net/netfilter/nf_conntrack_core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Connection state tracking for netfilter.  This is separated from,
   3    but required by, the NAT layer; it can also be used by an iptables
   4    extension. */
   5
   6 /* (C) 1999-2001 Paul `Rusty' Russell
   7  * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
   8  * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
   9  * (C) 2005-2012 Patrick McHardy <kaber@trash.net>
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/types.h>
  15 #include <linux/netfilter.h>
  16 #include <linux/module.h>
  17 #include <linux/sched.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/stddef.h>
  22 #include <linux/slab.h>
  23 #include <linux/random.h>
  24 #include <linux/jhash.h>
  25 #include <linux/siphash.h>
  26 #include <linux/err.h>
  27 #include <linux/percpu.h>
  28 #include <linux/moduleparam.h>
  29 #include <linux/notifier.h>
  30 #include <linux/kernel.h>
  31 #include <linux/netdevice.h>
  32 #include <linux/socket.h>
  33 #include <linux/mm.h>
  34 #include <linux/nsproxy.h>
  35 #include <linux/rculist_nulls.h>
  36
  37 #include <net/netfilter/nf_conntrack.h>
  38 #include <net/netfilter/nf_conntrack_l4proto.h>
  39 #include <net/netfilter/nf_conntrack_expect.h>
  40 #include <net/netfilter/nf_conntrack_helper.h>
  41 #include <net/netfilter/nf_conntrack_seqadj.h>
  42 #include <net/netfilter/nf_conntrack_core.h>
  43 #include <net/netfilter/nf_conntrack_extend.h>
  44 #include <net/netfilter/nf_conntrack_acct.h>
  45 #include <net/netfilter/nf_conntrack_ecache.h>
  46 #include <net/netfilter/nf_conntrack_zones.h>
  47 #include <net/netfilter/nf_conntrack_timestamp.h>
  48 #include <net/netfilter/nf_conntrack_timeout.h>
  49 #include <net/netfilter/nf_conntrack_labels.h>
  50 #include <net/netfilter/nf_conntrack_synproxy.h>
  51 #include <net/netfilter/nf_nat.h>
  52 #include <net/netfilter/nf_nat_helper.h>
  53 #include <net/netns/hash.h>
  54 #include <net/ip.h>
  55
  56 #include "nf_internals.h"
  57
  58 __cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
  59 EXPORT_SYMBOL_GPL(nf_conntrack_locks);
  60
  61 __cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
  62 EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
  63
  64 struct hlist_nulls_head *nf_conntrack_hash __read_mostly;
  65 EXPORT_SYMBOL_GPL(nf_conntrack_hash);
  66
  67 struct conntrack_gc_work {
  68         struct delayed_work     dwork;
  69         u32                     last_bucket;
  70         bool                    exiting;
  71         bool                    early_drop;
  72         long                    next_gc_run;
  73 };
  74
  75 static __read_mostly struct kmem_cache *nf_conntrack_cachep;
  76 static DEFINE_SPINLOCK(nf_conntrack_locks_all_lock);
  77 static __read_mostly bool nf_conntrack_locks_all;
  78
  79 /* every gc cycle scans at most 1/GC_MAX_BUCKETS_DIV part of table */
  80 #define GC_MAX_BUCKETS_DIV      128u
  81 /* upper bound of full table scan */
  82 #define GC_MAX_SCAN_JIFFIES     (16u * HZ)
  83 /* desired ratio of entries found to be expired */
  84 #define GC_EVICT_RATIO  50u
  85
  86 static struct conntrack_gc_work conntrack_gc_work;
  87
  88 void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
  89 {
  90         /* 1) Acquire the lock */
  91         spin_lock(lock);
  92
  93         /* 2) read nf_conntrack_locks_all, with ACQUIRE semantics
  94          * It pairs with the smp_store_release() in nf_conntrack_all_unlock()
  95          */
  96         if (likely(smp_load_acquire(&nf_conntrack_locks_all) == false))
  97                 return;
  98
  99         /* fast path failed, unlock */
 100         spin_unlock(lock);
 101
 102         /* Slow path 1) get global lock */
 103         spin_lock(&nf_conntrack_locks_all_lock);
 104
 105         /* Slow path 2) get the lock we want */
 106         spin_lock(lock);
 107
 108         /* Slow path 3) release the global lock */
 109         spin_unlock(&nf_conntrack_locks_all_lock);
 110 }
 111 EXPORT_SYMBOL_GPL(nf_conntrack_lock);
 112
 113 static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
 114 {
 115         h1 %= CONNTRACK_LOCKS;
 116         h2 %= CONNTRACK_LOCKS;
 117         spin_unlock(&nf_conntrack_locks[h1]);
 118         if (h1 != h2)
 119                 spin_unlock(&nf_conntrack_locks[h2]);
 120 }
 121
 122 /* return true if we need to recompute hashes (in case hash table was resized) */
 123 static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
 124                                      unsigned int h2, unsigned int sequence)
 125 {
 126         h1 %= CONNTRACK_LOCKS;
 127         h2 %= CONNTRACK_LOCKS;
 128         if (h1 <= h2) {
 129                 nf_conntrack_lock(&nf_conntrack_locks[h1]);
 130                 if (h1 != h2)
 131                         spin_lock_nested(&nf_conntrack_locks[h2],
 132                                          SINGLE_DEPTH_NESTING);
 133         } else {
 134                 nf_conntrack_lock(&nf_conntrack_locks[h2]);
 135                 spin_lock_nested(&nf_conntrack_locks[h1],
 136                                  SINGLE_DEPTH_NESTING);
 137         }
 138         if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
 139                 nf_conntrack_double_unlock(h1, h2);
 140                 return true;
 141         }
 142         return false;
 143 }
 144
 145 static void nf_conntrack_all_lock(void)
 146 {
 147         int i;
 148
 149         spin_lock(&nf_conntrack_locks_all_lock);
 150
 151         nf_conntrack_locks_all = true;
 152
 153         for (i = 0; i < CONNTRACK_LOCKS; i++) {
 154                 spin_lock(&nf_conntrack_locks[i]);
 155
 156                 /* This spin_unlock provides the "release" to ensure that
 157                  * nf_conntrack_locks_all==true is visible to everyone that
 158                  * acquired spin_lock(&nf_conntrack_locks[]).
 159                  */
 160                 spin_unlock(&nf_conntrack_locks[i]);
 161         }
 162 }
 163
 164 static void nf_conntrack_all_unlock(void)
 165 {
 166         /* All prior stores must be complete before we clear
 167          * 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
 168          * might observe the false value but not the entire
 169          * critical section.
 170          * It pairs with the smp_load_acquire() in nf_conntrack_lock()
 171          */
 172         smp_store_release(&nf_conntrack_locks_all, false);
 173         spin_unlock(&nf_conntrack_locks_all_lock);
 174 }
 175
 176 unsigned int nf_conntrack_htable_size __read_mostly;
 177 EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
 178
 179 unsigned int nf_conntrack_max __read_mostly;
 180 EXPORT_SYMBOL_GPL(nf_conntrack_max);
 181 seqcount_t nf_conntrack_generation __read_mostly;
 182 static unsigned int nf_conntrack_hash_rnd __read_mostly;
 183
 184 static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
 185                               const struct net *net)
 186 {
 187         unsigned int n;
 188         u32 seed;
 189
 190         get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
 191
 192         /* The direction must be ignored, so we hash everything up to the
 193          * destination ports (which is a multiple of 4) and treat the last
 194          * three bytes manually.
 195          */
 196         seed = nf_conntrack_hash_rnd ^ net_hash_mix(net);
 197         n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
 198         return jhash2((u32 *)tuple, n, seed ^
 199                       (((__force __u16)tuple->dst.u.all << 16) |
 200                       tuple->dst.protonum));
 201 }
 202
 203 static u32 scale_hash(u32 hash)
 204 {
 205         return reciprocal_scale(hash, nf_conntrack_htable_size);
 206 }
 207
 208 static u32 __hash_conntrack(const struct net *net,
 209                             const struct nf_conntrack_tuple *tuple,
 210                             unsigned int size)
 211 {
 212         return reciprocal_scale(hash_conntrack_raw(tuple, net), size);
 213 }
 214
 215 static u32 hash_conntrack(const struct net *net,
 216                           const struct nf_conntrack_tuple *tuple)
 217 {
 218         return scale_hash(hash_conntrack_raw(tuple, net));
 219 }
 220
 221 static bool nf_ct_get_tuple_ports(const struct sk_buff *skb,
 222                                   unsigned int dataoff,
 223                                   struct nf_conntrack_tuple *tuple)
 224 {       struct {
 225                 __be16 sport;
 226                 __be16 dport;
 227         } _inet_hdr, *inet_hdr;
 228
 229         /* Actually only need first 4 bytes to get ports. */
 230         inet_hdr = skb_header_pointer(skb, dataoff, sizeof(_inet_hdr), &_inet_hdr);
 231         if (!inet_hdr)
 232                 return false;
 233
 234         tuple->src.u.udp.port = inet_hdr->sport;
 235         tuple->dst.u.udp.port = inet_hdr->dport;
 236         return true;
 237 }
 238
 239 static bool
 240 nf_ct_get_tuple(const struct sk_buff *skb,
 241                 unsigned int nhoff,
 242                 unsigned int dataoff,
 243                 u_int16_t l3num,
 244                 u_int8_t protonum,
 245                 struct net *net,
 246                 struct nf_conntrack_tuple *tuple)
 247 {
 248         unsigned int size;
 249         const __be32 *ap;
 250         __be32 _addrs[8];
 251
 252         memset(tuple, 0, sizeof(*tuple));
 253
 254         tuple->src.l3num = l3num;
 255         switch (l3num) {
 256         case NFPROTO_IPV4:
 257                 nhoff += offsetof(struct iphdr, saddr);
 258                 size = 2 * sizeof(__be32);
 259                 break;
 260         case NFPROTO_IPV6:
 261                 nhoff += offsetof(struct ipv6hdr, saddr);
 262                 size = sizeof(_addrs);
 263                 break;
 264         default:
 265                 return true;
 266         }
 267
 268         ap = skb_header_pointer(skb, nhoff, size, _addrs);
 269         if (!ap)
 270                 return false;
 271
 272         switch (l3num) {
 273         case NFPROTO_IPV4:
 274                 tuple->src.u3.ip = ap[0];
 275                 tuple->dst.u3.ip = ap[1];
 276                 break;
 277         case NFPROTO_IPV6:
 278                 memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
 279                 memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
 280                 break;
 281         }
 282
 283         tuple->dst.protonum = protonum;
 284         tuple->dst.dir = IP_CT_DIR_ORIGINAL;
 285
 286         switch (protonum) {
 287 #if IS_ENABLED(CONFIG_IPV6)
 288         case IPPROTO_ICMPV6:
 289                 return icmpv6_pkt_to_tuple(skb, dataoff, net, tuple);
 290 #endif
 291         case IPPROTO_ICMP:
 292                 return icmp_pkt_to_tuple(skb, dataoff, net, tuple);
 293 #ifdef CONFIG_NF_CT_PROTO_GRE
 294         case IPPROTO_GRE:
 295                 return gre_pkt_to_tuple(skb, dataoff, net, tuple);
 296 #endif
 297         case IPPROTO_TCP:
 298         case IPPROTO_UDP: /* fallthrough */
 299                 return nf_ct_get_tuple_ports(skb, dataoff, tuple);
 300 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
 301         case IPPROTO_UDPLITE:
 302                 return nf_ct_get_tuple_ports(skb, dataoff, tuple);
 303 #endif
 304 #ifdef CONFIG_NF_CT_PROTO_SCTP
 305         case IPPROTO_SCTP:
 306                 return nf_ct_get_tuple_ports(skb, dataoff, tuple);
 307 #endif
 308 #ifdef CONFIG_NF_CT_PROTO_DCCP
 309         case IPPROTO_DCCP:
 310                 return nf_ct_get_tuple_ports(skb, dataoff, tuple);
 311 #endif
 312         default:
 313                 break;
 314         }
 315
 316         return true;
 317 }
 318
 319 static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
 320                             u_int8_t *protonum)
 321 {
 322         int dataoff = -1;
 323         const struct iphdr *iph;
 324         struct iphdr _iph;
 325
 326         iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
 327         if (!iph)
 328                 return -1;
 329
 330         /* Conntrack defragments packets, we might still see fragments
 331          * inside ICMP packets though.
 332          */
 333         if (iph->frag_off & htons(IP_OFFSET))
 334                 return -1;
 335
 336         dataoff = nhoff + (iph->ihl << 2);
 337         *protonum = iph->protocol;
 338
 339         /* Check bogus IP headers */
 340         if (dataoff > skb->len) {
 341                 pr_debug("bogus IPv4 packet: nhoff %u, ihl %u, skblen %u\n",
 342                          nhoff, iph->ihl << 2, skb->len);
 343                 return -1;
 344         }
 345         return dataoff;
 346 }
 347
 348 #if IS_ENABLED(CONFIG_IPV6)
 349 static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
 350                             u8 *protonum)
 351 {
 352         int protoff = -1;
 353         unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
 354         __be16 frag_off;
 355         u8 nexthdr;
 356
 357         if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
 358                           &nexthdr, sizeof(nexthdr)) != 0) {
 359                 pr_debug("can't get nexthdr\n");
 360                 return -1;
 361         }
 362         protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off);
 363         /*
 364          * (protoff == skb->len) means the packet has not data, just
 365          * IPv6 and possibly extensions headers, but it is tracked anyway
 366          */
 367         if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
 368                 pr_debug("can't find proto in pkt\n");
 369                 return -1;
 370         }
 371
 372         *protonum = nexthdr;
 373         return protoff;
 374 }
 375 #endif
 376
 377 static int get_l4proto(const struct sk_buff *skb,
 378                        unsigned int nhoff, u8 pf, u8 *l4num)
 379 {
 380         switch (pf) {
 381         case NFPROTO_IPV4:
 382                 return ipv4_get_l4proto(skb, nhoff, l4num);
 383 #if IS_ENABLED(CONFIG_IPV6)
 384         case NFPROTO_IPV6:
 385                 return ipv6_get_l4proto(skb, nhoff, l4num);
 386 #endif
 387         default:
 388                 *l4num = 0;
 389                 break;
 390         }
 391         return -1;
 392 }
 393
 394 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
 395                        u_int16_t l3num,
 396                        struct net *net, struct nf_conntrack_tuple *tuple)
 397 {
 398         u8 protonum;
 399         int protoff;
 400
 401         protoff = get_l4proto(skb, nhoff, l3num, &protonum);
 402         if (protoff <= 0)
 403                 return false;
 404
 405         return nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple);
 406 }
 407 EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
 408
 409 bool
 410 nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 411                    const struct nf_conntrack_tuple *orig)
 412 {
 413         memset(inverse, 0, sizeof(*inverse));
 414
 415         inverse->src.l3num = orig->src.l3num;
 416
 417         switch (orig->src.l3num) {
 418         case NFPROTO_IPV4:
 419                 inverse->src.u3.ip = orig->dst.u3.ip;
 420                 inverse->dst.u3.ip = orig->src.u3.ip;
 421                 break;
 422         case NFPROTO_IPV6:
 423                 inverse->src.u3.in6 = orig->dst.u3.in6;
 424                 inverse->dst.u3.in6 = orig->src.u3.in6;
 425                 break;
 426         default:
 427                 break;
 428         }
 429
 430         inverse->dst.dir = !orig->dst.dir;
 431
 432         inverse->dst.protonum = orig->dst.protonum;
 433
 434         switch (orig->dst.protonum) {
 435         case IPPROTO_ICMP:
 436                 return nf_conntrack_invert_icmp_tuple(inverse, orig);
 437 #if IS_ENABLED(CONFIG_IPV6)
 438         case IPPROTO_ICMPV6:
 439                 return nf_conntrack_invert_icmpv6_tuple(inverse, orig);
 440 #endif
 441         }
 442
 443         inverse->src.u.all = orig->dst.u.all;
 444         inverse->dst.u.all = orig->src.u.all;
 445         return true;
 446 }
 447 EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
 448
 449 /* Generate a almost-unique pseudo-id for a given conntrack.
 450  *
 451  * intentionally doesn't re-use any of the seeds used for hash
 452  * table location, we assume id gets exposed to userspace.
 453  *
 454  * Following nf_conn items do not change throughout lifetime
 455  * of the nf_conn:
 456  *
 457  * 1. nf_conn address
 458  * 2. nf_conn->master address (normally NULL)
 459  * 3. the associated net namespace
 460  * 4. the original direction tuple
 461  */
 462 u32 nf_ct_get_id(const struct nf_conn *ct)
 463 {
 464         static __read_mostly siphash_key_t ct_id_seed;
 465         unsigned long a, b, c, d;
 466
 467         net_get_random_once(&ct_id_seed, sizeof(ct_id_seed));
 468
 469         a = (unsigned long)ct;
 470         b = (unsigned long)ct->master;
 471         c = (unsigned long)nf_ct_net(ct);
 472         d = (unsigned long)siphash(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 473                                    sizeof(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple),
 474                                    &ct_id_seed);
 475 #ifdef CONFIG_64BIT
 476         return siphash_4u64((u64)a, (u64)b, (u64)c, (u64)d, &ct_id_seed);
 477 #else
 478         return siphash_4u32((u32)a, (u32)b, (u32)c, (u32)d, &ct_id_seed);
 479 #endif
 480 }
 481 EXPORT_SYMBOL_GPL(nf_ct_get_id);
 482
 483 static void
 484 clean_from_lists(struct nf_conn *ct)
 485 {
 486         pr_debug("clean_from_lists(%p)\n", ct);
 487         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 488         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
 489
 490         /* Destroy all pending expectations */
 491         nf_ct_remove_expectations(ct);
 492 }
 493
 494 /* must be called with local_bh_disable */
 495 static void nf_ct_add_to_dying_list(struct nf_conn *ct)
 496 {
 497         struct ct_pcpu *pcpu;
 498
 499         /* add this conntrack to the (per cpu) dying list */
 500         ct->cpu = smp_processor_id();
 501         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 502
 503         spin_lock(&pcpu->lock);
 504         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 505                              &pcpu->dying);
 506         spin_unlock(&pcpu->lock);
 507 }
 508
 509 /* must be called with local_bh_disable */
 510 static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
 511 {
 512         struct ct_pcpu *pcpu;
 513
 514         /* add this conntrack to the (per cpu) unconfirmed list */
 515         ct->cpu = smp_processor_id();
 516         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 517
 518         spin_lock(&pcpu->lock);
 519         hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 520                              &pcpu->unconfirmed);
 521         spin_unlock(&pcpu->lock);
 522 }
 523
 524 /* must be called with local_bh_disable */
 525 static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
 526 {
 527         struct ct_pcpu *pcpu;
 528
 529         /* We overload first tuple to link into unconfirmed or dying list.*/
 530         pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
 531
 532         spin_lock(&pcpu->lock);
 533         BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
 534         hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
 535         spin_unlock(&pcpu->lock);
 536 }
 537
 538 #define NFCT_ALIGN(len) (((len) + NFCT_INFOMASK) & ~NFCT_INFOMASK)
 539
 540 /* Released via destroy_conntrack() */
 541 struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
 542                                  const struct nf_conntrack_zone *zone,
 543                                  gfp_t flags)
 544 {
 545         struct nf_conn *tmpl, *p;
 546
 547         if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK) {
 548                 tmpl = kzalloc(sizeof(*tmpl) + NFCT_INFOMASK, flags);
 549                 if (!tmpl)
 550                         return NULL;
 551
 552                 p = tmpl;
 553                 tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
 554                 if (tmpl != p) {
 555                         tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
 556                         tmpl->proto.tmpl_padto = (char *)tmpl - (char *)p;
 557                 }
 558         } else {
 559                 tmpl = kzalloc(sizeof(*tmpl), flags);
 560                 if (!tmpl)
 561                         return NULL;
 562         }
 563
 564         tmpl->status = IPS_TEMPLATE;
 565         write_pnet(&tmpl->ct_net, net);
 566         nf_ct_zone_add(tmpl, zone);
 567         atomic_set(&tmpl->ct_general.use, 0);
 568
 569         return tmpl;
 570 }
 571 EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
 572
 573 void nf_ct_tmpl_free(struct nf_conn *tmpl)
 574 {
 575         nf_ct_ext_destroy(tmpl);
 576
 577         if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK)
 578                 kfree((char *)tmpl - tmpl->proto.tmpl_padto);
 579         else
 580                 kfree(tmpl);
 581 }
 582 EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
 583
 584 static void destroy_gre_conntrack(struct nf_conn *ct)
 585 {
 586 #ifdef CONFIG_NF_CT_PROTO_GRE
 587         struct nf_conn *master = ct->master;
 588
 589         if (master)
 590                 nf_ct_gre_keymap_destroy(master);
 591 #endif
 592 }
 593
 594 static void
 595 destroy_conntrack(struct nf_conntrack *nfct)
 596 {
 597         struct nf_conn *ct = (struct nf_conn *)nfct;
 598
 599         pr_debug("destroy_conntrack(%p)\n", ct);
 600         WARN_ON(atomic_read(&nfct->use) != 0);
 601
 602         if (unlikely(nf_ct_is_template(ct))) {
 603                 nf_ct_tmpl_free(ct);
 604                 return;
 605         }
 606
 607         if (unlikely(nf_ct_protonum(ct) == IPPROTO_GRE))
 608                 destroy_gre_conntrack(ct);
 609
 610         local_bh_disable();
 611         /* Expectations will have been removed in clean_from_lists,
 612          * except TFTP can create an expectation on the first packet,
 613          * before connection is in the list, so we need to clean here,
 614          * too.
 615          */
 616         nf_ct_remove_expectations(ct);
 617
 618         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 619
 620         local_bh_enable();
 621
 622         if (ct->master)
 623                 nf_ct_put(ct->master);
 624
 625         pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
 626         nf_conntrack_free(ct);
 627 }
 628
 629 static void nf_ct_delete_from_lists(struct nf_conn *ct)
 630 {
 631         struct net *net = nf_ct_net(ct);
 632         unsigned int hash, reply_hash;
 633         unsigned int sequence;
 634
 635         nf_ct_helper_destroy(ct);
 636
 637         local_bh_disable();
 638         do {
 639                 sequence = read_seqcount_begin(&nf_conntrack_generation);
 640                 hash = hash_conntrack(net,
 641                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 642                 reply_hash = hash_conntrack(net,
 643                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 644         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 645
 646         clean_from_lists(ct);
 647         nf_conntrack_double_unlock(hash, reply_hash);
 648
 649         nf_ct_add_to_dying_list(ct);
 650
 651         local_bh_enable();
 652 }
 653
 654 bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
 655 {
 656         struct nf_conn_tstamp *tstamp;
 657
 658         if (test_and_set_bit(IPS_DYING_BIT, &ct->status))
 659                 return false;
 660
 661         tstamp = nf_conn_tstamp_find(ct);
 662         if (tstamp && tstamp->stop == 0)
 663                 tstamp->stop = ktime_get_real_ns();
 664
 665         if (nf_conntrack_event_report(IPCT_DESTROY, ct,
 666                                     portid, report) < 0) {
 667                 /* destroy event was not delivered. nf_ct_put will
 668                  * be done by event cache worker on redelivery.
 669                  */
 670                 nf_ct_delete_from_lists(ct);
 671                 nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
 672                 return false;
 673         }
 674
 675         nf_conntrack_ecache_work(nf_ct_net(ct));
 676         nf_ct_delete_from_lists(ct);
 677         nf_ct_put(ct);
 678         return true;
 679 }
 680 EXPORT_SYMBOL_GPL(nf_ct_delete);
 681
 682 static inline bool
 683 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 684                 const struct nf_conntrack_tuple *tuple,
 685                 const struct nf_conntrack_zone *zone,
 686                 const struct net *net)
 687 {
 688         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 689
 690         /* A conntrack can be recreated with the equal tuple,
 691          * so we need to check that the conntrack is confirmed
 692          */
 693         return nf_ct_tuple_equal(tuple, &h->tuple) &&
 694                nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
 695                nf_ct_is_confirmed(ct) &&
 696                net_eq(net, nf_ct_net(ct));
 697 }
 698
 699 static inline bool
 700 nf_ct_match(const struct nf_conn *ct1, const struct nf_conn *ct2)
 701 {
 702         return nf_ct_tuple_equal(&ct1->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 703                                  &ct2->tuplehash[IP_CT_DIR_ORIGINAL].tuple) &&
 704                nf_ct_tuple_equal(&ct1->tuplehash[IP_CT_DIR_REPLY].tuple,
 705                                  &ct2->tuplehash[IP_CT_DIR_REPLY].tuple) &&
 706                nf_ct_zone_equal(ct1, nf_ct_zone(ct2), IP_CT_DIR_ORIGINAL) &&
 707                nf_ct_zone_equal(ct1, nf_ct_zone(ct2), IP_CT_DIR_REPLY) &&
 708                net_eq(nf_ct_net(ct1), nf_ct_net(ct2));
 709 }
 710
 711 /* caller must hold rcu readlock and none of the nf_conntrack_locks */
 712 static void nf_ct_gc_expired(struct nf_conn *ct)
 713 {
 714         if (!atomic_inc_not_zero(&ct->ct_general.use))
 715                 return;
 716
 717         if (nf_ct_should_gc(ct))
 718                 nf_ct_kill(ct);
 719
 720         nf_ct_put(ct);
 721 }
 722
 723 /*
 724  * Warning :
 725  * - Caller must take a reference on returned object
 726  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
 727  */
 728 static struct nf_conntrack_tuple_hash *
 729 ____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
 730                       const struct nf_conntrack_tuple *tuple, u32 hash)
 731 {
 732         struct nf_conntrack_tuple_hash *h;
 733         struct hlist_nulls_head *ct_hash;
 734         struct hlist_nulls_node *n;
 735         unsigned int bucket, hsize;
 736
 737 begin:
 738         nf_conntrack_get_ht(&ct_hash, &hsize);
 739         bucket = reciprocal_scale(hash, hsize);
 740
 741         hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
 742                 struct nf_conn *ct;
 743
 744                 ct = nf_ct_tuplehash_to_ctrack(h);
 745                 if (nf_ct_is_expired(ct)) {
 746                         nf_ct_gc_expired(ct);
 747                         continue;
 748                 }
 749
 750                 if (nf_ct_key_equal(h, tuple, zone, net))
 751                         return h;
 752         }
 753         /*
 754          * if the nulls value we got at the end of this lookup is
 755          * not the expected one, we must restart lookup.
 756          * We probably met an item that was moved to another chain.
 757          */
 758         if (get_nulls_value(n) != bucket) {
 759                 NF_CT_STAT_INC_ATOMIC(net, search_restart);
 760                 goto begin;
 761         }
 762
 763         return NULL;
 764 }
 765
 766 /* Find a connection corresponding to a tuple. */
 767 static struct nf_conntrack_tuple_hash *
 768 __nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 769                         const struct nf_conntrack_tuple *tuple, u32 hash)
 770 {
 771         struct nf_conntrack_tuple_hash *h;
 772         struct nf_conn *ct;
 773
 774         rcu_read_lock();
 775
 776         h = ____nf_conntrack_find(net, zone, tuple, hash);
 777         if (h) {
 778                 /* We have a candidate that matches the tuple we're interested
 779                  * in, try to obtain a reference and re-check tuple
 780                  */
 781                 ct = nf_ct_tuplehash_to_ctrack(h);
 782                 if (likely(atomic_inc_not_zero(&ct->ct_general.use))) {
 783                         if (likely(nf_ct_key_equal(h, tuple, zone, net)))
 784                                 goto found;
 785
 786                         /* TYPESAFE_BY_RCU recycled the candidate */
 787                         nf_ct_put(ct);
 788                 }
 789
 790                 h = NULL;
 791         }
 792 found:
 793         rcu_read_unlock();
 794
 795         return h;
 796 }
 797
 798 struct nf_conntrack_tuple_hash *
 799 nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 800                       const struct nf_conntrack_tuple *tuple)
 801 {
 802         return __nf_conntrack_find_get(net, zone, tuple,
 803                                        hash_conntrack_raw(tuple, net));
 804 }
 805 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 806
 807 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 808                                        unsigned int hash,
 809                                        unsigned int reply_hash)
 810 {
 811         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
 812                            &nf_conntrack_hash[hash]);
 813         hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
 814                            &nf_conntrack_hash[reply_hash]);
 815 }
 816
 817 int
 818 nf_conntrack_hash_check_insert(struct nf_conn *ct)
 819 {
 820         const struct nf_conntrack_zone *zone;
 821         struct net *net = nf_ct_net(ct);
 822         unsigned int hash, reply_hash;
 823         struct nf_conntrack_tuple_hash *h;
 824         struct hlist_nulls_node *n;
 825         unsigned int sequence;
 826
 827         zone = nf_ct_zone(ct);
 828
 829         local_bh_disable();
 830         do {
 831                 sequence = read_seqcount_begin(&nf_conntrack_generation);
 832                 hash = hash_conntrack(net,
 833                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 834                 reply_hash = hash_conntrack(net,
 835                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 836         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 837
 838         /* See if there's one in the list already, including reverse */
 839         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
 840                 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 841                                     zone, net))
 842                         goto out;
 843
 844         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
 845                 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 846                                     zone, net))
 847                         goto out;
 848
 849         smp_wmb();
 850         /* The caller holds a reference to this object */
 851         atomic_set(&ct->ct_general.use, 2);
 852         __nf_conntrack_hash_insert(ct, hash, reply_hash);
 853         nf_conntrack_double_unlock(hash, reply_hash);
 854         NF_CT_STAT_INC(net, insert);
 855         local_bh_enable();
 856         return 0;
 857
 858 out:
 859         nf_conntrack_double_unlock(hash, reply_hash);
 860         NF_CT_STAT_INC(net, insert_failed);
 861         local_bh_enable();
 862         return -EEXIST;
 863 }
 864 EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
 865
 866 static inline void nf_ct_acct_update(struct nf_conn *ct,
 867                                      enum ip_conntrack_info ctinfo,
 868                                      unsigned int len)
 869 {
 870         struct nf_conn_acct *acct;
 871
 872         acct = nf_conn_acct_find(ct);
 873         if (acct) {
 874                 struct nf_conn_counter *counter = acct->counter;
 875
 876                 atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
 877                 atomic64_add(len, &counter[CTINFO2DIR(ctinfo)].bytes);
 878         }
 879 }
 880
 881 static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 882                              const struct nf_conn *loser_ct)
 883 {
 884         struct nf_conn_acct *acct;
 885
 886         acct = nf_conn_acct_find(loser_ct);
 887         if (acct) {
 888                 struct nf_conn_counter *counter = acct->counter;
 889                 unsigned int bytes;
 890
 891                 /* u32 should be fine since we must have seen one packet. */
 892                 bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
 893                 nf_ct_acct_update(ct, ctinfo, bytes);
 894         }
 895 }
 896
 897 /* Resolve race on insertion if this protocol allows this. */
 898 static int nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
 899                                enum ip_conntrack_info ctinfo,
 900                                struct nf_conntrack_tuple_hash *h)
 901 {
 902         /* This is the conntrack entry already in hashes that won race. */
 903         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 904         const struct nf_conntrack_l4proto *l4proto;
 905         enum ip_conntrack_info oldinfo;
 906         struct nf_conn *loser_ct = nf_ct_get(skb, &oldinfo);
 907
 908         l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
 909         if (l4proto->allow_clash &&
 910             !nf_ct_is_dying(ct) &&
 911             atomic_inc_not_zero(&ct->ct_general.use)) {
 912                 if (((ct->status & IPS_NAT_DONE_MASK) == 0) ||
 913                     nf_ct_match(ct, loser_ct)) {
 914                         nf_ct_acct_merge(ct, ctinfo, loser_ct);
 915                         nf_conntrack_put(&loser_ct->ct_general);
 916                         nf_ct_set(skb, ct, oldinfo);
 917                         return NF_ACCEPT;
 918                 }
 919                 nf_ct_put(ct);
 920         }
 921         NF_CT_STAT_INC(net, drop);
 922         return NF_DROP;
 923 }
 924
 925 /* Confirm a connection given skb; places it in hash table */
 926 int
 927 __nf_conntrack_confirm(struct sk_buff *skb)
 928 {
 929         const struct nf_conntrack_zone *zone;
 930         unsigned int hash, reply_hash;
 931         struct nf_conntrack_tuple_hash *h;
 932         struct nf_conn *ct;
 933         struct nf_conn_help *help;
 934         struct nf_conn_tstamp *tstamp;
 935         struct hlist_nulls_node *n;
 936         enum ip_conntrack_info ctinfo;
 937         struct net *net;
 938         unsigned int sequence;
 939         int ret = NF_DROP;
 940
 941         ct = nf_ct_get(skb, &ctinfo);
 942         net = nf_ct_net(ct);
 943
 944         /* ipt_REJECT uses nf_conntrack_attach to attach related
 945            ICMP/TCP RST packets in other direction.  Actual packet
 946            which created connection will be IP_CT_NEW or for an
 947            expected connection, IP_CT_RELATED. */
 948         if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
 949                 return NF_ACCEPT;
 950
 951         zone = nf_ct_zone(ct);
 952         local_bh_disable();
 953
 954         do {
 955                 sequence = read_seqcount_begin(&nf_conntrack_generation);
 956                 /* reuse the hash saved before */
 957                 hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
 958                 hash = scale_hash(hash);
 959                 reply_hash = hash_conntrack(net,
 960                                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 961
 962         } while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 963
 964         /* We're not in hash table, and we refuse to set up related
 965          * connections for unconfirmed conns.  But packet copies and
 966          * REJECT will give spurious warnings here.
 967          */
 968
 969         /* Another skb with the same unconfirmed conntrack may
 970          * win the race. This may happen for bridge(br_flood)
 971          * or broadcast/multicast packets do skb_clone with
 972          * unconfirmed conntrack.
 973          */
 974         if (unlikely(nf_ct_is_confirmed(ct))) {
 975                 WARN_ON_ONCE(1);
 976                 nf_conntrack_double_unlock(hash, reply_hash);
 977                 local_bh_enable();
 978                 return NF_DROP;
 979         }
 980
 981         pr_debug("Confirming conntrack %p\n", ct);
 982         /* We have to check the DYING flag after unlink to prevent
 983          * a race against nf_ct_get_next_corpse() possibly called from
 984          * user context, else we insert an already 'dead' hash, blocking
 985          * further use of that particular connection -JM.
 986          */
 987         nf_ct_del_from_dying_or_unconfirmed_list(ct);
 988
 989         if (unlikely(nf_ct_is_dying(ct))) {
 990                 nf_ct_add_to_dying_list(ct);
 991                 goto dying;
 992         }
 993
 994         /* See if there's one in the list already, including reverse:
 995            NAT could have grabbed it without realizing, since we're
 996            not in the hash.  If there is, we lost race. */
 997         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
 998                 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 999                                     zone, net))
1000                         goto out;
1001
1002         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
1003                 if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
1004                                     zone, net))
1005                         goto out;
1006
1007         /* Timer relative to confirmation time, not original
1008            setting time, otherwise we'd get timer wrap in
1009            weird delay cases. */
1010         ct->timeout += nfct_time_stamp;
1011         atomic_inc(&ct->ct_general.use);
1012         ct->status |= IPS_CONFIRMED;
1013
1014         /* set conntrack timestamp, if enabled. */
1015         tstamp = nf_conn_tstamp_find(ct);
1016         if (tstamp)
1017                 tstamp->start = ktime_get_real_ns();
1018
1019         /* Since the lookup is lockless, hash insertion must be done after
1020          * starting the timer and setting the CONFIRMED bit. The RCU barriers
1021          * guarantee that no other CPU can find the conntrack before the above
1022          * stores are visible.
1023          */
1024         __nf_conntrack_hash_insert(ct, hash, reply_hash);
1025         nf_conntrack_double_unlock(hash, reply_hash);
1026         local_bh_enable();
1027
1028         help = nfct_help(ct);
1029         if (help && help->helper)
1030                 nf_conntrack_event_cache(IPCT_HELPER, ct);
1031
1032         nf_conntrack_event_cache(master_ct(ct) ?
1033                                  IPCT_RELATED : IPCT_NEW, ct);
1034         return NF_ACCEPT;
1035
1036 out:
1037         nf_ct_add_to_dying_list(ct);
1038         ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
1039 dying:
1040         nf_conntrack_double_unlock(hash, reply_hash);
1041         NF_CT_STAT_INC(net, insert_failed);
1042         local_bh_enable();
1043         return ret;
1044 }
1045 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
1046
1047 /* Returns true if a connection correspondings to the tuple (required
1048    for NAT). */
1049 int
1050 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
1051                          const struct nf_conn *ignored_conntrack)
1052 {
1053         struct net *net = nf_ct_net(ignored_conntrack);
1054         const struct nf_conntrack_zone *zone;
1055         struct nf_conntrack_tuple_hash *h;
1056         struct hlist_nulls_head *ct_hash;
1057         unsigned int hash, hsize;
1058         struct hlist_nulls_node *n;
1059         struct nf_conn *ct;
1060
1061         zone = nf_ct_zone(ignored_conntrack);
1062
1063         rcu_read_lock();
1064  begin:
1065         nf_conntrack_get_ht(&ct_hash, &hsize);
1066         hash = __hash_conntrack(net, tuple, hsize);
1067
1068         hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
1069                 ct = nf_ct_tuplehash_to_ctrack(h);
1070
1071                 if (ct == ignored_conntrack)
1072                         continue;
1073
1074                 if (nf_ct_is_expired(ct)) {
1075                         nf_ct_gc_expired(ct);
1076                         continue;
1077                 }
1078
1079                 if (nf_ct_key_equal(h, tuple, zone, net)) {
1080                         /* Tuple is taken already, so caller will need to find
1081                          * a new source port to use.
1082                          *
1083                          * Only exception:
1084                          * If the *original tuples* are identical, then both
1085                          * conntracks refer to the same flow.
1086                          * This is a rare situation, it can occur e.g. when
1087                          * more than one UDP packet is sent from same socket
1088                          * in different threads.
1089                          *
1090                          * Let nf_ct_resolve_clash() deal with this later.
1091                          */
1092                         if (nf_ct_tuple_equal(&ignored_conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
1093                                               &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple))
1094                                 continue;
1095
1096                         NF_CT_STAT_INC_ATOMIC(net, found);
1097                         rcu_read_unlock();
1098                         return 1;
1099                 }
1100         }
1101
1102         if (get_nulls_value(n) != hash) {
1103                 NF_CT_STAT_INC_ATOMIC(net, search_restart);
1104                 goto begin;
1105         }
1106
1107         rcu_read_unlock();
1108
1109         return 0;
1110 }
1111 EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
1112
1113 #define NF_CT_EVICTION_RANGE    8
1114
1115 /* There's a small race here where we may free a just-assured
1116    connection.  Too bad: we're in trouble anyway. */
1117 static unsigned int early_drop_list(struct net *net,
1118                                     struct hlist_nulls_head *head)
1119 {
1120         struct nf_conntrack_tuple_hash *h;
1121         struct hlist_nulls_node *n;
1122         unsigned int drops = 0;
1123         struct nf_conn *tmp;
1124
1125         hlist_nulls_for_each_entry_rcu(h, n, head, hnnode) {
1126                 tmp = nf_ct_tuplehash_to_ctrack(h);
1127
1128                 if (test_bit(IPS_OFFLOAD_BIT, &tmp->status))
1129                         continue;
1130
1131                 if (nf_ct_is_expired(tmp)) {
1132                         nf_ct_gc_expired(tmp);
1133                         continue;
1134                 }
1135
1136                 if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
1137                     !net_eq(nf_ct_net(tmp), net) ||
1138                     nf_ct_is_dying(tmp))
1139                         continue;
1140
1141                 if (!atomic_inc_not_zero(&tmp->ct_general.use))
1142                         continue;
1143
1144                 /* kill only if still in same netns -- might have moved due to
1145                  * SLAB_TYPESAFE_BY_RCU rules.
1146                  *
1147                  * We steal the timer reference.  If that fails timer has
1148                  * already fired or someone else deleted it. Just drop ref
1149                  * and move to next entry.
1150                  */
1151                 if (net_eq(nf_ct_net(tmp), net) &&
1152                     nf_ct_is_confirmed(tmp) &&
1153                     nf_ct_delete(tmp, 0, 0))
1154                         drops++;
1155
1156                 nf_ct_put(tmp);
1157         }
1158
1159         return drops;
1160 }
1161
1162 static noinline int early_drop(struct net *net, unsigned int hash)
1163 {
1164         unsigned int i, bucket;
1165
1166         for (i = 0; i < NF_CT_EVICTION_RANGE; i++) {
1167                 struct hlist_nulls_head *ct_hash;
1168                 unsigned int hsize, drops;
1169
1170                 rcu_read_lock();
1171                 nf_conntrack_get_ht(&ct_hash, &hsize);
1172                 if (!i)
1173                         bucket = reciprocal_scale(hash, hsize);
1174                 else
1175                         bucket = (bucket + 1) % hsize;
1176
1177                 drops = early_drop_list(net, &ct_hash[bucket]);
1178                 rcu_read_unlock();
1179
1180                 if (drops) {
1181                         NF_CT_STAT_ADD_ATOMIC(net, early_drop, drops);
1182                         return true;
1183                 }
1184         }
1185
1186         return false;
1187 }
1188
1189 static bool gc_worker_skip_ct(const struct nf_conn *ct)
1190 {
1191         return !nf_ct_is_confirmed(ct) || nf_ct_is_dying(ct);
1192 }
1193
1194 static bool gc_worker_can_early_drop(const struct nf_conn *ct)
1195 {
1196         const struct nf_conntrack_l4proto *l4proto;
1197
1198         if (!test_bit(IPS_ASSURED_BIT, &ct->status))
1199                 return true;
1200
1201         l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
1202         if (l4proto->can_early_drop && l4proto->can_early_drop(ct))
1203                 return true;
1204
1205         return false;
1206 }
1207
1208 #define DAY     (86400 * HZ)
1209
1210 /* Set an arbitrary timeout large enough not to ever expire, this save
1211  * us a check for the IPS_OFFLOAD_BIT from the packet path via
1212  * nf_ct_is_expired().
1213  */
1214 static void nf_ct_offload_timeout(struct nf_conn *ct)
1215 {
1216         if (nf_ct_expires(ct) < DAY / 2)
1217                 ct->timeout = nfct_time_stamp + DAY;
1218 }
1219
1220 static void gc_worker(struct work_struct *work)
1221 {
1222         unsigned int min_interval = max(HZ / GC_MAX_BUCKETS_DIV, 1u);
1223         unsigned int i, goal, buckets = 0, expired_count = 0;
1224         unsigned int nf_conntrack_max95 = 0;
1225         struct conntrack_gc_work *gc_work;
1226         unsigned int ratio, scanned = 0;
1227         unsigned long next_run;
1228
1229         gc_work = container_of(work, struct conntrack_gc_work, dwork.work);
1230
1231         goal = nf_conntrack_htable_size / GC_MAX_BUCKETS_DIV;
1232         i = gc_work->last_bucket;
1233         if (gc_work->early_drop)
1234                 nf_conntrack_max95 = nf_conntrack_max / 100u * 95u;
1235
1236         do {
1237                 struct nf_conntrack_tuple_hash *h;
1238                 struct hlist_nulls_head *ct_hash;
1239                 struct hlist_nulls_node *n;
1240                 unsigned int hashsz;
1241                 struct nf_conn *tmp;
1242
1243                 i++;
1244                 rcu_read_lock();
1245
1246                 nf_conntrack_get_ht(&ct_hash, &hashsz);
1247                 if (i >= hashsz)
1248                         i = 0;
1249
1250                 hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[i], hnnode) {
1251                         struct net *net;
1252
1253                         tmp = nf_ct_tuplehash_to_ctrack(h);
1254
1255                         scanned++;
1256                         if (test_bit(IPS_OFFLOAD_BIT, &tmp->status)) {
1257                                 nf_ct_offload_timeout(tmp);
1258                                 continue;
1259                         }
1260
1261                         if (nf_ct_is_expired(tmp)) {
1262                                 nf_ct_gc_expired(tmp);
1263                                 expired_count++;
1264                                 continue;
1265                         }
1266
1267                         if (nf_conntrack_max95 == 0 || gc_worker_skip_ct(tmp))
1268                                 continue;
1269
1270                         net = nf_ct_net(tmp);
1271                         if (atomic_read(&net->ct.count) < nf_conntrack_max95)
1272                                 continue;
1273
1274                         /* need to take reference to avoid possible races */
1275                         if (!atomic_inc_not_zero(&tmp->ct_general.use))
1276                                 continue;
1277
1278                         if (gc_worker_skip_ct(tmp)) {
1279                                 nf_ct_put(tmp);
1280                                 continue;
1281                         }
1282
1283                         if (gc_worker_can_early_drop(tmp))
1284                                 nf_ct_kill(tmp);
1285
1286                         nf_ct_put(tmp);
1287                 }
1288
1289                 /* could check get_nulls_value() here and restart if ct
1290                  * was moved to another chain.  But given gc is best-effort
1291                  * we will just continue with next hash slot.
1292                  */
1293                 rcu_read_unlock();
1294                 cond_resched();
1295         } while (++buckets < goal);
1296
1297         if (gc_work->exiting)
1298                 return;
1299
1300         /*
1301          * Eviction will normally happen from the packet path, and not
1302          * from this gc worker.
1303          *
1304          * This worker is only here to reap expired entries when system went
1305          * idle after a busy period.
1306          *
1307          * The heuristics below are supposed to balance conflicting goals:
1308          *
1309          * 1. Minimize time until we notice a stale entry
1310          * 2. Maximize scan intervals to not waste cycles
1311          *
1312          * Normally, expire ratio will be close to 0.
1313          *
1314          * As soon as a sizeable fraction of the entries have expired
1315          * increase scan frequency.
1316          */
1317         ratio = scanned ? expired_count * 100 / scanned : 0;
1318         if (ratio > GC_EVICT_RATIO) {
1319                 gc_work->next_gc_run = min_interval;
1320         } else {
1321                 unsigned int max = GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV;
1322
1323                 BUILD_BUG_ON((GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV) == 0);
1324
1325                 gc_work->next_gc_run += min_interval;
1326                 if (gc_work->next_gc_run > max)
1327                         gc_work->next_gc_run = max;
1328         }
1329
1330         next_run = gc_work->next_gc_run;
1331         gc_work->last_bucket = i;
1332         gc_work->early_drop = false;
1333         queue_delayed_work(system_power_efficient_wq, &gc_work->dwork, next_run);
1334 }
1335
1336 static void conntrack_gc_work_init(struct conntrack_gc_work *gc_work)
1337 {
1338         INIT_DEFERRABLE_WORK(&gc_work->dwork, gc_worker);
1339         gc_work->next_gc_run = HZ;
1340         gc_work->exiting = false;
1341 }
1342
1343 static struct nf_conn *
1344 __nf_conntrack_alloc(struct net *net,
1345                      const struct nf_conntrack_zone *zone,
1346                      const struct nf_conntrack_tuple *orig,
1347                      const struct nf_conntrack_tuple *repl,
1348                      gfp_t gfp, u32 hash)
1349 {
1350         struct nf_conn *ct;
1351
1352         /* We don't want any race condition at early drop stage */
1353         atomic_inc(&net->ct.count);
1354
1355         if (nf_conntrack_max &&
1356             unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
1357                 if (!early_drop(net, hash)) {
1358                         if (!conntrack_gc_work.early_drop)
1359                                 conntrack_gc_work.early_drop = true;
1360                         atomic_dec(&net->ct.count);
1361                         net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
1362                         return ERR_PTR(-ENOMEM);
1363                 }
1364         }
1365
1366         /*
1367          * Do not use kmem_cache_zalloc(), as this cache uses
1368          * SLAB_TYPESAFE_BY_RCU.
1369          */
1370         ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
1371         if (ct == NULL)
1372                 goto out;
1373
1374         spin_lock_init(&ct->lock);
1375         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
1376         ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
1377         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
1378         /* save hash for reusing when confirming */
1379         *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
1380         ct->status = 0;
1381         ct->timeout = 0;
1382         write_pnet(&ct->ct_net, net);
1383         memset(&ct->__nfct_init_offset[0], 0,
1384                offsetof(struct nf_conn, proto) -
1385                offsetof(struct nf_conn, __nfct_init_offset[0]));
1386
1387         nf_ct_zone_add(ct, zone);
1388
1389         /* Because we use RCU lookups, we set ct_general.use to zero before
1390          * this is inserted in any list.
1391          */
1392         atomic_set(&ct->ct_general.use, 0);
1393         return ct;
1394 out:
1395         atomic_dec(&net->ct.count);
1396         return ERR_PTR(-ENOMEM);
1397 }
1398
1399 struct nf_conn *nf_conntrack_alloc(struct net *net,
1400                                    const struct nf_conntrack_zone *zone,
1401                                    const struct nf_conntrack_tuple *orig,
1402                                    const struct nf_conntrack_tuple *repl,
1403                                    gfp_t gfp)
1404 {
1405         return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
1406 }
1407 EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
1408
1409 void nf_conntrack_free(struct nf_conn *ct)
1410 {
1411         struct net *net = nf_ct_net(ct);
1412
1413         /* A freed object has refcnt == 0, that's
1414          * the golden rule for SLAB_TYPESAFE_BY_RCU
1415          */
1416         WARN_ON(atomic_read(&ct->ct_general.use) != 0);
1417
1418         nf_ct_ext_destroy(ct);
1419         kmem_cache_free(nf_conntrack_cachep, ct);
1420         smp_mb__before_atomic();
1421         atomic_dec(&net->ct.count);
1422 }
1423 EXPORT_SYMBOL_GPL(nf_conntrack_free);
1424
1425
1426 /* Allocate a new conntrack: we return -ENOMEM if classification
1427    failed due to stress.  Otherwise it really is unclassifiable. */
1428 static noinline struct nf_conntrack_tuple_hash *
1429 init_conntrack(struct net *net, struct nf_conn *tmpl,
1430                const struct nf_conntrack_tuple *tuple,
1431                struct sk_buff *skb,
1432                unsigned int dataoff, u32 hash)
1433 {
1434         struct nf_conn *ct;
1435         struct nf_conn_help *help;
1436         struct nf_conntrack_tuple repl_tuple;
1437         struct nf_conntrack_ecache *ecache;
1438         struct nf_conntrack_expect *exp = NULL;
1439         const struct nf_conntrack_zone *zone;
1440         struct nf_conn_timeout *timeout_ext;
1441         struct nf_conntrack_zone tmp;
1442
1443         if (!nf_ct_invert_tuple(&repl_tuple, tuple)) {
1444                 pr_debug("Can't invert tuple.\n");
1445                 return NULL;
1446         }
1447
1448         zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1449         ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
1450                                   hash);
1451         if (IS_ERR(ct))
1452                 return (struct nf_conntrack_tuple_hash *)ct;
1453
1454         if (!nf_ct_add_synproxy(ct, tmpl)) {
1455                 nf_conntrack_free(ct);
1456                 return ERR_PTR(-ENOMEM);
1457         }
1458
1459         timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
1460
1461         if (timeout_ext)
1462                 nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
1463                                       GFP_ATOMIC);
1464
1465         nf_ct_acct_ext_add(ct, GFP_ATOMIC);
1466         nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
1467         nf_ct_labels_ext_add(ct);
1468
1469         ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
1470         nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
1471                                  ecache ? ecache->expmask : 0,
1472                              GFP_ATOMIC);
1473
1474         local_bh_disable();
1475         if (net->ct.expect_count) {
1476                 spin_lock(&nf_conntrack_expect_lock);
1477                 exp = nf_ct_find_expectation(net, zone, tuple);
1478                 if (exp) {
1479                         pr_debug("expectation arrives ct=%p exp=%p\n",
1480                                  ct, exp);
1481                         /* Welcome, Mr. Bond.  We've been expecting you... */
1482                         __set_bit(IPS_EXPECTED_BIT, &ct->status);
1483                         /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
1484                         ct->master = exp->master;
1485                         if (exp->helper) {
1486                                 help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
1487                                 if (help)
1488                                         rcu_assign_pointer(help->helper, exp->helper);
1489                         }
1490
1491 #ifdef CONFIG_NF_CONNTRACK_MARK
1492                         ct->mark = exp->master->mark;
1493 #endif
1494 #ifdef CONFIG_NF_CONNTRACK_SECMARK
1495                         ct->secmark = exp->master->secmark;
1496 #endif
1497                         NF_CT_STAT_INC(net, expect_new);
1498                 }
1499                 spin_unlock(&nf_conntrack_expect_lock);
1500         }
1501         if (!exp)
1502                 __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
1503
1504         /* Now it is inserted into the unconfirmed list, bump refcount */
1505         nf_conntrack_get(&ct->ct_general);
1506         nf_ct_add_to_unconfirmed_list(ct);
1507
1508         local_bh_enable();
1509
1510         if (exp) {
1511                 if (exp->expectfn)
1512                         exp->expectfn(ct, exp);
1513                 nf_ct_expect_put(exp);
1514         }
1515
1516         return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
1517 }
1518
1519 /* On success, returns 0, sets skb->_nfct | ctinfo */
1520 static int
1521 resolve_normal_ct(struct nf_conn *tmpl,
1522                   struct sk_buff *skb,
1523                   unsigned int dataoff,
1524                   u_int8_t protonum,
1525                   const struct nf_hook_state *state)
1526 {
1527         const struct nf_conntrack_zone *zone;
1528         struct nf_conntrack_tuple tuple;
1529         struct nf_conntrack_tuple_hash *h;
1530         enum ip_conntrack_info ctinfo;
1531         struct nf_conntrack_zone tmp;
1532         struct nf_conn *ct;
1533         u32 hash;
1534
1535         if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
1536                              dataoff, state->pf, protonum, state->net,
1537                              &tuple)) {
1538                 pr_debug("Can't get tuple\n");
1539                 return 0;
1540         }
1541
1542         /* look for tuple match */
1543         zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
1544         hash = hash_conntrack_raw(&tuple, state->net);
1545         h = __nf_conntrack_find_get(state->net, zone, &tuple, hash);
1546         if (!h) {
1547                 h = init_conntrack(state->net, tmpl, &tuple,
1548                                    skb, dataoff, hash);
1549                 if (!h)
1550                         return 0;
1551                 if (IS_ERR(h))
1552                         return PTR_ERR(h);
1553         }
1554         ct = nf_ct_tuplehash_to_ctrack(h);
1555
1556         /* It exists; we have (non-exclusive) reference. */
1557         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
1558                 ctinfo = IP_CT_ESTABLISHED_REPLY;
1559         } else {
1560                 /* Once we've had two way comms, always ESTABLISHED. */
1561                 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1562                         pr_debug("normal packet for %p\n", ct);
1563                         ctinfo = IP_CT_ESTABLISHED;
1564                 } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
1565                         pr_debug("related packet for %p\n", ct);
1566                         ctinfo = IP_CT_RELATED;
1567                 } else {
1568                         pr_debug("new packet for %p\n", ct);
1569                         ctinfo = IP_CT_NEW;
1570                 }
1571         }
1572         nf_ct_set(skb, ct, ctinfo);
1573         return 0;
1574 }
1575
1576 /*
1577  * icmp packets need special treatment to handle error messages that are
1578  * related to a connection.
1579  *
1580  * Callers need to check if skb has a conntrack assigned when this
1581  * helper returns; in such case skb belongs to an already known connection.
1582  */
1583 static unsigned int __cold
1584 nf_conntrack_handle_icmp(struct nf_conn *tmpl,
1585                          struct sk_buff *skb,
1586                          unsigned int dataoff,
1587                          u8 protonum,
1588                          const struct nf_hook_state *state)
1589 {
1590         int ret;
1591
1592         if (state->pf == NFPROTO_IPV4 && protonum == IPPROTO_ICMP)
1593                 ret = nf_conntrack_icmpv4_error(tmpl, skb, dataoff, state);
1594 #if IS_ENABLED(CONFIG_IPV6)
1595         else if (state->pf == NFPROTO_IPV6 && protonum == IPPROTO_ICMPV6)
1596                 ret = nf_conntrack_icmpv6_error(tmpl, skb, dataoff, state);
1597 #endif
1598         else
1599                 return NF_ACCEPT;
1600
1601         if (ret <= 0) {
1602                 NF_CT_STAT_INC_ATOMIC(state->net, error);
1603                 NF_CT_STAT_INC_ATOMIC(state->net, invalid);
1604         }
1605
1606         return ret;
1607 }
1608
1609 static int generic_packet(struct nf_conn *ct, struct sk_buff *skb,
1610                           enum ip_conntrack_info ctinfo)
1611 {
1612         const unsigned int *timeout = nf_ct_timeout_lookup(ct);
1613
1614         if (!timeout)
1615                 timeout = &nf_generic_pernet(nf_ct_net(ct))->timeout;
1616
1617         nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
1618         return NF_ACCEPT;
1619 }
1620
1621 /* Returns verdict for packet, or -1 for invalid. */
1622 static int nf_conntrack_handle_packet(struct nf_conn *ct,
1623                                       struct sk_buff *skb,
1624                                       unsigned int dataoff,
1625                                       enum ip_conntrack_info ctinfo,
1626                                       const struct nf_hook_state *state)
1627 {
1628         switch (nf_ct_protonum(ct)) {
1629         case IPPROTO_TCP:
1630                 return nf_conntrack_tcp_packet(ct, skb, dataoff,
1631                                                ctinfo, state);
1632         case IPPROTO_UDP:
1633                 return nf_conntrack_udp_packet(ct, skb, dataoff,
1634                                                ctinfo, state);
1635         case IPPROTO_ICMP:
1636                 return nf_conntrack_icmp_packet(ct, skb, ctinfo, state);
1637 #if IS_ENABLED(CONFIG_IPV6)
1638         case IPPROTO_ICMPV6:
1639                 return nf_conntrack_icmpv6_packet(ct, skb, ctinfo, state);
1640 #endif
1641 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
1642         case IPPROTO_UDPLITE:
1643                 return nf_conntrack_udplite_packet(ct, skb, dataoff,
1644                                                    ctinfo, state);
1645 #endif
1646 #ifdef CONFIG_NF_CT_PROTO_SCTP
1647         case IPPROTO_SCTP:
1648                 return nf_conntrack_sctp_packet(ct, skb, dataoff,
1649                                                 ctinfo, state);
1650 #endif
1651 #ifdef CONFIG_NF_CT_PROTO_DCCP
1652         case IPPROTO_DCCP:
1653                 return nf_conntrack_dccp_packet(ct, skb, dataoff,
1654                                                 ctinfo, state);
1655 #endif
1656 #ifdef CONFIG_NF_CT_PROTO_GRE
1657         case IPPROTO_GRE:
1658                 return nf_conntrack_gre_packet(ct, skb, dataoff,
1659                                                ctinfo, state);
1660 #endif
1661         }
1662
1663         return generic_packet(ct, skb, ctinfo);
1664 }
1665
1666 unsigned int
1667 nf_conntrack_in(struct sk_buff *skb, const struct nf_hook_state *state)
1668 {
1669         enum ip_conntrack_info ctinfo;
1670         struct nf_conn *ct, *tmpl;
1671         u_int8_t protonum;
1672         int dataoff, ret;
1673
1674         tmpl = nf_ct_get(skb, &ctinfo);
1675         if (tmpl || ctinfo == IP_CT_UNTRACKED) {
1676                 /* Previously seen (loopback or untracked)?  Ignore. */
1677                 if ((tmpl && !nf_ct_is_template(tmpl)) ||
1678                      ctinfo == IP_CT_UNTRACKED) {
1679                         NF_CT_STAT_INC_ATOMIC(state->net, ignore);
1680                         return NF_ACCEPT;
1681                 }
1682                 skb->_nfct = 0;
1683         }
1684
1685         /* rcu_read_lock()ed by nf_hook_thresh */
1686         dataoff = get_l4proto(skb, skb_network_offset(skb), state->pf, &protonum);
1687         if (dataoff <= 0) {
1688                 pr_debug("not prepared to track yet or error occurred\n");
1689                 NF_CT_STAT_INC_ATOMIC(state->net, error);
1690                 NF_CT_STAT_INC_ATOMIC(state->net, invalid);
1691                 ret = NF_ACCEPT;
1692                 goto out;
1693         }
1694
1695         if (protonum == IPPROTO_ICMP || protonum == IPPROTO_ICMPV6) {
1696                 ret = nf_conntrack_handle_icmp(tmpl, skb, dataoff,
1697                                                protonum, state);
1698                 if (ret <= 0) {
1699                         ret = -ret;
1700                         goto out;
1701                 }
1702                 /* ICMP[v6] protocol trackers may assign one conntrack. */
1703                 if (skb->_nfct)
1704                         goto out;
1705         }
1706 repeat:
1707         ret = resolve_normal_ct(tmpl, skb, dataoff,
1708                                 protonum, state);
1709         if (ret < 0) {
1710                 /* Too stressed to deal. */
1711                 NF_CT_STAT_INC_ATOMIC(state->net, drop);
1712                 ret = NF_DROP;
1713                 goto out;
1714         }
1715
1716         ct = nf_ct_get(skb, &ctinfo);
1717         if (!ct) {
1718                 /* Not valid part of a connection */
1719                 NF_CT_STAT_INC_ATOMIC(state->net, invalid);
1720                 ret = NF_ACCEPT;
1721                 goto out;
1722         }
1723
1724         ret = nf_conntrack_handle_packet(ct, skb, dataoff, ctinfo, state);
1725         if (ret <= 0) {
1726                 /* Invalid: inverse of the return code tells
1727                  * the netfilter core what to do */
1728                 pr_debug("nf_conntrack_in: Can't track with proto module\n");
1729                 nf_conntrack_put(&ct->ct_general);
1730                 skb->_nfct = 0;
1731                 NF_CT_STAT_INC_ATOMIC(state->net, invalid);
1732                 if (ret == -NF_DROP)
1733                         NF_CT_STAT_INC_ATOMIC(state->net, drop);
1734                 /* Special case: TCP tracker reports an attempt to reopen a
1735                  * closed/aborted connection. We have to go back and create a
1736                  * fresh conntrack.
1737                  */
1738                 if (ret == -NF_REPEAT)
1739                         goto repeat;
1740                 ret = -ret;
1741                 goto out;
1742         }
1743
1744         if (ctinfo == IP_CT_ESTABLISHED_REPLY &&
1745             !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
1746                 nf_conntrack_event_cache(IPCT_REPLY, ct);
1747 out:
1748         if (tmpl)
1749                 nf_ct_put(tmpl);
1750
1751         return ret;
1752 }
1753 EXPORT_SYMBOL_GPL(nf_conntrack_in);
1754
1755 /* Alter reply tuple (maybe alter helper).  This is for NAT, and is
1756    implicitly racy: see __nf_conntrack_confirm */
1757 void nf_conntrack_alter_reply(struct nf_conn *ct,
1758                               const struct nf_conntrack_tuple *newreply)
1759 {
1760         struct nf_conn_help *help = nfct_help(ct);
1761
1762         /* Should be unconfirmed, so not in hash table yet */
1763         WARN_ON(nf_ct_is_confirmed(ct));
1764
1765         pr_debug("Altering reply tuple of %p to ", ct);
1766         nf_ct_dump_tuple(newreply);
1767
1768         ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
1769         if (ct->master || (help && !hlist_empty(&help->expectations)))
1770                 return;
1771
1772         rcu_read_lock();
1773         __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
1774         rcu_read_unlock();
1775 }
1776 EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
1777
1778 /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
1779 void __nf_ct_refresh_acct(struct nf_conn *ct,
1780                           enum ip_conntrack_info ctinfo,
1781                           const struct sk_buff *skb,
1782                           u32 extra_jiffies,
1783                           bool do_acct)
1784 {
1785         /* Only update if this is not a fixed timeout */
1786         if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
1787                 goto acct;
1788
1789         /* If not in hash table, timer will not be active yet */
1790         if (nf_ct_is_confirmed(ct))
1791                 extra_jiffies += nfct_time_stamp;
1792
1793         if (READ_ONCE(ct->timeout) != extra_jiffies)
1794                 WRITE_ONCE(ct->timeout, extra_jiffies);
1795 acct:
1796         if (do_acct)
1797                 nf_ct_acct_update(ct, ctinfo, skb->len);
1798 }
1799 EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
1800
1801 bool nf_ct_kill_acct(struct nf_conn *ct,
1802                      enum ip_conntrack_info ctinfo,
1803                      const struct sk_buff *skb)
1804 {
1805         nf_ct_acct_update(ct, ctinfo, skb->len);
1806
1807         return nf_ct_delete(ct, 0, 0);
1808 }
1809 EXPORT_SYMBOL_GPL(nf_ct_kill_acct);
1810
1811 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1812
1813 #include <linux/netfilter/nfnetlink.h>
1814 #include <linux/netfilter/nfnetlink_conntrack.h>
1815 #include <linux/mutex.h>
1816
1817 /* Generic function for tcp/udp/sctp/dccp and alike. */
1818 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
1819                                const struct nf_conntrack_tuple *tuple)
1820 {
1821         if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
1822             nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
1823                 goto nla_put_failure;
1824         return 0;
1825
1826 nla_put_failure:
1827         return -1;
1828 }
1829 EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
1830
1831 const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
1832         [CTA_PROTO_SRC_PORT]  = { .type = NLA_U16 },
1833         [CTA_PROTO_DST_PORT]  = { .type = NLA_U16 },
1834 };
1835 EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
1836
1837 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
1838                                struct nf_conntrack_tuple *t)
1839 {
1840         if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
1841                 return -EINVAL;
1842
1843         t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
1844         t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
1845
1846         return 0;
1847 }
1848 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
1849
1850 unsigned int nf_ct_port_nlattr_tuple_size(void)
1851 {
1852         static unsigned int size __read_mostly;
1853
1854         if (!size)
1855                 size = nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1856
1857         return size;
1858 }
1859 EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
1860 #endif
1861
1862 /* Used by ipt_REJECT and ip6t_REJECT. */
1863 static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
1864 {
1865         struct nf_conn *ct;
1866         enum ip_conntrack_info ctinfo;
1867
1868         /* This ICMP is in reverse direction to the packet which caused it */
1869         ct = nf_ct_get(skb, &ctinfo);
1870         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
1871                 ctinfo = IP_CT_RELATED_REPLY;
1872         else
1873                 ctinfo = IP_CT_RELATED;
1874
1875         /* Attach to new skbuff, and increment count */
1876         nf_ct_set(nskb, ct, ctinfo);
1877         nf_conntrack_get(skb_nfct(nskb));
1878 }
1879
1880 static int nf_conntrack_update(struct net *net, struct sk_buff *skb)
1881 {
1882         struct nf_conntrack_tuple_hash *h;
1883         struct nf_conntrack_tuple tuple;
1884         enum ip_conntrack_info ctinfo;
1885         struct nf_nat_hook *nat_hook;
1886         unsigned int status;
1887         struct nf_conn *ct;
1888         int dataoff;
1889         u16 l3num;
1890         u8 l4num;
1891
1892         ct = nf_ct_get(skb, &ctinfo);
1893         if (!ct || nf_ct_is_confirmed(ct))
1894                 return 0;
1895
1896         l3num = nf_ct_l3num(ct);
1897
1898         dataoff = get_l4proto(skb, skb_network_offset(skb), l3num, &l4num);
1899         if (dataoff <= 0)
1900                 return -1;
1901
1902         if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
1903                              l4num, net, &tuple))
1904                 return -1;
1905
1906         if (ct->status & IPS_SRC_NAT) {
1907                 memcpy(tuple.src.u3.all,
1908                        ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.all,
1909                        sizeof(tuple.src.u3.all));
1910                 tuple.src.u.all =
1911                         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all;
1912         }
1913
1914         if (ct->status & IPS_DST_NAT) {
1915                 memcpy(tuple.dst.u3.all,
1916                        ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.all,
1917                        sizeof(tuple.dst.u3.all));
1918                 tuple.dst.u.all =
1919                         ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all;
1920         }
1921
1922         h = nf_conntrack_find_get(net, nf_ct_zone(ct), &tuple);
1923         if (!h)
1924                 return 0;
1925
1926         /* Store status bits of the conntrack that is clashing to re-do NAT
1927          * mangling according to what it has been done already to this packet.
1928          */
1929         status = ct->status;
1930
1931         nf_ct_put(ct);
1932         ct = nf_ct_tuplehash_to_ctrack(h);
1933         nf_ct_set(skb, ct, ctinfo);
1934
1935         nat_hook = rcu_dereference(nf_nat_hook);
1936         if (!nat_hook)
1937                 return 0;
1938
1939         if (status & IPS_SRC_NAT &&
1940             nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_SRC,
1941                                 IP_CT_DIR_ORIGINAL) == NF_DROP)
1942                 return -1;
1943
1944         if (status & IPS_DST_NAT &&
1945             nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_DST,
1946                                 IP_CT_DIR_ORIGINAL) == NF_DROP)
1947                 return -1;
1948
1949         return 0;
1950 }
1951
1952 static bool nf_conntrack_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
1953                                        const struct sk_buff *skb)
1954 {
1955         const struct nf_conntrack_tuple *src_tuple;
1956         const struct nf_conntrack_tuple_hash *hash;
1957         struct nf_conntrack_tuple srctuple;
1958         enum ip_conntrack_info ctinfo;
1959         struct nf_conn *ct;
1960
1961         ct = nf_ct_get(skb, &ctinfo);
1962         if (ct) {
1963                 src_tuple = nf_ct_tuple(ct, CTINFO2DIR(ctinfo));
1964                 memcpy(dst_tuple, src_tuple, sizeof(*dst_tuple));
1965                 return true;
1966         }
1967
1968         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
1969                                NFPROTO_IPV4, dev_net(skb->dev),
1970                                &srctuple))
1971                 return false;
1972
1973         hash = nf_conntrack_find_get(dev_net(skb->dev),
1974                                      &nf_ct_zone_dflt,
1975                                      &srctuple);
1976         if (!hash)
1977                 return false;
1978
1979         ct = nf_ct_tuplehash_to_ctrack(hash);
1980         src_tuple = nf_ct_tuple(ct, !hash->tuple.dst.dir);
1981         memcpy(dst_tuple, src_tuple, sizeof(*dst_tuple));
1982         nf_ct_put(ct);
1983
1984         return true;
1985 }
1986
1987 /* Bring out ya dead! */
1988 static struct nf_conn *
1989 get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
1990                 void *data, unsigned int *bucket)
1991 {
1992         struct nf_conntrack_tuple_hash *h;
1993         struct nf_conn *ct;
1994         struct hlist_nulls_node *n;
1995         spinlock_t *lockp;
1996
1997         for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
1998                 lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
1999                 local_bh_disable();
2000                 nf_conntrack_lock(lockp);
2001                 if (*bucket < nf_conntrack_htable_size) {
2002                         hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnnode) {
2003                                 if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
2004                                         continue;
2005                                 ct = nf_ct_tuplehash_to_ctrack(h);
2006                                 if (iter(ct, data))
2007                                         goto found;
2008                         }
2009                 }
2010                 spin_unlock(lockp);
2011                 local_bh_enable();
2012                 cond_resched();
2013         }
2014
2015         return NULL;
2016 found:
2017         atomic_inc(&ct->ct_general.use);
2018         spin_unlock(lockp);
2019         local_bh_enable();
2020         return ct;
2021 }
2022
2023 static void nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data),
2024                                   void *data, u32 portid, int report)
2025 {
2026         unsigned int bucket = 0, sequence;
2027         struct nf_conn *ct;
2028
2029         might_sleep();
2030
2031         for (;;) {
2032                 sequence = read_seqcount_begin(&nf_conntrack_generation);
2033
2034                 while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
2035                         /* Time to push up daises... */
2036
2037                         nf_ct_delete(ct, portid, report);
2038                         nf_ct_put(ct);
2039                         cond_resched();
2040                 }
2041
2042                 if (!read_seqcount_retry(&nf_conntrack_generation, sequence))
2043                         break;
2044                 bucket = 0;
2045         }
2046 }
2047
2048 struct iter_data {
2049         int (*iter)(struct nf_conn *i, void *data);
2050         void *data;
2051         struct net *net;
2052 };
2053
2054 static int iter_net_only(struct nf_conn *i, void *data)
2055 {
2056         struct iter_data *d = data;
2057
2058         if (!net_eq(d->net, nf_ct_net(i)))
2059                 return 0;
2060
2061         return d->iter(i, d->data);
2062 }
2063
2064 static void
2065 __nf_ct_unconfirmed_destroy(struct net *net)
2066 {
2067         int cpu;
2068
2069         for_each_possible_cpu(cpu) {
2070                 struct nf_conntrack_tuple_hash *h;
2071                 struct hlist_nulls_node *n;
2072                 struct ct_pcpu *pcpu;
2073
2074                 pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
2075
2076                 spin_lock_bh(&pcpu->lock);
2077                 hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
2078                         struct nf_conn *ct;
2079
2080                         ct = nf_ct_tuplehash_to_ctrack(h);
2081
2082                         /* we cannot call iter() on unconfirmed list, the
2083                          * owning cpu can reallocate ct->ext at any time.
2084                          */
2085                         set_bit(IPS_DYING_BIT, &ct->status);
2086                 }
2087                 spin_unlock_bh(&pcpu->lock);
2088                 cond_resched();
2089         }
2090 }
2091
2092 void nf_ct_unconfirmed_destroy(struct net *net)
2093 {
2094         might_sleep();
2095
2096         if (atomic_read(&net->ct.count) > 0) {
2097                 __nf_ct_unconfirmed_destroy(net);
2098                 nf_queue_nf_hook_drop(net);
2099                 synchronize_net();
2100         }
2101 }
2102 EXPORT_SYMBOL_GPL(nf_ct_unconfirmed_destroy);
2103
2104 void nf_ct_iterate_cleanup_net(struct net *net,
2105                                int (*iter)(struct nf_conn *i, void *data),
2106                                void *data, u32 portid, int report)
2107 {
2108         struct iter_data d;
2109
2110         might_sleep();
2111
2112         if (atomic_read(&net->ct.count) == 0)
2113                 return;
2114
2115         d.iter = iter;
2116         d.data = data;
2117         d.net = net;
2118
2119         nf_ct_iterate_cleanup(iter_net_only, &d, portid, report);
2120 }
2121 EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup_net);
2122
2123 /**
2124  * nf_ct_iterate_destroy - destroy unconfirmed conntracks and iterate table
2125  * @iter: callback to invoke for each conntrack
2126  * @data: data to pass to @iter
2127  *
2128  * Like nf_ct_iterate_cleanup, but first marks conntracks on the
2129  * unconfirmed list as dying (so they will not be inserted into
2130  * main table).
2131  *
2132  * Can only be called in module exit path.
2133  */
2134 void
2135 nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data), void *data)
2136 {
2137         struct net *net;
2138
2139         down_read(&net_rwsem);
2140         for_each_net(net) {
2141                 if (atomic_read(&net->ct.count) == 0)
2142                         continue;
2143                 __nf_ct_unconfirmed_destroy(net);
2144                 nf_queue_nf_hook_drop(net);
2145         }
2146         up_read(&net_rwsem);
2147
2148         /* Need to wait for netns cleanup worker to finish, if its
2149          * running -- it might have deleted a net namespace from
2150          * the global list, so our __nf_ct_unconfirmed_destroy() might
2151          * not have affected all namespaces.
2152          */
2153         net_ns_barrier();
2154
2155         /* a conntrack could have been unlinked from unconfirmed list
2156          * before we grabbed pcpu lock in __nf_ct_unconfirmed_destroy().
2157          * This makes sure its inserted into conntrack table.
2158          */
2159         synchronize_net();
2160
2161         nf_ct_iterate_cleanup(iter, data, 0, 0);
2162 }
2163 EXPORT_SYMBOL_GPL(nf_ct_iterate_destroy);
2164
2165 static int kill_all(struct nf_conn *i, void *data)
2166 {
2167         return net_eq(nf_ct_net(i), data);
2168 }
2169
2170 void nf_conntrack_cleanup_start(void)
2171 {
2172         conntrack_gc_work.exiting = true;
2173         RCU_INIT_POINTER(ip_ct_attach, NULL);
2174 }
2175
2176 void nf_conntrack_cleanup_end(void)
2177 {
2178         RCU_INIT_POINTER(nf_ct_hook, NULL);
2179         cancel_delayed_work_sync(&conntrack_gc_work.dwork);
2180         kvfree(nf_conntrack_hash);
2181
2182         nf_conntrack_proto_fini();
2183         nf_conntrack_seqadj_fini();
2184         nf_conntrack_labels_fini();
2185         nf_conntrack_helper_fini();
2186         nf_conntrack_timeout_fini();
2187         nf_conntrack_ecache_fini();
2188         nf_conntrack_tstamp_fini();
2189         nf_conntrack_acct_fini();
2190         nf_conntrack_expect_fini();
2191
2192         kmem_cache_destroy(nf_conntrack_cachep);
2193 }
2194
2195 /*
2196  * Mishearing the voices in his head, our hero wonders how he's
2197  * supposed to kill the mall.
2198  */
2199 void nf_conntrack_cleanup_net(struct net *net)
2200 {
2201         LIST_HEAD(single);
2202
2203         list_add(&net->exit_list, &single);
2204         nf_conntrack_cleanup_net_list(&single);
2205 }
2206
2207 void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
2208 {
2209         int busy;
2210         struct net *net;
2211
2212         /*
2213          * This makes sure all current packets have passed through
2214          *  netfilter framework.  Roll on, two-stage module
2215          *  delete...
2216          */
2217         synchronize_net();
2218 i_see_dead_people:
2219         busy = 0;
2220         list_for_each_entry(net, net_exit_list, exit_list) {
2221                 nf_ct_iterate_cleanup(kill_all, net, 0, 0);
2222                 if (atomic_read(&net->ct.count) != 0)
2223                         busy = 1;
2224         }
2225         if (busy) {
2226                 schedule();
2227                 goto i_see_dead_people;
2228         }
2229
2230         list_for_each_entry(net, net_exit_list, exit_list) {
2231                 nf_conntrack_proto_pernet_fini(net);
2232                 nf_conntrack_ecache_pernet_fini(net);
2233                 nf_conntrack_expect_pernet_fini(net);
2234                 free_percpu(net->ct.stat);
2235                 free_percpu(net->ct.pcpu_lists);
2236         }
2237 }
2238
2239 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
2240 {
2241         struct hlist_nulls_head *hash;
2242         unsigned int nr_slots, i;
2243
2244         if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
2245                 return NULL;
2246
2247         BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
2248         nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
2249
2250         hash = kvmalloc_array(nr_slots, sizeof(struct hlist_nulls_head),
2251                               GFP_KERNEL | __GFP_ZERO);
2252
2253         if (hash && nulls)
2254                 for (i = 0; i < nr_slots; i++)
2255                         INIT_HLIST_NULLS_HEAD(&hash[i], i);
2256
2257         return hash;
2258 }
2259 EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
2260
2261 int nf_conntrack_hash_resize(unsigned int hashsize)
2262 {
2263         int i, bucket;
2264         unsigned int old_size;
2265         struct hlist_nulls_head *hash, *old_hash;
2266         struct nf_conntrack_tuple_hash *h;
2267         struct nf_conn *ct;
2268
2269         if (!hashsize)
2270                 return -EINVAL;
2271
2272         hash = nf_ct_alloc_hashtable(&hashsize, 1);
2273         if (!hash)
2274                 return -ENOMEM;
2275
2276         old_size = nf_conntrack_htable_size;
2277         if (old_size == hashsize) {
2278                 kvfree(hash);
2279                 return 0;
2280         }
2281
2282         local_bh_disable();
2283         nf_conntrack_all_lock();
2284         write_seqcount_begin(&nf_conntrack_generation);
2285
2286         /* Lookups in the old hash might happen in parallel, which means we
2287          * might get false negatives during connection lookup. New connections
2288          * created because of a false negative won't make it into the hash
2289          * though since that required taking the locks.
2290          */
2291
2292         for (i = 0; i < nf_conntrack_htable_size; i++) {
2293                 while (!hlist_nulls_empty(&nf_conntrack_hash[i])) {
2294                         h = hlist_nulls_entry(nf_conntrack_hash[i].first,
2295                                               struct nf_conntrack_tuple_hash, hnnode);
2296                         ct = nf_ct_tuplehash_to_ctrack(h);
2297                         hlist_nulls_del_rcu(&h->hnnode);
2298                         bucket = __hash_conntrack(nf_ct_net(ct),
2299                                                   &h->tuple, hashsize);
2300                         hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
2301                 }
2302         }
2303         old_size = nf_conntrack_htable_size;
2304         old_hash = nf_conntrack_hash;
2305
2306         nf_conntrack_hash = hash;
2307         nf_conntrack_htable_size = hashsize;
2308
2309         write_seqcount_end(&nf_conntrack_generation);
2310         nf_conntrack_all_unlock();
2311         local_bh_enable();
2312
2313         synchronize_net();
2314         kvfree(old_hash);
2315         return 0;
2316 }
2317
2318 int nf_conntrack_set_hashsize(const char *val, const struct kernel_param *kp)
2319 {
2320         unsigned int hashsize;
2321         int rc;
2322
2323         if (current->nsproxy->net_ns != &init_net)
2324                 return -EOPNOTSUPP;
2325
2326         /* On boot, we can set this without any fancy locking. */
2327         if (!nf_conntrack_hash)
2328                 return param_set_uint(val, kp);
2329
2330         rc = kstrtouint(val, 0, &hashsize);
2331         if (rc)
2332                 return rc;
2333
2334         return nf_conntrack_hash_resize(hashsize);
2335 }
2336 EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
2337
2338 static __always_inline unsigned int total_extension_size(void)
2339 {
2340         /* remember to add new extensions below */
2341         BUILD_BUG_ON(NF_CT_EXT_NUM > 9);
2342
2343         return sizeof(struct nf_ct_ext) +
2344                sizeof(struct nf_conn_help)
2345 #if IS_ENABLED(CONFIG_NF_NAT)
2346                 + sizeof(struct nf_conn_nat)
2347 #endif
2348                 + sizeof(struct nf_conn_seqadj)
2349                 + sizeof(struct nf_conn_acct)
2350 #ifdef CONFIG_NF_CONNTRACK_EVENTS
2351                 + sizeof(struct nf_conntrack_ecache)
2352 #endif
2353 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
2354                 + sizeof(struct nf_conn_tstamp)
2355 #endif
2356 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
2357                 + sizeof(struct nf_conn_timeout)
2358 #endif
2359 #ifdef CONFIG_NF_CONNTRACK_LABELS
2360                 + sizeof(struct nf_conn_labels)
2361 #endif
2362 #if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
2363                 + sizeof(struct nf_conn_synproxy)
2364 #endif
2365         ;
2366 };
2367
2368 int nf_conntrack_init_start(void)
2369 {
2370         unsigned long nr_pages = totalram_pages();
2371         int max_factor = 8;
2372         int ret = -ENOMEM;
2373         int i;
2374
2375         /* struct nf_ct_ext uses u8 to store offsets/size */
2376         BUILD_BUG_ON(total_extension_size() > 255u);
2377
2378         seqcount_init(&nf_conntrack_generation);
2379
2380         for (i = 0; i < CONNTRACK_LOCKS; i++)
2381                 spin_lock_init(&nf_conntrack_locks[i]);
2382
2383         if (!nf_conntrack_htable_size) {
2384                 /* Idea from tcp.c: use 1/16384 of memory.
2385                  * On i386: 32MB machine has 512 buckets.
2386                  * >= 1GB machines have 16384 buckets.
2387                  * >= 4GB machines have 65536 buckets.
2388                  */
2389                 nf_conntrack_htable_size
2390                         = (((nr_pages << PAGE_SHIFT) / 16384)
2391                            / sizeof(struct hlist_head));
2392                 if (nr_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
2393                         nf_conntrack_htable_size = 65536;
2394                 else if (nr_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
2395                         nf_conntrack_htable_size = 16384;
2396                 if (nf_conntrack_htable_size < 32)
2397                         nf_conntrack_htable_size = 32;
2398
2399                 /* Use a max. factor of four by default to get the same max as
2400                  * with the old struct list_heads. When a table size is given
2401                  * we use the old value of 8 to avoid reducing the max.
2402                  * entries. */
2403                 max_factor = 4;
2404         }
2405
2406         nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, 1);
2407         if (!nf_conntrack_hash)
2408                 return -ENOMEM;
2409
2410         nf_conntrack_max = max_factor * nf_conntrack_htable_size;
2411
2412         nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
2413                                                 sizeof(struct nf_conn),
2414                                                 NFCT_INFOMASK + 1,
2415                                                 SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
2416         if (!nf_conntrack_cachep)
2417                 goto err_cachep;
2418
2419         ret = nf_conntrack_expect_init();
2420         if (ret < 0)
2421                 goto err_expect;
2422
2423         ret = nf_conntrack_acct_init();
2424         if (ret < 0)
2425                 goto err_acct;
2426
2427         ret = nf_conntrack_tstamp_init();
2428         if (ret < 0)
2429                 goto err_tstamp;
2430
2431         ret = nf_conntrack_ecache_init();
2432         if (ret < 0)
2433                 goto err_ecache;
2434
2435         ret = nf_conntrack_timeout_init();
2436         if (ret < 0)
2437                 goto err_timeout;
2438
2439         ret = nf_conntrack_helper_init();
2440         if (ret < 0)
2441                 goto err_helper;
2442
2443         ret = nf_conntrack_labels_init();
2444         if (ret < 0)
2445                 goto err_labels;
2446
2447         ret = nf_conntrack_seqadj_init();
2448         if (ret < 0)
2449                 goto err_seqadj;
2450
2451         ret = nf_conntrack_proto_init();
2452         if (ret < 0)
2453                 goto err_proto;
2454
2455         conntrack_gc_work_init(&conntrack_gc_work);
2456         queue_delayed_work(system_power_efficient_wq, &conntrack_gc_work.dwork, HZ);
2457
2458         return 0;
2459
2460 err_proto:
2461         nf_conntrack_seqadj_fini();
2462 err_seqadj:
2463         nf_conntrack_labels_fini();
2464 err_labels:
2465         nf_conntrack_helper_fini();
2466 err_helper:
2467         nf_conntrack_timeout_fini();
2468 err_timeout:
2469         nf_conntrack_ecache_fini();
2470 err_ecache:
2471         nf_conntrack_tstamp_fini();
2472 err_tstamp:
2473         nf_conntrack_acct_fini();
2474 err_acct:
2475         nf_conntrack_expect_fini();
2476 err_expect:
2477         kmem_cache_destroy(nf_conntrack_cachep);
2478 err_cachep:
2479         kvfree(nf_conntrack_hash);
2480         return ret;
2481 }
2482
2483 static struct nf_ct_hook nf_conntrack_hook = {
2484         .update         = nf_conntrack_update,
2485         .destroy        = destroy_conntrack,
2486         .get_tuple_skb  = nf_conntrack_get_tuple_skb,
2487 };
2488
2489 void nf_conntrack_init_end(void)
2490 {
2491         /* For use by REJECT target */
2492         RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
2493         RCU_INIT_POINTER(nf_ct_hook, &nf_conntrack_hook);
2494 }
2495
2496 /*
2497  * We need to use special "null" values, not used in hash table
2498  */
2499 #define UNCONFIRMED_NULLS_VAL   ((1<<30)+0)
2500 #define DYING_NULLS_VAL         ((1<<30)+1)
2501 #define TEMPLATE_NULLS_VAL      ((1<<30)+2)
2502
2503 int nf_conntrack_init_net(struct net *net)
2504 {
2505         int ret = -ENOMEM;
2506         int cpu;
2507
2508         BUILD_BUG_ON(IP_CT_UNTRACKED == IP_CT_NUMBER);
2509         BUILD_BUG_ON_NOT_POWER_OF_2(CONNTRACK_LOCKS);
2510         atomic_set(&net->ct.count, 0);
2511
2512         net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
2513         if (!net->ct.pcpu_lists)
2514                 goto err_stat;
2515
2516         for_each_possible_cpu(cpu) {
2517                 struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
2518
2519                 spin_lock_init(&pcpu->lock);
2520                 INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
2521                 INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
2522         }
2523
2524         net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
2525         if (!net->ct.stat)
2526                 goto err_pcpu_lists;
2527
2528         ret = nf_conntrack_expect_pernet_init(net);
2529         if (ret < 0)
2530                 goto err_expect;
2531
2532         nf_conntrack_acct_pernet_init(net);
2533         nf_conntrack_tstamp_pernet_init(net);
2534         nf_conntrack_ecache_pernet_init(net);
2535         nf_conntrack_helper_pernet_init(net);
2536         nf_conntrack_proto_pernet_init(net);
2537
2538         return 0;
2539
2540 err_expect:
2541         free_percpu(net->ct.stat);
2542 err_pcpu_lists:
2543         free_percpu(net->ct.pcpu_lists);
2544 err_stat:
2545         return ret;
2546 }