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