1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Authors: Lotsa people, from code originally in tcp 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 #ifndef _INET6_HASHTABLES_H 15 #define _INET6_HASHTABLES_H 16 17 #include <linux/config.h> 18 19 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) 20 #include <linux/in6.h> 21 #include <linux/ipv6.h> 22 #include <linux/types.h> 23 24 #include <net/ipv6.h> 25 26 struct inet_hashinfo; 27 28 /* I have no idea if this is a good hash for v6 or not. -DaveM */ 29 static inline unsigned int inet6_ehashfn(const struct in6_addr *laddr, const u16 lport, 30 const struct in6_addr *faddr, const u16 fport) 31 { 32 unsigned int hashent = (lport ^ fport); 33 34 hashent ^= (laddr->s6_addr32[3] ^ faddr->s6_addr32[3]); 35 hashent ^= hashent >> 16; 36 hashent ^= hashent >> 8; 37 return hashent; 38 } 39 40 static inline int inet6_sk_ehashfn(const struct sock *sk) 41 { 42 const struct inet_sock *inet = inet_sk(sk); 43 const struct ipv6_pinfo *np = inet6_sk(sk); 44 const struct in6_addr *laddr = &np->rcv_saddr; 45 const struct in6_addr *faddr = &np->daddr; 46 const __u16 lport = inet->num; 47 const __u16 fport = inet->dport; 48 return inet6_ehashfn(laddr, lport, faddr, fport); 49 } 50 51 /* 52 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so 53 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM 54 * 55 * The sockhash lock must be held as a reader here. 56 */ 57 static inline struct sock * 58 __inet6_lookup_established(struct inet_hashinfo *hashinfo, 59 const struct in6_addr *saddr, 60 const u16 sport, 61 const struct in6_addr *daddr, 62 const u16 hnum, 63 const int dif) 64 { 65 struct sock *sk; 66 const struct hlist_node *node; 67 const __u32 ports = INET_COMBINED_PORTS(sport, hnum); 68 /* Optimize here for direct hit, only listening connections can 69 * have wildcards anyways. 70 */ 71 unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport); 72 struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash); 73 74 prefetch(head->chain.first); 75 read_lock(&head->lock); 76 sk_for_each(sk, node, &head->chain) { 77 /* For IPV6 do the cheaper port and family tests first. */ 78 if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif)) 79 goto hit; /* You sunk my battleship! */ 80 } 81 /* Must check for a TIME_WAIT'er before going to listener hash. */ 82 sk_for_each(sk, node, &(head + hashinfo->ehash_size)->chain) { 83 const struct inet_timewait_sock *tw = inet_twsk(sk); 84 85 if(*((__u32 *)&(tw->tw_dport)) == ports && 86 sk->sk_family == PF_INET6) { 87 const struct tcp6_timewait_sock *tcp6tw = tcp6_twsk(sk); 88 89 if (ipv6_addr_equal(&tcp6tw->tw_v6_daddr, saddr) && 90 ipv6_addr_equal(&tcp6tw->tw_v6_rcv_saddr, daddr) && 91 (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)) 92 goto hit; 93 } 94 } 95 read_unlock(&head->lock); 96 return NULL; 97 98 hit: 99 sock_hold(sk); 100 read_unlock(&head->lock); 101 return sk; 102 } 103 104 extern struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo, 105 const struct in6_addr *daddr, 106 const unsigned short hnum, 107 const int dif); 108 109 static inline struct sock *__inet6_lookup(struct inet_hashinfo *hashinfo, 110 const struct in6_addr *saddr, 111 const u16 sport, 112 const struct in6_addr *daddr, 113 const u16 hnum, 114 const int dif) 115 { 116 struct sock *sk = __inet6_lookup_established(hashinfo, saddr, sport, 117 daddr, hnum, dif); 118 if (sk) 119 return sk; 120 121 return inet6_lookup_listener(hashinfo, daddr, hnum, dif); 122 } 123 124 extern struct sock *inet6_lookup(struct inet_hashinfo *hashinfo, 125 const struct in6_addr *saddr, const u16 sport, 126 const struct in6_addr *daddr, const u16 dport, 127 const int dif); 128 #endif /* defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) */ 129 #endif /* _INET6_HASHTABLES_H */ 130