xref: /openbmc/linux/net/rds/bind.c (revision f9a82c48)
1 /*
2  * Copyright (c) 2006, 2018 Oracle and/or its affiliates. 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/ipv6.h>
37 #include <linux/if_arp.h>
38 #include <linux/jhash.h>
39 #include <linux/ratelimit.h>
40 #include "rds.h"
41 
42 static struct rhashtable bind_hash_table;
43 
44 static const struct rhashtable_params ht_parms = {
45 	.nelem_hint = 768,
46 	.key_len = RDS_BOUND_KEY_LEN,
47 	.key_offset = offsetof(struct rds_sock, rs_bound_key),
48 	.head_offset = offsetof(struct rds_sock, rs_bound_node),
49 	.max_size = 16384,
50 	.min_size = 1024,
51 };
52 
53 /* Create a key for the bind hash table manipulation.  Port is in network byte
54  * order.
55  */
56 static inline void __rds_create_bind_key(u8 *key, const struct in6_addr *addr,
57 					 __be16 port, __u32 scope_id)
58 {
59 	memcpy(key, addr, sizeof(*addr));
60 	key += sizeof(*addr);
61 	memcpy(key, &port, sizeof(port));
62 	key += sizeof(port);
63 	memcpy(key, &scope_id, sizeof(scope_id));
64 }
65 
66 /*
67  * Return the rds_sock bound at the given local address.
68  *
69  * The rx path can race with rds_release.  We notice if rds_release() has
70  * marked this socket and don't return a rs ref to the rx path.
71  */
72 struct rds_sock *rds_find_bound(const struct in6_addr *addr, __be16 port,
73 				__u32 scope_id)
74 {
75 	u8 key[RDS_BOUND_KEY_LEN];
76 	struct rds_sock *rs;
77 
78 	__rds_create_bind_key(key, addr, port, scope_id);
79 	rcu_read_lock();
80 	rs = rhashtable_lookup(&bind_hash_table, key, ht_parms);
81 	if (rs && (sock_flag(rds_rs_to_sk(rs), SOCK_DEAD) ||
82 		   !refcount_inc_not_zero(&rds_rs_to_sk(rs)->sk_refcnt)))
83 		rs = NULL;
84 
85 	rcu_read_unlock();
86 
87 	rdsdebug("returning rs %p for %pI6c:%u\n", rs, addr,
88 		 ntohs(port));
89 
90 	return rs;
91 }
92 
93 /* returns -ve errno or +ve port */
94 static int rds_add_bound(struct rds_sock *rs, const struct in6_addr *addr,
95 			 __be16 *port, __u32 scope_id)
96 {
97 	int ret = -EADDRINUSE;
98 	u16 rover, last;
99 	u8 key[RDS_BOUND_KEY_LEN];
100 
101 	if (*port != 0) {
102 		rover = be16_to_cpu(*port);
103 		if (rover == RDS_FLAG_PROBE_PORT)
104 			return -EINVAL;
105 		last = rover;
106 	} else {
107 		rover = max_t(u16, prandom_u32(), 2);
108 		last = rover - 1;
109 	}
110 
111 	do {
112 		if (rover == 0)
113 			rover++;
114 
115 		if (rover == RDS_FLAG_PROBE_PORT)
116 			continue;
117 		__rds_create_bind_key(key, addr, cpu_to_be16(rover),
118 				      scope_id);
119 		if (rhashtable_lookup_fast(&bind_hash_table, key, ht_parms))
120 			continue;
121 
122 		memcpy(rs->rs_bound_key, key, sizeof(rs->rs_bound_key));
123 		rs->rs_bound_addr = *addr;
124 		net_get_random_once(&rs->rs_hash_initval,
125 				    sizeof(rs->rs_hash_initval));
126 		rs->rs_bound_port = cpu_to_be16(rover);
127 		rs->rs_bound_node.next = NULL;
128 		rds_sock_addref(rs);
129 		if (!rhashtable_insert_fast(&bind_hash_table,
130 					    &rs->rs_bound_node, ht_parms)) {
131 			*port = rs->rs_bound_port;
132 			rs->rs_bound_scope_id = scope_id;
133 			ret = 0;
134 			rdsdebug("rs %p binding to %pI6c:%d\n",
135 				 rs, addr, (int)ntohs(*port));
136 			break;
137 		} else {
138 			rs->rs_bound_addr = in6addr_any;
139 			rds_sock_put(rs);
140 			ret = -ENOMEM;
141 			break;
142 		}
143 	} while (rover++ != last);
144 
145 	return ret;
146 }
147 
148 void rds_remove_bound(struct rds_sock *rs)
149 {
150 
151 	if (ipv6_addr_any(&rs->rs_bound_addr))
152 		return;
153 
154 	rdsdebug("rs %p unbinding from %pI6c:%d\n",
155 		 rs, &rs->rs_bound_addr,
156 		 ntohs(rs->rs_bound_port));
157 
158 	rhashtable_remove_fast(&bind_hash_table, &rs->rs_bound_node, ht_parms);
159 	rds_sock_put(rs);
160 	rs->rs_bound_addr = in6addr_any;
161 }
162 
163 int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
164 {
165 	struct sock *sk = sock->sk;
166 	struct rds_sock *rs = rds_sk_to_rs(sk);
167 	struct in6_addr v6addr, *binding_addr;
168 	struct rds_transport *trans;
169 	__u32 scope_id = 0;
170 	int ret = 0;
171 	__be16 port;
172 
173 	/* We allow an RDS socket to be bound to either IPv4 or IPv6
174 	 * address.
175 	 */
176 	if (uaddr->sa_family == AF_INET) {
177 		struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
178 
179 		if (addr_len < sizeof(struct sockaddr_in) ||
180 		    sin->sin_addr.s_addr == htonl(INADDR_ANY) ||
181 		    sin->sin_addr.s_addr == htonl(INADDR_BROADCAST) ||
182 		    IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
183 			return -EINVAL;
184 		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, &v6addr);
185 		binding_addr = &v6addr;
186 		port = sin->sin_port;
187 #if IS_ENABLED(CONFIG_IPV6)
188 	} else if (uaddr->sa_family == AF_INET6) {
189 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)uaddr;
190 		int addr_type;
191 
192 		if (addr_len < sizeof(struct sockaddr_in6))
193 			return -EINVAL;
194 		addr_type = ipv6_addr_type(&sin6->sin6_addr);
195 		if (!(addr_type & IPV6_ADDR_UNICAST)) {
196 			__be32 addr4;
197 
198 			if (!(addr_type & IPV6_ADDR_MAPPED))
199 				return -EINVAL;
200 
201 			/* It is a mapped address.  Need to do some sanity
202 			 * checks.
203 			 */
204 			addr4 = sin6->sin6_addr.s6_addr32[3];
205 			if (addr4 == htonl(INADDR_ANY) ||
206 			    addr4 == htonl(INADDR_BROADCAST) ||
207 			    IN_MULTICAST(ntohl(addr4)))
208 				return -EINVAL;
209 		}
210 		/* The scope ID must be specified for link local address. */
211 		if (addr_type & IPV6_ADDR_LINKLOCAL) {
212 			if (sin6->sin6_scope_id == 0)
213 				return -EINVAL;
214 			scope_id = sin6->sin6_scope_id;
215 		}
216 		binding_addr = &sin6->sin6_addr;
217 		port = sin6->sin6_port;
218 #endif
219 	} else {
220 		return -EINVAL;
221 	}
222 	lock_sock(sk);
223 
224 	/* RDS socket does not allow re-binding. */
225 	if (!ipv6_addr_any(&rs->rs_bound_addr)) {
226 		ret = -EINVAL;
227 		goto out;
228 	}
229 	/* Socket is connected.  The binding address should have the same
230 	 * scope ID as the connected address, except the case when one is
231 	 * non-link local address (scope_id is 0).
232 	 */
233 	if (!ipv6_addr_any(&rs->rs_conn_addr) && scope_id &&
234 	    rs->rs_bound_scope_id &&
235 	    scope_id != rs->rs_bound_scope_id) {
236 		ret = -EINVAL;
237 		goto out;
238 	}
239 
240 	sock_set_flag(sk, SOCK_RCU_FREE);
241 	ret = rds_add_bound(rs, binding_addr, &port, scope_id);
242 	if (ret)
243 		goto out;
244 
245 	if (rs->rs_transport) { /* previously bound */
246 		trans = rs->rs_transport;
247 		if (trans->laddr_check(sock_net(sock->sk),
248 				       binding_addr, scope_id) != 0) {
249 			ret = -ENOPROTOOPT;
250 			rds_remove_bound(rs);
251 		} else {
252 			ret = 0;
253 		}
254 		goto out;
255 	}
256 	trans = rds_trans_get_preferred(sock_net(sock->sk), binding_addr,
257 					scope_id);
258 	if (!trans) {
259 		ret = -EADDRNOTAVAIL;
260 		rds_remove_bound(rs);
261 		pr_info_ratelimited("RDS: %s could not find a transport for %pI6c, load rds_tcp or rds_rdma?\n",
262 				    __func__, binding_addr);
263 		goto out;
264 	}
265 
266 	rs->rs_transport = trans;
267 	ret = 0;
268 
269 out:
270 	release_sock(sk);
271 	return ret;
272 }
273 
274 void rds_bind_lock_destroy(void)
275 {
276 	rhashtable_destroy(&bind_hash_table);
277 }
278 
279 int rds_bind_lock_init(void)
280 {
281 	return rhashtable_init(&bind_hash_table, &ht_parms);
282 }
283