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         if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS))
 228                 return -ENOTSUPP;
 229
 230         /* The connection could be invalid, in which case set_label is no-op.*/
 231         ct = nf_ct_get(skb, &ctinfo);
 232         if (!ct)
 233                 return 0;
 234
 235         cl = nf_ct_labels_find(ct);
 236         if (!cl) {
 237                 nf_ct_labels_ext_add(ct);
 238                 cl = nf_ct_labels_find(ct);
 239         }
 240         if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
 241                 return -ENOSPC;
 242
 243         err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
 244                                     OVS_CT_LABELS_LEN / sizeof(u32));
 245         if (err)
 246                 return err;
 247
 248         ovs_ct_get_labels(ct, &key->ct.labels);
 249         return 0;
 250 }
 251
 252 /* 'skb' should already be pulled to nh_ofs. */
 253 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 254 {
 255         const struct nf_conntrack_helper *helper;
 256         const struct nf_conn_help *help;
 257         enum ip_conntrack_info ctinfo;
 258         unsigned int protoff;
 259         struct nf_conn *ct;
 260
 261         ct = nf_ct_get(skb, &ctinfo);
 262         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 263                 return NF_ACCEPT;
 264
 265         help = nfct_help(ct);
 266         if (!help)
 267                 return NF_ACCEPT;
 268
 269         helper = rcu_dereference(help->helper);
 270         if (!helper)
 271                 return NF_ACCEPT;
 272
 273         switch (proto) {
 274         case NFPROTO_IPV4:
 275                 protoff = ip_hdrlen(skb);
 276                 break;
 277         case NFPROTO_IPV6: {
 278                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 279                 __be16 frag_off;
 280                 int ofs;
 281
 282                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 283                                        &frag_off);
 284                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 285                         pr_debug("proto header not found\n");
 286                         return NF_ACCEPT;
 287                 }
 288                 protoff = ofs;
 289                 break;
 290         }
 291         default:
 292                 WARN_ONCE(1, "helper invoked on non-IP family!");
 293                 return NF_DROP;
 294         }
 295
 296         return helper->help(skb, protoff, ct, ctinfo);
 297 }
 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         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 315 #if IS_ENABLED(CONFIG_NF_DEFRAG_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                         return -EINVAL;
 326
 327                 key->ip.proto = ipv6_hdr(reasm)->nexthdr;
 328                 skb_morph(skb, reasm);
 329                 consume_skb(reasm);
 330                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 331 #else
 332                 return -EPFNOSUPPORT;
 333 #endif
 334         } else {
 335                 return -EPFNOSUPPORT;
 336         }
 337
 338         key->ip.frag = OVS_FRAG_TYPE_NONE;
 339         skb_clear_hash(skb);
 340         skb->ignore_df = 1;
 341         *OVS_CB(skb) = ovs_cb;
 342
 343         return 0;
 344 }
 345
 346 static struct nf_conntrack_expect *
 347 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 348                    u16 proto, const struct sk_buff *skb)
 349 {
 350         struct nf_conntrack_tuple tuple;
 351
 352         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, &tuple))
 353                 return NULL;
 354         return __nf_ct_expect_find(net, zone, &tuple);
 355 }
 356
 357 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
 358 static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
 359                             const struct ovs_conntrack_info *info)
 360 {
 361         enum ip_conntrack_info ctinfo;
 362         struct nf_conn *ct;
 363
 364         ct = nf_ct_get(skb, &ctinfo);
 365         if (!ct)
 366                 return false;
 367         if (!net_eq(net, read_pnet(&ct->ct_net)))
 368                 return false;
 369         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 370                 return false;
 371         if (info->helper) {
 372                 struct nf_conn_help *help;
 373
 374                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 375                 if (help && rcu_access_pointer(help->helper) != info->helper)
 376                         return false;
 377         }
 378
 379         return true;
 380 }
 381
 382 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 383                            const struct ovs_conntrack_info *info,
 384                            struct sk_buff *skb)
 385 {
 386         /* If we are recirculating packets to match on conntrack fields and
 387          * committing with a separate conntrack action,  then we don't need to
 388          * actually run the packet through conntrack twice unless it's for a
 389          * different zone.
 390          */
 391         if (!skb_nfct_cached(net, skb, info)) {
 392                 struct nf_conn *tmpl = info->ct;
 393
 394                 /* Associate skb with specified zone. */
 395                 if (tmpl) {
 396                         if (skb->nfct)
 397                                 nf_conntrack_put(skb->nfct);
 398                         nf_conntrack_get(&tmpl->ct_general);
 399                         skb->nfct = &tmpl->ct_general;
 400                         skb->nfctinfo = IP_CT_NEW;
 401                 }
 402
 403                 if (nf_conntrack_in(net, info->family, NF_INET_PRE_ROUTING,
 404                                     skb) != NF_ACCEPT)
 405                         return -ENOENT;
 406
 407                 if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 408                         WARN_ONCE(1, "helper rejected packet");
 409                         return -EINVAL;
 410                 }
 411         }
 412
 413         ovs_ct_update_key(skb, key, true);
 414
 415         return 0;
 416 }
 417
 418 /* Lookup connection and read fields into key. */
 419 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 420                          const struct ovs_conntrack_info *info,
 421                          struct sk_buff *skb)
 422 {
 423         struct nf_conntrack_expect *exp;
 424
 425         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 426         if (exp) {
 427                 u8 state;
 428
 429                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 430                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 431         } else {
 432                 int err;
 433
 434                 err = __ovs_ct_lookup(net, key, info, skb);
 435                 if (err)
 436                         return err;
 437         }
 438
 439         return 0;
 440 }
 441
 442 /* Lookup connection and confirm if unconfirmed. */
 443 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
 444                          const struct ovs_conntrack_info *info,
 445                          struct sk_buff *skb)
 446 {
 447         u8 state;
 448         int err;
 449
 450         state = key->ct.state;
 451         if (key->ct.zone == info->zone.id &&
 452             ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
 453                 /* Previous lookup has shown that this connection is already
 454                  * tracked and committed. Skip committing.
 455                  */
 456                 return 0;
 457         }
 458
 459         err = __ovs_ct_lookup(net, key, info, skb);
 460         if (err)
 461                 return err;
 462         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
 463                 return -EINVAL;
 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 }