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 } 2309