xref: /linux/net/rds/bind.c (revision 83bce9c2baa51e439480a713119a73d3c8b61083)
1 /*
2  * Copyright (c) 2006 Oracle.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  */
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 <linux/ratelimit.h>
39 #include "rds.h"
40 
41 static struct rhashtable bind_hash_table;
42 
43 static struct rhashtable_params ht_parms = {
44 	.nelem_hint = 768,
45 	.key_len = sizeof(u64),
46 	.key_offset = offsetof(struct rds_sock, rs_bound_key),
47 	.head_offset = offsetof(struct rds_sock, rs_bound_node),
48 	.max_size = 16384,
49 	.min_size = 1024,
50 };
51 
52 /*
53  * Return the rds_sock bound at the given local address.
54  *
55  * The rx path can race with rds_release.  We notice if rds_release() has
56  * marked this socket and don't return a rs ref to the rx path.
57  */
58 struct rds_sock *rds_find_bound(__be32 addr, __be16 port)
59 {
60 	u64 key = ((u64)addr << 32) | port;
61 	struct rds_sock *rs;
62 
63 	rs = rhashtable_lookup_fast(&bind_hash_table, &key, ht_parms);
64 	if (rs && !sock_flag(rds_rs_to_sk(rs), SOCK_DEAD))
65 		rds_sock_addref(rs);
66 	else
67 		rs = NULL;
68 
69 	rdsdebug("returning rs %p for %pI4:%u\n", rs, &addr,
70 		ntohs(port));
71 
72 	return rs;
73 }
74 
75 /* returns -ve errno or +ve port */
76 static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
77 {
78 	int ret = -EADDRINUSE;
79 	u16 rover, last;
80 	u64 key;
81 
82 	if (*port != 0) {
83 		rover = be16_to_cpu(*port);
84 		if (rover == RDS_FLAG_PROBE_PORT)
85 			return -EINVAL;
86 		last = rover;
87 	} else {
88 		rover = max_t(u16, prandom_u32(), 2);
89 		last = rover - 1;
90 	}
91 
92 	do {
93 		if (rover == 0)
94 			rover++;
95 
96 		if (rover == RDS_FLAG_PROBE_PORT)
97 			continue;
98 		key = ((u64)addr << 32) | cpu_to_be16(rover);
99 		if (rhashtable_lookup_fast(&bind_hash_table, &key, ht_parms))
100 			continue;
101 
102 		rs->rs_bound_key = key;
103 		rs->rs_bound_addr = addr;
104 		net_get_random_once(&rs->rs_hash_initval,
105 				    sizeof(rs->rs_hash_initval));
106 		rs->rs_bound_port = cpu_to_be16(rover);
107 		rs->rs_bound_node.next = NULL;
108 		rds_sock_addref(rs);
109 		if (!rhashtable_insert_fast(&bind_hash_table,
110 					    &rs->rs_bound_node, ht_parms)) {
111 			*port = rs->rs_bound_port;
112 			ret = 0;
113 			rdsdebug("rs %p binding to %pI4:%d\n",
114 			  rs, &addr, (int)ntohs(*port));
115 			break;
116 		} else {
117 			rds_sock_put(rs);
118 			ret = -ENOMEM;
119 			break;
120 		}
121 	} while (rover++ != last);
122 
123 	return ret;
124 }
125 
126 void rds_remove_bound(struct rds_sock *rs)
127 {
128 
129 	if (!rs->rs_bound_addr)
130 		return;
131 
132 	rdsdebug("rs %p unbinding from %pI4:%d\n",
133 		 rs, &rs->rs_bound_addr,
134 		 ntohs(rs->rs_bound_port));
135 
136 	rhashtable_remove_fast(&bind_hash_table, &rs->rs_bound_node, ht_parms);
137 	rds_sock_put(rs);
138 	rs->rs_bound_addr = 0;
139 }
140 
141 int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
142 {
143 	struct sock *sk = sock->sk;
144 	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
145 	struct rds_sock *rs = rds_sk_to_rs(sk);
146 	struct rds_transport *trans;
147 	int ret = 0;
148 
149 	lock_sock(sk);
150 
151 	if (addr_len != sizeof(struct sockaddr_in) ||
152 	    sin->sin_family != AF_INET ||
153 	    rs->rs_bound_addr ||
154 	    sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
155 		ret = -EINVAL;
156 		goto out;
157 	}
158 
159 	ret = rds_add_bound(rs, sin->sin_addr.s_addr, &sin->sin_port);
160 	if (ret)
161 		goto out;
162 
163 	if (rs->rs_transport) { /* previously bound */
164 		trans = rs->rs_transport;
165 		if (trans->laddr_check(sock_net(sock->sk),
166 				       sin->sin_addr.s_addr) != 0) {
167 			ret = -ENOPROTOOPT;
168 			rds_remove_bound(rs);
169 		} else {
170 			ret = 0;
171 		}
172 		goto out;
173 	}
174 	trans = rds_trans_get_preferred(sock_net(sock->sk),
175 					sin->sin_addr.s_addr);
176 	if (!trans) {
177 		ret = -EADDRNOTAVAIL;
178 		rds_remove_bound(rs);
179 		pr_info_ratelimited("RDS: %s could not find a transport for %pI4, load rds_tcp or rds_rdma?\n",
180 				    __func__, &sin->sin_addr.s_addr);
181 		goto out;
182 	}
183 
184 	rs->rs_transport = trans;
185 	ret = 0;
186 
187 out:
188 	release_sock(sk);
189 	return ret;
190 }
191 
192 void rds_bind_lock_destroy(void)
193 {
194 	rhashtable_destroy(&bind_hash_table);
195 }
196 
197 int rds_bind_lock_init(void)
198 {
199 	return rhashtable_init(&bind_hash_table, &ht_parms);
200 }
201