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