[mirror_ubuntu-eoan-kernel.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/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>

u32 inet6_ehashfn(const struct net *net,
		  const struct in6_addr *laddr, const u16 lport,
		  const struct in6_addr *faddr, const __be16 fport)
{
	static u32 inet6_ehash_secret __read_mostly;
	static u32 ipv6_hash_secret __read_mostly;

	u32 lhash, fhash;

	net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
	net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));

	lhash = (__force u32)laddr->s6_addr32[3];
	fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);

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

/*
 * 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(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(sk, net, saddr, daddr, ports, dif, sdif))
			continue;
		if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
			goto out;

		if (unlikely(!INET6_MATCH(sk, net, 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, struct net *net,
				const unsigned short hnum,
				const struct in6_addr *daddr,
				const int dif, const int sdif, bool exact_dif)
{
	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 = 1;
		if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
			score++;
	}
	return score;
}

/* called with rcu_read_lock() */
static struct sock *inet6_lhash2_lookup(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)
{
	bool exact_dif = inet6_exact_dif_match(net, skb);
	struct inet_connection_sock *icsk;
	struct sock *sk, *result = NULL;
	int score, hiscore = 0;
	u32 phash = 0;

	inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
		sk = (struct sock *)icsk;
		score = compute_score(sk, net, hnum, daddr, dif, sdif,
				      exact_dif);
		if (score > hiscore) {
			if (sk->sk_reuseport) {
				phash = inet6_ehashfn(net, daddr, hnum,
						      saddr, sport);
				result = reuseport_select_sock(sk, phash,
							       skb, doff);
				if (result)
					return result;
			}
			result = sk;
			hiscore = score;
		}
	}

	return result;
}

struct sock *inet6_lookup_listener(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;

	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(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)
{
	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);
	const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
						inet->inet_dport);
	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
	spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
	struct sock *sk2;
	const struct hlist_nulls_node *node;
	struct inet_timewait_sock *tw = NULL;

	spin_lock(lock);

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

		if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
				       dif, sdif))) {
			if (sk2->sk_state == TCP_TIME_WAIT) {
				tw = inet_twsk(sk2);
				if (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 u32 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)
{
	u32 port_offset = 0;

	if (!inet_sk(sk)->inet_num)
		port_offset = inet6_sk_port_offset(sk);
	return __inet_hash_connect(death_row, sk, port_offset,
				   __inet6_check_established);
}
EXPORT_SYMBOL_GPL(inet6_hash_connect);

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

	if (sk->sk_state != TCP_CLOSE) {
		local_bh_disable();
		err = __inet_hash(sk, NULL);
		local_bh_enable();
	}

	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/inet_connection_sock.h>
	18	#include <net/inet_hashtables.h>
	19	#include <net/inet6_hashtables.h>
	20	#include <net/secure_seq.h>
	21	#include <net/ip.h>
	22	#include <net/sock_reuseport.h>
	23
	24	u32 inet6_ehashfn(const struct net *net,
	25	const struct in6_addr *laddr, const u16 lport,
	26	const struct in6_addr *faddr, const __be16 fport)
	27	{
	28	static u32 inet6_ehash_secret __read_mostly;
	29	static u32 ipv6_hash_secret __read_mostly;
	30
	31	u32 lhash, fhash;
	32
	33	net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
	34	net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
	35
	36	lhash = (__force u32)laddr->s6_addr32[3];
	37	fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);
	38
	39	return __inet6_ehashfn(lhash, lport, fhash, fport,
	40	inet6_ehash_secret + net_hash_mix(net));
	41	}
	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(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(sk, net, 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(sk, net, 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, struct net net,
	93	const unsigned short hnum,
	94	const struct in6_addr *daddr,
	95	const int dif, const int sdif, bool exact_dif)
	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 = 1;
	108	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
	109	score++;
	110	}
	111	return score;
	112	}
	113
	114	/* called with rcu_read_lock() */
	115	static struct sock inet6_lhash2_lookup(struct net net,
	116	struct inet_listen_hashbucket *ilb2,
	117	struct sk_buff *skb, int doff,
	118	const struct in6_addr *saddr,
	119	const __be16 sport, const struct in6_addr *daddr,
	120	const unsigned short hnum, const int dif, const int sdif)
	121	{
	122	bool exact_dif = inet6_exact_dif_match(net, skb);
	123	struct inet_connection_sock *icsk;
	124	struct sock sk, result = NULL;
	125	int score, hiscore = 0;
	126	u32 phash = 0;
	127
	128	inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
	129	sk = (struct sock *)icsk;
	130	score = compute_score(sk, net, hnum, daddr, dif, sdif,
	131	exact_dif);
	132	if (score > hiscore) {
	133	if (sk->sk_reuseport) {
	134	phash = inet6_ehashfn(net, daddr, hnum,
	135	saddr, sport);
	136	result = reuseport_select_sock(sk, phash,
	137	skb, doff);
	138	if (result)
	139	return result;
	140	}
	141	result = sk;
	142	hiscore = score;
	143	}
	144	}
	145
	146	return result;
	147	}
	148
	149	struct sock inet6_lookup_listener(struct net net,
	150	struct inet_hashinfo *hashinfo,
	151	struct sk_buff *skb, int doff,
	152	const struct in6_addr *saddr,
	153	const __be16 sport, const struct in6_addr *daddr,
	154	const unsigned short hnum, const int dif, const int sdif)
	155	{
	156	struct inet_listen_hashbucket *ilb2;
	157	struct sock *result = NULL;
	158	unsigned int hash2;
	159
	160	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
	161	ilb2 = inet_lhash2_bucket(hashinfo, hash2);
	162
	163	result = inet6_lhash2_lookup(net, ilb2, skb, doff,
	164	saddr, sport, daddr, hnum,
	165	dif, sdif);
	166	if (result)
	167	goto done;
	168
	169	/* Lookup lhash2 with in6addr_any */
	170	hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
	171	ilb2 = inet_lhash2_bucket(hashinfo, hash2);
	172
	173	result = inet6_lhash2_lookup(net, ilb2, skb, doff,
	174	saddr, sport, &in6addr_any, hnum,
	175	dif, sdif);
	176	done:
	177	if (IS_ERR(result))
	178	return NULL;
	179	return result;
	180	}
	181	EXPORT_SYMBOL_GPL(inet6_lookup_listener);
	182
	183	struct sock inet6_lookup(struct net net, struct inet_hashinfo *hashinfo,
	184	struct sk_buff *skb, int doff,
	185	const struct in6_addr *saddr, const __be16 sport,
	186	const struct in6_addr *daddr, const __be16 dport,
	187	const int dif)
	188	{
	189	struct sock *sk;
	190	bool refcounted;
	191
	192	sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
	193	ntohs(dport), dif, 0, &refcounted);
	194	if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
	195	sk = NULL;
	196	return sk;
	197	}
	198	EXPORT_SYMBOL_GPL(inet6_lookup);
	199
	200	static int __inet6_check_established(struct inet_timewait_death_row *death_row,
	201	struct sock *sk, const __u16 lport,
	202	struct inet_timewait_sock **twp)
	203	{
	204	struct inet_hashinfo *hinfo = death_row->hashinfo;
	205	struct inet_sock *inet = inet_sk(sk);
	206	const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
	207	const struct in6_addr *saddr = &sk->sk_v6_daddr;
	208	const int dif = sk->sk_bound_dev_if;
	209	struct net *net = sock_net(sk);
	210	const int sdif = l3mdev_master_ifindex_by_index(net, dif);
	211	const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
	212	const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
	213	inet->inet_dport);
	214	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
	215	spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
	216	struct sock *sk2;
	217	const struct hlist_nulls_node *node;
	218	struct inet_timewait_sock *tw = NULL;
	219
	220	spin_lock(lock);
	221
	222	sk_nulls_for_each(sk2, node, &head->chain) {
	223	if (sk2->sk_hash != hash)
	224	continue;
	225
	226	if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
	227	dif, sdif))) {
	228	if (sk2->sk_state == TCP_TIME_WAIT) {
	229	tw = inet_twsk(sk2);
	230	if (twsk_unique(sk, sk2, twp))
	231	break;
	232	}
	233	goto not_unique;
	234	}
	235	}
	236
	237	/* Must record num and sport now. Otherwise we will see
	238	* in hash table socket with a funny identity.
	239	*/
	240	inet->inet_num = lport;
	241	inet->inet_sport = htons(lport);
	242	sk->sk_hash = hash;
	243	WARN_ON(!sk_unhashed(sk));
	244	__sk_nulls_add_node_rcu(sk, &head->chain);
	245	if (tw) {
	246	sk_nulls_del_node_init_rcu((struct sock *)tw);
	247	__NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
	248	}
	249	spin_unlock(lock);
	250	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
	251
	252	if (twp) {
	253	*twp = tw;
	254	} else if (tw) {
	255	/* Silly. Should hash-dance instead... */
	256	inet_twsk_deschedule_put(tw);
	257	}
	258	return 0;
	259
	260	not_unique:
	261	spin_unlock(lock);
	262	return -EADDRNOTAVAIL;
	263	}
	264
	265	static u32 inet6_sk_port_offset(const struct sock *sk)
	266	{
	267	const struct inet_sock *inet = inet_sk(sk);
	268
	269	return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
	270	sk->sk_v6_daddr.s6_addr32,
	271	inet->inet_dport);
	272	}
	273
	274	int inet6_hash_connect(struct inet_timewait_death_row *death_row,
	275	struct sock *sk)
	276	{
	277	u32 port_offset = 0;
	278
	279	if (!inet_sk(sk)->inet_num)
	280	port_offset = inet6_sk_port_offset(sk);
	281	return __inet_hash_connect(death_row, sk, port_offset,
	282	__inet6_check_established);
	283	}
	284	EXPORT_SYMBOL_GPL(inet6_hash_connect);
	285
	286	int inet6_hash(struct sock *sk)
	287	{
	288	int err = 0;
	289
	290	if (sk->sk_state != TCP_CLOSE) {
	291	local_bh_disable();
	292	err = __inet_hash(sk, NULL);
	293	local_bh_enable();
	294	}
	295
	296	return err;
	297	}
	298	EXPORT_SYMBOL_GPL(inet6_hash);