| // 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> |
| |
| extern struct inet_hashinfo tcp_hashinfo; |
| |
| 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) |
| { |
| 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; |
| } |
| |
| static inline struct sock *lookup_reuseport(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) |
| { |
| struct sock *reuse_sk = NULL; |
| u32 phash; |
| |
| if (sk->sk_reuseport) { |
| phash = inet6_ehashfn(net, daddr, hnum, saddr, sport); |
| reuse_sk = reuseport_select_sock(sk, phash, skb, doff); |
| } |
| return reuse_sk; |
| } |
| |
| /* 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) |
| { |
| struct inet_connection_sock *icsk; |
| struct sock *sk, *result = NULL; |
| int score, hiscore = 0; |
| |
| inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) { |
| sk = (struct sock *)icsk; |
| score = compute_score(sk, net, hnum, daddr, dif, sdif); |
| if (score > hiscore) { |
| result = lookup_reuseport(net, sk, skb, doff, |
| saddr, sport, daddr, hnum); |
| if (result) |
| return result; |
| |
| result = sk; |
| hiscore = score; |
| } |
| } |
| |
| return result; |
| } |
| |
| static inline struct sock *inet6_lookup_run_bpf(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 u16 hnum, const int dif) |
| { |
| struct sock *sk, *reuse_sk; |
| bool no_reuseport; |
| |
| if (hashinfo != &tcp_hashinfo) |
| return NULL; /* only TCP is supported */ |
| |
| no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_TCP, saddr, sport, |
| daddr, hnum, dif, &sk); |
| if (no_reuseport || IS_ERR_OR_NULL(sk)) |
| return sk; |
| |
| reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum); |
| if (reuse_sk) |
| sk = reuse_sk; |
| return sk; |
| } |
| |
| 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; |
| |
| /* Lookup redirect from BPF */ |
| if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { |
| result = inet6_lookup_run_bpf(net, hashinfo, skb, doff, |
| saddr, sport, daddr, hnum, dif); |
| 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(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) |
| err = __inet_hash(sk, NULL); |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(inet6_hash); |