1 /*
2 * Copyright (c) 2006, 2017 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 <linux/module.h>
35 #include <linux/in.h>
36 #include <linux/ipv6.h>
37
38 #include "rds.h"
39 #include "loop.h"
40
41 static char * const rds_trans_modules[] = {
42 [RDS_TRANS_IB] = "rds_rdma",
43 [RDS_TRANS_GAP] = NULL,
44 [RDS_TRANS_TCP] = "rds_tcp",
45 };
46
47 static struct rds_transport *transports[RDS_TRANS_COUNT];
48 static DECLARE_RWSEM(rds_trans_sem);
49
50 void rds_trans_register(struct rds_transport *trans)
51 {
52 BUG_ON(strlen(trans->t_name) + 1 > TRANSNAMSIZ);
53
54 down_write(&rds_trans_sem);
55
56 if (transports[trans->t_type])
57 printk(KERN_ERR "RDS Transport type %d already registered\n",
58 trans->t_type);
59 else {
60 transports[trans->t_type] = trans;
61 printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name);
62 }
63
64 up_write(&rds_trans_sem);
65 }
66 EXPORT_SYMBOL_GPL(rds_trans_register);
67
68 void rds_trans_unregister(struct rds_transport *trans)
69 {
70 down_write(&rds_trans_sem);
71
72 transports[trans->t_type] = NULL;
73 printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name);
74
75 up_write(&rds_trans_sem);
76 }
77 EXPORT_SYMBOL_GPL(rds_trans_unregister);
78
79 void rds_trans_put(struct rds_transport *trans)
80 {
81 if (trans)
82 module_put(trans->t_owner);
83 }
84
85 struct rds_transport *rds_trans_get_preferred(struct net *net,
86 const struct in6_addr *addr,
87 __u32 scope_id)
88 {
89 struct rds_transport *ret = NULL;
90 struct rds_transport *trans;
91 unsigned int i;
92
93 if (ipv6_addr_v4mapped(addr)) {
94 if (*(u_int8_t *)&addr->s6_addr32[3] == IN_LOOPBACKNET)
95 return &rds_loop_transport;
96 } else if (ipv6_addr_loopback(addr)) {
97 return &rds_loop_transport;
98 }
99
100 down_read(&rds_trans_sem);
101 for (i = 0; i < RDS_TRANS_COUNT; i++) {
102 trans = transports[i];
103
104 if (trans && (trans->laddr_check(net, addr, scope_id) == 0) &&
105 (!trans->t_owner || try_module_get(trans->t_owner))) {
106 ret = trans;
107 break;
108 }
109 }
110 up_read(&rds_trans_sem);
111
112 return ret;
113 }
114
115 struct rds_transport *rds_trans_get(int t_type)
116 {
117 struct rds_transport *ret = NULL;
118 struct rds_transport *trans;
119
120 down_read(&rds_trans_sem);
121 trans = transports[t_type];
122 if (!trans) {
123 up_read(&rds_trans_sem);
124 if (rds_trans_modules[t_type])
125 request_module(rds_trans_modules[t_type]);
126 down_read(&rds_trans_sem);
127 trans = transports[t_type];
128 }
129 if (trans && trans->t_type == t_type &&
130 (!trans->t_owner || try_module_get(trans->t_owner)))
131 ret = trans;
132
133 up_read(&rds_trans_sem);
134
135 return ret;
136 }
137
138 /*
139 * This returns the number of stats entries in the snapshot and only
140 * copies them using the iter if there is enough space for them. The
141 * caller passes in the global stats so that we can size and copy while
142 * holding the lock.
143 */
144 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
145 unsigned int avail)
146
147 {
148 struct rds_transport *trans;
149 unsigned int total = 0;
150 unsigned int part;
151 int i;
152
153 rds_info_iter_unmap(iter);
154 down_read(&rds_trans_sem);
155
156 for (i = 0; i < RDS_TRANS_COUNT; i++) {
157 trans = transports[i];
158 if (!trans || !trans->stats_info_copy)
159 continue;
160
161 part = trans->stats_info_copy(iter, avail);
162 avail -= min(avail, part);
163 total += part;
164 }
165
166 up_read(&rds_trans_sem);
167
168 return total;
169 }
170
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