1 // SPDX-License-Identifier: GPL-2.0-or-later
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.
7 * Generic INET6 transport hashtables
9 * Authors: Lotsa people, from code originally in tcp, generalised here
10 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
13 #include <linux/module.h>
14 #include <linux/random.h>
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>
22 #include <net/sock_reuseport.h>
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)
28 static u32 inet6_ehash_secret __read_mostly;
29 static u32 ipv6_hash_secret __read_mostly;
33 net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
34 net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
36 lhash = (__force u32)laddr->s6_addr32[3];
37 fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);
39 return __inet6_ehashfn(lhash, lport, fhash, fport,
40 inet6_ehash_secret + net_hash_mix(net));
42 EXPORT_SYMBOL_GPL(inet6_ehashfn);
45 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
46 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
48 * The sockhash lock must be held as a reader here.
50 struct sock *__inet6_lookup_established(struct net *net,
51 struct inet_hashinfo *hashinfo,
52 const struct in6_addr *saddr,
54 const struct in6_addr *daddr,
56 const int dif, const int sdif)
59 const struct hlist_nulls_node *node;
60 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
61 /* Optimize here for direct hit, only listening connections can
62 * have wildcards anyways.
64 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
65 unsigned int slot = hash & hashinfo->ehash_mask;
66 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
70 sk_nulls_for_each_rcu(sk, node, &head->chain) {
71 if (sk->sk_hash != hash)
73 if (!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
75 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
78 if (unlikely(!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))) {
84 if (get_nulls_value(node) != slot)
91 EXPORT_SYMBOL(__inet6_lookup_established);
93 static inline int compute_score(struct sock *sk, struct net *net,
94 const unsigned short hnum,
95 const struct in6_addr *daddr,
96 const int dif, const int sdif)
100 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
101 sk->sk_family == PF_INET6) {
102 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
105 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
108 score = sk->sk_bound_dev_if ? 2 : 1;
109 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
115 INDIRECT_CALLABLE_DECLARE(inet6_ehashfn_t udp6_ehashfn);
118 * inet6_lookup_reuseport() - execute reuseport logic on AF_INET6 socket if necessary.
119 * @net: network namespace.
120 * @sk: AF_INET6 socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
121 * @skb: context for a potential SK_REUSEPORT program.
122 * @doff: header offset.
123 * @saddr: source address.
124 * @sport: source port.
125 * @daddr: destination address.
126 * @hnum: destination port in host byte order.
127 * @ehashfn: hash function used to generate the fallback hash.
129 * Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
130 * the selected sock or an error.
132 struct sock *inet6_lookup_reuseport(struct net *net, struct sock *sk,
133 struct sk_buff *skb, int doff,
134 const struct in6_addr *saddr,
136 const struct in6_addr *daddr,
138 inet6_ehashfn_t *ehashfn)
140 struct sock *reuse_sk = NULL;
143 if (sk->sk_reuseport) {
144 phash = INDIRECT_CALL_INET(ehashfn, udp6_ehashfn, inet6_ehashfn,
145 net, daddr, hnum, saddr, sport);
146 reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
150 EXPORT_SYMBOL_GPL(inet6_lookup_reuseport);
152 /* called with rcu_read_lock() */
153 static struct sock *inet6_lhash2_lookup(struct net *net,
154 struct inet_listen_hashbucket *ilb2,
155 struct sk_buff *skb, int doff,
156 const struct in6_addr *saddr,
157 const __be16 sport, const struct in6_addr *daddr,
158 const unsigned short hnum, const int dif, const int sdif)
160 struct sock *sk, *result = NULL;
161 struct hlist_nulls_node *node;
162 int score, hiscore = 0;
164 sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
165 score = compute_score(sk, net, hnum, daddr, dif, sdif);
166 if (score > hiscore) {
167 result = inet6_lookup_reuseport(net, sk, skb, doff,
168 saddr, sport, daddr, hnum, inet6_ehashfn);
180 struct sock *inet6_lookup_run_sk_lookup(struct net *net,
182 struct sk_buff *skb, int doff,
183 const struct in6_addr *saddr,
185 const struct in6_addr *daddr,
186 const u16 hnum, const int dif,
187 inet6_ehashfn_t *ehashfn)
189 struct sock *sk, *reuse_sk;
192 no_reuseport = bpf_sk_lookup_run_v6(net, protocol, saddr, sport,
193 daddr, hnum, dif, &sk);
194 if (no_reuseport || IS_ERR_OR_NULL(sk))
197 reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
198 saddr, sport, daddr, hnum, ehashfn);
203 EXPORT_SYMBOL_GPL(inet6_lookup_run_sk_lookup);
205 struct sock *inet6_lookup_listener(struct net *net,
206 struct inet_hashinfo *hashinfo,
207 struct sk_buff *skb, int doff,
208 const struct in6_addr *saddr,
209 const __be16 sport, const struct in6_addr *daddr,
210 const unsigned short hnum, const int dif, const int sdif)
212 struct inet_listen_hashbucket *ilb2;
213 struct sock *result = NULL;
216 /* Lookup redirect from BPF */
217 if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
218 hashinfo == net->ipv4.tcp_death_row.hashinfo) {
219 result = inet6_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
220 saddr, sport, daddr, hnum, dif,
226 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
227 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
229 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
230 saddr, sport, daddr, hnum,
235 /* Lookup lhash2 with in6addr_any */
236 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
237 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
239 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
240 saddr, sport, &in6addr_any, hnum,
247 EXPORT_SYMBOL_GPL(inet6_lookup_listener);
249 struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
250 struct sk_buff *skb, int doff,
251 const struct in6_addr *saddr, const __be16 sport,
252 const struct in6_addr *daddr, const __be16 dport,
258 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
259 ntohs(dport), dif, 0, &refcounted);
260 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
264 EXPORT_SYMBOL_GPL(inet6_lookup);
266 static int __inet6_check_established(struct inet_timewait_death_row *death_row,
267 struct sock *sk, const __u16 lport,
268 struct inet_timewait_sock **twp)
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 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
280 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
281 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
283 const struct hlist_nulls_node *node;
284 struct inet_timewait_sock *tw = NULL;
288 sk_nulls_for_each(sk2, node, &head->chain) {
289 if (sk2->sk_hash != hash)
292 if (likely(inet6_match(net, sk2, saddr, daddr, ports,
294 if (sk2->sk_state == TCP_TIME_WAIT) {
296 if (twsk_unique(sk, sk2, twp))
303 /* Must record num and sport now. Otherwise we will see
304 * in hash table socket with a funny identity.
306 inet->inet_num = lport;
307 inet->inet_sport = htons(lport);
309 WARN_ON(!sk_unhashed(sk));
310 __sk_nulls_add_node_rcu(sk, &head->chain);
312 sk_nulls_del_node_init_rcu((struct sock *)tw);
313 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
316 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
321 /* Silly. Should hash-dance instead... */
322 inet_twsk_deschedule_put(tw);
328 return -EADDRNOTAVAIL;
331 static u64 inet6_sk_port_offset(const struct sock *sk)
333 const struct inet_sock *inet = inet_sk(sk);
335 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
336 sk->sk_v6_daddr.s6_addr32,
340 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
345 if (!inet_sk(sk)->inet_num)
346 port_offset = inet6_sk_port_offset(sk);
347 return __inet_hash_connect(death_row, sk, port_offset,
348 __inet6_check_established);
350 EXPORT_SYMBOL_GPL(inet6_hash_connect);
352 int inet6_hash(struct sock *sk)
356 if (sk->sk_state != TCP_CLOSE)
357 err = __inet_hash(sk, NULL);
361 EXPORT_SYMBOL_GPL(inet6_hash);