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![Joanne Koong](/assets/img/avatar_default.png)
This reverts: commitd5a42de8bd
("net: Add a second bind table hashed by port and address") commit538aaf9b23
("selftests: Add test for timing a bind request to a port with a populated bhash entry") Link: https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/ There are a few things that need to be fixed here: * Updating bhash2 in cases where the socket's rcv saddr changes * Adding bhash2 hashbucket locks Links to syzbot reports: https://lore.kernel.org/netdev/00000000000022208805e0df247a@google.com/ https://lore.kernel.org/netdev/0000000000003f33bc05dfaf44fe@google.com/ Fixes:d5a42de8bd
("net: Add a second bind table hashed by port and address") Reported-by: syzbot+015d756bbd1f8b5c8f09@syzkaller.appspotmail.com Reported-by: syzbot+98fd2d1422063b0f8c44@syzkaller.appspotmail.com Reported-by: syzbot+0a847a982613c6438fba@syzkaller.appspotmail.com Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20220615193213.2419568-1-joannelkoong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
904 lines
24 KiB
C
904 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Generic INET transport hashtables
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*
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* Authors: Lotsa people, from code originally in tcp
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*/
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/wait.h>
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#include <linux/vmalloc.h>
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#include <linux/memblock.h>
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#include <net/addrconf.h>
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#include <net/inet_connection_sock.h>
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#include <net/inet_hashtables.h>
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#if IS_ENABLED(CONFIG_IPV6)
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#include <net/inet6_hashtables.h>
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#endif
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#include <net/secure_seq.h>
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#include <net/ip.h>
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#include <net/tcp.h>
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#include <net/sock_reuseport.h>
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static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
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const __u16 lport, const __be32 faddr,
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const __be16 fport)
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{
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static u32 inet_ehash_secret __read_mostly;
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net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
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return __inet_ehashfn(laddr, lport, faddr, fport,
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inet_ehash_secret + net_hash_mix(net));
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}
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/* This function handles inet_sock, but also timewait and request sockets
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* for IPv4/IPv6.
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*/
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static u32 sk_ehashfn(const struct sock *sk)
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{
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#if IS_ENABLED(CONFIG_IPV6)
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if (sk->sk_family == AF_INET6 &&
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!ipv6_addr_v4mapped(&sk->sk_v6_daddr))
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return inet6_ehashfn(sock_net(sk),
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&sk->sk_v6_rcv_saddr, sk->sk_num,
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&sk->sk_v6_daddr, sk->sk_dport);
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#endif
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return inet_ehashfn(sock_net(sk),
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sk->sk_rcv_saddr, sk->sk_num,
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sk->sk_daddr, sk->sk_dport);
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}
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/*
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* Allocate and initialize a new local port bind bucket.
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* The bindhash mutex for snum's hash chain must be held here.
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*/
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struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
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struct net *net,
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struct inet_bind_hashbucket *head,
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const unsigned short snum,
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int l3mdev)
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{
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struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
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if (tb) {
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write_pnet(&tb->ib_net, net);
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tb->l3mdev = l3mdev;
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tb->port = snum;
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tb->fastreuse = 0;
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tb->fastreuseport = 0;
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INIT_HLIST_HEAD(&tb->owners);
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hlist_add_head(&tb->node, &head->chain);
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}
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return tb;
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}
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/*
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* Caller must hold hashbucket lock for this tb with local BH disabled
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*/
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void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
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{
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if (hlist_empty(&tb->owners)) {
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__hlist_del(&tb->node);
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kmem_cache_free(cachep, tb);
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}
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}
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void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
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const unsigned short snum)
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{
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inet_sk(sk)->inet_num = snum;
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sk_add_bind_node(sk, &tb->owners);
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inet_csk(sk)->icsk_bind_hash = tb;
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}
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/*
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* Get rid of any references to a local port held by the given sock.
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*/
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static void __inet_put_port(struct sock *sk)
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{
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struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
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const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->inet_num,
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hashinfo->bhash_size);
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struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
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struct inet_bind_bucket *tb;
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spin_lock(&head->lock);
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tb = inet_csk(sk)->icsk_bind_hash;
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__sk_del_bind_node(sk);
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inet_csk(sk)->icsk_bind_hash = NULL;
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inet_sk(sk)->inet_num = 0;
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inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
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spin_unlock(&head->lock);
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}
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void inet_put_port(struct sock *sk)
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{
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local_bh_disable();
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__inet_put_port(sk);
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local_bh_enable();
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}
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EXPORT_SYMBOL(inet_put_port);
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int __inet_inherit_port(const struct sock *sk, struct sock *child)
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{
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struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
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unsigned short port = inet_sk(child)->inet_num;
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const int bhash = inet_bhashfn(sock_net(sk), port,
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table->bhash_size);
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struct inet_bind_hashbucket *head = &table->bhash[bhash];
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struct inet_bind_bucket *tb;
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int l3mdev;
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spin_lock(&head->lock);
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tb = inet_csk(sk)->icsk_bind_hash;
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if (unlikely(!tb)) {
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spin_unlock(&head->lock);
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return -ENOENT;
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}
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if (tb->port != port) {
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l3mdev = inet_sk_bound_l3mdev(sk);
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/* NOTE: using tproxy and redirecting skbs to a proxy
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* on a different listener port breaks the assumption
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* that the listener socket's icsk_bind_hash is the same
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* as that of the child socket. We have to look up or
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* create a new bind bucket for the child here. */
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inet_bind_bucket_for_each(tb, &head->chain) {
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if (net_eq(ib_net(tb), sock_net(sk)) &&
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tb->l3mdev == l3mdev && tb->port == port)
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break;
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}
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if (!tb) {
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tb = inet_bind_bucket_create(table->bind_bucket_cachep,
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sock_net(sk), head, port,
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l3mdev);
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if (!tb) {
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spin_unlock(&head->lock);
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return -ENOMEM;
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}
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}
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inet_csk_update_fastreuse(tb, child);
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}
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inet_bind_hash(child, tb, port);
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spin_unlock(&head->lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(__inet_inherit_port);
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static struct inet_listen_hashbucket *
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inet_lhash2_bucket_sk(struct inet_hashinfo *h, struct sock *sk)
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{
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u32 hash;
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#if IS_ENABLED(CONFIG_IPV6)
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if (sk->sk_family == AF_INET6)
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hash = ipv6_portaddr_hash(sock_net(sk),
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&sk->sk_v6_rcv_saddr,
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inet_sk(sk)->inet_num);
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else
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#endif
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hash = ipv4_portaddr_hash(sock_net(sk),
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inet_sk(sk)->inet_rcv_saddr,
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inet_sk(sk)->inet_num);
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return inet_lhash2_bucket(h, hash);
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}
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static inline int compute_score(struct sock *sk, struct net *net,
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const unsigned short hnum, const __be32 daddr,
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const int dif, const int sdif)
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{
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int score = -1;
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if (net_eq(sock_net(sk), net) && sk->sk_num == hnum &&
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!ipv6_only_sock(sk)) {
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if (sk->sk_rcv_saddr != daddr)
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return -1;
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if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
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return -1;
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score = sk->sk_bound_dev_if ? 2 : 1;
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if (sk->sk_family == PF_INET)
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score++;
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if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
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score++;
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}
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return score;
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}
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static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
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struct sk_buff *skb, int doff,
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__be32 saddr, __be16 sport,
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__be32 daddr, unsigned short hnum)
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{
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struct sock *reuse_sk = NULL;
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u32 phash;
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if (sk->sk_reuseport) {
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phash = inet_ehashfn(net, daddr, hnum, saddr, sport);
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reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
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}
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return reuse_sk;
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}
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/*
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* Here are some nice properties to exploit here. The BSD API
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* does not allow a listening sock to specify the remote port nor the
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* remote address for the connection. So always assume those are both
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* wildcarded during the search since they can never be otherwise.
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*/
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/* called with rcu_read_lock() : No refcount taken on the socket */
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static struct sock *inet_lhash2_lookup(struct net *net,
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struct inet_listen_hashbucket *ilb2,
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struct sk_buff *skb, int doff,
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const __be32 saddr, __be16 sport,
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const __be32 daddr, const unsigned short hnum,
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const int dif, const int sdif)
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{
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struct sock *sk, *result = NULL;
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struct hlist_nulls_node *node;
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int score, hiscore = 0;
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sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
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score = compute_score(sk, net, hnum, daddr, dif, sdif);
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if (score > hiscore) {
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result = lookup_reuseport(net, sk, skb, doff,
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saddr, sport, daddr, hnum);
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if (result)
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return result;
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result = sk;
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hiscore = score;
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}
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}
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return result;
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}
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static inline struct sock *inet_lookup_run_bpf(struct net *net,
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struct inet_hashinfo *hashinfo,
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struct sk_buff *skb, int doff,
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__be32 saddr, __be16 sport,
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__be32 daddr, u16 hnum, const int dif)
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{
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struct sock *sk, *reuse_sk;
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bool no_reuseport;
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if (hashinfo != &tcp_hashinfo)
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return NULL; /* only TCP is supported */
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no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_TCP, saddr, sport,
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daddr, hnum, dif, &sk);
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if (no_reuseport || IS_ERR_OR_NULL(sk))
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return sk;
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reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
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if (reuse_sk)
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sk = reuse_sk;
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return sk;
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}
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struct sock *__inet_lookup_listener(struct net *net,
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struct inet_hashinfo *hashinfo,
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struct sk_buff *skb, int doff,
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const __be32 saddr, __be16 sport,
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const __be32 daddr, const unsigned short hnum,
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const int dif, const int sdif)
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{
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struct inet_listen_hashbucket *ilb2;
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struct sock *result = NULL;
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unsigned int hash2;
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/* Lookup redirect from BPF */
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if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
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result = inet_lookup_run_bpf(net, hashinfo, skb, doff,
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saddr, sport, daddr, hnum, dif);
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if (result)
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goto done;
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}
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hash2 = ipv4_portaddr_hash(net, daddr, hnum);
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ilb2 = inet_lhash2_bucket(hashinfo, hash2);
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result = inet_lhash2_lookup(net, ilb2, skb, doff,
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saddr, sport, daddr, hnum,
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dif, sdif);
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if (result)
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goto done;
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/* Lookup lhash2 with INADDR_ANY */
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hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
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ilb2 = inet_lhash2_bucket(hashinfo, hash2);
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result = inet_lhash2_lookup(net, ilb2, skb, doff,
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saddr, sport, htonl(INADDR_ANY), hnum,
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dif, sdif);
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done:
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if (IS_ERR(result))
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return NULL;
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return result;
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}
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EXPORT_SYMBOL_GPL(__inet_lookup_listener);
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/* All sockets share common refcount, but have different destructors */
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void sock_gen_put(struct sock *sk)
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{
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if (!refcount_dec_and_test(&sk->sk_refcnt))
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return;
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|
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if (sk->sk_state == TCP_TIME_WAIT)
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inet_twsk_free(inet_twsk(sk));
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else if (sk->sk_state == TCP_NEW_SYN_RECV)
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reqsk_free(inet_reqsk(sk));
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else
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sk_free(sk);
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}
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EXPORT_SYMBOL_GPL(sock_gen_put);
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|
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void sock_edemux(struct sk_buff *skb)
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{
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sock_gen_put(skb->sk);
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}
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EXPORT_SYMBOL(sock_edemux);
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|
|
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struct sock *__inet_lookup_established(struct net *net,
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struct inet_hashinfo *hashinfo,
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const __be32 saddr, const __be16 sport,
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const __be32 daddr, const u16 hnum,
|
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const int dif, const int sdif)
|
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{
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INET_ADDR_COOKIE(acookie, saddr, daddr);
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const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
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struct sock *sk;
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const struct hlist_nulls_node *node;
|
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/* Optimize here for direct hit, only listening connections can
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* have wildcards anyways.
|
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*/
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unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
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unsigned int slot = hash & hashinfo->ehash_mask;
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struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
|
|
|
|
begin:
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|
sk_nulls_for_each_rcu(sk, node, &head->chain) {
|
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if (sk->sk_hash != hash)
|
|
continue;
|
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if (likely(inet_match(net, sk, acookie, ports, dif, sdif))) {
|
|
if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
|
|
goto out;
|
|
if (unlikely(!inet_match(net, sk, acookie,
|
|
ports, dif, sdif))) {
|
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sock_gen_put(sk);
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goto begin;
|
|
}
|
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goto found;
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}
|
|
}
|
|
/*
|
|
* 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.
|
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*/
|
|
if (get_nulls_value(node) != slot)
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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(net, sk2, acookie, 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(net, esk, acookie,
|
|
ports, dif, sdif))) {
|
|
return true;
|
|
}
|
|
}
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
else if (sk->sk_family == AF_INET6) {
|
|
if (unlikely(inet6_match(net, esk,
|
|
&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 {
|
|
this_cpu_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 *ilb2;
|
|
int err = 0;
|
|
|
|
if (sk->sk_state != TCP_LISTEN) {
|
|
local_bh_disable();
|
|
inet_ehash_nolisten(sk, osk, NULL);
|
|
local_bh_enable();
|
|
return 0;
|
|
}
|
|
WARN_ON(!sk_unhashed(sk));
|
|
ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
|
|
|
|
spin_lock(&ilb2->lock);
|
|
if (sk->sk_reuseport) {
|
|
err = inet_reuseport_add_sock(sk, ilb2);
|
|
if (err)
|
|
goto unlock;
|
|
}
|
|
if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
|
|
sk->sk_family == AF_INET6)
|
|
__sk_nulls_add_node_tail_rcu(sk, &ilb2->nulls_head);
|
|
else
|
|
__sk_nulls_add_node_rcu(sk, &ilb2->nulls_head);
|
|
sock_set_flag(sk, SOCK_RCU_FREE);
|
|
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
|
|
unlock:
|
|
spin_unlock(&ilb2->lock);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(__inet_hash);
|
|
|
|
int inet_hash(struct sock *sk)
|
|
{
|
|
int err = 0;
|
|
|
|
if (sk->sk_state != TCP_CLOSE)
|
|
err = __inet_hash(sk, NULL);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_hash);
|
|
|
|
void inet_unhash(struct sock *sk)
|
|
{
|
|
struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
|
|
|
|
if (sk_unhashed(sk))
|
|
return;
|
|
|
|
if (sk->sk_state == TCP_LISTEN) {
|
|
struct inet_listen_hashbucket *ilb2;
|
|
|
|
ilb2 = inet_lhash2_bucket_sk(hashinfo, sk);
|
|
/* Don't disable bottom halves while acquiring the lock to
|
|
* avoid circular locking dependency on PREEMPT_RT.
|
|
*/
|
|
spin_lock(&ilb2->lock);
|
|
if (sk_unhashed(sk)) {
|
|
spin_unlock(&ilb2->lock);
|
|
return;
|
|
}
|
|
|
|
if (rcu_access_pointer(sk->sk_reuseport_cb))
|
|
reuseport_stop_listen_sock(sk);
|
|
|
|
__sk_nulls_del_node_init_rcu(sk);
|
|
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
|
|
spin_unlock(&ilb2->lock);
|
|
} else {
|
|
spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
|
|
|
|
spin_lock_bh(lock);
|
|
if (sk_unhashed(sk)) {
|
|
spin_unlock_bh(lock);
|
|
return;
|
|
}
|
|
__sk_nulls_del_node_init_rcu(sk);
|
|
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
|
|
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;
|
|
int l3mdev;
|
|
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;
|
|
}
|
|
|
|
l3mdev = inet_sk_bound_l3mdev(sk);
|
|
|
|
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->l3mdev == l3mdev &&
|
|
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, l3mdev);
|
|
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);
|
|
|
|
static void init_hashinfo_lhash2(struct inet_hashinfo *h)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i <= h->lhash2_mask; i++) {
|
|
spin_lock_init(&h->lhash2[i].lock);
|
|
INIT_HLIST_NULLS_HEAD(&h->lhash2[i].nulls_head,
|
|
i + LISTENING_NULLS_BASE);
|
|
}
|
|
}
|
|
|
|
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)
|
|
{
|
|
h->lhash2 = alloc_large_system_hash(name,
|
|
sizeof(*h->lhash2),
|
|
numentries,
|
|
scale,
|
|
0,
|
|
NULL,
|
|
&h->lhash2_mask,
|
|
low_limit,
|
|
high_limit);
|
|
init_hashinfo_lhash2(h);
|
|
|
|
/* this one is used for source ports of outgoing connections */
|
|
table_perturb = alloc_large_system_hash("Table-perturb",
|
|
sizeof(*table_perturb),
|
|
INET_TABLE_PERTURB_SIZE,
|
|
0, 0, NULL, NULL,
|
|
INET_TABLE_PERTURB_SIZE,
|
|
INET_TABLE_PERTURB_SIZE);
|
|
}
|
|
|
|
int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
|
|
{
|
|
h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
|
|
if (!h->lhash2)
|
|
return -ENOMEM;
|
|
|
|
h->lhash2_mask = INET_LHTABLE_SIZE - 1;
|
|
/* INET_LHTABLE_SIZE must be a power of 2 */
|
|
BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
|
|
|
|
init_hashinfo_lhash2(h);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
|
|
|
|
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);
|