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17#include <linux/module.h>
18#include <linux/random.h>
19
20#include <net/addrconf.h>
21#include <net/inet_connection_sock.h>
22#include <net/inet_hashtables.h>
23#include <net/inet6_hashtables.h>
24#include <net/secure_seq.h>
25#include <net/ip.h>
26#include <net/sock_reuseport.h>
27
28u32 inet6_ehashfn(const struct net *net,
29 const struct in6_addr *laddr, const u16 lport,
30 const struct in6_addr *faddr, const __be16 fport)
31{
32 static u32 inet6_ehash_secret __read_mostly;
33 static u32 ipv6_hash_secret __read_mostly;
34
35 u32 lhash, fhash;
36
37 net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
38 net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
39
40 lhash = (__force u32)laddr->s6_addr32[3];
41 fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret);
42
43 return __inet6_ehashfn(lhash, lport, fhash, fport,
44 inet6_ehash_secret + net_hash_mix(net));
45}
46
47
48
49
50
51
52
53struct sock *__inet6_lookup_established(struct net *net,
54 struct inet_hashinfo *hashinfo,
55 const struct in6_addr *saddr,
56 const __be16 sport,
57 const struct in6_addr *daddr,
58 const u16 hnum,
59 const int dif)
60{
61 struct sock *sk;
62 const struct hlist_nulls_node *node;
63 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
64
65
66
67 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
68 unsigned int slot = hash & hashinfo->ehash_mask;
69 struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
70
71
72begin:
73 sk_nulls_for_each_rcu(sk, node, &head->chain) {
74 if (sk->sk_hash != hash)
75 continue;
76 if (!INET6_MATCH(sk, net, saddr, daddr, ports, dif))
77 continue;
78 if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
79 goto out;
80
81 if (unlikely(!INET6_MATCH(sk, net, saddr, daddr, ports, dif))) {
82 sock_gen_put(sk);
83 goto begin;
84 }
85 goto found;
86 }
87 if (get_nulls_value(node) != slot)
88 goto begin;
89out:
90 sk = NULL;
91found:
92 return sk;
93}
94EXPORT_SYMBOL(__inet6_lookup_established);
95
96static inline int compute_score(struct sock *sk, struct net *net,
97 const unsigned short hnum,
98 const struct in6_addr *daddr,
99 const int dif, bool exact_dif)
100{
101 int score = -1;
102
103 if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
104 sk->sk_family == PF_INET6) {
105
106 score = 1;
107 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
108 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
109 return -1;
110 score++;
111 }
112 if (sk->sk_bound_dev_if || exact_dif) {
113 if (sk->sk_bound_dev_if != dif)
114 return -1;
115 score++;
116 }
117 if (sk->sk_incoming_cpu == raw_smp_processor_id())
118 score++;
119 }
120 return score;
121}
122
123
124struct sock *inet6_lookup_listener(struct net *net,
125 struct inet_hashinfo *hashinfo,
126 struct sk_buff *skb, int doff,
127 const struct in6_addr *saddr,
128 const __be16 sport, const struct in6_addr *daddr,
129 const unsigned short hnum, const int dif)
130{
131 unsigned int hash = inet_lhashfn(net, hnum);
132 struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
133 int score, hiscore = 0, matches = 0, reuseport = 0;
134 bool exact_dif = inet6_exact_dif_match(net, skb);
135 struct sock *sk, *result = NULL;
136 u32 phash = 0;
137
138 sk_for_each(sk, &ilb->head) {
139 score = compute_score(sk, net, hnum, daddr, dif, exact_dif);
140 if (score > hiscore) {
141 reuseport = sk->sk_reuseport;
142 if (reuseport) {
143 phash = inet6_ehashfn(net, daddr, hnum,
144 saddr, sport);
145 result = reuseport_select_sock(sk, phash,
146 skb, doff);
147 if (result)
148 return result;
149 matches = 1;
150 }
151 result = sk;
152 hiscore = score;
153 } else if (score == hiscore && reuseport) {
154 matches++;
155 if (reciprocal_scale(phash, matches) == 0)
156 result = sk;
157 phash = next_pseudo_random32(phash);
158 }
159 }
160 return result;
161}
162EXPORT_SYMBOL_GPL(inet6_lookup_listener);
163
164struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
165 struct sk_buff *skb, int doff,
166 const struct in6_addr *saddr, const __be16 sport,
167 const struct in6_addr *daddr, const __be16 dport,
168 const int dif)
169{
170 struct sock *sk;
171 bool refcounted;
172
173 sk = __inet6_lookup(net, hashinfo, skb, doff, saddr, sport, daddr,
174 ntohs(dport), dif, &refcounted);
175 if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
176 sk = NULL;
177 return sk;
178}
179EXPORT_SYMBOL_GPL(inet6_lookup);
180
181static int __inet6_check_established(struct inet_timewait_death_row *death_row,
182 struct sock *sk, const __u16 lport,
183 struct inet_timewait_sock **twp)
184{
185 struct inet_hashinfo *hinfo = death_row->hashinfo;
186 struct inet_sock *inet = inet_sk(sk);
187 const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
188 const struct in6_addr *saddr = &sk->sk_v6_daddr;
189 const int dif = sk->sk_bound_dev_if;
190 const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
191 struct net *net = sock_net(sk);
192 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
193 inet->inet_dport);
194 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
195 spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
196 struct sock *sk2;
197 const struct hlist_nulls_node *node;
198 struct inet_timewait_sock *tw = NULL;
199
200 spin_lock(lock);
201
202 sk_nulls_for_each(sk2, node, &head->chain) {
203 if (sk2->sk_hash != hash)
204 continue;
205
206 if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports, dif))) {
207 if (sk2->sk_state == TCP_TIME_WAIT) {
208 tw = inet_twsk(sk2);
209 if (twsk_unique(sk, sk2, twp))
210 break;
211 }
212 goto not_unique;
213 }
214 }
215
216
217
218
219 inet->inet_num = lport;
220 inet->inet_sport = htons(lport);
221 sk->sk_hash = hash;
222 WARN_ON(!sk_unhashed(sk));
223 __sk_nulls_add_node_rcu(sk, &head->chain);
224 if (tw) {
225 sk_nulls_del_node_init_rcu((struct sock *)tw);
226 __NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
227 }
228 spin_unlock(lock);
229 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
230
231 if (twp) {
232 *twp = tw;
233 } else if (tw) {
234
235 inet_twsk_deschedule_put(tw);
236 }
237 return 0;
238
239not_unique:
240 spin_unlock(lock);
241 return -EADDRNOTAVAIL;
242}
243
244static u32 inet6_sk_port_offset(const struct sock *sk)
245{
246 const struct inet_sock *inet = inet_sk(sk);
247
248 return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
249 sk->sk_v6_daddr.s6_addr32,
250 inet->inet_dport);
251}
252
253int inet6_hash_connect(struct inet_timewait_death_row *death_row,
254 struct sock *sk)
255{
256 u32 port_offset = 0;
257
258 if (!inet_sk(sk)->inet_num)
259 port_offset = inet6_sk_port_offset(sk);
260 return __inet_hash_connect(death_row, sk, port_offset,
261 __inet6_check_established);
262}
263EXPORT_SYMBOL_GPL(inet6_hash_connect);
264
265int inet6_hash(struct sock *sk)
266{
267 int err = 0;
268
269 if (sk->sk_state != TCP_CLOSE) {
270 local_bh_disable();
271 err = __inet_hash(sk, NULL);
272 local_bh_enable();
273 }
274
275 return err;
276}
277EXPORT_SYMBOL_GPL(inet6_hash);
278
