) 685 return IP_DEFRAG_VS_FWD; 686 return IP_DEFRAG_VS_OUT; 687 } 688 689 static inline int ip_vs_gather_frags(struct netns_ipvs *ipvs, 690 struct sk_buff *skb, u_int32_t user) 691 { 692 int err; 693 694 local_bh_disable(); 695 err = ip_defrag(ipvs->net, skb, user); 696 local_bh_enable(); 697 if (!err) 698 ip_send_check(ip_hdr(skb)); 699 700 return err; 701 } 702 703 static int ip_vs_route_me_harder(struct netns_ipvs *ipvs, int af, 704 struct sk_buff *skb, unsigned int hooknum) 705 { 706 if (!sysctl_snat_reroute(ipvs)) 707 return 0; 708 /* Reroute replies only to remote clients (FORWARD and LOCAL_OUT) */ 709 if (NF_INET_LOCAL_IN == hooknum) 710 return 0; 711 #ifdef CONFIG_IP_VS_IPV6 712 if (af == AF_INET6) { 713 struct dst_entry *dst = skb_dst(skb); 714 715 if (dst->dev && !(dst->dev->flags & IFF_LOOPBACK) && 716 ip6_route_me_harder(ipvs->net, skb) != 0) 717 return 1; 718 } else 719 #endif 720 if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL) && 721 ip_route_me_harder(ipvs->net, skb, RTN_LOCAL) != 0) 722 return 1; 723 724 return 0; 725 } 726 727 /* 728 * Packet has been made sufficiently writable in caller 729 * - inout: 1=in->out, 0=out->in 730 */ 731 void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp, 732 struct ip_vs_conn *cp, int inout) 733 { 734 struct iphdr *iph = ip_hdr(skb); 735 unsigned int icmp_offset = iph->ihl*4; 736 struct icmphdr *icmph = (struct icmphdr *)(skb_network_header(skb) + 737 icmp_offset); 738 struct iphdr *ciph = (struct iphdr *)(icmph + 1); 739 740 if (inout) { 741 iph->saddr = cp->vaddr.ip; 742 ip_send_check(iph); 743 ciph->daddr = cp->vaddr.ip; 744 ip_send_check(ciph); 745 } else { 746 iph->daddr = cp->daddr.ip; 747 ip_send_check(iph); 748 ciph->saddr = cp->daddr.ip; 749 ip_send_check(ciph); 750 } 751 752 /* the TCP/UDP/SCTP port */ 753 if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol || 754 IPPROTO_SCTP == ciph->protocol) { 755 __be16 *ports = (void *)ciph + ciph->ihl*4; 756 757 if (inout) 758 ports[1] = cp->vport; 759 else 760 ports[0] = cp->dport; 761 } 762 763 /* And finally the ICMP checksum */ 764 icmph->checksum = 0; 765 icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset); 766 skb->ip_summed = CHECKSUM_UNNECESSARY; 767 768 if (inout) 769 IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph, 770 "Forwarding altered outgoing ICMP"); 771 else 772 IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph, 773 "Forwarding altered incoming ICMP"); 774 } 775 776 #ifdef CONFIG_IP_VS_IPV6 777 void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp, 778 struct ip_vs_conn *cp, int inout) 779 { 780 struct ipv6hdr *iph = ipv6_hdr(skb); 781 unsigned int icmp_offset = 0; 782 unsigned int offs = 0; /* header offset*/ 783 int protocol; 784 struct icmp6hdr *icmph; 785 struct ipv6hdr *ciph; 786 unsigned short fragoffs; 787 788 ipv6_find_hdr(skb, &icmp_offset, IPPROTO_ICMPV6, &fragoffs, NULL); 789 icmph = (struct icmp6hdr *)(skb_network_header(skb) + icmp_offset); 790 offs = icmp_offset + sizeof(struct icmp6hdr); 791 ciph = (struct ipv6hdr *)(skb_network_header(skb) + offs); 792 793 protocol = ipv6_find_hdr(skb, &offs, -1, &fragoffs, NULL); 794 795 if (inout) { 796 iph->saddr = cp->vaddr.in6; 797 ciph->daddr = cp->vaddr.in6; 798 } else { 799 iph->daddr = cp->daddr.in6; 800 ciph->saddr = cp->daddr.in6; 801 } 802 803 /* the TCP/UDP/SCTP port */ 804 if (!fragoffs && (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol || 805 IPPROTO_SCTP == protocol)) { 806 __be16 *ports = (void *)(skb_network_header(skb) + offs); 807 808 IP_VS_DBG(11, "%s() changed port %d to %d\n", __func__, 809 ntohs(inout ? ports[1] : ports[0]), 810 ntohs(inout ? cp->vport : cp->dport)); 811 if (inout) 812 ports[1] = cp->vport; 813 else 814 ports[0] = cp->dport; 815 } 816 817 /* And finally the ICMP checksum */ 818 icmph->icmp6_cksum = ~csum_ipv6_magic(&iph->saddr, &iph->daddr, 819 skb->len - icmp_offset, 820 IPPROTO_ICMPV6, 0); 821 skb->csum_start = skb_network_header(skb) - skb->head + icmp_offset; 822 skb->csum_offset = offsetof(struct icmp6hdr, icmp6_cksum); 823 skb->ip_summed = CHECKSUM_PARTIAL; 824 825 if (inout) 826 IP_VS_DBG_PKT(11, AF_INET6, pp, skb, 827 (void *)ciph - (void *)iph, 828 "Forwarding altered outgoing ICMPv6"); 829 else 830 IP_VS_DBG_PKT(11, AF_INET6, pp, skb, 831 (void *)ciph - (void *)iph, 832 "Forwarding altered incoming ICMPv6"); 833 } 834 #endif 835 836 /* Handle relevant response ICMP messages - forward to the right 837 * destination host. 838 */ 839 static int handle_response_icmp(int af, struct sk_buff *skb, 840 union nf_inet_addr *snet, 841 __u8 protocol, struct ip_vs_conn *cp, 842 struct ip_vs_protocol *pp, 843 unsigned int offset, unsigned int ihl, 844 unsigned int hooknum) 845 { 846 unsigned int verdict = NF_DROP; 847 848 if (IP_VS_FWD_METHOD(cp) != 0) { 849 pr_err("shouldn't reach here, because the box is on the " 850 "half connection in the tun/dr module.\n"); 851 } 852 853 /* Ensure the checksum is correct */ 854 if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) { 855 /* Failed checksum! */ 856 IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n", 857 IP_VS_DBG_ADDR(af, snet)); 858 goto out; 859 } 860 861 if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol || 862 IPPROTO_SCTP == protocol) 863 offset += 2 * sizeof(__u16); 864 if (!skb_make_writable(skb, offset)) 865 goto out; 866 867 #ifdef CONFIG_IP_VS_IPV6 868 if (af == AF_INET6) 869 ip_vs_nat_icmp_v6(skb, pp, cp, 1); 870 else 871 #endif 872 ip_vs_nat_icmp(skb, pp, cp, 1); 873 874 if (ip_vs_route_me_harder(cp->ipvs, af, skb, hooknum)) 875 goto out; 876 877 /* do the statistics and put it back */ 878 ip_vs_out_stats(cp, skb); 879 880 skb->ipvs_property = 1; 881 if (!(cp->flags & IP_VS_CONN_F_NFCT)) 882 ip_vs_notrack(skb); 883 else 884 ip_vs_update_conntrack(skb, cp, 0); 885 verdict = NF_ACCEPT; 886 887 out: 888 __ip_vs_conn_put(cp); 889 890 return verdict; 891 } 892 893 /* 894 * Handle ICMP messages in the inside-to-outside direction (outgoing). 895 * Find any that might be relevant, check against existing connections. 896 * Currently handles error types - unreachable, quench, ttl exceeded. 897 */ 898 static int ip_vs_out_icmp(struct netns_ipvs *ipvs, struct sk_buff *skb, 899 int *related, unsigned int hooknum) 900 { 901 struct iphdr *iph; 902 struct icmphdr _icmph, *ic; 903 struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */ 904 struct ip_vs_iphdr ciph; 905 struct ip_vs_conn *cp; 906 struct ip_vs_protocol *pp; 907 unsigned int offset, ihl; 908 union nf_inet_addr snet; 909 910 *related = 1; 911 912 /* reassemble IP fragments */ 913 if (ip_is_fragment(ip_hdr(skb))) { 914 if (ip_vs_gather_frags(ipvs, skb, ip_vs_defrag_user(hooknum))) 915 return NF_STOLEN; 916 } 917 918 iph = ip_hdr(skb); 919 offset = ihl = iph->ihl * 4; 920 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); 921 if (ic == NULL) 922 return NF_DROP; 923 924 IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %pI4->%pI4\n", 925 ic->type, ntohs(icmp_id(ic)), 926 &iph->saddr, &iph->daddr); 927 928 /* 929 * Work through seeing if this is for us. 930 * These checks are supposed to be in an order that means easy 931 * things are checked first to speed up processing.... however 932 * this means that some packets will manage to get a long way 933 * down this stack and then be rejected, but that's life. 934 */ 935 if ((ic->type != ICMP_DEST_UNREACH) && 936 (ic->type != ICMP_SOURCE_QUENCH) && 937 (ic->type != ICMP_TIME_EXCEEDED)) { 938 *related = 0; 939 return NF_ACCEPT; 940 } 941 942 /* Now find the contained IP header */ 943 offset += sizeof(_icmph); 944 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); 945 if (cih == NULL) 946 return NF_ACCEPT; /* The packet looks wrong, ignore */ 947 948 pp = ip_vs_proto_get(cih->protocol); 949 if (!pp) 950 return NF_ACCEPT; 951 952 /* Is the embedded protocol header present? */ 953 if (unlikely(cih->frag_off & htons(IP_OFFSET) && 954 pp->dont_defrag)) 955 return NF_ACCEPT; 956 957 IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset, 958 "Checking outgoing ICMP for"); 959 960 ip_vs_fill_iph_skb_icmp(AF_INET, skb, offset, true, &ciph); 961 962 /* The embedded headers contain source and dest in reverse order */ 963 cp = pp->conn_out_get(ipvs, AF_INET, skb, &ciph); 964 if (!cp) 965 return NF_ACCEPT; 966 967 snet.ip = iph->saddr; 968 return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp, 969 pp, ciph.len, ihl, hooknum); 970 } 971 972 #ifdef CONFIG_IP_VS_IPV6 973 static int ip_vs_out_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb, 974 int *related, unsigned int hooknum, 975 struct ip_vs_iphdr *ipvsh) 976 { 977 struct icmp6hdr _icmph, *ic; 978 struct ip_vs_iphdr ciph = {.flags = 0, .fragoffs = 0};/*Contained IP */ 979 struct ip_vs_conn *cp; 980 struct ip_vs_protocol *pp; 981 union nf_inet_addr snet; 982 unsigned int offset; 983 984 *related = 1; 985 ic = frag_safe_skb_hp(skb, ipvsh->len, sizeof(_icmph), &_icmph, ipvsh); 986 if (ic == NULL) 987 return NF_DROP; 988 989 /* 990 * Work through seeing if this is for us. 991 * These checks are supposed to be in an order that means easy 992 * things are checked first to speed up processing.... however 993 * this means that some packets will manage to get a long way 994 * down this stack and then be rejected, but that's life. 995 */ 996 if (ic->icmp6_type & ICMPV6_INFOMSG_MASK) { 997 *related = 0; 998 return NF_ACCEPT; 999 } 1000 /* Fragment header that is before ICMP header tells us that: 1001 * it's not an error message since they can't be fragmented. 1002 */ 1003 if (ipvsh->flags & IP6_FH_F_FRAG) 1004 return NF_DROP; 1005 1006 IP_VS_DBG(8, "Outgoing ICMPv6 (%d,%d) %pI6c->%pI6c\n", 1007 ic->icmp6_type, ntohs(icmpv6_id(ic)), 1008 &ipvsh->saddr, &ipvsh->daddr); 1009 1010 if (!ip_vs_fill_iph_skb_icmp(AF_INET6, skb, ipvsh->len + sizeof(_icmph), 1011 true, &ciph)) 1012 return NF_ACCEPT; /* The packet looks wrong, ignore */ 1013 1014 pp = ip_vs_proto_get(ciph.protocol); 1015 if (!pp) 1016 return NF_ACCEPT; 1017 1018 /* The embedded headers contain source and dest in reverse order */ 1019 cp = pp->conn_out_get(ipvs, AF_INET6, skb, &ciph); 1020 if (!cp) 1021 return NF_ACCEPT; 1022 1023 snet.in6 = ciph.saddr.in6; 1024 offset = ciph.len; 1025 return handle_response_icmp(AF_INET6, skb, &snet, ciph.protocol, cp, 1026 pp, offset, sizeof(struct ipv6hdr), 1027 hooknum); 1028 } 1029 #endif 1030 1031 /* 1032 * Check if sctp chunc is ABORT chunk 1033 */ 1034 static inline int is_sctp_abort(const struct sk_buff *skb, int nh_len) 1035 { 1036 sctp_chunkhdr_t *sch, schunk; 1037 sch = skb_header_pointer(skb, nh_len + sizeof(sctp_sctphdr_t), 1038 sizeof(schunk), &schunk); 1039 if (sch == NULL) 1040 return 0; 1041 if (sch->type == SCTP_CID_ABORT) 1042 return 1; 1043 return 0; 1044 } 1045 1046 static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len) 1047 { 1048 struct tcphdr _tcph, *th; 1049 1050 th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph); 1051 if (th == NULL) 1052 return 0; 1053 return th->rst; 1054 } 1055 1056 static inline bool is_new_conn(const struct sk_buff *skb, 1057 struct ip_vs_iphdr *iph) 1058 { 1059 switch (iph->protocol) { 1060 case IPPROTO_TCP: { 1061 struct tcphdr _tcph, *th; 1062 1063 th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph); 1064 if (th == NULL) 1065 return false; 1066 return th->syn; 1067 } 1068 case IPPROTO_SCTP: { 1069 sctp_chunkhdr_t *sch, schunk; 1070 1071 sch = skb_header_pointer(skb, iph->len + sizeof(sctp_sctphdr_t), 1072 sizeof(schunk), &schunk); 1073 if (sch == NULL) 1074 return false; 1075 return sch->type == SCTP_CID_INIT; 1076 } 1077 default: 1078 return false; 1079 } 1080 } 1081 1082 static inline bool is_new_conn_expected(const struct ip_vs_conn *cp, 1083 int conn_reuse_mode) 1084 { 1085 /* Controlled (FTP DATA or persistence)? */ 1086 if (cp->control) 1087 return false; 1088 1089 switch (cp->protocol) { 1090 case IPPROTO_TCP: 1091 return (cp->state == IP_VS_TCP_S_TIME_WAIT) || 1092 ((conn_reuse_mode & 2) && 1093 (cp->state == IP_VS_TCP_S_FIN_WAIT) && 1094 (cp->flags & IP_VS_CONN_F_NOOUTPUT)); 1095 case IPPROTO_SCTP: 1096 return cp->state == IP_VS_SCTP_S_CLOSED; 1097 default: 1098 return false; 1099 } 1100 } 1101 1102 /* Handle response packets: rewrite addresses and send away... 1103 */ 1104 static unsigned int 1105 handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd, 1106 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph, 1107 unsigned int hooknum) 1108 { 1109 struct ip_vs_protocol *pp = pd->pp; 1110 1111 IP_VS_DBG_PKT(11, af, pp, skb, iph->off, "Outgoing packet"); 1112 1113 if (!skb_make_writable(skb, iph->len)) 1114 goto drop; 1115 1116 /* mangle the packet */ 1117 if (pp->snat_handler && !pp->snat_handler(skb, pp, cp, iph)) 1118 goto drop; 1119 1120 #ifdef CONFIG_IP_VS_IPV6 1121 if (af == AF_INET6) 1122 ipv6_hdr(skb)->saddr = cp->vaddr.in6; 1123 else 1124 #endif 1125 { 1126 ip_hdr(skb)->saddr = cp->vaddr.ip; 1127 ip_send_check(ip_hdr(skb)); 1128 } 1129 1130 /* 1131 * nf_iterate does not expect change in the skb->dst->dev. 1132 * It looks like it is not fatal to enable this code for hooks 1133 * where our handlers are at the end of the chain list and 1134 * when all next handlers use skb->dst->dev and not outdev. 1135 * It will definitely route properly the inout NAT traffic 1136 * when multiple paths are used. 1137 */ 1138 1139 /* For policy routing, packets originating from this 1140 * machine itself may be routed differently to packets 1141 * passing through. We want this packet to be routed as 1142 * if it came from this machine itself. So re-compute 1143 * the routing information. 1144 */ 1145 if (ip_vs_route_me_harder(cp->ipvs, af, skb, hooknum)) 1146 goto drop; 1147 1148 IP_VS_DBG_PKT(10, af, pp, skb, iph->off, "After SNAT"); 1149 1150 ip_vs_out_stats(cp, skb); 1151 ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd); 1152 skb->ipvs_property = 1; 1153 if (!(cp->flags & IP_VS_CONN_F_NFCT)) 1154 ip_vs_notrack(skb); 1155 else 1156 ip_vs_update_conntrack(skb, cp, 0); 1157 ip_vs_conn_put(cp); 1158 1159 LeaveFunction(11); 1160 return NF_ACCEPT; 1161 1162 drop: 1163 ip_vs_conn_put(cp); 1164 kfree_skb(skb); 1165 LeaveFunction(11); 1166 return NF_STOLEN; 1167 } 1168 1169 /* 1170 * Check if outgoing packet belongs to the established ip_vs_conn. 1171 */ 1172 static unsigned int 1173 ip_vs_out(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int af) 1174 { 1175 struct ip_vs_iphdr iph; 1176 struct ip_vs_protocol *pp; 1177 struct ip_vs_proto_data *pd; 1178 struct ip_vs_conn *cp; 1179 struct sock *sk; 1180 1181 EnterFunction(11); 1182 1183 /* Already marked as IPVS request or reply? */ 1184 if (skb->ipvs_property) 1185 return NF_ACCEPT; 1186 1187 sk = skb_to_full_sk(skb); 1188 /* Bad... Do not break raw sockets */ 1189 if (unlikely(sk && hooknum == NF_INET_LOCAL_OUT && 1190 af == AF_INET)) { 1191 1192 if (sk->sk_family == PF_INET && inet_sk(sk)->nodefrag) 1193 return NF_ACCEPT; 1194 } 1195 1196 if (unlikely(!skb_dst(skb))) 1197 return NF_ACCEPT; 1198 1199 if (!ipvs->enable) 1200 return NF_ACCEPT; 1201 1202 ip_vs_fill_iph_skb(af, skb, false, &iph); 1203 #ifdef CONFIG_IP_VS_IPV6 1204 if (af == AF_INET6) { 1205 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) { 1206 int related; 1207 int verdict = ip_vs_out_icmp_v6(ipvs, skb, &related, 1208 hooknum, &iph); 1209 1210 if (related) 1211 return verdict; 1212 } 1213 } else 1214 #endif 1215 if (unlikely(iph.protocol == IPPROTO_ICMP)) { 1216 int related; 1217 int verdict = ip_vs_out_icmp(ipvs, skb, &related, hooknum); 1218 1219 if (related) 1220 return verdict; 1221 } 1222 1223 pd = ip_vs_proto_data_get(ipvs, iph.protocol); 1224 if (unlikely(!pd)) 1225 return NF_ACCEPT; 1226 pp = pd->pp; 1227 1228 /* reassemble IP fragments */ 1229 #ifdef CONFIG_IP_VS_IPV6 1230 if (af == AF_INET) 1231 #endif 1232 if (unlikely(ip_is_fragment(ip_hdr(skb)) && !pp->dont_defrag)) { 1233 if (ip_vs_gather_frags(ipvs, skb, 1234 ip_vs_defrag_user(hooknum))) 1235 return NF_STOLEN; 1236 1237 ip_vs_fill_iph_skb(AF_INET, skb, false, &iph); 1238 } 1239 1240 /* 1241 * Check if the packet belongs to an existing entry 1242 */ 1243 cp = pp->conn_out_get(ipvs, af, skb, &iph); 1244 1245 if (likely(cp)) 1246 return handle_response(af, skb, pd, cp, &iph, hooknum); 1247 if (sysctl_nat_icmp_send(ipvs) && 1248 (pp->protocol == IPPROTO_TCP || 1249 pp->protocol == IPPROTO_UDP || 1250 pp->protocol == IPPROTO_SCTP)) { 1251 __be16 _ports[2], *pptr; 1252 1253 pptr = frag_safe_skb_hp(skb, iph.len, 1254 sizeof(_ports), _ports, &iph); 1255 if (pptr == NULL) 1256 return NF_ACCEPT; /* Not for me */ 1257 if (ip_vs_has_real_service(ipvs, af, iph.protocol, &iph.saddr, 1258 pptr[0])) { 1259 /* 1260 * Notify the real server: there is no 1261 * existing entry if it is not RST 1262 * packet or not TCP packet. 1263 */ 1264 if ((iph.protocol != IPPROTO_TCP && 1265 iph.protocol != IPPROTO_SCTP) 1266 || ((iph.protocol == IPPROTO_TCP 1267 && !is_tcp_reset(skb, iph.len)) 1268 || (iph.protocol == IPPROTO_SCTP 1269 && !is_sctp_abort(skb, 1270 iph.len)))) { 1271 #ifdef CONFIG_IP_VS_IPV6 1272 if (af == AF_INET6) { 1273 if (!skb->dev) 1274 skb->dev = ipvs->net->loopback_dev; 1275 icmpv6_send(skb, 1276 ICMPV6_DEST_UNREACH, 1277 ICMPV6_PORT_UNREACH, 1278 0); 1279 } else 1280 #endif 1281 icmp_send(skb, 1282 ICMP_DEST_UNREACH, 1283 ICMP_PORT_UNREACH, 0); 1284 return NF_DROP; 1285 } 1286 } 1287 } 1288 IP_VS_DBG_PKT(12, af, pp, skb, iph.off, 1289 "ip_vs_out: packet continues traversal as normal"); 1290 return NF_ACCEPT; 1291 } 1292 1293 /* 1294 * It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain, 1295 * used only for VS/NAT. 1296 * Check if packet is reply for established ip_vs_conn. 1297 */ 1298 static unsigned int 1299 ip_vs_reply4(void *priv, struct sk_buff *skb, 1300 const struct nf_hook_state *state) 1301 { 1302 return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET); 1303 } 1304 1305 /* 1306 * It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT. 1307 * Check if packet is reply for established ip_vs_conn. 1308 */ 1309 static unsigned int 1310 ip_vs_local_reply4(void *priv, struct sk_buff *skb, 1311 const struct nf_hook_state *state) 1312 { 1313 return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET); 1314 } 1315 1316 #ifdef CONFIG_IP_VS_IPV6 1317 1318 /* 1319 * It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain, 1320 * used only for VS/NAT. 1321 * Check if packet is reply for established ip_vs_conn. 1322 */ 1323 static unsigned int 1324 ip_vs_reply6(void *priv, struct sk_buff *skb, 1325 const struct nf_hook_state *state) 1326 { 1327 return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET6); 1328 } 1329 1330 /* 1331 * It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT. 1332 * Check if packet is reply for established ip_vs_conn. 1333 */ 1334 static unsigned int 1335 ip_vs_local_reply6(void *priv, struct sk_buff *skb, 1336 const struct nf_hook_state *state) 1337 { 1338 return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET6); 1339 } 1340 1341 #endif 1342 1343 static unsigned int 1344 ip_vs_try_to_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb, 1345 struct ip_vs_proto_data *pd, 1346 int *verdict, struct ip_vs_conn **cpp, 1347 struct ip_vs_iphdr *iph) 1348 { 1349 struct ip_vs_protocol *pp = pd->pp; 1350 1351 if (!iph->fragoffs) { 1352 /* No (second) fragments need to enter here, as nf_defrag_ipv6 1353 * replayed fragment zero will already have created the cp 1354 */ 1355 1356 /* Schedule and create new connection entry into cpp */ 1357 if (!pp->conn_schedule(ipvs, af, skb, pd, verdict, cpp, iph)) 1358 return 0; 1359 } 1360 1361 if (unlikely(!*cpp)) { 1362 /* sorry, all this trouble for a no-hit :) */ 1363 IP_VS_DBG_PKT(12, af, pp, skb, iph->off, 1364 "ip_vs_in: packet continues traversal as normal"); 1365 if (iph->fragoffs) { 1366 /* Fragment that couldn't be mapped to a conn entry 1367 * is missing module nf_defrag_ipv6 1368 */ 1369 IP_VS_DBG_RL("Unhandled frag, load nf_defrag_ipv6\n"); 1370 IP_VS_DBG_PKT(7, af, pp, skb, iph->off, 1371 "unhandled fragment"); 1372 } 1373 *verdict = NF_ACCEPT; 1374 return 0; 1375 } 1376 1377 return 1; 1378 } 1379 1380 /* 1381 * Handle ICMP messages in the outside-to-inside direction (incoming). 1382 * Find any that might be relevant, check against existing connections, 1383 * forward to the right destination host if relevant. 1384 * Currently handles error types - unreachable, quench, ttl exceeded. 1385 */ 1386 static int 1387 ip_vs_in_icmp(struct netns_ipvs *ipvs, struct sk_buff *skb, int *related, 1388 unsigned int hooknum) 1389 { 1390 struct iphdr *iph; 1391 struct icmphdr _icmph, *ic; 1392 struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */ 1393 struct ip_vs_iphdr ciph; 1394 struct ip_vs_conn *cp; 1395 struct ip_vs_protocol *pp; 1396 struct ip_vs_proto_data *pd; 1397 unsigned int offset, offset2, ihl, verdict; 1398 bool ipip, new_cp = false; 1399 1400 *related = 1; 1401 1402 /* reassemble IP fragments */ 1403 if (ip_is_fragment(ip_hdr(skb))) { 1404 if (ip_vs_gather_frags(ipvs, skb, ip_vs_defrag_user(hooknum))) 1405 return NF_STOLEN; 1406 } 1407 1408 iph = ip_hdr(skb); 1409 offset = ihl = iph->ihl * 4; 1410 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); 1411 if (ic == NULL) 1412 return NF_DROP; 1413 1414 IP_VS_DBG(12, "Incoming ICMP (%d,%d) %pI4->%pI4\n", 1415 ic->type, ntohs(icmp_id(ic)), 1416 &iph->saddr, &iph->daddr); 1417 1418 /* 1419 * Work through seeing if this is for us. 1420 * These checks are supposed to be in an order that means easy 1421 * things are checked first to speed up processing.... however 1422 * this means that some packets will manage to get a long way 1423 * down this stack and then be rejected, but that's life. 1424 */ 1425 if ((ic->type != ICMP_DEST_UNREACH) && 1426 (ic->type != ICMP_SOURCE_QUENCH) && 1427 (ic->type != ICMP_TIME_EXCEEDED)) { 1428 *related = 0; 1429 return NF_ACCEPT; 1430 } 1431 1432 /* Now find the contained IP header */ 1433 offset += sizeof(_icmph); 1434 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); 1435 if (cih == NULL) 1436 return NF_ACCEPT; /* The packet looks wrong, ignore */ 1437 1438 /* Special case for errors for IPIP packets */ 1439 ipip = false; 1440 if (cih->protocol == IPPROTO_IPIP) { 1441 if (unlikely(cih->frag_off & htons(IP_OFFSET))) 1442 return NF_ACCEPT; 1443 /* Error for our IPIP must arrive at LOCAL_IN */ 1444 if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL)) 1445 return NF_ACCEPT; 1446 offset += cih->ihl * 4; 1447 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); 1448 if (cih == NULL) 1449 return NF_ACCEPT; /* The packet looks wrong, ignore */ 1450 ipip = true; 1451 } 1452 1453 pd = ip_vs_proto_data_get(ipvs, cih->protocol); 1454 if (!pd) 1455 return NF_ACCEPT; 1456 pp = pd->pp; 1457 1458 /* Is the embedded protocol header present? */ 1459 if (unlikely(cih->frag_off & htons(IP_OFFSET) && 1460 pp->dont_defrag)) 1461 return NF_ACCEPT; 1462 1463 IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset, 1464 "Checking incoming ICMP for"); 1465 1466 offset2 = offset; 1467 ip_vs_fill_iph_skb_icmp(AF_INET, skb, offset, !ipip, &ciph); 1468 offset = ciph.len; 1469 1470 /* The embedded headers contain source and dest in reverse order. 1471 * For IPIP this is error for request, not for reply. 1472 */ 1473 cp = pp->conn_in_get(ipvs, AF_INET, skb, &ciph); 1474 1475 if (!cp) { 1476 int v; 1477 1478 if (!sysctl_schedule_icmp(ipvs)) 1479 return NF_ACCEPT; 1480 1481 if (!ip_vs_try_to_schedule(ipvs, AF_INET, skb, pd, &v, &cp, &ciph)) 1482 return v; 1483 new_cp = true; 1484 } 1485 1486 verdict = NF_DROP; 1487 1488 /* Ensure the checksum is correct */ 1489 if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) { 1490 /* Failed checksum! */ 1491 IP_VS_DBG(1, "Incoming ICMP: failed checksum from %pI4!\n", 1492 &iph->saddr); 1493 goto out; 1494 } 1495 1496 if (ipip) { 1497 __be32 info = ic->un.gateway; 1498 __u8 type = ic->type; 1499 __u8 code = ic->code; 1500 1501 /* Update the MTU */ 1502 if (ic->type == ICMP_DEST_UNREACH && 1503 ic->code == ICMP_FRAG_NEEDED) { 1504 struct ip_vs_dest *dest = cp->dest; 1505 u32 mtu = ntohs(ic->un.frag.mtu); 1506 __be16 frag_off = cih->frag_off; 1507 1508 /* Strip outer IP and ICMP, go to IPIP header */ 1509 if (pskb_pull(skb, ihl + sizeof(_icmph)) == NULL) 1510 goto ignore_ipip; 1511 offset2 -= ihl + sizeof(_icmph); 1512 skb_reset_network_header(skb); 1513 IP_VS_DBG(12, "ICMP for IPIP %pI4->%pI4: mtu=%u\n", 1514 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, mtu); 1515 ipv4_update_pmtu(skb, ipvs->net, 1516 mtu, 0, 0, 0, 0); 1517 /* Client uses PMTUD? */ 1518 if (!(frag_off & htons(IP_DF))) 1519 goto ignore_ipip; 1520 /* Prefer the resulting PMTU */ 1521 if (dest) { 1522 struct ip_vs_dest_dst *dest_dst; 1523 1524 rcu_read_lock(); 1525 dest_dst = rcu_dereference(dest->dest_dst); 1526 if (dest_dst) 1527 mtu = dst_mtu(dest_dst->dst_cache); 1528 rcu_read_unlock(); 1529 } 1530 if (mtu > 68 + sizeof(struct iphdr)) 1531 mtu -= sizeof(struct iphdr); 1532 info = htonl(mtu); 1533 } 1534 /* Strip outer IP, ICMP and IPIP, go to IP header of 1535 * original request. 1536 */ 1537 if (pskb_pull(skb, offset2) == NULL) 1538 goto ignore_ipip; 1539 skb_reset_network_header(skb); 1540 IP_VS_DBG(12, "Sending ICMP for %pI4->%pI4: t=%u, c=%u, i=%u\n", 1541 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1542 type, code, ntohl(info)); 1543 icmp_send(skb, type, code, info); 1544 /* ICMP can be shorter but anyways, account it */ 1545 ip_vs_out_stats(cp, skb); 1546 1547 ignore_ipip: 1548 consume_skb(skb); 1549 verdict = NF_STOLEN; 1550 goto out; 1551 } 1552 1553 /* do the statistics and put it back */ 1554 ip_vs_in_stats(cp, skb); 1555 if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol || 1556 IPPROTO_SCTP == cih->protocol) 1557 offset += 2 * sizeof(__u16); 1558 verdict = ip_vs_icmp_xmit(skb, cp, pp, offset, hooknum, &ciph); 1559 1560 out: 1561 if (likely(!new_cp)) 1562 __ip_vs_conn_put(cp); 1563 else 1564 ip_vs_conn_put(cp); 1565 1566 return verdict; 1567 } 1568 1569 #ifdef CONFIG_IP_VS_IPV6 1570 static int ip_vs_in_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb, 1571 int *related, unsigned int hooknum, 1572 struct ip_vs_iphdr *iph) 1573 { 1574 struct icmp6hdr _icmph, *ic; 1575 struct ip_vs_iphdr ciph = {.flags = 0, .fragoffs = 0};/*Contained IP */ 1576 struct ip_vs_conn *cp; 1577 struct ip_vs_protocol *pp; 1578 struct ip_vs_proto_data *pd; 1579 unsigned int offset, verdict; 1580 bool new_cp = false; 1581 1582 *related = 1; 1583 1584 ic = frag_safe_skb_hp(skb, iph->len, sizeof(_icmph), &_icmph, iph); 1585 if (ic == NULL) 1586 return NF_DROP; 1587 1588 /* 1589 * Work through seeing if this is for us. 1590 * These checks are supposed to be in an order that means easy 1591 * things are checked first to speed up processing.... however 1592 * this means that some packets will manage to get a long way 1593 * down this stack and then be rejected, but that's life. 1594 */ 1595 if (ic->icmp6_type & ICMPV6_INFOMSG_MASK) { 1596 *related = 0; 1597 return NF_ACCEPT; 1598 } 1599 /* Fragment header that is before ICMP header tells us that: 1600 * it's not an error message since they can't be fragmented. 1601 */ 1602 if (iph->flags & IP6_FH_F_FRAG) 1603 return NF_DROP; 1604 1605 IP_VS_DBG(8, "Incoming ICMPv6 (%d,%d) %pI6c->%pI6c\n", 1606 ic->icmp6_type, ntohs(icmpv6_id(ic)), 1607 &iph->saddr, &iph->daddr); 1608 1609 offset = iph->len + sizeof(_icmph); 1610 if (!ip_vs_fill_iph_skb_icmp(AF_INET6, skb, offset, true, &ciph)) 1611 return NF_ACCEPT; 1612 1613 pd = ip_vs_proto_data_get(ipvs, ciph.protocol); 1614 if (!pd) 1615 return NF_ACCEPT; 1616 pp = pd->pp; 1617 1618 /* Cannot handle fragmented embedded protocol */ 1619 if (ciph.fragoffs) 1620 return NF_ACCEPT; 1621 1622 IP_VS_DBG_PKT(11, AF_INET6, pp, skb, offset, 1623 "Checking incoming ICMPv6 for"); 1624 1625 /* The embedded headers contain source and dest in reverse order 1626 * if not from localhost 1627 */ 1628 cp = pp->conn_in_get(ipvs, AF_INET6, skb, &ciph); 1629 1630 if (!cp) { 1631 int v; 1632 1633 if (!sysctl_schedule_icmp(ipvs)) 1634 return NF_ACCEPT; 1635 1636 if (!ip_vs_try_to_schedule(ipvs, AF_INET6, skb, pd, &v, &cp, &ciph)) 1637 return v; 1638 1639 new_cp = true; 1640 } 1641 1642 /* VS/TUN, VS/DR and LOCALNODE just let it go */ 1643 if ((hooknum == NF_INET_LOCAL_OUT) && 1644 (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)) { 1645 verdict = NF_ACCEPT; 1646 goto out; 1647 } 1648 1649 /* do the statistics and put it back */ 1650 ip_vs_in_stats(cp, skb); 1651 1652 /* Need to mangle contained IPv6 header in ICMPv6 packet */ 1653 offset = ciph.len; 1654 if (IPPROTO_TCP == ciph.protocol || IPPROTO_UDP == ciph.protocol || 1655 IPPROTO_SCTP == ciph.protocol) 1656 offset += 2 * sizeof(__u16); /* Also mangle ports */ 1657 1658 verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset, hooknum, &ciph); 1659 1660 out: 1661 if (likely(!new_cp)) 1662 __ip_vs_conn_put(cp); 1663 else 1664 ip_vs_conn_put(cp); 1665 1666 return verdict; 1667 } 1668 #endif 1669 1670 1671 /* 1672 * Check if it's for virtual services, look it up, 1673 * and send it on its way... 1674 */ 1675 static unsigned int 1676 ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int af) 1677 { 1678 struct ip_vs_iphdr iph; 1679 struct ip_vs_protocol *pp; 1680 struct ip_vs_proto_data *pd; 1681 struct ip_vs_conn *cp; 1682 int ret, pkts; 1683 int conn_reuse_mode; 1684 struct sock *sk; 1685 1686 /* Already marked as IPVS request or reply? */ 1687 if (skb->ipvs_property) 1688 return NF_ACCEPT; 1689 1690 /* 1691 * Big tappo: 1692 * - remote client: only PACKET_HOST 1693 * - route: used for struct net when skb->dev is unset 1694 */ 1695 if (unlikely((skb->pkt_type != PACKET_HOST && 1696 hooknum != NF_INET_LOCAL_OUT) || 1697 !skb_dst(skb))) { 1698 ip_vs_fill_iph_skb(af, skb, false, &iph); 1699 IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s" 1700 " ignored in hook %u\n", 1701 skb->pkt_type, iph.protocol, 1702 IP_VS_DBG_ADDR(af, &iph.daddr), hooknum); 1703 return NF_ACCEPT; 1704 } 1705 /* ipvs enabled in this netns ? */ 1706 if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable)) 1707 return NF_ACCEPT; 1708 1709 ip_vs_fill_iph_skb(af, skb, false, &iph); 1710 1711 /* Bad... Do not break raw sockets */ 1712 sk = skb_to_full_sk(skb); 1713 if (unlikely(sk && hooknum == NF_INET_LOCAL_OUT && 1714 af == AF_INET)) { 1715 1716 if (sk->sk_family == PF_INET && inet_sk(sk)->nodefrag) 1717 return NF_ACCEPT; 1718 } 1719 1720 #ifdef CONFIG_IP_VS_IPV6 1721 if (af == AF_INET6) { 1722 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) { 1723 int related; 1724 int verdict = ip_vs_in_icmp_v6(ipvs, skb, &related, 1725 hooknum, &iph); 1726 1727 if (related) 1728 return verdict; 1729 } 1730 } else 1731 #endif 1732 if (unlikely(iph.protocol == IPPROTO_ICMP)) { 1733 int related; 1734 int verdict = ip_vs_in_icmp(ipvs, skb, &related, 1735 hooknum); 1736 1737 if (related) 1738 return verdict; 1739 } 1740 1741 /* Protocol supported? */ 1742 pd = ip_vs_proto_data_get(ipvs, iph.protocol); 1743 if (unlikely(!pd)) { 1744 /* The only way we'll see this packet again is if it's 1745 * encapsulated, so mark it with ipvs_property=1 so we 1746 * skip it if we're ignoring tunneled packets 1747 */ 1748 if (sysctl_ignore_tunneled(ipvs)) 1749 skb->ipvs_property = 1; 1750 1751 return NF_ACCEPT; 1752 } 1753 pp = pd->pp; 1754 /* 1755 * Check if the packet belongs to an existing connection entry 1756 */ 1757 cp = pp->conn_in_get(ipvs, af, skb, &iph); 1758 1759 conn_reuse_mode = sysctl_conn_reuse_mode(ipvs); 1760 if (conn_reuse_mode && !iph.fragoffs && is_new_conn(skb, &iph) && cp) { 1761 bool uses_ct = false, resched = false; 1762 1763 if (unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest && 1764 unlikely(!atomic_read(&cp->dest->weight))) { 1765 resched = true; 1766 uses_ct = ip_vs_conn_uses_conntrack(cp, skb); 1767 } else if (is_new_conn_expected(cp, conn_reuse_mode)) { 1768 uses_ct = ip_vs_conn_uses_conntrack(cp, skb); 1769 if (!atomic_read(&cp->n_control)) { 1770 resched = true; 1771 } else { 1772 /* Do not reschedule controlling connection 1773 * that uses conntrack while it is still 1774 * referenced by controlled connection(s). 1775 */ 1776 resched = !uses_ct; 1777 } 1778 } 1779 1780 if (resched) { 1781 if (!atomic_read(&cp->n_control)) 1782 ip_vs_conn_expire_now(cp); 1783 __ip_vs_conn_put(cp); 1784 if (uses_ct) 1785 return NF_DROP; 1786 cp = NULL; 1787 } 1788 } 1789 1790 if (unlikely(!cp)) { 1791 int v; 1792 1793 if (!ip_vs_try_to_schedule(ipvs, af, skb, pd, &v, &cp, &iph)) 1794 return v; 1795 } 1796 1797 IP_VS_DBG_PKT(11, af, pp, skb, iph.off, "Incoming packet"); 1798 1799 /* Check the server status */ 1800 if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) { 1801 /* the destination server is not available */ 1802 1803 if (sysctl_expire_nodest_conn(ipvs)) { 1804 /* try to expire the connection immediately */ 1805 ip_vs_conn_expire_now(cp); 1806 } 1807 /* don't restart its timer, and silently 1808 drop the packet. */ 1809 __ip_vs_conn_put(cp); 1810 return NF_DROP; 1811 } 1812 1813 ip_vs_in_stats(cp, skb); 1814 ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd); 1815 if (cp->packet_xmit) 1816 ret = cp->packet_xmit(skb, cp, pp, &iph); 1817 /* do not touch skb anymore */ 1818 else { 1819 IP_VS_DBG_RL("warning: packet_xmit is null"); 1820 ret = NF_ACCEPT; 1821 } 1822 1823 /* Increase its packet counter and check if it is needed 1824 * to be synchronized 1825 * 1826 * Sync connection if it is about to close to 1827 * encorage the standby servers to update the connections timeout 1828 * 1829 * For ONE_PKT let ip_vs_sync_conn() do the filter work. 1830 */ 1831 1832 if (cp->flags & IP_VS_CONN_F_ONE_PACKET) 1833 pkts = sysctl_sync_threshold(ipvs); 1834 else 1835 pkts = atomic_add_return(1, &cp->in_pkts); 1836 1837 if (ipvs->sync_state & IP_VS_STATE_MASTER) 1838 ip_vs_sync_conn(ipvs, cp, pkts); 1839 1840 ip_vs_conn_put(cp); 1841 return ret; 1842 } 1843 1844 /* 1845 * AF_INET handler in NF_INET_LOCAL_IN chain 1846 * Schedule and forward packets from remote clients 1847 */ 1848 static unsigned int 1849 ip_vs_remote_request4(void *priv, struct sk_buff *skb, 1850 const struct nf_hook_state *state) 1851 { 1852 return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET); 1853 } 1854 1855 /* 1856 * AF_INET handler in NF_INET_LOCAL_OUT chain 1857 * Schedule and forward packets from local clients 1858 */ 1859 static unsigned int 1860 ip_vs_local_request4(void *priv, struct sk_buff *skb, 1861 const struct nf_hook_state *state) 1862 { 1863 return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET); 1864 } 1865 1866 #ifdef CONFIG_IP_VS_IPV6 1867 1868 /* 1869 * AF_INET6 handler in NF_INET_LOCAL_IN chain 1870 * Schedule and forward packets from remote clients 1871 */ 1872 static unsigned int 1873 ip_vs_remote_request6(void *priv, struct sk_buff *skb, 1874 const struct nf_hook_state *state) 1875 { 1876 return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET6); 1877 } 1878 1879 /* 1880 * AF_INET6 handler in NF_INET_LOCAL_OUT chain 1881 * Schedule and forward packets from local clients 1882 */ 1883 static unsigned int 1884 ip_vs_local_request6(void *priv, struct sk_buff *skb, 1885 const struct nf_hook_state *state) 1886 { 1887 return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET6); 1888 } 1889 1890 #endif 1891 1892 1893 /* 1894 * It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP 1895 * related packets destined for 0.0.0.0/0. 1896 * When fwmark-based virtual service is used, such as transparent 1897 * cache cluster, TCP packets can be marked and routed to ip_vs_in, 1898 * but ICMP destined for 0.0.0.0/0 cannot not be easily marked and 1899 * sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain 1900 * and send them to ip_vs_in_icmp. 1901 */ 1902 static unsigned int 1903 ip_vs_forward_icmp(void *priv, struct sk_buff *skb, 1904 const struct nf_hook_state *state) 1905 { 1906 int r; 1907 struct netns_ipvs *ipvs = net_ipvs(state->net); 1908 1909 if (ip_hdr(skb)->protocol != IPPROTO_ICMP) 1910 return NF_ACCEPT; 1911 1912 /* ipvs enabled in this netns ? */ 1913 if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable)) 1914 return NF_ACCEPT; 1915 1916 return ip_vs_in_icmp(ipvs, skb, &r, state->hook); 1917 } 1918 1919 #ifdef CONFIG_IP_VS_IPV6 1920 static unsigned int 1921 ip_vs_forward_icmp_v6(void *priv, struct sk_buff *skb, 1922 const struct nf_hook_state *state) 1923 { 1924 int r; 1925 struct netns_ipvs *ipvs = net_ipvs(state->net); 1926 struct ip_vs_iphdr iphdr; 1927 1928 ip_vs_fill_iph_skb(AF_INET6, skb, false, &iphdr); 1929 if (iphdr.protocol != IPPROTO_ICMPV6) 1930 return NF_ACCEPT; 1931 1932 /* ipvs enabled in this netns ? */ 1933 if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable)) 1934 return NF_ACCEPT; 1935 1936 return ip_vs_in_icmp_v6(ipvs, skb, &r, state->hook, &iphdr); 1937 } 1938 #endif 1939 1940 1941 static struct nf_hook_ops ip_vs_ops[] __read_mostly = { 1942 /* After packet filtering, change source only for VS/NAT */ 1943 { 1944 .hook = ip_vs_reply4, 1945 .pf = NFPROTO_IPV4, 1946 .hooknum = NF_INET_LOCAL_IN, 1947 .priority = NF_IP_PRI_NAT_SRC - 2, 1948 }, 1949 /* After packet filtering, forward packet through VS/DR, VS/TUN, 1950 * or VS/NAT(change destination), so that filtering rules can be 1951 * applied to IPVS. */ 1952 { 1953 .hook = ip_vs_remote_request4, 1954 .pf = NFPROTO_IPV4, 1955 .hooknum = NF_INET_LOCAL_IN, 1956 .priority = NF_IP_PRI_NAT_SRC - 1, 1957 }, 1958 /* Before ip_vs_in, change source only for VS/NAT */ 1959 { 1960 .hook = ip_vs_local_reply4, 1961 .pf = NFPROTO_IPV4, 1962 .hooknum = NF_INET_LOCAL_OUT, 1963 .priority = NF_IP_PRI_NAT_DST + 1, 1964 }, 1965 /* After mangle, schedule and forward local requests */ 1966 { 1967 .hook = ip_vs_local_request4, 1968 .pf = NFPROTO_IPV4, 1969 .hooknum = NF_INET_LOCAL_OUT, 1970 .priority = NF_IP_PRI_NAT_DST + 2, 1971 }, 1972 /* After packet filtering (but before ip_vs_out_icmp), catch icmp 1973 * destined for 0.0.0.0/0, which is for incoming IPVS connections */ 1974 { 1975 .hook = ip_vs_forward_icmp, 1976 .pf = NFPROTO_IPV4, 1977 .hooknum = NF_INET_FORWARD, 1978 .priority = 99, 1979 }, 1980 /* After packet filtering, change source only for VS/NAT */ 1981 { 1982 .hook = ip_vs_reply4, 1983 .pf = NFPROTO_IPV4, 1984 .hooknum = NF_INET_FORWARD, 1985 .priority = 100, 1986 }, 1987 #ifdef CONFIG_IP_VS_IPV6 1988 /* After packet filtering, change source only for VS/NAT */ 1989 { 1990 .hook = ip_vs_reply6, 1991 .pf = NFPROTO_IPV6, 1992 .hooknum = NF_INET_LOCAL_IN, 1993 .priority = NF_IP6_PRI_NAT_SRC - 2, 1994 }, 1995 /* After packet filtering, forward packet through VS/DR, VS/TUN, 1996 * or VS/NAT(change destination), so that filtering rules can be 1997 * applied to IPVS. */ 1998 { 1999 .hook = ip_vs_remote_request6, 2000 .pf = NFPROTO_IPV6, 2001 .hooknum = NF_INET_LOCAL_IN, 2002 .priority = NF_IP6_PRI_NAT_SRC - 1, 2003 }, 2004 /* Before ip_vs_in, change source only for VS/NAT */ 2005 { 2006 .hook = ip_vs_local_reply6, 2007 .pf = NFPROTO_IPV6, 2008 .hooknum = NF_INET_LOCAL_OUT, 2009 .priority = NF_IP6_PRI_NAT_DST + 1, 2010 }, 2011 /* After mangle, schedule and forward local requests */ 2012 { 2013 .hook = ip_vs_local_request6, 2014 .pf = NFPROTO_IPV6, 2015 .hooknum = NF_INET_LOCAL_OUT, 2016 .priority = NF_IP6_PRI_NAT_DST + 2, 2017 }, 2018 /* After packet filtering (but before ip_vs_out_icmp), catch icmp 2019 * destined for 0.0.0.0/0, which is for incoming IPVS connections */ 2020 { 2021 .hook = ip_vs_forward_icmp_v6, 2022 .pf = NFPROTO_IPV6, 2023 .hooknum = NF_INET_FORWARD, 2024 .priority = 99, 2025 }, 2026 /* After packet filtering, change source only for VS/NAT */ 2027 { 2028 .hook = ip_vs_reply6, 2029 .pf = NFPROTO_IPV6, 2030 .hooknum = NF_INET_FORWARD, 2031 .priority = 100, 2032 }, 2033 #endif 2034 }; 2035 /* 2036 * Initialize IP Virtual Server netns mem. 2037 */ 2038 static int __net_init __ip_vs_init(struct net *net) 2039 { 2040 struct netns_ipvs *ipvs; 2041 2042 ipvs = net_generic(net, ip_vs_net_id); 2043 if (ipvs == NULL) 2044 return -ENOMEM; 2045 2046 /* Hold the beast until a service is registerd */ 2047 ipvs->enable = 0; 2048 ipvs->net = net; 2049 /* Counters used for creating unique names */ 2050 ipvs->gen = atomic_read(&ipvs_netns_cnt); 2051 atomic_inc(&ipvs_netns_cnt); 2052 net->ipvs = ipvs; 2053 2054 if (ip_vs_estimator_net_init(ipvs) < 0) 2055 goto estimator_fail; 2056 2057 if (ip_vs_control_net_init(ipvs) < 0) 2058 goto control_fail; 2059 2060 if (ip_vs_protocol_net_init(ipvs) < 0) 2061 goto protocol_fail; 2062 2063 if (ip_vs_app_net_init(ipvs) < 0) 2064 goto app_fail; 2065 2066 if (ip_vs_conn_net_init(ipvs) < 0) 2067 goto conn_fail; 2068 2069 if (ip_vs_sync_net_init(ipvs) < 0) 2070 goto sync_fail; 2071 2072 printk(KERN_INFO "IPVS: Creating netns size=%zu id=%d\n", 2073 sizeof(struct netns_ipvs), ipvs->gen); 2074 return 0; 2075 /* 2076 * Error handling 2077 */ 2078 2079 sync_fail: 2080 ip_vs_conn_net_cleanup(ipvs); 2081 conn_fail: 2082 ip_vs_app_net_cleanup(ipvs); 2083 app_fail: 2084 ip_vs_protocol_net_cleanup(ipvs); 2085 protocol_fail: 2086 ip_vs_control_net_cleanup(ipvs); 2087 control_fail: 2088 ip_vs_estimator_net_cleanup(ipvs); 2089 estimator_fail: 2090 net->ipvs = NULL; 2091 return -ENOMEM; 2092 } 2093 2094 static void __net_exit __ip_vs_cleanup(struct net *net) 2095 { 2096 struct netns_ipvs *ipvs = net_ipvs(net); 2097 2098 ip_vs_service_net_cleanup(ipvs); /* ip_vs_flush() with locks */ 2099 ip_vs_conn_net_cleanup(ipvs); 2100 ip_vs_app_net_cleanup(ipvs); 2101 ip_vs_protocol_net_cleanup(ipvs); 2102 ip_vs_control_net_cleanup(ipvs); 2103 ip_vs_estimator_net_cleanup(ipvs); 2104 IP_VS_DBG(2, "ipvs netns %d released\n", ipvs->gen); 2105 net->ipvs = NULL; 2106 } 2107 2108 static void __net_exit __ip_vs_dev_cleanup(struct net *net) 2109 { 2110 struct netns_ipvs *ipvs = net_ipvs(net); 2111 EnterFunction(2); 2112 ipvs->enable = 0; /* Disable packet reception */ 2113 smp_wmb(); 2114 ip_vs_sync_net_cleanup(ipvs); 2115 LeaveFunction(2); 2116 } 2117 2118 static struct pernet_operations ipvs_core_ops = { 2119 .init = __ip_vs_init, 2120 .exit = __ip_vs_cleanup, 2121 .id = &ip_vs_net_id, 2122 .size = sizeof(struct netns_ipvs), 2123 }; 2124 2125 static struct pernet_operations ipvs_core_dev_ops = { 2126 .exit = __ip_vs_dev_cleanup, 2127 }; 2128 2129 /* 2130 * Initialize IP Virtual Server 2131 */ 2132 static int __init ip_vs_init(void) 2133 { 2134 int ret; 2135 2136 ret = ip_vs_control_init(); 2137 if (ret < 0) { 2138 pr_err("can't setup control.\n"); 2139 goto exit; 2140 } 2141 2142 ip_vs_protocol_init(); 2143 2144 ret = ip_vs_conn_init(); 2145 if (ret < 0) { 2146 pr_err("can't setup connection table.\n"); 2147 goto cleanup_protocol; 2148 } 2149 2150 ret = register_pernet_subsys(&ipvs_core_ops); /* Alloc ip_vs struct */ 2151 if (ret < 0) 2152 goto cleanup_conn; 2153 2154 ret = register_pernet_device(&ipvs_core_dev_ops); 2155 if (ret < 0) 2156 goto cleanup_sub; 2157 2158 ret = nf_register_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); 2159 if (ret < 0) { 2160 pr_err("can't register hooks.\n"); 2161 goto cleanup_dev; 2162 } 2163 2164 ret = ip_vs_register_nl_ioctl(); 2165 if (ret < 0) { 2166 pr_err("can't register netlink/ioctl.\n"); 2167 goto cleanup_hooks; 2168 } 2169 2170 pr_info("ipvs loaded.\n"); 2171 2172 return ret; 2173 2174 cleanup_hooks: 2175 nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); 2176 cleanup_dev: 2177 unregister_pernet_device(&ipvs_core_dev_ops); 2178 cleanup_sub: 2179 unregister_pernet_subsys(&ipvs_core_ops); 2180 cleanup_conn: 2181 ip_vs_conn_cleanup(); 2182 cleanup_protocol: 2183 ip_vs_protocol_cleanup(); 2184 ip_vs_control_cleanup(); 2185 exit: 2186 return ret; 2187 } 2188 2189 static void __exit ip_vs_cleanup(void) 2190 { 2191 ip_vs_unregister_nl_ioctl(); 2192 nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); 2193 unregister_pernet_device(&ipvs_core_dev_ops); 2194 unregister_pernet_subsys(&ipvs_core_ops); /* free ip_vs struct */ 2195 ip_vs_conn_cleanup(); 2196 ip_vs_protocol_cleanup(); 2197 ip_vs_control_cleanup(); 2198 pr_info("ipvs unloaded.\n"); 2199 } 2200 2201 module_init(ip_vs_init); 2202 module_exit(ip_vs_cleanup); 2203 MODULE_LICENSE("GPL"); 2204
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