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 int inet6_ehashfn(const struct in6_addr *laddr, const u16 lport, 30 const struct in6_addr *faddr, const u16 fport, 31 const int ehash_size) 32 { 33 int hashent = (lport ^ fport); 34 35 hashent ^= (laddr->s6_addr32[3] ^ faddr->s6_addr32[3]); 36 hashent ^= hashent >> 16; 37 hashent ^= hashent >> 8; 38 return (hashent & (ehash_size - 1)); 39 } 40 41 static inline int inet6_sk_ehashfn(const struct sock *sk, const int ehash_size) 42 { 43 const struct inet_sock *inet = inet_sk(sk); 44 const struct ipv6_pinfo *np = inet6_sk(sk); 45 const struct in6_addr *laddr = &np->rcv_saddr; 46 const struct in6_addr *faddr = &np->daddr; 47 const __u16 lport = inet->num; 48 const __u16 fport = inet->dport; 49 return inet6_ehashfn(laddr, lport, faddr, fport, ehash_size); 50 } 51 52 /* 53 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so 54 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM 55 * 56 * The sockhash lock must be held as a reader here. 57 */ 58 static inline struct sock * 59 __inet6_lookup_established(struct inet_hashinfo *hashinfo, 60 const struct in6_addr *saddr, 61 const u16 sport, 62 const struct in6_addr *daddr, 63 const u16 hnum, 64 const int dif) 65 { 66 struct sock *sk; 67 const struct hlist_node *node; 68 const __u32 ports = INET_COMBINED_PORTS(sport, hnum); 69 /* Optimize here for direct hit, only listening connections can 70 * have wildcards anyways. 71 */ 72 const int hash = inet6_ehashfn(daddr, hnum, saddr, sport, 73 hashinfo->ehash_size); 74 struct inet_ehash_bucket *head = &hashinfo->ehash[hash]; 75 76 read_lock(&head->lock); 77 sk_for_each(sk, node, &head->chain) { 78 /* For IPV6 do the cheaper port and family tests first. */ 79 if (INET6_MATCH(sk, saddr, daddr, ports, dif)) 80 goto hit; /* You sunk my battleship! */ 81 } 82 /* Must check for a TIME_WAIT'er before going to listener hash. */ 83 sk_for_each(sk, node, &(head + hashinfo->ehash_size)->chain) { 84 const struct inet_timewait_sock *tw = inet_twsk(sk); 85 86 if(*((__u32 *)&(tw->tw_dport)) == ports && 87 sk->sk_family == PF_INET6) { 88 const struct tcp6_timewait_sock *tcp6tw = tcp6_twsk(sk); 89 90 if (ipv6_addr_equal(&tcp6tw->tw_v6_daddr, saddr) && 91 ipv6_addr_equal(&tcp6tw->tw_v6_rcv_saddr, daddr) && 92 (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)) 93 goto hit; 94 } 95 } 96 read_unlock(&head->lock); 97 return NULL; 98 99 hit: 100 sock_hold(sk); 101 read_unlock(&head->lock); 102 return sk; 103 } 104 105 extern struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo, 106 const struct in6_addr *daddr, 107 const unsigned short hnum, 108 const int dif); 109 110 static inline struct sock *__inet6_lookup(struct inet_hashinfo *hashinfo, 111 const struct in6_addr *saddr, 112 const u16 sport, 113 const struct in6_addr *daddr, 114 const u16 hnum, 115 const int dif) 116 { 117 struct sock *sk = __inet6_lookup_established(hashinfo, saddr, sport, 118 daddr, hnum, dif); 119 if (sk) 120 return sk; 121 122 return inet6_lookup_listener(hashinfo, daddr, hnum, dif); 123 } 124 125 extern struct sock *inet6_lookup(struct inet_hashinfo *hashinfo, 126 const struct in6_addr *saddr, const u16 sport, 127 const struct in6_addr *daddr, const u16 dport, 128 const int dif); 129 #endif /* defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) */ 130 #endif /* _INET6_HASHTABLES_H */ 131