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 <linux/tcp.h>
  17 #include <linux/udp.h>
  18 #include <linux/sctp.h>
  19 #include <net/ip.h>
  20 #include <net/netfilter/nf_conntrack_core.h>
  21 #include <net/netfilter/nf_conntrack_helper.h>
  22 #include <net/netfilter/nf_conntrack_labels.h>
  23 #include <net/netfilter/nf_conntrack_seqadj.h>
  24 #include <net/netfilter/nf_conntrack_zones.h>
  25 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  26
  27 #ifdef CONFIG_NF_NAT_NEEDED
  28 #include <linux/netfilter/nf_nat.h>
  29 #include <net/netfilter/nf_nat_core.h>
  30 #include <net/netfilter/nf_nat_l3proto.h>
  31 #endif
  32
  33 #include "datapath.h"
  34 #include "conntrack.h"
  35 #include "flow.h"
  36 #include "flow_netlink.h"
  37
  38 struct ovs_ct_len_tbl {
  39         int maxlen;
  40         int minlen;
  41 };
  42
  43 /* Metadata mark for masked write to conntrack mark */
  44 struct md_mark {
  45         u32 value;
  46         u32 mask;
  47 };
  48
  49 /* Metadata label for masked write to conntrack label. */
  50 struct md_labels {
  51         struct ovs_key_ct_labels value;
  52         struct ovs_key_ct_labels mask;
  53 };
  54
  55 enum ovs_ct_nat {
  56         OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
  57         OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
  58         OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
  59 };
  60
  61 /* Conntrack action context for execution. */
  62 struct ovs_conntrack_info {
  63         struct nf_conntrack_helper *helper;
  64         struct nf_conntrack_zone zone;
  65         struct nf_conn *ct;
  66         u8 commit : 1;
  67         u8 nat : 3;                 /* enum ovs_ct_nat */
  68         u16 family;
  69         struct md_mark mark;
  70         struct md_labels labels;
  71 #ifdef CONFIG_NF_NAT_NEEDED
  72         struct nf_nat_range range;  /* Only present for SRC NAT and DST NAT. */
  73 #endif
  74 };
  75
  76 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
  77
  78 static u16 key_to_nfproto(const struct sw_flow_key *key)
  79 {
  80         switch (ntohs(key->eth.type)) {
  81         case ETH_P_IP:
  82                 return NFPROTO_IPV4;
  83         case ETH_P_IPV6:
  84                 return NFPROTO_IPV6;
  85         default:
  86                 return NFPROTO_UNSPEC;
  87         }
  88 }
  89
  90 /* Map SKB connection state into the values used by flow definition. */
  91 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
  92 {
  93         u8 ct_state = OVS_CS_F_TRACKED;
  94
  95         switch (ctinfo) {
  96         case IP_CT_ESTABLISHED_REPLY:
  97         case IP_CT_RELATED_REPLY:
  98                 ct_state |= OVS_CS_F_REPLY_DIR;
  99                 break;
 100         default:
 101                 break;
 102         }
 103
 104         switch (ctinfo) {
 105         case IP_CT_ESTABLISHED:
 106         case IP_CT_ESTABLISHED_REPLY:
 107                 ct_state |= OVS_CS_F_ESTABLISHED;
 108                 break;
 109         case IP_CT_RELATED:
 110         case IP_CT_RELATED_REPLY:
 111                 ct_state |= OVS_CS_F_RELATED;
 112                 break;
 113         case IP_CT_NEW:
 114                 ct_state |= OVS_CS_F_NEW;
 115                 break;
 116         default:
 117                 break;
 118         }
 119
 120         return ct_state;
 121 }
 122
 123 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
 124 {
 125 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 126         return ct ? ct->mark : 0;
 127 #else
 128         return 0;
 129 #endif
 130 }
 131
 132 static void ovs_ct_get_labels(const struct nf_conn *ct,
 133                               struct ovs_key_ct_labels *labels)
 134 {
 135         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
 136
 137         if (cl) {
 138                 size_t len = cl->words * sizeof(long);
 139
 140                 if (len > OVS_CT_LABELS_LEN)
 141                         len = OVS_CT_LABELS_LEN;
 142                 else if (len < OVS_CT_LABELS_LEN)
 143                         memset(labels, 0, OVS_CT_LABELS_LEN);
 144                 memcpy(labels, cl->bits, len);
 145         } else {
 146                 memset(labels, 0, OVS_CT_LABELS_LEN);
 147         }
 148 }
 149
 150 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
 151                                 const struct nf_conntrack_zone *zone,
 152                                 const struct nf_conn *ct)
 153 {
 154         key->ct.state = state;
 155         key->ct.zone = zone->id;
 156         key->ct.mark = ovs_ct_get_mark(ct);
 157         ovs_ct_get_labels(ct, &key->ct.labels);
 158 }
 159
 160 /* Update 'key' based on skb->nfct.  If 'post_ct' is true, then OVS has
 161  * previously sent the packet to conntrack via the ct action.  If
 162  * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
 163  * initialized from the connection status.
 164  */
 165 static void ovs_ct_update_key(const struct sk_buff *skb,
 166                               const struct ovs_conntrack_info *info,
 167                               struct sw_flow_key *key, bool post_ct,
 168                               bool keep_nat_flags)
 169 {
 170         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 171         enum ip_conntrack_info ctinfo;
 172         struct nf_conn *ct;
 173         u8 state = 0;
 174
 175         ct = nf_ct_get(skb, &ctinfo);
 176         if (ct) {
 177                 state = ovs_ct_get_state(ctinfo);
 178                 /* All unconfirmed entries are NEW connections. */
 179                 if (!nf_ct_is_confirmed(ct))
 180                         state |= OVS_CS_F_NEW;
 181                 /* OVS persists the related flag for the duration of the
 182                  * connection.
 183                  */
 184                 if (ct->master)
 185                         state |= OVS_CS_F_RELATED;
 186                 if (keep_nat_flags) {
 187                         state |= key->ct.state & OVS_CS_F_NAT_MASK;
 188                 } else {
 189                         if (ct->status & IPS_SRC_NAT)
 190                                 state |= OVS_CS_F_SRC_NAT;
 191                         if (ct->status & IPS_DST_NAT)
 192                                 state |= OVS_CS_F_DST_NAT;
 193                 }
 194                 zone = nf_ct_zone(ct);
 195         } else if (post_ct) {
 196                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 197                 if (info)
 198                         zone = &info->zone;
 199         }
 200         __ovs_ct_update_key(key, state, zone, ct);
 201 }
 202
 203 /* This is called to initialize CT key fields possibly coming in from the local
 204  * stack.
 205  */
 206 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 207 {
 208         ovs_ct_update_key(skb, NULL, key, false, false);
 209 }
 210
 211 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 212 {
 213         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 214                 return -EMSGSIZE;
 215
 216         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 217             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 218                 return -EMSGSIZE;
 219
 220         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 221             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 222                 return -EMSGSIZE;
 223
 224         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 225             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
 226                     &key->ct.labels))
 227                 return -EMSGSIZE;
 228
 229         return 0;
 230 }
 231
 232 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 233                            u32 ct_mark, u32 mask)
 234 {
 235 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 236         enum ip_conntrack_info ctinfo;
 237         struct nf_conn *ct;
 238         u32 new_mark;
 239
 240         /* The connection could be invalid, in which case set_mark is no-op. */
 241         ct = nf_ct_get(skb, &ctinfo);
 242         if (!ct)
 243                 return 0;
 244
 245         new_mark = ct_mark | (ct->mark & ~(mask));
 246         if (ct->mark != new_mark) {
 247                 ct->mark = new_mark;
 248                 nf_conntrack_event_cache(IPCT_MARK, ct);
 249                 key->ct.mark = new_mark;
 250         }
 251
 252         return 0;
 253 #else
 254         return -ENOTSUPP;
 255 #endif
 256 }
 257
 258 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
 259                              const struct ovs_key_ct_labels *labels,
 260                              const struct ovs_key_ct_labels *mask)
 261 {
 262         enum ip_conntrack_info ctinfo;
 263         struct nf_conn_labels *cl;
 264         struct nf_conn *ct;
 265         int err;
 266
 267         /* The connection could be invalid, in which case set_label is no-op.*/
 268         ct = nf_ct_get(skb, &ctinfo);
 269         if (!ct)
 270                 return 0;
 271
 272         cl = nf_ct_labels_find(ct);
 273         if (!cl) {
 274                 nf_ct_labels_ext_add(ct);
 275                 cl = nf_ct_labels_find(ct);
 276         }
 277         if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
 278                 return -ENOSPC;
 279
 280         err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
 281                                     OVS_CT_LABELS_LEN / sizeof(u32));
 282         if (err)
 283                 return err;
 284
 285         ovs_ct_get_labels(ct, &key->ct.labels);
 286         return 0;
 287 }
 288
 289 /* 'skb' should already be pulled to nh_ofs. */
 290 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 291 {
 292         const struct nf_conntrack_helper *helper;
 293         const struct nf_conn_help *help;
 294         enum ip_conntrack_info ctinfo;
 295         unsigned int protoff;
 296         struct nf_conn *ct;
 297         int err;
 298
 299         ct = nf_ct_get(skb, &ctinfo);
 300         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 301                 return NF_ACCEPT;
 302
 303         help = nfct_help(ct);
 304         if (!help)
 305                 return NF_ACCEPT;
 306
 307         helper = rcu_dereference(help->helper);
 308         if (!helper)
 309                 return NF_ACCEPT;
 310
 311         switch (proto) {
 312         case NFPROTO_IPV4:
 313                 protoff = ip_hdrlen(skb);
 314                 break;
 315         case NFPROTO_IPV6: {
 316                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 317                 __be16 frag_off;
 318                 int ofs;
 319
 320                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 321                                        &frag_off);
 322                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 323                         pr_debug("proto header not found\n");
 324                         return NF_ACCEPT;
 325                 }
 326                 protoff = ofs;
 327                 break;
 328         }
 329         default:
 330                 WARN_ONCE(1, "helper invoked on non-IP family!");
 331                 return NF_DROP;
 332         }
 333
 334         err = helper->help(skb, protoff, ct, ctinfo);
 335         if (err != NF_ACCEPT)
 336                 return err;
 337
 338         /* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
 339          * FTP with NAT) adusting the TCP payload size when mangling IP
 340          * addresses and/or port numbers in the text-based control connection.
 341          */
 342         if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
 343             !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
 344                 return NF_DROP;
 345         return NF_ACCEPT;
 346 }
 347
 348 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 349  * value if 'skb' is freed.
 350  */
 351 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 352                             u16 zone, struct sk_buff *skb)
 353 {
 354         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 355         int err;
 356
 357         if (key->eth.type == htons(ETH_P_IP)) {
 358                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 359
 360                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 361                 err = ip_defrag(net, skb, user);
 362                 if (err)
 363                         return err;
 364
 365                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 366 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 367         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 368                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 369
 370                 skb_orphan(skb);
 371                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 372                 err = nf_ct_frag6_gather(net, skb, user);
 373                 if (err)
 374                         return err;
 375
 376                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
 377                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 378 #endif
 379         } else {
 380                 kfree_skb(skb);
 381                 return -EPFNOSUPPORT;
 382         }
 383
 384         key->ip.frag = OVS_FRAG_TYPE_NONE;
 385         skb_clear_hash(skb);
 386         skb->ignore_df = 1;
 387         *OVS_CB(skb) = ovs_cb;
 388
 389         return 0;
 390 }
 391
 392 static struct nf_conntrack_expect *
 393 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 394                    u16 proto, const struct sk_buff *skb)
 395 {
 396         struct nf_conntrack_tuple tuple;
 397
 398         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
 399                 return NULL;
 400         return __nf_ct_expect_find(net, zone, &tuple);
 401 }
 402
 403 /* This replicates logic from nf_conntrack_core.c that is not exported. */
 404 static enum ip_conntrack_info
 405 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
 406 {
 407         const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 408
 409         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
 410                 return IP_CT_ESTABLISHED_REPLY;
 411         /* Once we've had two way comms, always ESTABLISHED. */
 412         if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 413                 return IP_CT_ESTABLISHED;
 414         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
 415                 return IP_CT_RELATED;
 416         return IP_CT_NEW;
 417 }
 418
 419 /* Find an existing connection which this packet belongs to without
 420  * re-attributing statistics or modifying the connection state.  This allows an
 421  * skb->nfct lost due to an upcall to be recovered during actions execution.
 422  *
 423  * Must be called with rcu_read_lock.
 424  *
 425  * On success, populates skb->nfct and skb->nfctinfo, and returns the
 426  * connection.  Returns NULL if there is no existing entry.
 427  */
 428 static struct nf_conn *
 429 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
 430                      u8 l3num, struct sk_buff *skb)
 431 {
 432         struct nf_conntrack_l3proto *l3proto;
 433         struct nf_conntrack_l4proto *l4proto;
 434         struct nf_conntrack_tuple tuple;
 435         struct nf_conntrack_tuple_hash *h;
 436         enum ip_conntrack_info ctinfo;
 437         struct nf_conn *ct;
 438         unsigned int dataoff;
 439         u8 protonum;
 440
 441         l3proto = __nf_ct_l3proto_find(l3num);
 442         if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff,
 443                                  &protonum) <= 0) {
 444                 pr_debug("ovs_ct_find_existing: Can't get protonum\n");
 445                 return NULL;
 446         }
 447         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 448         if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
 449                              protonum, net, &tuple, l3proto, l4proto)) {
 450                 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
 451                 return NULL;
 452         }
 453
 454         /* look for tuple match */
 455         h = nf_conntrack_find_get(net, zone, &tuple);
 456         if (!h)
 457                 return NULL;   /* Not found. */
 458
 459         ct = nf_ct_tuplehash_to_ctrack(h);
 460
 461         ctinfo = ovs_ct_get_info(h);
 462         if (ctinfo == IP_CT_NEW) {
 463                 /* This should not happen. */
 464                 WARN_ONCE(1, "ovs_ct_find_existing: new packet for %p\n", ct);
 465         }
 466         skb->nfct = &ct->ct_general;
 467         skb->nfctinfo = ctinfo;
 468         return ct;
 469 }
 470
 471 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
 472 static bool skb_nfct_cached(struct net *net,
 473                             const struct sw_flow_key *key,
 474                             const struct ovs_conntrack_info *info,
 475                             struct sk_buff *skb)
 476 {
 477         enum ip_conntrack_info ctinfo;
 478         struct nf_conn *ct;
 479
 480         ct = nf_ct_get(skb, &ctinfo);
 481         /* If no ct, check if we have evidence that an existing conntrack entry
 482          * might be found for this skb.  This happens when we lose a skb->nfct
 483          * due to an upcall.  If the connection was not confirmed, it is not
 484          * cached and needs to be run through conntrack again.
 485          */
 486         if (!ct && key->ct.state & OVS_CS_F_TRACKED &&
 487             !(key->ct.state & OVS_CS_F_INVALID) &&
 488             key->ct.zone == info->zone.id)
 489                 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb);
 490         if (!ct)
 491                 return false;
 492         if (!net_eq(net, read_pnet(&ct->ct_net)))
 493                 return false;
 494         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 495                 return false;
 496         if (info->helper) {
 497                 struct nf_conn_help *help;
 498
 499                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 500                 if (help && rcu_access_pointer(help->helper) != info->helper)
 501                         return false;
 502         }
 503
 504         return true;
 505 }
 506
 507 #ifdef CONFIG_NF_NAT_NEEDED
 508 /* Modelled after nf_nat_ipv[46]_fn().
 509  * range is only used for new, uninitialized NAT state.
 510  * Returns either NF_ACCEPT or NF_DROP.
 511  */
 512 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 513                               enum ip_conntrack_info ctinfo,
 514                               const struct nf_nat_range *range,
 515                               enum nf_nat_manip_type maniptype)
 516 {
 517         int hooknum, nh_off, err = NF_ACCEPT;
 518
 519         nh_off = skb_network_offset(skb);
 520         skb_pull(skb, nh_off);
 521
 522         /* See HOOK2MANIP(). */
 523         if (maniptype == NF_NAT_MANIP_SRC)
 524                 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
 525         else
 526                 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
 527
 528         switch (ctinfo) {
 529         case IP_CT_RELATED:
 530         case IP_CT_RELATED_REPLY:
 531                 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
 532                     skb->protocol == htons(ETH_P_IP) &&
 533                     ip_hdr(skb)->protocol == IPPROTO_ICMP) {
 534                         if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
 535                                                            hooknum))
 536                                 err = NF_DROP;
 537                         goto push;
 538                 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
 539                            skb->protocol == htons(ETH_P_IPV6)) {
 540                         __be16 frag_off;
 541                         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 542                         int hdrlen = ipv6_skip_exthdr(skb,
 543                                                       sizeof(struct ipv6hdr),
 544                                                       &nexthdr, &frag_off);
 545
 546                         if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
 547                                 if (!nf_nat_icmpv6_reply_translation(skb, ct,
 548                                                                      ctinfo,
 549                                                                      hooknum,
 550                                                                      hdrlen))
 551                                         err = NF_DROP;
 552                                 goto push;
 553                         }
 554                 }
 555                 /* Non-ICMP, fall thru to initialize if needed. */
 556         case IP_CT_NEW:
 557                 /* Seen it before?  This can happen for loopback, retrans,
 558                  * or local packets.
 559                  */
 560                 if (!nf_nat_initialized(ct, maniptype)) {
 561                         /* Initialize according to the NAT action. */
 562                         err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
 563                                 /* Action is set up to establish a new
 564                                  * mapping.
 565                                  */
 566                                 ? nf_nat_setup_info(ct, range, maniptype)
 567                                 : nf_nat_alloc_null_binding(ct, hooknum);
 568                         if (err != NF_ACCEPT)
 569                                 goto push;
 570                 }
 571                 break;
 572
 573         case IP_CT_ESTABLISHED:
 574         case IP_CT_ESTABLISHED_REPLY:
 575                 break;
 576
 577         default:
 578                 err = NF_DROP;
 579                 goto push;
 580         }
 581
 582         err = nf_nat_packet(ct, ctinfo, hooknum, skb);
 583 push:
 584         skb_push(skb, nh_off);
 585
 586         return err;
 587 }
 588
 589 static void ovs_nat_update_key(struct sw_flow_key *key,
 590                                const struct sk_buff *skb,
 591                                enum nf_nat_manip_type maniptype)
 592 {
 593         if (maniptype == NF_NAT_MANIP_SRC) {
 594                 __be16 src;
 595
 596                 key->ct.state |= OVS_CS_F_SRC_NAT;
 597                 if (key->eth.type == htons(ETH_P_IP))
 598                         key->ipv4.addr.src = ip_hdr(skb)->saddr;
 599                 else if (key->eth.type == htons(ETH_P_IPV6))
 600                         memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
 601                                sizeof(key->ipv6.addr.src));
 602                 else
 603                         return;
 604
 605                 if (key->ip.proto == IPPROTO_UDP)
 606                         src = udp_hdr(skb)->source;
 607                 else if (key->ip.proto == IPPROTO_TCP)
 608                         src = tcp_hdr(skb)->source;
 609                 else if (key->ip.proto == IPPROTO_SCTP)
 610                         src = sctp_hdr(skb)->source;
 611                 else
 612                         return;
 613
 614                 key->tp.src = src;
 615         } else {
 616                 __be16 dst;
 617
 618                 key->ct.state |= OVS_CS_F_DST_NAT;
 619                 if (key->eth.type == htons(ETH_P_IP))
 620                         key->ipv4.addr.dst = ip_hdr(skb)->daddr;
 621                 else if (key->eth.type == htons(ETH_P_IPV6))
 622                         memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
 623                                sizeof(key->ipv6.addr.dst));
 624                 else
 625                         return;
 626
 627                 if (key->ip.proto == IPPROTO_UDP)
 628                         dst = udp_hdr(skb)->dest;
 629                 else if (key->ip.proto == IPPROTO_TCP)
 630                         dst = tcp_hdr(skb)->dest;
 631                 else if (key->ip.proto == IPPROTO_SCTP)
 632                         dst = sctp_hdr(skb)->dest;
 633                 else
 634                         return;
 635
 636                 key->tp.dst = dst;
 637         }
 638 }
 639
 640 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
 641 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 642                       const struct ovs_conntrack_info *info,
 643                       struct sk_buff *skb, struct nf_conn *ct,
 644                       enum ip_conntrack_info ctinfo)
 645 {
 646         enum nf_nat_manip_type maniptype;
 647         int err;
 648
 649         if (nf_ct_is_untracked(ct)) {
 650                 /* A NAT action may only be performed on tracked packets. */
 651                 return NF_ACCEPT;
 652         }
 653
 654         /* Add NAT extension if not confirmed yet. */
 655         if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
 656                 return NF_ACCEPT;   /* Can't NAT. */
 657
 658         /* Determine NAT type.
 659          * Check if the NAT type can be deduced from the tracked connection.
 660          * Make sure new expected connections (IP_CT_RELATED) are NATted only
 661          * when committing.
 662          */
 663         if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
 664             ct->status & IPS_NAT_MASK &&
 665             (ctinfo != IP_CT_RELATED || info->commit)) {
 666                 /* NAT an established or related connection like before. */
 667                 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
 668                         /* This is the REPLY direction for a connection
 669                          * for which NAT was applied in the forward
 670                          * direction.  Do the reverse NAT.
 671                          */
 672                         maniptype = ct->status & IPS_SRC_NAT
 673                                 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
 674                 else
 675                         maniptype = ct->status & IPS_SRC_NAT
 676                                 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
 677         } else if (info->nat & OVS_CT_SRC_NAT) {
 678                 maniptype = NF_NAT_MANIP_SRC;
 679         } else if (info->nat & OVS_CT_DST_NAT) {
 680                 maniptype = NF_NAT_MANIP_DST;
 681         } else {
 682                 return NF_ACCEPT; /* Connection is not NATed. */
 683         }
 684         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
 685
 686         /* Mark NAT done if successful and update the flow key. */
 687         if (err == NF_ACCEPT)
 688                 ovs_nat_update_key(key, skb, maniptype);
 689
 690         return err;
 691 }
 692 #else /* !CONFIG_NF_NAT_NEEDED */
 693 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 694                       const struct ovs_conntrack_info *info,
 695                       struct sk_buff *skb, struct nf_conn *ct,
 696                       enum ip_conntrack_info ctinfo)
 697 {
 698         return NF_ACCEPT;
 699 }
 700 #endif
 701
 702 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
 703  * not done already.  Update key with new CT state after passing the packet
 704  * through conntrack.
 705  * Note that if the packet is deemed invalid by conntrack, skb->nfct will be
 706  * set to NULL and 0 will be returned.
 707  */
 708 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 709                            const struct ovs_conntrack_info *info,
 710                            struct sk_buff *skb)
 711 {
 712         /* If we are recirculating packets to match on conntrack fields and
 713          * committing with a separate conntrack action,  then we don't need to
 714          * actually run the packet through conntrack twice unless it's for a
 715          * different zone.
 716          */
 717         bool cached = skb_nfct_cached(net, key, info, skb);
 718         enum ip_conntrack_info ctinfo;
 719         struct nf_conn *ct;
 720
 721         if (!cached) {
 722                 struct nf_conn *tmpl = info->ct;
 723                 int err;
 724
 725                 /* Associate skb with specified zone. */
 726                 if (tmpl) {
 727                         if (skb->nfct)
 728                                 nf_conntrack_put(skb->nfct);
 729                         nf_conntrack_get(&tmpl->ct_general);
 730                         skb->nfct = &tmpl->ct_general;
 731                         skb->nfctinfo = IP_CT_NEW;
 732                 }
 733
 734                 /* Repeat if requested, see nf_iterate(). */
 735                 do {
 736                         err = nf_conntrack_in(net, info->family,
 737                                               NF_INET_PRE_ROUTING, skb);
 738                 } while (err == NF_REPEAT);
 739
 740                 if (err != NF_ACCEPT)
 741                         return -ENOENT;
 742
 743                 /* Clear CT state NAT flags to mark that we have not yet done
 744                  * NAT after the nf_conntrack_in() call.  We can actually clear
 745                  * the whole state, as it will be re-initialized below.
 746                  */
 747                 key->ct.state = 0;
 748
 749                 /* Update the key, but keep the NAT flags. */
 750                 ovs_ct_update_key(skb, info, key, true, true);
 751         }
 752
 753         ct = nf_ct_get(skb, &ctinfo);
 754         if (ct) {
 755                 /* Packets starting a new connection must be NATted before the
 756                  * helper, so that the helper knows about the NAT.  We enforce
 757                  * this by delaying both NAT and helper calls for unconfirmed
 758                  * connections until the committing CT action.  For later
 759                  * packets NAT and Helper may be called in either order.
 760                  *
 761                  * NAT will be done only if the CT action has NAT, and only
 762                  * once per packet (per zone), as guarded by the NAT bits in
 763                  * the key->ct.state.
 764                  */
 765                 if (info->nat && !(key->ct.state & OVS_CS_F_NAT_MASK) &&
 766                     (nf_ct_is_confirmed(ct) || info->commit) &&
 767                     ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
 768                         return -EINVAL;
 769                 }
 770
 771                 /* Userspace may decide to perform a ct lookup without a helper
 772                  * specified followed by a (recirculate and) commit with one.
 773                  * Therefore, for unconfirmed connections which we will commit,
 774                  * we need to attach the helper here.
 775                  */
 776                 if (!nf_ct_is_confirmed(ct) && info->commit &&
 777                     info->helper && !nfct_help(ct)) {
 778                         int err = __nf_ct_try_assign_helper(ct, info->ct,
 779                                                             GFP_ATOMIC);
 780                         if (err)
 781                                 return err;
 782                 }
 783
 784                 /* Call the helper only if:
 785                  * - nf_conntrack_in() was executed above ("!cached") for a
 786                  *   confirmed connection, or
 787                  * - When committing an unconfirmed connection.
 788                  */
 789                 if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
 790                     ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 791                         return -EINVAL;
 792                 }
 793         }
 794
 795         return 0;
 796 }
 797
 798 /* Lookup connection and read fields into key. */
 799 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 800                          const struct ovs_conntrack_info *info,
 801                          struct sk_buff *skb)
 802 {
 803         struct nf_conntrack_expect *exp;
 804
 805         /* If we pass an expected packet through nf_conntrack_in() the
 806          * expectation is typically removed, but the packet could still be
 807          * lost in upcall processing.  To prevent this from happening we
 808          * perform an explicit expectation lookup.  Expected connections are
 809          * always new, and will be passed through conntrack only when they are
 810          * committed, as it is OK to remove the expectation at that time.
 811          */
 812         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 813         if (exp) {
 814                 u8 state;
 815
 816                 /* NOTE: New connections are NATted and Helped only when
 817                  * committed, so we are not calling into NAT here.
 818                  */
 819                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 820                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 821         } else {
 822                 struct nf_conn *ct;
 823                 int err;
 824
 825                 err = __ovs_ct_lookup(net, key, info, skb);
 826                 if (err)
 827                         return err;
 828
 829                 ct = (struct nf_conn *)skb->nfct;
 830                 if (ct)
 831                         nf_ct_deliver_cached_events(ct);
 832         }
 833
 834         return 0;
 835 }
 836
 837 /* Lookup connection and confirm if unconfirmed. */
 838 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
 839                          const struct ovs_conntrack_info *info,
 840                          struct sk_buff *skb)
 841 {
 842         int err;
 843
 844         err = __ovs_ct_lookup(net, key, info, skb);
 845         if (err)
 846                 return err;
 847         /* This is a no-op if the connection has already been confirmed. */
 848         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
 849                 return -EINVAL;
 850
 851         return 0;
 852 }
 853
 854 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
 855 {
 856         size_t i;
 857
 858         for (i = 0; i < sizeof(*labels); i++)
 859                 if (labels->ct_labels[i])
 860                         return true;
 861
 862         return false;
 863 }
 864
 865 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 866  * value if 'skb' is freed.
 867  */
 868 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 869                    struct sw_flow_key *key,
 870                    const struct ovs_conntrack_info *info)
 871 {
 872         int nh_ofs;
 873         int err;
 874
 875         /* The conntrack module expects to be working at L3. */
 876         nh_ofs = skb_network_offset(skb);
 877         skb_pull(skb, nh_ofs);
 878
 879         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 880                 err = handle_fragments(net, key, info->zone.id, skb);
 881                 if (err)
 882                         return err;
 883         }
 884
 885         if (info->commit)
 886                 err = ovs_ct_commit(net, key, info, skb);
 887         else
 888                 err = ovs_ct_lookup(net, key, info, skb);
 889         if (err)
 890                 goto err;
 891
 892         if (info->mark.mask) {
 893                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 894                                       info->mark.mask);
 895                 if (err)
 896                         goto err;
 897         }
 898         if (labels_nonzero(&info->labels.mask))
 899                 err = ovs_ct_set_labels(skb, key, &info->labels.value,
 900                                         &info->labels.mask);
 901 err:
 902         skb_push(skb, nh_ofs);
 903         if (err)
 904                 kfree_skb(skb);
 905         return err;
 906 }
 907
 908 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 909                              const struct sw_flow_key *key, bool log)
 910 {
 911         struct nf_conntrack_helper *helper;
 912         struct nf_conn_help *help;
 913
 914         helper = nf_conntrack_helper_try_module_get(name, info->family,
 915                                                     key->ip.proto);
 916         if (!helper) {
 917                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 918                 return -EINVAL;
 919         }
 920
 921         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 922         if (!help) {
 923                 module_put(helper->me);
 924                 return -ENOMEM;
 925         }
 926
 927         rcu_assign_pointer(help->helper, helper);
 928         info->helper = helper;
 929         return 0;
 930 }
 931
 932 #ifdef CONFIG_NF_NAT_NEEDED
 933 static int parse_nat(const struct nlattr *attr,
 934                      struct ovs_conntrack_info *info, bool log)
 935 {
 936         struct nlattr *a;
 937         int rem;
 938         bool have_ip_max = false;
 939         bool have_proto_max = false;
 940         bool ip_vers = (info->family == NFPROTO_IPV6);
 941
 942         nla_for_each_nested(a, attr, rem) {
 943                 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
 944                         [OVS_NAT_ATTR_SRC] = {0, 0},
 945                         [OVS_NAT_ATTR_DST] = {0, 0},
 946                         [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
 947                                                  sizeof(struct in6_addr)},
 948                         [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
 949                                                  sizeof(struct in6_addr)},
 950                         [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
 951                         [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
 952                         [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
 953                         [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
 954                         [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
 955                 };
 956                 int type = nla_type(a);
 957
 958                 if (type > OVS_NAT_ATTR_MAX) {
 959                         OVS_NLERR(log,
 960                                   "Unknown NAT attribute (type=%d, max=%d).\n",
 961                                   type, OVS_NAT_ATTR_MAX);
 962                         return -EINVAL;
 963                 }
 964
 965                 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
 966                         OVS_NLERR(log,
 967                                   "NAT attribute type %d has unexpected length (%d != %d).\n",
 968                                   type, nla_len(a),
 969                                   ovs_nat_attr_lens[type][ip_vers]);
 970                         return -EINVAL;
 971                 }
 972
 973                 switch (type) {
 974                 case OVS_NAT_ATTR_SRC:
 975                 case OVS_NAT_ATTR_DST:
 976                         if (info->nat) {
 977                                 OVS_NLERR(log,
 978                                           "Only one type of NAT may be specified.\n"
 979                                           );
 980                                 return -ERANGE;
 981                         }
 982                         info->nat |= OVS_CT_NAT;
 983                         info->nat |= ((type == OVS_NAT_ATTR_SRC)
 984                                         ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
 985                         break;
 986
 987                 case OVS_NAT_ATTR_IP_MIN:
 988                         nla_memcpy(&info->range.min_addr, a,
 989                                    sizeof(info->range.min_addr));
 990                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
 991                         break;
 992
 993                 case OVS_NAT_ATTR_IP_MAX:
 994                         have_ip_max = true;
 995                         nla_memcpy(&info->range.max_addr, a,
 996                                    sizeof(info->range.max_addr));
 997                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
 998                         break;
 999
1000                 case OVS_NAT_ATTR_PROTO_MIN:
1001                         info->range.min_proto.all = htons(nla_get_u16(a));
1002                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1003                         break;
1004
1005                 case OVS_NAT_ATTR_PROTO_MAX:
1006                         have_proto_max = true;
1007                         info->range.max_proto.all = htons(nla_get_u16(a));
1008                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1009                         break;
1010
1011                 case OVS_NAT_ATTR_PERSISTENT:
1012                         info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1013                         break;
1014
1015                 case OVS_NAT_ATTR_PROTO_HASH:
1016                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1017                         break;
1018
1019                 case OVS_NAT_ATTR_PROTO_RANDOM:
1020                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1021                         break;
1022
1023                 default:
1024                         OVS_NLERR(log, "Unknown nat attribute (%d).\n", type);
1025                         return -EINVAL;
1026                 }
1027         }
1028
1029         if (rem > 0) {
1030                 OVS_NLERR(log, "NAT attribute has %d unknown bytes.\n", rem);
1031                 return -EINVAL;
1032         }
1033         if (!info->nat) {
1034                 /* Do not allow flags if no type is given. */
1035                 if (info->range.flags) {
1036                         OVS_NLERR(log,
1037                                   "NAT flags may be given only when NAT range (SRC or DST) is also specified.\n"
1038                                   );
1039                         return -EINVAL;
1040                 }
1041                 info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1042         } else if (!info->commit) {
1043                 OVS_NLERR(log,
1044                           "NAT attributes may be specified only when CT COMMIT flag is also specified.\n"
1045                           );
1046                 return -EINVAL;
1047         }
1048         /* Allow missing IP_MAX. */
1049         if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1050                 memcpy(&info->range.max_addr, &info->range.min_addr,
1051                        sizeof(info->range.max_addr));
1052         }
1053         /* Allow missing PROTO_MAX. */
1054         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1055             !have_proto_max) {
1056                 info->range.max_proto.all = info->range.min_proto.all;
1057         }
1058         return 0;
1059 }
1060 #endif
1061
1062 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1063         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
1064         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
1065                                     .maxlen = sizeof(u16) },
1066         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
1067                                     .maxlen = sizeof(struct md_mark) },
1068         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
1069                                     .maxlen = sizeof(struct md_labels) },
1070         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
1071                                     .maxlen = NF_CT_HELPER_NAME_LEN },
1072 #ifdef CONFIG_NF_NAT_NEEDED
1073         /* NAT length is checked when parsing the nested attributes. */
1074         [OVS_CT_ATTR_NAT]       = { .minlen = 0, .maxlen = INT_MAX },
1075 #endif
1076 };
1077
1078 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1079                     const char **helper, bool log)
1080 {
1081         struct nlattr *a;
1082         int rem;
1083
1084         nla_for_each_nested(a, attr, rem) {
1085                 int type = nla_type(a);
1086                 int maxlen = ovs_ct_attr_lens[type].maxlen;
1087                 int minlen = ovs_ct_attr_lens[type].minlen;
1088
1089                 if (type > OVS_CT_ATTR_MAX) {
1090                         OVS_NLERR(log,
1091                                   "Unknown conntrack attr (type=%d, max=%d)",
1092                                   type, OVS_CT_ATTR_MAX);
1093                         return -EINVAL;
1094                 }
1095                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1096                         OVS_NLERR(log,
1097                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1098                                   type, nla_len(a), maxlen);
1099                         return -EINVAL;
1100                 }
1101
1102                 switch (type) {
1103                 case OVS_CT_ATTR_COMMIT:
1104                         info->commit = true;
1105                         break;
1106 #ifdef CONFIG_NF_CONNTRACK_ZONES
1107                 case OVS_CT_ATTR_ZONE:
1108                         info->zone.id = nla_get_u16(a);
1109                         break;
1110 #endif
1111 #ifdef CONFIG_NF_CONNTRACK_MARK
1112                 case OVS_CT_ATTR_MARK: {
1113                         struct md_mark *mark = nla_data(a);
1114
1115                         if (!mark->mask) {
1116                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
1117                                 return -EINVAL;
1118                         }
1119                         info->mark = *mark;
1120                         break;
1121                 }
1122 #endif
1123 #ifdef CONFIG_NF_CONNTRACK_LABELS
1124                 case OVS_CT_ATTR_LABELS: {
1125                         struct md_labels *labels = nla_data(a);
1126
1127                         if (!labels_nonzero(&labels->mask)) {
1128                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
1129                                 return -EINVAL;
1130                         }
1131                         info->labels = *labels;
1132                         break;
1133                 }
1134 #endif
1135                 case OVS_CT_ATTR_HELPER:
1136                         *helper = nla_data(a);
1137                         if (!memchr(*helper, '\0', nla_len(a))) {
1138                                 OVS_NLERR(log, "Invalid conntrack helper");
1139                                 return -EINVAL;
1140                         }
1141                         break;
1142 #ifdef CONFIG_NF_NAT_NEEDED
1143                 case OVS_CT_ATTR_NAT: {
1144                         int err = parse_nat(a, info, log);
1145
1146                         if (err)
1147                                 return err;
1148                         break;
1149                 }
1150 #endif
1151                 default:
1152                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
1153                                   type);
1154                         return -EINVAL;
1155                 }
1156         }
1157
1158         if (rem > 0) {
1159                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1160                 return -EINVAL;
1161         }
1162
1163         return 0;
1164 }
1165
1166 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1167 {
1168         if (attr == OVS_KEY_ATTR_CT_STATE)
1169                 return true;
1170         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1171             attr == OVS_KEY_ATTR_CT_ZONE)
1172                 return true;
1173         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1174             attr == OVS_KEY_ATTR_CT_MARK)
1175                 return true;
1176         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1177             attr == OVS_KEY_ATTR_CT_LABELS) {
1178                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1179
1180                 return ovs_net->xt_label;
1181         }
1182
1183         return false;
1184 }
1185
1186 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1187                        const struct sw_flow_key *key,
1188                        struct sw_flow_actions **sfa,  bool log)
1189 {
1190         struct ovs_conntrack_info ct_info;
1191         const char *helper = NULL;
1192         u16 family;
1193         int err;
1194
1195         family = key_to_nfproto(key);
1196         if (family == NFPROTO_UNSPEC) {
1197                 OVS_NLERR(log, "ct family unspecified");
1198                 return -EINVAL;
1199         }
1200
1201         memset(&ct_info, 0, sizeof(ct_info));
1202         ct_info.family = family;
1203
1204         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1205                         NF_CT_DEFAULT_ZONE_DIR, 0);
1206
1207         err = parse_ct(attr, &ct_info, &helper, log);
1208         if (err)
1209                 return err;
1210
1211         /* Set up template for tracking connections in specific zones. */
1212         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1213         if (!ct_info.ct) {
1214                 OVS_NLERR(log, "Failed to allocate conntrack template");
1215                 return -ENOMEM;
1216         }
1217
1218         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1219         nf_conntrack_get(&ct_info.ct->ct_general);
1220
1221         if (helper) {
1222                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1223                 if (err)
1224                         goto err_free_ct;
1225         }
1226
1227         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1228                                  sizeof(ct_info), log);
1229         if (err)
1230                 goto err_free_ct;
1231
1232         return 0;
1233 err_free_ct:
1234         __ovs_ct_free_action(&ct_info);
1235         return err;
1236 }
1237
1238 #ifdef CONFIG_NF_NAT_NEEDED
1239 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1240                                struct sk_buff *skb)
1241 {
1242         struct nlattr *start;
1243
1244         start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1245         if (!start)
1246                 return false;
1247
1248         if (info->nat & OVS_CT_SRC_NAT) {
1249                 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1250                         return false;
1251         } else if (info->nat & OVS_CT_DST_NAT) {
1252                 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1253                         return false;
1254         } else {
1255                 goto out;
1256         }
1257
1258         if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1259                 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
1260                     info->family == NFPROTO_IPV4) {
1261                         if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1262                                             info->range.min_addr.ip) ||
1263                             (info->range.max_addr.ip
1264                              != info->range.min_addr.ip &&
1265                              (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1266                                               info->range.max_addr.ip))))
1267                                 return false;
1268                 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
1269                            info->family == NFPROTO_IPV6) {
1270                         if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1271                                              &info->range.min_addr.in6) ||
1272                             (memcmp(&info->range.max_addr.in6,
1273                                     &info->range.min_addr.in6,
1274                                     sizeof(info->range.max_addr.in6)) &&
1275                              (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1276                                                &info->range.max_addr.in6))))
1277                                 return false;
1278                 } else {
1279                         return false;
1280                 }
1281         }
1282         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1283             (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1284                          ntohs(info->range.min_proto.all)) ||
1285              (info->range.max_proto.all != info->range.min_proto.all &&
1286               nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1287                           ntohs(info->range.max_proto.all)))))
1288                 return false;
1289
1290         if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1291             nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1292                 return false;
1293         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1294             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1295                 return false;
1296         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1297             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1298                 return false;
1299 out:
1300         nla_nest_end(skb, start);
1301
1302         return true;
1303 }
1304 #endif
1305
1306 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1307                           struct sk_buff *skb)
1308 {
1309         struct nlattr *start;
1310
1311         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1312         if (!start)
1313                 return -EMSGSIZE;
1314
1315         if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
1316                 return -EMSGSIZE;
1317         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1318             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1319                 return -EMSGSIZE;
1320         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1321             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1322                     &ct_info->mark))
1323                 return -EMSGSIZE;
1324         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1325             labels_nonzero(&ct_info->labels.mask) &&
1326             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1327                     &ct_info->labels))
1328                 return -EMSGSIZE;
1329         if (ct_info->helper) {
1330                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1331                                    ct_info->helper->name))
1332                         return -EMSGSIZE;
1333         }
1334 #ifdef CONFIG_NF_NAT_NEEDED
1335         if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1336                 return -EMSGSIZE;
1337 #endif
1338         nla_nest_end(skb, start);
1339
1340         return 0;
1341 }
1342
1343 void ovs_ct_free_action(const struct nlattr *a)
1344 {
1345         struct ovs_conntrack_info *ct_info = nla_data(a);
1346
1347         __ovs_ct_free_action(ct_info);
1348 }
1349
1350 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1351 {
1352         if (ct_info->helper)
1353                 module_put(ct_info->helper->me);
1354         if (ct_info->ct)
1355                 nf_ct_put(ct_info->ct);
1356 }
1357
1358 void ovs_ct_init(struct net *net)
1359 {
1360         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
1361         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1362
1363         if (nf_connlabels_get(net, n_bits - 1)) {
1364                 ovs_net->xt_label = false;
1365                 OVS_NLERR(true, "Failed to set connlabel length");
1366         } else {
1367                 ovs_net->xt_label = true;
1368         }
1369 }
1370
1371 void ovs_ct_exit(struct net *net)
1372 {
1373         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1374
1375         if (ovs_net->xt_label)
1376                 nf_connlabels_put(net);
1377 }