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/inet.h>
  31 #include <linux/net.h>
  32 #include <linux/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/vmalloc.h>
  35 #include <linux/proc_fs.h>              /* for proc_net_* */
  36 #include <linux/slab.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/jhash.h>
  39 #include <linux/random.h>
  40
  41 #include <net/net_namespace.h>
  42 #include <net/ip_vs.h>
  43
  44
  45 #ifndef CONFIG_IP_VS_TAB_BITS
  46 #define CONFIG_IP_VS_TAB_BITS   12
  47 #endif
  48
  49 /*
  50  * Connection hash size. Default is what was selected at compile time.
  51 */
  52 static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
  53 module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
  54 MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
  55
  56 /* size and mask values */
  57 int ip_vs_conn_tab_size __read_mostly;
  58 static int ip_vs_conn_tab_mask __read_mostly;
  59
  60 /*
  61  *  Connection hash table: for input and output packets lookups of IPVS
  62  */
  63 static struct hlist_head *ip_vs_conn_tab __read_mostly;
  64
  65 /*  SLAB cache for IPVS connections */
  66 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
  67
  68 /*  counter for no client port connections */
  69 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
  70
  71 /* random value for IPVS connection hash */
  72 static unsigned int ip_vs_conn_rnd __read_mostly;
  73
  74 /*
  75  *  Fine locking granularity for big connection hash table
  76  */
  77 #define CT_LOCKARRAY_BITS  5
  78 #define CT_LOCKARRAY_SIZE  (1<<CT_LOCKARRAY_BITS)
  79 #define CT_LOCKARRAY_MASK  (CT_LOCKARRAY_SIZE-1)
  80
  81 /* We need an addrstrlen that works with or without v6 */
  82 #ifdef CONFIG_IP_VS_IPV6
  83 #define IP_VS_ADDRSTRLEN INET6_ADDRSTRLEN
  84 #else
  85 #define IP_VS_ADDRSTRLEN (8+1)
  86 #endif
  87
  88 struct ip_vs_aligned_lock
  89 {
  90         spinlock_t      l;
  91 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
  92
  93 /* lock array for conn table */
  94 static struct ip_vs_aligned_lock
  95 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
  96
  97 static inline void ct_write_lock_bh(unsigned int key)
  98 {
  99         spin_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 100 }
 101
 102 static inline void ct_write_unlock_bh(unsigned int key)
 103 {
 104         spin_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 105 }
 106
 107 static void ip_vs_conn_expire(unsigned long data);
 108
 109 /*
 110  *      Returns hash value for IPVS connection entry
 111  */
 112 static unsigned int ip_vs_conn_hashkey(struct netns_ipvs *ipvs, int af, unsigned int proto,
 113                                        const union nf_inet_addr *addr,
 114                                        __be16 port)
 115 {
 116 #ifdef CONFIG_IP_VS_IPV6
 117         if (af == AF_INET6)
 118                 return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
 119                                     (__force u32)port, proto, ip_vs_conn_rnd) ^
 120                         ((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
 121 #endif
 122         return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
 123                             ip_vs_conn_rnd) ^
 124                 ((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
 125 }
 126
 127 static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p,
 128                                              bool inverse)
 129 {
 130         const union nf_inet_addr *addr;
 131         __be16 port;
 132
 133         if (p->pe_data && p->pe->hashkey_raw)
 134                 return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) &
 135                         ip_vs_conn_tab_mask;
 136
 137         if (likely(!inverse)) {
 138                 addr = p->caddr;
 139                 port = p->cport;
 140         } else {
 141                 addr = p->vaddr;
 142                 port = p->vport;
 143         }
 144
 145         return ip_vs_conn_hashkey(p->ipvs, p->af, p->protocol, addr, port);
 146 }
 147
 148 static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp)
 149 {
 150         struct ip_vs_conn_param p;
 151
 152         ip_vs_conn_fill_param(cp->ipvs, cp->af, cp->protocol,
 153                               &cp->caddr, cp->cport, NULL, 0, &p);
 154
 155         if (cp->pe) {
 156                 p.pe = cp->pe;
 157                 p.pe_data = cp->pe_data;
 158                 p.pe_data_len = cp->pe_data_len;
 159         }
 160
 161         return ip_vs_conn_hashkey_param(&p, false);
 162 }
 163
 164 /*
 165  *      Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port.
 166  *      returns bool success.
 167  */
 168 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
 169 {
 170         unsigned int hash;
 171         int ret;
 172
 173         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 174                 return 0;
 175
 176         /* Hash by protocol, client address and port */
 177         hash = ip_vs_conn_hashkey_conn(cp);
 178
 179         ct_write_lock_bh(hash);
 180         spin_lock(&cp->lock);
 181
 182         if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
 183                 cp->flags |= IP_VS_CONN_F_HASHED;
 184                 atomic_inc(&cp->refcnt);
 185                 hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]);
 186                 ret = 1;
 187         } else {
 188                 pr_err("%s(): request for already hashed, called from %pF\n",
 189                        __func__, __builtin_return_address(0));
 190                 ret = 0;
 191         }
 192
 193         spin_unlock(&cp->lock);
 194         ct_write_unlock_bh(hash);
 195
 196         return ret;
 197 }
 198
 199
 200 /*
 201  *      UNhashes ip_vs_conn from ip_vs_conn_tab.
 202  *      returns bool success. Caller should hold conn reference.
 203  */
 204 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
 205 {
 206         unsigned int hash;
 207         int ret;
 208
 209         /* unhash it and decrease its reference counter */
 210         hash = ip_vs_conn_hashkey_conn(cp);
 211
 212         ct_write_lock_bh(hash);
 213         spin_lock(&cp->lock);
 214
 215         if (cp->flags & IP_VS_CONN_F_HASHED) {
 216                 hlist_del_rcu(&cp->c_list);
 217                 cp->flags &= ~IP_VS_CONN_F_HASHED;
 218                 atomic_dec(&cp->refcnt);
 219                 ret = 1;
 220         } else
 221                 ret = 0;
 222
 223         spin_unlock(&cp->lock);
 224         ct_write_unlock_bh(hash);
 225
 226         return ret;
 227 }
 228
 229 /* Try to unlink ip_vs_conn from ip_vs_conn_tab.
 230  * returns bool success.
 231  */
 232 static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp)
 233 {
 234         unsigned int hash;
 235         bool ret;
 236
 237         hash = ip_vs_conn_hashkey_conn(cp);
 238
 239         ct_write_lock_bh(hash);
 240         spin_lock(&cp->lock);
 241
 242         if (cp->flags & IP_VS_CONN_F_HASHED) {
 243                 ret = false;
 244                 /* Decrease refcnt and unlink conn only if we are last user */
 245                 if (atomic_cmpxchg(&cp->refcnt, 1, 0) == 1) {
 246                         hlist_del_rcu(&cp->c_list);
 247                         cp->flags &= ~IP_VS_CONN_F_HASHED;
 248                         ret = true;
 249                 }
 250         } else
 251                 ret = atomic_read(&cp->refcnt) ? false : true;
 252
 253         spin_unlock(&cp->lock);
 254         ct_write_unlock_bh(hash);
 255
 256         return ret;
 257 }
 258
 259
 260 /*
 261  *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 262  *  Called for pkts coming from OUTside-to-INside.
 263  *      p->caddr, p->cport: pkt source address (foreign host)
 264  *      p->vaddr, p->vport: pkt dest address (load balancer)
 265  */
 266 static inline struct ip_vs_conn *
 267 __ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
 268 {
 269         unsigned int hash;
 270         struct ip_vs_conn *cp;
 271
 272         hash = ip_vs_conn_hashkey_param(p, false);
 273
 274         rcu_read_lock();
 275
 276         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 277                 if (p->cport == cp->cport && p->vport == cp->vport &&
 278                     cp->af == p->af &&
 279                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 280                     ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) &&
 281                     ((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
 282                     p->protocol == cp->protocol &&
 283                     cp->ipvs == p->ipvs) {
 284                         if (!__ip_vs_conn_get(cp))
 285                                 continue;
 286                         /* HIT */
 287                         rcu_read_unlock();
 288                         return cp;
 289                 }
 290         }
 291
 292         rcu_read_unlock();
 293
 294         return NULL;
 295 }
 296
 297 struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
 298 {
 299         struct ip_vs_conn *cp;
 300
 301         cp = __ip_vs_conn_in_get(p);
 302         if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) {
 303                 struct ip_vs_conn_param cport_zero_p = *p;
 304                 cport_zero_p.cport = 0;
 305                 cp = __ip_vs_conn_in_get(&cport_zero_p);
 306         }
 307
 308         IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
 309                       ip_vs_proto_name(p->protocol),
 310                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 311                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 312                       cp ? "hit" : "not hit");
 313
 314         return cp;
 315 }
 316
 317 static int
 318 ip_vs_conn_fill_param_proto(struct netns_ipvs *ipvs,
 319                             int af, const struct sk_buff *skb,
 320                             const struct ip_vs_iphdr *iph,
 321                             struct ip_vs_conn_param *p)
 322 {
 323         __be16 _ports[2], *pptr;
 324
 325         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
 326         if (pptr == NULL)
 327                 return 1;
 328
 329         if (likely(!ip_vs_iph_inverse(iph)))
 330                 ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->saddr,
 331                                       pptr[0], &iph->daddr, pptr[1], p);
 332         else
 333                 ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->daddr,
 334                                       pptr[1], &iph->saddr, pptr[0], p);
 335         return 0;
 336 }
 337
 338 struct ip_vs_conn *
 339 ip_vs_conn_in_get_proto(struct netns_ipvs *ipvs, int af,
 340                         const struct sk_buff *skb,
 341                         const struct ip_vs_iphdr *iph)
 342 {
 343         struct ip_vs_conn_param p;
 344
 345         if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
 346                 return NULL;
 347
 348         return ip_vs_conn_in_get(&p);
 349 }
 350 EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
 351
 352 /* Get reference to connection template */
 353 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
 354 {
 355         unsigned int hash;
 356         struct ip_vs_conn *cp;
 357
 358         hash = ip_vs_conn_hashkey_param(p, false);
 359
 360         rcu_read_lock();
 361
 362         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 363                 if (unlikely(p->pe_data && p->pe->ct_match)) {
 364                         if (cp->ipvs != p->ipvs)
 365                                 continue;
 366                         if (p->pe == cp->pe && p->pe->ct_match(p, cp)) {
 367                                 if (__ip_vs_conn_get(cp))
 368                                         goto out;
 369                         }
 370                         continue;
 371                 }
 372
 373                 if (cp->af == p->af &&
 374                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 375                     /* protocol should only be IPPROTO_IP if
 376                      * p->vaddr is a fwmark */
 377                     ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
 378                                      p->af, p->vaddr, &cp->vaddr) &&
 379                     p->vport == cp->vport && p->cport == cp->cport &&
 380                     cp->flags & IP_VS_CONN_F_TEMPLATE &&
 381                     p->protocol == cp->protocol &&
 382                     cp->ipvs == p->ipvs) {
 383                         if (__ip_vs_conn_get(cp))
 384                                 goto out;
 385                 }
 386         }
 387         cp = NULL;
 388
 389   out:
 390         rcu_read_unlock();
 391
 392         IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
 393                       ip_vs_proto_name(p->protocol),
 394                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 395                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 396                       cp ? "hit" : "not hit");
 397
 398         return cp;
 399 }
 400
 401 /* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 402  * Called for pkts coming from inside-to-OUTside.
 403  *      p->caddr, p->cport: pkt source address (inside host)
 404  *      p->vaddr, p->vport: pkt dest address (foreign host) */
 405 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
 406 {
 407         unsigned int hash;
 408         struct ip_vs_conn *cp, *ret=NULL;
 409
 410         /*
 411          *      Check for "full" addressed entries
 412          */
 413         hash = ip_vs_conn_hashkey_param(p, true);
 414
 415         rcu_read_lock();
 416
 417         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 418                 if (p->vport == cp->cport && p->cport == cp->dport &&
 419                     cp->af == p->af &&
 420                     ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
 421                     ip_vs_addr_equal(p->af, p->caddr, &cp->daddr) &&
 422                     p->protocol == cp->protocol &&
 423                     cp->ipvs == p->ipvs) {
 424                         if (!__ip_vs_conn_get(cp))
 425                                 continue;
 426                         /* HIT */
 427                         ret = cp;
 428                         break;
 429                 }
 430         }
 431
 432         rcu_read_unlock();
 433
 434         IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
 435                       ip_vs_proto_name(p->protocol),
 436                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 437                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 438                       ret ? "hit" : "not hit");
 439
 440         return ret;
 441 }
 442
 443 struct ip_vs_conn *
 444 ip_vs_conn_out_get_proto(struct netns_ipvs *ipvs, int af,
 445                          const struct sk_buff *skb,
 446                          const struct ip_vs_iphdr *iph)
 447 {
 448         struct ip_vs_conn_param p;
 449
 450         if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
 451                 return NULL;
 452
 453         return ip_vs_conn_out_get(&p);
 454 }
 455 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
 456
 457 static void __ip_vs_conn_put_notimer(struct ip_vs_conn *cp)
 458 {
 459         __ip_vs_conn_put(cp);
 460         ip_vs_conn_expire((unsigned long)cp);
 461 }
 462
 463 /*
 464  *      Put back the conn and restart its timer with its timeout
 465  */
 466 static void __ip_vs_conn_put_timer(struct ip_vs_conn *cp)
 467 {
 468         unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
 469                 0 : cp->timeout;
 470         mod_timer(&cp->timer, jiffies+t);
 471
 472         __ip_vs_conn_put(cp);
 473 }
 474
 475 void ip_vs_conn_put(struct ip_vs_conn *cp)
 476 {
 477         if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) &&
 478             (atomic_read(&cp->refcnt) == 1) &&
 479             !timer_pending(&cp->timer))
 480                 /* expire connection immediately */
 481                 __ip_vs_conn_put_notimer(cp);
 482         else
 483                 __ip_vs_conn_put_timer(cp);
 484 }
 485
 486 /*
 487  *      Fill a no_client_port connection with a client port number
 488  */
 489 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
 490 {
 491         if (ip_vs_conn_unhash(cp)) {
 492                 spin_lock_bh(&cp->lock);
 493                 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
 494                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 495                         cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
 496                         cp->cport = cport;
 497                 }
 498                 spin_unlock_bh(&cp->lock);
 499
 500                 /* hash on new dport */
 501                 ip_vs_conn_hash(cp);
 502         }
 503 }
 504
 505
 506 /*
 507  *      Bind a connection entry with the corresponding packet_xmit.
 508  *      Called by ip_vs_conn_new.
 509  */
 510 static inline void ip_vs_bind_xmit(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;
 515                 break;
 516
 517         case IP_VS_CONN_F_TUNNEL:
 518 #ifdef CONFIG_IP_VS_IPV6
 519                 if (cp->daf == AF_INET6)
 520                         cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 521                 else
 522 #endif
 523                         cp->packet_xmit = ip_vs_tunnel_xmit;
 524                 break;
 525
 526         case IP_VS_CONN_F_DROUTE:
 527                 cp->packet_xmit = ip_vs_dr_xmit;
 528                 break;
 529
 530         case IP_VS_CONN_F_LOCALNODE:
 531                 cp->packet_xmit = ip_vs_null_xmit;
 532                 break;
 533
 534         case IP_VS_CONN_F_BYPASS:
 535                 cp->packet_xmit = ip_vs_bypass_xmit;
 536                 break;
 537         }
 538 }
 539
 540 #ifdef CONFIG_IP_VS_IPV6
 541 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
 542 {
 543         switch (IP_VS_FWD_METHOD(cp)) {
 544         case IP_VS_CONN_F_MASQ:
 545                 cp->packet_xmit = ip_vs_nat_xmit_v6;
 546                 break;
 547
 548         case IP_VS_CONN_F_TUNNEL:
 549                 if (cp->daf == AF_INET6)
 550                         cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 551                 else
 552                         cp->packet_xmit = ip_vs_tunnel_xmit;
 553                 break;
 554
 555         case IP_VS_CONN_F_DROUTE:
 556                 cp->packet_xmit = ip_vs_dr_xmit_v6;
 557                 break;
 558
 559         case IP_VS_CONN_F_LOCALNODE:
 560                 cp->packet_xmit = ip_vs_null_xmit;
 561                 break;
 562
 563         case IP_VS_CONN_F_BYPASS:
 564                 cp->packet_xmit = ip_vs_bypass_xmit_v6;
 565                 break;
 566         }
 567 }
 568 #endif
 569
 570
 571 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
 572 {
 573         return atomic_read(&dest->activeconns)
 574                 + atomic_read(&dest->inactconns);
 575 }
 576
 577 /*
 578  *      Bind a connection entry with a virtual service destination
 579  *      Called just after a new connection entry is created.
 580  */
 581 static inline void
 582 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
 583 {
 584         unsigned int conn_flags;
 585         __u32 flags;
 586
 587         /* if dest is NULL, then return directly */
 588         if (!dest)
 589                 return;
 590
 591         /* Increase the refcnt counter of the dest */
 592         ip_vs_dest_hold(dest);
 593
 594         conn_flags = atomic_read(&dest->conn_flags);
 595         if (cp->protocol != IPPROTO_UDP)
 596                 conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
 597         flags = cp->flags;
 598         /* Bind with the destination and its corresponding transmitter */
 599         if (flags & IP_VS_CONN_F_SYNC) {
 600                 /* if the connection is not template and is created
 601                  * by sync, preserve the activity flag.
 602                  */
 603                 if (!(flags & IP_VS_CONN_F_TEMPLATE))
 604                         conn_flags &= ~IP_VS_CONN_F_INACTIVE;
 605                 /* connections inherit forwarding method from dest */
 606                 flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
 607         }
 608         flags |= conn_flags;
 609         cp->flags = flags;
 610         cp->dest = dest;
 611
 612         IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
 613                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 614                       "dest->refcnt:%d\n",
 615                       ip_vs_proto_name(cp->protocol),
 616                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 617                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 618                       IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
 619                       ip_vs_fwd_tag(cp), cp->state,
 620                       cp->flags, atomic_read(&cp->refcnt),
 621                       atomic_read(&dest->refcnt));
 622
 623         /* Update the connection counters */
 624         if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
 625                 /* It is a normal connection, so modify the counters
 626                  * according to the flags, later the protocol can
 627                  * update them on state change
 628                  */
 629                 if (!(flags & IP_VS_CONN_F_INACTIVE))
 630                         atomic_inc(&dest->activeconns);
 631                 else
 632                         atomic_inc(&dest->inactconns);
 633         } else {
 634                 /* It is a persistent connection/template, so increase
 635                    the persistent connection counter */
 636                 atomic_inc(&dest->persistconns);
 637         }
 638
 639         if (dest->u_threshold != 0 &&
 640             ip_vs_dest_totalconns(dest) >= dest->u_threshold)
 641                 dest->flags |= IP_VS_DEST_F_OVERLOAD;
 642 }
 643
 644
 645 /*
 646  * Check if there is a destination for the connection, if so
 647  * bind the connection to the destination.
 648  */
 649 void ip_vs_try_bind_dest(struct ip_vs_conn *cp)
 650 {
 651         struct ip_vs_dest *dest;
 652
 653         rcu_read_lock();
 654
 655         /* This function is only invoked by the synchronization code. We do
 656          * not currently support heterogeneous pools with synchronization,
 657          * so we can make the assumption that the svc_af is the same as the
 658          * dest_af
 659          */
 660         dest = ip_vs_find_dest(cp->ipvs, cp->af, cp->af, &cp->daddr,
 661                                cp->dport, &cp->vaddr, cp->vport,
 662                                cp->protocol, cp->fwmark, cp->flags);
 663         if (dest) {
 664                 struct ip_vs_proto_data *pd;
 665
 666                 spin_lock_bh(&cp->lock);
 667                 if (cp->dest) {
 668                         spin_unlock_bh(&cp->lock);
 669                         rcu_read_unlock();
 670                         return;
 671                 }
 672
 673                 /* Applications work depending on the forwarding method
 674                  * but better to reassign them always when binding dest */
 675                 if (cp->app)
 676                         ip_vs_unbind_app(cp);
 677
 678                 ip_vs_bind_dest(cp, dest);
 679                 spin_unlock_bh(&cp->lock);
 680
 681                 /* Update its packet transmitter */
 682                 cp->packet_xmit = NULL;
 683 #ifdef CONFIG_IP_VS_IPV6
 684                 if (cp->af == AF_INET6)
 685                         ip_vs_bind_xmit_v6(cp);
 686                 else
 687 #endif
 688                         ip_vs_bind_xmit(cp);
 689
 690                 pd = ip_vs_proto_data_get(cp->ipvs, cp->protocol);
 691                 if (pd && atomic_read(&pd->appcnt))
 692                         ip_vs_bind_app(cp, pd->pp);
 693         }
 694         rcu_read_unlock();
 695 }
 696
 697
 698 /*
 699  *      Unbind a connection entry with its VS destination
 700  *      Called by the ip_vs_conn_expire function.
 701  */
 702 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
 703 {
 704         struct ip_vs_dest *dest = cp->dest;
 705
 706         if (!dest)
 707                 return;
 708
 709         IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
 710                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 711                       "dest->refcnt:%d\n",
 712                       ip_vs_proto_name(cp->protocol),
 713                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 714                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 715                       IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
 716                       ip_vs_fwd_tag(cp), cp->state,
 717                       cp->flags, atomic_read(&cp->refcnt),
 718                       atomic_read(&dest->refcnt));
 719
 720         /* Update the connection counters */
 721         if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
 722                 /* It is a normal connection, so decrease the inactconns
 723                    or activeconns counter */
 724                 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
 725                         atomic_dec(&dest->inactconns);
 726                 } else {
 727                         atomic_dec(&dest->activeconns);
 728                 }
 729         } else {
 730                 /* It is a persistent connection/template, so decrease
 731                    the persistent connection counter */
 732                 atomic_dec(&dest->persistconns);
 733         }
 734
 735         if (dest->l_threshold != 0) {
 736                 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
 737                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 738         } else if (dest->u_threshold != 0) {
 739                 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
 740                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 741         } else {
 742                 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 743                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 744         }
 745
 746         ip_vs_dest_put(dest);
 747 }
 748
 749 static int expire_quiescent_template(struct netns_ipvs *ipvs,
 750                                      struct ip_vs_dest *dest)
 751 {
 752 #ifdef CONFIG_SYSCTL
 753         return ipvs->sysctl_expire_quiescent_template &&
 754                 (atomic_read(&dest->weight) == 0);
 755 #else
 756         return 0;
 757 #endif
 758 }
 759
 760 /*
 761  *      Checking if the destination of a connection template is available.
 762  *      If available, return 1, otherwise invalidate this connection
 763  *      template and return 0.
 764  */
 765 int ip_vs_check_template(struct ip_vs_conn *ct)
 766 {
 767         struct ip_vs_dest *dest = ct->dest;
 768         struct netns_ipvs *ipvs = ct->ipvs;
 769
 770         /*
 771          * Checking the dest server status.
 772          */
 773         if ((dest == NULL) ||
 774             !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
 775             expire_quiescent_template(ipvs, dest)) {
 776                 IP_VS_DBG_BUF(9, "check_template: dest not available for "
 777                               "protocol %s s:%s:%d v:%s:%d "
 778                               "-> d:%s:%d\n",
 779                               ip_vs_proto_name(ct->protocol),
 780                               IP_VS_DBG_ADDR(ct->af, &ct->caddr),
 781                               ntohs(ct->cport),
 782                               IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
 783                               ntohs(ct->vport),
 784                               IP_VS_DBG_ADDR(ct->daf, &ct->daddr),
 785                               ntohs(ct->dport));
 786
 787                 /*
 788                  * Invalidate the connection template
 789                  */
 790                 if (ct->vport != htons(0xffff)) {
 791                         if (ip_vs_conn_unhash(ct)) {
 792                                 ct->dport = htons(0xffff);
 793                                 ct->vport = htons(0xffff);
 794                                 ct->cport = 0;
 795                                 ip_vs_conn_hash(ct);
 796                         }
 797                 }
 798
 799                 /*
 800                  * Simply decrease the refcnt of the template,
 801                  * don't restart its timer.
 802                  */
 803                 __ip_vs_conn_put(ct);
 804                 return 0;
 805         }
 806         return 1;
 807 }
 808
 809 static void ip_vs_conn_rcu_free(struct rcu_head *head)
 810 {
 811         struct ip_vs_conn *cp = container_of(head, struct ip_vs_conn,
 812                                              rcu_head);
 813
 814         ip_vs_pe_put(cp->pe);
 815         kfree(cp->pe_data);
 816         kmem_cache_free(ip_vs_conn_cachep, cp);
 817 }
 818
 819 static void ip_vs_conn_expire(unsigned long data)
 820 {
 821         struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
 822         struct netns_ipvs *ipvs = cp->ipvs;
 823
 824         /*
 825          *      do I control anybody?
 826          */
 827         if (atomic_read(&cp->n_control))
 828                 goto expire_later;
 829
 830         /* Unlink conn if not referenced anymore */
 831         if (likely(ip_vs_conn_unlink(cp))) {
 832                 /* delete the timer if it is activated by other users */
 833                 del_timer(&cp->timer);
 834
 835                 /* does anybody control me? */
 836                 if (cp->control)
 837                         ip_vs_control_del(cp);
 838
 839                 if ((cp->flags & IP_VS_CONN_F_NFCT) &&
 840                     !(cp->flags & IP_VS_CONN_F_ONE_PACKET)) {
 841                         /* Do not access conntracks during subsys cleanup
 842                          * because nf_conntrack_find_get can not be used after
 843                          * conntrack cleanup for the net.
 844                          */
 845                         smp_rmb();
 846                         if (ipvs->enable)
 847                                 ip_vs_conn_drop_conntrack(cp);
 848                 }
 849
 850                 if (unlikely(cp->app != NULL))
 851                         ip_vs_unbind_app(cp);
 852                 ip_vs_unbind_dest(cp);
 853                 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
 854                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 855                 if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 856                         ip_vs_conn_rcu_free(&cp->rcu_head);
 857                 else
 858                         call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
 859                 atomic_dec(&ipvs->conn_count);
 860                 return;
 861         }
 862
 863   expire_later:
 864         IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
 865                   atomic_read(&cp->refcnt),
 866                   atomic_read(&cp->n_control));
 867
 868         atomic_inc(&cp->refcnt);
 869         cp->timeout = 60*HZ;
 870
 871         if (ipvs->sync_state & IP_VS_STATE_MASTER)
 872                 ip_vs_sync_conn(ipvs, cp, sysctl_sync_threshold(ipvs));
 873
 874         __ip_vs_conn_put_timer(cp);
 875 }
 876
 877 /* Modify timer, so that it expires as soon as possible.
 878  * Can be called without reference only if under RCU lock.
 879  */
 880 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
 881 {
 882         /* Using mod_timer_pending will ensure the timer is not
 883          * modified after the final del_timer in ip_vs_conn_expire.
 884          */
 885         if (timer_pending(&cp->timer) &&
 886             time_after(cp->timer.expires, jiffies))
 887                 mod_timer_pending(&cp->timer, jiffies);
 888 }
 889
 890
 891 /*
 892  *      Create a new connection entry and hash it into the ip_vs_conn_tab
 893  */
 894 struct ip_vs_conn *
 895 ip_vs_conn_new(const struct ip_vs_conn_param *p, int dest_af,
 896                const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
 897                struct ip_vs_dest *dest, __u32 fwmark)
 898 {
 899         struct ip_vs_conn *cp;
 900         struct netns_ipvs *ipvs = p->ipvs;
 901         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->ipvs,
 902                                                            p->protocol);
 903
 904         cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
 905         if (cp == NULL) {
 906                 IP_VS_ERR_RL("%s(): no memory\n", __func__);
 907                 return NULL;
 908         }
 909
 910         INIT_HLIST_NODE(&cp->c_list);
 911         setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
 912         cp->ipvs           = ipvs;
 913         cp->af             = p->af;
 914         cp->daf            = dest_af;
 915         cp->protocol       = p->protocol;
 916         ip_vs_addr_set(p->af, &cp->caddr, p->caddr);
 917         cp->cport          = p->cport;
 918         /* proto should only be IPPROTO_IP if p->vaddr is a fwmark */
 919         ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
 920                        &cp->vaddr, p->vaddr);
 921         cp->vport          = p->vport;
 922         ip_vs_addr_set(cp->daf, &cp->daddr, daddr);
 923         cp->dport          = dport;
 924         cp->flags          = flags;
 925         cp->fwmark         = fwmark;
 926         if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
 927                 ip_vs_pe_get(p->pe);
 928                 cp->pe = p->pe;
 929                 cp->pe_data = p->pe_data;
 930                 cp->pe_data_len = p->pe_data_len;
 931         } else {
 932                 cp->pe = NULL;
 933                 cp->pe_data = NULL;
 934                 cp->pe_data_len = 0;
 935         }
 936         spin_lock_init(&cp->lock);
 937
 938         /*
 939          * Set the entry is referenced by the current thread before hashing
 940          * it in the table, so that other thread run ip_vs_random_dropentry
 941          * but cannot drop this entry.
 942          */
 943         atomic_set(&cp->refcnt, 1);
 944
 945         cp->control = NULL;
 946         atomic_set(&cp->n_control, 0);
 947         atomic_set(&cp->in_pkts, 0);
 948
 949         cp->packet_xmit = NULL;
 950         cp->app = NULL;
 951         cp->app_data = NULL;
 952         /* reset struct ip_vs_seq */
 953         cp->in_seq.delta = 0;
 954         cp->out_seq.delta = 0;
 955
 956         atomic_inc(&ipvs->conn_count);
 957         if (flags & IP_VS_CONN_F_NO_CPORT)
 958                 atomic_inc(&ip_vs_conn_no_cport_cnt);
 959
 960         /* Bind the connection with a destination server */
 961         cp->dest = NULL;
 962         ip_vs_bind_dest(cp, dest);
 963
 964         /* Set its state and timeout */
 965         cp->state = 0;
 966         cp->old_state = 0;
 967         cp->timeout = 3*HZ;
 968         cp->sync_endtime = jiffies & ~3UL;
 969
 970         /* Bind its packet transmitter */
 971 #ifdef CONFIG_IP_VS_IPV6
 972         if (p->af == AF_INET6)
 973                 ip_vs_bind_xmit_v6(cp);
 974         else
 975 #endif
 976                 ip_vs_bind_xmit(cp);
 977
 978         if (unlikely(pd && atomic_read(&pd->appcnt)))
 979                 ip_vs_bind_app(cp, pd->pp);
 980
 981         /*
 982          * Allow conntrack to be preserved. By default, conntrack
 983          * is created and destroyed for every packet.
 984          * Sometimes keeping conntrack can be useful for
 985          * IP_VS_CONN_F_ONE_PACKET too.
 986          */
 987
 988         if (ip_vs_conntrack_enabled(ipvs))
 989                 cp->flags |= IP_VS_CONN_F_NFCT;
 990
 991         /* Hash it in the ip_vs_conn_tab finally */
 992         ip_vs_conn_hash(cp);
 993
 994         return cp;
 995 }
 996
 997 /*
 998  *      /proc/net/ip_vs_conn entries
 999  */
1000 #ifdef CONFIG_PROC_FS
1001 struct ip_vs_iter_state {
1002         struct seq_net_private  p;
1003         struct hlist_head       *l;
1004 };
1005
1006 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
1007 {
1008         int idx;
1009         struct ip_vs_conn *cp;
1010         struct ip_vs_iter_state *iter = seq->private;
1011
1012         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1013                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1014                         /* __ip_vs_conn_get() is not needed by
1015                          * ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show
1016                          */
1017                         if (pos-- == 0) {
1018                                 iter->l = &ip_vs_conn_tab[idx];
1019                                 return cp;
1020                         }
1021                 }
1022                 cond_resched_rcu();
1023         }
1024
1025         return NULL;
1026 }
1027
1028 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
1029         __acquires(RCU)
1030 {
1031         struct ip_vs_iter_state *iter = seq->private;
1032
1033         iter->l = NULL;
1034         rcu_read_lock();
1035         return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
1036 }
1037
1038 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1039 {
1040         struct ip_vs_conn *cp = v;
1041         struct ip_vs_iter_state *iter = seq->private;
1042         struct hlist_node *e;
1043         struct hlist_head *l = iter->l;
1044         int idx;
1045
1046         ++*pos;
1047         if (v == SEQ_START_TOKEN)
1048                 return ip_vs_conn_array(seq, 0);
1049
1050         /* more on same hash chain? */
1051         e = rcu_dereference(hlist_next_rcu(&cp->c_list));
1052         if (e)
1053                 return hlist_entry(e, struct ip_vs_conn, c_list);
1054
1055         idx = l - ip_vs_conn_tab;
1056         while (++idx < ip_vs_conn_tab_size) {
1057                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1058                         iter->l = &ip_vs_conn_tab[idx];
1059                         return cp;
1060                 }
1061                 cond_resched_rcu();
1062         }
1063         iter->l = NULL;
1064         return NULL;
1065 }
1066
1067 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1068         __releases(RCU)
1069 {
1070         rcu_read_unlock();
1071 }
1072
1073 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1074 {
1075
1076         if (v == SEQ_START_TOKEN)
1077                 seq_puts(seq,
1078    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires PEName PEData\n");
1079         else {
1080                 const struct ip_vs_conn *cp = v;
1081                 struct net *net = seq_file_net(seq);
1082                 char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1083                 size_t len = 0;
1084                 char dbuf[IP_VS_ADDRSTRLEN];
1085
1086                 if (!net_eq(cp->ipvs->net, net))
1087                         return 0;
1088                 if (cp->pe_data) {
1089                         pe_data[0] = ' ';
1090                         len = strlen(cp->pe->name);
1091                         memcpy(pe_data + 1, cp->pe->name, len);
1092                         pe_data[len + 1] = ' ';
1093                         len += 2;
1094                         len += cp->pe->show_pe_data(cp, pe_data + len);
1095                 }
1096                 pe_data[len] = '\0';
1097
1098 #ifdef CONFIG_IP_VS_IPV6
1099                 if (cp->daf == AF_INET6)
1100                         snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1101                 else
1102 #endif
1103                         snprintf(dbuf, sizeof(dbuf), "%08X",
1104                                  ntohl(cp->daddr.ip));
1105
1106 #ifdef CONFIG_IP_VS_IPV6
1107                 if (cp->af == AF_INET6)
1108                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1109                                 "%s %04X %-11s %7lu%s\n",
1110                                 ip_vs_proto_name(cp->protocol),
1111                                 &cp->caddr.in6, ntohs(cp->cport),
1112                                 &cp->vaddr.in6, ntohs(cp->vport),
1113                                 dbuf, ntohs(cp->dport),
1114                                 ip_vs_state_name(cp->protocol, cp->state),
1115                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1116                 else
1117 #endif
1118                         seq_printf(seq,
1119                                 "%-3s %08X %04X %08X %04X"
1120                                 " %s %04X %-11s %7lu%s\n",
1121                                 ip_vs_proto_name(cp->protocol),
1122                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1123                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1124                                 dbuf, ntohs(cp->dport),
1125                                 ip_vs_state_name(cp->protocol, cp->state),
1126                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1127         }
1128         return 0;
1129 }
1130
1131 static const struct seq_operations ip_vs_conn_seq_ops = {
1132         .start = ip_vs_conn_seq_start,
1133         .next  = ip_vs_conn_seq_next,
1134         .stop  = ip_vs_conn_seq_stop,
1135         .show  = ip_vs_conn_seq_show,
1136 };
1137
1138 static int ip_vs_conn_open(struct inode *inode, struct file *file)
1139 {
1140         return seq_open_net(inode, file, &ip_vs_conn_seq_ops,
1141                             sizeof(struct ip_vs_iter_state));
1142 }
1143
1144 static const struct file_operations ip_vs_conn_fops = {
1145         .owner   = THIS_MODULE,
1146         .open    = ip_vs_conn_open,
1147         .read    = seq_read,
1148         .llseek  = seq_lseek,
1149         .release = seq_release_net,
1150 };
1151
1152 static const char *ip_vs_origin_name(unsigned int flags)
1153 {
1154         if (flags & IP_VS_CONN_F_SYNC)
1155                 return "SYNC";
1156         else
1157                 return "LOCAL";
1158 }
1159
1160 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1161 {
1162         char dbuf[IP_VS_ADDRSTRLEN];
1163
1164         if (v == SEQ_START_TOKEN)
1165                 seq_puts(seq,
1166    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
1167         else {
1168                 const struct ip_vs_conn *cp = v;
1169                 struct net *net = seq_file_net(seq);
1170
1171                 if (!net_eq(cp->ipvs->net, net))
1172                         return 0;
1173
1174 #ifdef CONFIG_IP_VS_IPV6
1175                 if (cp->daf == AF_INET6)
1176                         snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1177                 else
1178 #endif
1179                         snprintf(dbuf, sizeof(dbuf), "%08X",
1180                                  ntohl(cp->daddr.ip));
1181
1182 #ifdef CONFIG_IP_VS_IPV6
1183                 if (cp->af == AF_INET6)
1184                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1185                                 "%s %04X %-11s %-6s %7lu\n",
1186                                 ip_vs_proto_name(cp->protocol),
1187                                 &cp->caddr.in6, ntohs(cp->cport),
1188                                 &cp->vaddr.in6, ntohs(cp->vport),
1189                                 dbuf, ntohs(cp->dport),
1190                                 ip_vs_state_name(cp->protocol, cp->state),
1191                                 ip_vs_origin_name(cp->flags),
1192                                 (cp->timer.expires-jiffies)/HZ);
1193                 else
1194 #endif
1195                         seq_printf(seq,
1196                                 "%-3s %08X %04X %08X %04X "
1197                                 "%s %04X %-11s %-6s %7lu\n",
1198                                 ip_vs_proto_name(cp->protocol),
1199                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1200                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1201                                 dbuf, ntohs(cp->dport),
1202                                 ip_vs_state_name(cp->protocol, cp->state),
1203                                 ip_vs_origin_name(cp->flags),
1204                                 (cp->timer.expires-jiffies)/HZ);
1205         }
1206         return 0;
1207 }
1208
1209 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1210         .start = ip_vs_conn_seq_start,
1211         .next  = ip_vs_conn_seq_next,
1212         .stop  = ip_vs_conn_seq_stop,
1213         .show  = ip_vs_conn_sync_seq_show,
1214 };
1215
1216 static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
1217 {
1218         return seq_open_net(inode, file, &ip_vs_conn_sync_seq_ops,
1219                             sizeof(struct ip_vs_iter_state));
1220 }
1221
1222 static const struct file_operations ip_vs_conn_sync_fops = {
1223         .owner   = THIS_MODULE,
1224         .open    = ip_vs_conn_sync_open,
1225         .read    = seq_read,
1226         .llseek  = seq_lseek,
1227         .release = seq_release_net,
1228 };
1229
1230 #endif
1231
1232
1233 /*
1234  *      Randomly drop connection entries before running out of memory
1235  */
1236 static inline int todrop_entry(struct ip_vs_conn *cp)
1237 {
1238         /*
1239          * The drop rate array needs tuning for real environments.
1240          * Called from timer bh only => no locking
1241          */
1242         static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1243         static char todrop_counter[9] = {0};
1244         int i;
1245
1246         /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1247            This will leave enough time for normal connection to get
1248            through. */
1249         if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1250                 return 0;
1251
1252         /* Don't drop the entry if its number of incoming packets is not
1253            located in [0, 8] */
1254         i = atomic_read(&cp->in_pkts);
1255         if (i > 8 || i < 0) return 0;
1256
1257         if (!todrop_rate[i]) return 0;
1258         if (--todrop_counter[i] > 0) return 0;
1259
1260         todrop_counter[i] = todrop_rate[i];
1261         return 1;
1262 }
1263
1264 static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp)
1265 {
1266         struct ip_vs_service *svc;
1267
1268         if (!cp->dest)
1269                 return false;
1270         svc = rcu_dereference(cp->dest->svc);
1271         return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET);
1272 }
1273
1274 /* Called from keventd and must protect itself from softirqs */
1275 void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
1276 {
1277         int idx;
1278         struct ip_vs_conn *cp, *cp_c;
1279
1280         rcu_read_lock();
1281         /*
1282          * Randomly scan 1/32 of the whole table every second
1283          */
1284         for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1285                 unsigned int hash = prandom_u32() & ip_vs_conn_tab_mask;
1286
1287                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
1288                         if (cp->ipvs != ipvs)
1289                                 continue;
1290                         if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
1291                                 if (atomic_read(&cp->n_control) ||
1292                                     !ip_vs_conn_ops_mode(cp))
1293                                         continue;
1294                                 else
1295                                         /* connection template of OPS */
1296                                         goto try_drop;
1297                         }
1298                         if (cp->protocol == IPPROTO_TCP) {
1299                                 switch(cp->state) {
1300                                 case IP_VS_TCP_S_SYN_RECV:
1301                                 case IP_VS_TCP_S_SYNACK:
1302                                         break;
1303
1304                                 case IP_VS_TCP_S_ESTABLISHED:
1305                                         if (todrop_entry(cp))
1306                                                 break;
1307                                         continue;
1308
1309                                 default:
1310                                         continue;
1311                                 }
1312                         } else if (cp->protocol == IPPROTO_SCTP) {
1313                                 switch (cp->state) {
1314                                 case IP_VS_SCTP_S_INIT1:
1315                                 case IP_VS_SCTP_S_INIT:
1316                                         break;
1317                                 case IP_VS_SCTP_S_ESTABLISHED:
1318                                         if (todrop_entry(cp))
1319                                                 break;
1320                                         continue;
1321                                 default:
1322                                         continue;
1323                                 }
1324                         } else {
1325 try_drop:
1326                                 if (!todrop_entry(cp))
1327                                         continue;
1328                         }
1329
1330                         IP_VS_DBG(4, "del connection\n");
1331                         ip_vs_conn_expire_now(cp);
1332                         cp_c = cp->control;
1333                         /* cp->control is valid only with reference to cp */
1334                         if (cp_c && __ip_vs_conn_get(cp)) {
1335                                 IP_VS_DBG(4, "del conn template\n");
1336                                 ip_vs_conn_expire_now(cp_c);
1337                                 __ip_vs_conn_put(cp);
1338                         }
1339                 }
1340                 cond_resched_rcu();
1341         }
1342         rcu_read_unlock();
1343 }
1344
1345
1346 /*
1347  *      Flush all the connection entries in the ip_vs_conn_tab
1348  */
1349 static void ip_vs_conn_flush(struct netns_ipvs *ipvs)
1350 {
1351         int idx;
1352         struct ip_vs_conn *cp, *cp_c;
1353
1354 flush_again:
1355         rcu_read_lock();
1356         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1357
1358                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1359                         if (cp->ipvs != ipvs)
1360                                 continue;
1361                         IP_VS_DBG(4, "del connection\n");
1362                         ip_vs_conn_expire_now(cp);
1363                         cp_c = cp->control;
1364                         /* cp->control is valid only with reference to cp */
1365                         if (cp_c && __ip_vs_conn_get(cp)) {
1366                                 IP_VS_DBG(4, "del conn template\n");
1367                                 ip_vs_conn_expire_now(cp_c);
1368                                 __ip_vs_conn_put(cp);
1369                         }
1370                 }
1371                 cond_resched_rcu();
1372         }
1373         rcu_read_unlock();
1374
1375         /* the counter may be not NULL, because maybe some conn entries
1376            are run by slow timer handler or unhashed but still referred */
1377         if (atomic_read(&ipvs->conn_count) != 0) {
1378                 schedule();
1379                 goto flush_again;
1380         }
1381 }
1382 /*
1383  * per netns init and exit
1384  */
1385 int __net_init ip_vs_conn_net_init(struct netns_ipvs *ipvs)
1386 {
1387         atomic_set(&ipvs->conn_count, 0);
1388
1389         proc_create("ip_vs_conn", 0, ipvs->net->proc_net, &ip_vs_conn_fops);
1390         proc_create("ip_vs_conn_sync", 0, ipvs->net->proc_net,
1391                     &ip_vs_conn_sync_fops);
1392         return 0;
1393 }
1394
1395 void __net_exit ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs)
1396 {
1397         /* flush all the connection entries first */
1398         ip_vs_conn_flush(ipvs);
1399         remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
1400         remove_proc_entry("ip_vs_conn_sync", ipvs->net->proc_net);
1401 }
1402
1403 int __init ip_vs_conn_init(void)
1404 {
1405         int idx;
1406
1407         /* Compute size and mask */
1408         ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1409         ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1410
1411         /*
1412          * Allocate the connection hash table and initialize its list heads
1413          */
1414         ip_vs_conn_tab = vmalloc(ip_vs_conn_tab_size * sizeof(*ip_vs_conn_tab));
1415         if (!ip_vs_conn_tab)
1416                 return -ENOMEM;
1417
1418         /* Allocate ip_vs_conn slab cache */
1419         ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1420                                               sizeof(struct ip_vs_conn), 0,
1421                                               SLAB_HWCACHE_ALIGN, NULL);
1422         if (!ip_vs_conn_cachep) {
1423                 vfree(ip_vs_conn_tab);
1424                 return -ENOMEM;
1425         }
1426
1427         pr_info("Connection hash table configured "
1428                 "(size=%d, memory=%ldKbytes)\n",
1429                 ip_vs_conn_tab_size,
1430                 (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
1431         IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
1432                   sizeof(struct ip_vs_conn));
1433
1434         for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1435                 INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1436
1437         for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1438                 spin_lock_init(&__ip_vs_conntbl_lock_array[idx].l);
1439         }
1440
1441         /* calculate the random value for connection hash */
1442         get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1443
1444         return 0;
1445 }
1446
1447 void ip_vs_conn_cleanup(void)
1448 {
1449         /* Wait all ip_vs_conn_rcu_free() callbacks to complete */
1450         rcu_barrier();
1451         /* Release the empty cache */
1452         kmem_cache_destroy(ip_vs_conn_cachep);
1453         vfree(ip_vs_conn_tab);
1454 }