/* * 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 INET transport hashtables * * Authors: Lotsa people, from code originally in tcp * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/module.h> #include <linux/random.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/wait.h> #include <linux/vmalloc.h> #include <linux/bootmem.h> #include <net/addrconf.h> #include <net/inet_connection_sock.h> #include <net/inet_hashtables.h> #if IS_ENABLED(CONFIG_IPV6) #include <net/inet6_hashtables.h> #endif #include <net/secure_seq.h> #include <net/ip.h> #include <net/tcp.h> #include <net/sock_reuseport.h> static u32 inet_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport, const __be32 faddr, const __be16 fport) { static u32 inet_ehash_secret __read_mostly; net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret)); return __inet_ehashfn(laddr, lport, faddr, fport, inet_ehash_secret + net_hash_mix(net)); } /* This function handles inet_sock, but also timewait and request sockets * for IPv4/IPv6. */ static u32 sk_ehashfn(const struct sock *sk) { #if IS_ENABLED(CONFIG_IPV6) if (sk->sk_family == AF_INET6 && !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) return inet6_ehashfn(sock_net(sk), &sk->sk_v6_rcv_saddr, sk->sk_num, &sk->sk_v6_daddr, sk->sk_dport); #endif return inet_ehashfn(sock_net(sk), sk->sk_rcv_saddr, sk->sk_num, sk->sk_daddr, sk->sk_dport); } /* * Allocate and initialize a new local port bind bucket. * The bindhash mutex for snum's hash chain must be held here. */ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net, struct inet_bind_hashbucket *head, const unsigned short snum) { struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC); if (tb) { write_pnet(&tb->ib_net, net); tb->port = snum; tb->fastreuse = 0; tb->fastreuseport = 0; INIT_HLIST_HEAD(&tb->owners); hlist_add_head(&tb->node, &head->chain); } return tb; } /* * Caller must hold hashbucket lock for this tb with local BH disabled */ void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb) { if (hlist_empty(&tb->owners)) { __hlist_del(&tb->node); kmem_cache_free(cachep, tb); } } void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, const unsigned short snum) { inet_sk(sk)->inet_num = snum; sk_add_bind_node(sk, &tb->owners); inet_csk(sk)->icsk_bind_hash = tb; } /* * Get rid of any references to a local port held by the given sock. */ static void __inet_put_port(struct sock *sk) { struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num, hashinfo->bhash_size); struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash]; struct inet_bind_bucket *tb; spin_lock(&head->lock); tb = inet_csk(sk)->icsk_bind_hash; __sk_del_bind_node(sk); inet_csk(sk)->icsk_bind_hash = NULL; inet_sk(sk)->inet_num = 0; inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb); spin_unlock(&head->lock); } void inet_put_port(struct sock *sk) { local_bh_disable(); __inet_put_port(sk); local_bh_enable(); } EXPORT_SYMBOL(inet_put_port); int __inet_inherit_port(const struct sock *sk, struct sock *child) { struct inet_hashinfo *table = sk->sk_prot->h.hashinfo; unsigned short port = inet_sk(child)->inet_num; const int bhash = inet_bhashfn(sock_net(sk), port, table->bhash_size); struct inet_bind_hashbucket *head = &table->bhash[bhash]; struct inet_bind_bucket *tb; spin_lock(&head->lock); tb = inet_csk(sk)->icsk_bind_hash; if (unlikely(!tb)) { spin_unlock(&head->lock); return -ENOENT; } if (tb->port != port) { /* NOTE: using tproxy and redirecting skbs to a proxy * on a different listener port breaks the assumption * that the listener socket's icsk_bind_hash is the same * as that of the child socket. We have to look up or * create a new bind bucket for the child here. */ inet_bind_bucket_for_each(tb, &head->chain) { if (net_eq(ib_net(tb), sock_net(sk)) && tb->port == port) break; } if (!tb) { tb = inet_bind_bucket_create(table->bind_bucket_cachep, sock_net(sk), head, port); if (!tb) { spin_unlock(&head->lock); return -ENOMEM; } } inet_csk_update_fastreuse(tb, child); } inet_bind_hash(child, tb, port); spin_unlock(&head->lock); return 0; } EXPORT_SYMBOL_GPL(__inet_inherit_port); static struct inet_listen_hashbucket * inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk) { u32 hash; #if IS_ENABLED(CONFIG_IPV6) if (sk->sk_family == AF_INET6) hash = ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, inet_sk(sk)->inet_num); else #endif hash = ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, inet_sk(sk)->inet_num); return inet_lhash2_bucket(h, hash); } static void inet_hash2(struct inet_hashinfo *h, struct sock *sk) { struct inet_listen_hashbucket *ilb2; if (!h->lhash2) return; ilb2 = inet_lhash2_bucket_sk(h, sk); spin_lock(&ilb2->lock); if (sk->sk_reuseport && sk->sk_family == AF_INET6) hlist_add_tail_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, &ilb2->head); else hlist_add_head_rcu(&inet_csk(sk)->icsk_listen_portaddr_node, &ilb2->head); ilb2->count++; spin_unlock(&ilb2->lock); } static void inet_unhash2(struct inet_hashinfo *h, struct sock *sk) { struct inet_listen_hashbucket *ilb2; if (!h->lhash2 || WARN_ON_ONCE(hlist_unhashed(&inet_csk(sk)->icsk_listen_portaddr_node))) return; ilb2 = inet_lhash2_bucket_sk(h, sk); spin_lock(&ilb2->lock); hlist_del_init_rcu(&inet_csk(sk)->icsk_listen_portaddr_node); ilb2->count--; spin_unlock(&ilb2->lock); } static inline int compute_score(struct sock *sk, struct net *net, const unsigned short hnum, const __be32 daddr, const int dif, const int sdif, bool exact_dif) { int score = -1; struct inet_sock *inet = inet_sk(sk); if (net_eq(sock_net(sk), net) && inet->inet_num == hnum && !ipv6_only_sock(sk)) { __be32 rcv_saddr = inet->inet_rcv_saddr; score = sk->sk_family == PF_INET ? 2 : 1; if (rcv_saddr) { if (rcv_saddr != daddr) return -1; score += 4; } if (sk->sk_bound_dev_if || exact_dif) { bool dev_match = (sk->sk_bound_dev_if == dif || sk->sk_bound_dev_if == sdif); if (!dev_match) return -1; if (sk->sk_bound_dev_if) score += 4; } if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) score++; } return score; } /* * Here are some nice properties to exploit here. The BSD API * does not allow a listening sock to specify the remote port nor the * remote address for the connection. So always assume those are both * wildcarded during the search since they can never be otherwise. */ /* called with rcu_read_lock() : No refcount taken on the socket */ static struct sock *inet_lhash2_lookup(struct net *net, struct inet_listen_hashbucket *ilb2, struct sk_buff *skb, int doff, const __be32 saddr, __be16 sport, const __be32 daddr, const unsigned short hnum, const int dif, const int sdif) { bool exact_dif = inet_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 = inet_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 *__inet_lookup_listener(struct net *net, struct inet_hashinfo *hashinfo, struct sk_buff *skb, int doff, const __be32 saddr, __be16 sport, const __be32 daddr, const unsigned short hnum, const int dif, const int sdif) { unsigned int hash = inet_lhashfn(net, hnum); struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash]; bool exact_dif = inet_exact_dif_match(net, skb); struct inet_listen_hashbucket *ilb2; struct sock *sk, *result = NULL; struct hlist_nulls_node *node; int score, hiscore = 0; unsigned int hash2; u32 phash = 0; if (ilb->count <= 10 || !hashinfo->lhash2) goto port_lookup; /* Too many sk in the ilb bucket (which is hashed by port alone). * Try lhash2 (which is hashed by port and addr) instead. */ hash2 = ipv4_portaddr_hash(net, daddr, hnum); ilb2 = inet_lhash2_bucket(hashinfo, hash2); if (ilb2->count > ilb->count) goto port_lookup; result = inet_lhash2_lookup(net, ilb2, skb, doff, saddr, sport, daddr, hnum, dif, sdif); if (result) goto done; /* Lookup lhash2 with INADDR_ANY */ hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); ilb2 = inet_lhash2_bucket(hashinfo, hash2); if (ilb2->count > ilb->count) goto port_lookup; result = inet_lhash2_lookup(net, ilb2, skb, doff, saddr, sport, daddr, hnum, dif, sdif); goto done; port_lookup: sk_nulls_for_each_rcu(sk, node, &ilb->nulls_head) { score = compute_score(sk, net, hnum, daddr, dif, sdif, exact_dif); if (score > hiscore) { if (sk->sk_reuseport) { phash = inet_ehashfn(net, daddr, hnum, saddr, sport); result = reuseport_select_sock(sk, phash, skb, doff); if (result) goto done; } result = sk; hiscore = score; } } done: if (unlikely(IS_ERR(result))) return NULL; return result; } EXPORT_SYMBOL_GPL(__inet_lookup_listener); /* All sockets share common refcount, but have different destructors */ void sock_gen_put(struct sock *sk) { if (!refcount_dec_and_test(&sk->sk_refcnt)) return; if (sk->sk_state == TCP_TIME_WAIT) inet_twsk_free(inet_twsk(sk)); else if (sk->sk_state == TCP_NEW_SYN_RECV) reqsk_free(inet_reqsk(sk)); else sk_free(sk); } EXPORT_SYMBOL_GPL(sock_gen_put); void sock_edemux(struct sk_buff *skb) { sock_gen_put(skb->sk); } EXPORT_SYMBOL(sock_edemux); struct sock *__inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo, const __be32 saddr, const __be16 sport, const __be32 daddr, const u16 hnum, const int dif, const int sdif) { INET_ADDR_COOKIE(acookie, saddr, daddr); const __portpair ports = INET_COMBINED_PORTS(sport, hnum); struct sock *sk; const struct hlist_nulls_node *node; /* Optimize here for direct hit, only listening connections can * have wildcards anyways. */ unsigned int hash = inet_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 (likely(INET_MATCH(sk, net, acookie, saddr, daddr, ports, dif, sdif))) { if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) goto out; if (unlikely(!INET_MATCH(sk, net, acookie, saddr, daddr, ports, dif, sdif))) { sock_gen_put(sk); goto begin; } goto found; } } /* * if the nulls value we got at the end of this lookup is * not the expected one, we must restart lookup. * We probably met an item that was moved to another chain. */ if (get_nulls_value(node) != slot) goto begin; out: sk = NULL; found: return sk; } EXPORT_SYMBOL_GPL(__inet_lookup_established); /* called with local bh disabled */ static int __inet_check_established(struct inet_timewait_death_row *death_row, struct sock *sk, __u16 lport, struct inet_timewait_sock **twp) { struct inet_hashinfo *hinfo = death_row->hashinfo; struct inet_sock *inet = inet_sk(sk); __be32 daddr = inet->inet_rcv_saddr; __be32 saddr = inet->inet_daddr; int dif = sk->sk_bound_dev_if; struct net *net = sock_net(sk); int sdif = l3mdev_master_ifindex_by_index(net, dif); INET_ADDR_COOKIE(acookie, saddr, daddr); const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport); unsigned int hash = inet_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(INET_MATCH(sk2, net, acookie, 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 u64 inet_sk_port_offset(const struct sock *sk) { const struct inet_sock *inet = inet_sk(sk); return secure_ipv4_port_ephemeral(inet->inet_rcv_saddr, inet->inet_daddr, inet->inet_dport); } /* Searches for an exsiting socket in the ehash bucket list. * Returns true if found, false otherwise. */ static bool inet_ehash_lookup_by_sk(struct sock *sk, struct hlist_nulls_head *list) { const __portpair ports = INET_COMBINED_PORTS(sk->sk_dport, sk->sk_num); const int sdif = sk->sk_bound_dev_if; const int dif = sk->sk_bound_dev_if; const struct hlist_nulls_node *node; struct net *net = sock_net(sk); struct sock *esk; INET_ADDR_COOKIE(acookie, sk->sk_daddr, sk->sk_rcv_saddr); sk_nulls_for_each_rcu(esk, node, list) { if (esk->sk_hash != sk->sk_hash) continue; if (sk->sk_family == AF_INET) { if (unlikely(INET_MATCH(esk, net, acookie, sk->sk_daddr, sk->sk_rcv_saddr, ports, dif, sdif))) { return true; } } #if IS_ENABLED(CONFIG_IPV6) else if (sk->sk_family == AF_INET6) { if (unlikely(INET6_MATCH(esk, net, &sk->sk_v6_daddr, &sk->sk_v6_rcv_saddr, ports, dif, sdif))) { return true; } } #endif } return false; } /* Insert a socket into ehash, and eventually remove another one * (The another one can be a SYN_RECV or TIMEWAIT) * If an existing socket already exists, socket sk is not inserted, * and sets found_dup_sk parameter to true. */ bool inet_ehash_insert(struct sock *sk, struct sock *osk, bool *found_dup_sk) { struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; struct hlist_nulls_head *list; struct inet_ehash_bucket *head; spinlock_t *lock; bool ret = true; WARN_ON_ONCE(!sk_unhashed(sk)); sk->sk_hash = sk_ehashfn(sk); head = inet_ehash_bucket(hashinfo, sk->sk_hash); list = &head->chain; lock = inet_ehash_lockp(hashinfo, sk->sk_hash); spin_lock(lock); if (osk) { WARN_ON_ONCE(sk->sk_hash != osk->sk_hash); ret = sk_nulls_del_node_init_rcu(osk); } else if (found_dup_sk) { *found_dup_sk = inet_ehash_lookup_by_sk(sk, list); if (*found_dup_sk) ret = false; } if (ret) __sk_nulls_add_node_rcu(sk, list); spin_unlock(lock); return ret; } bool inet_ehash_nolisten(struct sock *sk, struct sock *osk, bool *found_dup_sk) { bool ok = inet_ehash_insert(sk, osk, found_dup_sk); if (ok) { sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); } else { percpu_counter_inc(sk->sk_prot->orphan_count); inet_sk_set_state(sk, TCP_CLOSE); sock_set_flag(sk, SOCK_DEAD); inet_csk_destroy_sock(sk); } return ok; } EXPORT_SYMBOL_GPL(inet_ehash_nolisten); static int inet_reuseport_add_sock(struct sock *sk, struct inet_listen_hashbucket *ilb) { struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash; const struct hlist_nulls_node *node; struct sock *sk2; kuid_t uid = sock_i_uid(sk); sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) { if (sk2 != sk && sk2->sk_family == sk->sk_family && ipv6_only_sock(sk2) == ipv6_only_sock(sk) && sk2->sk_bound_dev_if == sk->sk_bound_dev_if && inet_csk(sk2)->icsk_bind_hash == tb && sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && inet_rcv_saddr_equal(sk, sk2, false)) return reuseport_add_sock(sk, sk2, inet_rcv_saddr_any(sk)); } return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); } int __inet_hash(struct sock *sk, struct sock *osk) { struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; struct inet_listen_hashbucket *ilb; int err = 0; if (sk->sk_state != TCP_LISTEN) { inet_ehash_nolisten(sk, osk, NULL); return 0; } WARN_ON(!sk_unhashed(sk)); ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; spin_lock(&ilb->lock); if (sk->sk_reuseport) { err = inet_reuseport_add_sock(sk, ilb); if (err) goto unlock; } if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && sk->sk_family == AF_INET6) __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head); else __sk_nulls_add_node_rcu(sk, &ilb->nulls_head); inet_hash2(hashinfo, sk); ilb->count++; sock_set_flag(sk, SOCK_RCU_FREE); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); unlock: spin_unlock(&ilb->lock); return err; } EXPORT_SYMBOL(__inet_hash); int inet_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(inet_hash); void inet_unhash(struct sock *sk) { struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; struct inet_listen_hashbucket *ilb = NULL; spinlock_t *lock; if (sk_unhashed(sk)) return; if (sk->sk_state == TCP_LISTEN) { ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; lock = &ilb->lock; } else { lock = inet_ehash_lockp(hashinfo, sk->sk_hash); } spin_lock_bh(lock); if (sk_unhashed(sk)) goto unlock; if (rcu_access_pointer(sk->sk_reuseport_cb)) reuseport_detach_sock(sk); if (ilb) { inet_unhash2(hashinfo, sk); ilb->count--; } __sk_nulls_del_node_init_rcu(sk); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); unlock: spin_unlock_bh(lock); } EXPORT_SYMBOL_GPL(inet_unhash); /* RFC 6056 3.3.4. Algorithm 4: Double-Hash Port Selection Algorithm * Note that we use 32bit integers (vs RFC 'short integers') * because 2^16 is not a multiple of num_ephemeral and this * property might be used by clever attacker. * RFC claims using TABLE_LENGTH=10 buckets gives an improvement, though * attacks were since demonstrated, thus we use 65536 instead to really * give more isolation and privacy, at the expense of 256kB of kernel * memory. */ #define INET_TABLE_PERTURB_SHIFT 16 #define INET_TABLE_PERTURB_SIZE (1 << INET_TABLE_PERTURB_SHIFT) static u32 *table_perturb; int __inet_hash_connect(struct inet_timewait_death_row *death_row, struct sock *sk, u64 port_offset, int (*check_established)(struct inet_timewait_death_row *, struct sock *, __u16, struct inet_timewait_sock **)) { struct inet_hashinfo *hinfo = death_row->hashinfo; struct inet_timewait_sock *tw = NULL; struct inet_bind_hashbucket *head; int port = inet_sk(sk)->inet_num; struct net *net = sock_net(sk); struct inet_bind_bucket *tb; u32 remaining, offset; int ret, i, low, high; u32 index; if (port) { head = &hinfo->bhash[inet_bhashfn(net, port, hinfo->bhash_size)]; tb = inet_csk(sk)->icsk_bind_hash; spin_lock_bh(&head->lock); if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { inet_ehash_nolisten(sk, NULL, NULL); spin_unlock_bh(&head->lock); return 0; } spin_unlock(&head->lock); /* No definite answer... Walk to established hash table */ ret = check_established(death_row, sk, port, NULL); local_bh_enable(); return ret; } inet_get_local_port_range(net, &low, &high); high++; /* [32768, 60999] -> [32768, 61000[ */ remaining = high - low; if (likely(remaining > 1)) remaining &= ~1U; net_get_random_once(table_perturb, INET_TABLE_PERTURB_SIZE * sizeof(*table_perturb)); index = port_offset & (INET_TABLE_PERTURB_SIZE - 1); offset = READ_ONCE(table_perturb[index]) + (port_offset >> 32); offset %= remaining; /* In first pass we try ports of @low parity. * inet_csk_get_port() does the opposite choice. */ offset &= ~1U; other_parity_scan: port = low + offset; for (i = 0; i < remaining; i += 2, port += 2) { if (unlikely(port >= high)) port -= remaining; if (inet_is_local_reserved_port(net, port)) continue; head = &hinfo->bhash[inet_bhashfn(net, port, hinfo->bhash_size)]; spin_lock_bh(&head->lock); /* Does not bother with rcv_saddr checks, because * the established check is already unique enough. */ inet_bind_bucket_for_each(tb, &head->chain) { if (net_eq(ib_net(tb), net) && tb->port == port) { if (tb->fastreuse >= 0 || tb->fastreuseport >= 0) goto next_port; WARN_ON(hlist_empty(&tb->owners)); if (!check_established(death_row, sk, port, &tw)) goto ok; goto next_port; } } tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, net, head, port); if (!tb) { spin_unlock_bh(&head->lock); return -ENOMEM; } tb->fastreuse = -1; tb->fastreuseport = -1; goto ok; next_port: spin_unlock_bh(&head->lock); cond_resched(); } offset++; if ((offset & 1) && remaining > 1) goto other_parity_scan; return -EADDRNOTAVAIL; ok: /* Here we want to add a little bit of randomness to the next source * port that will be chosen. We use a max() with a random here so that * on low contention the randomness is maximal and on high contention * it may be inexistent. */ i = max_t(int, i, (prandom_u32() & 7) * 2); WRITE_ONCE(table_perturb[index], READ_ONCE(table_perturb[index]) + i + 2); /* Head lock still held and bh's disabled */ inet_bind_hash(sk, tb, port); if (sk_unhashed(sk)) { inet_sk(sk)->inet_sport = htons(port); inet_ehash_nolisten(sk, (struct sock *)tw, NULL); } if (tw) inet_twsk_bind_unhash(tw, hinfo); spin_unlock(&head->lock); if (tw) inet_twsk_deschedule_put(tw); local_bh_enable(); return 0; } /* * Bind a port for a connect operation and hash it. */ int inet_hash_connect(struct inet_timewait_death_row *death_row, struct sock *sk) { u64 port_offset = 0; if (!inet_sk(sk)->inet_num) port_offset = inet_sk_port_offset(sk); return __inet_hash_connect(death_row, sk, port_offset, __inet_check_established); } EXPORT_SYMBOL_GPL(inet_hash_connect); void inet_hashinfo_init(struct inet_hashinfo *h) { int i; for (i = 0; i < INET_LHTABLE_SIZE; i++) { spin_lock_init(&h->listening_hash[i].lock); INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head, i + LISTENING_NULLS_BASE); h->listening_hash[i].count = 0; } h->lhash2 = NULL; } EXPORT_SYMBOL_GPL(inet_hashinfo_init); void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name, unsigned long numentries, int scale, unsigned long low_limit, unsigned long high_limit) { unsigned int i; h->lhash2 = alloc_large_system_hash(name, sizeof(*h->lhash2), numentries, scale, 0, NULL, &h->lhash2_mask, low_limit, high_limit); for (i = 0; i <= h->lhash2_mask; i++) { spin_lock_init(&h->lhash2[i].lock); INIT_HLIST_HEAD(&h->lhash2[i].head); h->lhash2[i].count = 0; } /* this one is used for source ports of outgoing connections */ table_perturb = kmalloc_array(INET_TABLE_PERTURB_SIZE, sizeof(*table_perturb), GFP_KERNEL); if (!table_perturb) panic("TCP: failed to alloc table_perturb"); } int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo) { unsigned int locksz = sizeof(spinlock_t); unsigned int i, nblocks = 1; if (locksz != 0) { /* allocate 2 cache lines or at least one spinlock per cpu */ nblocks = max(2U * L1_CACHE_BYTES / locksz, 1U); nblocks = roundup_pow_of_two(nblocks * num_possible_cpus()); /* no more locks than number of hash buckets */ nblocks = min(nblocks, hashinfo->ehash_mask + 1); hashinfo->ehash_locks = kvmalloc_array(nblocks, locksz, GFP_KERNEL); if (!hashinfo->ehash_locks) return -ENOMEM; for (i = 0; i < nblocks; i++) spin_lock_init(&hashinfo->ehash_locks[i]); } hashinfo->ehash_locks_mask = nblocks - 1; return 0; } EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc);