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 (ct->master)
 155                         state |= OVS_CS_F_RELATED;
 156                 zone = nf_ct_zone(ct);
 157         } else if (post_ct) {
 158                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 159         }
 160         __ovs_ct_update_key(key, state, zone, ct);
 161 }
 162
 163 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 164 {
 165         ovs_ct_update_key(skb, key, false);
 166 }
 167
 168 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 169 {
 170         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 171                 return -EMSGSIZE;
 172
 173         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 174             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 175                 return -EMSGSIZE;
 176
 177         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 178             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 179                 return -EMSGSIZE;
 180
 181         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 182             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
 183                     &key->ct.labels))
 184                 return -EMSGSIZE;
 185
 186         return 0;
 187 }
 188
 189 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 190                            u32 ct_mark, u32 mask)
 191 {
 192 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 193         enum ip_conntrack_info ctinfo;
 194         struct nf_conn *ct;
 195         u32 new_mark;
 196
 197
 198         /* The connection could be invalid, in which case set_mark is no-op. */
 199         ct = nf_ct_get(skb, &ctinfo);
 200         if (!ct)
 201                 return 0;
 202
 203         new_mark = ct_mark | (ct->mark & ~(mask));
 204         if (ct->mark != new_mark) {
 205                 ct->mark = new_mark;
 206                 nf_conntrack_event_cache(IPCT_MARK, ct);
 207                 key->ct.mark = new_mark;
 208         }
 209
 210         return 0;
 211 #else
 212         return -ENOTSUPP;
 213 #endif
 214 }
 215
 216 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
 217                              const struct ovs_key_ct_labels *labels,
 218                              const struct ovs_key_ct_labels *mask)
 219 {
 220         enum ip_conntrack_info ctinfo;
 221         struct nf_conn_labels *cl;
 222         struct nf_conn *ct;
 223         int err;
 224
 225         if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS))
 226                 return -ENOTSUPP;
 227
 228         /* The connection could be invalid, in which case set_label is no-op.*/
 229         ct = nf_ct_get(skb, &ctinfo);
 230         if (!ct)
 231                 return 0;
 232
 233         cl = nf_ct_labels_find(ct);
 234         if (!cl) {
 235                 nf_ct_labels_ext_add(ct);
 236                 cl = nf_ct_labels_find(ct);
 237         }
 238         if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
 239                 return -ENOSPC;
 240
 241         err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
 242                                     OVS_CT_LABELS_LEN / sizeof(u32));
 243         if (err)
 244                 return err;
 245
 246         ovs_ct_get_labels(ct, &key->ct.labels);
 247         return 0;
 248 }
 249
 250 /* 'skb' should already be pulled to nh_ofs. */
 251 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 252 {
 253         const struct nf_conntrack_helper *helper;
 254         const struct nf_conn_help *help;
 255         enum ip_conntrack_info ctinfo;
 256         unsigned int protoff;
 257         struct nf_conn *ct;
 258
 259         ct = nf_ct_get(skb, &ctinfo);
 260         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 261                 return NF_ACCEPT;
 262
 263         help = nfct_help(ct);
 264         if (!help)
 265                 return NF_ACCEPT;
 266
 267         helper = rcu_dereference(help->helper);
 268         if (!helper)
 269                 return NF_ACCEPT;
 270
 271         switch (proto) {
 272         case NFPROTO_IPV4:
 273                 protoff = ip_hdrlen(skb);
 274                 break;
 275         case NFPROTO_IPV6: {
 276                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 277                 __be16 frag_off;
 278                 int ofs;
 279
 280                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 281                                        &frag_off);
 282                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 283                         pr_debug("proto header not found\n");
 284                         return NF_ACCEPT;
 285                 }
 286                 protoff = ofs;
 287                 break;
 288         }
 289         default:
 290                 WARN_ONCE(1, "helper invoked on non-IP family!");
 291                 return NF_DROP;
 292         }
 293
 294         return helper->help(skb, protoff, ct, ctinfo);
 295 }
 296
 297 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 298                             u16 zone, struct sk_buff *skb)
 299 {
 300         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 301
 302         if (key->eth.type == htons(ETH_P_IP)) {
 303                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 304                 int err;
 305
 306                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 307                 err = ip_defrag(skb, user);
 308                 if (err)
 309                         return err;
 310
 311                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 312         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 313 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 314                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 315                 struct sk_buff *reasm;
 316
 317                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 318                 reasm = nf_ct_frag6_gather(skb, user);
 319                 if (!reasm)
 320                         return -EINPROGRESS;
 321
 322                 if (skb == reasm)
 323                         return -EINVAL;
 324
 325                 key->ip.proto = ipv6_hdr(reasm)->nexthdr;
 326                 skb_morph(skb, reasm);
 327                 consume_skb(reasm);
 328                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 329 #else
 330                 return -EPFNOSUPPORT;
 331 #endif
 332         } else {
 333                 return -EPFNOSUPPORT;
 334         }
 335
 336         key->ip.frag = OVS_FRAG_TYPE_NONE;
 337         skb_clear_hash(skb);
 338         skb->ignore_df = 1;
 339         *OVS_CB(skb) = ovs_cb;
 340
 341         return 0;
 342 }
 343
 344 static struct nf_conntrack_expect *
 345 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 346                    u16 proto, const struct sk_buff *skb)
 347 {
 348         struct nf_conntrack_tuple tuple;
 349
 350         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, &tuple))
 351                 return NULL;
 352         return __nf_ct_expect_find(net, zone, &tuple);
 353 }
 354
 355 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
 356 static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
 357                             const struct ovs_conntrack_info *info)
 358 {
 359         enum ip_conntrack_info ctinfo;
 360         struct nf_conn *ct;
 361
 362         ct = nf_ct_get(skb, &ctinfo);
 363         if (!ct)
 364                 return false;
 365         if (!net_eq(net, read_pnet(&ct->ct_net)))
 366                 return false;
 367         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 368                 return false;
 369         if (info->helper) {
 370                 struct nf_conn_help *help;
 371
 372                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 373                 if (help && rcu_access_pointer(help->helper) != info->helper)
 374                         return false;
 375         }
 376
 377         return true;
 378 }
 379
 380 static int __ovs_ct_lookup(struct net *net, const struct sw_flow_key *key,
 381                            const struct ovs_conntrack_info *info,
 382                            struct sk_buff *skb)
 383 {
 384         /* If we are recirculating packets to match on conntrack fields and
 385          * committing with a separate conntrack action,  then we don't need to
 386          * actually run the packet through conntrack twice unless it's for a
 387          * different zone.
 388          */
 389         if (!skb_nfct_cached(net, skb, info)) {
 390                 struct nf_conn *tmpl = info->ct;
 391
 392                 /* Associate skb with specified zone. */
 393                 if (tmpl) {
 394                         if (skb->nfct)
 395                                 nf_conntrack_put(skb->nfct);
 396                         nf_conntrack_get(&tmpl->ct_general);
 397                         skb->nfct = &tmpl->ct_general;
 398                         skb->nfctinfo = IP_CT_NEW;
 399                 }
 400
 401                 if (nf_conntrack_in(net, info->family, NF_INET_PRE_ROUTING,
 402                                     skb) != NF_ACCEPT)
 403                         return -ENOENT;
 404
 405                 if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 406                         WARN_ONCE(1, "helper rejected packet");
 407                         return -EINVAL;
 408                 }
 409         }
 410
 411         return 0;
 412 }
 413
 414 /* Lookup connection and read fields into key. */
 415 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 416                          const struct ovs_conntrack_info *info,
 417                          struct sk_buff *skb)
 418 {
 419         struct nf_conntrack_expect *exp;
 420
 421         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 422         if (exp) {
 423                 u8 state;
 424
 425                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 426                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 427         } else {
 428                 int err;
 429
 430                 err = __ovs_ct_lookup(net, key, info, skb);
 431                 if (err)
 432                         return err;
 433
 434                 ovs_ct_update_key(skb, key, true);
 435         }
 436
 437         return 0;
 438 }
 439
 440 /* Lookup connection and confirm if unconfirmed. */
 441 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
 442                          const struct ovs_conntrack_info *info,
 443                          struct sk_buff *skb)
 444 {
 445         u8 state;
 446         int err;
 447
 448         state = key->ct.state;
 449         if (key->ct.zone == info->zone.id &&
 450             ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
 451                 /* Previous lookup has shown that this connection is already
 452                  * tracked and committed. Skip committing.
 453                  */
 454                 return 0;
 455         }
 456
 457         err = __ovs_ct_lookup(net, key, info, skb);
 458         if (err)
 459                 return err;
 460         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
 461                 return -EINVAL;
 462
 463         ovs_ct_update_key(skb, key, true);
 464
 465         return 0;
 466 }
 467
 468 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
 469 {
 470         size_t i;
 471
 472         for (i = 0; i < sizeof(*labels); i++)
 473                 if (labels->ct_labels[i])
 474                         return true;
 475
 476         return false;
 477 }
 478
 479 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 480                    struct sw_flow_key *key,
 481                    const struct ovs_conntrack_info *info)
 482 {
 483         int nh_ofs;
 484         int err;
 485
 486         /* The conntrack module expects to be working at L3. */
 487         nh_ofs = skb_network_offset(skb);
 488         skb_pull(skb, nh_ofs);
 489
 490         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 491                 err = handle_fragments(net, key, info->zone.id, skb);
 492                 if (err)
 493                         return err;
 494         }
 495
 496         if (info->commit)
 497                 err = ovs_ct_commit(net, key, info, skb);
 498         else
 499                 err = ovs_ct_lookup(net, key, info, skb);
 500         if (err)
 501                 goto err;
 502
 503         if (info->mark.mask) {
 504                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 505                                       info->mark.mask);
 506                 if (err)
 507                         goto err;
 508         }
 509         if (labels_nonzero(&info->labels.mask))
 510                 err = ovs_ct_set_labels(skb, key, &info->labels.value,
 511                                         &info->labels.mask);
 512 err:
 513         skb_push(skb, nh_ofs);
 514         return err;
 515 }
 516
 517 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 518                              const struct sw_flow_key *key, bool log)
 519 {
 520         struct nf_conntrack_helper *helper;
 521         struct nf_conn_help *help;
 522
 523         helper = nf_conntrack_helper_try_module_get(name, info->family,
 524                                                     key->ip.proto);
 525         if (!helper) {
 526                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 527                 return -EINVAL;
 528         }
 529
 530         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 531         if (!help) {
 532                 module_put(helper->me);
 533                 return -ENOMEM;
 534         }
 535
 536         rcu_assign_pointer(help->helper, helper);
 537         info->helper = helper;
 538         return 0;
 539 }
 540
 541 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
 542         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
 543         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
 544                                     .maxlen = sizeof(u16) },
 545         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
 546                                     .maxlen = sizeof(struct md_mark) },
 547         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
 548                                     .maxlen = sizeof(struct md_labels) },
 549         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
 550                                     .maxlen = NF_CT_HELPER_NAME_LEN }
 551 };
 552
 553 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
 554                     const char **helper, bool log)
 555 {
 556         struct nlattr *a;
 557         int rem;
 558
 559         nla_for_each_nested(a, attr, rem) {
 560                 int type = nla_type(a);
 561                 int maxlen = ovs_ct_attr_lens[type].maxlen;
 562                 int minlen = ovs_ct_attr_lens[type].minlen;
 563
 564                 if (type > OVS_CT_ATTR_MAX) {
 565                         OVS_NLERR(log,
 566                                   "Unknown conntrack attr (type=%d, max=%d)",
 567                                   type, OVS_CT_ATTR_MAX);
 568                         return -EINVAL;
 569                 }
 570                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
 571                         OVS_NLERR(log,
 572                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
 573                                   type, nla_len(a), maxlen);
 574                         return -EINVAL;
 575                 }
 576
 577                 switch (type) {
 578                 case OVS_CT_ATTR_COMMIT:
 579                         info->commit = true;
 580                         break;
 581 #ifdef CONFIG_NF_CONNTRACK_ZONES
 582                 case OVS_CT_ATTR_ZONE:
 583                         info->zone.id = nla_get_u16(a);
 584                         break;
 585 #endif
 586 #ifdef CONFIG_NF_CONNTRACK_MARK
 587                 case OVS_CT_ATTR_MARK: {
 588                         struct md_mark *mark = nla_data(a);
 589
 590                         info->mark = *mark;
 591                         break;
 592                 }
 593 #endif
 594 #ifdef CONFIG_NF_CONNTRACK_LABELS
 595                 case OVS_CT_ATTR_LABELS: {
 596                         struct md_labels *labels = nla_data(a);
 597
 598                         info->labels = *labels;
 599                         break;
 600                 }
 601 #endif
 602                 case OVS_CT_ATTR_HELPER:
 603                         *helper = nla_data(a);
 604                         if (!memchr(*helper, '\0', nla_len(a))) {
 605                                 OVS_NLERR(log, "Invalid conntrack helper");
 606                                 return -EINVAL;
 607                         }
 608                         break;
 609                 default:
 610                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
 611                                   type);
 612                         return -EINVAL;
 613                 }
 614         }
 615
 616         if (rem > 0) {
 617                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
 618                 return -EINVAL;
 619         }
 620
 621         return 0;
 622 }
 623
 624 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
 625 {
 626         if (attr == OVS_KEY_ATTR_CT_STATE)
 627                 return true;
 628         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 629             attr == OVS_KEY_ATTR_CT_ZONE)
 630                 return true;
 631         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 632             attr == OVS_KEY_ATTR_CT_MARK)
 633                 return true;
 634         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 635             attr == OVS_KEY_ATTR_CT_LABELS) {
 636                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 637
 638                 return ovs_net->xt_label;
 639         }
 640
 641         return false;
 642 }
 643
 644 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 645                        const struct sw_flow_key *key,
 646                        struct sw_flow_actions **sfa,  bool log)
 647 {
 648         struct ovs_conntrack_info ct_info;
 649         const char *helper = NULL;
 650         u16 family;
 651         int err;
 652
 653         family = key_to_nfproto(key);
 654         if (family == NFPROTO_UNSPEC) {
 655                 OVS_NLERR(log, "ct family unspecified");
 656                 return -EINVAL;
 657         }
 658
 659         memset(&ct_info, 0, sizeof(ct_info));
 660         ct_info.family = family;
 661
 662         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
 663                         NF_CT_DEFAULT_ZONE_DIR, 0);
 664
 665         err = parse_ct(attr, &ct_info, &helper, log);
 666         if (err)
 667                 return err;
 668
 669         /* Set up template for tracking connections in specific zones. */
 670         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
 671         if (!ct_info.ct) {
 672                 OVS_NLERR(log, "Failed to allocate conntrack template");
 673                 return -ENOMEM;
 674         }
 675         if (helper) {
 676                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
 677                 if (err)
 678                         goto err_free_ct;
 679         }
 680
 681         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
 682                                  sizeof(ct_info), log);
 683         if (err)
 684                 goto err_free_ct;
 685
 686         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
 687         nf_conntrack_get(&ct_info.ct->ct_general);
 688         return 0;
 689 err_free_ct:
 690         nf_conntrack_free(ct_info.ct);
 691         return err;
 692 }
 693
 694 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
 695                           struct sk_buff *skb)
 696 {
 697         struct nlattr *start;
 698
 699         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
 700         if (!start)
 701                 return -EMSGSIZE;
 702
 703         if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
 704                 return -EMSGSIZE;
 705         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 706             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
 707                 return -EMSGSIZE;
 708         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 709             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
 710                     &ct_info->mark))
 711                 return -EMSGSIZE;
 712         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 713             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
 714                     &ct_info->labels))
 715                 return -EMSGSIZE;
 716         if (ct_info->helper) {
 717                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
 718                                    ct_info->helper->name))
 719                         return -EMSGSIZE;
 720         }
 721
 722         nla_nest_end(skb, start);
 723
 724         return 0;
 725 }
 726
 727 void ovs_ct_free_action(const struct nlattr *a)
 728 {
 729         struct ovs_conntrack_info *ct_info = nla_data(a);
 730
 731         if (ct_info->helper)
 732                 module_put(ct_info->helper->me);
 733         if (ct_info->ct)
 734                 nf_ct_put(ct_info->ct);
 735 }
 736
 737 void ovs_ct_init(struct net *net)
 738 {
 739         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
 740         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 741
 742         if (nf_connlabels_get(net, n_bits)) {
 743                 ovs_net->xt_label = false;
 744                 OVS_NLERR(true, "Failed to set connlabel length");
 745         } else {
 746                 ovs_net->xt_label = true;
 747         }
 748 }
 749
 750 void ovs_ct_exit(struct net *net)
 751 {
 752         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 753
 754         if (ovs_net->xt_label)
 755                 nf_connlabels_put(net);
 756 }