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_label {
  41         struct ovs_key_ct_label value;
  42         struct ovs_key_ct_label 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         u32 flags;
  51         u16 family;
  52         struct md_mark mark;
  53         struct md_label label;
  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 void ovs_ct_get_label(const struct nf_conn *ct,
 104                              struct ovs_key_ct_label *label)
 105 {
 106         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
 107
 108         if (cl) {
 109                 size_t len = cl->words * sizeof(long);
 110
 111                 if (len > OVS_CT_LABEL_LEN)
 112                         len = OVS_CT_LABEL_LEN;
 113                 else if (len < OVS_CT_LABEL_LEN)
 114                         memset(label, 0, OVS_CT_LABEL_LEN);
 115                 memcpy(label, cl->bits, len);
 116         } else {
 117                 memset(label, 0, OVS_CT_LABEL_LEN);
 118         }
 119 }
 120
 121 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
 122                                 const struct nf_conntrack_zone *zone,
 123                                 const struct nf_conn *ct)
 124 {
 125         key->ct.state = state;
 126         key->ct.zone = zone->id;
 127         key->ct.mark = ct ? ct->mark : 0;
 128         ovs_ct_get_label(ct, &key->ct.label);
 129 }
 130
 131 /* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
 132  * previously sent the packet to conntrack via the ct action.
 133  */
 134 static void ovs_ct_update_key(const struct sk_buff *skb,
 135                               struct sw_flow_key *key, bool post_ct)
 136 {
 137         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 138         enum ip_conntrack_info ctinfo;
 139         struct nf_conn *ct;
 140         u8 state = 0;
 141
 142         ct = nf_ct_get(skb, &ctinfo);
 143         if (ct) {
 144                 state = ovs_ct_get_state(ctinfo);
 145                 if (ct->master)
 146                         state |= OVS_CS_F_RELATED;
 147                 zone = nf_ct_zone(ct);
 148         } else if (post_ct) {
 149                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 150         }
 151         __ovs_ct_update_key(key, state, zone, ct);
 152 }
 153
 154 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 155 {
 156         ovs_ct_update_key(skb, key, false);
 157 }
 158
 159 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 160 {
 161         if (nla_put_u8(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 162                 return -EMSGSIZE;
 163
 164         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 165             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 166                 return -EMSGSIZE;
 167
 168         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 169             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 170                 return -EMSGSIZE;
 171
 172         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABEL) &&
 173             nla_put(skb, OVS_KEY_ATTR_CT_LABEL, sizeof(key->ct.label),
 174                     &key->ct.label))
 175                 return -EMSGSIZE;
 176
 177         return 0;
 178 }
 179
 180 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 181                            u32 ct_mark, u32 mask)
 182 {
 183         enum ip_conntrack_info ctinfo;
 184         struct nf_conn *ct;
 185         u32 new_mark;
 186
 187         if (!IS_ENABLED(CONFIG_NF_CONNTRACK_MARK))
 188                 return -ENOTSUPP;
 189
 190         /* The connection could be invalid, in which case set_mark is no-op. */
 191         ct = nf_ct_get(skb, &ctinfo);
 192         if (!ct)
 193                 return 0;
 194
 195         new_mark = ct_mark | (ct->mark & ~(mask));
 196         if (ct->mark != new_mark) {
 197                 ct->mark = new_mark;
 198                 nf_conntrack_event_cache(IPCT_MARK, ct);
 199                 key->ct.mark = new_mark;
 200         }
 201
 202         return 0;
 203 }
 204
 205 static int ovs_ct_set_label(struct sk_buff *skb, struct sw_flow_key *key,
 206                             const struct ovs_key_ct_label *label,
 207                             const struct ovs_key_ct_label *mask)
 208 {
 209         enum ip_conntrack_info ctinfo;
 210         struct nf_conn_labels *cl;
 211         struct nf_conn *ct;
 212         int err;
 213
 214         if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS))
 215                 return -ENOTSUPP;
 216
 217         /* The connection could be invalid, in which case set_label is no-op.*/
 218         ct = nf_ct_get(skb, &ctinfo);
 219         if (!ct)
 220                 return 0;
 221
 222         cl = nf_ct_labels_find(ct);
 223         if (!cl) {
 224                 nf_ct_labels_ext_add(ct);
 225                 cl = nf_ct_labels_find(ct);
 226         }
 227         if (!cl || cl->words * sizeof(long) < OVS_CT_LABEL_LEN)
 228                 return -ENOSPC;
 229
 230         err = nf_connlabels_replace(ct, (u32 *)label, (u32 *)mask,
 231                                     OVS_CT_LABEL_LEN / sizeof(u32));
 232         if (err)
 233                 return err;
 234
 235         ovs_ct_get_label(ct, &key->ct.label);
 236         return 0;
 237 }
 238
 239 /* 'skb' should already be pulled to nh_ofs. */
 240 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 241 {
 242         const struct nf_conntrack_helper *helper;
 243         const struct nf_conn_help *help;
 244         enum ip_conntrack_info ctinfo;
 245         unsigned int protoff;
 246         struct nf_conn *ct;
 247
 248         ct = nf_ct_get(skb, &ctinfo);
 249         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 250                 return NF_ACCEPT;
 251
 252         help = nfct_help(ct);
 253         if (!help)
 254                 return NF_ACCEPT;
 255
 256         helper = rcu_dereference(help->helper);
 257         if (!helper)
 258                 return NF_ACCEPT;
 259
 260         switch (proto) {
 261         case NFPROTO_IPV4:
 262                 protoff = ip_hdrlen(skb);
 263                 break;
 264         case NFPROTO_IPV6: {
 265                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 266                 __be16 frag_off;
 267
 268                 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
 269                                            &nexthdr, &frag_off);
 270                 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
 271                         pr_debug("proto header not found\n");
 272                         return NF_ACCEPT;
 273                 }
 274                 break;
 275         }
 276         default:
 277                 WARN_ONCE(1, "helper invoked on non-IP family!");
 278                 return NF_DROP;
 279         }
 280
 281         return helper->help(skb, protoff, ct, ctinfo);
 282 }
 283
 284 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 285                             u16 zone, struct sk_buff *skb)
 286 {
 287         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 288
 289         if (key->eth.type == htons(ETH_P_IP)) {
 290                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 291                 int err;
 292
 293                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 294                 err = ip_defrag(skb, user);
 295                 if (err)
 296                         return err;
 297
 298                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 299         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 300 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 301                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 302                 struct sk_buff *reasm;
 303
 304                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 305                 reasm = nf_ct_frag6_gather(skb, user);
 306                 if (!reasm)
 307                         return -EINPROGRESS;
 308
 309                 if (skb == reasm)
 310                         return -EINVAL;
 311
 312                 key->ip.proto = ipv6_hdr(reasm)->nexthdr;
 313                 skb_morph(skb, reasm);
 314                 consume_skb(reasm);
 315                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 316 #else
 317                 return -EPFNOSUPPORT;
 318 #endif
 319         } else {
 320                 return -EPFNOSUPPORT;
 321         }
 322
 323         key->ip.frag = OVS_FRAG_TYPE_NONE;
 324         skb_clear_hash(skb);
 325         skb->ignore_df = 1;
 326         *OVS_CB(skb) = ovs_cb;
 327
 328         return 0;
 329 }
 330
 331 static struct nf_conntrack_expect *
 332 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 333                    u16 proto, const struct sk_buff *skb)
 334 {
 335         struct nf_conntrack_tuple tuple;
 336
 337         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, &tuple))
 338                 return NULL;
 339         return __nf_ct_expect_find(net, zone, &tuple);
 340 }
 341
 342 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
 343 static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
 344                             const struct ovs_conntrack_info *info)
 345 {
 346         enum ip_conntrack_info ctinfo;
 347         struct nf_conn *ct;
 348
 349         ct = nf_ct_get(skb, &ctinfo);
 350         if (!ct)
 351                 return false;
 352         if (!net_eq(net, read_pnet(&ct->ct_net)))
 353                 return false;
 354         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 355                 return false;
 356         if (info->helper) {
 357                 struct nf_conn_help *help;
 358
 359                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 360                 if (help && rcu_access_pointer(help->helper) != info->helper)
 361                         return false;
 362         }
 363
 364         return true;
 365 }
 366
 367 static int __ovs_ct_lookup(struct net *net, const struct sw_flow_key *key,
 368                            const struct ovs_conntrack_info *info,
 369                            struct sk_buff *skb)
 370 {
 371         /* If we are recirculating packets to match on conntrack fields and
 372          * committing with a separate conntrack action,  then we don't need to
 373          * actually run the packet through conntrack twice unless it's for a
 374          * different zone.
 375          */
 376         if (!skb_nfct_cached(net, skb, info)) {
 377                 struct nf_conn *tmpl = info->ct;
 378
 379                 /* Associate skb with specified zone. */
 380                 if (tmpl) {
 381                         if (skb->nfct)
 382                                 nf_conntrack_put(skb->nfct);
 383                         nf_conntrack_get(&tmpl->ct_general);
 384                         skb->nfct = &tmpl->ct_general;
 385                         skb->nfctinfo = IP_CT_NEW;
 386                 }
 387
 388                 if (nf_conntrack_in(net, info->family, NF_INET_PRE_ROUTING,
 389                                     skb) != NF_ACCEPT)
 390                         return -ENOENT;
 391
 392                 if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 393                         WARN_ONCE(1, "helper rejected packet");
 394                         return -EINVAL;
 395                 }
 396         }
 397
 398         return 0;
 399 }
 400
 401 /* Lookup connection and read fields into key. */
 402 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 403                          const struct ovs_conntrack_info *info,
 404                          struct sk_buff *skb)
 405 {
 406         struct nf_conntrack_expect *exp;
 407
 408         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 409         if (exp) {
 410                 u8 state;
 411
 412                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 413                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 414         } else {
 415                 int err;
 416
 417                 err = __ovs_ct_lookup(net, key, info, skb);
 418                 if (err)
 419                         return err;
 420
 421                 ovs_ct_update_key(skb, key, true);
 422         }
 423
 424         return 0;
 425 }
 426
 427 /* Lookup connection and confirm if unconfirmed. */
 428 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
 429                          const struct ovs_conntrack_info *info,
 430                          struct sk_buff *skb)
 431 {
 432         u8 state;
 433         int err;
 434
 435         state = key->ct.state;
 436         if (key->ct.zone == info->zone.id &&
 437             ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
 438                 /* Previous lookup has shown that this connection is already
 439                  * tracked and committed. Skip committing.
 440                  */
 441                 return 0;
 442         }
 443
 444         err = __ovs_ct_lookup(net, key, info, skb);
 445         if (err)
 446                 return err;
 447         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
 448                 return -EINVAL;
 449
 450         ovs_ct_update_key(skb, key, true);
 451
 452         return 0;
 453 }
 454
 455 static bool label_nonzero(const struct ovs_key_ct_label *label)
 456 {
 457         size_t i;
 458
 459         for (i = 0; i < sizeof(*label); i++)
 460                 if (label->ct_label[i])
 461                         return true;
 462
 463         return false;
 464 }
 465
 466 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 467                    struct sw_flow_key *key,
 468                    const struct ovs_conntrack_info *info)
 469 {
 470         int nh_ofs;
 471         int err;
 472
 473         /* The conntrack module expects to be working at L3. */
 474         nh_ofs = skb_network_offset(skb);
 475         skb_pull(skb, nh_ofs);
 476
 477         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 478                 err = handle_fragments(net, key, info->zone.id, skb);
 479                 if (err)
 480                         return err;
 481         }
 482
 483         if (info->flags & OVS_CT_F_COMMIT)
 484                 err = ovs_ct_commit(net, key, info, skb);
 485         else
 486                 err = ovs_ct_lookup(net, key, info, skb);
 487         if (err)
 488                 goto err;
 489
 490         if (info->mark.mask) {
 491                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 492                                       info->mark.mask);
 493                 if (err)
 494                         goto err;
 495         }
 496         if (label_nonzero(&info->label.mask))
 497                 err = ovs_ct_set_label(skb, key, &info->label.value,
 498                                        &info->label.mask);
 499 err:
 500         skb_push(skb, nh_ofs);
 501         return err;
 502 }
 503
 504 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 505                              const struct sw_flow_key *key, bool log)
 506 {
 507         struct nf_conntrack_helper *helper;
 508         struct nf_conn_help *help;
 509
 510         helper = nf_conntrack_helper_try_module_get(name, info->family,
 511                                                     key->ip.proto);
 512         if (!helper) {
 513                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 514                 return -EINVAL;
 515         }
 516
 517         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 518         if (!help) {
 519                 module_put(helper->me);
 520                 return -ENOMEM;
 521         }
 522
 523         rcu_assign_pointer(help->helper, helper);
 524         info->helper = helper;
 525         return 0;
 526 }
 527
 528 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
 529         [OVS_CT_ATTR_FLAGS]     = { .minlen = sizeof(u32),
 530                                     .maxlen = sizeof(u32) },
 531         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
 532                                     .maxlen = sizeof(u16) },
 533         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
 534                                     .maxlen = sizeof(struct md_mark) },
 535         [OVS_CT_ATTR_LABEL]     = { .minlen = sizeof(struct md_label),
 536                                     .maxlen = sizeof(struct md_label) },
 537         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
 538                                     .maxlen = NF_CT_HELPER_NAME_LEN }
 539 };
 540
 541 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
 542                     const char **helper, bool log)
 543 {
 544         struct nlattr *a;
 545         int rem;
 546
 547         nla_for_each_nested(a, attr, rem) {
 548                 int type = nla_type(a);
 549                 int maxlen = ovs_ct_attr_lens[type].maxlen;
 550                 int minlen = ovs_ct_attr_lens[type].minlen;
 551
 552                 if (type > OVS_CT_ATTR_MAX) {
 553                         OVS_NLERR(log,
 554                                   "Unknown conntrack attr (type=%d, max=%d)",
 555                                   type, OVS_CT_ATTR_MAX);
 556                         return -EINVAL;
 557                 }
 558                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
 559                         OVS_NLERR(log,
 560                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
 561                                   type, nla_len(a), maxlen);
 562                         return -EINVAL;
 563                 }
 564
 565                 switch (type) {
 566                 case OVS_CT_ATTR_FLAGS:
 567                         info->flags = nla_get_u32(a);
 568                         break;
 569 #ifdef CONFIG_NF_CONNTRACK_ZONES
 570                 case OVS_CT_ATTR_ZONE:
 571                         info->zone.id = nla_get_u16(a);
 572                         break;
 573 #endif
 574 #ifdef CONFIG_NF_CONNTRACK_MARK
 575                 case OVS_CT_ATTR_MARK: {
 576                         struct md_mark *mark = nla_data(a);
 577
 578                         info->mark = *mark;
 579                         break;
 580                 }
 581 #endif
 582 #ifdef CONFIG_NF_CONNTRACK_LABELS
 583                 case OVS_CT_ATTR_LABEL: {
 584                         struct md_label *label = nla_data(a);
 585
 586                         info->label = *label;
 587                         break;
 588                 }
 589 #endif
 590                 case OVS_CT_ATTR_HELPER:
 591                         *helper = nla_data(a);
 592                         if (!memchr(*helper, '\0', nla_len(a))) {
 593                                 OVS_NLERR(log, "Invalid conntrack helper");
 594                                 return -EINVAL;
 595                         }
 596                         break;
 597                 default:
 598                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
 599                                   type);
 600                         return -EINVAL;
 601                 }
 602         }
 603
 604         if (rem > 0) {
 605                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
 606                 return -EINVAL;
 607         }
 608
 609         return 0;
 610 }
 611
 612 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
 613 {
 614         if (attr == OVS_KEY_ATTR_CT_STATE)
 615                 return true;
 616         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 617             attr == OVS_KEY_ATTR_CT_ZONE)
 618                 return true;
 619         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 620             attr == OVS_KEY_ATTR_CT_MARK)
 621                 return true;
 622         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 623             attr == OVS_KEY_ATTR_CT_LABEL) {
 624                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 625
 626                 return ovs_net->xt_label;
 627         }
 628
 629         return false;
 630 }
 631
 632 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 633                        const struct sw_flow_key *key,
 634                        struct sw_flow_actions **sfa,  bool log)
 635 {
 636         struct ovs_conntrack_info ct_info;
 637         const char *helper = NULL;
 638         u16 family;
 639         int err;
 640
 641         family = key_to_nfproto(key);
 642         if (family == NFPROTO_UNSPEC) {
 643                 OVS_NLERR(log, "ct family unspecified");
 644                 return -EINVAL;
 645         }
 646
 647         memset(&ct_info, 0, sizeof(ct_info));
 648         ct_info.family = family;
 649
 650         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
 651                         NF_CT_DEFAULT_ZONE_DIR, 0);
 652
 653         err = parse_ct(attr, &ct_info, &helper, log);
 654         if (err)
 655                 return err;
 656
 657         /* Set up template for tracking connections in specific zones. */
 658         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
 659         if (!ct_info.ct) {
 660                 OVS_NLERR(log, "Failed to allocate conntrack template");
 661                 return -ENOMEM;
 662         }
 663         if (helper) {
 664                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
 665                 if (err)
 666                         goto err_free_ct;
 667         }
 668
 669         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
 670                                  sizeof(ct_info), log);
 671         if (err)
 672                 goto err_free_ct;
 673
 674         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
 675         nf_conntrack_get(&ct_info.ct->ct_general);
 676         return 0;
 677 err_free_ct:
 678         nf_conntrack_free(ct_info.ct);
 679         return err;
 680 }
 681
 682 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
 683                           struct sk_buff *skb)
 684 {
 685         struct nlattr *start;
 686
 687         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
 688         if (!start)
 689                 return -EMSGSIZE;
 690
 691         if (nla_put_u32(skb, OVS_CT_ATTR_FLAGS, ct_info->flags))
 692                 return -EMSGSIZE;
 693         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 694             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
 695                 return -EMSGSIZE;
 696         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 697             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
 698                     &ct_info->mark))
 699                 return -EMSGSIZE;
 700         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 701             nla_put(skb, OVS_CT_ATTR_LABEL, sizeof(ct_info->label),
 702                     &ct_info->label))
 703                 return -EMSGSIZE;
 704         if (ct_info->helper) {
 705                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
 706                                    ct_info->helper->name))
 707                         return -EMSGSIZE;
 708         }
 709
 710         nla_nest_end(skb, start);
 711
 712         return 0;
 713 }
 714
 715 void ovs_ct_free_action(const struct nlattr *a)
 716 {
 717         struct ovs_conntrack_info *ct_info = nla_data(a);
 718
 719         if (ct_info->helper)
 720                 module_put(ct_info->helper->me);
 721         if (ct_info->ct)
 722                 nf_ct_put(ct_info->ct);
 723 }
 724
 725 void ovs_ct_init(struct net *net)
 726 {
 727         unsigned int n_bits = sizeof(struct ovs_key_ct_label) * BITS_PER_BYTE;
 728         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 729
 730         if (nf_connlabels_get(net, n_bits)) {
 731                 ovs_net->xt_label = false;
 732                 OVS_NLERR(true, "Failed to set connlabel length");
 733         } else {
 734                 ovs_net->xt_label = true;
 735         }
 736 }
 737
 738 void ovs_ct_exit(struct net *net)
 739 {
 740         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 741
 742         if (ovs_net->xt_label)
 743                 nf_connlabels_put(net);
 744 }