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 void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
  57
  58 static u16 key_to_nfproto(const struct sw_flow_key *key)
  59 {
  60         switch (ntohs(key->eth.type)) {
  61         case ETH_P_IP:
  62                 return NFPROTO_IPV4;
  63         case ETH_P_IPV6:
  64                 return NFPROTO_IPV6;
  65         default:
  66                 return NFPROTO_UNSPEC;
  67         }
  68 }
  69
  70 /* Map SKB connection state into the values used by flow definition. */
  71 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
  72 {
  73         u8 ct_state = OVS_CS_F_TRACKED;
  74
  75         switch (ctinfo) {
  76         case IP_CT_ESTABLISHED_REPLY:
  77         case IP_CT_RELATED_REPLY:
  78         case IP_CT_NEW_REPLY:
  79                 ct_state |= OVS_CS_F_REPLY_DIR;
  80                 break;
  81         default:
  82                 break;
  83         }
  84
  85         switch (ctinfo) {
  86         case IP_CT_ESTABLISHED:
  87         case IP_CT_ESTABLISHED_REPLY:
  88                 ct_state |= OVS_CS_F_ESTABLISHED;
  89                 break;
  90         case IP_CT_RELATED:
  91         case IP_CT_RELATED_REPLY:
  92                 ct_state |= OVS_CS_F_RELATED;
  93                 break;
  94         case IP_CT_NEW:
  95         case IP_CT_NEW_REPLY:
  96                 ct_state |= OVS_CS_F_NEW;
  97                 break;
  98         default:
  99                 break;
 100         }
 101
 102         return ct_state;
 103 }
 104
 105 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
 106 {
 107 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 108         return ct ? ct->mark : 0;
 109 #else
 110         return 0;
 111 #endif
 112 }
 113
 114 static void ovs_ct_get_labels(const struct nf_conn *ct,
 115                               struct ovs_key_ct_labels *labels)
 116 {
 117         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
 118
 119         if (cl) {
 120                 size_t len = cl->words * sizeof(long);
 121
 122                 if (len > OVS_CT_LABELS_LEN)
 123                         len = OVS_CT_LABELS_LEN;
 124                 else if (len < OVS_CT_LABELS_LEN)
 125                         memset(labels, 0, OVS_CT_LABELS_LEN);
 126                 memcpy(labels, cl->bits, len);
 127         } else {
 128                 memset(labels, 0, OVS_CT_LABELS_LEN);
 129         }
 130 }
 131
 132 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
 133                                 const struct nf_conntrack_zone *zone,
 134                                 const struct nf_conn *ct)
 135 {
 136         key->ct.state = state;
 137         key->ct.zone = zone->id;
 138         key->ct.mark = ovs_ct_get_mark(ct);
 139         ovs_ct_get_labels(ct, &key->ct.labels);
 140 }
 141
 142 /* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
 143  * previously sent the packet to conntrack via the ct action.
 144  */
 145 static void ovs_ct_update_key(const struct sk_buff *skb,
 146                               const struct ovs_conntrack_info *info,
 147                               struct sw_flow_key *key, bool post_ct)
 148 {
 149         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 150         enum ip_conntrack_info ctinfo;
 151         struct nf_conn *ct;
 152         u8 state = 0;
 153
 154         ct = nf_ct_get(skb, &ctinfo);
 155         if (ct) {
 156                 state = ovs_ct_get_state(ctinfo);
 157                 if (!nf_ct_is_confirmed(ct))
 158                         state |= OVS_CS_F_NEW;
 159                 if (ct->master)
 160                         state |= OVS_CS_F_RELATED;
 161                 zone = nf_ct_zone(ct);
 162         } else if (post_ct) {
 163                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 164                 if (info)
 165                         zone = &info->zone;
 166         }
 167         __ovs_ct_update_key(key, state, zone, ct);
 168 }
 169
 170 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 171 {
 172         ovs_ct_update_key(skb, NULL, key, false);
 173 }
 174
 175 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 176 {
 177         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 178                 return -EMSGSIZE;
 179
 180         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 181             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 182                 return -EMSGSIZE;
 183
 184         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 185             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 186                 return -EMSGSIZE;
 187
 188         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 189             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
 190                     &key->ct.labels))
 191                 return -EMSGSIZE;
 192
 193         return 0;
 194 }
 195
 196 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 197                            u32 ct_mark, u32 mask)
 198 {
 199 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 200         enum ip_conntrack_info ctinfo;
 201         struct nf_conn *ct;
 202         u32 new_mark;
 203
 204
 205         /* The connection could be invalid, in which case set_mark is no-op. */
 206         ct = nf_ct_get(skb, &ctinfo);
 207         if (!ct)
 208                 return 0;
 209
 210         new_mark = ct_mark | (ct->mark & ~(mask));
 211         if (ct->mark != new_mark) {
 212                 ct->mark = new_mark;
 213                 nf_conntrack_event_cache(IPCT_MARK, ct);
 214                 key->ct.mark = new_mark;
 215         }
 216
 217         return 0;
 218 #else
 219         return -ENOTSUPP;
 220 #endif
 221 }
 222
 223 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
 224                              const struct ovs_key_ct_labels *labels,
 225                              const struct ovs_key_ct_labels *mask)
 226 {
 227         enum ip_conntrack_info ctinfo;
 228         struct nf_conn_labels *cl;
 229         struct nf_conn *ct;
 230         int err;
 231
 232         /* The connection could be invalid, in which case set_label is no-op.*/
 233         ct = nf_ct_get(skb, &ctinfo);
 234         if (!ct)
 235                 return 0;
 236
 237         cl = nf_ct_labels_find(ct);
 238         if (!cl) {
 239                 nf_ct_labels_ext_add(ct);
 240                 cl = nf_ct_labels_find(ct);
 241         }
 242         if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
 243                 return -ENOSPC;
 244
 245         err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
 246                                     OVS_CT_LABELS_LEN / sizeof(u32));
 247         if (err)
 248                 return err;
 249
 250         ovs_ct_get_labels(ct, &key->ct.labels);
 251         return 0;
 252 }
 253
 254 /* 'skb' should already be pulled to nh_ofs. */
 255 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 256 {
 257         const struct nf_conntrack_helper *helper;
 258         const struct nf_conn_help *help;
 259         enum ip_conntrack_info ctinfo;
 260         unsigned int protoff;
 261         struct nf_conn *ct;
 262
 263         ct = nf_ct_get(skb, &ctinfo);
 264         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 265                 return NF_ACCEPT;
 266
 267         help = nfct_help(ct);
 268         if (!help)
 269                 return NF_ACCEPT;
 270
 271         helper = rcu_dereference(help->helper);
 272         if (!helper)
 273                 return NF_ACCEPT;
 274
 275         switch (proto) {
 276         case NFPROTO_IPV4:
 277                 protoff = ip_hdrlen(skb);
 278                 break;
 279         case NFPROTO_IPV6: {
 280                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 281                 __be16 frag_off;
 282                 int ofs;
 283
 284                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 285                                        &frag_off);
 286                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 287                         pr_debug("proto header not found\n");
 288                         return NF_ACCEPT;
 289                 }
 290                 protoff = ofs;
 291                 break;
 292         }
 293         default:
 294                 WARN_ONCE(1, "helper invoked on non-IP family!");
 295                 return NF_DROP;
 296         }
 297
 298         return helper->help(skb, protoff, ct, ctinfo);
 299 }
 300
 301 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 302  * value if 'skb' is freed.
 303  */
 304 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 305                             u16 zone, struct sk_buff *skb)
 306 {
 307         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 308         int err;
 309
 310         if (key->eth.type == htons(ETH_P_IP)) {
 311                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 312
 313                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 314                 err = ip_defrag(net, skb, user);
 315                 if (err)
 316                         return err;
 317
 318                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 319 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 320         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 321                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 322
 323                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 324                 err = nf_ct_frag6_gather(net, skb, user);
 325                 if (err)
 326                         return err;
 327
 328                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
 329                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 330 #endif
 331         } else {
 332                 kfree_skb(skb);
 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, net, &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, 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         ovs_ct_update_key(skb, info, key, true);
 412
 413         return 0;
 414 }
 415
 416 /* Lookup connection and read fields into key. */
 417 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 418                          const struct ovs_conntrack_info *info,
 419                          struct sk_buff *skb)
 420 {
 421         struct nf_conntrack_expect *exp;
 422
 423         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 424         if (exp) {
 425                 u8 state;
 426
 427                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 428                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 429         } else {
 430                 int err;
 431
 432                 err = __ovs_ct_lookup(net, key, info, skb);
 433                 if (err)
 434                         return err;
 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         return 0;
 464 }
 465
 466 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
 467 {
 468         size_t i;
 469
 470         for (i = 0; i < sizeof(*labels); i++)
 471                 if (labels->ct_labels[i])
 472                         return true;
 473
 474         return false;
 475 }
 476
 477 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 478  * value if 'skb' is freed.
 479  */
 480 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 481                    struct sw_flow_key *key,
 482                    const struct ovs_conntrack_info *info)
 483 {
 484         int nh_ofs;
 485         int err;
 486
 487         /* The conntrack module expects to be working at L3. */
 488         nh_ofs = skb_network_offset(skb);
 489         skb_pull(skb, nh_ofs);
 490
 491         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 492                 err = handle_fragments(net, key, info->zone.id, skb);
 493                 if (err)
 494                         return err;
 495         }
 496
 497         if (info->commit)
 498                 err = ovs_ct_commit(net, key, info, skb);
 499         else
 500                 err = ovs_ct_lookup(net, key, info, skb);
 501         if (err)
 502                 goto err;
 503
 504         if (info->mark.mask) {
 505                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 506                                       info->mark.mask);
 507                 if (err)
 508                         goto err;
 509         }
 510         if (labels_nonzero(&info->labels.mask))
 511                 err = ovs_ct_set_labels(skb, key, &info->labels.value,
 512                                         &info->labels.mask);
 513 err:
 514         skb_push(skb, nh_ofs);
 515         if (err)
 516                 kfree_skb(skb);
 517         return err;
 518 }
 519
 520 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 521                              const struct sw_flow_key *key, bool log)
 522 {
 523         struct nf_conntrack_helper *helper;
 524         struct nf_conn_help *help;
 525
 526         helper = nf_conntrack_helper_try_module_get(name, info->family,
 527                                                     key->ip.proto);
 528         if (!helper) {
 529                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 530                 return -EINVAL;
 531         }
 532
 533         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 534         if (!help) {
 535                 module_put(helper->me);
 536                 return -ENOMEM;
 537         }
 538
 539         rcu_assign_pointer(help->helper, helper);
 540         info->helper = helper;
 541         return 0;
 542 }
 543
 544 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
 545         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
 546         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
 547                                     .maxlen = sizeof(u16) },
 548         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
 549                                     .maxlen = sizeof(struct md_mark) },
 550         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
 551                                     .maxlen = sizeof(struct md_labels) },
 552         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
 553                                     .maxlen = NF_CT_HELPER_NAME_LEN }
 554 };
 555
 556 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
 557                     const char **helper, bool log)
 558 {
 559         struct nlattr *a;
 560         int rem;
 561
 562         nla_for_each_nested(a, attr, rem) {
 563                 int type = nla_type(a);
 564                 int maxlen = ovs_ct_attr_lens[type].maxlen;
 565                 int minlen = ovs_ct_attr_lens[type].minlen;
 566
 567                 if (type > OVS_CT_ATTR_MAX) {
 568                         OVS_NLERR(log,
 569                                   "Unknown conntrack attr (type=%d, max=%d)",
 570                                   type, OVS_CT_ATTR_MAX);
 571                         return -EINVAL;
 572                 }
 573                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
 574                         OVS_NLERR(log,
 575                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
 576                                   type, nla_len(a), maxlen);
 577                         return -EINVAL;
 578                 }
 579
 580                 switch (type) {
 581                 case OVS_CT_ATTR_COMMIT:
 582                         info->commit = true;
 583                         break;
 584 #ifdef CONFIG_NF_CONNTRACK_ZONES
 585                 case OVS_CT_ATTR_ZONE:
 586                         info->zone.id = nla_get_u16(a);
 587                         break;
 588 #endif
 589 #ifdef CONFIG_NF_CONNTRACK_MARK
 590                 case OVS_CT_ATTR_MARK: {
 591                         struct md_mark *mark = nla_data(a);
 592
 593                         if (!mark->mask) {
 594                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
 595                                 return -EINVAL;
 596                         }
 597                         info->mark = *mark;
 598                         break;
 599                 }
 600 #endif
 601 #ifdef CONFIG_NF_CONNTRACK_LABELS
 602                 case OVS_CT_ATTR_LABELS: {
 603                         struct md_labels *labels = nla_data(a);
 604
 605                         if (!labels_nonzero(&labels->mask)) {
 606                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
 607                                 return -EINVAL;
 608                         }
 609                         info->labels = *labels;
 610                         break;
 611                 }
 612 #endif
 613                 case OVS_CT_ATTR_HELPER:
 614                         *helper = nla_data(a);
 615                         if (!memchr(*helper, '\0', nla_len(a))) {
 616                                 OVS_NLERR(log, "Invalid conntrack helper");
 617                                 return -EINVAL;
 618                         }
 619                         break;
 620                 default:
 621                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
 622                                   type);
 623                         return -EINVAL;
 624                 }
 625         }
 626
 627         if (rem > 0) {
 628                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
 629                 return -EINVAL;
 630         }
 631
 632         return 0;
 633 }
 634
 635 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
 636 {
 637         if (attr == OVS_KEY_ATTR_CT_STATE)
 638                 return true;
 639         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 640             attr == OVS_KEY_ATTR_CT_ZONE)
 641                 return true;
 642         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 643             attr == OVS_KEY_ATTR_CT_MARK)
 644                 return true;
 645         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 646             attr == OVS_KEY_ATTR_CT_LABELS) {
 647                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 648
 649                 return ovs_net->xt_label;
 650         }
 651
 652         return false;
 653 }
 654
 655 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 656                        const struct sw_flow_key *key,
 657                        struct sw_flow_actions **sfa,  bool log)
 658 {
 659         struct ovs_conntrack_info ct_info;
 660         const char *helper = NULL;
 661         u16 family;
 662         int err;
 663
 664         family = key_to_nfproto(key);
 665         if (family == NFPROTO_UNSPEC) {
 666                 OVS_NLERR(log, "ct family unspecified");
 667                 return -EINVAL;
 668         }
 669
 670         memset(&ct_info, 0, sizeof(ct_info));
 671         ct_info.family = family;
 672
 673         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
 674                         NF_CT_DEFAULT_ZONE_DIR, 0);
 675
 676         err = parse_ct(attr, &ct_info, &helper, log);
 677         if (err)
 678                 return err;
 679
 680         /* Set up template for tracking connections in specific zones. */
 681         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
 682         if (!ct_info.ct) {
 683                 OVS_NLERR(log, "Failed to allocate conntrack template");
 684                 return -ENOMEM;
 685         }
 686
 687         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
 688         nf_conntrack_get(&ct_info.ct->ct_general);
 689
 690         if (helper) {
 691                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
 692                 if (err)
 693                         goto err_free_ct;
 694         }
 695
 696         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
 697                                  sizeof(ct_info), log);
 698         if (err)
 699                 goto err_free_ct;
 700
 701         return 0;
 702 err_free_ct:
 703         __ovs_ct_free_action(&ct_info);
 704         return err;
 705 }
 706
 707 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
 708                           struct sk_buff *skb)
 709 {
 710         struct nlattr *start;
 711
 712         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
 713         if (!start)
 714                 return -EMSGSIZE;
 715
 716         if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
 717                 return -EMSGSIZE;
 718         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 719             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
 720                 return -EMSGSIZE;
 721         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
 722             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
 723                     &ct_info->mark))
 724                 return -EMSGSIZE;
 725         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 726             labels_nonzero(&ct_info->labels.mask) &&
 727             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
 728                     &ct_info->labels))
 729                 return -EMSGSIZE;
 730         if (ct_info->helper) {
 731                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
 732                                    ct_info->helper->name))
 733                         return -EMSGSIZE;
 734         }
 735
 736         nla_nest_end(skb, start);
 737
 738         return 0;
 739 }
 740
 741 void ovs_ct_free_action(const struct nlattr *a)
 742 {
 743         struct ovs_conntrack_info *ct_info = nla_data(a);
 744
 745         __ovs_ct_free_action(ct_info);
 746 }
 747
 748 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
 749 {
 750         if (ct_info->helper)
 751                 module_put(ct_info->helper->me);
 752         if (ct_info->ct)
 753                 nf_ct_put(ct_info->ct);
 754 }
 755
 756 void ovs_ct_init(struct net *net)
 757 {
 758         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
 759         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 760
 761         if (nf_connlabels_get(net, n_bits)) {
 762                 ovs_net->xt_label = false;
 763                 OVS_NLERR(true, "Failed to set connlabel length");
 764         } else {
 765                 ovs_net->xt_label = true;
 766         }
 767 }
 768
 769 void ovs_ct_exit(struct net *net)
 770 {
 771         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 772
 773         if (ovs_net->xt_label)
 774                 nf_connlabels_put(net);
 775 }