Pileus Git - ~andy/linux/blob - net/netfilter/ipvs/ip_vs_core.c

   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_%d", 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 = net_ipvs(skb_net(skb));
 116
 117         if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
 118                 struct ip_vs_cpu_stats *s;
 119
 120                 s = this_cpu_ptr(dest->stats.cpustats);
 121                 s->ustats.inpkts++;
 122                 u64_stats_update_begin(&s->syncp);
 123                 s->ustats.inbytes += skb->len;
 124                 u64_stats_update_end(&s->syncp);
 125
 126                 s = this_cpu_ptr(dest->svc->stats.cpustats);
 127                 s->ustats.inpkts++;
 128                 u64_stats_update_begin(&s->syncp);
 129                 s->ustats.inbytes += skb->len;
 130                 u64_stats_update_end(&s->syncp);
 131
 132                 s = this_cpu_ptr(ipvs->tot_stats.cpustats);
 133                 s->ustats.inpkts++;
 134                 u64_stats_update_begin(&s->syncp);
 135                 s->ustats.inbytes += skb->len;
 136                 u64_stats_update_end(&s->syncp);
 137         }
 138 }
 139
 140
 141 static inline void
 142 ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
 143 {
 144         struct ip_vs_dest *dest = cp->dest;
 145         struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
 146
 147         if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
 148                 struct ip_vs_cpu_stats *s;
 149
 150                 s = this_cpu_ptr(dest->stats.cpustats);
 151                 s->ustats.outpkts++;
 152                 u64_stats_update_begin(&s->syncp);
 153                 s->ustats.outbytes += skb->len;
 154                 u64_stats_update_end(&s->syncp);
 155
 156                 s = this_cpu_ptr(dest->svc->stats.cpustats);
 157                 s->ustats.outpkts++;
 158                 u64_stats_update_begin(&s->syncp);
 159                 s->ustats.outbytes += skb->len;
 160                 u64_stats_update_end(&s->syncp);
 161
 162                 s = this_cpu_ptr(ipvs->tot_stats.cpustats);
 163                 s->ustats.outpkts++;
 164                 u64_stats_update_begin(&s->syncp);
 165                 s->ustats.outbytes += skb->len;
 166                 u64_stats_update_end(&s->syncp);
 167         }
 168 }
 169
 170
 171 static inline void
 172 ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
 173 {
 174         struct netns_ipvs *ipvs = net_ipvs(svc->net);
 175         struct ip_vs_cpu_stats *s;
 176
 177         s = this_cpu_ptr(cp->dest->stats.cpustats);
 178         s->ustats.conns++;
 179
 180         s = this_cpu_ptr(svc->stats.cpustats);
 181         s->ustats.conns++;
 182
 183         s = this_cpu_ptr(ipvs->tot_stats.cpustats);
 184         s->ustats.conns++;
 185 }
 186
 187
 188 static inline void
 189 ip_vs_set_state(struct ip_vs_conn *cp, int direction,
 190                 const struct sk_buff *skb,
 191                 struct ip_vs_proto_data *pd)
 192 {
 193         if (likely(pd->pp->state_transition))
 194                 pd->pp->state_transition(cp, direction, skb, pd);
 195 }
 196
 197 static inline int
 198 ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc,
 199                               struct sk_buff *skb, int protocol,
 200                               const union nf_inet_addr *caddr, __be16 cport,
 201                               const union nf_inet_addr *vaddr, __be16 vport,
 202                               struct ip_vs_conn_param *p)
 203 {
 204         ip_vs_conn_fill_param(svc->net, svc->af, protocol, caddr, cport, vaddr,
 205                               vport, p);
 206         p->pe = svc->pe;
 207         if (p->pe && p->pe->fill_param)
 208                 return p->pe->fill_param(p, skb);
 209
 210         return 0;
 211 }
 212
 213 /*
 214  *  IPVS persistent scheduling function
 215  *  It creates a connection entry according to its template if exists,
 216  *  or selects a server and creates a connection entry plus a template.
 217  *  Locking: we are svc user (svc->refcnt), so we hold all dests too
 218  *  Protocols supported: TCP, UDP
 219  */
 220 static struct ip_vs_conn *
 221 ip_vs_sched_persist(struct ip_vs_service *svc,
 222                     struct sk_buff *skb, __be16 src_port, __be16 dst_port,
 223                     int *ignored, struct ip_vs_iphdr *iph)
 224 {
 225         struct ip_vs_conn *cp = NULL;
 226         struct ip_vs_dest *dest;
 227         struct ip_vs_conn *ct;
 228         __be16 dport = 0;               /* destination port to forward */
 229         unsigned int flags;
 230         struct ip_vs_conn_param param;
 231         const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) };
 232         union nf_inet_addr snet;        /* source network of the client,
 233                                            after masking */
 234
 235         /* Mask saddr with the netmask to adjust template granularity */
 236 #ifdef CONFIG_IP_VS_IPV6
 237         if (svc->af == AF_INET6)
 238                 ipv6_addr_prefix(&snet.in6, &iph->saddr.in6, svc->netmask);
 239         else
 240 #endif
 241                 snet.ip = iph->saddr.ip & svc->netmask;
 242
 243         IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
 244                       "mnet %s\n",
 245                       IP_VS_DBG_ADDR(svc->af, &iph->saddr), ntohs(src_port),
 246                       IP_VS_DBG_ADDR(svc->af, &iph->daddr), ntohs(dst_port),
 247                       IP_VS_DBG_ADDR(svc->af, &snet));
 248
 249         /*
 250          * As far as we know, FTP is a very complicated network protocol, and
 251          * it uses control connection and data connections. For active FTP,
 252          * FTP server initialize data connection to the client, its source port
 253          * is often 20. For passive FTP, FTP server tells the clients the port
 254          * that it passively listens to,  and the client issues the data
 255          * connection. In the tunneling or direct routing mode, the load
 256          * balancer is on the client-to-server half of connection, the port
 257          * number is unknown to the load balancer. So, a conn template like
 258          * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
 259          * service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
 260          * is created for other persistent services.
 261          */
 262         {
 263                 int protocol = iph->protocol;
 264                 const union nf_inet_addr *vaddr = &iph->daddr;
 265                 __be16 vport = 0;
 266
 267                 if (dst_port == svc->port) {
 268                         /* non-FTP template:
 269                          * <protocol, caddr, 0, vaddr, vport, daddr, dport>
 270                          * FTP template:
 271                          * <protocol, caddr, 0, vaddr, 0, daddr, 0>
 272                          */
 273                         if (svc->port != FTPPORT)
 274                                 vport = dst_port;
 275                 } else {
 276                         /* Note: persistent fwmark-based services and
 277                          * persistent port zero service are handled here.
 278                          * fwmark template:
 279                          * <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
 280                          * port zero template:
 281                          * <protocol,caddr,0,vaddr,0,daddr,0>
 282                          */
 283                         if (svc->fwmark) {
 284                                 protocol = IPPROTO_IP;
 285                                 vaddr = &fwmark;
 286                         }
 287                 }
 288                 /* return *ignored = -1 so NF_DROP can be used */
 289                 if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
 290                                                   vaddr, vport, &param) < 0) {
 291                         *ignored = -1;
 292                         return NULL;
 293                 }
 294         }
 295
 296         /* Check if a template already exists */
 297         ct = ip_vs_ct_in_get(&param);
 298         if (!ct || !ip_vs_check_template(ct)) {
 299                 /*
 300                  * No template found or the dest of the connection
 301                  * template is not available.
 302                  * return *ignored=0 i.e. ICMP and NF_DROP
 303                  */
 304                 rcu_read_lock();
 305                 dest = svc->scheduler->schedule(svc, skb);
 306                 if (!dest) {
 307                         rcu_read_unlock();
 308                         IP_VS_DBG(1, "p-schedule: no dest found.\n");
 309                         kfree(param.pe_data);
 310                         *ignored = 0;
 311                         return NULL;
 312                 }
 313
 314                 if (dst_port == svc->port && svc->port != FTPPORT)
 315                         dport = dest->port;
 316
 317                 /* Create a template
 318                  * This adds param.pe_data to the template,
 319                  * and thus param.pe_data will be destroyed
 320                  * when the template expires */
 321                 ct = ip_vs_conn_new(&param, &dest->addr, dport,
 322                                     IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
 323                 rcu_read_unlock();
 324                 if (ct == NULL) {
 325                         kfree(param.pe_data);
 326                         *ignored = -1;
 327                         return NULL;
 328                 }
 329
 330                 ct->timeout = svc->timeout;
 331         } else {
 332                 /* set destination with the found template */
 333                 dest = ct->dest;
 334                 kfree(param.pe_data);
 335         }
 336
 337         dport = dst_port;
 338         if (dport == svc->port && dest->port)
 339                 dport = dest->port;
 340
 341         flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
 342                  && iph->protocol == IPPROTO_UDP) ?
 343                 IP_VS_CONN_F_ONE_PACKET : 0;
 344
 345         /*
 346          *    Create a new connection according to the template
 347          */
 348         ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol, &iph->saddr,
 349                               src_port, &iph->daddr, dst_port, &param);
 350
 351         cp = ip_vs_conn_new(&param, &dest->addr, dport, flags, dest, skb->mark);
 352         if (cp == NULL) {
 353                 ip_vs_conn_put(ct);
 354                 *ignored = -1;
 355                 return NULL;
 356         }
 357
 358         /*
 359          *    Add its control
 360          */
 361         ip_vs_control_add(cp, ct);
 362         ip_vs_conn_put(ct);
 363
 364         ip_vs_conn_stats(cp, svc);
 365         return cp;
 366 }
 367
 368
 369 /*
 370  *  IPVS main scheduling function
 371  *  It selects a server according to the virtual service, and
 372  *  creates a connection entry.
 373  *  Protocols supported: TCP, UDP
 374  *
 375  *  Usage of *ignored
 376  *
 377  * 1 :   protocol tried to schedule (eg. on SYN), found svc but the
 378  *       svc/scheduler decides that this packet should be accepted with
 379  *       NF_ACCEPT because it must not be scheduled.
 380  *
 381  * 0 :   scheduler can not find destination, so try bypass or
 382  *       return ICMP and then NF_DROP (ip_vs_leave).
 383  *
 384  * -1 :  scheduler tried to schedule but fatal error occurred, eg.
 385  *       ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
 386  *       failure such as missing Call-ID, ENOMEM on skb_linearize
 387  *       or pe_data. In this case we should return NF_DROP without
 388  *       any attempts to send ICMP with ip_vs_leave.
 389  */
 390 struct ip_vs_conn *
 391 ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
 392                struct ip_vs_proto_data *pd, int *ignored,
 393                struct ip_vs_iphdr *iph)
 394 {
 395         struct ip_vs_protocol *pp = pd->pp;
 396         struct ip_vs_conn *cp = NULL;
 397         struct ip_vs_dest *dest;
 398         __be16 _ports[2], *pptr;
 399         unsigned int flags;
 400
 401         *ignored = 1;
 402         /*
 403          * IPv6 frags, only the first hit here.
 404          */
 405         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
 406         if (pptr == NULL)
 407                 return NULL;
 408
 409         /*
 410          * FTPDATA needs this check when using local real server.
 411          * Never schedule Active FTPDATA connections from real server.
 412          * For LVS-NAT they must be already created. For other methods
 413          * with persistence the connection is created on SYN+ACK.
 414          */
 415         if (pptr[0] == FTPDATA) {
 416                 IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
 417                               "Not scheduling FTPDATA");
 418                 return NULL;
 419         }
 420
 421         /*
 422          *    Do not schedule replies from local real server.
 423          */
 424         if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
 425             (cp = pp->conn_in_get(svc->af, skb, iph, 1))) {
 426                 IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
 427                               "Not scheduling reply for existing connection");
 428                 __ip_vs_conn_put(cp);
 429                 return NULL;
 430         }
 431
 432         /*
 433          *    Persistent service
 434          */
 435         if (svc->flags & IP_VS_SVC_F_PERSISTENT)
 436                 return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored,
 437                                            iph);
 438
 439         *ignored = 0;
 440
 441         /*
 442          *    Non-persistent service
 443          */
 444         if (!svc->fwmark && pptr[1] != svc->port) {
 445                 if (!svc->port)
 446                         pr_err("Schedule: port zero only supported "
 447                                "in persistent services, "
 448                                "check your ipvs configuration\n");
 449                 return NULL;
 450         }
 451
 452         rcu_read_lock();
 453         dest = svc->scheduler->schedule(svc, skb);
 454         if (dest == NULL) {
 455                 rcu_read_unlock();
 456                 IP_VS_DBG(1, "Schedule: no dest found.\n");
 457                 return NULL;
 458         }
 459
 460         flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
 461                  && iph->protocol == IPPROTO_UDP) ?
 462                 IP_VS_CONN_F_ONE_PACKET : 0;
 463
 464         /*
 465          *    Create a connection entry.
 466          */
 467         {
 468                 struct ip_vs_conn_param p;
 469
 470                 ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol,
 471                                       &iph->saddr, pptr[0], &iph->daddr,
 472                                       pptr[1], &p);
 473                 cp = ip_vs_conn_new(&p, &dest->addr,
 474                                     dest->port ? dest->port : pptr[1],
 475                                     flags, dest, skb->mark);
 476                 rcu_read_unlock();
 477                 if (!cp) {
 478                         *ignored = -1;
 479                         return NULL;
 480                 }
 481         }
 482
 483         IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
 484                       "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
 485                       ip_vs_fwd_tag(cp),
 486                       IP_VS_DBG_ADDR(svc->af, &cp->caddr), ntohs(cp->cport),
 487                       IP_VS_DBG_ADDR(svc->af, &cp->vaddr), ntohs(cp->vport),
 488                       IP_VS_DBG_ADDR(svc->af, &cp->daddr), ntohs(cp->dport),
 489                       cp->flags, atomic_read(&cp->refcnt));
 490
 491         ip_vs_conn_stats(cp, svc);
 492         return cp;
 493 }
 494
 495
 496 /*
 497  *  Pass or drop the packet.
 498  *  Called by ip_vs_in, when the virtual service is available but
 499  *  no destination is available for a new connection.
 500  */
 501 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
 502                 struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph)
 503 {
 504         __be16 _ports[2], *pptr;
 505 #ifdef CONFIG_SYSCTL
 506         struct net *net;
 507         struct netns_ipvs *ipvs;
 508         int unicast;
 509 #endif
 510
 511         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
 512         if (pptr == NULL) {
 513                 ip_vs_service_put(svc);
 514                 return NF_DROP;
 515         }
 516
 517 #ifdef CONFIG_SYSCTL
 518         net = skb_net(skb);
 519
 520 #ifdef CONFIG_IP_VS_IPV6
 521         if (svc->af == AF_INET6)
 522                 unicast = ipv6_addr_type(&iph->daddr.in6) & IPV6_ADDR_UNICAST;
 523         else
 524 #endif
 525                 unicast = (inet_addr_type(net, iph->daddr.ip) == RTN_UNICAST);
 526
 527         /* if it is fwmark-based service, the cache_bypass sysctl is up
 528            and the destination is a non-local unicast, then create
 529            a cache_bypass connection entry */
 530         ipvs = net_ipvs(net);
 531         if (ipvs->sysctl_cache_bypass && svc->fwmark && unicast) {
 532                 int ret;
 533                 struct ip_vs_conn *cp;
 534                 unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
 535                                       iph->protocol == IPPROTO_UDP) ?
 536                                       IP_VS_CONN_F_ONE_PACKET : 0;
 537                 union nf_inet_addr daddr =  { .all = { 0, 0, 0, 0 } };
 538
 539                 ip_vs_service_put(svc);
 540
 541                 /* create a new connection entry */
 542                 IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
 543                 {
 544                         struct ip_vs_conn_param p;
 545                         ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol,
 546                                               &iph->saddr, pptr[0],
 547                                               &iph->daddr, pptr[1], &p);
 548                         cp = ip_vs_conn_new(&p, &daddr, 0,
 549                                             IP_VS_CONN_F_BYPASS | flags,
 550                                             NULL, skb->mark);
 551                         if (!cp)
 552                                 return NF_DROP;
 553                 }
 554
 555                 /* statistics */
 556                 ip_vs_in_stats(cp, skb);
 557
 558                 /* set state */
 559                 ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
 560
 561                 /* transmit the first SYN packet */
 562                 ret = cp->packet_xmit(skb, cp, pd->pp, iph);
 563                 /* do not touch skb anymore */
 564
 565                 atomic_inc(&cp->in_pkts);
 566                 ip_vs_conn_put(cp);
 567                 return ret;
 568         }
 569 #endif
 570
 571         /*
 572          * When the virtual ftp service is presented, packets destined
 573          * for other services on the VIP may get here (except services
 574          * listed in the ipvs table), pass the packets, because it is
 575          * not ipvs job to decide to drop the packets.
 576          */
 577         if ((svc->port == FTPPORT) && (pptr[1] != FTPPORT)) {
 578                 ip_vs_service_put(svc);
 579                 return NF_ACCEPT;
 580         }
 581
 582         ip_vs_service_put(svc);
 583
 584         /*
 585          * Notify the client that the destination is unreachable, and
 586          * release the socket buffer.
 587          * Since it is in IP layer, the TCP socket is not actually
 588          * created, the TCP RST packet cannot be sent, instead that
 589          * ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
 590          */
 591 #ifdef CONFIG_IP_VS_IPV6
 592         if (svc->af == AF_INET6) {
 593                 if (!skb->dev) {
 594                         struct net *net = dev_net(skb_dst(skb)->dev);
 595
 596                         skb->dev = net->loopback_dev;
 597                 }
 598                 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 599         } else
 600 #endif
 601                 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 602
 603         return NF_DROP;
 604 }
 605
 606 #ifdef CONFIG_SYSCTL
 607
 608 static int sysctl_snat_reroute(struct sk_buff *skb)
 609 {
 610         struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
 611         return ipvs->sysctl_snat_reroute;
 612 }
 613
 614 static int sysctl_nat_icmp_send(struct net *net)
 615 {
 616         struct netns_ipvs *ipvs = net_ipvs(net);
 617         return ipvs->sysctl_nat_icmp_send;
 618 }
 619
 620 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
 621 {
 622         return ipvs->sysctl_expire_nodest_conn;
 623 }
 624
 625 #else
 626
 627 static int sysctl_snat_reroute(struct sk_buff *skb) { return 0; }
 628 static int sysctl_nat_icmp_send(struct net *net) { return 0; }
 629 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) { return 0; }
 630
 631 #endif
 632
 633 __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset)
 634 {
 635         return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
 636 }
 637
 638 static inline enum ip_defrag_users ip_vs_defrag_user(unsigned int hooknum)
 639 {
 640         if (NF_INET_LOCAL_IN == hooknum)
 641                 return IP_DEFRAG_VS_IN;
 642         if (NF_INET_FORWARD == hooknum)
 643                 return IP_DEFRAG_VS_FWD;
 644         return IP_DEFRAG_VS_OUT;
 645 }
 646
 647 static inline int ip_vs_gather_frags(struct sk_buff *skb, u_int32_t user)
 648 {
 649         int err = ip_defrag(skb, user);
 650
 651         if (!err)
 652                 ip_send_check(ip_hdr(skb));
 653
 654         return err;
 655 }
 656
 657 static int ip_vs_route_me_harder(int af, struct sk_buff *skb)
 658 {
 659 #ifdef CONFIG_IP_VS_IPV6
 660         if (af == AF_INET6) {
 661                 if (sysctl_snat_reroute(skb) && ip6_route_me_harder(skb) != 0)
 662                         return 1;
 663         } else
 664 #endif
 665                 if ((sysctl_snat_reroute(skb) ||
 666                      skb_rtable(skb)->rt_flags & RTCF_LOCAL) &&
 667                     ip_route_me_harder(skb, RTN_LOCAL) != 0)
 668                         return 1;
 669
 670         return 0;
 671 }
 672
 673 /*
 674  * Packet has been made sufficiently writable in caller
 675  * - inout: 1=in->out, 0=out->in
 676  */
 677 void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
 678                     struct ip_vs_conn *cp, int inout)
 679 {
 680         struct iphdr *iph        = ip_hdr(skb);
 681         unsigned int icmp_offset = iph->ihl*4;
 682         struct icmphdr *icmph    = (struct icmphdr *)(skb_network_header(skb) +
 683                                                       icmp_offset);
 684         struct iphdr *ciph       = (struct iphdr *)(icmph + 1);
 685
 686         if (inout) {
 687                 iph->saddr = cp->vaddr.ip;
 688                 ip_send_check(iph);
 689                 ciph->daddr = cp->vaddr.ip;
 690                 ip_send_check(ciph);
 691         } else {
 692                 iph->daddr = cp->daddr.ip;
 693                 ip_send_check(iph);
 694                 ciph->saddr = cp->daddr.ip;
 695                 ip_send_check(ciph);
 696         }
 697
 698         /* the TCP/UDP/SCTP port */
 699         if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol ||
 700             IPPROTO_SCTP == ciph->protocol) {
 701                 __be16 *ports = (void *)ciph + ciph->ihl*4;
 702
 703                 if (inout)
 704                         ports[1] = cp->vport;
 705                 else
 706                         ports[0] = cp->dport;
 707         }
 708
 709         /* And finally the ICMP checksum */
 710         icmph->checksum = 0;
 711         icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset);
 712         skb->ip_summed = CHECKSUM_UNNECESSARY;
 713
 714         if (inout)
 715                 IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph,
 716                         "Forwarding altered outgoing ICMP");
 717         else
 718                 IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph,
 719                         "Forwarding altered incoming ICMP");
 720 }
 721
 722 #ifdef CONFIG_IP_VS_IPV6
 723 void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
 724                     struct ip_vs_conn *cp, int inout)
 725 {
 726         struct ipv6hdr *iph      = ipv6_hdr(skb);
 727         unsigned int icmp_offset = 0;
 728         unsigned int offs        = 0; /* header offset*/
 729         int protocol;
 730         struct icmp6hdr *icmph;
 731         struct ipv6hdr *ciph;
 732         unsigned short fragoffs;
 733
 734         ipv6_find_hdr(skb, &icmp_offset, IPPROTO_ICMPV6, &fragoffs, NULL);
 735         icmph = (struct icmp6hdr *)(skb_network_header(skb) + icmp_offset);
 736         offs = icmp_offset + sizeof(struct icmp6hdr);
 737         ciph = (struct ipv6hdr *)(skb_network_header(skb) + offs);
 738
 739         protocol = ipv6_find_hdr(skb, &offs, -1, &fragoffs, NULL);
 740
 741         if (inout) {
 742                 iph->saddr = cp->vaddr.in6;
 743                 ciph->daddr = cp->vaddr.in6;
 744         } else {
 745                 iph->daddr = cp->daddr.in6;
 746                 ciph->saddr = cp->daddr.in6;
 747         }
 748
 749         /* the TCP/UDP/SCTP port */
 750         if (!fragoffs && (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol ||
 751                           IPPROTO_SCTP == protocol)) {
 752                 __be16 *ports = (void *)(skb_network_header(skb) + offs);
 753
 754                 IP_VS_DBG(11, "%s() changed port %d to %d\n", __func__,
 755                               ntohs(inout ? ports[1] : ports[0]),
 756                               ntohs(inout ? cp->vport : cp->dport));
 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->icmp6_cksum = ~csum_ipv6_magic(&iph->saddr, &iph->daddr,
 765                                               skb->len - icmp_offset,
 766                                               IPPROTO_ICMPV6, 0);
 767         skb->csum_start = skb_network_header(skb) - skb->head + icmp_offset;
 768         skb->csum_offset = offsetof(struct icmp6hdr, icmp6_cksum);
 769         skb->ip_summed = CHECKSUM_PARTIAL;
 770
 771         if (inout)
 772                 IP_VS_DBG_PKT(11, AF_INET6, pp, skb,
 773                               (void *)ciph - (void *)iph,
 774                               "Forwarding altered outgoing ICMPv6");
 775         else
 776                 IP_VS_DBG_PKT(11, AF_INET6, pp, skb,
 777                               (void *)ciph - (void *)iph,
 778                               "Forwarding altered incoming ICMPv6");
 779 }
 780 #endif
 781
 782 /* Handle relevant response ICMP messages - forward to the right
 783  * destination host.
 784  */
 785 static int handle_response_icmp(int af, struct sk_buff *skb,
 786                                 union nf_inet_addr *snet,
 787                                 __u8 protocol, struct ip_vs_conn *cp,
 788                                 struct ip_vs_protocol *pp,
 789                                 unsigned int offset, unsigned int ihl)
 790 {
 791         unsigned int verdict = NF_DROP;
 792
 793         if (IP_VS_FWD_METHOD(cp) != 0) {
 794                 pr_err("shouldn't reach here, because the box is on the "
 795                        "half connection in the tun/dr module.\n");
 796         }
 797
 798         /* Ensure the checksum is correct */
 799         if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
 800                 /* Failed checksum! */
 801                 IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n",
 802                               IP_VS_DBG_ADDR(af, snet));
 803                 goto out;
 804         }
 805
 806         if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol ||
 807             IPPROTO_SCTP == protocol)
 808                 offset += 2 * sizeof(__u16);
 809         if (!skb_make_writable(skb, offset))
 810                 goto out;
 811
 812 #ifdef CONFIG_IP_VS_IPV6
 813         if (af == AF_INET6)
 814                 ip_vs_nat_icmp_v6(skb, pp, cp, 1);
 815         else
 816 #endif
 817                 ip_vs_nat_icmp(skb, pp, cp, 1);
 818
 819         if (ip_vs_route_me_harder(af, skb))
 820                 goto out;
 821
 822         /* do the statistics and put it back */
 823         ip_vs_out_stats(cp, skb);
 824
 825         skb->ipvs_property = 1;
 826         if (!(cp->flags & IP_VS_CONN_F_NFCT))
 827                 ip_vs_notrack(skb);
 828         else
 829                 ip_vs_update_conntrack(skb, cp, 0);
 830         verdict = NF_ACCEPT;
 831
 832 out:
 833         __ip_vs_conn_put(cp);
 834
 835         return verdict;
 836 }
 837
 838 /*
 839  *      Handle ICMP messages in the inside-to-outside direction (outgoing).
 840  *      Find any that might be relevant, check against existing connections.
 841  *      Currently handles error types - unreachable, quench, ttl exceeded.
 842  */
 843 static int ip_vs_out_icmp(struct sk_buff *skb, int *related,
 844                           unsigned int hooknum)
 845 {
 846         struct iphdr *iph;
 847         struct icmphdr  _icmph, *ic;
 848         struct iphdr    _ciph, *cih;    /* The ip header contained within the ICMP */
 849         struct ip_vs_iphdr ciph;
 850         struct ip_vs_conn *cp;
 851         struct ip_vs_protocol *pp;
 852         unsigned int offset, ihl;
 853         union nf_inet_addr snet;
 854
 855         *related = 1;
 856
 857         /* reassemble IP fragments */
 858         if (ip_is_fragment(ip_hdr(skb))) {
 859                 if (ip_vs_gather_frags(skb, ip_vs_defrag_user(hooknum)))
 860                         return NF_STOLEN;
 861         }
 862
 863         iph = ip_hdr(skb);
 864         offset = ihl = iph->ihl * 4;
 865         ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
 866         if (ic == NULL)
 867                 return NF_DROP;
 868
 869         IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %pI4->%pI4\n",
 870                   ic->type, ntohs(icmp_id(ic)),
 871                   &iph->saddr, &iph->daddr);
 872
 873         /*
 874          * Work through seeing if this is for us.
 875          * These checks are supposed to be in an order that means easy
 876          * things are checked first to speed up processing.... however
 877          * this means that some packets will manage to get a long way
 878          * down this stack and then be rejected, but that's life.
 879          */
 880         if ((ic->type != ICMP_DEST_UNREACH) &&
 881             (ic->type != ICMP_SOURCE_QUENCH) &&
 882             (ic->type != ICMP_TIME_EXCEEDED)) {
 883                 *related = 0;
 884                 return NF_ACCEPT;
 885         }
 886
 887         /* Now find the contained IP header */
 888         offset += sizeof(_icmph);
 889         cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
 890         if (cih == NULL)
 891                 return NF_ACCEPT; /* The packet looks wrong, ignore */
 892
 893         pp = ip_vs_proto_get(cih->protocol);
 894         if (!pp)
 895                 return NF_ACCEPT;
 896
 897         /* Is the embedded protocol header present? */
 898         if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
 899                      pp->dont_defrag))
 900                 return NF_ACCEPT;
 901
 902         IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset,
 903                       "Checking outgoing ICMP for");
 904
 905         ip_vs_fill_ip4hdr(cih, &ciph);
 906         ciph.len += offset;
 907         /* The embedded headers contain source and dest in reverse order */
 908         cp = pp->conn_out_get(AF_INET, skb, &ciph, 1);
 909         if (!cp)
 910                 return NF_ACCEPT;
 911
 912         snet.ip = iph->saddr;
 913         return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp,
 914                                     pp, ciph.len, ihl);
 915 }
 916
 917 #ifdef CONFIG_IP_VS_IPV6
 918 static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related,
 919                              unsigned int hooknum, struct ip_vs_iphdr *ipvsh)
 920 {
 921         struct icmp6hdr _icmph, *ic;
 922         struct ipv6hdr _ip6h, *ip6h; /* The ip header contained within ICMP */
 923         struct ip_vs_iphdr ciph = {.flags = 0, .fragoffs = 0};/*Contained IP */
 924         struct ip_vs_conn *cp;
 925         struct ip_vs_protocol *pp;
 926         union nf_inet_addr snet;
 927         unsigned int writable;
 928
 929         *related = 1;
 930         ic = frag_safe_skb_hp(skb, ipvsh->len, sizeof(_icmph), &_icmph, ipvsh);
 931         if (ic == NULL)
 932                 return NF_DROP;
 933
 934         /*
 935          * Work through seeing if this is for us.
 936          * These checks are supposed to be in an order that means easy
 937          * things are checked first to speed up processing.... however
 938          * this means that some packets will manage to get a long way
 939          * down this stack and then be rejected, but that's life.
 940          */
 941         if (ic->icmp6_type & ICMPV6_INFOMSG_MASK) {
 942                 *related = 0;
 943                 return NF_ACCEPT;
 944         }
 945         /* Fragment header that is before ICMP header tells us that:
 946          * it's not an error message since they can't be fragmented.
 947          */
 948         if (ipvsh->flags & IP6_FH_F_FRAG)
 949                 return NF_DROP;
 950
 951         IP_VS_DBG(8, "Outgoing ICMPv6 (%d,%d) %pI6c->%pI6c\n",
 952                   ic->icmp6_type, ntohs(icmpv6_id(ic)),
 953                   &ipvsh->saddr, &ipvsh->daddr);
 954
 955         /* Now find the contained IP header */
 956         ciph.len = ipvsh->len + sizeof(_icmph);
 957         ip6h = skb_header_pointer(skb, ciph.len, sizeof(_ip6h), &_ip6h);
 958         if (ip6h == NULL)
 959                 return NF_ACCEPT; /* The packet looks wrong, ignore */
 960         ciph.saddr.in6 = ip6h->saddr; /* conn_out_get() handles reverse order */
 961         ciph.daddr.in6 = ip6h->daddr;
 962         /* skip possible IPv6 exthdrs of contained IPv6 packet */
 963         ciph.protocol = ipv6_find_hdr(skb, &ciph.len, -1, &ciph.fragoffs, NULL);
 964         if (ciph.protocol < 0)
 965                 return NF_ACCEPT; /* Contained IPv6 hdr looks wrong, ignore */
 966
 967         pp = ip_vs_proto_get(ciph.protocol);
 968         if (!pp)
 969                 return NF_ACCEPT;
 970
 971         /* The embedded headers contain source and dest in reverse order */
 972         cp = pp->conn_out_get(AF_INET6, skb, &ciph, 1);
 973         if (!cp)
 974                 return NF_ACCEPT;
 975
 976         snet.in6 = ciph.saddr.in6;
 977         writable = ciph.len;
 978         return handle_response_icmp(AF_INET6, skb, &snet, ciph.protocol, cp,
 979                                     pp, writable, sizeof(struct ipv6hdr));
 980 }
 981 #endif
 982
 983 /*
 984  * Check if sctp chunc is ABORT chunk
 985  */
 986 static inline int is_sctp_abort(const struct sk_buff *skb, int nh_len)
 987 {
 988         sctp_chunkhdr_t *sch, schunk;
 989         sch = skb_header_pointer(skb, nh_len + sizeof(sctp_sctphdr_t),
 990                         sizeof(schunk), &schunk);
 991         if (sch == NULL)
 992                 return 0;
 993         if (sch->type == SCTP_CID_ABORT)
 994                 return 1;
 995         return 0;
 996 }
 997
 998 static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len)
 999 {
1000         struct tcphdr _tcph, *th;
1001
1002         th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph);
1003         if (th == NULL)
1004                 return 0;
1005         return th->rst;
1006 }
1007
1008 /* Handle response packets: rewrite addresses and send away...
1009  */
1010 static unsigned int
1011 handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
1012                 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
1013 {
1014         struct ip_vs_protocol *pp = pd->pp;
1015
1016         IP_VS_DBG_PKT(11, af, pp, skb, 0, "Outgoing packet");
1017
1018         if (!skb_make_writable(skb, iph->len))
1019                 goto drop;
1020
1021         /* mangle the packet */
1022         if (pp->snat_handler && !pp->snat_handler(skb, pp, cp, iph))
1023                 goto drop;
1024
1025 #ifdef CONFIG_IP_VS_IPV6
1026         if (af == AF_INET6)
1027                 ipv6_hdr(skb)->saddr = cp->vaddr.in6;
1028         else
1029 #endif
1030         {
1031                 ip_hdr(skb)->saddr = cp->vaddr.ip;
1032                 ip_send_check(ip_hdr(skb));
1033         }
1034
1035         /*
1036          * nf_iterate does not expect change in the skb->dst->dev.
1037          * It looks like it is not fatal to enable this code for hooks
1038          * where our handlers are at the end of the chain list and
1039          * when all next handlers use skb->dst->dev and not outdev.
1040          * It will definitely route properly the inout NAT traffic
1041          * when multiple paths are used.
1042          */
1043
1044         /* For policy routing, packets originating from this
1045          * machine itself may be routed differently to packets
1046          * passing through.  We want this packet to be routed as
1047          * if it came from this machine itself.  So re-compute
1048          * the routing information.
1049          */
1050         if (ip_vs_route_me_harder(af, skb))
1051                 goto drop;
1052
1053         IP_VS_DBG_PKT(10, af, pp, skb, 0, "After SNAT");
1054
1055         ip_vs_out_stats(cp, skb);
1056         ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd);
1057         skb->ipvs_property = 1;
1058         if (!(cp->flags & IP_VS_CONN_F_NFCT))
1059                 ip_vs_notrack(skb);
1060         else
1061                 ip_vs_update_conntrack(skb, cp, 0);
1062         ip_vs_conn_put(cp);
1063
1064         LeaveFunction(11);
1065         return NF_ACCEPT;
1066
1067 drop:
1068         ip_vs_conn_put(cp);
1069         kfree_skb(skb);
1070         LeaveFunction(11);
1071         return NF_STOLEN;
1072 }
1073
1074 /*
1075  *      Check if outgoing packet belongs to the established ip_vs_conn.
1076  */
1077 static unsigned int
1078 ip_vs_out(unsigned int hooknum, struct sk_buff *skb, int af)
1079 {
1080         struct net *net = NULL;
1081         struct ip_vs_iphdr iph;
1082         struct ip_vs_protocol *pp;
1083         struct ip_vs_proto_data *pd;
1084         struct ip_vs_conn *cp;
1085
1086         EnterFunction(11);
1087
1088         /* Already marked as IPVS request or reply? */
1089         if (skb->ipvs_property)
1090                 return NF_ACCEPT;
1091
1092         /* Bad... Do not break raw sockets */
1093         if (unlikely(skb->sk != NULL && hooknum == NF_INET_LOCAL_OUT &&
1094                      af == AF_INET)) {
1095                 struct sock *sk = skb->sk;
1096                 struct inet_sock *inet = inet_sk(skb->sk);
1097
1098                 if (inet && sk->sk_family == PF_INET && inet->nodefrag)
1099                         return NF_ACCEPT;
1100         }
1101
1102         if (unlikely(!skb_dst(skb)))
1103                 return NF_ACCEPT;
1104
1105         net = skb_net(skb);
1106         if (!net_ipvs(net)->enable)
1107                 return NF_ACCEPT;
1108
1109         ip_vs_fill_iph_skb(af, skb, &iph);
1110 #ifdef CONFIG_IP_VS_IPV6
1111         if (af == AF_INET6) {
1112                 if (!iph.fragoffs && skb_nfct_reasm(skb)) {
1113                         struct sk_buff *reasm = skb_nfct_reasm(skb);
1114                         /* Save fw mark for coming frags */
1115                         reasm->ipvs_property = 1;
1116                         reasm->mark = skb->mark;
1117                 }
1118                 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
1119                         int related;
1120                         int verdict = ip_vs_out_icmp_v6(skb, &related,
1121                                                         hooknum, &iph);
1122
1123                         if (related)
1124                                 return verdict;
1125                 }
1126         } else
1127 #endif
1128                 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1129                         int related;
1130                         int verdict = ip_vs_out_icmp(skb, &related, hooknum);
1131
1132                         if (related)
1133                                 return verdict;
1134                 }
1135
1136         pd = ip_vs_proto_data_get(net, iph.protocol);
1137         if (unlikely(!pd))
1138                 return NF_ACCEPT;
1139         pp = pd->pp;
1140
1141         /* reassemble IP fragments */
1142 #ifdef CONFIG_IP_VS_IPV6
1143         if (af == AF_INET)
1144 #endif
1145                 if (unlikely(ip_is_fragment(ip_hdr(skb)) && !pp->dont_defrag)) {
1146                         if (ip_vs_gather_frags(skb,
1147                                                ip_vs_defrag_user(hooknum)))
1148                                 return NF_STOLEN;
1149
1150                         ip_vs_fill_ip4hdr(skb_network_header(skb), &iph);
1151                 }
1152
1153         /*
1154          * Check if the packet belongs to an existing entry
1155          */
1156         cp = pp->conn_out_get(af, skb, &iph, 0);
1157
1158         if (likely(cp))
1159                 return handle_response(af, skb, pd, cp, &iph);
1160         if (sysctl_nat_icmp_send(net) &&
1161             (pp->protocol == IPPROTO_TCP ||
1162              pp->protocol == IPPROTO_UDP ||
1163              pp->protocol == IPPROTO_SCTP)) {
1164                 __be16 _ports[2], *pptr;
1165
1166                 pptr = frag_safe_skb_hp(skb, iph.len,
1167                                          sizeof(_ports), _ports, &iph);
1168                 if (pptr == NULL)
1169                         return NF_ACCEPT;       /* Not for me */
1170                 if (ip_vs_has_real_service(net, af, iph.protocol, &iph.saddr,
1171                                            pptr[0])) {
1172                         /*
1173                          * Notify the real server: there is no
1174                          * existing entry if it is not RST
1175                          * packet or not TCP packet.
1176                          */
1177                         if ((iph.protocol != IPPROTO_TCP &&
1178                              iph.protocol != IPPROTO_SCTP)
1179                              || ((iph.protocol == IPPROTO_TCP
1180                                   && !is_tcp_reset(skb, iph.len))
1181                                  || (iph.protocol == IPPROTO_SCTP
1182                                         && !is_sctp_abort(skb,
1183                                                 iph.len)))) {
1184 #ifdef CONFIG_IP_VS_IPV6
1185                                 if (af == AF_INET6) {
1186                                         if (!skb->dev)
1187                                                 skb->dev = net->loopback_dev;
1188                                         icmpv6_send(skb,
1189                                                     ICMPV6_DEST_UNREACH,
1190                                                     ICMPV6_PORT_UNREACH,
1191                                                     0);
1192                                 } else
1193 #endif
1194                                         icmp_send(skb,
1195                                                   ICMP_DEST_UNREACH,
1196                                                   ICMP_PORT_UNREACH, 0);
1197                                 return NF_DROP;
1198                         }
1199                 }
1200         }
1201         IP_VS_DBG_PKT(12, af, pp, skb, 0,
1202                       "ip_vs_out: packet continues traversal as normal");
1203         return NF_ACCEPT;
1204 }
1205
1206 /*
1207  *      It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain,
1208  *      used only for VS/NAT.
1209  *      Check if packet is reply for established ip_vs_conn.
1210  */
1211 static unsigned int
1212 ip_vs_reply4(unsigned int hooknum, struct sk_buff *skb,
1213              const struct net_device *in, const struct net_device *out,
1214              int (*okfn)(struct sk_buff *))
1215 {
1216         return ip_vs_out(hooknum, skb, AF_INET);
1217 }
1218
1219 /*
1220  *      It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT.
1221  *      Check if packet is reply for established ip_vs_conn.
1222  */
1223 static unsigned int
1224 ip_vs_local_reply4(unsigned int hooknum, struct sk_buff *skb,
1225                    const struct net_device *in, const struct net_device *out,
1226                    int (*okfn)(struct sk_buff *))
1227 {
1228         unsigned int verdict;
1229
1230         /* Disable BH in LOCAL_OUT until all places are fixed */
1231         local_bh_disable();
1232         verdict = ip_vs_out(hooknum, skb, AF_INET);
1233         local_bh_enable();
1234         return verdict;
1235 }
1236
1237 #ifdef CONFIG_IP_VS_IPV6
1238
1239 /*
1240  *      It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain,
1241  *      used only for VS/NAT.
1242  *      Check if packet is reply for established ip_vs_conn.
1243  */
1244 static unsigned int
1245 ip_vs_reply6(unsigned int hooknum, struct sk_buff *skb,
1246              const struct net_device *in, const struct net_device *out,
1247              int (*okfn)(struct sk_buff *))
1248 {
1249         return ip_vs_out(hooknum, skb, AF_INET6);
1250 }
1251
1252 /*
1253  *      It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT.
1254  *      Check if packet is reply for established ip_vs_conn.
1255  */
1256 static unsigned int
1257 ip_vs_local_reply6(unsigned int hooknum, struct sk_buff *skb,
1258                    const struct net_device *in, const struct net_device *out,
1259                    int (*okfn)(struct sk_buff *))
1260 {
1261         unsigned int verdict;
1262
1263         /* Disable BH in LOCAL_OUT until all places are fixed */
1264         local_bh_disable();
1265         verdict = ip_vs_out(hooknum, skb, AF_INET6);
1266         local_bh_enable();
1267         return verdict;
1268 }
1269
1270 #endif
1271
1272 /*
1273  *      Handle ICMP messages in the outside-to-inside direction (incoming).
1274  *      Find any that might be relevant, check against existing connections,
1275  *      forward to the right destination host if relevant.
1276  *      Currently handles error types - unreachable, quench, ttl exceeded.
1277  */
1278 static int
1279 ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum)
1280 {
1281         struct net *net = NULL;
1282         struct iphdr *iph;
1283         struct icmphdr  _icmph, *ic;
1284         struct iphdr    _ciph, *cih;    /* The ip header contained within the ICMP */
1285         struct ip_vs_iphdr ciph;
1286         struct ip_vs_conn *cp;
1287         struct ip_vs_protocol *pp;
1288         struct ip_vs_proto_data *pd;
1289         unsigned int offset, offset2, ihl, verdict;
1290         bool ipip;
1291
1292         *related = 1;
1293
1294         /* reassemble IP fragments */
1295         if (ip_is_fragment(ip_hdr(skb))) {
1296                 if (ip_vs_gather_frags(skb, ip_vs_defrag_user(hooknum)))
1297                         return NF_STOLEN;
1298         }
1299
1300         iph = ip_hdr(skb);
1301         offset = ihl = iph->ihl * 4;
1302         ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1303         if (ic == NULL)
1304                 return NF_DROP;
1305
1306         IP_VS_DBG(12, "Incoming ICMP (%d,%d) %pI4->%pI4\n",
1307                   ic->type, ntohs(icmp_id(ic)),
1308                   &iph->saddr, &iph->daddr);
1309
1310         /*
1311          * Work through seeing if this is for us.
1312          * These checks are supposed to be in an order that means easy
1313          * things are checked first to speed up processing.... however
1314          * this means that some packets will manage to get a long way
1315          * down this stack and then be rejected, but that's life.
1316          */
1317         if ((ic->type != ICMP_DEST_UNREACH) &&
1318             (ic->type != ICMP_SOURCE_QUENCH) &&
1319             (ic->type != ICMP_TIME_EXCEEDED)) {
1320                 *related = 0;
1321                 return NF_ACCEPT;
1322         }
1323
1324         /* Now find the contained IP header */
1325         offset += sizeof(_icmph);
1326         cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1327         if (cih == NULL)
1328                 return NF_ACCEPT; /* The packet looks wrong, ignore */
1329
1330         net = skb_net(skb);
1331
1332         /* Special case for errors for IPIP packets */
1333         ipip = false;
1334         if (cih->protocol == IPPROTO_IPIP) {
1335                 if (unlikely(cih->frag_off & htons(IP_OFFSET)))
1336                         return NF_ACCEPT;
1337                 /* Error for our IPIP must arrive at LOCAL_IN */
1338                 if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL))
1339                         return NF_ACCEPT;
1340                 offset += cih->ihl * 4;
1341                 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1342                 if (cih == NULL)
1343                         return NF_ACCEPT; /* The packet looks wrong, ignore */
1344                 ipip = true;
1345         }
1346
1347         pd = ip_vs_proto_data_get(net, cih->protocol);
1348         if (!pd)
1349                 return NF_ACCEPT;
1350         pp = pd->pp;
1351
1352         /* Is the embedded protocol header present? */
1353         if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
1354                      pp->dont_defrag))
1355                 return NF_ACCEPT;
1356
1357         IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset,
1358                       "Checking incoming ICMP for");
1359
1360         offset2 = offset;
1361         ip_vs_fill_ip4hdr(cih, &ciph);
1362         ciph.len += offset;
1363         offset = ciph.len;
1364         /* The embedded headers contain source and dest in reverse order.
1365          * For IPIP this is error for request, not for reply.
1366          */
1367         cp = pp->conn_in_get(AF_INET, skb, &ciph, ipip ? 0 : 1);
1368         if (!cp)
1369                 return NF_ACCEPT;
1370
1371         verdict = NF_DROP;
1372
1373         /* Ensure the checksum is correct */
1374         if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
1375                 /* Failed checksum! */
1376                 IP_VS_DBG(1, "Incoming ICMP: failed checksum from %pI4!\n",
1377                           &iph->saddr);
1378                 goto out;
1379         }
1380
1381         if (ipip) {
1382                 __be32 info = ic->un.gateway;
1383
1384                 /* Update the MTU */
1385                 if (ic->type == ICMP_DEST_UNREACH &&
1386                     ic->code == ICMP_FRAG_NEEDED) {
1387                         struct ip_vs_dest *dest = cp->dest;
1388                         u32 mtu = ntohs(ic->un.frag.mtu);
1389
1390                         /* Strip outer IP and ICMP, go to IPIP header */
1391                         __skb_pull(skb, ihl + sizeof(_icmph));
1392                         offset2 -= ihl + sizeof(_icmph);
1393                         skb_reset_network_header(skb);
1394                         IP_VS_DBG(12, "ICMP for IPIP %pI4->%pI4: mtu=%u\n",
1395                                 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, mtu);
1396                         ipv4_update_pmtu(skb, dev_net(skb->dev),
1397                                          mtu, 0, 0, 0, 0);
1398                         /* Client uses PMTUD? */
1399                         if (!(cih->frag_off & htons(IP_DF)))
1400                                 goto ignore_ipip;
1401                         /* Prefer the resulting PMTU */
1402                         if (dest) {
1403                                 struct ip_vs_dest_dst *dest_dst;
1404
1405                                 rcu_read_lock();
1406                                 dest_dst = rcu_dereference(dest->dest_dst);
1407                                 if (dest_dst)
1408                                         mtu = dst_mtu(dest_dst->dst_cache);
1409                                 rcu_read_unlock();
1410                         }
1411                         if (mtu > 68 + sizeof(struct iphdr))
1412                                 mtu -= sizeof(struct iphdr);
1413                         info = htonl(mtu);
1414                 }
1415                 /* Strip outer IP, ICMP and IPIP, go to IP header of
1416                  * original request.
1417                  */
1418                 __skb_pull(skb, offset2);
1419                 skb_reset_network_header(skb);
1420                 IP_VS_DBG(12, "Sending ICMP for %pI4->%pI4: t=%u, c=%u, i=%u\n",
1421                         &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1422                         ic->type, ic->code, ntohl(info));
1423                 icmp_send(skb, ic->type, ic->code, info);
1424                 /* ICMP can be shorter but anyways, account it */
1425                 ip_vs_out_stats(cp, skb);
1426
1427 ignore_ipip:
1428                 consume_skb(skb);
1429                 verdict = NF_STOLEN;
1430                 goto out;
1431         }
1432
1433         /* do the statistics and put it back */
1434         ip_vs_in_stats(cp, skb);
1435         if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
1436                 offset += 2 * sizeof(__u16);
1437         verdict = ip_vs_icmp_xmit(skb, cp, pp, offset, hooknum, &ciph);
1438
1439 out:
1440         __ip_vs_conn_put(cp);
1441
1442         return verdict;
1443 }
1444
1445 #ifdef CONFIG_IP_VS_IPV6
1446 static int ip_vs_in_icmp_v6(struct sk_buff *skb, int *related,
1447                             unsigned int hooknum, struct ip_vs_iphdr *iph)
1448 {
1449         struct net *net = NULL;
1450         struct ipv6hdr _ip6h, *ip6h;
1451         struct icmp6hdr _icmph, *ic;
1452         struct ip_vs_iphdr ciph = {.flags = 0, .fragoffs = 0};/*Contained IP */
1453         struct ip_vs_conn *cp;
1454         struct ip_vs_protocol *pp;
1455         struct ip_vs_proto_data *pd;
1456         unsigned int offs_ciph, writable, verdict;
1457
1458         *related = 1;
1459
1460         ic = frag_safe_skb_hp(skb, iph->len, sizeof(_icmph), &_icmph, iph);
1461         if (ic == NULL)
1462                 return NF_DROP;
1463
1464         /*
1465          * Work through seeing if this is for us.
1466          * These checks are supposed to be in an order that means easy
1467          * things are checked first to speed up processing.... however
1468          * this means that some packets will manage to get a long way
1469          * down this stack and then be rejected, but that's life.
1470          */
1471         if (ic->icmp6_type & ICMPV6_INFOMSG_MASK) {
1472                 *related = 0;
1473                 return NF_ACCEPT;
1474         }
1475         /* Fragment header that is before ICMP header tells us that:
1476          * it's not an error message since they can't be fragmented.
1477          */
1478         if (iph->flags & IP6_FH_F_FRAG)
1479                 return NF_DROP;
1480
1481         IP_VS_DBG(8, "Incoming ICMPv6 (%d,%d) %pI6c->%pI6c\n",
1482                   ic->icmp6_type, ntohs(icmpv6_id(ic)),
1483                   &iph->saddr, &iph->daddr);
1484
1485         /* Now find the contained IP header */
1486         ciph.len = iph->len + sizeof(_icmph);
1487         offs_ciph = ciph.len; /* Save ip header offset */
1488         ip6h = skb_header_pointer(skb, ciph.len, sizeof(_ip6h), &_ip6h);
1489         if (ip6h == NULL)
1490                 return NF_ACCEPT; /* The packet looks wrong, ignore */
1491         ciph.saddr.in6 = ip6h->saddr; /* conn_in_get() handles reverse order */
1492         ciph.daddr.in6 = ip6h->daddr;
1493         /* skip possible IPv6 exthdrs of contained IPv6 packet */
1494         ciph.protocol = ipv6_find_hdr(skb, &ciph.len, -1, &ciph.fragoffs, NULL);
1495         if (ciph.protocol < 0)
1496                 return NF_ACCEPT; /* Contained IPv6 hdr looks wrong, ignore */
1497
1498         net = skb_net(skb);
1499         pd = ip_vs_proto_data_get(net, ciph.protocol);
1500         if (!pd)
1501                 return NF_ACCEPT;
1502         pp = pd->pp;
1503
1504         /* Cannot handle fragmented embedded protocol */
1505         if (ciph.fragoffs)
1506                 return NF_ACCEPT;
1507
1508         IP_VS_DBG_PKT(11, AF_INET6, pp, skb, offs_ciph,
1509                       "Checking incoming ICMPv6 for");
1510
1511         /* The embedded headers contain source and dest in reverse order
1512          * if not from localhost
1513          */
1514         cp = pp->conn_in_get(AF_INET6, skb, &ciph,
1515                              (hooknum == NF_INET_LOCAL_OUT) ? 0 : 1);
1516
1517         if (!cp)
1518                 return NF_ACCEPT;
1519         /* VS/TUN, VS/DR and LOCALNODE just let it go */
1520         if ((hooknum == NF_INET_LOCAL_OUT) &&
1521             (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)) {
1522                 __ip_vs_conn_put(cp);
1523                 return NF_ACCEPT;
1524         }
1525
1526         /* do the statistics and put it back */
1527         ip_vs_in_stats(cp, skb);
1528
1529         /* Need to mangle contained IPv6 header in ICMPv6 packet */
1530         writable = ciph.len;
1531         if (IPPROTO_TCP == ciph.protocol || IPPROTO_UDP == ciph.protocol ||
1532             IPPROTO_SCTP == ciph.protocol)
1533                 writable += 2 * sizeof(__u16); /* Also mangle ports */
1534
1535         verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, writable, hooknum, &ciph);
1536
1537         __ip_vs_conn_put(cp);
1538
1539         return verdict;
1540 }
1541 #endif
1542
1543
1544 /*
1545  *      Check if it's for virtual services, look it up,
1546  *      and send it on its way...
1547  */
1548 static unsigned int
1549 ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
1550 {
1551         struct net *net;
1552         struct ip_vs_iphdr iph;
1553         struct ip_vs_protocol *pp;
1554         struct ip_vs_proto_data *pd;
1555         struct ip_vs_conn *cp;
1556         int ret, pkts;
1557         struct netns_ipvs *ipvs;
1558
1559         /* Already marked as IPVS request or reply? */
1560         if (skb->ipvs_property)
1561                 return NF_ACCEPT;
1562
1563         /*
1564          *      Big tappo:
1565          *      - remote client: only PACKET_HOST
1566          *      - route: used for struct net when skb->dev is unset
1567          */
1568         if (unlikely((skb->pkt_type != PACKET_HOST &&
1569                       hooknum != NF_INET_LOCAL_OUT) ||
1570                      !skb_dst(skb))) {
1571                 ip_vs_fill_iph_skb(af, skb, &iph);
1572                 IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s"
1573                               " ignored in hook %u\n",
1574                               skb->pkt_type, iph.protocol,
1575                               IP_VS_DBG_ADDR(af, &iph.daddr), hooknum);
1576                 return NF_ACCEPT;
1577         }
1578         /* ipvs enabled in this netns ? */
1579         net = skb_net(skb);
1580         ipvs = net_ipvs(net);
1581         if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
1582                 return NF_ACCEPT;
1583
1584         ip_vs_fill_iph_skb(af, skb, &iph);
1585
1586         /* Bad... Do not break raw sockets */
1587         if (unlikely(skb->sk != NULL && hooknum == NF_INET_LOCAL_OUT &&
1588                      af == AF_INET)) {
1589                 struct sock *sk = skb->sk;
1590                 struct inet_sock *inet = inet_sk(skb->sk);
1591
1592                 if (inet && sk->sk_family == PF_INET && inet->nodefrag)
1593                         return NF_ACCEPT;
1594         }
1595
1596 #ifdef CONFIG_IP_VS_IPV6
1597         if (af == AF_INET6) {
1598                 if (!iph.fragoffs && skb_nfct_reasm(skb)) {
1599                         struct sk_buff *reasm = skb_nfct_reasm(skb);
1600                         /* Save fw mark for coming frags. */
1601                         reasm->ipvs_property = 1;
1602                         reasm->mark = skb->mark;
1603                 }
1604                 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
1605                         int related;
1606                         int verdict = ip_vs_in_icmp_v6(skb, &related, hooknum,
1607                                                        &iph);
1608
1609                         if (related)
1610                                 return verdict;
1611                 }
1612         } else
1613 #endif
1614                 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1615                         int related;
1616                         int verdict = ip_vs_in_icmp(skb, &related, hooknum);
1617
1618                         if (related)
1619                                 return verdict;
1620                 }
1621
1622         /* Protocol supported? */
1623         pd = ip_vs_proto_data_get(net, iph.protocol);
1624         if (unlikely(!pd))
1625                 return NF_ACCEPT;
1626         pp = pd->pp;
1627         /*
1628          * Check if the packet belongs to an existing connection entry
1629          */
1630         cp = pp->conn_in_get(af, skb, &iph, 0);
1631         if (unlikely(!cp) && !iph.fragoffs) {
1632                 /* No (second) fragments need to enter here, as nf_defrag_ipv6
1633                  * replayed fragment zero will already have created the cp
1634                  */
1635                 int v;
1636
1637                 /* Schedule and create new connection entry into &cp */
1638                 if (!pp->conn_schedule(af, skb, pd, &v, &cp, &iph))
1639                         return v;
1640         }
1641
1642         if (unlikely(!cp)) {
1643                 /* sorry, all this trouble for a no-hit :) */
1644                 IP_VS_DBG_PKT(12, af, pp, skb, 0,
1645                               "ip_vs_in: packet continues traversal as normal");
1646                 if (iph.fragoffs && !skb_nfct_reasm(skb)) {
1647                         /* Fragment that couldn't be mapped to a conn entry
1648                          * and don't have any pointer to a reasm skb
1649                          * is missing module nf_defrag_ipv6
1650                          */
1651                         IP_VS_DBG_RL("Unhandled frag, load nf_defrag_ipv6\n");
1652                         IP_VS_DBG_PKT(7, af, pp, skb, 0, "unhandled fragment");
1653                 }
1654                 return NF_ACCEPT;
1655         }
1656
1657         IP_VS_DBG_PKT(11, af, pp, skb, 0, "Incoming packet");
1658         /* Check the server status */
1659         if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
1660                 /* the destination server is not available */
1661
1662                 if (sysctl_expire_nodest_conn(ipvs)) {
1663                         /* try to expire the connection immediately */
1664                         ip_vs_conn_expire_now(cp);
1665                 }
1666                 /* don't restart its timer, and silently
1667                    drop the packet. */
1668                 __ip_vs_conn_put(cp);
1669                 return NF_DROP;
1670         }
1671
1672         ip_vs_in_stats(cp, skb);
1673         ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
1674         if (cp->packet_xmit)
1675                 ret = cp->packet_xmit(skb, cp, pp, &iph);
1676                 /* do not touch skb anymore */
1677         else {
1678                 IP_VS_DBG_RL("warning: packet_xmit is null");
1679                 ret = NF_ACCEPT;
1680         }
1681
1682         /* Increase its packet counter and check if it is needed
1683          * to be synchronized
1684          *
1685          * Sync connection if it is about to close to
1686          * encorage the standby servers to update the connections timeout
1687          *
1688          * For ONE_PKT let ip_vs_sync_conn() do the filter work.
1689          */
1690
1691         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
1692                 pkts = sysctl_sync_threshold(ipvs);
1693         else
1694                 pkts = atomic_add_return(1, &cp->in_pkts);
1695
1696         if (ipvs->sync_state & IP_VS_STATE_MASTER)
1697                 ip_vs_sync_conn(net, cp, pkts);
1698
1699         ip_vs_conn_put(cp);
1700         return ret;
1701 }
1702
1703 /*
1704  *      AF_INET handler in NF_INET_LOCAL_IN chain
1705  *      Schedule and forward packets from remote clients
1706  */
1707 static unsigned int
1708 ip_vs_remote_request4(unsigned int hooknum, struct sk_buff *skb,
1709                       const struct net_device *in,
1710                       const struct net_device *out,
1711                       int (*okfn)(struct sk_buff *))
1712 {
1713         return ip_vs_in(hooknum, skb, AF_INET);
1714 }
1715
1716 /*
1717  *      AF_INET handler in NF_INET_LOCAL_OUT chain
1718  *      Schedule and forward packets from local clients
1719  */
1720 static unsigned int
1721 ip_vs_local_request4(unsigned int hooknum, struct sk_buff *skb,
1722                      const struct net_device *in, const struct net_device *out,
1723                      int (*okfn)(struct sk_buff *))
1724 {
1725         unsigned int verdict;
1726
1727         /* Disable BH in LOCAL_OUT until all places are fixed */
1728         local_bh_disable();
1729         verdict = ip_vs_in(hooknum, skb, AF_INET);
1730         local_bh_enable();
1731         return verdict;
1732 }
1733
1734 #ifdef CONFIG_IP_VS_IPV6
1735
1736 /*
1737  * AF_INET6 fragment handling
1738  * Copy info from first fragment, to the rest of them.
1739  */
1740 static unsigned int
1741 ip_vs_preroute_frag6(unsigned int hooknum, struct sk_buff *skb,
1742                      const struct net_device *in,
1743                      const struct net_device *out,
1744                      int (*okfn)(struct sk_buff *))
1745 {
1746         struct sk_buff *reasm = skb_nfct_reasm(skb);
1747         struct net *net;
1748
1749         /* Skip if not a "replay" from nf_ct_frag6_output or first fragment.
1750          * ipvs_property is set when checking first fragment
1751          * in ip_vs_in() and ip_vs_out().
1752          */
1753         if (reasm)
1754                 IP_VS_DBG(2, "Fragment recv prop:%d\n", reasm->ipvs_property);
1755         if (!reasm || !reasm->ipvs_property)
1756                 return NF_ACCEPT;
1757
1758         net = skb_net(skb);
1759         if (!net_ipvs(net)->enable)
1760                 return NF_ACCEPT;
1761
1762         /* Copy stored fw mark, saved in ip_vs_{in,out} */
1763         skb->mark = reasm->mark;
1764
1765         return NF_ACCEPT;
1766 }
1767
1768 /*
1769  *      AF_INET6 handler in NF_INET_LOCAL_IN chain
1770  *      Schedule and forward packets from remote clients
1771  */
1772 static unsigned int
1773 ip_vs_remote_request6(unsigned int hooknum, struct sk_buff *skb,
1774                       const struct net_device *in,
1775                       const struct net_device *out,
1776                       int (*okfn)(struct sk_buff *))
1777 {
1778         return ip_vs_in(hooknum, skb, AF_INET6);
1779 }
1780
1781 /*
1782  *      AF_INET6 handler in NF_INET_LOCAL_OUT chain
1783  *      Schedule and forward packets from local clients
1784  */
1785 static unsigned int
1786 ip_vs_local_request6(unsigned int hooknum, struct sk_buff *skb,
1787                      const struct net_device *in, const struct net_device *out,
1788                      int (*okfn)(struct sk_buff *))
1789 {
1790         unsigned int verdict;
1791
1792         /* Disable BH in LOCAL_OUT until all places are fixed */
1793         local_bh_disable();
1794         verdict = ip_vs_in(hooknum, skb, AF_INET6);
1795         local_bh_enable();
1796         return verdict;
1797 }
1798
1799 #endif
1800
1801
1802 /*
1803  *      It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP
1804  *      related packets destined for 0.0.0.0/0.
1805  *      When fwmark-based virtual service is used, such as transparent
1806  *      cache cluster, TCP packets can be marked and routed to ip_vs_in,
1807  *      but ICMP destined for 0.0.0.0/0 cannot not be easily marked and
1808  *      sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain
1809  *      and send them to ip_vs_in_icmp.
1810  */
1811 static unsigned int
1812 ip_vs_forward_icmp(unsigned int hooknum, struct sk_buff *skb,
1813                    const struct net_device *in, const struct net_device *out,
1814                    int (*okfn)(struct sk_buff *))
1815 {
1816         int r;
1817         struct net *net;
1818         struct netns_ipvs *ipvs;
1819
1820         if (ip_hdr(skb)->protocol != IPPROTO_ICMP)
1821                 return NF_ACCEPT;
1822
1823         /* ipvs enabled in this netns ? */
1824         net = skb_net(skb);
1825         ipvs = net_ipvs(net);
1826         if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
1827                 return NF_ACCEPT;
1828
1829         return ip_vs_in_icmp(skb, &r, hooknum);
1830 }
1831
1832 #ifdef CONFIG_IP_VS_IPV6
1833 static unsigned int
1834 ip_vs_forward_icmp_v6(unsigned int hooknum, struct sk_buff *skb,
1835                       const struct net_device *in, const struct net_device *out,
1836                       int (*okfn)(struct sk_buff *))
1837 {
1838         int r;
1839         struct net *net;
1840         struct netns_ipvs *ipvs;
1841         struct ip_vs_iphdr iphdr;
1842
1843         ip_vs_fill_iph_skb(AF_INET6, skb, &iphdr);
1844         if (iphdr.protocol != IPPROTO_ICMPV6)
1845                 return NF_ACCEPT;
1846
1847         /* ipvs enabled in this netns ? */
1848         net = skb_net(skb);
1849         ipvs = net_ipvs(net);
1850         if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
1851                 return NF_ACCEPT;
1852
1853         return ip_vs_in_icmp_v6(skb, &r, hooknum, &iphdr);
1854 }
1855 #endif
1856
1857
1858 static struct nf_hook_ops ip_vs_ops[] __read_mostly = {
1859         /* After packet filtering, change source only for VS/NAT */
1860         {
1861                 .hook           = ip_vs_reply4,
1862                 .owner          = THIS_MODULE,
1863                 .pf             = NFPROTO_IPV4,
1864                 .hooknum        = NF_INET_LOCAL_IN,
1865                 .priority       = NF_IP_PRI_NAT_SRC - 2,
1866         },
1867         /* After packet filtering, forward packet through VS/DR, VS/TUN,
1868          * or VS/NAT(change destination), so that filtering rules can be
1869          * applied to IPVS. */
1870         {
1871                 .hook           = ip_vs_remote_request4,
1872                 .owner          = THIS_MODULE,
1873                 .pf             = NFPROTO_IPV4,
1874                 .hooknum        = NF_INET_LOCAL_IN,
1875                 .priority       = NF_IP_PRI_NAT_SRC - 1,
1876         },
1877         /* Before ip_vs_in, change source only for VS/NAT */
1878         {
1879                 .hook           = ip_vs_local_reply4,
1880                 .owner          = THIS_MODULE,
1881                 .pf             = NFPROTO_IPV4,
1882                 .hooknum        = NF_INET_LOCAL_OUT,
1883                 .priority       = NF_IP_PRI_NAT_DST + 1,
1884         },
1885         /* After mangle, schedule and forward local requests */
1886         {
1887                 .hook           = ip_vs_local_request4,
1888                 .owner          = THIS_MODULE,
1889                 .pf             = NFPROTO_IPV4,
1890                 .hooknum        = NF_INET_LOCAL_OUT,
1891                 .priority       = NF_IP_PRI_NAT_DST + 2,
1892         },
1893         /* After packet filtering (but before ip_vs_out_icmp), catch icmp
1894          * destined for 0.0.0.0/0, which is for incoming IPVS connections */
1895         {
1896                 .hook           = ip_vs_forward_icmp,
1897                 .owner          = THIS_MODULE,
1898                 .pf             = NFPROTO_IPV4,
1899                 .hooknum        = NF_INET_FORWARD,
1900                 .priority       = 99,
1901         },
1902         /* After packet filtering, change source only for VS/NAT */
1903         {
1904                 .hook           = ip_vs_reply4,
1905                 .owner          = THIS_MODULE,
1906                 .pf             = NFPROTO_IPV4,
1907                 .hooknum        = NF_INET_FORWARD,
1908                 .priority       = 100,
1909         },
1910 #ifdef CONFIG_IP_VS_IPV6
1911         /* After mangle & nat fetch 2:nd fragment and following */
1912         {
1913                 .hook           = ip_vs_preroute_frag6,
1914                 .owner          = THIS_MODULE,
1915                 .pf             = NFPROTO_IPV6,
1916                 .hooknum        = NF_INET_PRE_ROUTING,
1917                 .priority       = NF_IP6_PRI_NAT_DST + 1,
1918         },
1919         /* After packet filtering, change source only for VS/NAT */
1920         {
1921                 .hook           = ip_vs_reply6,
1922                 .owner          = THIS_MODULE,
1923                 .pf             = NFPROTO_IPV6,
1924                 .hooknum        = NF_INET_LOCAL_IN,
1925                 .priority       = NF_IP6_PRI_NAT_SRC - 2,
1926         },
1927         /* After packet filtering, forward packet through VS/DR, VS/TUN,
1928          * or VS/NAT(change destination), so that filtering rules can be
1929          * applied to IPVS. */
1930         {
1931                 .hook           = ip_vs_remote_request6,
1932                 .owner          = THIS_MODULE,
1933                 .pf             = NFPROTO_IPV6,
1934                 .hooknum        = NF_INET_LOCAL_IN,
1935                 .priority       = NF_IP6_PRI_NAT_SRC - 1,
1936         },
1937         /* Before ip_vs_in, change source only for VS/NAT */
1938         {
1939                 .hook           = ip_vs_local_reply6,
1940                 .owner          = THIS_MODULE,
1941                 .pf             = NFPROTO_IPV4,
1942                 .hooknum        = NF_INET_LOCAL_OUT,
1943                 .priority       = NF_IP6_PRI_NAT_DST + 1,
1944         },
1945         /* After mangle, schedule and forward local requests */
1946         {
1947                 .hook           = ip_vs_local_request6,
1948                 .owner          = THIS_MODULE,
1949                 .pf             = NFPROTO_IPV6,
1950                 .hooknum        = NF_INET_LOCAL_OUT,
1951                 .priority       = NF_IP6_PRI_NAT_DST + 2,
1952         },
1953         /* After packet filtering (but before ip_vs_out_icmp), catch icmp
1954          * destined for 0.0.0.0/0, which is for incoming IPVS connections */
1955         {
1956                 .hook           = ip_vs_forward_icmp_v6,
1957                 .owner          = THIS_MODULE,
1958                 .pf             = NFPROTO_IPV6,
1959                 .hooknum        = NF_INET_FORWARD,
1960                 .priority       = 99,
1961         },
1962         /* After packet filtering, change source only for VS/NAT */
1963         {
1964                 .hook           = ip_vs_reply6,
1965                 .owner          = THIS_MODULE,
1966                 .pf             = NFPROTO_IPV6,
1967                 .hooknum        = NF_INET_FORWARD,
1968                 .priority       = 100,
1969         },
1970 #endif
1971 };
1972 /*
1973  *      Initialize IP Virtual Server netns mem.
1974  */
1975 static int __net_init __ip_vs_init(struct net *net)
1976 {
1977         struct netns_ipvs *ipvs;
1978
1979         ipvs = net_generic(net, ip_vs_net_id);
1980         if (ipvs == NULL)
1981                 return -ENOMEM;
1982
1983         /* Hold the beast until a service is registerd */
1984         ipvs->enable = 0;
1985         ipvs->net = net;
1986         /* Counters used for creating unique names */
1987         ipvs->gen = atomic_read(&ipvs_netns_cnt);
1988         atomic_inc(&ipvs_netns_cnt);
1989         net->ipvs = ipvs;
1990
1991         if (ip_vs_estimator_net_init(net) < 0)
1992                 goto estimator_fail;
1993
1994         if (ip_vs_control_net_init(net) < 0)
1995                 goto control_fail;
1996
1997         if (ip_vs_protocol_net_init(net) < 0)
1998                 goto protocol_fail;
1999
2000         if (ip_vs_app_net_init(net) < 0)
2001                 goto app_fail;
2002
2003         if (ip_vs_conn_net_init(net) < 0)
2004                 goto conn_fail;
2005
2006         if (ip_vs_sync_net_init(net) < 0)
2007                 goto sync_fail;
2008
2009         printk(KERN_INFO "IPVS: Creating netns size=%zu id=%d\n",
2010                          sizeof(struct netns_ipvs), ipvs->gen);
2011         return 0;
2012 /*
2013  * Error handling
2014  */
2015
2016 sync_fail:
2017         ip_vs_conn_net_cleanup(net);
2018 conn_fail:
2019         ip_vs_app_net_cleanup(net);
2020 app_fail:
2021         ip_vs_protocol_net_cleanup(net);
2022 protocol_fail:
2023         ip_vs_control_net_cleanup(net);
2024 control_fail:
2025         ip_vs_estimator_net_cleanup(net);
2026 estimator_fail:
2027         net->ipvs = NULL;
2028         return -ENOMEM;
2029 }
2030
2031 static void __net_exit __ip_vs_cleanup(struct net *net)
2032 {
2033         ip_vs_service_net_cleanup(net); /* ip_vs_flush() with locks */
2034         ip_vs_conn_net_cleanup(net);
2035         ip_vs_app_net_cleanup(net);
2036         ip_vs_protocol_net_cleanup(net);
2037         ip_vs_control_net_cleanup(net);
2038         ip_vs_estimator_net_cleanup(net);
2039         IP_VS_DBG(2, "ipvs netns %d released\n", net_ipvs(net)->gen);
2040         net->ipvs = NULL;
2041 }
2042
2043 static void __net_exit __ip_vs_dev_cleanup(struct net *net)
2044 {
2045         EnterFunction(2);
2046         net_ipvs(net)->enable = 0;      /* Disable packet reception */
2047         smp_wmb();
2048         ip_vs_sync_net_cleanup(net);
2049         LeaveFunction(2);
2050 }
2051
2052 static struct pernet_operations ipvs_core_ops = {
2053         .init = __ip_vs_init,
2054         .exit = __ip_vs_cleanup,
2055         .id   = &ip_vs_net_id,
2056         .size = sizeof(struct netns_ipvs),
2057 };
2058
2059 static struct pernet_operations ipvs_core_dev_ops = {
2060         .exit = __ip_vs_dev_cleanup,
2061 };
2062
2063 /*
2064  *      Initialize IP Virtual Server
2065  */
2066 static int __init ip_vs_init(void)
2067 {
2068         int ret;
2069
2070         ret = ip_vs_control_init();
2071         if (ret < 0) {
2072                 pr_err("can't setup control.\n");
2073                 goto exit;
2074         }
2075
2076         ip_vs_protocol_init();
2077
2078         ret = ip_vs_conn_init();
2079         if (ret < 0) {
2080                 pr_err("can't setup connection table.\n");
2081                 goto cleanup_protocol;
2082         }
2083
2084         ret = register_pernet_subsys(&ipvs_core_ops);   /* Alloc ip_vs struct */
2085         if (ret < 0)
2086                 goto cleanup_conn;
2087
2088         ret = register_pernet_device(&ipvs_core_dev_ops);
2089         if (ret < 0)
2090                 goto cleanup_sub;
2091
2092         ret = nf_register_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2093         if (ret < 0) {
2094                 pr_err("can't register hooks.\n");
2095                 goto cleanup_dev;
2096         }
2097
2098         ret = ip_vs_register_nl_ioctl();
2099         if (ret < 0) {
2100                 pr_err("can't register netlink/ioctl.\n");
2101                 goto cleanup_hooks;
2102         }
2103
2104         pr_info("ipvs loaded.\n");
2105
2106         return ret;
2107
2108 cleanup_hooks:
2109         nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2110 cleanup_dev:
2111         unregister_pernet_device(&ipvs_core_dev_ops);
2112 cleanup_sub:
2113         unregister_pernet_subsys(&ipvs_core_ops);
2114 cleanup_conn:
2115         ip_vs_conn_cleanup();
2116 cleanup_protocol:
2117         ip_vs_protocol_cleanup();
2118         ip_vs_control_cleanup();
2119 exit:
2120         return ret;
2121 }
2122
2123 static void __exit ip_vs_cleanup(void)
2124 {
2125         ip_vs_unregister_nl_ioctl();
2126         nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2127         unregister_pernet_device(&ipvs_core_dev_ops);
2128         unregister_pernet_subsys(&ipvs_core_ops);       /* free ip_vs struct */
2129         ip_vs_conn_cleanup();
2130         ip_vs_protocol_cleanup();
2131         ip_vs_control_cleanup();
2132         pr_info("ipvs unloaded.\n");
2133 }
2134
2135 module_init(ip_vs_init);
2136 module_exit(ip_vs_cleanup);
2137 MODULE_LICENSE("GPL");