datapath/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/kconfig.h>
  15 #include <linux/version.h>
  16
  17 #if LINUX_VERSION_CODE > KERNEL_VERSION(3,9,0) && \
  18     IS_ENABLED(CONFIG_NF_CONNTRACK)
  19
  20 #include <linux/module.h>
  21 #include <linux/openvswitch.h>
  22 #include <net/ip.h>
  23 #include <net/netfilter/nf_conntrack_core.h>
  24 #include <net/netfilter/nf_conntrack_helper.h>
  25 #include <net/netfilter/nf_conntrack_labels.h>
  26 #include <net/netfilter/nf_conntrack_zones.h>
  27 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  28
  29 #include "datapath.h"
  30 #include "conntrack.h"
  31 #include "flow.h"
  32 #include "flow_netlink.h"
  33
  34 struct ovs_ct_len_tbl {
  35         size_t maxlen;
  36         size_t minlen;
  37 };
  38
  39 /* Metadata mark for masked write to conntrack mark */
  40 struct md_mark {
  41         u32 value;
  42         u32 mask;
  43 };
  44
  45 /* Metadata label for masked write to conntrack label. */
  46 struct md_labels {
  47         struct ovs_key_ct_labels value;
  48         struct ovs_key_ct_labels mask;
  49 };
  50
  51 /* Conntrack action context for execution. */
  52 struct ovs_conntrack_info {
  53         struct nf_conntrack_helper *helper;
  54         struct nf_conntrack_zone zone;
  55         struct nf_conn *ct;
  56         u8 commit : 1;
  57         u16 family;
  58         struct md_mark mark;
  59         struct md_labels labels;
  60 };
  61
  62 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
  63
  64 static u16 key_to_nfproto(const struct sw_flow_key *key)
  65 {
  66         switch (ntohs(key->eth.type)) {
  67         case ETH_P_IP:
  68                 return NFPROTO_IPV4;
  69         case ETH_P_IPV6:
  70                 return NFPROTO_IPV6;
  71         default:
  72                 return NFPROTO_UNSPEC;
  73         }
  74 }
  75
  76 /* Map SKB connection state into the values used by flow definition. */
  77 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
  78 {
  79         u8 ct_state = OVS_CS_F_TRACKED;
  80
  81         switch (ctinfo) {
  82         case IP_CT_ESTABLISHED_REPLY:
  83         case IP_CT_RELATED_REPLY:
  84         case IP_CT_NEW_REPLY:
  85                 ct_state |= OVS_CS_F_REPLY_DIR;
  86                 break;
  87         default:
  88                 break;
  89         }
  90
  91         switch (ctinfo) {
  92         case IP_CT_ESTABLISHED:
  93         case IP_CT_ESTABLISHED_REPLY:
  94                 ct_state |= OVS_CS_F_ESTABLISHED;
  95                 break;
  96         case IP_CT_RELATED:
  97         case IP_CT_RELATED_REPLY:
  98                 ct_state |= OVS_CS_F_RELATED;
  99                 break;
 100         case IP_CT_NEW:
 101         case IP_CT_NEW_REPLY:
 102                 ct_state |= OVS_CS_F_NEW;
 103                 break;
 104         default:
 105                 break;
 106         }
 107
 108         return ct_state;
 109 }
 110
 111 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
 112 {
 113 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 114         return ct ? ct->mark : 0;
 115 #else
 116         return 0;
 117 #endif
 118 }
 119
 120 static void ovs_ct_get_labels(const struct nf_conn *ct,
 121                               struct ovs_key_ct_labels *labels)
 122 {
 123         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
 124
 125         if (cl) {
 126                 size_t len = cl->words * sizeof(long);
 127
 128                 if (len > OVS_CT_LABELS_LEN)
 129                         len = OVS_CT_LABELS_LEN;
 130                 else if (len < OVS_CT_LABELS_LEN)
 131                         memset(labels, 0, OVS_CT_LABELS_LEN);
 132                 memcpy(labels, cl->bits, len);
 133         } else {
 134                 memset(labels, 0, OVS_CT_LABELS_LEN);
 135         }
 136 }
 137
 138 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
 139                                 const struct nf_conntrack_zone *zone,
 140                                 const struct nf_conn *ct)
 141 {
 142         key->ct.state = state;
 143         key->ct.zone = zone->id;
 144         key->ct.mark = ovs_ct_get_mark(ct);
 145         ovs_ct_get_labels(ct, &key->ct.labels);
 146 }
 147
 148 /* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
 149  * previously sent the packet to conntrack via the ct action.
 150  */
 151 static void ovs_ct_update_key(const struct sk_buff *skb,
 152                               struct sw_flow_key *key, bool post_ct)
 153 {
 154         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 155         enum ip_conntrack_info ctinfo;
 156         struct nf_conn *ct;
 157         u8 state = 0;
 158
 159         ct = nf_ct_get(skb, &ctinfo);
 160         if (ct) {
 161                 state = ovs_ct_get_state(ctinfo);
 162                 if (!nf_ct_is_confirmed(ct))
 163                         state |= OVS_CS_F_NEW;
 164                 if (ct->master)
 165                         state |= OVS_CS_F_RELATED;
 166                 zone = nf_ct_zone(ct);
 167         } else if (post_ct) {
 168                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 169         }
 170         __ovs_ct_update_key(key, state, zone, ct);
 171 }
 172
 173 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 174 {
 175         ovs_ct_update_key(skb, key, false);
 176 }
 177
 178 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 179 {
 180         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 181                 return -EMSGSIZE;
 182
 183         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 184             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 185                 return -EMSGSIZE;
 186
 187         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 188             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 189                 return -EMSGSIZE;
 190
 191         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 192             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
 193                     &key->ct.labels))
 194                 return -EMSGSIZE;
 195
 196         return 0;
 197 }
 198
 199 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 200                            u32 ct_mark, u32 mask)
 201 {
 202 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 203         enum ip_conntrack_info ctinfo;
 204         struct nf_conn *ct;
 205         u32 new_mark;
 206
 207
 208         /* The connection could be invalid, in which case set_mark is no-op. */
 209         ct = nf_ct_get(skb, &ctinfo);
 210         if (!ct)
 211                 return 0;
 212
 213         new_mark = ct_mark | (ct->mark & ~(mask));
 214         if (ct->mark != new_mark) {
 215                 ct->mark = new_mark;
 216                 nf_conntrack_event_cache(IPCT_MARK, ct);
 217                 key->ct.mark = new_mark;
 218         }
 219
 220         return 0;
 221 #else
 222         return -ENOTSUPP;
 223 #endif
 224 }
 225
 226 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
 227                              const struct ovs_key_ct_labels *labels,
 228                              const struct ovs_key_ct_labels *mask)
 229 {
 230         enum ip_conntrack_info ctinfo;
 231         struct nf_conn_labels *cl;
 232         struct nf_conn *ct;
 233         int err;
 234
 235         /* The connection could be invalid, in which case set_label is no-op.*/
 236         ct = nf_ct_get(skb, &ctinfo);
 237         if (!ct)
 238                 return 0;
 239
 240         cl = nf_ct_labels_find(ct);
 241         if (!cl) {
 242                 nf_ct_labels_ext_add(ct);
 243                 cl = nf_ct_labels_find(ct);
 244         }
 245         if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
 246                 return -ENOSPC;
 247
 248         err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
 249                                     OVS_CT_LABELS_LEN / sizeof(u32));
 250         if (err)
 251                 return err;
 252
 253         ovs_ct_get_labels(ct, &key->ct.labels);
 254         return 0;
 255 }
 256
 257 /* 'skb' should already be pulled to nh_ofs. */
 258 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 259 {
 260         const struct nf_conntrack_helper *helper;
 261         const struct nf_conn_help *help;
 262         enum ip_conntrack_info ctinfo;
 263         unsigned int protoff;
 264         struct nf_conn *ct;
 265
 266         ct = nf_ct_get(skb, &ctinfo);
 267         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 268                 return NF_ACCEPT;
 269
 270         help = nfct_help(ct);
 271         if (!help)
 272                 return NF_ACCEPT;
 273
 274         helper = rcu_dereference(help->helper);
 275         if (!helper)
 276                 return NF_ACCEPT;
 277
 278         switch (proto) {
 279         case NFPROTO_IPV4:
 280                 protoff = ip_hdrlen(skb);
 281                 break;
 282         case NFPROTO_IPV6: {
 283                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 284                 __be16 frag_off;
 285                 int ofs;
 286
 287                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 288                                        &frag_off);
 289                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 290                         pr_debug("proto header not found\n");
 291                         return NF_ACCEPT;
 292                 }
 293                 protoff = ofs;
 294                 break;
 295         }
 296         default:
 297                 WARN_ONCE(1, "helper invoked on non-IP family!");
 298                 return NF_DROP;
 299         }
 300
 301         return helper->help(skb, protoff, ct, ctinfo);
 302 }
 303
 304 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 305  * value if 'skb' is freed.
 306  */
 307 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 308                             u16 zone, struct sk_buff *skb)
 309 {
 310         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 311
 312         if (!skb->dev) {
 313                 OVS_NLERR(true, "%s: skb has no dev; dropping", __func__);
 314                 return -EINVAL;
 315         }
 316
 317         if (key->eth.type == htons(ETH_P_IP)) {
 318                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 319                 int err;
 320
 321                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 322                 err = ip_defrag(skb, user);
 323                 if (err)
 324                         return err;
 325
 326                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 327 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 328         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 329                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 330                 struct sk_buff *reasm;
 331
 332                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 333                 reasm = nf_ct_frag6_gather(skb, user);
 334                 if (!reasm)
 335                         return -EINPROGRESS;
 336
 337                 if (skb == reasm) {
 338                         kfree_skb(skb);
 339                         return -EINVAL;
 340                 }
 341
 342                 /* Don't free 'skb' even though it is one of the original
 343                  * fragments, as we're going to morph it into the head.
 344                  */
 345                 skb_get(skb);
 346                 nf_ct_frag6_consume_orig(reasm);
 347
 348                 key->ip.proto = ipv6_hdr(reasm)->nexthdr;
 349                 skb_morph(skb, reasm);
 350                 skb->next = reasm->next;
 351                 consume_skb(reasm);
 352                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 353 #endif /* IP frag support */
 354         } else {
 355                 kfree_skb(skb);
 356                 return -EPFNOSUPPORT;
 357         }
 358
 359         key->ip.frag = OVS_FRAG_TYPE_NONE;
 360         skb_clear_hash(skb);
 361         skb->ignore_df = 1;
 362         *OVS_CB(skb) = ovs_cb;
 363
 364         return 0;
 365 }
 366
 367 static struct nf_conntrack_expect *
 368 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 369                    u16 proto, const struct sk_buff *skb)
 370 {
 371         struct nf_conntrack_tuple tuple;
 372
 373         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, &tuple))
 374                 return NULL;
 375         return __nf_ct_expect_find(net, zone, &tuple);
 376 }
 377
 378 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
 379 static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
 380                             const struct ovs_conntrack_info *info)
 381 {
 382         enum ip_conntrack_info ctinfo;
 383         struct nf_conn *ct;
 384
 385         ct = nf_ct_get(skb, &ctinfo);
 386         if (!ct)
 387                 return false;
 388         if (!net_eq(net, read_pnet(&ct->ct_net)))
 389                 return false;
 390         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 391                 return false;
 392         if (info->helper) {
 393                 struct nf_conn_help *help;
 394
 395                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 396                 if (help && rcu_access_pointer(help->helper) != info->helper)
 397                         return false;
 398         }
 399
 400         return true;
 401 }
 402
 403 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 404                            const struct ovs_conntrack_info *info,
 405                            struct sk_buff *skb)
 406 {
 407         /* If we are recirculating packets to match on conntrack fields and
 408          * committing with a separate conntrack action,  then we don't need to
 409          * actually run the packet through conntrack twice unless it's for a
 410          * different zone.
 411          */
 412         if (!skb_nfct_cached(net, skb, info)) {
 413                 struct nf_conn *tmpl = info->ct;
 414
 415                 /* Associate skb with specified zone. */
 416                 if (tmpl) {
 417                         if (skb->nfct)
 418                                 nf_conntrack_put(skb->nfct);
 419                         nf_conntrack_get(&tmpl->ct_general);
 420                         skb->nfct = &tmpl->ct_general;
 421                         skb->nfctinfo = IP_CT_NEW;
 422                 }
 423
 424                 if (nf_conntrack_in(net, info->family, NF_INET_FORWARD,
 425                                     skb) != NF_ACCEPT)
 426                         return -ENOENT;
 427
 428                 if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 429                         WARN_ONCE(1, "helper rejected packet");
 430                         return -EINVAL;
 431                 }
 432         }
 433
 434         ovs_ct_update_key(skb, key, true);
 435
 436         return 0;
 437 }
 438
 439 /* Lookup connection and read fields into key. */
 440 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 441                          const struct ovs_conntrack_info *info,
 442                          struct sk_buff *skb)
 443 {
 444         struct nf_conntrack_expect *exp;
 445
 446         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 447         if (exp) {
 448                 u8 state;
 449
 450                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 451                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 452         } else {
 453                 int err;
 454
 455                 err = __ovs_ct_lookup(net, key, info, skb);
 456                 if (err)
 457                         return err;
 458         }
 459
 460         return 0;
 461 }
 462
 463 /* Lookup connection and confirm if unconfirmed. */
 464 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
 465                          const struct ovs_conntrack_info *info,
 466                          struct sk_buff *skb)
 467 {
 468         u8 state;
 469         int err;
 470
 471         state = key->ct.state;
 472         if (key->ct.zone == info->zone.id &&
 473             ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
 474                 /* Previous lookup has shown that this connection is already
 475                  * tracked and committed. Skip committing.
 476                  */
 477                 return 0;
 478         }
 479
 480         err = __ovs_ct_lookup(net, key, info, skb);
 481         if (err)
 482                 return err;
 483         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
 484                 return -EINVAL;
 485
 486         return 0;
 487 }
 488
 489 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
 490 {
 491         size_t i;
 492
 493         for (i = 0; i < sizeof(*labels); i++)
 494                 if (labels->ct_labels[i])
 495                         return true;
 496
 497         return false;
 498 }
 499
 500 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 501  * value if 'skb' is freed.
 502  */
 503 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 504                    struct sw_flow_key *key,
 505                    const struct ovs_conntrack_info *info)
 506 {
 507         int nh_ofs;
 508         int err;
 509
 510         /* The conntrack module expects to be working at L3. */
 511         nh_ofs = skb_network_offset(skb);
 512         skb_pull(skb, nh_ofs);
 513
 514         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 515                 err = handle_fragments(net, key, info->zone.id, skb);
 516                 if (err)
 517                         return err;
 518         }
 519
 520         if (info->commit)
 521                 err = ovs_ct_commit(net, key, info, skb);
 522         else
 523                 err = ovs_ct_lookup(net, key, info, skb);
 524         if (err)
 525                 goto err;
 526
 527         if (info->mark.mask) {
 528                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 529                                       info->mark.mask);
 530                 if (err)
 531                         goto err;
 532         }
 533         if (labels_nonzero(&info->labels.mask))
 534                 err = ovs_ct_set_labels(skb, key, &info->labels.value,
 535                                         &info->labels.mask);
 536 err:
 537         skb_push(skb, nh_ofs);
 538         if (err)
 539                 kfree_skb(skb);
 540         return err;
 541 }
 542
 543 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 544                              const struct sw_flow_key *key, bool log)
 545 {
 546         struct nf_conntrack_helper *helper;
 547         struct nf_conn_help *help;
 548
 549         helper = nf_conntrack_helper_try_module_get(name, info->family,
 550                                                     key->ip.proto);
 551         if (!helper) {
 552                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 553                 return -EINVAL;
 554         }
 555
 556         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 557         if (!help) {
 558                 module_put(helper->me);
 559                 return -ENOMEM;
 560         }
 561
 562         rcu_assign_pointer(help->helper, helper);
 563         info->helper = helper;
 564         return 0;
 565 }
 566
 567 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
 568         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
 569         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
 570                                     .maxlen = sizeof(u16) },
 571         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
 572                                     .maxlen = sizeof(struct md_mark) },
 573         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
 574                                     .maxlen = sizeof(struct md_labels) },
 575         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
 576                                     .maxlen = NF_CT_HELPER_NAME_LEN }
 577 };
 578
 579 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
 580                     const char **helper, bool log)
 581 {
 582         struct nlattr *a;
 583         int rem;
 584
 585         nla_for_each_nested(a, attr, rem) {
 586                 int type = nla_type(a);
 587                 int maxlen = ovs_ct_attr_lens[type].maxlen;
 588                 int minlen = ovs_ct_attr_lens[type].minlen;
 589
 590                 if (type > OVS_CT_ATTR_MAX) {
 591                         OVS_NLERR(log,
 592                                   "Unknown conntrack attr (type=%d, max=%d)",
 593                                   type, OVS_CT_ATTR_MAX);
 594                         return -EINVAL;
 595                 }
 596                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
 597                         OVS_NLERR(log,
 598                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
 599                                   type, nla_len(a), maxlen);
 600                         return -EINVAL;
 601                 }
 602
 603                 switch (type) {
 604                 case OVS_CT_ATTR_COMMIT:
 605                         info->commit = true;
 606                         break;
 607 #ifdef CONFIG_NF_CONNTRACK_ZONES
 608                 case OVS_CT_ATTR_ZONE:
 609                         info->zone.id = nla_get_u16(a);
 610                         break;
 611 #endif
 612 #ifdef CONFIG_NF_CONNTRACK_MARK
 613                 case OVS_CT_ATTR_MARK: {
 614                         struct md_mark *mark = nla_data(a);
 615
 616                         if (!mark->mask) {
 617                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
 618                                 return -EINVAL;
 619                         }
 620                         info->mark = *mark;
 621                         break;
 622                 }
 623 #endif
 624 #ifdef CONFIG_NF_CONNTRACK_LABELS
 625                 case OVS_CT_ATTR_LABELS: {
 626                         struct md_labels *labels = nla_data(a);
 627
 628                         if (!labels_nonzero(&labels->mask)) {
 629                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
 630                                 return -EINVAL;
 631                         }
 632                         info->labels = *labels;
 633                         break;
 634                 }
 635 #endif
 636                 case OVS_CT_ATTR_HELPER:
 637                         *helper = nla_data(a);
 638                         if (!memchr(*helper, '\0', nla_len(a))) {
 639                                 OVS_NLERR(log, "Invalid conntrack helper");
 640                                 return -EINVAL;
 641                         }
 642                         break;
 643                 default:
 644                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
 645                                   type);
 646                         return -EINVAL;
 647                 }
 648         }
 649
 650         if (rem > 0) {
 651                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
 652                 return -EINVAL;
 653         }
 654
 655         return 0;
 656 }
 657
 658 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
 659 {
 660         if (attr == OVS_KEY_ATTR_CT_STATE)
 661                 return true;
 662         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 663             attr == OVS_KEY_ATTR_CT_ZONE)
 664                 return true;
 665         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 666             attr == OVS_KEY_ATTR_CT_MARK)
 667                 return true;
 668         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 669             attr == OVS_KEY_ATTR_CT_LABELS) {
 670                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 671
 672                 return ovs_net->xt_label;
 673         }
 674
 675         return false;
 676 }
 677
 678 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 679                        const struct sw_flow_key *key,
 680                        struct sw_flow_actions **sfa,  bool log)
 681 {
 682         struct ovs_conntrack_info ct_info;
 683         const char *helper = NULL;
 684         u16 family;
 685         int err;
 686
 687         family = key_to_nfproto(key);
 688         if (family == NFPROTO_UNSPEC) {
 689                 OVS_NLERR(log, "ct family unspecified");
 690                 return -EINVAL;
 691         }
 692
 693         memset(&ct_info, 0, sizeof(ct_info));
 694         ct_info.family = family;
 695
 696         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
 697                         NF_CT_DEFAULT_ZONE_DIR, 0);
 698
 699         err = parse_ct(attr, &ct_info, &helper, log);
 700         if (err)
 701                 return err;
 702
 703         /* Set up template for tracking connections in specific zones. */
 704         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
 705         if (!ct_info.ct) {
 706                 OVS_NLERR(log, "Failed to allocate conntrack template");
 707                 return -ENOMEM;
 708         }
 709         if (helper) {
 710                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
 711                 if (err)
 712                         goto err_free_ct;
 713         }
 714
 715         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
 716                                  sizeof(ct_info), log);
 717         if (err)
 718                 goto err_free_ct;
 719
 720         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
 721         nf_conntrack_get(&ct_info.ct->ct_general);
 722         return 0;
 723 err_free_ct:
 724         __ovs_ct_free_action(&ct_info);
 725         return err;
 726 }
 727
 728 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
 729                           struct sk_buff *skb)
 730 {
 731         struct nlattr *start;
 732
 733         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
 734         if (!start)
 735                 return -EMSGSIZE;
 736
 737         if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
 738                 return -EMSGSIZE;
 739         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 740             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
 741                 return -EMSGSIZE;
 742         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
 743             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
 744                     &ct_info->mark))
 745                 return -EMSGSIZE;
 746         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 747             labels_nonzero(&ct_info->labels.mask) &&
 748             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
 749                     &ct_info->labels))
 750                 return -EMSGSIZE;
 751         if (ct_info->helper) {
 752                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
 753                                    ct_info->helper->name))
 754                         return -EMSGSIZE;
 755         }
 756
 757         nla_nest_end(skb, start);
 758
 759         return 0;
 760 }
 761
 762 void ovs_ct_free_action(const struct nlattr *a)
 763 {
 764         struct ovs_conntrack_info *ct_info = nla_data(a);
 765
 766         __ovs_ct_free_action(ct_info);
 767 }
 768
 769 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
 770 {
 771         if (ct_info->helper)
 772                 module_put(ct_info->helper->me);
 773         if (ct_info->ct)
 774                 nf_ct_tmpl_free(ct_info->ct);
 775 }
 776
 777 void ovs_ct_init(struct net *net)
 778 {
 779         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
 780         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 781
 782         if (nf_connlabels_get(net, n_bits)) {
 783                 ovs_net->xt_label = false;
 784                 OVS_NLERR(true, "Failed to set connlabel length");
 785         } else {
 786                 ovs_net->xt_label = true;
 787         }
 788 }
 789
 790 void ovs_ct_exit(struct net *net)
 791 {
 792         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 793
 794         if (ovs_net->xt_label)
 795                 nf_connlabels_put(net);
 796 }
 797
 798 #endif /* CONFIG_NF_CONNTRACK && LINUX > 3.9 */