net/netfilter/ipvs/ip_vs_conn.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * IPVS         An implementation of the IP virtual server support for the
   4  *              LINUX operating system.  IPVS is now implemented as a module
   5  *              over the Netfilter framework. IPVS can be used to build a
   6  *              high-performance and highly available server based on a
   7  *              cluster of servers.
   8  *
   9  * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
  10  *              Peter Kese <peter.kese@ijs.si>
  11  *              Julian Anastasov <ja@ssi.bg>
  12  *
  13  * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese,
  14  * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms
  15  * and others. Many code here is taken from IP MASQ code of kernel 2.2.
  16  *
  17  * Changes:
  18  */
  19
  20 #define KMSG_COMPONENT "IPVS"
  21 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  22
  23 #include <linux/interrupt.h>
  24 #include <linux/in.h>
  25 #include <linux/inet.h>
  26 #include <linux/net.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/vmalloc.h>
  30 #include <linux/proc_fs.h>              /* for proc_net_* */
  31 #include <linux/slab.h>
  32 #include <linux/seq_file.h>
  33 #include <linux/jhash.h>
  34 #include <linux/random.h>
  35
  36 #include <net/net_namespace.h>
  37 #include <net/ip_vs.h>
  38
  39
  40 #ifndef CONFIG_IP_VS_TAB_BITS
  41 #define CONFIG_IP_VS_TAB_BITS   12
  42 #endif
  43
  44 /*
  45  * Connection hash size. Default is what was selected at compile time.
  46 */
  47 static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
  48 module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
  49 MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
  50
  51 /* size and mask values */
  52 int ip_vs_conn_tab_size __read_mostly;
  53 static int ip_vs_conn_tab_mask __read_mostly;
  54
  55 /*
  56  *  Connection hash table: for input and output packets lookups of IPVS
  57  */
  58 static struct hlist_head *ip_vs_conn_tab __read_mostly;
  59
  60 /*  SLAB cache for IPVS connections */
  61 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
  62
  63 /*  counter for no client port connections */
  64 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
  65
  66 /* random value for IPVS connection hash */
  67 static unsigned int ip_vs_conn_rnd __read_mostly;
  68
  69 /*
  70  *  Fine locking granularity for big connection hash table
  71  */
  72 #define CT_LOCKARRAY_BITS  5
  73 #define CT_LOCKARRAY_SIZE  (1<<CT_LOCKARRAY_BITS)
  74 #define CT_LOCKARRAY_MASK  (CT_LOCKARRAY_SIZE-1)
  75
  76 /* We need an addrstrlen that works with or without v6 */
  77 #ifdef CONFIG_IP_VS_IPV6
  78 #define IP_VS_ADDRSTRLEN INET6_ADDRSTRLEN
  79 #else
  80 #define IP_VS_ADDRSTRLEN (8+1)
  81 #endif
  82
  83 struct ip_vs_aligned_lock
  84 {
  85         spinlock_t      l;
  86 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
  87
  88 /* lock array for conn table */
  89 static struct ip_vs_aligned_lock
  90 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
  91
  92 static inline void ct_write_lock_bh(unsigned int key)
  93 {
  94         spin_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  95 }
  96
  97 static inline void ct_write_unlock_bh(unsigned int key)
  98 {
  99         spin_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 100 }
 101
 102 static void ip_vs_conn_expire(struct timer_list *t);
 103
 104 /*
 105  *      Returns hash value for IPVS connection entry
 106  */
 107 static unsigned int ip_vs_conn_hashkey(struct netns_ipvs *ipvs, int af, unsigned int proto,
 108                                        const union nf_inet_addr *addr,
 109                                        __be16 port)
 110 {
 111 #ifdef CONFIG_IP_VS_IPV6
 112         if (af == AF_INET6)
 113                 return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
 114                                     (__force u32)port, proto, ip_vs_conn_rnd) ^
 115                         ((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
 116 #endif
 117         return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
 118                             ip_vs_conn_rnd) ^
 119                 ((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
 120 }
 121
 122 static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p,
 123                                              bool inverse)
 124 {
 125         const union nf_inet_addr *addr;
 126         __be16 port;
 127
 128         if (p->pe_data && p->pe->hashkey_raw)
 129                 return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) &
 130                         ip_vs_conn_tab_mask;
 131
 132         if (likely(!inverse)) {
 133                 addr = p->caddr;
 134                 port = p->cport;
 135         } else {
 136                 addr = p->vaddr;
 137                 port = p->vport;
 138         }
 139
 140         return ip_vs_conn_hashkey(p->ipvs, p->af, p->protocol, addr, port);
 141 }
 142
 143 static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp)
 144 {
 145         struct ip_vs_conn_param p;
 146
 147         ip_vs_conn_fill_param(cp->ipvs, cp->af, cp->protocol,
 148                               &cp->caddr, cp->cport, NULL, 0, &p);
 149
 150         if (cp->pe) {
 151                 p.pe = cp->pe;
 152                 p.pe_data = cp->pe_data;
 153                 p.pe_data_len = cp->pe_data_len;
 154         }
 155
 156         return ip_vs_conn_hashkey_param(&p, false);
 157 }
 158
 159 /*
 160  *      Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port.
 161  *      returns bool success.
 162  */
 163 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
 164 {
 165         unsigned int hash;
 166         int ret;
 167
 168         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 169                 return 0;
 170
 171         /* Hash by protocol, client address and port */
 172         hash = ip_vs_conn_hashkey_conn(cp);
 173
 174         ct_write_lock_bh(hash);
 175         spin_lock(&cp->lock);
 176
 177         if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
 178                 cp->flags |= IP_VS_CONN_F_HASHED;
 179                 refcount_inc(&cp->refcnt);
 180                 hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]);
 181                 ret = 1;
 182         } else {
 183                 pr_err("%s(): request for already hashed, called from %pS\n",
 184                        __func__, __builtin_return_address(0));
 185                 ret = 0;
 186         }
 187
 188         spin_unlock(&cp->lock);
 189         ct_write_unlock_bh(hash);
 190
 191         return ret;
 192 }
 193
 194
 195 /*
 196  *      UNhashes ip_vs_conn from ip_vs_conn_tab.
 197  *      returns bool success. Caller should hold conn reference.
 198  */
 199 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
 200 {
 201         unsigned int hash;
 202         int ret;
 203
 204         /* unhash it and decrease its reference counter */
 205         hash = ip_vs_conn_hashkey_conn(cp);
 206
 207         ct_write_lock_bh(hash);
 208         spin_lock(&cp->lock);
 209
 210         if (cp->flags & IP_VS_CONN_F_HASHED) {
 211                 hlist_del_rcu(&cp->c_list);
 212                 cp->flags &= ~IP_VS_CONN_F_HASHED;
 213                 refcount_dec(&cp->refcnt);
 214                 ret = 1;
 215         } else
 216                 ret = 0;
 217
 218         spin_unlock(&cp->lock);
 219         ct_write_unlock_bh(hash);
 220
 221         return ret;
 222 }
 223
 224 /* Try to unlink ip_vs_conn from ip_vs_conn_tab.
 225  * returns bool success.
 226  */
 227 static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp)
 228 {
 229         unsigned int hash;
 230         bool ret = false;
 231
 232         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 233                 return refcount_dec_if_one(&cp->refcnt);
 234
 235         hash = ip_vs_conn_hashkey_conn(cp);
 236
 237         ct_write_lock_bh(hash);
 238         spin_lock(&cp->lock);
 239
 240         if (cp->flags & IP_VS_CONN_F_HASHED) {
 241                 /* Decrease refcnt and unlink conn only if we are last user */
 242                 if (refcount_dec_if_one(&cp->refcnt)) {
 243                         hlist_del_rcu(&cp->c_list);
 244                         cp->flags &= ~IP_VS_CONN_F_HASHED;
 245                         ret = true;
 246                 }
 247         }
 248
 249         spin_unlock(&cp->lock);
 250         ct_write_unlock_bh(hash);
 251
 252         return ret;
 253 }
 254
 255
 256 /*
 257  *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 258  *  Called for pkts coming from OUTside-to-INside.
 259  *      p->caddr, p->cport: pkt source address (foreign host)
 260  *      p->vaddr, p->vport: pkt dest address (load balancer)
 261  */
 262 static inline struct ip_vs_conn *
 263 __ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
 264 {
 265         unsigned int hash;
 266         struct ip_vs_conn *cp;
 267
 268         hash = ip_vs_conn_hashkey_param(p, false);
 269
 270         rcu_read_lock();
 271
 272         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 273                 if (p->cport == cp->cport && p->vport == cp->vport &&
 274                     cp->af == p->af &&
 275                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 276                     ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) &&
 277                     ((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
 278                     p->protocol == cp->protocol &&
 279                     cp->ipvs == p->ipvs) {
 280                         if (!__ip_vs_conn_get(cp))
 281                                 continue;
 282                         /* HIT */
 283                         rcu_read_unlock();
 284                         return cp;
 285                 }
 286         }
 287
 288         rcu_read_unlock();
 289
 290         return NULL;
 291 }
 292
 293 struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
 294 {
 295         struct ip_vs_conn *cp;
 296
 297         cp = __ip_vs_conn_in_get(p);
 298         if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) {
 299                 struct ip_vs_conn_param cport_zero_p = *p;
 300                 cport_zero_p.cport = 0;
 301                 cp = __ip_vs_conn_in_get(&cport_zero_p);
 302         }
 303
 304         IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
 305                       ip_vs_proto_name(p->protocol),
 306                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 307                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 308                       cp ? "hit" : "not hit");
 309
 310         return cp;
 311 }
 312
 313 static int
 314 ip_vs_conn_fill_param_proto(struct netns_ipvs *ipvs,
 315                             int af, const struct sk_buff *skb,
 316                             const struct ip_vs_iphdr *iph,
 317                             struct ip_vs_conn_param *p)
 318 {
 319         __be16 _ports[2], *pptr;
 320
 321         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports);
 322         if (pptr == NULL)
 323                 return 1;
 324
 325         if (likely(!ip_vs_iph_inverse(iph)))
 326                 ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->saddr,
 327                                       pptr[0], &iph->daddr, pptr[1], p);
 328         else
 329                 ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->daddr,
 330                                       pptr[1], &iph->saddr, pptr[0], p);
 331         return 0;
 332 }
 333
 334 struct ip_vs_conn *
 335 ip_vs_conn_in_get_proto(struct netns_ipvs *ipvs, int af,
 336                         const struct sk_buff *skb,
 337                         const struct ip_vs_iphdr *iph)
 338 {
 339         struct ip_vs_conn_param p;
 340
 341         if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
 342                 return NULL;
 343
 344         return ip_vs_conn_in_get(&p);
 345 }
 346 EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
 347
 348 /* Get reference to connection template */
 349 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
 350 {
 351         unsigned int hash;
 352         struct ip_vs_conn *cp;
 353
 354         hash = ip_vs_conn_hashkey_param(p, false);
 355
 356         rcu_read_lock();
 357
 358         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 359                 if (unlikely(p->pe_data && p->pe->ct_match)) {
 360                         if (cp->ipvs != p->ipvs)
 361                                 continue;
 362                         if (p->pe == cp->pe && p->pe->ct_match(p, cp)) {
 363                                 if (__ip_vs_conn_get(cp))
 364                                         goto out;
 365                         }
 366                         continue;
 367                 }
 368
 369                 if (cp->af == p->af &&
 370                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 371                     /* protocol should only be IPPROTO_IP if
 372                      * p->vaddr is a fwmark */
 373                     ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
 374                                      p->af, p->vaddr, &cp->vaddr) &&
 375                     p->vport == cp->vport && p->cport == cp->cport &&
 376                     cp->flags & IP_VS_CONN_F_TEMPLATE &&
 377                     p->protocol == cp->protocol &&
 378                     cp->ipvs == p->ipvs) {
 379                         if (__ip_vs_conn_get(cp))
 380                                 goto out;
 381                 }
 382         }
 383         cp = NULL;
 384
 385   out:
 386         rcu_read_unlock();
 387
 388         IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
 389                       ip_vs_proto_name(p->protocol),
 390                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 391                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 392                       cp ? "hit" : "not hit");
 393
 394         return cp;
 395 }
 396
 397 /* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 398  * Called for pkts coming from inside-to-OUTside.
 399  *      p->caddr, p->cport: pkt source address (inside host)
 400  *      p->vaddr, p->vport: pkt dest address (foreign host) */
 401 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
 402 {
 403         unsigned int hash;
 404         struct ip_vs_conn *cp, *ret=NULL;
 405
 406         /*
 407          *      Check for "full" addressed entries
 408          */
 409         hash = ip_vs_conn_hashkey_param(p, true);
 410
 411         rcu_read_lock();
 412
 413         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 414                 if (p->vport == cp->cport && p->cport == cp->dport &&
 415                     cp->af == p->af &&
 416                     ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
 417                     ip_vs_addr_equal(p->af, p->caddr, &cp->daddr) &&
 418                     p->protocol == cp->protocol &&
 419                     cp->ipvs == p->ipvs) {
 420                         if (!__ip_vs_conn_get(cp))
 421                                 continue;
 422                         /* HIT */
 423                         ret = cp;
 424                         break;
 425                 }
 426         }
 427
 428         rcu_read_unlock();
 429
 430         IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
 431                       ip_vs_proto_name(p->protocol),
 432                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 433                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 434                       ret ? "hit" : "not hit");
 435
 436         return ret;
 437 }
 438
 439 struct ip_vs_conn *
 440 ip_vs_conn_out_get_proto(struct netns_ipvs *ipvs, int af,
 441                          const struct sk_buff *skb,
 442                          const struct ip_vs_iphdr *iph)
 443 {
 444         struct ip_vs_conn_param p;
 445
 446         if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
 447                 return NULL;
 448
 449         return ip_vs_conn_out_get(&p);
 450 }
 451 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
 452
 453 /*
 454  *      Put back the conn and restart its timer with its timeout
 455  */
 456 static void __ip_vs_conn_put_timer(struct ip_vs_conn *cp)
 457 {
 458         unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
 459                 0 : cp->timeout;
 460         mod_timer(&cp->timer, jiffies+t);
 461
 462         __ip_vs_conn_put(cp);
 463 }
 464
 465 void ip_vs_conn_put(struct ip_vs_conn *cp)
 466 {
 467         if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) &&
 468             (refcount_read(&cp->refcnt) == 1) &&
 469             !timer_pending(&cp->timer))
 470                 /* expire connection immediately */
 471                 ip_vs_conn_expire(&cp->timer);
 472         else
 473                 __ip_vs_conn_put_timer(cp);
 474 }
 475
 476 /*
 477  *      Fill a no_client_port connection with a client port number
 478  */
 479 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
 480 {
 481         if (ip_vs_conn_unhash(cp)) {
 482                 spin_lock_bh(&cp->lock);
 483                 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
 484                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 485                         cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
 486                         cp->cport = cport;
 487                 }
 488                 spin_unlock_bh(&cp->lock);
 489
 490                 /* hash on new dport */
 491                 ip_vs_conn_hash(cp);
 492         }
 493 }
 494
 495
 496 /*
 497  *      Bind a connection entry with the corresponding packet_xmit.
 498  *      Called by ip_vs_conn_new.
 499  */
 500 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
 501 {
 502         switch (IP_VS_FWD_METHOD(cp)) {
 503         case IP_VS_CONN_F_MASQ:
 504                 cp->packet_xmit = ip_vs_nat_xmit;
 505                 break;
 506
 507         case IP_VS_CONN_F_TUNNEL:
 508 #ifdef CONFIG_IP_VS_IPV6
 509                 if (cp->daf == AF_INET6)
 510                         cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 511                 else
 512 #endif
 513                         cp->packet_xmit = ip_vs_tunnel_xmit;
 514                 break;
 515
 516         case IP_VS_CONN_F_DROUTE:
 517                 cp->packet_xmit = ip_vs_dr_xmit;
 518                 break;
 519
 520         case IP_VS_CONN_F_LOCALNODE:
 521                 cp->packet_xmit = ip_vs_null_xmit;
 522                 break;
 523
 524         case IP_VS_CONN_F_BYPASS:
 525                 cp->packet_xmit = ip_vs_bypass_xmit;
 526                 break;
 527         }
 528 }
 529
 530 #ifdef CONFIG_IP_VS_IPV6
 531 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
 532 {
 533         switch (IP_VS_FWD_METHOD(cp)) {
 534         case IP_VS_CONN_F_MASQ:
 535                 cp->packet_xmit = ip_vs_nat_xmit_v6;
 536                 break;
 537
 538         case IP_VS_CONN_F_TUNNEL:
 539                 if (cp->daf == AF_INET6)
 540                         cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 541                 else
 542                         cp->packet_xmit = ip_vs_tunnel_xmit;
 543                 break;
 544
 545         case IP_VS_CONN_F_DROUTE:
 546                 cp->packet_xmit = ip_vs_dr_xmit_v6;
 547                 break;
 548
 549         case IP_VS_CONN_F_LOCALNODE:
 550                 cp->packet_xmit = ip_vs_null_xmit;
 551                 break;
 552
 553         case IP_VS_CONN_F_BYPASS:
 554                 cp->packet_xmit = ip_vs_bypass_xmit_v6;
 555                 break;
 556         }
 557 }
 558 #endif
 559
 560
 561 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
 562 {
 563         return atomic_read(&dest->activeconns)
 564                 + atomic_read(&dest->inactconns);
 565 }
 566
 567 /*
 568  *      Bind a connection entry with a virtual service destination
 569  *      Called just after a new connection entry is created.
 570  */
 571 static inline void
 572 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
 573 {
 574         unsigned int conn_flags;
 575         __u32 flags;
 576
 577         /* if dest is NULL, then return directly */
 578         if (!dest)
 579                 return;
 580
 581         /* Increase the refcnt counter of the dest */
 582         ip_vs_dest_hold(dest);
 583
 584         conn_flags = atomic_read(&dest->conn_flags);
 585         if (cp->protocol != IPPROTO_UDP)
 586                 conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
 587         flags = cp->flags;
 588         /* Bind with the destination and its corresponding transmitter */
 589         if (flags & IP_VS_CONN_F_SYNC) {
 590                 /* if the connection is not template and is created
 591                  * by sync, preserve the activity flag.
 592                  */
 593                 if (!(flags & IP_VS_CONN_F_TEMPLATE))
 594                         conn_flags &= ~IP_VS_CONN_F_INACTIVE;
 595                 /* connections inherit forwarding method from dest */
 596                 flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
 597         }
 598         flags |= conn_flags;
 599         cp->flags = flags;
 600         cp->dest = dest;
 601
 602         IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
 603                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 604                       "dest->refcnt:%d\n",
 605                       ip_vs_proto_name(cp->protocol),
 606                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 607                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 608                       IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
 609                       ip_vs_fwd_tag(cp), cp->state,
 610                       cp->flags, refcount_read(&cp->refcnt),
 611                       refcount_read(&dest->refcnt));
 612
 613         /* Update the connection counters */
 614         if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
 615                 /* It is a normal connection, so modify the counters
 616                  * according to the flags, later the protocol can
 617                  * update them on state change
 618                  */
 619                 if (!(flags & IP_VS_CONN_F_INACTIVE))
 620                         atomic_inc(&dest->activeconns);
 621                 else
 622                         atomic_inc(&dest->inactconns);
 623         } else {
 624                 /* It is a persistent connection/template, so increase
 625                    the persistent connection counter */
 626                 atomic_inc(&dest->persistconns);
 627         }
 628
 629         if (dest->u_threshold != 0 &&
 630             ip_vs_dest_totalconns(dest) >= dest->u_threshold)
 631                 dest->flags |= IP_VS_DEST_F_OVERLOAD;
 632 }
 633
 634
 635 /*
 636  * Check if there is a destination for the connection, if so
 637  * bind the connection to the destination.
 638  */
 639 void ip_vs_try_bind_dest(struct ip_vs_conn *cp)
 640 {
 641         struct ip_vs_dest *dest;
 642
 643         rcu_read_lock();
 644
 645         /* This function is only invoked by the synchronization code. We do
 646          * not currently support heterogeneous pools with synchronization,
 647          * so we can make the assumption that the svc_af is the same as the
 648          * dest_af
 649          */
 650         dest = ip_vs_find_dest(cp->ipvs, cp->af, cp->af, &cp->daddr,
 651                                cp->dport, &cp->vaddr, cp->vport,
 652                                cp->protocol, cp->fwmark, cp->flags);
 653         if (dest) {
 654                 struct ip_vs_proto_data *pd;
 655
 656                 spin_lock_bh(&cp->lock);
 657                 if (cp->dest) {
 658                         spin_unlock_bh(&cp->lock);
 659                         rcu_read_unlock();
 660                         return;
 661                 }
 662
 663                 /* Applications work depending on the forwarding method
 664                  * but better to reassign them always when binding dest */
 665                 if (cp->app)
 666                         ip_vs_unbind_app(cp);
 667
 668                 ip_vs_bind_dest(cp, dest);
 669                 spin_unlock_bh(&cp->lock);
 670
 671                 /* Update its packet transmitter */
 672                 cp->packet_xmit = NULL;
 673 #ifdef CONFIG_IP_VS_IPV6
 674                 if (cp->af == AF_INET6)
 675                         ip_vs_bind_xmit_v6(cp);
 676                 else
 677 #endif
 678                         ip_vs_bind_xmit(cp);
 679
 680                 pd = ip_vs_proto_data_get(cp->ipvs, cp->protocol);
 681                 if (pd && atomic_read(&pd->appcnt))
 682                         ip_vs_bind_app(cp, pd->pp);
 683         }
 684         rcu_read_unlock();
 685 }
 686
 687
 688 /*
 689  *      Unbind a connection entry with its VS destination
 690  *      Called by the ip_vs_conn_expire function.
 691  */
 692 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
 693 {
 694         struct ip_vs_dest *dest = cp->dest;
 695
 696         if (!dest)
 697                 return;
 698
 699         IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
 700                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 701                       "dest->refcnt:%d\n",
 702                       ip_vs_proto_name(cp->protocol),
 703                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 704                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 705                       IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
 706                       ip_vs_fwd_tag(cp), cp->state,
 707                       cp->flags, refcount_read(&cp->refcnt),
 708                       refcount_read(&dest->refcnt));
 709
 710         /* Update the connection counters */
 711         if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
 712                 /* It is a normal connection, so decrease the inactconns
 713                    or activeconns counter */
 714                 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
 715                         atomic_dec(&dest->inactconns);
 716                 } else {
 717                         atomic_dec(&dest->activeconns);
 718                 }
 719         } else {
 720                 /* It is a persistent connection/template, so decrease
 721                    the persistent connection counter */
 722                 atomic_dec(&dest->persistconns);
 723         }
 724
 725         if (dest->l_threshold != 0) {
 726                 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
 727                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 728         } else if (dest->u_threshold != 0) {
 729                 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
 730                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 731         } else {
 732                 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 733                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 734         }
 735
 736         ip_vs_dest_put(dest);
 737 }
 738
 739 static int expire_quiescent_template(struct netns_ipvs *ipvs,
 740                                      struct ip_vs_dest *dest)
 741 {
 742 #ifdef CONFIG_SYSCTL
 743         return ipvs->sysctl_expire_quiescent_template &&
 744                 (atomic_read(&dest->weight) == 0);
 745 #else
 746         return 0;
 747 #endif
 748 }
 749
 750 /*
 751  *      Checking if the destination of a connection template is available.
 752  *      If available, return 1, otherwise invalidate this connection
 753  *      template and return 0.
 754  */
 755 int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest)
 756 {
 757         struct ip_vs_dest *dest = ct->dest;
 758         struct netns_ipvs *ipvs = ct->ipvs;
 759
 760         /*
 761          * Checking the dest server status.
 762          */
 763         if ((dest == NULL) ||
 764             !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
 765             expire_quiescent_template(ipvs, dest) ||
 766             (cdest && (dest != cdest))) {
 767                 IP_VS_DBG_BUF(9, "check_template: dest not available for "
 768                               "protocol %s s:%s:%d v:%s:%d "
 769                               "-> d:%s:%d\n",
 770                               ip_vs_proto_name(ct->protocol),
 771                               IP_VS_DBG_ADDR(ct->af, &ct->caddr),
 772                               ntohs(ct->cport),
 773                               IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
 774                               ntohs(ct->vport),
 775                               IP_VS_DBG_ADDR(ct->daf, &ct->daddr),
 776                               ntohs(ct->dport));
 777
 778                 /*
 779                  * Invalidate the connection template
 780                  */
 781                 if (ct->vport != htons(0xffff)) {
 782                         if (ip_vs_conn_unhash(ct)) {
 783                                 ct->dport = htons(0xffff);
 784                                 ct->vport = htons(0xffff);
 785                                 ct->cport = 0;
 786                                 ip_vs_conn_hash(ct);
 787                         }
 788                 }
 789
 790                 /*
 791                  * Simply decrease the refcnt of the template,
 792                  * don't restart its timer.
 793                  */
 794                 __ip_vs_conn_put(ct);
 795                 return 0;
 796         }
 797         return 1;
 798 }
 799
 800 static void ip_vs_conn_rcu_free(struct rcu_head *head)
 801 {
 802         struct ip_vs_conn *cp = container_of(head, struct ip_vs_conn,
 803                                              rcu_head);
 804
 805         ip_vs_pe_put(cp->pe);
 806         kfree(cp->pe_data);
 807         kmem_cache_free(ip_vs_conn_cachep, cp);
 808 }
 809
 810 static void ip_vs_conn_expire(struct timer_list *t)
 811 {
 812         struct ip_vs_conn *cp = from_timer(cp, t, timer);
 813         struct netns_ipvs *ipvs = cp->ipvs;
 814
 815         /*
 816          *      do I control anybody?
 817          */
 818         if (atomic_read(&cp->n_control))
 819                 goto expire_later;
 820
 821         /* Unlink conn if not referenced anymore */
 822         if (likely(ip_vs_conn_unlink(cp))) {
 823                 struct ip_vs_conn *ct = cp->control;
 824
 825                 /* delete the timer if it is activated by other users */
 826                 del_timer(&cp->timer);
 827
 828                 /* does anybody control me? */
 829                 if (ct) {
 830                         ip_vs_control_del(cp);
 831                         /* Drop CTL or non-assured TPL if not used anymore */
 832                         if (!cp->timeout && !atomic_read(&ct->n_control) &&
 833                             (!(ct->flags & IP_VS_CONN_F_TEMPLATE) ||
 834                              !(ct->state & IP_VS_CTPL_S_ASSURED))) {
 835                                 IP_VS_DBG(4, "drop controlling connection\n");
 836                                 ct->timeout = 0;
 837                                 ip_vs_conn_expire_now(ct);
 838                         }
 839                 }
 840
 841                 if ((cp->flags & IP_VS_CONN_F_NFCT) &&
 842                     !(cp->flags & IP_VS_CONN_F_ONE_PACKET)) {
 843                         /* Do not access conntracks during subsys cleanup
 844                          * because nf_conntrack_find_get can not be used after
 845                          * conntrack cleanup for the net.
 846                          */
 847                         smp_rmb();
 848                         if (ipvs->enable)
 849                                 ip_vs_conn_drop_conntrack(cp);
 850                 }
 851
 852                 if (unlikely(cp->app != NULL))
 853                         ip_vs_unbind_app(cp);
 854                 ip_vs_unbind_dest(cp);
 855                 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
 856                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 857                 if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 858                         ip_vs_conn_rcu_free(&cp->rcu_head);
 859                 else
 860                         call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
 861                 atomic_dec(&ipvs->conn_count);
 862                 return;
 863         }
 864
 865   expire_later:
 866         IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
 867                   refcount_read(&cp->refcnt),
 868                   atomic_read(&cp->n_control));
 869
 870         refcount_inc(&cp->refcnt);
 871         cp->timeout = 60*HZ;
 872
 873         if (ipvs->sync_state & IP_VS_STATE_MASTER)
 874                 ip_vs_sync_conn(ipvs, cp, sysctl_sync_threshold(ipvs));
 875
 876         __ip_vs_conn_put_timer(cp);
 877 }
 878
 879 /* Modify timer, so that it expires as soon as possible.
 880  * Can be called without reference only if under RCU lock.
 881  * We can have such chain of conns linked with ->control: DATA->CTL->TPL
 882  * - DATA (eg. FTP) and TPL (persistence) can be present depending on setup
 883  * - cp->timeout=0 indicates all conns from chain should be dropped but
 884  * TPL is not dropped if in assured state
 885  */
 886 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
 887 {
 888         /* Using mod_timer_pending will ensure the timer is not
 889          * modified after the final del_timer in ip_vs_conn_expire.
 890          */
 891         if (timer_pending(&cp->timer) &&
 892             time_after(cp->timer.expires, jiffies))
 893                 mod_timer_pending(&cp->timer, jiffies);
 894 }
 895
 896
 897 /*
 898  *      Create a new connection entry and hash it into the ip_vs_conn_tab
 899  */
 900 struct ip_vs_conn *
 901 ip_vs_conn_new(const struct ip_vs_conn_param *p, int dest_af,
 902                const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
 903                struct ip_vs_dest *dest, __u32 fwmark)
 904 {
 905         struct ip_vs_conn *cp;
 906         struct netns_ipvs *ipvs = p->ipvs;
 907         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->ipvs,
 908                                                            p->protocol);
 909
 910         cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
 911         if (cp == NULL) {
 912                 IP_VS_ERR_RL("%s(): no memory\n", __func__);
 913                 return NULL;
 914         }
 915
 916         INIT_HLIST_NODE(&cp->c_list);
 917         timer_setup(&cp->timer, ip_vs_conn_expire, 0);
 918         cp->ipvs           = ipvs;
 919         cp->af             = p->af;
 920         cp->daf            = dest_af;
 921         cp->protocol       = p->protocol;
 922         ip_vs_addr_set(p->af, &cp->caddr, p->caddr);
 923         cp->cport          = p->cport;
 924         /* proto should only be IPPROTO_IP if p->vaddr is a fwmark */
 925         ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
 926                        &cp->vaddr, p->vaddr);
 927         cp->vport          = p->vport;
 928         ip_vs_addr_set(cp->daf, &cp->daddr, daddr);
 929         cp->dport          = dport;
 930         cp->flags          = flags;
 931         cp->fwmark         = fwmark;
 932         if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
 933                 ip_vs_pe_get(p->pe);
 934                 cp->pe = p->pe;
 935                 cp->pe_data = p->pe_data;
 936                 cp->pe_data_len = p->pe_data_len;
 937         } else {
 938                 cp->pe = NULL;
 939                 cp->pe_data = NULL;
 940                 cp->pe_data_len = 0;
 941         }
 942         spin_lock_init(&cp->lock);
 943
 944         /*
 945          * Set the entry is referenced by the current thread before hashing
 946          * it in the table, so that other thread run ip_vs_random_dropentry
 947          * but cannot drop this entry.
 948          */
 949         refcount_set(&cp->refcnt, 1);
 950
 951         cp->control = NULL;
 952         atomic_set(&cp->n_control, 0);
 953         atomic_set(&cp->in_pkts, 0);
 954
 955         cp->packet_xmit = NULL;
 956         cp->app = NULL;
 957         cp->app_data = NULL;
 958         /* reset struct ip_vs_seq */
 959         cp->in_seq.delta = 0;
 960         cp->out_seq.delta = 0;
 961
 962         atomic_inc(&ipvs->conn_count);
 963         if (flags & IP_VS_CONN_F_NO_CPORT)
 964                 atomic_inc(&ip_vs_conn_no_cport_cnt);
 965
 966         /* Bind the connection with a destination server */
 967         cp->dest = NULL;
 968         ip_vs_bind_dest(cp, dest);
 969
 970         /* Set its state and timeout */
 971         cp->state = 0;
 972         cp->old_state = 0;
 973         cp->timeout = 3*HZ;
 974         cp->sync_endtime = jiffies & ~3UL;
 975
 976         /* Bind its packet transmitter */
 977 #ifdef CONFIG_IP_VS_IPV6
 978         if (p->af == AF_INET6)
 979                 ip_vs_bind_xmit_v6(cp);
 980         else
 981 #endif
 982                 ip_vs_bind_xmit(cp);
 983
 984         if (unlikely(pd && atomic_read(&pd->appcnt)))
 985                 ip_vs_bind_app(cp, pd->pp);
 986
 987         /*
 988          * Allow conntrack to be preserved. By default, conntrack
 989          * is created and destroyed for every packet.
 990          * Sometimes keeping conntrack can be useful for
 991          * IP_VS_CONN_F_ONE_PACKET too.
 992          */
 993
 994         if (ip_vs_conntrack_enabled(ipvs))
 995                 cp->flags |= IP_VS_CONN_F_NFCT;
 996
 997         /* Hash it in the ip_vs_conn_tab finally */
 998         ip_vs_conn_hash(cp);
 999
1000         return cp;
1001 }
1002
1003 /*
1004  *      /proc/net/ip_vs_conn entries
1005  */
1006 #ifdef CONFIG_PROC_FS
1007 struct ip_vs_iter_state {
1008         struct seq_net_private  p;
1009         struct hlist_head       *l;
1010 };
1011
1012 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
1013 {
1014         int idx;
1015         struct ip_vs_conn *cp;
1016         struct ip_vs_iter_state *iter = seq->private;
1017
1018         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1019                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1020                         /* __ip_vs_conn_get() is not needed by
1021                          * ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show
1022                          */
1023                         if (pos-- == 0) {
1024                                 iter->l = &ip_vs_conn_tab[idx];
1025                                 return cp;
1026                         }
1027                 }
1028                 cond_resched_rcu();
1029         }
1030
1031         return NULL;
1032 }
1033
1034 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
1035         __acquires(RCU)
1036 {
1037         struct ip_vs_iter_state *iter = seq->private;
1038
1039         iter->l = NULL;
1040         rcu_read_lock();
1041         return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
1042 }
1043
1044 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1045 {
1046         struct ip_vs_conn *cp = v;
1047         struct ip_vs_iter_state *iter = seq->private;
1048         struct hlist_node *e;
1049         struct hlist_head *l = iter->l;
1050         int idx;
1051
1052         ++*pos;
1053         if (v == SEQ_START_TOKEN)
1054                 return ip_vs_conn_array(seq, 0);
1055
1056         /* more on same hash chain? */
1057         e = rcu_dereference(hlist_next_rcu(&cp->c_list));
1058         if (e)
1059                 return hlist_entry(e, struct ip_vs_conn, c_list);
1060
1061         idx = l - ip_vs_conn_tab;
1062         while (++idx < ip_vs_conn_tab_size) {
1063                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1064                         iter->l = &ip_vs_conn_tab[idx];
1065                         return cp;
1066                 }
1067                 cond_resched_rcu();
1068         }
1069         iter->l = NULL;
1070         return NULL;
1071 }
1072
1073 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1074         __releases(RCU)
1075 {
1076         rcu_read_unlock();
1077 }
1078
1079 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1080 {
1081
1082         if (v == SEQ_START_TOKEN)
1083                 seq_puts(seq,
1084    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires PEName PEData\n");
1085         else {
1086                 const struct ip_vs_conn *cp = v;
1087                 struct net *net = seq_file_net(seq);
1088                 char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1089                 size_t len = 0;
1090                 char dbuf[IP_VS_ADDRSTRLEN];
1091
1092                 if (!net_eq(cp->ipvs->net, net))
1093                         return 0;
1094                 if (cp->pe_data) {
1095                         pe_data[0] = ' ';
1096                         len = strlen(cp->pe->name);
1097                         memcpy(pe_data + 1, cp->pe->name, len);
1098                         pe_data[len + 1] = ' ';
1099                         len += 2;
1100                         len += cp->pe->show_pe_data(cp, pe_data + len);
1101                 }
1102                 pe_data[len] = '\0';
1103
1104 #ifdef CONFIG_IP_VS_IPV6
1105                 if (cp->daf == AF_INET6)
1106                         snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1107                 else
1108 #endif
1109                         snprintf(dbuf, sizeof(dbuf), "%08X",
1110                                  ntohl(cp->daddr.ip));
1111
1112 #ifdef CONFIG_IP_VS_IPV6
1113                 if (cp->af == AF_INET6)
1114                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1115                                 "%s %04X %-11s %7u%s\n",
1116                                 ip_vs_proto_name(cp->protocol),
1117                                 &cp->caddr.in6, ntohs(cp->cport),
1118                                 &cp->vaddr.in6, ntohs(cp->vport),
1119                                 dbuf, ntohs(cp->dport),
1120                                 ip_vs_state_name(cp),
1121                                 jiffies_delta_to_msecs(cp->timer.expires -
1122                                                        jiffies) / 1000,
1123                                 pe_data);
1124                 else
1125 #endif
1126                         seq_printf(seq,
1127                                 "%-3s %08X %04X %08X %04X"
1128                                 " %s %04X %-11s %7u%s\n",
1129                                 ip_vs_proto_name(cp->protocol),
1130                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1131                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1132                                 dbuf, ntohs(cp->dport),
1133                                 ip_vs_state_name(cp),
1134                                 jiffies_delta_to_msecs(cp->timer.expires -
1135                                                        jiffies) / 1000,
1136                                 pe_data);
1137         }
1138         return 0;
1139 }
1140
1141 static const struct seq_operations ip_vs_conn_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_seq_show,
1146 };
1147
1148 static const char *ip_vs_origin_name(unsigned int flags)
1149 {
1150         if (flags & IP_VS_CONN_F_SYNC)
1151                 return "SYNC";
1152         else
1153                 return "LOCAL";
1154 }
1155
1156 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1157 {
1158         char dbuf[IP_VS_ADDRSTRLEN];
1159
1160         if (v == SEQ_START_TOKEN)
1161                 seq_puts(seq,
1162    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
1163         else {
1164                 const struct ip_vs_conn *cp = v;
1165                 struct net *net = seq_file_net(seq);
1166
1167                 if (!net_eq(cp->ipvs->net, net))
1168                         return 0;
1169
1170 #ifdef CONFIG_IP_VS_IPV6
1171                 if (cp->daf == AF_INET6)
1172                         snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1173                 else
1174 #endif
1175                         snprintf(dbuf, sizeof(dbuf), "%08X",
1176                                  ntohl(cp->daddr.ip));
1177
1178 #ifdef CONFIG_IP_VS_IPV6
1179                 if (cp->af == AF_INET6)
1180                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1181                                 "%s %04X %-11s %-6s %7u\n",
1182                                 ip_vs_proto_name(cp->protocol),
1183                                 &cp->caddr.in6, ntohs(cp->cport),
1184                                 &cp->vaddr.in6, ntohs(cp->vport),
1185                                 dbuf, ntohs(cp->dport),
1186                                 ip_vs_state_name(cp),
1187                                 ip_vs_origin_name(cp->flags),
1188                                 jiffies_delta_to_msecs(cp->timer.expires -
1189                                                        jiffies) / 1000);
1190                 else
1191 #endif
1192                         seq_printf(seq,
1193                                 "%-3s %08X %04X %08X %04X "
1194                                 "%s %04X %-11s %-6s %7u\n",
1195                                 ip_vs_proto_name(cp->protocol),
1196                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1197                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1198                                 dbuf, ntohs(cp->dport),
1199                                 ip_vs_state_name(cp),
1200                                 ip_vs_origin_name(cp->flags),
1201                                 jiffies_delta_to_msecs(cp->timer.expires -
1202                                                        jiffies) / 1000);
1203         }
1204         return 0;
1205 }
1206
1207 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1208         .start = ip_vs_conn_seq_start,
1209         .next  = ip_vs_conn_seq_next,
1210         .stop  = ip_vs_conn_seq_stop,
1211         .show  = ip_vs_conn_sync_seq_show,
1212 };
1213 #endif
1214
1215
1216 /* Randomly drop connection entries before running out of memory
1217  * Can be used for DATA and CTL conns. For TPL conns there are exceptions:
1218  * - traffic for services in OPS mode increases ct->in_pkts, so it is supported
1219  * - traffic for services not in OPS mode does not increase ct->in_pkts in
1220  * all cases, so it is not supported
1221  */
1222 static inline int todrop_entry(struct ip_vs_conn *cp)
1223 {
1224         /*
1225          * The drop rate array needs tuning for real environments.
1226          * Called from timer bh only => no locking
1227          */
1228         static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1229         static char todrop_counter[9] = {0};
1230         int i;
1231
1232         /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1233            This will leave enough time for normal connection to get
1234            through. */
1235         if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1236                 return 0;
1237
1238         /* Don't drop the entry if its number of incoming packets is not
1239            located in [0, 8] */
1240         i = atomic_read(&cp->in_pkts);
1241         if (i > 8 || i < 0) return 0;
1242
1243         if (!todrop_rate[i]) return 0;
1244         if (--todrop_counter[i] > 0) return 0;
1245
1246         todrop_counter[i] = todrop_rate[i];
1247         return 1;
1248 }
1249
1250 static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp)
1251 {
1252         struct ip_vs_service *svc;
1253
1254         if (!cp->dest)
1255                 return false;
1256         svc = rcu_dereference(cp->dest->svc);
1257         return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET);
1258 }
1259
1260 /* Called from keventd and must protect itself from softirqs */
1261 void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
1262 {
1263         int idx;
1264         struct ip_vs_conn *cp;
1265
1266         rcu_read_lock();
1267         /*
1268          * Randomly scan 1/32 of the whole table every second
1269          */
1270         for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1271                 unsigned int hash = prandom_u32() & ip_vs_conn_tab_mask;
1272
1273                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
1274                         if (cp->ipvs != ipvs)
1275                                 continue;
1276                         if (atomic_read(&cp->n_control))
1277                                 continue;
1278                         if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
1279                                 /* connection template of OPS */
1280                                 if (ip_vs_conn_ops_mode(cp))
1281                                         goto try_drop;
1282                                 if (!(cp->state & IP_VS_CTPL_S_ASSURED))
1283                                         goto drop;
1284                                 continue;
1285                         }
1286                         if (cp->protocol == IPPROTO_TCP) {
1287                                 switch(cp->state) {
1288                                 case IP_VS_TCP_S_SYN_RECV:
1289                                 case IP_VS_TCP_S_SYNACK:
1290                                         break;
1291
1292                                 case IP_VS_TCP_S_ESTABLISHED:
1293                                         if (todrop_entry(cp))
1294                                                 break;
1295                                         continue;
1296
1297                                 default:
1298                                         continue;
1299                                 }
1300                         } else if (cp->protocol == IPPROTO_SCTP) {
1301                                 switch (cp->state) {
1302                                 case IP_VS_SCTP_S_INIT1:
1303                                 case IP_VS_SCTP_S_INIT:
1304                                         break;
1305                                 case IP_VS_SCTP_S_ESTABLISHED:
1306                                         if (todrop_entry(cp))
1307                                                 break;
1308                                         continue;
1309                                 default:
1310                                         continue;
1311                                 }
1312                         } else {
1313 try_drop:
1314                                 if (!todrop_entry(cp))
1315                                         continue;
1316                         }
1317
1318 drop:
1319                         IP_VS_DBG(4, "drop connection\n");
1320                         cp->timeout = 0;
1321                         ip_vs_conn_expire_now(cp);
1322                 }
1323                 cond_resched_rcu();
1324         }
1325         rcu_read_unlock();
1326 }
1327
1328
1329 /*
1330  *      Flush all the connection entries in the ip_vs_conn_tab
1331  */
1332 static void ip_vs_conn_flush(struct netns_ipvs *ipvs)
1333 {
1334         int idx;
1335         struct ip_vs_conn *cp, *cp_c;
1336
1337 flush_again:
1338         rcu_read_lock();
1339         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1340
1341                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1342                         if (cp->ipvs != ipvs)
1343                                 continue;
1344                         /* As timers are expired in LIFO order, restart
1345                          * the timer of controlling connection first, so
1346                          * that it is expired after us.
1347                          */
1348                         cp_c = cp->control;
1349                         /* cp->control is valid only with reference to cp */
1350                         if (cp_c && __ip_vs_conn_get(cp)) {
1351                                 IP_VS_DBG(4, "del controlling connection\n");
1352                                 ip_vs_conn_expire_now(cp_c);
1353                                 __ip_vs_conn_put(cp);
1354                         }
1355                         IP_VS_DBG(4, "del connection\n");
1356                         ip_vs_conn_expire_now(cp);
1357                 }
1358                 cond_resched_rcu();
1359         }
1360         rcu_read_unlock();
1361
1362         /* the counter may be not NULL, because maybe some conn entries
1363            are run by slow timer handler or unhashed but still referred */
1364         if (atomic_read(&ipvs->conn_count) != 0) {
1365                 schedule();
1366                 goto flush_again;
1367         }
1368 }
1369 /*
1370  * per netns init and exit
1371  */
1372 int __net_init ip_vs_conn_net_init(struct netns_ipvs *ipvs)
1373 {
1374         atomic_set(&ipvs->conn_count, 0);
1375
1376         proc_create_net("ip_vs_conn", 0, ipvs->net->proc_net,
1377                         &ip_vs_conn_seq_ops, sizeof(struct ip_vs_iter_state));
1378         proc_create_net("ip_vs_conn_sync", 0, ipvs->net->proc_net,
1379                         &ip_vs_conn_sync_seq_ops,
1380                         sizeof(struct ip_vs_iter_state));
1381         return 0;
1382 }
1383
1384 void __net_exit ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs)
1385 {
1386         /* flush all the connection entries first */
1387         ip_vs_conn_flush(ipvs);
1388         remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
1389         remove_proc_entry("ip_vs_conn_sync", ipvs->net->proc_net);
1390 }
1391
1392 int __init ip_vs_conn_init(void)
1393 {
1394         int idx;
1395
1396         /* Compute size and mask */
1397         ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1398         ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1399
1400         /*
1401          * Allocate the connection hash table and initialize its list heads
1402          */
1403         ip_vs_conn_tab = vmalloc(array_size(ip_vs_conn_tab_size,
1404                                             sizeof(*ip_vs_conn_tab)));
1405         if (!ip_vs_conn_tab)
1406                 return -ENOMEM;
1407
1408         /* Allocate ip_vs_conn slab cache */
1409         ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1410                                               sizeof(struct ip_vs_conn), 0,
1411                                               SLAB_HWCACHE_ALIGN, NULL);
1412         if (!ip_vs_conn_cachep) {
1413                 vfree(ip_vs_conn_tab);
1414                 return -ENOMEM;
1415         }
1416
1417         pr_info("Connection hash table configured "
1418                 "(size=%d, memory=%ldKbytes)\n",
1419                 ip_vs_conn_tab_size,
1420                 (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
1421         IP_VS_DBG(0, "Each connection entry needs %zd bytes at least\n",
1422                   sizeof(struct ip_vs_conn));
1423
1424         for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1425                 INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1426
1427         for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1428                 spin_lock_init(&__ip_vs_conntbl_lock_array[idx].l);
1429         }
1430
1431         /* calculate the random value for connection hash */
1432         get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1433
1434         return 0;
1435 }
1436
1437 void ip_vs_conn_cleanup(void)
1438 {
1439         /* Wait all ip_vs_conn_rcu_free() callbacks to complete */
1440         rcu_barrier();
1441         /* Release the empty cache */
1442         kmem_cache_destroy(ip_vs_conn_cachep);
1443         vfree(ip_vs_conn_tab);
1444 }