net/openvswitch/conntrack.c

   1 /*
   2  * Copyright (c) 2015 Nicira, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General Public
   6  * License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/openvswitch.h>
  16 #include <net/ip.h>
  17 #include <net/netfilter/nf_conntrack_core.h>
  18 #include <net/netfilter/nf_conntrack_helper.h>
  19 #include <net/netfilter/nf_conntrack_labels.h>
  20 #include <net/netfilter/nf_conntrack_zones.h>
  21 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  22
  23 #include "datapath.h"
  24 #include "conntrack.h"
  25 #include "flow.h"
  26 #include "flow_netlink.h"
  27
  28 struct ovs_ct_len_tbl {
  29         size_t maxlen;
  30         size_t minlen;
  31 };
  32
  33 /* Metadata mark for masked write to conntrack mark */
  34 struct md_mark {
  35         u32 value;
  36         u32 mask;
  37 };
  38
  39 /* Metadata label for masked write to conntrack label. */
  40 struct md_labels {
  41         struct ovs_key_ct_labels value;
  42         struct ovs_key_ct_labels mask;
  43 };
  44
  45 /* Conntrack action context for execution. */
  46 struct ovs_conntrack_info {
  47         struct nf_conntrack_helper *helper;
  48         struct nf_conntrack_zone zone;
  49         struct nf_conn *ct;
  50         u8 commit : 1;
  51         u16 family;
  52         struct md_mark mark;
  53         struct md_labels labels;
  54 };
  55
  56 static u16 key_to_nfproto(const struct sw_flow_key *key)
  57 {
  58         switch (ntohs(key->eth.type)) {
  59         case ETH_P_IP:
  60                 return NFPROTO_IPV4;
  61         case ETH_P_IPV6:
  62                 return NFPROTO_IPV6;
  63         default:
  64                 return NFPROTO_UNSPEC;
  65         }
  66 }
  67
  68 /* Map SKB connection state into the values used by flow definition. */
  69 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
  70 {
  71         u8 ct_state = OVS_CS_F_TRACKED;
  72
  73         switch (ctinfo) {
  74         case IP_CT_ESTABLISHED_REPLY:
  75         case IP_CT_RELATED_REPLY:
  76         case IP_CT_NEW_REPLY:
  77                 ct_state |= OVS_CS_F_REPLY_DIR;
  78                 break;
  79         default:
  80                 break;
  81         }
  82
  83         switch (ctinfo) {
  84         case IP_CT_ESTABLISHED:
  85         case IP_CT_ESTABLISHED_REPLY:
  86                 ct_state |= OVS_CS_F_ESTABLISHED;
  87                 break;
  88         case IP_CT_RELATED:
  89         case IP_CT_RELATED_REPLY:
  90                 ct_state |= OVS_CS_F_RELATED;
  91                 break;
  92         case IP_CT_NEW:
  93         case IP_CT_NEW_REPLY:
  94                 ct_state |= OVS_CS_F_NEW;
  95                 break;
  96         default:
  97                 break;
  98         }
  99
 100         return ct_state;
 101 }
 102
 103 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
 104 {
 105 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 106         return ct ? ct->mark : 0;
 107 #else
 108         return 0;
 109 #endif
 110 }
 111
 112 static void ovs_ct_get_labels(const struct nf_conn *ct,
 113                               struct ovs_key_ct_labels *labels)
 114 {
 115         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
 116
 117         if (cl) {
 118                 size_t len = cl->words * sizeof(long);
 119
 120                 if (len > OVS_CT_LABELS_LEN)
 121                         len = OVS_CT_LABELS_LEN;
 122                 else if (len < OVS_CT_LABELS_LEN)
 123                         memset(labels, 0, OVS_CT_LABELS_LEN);
 124                 memcpy(labels, cl->bits, len);
 125         } else {
 126                 memset(labels, 0, OVS_CT_LABELS_LEN);
 127         }
 128 }
 129
 130 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
 131                                 const struct nf_conntrack_zone *zone,
 132                                 const struct nf_conn *ct)
 133 {
 134         key->ct.state = state;
 135         key->ct.zone = zone->id;
 136         key->ct.mark = ovs_ct_get_mark(ct);
 137         ovs_ct_get_labels(ct, &key->ct.labels);
 138 }
 139
 140 /* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
 141  * previously sent the packet to conntrack via the ct action.
 142  */
 143 static void ovs_ct_update_key(const struct sk_buff *skb,
 144                               struct sw_flow_key *key, bool post_ct)
 145 {
 146         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 147         enum ip_conntrack_info ctinfo;
 148         struct nf_conn *ct;
 149         u8 state = 0;
 150
 151         ct = nf_ct_get(skb, &ctinfo);
 152         if (ct) {
 153                 state = ovs_ct_get_state(ctinfo);
 154                 if (!nf_ct_is_confirmed(ct))
 155                         state |= OVS_CS_F_NEW;
 156                 if (ct->master)
 157                         state |= OVS_CS_F_RELATED;
 158                 zone = nf_ct_zone(ct);
 159         } else if (post_ct) {
 160                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 161         }
 162         __ovs_ct_update_key(key, state, zone, ct);
 163 }
 164
 165 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 166 {
 167         ovs_ct_update_key(skb, key, false);
 168 }
 169
 170 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 171 {
 172         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 173                 return -EMSGSIZE;
 174
 175         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 176             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 177                 return -EMSGSIZE;
 178
 179         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 180             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 181                 return -EMSGSIZE;
 182
 183         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 184             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
 185                     &key->ct.labels))
 186                 return -EMSGSIZE;
 187
 188         return 0;
 189 }
 190
 191 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 192                            u32 ct_mark, u32 mask)
 193 {
 194 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 195         enum ip_conntrack_info ctinfo;
 196         struct nf_conn *ct;
 197         u32 new_mark;
 198
 199
 200         /* The connection could be invalid, in which case set_mark is no-op. */
 201         ct = nf_ct_get(skb, &ctinfo);
 202         if (!ct)
 203                 return 0;
 204
 205         new_mark = ct_mark | (ct->mark & ~(mask));
 206         if (ct->mark != new_mark) {
 207                 ct->mark = new_mark;
 208                 nf_conntrack_event_cache(IPCT_MARK, ct);
 209                 key->ct.mark = new_mark;
 210         }
 211
 212         return 0;
 213 #else
 214         return -ENOTSUPP;
 215 #endif
 216 }
 217
 218 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
 219                              const struct ovs_key_ct_labels *labels,
 220                              const struct ovs_key_ct_labels *mask)
 221 {
 222         enum ip_conntrack_info ctinfo;
 223         struct nf_conn_labels *cl;
 224         struct nf_conn *ct;
 225         int err;
 226
 227         /* The connection could be invalid, in which case set_label is no-op.*/
 228         ct = nf_ct_get(skb, &ctinfo);
 229         if (!ct)
 230                 return 0;
 231
 232         cl = nf_ct_labels_find(ct);
 233         if (!cl) {
 234                 nf_ct_labels_ext_add(ct);
 235                 cl = nf_ct_labels_find(ct);
 236         }
 237         if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
 238                 return -ENOSPC;
 239
 240         err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
 241                                     OVS_CT_LABELS_LEN / sizeof(u32));
 242         if (err)
 243                 return err;
 244
 245         ovs_ct_get_labels(ct, &key->ct.labels);
 246         return 0;
 247 }
 248
 249 /* 'skb' should already be pulled to nh_ofs. */
 250 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 251 {
 252         const struct nf_conntrack_helper *helper;
 253         const struct nf_conn_help *help;
 254         enum ip_conntrack_info ctinfo;
 255         unsigned int protoff;
 256         struct nf_conn *ct;
 257
 258         ct = nf_ct_get(skb, &ctinfo);
 259         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 260                 return NF_ACCEPT;
 261
 262         help = nfct_help(ct);
 263         if (!help)
 264                 return NF_ACCEPT;
 265
 266         helper = rcu_dereference(help->helper);
 267         if (!helper)
 268                 return NF_ACCEPT;
 269
 270         switch (proto) {
 271         case NFPROTO_IPV4:
 272                 protoff = ip_hdrlen(skb);
 273                 break;
 274         case NFPROTO_IPV6: {
 275                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 276                 __be16 frag_off;
 277                 int ofs;
 278
 279                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 280                                        &frag_off);
 281                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 282                         pr_debug("proto header not found\n");
 283                         return NF_ACCEPT;
 284                 }
 285                 protoff = ofs;
 286                 break;
 287         }
 288         default:
 289                 WARN_ONCE(1, "helper invoked on non-IP family!");
 290                 return NF_DROP;
 291         }
 292
 293         return helper->help(skb, protoff, ct, ctinfo);
 294 }
 295
 296 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 297  * value if 'skb' is freed.
 298  */
 299 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 300                             u16 zone, struct sk_buff *skb)
 301 {
 302         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 303
 304         if (key->eth.type == htons(ETH_P_IP)) {
 305                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 306                 int err;
 307
 308                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 309                 err = ip_defrag(skb, user);
 310                 if (err)
 311                         return err;
 312
 313                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 314 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 315         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 316                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 317                 struct sk_buff *reasm;
 318
 319                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 320                 reasm = nf_ct_frag6_gather(skb, user);
 321                 if (!reasm)
 322                         return -EINPROGRESS;
 323
 324                 if (skb == reasm) {
 325                         kfree_skb(skb);
 326                         return -EINVAL;
 327                 }
 328
 329                 /* Don't free 'skb' even though it is one of the original
 330                  * fragments, as we're going to morph it into the head.
 331                  */
 332                 skb_get(skb);
 333                 nf_ct_frag6_consume_orig(reasm);
 334
 335                 key->ip.proto = ipv6_hdr(reasm)->nexthdr;
 336                 skb_morph(skb, reasm);
 337                 skb->next = reasm->next;
 338                 consume_skb(reasm);
 339                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 340 #endif
 341         } else {
 342                 kfree_skb(skb);
 343                 return -EPFNOSUPPORT;
 344         }
 345
 346         key->ip.frag = OVS_FRAG_TYPE_NONE;
 347         skb_clear_hash(skb);
 348         skb->ignore_df = 1;
 349         *OVS_CB(skb) = ovs_cb;
 350
 351         return 0;
 352 }
 353
 354 static struct nf_conntrack_expect *
 355 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 356                    u16 proto, const struct sk_buff *skb)
 357 {
 358         struct nf_conntrack_tuple tuple;
 359
 360         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, &tuple))
 361                 return NULL;
 362         return __nf_ct_expect_find(net, zone, &tuple);
 363 }
 364
 365 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
 366 static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
 367                             const struct ovs_conntrack_info *info)
 368 {
 369         enum ip_conntrack_info ctinfo;
 370         struct nf_conn *ct;
 371
 372         ct = nf_ct_get(skb, &ctinfo);
 373         if (!ct)
 374                 return false;
 375         if (!net_eq(net, read_pnet(&ct->ct_net)))
 376                 return false;
 377         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 378                 return false;
 379         if (info->helper) {
 380                 struct nf_conn_help *help;
 381
 382                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 383                 if (help && rcu_access_pointer(help->helper) != info->helper)
 384                         return false;
 385         }
 386
 387         return true;
 388 }
 389
 390 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 391                            const struct ovs_conntrack_info *info,
 392                            struct sk_buff *skb)
 393 {
 394         /* If we are recirculating packets to match on conntrack fields and
 395          * committing with a separate conntrack action,  then we don't need to
 396          * actually run the packet through conntrack twice unless it's for a
 397          * different zone.
 398          */
 399         if (!skb_nfct_cached(net, skb, info)) {
 400                 struct nf_conn *tmpl = info->ct;
 401
 402                 /* Associate skb with specified zone. */
 403                 if (tmpl) {
 404                         if (skb->nfct)
 405                                 nf_conntrack_put(skb->nfct);
 406                         nf_conntrack_get(&tmpl->ct_general);
 407                         skb->nfct = &tmpl->ct_general;
 408                         skb->nfctinfo = IP_CT_NEW;
 409                 }
 410
 411                 if (nf_conntrack_in(net, info->family, NF_INET_PRE_ROUTING,
 412                                     skb) != NF_ACCEPT)
 413                         return -ENOENT;
 414
 415                 if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 416                         WARN_ONCE(1, "helper rejected packet");
 417                         return -EINVAL;
 418                 }
 419         }
 420
 421         ovs_ct_update_key(skb, key, true);
 422
 423         return 0;
 424 }
 425
 426 /* Lookup connection and read fields into key. */
 427 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 428                          const struct ovs_conntrack_info *info,
 429                          struct sk_buff *skb)
 430 {
 431         struct nf_conntrack_expect *exp;
 432
 433         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 434         if (exp) {
 435                 u8 state;
 436
 437                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 438                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 439         } else {
 440                 int err;
 441
 442                 err = __ovs_ct_lookup(net, key, info, skb);
 443                 if (err)
 444                         return err;
 445         }
 446
 447         return 0;
 448 }
 449
 450 /* Lookup connection and confirm if unconfirmed. */
 451 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
 452                          const struct ovs_conntrack_info *info,
 453                          struct sk_buff *skb)
 454 {
 455         u8 state;
 456         int err;
 457
 458         state = key->ct.state;
 459         if (key->ct.zone == info->zone.id &&
 460             ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
 461                 /* Previous lookup has shown that this connection is already
 462                  * tracked and committed. Skip committing.
 463                  */
 464                 return 0;
 465         }
 466
 467         err = __ovs_ct_lookup(net, key, info, skb);
 468         if (err)
 469                 return err;
 470         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
 471                 return -EINVAL;
 472
 473         return 0;
 474 }
 475
 476 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
 477 {
 478         size_t i;
 479
 480         for (i = 0; i < sizeof(*labels); i++)
 481                 if (labels->ct_labels[i])
 482                         return true;
 483
 484         return false;
 485 }
 486
 487 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 488  * value if 'skb' is freed.
 489  */
 490 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 491                    struct sw_flow_key *key,
 492                    const struct ovs_conntrack_info *info)
 493 {
 494         int nh_ofs;
 495         int err;
 496
 497         /* The conntrack module expects to be working at L3. */
 498         nh_ofs = skb_network_offset(skb);
 499         skb_pull(skb, nh_ofs);
 500
 501         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 502                 err = handle_fragments(net, key, info->zone.id, skb);
 503                 if (err)
 504                         return err;
 505         }
 506
 507         if (info->commit)
 508                 err = ovs_ct_commit(net, key, info, skb);
 509         else
 510                 err = ovs_ct_lookup(net, key, info, skb);
 511         if (err)
 512                 goto err;
 513
 514         if (info->mark.mask) {
 515                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 516                                       info->mark.mask);
 517                 if (err)
 518                         goto err;
 519         }
 520         if (labels_nonzero(&info->labels.mask))
 521                 err = ovs_ct_set_labels(skb, key, &info->labels.value,
 522                                         &info->labels.mask);
 523 err:
 524         skb_push(skb, nh_ofs);
 525         if (err)
 526                 kfree_skb(skb);
 527         return err;
 528 }
 529
 530 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 531                              const struct sw_flow_key *key, bool log)
 532 {
 533         struct nf_conntrack_helper *helper;
 534         struct nf_conn_help *help;
 535
 536         helper = nf_conntrack_helper_try_module_get(name, info->family,
 537                                                     key->ip.proto);
 538         if (!helper) {
 539                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 540                 return -EINVAL;
 541         }
 542
 543         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 544         if (!help) {
 545                 module_put(helper->me);
 546                 return -ENOMEM;
 547         }
 548
 549         rcu_assign_pointer(help->helper, helper);
 550         info->helper = helper;
 551         return 0;
 552 }
 553
 554 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
 555         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
 556         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
 557                                     .maxlen = sizeof(u16) },
 558         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
 559                                     .maxlen = sizeof(struct md_mark) },
 560         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
 561                                     .maxlen = sizeof(struct md_labels) },
 562         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
 563                                     .maxlen = NF_CT_HELPER_NAME_LEN }
 564 };
 565
 566 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
 567                     const char **helper, bool log)
 568 {
 569         struct nlattr *a;
 570         int rem;
 571
 572         nla_for_each_nested(a, attr, rem) {
 573                 int type = nla_type(a);
 574                 int maxlen = ovs_ct_attr_lens[type].maxlen;
 575                 int minlen = ovs_ct_attr_lens[type].minlen;
 576
 577                 if (type > OVS_CT_ATTR_MAX) {
 578                         OVS_NLERR(log,
 579                                   "Unknown conntrack attr (type=%d, max=%d)",
 580                                   type, OVS_CT_ATTR_MAX);
 581                         return -EINVAL;
 582                 }
 583                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
 584                         OVS_NLERR(log,
 585                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
 586                                   type, nla_len(a), maxlen);
 587                         return -EINVAL;
 588                 }
 589
 590                 switch (type) {
 591                 case OVS_CT_ATTR_COMMIT:
 592                         info->commit = true;
 593                         break;
 594 #ifdef CONFIG_NF_CONNTRACK_ZONES
 595                 case OVS_CT_ATTR_ZONE:
 596                         info->zone.id = nla_get_u16(a);
 597                         break;
 598 #endif
 599 #ifdef CONFIG_NF_CONNTRACK_MARK
 600                 case OVS_CT_ATTR_MARK: {
 601                         struct md_mark *mark = nla_data(a);
 602
 603                         if (!mark->mask) {
 604                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
 605                                 return -EINVAL;
 606                         }
 607                         info->mark = *mark;
 608                         break;
 609                 }
 610 #endif
 611 #ifdef CONFIG_NF_CONNTRACK_LABELS
 612                 case OVS_CT_ATTR_LABELS: {
 613                         struct md_labels *labels = nla_data(a);
 614
 615                         if (!labels_nonzero(&labels->mask)) {
 616                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
 617                                 return -EINVAL;
 618                         }
 619                         info->labels = *labels;
 620                         break;
 621                 }
 622 #endif
 623                 case OVS_CT_ATTR_HELPER:
 624                         *helper = nla_data(a);
 625                         if (!memchr(*helper, '\0', nla_len(a))) {
 626                                 OVS_NLERR(log, "Invalid conntrack helper");
 627                                 return -EINVAL;
 628                         }
 629                         break;
 630                 default:
 631                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
 632                                   type);
 633                         return -EINVAL;
 634                 }
 635         }
 636
 637         if (rem > 0) {
 638                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
 639                 return -EINVAL;
 640         }
 641
 642         return 0;
 643 }
 644
 645 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
 646 {
 647         if (attr == OVS_KEY_ATTR_CT_STATE)
 648                 return true;
 649         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 650             attr == OVS_KEY_ATTR_CT_ZONE)
 651                 return true;
 652         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 653             attr == OVS_KEY_ATTR_CT_MARK)
 654                 return true;
 655         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 656             attr == OVS_KEY_ATTR_CT_LABELS) {
 657                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 658
 659                 return ovs_net->xt_label;
 660         }
 661
 662         return false;
 663 }
 664
 665 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 666                        const struct sw_flow_key *key,
 667                        struct sw_flow_actions **sfa,  bool log)
 668 {
 669         struct ovs_conntrack_info ct_info;
 670         const char *helper = NULL;
 671         u16 family;
 672         int err;
 673
 674         family = key_to_nfproto(key);
 675         if (family == NFPROTO_UNSPEC) {
 676                 OVS_NLERR(log, "ct family unspecified");
 677                 return -EINVAL;
 678         }
 679
 680         memset(&ct_info, 0, sizeof(ct_info));
 681         ct_info.family = family;
 682
 683         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
 684                         NF_CT_DEFAULT_ZONE_DIR, 0);
 685
 686         err = parse_ct(attr, &ct_info, &helper, log);
 687         if (err)
 688                 return err;
 689
 690         /* Set up template for tracking connections in specific zones. */
 691         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
 692         if (!ct_info.ct) {
 693                 OVS_NLERR(log, "Failed to allocate conntrack template");
 694                 return -ENOMEM;
 695         }
 696         if (helper) {
 697                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
 698                 if (err)
 699                         goto err_free_ct;
 700         }
 701
 702         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
 703                                  sizeof(ct_info), log);
 704         if (err)
 705                 goto err_free_ct;
 706
 707         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
 708         nf_conntrack_get(&ct_info.ct->ct_general);
 709         return 0;
 710 err_free_ct:
 711         nf_conntrack_free(ct_info.ct);
 712         return err;
 713 }
 714
 715 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
 716                           struct sk_buff *skb)
 717 {
 718         struct nlattr *start;
 719
 720         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
 721         if (!start)
 722                 return -EMSGSIZE;
 723
 724         if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
 725                 return -EMSGSIZE;
 726         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 727             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
 728                 return -EMSGSIZE;
 729         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
 730             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
 731                     &ct_info->mark))
 732                 return -EMSGSIZE;
 733         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 734             labels_nonzero(&ct_info->labels.mask) &&
 735             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
 736                     &ct_info->labels))
 737                 return -EMSGSIZE;
 738         if (ct_info->helper) {
 739                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
 740                                    ct_info->helper->name))
 741                         return -EMSGSIZE;
 742         }
 743
 744         nla_nest_end(skb, start);
 745
 746         return 0;
 747 }
 748
 749 void ovs_ct_free_action(const struct nlattr *a)
 750 {
 751         struct ovs_conntrack_info *ct_info = nla_data(a);
 752
 753         if (ct_info->helper)
 754                 module_put(ct_info->helper->me);
 755         if (ct_info->ct)
 756                 nf_ct_put(ct_info->ct);
 757 }
 758
 759 void ovs_ct_init(struct net *net)
 760 {
 761         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
 762         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 763
 764         if (nf_connlabels_get(net, n_bits)) {
 765                 ovs_net->xt_label = false;
 766                 OVS_NLERR(true, "Failed to set connlabel length");
 767         } else {
 768                 ovs_net->xt_label = true;
 769         }
 770 }
 771
 772 void ovs_ct_exit(struct net *net)
 773 {
 774         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 775
 776         if (ovs_net->xt_label)
 777                 nf_connlabels_put(net);
 778 }