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 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_label(const struct nf_conn *ct,
 113                              struct ovs_key_ct_label *label)
 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_LABEL_LEN)
 121                         len = OVS_CT_LABEL_LEN;
 122                 else if (len < OVS_CT_LABEL_LEN)
 123                         memset(label, 0, OVS_CT_LABEL_LEN);
 124                 memcpy(label, cl->bits, len);
 125         } else {
 126                 memset(label, 0, OVS_CT_LABEL_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_label(ct, &key->ct.label);
 138 }
 139
 140 /* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
 141  * previously sent the packet to conntrack via the ct action.
 142  */
 143 static void ovs_ct_update_key(const struct sk_buff *skb,
 144                               struct sw_flow_key *key, bool post_ct)
 145 {
 146         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 147         enum ip_conntrack_info ctinfo;
 148         struct nf_conn *ct;
 149         u8 state = 0;
 150
 151         ct = nf_ct_get(skb, &ctinfo);
 152         if (ct) {
 153                 state = ovs_ct_get_state(ctinfo);
 154                 if (ct->master)
 155                         state |= OVS_CS_F_RELATED;
 156                 zone = nf_ct_zone(ct);
 157         } else if (post_ct) {
 158                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 159         }
 160         __ovs_ct_update_key(key, state, zone, ct);
 161 }
 162
 163 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 164 {
 165         ovs_ct_update_key(skb, key, false);
 166 }
 167
 168 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 169 {
 170         if (nla_put_u8(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 171                 return -EMSGSIZE;
 172
 173         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 174             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 175                 return -EMSGSIZE;
 176
 177         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 178             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 179                 return -EMSGSIZE;
 180
 181         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 182             nla_put(skb, OVS_KEY_ATTR_CT_LABEL, sizeof(key->ct.label),
 183                     &key->ct.label))
 184                 return -EMSGSIZE;
 185
 186         return 0;
 187 }
 188
 189 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 190                            u32 ct_mark, u32 mask)
 191 {
 192 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 193         enum ip_conntrack_info ctinfo;
 194         struct nf_conn *ct;
 195         u32 new_mark;
 196
 197
 198         /* The connection could be invalid, in which case set_mark is no-op. */
 199         ct = nf_ct_get(skb, &ctinfo);
 200         if (!ct)
 201                 return 0;
 202
 203         new_mark = ct_mark | (ct->mark & ~(mask));
 204         if (ct->mark != new_mark) {
 205                 ct->mark = new_mark;
 206                 nf_conntrack_event_cache(IPCT_MARK, ct);
 207                 key->ct.mark = new_mark;
 208         }
 209
 210         return 0;
 211 #else
 212         return -ENOTSUPP;
 213 #endif
 214 }
 215
 216 static int ovs_ct_set_label(struct sk_buff *skb, struct sw_flow_key *key,
 217                             const struct ovs_key_ct_label *label,
 218                             const struct ovs_key_ct_label *mask)
 219 {
 220         enum ip_conntrack_info ctinfo;
 221         struct nf_conn_labels *cl;
 222         struct nf_conn *ct;
 223         int err;
 224
 225         if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS))
 226                 return -ENOTSUPP;
 227
 228         /* The connection could be invalid, in which case set_label is no-op.*/
 229         ct = nf_ct_get(skb, &ctinfo);
 230         if (!ct)
 231                 return 0;
 232
 233         cl = nf_ct_labels_find(ct);
 234         if (!cl) {
 235                 nf_ct_labels_ext_add(ct);
 236                 cl = nf_ct_labels_find(ct);
 237         }
 238         if (!cl || cl->words * sizeof(long) < OVS_CT_LABEL_LEN)
 239                 return -ENOSPC;
 240
 241         err = nf_connlabels_replace(ct, (u32 *)label, (u32 *)mask,
 242                                     OVS_CT_LABEL_LEN / sizeof(u32));
 243         if (err)
 244                 return err;
 245
 246         ovs_ct_get_label(ct, &key->ct.label);
 247         return 0;
 248 }
 249
 250 /* 'skb' should already be pulled to nh_ofs. */
 251 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 252 {
 253         const struct nf_conntrack_helper *helper;
 254         const struct nf_conn_help *help;
 255         enum ip_conntrack_info ctinfo;
 256         unsigned int protoff;
 257         struct nf_conn *ct;
 258
 259         ct = nf_ct_get(skb, &ctinfo);
 260         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 261                 return NF_ACCEPT;
 262
 263         help = nfct_help(ct);
 264         if (!help)
 265                 return NF_ACCEPT;
 266
 267         helper = rcu_dereference(help->helper);
 268         if (!helper)
 269                 return NF_ACCEPT;
 270
 271         switch (proto) {
 272         case NFPROTO_IPV4:
 273                 protoff = ip_hdrlen(skb);
 274                 break;
 275         case NFPROTO_IPV6: {
 276                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 277                 __be16 frag_off;
 278
 279                 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
 280                                            &nexthdr, &frag_off);
 281                 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
 282                         pr_debug("proto header not found\n");
 283                         return NF_ACCEPT;
 284                 }
 285                 break;
 286         }
 287         default:
 288                 WARN_ONCE(1, "helper invoked on non-IP family!");
 289                 return NF_DROP;
 290         }
 291
 292         return helper->help(skb, protoff, ct, ctinfo);
 293 }
 294
 295 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 296                             u16 zone, struct sk_buff *skb)
 297 {
 298         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 299
 300         if (key->eth.type == htons(ETH_P_IP)) {
 301                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 302                 int err;
 303
 304                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 305                 err = ip_defrag(skb, user);
 306                 if (err)
 307                         return err;
 308
 309                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 310         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 311 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 312                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 313                 struct sk_buff *reasm;
 314
 315                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 316                 reasm = nf_ct_frag6_gather(skb, user);
 317                 if (!reasm)
 318                         return -EINPROGRESS;
 319
 320                 if (skb == reasm)
 321                         return -EINVAL;
 322
 323                 key->ip.proto = ipv6_hdr(reasm)->nexthdr;
 324                 skb_morph(skb, reasm);
 325                 consume_skb(reasm);
 326                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 327 #else
 328                 return -EPFNOSUPPORT;
 329 #endif
 330         } else {
 331                 return -EPFNOSUPPORT;
 332         }
 333
 334         key->ip.frag = OVS_FRAG_TYPE_NONE;
 335         skb_clear_hash(skb);
 336         skb->ignore_df = 1;
 337         *OVS_CB(skb) = ovs_cb;
 338
 339         return 0;
 340 }
 341
 342 static struct nf_conntrack_expect *
 343 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 344                    u16 proto, const struct sk_buff *skb)
 345 {
 346         struct nf_conntrack_tuple tuple;
 347
 348         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, &tuple))
 349                 return NULL;
 350         return __nf_ct_expect_find(net, zone, &tuple);
 351 }
 352
 353 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
 354 static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
 355                             const struct ovs_conntrack_info *info)
 356 {
 357         enum ip_conntrack_info ctinfo;
 358         struct nf_conn *ct;
 359
 360         ct = nf_ct_get(skb, &ctinfo);
 361         if (!ct)
 362                 return false;
 363         if (!net_eq(net, read_pnet(&ct->ct_net)))
 364                 return false;
 365         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 366                 return false;
 367         if (info->helper) {
 368                 struct nf_conn_help *help;
 369
 370                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 371                 if (help && rcu_access_pointer(help->helper) != info->helper)
 372                         return false;
 373         }
 374
 375         return true;
 376 }
 377
 378 static int __ovs_ct_lookup(struct net *net, const struct sw_flow_key *key,
 379                            const struct ovs_conntrack_info *info,
 380                            struct sk_buff *skb)
 381 {
 382         /* If we are recirculating packets to match on conntrack fields and
 383          * committing with a separate conntrack action,  then we don't need to
 384          * actually run the packet through conntrack twice unless it's for a
 385          * different zone.
 386          */
 387         if (!skb_nfct_cached(net, skb, info)) {
 388                 struct nf_conn *tmpl = info->ct;
 389
 390                 /* Associate skb with specified zone. */
 391                 if (tmpl) {
 392                         if (skb->nfct)
 393                                 nf_conntrack_put(skb->nfct);
 394                         nf_conntrack_get(&tmpl->ct_general);
 395                         skb->nfct = &tmpl->ct_general;
 396                         skb->nfctinfo = IP_CT_NEW;
 397                 }
 398
 399                 if (nf_conntrack_in(net, info->family, NF_INET_PRE_ROUTING,
 400                                     skb) != NF_ACCEPT)
 401                         return -ENOENT;
 402
 403                 if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 404                         WARN_ONCE(1, "helper rejected packet");
 405                         return -EINVAL;
 406                 }
 407         }
 408
 409         return 0;
 410 }
 411
 412 /* Lookup connection and read fields into key. */
 413 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 414                          const struct ovs_conntrack_info *info,
 415                          struct sk_buff *skb)
 416 {
 417         struct nf_conntrack_expect *exp;
 418
 419         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 420         if (exp) {
 421                 u8 state;
 422
 423                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 424                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 425         } else {
 426                 int err;
 427
 428                 err = __ovs_ct_lookup(net, key, info, skb);
 429                 if (err)
 430                         return err;
 431
 432                 ovs_ct_update_key(skb, key, true);
 433         }
 434
 435         return 0;
 436 }
 437
 438 /* Lookup connection and confirm if unconfirmed. */
 439 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
 440                          const struct ovs_conntrack_info *info,
 441                          struct sk_buff *skb)
 442 {
 443         u8 state;
 444         int err;
 445
 446         state = key->ct.state;
 447         if (key->ct.zone == info->zone.id &&
 448             ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
 449                 /* Previous lookup has shown that this connection is already
 450                  * tracked and committed. Skip committing.
 451                  */
 452                 return 0;
 453         }
 454
 455         err = __ovs_ct_lookup(net, key, info, skb);
 456         if (err)
 457                 return err;
 458         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
 459                 return -EINVAL;
 460
 461         ovs_ct_update_key(skb, key, true);
 462
 463         return 0;
 464 }
 465
 466 static bool label_nonzero(const struct ovs_key_ct_label *label)
 467 {
 468         size_t i;
 469
 470         for (i = 0; i < sizeof(*label); i++)
 471                 if (label->ct_label[i])
 472                         return true;
 473
 474         return false;
 475 }
 476
 477 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 478                    struct sw_flow_key *key,
 479                    const struct ovs_conntrack_info *info)
 480 {
 481         int nh_ofs;
 482         int err;
 483
 484         /* The conntrack module expects to be working at L3. */
 485         nh_ofs = skb_network_offset(skb);
 486         skb_pull(skb, nh_ofs);
 487
 488         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 489                 err = handle_fragments(net, key, info->zone.id, skb);
 490                 if (err)
 491                         return err;
 492         }
 493
 494         if (info->flags & OVS_CT_F_COMMIT)
 495                 err = ovs_ct_commit(net, key, info, skb);
 496         else
 497                 err = ovs_ct_lookup(net, key, info, skb);
 498         if (err)
 499                 goto err;
 500
 501         if (info->mark.mask) {
 502                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 503                                       info->mark.mask);
 504                 if (err)
 505                         goto err;
 506         }
 507         if (label_nonzero(&info->label.mask))
 508                 err = ovs_ct_set_label(skb, key, &info->label.value,
 509                                        &info->label.mask);
 510 err:
 511         skb_push(skb, nh_ofs);
 512         return err;
 513 }
 514
 515 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 516                              const struct sw_flow_key *key, bool log)
 517 {
 518         struct nf_conntrack_helper *helper;
 519         struct nf_conn_help *help;
 520
 521         helper = nf_conntrack_helper_try_module_get(name, info->family,
 522                                                     key->ip.proto);
 523         if (!helper) {
 524                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 525                 return -EINVAL;
 526         }
 527
 528         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 529         if (!help) {
 530                 module_put(helper->me);
 531                 return -ENOMEM;
 532         }
 533
 534         rcu_assign_pointer(help->helper, helper);
 535         info->helper = helper;
 536         return 0;
 537 }
 538
 539 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
 540         [OVS_CT_ATTR_FLAGS]     = { .minlen = sizeof(u32),
 541                                     .maxlen = sizeof(u32) },
 542         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
 543                                     .maxlen = sizeof(u16) },
 544         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
 545                                     .maxlen = sizeof(struct md_mark) },
 546         [OVS_CT_ATTR_LABEL]     = { .minlen = sizeof(struct md_label),
 547                                     .maxlen = sizeof(struct md_label) },
 548         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
 549                                     .maxlen = NF_CT_HELPER_NAME_LEN }
 550 };
 551
 552 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
 553                     const char **helper, bool log)
 554 {
 555         struct nlattr *a;
 556         int rem;
 557
 558         nla_for_each_nested(a, attr, rem) {
 559                 int type = nla_type(a);
 560                 int maxlen = ovs_ct_attr_lens[type].maxlen;
 561                 int minlen = ovs_ct_attr_lens[type].minlen;
 562
 563                 if (type > OVS_CT_ATTR_MAX) {
 564                         OVS_NLERR(log,
 565                                   "Unknown conntrack attr (type=%d, max=%d)",
 566                                   type, OVS_CT_ATTR_MAX);
 567                         return -EINVAL;
 568                 }
 569                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
 570                         OVS_NLERR(log,
 571                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
 572                                   type, nla_len(a), maxlen);
 573                         return -EINVAL;
 574                 }
 575
 576                 switch (type) {
 577                 case OVS_CT_ATTR_FLAGS:
 578                         info->flags = nla_get_u32(a);
 579                         break;
 580 #ifdef CONFIG_NF_CONNTRACK_ZONES
 581                 case OVS_CT_ATTR_ZONE:
 582                         info->zone.id = nla_get_u16(a);
 583                         break;
 584 #endif
 585 #ifdef CONFIG_NF_CONNTRACK_MARK
 586                 case OVS_CT_ATTR_MARK: {
 587                         struct md_mark *mark = nla_data(a);
 588
 589                         info->mark = *mark;
 590                         break;
 591                 }
 592 #endif
 593 #ifdef CONFIG_NF_CONNTRACK_LABELS
 594                 case OVS_CT_ATTR_LABEL: {
 595                         struct md_label *label = nla_data(a);
 596
 597                         info->label = *label;
 598                         break;
 599                 }
 600 #endif
 601                 case OVS_CT_ATTR_HELPER:
 602                         *helper = nla_data(a);
 603                         if (!memchr(*helper, '\0', nla_len(a))) {
 604                                 OVS_NLERR(log, "Invalid conntrack helper");
 605                                 return -EINVAL;
 606                         }
 607                         break;
 608                 default:
 609                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
 610                                   type);
 611                         return -EINVAL;
 612                 }
 613         }
 614
 615         if (rem > 0) {
 616                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
 617                 return -EINVAL;
 618         }
 619
 620         return 0;
 621 }
 622
 623 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
 624 {
 625         if (attr == OVS_KEY_ATTR_CT_STATE)
 626                 return true;
 627         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 628             attr == OVS_KEY_ATTR_CT_ZONE)
 629                 return true;
 630         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 631             attr == OVS_KEY_ATTR_CT_MARK)
 632                 return true;
 633         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 634             attr == OVS_KEY_ATTR_CT_LABEL) {
 635                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 636
 637                 return ovs_net->xt_label;
 638         }
 639
 640         return false;
 641 }
 642
 643 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 644                        const struct sw_flow_key *key,
 645                        struct sw_flow_actions **sfa,  bool log)
 646 {
 647         struct ovs_conntrack_info ct_info;
 648         const char *helper = NULL;
 649         u16 family;
 650         int err;
 651
 652         family = key_to_nfproto(key);
 653         if (family == NFPROTO_UNSPEC) {
 654                 OVS_NLERR(log, "ct family unspecified");
 655                 return -EINVAL;
 656         }
 657
 658         memset(&ct_info, 0, sizeof(ct_info));
 659         ct_info.family = family;
 660
 661         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
 662                         NF_CT_DEFAULT_ZONE_DIR, 0);
 663
 664         err = parse_ct(attr, &ct_info, &helper, log);
 665         if (err)
 666                 return err;
 667
 668         /* Set up template for tracking connections in specific zones. */
 669         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
 670         if (!ct_info.ct) {
 671                 OVS_NLERR(log, "Failed to allocate conntrack template");
 672                 return -ENOMEM;
 673         }
 674         if (helper) {
 675                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
 676                 if (err)
 677                         goto err_free_ct;
 678         }
 679
 680         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
 681                                  sizeof(ct_info), log);
 682         if (err)
 683                 goto err_free_ct;
 684
 685         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
 686         nf_conntrack_get(&ct_info.ct->ct_general);
 687         return 0;
 688 err_free_ct:
 689         nf_conntrack_free(ct_info.ct);
 690         return err;
 691 }
 692
 693 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
 694                           struct sk_buff *skb)
 695 {
 696         struct nlattr *start;
 697
 698         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
 699         if (!start)
 700                 return -EMSGSIZE;
 701
 702         if (nla_put_u32(skb, OVS_CT_ATTR_FLAGS, ct_info->flags))
 703                 return -EMSGSIZE;
 704         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 705             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
 706                 return -EMSGSIZE;
 707         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 708             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
 709                     &ct_info->mark))
 710                 return -EMSGSIZE;
 711         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 712             nla_put(skb, OVS_CT_ATTR_LABEL, sizeof(ct_info->label),
 713                     &ct_info->label))
 714                 return -EMSGSIZE;
 715         if (ct_info->helper) {
 716                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
 717                                    ct_info->helper->name))
 718                         return -EMSGSIZE;
 719         }
 720
 721         nla_nest_end(skb, start);
 722
 723         return 0;
 724 }
 725
 726 void ovs_ct_free_action(const struct nlattr *a)
 727 {
 728         struct ovs_conntrack_info *ct_info = nla_data(a);
 729
 730         if (ct_info->helper)
 731                 module_put(ct_info->helper->me);
 732         if (ct_info->ct)
 733                 nf_ct_put(ct_info->ct);
 734 }
 735
 736 void ovs_ct_init(struct net *net)
 737 {
 738         unsigned int n_bits = sizeof(struct ovs_key_ct_label) * BITS_PER_BYTE;
 739         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 740
 741         if (nf_connlabels_get(net, n_bits)) {
 742                 ovs_net->xt_label = false;
 743                 OVS_NLERR(true, "Failed to set connlabel length");
 744         } else {
 745                 ovs_net->xt_label = true;
 746         }
 747 }
 748
 749 void ovs_ct_exit(struct net *net)
 750 {
 751         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 752
 753         if (ovs_net->xt_label)
 754                 nf_connlabels_put(net);
 755 }