[linux-block.git] / net / ipv6 / inet6_hashtables.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Generic INET6 transport hashtables
 *
 * Authors:	Lotsa people, from code originally in tcp, generalised here
 *		by Arnaldo Carvalho de Melo <acme@mandriva.com>
 */

#include <linux/module.h>
#include <linux/random.h>

#include <net/addrconf.h>
#include <net/hotdata.h>
#include <net/inet_connection_sock.h>
#include <net/inet_hashtables.h>
#include <net/inet6_hashtables.h>
#include <net/secure_seq.h>
#include <net/ip.h>
#include <net/sock_reuseport.h>
#include <net/tcp.h>

u32 inet6_ehashfn(const struct net *net,
		  const struct in6_addr *laddr, const u16 lport,
		  const struct in6_addr *faddr, const __be16 fport)
{
	u32 lhash, fhash;

	net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
	net_get_random_once(&tcp_ipv6_hash_secret, sizeof(tcp_ipv6_hash_secret));

	lhash = (__force u32)laddr->s6_addr32[3];
	fhash = __ipv6_addr_jhash(faddr, tcp_ipv6_hash_secret);

	return lport + __inet6_ehashfn(lhash, 0, fhash, fport,
				       inet6_ehash_secret + net_hash_mix(net));
}
EXPORT_SYMBOL_GPL(inet6_ehashfn);

/*
 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
 *
 * The sockhash lock must be held as a reader here.
 */
struct sock *__inet6_lookup_established(const struct net *net,
					struct inet_hashinfo *hashinfo,
					   const struct in6_addr *saddr,
					   const __be16 sport,
					   const struct in6_addr *daddr,
					   const u16 hnum,
					   const int dif, const int sdif)
{
	struct sock *sk;
	const struct hlist_nulls_node *node;
	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
	/* Optimize here for direct hit, only listening connections can
	 * have wildcards anyways.
	 */
	unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
	unsigned int slot = hash & hashinfo->ehash_mask;
	struct inet_ehash_bucket *head = &hashinfo->ehash[slot];


begin:
	sk_nulls_for_each_rcu(sk, node, &head->chain) {
		if (sk->sk_hash != hash)
			continue;
		if (!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
			continue;
		if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
			goto out;

		if (unlikely(!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))) {
			sock_gen_put(sk);
			goto begin;
		}
		goto found;
	}
	if (get_nulls_value(node) != slot)
		goto begin;
out:
	sk = NULL;
found:
	return sk;
}
EXPORT_SYMBOL(__inet6_lookup_established);

static inline int compute_score(struct sock *sk, const struct net *net,
				const unsigned short hnum,
				const struct in6_addr *daddr,
				const int dif, const int sdif)
{
	int score = -1;

	if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
	    sk->sk_family == PF_INET6) {
		if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
			return -1;

		if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
			return -1;

		score =  sk->sk_bound_dev_if ? 2 : 1;
		if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
			score++;
	}
	return score;
}

/**
 * inet6_lookup_reuseport() - execute reuseport logic on AF_INET6 socket if necessary.
 * @net: network namespace.
 * @sk: AF_INET6 socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
 * @skb: context for a potential SK_REUSEPORT program.
 * @doff: header offset.
 * @saddr: source address.
 * @sport: source port.
 * @daddr: destination address.
 * @hnum: destination port in host byte order.
 * @ehashfn: hash function used to generate the fallback hash.
 *
 * Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
 *         the selected sock or an error.
 */
struct sock *inet6_lookup_reuseport(const struct net *net, struct sock *sk,
				    struct sk_buff *skb, int doff,
				    const struct in6_addr *saddr,
				    __be16 sport,
				    const struct in6_addr *daddr,
				    unsigned short hnum,
				    inet6_ehashfn_t *ehashfn)
{
	struct sock *reuse_sk = NULL;
	u32 phash;

	if (sk->sk_reuseport) {
		phash = INDIRECT_CALL_INET(ehashfn, udp6_ehashfn, inet6_ehashfn,
					   net, daddr, hnum, saddr, sport);
		reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
	}
	return reuse_sk;
}
EXPORT_SYMBOL_GPL(inet6_lookup_reuseport);

/* called with rcu_read_lock() */
static struct sock *inet6_lhash2_lookup(const struct net *net,
		struct inet_listen_hashbucket *ilb2,
		struct sk_buff *skb, int doff,
		const struct in6_addr *saddr,
		const __be16 sport, const struct in6_addr *daddr,
		const unsigned short hnum, const int dif, const int sdif)
{
	struct sock *sk, *result = NULL;
	struct hlist_nulls_node *node;
	int score, hiscore = 0;

	sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
		score = compute_score(sk, net, hnum, daddr, dif, sdif);
		if (score > hiscore) {
			result = inet6_lookup_reuseport(net, sk, skb, doff,
							saddr, sport, daddr, hnum, inet6_ehashfn);
			if (result)
				return result;

			result = sk;
			hiscore = score;
		}
	}

	return result;
}

struct sock *inet6_lookup_run_sk_lookup(const struct net *net,
					int protocol,
					struct sk_buff *skb, int doff,
					const struct in6_addr *saddr,
					const __be16 sport,
					const struct in6_addr *daddr,
					const u16 hnum, const int dif,
					inet6_ehashfn_t *ehashfn)
{
	struct sock *sk, *reuse_sk;
	bool no_reuseport;

	no_reuseport = bpf_sk_lookup_run_v6(net, protocol, saddr, sport,
					    daddr, hnum, dif, &sk);
	if (no_reuseport || IS_ERR_OR_NULL(sk))
		return sk;

	reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
					  saddr, sport, daddr, hnum, ehashfn);
	if (reuse_sk)
		sk = reuse_sk;
	return sk;
}
EXPORT_SYMBOL_GPL(inet6_lookup_run_sk_lookup);

struct sock *inet6_lookup_listener(const struct net *net,
		struct inet_hashinfo *hashinfo,
		struct sk_buff *skb, int doff,
		const struct in6_addr *saddr,
		const __be16 sport, const struct in6_addr *daddr,
		const unsigned short hnum, const int dif, const int sdif)
{
	struct inet_listen_hashbucket *ilb2;
	struct sock *result = NULL;
	unsigned int hash2;

	/* Lookup redirect from BPF */
	if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
	    hashinfo == net->ipv4.tcp_death_row.hashinfo) {
		result = inet6_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
						    saddr, sport, daddr, hnum, dif,
						    inet6_ehashfn);
		if (result)
			goto done;
	}

	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
	ilb2 = inet_lhash2_bucket(hashinfo, hash2);

	result = inet6_lhash2_lookup(net, ilb2, skb, doff,
				     saddr, sport, daddr, hnum,
				     dif, sdif);
	if (result)
		goto done;

	/* Lookup lhash2 with in6addr_any */
	hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
	ilb2 = inet_lhash2_bucket(hashinfo, hash2);

	result = inet6_lhash2_lookup(net, ilb2, skb, doff,
				     saddr, sport, &in6addr_any, hnum,
				     dif, sdif);
done:
	if (IS_ERR(result))
		return NULL;
	return result;
}
EXPORT_SYMBOL_GPL(inet6_lookup_listener);

struct sock *inet6_lookup(const struct net *net,
			  struct inet_hashinfo *hashinfo,
			  struct sk_buff *skb, int doff,
			  const struct in6_addr *saddr, const __be16 sport,
			  const struct in6_addr *daddr, const __be16 dport,
			  const int dif)
{
	struct sock *sk;
	bool refcounted;

	sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
			    ntohs(dport), dif, 0, &refcounted);
	if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
		sk = NULL;
	return sk;
}
EXPORT_SYMBOL_GPL(inet6_lookup);

static int __inet6_check_established(struct inet_timewait_death_row *death_row,
				     struct sock *sk, const __u16 lport,
				     struct inet_timewait_sock **twp,
				     bool rcu_lookup,
				     u32 hash)
{
	struct inet_hashinfo *hinfo = death_row->hashinfo;
	struct inet_sock *inet = inet_sk(sk);
	const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
	const struct in6_addr *saddr = &sk->sk_v6_daddr;
	const int dif = sk->sk_bound_dev_if;
	struct net *net = sock_net(sk);
	const int sdif = l3mdev_master_ifindex_by_index(net, dif);
	const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
	struct inet_timewait_sock *tw = NULL;
	const struct hlist_nulls_node *node;
	struct sock *sk2;
	spinlock_t *lock;

	if (rcu_lookup) {
		sk_nulls_for_each(sk2, node, &head->chain) {
			if (sk2->sk_hash != hash ||
			    !inet6_match(net, sk2, saddr, daddr,
					 ports, dif, sdif))
				continue;
			if (sk2->sk_state == TCP_TIME_WAIT)
				break;
			return -EADDRNOTAVAIL;
		}
		return 0;
	}

	lock = inet_ehash_lockp(hinfo, hash);
	spin_lock(lock);

	sk_nulls_for_each(sk2, node, &head->chain) {
		if (sk2->sk_hash != hash)
			continue;

		if (likely(inet6_match(net, sk2, saddr, daddr, ports,
				       dif, sdif))) {
			if (sk2->sk_state == TCP_TIME_WAIT) {
				tw = inet_twsk(sk2);
				if (sk->sk_protocol == IPPROTO_TCP &&
				    tcp_twsk_unique(sk, sk2, twp))
					break;
			}
			goto not_unique;
		}
	}

	/* Must record num and sport now. Otherwise we will see
	 * in hash table socket with a funny identity.
	 */
	inet->inet_num = lport;
	inet->inet_sport = htons(lport);
	sk->sk_hash = hash;
	WARN_ON(!sk_unhashed(sk));
	__sk_nulls_add_node_rcu(sk, &head->chain);
	if (tw) {
		sk_nulls_del_node_init_rcu((struct sock *)tw);
		__NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
	}
	spin_unlock(lock);
	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);

	if (twp) {
		*twp = tw;
	} else if (tw) {
		/* Silly. Should hash-dance instead... */
		inet_twsk_deschedule_put(tw);
	}
	return 0;

not_unique:
	spin_unlock(lock);
	return -EADDRNOTAVAIL;
}

static u64 inet6_sk_port_offset(const struct sock *sk)
{
	const struct inet_sock *inet = inet_sk(sk);

	return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
					  sk->sk_v6_daddr.s6_addr32,
					  inet->inet_dport);
}

int inet6_hash_connect(struct inet_timewait_death_row *death_row,
		       struct sock *sk)
{
	const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
	const struct in6_addr *saddr = &sk->sk_v6_daddr;
	const struct inet_sock *inet = inet_sk(sk);
	const struct net *net = sock_net(sk);
	u64 port_offset = 0;
	u32 hash_port0;

	if (!inet_sk(sk)->inet_num)
		port_offset = inet6_sk_port_offset(sk);

	hash_port0 = inet6_ehashfn(net, daddr, 0, saddr, inet->inet_dport);

	return __inet_hash_connect(death_row, sk, port_offset, hash_port0,
				   __inet6_check_established);
}
EXPORT_SYMBOL_GPL(inet6_hash_connect);

int inet6_hash(struct sock *sk)
{
	int err = 0;

	if (sk->sk_state != TCP_CLOSE)
		err = __inet_hash(sk, NULL);

	return err;
}
EXPORT_SYMBOL_GPL(inet6_hash);
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* INET An implementation of the TCP/IP protocol suite for the LINUX
	4	* operating system. INET is implemented using the BSD Socket
	5	* interface as the means of communication with the user level.
	6	*
	7	* Generic INET6 transport hashtables
	8	*
	9	* Authors: Lotsa people, from code originally in tcp, generalised here
	10	* by Arnaldo Carvalho de Melo <acme@mandriva.com>
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/random.h>
	15
	16	#include <net/addrconf.h>
	17	#include <net/hotdata.h>
	18	#include <net/inet_connection_sock.h>
	19	#include <net/inet_hashtables.h>
	20	#include <net/inet6_hashtables.h>
	21	#include <net/secure_seq.h>
	22	#include <net/ip.h>
	23	#include <net/sock_reuseport.h>
	24	#include <net/tcp.h>
	25
	26	u32 inet6_ehashfn(const struct net *net,
	27	const struct in6_addr *laddr, const u16 lport,
	28	const struct in6_addr *faddr, const __be16 fport)
	29	{
	30	u32 lhash, fhash;
	31
	32	net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
	33	net_get_random_once(&tcp_ipv6_hash_secret, sizeof(tcp_ipv6_hash_secret));
	34
	35	lhash = (__force u32)laddr->s6_addr32[3];
	36	fhash = __ipv6_addr_jhash(faddr, tcp_ipv6_hash_secret);
	37
	38	return lport + __inet6_ehashfn(lhash, 0, fhash, fport,
	39	inet6_ehash_secret + net_hash_mix(net));
	40	}
	41	EXPORT_SYMBOL_GPL(inet6_ehashfn);
	42
	43	/*
	44	* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
	45	* we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
	46	*
	47	* The sockhash lock must be held as a reader here.
	48	*/
	49	struct sock __inet6_lookup_established(const struct net net,
	50	struct inet_hashinfo *hashinfo,
	51	const struct in6_addr *saddr,
	52	const __be16 sport,
	53	const struct in6_addr *daddr,
	54	const u16 hnum,
	55	const int dif, const int sdif)
	56	{
	57	struct sock *sk;
	58	const struct hlist_nulls_node *node;
	59	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
	60	/* Optimize here for direct hit, only listening connections can
	61	* have wildcards anyways.
	62	*/
	63	unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
	64	unsigned int slot = hash & hashinfo->ehash_mask;
	65	struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
	66
	67
	68	begin:
	69	sk_nulls_for_each_rcu(sk, node, &head->chain) {
	70	if (sk->sk_hash != hash)
	71	continue;
	72	if (!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
	73	continue;
	74	if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
	75	goto out;
	76
	77	if (unlikely(!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))) {
	78	sock_gen_put(sk);
	79	goto begin;
	80	}
	81	goto found;
	82	}
	83	if (get_nulls_value(node) != slot)
	84	goto begin;
	85	out:
	86	sk = NULL;
	87	found:
	88	return sk;
	89	}
	90	EXPORT_SYMBOL(__inet6_lookup_established);
	91
	92	static inline int compute_score(struct sock sk, const struct net net,
	93	const unsigned short hnum,
	94	const struct in6_addr *daddr,
	95	const int dif, const int sdif)
	96	{
	97	int score = -1;
	98
	99	if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
	100	sk->sk_family == PF_INET6) {
	101	if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
	102	return -1;
	103
	104	if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
	105	return -1;
	106
	107	score = sk->sk_bound_dev_if ? 2 : 1;
	108	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
	109	score++;
	110	}
	111	return score;
	112	}
	113
	114	/**
	115	* inet6_lookup_reuseport() - execute reuseport logic on AF_INET6 socket if necessary.
	116	* @net: network namespace.
	117	* @sk: AF_INET6 socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
	118	* @skb: context for a potential SK_REUSEPORT program.
	119	* @doff: header offset.
	120	* @saddr: source address.
	121	* @sport: source port.
	122	* @daddr: destination address.
	123	* @hnum: destination port in host byte order.
	124	* @ehashfn: hash function used to generate the fallback hash.
	125	*
	126	* Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
	127	* the selected sock or an error.
	128	*/
	129	struct sock inet6_lookup_reuseport(const struct net net, struct sock *sk,
	130	struct sk_buff *skb, int doff,
	131	const struct in6_addr *saddr,
	132	__be16 sport,
	133	const struct in6_addr *daddr,
	134	unsigned short hnum,
	135	inet6_ehashfn_t *ehashfn)
	136	{
	137	struct sock *reuse_sk = NULL;
	138	u32 phash;
	139
	140	if (sk->sk_reuseport) {
	141	phash = INDIRECT_CALL_INET(ehashfn, udp6_ehashfn, inet6_ehashfn,
	142	net, daddr, hnum, saddr, sport);
	143	reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
	144	}
	145	return reuse_sk;
	146	}
	147	EXPORT_SYMBOL_GPL(inet6_lookup_reuseport);
	148
	149	/* called with rcu_read_lock() */
	150	static struct sock inet6_lhash2_lookup(const struct net net,
	151	struct inet_listen_hashbucket *ilb2,
	152	struct sk_buff *skb, int doff,
	153	const struct in6_addr *saddr,
	154	const __be16 sport, const struct in6_addr *daddr,
	155	const unsigned short hnum, const int dif, const int sdif)
	156	{
	157	struct sock sk, result = NULL;
	158	struct hlist_nulls_node *node;
	159	int score, hiscore = 0;
	160
	161	sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
	162	score = compute_score(sk, net, hnum, daddr, dif, sdif);
	163	if (score > hiscore) {
	164	result = inet6_lookup_reuseport(net, sk, skb, doff,
	165	saddr, sport, daddr, hnum, inet6_ehashfn);
	166	if (result)
	167	return result;
	168
	169	result = sk;
	170	hiscore = score;
	171	}
	172	}
	173
	174	return result;
	175	}
	176
	177	struct sock inet6_lookup_run_sk_lookup(const struct net net,
	178	int protocol,
	179	struct sk_buff *skb, int doff,
	180	const struct in6_addr *saddr,
	181	const __be16 sport,
	182	const struct in6_addr *daddr,
	183	const u16 hnum, const int dif,
	184	inet6_ehashfn_t *ehashfn)
	185	{
	186	struct sock sk, reuse_sk;
	187	bool no_reuseport;
	188
	189	no_reuseport = bpf_sk_lookup_run_v6(net, protocol, saddr, sport,
	190	daddr, hnum, dif, &sk);
	191	if (no_reuseport \|\| IS_ERR_OR_NULL(sk))
	192	return sk;
	193
	194	reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
	195	saddr, sport, daddr, hnum, ehashfn);
	196	if (reuse_sk)
	197	sk = reuse_sk;
	198	return sk;
	199	}
	200	EXPORT_SYMBOL_GPL(inet6_lookup_run_sk_lookup);
	201
	202	struct sock inet6_lookup_listener(const struct net net,
	203	struct inet_hashinfo *hashinfo,
	204	struct sk_buff *skb, int doff,
	205	const struct in6_addr *saddr,
	206	const __be16 sport, const struct in6_addr *daddr,
	207	const unsigned short hnum, const int dif, const int sdif)
	208	{
	209	struct inet_listen_hashbucket *ilb2;
	210	struct sock *result = NULL;
	211	unsigned int hash2;
	212
	213	/* Lookup redirect from BPF */
	214	if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
	215	hashinfo == net->ipv4.tcp_death_row.hashinfo) {
	216	result = inet6_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
	217	saddr, sport, daddr, hnum, dif,
	218	inet6_ehashfn);
	219	if (result)
	220	goto done;
	221	}
	222
	223	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
	224	ilb2 = inet_lhash2_bucket(hashinfo, hash2);
	225
	226	result = inet6_lhash2_lookup(net, ilb2, skb, doff,
	227	saddr, sport, daddr, hnum,
	228	dif, sdif);
	229	if (result)
	230	goto done;
	231
	232	/* Lookup lhash2 with in6addr_any */
	233	hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
	234	ilb2 = inet_lhash2_bucket(hashinfo, hash2);
	235
	236	result = inet6_lhash2_lookup(net, ilb2, skb, doff,
	237	saddr, sport, &in6addr_any, hnum,
	238	dif, sdif);
	239	done:
	240	if (IS_ERR(result))
	241	return NULL;
	242	return result;
	243	}
	244	EXPORT_SYMBOL_GPL(inet6_lookup_listener);
	245
	246	struct sock inet6_lookup(const struct net net,
	247	struct inet_hashinfo *hashinfo,
	248	struct sk_buff *skb, int doff,
	249	const struct in6_addr *saddr, const __be16 sport,
	250	const struct in6_addr *daddr, const __be16 dport,
	251	const int dif)
	252	{
	253	struct sock *sk;
	254	bool refcounted;
	255
	256	sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
	257	ntohs(dport), dif, 0, &refcounted);
	258	if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
	259	sk = NULL;
	260	return sk;
	261	}
	262	EXPORT_SYMBOL_GPL(inet6_lookup);
	263
	264	static int __inet6_check_established(struct inet_timewait_death_row *death_row,
	265	struct sock *sk, const __u16 lport,
	266	struct inet_timewait_sock **twp,
	267	bool rcu_lookup,
	268	u32 hash)
	269	{
	270	struct inet_hashinfo *hinfo = death_row->hashinfo;
	271	struct inet_sock *inet = inet_sk(sk);
	272	const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
	273	const struct in6_addr *saddr = &sk->sk_v6_daddr;
	274	const int dif = sk->sk_bound_dev_if;
	275	struct net *net = sock_net(sk);
	276	const int sdif = l3mdev_master_ifindex_by_index(net, dif);
	277	const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
	278	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
	279	struct inet_timewait_sock *tw = NULL;
	280	const struct hlist_nulls_node *node;
	281	struct sock *sk2;
	282	spinlock_t *lock;
	283
	284	if (rcu_lookup) {
	285	sk_nulls_for_each(sk2, node, &head->chain) {
	286	if (sk2->sk_hash != hash \|\|
	287	!inet6_match(net, sk2, saddr, daddr,
	288	ports, dif, sdif))
	289	continue;
	290	if (sk2->sk_state == TCP_TIME_WAIT)
	291	break;
	292	return -EADDRNOTAVAIL;
	293	}
	294	return 0;
	295	}
	296
	297	lock = inet_ehash_lockp(hinfo, hash);
	298	spin_lock(lock);
	299
	300	sk_nulls_for_each(sk2, node, &head->chain) {
	301	if (sk2->sk_hash != hash)
	302	continue;
	303
	304	if (likely(inet6_match(net, sk2, saddr, daddr, ports,
	305	dif, sdif))) {
	306	if (sk2->sk_state == TCP_TIME_WAIT) {
	307	tw = inet_twsk(sk2);
	308	if (sk->sk_protocol == IPPROTO_TCP &&
	309	tcp_twsk_unique(sk, sk2, twp))
	310	break;
	311	}
	312	goto not_unique;
	313	}
	314	}
	315
	316	/* Must record num and sport now. Otherwise we will see
	317	* in hash table socket with a funny identity.
	318	*/
	319	inet->inet_num = lport;
	320	inet->inet_sport = htons(lport);
	321	sk->sk_hash = hash;
	322	WARN_ON(!sk_unhashed(sk));
	323	__sk_nulls_add_node_rcu(sk, &head->chain);
	324	if (tw) {
	325	sk_nulls_del_node_init_rcu((struct sock *)tw);
	326	__NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
	327	}
	328	spin_unlock(lock);
	329	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
	330
	331	if (twp) {
	332	*twp = tw;
	333	} else if (tw) {
	334	/* Silly. Should hash-dance instead... */
	335	inet_twsk_deschedule_put(tw);
	336	}
	337	return 0;
	338
	339	not_unique:
	340	spin_unlock(lock);
	341	return -EADDRNOTAVAIL;
	342	}
	343
	344	static u64 inet6_sk_port_offset(const struct sock *sk)
	345	{
	346	const struct inet_sock *inet = inet_sk(sk);
	347
	348	return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
	349	sk->sk_v6_daddr.s6_addr32,
	350	inet->inet_dport);
	351	}
	352
	353	int inet6_hash_connect(struct inet_timewait_death_row *death_row,
	354	struct sock *sk)
	355	{
	356	const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
	357	const struct in6_addr *saddr = &sk->sk_v6_daddr;
	358	const struct inet_sock *inet = inet_sk(sk);
	359	const struct net *net = sock_net(sk);
	360	u64 port_offset = 0;
	361	u32 hash_port0;
	362
	363	if (!inet_sk(sk)->inet_num)
	364	port_offset = inet6_sk_port_offset(sk);
	365
	366	hash_port0 = inet6_ehashfn(net, daddr, 0, saddr, inet->inet_dport);
	367
	368	return __inet_hash_connect(death_row, sk, port_offset, hash_port0,
	369	__inet6_check_established);
	370	}
	371	EXPORT_SYMBOL_GPL(inet6_hash_connect);
	372
	373	int inet6_hash(struct sock *sk)
	374	{
	375	int err = 0;
	376
	377	if (sk->sk_state != TCP_CLOSE)
	378	err = __inet_hash(sk, NULL);
	379
	380	return err;
	381	}
	382	EXPORT_SYMBOL_GPL(inet6_hash);