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
  38struct ovs_ct_len_tbl {
  39	int maxlen;
  40	int minlen;
  41};
  42
  43/* Metadata mark for masked write to conntrack mark */
  44struct md_mark {
  45	u32 value;
  46	u32 mask;
  47};
  48
  49/* Metadata label for masked write to conntrack label. */
  50struct md_labels {
  51	struct ovs_key_ct_labels value;
  52	struct ovs_key_ct_labels mask;
  53};
  54
  55enum 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. */
  62struct 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
  79static bool labels_nonzero(const struct ovs_key_ct_labels *labels);
  80
  81static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
  82
  83static 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. */
  96static 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
 128static 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
 142static 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
 153static 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
 167static 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 */
 211static 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 */
 252void 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
 261int 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
 309static 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
 329static 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 */
 346static 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
 387static 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. */
 410static 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 */
 471static 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
 514static struct nf_conntrack_expect *
 515ovs_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. */
 554static enum ip_conntrack_info
 555ovs_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 */
 578static struct nf_conn *
 579ovs_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
 632static
 633struct 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. */
 661static 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 */
 711static 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		/* fall through */
 756	case IP_CT_NEW:
 757		/* Seen it before?  This can happen for loopback, retrans,
 758		 * or local packets.
 759		 */
 760		if (!nf_nat_initialized(ct, maniptype)) {
 761			/* Initialize according to the NAT action. */
 762			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
 763				/* Action is set up to establish a new
 764				 * mapping.
 765				 */
 766				? nf_nat_setup_info(ct, range, maniptype)
 767				: nf_nat_alloc_null_binding(ct, hooknum);
 768			if (err != NF_ACCEPT)
 769				goto push;
 770		}
 771		break;
 772
 773	case IP_CT_ESTABLISHED:
 774	case IP_CT_ESTABLISHED_REPLY:
 775		break;
 776
 777	default:
 778		err = NF_DROP;
 779		goto push;
 780	}
 781
 782	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
 783push:
 784	skb_push(skb, nh_off);
 785	skb_postpush_rcsum(skb, skb->data, nh_off);
 786
 787	return err;
 788}
 789
 790static void ovs_nat_update_key(struct sw_flow_key *key,
 791			       const struct sk_buff *skb,
 792			       enum nf_nat_manip_type maniptype)
 793{
 794	if (maniptype == NF_NAT_MANIP_SRC) {
 795		__be16 src;
 796
 797		key->ct_state |= OVS_CS_F_SRC_NAT;
 798		if (key->eth.type == htons(ETH_P_IP))
 799			key->ipv4.addr.src = ip_hdr(skb)->saddr;
 800		else if (key->eth.type == htons(ETH_P_IPV6))
 801			memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
 802			       sizeof(key->ipv6.addr.src));
 803		else
 804			return;
 805
 806		if (key->ip.proto == IPPROTO_UDP)
 807			src = udp_hdr(skb)->source;
 808		else if (key->ip.proto == IPPROTO_TCP)
 809			src = tcp_hdr(skb)->source;
 810		else if (key->ip.proto == IPPROTO_SCTP)
 811			src = sctp_hdr(skb)->source;
 812		else
 813			return;
 814
 815		key->tp.src = src;
 816	} else {
 817		__be16 dst;
 818
 819		key->ct_state |= OVS_CS_F_DST_NAT;
 820		if (key->eth.type == htons(ETH_P_IP))
 821			key->ipv4.addr.dst = ip_hdr(skb)->daddr;
 822		else if (key->eth.type == htons(ETH_P_IPV6))
 823			memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
 824			       sizeof(key->ipv6.addr.dst));
 825		else
 826			return;
 827
 828		if (key->ip.proto == IPPROTO_UDP)
 829			dst = udp_hdr(skb)->dest;
 830		else if (key->ip.proto == IPPROTO_TCP)
 831			dst = tcp_hdr(skb)->dest;
 832		else if (key->ip.proto == IPPROTO_SCTP)
 833			dst = sctp_hdr(skb)->dest;
 834		else
 835			return;
 836
 837		key->tp.dst = dst;
 838	}
 839}
 840
 841/* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
 842static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 843		      const struct ovs_conntrack_info *info,
 844		      struct sk_buff *skb, struct nf_conn *ct,
 845		      enum ip_conntrack_info ctinfo)
 846{
 847	enum nf_nat_manip_type maniptype;
 848	int err;
 849
 
 
 
 
 
 850	/* Add NAT extension if not confirmed yet. */
 851	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
 852		return NF_ACCEPT;   /* Can't NAT. */
 853
 854	/* Determine NAT type.
 855	 * Check if the NAT type can be deduced from the tracked connection.
 856	 * Make sure new expected connections (IP_CT_RELATED) are NATted only
 857	 * when committing.
 858	 */
 859	if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
 860	    ct->status & IPS_NAT_MASK &&
 861	    (ctinfo != IP_CT_RELATED || info->commit)) {
 862		/* NAT an established or related connection like before. */
 863		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
 864			/* This is the REPLY direction for a connection
 865			 * for which NAT was applied in the forward
 866			 * direction.  Do the reverse NAT.
 867			 */
 868			maniptype = ct->status & IPS_SRC_NAT
 869				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
 870		else
 871			maniptype = ct->status & IPS_SRC_NAT
 872				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
 873	} else if (info->nat & OVS_CT_SRC_NAT) {
 874		maniptype = NF_NAT_MANIP_SRC;
 875	} else if (info->nat & OVS_CT_DST_NAT) {
 876		maniptype = NF_NAT_MANIP_DST;
 877	} else {
 878		return NF_ACCEPT; /* Connection is not NATed. */
 879	}
 880	err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
 881
 882	/* Mark NAT done if successful and update the flow key. */
 883	if (err == NF_ACCEPT)
 884		ovs_nat_update_key(key, skb, maniptype);
 885
 886	return err;
 887}
 888#else /* !CONFIG_NF_NAT_NEEDED */
 889static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
 890		      const struct ovs_conntrack_info *info,
 891		      struct sk_buff *skb, struct nf_conn *ct,
 892		      enum ip_conntrack_info ctinfo)
 893{
 894	return NF_ACCEPT;
 895}
 896#endif
 897
 898/* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
 899 * not done already.  Update key with new CT state after passing the packet
 900 * through conntrack.
 901 * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
 902 * set to NULL and 0 will be returned.
 903 */
 904static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 905			   const struct ovs_conntrack_info *info,
 906			   struct sk_buff *skb)
 907{
 908	/* If we are recirculating packets to match on conntrack fields and
 909	 * committing with a separate conntrack action,  then we don't need to
 910	 * actually run the packet through conntrack twice unless it's for a
 911	 * different zone.
 912	 */
 913	bool cached = skb_nfct_cached(net, key, info, skb);
 914	enum ip_conntrack_info ctinfo;
 915	struct nf_conn *ct;
 916
 917	if (!cached) {
 918		struct nf_conn *tmpl = info->ct;
 919		int err;
 920
 921		/* Associate skb with specified zone. */
 922		if (tmpl) {
 923			if (skb_nfct(skb))
 924				nf_conntrack_put(skb_nfct(skb));
 925			nf_conntrack_get(&tmpl->ct_general);
 926			nf_ct_set(skb, tmpl, IP_CT_NEW);
 
 927		}
 928
 929		err = nf_conntrack_in(net, info->family,
 930				      NF_INET_PRE_ROUTING, skb);
 
 
 
 
 931		if (err != NF_ACCEPT)
 932			return -ENOENT;
 933
 934		/* Clear CT state NAT flags to mark that we have not yet done
 935		 * NAT after the nf_conntrack_in() call.  We can actually clear
 936		 * the whole state, as it will be re-initialized below.
 937		 */
 938		key->ct_state = 0;
 939
 940		/* Update the key, but keep the NAT flags. */
 941		ovs_ct_update_key(skb, info, key, true, true);
 942	}
 943
 944	ct = nf_ct_get(skb, &ctinfo);
 945	if (ct) {
 946		/* Packets starting a new connection must be NATted before the
 947		 * helper, so that the helper knows about the NAT.  We enforce
 948		 * this by delaying both NAT and helper calls for unconfirmed
 949		 * connections until the committing CT action.  For later
 950		 * packets NAT and Helper may be called in either order.
 951		 *
 952		 * NAT will be done only if the CT action has NAT, and only
 953		 * once per packet (per zone), as guarded by the NAT bits in
 954		 * the key->ct_state.
 955		 */
 956		if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
 957		    (nf_ct_is_confirmed(ct) || info->commit) &&
 958		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
 959			return -EINVAL;
 960		}
 961
 962		/* Userspace may decide to perform a ct lookup without a helper
 963		 * specified followed by a (recirculate and) commit with one.
 964		 * Therefore, for unconfirmed connections which we will commit,
 965		 * we need to attach the helper here.
 966		 */
 967		if (!nf_ct_is_confirmed(ct) && info->commit &&
 968		    info->helper && !nfct_help(ct)) {
 969			int err = __nf_ct_try_assign_helper(ct, info->ct,
 970							    GFP_ATOMIC);
 971			if (err)
 972				return err;
 973		}
 974
 975		/* Call the helper only if:
 976		 * - nf_conntrack_in() was executed above ("!cached") for a
 977		 *   confirmed connection, or
 978		 * - When committing an unconfirmed connection.
 979		 */
 980		if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
 981		    ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
 982			return -EINVAL;
 983		}
 984	}
 985
 986	return 0;
 987}
 988
 989/* Lookup connection and read fields into key. */
 990static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
 991			 const struct ovs_conntrack_info *info,
 992			 struct sk_buff *skb)
 993{
 994	struct nf_conntrack_expect *exp;
 995
 996	/* If we pass an expected packet through nf_conntrack_in() the
 997	 * expectation is typically removed, but the packet could still be
 998	 * lost in upcall processing.  To prevent this from happening we
 999	 * perform an explicit expectation lookup.  Expected connections are
1000	 * always new, and will be passed through conntrack only when they are
1001	 * committed, as it is OK to remove the expectation at that time.
1002	 */
1003	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
1004	if (exp) {
1005		u8 state;
1006
1007		/* NOTE: New connections are NATted and Helped only when
1008		 * committed, so we are not calling into NAT here.
1009		 */
1010		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
1011		__ovs_ct_update_key(key, state, &info->zone, exp->master);
1012	} else {
1013		struct nf_conn *ct;
1014		int err;
1015
1016		err = __ovs_ct_lookup(net, key, info, skb);
1017		if (err)
1018			return err;
1019
1020		ct = (struct nf_conn *)skb_nfct(skb);
1021		if (ct)
1022			nf_ct_deliver_cached_events(ct);
1023	}
1024
1025	return 0;
1026}
1027
1028static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
1029{
1030	size_t i;
1031
1032	for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
1033		if (labels->ct_labels_32[i])
1034			return true;
1035
1036	return false;
1037}
1038
1039/* Lookup connection and confirm if unconfirmed. */
1040static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
1041			 const struct ovs_conntrack_info *info,
1042			 struct sk_buff *skb)
1043{
1044	enum ip_conntrack_info ctinfo;
1045	struct nf_conn *ct;
1046	int err;
1047
1048	err = __ovs_ct_lookup(net, key, info, skb);
1049	if (err)
1050		return err;
1051
1052	/* The connection could be invalid, in which case this is a no-op.*/
1053	ct = nf_ct_get(skb, &ctinfo);
1054	if (!ct)
1055		return 0;
1056
1057	/* Set the conntrack event mask if given.  NEW and DELETE events have
1058	 * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
1059	 * typically would receive many kinds of updates.  Setting the event
1060	 * mask allows those events to be filtered.  The set event mask will
1061	 * remain in effect for the lifetime of the connection unless changed
1062	 * by a further CT action with both the commit flag and the eventmask
1063	 * option. */
1064	if (info->have_eventmask) {
1065		struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
1066
1067		if (cache)
1068			cache->ctmask = info->eventmask;
1069	}
1070
1071	/* Apply changes before confirming the connection so that the initial
1072	 * conntrack NEW netlink event carries the values given in the CT
1073	 * action.
1074	 */
1075	if (info->mark.mask) {
1076		err = ovs_ct_set_mark(ct, key, info->mark.value,
1077				      info->mark.mask);
1078		if (err)
1079			return err;
1080	}
1081	if (!nf_ct_is_confirmed(ct)) {
1082		err = ovs_ct_init_labels(ct, key, &info->labels.value,
1083					 &info->labels.mask);
1084		if (err)
1085			return err;
1086	} else if (labels_nonzero(&info->labels.mask)) {
1087		err = ovs_ct_set_labels(ct, key, &info->labels.value,
1088					&info->labels.mask);
1089		if (err)
1090			return err;
1091	}
1092	/* This will take care of sending queued events even if the connection
1093	 * is already confirmed.
1094	 */
1095	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
1096		return -EINVAL;
1097
1098	return 0;
1099}
1100
1101/* Trim the skb to the length specified by the IP/IPv6 header,
1102 * removing any trailing lower-layer padding. This prepares the skb
1103 * for higher-layer processing that assumes skb->len excludes padding
1104 * (such as nf_ip_checksum). The caller needs to pull the skb to the
1105 * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
1106 */
1107static int ovs_skb_network_trim(struct sk_buff *skb)
1108{
1109	unsigned int len;
1110	int err;
1111
1112	switch (skb->protocol) {
1113	case htons(ETH_P_IP):
1114		len = ntohs(ip_hdr(skb)->tot_len);
1115		break;
1116	case htons(ETH_P_IPV6):
1117		len = sizeof(struct ipv6hdr)
1118			+ ntohs(ipv6_hdr(skb)->payload_len);
1119		break;
1120	default:
1121		len = skb->len;
1122	}
1123
1124	err = pskb_trim_rcsum(skb, len);
1125	if (err)
1126		kfree_skb(skb);
1127
1128	return err;
1129}
1130
1131/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
1132 * value if 'skb' is freed.
1133 */
1134int ovs_ct_execute(struct net *net, struct sk_buff *skb,
1135		   struct sw_flow_key *key,
1136		   const struct ovs_conntrack_info *info)
1137{
1138	int nh_ofs;
1139	int err;
1140
1141	/* The conntrack module expects to be working at L3. */
1142	nh_ofs = skb_network_offset(skb);
1143	skb_pull_rcsum(skb, nh_ofs);
1144
1145	err = ovs_skb_network_trim(skb);
1146	if (err)
1147		return err;
1148
1149	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
1150		err = handle_fragments(net, key, info->zone.id, skb);
1151		if (err)
1152			return err;
1153	}
1154
1155	if (info->commit)
1156		err = ovs_ct_commit(net, key, info, skb);
1157	else
1158		err = ovs_ct_lookup(net, key, info, skb);
 
 
1159
 
 
 
 
 
 
 
 
 
 
1160	skb_push(skb, nh_ofs);
1161	skb_postpush_rcsum(skb, skb->data, nh_ofs);
1162	if (err)
1163		kfree_skb(skb);
1164	return err;
1165}
1166
1167int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
1168{
1169	if (skb_nfct(skb)) {
1170		nf_conntrack_put(skb_nfct(skb));
1171		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
1172		ovs_ct_fill_key(skb, key);
1173	}
1174
1175	return 0;
1176}
1177
1178static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
1179			     const struct sw_flow_key *key, bool log)
1180{
1181	struct nf_conntrack_helper *helper;
1182	struct nf_conn_help *help;
1183
1184	helper = nf_conntrack_helper_try_module_get(name, info->family,
1185						    key->ip.proto);
1186	if (!helper) {
1187		OVS_NLERR(log, "Unknown helper \"%s\"", name);
1188		return -EINVAL;
1189	}
1190
1191	help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
1192	if (!help) {
1193		nf_conntrack_helper_put(helper);
1194		return -ENOMEM;
1195	}
1196
1197	rcu_assign_pointer(help->helper, helper);
1198	info->helper = helper;
1199	return 0;
1200}
1201
1202#ifdef CONFIG_NF_NAT_NEEDED
1203static int parse_nat(const struct nlattr *attr,
1204		     struct ovs_conntrack_info *info, bool log)
1205{
1206	struct nlattr *a;
1207	int rem;
1208	bool have_ip_max = false;
1209	bool have_proto_max = false;
1210	bool ip_vers = (info->family == NFPROTO_IPV6);
1211
1212	nla_for_each_nested(a, attr, rem) {
1213		static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
1214			[OVS_NAT_ATTR_SRC] = {0, 0},
1215			[OVS_NAT_ATTR_DST] = {0, 0},
1216			[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
1217						 sizeof(struct in6_addr)},
1218			[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
1219						 sizeof(struct in6_addr)},
1220			[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
1221			[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
1222			[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
1223			[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
1224			[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
1225		};
1226		int type = nla_type(a);
1227
1228		if (type > OVS_NAT_ATTR_MAX) {
1229			OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
 
1230				  type, OVS_NAT_ATTR_MAX);
1231			return -EINVAL;
1232		}
1233
1234		if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
1235			OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
 
1236				  type, nla_len(a),
1237				  ovs_nat_attr_lens[type][ip_vers]);
1238			return -EINVAL;
1239		}
1240
1241		switch (type) {
1242		case OVS_NAT_ATTR_SRC:
1243		case OVS_NAT_ATTR_DST:
1244			if (info->nat) {
1245				OVS_NLERR(log, "Only one type of NAT may be specified");
 
 
1246				return -ERANGE;
1247			}
1248			info->nat |= OVS_CT_NAT;
1249			info->nat |= ((type == OVS_NAT_ATTR_SRC)
1250					? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1251			break;
1252
1253		case OVS_NAT_ATTR_IP_MIN:
1254			nla_memcpy(&info->range.min_addr, a,
1255				   sizeof(info->range.min_addr));
1256			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1257			break;
1258
1259		case OVS_NAT_ATTR_IP_MAX:
1260			have_ip_max = true;
1261			nla_memcpy(&info->range.max_addr, a,
1262				   sizeof(info->range.max_addr));
1263			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1264			break;
1265
1266		case OVS_NAT_ATTR_PROTO_MIN:
1267			info->range.min_proto.all = htons(nla_get_u16(a));
1268			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1269			break;
1270
1271		case OVS_NAT_ATTR_PROTO_MAX:
1272			have_proto_max = true;
1273			info->range.max_proto.all = htons(nla_get_u16(a));
1274			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1275			break;
1276
1277		case OVS_NAT_ATTR_PERSISTENT:
1278			info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1279			break;
1280
1281		case OVS_NAT_ATTR_PROTO_HASH:
1282			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1283			break;
1284
1285		case OVS_NAT_ATTR_PROTO_RANDOM:
1286			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1287			break;
1288
1289		default:
1290			OVS_NLERR(log, "Unknown nat attribute (%d)", type);
1291			return -EINVAL;
1292		}
1293	}
1294
1295	if (rem > 0) {
1296		OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
1297		return -EINVAL;
1298	}
1299	if (!info->nat) {
1300		/* Do not allow flags if no type is given. */
1301		if (info->range.flags) {
1302			OVS_NLERR(log,
1303				  "NAT flags may be given only when NAT range (SRC or DST) is also specified."
1304				  );
1305			return -EINVAL;
1306		}
1307		info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1308	} else if (!info->commit) {
1309		OVS_NLERR(log,
1310			  "NAT attributes may be specified only when CT COMMIT flag is also specified."
1311			  );
1312		return -EINVAL;
1313	}
1314	/* Allow missing IP_MAX. */
1315	if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1316		memcpy(&info->range.max_addr, &info->range.min_addr,
1317		       sizeof(info->range.max_addr));
1318	}
1319	/* Allow missing PROTO_MAX. */
1320	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1321	    !have_proto_max) {
1322		info->range.max_proto.all = info->range.min_proto.all;
1323	}
1324	return 0;
1325}
1326#endif
1327
1328static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1329	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
1330	[OVS_CT_ATTR_FORCE_COMMIT]	= { .minlen = 0, .maxlen = 0 },
1331	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
1332				    .maxlen = sizeof(u16) },
1333	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
1334				    .maxlen = sizeof(struct md_mark) },
1335	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
1336				    .maxlen = sizeof(struct md_labels) },
1337	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
1338				    .maxlen = NF_CT_HELPER_NAME_LEN },
1339#ifdef CONFIG_NF_NAT_NEEDED
1340	/* NAT length is checked when parsing the nested attributes. */
1341	[OVS_CT_ATTR_NAT]	= { .minlen = 0, .maxlen = INT_MAX },
1342#endif
1343	[OVS_CT_ATTR_EVENTMASK]	= { .minlen = sizeof(u32),
1344				    .maxlen = sizeof(u32) },
1345};
1346
1347static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1348		    const char **helper, bool log)
1349{
1350	struct nlattr *a;
1351	int rem;
1352
1353	nla_for_each_nested(a, attr, rem) {
1354		int type = nla_type(a);
1355		int maxlen;
1356		int minlen;
1357
1358		if (type > OVS_CT_ATTR_MAX) {
1359			OVS_NLERR(log,
1360				  "Unknown conntrack attr (type=%d, max=%d)",
1361				  type, OVS_CT_ATTR_MAX);
1362			return -EINVAL;
1363		}
1364
1365		maxlen = ovs_ct_attr_lens[type].maxlen;
1366		minlen = ovs_ct_attr_lens[type].minlen;
1367		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1368			OVS_NLERR(log,
1369				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1370				  type, nla_len(a), maxlen);
1371			return -EINVAL;
1372		}
1373
1374		switch (type) {
1375		case OVS_CT_ATTR_FORCE_COMMIT:
1376			info->force = true;
1377			/* fall through. */
1378		case OVS_CT_ATTR_COMMIT:
1379			info->commit = true;
1380			break;
1381#ifdef CONFIG_NF_CONNTRACK_ZONES
1382		case OVS_CT_ATTR_ZONE:
1383			info->zone.id = nla_get_u16(a);
1384			break;
1385#endif
1386#ifdef CONFIG_NF_CONNTRACK_MARK
1387		case OVS_CT_ATTR_MARK: {
1388			struct md_mark *mark = nla_data(a);
1389
1390			if (!mark->mask) {
1391				OVS_NLERR(log, "ct_mark mask cannot be 0");
1392				return -EINVAL;
1393			}
1394			info->mark = *mark;
1395			break;
1396		}
1397#endif
1398#ifdef CONFIG_NF_CONNTRACK_LABELS
1399		case OVS_CT_ATTR_LABELS: {
1400			struct md_labels *labels = nla_data(a);
1401
1402			if (!labels_nonzero(&labels->mask)) {
1403				OVS_NLERR(log, "ct_labels mask cannot be 0");
1404				return -EINVAL;
1405			}
1406			info->labels = *labels;
1407			break;
1408		}
1409#endif
1410		case OVS_CT_ATTR_HELPER:
1411			*helper = nla_data(a);
1412			if (!memchr(*helper, '\0', nla_len(a))) {
1413				OVS_NLERR(log, "Invalid conntrack helper");
1414				return -EINVAL;
1415			}
1416			break;
1417#ifdef CONFIG_NF_NAT_NEEDED
1418		case OVS_CT_ATTR_NAT: {
1419			int err = parse_nat(a, info, log);
1420
1421			if (err)
1422				return err;
1423			break;
1424		}
1425#endif
1426		case OVS_CT_ATTR_EVENTMASK:
1427			info->have_eventmask = true;
1428			info->eventmask = nla_get_u32(a);
1429			break;
1430
1431		default:
1432			OVS_NLERR(log, "Unknown conntrack attr (%d)",
1433				  type);
1434			return -EINVAL;
1435		}
1436	}
1437
1438#ifdef CONFIG_NF_CONNTRACK_MARK
1439	if (!info->commit && info->mark.mask) {
1440		OVS_NLERR(log,
1441			  "Setting conntrack mark requires 'commit' flag.");
1442		return -EINVAL;
1443	}
1444#endif
1445#ifdef CONFIG_NF_CONNTRACK_LABELS
1446	if (!info->commit && labels_nonzero(&info->labels.mask)) {
1447		OVS_NLERR(log,
1448			  "Setting conntrack labels requires 'commit' flag.");
1449		return -EINVAL;
1450	}
1451#endif
1452	if (rem > 0) {
1453		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1454		return -EINVAL;
1455	}
1456
1457	return 0;
1458}
1459
1460bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1461{
1462	if (attr == OVS_KEY_ATTR_CT_STATE)
1463		return true;
1464	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1465	    attr == OVS_KEY_ATTR_CT_ZONE)
1466		return true;
1467	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1468	    attr == OVS_KEY_ATTR_CT_MARK)
1469		return true;
1470	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1471	    attr == OVS_KEY_ATTR_CT_LABELS) {
1472		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1473
1474		return ovs_net->xt_label;
1475	}
1476
1477	return false;
1478}
1479
1480int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1481		       const struct sw_flow_key *key,
1482		       struct sw_flow_actions **sfa,  bool log)
1483{
1484	struct ovs_conntrack_info ct_info;
1485	const char *helper = NULL;
1486	u16 family;
1487	int err;
1488
1489	family = key_to_nfproto(key);
1490	if (family == NFPROTO_UNSPEC) {
1491		OVS_NLERR(log, "ct family unspecified");
1492		return -EINVAL;
1493	}
1494
1495	memset(&ct_info, 0, sizeof(ct_info));
1496	ct_info.family = family;
1497
1498	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1499			NF_CT_DEFAULT_ZONE_DIR, 0);
1500
1501	err = parse_ct(attr, &ct_info, &helper, log);
1502	if (err)
1503		return err;
1504
1505	/* Set up template for tracking connections in specific zones. */
1506	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1507	if (!ct_info.ct) {
1508		OVS_NLERR(log, "Failed to allocate conntrack template");
1509		return -ENOMEM;
1510	}
1511
1512	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1513	nf_conntrack_get(&ct_info.ct->ct_general);
1514
1515	if (helper) {
1516		err = ovs_ct_add_helper(&ct_info, helper, key, log);
1517		if (err)
1518			goto err_free_ct;
1519	}
1520
1521	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1522				 sizeof(ct_info), log);
1523	if (err)
1524		goto err_free_ct;
1525
1526	return 0;
1527err_free_ct:
1528	__ovs_ct_free_action(&ct_info);
1529	return err;
1530}
1531
1532#ifdef CONFIG_NF_NAT_NEEDED
1533static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1534			       struct sk_buff *skb)
1535{
1536	struct nlattr *start;
1537
1538	start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1539	if (!start)
1540		return false;
1541
1542	if (info->nat & OVS_CT_SRC_NAT) {
1543		if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1544			return false;
1545	} else if (info->nat & OVS_CT_DST_NAT) {
1546		if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1547			return false;
1548	} else {
1549		goto out;
1550	}
1551
1552	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1553		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
1554		    info->family == NFPROTO_IPV4) {
1555			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1556					    info->range.min_addr.ip) ||
1557			    (info->range.max_addr.ip
1558			     != info->range.min_addr.ip &&
1559			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1560					      info->range.max_addr.ip))))
1561				return false;
1562		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
1563			   info->family == NFPROTO_IPV6) {
1564			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1565					     &info->range.min_addr.in6) ||
1566			    (memcmp(&info->range.max_addr.in6,
1567				    &info->range.min_addr.in6,
1568				    sizeof(info->range.max_addr.in6)) &&
1569			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1570					       &info->range.max_addr.in6))))
1571				return false;
1572		} else {
1573			return false;
1574		}
1575	}
1576	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1577	    (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1578			 ntohs(info->range.min_proto.all)) ||
1579	     (info->range.max_proto.all != info->range.min_proto.all &&
1580	      nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1581			  ntohs(info->range.max_proto.all)))))
1582		return false;
1583
1584	if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1585	    nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1586		return false;
1587	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1588	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1589		return false;
1590	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1591	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1592		return false;
1593out:
1594	nla_nest_end(skb, start);
1595
1596	return true;
1597}
1598#endif
1599
1600int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1601			  struct sk_buff *skb)
1602{
1603	struct nlattr *start;
1604
1605	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1606	if (!start)
1607		return -EMSGSIZE;
1608
1609	if (ct_info->commit && nla_put_flag(skb, ct_info->force
1610					    ? OVS_CT_ATTR_FORCE_COMMIT
1611					    : OVS_CT_ATTR_COMMIT))
1612		return -EMSGSIZE;
1613	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1614	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1615		return -EMSGSIZE;
1616	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1617	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1618		    &ct_info->mark))
1619		return -EMSGSIZE;
1620	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1621	    labels_nonzero(&ct_info->labels.mask) &&
1622	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1623		    &ct_info->labels))
1624		return -EMSGSIZE;
1625	if (ct_info->helper) {
1626		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1627				   ct_info->helper->name))
1628			return -EMSGSIZE;
1629	}
1630	if (ct_info->have_eventmask &&
1631	    nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
1632		return -EMSGSIZE;
1633
1634#ifdef CONFIG_NF_NAT_NEEDED
1635	if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1636		return -EMSGSIZE;
1637#endif
1638	nla_nest_end(skb, start);
1639
1640	return 0;
1641}
1642
1643void ovs_ct_free_action(const struct nlattr *a)
1644{
1645	struct ovs_conntrack_info *ct_info = nla_data(a);
1646
1647	__ovs_ct_free_action(ct_info);
1648}
1649
1650static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1651{
1652	if (ct_info->helper)
1653		nf_conntrack_helper_put(ct_info->helper);
1654	if (ct_info->ct)
1655		nf_ct_tmpl_free(ct_info->ct);
1656}
1657
1658void ovs_ct_init(struct net *net)
1659{
1660	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
1661	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1662
1663	if (nf_connlabels_get(net, n_bits - 1)) {
1664		ovs_net->xt_label = false;
1665		OVS_NLERR(true, "Failed to set connlabel length");
1666	} else {
1667		ovs_net->xt_label = true;
1668	}
1669}
1670
1671void ovs_ct_exit(struct net *net)
1672{
1673	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1674
1675	if (ovs_net->xt_label)
1676		nf_connlabels_put(net);
1677}