[IPV6]: Deinline few large functions in inet6 code
[linux-2.6.git] / net / ipv6 / inet6_hashtables.c
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  *              Generic INET6 transport hashtables
7  *
8  * Authors:     Lotsa people, from code originally in tcp, generalised here
9  *              by Arnaldo Carvalho de Melo <acme@mandriva.com>
10  *
11  *      This program is free software; you can redistribute it and/or
12  *      modify it under the terms of the GNU General Public License
13  *      as published by the Free Software Foundation; either version
14  *      2 of the License, or (at your option) any later version.
15  */
16
17 #include <linux/config.h>
18 #include <linux/module.h>
19 #include <linux/random.h>
20
21 #include <net/inet_connection_sock.h>
22 #include <net/inet_hashtables.h>
23 #include <net/inet6_hashtables.h>
24 #include <net/ip.h>
25
26 void __inet6_hash(struct inet_hashinfo *hashinfo,
27                                 struct sock *sk)
28 {
29         struct hlist_head *list;
30         rwlock_t *lock;
31
32         BUG_TRAP(sk_unhashed(sk));
33
34         if (sk->sk_state == TCP_LISTEN) {
35                 list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
36                 lock = &hashinfo->lhash_lock;
37                 inet_listen_wlock(hashinfo);
38         } else {
39                 unsigned int hash;
40                 sk->sk_hash = hash = inet6_sk_ehashfn(sk);
41                 hash &= (hashinfo->ehash_size - 1);
42                 list = &hashinfo->ehash[hash].chain;
43                 lock = &hashinfo->ehash[hash].lock;
44                 write_lock(lock);
45         }
46
47         __sk_add_node(sk, list);
48         sock_prot_inc_use(sk->sk_prot);
49         write_unlock(lock);
50 }
51 EXPORT_SYMBOL(__inet6_hash);
52
53 /*
54  * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
55  * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
56  *
57  * The sockhash lock must be held as a reader here.
58  */
59 struct sock *__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         unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport);
73         struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
74
75         prefetch(head->chain.first);
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, hash, 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 inet6_timewait_sock *tw6 = inet6_twsk(sk);
89
90                         if (ipv6_addr_equal(&tw6->tw_v6_daddr, saddr)   &&
91                             ipv6_addr_equal(&tw6->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 EXPORT_SYMBOL(__inet6_lookup_established);
105
106 struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo,
107                                    const struct in6_addr *daddr,
108                                    const unsigned short hnum, const int dif)
109 {
110         struct sock *sk;
111         const struct hlist_node *node;
112         struct sock *result = NULL;
113         int score, hiscore = 0;
114
115         read_lock(&hashinfo->lhash_lock);
116         sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) {
117                 if (inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) {
118                         const struct ipv6_pinfo *np = inet6_sk(sk);
119                         
120                         score = 1;
121                         if (!ipv6_addr_any(&np->rcv_saddr)) {
122                                 if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
123                                         continue;
124                                 score++;
125                         }
126                         if (sk->sk_bound_dev_if) {
127                                 if (sk->sk_bound_dev_if != dif)
128                                         continue;
129                                 score++;
130                         }
131                         if (score == 3) {
132                                 result = sk;
133                                 break;
134                         }
135                         if (score > hiscore) {
136                                 hiscore = score;
137                                 result = sk;
138                         }
139                 }
140         }
141         if (result)
142                 sock_hold(result);
143         read_unlock(&hashinfo->lhash_lock);
144         return result;
145 }
146
147 EXPORT_SYMBOL_GPL(inet6_lookup_listener);
148
149 struct sock *inet6_lookup(struct inet_hashinfo *hashinfo,
150                           const struct in6_addr *saddr, const u16 sport,
151                           const struct in6_addr *daddr, const u16 dport,
152                           const int dif)
153 {
154         struct sock *sk;
155
156         local_bh_disable();
157         sk = __inet6_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
158         local_bh_enable();
159
160         return sk;
161 }
162
163 EXPORT_SYMBOL_GPL(inet6_lookup);
164
165 static int __inet6_check_established(struct inet_timewait_death_row *death_row,
166                                      struct sock *sk, const __u16 lport,
167                                      struct inet_timewait_sock **twp)
168 {
169         struct inet_hashinfo *hinfo = death_row->hashinfo;
170         struct inet_sock *inet = inet_sk(sk);
171         const struct ipv6_pinfo *np = inet6_sk(sk);
172         const struct in6_addr *daddr = &np->rcv_saddr;
173         const struct in6_addr *saddr = &np->daddr;
174         const int dif = sk->sk_bound_dev_if;
175         const u32 ports = INET_COMBINED_PORTS(inet->dport, lport);
176         const unsigned int hash = inet6_ehashfn(daddr, inet->num, saddr,
177                                                 inet->dport);
178         struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
179         struct sock *sk2;
180         const struct hlist_node *node;
181         struct inet_timewait_sock *tw;
182
183         prefetch(head->chain.first);
184         write_lock(&head->lock);
185
186         /* Check TIME-WAIT sockets first. */
187         sk_for_each(sk2, node, &(head + hinfo->ehash_size)->chain) {
188                 const struct inet6_timewait_sock *tw6 = inet6_twsk(sk2);
189
190                 tw = inet_twsk(sk2);
191
192                 if(*((__u32 *)&(tw->tw_dport)) == ports          &&
193                    sk2->sk_family              == PF_INET6       &&
194                    ipv6_addr_equal(&tw6->tw_v6_daddr, saddr)     &&
195                    ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr) &&
196                    sk2->sk_bound_dev_if == sk->sk_bound_dev_if) {
197                         if (twsk_unique(sk, sk2, twp))
198                                 goto unique;
199                         else
200                                 goto not_unique;
201                 }
202         }
203         tw = NULL;
204
205         /* And established part... */
206         sk_for_each(sk2, node, &head->chain) {
207                 if (INET6_MATCH(sk2, hash, saddr, daddr, ports, dif))
208                         goto not_unique;
209         }
210
211 unique:
212         /* Must record num and sport now. Otherwise we will see
213          * in hash table socket with a funny identity. */
214         inet->num = lport;
215         inet->sport = htons(lport);
216         BUG_TRAP(sk_unhashed(sk));
217         __sk_add_node(sk, &head->chain);
218         sk->sk_hash = hash;
219         sock_prot_inc_use(sk->sk_prot);
220         write_unlock(&head->lock);
221
222         if (twp != NULL) {
223                 *twp = tw;
224                 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
225         } else if (tw != NULL) {
226                 /* Silly. Should hash-dance instead... */
227                 inet_twsk_deschedule(tw, death_row);
228                 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
229
230                 inet_twsk_put(tw);
231         }
232         return 0;
233
234 not_unique:
235         write_unlock(&head->lock);
236         return -EADDRNOTAVAIL;
237 }
238
239 static inline u32 inet6_sk_port_offset(const struct sock *sk)
240 {
241         const struct inet_sock *inet = inet_sk(sk);
242         const struct ipv6_pinfo *np = inet6_sk(sk);
243         return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32,
244                                           np->daddr.s6_addr32,
245                                           inet->dport);
246 }
247
248 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
249                        struct sock *sk)
250 {
251         struct inet_hashinfo *hinfo = death_row->hashinfo;
252         const unsigned short snum = inet_sk(sk)->num;
253         struct inet_bind_hashbucket *head;
254         struct inet_bind_bucket *tb;
255         int ret;
256
257         if (snum == 0) {
258                 const int low = sysctl_local_port_range[0];
259                 const int high = sysctl_local_port_range[1];
260                 const int range = high - low;
261                 int i, port;
262                 static u32 hint;
263                 const u32 offset = hint + inet6_sk_port_offset(sk);
264                 struct hlist_node *node;
265                 struct inet_timewait_sock *tw = NULL;
266
267                 local_bh_disable();
268                 for (i = 1; i <= range; i++) {
269                         port = low + (i + offset) % range;
270                         head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)];
271                         spin_lock(&head->lock);
272
273                         /* Does not bother with rcv_saddr checks,
274                          * because the established check is already
275                          * unique enough.
276                          */
277                         inet_bind_bucket_for_each(tb, node, &head->chain) {
278                                 if (tb->port == port) {
279                                         BUG_TRAP(!hlist_empty(&tb->owners));
280                                         if (tb->fastreuse >= 0)
281                                                 goto next_port;
282                                         if (!__inet6_check_established(death_row,
283                                                                        sk, port,
284                                                                        &tw))
285                                                 goto ok;
286                                         goto next_port;
287                                 }
288                         }
289
290                         tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
291                                                      head, port);
292                         if (!tb) {
293                                 spin_unlock(&head->lock);
294                                 break;
295                         }
296                         tb->fastreuse = -1;
297                         goto ok;
298
299                 next_port:
300                         spin_unlock(&head->lock);
301                 }
302                 local_bh_enable();
303
304                 return -EADDRNOTAVAIL;
305
306 ok:
307                 hint += i;
308
309                 /* Head lock still held and bh's disabled */
310                 inet_bind_hash(sk, tb, port);
311                 if (sk_unhashed(sk)) {
312                         inet_sk(sk)->sport = htons(port);
313                         __inet6_hash(hinfo, sk);
314                 }
315                 spin_unlock(&head->lock);
316
317                 if (tw) {
318                         inet_twsk_deschedule(tw, death_row);
319                         inet_twsk_put(tw);
320                 }
321
322                 ret = 0;
323                 goto out;
324         }
325
326         head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)];
327         tb   = inet_csk(sk)->icsk_bind_hash;
328         spin_lock_bh(&head->lock);
329
330         if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) {
331                 __inet6_hash(hinfo, sk);
332                 spin_unlock_bh(&head->lock);
333                 return 0;
334         } else {
335                 spin_unlock(&head->lock);
336                 /* No definite answer... Walk to established hash table */
337                 ret = __inet6_check_established(death_row, sk, snum, NULL);
338 out:
339                 local_bh_enable();
340                 return ret;
341         }
342 }
343
344 EXPORT_SYMBOL_GPL(inet6_hash_connect);