inet6_hashtables.h

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/*
 * 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;

/* I have no idea if this is a good hash for v6 or not. -DaveM */
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 = (lport ^ (__force u16)fport);

    return jhash_3words((__force u32)laddr->s6_addr32[3],
                (__force u32)faddr->s6_addr32[3],
                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 *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, 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 */