Pileus Git - ~andy/linux/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/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                             unsigned int proto_off, int inverse,
 312                             struct ip_vs_conn_param *p)
 313 {
 314         __be16 _ports[2], *pptr;
 315         struct net *net = skb_net(skb);
 316
 317         pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
 318         if (pptr == NULL)
 319                 return 1;
 320
 321         if (likely(!inverse))
 322                 ip_vs_conn_fill_param(net, af, iph->protocol, &iph->saddr,
 323                                       pptr[0], &iph->daddr, pptr[1], p);
 324         else
 325                 ip_vs_conn_fill_param(net, af, iph->protocol, &iph->daddr,
 326                                       pptr[1], &iph->saddr, pptr[0], p);
 327         return 0;
 328 }
 329
 330 struct ip_vs_conn *
 331 ip_vs_conn_in_get_proto(int af, const struct sk_buff *skb,
 332                         const struct ip_vs_iphdr *iph,
 333                         unsigned int proto_off, int inverse)
 334 {
 335         struct ip_vs_conn_param p;
 336
 337         if (ip_vs_conn_fill_param_proto(af, skb, iph, proto_off, inverse, &p))
 338                 return NULL;
 339
 340         return ip_vs_conn_in_get(&p);
 341 }
 342 EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
 343
 344 /* Get reference to connection template */
 345 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
 346 {
 347         unsigned int hash;
 348         struct ip_vs_conn *cp;
 349         struct hlist_node *n;
 350
 351         hash = ip_vs_conn_hashkey_param(p, false);
 352
 353         ct_read_lock(hash);
 354
 355         hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) {
 356                 if (!ip_vs_conn_net_eq(cp, p->net))
 357                         continue;
 358                 if (p->pe_data && p->pe->ct_match) {
 359                         if (p->pe == cp->pe && p->pe->ct_match(p, cp))
 360                                 goto out;
 361                         continue;
 362                 }
 363
 364                 if (cp->af == p->af &&
 365                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 366                     /* protocol should only be IPPROTO_IP if
 367                      * p->vaddr is a fwmark */
 368                     ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
 369                                      p->af, p->vaddr, &cp->vaddr) &&
 370                     p->cport == cp->cport && p->vport == cp->vport &&
 371                     cp->flags & IP_VS_CONN_F_TEMPLATE &&
 372                     p->protocol == cp->protocol)
 373                         goto out;
 374         }
 375         cp = NULL;
 376
 377   out:
 378         if (cp)
 379                 atomic_inc(&cp->refcnt);
 380         ct_read_unlock(hash);
 381
 382         IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
 383                       ip_vs_proto_name(p->protocol),
 384                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 385                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 386                       cp ? "hit" : "not hit");
 387
 388         return cp;
 389 }
 390
 391 /* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 392  * Called for pkts coming from inside-to-OUTside.
 393  *      p->caddr, p->cport: pkt source address (inside host)
 394  *      p->vaddr, p->vport: pkt dest address (foreign host) */
 395 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
 396 {
 397         unsigned int hash;
 398         struct ip_vs_conn *cp, *ret=NULL;
 399         struct hlist_node *n;
 400
 401         /*
 402          *      Check for "full" addressed entries
 403          */
 404         hash = ip_vs_conn_hashkey_param(p, true);
 405
 406         ct_read_lock(hash);
 407
 408         hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) {
 409                 if (cp->af == p->af &&
 410                     p->vport == cp->cport && p->cport == cp->dport &&
 411                     ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
 412                     ip_vs_addr_equal(p->af, p->caddr, &cp->daddr) &&
 413                     p->protocol == cp->protocol &&
 414                     ip_vs_conn_net_eq(cp, p->net)) {
 415                         /* HIT */
 416                         atomic_inc(&cp->refcnt);
 417                         ret = cp;
 418                         break;
 419                 }
 420         }
 421
 422         ct_read_unlock(hash);
 423
 424         IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
 425                       ip_vs_proto_name(p->protocol),
 426                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 427                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 428                       ret ? "hit" : "not hit");
 429
 430         return ret;
 431 }
 432
 433 struct ip_vs_conn *
 434 ip_vs_conn_out_get_proto(int af, const struct sk_buff *skb,
 435                          const struct ip_vs_iphdr *iph,
 436                          unsigned int proto_off, int inverse)
 437 {
 438         struct ip_vs_conn_param p;
 439
 440         if (ip_vs_conn_fill_param_proto(af, skb, iph, proto_off, inverse, &p))
 441                 return NULL;
 442
 443         return ip_vs_conn_out_get(&p);
 444 }
 445 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
 446
 447 /*
 448  *      Put back the conn and restart its timer with its timeout
 449  */
 450 void ip_vs_conn_put(struct ip_vs_conn *cp)
 451 {
 452         unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
 453                 0 : cp->timeout;
 454         mod_timer(&cp->timer, jiffies+t);
 455
 456         __ip_vs_conn_put(cp);
 457 }
 458
 459
 460 /*
 461  *      Fill a no_client_port connection with a client port number
 462  */
 463 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
 464 {
 465         if (ip_vs_conn_unhash(cp)) {
 466                 spin_lock(&cp->lock);
 467                 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
 468                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 469                         cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
 470                         cp->cport = cport;
 471                 }
 472                 spin_unlock(&cp->lock);
 473
 474                 /* hash on new dport */
 475                 ip_vs_conn_hash(cp);
 476         }
 477 }
 478
 479
 480 /*
 481  *      Bind a connection entry with the corresponding packet_xmit.
 482  *      Called by ip_vs_conn_new.
 483  */
 484 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
 485 {
 486         switch (IP_VS_FWD_METHOD(cp)) {
 487         case IP_VS_CONN_F_MASQ:
 488                 cp->packet_xmit = ip_vs_nat_xmit;
 489                 break;
 490
 491         case IP_VS_CONN_F_TUNNEL:
 492                 cp->packet_xmit = ip_vs_tunnel_xmit;
 493                 break;
 494
 495         case IP_VS_CONN_F_DROUTE:
 496                 cp->packet_xmit = ip_vs_dr_xmit;
 497                 break;
 498
 499         case IP_VS_CONN_F_LOCALNODE:
 500                 cp->packet_xmit = ip_vs_null_xmit;
 501                 break;
 502
 503         case IP_VS_CONN_F_BYPASS:
 504                 cp->packet_xmit = ip_vs_bypass_xmit;
 505                 break;
 506         }
 507 }
 508
 509 #ifdef CONFIG_IP_VS_IPV6
 510 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
 511 {
 512         switch (IP_VS_FWD_METHOD(cp)) {
 513         case IP_VS_CONN_F_MASQ:
 514                 cp->packet_xmit = ip_vs_nat_xmit_v6;
 515                 break;
 516
 517         case IP_VS_CONN_F_TUNNEL:
 518                 cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 519                 break;
 520
 521         case IP_VS_CONN_F_DROUTE:
 522                 cp->packet_xmit = ip_vs_dr_xmit_v6;
 523                 break;
 524
 525         case IP_VS_CONN_F_LOCALNODE:
 526                 cp->packet_xmit = ip_vs_null_xmit;
 527                 break;
 528
 529         case IP_VS_CONN_F_BYPASS:
 530                 cp->packet_xmit = ip_vs_bypass_xmit_v6;
 531                 break;
 532         }
 533 }
 534 #endif
 535
 536
 537 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
 538 {
 539         return atomic_read(&dest->activeconns)
 540                 + atomic_read(&dest->inactconns);
 541 }
 542
 543 /*
 544  *      Bind a connection entry with a virtual service destination
 545  *      Called just after a new connection entry is created.
 546  */
 547 static inline void
 548 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
 549 {
 550         unsigned int conn_flags;
 551         __u32 flags;
 552
 553         /* if dest is NULL, then return directly */
 554         if (!dest)
 555                 return;
 556
 557         /* Increase the refcnt counter of the dest */
 558         atomic_inc(&dest->refcnt);
 559
 560         conn_flags = atomic_read(&dest->conn_flags);
 561         if (cp->protocol != IPPROTO_UDP)
 562                 conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
 563         flags = cp->flags;
 564         /* Bind with the destination and its corresponding transmitter */
 565         if (flags & IP_VS_CONN_F_SYNC) {
 566                 /* if the connection is not template and is created
 567                  * by sync, preserve the activity flag.
 568                  */
 569                 if (!(flags & IP_VS_CONN_F_TEMPLATE))
 570                         conn_flags &= ~IP_VS_CONN_F_INACTIVE;
 571                 /* connections inherit forwarding method from dest */
 572                 flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
 573         }
 574         flags |= conn_flags;
 575         cp->flags = flags;
 576         cp->dest = dest;
 577
 578         IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
 579                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 580                       "dest->refcnt:%d\n",
 581                       ip_vs_proto_name(cp->protocol),
 582                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 583                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 584                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
 585                       ip_vs_fwd_tag(cp), cp->state,
 586                       cp->flags, atomic_read(&cp->refcnt),
 587                       atomic_read(&dest->refcnt));
 588
 589         /* Update the connection counters */
 590         if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
 591                 /* It is a normal connection, so modify the counters
 592                  * according to the flags, later the protocol can
 593                  * update them on state change
 594                  */
 595                 if (!(flags & IP_VS_CONN_F_INACTIVE))
 596                         atomic_inc(&dest->activeconns);
 597                 else
 598                         atomic_inc(&dest->inactconns);
 599         } else {
 600                 /* It is a persistent connection/template, so increase
 601                    the persistent connection counter */
 602                 atomic_inc(&dest->persistconns);
 603         }
 604
 605         if (dest->u_threshold != 0 &&
 606             ip_vs_dest_totalconns(dest) >= dest->u_threshold)
 607                 dest->flags |= IP_VS_DEST_F_OVERLOAD;
 608 }
 609
 610
 611 /*
 612  * Check if there is a destination for the connection, if so
 613  * bind the connection to the destination.
 614  */
 615 struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp)
 616 {
 617         struct ip_vs_dest *dest;
 618
 619         dest = ip_vs_find_dest(ip_vs_conn_net(cp), cp->af, &cp->daddr,
 620                                cp->dport, &cp->vaddr, cp->vport,
 621                                cp->protocol, cp->fwmark, cp->flags);
 622         if (dest) {
 623                 struct ip_vs_proto_data *pd;
 624
 625                 spin_lock(&cp->lock);
 626                 if (cp->dest) {
 627                         spin_unlock(&cp->lock);
 628                         return dest;
 629                 }
 630
 631                 /* Applications work depending on the forwarding method
 632                  * but better to reassign them always when binding dest */
 633                 if (cp->app)
 634                         ip_vs_unbind_app(cp);
 635
 636                 ip_vs_bind_dest(cp, dest);
 637                 spin_unlock(&cp->lock);
 638
 639                 /* Update its packet transmitter */
 640                 cp->packet_xmit = NULL;
 641 #ifdef CONFIG_IP_VS_IPV6
 642                 if (cp->af == AF_INET6)
 643                         ip_vs_bind_xmit_v6(cp);
 644                 else
 645 #endif
 646                         ip_vs_bind_xmit(cp);
 647
 648                 pd = ip_vs_proto_data_get(ip_vs_conn_net(cp), cp->protocol);
 649                 if (pd && atomic_read(&pd->appcnt))
 650                         ip_vs_bind_app(cp, pd->pp);
 651         }
 652         return dest;
 653 }
 654
 655
 656 /*
 657  *      Unbind a connection entry with its VS destination
 658  *      Called by the ip_vs_conn_expire function.
 659  */
 660 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
 661 {
 662         struct ip_vs_dest *dest = cp->dest;
 663
 664         if (!dest)
 665                 return;
 666
 667         IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
 668                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 669                       "dest->refcnt:%d\n",
 670                       ip_vs_proto_name(cp->protocol),
 671                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 672                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 673                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
 674                       ip_vs_fwd_tag(cp), cp->state,
 675                       cp->flags, atomic_read(&cp->refcnt),
 676                       atomic_read(&dest->refcnt));
 677
 678         /* Update the connection counters */
 679         if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
 680                 /* It is a normal connection, so decrease the inactconns
 681                    or activeconns counter */
 682                 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
 683                         atomic_dec(&dest->inactconns);
 684                 } else {
 685                         atomic_dec(&dest->activeconns);
 686                 }
 687         } else {
 688                 /* It is a persistent connection/template, so decrease
 689                    the persistent connection counter */
 690                 atomic_dec(&dest->persistconns);
 691         }
 692
 693         if (dest->l_threshold != 0) {
 694                 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
 695                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 696         } else if (dest->u_threshold != 0) {
 697                 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
 698                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 699         } else {
 700                 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 701                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 702         }
 703
 704         /*
 705          * Simply decrease the refcnt of the dest, because the
 706          * dest will be either in service's destination list
 707          * or in the trash.
 708          */
 709         atomic_dec(&dest->refcnt);
 710 }
 711
 712 static int expire_quiescent_template(struct netns_ipvs *ipvs,
 713                                      struct ip_vs_dest *dest)
 714 {
 715 #ifdef CONFIG_SYSCTL
 716         return ipvs->sysctl_expire_quiescent_template &&
 717                 (atomic_read(&dest->weight) == 0);
 718 #else
 719         return 0;
 720 #endif
 721 }
 722
 723 /*
 724  *      Checking if the destination of a connection template is available.
 725  *      If available, return 1, otherwise invalidate this connection
 726  *      template and return 0.
 727  */
 728 int ip_vs_check_template(struct ip_vs_conn *ct)
 729 {
 730         struct ip_vs_dest *dest = ct->dest;
 731         struct netns_ipvs *ipvs = net_ipvs(ip_vs_conn_net(ct));
 732
 733         /*
 734          * Checking the dest server status.
 735          */
 736         if ((dest == NULL) ||
 737             !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
 738             expire_quiescent_template(ipvs, dest)) {
 739                 IP_VS_DBG_BUF(9, "check_template: dest not available for "
 740                               "protocol %s s:%s:%d v:%s:%d "
 741                               "-> d:%s:%d\n",
 742                               ip_vs_proto_name(ct->protocol),
 743                               IP_VS_DBG_ADDR(ct->af, &ct->caddr),
 744                               ntohs(ct->cport),
 745                               IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
 746                               ntohs(ct->vport),
 747                               IP_VS_DBG_ADDR(ct->af, &ct->daddr),
 748                               ntohs(ct->dport));
 749
 750                 /*
 751                  * Invalidate the connection template
 752                  */
 753                 if (ct->vport != htons(0xffff)) {
 754                         if (ip_vs_conn_unhash(ct)) {
 755                                 ct->dport = htons(0xffff);
 756                                 ct->vport = htons(0xffff);
 757                                 ct->cport = 0;
 758                                 ip_vs_conn_hash(ct);
 759                         }
 760                 }
 761
 762                 /*
 763                  * Simply decrease the refcnt of the template,
 764                  * don't restart its timer.
 765                  */
 766                 atomic_dec(&ct->refcnt);
 767                 return 0;
 768         }
 769         return 1;
 770 }
 771
 772 static void ip_vs_conn_expire(unsigned long data)
 773 {
 774         struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
 775         struct net *net = ip_vs_conn_net(cp);
 776         struct netns_ipvs *ipvs = net_ipvs(net);
 777
 778         cp->timeout = 60*HZ;
 779
 780         /*
 781          *      hey, I'm using it
 782          */
 783         atomic_inc(&cp->refcnt);
 784
 785         /*
 786          *      do I control anybody?
 787          */
 788         if (atomic_read(&cp->n_control))
 789                 goto expire_later;
 790
 791         /*
 792          *      unhash it if it is hashed in the conn table
 793          */
 794         if (!ip_vs_conn_unhash(cp) && !(cp->flags & IP_VS_CONN_F_ONE_PACKET))
 795                 goto expire_later;
 796
 797         /*
 798          *      refcnt==1 implies I'm the only one referrer
 799          */
 800         if (likely(atomic_read(&cp->refcnt) == 1)) {
 801                 /* delete the timer if it is activated by other users */
 802                 if (timer_pending(&cp->timer))
 803                         del_timer(&cp->timer);
 804
 805                 /* does anybody control me? */
 806                 if (cp->control)
 807                         ip_vs_control_del(cp);
 808
 809                 if (cp->flags & IP_VS_CONN_F_NFCT) {
 810                         ip_vs_conn_drop_conntrack(cp);
 811                         /* Do not access conntracks during subsys cleanup
 812                          * because nf_conntrack_find_get can not be used after
 813                          * conntrack cleanup for the net.
 814                          */
 815                         smp_rmb();
 816                         if (ipvs->enable)
 817                                 ip_vs_conn_drop_conntrack(cp);
 818                 }
 819
 820                 ip_vs_pe_put(cp->pe);
 821                 kfree(cp->pe_data);
 822                 if (unlikely(cp->app != NULL))
 823                         ip_vs_unbind_app(cp);
 824                 ip_vs_unbind_dest(cp);
 825                 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
 826                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 827                 atomic_dec(&ipvs->conn_count);
 828
 829                 kmem_cache_free(ip_vs_conn_cachep, cp);
 830                 return;
 831         }
 832
 833         /* hash it back to the table */
 834         ip_vs_conn_hash(cp);
 835
 836   expire_later:
 837         IP_VS_DBG(7, "delayed: conn->refcnt-1=%d conn->n_control=%d\n",
 838                   atomic_read(&cp->refcnt)-1,
 839                   atomic_read(&cp->n_control));
 840
 841         if (ipvs->sync_state & IP_VS_STATE_MASTER)
 842                 ip_vs_sync_conn(net, cp, sysctl_sync_threshold(ipvs));
 843
 844         ip_vs_conn_put(cp);
 845 }
 846
 847
 848 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
 849 {
 850         if (del_timer(&cp->timer))
 851                 mod_timer(&cp->timer, jiffies);
 852 }
 853
 854
 855 /*
 856  *      Create a new connection entry and hash it into the ip_vs_conn_tab
 857  */
 858 struct ip_vs_conn *
 859 ip_vs_conn_new(const struct ip_vs_conn_param *p,
 860                const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
 861                struct ip_vs_dest *dest, __u32 fwmark)
 862 {
 863         struct ip_vs_conn *cp;
 864         struct netns_ipvs *ipvs = net_ipvs(p->net);
 865         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->net,
 866                                                            p->protocol);
 867
 868         cp = kmem_cache_zalloc(ip_vs_conn_cachep, GFP_ATOMIC);
 869         if (cp == NULL) {
 870                 IP_VS_ERR_RL("%s(): no memory\n", __func__);
 871                 return NULL;
 872         }
 873
 874         INIT_HLIST_NODE(&cp->c_list);
 875         setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
 876         ip_vs_conn_net_set(cp, p->net);
 877         cp->af             = p->af;
 878         cp->protocol       = p->protocol;
 879         ip_vs_addr_copy(p->af, &cp->caddr, p->caddr);
 880         cp->cport          = p->cport;
 881         ip_vs_addr_copy(p->af, &cp->vaddr, p->vaddr);
 882         cp->vport          = p->vport;
 883         /* proto should only be IPPROTO_IP if d_addr is a fwmark */
 884         ip_vs_addr_copy(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
 885                         &cp->daddr, daddr);
 886         cp->dport          = dport;
 887         cp->flags          = flags;
 888         cp->fwmark         = fwmark;
 889         if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
 890                 ip_vs_pe_get(p->pe);
 891                 cp->pe = p->pe;
 892                 cp->pe_data = p->pe_data;
 893                 cp->pe_data_len = p->pe_data_len;
 894         }
 895         spin_lock_init(&cp->lock);
 896
 897         /*
 898          * Set the entry is referenced by the current thread before hashing
 899          * it in the table, so that other thread run ip_vs_random_dropentry
 900          * but cannot drop this entry.
 901          */
 902         atomic_set(&cp->refcnt, 1);
 903
 904         atomic_set(&cp->n_control, 0);
 905         atomic_set(&cp->in_pkts, 0);
 906
 907         atomic_inc(&ipvs->conn_count);
 908         if (flags & IP_VS_CONN_F_NO_CPORT)
 909                 atomic_inc(&ip_vs_conn_no_cport_cnt);
 910
 911         /* Bind the connection with a destination server */
 912         ip_vs_bind_dest(cp, dest);
 913
 914         /* Set its state and timeout */
 915         cp->state = 0;
 916         cp->timeout = 3*HZ;
 917         cp->sync_endtime = jiffies & ~3UL;
 918
 919         /* Bind its packet transmitter */
 920 #ifdef CONFIG_IP_VS_IPV6
 921         if (p->af == AF_INET6)
 922                 ip_vs_bind_xmit_v6(cp);
 923         else
 924 #endif
 925                 ip_vs_bind_xmit(cp);
 926
 927         if (unlikely(pd && atomic_read(&pd->appcnt)))
 928                 ip_vs_bind_app(cp, pd->pp);
 929
 930         /*
 931          * Allow conntrack to be preserved. By default, conntrack
 932          * is created and destroyed for every packet.
 933          * Sometimes keeping conntrack can be useful for
 934          * IP_VS_CONN_F_ONE_PACKET too.
 935          */
 936
 937         if (ip_vs_conntrack_enabled(ipvs))
 938                 cp->flags |= IP_VS_CONN_F_NFCT;
 939
 940         /* Hash it in the ip_vs_conn_tab finally */
 941         ip_vs_conn_hash(cp);
 942
 943         return cp;
 944 }
 945
 946 /*
 947  *      /proc/net/ip_vs_conn entries
 948  */
 949 #ifdef CONFIG_PROC_FS
 950 struct ip_vs_iter_state {
 951         struct seq_net_private  p;
 952         struct hlist_head       *l;
 953 };
 954
 955 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
 956 {
 957         int idx;
 958         struct ip_vs_conn *cp;
 959         struct ip_vs_iter_state *iter = seq->private;
 960         struct hlist_node *n;
 961
 962         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
 963                 ct_read_lock_bh(idx);
 964                 hlist_for_each_entry(cp, n, &ip_vs_conn_tab[idx], c_list) {
 965                         if (pos-- == 0) {
 966                                 iter->l = &ip_vs_conn_tab[idx];
 967                                 return cp;
 968                         }
 969                 }
 970                 ct_read_unlock_bh(idx);
 971         }
 972
 973         return NULL;
 974 }
 975
 976 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
 977 {
 978         struct ip_vs_iter_state *iter = seq->private;
 979
 980         iter->l = NULL;
 981         return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
 982 }
 983
 984 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 985 {
 986         struct ip_vs_conn *cp = v;
 987         struct ip_vs_iter_state *iter = seq->private;
 988         struct hlist_node *e;
 989         struct hlist_head *l = iter->l;
 990         int idx;
 991
 992         ++*pos;
 993         if (v == SEQ_START_TOKEN)
 994                 return ip_vs_conn_array(seq, 0);
 995
 996         /* more on same hash chain? */
 997         if ((e = cp->c_list.next))
 998                 return hlist_entry(e, struct ip_vs_conn, c_list);
 999
1000         idx = l - ip_vs_conn_tab;
1001         ct_read_unlock_bh(idx);
1002
1003         while (++idx < ip_vs_conn_tab_size) {
1004                 ct_read_lock_bh(idx);
1005                 hlist_for_each_entry(cp, e, &ip_vs_conn_tab[idx], c_list) {
1006                         iter->l = &ip_vs_conn_tab[idx];
1007                         return cp;
1008                 }
1009                 ct_read_unlock_bh(idx);
1010         }
1011         iter->l = NULL;
1012         return NULL;
1013 }
1014
1015 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1016 {
1017         struct ip_vs_iter_state *iter = seq->private;
1018         struct hlist_head *l = iter->l;
1019
1020         if (l)
1021                 ct_read_unlock_bh(l - ip_vs_conn_tab);
1022 }
1023
1024 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1025 {
1026
1027         if (v == SEQ_START_TOKEN)
1028                 seq_puts(seq,
1029    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires PEName PEData\n");
1030         else {
1031                 const struct ip_vs_conn *cp = v;
1032                 struct net *net = seq_file_net(seq);
1033                 char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1034                 size_t len = 0;
1035
1036                 if (!ip_vs_conn_net_eq(cp, net))
1037                         return 0;
1038                 if (cp->pe_data) {
1039                         pe_data[0] = ' ';
1040                         len = strlen(cp->pe->name);
1041                         memcpy(pe_data + 1, cp->pe->name, len);
1042                         pe_data[len + 1] = ' ';
1043                         len += 2;
1044                         len += cp->pe->show_pe_data(cp, pe_data + len);
1045                 }
1046                 pe_data[len] = '\0';
1047
1048 #ifdef CONFIG_IP_VS_IPV6
1049                 if (cp->af == AF_INET6)
1050                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1051                                 "%pI6 %04X %-11s %7lu%s\n",
1052                                 ip_vs_proto_name(cp->protocol),
1053                                 &cp->caddr.in6, ntohs(cp->cport),
1054                                 &cp->vaddr.in6, ntohs(cp->vport),
1055                                 &cp->daddr.in6, ntohs(cp->dport),
1056                                 ip_vs_state_name(cp->protocol, cp->state),
1057                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1058                 else
1059 #endif
1060                         seq_printf(seq,
1061                                 "%-3s %08X %04X %08X %04X"
1062                                 " %08X %04X %-11s %7lu%s\n",
1063                                 ip_vs_proto_name(cp->protocol),
1064                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1065                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1066                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
1067                                 ip_vs_state_name(cp->protocol, cp->state),
1068                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1069         }
1070         return 0;
1071 }
1072
1073 static const struct seq_operations ip_vs_conn_seq_ops = {
1074         .start = ip_vs_conn_seq_start,
1075         .next  = ip_vs_conn_seq_next,
1076         .stop  = ip_vs_conn_seq_stop,
1077         .show  = ip_vs_conn_seq_show,
1078 };
1079
1080 static int ip_vs_conn_open(struct inode *inode, struct file *file)
1081 {
1082         return seq_open_net(inode, file, &ip_vs_conn_seq_ops,
1083                             sizeof(struct ip_vs_iter_state));
1084 }
1085
1086 static const struct file_operations ip_vs_conn_fops = {
1087         .owner   = THIS_MODULE,
1088         .open    = ip_vs_conn_open,
1089         .read    = seq_read,
1090         .llseek  = seq_lseek,
1091         .release = seq_release_net,
1092 };
1093
1094 static const char *ip_vs_origin_name(unsigned int flags)
1095 {
1096         if (flags & IP_VS_CONN_F_SYNC)
1097                 return "SYNC";
1098         else
1099                 return "LOCAL";
1100 }
1101
1102 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1103 {
1104
1105         if (v == SEQ_START_TOKEN)
1106                 seq_puts(seq,
1107    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
1108         else {
1109                 const struct ip_vs_conn *cp = v;
1110                 struct net *net = seq_file_net(seq);
1111
1112                 if (!ip_vs_conn_net_eq(cp, net))
1113                         return 0;
1114
1115 #ifdef CONFIG_IP_VS_IPV6
1116                 if (cp->af == AF_INET6)
1117                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %-6s %7lu\n",
1118                                 ip_vs_proto_name(cp->protocol),
1119                                 &cp->caddr.in6, ntohs(cp->cport),
1120                                 &cp->vaddr.in6, ntohs(cp->vport),
1121                                 &cp->daddr.in6, ntohs(cp->dport),
1122                                 ip_vs_state_name(cp->protocol, cp->state),
1123                                 ip_vs_origin_name(cp->flags),
1124                                 (cp->timer.expires-jiffies)/HZ);
1125                 else
1126 #endif
1127                         seq_printf(seq,
1128                                 "%-3s %08X %04X %08X %04X "
1129                                 "%08X %04X %-11s %-6s %7lu\n",
1130                                 ip_vs_proto_name(cp->protocol),
1131                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1132                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1133                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
1134                                 ip_vs_state_name(cp->protocol, cp->state),
1135                                 ip_vs_origin_name(cp->flags),
1136                                 (cp->timer.expires-jiffies)/HZ);
1137         }
1138         return 0;
1139 }
1140
1141 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1142         .start = ip_vs_conn_seq_start,
1143         .next  = ip_vs_conn_seq_next,
1144         .stop  = ip_vs_conn_seq_stop,
1145         .show  = ip_vs_conn_sync_seq_show,
1146 };
1147
1148 static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
1149 {
1150         return seq_open_net(inode, file, &ip_vs_conn_sync_seq_ops,
1151                             sizeof(struct ip_vs_iter_state));
1152 }
1153
1154 static const struct file_operations ip_vs_conn_sync_fops = {
1155         .owner   = THIS_MODULE,
1156         .open    = ip_vs_conn_sync_open,
1157         .read    = seq_read,
1158         .llseek  = seq_lseek,
1159         .release = seq_release_net,
1160 };
1161
1162 #endif
1163
1164
1165 /*
1166  *      Randomly drop connection entries before running out of memory
1167  */
1168 static inline int todrop_entry(struct ip_vs_conn *cp)
1169 {
1170         /*
1171          * The drop rate array needs tuning for real environments.
1172          * Called from timer bh only => no locking
1173          */
1174         static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1175         static char todrop_counter[9] = {0};
1176         int i;
1177
1178         /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1179            This will leave enough time for normal connection to get
1180            through. */
1181         if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1182                 return 0;
1183
1184         /* Don't drop the entry if its number of incoming packets is not
1185            located in [0, 8] */
1186         i = atomic_read(&cp->in_pkts);
1187         if (i > 8 || i < 0) return 0;
1188
1189         if (!todrop_rate[i]) return 0;
1190         if (--todrop_counter[i] > 0) return 0;
1191
1192         todrop_counter[i] = todrop_rate[i];
1193         return 1;
1194 }
1195
1196 /* Called from keventd and must protect itself from softirqs */
1197 void ip_vs_random_dropentry(struct net *net)
1198 {
1199         int idx;
1200         struct ip_vs_conn *cp;
1201
1202         /*
1203          * Randomly scan 1/32 of the whole table every second
1204          */
1205         for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1206                 unsigned int hash = net_random() & ip_vs_conn_tab_mask;
1207                 struct hlist_node *n;
1208
1209                 /*
1210                  *  Lock is actually needed in this loop.
1211                  */
1212                 ct_write_lock_bh(hash);
1213
1214                 hlist_for_each_entry(cp, n, &ip_vs_conn_tab[hash], c_list) {
1215                         if (cp->flags & IP_VS_CONN_F_TEMPLATE)
1216                                 /* connection template */
1217                                 continue;
1218                         if (!ip_vs_conn_net_eq(cp, net))
1219                                 continue;
1220                         if (cp->protocol == IPPROTO_TCP) {
1221                                 switch(cp->state) {
1222                                 case IP_VS_TCP_S_SYN_RECV:
1223                                 case IP_VS_TCP_S_SYNACK:
1224                                         break;
1225
1226                                 case IP_VS_TCP_S_ESTABLISHED:
1227                                         if (todrop_entry(cp))
1228                                                 break;
1229                                         continue;
1230
1231                                 default:
1232                                         continue;
1233                                 }
1234                         } else {
1235                                 if (!todrop_entry(cp))
1236                                         continue;
1237                         }
1238
1239                         IP_VS_DBG(4, "del connection\n");
1240                         ip_vs_conn_expire_now(cp);
1241                         if (cp->control) {
1242                                 IP_VS_DBG(4, "del conn template\n");
1243                                 ip_vs_conn_expire_now(cp->control);
1244                         }
1245                 }
1246                 ct_write_unlock_bh(hash);
1247         }
1248 }
1249
1250
1251 /*
1252  *      Flush all the connection entries in the ip_vs_conn_tab
1253  */
1254 static void ip_vs_conn_flush(struct net *net)
1255 {
1256         int idx;
1257         struct ip_vs_conn *cp;
1258         struct netns_ipvs *ipvs = net_ipvs(net);
1259
1260 flush_again:
1261         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1262                 struct hlist_node *n;
1263
1264                 /*
1265                  *  Lock is actually needed in this loop.
1266                  */
1267                 ct_write_lock_bh(idx);
1268
1269                 hlist_for_each_entry(cp, n, &ip_vs_conn_tab[idx], c_list) {
1270                         if (!ip_vs_conn_net_eq(cp, net))
1271                                 continue;
1272                         IP_VS_DBG(4, "del connection\n");
1273                         ip_vs_conn_expire_now(cp);
1274                         if (cp->control) {
1275                                 IP_VS_DBG(4, "del conn template\n");
1276                                 ip_vs_conn_expire_now(cp->control);
1277                         }
1278                 }
1279                 ct_write_unlock_bh(idx);
1280         }
1281
1282         /* the counter may be not NULL, because maybe some conn entries
1283            are run by slow timer handler or unhashed but still referred */
1284         if (atomic_read(&ipvs->conn_count) != 0) {
1285                 schedule();
1286                 goto flush_again;
1287         }
1288 }
1289 /*
1290  * per netns init and exit
1291  */
1292 int __net_init ip_vs_conn_net_init(struct net *net)
1293 {
1294         struct netns_ipvs *ipvs = net_ipvs(net);
1295
1296         atomic_set(&ipvs->conn_count, 0);
1297
1298         proc_net_fops_create(net, "ip_vs_conn", 0, &ip_vs_conn_fops);
1299         proc_net_fops_create(net, "ip_vs_conn_sync", 0, &ip_vs_conn_sync_fops);
1300         return 0;
1301 }
1302
1303 void __net_exit ip_vs_conn_net_cleanup(struct net *net)
1304 {
1305         /* flush all the connection entries first */
1306         ip_vs_conn_flush(net);
1307         proc_net_remove(net, "ip_vs_conn");
1308         proc_net_remove(net, "ip_vs_conn_sync");
1309 }
1310
1311 int __init ip_vs_conn_init(void)
1312 {
1313         int idx;
1314
1315         /* Compute size and mask */
1316         ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1317         ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1318
1319         /*
1320          * Allocate the connection hash table and initialize its list heads
1321          */
1322         ip_vs_conn_tab = vmalloc(ip_vs_conn_tab_size * sizeof(*ip_vs_conn_tab));
1323         if (!ip_vs_conn_tab)
1324                 return -ENOMEM;
1325
1326         /* Allocate ip_vs_conn slab cache */
1327         ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1328                                               sizeof(struct ip_vs_conn), 0,
1329                                               SLAB_HWCACHE_ALIGN, NULL);
1330         if (!ip_vs_conn_cachep) {
1331                 vfree(ip_vs_conn_tab);
1332                 return -ENOMEM;
1333         }
1334
1335         pr_info("Connection hash table configured "
1336                 "(size=%d, memory=%ldKbytes)\n",
1337                 ip_vs_conn_tab_size,
1338                 (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
1339         IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
1340                   sizeof(struct ip_vs_conn));
1341
1342         for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1343                 INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1344
1345         for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1346                 rwlock_init(&__ip_vs_conntbl_lock_array[idx].l);
1347         }
1348
1349         /* calculate the random value for connection hash */
1350         get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1351
1352         return 0;
1353 }
1354
1355 void ip_vs_conn_cleanup(void)
1356 {
1357         /* Release the empty cache */
1358         kmem_cache_destroy(ip_vs_conn_cachep);
1359         vfree(ip_vs_conn_tab);
1360 }