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                 ct_state |= OVS_CS_F_REPLY_DIR;
  79                 break;
  80         default:
  81                 break;
  82         }
  83
  84         switch (ctinfo) {
  85         case IP_CT_ESTABLISHED:
  86         case IP_CT_ESTABLISHED_REPLY:
  87                 ct_state |= OVS_CS_F_ESTABLISHED;
  88                 break;
  89         case IP_CT_RELATED:
  90         case IP_CT_RELATED_REPLY:
  91                 ct_state |= OVS_CS_F_RELATED;
  92                 break;
  93         case IP_CT_NEW:
  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                               const struct ovs_conntrack_info *info,
 145                               struct sw_flow_key *key, bool post_ct)
 146 {
 147         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 148         enum ip_conntrack_info ctinfo;
 149         struct nf_conn *ct;
 150         u8 state = 0;
 151
 152         ct = nf_ct_get(skb, &ctinfo);
 153         if (ct) {
 154                 state = ovs_ct_get_state(ctinfo);
 155                 if (!nf_ct_is_confirmed(ct))
 156                         state |= OVS_CS_F_NEW;
 157                 if (ct->master)
 158                         state |= OVS_CS_F_RELATED;
 159                 zone = nf_ct_zone(ct);
 160         } else if (post_ct) {
 161                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 162                 if (info)
 163                         zone = &info->zone;
 164         }
 165         __ovs_ct_update_key(key, state, zone, ct);
 166 }
 167
 168 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 169 {
 170         ovs_ct_update_key(skb, NULL, key, false);
 171 }
 172
 173 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 174 {
 175         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 176                 return -EMSGSIZE;
 177
 178         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 179             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 180                 return -EMSGSIZE;
 181
 182         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 183             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 184                 return -EMSGSIZE;
 185
 186         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 187             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
 188                     &key->ct.labels))
 189                 return -EMSGSIZE;
 190
 191         return 0;
 192 }
 193
 194 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 195                            u32 ct_mark, u32 mask)
 196 {
 197 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 198         enum ip_conntrack_info ctinfo;
 199         struct nf_conn *ct;
 200         u32 new_mark;
 201
 202
 203         /* The connection could be invalid, in which case set_mark is no-op. */
 204         ct = nf_ct_get(skb, &ctinfo);
 205         if (!ct)
 206                 return 0;
 207
 208         new_mark = ct_mark | (ct->mark & ~(mask));
 209         if (ct->mark != new_mark) {
 210                 ct->mark = new_mark;
 211                 nf_conntrack_event_cache(IPCT_MARK, ct);
 212                 key->ct.mark = new_mark;
 213         }
 214
 215         return 0;
 216 #else
 217         return -ENOTSUPP;
 218 #endif
 219 }
 220
 221 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
 222                              const struct ovs_key_ct_labels *labels,
 223                              const struct ovs_key_ct_labels *mask)
 224 {
 225         enum ip_conntrack_info ctinfo;
 226         struct nf_conn_labels *cl;
 227         struct nf_conn *ct;
 228         int err;
 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 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 300  * value if 'skb' is freed.
 301  */
 302 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 303                             u16 zone, struct sk_buff *skb)
 304 {
 305         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 306         int err;
 307
 308         if (key->eth.type == htons(ETH_P_IP)) {
 309                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 310
 311                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 312                 err = ip_defrag(net, skb, user);
 313                 if (err)
 314                         return err;
 315
 316                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 317 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 318         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 319                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 320
 321                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 322                 err = nf_ct_frag6_gather(net, skb, user);
 323                 if (err)
 324                         return err;
 325
 326                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
 327                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 328 #endif
 329         } else {
 330                 kfree_skb(skb);
 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, net, &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, 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         ovs_ct_update_key(skb, info, key, true);
 410
 411         return 0;
 412 }
 413
 414 /* Lookup connection and read fields into key. */
 415 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 416                          const struct ovs_conntrack_info *info,
 417                          struct sk_buff *skb)
 418 {
 419         struct nf_conntrack_expect *exp;
 420
 421         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 422         if (exp) {
 423                 u8 state;
 424
 425                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 426                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 427         } else {
 428                 int err;
 429
 430                 err = __ovs_ct_lookup(net, key, info, skb);
 431                 if (err)
 432                         return err;
 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         return 0;
 462 }
 463
 464 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
 465 {
 466         size_t i;
 467
 468         for (i = 0; i < sizeof(*labels); i++)
 469                 if (labels->ct_labels[i])
 470                         return true;
 471
 472         return false;
 473 }
 474
 475 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 476  * value if 'skb' is freed.
 477  */
 478 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 479                    struct sw_flow_key *key,
 480                    const struct ovs_conntrack_info *info)
 481 {
 482         int nh_ofs;
 483         int err;
 484
 485         /* The conntrack module expects to be working at L3. */
 486         nh_ofs = skb_network_offset(skb);
 487         skb_pull(skb, nh_ofs);
 488
 489         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 490                 err = handle_fragments(net, key, info->zone.id, skb);
 491                 if (err)
 492                         return err;
 493         }
 494
 495         if (info->commit)
 496                 err = ovs_ct_commit(net, key, info, skb);
 497         else
 498                 err = ovs_ct_lookup(net, key, info, skb);
 499         if (err)
 500                 goto err;
 501
 502         if (info->mark.mask) {
 503                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 504                                       info->mark.mask);
 505                 if (err)
 506                         goto err;
 507         }
 508         if (labels_nonzero(&info->labels.mask))
 509                 err = ovs_ct_set_labels(skb, key, &info->labels.value,
 510                                         &info->labels.mask);
 511 err:
 512         skb_push(skb, nh_ofs);
 513         if (err)
 514                 kfree_skb(skb);
 515         return err;
 516 }
 517
 518 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 519                              const struct sw_flow_key *key, bool log)
 520 {
 521         struct nf_conntrack_helper *helper;
 522         struct nf_conn_help *help;
 523
 524         helper = nf_conntrack_helper_try_module_get(name, info->family,
 525                                                     key->ip.proto);
 526         if (!helper) {
 527                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 528                 return -EINVAL;
 529         }
 530
 531         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 532         if (!help) {
 533                 module_put(helper->me);
 534                 return -ENOMEM;
 535         }
 536
 537         rcu_assign_pointer(help->helper, helper);
 538         info->helper = helper;
 539         return 0;
 540 }
 541
 542 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
 543         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
 544         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
 545                                     .maxlen = sizeof(u16) },
 546         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
 547                                     .maxlen = sizeof(struct md_mark) },
 548         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
 549                                     .maxlen = sizeof(struct md_labels) },
 550         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
 551                                     .maxlen = NF_CT_HELPER_NAME_LEN }
 552 };
 553
 554 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
 555                     const char **helper, bool log)
 556 {
 557         struct nlattr *a;
 558         int rem;
 559
 560         nla_for_each_nested(a, attr, rem) {
 561                 int type = nla_type(a);
 562                 int maxlen = ovs_ct_attr_lens[type].maxlen;
 563                 int minlen = ovs_ct_attr_lens[type].minlen;
 564
 565                 if (type > OVS_CT_ATTR_MAX) {
 566                         OVS_NLERR(log,
 567                                   "Unknown conntrack attr (type=%d, max=%d)",
 568                                   type, OVS_CT_ATTR_MAX);
 569                         return -EINVAL;
 570                 }
 571                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
 572                         OVS_NLERR(log,
 573                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
 574                                   type, nla_len(a), maxlen);
 575                         return -EINVAL;
 576                 }
 577
 578                 switch (type) {
 579                 case OVS_CT_ATTR_COMMIT:
 580                         info->commit = true;
 581                         break;
 582 #ifdef CONFIG_NF_CONNTRACK_ZONES
 583                 case OVS_CT_ATTR_ZONE:
 584                         info->zone.id = nla_get_u16(a);
 585                         break;
 586 #endif
 587 #ifdef CONFIG_NF_CONNTRACK_MARK
 588                 case OVS_CT_ATTR_MARK: {
 589                         struct md_mark *mark = nla_data(a);
 590
 591                         if (!mark->mask) {
 592                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
 593                                 return -EINVAL;
 594                         }
 595                         info->mark = *mark;
 596                         break;
 597                 }
 598 #endif
 599 #ifdef CONFIG_NF_CONNTRACK_LABELS
 600                 case OVS_CT_ATTR_LABELS: {
 601                         struct md_labels *labels = nla_data(a);
 602
 603                         if (!labels_nonzero(&labels->mask)) {
 604                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
 605                                 return -EINVAL;
 606                         }
 607                         info->labels = *labels;
 608                         break;
 609                 }
 610 #endif
 611                 case OVS_CT_ATTR_HELPER:
 612                         *helper = nla_data(a);
 613                         if (!memchr(*helper, '\0', nla_len(a))) {
 614                                 OVS_NLERR(log, "Invalid conntrack helper");
 615                                 return -EINVAL;
 616                         }
 617                         break;
 618                 default:
 619                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
 620                                   type);
 621                         return -EINVAL;
 622                 }
 623         }
 624
 625         if (rem > 0) {
 626                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
 627                 return -EINVAL;
 628         }
 629
 630         return 0;
 631 }
 632
 633 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
 634 {
 635         if (attr == OVS_KEY_ATTR_CT_STATE)
 636                 return true;
 637         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 638             attr == OVS_KEY_ATTR_CT_ZONE)
 639                 return true;
 640         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 641             attr == OVS_KEY_ATTR_CT_MARK)
 642                 return true;
 643         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 644             attr == OVS_KEY_ATTR_CT_LABELS) {
 645                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 646
 647                 return ovs_net->xt_label;
 648         }
 649
 650         return false;
 651 }
 652
 653 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
 654                        const struct sw_flow_key *key,
 655                        struct sw_flow_actions **sfa,  bool log)
 656 {
 657         struct ovs_conntrack_info ct_info;
 658         const char *helper = NULL;
 659         u16 family;
 660         int err;
 661
 662         family = key_to_nfproto(key);
 663         if (family == NFPROTO_UNSPEC) {
 664                 OVS_NLERR(log, "ct family unspecified");
 665                 return -EINVAL;
 666         }
 667
 668         memset(&ct_info, 0, sizeof(ct_info));
 669         ct_info.family = family;
 670
 671         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
 672                         NF_CT_DEFAULT_ZONE_DIR, 0);
 673
 674         err = parse_ct(attr, &ct_info, &helper, log);
 675         if (err)
 676                 return err;
 677
 678         /* Set up template for tracking connections in specific zones. */
 679         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
 680         if (!ct_info.ct) {
 681                 OVS_NLERR(log, "Failed to allocate conntrack template");
 682                 return -ENOMEM;
 683         }
 684
 685         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
 686         nf_conntrack_get(&ct_info.ct->ct_general);
 687
 688         if (helper) {
 689                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
 690                 if (err)
 691                         goto err_free_ct;
 692         }
 693
 694         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
 695                                  sizeof(ct_info), log);
 696         if (err)
 697                 goto err_free_ct;
 698
 699         return 0;
 700 err_free_ct:
 701         __ovs_ct_free_action(&ct_info);
 702         return err;
 703 }
 704
 705 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
 706                           struct sk_buff *skb)
 707 {
 708         struct nlattr *start;
 709
 710         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
 711         if (!start)
 712                 return -EMSGSIZE;
 713
 714         if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
 715                 return -EMSGSIZE;
 716         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 717             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
 718                 return -EMSGSIZE;
 719         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
 720             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
 721                     &ct_info->mark))
 722                 return -EMSGSIZE;
 723         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 724             labels_nonzero(&ct_info->labels.mask) &&
 725             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
 726                     &ct_info->labels))
 727                 return -EMSGSIZE;
 728         if (ct_info->helper) {
 729                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
 730                                    ct_info->helper->name))
 731                         return -EMSGSIZE;
 732         }
 733
 734         nla_nest_end(skb, start);
 735
 736         return 0;
 737 }
 738
 739 void ovs_ct_free_action(const struct nlattr *a)
 740 {
 741         struct ovs_conntrack_info *ct_info = nla_data(a);
 742
 743         __ovs_ct_free_action(ct_info);
 744 }
 745
 746 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
 747 {
 748         if (ct_info->helper)
 749                 module_put(ct_info->helper->me);
 750         if (ct_info->ct)
 751                 nf_ct_put(ct_info->ct);
 752 }
 753
 754 void ovs_ct_init(struct net *net)
 755 {
 756         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
 757         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 758
 759         if (nf_connlabels_get(net, n_bits)) {
 760                 ovs_net->xt_label = false;
 761                 OVS_NLERR(true, "Failed to set connlabel length");
 762         } else {
 763                 ovs_net->xt_label = true;
 764         }
 765 }
 766
 767 void ovs_ct_exit(struct net *net)
 768 {
 769         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
 770
 771         if (ovs_net->xt_label)
 772                 nf_connlabels_put(net);
 773 }