08dcdbf6a7
It looks like its possible to open thousands of TCP IPv6 sessions on a server, all landing in a single slot of TCP hash table. Incoming packets have to lookup sockets in a very long list. We should hash all bits from foreign IPv6 addresses, using a salt and hash mix, not a simple XOR. inet6_ehashfn() can also separately use the ports, instead of xoring them. Reported-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
118 lines
3.5 KiB
C
118 lines
3.5 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#ifndef _INET6_HASHTABLES_H
|
|
#define _INET6_HASHTABLES_H
|
|
|
|
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
#include <linux/in6.h>
|
|
#include <linux/ipv6.h>
|
|
#include <linux/types.h>
|
|
#include <linux/jhash.h>
|
|
|
|
#include <net/inet_sock.h>
|
|
|
|
#include <net/ipv6.h>
|
|
#include <net/netns/hash.h>
|
|
|
|
struct inet_hashinfo;
|
|
|
|
static inline unsigned int inet6_ehashfn(struct net *net,
|
|
const struct in6_addr *laddr, const u16 lport,
|
|
const struct in6_addr *faddr, const __be16 fport)
|
|
{
|
|
u32 ports = (((u32)lport) << 16) | (__force u32)fport;
|
|
|
|
return jhash_3words((__force u32)laddr->s6_addr32[3],
|
|
ipv6_addr_jhash(faddr),
|
|
ports,
|
|
inet_ehash_secret + net_hash_mix(net));
|
|
}
|
|
|
|
static inline int inet6_sk_ehashfn(const struct sock *sk)
|
|
{
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
const struct ipv6_pinfo *np = inet6_sk(sk);
|
|
const struct in6_addr *laddr = &np->rcv_saddr;
|
|
const struct in6_addr *faddr = &np->daddr;
|
|
const __u16 lport = inet->inet_num;
|
|
const __be16 fport = inet->inet_dport;
|
|
struct net *net = sock_net(sk);
|
|
|
|
return inet6_ehashfn(net, laddr, lport, faddr, fport);
|
|
}
|
|
|
|
extern int __inet6_hash(struct sock *sk, struct inet_timewait_sock *twp);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
extern 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);
|
|
|
|
extern struct sock *inet6_lookup_listener(struct net *net,
|
|
struct inet_hashinfo *hashinfo,
|
|
const struct in6_addr *saddr,
|
|
const __be16 sport,
|
|
const struct in6_addr *daddr,
|
|
const unsigned short hnum,
|
|
const int dif);
|
|
|
|
static inline struct sock *__inet6_lookup(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)
|
|
{
|
|
struct sock *sk = __inet6_lookup_established(net, hashinfo, saddr,
|
|
sport, daddr, hnum, dif);
|
|
if (sk)
|
|
return sk;
|
|
|
|
return inet6_lookup_listener(net, hashinfo, saddr, sport,
|
|
daddr, hnum, dif);
|
|
}
|
|
|
|
static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo,
|
|
struct sk_buff *skb,
|
|
const __be16 sport,
|
|
const __be16 dport)
|
|
{
|
|
struct sock *sk = skb_steal_sock(skb);
|
|
|
|
if (sk)
|
|
return sk;
|
|
|
|
return __inet6_lookup(dev_net(skb_dst(skb)->dev), hashinfo,
|
|
&ipv6_hdr(skb)->saddr, sport,
|
|
&ipv6_hdr(skb)->daddr, ntohs(dport),
|
|
inet6_iif(skb));
|
|
}
|
|
|
|
extern struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
|
|
const struct in6_addr *saddr, const __be16 sport,
|
|
const struct in6_addr *daddr, const __be16 dport,
|
|
const int dif);
|
|
#endif /* IS_ENABLED(CONFIG_IPV6) */
|
|
#endif /* _INET6_HASHTABLES_H */
|