net/sched/act_ct.c

   1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
   2 /* -
   3  * net/sched/act_ct.c  Connection Tracking action
   4  *
   5  * Authors:   Paul Blakey <paulb@mellanox.com>
   6  *            Yossi Kuperman <yossiku@mellanox.com>
   7  *            Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/rtnetlink.h>
  15 #include <linux/pkt_cls.h>
  16 #include <linux/ip.h>
  17 #include <linux/ipv6.h>
  18 #include <linux/rhashtable.h>
  19 #include <net/netlink.h>
  20 #include <net/pkt_sched.h>
  21 #include <net/pkt_cls.h>
  22 #include <net/act_api.h>
  23 #include <net/ip.h>
  24 #include <net/ipv6_frag.h>
  25 #include <uapi/linux/tc_act/tc_ct.h>
  26 #include <net/tc_act/tc_ct.h>
  27
  28 #include <net/netfilter/nf_flow_table.h>
  29 #include <net/netfilter/nf_conntrack.h>
  30 #include <net/netfilter/nf_conntrack_core.h>
  31 #include <net/netfilter/nf_conntrack_zones.h>
  32 #include <net/netfilter/nf_conntrack_helper.h>
  33 #include <net/netfilter/nf_conntrack_acct.h>
  34 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  35 #include <uapi/linux/netfilter/nf_nat.h>
  36
  37 static struct workqueue_struct *act_ct_wq;
  38 static struct rhashtable zones_ht;
  39 static DEFINE_MUTEX(zones_mutex);
  40
  41 struct tcf_ct_flow_table {
  42         struct rhash_head node; /* In zones tables */
  43
  44         struct rcu_work rwork;
  45         struct nf_flowtable nf_ft;
  46         refcount_t ref;
  47         u16 zone;
  48
  49         bool dying;
  50 };
  51
  52 static const struct rhashtable_params zones_params = {
  53         .head_offset = offsetof(struct tcf_ct_flow_table, node),
  54         .key_offset = offsetof(struct tcf_ct_flow_table, zone),
  55         .key_len = sizeof_field(struct tcf_ct_flow_table, zone),
  56         .automatic_shrinking = true,
  57 };
  58
  59 static struct flow_action_entry *
  60 tcf_ct_flow_table_flow_action_get_next(struct flow_action *flow_action)
  61 {
  62         int i = flow_action->num_entries++;
  63
  64         return &flow_action->entries[i];
  65 }
  66
  67 static void tcf_ct_add_mangle_action(struct flow_action *action,
  68                                      enum flow_action_mangle_base htype,
  69                                      u32 offset,
  70                                      u32 mask,
  71                                      u32 val)
  72 {
  73         struct flow_action_entry *entry;
  74
  75         entry = tcf_ct_flow_table_flow_action_get_next(action);
  76         entry->id = FLOW_ACTION_MANGLE;
  77         entry->mangle.htype = htype;
  78         entry->mangle.mask = ~mask;
  79         entry->mangle.offset = offset;
  80         entry->mangle.val = val;
  81 }
  82
  83 /* The following nat helper functions check if the inverted reverse tuple
  84  * (target) is different then the current dir tuple - meaning nat for ports
  85  * and/or ip is needed, and add the relevant mangle actions.
  86  */
  87 static void
  88 tcf_ct_flow_table_add_action_nat_ipv4(const struct nf_conntrack_tuple *tuple,
  89                                       struct nf_conntrack_tuple target,
  90                                       struct flow_action *action)
  91 {
  92         if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3)))
  93                 tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4,
  94                                          offsetof(struct iphdr, saddr),
  95                                          0xFFFFFFFF,
  96                                          be32_to_cpu(target.src.u3.ip));
  97         if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3)))
  98                 tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4,
  99                                          offsetof(struct iphdr, daddr),
 100                                          0xFFFFFFFF,
 101                                          be32_to_cpu(target.dst.u3.ip));
 102 }
 103
 104 static void
 105 tcf_ct_add_ipv6_addr_mangle_action(struct flow_action *action,
 106                                    union nf_inet_addr *addr,
 107                                    u32 offset)
 108 {
 109         int i;
 110
 111         for (i = 0; i < sizeof(struct in6_addr) / sizeof(u32); i++)
 112                 tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP6,
 113                                          i * sizeof(u32) + offset,
 114                                          0xFFFFFFFF, be32_to_cpu(addr->ip6[i]));
 115 }
 116
 117 static void
 118 tcf_ct_flow_table_add_action_nat_ipv6(const struct nf_conntrack_tuple *tuple,
 119                                       struct nf_conntrack_tuple target,
 120                                       struct flow_action *action)
 121 {
 122         if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3)))
 123                 tcf_ct_add_ipv6_addr_mangle_action(action, &target.src.u3,
 124                                                    offsetof(struct ipv6hdr,
 125                                                             saddr));
 126         if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3)))
 127                 tcf_ct_add_ipv6_addr_mangle_action(action, &target.dst.u3,
 128                                                    offsetof(struct ipv6hdr,
 129                                                             daddr));
 130 }
 131
 132 static void
 133 tcf_ct_flow_table_add_action_nat_tcp(const struct nf_conntrack_tuple *tuple,
 134                                      struct nf_conntrack_tuple target,
 135                                      struct flow_action *action)
 136 {
 137         __be16 target_src = target.src.u.tcp.port;
 138         __be16 target_dst = target.dst.u.tcp.port;
 139
 140         if (target_src != tuple->src.u.tcp.port)
 141                 tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
 142                                          offsetof(struct tcphdr, source),
 143                                          0xFFFF, be16_to_cpu(target_src));
 144         if (target_dst != tuple->dst.u.tcp.port)
 145                 tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
 146                                          offsetof(struct tcphdr, dest),
 147                                          0xFFFF, be16_to_cpu(target_dst));
 148 }
 149
 150 static void
 151 tcf_ct_flow_table_add_action_nat_udp(const struct nf_conntrack_tuple *tuple,
 152                                      struct nf_conntrack_tuple target,
 153                                      struct flow_action *action)
 154 {
 155         __be16 target_src = target.src.u.udp.port;
 156         __be16 target_dst = target.dst.u.udp.port;
 157
 158         if (target_src != tuple->src.u.udp.port)
 159                 tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_UDP,
 160                                          offsetof(struct udphdr, source),
 161                                          0xFFFF, be16_to_cpu(target_src));
 162         if (target_dst != tuple->dst.u.udp.port)
 163                 tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_UDP,
 164                                          offsetof(struct udphdr, dest),
 165                                          0xFFFF, be16_to_cpu(target_dst));
 166 }
 167
 168 static void tcf_ct_flow_table_add_action_meta(struct nf_conn *ct,
 169                                               enum ip_conntrack_dir dir,
 170                                               struct flow_action *action)
 171 {
 172         struct nf_conn_labels *ct_labels;
 173         struct flow_action_entry *entry;
 174         enum ip_conntrack_info ctinfo;
 175         u32 *act_ct_labels;
 176
 177         entry = tcf_ct_flow_table_flow_action_get_next(action);
 178         entry->id = FLOW_ACTION_CT_METADATA;
 179 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 180         entry->ct_metadata.mark = ct->mark;
 181 #endif
 182         ctinfo = dir == IP_CT_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
 183                                              IP_CT_ESTABLISHED_REPLY;
 184         /* aligns with the CT reference on the SKB nf_ct_set */
 185         entry->ct_metadata.cookie = (unsigned long)ct | ctinfo;
 186
 187         act_ct_labels = entry->ct_metadata.labels;
 188         ct_labels = nf_ct_labels_find(ct);
 189         if (ct_labels)
 190                 memcpy(act_ct_labels, ct_labels->bits, NF_CT_LABELS_MAX_SIZE);
 191         else
 192                 memset(act_ct_labels, 0, NF_CT_LABELS_MAX_SIZE);
 193 }
 194
 195 static int tcf_ct_flow_table_add_action_nat(struct net *net,
 196                                             struct nf_conn *ct,
 197                                             enum ip_conntrack_dir dir,
 198                                             struct flow_action *action)
 199 {
 200         const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
 201         struct nf_conntrack_tuple target;
 202
 203         if (!(ct->status & IPS_NAT_MASK))
 204                 return 0;
 205
 206         nf_ct_invert_tuple(&target, &ct->tuplehash[!dir].tuple);
 207
 208         switch (tuple->src.l3num) {
 209         case NFPROTO_IPV4:
 210                 tcf_ct_flow_table_add_action_nat_ipv4(tuple, target,
 211                                                       action);
 212                 break;
 213         case NFPROTO_IPV6:
 214                 tcf_ct_flow_table_add_action_nat_ipv6(tuple, target,
 215                                                       action);
 216                 break;
 217         default:
 218                 return -EOPNOTSUPP;
 219         }
 220
 221         switch (nf_ct_protonum(ct)) {
 222         case IPPROTO_TCP:
 223                 tcf_ct_flow_table_add_action_nat_tcp(tuple, target, action);
 224                 break;
 225         case IPPROTO_UDP:
 226                 tcf_ct_flow_table_add_action_nat_udp(tuple, target, action);
 227                 break;
 228         default:
 229                 return -EOPNOTSUPP;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static int tcf_ct_flow_table_fill_actions(struct net *net,
 236                                           const struct flow_offload *flow,
 237                                           enum flow_offload_tuple_dir tdir,
 238                                           struct nf_flow_rule *flow_rule)
 239 {
 240         struct flow_action *action = &flow_rule->rule->action;
 241         int num_entries = action->num_entries;
 242         struct nf_conn *ct = flow->ct;
 243         enum ip_conntrack_dir dir;
 244         int i, err;
 245
 246         switch (tdir) {
 247         case FLOW_OFFLOAD_DIR_ORIGINAL:
 248                 dir = IP_CT_DIR_ORIGINAL;
 249                 break;
 250         case FLOW_OFFLOAD_DIR_REPLY:
 251                 dir = IP_CT_DIR_REPLY;
 252                 break;
 253         default:
 254                 return -EOPNOTSUPP;
 255         }
 256
 257         err = tcf_ct_flow_table_add_action_nat(net, ct, dir, action);
 258         if (err)
 259                 goto err_nat;
 260
 261         tcf_ct_flow_table_add_action_meta(ct, dir, action);
 262         return 0;
 263
 264 err_nat:
 265         /* Clear filled actions */
 266         for (i = num_entries; i < action->num_entries; i++)
 267                 memset(&action->entries[i], 0, sizeof(action->entries[i]));
 268         action->num_entries = num_entries;
 269
 270         return err;
 271 }
 272
 273 static struct nf_flowtable_type flowtable_ct = {
 274         .action         = tcf_ct_flow_table_fill_actions,
 275         .owner          = THIS_MODULE,
 276 };
 277
 278 static int tcf_ct_flow_table_get(struct tcf_ct_params *params)
 279 {
 280         struct tcf_ct_flow_table *ct_ft;
 281         int err = -ENOMEM;
 282
 283         mutex_lock(&zones_mutex);
 284         ct_ft = rhashtable_lookup_fast(&zones_ht, &params->zone, zones_params);
 285         if (ct_ft && refcount_inc_not_zero(&ct_ft->ref))
 286                 goto out_unlock;
 287
 288         ct_ft = kzalloc(sizeof(*ct_ft), GFP_KERNEL);
 289         if (!ct_ft)
 290                 goto err_alloc;
 291         refcount_set(&ct_ft->ref, 1);
 292
 293         ct_ft->zone = params->zone;
 294         err = rhashtable_insert_fast(&zones_ht, &ct_ft->node, zones_params);
 295         if (err)
 296                 goto err_insert;
 297
 298         ct_ft->nf_ft.type = &flowtable_ct;
 299         ct_ft->nf_ft.flags |= NF_FLOWTABLE_HW_OFFLOAD |
 300                               NF_FLOWTABLE_COUNTER;
 301         err = nf_flow_table_init(&ct_ft->nf_ft);
 302         if (err)
 303                 goto err_init;
 304
 305         __module_get(THIS_MODULE);
 306 out_unlock:
 307         params->ct_ft = ct_ft;
 308         params->nf_ft = &ct_ft->nf_ft;
 309         mutex_unlock(&zones_mutex);
 310
 311         return 0;
 312
 313 err_init:
 314         rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params);
 315 err_insert:
 316         kfree(ct_ft);
 317 err_alloc:
 318         mutex_unlock(&zones_mutex);
 319         return err;
 320 }
 321
 322 static void tcf_ct_flow_table_cleanup_work(struct work_struct *work)
 323 {
 324         struct tcf_ct_flow_table *ct_ft;
 325
 326         ct_ft = container_of(to_rcu_work(work), struct tcf_ct_flow_table,
 327                              rwork);
 328         nf_flow_table_free(&ct_ft->nf_ft);
 329         kfree(ct_ft);
 330
 331         module_put(THIS_MODULE);
 332 }
 333
 334 static void tcf_ct_flow_table_put(struct tcf_ct_params *params)
 335 {
 336         struct tcf_ct_flow_table *ct_ft = params->ct_ft;
 337
 338         if (refcount_dec_and_test(&params->ct_ft->ref)) {
 339                 rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params);
 340                 INIT_RCU_WORK(&ct_ft->rwork, tcf_ct_flow_table_cleanup_work);
 341                 queue_rcu_work(act_ct_wq, &ct_ft->rwork);
 342         }
 343 }
 344
 345 static void tcf_ct_flow_table_add(struct tcf_ct_flow_table *ct_ft,
 346                                   struct nf_conn *ct,
 347                                   bool tcp)
 348 {
 349         struct flow_offload *entry;
 350         int err;
 351
 352         if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
 353                 return;
 354
 355         entry = flow_offload_alloc(ct);
 356         if (!entry) {
 357                 WARN_ON_ONCE(1);
 358                 goto err_alloc;
 359         }
 360
 361         if (tcp) {
 362                 ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
 363                 ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
 364         }
 365
 366         err = flow_offload_add(&ct_ft->nf_ft, entry);
 367         if (err)
 368                 goto err_add;
 369
 370         return;
 371
 372 err_add:
 373         flow_offload_free(entry);
 374 err_alloc:
 375         clear_bit(IPS_OFFLOAD_BIT, &ct->status);
 376 }
 377
 378 static void tcf_ct_flow_table_process_conn(struct tcf_ct_flow_table *ct_ft,
 379                                            struct nf_conn *ct,
 380                                            enum ip_conntrack_info ctinfo)
 381 {
 382         bool tcp = false;
 383
 384         if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
 385                 return;
 386
 387         switch (nf_ct_protonum(ct)) {
 388         case IPPROTO_TCP:
 389                 tcp = true;
 390                 if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED)
 391                         return;
 392                 break;
 393         case IPPROTO_UDP:
 394                 break;
 395         default:
 396                 return;
 397         }
 398
 399         if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
 400             ct->status & IPS_SEQ_ADJUST)
 401                 return;
 402
 403         tcf_ct_flow_table_add(ct_ft, ct, tcp);
 404 }
 405
 406 static bool
 407 tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,
 408                                   struct flow_offload_tuple *tuple,
 409                                   struct tcphdr **tcph)
 410 {
 411         struct flow_ports *ports;
 412         unsigned int thoff;
 413         struct iphdr *iph;
 414
 415         if (!pskb_network_may_pull(skb, sizeof(*iph)))
 416                 return false;
 417
 418         iph = ip_hdr(skb);
 419         thoff = iph->ihl * 4;
 420
 421         if (ip_is_fragment(iph) ||
 422             unlikely(thoff != sizeof(struct iphdr)))
 423                 return false;
 424
 425         if (iph->protocol != IPPROTO_TCP &&
 426             iph->protocol != IPPROTO_UDP)
 427                 return false;
 428
 429         if (iph->ttl <= 1)
 430                 return false;
 431
 432         if (!pskb_network_may_pull(skb, iph->protocol == IPPROTO_TCP ?
 433                                         thoff + sizeof(struct tcphdr) :
 434                                         thoff + sizeof(*ports)))
 435                 return false;
 436
 437         iph = ip_hdr(skb);
 438         if (iph->protocol == IPPROTO_TCP)
 439                 *tcph = (void *)(skb_network_header(skb) + thoff);
 440
 441         ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
 442         tuple->src_v4.s_addr = iph->saddr;
 443         tuple->dst_v4.s_addr = iph->daddr;
 444         tuple->src_port = ports->source;
 445         tuple->dst_port = ports->dest;
 446         tuple->l3proto = AF_INET;
 447         tuple->l4proto = iph->protocol;
 448
 449         return true;
 450 }
 451
 452 static bool
 453 tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb,
 454                                   struct flow_offload_tuple *tuple,
 455                                   struct tcphdr **tcph)
 456 {
 457         struct flow_ports *ports;
 458         struct ipv6hdr *ip6h;
 459         unsigned int thoff;
 460
 461         if (!pskb_network_may_pull(skb, sizeof(*ip6h)))
 462                 return false;
 463
 464         ip6h = ipv6_hdr(skb);
 465
 466         if (ip6h->nexthdr != IPPROTO_TCP &&
 467             ip6h->nexthdr != IPPROTO_UDP)
 468                 return false;
 469
 470         if (ip6h->hop_limit <= 1)
 471                 return false;
 472
 473         thoff = sizeof(*ip6h);
 474         if (!pskb_network_may_pull(skb, ip6h->nexthdr == IPPROTO_TCP ?
 475                                         thoff + sizeof(struct tcphdr) :
 476                                         thoff + sizeof(*ports)))
 477                 return false;
 478
 479         ip6h = ipv6_hdr(skb);
 480         if (ip6h->nexthdr == IPPROTO_TCP)
 481                 *tcph = (void *)(skb_network_header(skb) + thoff);
 482
 483         ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
 484         tuple->src_v6 = ip6h->saddr;
 485         tuple->dst_v6 = ip6h->daddr;
 486         tuple->src_port = ports->source;
 487         tuple->dst_port = ports->dest;
 488         tuple->l3proto = AF_INET6;
 489         tuple->l4proto = ip6h->nexthdr;
 490
 491         return true;
 492 }
 493
 494 static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
 495                                      struct sk_buff *skb,
 496                                      u8 family)
 497 {
 498         struct nf_flowtable *nf_ft = &p->ct_ft->nf_ft;
 499         struct flow_offload_tuple_rhash *tuplehash;
 500         struct flow_offload_tuple tuple = {};
 501         enum ip_conntrack_info ctinfo;
 502         struct tcphdr *tcph = NULL;
 503         struct flow_offload *flow;
 504         struct nf_conn *ct;
 505         u8 dir;
 506
 507         /* Previously seen or loopback */
 508         ct = nf_ct_get(skb, &ctinfo);
 509         if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
 510                 return false;
 511
 512         switch (family) {
 513         case NFPROTO_IPV4:
 514                 if (!tcf_ct_flow_table_fill_tuple_ipv4(skb, &tuple, &tcph))
 515                         return false;
 516                 break;
 517         case NFPROTO_IPV6:
 518                 if (!tcf_ct_flow_table_fill_tuple_ipv6(skb, &tuple, &tcph))
 519                         return false;
 520                 break;
 521         default:
 522                 return false;
 523         }
 524
 525         tuplehash = flow_offload_lookup(nf_ft, &tuple);
 526         if (!tuplehash)
 527                 return false;
 528
 529         dir = tuplehash->tuple.dir;
 530         flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 531         ct = flow->ct;
 532
 533         if (tcph && (unlikely(tcph->fin || tcph->rst))) {
 534                 flow_offload_teardown(flow);
 535                 return false;
 536         }
 537
 538         ctinfo = dir == FLOW_OFFLOAD_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
 539                                                     IP_CT_ESTABLISHED_REPLY;
 540
 541         flow_offload_refresh(nf_ft, flow);
 542         nf_conntrack_get(&ct->ct_general);
 543         nf_ct_set(skb, ct, ctinfo);
 544         if (nf_ft->flags & NF_FLOWTABLE_COUNTER)
 545                 nf_ct_acct_update(ct, dir, skb->len);
 546
 547         return true;
 548 }
 549
 550 static int tcf_ct_flow_tables_init(void)
 551 {
 552         return rhashtable_init(&zones_ht, &zones_params);
 553 }
 554
 555 static void tcf_ct_flow_tables_uninit(void)
 556 {
 557         rhashtable_destroy(&zones_ht);
 558 }
 559
 560 static struct tc_action_ops act_ct_ops;
 561 static unsigned int ct_net_id;
 562
 563 struct tc_ct_action_net {
 564         struct tc_action_net tn; /* Must be first */
 565         bool labels;
 566 };
 567
 568 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
 569 static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb,
 570                                    u16 zone_id, bool force)
 571 {
 572         enum ip_conntrack_info ctinfo;
 573         struct nf_conn *ct;
 574
 575         ct = nf_ct_get(skb, &ctinfo);
 576         if (!ct)
 577                 return false;
 578         if (!net_eq(net, read_pnet(&ct->ct_net)))
 579                 return false;
 580         if (nf_ct_zone(ct)->id != zone_id)
 581                 return false;
 582
 583         /* Force conntrack entry direction. */
 584         if (force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
 585                 if (nf_ct_is_confirmed(ct))
 586                         nf_ct_kill(ct);
 587
 588                 nf_conntrack_put(&ct->ct_general);
 589                 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
 590
 591                 return false;
 592         }
 593
 594         return true;
 595 }
 596
 597 /* Trim the skb to the length specified by the IP/IPv6 header,
 598  * removing any trailing lower-layer padding. This prepares the skb
 599  * for higher-layer processing that assumes skb->len excludes padding
 600  * (such as nf_ip_checksum). The caller needs to pull the skb to the
 601  * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
 602  */
 603 static int tcf_ct_skb_network_trim(struct sk_buff *skb, int family)
 604 {
 605         unsigned int len;
 606         int err;
 607
 608         switch (family) {
 609         case NFPROTO_IPV4:
 610                 len = ntohs(ip_hdr(skb)->tot_len);
 611                 break;
 612         case NFPROTO_IPV6:
 613                 len = sizeof(struct ipv6hdr)
 614                         + ntohs(ipv6_hdr(skb)->payload_len);
 615                 break;
 616         default:
 617                 len = skb->len;
 618         }
 619
 620         err = pskb_trim_rcsum(skb, len);
 621
 622         return err;
 623 }
 624
 625 static u8 tcf_ct_skb_nf_family(struct sk_buff *skb)
 626 {
 627         u8 family = NFPROTO_UNSPEC;
 628
 629         switch (skb_protocol(skb, true)) {
 630         case htons(ETH_P_IP):
 631                 family = NFPROTO_IPV4;
 632                 break;
 633         case htons(ETH_P_IPV6):
 634                 family = NFPROTO_IPV6;
 635                 break;
 636         default:
 637                 break;
 638         }
 639
 640         return family;
 641 }
 642
 643 static int tcf_ct_ipv4_is_fragment(struct sk_buff *skb, bool *frag)
 644 {
 645         unsigned int len;
 646
 647         len =  skb_network_offset(skb) + sizeof(struct iphdr);
 648         if (unlikely(skb->len < len))
 649                 return -EINVAL;
 650         if (unlikely(!pskb_may_pull(skb, len)))
 651                 return -ENOMEM;
 652
 653         *frag = ip_is_fragment(ip_hdr(skb));
 654         return 0;
 655 }
 656
 657 static int tcf_ct_ipv6_is_fragment(struct sk_buff *skb, bool *frag)
 658 {
 659         unsigned int flags = 0, len, payload_ofs = 0;
 660         unsigned short frag_off;
 661         int nexthdr;
 662
 663         len =  skb_network_offset(skb) + sizeof(struct ipv6hdr);
 664         if (unlikely(skb->len < len))
 665                 return -EINVAL;
 666         if (unlikely(!pskb_may_pull(skb, len)))
 667                 return -ENOMEM;
 668
 669         nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
 670         if (unlikely(nexthdr < 0))
 671                 return -EPROTO;
 672
 673         *frag = flags & IP6_FH_F_FRAG;
 674         return 0;
 675 }
 676
 677 static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb,
 678                                    u8 family, u16 zone, bool *defrag)
 679 {
 680         enum ip_conntrack_info ctinfo;
 681         struct qdisc_skb_cb cb;
 682         struct nf_conn *ct;
 683         int err = 0;
 684         bool frag;
 685
 686         /* Previously seen (loopback)? Ignore. */
 687         ct = nf_ct_get(skb, &ctinfo);
 688         if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
 689                 return 0;
 690
 691         if (family == NFPROTO_IPV4)
 692                 err = tcf_ct_ipv4_is_fragment(skb, &frag);
 693         else
 694                 err = tcf_ct_ipv6_is_fragment(skb, &frag);
 695         if (err || !frag)
 696                 return err;
 697
 698         skb_get(skb);
 699         cb = *qdisc_skb_cb(skb);
 700
 701         if (family == NFPROTO_IPV4) {
 702                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 703
 704                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 705                 local_bh_disable();
 706                 err = ip_defrag(net, skb, user);
 707                 local_bh_enable();
 708                 if (err && err != -EINPROGRESS)
 709                         return err;
 710
 711                 if (!err) {
 712                         *defrag = true;
 713                         cb.mru = IPCB(skb)->frag_max_size;
 714                 }
 715         } else { /* NFPROTO_IPV6 */
 716 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 717                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 718
 719                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 720                 err = nf_ct_frag6_gather(net, skb, user);
 721                 if (err && err != -EINPROGRESS)
 722                         goto out_free;
 723
 724                 if (!err) {
 725                         *defrag = true;
 726                         cb.mru = IP6CB(skb)->frag_max_size;
 727                 }
 728 #else
 729                 err = -EOPNOTSUPP;
 730                 goto out_free;
 731 #endif
 732         }
 733
 734         *qdisc_skb_cb(skb) = cb;
 735         skb_clear_hash(skb);
 736         skb->ignore_df = 1;
 737         return err;
 738
 739 out_free:
 740         kfree_skb(skb);
 741         return err;
 742 }
 743
 744 static void tcf_ct_params_free(struct rcu_head *head)
 745 {
 746         struct tcf_ct_params *params = container_of(head,
 747                                                     struct tcf_ct_params, rcu);
 748
 749         tcf_ct_flow_table_put(params);
 750
 751         if (params->tmpl)
 752                 nf_conntrack_put(&params->tmpl->ct_general);
 753         kfree(params);
 754 }
 755
 756 #if IS_ENABLED(CONFIG_NF_NAT)
 757 /* Modelled after nf_nat_ipv[46]_fn().
 758  * range is only used for new, uninitialized NAT state.
 759  * Returns either NF_ACCEPT or NF_DROP.
 760  */
 761 static int ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 762                           enum ip_conntrack_info ctinfo,
 763                           const struct nf_nat_range2 *range,
 764                           enum nf_nat_manip_type maniptype)
 765 {
 766         __be16 proto = skb_protocol(skb, true);
 767         int hooknum, err = NF_ACCEPT;
 768
 769         /* See HOOK2MANIP(). */
 770         if (maniptype == NF_NAT_MANIP_SRC)
 771                 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
 772         else
 773                 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
 774
 775         switch (ctinfo) {
 776         case IP_CT_RELATED:
 777         case IP_CT_RELATED_REPLY:
 778                 if (proto == htons(ETH_P_IP) &&
 779                     ip_hdr(skb)->protocol == IPPROTO_ICMP) {
 780                         if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
 781                                                            hooknum))
 782                                 err = NF_DROP;
 783                         goto out;
 784                 } else if (IS_ENABLED(CONFIG_IPV6) && proto == htons(ETH_P_IPV6)) {
 785                         __be16 frag_off;
 786                         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 787                         int hdrlen = ipv6_skip_exthdr(skb,
 788                                                       sizeof(struct ipv6hdr),
 789                                                       &nexthdr, &frag_off);
 790
 791                         if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
 792                                 if (!nf_nat_icmpv6_reply_translation(skb, ct,
 793                                                                      ctinfo,
 794                                                                      hooknum,
 795                                                                      hdrlen))
 796                                         err = NF_DROP;
 797                                 goto out;
 798                         }
 799                 }
 800                 /* Non-ICMP, fall thru to initialize if needed. */
 801                 fallthrough;
 802         case IP_CT_NEW:
 803                 /* Seen it before?  This can happen for loopback, retrans,
 804                  * or local packets.
 805                  */
 806                 if (!nf_nat_initialized(ct, maniptype)) {
 807                         /* Initialize according to the NAT action. */
 808                         err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
 809                                 /* Action is set up to establish a new
 810                                  * mapping.
 811                                  */
 812                                 ? nf_nat_setup_info(ct, range, maniptype)
 813                                 : nf_nat_alloc_null_binding(ct, hooknum);
 814                         if (err != NF_ACCEPT)
 815                                 goto out;
 816                 }
 817                 break;
 818
 819         case IP_CT_ESTABLISHED:
 820         case IP_CT_ESTABLISHED_REPLY:
 821                 break;
 822
 823         default:
 824                 err = NF_DROP;
 825                 goto out;
 826         }
 827
 828         err = nf_nat_packet(ct, ctinfo, hooknum, skb);
 829 out:
 830         return err;
 831 }
 832 #endif /* CONFIG_NF_NAT */
 833
 834 static void tcf_ct_act_set_mark(struct nf_conn *ct, u32 mark, u32 mask)
 835 {
 836 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 837         u32 new_mark;
 838
 839         if (!mask)
 840                 return;
 841
 842         new_mark = mark | (ct->mark & ~(mask));
 843         if (ct->mark != new_mark) {
 844                 ct->mark = new_mark;
 845                 if (nf_ct_is_confirmed(ct))
 846                         nf_conntrack_event_cache(IPCT_MARK, ct);
 847         }
 848 #endif
 849 }
 850
 851 static void tcf_ct_act_set_labels(struct nf_conn *ct,
 852                                   u32 *labels,
 853                                   u32 *labels_m)
 854 {
 855 #if IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)
 856         size_t labels_sz = sizeof_field(struct tcf_ct_params, labels);
 857
 858         if (!memchr_inv(labels_m, 0, labels_sz))
 859                 return;
 860
 861         nf_connlabels_replace(ct, labels, labels_m, 4);
 862 #endif
 863 }
 864
 865 static int tcf_ct_act_nat(struct sk_buff *skb,
 866                           struct nf_conn *ct,
 867                           enum ip_conntrack_info ctinfo,
 868                           int ct_action,
 869                           struct nf_nat_range2 *range,
 870                           bool commit)
 871 {
 872 #if IS_ENABLED(CONFIG_NF_NAT)
 873         int err;
 874         enum nf_nat_manip_type maniptype;
 875
 876         if (!(ct_action & TCA_CT_ACT_NAT))
 877                 return NF_ACCEPT;
 878
 879         /* Add NAT extension if not confirmed yet. */
 880         if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
 881                 return NF_DROP;   /* Can't NAT. */
 882
 883         if (ctinfo != IP_CT_NEW && (ct->status & IPS_NAT_MASK) &&
 884             (ctinfo != IP_CT_RELATED || commit)) {
 885                 /* NAT an established or related connection like before. */
 886                 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
 887                         /* This is the REPLY direction for a connection
 888                          * for which NAT was applied in the forward
 889                          * direction.  Do the reverse NAT.
 890                          */
 891                         maniptype = ct->status & IPS_SRC_NAT
 892                                 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
 893                 else
 894                         maniptype = ct->status & IPS_SRC_NAT
 895                                 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
 896         } else if (ct_action & TCA_CT_ACT_NAT_SRC) {
 897                 maniptype = NF_NAT_MANIP_SRC;
 898         } else if (ct_action & TCA_CT_ACT_NAT_DST) {
 899                 maniptype = NF_NAT_MANIP_DST;
 900         } else {
 901                 return NF_ACCEPT;
 902         }
 903
 904         err = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
 905         if (err == NF_ACCEPT &&
 906             ct->status & IPS_SRC_NAT && ct->status & IPS_DST_NAT) {
 907                 if (maniptype == NF_NAT_MANIP_SRC)
 908                         maniptype = NF_NAT_MANIP_DST;
 909                 else
 910                         maniptype = NF_NAT_MANIP_SRC;
 911
 912                 err = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
 913         }
 914         return err;
 915 #else
 916         return NF_ACCEPT;
 917 #endif
 918 }
 919
 920 static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
 921                       struct tcf_result *res)
 922 {
 923         struct net *net = dev_net(skb->dev);
 924         bool cached, commit, clear, force;
 925         enum ip_conntrack_info ctinfo;
 926         struct tcf_ct *c = to_ct(a);
 927         struct nf_conn *tmpl = NULL;
 928         struct nf_hook_state state;
 929         int nh_ofs, err, retval;
 930         struct tcf_ct_params *p;
 931         bool skip_add = false;
 932         bool defrag = false;
 933         struct nf_conn *ct;
 934         u8 family;
 935
 936         p = rcu_dereference_bh(c->params);
 937
 938         retval = READ_ONCE(c->tcf_action);
 939         commit = p->ct_action & TCA_CT_ACT_COMMIT;
 940         clear = p->ct_action & TCA_CT_ACT_CLEAR;
 941         force = p->ct_action & TCA_CT_ACT_FORCE;
 942         tmpl = p->tmpl;
 943
 944         tcf_lastuse_update(&c->tcf_tm);
 945
 946         if (clear) {
 947                 ct = nf_ct_get(skb, &ctinfo);
 948                 if (ct) {
 949                         nf_conntrack_put(&ct->ct_general);
 950                         nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
 951                 }
 952
 953                 goto out;
 954         }
 955
 956         family = tcf_ct_skb_nf_family(skb);
 957         if (family == NFPROTO_UNSPEC)
 958                 goto drop;
 959
 960         /* The conntrack module expects to be working at L3.
 961          * We also try to pull the IPv4/6 header to linear area
 962          */
 963         nh_ofs = skb_network_offset(skb);
 964         skb_pull_rcsum(skb, nh_ofs);
 965         err = tcf_ct_handle_fragments(net, skb, family, p->zone, &defrag);
 966         if (err == -EINPROGRESS) {
 967                 retval = TC_ACT_STOLEN;
 968                 goto out;
 969         }
 970         if (err)
 971                 goto drop;
 972
 973         err = tcf_ct_skb_network_trim(skb, family);
 974         if (err)
 975                 goto drop;
 976
 977         /* If we are recirculating packets to match on ct fields and
 978          * committing with a separate ct action, then we don't need to
 979          * actually run the packet through conntrack twice unless it's for a
 980          * different zone.
 981          */
 982         cached = tcf_ct_skb_nfct_cached(net, skb, p->zone, force);
 983         if (!cached) {
 984                 if (!commit && tcf_ct_flow_table_lookup(p, skb, family)) {
 985                         skip_add = true;
 986                         goto do_nat;
 987                 }
 988
 989                 /* Associate skb with specified zone. */
 990                 if (tmpl) {
 991                         ct = nf_ct_get(skb, &ctinfo);
 992                         if (skb_nfct(skb))
 993                                 nf_conntrack_put(skb_nfct(skb));
 994                         nf_conntrack_get(&tmpl->ct_general);
 995                         nf_ct_set(skb, tmpl, IP_CT_NEW);
 996                 }
 997
 998                 state.hook = NF_INET_PRE_ROUTING;
 999                 state.net = net;
1000                 state.pf = family;
1001                 err = nf_conntrack_in(skb, &state);
1002                 if (err != NF_ACCEPT)
1003                         goto out_push;
1004         }
1005
1006 do_nat:
1007         ct = nf_ct_get(skb, &ctinfo);
1008         if (!ct)
1009                 goto out_push;
1010         nf_ct_deliver_cached_events(ct);
1011
1012         err = tcf_ct_act_nat(skb, ct, ctinfo, p->ct_action, &p->range, commit);
1013         if (err != NF_ACCEPT)
1014                 goto drop;
1015
1016         if (commit) {
1017                 tcf_ct_act_set_mark(ct, p->mark, p->mark_mask);
1018                 tcf_ct_act_set_labels(ct, p->labels, p->labels_mask);
1019
1020                 /* This will take care of sending queued events
1021                  * even if the connection is already confirmed.
1022                  */
1023                 nf_conntrack_confirm(skb);
1024         } else if (!skip_add) {
1025                 tcf_ct_flow_table_process_conn(p->ct_ft, ct, ctinfo);
1026         }
1027
1028 out_push:
1029         skb_push_rcsum(skb, nh_ofs);
1030
1031 out:
1032         tcf_action_update_bstats(&c->common, skb);
1033         if (defrag)
1034                 qdisc_skb_cb(skb)->pkt_len = skb->len;
1035         return retval;
1036
1037 drop:
1038         tcf_action_inc_drop_qstats(&c->common);
1039         return TC_ACT_SHOT;
1040 }
1041
1042 static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = {
1043         [TCA_CT_ACTION] = { .type = NLA_U16 },
1044         [TCA_CT_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_ct)),
1045         [TCA_CT_ZONE] = { .type = NLA_U16 },
1046         [TCA_CT_MARK] = { .type = NLA_U32 },
1047         [TCA_CT_MARK_MASK] = { .type = NLA_U32 },
1048         [TCA_CT_LABELS] = { .type = NLA_BINARY,
1049                             .len = 128 / BITS_PER_BYTE },
1050         [TCA_CT_LABELS_MASK] = { .type = NLA_BINARY,
1051                                  .len = 128 / BITS_PER_BYTE },
1052         [TCA_CT_NAT_IPV4_MIN] = { .type = NLA_U32 },
1053         [TCA_CT_NAT_IPV4_MAX] = { .type = NLA_U32 },
1054         [TCA_CT_NAT_IPV6_MIN] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
1055         [TCA_CT_NAT_IPV6_MAX] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
1056         [TCA_CT_NAT_PORT_MIN] = { .type = NLA_U16 },
1057         [TCA_CT_NAT_PORT_MAX] = { .type = NLA_U16 },
1058 };
1059
1060 static int tcf_ct_fill_params_nat(struct tcf_ct_params *p,
1061                                   struct tc_ct *parm,
1062                                   struct nlattr **tb,
1063                                   struct netlink_ext_ack *extack)
1064 {
1065         struct nf_nat_range2 *range;
1066
1067         if (!(p->ct_action & TCA_CT_ACT_NAT))
1068                 return 0;
1069
1070         if (!IS_ENABLED(CONFIG_NF_NAT)) {
1071                 NL_SET_ERR_MSG_MOD(extack, "Netfilter nat isn't enabled in kernel");
1072                 return -EOPNOTSUPP;
1073         }
1074
1075         if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST)))
1076                 return 0;
1077
1078         if ((p->ct_action & TCA_CT_ACT_NAT_SRC) &&
1079             (p->ct_action & TCA_CT_ACT_NAT_DST)) {
1080                 NL_SET_ERR_MSG_MOD(extack, "dnat and snat can't be enabled at the same time");
1081                 return -EOPNOTSUPP;
1082         }
1083
1084         range = &p->range;
1085         if (tb[TCA_CT_NAT_IPV4_MIN]) {
1086                 struct nlattr *max_attr = tb[TCA_CT_NAT_IPV4_MAX];
1087
1088                 p->ipv4_range = true;
1089                 range->flags |= NF_NAT_RANGE_MAP_IPS;
1090                 range->min_addr.ip =
1091                         nla_get_in_addr(tb[TCA_CT_NAT_IPV4_MIN]);
1092
1093                 range->max_addr.ip = max_attr ?
1094                                      nla_get_in_addr(max_attr) :
1095                                      range->min_addr.ip;
1096         } else if (tb[TCA_CT_NAT_IPV6_MIN]) {
1097                 struct nlattr *max_attr = tb[TCA_CT_NAT_IPV6_MAX];
1098
1099                 p->ipv4_range = false;
1100                 range->flags |= NF_NAT_RANGE_MAP_IPS;
1101                 range->min_addr.in6 =
1102                         nla_get_in6_addr(tb[TCA_CT_NAT_IPV6_MIN]);
1103
1104                 range->max_addr.in6 = max_attr ?
1105                                       nla_get_in6_addr(max_attr) :
1106                                       range->min_addr.in6;
1107         }
1108
1109         if (tb[TCA_CT_NAT_PORT_MIN]) {
1110                 range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1111                 range->min_proto.all = nla_get_be16(tb[TCA_CT_NAT_PORT_MIN]);
1112
1113                 range->max_proto.all = tb[TCA_CT_NAT_PORT_MAX] ?
1114                                        nla_get_be16(tb[TCA_CT_NAT_PORT_MAX]) :
1115                                        range->min_proto.all;
1116         }
1117
1118         return 0;
1119 }
1120
1121 static void tcf_ct_set_key_val(struct nlattr **tb,
1122                                void *val, int val_type,
1123                                void *mask, int mask_type,
1124                                int len)
1125 {
1126         if (!tb[val_type])
1127                 return;
1128         nla_memcpy(val, tb[val_type], len);
1129
1130         if (!mask)
1131                 return;
1132
1133         if (mask_type == TCA_CT_UNSPEC || !tb[mask_type])
1134                 memset(mask, 0xff, len);
1135         else
1136                 nla_memcpy(mask, tb[mask_type], len);
1137 }
1138
1139 static int tcf_ct_fill_params(struct net *net,
1140                               struct tcf_ct_params *p,
1141                               struct tc_ct *parm,
1142                               struct nlattr **tb,
1143                               struct netlink_ext_ack *extack)
1144 {
1145         struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
1146         struct nf_conntrack_zone zone;
1147         struct nf_conn *tmpl;
1148         int err;
1149
1150         p->zone = NF_CT_DEFAULT_ZONE_ID;
1151
1152         tcf_ct_set_key_val(tb,
1153                            &p->ct_action, TCA_CT_ACTION,
1154                            NULL, TCA_CT_UNSPEC,
1155                            sizeof(p->ct_action));
1156
1157         if (p->ct_action & TCA_CT_ACT_CLEAR)
1158                 return 0;
1159
1160         err = tcf_ct_fill_params_nat(p, parm, tb, extack);
1161         if (err)
1162                 return err;
1163
1164         if (tb[TCA_CT_MARK]) {
1165                 if (!IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)) {
1166                         NL_SET_ERR_MSG_MOD(extack, "Conntrack mark isn't enabled.");
1167                         return -EOPNOTSUPP;
1168                 }
1169                 tcf_ct_set_key_val(tb,
1170                                    &p->mark, TCA_CT_MARK,
1171                                    &p->mark_mask, TCA_CT_MARK_MASK,
1172                                    sizeof(p->mark));
1173         }
1174
1175         if (tb[TCA_CT_LABELS]) {
1176                 if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)) {
1177                         NL_SET_ERR_MSG_MOD(extack, "Conntrack labels isn't enabled.");
1178                         return -EOPNOTSUPP;
1179                 }
1180
1181                 if (!tn->labels) {
1182                         NL_SET_ERR_MSG_MOD(extack, "Failed to set connlabel length");
1183                         return -EOPNOTSUPP;
1184                 }
1185                 tcf_ct_set_key_val(tb,
1186                                    p->labels, TCA_CT_LABELS,
1187                                    p->labels_mask, TCA_CT_LABELS_MASK,
1188                                    sizeof(p->labels));
1189         }
1190
1191         if (tb[TCA_CT_ZONE]) {
1192                 if (!IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)) {
1193                         NL_SET_ERR_MSG_MOD(extack, "Conntrack zones isn't enabled.");
1194                         return -EOPNOTSUPP;
1195                 }
1196
1197                 tcf_ct_set_key_val(tb,
1198                                    &p->zone, TCA_CT_ZONE,
1199                                    NULL, TCA_CT_UNSPEC,
1200                                    sizeof(p->zone));
1201         }
1202
1203         if (p->zone == NF_CT_DEFAULT_ZONE_ID)
1204                 return 0;
1205
1206         nf_ct_zone_init(&zone, p->zone, NF_CT_DEFAULT_ZONE_DIR, 0);
1207         tmpl = nf_ct_tmpl_alloc(net, &zone, GFP_KERNEL);
1208         if (!tmpl) {
1209                 NL_SET_ERR_MSG_MOD(extack, "Failed to allocate conntrack template");
1210                 return -ENOMEM;
1211         }
1212         __set_bit(IPS_CONFIRMED_BIT, &tmpl->status);
1213         nf_conntrack_get(&tmpl->ct_general);
1214         p->tmpl = tmpl;
1215
1216         return 0;
1217 }
1218
1219 static int tcf_ct_init(struct net *net, struct nlattr *nla,
1220                        struct nlattr *est, struct tc_action **a,
1221                        int replace, int bind, bool rtnl_held,
1222                        struct tcf_proto *tp, u32 flags,
1223                        struct netlink_ext_ack *extack)
1224 {
1225         struct tc_action_net *tn = net_generic(net, ct_net_id);
1226         struct tcf_ct_params *params = NULL;
1227         struct nlattr *tb[TCA_CT_MAX + 1];
1228         struct tcf_chain *goto_ch = NULL;
1229         struct tc_ct *parm;
1230         struct tcf_ct *c;
1231         int err, res = 0;
1232         u32 index;
1233
1234         if (!nla) {
1235                 NL_SET_ERR_MSG_MOD(extack, "Ct requires attributes to be passed");
1236                 return -EINVAL;
1237         }
1238
1239         err = nla_parse_nested(tb, TCA_CT_MAX, nla, ct_policy, extack);
1240         if (err < 0)
1241                 return err;
1242
1243         if (!tb[TCA_CT_PARMS]) {
1244                 NL_SET_ERR_MSG_MOD(extack, "Missing required ct parameters");
1245                 return -EINVAL;
1246         }
1247         parm = nla_data(tb[TCA_CT_PARMS]);
1248         index = parm->index;
1249         err = tcf_idr_check_alloc(tn, &index, a, bind);
1250         if (err < 0)
1251                 return err;
1252
1253         if (!err) {
1254                 err = tcf_idr_create_from_flags(tn, index, est, a,
1255                                                 &act_ct_ops, bind, flags);
1256                 if (err) {
1257                         tcf_idr_cleanup(tn, index);
1258                         return err;
1259                 }
1260                 res = ACT_P_CREATED;
1261         } else {
1262                 if (bind)
1263                         return 0;
1264
1265                 if (!replace) {
1266                         tcf_idr_release(*a, bind);
1267                         return -EEXIST;
1268                 }
1269         }
1270         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
1271         if (err < 0)
1272                 goto cleanup;
1273
1274         c = to_ct(*a);
1275
1276         params = kzalloc(sizeof(*params), GFP_KERNEL);
1277         if (unlikely(!params)) {
1278                 err = -ENOMEM;
1279                 goto cleanup;
1280         }
1281
1282         err = tcf_ct_fill_params(net, params, parm, tb, extack);
1283         if (err)
1284                 goto cleanup;
1285
1286         err = tcf_ct_flow_table_get(params);
1287         if (err)
1288                 goto cleanup;
1289
1290         spin_lock_bh(&c->tcf_lock);
1291         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
1292         params = rcu_replace_pointer(c->params, params,
1293                                      lockdep_is_held(&c->tcf_lock));
1294         spin_unlock_bh(&c->tcf_lock);
1295
1296         if (goto_ch)
1297                 tcf_chain_put_by_act(goto_ch);
1298         if (params)
1299                 call_rcu(&params->rcu, tcf_ct_params_free);
1300
1301         return res;
1302
1303 cleanup:
1304         if (goto_ch)
1305                 tcf_chain_put_by_act(goto_ch);
1306         kfree(params);
1307         tcf_idr_release(*a, bind);
1308         return err;
1309 }
1310
1311 static void tcf_ct_cleanup(struct tc_action *a)
1312 {
1313         struct tcf_ct_params *params;
1314         struct tcf_ct *c = to_ct(a);
1315
1316         params = rcu_dereference_protected(c->params, 1);
1317         if (params)
1318                 call_rcu(&params->rcu, tcf_ct_params_free);
1319 }
1320
1321 static int tcf_ct_dump_key_val(struct sk_buff *skb,
1322                                void *val, int val_type,
1323                                void *mask, int mask_type,
1324                                int len)
1325 {
1326         int err;
1327
1328         if (mask && !memchr_inv(mask, 0, len))
1329                 return 0;
1330
1331         err = nla_put(skb, val_type, len, val);
1332         if (err)
1333                 return err;
1334
1335         if (mask_type != TCA_CT_UNSPEC) {
1336                 err = nla_put(skb, mask_type, len, mask);
1337                 if (err)
1338                         return err;
1339         }
1340
1341         return 0;
1342 }
1343
1344 static int tcf_ct_dump_nat(struct sk_buff *skb, struct tcf_ct_params *p)
1345 {
1346         struct nf_nat_range2 *range = &p->range;
1347
1348         if (!(p->ct_action & TCA_CT_ACT_NAT))
1349                 return 0;
1350
1351         if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST)))
1352                 return 0;
1353
1354         if (range->flags & NF_NAT_RANGE_MAP_IPS) {
1355                 if (p->ipv4_range) {
1356                         if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MIN,
1357                                             range->min_addr.ip))
1358                                 return -1;
1359                         if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MAX,
1360                                             range->max_addr.ip))
1361                                 return -1;
1362                 } else {
1363                         if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MIN,
1364                                              &range->min_addr.in6))
1365                                 return -1;
1366                         if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MAX,
1367                                              &range->max_addr.in6))
1368                                 return -1;
1369                 }
1370         }
1371
1372         if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
1373                 if (nla_put_be16(skb, TCA_CT_NAT_PORT_MIN,
1374                                  range->min_proto.all))
1375                         return -1;
1376                 if (nla_put_be16(skb, TCA_CT_NAT_PORT_MAX,
1377                                  range->max_proto.all))
1378                         return -1;
1379         }
1380
1381         return 0;
1382 }
1383
1384 static inline int tcf_ct_dump(struct sk_buff *skb, struct tc_action *a,
1385                               int bind, int ref)
1386 {
1387         unsigned char *b = skb_tail_pointer(skb);
1388         struct tcf_ct *c = to_ct(a);
1389         struct tcf_ct_params *p;
1390
1391         struct tc_ct opt = {
1392                 .index   = c->tcf_index,
1393                 .refcnt  = refcount_read(&c->tcf_refcnt) - ref,
1394                 .bindcnt = atomic_read(&c->tcf_bindcnt) - bind,
1395         };
1396         struct tcf_t t;
1397
1398         spin_lock_bh(&c->tcf_lock);
1399         p = rcu_dereference_protected(c->params,
1400                                       lockdep_is_held(&c->tcf_lock));
1401         opt.action = c->tcf_action;
1402
1403         if (tcf_ct_dump_key_val(skb,
1404                                 &p->ct_action, TCA_CT_ACTION,
1405                                 NULL, TCA_CT_UNSPEC,
1406                                 sizeof(p->ct_action)))
1407                 goto nla_put_failure;
1408
1409         if (p->ct_action & TCA_CT_ACT_CLEAR)
1410                 goto skip_dump;
1411
1412         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1413             tcf_ct_dump_key_val(skb,
1414                                 &p->mark, TCA_CT_MARK,
1415                                 &p->mark_mask, TCA_CT_MARK_MASK,
1416                                 sizeof(p->mark)))
1417                 goto nla_put_failure;
1418
1419         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1420             tcf_ct_dump_key_val(skb,
1421                                 p->labels, TCA_CT_LABELS,
1422                                 p->labels_mask, TCA_CT_LABELS_MASK,
1423                                 sizeof(p->labels)))
1424                 goto nla_put_failure;
1425
1426         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1427             tcf_ct_dump_key_val(skb,
1428                                 &p->zone, TCA_CT_ZONE,
1429                                 NULL, TCA_CT_UNSPEC,
1430                                 sizeof(p->zone)))
1431                 goto nla_put_failure;
1432
1433         if (tcf_ct_dump_nat(skb, p))
1434                 goto nla_put_failure;
1435
1436 skip_dump:
1437         if (nla_put(skb, TCA_CT_PARMS, sizeof(opt), &opt))
1438                 goto nla_put_failure;
1439
1440         tcf_tm_dump(&t, &c->tcf_tm);
1441         if (nla_put_64bit(skb, TCA_CT_TM, sizeof(t), &t, TCA_CT_PAD))
1442                 goto nla_put_failure;
1443         spin_unlock_bh(&c->tcf_lock);
1444
1445         return skb->len;
1446 nla_put_failure:
1447         spin_unlock_bh(&c->tcf_lock);
1448         nlmsg_trim(skb, b);
1449         return -1;
1450 }
1451
1452 static int tcf_ct_walker(struct net *net, struct sk_buff *skb,
1453                          struct netlink_callback *cb, int type,
1454                          const struct tc_action_ops *ops,
1455                          struct netlink_ext_ack *extack)
1456 {
1457         struct tc_action_net *tn = net_generic(net, ct_net_id);
1458
1459         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
1460 }
1461
1462 static int tcf_ct_search(struct net *net, struct tc_action **a, u32 index)
1463 {
1464         struct tc_action_net *tn = net_generic(net, ct_net_id);
1465
1466         return tcf_idr_search(tn, a, index);
1467 }
1468
1469 static void tcf_stats_update(struct tc_action *a, u64 bytes, u64 packets,
1470                              u64 drops, u64 lastuse, bool hw)
1471 {
1472         struct tcf_ct *c = to_ct(a);
1473
1474         tcf_action_update_stats(a, bytes, packets, drops, hw);
1475         c->tcf_tm.lastuse = max_t(u64, c->tcf_tm.lastuse, lastuse);
1476 }
1477
1478 static struct tc_action_ops act_ct_ops = {
1479         .kind           =       "ct",
1480         .id             =       TCA_ID_CT,
1481         .owner          =       THIS_MODULE,
1482         .act            =       tcf_ct_act,
1483         .dump           =       tcf_ct_dump,
1484         .init           =       tcf_ct_init,
1485         .cleanup        =       tcf_ct_cleanup,
1486         .walk           =       tcf_ct_walker,
1487         .lookup         =       tcf_ct_search,
1488         .stats_update   =       tcf_stats_update,
1489         .size           =       sizeof(struct tcf_ct),
1490 };
1491
1492 static __net_init int ct_init_net(struct net *net)
1493 {
1494         unsigned int n_bits = sizeof_field(struct tcf_ct_params, labels) * 8;
1495         struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
1496
1497         if (nf_connlabels_get(net, n_bits - 1)) {
1498                 tn->labels = false;
1499                 pr_err("act_ct: Failed to set connlabels length");
1500         } else {
1501                 tn->labels = true;
1502         }
1503
1504         return tc_action_net_init(net, &tn->tn, &act_ct_ops);
1505 }
1506
1507 static void __net_exit ct_exit_net(struct list_head *net_list)
1508 {
1509         struct net *net;
1510
1511         rtnl_lock();
1512         list_for_each_entry(net, net_list, exit_list) {
1513                 struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
1514
1515                 if (tn->labels)
1516                         nf_connlabels_put(net);
1517         }
1518         rtnl_unlock();
1519
1520         tc_action_net_exit(net_list, ct_net_id);
1521 }
1522
1523 static struct pernet_operations ct_net_ops = {
1524         .init = ct_init_net,
1525         .exit_batch = ct_exit_net,
1526         .id   = &ct_net_id,
1527         .size = sizeof(struct tc_ct_action_net),
1528 };
1529
1530 static int __init ct_init_module(void)
1531 {
1532         int err;
1533
1534         act_ct_wq = alloc_ordered_workqueue("act_ct_workqueue", 0);
1535         if (!act_ct_wq)
1536                 return -ENOMEM;
1537
1538         err = tcf_ct_flow_tables_init();
1539         if (err)
1540                 goto err_tbl_init;
1541
1542         err = tcf_register_action(&act_ct_ops, &ct_net_ops);
1543         if (err)
1544                 goto err_register;
1545
1546         static_branch_inc(&tcf_frag_xmit_count);
1547
1548         return 0;
1549
1550 err_register:
1551         tcf_ct_flow_tables_uninit();
1552 err_tbl_init:
1553         destroy_workqueue(act_ct_wq);
1554         return err;
1555 }
1556
1557 static void __exit ct_cleanup_module(void)
1558 {
1559         static_branch_dec(&tcf_frag_xmit_count);
1560         tcf_unregister_action(&act_ct_ops, &ct_net_ops);
1561         tcf_ct_flow_tables_uninit();
1562         destroy_workqueue(act_ct_wq);
1563 }
1564
1565 module_init(ct_init_module);
1566 module_exit(ct_cleanup_module);
1567 MODULE_AUTHOR("Paul Blakey <paulb@mellanox.com>");
1568 MODULE_AUTHOR("Yossi Kuperman <yossiku@mellanox.com>");
1569 MODULE_AUTHOR("Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>");
1570 MODULE_DESCRIPTION("Connection tracking action");
1571 MODULE_LICENSE("GPL v2");