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33#include <linux/kernel.h>
34#include <net/sock.h>
35#include <linux/in.h>
36#include <linux/if_arp.h>
37#include <linux/jhash.h>
38#include "rds.h"
39
40#define BIND_HASH_SIZE 1024
41static struct hlist_head bind_hash_table[BIND_HASH_SIZE];
42static DEFINE_SPINLOCK(rds_bind_lock);
43
44static struct hlist_head *hash_to_bucket(__be32 addr, __be16 port)
45{
46 return bind_hash_table + (jhash_2words((u32)addr, (u32)port, 0) &
47 (BIND_HASH_SIZE - 1));
48}
49
50static struct rds_sock *rds_bind_lookup(__be32 addr, __be16 port,
51 struct rds_sock *insert)
52{
53 struct rds_sock *rs;
54 struct hlist_node *node;
55 struct hlist_head *head = hash_to_bucket(addr, port);
56 u64 cmp;
57 u64 needle = ((u64)be32_to_cpu(addr) << 32) | be16_to_cpu(port);
58
59 rcu_read_lock();
60 hlist_for_each_entry_rcu(rs, node, head, rs_bound_node) {
61 cmp = ((u64)be32_to_cpu(rs->rs_bound_addr) << 32) |
62 be16_to_cpu(rs->rs_bound_port);
63
64 if (cmp == needle) {
65 rcu_read_unlock();
66 return rs;
67 }
68 }
69 rcu_read_unlock();
70
71 if (insert) {
72
73
74
75
76
77
78 insert->rs_bound_addr = addr;
79 insert->rs_bound_port = port;
80 rds_sock_addref(insert);
81
82 hlist_add_head_rcu(&insert->rs_bound_node, head);
83 }
84 return NULL;
85}
86
87
88
89
90
91
92
93struct rds_sock *rds_find_bound(__be32 addr, __be16 port)
94{
95 struct rds_sock *rs;
96
97 rs = rds_bind_lookup(addr, port, NULL);
98
99 if (rs && !sock_flag(rds_rs_to_sk(rs), SOCK_DEAD))
100 rds_sock_addref(rs);
101 else
102 rs = NULL;
103
104 rdsdebug("returning rs %p for %pI4:%u\n", rs, &addr,
105 ntohs(port));
106 return rs;
107}
108
109
110static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
111{
112 unsigned long flags;
113 int ret = -EADDRINUSE;
114 u16 rover, last;
115
116 if (*port != 0) {
117 rover = be16_to_cpu(*port);
118 last = rover;
119 } else {
120 rover = max_t(u16, net_random(), 2);
121 last = rover - 1;
122 }
123
124 spin_lock_irqsave(&rds_bind_lock, flags);
125
126 do {
127 if (rover == 0)
128 rover++;
129 if (!rds_bind_lookup(addr, cpu_to_be16(rover), rs)) {
130 *port = rs->rs_bound_port;
131 ret = 0;
132 rdsdebug("rs %p binding to %pI4:%d\n",
133 rs, &addr, (int)ntohs(*port));
134 break;
135 }
136 } while (rover++ != last);
137
138 spin_unlock_irqrestore(&rds_bind_lock, flags);
139
140 return ret;
141}
142
143void rds_remove_bound(struct rds_sock *rs)
144{
145 unsigned long flags;
146
147 spin_lock_irqsave(&rds_bind_lock, flags);
148
149 if (rs->rs_bound_addr) {
150 rdsdebug("rs %p unbinding from %pI4:%d\n",
151 rs, &rs->rs_bound_addr,
152 ntohs(rs->rs_bound_port));
153
154 hlist_del_init_rcu(&rs->rs_bound_node);
155 rds_sock_put(rs);
156 rs->rs_bound_addr = 0;
157 }
158
159 spin_unlock_irqrestore(&rds_bind_lock, flags);
160}
161
162int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
163{
164 struct sock *sk = sock->sk;
165 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
166 struct rds_sock *rs = rds_sk_to_rs(sk);
167 struct rds_transport *trans;
168 int ret = 0;
169
170 lock_sock(sk);
171
172 if (addr_len != sizeof(struct sockaddr_in) ||
173 sin->sin_family != AF_INET ||
174 rs->rs_bound_addr ||
175 sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
176 ret = -EINVAL;
177 goto out;
178 }
179
180 ret = rds_add_bound(rs, sin->sin_addr.s_addr, &sin->sin_port);
181 if (ret)
182 goto out;
183
184 trans = rds_trans_get_preferred(sin->sin_addr.s_addr);
185 if (!trans) {
186 ret = -EADDRNOTAVAIL;
187 rds_remove_bound(rs);
188 if (printk_ratelimit())
189 printk(KERN_INFO "RDS: rds_bind() could not find a transport, "
190 "load rds_tcp or rds_rdma?\n");
191 goto out;
192 }
193
194 rs->rs_transport = trans;
195 ret = 0;
196
197out:
198 release_sock(sk);
199
200
201 if (ret)
202 synchronize_rcu();
203 return ret;
204}
205