SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/netfilter/ipvs/ip_vs_conn.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. Many code here is taken from IP MASQ code of kernel 2.2.
  20  *
  21  * Changes:
  22  *
  23  */
  24
  25 #define KMSG_COMPONENT "IPVS"
  26 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  27
  28 #include <linux/interrupt.h>
  29 #include <linux/in.h>
  30 #include <linux/net.h>
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/vmalloc.h>
  34 #include <linux/proc_fs.h>              /* for proc_net_* */
  35 #include <linux/seq_file.h>
  36 #include <linux/jhash.h>
  37 #include <linux/random.h>
  38
  39 #include <net/net_namespace.h>
  40 #include <net/ip_vs.h>
  41
  42
  43 /*
  44  *  Connection hash table: for input and output packets lookups of IPVS
  45  */
  46 static struct list_head *ip_vs_conn_tab;
  47
  48 /*  SLAB cache for IPVS connections */
  49 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
  50
  51 /*  counter for current IPVS connections */
  52 static atomic_t ip_vs_conn_count = ATOMIC_INIT(0);
  53
  54 /*  counter for no client port connections */
  55 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
  56
  57 /* random value for IPVS connection hash */
  58 static unsigned int ip_vs_conn_rnd;
  59
  60 /*
  61  *  Fine locking granularity for big connection hash table
  62  */
  63 #define CT_LOCKARRAY_BITS  4
  64 #define CT_LOCKARRAY_SIZE  (1<<CT_LOCKARRAY_BITS)
  65 #define CT_LOCKARRAY_MASK  (CT_LOCKARRAY_SIZE-1)
  66
  67 struct ip_vs_aligned_lock
  68 {
  69         rwlock_t        l;
  70 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
  71
  72 /* lock array for conn table */
  73 static struct ip_vs_aligned_lock
  74 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
  75
  76 static inline void ct_read_lock(unsigned key)
  77 {
  78         read_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  79 }
  80
  81 static inline void ct_read_unlock(unsigned key)
  82 {
  83         read_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  84 }
  85
  86 static inline void ct_write_lock(unsigned key)
  87 {
  88         write_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  89 }
  90
  91 static inline void ct_write_unlock(unsigned key)
  92 {
  93         write_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  94 }
  95
  96 static inline void ct_read_lock_bh(unsigned key)
  97 {
  98         read_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  99 }
 100
 101 static inline void ct_read_unlock_bh(unsigned key)
 102 {
 103         read_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 104 }
 105
 106 static inline void ct_write_lock_bh(unsigned key)
 107 {
 108         write_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 109 }
 110
 111 static inline void ct_write_unlock_bh(unsigned key)
 112 {
 113         write_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 114 }
 115
 116
 117 /*
 118  *      Returns hash value for IPVS connection entry
 119  */
 120 static unsigned int ip_vs_conn_hashkey(int af, unsigned proto,
 121                                        const union nf_inet_addr *addr,
 122                                        __be16 port)
 123 {
 124 #ifdef CONFIG_IP_VS_IPV6
 125         if (af == AF_INET6)
 126                 return jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
 127                                     (__force u32)port, proto, ip_vs_conn_rnd)
 128                         & IP_VS_CONN_TAB_MASK;
 129 #endif
 130         return jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
 131                             ip_vs_conn_rnd)
 132                 & IP_VS_CONN_TAB_MASK;
 133 }
 134
 135
 136 /*
 137  *      Hashes ip_vs_conn in ip_vs_conn_tab by proto,addr,port.
 138  *      returns bool success.
 139  */
 140 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
 141 {
 142         unsigned hash;
 143         int ret;
 144
 145         /* Hash by protocol, client address and port */
 146         hash = ip_vs_conn_hashkey(cp->af, cp->protocol, &cp->caddr, cp->cport);
 147
 148         ct_write_lock(hash);
 149
 150         if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
 151                 list_add(&cp->c_list, &ip_vs_conn_tab[hash]);
 152                 cp->flags |= IP_VS_CONN_F_HASHED;
 153                 atomic_inc(&cp->refcnt);
 154                 ret = 1;
 155         } else {
 156                 pr_err("%s(): request for already hashed, called from %pF\n",
 157                        __func__, __builtin_return_address(0));
 158                 ret = 0;
 159         }
 160
 161         ct_write_unlock(hash);
 162
 163         return ret;
 164 }
 165
 166
 167 /*
 168  *      UNhashes ip_vs_conn from ip_vs_conn_tab.
 169  *      returns bool success.
 170  */
 171 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
 172 {
 173         unsigned hash;
 174         int ret;
 175
 176         /* unhash it and decrease its reference counter */
 177         hash = ip_vs_conn_hashkey(cp->af, cp->protocol, &cp->caddr, cp->cport);
 178
 179         ct_write_lock(hash);
 180
 181         if (cp->flags & IP_VS_CONN_F_HASHED) {
 182                 list_del(&cp->c_list);
 183                 cp->flags &= ~IP_VS_CONN_F_HASHED;
 184                 atomic_dec(&cp->refcnt);
 185                 ret = 1;
 186         } else
 187                 ret = 0;
 188
 189         ct_write_unlock(hash);
 190
 191         return ret;
 192 }
 193
 194
 195 /*
 196  *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 197  *  Called for pkts coming from OUTside-to-INside.
 198  *      s_addr, s_port: pkt source address (foreign host)
 199  *      d_addr, d_port: pkt dest address (load balancer)
 200  */
 201 static inline struct ip_vs_conn *__ip_vs_conn_in_get
 202 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
 203  const union nf_inet_addr *d_addr, __be16 d_port)
 204 {
 205         unsigned hash;
 206         struct ip_vs_conn *cp;
 207
 208         hash = ip_vs_conn_hashkey(af, protocol, s_addr, s_port);
 209
 210         ct_read_lock(hash);
 211
 212         list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
 213                 if (cp->af == af &&
 214                     ip_vs_addr_equal(af, s_addr, &cp->caddr) &&
 215                     ip_vs_addr_equal(af, d_addr, &cp->vaddr) &&
 216                     s_port == cp->cport && d_port == cp->vport &&
 217                     ((!s_port) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
 218                     protocol == cp->protocol) {
 219                         /* HIT */
 220                         atomic_inc(&cp->refcnt);
 221                         ct_read_unlock(hash);
 222                         return cp;
 223                 }
 224         }
 225
 226         ct_read_unlock(hash);
 227
 228         return NULL;
 229 }
 230
 231 struct ip_vs_conn *ip_vs_conn_in_get
 232 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
 233  const union nf_inet_addr *d_addr, __be16 d_port)
 234 {
 235         struct ip_vs_conn *cp;
 236
 237         cp = __ip_vs_conn_in_get(af, protocol, s_addr, s_port, d_addr, d_port);
 238         if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt))
 239                 cp = __ip_vs_conn_in_get(af, protocol, s_addr, 0, d_addr,
 240                                          d_port);
 241
 242         IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
 243                       ip_vs_proto_name(protocol),
 244                       IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
 245                       IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
 246                       cp ? "hit" : "not hit");
 247
 248         return cp;
 249 }
 250
 251 /* Get reference to connection template */
 252 struct ip_vs_conn *ip_vs_ct_in_get
 253 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
 254  const union nf_inet_addr *d_addr, __be16 d_port)
 255 {
 256         unsigned hash;
 257         struct ip_vs_conn *cp;
 258
 259         hash = ip_vs_conn_hashkey(af, protocol, s_addr, s_port);
 260
 261         ct_read_lock(hash);
 262
 263         list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
 264                 if (cp->af == af &&
 265                     ip_vs_addr_equal(af, s_addr, &cp->caddr) &&
 266                     /* protocol should only be IPPROTO_IP if
 267                      * d_addr is a fwmark */
 268                     ip_vs_addr_equal(protocol == IPPROTO_IP ? AF_UNSPEC : af,
 269                                      d_addr, &cp->vaddr) &&
 270                     s_port == cp->cport && d_port == cp->vport &&
 271                     cp->flags & IP_VS_CONN_F_TEMPLATE &&
 272                     protocol == cp->protocol) {
 273                         /* HIT */
 274                         atomic_inc(&cp->refcnt);
 275                         goto out;
 276                 }
 277         }
 278         cp = NULL;
 279
 280   out:
 281         ct_read_unlock(hash);
 282
 283         IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
 284                       ip_vs_proto_name(protocol),
 285                       IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
 286                       IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
 287                       cp ? "hit" : "not hit");
 288
 289         return cp;
 290 }
 291
 292 /*
 293  *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 294  *  Called for pkts coming from inside-to-OUTside.
 295  *      s_addr, s_port: pkt source address (inside host)
 296  *      d_addr, d_port: pkt dest address (foreign host)
 297  */
 298 struct ip_vs_conn *ip_vs_conn_out_get
 299 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
 300  const union nf_inet_addr *d_addr, __be16 d_port)
 301 {
 302         unsigned hash;
 303         struct ip_vs_conn *cp, *ret=NULL;
 304
 305         /*
 306          *      Check for "full" addressed entries
 307          */
 308         hash = ip_vs_conn_hashkey(af, protocol, d_addr, d_port);
 309
 310         ct_read_lock(hash);
 311
 312         list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
 313                 if (cp->af == af &&
 314                     ip_vs_addr_equal(af, d_addr, &cp->caddr) &&
 315                     ip_vs_addr_equal(af, s_addr, &cp->daddr) &&
 316                     d_port == cp->cport && s_port == cp->dport &&
 317                     protocol == cp->protocol) {
 318                         /* HIT */
 319                         atomic_inc(&cp->refcnt);
 320                         ret = cp;
 321                         break;
 322                 }
 323         }
 324
 325         ct_read_unlock(hash);
 326
 327         IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
 328                       ip_vs_proto_name(protocol),
 329                       IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
 330                       IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
 331                       ret ? "hit" : "not hit");
 332
 333         return ret;
 334 }
 335
 336
 337 /*
 338  *      Put back the conn and restart its timer with its timeout
 339  */
 340 void ip_vs_conn_put(struct ip_vs_conn *cp)
 341 {
 342         /* reset it expire in its timeout */
 343         mod_timer(&cp->timer, jiffies+cp->timeout);
 344
 345         __ip_vs_conn_put(cp);
 346 }
 347
 348
 349 /*
 350  *      Fill a no_client_port connection with a client port number
 351  */
 352 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
 353 {
 354         if (ip_vs_conn_unhash(cp)) {
 355                 spin_lock(&cp->lock);
 356                 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
 357                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 358                         cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
 359                         cp->cport = cport;
 360                 }
 361                 spin_unlock(&cp->lock);
 362
 363                 /* hash on new dport */
 364                 ip_vs_conn_hash(cp);
 365         }
 366 }
 367
 368
 369 /*
 370  *      Bind a connection entry with the corresponding packet_xmit.
 371  *      Called by ip_vs_conn_new.
 372  */
 373 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
 374 {
 375         switch (IP_VS_FWD_METHOD(cp)) {
 376         case IP_VS_CONN_F_MASQ:
 377                 cp->packet_xmit = ip_vs_nat_xmit;
 378                 break;
 379
 380         case IP_VS_CONN_F_TUNNEL:
 381                 cp->packet_xmit = ip_vs_tunnel_xmit;
 382                 break;
 383
 384         case IP_VS_CONN_F_DROUTE:
 385                 cp->packet_xmit = ip_vs_dr_xmit;
 386                 break;
 387
 388         case IP_VS_CONN_F_LOCALNODE:
 389                 cp->packet_xmit = ip_vs_null_xmit;
 390                 break;
 391
 392         case IP_VS_CONN_F_BYPASS:
 393                 cp->packet_xmit = ip_vs_bypass_xmit;
 394                 break;
 395         }
 396 }
 397
 398 #ifdef CONFIG_IP_VS_IPV6
 399 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
 400 {
 401         switch (IP_VS_FWD_METHOD(cp)) {
 402         case IP_VS_CONN_F_MASQ:
 403                 cp->packet_xmit = ip_vs_nat_xmit_v6;
 404                 break;
 405
 406         case IP_VS_CONN_F_TUNNEL:
 407                 cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 408                 break;
 409
 410         case IP_VS_CONN_F_DROUTE:
 411                 cp->packet_xmit = ip_vs_dr_xmit_v6;
 412                 break;
 413
 414         case IP_VS_CONN_F_LOCALNODE:
 415                 cp->packet_xmit = ip_vs_null_xmit;
 416                 break;
 417
 418         case IP_VS_CONN_F_BYPASS:
 419                 cp->packet_xmit = ip_vs_bypass_xmit_v6;
 420                 break;
 421         }
 422 }
 423 #endif
 424
 425
 426 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
 427 {
 428         return atomic_read(&dest->activeconns)
 429                 + atomic_read(&dest->inactconns);
 430 }
 431
 432 /*
 433  *      Bind a connection entry with a virtual service destination
 434  *      Called just after a new connection entry is created.
 435  */
 436 static inline void
 437 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
 438 {
 439         /* if dest is NULL, then return directly */
 440         if (!dest)
 441                 return;
 442
 443         /* Increase the refcnt counter of the dest */
 444         atomic_inc(&dest->refcnt);
 445
 446         /* Bind with the destination and its corresponding transmitter */
 447         if ((cp->flags & IP_VS_CONN_F_SYNC) &&
 448             (!(cp->flags & IP_VS_CONN_F_TEMPLATE)))
 449                 /* if the connection is not template and is created
 450                  * by sync, preserve the activity flag.
 451                  */
 452                 cp->flags |= atomic_read(&dest->conn_flags) &
 453                              (~IP_VS_CONN_F_INACTIVE);
 454         else
 455                 cp->flags |= atomic_read(&dest->conn_flags);
 456         cp->dest = dest;
 457
 458         IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
 459                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 460                       "dest->refcnt:%d\n",
 461                       ip_vs_proto_name(cp->protocol),
 462                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 463                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 464                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
 465                       ip_vs_fwd_tag(cp), cp->state,
 466                       cp->flags, atomic_read(&cp->refcnt),
 467                       atomic_read(&dest->refcnt));
 468
 469         /* Update the connection counters */
 470         if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
 471                 /* It is a normal connection, so increase the inactive
 472                    connection counter because it is in TCP SYNRECV
 473                    state (inactive) or other protocol inacive state */
 474                 if ((cp->flags & IP_VS_CONN_F_SYNC) &&
 475                     (!(cp->flags & IP_VS_CONN_F_INACTIVE)))
 476                         atomic_inc(&dest->activeconns);
 477                 else
 478                         atomic_inc(&dest->inactconns);
 479         } else {
 480                 /* It is a persistent connection/template, so increase
 481                    the peristent connection counter */
 482                 atomic_inc(&dest->persistconns);
 483         }
 484
 485         if (dest->u_threshold != 0 &&
 486             ip_vs_dest_totalconns(dest) >= dest->u_threshold)
 487                 dest->flags |= IP_VS_DEST_F_OVERLOAD;
 488 }
 489
 490
 491 /*
 492  * Check if there is a destination for the connection, if so
 493  * bind the connection to the destination.
 494  */
 495 struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp)
 496 {
 497         struct ip_vs_dest *dest;
 498
 499         if ((cp) && (!cp->dest)) {
 500                 dest = ip_vs_find_dest(cp->af, &cp->daddr, cp->dport,
 501                                        &cp->vaddr, cp->vport,
 502                                        cp->protocol);
 503                 ip_vs_bind_dest(cp, dest);
 504                 return dest;
 505         } else
 506                 return NULL;
 507 }
 508
 509
 510 /*
 511  *      Unbind a connection entry with its VS destination
 512  *      Called by the ip_vs_conn_expire function.
 513  */
 514 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
 515 {
 516         struct ip_vs_dest *dest = cp->dest;
 517
 518         if (!dest)
 519                 return;
 520
 521         IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
 522                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 523                       "dest->refcnt:%d\n",
 524                       ip_vs_proto_name(cp->protocol),
 525                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 526                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 527                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
 528                       ip_vs_fwd_tag(cp), cp->state,
 529                       cp->flags, atomic_read(&cp->refcnt),
 530                       atomic_read(&dest->refcnt));
 531
 532         /* Update the connection counters */
 533         if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
 534                 /* It is a normal connection, so decrease the inactconns
 535                    or activeconns counter */
 536                 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
 537                         atomic_dec(&dest->inactconns);
 538                 } else {
 539                         atomic_dec(&dest->activeconns);
 540                 }
 541         } else {
 542                 /* It is a persistent connection/template, so decrease
 543                    the peristent connection counter */
 544                 atomic_dec(&dest->persistconns);
 545         }
 546
 547         if (dest->l_threshold != 0) {
 548                 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
 549                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 550         } else if (dest->u_threshold != 0) {
 551                 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
 552                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 553         } else {
 554                 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 555                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 556         }
 557
 558         /*
 559          * Simply decrease the refcnt of the dest, because the
 560          * dest will be either in service's destination list
 561          * or in the trash.
 562          */
 563         atomic_dec(&dest->refcnt);
 564 }
 565
 566
 567 /*
 568  *      Checking if the destination of a connection template is available.
 569  *      If available, return 1, otherwise invalidate this connection
 570  *      template and return 0.
 571  */
 572 int ip_vs_check_template(struct ip_vs_conn *ct)
 573 {
 574         struct ip_vs_dest *dest = ct->dest;
 575
 576         /*
 577          * Checking the dest server status.
 578          */
 579         if ((dest == NULL) ||
 580             !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
 581             (sysctl_ip_vs_expire_quiescent_template &&
 582              (atomic_read(&dest->weight) == 0))) {
 583                 IP_VS_DBG_BUF(9, "check_template: dest not available for "
 584                               "protocol %s s:%s:%d v:%s:%d "
 585                               "-> d:%s:%d\n",
 586                               ip_vs_proto_name(ct->protocol),
 587                               IP_VS_DBG_ADDR(ct->af, &ct->caddr),
 588                               ntohs(ct->cport),
 589                               IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
 590                               ntohs(ct->vport),
 591                               IP_VS_DBG_ADDR(ct->af, &ct->daddr),
 592                               ntohs(ct->dport));
 593
 594                 /*
 595                  * Invalidate the connection template
 596                  */
 597                 if (ct->vport != htons(0xffff)) {
 598                         if (ip_vs_conn_unhash(ct)) {
 599                                 ct->dport = htons(0xffff);
 600                                 ct->vport = htons(0xffff);
 601                                 ct->cport = 0;
 602                                 ip_vs_conn_hash(ct);
 603                         }
 604                 }
 605
 606                 /*
 607                  * Simply decrease the refcnt of the template,
 608                  * don't restart its timer.
 609                  */
 610                 atomic_dec(&ct->refcnt);
 611                 return 0;
 612         }
 613         return 1;
 614 }
 615
 616 static void ip_vs_conn_expire(unsigned long data)
 617 {
 618         struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
 619
 620         cp->timeout = 60*HZ;
 621
 622         /*
 623          *      hey, I'm using it
 624          */
 625         atomic_inc(&cp->refcnt);
 626
 627         /*
 628          *      do I control anybody?
 629          */
 630         if (atomic_read(&cp->n_control))
 631                 goto expire_later;
 632
 633         /*
 634          *      unhash it if it is hashed in the conn table
 635          */
 636         if (!ip_vs_conn_unhash(cp))
 637                 goto expire_later;
 638
 639         /*
 640          *      refcnt==1 implies I'm the only one referrer
 641          */
 642         if (likely(atomic_read(&cp->refcnt) == 1)) {
 643                 /* delete the timer if it is activated by other users */
 644                 if (timer_pending(&cp->timer))
 645                         del_timer(&cp->timer);
 646
 647                 /* does anybody control me? */
 648                 if (cp->control)
 649                         ip_vs_control_del(cp);
 650
 651                 if (unlikely(cp->app != NULL))
 652                         ip_vs_unbind_app(cp);
 653                 ip_vs_unbind_dest(cp);
 654                 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
 655                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 656                 atomic_dec(&ip_vs_conn_count);
 657
 658                 kmem_cache_free(ip_vs_conn_cachep, cp);
 659                 return;
 660         }
 661
 662         /* hash it back to the table */
 663         ip_vs_conn_hash(cp);
 664
 665   expire_later:
 666         IP_VS_DBG(7, "delayed: conn->refcnt-1=%d conn->n_control=%d\n",
 667                   atomic_read(&cp->refcnt)-1,
 668                   atomic_read(&cp->n_control));
 669
 670         ip_vs_conn_put(cp);
 671 }
 672
 673
 674 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
 675 {
 676         if (del_timer(&cp->timer))
 677                 mod_timer(&cp->timer, jiffies);
 678 }
 679
 680
 681 /*
 682  *      Create a new connection entry and hash it into the ip_vs_conn_tab
 683  */
 684 struct ip_vs_conn *
 685 ip_vs_conn_new(int af, int proto, const union nf_inet_addr *caddr, __be16 cport,
 686                const union nf_inet_addr *vaddr, __be16 vport,
 687                const union nf_inet_addr *daddr, __be16 dport, unsigned flags,
 688                struct ip_vs_dest *dest)
 689 {
 690         struct ip_vs_conn *cp;
 691         struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
 692
 693         cp = kmem_cache_zalloc(ip_vs_conn_cachep, GFP_ATOMIC);
 694         if (cp == NULL) {
 695                 IP_VS_ERR_RL("%s(): no memory\n", __func__);
 696                 return NULL;
 697         }
 698
 699         INIT_LIST_HEAD(&cp->c_list);
 700         setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
 701         cp->af             = af;
 702         cp->protocol       = proto;
 703         ip_vs_addr_copy(af, &cp->caddr, caddr);
 704         cp->cport          = cport;
 705         ip_vs_addr_copy(af, &cp->vaddr, vaddr);
 706         cp->vport          = vport;
 707         /* proto should only be IPPROTO_IP if d_addr is a fwmark */
 708         ip_vs_addr_copy(proto == IPPROTO_IP ? AF_UNSPEC : af,
 709                         &cp->daddr, daddr);
 710         cp->dport          = dport;
 711         cp->flags          = flags;
 712         spin_lock_init(&cp->lock);
 713
 714         /*
 715          * Set the entry is referenced by the current thread before hashing
 716          * it in the table, so that other thread run ip_vs_random_dropentry
 717          * but cannot drop this entry.
 718          */
 719         atomic_set(&cp->refcnt, 1);
 720
 721         atomic_set(&cp->n_control, 0);
 722         atomic_set(&cp->in_pkts, 0);
 723
 724         atomic_inc(&ip_vs_conn_count);
 725         if (flags & IP_VS_CONN_F_NO_CPORT)
 726                 atomic_inc(&ip_vs_conn_no_cport_cnt);
 727
 728         /* Bind the connection with a destination server */
 729         ip_vs_bind_dest(cp, dest);
 730
 731         /* Set its state and timeout */
 732         cp->state = 0;
 733         cp->timeout = 3*HZ;
 734
 735         /* Bind its packet transmitter */
 736 #ifdef CONFIG_IP_VS_IPV6
 737         if (af == AF_INET6)
 738                 ip_vs_bind_xmit_v6(cp);
 739         else
 740 #endif
 741                 ip_vs_bind_xmit(cp);
 742
 743         if (unlikely(pp && atomic_read(&pp->appcnt)))
 744                 ip_vs_bind_app(cp, pp);
 745
 746         /* Hash it in the ip_vs_conn_tab finally */
 747         ip_vs_conn_hash(cp);
 748
 749         return cp;
 750 }
 751
 752
 753 /*
 754  *      /proc/net/ip_vs_conn entries
 755  */
 756 #ifdef CONFIG_PROC_FS
 757
 758 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
 759 {
 760         int idx;
 761         struct ip_vs_conn *cp;
 762
 763         for(idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) {
 764                 ct_read_lock_bh(idx);
 765                 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
 766                         if (pos-- == 0) {
 767                                 seq->private = &ip_vs_conn_tab[idx];
 768                                 return cp;
 769                         }
 770                 }
 771                 ct_read_unlock_bh(idx);
 772         }
 773
 774         return NULL;
 775 }
 776
 777 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
 778 {
 779         seq->private = NULL;
 780         return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
 781 }
 782
 783 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 784 {
 785         struct ip_vs_conn *cp = v;
 786         struct list_head *e, *l = seq->private;
 787         int idx;
 788
 789         ++*pos;
 790         if (v == SEQ_START_TOKEN)
 791                 return ip_vs_conn_array(seq, 0);
 792
 793         /* more on same hash chain? */
 794         if ((e = cp->c_list.next) != l)
 795                 return list_entry(e, struct ip_vs_conn, c_list);
 796
 797         idx = l - ip_vs_conn_tab;
 798         ct_read_unlock_bh(idx);
 799
 800         while (++idx < IP_VS_CONN_TAB_SIZE) {
 801                 ct_read_lock_bh(idx);
 802                 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
 803                         seq->private = &ip_vs_conn_tab[idx];
 804                         return cp;
 805                 }
 806                 ct_read_unlock_bh(idx);
 807         }
 808         seq->private = NULL;
 809         return NULL;
 810 }
 811
 812 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
 813 {
 814         struct list_head *l = seq->private;
 815
 816         if (l)
 817                 ct_read_unlock_bh(l - ip_vs_conn_tab);
 818 }
 819
 820 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
 821 {
 822
 823         if (v == SEQ_START_TOKEN)
 824                 seq_puts(seq,
 825    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires\n");
 826         else {
 827                 const struct ip_vs_conn *cp = v;
 828
 829 #ifdef CONFIG_IP_VS_IPV6
 830                 if (cp->af == AF_INET6)
 831                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %7lu\n",
 832                                 ip_vs_proto_name(cp->protocol),
 833                                 &cp->caddr.in6, ntohs(cp->cport),
 834                                 &cp->vaddr.in6, ntohs(cp->vport),
 835                                 &cp->daddr.in6, ntohs(cp->dport),
 836                                 ip_vs_state_name(cp->protocol, cp->state),
 837                                 (cp->timer.expires-jiffies)/HZ);
 838                 else
 839 #endif
 840                         seq_printf(seq,
 841                                 "%-3s %08X %04X %08X %04X"
 842                                 " %08X %04X %-11s %7lu\n",
 843                                 ip_vs_proto_name(cp->protocol),
 844                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
 845                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
 846                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
 847                                 ip_vs_state_name(cp->protocol, cp->state),
 848                                 (cp->timer.expires-jiffies)/HZ);
 849         }
 850         return 0;
 851 }
 852
 853 static const struct seq_operations ip_vs_conn_seq_ops = {
 854         .start = ip_vs_conn_seq_start,
 855         .next  = ip_vs_conn_seq_next,
 856         .stop  = ip_vs_conn_seq_stop,
 857         .show  = ip_vs_conn_seq_show,
 858 };
 859
 860 static int ip_vs_conn_open(struct inode *inode, struct file *file)
 861 {
 862         return seq_open(file, &ip_vs_conn_seq_ops);
 863 }
 864
 865 static const struct file_operations ip_vs_conn_fops = {
 866         .owner   = THIS_MODULE,
 867         .open    = ip_vs_conn_open,
 868         .read    = seq_read,
 869         .llseek  = seq_lseek,
 870         .release = seq_release,
 871 };
 872
 873 static const char *ip_vs_origin_name(unsigned flags)
 874 {
 875         if (flags & IP_VS_CONN_F_SYNC)
 876                 return "SYNC";
 877         else
 878                 return "LOCAL";
 879 }
 880
 881 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
 882 {
 883
 884         if (v == SEQ_START_TOKEN)
 885                 seq_puts(seq,
 886    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
 887         else {
 888                 const struct ip_vs_conn *cp = v;
 889
 890 #ifdef CONFIG_IP_VS_IPV6
 891                 if (cp->af == AF_INET6)
 892                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %-6s %7lu\n",
 893                                 ip_vs_proto_name(cp->protocol),
 894                                 &cp->caddr.in6, ntohs(cp->cport),
 895                                 &cp->vaddr.in6, ntohs(cp->vport),
 896                                 &cp->daddr.in6, ntohs(cp->dport),
 897                                 ip_vs_state_name(cp->protocol, cp->state),
 898                                 ip_vs_origin_name(cp->flags),
 899                                 (cp->timer.expires-jiffies)/HZ);
 900                 else
 901 #endif
 902                         seq_printf(seq,
 903                                 "%-3s %08X %04X %08X %04X "
 904                                 "%08X %04X %-11s %-6s %7lu\n",
 905                                 ip_vs_proto_name(cp->protocol),
 906                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
 907                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
 908                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
 909                                 ip_vs_state_name(cp->protocol, cp->state),
 910                                 ip_vs_origin_name(cp->flags),
 911                                 (cp->timer.expires-jiffies)/HZ);
 912         }
 913         return 0;
 914 }
 915
 916 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
 917         .start = ip_vs_conn_seq_start,
 918         .next  = ip_vs_conn_seq_next,
 919         .stop  = ip_vs_conn_seq_stop,
 920         .show  = ip_vs_conn_sync_seq_show,
 921 };
 922
 923 static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
 924 {
 925         return seq_open(file, &ip_vs_conn_sync_seq_ops);
 926 }
 927
 928 static const struct file_operations ip_vs_conn_sync_fops = {
 929         .owner   = THIS_MODULE,
 930         .open    = ip_vs_conn_sync_open,
 931         .read    = seq_read,
 932         .llseek  = seq_lseek,
 933         .release = seq_release,
 934 };
 935
 936 #endif
 937
 938
 939 /*
 940  *      Randomly drop connection entries before running out of memory
 941  */
 942 static inline int todrop_entry(struct ip_vs_conn *cp)
 943 {
 944         /*
 945          * The drop rate array needs tuning for real environments.
 946          * Called from timer bh only => no locking
 947          */
 948         static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
 949         static char todrop_counter[9] = {0};
 950         int i;
 951
 952         /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
 953            This will leave enough time for normal connection to get
 954            through. */
 955         if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
 956                 return 0;
 957
 958         /* Don't drop the entry if its number of incoming packets is not
 959            located in [0, 8] */
 960         i = atomic_read(&cp->in_pkts);
 961         if (i > 8 || i < 0) return 0;
 962
 963         if (!todrop_rate[i]) return 0;
 964         if (--todrop_counter[i] > 0) return 0;
 965
 966         todrop_counter[i] = todrop_rate[i];
 967         return 1;
 968 }
 969
 970 /* Called from keventd and must protect itself from softirqs */
 971 void ip_vs_random_dropentry(void)
 972 {
 973         int idx;
 974         struct ip_vs_conn *cp;
 975
 976         /*
 977          * Randomly scan 1/32 of the whole table every second
 978          */
 979         for (idx = 0; idx < (IP_VS_CONN_TAB_SIZE>>5); idx++) {
 980                 unsigned hash = net_random() & IP_VS_CONN_TAB_MASK;
 981
 982                 /*
 983                  *  Lock is actually needed in this loop.
 984                  */
 985                 ct_write_lock_bh(hash);
 986
 987                 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
 988                         if (cp->flags & IP_VS_CONN_F_TEMPLATE)
 989                                 /* connection template */
 990                                 continue;
 991
 992                         if (cp->protocol == IPPROTO_TCP) {
 993                                 switch(cp->state) {
 994                                 case IP_VS_TCP_S_SYN_RECV:
 995                                 case IP_VS_TCP_S_SYNACK:
 996                                         break;
 997
 998                                 case IP_VS_TCP_S_ESTABLISHED:
 999                                         if (todrop_entry(cp))
1000                                                 break;
1001                                         continue;
1002
1003                                 default:
1004                                         continue;
1005                                 }
1006                         } else {
1007                                 if (!todrop_entry(cp))
1008                                         continue;
1009                         }
1010
1011                         IP_VS_DBG(4, "del connection\n");
1012                         ip_vs_conn_expire_now(cp);
1013                         if (cp->control) {
1014                                 IP_VS_DBG(4, "del conn template\n");
1015                                 ip_vs_conn_expire_now(cp->control);
1016                         }
1017                 }
1018                 ct_write_unlock_bh(hash);
1019         }
1020 }
1021
1022
1023 /*
1024  *      Flush all the connection entries in the ip_vs_conn_tab
1025  */
1026 static void ip_vs_conn_flush(void)
1027 {
1028         int idx;
1029         struct ip_vs_conn *cp;
1030
1031   flush_again:
1032         for (idx=0; idx<IP_VS_CONN_TAB_SIZE; idx++) {
1033                 /*
1034                  *  Lock is actually needed in this loop.
1035                  */
1036                 ct_write_lock_bh(idx);
1037
1038                 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
1039
1040                         IP_VS_DBG(4, "del connection\n");
1041                         ip_vs_conn_expire_now(cp);
1042                         if (cp->control) {
1043                                 IP_VS_DBG(4, "del conn template\n");
1044                                 ip_vs_conn_expire_now(cp->control);
1045                         }
1046                 }
1047                 ct_write_unlock_bh(idx);
1048         }
1049
1050         /* the counter may be not NULL, because maybe some conn entries
1051            are run by slow timer handler or unhashed but still referred */
1052         if (atomic_read(&ip_vs_conn_count) != 0) {
1053                 schedule();
1054                 goto flush_again;
1055         }
1056 }
1057
1058
1059 int __init ip_vs_conn_init(void)
1060 {
1061         int idx;
1062
1063         /*
1064          * Allocate the connection hash table and initialize its list heads
1065          */
1066         ip_vs_conn_tab = vmalloc(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head));
1067         if (!ip_vs_conn_tab)
1068                 return -ENOMEM;
1069
1070         /* Allocate ip_vs_conn slab cache */
1071         ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1072                                               sizeof(struct ip_vs_conn), 0,
1073                                               SLAB_HWCACHE_ALIGN, NULL);
1074         if (!ip_vs_conn_cachep) {
1075                 vfree(ip_vs_conn_tab);
1076                 return -ENOMEM;
1077         }
1078
1079         pr_info("Connection hash table configured "
1080                 "(size=%d, memory=%ldKbytes)\n",
1081                 IP_VS_CONN_TAB_SIZE,
1082                 (long)(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head))/1024);
1083         IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
1084                   sizeof(struct ip_vs_conn));
1085
1086         for (idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) {
1087                 INIT_LIST_HEAD(&ip_vs_conn_tab[idx]);
1088         }
1089
1090         for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1091                 rwlock_init(&__ip_vs_conntbl_lock_array[idx].l);
1092         }
1093
1094         proc_net_fops_create(&init_net, "ip_vs_conn", 0, &ip_vs_conn_fops);
1095         proc_net_fops_create(&init_net, "ip_vs_conn_sync", 0, &ip_vs_conn_sync_fops);
1096
1097         /* calculate the random value for connection hash */
1098         get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1099
1100         return 0;
1101 }
1102
1103
1104 void ip_vs_conn_cleanup(void)
1105 {
1106         /* flush all the connection entries first */
1107         ip_vs_conn_flush();
1108
1109         /* Release the empty cache */
1110         kmem_cache_destroy(ip_vs_conn_cachep);
1111         proc_net_remove(&init_net, "ip_vs_conn");
1112         proc_net_remove(&init_net, "ip_vs_conn_sync");
1113         vfree(ip_vs_conn_tab);
1114 }