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/proc_fs.h>              /* for proc_net_* */
  30 #include <linux/slab.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/jhash.h>
  33 #include <linux/random.h>
  34
  35 #include <net/net_namespace.h>
  36 #include <net/ip_vs.h>
  37
  38
  39 #ifndef CONFIG_IP_VS_TAB_BITS
  40 #define CONFIG_IP_VS_TAB_BITS   12
  41 #endif
  42
  43 /*
  44  * Connection hash size. Default is what was selected at compile time.
  45 */
  46 static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
  47 module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
  48 MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
  49
  50 /* size and mask values */
  51 int ip_vs_conn_tab_size __read_mostly;
  52 static int ip_vs_conn_tab_mask __read_mostly;
  53
  54 /*
  55  *  Connection hash table: for input and output packets lookups of IPVS
  56  */
  57 static struct hlist_head *ip_vs_conn_tab __read_mostly;
  58
  59 /*  SLAB cache for IPVS connections */
  60 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
  61
  62 /*  counter for no client port connections */
  63 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
  64
  65 /* random value for IPVS connection hash */
  66 static unsigned int ip_vs_conn_rnd __read_mostly;
  67
  68 /*
  69  *  Fine locking granularity for big connection hash table
  70  */
  71 #define CT_LOCKARRAY_BITS  5
  72 #define CT_LOCKARRAY_SIZE  (1<<CT_LOCKARRAY_BITS)
  73 #define CT_LOCKARRAY_MASK  (CT_LOCKARRAY_SIZE-1)
  74
  75 /* We need an addrstrlen that works with or without v6 */
  76 #ifdef CONFIG_IP_VS_IPV6
  77 #define IP_VS_ADDRSTRLEN INET6_ADDRSTRLEN
  78 #else
  79 #define IP_VS_ADDRSTRLEN (8+1)
  80 #endif
  81
  82 struct ip_vs_aligned_lock
  83 {
  84         spinlock_t      l;
  85 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
  86
  87 /* lock array for conn table */
  88 static struct ip_vs_aligned_lock
  89 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
  90
  91 static inline void ct_write_lock_bh(unsigned int key)
  92 {
  93         spin_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  94 }
  95
  96 static inline void ct_write_unlock_bh(unsigned int key)
  97 {
  98         spin_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
  99 }
 100
 101 static void ip_vs_conn_expire(struct timer_list *t);
 102
 103 /*
 104  *      Returns hash value for IPVS connection entry
 105  */
 106 static unsigned int ip_vs_conn_hashkey(struct netns_ipvs *ipvs, int af, unsigned int proto,
 107                                        const union nf_inet_addr *addr,
 108                                        __be16 port)
 109 {
 110 #ifdef CONFIG_IP_VS_IPV6
 111         if (af == AF_INET6)
 112                 return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
 113                                     (__force u32)port, proto, ip_vs_conn_rnd) ^
 114                         ((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
 115 #endif
 116         return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
 117                             ip_vs_conn_rnd) ^
 118                 ((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
 119 }
 120
 121 static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p,
 122                                              bool inverse)
 123 {
 124         const union nf_inet_addr *addr;
 125         __be16 port;
 126
 127         if (p->pe_data && p->pe->hashkey_raw)
 128                 return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) &
 129                         ip_vs_conn_tab_mask;
 130
 131         if (likely(!inverse)) {
 132                 addr = p->caddr;
 133                 port = p->cport;
 134         } else {
 135                 addr = p->vaddr;
 136                 port = p->vport;
 137         }
 138
 139         return ip_vs_conn_hashkey(p->ipvs, p->af, p->protocol, addr, port);
 140 }
 141
 142 static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp)
 143 {
 144         struct ip_vs_conn_param p;
 145
 146         ip_vs_conn_fill_param(cp->ipvs, cp->af, cp->protocol,
 147                               &cp->caddr, cp->cport, NULL, 0, &p);
 148
 149         if (cp->pe) {
 150                 p.pe = cp->pe;
 151                 p.pe_data = cp->pe_data;
 152                 p.pe_data_len = cp->pe_data_len;
 153         }
 154
 155         return ip_vs_conn_hashkey_param(&p, false);
 156 }
 157
 158 /*
 159  *      Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port.
 160  *      returns bool success.
 161  */
 162 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
 163 {
 164         unsigned int hash;
 165         int ret;
 166
 167         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 168                 return 0;
 169
 170         /* Hash by protocol, client address and port */
 171         hash = ip_vs_conn_hashkey_conn(cp);
 172
 173         ct_write_lock_bh(hash);
 174         spin_lock(&cp->lock);
 175
 176         if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
 177                 cp->flags |= IP_VS_CONN_F_HASHED;
 178                 refcount_inc(&cp->refcnt);
 179                 hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]);
 180                 ret = 1;
 181         } else {
 182                 pr_err("%s(): request for already hashed, called from %pS\n",
 183                        __func__, __builtin_return_address(0));
 184                 ret = 0;
 185         }
 186
 187         spin_unlock(&cp->lock);
 188         ct_write_unlock_bh(hash);
 189
 190         return ret;
 191 }
 192
 193
 194 /*
 195  *      UNhashes ip_vs_conn from ip_vs_conn_tab.
 196  *      returns bool success. Caller should hold conn reference.
 197  */
 198 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
 199 {
 200         unsigned int hash;
 201         int ret;
 202
 203         /* unhash it and decrease its reference counter */
 204         hash = ip_vs_conn_hashkey_conn(cp);
 205
 206         ct_write_lock_bh(hash);
 207         spin_lock(&cp->lock);
 208
 209         if (cp->flags & IP_VS_CONN_F_HASHED) {
 210                 hlist_del_rcu(&cp->c_list);
 211                 cp->flags &= ~IP_VS_CONN_F_HASHED;
 212                 refcount_dec(&cp->refcnt);
 213                 ret = 1;
 214         } else
 215                 ret = 0;
 216
 217         spin_unlock(&cp->lock);
 218         ct_write_unlock_bh(hash);
 219
 220         return ret;
 221 }
 222
 223 /* Try to unlink ip_vs_conn from ip_vs_conn_tab.
 224  * returns bool success.
 225  */
 226 static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp)
 227 {
 228         unsigned int hash;
 229         bool ret = false;
 230
 231         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 232                 return refcount_dec_if_one(&cp->refcnt);
 233
 234         hash = ip_vs_conn_hashkey_conn(cp);
 235
 236         ct_write_lock_bh(hash);
 237         spin_lock(&cp->lock);
 238
 239         if (cp->flags & IP_VS_CONN_F_HASHED) {
 240                 /* Decrease refcnt and unlink conn only if we are last user */
 241                 if (refcount_dec_if_one(&cp->refcnt)) {
 242                         hlist_del_rcu(&cp->c_list);
 243                         cp->flags &= ~IP_VS_CONN_F_HASHED;
 244                         ret = true;
 245                 }
 246         }
 247
 248         spin_unlock(&cp->lock);
 249         ct_write_unlock_bh(hash);
 250
 251         return ret;
 252 }
 253
 254
 255 /*
 256  *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 257  *  Called for pkts coming from OUTside-to-INside.
 258  *      p->caddr, p->cport: pkt source address (foreign host)
 259  *      p->vaddr, p->vport: pkt dest address (load balancer)
 260  */
 261 static inline struct ip_vs_conn *
 262 __ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
 263 {
 264         unsigned int hash;
 265         struct ip_vs_conn *cp;
 266
 267         hash = ip_vs_conn_hashkey_param(p, false);
 268
 269         rcu_read_lock();
 270
 271         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 272                 if (p->cport == cp->cport && p->vport == cp->vport &&
 273                     cp->af == p->af &&
 274                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 275                     ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) &&
 276                     ((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
 277                     p->protocol == cp->protocol &&
 278                     cp->ipvs == p->ipvs) {
 279                         if (!__ip_vs_conn_get(cp))
 280                                 continue;
 281                         /* HIT */
 282                         rcu_read_unlock();
 283                         return cp;
 284                 }
 285         }
 286
 287         rcu_read_unlock();
 288
 289         return NULL;
 290 }
 291
 292 struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
 293 {
 294         struct ip_vs_conn *cp;
 295
 296         cp = __ip_vs_conn_in_get(p);
 297         if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) {
 298                 struct ip_vs_conn_param cport_zero_p = *p;
 299                 cport_zero_p.cport = 0;
 300                 cp = __ip_vs_conn_in_get(&cport_zero_p);
 301         }
 302
 303         IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
 304                       ip_vs_proto_name(p->protocol),
 305                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 306                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 307                       cp ? "hit" : "not hit");
 308
 309         return cp;
 310 }
 311
 312 static int
 313 ip_vs_conn_fill_param_proto(struct netns_ipvs *ipvs,
 314                             int af, const struct sk_buff *skb,
 315                             const struct ip_vs_iphdr *iph,
 316                             struct ip_vs_conn_param *p)
 317 {
 318         __be16 _ports[2], *pptr;
 319
 320         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports);
 321         if (pptr == NULL)
 322                 return 1;
 323
 324         if (likely(!ip_vs_iph_inverse(iph)))
 325                 ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->saddr,
 326                                       pptr[0], &iph->daddr, pptr[1], p);
 327         else
 328                 ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->daddr,
 329                                       pptr[1], &iph->saddr, pptr[0], p);
 330         return 0;
 331 }
 332
 333 struct ip_vs_conn *
 334 ip_vs_conn_in_get_proto(struct netns_ipvs *ipvs, int af,
 335                         const struct sk_buff *skb,
 336                         const struct ip_vs_iphdr *iph)
 337 {
 338         struct ip_vs_conn_param p;
 339
 340         if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
 341                 return NULL;
 342
 343         return ip_vs_conn_in_get(&p);
 344 }
 345 EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
 346
 347 /* Get reference to connection template */
 348 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
 349 {
 350         unsigned int hash;
 351         struct ip_vs_conn *cp;
 352
 353         hash = ip_vs_conn_hashkey_param(p, false);
 354
 355         rcu_read_lock();
 356
 357         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 358                 if (unlikely(p->pe_data && p->pe->ct_match)) {
 359                         if (cp->ipvs != p->ipvs)
 360                                 continue;
 361                         if (p->pe == cp->pe && p->pe->ct_match(p, cp)) {
 362                                 if (__ip_vs_conn_get(cp))
 363                                         goto out;
 364                         }
 365                         continue;
 366                 }
 367
 368                 if (cp->af == p->af &&
 369                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
 370                     /* protocol should only be IPPROTO_IP if
 371                      * p->vaddr is a fwmark */
 372                     ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
 373                                      p->af, p->vaddr, &cp->vaddr) &&
 374                     p->vport == cp->vport && p->cport == cp->cport &&
 375                     cp->flags & IP_VS_CONN_F_TEMPLATE &&
 376                     p->protocol == cp->protocol &&
 377                     cp->ipvs == p->ipvs) {
 378                         if (__ip_vs_conn_get(cp))
 379                                 goto out;
 380                 }
 381         }
 382         cp = NULL;
 383
 384   out:
 385         rcu_read_unlock();
 386
 387         IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
 388                       ip_vs_proto_name(p->protocol),
 389                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 390                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 391                       cp ? "hit" : "not hit");
 392
 393         return cp;
 394 }
 395
 396 /* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
 397  * Called for pkts coming from inside-to-OUTside.
 398  *      p->caddr, p->cport: pkt source address (inside host)
 399  *      p->vaddr, p->vport: pkt dest address (foreign host) */
 400 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
 401 {
 402         unsigned int hash;
 403         struct ip_vs_conn *cp, *ret=NULL;
 404         const union nf_inet_addr *saddr;
 405         __be16 sport;
 406
 407         /*
 408          *      Check for "full" addressed entries
 409          */
 410         hash = ip_vs_conn_hashkey_param(p, true);
 411
 412         rcu_read_lock();
 413
 414         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
 415                 if (p->vport != cp->cport)
 416                         continue;
 417
 418                 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
 419                         sport = cp->vport;
 420                         saddr = &cp->vaddr;
 421                 } else {
 422                         sport = cp->dport;
 423                         saddr = &cp->daddr;
 424                 }
 425
 426                 if (p->cport == sport && cp->af == p->af &&
 427                     ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
 428                     ip_vs_addr_equal(p->af, p->caddr, saddr) &&
 429                     p->protocol == cp->protocol &&
 430                     cp->ipvs == p->ipvs) {
 431                         if (!__ip_vs_conn_get(cp))
 432                                 continue;
 433                         /* HIT */
 434                         ret = cp;
 435                         break;
 436                 }
 437         }
 438
 439         rcu_read_unlock();
 440
 441         IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
 442                       ip_vs_proto_name(p->protocol),
 443                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
 444                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
 445                       ret ? "hit" : "not hit");
 446
 447         return ret;
 448 }
 449
 450 struct ip_vs_conn *
 451 ip_vs_conn_out_get_proto(struct netns_ipvs *ipvs, int af,
 452                          const struct sk_buff *skb,
 453                          const struct ip_vs_iphdr *iph)
 454 {
 455         struct ip_vs_conn_param p;
 456
 457         if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
 458                 return NULL;
 459
 460         return ip_vs_conn_out_get(&p);
 461 }
 462 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
 463
 464 /*
 465  *      Put back the conn and restart its timer with its timeout
 466  */
 467 static void __ip_vs_conn_put_timer(struct ip_vs_conn *cp)
 468 {
 469         unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
 470                 0 : cp->timeout;
 471         mod_timer(&cp->timer, jiffies+t);
 472
 473         __ip_vs_conn_put(cp);
 474 }
 475
 476 void ip_vs_conn_put(struct ip_vs_conn *cp)
 477 {
 478         if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) &&
 479             (refcount_read(&cp->refcnt) == 1) &&
 480             !timer_pending(&cp->timer))
 481                 /* expire connection immediately */
 482                 ip_vs_conn_expire(&cp->timer);
 483         else
 484                 __ip_vs_conn_put_timer(cp);
 485 }
 486
 487 /*
 488  *      Fill a no_client_port connection with a client port number
 489  */
 490 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
 491 {
 492         if (ip_vs_conn_unhash(cp)) {
 493                 spin_lock_bh(&cp->lock);
 494                 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
 495                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 496                         cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
 497                         cp->cport = cport;
 498                 }
 499                 spin_unlock_bh(&cp->lock);
 500
 501                 /* hash on new dport */
 502                 ip_vs_conn_hash(cp);
 503         }
 504 }
 505
 506
 507 /*
 508  *      Bind a connection entry with the corresponding packet_xmit.
 509  *      Called by ip_vs_conn_new.
 510  */
 511 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
 512 {
 513         switch (IP_VS_FWD_METHOD(cp)) {
 514         case IP_VS_CONN_F_MASQ:
 515                 cp->packet_xmit = ip_vs_nat_xmit;
 516                 break;
 517
 518         case IP_VS_CONN_F_TUNNEL:
 519 #ifdef CONFIG_IP_VS_IPV6
 520                 if (cp->daf == AF_INET6)
 521                         cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 522                 else
 523 #endif
 524                         cp->packet_xmit = ip_vs_tunnel_xmit;
 525                 break;
 526
 527         case IP_VS_CONN_F_DROUTE:
 528                 cp->packet_xmit = ip_vs_dr_xmit;
 529                 break;
 530
 531         case IP_VS_CONN_F_LOCALNODE:
 532                 cp->packet_xmit = ip_vs_null_xmit;
 533                 break;
 534
 535         case IP_VS_CONN_F_BYPASS:
 536                 cp->packet_xmit = ip_vs_bypass_xmit;
 537                 break;
 538         }
 539 }
 540
 541 #ifdef CONFIG_IP_VS_IPV6
 542 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
 543 {
 544         switch (IP_VS_FWD_METHOD(cp)) {
 545         case IP_VS_CONN_F_MASQ:
 546                 cp->packet_xmit = ip_vs_nat_xmit_v6;
 547                 break;
 548
 549         case IP_VS_CONN_F_TUNNEL:
 550                 if (cp->daf == AF_INET6)
 551                         cp->packet_xmit = ip_vs_tunnel_xmit_v6;
 552                 else
 553                         cp->packet_xmit = ip_vs_tunnel_xmit;
 554                 break;
 555
 556         case IP_VS_CONN_F_DROUTE:
 557                 cp->packet_xmit = ip_vs_dr_xmit_v6;
 558                 break;
 559
 560         case IP_VS_CONN_F_LOCALNODE:
 561                 cp->packet_xmit = ip_vs_null_xmit;
 562                 break;
 563
 564         case IP_VS_CONN_F_BYPASS:
 565                 cp->packet_xmit = ip_vs_bypass_xmit_v6;
 566                 break;
 567         }
 568 }
 569 #endif
 570
 571
 572 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
 573 {
 574         return atomic_read(&dest->activeconns)
 575                 + atomic_read(&dest->inactconns);
 576 }
 577
 578 /*
 579  *      Bind a connection entry with a virtual service destination
 580  *      Called just after a new connection entry is created.
 581  */
 582 static inline void
 583 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
 584 {
 585         unsigned int conn_flags;
 586         __u32 flags;
 587
 588         /* if dest is NULL, then return directly */
 589         if (!dest)
 590                 return;
 591
 592         /* Increase the refcnt counter of the dest */
 593         ip_vs_dest_hold(dest);
 594
 595         conn_flags = atomic_read(&dest->conn_flags);
 596         if (cp->protocol != IPPROTO_UDP)
 597                 conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
 598         flags = cp->flags;
 599         /* Bind with the destination and its corresponding transmitter */
 600         if (flags & IP_VS_CONN_F_SYNC) {
 601                 /* if the connection is not template and is created
 602                  * by sync, preserve the activity flag.
 603                  */
 604                 if (!(flags & IP_VS_CONN_F_TEMPLATE))
 605                         conn_flags &= ~IP_VS_CONN_F_INACTIVE;
 606                 /* connections inherit forwarding method from dest */
 607                 flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
 608         }
 609         flags |= conn_flags;
 610         cp->flags = flags;
 611         cp->dest = dest;
 612
 613         IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
 614                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 615                       "dest->refcnt:%d\n",
 616                       ip_vs_proto_name(cp->protocol),
 617                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 618                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 619                       IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
 620                       ip_vs_fwd_tag(cp), cp->state,
 621                       cp->flags, refcount_read(&cp->refcnt),
 622                       refcount_read(&dest->refcnt));
 623
 624         /* Update the connection counters */
 625         if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
 626                 /* It is a normal connection, so modify the counters
 627                  * according to the flags, later the protocol can
 628                  * update them on state change
 629                  */
 630                 if (!(flags & IP_VS_CONN_F_INACTIVE))
 631                         atomic_inc(&dest->activeconns);
 632                 else
 633                         atomic_inc(&dest->inactconns);
 634         } else {
 635                 /* It is a persistent connection/template, so increase
 636                    the persistent connection counter */
 637                 atomic_inc(&dest->persistconns);
 638         }
 639
 640         if (dest->u_threshold != 0 &&
 641             ip_vs_dest_totalconns(dest) >= dest->u_threshold)
 642                 dest->flags |= IP_VS_DEST_F_OVERLOAD;
 643 }
 644
 645
 646 /*
 647  * Check if there is a destination for the connection, if so
 648  * bind the connection to the destination.
 649  */
 650 void ip_vs_try_bind_dest(struct ip_vs_conn *cp)
 651 {
 652         struct ip_vs_dest *dest;
 653
 654         rcu_read_lock();
 655
 656         /* This function is only invoked by the synchronization code. We do
 657          * not currently support heterogeneous pools with synchronization,
 658          * so we can make the assumption that the svc_af is the same as the
 659          * dest_af
 660          */
 661         dest = ip_vs_find_dest(cp->ipvs, cp->af, cp->af, &cp->daddr,
 662                                cp->dport, &cp->vaddr, cp->vport,
 663                                cp->protocol, cp->fwmark, cp->flags);
 664         if (dest) {
 665                 struct ip_vs_proto_data *pd;
 666
 667                 spin_lock_bh(&cp->lock);
 668                 if (cp->dest) {
 669                         spin_unlock_bh(&cp->lock);
 670                         rcu_read_unlock();
 671                         return;
 672                 }
 673
 674                 /* Applications work depending on the forwarding method
 675                  * but better to reassign them always when binding dest */
 676                 if (cp->app)
 677                         ip_vs_unbind_app(cp);
 678
 679                 ip_vs_bind_dest(cp, dest);
 680                 spin_unlock_bh(&cp->lock);
 681
 682                 /* Update its packet transmitter */
 683                 cp->packet_xmit = NULL;
 684 #ifdef CONFIG_IP_VS_IPV6
 685                 if (cp->af == AF_INET6)
 686                         ip_vs_bind_xmit_v6(cp);
 687                 else
 688 #endif
 689                         ip_vs_bind_xmit(cp);
 690
 691                 pd = ip_vs_proto_data_get(cp->ipvs, cp->protocol);
 692                 if (pd && atomic_read(&pd->appcnt))
 693                         ip_vs_bind_app(cp, pd->pp);
 694         }
 695         rcu_read_unlock();
 696 }
 697
 698
 699 /*
 700  *      Unbind a connection entry with its VS destination
 701  *      Called by the ip_vs_conn_expire function.
 702  */
 703 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
 704 {
 705         struct ip_vs_dest *dest = cp->dest;
 706
 707         if (!dest)
 708                 return;
 709
 710         IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
 711                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
 712                       "dest->refcnt:%d\n",
 713                       ip_vs_proto_name(cp->protocol),
 714                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
 715                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
 716                       IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
 717                       ip_vs_fwd_tag(cp), cp->state,
 718                       cp->flags, refcount_read(&cp->refcnt),
 719                       refcount_read(&dest->refcnt));
 720
 721         /* Update the connection counters */
 722         if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
 723                 /* It is a normal connection, so decrease the inactconns
 724                    or activeconns counter */
 725                 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
 726                         atomic_dec(&dest->inactconns);
 727                 } else {
 728                         atomic_dec(&dest->activeconns);
 729                 }
 730         } else {
 731                 /* It is a persistent connection/template, so decrease
 732                    the persistent connection counter */
 733                 atomic_dec(&dest->persistconns);
 734         }
 735
 736         if (dest->l_threshold != 0) {
 737                 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
 738                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 739         } else if (dest->u_threshold != 0) {
 740                 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
 741                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 742         } else {
 743                 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
 744                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
 745         }
 746
 747         ip_vs_dest_put(dest);
 748 }
 749
 750 static int expire_quiescent_template(struct netns_ipvs *ipvs,
 751                                      struct ip_vs_dest *dest)
 752 {
 753 #ifdef CONFIG_SYSCTL
 754         return ipvs->sysctl_expire_quiescent_template &&
 755                 (atomic_read(&dest->weight) == 0);
 756 #else
 757         return 0;
 758 #endif
 759 }
 760
 761 /*
 762  *      Checking if the destination of a connection template is available.
 763  *      If available, return 1, otherwise invalidate this connection
 764  *      template and return 0.
 765  */
 766 int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest)
 767 {
 768         struct ip_vs_dest *dest = ct->dest;
 769         struct netns_ipvs *ipvs = ct->ipvs;
 770
 771         /*
 772          * Checking the dest server status.
 773          */
 774         if ((dest == NULL) ||
 775             !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
 776             expire_quiescent_template(ipvs, dest) ||
 777             (cdest && (dest != cdest))) {
 778                 IP_VS_DBG_BUF(9, "check_template: dest not available for "
 779                               "protocol %s s:%s:%d v:%s:%d "
 780                               "-> d:%s:%d\n",
 781                               ip_vs_proto_name(ct->protocol),
 782                               IP_VS_DBG_ADDR(ct->af, &ct->caddr),
 783                               ntohs(ct->cport),
 784                               IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
 785                               ntohs(ct->vport),
 786                               IP_VS_DBG_ADDR(ct->daf, &ct->daddr),
 787                               ntohs(ct->dport));
 788
 789                 /*
 790                  * Invalidate the connection template
 791                  */
 792                 if (ct->vport != htons(0xffff)) {
 793                         if (ip_vs_conn_unhash(ct)) {
 794                                 ct->dport = htons(0xffff);
 795                                 ct->vport = htons(0xffff);
 796                                 ct->cport = 0;
 797                                 ip_vs_conn_hash(ct);
 798                         }
 799                 }
 800
 801                 /*
 802                  * Simply decrease the refcnt of the template,
 803                  * don't restart its timer.
 804                  */
 805                 __ip_vs_conn_put(ct);
 806                 return 0;
 807         }
 808         return 1;
 809 }
 810
 811 static void ip_vs_conn_rcu_free(struct rcu_head *head)
 812 {
 813         struct ip_vs_conn *cp = container_of(head, struct ip_vs_conn,
 814                                              rcu_head);
 815
 816         ip_vs_pe_put(cp->pe);
 817         kfree(cp->pe_data);
 818         kmem_cache_free(ip_vs_conn_cachep, cp);
 819 }
 820
 821 /* Try to delete connection while not holding reference */
 822 static void ip_vs_conn_del(struct ip_vs_conn *cp)
 823 {
 824         if (del_timer(&cp->timer)) {
 825                 /* Drop cp->control chain too */
 826                 if (cp->control)
 827                         cp->timeout = 0;
 828                 ip_vs_conn_expire(&cp->timer);
 829         }
 830 }
 831
 832 /* Try to delete connection while holding reference */
 833 static void ip_vs_conn_del_put(struct ip_vs_conn *cp)
 834 {
 835         if (del_timer(&cp->timer)) {
 836                 /* Drop cp->control chain too */
 837                 if (cp->control)
 838                         cp->timeout = 0;
 839                 __ip_vs_conn_put(cp);
 840                 ip_vs_conn_expire(&cp->timer);
 841         } else {
 842                 __ip_vs_conn_put(cp);
 843         }
 844 }
 845
 846 static void ip_vs_conn_expire(struct timer_list *t)
 847 {
 848         struct ip_vs_conn *cp = from_timer(cp, t, timer);
 849         struct netns_ipvs *ipvs = cp->ipvs;
 850
 851         /*
 852          *      do I control anybody?
 853          */
 854         if (atomic_read(&cp->n_control))
 855                 goto expire_later;
 856
 857         /* Unlink conn if not referenced anymore */
 858         if (likely(ip_vs_conn_unlink(cp))) {
 859                 struct ip_vs_conn *ct = cp->control;
 860
 861                 /* delete the timer if it is activated by other users */
 862                 del_timer(&cp->timer);
 863
 864                 /* does anybody control me? */
 865                 if (ct) {
 866                         bool has_ref = !cp->timeout && __ip_vs_conn_get(ct);
 867
 868                         ip_vs_control_del(cp);
 869                         /* Drop CTL or non-assured TPL if not used anymore */
 870                         if (has_ref && !atomic_read(&ct->n_control) &&
 871                             (!(ct->flags & IP_VS_CONN_F_TEMPLATE) ||
 872                              !(ct->state & IP_VS_CTPL_S_ASSURED))) {
 873                                 IP_VS_DBG(4, "drop controlling connection\n");
 874                                 ip_vs_conn_del_put(ct);
 875                         } else if (has_ref) {
 876                                 __ip_vs_conn_put(ct);
 877                         }
 878                 }
 879
 880                 if ((cp->flags & IP_VS_CONN_F_NFCT) &&
 881                     !(cp->flags & IP_VS_CONN_F_ONE_PACKET)) {
 882                         /* Do not access conntracks during subsys cleanup
 883                          * because nf_conntrack_find_get can not be used after
 884                          * conntrack cleanup for the net.
 885                          */
 886                         smp_rmb();
 887                         if (ipvs->enable)
 888                                 ip_vs_conn_drop_conntrack(cp);
 889                 }
 890
 891                 if (unlikely(cp->app != NULL))
 892                         ip_vs_unbind_app(cp);
 893                 ip_vs_unbind_dest(cp);
 894                 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
 895                         atomic_dec(&ip_vs_conn_no_cport_cnt);
 896                 if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
 897                         ip_vs_conn_rcu_free(&cp->rcu_head);
 898                 else
 899                         call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
 900                 atomic_dec(&ipvs->conn_count);
 901                 return;
 902         }
 903
 904   expire_later:
 905         IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
 906                   refcount_read(&cp->refcnt),
 907                   atomic_read(&cp->n_control));
 908
 909         refcount_inc(&cp->refcnt);
 910         cp->timeout = 60*HZ;
 911
 912         if (ipvs->sync_state & IP_VS_STATE_MASTER)
 913                 ip_vs_sync_conn(ipvs, cp, sysctl_sync_threshold(ipvs));
 914
 915         __ip_vs_conn_put_timer(cp);
 916 }
 917
 918 /* Modify timer, so that it expires as soon as possible.
 919  * Can be called without reference only if under RCU lock.
 920  * We can have such chain of conns linked with ->control: DATA->CTL->TPL
 921  * - DATA (eg. FTP) and TPL (persistence) can be present depending on setup
 922  * - cp->timeout=0 indicates all conns from chain should be dropped but
 923  * TPL is not dropped if in assured state
 924  */
 925 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
 926 {
 927         /* Using mod_timer_pending will ensure the timer is not
 928          * modified after the final del_timer in ip_vs_conn_expire.
 929          */
 930         if (timer_pending(&cp->timer) &&
 931             time_after(cp->timer.expires, jiffies))
 932                 mod_timer_pending(&cp->timer, jiffies);
 933 }
 934
 935
 936 /*
 937  *      Create a new connection entry and hash it into the ip_vs_conn_tab
 938  */
 939 struct ip_vs_conn *
 940 ip_vs_conn_new(const struct ip_vs_conn_param *p, int dest_af,
 941                const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
 942                struct ip_vs_dest *dest, __u32 fwmark)
 943 {
 944         struct ip_vs_conn *cp;
 945         struct netns_ipvs *ipvs = p->ipvs;
 946         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->ipvs,
 947                                                            p->protocol);
 948
 949         cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
 950         if (cp == NULL) {
 951                 IP_VS_ERR_RL("%s(): no memory\n", __func__);
 952                 return NULL;
 953         }
 954
 955         INIT_HLIST_NODE(&cp->c_list);
 956         timer_setup(&cp->timer, ip_vs_conn_expire, 0);
 957         cp->ipvs           = ipvs;
 958         cp->af             = p->af;
 959         cp->daf            = dest_af;
 960         cp->protocol       = p->protocol;
 961         ip_vs_addr_set(p->af, &cp->caddr, p->caddr);
 962         cp->cport          = p->cport;
 963         /* proto should only be IPPROTO_IP if p->vaddr is a fwmark */
 964         ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
 965                        &cp->vaddr, p->vaddr);
 966         cp->vport          = p->vport;
 967         ip_vs_addr_set(cp->daf, &cp->daddr, daddr);
 968         cp->dport          = dport;
 969         cp->flags          = flags;
 970         cp->fwmark         = fwmark;
 971         if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
 972                 ip_vs_pe_get(p->pe);
 973                 cp->pe = p->pe;
 974                 cp->pe_data = p->pe_data;
 975                 cp->pe_data_len = p->pe_data_len;
 976         } else {
 977                 cp->pe = NULL;
 978                 cp->pe_data = NULL;
 979                 cp->pe_data_len = 0;
 980         }
 981         spin_lock_init(&cp->lock);
 982
 983         /*
 984          * Set the entry is referenced by the current thread before hashing
 985          * it in the table, so that other thread run ip_vs_random_dropentry
 986          * but cannot drop this entry.
 987          */
 988         refcount_set(&cp->refcnt, 1);
 989
 990         cp->control = NULL;
 991         atomic_set(&cp->n_control, 0);
 992         atomic_set(&cp->in_pkts, 0);
 993
 994         cp->packet_xmit = NULL;
 995         cp->app = NULL;
 996         cp->app_data = NULL;
 997         /* reset struct ip_vs_seq */
 998         cp->in_seq.delta = 0;
 999         cp->out_seq.delta = 0;
1000
1001         atomic_inc(&ipvs->conn_count);
1002         if (flags & IP_VS_CONN_F_NO_CPORT)
1003                 atomic_inc(&ip_vs_conn_no_cport_cnt);
1004
1005         /* Bind the connection with a destination server */
1006         cp->dest = NULL;
1007         ip_vs_bind_dest(cp, dest);
1008
1009         /* Set its state and timeout */
1010         cp->state = 0;
1011         cp->old_state = 0;
1012         cp->timeout = 3*HZ;
1013         cp->sync_endtime = jiffies & ~3UL;
1014
1015         /* Bind its packet transmitter */
1016 #ifdef CONFIG_IP_VS_IPV6
1017         if (p->af == AF_INET6)
1018                 ip_vs_bind_xmit_v6(cp);
1019         else
1020 #endif
1021                 ip_vs_bind_xmit(cp);
1022
1023         if (unlikely(pd && atomic_read(&pd->appcnt)))
1024                 ip_vs_bind_app(cp, pd->pp);
1025
1026         /*
1027          * Allow conntrack to be preserved. By default, conntrack
1028          * is created and destroyed for every packet.
1029          * Sometimes keeping conntrack can be useful for
1030          * IP_VS_CONN_F_ONE_PACKET too.
1031          */
1032
1033         if (ip_vs_conntrack_enabled(ipvs))
1034                 cp->flags |= IP_VS_CONN_F_NFCT;
1035
1036         /* Hash it in the ip_vs_conn_tab finally */
1037         ip_vs_conn_hash(cp);
1038
1039         return cp;
1040 }
1041
1042 /*
1043  *      /proc/net/ip_vs_conn entries
1044  */
1045 #ifdef CONFIG_PROC_FS
1046 struct ip_vs_iter_state {
1047         struct seq_net_private  p;
1048         struct hlist_head       *l;
1049 };
1050
1051 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
1052 {
1053         int idx;
1054         struct ip_vs_conn *cp;
1055         struct ip_vs_iter_state *iter = seq->private;
1056
1057         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1058                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1059                         /* __ip_vs_conn_get() is not needed by
1060                          * ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show
1061                          */
1062                         if (pos-- == 0) {
1063                                 iter->l = &ip_vs_conn_tab[idx];
1064                                 return cp;
1065                         }
1066                 }
1067                 cond_resched_rcu();
1068         }
1069
1070         return NULL;
1071 }
1072
1073 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
1074         __acquires(RCU)
1075 {
1076         struct ip_vs_iter_state *iter = seq->private;
1077
1078         iter->l = NULL;
1079         rcu_read_lock();
1080         return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
1081 }
1082
1083 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1084 {
1085         struct ip_vs_conn *cp = v;
1086         struct ip_vs_iter_state *iter = seq->private;
1087         struct hlist_node *e;
1088         struct hlist_head *l = iter->l;
1089         int idx;
1090
1091         ++*pos;
1092         if (v == SEQ_START_TOKEN)
1093                 return ip_vs_conn_array(seq, 0);
1094
1095         /* more on same hash chain? */
1096         e = rcu_dereference(hlist_next_rcu(&cp->c_list));
1097         if (e)
1098                 return hlist_entry(e, struct ip_vs_conn, c_list);
1099
1100         idx = l - ip_vs_conn_tab;
1101         while (++idx < ip_vs_conn_tab_size) {
1102                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1103                         iter->l = &ip_vs_conn_tab[idx];
1104                         return cp;
1105                 }
1106                 cond_resched_rcu();
1107         }
1108         iter->l = NULL;
1109         return NULL;
1110 }
1111
1112 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1113         __releases(RCU)
1114 {
1115         rcu_read_unlock();
1116 }
1117
1118 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1119 {
1120
1121         if (v == SEQ_START_TOKEN)
1122                 seq_puts(seq,
1123    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires PEName PEData\n");
1124         else {
1125                 const struct ip_vs_conn *cp = v;
1126                 struct net *net = seq_file_net(seq);
1127                 char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1128                 size_t len = 0;
1129                 char dbuf[IP_VS_ADDRSTRLEN];
1130
1131                 if (!net_eq(cp->ipvs->net, net))
1132                         return 0;
1133                 if (cp->pe_data) {
1134                         pe_data[0] = ' ';
1135                         len = strlen(cp->pe->name);
1136                         memcpy(pe_data + 1, cp->pe->name, len);
1137                         pe_data[len + 1] = ' ';
1138                         len += 2;
1139                         len += cp->pe->show_pe_data(cp, pe_data + len);
1140                 }
1141                 pe_data[len] = '\0';
1142
1143 #ifdef CONFIG_IP_VS_IPV6
1144                 if (cp->daf == AF_INET6)
1145                         snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1146                 else
1147 #endif
1148                         snprintf(dbuf, sizeof(dbuf), "%08X",
1149                                  ntohl(cp->daddr.ip));
1150
1151 #ifdef CONFIG_IP_VS_IPV6
1152                 if (cp->af == AF_INET6)
1153                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1154                                 "%s %04X %-11s %7u%s\n",
1155                                 ip_vs_proto_name(cp->protocol),
1156                                 &cp->caddr.in6, ntohs(cp->cport),
1157                                 &cp->vaddr.in6, ntohs(cp->vport),
1158                                 dbuf, ntohs(cp->dport),
1159                                 ip_vs_state_name(cp),
1160                                 jiffies_delta_to_msecs(cp->timer.expires -
1161                                                        jiffies) / 1000,
1162                                 pe_data);
1163                 else
1164 #endif
1165                         seq_printf(seq,
1166                                 "%-3s %08X %04X %08X %04X"
1167                                 " %s %04X %-11s %7u%s\n",
1168                                 ip_vs_proto_name(cp->protocol),
1169                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1170                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1171                                 dbuf, ntohs(cp->dport),
1172                                 ip_vs_state_name(cp),
1173                                 jiffies_delta_to_msecs(cp->timer.expires -
1174                                                        jiffies) / 1000,
1175                                 pe_data);
1176         }
1177         return 0;
1178 }
1179
1180 static const struct seq_operations ip_vs_conn_seq_ops = {
1181         .start = ip_vs_conn_seq_start,
1182         .next  = ip_vs_conn_seq_next,
1183         .stop  = ip_vs_conn_seq_stop,
1184         .show  = ip_vs_conn_seq_show,
1185 };
1186
1187 static const char *ip_vs_origin_name(unsigned int flags)
1188 {
1189         if (flags & IP_VS_CONN_F_SYNC)
1190                 return "SYNC";
1191         else
1192                 return "LOCAL";
1193 }
1194
1195 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1196 {
1197         char dbuf[IP_VS_ADDRSTRLEN];
1198
1199         if (v == SEQ_START_TOKEN)
1200                 seq_puts(seq,
1201    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
1202         else {
1203                 const struct ip_vs_conn *cp = v;
1204                 struct net *net = seq_file_net(seq);
1205
1206                 if (!net_eq(cp->ipvs->net, net))
1207                         return 0;
1208
1209 #ifdef CONFIG_IP_VS_IPV6
1210                 if (cp->daf == AF_INET6)
1211                         snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1212                 else
1213 #endif
1214                         snprintf(dbuf, sizeof(dbuf), "%08X",
1215                                  ntohl(cp->daddr.ip));
1216
1217 #ifdef CONFIG_IP_VS_IPV6
1218                 if (cp->af == AF_INET6)
1219                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1220                                 "%s %04X %-11s %-6s %7u\n",
1221                                 ip_vs_proto_name(cp->protocol),
1222                                 &cp->caddr.in6, ntohs(cp->cport),
1223                                 &cp->vaddr.in6, ntohs(cp->vport),
1224                                 dbuf, ntohs(cp->dport),
1225                                 ip_vs_state_name(cp),
1226                                 ip_vs_origin_name(cp->flags),
1227                                 jiffies_delta_to_msecs(cp->timer.expires -
1228                                                        jiffies) / 1000);
1229                 else
1230 #endif
1231                         seq_printf(seq,
1232                                 "%-3s %08X %04X %08X %04X "
1233                                 "%s %04X %-11s %-6s %7u\n",
1234                                 ip_vs_proto_name(cp->protocol),
1235                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1236                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1237                                 dbuf, ntohs(cp->dport),
1238                                 ip_vs_state_name(cp),
1239                                 ip_vs_origin_name(cp->flags),
1240                                 jiffies_delta_to_msecs(cp->timer.expires -
1241                                                        jiffies) / 1000);
1242         }
1243         return 0;
1244 }
1245
1246 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1247         .start = ip_vs_conn_seq_start,
1248         .next  = ip_vs_conn_seq_next,
1249         .stop  = ip_vs_conn_seq_stop,
1250         .show  = ip_vs_conn_sync_seq_show,
1251 };
1252 #endif
1253
1254
1255 /* Randomly drop connection entries before running out of memory
1256  * Can be used for DATA and CTL conns. For TPL conns there are exceptions:
1257  * - traffic for services in OPS mode increases ct->in_pkts, so it is supported
1258  * - traffic for services not in OPS mode does not increase ct->in_pkts in
1259  * all cases, so it is not supported
1260  */
1261 static inline int todrop_entry(struct ip_vs_conn *cp)
1262 {
1263         /*
1264          * The drop rate array needs tuning for real environments.
1265          * Called from timer bh only => no locking
1266          */
1267         static const signed char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1268         static signed char todrop_counter[9] = {0};
1269         int i;
1270
1271         /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1272            This will leave enough time for normal connection to get
1273            through. */
1274         if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1275                 return 0;
1276
1277         /* Don't drop the entry if its number of incoming packets is not
1278            located in [0, 8] */
1279         i = atomic_read(&cp->in_pkts);
1280         if (i > 8 || i < 0) return 0;
1281
1282         if (!todrop_rate[i]) return 0;
1283         if (--todrop_counter[i] > 0) return 0;
1284
1285         todrop_counter[i] = todrop_rate[i];
1286         return 1;
1287 }
1288
1289 static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp)
1290 {
1291         struct ip_vs_service *svc;
1292
1293         if (!cp->dest)
1294                 return false;
1295         svc = rcu_dereference(cp->dest->svc);
1296         return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET);
1297 }
1298
1299 /* Called from keventd and must protect itself from softirqs */
1300 void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
1301 {
1302         int idx;
1303         struct ip_vs_conn *cp;
1304
1305         rcu_read_lock();
1306         /*
1307          * Randomly scan 1/32 of the whole table every second
1308          */
1309         for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1310                 unsigned int hash = get_random_u32() & ip_vs_conn_tab_mask;
1311
1312                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
1313                         if (cp->ipvs != ipvs)
1314                                 continue;
1315                         if (atomic_read(&cp->n_control))
1316                                 continue;
1317                         if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
1318                                 /* connection template of OPS */
1319                                 if (ip_vs_conn_ops_mode(cp))
1320                                         goto try_drop;
1321                                 if (!(cp->state & IP_VS_CTPL_S_ASSURED))
1322                                         goto drop;
1323                                 continue;
1324                         }
1325                         if (cp->protocol == IPPROTO_TCP) {
1326                                 switch(cp->state) {
1327                                 case IP_VS_TCP_S_SYN_RECV:
1328                                 case IP_VS_TCP_S_SYNACK:
1329                                         break;
1330
1331                                 case IP_VS_TCP_S_ESTABLISHED:
1332                                         if (todrop_entry(cp))
1333                                                 break;
1334                                         continue;
1335
1336                                 default:
1337                                         continue;
1338                                 }
1339                         } else if (cp->protocol == IPPROTO_SCTP) {
1340                                 switch (cp->state) {
1341                                 case IP_VS_SCTP_S_INIT1:
1342                                 case IP_VS_SCTP_S_INIT:
1343                                         break;
1344                                 case IP_VS_SCTP_S_ESTABLISHED:
1345                                         if (todrop_entry(cp))
1346                                                 break;
1347                                         continue;
1348                                 default:
1349                                         continue;
1350                                 }
1351                         } else {
1352 try_drop:
1353                                 if (!todrop_entry(cp))
1354                                         continue;
1355                         }
1356
1357 drop:
1358                         IP_VS_DBG(4, "drop connection\n");
1359                         ip_vs_conn_del(cp);
1360                 }
1361                 cond_resched_rcu();
1362         }
1363         rcu_read_unlock();
1364 }
1365
1366
1367 /*
1368  *      Flush all the connection entries in the ip_vs_conn_tab
1369  */
1370 static void ip_vs_conn_flush(struct netns_ipvs *ipvs)
1371 {
1372         int idx;
1373         struct ip_vs_conn *cp, *cp_c;
1374
1375 flush_again:
1376         rcu_read_lock();
1377         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1378
1379                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1380                         if (cp->ipvs != ipvs)
1381                                 continue;
1382                         if (atomic_read(&cp->n_control))
1383                                 continue;
1384                         cp_c = cp->control;
1385                         IP_VS_DBG(4, "del connection\n");
1386                         ip_vs_conn_del(cp);
1387                         if (cp_c && !atomic_read(&cp_c->n_control)) {
1388                                 IP_VS_DBG(4, "del controlling connection\n");
1389                                 ip_vs_conn_del(cp_c);
1390                         }
1391                 }
1392                 cond_resched_rcu();
1393         }
1394         rcu_read_unlock();
1395
1396         /* the counter may be not NULL, because maybe some conn entries
1397            are run by slow timer handler or unhashed but still referred */
1398         if (atomic_read(&ipvs->conn_count) != 0) {
1399                 schedule();
1400                 goto flush_again;
1401         }
1402 }
1403
1404 #ifdef CONFIG_SYSCTL
1405 void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs)
1406 {
1407         int idx;
1408         struct ip_vs_conn *cp, *cp_c;
1409         struct ip_vs_dest *dest;
1410
1411         rcu_read_lock();
1412         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1413                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1414                         if (cp->ipvs != ipvs)
1415                                 continue;
1416
1417                         dest = cp->dest;
1418                         if (!dest || (dest->flags & IP_VS_DEST_F_AVAILABLE))
1419                                 continue;
1420
1421                         if (atomic_read(&cp->n_control))
1422                                 continue;
1423
1424                         cp_c = cp->control;
1425                         IP_VS_DBG(4, "del connection\n");
1426                         ip_vs_conn_del(cp);
1427                         if (cp_c && !atomic_read(&cp_c->n_control)) {
1428                                 IP_VS_DBG(4, "del controlling connection\n");
1429                                 ip_vs_conn_del(cp_c);
1430                         }
1431                 }
1432                 cond_resched_rcu();
1433
1434                 /* netns clean up started, abort delayed work */
1435                 if (!ipvs->enable)
1436                         break;
1437         }
1438         rcu_read_unlock();
1439 }
1440 #endif
1441
1442 /*
1443  * per netns init and exit
1444  */
1445 int __net_init ip_vs_conn_net_init(struct netns_ipvs *ipvs)
1446 {
1447         atomic_set(&ipvs->conn_count, 0);
1448
1449 #ifdef CONFIG_PROC_FS
1450         if (!proc_create_net("ip_vs_conn", 0, ipvs->net->proc_net,
1451                              &ip_vs_conn_seq_ops,
1452                              sizeof(struct ip_vs_iter_state)))
1453                 goto err_conn;
1454
1455         if (!proc_create_net("ip_vs_conn_sync", 0, ipvs->net->proc_net,
1456                              &ip_vs_conn_sync_seq_ops,
1457                              sizeof(struct ip_vs_iter_state)))
1458                 goto err_conn_sync;
1459 #endif
1460
1461         return 0;
1462
1463 #ifdef CONFIG_PROC_FS
1464 err_conn_sync:
1465         remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
1466 err_conn:
1467         return -ENOMEM;
1468 #endif
1469 }
1470
1471 void __net_exit ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs)
1472 {
1473         /* flush all the connection entries first */
1474         ip_vs_conn_flush(ipvs);
1475 #ifdef CONFIG_PROC_FS
1476         remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
1477         remove_proc_entry("ip_vs_conn_sync", ipvs->net->proc_net);
1478 #endif
1479 }
1480
1481 int __init ip_vs_conn_init(void)
1482 {
1483         size_t tab_array_size;
1484         int max_avail;
1485 #if BITS_PER_LONG > 32
1486         int max = 27;
1487 #else
1488         int max = 20;
1489 #endif
1490         int min = 8;
1491         int idx;
1492
1493         max_avail = order_base_2(totalram_pages()) + PAGE_SHIFT;
1494         max_avail -= 2;         /* ~4 in hash row */
1495         max_avail -= 1;         /* IPVS up to 1/2 of mem */
1496         max_avail -= order_base_2(sizeof(struct ip_vs_conn));
1497         max = clamp(max, min, max_avail);
1498         ip_vs_conn_tab_bits = clamp_val(ip_vs_conn_tab_bits, min, max);
1499         ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1500         ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1501
1502         /*
1503          * Allocate the connection hash table and initialize its list heads
1504          */
1505         tab_array_size = array_size(ip_vs_conn_tab_size,
1506                                     sizeof(*ip_vs_conn_tab));
1507         ip_vs_conn_tab = kvmalloc_array(ip_vs_conn_tab_size,
1508                                         sizeof(*ip_vs_conn_tab), GFP_KERNEL);
1509         if (!ip_vs_conn_tab)
1510                 return -ENOMEM;
1511
1512         /* Allocate ip_vs_conn slab cache */
1513         ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1514                                               sizeof(struct ip_vs_conn), 0,
1515                                               SLAB_HWCACHE_ALIGN, NULL);
1516         if (!ip_vs_conn_cachep) {
1517                 kvfree(ip_vs_conn_tab);
1518                 return -ENOMEM;
1519         }
1520
1521         pr_info("Connection hash table configured (size=%d, memory=%zdKbytes)\n",
1522                 ip_vs_conn_tab_size, tab_array_size / 1024);
1523         IP_VS_DBG(0, "Each connection entry needs %zd bytes at least\n",
1524                   sizeof(struct ip_vs_conn));
1525
1526         for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1527                 INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1528
1529         for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1530                 spin_lock_init(&__ip_vs_conntbl_lock_array[idx].l);
1531         }
1532
1533         /* calculate the random value for connection hash */
1534         get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1535
1536         return 0;
1537 }
1538
1539 void ip_vs_conn_cleanup(void)
1540 {
1541         /* Wait all ip_vs_conn_rcu_free() callbacks to complete */
1542         rcu_barrier();
1543         /* Release the empty cache */
1544         kmem_cache_destroy(ip_vs_conn_cachep);
1545         kvfree(ip_vs_conn_tab);
1546 }