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/slab.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/jhash.h>
  38 #include <linux/random.h>
  39
  40 #include <net/net_namespace.h>
  41 #include <net/ip_vs.h>
  42
  43
  44 #ifndef CONFIG_IP_VS_TAB_BITS
  45 #define CONFIG_IP_VS_TAB_BITS   12
  46 #endif
  47
  48 /*
  49  * Connection hash size. Default is what was selected at compile time.
  50 */
  51 static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
  52 module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
  53 MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
  54
  55 /* size and mask values */
  56 int ip_vs_conn_tab_size __read_mostly;
  57 static int ip_vs_conn_tab_mask __read_mostly;
  58
  59 /*
  60  *  Connection hash table: for input and output packets lookups of IPVS
  61  */
  62 static struct hlist_head *ip_vs_conn_tab __read_mostly;
  63
  64 /*  SLAB cache for IPVS connections */
  65 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
  66
  67 /*  counter for no client port connections */
  68 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
  69
  70 /* random value for IPVS connection hash */
  71 static unsigned int ip_vs_conn_rnd __read_mostly;
  72
  73 /*
  74  *  Fine locking granularity for big connection hash table
  75  */
  76 #define CT_LOCKARRAY_BITS  5
  77 #define CT_LOCKARRAY_SIZE  (1<<CT_LOCKARRAY_BITS)
  78 #define CT_LOCKARRAY_MASK  (CT_LOCKARRAY_SIZE-1)
  79
  80 struct ip_vs_aligned_lock
  81 {
  82         rwlock_t        l;
  83 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
  84
  85 /* lock array for conn table */
  86 static struct ip_vs_aligned_lock
  87 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
  88
  89 static inline void ct_read_lock(unsigned int key)
  90 {
  91         read_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  92 }
  93
  94 static inline void ct_read_unlock(unsigned int key)
  95 {
  96         read_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  97 }
  98
  99 static inline void ct_write_lock(unsigned int key)
 100 {
 101         write_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 102 }
 103
 104 static inline void ct_write_unlock(unsigned int key)
 105 {
 106         write_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 107 }
 108
 109 static inline void ct_read_lock_bh(unsigned int key)
 110 {
 111         read_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 112 }
 113
 114 static inline void ct_read_unlock_bh(unsigned int key)
 115 {
 116         read_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 117 }
 118
 119 static inline void ct_write_lock_bh(unsigned int key)
 120 {
 121         write_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 122 }
 123
 124 static inline void ct_write_unlock_bh(unsigned int key)
 125 {
 126         write_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 127 }
 128
 129
 130 /*
 131  *      Returns hash value for IPVS connection entry
 132  */
 133 static unsigned int ip_vs_conn_hashkey(struct net *net, int af, unsigned int proto,
 134                                        const union nf_inet_addr *addr,
 135                                        __be16 port)
 136 {
 137 #ifdef CONFIG_IP_VS_IPV6
 138         if (af == AF_INET6)
 139                 return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
 140                                     (__force u32)port, proto, ip_vs_conn_rnd) ^
 141                         ((size_t)net>>8)) & ip_vs_conn_tab_mask;
 142 #endif
 143         return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
 144                             ip_vs_conn_rnd) ^
 145                 ((size_t)net>>8)) & ip_vs_conn_tab_mask;
 146 }
 147
 148 static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p,
 149                                              bool inverse)
 150 {
 151         const union nf_inet_addr *addr;
 152         __be16 port;
 153
 154         if (p->pe_data && p->pe->hashkey_raw)
 155                 return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) &
 156                         ip_vs_conn_tab_mask;
 157
 158         if (likely(!inverse)) {
 159                 addr = p->caddr;
 160                 port = p->cport;
 161         } else {
 162                 addr = p->vaddr;
 163                 port = p->vport;
 164         }
 165
 166         return ip_vs_conn_hashkey(p->net, p->af, p->protocol, addr, port);
 167 }
 168
 169 static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp)
 170 {
 171         struct ip_vs_conn_param p;
 172
 173         ip_vs_conn_fill_param(ip_vs_conn_net(cp), cp->af, cp->protocol,
 174                               &cp->caddr, cp->cport, NULL, 0, &p);
 175
 176         if (cp->pe) {
 177                 p.pe = cp->pe;
 178                 p.pe_data = cp->pe_data;
 179                 p.pe_data_len = cp->pe_data_len;
 180         }
 181
 182         return ip_vs_conn_hashkey_param(&p, false);
 183 }
 184
 185 /*
 186  *      Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port.
 187  *      returns bool success.
 188  */
 189 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
 190 {
 191         unsigned int hash;
 192         int ret;
 193
 194         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 195                 return 0;
 196
 197         /* Hash by protocol, client address and port */
 198         hash = ip_vs_conn_hashkey_conn(cp);
 199
 200         ct_write_lock(hash);
 201         spin_lock(&cp->lock);
 202
 203         if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
 204                 hlist_add_head(&cp->c_list, &ip_vs_conn_tab[hash]);
 205                 cp->flags |= IP_VS_CONN_F_HASHED;
 206                 atomic_inc(&cp->refcnt);
 207                 ret = 1;
 208         } else {
 209                 pr_err("%s(): request for already hashed, called from %pF\n",
 210                        __func__, __builtin_return_address(0));
 211                 ret = 0;
 212         }
 213
 214         spin_unlock(&cp->lock);
 215         ct_write_unlock(hash);
 216
 217         return ret;
 218 }
 219
 220
 221 /*
 222  *      UNhashes ip_vs_conn from ip_vs_conn_tab.
 223  *      returns bool success.
 224  */
 225 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
 226 {
 227         unsigned int hash;
 228         int ret;
 229
 230         /* unhash it and decrease its reference counter */
 231         hash = ip_vs_conn_hashkey_conn(cp);
 232
 233         ct_write_lock(hash);
 234         spin_lock(&cp->lock);
 235
 236         if (cp->flags & IP_VS_CONN_F_HASHED) {
 237                 hlist_del(&cp->c_list);
 238                 cp->flags &= ~IP_VS_CONN_F_HASHED;
 239                 atomic_dec(&cp->refcnt);
 240                 ret = 1;
 241         } else
 242                 ret = 0;
 243
 244         spin_unlock(&cp->lock);
 245         ct_write_unlock(hash);
 246
 247         return ret;
 248 }
 249
 250
 251 /*
 252  *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 253  *  Called for pkts coming from OUTside-to-INside.
 254  *      p->caddr, p->cport: pkt source address (foreign host)
 255  *      p->vaddr, p->vport: pkt dest address (load balancer)
 256  */
 257 static inline struct ip_vs_conn *
 258 __ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
 259 {
 260         unsigned int hash;
 261         struct ip_vs_conn *cp;
 262         struct hlist_node *n;
 263
 264         hash = ip_vs_conn_hashkey_param(p, false);
 265
 266         ct_read_lock(hash);
 267
 268         hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) {
 269                 if (cp->af == p->af &&
 270                     p->cport == cp->cport && p->vport == cp->vport &&
 271                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 272                     ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) &&
 273                     ((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
 274                     p->protocol == cp->protocol &&
 275                     ip_vs_conn_net_eq(cp, p->net)) {
 276                         /* HIT */
 277                         atomic_inc(&cp->refcnt);
 278                         ct_read_unlock(hash);
 279                         return cp;
 280                 }
 281         }
 282
 283         ct_read_unlock(hash);
 284
 285         return NULL;
 286 }
 287
 288 struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
 289 {
 290         struct ip_vs_conn *cp;
 291
 292         cp = __ip_vs_conn_in_get(p);
 293         if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) {
 294                 struct ip_vs_conn_param cport_zero_p = *p;
 295                 cport_zero_p.cport = 0;
 296                 cp = __ip_vs_conn_in_get(&cport_zero_p);
 297         }
 298
 299         IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
 300                       ip_vs_proto_name(p->protocol),
 301                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 302                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 303                       cp ? "hit" : "not hit");
 304
 305         return cp;
 306 }
 307
 308 static int
 309 ip_vs_conn_fill_param_proto(int af, const struct sk_buff *skb,
 310                             const struct ip_vs_iphdr *iph,
 311                             int inverse, struct ip_vs_conn_param *p)
 312 {
 313         __be16 _ports[2], *pptr;
 314         struct net *net = skb_net(skb);
 315
 316         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
 317         if (pptr == NULL)
 318                 return 1;
 319
 320         if (likely(!inverse))
 321                 ip_vs_conn_fill_param(net, af, iph->protocol, &iph->saddr,
 322                                       pptr[0], &iph->daddr, pptr[1], p);
 323         else
 324                 ip_vs_conn_fill_param(net, af, iph->protocol, &iph->daddr,
 325                                       pptr[1], &iph->saddr, pptr[0], p);
 326         return 0;
 327 }
 328
 329 struct ip_vs_conn *
 330 ip_vs_conn_in_get_proto(int af, const struct sk_buff *skb,
 331                         const struct ip_vs_iphdr *iph, int inverse)
 332 {
 333         struct ip_vs_conn_param p;
 334
 335         if (ip_vs_conn_fill_param_proto(af, skb, iph, inverse, &p))
 336                 return NULL;
 337
 338         return ip_vs_conn_in_get(&p);
 339 }
 340 EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
 341
 342 /* Get reference to connection template */
 343 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
 344 {
 345         unsigned int hash;
 346         struct ip_vs_conn *cp;
 347         struct hlist_node *n;
 348
 349         hash = ip_vs_conn_hashkey_param(p, false);
 350
 351         ct_read_lock(hash);
 352
 353         hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) {
 354                 if (!ip_vs_conn_net_eq(cp, p->net))
 355                         continue;
 356                 if (p->pe_data && p->pe->ct_match) {
 357                         if (p->pe == cp->pe && p->pe->ct_match(p, cp))
 358                                 goto out;
 359                         continue;
 360                 }
 361
 362                 if (cp->af == p->af &&
 363                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 364                     /* protocol should only be IPPROTO_IP if
 365                      * p->vaddr is a fwmark */
 366                     ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
 367                                      p->af, p->vaddr, &cp->vaddr) &&
 368                     p->cport == cp->cport && p->vport == cp->vport &&
 369                     cp->flags & IP_VS_CONN_F_TEMPLATE &&
 370                     p->protocol == cp->protocol)
 371                         goto out;
 372         }
 373         cp = NULL;
 374
 375   out:
 376         if (cp)
 377                 atomic_inc(&cp->refcnt);
 378         ct_read_unlock(hash);
 379
 380         IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
 381                       ip_vs_proto_name(p->protocol),
 382                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 383                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 384                       cp ? "hit" : "not hit");
 385
 386         return cp;
 387 }
 388
 389 /* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 390  * Called for pkts coming from inside-to-OUTside.
 391  *      p->caddr, p->cport: pkt source address (inside host)
 392  *      p->vaddr, p->vport: pkt dest address (foreign host) */
 393 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
 394 {
 395         unsigned int hash;
 396         struct ip_vs_conn *cp, *ret=NULL;
 397         struct hlist_node *n;
 398
 399         /*
 400          *      Check for "full" addressed entries
 401          */
 402         hash = ip_vs_conn_hashkey_param(p, true);
 403
 404         ct_read_lock(hash);
 405
 406         hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) {
 407                 if (cp->af == p->af &&
 408                     p->vport == cp->cport && p->cport == cp->dport &&
 409                     ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
 410                     ip_vs_addr_equal(p->af, p->caddr, &cp->daddr) &&
 411                     p->protocol == cp->protocol &&
 412                     ip_vs_conn_net_eq(cp, p->net)) {
 413                         /* HIT */
 414                         atomic_inc(&cp->refcnt);
 415                         ret = cp;
 416                         break;
 417                 }
 418         }
 419
 420         ct_read_unlock(hash);
 421
 422         IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
 423                       ip_vs_proto_name(p->protocol),
 424                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 425                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 426                       ret ? "hit" : "not hit");
 427
 428         return ret;
 429 }
 430
 431 struct ip_vs_conn *
 432 ip_vs_conn_out_get_proto(int af, const struct sk_buff *skb,
 433                          const struct ip_vs_iphdr *iph, int inverse)
 434 {
 435         struct ip_vs_conn_param p;
 436
 437         if (ip_vs_conn_fill_param_proto(af, skb, iph, inverse, &p))
 438                 return NULL;
 439
 440         return ip_vs_conn_out_get(&p);
 441 }
 442 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
 443
 444 /*
 445  *      Put back the conn and restart its timer with its timeout
 446  */
 447 void ip_vs_conn_put(struct ip_vs_conn *cp)
 448 {
 449         unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
 450                 0 : cp->timeout;
 451         mod_timer(&cp->timer, jiffies+t);
 452
 453         __ip_vs_conn_put(cp);
 454 }
 455
 456
 457 /*
 458  *      Fill a no_client_port connection with a client port number
 459  */
 460 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
 461 {
 462         if (ip_vs_conn_unhash(cp)) {
 463                 spin_lock(&cp->lock);
 464                 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
 465                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 466                         cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
 467                         cp->cport = cport;
 468                 }
 469                 spin_unlock(&cp->lock);
 470
 471                 /* hash on new dport */
 472                 ip_vs_conn_hash(cp);
 473         }
 474 }
 475
 476
 477 /*
 478  *      Bind a connection entry with the corresponding packet_xmit.
 479  *      Called by ip_vs_conn_new.
 480  */
 481 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
 482 {
 483         switch (IP_VS_FWD_METHOD(cp)) {
 484         case IP_VS_CONN_F_MASQ:
 485                 cp->packet_xmit = ip_vs_nat_xmit;
 486                 break;
 487
 488         case IP_VS_CONN_F_TUNNEL:
 489                 cp->packet_xmit = ip_vs_tunnel_xmit;
 490                 break;
 491
 492         case IP_VS_CONN_F_DROUTE:
 493                 cp->packet_xmit = ip_vs_dr_xmit;
 494                 break;
 495
 496         case IP_VS_CONN_F_LOCALNODE:
 497                 cp->packet_xmit = ip_vs_null_xmit;
 498                 break;
 499
 500         case IP_VS_CONN_F_BYPASS:
 501                 cp->packet_xmit = ip_vs_bypass_xmit;
 502                 break;
 503         }
 504 }
 505
 506 #ifdef CONFIG_IP_VS_IPV6
 507 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
 508 {
 509         switch (IP_VS_FWD_METHOD(cp)) {
 510         case IP_VS_CONN_F_MASQ:
 511                 cp->packet_xmit = ip_vs_nat_xmit_v6;
 512                 break;
 513
 514         case IP_VS_CONN_F_TUNNEL:
 515                 cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 516                 break;
 517
 518         case IP_VS_CONN_F_DROUTE:
 519                 cp->packet_xmit = ip_vs_dr_xmit_v6;
 520                 break;
 521
 522         case IP_VS_CONN_F_LOCALNODE:
 523                 cp->packet_xmit = ip_vs_null_xmit;
 524                 break;
 525
 526         case IP_VS_CONN_F_BYPASS:
 527                 cp->packet_xmit = ip_vs_bypass_xmit_v6;
 528                 break;
 529         }
 530 }
 531 #endif
 532
 533
 534 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
 535 {
 536         return atomic_read(&dest->activeconns)
 537                 + atomic_read(&dest->inactconns);
 538 }
 539
 540 /*
 541  *      Bind a connection entry with a virtual service destination
 542  *      Called just after a new connection entry is created.
 543  */
 544 static inline void
 545 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
 546 {
 547         unsigned int conn_flags;
 548         __u32 flags;
 549
 550         /* if dest is NULL, then return directly */
 551         if (!dest)
 552                 return;
 553
 554         /* Increase the refcnt counter of the dest */
 555         atomic_inc(&dest->refcnt);
 556
 557         conn_flags = atomic_read(&dest->conn_flags);
 558         if (cp->protocol != IPPROTO_UDP)
 559                 conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
 560         flags = cp->flags;
 561         /* Bind with the destination and its corresponding transmitter */
 562         if (flags & IP_VS_CONN_F_SYNC) {
 563                 /* if the connection is not template and is created
 564                  * by sync, preserve the activity flag.
 565                  */
 566                 if (!(flags & IP_VS_CONN_F_TEMPLATE))
 567                         conn_flags &= ~IP_VS_CONN_F_INACTIVE;
 568                 /* connections inherit forwarding method from dest */
 569                 flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
 570         }
 571         flags |= conn_flags;
 572         cp->flags = flags;
 573         cp->dest = dest;
 574
 575         IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
 576                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 577                       "dest->refcnt:%d\n",
 578                       ip_vs_proto_name(cp->protocol),
 579                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 580                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 581                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
 582                       ip_vs_fwd_tag(cp), cp->state,
 583                       cp->flags, atomic_read(&cp->refcnt),
 584                       atomic_read(&dest->refcnt));
 585
 586         /* Update the connection counters */
 587         if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
 588                 /* It is a normal connection, so modify the counters
 589                  * according to the flags, later the protocol can
 590                  * update them on state change
 591                  */
 592                 if (!(flags & IP_VS_CONN_F_INACTIVE))
 593                         atomic_inc(&dest->activeconns);
 594                 else
 595                         atomic_inc(&dest->inactconns);
 596         } else {
 597                 /* It is a persistent connection/template, so increase
 598                    the persistent connection counter */
 599                 atomic_inc(&dest->persistconns);
 600         }
 601
 602         if (dest->u_threshold != 0 &&
 603             ip_vs_dest_totalconns(dest) >= dest->u_threshold)
 604                 dest->flags |= IP_VS_DEST_F_OVERLOAD;
 605 }
 606
 607
 608 /*
 609  * Check if there is a destination for the connection, if so
 610  * bind the connection to the destination.
 611  */
 612 struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp)
 613 {
 614         struct ip_vs_dest *dest;
 615
 616         dest = ip_vs_find_dest(ip_vs_conn_net(cp), cp->af, &cp->daddr,
 617                                cp->dport, &cp->vaddr, cp->vport,
 618                                cp->protocol, cp->fwmark, cp->flags);
 619         if (dest) {
 620                 struct ip_vs_proto_data *pd;
 621
 622                 spin_lock(&cp->lock);
 623                 if (cp->dest) {
 624                         spin_unlock(&cp->lock);
 625                         return dest;
 626                 }
 627
 628                 /* Applications work depending on the forwarding method
 629                  * but better to reassign them always when binding dest */
 630                 if (cp->app)
 631                         ip_vs_unbind_app(cp);
 632
 633                 ip_vs_bind_dest(cp, dest);
 634                 spin_unlock(&cp->lock);
 635
 636                 /* Update its packet transmitter */
 637                 cp->packet_xmit = NULL;
 638 #ifdef CONFIG_IP_VS_IPV6
 639                 if (cp->af == AF_INET6)
 640                         ip_vs_bind_xmit_v6(cp);
 641                 else
 642 #endif
 643                         ip_vs_bind_xmit(cp);
 644
 645                 pd = ip_vs_proto_data_get(ip_vs_conn_net(cp), cp->protocol);
 646                 if (pd && atomic_read(&pd->appcnt))
 647                         ip_vs_bind_app(cp, pd->pp);
 648         }
 649         return dest;
 650 }
 651
 652
 653 /*
 654  *      Unbind a connection entry with its VS destination
 655  *      Called by the ip_vs_conn_expire function.
 656  */
 657 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
 658 {
 659         struct ip_vs_dest *dest = cp->dest;
 660
 661         if (!dest)
 662                 return;
 663
 664         IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
 665                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 666                       "dest->refcnt:%d\n",
 667                       ip_vs_proto_name(cp->protocol),
 668                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 669                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 670                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
 671                       ip_vs_fwd_tag(cp), cp->state,
 672                       cp->flags, atomic_read(&cp->refcnt),
 673                       atomic_read(&dest->refcnt));
 674
 675         /* Update the connection counters */
 676         if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
 677                 /* It is a normal connection, so decrease the inactconns
 678                    or activeconns counter */
 679                 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
 680                         atomic_dec(&dest->inactconns);
 681                 } else {
 682                         atomic_dec(&dest->activeconns);
 683                 }
 684         } else {
 685                 /* It is a persistent connection/template, so decrease
 686                    the persistent connection counter */
 687                 atomic_dec(&dest->persistconns);
 688         }
 689
 690         if (dest->l_threshold != 0) {
 691                 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
 692                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 693         } else if (dest->u_threshold != 0) {
 694                 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
 695                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 696         } else {
 697                 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 698                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 699         }
 700
 701         /*
 702          * Simply decrease the refcnt of the dest, because the
 703          * dest will be either in service's destination list
 704          * or in the trash.
 705          */
 706         atomic_dec(&dest->refcnt);
 707 }
 708
 709 static int expire_quiescent_template(struct netns_ipvs *ipvs,
 710                                      struct ip_vs_dest *dest)
 711 {
 712 #ifdef CONFIG_SYSCTL
 713         return ipvs->sysctl_expire_quiescent_template &&
 714                 (atomic_read(&dest->weight) == 0);
 715 #else
 716         return 0;
 717 #endif
 718 }
 719
 720 /*
 721  *      Checking if the destination of a connection template is available.
 722  *      If available, return 1, otherwise invalidate this connection
 723  *      template and return 0.
 724  */
 725 int ip_vs_check_template(struct ip_vs_conn *ct)
 726 {
 727         struct ip_vs_dest *dest = ct->dest;
 728         struct netns_ipvs *ipvs = net_ipvs(ip_vs_conn_net(ct));
 729
 730         /*
 731          * Checking the dest server status.
 732          */
 733         if ((dest == NULL) ||
 734             !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
 735             expire_quiescent_template(ipvs, dest)) {
 736                 IP_VS_DBG_BUF(9, "check_template: dest not available for "
 737                               "protocol %s s:%s:%d v:%s:%d "
 738                               "-> d:%s:%d\n",
 739                               ip_vs_proto_name(ct->protocol),
 740                               IP_VS_DBG_ADDR(ct->af, &ct->caddr),
 741                               ntohs(ct->cport),
 742                               IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
 743                               ntohs(ct->vport),
 744                               IP_VS_DBG_ADDR(ct->af, &ct->daddr),
 745                               ntohs(ct->dport));
 746
 747                 /*
 748                  * Invalidate the connection template
 749                  */
 750                 if (ct->vport != htons(0xffff)) {
 751                         if (ip_vs_conn_unhash(ct)) {
 752                                 ct->dport = htons(0xffff);
 753                                 ct->vport = htons(0xffff);
 754                                 ct->cport = 0;
 755                                 ip_vs_conn_hash(ct);
 756                         }
 757                 }
 758
 759                 /*
 760                  * Simply decrease the refcnt of the template,
 761                  * don't restart its timer.
 762                  */
 763                 atomic_dec(&ct->refcnt);
 764                 return 0;
 765         }
 766         return 1;
 767 }
 768
 769 static void ip_vs_conn_expire(unsigned long data)
 770 {
 771         struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
 772         struct net *net = ip_vs_conn_net(cp);
 773         struct netns_ipvs *ipvs = net_ipvs(net);
 774
 775         cp->timeout = 60*HZ;
 776
 777         /*
 778          *      hey, I'm using it
 779          */
 780         atomic_inc(&cp->refcnt);
 781
 782         /*
 783          *      do I control anybody?
 784          */
 785         if (atomic_read(&cp->n_control))
 786                 goto expire_later;
 787
 788         /*
 789          *      unhash it if it is hashed in the conn table
 790          */
 791         if (!ip_vs_conn_unhash(cp) && !(cp->flags & IP_VS_CONN_F_ONE_PACKET))
 792                 goto expire_later;
 793
 794         /*
 795          *      refcnt==1 implies I'm the only one referrer
 796          */
 797         if (likely(atomic_read(&cp->refcnt) == 1)) {
 798                 /* delete the timer if it is activated by other users */
 799                 del_timer(&cp->timer);
 800
 801                 /* does anybody control me? */
 802                 if (cp->control)
 803                         ip_vs_control_del(cp);
 804
 805                 if (cp->flags & IP_VS_CONN_F_NFCT) {
 806                         ip_vs_conn_drop_conntrack(cp);
 807                         /* Do not access conntracks during subsys cleanup
 808                          * because nf_conntrack_find_get can not be used after
 809                          * conntrack cleanup for the net.
 810                          */
 811                         smp_rmb();
 812                         if (ipvs->enable)
 813                                 ip_vs_conn_drop_conntrack(cp);
 814                 }
 815
 816                 ip_vs_pe_put(cp->pe);
 817                 kfree(cp->pe_data);
 818                 if (unlikely(cp->app != NULL))
 819                         ip_vs_unbind_app(cp);
 820                 ip_vs_unbind_dest(cp);
 821                 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
 822                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 823                 atomic_dec(&ipvs->conn_count);
 824
 825                 kmem_cache_free(ip_vs_conn_cachep, cp);
 826                 return;
 827         }
 828
 829         /* hash it back to the table */
 830         ip_vs_conn_hash(cp);
 831
 832   expire_later:
 833         IP_VS_DBG(7, "delayed: conn->refcnt-1=%d conn->n_control=%d\n",
 834                   atomic_read(&cp->refcnt)-1,
 835                   atomic_read(&cp->n_control));
 836
 837         if (ipvs->sync_state & IP_VS_STATE_MASTER)
 838                 ip_vs_sync_conn(net, cp, sysctl_sync_threshold(ipvs));
 839
 840         ip_vs_conn_put(cp);
 841 }
 842
 843
 844 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
 845 {
 846         if (del_timer(&cp->timer))
 847                 mod_timer(&cp->timer, jiffies);
 848 }
 849
 850
 851 /*
 852  *      Create a new connection entry and hash it into the ip_vs_conn_tab
 853  */
 854 struct ip_vs_conn *
 855 ip_vs_conn_new(const struct ip_vs_conn_param *p,
 856                const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
 857                struct ip_vs_dest *dest, __u32 fwmark)
 858 {
 859         struct ip_vs_conn *cp;
 860         struct netns_ipvs *ipvs = net_ipvs(p->net);
 861         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->net,
 862                                                            p->protocol);
 863
 864         cp = kmem_cache_zalloc(ip_vs_conn_cachep, GFP_ATOMIC);
 865         if (cp == NULL) {
 866                 IP_VS_ERR_RL("%s(): no memory\n", __func__);
 867                 return NULL;
 868         }
 869
 870         INIT_HLIST_NODE(&cp->c_list);
 871         setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
 872         ip_vs_conn_net_set(cp, p->net);
 873         cp->af             = p->af;
 874         cp->protocol       = p->protocol;
 875         ip_vs_addr_copy(p->af, &cp->caddr, p->caddr);
 876         cp->cport          = p->cport;
 877         ip_vs_addr_copy(p->af, &cp->vaddr, p->vaddr);
 878         cp->vport          = p->vport;
 879         /* proto should only be IPPROTO_IP if d_addr is a fwmark */
 880         ip_vs_addr_copy(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
 881                         &cp->daddr, daddr);
 882         cp->dport          = dport;
 883         cp->flags          = flags;
 884         cp->fwmark         = fwmark;
 885         if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
 886                 ip_vs_pe_get(p->pe);
 887                 cp->pe = p->pe;
 888                 cp->pe_data = p->pe_data;
 889                 cp->pe_data_len = p->pe_data_len;
 890         }
 891         spin_lock_init(&cp->lock);
 892
 893         /*
 894          * Set the entry is referenced by the current thread before hashing
 895          * it in the table, so that other thread run ip_vs_random_dropentry
 896          * but cannot drop this entry.
 897          */
 898         atomic_set(&cp->refcnt, 1);
 899
 900         atomic_set(&cp->n_control, 0);
 901         atomic_set(&cp->in_pkts, 0);
 902
 903         atomic_inc(&ipvs->conn_count);
 904         if (flags & IP_VS_CONN_F_NO_CPORT)
 905                 atomic_inc(&ip_vs_conn_no_cport_cnt);
 906
 907         /* Bind the connection with a destination server */
 908         ip_vs_bind_dest(cp, dest);
 909
 910         /* Set its state and timeout */
 911         cp->state = 0;
 912         cp->timeout = 3*HZ;
 913         cp->sync_endtime = jiffies & ~3UL;
 914
 915         /* Bind its packet transmitter */
 916 #ifdef CONFIG_IP_VS_IPV6
 917         if (p->af == AF_INET6)
 918                 ip_vs_bind_xmit_v6(cp);
 919         else
 920 #endif
 921                 ip_vs_bind_xmit(cp);
 922
 923         if (unlikely(pd && atomic_read(&pd->appcnt)))
 924                 ip_vs_bind_app(cp, pd->pp);
 925
 926         /*
 927          * Allow conntrack to be preserved. By default, conntrack
 928          * is created and destroyed for every packet.
 929          * Sometimes keeping conntrack can be useful for
 930          * IP_VS_CONN_F_ONE_PACKET too.
 931          */
 932
 933         if (ip_vs_conntrack_enabled(ipvs))
 934                 cp->flags |= IP_VS_CONN_F_NFCT;
 935
 936         /* Hash it in the ip_vs_conn_tab finally */
 937         ip_vs_conn_hash(cp);
 938
 939         return cp;
 940 }
 941
 942 /*
 943  *      /proc/net/ip_vs_conn entries
 944  */
 945 #ifdef CONFIG_PROC_FS
 946 struct ip_vs_iter_state {
 947         struct seq_net_private  p;
 948         struct hlist_head       *l;
 949 };
 950
 951 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
 952 {
 953         int idx;
 954         struct ip_vs_conn *cp;
 955         struct ip_vs_iter_state *iter = seq->private;
 956         struct hlist_node *n;
 957
 958         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
 959                 ct_read_lock_bh(idx);
 960                 hlist_for_each_entry(cp, n, &ip_vs_conn_tab[idx], c_list) {
 961                         if (pos-- == 0) {
 962                                 iter->l = &ip_vs_conn_tab[idx];
 963                                 return cp;
 964                         }
 965                 }
 966                 ct_read_unlock_bh(idx);
 967         }
 968
 969         return NULL;
 970 }
 971
 972 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
 973 {
 974         struct ip_vs_iter_state *iter = seq->private;
 975
 976         iter->l = NULL;
 977         return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
 978 }
 979
 980 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 981 {
 982         struct ip_vs_conn *cp = v;
 983         struct ip_vs_iter_state *iter = seq->private;
 984         struct hlist_node *e;
 985         struct hlist_head *l = iter->l;
 986         int idx;
 987
 988         ++*pos;
 989         if (v == SEQ_START_TOKEN)
 990                 return ip_vs_conn_array(seq, 0);
 991
 992         /* more on same hash chain? */
 993         if ((e = cp->c_list.next))
 994                 return hlist_entry(e, struct ip_vs_conn, c_list);
 995
 996         idx = l - ip_vs_conn_tab;
 997         ct_read_unlock_bh(idx);
 998
 999         while (++idx < ip_vs_conn_tab_size) {
1000                 ct_read_lock_bh(idx);
1001                 hlist_for_each_entry(cp, e, &ip_vs_conn_tab[idx], c_list) {
1002                         iter->l = &ip_vs_conn_tab[idx];
1003                         return cp;
1004                 }
1005                 ct_read_unlock_bh(idx);
1006         }
1007         iter->l = NULL;
1008         return NULL;
1009 }
1010
1011 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1012 {
1013         struct ip_vs_iter_state *iter = seq->private;
1014         struct hlist_head *l = iter->l;
1015
1016         if (l)
1017                 ct_read_unlock_bh(l - ip_vs_conn_tab);
1018 }
1019
1020 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1021 {
1022
1023         if (v == SEQ_START_TOKEN)
1024                 seq_puts(seq,
1025    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires PEName PEData\n");
1026         else {
1027                 const struct ip_vs_conn *cp = v;
1028                 struct net *net = seq_file_net(seq);
1029                 char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1030                 size_t len = 0;
1031
1032                 if (!ip_vs_conn_net_eq(cp, net))
1033                         return 0;
1034                 if (cp->pe_data) {
1035                         pe_data[0] = ' ';
1036                         len = strlen(cp->pe->name);
1037                         memcpy(pe_data + 1, cp->pe->name, len);
1038                         pe_data[len + 1] = ' ';
1039                         len += 2;
1040                         len += cp->pe->show_pe_data(cp, pe_data + len);
1041                 }
1042                 pe_data[len] = '\0';
1043
1044 #ifdef CONFIG_IP_VS_IPV6
1045                 if (cp->af == AF_INET6)
1046                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1047                                 "%pI6 %04X %-11s %7lu%s\n",
1048                                 ip_vs_proto_name(cp->protocol),
1049                                 &cp->caddr.in6, ntohs(cp->cport),
1050                                 &cp->vaddr.in6, ntohs(cp->vport),
1051                                 &cp->daddr.in6, ntohs(cp->dport),
1052                                 ip_vs_state_name(cp->protocol, cp->state),
1053                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1054                 else
1055 #endif
1056                         seq_printf(seq,
1057                                 "%-3s %08X %04X %08X %04X"
1058                                 " %08X %04X %-11s %7lu%s\n",
1059                                 ip_vs_proto_name(cp->protocol),
1060                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1061                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1062                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
1063                                 ip_vs_state_name(cp->protocol, cp->state),
1064                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1065         }
1066         return 0;
1067 }
1068
1069 static const struct seq_operations ip_vs_conn_seq_ops = {
1070         .start = ip_vs_conn_seq_start,
1071         .next  = ip_vs_conn_seq_next,
1072         .stop  = ip_vs_conn_seq_stop,
1073         .show  = ip_vs_conn_seq_show,
1074 };
1075
1076 static int ip_vs_conn_open(struct inode *inode, struct file *file)
1077 {
1078         return seq_open_net(inode, file, &ip_vs_conn_seq_ops,
1079                             sizeof(struct ip_vs_iter_state));
1080 }
1081
1082 static const struct file_operations ip_vs_conn_fops = {
1083         .owner   = THIS_MODULE,
1084         .open    = ip_vs_conn_open,
1085         .read    = seq_read,
1086         .llseek  = seq_lseek,
1087         .release = seq_release_net,
1088 };
1089
1090 static const char *ip_vs_origin_name(unsigned int flags)
1091 {
1092         if (flags & IP_VS_CONN_F_SYNC)
1093                 return "SYNC";
1094         else
1095                 return "LOCAL";
1096 }
1097
1098 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1099 {
1100
1101         if (v == SEQ_START_TOKEN)
1102                 seq_puts(seq,
1103    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
1104         else {
1105                 const struct ip_vs_conn *cp = v;
1106                 struct net *net = seq_file_net(seq);
1107
1108                 if (!ip_vs_conn_net_eq(cp, net))
1109                         return 0;
1110
1111 #ifdef CONFIG_IP_VS_IPV6
1112                 if (cp->af == AF_INET6)
1113                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %-6s %7lu\n",
1114                                 ip_vs_proto_name(cp->protocol),
1115                                 &cp->caddr.in6, ntohs(cp->cport),
1116                                 &cp->vaddr.in6, ntohs(cp->vport),
1117                                 &cp->daddr.in6, ntohs(cp->dport),
1118                                 ip_vs_state_name(cp->protocol, cp->state),
1119                                 ip_vs_origin_name(cp->flags),
1120                                 (cp->timer.expires-jiffies)/HZ);
1121                 else
1122 #endif
1123                         seq_printf(seq,
1124                                 "%-3s %08X %04X %08X %04X "
1125                                 "%08X %04X %-11s %-6s %7lu\n",
1126                                 ip_vs_proto_name(cp->protocol),
1127                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1128                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1129                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
1130                                 ip_vs_state_name(cp->protocol, cp->state),
1131                                 ip_vs_origin_name(cp->flags),
1132                                 (cp->timer.expires-jiffies)/HZ);
1133         }
1134         return 0;
1135 }
1136
1137 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1138         .start = ip_vs_conn_seq_start,
1139         .next  = ip_vs_conn_seq_next,
1140         .stop  = ip_vs_conn_seq_stop,
1141         .show  = ip_vs_conn_sync_seq_show,
1142 };
1143
1144 static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
1145 {
1146         return seq_open_net(inode, file, &ip_vs_conn_sync_seq_ops,
1147                             sizeof(struct ip_vs_iter_state));
1148 }
1149
1150 static const struct file_operations ip_vs_conn_sync_fops = {
1151         .owner   = THIS_MODULE,
1152         .open    = ip_vs_conn_sync_open,
1153         .read    = seq_read,
1154         .llseek  = seq_lseek,
1155         .release = seq_release_net,
1156 };
1157
1158 #endif
1159
1160
1161 /*
1162  *      Randomly drop connection entries before running out of memory
1163  */
1164 static inline int todrop_entry(struct ip_vs_conn *cp)
1165 {
1166         /*
1167          * The drop rate array needs tuning for real environments.
1168          * Called from timer bh only => no locking
1169          */
1170         static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1171         static char todrop_counter[9] = {0};
1172         int i;
1173
1174         /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1175            This will leave enough time for normal connection to get
1176            through. */
1177         if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1178                 return 0;
1179
1180         /* Don't drop the entry if its number of incoming packets is not
1181            located in [0, 8] */
1182         i = atomic_read(&cp->in_pkts);
1183         if (i > 8 || i < 0) return 0;
1184
1185         if (!todrop_rate[i]) return 0;
1186         if (--todrop_counter[i] > 0) return 0;
1187
1188         todrop_counter[i] = todrop_rate[i];
1189         return 1;
1190 }
1191
1192 /* Called from keventd and must protect itself from softirqs */
1193 void ip_vs_random_dropentry(struct net *net)
1194 {
1195         int idx;
1196         struct ip_vs_conn *cp;
1197
1198         /*
1199          * Randomly scan 1/32 of the whole table every second
1200          */
1201         for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1202                 unsigned int hash = net_random() & ip_vs_conn_tab_mask;
1203                 struct hlist_node *n;
1204
1205                 /*
1206                  *  Lock is actually needed in this loop.
1207                  */
1208                 ct_write_lock_bh(hash);
1209
1210                 hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) {
1211                         if (cp->flags & IP_VS_CONN_F_TEMPLATE)
1212                                 /* connection template */
1213                                 continue;
1214                         if (!ip_vs_conn_net_eq(cp, net))
1215                                 continue;
1216                         if (cp->protocol == IPPROTO_TCP) {
1217                                 switch(cp->state) {
1218                                 case IP_VS_TCP_S_SYN_RECV:
1219                                 case IP_VS_TCP_S_SYNACK:
1220                                         break;
1221
1222                                 case IP_VS_TCP_S_ESTABLISHED:
1223                                         if (todrop_entry(cp))
1224                                                 break;
1225                                         continue;
1226
1227                                 default:
1228                                         continue;
1229                                 }
1230                         } else {
1231                                 if (!todrop_entry(cp))
1232                                         continue;
1233                         }
1234
1235                         IP_VS_DBG(4, "del connection\n");
1236                         ip_vs_conn_expire_now(cp);
1237                         if (cp->control) {
1238                                 IP_VS_DBG(4, "del conn template\n");
1239                                 ip_vs_conn_expire_now(cp->control);
1240                         }
1241                 }
1242                 ct_write_unlock_bh(hash);
1243         }
1244 }
1245
1246
1247 /*
1248  *      Flush all the connection entries in the ip_vs_conn_tab
1249  */
1250 static void ip_vs_conn_flush(struct net *net)
1251 {
1252         int idx;
1253         struct ip_vs_conn *cp;
1254         struct netns_ipvs *ipvs = net_ipvs(net);
1255
1256 flush_again:
1257         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1258                 struct hlist_node *n;
1259
1260                 /*
1261                  *  Lock is actually needed in this loop.
1262                  */
1263                 ct_write_lock_bh(idx);
1264
1265                 hlist_for_each_entry(cp, n, &ip_vs_conn_tab[idx], c_list) {
1266                         if (!ip_vs_conn_net_eq(cp, net))
1267                                 continue;
1268                         IP_VS_DBG(4, "del connection\n");
1269                         ip_vs_conn_expire_now(cp);
1270                         if (cp->control) {
1271                                 IP_VS_DBG(4, "del conn template\n");
1272                                 ip_vs_conn_expire_now(cp->control);
1273                         }
1274                 }
1275                 ct_write_unlock_bh(idx);
1276         }
1277
1278         /* the counter may be not NULL, because maybe some conn entries
1279            are run by slow timer handler or unhashed but still referred */
1280         if (atomic_read(&ipvs->conn_count) != 0) {
1281                 schedule();
1282                 goto flush_again;
1283         }
1284 }
1285 /*
1286  * per netns init and exit
1287  */
1288 int __net_init ip_vs_conn_net_init(struct net *net)
1289 {
1290         struct netns_ipvs *ipvs = net_ipvs(net);
1291
1292         atomic_set(&ipvs->conn_count, 0);
1293
1294         proc_net_fops_create(net, "ip_vs_conn", 0, &ip_vs_conn_fops);
1295         proc_net_fops_create(net, "ip_vs_conn_sync", 0, &ip_vs_conn_sync_fops);
1296         return 0;
1297 }
1298
1299 void __net_exit ip_vs_conn_net_cleanup(struct net *net)
1300 {
1301         /* flush all the connection entries first */
1302         ip_vs_conn_flush(net);
1303         proc_net_remove(net, "ip_vs_conn");
1304         proc_net_remove(net, "ip_vs_conn_sync");
1305 }
1306
1307 int __init ip_vs_conn_init(void)
1308 {
1309         int idx;
1310
1311         /* Compute size and mask */
1312         ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1313         ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1314
1315         /*
1316          * Allocate the connection hash table and initialize its list heads
1317          */
1318         ip_vs_conn_tab = vmalloc(ip_vs_conn_tab_size * sizeof(*ip_vs_conn_tab));
1319         if (!ip_vs_conn_tab)
1320                 return -ENOMEM;
1321
1322         /* Allocate ip_vs_conn slab cache */
1323         ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1324                                               sizeof(struct ip_vs_conn), 0,
1325                                               SLAB_HWCACHE_ALIGN, NULL);
1326         if (!ip_vs_conn_cachep) {
1327                 vfree(ip_vs_conn_tab);
1328                 return -ENOMEM;
1329         }
1330
1331         pr_info("Connection hash table configured "
1332                 "(size=%d, memory=%ldKbytes)\n",
1333                 ip_vs_conn_tab_size,
1334                 (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
1335         IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
1336                   sizeof(struct ip_vs_conn));
1337
1338         for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1339                 INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1340
1341         for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1342                 rwlock_init(&__ip_vs_conntbl_lock_array[idx].l);
1343         }
1344
1345         /* calculate the random value for connection hash */
1346         get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1347
1348         return 0;
1349 }
1350
1351 void ip_vs_conn_cleanup(void)
1352 {
1353         /* Release the empty cache */
1354         kmem_cache_destroy(ip_vs_conn_cachep);
1355         vfree(ip_vs_conn_tab);
1356 }