net/openvswitch/conntrack.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015 Nicira, Inc.
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/openvswitch.h>
   8 #include <linux/tcp.h>
   9 #include <linux/udp.h>
  10 #include <linux/sctp.h>
  11 #include <linux/static_key.h>
  12 #include <net/ip.h>
  13 #include <net/genetlink.h>
  14 #include <net/netfilter/nf_conntrack_core.h>
  15 #include <net/netfilter/nf_conntrack_count.h>
  16 #include <net/netfilter/nf_conntrack_helper.h>
  17 #include <net/netfilter/nf_conntrack_labels.h>
  18 #include <net/netfilter/nf_conntrack_seqadj.h>
  19 #include <net/netfilter/nf_conntrack_timeout.h>
  20 #include <net/netfilter/nf_conntrack_zones.h>
  21 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  22 #include <net/ipv6_frag.h>
  23
  24 #if IS_ENABLED(CONFIG_NF_NAT)
  25 #include <net/netfilter/nf_nat.h>
  26 #endif
  27
  28 #include "datapath.h"
  29 #include "conntrack.h"
  30 #include "flow.h"
  31 #include "flow_netlink.h"
  32
  33 struct ovs_ct_len_tbl {
  34         int maxlen;
  35         int minlen;
  36 };
  37
  38 /* Metadata mark for masked write to conntrack mark */
  39 struct md_mark {
  40         u32 value;
  41         u32 mask;
  42 };
  43
  44 /* Metadata label for masked write to conntrack label. */
  45 struct md_labels {
  46         struct ovs_key_ct_labels value;
  47         struct ovs_key_ct_labels mask;
  48 };
  49
  50 enum ovs_ct_nat {
  51         OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
  52         OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
  53         OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
  54 };
  55
  56 /* Conntrack action context for execution. */
  57 struct ovs_conntrack_info {
  58         struct nf_conntrack_helper *helper;
  59         struct nf_conntrack_zone zone;
  60         struct nf_conn *ct;
  61         u8 commit : 1;
  62         u8 nat : 3;                 /* enum ovs_ct_nat */
  63         u8 force : 1;
  64         u8 have_eventmask : 1;
  65         u16 family;
  66         u32 eventmask;              /* Mask of 1 << IPCT_*. */
  67         struct md_mark mark;
  68         struct md_labels labels;
  69         char timeout[CTNL_TIMEOUT_NAME_MAX];
  70         struct nf_ct_timeout *nf_ct_timeout;
  71 #if IS_ENABLED(CONFIG_NF_NAT)
  72         struct nf_nat_range2 range;  /* Only present for SRC NAT and DST NAT. */
  73 #endif
  74 };
  75
  76 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
  77 #define OVS_CT_LIMIT_UNLIMITED  0
  78 #define OVS_CT_LIMIT_DEFAULT OVS_CT_LIMIT_UNLIMITED
  79 #define CT_LIMIT_HASH_BUCKETS 512
  80 static DEFINE_STATIC_KEY_FALSE(ovs_ct_limit_enabled);
  81
  82 struct ovs_ct_limit {
  83         /* Elements in ovs_ct_limit_info->limits hash table */
  84         struct hlist_node hlist_node;
  85         struct rcu_head rcu;
  86         u16 zone;
  87         u32 limit;
  88 };
  89
  90 struct ovs_ct_limit_info {
  91         u32 default_limit;
  92         struct hlist_head *limits;
  93         struct nf_conncount_data *data;
  94 };
  95
  96 static const struct nla_policy ct_limit_policy[OVS_CT_LIMIT_ATTR_MAX + 1] = {
  97         [OVS_CT_LIMIT_ATTR_ZONE_LIMIT] = { .type = NLA_NESTED, },
  98 };
  99 #endif
 100
 101 static bool labels_nonzero(const struct ovs_key_ct_labels *labels);
 102
 103 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
 104
 105 static u16 key_to_nfproto(const struct sw_flow_key *key)
 106 {
 107         switch (ntohs(key->eth.type)) {
 108         case ETH_P_IP:
 109                 return NFPROTO_IPV4;
 110         case ETH_P_IPV6:
 111                 return NFPROTO_IPV6;
 112         default:
 113                 return NFPROTO_UNSPEC;
 114         }
 115 }
 116
 117 /* Map SKB connection state into the values used by flow definition. */
 118 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
 119 {
 120         u8 ct_state = OVS_CS_F_TRACKED;
 121
 122         switch (ctinfo) {
 123         case IP_CT_ESTABLISHED_REPLY:
 124         case IP_CT_RELATED_REPLY:
 125                 ct_state |= OVS_CS_F_REPLY_DIR;
 126                 break;
 127         default:
 128                 break;
 129         }
 130
 131         switch (ctinfo) {
 132         case IP_CT_ESTABLISHED:
 133         case IP_CT_ESTABLISHED_REPLY:
 134                 ct_state |= OVS_CS_F_ESTABLISHED;
 135                 break;
 136         case IP_CT_RELATED:
 137         case IP_CT_RELATED_REPLY:
 138                 ct_state |= OVS_CS_F_RELATED;
 139                 break;
 140         case IP_CT_NEW:
 141                 ct_state |= OVS_CS_F_NEW;
 142                 break;
 143         default:
 144                 break;
 145         }
 146
 147         return ct_state;
 148 }
 149
 150 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
 151 {
 152 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 153         return ct ? ct->mark : 0;
 154 #else
 155         return 0;
 156 #endif
 157 }
 158
 159 /* Guard against conntrack labels max size shrinking below 128 bits. */
 160 #if NF_CT_LABELS_MAX_SIZE < 16
 161 #error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes
 162 #endif
 163
 164 static void ovs_ct_get_labels(const struct nf_conn *ct,
 165                               struct ovs_key_ct_labels *labels)
 166 {
 167         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
 168
 169         if (cl)
 170                 memcpy(labels, cl->bits, OVS_CT_LABELS_LEN);
 171         else
 172                 memset(labels, 0, OVS_CT_LABELS_LEN);
 173 }
 174
 175 static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key,
 176                                         const struct nf_conntrack_tuple *orig,
 177                                         u8 icmp_proto)
 178 {
 179         key->ct_orig_proto = orig->dst.protonum;
 180         if (orig->dst.protonum == icmp_proto) {
 181                 key->ct.orig_tp.src = htons(orig->dst.u.icmp.type);
 182                 key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code);
 183         } else {
 184                 key->ct.orig_tp.src = orig->src.u.all;
 185                 key->ct.orig_tp.dst = orig->dst.u.all;
 186         }
 187 }
 188
 189 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
 190                                 const struct nf_conntrack_zone *zone,
 191                                 const struct nf_conn *ct)
 192 {
 193         key->ct_state = state;
 194         key->ct_zone = zone->id;
 195         key->ct.mark = ovs_ct_get_mark(ct);
 196         ovs_ct_get_labels(ct, &key->ct.labels);
 197
 198         if (ct) {
 199                 const struct nf_conntrack_tuple *orig;
 200
 201                 /* Use the master if we have one. */
 202                 if (ct->master)
 203                         ct = ct->master;
 204                 orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
 205
 206                 /* IP version must match with the master connection. */
 207                 if (key->eth.type == htons(ETH_P_IP) &&
 208                     nf_ct_l3num(ct) == NFPROTO_IPV4) {
 209                         key->ipv4.ct_orig.src = orig->src.u3.ip;
 210                         key->ipv4.ct_orig.dst = orig->dst.u3.ip;
 211                         __ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP);
 212                         return;
 213                 } else if (key->eth.type == htons(ETH_P_IPV6) &&
 214                            !sw_flow_key_is_nd(key) &&
 215                            nf_ct_l3num(ct) == NFPROTO_IPV6) {
 216                         key->ipv6.ct_orig.src = orig->src.u3.in6;
 217                         key->ipv6.ct_orig.dst = orig->dst.u3.in6;
 218                         __ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP);
 219                         return;
 220                 }
 221         }
 222         /* Clear 'ct_orig_proto' to mark the non-existence of conntrack
 223          * original direction key fields.
 224          */
 225         key->ct_orig_proto = 0;
 226 }
 227
 228 /* Update 'key' based on skb->_nfct.  If 'post_ct' is true, then OVS has
 229  * previously sent the packet to conntrack via the ct action.  If
 230  * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
 231  * initialized from the connection status.
 232  */
 233 static void ovs_ct_update_key(const struct sk_buff *skb,
 234                               const struct ovs_conntrack_info *info,
 235                               struct sw_flow_key *key, bool post_ct,
 236                               bool keep_nat_flags)
 237 {
 238         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 239         enum ip_conntrack_info ctinfo;
 240         struct nf_conn *ct;
 241         u8 state = 0;
 242
 243         ct = nf_ct_get(skb, &ctinfo);
 244         if (ct) {
 245                 state = ovs_ct_get_state(ctinfo);
 246                 /* All unconfirmed entries are NEW connections. */
 247                 if (!nf_ct_is_confirmed(ct))
 248                         state |= OVS_CS_F_NEW;
 249                 /* OVS persists the related flag for the duration of the
 250                  * connection.
 251                  */
 252                 if (ct->master)
 253                         state |= OVS_CS_F_RELATED;
 254                 if (keep_nat_flags) {
 255                         state |= key->ct_state & OVS_CS_F_NAT_MASK;
 256                 } else {
 257                         if (ct->status & IPS_SRC_NAT)
 258                                 state |= OVS_CS_F_SRC_NAT;
 259                         if (ct->status & IPS_DST_NAT)
 260                                 state |= OVS_CS_F_DST_NAT;
 261                 }
 262                 zone = nf_ct_zone(ct);
 263         } else if (post_ct) {
 264                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
 265                 if (info)
 266                         zone = &info->zone;
 267         }
 268         __ovs_ct_update_key(key, state, zone, ct);
 269 }
 270
 271 /* This is called to initialize CT key fields possibly coming in from the local
 272  * stack.
 273  */
 274 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
 275 {
 276         ovs_ct_update_key(skb, NULL, key, false, false);
 277 }
 278
 279 int ovs_ct_put_key(const struct sw_flow_key *swkey,
 280                    const struct sw_flow_key *output, struct sk_buff *skb)
 281 {
 282         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
 283                 return -EMSGSIZE;
 284
 285         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 286             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
 287                 return -EMSGSIZE;
 288
 289         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 290             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
 291                 return -EMSGSIZE;
 292
 293         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 294             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
 295                     &output->ct.labels))
 296                 return -EMSGSIZE;
 297
 298         if (swkey->ct_orig_proto) {
 299                 if (swkey->eth.type == htons(ETH_P_IP)) {
 300                         struct ovs_key_ct_tuple_ipv4 orig;
 301
 302                         memset(&orig, 0, sizeof(orig));
 303                         orig.ipv4_src = output->ipv4.ct_orig.src;
 304                         orig.ipv4_dst = output->ipv4.ct_orig.dst;
 305                         orig.src_port = output->ct.orig_tp.src;
 306                         orig.dst_port = output->ct.orig_tp.dst;
 307                         orig.ipv4_proto = output->ct_orig_proto;
 308
 309                         if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
 310                                     sizeof(orig), &orig))
 311                                 return -EMSGSIZE;
 312                 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
 313                         struct ovs_key_ct_tuple_ipv6 orig;
 314
 315                         memset(&orig, 0, sizeof(orig));
 316                         memcpy(orig.ipv6_src, output->ipv6.ct_orig.src.s6_addr32,
 317                                sizeof(orig.ipv6_src));
 318                         memcpy(orig.ipv6_dst, output->ipv6.ct_orig.dst.s6_addr32,
 319                                sizeof(orig.ipv6_dst));
 320                         orig.src_port = output->ct.orig_tp.src;
 321                         orig.dst_port = output->ct.orig_tp.dst;
 322                         orig.ipv6_proto = output->ct_orig_proto;
 323
 324                         if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
 325                                     sizeof(orig), &orig))
 326                                 return -EMSGSIZE;
 327                 }
 328         }
 329
 330         return 0;
 331 }
 332
 333 static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
 334                            u32 ct_mark, u32 mask)
 335 {
 336 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 337         u32 new_mark;
 338
 339         new_mark = ct_mark | (ct->mark & ~(mask));
 340         if (ct->mark != new_mark) {
 341                 ct->mark = new_mark;
 342                 if (nf_ct_is_confirmed(ct))
 343                         nf_conntrack_event_cache(IPCT_MARK, ct);
 344                 key->ct.mark = new_mark;
 345         }
 346
 347         return 0;
 348 #else
 349         return -ENOTSUPP;
 350 #endif
 351 }
 352
 353 static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
 354 {
 355         struct nf_conn_labels *cl;
 356
 357         cl = nf_ct_labels_find(ct);
 358         if (!cl) {
 359                 nf_ct_labels_ext_add(ct);
 360                 cl = nf_ct_labels_find(ct);
 361         }
 362
 363         return cl;
 364 }
 365
 366 /* Initialize labels for a new, yet to be committed conntrack entry.  Note that
 367  * since the new connection is not yet confirmed, and thus no-one else has
 368  * access to it's labels, we simply write them over.
 369  */
 370 static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
 371                               const struct ovs_key_ct_labels *labels,
 372                               const struct ovs_key_ct_labels *mask)
 373 {
 374         struct nf_conn_labels *cl, *master_cl;
 375         bool have_mask = labels_nonzero(mask);
 376
 377         /* Inherit master's labels to the related connection? */
 378         master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
 379
 380         if (!master_cl && !have_mask)
 381                 return 0;   /* Nothing to do. */
 382
 383         cl = ovs_ct_get_conn_labels(ct);
 384         if (!cl)
 385                 return -ENOSPC;
 386
 387         /* Inherit the master's labels, if any. */
 388         if (master_cl)
 389                 *cl = *master_cl;
 390
 391         if (have_mask) {
 392                 u32 *dst = (u32 *)cl->bits;
 393                 int i;
 394
 395                 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
 396                         dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
 397                                 (labels->ct_labels_32[i]
 398                                  & mask->ct_labels_32[i]);
 399         }
 400
 401         /* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
 402          * IPCT_LABEL bit is set in the event cache.
 403          */
 404         nf_conntrack_event_cache(IPCT_LABEL, ct);
 405
 406         memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
 407
 408         return 0;
 409 }
 410
 411 static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
 412                              const struct ovs_key_ct_labels *labels,
 413                              const struct ovs_key_ct_labels *mask)
 414 {
 415         struct nf_conn_labels *cl;
 416         int err;
 417
 418         cl = ovs_ct_get_conn_labels(ct);
 419         if (!cl)
 420                 return -ENOSPC;
 421
 422         err = nf_connlabels_replace(ct, labels->ct_labels_32,
 423                                     mask->ct_labels_32,
 424                                     OVS_CT_LABELS_LEN_32);
 425         if (err)
 426                 return err;
 427
 428         memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
 429
 430         return 0;
 431 }
 432
 433 /* 'skb' should already be pulled to nh_ofs. */
 434 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 435 {
 436         const struct nf_conntrack_helper *helper;
 437         const struct nf_conn_help *help;
 438         enum ip_conntrack_info ctinfo;
 439         unsigned int protoff;
 440         struct nf_conn *ct;
 441         int err;
 442
 443         ct = nf_ct_get(skb, &ctinfo);
 444         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 445                 return NF_ACCEPT;
 446
 447         help = nfct_help(ct);
 448         if (!help)
 449                 return NF_ACCEPT;
 450
 451         helper = rcu_dereference(help->helper);
 452         if (!helper)
 453                 return NF_ACCEPT;
 454
 455         switch (proto) {
 456         case NFPROTO_IPV4:
 457                 protoff = ip_hdrlen(skb);
 458                 break;
 459         case NFPROTO_IPV6: {
 460                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 461                 __be16 frag_off;
 462                 int ofs;
 463
 464                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 465                                        &frag_off);
 466                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 467                         pr_debug("proto header not found\n");
 468                         return NF_ACCEPT;
 469                 }
 470                 protoff = ofs;
 471                 break;
 472         }
 473         default:
 474                 WARN_ONCE(1, "helper invoked on non-IP family!");
 475                 return NF_DROP;
 476         }
 477
 478         err = helper->help(skb, protoff, ct, ctinfo);
 479         if (err != NF_ACCEPT)
 480                 return err;
 481
 482         /* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
 483          * FTP with NAT) adusting the TCP payload size when mangling IP
 484          * addresses and/or port numbers in the text-based control connection.
 485          */
 486         if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
 487             !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
 488                 return NF_DROP;
 489         return NF_ACCEPT;
 490 }
 491
 492 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 493  * value if 'skb' is freed.
 494  */
 495 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 496                             u16 zone, struct sk_buff *skb)
 497 {
 498         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 499         int err;
 500
 501         if (key->eth.type == htons(ETH_P_IP)) {
 502                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 503
 504                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 505                 err = ip_defrag(net, skb, user);
 506                 if (err)
 507                         return err;
 508
 509                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 510 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 511         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 512                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 513
 514                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 515                 err = nf_ct_frag6_gather(net, skb, user);
 516                 if (err) {
 517                         if (err != -EINPROGRESS)
 518                                 kfree_skb(skb);
 519                         return err;
 520                 }
 521
 522                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
 523                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 524 #endif
 525         } else {
 526                 kfree_skb(skb);
 527                 return -EPFNOSUPPORT;
 528         }
 529
 530         /* The key extracted from the fragment that completed this datagram
 531          * likely didn't have an L4 header, so regenerate it.
 532          */
 533         ovs_flow_key_update_l3l4(skb, key);
 534
 535         key->ip.frag = OVS_FRAG_TYPE_NONE;
 536         skb_clear_hash(skb);
 537         skb->ignore_df = 1;
 538         *OVS_CB(skb) = ovs_cb;
 539
 540         return 0;
 541 }
 542
 543 static struct nf_conntrack_expect *
 544 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 545                    u16 proto, const struct sk_buff *skb)
 546 {
 547         struct nf_conntrack_tuple tuple;
 548         struct nf_conntrack_expect *exp;
 549
 550         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
 551                 return NULL;
 552
 553         exp = __nf_ct_expect_find(net, zone, &tuple);
 554         if (exp) {
 555                 struct nf_conntrack_tuple_hash *h;
 556
 557                 /* Delete existing conntrack entry, if it clashes with the
 558                  * expectation.  This can happen since conntrack ALGs do not
 559                  * check for clashes between (new) expectations and existing
 560                  * conntrack entries.  nf_conntrack_in() will check the
 561                  * expectations only if a conntrack entry can not be found,
 562                  * which can lead to OVS finding the expectation (here) in the
 563                  * init direction, but which will not be removed by the
 564                  * nf_conntrack_in() call, if a matching conntrack entry is
 565                  * found instead.  In this case all init direction packets
 566                  * would be reported as new related packets, while reply
 567                  * direction packets would be reported as un-related
 568                  * established packets.
 569                  */
 570                 h = nf_conntrack_find_get(net, zone, &tuple);
 571                 if (h) {
 572                         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 573
 574                         nf_ct_delete(ct, 0, 0);
 575                         nf_conntrack_put(&ct->ct_general);
 576                 }
 577         }
 578
 579         return exp;
 580 }
 581
 582 /* This replicates logic from nf_conntrack_core.c that is not exported. */
 583 static enum ip_conntrack_info
 584 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
 585 {
 586         const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 587
 588         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
 589                 return IP_CT_ESTABLISHED_REPLY;
 590         /* Once we've had two way comms, always ESTABLISHED. */
 591         if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 592                 return IP_CT_ESTABLISHED;
 593         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
 594                 return IP_CT_RELATED;
 595         return IP_CT_NEW;
 596 }
 597
 598 /* Find an existing connection which this packet belongs to without
 599  * re-attributing statistics or modifying the connection state.  This allows an
 600  * skb->_nfct lost due to an upcall to be recovered during actions execution.
 601  *
 602  * Must be called with rcu_read_lock.
 603  *
 604  * On success, populates skb->_nfct and returns the connection.  Returns NULL
 605  * if there is no existing entry.
 606  */
 607 static struct nf_conn *
 608 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
 609                      u8 l3num, struct sk_buff *skb, bool natted)
 610 {
 611         struct nf_conntrack_tuple tuple;
 612         struct nf_conntrack_tuple_hash *h;
 613         struct nf_conn *ct;
 614
 615         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
 616                                net, &tuple)) {
 617                 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
 618                 return NULL;
 619         }
 620
 621         /* Must invert the tuple if skb has been transformed by NAT. */
 622         if (natted) {
 623                 struct nf_conntrack_tuple inverse;
 624
 625                 if (!nf_ct_invert_tuple(&inverse, &tuple)) {
 626                         pr_debug("ovs_ct_find_existing: Inversion failed!\n");
 627                         return NULL;
 628                 }
 629                 tuple = inverse;
 630         }
 631
 632         /* look for tuple match */
 633         h = nf_conntrack_find_get(net, zone, &tuple);
 634         if (!h)
 635                 return NULL;   /* Not found. */
 636
 637         ct = nf_ct_tuplehash_to_ctrack(h);
 638
 639         /* Inverted packet tuple matches the reverse direction conntrack tuple,
 640          * select the other tuplehash to get the right 'ctinfo' bits for this
 641          * packet.
 642          */
 643         if (natted)
 644                 h = &ct->tuplehash[!h->tuple.dst.dir];
 645
 646         nf_ct_set(skb, ct, ovs_ct_get_info(h));
 647         return ct;
 648 }
 649
 650 static
 651 struct nf_conn *ovs_ct_executed(struct net *net,
 652                                 const struct sw_flow_key *key,
 653                                 const struct ovs_conntrack_info *info,
 654                                 struct sk_buff *skb,
 655                                 bool *ct_executed)
 656 {
 657         struct nf_conn *ct = NULL;
 658
 659         /* If no ct, check if we have evidence that an existing conntrack entry
 660          * might be found for this skb.  This happens when we lose a skb->_nfct
 661          * due to an upcall, or if the direction is being forced.  If the
 662          * connection was not confirmed, it is not cached and needs to be run
 663          * through conntrack again.
 664          */
 665         *ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
 666                        !(key->ct_state & OVS_CS_F_INVALID) &&
 667                        (key->ct_zone == info->zone.id);
 668
 669         if (*ct_executed || (!key->ct_state && info->force)) {
 670                 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
 671                                           !!(key->ct_state &
 672                                           OVS_CS_F_NAT_MASK));
 673         }
 674
 675         return ct;
 676 }
 677
 678 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
 679 static bool skb_nfct_cached(struct net *net,
 680                             const struct sw_flow_key *key,
 681                             const struct ovs_conntrack_info *info,
 682                             struct sk_buff *skb)
 683 {
 684         enum ip_conntrack_info ctinfo;
 685         struct nf_conn *ct;
 686         bool ct_executed = true;
 687
 688         ct = nf_ct_get(skb, &ctinfo);
 689         if (!ct)
 690                 ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
 691
 692         if (ct)
 693                 nf_ct_get(skb, &ctinfo);
 694         else
 695                 return false;
 696
 697         if (!net_eq(net, read_pnet(&ct->ct_net)))
 698                 return false;
 699         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 700                 return false;
 701         if (info->helper) {
 702                 struct nf_conn_help *help;
 703
 704                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 705                 if (help && rcu_access_pointer(help->helper) != info->helper)
 706                         return false;
 707         }
 708         if (info->nf_ct_timeout) {
 709                 struct nf_conn_timeout *timeout_ext;
 710
 711                 timeout_ext = nf_ct_timeout_find(ct);
 712                 if (!timeout_ext || info->nf_ct_timeout !=
 713                     rcu_dereference(timeout_ext->timeout))
 714                         return false;
 715         }
 716         /* Force conntrack entry direction to the current packet? */
 717         if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
 718                 /* Delete the conntrack entry if confirmed, else just release
 719                  * the reference.
 720                  */
 721                 if (nf_ct_is_confirmed(ct))
 722                         nf_ct_delete(ct, 0, 0);
 723
 724                 nf_conntrack_put(&ct->ct_general);
 725                 nf_ct_set(skb, NULL, 0);
 726                 return false;
 727         }
 728
 729         return ct_executed;
 730 }
 731
 732 #if IS_ENABLED(CONFIG_NF_NAT)
 733 /* Modelled after nf_nat_ipv[46]_fn().
 734  * range is only used for new, uninitialized NAT state.
 735  * Returns either NF_ACCEPT or NF_DROP.
 736  */
 737 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 738                               enum ip_conntrack_info ctinfo,
 739                               const struct nf_nat_range2 *range,
 740                               enum nf_nat_manip_type maniptype)
 741 {
 742         int hooknum, nh_off, err = NF_ACCEPT;
 743
 744         nh_off = skb_network_offset(skb);
 745         skb_pull_rcsum(skb, nh_off);
 746
 747         /* See HOOK2MANIP(). */
 748         if (maniptype == NF_NAT_MANIP_SRC)
 749                 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
 750         else
 751                 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
 752
 753         switch (ctinfo) {
 754         case IP_CT_RELATED:
 755         case IP_CT_RELATED_REPLY:
 756                 if (IS_ENABLED(CONFIG_NF_NAT) &&
 757                     skb->protocol == htons(ETH_P_IP) &&
 758                     ip_hdr(skb)->protocol == IPPROTO_ICMP) {
 759                         if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
 760                                                            hooknum))
 761                                 err = NF_DROP;
 762                         goto push;
 763                 } else if (IS_ENABLED(CONFIG_IPV6) &&
 764                            skb->protocol == htons(ETH_P_IPV6)) {
 765                         __be16 frag_off;
 766                         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 767                         int hdrlen = ipv6_skip_exthdr(skb,
 768                                                       sizeof(struct ipv6hdr),
 769                                                       &nexthdr, &frag_off);
 770
 771                         if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
 772                                 if (!nf_nat_icmpv6_reply_translation(skb, ct,
 773                                                                      ctinfo,
 774                                                                      hooknum,
 775                                                                      hdrlen))
 776                                         err = NF_DROP;
 777                                 goto push;
 778                         }
 779                 }
 780                 /* Non-ICMP, fall thru to initialize if needed. */
 781                 fallthrough;
 782         case IP_CT_NEW:
 783                 /* Seen it before?  This can happen for loopback, retrans,
 784                  * or local packets.
 785                  */
 786                 if (!nf_nat_initialized(ct, maniptype)) {
 787                         /* Initialize according to the NAT action. */
 788                         err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
 789                                 /* Action is set up to establish a new
 790                                  * mapping.
 791                                  */
 792                                 ? nf_nat_setup_info(ct, range, maniptype)
 793                                 : nf_nat_alloc_null_binding(ct, hooknum);
 794                         if (err != NF_ACCEPT)
 795                                 goto push;
 796                 }
 797                 break;
 798
 799         case IP_CT_ESTABLISHED:
 800         case IP_CT_ESTABLISHED_REPLY:
 801                 break;
 802
 803         default:
 804                 err = NF_DROP;
 805                 goto push;
 806         }
 807
 808         err = nf_nat_packet(ct, ctinfo, hooknum, skb);
 809 push:
 810         skb_push(skb, nh_off);
 811         skb_postpush_rcsum(skb, skb->data, nh_off);
 812
 813         return err;
 814 }
 815
 816 static void ovs_nat_update_key(struct sw_flow_key *key,
 817                                const struct sk_buff *skb,
 818                                enum nf_nat_manip_type maniptype)
 819 {
 820         if (maniptype == NF_NAT_MANIP_SRC) {
 821                 __be16 src;
 822
 823                 key->ct_state |= OVS_CS_F_SRC_NAT;
 824                 if (key->eth.type == htons(ETH_P_IP))
 825                         key->ipv4.addr.src = ip_hdr(skb)->saddr;
 826                 else if (key->eth.type == htons(ETH_P_IPV6))
 827                         memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
 828                                sizeof(key->ipv6.addr.src));
 829                 else
 830                         return;
 831
 832                 if (key->ip.proto == IPPROTO_UDP)
 833                         src = udp_hdr(skb)->source;
 834                 else if (key->ip.proto == IPPROTO_TCP)
 835                         src = tcp_hdr(skb)->source;
 836                 else if (key->ip.proto == IPPROTO_SCTP)
 837                         src = sctp_hdr(skb)->source;
 838                 else
 839                         return;
 840
 841                 key->tp.src = src;
 842         } else {
 843                 __be16 dst;
 844
 845                 key->ct_state |= OVS_CS_F_DST_NAT;
 846                 if (key->eth.type == htons(ETH_P_IP))
 847                         key->ipv4.addr.dst = ip_hdr(skb)->daddr;
 848                 else if (key->eth.type == htons(ETH_P_IPV6))
 849                         memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
 850                                sizeof(key->ipv6.addr.dst));
 851                 else
 852                         return;
 853
 854                 if (key->ip.proto == IPPROTO_UDP)
 855                         dst = udp_hdr(skb)->dest;
 856                 else if (key->ip.proto == IPPROTO_TCP)
 857                         dst = tcp_hdr(skb)->dest;
 858                 else if (key->ip.proto == IPPROTO_SCTP)
 859                         dst = sctp_hdr(skb)->dest;
 860                 else
 861                         return;
 862
 863                 key->tp.dst = dst;
 864         }
 865 }
 866
 867 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
 868 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 869                       const struct ovs_conntrack_info *info,
 870                       struct sk_buff *skb, struct nf_conn *ct,
 871                       enum ip_conntrack_info ctinfo)
 872 {
 873         enum nf_nat_manip_type maniptype;
 874         int err;
 875
 876         /* Add NAT extension if not confirmed yet. */
 877         if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
 878                 return NF_ACCEPT;   /* Can't NAT. */
 879
 880         /* Determine NAT type.
 881          * Check if the NAT type can be deduced from the tracked connection.
 882          * Make sure new expected connections (IP_CT_RELATED) are NATted only
 883          * when committing.
 884          */
 885         if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
 886             ct->status & IPS_NAT_MASK &&
 887             (ctinfo != IP_CT_RELATED || info->commit)) {
 888                 /* NAT an established or related connection like before. */
 889                 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
 890                         /* This is the REPLY direction for a connection
 891                          * for which NAT was applied in the forward
 892                          * direction.  Do the reverse NAT.
 893                          */
 894                         maniptype = ct->status & IPS_SRC_NAT
 895                                 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
 896                 else
 897                         maniptype = ct->status & IPS_SRC_NAT
 898                                 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
 899         } else if (info->nat & OVS_CT_SRC_NAT) {
 900                 maniptype = NF_NAT_MANIP_SRC;
 901         } else if (info->nat & OVS_CT_DST_NAT) {
 902                 maniptype = NF_NAT_MANIP_DST;
 903         } else {
 904                 return NF_ACCEPT; /* Connection is not NATed. */
 905         }
 906         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
 907
 908         if (err == NF_ACCEPT && ct->status & IPS_DST_NAT) {
 909                 if (ct->status & IPS_SRC_NAT) {
 910                         if (maniptype == NF_NAT_MANIP_SRC)
 911                                 maniptype = NF_NAT_MANIP_DST;
 912                         else
 913                                 maniptype = NF_NAT_MANIP_SRC;
 914
 915                         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range,
 916                                                  maniptype);
 917                 } else if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) {
 918                         err = ovs_ct_nat_execute(skb, ct, ctinfo, NULL,
 919                                                  NF_NAT_MANIP_SRC);
 920                 }
 921         }
 922
 923         /* Mark NAT done if successful and update the flow key. */
 924         if (err == NF_ACCEPT)
 925                 ovs_nat_update_key(key, skb, maniptype);
 926
 927         return err;
 928 }
 929 #else /* !CONFIG_NF_NAT */
 930 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 931                       const struct ovs_conntrack_info *info,
 932                       struct sk_buff *skb, struct nf_conn *ct,
 933                       enum ip_conntrack_info ctinfo)
 934 {
 935         return NF_ACCEPT;
 936 }
 937 #endif
 938
 939 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
 940  * not done already.  Update key with new CT state after passing the packet
 941  * through conntrack.
 942  * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
 943  * set to NULL and 0 will be returned.
 944  */
 945 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 946                            const struct ovs_conntrack_info *info,
 947                            struct sk_buff *skb)
 948 {
 949         /* If we are recirculating packets to match on conntrack fields and
 950          * committing with a separate conntrack action,  then we don't need to
 951          * actually run the packet through conntrack twice unless it's for a
 952          * different zone.
 953          */
 954         bool cached = skb_nfct_cached(net, key, info, skb);
 955         enum ip_conntrack_info ctinfo;
 956         struct nf_conn *ct;
 957
 958         if (!cached) {
 959                 struct nf_hook_state state = {
 960                         .hook = NF_INET_PRE_ROUTING,
 961                         .pf = info->family,
 962                         .net = net,
 963                 };
 964                 struct nf_conn *tmpl = info->ct;
 965                 int err;
 966
 967                 /* Associate skb with specified zone. */
 968                 if (tmpl) {
 969                         if (skb_nfct(skb))
 970                                 nf_conntrack_put(skb_nfct(skb));
 971                         nf_conntrack_get(&tmpl->ct_general);
 972                         nf_ct_set(skb, tmpl, IP_CT_NEW);
 973                 }
 974
 975                 err = nf_conntrack_in(skb, &state);
 976                 if (err != NF_ACCEPT)
 977                         return -ENOENT;
 978
 979                 /* Clear CT state NAT flags to mark that we have not yet done
 980                  * NAT after the nf_conntrack_in() call.  We can actually clear
 981                  * the whole state, as it will be re-initialized below.
 982                  */
 983                 key->ct_state = 0;
 984
 985                 /* Update the key, but keep the NAT flags. */
 986                 ovs_ct_update_key(skb, info, key, true, true);
 987         }
 988
 989         ct = nf_ct_get(skb, &ctinfo);
 990         if (ct) {
 991                 bool add_helper = false;
 992
 993                 /* Packets starting a new connection must be NATted before the
 994                  * helper, so that the helper knows about the NAT.  We enforce
 995                  * this by delaying both NAT and helper calls for unconfirmed
 996                  * connections until the committing CT action.  For later
 997                  * packets NAT and Helper may be called in either order.
 998                  *
 999                  * NAT will be done only if the CT action has NAT, and only
1000                  * once per packet (per zone), as guarded by the NAT bits in
1001                  * the key->ct_state.
1002                  */
1003                 if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
1004                     (nf_ct_is_confirmed(ct) || info->commit) &&
1005                     ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
1006                         return -EINVAL;
1007                 }
1008
1009                 /* Userspace may decide to perform a ct lookup without a helper
1010                  * specified followed by a (recirculate and) commit with one,
1011                  * or attach a helper in a later commit.  Therefore, for
1012                  * connections which we will commit, we may need to attach
1013                  * the helper here.
1014                  */
1015                 if (info->commit && info->helper && !nfct_help(ct)) {
1016                         int err = __nf_ct_try_assign_helper(ct, info->ct,
1017                                                             GFP_ATOMIC);
1018                         if (err)
1019                                 return err;
1020                         add_helper = true;
1021
1022                         /* helper installed, add seqadj if NAT is required */
1023                         if (info->nat && !nfct_seqadj(ct)) {
1024                                 if (!nfct_seqadj_ext_add(ct))
1025                                         return -EINVAL;
1026                         }
1027                 }
1028
1029                 /* Call the helper only if:
1030                  * - nf_conntrack_in() was executed above ("!cached") or a
1031                  *   helper was just attached ("add_helper") for a confirmed
1032                  *   connection, or
1033                  * - When committing an unconfirmed connection.
1034                  */
1035                 if ((nf_ct_is_confirmed(ct) ? !cached || add_helper :
1036                                               info->commit) &&
1037                     ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
1038                         return -EINVAL;
1039                 }
1040         }
1041
1042         return 0;
1043 }
1044
1045 /* Lookup connection and read fields into key. */
1046 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
1047                          const struct ovs_conntrack_info *info,
1048                          struct sk_buff *skb)
1049 {
1050         struct nf_conntrack_expect *exp;
1051
1052         /* If we pass an expected packet through nf_conntrack_in() the
1053          * expectation is typically removed, but the packet could still be
1054          * lost in upcall processing.  To prevent this from happening we
1055          * perform an explicit expectation lookup.  Expected connections are
1056          * always new, and will be passed through conntrack only when they are
1057          * committed, as it is OK to remove the expectation at that time.
1058          */
1059         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
1060         if (exp) {
1061                 u8 state;
1062
1063                 /* NOTE: New connections are NATted and Helped only when
1064                  * committed, so we are not calling into NAT here.
1065                  */
1066                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
1067                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
1068         } else {
1069                 struct nf_conn *ct;
1070                 int err;
1071
1072                 err = __ovs_ct_lookup(net, key, info, skb);
1073                 if (err)
1074                         return err;
1075
1076                 ct = (struct nf_conn *)skb_nfct(skb);
1077                 if (ct)
1078                         nf_ct_deliver_cached_events(ct);
1079         }
1080
1081         return 0;
1082 }
1083
1084 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
1085 {
1086         size_t i;
1087
1088         for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
1089                 if (labels->ct_labels_32[i])
1090                         return true;
1091
1092         return false;
1093 }
1094
1095 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1096 static struct hlist_head *ct_limit_hash_bucket(
1097         const struct ovs_ct_limit_info *info, u16 zone)
1098 {
1099         return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
1100 }
1101
1102 /* Call with ovs_mutex */
1103 static void ct_limit_set(const struct ovs_ct_limit_info *info,
1104                          struct ovs_ct_limit *new_ct_limit)
1105 {
1106         struct ovs_ct_limit *ct_limit;
1107         struct hlist_head *head;
1108
1109         head = ct_limit_hash_bucket(info, new_ct_limit->zone);
1110         hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1111                 if (ct_limit->zone == new_ct_limit->zone) {
1112                         hlist_replace_rcu(&ct_limit->hlist_node,
1113                                           &new_ct_limit->hlist_node);
1114                         kfree_rcu(ct_limit, rcu);
1115                         return;
1116                 }
1117         }
1118
1119         hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
1120 }
1121
1122 /* Call with ovs_mutex */
1123 static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
1124 {
1125         struct ovs_ct_limit *ct_limit;
1126         struct hlist_head *head;
1127         struct hlist_node *n;
1128
1129         head = ct_limit_hash_bucket(info, zone);
1130         hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
1131                 if (ct_limit->zone == zone) {
1132                         hlist_del_rcu(&ct_limit->hlist_node);
1133                         kfree_rcu(ct_limit, rcu);
1134                         return;
1135                 }
1136         }
1137 }
1138
1139 /* Call with RCU read lock */
1140 static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
1141 {
1142         struct ovs_ct_limit *ct_limit;
1143         struct hlist_head *head;
1144
1145         head = ct_limit_hash_bucket(info, zone);
1146         hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1147                 if (ct_limit->zone == zone)
1148                         return ct_limit->limit;
1149         }
1150
1151         return info->default_limit;
1152 }
1153
1154 static int ovs_ct_check_limit(struct net *net,
1155                               const struct ovs_conntrack_info *info,
1156                               const struct nf_conntrack_tuple *tuple)
1157 {
1158         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1159         const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
1160         u32 per_zone_limit, connections;
1161         u32 conncount_key;
1162
1163         conncount_key = info->zone.id;
1164
1165         per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
1166         if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
1167                 return 0;
1168
1169         connections = nf_conncount_count(net, ct_limit_info->data,
1170                                          &conncount_key, tuple, &info->zone);
1171         if (connections > per_zone_limit)
1172                 return -ENOMEM;
1173
1174         return 0;
1175 }
1176 #endif
1177
1178 /* Lookup connection and confirm if unconfirmed. */
1179 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
1180                          const struct ovs_conntrack_info *info,
1181                          struct sk_buff *skb)
1182 {
1183         enum ip_conntrack_info ctinfo;
1184         struct nf_conn *ct;
1185         int err;
1186
1187         err = __ovs_ct_lookup(net, key, info, skb);
1188         if (err)
1189                 return err;
1190
1191         /* The connection could be invalid, in which case this is a no-op.*/
1192         ct = nf_ct_get(skb, &ctinfo);
1193         if (!ct)
1194                 return 0;
1195
1196 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1197         if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
1198                 if (!nf_ct_is_confirmed(ct)) {
1199                         err = ovs_ct_check_limit(net, info,
1200                                 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
1201                         if (err) {
1202                                 net_warn_ratelimited("openvswitch: zone: %u "
1203                                         "exceeds conntrack limit\n",
1204                                         info->zone.id);
1205                                 return err;
1206                         }
1207                 }
1208         }
1209 #endif
1210
1211         /* Set the conntrack event mask if given.  NEW and DELETE events have
1212          * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
1213          * typically would receive many kinds of updates.  Setting the event
1214          * mask allows those events to be filtered.  The set event mask will
1215          * remain in effect for the lifetime of the connection unless changed
1216          * by a further CT action with both the commit flag and the eventmask
1217          * option. */
1218         if (info->have_eventmask) {
1219                 struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
1220
1221                 if (cache)
1222                         cache->ctmask = info->eventmask;
1223         }
1224
1225         /* Apply changes before confirming the connection so that the initial
1226          * conntrack NEW netlink event carries the values given in the CT
1227          * action.
1228          */
1229         if (info->mark.mask) {
1230                 err = ovs_ct_set_mark(ct, key, info->mark.value,
1231                                       info->mark.mask);
1232                 if (err)
1233                         return err;
1234         }
1235         if (!nf_ct_is_confirmed(ct)) {
1236                 err = ovs_ct_init_labels(ct, key, &info->labels.value,
1237                                          &info->labels.mask);
1238                 if (err)
1239                         return err;
1240         } else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1241                    labels_nonzero(&info->labels.mask)) {
1242                 err = ovs_ct_set_labels(ct, key, &info->labels.value,
1243                                         &info->labels.mask);
1244                 if (err)
1245                         return err;
1246         }
1247         /* This will take care of sending queued events even if the connection
1248          * is already confirmed.
1249          */
1250         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
1251                 return -EINVAL;
1252
1253         return 0;
1254 }
1255
1256 /* Trim the skb to the length specified by the IP/IPv6 header,
1257  * removing any trailing lower-layer padding. This prepares the skb
1258  * for higher-layer processing that assumes skb->len excludes padding
1259  * (such as nf_ip_checksum). The caller needs to pull the skb to the
1260  * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
1261  */
1262 static int ovs_skb_network_trim(struct sk_buff *skb)
1263 {
1264         unsigned int len;
1265         int err;
1266
1267         switch (skb->protocol) {
1268         case htons(ETH_P_IP):
1269                 len = ntohs(ip_hdr(skb)->tot_len);
1270                 break;
1271         case htons(ETH_P_IPV6):
1272                 len = sizeof(struct ipv6hdr)
1273                         + ntohs(ipv6_hdr(skb)->payload_len);
1274                 break;
1275         default:
1276                 len = skb->len;
1277         }
1278
1279         err = pskb_trim_rcsum(skb, len);
1280         if (err)
1281                 kfree_skb(skb);
1282
1283         return err;
1284 }
1285
1286 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
1287  * value if 'skb' is freed.
1288  */
1289 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
1290                    struct sw_flow_key *key,
1291                    const struct ovs_conntrack_info *info)
1292 {
1293         int nh_ofs;
1294         int err;
1295
1296         /* The conntrack module expects to be working at L3. */
1297         nh_ofs = skb_network_offset(skb);
1298         skb_pull_rcsum(skb, nh_ofs);
1299
1300         err = ovs_skb_network_trim(skb);
1301         if (err)
1302                 return err;
1303
1304         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
1305                 err = handle_fragments(net, key, info->zone.id, skb);
1306                 if (err)
1307                         return err;
1308         }
1309
1310         if (info->commit)
1311                 err = ovs_ct_commit(net, key, info, skb);
1312         else
1313                 err = ovs_ct_lookup(net, key, info, skb);
1314
1315         skb_push(skb, nh_ofs);
1316         skb_postpush_rcsum(skb, skb->data, nh_ofs);
1317         if (err)
1318                 kfree_skb(skb);
1319         return err;
1320 }
1321
1322 int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
1323 {
1324         if (skb_nfct(skb)) {
1325                 nf_conntrack_put(skb_nfct(skb));
1326                 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
1327                 ovs_ct_fill_key(skb, key);
1328         }
1329
1330         return 0;
1331 }
1332
1333 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
1334                              const struct sw_flow_key *key, bool log)
1335 {
1336         struct nf_conntrack_helper *helper;
1337         struct nf_conn_help *help;
1338         int ret = 0;
1339
1340         helper = nf_conntrack_helper_try_module_get(name, info->family,
1341                                                     key->ip.proto);
1342         if (!helper) {
1343                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
1344                 return -EINVAL;
1345         }
1346
1347         help = nf_ct_helper_ext_add(info->ct, GFP_KERNEL);
1348         if (!help) {
1349                 nf_conntrack_helper_put(helper);
1350                 return -ENOMEM;
1351         }
1352
1353 #if IS_ENABLED(CONFIG_NF_NAT)
1354         if (info->nat) {
1355                 ret = nf_nat_helper_try_module_get(name, info->family,
1356                                                    key->ip.proto);
1357                 if (ret) {
1358                         nf_conntrack_helper_put(helper);
1359                         OVS_NLERR(log, "Failed to load \"%s\" NAT helper, error: %d",
1360                                   name, ret);
1361                         return ret;
1362                 }
1363         }
1364 #endif
1365         rcu_assign_pointer(help->helper, helper);
1366         info->helper = helper;
1367         return ret;
1368 }
1369
1370 #if IS_ENABLED(CONFIG_NF_NAT)
1371 static int parse_nat(const struct nlattr *attr,
1372                      struct ovs_conntrack_info *info, bool log)
1373 {
1374         struct nlattr *a;
1375         int rem;
1376         bool have_ip_max = false;
1377         bool have_proto_max = false;
1378         bool ip_vers = (info->family == NFPROTO_IPV6);
1379
1380         nla_for_each_nested(a, attr, rem) {
1381                 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
1382                         [OVS_NAT_ATTR_SRC] = {0, 0},
1383                         [OVS_NAT_ATTR_DST] = {0, 0},
1384                         [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
1385                                                  sizeof(struct in6_addr)},
1386                         [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
1387                                                  sizeof(struct in6_addr)},
1388                         [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
1389                         [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
1390                         [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
1391                         [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
1392                         [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
1393                 };
1394                 int type = nla_type(a);
1395
1396                 if (type > OVS_NAT_ATTR_MAX) {
1397                         OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
1398                                   type, OVS_NAT_ATTR_MAX);
1399                         return -EINVAL;
1400                 }
1401
1402                 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
1403                         OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
1404                                   type, nla_len(a),
1405                                   ovs_nat_attr_lens[type][ip_vers]);
1406                         return -EINVAL;
1407                 }
1408
1409                 switch (type) {
1410                 case OVS_NAT_ATTR_SRC:
1411                 case OVS_NAT_ATTR_DST:
1412                         if (info->nat) {
1413                                 OVS_NLERR(log, "Only one type of NAT may be specified");
1414                                 return -ERANGE;
1415                         }
1416                         info->nat |= OVS_CT_NAT;
1417                         info->nat |= ((type == OVS_NAT_ATTR_SRC)
1418                                         ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1419                         break;
1420
1421                 case OVS_NAT_ATTR_IP_MIN:
1422                         nla_memcpy(&info->range.min_addr, a,
1423                                    sizeof(info->range.min_addr));
1424                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1425                         break;
1426
1427                 case OVS_NAT_ATTR_IP_MAX:
1428                         have_ip_max = true;
1429                         nla_memcpy(&info->range.max_addr, a,
1430                                    sizeof(info->range.max_addr));
1431                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1432                         break;
1433
1434                 case OVS_NAT_ATTR_PROTO_MIN:
1435                         info->range.min_proto.all = htons(nla_get_u16(a));
1436                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1437                         break;
1438
1439                 case OVS_NAT_ATTR_PROTO_MAX:
1440                         have_proto_max = true;
1441                         info->range.max_proto.all = htons(nla_get_u16(a));
1442                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1443                         break;
1444
1445                 case OVS_NAT_ATTR_PERSISTENT:
1446                         info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1447                         break;
1448
1449                 case OVS_NAT_ATTR_PROTO_HASH:
1450                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1451                         break;
1452
1453                 case OVS_NAT_ATTR_PROTO_RANDOM:
1454                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1455                         break;
1456
1457                 default:
1458                         OVS_NLERR(log, "Unknown nat attribute (%d)", type);
1459                         return -EINVAL;
1460                 }
1461         }
1462
1463         if (rem > 0) {
1464                 OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
1465                 return -EINVAL;
1466         }
1467         if (!info->nat) {
1468                 /* Do not allow flags if no type is given. */
1469                 if (info->range.flags) {
1470                         OVS_NLERR(log,
1471                                   "NAT flags may be given only when NAT range (SRC or DST) is also specified."
1472                                   );
1473                         return -EINVAL;
1474                 }
1475                 info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1476         } else if (!info->commit) {
1477                 OVS_NLERR(log,
1478                           "NAT attributes may be specified only when CT COMMIT flag is also specified."
1479                           );
1480                 return -EINVAL;
1481         }
1482         /* Allow missing IP_MAX. */
1483         if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1484                 memcpy(&info->range.max_addr, &info->range.min_addr,
1485                        sizeof(info->range.max_addr));
1486         }
1487         /* Allow missing PROTO_MAX. */
1488         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1489             !have_proto_max) {
1490                 info->range.max_proto.all = info->range.min_proto.all;
1491         }
1492         return 0;
1493 }
1494 #endif
1495
1496 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1497         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
1498         [OVS_CT_ATTR_FORCE_COMMIT]      = { .minlen = 0, .maxlen = 0 },
1499         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
1500                                     .maxlen = sizeof(u16) },
1501         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
1502                                     .maxlen = sizeof(struct md_mark) },
1503         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
1504                                     .maxlen = sizeof(struct md_labels) },
1505         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
1506                                     .maxlen = NF_CT_HELPER_NAME_LEN },
1507 #if IS_ENABLED(CONFIG_NF_NAT)
1508         /* NAT length is checked when parsing the nested attributes. */
1509         [OVS_CT_ATTR_NAT]       = { .minlen = 0, .maxlen = INT_MAX },
1510 #endif
1511         [OVS_CT_ATTR_EVENTMASK] = { .minlen = sizeof(u32),
1512                                     .maxlen = sizeof(u32) },
1513         [OVS_CT_ATTR_TIMEOUT] = { .minlen = 1,
1514                                   .maxlen = CTNL_TIMEOUT_NAME_MAX },
1515 };
1516
1517 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1518                     const char **helper, bool log)
1519 {
1520         struct nlattr *a;
1521         int rem;
1522
1523         nla_for_each_nested(a, attr, rem) {
1524                 int type = nla_type(a);
1525                 int maxlen;
1526                 int minlen;
1527
1528                 if (type > OVS_CT_ATTR_MAX) {
1529                         OVS_NLERR(log,
1530                                   "Unknown conntrack attr (type=%d, max=%d)",
1531                                   type, OVS_CT_ATTR_MAX);
1532                         return -EINVAL;
1533                 }
1534
1535                 maxlen = ovs_ct_attr_lens[type].maxlen;
1536                 minlen = ovs_ct_attr_lens[type].minlen;
1537                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1538                         OVS_NLERR(log,
1539                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1540                                   type, nla_len(a), maxlen);
1541                         return -EINVAL;
1542                 }
1543
1544                 switch (type) {
1545                 case OVS_CT_ATTR_FORCE_COMMIT:
1546                         info->force = true;
1547                         fallthrough;
1548                 case OVS_CT_ATTR_COMMIT:
1549                         info->commit = true;
1550                         break;
1551 #ifdef CONFIG_NF_CONNTRACK_ZONES
1552                 case OVS_CT_ATTR_ZONE:
1553                         info->zone.id = nla_get_u16(a);
1554                         break;
1555 #endif
1556 #ifdef CONFIG_NF_CONNTRACK_MARK
1557                 case OVS_CT_ATTR_MARK: {
1558                         struct md_mark *mark = nla_data(a);
1559
1560                         if (!mark->mask) {
1561                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
1562                                 return -EINVAL;
1563                         }
1564                         info->mark = *mark;
1565                         break;
1566                 }
1567 #endif
1568 #ifdef CONFIG_NF_CONNTRACK_LABELS
1569                 case OVS_CT_ATTR_LABELS: {
1570                         struct md_labels *labels = nla_data(a);
1571
1572                         if (!labels_nonzero(&labels->mask)) {
1573                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
1574                                 return -EINVAL;
1575                         }
1576                         info->labels = *labels;
1577                         break;
1578                 }
1579 #endif
1580                 case OVS_CT_ATTR_HELPER:
1581                         *helper = nla_data(a);
1582                         if (!memchr(*helper, '\0', nla_len(a))) {
1583                                 OVS_NLERR(log, "Invalid conntrack helper");
1584                                 return -EINVAL;
1585                         }
1586                         break;
1587 #if IS_ENABLED(CONFIG_NF_NAT)
1588                 case OVS_CT_ATTR_NAT: {
1589                         int err = parse_nat(a, info, log);
1590
1591                         if (err)
1592                                 return err;
1593                         break;
1594                 }
1595 #endif
1596                 case OVS_CT_ATTR_EVENTMASK:
1597                         info->have_eventmask = true;
1598                         info->eventmask = nla_get_u32(a);
1599                         break;
1600 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
1601                 case OVS_CT_ATTR_TIMEOUT:
1602                         memcpy(info->timeout, nla_data(a), nla_len(a));
1603                         if (!memchr(info->timeout, '\0', nla_len(a))) {
1604                                 OVS_NLERR(log, "Invalid conntrack timeout");
1605                                 return -EINVAL;
1606                         }
1607                         break;
1608 #endif
1609
1610                 default:
1611                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
1612                                   type);
1613                         return -EINVAL;
1614                 }
1615         }
1616
1617 #ifdef CONFIG_NF_CONNTRACK_MARK
1618         if (!info->commit && info->mark.mask) {
1619                 OVS_NLERR(log,
1620                           "Setting conntrack mark requires 'commit' flag.");
1621                 return -EINVAL;
1622         }
1623 #endif
1624 #ifdef CONFIG_NF_CONNTRACK_LABELS
1625         if (!info->commit && labels_nonzero(&info->labels.mask)) {
1626                 OVS_NLERR(log,
1627                           "Setting conntrack labels requires 'commit' flag.");
1628                 return -EINVAL;
1629         }
1630 #endif
1631         if (rem > 0) {
1632                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1633                 return -EINVAL;
1634         }
1635
1636         return 0;
1637 }
1638
1639 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1640 {
1641         if (attr == OVS_KEY_ATTR_CT_STATE)
1642                 return true;
1643         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1644             attr == OVS_KEY_ATTR_CT_ZONE)
1645                 return true;
1646         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1647             attr == OVS_KEY_ATTR_CT_MARK)
1648                 return true;
1649         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1650             attr == OVS_KEY_ATTR_CT_LABELS) {
1651                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1652
1653                 return ovs_net->xt_label;
1654         }
1655
1656         return false;
1657 }
1658
1659 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1660                        const struct sw_flow_key *key,
1661                        struct sw_flow_actions **sfa,  bool log)
1662 {
1663         struct ovs_conntrack_info ct_info;
1664         const char *helper = NULL;
1665         u16 family;
1666         int err;
1667
1668         family = key_to_nfproto(key);
1669         if (family == NFPROTO_UNSPEC) {
1670                 OVS_NLERR(log, "ct family unspecified");
1671                 return -EINVAL;
1672         }
1673
1674         memset(&ct_info, 0, sizeof(ct_info));
1675         ct_info.family = family;
1676
1677         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1678                         NF_CT_DEFAULT_ZONE_DIR, 0);
1679
1680         err = parse_ct(attr, &ct_info, &helper, log);
1681         if (err)
1682                 return err;
1683
1684         /* Set up template for tracking connections in specific zones. */
1685         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1686         if (!ct_info.ct) {
1687                 OVS_NLERR(log, "Failed to allocate conntrack template");
1688                 return -ENOMEM;
1689         }
1690
1691         if (ct_info.timeout[0]) {
1692                 if (nf_ct_set_timeout(net, ct_info.ct, family, key->ip.proto,
1693                                       ct_info.timeout))
1694                         pr_info_ratelimited("Failed to associated timeout "
1695                                             "policy `%s'\n", ct_info.timeout);
1696                 else
1697                         ct_info.nf_ct_timeout = rcu_dereference(
1698                                 nf_ct_timeout_find(ct_info.ct)->timeout);
1699
1700         }
1701
1702         if (helper) {
1703                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1704                 if (err)
1705                         goto err_free_ct;
1706         }
1707
1708         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1709                                  sizeof(ct_info), log);
1710         if (err)
1711                 goto err_free_ct;
1712
1713         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1714         nf_conntrack_get(&ct_info.ct->ct_general);
1715         return 0;
1716 err_free_ct:
1717         __ovs_ct_free_action(&ct_info);
1718         return err;
1719 }
1720
1721 #if IS_ENABLED(CONFIG_NF_NAT)
1722 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1723                                struct sk_buff *skb)
1724 {
1725         struct nlattr *start;
1726
1727         start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
1728         if (!start)
1729                 return false;
1730
1731         if (info->nat & OVS_CT_SRC_NAT) {
1732                 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1733                         return false;
1734         } else if (info->nat & OVS_CT_DST_NAT) {
1735                 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1736                         return false;
1737         } else {
1738                 goto out;
1739         }
1740
1741         if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1742                 if (IS_ENABLED(CONFIG_NF_NAT) &&
1743                     info->family == NFPROTO_IPV4) {
1744                         if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1745                                             info->range.min_addr.ip) ||
1746                             (info->range.max_addr.ip
1747                              != info->range.min_addr.ip &&
1748                              (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1749                                               info->range.max_addr.ip))))
1750                                 return false;
1751                 } else if (IS_ENABLED(CONFIG_IPV6) &&
1752                            info->family == NFPROTO_IPV6) {
1753                         if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1754                                              &info->range.min_addr.in6) ||
1755                             (memcmp(&info->range.max_addr.in6,
1756                                     &info->range.min_addr.in6,
1757                                     sizeof(info->range.max_addr.in6)) &&
1758                              (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1759                                                &info->range.max_addr.in6))))
1760                                 return false;
1761                 } else {
1762                         return false;
1763                 }
1764         }
1765         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1766             (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1767                          ntohs(info->range.min_proto.all)) ||
1768              (info->range.max_proto.all != info->range.min_proto.all &&
1769               nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1770                           ntohs(info->range.max_proto.all)))))
1771                 return false;
1772
1773         if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1774             nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1775                 return false;
1776         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1777             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1778                 return false;
1779         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1780             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1781                 return false;
1782 out:
1783         nla_nest_end(skb, start);
1784
1785         return true;
1786 }
1787 #endif
1788
1789 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1790                           struct sk_buff *skb)
1791 {
1792         struct nlattr *start;
1793
1794         start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
1795         if (!start)
1796                 return -EMSGSIZE;
1797
1798         if (ct_info->commit && nla_put_flag(skb, ct_info->force
1799                                             ? OVS_CT_ATTR_FORCE_COMMIT
1800                                             : OVS_CT_ATTR_COMMIT))
1801                 return -EMSGSIZE;
1802         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1803             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1804                 return -EMSGSIZE;
1805         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1806             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1807                     &ct_info->mark))
1808                 return -EMSGSIZE;
1809         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1810             labels_nonzero(&ct_info->labels.mask) &&
1811             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1812                     &ct_info->labels))
1813                 return -EMSGSIZE;
1814         if (ct_info->helper) {
1815                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1816                                    ct_info->helper->name))
1817                         return -EMSGSIZE;
1818         }
1819         if (ct_info->have_eventmask &&
1820             nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
1821                 return -EMSGSIZE;
1822         if (ct_info->timeout[0]) {
1823                 if (nla_put_string(skb, OVS_CT_ATTR_TIMEOUT, ct_info->timeout))
1824                         return -EMSGSIZE;
1825         }
1826
1827 #if IS_ENABLED(CONFIG_NF_NAT)
1828         if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1829                 return -EMSGSIZE;
1830 #endif
1831         nla_nest_end(skb, start);
1832
1833         return 0;
1834 }
1835
1836 void ovs_ct_free_action(const struct nlattr *a)
1837 {
1838         struct ovs_conntrack_info *ct_info = nla_data(a);
1839
1840         __ovs_ct_free_action(ct_info);
1841 }
1842
1843 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1844 {
1845         if (ct_info->helper) {
1846 #if IS_ENABLED(CONFIG_NF_NAT)
1847                 if (ct_info->nat)
1848                         nf_nat_helper_put(ct_info->helper);
1849 #endif
1850                 nf_conntrack_helper_put(ct_info->helper);
1851         }
1852         if (ct_info->ct) {
1853                 if (ct_info->timeout[0])
1854                         nf_ct_destroy_timeout(ct_info->ct);
1855                 nf_ct_tmpl_free(ct_info->ct);
1856         }
1857 }
1858
1859 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1860 static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
1861 {
1862         int i, err;
1863
1864         ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
1865                                          GFP_KERNEL);
1866         if (!ovs_net->ct_limit_info)
1867                 return -ENOMEM;
1868
1869         ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
1870         ovs_net->ct_limit_info->limits =
1871                 kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
1872                               GFP_KERNEL);
1873         if (!ovs_net->ct_limit_info->limits) {
1874                 kfree(ovs_net->ct_limit_info);
1875                 return -ENOMEM;
1876         }
1877
1878         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
1879                 INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);
1880
1881         ovs_net->ct_limit_info->data =
1882                 nf_conncount_init(net, NFPROTO_INET, sizeof(u32));
1883
1884         if (IS_ERR(ovs_net->ct_limit_info->data)) {
1885                 err = PTR_ERR(ovs_net->ct_limit_info->data);
1886                 kfree(ovs_net->ct_limit_info->limits);
1887                 kfree(ovs_net->ct_limit_info);
1888                 pr_err("openvswitch: failed to init nf_conncount %d\n", err);
1889                 return err;
1890         }
1891         return 0;
1892 }
1893
1894 static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
1895 {
1896         const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
1897         int i;
1898
1899         nf_conncount_destroy(net, NFPROTO_INET, info->data);
1900         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
1901                 struct hlist_head *head = &info->limits[i];
1902                 struct ovs_ct_limit *ct_limit;
1903
1904                 hlist_for_each_entry_rcu(ct_limit, head, hlist_node,
1905                                          lockdep_ovsl_is_held())
1906                         kfree_rcu(ct_limit, rcu);
1907         }
1908         kfree(info->limits);
1909         kfree(info);
1910 }
1911
1912 static struct sk_buff *
1913 ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
1914                              struct ovs_header **ovs_reply_header)
1915 {
1916         struct ovs_header *ovs_header = info->userhdr;
1917         struct sk_buff *skb;
1918
1919         skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1920         if (!skb)
1921                 return ERR_PTR(-ENOMEM);
1922
1923         *ovs_reply_header = genlmsg_put(skb, info->snd_portid,
1924                                         info->snd_seq,
1925                                         &dp_ct_limit_genl_family, 0, cmd);
1926
1927         if (!*ovs_reply_header) {
1928                 nlmsg_free(skb);
1929                 return ERR_PTR(-EMSGSIZE);
1930         }
1931         (*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
1932
1933         return skb;
1934 }
1935
1936 static bool check_zone_id(int zone_id, u16 *pzone)
1937 {
1938         if (zone_id >= 0 && zone_id <= 65535) {
1939                 *pzone = (u16)zone_id;
1940                 return true;
1941         }
1942         return false;
1943 }
1944
1945 static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
1946                                        struct ovs_ct_limit_info *info)
1947 {
1948         struct ovs_zone_limit *zone_limit;
1949         int rem;
1950         u16 zone;
1951
1952         rem = NLA_ALIGN(nla_len(nla_zone_limit));
1953         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1954
1955         while (rem >= sizeof(*zone_limit)) {
1956                 if (unlikely(zone_limit->zone_id ==
1957                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1958                         ovs_lock();
1959                         info->default_limit = zone_limit->limit;
1960                         ovs_unlock();
1961                 } else if (unlikely(!check_zone_id(
1962                                 zone_limit->zone_id, &zone))) {
1963                         OVS_NLERR(true, "zone id is out of range");
1964                 } else {
1965                         struct ovs_ct_limit *ct_limit;
1966
1967                         ct_limit = kmalloc(sizeof(*ct_limit), GFP_KERNEL);
1968                         if (!ct_limit)
1969                                 return -ENOMEM;
1970
1971                         ct_limit->zone = zone;
1972                         ct_limit->limit = zone_limit->limit;
1973
1974                         ovs_lock();
1975                         ct_limit_set(info, ct_limit);
1976                         ovs_unlock();
1977                 }
1978                 rem -= NLA_ALIGN(sizeof(*zone_limit));
1979                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1980                                 NLA_ALIGN(sizeof(*zone_limit)));
1981         }
1982
1983         if (rem)
1984                 OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);
1985
1986         return 0;
1987 }
1988
1989 static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
1990                                        struct ovs_ct_limit_info *info)
1991 {
1992         struct ovs_zone_limit *zone_limit;
1993         int rem;
1994         u16 zone;
1995
1996         rem = NLA_ALIGN(nla_len(nla_zone_limit));
1997         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1998
1999         while (rem >= sizeof(*zone_limit)) {
2000                 if (unlikely(zone_limit->zone_id ==
2001                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
2002                         ovs_lock();
2003                         info->default_limit = OVS_CT_LIMIT_DEFAULT;
2004                         ovs_unlock();
2005                 } else if (unlikely(!check_zone_id(
2006                                 zone_limit->zone_id, &zone))) {
2007                         OVS_NLERR(true, "zone id is out of range");
2008                 } else {
2009                         ovs_lock();
2010                         ct_limit_del(info, zone);
2011                         ovs_unlock();
2012                 }
2013                 rem -= NLA_ALIGN(sizeof(*zone_limit));
2014                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2015                                 NLA_ALIGN(sizeof(*zone_limit)));
2016         }
2017
2018         if (rem)
2019                 OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);
2020
2021         return 0;
2022 }
2023
2024 static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
2025                                           struct sk_buff *reply)
2026 {
2027         struct ovs_zone_limit zone_limit;
2028         int err;
2029
2030         zone_limit.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE;
2031         zone_limit.limit = info->default_limit;
2032         err = nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
2033         if (err)
2034                 return err;
2035
2036         return 0;
2037 }
2038
2039 static int __ovs_ct_limit_get_zone_limit(struct net *net,
2040                                          struct nf_conncount_data *data,
2041                                          u16 zone_id, u32 limit,
2042                                          struct sk_buff *reply)
2043 {
2044         struct nf_conntrack_zone ct_zone;
2045         struct ovs_zone_limit zone_limit;
2046         u32 conncount_key = zone_id;
2047
2048         zone_limit.zone_id = zone_id;
2049         zone_limit.limit = limit;
2050         nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);
2051
2052         zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
2053                                               &ct_zone);
2054         return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
2055 }
2056
2057 static int ovs_ct_limit_get_zone_limit(struct net *net,
2058                                        struct nlattr *nla_zone_limit,
2059                                        struct ovs_ct_limit_info *info,
2060                                        struct sk_buff *reply)
2061 {
2062         struct ovs_zone_limit *zone_limit;
2063         int rem, err;
2064         u32 limit;
2065         u16 zone;
2066
2067         rem = NLA_ALIGN(nla_len(nla_zone_limit));
2068         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
2069
2070         while (rem >= sizeof(*zone_limit)) {
2071                 if (unlikely(zone_limit->zone_id ==
2072                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
2073                         err = ovs_ct_limit_get_default_limit(info, reply);
2074                         if (err)
2075                                 return err;
2076                 } else if (unlikely(!check_zone_id(zone_limit->zone_id,
2077                                                         &zone))) {
2078                         OVS_NLERR(true, "zone id is out of range");
2079                 } else {
2080                         rcu_read_lock();
2081                         limit = ct_limit_get(info, zone);
2082                         rcu_read_unlock();
2083
2084                         err = __ovs_ct_limit_get_zone_limit(
2085                                 net, info->data, zone, limit, reply);
2086                         if (err)
2087                                 return err;
2088                 }
2089                 rem -= NLA_ALIGN(sizeof(*zone_limit));
2090                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2091                                 NLA_ALIGN(sizeof(*zone_limit)));
2092         }
2093
2094         if (rem)
2095                 OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);
2096
2097         return 0;
2098 }
2099
2100 static int ovs_ct_limit_get_all_zone_limit(struct net *net,
2101                                            struct ovs_ct_limit_info *info,
2102                                            struct sk_buff *reply)
2103 {
2104         struct ovs_ct_limit *ct_limit;
2105         struct hlist_head *head;
2106         int i, err = 0;
2107
2108         err = ovs_ct_limit_get_default_limit(info, reply);
2109         if (err)
2110                 return err;
2111
2112         rcu_read_lock();
2113         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
2114                 head = &info->limits[i];
2115                 hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
2116                         err = __ovs_ct_limit_get_zone_limit(net, info->data,
2117                                 ct_limit->zone, ct_limit->limit, reply);
2118                         if (err)
2119                                 goto exit_err;
2120                 }
2121         }
2122
2123 exit_err:
2124         rcu_read_unlock();
2125         return err;
2126 }
2127
2128 static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
2129 {
2130         struct nlattr **a = info->attrs;
2131         struct sk_buff *reply;
2132         struct ovs_header *ovs_reply_header;
2133         struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2134         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2135         int err;
2136
2137         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
2138                                              &ovs_reply_header);
2139         if (IS_ERR(reply))
2140                 return PTR_ERR(reply);
2141
2142         if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2143                 err = -EINVAL;
2144                 goto exit_err;
2145         }
2146
2147         err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2148                                           ct_limit_info);
2149         if (err)
2150                 goto exit_err;
2151
2152         static_branch_enable(&ovs_ct_limit_enabled);
2153
2154         genlmsg_end(reply, ovs_reply_header);
2155         return genlmsg_reply(reply, info);
2156
2157 exit_err:
2158         nlmsg_free(reply);
2159         return err;
2160 }
2161
2162 static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
2163 {
2164         struct nlattr **a = info->attrs;
2165         struct sk_buff *reply;
2166         struct ovs_header *ovs_reply_header;
2167         struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2168         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2169         int err;
2170
2171         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
2172                                              &ovs_reply_header);
2173         if (IS_ERR(reply))
2174                 return PTR_ERR(reply);
2175
2176         if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2177                 err = -EINVAL;
2178                 goto exit_err;
2179         }
2180
2181         err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2182                                           ct_limit_info);
2183         if (err)
2184                 goto exit_err;
2185
2186         genlmsg_end(reply, ovs_reply_header);
2187         return genlmsg_reply(reply, info);
2188
2189 exit_err:
2190         nlmsg_free(reply);
2191         return err;
2192 }
2193
2194 static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
2195 {
2196         struct nlattr **a = info->attrs;
2197         struct nlattr *nla_reply;
2198         struct sk_buff *reply;
2199         struct ovs_header *ovs_reply_header;
2200         struct net *net = sock_net(skb->sk);
2201         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2202         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2203         int err;
2204
2205         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
2206                                              &ovs_reply_header);
2207         if (IS_ERR(reply))
2208                 return PTR_ERR(reply);
2209
2210         nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
2211         if (!nla_reply) {
2212                 err = -EMSGSIZE;
2213                 goto exit_err;
2214         }
2215
2216         if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2217                 err = ovs_ct_limit_get_zone_limit(
2218                         net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
2219                         reply);
2220                 if (err)
2221                         goto exit_err;
2222         } else {
2223                 err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
2224                                                       reply);
2225                 if (err)
2226                         goto exit_err;
2227         }
2228
2229         nla_nest_end(reply, nla_reply);
2230         genlmsg_end(reply, ovs_reply_header);
2231         return genlmsg_reply(reply, info);
2232
2233 exit_err:
2234         nlmsg_free(reply);
2235         return err;
2236 }
2237
2238 static const struct genl_small_ops ct_limit_genl_ops[] = {
2239         { .cmd = OVS_CT_LIMIT_CMD_SET,
2240                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2241                 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2242                                            * privilege. */
2243                 .doit = ovs_ct_limit_cmd_set,
2244         },
2245         { .cmd = OVS_CT_LIMIT_CMD_DEL,
2246                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2247                 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2248                                            * privilege. */
2249                 .doit = ovs_ct_limit_cmd_del,
2250         },
2251         { .cmd = OVS_CT_LIMIT_CMD_GET,
2252                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2253                 .flags = 0,               /* OK for unprivileged users. */
2254                 .doit = ovs_ct_limit_cmd_get,
2255         },
2256 };
2257
2258 static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
2259         .name = OVS_CT_LIMIT_MCGROUP,
2260 };
2261
2262 struct genl_family dp_ct_limit_genl_family __ro_after_init = {
2263         .hdrsize = sizeof(struct ovs_header),
2264         .name = OVS_CT_LIMIT_FAMILY,
2265         .version = OVS_CT_LIMIT_VERSION,
2266         .maxattr = OVS_CT_LIMIT_ATTR_MAX,
2267         .policy = ct_limit_policy,
2268         .netnsok = true,
2269         .parallel_ops = true,
2270         .small_ops = ct_limit_genl_ops,
2271         .n_small_ops = ARRAY_SIZE(ct_limit_genl_ops),
2272         .mcgrps = &ovs_ct_limit_multicast_group,
2273         .n_mcgrps = 1,
2274         .module = THIS_MODULE,
2275 };
2276 #endif
2277
2278 int ovs_ct_init(struct net *net)
2279 {
2280         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
2281         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2282
2283         if (nf_connlabels_get(net, n_bits - 1)) {
2284                 ovs_net->xt_label = false;
2285                 OVS_NLERR(true, "Failed to set connlabel length");
2286         } else {
2287                 ovs_net->xt_label = true;
2288         }
2289
2290 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2291         return ovs_ct_limit_init(net, ovs_net);
2292 #else
2293         return 0;
2294 #endif
2295 }
2296
2297 void ovs_ct_exit(struct net *net)
2298 {
2299         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2300
2301 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2302         ovs_ct_limit_exit(net, ovs_net);
2303 #endif
2304
2305         if (ovs_net->xt_label)
2306                 nf_connlabels_put(net);
2307 }