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,
 275                      struct sw_flow_key *key,
 276                      bool post_ct)
 277 {
 278         ovs_ct_update_key(skb, NULL, key, post_ct, false);
 279 }
 280
 281 int ovs_ct_put_key(const struct sw_flow_key *swkey,
 282                    const struct sw_flow_key *output, struct sk_buff *skb)
 283 {
 284         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
 285                 return -EMSGSIZE;
 286
 287         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
 288             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
 289                 return -EMSGSIZE;
 290
 291         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
 292             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
 293                 return -EMSGSIZE;
 294
 295         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
 296             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
 297                     &output->ct.labels))
 298                 return -EMSGSIZE;
 299
 300         if (swkey->ct_orig_proto) {
 301                 if (swkey->eth.type == htons(ETH_P_IP)) {
 302                         struct ovs_key_ct_tuple_ipv4 orig;
 303
 304                         memset(&orig, 0, sizeof(orig));
 305                         orig.ipv4_src = output->ipv4.ct_orig.src;
 306                         orig.ipv4_dst = output->ipv4.ct_orig.dst;
 307                         orig.src_port = output->ct.orig_tp.src;
 308                         orig.dst_port = output->ct.orig_tp.dst;
 309                         orig.ipv4_proto = output->ct_orig_proto;
 310
 311                         if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
 312                                     sizeof(orig), &orig))
 313                                 return -EMSGSIZE;
 314                 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
 315                         struct ovs_key_ct_tuple_ipv6 orig;
 316
 317                         memset(&orig, 0, sizeof(orig));
 318                         memcpy(orig.ipv6_src, output->ipv6.ct_orig.src.s6_addr32,
 319                                sizeof(orig.ipv6_src));
 320                         memcpy(orig.ipv6_dst, output->ipv6.ct_orig.dst.s6_addr32,
 321                                sizeof(orig.ipv6_dst));
 322                         orig.src_port = output->ct.orig_tp.src;
 323                         orig.dst_port = output->ct.orig_tp.dst;
 324                         orig.ipv6_proto = output->ct_orig_proto;
 325
 326                         if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
 327                                     sizeof(orig), &orig))
 328                                 return -EMSGSIZE;
 329                 }
 330         }
 331
 332         return 0;
 333 }
 334
 335 static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
 336                            u32 ct_mark, u32 mask)
 337 {
 338 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 339         u32 new_mark;
 340
 341         new_mark = ct_mark | (ct->mark & ~(mask));
 342         if (ct->mark != new_mark) {
 343                 ct->mark = new_mark;
 344                 if (nf_ct_is_confirmed(ct))
 345                         nf_conntrack_event_cache(IPCT_MARK, ct);
 346                 key->ct.mark = new_mark;
 347         }
 348
 349         return 0;
 350 #else
 351         return -ENOTSUPP;
 352 #endif
 353 }
 354
 355 static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
 356 {
 357         struct nf_conn_labels *cl;
 358
 359         cl = nf_ct_labels_find(ct);
 360         if (!cl) {
 361                 nf_ct_labels_ext_add(ct);
 362                 cl = nf_ct_labels_find(ct);
 363         }
 364
 365         return cl;
 366 }
 367
 368 /* Initialize labels for a new, yet to be committed conntrack entry.  Note that
 369  * since the new connection is not yet confirmed, and thus no-one else has
 370  * access to it's labels, we simply write them over.
 371  */
 372 static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
 373                               const struct ovs_key_ct_labels *labels,
 374                               const struct ovs_key_ct_labels *mask)
 375 {
 376         struct nf_conn_labels *cl, *master_cl;
 377         bool have_mask = labels_nonzero(mask);
 378
 379         /* Inherit master's labels to the related connection? */
 380         master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
 381
 382         if (!master_cl && !have_mask)
 383                 return 0;   /* Nothing to do. */
 384
 385         cl = ovs_ct_get_conn_labels(ct);
 386         if (!cl)
 387                 return -ENOSPC;
 388
 389         /* Inherit the master's labels, if any. */
 390         if (master_cl)
 391                 *cl = *master_cl;
 392
 393         if (have_mask) {
 394                 u32 *dst = (u32 *)cl->bits;
 395                 int i;
 396
 397                 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
 398                         dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
 399                                 (labels->ct_labels_32[i]
 400                                  & mask->ct_labels_32[i]);
 401         }
 402
 403         /* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
 404          * IPCT_LABEL bit is set in the event cache.
 405          */
 406         nf_conntrack_event_cache(IPCT_LABEL, ct);
 407
 408         memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
 409
 410         return 0;
 411 }
 412
 413 static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
 414                              const struct ovs_key_ct_labels *labels,
 415                              const struct ovs_key_ct_labels *mask)
 416 {
 417         struct nf_conn_labels *cl;
 418         int err;
 419
 420         cl = ovs_ct_get_conn_labels(ct);
 421         if (!cl)
 422                 return -ENOSPC;
 423
 424         err = nf_connlabels_replace(ct, labels->ct_labels_32,
 425                                     mask->ct_labels_32,
 426                                     OVS_CT_LABELS_LEN_32);
 427         if (err)
 428                 return err;
 429
 430         memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
 431
 432         return 0;
 433 }
 434
 435 /* 'skb' should already be pulled to nh_ofs. */
 436 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
 437 {
 438         const struct nf_conntrack_helper *helper;
 439         const struct nf_conn_help *help;
 440         enum ip_conntrack_info ctinfo;
 441         unsigned int protoff;
 442         struct nf_conn *ct;
 443         int err;
 444
 445         ct = nf_ct_get(skb, &ctinfo);
 446         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
 447                 return NF_ACCEPT;
 448
 449         help = nfct_help(ct);
 450         if (!help)
 451                 return NF_ACCEPT;
 452
 453         helper = rcu_dereference(help->helper);
 454         if (!helper)
 455                 return NF_ACCEPT;
 456
 457         switch (proto) {
 458         case NFPROTO_IPV4:
 459                 protoff = ip_hdrlen(skb);
 460                 break;
 461         case NFPROTO_IPV6: {
 462                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 463                 __be16 frag_off;
 464                 int ofs;
 465
 466                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
 467                                        &frag_off);
 468                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
 469                         pr_debug("proto header not found\n");
 470                         return NF_ACCEPT;
 471                 }
 472                 protoff = ofs;
 473                 break;
 474         }
 475         default:
 476                 WARN_ONCE(1, "helper invoked on non-IP family!");
 477                 return NF_DROP;
 478         }
 479
 480         err = helper->help(skb, protoff, ct, ctinfo);
 481         if (err != NF_ACCEPT)
 482                 return err;
 483
 484         /* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
 485          * FTP with NAT) adusting the TCP payload size when mangling IP
 486          * addresses and/or port numbers in the text-based control connection.
 487          */
 488         if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
 489             !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
 490                 return NF_DROP;
 491         return NF_ACCEPT;
 492 }
 493
 494 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 495  * value if 'skb' is freed.
 496  */
 497 static int handle_fragments(struct net *net, struct sw_flow_key *key,
 498                             u16 zone, struct sk_buff *skb)
 499 {
 500         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
 501         int err;
 502
 503         if (key->eth.type == htons(ETH_P_IP)) {
 504                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
 505
 506                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 507                 err = ip_defrag(net, skb, user);
 508                 if (err)
 509                         return err;
 510
 511                 ovs_cb.mru = IPCB(skb)->frag_max_size;
 512 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 513         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 514                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
 515
 516                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 517                 err = nf_ct_frag6_gather(net, skb, user);
 518                 if (err) {
 519                         if (err != -EINPROGRESS)
 520                                 kfree_skb(skb);
 521                         return err;
 522                 }
 523
 524                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
 525                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
 526 #endif
 527         } else {
 528                 kfree_skb(skb);
 529                 return -EPFNOSUPPORT;
 530         }
 531
 532         /* The key extracted from the fragment that completed this datagram
 533          * likely didn't have an L4 header, so regenerate it.
 534          */
 535         ovs_flow_key_update_l3l4(skb, key);
 536
 537         key->ip.frag = OVS_FRAG_TYPE_NONE;
 538         skb_clear_hash(skb);
 539         skb->ignore_df = 1;
 540         *OVS_CB(skb) = ovs_cb;
 541
 542         return 0;
 543 }
 544
 545 static struct nf_conntrack_expect *
 546 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
 547                    u16 proto, const struct sk_buff *skb)
 548 {
 549         struct nf_conntrack_tuple tuple;
 550         struct nf_conntrack_expect *exp;
 551
 552         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
 553                 return NULL;
 554
 555         exp = __nf_ct_expect_find(net, zone, &tuple);
 556         if (exp) {
 557                 struct nf_conntrack_tuple_hash *h;
 558
 559                 /* Delete existing conntrack entry, if it clashes with the
 560                  * expectation.  This can happen since conntrack ALGs do not
 561                  * check for clashes between (new) expectations and existing
 562                  * conntrack entries.  nf_conntrack_in() will check the
 563                  * expectations only if a conntrack entry can not be found,
 564                  * which can lead to OVS finding the expectation (here) in the
 565                  * init direction, but which will not be removed by the
 566                  * nf_conntrack_in() call, if a matching conntrack entry is
 567                  * found instead.  In this case all init direction packets
 568                  * would be reported as new related packets, while reply
 569                  * direction packets would be reported as un-related
 570                  * established packets.
 571                  */
 572                 h = nf_conntrack_find_get(net, zone, &tuple);
 573                 if (h) {
 574                         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 575
 576                         nf_ct_delete(ct, 0, 0);
 577                         nf_conntrack_put(&ct->ct_general);
 578                 }
 579         }
 580
 581         return exp;
 582 }
 583
 584 /* This replicates logic from nf_conntrack_core.c that is not exported. */
 585 static enum ip_conntrack_info
 586 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
 587 {
 588         const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 589
 590         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
 591                 return IP_CT_ESTABLISHED_REPLY;
 592         /* Once we've had two way comms, always ESTABLISHED. */
 593         if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
 594                 return IP_CT_ESTABLISHED;
 595         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
 596                 return IP_CT_RELATED;
 597         return IP_CT_NEW;
 598 }
 599
 600 /* Find an existing connection which this packet belongs to without
 601  * re-attributing statistics or modifying the connection state.  This allows an
 602  * skb->_nfct lost due to an upcall to be recovered during actions execution.
 603  *
 604  * Must be called with rcu_read_lock.
 605  *
 606  * On success, populates skb->_nfct and returns the connection.  Returns NULL
 607  * if there is no existing entry.
 608  */
 609 static struct nf_conn *
 610 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
 611                      u8 l3num, struct sk_buff *skb, bool natted)
 612 {
 613         struct nf_conntrack_tuple tuple;
 614         struct nf_conntrack_tuple_hash *h;
 615         struct nf_conn *ct;
 616
 617         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
 618                                net, &tuple)) {
 619                 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
 620                 return NULL;
 621         }
 622
 623         /* Must invert the tuple if skb has been transformed by NAT. */
 624         if (natted) {
 625                 struct nf_conntrack_tuple inverse;
 626
 627                 if (!nf_ct_invert_tuple(&inverse, &tuple)) {
 628                         pr_debug("ovs_ct_find_existing: Inversion failed!\n");
 629                         return NULL;
 630                 }
 631                 tuple = inverse;
 632         }
 633
 634         /* look for tuple match */
 635         h = nf_conntrack_find_get(net, zone, &tuple);
 636         if (!h)
 637                 return NULL;   /* Not found. */
 638
 639         ct = nf_ct_tuplehash_to_ctrack(h);
 640
 641         /* Inverted packet tuple matches the reverse direction conntrack tuple,
 642          * select the other tuplehash to get the right 'ctinfo' bits for this
 643          * packet.
 644          */
 645         if (natted)
 646                 h = &ct->tuplehash[!h->tuple.dst.dir];
 647
 648         nf_ct_set(skb, ct, ovs_ct_get_info(h));
 649         return ct;
 650 }
 651
 652 static
 653 struct nf_conn *ovs_ct_executed(struct net *net,
 654                                 const struct sw_flow_key *key,
 655                                 const struct ovs_conntrack_info *info,
 656                                 struct sk_buff *skb,
 657                                 bool *ct_executed)
 658 {
 659         struct nf_conn *ct = NULL;
 660
 661         /* If no ct, check if we have evidence that an existing conntrack entry
 662          * might be found for this skb.  This happens when we lose a skb->_nfct
 663          * due to an upcall, or if the direction is being forced.  If the
 664          * connection was not confirmed, it is not cached and needs to be run
 665          * through conntrack again.
 666          */
 667         *ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
 668                        !(key->ct_state & OVS_CS_F_INVALID) &&
 669                        (key->ct_zone == info->zone.id);
 670
 671         if (*ct_executed || (!key->ct_state && info->force)) {
 672                 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
 673                                           !!(key->ct_state &
 674                                           OVS_CS_F_NAT_MASK));
 675         }
 676
 677         return ct;
 678 }
 679
 680 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
 681 static bool skb_nfct_cached(struct net *net,
 682                             const struct sw_flow_key *key,
 683                             const struct ovs_conntrack_info *info,
 684                             struct sk_buff *skb)
 685 {
 686         enum ip_conntrack_info ctinfo;
 687         struct nf_conn *ct;
 688         bool ct_executed = true;
 689
 690         ct = nf_ct_get(skb, &ctinfo);
 691         if (!ct)
 692                 ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
 693
 694         if (ct)
 695                 nf_ct_get(skb, &ctinfo);
 696         else
 697                 return false;
 698
 699         if (!net_eq(net, read_pnet(&ct->ct_net)))
 700                 return false;
 701         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
 702                 return false;
 703         if (info->helper) {
 704                 struct nf_conn_help *help;
 705
 706                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
 707                 if (help && rcu_access_pointer(help->helper) != info->helper)
 708                         return false;
 709         }
 710         if (info->nf_ct_timeout) {
 711                 struct nf_conn_timeout *timeout_ext;
 712
 713                 timeout_ext = nf_ct_timeout_find(ct);
 714                 if (!timeout_ext || info->nf_ct_timeout !=
 715                     rcu_dereference(timeout_ext->timeout))
 716                         return false;
 717         }
 718         /* Force conntrack entry direction to the current packet? */
 719         if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
 720                 /* Delete the conntrack entry if confirmed, else just release
 721                  * the reference.
 722                  */
 723                 if (nf_ct_is_confirmed(ct))
 724                         nf_ct_delete(ct, 0, 0);
 725
 726                 nf_conntrack_put(&ct->ct_general);
 727                 nf_ct_set(skb, NULL, 0);
 728                 return false;
 729         }
 730
 731         return ct_executed;
 732 }
 733
 734 #if IS_ENABLED(CONFIG_NF_NAT)
 735 /* Modelled after nf_nat_ipv[46]_fn().
 736  * range is only used for new, uninitialized NAT state.
 737  * Returns either NF_ACCEPT or NF_DROP.
 738  */
 739 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
 740                               enum ip_conntrack_info ctinfo,
 741                               const struct nf_nat_range2 *range,
 742                               enum nf_nat_manip_type maniptype)
 743 {
 744         int hooknum, nh_off, err = NF_ACCEPT;
 745
 746         nh_off = skb_network_offset(skb);
 747         skb_pull_rcsum(skb, nh_off);
 748
 749         /* See HOOK2MANIP(). */
 750         if (maniptype == NF_NAT_MANIP_SRC)
 751                 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
 752         else
 753                 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
 754
 755         switch (ctinfo) {
 756         case IP_CT_RELATED:
 757         case IP_CT_RELATED_REPLY:
 758                 if (IS_ENABLED(CONFIG_NF_NAT) &&
 759                     skb->protocol == htons(ETH_P_IP) &&
 760                     ip_hdr(skb)->protocol == IPPROTO_ICMP) {
 761                         if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
 762                                                            hooknum))
 763                                 err = NF_DROP;
 764                         goto push;
 765                 } else if (IS_ENABLED(CONFIG_IPV6) &&
 766                            skb->protocol == htons(ETH_P_IPV6)) {
 767                         __be16 frag_off;
 768                         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 769                         int hdrlen = ipv6_skip_exthdr(skb,
 770                                                       sizeof(struct ipv6hdr),
 771                                                       &nexthdr, &frag_off);
 772
 773                         if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
 774                                 if (!nf_nat_icmpv6_reply_translation(skb, ct,
 775                                                                      ctinfo,
 776                                                                      hooknum,
 777                                                                      hdrlen))
 778                                         err = NF_DROP;
 779                                 goto push;
 780                         }
 781                 }
 782                 /* Non-ICMP, fall thru to initialize if needed. */
 783                 fallthrough;
 784         case IP_CT_NEW:
 785                 /* Seen it before?  This can happen for loopback, retrans,
 786                  * or local packets.
 787                  */
 788                 if (!nf_nat_initialized(ct, maniptype)) {
 789                         /* Initialize according to the NAT action. */
 790                         err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
 791                                 /* Action is set up to establish a new
 792                                  * mapping.
 793                                  */
 794                                 ? nf_nat_setup_info(ct, range, maniptype)
 795                                 : nf_nat_alloc_null_binding(ct, hooknum);
 796                         if (err != NF_ACCEPT)
 797                                 goto push;
 798                 }
 799                 break;
 800
 801         case IP_CT_ESTABLISHED:
 802         case IP_CT_ESTABLISHED_REPLY:
 803                 break;
 804
 805         default:
 806                 err = NF_DROP;
 807                 goto push;
 808         }
 809
 810         err = nf_nat_packet(ct, ctinfo, hooknum, skb);
 811 push:
 812         skb_push_rcsum(skb, nh_off);
 813
 814         return err;
 815 }
 816
 817 static void ovs_nat_update_key(struct sw_flow_key *key,
 818                                const struct sk_buff *skb,
 819                                enum nf_nat_manip_type maniptype)
 820 {
 821         if (maniptype == NF_NAT_MANIP_SRC) {
 822                 __be16 src;
 823
 824                 key->ct_state |= OVS_CS_F_SRC_NAT;
 825                 if (key->eth.type == htons(ETH_P_IP))
 826                         key->ipv4.addr.src = ip_hdr(skb)->saddr;
 827                 else if (key->eth.type == htons(ETH_P_IPV6))
 828                         memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
 829                                sizeof(key->ipv6.addr.src));
 830                 else
 831                         return;
 832
 833                 if (key->ip.proto == IPPROTO_UDP)
 834                         src = udp_hdr(skb)->source;
 835                 else if (key->ip.proto == IPPROTO_TCP)
 836                         src = tcp_hdr(skb)->source;
 837                 else if (key->ip.proto == IPPROTO_SCTP)
 838                         src = sctp_hdr(skb)->source;
 839                 else
 840                         return;
 841
 842                 key->tp.src = src;
 843         } else {
 844                 __be16 dst;
 845
 846                 key->ct_state |= OVS_CS_F_DST_NAT;
 847                 if (key->eth.type == htons(ETH_P_IP))
 848                         key->ipv4.addr.dst = ip_hdr(skb)->daddr;
 849                 else if (key->eth.type == htons(ETH_P_IPV6))
 850                         memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
 851                                sizeof(key->ipv6.addr.dst));
 852                 else
 853                         return;
 854
 855                 if (key->ip.proto == IPPROTO_UDP)
 856                         dst = udp_hdr(skb)->dest;
 857                 else if (key->ip.proto == IPPROTO_TCP)
 858                         dst = tcp_hdr(skb)->dest;
 859                 else if (key->ip.proto == IPPROTO_SCTP)
 860                         dst = sctp_hdr(skb)->dest;
 861                 else
 862                         return;
 863
 864                 key->tp.dst = dst;
 865         }
 866 }
 867
 868 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
 869 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 870                       const struct ovs_conntrack_info *info,
 871                       struct sk_buff *skb, struct nf_conn *ct,
 872                       enum ip_conntrack_info ctinfo)
 873 {
 874         enum nf_nat_manip_type maniptype;
 875         int err;
 876
 877         /* Add NAT extension if not confirmed yet. */
 878         if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
 879                 return NF_ACCEPT;   /* Can't NAT. */
 880
 881         /* Determine NAT type.
 882          * Check if the NAT type can be deduced from the tracked connection.
 883          * Make sure new expected connections (IP_CT_RELATED) are NATted only
 884          * when committing.
 885          */
 886         if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
 887             ct->status & IPS_NAT_MASK &&
 888             (ctinfo != IP_CT_RELATED || info->commit)) {
 889                 /* NAT an established or related connection like before. */
 890                 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
 891                         /* This is the REPLY direction for a connection
 892                          * for which NAT was applied in the forward
 893                          * direction.  Do the reverse NAT.
 894                          */
 895                         maniptype = ct->status & IPS_SRC_NAT
 896                                 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
 897                 else
 898                         maniptype = ct->status & IPS_SRC_NAT
 899                                 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
 900         } else if (info->nat & OVS_CT_SRC_NAT) {
 901                 maniptype = NF_NAT_MANIP_SRC;
 902         } else if (info->nat & OVS_CT_DST_NAT) {
 903                 maniptype = NF_NAT_MANIP_DST;
 904         } else {
 905                 return NF_ACCEPT; /* Connection is not NATed. */
 906         }
 907         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
 908
 909         if (err == NF_ACCEPT && ct->status & IPS_DST_NAT) {
 910                 if (ct->status & IPS_SRC_NAT) {
 911                         if (maniptype == NF_NAT_MANIP_SRC)
 912                                 maniptype = NF_NAT_MANIP_DST;
 913                         else
 914                                 maniptype = NF_NAT_MANIP_SRC;
 915
 916                         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range,
 917                                                  maniptype);
 918                 } else if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) {
 919                         err = ovs_ct_nat_execute(skb, ct, ctinfo, NULL,
 920                                                  NF_NAT_MANIP_SRC);
 921                 }
 922         }
 923
 924         /* Mark NAT done if successful and update the flow key. */
 925         if (err == NF_ACCEPT)
 926                 ovs_nat_update_key(key, skb, maniptype);
 927
 928         return err;
 929 }
 930 #else /* !CONFIG_NF_NAT */
 931 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 932                       const struct ovs_conntrack_info *info,
 933                       struct sk_buff *skb, struct nf_conn *ct,
 934                       enum ip_conntrack_info ctinfo)
 935 {
 936         return NF_ACCEPT;
 937 }
 938 #endif
 939
 940 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
 941  * not done already.  Update key with new CT state after passing the packet
 942  * through conntrack.
 943  * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
 944  * set to NULL and 0 will be returned.
 945  */
 946 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 947                            const struct ovs_conntrack_info *info,
 948                            struct sk_buff *skb)
 949 {
 950         /* If we are recirculating packets to match on conntrack fields and
 951          * committing with a separate conntrack action,  then we don't need to
 952          * actually run the packet through conntrack twice unless it's for a
 953          * different zone.
 954          */
 955         bool cached = skb_nfct_cached(net, key, info, skb);
 956         enum ip_conntrack_info ctinfo;
 957         struct nf_conn *ct;
 958
 959         if (!cached) {
 960                 struct nf_hook_state state = {
 961                         .hook = NF_INET_PRE_ROUTING,
 962                         .pf = info->family,
 963                         .net = net,
 964                 };
 965                 struct nf_conn *tmpl = info->ct;
 966                 int err;
 967
 968                 /* Associate skb with specified zone. */
 969                 if (tmpl) {
 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                 if (nf_ct_protonum(ct) == IPPROTO_TCP &&
1042                     nf_ct_is_confirmed(ct) && nf_conntrack_tcp_established(ct)) {
1043                         /* Be liberal for tcp packets so that out-of-window
1044                          * packets are not marked invalid.
1045                          */
1046                         nf_ct_set_tcp_be_liberal(ct);
1047                 }
1048         }
1049
1050         return 0;
1051 }
1052
1053 /* Lookup connection and read fields into key. */
1054 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
1055                          const struct ovs_conntrack_info *info,
1056                          struct sk_buff *skb)
1057 {
1058         struct nf_conntrack_expect *exp;
1059
1060         /* If we pass an expected packet through nf_conntrack_in() the
1061          * expectation is typically removed, but the packet could still be
1062          * lost in upcall processing.  To prevent this from happening we
1063          * perform an explicit expectation lookup.  Expected connections are
1064          * always new, and will be passed through conntrack only when they are
1065          * committed, as it is OK to remove the expectation at that time.
1066          */
1067         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
1068         if (exp) {
1069                 u8 state;
1070
1071                 /* NOTE: New connections are NATted and Helped only when
1072                  * committed, so we are not calling into NAT here.
1073                  */
1074                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
1075                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
1076         } else {
1077                 struct nf_conn *ct;
1078                 int err;
1079
1080                 err = __ovs_ct_lookup(net, key, info, skb);
1081                 if (err)
1082                         return err;
1083
1084                 ct = (struct nf_conn *)skb_nfct(skb);
1085                 if (ct)
1086                         nf_ct_deliver_cached_events(ct);
1087         }
1088
1089         return 0;
1090 }
1091
1092 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
1093 {
1094         size_t i;
1095
1096         for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
1097                 if (labels->ct_labels_32[i])
1098                         return true;
1099
1100         return false;
1101 }
1102
1103 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1104 static struct hlist_head *ct_limit_hash_bucket(
1105         const struct ovs_ct_limit_info *info, u16 zone)
1106 {
1107         return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
1108 }
1109
1110 /* Call with ovs_mutex */
1111 static void ct_limit_set(const struct ovs_ct_limit_info *info,
1112                          struct ovs_ct_limit *new_ct_limit)
1113 {
1114         struct ovs_ct_limit *ct_limit;
1115         struct hlist_head *head;
1116
1117         head = ct_limit_hash_bucket(info, new_ct_limit->zone);
1118         hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1119                 if (ct_limit->zone == new_ct_limit->zone) {
1120                         hlist_replace_rcu(&ct_limit->hlist_node,
1121                                           &new_ct_limit->hlist_node);
1122                         kfree_rcu(ct_limit, rcu);
1123                         return;
1124                 }
1125         }
1126
1127         hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
1128 }
1129
1130 /* Call with ovs_mutex */
1131 static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
1132 {
1133         struct ovs_ct_limit *ct_limit;
1134         struct hlist_head *head;
1135         struct hlist_node *n;
1136
1137         head = ct_limit_hash_bucket(info, zone);
1138         hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
1139                 if (ct_limit->zone == zone) {
1140                         hlist_del_rcu(&ct_limit->hlist_node);
1141                         kfree_rcu(ct_limit, rcu);
1142                         return;
1143                 }
1144         }
1145 }
1146
1147 /* Call with RCU read lock */
1148 static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
1149 {
1150         struct ovs_ct_limit *ct_limit;
1151         struct hlist_head *head;
1152
1153         head = ct_limit_hash_bucket(info, zone);
1154         hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1155                 if (ct_limit->zone == zone)
1156                         return ct_limit->limit;
1157         }
1158
1159         return info->default_limit;
1160 }
1161
1162 static int ovs_ct_check_limit(struct net *net,
1163                               const struct ovs_conntrack_info *info,
1164                               const struct nf_conntrack_tuple *tuple)
1165 {
1166         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1167         const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
1168         u32 per_zone_limit, connections;
1169         u32 conncount_key;
1170
1171         conncount_key = info->zone.id;
1172
1173         per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
1174         if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
1175                 return 0;
1176
1177         connections = nf_conncount_count(net, ct_limit_info->data,
1178                                          &conncount_key, tuple, &info->zone);
1179         if (connections > per_zone_limit)
1180                 return -ENOMEM;
1181
1182         return 0;
1183 }
1184 #endif
1185
1186 /* Lookup connection and confirm if unconfirmed. */
1187 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
1188                          const struct ovs_conntrack_info *info,
1189                          struct sk_buff *skb)
1190 {
1191         enum ip_conntrack_info ctinfo;
1192         struct nf_conn *ct;
1193         int err;
1194
1195         err = __ovs_ct_lookup(net, key, info, skb);
1196         if (err)
1197                 return err;
1198
1199         /* The connection could be invalid, in which case this is a no-op.*/
1200         ct = nf_ct_get(skb, &ctinfo);
1201         if (!ct)
1202                 return 0;
1203
1204 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1205         if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
1206                 if (!nf_ct_is_confirmed(ct)) {
1207                         err = ovs_ct_check_limit(net, info,
1208                                 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
1209                         if (err) {
1210                                 net_warn_ratelimited("openvswitch: zone: %u "
1211                                         "exceeds conntrack limit\n",
1212                                         info->zone.id);
1213                                 return err;
1214                         }
1215                 }
1216         }
1217 #endif
1218
1219         /* Set the conntrack event mask if given.  NEW and DELETE events have
1220          * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
1221          * typically would receive many kinds of updates.  Setting the event
1222          * mask allows those events to be filtered.  The set event mask will
1223          * remain in effect for the lifetime of the connection unless changed
1224          * by a further CT action with both the commit flag and the eventmask
1225          * option. */
1226         if (info->have_eventmask) {
1227                 struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
1228
1229                 if (cache)
1230                         cache->ctmask = info->eventmask;
1231         }
1232
1233         /* Apply changes before confirming the connection so that the initial
1234          * conntrack NEW netlink event carries the values given in the CT
1235          * action.
1236          */
1237         if (info->mark.mask) {
1238                 err = ovs_ct_set_mark(ct, key, info->mark.value,
1239                                       info->mark.mask);
1240                 if (err)
1241                         return err;
1242         }
1243         if (!nf_ct_is_confirmed(ct)) {
1244                 err = ovs_ct_init_labels(ct, key, &info->labels.value,
1245                                          &info->labels.mask);
1246                 if (err)
1247                         return err;
1248         } else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1249                    labels_nonzero(&info->labels.mask)) {
1250                 err = ovs_ct_set_labels(ct, key, &info->labels.value,
1251                                         &info->labels.mask);
1252                 if (err)
1253                         return err;
1254         }
1255         /* This will take care of sending queued events even if the connection
1256          * is already confirmed.
1257          */
1258         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
1259                 return -EINVAL;
1260
1261         return 0;
1262 }
1263
1264 /* Trim the skb to the length specified by the IP/IPv6 header,
1265  * removing any trailing lower-layer padding. This prepares the skb
1266  * for higher-layer processing that assumes skb->len excludes padding
1267  * (such as nf_ip_checksum). The caller needs to pull the skb to the
1268  * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
1269  */
1270 static int ovs_skb_network_trim(struct sk_buff *skb)
1271 {
1272         unsigned int len;
1273         int err;
1274
1275         switch (skb->protocol) {
1276         case htons(ETH_P_IP):
1277                 len = ntohs(ip_hdr(skb)->tot_len);
1278                 break;
1279         case htons(ETH_P_IPV6):
1280                 len = sizeof(struct ipv6hdr)
1281                         + ntohs(ipv6_hdr(skb)->payload_len);
1282                 break;
1283         default:
1284                 len = skb->len;
1285         }
1286
1287         err = pskb_trim_rcsum(skb, len);
1288         if (err)
1289                 kfree_skb(skb);
1290
1291         return err;
1292 }
1293
1294 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
1295  * value if 'skb' is freed.
1296  */
1297 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
1298                    struct sw_flow_key *key,
1299                    const struct ovs_conntrack_info *info)
1300 {
1301         int nh_ofs;
1302         int err;
1303
1304         /* The conntrack module expects to be working at L3. */
1305         nh_ofs = skb_network_offset(skb);
1306         skb_pull_rcsum(skb, nh_ofs);
1307
1308         err = ovs_skb_network_trim(skb);
1309         if (err)
1310                 return err;
1311
1312         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
1313                 err = handle_fragments(net, key, info->zone.id, skb);
1314                 if (err)
1315                         return err;
1316         }
1317
1318         if (info->commit)
1319                 err = ovs_ct_commit(net, key, info, skb);
1320         else
1321                 err = ovs_ct_lookup(net, key, info, skb);
1322
1323         skb_push_rcsum(skb, nh_ofs);
1324         if (err)
1325                 kfree_skb(skb);
1326         return err;
1327 }
1328
1329 int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
1330 {
1331         nf_conntrack_put(skb_nfct(skb));
1332         nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
1333         ovs_ct_fill_key(skb, key, false);
1334
1335         return 0;
1336 }
1337
1338 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
1339                              const struct sw_flow_key *key, bool log)
1340 {
1341         struct nf_conntrack_helper *helper;
1342         struct nf_conn_help *help;
1343         int ret = 0;
1344
1345         helper = nf_conntrack_helper_try_module_get(name, info->family,
1346                                                     key->ip.proto);
1347         if (!helper) {
1348                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
1349                 return -EINVAL;
1350         }
1351
1352         help = nf_ct_helper_ext_add(info->ct, GFP_KERNEL);
1353         if (!help) {
1354                 nf_conntrack_helper_put(helper);
1355                 return -ENOMEM;
1356         }
1357
1358 #if IS_ENABLED(CONFIG_NF_NAT)
1359         if (info->nat) {
1360                 ret = nf_nat_helper_try_module_get(name, info->family,
1361                                                    key->ip.proto);
1362                 if (ret) {
1363                         nf_conntrack_helper_put(helper);
1364                         OVS_NLERR(log, "Failed to load \"%s\" NAT helper, error: %d",
1365                                   name, ret);
1366                         return ret;
1367                 }
1368         }
1369 #endif
1370         rcu_assign_pointer(help->helper, helper);
1371         info->helper = helper;
1372         return ret;
1373 }
1374
1375 #if IS_ENABLED(CONFIG_NF_NAT)
1376 static int parse_nat(const struct nlattr *attr,
1377                      struct ovs_conntrack_info *info, bool log)
1378 {
1379         struct nlattr *a;
1380         int rem;
1381         bool have_ip_max = false;
1382         bool have_proto_max = false;
1383         bool ip_vers = (info->family == NFPROTO_IPV6);
1384
1385         nla_for_each_nested(a, attr, rem) {
1386                 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
1387                         [OVS_NAT_ATTR_SRC] = {0, 0},
1388                         [OVS_NAT_ATTR_DST] = {0, 0},
1389                         [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
1390                                                  sizeof(struct in6_addr)},
1391                         [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
1392                                                  sizeof(struct in6_addr)},
1393                         [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
1394                         [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
1395                         [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
1396                         [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
1397                         [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
1398                 };
1399                 int type = nla_type(a);
1400
1401                 if (type > OVS_NAT_ATTR_MAX) {
1402                         OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
1403                                   type, OVS_NAT_ATTR_MAX);
1404                         return -EINVAL;
1405                 }
1406
1407                 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
1408                         OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
1409                                   type, nla_len(a),
1410                                   ovs_nat_attr_lens[type][ip_vers]);
1411                         return -EINVAL;
1412                 }
1413
1414                 switch (type) {
1415                 case OVS_NAT_ATTR_SRC:
1416                 case OVS_NAT_ATTR_DST:
1417                         if (info->nat) {
1418                                 OVS_NLERR(log, "Only one type of NAT may be specified");
1419                                 return -ERANGE;
1420                         }
1421                         info->nat |= OVS_CT_NAT;
1422                         info->nat |= ((type == OVS_NAT_ATTR_SRC)
1423                                         ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1424                         break;
1425
1426                 case OVS_NAT_ATTR_IP_MIN:
1427                         nla_memcpy(&info->range.min_addr, a,
1428                                    sizeof(info->range.min_addr));
1429                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1430                         break;
1431
1432                 case OVS_NAT_ATTR_IP_MAX:
1433                         have_ip_max = true;
1434                         nla_memcpy(&info->range.max_addr, a,
1435                                    sizeof(info->range.max_addr));
1436                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1437                         break;
1438
1439                 case OVS_NAT_ATTR_PROTO_MIN:
1440                         info->range.min_proto.all = htons(nla_get_u16(a));
1441                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1442                         break;
1443
1444                 case OVS_NAT_ATTR_PROTO_MAX:
1445                         have_proto_max = true;
1446                         info->range.max_proto.all = htons(nla_get_u16(a));
1447                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1448                         break;
1449
1450                 case OVS_NAT_ATTR_PERSISTENT:
1451                         info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1452                         break;
1453
1454                 case OVS_NAT_ATTR_PROTO_HASH:
1455                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1456                         break;
1457
1458                 case OVS_NAT_ATTR_PROTO_RANDOM:
1459                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1460                         break;
1461
1462                 default:
1463                         OVS_NLERR(log, "Unknown nat attribute (%d)", type);
1464                         return -EINVAL;
1465                 }
1466         }
1467
1468         if (rem > 0) {
1469                 OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
1470                 return -EINVAL;
1471         }
1472         if (!info->nat) {
1473                 /* Do not allow flags if no type is given. */
1474                 if (info->range.flags) {
1475                         OVS_NLERR(log,
1476                                   "NAT flags may be given only when NAT range (SRC or DST) is also specified."
1477                                   );
1478                         return -EINVAL;
1479                 }
1480                 info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1481         } else if (!info->commit) {
1482                 OVS_NLERR(log,
1483                           "NAT attributes may be specified only when CT COMMIT flag is also specified."
1484                           );
1485                 return -EINVAL;
1486         }
1487         /* Allow missing IP_MAX. */
1488         if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1489                 memcpy(&info->range.max_addr, &info->range.min_addr,
1490                        sizeof(info->range.max_addr));
1491         }
1492         /* Allow missing PROTO_MAX. */
1493         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1494             !have_proto_max) {
1495                 info->range.max_proto.all = info->range.min_proto.all;
1496         }
1497         return 0;
1498 }
1499 #endif
1500
1501 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1502         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
1503         [OVS_CT_ATTR_FORCE_COMMIT]      = { .minlen = 0, .maxlen = 0 },
1504         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
1505                                     .maxlen = sizeof(u16) },
1506         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
1507                                     .maxlen = sizeof(struct md_mark) },
1508         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
1509                                     .maxlen = sizeof(struct md_labels) },
1510         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
1511                                     .maxlen = NF_CT_HELPER_NAME_LEN },
1512 #if IS_ENABLED(CONFIG_NF_NAT)
1513         /* NAT length is checked when parsing the nested attributes. */
1514         [OVS_CT_ATTR_NAT]       = { .minlen = 0, .maxlen = INT_MAX },
1515 #endif
1516         [OVS_CT_ATTR_EVENTMASK] = { .minlen = sizeof(u32),
1517                                     .maxlen = sizeof(u32) },
1518         [OVS_CT_ATTR_TIMEOUT] = { .minlen = 1,
1519                                   .maxlen = CTNL_TIMEOUT_NAME_MAX },
1520 };
1521
1522 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1523                     const char **helper, bool log)
1524 {
1525         struct nlattr *a;
1526         int rem;
1527
1528         nla_for_each_nested(a, attr, rem) {
1529                 int type = nla_type(a);
1530                 int maxlen;
1531                 int minlen;
1532
1533                 if (type > OVS_CT_ATTR_MAX) {
1534                         OVS_NLERR(log,
1535                                   "Unknown conntrack attr (type=%d, max=%d)",
1536                                   type, OVS_CT_ATTR_MAX);
1537                         return -EINVAL;
1538                 }
1539
1540                 maxlen = ovs_ct_attr_lens[type].maxlen;
1541                 minlen = ovs_ct_attr_lens[type].minlen;
1542                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1543                         OVS_NLERR(log,
1544                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1545                                   type, nla_len(a), maxlen);
1546                         return -EINVAL;
1547                 }
1548
1549                 switch (type) {
1550                 case OVS_CT_ATTR_FORCE_COMMIT:
1551                         info->force = true;
1552                         fallthrough;
1553                 case OVS_CT_ATTR_COMMIT:
1554                         info->commit = true;
1555                         break;
1556 #ifdef CONFIG_NF_CONNTRACK_ZONES
1557                 case OVS_CT_ATTR_ZONE:
1558                         info->zone.id = nla_get_u16(a);
1559                         break;
1560 #endif
1561 #ifdef CONFIG_NF_CONNTRACK_MARK
1562                 case OVS_CT_ATTR_MARK: {
1563                         struct md_mark *mark = nla_data(a);
1564
1565                         if (!mark->mask) {
1566                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
1567                                 return -EINVAL;
1568                         }
1569                         info->mark = *mark;
1570                         break;
1571                 }
1572 #endif
1573 #ifdef CONFIG_NF_CONNTRACK_LABELS
1574                 case OVS_CT_ATTR_LABELS: {
1575                         struct md_labels *labels = nla_data(a);
1576
1577                         if (!labels_nonzero(&labels->mask)) {
1578                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
1579                                 return -EINVAL;
1580                         }
1581                         info->labels = *labels;
1582                         break;
1583                 }
1584 #endif
1585                 case OVS_CT_ATTR_HELPER:
1586                         *helper = nla_data(a);
1587                         if (!memchr(*helper, '\0', nla_len(a))) {
1588                                 OVS_NLERR(log, "Invalid conntrack helper");
1589                                 return -EINVAL;
1590                         }
1591                         break;
1592 #if IS_ENABLED(CONFIG_NF_NAT)
1593                 case OVS_CT_ATTR_NAT: {
1594                         int err = parse_nat(a, info, log);
1595
1596                         if (err)
1597                                 return err;
1598                         break;
1599                 }
1600 #endif
1601                 case OVS_CT_ATTR_EVENTMASK:
1602                         info->have_eventmask = true;
1603                         info->eventmask = nla_get_u32(a);
1604                         break;
1605 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
1606                 case OVS_CT_ATTR_TIMEOUT:
1607                         memcpy(info->timeout, nla_data(a), nla_len(a));
1608                         if (!memchr(info->timeout, '\0', nla_len(a))) {
1609                                 OVS_NLERR(log, "Invalid conntrack timeout");
1610                                 return -EINVAL;
1611                         }
1612                         break;
1613 #endif
1614
1615                 default:
1616                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
1617                                   type);
1618                         return -EINVAL;
1619                 }
1620         }
1621
1622 #ifdef CONFIG_NF_CONNTRACK_MARK
1623         if (!info->commit && info->mark.mask) {
1624                 OVS_NLERR(log,
1625                           "Setting conntrack mark requires 'commit' flag.");
1626                 return -EINVAL;
1627         }
1628 #endif
1629 #ifdef CONFIG_NF_CONNTRACK_LABELS
1630         if (!info->commit && labels_nonzero(&info->labels.mask)) {
1631                 OVS_NLERR(log,
1632                           "Setting conntrack labels requires 'commit' flag.");
1633                 return -EINVAL;
1634         }
1635 #endif
1636         if (rem > 0) {
1637                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1638                 return -EINVAL;
1639         }
1640
1641         return 0;
1642 }
1643
1644 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1645 {
1646         if (attr == OVS_KEY_ATTR_CT_STATE)
1647                 return true;
1648         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1649             attr == OVS_KEY_ATTR_CT_ZONE)
1650                 return true;
1651         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1652             attr == OVS_KEY_ATTR_CT_MARK)
1653                 return true;
1654         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1655             attr == OVS_KEY_ATTR_CT_LABELS) {
1656                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1657
1658                 return ovs_net->xt_label;
1659         }
1660
1661         return false;
1662 }
1663
1664 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1665                        const struct sw_flow_key *key,
1666                        struct sw_flow_actions **sfa,  bool log)
1667 {
1668         struct ovs_conntrack_info ct_info;
1669         const char *helper = NULL;
1670         u16 family;
1671         int err;
1672
1673         family = key_to_nfproto(key);
1674         if (family == NFPROTO_UNSPEC) {
1675                 OVS_NLERR(log, "ct family unspecified");
1676                 return -EINVAL;
1677         }
1678
1679         memset(&ct_info, 0, sizeof(ct_info));
1680         ct_info.family = family;
1681
1682         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1683                         NF_CT_DEFAULT_ZONE_DIR, 0);
1684
1685         err = parse_ct(attr, &ct_info, &helper, log);
1686         if (err)
1687                 return err;
1688
1689         /* Set up template for tracking connections in specific zones. */
1690         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1691         if (!ct_info.ct) {
1692                 OVS_NLERR(log, "Failed to allocate conntrack template");
1693                 return -ENOMEM;
1694         }
1695
1696         if (ct_info.timeout[0]) {
1697                 if (nf_ct_set_timeout(net, ct_info.ct, family, key->ip.proto,
1698                                       ct_info.timeout))
1699                         pr_info_ratelimited("Failed to associated timeout "
1700                                             "policy `%s'\n", ct_info.timeout);
1701                 else
1702                         ct_info.nf_ct_timeout = rcu_dereference(
1703                                 nf_ct_timeout_find(ct_info.ct)->timeout);
1704
1705         }
1706
1707         if (helper) {
1708                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1709                 if (err)
1710                         goto err_free_ct;
1711         }
1712
1713         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1714                                  sizeof(ct_info), log);
1715         if (err)
1716                 goto err_free_ct;
1717
1718         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1719         nf_conntrack_get(&ct_info.ct->ct_general);
1720         return 0;
1721 err_free_ct:
1722         __ovs_ct_free_action(&ct_info);
1723         return err;
1724 }
1725
1726 #if IS_ENABLED(CONFIG_NF_NAT)
1727 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1728                                struct sk_buff *skb)
1729 {
1730         struct nlattr *start;
1731
1732         start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
1733         if (!start)
1734                 return false;
1735
1736         if (info->nat & OVS_CT_SRC_NAT) {
1737                 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1738                         return false;
1739         } else if (info->nat & OVS_CT_DST_NAT) {
1740                 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1741                         return false;
1742         } else {
1743                 goto out;
1744         }
1745
1746         if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1747                 if (IS_ENABLED(CONFIG_NF_NAT) &&
1748                     info->family == NFPROTO_IPV4) {
1749                         if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1750                                             info->range.min_addr.ip) ||
1751                             (info->range.max_addr.ip
1752                              != info->range.min_addr.ip &&
1753                              (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1754                                               info->range.max_addr.ip))))
1755                                 return false;
1756                 } else if (IS_ENABLED(CONFIG_IPV6) &&
1757                            info->family == NFPROTO_IPV6) {
1758                         if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1759                                              &info->range.min_addr.in6) ||
1760                             (memcmp(&info->range.max_addr.in6,
1761                                     &info->range.min_addr.in6,
1762                                     sizeof(info->range.max_addr.in6)) &&
1763                              (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1764                                                &info->range.max_addr.in6))))
1765                                 return false;
1766                 } else {
1767                         return false;
1768                 }
1769         }
1770         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1771             (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1772                          ntohs(info->range.min_proto.all)) ||
1773              (info->range.max_proto.all != info->range.min_proto.all &&
1774               nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1775                           ntohs(info->range.max_proto.all)))))
1776                 return false;
1777
1778         if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1779             nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1780                 return false;
1781         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1782             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1783                 return false;
1784         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1785             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1786                 return false;
1787 out:
1788         nla_nest_end(skb, start);
1789
1790         return true;
1791 }
1792 #endif
1793
1794 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1795                           struct sk_buff *skb)
1796 {
1797         struct nlattr *start;
1798
1799         start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
1800         if (!start)
1801                 return -EMSGSIZE;
1802
1803         if (ct_info->commit && nla_put_flag(skb, ct_info->force
1804                                             ? OVS_CT_ATTR_FORCE_COMMIT
1805                                             : OVS_CT_ATTR_COMMIT))
1806                 return -EMSGSIZE;
1807         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1808             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1809                 return -EMSGSIZE;
1810         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1811             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1812                     &ct_info->mark))
1813                 return -EMSGSIZE;
1814         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1815             labels_nonzero(&ct_info->labels.mask) &&
1816             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1817                     &ct_info->labels))
1818                 return -EMSGSIZE;
1819         if (ct_info->helper) {
1820                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1821                                    ct_info->helper->name))
1822                         return -EMSGSIZE;
1823         }
1824         if (ct_info->have_eventmask &&
1825             nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
1826                 return -EMSGSIZE;
1827         if (ct_info->timeout[0]) {
1828                 if (nla_put_string(skb, OVS_CT_ATTR_TIMEOUT, ct_info->timeout))
1829                         return -EMSGSIZE;
1830         }
1831
1832 #if IS_ENABLED(CONFIG_NF_NAT)
1833         if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1834                 return -EMSGSIZE;
1835 #endif
1836         nla_nest_end(skb, start);
1837
1838         return 0;
1839 }
1840
1841 void ovs_ct_free_action(const struct nlattr *a)
1842 {
1843         struct ovs_conntrack_info *ct_info = nla_data(a);
1844
1845         __ovs_ct_free_action(ct_info);
1846 }
1847
1848 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1849 {
1850         if (ct_info->helper) {
1851 #if IS_ENABLED(CONFIG_NF_NAT)
1852                 if (ct_info->nat)
1853                         nf_nat_helper_put(ct_info->helper);
1854 #endif
1855                 nf_conntrack_helper_put(ct_info->helper);
1856         }
1857         if (ct_info->ct) {
1858                 if (ct_info->timeout[0])
1859                         nf_ct_destroy_timeout(ct_info->ct);
1860                 nf_ct_tmpl_free(ct_info->ct);
1861         }
1862 }
1863
1864 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1865 static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
1866 {
1867         int i, err;
1868
1869         ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
1870                                          GFP_KERNEL);
1871         if (!ovs_net->ct_limit_info)
1872                 return -ENOMEM;
1873
1874         ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
1875         ovs_net->ct_limit_info->limits =
1876                 kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
1877                               GFP_KERNEL);
1878         if (!ovs_net->ct_limit_info->limits) {
1879                 kfree(ovs_net->ct_limit_info);
1880                 return -ENOMEM;
1881         }
1882
1883         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
1884                 INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);
1885
1886         ovs_net->ct_limit_info->data =
1887                 nf_conncount_init(net, NFPROTO_INET, sizeof(u32));
1888
1889         if (IS_ERR(ovs_net->ct_limit_info->data)) {
1890                 err = PTR_ERR(ovs_net->ct_limit_info->data);
1891                 kfree(ovs_net->ct_limit_info->limits);
1892                 kfree(ovs_net->ct_limit_info);
1893                 pr_err("openvswitch: failed to init nf_conncount %d\n", err);
1894                 return err;
1895         }
1896         return 0;
1897 }
1898
1899 static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
1900 {
1901         const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
1902         int i;
1903
1904         nf_conncount_destroy(net, NFPROTO_INET, info->data);
1905         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
1906                 struct hlist_head *head = &info->limits[i];
1907                 struct ovs_ct_limit *ct_limit;
1908
1909                 hlist_for_each_entry_rcu(ct_limit, head, hlist_node,
1910                                          lockdep_ovsl_is_held())
1911                         kfree_rcu(ct_limit, rcu);
1912         }
1913         kfree(info->limits);
1914         kfree(info);
1915 }
1916
1917 static struct sk_buff *
1918 ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
1919                              struct ovs_header **ovs_reply_header)
1920 {
1921         struct ovs_header *ovs_header = info->userhdr;
1922         struct sk_buff *skb;
1923
1924         skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1925         if (!skb)
1926                 return ERR_PTR(-ENOMEM);
1927
1928         *ovs_reply_header = genlmsg_put(skb, info->snd_portid,
1929                                         info->snd_seq,
1930                                         &dp_ct_limit_genl_family, 0, cmd);
1931
1932         if (!*ovs_reply_header) {
1933                 nlmsg_free(skb);
1934                 return ERR_PTR(-EMSGSIZE);
1935         }
1936         (*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
1937
1938         return skb;
1939 }
1940
1941 static bool check_zone_id(int zone_id, u16 *pzone)
1942 {
1943         if (zone_id >= 0 && zone_id <= 65535) {
1944                 *pzone = (u16)zone_id;
1945                 return true;
1946         }
1947         return false;
1948 }
1949
1950 static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
1951                                        struct ovs_ct_limit_info *info)
1952 {
1953         struct ovs_zone_limit *zone_limit;
1954         int rem;
1955         u16 zone;
1956
1957         rem = NLA_ALIGN(nla_len(nla_zone_limit));
1958         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1959
1960         while (rem >= sizeof(*zone_limit)) {
1961                 if (unlikely(zone_limit->zone_id ==
1962                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1963                         ovs_lock();
1964                         info->default_limit = zone_limit->limit;
1965                         ovs_unlock();
1966                 } else if (unlikely(!check_zone_id(
1967                                 zone_limit->zone_id, &zone))) {
1968                         OVS_NLERR(true, "zone id is out of range");
1969                 } else {
1970                         struct ovs_ct_limit *ct_limit;
1971
1972                         ct_limit = kmalloc(sizeof(*ct_limit), GFP_KERNEL);
1973                         if (!ct_limit)
1974                                 return -ENOMEM;
1975
1976                         ct_limit->zone = zone;
1977                         ct_limit->limit = zone_limit->limit;
1978
1979                         ovs_lock();
1980                         ct_limit_set(info, ct_limit);
1981                         ovs_unlock();
1982                 }
1983                 rem -= NLA_ALIGN(sizeof(*zone_limit));
1984                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1985                                 NLA_ALIGN(sizeof(*zone_limit)));
1986         }
1987
1988         if (rem)
1989                 OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);
1990
1991         return 0;
1992 }
1993
1994 static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
1995                                        struct ovs_ct_limit_info *info)
1996 {
1997         struct ovs_zone_limit *zone_limit;
1998         int rem;
1999         u16 zone;
2000
2001         rem = NLA_ALIGN(nla_len(nla_zone_limit));
2002         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
2003
2004         while (rem >= sizeof(*zone_limit)) {
2005                 if (unlikely(zone_limit->zone_id ==
2006                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
2007                         ovs_lock();
2008                         info->default_limit = OVS_CT_LIMIT_DEFAULT;
2009                         ovs_unlock();
2010                 } else if (unlikely(!check_zone_id(
2011                                 zone_limit->zone_id, &zone))) {
2012                         OVS_NLERR(true, "zone id is out of range");
2013                 } else {
2014                         ovs_lock();
2015                         ct_limit_del(info, zone);
2016                         ovs_unlock();
2017                 }
2018                 rem -= NLA_ALIGN(sizeof(*zone_limit));
2019                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2020                                 NLA_ALIGN(sizeof(*zone_limit)));
2021         }
2022
2023         if (rem)
2024                 OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);
2025
2026         return 0;
2027 }
2028
2029 static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
2030                                           struct sk_buff *reply)
2031 {
2032         struct ovs_zone_limit zone_limit = {
2033                 .zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE,
2034                 .limit   = info->default_limit,
2035         };
2036
2037         return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
2038 }
2039
2040 static int __ovs_ct_limit_get_zone_limit(struct net *net,
2041                                          struct nf_conncount_data *data,
2042                                          u16 zone_id, u32 limit,
2043                                          struct sk_buff *reply)
2044 {
2045         struct nf_conntrack_zone ct_zone;
2046         struct ovs_zone_limit zone_limit;
2047         u32 conncount_key = zone_id;
2048
2049         zone_limit.zone_id = zone_id;
2050         zone_limit.limit = limit;
2051         nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);
2052
2053         zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
2054                                               &ct_zone);
2055         return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
2056 }
2057
2058 static int ovs_ct_limit_get_zone_limit(struct net *net,
2059                                        struct nlattr *nla_zone_limit,
2060                                        struct ovs_ct_limit_info *info,
2061                                        struct sk_buff *reply)
2062 {
2063         struct ovs_zone_limit *zone_limit;
2064         int rem, err;
2065         u32 limit;
2066         u16 zone;
2067
2068         rem = NLA_ALIGN(nla_len(nla_zone_limit));
2069         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
2070
2071         while (rem >= sizeof(*zone_limit)) {
2072                 if (unlikely(zone_limit->zone_id ==
2073                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
2074                         err = ovs_ct_limit_get_default_limit(info, reply);
2075                         if (err)
2076                                 return err;
2077                 } else if (unlikely(!check_zone_id(zone_limit->zone_id,
2078                                                         &zone))) {
2079                         OVS_NLERR(true, "zone id is out of range");
2080                 } else {
2081                         rcu_read_lock();
2082                         limit = ct_limit_get(info, zone);
2083                         rcu_read_unlock();
2084
2085                         err = __ovs_ct_limit_get_zone_limit(
2086                                 net, info->data, zone, limit, reply);
2087                         if (err)
2088                                 return err;
2089                 }
2090                 rem -= NLA_ALIGN(sizeof(*zone_limit));
2091                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2092                                 NLA_ALIGN(sizeof(*zone_limit)));
2093         }
2094
2095         if (rem)
2096                 OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);
2097
2098         return 0;
2099 }
2100
2101 static int ovs_ct_limit_get_all_zone_limit(struct net *net,
2102                                            struct ovs_ct_limit_info *info,
2103                                            struct sk_buff *reply)
2104 {
2105         struct ovs_ct_limit *ct_limit;
2106         struct hlist_head *head;
2107         int i, err = 0;
2108
2109         err = ovs_ct_limit_get_default_limit(info, reply);
2110         if (err)
2111                 return err;
2112
2113         rcu_read_lock();
2114         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
2115                 head = &info->limits[i];
2116                 hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
2117                         err = __ovs_ct_limit_get_zone_limit(net, info->data,
2118                                 ct_limit->zone, ct_limit->limit, reply);
2119                         if (err)
2120                                 goto exit_err;
2121                 }
2122         }
2123
2124 exit_err:
2125         rcu_read_unlock();
2126         return err;
2127 }
2128
2129 static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
2130 {
2131         struct nlattr **a = info->attrs;
2132         struct sk_buff *reply;
2133         struct ovs_header *ovs_reply_header;
2134         struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2135         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2136         int err;
2137
2138         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
2139                                              &ovs_reply_header);
2140         if (IS_ERR(reply))
2141                 return PTR_ERR(reply);
2142
2143         if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2144                 err = -EINVAL;
2145                 goto exit_err;
2146         }
2147
2148         err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2149                                           ct_limit_info);
2150         if (err)
2151                 goto exit_err;
2152
2153         static_branch_enable(&ovs_ct_limit_enabled);
2154
2155         genlmsg_end(reply, ovs_reply_header);
2156         return genlmsg_reply(reply, info);
2157
2158 exit_err:
2159         nlmsg_free(reply);
2160         return err;
2161 }
2162
2163 static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
2164 {
2165         struct nlattr **a = info->attrs;
2166         struct sk_buff *reply;
2167         struct ovs_header *ovs_reply_header;
2168         struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2169         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2170         int err;
2171
2172         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
2173                                              &ovs_reply_header);
2174         if (IS_ERR(reply))
2175                 return PTR_ERR(reply);
2176
2177         if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2178                 err = -EINVAL;
2179                 goto exit_err;
2180         }
2181
2182         err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2183                                           ct_limit_info);
2184         if (err)
2185                 goto exit_err;
2186
2187         genlmsg_end(reply, ovs_reply_header);
2188         return genlmsg_reply(reply, info);
2189
2190 exit_err:
2191         nlmsg_free(reply);
2192         return err;
2193 }
2194
2195 static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
2196 {
2197         struct nlattr **a = info->attrs;
2198         struct nlattr *nla_reply;
2199         struct sk_buff *reply;
2200         struct ovs_header *ovs_reply_header;
2201         struct net *net = sock_net(skb->sk);
2202         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2203         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2204         int err;
2205
2206         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
2207                                              &ovs_reply_header);
2208         if (IS_ERR(reply))
2209                 return PTR_ERR(reply);
2210
2211         nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
2212         if (!nla_reply) {
2213                 err = -EMSGSIZE;
2214                 goto exit_err;
2215         }
2216
2217         if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2218                 err = ovs_ct_limit_get_zone_limit(
2219                         net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
2220                         reply);
2221                 if (err)
2222                         goto exit_err;
2223         } else {
2224                 err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
2225                                                       reply);
2226                 if (err)
2227                         goto exit_err;
2228         }
2229
2230         nla_nest_end(reply, nla_reply);
2231         genlmsg_end(reply, ovs_reply_header);
2232         return genlmsg_reply(reply, info);
2233
2234 exit_err:
2235         nlmsg_free(reply);
2236         return err;
2237 }
2238
2239 static const struct genl_small_ops ct_limit_genl_ops[] = {
2240         { .cmd = OVS_CT_LIMIT_CMD_SET,
2241                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2242                 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2243                                            * privilege. */
2244                 .doit = ovs_ct_limit_cmd_set,
2245         },
2246         { .cmd = OVS_CT_LIMIT_CMD_DEL,
2247                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2248                 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2249                                            * privilege. */
2250                 .doit = ovs_ct_limit_cmd_del,
2251         },
2252         { .cmd = OVS_CT_LIMIT_CMD_GET,
2253                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2254                 .flags = 0,               /* OK for unprivileged users. */
2255                 .doit = ovs_ct_limit_cmd_get,
2256         },
2257 };
2258
2259 static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
2260         .name = OVS_CT_LIMIT_MCGROUP,
2261 };
2262
2263 struct genl_family dp_ct_limit_genl_family __ro_after_init = {
2264         .hdrsize = sizeof(struct ovs_header),
2265         .name = OVS_CT_LIMIT_FAMILY,
2266         .version = OVS_CT_LIMIT_VERSION,
2267         .maxattr = OVS_CT_LIMIT_ATTR_MAX,
2268         .policy = ct_limit_policy,
2269         .netnsok = true,
2270         .parallel_ops = true,
2271         .small_ops = ct_limit_genl_ops,
2272         .n_small_ops = ARRAY_SIZE(ct_limit_genl_ops),
2273         .mcgrps = &ovs_ct_limit_multicast_group,
2274         .n_mcgrps = 1,
2275         .module = THIS_MODULE,
2276 };
2277 #endif
2278
2279 int ovs_ct_init(struct net *net)
2280 {
2281         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
2282         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2283
2284         if (nf_connlabels_get(net, n_bits - 1)) {
2285                 ovs_net->xt_label = false;
2286                 OVS_NLERR(true, "Failed to set connlabel length");
2287         } else {
2288                 ovs_net->xt_label = true;
2289         }
2290
2291 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2292         return ovs_ct_limit_init(net, ovs_net);
2293 #else
2294         return 0;
2295 #endif
2296 }
2297
2298 void ovs_ct_exit(struct net *net)
2299 {
2300         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2301
2302 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2303         ovs_ct_limit_exit(net, ovs_net);
2304 #endif
2305
2306         if (ovs_net->xt_label)
2307                 nf_connlabels_put(net);
2308 }