datapath/conntrack.c

   1 /*
   2  * Copyright (c) 2015 Nicira, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General Public
   6  * License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  */
  13
  14 #include <linux/kconfig.h>
  15 #include <linux/version.h>
  16
  17 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
  18
  19 #include <linux/module.h>
  20 #include <linux/openvswitch.h>
  21 #include <linux/tcp.h>
  22 #include <linux/udp.h>
  23 #include <linux/sctp.h>
  24 #include <net/ip.h>
  25 #include <net/netfilter/nf_conntrack_core.h>
  26 #include <net/netfilter/nf_conntrack_helper.h>
  27 #include <net/netfilter/nf_conntrack_labels.h>
  28 #include <net/netfilter/nf_conntrack_seqadj.h>
  29 #include <net/netfilter/nf_conntrack_zones.h>
  30 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  31
  32 #ifdef CONFIG_NF_NAT_NEEDED
  33 #include <linux/netfilter/nf_nat.h>
  34 #include <net/netfilter/nf_nat_core.h>
  35 #include <net/netfilter/nf_nat_l3proto.h>
  36 #endif
  37
  38 #include "datapath.h"
  39 #include "conntrack.h"
  40 #include "flow.h"
  41 #include "flow_netlink.h"
  42 #include "gso.h"
  43
  44 struct ovs_ct_len_tbl {
  45         int maxlen;
  46         int minlen;
  47 };
  48
  49 /* Metadata mark for masked write to conntrack mark */
  50 struct md_mark {
  51         u32 value;
  52         u32 mask;
  53 };
  54
  55 /* Metadata label for masked write to conntrack label. */
  56 struct md_labels {
  57         struct ovs_key_ct_labels value;
  58         struct ovs_key_ct_labels mask;
  59 };
  60
  61 enum ovs_ct_nat {
  62         OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
  63         OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
  64         OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
  65 };
  66
  67 /* Conntrack action context for execution. */
  68 struct ovs_conntrack_info {
  69         struct nf_conntrack_helper *helper;
  70         struct nf_conntrack_zone zone;
  71         struct nf_conn *ct;
  72         u8 commit : 1;
  73         u8 nat : 3;                 /* enum ovs_ct_nat */
  74         u16 family;
  75         struct md_mark mark;
  76         struct md_labels labels;
  77 #ifdef CONFIG_NF_NAT_NEEDED
  78         struct nf_nat_range range;  /* Only present for SRC NAT and DST NAT. */
  79 #endif
  80 };
  81
  82 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
  83
  84 static u16 key_to_nfproto(const struct sw_flow_key *key)
  85 {
  86         switch (ntohs(key->eth.type)) {
  87         case ETH_P_IP:
  88                 return NFPROTO_IPV4;
  89         case ETH_P_IPV6:
  90                 return NFPROTO_IPV6;
  91         default:
  92                 return NFPROTO_UNSPEC;
  93         }
  94 }
  95
  96 /* Map SKB connection state into the values used by flow definition. */
  97 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
  98 {
  99         u8 ct_state = OVS_CS_F_TRACKED;
 100
 101         switch (ctinfo) {
 102         case IP_CT_ESTABLISHED_REPLY:
 103         case IP_CT_RELATED_REPLY:
 104                 ct_state |= OVS_CS_F_REPLY_DIR;
 105                 break;
 106         default:
 107                 break;
 108         }
 109
 110         switch (ctinfo) {
 111         case IP_CT_ESTABLISHED:
 112         case IP_CT_ESTABLISHED_REPLY:
 113                 ct_state |= OVS_CS_F_ESTABLISHED;
 114                 break;
 115         case IP_CT_RELATED:
 116         case IP_CT_RELATED_REPLY:
 117                 ct_state |= OVS_CS_F_RELATED;
 118                 break;
 119         case IP_CT_NEW:
 120                 ct_state |= OVS_CS_F_NEW;
 121                 break;
 122         default:
 123                 break;
 124         }
 125
 126         return ct_state;
 127 }
 128
 129 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
 130 {
 131 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 132         return ct ? ct->mark : 0;
 133 #else
 134         return 0;
 135 #endif
 136 }
 137
 138 static void ovs_ct_get_labels(const struct nf_conn *ct,
 139                               struct ovs_key_ct_labels *labels)
 140 {
 141         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
 142
 143         if (cl) {
 144                 size_t len = cl->words * sizeof(long);
 145
 146                 if (len > OVS_CT_LABELS_LEN)
 147                         len = OVS_CT_LABELS_LEN;
 148                 else if (len < OVS_CT_LABELS_LEN)
 149                         memset(labels, 0, OVS_CT_LABELS_LEN);
 150                 memcpy(labels, cl->bits, len);
 151         } else {
 152                 memset(labels, 0, OVS_CT_LABELS_LEN);
 153         }
 154 }
 155
 156 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
 157                                 const struct nf_conntrack_zone *zone,
 158                                 const struct nf_conn *ct)
 159 {
 160         key->ct.state = state;
 161         key->ct.zone = zone->id;
 162         key->ct.mark = ovs_ct_get_mark(ct);
 163         ovs_ct_get_labels(ct, &key->ct.labels);
 164 }
 165
 166 /* Update 'key' based on skb->nfct.  If 'post_ct' is true, then OVS has
 167  * previously sent the packet to conntrack via the ct action.  If
 168  * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
 169  * initialized from the connection status.
 170  */
 171 static void ovs_ct_update_key(const struct sk_buff *skb,
 172                               const struct ovs_conntrack_info *info,
 173                               struct sw_flow_key *key, bool post_ct,
 174                               bool keep_nat_flags)
 175 {
 176         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 177         enum ip_conntrack_info ctinfo;
 178         struct nf_conn *ct;
 179         u8 state = 0;
 180
 181         ct = nf_ct_get(skb, &ctinfo);
 182         if (ct) {
 183                 state = ovs_ct_get_state(ctinfo);
 184                 /* All unconfirmed entries are NEW connections. */
 185                 if (!nf_ct_is_confirmed(ct))
 186                         state |= OVS_CS_F_NEW;
 187                 /* OVS persists the related flag for the duration of the
 188                  * connection.
 189                  */
 190                 if (ct->master)
 191                         state |= OVS_CS_F_RELATED;
 192                 if (keep_nat_flags) {
 193                         state |= key->ct.state & OVS_CS_F_NAT_MASK;
 194                 } else {
 195                         if (ct->status & IPS_SRC_NAT)
 196                                 state |= OVS_CS_F_SRC_NAT;
 197                         if (ct->status & IPS_DST_NAT)
 198                                 state |= OVS_CS_F_DST_NAT;
 199                 }
 200                 zone = nf_ct_zone(ct);
 201         } else if (post_ct) {
 202                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 203                 if (info)
 204                         zone = &info->zone;
 205         }
 206         __ovs_ct_update_key(key, state, zone, ct);
 207 }
 208
 209 /* This is called to initialize CT key fields possibly coming in from the local
 210  * stack.
 211  */
 212 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 213 {
 214         ovs_ct_update_key(skb, NULL, key, false, false);
 215 }
 216
 217 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
 218 {
 219         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
 220                 return -EMSGSIZE;
 221
 222         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 223             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
 224                 return -EMSGSIZE;
 225
 226         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 227             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
 228                 return -EMSGSIZE;
 229
 230         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 231             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
 232                     &key->ct.labels))
 233                 return -EMSGSIZE;
 234
 235         return 0;
 236 }
 237
 238 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
 239                            u32 ct_mark, u32 mask)
 240 {
 241 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 242         enum ip_conntrack_info ctinfo;
 243         struct nf_conn *ct;
 244         u32 new_mark;
 245
 246         /* The connection could be invalid, in which case set_mark is no-op. */
 247         ct = nf_ct_get(skb, &ctinfo);
 248         if (!ct)
 249                 return 0;
 250
 251         new_mark = ct_mark | (ct->mark & ~(mask));
 252         if (ct->mark != new_mark) {
 253                 ct->mark = new_mark;
 254                 nf_conntrack_event_cache(IPCT_MARK, ct);
 255                 key->ct.mark = new_mark;
 256         }
 257
 258         return 0;
 259 #else
 260         return -ENOTSUPP;
 261 #endif
 262 }
 263
 264 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
 265                              const struct ovs_key_ct_labels *labels,
 266                              const struct ovs_key_ct_labels *mask)
 267 {
 268         enum ip_conntrack_info ctinfo;
 269         struct nf_conn_labels *cl;
 270         struct nf_conn *ct;
 271         int err;
 272
 273         /* The connection could be invalid, in which case set_label is no-op.*/
 274         ct = nf_ct_get(skb, &ctinfo);
 275         if (!ct)
 276                 return 0;
 277
 278         cl = nf_ct_labels_find(ct);
 279         if (!cl) {
 280                 nf_ct_labels_ext_add(ct);
 281                 cl = nf_ct_labels_find(ct);
 282         }
 283         if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
 284                 return -ENOSPC;
 285
 286         err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
 287                                     OVS_CT_LABELS_LEN / sizeof(u32));
 288         if (err)
 289                 return err;
 290
 291         ovs_ct_get_labels(ct, &key->ct.labels);
 292         return 0;
 293 }
 294
 295 /* 'skb' should already be pulled to nh_ofs. */
 296 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 297 {
 298         const struct nf_conntrack_helper *helper;
 299         const struct nf_conn_help *help;
 300         enum ip_conntrack_info ctinfo;
 301         unsigned int protoff;
 302         struct nf_conn *ct;
 303         u8 nexthdr;
 304         int err;
 305
 306         ct = nf_ct_get(skb, &ctinfo);
 307         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 308                 return NF_ACCEPT;
 309
 310         help = nfct_help(ct);
 311         if (!help)
 312                 return NF_ACCEPT;
 313
 314         helper = rcu_dereference(help->helper);
 315         if (!helper)
 316                 return NF_ACCEPT;
 317
 318         switch (proto) {
 319         case NFPROTO_IPV4:
 320                 protoff = ip_hdrlen(skb);
 321                 break;
 322         case NFPROTO_IPV6: {
 323                 __be16 frag_off;
 324                 int ofs;
 325
 326                 nexthdr = ipv6_hdr(skb)->nexthdr;
 327                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 328                                        &frag_off);
 329                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 330                         pr_debug("proto header not found\n");
 331                         return NF_ACCEPT;
 332                 }
 333                 protoff = ofs;
 334                 break;
 335         }
 336         default:
 337                 WARN_ONCE(1, "helper invoked on non-IP family!");
 338                 return NF_DROP;
 339         }
 340
 341 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
 342         /* Linux 4.5 and older depend on skb_dst being set when recalculating
 343          * checksums after NAT helper has mangled TCP or UDP packet payload.
 344          * This dependency is avoided when skb is CHECKSUM_PARTIAL or when UDP
 345          * has no checksum.
 346          *
 347          * The dependency is not triggered when the main NAT code updates
 348          * checksums after translating the IP header (address, port), so this
 349          * fix only needs to be executed on packets that are both being NATted
 350          * and that have a helper assigned.
 351          */
 352         if (ct->status & IPS_NAT_MASK && skb->ip_summed != CHECKSUM_PARTIAL) {
 353                 u8 ipproto = (proto == NFPROTO_IPV4)
 354                         ? ip_hdr(skb)->protocol : nexthdr;
 355                 u16 offset = 0;
 356
 357                 switch (ipproto) {
 358                 case IPPROTO_TCP:
 359                         offset = offsetof(struct tcphdr, check);
 360                         break;
 361                 case IPPROTO_UDP:
 362                         /* Skip if no csum. */
 363                         if (udp_hdr(skb)->check)
 364                                 offset = offsetof(struct udphdr, check);
 365                         break;
 366                 }
 367                 if (offset) {
 368                         if (unlikely(!pskb_may_pull(skb, protoff + offset + 2)))
 369                                 return NF_DROP;
 370
 371                         skb->csum_start = skb_headroom(skb) + protoff;
 372                         skb->csum_offset = offset;
 373                         skb->ip_summed = CHECKSUM_PARTIAL;
 374                 }
 375         }
 376 #endif
 377         err = helper->help(skb, protoff, ct, ctinfo);
 378         if (err != NF_ACCEPT)
 379                 return err;
 380
 381         /* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
 382          * FTP with NAT) adusting the TCP payload size when mangling IP
 383          * addresses and/or port numbers in the text-based control connection.
 384          */
 385         if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
 386             !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
 387                 return NF_DROP;
 388         return NF_ACCEPT;
 389 }
 390
 391 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 392  * value if 'skb' is freed.
 393  */
 394 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 395                             u16 zone, struct sk_buff *skb)
 396 {
 397         struct ovs_gso_cb ovs_cb = *OVS_GSO_CB(skb);
 398         int err;
 399
 400         if (!skb->dev) {
 401                 OVS_NLERR(true, "%s: skb has no dev; dropping", __func__);
 402                 return -EINVAL;
 403         }
 404
 405         if (key->eth.type == htons(ETH_P_IP)) {
 406                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 407
 408                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 409                 err = ip_defrag(net, skb, user);
 410                 if (err)
 411                         return err;
 412
 413                 ovs_cb.dp_cb.mru = IPCB(skb)->frag_max_size;
 414 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 415         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 416                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 417
 418                 skb_orphan(skb);
 419                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 420                 err = nf_ct_frag6_gather(net, skb, user);
 421                 if (err)
 422                         return err;
 423
 424                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
 425                 ovs_cb.dp_cb.mru = IP6CB(skb)->frag_max_size;
 426 #endif /* IP frag support */
 427         } else {
 428                 kfree_skb(skb);
 429                 return -EPFNOSUPPORT;
 430         }
 431
 432         key->ip.frag = OVS_FRAG_TYPE_NONE;
 433         skb_clear_hash(skb);
 434         skb->ignore_df = 1;
 435         *OVS_GSO_CB(skb) = ovs_cb;
 436
 437         return 0;
 438 }
 439
 440 static struct nf_conntrack_expect *
 441 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 442                    u16 proto, const struct sk_buff *skb)
 443 {
 444         struct nf_conntrack_tuple tuple;
 445
 446         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
 447                 return NULL;
 448         return __nf_ct_expect_find(net, zone, &tuple);
 449 }
 450
 451 /* This replicates logic from nf_conntrack_core.c that is not exported. */
 452 static enum ip_conntrack_info
 453 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
 454 {
 455         const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 456
 457         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
 458                 return IP_CT_ESTABLISHED_REPLY;
 459         /* Once we've had two way comms, always ESTABLISHED. */
 460         if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 461                 return IP_CT_ESTABLISHED;
 462         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
 463                 return IP_CT_RELATED;
 464         return IP_CT_NEW;
 465 }
 466
 467 /* Find an existing connection which this packet belongs to without
 468  * re-attributing statistics or modifying the connection state.  This allows an
 469  * skb->nfct lost due to an upcall to be recovered during actions execution.
 470  *
 471  * Must be called with rcu_read_lock.
 472  *
 473  * On success, populates skb->nfct and skb->nfctinfo, and returns the
 474  * connection.  Returns NULL if there is no existing entry.
 475  */
 476 static struct nf_conn *
 477 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
 478                      u8 l3num, struct sk_buff *skb)
 479 {
 480         struct nf_conntrack_l3proto *l3proto;
 481         struct nf_conntrack_l4proto *l4proto;
 482         struct nf_conntrack_tuple tuple;
 483         struct nf_conntrack_tuple_hash *h;
 484         enum ip_conntrack_info ctinfo;
 485         struct nf_conn *ct;
 486         unsigned int dataoff;
 487         u8 protonum;
 488
 489         l3proto = __nf_ct_l3proto_find(l3num);
 490         if (!l3proto) {
 491                 pr_debug("ovs_ct_find_existing: Can't get l3proto\n");
 492                 return NULL;
 493         }
 494         if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff,
 495                                  &protonum) <= 0) {
 496                 pr_debug("ovs_ct_find_existing: Can't get protonum\n");
 497                 return NULL;
 498         }
 499         l4proto = __nf_ct_l4proto_find(l3num, protonum);
 500         if (!l4proto) {
 501                 pr_debug("ovs_ct_find_existing: Can't get l4proto\n");
 502                 return NULL;
 503         }
 504         if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
 505                              protonum, net, &tuple, l3proto, l4proto)) {
 506                 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
 507                 return NULL;
 508         }
 509
 510         /* look for tuple match */
 511         h = nf_conntrack_find_get(net, zone, &tuple);
 512         if (!h)
 513                 return NULL;   /* Not found. */
 514
 515         ct = nf_ct_tuplehash_to_ctrack(h);
 516
 517         ctinfo = ovs_ct_get_info(h);
 518         if (ctinfo == IP_CT_NEW) {
 519                 /* This should not happen. */
 520                 WARN_ONCE(1, "ovs_ct_find_existing: new packet for %p\n", ct);
 521         }
 522         skb->nfct = &ct->ct_general;
 523         skb->nfctinfo = ctinfo;
 524         return ct;
 525 }
 526
 527 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
 528 static bool skb_nfct_cached(struct net *net,
 529                             const struct sw_flow_key *key,
 530                             const struct ovs_conntrack_info *info,
 531                             struct sk_buff *skb)
 532 {
 533         enum ip_conntrack_info ctinfo;
 534         struct nf_conn *ct;
 535
 536         ct = nf_ct_get(skb, &ctinfo);
 537         /* If no ct, check if we have evidence that an existing conntrack entry
 538          * might be found for this skb.  This happens when we lose a skb->nfct
 539          * due to an upcall.  If the connection was not confirmed, it is not
 540          * cached and needs to be run through conntrack again.
 541          */
 542         if (!ct && key->ct.state & OVS_CS_F_TRACKED &&
 543             !(key->ct.state & OVS_CS_F_INVALID) &&
 544             key->ct.zone == info->zone.id)
 545                 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb);
 546         if (!ct)
 547                 return false;
 548         if (!net_eq(net, read_pnet(&ct->ct_net)))
 549                 return false;
 550         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 551                 return false;
 552         if (info->helper) {
 553                 struct nf_conn_help *help;
 554
 555                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 556                 if (help && rcu_access_pointer(help->helper) != info->helper)
 557                         return false;
 558         }
 559
 560         return true;
 561 }
 562
 563 #ifdef CONFIG_NF_NAT_NEEDED
 564 /* Modelled after nf_nat_ipv[46]_fn().
 565  * range is only used for new, uninitialized NAT state.
 566  * Returns either NF_ACCEPT or NF_DROP.
 567  */
 568 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 569                               enum ip_conntrack_info ctinfo,
 570                               const struct nf_nat_range *range,
 571                               enum nf_nat_manip_type maniptype)
 572 {
 573         int hooknum, nh_off, err = NF_ACCEPT;
 574
 575         nh_off = skb_network_offset(skb);
 576         skb_pull(skb, nh_off);
 577
 578         /* See HOOK2MANIP(). */
 579         if (maniptype == NF_NAT_MANIP_SRC)
 580                 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
 581         else
 582                 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
 583
 584         switch (ctinfo) {
 585         case IP_CT_RELATED:
 586         case IP_CT_RELATED_REPLY:
 587                 if (skb->protocol == htons(ETH_P_IP) &&
 588                     ip_hdr(skb)->protocol == IPPROTO_ICMP) {
 589                         if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
 590                                                            hooknum))
 591                                 err = NF_DROP;
 592                         goto push;
 593 #if IS_ENABLED(CONFIG_NF_NAT_IPV6)
 594                 } else if (skb->protocol == htons(ETH_P_IPV6)) {
 595                         __be16 frag_off;
 596                         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 597                         int hdrlen = ipv6_skip_exthdr(skb,
 598                                                       sizeof(struct ipv6hdr),
 599                                                       &nexthdr, &frag_off);
 600
 601                         if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
 602                                 if (!nf_nat_icmpv6_reply_translation(skb, ct,
 603                                                                      ctinfo,
 604                                                                      hooknum,
 605                                                                      hdrlen))
 606                                         err = NF_DROP;
 607                                 goto push;
 608                         }
 609 #endif
 610                 }
 611                 /* Non-ICMP, fall thru to initialize if needed. */
 612         case IP_CT_NEW:
 613                 /* Seen it before?  This can happen for loopback, retrans,
 614                  * or local packets.
 615                  */
 616                 if (!nf_nat_initialized(ct, maniptype)) {
 617                         /* Initialize according to the NAT action. */
 618                         err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
 619                                 /* Action is set up to establish a new
 620                                  * mapping.
 621                                  */
 622                                 ? nf_nat_setup_info(ct, range, maniptype)
 623                                 : nf_nat_alloc_null_binding(ct, hooknum);
 624                         if (err != NF_ACCEPT)
 625                                 goto push;
 626                 }
 627                 break;
 628
 629         case IP_CT_ESTABLISHED:
 630         case IP_CT_ESTABLISHED_REPLY:
 631                 break;
 632
 633         default:
 634                 err = NF_DROP;
 635                 goto push;
 636         }
 637
 638         err = nf_nat_packet(ct, ctinfo, hooknum, skb);
 639 push:
 640         skb_push(skb, nh_off);
 641
 642         return err;
 643 }
 644
 645 static void ovs_nat_update_key(struct sw_flow_key *key,
 646                                const struct sk_buff *skb,
 647                                enum nf_nat_manip_type maniptype)
 648 {
 649         if (maniptype == NF_NAT_MANIP_SRC) {
 650                 __be16 src;
 651
 652                 key->ct.state |= OVS_CS_F_SRC_NAT;
 653                 if (key->eth.type == htons(ETH_P_IP))
 654                         key->ipv4.addr.src = ip_hdr(skb)->saddr;
 655                 else if (key->eth.type == htons(ETH_P_IPV6))
 656                         memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
 657                                sizeof(key->ipv6.addr.src));
 658                 else
 659                         return;
 660
 661                 if (key->ip.proto == IPPROTO_UDP)
 662                         src = udp_hdr(skb)->source;
 663                 else if (key->ip.proto == IPPROTO_TCP)
 664                         src = tcp_hdr(skb)->source;
 665                 else if (key->ip.proto == IPPROTO_SCTP)
 666                         src = sctp_hdr(skb)->source;
 667                 else
 668                         return;
 669
 670                 key->tp.src = src;
 671         } else {
 672                 __be16 dst;
 673
 674                 key->ct.state |= OVS_CS_F_DST_NAT;
 675                 if (key->eth.type == htons(ETH_P_IP))
 676                         key->ipv4.addr.dst = ip_hdr(skb)->daddr;
 677                 else if (key->eth.type == htons(ETH_P_IPV6))
 678                         memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
 679                                sizeof(key->ipv6.addr.dst));
 680                 else
 681                         return;
 682
 683                 if (key->ip.proto == IPPROTO_UDP)
 684                         dst = udp_hdr(skb)->dest;
 685                 else if (key->ip.proto == IPPROTO_TCP)
 686                         dst = tcp_hdr(skb)->dest;
 687                 else if (key->ip.proto == IPPROTO_SCTP)
 688                         dst = sctp_hdr(skb)->dest;
 689                 else
 690                         return;
 691
 692                 key->tp.dst = dst;
 693         }
 694 }
 695
 696 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
 697 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 698                       const struct ovs_conntrack_info *info,
 699                       struct sk_buff *skb, struct nf_conn *ct,
 700                       enum ip_conntrack_info ctinfo)
 701 {
 702         enum nf_nat_manip_type maniptype;
 703         int err;
 704
 705         if (nf_ct_is_untracked(ct)) {
 706                 /* A NAT action may only be performed on tracked packets. */
 707                 return NF_ACCEPT;
 708         }
 709
 710         /* Add NAT extension if not confirmed yet. */
 711         if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
 712                 return NF_ACCEPT;   /* Can't NAT. */
 713
 714         /* Determine NAT type.
 715          * Check if the NAT type can be deduced from the tracked connection.
 716          * Make sure expected traffic is NATted only when committing.
 717          */
 718         if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
 719             ct->status & IPS_NAT_MASK &&
 720             (!(ct->status & IPS_EXPECTED_BIT) || info->commit)) {
 721                 /* NAT an established or related connection like before. */
 722                 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
 723                         /* This is the REPLY direction for a connection
 724                          * for which NAT was applied in the forward
 725                          * direction.  Do the reverse NAT.
 726                          */
 727                         maniptype = ct->status & IPS_SRC_NAT
 728                                 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
 729                 else
 730                         maniptype = ct->status & IPS_SRC_NAT
 731                                 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
 732         } else if (info->nat & OVS_CT_SRC_NAT) {
 733                 maniptype = NF_NAT_MANIP_SRC;
 734         } else if (info->nat & OVS_CT_DST_NAT) {
 735                 maniptype = NF_NAT_MANIP_DST;
 736         } else {
 737                 return NF_ACCEPT; /* Connection is not NATed. */
 738         }
 739         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
 740
 741         /* Mark NAT done if successful and update the flow key. */
 742         if (err == NF_ACCEPT)
 743                 ovs_nat_update_key(key, skb, maniptype);
 744
 745         return err;
 746 }
 747 #else /* !CONFIG_NF_NAT_NEEDED */
 748 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 749                       const struct ovs_conntrack_info *info,
 750                       struct sk_buff *skb, struct nf_conn *ct,
 751                       enum ip_conntrack_info ctinfo)
 752 {
 753         return NF_ACCEPT;
 754 }
 755 #endif
 756
 757 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
 758  * not done already.  Update key with new CT state after passing the packet
 759  * through conntrack.
 760  * Note that if the packet is deemed invalid by conntrack, skb->nfct will be
 761  * set to NULL and 0 will be returned.
 762  */
 763 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 764                            const struct ovs_conntrack_info *info,
 765                            struct sk_buff *skb)
 766 {
 767         /* If we are recirculating packets to match on conntrack fields and
 768          * committing with a separate conntrack action,  then we don't need to
 769          * actually run the packet through conntrack twice unless it's for a
 770          * different zone.
 771          */
 772         bool cached = skb_nfct_cached(net, key, info, skb);
 773         enum ip_conntrack_info ctinfo;
 774         struct nf_conn *ct;
 775
 776         if (!cached) {
 777                 struct nf_conn *tmpl = info->ct;
 778                 int err;
 779
 780                 /* Associate skb with specified zone. */
 781                 if (tmpl) {
 782                         if (skb->nfct)
 783                                 nf_conntrack_put(skb->nfct);
 784                         nf_conntrack_get(&tmpl->ct_general);
 785                         skb->nfct = &tmpl->ct_general;
 786                         skb->nfctinfo = IP_CT_NEW;
 787                 }
 788
 789                 /* Repeat if requested, see nf_iterate(). */
 790                 do {
 791                         err = nf_conntrack_in(net, info->family,
 792                                               NF_INET_FORWARD, skb);
 793                 } while (err == NF_REPEAT);
 794
 795                 if (err != NF_ACCEPT)
 796                         return -ENOENT;
 797
 798                 /* Clear CT state NAT flags to mark that we have not yet done
 799                  * NAT after the nf_conntrack_in() call.  We can actually clear
 800                  * the whole state, as it will be re-initialized below.
 801                  */
 802                 key->ct.state = 0;
 803
 804                 /* Update the key, but keep the NAT flags. */
 805                 ovs_ct_update_key(skb, info, key, true, true);
 806         }
 807
 808         ct = nf_ct_get(skb, &ctinfo);
 809         if (ct) {
 810                 /* Packets starting a new connection must be NATted before the
 811                  * helper, so that the helper knows about the NAT.  We enforce
 812                  * this by delaying both NAT and helper calls for unconfirmed
 813                  * connections until the committing CT action.  For later
 814                  * packets NAT and Helper may be called in either order.
 815                  *
 816                  * NAT will be done only if the CT action has NAT, and only
 817                  * once per packet (per zone), as guarded by the NAT bits in
 818                  * the key->ct.state.
 819                  */
 820                 if (info->nat && !(key->ct.state & OVS_CS_F_NAT_MASK) &&
 821                     (nf_ct_is_confirmed(ct) || info->commit) &&
 822                     ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
 823                         return -EINVAL;
 824                 }
 825
 826                 /* Call the helper only if:
 827                  * - nf_conntrack_in() was executed above ("!cached") for a
 828                  *   confirmed connection, or
 829                  * - When committing an unconfirmed connection.
 830                  */
 831                 if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
 832                     ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 833                         return -EINVAL;
 834                 }
 835         }
 836
 837         return 0;
 838 }
 839
 840 /* Lookup connection and read fields into key. */
 841 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 842                          const struct ovs_conntrack_info *info,
 843                          struct sk_buff *skb)
 844 {
 845         struct nf_conntrack_expect *exp;
 846
 847         /* If we pass an expected packet through nf_conntrack_in() the
 848          * expectation is typically removed, but the packet could still be
 849          * lost in upcall processing.  To prevent this from happening we
 850          * perform an explicit expectation lookup.  Expected connections are
 851          * always new, and will be passed through conntrack only when they are
 852          * committed, as it is OK to remove the expectation at that time.
 853          */
 854         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
 855         if (exp) {
 856                 u8 state;
 857
 858                 /* NOTE: New connections are NATted and Helped only when
 859                  * committed, so we are not calling into NAT here.
 860                  */
 861                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
 862                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
 863         } else
 864                 return __ovs_ct_lookup(net, key, info, skb);
 865
 866         return 0;
 867 }
 868
 869 /* Lookup connection and confirm if unconfirmed. */
 870 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
 871                          const struct ovs_conntrack_info *info,
 872                          struct sk_buff *skb)
 873 {
 874         int err;
 875
 876         err = __ovs_ct_lookup(net, key, info, skb);
 877         if (err)
 878                 return err;
 879         /* This is a no-op if the connection has already been confirmed. */
 880         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
 881                 return -EINVAL;
 882
 883         return 0;
 884 }
 885
 886 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
 887 {
 888         size_t i;
 889
 890         for (i = 0; i < sizeof(*labels); i++)
 891                 if (labels->ct_labels[i])
 892                         return true;
 893
 894         return false;
 895 }
 896
 897 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 898  * value if 'skb' is freed.
 899  */
 900 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
 901                    struct sw_flow_key *key,
 902                    const struct ovs_conntrack_info *info)
 903 {
 904         int nh_ofs;
 905         int err;
 906
 907         /* The conntrack module expects to be working at L3. */
 908         nh_ofs = skb_network_offset(skb);
 909         skb_pull(skb, nh_ofs);
 910
 911         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
 912                 err = handle_fragments(net, key, info->zone.id, skb);
 913                 if (err)
 914                         return err;
 915         }
 916
 917         if (info->commit)
 918                 err = ovs_ct_commit(net, key, info, skb);
 919         else
 920                 err = ovs_ct_lookup(net, key, info, skb);
 921         if (err)
 922                 goto err;
 923
 924         if (info->mark.mask) {
 925                 err = ovs_ct_set_mark(skb, key, info->mark.value,
 926                                       info->mark.mask);
 927                 if (err)
 928                         goto err;
 929         }
 930         if (labels_nonzero(&info->labels.mask))
 931                 err = ovs_ct_set_labels(skb, key, &info->labels.value,
 932                                         &info->labels.mask);
 933 err:
 934         skb_push(skb, nh_ofs);
 935         if (err)
 936                 kfree_skb(skb);
 937         return err;
 938 }
 939
 940 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 941                              const struct sw_flow_key *key, bool log)
 942 {
 943         struct nf_conntrack_helper *helper;
 944         struct nf_conn_help *help;
 945
 946         helper = nf_conntrack_helper_try_module_get(name, info->family,
 947                                                     key->ip.proto);
 948         if (!helper) {
 949                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
 950                 return -EINVAL;
 951         }
 952
 953         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
 954         if (!help) {
 955                 module_put(helper->me);
 956                 return -ENOMEM;
 957         }
 958
 959         rcu_assign_pointer(help->helper, helper);
 960         info->helper = helper;
 961         return 0;
 962 }
 963
 964 #ifdef CONFIG_NF_NAT_NEEDED
 965 static int parse_nat(const struct nlattr *attr,
 966                      struct ovs_conntrack_info *info, bool log)
 967 {
 968         struct nlattr *a;
 969         int rem;
 970         bool have_ip_max = false;
 971         bool have_proto_max = false;
 972         bool ip_vers = (info->family == NFPROTO_IPV6);
 973
 974         nla_for_each_nested(a, attr, rem) {
 975                 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
 976                         [OVS_NAT_ATTR_SRC] = {0, 0},
 977                         [OVS_NAT_ATTR_DST] = {0, 0},
 978                         [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
 979                                                  sizeof(struct in6_addr)},
 980                         [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
 981                                                  sizeof(struct in6_addr)},
 982                         [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
 983                         [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
 984                         [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
 985                         [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
 986                         [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
 987                 };
 988                 int type = nla_type(a);
 989
 990                 if (type > OVS_NAT_ATTR_MAX) {
 991                         OVS_NLERR(log,
 992                                   "Unknown NAT attribute (type=%d, max=%d).\n",
 993                                   type, OVS_NAT_ATTR_MAX);
 994                         return -EINVAL;
 995                 }
 996
 997                 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
 998                         OVS_NLERR(log,
 999                                   "NAT attribute type %d has unexpected length (%d != %d).\n",
1000                                   type, nla_len(a),
1001                                   ovs_nat_attr_lens[type][ip_vers]);
1002                         return -EINVAL;
1003                 }
1004
1005                 switch (type) {
1006                 case OVS_NAT_ATTR_SRC:
1007                 case OVS_NAT_ATTR_DST:
1008                         if (info->nat) {
1009                                 OVS_NLERR(log,
1010                                           "Only one type of NAT may be specified.\n"
1011                                           );
1012                                 return -ERANGE;
1013                         }
1014                         info->nat |= OVS_CT_NAT;
1015                         info->nat |= ((type == OVS_NAT_ATTR_SRC)
1016                                         ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1017                         break;
1018
1019                 case OVS_NAT_ATTR_IP_MIN:
1020                         nla_memcpy(&info->range.min_addr, a, nla_len(a));
1021                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1022                         break;
1023
1024                 case OVS_NAT_ATTR_IP_MAX:
1025                         have_ip_max = true;
1026                         nla_memcpy(&info->range.max_addr, a,
1027                                    sizeof(info->range.max_addr));
1028                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1029                         break;
1030
1031                 case OVS_NAT_ATTR_PROTO_MIN:
1032                         info->range.min_proto.all = htons(nla_get_u16(a));
1033                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1034                         break;
1035
1036                 case OVS_NAT_ATTR_PROTO_MAX:
1037                         have_proto_max = true;
1038                         info->range.max_proto.all = htons(nla_get_u16(a));
1039                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1040                         break;
1041
1042                 case OVS_NAT_ATTR_PERSISTENT:
1043                         info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1044                         break;
1045
1046                 case OVS_NAT_ATTR_PROTO_HASH:
1047                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1048                         break;
1049
1050                 case OVS_NAT_ATTR_PROTO_RANDOM:
1051                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1052                         break;
1053
1054                 default:
1055                         OVS_NLERR(log, "Unknown nat attribute (%d).\n", type);
1056                         return -EINVAL;
1057                 }
1058         }
1059
1060         if (rem > 0) {
1061                 OVS_NLERR(log, "NAT attribute has %d unknown bytes.\n", rem);
1062                 return -EINVAL;
1063         }
1064         if (!info->nat) {
1065                 /* Do not allow flags if no type is given. */
1066                 if (info->range.flags) {
1067                         OVS_NLERR(log,
1068                                   "NAT flags may be given only when NAT range (SRC or DST) is also specified.\n"
1069                                   );
1070                         return -EINVAL;
1071                 }
1072                 info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1073         } else if (!info->commit) {
1074                 OVS_NLERR(log,
1075                           "NAT attributes may be specified only when CT COMMIT flag is also specified.\n"
1076                           );
1077                 return -EINVAL;
1078         }
1079         /* Allow missing IP_MAX. */
1080         if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1081                 memcpy(&info->range.max_addr, &info->range.min_addr,
1082                        sizeof(info->range.max_addr));
1083         }
1084         /* Allow missing PROTO_MAX. */
1085         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1086             !have_proto_max) {
1087                 info->range.max_proto.all = info->range.min_proto.all;
1088         }
1089         return 0;
1090 }
1091 #endif
1092
1093 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1094         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
1095         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
1096                                     .maxlen = sizeof(u16) },
1097         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
1098                                     .maxlen = sizeof(struct md_mark) },
1099         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
1100                                     .maxlen = sizeof(struct md_labels) },
1101         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
1102                                     .maxlen = NF_CT_HELPER_NAME_LEN },
1103 #ifdef CONFIG_NF_NAT_NEEDED
1104         /* NAT length is checked when parsing the nested attributes. */
1105         [OVS_CT_ATTR_NAT]       = { .minlen = 0, .maxlen = INT_MAX },
1106 #endif
1107 };
1108
1109 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1110                     const char **helper, bool log)
1111 {
1112         struct nlattr *a;
1113         int rem;
1114
1115         nla_for_each_nested(a, attr, rem) {
1116                 int type = nla_type(a);
1117                 int maxlen = ovs_ct_attr_lens[type].maxlen;
1118                 int minlen = ovs_ct_attr_lens[type].minlen;
1119
1120                 if (type > OVS_CT_ATTR_MAX) {
1121                         OVS_NLERR(log,
1122                                   "Unknown conntrack attr (type=%d, max=%d)",
1123                                   type, OVS_CT_ATTR_MAX);
1124                         return -EINVAL;
1125                 }
1126                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1127                         OVS_NLERR(log,
1128                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1129                                   type, nla_len(a), maxlen);
1130                         return -EINVAL;
1131                 }
1132
1133                 switch (type) {
1134                 case OVS_CT_ATTR_COMMIT:
1135                         info->commit = true;
1136                         break;
1137 #ifdef CONFIG_NF_CONNTRACK_ZONES
1138                 case OVS_CT_ATTR_ZONE:
1139                         info->zone.id = nla_get_u16(a);
1140                         break;
1141 #endif
1142 #ifdef CONFIG_NF_CONNTRACK_MARK
1143                 case OVS_CT_ATTR_MARK: {
1144                         struct md_mark *mark = nla_data(a);
1145
1146                         if (!mark->mask) {
1147                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
1148                                 return -EINVAL;
1149                         }
1150                         info->mark = *mark;
1151                         break;
1152                 }
1153 #endif
1154 #ifdef CONFIG_NF_CONNTRACK_LABELS
1155                 case OVS_CT_ATTR_LABELS: {
1156                         struct md_labels *labels = nla_data(a);
1157
1158                         if (!labels_nonzero(&labels->mask)) {
1159                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
1160                                 return -EINVAL;
1161                         }
1162                         info->labels = *labels;
1163                         break;
1164                 }
1165 #endif
1166                 case OVS_CT_ATTR_HELPER:
1167                         *helper = nla_data(a);
1168                         if (!memchr(*helper, '\0', nla_len(a))) {
1169                                 OVS_NLERR(log, "Invalid conntrack helper");
1170                                 return -EINVAL;
1171                         }
1172                         break;
1173 #ifdef CONFIG_NF_NAT_NEEDED
1174                 case OVS_CT_ATTR_NAT: {
1175                         int err = parse_nat(a, info, log);
1176
1177                         if (err)
1178                                 return err;
1179                         break;
1180                 }
1181 #endif
1182                 default:
1183                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
1184                                   type);
1185                         return -EINVAL;
1186                 }
1187         }
1188
1189         if (rem > 0) {
1190                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1191                 return -EINVAL;
1192         }
1193
1194         return 0;
1195 }
1196
1197 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1198 {
1199         if (attr == OVS_KEY_ATTR_CT_STATE)
1200                 return true;
1201         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1202             attr == OVS_KEY_ATTR_CT_ZONE)
1203                 return true;
1204         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1205             attr == OVS_KEY_ATTR_CT_MARK)
1206                 return true;
1207         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1208             attr == OVS_KEY_ATTR_CT_LABELS) {
1209                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1210
1211                 return ovs_net->xt_label;
1212         }
1213
1214         return false;
1215 }
1216
1217 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1218                        const struct sw_flow_key *key,
1219                        struct sw_flow_actions **sfa,  bool log)
1220 {
1221         struct ovs_conntrack_info ct_info;
1222         const char *helper = NULL;
1223         u16 family;
1224         int err;
1225
1226         family = key_to_nfproto(key);
1227         if (family == NFPROTO_UNSPEC) {
1228                 OVS_NLERR(log, "ct family unspecified");
1229                 return -EINVAL;
1230         }
1231
1232         memset(&ct_info, 0, sizeof(ct_info));
1233         ct_info.family = family;
1234
1235         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1236                         NF_CT_DEFAULT_ZONE_DIR, 0);
1237
1238         err = parse_ct(attr, &ct_info, &helper, log);
1239         if (err)
1240                 return err;
1241
1242         /* Set up template for tracking connections in specific zones. */
1243         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1244         if (!ct_info.ct) {
1245                 OVS_NLERR(log, "Failed to allocate conntrack template");
1246                 return -ENOMEM;
1247         }
1248
1249         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1250         nf_conntrack_get(&ct_info.ct->ct_general);
1251
1252         if (helper) {
1253                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1254                 if (err)
1255                         goto err_free_ct;
1256         }
1257
1258         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1259                                  sizeof(ct_info), log);
1260         if (err)
1261                 goto err_free_ct;
1262
1263         return 0;
1264 err_free_ct:
1265         __ovs_ct_free_action(&ct_info);
1266         return err;
1267 }
1268
1269 #ifdef CONFIG_NF_NAT_NEEDED
1270 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1271                                struct sk_buff *skb)
1272 {
1273         struct nlattr *start;
1274
1275         start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1276         if (!start)
1277                 return false;
1278
1279         if (info->nat & OVS_CT_SRC_NAT) {
1280                 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1281                         return false;
1282         } else if (info->nat & OVS_CT_DST_NAT) {
1283                 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1284                         return false;
1285         } else {
1286                 goto out;
1287         }
1288
1289         if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1290                 if (info->family == NFPROTO_IPV4) {
1291                         if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1292                                             info->range.min_addr.ip) ||
1293                             (info->range.max_addr.ip
1294                              != info->range.min_addr.ip &&
1295                              (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1296                                               info->range.max_addr.ip))))
1297                                 return false;
1298 #if IS_ENABLED(CONFIG_NF_NAT_IPV6)
1299                 } else if (info->family == NFPROTO_IPV6) {
1300                         if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1301                                              &info->range.min_addr.in6) ||
1302                             (memcmp(&info->range.max_addr.in6,
1303                                     &info->range.min_addr.in6,
1304                                     sizeof(info->range.max_addr.in6)) &&
1305                              (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1306                                                &info->range.max_addr.in6))))
1307                                 return false;
1308 #endif
1309                 } else {
1310                         return false;
1311                 }
1312         }
1313         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1314             (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1315                          ntohs(info->range.min_proto.all)) ||
1316              (info->range.max_proto.all != info->range.min_proto.all &&
1317               nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1318                           ntohs(info->range.max_proto.all)))))
1319                 return false;
1320
1321         if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1322             nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1323                 return false;
1324         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1325             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1326                 return false;
1327         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1328             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1329                 return false;
1330 out:
1331         nla_nest_end(skb, start);
1332
1333         return true;
1334 }
1335 #endif
1336
1337 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1338                           struct sk_buff *skb)
1339 {
1340         struct nlattr *start;
1341
1342         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1343         if (!start)
1344                 return -EMSGSIZE;
1345
1346         if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
1347                 return -EMSGSIZE;
1348         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1349             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1350                 return -EMSGSIZE;
1351         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1352             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1353                     &ct_info->mark))
1354                 return -EMSGSIZE;
1355         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1356             labels_nonzero(&ct_info->labels.mask) &&
1357             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1358                     &ct_info->labels))
1359                 return -EMSGSIZE;
1360         if (ct_info->helper) {
1361                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1362                                    ct_info->helper->name))
1363                         return -EMSGSIZE;
1364         }
1365 #ifdef CONFIG_NF_NAT_NEEDED
1366         if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1367                 return -EMSGSIZE;
1368 #endif
1369         nla_nest_end(skb, start);
1370
1371         return 0;
1372 }
1373
1374 void ovs_ct_free_action(const struct nlattr *a)
1375 {
1376         struct ovs_conntrack_info *ct_info = nla_data(a);
1377
1378         __ovs_ct_free_action(ct_info);
1379 }
1380
1381 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1382 {
1383         if (ct_info->helper)
1384                 module_put(ct_info->helper->me);
1385         if (ct_info->ct)
1386                 nf_ct_tmpl_free(ct_info->ct);
1387 }
1388
1389 void ovs_ct_init(struct net *net)
1390 {
1391         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
1392         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1393
1394         if (nf_connlabels_get(net, n_bits)) {
1395                 ovs_net->xt_label = false;
1396                 OVS_NLERR(true, "Failed to set connlabel length");
1397         } else {
1398                 ovs_net->xt_label = true;
1399         }
1400 }
1401
1402 void ovs_ct_exit(struct net *net)
1403 {
1404         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1405
1406         if (ovs_net->xt_label)
1407                 nf_connlabels_put(net);
1408 }
1409
1410 #endif /* CONFIG_NF_CONNTRACK */