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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Generic INET6 transport hashtables
8 *
9 * Authors: Lotsa people, from code originally in tcp, generalised here
10 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
11 */
12
13#include <linux/module.h>
14#include <linux/random.h>
15
16#include <net/addrconf.h>
17#include <net/hotdata.h>
18#include <net/inet_connection_sock.h>
19#include <net/inet_hashtables.h>
20#include <net/inet6_hashtables.h>
21#include <net/secure_seq.h>
22#include <net/ip.h>
23#include <net/sock_reuseport.h>
24#include <net/tcp.h>
25
26u32 inet6_ehashfn(const struct net *net,
27 const struct in6_addr *laddr, const u16 lport,
28 const struct in6_addr *faddr, const __be16 fport)
29{
30 u32 lhash, fhash;
31
32 net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
33 net_get_random_once(&tcp_ipv6_hash_secret, sizeof(tcp_ipv6_hash_secret));
34
35 lhash = (__force u32)laddr->s6_addr32[3];
36 fhash = __ipv6_addr_jhash(faddr, tcp_ipv6_hash_secret);
37
38 return __inet6_ehashfn(lhash, lport, fhash, fport,
39 inet6_ehash_secret + net_hash_mix(net));
40}
41EXPORT_SYMBOL_GPL(inet6_ehashfn);
42
43/*
44 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
45 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
46 *
47 * The sockhash lock must be held as a reader here.
48 */
49struct sock *__inet6_lookup_established(const struct net *net,
50 struct inet_hashinfo *hashinfo,
51 const struct in6_addr *saddr,
52 const __be16 sport,
53 const struct in6_addr *daddr,
54 const u16 hnum,
55 const int dif, const int sdif)
56{
57 struct sock *sk;
58 const struct hlist_nulls_node *node;
59 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
60 /* Optimize here for direct hit, only listening connections can
61 * have wildcards anyways.
62 */
63 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
64 unsigned int slot = hash & hashinfo->ehash_mask;
65 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
66
67
68begin:
69 sk_nulls_for_each_rcu(sk, node, &head->chain) {
70 if (sk->sk_hash != hash)
71 continue;
72 if (!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
73 continue;
74 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
75 goto out;
76
77 if (unlikely(!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))) {
78 sock_gen_put(sk);
79 goto begin;
80 }
81 goto found;
82 }
83 if (get_nulls_value(node) != slot)
84 goto begin;
85out:
86 sk = NULL;
87found:
88 return sk;
89}
90EXPORT_SYMBOL(__inet6_lookup_established);
91
92static inline int compute_score(struct sock *sk, const struct net *net,
93 const unsigned short hnum,
94 const struct in6_addr *daddr,
95 const int dif, const int sdif)
96{
97 int score = -1;
98
99 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
100 sk->sk_family == PF_INET6) {
101 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
102 return -1;
103
104 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
105 return -1;
106
107 score = sk->sk_bound_dev_if ? 2 : 1;
108 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
109 score++;
110 }
111 return score;
112}
113
114/**
115 * inet6_lookup_reuseport() - execute reuseport logic on AF_INET6 socket if necessary.
116 * @net: network namespace.
117 * @sk: AF_INET6 socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
118 * @skb: context for a potential SK_REUSEPORT program.
119 * @doff: header offset.
120 * @saddr: source address.
121 * @sport: source port.
122 * @daddr: destination address.
123 * @hnum: destination port in host byte order.
124 * @ehashfn: hash function used to generate the fallback hash.
125 *
126 * Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
127 * the selected sock or an error.
128 */
129struct sock *inet6_lookup_reuseport(const struct net *net, struct sock *sk,
130 struct sk_buff *skb, int doff,
131 const struct in6_addr *saddr,
132 __be16 sport,
133 const struct in6_addr *daddr,
134 unsigned short hnum,
135 inet6_ehashfn_t *ehashfn)
136{
137 struct sock *reuse_sk = NULL;
138 u32 phash;
139
140 if (sk->sk_reuseport) {
141 phash = INDIRECT_CALL_INET(ehashfn, udp6_ehashfn, inet6_ehashfn,
142 net, daddr, hnum, saddr, sport);
143 reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
144 }
145 return reuse_sk;
146}
147EXPORT_SYMBOL_GPL(inet6_lookup_reuseport);
148
149/* called with rcu_read_lock() */
150static struct sock *inet6_lhash2_lookup(const struct net *net,
151 struct inet_listen_hashbucket *ilb2,
152 struct sk_buff *skb, int doff,
153 const struct in6_addr *saddr,
154 const __be16 sport, const struct in6_addr *daddr,
155 const unsigned short hnum, const int dif, const int sdif)
156{
157 struct sock *sk, *result = NULL;
158 struct hlist_nulls_node *node;
159 int score, hiscore = 0;
160
161 sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
162 score = compute_score(sk, net, hnum, daddr, dif, sdif);
163 if (score > hiscore) {
164 result = inet6_lookup_reuseport(net, sk, skb, doff,
165 saddr, sport, daddr, hnum, inet6_ehashfn);
166 if (result)
167 return result;
168
169 result = sk;
170 hiscore = score;
171 }
172 }
173
174 return result;
175}
176
177struct sock *inet6_lookup_run_sk_lookup(const struct net *net,
178 int protocol,
179 struct sk_buff *skb, int doff,
180 const struct in6_addr *saddr,
181 const __be16 sport,
182 const struct in6_addr *daddr,
183 const u16 hnum, const int dif,
184 inet6_ehashfn_t *ehashfn)
185{
186 struct sock *sk, *reuse_sk;
187 bool no_reuseport;
188
189 no_reuseport = bpf_sk_lookup_run_v6(net, protocol, saddr, sport,
190 daddr, hnum, dif, &sk);
191 if (no_reuseport || IS_ERR_OR_NULL(sk))
192 return sk;
193
194 reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
195 saddr, sport, daddr, hnum, ehashfn);
196 if (reuse_sk)
197 sk = reuse_sk;
198 return sk;
199}
200EXPORT_SYMBOL_GPL(inet6_lookup_run_sk_lookup);
201
202struct sock *inet6_lookup_listener(const struct net *net,
203 struct inet_hashinfo *hashinfo,
204 struct sk_buff *skb, int doff,
205 const struct in6_addr *saddr,
206 const __be16 sport, const struct in6_addr *daddr,
207 const unsigned short hnum, const int dif, const int sdif)
208{
209 struct inet_listen_hashbucket *ilb2;
210 struct sock *result = NULL;
211 unsigned int hash2;
212
213 /* Lookup redirect from BPF */
214 if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
215 hashinfo == net->ipv4.tcp_death_row.hashinfo) {
216 result = inet6_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
217 saddr, sport, daddr, hnum, dif,
218 inet6_ehashfn);
219 if (result)
220 goto done;
221 }
222
223 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
224 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
225
226 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
227 saddr, sport, daddr, hnum,
228 dif, sdif);
229 if (result)
230 goto done;
231
232 /* Lookup lhash2 with in6addr_any */
233 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
234 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
235
236 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
237 saddr, sport, &in6addr_any, hnum,
238 dif, sdif);
239done:
240 if (IS_ERR(result))
241 return NULL;
242 return result;
243}
244EXPORT_SYMBOL_GPL(inet6_lookup_listener);
245
246struct sock *inet6_lookup(const struct net *net,
247 struct inet_hashinfo *hashinfo,
248 struct sk_buff *skb, int doff,
249 const struct in6_addr *saddr, const __be16 sport,
250 const struct in6_addr *daddr, const __be16 dport,
251 const int dif)
252{
253 struct sock *sk;
254 bool refcounted;
255
256 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
257 ntohs(dport), dif, 0, &refcounted);
258 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
259 sk = NULL;
260 return sk;
261}
262EXPORT_SYMBOL_GPL(inet6_lookup);
263
264static int __inet6_check_established(struct inet_timewait_death_row *death_row,
265 struct sock *sk, const __u16 lport,
266 struct inet_timewait_sock **twp)
267{
268 struct inet_hashinfo *hinfo = death_row->hashinfo;
269 struct inet_sock *inet = inet_sk(sk);
270 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
271 const struct in6_addr *saddr = &sk->sk_v6_daddr;
272 const int dif = sk->sk_bound_dev_if;
273 struct net *net = sock_net(sk);
274 const int sdif = l3mdev_master_ifindex_by_index(net, dif);
275 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
276 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
277 inet->inet_dport);
278 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
279 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
280 struct sock *sk2;
281 const struct hlist_nulls_node *node;
282 struct inet_timewait_sock *tw = NULL;
283
284 spin_lock(lock);
285
286 sk_nulls_for_each(sk2, node, &head->chain) {
287 if (sk2->sk_hash != hash)
288 continue;
289
290 if (likely(inet6_match(net, sk2, saddr, daddr, ports,
291 dif, sdif))) {
292 if (sk2->sk_state == TCP_TIME_WAIT) {
293 tw = inet_twsk(sk2);
294 if (sk->sk_protocol == IPPROTO_TCP &&
295 tcp_twsk_unique(sk, sk2, twp))
296 break;
297 }
298 goto not_unique;
299 }
300 }
301
302 /* Must record num and sport now. Otherwise we will see
303 * in hash table socket with a funny identity.
304 */
305 inet->inet_num = lport;
306 inet->inet_sport = htons(lport);
307 sk->sk_hash = hash;
308 WARN_ON(!sk_unhashed(sk));
309 __sk_nulls_add_node_rcu(sk, &head->chain);
310 if (tw) {
311 sk_nulls_del_node_init_rcu((struct sock *)tw);
312 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
313 }
314 spin_unlock(lock);
315 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
316
317 if (twp) {
318 *twp = tw;
319 } else if (tw) {
320 /* Silly. Should hash-dance instead... */
321 inet_twsk_deschedule_put(tw);
322 }
323 return 0;
324
325not_unique:
326 spin_unlock(lock);
327 return -EADDRNOTAVAIL;
328}
329
330static u64 inet6_sk_port_offset(const struct sock *sk)
331{
332 const struct inet_sock *inet = inet_sk(sk);
333
334 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
335 sk->sk_v6_daddr.s6_addr32,
336 inet->inet_dport);
337}
338
339int inet6_hash_connect(struct inet_timewait_death_row *death_row,
340 struct sock *sk)
341{
342 u64 port_offset = 0;
343
344 if (!inet_sk(sk)->inet_num)
345 port_offset = inet6_sk_port_offset(sk);
346 return __inet_hash_connect(death_row, sk, port_offset,
347 __inet6_check_established);
348}
349EXPORT_SYMBOL_GPL(inet6_hash_connect);
350
351int inet6_hash(struct sock *sk)
352{
353 int err = 0;
354
355 if (sk->sk_state != TCP_CLOSE)
356 err = __inet_hash(sk, NULL);
357
358 return err;
359}
360EXPORT_SYMBOL_GPL(inet6_hash);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Generic INET6 transport hashtables
8 *
9 * Authors: Lotsa people, from code originally in tcp, generalised here
10 * by Arnaldo Carvalho de Melo <acme@mandriva.com>
11 */
12
13#include <linux/module.h>
14#include <linux/random.h>
15
16#include <net/addrconf.h>
17#include <net/inet_connection_sock.h>
18#include <net/inet_hashtables.h>
19#include <net/inet6_hashtables.h>
20#include <net/secure_seq.h>
21#include <net/ip.h>
22#include <net/sock_reuseport.h>
23
24u32 inet6_ehashfn(const struct net *net,
25 const struct in6_addr *laddr, const u16 lport,
26 const struct in6_addr *faddr, const __be16 fport)
27{
28 static u32 inet6_ehash_secret __read_mostly;
29 static u32 ipv6_hash_secret __read_mostly;
30
31 u32 lhash, fhash;
32
33 net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
34 net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
35
36 lhash = (__force u32)laddr->s6_addr32[3];
37 fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);
38
39 return __inet6_ehashfn(lhash, lport, fhash, fport,
40 inet6_ehash_secret + net_hash_mix(net));
41}
42
43/*
44 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
45 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
46 *
47 * The sockhash lock must be held as a reader here.
48 */
49struct sock *__inet6_lookup_established(struct net *net,
50 struct inet_hashinfo *hashinfo,
51 const struct in6_addr *saddr,
52 const __be16 sport,
53 const struct in6_addr *daddr,
54 const u16 hnum,
55 const int dif, const int sdif)
56{
57 struct sock *sk;
58 const struct hlist_nulls_node *node;
59 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
60 /* Optimize here for direct hit, only listening connections can
61 * have wildcards anyways.
62 */
63 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
64 unsigned int slot = hash & hashinfo->ehash_mask;
65 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
66
67
68begin:
69 sk_nulls_for_each_rcu(sk, node, &head->chain) {
70 if (sk->sk_hash != hash)
71 continue;
72 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))
73 continue;
74 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
75 goto out;
76
77 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif, sdif))) {
78 sock_gen_put(sk);
79 goto begin;
80 }
81 goto found;
82 }
83 if (get_nulls_value(node) != slot)
84 goto begin;
85out:
86 sk = NULL;
87found:
88 return sk;
89}
90EXPORT_SYMBOL(__inet6_lookup_established);
91
92static inline int compute_score(struct sock *sk, struct net *net,
93 const unsigned short hnum,
94 const struct in6_addr *daddr,
95 const int dif, const int sdif, bool exact_dif)
96{
97 int score = -1;
98
99 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
100 sk->sk_family == PF_INET6) {
101 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
102 return -1;
103
104 if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
105 return -1;
106
107 score = 1;
108 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
109 score++;
110 }
111 return score;
112}
113
114/* called with rcu_read_lock() */
115static struct sock *inet6_lhash2_lookup(struct net *net,
116 struct inet_listen_hashbucket *ilb2,
117 struct sk_buff *skb, int doff,
118 const struct in6_addr *saddr,
119 const __be16 sport, const struct in6_addr *daddr,
120 const unsigned short hnum, const int dif, const int sdif)
121{
122 bool exact_dif = inet6_exact_dif_match(net, skb);
123 struct inet_connection_sock *icsk;
124 struct sock *sk, *result = NULL;
125 int score, hiscore = 0;
126 u32 phash = 0;
127
128 inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
129 sk = (struct sock *)icsk;
130 score = compute_score(sk, net, hnum, daddr, dif, sdif,
131 exact_dif);
132 if (score > hiscore) {
133 if (sk->sk_reuseport) {
134 phash = inet6_ehashfn(net, daddr, hnum,
135 saddr, sport);
136 result = reuseport_select_sock(sk, phash,
137 skb, doff);
138 if (result)
139 return result;
140 }
141 result = sk;
142 hiscore = score;
143 }
144 }
145
146 return result;
147}
148
149struct sock *inet6_lookup_listener(struct net *net,
150 struct inet_hashinfo *hashinfo,
151 struct sk_buff *skb, int doff,
152 const struct in6_addr *saddr,
153 const __be16 sport, const struct in6_addr *daddr,
154 const unsigned short hnum, const int dif, const int sdif)
155{
156 struct inet_listen_hashbucket *ilb2;
157 struct sock *result = NULL;
158 unsigned int hash2;
159
160 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
161 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
162
163 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
164 saddr, sport, daddr, hnum,
165 dif, sdif);
166 if (result)
167 goto done;
168
169 /* Lookup lhash2 with in6addr_any */
170 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
171 ilb2 = inet_lhash2_bucket(hashinfo, hash2);
172
173 result = inet6_lhash2_lookup(net, ilb2, skb, doff,
174 saddr, sport, &in6addr_any, hnum,
175 dif, sdif);
176done:
177 if (IS_ERR(result))
178 return NULL;
179 return result;
180}
181EXPORT_SYMBOL_GPL(inet6_lookup_listener);
182
183struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
184 struct sk_buff *skb, int doff,
185 const struct in6_addr *saddr, const __be16 sport,
186 const struct in6_addr *daddr, const __be16 dport,
187 const int dif)
188{
189 struct sock *sk;
190 bool refcounted;
191
192 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
193 ntohs(dport), dif, 0, &refcounted);
194 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
195 sk = NULL;
196 return sk;
197}
198EXPORT_SYMBOL_GPL(inet6_lookup);
199
200static int __inet6_check_established(struct inet_timewait_death_row *death_row,
201 struct sock *sk, const __u16 lport,
202 struct inet_timewait_sock **twp)
203{
204 struct inet_hashinfo *hinfo = death_row->hashinfo;
205 struct inet_sock *inet = inet_sk(sk);
206 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
207 const struct in6_addr *saddr = &sk->sk_v6_daddr;
208 const int dif = sk->sk_bound_dev_if;
209 struct net *net = sock_net(sk);
210 const int sdif = l3mdev_master_ifindex_by_index(net, dif);
211 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
212 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
213 inet->inet_dport);
214 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
215 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
216 struct sock *sk2;
217 const struct hlist_nulls_node *node;
218 struct inet_timewait_sock *tw = NULL;
219
220 spin_lock(lock);
221
222 sk_nulls_for_each(sk2, node, &head->chain) {
223 if (sk2->sk_hash != hash)
224 continue;
225
226 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports,
227 dif, sdif))) {
228 if (sk2->sk_state == TCP_TIME_WAIT) {
229 tw = inet_twsk(sk2);
230 if (twsk_unique(sk, sk2, twp))
231 break;
232 }
233 goto not_unique;
234 }
235 }
236
237 /* Must record num and sport now. Otherwise we will see
238 * in hash table socket with a funny identity.
239 */
240 inet->inet_num = lport;
241 inet->inet_sport = htons(lport);
242 sk->sk_hash = hash;
243 WARN_ON(!sk_unhashed(sk));
244 __sk_nulls_add_node_rcu(sk, &head->chain);
245 if (tw) {
246 sk_nulls_del_node_init_rcu((struct sock *)tw);
247 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
248 }
249 spin_unlock(lock);
250 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
251
252 if (twp) {
253 *twp = tw;
254 } else if (tw) {
255 /* Silly. Should hash-dance instead... */
256 inet_twsk_deschedule_put(tw);
257 }
258 return 0;
259
260not_unique:
261 spin_unlock(lock);
262 return -EADDRNOTAVAIL;
263}
264
265static u32 inet6_sk_port_offset(const struct sock *sk)
266{
267 const struct inet_sock *inet = inet_sk(sk);
268
269 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
270 sk->sk_v6_daddr.s6_addr32,
271 inet->inet_dport);
272}
273
274int inet6_hash_connect(struct inet_timewait_death_row *death_row,
275 struct sock *sk)
276{
277 u32 port_offset = 0;
278
279 if (!inet_sk(sk)->inet_num)
280 port_offset = inet6_sk_port_offset(sk);
281 return __inet_hash_connect(death_row, sk, port_offset,
282 __inet6_check_established);
283}
284EXPORT_SYMBOL_GPL(inet6_hash_connect);
285
286int inet6_hash(struct sock *sk)
287{
288 int err = 0;
289
290 if (sk->sk_state != TCP_CLOSE) {
291 local_bh_disable();
292 err = __inet_hash(sk, NULL);
293 local_bh_enable();
294 }
295
296 return err;
297}
298EXPORT_SYMBOL_GPL(inet6_hash);