1 /* 2 * Copyright (c) 2015 Nicira, Inc. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 */ 13 14 #include <linux/module.h> 15 #include <linux/openvswitch.h> 16 #include <linux/tcp.h> 17 #include <linux/udp.h> 18 #include <linux/sctp.h> 19 #include <net/ip.h> 20 #include <net/netfilter/nf_conntrack_core.h> 21 #include <net/netfilter/nf_conntrack_helper.h> 22 #include <net/netfilter/nf_conntrack_labels.h> 23 #include <net/netfilter/nf_conntrack_seqadj.h> 24 #include <net/netfilter/nf_conntrack_zones.h> 25 #include <net/netfilter/ipv6/nf_defrag_ipv6.h> 26 27 #ifdef CONFIG_NF_NAT_NEEDED 28 #include <linux/netfilter/nf_nat.h> 29 #include <net/netfilter/nf_nat_core.h> 30 #include <net/netfilter/nf_nat_l3proto.h> 31 #endif 32 33 #include "datapath.h" 34 #include "conntrack.h" 35 #include "flow.h" 36 #include "flow_netlink.h" 37 38 struct ovs_ct_len_tbl { 39 int maxlen; 40 int minlen; 41 }; 42 43 /* Metadata mark for masked write to conntrack mark */ 44 struct md_mark { 45 u32 value; 46 u32 mask; 47 }; 48 49 /* Metadata label for masked write to conntrack label. */ 50 struct md_labels { 51 struct ovs_key_ct_labels value; 52 struct ovs_key_ct_labels mask; 53 }; 54 55 enum ovs_ct_nat { 56 OVS_CT_NAT = 1 << 0, /* NAT for committed connections only. */ 57 OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */ 58 OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */ 59 }; 60 61 /* Conntrack action context for execution. */ 62 struct ovs_conntrack_info { 63 struct nf_conntrack_helper *helper; 64 struct nf_conntrack_zone zone; 65 struct nf_conn *ct; 66 u8 commit : 1; 67 u8 nat : 3; /* enum ovs_ct_nat */ 68 u8 force : 1; 69 u8 have_eventmask : 1; 70 u16 family; 71 u32 eventmask; /* Mask of 1 << IPCT_*. */ 72 struct md_mark mark; 73 struct md_labels labels; 74 #ifdef CONFIG_NF_NAT_NEEDED 75 struct nf_nat_range range; /* Only present for SRC NAT and DST NAT. */ 76 #endif 77 }; 78 79 static bool labels_nonzero(const struct ovs_key_ct_labels *labels); 80 81 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info); 82 83 static u16 key_to_nfproto(const struct sw_flow_key *key) 84 { 85 switch (ntohs(key->eth.type)) { 86 case ETH_P_IP: 87 return NFPROTO_IPV4; 88 case ETH_P_IPV6: 89 return NFPROTO_IPV6; 90 default: 91 return NFPROTO_UNSPEC; 92 } 93 } 94 95 /* Map SKB connection state into the values used by flow definition. */ 96 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo) 97 { 98 u8 ct_state = OVS_CS_F_TRACKED; 99 100 switch (ctinfo) { 101 case IP_CT_ESTABLISHED_REPLY: 102 case IP_CT_RELATED_REPLY: 103 ct_state |= OVS_CS_F_REPLY_DIR; 104 break; 105 default: 106 break; 107 } 108 109 switch (ctinfo) { 110 case IP_CT_ESTABLISHED: 111 case IP_CT_ESTABLISHED_REPLY: 112 ct_state |= OVS_CS_F_ESTABLISHED; 113 break; 114 case IP_CT_RELATED: 115 case IP_CT_RELATED_REPLY: 116 ct_state |= OVS_CS_F_RELATED; 117 break; 118 case IP_CT_NEW: 119 ct_state |= OVS_CS_F_NEW; 120 break; 121 default: 122 break; 123 } 124 125 return ct_state; 126 } 127 128 static u32 ovs_ct_get_mark(const struct nf_conn *ct) 129 { 130 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) 131 return ct ? ct->mark : 0; 132 #else 133 return 0; 134 #endif 135 } 136 137 /* Guard against conntrack labels max size shrinking below 128 bits. */ 138 #if NF_CT_LABELS_MAX_SIZE < 16 139 #error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes 140 #endif 141 142 static void ovs_ct_get_labels(const struct nf_conn *ct, 143 struct ovs_key_ct_labels *labels) 144 { 145 struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL; 146 147 if (cl) 148 memcpy(labels, cl->bits, OVS_CT_LABELS_LEN); 149 else 150 memset(labels, 0, OVS_CT_LABELS_LEN); 151 } 152 153 static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key, 154 const struct nf_conntrack_tuple *orig, 155 u8 icmp_proto) 156 { 157 key->ct_orig_proto = orig->dst.protonum; 158 if (orig->dst.protonum == icmp_proto) { 159 key->ct.orig_tp.src = htons(orig->dst.u.icmp.type); 160 key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code); 161 } else { 162 key->ct.orig_tp.src = orig->src.u.all; 163 key->ct.orig_tp.dst = orig->dst.u.all; 164 } 165 } 166 167 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state, 168 const struct nf_conntrack_zone *zone, 169 const struct nf_conn *ct) 170 { 171 key->ct_state = state; 172 key->ct_zone = zone->id; 173 key->ct.mark = ovs_ct_get_mark(ct); 174 ovs_ct_get_labels(ct, &key->ct.labels); 175 176 if (ct) { 177 const struct nf_conntrack_tuple *orig; 178 179 /* Use the master if we have one. */ 180 if (ct->master) 181 ct = ct->master; 182 orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; 183 184 /* IP version must match with the master connection. */ 185 if (key->eth.type == htons(ETH_P_IP) && 186 nf_ct_l3num(ct) == NFPROTO_IPV4) { 187 key->ipv4.ct_orig.src = orig->src.u3.ip; 188 key->ipv4.ct_orig.dst = orig->dst.u3.ip; 189 __ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP); 190 return; 191 } else if (key->eth.type == htons(ETH_P_IPV6) && 192 !sw_flow_key_is_nd(key) && 193 nf_ct_l3num(ct) == NFPROTO_IPV6) { 194 key->ipv6.ct_orig.src = orig->src.u3.in6; 195 key->ipv6.ct_orig.dst = orig->dst.u3.in6; 196 __ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP); 197 return; 198 } 199 } 200 /* Clear 'ct_orig_proto' to mark the non-existence of conntrack 201 * original direction key fields. 202 */ 203 key->ct_orig_proto = 0; 204 } 205 206 /* Update 'key' based on skb->_nfct. If 'post_ct' is true, then OVS has 207 * previously sent the packet to conntrack via the ct action. If 208 * 'keep_nat_flags' is true, the existing NAT flags retained, else they are 209 * initialized from the connection status. 210 */ 211 static void ovs_ct_update_key(const struct sk_buff *skb, 212 const struct ovs_conntrack_info *info, 213 struct sw_flow_key *key, bool post_ct, 214 bool keep_nat_flags) 215 { 216 const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt; 217 enum ip_conntrack_info ctinfo; 218 struct nf_conn *ct; 219 u8 state = 0; 220 221 ct = nf_ct_get(skb, &ctinfo); 222 if (ct) { 223 state = ovs_ct_get_state(ctinfo); 224 /* All unconfirmed entries are NEW connections. */ 225 if (!nf_ct_is_confirmed(ct)) 226 state |= OVS_CS_F_NEW; 227 /* OVS persists the related flag for the duration of the 228 * connection. 229 */ 230 if (ct->master) 231 state |= OVS_CS_F_RELATED; 232 if (keep_nat_flags) { 233 state |= key->ct_state & OVS_CS_F_NAT_MASK; 234 } else { 235 if (ct->status & IPS_SRC_NAT) 236 state |= OVS_CS_F_SRC_NAT; 237 if (ct->status & IPS_DST_NAT) 238 state |= OVS_CS_F_DST_NAT; 239 } 240 zone = nf_ct_zone(ct); 241 } else if (post_ct) { 242 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID; 243 if (info) 244 zone = &info->zone; 245 } 246 __ovs_ct_update_key(key, state, zone, ct); 247 } 248 249 /* This is called to initialize CT key fields possibly coming in from the local 250 * stack. 251 */ 252 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key) 253 { 254 ovs_ct_update_key(skb, NULL, key, false, false); 255 } 256 257 #define IN6_ADDR_INITIALIZER(ADDR) \ 258 { (ADDR).s6_addr32[0], (ADDR).s6_addr32[1], \ 259 (ADDR).s6_addr32[2], (ADDR).s6_addr32[3] } 260 261 int ovs_ct_put_key(const struct sw_flow_key *swkey, 262 const struct sw_flow_key *output, struct sk_buff *skb) 263 { 264 if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state)) 265 return -EMSGSIZE; 266 267 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) && 268 nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone)) 269 return -EMSGSIZE; 270 271 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && 272 nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark)) 273 return -EMSGSIZE; 274 275 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) && 276 nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels), 277 &output->ct.labels)) 278 return -EMSGSIZE; 279 280 if (swkey->ct_orig_proto) { 281 if (swkey->eth.type == htons(ETH_P_IP)) { 282 struct ovs_key_ct_tuple_ipv4 orig = { 283 output->ipv4.ct_orig.src, 284 output->ipv4.ct_orig.dst, 285 output->ct.orig_tp.src, 286 output->ct.orig_tp.dst, 287 output->ct_orig_proto, 288 }; 289 if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4, 290 sizeof(orig), &orig)) 291 return -EMSGSIZE; 292 } else if (swkey->eth.type == htons(ETH_P_IPV6)) { 293 struct ovs_key_ct_tuple_ipv6 orig = { 294 IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.src), 295 IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.dst), 296 output->ct.orig_tp.src, 297 output->ct.orig_tp.dst, 298 output->ct_orig_proto, 299 }; 300 if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6, 301 sizeof(orig), &orig)) 302 return -EMSGSIZE; 303 } 304 } 305 306 return 0; 307 } 308 309 static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key, 310 u32 ct_mark, u32 mask) 311 { 312 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) 313 u32 new_mark; 314 315 new_mark = ct_mark | (ct->mark & ~(mask)); 316 if (ct->mark != new_mark) { 317 ct->mark = new_mark; 318 if (nf_ct_is_confirmed(ct)) 319 nf_conntrack_event_cache(IPCT_MARK, ct); 320 key->ct.mark = new_mark; 321 } 322 323 return 0; 324 #else 325 return -ENOTSUPP; 326 #endif 327 } 328 329 static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct) 330 { 331 struct nf_conn_labels *cl; 332 333 cl = nf_ct_labels_find(ct); 334 if (!cl) { 335 nf_ct_labels_ext_add(ct); 336 cl = nf_ct_labels_find(ct); 337 } 338 339 return cl; 340 } 341 342 /* Initialize labels for a new, yet to be committed conntrack entry. Note that 343 * since the new connection is not yet confirmed, and thus no-one else has 344 * access to it's labels, we simply write them over. 345 */ 346 static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key, 347 const struct ovs_key_ct_labels *labels, 348 const struct ovs_key_ct_labels *mask) 349 { 350 struct nf_conn_labels *cl, *master_cl; 351 bool have_mask = labels_nonzero(mask); 352 353 /* Inherit master's labels to the related connection? */ 354 master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL; 355 356 if (!master_cl && !have_mask) 357 return 0; /* Nothing to do. */ 358 359 cl = ovs_ct_get_conn_labels(ct); 360 if (!cl) 361 return -ENOSPC; 362 363 /* Inherit the master's labels, if any. */ 364 if (master_cl) 365 *cl = *master_cl; 366 367 if (have_mask) { 368 u32 *dst = (u32 *)cl->bits; 369 int i; 370 371 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++) 372 dst[i] = (dst[i] & ~mask->ct_labels_32[i]) | 373 (labels->ct_labels_32[i] 374 & mask->ct_labels_32[i]); 375 } 376 377 /* Labels are included in the IPCTNL_MSG_CT_NEW event only if the 378 * IPCT_LABEL bit is set in the event cache. 379 */ 380 nf_conntrack_event_cache(IPCT_LABEL, ct); 381 382 memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN); 383 384 return 0; 385 } 386 387 static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key, 388 const struct ovs_key_ct_labels *labels, 389 const struct ovs_key_ct_labels *mask) 390 { 391 struct nf_conn_labels *cl; 392 int err; 393 394 cl = ovs_ct_get_conn_labels(ct); 395 if (!cl) 396 return -ENOSPC; 397 398 err = nf_connlabels_replace(ct, labels->ct_labels_32, 399 mask->ct_labels_32, 400 OVS_CT_LABELS_LEN_32); 401 if (err) 402 return err; 403 404 memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN); 405 406 return 0; 407 } 408 409 /* 'skb' should already be pulled to nh_ofs. */ 410 static int ovs_ct_helper(struct sk_buff *skb, u16 proto) 411 { 412 const struct nf_conntrack_helper *helper; 413 const struct nf_conn_help *help; 414 enum ip_conntrack_info ctinfo; 415 unsigned int protoff; 416 struct nf_conn *ct; 417 int err; 418 419 ct = nf_ct_get(skb, &ctinfo); 420 if (!ct || ctinfo == IP_CT_RELATED_REPLY) 421 return NF_ACCEPT; 422 423 help = nfct_help(ct); 424 if (!help) 425 return NF_ACCEPT; 426 427 helper = rcu_dereference(help->helper); 428 if (!helper) 429 return NF_ACCEPT; 430 431 switch (proto) { 432 case NFPROTO_IPV4: 433 protoff = ip_hdrlen(skb); 434 break; 435 case NFPROTO_IPV6: { 436 u8 nexthdr = ipv6_hdr(skb)->nexthdr; 437 __be16 frag_off; 438 int ofs; 439 440 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, 441 &frag_off); 442 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) { 443 pr_debug("proto header not found\n"); 444 return NF_ACCEPT; 445 } 446 protoff = ofs; 447 break; 448 } 449 default: 450 WARN_ONCE(1, "helper invoked on non-IP family!"); 451 return NF_DROP; 452 } 453 454 err = helper->help(skb, protoff, ct, ctinfo); 455 if (err != NF_ACCEPT) 456 return err; 457 458 /* Adjust seqs after helper. This is needed due to some helpers (e.g., 459 * FTP with NAT) adusting the TCP payload size when mangling IP 460 * addresses and/or port numbers in the text-based control connection. 461 */ 462 if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) && 463 !nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) 464 return NF_DROP; 465 return NF_ACCEPT; 466 } 467 468 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero 469 * value if 'skb' is freed. 470 */ 471 static int handle_fragments(struct net *net, struct sw_flow_key *key, 472 u16 zone, struct sk_buff *skb) 473 { 474 struct ovs_skb_cb ovs_cb = *OVS_CB(skb); 475 int err; 476 477 if (key->eth.type == htons(ETH_P_IP)) { 478 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone; 479 480 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); 481 err = ip_defrag(net, skb, user); 482 if (err) 483 return err; 484 485 ovs_cb.mru = IPCB(skb)->frag_max_size; 486 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 487 } else if (key->eth.type == htons(ETH_P_IPV6)) { 488 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone; 489 490 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); 491 err = nf_ct_frag6_gather(net, skb, user); 492 if (err) { 493 if (err != -EINPROGRESS) 494 kfree_skb(skb); 495 return err; 496 } 497 498 key->ip.proto = ipv6_hdr(skb)->nexthdr; 499 ovs_cb.mru = IP6CB(skb)->frag_max_size; 500 #endif 501 } else { 502 kfree_skb(skb); 503 return -EPFNOSUPPORT; 504 } 505 506 key->ip.frag = OVS_FRAG_TYPE_NONE; 507 skb_clear_hash(skb); 508 skb->ignore_df = 1; 509 *OVS_CB(skb) = ovs_cb; 510 511 return 0; 512 } 513 514 static struct nf_conntrack_expect * 515 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone, 516 u16 proto, const struct sk_buff *skb) 517 { 518 struct nf_conntrack_tuple tuple; 519 struct nf_conntrack_expect *exp; 520 521 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple)) 522 return NULL; 523 524 exp = __nf_ct_expect_find(net, zone, &tuple); 525 if (exp) { 526 struct nf_conntrack_tuple_hash *h; 527 528 /* Delete existing conntrack entry, if it clashes with the 529 * expectation. This can happen since conntrack ALGs do not 530 * check for clashes between (new) expectations and existing 531 * conntrack entries. nf_conntrack_in() will check the 532 * expectations only if a conntrack entry can not be found, 533 * which can lead to OVS finding the expectation (here) in the 534 * init direction, but which will not be removed by the 535 * nf_conntrack_in() call, if a matching conntrack entry is 536 * found instead. In this case all init direction packets 537 * would be reported as new related packets, while reply 538 * direction packets would be reported as un-related 539 * established packets. 540 */ 541 h = nf_conntrack_find_get(net, zone, &tuple); 542 if (h) { 543 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h); 544 545 nf_ct_delete(ct, 0, 0); 546 nf_conntrack_put(&ct->ct_general); 547 } 548 } 549 550 return exp; 551 } 552 553 /* This replicates logic from nf_conntrack_core.c that is not exported. */ 554 static enum ip_conntrack_info 555 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h) 556 { 557 const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h); 558 559 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) 560 return IP_CT_ESTABLISHED_REPLY; 561 /* Once we've had two way comms, always ESTABLISHED. */ 562 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) 563 return IP_CT_ESTABLISHED; 564 if (test_bit(IPS_EXPECTED_BIT, &ct->status)) 565 return IP_CT_RELATED; 566 return IP_CT_NEW; 567 } 568 569 /* Find an existing connection which this packet belongs to without 570 * re-attributing statistics or modifying the connection state. This allows an 571 * skb->_nfct lost due to an upcall to be recovered during actions execution. 572 * 573 * Must be called with rcu_read_lock. 574 * 575 * On success, populates skb->_nfct and returns the connection. Returns NULL 576 * if there is no existing entry. 577 */ 578 static struct nf_conn * 579 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone, 580 u8 l3num, struct sk_buff *skb, bool natted) 581 { 582 const struct nf_conntrack_l3proto *l3proto; 583 const struct nf_conntrack_l4proto *l4proto; 584 struct nf_conntrack_tuple tuple; 585 struct nf_conntrack_tuple_hash *h; 586 struct nf_conn *ct; 587 unsigned int dataoff; 588 u8 protonum; 589 590 l3proto = __nf_ct_l3proto_find(l3num); 591 if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff, 592 &protonum) <= 0) { 593 pr_debug("ovs_ct_find_existing: Can't get protonum\n"); 594 return NULL; 595 } 596 l4proto = __nf_ct_l4proto_find(l3num, protonum); 597 if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num, 598 protonum, net, &tuple, l3proto, l4proto)) { 599 pr_debug("ovs_ct_find_existing: Can't get tuple\n"); 600 return NULL; 601 } 602 603 /* Must invert the tuple if skb has been transformed by NAT. */ 604 if (natted) { 605 struct nf_conntrack_tuple inverse; 606 607 if (!nf_ct_invert_tuple(&inverse, &tuple, l3proto, l4proto)) { 608 pr_debug("ovs_ct_find_existing: Inversion failed!\n"); 609 return NULL; 610 } 611 tuple = inverse; 612 } 613 614 /* look for tuple match */ 615 h = nf_conntrack_find_get(net, zone, &tuple); 616 if (!h) 617 return NULL; /* Not found. */ 618 619 ct = nf_ct_tuplehash_to_ctrack(h); 620 621 /* Inverted packet tuple matches the reverse direction conntrack tuple, 622 * select the other tuplehash to get the right 'ctinfo' bits for this 623 * packet. 624 */ 625 if (natted) 626 h = &ct->tuplehash[!h->tuple.dst.dir]; 627 628 nf_ct_set(skb, ct, ovs_ct_get_info(h)); 629 return ct; 630 } 631 632 static 633 struct nf_conn *ovs_ct_executed(struct net *net, 634 const struct sw_flow_key *key, 635 const struct ovs_conntrack_info *info, 636 struct sk_buff *skb, 637 bool *ct_executed) 638 { 639 struct nf_conn *ct = NULL; 640 641 /* If no ct, check if we have evidence that an existing conntrack entry 642 * might be found for this skb. This happens when we lose a skb->_nfct 643 * due to an upcall, or if the direction is being forced. If the 644 * connection was not confirmed, it is not cached and needs to be run 645 * through conntrack again. 646 */ 647 *ct_executed = (key->ct_state & OVS_CS_F_TRACKED) && 648 !(key->ct_state & OVS_CS_F_INVALID) && 649 (key->ct_zone == info->zone.id); 650 651 if (*ct_executed || (!key->ct_state && info->force)) { 652 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb, 653 !!(key->ct_state & 654 OVS_CS_F_NAT_MASK)); 655 } 656 657 return ct; 658 } 659 660 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */ 661 static bool skb_nfct_cached(struct net *net, 662 const struct sw_flow_key *key, 663 const struct ovs_conntrack_info *info, 664 struct sk_buff *skb) 665 { 666 enum ip_conntrack_info ctinfo; 667 struct nf_conn *ct; 668 bool ct_executed = true; 669 670 ct = nf_ct_get(skb, &ctinfo); 671 if (!ct) 672 ct = ovs_ct_executed(net, key, info, skb, &ct_executed); 673 674 if (ct) 675 nf_ct_get(skb, &ctinfo); 676 else 677 return false; 678 679 if (!net_eq(net, read_pnet(&ct->ct_net))) 680 return false; 681 if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct))) 682 return false; 683 if (info->helper) { 684 struct nf_conn_help *help; 685 686 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER); 687 if (help && rcu_access_pointer(help->helper) != info->helper) 688 return false; 689 } 690 /* Force conntrack entry direction to the current packet? */ 691 if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) { 692 /* Delete the conntrack entry if confirmed, else just release 693 * the reference. 694 */ 695 if (nf_ct_is_confirmed(ct)) 696 nf_ct_delete(ct, 0, 0); 697 698 nf_conntrack_put(&ct->ct_general); 699 nf_ct_set(skb, NULL, 0); 700 return false; 701 } 702 703 return ct_executed; 704 } 705 706 #ifdef CONFIG_NF_NAT_NEEDED 707 /* Modelled after nf_nat_ipv[46]_fn(). 708 * range is only used for new, uninitialized NAT state. 709 * Returns either NF_ACCEPT or NF_DROP. 710 */ 711 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct, 712 enum ip_conntrack_info ctinfo, 713 const struct nf_nat_range *range, 714 enum nf_nat_manip_type maniptype) 715 { 716 int hooknum, nh_off, err = NF_ACCEPT; 717 718 nh_off = skb_network_offset(skb); 719 skb_pull_rcsum(skb, nh_off); 720 721 /* See HOOK2MANIP(). */ 722 if (maniptype == NF_NAT_MANIP_SRC) 723 hooknum = NF_INET_LOCAL_IN; /* Source NAT */ 724 else 725 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */ 726 727 switch (ctinfo) { 728 case IP_CT_RELATED: 729 case IP_CT_RELATED_REPLY: 730 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) && 731 skb->protocol == htons(ETH_P_IP) && 732 ip_hdr(skb)->protocol == IPPROTO_ICMP) { 733 if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, 734 hooknum)) 735 err = NF_DROP; 736 goto push; 737 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) && 738 skb->protocol == htons(ETH_P_IPV6)) { 739 __be16 frag_off; 740 u8 nexthdr = ipv6_hdr(skb)->nexthdr; 741 int hdrlen = ipv6_skip_exthdr(skb, 742 sizeof(struct ipv6hdr), 743 &nexthdr, &frag_off); 744 745 if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) { 746 if (!nf_nat_icmpv6_reply_translation(skb, ct, 747 ctinfo, 748 hooknum, 749 hdrlen)) 750 err = NF_DROP; 751 goto push; 752 } 753 } 754 /* Non-ICMP, fall thru to initialize if needed. */ 755 case IP_CT_NEW: 756 /* Seen it before? This can happen for loopback, retrans, 757 * or local packets. 758 */ 759 if (!nf_nat_initialized(ct, maniptype)) { 760 /* Initialize according to the NAT action. */ 761 err = (range && range->flags & NF_NAT_RANGE_MAP_IPS) 762 /* Action is set up to establish a new 763 * mapping. 764 */ 765 ? nf_nat_setup_info(ct, range, maniptype) 766 : nf_nat_alloc_null_binding(ct, hooknum); 767 if (err != NF_ACCEPT) 768 goto push; 769 } 770 break; 771 772 case IP_CT_ESTABLISHED: 773 case IP_CT_ESTABLISHED_REPLY: 774 break; 775 776 default: 777 err = NF_DROP; 778 goto push; 779 } 780 781 err = nf_nat_packet(ct, ctinfo, hooknum, skb); 782 push: 783 skb_push(skb, nh_off); 784 skb_postpush_rcsum(skb, skb->data, nh_off); 785 786 return err; 787 } 788 789 static void ovs_nat_update_key(struct sw_flow_key *key, 790 const struct sk_buff *skb, 791 enum nf_nat_manip_type maniptype) 792 { 793 if (maniptype == NF_NAT_MANIP_SRC) { 794 __be16 src; 795 796 key->ct_state |= OVS_CS_F_SRC_NAT; 797 if (key->eth.type == htons(ETH_P_IP)) 798 key->ipv4.addr.src = ip_hdr(skb)->saddr; 799 else if (key->eth.type == htons(ETH_P_IPV6)) 800 memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr, 801 sizeof(key->ipv6.addr.src)); 802 else 803 return; 804 805 if (key->ip.proto == IPPROTO_UDP) 806 src = udp_hdr(skb)->source; 807 else if (key->ip.proto == IPPROTO_TCP) 808 src = tcp_hdr(skb)->source; 809 else if (key->ip.proto == IPPROTO_SCTP) 810 src = sctp_hdr(skb)->source; 811 else 812 return; 813 814 key->tp.src = src; 815 } else { 816 __be16 dst; 817 818 key->ct_state |= OVS_CS_F_DST_NAT; 819 if (key->eth.type == htons(ETH_P_IP)) 820 key->ipv4.addr.dst = ip_hdr(skb)->daddr; 821 else if (key->eth.type == htons(ETH_P_IPV6)) 822 memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr, 823 sizeof(key->ipv6.addr.dst)); 824 else 825 return; 826 827 if (key->ip.proto == IPPROTO_UDP) 828 dst = udp_hdr(skb)->dest; 829 else if (key->ip.proto == IPPROTO_TCP) 830 dst = tcp_hdr(skb)->dest; 831 else if (key->ip.proto == IPPROTO_SCTP) 832 dst = sctp_hdr(skb)->dest; 833 else 834 return; 835 836 key->tp.dst = dst; 837 } 838 } 839 840 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */ 841 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key, 842 const struct ovs_conntrack_info *info, 843 struct sk_buff *skb, struct nf_conn *ct, 844 enum ip_conntrack_info ctinfo) 845 { 846 enum nf_nat_manip_type maniptype; 847 int err; 848 849 /* Add NAT extension if not confirmed yet. */ 850 if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct)) 851 return NF_ACCEPT; /* Can't NAT. */ 852 853 /* Determine NAT type. 854 * Check if the NAT type can be deduced from the tracked connection. 855 * Make sure new expected connections (IP_CT_RELATED) are NATted only 856 * when committing. 857 */ 858 if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW && 859 ct->status & IPS_NAT_MASK && 860 (ctinfo != IP_CT_RELATED || info->commit)) { 861 /* NAT an established or related connection like before. */ 862 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) 863 /* This is the REPLY direction for a connection 864 * for which NAT was applied in the forward 865 * direction. Do the reverse NAT. 866 */ 867 maniptype = ct->status & IPS_SRC_NAT 868 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC; 869 else 870 maniptype = ct->status & IPS_SRC_NAT 871 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST; 872 } else if (info->nat & OVS_CT_SRC_NAT) { 873 maniptype = NF_NAT_MANIP_SRC; 874 } else if (info->nat & OVS_CT_DST_NAT) { 875 maniptype = NF_NAT_MANIP_DST; 876 } else { 877 return NF_ACCEPT; /* Connection is not NATed. */ 878 } 879 err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype); 880 881 /* Mark NAT done if successful and update the flow key. */ 882 if (err == NF_ACCEPT) 883 ovs_nat_update_key(key, skb, maniptype); 884 885 return err; 886 } 887 #else /* !CONFIG_NF_NAT_NEEDED */ 888 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key, 889 const struct ovs_conntrack_info *info, 890 struct sk_buff *skb, struct nf_conn *ct, 891 enum ip_conntrack_info ctinfo) 892 { 893 return NF_ACCEPT; 894 } 895 #endif 896 897 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if 898 * not done already. Update key with new CT state after passing the packet 899 * through conntrack. 900 * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be 901 * set to NULL and 0 will be returned. 902 */ 903 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, 904 const struct ovs_conntrack_info *info, 905 struct sk_buff *skb) 906 { 907 /* If we are recirculating packets to match on conntrack fields and 908 * committing with a separate conntrack action, then we don't need to 909 * actually run the packet through conntrack twice unless it's for a 910 * different zone. 911 */ 912 bool cached = skb_nfct_cached(net, key, info, skb); 913 enum ip_conntrack_info ctinfo; 914 struct nf_conn *ct; 915 916 if (!cached) { 917 struct nf_conn *tmpl = info->ct; 918 int err; 919 920 /* Associate skb with specified zone. */ 921 if (tmpl) { 922 if (skb_nfct(skb)) 923 nf_conntrack_put(skb_nfct(skb)); 924 nf_conntrack_get(&tmpl->ct_general); 925 nf_ct_set(skb, tmpl, IP_CT_NEW); 926 } 927 928 err = nf_conntrack_in(net, info->family, 929 NF_INET_PRE_ROUTING, skb); 930 if (err != NF_ACCEPT) 931 return -ENOENT; 932 933 /* Clear CT state NAT flags to mark that we have not yet done 934 * NAT after the nf_conntrack_in() call. We can actually clear 935 * the whole state, as it will be re-initialized below. 936 */ 937 key->ct_state = 0; 938 939 /* Update the key, but keep the NAT flags. */ 940 ovs_ct_update_key(skb, info, key, true, true); 941 } 942 943 ct = nf_ct_get(skb, &ctinfo); 944 if (ct) { 945 /* Packets starting a new connection must be NATted before the 946 * helper, so that the helper knows about the NAT. We enforce 947 * this by delaying both NAT and helper calls for unconfirmed 948 * connections until the committing CT action. For later 949 * packets NAT and Helper may be called in either order. 950 * 951 * NAT will be done only if the CT action has NAT, and only 952 * once per packet (per zone), as guarded by the NAT bits in 953 * the key->ct_state. 954 */ 955 if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) && 956 (nf_ct_is_confirmed(ct) || info->commit) && 957 ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) { 958 return -EINVAL; 959 } 960 961 /* Userspace may decide to perform a ct lookup without a helper 962 * specified followed by a (recirculate and) commit with one. 963 * Therefore, for unconfirmed connections which we will commit, 964 * we need to attach the helper here. 965 */ 966 if (!nf_ct_is_confirmed(ct) && info->commit && 967 info->helper && !nfct_help(ct)) { 968 int err = __nf_ct_try_assign_helper(ct, info->ct, 969 GFP_ATOMIC); 970 if (err) 971 return err; 972 } 973 974 /* Call the helper only if: 975 * - nf_conntrack_in() was executed above ("!cached") for a 976 * confirmed connection, or 977 * - When committing an unconfirmed connection. 978 */ 979 if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) && 980 ovs_ct_helper(skb, info->family) != NF_ACCEPT) { 981 return -EINVAL; 982 } 983 } 984 985 return 0; 986 } 987 988 /* Lookup connection and read fields into key. */ 989 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key, 990 const struct ovs_conntrack_info *info, 991 struct sk_buff *skb) 992 { 993 struct nf_conntrack_expect *exp; 994 995 /* If we pass an expected packet through nf_conntrack_in() the 996 * expectation is typically removed, but the packet could still be 997 * lost in upcall processing. To prevent this from happening we 998 * perform an explicit expectation lookup. Expected connections are 999 * always new, and will be passed through conntrack only when they are 1000 * committed, as it is OK to remove the expectation at that time. 1001 */ 1002 exp = ovs_ct_expect_find(net, &info->zone, info->family, skb); 1003 if (exp) { 1004 u8 state; 1005 1006 /* NOTE: New connections are NATted and Helped only when 1007 * committed, so we are not calling into NAT here. 1008 */ 1009 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED; 1010 __ovs_ct_update_key(key, state, &info->zone, exp->master); 1011 } else { 1012 struct nf_conn *ct; 1013 int err; 1014 1015 err = __ovs_ct_lookup(net, key, info, skb); 1016 if (err) 1017 return err; 1018 1019 ct = (struct nf_conn *)skb_nfct(skb); 1020 if (ct) 1021 nf_ct_deliver_cached_events(ct); 1022 } 1023 1024 return 0; 1025 } 1026 1027 static bool labels_nonzero(const struct ovs_key_ct_labels *labels) 1028 { 1029 size_t i; 1030 1031 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++) 1032 if (labels->ct_labels_32[i]) 1033 return true; 1034 1035 return false; 1036 } 1037 1038 /* Lookup connection and confirm if unconfirmed. */ 1039 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key, 1040 const struct ovs_conntrack_info *info, 1041 struct sk_buff *skb) 1042 { 1043 enum ip_conntrack_info ctinfo; 1044 struct nf_conn *ct; 1045 int err; 1046 1047 err = __ovs_ct_lookup(net, key, info, skb); 1048 if (err) 1049 return err; 1050 1051 /* The connection could be invalid, in which case this is a no-op.*/ 1052 ct = nf_ct_get(skb, &ctinfo); 1053 if (!ct) 1054 return 0; 1055 1056 /* Set the conntrack event mask if given. NEW and DELETE events have 1057 * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener 1058 * typically would receive many kinds of updates. Setting the event 1059 * mask allows those events to be filtered. The set event mask will 1060 * remain in effect for the lifetime of the connection unless changed 1061 * by a further CT action with both the commit flag and the eventmask 1062 * option. */ 1063 if (info->have_eventmask) { 1064 struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct); 1065 1066 if (cache) 1067 cache->ctmask = info->eventmask; 1068 } 1069 1070 /* Apply changes before confirming the connection so that the initial 1071 * conntrack NEW netlink event carries the values given in the CT 1072 * action. 1073 */ 1074 if (info->mark.mask) { 1075 err = ovs_ct_set_mark(ct, key, info->mark.value, 1076 info->mark.mask); 1077 if (err) 1078 return err; 1079 } 1080 if (!nf_ct_is_confirmed(ct)) { 1081 err = ovs_ct_init_labels(ct, key, &info->labels.value, 1082 &info->labels.mask); 1083 if (err) 1084 return err; 1085 } else if (labels_nonzero(&info->labels.mask)) { 1086 err = ovs_ct_set_labels(ct, key, &info->labels.value, 1087 &info->labels.mask); 1088 if (err) 1089 return err; 1090 } 1091 /* This will take care of sending queued events even if the connection 1092 * is already confirmed. 1093 */ 1094 if (nf_conntrack_confirm(skb) != NF_ACCEPT) 1095 return -EINVAL; 1096 1097 return 0; 1098 } 1099 1100 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero 1101 * value if 'skb' is freed. 1102 */ 1103 int ovs_ct_execute(struct net *net, struct sk_buff *skb, 1104 struct sw_flow_key *key, 1105 const struct ovs_conntrack_info *info) 1106 { 1107 int nh_ofs; 1108 int err; 1109 1110 /* The conntrack module expects to be working at L3. */ 1111 nh_ofs = skb_network_offset(skb); 1112 skb_pull_rcsum(skb, nh_ofs); 1113 1114 if (key->ip.frag != OVS_FRAG_TYPE_NONE) { 1115 err = handle_fragments(net, key, info->zone.id, skb); 1116 if (err) 1117 return err; 1118 } 1119 1120 if (info->commit) 1121 err = ovs_ct_commit(net, key, info, skb); 1122 else 1123 err = ovs_ct_lookup(net, key, info, skb); 1124 1125 skb_push(skb, nh_ofs); 1126 skb_postpush_rcsum(skb, skb->data, nh_ofs); 1127 if (err) 1128 kfree_skb(skb); 1129 return err; 1130 } 1131 1132 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name, 1133 const struct sw_flow_key *key, bool log) 1134 { 1135 struct nf_conntrack_helper *helper; 1136 struct nf_conn_help *help; 1137 1138 helper = nf_conntrack_helper_try_module_get(name, info->family, 1139 key->ip.proto); 1140 if (!helper) { 1141 OVS_NLERR(log, "Unknown helper \"%s\"", name); 1142 return -EINVAL; 1143 } 1144 1145 help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL); 1146 if (!help) { 1147 nf_conntrack_helper_put(helper); 1148 return -ENOMEM; 1149 } 1150 1151 rcu_assign_pointer(help->helper, helper); 1152 info->helper = helper; 1153 return 0; 1154 } 1155 1156 #ifdef CONFIG_NF_NAT_NEEDED 1157 static int parse_nat(const struct nlattr *attr, 1158 struct ovs_conntrack_info *info, bool log) 1159 { 1160 struct nlattr *a; 1161 int rem; 1162 bool have_ip_max = false; 1163 bool have_proto_max = false; 1164 bool ip_vers = (info->family == NFPROTO_IPV6); 1165 1166 nla_for_each_nested(a, attr, rem) { 1167 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = { 1168 [OVS_NAT_ATTR_SRC] = {0, 0}, 1169 [OVS_NAT_ATTR_DST] = {0, 0}, 1170 [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr), 1171 sizeof(struct in6_addr)}, 1172 [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr), 1173 sizeof(struct in6_addr)}, 1174 [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)}, 1175 [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)}, 1176 [OVS_NAT_ATTR_PERSISTENT] = {0, 0}, 1177 [OVS_NAT_ATTR_PROTO_HASH] = {0, 0}, 1178 [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0}, 1179 }; 1180 int type = nla_type(a); 1181 1182 if (type > OVS_NAT_ATTR_MAX) { 1183 OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)", 1184 type, OVS_NAT_ATTR_MAX); 1185 return -EINVAL; 1186 } 1187 1188 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) { 1189 OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)", 1190 type, nla_len(a), 1191 ovs_nat_attr_lens[type][ip_vers]); 1192 return -EINVAL; 1193 } 1194 1195 switch (type) { 1196 case OVS_NAT_ATTR_SRC: 1197 case OVS_NAT_ATTR_DST: 1198 if (info->nat) { 1199 OVS_NLERR(log, "Only one type of NAT may be specified"); 1200 return -ERANGE; 1201 } 1202 info->nat |= OVS_CT_NAT; 1203 info->nat |= ((type == OVS_NAT_ATTR_SRC) 1204 ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT); 1205 break; 1206 1207 case OVS_NAT_ATTR_IP_MIN: 1208 nla_memcpy(&info->range.min_addr, a, 1209 sizeof(info->range.min_addr)); 1210 info->range.flags |= NF_NAT_RANGE_MAP_IPS; 1211 break; 1212 1213 case OVS_NAT_ATTR_IP_MAX: 1214 have_ip_max = true; 1215 nla_memcpy(&info->range.max_addr, a, 1216 sizeof(info->range.max_addr)); 1217 info->range.flags |= NF_NAT_RANGE_MAP_IPS; 1218 break; 1219 1220 case OVS_NAT_ATTR_PROTO_MIN: 1221 info->range.min_proto.all = htons(nla_get_u16(a)); 1222 info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED; 1223 break; 1224 1225 case OVS_NAT_ATTR_PROTO_MAX: 1226 have_proto_max = true; 1227 info->range.max_proto.all = htons(nla_get_u16(a)); 1228 info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED; 1229 break; 1230 1231 case OVS_NAT_ATTR_PERSISTENT: 1232 info->range.flags |= NF_NAT_RANGE_PERSISTENT; 1233 break; 1234 1235 case OVS_NAT_ATTR_PROTO_HASH: 1236 info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM; 1237 break; 1238 1239 case OVS_NAT_ATTR_PROTO_RANDOM: 1240 info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY; 1241 break; 1242 1243 default: 1244 OVS_NLERR(log, "Unknown nat attribute (%d)", type); 1245 return -EINVAL; 1246 } 1247 } 1248 1249 if (rem > 0) { 1250 OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem); 1251 return -EINVAL; 1252 } 1253 if (!info->nat) { 1254 /* Do not allow flags if no type is given. */ 1255 if (info->range.flags) { 1256 OVS_NLERR(log, 1257 "NAT flags may be given only when NAT range (SRC or DST) is also specified.\n" 1258 ); 1259 return -EINVAL; 1260 } 1261 info->nat = OVS_CT_NAT; /* NAT existing connections. */ 1262 } else if (!info->commit) { 1263 OVS_NLERR(log, 1264 "NAT attributes may be specified only when CT COMMIT flag is also specified.\n" 1265 ); 1266 return -EINVAL; 1267 } 1268 /* Allow missing IP_MAX. */ 1269 if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) { 1270 memcpy(&info->range.max_addr, &info->range.min_addr, 1271 sizeof(info->range.max_addr)); 1272 } 1273 /* Allow missing PROTO_MAX. */ 1274 if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED && 1275 !have_proto_max) { 1276 info->range.max_proto.all = info->range.min_proto.all; 1277 } 1278 return 0; 1279 } 1280 #endif 1281 1282 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = { 1283 [OVS_CT_ATTR_COMMIT] = { .minlen = 0, .maxlen = 0 }, 1284 [OVS_CT_ATTR_FORCE_COMMIT] = { .minlen = 0, .maxlen = 0 }, 1285 [OVS_CT_ATTR_ZONE] = { .minlen = sizeof(u16), 1286 .maxlen = sizeof(u16) }, 1287 [OVS_CT_ATTR_MARK] = { .minlen = sizeof(struct md_mark), 1288 .maxlen = sizeof(struct md_mark) }, 1289 [OVS_CT_ATTR_LABELS] = { .minlen = sizeof(struct md_labels), 1290 .maxlen = sizeof(struct md_labels) }, 1291 [OVS_CT_ATTR_HELPER] = { .minlen = 1, 1292 .maxlen = NF_CT_HELPER_NAME_LEN }, 1293 #ifdef CONFIG_NF_NAT_NEEDED 1294 /* NAT length is checked when parsing the nested attributes. */ 1295 [OVS_CT_ATTR_NAT] = { .minlen = 0, .maxlen = INT_MAX }, 1296 #endif 1297 [OVS_CT_ATTR_EVENTMASK] = { .minlen = sizeof(u32), 1298 .maxlen = sizeof(u32) }, 1299 }; 1300 1301 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info, 1302 const char **helper, bool log) 1303 { 1304 struct nlattr *a; 1305 int rem; 1306 1307 nla_for_each_nested(a, attr, rem) { 1308 int type = nla_type(a); 1309 int maxlen; 1310 int minlen; 1311 1312 if (type > OVS_CT_ATTR_MAX) { 1313 OVS_NLERR(log, 1314 "Unknown conntrack attr (type=%d, max=%d)", 1315 type, OVS_CT_ATTR_MAX); 1316 return -EINVAL; 1317 } 1318 1319 maxlen = ovs_ct_attr_lens[type].maxlen; 1320 minlen = ovs_ct_attr_lens[type].minlen; 1321 if (nla_len(a) < minlen || nla_len(a) > maxlen) { 1322 OVS_NLERR(log, 1323 "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)", 1324 type, nla_len(a), maxlen); 1325 return -EINVAL; 1326 } 1327 1328 switch (type) { 1329 case OVS_CT_ATTR_FORCE_COMMIT: 1330 info->force = true; 1331 /* fall through. */ 1332 case OVS_CT_ATTR_COMMIT: 1333 info->commit = true; 1334 break; 1335 #ifdef CONFIG_NF_CONNTRACK_ZONES 1336 case OVS_CT_ATTR_ZONE: 1337 info->zone.id = nla_get_u16(a); 1338 break; 1339 #endif 1340 #ifdef CONFIG_NF_CONNTRACK_MARK 1341 case OVS_CT_ATTR_MARK: { 1342 struct md_mark *mark = nla_data(a); 1343 1344 if (!mark->mask) { 1345 OVS_NLERR(log, "ct_mark mask cannot be 0"); 1346 return -EINVAL; 1347 } 1348 info->mark = *mark; 1349 break; 1350 } 1351 #endif 1352 #ifdef CONFIG_NF_CONNTRACK_LABELS 1353 case OVS_CT_ATTR_LABELS: { 1354 struct md_labels *labels = nla_data(a); 1355 1356 if (!labels_nonzero(&labels->mask)) { 1357 OVS_NLERR(log, "ct_labels mask cannot be 0"); 1358 return -EINVAL; 1359 } 1360 info->labels = *labels; 1361 break; 1362 } 1363 #endif 1364 case OVS_CT_ATTR_HELPER: 1365 *helper = nla_data(a); 1366 if (!memchr(*helper, '\0', nla_len(a))) { 1367 OVS_NLERR(log, "Invalid conntrack helper"); 1368 return -EINVAL; 1369 } 1370 break; 1371 #ifdef CONFIG_NF_NAT_NEEDED 1372 case OVS_CT_ATTR_NAT: { 1373 int err = parse_nat(a, info, log); 1374 1375 if (err) 1376 return err; 1377 break; 1378 } 1379 #endif 1380 case OVS_CT_ATTR_EVENTMASK: 1381 info->have_eventmask = true; 1382 info->eventmask = nla_get_u32(a); 1383 break; 1384 1385 default: 1386 OVS_NLERR(log, "Unknown conntrack attr (%d)", 1387 type); 1388 return -EINVAL; 1389 } 1390 } 1391 1392 #ifdef CONFIG_NF_CONNTRACK_MARK 1393 if (!info->commit && info->mark.mask) { 1394 OVS_NLERR(log, 1395 "Setting conntrack mark requires 'commit' flag."); 1396 return -EINVAL; 1397 } 1398 #endif 1399 #ifdef CONFIG_NF_CONNTRACK_LABELS 1400 if (!info->commit && labels_nonzero(&info->labels.mask)) { 1401 OVS_NLERR(log, 1402 "Setting conntrack labels requires 'commit' flag."); 1403 return -EINVAL; 1404 } 1405 #endif 1406 if (rem > 0) { 1407 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem); 1408 return -EINVAL; 1409 } 1410 1411 return 0; 1412 } 1413 1414 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr) 1415 { 1416 if (attr == OVS_KEY_ATTR_CT_STATE) 1417 return true; 1418 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) && 1419 attr == OVS_KEY_ATTR_CT_ZONE) 1420 return true; 1421 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && 1422 attr == OVS_KEY_ATTR_CT_MARK) 1423 return true; 1424 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) && 1425 attr == OVS_KEY_ATTR_CT_LABELS) { 1426 struct ovs_net *ovs_net = net_generic(net, ovs_net_id); 1427 1428 return ovs_net->xt_label; 1429 } 1430 1431 return false; 1432 } 1433 1434 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr, 1435 const struct sw_flow_key *key, 1436 struct sw_flow_actions **sfa, bool log) 1437 { 1438 struct ovs_conntrack_info ct_info; 1439 const char *helper = NULL; 1440 u16 family; 1441 int err; 1442 1443 family = key_to_nfproto(key); 1444 if (family == NFPROTO_UNSPEC) { 1445 OVS_NLERR(log, "ct family unspecified"); 1446 return -EINVAL; 1447 } 1448 1449 memset(&ct_info, 0, sizeof(ct_info)); 1450 ct_info.family = family; 1451 1452 nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID, 1453 NF_CT_DEFAULT_ZONE_DIR, 0); 1454 1455 err = parse_ct(attr, &ct_info, &helper, log); 1456 if (err) 1457 return err; 1458 1459 /* Set up template for tracking connections in specific zones. */ 1460 ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL); 1461 if (!ct_info.ct) { 1462 OVS_NLERR(log, "Failed to allocate conntrack template"); 1463 return -ENOMEM; 1464 } 1465 1466 __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status); 1467 nf_conntrack_get(&ct_info.ct->ct_general); 1468 1469 if (helper) { 1470 err = ovs_ct_add_helper(&ct_info, helper, key, log); 1471 if (err) 1472 goto err_free_ct; 1473 } 1474 1475 err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info, 1476 sizeof(ct_info), log); 1477 if (err) 1478 goto err_free_ct; 1479 1480 return 0; 1481 err_free_ct: 1482 __ovs_ct_free_action(&ct_info); 1483 return err; 1484 } 1485 1486 #ifdef CONFIG_NF_NAT_NEEDED 1487 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info, 1488 struct sk_buff *skb) 1489 { 1490 struct nlattr *start; 1491 1492 start = nla_nest_start(skb, OVS_CT_ATTR_NAT); 1493 if (!start) 1494 return false; 1495 1496 if (info->nat & OVS_CT_SRC_NAT) { 1497 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC)) 1498 return false; 1499 } else if (info->nat & OVS_CT_DST_NAT) { 1500 if (nla_put_flag(skb, OVS_NAT_ATTR_DST)) 1501 return false; 1502 } else { 1503 goto out; 1504 } 1505 1506 if (info->range.flags & NF_NAT_RANGE_MAP_IPS) { 1507 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) && 1508 info->family == NFPROTO_IPV4) { 1509 if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN, 1510 info->range.min_addr.ip) || 1511 (info->range.max_addr.ip 1512 != info->range.min_addr.ip && 1513 (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX, 1514 info->range.max_addr.ip)))) 1515 return false; 1516 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) && 1517 info->family == NFPROTO_IPV6) { 1518 if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN, 1519 &info->range.min_addr.in6) || 1520 (memcmp(&info->range.max_addr.in6, 1521 &info->range.min_addr.in6, 1522 sizeof(info->range.max_addr.in6)) && 1523 (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX, 1524 &info->range.max_addr.in6)))) 1525 return false; 1526 } else { 1527 return false; 1528 } 1529 } 1530 if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED && 1531 (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN, 1532 ntohs(info->range.min_proto.all)) || 1533 (info->range.max_proto.all != info->range.min_proto.all && 1534 nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX, 1535 ntohs(info->range.max_proto.all))))) 1536 return false; 1537 1538 if (info->range.flags & NF_NAT_RANGE_PERSISTENT && 1539 nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT)) 1540 return false; 1541 if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM && 1542 nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH)) 1543 return false; 1544 if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY && 1545 nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM)) 1546 return false; 1547 out: 1548 nla_nest_end(skb, start); 1549 1550 return true; 1551 } 1552 #endif 1553 1554 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info, 1555 struct sk_buff *skb) 1556 { 1557 struct nlattr *start; 1558 1559 start = nla_nest_start(skb, OVS_ACTION_ATTR_CT); 1560 if (!start) 1561 return -EMSGSIZE; 1562 1563 if (ct_info->commit && nla_put_flag(skb, ct_info->force 1564 ? OVS_CT_ATTR_FORCE_COMMIT 1565 : OVS_CT_ATTR_COMMIT)) 1566 return -EMSGSIZE; 1567 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) && 1568 nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id)) 1569 return -EMSGSIZE; 1570 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask && 1571 nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark), 1572 &ct_info->mark)) 1573 return -EMSGSIZE; 1574 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) && 1575 labels_nonzero(&ct_info->labels.mask) && 1576 nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels), 1577 &ct_info->labels)) 1578 return -EMSGSIZE; 1579 if (ct_info->helper) { 1580 if (nla_put_string(skb, OVS_CT_ATTR_HELPER, 1581 ct_info->helper->name)) 1582 return -EMSGSIZE; 1583 } 1584 if (ct_info->have_eventmask && 1585 nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask)) 1586 return -EMSGSIZE; 1587 1588 #ifdef CONFIG_NF_NAT_NEEDED 1589 if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb)) 1590 return -EMSGSIZE; 1591 #endif 1592 nla_nest_end(skb, start); 1593 1594 return 0; 1595 } 1596 1597 void ovs_ct_free_action(const struct nlattr *a) 1598 { 1599 struct ovs_conntrack_info *ct_info = nla_data(a); 1600 1601 __ovs_ct_free_action(ct_info); 1602 } 1603 1604 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info) 1605 { 1606 if (ct_info->helper) 1607 nf_conntrack_helper_put(ct_info->helper); 1608 if (ct_info->ct) 1609 nf_ct_tmpl_free(ct_info->ct); 1610 } 1611 1612 void ovs_ct_init(struct net *net) 1613 { 1614 unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE; 1615 struct ovs_net *ovs_net = net_generic(net, ovs_net_id); 1616 1617 if (nf_connlabels_get(net, n_bits - 1)) { 1618 ovs_net->xt_label = false; 1619 OVS_NLERR(true, "Failed to set connlabel length"); 1620 } else { 1621 ovs_net->xt_label = true; 1622 } 1623 } 1624 1625 void ovs_ct_exit(struct net *net) 1626 { 1627 struct ovs_net *ovs_net = net_generic(net, ovs_net_id); 1628 1629 if (ovs_net->xt_label) 1630 nf_connlabels_put(net); 1631 } 1632