udp.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *	UDP over IPv6
   4 *	Linux INET6 implementation
   5 *
   6 *	Authors:
   7 *	Pedro Roque		<roque@di.fc.ul.pt>
   8 *
   9 *	Based on linux/ipv4/udp.c
  10 *
  11 *	Fixes:
  12 *	Hideaki YOSHIFUJI	:	sin6_scope_id support
  13 *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
  14 *	Alexey Kuznetsov		allow both IPv4 and IPv6 sockets to bind
  15 *					a single port at the same time.
  16 *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
  17 *      YOSHIFUJI Hideaki @USAGI:	convert /proc/net/udp6 to seq_file.
  18 */
  19
  20#include <linux/bpf-cgroup.h>
  21#include <linux/errno.h>
  22#include <linux/types.h>
  23#include <linux/socket.h>
  24#include <linux/sockios.h>
  25#include <linux/net.h>
  26#include <linux/in6.h>
  27#include <linux/netdevice.h>
  28#include <linux/if_arp.h>
  29#include <linux/ipv6.h>
  30#include <linux/icmpv6.h>
  31#include <linux/init.h>
  32#include <linux/module.h>
  33#include <linux/skbuff.h>
  34#include <linux/slab.h>
  35#include <linux/uaccess.h>
  36#include <linux/indirect_call_wrapper.h>
  37#include <trace/events/udp.h>
  38
  39#include <net/addrconf.h>
  40#include <net/ndisc.h>
  41#include <net/protocol.h>
  42#include <net/transp_v6.h>
  43#include <net/ip6_route.h>
  44#include <net/raw.h>
  45#include <net/seg6.h>
  46#include <net/tcp_states.h>
  47#include <net/ip6_checksum.h>
  48#include <net/ip6_tunnel.h>
  49#include <net/udp_tunnel.h>
  50#include <net/xfrm.h>
  51#include <net/inet_hashtables.h>
  52#include <net/inet6_hashtables.h>
  53#include <net/busy_poll.h>
  54#include <net/sock_reuseport.h>
  55#include <net/gro.h>
  56
  57#include <linux/proc_fs.h>
  58#include <linux/seq_file.h>
  59#include <trace/events/skb.h>
  60#include "udp_impl.h"
  61
  62static void udpv6_destruct_sock(struct sock *sk)
  63{
  64	udp_destruct_common(sk);
  65	inet6_sock_destruct(sk);
  66}
  67
  68int udpv6_init_sock(struct sock *sk)
  69{
  70	int res = udp_lib_init_sock(sk);
  71
  72	sk->sk_destruct = udpv6_destruct_sock;
  73	set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
  74	return res;
  75}
  76
  77INDIRECT_CALLABLE_SCOPE
  78u32 udp6_ehashfn(const struct net *net,
  79		 const struct in6_addr *laddr,
  80		 const u16 lport,
  81		 const struct in6_addr *faddr,
  82		 const __be16 fport)
  83{
  84	u32 lhash, fhash;
  85
  86	net_get_random_once(&udp6_ehash_secret,
  87			    sizeof(udp6_ehash_secret));
  88	net_get_random_once(&udp_ipv6_hash_secret,
  89			    sizeof(udp_ipv6_hash_secret));
  90
  91	lhash = (__force u32)laddr->s6_addr32[3];
  92	fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
  93
  94	return __inet6_ehashfn(lhash, lport, fhash, fport,
  95			       udp6_ehash_secret + net_hash_mix(net));
  96}
  97
  98int udp_v6_get_port(struct sock *sk, unsigned short snum)
  99{
 100	unsigned int hash2_nulladdr =
 101		ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
 102	unsigned int hash2_partial =
 103		ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
 104
 105	/* precompute partial secondary hash */
 106	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
 107	return udp_lib_get_port(sk, snum, hash2_nulladdr);
 108}
 109
 110void udp_v6_rehash(struct sock *sk)
 111{
 112	u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
 113					  &sk->sk_v6_rcv_saddr,
 114					  inet_sk(sk)->inet_num);
 115	u16 new_hash4;
 116
 117	if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) {
 118		new_hash4 = udp_ehashfn(sock_net(sk),
 119					sk->sk_rcv_saddr, sk->sk_num,
 120					sk->sk_daddr, sk->sk_dport);
 121	} else {
 122		new_hash4 = udp6_ehashfn(sock_net(sk),
 123					 &sk->sk_v6_rcv_saddr, sk->sk_num,
 124					 &sk->sk_v6_daddr, sk->sk_dport);
 125	}
 126
 127	udp_lib_rehash(sk, new_hash, new_hash4);
 128}
 129
 130static int compute_score(struct sock *sk, const struct net *net,
 131			 const struct in6_addr *saddr, __be16 sport,
 132			 const struct in6_addr *daddr, unsigned short hnum,
 133			 int dif, int sdif)
 134{
 135	int bound_dev_if, score;
 136	struct inet_sock *inet;
 137	bool dev_match;
 138
 139	if (!net_eq(sock_net(sk), net) ||
 140	    udp_sk(sk)->udp_port_hash != hnum ||
 141	    sk->sk_family != PF_INET6)
 142		return -1;
 143
 144	if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 145		return -1;
 146
 147	score = 0;
 148	inet = inet_sk(sk);
 149
 150	if (inet->inet_dport) {
 151		if (inet->inet_dport != sport)
 152			return -1;
 153		score++;
 154	}
 155
 156	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 157		if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 158			return -1;
 159		score++;
 160	}
 161
 162	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
 163	dev_match = udp_sk_bound_dev_eq(net, bound_dev_if, dif, sdif);
 164	if (!dev_match)
 165		return -1;
 166	if (bound_dev_if)
 167		score++;
 168
 169	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
 170		score++;
 171
 172	return score;
 173}
 174
 175/**
 176 * udp6_lib_lookup1() - Simplified lookup using primary hash (destination port)
 177 * @net:	Network namespace
 178 * @saddr:	Source address, network order
 179 * @sport:	Source port, network order
 180 * @daddr:	Destination address, network order
 181 * @hnum:	Destination port, host order
 182 * @dif:	Destination interface index
 183 * @sdif:	Destination bridge port index, if relevant
 184 * @udptable:	Set of UDP hash tables
 185 *
 186 * Simplified lookup to be used as fallback if no sockets are found due to a
 187 * potential race between (receive) address change, and lookup happening before
 188 * the rehash operation. This function ignores SO_REUSEPORT groups while scoring
 189 * result sockets, because if we have one, we don't need the fallback at all.
 190 *
 191 * Called under rcu_read_lock().
 192 *
 193 * Return: socket with highest matching score if any, NULL if none
 194 */
 195static struct sock *udp6_lib_lookup1(const struct net *net,
 196				     const struct in6_addr *saddr, __be16 sport,
 197				     const struct in6_addr *daddr,
 198				     unsigned int hnum, int dif, int sdif,
 199				     const struct udp_table *udptable)
 200{
 201	unsigned int slot = udp_hashfn(net, hnum, udptable->mask);
 202	struct udp_hslot *hslot = &udptable->hash[slot];
 203	struct sock *sk, *result = NULL;
 204	int score, badness = 0;
 205
 206	sk_for_each_rcu(sk, &hslot->head) {
 207		score = compute_score(sk, net,
 208				      saddr, sport, daddr, hnum, dif, sdif);
 209		if (score > badness) {
 210			result = sk;
 211			badness = score;
 212		}
 213	}
 214
 215	return result;
 216}
 217
 218/* called with rcu_read_lock() */
 219static struct sock *udp6_lib_lookup2(const struct net *net,
 220		const struct in6_addr *saddr, __be16 sport,
 221		const struct in6_addr *daddr, unsigned int hnum,
 222		int dif, int sdif, struct udp_hslot *hslot2,
 223		struct sk_buff *skb)
 224{
 225	struct sock *sk, *result;
 226	int score, badness;
 227	bool need_rescore;
 228
 229	result = NULL;
 230	badness = -1;
 231	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
 232		need_rescore = false;
 233rescore:
 234		score = compute_score(need_rescore ? result : sk, net, saddr,
 235				      sport, daddr, hnum, dif, sdif);
 236		if (score > badness) {
 237			badness = score;
 238
 239			if (need_rescore)
 240				continue;
 241
 242			if (sk->sk_state == TCP_ESTABLISHED) {
 243				result = sk;
 244				continue;
 245			}
 246
 247			result = inet6_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
 248							saddr, sport, daddr, hnum, udp6_ehashfn);
 249			if (!result) {
 250				result = sk;
 251				continue;
 252			}
 253
 254			/* Fall back to scoring if group has connections */
 255			if (!reuseport_has_conns(sk))
 256				return result;
 257
 258			/* Reuseport logic returned an error, keep original score. */
 259			if (IS_ERR(result))
 260				continue;
 261
 262			/* compute_score is too long of a function to be
 263			 * inlined, and calling it again here yields
 264			 * measurable overhead for some
 265			 * workloads. Work around it by jumping
 266			 * backwards to rescore 'result'.
 267			 */
 268			need_rescore = true;
 269			goto rescore;
 270		}
 271	}
 272	return result;
 273}
 274
 275#if IS_ENABLED(CONFIG_BASE_SMALL)
 276static struct sock *udp6_lib_lookup4(const struct net *net,
 277				     const struct in6_addr *saddr, __be16 sport,
 278				     const struct in6_addr *daddr,
 279				     unsigned int hnum, int dif, int sdif,
 280				     struct udp_table *udptable)
 281{
 282	return NULL;
 283}
 284
 285static void udp6_hash4(struct sock *sk)
 286{
 287}
 288#else /* !CONFIG_BASE_SMALL */
 289static struct sock *udp6_lib_lookup4(const struct net *net,
 290				     const struct in6_addr *saddr, __be16 sport,
 291				     const struct in6_addr *daddr,
 292				     unsigned int hnum, int dif, int sdif,
 293				     struct udp_table *udptable)
 294{
 295	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
 296	const struct hlist_nulls_node *node;
 297	struct udp_hslot *hslot4;
 298	unsigned int hash4, slot;
 299	struct udp_sock *up;
 300	struct sock *sk;
 301
 302	hash4 = udp6_ehashfn(net, daddr, hnum, saddr, sport);
 303	slot = hash4 & udptable->mask;
 304	hslot4 = &udptable->hash4[slot];
 305
 306begin:
 307	udp_lrpa_for_each_entry_rcu(up, node, &hslot4->nulls_head) {
 308		sk = (struct sock *)up;
 309		if (inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
 310			return sk;
 311	}
 312
 313	/* if the nulls value we got at the end of this lookup is not the
 314	 * expected one, we must restart lookup. We probably met an item that
 315	 * was moved to another chain due to rehash.
 316	 */
 317	if (get_nulls_value(node) != slot)
 318		goto begin;
 319
 320	return NULL;
 321}
 322
 323static void udp6_hash4(struct sock *sk)
 324{
 325	struct net *net = sock_net(sk);
 326	unsigned int hash;
 327
 328	if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) {
 329		udp4_hash4(sk);
 330		return;
 331	}
 332
 333	if (sk_unhashed(sk) || ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 334		return;
 335
 336	hash = udp6_ehashfn(net, &sk->sk_v6_rcv_saddr, sk->sk_num,
 337			    &sk->sk_v6_daddr, sk->sk_dport);
 338
 339	udp_lib_hash4(sk, hash);
 340}
 341#endif /* CONFIG_BASE_SMALL */
 342
 343/* rcu_read_lock() must be held */
 344struct sock *__udp6_lib_lookup(const struct net *net,
 345			       const struct in6_addr *saddr, __be16 sport,
 346			       const struct in6_addr *daddr, __be16 dport,
 347			       int dif, int sdif, struct udp_table *udptable,
 348			       struct sk_buff *skb)
 349{
 350	unsigned short hnum = ntohs(dport);
 351	struct udp_hslot *hslot2;
 352	struct sock *result, *sk;
 353	unsigned int hash2;
 354
 355	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
 356	hslot2 = udp_hashslot2(udptable, hash2);
 357
 358	if (udp_has_hash4(hslot2)) {
 359		result = udp6_lib_lookup4(net, saddr, sport, daddr, hnum,
 360					  dif, sdif, udptable);
 361		if (result) /* udp6_lib_lookup4 return sk or NULL */
 362			return result;
 363	}
 364
 365	/* Lookup connected or non-wildcard sockets */
 366	result = udp6_lib_lookup2(net, saddr, sport,
 367				  daddr, hnum, dif, sdif,
 368				  hslot2, skb);
 369	if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
 370		goto done;
 371
 372	/* Lookup redirect from BPF */
 373	if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
 374	    udptable == net->ipv4.udp_table) {
 375		sk = inet6_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, sizeof(struct udphdr),
 376						saddr, sport, daddr, hnum, dif,
 377						udp6_ehashfn);
 378		if (sk) {
 379			result = sk;
 380			goto done;
 381		}
 382	}
 383
 384	/* Got non-wildcard socket or error on first lookup */
 385	if (result)
 386		goto done;
 387
 388	/* Lookup wildcard sockets */
 389	hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
 390	hslot2 = udp_hashslot2(udptable, hash2);
 391
 392	result = udp6_lib_lookup2(net, saddr, sport,
 393				  &in6addr_any, hnum, dif, sdif,
 394				  hslot2, skb);
 395	if (!IS_ERR_OR_NULL(result))
 396		goto done;
 397
 398	/* Cover address change/lookup/rehash race: see __udp4_lib_lookup() */
 399	result = udp6_lib_lookup1(net, saddr, sport, daddr, hnum, dif, sdif,
 400				  udptable);
 401
 402done:
 403	if (IS_ERR(result))
 404		return NULL;
 405	return result;
 406}
 407EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
 408
 409static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
 410					  __be16 sport, __be16 dport,
 411					  struct udp_table *udptable)
 412{
 413	const struct ipv6hdr *iph = ipv6_hdr(skb);
 414
 415	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
 416				 &iph->daddr, dport, inet6_iif(skb),
 417				 inet6_sdif(skb), udptable, skb);
 418}
 419
 420struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
 421				 __be16 sport, __be16 dport)
 422{
 423	const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
 424	const struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + offset);
 425	struct net *net = dev_net(skb->dev);
 426	int iif, sdif;
 427
 428	inet6_get_iif_sdif(skb, &iif, &sdif);
 429
 430	return __udp6_lib_lookup(net, &iph->saddr, sport,
 431				 &iph->daddr, dport, iif,
 432				 sdif, net->ipv4.udp_table, NULL);
 433}
 434
 435/* Must be called under rcu_read_lock().
 436 * Does increment socket refcount.
 437 */
 438#if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
 439struct sock *udp6_lib_lookup(const struct net *net, const struct in6_addr *saddr, __be16 sport,
 440			     const struct in6_addr *daddr, __be16 dport, int dif)
 441{
 442	struct sock *sk;
 443
 444	sk =  __udp6_lib_lookup(net, saddr, sport, daddr, dport,
 445				dif, 0, net->ipv4.udp_table, NULL);
 446	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
 447		sk = NULL;
 448	return sk;
 449}
 450EXPORT_SYMBOL_GPL(udp6_lib_lookup);
 451#endif
 452
 453/* do not use the scratch area len for jumbogram: their length exceeds the
 454 * scratch area space; note that the IP6CB flags is still in the first
 455 * cacheline, so checking for jumbograms is cheap
 456 */
 457static int udp6_skb_len(struct sk_buff *skb)
 458{
 459	return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
 460}
 461
 462/*
 463 *	This should be easy, if there is something there we
 464 *	return it, otherwise we block.
 465 */
 466
 467int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 468		  int flags, int *addr_len)
 469{
 470	struct ipv6_pinfo *np = inet6_sk(sk);
 471	struct inet_sock *inet = inet_sk(sk);
 472	struct sk_buff *skb;
 473	unsigned int ulen, copied;
 474	int off, err, peeking = flags & MSG_PEEK;
 475	int is_udplite = IS_UDPLITE(sk);
 476	struct udp_mib __percpu *mib;
 477	bool checksum_valid = false;
 478	int is_udp4;
 479
 480	if (flags & MSG_ERRQUEUE)
 481		return ipv6_recv_error(sk, msg, len, addr_len);
 482
 483	if (np->rxopt.bits.rxpmtu && READ_ONCE(np->rxpmtu))
 484		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
 485
 486try_again:
 487	off = sk_peek_offset(sk, flags);
 488	skb = __skb_recv_udp(sk, flags, &off, &err);
 489	if (!skb)
 490		return err;
 491
 492	ulen = udp6_skb_len(skb);
 493	copied = len;
 494	if (copied > ulen - off)
 495		copied = ulen - off;
 496	else if (copied < ulen)
 497		msg->msg_flags |= MSG_TRUNC;
 498
 499	is_udp4 = (skb->protocol == htons(ETH_P_IP));
 500	mib = __UDPX_MIB(sk, is_udp4);
 501
 502	/*
 503	 * If checksum is needed at all, try to do it while copying the
 504	 * data.  If the data is truncated, or if we only want a partial
 505	 * coverage checksum (UDP-Lite), do it before the copy.
 506	 */
 507
 508	if (copied < ulen || peeking ||
 509	    (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
 510		checksum_valid = udp_skb_csum_unnecessary(skb) ||
 511				!__udp_lib_checksum_complete(skb);
 512		if (!checksum_valid)
 513			goto csum_copy_err;
 514	}
 515
 516	if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
 517		if (udp_skb_is_linear(skb))
 518			err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
 519		else
 520			err = skb_copy_datagram_msg(skb, off, msg, copied);
 521	} else {
 522		err = skb_copy_and_csum_datagram_msg(skb, off, msg);
 523		if (err == -EINVAL)
 524			goto csum_copy_err;
 525	}
 526	if (unlikely(err)) {
 527		if (!peeking) {
 528			udp_drops_inc(sk);
 529			SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
 530		}
 531		kfree_skb(skb);
 532		return err;
 533	}
 534	if (!peeking)
 535		SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
 536
 537	sock_recv_cmsgs(msg, sk, skb);
 538
 539	/* Copy the address. */
 540	if (msg->msg_name) {
 541		DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 542		sin6->sin6_family = AF_INET6;
 543		sin6->sin6_port = udp_hdr(skb)->source;
 544		sin6->sin6_flowinfo = 0;
 545
 546		if (is_udp4) {
 547			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 548					       &sin6->sin6_addr);
 549			sin6->sin6_scope_id = 0;
 550		} else {
 551			sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 552			sin6->sin6_scope_id =
 553				ipv6_iface_scope_id(&sin6->sin6_addr,
 554						    inet6_iif(skb));
 555		}
 556		*addr_len = sizeof(*sin6);
 557
 558		BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
 559						      (struct sockaddr *)sin6,
 560						      addr_len);
 561	}
 562
 563	if (udp_test_bit(GRO_ENABLED, sk))
 564		udp_cmsg_recv(msg, sk, skb);
 565
 566	if (np->rxopt.all)
 567		ip6_datagram_recv_common_ctl(sk, msg, skb);
 568
 569	if (is_udp4) {
 570		if (inet_cmsg_flags(inet))
 571			ip_cmsg_recv_offset(msg, sk, skb,
 572					    sizeof(struct udphdr), off);
 573	} else {
 574		if (np->rxopt.all)
 575			ip6_datagram_recv_specific_ctl(sk, msg, skb);
 576	}
 577
 578	err = copied;
 579	if (flags & MSG_TRUNC)
 580		err = ulen;
 581
 582	skb_consume_udp(sk, skb, peeking ? -err : err);
 583	return err;
 584
 585csum_copy_err:
 586	if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
 587				 udp_skb_destructor)) {
 588		SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
 589		SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
 590	}
 591	kfree_skb_reason(skb, SKB_DROP_REASON_UDP_CSUM);
 592
 593	/* starting over for a new packet, but check if we need to yield */
 594	cond_resched();
 595	msg->msg_flags &= ~MSG_TRUNC;
 596	goto try_again;
 597}
 598
 599DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
 600void udpv6_encap_enable(void)
 601{
 602	static_branch_inc(&udpv6_encap_needed_key);
 603}
 604EXPORT_SYMBOL(udpv6_encap_enable);
 605
 606/* Handler for tunnels with arbitrary destination ports: no socket lookup, go
 607 * through error handlers in encapsulations looking for a match.
 608 */
 609static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
 610				      struct inet6_skb_parm *opt,
 611				      u8 type, u8 code, int offset, __be32 info)
 612{
 613	int i;
 614
 615	for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
 616		int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
 617			       u8 type, u8 code, int offset, __be32 info);
 618		const struct ip6_tnl_encap_ops *encap;
 619
 620		encap = rcu_dereference(ip6tun_encaps[i]);
 621		if (!encap)
 622			continue;
 623		handler = encap->err_handler;
 624		if (handler && !handler(skb, opt, type, code, offset, info))
 625			return 0;
 626	}
 627
 628	return -ENOENT;
 629}
 630
 631/* Try to match ICMP errors to UDP tunnels by looking up a socket without
 632 * reversing source and destination port: this will match tunnels that force the
 633 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
 634 * lwtunnels might actually break this assumption by being configured with
 635 * different destination ports on endpoints, in this case we won't be able to
 636 * trace ICMP messages back to them.
 637 *
 638 * If this doesn't match any socket, probe tunnels with arbitrary destination
 639 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
 640 * we've sent packets to won't necessarily match the local destination port.
 641 *
 642 * Then ask the tunnel implementation to match the error against a valid
 643 * association.
 644 *
 645 * Return an error if we can't find a match, the socket if we need further
 646 * processing, zero otherwise.
 647 */
 648static struct sock *__udp6_lib_err_encap(struct net *net,
 649					 const struct ipv6hdr *hdr, int offset,
 650					 struct udphdr *uh,
 651					 struct udp_table *udptable,
 652					 struct sock *sk,
 653					 struct sk_buff *skb,
 654					 struct inet6_skb_parm *opt,
 655					 u8 type, u8 code, __be32 info)
 656{
 657	int (*lookup)(struct sock *sk, struct sk_buff *skb);
 658	int network_offset, transport_offset;
 659	struct udp_sock *up;
 660
 661	network_offset = skb_network_offset(skb);
 662	transport_offset = skb_transport_offset(skb);
 663
 664	/* Network header needs to point to the outer IPv6 header inside ICMP */
 665	skb_reset_network_header(skb);
 666
 667	/* Transport header needs to point to the UDP header */
 668	skb_set_transport_header(skb, offset);
 669
 670	if (sk) {
 671		up = udp_sk(sk);
 672
 673		lookup = READ_ONCE(up->encap_err_lookup);
 674		if (lookup && lookup(sk, skb))
 675			sk = NULL;
 676
 677		goto out;
 678	}
 679
 680	sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
 681			       &hdr->saddr, uh->dest,
 682			       inet6_iif(skb), 0, udptable, skb);
 683	if (sk) {
 684		up = udp_sk(sk);
 685
 686		lookup = READ_ONCE(up->encap_err_lookup);
 687		if (!lookup || lookup(sk, skb))
 688			sk = NULL;
 689	}
 690
 691out:
 692	if (!sk) {
 693		sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
 694							offset, info));
 695	}
 696
 697	skb_set_transport_header(skb, transport_offset);
 698	skb_set_network_header(skb, network_offset);
 699
 700	return sk;
 701}
 702
 703int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 704		   u8 type, u8 code, int offset, __be32 info,
 705		   struct udp_table *udptable)
 706{
 707	struct ipv6_pinfo *np;
 708	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 709	const struct in6_addr *saddr = &hdr->saddr;
 710	const struct in6_addr *daddr = seg6_get_daddr(skb, opt) ? : &hdr->daddr;
 711	struct udphdr *uh = (struct udphdr *)(skb->data+offset);
 712	bool tunnel = false;
 713	struct sock *sk;
 714	int harderr;
 715	int err;
 716	struct net *net = dev_net(skb->dev);
 717
 718	sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
 719			       inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
 720
 721	if (!sk || READ_ONCE(udp_sk(sk)->encap_type)) {
 722		/* No socket for error: try tunnels before discarding */
 723		if (static_branch_unlikely(&udpv6_encap_needed_key)) {
 724			sk = __udp6_lib_err_encap(net, hdr, offset, uh,
 725						  udptable, sk, skb,
 726						  opt, type, code, info);
 727			if (!sk)
 728				return 0;
 729		} else
 730			sk = ERR_PTR(-ENOENT);
 731
 732		if (IS_ERR(sk)) {
 733			__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
 734					  ICMP6_MIB_INERRORS);
 735			return PTR_ERR(sk);
 736		}
 737
 738		tunnel = true;
 739	}
 740
 741	harderr = icmpv6_err_convert(type, code, &err);
 742	np = inet6_sk(sk);
 743
 744	if (type == ICMPV6_PKT_TOOBIG) {
 745		if (!ip6_sk_accept_pmtu(sk))
 746			goto out;
 747		ip6_sk_update_pmtu(skb, sk, info);
 748		if (READ_ONCE(np->pmtudisc) != IPV6_PMTUDISC_DONT)
 749			harderr = 1;
 750	}
 751	if (type == NDISC_REDIRECT) {
 752		if (tunnel) {
 753			ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
 754				     READ_ONCE(sk->sk_mark),
 755				     sk_uid(sk));
 756		} else {
 757			ip6_sk_redirect(skb, sk);
 758		}
 759		goto out;
 760	}
 761
 762	/* Tunnels don't have an application socket: don't pass errors back */
 763	if (tunnel) {
 764		if (udp_sk(sk)->encap_err_rcv)
 765			udp_sk(sk)->encap_err_rcv(sk, skb, err, uh->dest,
 766						  ntohl(info), (u8 *)(uh+1));
 767		goto out;
 768	}
 769
 770	if (!inet6_test_bit(RECVERR6, sk)) {
 771		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
 772			goto out;
 773	} else {
 774		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
 775	}
 776
 777	sk->sk_err = err;
 778	sk_error_report(sk);
 779out:
 780	return 0;
 781}
 782
 783static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 784{
 785	int rc;
 786
 787	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 788		sock_rps_save_rxhash(sk, skb);
 789		sk_mark_napi_id(sk, skb);
 790		sk_incoming_cpu_update(sk);
 791	} else {
 792		sk_mark_napi_id_once(sk, skb);
 793	}
 794
 795	rc = __udp_enqueue_schedule_skb(sk, skb);
 796	if (rc < 0) {
 797		int is_udplite = IS_UDPLITE(sk);
 798		enum skb_drop_reason drop_reason;
 799
 800		/* Note that an ENOMEM error is charged twice */
 801		if (rc == -ENOMEM) {
 802			UDP6_INC_STATS(sock_net(sk),
 803					 UDP_MIB_RCVBUFERRORS, is_udplite);
 804			drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
 805		} else {
 806			UDP6_INC_STATS(sock_net(sk),
 807				       UDP_MIB_MEMERRORS, is_udplite);
 808			drop_reason = SKB_DROP_REASON_PROTO_MEM;
 809		}
 810		UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 811		trace_udp_fail_queue_rcv_skb(rc, sk, skb);
 812		sk_skb_reason_drop(sk, skb, drop_reason);
 813		return -1;
 814	}
 815
 816	return 0;
 817}
 818
 819static __inline__ int udpv6_err(struct sk_buff *skb,
 820				struct inet6_skb_parm *opt, u8 type,
 821				u8 code, int offset, __be32 info)
 822{
 823	return __udp6_lib_err(skb, opt, type, code, offset, info,
 824			      dev_net(skb->dev)->ipv4.udp_table);
 825}
 826
 827static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 828{
 829	enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
 830	struct udp_sock *up = udp_sk(sk);
 831	int is_udplite = IS_UDPLITE(sk);
 832
 833	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
 834		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
 835		goto drop;
 836	}
 837	nf_reset_ct(skb);
 838
 839	if (static_branch_unlikely(&udpv6_encap_needed_key) &&
 840	    READ_ONCE(up->encap_type)) {
 841		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 842
 843		/*
 844		 * This is an encapsulation socket so pass the skb to
 845		 * the socket's udp_encap_rcv() hook. Otherwise, just
 846		 * fall through and pass this up the UDP socket.
 847		 * up->encap_rcv() returns the following value:
 848		 * =0 if skb was successfully passed to the encap
 849		 *    handler or was discarded by it.
 850		 * >0 if skb should be passed on to UDP.
 851		 * <0 if skb should be resubmitted as proto -N
 852		 */
 853
 854		/* if we're overly short, let UDP handle it */
 855		encap_rcv = READ_ONCE(up->encap_rcv);
 856		if (encap_rcv) {
 857			int ret;
 858
 859			/* Verify checksum before giving to encap */
 860			if (udp_lib_checksum_complete(skb))
 861				goto csum_error;
 862
 863			ret = encap_rcv(sk, skb);
 864			if (ret <= 0) {
 865				__UDP6_INC_STATS(sock_net(sk),
 866						 UDP_MIB_INDATAGRAMS,
 867						 is_udplite);
 868				return -ret;
 869			}
 870		}
 871
 872		/* FALLTHROUGH -- it's a UDP Packet */
 873	}
 874
 875	/*
 876	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
 877	 */
 878	if (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) {
 879		u16 pcrlen = READ_ONCE(up->pcrlen);
 880
 881		if (pcrlen == 0) {          /* full coverage was set  */
 882			net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
 883					    UDP_SKB_CB(skb)->cscov, skb->len);
 884			goto drop;
 885		}
 886		if (UDP_SKB_CB(skb)->cscov < pcrlen) {
 887			net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
 888					    UDP_SKB_CB(skb)->cscov, pcrlen);
 889			goto drop;
 890		}
 891	}
 892
 893	prefetch(&sk->sk_rmem_alloc);
 894	if (rcu_access_pointer(sk->sk_filter) &&
 895	    udp_lib_checksum_complete(skb))
 896		goto csum_error;
 897
 898	if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr), &drop_reason))
 899		goto drop;
 900
 901	udp_csum_pull_header(skb);
 902
 903	skb_dst_drop(skb);
 904
 905	return __udpv6_queue_rcv_skb(sk, skb);
 906
 907csum_error:
 908	drop_reason = SKB_DROP_REASON_UDP_CSUM;
 909	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 910drop:
 911	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 912	udp_drops_inc(sk);
 913	sk_skb_reason_drop(sk, skb, drop_reason);
 914	return -1;
 915}
 916
 917static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 918{
 919	struct sk_buff *next, *segs;
 920	int ret;
 921
 922	if (likely(!udp_unexpected_gso(sk, skb)))
 923		return udpv6_queue_rcv_one_skb(sk, skb);
 924
 925	__skb_push(skb, -skb_mac_offset(skb));
 926	segs = udp_rcv_segment(sk, skb, false);
 927	skb_list_walk_safe(segs, skb, next) {
 928		__skb_pull(skb, skb_transport_offset(skb));
 929
 930		udp_post_segment_fix_csum(skb);
 931		ret = udpv6_queue_rcv_one_skb(sk, skb);
 932		if (ret > 0)
 933			ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
 934						 true);
 935	}
 936	return 0;
 937}
 938
 939static bool __udp_v6_is_mcast_sock(struct net *net, const struct sock *sk,
 940				   __be16 loc_port, const struct in6_addr *loc_addr,
 941				   __be16 rmt_port, const struct in6_addr *rmt_addr,
 942				   int dif, int sdif, unsigned short hnum)
 943{
 944	const struct inet_sock *inet = inet_sk(sk);
 945
 946	if (!net_eq(sock_net(sk), net))
 947		return false;
 948
 949	if (udp_sk(sk)->udp_port_hash != hnum ||
 950	    sk->sk_family != PF_INET6 ||
 951	    (inet->inet_dport && inet->inet_dport != rmt_port) ||
 952	    (!ipv6_addr_any(&sk->sk_v6_daddr) &&
 953		    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
 954	    !udp_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif, sdif) ||
 955	    (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
 956		    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
 957		return false;
 958	if (!inet6_mc_check(sk, loc_addr, rmt_addr))
 959		return false;
 960	return true;
 961}
 962
 963static void udp6_csum_zero_error(struct sk_buff *skb)
 964{
 965	/* RFC 2460 section 8.1 says that we SHOULD log
 966	 * this error. Well, it is reasonable.
 967	 */
 968	net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
 969			    &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
 970			    &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
 971}
 972
 973/*
 974 * Note: called only from the BH handler context,
 975 * so we don't need to lock the hashes.
 976 */
 977static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 978		const struct in6_addr *saddr, const struct in6_addr *daddr,
 979		struct udp_table *udptable, int proto)
 980{
 981	struct sock *sk, *first = NULL;
 982	const struct udphdr *uh = udp_hdr(skb);
 983	unsigned short hnum = ntohs(uh->dest);
 984	struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
 985	unsigned int offset = offsetof(typeof(*sk), sk_node);
 986	unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
 987	int dif = inet6_iif(skb);
 988	int sdif = inet6_sdif(skb);
 989	struct hlist_node *node;
 990	struct sk_buff *nskb;
 991
 992	if (use_hash2) {
 993		hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
 994			    udptable->mask;
 995		hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
 996start_lookup:
 997		hslot = &udptable->hash2[hash2].hslot;
 998		offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
 999	}
1000
1001	sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
1002		if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
1003					    uh->source, saddr, dif, sdif,
1004					    hnum))
1005			continue;
1006		/* If zero checksum and no_check is not on for
1007		 * the socket then skip it.
1008		 */
1009		if (!uh->check && !udp_get_no_check6_rx(sk))
1010			continue;
1011		if (!first) {
1012			first = sk;
1013			continue;
1014		}
1015		nskb = skb_clone(skb, GFP_ATOMIC);
1016		if (unlikely(!nskb)) {
1017			udp_drops_inc(sk);
1018			__UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
1019					 IS_UDPLITE(sk));
1020			__UDP6_INC_STATS(net, UDP_MIB_INERRORS,
1021					 IS_UDPLITE(sk));
1022			continue;
1023		}
1024
1025		if (udpv6_queue_rcv_skb(sk, nskb) > 0)
1026			consume_skb(nskb);
1027	}
1028
1029	/* Also lookup *:port if we are using hash2 and haven't done so yet. */
1030	if (use_hash2 && hash2 != hash2_any) {
1031		hash2 = hash2_any;
1032		goto start_lookup;
1033	}
1034
1035	if (first) {
1036		if (udpv6_queue_rcv_skb(first, skb) > 0)
1037			consume_skb(skb);
1038	} else {
1039		kfree_skb(skb);
1040		__UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
1041				 proto == IPPROTO_UDPLITE);
1042	}
1043	return 0;
1044}
1045
1046static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
1047{
1048	if (udp_sk_rx_dst_set(sk, dst))
1049		sk->sk_rx_dst_cookie = rt6_get_cookie(dst_rt6_info(dst));
1050}
1051
1052/* wrapper for udp_queue_rcv_skb taking care of csum conversion and
1053 * return code conversion for ip layer consumption
1054 */
1055static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
1056				struct udphdr *uh)
1057{
1058	int ret;
1059
1060	if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
1061		skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
1062
1063	ret = udpv6_queue_rcv_skb(sk, skb);
1064
1065	/* a return value > 0 means to resubmit the input */
1066	if (ret > 0)
1067		return ret;
1068	return 0;
1069}
1070
1071int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1072		   int proto)
1073{
1074	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
1075	const struct in6_addr *saddr, *daddr;
1076	struct net *net = dev_net(skb->dev);
1077	struct sock *sk = NULL;
1078	struct udphdr *uh;
1079	bool refcounted;
1080	u32 ulen = 0;
1081
1082	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1083		goto discard;
1084
1085	saddr = &ipv6_hdr(skb)->saddr;
1086	daddr = &ipv6_hdr(skb)->daddr;
1087	uh = udp_hdr(skb);
1088
1089	ulen = ntohs(uh->len);
1090	if (ulen > skb->len)
1091		goto short_packet;
1092
1093	if (proto == IPPROTO_UDP) {
1094		/* UDP validates ulen. */
1095
1096		/* Check for jumbo payload */
1097		if (ulen == 0)
1098			ulen = skb->len;
1099
1100		if (ulen < sizeof(*uh))
1101			goto short_packet;
1102
1103		if (ulen < skb->len) {
1104			if (pskb_trim_rcsum(skb, ulen))
1105				goto short_packet;
1106			saddr = &ipv6_hdr(skb)->saddr;
1107			daddr = &ipv6_hdr(skb)->daddr;
1108			uh = udp_hdr(skb);
1109		}
1110	}
1111
1112	if (udp6_csum_init(skb, uh, proto))
1113		goto csum_error;
1114
1115	/* Check if the socket is already available, e.g. due to early demux */
1116	sk = inet6_steal_sock(net, skb, sizeof(struct udphdr), saddr, uh->source, daddr, uh->dest,
1117			      &refcounted, udp6_ehashfn);
1118	if (IS_ERR(sk))
1119		goto no_sk;
1120
1121	if (sk) {
1122		struct dst_entry *dst = skb_dst(skb);
1123		int ret;
1124
1125		if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
1126			udp6_sk_rx_dst_set(sk, dst);
1127
1128		if (!uh->check && !udp_get_no_check6_rx(sk)) {
1129			if (refcounted)
1130				sock_put(sk);
1131			goto report_csum_error;
1132		}
1133
1134		ret = udp6_unicast_rcv_skb(sk, skb, uh);
1135		if (refcounted)
1136			sock_put(sk);
1137		return ret;
1138	}
1139
1140	/*
1141	 *	Multicast receive code
1142	 */
1143	if (ipv6_addr_is_multicast(daddr))
1144		return __udp6_lib_mcast_deliver(net, skb,
1145				saddr, daddr, udptable, proto);
1146
1147	/* Unicast */
1148	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1149	if (sk) {
1150		if (!uh->check && !udp_get_no_check6_rx(sk))
1151			goto report_csum_error;
1152		return udp6_unicast_rcv_skb(sk, skb, uh);
1153	}
1154no_sk:
1155	reason = SKB_DROP_REASON_NO_SOCKET;
1156
1157	if (!uh->check)
1158		goto report_csum_error;
1159
1160	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1161		goto discard;
1162	nf_reset_ct(skb);
1163
1164	if (udp_lib_checksum_complete(skb))
1165		goto csum_error;
1166
1167	__UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1168	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
1169
1170	sk_skb_reason_drop(sk, skb, reason);
1171	return 0;
1172
1173short_packet:
1174	if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1175		reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1176	net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
1177			    proto == IPPROTO_UDPLITE ? "-Lite" : "",
1178			    saddr, ntohs(uh->source),
1179			    ulen, skb->len,
1180			    daddr, ntohs(uh->dest));
1181	goto discard;
1182
1183report_csum_error:
1184	udp6_csum_zero_error(skb);
1185csum_error:
1186	if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1187		reason = SKB_DROP_REASON_UDP_CSUM;
1188	__UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1189discard:
1190	__UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1191	sk_skb_reason_drop(sk, skb, reason);
1192	return 0;
1193}
1194
1195
1196static struct sock *__udp6_lib_demux_lookup(struct net *net,
1197			__be16 loc_port, const struct in6_addr *loc_addr,
1198			__be16 rmt_port, const struct in6_addr *rmt_addr,
1199			int dif, int sdif)
1200{
1201	struct udp_table *udptable = net->ipv4.udp_table;
1202	unsigned short hnum = ntohs(loc_port);
1203	struct udp_hslot *hslot2;
1204	unsigned int hash2;
1205	__portpair ports;
1206	struct sock *sk;
1207
1208	hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
1209	hslot2 = udp_hashslot2(udptable, hash2);
1210	ports = INET_COMBINED_PORTS(rmt_port, hnum);
1211
1212	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
1213		if (sk->sk_state == TCP_ESTABLISHED &&
1214		    inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif))
1215			return sk;
1216		/* Only check first socket in chain */
1217		break;
1218	}
1219	return NULL;
1220}
1221
1222void udp_v6_early_demux(struct sk_buff *skb)
1223{
1224	struct net *net = dev_net(skb->dev);
1225	const struct udphdr *uh;
1226	struct sock *sk;
1227	struct dst_entry *dst;
1228	int dif = skb->dev->ifindex;
1229	int sdif = inet6_sdif(skb);
1230
1231	if (!pskb_may_pull(skb, skb_transport_offset(skb) +
1232	    sizeof(struct udphdr)))
1233		return;
1234
1235	uh = udp_hdr(skb);
1236
1237	if (skb->pkt_type == PACKET_HOST)
1238		sk = __udp6_lib_demux_lookup(net, uh->dest,
1239					     &ipv6_hdr(skb)->daddr,
1240					     uh->source, &ipv6_hdr(skb)->saddr,
1241					     dif, sdif);
1242	else
1243		return;
1244
1245	if (!sk)
1246		return;
1247
1248	skb->sk = sk;
1249	DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk));
1250	skb->destructor = sock_pfree;
1251	dst = rcu_dereference(sk->sk_rx_dst);
1252
1253	if (dst)
1254		dst = dst_check(dst, sk->sk_rx_dst_cookie);
1255	if (dst) {
1256		/* set noref for now.
1257		 * any place which wants to hold dst has to call
1258		 * dst_hold_safe()
1259		 */
1260		skb_dst_set_noref(skb, dst);
1261	}
1262}
1263
1264INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1265{
1266	return __udp6_lib_rcv(skb, dev_net(skb->dev)->ipv4.udp_table, IPPROTO_UDP);
1267}
1268
1269/*
1270 * Throw away all pending data and cancel the corking. Socket is locked.
1271 */
1272static void udp_v6_flush_pending_frames(struct sock *sk)
1273{
1274	struct udp_sock *up = udp_sk(sk);
1275
1276	if (up->pending == AF_INET)
1277		udp_flush_pending_frames(sk);
1278	else if (up->pending) {
1279		up->len = 0;
1280		WRITE_ONCE(up->pending, 0);
1281		ip6_flush_pending_frames(sk);
1282	}
1283}
1284
1285static int udpv6_pre_connect(struct sock *sk, struct sockaddr_unsized *uaddr,
1286			     int addr_len)
1287{
1288	if (addr_len < offsetofend(struct sockaddr, sa_family))
1289		return -EINVAL;
1290	/* The following checks are replicated from __ip6_datagram_connect()
1291	 * and intended to prevent BPF program called below from accessing
1292	 * bytes that are out of the bound specified by user in addr_len.
1293	 */
1294	if (uaddr->sa_family == AF_INET) {
1295		if (ipv6_only_sock(sk))
1296			return -EAFNOSUPPORT;
1297		return udp_pre_connect(sk, uaddr, addr_len);
1298	}
1299
1300	if (addr_len < SIN6_LEN_RFC2133)
1301		return -EINVAL;
1302
1303	return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len);
1304}
1305
1306static int udpv6_connect(struct sock *sk, struct sockaddr_unsized *uaddr,
1307			 int addr_len)
1308{
1309	int res;
1310
1311	lock_sock(sk);
1312	res = __ip6_datagram_connect(sk, uaddr, addr_len);
1313	if (!res)
1314		udp6_hash4(sk);
1315	release_sock(sk);
1316	return res;
1317}
1318
1319/**
1320 *	udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
1321 *	@sk:	socket we are sending on
1322 *	@skb:	sk_buff containing the filled-in UDP header
1323 *		(checksum field must be zeroed out)
1324 *	@saddr: source address
1325 *	@daddr: destination address
1326 *	@len:	length of packet
1327 */
1328static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1329				 const struct in6_addr *saddr,
1330				 const struct in6_addr *daddr, int len)
1331{
1332	unsigned int offset;
1333	struct udphdr *uh = udp_hdr(skb);
1334	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1335	__wsum csum = 0;
1336
1337	if (!frags) {
1338		/* Only one fragment on the socket.  */
1339		skb->csum_start = skb_transport_header(skb) - skb->head;
1340		skb->csum_offset = offsetof(struct udphdr, check);
1341		uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1342	} else {
1343		/*
1344		 * HW-checksum won't work as there are two or more
1345		 * fragments on the socket so that all csums of sk_buffs
1346		 * should be together
1347		 */
1348		offset = skb_transport_offset(skb);
1349		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1350		csum = skb->csum;
1351
1352		skb->ip_summed = CHECKSUM_NONE;
1353
1354		do {
1355			csum = csum_add(csum, frags->csum);
1356		} while ((frags = frags->next));
1357
1358		uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1359					    csum);
1360		if (uh->check == 0)
1361			uh->check = CSUM_MANGLED_0;
1362	}
1363}
1364
1365/*
1366 *	Sending
1367 */
1368
1369static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1370			   struct inet_cork *cork)
1371{
1372	struct sock *sk = skb->sk;
1373	struct udphdr *uh;
1374	int err = 0;
1375	int is_udplite = IS_UDPLITE(sk);
1376	__wsum csum = 0;
1377	int offset = skb_transport_offset(skb);
1378	int len = skb->len - offset;
1379	int datalen = len - sizeof(*uh);
1380
1381	/*
1382	 * Create a UDP header
1383	 */
1384	uh = udp_hdr(skb);
1385	uh->source = fl6->fl6_sport;
1386	uh->dest = fl6->fl6_dport;
1387	uh->len = htons(len);
1388	uh->check = 0;
1389
1390	if (cork->gso_size) {
1391		const int hlen = skb_network_header_len(skb) +
1392				 sizeof(struct udphdr);
1393
1394		if (hlen + min(datalen, cork->gso_size) > cork->fragsize) {
1395			kfree_skb(skb);
1396			return -EMSGSIZE;
1397		}
1398		if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
1399			kfree_skb(skb);
1400			return -EINVAL;
1401		}
1402		if (udp_get_no_check6_tx(sk)) {
1403			kfree_skb(skb);
1404			return -EINVAL;
1405		}
1406		if (is_udplite || dst_xfrm(skb_dst(skb))) {
1407			kfree_skb(skb);
1408			return -EIO;
1409		}
1410
1411		if (datalen > cork->gso_size) {
1412			skb_shinfo(skb)->gso_size = cork->gso_size;
1413			skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1414			skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1415								 cork->gso_size);
1416
1417			/* Don't checksum the payload, skb will get segmented */
1418			goto csum_partial;
1419		}
1420	}
1421
1422	if (is_udplite)
1423		csum = udplite_csum(skb);
1424	else if (udp_get_no_check6_tx(sk)) {   /* UDP csum disabled */
1425		skb->ip_summed = CHECKSUM_NONE;
1426		goto send;
1427	} else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1428csum_partial:
1429		udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1430		goto send;
1431	} else
1432		csum = udp_csum(skb);
1433
1434	/* add protocol-dependent pseudo-header */
1435	uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1436				    len, fl6->flowi6_proto, csum);
1437	if (uh->check == 0)
1438		uh->check = CSUM_MANGLED_0;
1439
1440send:
1441	err = ip6_send_skb(skb);
1442	if (err) {
1443		if (err == -ENOBUFS && !inet6_test_bit(RECVERR6, sk)) {
1444			UDP6_INC_STATS(sock_net(sk),
1445				       UDP_MIB_SNDBUFERRORS, is_udplite);
1446			err = 0;
1447		}
1448	} else {
1449		UDP6_INC_STATS(sock_net(sk),
1450			       UDP_MIB_OUTDATAGRAMS, is_udplite);
1451	}
1452	return err;
1453}
1454
1455static int udp_v6_push_pending_frames(struct sock *sk)
1456{
1457	struct sk_buff *skb;
1458	struct udp_sock  *up = udp_sk(sk);
1459	int err = 0;
1460
1461	if (up->pending == AF_INET)
1462		return udp_push_pending_frames(sk);
1463
1464	skb = ip6_finish_skb(sk);
1465	if (!skb)
1466		goto out;
1467
1468	err = udp_v6_send_skb(skb, &inet_sk(sk)->cork.fl.u.ip6,
1469			      &inet_sk(sk)->cork.base);
1470out:
1471	up->len = 0;
1472	WRITE_ONCE(up->pending, 0);
1473	return err;
1474}
1475
1476int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1477{
1478	struct ipv6_txoptions opt_space;
1479	struct udp_sock *up = udp_sk(sk);
1480	struct inet_sock *inet = inet_sk(sk);
1481	struct ipv6_pinfo *np = inet6_sk(sk);
1482	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1483	struct in6_addr *daddr, *final_p, final;
1484	struct ipv6_txoptions *opt = NULL;
1485	struct ipv6_txoptions *opt_to_free = NULL;
1486	struct ip6_flowlabel *flowlabel = NULL;
1487	struct inet_cork_full cork;
1488	struct flowi6 *fl6 = &cork.fl.u.ip6;
1489	struct dst_entry *dst;
1490	struct ipcm6_cookie ipc6;
1491	int addr_len = msg->msg_namelen;
1492	bool connected = false;
1493	int ulen = len;
1494	int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE;
1495	int err;
1496	int is_udplite = IS_UDPLITE(sk);
1497	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1498
1499	ipcm6_init_sk(&ipc6, sk);
1500	ipc6.gso_size = READ_ONCE(up->gso_size);
1501
1502	/* destination address check */
1503	if (sin6) {
1504		if (addr_len < offsetof(struct sockaddr, sa_data))
1505			return -EINVAL;
1506
1507		switch (sin6->sin6_family) {
1508		case AF_INET6:
1509			if (addr_len < SIN6_LEN_RFC2133)
1510				return -EINVAL;
1511			daddr = &sin6->sin6_addr;
1512			if (ipv6_addr_any(daddr) &&
1513			    ipv6_addr_v4mapped(&np->saddr))
1514				ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1515						       daddr);
1516			break;
1517		case AF_INET:
1518			goto do_udp_sendmsg;
1519		case AF_UNSPEC:
1520			msg->msg_name = sin6 = NULL;
1521			msg->msg_namelen = addr_len = 0;
1522			daddr = NULL;
1523			break;
1524		default:
1525			return -EINVAL;
1526		}
1527	} else if (!READ_ONCE(up->pending)) {
1528		if (sk->sk_state != TCP_ESTABLISHED)
1529			return -EDESTADDRREQ;
1530		daddr = &sk->sk_v6_daddr;
1531	} else
1532		daddr = NULL;
1533
1534	if (daddr) {
1535		if (ipv6_addr_v4mapped(daddr)) {
1536			struct sockaddr_in sin;
1537			sin.sin_family = AF_INET;
1538			sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1539			sin.sin_addr.s_addr = daddr->s6_addr32[3];
1540			msg->msg_name = &sin;
1541			msg->msg_namelen = sizeof(sin);
1542do_udp_sendmsg:
1543			err = ipv6_only_sock(sk) ?
1544				-ENETUNREACH : udp_sendmsg(sk, msg, len);
1545			msg->msg_name = sin6;
1546			msg->msg_namelen = addr_len;
1547			return err;
1548		}
1549	}
1550
1551	/* Rough check on arithmetic overflow,
1552	   better check is made in ip6_append_data().
1553	   */
1554	if (len > INT_MAX - sizeof(struct udphdr))
1555		return -EMSGSIZE;
1556
1557	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1558	if (READ_ONCE(up->pending)) {
1559		if (READ_ONCE(up->pending) == AF_INET)
1560			return udp_sendmsg(sk, msg, len);
1561		/*
1562		 * There are pending frames.
1563		 * The socket lock must be held while it's corked.
1564		 */
1565		lock_sock(sk);
1566		if (likely(up->pending)) {
1567			if (unlikely(up->pending != AF_INET6)) {
1568				release_sock(sk);
1569				return -EAFNOSUPPORT;
1570			}
1571			dst = NULL;
1572			goto do_append_data;
1573		}
1574		release_sock(sk);
1575	}
1576	ulen += sizeof(struct udphdr);
1577
1578	memset(fl6, 0, sizeof(*fl6));
1579
1580	if (sin6) {
1581		if (sin6->sin6_port == 0)
1582			return -EINVAL;
1583
1584		fl6->fl6_dport = sin6->sin6_port;
1585		daddr = &sin6->sin6_addr;
1586
1587		if (inet6_test_bit(SNDFLOW, sk)) {
1588			fl6->flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1589			if (fl6->flowlabel & IPV6_FLOWLABEL_MASK) {
1590				flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
1591				if (IS_ERR(flowlabel))
1592					return -EINVAL;
1593			}
1594		}
1595
1596		/*
1597		 * Otherwise it will be difficult to maintain
1598		 * sk->sk_dst_cache.
1599		 */
1600		if (sk->sk_state == TCP_ESTABLISHED &&
1601		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1602			daddr = &sk->sk_v6_daddr;
1603
1604		if (addr_len >= sizeof(struct sockaddr_in6) &&
1605		    sin6->sin6_scope_id &&
1606		    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1607			fl6->flowi6_oif = sin6->sin6_scope_id;
1608	} else {
1609		if (sk->sk_state != TCP_ESTABLISHED)
1610			return -EDESTADDRREQ;
1611
1612		fl6->fl6_dport = inet->inet_dport;
1613		daddr = &sk->sk_v6_daddr;
1614		fl6->flowlabel = np->flow_label;
1615		connected = true;
1616	}
1617
1618	if (!fl6->flowi6_oif)
1619		fl6->flowi6_oif = READ_ONCE(sk->sk_bound_dev_if);
1620
1621	if (!fl6->flowi6_oif)
1622		fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1623
1624	fl6->flowi6_uid = sk_uid(sk);
1625
1626	if (msg->msg_controllen) {
1627		opt = &opt_space;
1628		memset(opt, 0, sizeof(struct ipv6_txoptions));
1629		opt->tot_len = sizeof(*opt);
1630		ipc6.opt = opt;
1631
1632		err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1633		if (err > 0) {
1634			err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, fl6,
1635						    &ipc6);
1636			connected = false;
1637		}
1638		if (err < 0) {
1639			fl6_sock_release(flowlabel);
1640			return err;
1641		}
1642		if ((fl6->flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1643			flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
1644			if (IS_ERR(flowlabel))
1645				return -EINVAL;
1646		}
1647		if (!(opt->opt_nflen|opt->opt_flen))
1648			opt = NULL;
1649	}
1650	if (!opt) {
1651		opt = txopt_get(np);
1652		opt_to_free = opt;
1653	}
1654	if (flowlabel)
1655		opt = fl6_merge_options(&opt_space, flowlabel, opt);
1656	opt = ipv6_fixup_options(&opt_space, opt);
1657	ipc6.opt = opt;
1658
1659	fl6->flowi6_proto = sk->sk_protocol;
1660	fl6->flowi6_mark = ipc6.sockc.mark;
1661	fl6->daddr = *daddr;
1662	if (ipv6_addr_any(&fl6->saddr) && !ipv6_addr_any(&np->saddr))
1663		fl6->saddr = np->saddr;
1664	fl6->fl6_sport = inet->inet_sport;
1665
1666	if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) {
1667		err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1668					   (struct sockaddr *)sin6,
1669					   &addr_len,
1670					   &fl6->saddr);
1671		if (err)
1672			goto out_no_dst;
1673		if (sin6) {
1674			if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1675				/* BPF program rewrote IPv6-only by IPv4-mapped
1676				 * IPv6. It's currently unsupported.
1677				 */
1678				err = -ENOTSUPP;
1679				goto out_no_dst;
1680			}
1681			if (sin6->sin6_port == 0) {
1682				/* BPF program set invalid port. Reject it. */
1683				err = -EINVAL;
1684				goto out_no_dst;
1685			}
1686			fl6->fl6_dport = sin6->sin6_port;
1687			fl6->daddr = sin6->sin6_addr;
1688		}
1689	}
1690
1691	if (ipv6_addr_any(&fl6->daddr))
1692		fl6->daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1693
1694	final_p = fl6_update_dst(fl6, opt, &final);
1695	if (final_p)
1696		connected = false;
1697
1698	if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr)) {
1699		fl6->flowi6_oif = READ_ONCE(np->mcast_oif);
1700		connected = false;
1701	} else if (!fl6->flowi6_oif)
1702		fl6->flowi6_oif = READ_ONCE(np->ucast_oif);
1703
1704	security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1705
1706	fl6->flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6->flowlabel);
1707
1708	dst = ip6_sk_dst_lookup_flow(sk, fl6, final_p, connected);
1709	if (IS_ERR(dst)) {
1710		err = PTR_ERR(dst);
1711		dst = NULL;
1712		goto out;
1713	}
1714
1715	if (ipc6.hlimit < 0)
1716		ipc6.hlimit = ip6_sk_dst_hoplimit(np, fl6, dst);
1717
1718	if (msg->msg_flags&MSG_CONFIRM)
1719		goto do_confirm;
1720back_from_confirm:
1721
1722	/* Lockless fast path for the non-corking case */
1723	if (!corkreq) {
1724		struct sk_buff *skb;
1725
1726		skb = ip6_make_skb(sk, getfrag, msg, ulen,
1727				   sizeof(struct udphdr), &ipc6,
1728				   dst_rt6_info(dst),
1729				   msg->msg_flags, &cork);
1730		err = PTR_ERR(skb);
1731		if (!IS_ERR_OR_NULL(skb))
1732			err = udp_v6_send_skb(skb, fl6, &cork.base);
1733		/* ip6_make_skb steals dst reference */
1734		goto out_no_dst;
1735	}
1736
1737	lock_sock(sk);
1738	if (unlikely(up->pending)) {
1739		/* The socket is already corked while preparing it. */
1740		/* ... which is an evident application bug. --ANK */
1741		release_sock(sk);
1742
1743		net_dbg_ratelimited("udp cork app bug 2\n");
1744		err = -EINVAL;
1745		goto out;
1746	}
1747
1748	WRITE_ONCE(up->pending, AF_INET6);
1749
1750do_append_data:
1751	up->len += ulen;
1752	err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1753			      &ipc6, fl6, dst_rt6_info(dst),
1754			      corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1755	if (err)
1756		udp_v6_flush_pending_frames(sk);
1757	else if (!corkreq)
1758		err = udp_v6_push_pending_frames(sk);
1759	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1760		WRITE_ONCE(up->pending, 0);
1761
1762	if (err > 0)
1763		err = inet6_test_bit(RECVERR6, sk) ? net_xmit_errno(err) : 0;
1764	release_sock(sk);
1765
1766out:
1767	dst_release(dst);
1768out_no_dst:
1769	fl6_sock_release(flowlabel);
1770	txopt_put(opt_to_free);
1771	if (!err)
1772		return len;
1773	/*
1774	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1775	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1776	 * we don't have a good statistic (IpOutDiscards but it can be too many
1777	 * things).  We could add another new stat but at least for now that
1778	 * seems like overkill.
1779	 */
1780	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1781		UDP6_INC_STATS(sock_net(sk),
1782			       UDP_MIB_SNDBUFERRORS, is_udplite);
1783	}
1784	return err;
1785
1786do_confirm:
1787	if (msg->msg_flags & MSG_PROBE)
1788		dst_confirm_neigh(dst, &fl6->daddr);
1789	if (!(msg->msg_flags&MSG_PROBE) || len)
1790		goto back_from_confirm;
1791	err = 0;
1792	goto out;
1793}
1794EXPORT_SYMBOL(udpv6_sendmsg);
1795
1796static void udpv6_splice_eof(struct socket *sock)
1797{
1798	struct sock *sk = sock->sk;
1799	struct udp_sock *up = udp_sk(sk);
1800
1801	if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk))
1802		return;
1803
1804	lock_sock(sk);
1805	if (up->pending && !udp_test_bit(CORK, sk))
1806		udp_v6_push_pending_frames(sk);
1807	release_sock(sk);
1808}
1809
1810void udpv6_destroy_sock(struct sock *sk)
1811{
1812	struct udp_sock *up = udp_sk(sk);
1813	lock_sock(sk);
1814
1815	/* protects from races with udp_abort() */
1816	sock_set_flag(sk, SOCK_DEAD);
1817	udp_v6_flush_pending_frames(sk);
1818	release_sock(sk);
1819
1820	if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1821		if (up->encap_type) {
1822			void (*encap_destroy)(struct sock *sk);
1823			encap_destroy = READ_ONCE(up->encap_destroy);
1824			if (encap_destroy)
1825				encap_destroy(sk);
1826		}
1827		if (udp_test_bit(ENCAP_ENABLED, sk)) {
1828			static_branch_dec(&udpv6_encap_needed_key);
1829			udp_encap_disable();
1830			udp_tunnel_cleanup_gro(sk);
1831		}
1832	}
1833}
1834
1835/*
1836 *	Socket option code for UDP
1837 */
1838int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1839		     unsigned int optlen)
1840{
1841	if (level == SOL_UDP  ||  level == SOL_UDPLITE || level == SOL_SOCKET)
1842		return udp_lib_setsockopt(sk, level, optname,
1843					  optval, optlen,
1844					  udp_v6_push_pending_frames);
1845	return ipv6_setsockopt(sk, level, optname, optval, optlen);
1846}
1847
1848int udpv6_getsockopt(struct sock *sk, int level, int optname,
1849		     char __user *optval, int __user *optlen)
1850{
1851	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1852		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1853	return ipv6_getsockopt(sk, level, optname, optval, optlen);
1854}
1855
1856
1857/* ------------------------------------------------------------------------ */
1858#ifdef CONFIG_PROC_FS
1859int udp6_seq_show(struct seq_file *seq, void *v)
1860{
1861	if (v == SEQ_START_TOKEN) {
1862		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1863	} else {
1864		int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1865		const struct inet_sock *inet = inet_sk((const struct sock *)v);
1866		__u16 srcp = ntohs(inet->inet_sport);
1867		__u16 destp = ntohs(inet->inet_dport);
1868		__ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1869					  udp_rqueue_get(v), bucket);
1870	}
1871	return 0;
1872}
1873
1874const struct seq_operations udp6_seq_ops = {
1875	.start		= udp_seq_start,
1876	.next		= udp_seq_next,
1877	.stop		= udp_seq_stop,
1878	.show		= udp6_seq_show,
1879};
1880EXPORT_SYMBOL(udp6_seq_ops);
1881
1882static struct udp_seq_afinfo udp6_seq_afinfo = {
1883	.family		= AF_INET6,
1884	.udp_table	= NULL,
1885};
1886
1887int __net_init udp6_proc_init(struct net *net)
1888{
1889	if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1890			sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1891		return -ENOMEM;
1892	return 0;
1893}
1894
1895void udp6_proc_exit(struct net *net)
1896{
1897	remove_proc_entry("udp6", net->proc_net);
1898}
1899#endif /* CONFIG_PROC_FS */
1900
1901/* ------------------------------------------------------------------------ */
1902
1903struct proto udpv6_prot = {
1904	.name			= "UDPv6",
1905	.owner			= THIS_MODULE,
1906	.close			= udp_lib_close,
1907	.pre_connect		= udpv6_pre_connect,
1908	.connect		= udpv6_connect,
1909	.disconnect		= udp_disconnect,
1910	.ioctl			= udp_ioctl,
1911	.init			= udpv6_init_sock,
1912	.destroy		= udpv6_destroy_sock,
1913	.setsockopt		= udpv6_setsockopt,
1914	.getsockopt		= udpv6_getsockopt,
1915	.sendmsg		= udpv6_sendmsg,
1916	.recvmsg		= udpv6_recvmsg,
1917	.splice_eof		= udpv6_splice_eof,
1918	.release_cb		= ip6_datagram_release_cb,
1919	.hash			= udp_lib_hash,
1920	.unhash			= udp_lib_unhash,
1921	.rehash			= udp_v6_rehash,
1922	.get_port		= udp_v6_get_port,
1923	.put_port		= udp_lib_unhash,
1924#ifdef CONFIG_BPF_SYSCALL
1925	.psock_update_sk_prot	= udp_bpf_update_proto,
1926#endif
1927
1928	.memory_allocated	= &net_aligned_data.udp_memory_allocated,
1929	.per_cpu_fw_alloc	= &udp_memory_per_cpu_fw_alloc,
1930
1931	.sysctl_mem		= sysctl_udp_mem,
1932	.sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1933	.sysctl_rmem_offset     = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1934	.obj_size		= sizeof(struct udp6_sock),
1935	.ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6),
1936	.h.udp_table		= NULL,
1937	.diag_destroy		= udp_abort,
1938};
1939
1940static struct inet_protosw udpv6_protosw = {
1941	.type =      SOCK_DGRAM,
1942	.protocol =  IPPROTO_UDP,
1943	.prot =      &udpv6_prot,
1944	.ops =       &inet6_dgram_ops,
1945	.flags =     INET_PROTOSW_PERMANENT,
1946};
1947
1948int __init udpv6_init(void)
1949{
1950	int ret;
1951
1952	net_hotdata.udpv6_protocol = (struct inet6_protocol) {
1953		.handler     = udpv6_rcv,
1954		.err_handler = udpv6_err,
1955		.flags	     = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1956	};
1957	ret = inet6_add_protocol(&net_hotdata.udpv6_protocol, IPPROTO_UDP);
1958	if (ret)
1959		goto out;
1960
1961	ret = inet6_register_protosw(&udpv6_protosw);
1962	if (ret)
1963		goto out_udpv6_protocol;
1964out:
1965	return ret;
1966
1967out_udpv6_protocol:
1968	inet6_del_protocol(&net_hotdata.udpv6_protocol, IPPROTO_UDP);
1969	goto out;
1970}
1971
1972void udpv6_exit(void)
1973{
1974	inet6_unregister_protosw(&udpv6_protosw);
1975	inet6_del_protocol(&net_hotdata.udpv6_protocol, IPPROTO_UDP);
1976}